WO2017078369A1 - Method for preparing superabsorbent polymer - Google Patents

Method for preparing superabsorbent polymer Download PDF

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Publication number
WO2017078369A1
WO2017078369A1 PCT/KR2016/012461 KR2016012461W WO2017078369A1 WO 2017078369 A1 WO2017078369 A1 WO 2017078369A1 KR 2016012461 W KR2016012461 W KR 2016012461W WO 2017078369 A1 WO2017078369 A1 WO 2017078369A1
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Prior art keywords
polymer
fine powder
weight
water
super absorbent
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PCT/KR2016/012461
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French (fr)
Korean (ko)
Inventor
김동현
한장선
남대우
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주식회사 엘지화학
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Priority claimed from KR1020160142887A external-priority patent/KR101960043B1/en
Application filed by 주식회사 엘지화학 filed Critical 주식회사 엘지화학
Priority to CN201680006819.6A priority Critical patent/CN107207745B/en
Priority to EP16862385.8A priority patent/EP3225649B1/en
Priority to US15/540,705 priority patent/US10086362B2/en
Publication of WO2017078369A1 publication Critical patent/WO2017078369A1/en

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00—Processes of polymerisation
    • C08F2/04—Polymerisation in solution
    • C08F2/10—Aqueous solvent
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00—Processes of polymerisation
    • C08F2/44—Polymerisation in the presence of compounding ingredients, e.g. plasticisers, dyestuffs, fillers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J3/00—Processes of treating or compounding macromolecular substances
    • C08J3/02—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques
    • C08J3/03—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques in aqueous media
    • C08J3/075—Macromolecular gels
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J3/00—Processes of treating or compounding macromolecular substances
    • C08J3/24—Crosslinking, e.g. vulcanising, of macromolecules

Definitions

  • the present invention relates to a method for producing a super absorbent polymer. More specifically, the present invention relates to a method for producing a super absorbent polymer having a high fine powder cohesive strength. [Technique to become background of invention]
  • Super Absorbent Polymer is a synthetic polymer material capable of absorbing water of 500 to 1,000 times its own weight.
  • SAP Super Absorbent Polymer
  • Such super absorbent polymers have been put into practical use as physiological tools, and are currently used in gardening, soil repair agents, civil engineering, building index materials, seedling sheets, food fresheners in addition to hygiene products such as paper diapers for children, and It is widely used as a material for steaming.
  • a method for producing such a super absorbent polymer a method by reverse phase suspension polymerization or a method by aqueous solution polymerization is known.
  • Reverse phase suspension polymerization is disclosed in, for example, Japanese Patent Laid-Open No. 56-161408, Japanese Patent Laid-Open No. 158209, Japanese Patent Laid-Open No. 57-198714, and the like.
  • a thermal polymerization method of breaking and staggering a polymerization gel in a kneader having several shafts and a photopolymerization method of simultaneously performing polymerization and drying by irradiating ultraviolet rays or the like on a belt with a high concentration of aqueous solution Etc. are known.
  • the hydrous gel polymer obtained through the polymerization reaction as described above is generally pulverized through a drying process and then marketed as a powder product.
  • f ines having a particle size of less than about 150 ⁇ may be generated during the cutting, grinding and powdering of the dried polymer. It is considered undesirable in hygiene articles including infant diapers and adult incontinence devices because the superabsorbent polymer particles prepared including the fine powder may exhibit physical properties that have been transferred or degraded prior to use when applied to the product. Therefore, the reassembling process of excluding the fine powder in the final resin product or aggregating the fine powder to a normal particle size is often performed, and the coagulation strength of the reassembled polymer is often broken down into fine powder again.
  • the present invention relates to a method for producing a superabsorbent polymer having improved permeability without increasing water retention capacity or pressure absorption capacity by increasing the foaming strength of the fine powder reassembly.
  • the present invention comprises the steps of thermal polymerization ' or photopolymerization to the monomer composition comprising a water-soluble ethylenically unsaturated monomer and a polymerization initiator to form a hydrogel polymer; Drying the hydrogel polymer; Pulverizing the dried polymer; Classifying the ground polymer into fine powder having a particle size of less than 150 m and a polymer having a particle size of 150 to 850 IM depending on the particle size; 50 to 200 parts by weight of mixed water of 5 to 30 ° C.
