WO2022085755A1 - Water-absorbable resin composition - Google Patents

Water-absorbable resin composition Download PDF

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Publication number
WO2022085755A1
WO2022085755A1 PCT/JP2021/038905 JP2021038905W WO2022085755A1 WO 2022085755 A1 WO2022085755 A1 WO 2022085755A1 JP 2021038905 W JP2021038905 W JP 2021038905W WO 2022085755 A1 WO2022085755 A1 WO 2022085755A1
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WIPO (PCT)
Prior art keywords
water
absorbent resin
mass
resin composition
parts
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PCT/JP2021/038905
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French (fr)
Japanese (ja)
Inventor
修輔 鎌田
晋広 笠野
健太朗 松井
真結 伊藤
信弘 小林
知哉 新居
大祐 松井
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株式会社日本触媒
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Priority to JP2022557600A priority Critical patent/JP7488910B2/en
Publication of WO2022085755A1 publication Critical patent/WO2022085755A1/en

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/53—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the absorbing medium
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L101/00—Compositions of unspecified macromolecular compounds
    • C08L101/02—Compositions of unspecified macromolecular compounds characterised by the presence of specified groups, e.g. terminal or pendant functional groups

Definitions

  • the present invention relates to a water-absorbent resin composition.
  • Water-absorbent resins are widely used in sanitary materials such as disposable diapers, menstrual napkins, and incontinence pads for the purpose of absorbing body fluids such as urine and blood, and are the main constituent materials of these sanitary materials. ing. In recent years, with the increasing demand for adult disposable diapers due to the aging of society, there is an increasing demand for imparting deodorant performance to water-absorbent resins, particularly excellent deodorant performance for malodor caused by urine.
  • Patent Documents 1, 2, and 3 Various methods have been proposed as an attempt to impart a deodorizing function to the water-absorbent resin.
  • a method of mixing a peroxo compound, a heavy metal (zeolite powder), or a porous polymer with an absorber is known (Patent Documents 1, 2, and 3, respectively).
  • Patent Document 4 a composition containing a water-absorbent resin and a hydrophobic porous polymer has been proposed (Patent Document 4).
  • the present invention aims at a novel water-absorbent resin composition having a deodorizing ability superior to that of the conventional one.
  • One form for achieving the above object comprises at least one component of a water-absorbent resin, a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle, and the span value represented by the following formula 1 is a span value. It is a water-absorbent resin composition of 1.10 or less.
  • D (90%) is a particle size (unit: ⁇ m) in which the cumulative particle size distribution from the minimum diameter is 90% in the cumulative particle size distribution.
  • D (10%) is a particle size (unit: ⁇ m) in which the cumulative particle size distribution from the minimum diameter is 10% in the cumulative particle size distribution.
  • D (50%) is a particle size (unit: ⁇ m) in which the cumulative particle size distribution from the minimum diameter is 50% in the cumulative particle size distribution, where D (90%) and D (10%).
  • D (50%) are cumulative values on a mass basis.
  • One aspect for achieving the above object includes a water-absorbent resin and at least one component of a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle, and the span value represented by the following formula 1 is , 1.10 or less, is a water-absorbent resin composition.
  • D (90%) is a particle size (unit: ⁇ m) in which the cumulative particle size distribution from the minimum diameter is 90% in the cumulative particle size distribution.
  • D (10%) is a particle size (unit: ⁇ m) in which the cumulative particle size distribution from the minimum diameter is 10% in the cumulative particle size distribution.
  • D (50%) is a particle size (unit: ⁇ m) in which the cumulative particle size distribution from the minimum diameter is 50% in the cumulative particle size distribution, where D (90%) and D (10%).
  • D (50%) are cumulative values on a mass basis.
  • Water-absorbent resin, base polymer, water-absorbent resin composition The "water-absorbent resin” in the present invention means a water-swellable water-insoluble polymer gelling agent and is generally used. It is in the form of powder. Further, “water swellability” means that the absorption ratio under no pressure (CRC) defined in EDANA WSP241.3 (10) described later is 5 g / g or more, and “water insoluble” means WSP270. It means that the soluble content (Ext) defined in 3 (10) is 50% by mass or less, respectively.
  • the "water-absorbent resin” is preferably a hydrophilic crosslinked polymer (so-called internal crosslinked polymer) formed by cross-linking and polymerizing an unsaturated monomer having a carboxyl group, but the total amount (100% by mass) thereof is It does not have to be a crosslinked polymer.
  • a “water-absorbent resin” is a "polymer in which only the inside is crosslinked (that is, a polymer in which the crosslink density between the inside and the surface is substantially the same)” or "a polymer in which the inside and the surface are crosslinked. In some cases, it refers to a polymer that has been cross-linked (that is, a polymer whose surface cross-linking density is relatively high relative to the internal cross-linking density).
  • base polymer and the polymer in which the inside and the surface are crosslinked is referred to as "water-absorbent resin”.
  • the "water-absorbent resin composition” in the present invention contains at least one component of a water-absorbent resin, a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle, and if necessary, other components. It means a composition containing, but in a nutshell, it means a water-absorbent resin that is ready to be shipped as a final product. Therefore, if the "water-absorbent resin” contains at least one component of a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle, and if necessary, other additives, the "water-absorbent resin composition” is obtained. .. In the present specification, the water-absorbent resin composition may be simply referred to as a water-absorbent agent.
  • EDANA and "WSP”
  • EDANA is an abbreviation for European Disposables and Nonwovens Associations.
  • WSP is an abbreviation for Worldwise Strategic Partners, and indicates a world standard measurement method for water-absorbent resin provided by EDANA. In the present invention, unless otherwise specified, the physical properties of the water-absorbent resin are measured in accordance with the original WSP (revised in 2010 / publicly known literature).
  • CRC which means the absorption ratio under no pressure
  • CRC is an abbreviation for Centrifuge Retention Capacity, and means the absorption ratio of a water-absorbing agent or a water-absorbent resin under no pressure.
  • 0.2 g of a water-absorbing agent or a water-absorbent resin is placed in a bag made of a non-woven fabric, and then immersed in a large excess of 0.9% by mass sodium chloride aqueous solution for 30 minutes to freely swell the water-absorbent resin. Then, it is the absorption ratio (unit: g / g) after dehydration for 3 minutes using a centrifuge (250 G).
  • AAP is an abbreviation for Absorption against Pressure, and means the absorption ratio under pressure of a water-absorbing agent or a water-absorbent resin. Specifically, absorption after swelling 0.9 g of a water-absorbing agent or a water-absorbent resin with a large excess of 0.9 mass% sodium chloride aqueous solution for 1 hour under a load of 4.83 kPa (0.7 psi). Magnification (unit: g / g).
  • the water-absorbent resin composition according to the embodiment of the present invention contains at least one of a water-absorbent resin, a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle. And, the span value represented by the formula 1 is 1.10 or less.
  • water-absorbent resins examples include polyacrylic acid (salt) -based water-absorbent resin, polysulfonic acid (salt) -based water-absorbent resin, maleic anhydride (salt) -based water-absorbent resin, polyacrylamide-based water-absorbent resin, and polyvinyl alcohol-based resin.
  • Water-absorbent resin polyethylene oxide-based water-absorbent resin, polyaspartic acid (salt) -based water-absorbent resin, polyglutamic acid (salt) -based water-absorbent resin, polyarginic acid (salt) -based water-absorbent resin, starch-based water-absorbent resin, cellulose-based Examples include water-absorbent resins. Of these, it is preferably used as a polyacrylic acid (salt) -based water-absorbent resin.
  • the "polyacrylic acid (salt) -based water-absorbent resin” in the embodiment of the present invention is a water-absorbent resin made from acrylic acid and / or a salt thereof (hereinafter referred to as "acrylic acid (salt)").
  • acrylic acid (salt) means. That is, the polyacrylic acid (salt) -based water-absorbent resin is a water-absorbent resin having a structural unit derived from acrylic acid (salt) in the polymer and having a graft component as an optional component.
  • the polyacrylic acid (salt) -based water-absorbent resin is preferably 50 mol% to 100 mol%, more, with respect to the entire monomer involved in the polymerization reaction (however, excluding the internal cross-linking agent).
  • a water-absorbent resin preferably containing 70 mol% to 100 mol%, more preferably 90 mol% to 100 mol%, and particularly preferably substantially 100 mol% of acrylic acid (salt).
  • This step is a step of preparing a monomer aqueous solution containing a monomer containing acrylic acid (salt) as a main component and at least one kind of internal cross-linking agent.
  • the "main component” means that the amount (content) of acrylic acid (salt) used is usually 50 mol% with respect to the entire monomer (however, excluding the internal cross-linking agent) subjected to the polymerization reaction. As mentioned above, it means that it is preferably 70 mol% or more, more preferably 90 mol% or more (upper limit is 100 mol%).
  • a monomer slurry solution can be used as long as it does not affect the water absorption performance of the water absorbing agent obtained as a final product, the monomer aqueous solution will be described here for convenience.
  • acrylic acid (salt) In the embodiment of the present invention, it is preferable to use a known acrylic acid (salt) as a monomer (also referred to as a polymerizable monomer) from the viewpoint of physical properties and productivity of the water absorbent.
  • Known acrylic acids contain trace amounts of components such as polymerization inhibitors and impurities.
  • the polymerization inhibitor methoxyphenols are preferably used, and p-methoxyphenols are more preferably used.
  • the content (concentration) of the polymerization inhibitor in acrylic acid is preferably 200 ppm (mass standard) or less, more preferably 10 ppm (mass standard) to 160 ppm, from the viewpoint of the polymerizable property of acrylic acid and the color tone of the water absorbent.
  • examples of the acrylate include a salt obtained by neutralizing the above-mentioned acrylic acid with the following basic compound.
  • the acrylate may be a commercially available acrylate (for example, sodium acrylate) or a salt obtained by neutralizing acrylic acid.
  • the basic compound in the embodiment of the present invention refers to a compound exhibiting basicity, and specifically, sodium hydroxide or the like is applicable.
  • Commercially available sodium hydroxide contains heavy metals such as zinc, lead, and iron on the order of ppm (mass basis), and can be expressed as a composition in a strict sense. Compositions are also treated as being included in the category of basic compounds.
  • the basic compound examples include alkali metal carbonates and bicarbonates, alkali metal hydroxides, ammonia, organic amines and the like.
  • a strongly basic compound is selected from the viewpoint of the water absorption performance of the water absorbing agent. Therefore, hydroxides of alkali metals such as sodium, potassium and lithium are preferable, and sodium hydroxide is more preferable.
  • the basic compound is preferably an aqueous solution from the viewpoint of handleability.
  • the timing of the neutralization is not particularly limited, and may be any of pre-polymerization, during-polymerization, and post-polymerization. Neutralization can also be performed at the time or place of. Further, from the viewpoint of the production efficiency of the water absorbing agent, it is preferable to neutralize in a continuous manner.
  • the neutralization rate thereof is preferably 10 mol% to 90 mol%, more preferably 40 mol% to 85 mol%, and further, with respect to the acid group of the monomer. It is preferably 50 mol% to 80 mol%, and particularly preferably 60 mol% to 78 mol%. By setting the neutralization rate within the range, it is possible to suppress the deterioration of the water absorption performance of the water absorbing agent.
  • the range of the neutralization rate is applied to any of the above-mentioned neutralization before, during, and after the polymerization. The same applies to the water absorbing agent as a final product.
  • a monomer other than the above-mentioned acrylic acid (salt) (hereinafter, referred to as “other monomer”) can be used in combination with acrylic acid (salt), if necessary.
  • the other monomers include (anhydrous) maleic acid, itaconic acid, acrylate, vinyl sulfonic acid, allyltoluenesulfonic acid, vinyltoluenesulfonic acid, styrenesulfonic acid, and 2- (meth).
  • Anionic unsaturated monomers such as acrylamide-2-methylpropanesulfonic acid, 2- (meth) acryloylethanesulfonic acid, 2- (meth) acryloylpropanesulfonic acid, 2-hydroxyethyl (meth) acryloyl phosphate and the like.
  • mercaptan group-containing unsaturated monomer phenolic hydroxyl group-containing unsaturated monomer; amide group-containing unsaturated such as (meth) acrylamide, N-ethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, etc.
  • Monomer; Amino group-containing unsaturated monomer such as N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylamide Can be mentioned.
  • the other monomer includes a water-soluble or hydrophobic unsaturated monomer.
  • the amount used is preferably 30 mol% or less, more preferably 10 mol% or less, still more preferably 10 mol% or less, based on the entire monomer (excluding the internal cross-linking agent). Is 5 mol% or less.
  • an internal cross-linking agent In a preferred manufacturing method, an internal cross-linking agent is used.
  • the internal cross-linking agent include N, N'-methylenebis (meth) acrylamide, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, and trimethylolpropane.
  • At least one kind of internal cross-linking agent is selected in consideration of reactivity and the like. Further, from the viewpoint of the water absorption performance of the water absorbing agent, an internal cross-linking agent having two or more polymerizable unsaturated groups is preferable, an internal cross-linking agent having thermal decomposability at a drying temperature is more preferable, and (poly) alkylene is more preferable. An internal cross-linking agent having two or more polymerizable unsaturated groups having a glycol structure is selected.
  • polymerizable unsaturated group examples include an allyl group and a (meth) acrylate group, more preferably a (meth) acrylate group.
  • poly (poly) alkylene glycol structure examples include polyethylene glycol.
  • the number of alkylene glycol units (hereinafter, may be referred to as n) is preferably 1 to 100, more preferably 6 to 50, still more preferably 6 to 20, and most preferably 6. ⁇ 10.
  • the amount of the internal cross-linking agent used is preferably 0.0001 mol% to 10 mol%, more preferably 0.001 mol% to 5 mol%, based on the entire monomer (excluding the internal cross-linking agent). , More preferably 0.01 mol% to 1 mol%.
  • the amount to be used within the above range, a water-absorbing agent having a desired water-absorbing performance can be obtained.
  • the adjustment of the amount of the internal cross-linking agent should be considered. It is also preferable.
  • the internal cross-linking agent is preferably added in advance at the time of preparation of the monomer aqueous solution, and in this case, the cross-linking reaction is carried out at the same time as the polymerization reaction.
  • these methods can also be used together.
  • the substance include hydrophilic polymers such as starch, starch derivatives, cellulose, cellulose derivatives, polyvinyl alcohol (PVA), polyacrylic acid (salt), and crosslinked polyacrylic acid (salt); carbonic acid.
  • hydrophilic polymers such as starch, starch derivatives, cellulose, cellulose derivatives, polyvinyl alcohol (PVA), polyacrylic acid (salt), and crosslinked polyacrylic acid (salt); carbonic acid.
  • PVA polyvinyl alcohol
  • polyacrylic acid salt
  • carbonic acid crosslinked polyacrylic acid
  • carbonic acid examples thereof include salts, azo compounds, compounds such as foaming agents that generate various bubbles, surfactants, chelating agents, and chain transfer agents.
  • the amount of the hydrophilic polymer added is preferably 50% by mass or less, more preferably 20% by mass or less, still more preferably 10% by mass or less, and particularly preferably 5% by mass or less, based on the aqueous monomer solution. There is (the lower limit is
  • a graft polymer or a water-absorbent resin composition for example, a starch-acrylic acid (salt) copolymer, a PVA-acrylic acid (salt) copolymer
  • Etc. is obtained.
  • a monomer aqueous solution is prepared by selecting various substances (components) described above according to the purpose, and if necessary, specifying the respective amounts so as to satisfy the above range and mixing them with each other.
  • the monomer in addition to using the monomer as an aqueous solution, it can also be used as a mixed solution of water and a hydrophilic solvent.
  • the total concentration of each substance (component) is preferably 10% by mass to 80% by mass, more preferably 20% by mass from the viewpoint of the physical properties of the water absorbing agent. It is ⁇ 75% by mass, more preferably 30% by mass to 70% by mass.
  • the concentration of the monomer component is calculated from the following formula (2).
  • the mass of the graft component, the water-absorbent resin, and the hydrophobic organic solvent in the reverse phase suspension polymerization is not included in the (mass of the monomer aqueous solution).
  • a polymerization initiator is used during polymerization.
  • the polymerization initiator include a thermal decomposition type polymerization initiator, a photodegradable polymerization initiator, and a redox-based polymerization initiator in which a reducing agent that promotes the decomposition of these polymerization initiators is used in combination.
  • Specific examples of the polymerization initiator include sodium persulfate, potassium persulfate, ammonium persulfate, t-butyl hydroperoxide, hydrogen peroxide, and 2,2'-azobis (2-amidinopropane) dihydrochloride. Examples include radical polymerization initiators.
  • At least one type of polymerization initiator is selected in consideration of the polymerization form and the like. Further, from the viewpoint of the handleability of the polymerization initiator and the physical properties of the water-absorbing agent, a peroxide or an azo compound, more preferably a peroxide, and further preferably a persulfate are selected as the polymerization initiator.
  • a peroxide or an azo compound more preferably a peroxide, and further preferably a persulfate are selected as the polymerization initiator.
  • a reducing agent such as sodium sulfite, sodium hydrogen sulfite, ferrous sulfate, or L-ascorbic acid may be used in combination to carry out redox polymerization.
  • the amount of the polymerization initiator used is preferably 0.001 mol% to 1 mol%, more preferably 0.001 mol% to 0.5, based on the entire monomer (excluding the internal cross-linking agent). It is mol%, more preferably 0.01 mol% to 0.1 mol%.
  • the amount of the reducing agent used is preferably 0.0001 mol% to 0.02 mol%, more preferably 0.0005 mol% or more, based on the entire monomer (excluding the internal cross-linking agent). It is 0.015 mol%.
  • the polymerization reaction may be started by irradiation with thermal energy or active energy rays such as radiation, electron beam, and ultraviolet rays. Further, irradiation with active energy rays and the polymerization initiator may be used in combination.
  • polymerization form examples of the polymerization form applied to the present invention include aqueous solution polymerization, reverse phase suspension polymerization, spray polymerization, droplet polymerization, bulk polymerization, precipitation polymerization and the like. Among them, from the viewpoint of ease of polymerization control and water absorption performance of the water-absorbing agent, aqueous solution polymerization or reverse phase suspension polymerization is more preferable, aqueous solution polymerization is more preferable, and continuous aqueous solution polymerization is more preferable. Reversed phase suspension polymerization is described in International Publication No. 2007/004529, International Publication No. 2012/023433 and the like.
  • the continuous aqueous solution polymerization can produce a water absorbing agent with high productivity, and specific examples thereof include US Pat. No. 4,893999, US Pat. No. 6,906,159, US Pat. No. 7,091253, and US Pat. No. 7,741400. Examples thereof include continuous belt polymerization described in US Pat. No. 8519212, JP-A-2005-36100, and continuous kneader polymerization described in US Pat. No. 6,987,151.
  • Preferred forms of the continuous aqueous solution polymerization include high temperature start polymerization, high concentration polymerization, foam polymerization and the like.
  • the temperature of the aqueous monomer solution at the start of polymerization is preferably 30 ° C. or higher, more preferably 35 ° C. or higher, further preferably 40 ° C. or higher, and particularly preferably 50 ° C. or higher (upper limit is a single amount).
  • the monomer concentration at the start of polymerization is preferably 30% by mass or more, more preferably 35% by mass or more, still more preferably 40% by mass or more, and particularly preferably 45% by mass or more (upper limit is 45% by mass).
  • each of the above-mentioned polymerization forms can be carried out in an air atmosphere, but from the viewpoint of the color tone of the water absorbing agent, it should be carried out in an inert gas atmosphere such as nitrogen or argon (oxygen concentration is 1 volume% or less). Is preferable. It is also preferable that the dissolved oxygen in the monomer aqueous solution is sufficiently substituted with an inert gas (the amount of dissolved oxygen is less than 1 mg / L).
  • a water-containing gel with a foamed shape also known as porous
  • a water-absorbing resin, or a water-absorbing agent by foam polymerization
  • the water-absorbing rate of the water-absorbing agent can be improved, and the water-absorbing agent can be easily immobilized on the absorbing article.
  • the foamed shape can be confirmed by the holes on the surface of the particles (for example, holes having a diameter of 1 to 100 ⁇ m) with an electron microscope.
  • the number of pores is preferably one or more, more preferably 1 to 10000, and 10 to 1000 per water absorbing agent, and can be controlled by the foam polymerization.
  • the foam polymerization is a preferable technique for increasing the BET specific surface area of the water-absorbent resin and the water-absorbent agent described later.
  • Gel crushing step This step is a step of gel crushing the hydrous gel obtained in the polymerization step to obtain a particulate hydrogel (hereinafter, also referred to as “particulate hydrogel”). ..
  • this step is referred to as "gel crushing”.
  • the gel crushing refers to adjusting the water-containing gel to a predetermined size using a gel crusher such as a kneader, a meat chopper, or a cutter mill.
  • the contents described in International Publication No. 2011/126079 pamphlet are preferably applied to the present invention.
  • the polymerization step and the gel crushing step are carried out at the same time.
  • a particulate hydrogel such as reverse phase suspension polymerization, spray polymerization or droplet polymerization is obtained in the polymerization step, it is considered that the gel pulverization step is carried out at the same time as the polymerization step.
  • an amorphous crushed water-absorbent resin or a water-absorbent agent can be obtained.
  • the gel granulated by the gel crushing step is generally preferably in the range of 0.1 to 10 mm. If the gel is finer than 0.1 mm, the physical properties of the obtained water-absorbent resin may be low. If it is larger than 10 mm, it may be difficult to dry.
  • the mass average particle diameter (D50) of the particulate hydrogel is preferably 500 ⁇ m to 2000 ⁇ m, more preferably 550 ⁇ m to 1500 ⁇ m, and further preferably 600 ⁇ m to 1000 ⁇ m.
  • the gel crushing method described in International Publication No. 2011/126079 pamphlet it is preferable to use the gel crushing method described in International Publication No. 2011/126079 pamphlet. Further, the gel pulverization technique may be combined with the above-mentioned foam polymerization.
  • the method for measuring the mass average particle diameter (D50) of the particulate hydrogel is the method described in International Publication No. 2011/126079.
  • This step is a step of drying the hydrous gel and / or the particulate hydrogel obtained in the polymerization step and / or the gel pulverization step to a desired resin solid content to obtain a dry polymer.
  • the resin solid content is determined by drying weight loss (mass change when 1 g of water-absorbent resin is heated at 180 ° C. for 3 hours), and is preferably 80% by mass or more, more preferably 85% by mass to 99% by mass, and further preferably. Is 90% by mass to 98% by mass, particularly preferably 92% by mass to 97% by mass.
  • the drying method of the hydrous gel and / or the particulate hydrogel is, for example, heat drying, hot air drying, vacuum drying, fluidized layer drying, infrared drying, microwave drying, drum dryer drying, co-boiling dehydration with a hydrophobic organic solvent. Drying by, high humidity drying using high temperature steam, etc. can be mentioned. Above all, from the viewpoint of drying efficiency, hot air drying is preferable, and band drying in which hot air drying is performed on a ventilation belt is more preferable.
  • the drying temperature (hot air temperature) in the hot air drying is preferably 120 ° C. to 250 ° C., more preferably 140 ° C. to 200 ° C. from the viewpoint of the color tone of the water-absorbent resin and the drying efficiency. Drying conditions other than the drying temperature, such as the wind speed and drying time of hot air, may be appropriately set according to the water content and total mass of the particulate hydrogel to be dried and the target resin solid content.
  • the conditions described in the international publication 2006/100300 pamphlet, 2011/025012 pamphlet, 2011/025013 pamphlet, 2011/11657 pamphlet, etc. are appropriately applied. Will be done.
  • the drying time is preferably 10 minutes to 2 hours, more preferably 20 minutes to 150 minutes, and even more preferably 30 minutes to 100 minutes.
  • the dry polymer obtained through the drying step is ground (grinding step) and adjusted to a desired particle size (classifying step) to obtain a base polymer (classification step).
  • This is a step of obtaining a water-absorbent resin) before surface cross-linking.
  • an amorphous crushed water-absorbent resin or a water-absorbing agent can be obtained. Grinding may be performed twice or more if necessary.
  • a base polymer water-absorbent resin before surface cross-linking
  • a water-absorbent resin composition satisfying the desired span value. You can get things.
  • Examples of the crusher used in the crushing step include high-speed rotary crushers such as roll mills, hammer mills, screw mills, and pin mills, vibration mills, knuckle type crushers, and cylindrical mixers. Of these, a roll mill is preferably selected from the viewpoint of pulverization efficiency. Further, a plurality of these crushers can be used in combination.
  • Examples of the method for adjusting the particle size in the classification step include sieve classification using a JIS standard sieve (JIS Z8801-1 (2000)), air flow classification, and the like. Above all, sieving classification is preferably selected from the viewpoint of classification efficiency.
  • the adjustment of the particle size of the water absorbent is not limited to the pulverization step and the classification step, but is not limited to the polymerization step (particularly reverse phase suspension polymerization, droplet polymerization, etc.) and other steps (for example, granulation step). It can also be carried out in the fine powder recovery process).
  • the mass average particle size (D50) of the base polymer is 300 to 600 ⁇ m. Further, in one embodiment of the present invention, the proportion of particles smaller than 150 ⁇ m in the base polymer is 5% by mass or less. The lower limit of the proportion of particles smaller than 150 ⁇ m is 0% by mass.
  • the mass average particle size (D50) of the base polymer is preferably 300 to 500 ⁇ m, more preferably 300 to 450 ⁇ m.
  • the proportion of particles of less than 150 ⁇ m in the base polymer is more preferably 4% by mass or less, further preferably 3% by mass or less, and particularly preferably 2% by mass or less.
  • the span value is 1.10 or less. If it exceeds 1.10, the desired effect of the present invention cannot be achieved. According to the embodiment of the present invention, it is preferably adjusted to be 0.40 or more, more preferably 0.40 to 1.10, and even more preferably 0.45 to 1.05. It is adjusted so as to be 0.50 to 1.00, and more preferably 0.50 to 1.00.
  • the span value described above in one embodiment of the present invention can be applied not only to the water-absorbent resin after surface cross-linking but also to the water-absorbing agent (particulate water-absorbing agent) as a final product. Therefore, it is preferable to carry out a surface cross-linking treatment (surface cross-linking step) so as to maintain the span value adjusted by the base polymer, and an appropriate granulation step is provided after the surface cross-linking step to adjust the span value to a specific span value. Is more preferable.
  • the mass average particle size (D50) of the base polymer can be applied not only to the water-absorbent resin after surface cross-linking but also to the water-absorbing agent (particulate water-absorbing agent) as a final product. Therefore, it is preferable to maintain the mass average particle size (D50) adjusted with the base polymer. Therefore, the mass average particle size (D50) of the water-absorbent resin composition is also preferably 300 to 600 ⁇ m, more preferably 300 to 500 ⁇ m, and even more preferably 300 to 450 ⁇ m.
  • This step is a step of providing a portion having a higher cross-linking density on the surface layer of the base polymer obtained through each of the above steps, and is a mixing step, a heat treatment step, and cooling as necessary.
  • the structure includes processes and the like.
  • radical cross-linking, surface polymerization, a cross-linking reaction with a surface cross-linking agent and the like occur on the surface of the base polymer, and a surface-crosslinked water-absorbent resin can be obtained.
  • a solution containing a surface cross-linking agent (hereinafter referred to as “surface cross-linking agent solution”) is mixed with a base polymer in a mixing device to obtain a humidified mixture. Is.
  • a surface cross-linking agent is used during surface cross-linking.
  • Specific examples of the surface cross-linking agent include the surface cross-linking agent described in US Pat. No. 7,183,456. From these surface cross-linking agents, at least one kind of surface cross-linking agent is selected in consideration of reactivity and the like. Further, from the viewpoint of the handleability of the surface cross-linking agent and the water-absorbing performance of the water-absorbing agent, a surface cross-linking agent having two or more functional groups that react with a carboxyl group, and an organic compound forming a covalent bond is preferably selected. Will be done.
  • the surface cross-linking agent includes ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, and 1,2-butane.
  • Preferred surface cross-linking agents include polyhydric alcohol compounds such as propylene glycol and 1,3-propanediol, alkylene carbonate compounds such as ethylene carbonate, polyhydric glycidyl compounds such as ethylene glycol diglycidyl ether, and polyhydric amines such as diethylenetriamine. be.
  • the amount of the surface cross-linking agent used is preferably 0.01 part by mass to 10 parts by mass, and more preferably 0.01 part by mass with respect to 100 parts by mass of the base polymer. It is ⁇ 5 parts by mass, more preferably 0.01 part by mass to 2 parts by mass, further preferably 0.1 part by mass to 1.8 part by mass, and even more preferably 0.5 part by mass to 1. 5 parts by mass.
  • the amount of the surface cross-linking agent is preferably 0.01 part by mass to 10 parts by mass, and more preferably 0.01 part by mass with respect to 100 parts by mass of the base polymer. It is ⁇ 5 parts by mass, more preferably 0.01 part by mass to 2 parts by mass, further preferably 0.1 part by mass to 1.8 part by mass, and even more preferably 0.5 part by mass to 1. 5 parts by mass.
  • the surface cross-linking agent is preferably added to the base polymer in the form of an aqueous solution.
  • the amount of water used is preferably 0.1 part by mass to 20 parts by mass, more preferably 0.3 part by mass to 15 parts by mass, and further preferably 0.5 part by mass with respect to 100 parts by mass of the base polymer. It is 10 parts by mass.
  • a hydrophilic organic solvent can be used in combination with the water as needed to prepare the surface cross-linking agent solution.
  • the amount of the hydrophilic organic solvent used is preferably small so as not to cause an unpleasant odor, preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and further, with respect to 100 parts by mass of the base polymer. It is preferably 2 parts by mass or less, and even more preferably 1 part by mass or less.
  • it is preferable to add a hydrophilic organic solvent and the amount to be added is preferably 0.1 part by mass or more, and 0.5 part by mass or more with respect to 100 parts by mass of the base polymer. Is more preferable.
  • hydrophilic organic solvent examples include lower (for example, 1 to 3 carbon atoms) alcohols such as methyl alcohol and isopropyl alcohol; ketones such as acetone; ethers such as dioxane; N, N-dimethyl. Amides such as formamide; sulfoxides such as dimethyl sulfoxide and the like can be mentioned.
  • a surface cross-linking agent solution is prepared in advance, and the solution is preferably sprayed or dropped onto the base polymer, and more preferably sprayed and mixed. The method is selected.
  • Heat Treatment Step This step is a step of applying heat to the humidified mixture obtained in the mixing step to cause a crosslinking reaction on the surface of the base polymer.
  • the humidified mixture may be heated in a stationary state or may be heated in a fluid state by using a power such as stirring, but the humidified mixture can be heated evenly in that the whole humidified mixture can be heated evenly. It is preferable to heat underneath.
  • the heat treatment apparatus that performs the heat treatment includes a paddle dryer, a multi-fin processor, a tower dryer and the like.
  • the heating temperature in this step is preferably 150 ° C. to 250 ° C., more preferably 170 ° C. to 250 ° C., still more preferably 180 ° C. to 230, from the viewpoint of the type and amount of the surface cross-linking agent and the water absorption performance of the water absorbing agent. °C.
  • the heating time is at least 5 minutes, preferably at least 7 minutes.
  • the upper limit is preferably 150 minutes or less, more preferably 120 minutes or less, and even more preferably 100 minutes or less.
  • Cooling step This step is an arbitrary step provided as necessary after the heat treatment step. This step is a step of forcibly cooling the high-temperature water-absorbent resin that has completed the heat treatment step to a predetermined temperature to promptly terminate the surface cross-linking reaction.
  • the water-absorbent resin composition comprises at least one component of a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle.
  • the water-absorbent resin composition contains at least one component of the hydrophobic porous polymer adsorbent and the resin having a nitrogen-containing heterocycle.
  • this (water-insoluble) hydrophobic porous polymer adsorbent is effective in adsorbing a hydrophobic compound having a medium molecular size and exhibiting a deodorizing effect. More specifically, the hydrophobic porous polymer adsorbent efficiently adsorbs hydrophobic compounds of medium molecular size (eg, phenol, cresol, phenylacetic acid) and the like, and has the effect of reducing urine odor. It is thought that. However, as will be described later, a mechanism that does not have a better deodorizing ability is unknown unless a hydrophobic porous polymer adsorbent is used and the span value is adjusted to a specific value or less.
  • medium molecular size eg, phenol, cresol, phenylacetic acid
  • the water-absorbent resin composition contains a resin having a nitrogen-containing heterocycle.
  • the nitrogen-containing heterocycle is typically basic like ammonia and the like, it is considered that it does not have high adsorption performance for basic substances derived from urine.
  • the resin having such a basic nitrogen-containing heterocycle had a better deodorizing ability.
  • the mechanism that produces such a result is unknown, in other words, it can be said that the invention has an inventive step that is unpredictable to those skilled in the art.
  • the water-absorbent resin composition comprises both a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle.
  • the addition amount of at least one component of the hydrophobic porous polymer adsorbent and the resin having a nitrogen-containing heterocycle (when used in combination, the total addition amount; the form of water dispersion).
  • the amount added in terms of solid content is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 8 parts by mass with respect to 100 parts by mass of the water-absorbent resin, from the viewpoint of the effect of suppressing urine odor. It is by mass, more preferably 0.15 to 5 parts by mass, and particularly preferably 0.2 to 3 parts by mass.
  • Such a preferable addition amount is the same as the preferable content in the water-absorbent resin composition unless a treatment for opening the nitrogen-containing heterocycle (for example, heating at a high temperature) is performed. That is, according to one embodiment of the present invention, the content of at least one component of the hydrophobic porous polymer adsorbent and the resin having a nitrogen-containing heterocycle in the water-absorbent resin composition (when used in combination).
  • the total content is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the water-absorbent resin. It is 8 parts by mass, more preferably 0.15 to 5 parts by mass, and particularly preferably 0.2 to 3 parts by mass.
  • the hydrophobic porous polymer adsorbent is a non-naturally occurring hydrophobic porous polymer adsorbent (ie, a synthetic adsorbent).
  • the base polymer may be surface-crosslinked after adding a hydrophobic porous polymer adsorbent to the base polymer before surface cross-linking, but in order to enhance the deodorizing effect of the hydrophobic porous polymer adsorbent, It is preferable to add a hydrophobic porous polymer adsorbent to the surface-crosslinked water-absorbent resin. In that sense, the hydrophobic porous polymer adsorbent should not be added in the surface cross-linking step.
  • the hydrophobic porous polymer adsorbent is a polymer that is hydrophobic and has an average pore diameter of 20 to 1200 ⁇ . It is considered that such an embodiment can efficiently adsorb urine odor-causing substances such as phenol, cresol, and phenylacetic acid.
  • the "hydrophobic polymer" in the hydrophobic porous polymer adsorbent is a polymer having a low affinity for water, and the contact angle is, for example, when the static contact angle with water is measured. It means a polymer having a temperature of 90 ° or higher.
  • the hydrophobic porous polymer adsorbent is a porous polymer obtained by copolymerizing a hydrophobic non-crosslinkable monomer, a crosslinkable monomer and the like from the viewpoint of having a hydrophobic composition. good.
  • the hydrophobic non-crosslinkable monomer include monovinyl aromatic monomers such as styrene, methylstyrene, vinylnaphthalene, vinylpyridine, phenyl (meth) acrylate, and benzyl (meth) acrylate; vinyl acetate and vinyl propionate.
  • vinyl carboxylate monomers ethyl (meth) acrylates, (meth) acrylic acid aliphatic esters such as propyl (meth) acrylates and the like can be mentioned.
  • inorganic adsorbents such as zeolite (for example, zeolite), which are generally known as adsorbents, have high polarity and a small average pore diameter of less than 20 ⁇ , so that they have the ability to adsorb odor-causing substances. Is insufficient, and as a result, the deodorant property is also insufficient.
  • zeolite for example, zeolite
  • adsorbents have high polarity and a small average pore diameter of less than 20 ⁇ , so that they have the ability to adsorb odor-causing substances. Is insufficient, and as a result, the deodorant property is also insufficient.
  • hydrophobic crosslinkable monomer examples include aromatic monomers having two or more vinyl groups such as divinylbenzene, divinyltoluene, and divinylnaphthalene; ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and propylene glycol.
  • Di (meth) acrylates such as di (meth) acrylates, polypropylene glycol di (meth) acrylates; trimethylolpropane tri (meth) acrylates, tetramethylolmethanetri (meth) acrylates, pentaerythritol tetrakis (meth) acrylates.
  • Examples include polyhydric alcohol esters of na (meth) acrylic acid.
  • the average pore diameter of the hydrophobic porous polymer adsorbent in the water-absorbent resin composition is preferably 20 to 1200 ⁇ , preferably 50 to 1000 ⁇ , from the viewpoint of reducing urine odor. It is more preferably 60 to 950 ⁇ , even more preferably 70 to 800 ⁇ , even more preferably 80 to 750 ⁇ , and even more preferably 90 to 730 ⁇ . It is considered that urine odor-causing substances such as phenol, cresol, and phenylacetic acid can be efficiently adsorbed by setting the average pore diameter within the range.
  • the average pore diameter of the hydrophobic porous polymer adsorbent in the water-absorbent resin composition may exceed 100 ⁇ , for example, 150 ⁇ or more, 200 ⁇ or more, 250 ⁇ or more. You may.
  • the average pore diameter of the hydrophobic porous polymer adsorbent in the water-absorbent resin composition, may be more than 100 ⁇ and 900 ⁇ or less.
  • the hydrophobic porous polymer adsorbent according to the embodiment of the present invention is relatively hydrophobic, and its pore size may be several tens to several hundreds of ⁇ .
  • the average pore diameter of the hydrophobic porous polymer adsorbent can be obtained as follows.
  • the BET specific surface area of the hydrophobic porous polymer adsorbent in the water-absorbent resin composition is preferably 20 to 2000 m 2 / g from the viewpoint of reducing urine odor. More preferably, they are 50 to 2000 m 2 / g, 70 to 1200 m 2 / g, 80 to 1000 m 2 / g, 90 to 900 m 2 / g, and 100 to 850 m 2 / g.
  • the average particle size of the hydrophobic porous polymer adsorbent in the water-absorbent resin composition is preferably 1 to 2000 ⁇ m from the viewpoint of mixing with the water-absorbent resin. It is more preferably 10 to 1500 ⁇ m, further preferably 50 to 1000 ⁇ m, and even more preferably 60 to 800 ⁇ m.
  • the average particle size of the hydrophobic porous polymer adsorbent was photographed using a scanning electron microscope (manufactured by Keyence Co., Ltd .; VF-9800) at a magnification of 50 to 500 times, and photographed using image analysis software. Twenty points are randomly selected as a sample from the images obtained and the particle size is measured.
  • the amount of the hydrophobic porous polymer adsorbent added is preferably 0.05 to 10 parts by mass with respect to 100 parts by mass of the water-absorbent resin from the viewpoint of the effect of suppressing urine odor. It is more preferably 0.1 to 8 parts by mass, further preferably 0.15 to 5 parts by mass, particularly preferably 0.2 to 3 parts by mass, and 0.3 parts by mass or more, 0.4 mass by mass. More than parts, 0.5 parts by mass or more, more than 0.5 parts by mass, or 0.7 parts by mass or more are also preferable. Such a preferable addition amount is consistent with a preferable content in the water-absorbent resin composition.
  • the content of the hydrophobic porous polymer adsorbent in the water-absorbent resin composition is preferably 0.05 to 10 parts by mass with respect to 100 parts by mass of the water-absorbent resin. , More preferably 0.1 to 8 parts by mass, further preferably 0.15 to 5 parts by mass, particularly preferably 0.2 to 3 parts by mass, 0.3 parts by mass or more, 0.4 parts by mass.
  • mass or more 0.5 parts by mass or more, more than 0.5 parts by mass, or 0.7 parts by mass or more is also preferable. If the content is less than the preferable addition amount, the urine odor suppressing effect may not be sufficiently obtained. Further, when the content is larger than the preferable addition amount, the water absorption ratio of the water-absorbent resin may decrease.
  • hydrophobic porous polymer adsorbent examples include styrene-based and methacrylic acid ester-based synthetic adsorbents manufactured by Purolite Co., Ltd .: Chromalite AD series, Chromalite PCG series, Purosorb PAD series and the like; Mitsubishi Chemical Co., Ltd .: Styrene-based or (meth) acrylic synthetic adsorbents such as Diaion HP series and Diaion HP2MGL; Organo Co., Ltd .: Styrene-based or (meth) such as Amberlite XAD series and Amberlite FPX series.
  • Acrylic synthetic adsorbents examples thereof include porous polymers having a phenyl group described in JP-A-2017-140332.
  • the hydrophobic porous polymer adsorbent may be used alone or in combination of two or more.
  • Total specific surface area per 1 g of water-absorbent resin is the total specific surface area of the hydrophobic porous polymer adsorbent added per unit amount of the water-absorbent resin, and is calculated by the following formula. Can be asked.
  • the total specific surface area per 1 g of the water-absorbent resin is preferably 0.2 m 2 or more, more preferably 0.3 m 2 or more, and further preferably 0.4 m 2 or more from the viewpoint of suppressing urine odor.
  • the upper limit is not particularly limited, but from the viewpoint of economy, for example, 100 m 2 or less is preferable.
  • the preferable total specific surface area per 1 g of such a water-absorbent resin is consistent with the preferable total specific surface area in the water-absorbent resin composition.
  • the total specific surface area per 1 g of the water-absorbent resin is preferably 0.2 m 2 or more, more preferably 0, from the viewpoint of suppressing urine odor. .3m 2 or more, more preferably 0.4m 2 or more, and 1.0m 2 or more, 1.5m 2 or more, 2.0m 2 or more, 2.5m 2 or more, 3.0m 2 or more, 3.5m 2 or more.
  • the upper limit is not particularly limited, but from the viewpoint of economy, for example, 100 m 2 or less is preferable, and 50 m 2 or less, 40 m 2 or less, 30 m 2 or less, 20 m 2 or less, or 10 m 2 or less may be used.
  • the hydrophobic porous polymer adsorbent may be prepared by purchasing a commercially available product.
  • the water-absorbent resin composition comprises a resin having a nitrogen-containing heterocycle.
  • basic compounds such as ammonia and amines generated by decomposition of urea and amino acids can be considered.
  • the nitrogen-containing heterocycle is typically basic like ammonia and the like, it is considered that it does not have high adsorption performance for basic substances derived from urine.
  • the resin having such a basic nitrogen-containing heterocycle had a better deodorizing ability.
  • a surface-crosslinked water-absorbing resin is used as a method of mixing the water-absorbent resin and the resin having a nitrogen-containing heterocycle. It is preferable to add a resin having a nitrogen-containing heterocycle to the resin.
  • a resin having a nitrogen-containing heterocycle is mixed with the base polymer before surface cross-linking, the base polymer and the resin having a nitrogen-containing heterocycle undergo a cross-linking reaction due to the subsequent heat treatment at the time of surface cross-linking, which has a deodorizing effect. May disappear.
  • the oxazoline ring is opened by the heat at the time of crosslinking. Then, the residue interacts with the functional group of the constituent unit constituting the water-absorbent resin to cause a cross-linking reaction. Therefore, there is a possibility that the specific functional group (nitrogen-containing heterocycle) necessary for exhibiting the deodorizing action disappears and the deodorizing effect disappears.
  • an example of using a compound having an oxazoline group or the like as a cross-linking agent in a water-absorbent resin has been conventionally known, but in such an example, a cross-linking reaction occurs and a nitrogen-containing heterocycle does not exist. The deodorizing effect like that cannot be obtained. In that sense, the resin having a nitrogen-containing heterocycle should not be added in the surface cross-linking step. Therefore, according to one embodiment of the present invention, in the method for producing a water-absorbent resin composition, after the resin having a nitrogen-containing heterocycle having a function as a cross-linking agent is added, a heating step at a high temperature is performed. It is preferable not to apply. Therefore, even if the heating step is performed, the temperature is less than 100 ° C., 90 ° C. or lower, 80 ° C. or lower, 70 ° C. or lower, or 65 ° C. or lower.
  • the resin having the nitrogen-containing heterocycle is a polymer that is water-insoluble or can be dispersed in water having a LogP of 1.5 or more. That is, the resin having a nitrogen-containing heterocycle is added to the water-absorbent resin in the form of water dispersion. According to one embodiment of the present invention, the resin having a nitrogen-containing heterocycle is added to the water-absorbent resin in a form in which the resin has no dispersion in some dispersion medium, that is, in a dry form.
  • LogP in the present application refers to the n-octanol / water partition coefficient (Log10Pow), and is referred to as OECD Test Guideline (OECD Board Decision "C (81) 30 Final Attachment 1") 107 or Japanese Industrial Standard Z7260-107 (2000). It may be obtained by "measurement of partition coefficient (1-octanol / water) -flask shaking method", but in the present invention, the value obtained by the following calculation method is used in principle.
  • VMLogP (i) and MSLogP (i) below are calculated by ACD / LogP DB Release 100 Product Version 10.01 manufactured by Advanced Chemistry Development under the condition of 25 ° C. Unless otherwise specified, LogP is a so-called common logarithmic value having a base of 10.
  • the virtual monomer unit is based on the repeating structure in the polymer, and may not match the monomer actually used in the production of the polymer. Specifically, it is determined as follows.
  • the monomer is a ring-opening polymerizable monomer
  • two methyl groups are introduced into the ring-opening unit of the cyclic structure (for example, an epoxy group in the case of ethylene oxide).
  • a methyl group is introduced into the polycondensation unit (for example, ester, ether, amide).
  • a methyl group may be introduced using each polyether unit as a polycondensation unit.
  • a polymer unsaturated monomer for example, a polyalkylene oxide having an unsaturated group (for example, a monoacrylate of methoxypolyethylene glycol)
  • the polymer unit (for example, polyethylene oxide) in the monomer may be decomposed to introduce a methyl group, and the decomposable unit (for example, COOH of acrylic acid) may also be methylated.
  • the monomer (1) becomes ethylene and the VMLogP (1) becomes LogP of n-butane.
  • the monomer (1) is styrene
  • the monomer (2) is butadiene
  • VMLogP (1) is LogP of 2-phenylbutane
  • VMLogP (2) is 3-hexene. It becomes LogP.
  • VMLogP (1) becomes LogP of 3-butanol.
  • the monomer (1) is ethylene oxide
  • VMLogP (1) is LogP of methyl-n-propyl ether.
  • the monomer (2) becomes aspartic acid and VMLogP (1) becomes LogP of N-methyl-methylaspartic acid ester.
  • the VMLogP (i) is corrected by the molar ratio (MolRatio) (MR (i): i is the same as above) of each monomer constituting the polymer for which LogP is obtained (VMLogP (i) ⁇ MR (i). ).
  • the MR (j) of the monomer (j) that does not constitute the polymer is 0, and if it is a homopolymer, the MR (i) is 1.
  • VMLogP (i) is a calculated value of "n-octanol-water partition coefficient" at 25 ° C. of a virtual monomer unit (Virtual Monomer (VM)) in which both ends of the polymer repeating unit (i) are methylated.
  • MR (i) is the “mol ratio (MolRatio (MR)”) of the repeating unit (i).)
  • the acrylic acid homopolymer is 1.12 and the styrene homopolymer is 4.09.
  • Such a resin having a nitrogen-containing heterocycle which is water-insoluble or a polymer dispersible in water having LogP of 1.5 or more does not easily penetrate into the water-absorbent resin when used. Therefore, it is possible to suppress the interaction between the functional group (particularly the carboxyl group) of the constituent unit constituting the water-absorbent resin and the functional group effective for deodorization (nitrogen-containing heterocycle) inside the water-absorbent resin as much as possible. can. Therefore, a functional group effective for deodorization (that is, a nitrogen-containing heterocycle) can remain in the vicinity of the surface of the water-absorbent resin, and a high adsorption effect on urine odor-causing substances can be exhibited.
  • a functional group effective for deodorization that is, a nitrogen-containing heterocycle
  • water-insoluble means that the mass (solubility) dissolved in ion-exchanged water at 25 ° C. is 1 g or less (1% by mass or less). Further, “dissolution” means a state in which no suspended matter or precipitate can be visually confirmed when irradiated with light.
  • the LogP of the resin having a nitrogen-containing heterocycle is preferably 1.5 or more, more preferably 2.0 or more, and further preferably 3.0 or more.
  • the upper limit of LogP is, for example, less than 4.09. Being a water-insoluble or dispersible polymer with LogP of 1.5 or more means that the resin having a nitrogen-containing heterocycle is in the form of particles.
  • the average particle size of the resin having a nitrogen-containing heterocycle is preferably 10 to 250,000 nm, preferably 30 to 600 nm. Is more preferable, and 50 to 300 nm is even more preferable.
  • the method for measuring the average particle size of the resin having a nitrogen-containing heterocycle can be measured by an appropriate method according to the characteristics of the resin. If the particles are contained in the aqueous dispersion, the average particle size (volume average particle size) can be measured by using a particle size distribution measuring device (“NICOMP Model 380” manufactured by Partricle Sigmas Systems Co., Ltd.) by a dynamic light scattering method. For powdery particles, the average particle size (volume average particle size) can be calculated by measuring 50 particles using a desktop scanning electron microscope (“JCM-6000” manufactured by JEOL Ltd.).