  • a step of thermally polymerizing or photopolymerizing a monomer composition comprising a water-soluble ethylenically unsaturated monomer and a polymerization initiator to form a hydrogel polymer; Drying the hydrogel polymer; Pulverizing the dried polymer; Classifying the pulverized polymer into fine powder having a particle size of less than 150 IM and a polymer having a particle size of 150 to 850 depending on the particle size; Reassembling by mixing 50 to 200 parts by weight of water at a temperature of 5 to 30 ° C with respect to 100 parts by weight of fine powder having a particle diameter of 150 im or less; And a surface crosslinking of the polymer having a particle diameter of 150 to 850 m and the fine powder reassembly, may be provided.
  • the monomer composition which is a raw material of the super absorbent polymer includes a water-soluble ethylenically unsaturated mono
  • the water-soluble ethylenically unsaturated monomer may be used without any limitation any monomers commonly used in the production of superabsorbent polymers. Any one or more monomers selected from the group consisting of anionic monomers and salts thereof, nonionic hydrophilic-containing monomers and amino group-containing unsaturated monomers and quaternized compounds thereof can be used. _
  • alkali metal salts such as acrylic acid or salts thereof, for example acrylic acid or sodium salts thereof, may be used.
  • acrylic acid or salts thereof for example acrylic acid or sodium salts thereof
  • the use of such monomers enables the production of superabsorbent polymers having better physical properties.
  • acrylic acid may be neutralized with a basic compound such as caustic soda (NaOH).
  • the concentration of the water-soluble ethylenically unsaturated monomer may be about 20 to about 60% by weight, preferably about 40 to about 50% by weight, based on the monomer composition including the raw material and the solvent of the superabsorbent polymer.
  • the concentration may be appropriate in consideration of time and reaction conditions. However, when the concentration of the monomer is too low, the yield of the superabsorbent polymer may be low and there may be a problem in economics. On the contrary, when the concentration is too high, some of the monomer may be precipitated or the grinding efficiency of the polymerized hydrogel polymer may be low. Etc. may cause problems in the process and may decrease the physical properties of the super absorbent polymer.
  • the polymerization initiator is not particularly limited as long as it is generally used for the production of superabsorbent polymers, and may be a thermal polymerization initiator or a photopolymerization initiator according to UV irradiation depending on the polymerization method.
  • the photopolymerization method since a certain amount of heat is generated by irradiation of ultraviolet radiation or the like, and a certain amount of heat is generated in accordance with the progress of the polymerization reaction, which is an exothermic reaction, it may further include a thermal polymerization initiator.
  • the photopolymerization initiator may be used without any limitation as long as it is a compound capable of forming radicals by light such as ultraviolet rays.
  • acyl phosphine for example, benzoin ether, dialkyl acetophenone, hydroxyl alkylketone, phenylglyoxylate, benzyldimethyl ketal (Benzyl Dimethyl Ketal), acyl phosphine and One or more selected from the group consisting of alpha-aminoketone may be used.
  • acylphosphine commercially available lucirin TP0, that is, 2,4,6-trimethyl-benzoyl-trimethyl phosphine oxide (2,4,6-trimethyl-benzoyl-tr imethyl phosphine oxide) 3 ⁇ 4- can be used.
  • lucirin TP0 that is, 2,4,6-trimethyl-benzoyl-trimethyl phosphine oxide (2,4,6-trimethyl-benzoyl-tr imethyl phosphine oxide) 3 ⁇ 4- can be used.
  • lucirin TP0 2,4,6-trimethyl-benzoy
  • the photopolymerization initiator may be included in a concentration of about 0.01 to about 1.0 wt% based on the monomer composition. When the concentration of the photopolymerization initiator is too low, the polymerization rate may be slow. When the concentration of the photopolymerization initiator is too high, the molecular weight of the superabsorbent polymer may be low and the physical properties may be uneven.
  • the thermal polymerization initiator may be used at least one selected from the group consisting of persulfate initiator, azo initiator, hydrogen peroxide and ascorbic acid.
  • persulfate-based initiators include sodium persulfate (Na 2 S 2 0 8 ), potassium persulfate (K 2 S 2 0 8 ), ammonium persulfate (NH 4 ) 2 S2 (3 ⁇ 4)
  • azo initiators include 2, 2-azobis- (2-amidinopropane) dihydrochloride (2, 2-azob is (2-am idi nopr opane) dihydrochlor ide) : 2, 2-azobis- (N, N-dimethylene) isobutyramidine dihydrochloride (2, 2-azobis- (N, N—dimethyl ene) i sobuty rami dine dihydrochloride), 2— ( Carbamoyl azo) isobutyronitrile (2-
  • the thermal polymerization initiator may be included in a concentration of about 0.001 to about 0.5% by weight based on the monomer composition.
  • the concentration of this thermal polymerization initiator When too low, additional thermal polymerization hardly occurs, so that the effect of the addition of the thermal polymerization initiator may be insignificant.
  • the concentration of the thermal polymerization initiator is too high, the molecular weight of the superabsorbent polymer may be small and the physical properties may be uneven.
  • the monomer composition may further include an internal crosslinking agent as a raw material of the super absorbent polymer.
  • the internal crosslinking agent include a crosslinking agent having at least one ethylenically unsaturated group while having at least one functional group capable of reacting with the water-soluble substituent of the water-soluble ethylenically unsaturated monomer;
  • a crosslinking agent having two or more water-soluble substituents and / or functional groups capable of reacting with the water-soluble substituents formed by hydrolysis of the monomers may be used.
  • the internal crosslinking agent examples include bisacrylamide having 8 to 12 carbon atoms, bismethacrylamide, poly (meth) acrylate having 2 to 10 carbon atoms or poly (meth) allyl ether having 2 to 10 carbon atoms. More specifically, N, ⁇ '- methylenebis (meth) acrylate, ethyleneoxy (meth) acrylate, polyethyleneoxy (meth) acrylate, propyleneoxy (meth) acrylate, glycerin diacrylate Glycerol triacrylate, trimethy triacrylate, triallylamine, triaryl cyanurate, triallyl isocyanate, polyethylene glycol, diethylene glycol and propylene glycol may be used.
  • Such an internal crosslinking agent may be included in a concentration of about 0.01 wt% to about 0.5 wt% based on the monomer composition to crosslink the polymerized polymer.
  • the monomer composition of the superabsorbent polymer production method of the embodiment may further include additives such as a thickener, a plasticizer, a storage stabilizer, an antioxidant, and the like, as necessary.
  • Raw materials such as the above-mentioned water-soluble ethylenically unsaturated monomers, photopolymerization initiators, thermal polymerization initiators, internal crosslinking agents and additives may be prepared in the form of a monomer composition solution dissolved in a solvent.
  • the solvent that can be used at this time can be used without limitation in the composition as long as it can dissolve the above-mentioned components, for example, water, ethane, Ethylene glycol, diethylene glycol, triethylene glycol, 1,4-butanediol, propylene glycol, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl ethyl ketone, acetone, methyl amyl ketone, cyclo 1 type selected from nucleanone, cyclopentanone, diethylene glycol monomethyl ether, diethylene glycol ethyl ether, toluene, xylene, butyrolactone, carbyl, methyl salosolve acetate, and N, N-dimethylacetamide
  • the above can be used in combination.
  • the solvent may be included in the remaining amount except for the above-described components with respect to the total content of the monomer
  • the method of forming a hydrogel polymer by thermally polymerizing or photopolymerizing such a monomer composition is not particularly limited as long as it is a commonly used polymerization method.
  • the polymerization method is largely divided into thermal polymerization and photopolymerization according to the polymerization energy source, and when the thermal polymerization is usually carried out, it can be carried out in a semi-unggi with a stirring shaft such as kneader, when the polymerization proceeds, Although it can proceed in a semi-unggi equipped with a conveyor belt possible, the above-described polymerization method is an example, the present invention is not limited to the above-described polymerization method.
  • the hydrogel polymer obtained by thermal polymerization by supplying hot air or by heating the reaction vessel may be a semi-ungker, such as a kneader having a stirring shaft, according to the shape of the stirring shaft provided in the reactor.
  • the hydrogel polymer discharged to the outlet may be in the form of several centimeters to several millimeters.
  • the size of the water-containing gel polymer obtained may vary depending on the concentration and the injection speed of the monomer composition to be injected, it can be obtained a water-containing gel polymer having a weight average particle diameter of 2 to 50 kPa.
  • the form of the hydrogel polymer generally obtained may be a hydrogel gel polymer on a sheet having a width of the belt.
  • the thickness of the polymer sheet depends on the concentration and the injection speed of the monomer composition to be injected, but it is usually preferable to supply the monomer composition so that a polymer on the sheet having a thickness of about 0.5 to about 5 cm is obtained.