  • the amount of the resin having a nitrogen-containing heterocycle is preferably 0.01 to 30 parts by mass with respect to 100 parts by mass of the water-absorbent resin from the viewpoint of the effect of suppressing urine odor. It is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, still more preferably 0.2 to 3 parts by mass, and particularly 0.3 parts by mass or more, 0. More than 3 parts by mass, more than 0.5 parts by mass, 1.0 part by mass or more, more than 1.0 part by mass, 1.5 parts by mass or more, or 2.0 parts by mass or more is preferable.
  • the content of the resin having a nitrogen-containing heterocycle in the water-absorbent resin composition is preferably 0.01 to 30 parts by mass, more preferably 0.05 to 10. It is parts by mass, more preferably 0.1 to 5 parts by mass, particularly preferably 0.2 to 3 parts by mass, and particularly 0.3 parts by mass or more, more than 0.3 parts by mass, and 0.5 parts. More than parts by mass, 1.0 part by mass or more, more than 1.0 part by mass, 1.5 parts by mass or more, or 2.0 parts by mass or more is preferable.
  • a specific structure called a nitrogen-containing heterocycle contributes to the effect of reducing urine odor.
  • the content of the nitrogen-containing heterocycle present in the water-absorbent resin composition of the present invention is defined by an index called "absence of nitrogen-containing heterocycle".
  • the abundance of the nitrogen-containing heterocycle means the ratio of the peak height derived from the nitrogen-containing heterocycle to the peak height derived from the water-absorbent resin detected by the FT-IR measurement of the water-absorbent resin composition. ..
  • the abundance is measured 5 times for the same sample, and the arithmetic mean value of 3 values excluding the maximum value and the minimum value is adopted.
  • the abundance of the nitrogen-containing heterocycle is 3.0% or more, 4.0% or more, 5.0% or more, 6.0% or more, 7.0% or more, 8.0. % Or more, 10.0% or more, 12.0% or more, 13.0% or more, 14.0% or more, 15.0% or more, 20.0% or more, 30.0% or more, 40.0% or more Or, 42.0% or more is preferable. If the abundance of the nitrogen-containing heterocycle is less than 3.0%, the malodor caused by urine may not be sufficiently reduced. In one embodiment of the present invention, the abundance of the nitrogen-containing heterocycle is 200% or less, or 150% or less.
  • the absorption ratio of the water-absorbent resin composition may decrease, or the hydrophobicity may be too high to reduce the water absorption rate. Therefore, in one embodiment of the present invention, it contains at least one component of a water-absorbent resin, a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle, and the span value is 1.10 or less.
  • the water-absorbent resin composition contains the resin having the nitrogen-containing heterocycle, the water-absorbent resin composition in which the abundance of the nitrogen-containing heterocycle is 3.0% or more is provided.
  • the water-absorbent resin in the water-absorbent resin composition from which the abundance of the nitrogen-containing heterocycle is calculated is a polyacrylic acid (salt) -based water-absorbent resin.
  • the nitrogen-containing heterocycle preferably has at least one heteroatom, more preferably two or more. With such an embodiment, the desired effect of the present invention can be achieved more efficiently. According to one embodiment of the present invention, it is preferable that the nitrogen-containing heterocycle has 3 or less heteroatoms. With such an embodiment, the desired effect of the present invention can be achieved more efficiently.
  • the nitrogen-containing heterocycle is not limited to containing only a nitrogen atom, and is not limited to containing an oxygen atom or a sulfur atom.
  • the nitrogen-containing heterocycle includes a 6-membered nitrogen-containing heterocycle such as a pyridine ring, a pyrazine ring, a triazine ring, a pyrimidine ring, and a pyridazine ring, an imidazole ring, an oxazole ring, and a thiazole ring.
  • a 6-membered nitrogen-containing heterocycle such as a pyridine ring, a pyrazine ring, a triazine ring, a pyrimidine ring, and a pyridazine ring, an imidazole ring, an oxazole ring, and a thiazole ring.
  • an oxazoline ring, a triazine ring, and a pyridine ring are preferable, and an oxazoline ring and a triazine ring are more preferable, in order to more efficiently exert the desired effect of the present invention.
  • the resin having a nitrogen-containing heterocycle is a polymer having an oxazoline group (an oxazoline group-containing polymer).
  • the amount of oxazoline groups is preferably 0.1 mmol / g to 10 mmol / g, more preferably 0.5 mmol. It is / g to 8 mmol / g.
  • the oxazoline group-containing polymer has a structural unit derived from the oxazoline group-containing monomer.
  • the oxazoline group-containing polymer has a structural unit derived from an oxazoline group-containing monomer and a structural unit derived from another monomer other than the oxazoline group-containing monomer.
  • any suitable monomer having an ethylenically unsaturated hydrocarbon group and an oxazoline group can be adopted.
  • examples of such an oxazoline group-containing monomer include 2-vinyl-2-oxazoline, 5-methyl-2-vinyl-2-oxazoline, 4,4-dimethyl-2-vinyl-2-oxazoline, and 4, Examples thereof include 4-dimethyl-2-vinyl-5,5-dihydro-4H-1,3-oxazoline, 2-isopropenyl-2-oxazoline, and 4,4-dimethyl-2-isopropenyl-2-oxazoline.
  • any suitable monomer can be adopted as long as it does not have an oxazoline group.
  • examples of such other monomers include N-vinyllactam-based monomers such as N-vinylpyrrolidone; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (.
  • (Meta) acrylamide Vinyl aryl monomers such as styrene, ⁇ -methylstyrene, divinylbenzene, vinyltoluene, inden, vinylnaphthalene, phenylmaleimide, vinylaniline; alkene such as ethylene, propylene, butadiene, isobutylene, octene; acrylic acid Vinyl carboxylate such as vinyl and vinyl propionate; Vinyl ether such as methyl vinyl ether, ethyl vinyl ether and butyl vinyl ether; Vinyl ethylene carbonate and its derivatives; N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminoethyl ( Meta) Unsaturated amines such as acrylamide, vinyl pyridine, vinyl imidazole and salts thereof or quaternized products thereof; vinyl cyanide-based monomers such as acryliconitrile and methacrylonitrile; and the like.
  • the ratio of the structural units derived from the oxazoline group-containing monomer is preferably 15 mol% to 95 mol%, more preferably 20 mol%, based on 100 mol% of the total structural units. It is ⁇ 95 mol%, more preferably 30 mol% to 90 mol%, still more preferably 40 mol% to 85 mol%.
  • the resin having a nitrogen-containing heterocycle is an amino resin.
  • the amino-based resin include a condensate of an amino compound and formaldehyde.
  • the amino compound include urea, thiourea, and polyfunctional amino compounds. Among them, a polyfunctional amino compound is preferably used, and as described above, a polyfunctional amino compound having a triazine-returning structure is more preferably used.
  • Examples of the polyfunctional amino compound having a triazine ring structure include melamine; an amino compound represented by the general formula (1); guanamines such as benzoguanamine, cyclohexanecarboguanamine, cyclohexenecarboguanamine, acetoguanamine, norbornenecarboguanamine, and spirognamine. Compounds; and the like. Among these, melamine and benzoguanamine are preferable. As the amino compound, only one kind may be used, or two or more kinds may be used.
  • R 1 represents an alkyl group which is the same or different and may have a hydrogen atom or a substituent, and at least one of R 1 is an alkyl group which may have a substituent.
  • R 1 is preferably a hydrogen atom or a hydroxyalkyl group.
  • the resin can be obtained by reacting the above-mentioned amino compound with formaldehyde by an arbitrary appropriate method (condensation reaction).
  • Examples of the method for producing a resin formed from an amino resin include JP-A-2000-256432, JP-A-2002-293854, JP-A-2002-293855, JP-A-2002-293856, and JP-A.
  • resin particles formed from an amino-based resin having a crosslinked structure can be produced by mixing an acid catalyst such as dodecylbenzenesulfonic acid or sulfuric acid with an aqueous medium to be dispersed and curing the mixture.
  • an acid catalyst such as dodecylbenzenesulfonic acid or sulfuric acid
  • Both the step of forming the condensate oligomer and the step of forming the crosslinked amino resin particles are preferably carried out in a state of being heated at a temperature of 50 ° C to 100 ° C.
  • the resin having a nitrogen-containing heterocycle is a melamine or formaldehyde condensate, and contains the following structural units.
  • the resin having a nitrogen-containing heterocycle is a polymer having a pyridine ring as a repeating constituent unit.
  • a polymer having a pyridine ring as a repeating constituent unit there are polymers made from 2-vinylpyridine and 4-vinylpyridine, polymers of these methylated quaternary salts, 4-aminopyridine branched polystyrene and the like.
  • the weight average molecular weight of the resin having a nitrogen-containing heterocycle is preferably 5,000 or more, and more preferably 10,000 or more.
  • the upper limit is appropriately determined, but is usually 10 million or less, preferably 1 million or less.
  • the weight average molecular weight of the resin having a nitrogen-containing heterocycle is measured by GPC.
  • the resin having a nitrogen-containing heterocycle may be used alone or in combination of two or more.
  • the resin having a nitrogen-containing heterocycle may be prepared by purchasing a commercially available product.
  • the water-absorbent resin composition comprises a binder that binds the water-absorbent resin and the component.
  • the water-absorbent resin composition is different from the water-absorbent resin; at least one component of the hydrophobic porous polymer adsorbent and the resin having a nitrogen-containing heterocycle; There will be new materials. When different materials are present, they tend to segregate from each other. When segregation occurs, a stable deodorizing effect may not be obtained.
  • the inclusion of the binder binds the water-absorbent resin to at least one component of the hydrophobic porous polymer adsorbent and the resin having a nitrogen-containing heterocycle. , It is evenly distributed in the water-absorbent resin composition, and a stable deodorizing effect can be obtained.
  • the binder is a polyol.
  • the polyol means a compound having two or more hydroxyl groups, and examples thereof include propylene glycol, ethylene glycol, tetramethylene glycol, diethylene glycol, dipropylene glycol, polyethylene glycol, and glycerin.
  • the binder may be contained in a surface cross-linking agent used for surface cross-linking of a water-absorbent resin (base polymer).
  • At least one of the surface cross-linking agents may also have a function as a binder.
  • the binder is a surface cross-linking agent remaining on the surface of the surface-cross-linked water-absorbent resin. That is, the binder may be a surface cross-linking agent remaining on the surface of the water-absorbent resin after the surface cross-linking treatment.
  • the amount of the binder contained in the water-absorbent resin composition is preferably 0.1 to 10% by mass, more preferably 0.2 to 7% by mass. More preferably, it is 0.3 to 5% by mass. If the amount of binder is less than the preferable amount, the deodorizing effect may not be sufficiently stabilized. Further, when the amount of the binder is larger than the preferable amount, the water absorption ratio of the water-absorbent resin may decrease.
  • the amount of binder contained in the water-absorbent resin composition can be, for example, extracted with physiological saline or the like and measured by a measuring device such as HPLC.
  • the method of adding the binder contained in the water-absorbent resin composition is not particularly limited, and as described above, it may be added at the time of surface treatment, or the water-absorbent resin after surface treatment and the binder. And may be mixed.
  • the molecular weight of the binder is preferably 40 to 800, more preferably 50 to 300, and even more preferably 60 to 200.
  • the molecular weight of the binder can be appropriately measured by a gas chromatograph mass spectrometer (GC-MS), a liquid chromatograph mass spectrometer (LC-MS), a gel filtration chromatography (GPC), or the like.
  • a water-absorbent resin for example, surface-crosslinked
  • a hydrophobic porous polymer adsorbent for example, surface-crosslinked
  • a resin having a nitrogen-containing heterocycle it is preferable to apply torque to uniformly and surely mix at least one component of the water-absorbent resin, the hydrophobic porous polymer adsorbent, and the resin having a nitrogen-containing heterocycle.
  • Examples of the device used for the mixing include a stirring type mixer, a cylindrical type mixer, a double-walled conical type mixer, a V-shaped mixer, a ribbon type mixer, a screw type mixer, and a fluid type rotary desk type.
  • a mixer, an air flow type mixer, a double arm type kneader, an internal mixer, a crushing type kneader, a rotary mixer, a screw type extruder and the like are suitable.
  • the rotation speed is preferably 5 rpm to 10000 rpm, more preferably 10 rpm to 2000 rpm.
  • the water-absorbent resin composition contains a chelating agent.
  • the amount of the chelating agent used is preferably 0 to 3 parts by mass, more preferably 0.001 to 1 part by mass, and particularly preferably 0.05 to 0.5 part by mass with respect to 100 parts by mass of the water-absorbent resin. Such a preferred amount is consistent with the preferred content in the water-absorbent resin composition.
  • the content of the chelating agent in the water-absorbent resin composition is preferably 0 to 3 parts by mass, preferably 0.001 to 1 part by mass with respect to 100 parts by mass of the water-absorbent resin. Parts are more preferable, and 0.05 to 0.5 parts by mass are particularly preferable.
  • the addition step is appropriately determined after the polymerization step, but they may be added after polymerization, further drying, and especially after surface cross-linking. preferable.
  • the chelating agents that can be used are the chelating agents exemplified in US Patent No. 6599989, No. 6469080, European Patent No. 2163302, etc., particularly non-polymeric chelating agents, further organic phosphorus chelating agents, diethylenetriamine 5 acetic acid or salts thereof.
  • Aminocarboxylic acid-based chelating agents such as ethylenediamine tetraacetic acid or a salt thereof can be used.
  • Step of Adding Anticoloring Agent or Urinary Resistance Improving Agent water-absorbent resins tend to be colored or deteriorated easily. Therefore, in the present invention, ⁇ - is used to prevent coloring and deterioration. It is preferable to further contain a color inhibitor or a urine resistance (weather resistance) improving agent selected from hydroxycarboxylic acids (particularly lactic acid or salts thereof), inorganic or organic reducing agents (particularly sulfur-based inorganic reducing agents). The amount of these used is preferably 0 to 3 parts by mass, more preferably 0.001 to 1 part by mass, and particularly preferably 0.05 to 0.5 part by mass with respect to 100 parts by mass of the water-absorbent resin.
  • a color inhibitor or a urine resistance (weather resistance) improving agent selected from hydroxycarboxylic acids (particularly lactic acid or salts thereof), inorganic or organic reducing agents (particularly sulfur-based inorganic reducing agents).
  • the amount of these used is preferably 0 to 3 parts by mass, more preferably 0.001
  • the content of the anticoloring agent or the urine resistance improving agent in the water-absorbent resin composition is independently 0 to 0 to 100 parts by mass of the water-absorbent resin. 3 parts by mass is preferable, 0.001 to 1 part by mass is more preferable, and 0.05 to 0.5 parts by mass is particularly preferable.
  • the addition step is appropriately determined after the polymerization step.
  • the reducing agent is consumed in the polymerization, further after the polymerization. Is preferably added after drying, especially after surface cross-linking.
  • Examples of the ⁇ -hydroxycarboxylic acid include malic acid, succinic acid, lactic acid and salts thereof (particularly monovalent salts) exemplified in US Patent Application Publication No. 2009/0312183.
  • Examples of the inorganic or organic reducing agent (particularly sulfur-based inorganic reducing agent) that can be used include sulfur-based reducing agents exemplified in US Patent Application Publication No. 2010/0062252, and particularly sulfite or hydrogen sulfite.
  • the water-absorbent resin composition may further contain an antibacterial agent.
  • an antibacterial agent As for the bad odor caused by urine, the putrid odor and pungent odor generated by the decomposition of organic substances in urine due to the proliferation of microorganisms and the like over time increase.
  • an antibacterial agent not only the suppression of the initial urine odor but also the suppression of the urine odor after a medium to long-term lapse by suppressing the growth of microorganisms over time can be achieved.
  • the procedure for mixing the water-absorbent resin and the antibacterial agent is not particularly limited.
  • the antibacterial agent may be added to the base polymer before surface cross-linking and then the base polymer may be surface-crosslinked.
  • the antibacterial agent has the effect of suppressing the growth of bacteria such as Staphylococcus aureus, Escherichia coli, and ammonia-producing bacteria.
  • the antibacterial agent is an inorganic antibacterial agent that carries an antibacterial metal such as Ag, Cu, Zn as an active ingredient on an inorganic carrier or contains it as a salt or complex of an organic compound, and an organic antibacterial agent that does not contain an antibacterial metal. Can be roughly divided into.
  • any inorganic antibacterial agent or organic antibacterial agent having an effect of suppressing the growth of microorganisms over time can be preferably used.
  • organic antibacterial agents are more preferable because they can eliminate concerns about adverse effects on the human body caused by antibacterial metals.
  • the inorganic antibacterial agent include silicate-based agents in which an antibacterial metal is carried on silicates such as zeolite, silica gel, calcium silicate, and clay mineral; zirconium phosphate, calcium phosphate, aluminum phosphate, and hydroxy. Phosphates carrying antibacterial metals on phosphates such as apatite; single metals such as antibacterial metal nanoparticles; antibacterial metal compounds such as halides and oxides of antibacterial metals; organic compounds, polymers, etc. Examples thereof include antibacterial metal salts or complexes.
  • the water-absorbent resin composition does not contain an inorganic antibacterial agent (an antibacterial metal (for example, Ag) carried on silicates (for example, zeolite)).
  • an inorganic antibacterial agent for example, Ag
  • silicates for example, zeolite
  • the content ratio may be less than 10 mass ppm, 9 mass ppm or less, 7 mass ppm or less, or 5 mass ppm or less.
  • organic antibacterial agent examples include alcohol compounds such as 2-bromo-2-nitro-1,3-propanediol and N- (2-hydroxypropyl) -aminomethanol; 3-methyl-4- Isopropylphenol (isopropylmethylphenol), 2-isopropyl-5-methylphenol, o-phenylphenol, o-phenylphenol sodium, chloroxylenol (4-chloro-3,5-dimethylphenol), p-chlorom-cresol, Phenolic compounds such as tribromophenol and 4-chloro-2-phenylphenol; ester compounds such as fatty acid monoglyceride, p-hydroxybenzoic acid ester and sucrose fatty acid ester; 2,4,4'-trichloro-2'- Ethereal compounds such as hydroxydiphenyl ether; nitrile compounds such as 2,4,5,6-tetrachloroisophthalonitrile, 1,2-dibromo-2,4-dicyanobutane; chlor
  • amphoteric and anionic surfactant compounds examples thereof include amphoteric and anionic surfactant compounds.
  • water-soluble and water-dispersible antibacterial agents are particularly preferably used, and among them, phenol-based compounds and quaternary ammonium salt-based compounds are used.
  • Biguanide compounds, amphoteric and anionic surfactant compounds are preferably used.
  • the amount of the antibacterial agent added to the water-absorbent resin is preferably 0.001 to 5% by mass, more preferably 0, from the viewpoint of the effect of suppressing the generation of putrefactive odor and pungent odor. It is 0.01 to 4% by mass, more preferably 0.03 to 3% by mass, and particularly preferably 0.05 to 2% by mass.
  • a granulation step, a granulation step, a fine powder removal step, a fine powder recovery step, a fine powder reuse step, a step of adding other additives, and removal of the fine powder in addition to the above-mentioned steps, a granulation step, a granulation step, a fine powder removal step, a fine powder recovery step, a fine powder reuse step, a step of adding other additives, and removal of the fine powder.
  • the iron process and the like can be carried out as needed. Further, at least one kind of process selected from a transportation process, a storage process, a packing process, a storage process, and the like may be further included.
  • the granulation step includes a step of classifying and removing fine powder after the surface cross-linking step, and a step of classifying and pulverizing when the water-absorbent resin aggregates and exceeds a desired size.
  • the step of reusing the fine powder includes a step of turning the fine powder into a large water-containing gel as it is or in a granulation step and adding it to a water-containing gel or the like as a raw material in any step of the manufacturing step of the water-absorbent resin.
  • the anticoloring agent or the urine resistance improving agent in order to impart various functions to the water absorbing agent, other organic powders such as oxidizing agents and metal soaps, pulp and thermoplastic fibers are selected.
  • additives may be added together with the anticoloring agent or the urine resistance improving agent, or in place of the anticoloring agent or the urine resistance improving agent.
  • these other additives can be mixed at the same time as or separately from the surface cross-linking agent. That is, the water-absorbent resin composition of the present invention may also contain such other additives.
  • the water-absorbent resin composition does not have to contain a material having a function of polymerizing a phenolic compound.
  • the water-absorbent resin composition may not contain a natural deodorant component (particularly, a plant component).
  • the water-absorbent resin composition has a span value of 1.10 or less. If the span value exceeds 1.10, the desired effect of the present invention cannot be achieved. According to the embodiment of the present invention, the span value is 0.40 or more. According to such an embodiment, the desired effect of the present invention can be efficiently achieved. According to the embodiment of the present invention, it is preferably 0.40 to 1.10, more preferably 0.45 to 1.05, and even more preferably 0.50 to 1.00.
  • the water-absorbent resin preferably further has the following characteristics.
  • the mass average particle size D (50%) of the water-absorbent resin composition is preferably 300 ⁇ m or more, more preferably 305 ⁇ m or more, further preferably 310 ⁇ m or more, and particularly preferably 315 ⁇ m or more. Further, 600 ⁇ m or less is preferable, 550 ⁇ m or less is more preferable, 500 ⁇ m or less is further preferable, and 450 ⁇ m or less is particularly preferable. As the range of the mass average particle diameter D (50%), a range arbitrarily combined from the above upper and lower limit values is applied.
  • the water-absorbent composition has an absorption ratio under no pressure (CRC) and absorption under pressure.
  • the magnification (AAP) can be controlled in a well-balanced manner. That is, by keeping it within the above range, the absorption ratio under no pressure (CRC) and the absorption ratio under pressure (AAP) can be increased, the roughness of the particles of the water-absorbent resin can be suppressed, and disposable diapers, sanitary napkins, etc. When used in an absorbent article, it can improve the feel and fit.
  • the CRC (centrifugal force holding capacity) of the water-absorbent resin composition is usually 5 g / g or more, preferably 20 g / g or more, more preferably 24 g / g or more, still more preferably. It is 30 g / g or more.
  • the upper limit is not particularly limited, and a higher value is preferable, but from the viewpoint of balance with other physical characteristics, it is preferably 70 g / g or less, more preferably 50 g / g or less, still more preferably 45 g / g or less.
  • the CRC centrifugal holding capacity
  • it can be appropriately selected within the range of the above-mentioned upper limit value and the above-mentioned lower limit value.
  • any range can be selected, such as 5 to 70 g / g, 20 to 50 g / g, and 24 to 45 g / g.
  • the CRC When the CRC is less than 5 g / g, the water absorption amount of the water-absorbent resin composition is small, and it is not suitable as an absorber for absorbent articles such as disposable diapers. Further, when the CRC exceeds 70 g / g, the rate of absorbing body fluids such as urine and blood decreases, so that it is not suitable for use in high water absorption rate type disposable diapers and the like.
  • the CRC can be controlled by an internal cross-linking agent, a surface cross-linking agent, or the like.
  • the AAP (water absorption ratio under pressure) of the water-absorbent resin composition is preferably 5 g / g or more, more preferably 8 g / g or more, still more preferably 10 g / g or more, still more preferably. It is 12 g / g or more, preferably 14 g / g or more, still more preferably 18 g / g or more, and even more preferably 22 g / g or more.
  • the upper limit is not particularly limited, but is preferably 30 g / g or less.
  • the above AAP is less than 5 g / g, when it is actually used in a disposable diaper or the like, the amount of absorption when pressure is applied to the absorbent body decreases, so that it is suitable as an absorber for absorbent articles such as disposable diapers. not.
  • the AAP can be controlled by the particle size, the surface cross-linking agent, or the like.
  • the contact angle of the water-absorbent resin composition is preferably 35 ° or more, more preferably 40 ° or more, and more preferably 45 ° or more. More preferably, 50 ° or more, 54 ° or more, 55 ° or more, 56 ° or more, or more than 100 ° is also even more preferable.
  • the contact angle has such a lower limit
  • the absorption of urine, etc. by the water-absorbent resin is delayed.
  • the diffusibility of urine or the like is improved. Therefore, the area that comes into contact with the water-absorbent resin such as urine increases, and the effective area of the deodorant can be utilized. Furthermore, the effect of reducing urine return can be expected.
  • the contact angle of the water-absorbent resin composition is preferably 120 ° or less, and more preferably the contact angle is 110 ° or less.
  • the hydrophobic porous polymer adsorbent is a styrene-based adsorbent.
  • the resin having a nitrogen-containing heterocycle is a polymer that is water-insoluble or dispersible in water having a LogP of 1.5 or more.
  • the amount of the resin having the nitrogen-containing heterocycle added is more than 0.3 parts by mass, more than 0.5 parts by mass, and 1.0 part by mass with respect to 100 parts by mass of the water-absorbent tree. Ultra, 1.5 parts by mass or more, or 2.0 parts by mass or more.
  • the nitrogen-containing heterocycle contains two heteroatoms.
  • the amount of the resin having a nitrogen-containing heterocycle added is such that the resin having a nitrogen-containing heterocycle is water-insoluble or a polymer having a LogP of 1.5 or more dispersible in water, and the resin having a nitrogen-containing heterocycle is added. It is more than 0.3 parts by mass, more than 0.5 parts by mass, more than 1.0 part by mass, 1.5 parts by mass or more, or 2.0 parts by mass or more with respect to 100 parts by mass of the water-absorbent resin. Further, the nitrogen-containing heterocycle contains two heteroatoms.
  • the water-absorbent resin composition binds the water-absorbent resin to at least one component of the hydrophobic porous polymer adsorbent and the resin having a nitrogen-containing heterocycle.
  • the water-absorbent resin composition contains a chelating agent.
  • the contact angle of the water-absorbent resin composition is 50 ° or more, 55 ° or more, or 100 ° or more.
  • the total specific surface area of the hydrophobic porous polymer adsorbent per 1 g of the water-absorbent resin is more than 2.5 m 2 or more than 3.0 m 2 or more than 3.5 m 2 . be.
  • the abundance of the nitrogen-containing heterocycle is 7.0% or more, 14.0% or more, or 42.0% or more.
  • the water-absorbent resin composition according to the present invention is preferably used mainly as an absorbent body (absorbent layer) for absorbent articles such as disposable diapers and menstrual napkins, and the amount used per absorbent article is large. , It is more preferable to use it as an absorber (absorbent layer) of an absorbent article. Therefore, in one embodiment of the present invention, an absorber containing a water-absorbent resin composition and hydrophilic fibers is provided.
  • the absorber means a sheet-shaped, fibrous, or tubular shape of a particulate water-absorbing agent, and is preferably molded into a sheet shape to form an absorbent layer.
  • an absorbent material such as pulp fiber, an adhesive, a non-woven fabric, or the like can be used in combination for molding.
  • the amount of the water-absorbing agent in the absorber (absorbent layer) (hereinafter referred to as "core concentration") is preferably in the range of 20 to 100% by mass, more preferably 30 to 90% by mass. The range is, more preferably 40 to 80% by mass.
  • the core concentration is less than 20% by mass, the amount of the water-absorbent resin composition used is small, and for example, the deodorizing performance may not be sufficiently imparted to the entire diaper, which is not preferable.
  • the production method thereof is not particularly limited, and for example, the water-absorbent resin composition and the hydrophilic fiber are used with the above-mentioned core concentration.
  • examples thereof include a method of dry mixing using a mixer such as a mixer at a certain ratio, molding the obtained mixture into a web shape by, for example, air injection, and then compression molding, if necessary.
  • the absorber is preferably compression-molded to a density of 0.001 to 0.50 g / cc and a basis weight of 0.01 to 0.20 g / cm 2 .
  • the absorbent article according to the present invention includes the absorbent body (absorbent layer), and usually includes a liquid-permeable front sheet and a liquid-impermeable back sheet.
  • the absorbent article include disposable diapers and sanitary napkins. Therefore, in one embodiment of the present invention, there is provided an absorbent article comprising an absorber, a liquid permeable surface sheet, and a liquid impermeable back sheet.
  • the absorbent article is, for example, a disposable diaper
  • a liquid-permeable top sheet located on the side that comes into contact with human skin when worn and a liquid-impermeable back sheet located on the outside when worn.
  • the disposable diaper is produced by sandwiching an absorber containing a water-absorbing agent.
  • the disposable diaper is further provided with a member known to those skilled in the art, such as an adhesive tape for fixing the disposable diaper after mounting.
  • the absorbent article according to the present invention contains a specific water-absorbent resin composition
  • an object thereof is a novel water-absorbent resin composition having a deodorizing ability superior to that of the conventional one.
  • the water-absorbent resin composition according to the present invention can be suitably used not only for the disposable diapers and menstrual napkins, but also for pet urine absorbents, urine gelling agents for portable toilets, and the like. More specifically, the present invention is a water-absorbent resin composition, which exhibits excellent deodorizing performance, particularly excellent deodorizing performance against bad odors caused by urine, when sanitary materials such as disposable diapers and incontinence pads are used. Regarding the body and absorbent articles.
  • the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples, and the technical means disclosed in each Example will be used. Examples obtained in appropriate combinations are also included in the scope of the present invention.
  • the electrical equipment used in the examples and comparative examples and the measurement of various physical properties of the water absorbing agent uses a power supply of 200 V or 100 V / 60 Hz.
  • the physical characteristics of the water-absorbing agent were measured under the conditions of room temperature (20 ° C to 25 ° C) and relative humidity of 50 ⁇ 5% RH.
  • "liter” may be expressed as "l” or "L”
  • “mass fraction” may be expressed as "wt%”.
  • (A) Span value The span value of the water-absorbent resin composition conforms to the particle size analysis method of EDANA method WSP220.2, and the sieve used is 850 ⁇ m, 710 ⁇ m, 600 ⁇ m, 500 ⁇ m, 300 ⁇ m, 150 ⁇ m, 45 ⁇ m from the top.
  • the span value was calculated by the following formula.
  • D (90%) is a particle size (unit: ⁇ m) in which the cumulative particle size distribution from the minimum diameter is 90%.
  • D (10%) is a particle size (unit: ⁇ m) in which the cumulative particle size distribution from the minimum diameter is 10%.
  • D (50%) is a particle size (unit: ⁇ m) in which the cumulative particle size distribution from the minimum diameter is 50%.
  • D (90%), D (10%), and D (50%) are cumulative values on a mass basis.
  • the span value can be set to a desired span value by appropriately combining pulverization, classification, granulation and the like.
  • Mass average particle diameter D (50%)
  • the mass average particle size D (50%) of the water-absorbent resin composition conforms to the particle size analysis method of EDANA method WSP220.2, and the sieve used is 850 ⁇ m, 710 ⁇ m, 600 ⁇ m, 500 ⁇ m, 300 ⁇ m, 150 ⁇ m from the top. , 45 ⁇ m in combination and used for measurement.
  • C Absorption factor under no pressurization
  • AAP Absorption rate under pressure
  • this reaction solution was degassed for 30 minutes in a nitrogen gas atmosphere.
  • the reaction solution was supplied to a reactor having a lid on a stainless steel twin bowl type kneader with a jacket having an internal volume of 10 L and having two sigma type blades, and the inside of the reactor was filled with nitrogen while keeping the reaction solution at 30 ° C. Gas replacement.
  • 2.4 parts by mass of sodium persulfate and 0.12 parts by mass of L-ascorbic acid were added as aqueous solutions while stirring the reaction solution, and the polymerization started after about 1 minute.
  • the peak temperature reached about 80 ° C., and 60 minutes after the start of the polymerization, the particulate hydrogel-like polymer was taken out while continuing stirring.
  • the mass average particle size (D50) of the particulate hydrogel polymer was measured by the method described in International Publication No. 2011/126079, and found to be about 1800 ⁇ m.
  • the obtained hydrogel-like polymer was spread on a wire mesh having an opening of 300 ⁇ m and dried with hot air at 150 ° C. for 90 minutes.
  • the dried product was pulverized using a roll mill, further classified and blended with a JIS standard sieve having an opening of 600 ⁇ m to obtain an atypical crushed resin (base polymer) (1).
  • the obtained base polymer (1) has a mass average particle diameter D (50%) of 328 ⁇ m, a particle ratio of more than 850 ⁇ m is 0.0 mass%, and a particle ratio of 710 ⁇ m or more and less than 850 ⁇ m is 0.0 mass%, 600 ⁇ m or more.
  • the particle ratio of less than 710 ⁇ m is 1.4% by mass
  • the particle ratio of 500 ⁇ m or more and less than 600 ⁇ m is 6.1% by mass
  • the particle ratio of 300 ⁇ m or more and less than 500 ⁇ m is 54.9% by mass
  • the particle ratio of 150 ⁇ m or more and less than 300 ⁇ m is 35.
  • the particle ratio of 4% by mass, 45 ⁇ m or more and less than 150 ⁇ m was 2.1% by mass
  • the particle ratio of less than 45 ⁇ m was 0.1% by mass.
  • the surface cross-linking agent composed of 0.05 part by mass of ethylene glycol diglycidyl ether, 1 part by mass of propylene glycol, 3 parts by mass of water and 1 part by mass of isopropyl alcohol is stirred with respect to 100 parts by mass of the base polymer (1). It was mixed with a mixer. Then, the above mixture was heat-treated at 210 ° C. for 50 minutes to carry out surface cross-linking.
  • the base polymer (1) obtained in Production Example 1 was further pulverized using a roll mill, classified and blended with a sieve having an opening of 150 ⁇ m to obtain a base polymer (2).
  • the obtained base polymer (2) has a mass average particle diameter D (50%) of 330 ⁇ m, a particle ratio of more than 850 ⁇ m is 0.0 mass%, and a particle ratio of 710 ⁇ m or more and less than 850 ⁇ m is 0.0 mass%, 600 ⁇ m or more.
  • the particle ratio of less than 710 ⁇ m is 0.7% by mass
  • the particle ratio of 500 ⁇ m or more and less than 600 ⁇ m is 4.7% by mass
  • the particle ratio of 300 ⁇ m or more and less than 500 ⁇ m is 59.2% by mass
  • the particle ratio of 150 ⁇ m or more and less than 300 ⁇ m is 33.
  • the particle ratio of 1% by mass, 45 ⁇ m or more and less than 150 ⁇ m was 2.2% by mass
  • the particle ratio of less than 45 ⁇ m was 0.1% by mass.
  • the surface cross-linking agent composed of 0.05 part by mass of ethylene glycol diglycidyl ether, 1 part by mass of propylene glycol, 3 parts by mass of water and 1 part by mass of isopropyl alcohol is stirred with respect to 100 parts by mass of the base polymer (2). It was mixed with a mixer. Then, the above mixture was heat-treated at 210 ° C. for 50 minutes to carry out surface cross-linking.
  • the water-absorbent resin (2) obtained in Production Example 2 was further classified by a sieve having an opening of 500 ⁇ m and 150 ⁇ m, and blended to obtain a water-absorbent resin (3).
  • the obtained water-absorbent resin (3) has a mass average particle diameter D (50%) of 324 ⁇ m, a particle ratio of more than 850 ⁇ m is 0.0% by mass, and a particle ratio of 710 ⁇ m or more and less than 850 ⁇ m is 0.0% by mass, 600 ⁇ m.
  • the particle ratio of more than 710 ⁇ m is 0.0% by mass
  • the particle ratio of 500 ⁇ m or more and less than 600 ⁇ m is 0.1% by mass
  • the particle ratio of 300 ⁇ m or more and less than 500 ⁇ m is 70.5% by mass
  • the particle ratio of 150 ⁇ m or more and less than 300 ⁇ m is 29.
  • the particle ratio of 0.4% by mass, 45 ⁇ m or more and less than 150 ⁇ m was 0.0% by mass
  • the particle ratio of less than 45 ⁇ m was 0.0% by mass.
  • the obtained base polymer (4) has a mass average particle diameter D (50%) of 361 ⁇ m, a particle ratio of more than 850 ⁇ m is 0.0 mass%, and a particle ratio of 710 ⁇ m or more and less than 850 ⁇ m is 0.8 mass%, 600 ⁇ m or more.
  • the particle ratio of less than 710 ⁇ m is 12.4% by mass
  • the particle ratio of 500 ⁇ m or more and less than 600 ⁇ m is 14.8% by mass
  • the particle ratio of 300 ⁇ m or more and less than 500 ⁇ m is 34.9% by mass
  • the particle ratio of 150 ⁇ m or more and less than 300 ⁇ m is 29.
  • the particle ratio of 3% by mass, 45 ⁇ m or more and less than 150 ⁇ m was 7.5% by mass, and the particle ratio of less than 45 ⁇ m was 0.3% by mass.
  • the surface cross-linking agent composed of 0.05 part by mass of ethylene glycol diglycidyl ether, 1 part by mass of propylene glycol, 3 parts by mass of water and 1 part by mass of isopropyl alcohol is stirred with respect to 100 parts by mass of the base polymer (4). It was mixed with a mixer. Then, the above mixture was heat-treated at 210 ° C. for 50 minutes to carry out surface cross-linking.
  • a surface cross-linking agent consisting of 0.05 parts by mass of ethylene glycol diglycidyl ether, 3 parts by mass of water and 2 parts by mass of isopropyl alcohol was mixed with 100 parts by mass of the base polymer (1) obtained in Production Example 1 with a stirring mixer. Mixed. Then, the above mixture was heat-treated at 210 ° C. for 50 minutes to carry out surface cross-linking. Then, 3.0 parts by mass of 1.0 mass% diethylenetriamine 5 acetic acid / 3 sodium aqueous solution was added and mixed, and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 ⁇ m to obtain a water-absorbent resin (5).
  • Example 1 Chromalite PCG600M (manufactured by Purolite Co., Ltd., styrene-based synthetic adsorbent, average particle diameter 70 ⁇ m, specific surface area 700 m 2 / g, average pores) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. 0.1 part by mass (in terms of solid content) was added and mixed (diameter 100 ⁇ ), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 ⁇ m to obtain a water-absorbent resin composition (1). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.92% by mass.
  • Example 2 To 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1, 0.5 parts by mass (solid content equivalent) of Chromalite PCG600M was added and mixed, and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 ⁇ m to obtain a water-absorbent resin composition (2).
  • Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.93% by mass.
  • Example 3 To 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1, 1.0 part by mass (solid content equivalent) of Chromalite PCG600M was added and mixed, and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 ⁇ m to obtain a water-absorbent resin composition (3).
  • Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.96% by mass.
  • Example 4 (without binder) A water-absorbent resin composition (4) was obtained in the same manner as in Example 3 except that the water-absorbent resin (5) obtained in Production Example 5 was used.
  • Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • Example 5 (without chelating agent) A water-absorbent resin composition (5) was obtained in the same manner as in Example 3 except that the water-absorbent resin (6) obtained in Production Example 6 was used.
  • Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.95% by mass.
  • Example 6 Purosorb PAD600FM (manufactured by Purolite Co., Ltd., styrene-based synthetic adsorbent, average particle diameter 210 ⁇ m, specific surface area 830 m 2 / g, average pores) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. 0.5 parts by mass (in terms of solid content) was added and mixed (diameter 630 ⁇ ), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 ⁇ m to obtain a water-absorbent resin composition (6). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.94% by mass.
  • Example 7 Purosorb PAD600 (manufactured by Purolite Co., Ltd., styrene-based synthetic adsorbent, average particle diameter 460 ⁇ m, specific surface area 830 m 2 / g, average pores) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. 0.5 parts by mass (in terms of solid content) was added and mixed (diameter 630 ⁇ ), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 ⁇ m to obtain a water-absorbent resin composition (7). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.93% by mass.
  • Example 8 Purosorb PAD610 (manufactured by Purolite Co., Ltd., acrylic synthetic adsorbent, average particle diameter 460 ⁇ m, specific surface area 490 m 2 / g, average pores) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. 0.5 parts by mass (in terms of solid content) was added and mixed (diameter 700 ⁇ ), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 ⁇ m to obtain a water-absorbent resin composition (8). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.96% by mass.
  • Example 9 Diaion 20HP (manufactured by Mitsubishi Chemical Co., Ltd., styrene-based synthetic adsorbent, average particle diameter 390 ⁇ m, specific surface area 590 m 2 / g, average fineness) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. 0.5 parts by mass (solid content equivalent) was added and mixed (hole diameter 290 ⁇ ), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 ⁇ m to obtain a water-absorbent resin composition (9). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.94% by mass.
  • Example 10 Diaion HP2MG (manufactured by Mitsubishi Chemical Co., Ltd., acrylic synthetic adsorbent, average particle diameter 600 ⁇ m, specific surface area 570 m 2 / g, average fineness) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. 0.5 parts by mass (solid content equivalent) was added and mixed (hole diameter 240 ⁇ ), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 ⁇ m to obtain a water-absorbent resin composition (10). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.95% by mass.
  • Example 11 Purosorb PAD300 (manufactured by Purolite Co., Ltd., acrylic synthetic adsorbent, average particle diameter 450 ⁇ m, specific surface area 90 m 2 / g, average pores) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. 0.5 parts by mass (in terms of solid content) was added and mixed (diameter 280 ⁇ ), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 ⁇ m to obtain a water-absorbent resin composition (11). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.93% by mass.
  • Example 12 To 100 parts by mass of the water-absorbent resin (2) obtained in Production Example 2, 0.5 parts by mass (solid content equivalent) of Chromalite PCG600M was added and mixed, and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 ⁇ m to obtain a water-absorbent resin composition (12).
  • Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.96% by mass.
  • Example 13 To 100 parts by mass of the water-absorbent resin (3) obtained in Production Example 3, 0.5 parts by mass (solid content equivalent) of Chromalite PCG600M was added and mixed, and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 ⁇ m to obtain a water-absorbent resin composition (13).
  • Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.94% by mass.
  • Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • the amount of the binder contained in the water-absorbent resin composition was 0.96% by mass.
  • Example 15 A water-absorbent resin composition (15) was obtained in the same manner as in Example 14 except that the water-dispersible emulsion A was changed to 2.5 parts by mass (1 part by mass in terms of solid content).
  • Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • the amount of the binder contained in the water-absorbent resin composition was 0.94% by mass.
  • Example 16 A water-absorbent resin composition (16) was obtained in the same manner as in Example 14 except that the water-dispersible emulsion A was changed to 7.5 parts by mass (3 parts by mass in terms of solid content). Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.96% by mass.
  • Example 17 Epostel S (manufactured by Nippon Catalyst Co., Ltd., triazine group-containing polymer, average particle size 0.2 ⁇ m, ion-exchanged water at 25 ° C.) was added to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. (Solubility is 0% by mass) was added and mixed by 0.3 parts by mass, and then passed through a JIS standard sieve having an opening of 850 ⁇ m to obtain a water-absorbent resin composition (17).
  • Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.93% by mass.
  • Example 18 Example 17 except that Epostal S (manufactured by Nippon Catalyst Co., Ltd., triazine group-containing polymer, average particle size 0.2 ⁇ m, solubility in ion-exchanged water at 25 ° C. is 0% by mass) was changed to 1 part by mass.
  • Epostal S manufactured by Nippon Catalyst Co., Ltd., triazine group-containing polymer, average particle size 0.2 ⁇ m, solubility in ion-exchanged water at 25 ° C. is 0% by mass
  • Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • the amount of the binder contained in the water-absorbent resin composition was 0.94% by mass.
  • Example 19 Example 17 except that Epostal S (manufactured by Nippon Catalyst Co., Ltd., triazine group-containing polymer, average particle size 0.2 ⁇ m, solubility in ion-exchanged water at 25 ° C. is 0% by mass) was changed to 3 parts by mass.
  • Epostal S manufactured by Nippon Catalyst Co., Ltd., triazine group-containing polymer, average particle size 0.2 ⁇ m, solubility in ion-exchanged water at 25 ° C. is 0% by mass
  • Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • the amount of the binder contained in the water-absorbent resin composition was 0.95% by mass.
  • Example 20 1 part by mass (solid content conversion) of poly4-vinylpyridine (made by Strem Chemicals, Inc., pyridine group-containing polymer, 250 ⁇ m or less) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. ) was added and mixed, and then passed through a JIS standard sieve having an opening of 850 ⁇ m to obtain a water-absorbent resin composition (20).
  • Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.96% by mass.
  • Example 21 (without chelating agent) 2.5 parts by mass (1 part by mass in terms of solid content) of the water-dispersible emulsion A is added and mixed with 100 parts by mass of the water-absorbent resin (6) obtained in Production Example 6, and the mixture is further mixed at 60 ° C. Was heated for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 ⁇ m to obtain a water-absorbent resin composition (21).
  • Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.94% by mass.
  • Example 22 (without binder) Epostel S (manufactured by Nippon Catalyst Co., Ltd., triazine group-containing polymer, average particle size 0.2 ⁇ m, ion-exchanged water at 25 ° C.) was added to 100 parts by mass of the water-absorbent resin (5) obtained in Production Example 5. (Solubility is 0% by mass) was added and mixed by 1 part by mass, and then passed through a JIS standard sieve having an opening of 850 ⁇ m to obtain a water-absorbent resin composition (22). Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • Example 23 0.75 parts by mass (0.3 parts by mass in terms of solid content) of water-dispersible emulsion A was added and mixed with 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1, and then Chromalite PCG600M. Was added and mixed by 0.5 parts by mass (in terms of solid content), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 ⁇ m to obtain a water-absorbent resin composition (23).
  • Table 3 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.94% by mass.
  • Example 7 A water-absorbent resin composition (7) for comparison was obtained in the same manner as in Example 14 except that the heating temperature after adding and mixing the water-dispersible emulsion A was changed to 150 ° C.
  • Example 24 25% by mass of water-soluble polymer B (2-isopropenyl-2-oxazoline / ethyl acrylate / methyl methacrylate / methoxypolyethylene glycol) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1.
  • the above-mentioned monomer aqueous solution (7) was poured into a vat-shaped container in an open system to the atmosphere.
  • the butt-shaped container has a bottom surface size of 250 mm ⁇ 250 mm, a top surface size of 640 mm ⁇ 640 mm, a height of 50 mm, a trapezoidal central cross section, and a Teflon (trademark) sheet attached to the inner surface. Met.
  • the vat-shaped container was placed on a hot plate heated to 100 ° C. and preheated. After the above-mentioned monomer aqueous solution (7) was poured into the above-mentioned vat-shaped container, the polymerization reaction started about 5 seconds later.
  • the polymerization reaction proceeded while the monomer aqueous solution (7) expanded and foamed upward while generating water vapor, and then the water content was obtained to a size slightly larger than the bottom surface of the bat-shaped container.
  • the gel (7) shrank and finished.
  • the polymerization reaction (expansion and contraction) was completed within about 1 minute, but the state of the hydrogel (7) was maintained in the bat-shaped container for 2 minutes thereafter.
  • the polymerization reaction gave a hydrogel (7) containing bubbles.
  • the water-containing gel (7) obtained by the above polymerization reaction was divided into 16 equal parts, and then a tabletop meat chopper (MEAT-CHOPPER TYPE: 12VR-400KSOX, manufactured by Iizuka Kogyo Co., Ltd.) having a porous plate was used to contain water. Simultaneously with the addition of the gel, gel pulverization was performed while adding 25 parts by mass of 0.2% by mass sodium hydrogen sulfite aqueous solution at 25 ° C. to the water-containing gel with respect to 100 parts by mass (265 g) of the solid content of the water-containing gel. A hydrous gel (7) was obtained.
  • the particulate hydrogel (7) was spread on a wire mesh having a mesh size of 300 ⁇ m (50 mesh) and placed in a static dryer (ventilation flow batch dryer 71-S6 type (Satake Chemical Machinery Co., Ltd.).
  • the dry polymer (7) in the form of particles was obtained by drying at 180 ° C. for 30 minutes using (manufactured by).
  • the dried polymer (7) is put into a roll mill (WML type roll crusher, manufactured by Inoguchi Giken Co., Ltd.) and pulverized, and then passed through the sieve using a JIS standard sieve having an opening of 150 ⁇ m. By classifying the particles, a fine powdery water-absorbent resin (7) was obtained.
  • WML type roll crusher manufactured by Inoguchi Giken Co., Ltd.
  • the dried polymer (8) was put into a roll mill (WML type roll crusher, manufactured by Inoguchi Giken Co., Ltd.) and crushed, and then using two types of JIS standard sieves with a mesh size of 850 ⁇ m and 150 ⁇ m. By classifying with a low-tap type sieve classifier, an amorphous crushed water-absorbent resin (8) was obtained.
  • WML type roll crusher manufactured by Inoguchi Giken Co., Ltd.
  • ethylene glycol diglycidyl ether (trade name: Denacol EX-810, manufactured by Nagase ChemteX, 0.025 parts by mass), propylene glycol (1.35 parts by mass), deionized water (3.15 parts by mass).
  • the surface cross-linking agent solution (8) composed of the above is added to the amorphous crushed water-absorbent resin (8) (100 parts by mass) and mixed with a spatula until uniform to obtain a humidified mixture (8). rice field. Subsequently, the humidified mixture (8) was uniformly placed in a stainless steel container and heat-treated at 180 ° C. for 40 minutes to obtain a surface-crosslinked water-absorbent resin (8).
  • a granulated gel is produced by using 2.64 g of a 20% by mass ethylenediamine tetraacetate disodium aqueous solution added by polymerization and using deionized water as a sodium bisulfite aqueous solution added by gel grinding.
  • the water-absorbent resin (10) was obtained in the same manner as in Production Example 8 except that the granulated gel (9) obtained in Example 9 was used and the concentration of the sodium bisulfite aqueous solution added after surface cross-linking was 5.0% by mass. ) was obtained.