  • the water content of the hydrogel polymer obtained by the above method may be about 30 to about 70 wt%, preferably about 40 to about 60 wt%.
  • water content as used throughout the present specification means the content of the water to the total weight of the water-containing gel polymer subtracted from the weight of the water-containing gel polymer minus the weight of the dry polymer. Specifically, it is defined as a value calculated by measuring the weight loss due to moisture evaporation in the polymer in the process of raising the temperature of the polymer through infrared heating and drying. At this time, the drying conditions are raised to a temperature of about 180 ° C at room temperature and then maintained at 18 CTC, the total drying time is set to 20 minutes, including 5 minutes of temperature rise step, the moisture content is measured.
  • the pulverizer used is not limited in configuration, but specifically, a vertical pulverizer, a turbo cutter, a turbo grinder, a rotary cutter mill, a cutting machine Any one selected from the group of crushing machines consisting of cutter mills, disc mills, shred crushers, crushers, choppers and disc cutters Although it is possible, it is not limited to the above-mentioned example.
  • the grinding step may be pulverized so that the particle size of the hydrogel polymer is about 2 to about 10mm. Grinding to a particle diameter of less than 2 ⁇ s is not technically easy due to the high water content of the hydrogel polymer, and may also cause agglomeration between the milled particles. On the other hand, when the particle size is pulverized in excess of 10 ⁇ , the effect of increasing the efficiency of the subsequent drying step is insignificant. Drying is performed on the hydrous gel polymer immediately after the polymerization as described above or not subjected to the grinding step. At this time, the drying temperature of the drying step may be about 150 to about 250 ° C.
  • the drying temperature is less than 150 ° C, the drying time may be too long and the physical properties of the final superabsorbent polymer may be lowered. If the drying temperature is higher than 250 ° C, only the polymer surface is dried excessively. Fine powder may occur in the grinding process, and there is a fear that the physical properties of the superabsorbent polymer to be finally formed decrease.
  • the drying may be carried out at a temperature of about 150 to about 20 CTC, more preferably at a silver degree of about 160 to about 180 ° C.
  • drying time in consideration of the process efficiency, etc., it may proceed for about 20 to about 90 minutes, but is not limited thereto.
  • the drying method of the drying step is also commonly used as a drying step of the hydrogel polymer, it can be selected and used without limitation of the configuration. Specifically, the drying step may be performed by a method such as hot air supply, infrared irradiation, microwave irradiation, or ultraviolet irradiation.
  • the water content of the polymer after the drying step may be about 0.1 to about 10% by weight.
  • the dried polymer obtained through such a drying step is pulverized, which is distinguished from the coarse pulverizing step which is pulverized to 2 to about 10 mm 3, and the polymer powder obtained after the pulverizing step has a particle diameter of about 850 im or less.
  • the grinder used to grind to such a particle size may specifically be a pin mill, hammer mill, screw mill, roll mill, disc mill or A jog mill or the like may be used, but the present invention is not limited to the above-described example.
  • the polymer obtained after grinding is classified into fine powder having a particle size of less than 150 im and a polymer having a particle size of about 150 to about 850 depending on the particle size.
  • Fine particles having a particle size below a certain particle size, ie less than about 150 im, are referred to as superabsorbent polymer fine powder, polymer fine powder, SAP fine powder or fine powder (fines, fine powder).
  • the fines can be generated during the polymerization process, the drying process or the grinding of the dried polymer, When included, it is difficult to handle and exhibits a gel blocking phenomenon, thereby deteriorating physical properties. Therefore, it is preferable to exclude them from the final resin product or reuse them to become normal particles.
  • the water of 5 to 30 ° C may be mixed about 50 to 200 parts by weight with respect to 100 parts by weight of fine powder, the reassembly step is carried out in a wet state to increase the cohesive strength of the reassembly.
  • the higher the water content the higher the cohesive strength of the fine powder, but during the reassembly process, too large reassembly lumps or partly water-containing reassembly lumps (jelly balls) are formed and subsequent crushing processes are operated. Problems can arise.
  • the water content is low, the reassembly process is easy, but the foaming strength is low, and after reassembly, the powder is often crushed again.
  • the reaction may proceed by adding low temperature water of about 5 to 30 ° C to form a wet state in which the fine powder has the above-mentioned water content.
  • low temperature water of about 5 to 30 ° C
  • the rate of fungization after the drying and grinding process is reduced compared to the case of using high temperature water of about 60 ° C or more.
  • the water of 5 to 30 ° C was mixed with the fine powder by using a mist (mis st), spray nozzle (spray) device and the like can be wet.
  • mist mist
  • spray nozzle spray nozzle
  • the fine powder may be reassembled in a wet state having a water content of about 40 to 60 wt%.
  • the fine powder and water are mixed at an appropriate ratio, the fine powder may be wetted at a water content of about 40 to 60 wt%, and reassembled in this state, thereby preparing a fine powder reassembly having a higher coarse strength.
  • surface-crosslinking is carried out by mixing the above-mentioned polymer with a particle size of 150 to 850; ⁇ and a fine powder reassembly.
  • the polymer having a particle size of 150 to 850 urn is derived from the step of classifying the pulverized polymer according to the particle size, the range of the normal particle size range
  • the powder reassembly which corresponds to a polymer, refers to a reassembly which has been reassembled by the above-described method of fine powder having a particle diameter of less than 150 ⁇ derived in the classification step.
  • the fine powder reassembly may be used in a state derived from the fine powder reassembling process, or may be used in a state in which the fine powder reassembly is dried, pulverized and classified.
  • the drying, pulverizing and classification process of the fine powder reassembly can be applied without any limitation in the process of drying, pulverizing and classifying the hydrous gel polymer described above. .
  • the polymer having a particle size of 150 to 850 and the fine powder reassembly may be mixed at a weight ratio of about 6: 4 to 8: 2.
  • the mixing ratio there is no particular restriction on the mixing ratio, but as the ratio of the reassembly of the powder increases, the physical properties are reduced compared to the case of using only a polymer having a normal particle size range. It is preferable not to exceed the above.
  • the surface crosslinking step is to increase the crosslinking density near the surface of the superabsorbent polymer particles in relation to the crosslinking density inside the particles.
  • the surface crosslinking agent is applied to the surface of the super absorbent polymer particles.
  • this reaction occurs on the surface of the superabsorbent resin particles, which improves the crosslinkability on the surface of the particles without substantially affecting the interior of the particles.
  • the surface crosslinked superabsorbent resin particles thus have a higher degree of crosslinking in the vicinity of the surface than in the interior.
  • the surface crosslinking agent is not limited as long as it is a compound capable of reacting with the functional group of the polymer.
  • the surface crosslinking agent may be a polyhydric alcohol compound; Epoxy compounds; Polyamine compounds; Haloepoxy compound; Condensation products of haloepoxy compounds; Oxazoline compounds; Mono-, di- or polyoxazolidinone compounds; Cyclic urea compounds; Polyvalent metal salts; And it may include one or more selected from the group consisting of alkylene carbonate compounds.
  • examples of the polyhydric alcohol compound include mono-, di-, tri-, tetra- or polyethylene glycol, monopropylene glycol, 1,3-propanedi, dipropylene glycol, 2,3,4-trimethyl-1, 3 -Pentanedi, polypropylene glycol, glycerol, polyglycerol, 2-butene-1, 4-diol, 1,4-butanediol, 1, 3-butanedi, 1, 5-pentanedi, 1, 6-nucleic acid Di, and 1, 2-cyclohexane dimethane can be used 1 or more types chosen from the group which consists of.
  • Ethylene glycol diglycidyl ether and glycidol may be used as the epoxy compound, and polyamine compounds may be ethylene diamine, diethylene triamine, triethylene tetraamine, tetraethylenepentamine, or pentaethylene nucleoamine. , At least one selected from the group consisting of polyethyleneimine and polyamide polyamine can be used.
  • epichlorohydrin, epibromohydrin, and (alpha)-methyl epichlorohydrin can be used as a halo epoxy compound.
  • 2-oxazolidinone etc. can be used as a mono-, di-, or a polyoxazolidinone compound.
  • alkylene carbonate compound ethylene carbonate or the like may be used.
  • At least one alkylene carbonate compound in the surface crosslinking agent in order to minimize the formation of coarse particles after the surface crosslinking and increase the surface crosslinking efficiency, it is preferable to include at least one alkylene carbonate compound in the surface crosslinking agent, and more preferably ethylene carbonate may be used.
  • the amount of the surface crosslinking agent to be added may be appropriately selected depending on the kind or reaction conditions of the surface crosslinking agent to be added, but it is usually about 0.001 to 100 parts by weight based on 100 parts by weight of the polymer having a particle diameter of 150 to 850 im About 5 parts by weight, preferably about 0.01 to about 3 parts by weight, more preferably about 0.05 to about 2 parts by weight can be used.