  • Granulation gel (11) was obtained in the same manner as in Production Example 9 except that the chelating agent added by polymerization was a 20% by mass diethylenetriamine-5 trisodium acetate aqueous solution.
  • the chelating agent added by polymerization is a 20 mass% diethylenetriamine 5-sodium acetate aqueous solution
  • the granulation gel combined with the particulate water-containing gel is the granulation gel (11) obtained in Production Example 11, and surface cross-linking is performed.
  • a water-absorbent resin (12) was obtained in the same manner as in Production Example 10 except that the concentration of the sodium bisulfite aqueous solution to be added later was 7.5% by mass.
  • a granulated gel (21) was obtained in the same manner as in Production Example 17 except that the chelating agent added by polymerization was 0.66 g of a 20 mass% ethylenediaminetetramethylenephosphonic acid 5 sodium aqueous solution.
  • a water-absorbent resin (27) was obtained in the same manner as in Production Example 8 except that the dry polymer (8) was pulverized twice with a roll mill in Production Example 8.
  • Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • Example 26 In Example 25, the water-absorbent resin composition (26) was obtained in the same manner as in Example 25 except that the water-absorbent resin (8) was changed to the water-absorbent resin (10) obtained in Production Example 10. .. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • Example 27 the water-absorbent resin composition (27) was obtained in the same manner as in Example 25 except that the water-absorbent resin (8) was changed to the water-absorbent resin (12) obtained in Production Example 12. .. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • Example 28 In Example 25, the water-absorbent resin composition (28) was the same as in Example 25 except that the water-absorbent resin (8) was changed to 100 parts by mass of the water-absorbent resin (14) obtained in Production Example 14.
  • Got Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • Example 29 In Example 25, the water-absorbent resin composition (29) was obtained in the same manner as in Example 25 except that the water-absorbent resin (8) was changed to the water-absorbent resin (16) obtained in Production Example 16. .. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • Example 30 25% by mass of water-soluble polymer B (2-isopropenyl-2-oxazoline / ethyl acrylate / methyl methacrylate / methoxypolyethylene glycol) with respect to 100 parts by mass of the water-absorbent resin (18) obtained in Production Example 18.
  • Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • Example 31 the water-absorbent resin composition (31) was obtained in the same manner as in Example 30 except that the water-absorbent resin (18) was changed to the water-absorbent resin (20) obtained in Production Example 20. .. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • Example 32 In Example 30, the water-absorbent resin composition (32) was obtained in the same manner as in Example 30 except that the water-absorbent resin (18) was changed to the water-absorbent resin (22) obtained in Production Example 22. rice field. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • Example 33 the water-absorbent resin composition (33) was obtained in the same manner as in Example 30 except that the water-absorbent resin (18) was changed to the water-absorbent resin (24) obtained in Production Example 24. .. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • Example 34 the water-absorbent resin composition (34) was obtained in the same manner as in Example 30 except that the water-absorbent resin (18) was changed to the water-absorbent resin (26) obtained in Production Example 26. .. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • Example 35 the water-absorbent resin composition (35) was obtained in the same manner as in Example 30 except that the water-absorbent resin (18) was changed to the water-absorbent resin (27) obtained in Production Example 27. .. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • Example 36 the water-absorbent resin composition (36) was obtained in the same manner as in Example 14 except that the water-absorbent resin (1) was changed to the water-absorbent resin (27) obtained in Production Example 27. .. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • Example 30 the comparative water-absorbent resin composition (18) was prepared in the same manner as in Example 30 except that the water-absorbent resin (18) was changed to the water-absorbent resin (28) obtained in Production Example 28. Obtained.
  • Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • Example 14 the comparative water-absorbent resin composition (19) was prepared in the same manner as in Example 14 except that the water-absorbent resin (1) was changed to the water-absorbent resin (28) obtained in Production Example 28. Obtained.
  • Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
  • a water-absorbent resin, a hydrophobic porous polymer adsorbent, and a resin having a nitrogen-containing heterocycle are contained at least one component, and the span value is equal to or less than a specific value. It turns out that the composition of and is important.

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Abstract

[Problem] The purpose of the present invention is to provide a novel water-absorbable resin composition having superior deodorizing ability than the conventional water-absorbable resin compositions. [Solution] One embodiment for achieving the purpose is a water-absorbable resin composition which comprises a water-absorbable resin and at least one of a hydrophobic porous polymer adsorbent and a resin having a nitrogenated heterocyclic ring and which has a span value of 1.10 or less wherein the span value is expressed by formula 1. D(90%) represents a particle diameter (unit: μm) such that the cumulative amount from the minimum diameter becomes 90% in a cumulative particle diameter distribution of particles; D(10%) represents a particle diameter (unit: μm) such that the cumulative amount from the minimum diameter becomes 10% in a cumulative particle diameter distribution of particles; and D(50%) represents a particle diameter (unit: μm) such that the cumulative amount from the minimum diameter becomes 50% in a cumulative particle diameter distribution of particles; wherein each of D(90%), D(10%) and D(50%) is a mass-based cumulative value.

Description

吸水性樹脂組成物Water-absorbent resin composition
　本発明は、吸水性樹脂組成物に関する。 The present invention relates to a water-absorbent resin composition.
　吸水性樹脂は、尿や血液などの体液等を吸収させることを目的として、紙おむつ、生理用ナプキン、失禁パッド等の衛生材料に広く用いられており、これらの衛生材料の主要な構成材料になっている。近年、社会の高齢化に伴う大人用紙おむつの需要増大に伴い、吸水性樹脂に対して消臭性能の付与、特に尿に起因する悪臭に対する優れた消臭性能の付与に関する要求が高まっている。 Water-absorbent resins are widely used in sanitary materials such as disposable diapers, menstrual napkins, and incontinence pads for the purpose of absorbing body fluids such as urine and blood, and are the main constituent materials of these sanitary materials. ing. In recent years, with the increasing demand for adult disposable diapers due to the aging of society, there is an increasing demand for imparting deodorant performance to water-absorbent resins, particularly excellent deodorant performance for malodor caused by urine.
　吸水性樹脂に消臭機能を付与する試みとしては、様々な方法が提案されている。例えば、ペルオキソ化合物や、重金属（ゼオライト粉末）、多孔性ポリマーを吸収体に混合する方法が知られている（それぞれ、特許文献１、２、３）。また、尿または血液などの体液から発生する可能性のある悪臭を制御するために、吸水性樹脂と、疎水性多孔質ポリマーを含む組成物が提案されている（特許文献４）。 Various methods have been proposed as an attempt to impart a deodorizing function to the water-absorbent resin. For example, a method of mixing a peroxo compound, a heavy metal (zeolite powder), or a porous polymer with an absorber is known (Patent Documents 1, 2, and 3, respectively). Further, in order to control the malodor that may be generated from body fluids such as urine or blood, a composition containing a water-absorbent resin and a hydrophobic porous polymer has been proposed (Patent Document 4).
特開２０１５－１６８８２４号公報Japanese Unexamined Patent Publication No. 2015-168824 特表２００１－５０５２３７号公報Japanese Patent Publication No. 2001-505237 特開２０１７－１４０３３２号公報Japanese Unexamined Patent Publication No. 2017-140332 国際公開第２００５／１２０５９４号International Publication No. 2005/120594
　吸水性樹脂に対する優れた消臭性能の付与に関する要求は、近年、より一層求められており特に尿に起因する悪臭に対し、より優れた消臭化技術が必要になっている。 In recent years, there has been an even greater demand for imparting excellent deodorizing performance to water-absorbent resins, and there is a need for better deodorizing technology, especially for bad odors caused by urine.
　そこで、本発明は従来よりも優れた消臭能を有する、新規な吸水性樹脂組成物を目的とする。 Therefore, the present invention aims at a novel water-absorbent resin composition having a deodorizing ability superior to that of the conventional one.
　上記目的を達成するための一形態は、吸水性樹脂と、疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分を含み、下記式１で表されるスパン値が、１．１０以下である、吸水性樹脂組成物である。 One form for achieving the above object comprises at least one component of a water-absorbent resin, a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle, and the span value represented by the following formula 1 is a span value. It is a water-absorbent resin composition of 1.10 or less.
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000003
　上記式（１）において、
Ｄ（９０％）は、粒子径の累積粒径分布において、最小径からの累積が９０％となる粒子径（単位：μｍ）、
　Ｄ（１０％）は、粒子径の累積粒径分布において、最小径からの累積が１０％となる粒子径（単位：μｍ）、
　Ｄ（５０％）は、粒子径の累積粒径分布において、最小径からの累積が５０％となる粒子径（単位：μｍ）であり、ここで、Ｄ（９０％）、Ｄ（１０％）、Ｄ（５０％）は、質量基準で累積した値である。 In the above formula (1)
D (90%) is a particle size (unit: μm) in which the cumulative particle size distribution from the minimum diameter is 90% in the cumulative particle size distribution.
D (10%) is a particle size (unit: μm) in which the cumulative particle size distribution from the minimum diameter is 10% in the cumulative particle size distribution.
D (50%) is a particle size (unit: μm) in which the cumulative particle size distribution from the minimum diameter is 50% in the cumulative particle size distribution, where D (90%) and D (10%). , D (50%) are cumulative values on a mass basis.
　本願によれば、従来の消臭剤を使った吸水性樹脂組成物に対し、より優れた消臭能を有する、新規な吸水性樹脂組成物を提供することができる。 According to the present application, it is possible to provide a novel water-absorbent resin composition having a more excellent deodorizing ability than a conventional water-absorbent resin composition using a deodorant.
　以下、本発明を最良の形態を示しながら説明する。本明細書の全体にわたり、単数形の表現は、特に言及しない限り、その複数形の概念をも含むことが理解されるべきである。従って、単数形の冠詞（例えば、英語の場合は「ａ」、「ａｎ」、「ｔｈｅ」等）は、特に言及しない限り、その複数形の概念をも含むことが理解されるべきである。また、本明細書において使用される用語は、特に言及しない限り、当該分野で通常用いられる意味で用いられることが理解されるべきである。したがって、他に定義されない限り、本明細書中で使用される全ての専門用語及び科学技術用語は、本発明の属する分野の当業者によって一般的に理解されるのと同じ意味を有する。矛盾する場合、本明細書（定義を含めて）が優先する。本発明は、下記の実施形態に限定されるものではなく、特許請求の範囲内で種々改変することができる。また、本明細書に開示されている全ての下限値上限値の値は、全ての組合せが開示されていると理解されなければならない。つまり、補正の根拠となりうると理解されなければならない。また、全ての実施形態の組み合わせが本願では開示されていると理解されなければならない。つまり、補正の根拠となりうると理解されなければならない。 Hereinafter, the present invention will be described while showing the best form. Throughout the specification, it should be understood that the singular representation also includes its plural concept, unless otherwise noted. Therefore, it should be understood that singular articles (eg, "a", "an", "the", etc. in English) also include the plural concept unless otherwise noted. It should also be understood that the terms used herein are used in the meaning commonly used in the art unless otherwise noted. Accordingly, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, this specification (including definitions) takes precedence. The present invention is not limited to the following embodiments, and various modifications can be made within the scope of the claims. It should also be understood that all combinations of all lower and upper limits disclosed herein are disclosed. In other words, it must be understood that it can be the basis for amendments. It should also be understood that all combinations of embodiments are disclosed herein. In other words, it must be understood that it can be the basis for amendments.
　上記目的を達成するための一態様は、吸水性樹脂と、疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分とを含み、下記式１で表されるスパン値が、１．１０以下である、吸水性樹脂組成物である。 One aspect for achieving the above object includes a water-absorbent resin and at least one component of a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle, and the span value represented by the following formula 1 is , 1.10 or less, is a water-absorbent resin composition.
Figure JPOXMLDOC01-appb-M000004
Figure JPOXMLDOC01-appb-M000004
　上記式（１）において、
Ｄ（９０％）は、粒子径の累積粒径分布において、最小径からの累積が９０％となる粒子径（単位：μｍ）、
　Ｄ（１０％）は、粒子径の累積粒径分布において、最小径からの累積が１０％となる粒子径（単位：μｍ）、
　Ｄ（５０％）は、粒子径の累積粒径分布において、最小径からの累積が５０％となる粒子径（単位：μｍ）であり、ここで、Ｄ（９０％）、Ｄ（１０％）、Ｄ（５０％）は、質量基準で累積した値である。 In the above formula (1)
D (90%) is a particle size (unit: μm) in which the cumulative particle size distribution from the minimum diameter is 90% in the cumulative particle size distribution.
D (10%) is a particle size (unit: μm) in which the cumulative particle size distribution from the minimum diameter is 10% in the cumulative particle size distribution.
D (50%) is a particle size (unit: μm) in which the cumulative particle size distribution from the minimum diameter is 50% in the cumulative particle size distribution, where D (90%) and D (10%). , D (50%) are cumulative values on a mass basis.
　かかる構成によって、従来の消臭剤を使った吸水性樹脂組成物に対し、より優れた消臭能を有する、新規な吸水性樹脂組成物を提供することができる。 With such a configuration, it is possible to provide a novel water-absorbent resin composition having a more excellent deodorizing ability than the conventional water-absorbent resin composition using a deodorant.
　［１］用語の定義
　［１－１］　吸水性樹脂、ベースポリマー、吸水性樹脂組成物
　本発明における「吸水性樹脂」とは、水膨潤性水不溶性の高分子ゲル化剤を意味し、一般的に粉末状である。また、「水膨潤性」とは、後述するＥＤＡＮＡ　ＷＳＰ２４１．３（１０）で規定される無加圧下吸収倍率（ＣＲＣ）が５ｇ／ｇ以上であることを、「水不溶性」とは、ＷＳＰ２７０．３（１０）で規定される可溶分（Ｅｘｔ）が５０質量％以下であることを、それぞれ意味する。 [1] Definition of terms [1-1] Water-absorbent resin, base polymer, water-absorbent resin composition The "water-absorbent resin" in the present invention means a water-swellable water-insoluble polymer gelling agent and is generally used. It is in the form of powder. Further, "water swellability" means that the absorption ratio under no pressure (CRC) defined in EDANA WSP241.3 (10) described later is 5 g / g or more, and "water insoluble" means WSP270. It means that the soluble content (Ext) defined in 3 (10) is 50% by mass or less, respectively.
　前記「吸水性樹脂」は、好ましくはカルボキシル基を有する不飽和単量体を架橋重合させてなる親水性の架橋重合体（いわゆる内部架橋重合体）であるが、その全量（１００質量％）が架橋重合体である必要はない。 The "water-absorbent resin" is preferably a hydrophilic crosslinked polymer (so-called internal crosslinked polymer) formed by cross-linking and polymerizing an unsaturated monomer having a carboxyl group, but the total amount (100% by mass) thereof is It does not have to be a crosslinked polymer.
　また、一般的には「吸水性樹脂」は、「内部のみが架橋された重合体（つまり、内部と表面の架橋密度が実質的に同じである重合体）」または「内部と表面とが架橋された重合体（つまり、表面の架橋密度が内部の架橋密度に対して相対的に高い重合体）」を指す場合があるが、本明細書では、用語を使い分けることとし、内部のみが架橋された重合体を「ベースポリマー」と表記し、内部と表面とが架橋された重合体を「吸水性樹脂」と表記する。 In general, a "water-absorbent resin" is a "polymer in which only the inside is crosslinked (that is, a polymer in which the crosslink density between the inside and the surface is substantially the same)" or "a polymer in which the inside and the surface are crosslinked. In some cases, it refers to a polymer that has been cross-linked (that is, a polymer whose surface cross-linking density is relatively high relative to the internal cross-linking density). The polymer is referred to as "base polymer", and the polymer in which the inside and the surface are crosslinked is referred to as "water-absorbent resin".
　本発明における「吸水性樹脂組成物」とは、吸水性樹脂と、疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分とを含み、必要に応じてその他の成分を含む組成物を意味するが、平たく言えば、最終製品として出荷可能な状態にある吸水性樹脂のことを意味する。従って、前記「吸水性樹脂」に疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分や、必要に応じその他添加剤を含有させると「吸水性樹脂組成物」となる。なお、本明細書中、吸水性樹脂組成物を単に吸水剤と称する場合がある。 The "water-absorbent resin composition" in the present invention contains at least one component of a water-absorbent resin, a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle, and if necessary, other components. It means a composition containing, but in a nutshell, it means a water-absorbent resin that is ready to be shipped as a final product. Therefore, if the "water-absorbent resin" contains at least one component of a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle, and if necessary, other additives, the "water-absorbent resin composition" is obtained. .. In the present specification, the water-absorbent resin composition may be simply referred to as a water-absorbent agent.
　［１－２］　「ＥＤＡＮＡ」及び「ＷＳＰ」
　「ＥＤＡＮＡ」は、欧州不織布工業会（Ｅｕｒｏｐｅａｎ　Ｄｉｓｐｏｓａｂｌｅｓ　ａｎｄ　Ｎｏｎｗｏｖｅｎｓ　Ａｓｓｏｃｉａｔｉｏｎｓ）の略称である。また「ＷＳＰ」は、Ｗｏｒｌｄｗｉｄｅ　Ｓｔｒａｔｅｇｉｃ　Ｐａｒｔｎｅｒｓの略称であり、ＥＤＡＮＡが提供する、吸水性樹脂の世界標準の測定法を示すものである。本発明では、特に断りのない限り、ＷＳＰ原本（２０１０年改定／公知文献）に準拠して、吸水性樹脂の物性を測定する。 [1-2] "EDANA" and "WSP"
"EDANA" is an abbreviation for European Disposables and Nonwovens Associations. Further, "WSP" is an abbreviation for Worldwise Strategic Partners, and indicates a world standard measurement method for water-absorbent resin provided by EDANA. In the present invention, unless otherwise specified, the physical properties of the water-absorbent resin are measured in accordance with the original WSP (revised in 2010 / publicly known literature).
　［１－２－１］　「ＣＲＣ」（ＷＳＰ２４１．３（１０））
　無加圧下吸収倍率を意味する「ＣＲＣ」は、Ｃｅｎｔｒｉｆｕｇｅ　Ｒｅｔｅｎｔｉｏｎ　Ｃａｐａｃｉｔｙの略称であり、吸水剤又は吸水性樹脂の無加圧下での吸収倍率を意味する。具体的には、吸水剤又は吸水性樹脂０．２ｇを不織布製の袋に入れた後、大過剰の０．９質量％塩化ナトリウム水溶液中に３０分間浸漬して吸水性樹脂を自由膨潤させ、その後、遠心分離機（２５０Ｇ）を用いて３分間脱水した後の吸収倍率（単位；ｇ／ｇ）のことである。 [1-2-1] "CRC" (WSP241.3 (10))
"CRC", which means the absorption ratio under no pressure, is an abbreviation for Centrifuge Retention Capacity, and means the absorption ratio of a water-absorbing agent or a water-absorbent resin under no pressure. Specifically, 0.2 g of a water-absorbing agent or a water-absorbent resin is placed in a bag made of a non-woven fabric, and then immersed in a large excess of 0.9% by mass sodium chloride aqueous solution for 30 minutes to freely swell the water-absorbent resin. Then, it is the absorption ratio (unit: g / g) after dehydration for 3 minutes using a centrifuge (250 G).
　［１－２－２］　「ＡＡＰ」（ＷＳＰ２４２．３（１０））
　「ＡＡＰ」は、Ａｂｓｏｒｐｔｉｏｎ　Ａｇａｉｎｓｔ　Ｐｒｅｓｓｕｒｅの略称であり、吸水剤又は吸水性樹脂の加圧下吸収倍率を意味する。具体的には、吸水剤又は吸水性樹脂０．９ｇを大過剰の０．９質量％塩化ナトリウム水溶液に対して、１時間、４．８３ｋＰａ（０．７ｐｓｉ）荷重下で膨潤させた後の吸収倍率（単位；ｇ／ｇ）のことをいう。 [1-2-2] "AAP" (WSP242.3 (10))
"AAP" is an abbreviation for Absorption Against Pressure, and means the absorption ratio under pressure of a water-absorbing agent or a water-absorbent resin. Specifically, absorption after swelling 0.9 g of a water-absorbing agent or a water-absorbent resin with a large excess of 0.9 mass% sodium chloride aqueous solution for 1 hour under a load of 4.83 kPa (0.7 psi). Magnification (unit: g / g).
　［２］吸水性樹脂組成物およびその製造方法
　本発明の実施形態における吸水性樹脂組成物は、吸水性樹脂と、疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分とを含み、式１で表されるスパン値が、１．１０以下である。 [2] Water-absorbent resin composition and method for producing the same The water-absorbent resin composition according to the embodiment of the present invention contains at least one of a water-absorbent resin, a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle. And, the span value represented by the formula 1 is 1.10 or less.
　吸水性樹脂の例としては、ポリアクリル酸（塩）系吸水性樹脂、ポリスルホン酸（塩）系吸水性樹脂、無水マレイン酸（塩）系吸水性樹脂、ポリアクリルアミド系吸水性樹脂、ポリビニルアルコール系吸水性樹脂、ポリエチレンオキシド系吸水性樹脂、ポリアスパラギン酸（塩）系吸水性樹脂、ポリグルタミン酸（塩）系吸水性樹脂、ポリアルギン酸（塩）系吸水性樹脂、デンプン系吸水性樹脂、セルロース系吸水性樹脂が挙げられる。このうち、好ましくは、ポリアクリル酸（塩）系吸水性樹脂として使用される。 Examples of water-absorbent resins include polyacrylic acid (salt) -based water-absorbent resin, polysulfonic acid (salt) -based water-absorbent resin, maleic anhydride (salt) -based water-absorbent resin, polyacrylamide-based water-absorbent resin, and polyvinyl alcohol-based resin. Water-absorbent resin, polyethylene oxide-based water-absorbent resin, polyaspartic acid (salt) -based water-absorbent resin, polyglutamic acid (salt) -based water-absorbent resin, polyarginic acid (salt) -based water-absorbent resin, starch-based water-absorbent resin, cellulose-based Examples include water-absorbent resins. Of these, it is preferably used as a polyacrylic acid (salt) -based water-absorbent resin.
　本発明の実施形態における「ポリアクリル酸（塩）系吸水性樹脂」とは、アクリル酸および／またはその塩（以下、「アクリル酸（塩）」と表記する）を原料とする吸水性樹脂を意味する。つまり、ポリアクリル酸（塩）系吸水性樹脂は、重合体中にアクリル酸（塩）由来の構造単位を有し、任意成分としてグラフト成分を有する、吸水性樹脂である。 The "polyacrylic acid (salt) -based water-absorbent resin" in the embodiment of the present invention is a water-absorbent resin made from acrylic acid and / or a salt thereof (hereinafter referred to as "acrylic acid (salt)"). means. That is, the polyacrylic acid (salt) -based water-absorbent resin is a water-absorbent resin having a structural unit derived from acrylic acid (salt) in the polymer and having a graft component as an optional component.
　具体的には、ポリアクリル酸（塩）系吸水性樹脂は、重合反応に関与する単量体全体（但し、内部架橋剤は除く）に対して、好ましくは５０モル％～１００モル％、より好ましくは７０モル％～１００モル％、さらに好ましくは９０モル％～１００モル％、特に好ましくは実質１００モル％のアクリル酸（塩）を含む、吸水性樹脂である。 Specifically, the polyacrylic acid (salt) -based water-absorbent resin is preferably 50 mol% to 100 mol%, more, with respect to the entire monomer involved in the polymerization reaction (however, excluding the internal cross-linking agent). A water-absorbent resin preferably containing 70 mol% to 100 mol%, more preferably 90 mol% to 100 mol%, and particularly preferably substantially 100 mol% of acrylic acid (salt).
　続いて、吸水性樹脂組成物の好ましい製造方法に関して詳細に説明する。無論、下記の製造方法に限定されない。 Subsequently, a preferred method for producing the water-absorbent resin composition will be described in detail. Of course, it is not limited to the following manufacturing method.
　［２－１］　単量体水溶液の調製工程
　本工程は、アクリル酸（塩）を主成分として含む単量体および少なくとも１種類の内部架橋剤を含む単量体水溶液を調製する工程である。前記「主成分」とは、重合反応に供される単量体全体（但し、内部架橋剤は除く）に対して、アクリル酸（塩）の使用量（含有量）が、通常、５０モル％以上、好ましくは７０モル％以上、より好ましくは９０モル％以上であること（上限は１００モル％）を指す。なお、最終製品として得られる吸水剤の吸水性能に影響しない範囲内で、単量体のスラリー液を使用することもできるが、本明細書では便宜上、単量体水溶液について説明する。 [2-1] Preparation Step of Monomer Aqueous Solution This step is a step of preparing a monomer aqueous solution containing a monomer containing acrylic acid (salt) as a main component and at least one kind of internal cross-linking agent. The "main component" means that the amount (content) of acrylic acid (salt) used is usually 50 mol% with respect to the entire monomer (however, excluding the internal cross-linking agent) subjected to the polymerization reaction. As mentioned above, it means that it is preferably 70 mol% or more, more preferably 90 mol% or more (upper limit is 100 mol%). Although a monomer slurry solution can be used as long as it does not affect the water absorption performance of the water absorbing agent obtained as a final product, the monomer aqueous solution will be described here for convenience.
　（アクリル酸（塩））
　本発明の実施形態では、吸水剤の物性および生産性の観点から、公知のアクリル酸（塩）を単量体（重合性単量体とも称される）として用いることが好ましい。公知のアクリル酸には、重合禁止剤や不純物等の成分が微量含まれている。当該重合禁止剤として、好ましくはメトキシフェノール類、より好ましくはｐ－メトキシフェノール類が使用される。重合禁止剤のアクリル酸中での含有量（濃度）は、アクリル酸の重合性や吸水剤の色調等の観点から、好ましくは２００ｐｐｍ（質量基準）以下、より好ましくは１０ｐｐｍ（質量基準）～１６０ｐｐｍ（質量基準）、さらに好ましくは２０ｐｐｍ（質量基準）～１００ｐｐｍ（質量基準）である。当該不純物として、酢酸やプロピオン酸、フルフラール等の有機化合物に加えて、米国特許出願公開第２００８／０１６１５１２号に記載された各化合物が本発明の実施形態で用いるアクリル酸にも含まれている。 (Acrylic acid (salt))
In the embodiment of the present invention, it is preferable to use a known acrylic acid (salt) as a monomer (also referred to as a polymerizable monomer) from the viewpoint of physical properties and productivity of the water absorbent. Known acrylic acids contain trace amounts of components such as polymerization inhibitors and impurities. As the polymerization inhibitor, methoxyphenols are preferably used, and p-methoxyphenols are more preferably used. The content (concentration) of the polymerization inhibitor in acrylic acid is preferably 200 ppm (mass standard) or less, more preferably 10 ppm (mass standard) to 160 ppm, from the viewpoint of the polymerizable property of acrylic acid and the color tone of the water absorbent. (Mass basis), more preferably 20 ppm (mass basis) to 100 ppm (mass basis). As the impurities, in addition to organic compounds such as acetic acid, propionic acid, and furfural, each compound described in US Patent Application Publication No. 2008/0161512 is also contained in acrylic acid used in the embodiment of the present invention.
　また、アクリル酸塩として、上述したアクリル酸を下記塩基性化合物で中和した塩が挙げられる。当該アクリル酸塩は、市販のアクリル酸塩（例えば、アクリル酸ナトリウム）でもよく、アクリル酸を中和して得られる塩でもよい。 Further, examples of the acrylate include a salt obtained by neutralizing the above-mentioned acrylic acid with the following basic compound. The acrylate may be a commercially available acrylate (for example, sodium acrylate) or a salt obtained by neutralizing acrylic acid.
　（塩基性化合物）
　本発明の実施形態における塩基性化合物は、塩基性を示す化合物を指し、具体的には水酸化ナトリウム等が該当する。なお、市販の水酸化ナトリウムには、亜鉛、鉛、鉄等の重金属がｐｐｍ（質量基準）オーダーで含まれており、厳密には組成物と表現することもできるが、本発明では、このような組成物に関しても塩基性化合物の範疇に含めることとして扱う。 (Basic compound)
The basic compound in the embodiment of the present invention refers to a compound exhibiting basicity, and specifically, sodium hydroxide or the like is applicable. Commercially available sodium hydroxide contains heavy metals such as zinc, lead, and iron on the order of ppm (mass basis), and can be expressed as a composition in a strict sense. Compositions are also treated as being included in the category of basic compounds.
　前記塩基性化合物の具体例として、アルカリ金属の炭酸塩や炭酸水素塩、アルカリ金属の水酸化物、アンモニア、有機アミン等が挙げられる。中でも、吸水剤の吸水性能の観点から、強塩基性の化合物が選択される。従って、ナトリウム、カリウム、リチウム等のアルカリ金属の水酸化物が好ましく、水酸化ナトリウムがより好ましい。なお、当該塩基性化合物は、取り扱い性の観点から、水溶液とされることが好ましい。 Specific examples of the basic compound include alkali metal carbonates and bicarbonates, alkali metal hydroxides, ammonia, organic amines and the like. Among them, a strongly basic compound is selected from the viewpoint of the water absorption performance of the water absorbing agent. Therefore, hydroxides of alkali metals such as sodium, potassium and lithium are preferable, and sodium hydroxide is more preferable. The basic compound is preferably an aqueous solution from the viewpoint of handleability.
　（中和）
　前記アクリル酸塩として、アクリル酸を中和して得られる塩を使用する場合には、その中和を行う時期は、特に限定されず、重合前、重合中、重合後の何れでもよく、複数の時期または箇所で中和を行うこともできる。また、吸水剤の生産効率の観点から、連続式で中和することが好ましい。 (Neutralization)
When a salt obtained by neutralizing acrylic acid is used as the acrylic acid salt, the timing of the neutralization is not particularly limited, and may be any of pre-polymerization, during-polymerization, and post-polymerization. Neutralization can also be performed at the time or place of. Further, from the viewpoint of the production efficiency of the water absorbing agent, it is preferable to neutralize in a continuous manner.
　本発明においてアクリル酸（塩）を用いる場合、その中和率は、単量体の酸基に対して、好ましくは１０モル％～９０モル％、より好ましくは４０モル％～８５モル％、さらに好ましくは５０モル％～８０モル％、特に好ましくは６０モル％～７８モル％である。当該中和率の範囲とすることで、吸水剤の吸水性能の低下を抑制することができる。 When acrylic acid (salt) is used in the present invention, the neutralization rate thereof is preferably 10 mol% to 90 mol%, more preferably 40 mol% to 85 mol%, and further, with respect to the acid group of the monomer. It is preferably 50 mol% to 80 mol%, and particularly preferably 60 mol% to 78 mol%. By setting the neutralization rate within the range, it is possible to suppress the deterioration of the water absorption performance of the water absorbing agent.
　なお、前記中和率の範囲は、上述した重合前、重合中、重合後の何れの中和においても適用される。また、最終製品としての吸水剤に関しても同様に適用される。 The range of the neutralization rate is applied to any of the above-mentioned neutralization before, during, and after the polymerization. The same applies to the water absorbing agent as a final product.
　（他の単量体）
　本発明において、上述したアクリル酸（塩）以外の単量体（以下、「他の単量体」と表記する）を、必要に応じてアクリル酸（塩）と併用することができる。 (Other monomers)
In the present invention, a monomer other than the above-mentioned acrylic acid (salt) (hereinafter, referred to as “other monomer”) can be used in combination with acrylic acid (salt), if necessary.
　前記他の単量体としては、具体的には、（無水）マレイン酸、イタコン酸、ケイ皮酸、ビニルスルホン酸、アリルトルエンスルホン酸、ビニルトルエンスルホン酸、スチレンスルホン酸、２－（メタ）アクリルアミド－２－メチルプロパンスルホン酸、２－（メタ）アクリロイルエタンスルホン酸、２－（メタ）アクリロイルプロパンスルホン酸、２－ヒドロキシエチル（メタ）アクリロイルフォスフェート等のアニオン性不飽和単量体およびその塩；メルカプタン基含有不飽和単量体；フェノール性水酸基含有不飽和単量体；（メタ）アクリルアミド、Ｎ－エチル（メタ）アクリルアミド、Ｎ，Ｎ－ジメチル（メタ）アクリルアミド等のアミド基含有不飽和単量体；Ｎ，Ｎ－ジメチルアミノエチル（メタ）アクリレート、Ｎ，Ｎ－ジメチルアミノプロピル（メタ）アクリレート、Ｎ，Ｎ－ジメチルアミノプロピル（メタ）アクリルアミド等のアミノ基含有不飽和単量体が挙げられる。また、当該他の単量体には、水溶性または疎水性の不飽和単量体が含まれる。当該他の単量体を用いる場合には、その使用量は単量体全体（但し、内部架橋剤は除く）に対して、好ましくは３０モル％以下、より好ましくは１０モル％以下、さらに好ましくは５モル％以下である。 Specific examples of the other monomers include (anhydrous) maleic acid, itaconic acid, acrylate, vinyl sulfonic acid, allyltoluenesulfonic acid, vinyltoluenesulfonic acid, styrenesulfonic acid, and 2- (meth). Anionic unsaturated monomers such as acrylamide-2-methylpropanesulfonic acid, 2- (meth) acryloylethanesulfonic acid, 2- (meth) acryloylpropanesulfonic acid, 2-hydroxyethyl (meth) acryloyl phosphate and the like. Salt; mercaptan group-containing unsaturated monomer; phenolic hydroxyl group-containing unsaturated monomer; amide group-containing unsaturated such as (meth) acrylamide, N-ethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, etc. Monomer; Amino group-containing unsaturated monomer such as N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylamide Can be mentioned. In addition, the other monomer includes a water-soluble or hydrophobic unsaturated monomer. When the other monomer is used, the amount used is preferably 30 mol% or less, more preferably 10 mol% or less, still more preferably 10 mol% or less, based on the entire monomer (excluding the internal cross-linking agent). Is 5 mol% or less.
　（内部架橋剤）
　好ましい製造方法においては、内部架橋剤が使用される。当該内部架橋剤としては、具体的には、例えば、Ｎ，Ｎ’－メチレンビス（メタ）アクリルアミド、（ポリ）エチレングリコールジ（メタ）アクリレート、（ポリ）プロピレングリコールジ（メタ）アクリレート、トリメチロールプロパンジ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、グリセリントリ（メタ）アクリレート、グリセリンアクリレートメタクリレート、エチレンオキシド変性トリメチロールプロパントリ（メタ）アクリレート、ペンタエリスリトールテトラ（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレート、トリアリルシアヌレート、トリアリルイソシアヌレート、トリアリルホスフェート、トリアリルアミン、ポリ（メタ）アリロキシアルカン、（ポリ）エチレングリコールジグリシジルエーテル、グリセロールジグリシジルエーテル、エチレングリコール、ポリエチレングリコール、プロピレングリコール、グリセリン、ペンタエリスリトール、エチレンジアミン、ポリエチレンイミン、グリシジル（メタ）アクリレート等が挙げられる。これら内部架橋剤の中から、反応性等を考慮して少なくとも１種類の内部架橋剤が選択される。また、吸水剤の吸水性能等の観点から、好ましくは重合性不飽和基を二つ以上有する内部架橋剤、より好ましくは乾燥温度で熱分解性を有する内部架橋剤、さらに好ましくは（ポリ）アルキレングリコール構造を有する重合性不飽和基を二つ以上有する内部架橋剤が選択される。 (Internal cross-linking agent)
In a preferred manufacturing method, an internal cross-linking agent is used. Specific examples of the internal cross-linking agent include N, N'-methylenebis (meth) acrylamide, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, and trimethylolpropane. Di (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerintri (meth) acrylate, glycerin acrylate methacrylate, ethylene oxide-modified trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa ( Meta) acrylate, triallyl cyanurate, triallyl isocyanurate, triallyl phosphate, triallylamine, poly (meth) allyloxyalkane, (poly) ethylene glycol diglycidyl ether, glycerol diglycidyl ether, ethylene glycol, polyethylene glycol, propylene Glycol, glycerin, pentaerythritol, ethylenediamine, polyethyleneimine, glycidyl (meth) acrylate and the like can be mentioned. From these internal cross-linking agents, at least one kind of internal cross-linking agent is selected in consideration of reactivity and the like. Further, from the viewpoint of the water absorption performance of the water absorbing agent, an internal cross-linking agent having two or more polymerizable unsaturated groups is preferable, an internal cross-linking agent having thermal decomposability at a drying temperature is more preferable, and (poly) alkylene is more preferable. An internal cross-linking agent having two or more polymerizable unsaturated groups having a glycol structure is selected.
　前記重合性不飽和基としては、具体的には、アリル基、（メタ）アクリレート基が挙げられ、より好ましくは（メタ）アクリレート基である。また、前記（ポリ）アルキレングリコール構造としては、具体的には、ポリエチレングリコールが挙げられる。なお、アルキレングリコール単位の数（以下、ｎと表記する場合がある）としては、好ましくは１～１００、より好ましくは６～５０であり、さらにより好ましくは６～２０であり、最も好ましくは６～１０である。 Specific examples of the polymerizable unsaturated group include an allyl group and a (meth) acrylate group, more preferably a (meth) acrylate group. Specific examples of the (poly) alkylene glycol structure include polyethylene glycol. The number of alkylene glycol units (hereinafter, may be referred to as n) is preferably 1 to 100, more preferably 6 to 50, still more preferably 6 to 20, and most preferably 6. ~ 10.
　前記内部架橋剤の使用量は、単量体全体（但し、内部架橋剤は除く）に対して、好ましくは０．０００１モル％～１０モル％、より好ましくは０．００１モル％～５モル％、さらに好ましくは０．０１モル％～１モル％である。当該範囲内の使用量とすることで、所望する吸水性能を有する吸水剤が得られる。また吸水性樹脂や吸水剤のゲル嵩密度を所定の範囲にし、ゲル強度の低下に伴う水可溶分の増加や吸収倍率の低下を抑制するためにも、内部架橋剤量の調整を考慮することも好ましい。 The amount of the internal cross-linking agent used is preferably 0.0001 mol% to 10 mol%, more preferably 0.001 mol% to 5 mol%, based on the entire monomer (excluding the internal cross-linking agent). , More preferably 0.01 mol% to 1 mol%. By setting the amount to be used within the above range, a water-absorbing agent having a desired water-absorbing performance can be obtained. In addition, in order to keep the gel bulk density of the water-absorbent resin and water-absorbent within a predetermined range and suppress the increase in the water-soluble component and the decrease in the absorption ratio due to the decrease in gel strength, the adjustment of the amount of the internal cross-linking agent should be considered. It is also preferable.
　前記内部架橋剤は、単量体水溶液の作製時に予め添加しておくことが好ましく、この場合、重合反応と同時に架橋反応が行われる。一方、内部架橋剤を添加せずに重合反応を開始し、当該重合反応中または当該重合反応後に内部架橋剤を添加して架橋反応することもできる。また、これら手法を併用することもできる。 The internal cross-linking agent is preferably added in advance at the time of preparation of the monomer aqueous solution, and in this case, the cross-linking reaction is carried out at the same time as the polymerization reaction. On the other hand, it is also possible to start the polymerization reaction without adding the internal cross-linking agent and add the internal cross-linking agent during or after the polymerization reaction to carry out the cross-linking reaction. Moreover, these methods can also be used together.
　（単量体水溶液に添加される物質）
　本発明の実施形態では、前記単量体水溶液の作製時、前記重合反応および架橋反応の期間中、または前記重合反応および架橋反応の後の何れか１箇所以上で、吸水剤の物性向上の観点から、下記物質を単量体水溶液に添加することができる。 (Substance added to monomeric aqueous solution)
In the embodiment of the present invention, there is a viewpoint of improving the physical characteristics of the water-absorbing agent at any one or more points during the preparation of the monomer aqueous solution, during the polymerization reaction and the crosslinking reaction, or after the polymerization reaction and the crosslinking reaction. Therefore, the following substances can be added to the monomer aqueous solution.
　当該物質としては、具体的には、澱粉、澱粉誘導体、セルロース、セルロース誘導体、ポリビニルアルコール（ＰＶＡ）、ポリアクリル酸（塩）、ポリアクリル酸（塩）の架橋体等の親水性高分子；炭酸塩、アゾ化合物、各種気泡を生じる発泡剤、界面活性剤、キレート剤、連鎖移動剤等の化合物；が挙げられる。前記親水性高分子の添加量は、前記単量体水溶液に対して、好ましくは５０質量％以下、より好ましくは２０質量％以下、さらに好ましくは１０質量％以下、特に好ましくは５質量％以下である（下限は０質量％）。また、前記化合物の添加量は、前記単量体水溶液に対して、好ましくは５質量％以下、より好ましくは１質量％以下、さらに好ましくは０．５質量％以下である（下限は０質量％）。 Specific examples of the substance include hydrophilic polymers such as starch, starch derivatives, cellulose, cellulose derivatives, polyvinyl alcohol (PVA), polyacrylic acid (salt), and crosslinked polyacrylic acid (salt); carbonic acid. Examples thereof include salts, azo compounds, compounds such as foaming agents that generate various bubbles, surfactants, chelating agents, and chain transfer agents. The amount of the hydrophilic polymer added is preferably 50% by mass or less, more preferably 20% by mass or less, still more preferably 10% by mass or less, and particularly preferably 5% by mass or less, based on the aqueous monomer solution. There is (the lower limit is 0% by mass). The amount of the compound added is preferably 5% by mass or less, more preferably 1% by mass or less, still more preferably 0.5% by mass or less, based on the aqueous monomer solution (the lower limit is 0% by mass). ).
　前記親水性高分子として水溶性樹脂または吸水性樹脂を用いると、グラフト重合体または吸水性樹脂組成物（例えば、澱粉－アクリル酸（塩）共重合体、ＰＶＡ－アクリル酸（塩）共重合体等）が得られる。これらグラフト重合体または吸水性樹脂組成物も、本発明に係るポリアクリル酸（塩）系吸水性樹脂の範疇に含まれる。 When a water-soluble resin or a water-absorbent resin is used as the hydrophilic polymer, a graft polymer or a water-absorbent resin composition (for example, a starch-acrylic acid (salt) copolymer, a PVA-acrylic acid (salt) copolymer) is used. Etc.) is obtained. These graft polymers or water-absorbent resin compositions are also included in the category of the polyacrylic acid (salt) -based water-absorbent resin according to the present invention.
　（単量体成分の濃度）
　上述した各物質（成分）を目的に応じて種々選択し、必要に応じて、前記範囲を満たすようにそれぞれの量を規定して互いに混合することによって、単量体水溶液が作製される。なお、本発明では、単量体を水溶液とすること以外に、水と親水性溶媒との混合溶液とすることもできる。 (Concentration of monomer component)
A monomer aqueous solution is prepared by selecting various substances (components) described above according to the purpose, and if necessary, specifying the respective amounts so as to satisfy the above range and mixing them with each other. In the present invention, in addition to using the monomer as an aqueous solution, it can also be used as a mixed solution of water and a hydrophilic solvent.
　また、各物質（成分）の合計（以下、「単量体成分」とも表記する）の濃度は、吸水剤の物性の観点から、好ましくは１０質量％～８０質量％、より好ましくは２０質量％～７５質量％、さらに好ましくは３０質量％～７０質量％である。当該単量体成分の濃度は、下記式（２）から算出される。 Further, the total concentration of each substance (component) (hereinafter, also referred to as “monomer component”) is preferably 10% by mass to 80% by mass, more preferably 20% by mass from the viewpoint of the physical properties of the water absorbing agent. It is ~ 75% by mass, more preferably 30% by mass to 70% by mass. The concentration of the monomer component is calculated from the following formula (2).
Figure JPOXMLDOC01-appb-M000005
Figure JPOXMLDOC01-appb-M000005
　なお、前記式（２）中、（単量体水溶液の質量）には、グラフト成分や吸水性樹脂、逆相懸濁重合における疎水性有機溶媒の質量は含まれない。 In the formula (2), the mass of the graft component, the water-absorbent resin, and the hydrophobic organic solvent in the reverse phase suspension polymerization is not included in the (mass of the monomer aqueous solution).
　［２－２］　重合工程
　本工程は、前記単量体水溶液の調製工程で得られた、アクリル酸（塩）を主成分として含む単量体および少なくとも１種類の内部架橋剤を含む単量体水溶液を重合させて、含水ゲル状架橋重合体（以下、「含水ゲル」と表記する）を得る工程である。 [2-2] Polymerization step In this step, a monomer containing acrylic acid (salt) as a main component and a monomer containing at least one kind of internal cross-linking agent obtained in the step of preparing the aqueous monomer solution are used. This is a step of polymerizing an aqueous solution to obtain a hydrogel-like crosslinked polymer (hereinafter referred to as “hydrogen gel”).
　（重合開始剤）
　本発明の一実施形態においては、重合時に重合開始剤が使用される。当該重合開始剤としては、熱分解型重合開始剤、光分解型重合開始剤、または、これら重合開始剤の分解を促進する還元剤を併用したレドックス系重合開始剤が挙げられる。当該重合開始剤として、具体的には、過硫酸ナトリウム、過硫酸カリウム、過硫酸アンモニウム、ｔ－ブチルハイドロパーオキサイド、過酸化水素、２，２’－アゾビス（２－アミジノプロパン）二塩酸塩等のラジカル重合開始剤が挙げられる。これら重合開始剤の中から、重合形態等を考慮して少なくとも１種類の重合開始剤が選択される。また、重合開始剤の取り扱い性や吸水剤の物性の観点から、当該重合開始剤として、好ましくは過酸化物またはアゾ化合物、より好ましくは過酸化物、さらに好ましくは過硫酸塩が選択される。また、酸化性ラジカル重合開始剤を用いる場合には、例えば、亜硫酸ナトリウム、亜硫酸水素ナトリウム、硫酸第一鉄、Ｌ－アスコルビン酸等の還元剤を併用してレドックス重合を行ってもよい。 (Polymer initiator)
In one embodiment of the invention, a polymerization initiator is used during polymerization. Examples of the polymerization initiator include a thermal decomposition type polymerization initiator, a photodegradable polymerization initiator, and a redox-based polymerization initiator in which a reducing agent that promotes the decomposition of these polymerization initiators is used in combination. Specific examples of the polymerization initiator include sodium persulfate, potassium persulfate, ammonium persulfate, t-butyl hydroperoxide, hydrogen peroxide, and 2,2'-azobis (2-amidinopropane) dihydrochloride. Examples include radical polymerization initiators. From these polymerization initiators, at least one type of polymerization initiator is selected in consideration of the polymerization form and the like. Further, from the viewpoint of the handleability of the polymerization initiator and the physical properties of the water-absorbing agent, a peroxide or an azo compound, more preferably a peroxide, and further preferably a persulfate are selected as the polymerization initiator. When an oxidizing radical polymerization initiator is used, for example, a reducing agent such as sodium sulfite, sodium hydrogen sulfite, ferrous sulfate, or L-ascorbic acid may be used in combination to carry out redox polymerization.
　前記重合開始剤の使用量は、単量体全体（但し、内部架橋剤は除く）に対して、好ましくは０．００１モル％～１モル％、より好ましくは０．００１モル％～０．５モル％、さらに好ましくは０．０１モル％～０．１モル％である。また、前記還元剤の使用量は、単量体全体（但し、内部架橋剤は除く）に対して、好ましくは０．０００１モル％～０．０２モル％、より好ましくは０．０００５モル％～０．０１５モル％である。当該範囲内の使用量とすることで、所望する吸水性能を有する吸水剤が得られる。 The amount of the polymerization initiator used is preferably 0.001 mol% to 1 mol%, more preferably 0.001 mol% to 0.5, based on the entire monomer (excluding the internal cross-linking agent). It is mol%, more preferably 0.01 mol% to 0.1 mol%. The amount of the reducing agent used is preferably 0.0001 mol% to 0.02 mol%, more preferably 0.0005 mol% or more, based on the entire monomer (excluding the internal cross-linking agent). It is 0.015 mol%. By setting the amount to be used within the above range, a water-absorbing agent having a desired water-absorbing performance can be obtained.
　また、本発明の一実施形態においては、前記重合反応を、熱エネルギー、あるいは、放射線、電子線、紫外線等の活性エネルギー線の照射によって開始させてもよい。また、活性エネルギー線の照射と前記重合開始剤とを併用してもよい。 Further, in one embodiment of the present invention, the polymerization reaction may be started by irradiation with thermal energy or active energy rays such as radiation, electron beam, and ultraviolet rays. Further, irradiation with active energy rays and the polymerization initiator may be used in combination.
　（重合形態）
　本発明に適用される重合形態としては、水溶液重合、逆相懸濁重合、噴霧重合、液滴重合、バルク重合、沈澱重合等が挙げられる。中でも、重合の制御の容易性や吸水剤の吸水性能の観点から、好ましくは水溶液重合または逆相懸濁重合、より好ましくは水溶液重合、さらに好ましくは連続水溶液重合が選択される。逆相懸濁重合は国際公開第２００７／００４５２９号、国際公開第２０１２／０２３４３３号などに記載されている。また当該連続水溶液重合は、吸水剤を高い生産性で製造することができ、その具体例としては、米国特許第４８９３９９９号、米国特許第６９０６１５９号、米国特許第７０９１２５３号、米国特許第７７４１４００号、米国特許第８５１９２１２号、特開２００５－３６１００号公報等に記載された連続ベルト重合や、米国特許第６９８７１５１号等に記載された連続ニーダー重合が挙げられる。 (Polymerization form)
Examples of the polymerization form applied to the present invention include aqueous solution polymerization, reverse phase suspension polymerization, spray polymerization, droplet polymerization, bulk polymerization, precipitation polymerization and the like. Among them, from the viewpoint of ease of polymerization control and water absorption performance of the water-absorbing agent, aqueous solution polymerization or reverse phase suspension polymerization is more preferable, aqueous solution polymerization is more preferable, and continuous aqueous solution polymerization is more preferable. Reversed phase suspension polymerization is described in International Publication No. 2007/004529, International Publication No. 2012/023433 and the like. Further, the continuous aqueous solution polymerization can produce a water absorbing agent with high productivity, and specific examples thereof include US Pat. No. 4,893999, US Pat. No. 6,906,159, US Pat. No. 7,091253, and US Pat. No. 7,741400. Examples thereof include continuous belt polymerization described in US Pat. No. 8519212, JP-A-2005-36100, and continuous kneader polymerization described in US Pat. No. 6,987,151.
　前記連続水溶液重合の好ましい形態としては、高温開始重合、高濃度重合、発泡重合等がある。高温開始重合は、重合開始時の単量体水溶液の温度を、好ましくは３０℃以上、より好ましくは３５℃以上、さらに好ましくは４０℃以上、特に好ましくは５０℃以上とする（上限は単量体水溶液の沸点）重合形態である。高濃度重合は、重合開始時の単量体濃度を、好ましくは３０質量％以上、より好ましくは３５質量％以上、さらに好ましくは４０質量％以上、特に好ましくは４５質量％以上とする（上限は単量体水溶液の飽和濃度）重合形態である。 Preferred forms of the continuous aqueous solution polymerization include high temperature start polymerization, high concentration polymerization, foam polymerization and the like. In the high temperature start polymerization, the temperature of the aqueous monomer solution at the start of polymerization is preferably 30 ° C. or higher, more preferably 35 ° C. or higher, further preferably 40 ° C. or higher, and particularly preferably 50 ° C. or higher (upper limit is a single amount). Boiling point of body aqueous solution) Polymerization form. In high-concentration polymerization, the monomer concentration at the start of polymerization is preferably 30% by mass or more, more preferably 35% by mass or more, still more preferably 40% by mass or more, and particularly preferably 45% by mass or more (upper limit is 45% by mass). Saturation concentration of monomeric aqueous solution) Polymerization form.
　また、上述した各重合形態は、空気雰囲気下で実施可能であるが、吸水剤の色調の観点から、窒素やアルゴン等の不活性ガス雰囲気下（酸素濃度が１容積％以下）で実施することが好ましい。なお、単量体水溶液中の溶存酸素に関しても、不活性ガスを用いて十分に置換（溶存酸素量が１ｍｇ／Ｌ未満）しておくことが好ましい。 Further, each of the above-mentioned polymerization forms can be carried out in an air atmosphere, but from the viewpoint of the color tone of the water absorbing agent, it should be carried out in an inert gas atmosphere such as nitrogen or argon (oxygen concentration is 1 volume% or less). Is preferable. It is also preferable that the dissolved oxygen in the monomer aqueous solution is sufficiently substituted with an inert gas (the amount of dissolved oxygen is less than 1 mg / L).
　発泡重合で発泡形状（別称；多孔質）の含水ゲルや吸水性樹脂や吸水剤とすることで、吸水剤の吸水速度が向上でき、また吸水剤の吸収物品での固定化も容易になる。発泡形状であることは電子顕微鏡での粒子表面の孔（例えば直径１～１００μｍの孔）などで確認できる。孔は吸水剤ひとつあたり好ましくは１個以上、さらには１～１００００個、１０～１０００個程度であり、前記発泡重合で制御できる。 By using a water-containing gel with a foamed shape (also known as porous), a water-absorbing resin, or a water-absorbing agent by foam polymerization, the water-absorbing rate of the water-absorbing agent can be improved, and the water-absorbing agent can be easily immobilized on the absorbing article. The foamed shape can be confirmed by the holes on the surface of the particles (for example, holes having a diameter of 1 to 100 μm) with an electron microscope. The number of pores is preferably one or more, more preferably 1 to 10000, and 10 to 1000 per water absorbing agent, and can be controlled by the foam polymerization.
　前記発泡重合は、後述する吸水性樹脂や吸水剤のＢＥＴ比表面積を高める上で、好ましい技術である。 The foam polymerization is a preferable technique for increasing the BET specific surface area of the water-absorbent resin and the water-absorbent agent described later.
　［２－３］　ゲル粉砕工程
　本工程は、前記重合工程で得られた含水ゲルをゲル粉砕して、粒子状の含水ゲル（以下、「粒子状含水ゲル」とも表記する）を得る工程である。なお、後述する粉砕工程での「粉砕」と区別するために、本工程は「ゲル粉砕」と表記する。 [2-3] Gel crushing step This step is a step of gel crushing the hydrous gel obtained in the polymerization step to obtain a particulate hydrogel (hereinafter, also referred to as “particulate hydrogel”). .. In addition, in order to distinguish from "crushing" in the crushing step described later, this step is referred to as "gel crushing".
　前記ゲル粉砕とは、ニーダー、ミートチョッパー、カッターミル等のゲル粉砕機を用いて、含水ゲルを所定の大きさに調整することを指す。 The gel crushing refers to adjusting the water-containing gel to a predetermined size using a gel crusher such as a kneader, a meat chopper, or a cutter mill.
　ゲル粉砕の実施形態や稼働条件等に関しては、国際公開第２０１１／１２６０７９号パンフレットに記載された内容が本発明に好ましく適用される。なお、重合形態がニーダー重合である場合には、重合工程とゲル粉砕工程とが同時に実施されていることになる。また、逆相懸濁重合、噴霧重合または液滴重合等、粒子状含水ゲルが重合工程で得られる場合には、ゲル粉砕工程が当該重合工程と同時に実施されているとみなす。また、本発明でゲル粉砕工程を経ることで、不定形破砕状の吸水性樹脂や吸水剤を得ることができる。 Regarding the embodiment of gel crushing, operating conditions, etc., the contents described in International Publication No. 2011/126079 pamphlet are preferably applied to the present invention. When the polymerization form is kneader polymerization, the polymerization step and the gel crushing step are carried out at the same time. Further, when a particulate hydrogel such as reverse phase suspension polymerization, spray polymerization or droplet polymerization is obtained in the polymerization step, it is considered that the gel pulverization step is carried out at the same time as the polymerization step. Further, by going through the gel crushing step in the present invention, an amorphous crushed water-absorbent resin or a water-absorbent agent can be obtained.
　ゲル粉砕工程によって細粒化されたゲルは、一般に０．１～１０ｍｍの範囲が好ましい。０．１ｍｍよりもゲルが細かいと得られる吸水性樹脂の物性の低いものとなる恐れがある。１０ｍｍよりも大きいと乾燥されにくくなる恐れがある。また前記粒子状含水ゲルの質量平均粒子径（Ｄ５０）は好ましくは５００μｍ～２０００μｍ、より好ましくは５５０μｍ～１５００μｍ、さらに好ましくは６００μｍ～１０００μｍである。 The gel granulated by the gel crushing step is generally preferably in the range of 0.1 to 10 mm. If the gel is finer than 0.1 mm, the physical properties of the obtained water-absorbent resin may be low. If it is larger than 10 mm, it may be difficult to dry. The mass average particle diameter (D50) of the particulate hydrogel is preferably 500 μm to 2000 μm, more preferably 550 μm to 1500 μm, and further preferably 600 μm to 1000 μm.
　なお、後述する吸水性樹脂や吸水剤の比表面積を高めるためには、国際公開第２０１１／１２６０７９号パンフレットに記載されたゲル粉砕方法を用いることが好ましい。また、該ゲル粉砕技術を前述の発泡重合と組み合わせてもよい。 In order to increase the specific surface area of the water-absorbent resin or water-absorbent agent described later, it is preferable to use the gel crushing method described in International Publication No. 2011/126079 pamphlet. Further, the gel pulverization technique may be combined with the above-mentioned foam polymerization.
　前記粒子状含水ゲルの質量平均粒子径（Ｄ５０）の測定法は、国際公開第２０１１／１２６０７９号パンフレットに記載された方法で行われる。 The method for measuring the mass average particle diameter (D50) of the particulate hydrogel is the method described in International Publication No. 2011/126079.
　［２－４］　乾燥工程
　本工程は、前記重合工程及び／又はゲル粉砕工程で得られた含水ゲル及び／又は粒子状含水ゲルを所望する樹脂固形分まで乾燥させて乾燥重合体を得る工程である。該樹脂固形分は、乾燥減量（吸水性樹脂１ｇを１８０℃で３時間加熱した際の質量変化）から求められ、好ましくは８０質量％以上、より好ましくは８５質量％～９９質量％、さらに好ましくは９０質量％～９８質量％、特に好ましくは９２質量％～９７質量％である。 [2-4] Drying Step This step is a step of drying the hydrous gel and / or the particulate hydrogel obtained in the polymerization step and / or the gel pulverization step to a desired resin solid content to obtain a dry polymer. be. The resin solid content is determined by drying weight loss (mass change when 1 g of water-absorbent resin is heated at 180 ° C. for 3 hours), and is preferably 80% by mass or more, more preferably 85% by mass to 99% by mass, and further preferably. Is 90% by mass to 98% by mass, particularly preferably 92% by mass to 97% by mass.
　前記含水ゲル及び／又は粒子状含水ゲルの乾燥方法は、例えば、加熱乾燥、熱風乾燥、減圧乾燥、流動層乾燥、赤外線乾燥、マイクロ波乾燥、ドラムドライヤー乾燥、疎水性有機溶媒との共沸脱水による乾燥、高温の水蒸気を利用した高湿乾燥等が挙げられる。中でも乾燥効率の観点から、熱風乾燥が好ましく、通気ベルト上で熱風乾燥を行うバンド乾燥がより好ましい。 The drying method of the hydrous gel and / or the particulate hydrogel is, for example, heat drying, hot air drying, vacuum drying, fluidized layer drying, infrared drying, microwave drying, drum dryer drying, co-boiling dehydration with a hydrophobic organic solvent. Drying by, high humidity drying using high temperature steam, etc. can be mentioned. Above all, from the viewpoint of drying efficiency, hot air drying is preferable, and band drying in which hot air drying is performed on a ventilation belt is more preferable.
　前記熱風乾燥における乾燥温度（熱風の温度）としては、吸水性樹脂の色調や乾燥効率の観点から、好ましくは１２０℃～２５０℃、より好ましくは１４０℃～２００℃である。なお、熱風の風速や乾燥時間等、前記乾燥温度以外の乾燥条件については、乾燥に供する粒子状含水ゲルの含水率や総質量及び目的とする樹脂固形分に応じて、適宜設定すればよく、バンド乾燥を行う際には、国際公開第２００６／１００３００号パンフレット、同第２０１１／０２５０１２号パンフレット、同第２０１１／０２５０１３号パンフレット、同第２０１１／１１１６５７号パンフレット等に記載される諸条件が適宜適用される。 The drying temperature (hot air temperature) in the hot air drying is preferably 120 ° C. to 250 ° C., more preferably 140 ° C. to 200 ° C. from the viewpoint of the color tone of the water-absorbent resin and the drying efficiency. Drying conditions other than the drying temperature, such as the wind speed and drying time of hot air, may be appropriately set according to the water content and total mass of the particulate hydrogel to be dried and the target resin solid content. When the band is dried, the conditions described in the international publication 2006/100300 pamphlet, 2011/025012 pamphlet, 2011/025013 pamphlet, 2011/11657 pamphlet, etc. are appropriately applied. Will be done.
　また、乾燥時間は、好ましくは１０分間～２時間、より好ましくは２０分間～１５０分、さらに好ましくは３０分間～１００分である。当該範囲内の乾燥温度および乾燥時間とすることで、得られる吸水剤の物性を所望する範囲とすることができる。また、中間生成物としての吸水性樹脂の物性に関しても、所望する範囲とすることができる。 The drying time is preferably 10 minutes to 2 hours, more preferably 20 minutes to 150 minutes, and even more preferably 30 minutes to 100 minutes. By setting the drying temperature and drying time within the above range, the physical characteristics of the obtained water-absorbing agent can be set within a desired range. Further, the physical characteristics of the water-absorbent resin as an intermediate product can also be set within a desired range.
　［２－５］　粉砕工程、分級工程
　本工程は、前記乾燥工程を経て得られる乾燥重合体を、粉砕（粉砕工程）し、所望する範囲の粒度に調整（分級工程）して、ベースポリマー（表面架橋を施す前の吸水性樹脂）を得る工程である。乾燥後の粉砕工程を経ることで、不定形破砕状の吸水性樹脂や吸水剤を得ることができる。粉砕は必要に応じて２回以上行ってもよい。粉砕工程、分級工程における条件を適宜調整することによって、所望するスパン値を満たすベースポリマー（表面架橋を施す前の吸水性樹脂）を得ることができ、ひいては所望するスパン値を満たす吸水性樹脂組成物を得ることができる。 [2-5] Grinding Step, Classification Step In this step, the dry polymer obtained through the drying step is ground (grinding step) and adjusted to a desired particle size (classifying step) to obtain a base polymer (classification step). This is a step of obtaining a water-absorbent resin) before surface cross-linking. By going through the pulverization step after drying, an amorphous crushed water-absorbent resin or a water-absorbing agent can be obtained. Grinding may be performed twice or more if necessary. By appropriately adjusting the conditions in the pulverization step and the classification step, a base polymer (water-absorbent resin before surface cross-linking) satisfying a desired span value can be obtained, and by extension, a water-absorbent resin composition satisfying the desired span value. You can get things.
　前記粉砕工程で使用される粉砕機としては、ロールミル、ハンマーミル、スクリューミル、ピンミル等の高速回転式粉砕機や、振動ミル、ナックルタイプ粉砕機、円筒型ミキサー等が挙げられる。中でも、粉砕効率の観点から、好ましくはロールミルが選択される。また、これら粉砕機を複数併用することもできる。 Examples of the crusher used in the crushing step include high-speed rotary crushers such as roll mills, hammer mills, screw mills, and pin mills, vibration mills, knuckle type crushers, and cylindrical mixers. Of these, a roll mill is preferably selected from the viewpoint of pulverization efficiency. Further, a plurality of these crushers can be used in combination.
　前記分級工程での粒度の調整方法としては、ＪＩＳ標準篩（ＪＩＳ　Ｚ８８０１－１（２０００））を用いた篩分級や気流分級等が挙げられる。中でも、分級効率の観点から、好ましくは篩分級が選択される。なお、吸水剤の粒度の調整は、粉砕工程や分級工程での実施に限定されず、重合工程（特に逆相懸濁重合や液滴重合等）や、その他の工程（例えば、造粒工程や微粉回収工程）で実施することもできる。 Examples of the method for adjusting the particle size in the classification step include sieve classification using a JIS standard sieve (JIS Z8801-1 (2000)), air flow classification, and the like. Above all, sieving classification is preferably selected from the viewpoint of classification efficiency. The adjustment of the particle size of the water absorbent is not limited to the pulverization step and the classification step, but is not limited to the polymerization step (particularly reverse phase suspension polymerization, droplet polymerization, etc.) and other steps (for example, granulation step). It can also be carried out in the fine powder recovery process).
　本発明の一実施形態においては、ベースポリマーの質量平均粒子径（Ｄ５０）が３００～６００μｍである。また、本発明の一実施形態においては、ベースポリマーの１５０μｍ未満の粒子の割合が５質量％以下である。なお、１５０μｍ未満の粒子の割合の下限は、０質量％である。ベースポリマーの質量平均粒子径（Ｄ５０）は３００～５００μｍであることが好ましく、３００～４５０μｍであることがより好ましい。ベースポリマーの１５０μｍ未満の粒子の割合は、４質量％以下であることがより好ましく、３質量％以下であることがさらに好ましく、２質量％以下であることが特に好ましい。 In one embodiment of the present invention, the mass average particle size (D50) of the base polymer is 300 to 600 μm. Further, in one embodiment of the present invention, the proportion of particles smaller than 150 μm in the base polymer is 5% by mass or less. The lower limit of the proportion of particles smaller than 150 μm is 0% by mass. The mass average particle size (D50) of the base polymer is preferably 300 to 500 μm, more preferably 300 to 450 μm. The proportion of particles of less than 150 μm in the base polymer is more preferably 4% by mass or less, further preferably 3% by mass or less, and particularly preferably 2% by mass or less.
　本発明の一実施形態においては、上記スパン値は、１．１０以下である。１．１０を超えると本発明の所期の効果を達成することができない。本発明の実施形態によれば、好ましくは０．４０以上となるように調整され、より好ましくは０．４０～１．１０となるように調整され、よりさらに好ましくは０．４５～１．０５となるように調整され、よりさらに好ましくは０．５０～１．００となるように調整される。 In one embodiment of the present invention, the span value is 1.10 or less. If it exceeds 1.10, the desired effect of the present invention cannot be achieved. According to the embodiment of the present invention, it is preferably adjusted to be 0.40 or more, more preferably 0.40 to 1.10, and even more preferably 0.45 to 1.05. It is adjusted so as to be 0.50 to 1.00, and more preferably 0.50 to 1.00.
　本発明の一実施形態において上述したスパン値は、表面架橋後の吸水性樹脂のみならず、最終製品としての吸水剤（粒子状吸水剤）についても適用されうる。そのため、ベースポリマーで調整された前記スパン値を維持するように、表面架橋処理（表面架橋工程）されることが好ましく、表面架橋工程以降に適宜整粒工程を設けて特定のスパン値に調整されることがより好ましい。 The span value described above in one embodiment of the present invention can be applied not only to the water-absorbent resin after surface cross-linking but also to the water-absorbing agent (particulate water-absorbing agent) as a final product. Therefore, it is preferable to carry out a surface cross-linking treatment (surface cross-linking step) so as to maintain the span value adjusted by the base polymer, and an appropriate granulation step is provided after the surface cross-linking step to adjust the span value to a specific span value. Is more preferable.
　本発明の一実施形態において前記ベースポリマーの質量平均粒子径（Ｄ５０）も、表面架橋後の吸水性樹脂のみならず、最終製品としての吸水剤（粒子状吸水剤）についても適用されうる。そのため、ベースポリマーで調整された前記質量平均粒子径（Ｄ５０）を維持することが好ましい。よって、前記吸水性樹脂組成物の質量平均粒子径（Ｄ５０）も、３００～６００μｍであることが好ましく、３００～５００μｍであることがより好ましく、３００～４５０μｍであることがさらに好ましい。 In one embodiment of the present invention, the mass average particle size (D50) of the base polymer can be applied not only to the water-absorbent resin after surface cross-linking but also to the water-absorbing agent (particulate water-absorbing agent) as a final product. Therefore, it is preferable to maintain the mass average particle size (D50) adjusted with the base polymer. Therefore, the mass average particle size (D50) of the water-absorbent resin composition is also preferably 300 to 600 μm, more preferably 300 to 500 μm, and even more preferably 300 to 450 μm.
　［２－６］　表面架橋工程
　本工程は、上述した各工程を経て得られるベースポリマーの表面層に、さらに架橋密度の高い部分を設ける工程であり、混合工程、熱処理工程、必要に応じて冷却工程等を含む構成となっている。当該表面架橋工程において、ベースポリマーの表面でラジカル架橋や表面重合、表面架橋剤との架橋反応等が起こり、表面架橋された吸水性樹脂が得られる。 [2-6] Surface cross-linking step This step is a step of providing a portion having a higher cross-linking density on the surface layer of the base polymer obtained through each of the above steps, and is a mixing step, a heat treatment step, and cooling as necessary. The structure includes processes and the like. In the surface cross-linking step, radical cross-linking, surface polymerization, a cross-linking reaction with a surface cross-linking agent and the like occur on the surface of the base polymer, and a surface-crosslinked water-absorbent resin can be obtained.
　［２－６－１］　混合工程
　本工程は、表面架橋剤を含む溶液（以下、「表面架橋剤溶液」と表記する）を混合装置内でベースポリマーと混合することで、加湿混合物を得る工程である。 [2-6-1] Mixing step In this step, a solution containing a surface cross-linking agent (hereinafter referred to as “surface cross-linking agent solution”) is mixed with a base polymer in a mixing device to obtain a humidified mixture. Is.
　（表面架橋剤）
　本発明の一実施形態においては、表面架橋時に表面架橋剤が使用される。当該表面架橋剤としては、具体的には米国特許第７１８３４５６号に記載された表面架橋剤が挙げられる。これら表面架橋剤の中から、反応性等を考慮して少なくとも１種類の表面架橋剤が選択される。また、表面架橋剤の取り扱い性や吸水剤の吸水性能等の観点から、好ましくはカルボキシル基と反応する官能基を二つ以上有する表面架橋剤であって、共有結合が形成される有機化合物が選択される。 (Surface cross-linking agent)
In one embodiment of the invention, a surface cross-linking agent is used during surface cross-linking. Specific examples of the surface cross-linking agent include the surface cross-linking agent described in US Pat. No. 7,183,456. From these surface cross-linking agents, at least one kind of surface cross-linking agent is selected in consideration of reactivity and the like. Further, from the viewpoint of the handleability of the surface cross-linking agent and the water-absorbing performance of the water-absorbing agent, a surface cross-linking agent having two or more functional groups that react with a carboxyl group, and an organic compound forming a covalent bond is preferably selected. Will be done.
　前記表面架橋剤として、より具体的には、エチレングリコール、ジエチレングリコール、トリエチレングリコール、テトラエチレングリコール、ポリエチレングリコール、１，３－プロパンジオール、プロピレングリコール、１，４－ブタンジオール、１，２－ブタンジオール、１，３－ブタンジオール、２，３－ブタンジオール、１，５－ペンタンジオール、１，４－ペンタンジオール、１，３－ペンタンジオール、１，２－ペンタンジオール、２，３－ペンタンジオール、２，４－ペンタンジオール、ジプロピレングリコール、ポリプロピレングリコール、グリセリン、ポリグリセリン、１，６－ヘキサンジオール、１，５－ヘキサンジオール、１，４－ヘキサンジオール、１，３－ヘキサンジオール、１，２－ヘキサンジオール、２，３－ヘキサンジオール、２，４－ヘキサンジオール、ジエタノールアミン、トリエタノールアミンなどの多価アルコール化合物、エチレンジアミン、ジエチレントリアミン、トリエチレンテトラミン、テトラエチレンペンタミン、ペンタエチレンヘキサミン、ポリアリルアミン、ポリエチレンイミン等の多価アミン化合物、ハロエポキシ化合物、多価アミン化合物とハロエポキシ化合物との縮合物、１，２－エチレンビスオキサゾリン等のオキサゾリン化合物、オキサゾリジノン化合物、１，３－ジオキソラン－２－オン（エチレンカーボネート）、４－メチル－１，３－ジオキソラン－２－オン、４，５－ジメチル－１，３－ジオキソラン－２－オン、４，４－ジメチル－１，３－ジオキソラン－２－オン、４－エチル－１，３－ジオキソラン－２－オン、４－ヒドロキシメチル－１，３－ジオキソラン－２－オン、１，３－ジオキサン－２－オン、４－メチル－１，３－ジオキサン－２－オン、４，６－ジメチル－１，３－ジオキサン－２－オン、１，３－ジオキソパン－２－オンなどのアルキレンカーボネート化合物、エチレングリコールジグリシジルエーテル、ポリエチレンジグリシジルエーテル、グリセロールポリグリシジルエーテル、ジグリセロールポリグリシジルエーテル、ポリグリセロールポリグリシジルエーテル、プロピレングリコールジグリシジルエーテル、ポリプロピレングリコールジグリシジルエーテル、グリシド－ルなどの多価グリシジル化合物、オキセタン化合物、ビニルエーテル化合物等が挙げられる。好ましい表面架橋剤は、プロピレングリコール、１，３－プロパンジオールなどの多価アルコール化合物、エチレンカーボネートなどのアルキレンカーボネート化合物、エチレングリコールジグリシジルエーテルなどの多価グリシジル化合物、ジエチレントリアミンなどの多価アミンなどである。 More specifically, the surface cross-linking agent includes ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, and 1,2-butane. Diole, 1,3-Butanediol, 2,3-Butanediol, 1,5-Pentanediol, 1,4-Pentanediol, 1,3-Pentanediol, 1,2-Pentanediol, 2,3-Pentanediol , 2,4-pentanediol, dipropylene glycol, polypropylene glycol, glycerin, polyglycerin, 1,6-hexanediol, 1,5-hexanediol, 1,4-hexanediol, 1,3-hexanediol, 1, Polyhydric alcohol compounds such as 2-hexanediol, 2,3-hexanediol, 2,4-hexanediol, diethanolamine, triethanolamine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyallylamine , Polyvalent amine compound such as polyethyleneimine, haloepoxy compound, condensate of polyvalent amine compound and haloepoxy compound, oxazoline compound such as 1,2-ethylenebisoxazoline, oxazolidinone compound, 1,3-dioxolan-2-one ( Ethylene carbonate), 4-methyl-1,3-dioxolan-2-one, 4,5-dimethyl-1,3-dioxolan-2-one, 4,4-dimethyl-1,3-dioxolan-2-one, 4-Ethylene-1,3-dioxolan-2-one, 4-hydroxymethyl-1,3-dioxolan-2-one, 1,3-dioxane-2-one, 4-methyl-1,3-dioxane-2 Alkylene carbonate compounds such as -on, 4,6-dimethyl-1,3-dioxane-2-one, 1,3-dioxopan-2-one, ethylene glycol diglycidyl ether, polyethylene diglycidyl ether, glycerol polyglycidyl ether, Examples thereof include polyvalent glycidyl compounds such as diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and glycidol, oxetane compounds, and vinyl ether compounds. Preferred surface cross-linking agents include polyhydric alcohol compounds such as propylene glycol and 1,3-propanediol, alkylene carbonate compounds such as ethylene carbonate, polyhydric glycidyl compounds such as ethylene glycol diglycidyl ether, and polyhydric amines such as diethylenetriamine. be.
　前記表面架橋剤の使用量（複数種類を使用する場合はその合計量）は、ベースポリマー１００質量部に対して、好ましくは０．０１質量部～１０質量部、より好ましくは０．０１質量部～５質量部、さらに好ましくは０．０１質量部～２質量部であり、よりさらに好ましくは０．１質量部～１．８質量部であり、よりさらに好ましくは０．５質量部～１．５質量部である。表面架橋剤の使用量を当該範囲内とすることで、ベースポリマーの表面層に最適な架橋構造を形成することができ、高物性の吸水性樹脂や吸水剤が得られる。また種類に合わせて表面架橋剤の量を調整することは、吸水性樹脂や吸水剤のゲル嵩密度を適正化するのにも有効である。 The amount of the surface cross-linking agent used (in the case of using a plurality of types, the total amount thereof) is preferably 0.01 part by mass to 10 parts by mass, and more preferably 0.01 part by mass with respect to 100 parts by mass of the base polymer. It is ~ 5 parts by mass, more preferably 0.01 part by mass to 2 parts by mass, further preferably 0.1 part by mass to 1.8 part by mass, and even more preferably 0.5 part by mass to 1. 5 parts by mass. By setting the amount of the surface cross-linking agent to be within the range, an optimum cross-linked structure can be formed on the surface layer of the base polymer, and a water-absorbent resin or a water-absorbent agent having high physical characteristics can be obtained. Further, adjusting the amount of the surface cross-linking agent according to the type is also effective for optimizing the gel bulk density of the water-absorbent resin and the water-absorbent agent.
　前記表面架橋剤は、水溶液の形態でベースポリマーに添加することが好ましい。この場合、水の使用量は、ベースポリマー１００質量部に対して、好ましくは０．１質量部～２０質量部、より好ましくは０．３質量部～１５質量部、さらに好ましくは０．５質量部～１０質量部である。水の使用量を当該範囲内とすることで、表面架橋剤溶液の取り扱い性が向上し、ベースポリマーに対して表面架橋剤を均等に混合することができる。 The surface cross-linking agent is preferably added to the base polymer in the form of an aqueous solution. In this case, the amount of water used is preferably 0.1 part by mass to 20 parts by mass, more preferably 0.3 part by mass to 15 parts by mass, and further preferably 0.5 part by mass with respect to 100 parts by mass of the base polymer. It is 10 parts by mass. By setting the amount of water used within the above range, the handleability of the surface cross-linking agent solution is improved, and the surface cross-linking agent can be evenly mixed with the base polymer.
　また、親水性有機溶媒を必要に応じて前記水と併用して、前記表面架橋剤溶液とすることもできる。この場合、親水性有機溶媒の使用量は、不快臭の原因とならないように少ない方が好ましく、ベースポリマー１００質量部に対して、好ましくは５質量部以下、より好ましくは３質量部以下、さらに好ましくは２質量部以下、よりさらに好ましくは１質量部以下である。ただし、適度な表面架橋を行う観点では親水性有機溶媒を添加する方が好ましく、添加量としては、ベースポリマー１００質量部に対して、０．１質量部以上が好ましく、０．５質量部以上がより好ましい。 Further, a hydrophilic organic solvent can be used in combination with the water as needed to prepare the surface cross-linking agent solution. In this case, the amount of the hydrophilic organic solvent used is preferably small so as not to cause an unpleasant odor, preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and further, with respect to 100 parts by mass of the base polymer. It is preferably 2 parts by mass or less, and even more preferably 1 part by mass or less. However, from the viewpoint of performing appropriate surface cross-linking, it is preferable to add a hydrophilic organic solvent, and the amount to be added is preferably 0.1 part by mass or more, and 0.5 part by mass or more with respect to 100 parts by mass of the base polymer. Is more preferable.
　当該親水性有機溶媒としては、具体的には、メチルアルコール、イソプロピルアルコール等の低級（例えば、炭素数１～３）アルコール類；アセトン等のケトン類；ジオキサン等のエーテル類；Ｎ，Ｎ－ジメチルホルムアミド等のアミド類；ジメチルスルホキシド等のスルホキシド類等が挙げられる。 Specific examples of the hydrophilic organic solvent include lower (for example, 1 to 3 carbon atoms) alcohols such as methyl alcohol and isopropyl alcohol; ketones such as acetone; ethers such as dioxane; N, N-dimethyl. Amides such as formamide; sulfoxides such as dimethyl sulfoxide and the like can be mentioned.
　（混合方法、混合条件）
　前記ベースポリマーと前記表面架橋剤溶液との混合は、表面架橋剤溶液を予め作製しておき、当該溶液をベースポリマーに対して、好ましくは噴霧または滴下して、より好ましくは噴霧して混合する方法が選択される。 (Mixing method, mixing conditions)
For mixing the base polymer and the surface cross-linking agent solution, a surface cross-linking agent solution is prepared in advance, and the solution is preferably sprayed or dropped onto the base polymer, and more preferably sprayed and mixed. The method is selected.
　［２－６－２］　熱処理工程
　本工程は、前記混合工程で得られた加湿混合物に熱を加えて、ベースポリマーの表面上で架橋反応させる工程である。 [2-6-2] Heat Treatment Step This step is a step of applying heat to the humidified mixture obtained in the mixing step to cause a crosslinking reaction on the surface of the base polymer.
　前記加湿混合物の熱処理は、当該加湿混合物を静置状態で加熱してもよく、攪拌等の動力を用いて流動状態で加熱してもよいが、加湿混合物全体を均等に加熱できる点において、攪拌下で加熱することが好ましい。前記熱処理を行う熱処理装置は、前記観点から、パドルドライヤー、マルチフィンプロセッサー、タワードドライヤー等が挙げられる。 In the heat treatment of the humidified mixture, the humidified mixture may be heated in a stationary state or may be heated in a fluid state by using a power such as stirring, but the humidified mixture can be heated evenly in that the whole humidified mixture can be heated evenly. It is preferable to heat underneath. From the above viewpoint, the heat treatment apparatus that performs the heat treatment includes a paddle dryer, a multi-fin processor, a tower dryer and the like.
　本工程における加熱温度は、表面架橋剤の種類および量、並びに吸水剤の吸水性能等の観点から、好ましくは１５０℃～２５０℃、より好ましくは１７０℃～２５０℃、さらに好ましくは１８０℃～２３０℃である。また、加熱時間は少なくとも５分間、好ましくは少なくとも７分間である。上限としては、１５０分以下が好ましく、１２０分以下がより好ましく、１００分以下がさらに好ましい。加熱温度と加熱時間とを前記範囲内に制御することにより、得られる吸水剤の吸水性能が向上するため好ましい。 The heating temperature in this step is preferably 150 ° C. to 250 ° C., more preferably 170 ° C. to 250 ° C., still more preferably 180 ° C. to 230, from the viewpoint of the type and amount of the surface cross-linking agent and the water absorption performance of the water absorbing agent. ℃. The heating time is at least 5 minutes, preferably at least 7 minutes. The upper limit is preferably 150 minutes or less, more preferably 120 minutes or less, and even more preferably 100 minutes or less. By controlling the heating temperature and the heating time within the above range, the water absorption performance of the obtained water absorbing agent is improved, which is preferable.
　［２－６－３］　冷却工程
　本工程は、前記熱処理工程の後に必要に応じて設けられる任意の工程である。本工程は、前記熱処理工程を終えた高温の吸水性樹脂を所定の温度まで強制冷却し、表面架橋反応を速やかに終了させる工程である。 [2-6-3] Cooling step This step is an arbitrary step provided as necessary after the heat treatment step. This step is a step of forcibly cooling the high-temperature water-absorbent resin that has completed the heat treatment step to a predetermined temperature to promptly terminate the surface cross-linking reaction.
　［２－７］　疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分の添加
　本工程は、疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分の添加を行う工程である。換言すれば、本発明の一実施形態において、吸水性樹脂組成物が疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分を含む。かような構成を有することによって、従来の消臭剤を使った吸水性樹脂組成物に対してより優れた消臭能を有する。以下に、より優れた消臭能を有するメカニズムを説明する。ただし、かかるメカニズムは推測であり、かかるメカニズムによって本発明の技術的範囲は制限されない。 [2-7] Addition of at least one component of the hydrophobic porous polymer adsorbent and the resin having a nitrogen-containing heterocycle In this step, at least one of the hydrophobic porous polymer adsorbent and the resin having a nitrogen-containing heterocycle is added. This is a process of adding components. In other words, in one embodiment of the invention, the water-absorbent resin composition comprises at least one component of a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle. By having such a structure, it has a more excellent deodorizing ability than a water-absorbent resin composition using a conventional deodorant. The mechanism having a better deodorizing ability will be described below. However, such a mechanism is speculative and does not limit the technical scope of the invention.
　尿臭の原因物質としては、まず、尿素やアミノ酸の分解によって発生する「アンモニアやアミン類」などの塩基性化合物や「フェノール類」など中程度分子サイズの疎水性化合物が考えられる。 As the causative substance of urine odor, first, basic compounds such as "ammonia and amines" generated by decomposition of urea and amino acids and medium molecular size hydrophobic compounds such as "phenols" can be considered.
　従来の吸水性樹脂、中でも衛生材料用途として好適なポリアクリル酸（塩）系吸水性樹脂は、酸基を有するため上記塩基性化合物に対する吸着性能を有しているが、実際に尿を吸収させた膨潤ゲルの消臭効果は不十分であった（比較例１）。また、中程度分子サイズの疎水性化合物に対しては、親水性の樹脂であるため、上記塩基性化合物への消臭効果と比較して消臭効果は弱いものと考えられる。 Conventional water-absorbent resins, especially polyacrylic acid (salt) -based water-absorbent resins suitable for use as sanitary materials, have an acid group and thus have adsorption performance for the above basic compounds, but actually absorb urine. The deodorizing effect of the swollen gel was insufficient (Comparative Example 1). Further, since it is a hydrophilic resin for a hydrophobic compound having a medium molecular size, it is considered that the deodorizing effect is weaker than the deodorizing effect for the basic compound.
　一方、上述のとおり、本発明においては、吸水性樹脂組成物が、疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分を含む。 On the other hand, as described above, in the present invention, the water-absorbent resin composition contains at least one component of the hydrophobic porous polymer adsorbent and the resin having a nitrogen-containing heterocycle.
　この（非水溶性の）疎水性多孔質ポリマー吸着剤が、中程度の分子サイズの疎水性化合物の吸着し、消臭効果を発現することに有効と考えられる。より具体的には、疎水性多孔質ポリマー吸着剤が、中程度の分子サイズの疎水性化合物（例えば、フェノール、クレゾール、フェニル酢酸）等を効率的に吸着し、尿臭の低減の効果を奏すると考えられる。ただし、後述するように、疎水性多孔質ポリマー吸着剤を使用し、かつ、スパン値を特定値以下に調整しなければ、より優れた消臭能を有さないメカニズムは不明である。 It is considered that this (water-insoluble) hydrophobic porous polymer adsorbent is effective in adsorbing a hydrophobic compound having a medium molecular size and exhibiting a deodorizing effect. More specifically, the hydrophobic porous polymer adsorbent efficiently adsorbs hydrophobic compounds of medium molecular size (eg, phenol, cresol, phenylacetic acid) and the like, and has the effect of reducing urine odor. It is thought that. However, as will be described later, a mechanism that does not have a better deodorizing ability is unknown unless a hydrophobic porous polymer adsorbent is used and the span value is adjusted to a specific value or less.
　また、上述のとおり、本発明の一実施形態においては、吸水性樹脂組成物が、含窒素複素環を有する樹脂を含む。ここで、含窒素複素環は、典型的には、アンモニア等と同様に塩基性であるため、尿に由来する塩基性物質に対する高い吸着性能を有していないと考えられる。しかしながら、このような塩基性の含窒素複素環を有する樹脂を添加することによって、より優れた消臭能を有したのは驚くべき結果であった。このような結果をもたらすメカニズムは不明であり、言い換えれば、当業者にも予期できない進歩性のある発明であると言える。さらに、本発明の一実施形態においては、吸水性樹脂組成物が、疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の両方を含む。上記両方の化合物を含むことで、さらなる消臭効果の相乗効果が期待できる。 Further, as described above, in one embodiment of the present invention, the water-absorbent resin composition contains a resin having a nitrogen-containing heterocycle. Here, since the nitrogen-containing heterocycle is typically basic like ammonia and the like, it is considered that it does not have high adsorption performance for basic substances derived from urine. However, it was a surprising result that the resin having such a basic nitrogen-containing heterocycle had a better deodorizing ability. The mechanism that produces such a result is unknown, in other words, it can be said that the invention has an inventive step that is unpredictable to those skilled in the art. Further, in one embodiment of the invention, the water-absorbent resin composition comprises both a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle. By including both of the above compounds, a synergistic effect of further deodorizing effect can be expected.
　また、本発明の一実施形態において、疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分の添加量（併用される場合は、その合計の添加量；水分散の形態・水溶液の形態では固形分換算の添加量）としては、尿臭抑制効果の観点から、吸水性樹脂１００質量部に対し、０．０５～１０質量部が好ましく、より好ましくは０．１～８質量部であり、さらに好ましくは０．１５～５質量部であり、特に好ましくは０．２～３質量部である。かような好ましい添加量は、吸水性樹脂組成物中における好ましい含有量と、含窒素複素環が開環するような処理（例えば、高温での加熱）が施されない限り一致する。すなわち、本発明の一実施形態によれば、吸水性樹脂組成物中において、疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分の含有量（併用される場合は、その合計の含有量；水分散の形態・水溶液の形態では固形分換算の添加量）は、吸水性樹脂１００質量部に対し、０．０５～１０質量部が好ましく、より好ましくは０．１～８質量部であり、さらに好ましくは０．１５～５質量部であり、特に好ましくは０．２～３質量部である。 Further, in one embodiment of the present invention, the addition amount of at least one component of the hydrophobic porous polymer adsorbent and the resin having a nitrogen-containing heterocycle (when used in combination, the total addition amount; the form of water dispersion). -In the form of an aqueous solution, the amount added in terms of solid content) is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 8 parts by mass with respect to 100 parts by mass of the water-absorbent resin, from the viewpoint of the effect of suppressing urine odor. It is by mass, more preferably 0.15 to 5 parts by mass, and particularly preferably 0.2 to 3 parts by mass. Such a preferable addition amount is the same as the preferable content in the water-absorbent resin composition unless a treatment for opening the nitrogen-containing heterocycle (for example, heating at a high temperature) is performed. That is, according to one embodiment of the present invention, the content of at least one component of the hydrophobic porous polymer adsorbent and the resin having a nitrogen-containing heterocycle in the water-absorbent resin composition (when used in combination). The total content (addition amount in terms of solid content in the form of water dispersion / aqueous solution) is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the water-absorbent resin. It is 8 parts by mass, more preferably 0.15 to 5 parts by mass, and particularly preferably 0.2 to 3 parts by mass.
　（疎水性多孔質ポリマー吸着剤）
　本発明の一実施形態において、疎水性多孔質ポリマー吸着剤が、天然由来ではない疎水性多孔質ポリマー吸着剤である（つまり、合成吸着剤である）。 (Hydrophobic porous polymer adsorbent)
In one embodiment of the invention, the hydrophobic porous polymer adsorbent is a non-naturally occurring hydrophobic porous polymer adsorbent (ie, a synthetic adsorbent).
　本発明の一実施形態において、表面架橋された吸水性樹脂と、疎水性多孔質ポリマー吸着剤とを混合する方法にも特に制限はない。例えば、表面架橋される前のベースポリマーに疎水性多孔質ポリマー吸着剤を添加してからベースポリマーを表面架橋してもよいが、疎水性多孔質ポリマー吸着剤の消臭効果を高めるためには、表面架橋された吸水性樹脂に疎水性多孔質ポリマー吸着剤を添加するのが好ましい。その意味で、疎水性多孔質ポリマー吸着剤は、表面架橋工程において添加されない方がよい。 In one embodiment of the present invention, there is no particular limitation on the method of mixing the surface-crosslinked water-absorbent resin and the hydrophobic porous polymer adsorbent. For example, the base polymer may be surface-crosslinked after adding a hydrophobic porous polymer adsorbent to the base polymer before surface cross-linking, but in order to enhance the deodorizing effect of the hydrophobic porous polymer adsorbent, It is preferable to add a hydrophobic porous polymer adsorbent to the surface-crosslinked water-absorbent resin. In that sense, the hydrophobic porous polymer adsorbent should not be added in the surface cross-linking step.
　本発明の一実施形態において、疎水性多孔質ポリマー吸着剤は、疎水性で、かつ、２０～１２００Åの平均細孔直径を有するポリマーである。かかる実施形態であることによって、フェノール、クレゾール、フェニル酢酸等の尿臭原因物質を効率的に吸着することができると考えられる。 In one embodiment of the present invention, the hydrophobic porous polymer adsorbent is a polymer that is hydrophobic and has an average pore diameter of 20 to 1200 Å. It is considered that such an embodiment can efficiently adsorb urine odor-causing substances such as phenol, cresol, and phenylacetic acid.
　なお、本明細書中、疎水性多孔質ポリマー吸着剤における「疎水性のポリマー」とは、水に対する親和性の低いポリマーであり、例えば水に対する静的接触角を測定した場合に、接触角が９０°以上となるポリマーを意味する。 In the present specification, the "hydrophobic polymer" in the hydrophobic porous polymer adsorbent is a polymer having a low affinity for water, and the contact angle is, for example, when the static contact angle with water is measured. It means a polymer having a temperature of 90 ° or higher.
　本発明の一実施形態において、疎水性多孔質ポリマー吸着剤は、疎水性の組成を有するという観点から、疎水性の非架橋性モノマー、架橋性モノマー等を共重合して得られる多孔質ポリマーがよい。疎水性の非架橋性モノマーとしては、例えば、スチレン、メチルスチレン、ビニルナフタレン、ビニルピリジン、フェニル（メタ）アクリレート、ベンジル（メタ）アクリレートのようなモノビニル芳香族系モノマー；酢酸ビニル、プロピオン酸ビニルのような、カルボン酸ビニル系モノマー；エチル（メタ）アクリレート、プロピル（メタ）アクリレートのような（メタ）アクリル酸脂肪族エステルなどが挙げられる。 In one embodiment of the present invention, the hydrophobic porous polymer adsorbent is a porous polymer obtained by copolymerizing a hydrophobic non-crosslinkable monomer, a crosslinkable monomer and the like from the viewpoint of having a hydrophobic composition. good. Examples of the hydrophobic non-crosslinkable monomer include monovinyl aromatic monomers such as styrene, methylstyrene, vinylnaphthalene, vinylpyridine, phenyl (meth) acrylate, and benzyl (meth) acrylate; vinyl acetate and vinyl propionate. Such as vinyl carboxylate monomers; ethyl (meth) acrylates, (meth) acrylic acid aliphatic esters such as propyl (meth) acrylates and the like can be mentioned.
　これに対し、一般的に吸着剤として知られているゼオライト等の無機系吸着剤（例えば、ゼオライト等）は極性が高く、平均細孔直径も２０Å未満と小さいために、臭気原因物質の吸着能が不十分であり、その結果として消臭性も不十分である。 On the other hand, inorganic adsorbents such as zeolite (for example, zeolite), which are generally known as adsorbents, have high polarity and a small average pore diameter of less than 20 Å, so that they have the ability to adsorb odor-causing substances. Is insufficient, and as a result, the deodorant property is also insufficient.
　疎水性の架橋性モノマーとしては、ジビニルベンゼン、ジビニルトルエン、ジビニルナフタレンなどの２個以上のビニル基を有する芳香族系モノマー；エチレングリコールジ（メタ）アクリレート、ポリエチレングリコールジ（メタ）アクリレート、プロピレングリコールジ（メタ）アクリレート、ポリプロピレングリコールジ（メタ）アクリレートのようなジ（メタ）アクリレート類；トリメチロールプロパントリ（メタ）アクリレート、テトラメチロールメタントリ（メタ）アクリレート、ペンタエリスリトールテトラキス（メタ）アクリレートのような（メタ）アクリル酸の多価アルコールエステルなどが挙げられる。 Examples of the hydrophobic crosslinkable monomer include aromatic monomers having two or more vinyl groups such as divinylbenzene, divinyltoluene, and divinylnaphthalene; ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and propylene glycol. Di (meth) acrylates such as di (meth) acrylates, polypropylene glycol di (meth) acrylates; trimethylolpropane tri (meth) acrylates, tetramethylolmethanetri (meth) acrylates, pentaerythritol tetrakis (meth) acrylates. Examples include polyhydric alcohol esters of na (meth) acrylic acid.
　本発明の一実施形態において、吸水性樹脂組成物における、疎水性多孔質ポリマー吸着剤の平均細孔直径としては、尿臭低減の観点から、２０～１２００Åであることが好ましく、５０～１０００Åであることがより好ましく、６０～９５０Åであることがさらに好ましく、７０～８００Åであることがよりさらに好ましく、８０～７５０Åであることがよりさらに好ましく、９０～７３０Åであることがよりさらに好ましい。かような平均細孔直径の範囲とすることによってフェノール、クレゾール、フェニル酢酸等の尿臭原因物質などを効率的に吸着することができると考えられる。また、本発明の実施形態によると、吸水性樹脂組成物における、疎水性多孔質ポリマー吸着剤の平均細孔直径は、１００Åを超えてもよく、例えば、１５０Å以上、２００Å以上、２５０Å以上であってもよい。本発明の実施形態によると、吸水性樹脂組成物において、疎水性多孔質ポリマー吸着剤の平均細孔直径が、１００Åを超えて９００Å以下であってもよい。このように本発明の実施形態の疎水性多孔質ポリマー吸着剤は、比較的疎水性で、その細孔サイズも数十～数百Åに及ぶ大きさであってもよい。 In one embodiment of the present invention, the average pore diameter of the hydrophobic porous polymer adsorbent in the water-absorbent resin composition is preferably 20 to 1200 Å, preferably 50 to 1000 Å, from the viewpoint of reducing urine odor. It is more preferably 60 to 950 Å, even more preferably 70 to 800 Å, even more preferably 80 to 750 Å, and even more preferably 90 to 730 Å. It is considered that urine odor-causing substances such as phenol, cresol, and phenylacetic acid can be efficiently adsorbed by setting the average pore diameter within the range. Further, according to the embodiment of the present invention, the average pore diameter of the hydrophobic porous polymer adsorbent in the water-absorbent resin composition may exceed 100 Å, for example, 150 Å or more, 200 Å or more, 250 Å or more. You may. According to the embodiment of the present invention, in the water-absorbent resin composition, the average pore diameter of the hydrophobic porous polymer adsorbent may be more than 100 Å and 900 Å or less. As described above, the hydrophobic porous polymer adsorbent according to the embodiment of the present invention is relatively hydrophobic, and its pore size may be several tens to several hundreds of Å.
　なお、疎水性多孔質ポリマー吸着剤の平均細孔直径は、以下のようにして求めることができる。 The average pore diameter of the hydrophobic porous polymer adsorbent can be obtained as follows.
　［ＢＥＴ比表面積］
　試料を、１８０℃で２時間真空乾燥の後、高精度ガス／蒸気吸着量測定装置（ＢＥＬＳＯＲＰ－ｍａｘ／日本ベル株式会社）を用い、液体窒素の沸点（－１９５．８℃）における窒素ガスの吸着量を相対圧０．０２～１．００の範囲で徐々に高めながら複数点測定し、上記試料の窒素吸着等温線を作成する。次に、相対圧０．０２～１．００での結果をＢＥＴプロットし、重量当たりのＢＥＴ比表面積（ｍ２／ｇ）（Ｓ）を求める。 [BET specific surface area]
After vacuum-drying the sample at 180 ° C for 2 hours, a high-precision gas / vapor adsorption amount measuring device (BELSORP-max / Nippon Bell Co., Ltd.) was used to control the nitrogen gas at the boiling point of liquid nitrogen (-195.8 ° C). The nitrogen adsorption isotherm of the above sample is prepared by measuring at a plurality of points while gradually increasing the adsorption amount in the range of relative pressure 0.02 to 1.00. Next, the results at relative pressures of 0.02 to 1.00 are BET plotted to obtain the BET specific surface area (m 2 / g) (S) per weight.
　［平均細孔直径］
　試料を、１８０℃で２時間真空乾燥の後、高精度ガス／蒸気吸着量測定装置（ＢＥＬＳＯＲＰ－ｍａｘ／日本ベル株式会社）を用い、液体窒素の沸点（－１９５．８℃）における窒素ガスの吸着量を相対圧０．０２～１．００の範囲で徐々に高めながら複数点測定し、上記試料の窒素吸着等温線を作成する。この窒素吸着等温線から、試料の細孔容積（ｍＬ／ｇ）（Ｖ）を求め、下記式より多項質体の平均細孔直径（Ｄ）を算出する。 [Average pore diameter]
After vacuum-drying the sample at 180 ° C for 2 hours, a high-precision gas / vapor adsorption amount measuring device (BELSORP-max / Nippon Bell Co., Ltd.) was used to control the nitrogen gas at the boiling point of liquid nitrogen (-195.8 ° C). The nitrogen adsorption isotherm of the above sample is prepared by measuring at a plurality of points while gradually increasing the adsorption amount in the range of relative pressure 0.02 to 1.00. From this nitrogen adsorption isotherm, the pore volume (mL / g) (V) of the sample is obtained, and the average pore diameter (D) of the multinomial body is calculated from the following formula.
　Ｄ＝４×Ｖ／Ｓ×１０４
（Ｖ：細孔容積（ｍＬ／ｇ）、Ｓ：ＢＥＴ比表面積（ｍ２／ｇ））
　また、本発明の一実施形態において、吸水性樹脂組成物における、疎水性多孔質ポリマー吸着剤のＢＥＴ比表面積としては、尿臭低減の観点から、２０～２０００ｍ２／ｇであることが好ましく、さらに好ましい順に、５０～２０００ｍ２／ｇ、７０～１２００ｍ２／ｇ、８０～１０００ｍ２／ｇ、９０～９００ｍ２／ｇ、１００～８５０ｍ２／ｇである。 D = 4 × V / S × 10 4
(V: pore volume (mL / g), S: BET specific surface area (m 2 / g))
Further, in one embodiment of the present invention, the BET specific surface area of the hydrophobic porous polymer adsorbent in the water-absorbent resin composition is preferably 20 to 2000 m 2 / g from the viewpoint of reducing urine odor. More preferably, they are 50 to 2000 m 2 / g, 70 to 1200 m 2 / g, 80 to 1000 m 2 / g, 90 to 900 m 2 / g, and 100 to 850 m 2 / g.
　また、本発明の一実施形態において、吸水性樹脂組成物における、疎水性多孔質ポリマー吸着剤の平均粒子径としては、吸水性樹脂との混合性の観点から、１～２０００μｍであることが好ましく、１０～１５００μｍであることがより好ましく、５０～１０００μｍであることがさらに好ましく、６０～８００μｍであることがよりさらに好ましい。なお、疎水性多孔質ポリマー吸着剤の平均粒子径は、走査型電子顕微鏡（株式会社キーエンス製；ＶＦ－９８００）を用いて拡大倍率５０～５００倍で撮影し、画像解析ソフトを使用し、撮影された画像の中から２０点をサンプルとしてランダム選択してその粒子径を測定することにより求める。 Further, in one embodiment of the present invention, the average particle size of the hydrophobic porous polymer adsorbent in the water-absorbent resin composition is preferably 1 to 2000 μm from the viewpoint of mixing with the water-absorbent resin. It is more preferably 10 to 1500 μm, further preferably 50 to 1000 μm, and even more preferably 60 to 800 μm. The average particle size of the hydrophobic porous polymer adsorbent was photographed using a scanning electron microscope (manufactured by Keyence Co., Ltd .; VF-9800) at a magnification of 50 to 500 times, and photographed using image analysis software. Twenty points are randomly selected as a sample from the images obtained and the particle size is measured.
　また、本発明の一実施形態において、疎水性多孔質ポリマー吸着剤の添加量としては、尿臭抑制効果の観点から、吸水性樹脂１００質量部に対し、０．０５～１０質量部が好ましく、より好ましくは０．１～８質量部であり、さらに好ましくは０．１５～５質量部であり、特に好ましくは０．２～３質量部であり、０．３質量部以上、０．４質量部以上、０．５質量部以上、０．５質量部超、あるいは、０．７質量部以上も好ましい。かような好ましい添加量は、吸水性樹脂組成物中における好ましい含有量と一致する。 Further, in one embodiment of the present invention, the amount of the hydrophobic porous polymer adsorbent added is preferably 0.05 to 10 parts by mass with respect to 100 parts by mass of the water-absorbent resin from the viewpoint of the effect of suppressing urine odor. It is more preferably 0.1 to 8 parts by mass, further preferably 0.15 to 5 parts by mass, particularly preferably 0.2 to 3 parts by mass, and 0.3 parts by mass or more, 0.4 mass by mass. More than parts, 0.5 parts by mass or more, more than 0.5 parts by mass, or 0.7 parts by mass or more are also preferable. Such a preferable addition amount is consistent with a preferable content in the water-absorbent resin composition.
　すなわち、本発明の一実施形態によれば、吸水性樹脂組成物中において、疎水性多孔質ポリマー吸着剤の含有量は、吸水性樹脂１００質量部に対し、０．０５～１０質量部が好ましく、より好ましくは０．１～８質量部であり、さらに好ましくは０．１５～５質量部であり、特に好ましくは０．２～３質量部であり、０．３質量部以上、０．４質量部以上、０．５質量部以上、０．５質量部超、あるいは、０．７質量部以上も好ましい。含有量が好ましい添加量より少ない場合には、尿臭抑制効果が十分に得られないおそれがある。また、含有量が好ましい添加量より多い場合には、吸水性樹脂の吸水倍率が低下するおそれがある。 That is, according to one embodiment of the present invention, the content of the hydrophobic porous polymer adsorbent in the water-absorbent resin composition is preferably 0.05 to 10 parts by mass with respect to 100 parts by mass of the water-absorbent resin. , More preferably 0.1 to 8 parts by mass, further preferably 0.15 to 5 parts by mass, particularly preferably 0.2 to 3 parts by mass, 0.3 parts by mass or more, 0.4 parts by mass. By mass or more, 0.5 parts by mass or more, more than 0.5 parts by mass, or 0.7 parts by mass or more is also preferable. If the content is less than the preferable addition amount, the urine odor suppressing effect may not be sufficiently obtained. Further, when the content is larger than the preferable addition amount, the water absorption ratio of the water-absorbent resin may decrease.
　本発明の一実施形態において、疎水性多孔質ポリマー吸着剤の具体的としては、ピュロライト株式会社製：Ｃｈｒｏｍａｌｉｔｅ　ＡＤシリーズ、Ｃｈｒｏｍａｌｉｔｅ　ＰＣＧシリーズ、Ｐｕｒｏｓｏｒｂ　ＰＡＤシリーズ等のスチレン系、メタクリル酸エステル系合成吸着剤；三菱ケミカル社製：ダイヤイオンＨＰシリーズ、ダイヤイオンＨＰ２ＭＧＬ等のスチレン系または（メタ）アクリル系合成吸着剤；オルガノ株式会社製：アンバーライトＸＡＤシリーズ、アンバーライトＦＰＸシリーズ等のスチレン系、または（メタ）アクリル系合成吸着剤；特開２０１７－１４０３３２号公報等に記載のフェニル基を有する多孔ポリマーなどが挙げられる。 In one embodiment of the present invention, specific examples of the hydrophobic porous polymer adsorbent include styrene-based and methacrylic acid ester-based synthetic adsorbents manufactured by Purolite Co., Ltd .: Chromalite AD series, Chromalite PCG series, Purosorb PAD series and the like; Mitsubishi Chemical Co., Ltd .: Styrene-based or (meth) acrylic synthetic adsorbents such as Diaion HP series and Diaion HP2MGL; Organo Co., Ltd .: Styrene-based or (meth) such as Amberlite XAD series and Amberlite FPX series. Acrylic synthetic adsorbents; examples thereof include porous polymers having a phenyl group described in JP-A-2017-140332.
　本発明の一実施形態において、疎水性多孔質ポリマー吸着剤は１種でも２種以上組み合わせて使用されてもよい。 In one embodiment of the present invention, the hydrophobic porous polymer adsorbent may be used alone or in combination of two or more.
　＜吸水性樹脂１ｇあたりの総比表面積＞
　吸水性樹脂１ｇあたりの疎水性多孔質ポリマー吸着剤の総比表面積とは、吸水性樹脂単位量あたりに添加される、疎水性多孔質ポリマー吸着剤の比表面積総量のことであり、下記式により求めることができる。 <Total specific surface area per 1 g of water-absorbent resin>
The total specific surface area of the hydrophobic porous polymer adsorbent per 1 g of the water-absorbent resin is the total specific surface area of the hydrophobic porous polymer adsorbent added per unit amount of the water-absorbent resin, and is calculated by the following formula. Can be asked.
Figure JPOXMLDOC01-appb-M000006
Figure JPOXMLDOC01-appb-M000006
　吸水性樹脂１ｇあたりの総比表面積としては、尿臭抑制の観点から、０．２ｍ２以上が好ましく、より好ましくは０．３ｍ２以上、さらに好ましくは０．４ｍ２以上である。上限としても特に制限はないが、経済性の観点から、例えば、１００ｍ２以下が好ましい。無論、かような吸水性樹脂１ｇあたりの好ましい総比表面積は、吸水性樹脂組成物中における好ましい総比表面積と一致する。すなわち、本発明の一実施形態によれば、吸水性樹脂組成物において、吸水性樹脂１ｇあたりの総比表面積としては、尿臭抑制の観点から、０．２ｍ２以上が好ましく、より好ましくは０．３ｍ２以上、さらに好ましくは０．４ｍ２以上、また、１．０ｍ２以上、１．５ｍ２以上、２．０ｍ２以上、２．５ｍ２超、３．０ｍ２超、３．５ｍ２超、４．０ｍ２以上、４．２ｍ２以上、４．５ｍ２以上、５．０ｍ２以上、５．５ｍ２以上、あるいは、６．０ｍ２以上である。上限としても特に制限はないが、経済性の観点から、例えば、１００ｍ２以下が好ましく、５０ｍ２以下、４０ｍ２以下、３０ｍ２以下、２０ｍ２以下、あるいは、１０ｍ２以下であってもよい。 The total specific surface area per 1 g of the water-absorbent resin is preferably 0.2 m 2 or more, more preferably 0.3 m 2 or more, and further preferably 0.4 m 2 or more from the viewpoint of suppressing urine odor. The upper limit is not particularly limited, but from the viewpoint of economy, for example, 100 m 2 or less is preferable. Of course, the preferable total specific surface area per 1 g of such a water-absorbent resin is consistent with the preferable total specific surface area in the water-absorbent resin composition. That is, according to one embodiment of the present invention, in the water-absorbent resin composition, the total specific surface area per 1 g of the water-absorbent resin is preferably 0.2 m 2 or more, more preferably 0, from the viewpoint of suppressing urine odor. .3m 2 or more, more preferably 0.4m 2 or more, and 1.0m 2 or more, 1.5m 2 or more, 2.0m 2 or more, 2.5m 2 or more, 3.0m 2 or more, 3.5m 2 or more. Super 4.0m 2 or more, 4.2m 2 or more, 4.5m 2 or more, 5.0m 2 or more, 5.5m 2 or more, or 6.0m 2 or more. The upper limit is not particularly limited, but from the viewpoint of economy, for example, 100 m 2 or less is preferable, and 50 m 2 or less, 40 m 2 or less, 30 m 2 or less, 20 m 2 or less, or 10 m 2 or less may be used.
　なお、疎水性多孔質ポリマー吸着剤は、市販品を購入することによって準備してもよい。 The hydrophobic porous polymer adsorbent may be prepared by purchasing a commercially available product.
　（含窒素複素環を有する樹脂）
　本発明の一実施形態において、吸水性樹脂組成物は、含窒素複素環を有する樹脂を含む。尿臭の原因物質としては、尿素やアミノ酸の分解によって発生するアンモニアやアミン類などの塩基性化合物が考えられる。従来の吸水性樹脂、中でも衛生材料用途として好適なポリアクリル酸（塩）系吸水性樹脂は、酸基を有するため上記塩基性化合物に対する吸着性能を有しているが、実際に尿を吸収させた膨潤ゲルの消臭効果は不十分であった。ここで、含窒素複素環は、典型的には、アンモニア等と同様に塩基性であるため、尿に由来する塩基性物質に対する高い吸着性能を有していないと考えられる。しかしながら、このような塩基性の含窒素複素環を有する樹脂を添加することによって、より優れた消臭能を有したのは驚くべき結果であった。 (Resin having a nitrogen-containing heterocycle)
In one embodiment of the present invention, the water-absorbent resin composition comprises a resin having a nitrogen-containing heterocycle. As a causative substance of urine odor, basic compounds such as ammonia and amines generated by decomposition of urea and amino acids can be considered. Conventional water-absorbent resins, especially polyacrylic acid (salt) -based water-absorbent resins suitable for use as sanitary materials, have an acid group and thus have adsorption performance for the above basic compounds, but actually absorb urine. The deodorizing effect of the swollen gel was insufficient. Here, since the nitrogen-containing heterocycle is typically basic like ammonia and the like, it is considered that it does not have high adsorption performance for basic substances derived from urine. However, it was a surprising result that the resin having such a basic nitrogen-containing heterocycle had a better deodorizing ability.
　本発明の一実施形態において、含窒素複素環を有する樹脂による消臭効果を高めるためには、吸水性樹脂と、含窒素複素環を有する樹脂とを混合する方法として、表面架橋された吸水性樹脂に含窒素複素環を有する樹脂を添加するのが好ましい。表面架橋される前のベースポリマーに含窒素複素環を有する樹脂を混合すると、その後の表面架橋時の加熱処理によってベースポリマーと含窒素複素環を有する樹脂とが架橋反応を起こしてしまい消臭効果が消失する可能性がある。より具体的に、例えば含窒素複素環を有する樹脂としてオキサゾリン基含有重合体を使用すると、架橋時の熱によってオキサゾリン環が開環する。そうすると、その残基が吸水性樹脂を構成する構成単位の官能基と相互作用し架橋反応を起こしてしまう。ゆえに、消臭作用を発現するために必要と考えられる特定の官能基（含窒素複素環）がなくなり、消臭効果が消失する可能性がある。換言すれば、オキサゾリン基等を有する化合物を架橋剤として吸水性樹脂に使用する例は従来知られているが、かような例であると架橋反応し含窒素複素環が存在しなくなるため、本願の様な消臭効果は得られない。その意味で、含窒素複素環を有する樹脂は、表面架橋工程において添加されない方がよい。よって、本発明の一実施形態によれば、吸水性樹脂組成物の製造方法において、架橋剤としての機能を有する含窒素複素環を有する樹脂の添加がなされた後は、高い温度での加熱工程を施さないことが好ましい。よって加熱工程を施すとしても、その温度は、１００℃未満、９０℃以下、８０℃以下、７０℃以下、あるいは、６５℃以下である。 In one embodiment of the present invention, in order to enhance the deodorizing effect of the resin having a nitrogen-containing heterocycle, a surface-crosslinked water-absorbing resin is used as a method of mixing the water-absorbent resin and the resin having a nitrogen-containing heterocycle. It is preferable to add a resin having a nitrogen-containing heterocycle to the resin. When a resin having a nitrogen-containing heterocycle is mixed with the base polymer before surface cross-linking, the base polymer and the resin having a nitrogen-containing heterocycle undergo a cross-linking reaction due to the subsequent heat treatment at the time of surface cross-linking, which has a deodorizing effect. May disappear. More specifically, for example, when an oxazoline group-containing polymer is used as a resin having a nitrogen-containing heterocycle, the oxazoline ring is opened by the heat at the time of crosslinking. Then, the residue interacts with the functional group of the constituent unit constituting the water-absorbent resin to cause a cross-linking reaction. Therefore, there is a possibility that the specific functional group (nitrogen-containing heterocycle) necessary for exhibiting the deodorizing action disappears and the deodorizing effect disappears. In other words, an example of using a compound having an oxazoline group or the like as a cross-linking agent in a water-absorbent resin has been conventionally known, but in such an example, a cross-linking reaction occurs and a nitrogen-containing heterocycle does not exist. The deodorizing effect like that cannot be obtained. In that sense, the resin having a nitrogen-containing heterocycle should not be added in the surface cross-linking step. Therefore, according to one embodiment of the present invention, in the method for producing a water-absorbent resin composition, after the resin having a nitrogen-containing heterocycle having a function as a cross-linking agent is added, a heating step at a high temperature is performed. It is preferable not to apply. Therefore, even if the heating step is performed, the temperature is less than 100 ° C., 90 ° C. or lower, 80 ° C. or lower, 70 ° C. or lower, or 65 ° C. or lower.
　本発明の一実施形態によれば、前記含窒素複素環を有する樹脂が水不溶性またはＬｏｇＰが１．５以上の水に分散可能なポリマーである。つまり、含窒素複素環を有する樹脂を水分散の形態で、吸水性樹脂に添加する。本発明の一実施形態によれば、含窒素複素環を有する樹脂を何らかの分散媒に分散させない形態で、つまりドライの形態で、吸水性樹脂に添加する。 According to one embodiment of the present invention, the resin having the nitrogen-containing heterocycle is a polymer that is water-insoluble or can be dispersed in water having a LogP of 1.5 or more. That is, the resin having a nitrogen-containing heterocycle is added to the water-absorbent resin in the form of water dispersion. According to one embodiment of the present invention, the resin having a nitrogen-containing heterocycle is added to the water-absorbent resin in a form in which the resin has no dispersion in some dispersion medium, that is, in a dry form.
　本願におけるＬｏｇＰとは、ｎ－オクタノール／水分配係数（Ｌｏｇ１０Ｐｏｗ）を指し、ＯＥＣＤ　Ｔｅｓｔ　Ｇｕｉｄｅｌｉｎｅ（ＯＥＣＤ理事会決定「Ｃ（８１）３０最終別添１」）１０７又は日本工業規格Ｚ７２６０－１０７（２０００）「分配係数（１－オクタノール／水）の測定－フラスコ振とう法」によって求めてもよいが、本発明では原則下記の計算法で求める値を用いる。 LogP in the present application refers to the n-octanol / water partition coefficient (Log10Pow), and is referred to as OECD Test Guideline (OECD Board Decision "C (81) 30 Final Attachment 1") 107 or Japanese Industrial Standard Z7260-107 (2000). It may be obtained by "measurement of partition coefficient (1-octanol / water) -flask shaking method", but in the present invention, the value obtained by the following calculation method is used in principle.
　尚、下記ＶＭＬｏｇＰ（ｉ）及びＭＳＬｏｇＰ（ｉ）の値は、Ａｄｖａｎｃｅｄ　Ｃｈｅｍｉｓｔｒｙ　Ｄｅｖｅｌｏｐｍｅｎｔ製のＡＣＤ／ＬｏｇＰ　ＤＢ　Ｒｅｌｅａｃｅ　１００　Ｐｒｏｄｕｃｔ　Ｖｅｒｓｉｏｎ　１０．０１により温度２５℃条件下で算出される値を用いる。また、特に断りがない限り、ＬｏｇＰは１０を底とする、いわゆる常用対数値である。 The values of VMLogP (i) and MSLogP (i) below are calculated by ACD / LogP DB Release 100 Product Version 10.01 manufactured by Advanced Chemistry Development under the condition of 25 ° C. Unless otherwise specified, LogP is a so-called common logarithmic value having a base of 10.
　まず、各モノマー（ｉ）（ｉは各モノマーを識別するための１から始まる連番）の重合反応部位に、メチル基を付与した仮想モノマー単位（Ｖｉｒｔｕａｌ　Ｍｏｎｏｍｅｒ）のＬｏｇＰ（ＶＭＬｏｇＰ（ｉ）：ｉは前記と同じ）を算出する。 First, LogP (VMLogP (i): i) of a virtual monomer unit (Virtual Monomer) in which a methyl group is added to a polymerization reaction site of each monomer (i) (i is a serial number starting from 1 for identifying each monomer). Is the same as above).
　仮想モノマー単位はポリマー中の繰返し構造を基準とするものであり、ポリマーの製造で実際に用いられたモノマーとは一致しない場合がある。具体的には以下の様にして定める。 The virtual monomer unit is based on the repeating structure in the polymer, and may not match the monomer actually used in the production of the polymer. Specifically, it is determined as follows.
　モノマーが重合性不飽和単量体の場合、重合反応部位はＣ＝Ｃであり、不飽和結合に２つのメチル基を導入する。 When the monomer is a polymerizable unsaturated monomer, the polymerization reaction site is C = C, and two methyl groups are introduced into the unsaturated bond.
　モノマーが開環重合性単量体の場合、環状構造の開環単位（例えばエチレンオキサイドであれば、エポキシ基）に、２つのメチル基を導入する。 When the monomer is a ring-opening polymerizable monomer, two methyl groups are introduced into the ring-opening unit of the cyclic structure (for example, an epoxy group in the case of ethylene oxide).
　モノマーが縮重合性単量体の場合、縮重合単位（例えばエステル、エーテル、アミド）にメチル基を導入する。 When the monomer is a polycondensable monomer, a methyl group is introduced into the polycondensation unit (for example, ester, ether, amide).
　なお、モノマーがセルロース骨格の繰り返し単位を有する場合、個々のポリエーテル単位を縮重合単位としてメチル基を導入すればよい。また、高分子不飽和単量体、例えば不飽和基を有するポリアルキレンオキサイド（例えば、メトキシポリエチレングリコールのモノアクリレート）の場合、不飽和結合（例えばアクリル酸のＣ＝Ｃ）に２つのメチル基を導入すると同時に、単量体中の高分子単位（例えばポリエチレンオキサイド）も分解してメチル基を導入し、さらに縮重合単位（例えばアクリル酸のＣＯＯＨ）もメチル化すればよい。 When the monomer has a repeating unit of a cellulose skeleton, a methyl group may be introduced using each polyether unit as a polycondensation unit. Further, in the case of a polymer unsaturated monomer, for example, a polyalkylene oxide having an unsaturated group (for example, a monoacrylate of methoxypolyethylene glycol), two methyl groups are attached to an unsaturated bond (for example, C = C of acrylic acid). At the same time as the introduction, the polymer unit (for example, polyethylene oxide) in the monomer may be decomposed to introduce a methyl group, and the decomposable unit (for example, COOH of acrylic acid) may also be methylated.
　例えば、不飽和単量体の重合によるポリマーとして、ポリエチレンの場合には、モノマー（１）はエチレンとなり、ＶＭＬｏｇＰ（１）はｎ－ブタンのＬｏｇＰとなる。また、スチレン－ブタジエン共重合体の場合には、モノマー（１）をスチレン、モノマー（２）をブタジエンとし、ＶＭＬｏｇＰ（１）は２－フェニルブタンのＬｏｇＰとなり、ＶＭＬｏｇＰ（２）は３－ヘキセンのＬｏｇＰとなる。また、１００％鹸化ポリビニルアルコールの場合は、ＶＭＬｏｇＰ（１）は３－ブタノールのＬｏｇＰとなる。 For example, in the case of polyethylene as a polymer obtained by polymerizing an unsaturated monomer, the monomer (1) becomes ethylene and the VMLogP (1) becomes LogP of n-butane. In the case of a styrene-butadiene copolymer, the monomer (1) is styrene, the monomer (2) is butadiene, VMLogP (1) is LogP of 2-phenylbutane, and VMLogP (2) is 3-hexene. It becomes LogP. Further, in the case of 100% saponified polyvinyl alcohol, VMLogP (1) becomes LogP of 3-butanol.
　また、開環重合性単量体の重合によるポリマーとして、ポリエチレングリコールの場合には、モノマー（１）をエチレンオキサイドとし、ＶＭＬｏｇＰ（１）はメチル－ｎ－プロピルエーテルのＬｏｇＰとなる。 Further, as the polymer obtained by polymerizing the ring-opening polymerizable monomer, in the case of polyethylene glycol, the monomer (1) is ethylene oxide, and VMLogP (1) is LogP of methyl-n-propyl ether.
　また、縮重合性単量体の重合によるポリマーとして、ポリアスパラギン酸の場合、モノマー（２）をアスパラギン酸として、ＶＭＬｏｇＰ（１）はＮ－メチル－メチルアスパラギン酸エステルのＬｏｇＰとなる。 Further, in the case of polyaspartic acid as a polymer by polymerizing a polycondensable monomer, the monomer (2) becomes aspartic acid and VMLogP (1) becomes LogP of N-methyl-methylaspartic acid ester.
　次に、ＬｏｇＰを求めるポリマーを構成する各モノマーのモル比率（Ｍｏｌ　Ｒａｔｉｏ）（ＭＲ（ｉ）：ｉは前記と同じ）で前記ＶＭＬｏｇＰ（ｉ）を補正する（ＶＭＬｏｇＰ（ｉ）×ＭＲ（ｉ））。尚、該ポリマーを構成していないモノマー（ｊ）のＭＲ（ｊ）は０であり、ホモポリマーであればＭＲ（ｉ）は１である。 Next, the VMLogP (i) is corrected by the molar ratio (MolRatio) (MR (i): i is the same as above) of each monomer constituting the polymer for which LogP is obtained (VMLogP (i) × MR (i). ). The MR (j) of the monomer (j) that does not constitute the polymer is 0, and if it is a homopolymer, the MR (i) is 1.
　最後に、全モノマーの前記補正値を合計することで、ＬｏｇＰが求まる（下記式１）。　　　 Finally, LogP can be obtained by summing the correction values of all the monomers (formula 1 below). It was
Figure JPOXMLDOC01-appb-M000007
Figure JPOXMLDOC01-appb-M000007
（式１中、ＶＭＬｏｇＰ（ｉ）は、ポリマー繰り返し単位（ｉ）の両端をメチル化した仮想モノマー単位（Ｖｉｒｔｕａｌ　Ｍｏｎｏｍｅｒ（ＶＭ））の２５℃での“ｎ－オクタノール－水分配係数”の計算値であり、ＭＲ（ｉ）は、繰り返し単位（ｉ）の“モル比率（Ｍｏｌ　Ｒａｔｉｏ（ＭＲ）”）である。）
　前記ＬｏｇＰの例としては、アクリル酸ホモポリマーは１．１２、スチレンホモポリマーは４．０９となる。 (In Formula 1, VMLogP (i) is a calculated value of "n-octanol-water partition coefficient" at 25 ° C. of a virtual monomer unit (Virtual Monomer (VM)) in which both ends of the polymer repeating unit (i) are methylated. MR (i) is the “mol ratio (MolRatio (MR)”) of the repeating unit (i).)
As an example of the LogP, the acrylic acid homopolymer is 1.12 and the styrene homopolymer is 4.09.
　このような水不溶性またはＬｏｇＰが１．５以上の水に分散可能なポリマーである含窒素複素環を有する樹脂は、その使用時、吸水性樹脂の内部に浸透しにくい。そのため、吸水性樹脂内部においての、吸水性樹脂を構成する構成単位の官能基（特にはカルボキシル基）と、消臭に有効な官能基（含窒素複素環）との相互作用を極力抑えることができる。よって、吸水性樹脂表面近傍に消臭に有効な官能基（つまり、含窒素複素環）を残存でき、尿臭原因物質に対し高い吸着効果の発揮が可能となる。ここで、本願明細書において、「水不溶性」とは、２５℃のイオン交換水に溶解する質量（溶解度）が１ｇ以下（１質量％以下）を意味する。また、「溶解」とは、光を照射した時に浮遊物または沈殿物が目視で確認できない状態を意味する。含窒素複素環を有する樹脂のＬｏｇＰは消臭効果の観点から、１．５以上が好ましく、より好ましくは２．０以上であり、さらに好ましくは３．０以上である。ＬｏｇＰの上限は例えば４．０９未満である。水不溶性またはＬｏｇＰが１．５以上の水に分散可能なポリマーであることは、すなわち、含窒素複素環を有する樹脂が粒子状であるということである。よって、本発明の一実施形態によれば、吸水性樹脂組成物において、前記含窒素複素環を有する樹脂の平均粒径が、１０～２５０，０００ｎｍであることが好ましく、３０～６００ｎｍであることがより好ましく、５０～３００ｎｍであることがさらに好ましい。ここで含窒素複素環を有する樹脂の平均粒径の測定方法は、樹脂の特性に合わせ、適切な方法で測定できる。水性分散体に含まれる粒子であれば、動的光散乱法による粒度分布測定器（Ｐａｒｔｉｃｌｅ　Ｓｉｚｉｎｇ　Ｓｙｓｔｅｍｓ社製「ＮＩＣＯＭＰ　Ｍｏｄｅｌ　３８０」）を用い、平均粒子径（体積平均粒子径）を測定できる。粉体状の粒子であれば、卓上走査電子顕微鏡（ＪＥＯＬ社製「ＪＣＭ－６０００」）を用い、５０個計測することで、平均粒子径（体積平均粒子径）を算出できる。 Such a resin having a nitrogen-containing heterocycle which is water-insoluble or a polymer dispersible in water having LogP of 1.5 or more does not easily penetrate into the water-absorbent resin when used. Therefore, it is possible to suppress the interaction between the functional group (particularly the carboxyl group) of the constituent unit constituting the water-absorbent resin and the functional group effective for deodorization (nitrogen-containing heterocycle) inside the water-absorbent resin as much as possible. can. Therefore, a functional group effective for deodorization (that is, a nitrogen-containing heterocycle) can remain in the vicinity of the surface of the water-absorbent resin, and a high adsorption effect on urine odor-causing substances can be exhibited. Here, in the present specification, "water-insoluble" means that the mass (solubility) dissolved in ion-exchanged water at 25 ° C. is 1 g or less (1% by mass or less). Further, "dissolution" means a state in which no suspended matter or precipitate can be visually confirmed when irradiated with light. From the viewpoint of deodorizing effect, the LogP of the resin having a nitrogen-containing heterocycle is preferably 1.5 or more, more preferably 2.0 or more, and further preferably 3.0 or more. The upper limit of LogP is, for example, less than 4.09. Being a water-insoluble or dispersible polymer with LogP of 1.5 or more means that the resin having a nitrogen-containing heterocycle is in the form of particles. Therefore, according to one embodiment of the present invention, in the water-absorbent resin composition, the average particle size of the resin having a nitrogen-containing heterocycle is preferably 10 to 250,000 nm, preferably 30 to 600 nm. Is more preferable, and 50 to 300 nm is even more preferable. Here, the method for measuring the average particle size of the resin having a nitrogen-containing heterocycle can be measured by an appropriate method according to the characteristics of the resin. If the particles are contained in the aqueous dispersion, the average particle size (volume average particle size) can be measured by using a particle size distribution measuring device (“NICOMP Model 380” manufactured by Partricle Sigmas Systems Co., Ltd.) by a dynamic light scattering method. For powdery particles, the average particle size (volume average particle size) can be calculated by measuring 50 particles using a desktop scanning electron microscope (“JCM-6000” manufactured by JEOL Ltd.).
　本発明の一実施形態において、含窒素複素環を有する樹脂の添加量としては、尿臭抑制効果の観点から、前記吸水性樹脂１００質量部に対し、０．０１～３０質量部が好ましく、より好ましくは０．０５～１０質量部であり、さらに好ましくは０．１～５質量部であり、よりさらに好ましくは０．２～３質量部であり、特に、０．３質量部以上、０．３質量部超、０．５質量部超、１．０質量部以上、１．０質量部超、１．５質量部以上、あるいは、２．０質量部以上がよい。かような好ましい添加量は、含窒素複素環が開環するような処理（例えば、高温での加熱）が施されない限り、吸水性樹脂組成物中における好ましい含有量と一致する。すなわち、本発明の一実施形態によれば、吸水性樹脂組成物中において、含窒素複素環を有する樹脂の含有量は、０．０１～３０質量部が好ましく、より好ましくは０．０５～１０質量部であり、さらに好ましくは０．１～５質量部であり、特に好ましくは０．２～３質量部であり、特に、０．３質量部以上、０．３質量部超、０．５質量部超、１．０質量部以上、１．０質量部超、１．５質量部以上、あるいは、２．０質量部以上がよい。 In one embodiment of the present invention, the amount of the resin having a nitrogen-containing heterocycle is preferably 0.01 to 30 parts by mass with respect to 100 parts by mass of the water-absorbent resin from the viewpoint of the effect of suppressing urine odor. It is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, still more preferably 0.2 to 3 parts by mass, and particularly 0.3 parts by mass or more, 0. More than 3 parts by mass, more than 0.5 parts by mass, 1.0 part by mass or more, more than 1.0 part by mass, 1.5 parts by mass or more, or 2.0 parts by mass or more is preferable. Such a preferable addition amount is consistent with a preferable content in the water-absorbent resin composition unless a treatment for opening the nitrogen-containing heterocycle (for example, heating at a high temperature) is performed. That is, according to one embodiment of the present invention, the content of the resin having a nitrogen-containing heterocycle in the water-absorbent resin composition is preferably 0.01 to 30 parts by mass, more preferably 0.05 to 10. It is parts by mass, more preferably 0.1 to 5 parts by mass, particularly preferably 0.2 to 3 parts by mass, and particularly 0.3 parts by mass or more, more than 0.3 parts by mass, and 0.5 parts. More than parts by mass, 1.0 part by mass or more, more than 1.0 part by mass, 1.5 parts by mass or more, or 2.0 parts by mass or more is preferable.
　本発明において、含窒素複素環という特定の構造が尿臭低減効果に寄与する。 In the present invention, a specific structure called a nitrogen-containing heterocycle contributes to the effect of reducing urine odor.
　したがって、単に含窒素複素環を有する樹脂を前記好ましい添加量にするだけでなく、上述したような加熱による含窒素複素環の開環や架橋反応を回避し、効果を発揮するのに必要な量の含窒素複素環を残存させることが必要である。ここで、本発明の吸水性樹脂組成物中に存在する含窒素複素環の含有量を「含窒素複素環の存在度」という指標で規定する。含窒素複素環の存在度とは、吸水性樹脂組成物のＦＴ－ＩＲ測定で検出される、吸水性樹脂由来のピーク高さに対する、含窒素複素環に由来するピーク高さの比を意味する。含窒素複素環の存在度は、目開き１５０μｍのＪＩＳ標準篩を通過させた吸水性樹脂組成物に対して、ＦＴ－ＩＲ（Ｔｈｅｒｍｏ　Ｆｉｓｈｅｒ　Ｓｃｉｅｎｔｉｆｉｃ社製　Ｎｉｃｏｌｅｔ　ｉＳ５０）を用いて、２５℃の環境下、ダイヤモンドＡＴＲ法、波数範囲４０００～６５０ｃｍ－１、スキャン回数６４回、分解能４ｃｍ－１の条件で、１６００～１７００ｃｍ－１に検出される含窒素複素環由来のピーク高さと、１５００～１６００ｃｍ－１に検出される吸水性樹脂組成物のカルボン酸塩のＣ＝Ｏ結合由来のピーク高さを測定し、ベースライン補正後に得られた測定値から以下の式により、含窒素複素環の存在度を算出する。 Therefore, not only the resin having the nitrogen-containing heterocycle is added in the preferable amount, but also the amount necessary for avoiding the ring-opening and cross-linking reaction of the nitrogen-containing heterocycle due to heating as described above and exerting the effect. It is necessary to retain the nitrogen-containing heterocycle of. Here, the content of the nitrogen-containing heterocycle present in the water-absorbent resin composition of the present invention is defined by an index called "absence of nitrogen-containing heterocycle". The abundance of the nitrogen-containing heterocycle means the ratio of the peak height derived from the nitrogen-containing heterocycle to the peak height derived from the water-absorbent resin detected by the FT-IR measurement of the water-absorbent resin composition. .. The abundance of the nitrogen-containing heterocycle was determined in an environment of 25 ° C. using FT-IR (Nitrolet iS50 manufactured by Thermo Fisher Scientific) for the water-absorbent resin composition passed through a JIS standard sieve having an opening of 150 μm. , Diamond ATR method, wave number range 4000-650 cm -1 , 64 scans, resolution 4 cm -1 conditions, peak height derived from nitrogen-containing heterocycle detected at 1600-1700 cm -1 and 1500-1600 cm -1 The peak height derived from the C = O bond of the carboxylate of the water-absorbent resin composition detected in is measured, and the abundance of the nitrogen-containing heterocycle is determined by the following formula from the measured value obtained after baseline correction. calculate.
　含窒素複素環の存在度（％）＝ｈ１／ｈ２×１００
　ｈ１：吸水性樹脂組成物の含窒素複素環由来のピーク高さ
　ｈ２：吸水性樹脂組成物のカルボン酸塩のＣ＝Ｏ結合由来のピーク高さ。 Absence of nitrogen-containing heterocycle (%) = h1 / h2 × 100
h1: Peak height derived from the nitrogen-containing heterocycle of the water-absorbent resin composition h2: Peak height derived from the C = O bond of the carboxylate of the water-absorbent resin composition.
　なお、存在度は同じサンプルについて５回の測定を行い、最大値と最小値を除いた３つの値の相加平均値を採用する。 The abundance is measured 5 times for the same sample, and the arithmetic mean value of 3 values excluding the maximum value and the minimum value is adopted.
　本発明の一実施形態において、含窒素複素環の存在度が、３．０％以上、４．０％以上、５．０％以上、６．０％以上、７．０％以上、８．０％以上、１０．０％以上、１２．０％以上、１３．０％以上、１４．０％以上、１５．０％以上、２０．０％以上、３０．０％以上、４０．０％以上、あるいは、４２．０％以上がよい。含窒素複素環の存在度が３．０％未満であると、尿に起因する悪臭を十分に低減できない場合がある。本発明の一実施形態において、含窒素複素環の存在度が、２００％以下、あるいは、１５０％以下である。含窒素複素環の存在度が２００％を超えると、吸水性樹脂組成物の吸収倍率が低下したり、疎水性が高すぎて吸水速度が低下したりするなどの悪影響が出る可能性がある。よって、本発明の一実施形態において、吸水性樹脂と、疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分を含み、前記スパン値が、１．１０以下である、吸水性樹脂組成物であって、前記含窒素複素環を有する樹脂を含む場合は、前記含窒素複素環の存在度が３．０％以上である、吸水性樹脂組成物が提供される。 In one embodiment of the present invention, the abundance of the nitrogen-containing heterocycle is 3.0% or more, 4.0% or more, 5.0% or more, 6.0% or more, 7.0% or more, 8.0. % Or more, 10.0% or more, 12.0% or more, 13.0% or more, 14.0% or more, 15.0% or more, 20.0% or more, 30.0% or more, 40.0% or more Or, 42.0% or more is preferable. If the abundance of the nitrogen-containing heterocycle is less than 3.0%, the malodor caused by urine may not be sufficiently reduced. In one embodiment of the present invention, the abundance of the nitrogen-containing heterocycle is 200% or less, or 150% or less. If the abundance of the nitrogen-containing heterocycle exceeds 200%, the absorption ratio of the water-absorbent resin composition may decrease, or the hydrophobicity may be too high to reduce the water absorption rate. Therefore, in one embodiment of the present invention, it contains at least one component of a water-absorbent resin, a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle, and the span value is 1.10 or less. When the water-absorbent resin composition contains the resin having the nitrogen-containing heterocycle, the water-absorbent resin composition in which the abundance of the nitrogen-containing heterocycle is 3.0% or more is provided.
　本発明の一実施形態において、含窒素複素環の存在度が算出される、吸水性樹脂組成物における吸水性樹脂は、ポリアクリル酸（塩）系吸水性樹脂である。 In one embodiment of the present invention, the water-absorbent resin in the water-absorbent resin composition from which the abundance of the nitrogen-containing heterocycle is calculated is a polyacrylic acid (salt) -based water-absorbent resin.
　本発明の一実施形態によれば、前記含窒素複素環が、ヘテロ原子を少なくとも１個以上有することが好ましく、２個以上有することがより好ましい。かかる実施形態であることによって、本発明の所期の効果をより効率的に奏することができる。本発明の一実施形態によれば、前記含窒素複素環が、ヘテロ原子を３個以下有することが好ましい。かかる実施形態であることによって、本発明の所期の効果をより効率的に奏することができる。なお、含窒素複素環は、窒素原子のみを含むことに制限されず、酸素原子や、硫黄原子を含むことを制限しない。 According to one embodiment of the present invention, the nitrogen-containing heterocycle preferably has at least one heteroatom, more preferably two or more. With such an embodiment, the desired effect of the present invention can be achieved more efficiently. According to one embodiment of the present invention, it is preferable that the nitrogen-containing heterocycle has 3 or less heteroatoms. With such an embodiment, the desired effect of the present invention can be achieved more efficiently. The nitrogen-containing heterocycle is not limited to containing only a nitrogen atom, and is not limited to containing an oxygen atom or a sulfur atom.
　本発明の一実施形態によれば、含窒素複素環としては、ピリジン環、ピラジン環、トリアジン環、ピリミジン環、ピリダジン環等の６員環の含窒素複素環、イミダゾール環、オキサゾール環、チアゾール環、オキサジアゾール環、チアジアゾール環、トリアゾール環、ピラゾール環、オキサゾリン環等の５員環の含窒素複素環、キノリン環、キノキサリン環、ナフチリジン環、ベンゾイミダゾール環、ベンゾチアゾール環、ベンゾオキサゾール環等の縮合含窒素複素環等が挙げられる。かかる実施形態であることによって、本発明の所期の効果をより効率的に奏することができる。 According to one embodiment of the present invention, the nitrogen-containing heterocycle includes a 6-membered nitrogen-containing heterocycle such as a pyridine ring, a pyrazine ring, a triazine ring, a pyrimidine ring, and a pyridazine ring, an imidazole ring, an oxazole ring, and a thiazole ring. , Oxazole ring, thiathiazole ring, triazole ring, pyrazole ring, oxazoline ring and other 5-membered nitrogen-containing heterocycles, quinoline ring, quinoxalline ring, naphthylidine ring, benzoimidazole ring, benzothiazole ring, benzoxazole ring and the like. Examples thereof include a condensed nitrogen-containing heterocycle. With such an embodiment, the desired effect of the present invention can be achieved more efficiently.
　中でも、本発明の所期の効果をより効率的に奏するためには、オキサゾリン環、トリアジン環、ピリジン環が好ましく、オキサゾリン環、トリアジン環がより好ましい。 Among them, an oxazoline ring, a triazine ring, and a pyridine ring are preferable, and an oxazoline ring and a triazine ring are more preferable, in order to more efficiently exert the desired effect of the present invention.
　よって、本発明の一実施形態によれば、含窒素複素環を有する樹脂がオキサゾリン基を有する重合体（オキサゾリン基含有重合体）である。このような、オキサゾリン基含有重合体において、オキサゾリン基量（オキサゾリン基含有重合体１ｇ当たりのオキサゾリン基の数）が、好ましくは０．１ｍｍｏｌ／ｇ～１０ｍｍｏｌ／ｇであり、より好ましくは０．５ｍｍｏｌ／ｇ～８ｍｍｏｌ／ｇである。 Therefore, according to one embodiment of the present invention, the resin having a nitrogen-containing heterocycle is a polymer having an oxazoline group (an oxazoline group-containing polymer). In such an oxazoline group-containing polymer, the amount of oxazoline groups (the number of oxazoline groups per 1 g of the oxazoline group-containing polymer) is preferably 0.1 mmol / g to 10 mmol / g, more preferably 0.5 mmol. It is / g to 8 mmol / g.
　本発明の一実施形態によれば、オキサゾリン基含有重合体は、オキサゾリン基含有単量体由来の構造単位を有する。 According to one embodiment of the present invention, the oxazoline group-containing polymer has a structural unit derived from the oxazoline group-containing monomer.
　本発明の一実施形態によれば、オキサゾリン基含有重合体は、オキサゾリン基含有単量体由来の構造単位とオキサゾリン基含有単量体以外のその他の単量体由来の構造単位とを有する。 According to one embodiment of the present invention, the oxazoline group-containing polymer has a structural unit derived from an oxazoline group-containing monomer and a structural unit derived from another monomer other than the oxazoline group-containing monomer.
　オキサゾリン基含有単量体としては、エチレン性不飽和炭化水素基とオキサゾリン基とを有するものであれば任意の適切な単量体を採用し得る。このようなオキサゾリン基含有単量体としては、例えば、２－ビニル－２－オキサゾリン、５－メチル－２－ビニル－２－オキサゾリン、４，４－ジメチル－２－ビニル－２－オキサゾリン、４，４－ジメチル－２－ビニル－５，５－ジヒドロ－４Ｈ－１，３－オキサゾリン、２－イソプロペニル－２－オキサゾリン、４，４－ジメチル－２－イソプロペニル－２－オキサゾリンなどが挙げられ、好ましくは、２－イソプロペニル－２－オキサゾリン、４，４－ジメチル－２－イソプロペニル－２－オキサゾリンである。 As the oxazoline group-containing monomer, any suitable monomer having an ethylenically unsaturated hydrocarbon group and an oxazoline group can be adopted. Examples of such an oxazoline group-containing monomer include 2-vinyl-2-oxazoline, 5-methyl-2-vinyl-2-oxazoline, 4,4-dimethyl-2-vinyl-2-oxazoline, and 4, Examples thereof include 4-dimethyl-2-vinyl-5,5-dihydro-4H-1,3-oxazoline, 2-isopropenyl-2-oxazoline, and 4,4-dimethyl-2-isopropenyl-2-oxazoline. Preferred are 2-isopropenyl-2-oxazoline and 4,4-dimethyl-2-isopropenyl-2-oxazoline.
　その他の単量体は、オキサゾリン基を有しない単量体であれば任意の適切な単量体を採用し得る。このようなその他の単量体としては、例えば、Ｎ－ビニルピロリドン等のＮ－ビニルラクタム系単量体；（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸プロピル、（メタ）アクリル酸ブチル、（メタ）アクリル酸シクロヘキシル、（メタ）アクリル酸２－エチルヘキシル、（メタ）アクリル酸ｎ－オクチル、（メタ）アクリル酸ｉｓｏ－ノニル、（メタ）アクリル酸ドデシル、（メタ）アクリル酸ステアリル等の（メタ）アクリル酸エステル；（メタ）アクリルアミド、Ｎ－モノメチル（メタ）アクリルアミド、Ｎ－モノエチル（メタ）アクリルアミド、Ｎ，Ｎ－ジメチル（メタ）アクリルアミド等のＮ置換または無置換の（メタ）アクリルアミド；スチレン、α－メチルスチレン、ジビニルベンゼン、ビニルトルエン、インデン、ビニルナフタレン、フェニルマレイミド、ビニルアニリン等のビニルアリール単量体；エチレン、プロピレン、ブタジエン、イソブチレン、オクテン等のアルケン；酢酸ビニル、プロピオン酸ビニル等のカルボン酸ビニル；メチルビニルエーテル、エチルビニルエーテル、ブチルビニルエーテル等のビニルエーテル；ビニルエチレンカーボネートおよびその誘導体；Ｎ，Ｎ－ジメチルアミノエチル（メタ）アクリレート、Ｎ，Ｎ－ジメチルアミノエチル（メタ）アクリルアミド、ビニルピリジン、ビニルイミダゾールおよびこれらの塩またはこれらの４級化物等の不飽和アミン；アクリロニトリル、メタクリロニトリル等のシアン化ビニル系単量体；などが挙げられる。これらの中でも、好ましくは、（メタ）アクリル酸エステル、ビニルアリール単量体、シアン化ビニル系単量体であり、より好ましくは、（メタ）アクリル酸エステルである。 As the other monomer, any suitable monomer can be adopted as long as it does not have an oxazoline group. Examples of such other monomers include N-vinyllactam-based monomers such as N-vinylpyrrolidone; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (. Butyl acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, iso-nonyl (meth) acrylate, dodecyl (meth) acrylate, (meth) (Meta) acrylic acid esters such as stearyl acrylate; N-substituted or unsubstituted (meth) acrylamide, N-monomethyl (meth) acrylamide, N-monoethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, etc. (Meta) acrylamide; Vinyl aryl monomers such as styrene, α-methylstyrene, divinylbenzene, vinyltoluene, inden, vinylnaphthalene, phenylmaleimide, vinylaniline; alkene such as ethylene, propylene, butadiene, isobutylene, octene; acrylic acid Vinyl carboxylate such as vinyl and vinyl propionate; Vinyl ether such as methyl vinyl ether, ethyl vinyl ether and butyl vinyl ether; Vinyl ethylene carbonate and its derivatives; N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminoethyl ( Meta) Unsaturated amines such as acrylamide, vinyl pyridine, vinyl imidazole and salts thereof or quaternized products thereof; vinyl cyanide-based monomers such as acryliconitrile and methacrylonitrile; and the like. Among these, (meth) acrylic acid ester, vinylaryl monomer, and vinyl cyanide-based monomer are preferable, and (meth) acrylic acid ester is more preferable.
　オキサゾリン基含有重合体においては、オキサゾリン基含有単量体由来の構造単位の割合が、全構造単位１００モル％に対して、好ましくは１５モル％～９５モル％であり、より好ましくは２０モル％～９５モル％であり、より好ましくは３０モル％～９０モル％であり、さらに好ましくは４０モル％～８５モル％である。 In the oxazoline group-containing polymer, the ratio of the structural units derived from the oxazoline group-containing monomer is preferably 15 mol% to 95 mol%, more preferably 20 mol%, based on 100 mol% of the total structural units. It is ~ 95 mol%, more preferably 30 mol% to 90 mol%, still more preferably 40 mol% to 85 mol%.
　本発明の一実施形態によれば、含窒素複素環を有する樹脂がアミノ系樹脂である。上記アミノ系樹脂としては、例えば、アミノ化合物とホルムアルデヒドとの縮合物が挙げられる。アミノ化合物としては、例えば、尿素、チオ尿素、多官能アミノ化合物等が挙げられる。なかでも、多官能アミノ化合物が好ましく用いられ、上述のとおり、トリアジン還構造を有する多官能アミノ化合物がより好ましく用いられる。トリアジン環構造を有する多官能アミノ化合物としては、例えば、メラミン；一般式（１）で表されるアミノ化合物；ベンゾグアナミン、シクロヘキサンカルボグアナミン、シクロヘキセンカルボグアナミン、アセトグアナミン、ノルボルネンカルボグアナミン、スピログアナミン等のグアナミン化合物；等が挙げられる。これらの中でも、メラミン、ベンゾグアナミンが好ましい。アミノ化合物は、１種のみを用いてもよいし、２種以上を用いてもよい。 According to one embodiment of the present invention, the resin having a nitrogen-containing heterocycle is an amino resin. Examples of the amino-based resin include a condensate of an amino compound and formaldehyde. Examples of the amino compound include urea, thiourea, and polyfunctional amino compounds. Among them, a polyfunctional amino compound is preferably used, and as described above, a polyfunctional amino compound having a triazine-returning structure is more preferably used. Examples of the polyfunctional amino compound having a triazine ring structure include melamine; an amino compound represented by the general formula (1); guanamines such as benzoguanamine, cyclohexanecarboguanamine, cyclohexenecarboguanamine, acetoguanamine, norbornenecarboguanamine, and spirognamine. Compounds; and the like. Among these, melamine and benzoguanamine are preferable. As the amino compound, only one kind may be used, or two or more kinds may be used.
Figure JPOXMLDOC01-appb-C000008
Figure JPOXMLDOC01-appb-C000008
　一般式（１）中、Ｒ１は、同一または異なり、水素原子または置換基があってもよいアルキル基を表し、Ｒ１の少なくとも１つは置換基があってもよいアルキル基である。一般式（１）中、Ｒ１は、好ましくは、水素原子、ヒドロキシアルキル基である。 In the general formula (1), R 1 represents an alkyl group which is the same or different and may have a hydrogen atom or a substituent, and at least one of R 1 is an alkyl group which may have a substituent. In the general formula (1), R 1 is preferably a hydrogen atom or a hydroxyalkyl group.
　上記アミノ系樹脂粒子がアミノ系樹脂のみから形成される場合、該樹脂は、上記のアミノ化合物とホルムアルデヒドとを任意の適切な方法により反応（付加縮合反応）させて、得ることができる。アミノ系樹脂から形成される樹脂の製造方法としては、例えば、特開２０００－２５６４３２号公報、特開２００２－２９３８５４号公報、特開２００２－２９３８５５号公報、特開２００２－２９３８５６号公報、特開２００２－２９３８５７号公報、特開２００３－５５４２２号公報、特開２００３－８２０４９号公報、特開２００３－１３８０２３号公報、特開２００３－１４７０３９号公報、特開２００３－１７１４３２号公報、特開２００３－１７６３３０号公報、特開２００５－９７５７５号公報、特開２００７－１８６７１６号公報、特開２００８－１０１０４０号公報等に記載の製造方法が挙げられる。具体的には、例えば、上記アミノ化合物（好ましくは、多官能アミノ化合物）とホルムアルデヒドを、好ましくは塩基性の水性媒体中で付加縮合反応させて縮合物オリゴマーを生成させ、該縮合物オリゴマーが溶解または分散する水性媒体にドデシルベンゼンスルホン酸や硫酸等の酸触媒を混合して硬化させることによって、架橋構造のアミノ系樹脂から形成される樹脂粒子を製造することができる。縮合物オリゴマーを生成させる段階、架橋構造のアミノ系樹脂粒子とする段階は、いずれも、５０℃～１００℃の温度で加熱された状態で行うことが好ましい。 When the amino-based resin particles are formed only from the amino-based resin, the resin can be obtained by reacting the above-mentioned amino compound with formaldehyde by an arbitrary appropriate method (condensation reaction). Examples of the method for producing a resin formed from an amino resin include JP-A-2000-256432, JP-A-2002-293854, JP-A-2002-293855, JP-A-2002-293856, and JP-A. 2002-293857, 2003-55422, 2003-82049, 2003-138023, 2003-147039, 2003-171432, 20033- Examples thereof include the production methods described in JP-A-176330, JP-A-2005-97575, JP-A-2007-186716, JP-A-2008-101040 and the like. Specifically, for example, the above amino compound (preferably a polyfunctional amino compound) and formaldehyde are subjected to a polycondensation reaction in a preferably basic aqueous medium to form a condensate oligomer, and the condensate oligomer is dissolved. Alternatively, resin particles formed from an amino-based resin having a crosslinked structure can be produced by mixing an acid catalyst such as dodecylbenzenesulfonic acid or sulfuric acid with an aqueous medium to be dispersed and curing the mixture. Both the step of forming the condensate oligomer and the step of forming the crosslinked amino resin particles are preferably carried out in a state of being heated at a temperature of 50 ° C to 100 ° C.
　本発明の一実施形態によれば、含窒素複素環を有する樹脂が、メラミン、ホルムアルデヒド縮合物であり、以下の構成単位を含む。 According to one embodiment of the present invention, the resin having a nitrogen-containing heterocycle is a melamine or formaldehyde condensate, and contains the following structural units.
Figure JPOXMLDOC01-appb-C000009
Figure JPOXMLDOC01-appb-C000009
　本発明の一実施形態によれば、含窒素複素環を有する樹脂はピリジン環を繰り返し構成単位とするポリマーである。具体的には２－ビニルピリジンや４－ビニルピリジンを原料とするポリマー、あるいはこれらのメチル化４級塩のポリマーや４－アミノピリジン分岐ポリスチレン等がある。 According to one embodiment of the present invention, the resin having a nitrogen-containing heterocycle is a polymer having a pyridine ring as a repeating constituent unit. Specifically, there are polymers made from 2-vinylpyridine and 4-vinylpyridine, polymers of these methylated quaternary salts, 4-aminopyridine branched polystyrene and the like.
　本発明の一実施形態によれば、含窒素複素環を有する樹脂の重量平均分子量は５，０００以上であることが好ましく、１０，０００以上であることがより好ましい。上限は適宜決定されるが、通常、１，０００万以下であり、１００万以下であることが好ましい。含窒素複素環を有する樹脂の重量平均分子量は、ＧＰＣにより測定される。 According to one embodiment of the present invention, the weight average molecular weight of the resin having a nitrogen-containing heterocycle is preferably 5,000 or more, and more preferably 10,000 or more. The upper limit is appropriately determined, but is usually 10 million or less, preferably 1 million or less. The weight average molecular weight of the resin having a nitrogen-containing heterocycle is measured by GPC.
　本発明の一実施形態によれば、含窒素複素環を有する樹脂は１種でも２種以上組み合わせて使用されてもよい。 According to one embodiment of the present invention, the resin having a nitrogen-containing heterocycle may be used alone or in combination of two or more.
　なお、含窒素複素環を有する樹脂は、市販品を購入することによって準備してもよい。 The resin having a nitrogen-containing heterocycle may be prepared by purchasing a commercially available product.
　本発明の一実施形態によれば、吸水性樹脂組成物が、前記吸水性樹脂と、前記成分とを結着する、バインダを含む。この技術的意義は以下のとおりであり、すなわち、吸水性樹脂組成物には、吸水性樹脂と；疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分と；の異なった材料が存在することになる。異なった材料が存在する場合、互いが、偏析する傾向にある。偏析が発生すると、安定した消臭効果が得られない場合がある。本発明の一実施形態において、前記バインダを含むことによって、吸水性樹脂と、疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分とが結着されるため、これらが、吸水性樹脂組成物内で均等に分布し、安定した消臭効果が得られる。 According to one embodiment of the present invention, the water-absorbent resin composition comprises a binder that binds the water-absorbent resin and the component. The technical significance of this is as follows: the water-absorbent resin composition is different from the water-absorbent resin; at least one component of the hydrophobic porous polymer adsorbent and the resin having a nitrogen-containing heterocycle; There will be new materials. When different materials are present, they tend to segregate from each other. When segregation occurs, a stable deodorizing effect may not be obtained. In one embodiment of the present invention, the inclusion of the binder binds the water-absorbent resin to at least one component of the hydrophobic porous polymer adsorbent and the resin having a nitrogen-containing heterocycle. , It is evenly distributed in the water-absorbent resin composition, and a stable deodorizing effect can be obtained.
　本発明の一実施形態によれば、前記バインダが、ポリオールである。ポリオールとは、水酸基を２個以上有する化合物を意味し、例えば、プロピレングリコール、エチレングリコール、テトラメチレングリコール、ジエチレングリコール、ジプロピレングリコール、ポリエチレングリコール、グリセリン等が挙げられる。 According to one embodiment of the present invention, the binder is a polyol. The polyol means a compound having two or more hydroxyl groups, and examples thereof include propylene glycol, ethylene glycol, tetramethylene glycol, diethylene glycol, dipropylene glycol, polyethylene glycol, and glycerin.
　本発明の一実施形態によれば、バインダは、吸水性樹脂（ベースポリマー）の表面架橋に用いられる表面架橋剤に含まれてもよい。 According to one embodiment of the present invention, the binder may be contained in a surface cross-linking agent used for surface cross-linking of a water-absorbent resin (base polymer).
　本発明の一実施形態によれば、前記表面架橋剤の少なくとも１種が、バインダとしての機能を兼ね備えてもよい。また、本発明の一実施形態によれば、前記バインダが、表面架橋された吸水性樹脂表面に残存している、表面架橋剤である。つまり、前記バインダは、表面架橋処理後に吸水性樹脂表面に残存している表面架橋剤でありうる。 According to one embodiment of the present invention, at least one of the surface cross-linking agents may also have a function as a binder. Further, according to one embodiment of the present invention, the binder is a surface cross-linking agent remaining on the surface of the surface-cross-linked water-absorbent resin. That is, the binder may be a surface cross-linking agent remaining on the surface of the water-absorbent resin after the surface cross-linking treatment.
　本発明の一実施形態によれば、前記吸水性樹脂組成物中に含まれるバインダの量が、好ましくは０．１～１０質量％であり、より好ましくは０．２～７質量％であり、さらに好ましくは０．３～５質量％である。バインダの量が好ましい添加量より少ない場合には、消臭効果の安定化が十分にできないおそれがある。また、バインダの量が好ましい添加量より多い場合には、吸水性樹脂の吸水倍率が低下するおそれがある。なお、前記吸水性樹脂組成物中に含まれるバインダの量は、例えば、生理食塩水等で抽出し、ＨＰＬＣ等の測定機器によって測定することができる。 According to one embodiment of the present invention, the amount of the binder contained in the water-absorbent resin composition is preferably 0.1 to 10% by mass, more preferably 0.2 to 7% by mass. More preferably, it is 0.3 to 5% by mass. If the amount of binder is less than the preferable amount, the deodorizing effect may not be sufficiently stabilized. Further, when the amount of the binder is larger than the preferable amount, the water absorption ratio of the water-absorbent resin may decrease. The amount of binder contained in the water-absorbent resin composition can be, for example, extracted with physiological saline or the like and measured by a measuring device such as HPLC.
　本発明の一実施形態において吸水性樹脂組成物に含ませるバインダの添加方法としては特に制限はなく、上述のとおり、表面処理時に添加してもよいし、表面処理後の吸水性樹脂と、バインダとを混合してもよい。 In one embodiment of the present invention, the method of adding the binder contained in the water-absorbent resin composition is not particularly limited, and as described above, it may be added at the time of surface treatment, or the water-absorbent resin after surface treatment and the binder. And may be mixed.
　本発明の一実施形態において、バインダの分子量としては、好ましくは４０～８００であり、より好ましくは５０～３００であり、さらに好ましくは６０～２００である。なお、バインダの分子量は、ガスクロマトグラフ質量分析計（ＧＣ－ＭＳ）、液クロマトグラフ質量分析計（ＬＣ－ＭＳ）や、ゲル濾過クロマトグラフィー（ＧＰＣ）等により適宜測定することができる。 In one embodiment of the present invention, the molecular weight of the binder is preferably 40 to 800, more preferably 50 to 300, and even more preferably 60 to 200. The molecular weight of the binder can be appropriately measured by a gas chromatograph mass spectrometer (GC-MS), a liquid chromatograph mass spectrometer (LC-MS), a gel filtration chromatography (GPC), or the like.
　本発明の一実施形態において、（例えば、表面架橋されている）吸水性樹脂と、疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分とを混合する場合、十分なトルクをかけて吸水性樹脂と疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分を均一かつ確実に混合することが好ましい。　　　 In one embodiment of the present invention, it is sufficient to mix a water-absorbent resin (for example, surface-crosslinked) with at least one component of a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle. It is preferable to apply torque to uniformly and surely mix at least one component of the water-absorbent resin, the hydrophobic porous polymer adsorbent, and the resin having a nitrogen-containing heterocycle. It was
　前記混合に使用する装置としては、例えば、攪拌型混合機、円筒型混合機、二重壁円錐型混合機、Ｖ字型混合機、リボン型混合機、スクリュー型混合機、流動型ロータリーデスク型混合機、気流型混合機、双腕型ニーダー、内部混合機、粉砕型ニーダー、回転式混合機、スクリュー型押出機等が好適である。攪拌型混合機を用いる場合には、その回転数は、５ｒｐｍ～１００００ｒｐｍが好ましく、１０ｒｐｍ～２０００ｒｐｍがより好ましい。 Examples of the device used for the mixing include a stirring type mixer, a cylindrical type mixer, a double-walled conical type mixer, a V-shaped mixer, a ribbon type mixer, a screw type mixer, and a fluid type rotary desk type. A mixer, an air flow type mixer, a double arm type kneader, an internal mixer, a crushing type kneader, a rotary mixer, a screw type extruder and the like are suitable. When a stirring type mixer is used, the rotation speed is preferably 5 rpm to 10000 rpm, more preferably 10 rpm to 2000 rpm.
　［２－８］キレート剤の添加工程
　本発明者らは、キレート剤を加えることで、相乗効果により、消臭効果が顕著に高まることも確認した。よって、本発明の一実施形態において、吸水性樹脂組成物は、キレート剤を含む。キレート剤の使用量は、吸水性樹脂１００質量部に対して０～３質量部が好ましく、０．００１～１質量部がより好ましく、０．０５～０．５質量部が特に好ましい。かような好ましい使用量は、吸水性樹脂組成物中における好ましい含有量と一致する。すなわち、本発明の一実施形態によれば、吸水性樹脂組成物中において、キレート剤の含有量は、吸水性樹脂１００質量部に対して０～３質量部が好ましく、０．００１～１質量部がより好ましく、０．０５～０．５質量部が特に好ましい。なお、これらは単量体や含水ゲル、乾燥重合体や粉末等に添加され、添加工程は重合工程以降に適宜決定されるが、重合後、さらには乾燥後、特に表面架橋後に添加することが好ましい。 [2-8] Step of adding chelating agent The present inventors have also confirmed that the deodorizing effect is remarkably enhanced by the synergistic effect by adding the chelating agent. Therefore, in one embodiment of the present invention, the water-absorbent resin composition contains a chelating agent. The amount of the chelating agent used is preferably 0 to 3 parts by mass, more preferably 0.001 to 1 part by mass, and particularly preferably 0.05 to 0.5 part by mass with respect to 100 parts by mass of the water-absorbent resin. Such a preferred amount is consistent with the preferred content in the water-absorbent resin composition. That is, according to one embodiment of the present invention, the content of the chelating agent in the water-absorbent resin composition is preferably 0 to 3 parts by mass, preferably 0.001 to 1 part by mass with respect to 100 parts by mass of the water-absorbent resin. Parts are more preferable, and 0.05 to 0.5 parts by mass are particularly preferable. These are added to monomers, hydrogels, dry polymers, powders, etc., and the addition step is appropriately determined after the polymerization step, but they may be added after polymerization, further drying, and especially after surface cross-linking. preferable.
　使用できるキレート剤は、米国特許第６５９９９８９号、同第６４６９０８０号、欧州特許第２１６３３０２号等に例示のキレート剤、特に非高分子キレート剤、さらには有機リン系キレート剤、ジエチレントリアミン５酢酸またはその塩、エチレンジアミン４酢酸またはその塩等のアミノカルボン酸系キレート剤が使用できる。 The chelating agents that can be used are the chelating agents exemplified in US Patent No. 6599989, No. 6469080, European Patent No. 2163302, etc., particularly non-polymeric chelating agents, further organic phosphorus chelating agents, diethylenetriamine 5 acetic acid or salts thereof. , Aminocarboxylic acid-based chelating agents such as ethylenediamine tetraacetic acid or a salt thereof can be used.
　［２－９］着色防止剤又は耐尿性向上剤の添加工程
　一般的には、吸水性樹脂は着色や劣化しやすい傾向もあるため、本発明では着色防止や劣化防止のために、α－ヒドロキシカルボン酸（特に乳酸又はその塩）、無機又は有機還元剤（特に硫黄系無機還元剤）から選ばれる着色防止剤又は耐尿性（耐候性）向上剤をさらに含むことが好ましい。これらの使用量は吸水性樹脂１００質量部に対して、固形分で０～３質量部が好ましく、０．００１～１質量部がより好ましく、０．０５～０．５質量部が特に好ましい。かような好ましい使用量は、吸水性樹脂組成物中における好ましい含有量と一致する。すなわち、本発明の一実施形態によれば、吸水性樹脂組成物中において、着色防止剤又は耐尿性向上剤の含有量は、それぞれ独立して、吸水性樹脂１００質量部に対して０～３質量部が好ましく、０．００１～１質量部がより好ましく、０．０５～０．５質量部が特に好ましい。これらは単量体や含水ゲル、乾燥重合体や粉末等に添加され、添加工程は重合工程以降に適宜決定されるが、これらの中で還元剤は重合で消費されるため、重合後、さらには乾燥後に特に表面架橋後に添加することが好ましい。 [2-9] Step of Adding Anticoloring Agent or Urinary Resistance Improving Agent Generally, water-absorbent resins tend to be colored or deteriorated easily. Therefore, in the present invention, α- is used to prevent coloring and deterioration. It is preferable to further contain a color inhibitor or a urine resistance (weather resistance) improving agent selected from hydroxycarboxylic acids (particularly lactic acid or salts thereof), inorganic or organic reducing agents (particularly sulfur-based inorganic reducing agents). The amount of these used is preferably 0 to 3 parts by mass, more preferably 0.001 to 1 part by mass, and particularly preferably 0.05 to 0.5 part by mass with respect to 100 parts by mass of the water-absorbent resin. Such a preferred amount is consistent with the preferred content in the water-absorbent resin composition. That is, according to one embodiment of the present invention, the content of the anticoloring agent or the urine resistance improving agent in the water-absorbent resin composition is independently 0 to 0 to 100 parts by mass of the water-absorbent resin. 3 parts by mass is preferable, 0.001 to 1 part by mass is more preferable, and 0.05 to 0.5 parts by mass is particularly preferable. These are added to monomers, hydrogels, dry polymers, powders, etc., and the addition step is appropriately determined after the polymerization step. However, since the reducing agent is consumed in the polymerization, further after the polymerization. Is preferably added after drying, especially after surface cross-linking.
　α－ヒドロキシカルボン酸は米国特許出願公開第２００９／０３１２１８３号等に例示の林檎酸、琥珀酸、乳酸やその塩（特に一価塩）が例示できる。使用できる無機又は有機還元剤（特に硫黄系無機還元剤）は米国特許出願公開第２０１０／００６２２５２号等に例示の硫黄系還元剤、特に亜硫酸塩又は亜硫酸水素塩等が例示される。 Examples of the α-hydroxycarboxylic acid include malic acid, succinic acid, lactic acid and salts thereof (particularly monovalent salts) exemplified in US Patent Application Publication No. 2009/0312183. Examples of the inorganic or organic reducing agent (particularly sulfur-based inorganic reducing agent) that can be used include sulfur-based reducing agents exemplified in US Patent Application Publication No. 2010/0062252, and particularly sulfite or hydrogen sulfite.
　［２－１０］抗菌剤の添加工程
　本発明では、吸水性樹脂組成物が抗菌剤をさらに含んでいてもよい。尿に起因する悪臭は、微生物等が経時で増殖し、尿中の有機物を分解することで発生する腐敗臭・刺激臭が経時で増加する。抗菌剤をさらに含有することによって初期尿臭の抑制のみならず、微生物等の経時での増殖抑制による中～長期経過後の尿臭の抑制も達成することができる。 [2-10] Step of Adding Antibacterial Agent In the present invention, the water-absorbent resin composition may further contain an antibacterial agent. As for the bad odor caused by urine, the putrid odor and pungent odor generated by the decomposition of organic substances in urine due to the proliferation of microorganisms and the like over time increase. By further containing an antibacterial agent, not only the suppression of the initial urine odor but also the suppression of the urine odor after a medium to long-term lapse by suppressing the growth of microorganisms over time can be achieved.
　吸水性樹脂と抗菌剤とを混合する手順は特に限定されず、例えば、表面架橋される前のベースポリマーに抗菌剤を添加してからベースポリマーを表面架橋してもよいが、抗菌剤の消臭効果を高めるためには、表面架橋された吸水性樹脂に抗菌剤を添加するのが好ましい。 The procedure for mixing the water-absorbent resin and the antibacterial agent is not particularly limited. For example, the antibacterial agent may be added to the base polymer before surface cross-linking and then the base polymer may be surface-crosslinked. In order to enhance the odor effect, it is preferable to add an antibacterial agent to the surface-crosslinked water-absorbent resin.
　抗菌剤とは、黄色ブドウ球菌、大腸菌、アンモニア産生菌などのような菌の増殖を抑制する効果を有するものである。抗菌剤は、Ａｇ、Ｃｕ、Ｚｎ等の抗菌性金属を有効成分として無機担体に担持したり、有機化合物の塩または錯体として含有する無機系抗菌剤と、抗菌性金属を含有しない有機系抗菌剤に大別できる。本発明の実施形態において、微生物等の経時での増殖抑制の効果を有する任意の無機系抗菌剤または有機系抗菌剤を好ましく用いることができる。中でも、抗菌性金属による人体への悪影響懸念を払拭することができる点で、有機系抗菌剤がより好ましい。 The antibacterial agent has the effect of suppressing the growth of bacteria such as Staphylococcus aureus, Escherichia coli, and ammonia-producing bacteria. The antibacterial agent is an inorganic antibacterial agent that carries an antibacterial metal such as Ag, Cu, Zn as an active ingredient on an inorganic carrier or contains it as a salt or complex of an organic compound, and an organic antibacterial agent that does not contain an antibacterial metal. Can be roughly divided into. In the embodiment of the present invention, any inorganic antibacterial agent or organic antibacterial agent having an effect of suppressing the growth of microorganisms over time can be preferably used. Of these, organic antibacterial agents are more preferable because they can eliminate concerns about adverse effects on the human body caused by antibacterial metals.
　無機系抗菌剤としては、具体的には、ゼオライト、シリカゲル、ケイ酸カルシウム、粘土鉱物等のケイ酸塩類に抗菌性金属を担持したケイ酸塩系；リン酸ジルコニウム、リン酸カルシウム、リン酸アルミニウム、ヒドロキシアパタイト等のリン酸塩類に抗菌性金属を担持したリン酸塩系；抗菌性金属ナノ粒子等の単体金属；抗菌性金属のハロゲン化物、酸化物等の抗菌性金属化合物；有機化合物、ポリマー等の抗菌性金属塩または錯体等を例示することができる。 Specific examples of the inorganic antibacterial agent include silicate-based agents in which an antibacterial metal is carried on silicates such as zeolite, silica gel, calcium silicate, and clay mineral; zirconium phosphate, calcium phosphate, aluminum phosphate, and hydroxy. Phosphates carrying antibacterial metals on phosphates such as apatite; single metals such as antibacterial metal nanoparticles; antibacterial metal compounds such as halides and oxides of antibacterial metals; organic compounds, polymers, etc. Examples thereof include antibacterial metal salts or complexes.
　よって、本発明の一実施形態において、無機系抗菌剤（ケイ酸塩類（例えばゼオライト等）に抗菌性金属（例えばＡｇ））が担持されたもの）が吸水性樹脂組成物中に含まれない、あるいは、仮に含まれる場合、その含有割合は、１０質量ｐｐｍ未満、９質量ｐｐｍ以下、７質量ｐｐｍ以下、あるいは、５質量ｐｐｍ以下がよい。 Therefore, in one embodiment of the present invention, the water-absorbent resin composition does not contain an inorganic antibacterial agent (an antibacterial metal (for example, Ag) carried on silicates (for example, zeolite)). Alternatively, if it is contained, the content ratio may be less than 10 mass ppm, 9 mass ppm or less, 7 mass ppm or less, or 5 mass ppm or less.
　有機系抗菌剤としては、具体的には、２－ブロモ－２－ニトロ－１，３－プロパンジオール、Ｎ－（２－ヒドロキシプロピル）－アミノメタノール等のアルコール系化合物；３－メチル－４－イソプロピルフェノール（イソプロピルメチルフェノール）、２－イソプロピル－５－メチルフェノール、ｏ－フェニルフェノール、ｏ－フェニルフェノールナトリウム、クロロキシレノール（４－クロロ－３、５－ジメチルフェノール）、ｐ－クロロｍ－クレゾール、トリブロモフェノール、４－クロロ－２－フェニルフェノール等のフェノール系化合物；脂肪酸モノグリセライド、ｐ－ヒドロキシ安息香酸エステル、ショ糖脂肪酸エステル等のエステル系化合物；２，４，４’－トリクロロ－２’－ヒドロキシジフェニールエーテル等のエーテル系化合物；２，４，５，６－テトラクロロイソフタロニトリル、１，２－ジブロモ－２，４－ジシアノブタン等のニトリル系化合物；塩素化イソシアヌール酸、αークロロナフタレン、ポリビニルピロリドンヨード等のハロゲン系抗菌剤；（２－ピリジルチオ－１－オキシド）、２．３．５．６－テトラクロロ－４（メチルスルフォニル）ピリジン等のピリジン・キノリン系抗菌剤；ヘキサヒドロ－１，３，５－トリス（２－ヒドロキシエチル）－Ｓ－トリアジン等のトリアジン系化合物；５－クロロ－２－メチル－４－イソチアゾリン－３－オン、２－メチル－４－イソチアゾリン－３－オン、２－ｎ－オクチル－４－イソチアゾリン－３－オン、１、２－ベンゾチアゾロン等のイソチアゾロン系化合物；２－（４－チオシアノメチルチオ）ベンズイミダゾール、２－（４’－チアゾリル）ベンズイミダゾール、２－メトキシカルボニルアミノベンズイミダゾール等のイミダゾール・チアゾール系化合物；３，４，４－トリクロロカルバニリド、３－トリフルオロメチル－４，４’－ジクロルカルバニリド等のアニリド系化合物；ポリヘキサメチレンビグアニジン塩酸塩、ポリヘキサメチレンビグアニジングルコン酸塩、クロルヘキシジン塩酸塩、クロルヘキシジングルコン酸塩等のビグアナイド系化合物；ビス（ジメチルチオカーバモイル）ジスルフィド等のジスルフィド系化合物；ポリグルコサミン、キトサン、アミノグリコシドＳＴ－７等の糖質系化合物；ヒノキチオール等のトロポロン系抗菌剤；アルキルベンジルジメチルアンモニウム塩（塩化ベンザルコニウム等）、アルキルジメチルアンモニウムクロライド、ジデシルジメチルアンモニウムクロライド、ジデシルジメチルアンモニウムグルコン酸塩、セチルジメチルベンジルアンモニウムクロライド、オクタデシルアミン酢酸塩、３ー（トリメトキシシリル）プロピルジメチルオクタデシルアンモニウムクロライド、ポリ［ポリメチレン（ジメチルイミニオ）クロライド］、ポリ［オキシエチレン（ジメチルイミニオ）エチレン（ジメチルイミニオ）エチレンジクロライド］、等の第４級アンモニウム塩系化合物、アルキルジ（アミノエチル）グリシン、アルキルベタイン、脂肪族モノグリセライド等に代表される両性、アニオン性界面活性剤系化合物等を例示することができる。これらの中でも吸水性樹脂組成物への安定した抗菌性の付与という観点から、抗菌剤が水溶性、水分散性のものが特に好ましく用いられ、なかでもフェノール系化合物、第４級アンモニウム塩系化合物、ビグアナイド系化合物、両性、アニオン性界面活性剤系化合物が好ましく用いられる。 Specific examples of the organic antibacterial agent include alcohol compounds such as 2-bromo-2-nitro-1,3-propanediol and N- (2-hydroxypropyl) -aminomethanol; 3-methyl-4- Isopropylphenol (isopropylmethylphenol), 2-isopropyl-5-methylphenol, o-phenylphenol, o-phenylphenol sodium, chloroxylenol (4-chloro-3,5-dimethylphenol), p-chlorom-cresol, Phenolic compounds such as tribromophenol and 4-chloro-2-phenylphenol; ester compounds such as fatty acid monoglyceride, p-hydroxybenzoic acid ester and sucrose fatty acid ester; 2,4,4'-trichloro-2'- Ethereal compounds such as hydroxydiphenyl ether; nitrile compounds such as 2,4,5,6-tetrachloroisophthalonitrile, 1,2-dibromo-2,4-dicyanobutane; chlorinated isocyanuric acid, α- Halogen antibacterial agents such as chloronaphthalene and polyvinylpyrrolidone iodine; pyridine / quinoline antibacterial agents such as (2-pyridylthio-1-oxide), 2.3.5.6-tetrachloro-4 (methylsulfonyl) pyridine; hexahydro Triazine compounds such as -1,3,5-tris (2-hydroxyethyl) -S-triazine; 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one On, 2-n-octyl-4-isothiazolin-3-one, isothiazolone compounds such as 1,2-benzothiazolone; 2- (4-thiocyanomethylthio) benzimidazole, 2- (4'-thiazolyl) benzimidazole, Imidazole-thiazole compounds such as 2-methoxycarbonylaminobenzimidazole; anilide compounds such as 3,4,4-trichlorocarbanilide, 3-trifluoromethyl-4,4'-dichlorocarbanilide; polyhexa Biguanide compounds such as methylenebiguanidine hydrochloride, polyhexamethylenebiguanidylconate, chlorhexidine hydrochloride, chlorhexizinglconate; disulfide compounds such as bis (dimethylthiocarbamoyl) disulfide; polyglucosamine, chitosan, aminoglycoside ST Sugar-based compounds such as -7; Troporon-based antibacterial agents such as hinokithiol; Alkylbenzyldimethylammonium salts (benzalconium chloride, etc.), Alkyldimethylammonium chloride, didecyldimethylammonium chloride, didecyldimethylammonium gluconate, cetyldimethylbenzylammonium chloride, octadecylamine acetate, 3- (trimethoxysilyl) propyldimethyloctadecylammonium chloride, poly [polymethylene (dimethyliminio) ) Chloride], poly [oxyethylene (dimethyliminio) ethylene (dimethyliminio) ethylene dichloride], etc., represented by quaternary ammonium salt compounds, alkyldi (aminoethyl) glycine, alkylbetaine, aliphatic monoglyceride, etc. Examples thereof include amphoteric and anionic surfactant compounds. Among these, from the viewpoint of imparting stable antibacterial properties to the water-absorbent resin composition, water-soluble and water-dispersible antibacterial agents are particularly preferably used, and among them, phenol-based compounds and quaternary ammonium salt-based compounds are used. , Biguanide compounds, amphoteric and anionic surfactant compounds are preferably used.
　本発明の実施形態において、前記吸水性樹脂に対する前記抗菌剤の添加量が、腐敗臭、刺激臭発生の抑制効果の観点から、０．００１～５質量％であることが好ましく、より好ましくは０．０１～４質量％、さらに好ましくは０．０３～３質量％、特に好ましくは０．０５～２質量％である。 In the embodiment of the present invention, the amount of the antibacterial agent added to the water-absorbent resin is preferably 0.001 to 5% by mass, more preferably 0, from the viewpoint of the effect of suppressing the generation of putrefactive odor and pungent odor. It is 0.01 to 4% by mass, more preferably 0.03 to 3% by mass, and particularly preferably 0.05 to 2% by mass.
　［２－１１］　その他の工程
　本発明においては、上述した工程以外に、造粒工程、整粒工程、微粉除去工程、微粉回収工程、微粉の再利用工程、その他の添加剤の添加工程、除鉄工程等を、必要に応じて実施することができる。また、輸送工程、貯蔵工程、梱包工程、保管工程等から選択される少なくとも１種類の工程をさらに含んでいてもよい。 [2-11] Other Steps In the present invention, in addition to the above-mentioned steps, a granulation step, a granulation step, a fine powder removal step, a fine powder recovery step, a fine powder reuse step, a step of adding other additives, and removal of the fine powder. The iron process and the like can be carried out as needed. Further, at least one kind of process selected from a transportation process, a storage process, a packing process, a storage process, and the like may be further included.
　なお、前記整粒工程には、表面架橋工程以降で微粉を分級して除去する工程や、吸水性樹脂が凝集して所望の大きさを超えた場合に分級、粉砕を行う工程を含む。また、前記微粉の再利用工程は微粉をそのまま、または造粒工程で大きな含水ゲルにして、吸水性樹脂の製造工程の何れかの工程で原料である含水ゲル等に添加する工程を含む。 The granulation step includes a step of classifying and removing fine powder after the surface cross-linking step, and a step of classifying and pulverizing when the water-absorbent resin aggregates and exceeds a desired size. Further, the step of reusing the fine powder includes a step of turning the fine powder into a large water-containing gel as it is or in a granulation step and adding it to a water-containing gel or the like as a raw material in any step of the manufacturing step of the water-absorbent resin.
　また、前記着色防止剤又は耐尿性向上剤の添加工程では、吸水剤に様々な機能を付与させるために、酸化剤、金属石鹸等の有機粉末、パルプや熱可塑性繊維等から選ばれるその他の添加剤の１つ以上を、前記着色防止剤又は耐尿性向上剤と共に、或いは着色防止剤又は耐尿性向上剤と変えて添加することもできる。またこれらその他の添加剤は、前記表面架橋剤と同時にまたは別途、混合することができる。すなわち本発明の吸水性樹脂組成物は、こうしたその他の添加剤も含有し得る。 Further, in the step of adding the anticoloring agent or the urine resistance improving agent, in order to impart various functions to the water absorbing agent, other organic powders such as oxidizing agents and metal soaps, pulp and thermoplastic fibers are selected. One or more of the additives may be added together with the anticoloring agent or the urine resistance improving agent, or in place of the anticoloring agent or the urine resistance improving agent. Further, these other additives can be mixed at the same time as or separately from the surface cross-linking agent. That is, the water-absorbent resin composition of the present invention may also contain such other additives.
　本発明の一実施形態においては、吸水性樹脂組成物は、フェノール性化合物を重合する機能を有する材料を含まなくてもよい。 In one embodiment of the present invention, the water-absorbent resin composition does not have to contain a material having a function of polymerizing a phenolic compound.
　本発明の一実施形態において、吸水性樹脂組成物が、天然消臭剤成分（特に、植物成分）を含まなくてもよい。 In one embodiment of the present invention, the water-absorbent resin composition may not contain a natural deodorant component (particularly, a plant component).
　［３］　吸水性樹脂組成物の特性
　［３－１］　スパン値
　本発明の一実施形態において、吸水性樹脂組成物は、そのスパン値が、１．１０以下である。スパン値が１．１０を超えると本発明の所期の効果を達成することができない。本発明の実施形態によれば、スパン値が０．４０以上である。かかる実施形態によれば、本発明の所期の効果を効率的に奏することができる。本発明の実施形態によれば、０．４０～１．１０であることが好ましく、０．４５～１．０５であることがより好ましく、０．５０～１．００であることがさらに好ましい。スパン値を特定値以下に調整して、特に、疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分と組み合わせることによって、所期の消臭効果が得られるメカニズムは定かではなく、消臭性とは一見すると全く関係ない構成が、課題解決に寄与する驚くべき結果であった。 [3] Characteristics of the water-absorbent resin composition [3-1] Span value In one embodiment of the present invention, the water-absorbent resin composition has a span value of 1.10 or less. If the span value exceeds 1.10, the desired effect of the present invention cannot be achieved. According to the embodiment of the present invention, the span value is 0.40 or more. According to such an embodiment, the desired effect of the present invention can be efficiently achieved. According to the embodiment of the present invention, it is preferably 0.40 to 1.10, more preferably 0.45 to 1.05, and even more preferably 0.50 to 1.00. The mechanism by which the desired deodorant effect can be obtained by adjusting the span value to a specific value or less and combining it with at least one component of a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle is unclear. Rather, the composition, which has nothing to do with deodorant properties at first glance, was a surprising result that contributed to solving the problem.
　［３－２］　吸水性樹脂組成物のその他の特性
　本発明の一実施形態において、吸水性樹脂は、さらに以下に示す特性を備えているのが好ましい。 [3-2] Other Characteristics of Water-absorbent Resin Composition In one embodiment of the present invention, the water-absorbent resin preferably further has the following characteristics.
　（３－２－１）質量平均粒子径Ｄ（５０％）
　本発明の一実施形態において、吸水性樹脂組成物の質量平均粒子径Ｄ（５０％）は、３００μｍ以上が好ましく、３０５μｍ以上がより好ましく、３１０μｍ以上がさらに好ましく、３１５μｍ以上が特に好ましい。また、６００μｍ以下が好ましく、５５０μｍ以下がより好ましく、５００μｍ以下がさらに好ましく、４５０μｍ以下が特に好ましい。当該質量平均粒子径Ｄ（５０％）の範囲としては、上記上下限値から任意に組み合わせた範囲が適用される。 (3-2-1) Mass average particle size D (50%)
In one embodiment of the present invention, the mass average particle size D (50%) of the water-absorbent resin composition is preferably 300 μm or more, more preferably 305 μm or more, further preferably 310 μm or more, and particularly preferably 315 μm or more. Further, 600 μm or less is preferable, 550 μm or less is more preferable, 500 μm or less is further preferable, and 450 μm or less is particularly preferable. As the range of the mass average particle diameter D (50%), a range arbitrarily combined from the above upper and lower limit values is applied.
　吸水性樹脂の質量平均粒子径Ｄ（５０％）を前記範囲内とすることで、後述する本発明の一実施形態において、吸水性組成物の、無加圧下吸収倍率（ＣＲＣ）や加圧下吸収倍率（ＡＡＰ）をバランスよく制御することができる。つまり、前記範囲内とすることで、無加圧下吸収倍率（ＣＲＣ）や加圧下吸収倍率（ＡＡＰ）を高めることができ、吸水性樹脂の粒子の粗さを抑制し使い捨てオムツや生理用ナプキン等の吸収性物品に用いたときに、肌触りや装着感を向上することができる。 By setting the mass average particle size D (50%) of the water-absorbent resin within the above range, in one embodiment of the present invention described later, the water-absorbent composition has an absorption ratio under no pressure (CRC) and absorption under pressure. The magnification (AAP) can be controlled in a well-balanced manner. That is, by keeping it within the above range, the absorption ratio under no pressure (CRC) and the absorption ratio under pressure (AAP) can be increased, the roughness of the particles of the water-absorbent resin can be suppressed, and disposable diapers, sanitary napkins, etc. When used in an absorbent article, it can improve the feel and fit.
　（３－２－２）ＣＲＣ（無加圧下吸収倍率）
　本発明の一実施形態において、吸水性樹脂組成物のＣＲＣ（遠心分離機保持容量）は、通常５ｇ／ｇ以上であり、好ましくは２０ｇ／ｇ以上、より好ましくは２４ｇ／ｇ以上、さらに好ましくは３０ｇ／ｇ以上である。上限値については特に限定されず高値ほど好ましいが、他の物性とのバランスの観点から、好ましくは７０ｇ／ｇ以下、より好ましくは５０ｇ／ｇ以下、さらに好ましくは４５ｇ／ｇ以下である。したがって、上記ＣＲＣ（遠心分離機保持容量）の代表的な範囲としては、上述した上限値及び下限値の範囲内で適宜選択することができる。例えば、５～７０ｇ／ｇ、２０～５０ｇ／ｇ、２４～４５ｇ／ｇ等、任意の範囲を選択することができる。 (3-2-2) CRC (absorption rate under no pressurization)
In one embodiment of the present invention, the CRC (centrifugal force holding capacity) of the water-absorbent resin composition is usually 5 g / g or more, preferably 20 g / g or more, more preferably 24 g / g or more, still more preferably. It is 30 g / g or more. The upper limit is not particularly limited, and a higher value is preferable, but from the viewpoint of balance with other physical characteristics, it is preferably 70 g / g or less, more preferably 50 g / g or less, still more preferably 45 g / g or less. Therefore, as a typical range of the CRC (centrifugal holding capacity), it can be appropriately selected within the range of the above-mentioned upper limit value and the above-mentioned lower limit value. For example, any range can be selected, such as 5 to 70 g / g, 20 to 50 g / g, and 24 to 45 g / g.
　上記ＣＲＣが５ｇ／ｇ未満の場合、吸水性樹脂組成物の吸水量が小さく、紙オムツ等の吸収性物品の吸収体として適さない。また、上記ＣＲＣが７０ｇ／ｇを超える場合、尿や血液等の体液等を吸収する速度が低下するため、高吸水速度タイプの紙オムツ等への使用に適さない。なお、ＣＲＣは、内部架橋剤や表面架橋剤等で制御することができる。 When the CRC is less than 5 g / g, the water absorption amount of the water-absorbent resin composition is small, and it is not suitable as an absorber for absorbent articles such as disposable diapers. Further, when the CRC exceeds 70 g / g, the rate of absorbing body fluids such as urine and blood decreases, so that it is not suitable for use in high water absorption rate type disposable diapers and the like. The CRC can be controlled by an internal cross-linking agent, a surface cross-linking agent, or the like.
　（３－２－３）ＡＡＰ（加圧下吸水倍率）
　本発明の一実施形態において、吸水性樹脂組成物のＡＡＰ（加圧下吸水倍率）は、好ましくは５ｇ／ｇ以上、より好ましくは８ｇ／ｇ以上、さらに好ましくは１０ｇ／ｇ以上、よりさらに好ましくは１２ｇ／ｇ以上であり、好ましくは１４ｇ／ｇ以上であり、よりさらに好ましくは１８ｇ／ｇ以上であり、よりさらに好ましくは２２ｇ／ｇ以上である。上限値については特に限定されないが、好ましくは３０ｇ／ｇ以下である。 (3-2-3) AAP (water absorption ratio under pressure)
In one embodiment of the present invention, the AAP (water absorption ratio under pressure) of the water-absorbent resin composition is preferably 5 g / g or more, more preferably 8 g / g or more, still more preferably 10 g / g or more, still more preferably. It is 12 g / g or more, preferably 14 g / g or more, still more preferably 18 g / g or more, and even more preferably 22 g / g or more. The upper limit is not particularly limited, but is preferably 30 g / g or less.
　上記ＡＡＰが５ｇ／ｇ未満の場合、紙オムツ等で実際に使用される際、吸収体に圧力が加わった状態での吸収量が低下するため、紙オムツ等の吸収性物品の吸収体として適さない。なお、ＡＡＰは、粒度や表面架橋剤等で制御することができる。 When the above AAP is less than 5 g / g, when it is actually used in a disposable diaper or the like, the amount of absorption when pressure is applied to the absorbent body decreases, so that it is suitable as an absorber for absorbent articles such as disposable diapers. not. The AAP can be controlled by the particle size, the surface cross-linking agent, or the like.
　（３－２－４）接触角
　本発明の一実施形態において、吸水性樹脂組成物の接触角が３５°以上であることが好ましく、４０°以上であることがより好ましく、４５°以上であることがさらに好ましいく、５０°以上、５４°以上、５５°以上、５６°以上あるいは、１００°超もまたよりさらに好ましい。 (3-2-4) Contact angle In one embodiment of the present invention, the contact angle of the water-absorbent resin composition is preferably 35 ° or more, more preferably 40 ° or more, and more preferably 45 ° or more. More preferably, 50 ° or more, 54 ° or more, 55 ° or more, 56 ° or more, or more than 100 ° is also even more preferable.
　接触角が、かような下限を有することによって、吸水性樹脂による尿等の吸収が遅くなる。そうすると吸収体や吸収性物品に適用した時に尿等の拡散性が向上する。そのため尿等の吸水性樹脂に触れる面積が多くなり消臭剤の有効面積の活用が図れる。さらに尿戻りも少なくなる効果が期待できる。 When the contact angle has such a lower limit, the absorption of urine, etc. by the water-absorbent resin is delayed. Then, when applied to an absorbent body or an absorbent article, the diffusibility of urine or the like is improved. Therefore, the area that comes into contact with the water-absorbent resin such as urine increases, and the effective area of the deodorant can be utilized. Furthermore, the effect of reducing urine return can be expected.
　本発明の一実施形態において、吸水性樹脂組成物の接触角が、１２０°以下であることが好ましく、接触角が、１１０°以下であることがより好ましい。かような上限を有することによって、吸水性樹脂による尿等の吸収が過度に遅くならないため、吸収体や吸収性物品に適用した時に尿等が漏れることを防止できる。 In one embodiment of the present invention, the contact angle of the water-absorbent resin composition is preferably 120 ° or less, and more preferably the contact angle is 110 ° or less. By having such an upper limit, absorption of urine or the like by the water-absorbent resin is not excessively delayed, so that it is possible to prevent urine or the like from leaking when applied to an absorber or an absorbent article.
　（特に好ましい実施形態の組み合わせ）
　本発明において説明された実施形態（形態）はいずれの組み合わせも開示されているものとみなされるが（つまり適法な補正の根拠となるが）、特に好ましい実施形態あるいはその組み合わせを説明する。 (A particularly preferred combination of embodiments)
Although any combination of embodiments described in the present invention is considered to be disclosed (ie, grounds for legal amendment), particularly preferred embodiments or combinations thereof will be described.
　本発明の一実施形態において、疎水性多孔質ポリマー吸着剤が、スチレン系吸着剤である。 In one embodiment of the present invention, the hydrophobic porous polymer adsorbent is a styrene-based adsorbent.
　本発明の一実施形態において、前記含窒素複素環を有する樹脂が、水不溶性またはＬｏｇＰが１．５以上の水に分散可能なポリマーである。 In one embodiment of the present invention, the resin having a nitrogen-containing heterocycle is a polymer that is water-insoluble or dispersible in water having a LogP of 1.5 or more.
　本発明の一実施形態において、前記含窒素複素環を有する樹脂の添加量が、前記吸水性樹１００質量部に対し、０．３質量部超、０．５質量部超、１．０質量部超、１．５質量部以上、あるいは、２．０質量部以上である。 In one embodiment of the present invention, the amount of the resin having the nitrogen-containing heterocycle added is more than 0.3 parts by mass, more than 0.5 parts by mass, and 1.0 part by mass with respect to 100 parts by mass of the water-absorbent tree. Ultra, 1.5 parts by mass or more, or 2.0 parts by mass or more.
　本発明の一実施形態によれば、前記含窒素複素環に、ヘテロ原子が２個含まれる。 According to one embodiment of the present invention, the nitrogen-containing heterocycle contains two heteroatoms.
　本発明の一実施形態において、前記含窒素複素環を有する樹脂が水不溶性またはＬｏｇＰが１．５以上の水に分散可能なポリマーであり、かつ、含窒素複素環を有する樹脂の添加量が、前記吸水性樹脂１００質量部に対し、０．３質量部超、０．５質量部超、１．０質量部超、１．５質量部以上、あるいは、２．０質量部以上である。さらに前記含窒素複素環に、ヘテロ原子が２個含まれる。 In one embodiment of the present invention, the amount of the resin having a nitrogen-containing heterocycle added is such that the resin having a nitrogen-containing heterocycle is water-insoluble or a polymer having a LogP of 1.5 or more dispersible in water, and the resin having a nitrogen-containing heterocycle is added. It is more than 0.3 parts by mass, more than 0.5 parts by mass, more than 1.0 part by mass, 1.5 parts by mass or more, or 2.0 parts by mass or more with respect to 100 parts by mass of the water-absorbent resin. Further, the nitrogen-containing heterocycle contains two heteroatoms.
　本発明の一実施形態において、吸水性樹脂組成物が、前記吸水性樹脂と、前記疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分とを結着する、バインダを含む。 In one embodiment of the present invention, the water-absorbent resin composition binds the water-absorbent resin to at least one component of the hydrophobic porous polymer adsorbent and the resin having a nitrogen-containing heterocycle. include.
　本発明の一実施形態において、吸水性樹脂組成物が、キレート剤を含む。 In one embodiment of the present invention, the water-absorbent resin composition contains a chelating agent.
　本発明の一実施形態において、吸水性樹脂組成物の接触角が、５０°以上、５５°以上、あるいは、１００°超である。 In one embodiment of the present invention, the contact angle of the water-absorbent resin composition is 50 ° or more, 55 ° or more, or 100 ° or more.
　本発明の一実施形態によれば、吸水性樹脂１ｇあたりの疎水性多孔質ポリマー吸着剤の総比表面積としては、２．５ｍ２超、３．０ｍ２超、あるいは、３．５ｍ２超である。 According to one embodiment of the present invention, the total specific surface area of the hydrophobic porous polymer adsorbent per 1 g of the water-absorbent resin is more than 2.5 m 2 or more than 3.0 m 2 or more than 3.5 m 2 . be.
　本発明の一実施形態において、含窒素複素環の存在度が、７．０％以上、１４．０％以上、あるいは、４２．０％以上である。 In one embodiment of the present invention, the abundance of the nitrogen-containing heterocycle is 7.0% or more, 14.0% or more, or 42.0% or more.
　［４］　吸水性樹脂組成物の用途（吸収体、吸収層）
　本発明に係る吸水性樹脂組成物は、主に使い捨てオムツや生理用ナプキン等の吸収性物品の吸収体（吸収層）として使用されることが好ましく、吸収性物品１枚当たりの使用量が多い、吸収性物品の吸収体（吸収層）として使用されることがより好ましい。よって、本発明の一実施形態において、吸水性樹脂組成物と、親水性繊維とを含む、吸収体が提供される。 [4] Uses of water-absorbent resin composition (absorbent, absorbent layer)
The water-absorbent resin composition according to the present invention is preferably used mainly as an absorbent body (absorbent layer) for absorbent articles such as disposable diapers and menstrual napkins, and the amount used per absorbent article is large. , It is more preferable to use it as an absorber (absorbent layer) of an absorbent article. Therefore, in one embodiment of the present invention, an absorber containing a water-absorbent resin composition and hydrophilic fibers is provided.
　前記吸収体は、粒子状吸水剤をシート状や繊維状、筒状などに成形したものを意味し、好ましくはシート状に成形されて吸収層となる。本発明に係る吸水性樹脂組成物の他に、パルプ繊維等の吸収性材料や接着剤や不織布などを成形に併用することもできる。この場合、吸収体（吸収層）中の吸水剤の量（以下、「コア濃度」と表記する）は、２０～１００質量％の範囲であることが好ましく、さらに好ましくは３０～９０質量％の範囲、より好ましくは４０～８０質量％の範囲である。コア濃度が２０質量％未満の場合は、吸水性樹脂組成物の使用量が少なく、例えば、オムツ全体への消臭性能の付与が十分に行われない場合があり、好ましくない。 The absorber means a sheet-shaped, fibrous, or tubular shape of a particulate water-absorbing agent, and is preferably molded into a sheet shape to form an absorbent layer. In addition to the water-absorbent resin composition according to the present invention, an absorbent material such as pulp fiber, an adhesive, a non-woven fabric, or the like can be used in combination for molding. In this case, the amount of the water-absorbing agent in the absorber (absorbent layer) (hereinafter referred to as "core concentration") is preferably in the range of 20 to 100% by mass, more preferably 30 to 90% by mass. The range is, more preferably 40 to 80% by mass. When the core concentration is less than 20% by mass, the amount of the water-absorbent resin composition used is small, and for example, the deodorizing performance may not be sufficiently imparted to the entire diaper, which is not preferable.
　本発明にかかる吸収体を吸水性樹脂組成物と親水性繊維とから製造する場合、その製造方法は特に限定されないが、例えば、吸水性樹脂組成物と親水性繊維とを、上述のコア濃度となる割合でミキサー等の混合機を用いて乾式混合し、得られた混合物を例えば空気抄造などによってウェブ状に成形した後、必要により圧縮成形して製造する方法が挙げられる。かかる吸収体は、密度０．００１～０．５０ｇ／ｃｃ、坪量０．０１～０．２０ｇ／ｃｍ２の範囲に圧縮成形されることが好ましい。 When the absorber according to the present invention is produced from the water-absorbent resin composition and the hydrophilic fiber, the production method thereof is not particularly limited, and for example, the water-absorbent resin composition and the hydrophilic fiber are used with the above-mentioned core concentration. Examples thereof include a method of dry mixing using a mixer such as a mixer at a certain ratio, molding the obtained mixture into a web shape by, for example, air injection, and then compression molding, if necessary. The absorber is preferably compression-molded to a density of 0.001 to 0.50 g / cc and a basis weight of 0.01 to 0.20 g / cm 2 .
　［５］　吸収性物品
　本発明に係る吸収性物品は、前記吸収体（吸収層）を含み、通常、液透過性を有する表面シートおよび液不透過性を有する背面シートを備える。吸収性物品として、使い捨てオムツや生理用ナプキン等が挙げられる。よって、本発明の一実施形態において、吸収体と、液透過性を有する表面シート、液不透過性を有する背面シートとを備える、吸収性物品が提供される。 [5] Absorbent Article The absorbent article according to the present invention includes the absorbent body (absorbent layer), and usually includes a liquid-permeable front sheet and a liquid-impermeable back sheet. Examples of the absorbent article include disposable diapers and sanitary napkins. Therefore, in one embodiment of the present invention, there is provided an absorbent article comprising an absorber, a liquid permeable surface sheet, and a liquid impermeable back sheet.
　吸収性物品が例えば使い捨てオムツである場合には、装着したときに人の肌に触れる側に位置する液透過性のトップシートと、装着したときに外側に位置する液不透過性のバックシートとの間に、本発明の一実施形態において、吸水剤を含む吸収体を挟持することにより、当該使い捨てオムツが作製される。なお、使い捨てオムツには、装着後の使い捨てオムツを固定するための粘着テープ等の、当業者にとって公知の部材がさらに設けられている。 When the absorbent article is, for example, a disposable diaper, a liquid-permeable top sheet located on the side that comes into contact with human skin when worn and a liquid-impermeable back sheet located on the outside when worn. In one embodiment of the present invention, the disposable diaper is produced by sandwiching an absorber containing a water-absorbing agent. The disposable diaper is further provided with a member known to those skilled in the art, such as an adhesive tape for fixing the disposable diaper after mounting.
　本発明に係る吸収性物品は、特定の吸水性樹脂組成物を含むため、従来よりも優れた消臭能を有する、新規な吸水性樹脂組成物を目的とする。 Since the absorbent article according to the present invention contains a specific water-absorbent resin composition, an object thereof is a novel water-absorbent resin composition having a deodorizing ability superior to that of the conventional one.
　なお、本発明に係る吸水性樹脂組成物は、前記使い捨てオムツや生理用ナプキン以外に、ペット尿吸収剤、携帯トイレの尿ゲル化剤等の用途にも、好適に利用することができる。さらに詳しくは、本発明は、紙おむつ、失禁パッド等の衛生材料を用いた場合に、優れた消臭性能、特に尿に起因する悪臭に対する優れた消臭性能を示す、吸水性樹脂組成物、吸収体、および吸収性物品に関する。 The water-absorbent resin composition according to the present invention can be suitably used not only for the disposable diapers and menstrual napkins, but also for pet urine absorbents, urine gelling agents for portable toilets, and the like. More specifically, the present invention is a water-absorbent resin composition, which exhibits excellent deodorizing performance, particularly excellent deodorizing performance against bad odors caused by urine, when sanitary materials such as disposable diapers and incontinence pads are used. Regarding the body and absorbent articles.
　以下、実施例および比較例によって本発明をより具体的に説明するが、本発明はこれら実施例および比較例に限定して解釈されるものではなく、各実施例に開示された技術的手段を適宜組み合わせて得られる実施例も本発明の範囲に含まれる。なお、実施例および比較例、並びに吸水剤の諸物性の測定で使用される電気機器は、特に注釈の無い限り、２００Ｖまたは１００Ｖ／６０Ｈｚの電源を使用している。吸水剤の諸物性は、特に注釈の無い限り、室温（２０℃～２５℃）、相対湿度５０±５％ＲＨの条件下で測定した。また、便宜上、「リットル」を「ｌ」または「Ｌ」、「質量％」を「ｗｔ％」と表記することがある。 Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples, and the technical means disclosed in each Example will be used. Examples obtained in appropriate combinations are also included in the scope of the present invention. Unless otherwise specified, the electrical equipment used in the examples and comparative examples and the measurement of various physical properties of the water absorbing agent uses a power supply of 200 V or 100 V / 60 Hz. Unless otherwise specified, the physical characteristics of the water-absorbing agent were measured under the conditions of room temperature (20 ° C to 25 ° C) and relative humidity of 50 ± 5% RH. Further, for convenience, "liter" may be expressed as "l" or "L", and "mass fraction" may be expressed as "wt%".
　［吸水性樹脂組成物の物性］
　以下、本発明に係る吸水性樹脂組成物の諸物性の測定方法に関して説明する。 [Physical characteristics of water-absorbent resin composition]
Hereinafter, a method for measuring various physical properties of the water-absorbent resin composition according to the present invention will be described.
　（ａ）スパン値
　吸水性樹脂組成物のスパン値は、ＥＤＡＮＡ法ＷＳＰ２２０．２の粒度分析法に準拠し、使用する篩を上から、目開き８５０μｍ、７１０μｍ、６００μｍ、５００μｍ、３００μｍ、１５０μｍ、４５μｍの順に組み合わせて使用し、以下の式によりスパン値を求めた。 (A) Span value The span value of the water-absorbent resin composition conforms to the particle size analysis method of EDANA method WSP220.2, and the sieve used is 850 μm, 710 μm, 600 μm, 500 μm, 300 μm, 150 μm, 45 μm from the top. The span value was calculated by the following formula.
Figure JPOXMLDOC01-appb-M000010
Figure JPOXMLDOC01-appb-M000010
　Ｄ（９０％）は、粒子径の累積粒径分布において、最小径からの累積が９０％となる粒子径（単位：μｍ）
　Ｄ（１０％）は、粒子径の累積粒径分布において、最小径からの累積が１０％となる粒子径（単位：μｍ）
　Ｄ（５０％）は、粒子径の累積粒径分布において、最小径からの累積が５０％となる粒子径（単位：μｍ）
　ここで、Ｄ（９０％）、Ｄ（１０％）、Ｄ（５０％）は、質量基準で累積した値である。 D (90%) is a particle size (unit: μm) in which the cumulative particle size distribution from the minimum diameter is 90%.
D (10%) is a particle size (unit: μm) in which the cumulative particle size distribution from the minimum diameter is 10%.
D (50%) is a particle size (unit: μm) in which the cumulative particle size distribution from the minimum diameter is 50%.
Here, D (90%), D (10%), and D (50%) are cumulative values on a mass basis.
　スパン値は上述のとおり、粉砕、分級、造粒等を適宜組み合わせることによって所望のスパン値となるように設定することができる。 As described above, the span value can be set to a desired span value by appropriately combining pulverization, classification, granulation and the like.
　（ｂ）質量平均粒子径Ｄ（５０％）
　吸水性樹脂組成物の質量平均粒子径Ｄ（５０％）は、ＥＤＡＮＡ法ＷＳＰ２２０．２の粒度分析法に準拠し、使用する篩を上から、目開き８５０μｍ、７１０μｍ、６００μｍ、５００μｍ、３００μｍ、１５０μｍ、４５μｍの順に組み合わせて使用して測定した。 (B) Mass average particle diameter D (50%)
The mass average particle size D (50%) of the water-absorbent resin composition conforms to the particle size analysis method of EDANA method WSP220.2, and the sieve used is 850 μm, 710 μm, 600 μm, 500 μm, 300 μm, 150 μm from the top. , 45 μm in combination and used for measurement.
　（ｃ）無加圧下吸収倍率（ＣＲＣ）
　吸水性樹脂および吸水性樹脂組成物のＣＲＣは、ＥＤＡＮＡ法ＷＳＰ２４１．３（１０）に準拠して測定した。 (C) Absorption factor under no pressurization (CRC)
The CRC of the water-absorbent resin and the water-absorbent resin composition was measured according to the EDANA method WSP241.3 (10).
　（ｄ）加圧下吸収倍率（ＡＡＰ）
　吸水性樹脂および吸水性樹脂組成物のＡＡＰは、ＥＤＡＮＡ法ＷＳＰ２４２．３（１０）に準拠して測定した。なお、荷重条件のみ４．８３ｋＰａに変更して測定した。 (D) Absorption rate under pressure (AAP)
The AAP of the water-absorbent resin and the water-absorbent resin composition was measured according to the EDANA method WSP242.3 (10). Only the load condition was changed to 4.83 kPa for measurement.
　（ｅ）消臭性能（消臭試験）
　複数の成人より集めた人尿５０ｍｌを蓋付きの２５０ｍｌのポリプロピレンカップに加え、そこに後述する実施例または比較例で得られた吸水性樹脂（または吸水性樹脂組成物）２．０ｇを添加することにより膨潤ゲルを形成させた。人尿は***後２時間以内のものを用いた。この容器に蓋をし、膨潤ゲルを３７℃に保った。液吸収から所定時間後に蓋を開け、カップの上部から約３ｃｍの位置で成人４名以上のパネラーが臭いをかぐことにより、消臭効果を判定した。判定は、下記の判定基準を用いて各人６段階で得点を記載し平均値を求めた。 (E) Deodorant performance (deodorant test)
50 ml of human urine collected from a plurality of adults is added to a 250 ml polypropylene cup with a lid, and 2.0 g of the water-absorbent resin (or water-absorbent resin composition) obtained in the Examples or Comparative Examples described later is added thereto. This formed a swelling gel. Human urine was used within 2 hours after excretion. The container was covered and the swollen gel was kept at 37 ° C. The lid was opened after a predetermined time from the liquid absorption, and the deodorizing effect was judged by the panelists of 4 or more adults smelling the odor at a position about 3 cm from the top of the cup. For the judgment, the score was described in 6 stages for each person using the following judgment criteria, and the average value was calculated.
Figure JPOXMLDOC01-appb-M000011
Figure JPOXMLDOC01-appb-M000011
　（ｆ）接触角
　ＳＵＳ板上に両面粘着テープを貼り、その上に吸水性樹脂組成物を撒き、両面テープに付着しなかった吸水性樹脂組成物を掻き落として表面が吸水性樹脂組成物で覆われた試料板を作成した。０．９０質量％生理食塩水を該試料板に接触させた時の接触角を、２０℃、６０％ＲＨの条件下、接触角計（協和界面科学（株）製，ＦＡＣＥ　ＣＡ－Ｘ型）を用いて液滴法にて測定した。０．９０質量％生理食塩水の液滴を試料板に滴下してから１秒後の接触角を１試料について５回測定し、その平均値を求めて吸水性樹脂組成物の接触角とした。 (F) Contact angle A double-sided adhesive tape is attached on a SUS plate, a water-absorbent resin composition is sprinkled on the double-sided adhesive tape, and the water-absorbent resin composition that did not adhere to the double-sided tape is scraped off to make the surface of the water-absorbent resin composition. A covered sample plate was created. Contact angle meter (FACE CA-X type manufactured by Kyowa Interface Science Co., Ltd.) with a contact angle of 0.90 mass% physiological saline in contact with the sample plate under the conditions of 20 ° C. and 60% RH. Was measured by the sessile drop method. The contact angle 1 second after dropping a droplet of 0.90 mass% physiological saline on the sample plate was measured 5 times for each sample, and the average value was calculated and used as the contact angle of the water-absorbent resin composition. ..
　［製造例１］
　単量体成分としてのアクリル酸ナトリウム（中和率７５モル％）の３３質量％水溶液５５００質量部に、内部架橋剤としてのポリエチレングリコールジアクリレート（ｎ＝８）８．７質量部を溶解させて反応液とした。 [Manufacturing Example 1]
8.7 parts by mass of polyethylene glycol diacrylate (n = 8) as an internal cross-linking agent is dissolved in 5500 parts by mass of a 33% by mass aqueous solution of sodium acrylate (75 mol% neutralization rate) as a monomer component. It was used as a reaction solution.
　次に、この反応液を窒素ガス雰囲気下で、３０分間脱気した。次いで、シグマ型羽根を２本有する内容積１０Ｌのジャケット付きステンレス製双碗型ニーダーに蓋を付けた反応器に前記反応液を供給し、反応液を３０℃に保ちながら前記反応器内を窒素ガス置換した。続いて、反応液を攪拌しながら過硫酸ナトリウム２．４質量部、及びＬ－アスコルビン酸０．１２質量部をそれぞれ水溶液にして添加したところ、凡そ１分後に重合が開始した。重合開始後、約２０分でピーク温度約８０℃となり、その後も攪拌を続けながら、重合を開始して６０分後に粒子状の含水ゲル状重合体を取り出した。 Next, this reaction solution was degassed for 30 minutes in a nitrogen gas atmosphere. Next, the reaction solution was supplied to a reactor having a lid on a stainless steel twin bowl type kneader with a jacket having an internal volume of 10 L and having two sigma type blades, and the inside of the reactor was filled with nitrogen while keeping the reaction solution at 30 ° C. Gas replacement. Subsequently, 2.4 parts by mass of sodium persulfate and 0.12 parts by mass of L-ascorbic acid were added as aqueous solutions while stirring the reaction solution, and the polymerization started after about 1 minute. About 20 minutes after the start of the polymerization, the peak temperature reached about 80 ° C., and 60 minutes after the start of the polymerization, the particulate hydrogel-like polymer was taken out while continuing stirring.
　当該粒子状含水ゲル状重合体の質量平均粒子径（Ｄ５０）を、国際公開公報「国際公開第２０１１／１２６０７９号パンフレット」記載の方法で測定したところ、約１８００μｍであった。 The mass average particle size (D50) of the particulate hydrogel polymer was measured by the method described in International Publication No. 2011/126079, and found to be about 1800 μm.
　得られた含水ゲル状重合体を目開き３００μｍの金網上に広げ、１５０℃で９０分間熱風乾燥した。 The obtained hydrogel-like polymer was spread on a wire mesh having an opening of 300 μm and dried with hot air at 150 ° C. for 90 minutes.
　次いで、乾燥物をロールミルを用いて粉砕し、さらに目開き６００μｍのＪＩＳ標準篩で分級、調合することにより、不定型破砕状の樹脂（ベースポリマー）（１）を得た。得られたベースポリマー（１）は、質量平均粒子径Ｄ（５０％）が３２８μｍ、８５０μｍを超える粒子割合が０．０質量％、７１０μｍ以上８５０μｍ未満の粒子割合が０．０質量％、６００μｍ以上７１０μｍ未満の粒子割合が１．４質量％、５００μｍ以上６００μｍ未満の粒子割合が６．１質量％、３００μｍ以上５００μｍ未満の粒子割合が５４．９質量％、１５０μｍ以上３００μｍ未満の粒子割合が３５．４質量％、４５μｍ以上１５０μｍ未満の粒子割合が２．１質量％、４５μｍ未満の粒子割合が０．１質量％であった。 Next, the dried product was pulverized using a roll mill, further classified and blended with a JIS standard sieve having an opening of 600 μm to obtain an atypical crushed resin (base polymer) (1). The obtained base polymer (1) has a mass average particle diameter D (50%) of 328 μm, a particle ratio of more than 850 μm is 0.0 mass%, and a particle ratio of 710 μm or more and less than 850 μm is 0.0 mass%, 600 μm or more. The particle ratio of less than 710 μm is 1.4% by mass, the particle ratio of 500 μm or more and less than 600 μm is 6.1% by mass, the particle ratio of 300 μm or more and less than 500 μm is 54.9% by mass, and the particle ratio of 150 μm or more and less than 300 μm is 35. The particle ratio of 4% by mass, 45 μm or more and less than 150 μm was 2.1% by mass, and the particle ratio of less than 45 μm was 0.1% by mass.
　次いで、前記のベースポリマー（１）１００質量部に対し、エチレングリコールジグリシジルエーテル０．０５質量部、プロピレングリコール１質量部、水３質量部と、イソプロピルアルコール１質量部からなる表面架橋剤を攪拌混合機で混合した。その後、前記の混合物を２１０℃で５０分間加熱処理することにより、表面架橋を行った。 Next, the surface cross-linking agent composed of 0.05 part by mass of ethylene glycol diglycidyl ether, 1 part by mass of propylene glycol, 3 parts by mass of water and 1 part by mass of isopropyl alcohol is stirred with respect to 100 parts by mass of the base polymer (1). It was mixed with a mixer. Then, the above mixture was heat-treated at 210 ° C. for 50 minutes to carry out surface cross-linking.
　次いで１．０質量％ジエチレントリアミン５酢酸・３ナトリウム水溶液３．０質量部を添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂（１）を得た。 Next, 3.0 parts by mass of 1.0 mass% diethylenetriamine 5 acetic acid / 3 sodium aqueous solution was added and mixed, and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin (1).
　［製造例２］
　製造例１で得られたベースポリマー（１）をさらにロールミルを用いて粉砕し、目開き１５０μｍの篩で分級、調合することにより、ベースポリマー（２）を得た。得られたベースポリマー（２）は、質量平均粒子径Ｄ（５０％）が３３０μｍ、８５０μｍを超える粒子割合が０．０質量％、７１０μｍ以上８５０μｍ未満の粒子割合が０．０質量％、６００μｍ以上７１０μｍ未満の粒子割合が０．７質量％、５００μｍ以上６００μｍ未満の粒子割合が４．７質量％、３００μｍ以上５００μｍ未満の粒子割合が５９．２質量％、１５０μｍ以上３００μｍ未満の粒子割合が３３．１質量％、４５μｍ以上１５０μｍ未満の粒子割合が２．２質量％、４５μｍ未満の粒子割合が０．１質量％であった。 [Manufacturing Example 2]
The base polymer (1) obtained in Production Example 1 was further pulverized using a roll mill, classified and blended with a sieve having an opening of 150 μm to obtain a base polymer (2). The obtained base polymer (2) has a mass average particle diameter D (50%) of 330 μm, a particle ratio of more than 850 μm is 0.0 mass%, and a particle ratio of 710 μm or more and less than 850 μm is 0.0 mass%, 600 μm or more. The particle ratio of less than 710 μm is 0.7% by mass, the particle ratio of 500 μm or more and less than 600 μm is 4.7% by mass, the particle ratio of 300 μm or more and less than 500 μm is 59.2% by mass, and the particle ratio of 150 μm or more and less than 300 μm is 33. The particle ratio of 1% by mass, 45 μm or more and less than 150 μm was 2.2% by mass, and the particle ratio of less than 45 μm was 0.1% by mass.
　次いで、前記のベースポリマー（２）１００質量部に対し、エチレングリコールジグリシジルエーテル０．０５質量部、プロピレングリコール１質量部、水３質量部と、イソプロピルアルコール１質量部からなる表面架橋剤を攪拌混合機で混合した。その後、前記の混合物を２１０℃で５０分間加熱処理することにより、表面架橋を行った。 Next, the surface cross-linking agent composed of 0.05 part by mass of ethylene glycol diglycidyl ether, 1 part by mass of propylene glycol, 3 parts by mass of water and 1 part by mass of isopropyl alcohol is stirred with respect to 100 parts by mass of the base polymer (2). It was mixed with a mixer. Then, the above mixture was heat-treated at 210 ° C. for 50 minutes to carry out surface cross-linking.
　次いで１．０質量％ジエチレントリアミン５酢酸・３ナトリウム水溶液３．０質量部を添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂（２）を得た。 Next, 3.0 parts by mass of 1.0 mass% diethylenetriamine 5 acetic acid / 3 sodium aqueous solution was added and mixed, and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin (2).
　［製造例３］
　製造例２で得られた吸水性樹脂（２）を、さらに目開き５００μｍ、１５０μｍの篩で分級し、調合することにより、吸水性樹脂（３）を得た。 [Manufacturing Example 3]
The water-absorbent resin (2) obtained in Production Example 2 was further classified by a sieve having an opening of 500 μm and 150 μm, and blended to obtain a water-absorbent resin (3).
　得られた吸水性樹脂（３）は、質量平均粒子径Ｄ（５０％）が３２４μｍ、８５０μｍを超える粒子割合が０．０質量％、７１０μｍ以上８５０μｍ未満の粒子割合が０．０質量％、６００μｍ以上７１０μｍ未満の粒子割合が０．０質量％、５００μｍ以上６００μｍ未満の粒子割合が０．１質量％、３００μｍ以上５００μｍ未満の粒子割合が７０．５質量％、１５０μｍ以上３００μｍ未満の粒子割合が２９．４質量％、４５μｍ以上１５０μｍ未満の粒子割合が０．０質量％、４５μｍ未満の粒子割合が０．０質量％であった。 The obtained water-absorbent resin (3) has a mass average particle diameter D (50%) of 324 μm, a particle ratio of more than 850 μm is 0.0% by mass, and a particle ratio of 710 μm or more and less than 850 μm is 0.0% by mass, 600 μm. The particle ratio of more than 710 μm is 0.0% by mass, the particle ratio of 500 μm or more and less than 600 μm is 0.1% by mass, the particle ratio of 300 μm or more and less than 500 μm is 70.5% by mass, and the particle ratio of 150 μm or more and less than 300 μm is 29. The particle ratio of 0.4% by mass, 45 μm or more and less than 150 μm was 0.0% by mass, and the particle ratio of less than 45 μm was 0.0% by mass.
　［製造例４］
　製造例１において、乾燥物をロールミルを用いて粉砕し、さらに目開き８５０μｍの篩で分級、調合することにより、ベースポリマー（４）を得た。 [Manufacturing Example 4]
In Production Example 1, the dried product was pulverized using a roll mill, further classified and blended with a sieve having an opening of 850 μm to obtain a base polymer (4).
　得られたベースポリマー（４）は、質量平均粒子径Ｄ（５０％）が３６１μｍ、８５０μｍを超える粒子割合が０．０質量％、７１０μｍ以上８５０μｍ未満の粒子割合が０．８質量％、６００μｍ以上７１０μｍ未満の粒子割合が１２．４質量％、５００μｍ以上６００μｍ未満の粒子割合が１４．８質量％、３００μｍ以上５００μｍ未満の粒子割合が３４．９質量％、１５０μｍ以上３００μｍ未満の粒子割合が２９．３質量％、４５μｍ以上１５０μｍ未満の粒子割合が７．５質量％、４５μｍ未満の粒子割合が０．３質量％であった。次いで、前記のベースポリマー（４）１００質量部に対し、エチレングリコールジグリシジルエーテル０．０５質量部、プロピレングリコール１質量部、水３質量部と、イソプロピルアルコール１質量部からなる表面架橋剤を攪拌混合機で混合した。その後、前記の混合物を２１０℃で５０分間加熱処理することにより、表面架橋を行った。
次いで１．０質量％ジエチレントリアミン５酢酸・３ナトリウム水溶液３．０質量部を添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂（４）を得た。 The obtained base polymer (4) has a mass average particle diameter D (50%) of 361 μm, a particle ratio of more than 850 μm is 0.0 mass%, and a particle ratio of 710 μm or more and less than 850 μm is 0.8 mass%, 600 μm or more. The particle ratio of less than 710 μm is 12.4% by mass, the particle ratio of 500 μm or more and less than 600 μm is 14.8% by mass, the particle ratio of 300 μm or more and less than 500 μm is 34.9% by mass, and the particle ratio of 150 μm or more and less than 300 μm is 29. The particle ratio of 3% by mass, 45 μm or more and less than 150 μm was 7.5% by mass, and the particle ratio of less than 45 μm was 0.3% by mass. Next, the surface cross-linking agent composed of 0.05 part by mass of ethylene glycol diglycidyl ether, 1 part by mass of propylene glycol, 3 parts by mass of water and 1 part by mass of isopropyl alcohol is stirred with respect to 100 parts by mass of the base polymer (4). It was mixed with a mixer. Then, the above mixture was heat-treated at 210 ° C. for 50 minutes to carry out surface cross-linking.
Then, 3.0 parts by mass of 1.0 mass% diethylenetriamine 5 acetic acid / 3 sodium aqueous solution was added and mixed, and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin (4).
　［製造例５］
　製造例１で得られたベースポリマー（１）１００質量部に対し、エチレングリコールジグリシジルエーテル０．０５質量部、水３質量部と、イソプロピルアルコール２質量部からなる表面架橋剤を攪拌混合機で混合した。その後、前記の混合物を２１０℃で５０分間加熱処理することにより、表面架橋を行った。次いで１．０質量％ジエチレントリアミン５酢酸・３ナトリウム水溶液３．０質量部を添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂（５）を得た。 [Manufacturing Example 5]
A surface cross-linking agent consisting of 0.05 parts by mass of ethylene glycol diglycidyl ether, 3 parts by mass of water and 2 parts by mass of isopropyl alcohol was mixed with 100 parts by mass of the base polymer (1) obtained in Production Example 1 with a stirring mixer. Mixed. Then, the above mixture was heat-treated at 210 ° C. for 50 minutes to carry out surface cross-linking. Then, 3.0 parts by mass of 1.0 mass% diethylenetriamine 5 acetic acid / 3 sodium aqueous solution was added and mixed, and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin (5).
　［製造例６］
　製造例１で得られたベースポリマー（１）１００質量部に対し、エチレングリコールジグリシジルエーテル０．０５質量部、プロピレングリコール１質量部、水３質量部と、イソプロピルアルコール１質量部からなる表面架橋剤を攪拌混合機で混合した。その後、前記の混合物を２１０℃で５０分間加熱処理することにより、表面架橋を行った。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂（６）を得た。 [Manufacturing Example 6]
Surface cross-linking consisting of 0.05 parts by mass of ethylene glycol diglycidyl ether, 1 part by mass of propylene glycol, 3 parts by mass of water, and 1 part by mass of isopropyl alcohol with respect to 100 parts by mass of the base polymer (1) obtained in Production Example 1. The agent was mixed with a stirring mixer. Then, the above mixture was heat-treated at 210 ° C. for 50 minutes to carry out surface cross-linking. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin (6).
　［実施例１］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、Ｃｈｒｏｍａｌｉｔｅ　ＰＣＧ６００Ｍ（ピュロライト株式会社製、スチレン系合成吸着剤、平均粒子径７０μｍ、比表面積７００ｍ２／ｇ、平均細孔直径１００Å）を０．１質量部（固形分換算）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（１）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９２質量％であった。 [Example 1]
Chromalite PCG600M (manufactured by Purolite Co., Ltd., styrene-based synthetic adsorbent, average particle diameter 70 μm, specific surface area 700 m 2 / g, average pores) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. 0.1 part by mass (in terms of solid content) was added and mixed (diameter 100 Å), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (1). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.92% by mass.
　［実施例２］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、Ｃｈｒｏｍａｌｉｔｅ　ＰＣＧ６００Ｍを０．５質量部（固形分換算）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（２）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９３質量％であった。 [Example 2]
To 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1, 0.5 parts by mass (solid content equivalent) of Chromalite PCG600M was added and mixed, and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (2). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.93% by mass.
　［実施例３］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、Ｃｈｒｏｍａｌｉｔｅ　ＰＣＧ６００Ｍを１．０質量部（固形分換算）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（３）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９６質量％であった。 [Example 3]
To 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1, 1.0 part by mass (solid content equivalent) of Chromalite PCG600M was added and mixed, and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (3). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.96% by mass.
　［実施例４］（バインダなし）
　製造例５で得られた、吸水性樹脂（５）を使用した以外、実施例３と同様にして吸水性樹脂組成物（４）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１に示した。 [Example 4] (without binder)
A water-absorbent resin composition (4) was obtained in the same manner as in Example 3 except that the water-absorbent resin (5) obtained in Production Example 5 was used. Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［実施例５］（キレート剤なし）
　製造例６で得られた、吸水性樹脂（６）を使用した以外、実施例３と同様にして吸水性樹脂組成物（５）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９５質量％であった。 [Example 5] (without chelating agent)
A water-absorbent resin composition (5) was obtained in the same manner as in Example 3 except that the water-absorbent resin (6) obtained in Production Example 6 was used. Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.95% by mass.
　［実施例６］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、Ｐｕｒｏｓｏｒｂ　ＰＡＤ６００ＦＭ（ピュロライト株式会社製、スチレン系合成吸着剤、平均粒子径２１０μｍ、比表面積８３０ｍ２／ｇ、平均細孔直径６３０Å）を０．５質量部（固形分換算）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（６）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９４質量％であった。 [Example 6]
Purosorb PAD600FM (manufactured by Purolite Co., Ltd., styrene-based synthetic adsorbent, average particle diameter 210 μm, specific surface area 830 m 2 / g, average pores) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. 0.5 parts by mass (in terms of solid content) was added and mixed (diameter 630 Å), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (6). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.94% by mass.
　［実施例７］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、Ｐｕｒｏｓｏｒｂ　ＰＡＤ６００（ピュロライト株式会社製、スチレン系合成吸着剤、平均粒子径４６０μｍ、比表面積８３０ｍ２／ｇ、平均細孔直径６３０Å）を０．５質量部（固形分換算）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（７）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９３質量％であった。 [Example 7]
Purosorb PAD600 (manufactured by Purolite Co., Ltd., styrene-based synthetic adsorbent, average particle diameter 460 μm, specific surface area 830 m 2 / g, average pores) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. 0.5 parts by mass (in terms of solid content) was added and mixed (diameter 630 Å), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (7). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.93% by mass.
　［実施例８］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、Ｐｕｒｏｓｏｒｂ　ＰＡＤ６１０（ピュロライト株式会社製、アクリル系合成吸着剤、平均粒子径４６０μｍ、比表面積４９０ｍ２／ｇ、平均細孔直径７００Å）を０．５質量部（固形分換算）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（８）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９６質量％であった。 [Example 8]
Purosorb PAD610 (manufactured by Purolite Co., Ltd., acrylic synthetic adsorbent, average particle diameter 460 μm, specific surface area 490 m 2 / g, average pores) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. 0.5 parts by mass (in terms of solid content) was added and mixed (diameter 700 Å), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (8). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.96% by mass.
　［実施例９］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、Ｄｉａｉｏｎ　２０ＨＰ（三菱ケミカル株式会社製、スチレン系合成吸着剤、平均粒子径３９０μｍ、比表面積５９０ｍ２／ｇ、平均細孔直径２９０Å）を０．５質量部（固形分換算）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（９）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９４質量％であった。 [Example 9]
Diaion 20HP (manufactured by Mitsubishi Chemical Co., Ltd., styrene-based synthetic adsorbent, average particle diameter 390 μm, specific surface area 590 m 2 / g, average fineness) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. 0.5 parts by mass (solid content equivalent) was added and mixed (hole diameter 290 Å), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (9). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.94% by mass.
　［実施例１０］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、Ｄｉａｉｏｎ　ＨＰ２ＭＧ（三菱ケミカル株式会社製、アクリル系合成吸着剤、平均粒子径６００μｍ、比表面積５７０ｍ２／ｇ、平均細孔直径２４０Å）を０．５質量部（固形分換算）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（１０）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９５質量％であった。 [Example 10]
Diaion HP2MG (manufactured by Mitsubishi Chemical Co., Ltd., acrylic synthetic adsorbent, average particle diameter 600 μm, specific surface area 570 m 2 / g, average fineness) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. 0.5 parts by mass (solid content equivalent) was added and mixed (hole diameter 240 Å), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (10). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.95% by mass.
　［実施例１１］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、Ｐｕｒｏｓｏｒｂ　ＰＡＤ３００（ピュロライト株式会社製、アクリル系合成吸着剤、平均粒子径４５０μｍ、比表面積９０ｍ２／ｇ、平均細孔直径２８０Å）を０．５質量部（固形分換算）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（１１）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９３質量％であった。 [Example 11]
Purosorb PAD300 (manufactured by Purolite Co., Ltd., acrylic synthetic adsorbent, average particle diameter 450 μm, specific surface area 90 m 2 / g, average pores) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. 0.5 parts by mass (in terms of solid content) was added and mixed (diameter 280 Å), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (11). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.93% by mass.
　［実施例１２］
　製造例２で得られた、吸水性樹脂（２）１００質量部に対して、Ｃｈｒｏｍａｌｉｔｅ　ＰＣＧ６００Ｍを０．５質量部（固形分換算）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（１２）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９６質量％であった。 [Example 12]
To 100 parts by mass of the water-absorbent resin (2) obtained in Production Example 2, 0.5 parts by mass (solid content equivalent) of Chromalite PCG600M was added and mixed, and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (12). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.96% by mass.
　［実施例１３］
　製造例３で得られた、吸水性樹脂（３）１００質量部に対して、Ｃｈｒｏｍａｌｉｔｅ　ＰＣＧ６００Ｍを０．５質量部（固形分換算）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（１３）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９４質量％であった。 [Example 13]
To 100 parts by mass of the water-absorbent resin (3) obtained in Production Example 3, 0.5 parts by mass (solid content equivalent) of Chromalite PCG600M was added and mixed, and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (13). Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.94% by mass.
　［実施例１４］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、４０質量％の水分散性エマルジョンＡ（スチレン／アクリル酸ブチル／２－イソプロペニル－２－オキサゾリン／ジビニルベンゼン＝５８．１／２１．８／２０．０／０．１質量％、ＬｏｇＰ＝３．２９、平均粒径：８０ｎｍ）を０．７５質量部（固形分換算で０．３質量部）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（１４）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９６質量％であった。 [Example 14]
40% by mass of water-dispersible emulsion A (styrene / butyl acrylate / 2-isopropenyl-2-oxazolin / divinylbenzene = 58) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. .1 / 21.8 / 20.0 / 0.1% by mass, LogP = 3.29, average particle size: 80 nm) was added and mixed in an amount of 0.75 parts by mass (0.3 parts by mass in terms of solid content). Further, the mixture was heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (14). Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.96% by mass.
　［実施例１５］
　水分散性エマルジョンＡを２．５質量部（固形分換算で１質量部）に変更した以外は、実施例１４と同様にして、吸水性樹脂組成物（１５）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９４質量％であった。 [Example 15]
A water-absorbent resin composition (15) was obtained in the same manner as in Example 14 except that the water-dispersible emulsion A was changed to 2.5 parts by mass (1 part by mass in terms of solid content). Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.94% by mass.
　［実施例１６］
　水分散性エマルジョンＡを７．５質量部（固形分換算で３質量部）に変更した以外は、実施例１４と同様にして、吸水性樹脂組成物（１６）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９６質量％であった。 [Example 16]
A water-absorbent resin composition (16) was obtained in the same manner as in Example 14 except that the water-dispersible emulsion A was changed to 7.5 parts by mass (3 parts by mass in terms of solid content). Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.96% by mass.
　［実施例１７］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、エポスターＳ（株式会社日本触媒製、トリアジン基含有ポリマー、平均粒子径０．２μｍ、２５℃のイオン交換水への溶解度は０質量％である）を０．３質量部添加混合し、その後、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（１７）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９３質量％であった。 [Example 17]
Epostel S (manufactured by Nippon Catalyst Co., Ltd., triazine group-containing polymer, average particle size 0.2 μm, ion-exchanged water at 25 ° C.) was added to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. (Solubility is 0% by mass) was added and mixed by 0.3 parts by mass, and then passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (17). Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.93% by mass.
　［実施例１８］
　エポスターＳ（株式会社日本触媒製、トリアジン基含有ポリマー、平均粒子径０．２μｍ、２５℃のイオン交換水への溶解度は０質量％である）を１質量部に変更した以外は、実施例１７と同様にして、吸水性樹脂組成物（１８）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９４質量％であった。 [Example 18]
Example 17 except that Epostal S (manufactured by Nippon Catalyst Co., Ltd., triazine group-containing polymer, average particle size 0.2 μm, solubility in ion-exchanged water at 25 ° C. is 0% by mass) was changed to 1 part by mass. In the same manner as above, a water-absorbent resin composition (18) was obtained. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.94% by mass.
　［実施例１９］
　エポスターＳ（株式会社日本触媒製、トリアジン基含有ポリマー、平均粒子径０．２μｍ、２５℃のイオン交換水への溶解度は０質量％である）を３質量部に変更した以外は、実施例１７と同様にして、吸水性樹脂組成物（１９）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９５質量％であった。 [Example 19]
Example 17 except that Epostal S (manufactured by Nippon Catalyst Co., Ltd., triazine group-containing polymer, average particle size 0.2 μm, solubility in ion-exchanged water at 25 ° C. is 0% by mass) was changed to 3 parts by mass. In the same manner as above, a water-absorbent resin composition (19) was obtained. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.95% by mass.
　［実施例２０］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、ポリ４－ビニルピリジン（Ｓｔｒｅｍ　Ｃｈｅｍｉｃａｌｓ，　Ｉｎｃ．製、ピリジン基含有ポリマー、２５０μｍ以下）を１質量部（固形分換算）添加混合し、その後、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（２０）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９６質量％であった。 [Example 20]
1 part by mass (solid content conversion) of poly4-vinylpyridine (made by Strem Chemicals, Inc., pyridine group-containing polymer, 250 μm or less) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. ) Was added and mixed, and then passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (20). Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.96% by mass.
　［実施例２１］（キレート剤なし）
　製造例６で得られた、吸水性樹脂（６）１００質量部に対して、水分散性エマルジョンＡを２．５質量部（固形分換算で１質量部）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（２１）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９４質量％であった。 [Example 21] (without chelating agent)
2.5 parts by mass (1 part by mass in terms of solid content) of the water-dispersible emulsion A is added and mixed with 100 parts by mass of the water-absorbent resin (6) obtained in Production Example 6, and the mixture is further mixed at 60 ° C. Was heated for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (21). Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.94% by mass.
　［実施例２２］（バインダなし）
　製造例５で得られた、吸水性樹脂（５）１００質量部に対して、エポスターＳ（株式会社日本触媒製、トリアジン基含有ポリマー、平均粒子径０．２μｍ、２５℃のイオン交換水への溶解度は０質量％である）を１質量部添加混合し、その後、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（２２）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Example 22] (without binder)
Epostel S (manufactured by Nippon Catalyst Co., Ltd., triazine group-containing polymer, average particle size 0.2 μm, ion-exchanged water at 25 ° C.) was added to 100 parts by mass of the water-absorbent resin (5) obtained in Production Example 5. (Solubility is 0% by mass) was added and mixed by 1 part by mass, and then passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (22). Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［実施例２３］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、水分散性エマルジョンＡを０．７５質量部（固形分換算で０．３質量部）添加混合し、その後Ｃｈｒｏｍａｌｉｔｅ　ＰＣＧ６００Ｍを０．５質量部（固形分換算）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（２３）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表３に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９４質量％であった。 [Example 23]
0.75 parts by mass (0.3 parts by mass in terms of solid content) of water-dispersible emulsion A was added and mixed with 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1, and then Chromalite PCG600M. Was added and mixed by 0.5 parts by mass (in terms of solid content), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (23). Table 3 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.94% by mass.
　［比較例１］
　製造例１で得られた吸水性樹脂（１）を、そのまま比較用吸水性樹脂組成物（１）として用いた。累積粒径およびスパン値、累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１および２に示した。 [Comparative Example 1]
The water-absorbent resin (1) obtained in Production Example 1 was used as it was as the water-absorbent resin composition (1) for comparison. Tables 1 and 2 show the cumulative particle size and span value, the cumulative particle size and span value, the deodorant test result, the CRC, and the AAP measurement result.
　［比較例２］
　製造例４で得られた、吸水性樹脂（４）１００質量部に対して、Ｃｈｒｏｍａｌｉｔｅ　ＰＣＧ６００Ｍを０．５質量部（固形分換算）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、比較用吸水性樹脂組成物（２）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１に示した。 [Comparative Example 2]
To 100 parts by mass of the water-absorbent resin (4) obtained in Production Example 4, 0.5 parts by mass (solid content equivalent) of Chromalite PCG600M was added and mixed, and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (2) for comparison. Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［比較例３］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、細孔構造を有しない微粒子であるエポスターＭＸ０２０Ｗ（日本触媒社製、スチレン－アクリル系微粒子、平均粒子径０．０２μｍ、理論比表面積３３３ｍ２／ｇ）を１．０質量部（固形分換算）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、比較用吸水性樹脂組成物（３）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１に示した。 [Comparative Example 3]
Eposter MX020W (styrene-acrylic fine particles manufactured by Nippon Shokubai Co., Ltd., average particle diameter 0.02 μm), which is fine particles having no pore structure with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. , Theoretical specific surface area (333 m 2 / g) was added and mixed in an amount of 1.0 part by mass (in terms of solid content), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (3) for comparison. Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［比較例４］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、ＨＳＺ－５００ＫＯＡ（東ソー株式会社製、Ｌ型ゼオライト、ＳｉＯ２／Ａｌ２Ｏ３＝６．１（ｍｏｌ／ｍｏｌ）、平均粒子径３μｍ、比表面積２９０ｍ２／ｇ、平均細孔直径８Å）を１．０質量部（固形分換算）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、比較用吸水性樹脂組成物（４）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１に示した。 [Comparative Example 4]
HSZ-500KOA (manufactured by Tosoh Corporation, L-type zeolite, SiO 2 / Al 2 O 3 = 6.1 (mol / mol)) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. , Average particle diameter 3 μm, specific surface area 290 m 2 / g, average pore diameter 8 Å) were added and mixed in an amount of 1.0 part by mass (in terms of solid content), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (4) for comparison. Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［比較例５］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、ペルオキシ一硫酸カリウム（Ａｌｄｒｉｃｈ社製、製品名ＯＸＯＮＥ）を０．５質量部（固形分換算）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、比較用吸水性樹脂組成物（５）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表１に示した。 [Comparative Example 5]
To 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1, 0.5 part by mass (solid content equivalent) of potassium peroxymonosulfate (manufactured by Aldrich, product name OXONE) was added and mixed, and further. The mixture was heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (5) for comparison. Table 1 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［比較例６］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、３０質量％のエポミンＰ－１０００（株式会社日本触媒製、水溶性ポリエチレンイミン（含窒素非複素環樹脂））の水溶液を３．３質量部（固形分換算で１質量部）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、比較用吸水性樹脂組成物（６）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Comparative Example 6]
30% by mass of Epomin P-1000 (water-soluble polyethyleneimine (nitrogen-containing non-homogeneous ring resin) manufactured by Nippon Catalyst Co., Ltd.) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. The aqueous solution was added and mixed by 3.3 parts by mass (1 part by mass in terms of solid content), and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (6) for comparison. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［比較例７］
　水分散性エマルジョンＡ添加混合後の加熱温度を１５０℃に変更した以外は、実施例１４と同様にして、比較用吸水性樹脂組成物（７）を得た。 [Comparative Example 7]
A water-absorbent resin composition (7) for comparison was obtained in the same manner as in Example 14 except that the heating temperature after adding and mixing the water-dispersible emulsion A was changed to 150 ° C.
　［実施例２４］
　製造例１で得られた、吸水性樹脂（１）１００質量部に対して、２５質量％の水溶性ポリマーＢ（２－イソプロペニル－２－オキサゾリン／アクリル酸エチル／メタクリル酸メチル／メトキシポリエチレングリコールアクリレート（ｎ＝９）＝５０／２２／３／２５質量％、重量平均分子量＝約４０，０００、ＬｏｇＰ＝１．０７）の水溶液を４質量部（固形分換算で１質量部）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（２４）を得た。消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。なお、当該吸水性樹脂組成物中に含まれるバインダの量は、０．９５質量％であった。 [Example 24]
25% by mass of water-soluble polymer B (2-isopropenyl-2-oxazoline / ethyl acrylate / methyl methacrylate / methoxypolyethylene glycol) with respect to 100 parts by mass of the water-absorbent resin (1) obtained in Production Example 1. An aqueous solution of acrylate (n = 9) = 50/22/3/25% by mass, weight average molecular weight = about 40,000, LogP = 1.07) was added and mixed in an amount of 4 parts by mass (1 part by mass in terms of solid content). Further, the mixture was heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (24). Table 2 shows the deodorization test results, CRC, and AAP measurement results. The amount of the binder contained in the water-absorbent resin composition was 0.95% by mass.
　［製造例７］
　アクリル酸（２１６．２ｇ）に、内部架橋剤である１０質量％ポリエチレングリコールジアクリレート（重量平均分子量；５２３）水溶液（３．９２ｇ）、および、キレート剤である２０質量％エチレンジアミン四酢酸二ナトリウム水溶液（０．６６ｇ）を添加した溶液（Ａ）と、４８．５質量％の水酸化ナトリウム水溶液（１８０．６ｇ）を５０℃に調温した脱イオン水（２０９．８ｇ）で希釈した溶液（Ｂ）とを、容量１．５Ｌ、内径８０ｍｍのポリプロピレン製の容器にそれぞれ調製した。マグネチックスターラーを用いて上記溶液（Ａ）を攪拌しながら、上記溶液（Ｂ）を加えて混合することで、溶液（Ｃ）を調製した。 [Manufacturing Example 7]
Acrylic acid (216.2 g), a 10 mass% polyethylene glycol diacrylate (weight average molecular weight; 523) aqueous solution (3.92 g) as an internal cross-linking agent, and a 20 mass% ethylene diamine tetraacetate disodium aqueous solution as a chelating agent. A solution (A) to which (0.66 g) was added and a solution (B) obtained by diluting a 48.5 mass% sodium hydroxide aqueous solution (180.6 g) with deionized water (209.8 g) whose temperature was adjusted to 50 ° C. ) And were prepared in a polypropylene container having a capacity of 1.5 L and an inner diameter of 80 mm, respectively. The solution (C) was prepared by adding and mixing the solution (B) while stirring the solution (A) using a magnetic stirrer.
　その後、上記溶液（Ｃ）の攪拌を継続し、溶液（Ｃ）の温度が９５℃となった時点（＝重合開始温度）で、溶液（Ｃ）に、重合開始剤として１０質量％の過硫酸ナトリウム水溶液（３．６ｇ）を加えて、約３秒間攪拌し、単量体水溶液（７）とした。 After that, stirring of the above solution (C) was continued, and when the temperature of the solution (C) reached 95 ° C. (= polymerization initiation temperature), 10% by mass of persulfuric acid was added to the solution (C) as a polymerization initiator. An aqueous sodium solution (3.6 g) was added, and the mixture was stirred for about 3 seconds to obtain a monomer aqueous solution (7).
　次に、上記単量体水溶液（７）をバット型容器に、大気開放系で流し込んだ。なお、当該バット型容器は、底面の大きさが２５０ｍｍ×２５０ｍｍ、上面の大きさが６４０ｍｍ×６４０ｍｍ、高さが５０ｍｍ、中心断面が台形状であり、内面にテフロン（商標）シートを貼付した容器であった。また、当該バット型容器は、１００℃に加熱されたホットプレート上に載置し、プレヒートしておいた。上記単量体水溶液（７）を上記バット型容器に流し込んだ後、約５秒後に重合反応が開始した。当該重合反応は、水蒸気を発生しながら上方に向かって単量体水溶液（７）が四方八方に膨張、発泡しながら進行した後、バット型容器の底面より若干大きいサイズにまで、得られた含水ゲル（７）が収縮して終了した。なお、当該重合反応（膨張、収縮）は約１分間以内に終了したが、その後、２分間はバット型容器内に含水ゲル（７）の状態を保持した。当該重合反応によって、気泡を含む含水ゲル（７）を得た。 Next, the above-mentioned monomer aqueous solution (7) was poured into a vat-shaped container in an open system to the atmosphere. The butt-shaped container has a bottom surface size of 250 mm × 250 mm, a top surface size of 640 mm × 640 mm, a height of 50 mm, a trapezoidal central cross section, and a Teflon (trademark) sheet attached to the inner surface. Met. Further, the vat-shaped container was placed on a hot plate heated to 100 ° C. and preheated. After the above-mentioned monomer aqueous solution (7) was poured into the above-mentioned vat-shaped container, the polymerization reaction started about 5 seconds later. The polymerization reaction proceeded while the monomer aqueous solution (7) expanded and foamed upward while generating water vapor, and then the water content was obtained to a size slightly larger than the bottom surface of the bat-shaped container. The gel (7) shrank and finished. The polymerization reaction (expansion and contraction) was completed within about 1 minute, but the state of the hydrogel (7) was maintained in the bat-shaped container for 2 minutes thereafter. The polymerization reaction gave a hydrogel (7) containing bubbles.
　次に、上記重合反応で得られた含水ゲル（７）を１６等分した後、多孔板を有する卓上型ミートチョッパー（ＭＥＡＴ－ＣＨＯＰＰＥＲ　ＴＹＰＥ：１２ＶＲ－４００ＫＳＯＸ、飯塚工業株式会社製）を用い、含水ゲルの投入と同時に、２５℃の０．２質量％の亜硫酸水素ナトリウム水溶液を含水ゲルに、含水ゲルの固形分１００質量部（２６５ｇ）に対して２５質量部添加しながらゲル粉砕を行い、粒子状含水ゲル（７）を得た。 Next, the water-containing gel (7) obtained by the above polymerization reaction was divided into 16 equal parts, and then a tabletop meat chopper (MEAT-CHOPPER TYPE: 12VR-400KSOX, manufactured by Iizuka Kogyo Co., Ltd.) having a porous plate was used to contain water. Simultaneously with the addition of the gel, gel pulverization was performed while adding 25 parts by mass of 0.2% by mass sodium hydrogen sulfite aqueous solution at 25 ° C. to the water-containing gel with respect to 100 parts by mass (265 g) of the solid content of the water-containing gel. A hydrous gel (7) was obtained.
　次に、上記粒子状含水ゲル（７）４５０ｇを目開き３００μｍ（５０メッシュ）の金網上に広げて載せ、静置乾燥機内（通気流回分乾燥機７１－Ｓ６型（サタケ化学機械工業（株）　製））を用いて１８０℃で３０分間乾燥することで、粒子状の乾燥重合体（７）を得た。 Next, 450 g of the particulate hydrogel (7) was spread on a wire mesh having a mesh size of 300 μm (50 mesh) and placed in a static dryer (ventilation flow batch dryer 71-S6 type (Satake Chemical Machinery Co., Ltd.). The dry polymer (7) in the form of particles was obtained by drying at 180 ° C. for 30 minutes using (manufactured by).
　続いて、当該乾燥重合体（７）をロールミル（ＷＭＬ型ロール粉砕機、有限会社井ノ口技研社製）に投入して粉砕し、その後、目開き１５０μｍのＪＩＳ標準篩を用いて当該篩を通過する粒子を分級することにより、微粉状の吸水性樹脂（７）を得た。 Subsequently, the dried polymer (7) is put into a roll mill (WML type roll crusher, manufactured by Inoguchi Giken Co., Ltd.) and pulverized, and then passed through the sieve using a JIS standard sieve having an opening of 150 μm. By classifying the particles, a fine powdery water-absorbent resin (7) was obtained.
　次に、微粉状の吸水性樹脂（７）３００ｇを８０℃のウォーターバスで保温された５Ｌモルタルミキサー（西日本試験機製作所製）に入れ、該モルタルミキサーの攪拌羽根を６０Ｈｚ／１００Ｖで高速回転させながら、造粒用の水性液としての０．０５質量％過酸化水素水溶液３００ｇを８０℃に加熱しておいたのちに一気に投入した。投入から１０秒以内に微粉状の吸水性樹脂（７）と水とは混合されて造粒物となり、投入から１分後に取り出すことにより、造粒ゲル（７）を得た。 Next, 300 g of the finely powdered water-absorbent resin (7) was placed in a 5 L mortar mixer (manufactured by Nishinihon Testing Machine Co., Ltd.) kept warm in a water bath at 80 ° C., and the stirring blade of the mortar mixer was rotated at high speed at 60 Hz / 100 V. However, 300 g of a 0.05 mass% hydrogen peroxide aqueous solution as an aqueous solution for granulation was heated to 80 ° C. and then added at once. Within 10 seconds after charging, the finely powdered water-absorbent resin (7) and water were mixed to form a granulated product, which was taken out 1 minute after charging to obtain a granulated gel (7).
　［製造例８］
　製造例７と同じ条件の重合とゲル粉砕を繰り返し行い、粒子状含水ゲル（８）を得た。 [Manufacturing Example 8]
Polymerization and gel pulverization under the same conditions as in Production Example 7 were repeated to obtain a particulate hydrogel (8).
　次に、上記粒子状含水ゲル（８）３６０ｇと製造例７で得られた造粒ゲル（７）９０ｇを併せて目開き３００μｍ（５０メッシュ）の金網上に広げて載せ、静置乾燥機内（通気流回分乾燥機７１－Ｓ６型（サタケ化学機械工業（株）　製））を用いて１８０℃で３０分間乾燥することで、粒子状の乾燥重合体（７）を得た。 Next, 360 g of the particulate water-containing gel (8) and 90 g of the granulated gel (7) obtained in Production Example 7 were spread together on a wire net having an opening of 300 μm (50 mesh) and placed in a static dryer (in a static dryer). A particulate dry polymer (7) was obtained by drying at 180 ° C. for 30 minutes using an aeration flow batch dryer 71-S6 type (manufactured by Satake Chemical Machinery Co., Ltd.).
　続いて、当該乾燥重合体（８）をロールミル（ＷＭＬ型ロール粉砕機、有限会社井ノ口技研社製）に投入して粉砕し、その後、目開き８５０μｍおよび１５０μｍの二種類のＪＩＳ標準篩を用いて、ロータップ式篩分級機で分級することで、不定形破砕状の吸水性樹脂（８）を得た。 Subsequently, the dried polymer (8) was put into a roll mill (WML type roll crusher, manufactured by Inoguchi Giken Co., Ltd.) and crushed, and then using two types of JIS standard sieves with a mesh size of 850 μm and 150 μm. By classifying with a low-tap type sieve classifier, an amorphous crushed water-absorbent resin (8) was obtained.
　次に、エチレングリコールジグリシジルエーテル（商品名：デナコールＥＸ－８１０、ナガセケムテックス社製、０．０２５質量部）、プロピレングリコール（１．３５質量部）、脱イオン水（３．１５質量部）からなる表面架橋剤溶液（８）を、上記不定形破砕状の吸水性樹脂（８）（１００質量部）に添加し、スパチュラで均一になるまで混合することで、加湿混合物（８）を得た。続いて、当該加湿混合物（８）をステンレス製の容器に均一に入れ、１８０℃で４０分間加熱処理し、表面架橋された吸水性樹脂（８）を得た。 Next, ethylene glycol diglycidyl ether (trade name: Denacol EX-810, manufactured by Nagase ChemteX, 0.025 parts by mass), propylene glycol (1.35 parts by mass), deionized water (3.15 parts by mass). The surface cross-linking agent solution (8) composed of the above is added to the amorphous crushed water-absorbent resin (8) (100 parts by mass) and mixed with a spatula until uniform to obtain a humidified mixture (8). rice field. Subsequently, the humidified mixture (8) was uniformly placed in a stainless steel container and heat-treated at 180 ° C. for 40 minutes to obtain a surface-crosslinked water-absorbent resin (8).
　次いで２．５質量％亜硫酸水素ナトリウム水溶液２．０質量部を添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂（８）を得た。 Next, 2.0 parts by mass of a 2.5 mass% sodium bisulfite aqueous solution was added and mixed, and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin (8).
　［製造例９］
　製造例７において、重合で添加する２０質量％エチレンジアミン四酢酸二ナトリウム水溶液を２．６４ｇとし、ゲル粉砕で添加する亜硫酸水素ナトリウム水溶液を脱イオン水とし、微粉造粒で投入する過酸化水素水溶液の濃度を０．１質量％としたこと以外は、製造例７と同様にして、造粒ゲル（９）を得た。 [Manufacturing Example 9]
In Production Example 7, the 20% by mass ethylenediamine disodium tetraacetate aqueous solution added by polymerization is 2.64 g, the sodium bisulfite aqueous solution added by gel pulverization is deionized water, and the hydrogen peroxide aqueous solution added by fine powder granulation is used. A granulated gel (9) was obtained in the same manner as in Production Example 7 except that the concentration was 0.1% by mass.
　［製造例１０］
　製造例８において、重合で添加する２０質量％エチレンジアミン四酢酸二ナトリウム水溶液を２．６４ｇとし、ゲル粉砕で添加する亜硫酸水素ナトリウム水溶液を脱イオン水とし、粒子状含水ゲルと併せる造粒ゲルを製造例９で得られた造粒ゲル（９）とし、表面架橋後に添加する亜硫酸水素ナトリウム水溶液の濃度を５．０質量％としたこと以外は、製造例８と同様にして、吸水性樹脂（１０）を得た。 [Manufacturing Example 10]
In Production Example 8, a granulated gel is produced by using 2.64 g of a 20% by mass ethylenediamine tetraacetate disodium aqueous solution added by polymerization and using deionized water as a sodium bisulfite aqueous solution added by gel grinding. The water-absorbent resin (10) was obtained in the same manner as in Production Example 8 except that the granulated gel (9) obtained in Example 9 was used and the concentration of the sodium bisulfite aqueous solution added after surface cross-linking was 5.0% by mass. ) Was obtained.
　［製造例１１］
　製造例９において、重合で添加するキレート剤を２０質量％ジエチレントリアミン５酢酸三ナトリウム水溶液としたこと以外は、製造例９と同様にして、造粒ゲル（１１）を得た。 [Manufacturing Example 11]
Granulation gel (11) was obtained in the same manner as in Production Example 9 except that the chelating agent added by polymerization was a 20% by mass diethylenetriamine-5 trisodium acetate aqueous solution.
　［製造例１２］
　製造例１０において、重合で添加するキレート剤を２０質量％ジエチレントリアミン５酢酸三ナトリウム水溶液とし、粒子状含水ゲルと併せる造粒ゲルを製造例１１で得られた造粒ゲル（１１）とし、表面架橋後に添加する亜硫酸水素ナトリウム水溶液の濃度を７．５質量％としたこと以外は、製造例１０と同様にして、吸水性樹脂（１２）を得た。 [Manufacturing Example 12]
In Production Example 10, the chelating agent added by polymerization is a 20 mass% diethylenetriamine 5-sodium acetate aqueous solution, and the granulation gel combined with the particulate water-containing gel is the granulation gel (11) obtained in Production Example 11, and surface cross-linking is performed. A water-absorbent resin (12) was obtained in the same manner as in Production Example 10 except that the concentration of the sodium bisulfite aqueous solution to be added later was 7.5% by mass.
　［製造例１３］
　製造例１１において、重合で添加する２０質量％エチレンジアミン四酢酸二ナトリウム水溶液を１．３２ｇとし、微粉造粒で投入する０．１質量％過酸化水素水溶液を０．２質量％亜硫酸水素ナトリウム水溶液としたこと以外は、製造例１１と同様にして、造粒ゲル（１３）を得た。 [Manufacturing Example 13]
In Production Example 11, the 20% by mass ethylenediamine tetraacetate disodium aqueous solution added by polymerization was 1.32 g, and the 0.1% by mass hydrogen peroxide solution added by fine powder granulation was used as 0.2% by mass sodium bisulfite aqueous solution. Granulation gel (13) was obtained in the same manner as in Production Example 11.
　［製造例１４］
　製造例１２において、重合で添加する２０質量％エチレンジアミン四酢酸二ナトリウム水溶液を１．３２ｇとし、粒子状含水ゲルと併せる造粒ゲルを製造例１３で得られた造粒ゲル（１３）とし、表面架橋後に添加する亜硫酸水素ナトリウム水溶液の濃度を５．０質量％としたこと以外は、製造例１２と同様にして、吸水性樹脂（１４）を得た。 [Manufacturing Example 14]
In Production Example 12, the 20% by mass ethylenediamine tetraacetate disodium aqueous solution added by polymerization was 1.32 g, and the granulation gel to be combined with the particulate water-containing gel was the granulation gel (13) obtained in Production Example 13 on the surface. A water-absorbent resin (14) was obtained in the same manner as in Production Example 12, except that the concentration of the sodium bisulfite aqueous solution added after crosslinking was 5.0% by mass.
　［製造例１５］
　製造例１３において、重合で添加するエチレンジアミン四酢酸二ナトリウム水溶液の濃度を１．０質量％とし、微粉造粒で投入する亜硫酸水素ナトリウム水溶液を亜硫酸ナトリウム水溶液としたこと以外は、製造例１３と同様にして、造粒ゲル（１５）を得た。 [Manufacturing Example 15]
Same as Production Example 13 except that the concentration of the aqueous solution of disodium ethylenediamine tetraacetate added by polymerization was 1.0% by mass and the aqueous solution of sodium hydrogen sulfite added by fine powder granulation was the aqueous solution of sodium sulfite. A granulated gel (15) was obtained.
　［製造例１６］
　製造例１４において、重合で添加するエチレンジアミン四酢酸二ナトリウム水溶液の濃度を１．０質量％とし、粒子状含水ゲルと併せる造粒ゲルを製造例１５で得られた造粒ゲル（１５）とし、表面架橋後に添加する亜硫酸水素ナトリウム水溶液を亜硫酸ナトリウム水溶液としたこと以外は、製造例１４と同様にして、吸水性樹脂（１６）を得た。 [Manufacturing Example 16]
In Production Example 14, the concentration of the aqueous solution of ethylene diamine tetraacetate disodium added by polymerization was set to 1.0% by mass, and the granulation gel to be combined with the particulate water-containing gel was referred to as the granulation gel (15) obtained in Production Example 15. A water-absorbent resin (16) was obtained in the same manner as in Production Example 14, except that the sodium hydrogen sulfite aqueous solution added after the surface cross-linking was changed to the sodium sulfite aqueous solution.
　［製造例１７］
　製造例７において、重合で添加する１０質量％ポリエチレングリコールジアクリレート（重量平均分子量；５２３）水溶液を２．０４ｇ、２０質量％エチレンジアミン四酢酸二ナトリウム水溶液を３．９７ｇ、脱イオン水を２４６．３ｇとし、ゲル粉砕で添加する亜硫酸水素ナトリウム水溶液の濃度を１．０質量％とし、微粉造粒で投入する過酸化水素水溶液の濃度を０．３質量％としたこと以外は、製造例７と同様にして、造粒ゲル（１７）を得た。 [Manufacturing Example 17]
In Production Example 7, 2.04 g of a 10 mass% polyethylene glycol diacrylate (weight average molecular weight; 523) aqueous solution added by polymerization, 3.97 g of a 20 mass% ethylenediamine disodium tetraacetate aqueous solution, and 246.3 g of deionized water. The same as in Production Example 7 except that the concentration of the aqueous sodium hydrogen sulfite solution added by gel pulverization was 1.0% by mass and the concentration of the aqueous solution of hydrogen peroxide added by fine powder granulation was 0.3% by mass. A granulated gel (17) was obtained.
　［製造例１８］
　製造例８において、重合で添加する１０質量％ポリエチレングリコールジアクリレート（重量平均分子量；５２３）水溶液を２．０４ｇ、２０質量％エチレンジアミン四酢酸二ナトリウム水溶液を３．９７ｇ、脱イオン水を２４６．３ｇとし、ゲル粉砕で添加する亜硫酸水素ナトリウム水溶液の濃度を１．０質量％とし、粒子状含水ゲルと併せる造粒ゲルを製造例１７で得られた造粒ゲル（１７）としたこと以外は、製造例８と同様にして、吸水性樹脂（１８）を得た。 [Manufacturing Example 18]
In Production Example 8, 2.04 g of a 10 mass% polyethylene glycol diacrylate (weight average molecular weight; 523) aqueous solution, 3.97 g of a 20 mass% ethylene diamine disodium tetraacetate aqueous solution, and 246.3 g of deionized water added by polymerization. Except that the concentration of the aqueous sodium hydrogen sulfite solution added by gel pulverization was 1.0% by mass, and the granulation gel to be combined with the particulate hydrogel was the granulation gel (17) obtained in Production Example 17. A water-absorbent resin (18) was obtained in the same manner as in Production Example 8.
　［製造例１９］
　製造例１７において、重合で添加する２０質量％エチレンジアミン四酢酸二ナトリウム水溶液を１．３２ｇとし、ゲル粉砕で添加する亜硫酸水素ナトリウム水溶液の濃度を１．２質量％とし、微粉造粒で投入する過酸化水素水溶液の濃度を０．２質量％としたこと以外は、製造例１７と同様にして、造粒ゲル（１９）を得た。 [Manufacturing Example 19]
In Production Example 17, the concentration of the 20% by mass ethylenediamine disodium tetraacetate aqueous solution added by polymerization is 1.32 g, the concentration of the sodium bisulfite aqueous solution added by gel pulverization is 1.2% by mass, and the mixture is added by fine powder granulation. A granulated gel (19) was obtained in the same manner as in Production Example 17, except that the concentration of the aqueous hydrogen oxide solution was 0.2% by mass.
　［製造例２０］
　製造例１８において、重合で添加する２０質量％エチレンジアミン四酢酸二ナトリウム水溶液を１．３２ｇとし、ゲル粉砕で添加する亜硫酸水素ナトリウム水溶液の濃度を１．２質量％とし、粒子状含水ゲルと併せる造粒ゲルを製造例１９で得られた造粒ゲル（１９）とし、表面架橋後に添加する亜硫酸水素ナトリウム水溶液を脱イオン水としたこと以外は、製造例１８と同様にして、吸水性樹脂（２０）を得た。 [Manufacturing Example 20]
In Production Example 18, the concentration of the 20% by mass ethylenediamine tetraacetate disodium aqueous solution added by polymerization was 1.32 g, and the concentration of the sodium bisulfite aqueous solution added by gel grinding was 1.2% by mass, and the mixture was combined with the particulate water-containing gel. The water-absorbent resin (20) was the same as in Production Example 18 except that the granule gel was the granulated gel (19) obtained in Production Example 19 and the sodium bisulfite aqueous solution added after surface cross-linking was deionized water. ) Was obtained.
　［製造例２１］
　製造例１７において、重合で添加するキレート剤を２０質量％エチレンジアミンテトラメチレンホスホン酸５ナトリウム水溶液０．６６ｇとしたこと以外は、製造例１７と同様にして、造粒ゲル（２１）を得た。 [Manufacturing Example 21]
A granulated gel (21) was obtained in the same manner as in Production Example 17 except that the chelating agent added by polymerization was 0.66 g of a 20 mass% ethylenediaminetetramethylenephosphonic acid 5 sodium aqueous solution.
　［製造例２２］
　製造例１８において、重合で添加するキレート剤を２０質量％エチレンジアミンテトラメチレンホスホン酸５ナトリウム水溶液０．６６ｇとし、粒子状含水ゲルと併せる造粒ゲルを製造例２１で得られた造粒ゲル（２１）としたこと以外は、製造例１８と同様にして、吸水性樹脂（２２）を得た。 [Manufacturing Example 22]
In Production Example 18, the chelating agent added by polymerization was 0.66 g of a 20 mass% ethylenediaminetetramethylenephosphonic acid 5 sodium aqueous solution, and a granulation gel to be combined with a particulate hydrogel was obtained in Production Example 21. A water-absorbent resin (22) was obtained in the same manner as in Production Example 18.
　［製造例２３］
　製造例２１において、重合で添加する２０質量％エチレンジアミンテトラメチレンホスホン酸５ナトリウム水溶液を３．９７ｇとし、ゲル粉砕で添加する亜硫酸水素ナトリウム水溶液の濃度を０．８質量％とし、微粉造粒で投入する０．３質量％過酸化水素水溶液を０．２質量％亜硫酸水素ナトリウム水溶液としたこと以外は、製造例２１と同様にして、造粒ゲル（２３）を得た。 [Manufacturing Example 23]
In Production Example 21, the 20% by mass ethylenediaminetetramethylenephosphonic acid 5 sodium aqueous solution added by polymerization was 3.97 g, the concentration of the sodium bisulfite aqueous solution added by gel pulverization was 0.8% by mass, and the mixture was added by fine powder granulation. A granulated gel (23) was obtained in the same manner as in Production Example 21 except that the 0.3% by mass aqueous hydrogen peroxide solution was changed to a 0.2% by mass sodium bisulfite aqueous solution.
　［製造例２４］
　製造例２２において、重合で添加する２０質量％エチレンジアミンテトラメチレンホスホン酸５ナトリウム水溶液を３．９７ｇとし、ゲル粉砕で添加する亜硫酸水素ナトリウム水溶液の濃度を０．８質量％とし、粒子状含水ゲルと併せる造粒ゲルを製造例２３で得られた造粒ゲル（２３）とし、表面架橋後に添加する亜硫酸水素ナトリウム水溶液の濃度を１．２５質量％としたこと以外は、製造例２２と同様にして、吸水性樹脂（２４）を得た。 [Manufacturing Example 24]
In Production Example 22, the 20% by mass ethylenediaminetetramethylenephosphonic acid 5 sodium aqueous solution added by polymerization was 3.97 g, and the concentration of the sodium bisulfite aqueous solution added by gel grinding was 0.8% by mass. The granulation gel to be combined was the granulation gel (23) obtained in Production Example 23, and the same as in Production Example 22 except that the concentration of the sodium bisulfite aqueous solution added after the surface cross-linking was 1.25% by mass. , A water-absorbent resin (24) was obtained.
　［製造例２５］
　製造例２３において、重合で添加する２０質量％エチレンジアミンテトラメチレンホスホン酸５ナトリウム水溶液を１．３２ｇとし、ゲル粉砕で添加する亜硫酸水素ナトリウム水溶液を亜硫酸ナトリウム水溶液とし、微粉造粒で投入する亜硫酸水素ナトリウム水溶液を亜硫酸ナトリウム水溶液としたこと以外は、製造例２３と同様にして、造粒ゲル（２５）を得た。 [Manufacturing Example 25]
In Production Example 23, 1.32 g of a 20 mass% ethylenediaminetetramethylenephosphonic acid 5 sodium aqueous solution added by polymerization is used, a sodium hydrogen sulfite aqueous solution added by gel grinding is used as a sodium sulfite aqueous solution, and sodium hydrogen sulfite is added by fine powder granulation. A granulated gel (25) was obtained in the same manner as in Production Example 23, except that the aqueous solution was an aqueous solution of sodium sulfite.
　［製造例２６］
　製造例２４において、重合で添加する２０質量％エチレンジアミンテトラメチレンホスホン酸５ナトリウム水溶液を１．３２ｇとし、ゲル粉砕で添加する亜硫酸水素ナトリウム水溶液を亜硫酸ナトリウム水溶液とし、粒子状含水ゲルと併せる造粒ゲルを製造例２５で得られた造粒ゲル（２５）とし、表面架橋後に添加する亜硫酸水素ナトリウム水溶液を亜硫酸ナトリウム水溶液としたこと以外は、製造例２４と同様にして、吸水性樹脂（２６）を得た。 [Manufacturing Example 26]
In Production Example 24, 1.32 g of a 20 mass% ethylenediaminetetramethylenephosphonic acid 5 sodium aqueous solution added by polymerization is used, and a sodium hydrogen sulfite aqueous solution added by gel grinding is used as a sodium sulfite aqueous solution, and the granulated gel is combined with a particulate hydrogel. The water-absorbent resin (26) was used in the same manner as in Production Example 24, except that the granulated gel (25) obtained in Production Example 25 was used and the sodium hydrogen sulfite aqueous solution added after surface cross-linking was a sodium sulfite aqueous solution. Obtained.
　［製造例２７］
　製造例８において、乾燥重合体（８）をロールミルで２回粉砕したこと以外は、製造例８と同様にして、吸水性樹脂（２７）を得た。 [Manufacturing Example 27]
A water-absorbent resin (27) was obtained in the same manner as in Production Example 8 except that the dry polymer (8) was pulverized twice with a roll mill in Production Example 8.
　［製造例２８］
　製造例２７において、粉砕後、目開き８５０μｍおよび１０６μｍの二種類のＪＩＳ標準篩を用いて、ロータップ式篩分級機で分級したこと以外は、製造例２７と同様にして、吸水性樹脂（２８）を得た。 [Manufacturing Example 28]
In Production Example 27, the water-absorbent resin (28) was classified in the same manner as in Production Example 27, except that after pulverization, the particles were classified by a low-tap sieve classifier using two types of JIS standard sieves having a mesh size of 850 μm and 106 μm. Got
　［実施例２５］
　製造例８で得られた、吸水性樹脂（８）１００質量部に対して、４０質量％の水分散性エマルジョンＡ（スチレン／アクリル酸ブチル／２－イソプロペニル－２－オキサゾリン／ジビニルベンゼン＝５８．１／２１．８／２０．０／０．１質量％、ＬｏｇＰ＝３．２９、平均粒径：８０ｎｍ）を１．２５質量部（固形分換算で０．５質量部）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（２５）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Example 25]
40% by mass of water-dispersible emulsion A (styrene / butyl acrylate / 2-isopropenyl-2-oxazolin / divinylbenzene = 58) with respect to 100 parts by mass of the water-absorbent resin (8) obtained in Production Example 8. .1 / 21.8 / 20.0 / 0.1% by mass, LogP = 3.29, average particle size: 80 nm) was added and mixed by 1.25 parts by mass (0.5 parts by mass in terms of solid content). Further, the mixture was heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (25). Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［実施例２６］
　実施例２５において、吸水性樹脂（８）を、製造例１０で得られた吸水性樹脂（１０）に変更した以外は実施例２５と同様にして、吸水性樹脂組成物（２６）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Example 26]
In Example 25, the water-absorbent resin composition (26) was obtained in the same manner as in Example 25 except that the water-absorbent resin (8) was changed to the water-absorbent resin (10) obtained in Production Example 10. .. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［実施例２７］
　実施例２５において、吸水性樹脂（８）を、製造例１２で得られた吸水性樹脂（１２）に変更した以外は実施例２５と同様にして、吸水性樹脂組成物（２７）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Example 27]
In Example 25, the water-absorbent resin composition (27) was obtained in the same manner as in Example 25 except that the water-absorbent resin (8) was changed to the water-absorbent resin (12) obtained in Production Example 12. .. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［実施例２８］
　実施例２５において、吸水性樹脂（８）を、製造例１４で得られた吸水性樹脂（１４）１００質量部に変更した以外は実施例２５と同様にして、吸水性樹脂組成物（２８）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Example 28]
In Example 25, the water-absorbent resin composition (28) was the same as in Example 25 except that the water-absorbent resin (8) was changed to 100 parts by mass of the water-absorbent resin (14) obtained in Production Example 14. Got Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［実施例２９］
　実施例２５において、吸水性樹脂（８）を、製造例１６で得られた吸水性樹脂（１６）に変更した以外は実施例２５と同様にして、吸水性樹脂組成物（２９）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Example 29]
In Example 25, the water-absorbent resin composition (29) was obtained in the same manner as in Example 25 except that the water-absorbent resin (8) was changed to the water-absorbent resin (16) obtained in Production Example 16. .. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［実施例３０］
　製造例１８で得られた、吸水性樹脂（１８）１００質量部に対して、２５質量％の水溶性ポリマーＢ（２－イソプロペニル－２－オキサゾリン／アクリル酸エチル／メタクリル酸メチル／メトキシポリエチレングリコールアクリレート（ｎ＝９）＝５０／２２／３／２５質量％、重量平均分子量＝約４０，０００、ＬｏｇＰ＝１．０７）の水溶液を２質量部（固形分換算で０．５質量部）添加混合し、さらに混合物を６０℃で３０分間加熱した。その後、混合物を解砕し、目開き８５０μｍのＪＩＳ標準篩を通過させ、吸水性樹脂組成物（３０）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Example 30]
25% by mass of water-soluble polymer B (2-isopropenyl-2-oxazoline / ethyl acrylate / methyl methacrylate / methoxypolyethylene glycol) with respect to 100 parts by mass of the water-absorbent resin (18) obtained in Production Example 18. Add 2 parts by mass (0.5 parts by mass in terms of solid content) of an aqueous solution of acrylate (n = 9) = 50/22/3/25% by mass, weight average molecular weight = about 40,000, LogP = 1.07). It was mixed and the mixture was further heated at 60 ° C. for 30 minutes. Then, the mixture was crushed and passed through a JIS standard sieve having an opening of 850 μm to obtain a water-absorbent resin composition (30). Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［実施例３１］
　実施例３０において、吸水性樹脂（１８）を、製造例２０で得られた吸水性樹脂（２０）に変更した以外は実施例３０と同様にして、吸水性樹脂組成物（３１）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Example 31]
In Example 30, the water-absorbent resin composition (31) was obtained in the same manner as in Example 30 except that the water-absorbent resin (18) was changed to the water-absorbent resin (20) obtained in Production Example 20. .. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［実施例３２］
　実施例３０において、吸水性樹脂（１８）を、製造例２２で得られた、吸水性樹脂（２２）に変更した以外は実施例３０と同様にして、吸水性樹脂組成物（３２）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Example 32]
In Example 30, the water-absorbent resin composition (32) was obtained in the same manner as in Example 30 except that the water-absorbent resin (18) was changed to the water-absorbent resin (22) obtained in Production Example 22. rice field. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［実施例３３］
　実施例３０において、吸水性樹脂（１８）を、製造例２４で得られた吸水性樹脂（２４）に変更した以外は実施例３０と同様にして、吸水性樹脂組成物（３３）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Example 33]
In Example 30, the water-absorbent resin composition (33) was obtained in the same manner as in Example 30 except that the water-absorbent resin (18) was changed to the water-absorbent resin (24) obtained in Production Example 24. .. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［実施例３４］
　実施例３０において、吸水性樹脂（１８）を、製造例２６で得られた吸水性樹脂（２６）に変更した以外は実施例３０と同様にして、吸水性樹脂組成物（３４）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Example 34]
In Example 30, the water-absorbent resin composition (34) was obtained in the same manner as in Example 30 except that the water-absorbent resin (18) was changed to the water-absorbent resin (26) obtained in Production Example 26. .. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［実施例３５］
　実施例３０において、吸水性樹脂（１８）を、製造例２７で得られた吸水性樹脂（２７）に変更した以外は実施例３０と同様にして、吸水性樹脂組成物（３５）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Example 35]
In Example 30, the water-absorbent resin composition (35) was obtained in the same manner as in Example 30 except that the water-absorbent resin (18) was changed to the water-absorbent resin (27) obtained in Production Example 27. .. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［実施例３６］
　実施例１４において、吸水性樹脂（１）を、製造例２７で得られた吸水性樹脂（２７）に変更した以外は実施例１４と同様にして、吸水性樹脂組成物（３６）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Example 36]
In Example 14, the water-absorbent resin composition (36) was obtained in the same manner as in Example 14 except that the water-absorbent resin (1) was changed to the water-absorbent resin (27) obtained in Production Example 27. .. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［比較例８］
　製造例８で得られた吸水性樹脂（８）を、そのまま比較用吸水性樹脂組成物（８）として用いた。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Comparative Example 8]
The water-absorbent resin (8) obtained in Production Example 8 was used as it was as the water-absorbent resin composition (8) for comparison. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［比較例９］
　製造例１０で得られた吸水性樹脂（１０）を、そのまま比較用吸水性樹脂組成物（９）として用いた。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Comparative Example 9]
The water-absorbent resin (10) obtained in Production Example 10 was used as it was as the water-absorbent resin composition (9) for comparison. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［比較例１０］
　製造例１２で得られた吸水性樹脂（１２）を、そのまま比較用吸水性樹脂組成物（１０）として用いた。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Comparative Example 10]
The water-absorbent resin (12) obtained in Production Example 12 was used as it was as the water-absorbent resin composition (10) for comparison. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［比較例１１］
　製造例１４で得られた吸水性樹脂（１４）を、そのまま比較用吸水性樹脂組成物（１１）として用いた。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Comparative Example 11]
The water-absorbent resin (14) obtained in Production Example 14 was used as it was as the comparative water-absorbent resin composition (11). Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［比較例１２］
　製造例１６で得られた吸水性樹脂（１６）を、そのまま比較用吸水性樹脂組成物（１２）として用いた。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Comparative Example 12]
The water-absorbent resin (16) obtained in Production Example 16 was used as it was as the water-absorbent resin composition (12) for comparison. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［比較例１３］
　製造例１８で得られた吸水性樹脂（１８）を、そのまま比較用吸水性樹脂組成物（１３）として用いた。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Comparative Example 13]
The water-absorbent resin (18) obtained in Production Example 18 was used as it was as the water-absorbent resin composition (13) for comparison. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［比較例１４］
　製造例２０で得られた吸水性樹脂（２０）を、そのまま比較用吸水性樹脂組成物（１４）として用いた。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Comparative Example 14]
The water-absorbent resin (20) obtained in Production Example 20 was used as it was as the water-absorbent resin composition (14) for comparison. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［比較例１５］
　製造例２２で得られた吸水性樹脂（２２）を、そのまま比較用吸水性樹脂組成物（１５）として用いた。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Comparative Example 15]
The water-absorbent resin (22) obtained in Production Example 22 was used as it was as the water-absorbent resin composition (15) for comparison. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［比較例１６］
　製造例２４で得られた吸水性樹脂（２４）を、そのまま比較用吸水性樹脂組成物（１６）として用いた。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Comparative Example 16]
The water-absorbent resin (24) obtained in Production Example 24 was used as it was as the comparative water-absorbent resin composition (16). Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［比較例１７］
　製造例２６で得られた吸水性樹脂（２６）を、そのまま比較用吸水性樹脂組成物（１７）として用いた。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Comparative Example 17]
The water-absorbent resin (26) obtained in Production Example 26 was used as it was as the water-absorbent resin composition (17) for comparison. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［比較例１８］
　実施例３０において、吸水性樹脂（１８）を、製造例２８で得られた吸水性樹脂（２８）に変更した以外は実施例３０と同様にして、比較用吸水性樹脂組成物（１８）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Comparative Example 18]
In Example 30, the comparative water-absorbent resin composition (18) was prepared in the same manner as in Example 30 except that the water-absorbent resin (18) was changed to the water-absorbent resin (28) obtained in Production Example 28. Obtained. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
　［比較例１９］
　実施例１４において、吸水性樹脂（１）を、製造例２８で得られた吸水性樹脂（２８）に変更した以外は実施例１４と同様にして、比較用吸水性樹脂組成物（１９）を得た。累積粒径およびスパン値、消臭試験結果、ＣＲＣ、ＡＡＰ測定結果を表２に示した。 [Comparative Example 19]
In Example 14, the comparative water-absorbent resin composition (19) was prepared in the same manner as in Example 14 except that the water-absorbent resin (1) was changed to the water-absorbent resin (28) obtained in Production Example 28. Obtained. Table 2 shows the cumulative particle size and span value, deodorant test results, CRC, and AAP measurement results.
Figure JPOXMLDOC01-appb-T000012
Figure JPOXMLDOC01-appb-T000012
Figure JPOXMLDOC01-appb-T000013
Figure JPOXMLDOC01-appb-T000013
Figure JPOXMLDOC01-appb-T000014
Figure JPOXMLDOC01-appb-T000014
Figure JPOXMLDOC01-appb-T000015
Figure JPOXMLDOC01-appb-T000015
　＜考察＞
　表１に示される結果より、以下の考察を行う。なお、消臭試験の結果が３．００以上であると本願の所期の効果が得られていないことを意味し、消臭試験の結果が３．００未満であれば本願の所期の効果が得られていることを意味する。 <Discussion>
Based on the results shown in Table 1, the following considerations will be made. If the result of the deodorant test is 3.00 or more, it means that the intended effect of the present application is not obtained, and if the result of the deodorant test is less than 3.00, the expected effect of the present application is not obtained. Means that is obtained.
　比較例１、８～１７と、実施例を比較すると、疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分を含む吸水性樹脂組成物は、消臭試験において、尿臭の強度レベルが大幅に減少しており、高い尿臭抑制効果を有することがわかる。特に、実施例１と実施例２３を比較すると、疎水性多孔質ポリマー吸着剤と含窒素複素環を有する樹脂を併用することにより、尿臭抑制効果がさらに向上することが分かる。 Comparing Comparative Examples 1 and 8 to 17 with Examples, a water-absorbent resin composition containing at least one component of a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle was found in urine in a deodorizing test. It can be seen that the intensity level of the odor is significantly reduced and that it has a high urine odor suppressing effect. In particular, when Example 1 and Example 23 are compared, it can be seen that the effect of suppressing urine odor is further improved by using the hydrophobic porous polymer adsorbent and the resin having a nitrogen-containing heterocycle in combination.
　一方、比較例２、１８、１９と、実施例を比較すると、疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分を含んでいても、スパン値が本発明の範囲外であると、得られる尿臭抑制効果が大幅に低減してしまうことがわかる。 On the other hand, when Comparative Examples 2, 18 and 19 are compared with Examples, the span value is within the range of the present invention even if at least one component of the hydrophobic porous polymer adsorbent and the resin having a nitrogen-containing heterocycle is contained. It can be seen that when it is outside, the obtained urine odor suppressing effect is significantly reduced.
　また、比較例３および４より、疎水性多孔質ポリマーの代わりに、細孔構造を有しない微粒子や、無機系多孔質吸着剤であるゼオライトを用いた場合、吸着剤の総比表面積は実施例と同等程度であるにも関わらず十分な消臭効果が得られない。このことから、吸着剤としては細孔構造を有する疎水性多孔質ポリマーであることが必要であることが分かる。 Further, from Comparative Examples 3 and 4, when fine particles having no pore structure or zeolite as an inorganic porous adsorbent were used instead of the hydrophobic porous polymer, the total specific surface area of the adsorbent was Example. Although it is about the same as the above, a sufficient deodorizing effect cannot be obtained. From this, it can be seen that the adsorbent needs to be a hydrophobic porous polymer having a pore structure.
　また、比較例５より、疎水性多孔質ポリマー吸着剤の代わりに、アンモニア、トリメチルアミン、ジメチルジスルフィド等の臭気原因物質と結合し、消臭効果を示すと言われているペルオキソ一硫酸カリウムを用いても、十分な消臭効果が得られない。 Further, from Comparative Example 5, instead of the hydrophobic porous polymer adsorbent, potassium peroxomonosulfate, which is said to have a deodorizing effect by binding to an odor-causing substance such as ammonia, trimethylamine, and dimethyl disulfide, is used. However, a sufficient deodorizing effect cannot be obtained.
　また、比較例６より、窒素を含んでいても複素環化合物ではない樹脂を使用した場合、尿臭抑制効果が得られないことが分かる。 Further, from Comparative Example 6, it can be seen that the urine odor suppressing effect cannot be obtained when a resin containing nitrogen but not a heterocyclic compound is used.
　また、比較例７より、含窒素複素環を有する樹脂を吸水性樹脂に添加後、表面処理時に想定されるような温度で加熱すると、尿臭抑制効果が得られないことが分かる。 Further, from Comparative Example 7, it can be seen that the urine odor suppressing effect cannot be obtained when the resin having a nitrogen-containing heterocycle is added to the water-absorbent resin and then heated at the temperature expected at the time of surface treatment.
　よって、本発明の解題を解決するには、「吸水性樹脂と、疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分を含み、スパン値が特定値以下である」との構成が重要であることが分かる。 Therefore, in order to solve the problem of the present invention, "a water-absorbent resin, a hydrophobic porous polymer adsorbent, and a resin having a nitrogen-containing heterocycle are contained at least one component, and the span value is equal to or less than a specific value." It turns out that the composition of and is important.
　本出願は、２０２０年１０月２１日に出願された日本特許出願番号２０２０－１７６５７２号に基づいており、その開示内容は、参照され、全体として、組み入れられている。
  This application is based on Japanese Patent Application No. 2020-176572 filed on October 21, 2020, the disclosure of which is referenced and incorporated as a whole.

Claims (15)

  1. 　吸水性樹脂と、疎水性多孔質ポリマー吸着剤および含窒素複素環を有する樹脂の少なくとも一方の成分とを含み、
    　下記式１で表されるスパン値が、１．１０以下である、吸水性樹脂組成物。
    Figure JPOXMLDOC01-appb-M000001
     　Ｄ（９０％）は、粒子径の累積粒径分布において、最小径からの累積が９０％となる粒
    子径（単位：μｍ）
    　Ｄ（１０％）は、粒子径の累積粒径分布において、最小径からの累積が１０％となる粒子径（単位：μｍ）
    　Ｄ（５０％）は、粒子径の累積粒径分布において、最小径からの累積が５０％となる粒子径（単位：μｍ）
    　ここで、Ｄ（９０％）、Ｄ（１０％）、Ｄ（５０％）は、質量基準で累積した値である。     It contains a water-absorbent resin and at least one component of a hydrophobic porous polymer adsorbent and a resin having a nitrogen-containing heterocycle.
    A water-absorbent resin composition having a span value represented by the following formula 1 of 1.10 or less.
    Figure JPOXMLDOC01-appb-M000001
     D (90%) is a particle size (unit: μm) in which the cumulative particle size distribution from the minimum diameter is 90%.
    D (10%) is a particle size (unit: μm) in which the cumulative particle size distribution from the minimum diameter is 10%.
    D (50%) is a particle size (unit: μm) in which the cumulative particle size distribution from the minimum diameter is 50%.
    Here, D (90%), D (10%), and D (50%) are cumulative values on a mass basis.
  2. 　前記含窒素複素環が、５員環または６員環の含窒素複素環である、請求項１に記載の吸水性樹脂組成物。 The water-absorbent resin composition according to claim 1, wherein the nitrogen-containing heterocycle is a 5-membered or 6-membered nitrogen-containing heterocycle.
  3. 　前記含窒素複素環を有する樹脂が、水不溶性または下記式１で規定されるＬｏｇＰが１．５以上の水に分散可能なポリマーである、請求項１または２に記載の吸水性樹脂組成物。
    Figure JPOXMLDOC01-appb-M000002
     （式１中、ＶＭＬｏｇＰ（ｉ）は、ポリマー繰り返し単位（ｉ）の両端をメチル化した仮
    想モノマー単位（Ｖｉｒｔｕａｌ　Ｍｏｎｏｍｅｒ（ＶＭ））の２５℃での“ｎ－オクタノール－水分配係数”の計算値であり、ＭＲ（ｉ）は、繰り返し単位（ｉ）の“モル比率（Ｍｏｌ　Ｒａｔｉｏ（ＭＲ）”）である。）     The water-absorbent resin composition according to claim 1 or 2, wherein the resin having a nitrogen-containing heterocycle is a polymer that is water-insoluble or dispersible in water having a LogP of 1.5 or more as defined by the following formula 1.
    Figure JPOXMLDOC01-appb-M000002
     (In Formula 1, VMLogP (i) is a calculated value of "n-octanol-water partition coefficient" at 25 ° C. of a virtual monomer unit (Virtual Monomer (VM)) in which both ends of the polymer repeating unit (i) are methylated. MR (i) is the “mol ratio (MolRatio (MR)”) of the repeating unit (i).)
  4. 　前記含窒素複素環を有する樹脂の平均粒径が、５０～２５０，０００ｎｍである、請求項３に記載の吸水性樹脂組成物。 The water-absorbent resin composition according to claim 3, wherein the resin having a nitrogen-containing heterocycle has an average particle size of 50 to 250,000 nm.
  5. 　前記疎水性多孔質ポリマー吸着剤が、疎水性単量体由来の構成単位を含み、平均細孔直径が５０～１０００Åの多孔質重合体である、請求項１～４のいずれか１項に記載の吸水性樹脂組成物。 The one according to any one of claims 1 to 4, wherein the hydrophobic porous polymer adsorbent is a porous polymer containing a structural unit derived from a hydrophobic monomer and having an average pore diameter of 50 to 1000 Å. Water-absorbent resin composition.
  6. 　前記疎水性多孔質ポリマー吸着剤の比表面積が、２０～２０００ｍ２／ｇである、請求項１～５のいずれかに１項に記載の吸水性樹脂組成物。 The water-absorbent resin composition according to any one of claims 1 to 5, wherein the hydrophobic porous polymer adsorbent has a specific surface area of 20 to 2000 m 2 / g.
  7. 　前記吸水性樹脂１００質量部に対する前記含窒素複素環を有する樹脂の含有量が、０．０１～３０質量部である、請求項１～６のいずれか１項に記載の吸水性樹脂組成物。 The water-absorbent resin composition according to any one of claims 1 to 6, wherein the content of the resin having the nitrogen-containing heterocycle is 0.01 to 30 parts by mass with respect to 100 parts by mass of the water-absorbent resin.
  8. 　前記吸水性樹脂１００質量部に対する前記疎水性多孔質ポリマー吸着剤の含有量が、０．０５～１０質量部である、請求項１～６のいずれか１項に記載の吸水性樹脂組成物。 The water-absorbent resin composition according to any one of claims 1 to 6, wherein the content of the hydrophobic porous polymer adsorbent with respect to 100 parts by mass of the water-absorbent resin is 0.05 to 10 parts by mass.
  9. 　接触角が、３５°以上である、請求項１～８のいずれか１項に記載の吸水性樹脂組成物。 The water-absorbent resin composition according to any one of claims 1 to 8, wherein the contact angle is 35 ° or more.
  10. 　前記吸水性樹脂と、前記成分とを結着する、バインダを含む、請求項１～９のいずれか１項に記載の吸水性樹脂組成物。 The water-absorbent resin composition according to any one of claims 1 to 9, which comprises a binder that binds the water-absorbent resin and the component.
  11. 　前記バインダが、ポリオールである、請求項１０に記載の吸水性樹脂組成物。 The water-absorbent resin composition according to claim 10, wherein the binder is a polyol.
  12. 　キレート剤を含む、請求項１～１１のいずれか１項に記載の吸水性樹脂組成物。 The water-absorbent resin composition according to any one of claims 1 to 11, which comprises a chelating agent.
  13. 　前記吸水性樹脂の加圧下吸水倍率（ＡＡＰ４．８３ｋＰａ）が、５ｇ／ｇ以上である、請求項１～１２のいずれか１項に記載の吸水性樹脂組成物。 The water-absorbent resin composition according to any one of claims 1 to 12, wherein the water-absorbent resin has a water absorption ratio under pressure (AAP4.83 kPa) of 5 g / g or more.
  14. 　請求項１～１３のいずれか１項に記載の吸水性樹脂組成物を含む、吸収体。 An absorber containing the water-absorbent resin composition according to any one of claims 1 to 13.
  15. 　請求項１４に記載の吸収体と、液透過性を有する表面シート、液不透過性を有する背面シートとを備える、吸収性物品。 An absorbent article comprising the absorber according to claim 14, a front sheet having liquid permeability, and a back sheet having liquid permeability.
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Publication number Priority date Publication date Assignee Title
CN116768435A (en) * 2023-05-29 2023-09-19 浙江湖州赛诚生态科技有限公司 Environment-friendly silt stabilizing curing agent and preparation method thereof
CN116768435B (en) * 2023-05-29 2024-05-07 浙江赛诚生态科技有限公司 Environment-friendly silt stabilizing curing agent and preparation method thereof

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