  • the surface crosslinking may be a surface crosslinking reaction for 10 minutes to 100 minutes at a temperature of 150 ° C to 300 ° C. That is, the surface crosslinking reaction may be performed by heating a mixture of a polymer having a particle size of 150 to 850 to which a surface crosslinking agent is added and the fine powder reassembly, and drying may be performed together.
  • the temperature raising means for surface crosslinking reaction is not specifically limited. It can be heated by supplying a heat medium or by directly supplying a heat source.
  • a heated fluid such as steam, hot air, or hot oil may be used.
  • the present invention is not limited thereto, and the silver content of the heat medium to be supplied is a means of heating medium, a temperature rising rate, and a temperature increase. It may be appropriately selected in consideration of the target temperature.
  • the heat source directly supplied may be a heating method through electricity, a gas heating method, the present invention is not limited to the above examples.
  • the superabsorbent polymer having improved permeability can be prepared without increasing the water retention capacity or the pressurized absorbent capacity by increasing the foaming strength of the fine powder reassembly.
  • FIG. 1 is a scanning electron microscope (SEM) photograph of Preparation Example 1.
  • a fine powder reassembled product was obtained in the same manner as in Production Example 1, except that 40 g of cold water was sprayed with mi 40 g of fine powder of 150! M or less.
  • a fine powder reassembled product was obtained in the same manner as in Preparation Example 1, except that 50 g of hot water was sprayed while mixing 40 g of fine powder of 150 im or less.
  • a fine powder reassembled product was obtained in the same manner as in Preparation Example 1, except that 40 g of fine powder of 150 im or less was injected with mi xi ng and 40 g of hot water was sprayed.
  • Comparative Production Example 3 A ⁇ reassembled product was obtained in the same manner as in Preparation Example 1, except that 40 g of a powder of 150 m or less was added with a spray of hot water 30 g.
  • the monomer composition was irradiated with ultraviolet light for 1 minute with a 10 mV UV lamp light source in a chamber having an internal temperature of 80 ° C., and polymerization reaction was performed in a non-light source state for 2 minutes. After the polymerization reaction was cut into particles of 10 kPa or less using a meat chopper, and dried at 180 ° C. for 30 minutes using a hot air dryer. Thereafter, the resultant was ground and classified to obtain a super absorbent base resin having a particle diameter of 150 to 850.
  • Superabsorbent polymer was obtained in the same manner as in Example 1, except that the surface crosslinking was performed at 180 ° C. for 60 minutes. Comparative Example 1
  • a super absorbent polymer was obtained in the same manner as in Example 1, except that 70 g of the base resin of Example 1 and 30 g of the fine powder reassembly of Comparative Example 1 were mixed and subjected to surface crosslinking at 180 ° C. for 40 minutes.
  • a super absorbent polymer was obtained in the same manner as in Example 1, except that 70 g of the base resin of Example 1 and 30 g of the fine powder reassembly of Comparative Preparation Example 1 were mixed and subjected to surface crosslinking at 180 ° C. for 60 minutes.
  • the superabsorbent polymer was obtained in the same manner as in Example 1, except that the surface recrosslinking was carried out at 180 ° C. for 40 minutes using 100 g of the base resin of Example 1 without mixing the fine powder reassembly.
  • a superabsorbent polymer was obtained in the same manner as in Example 1, except that the fine powder reassembled was not mixed and surface crosslinking was performed at 180 ° C. for 60 minutes using 100 g of the base resin of Example 1.
  • the resin W (g) (about O. lg) obtained in Examples and Comparative Examples was uniformly sealed in a nonwoven fabric bag, and then immersed in 0.9% by mass of physiological saline at room temperature. After 30 minutes, the envelope was centrifuged and drained at 250 G for 3 minutes, and then the mass W2 (g) of the envelope was measured. Moreover, after carrying out the same operation without using resin, the mass W1 (g) at that time was measured. Using each mass obtained, CRC (g / g) was computed according to the following formula.
  • the water-soluble components were measured in the same manner as the procedure disclosed in the EDANA method WSP 270.2 and listed in Table 3.
  • the neutralization degree referred to in the present invention is a neutralization value calculated by an equation calculated at the time of measuring the aqueous component.
  • Runner electron microscopy (SEM) images of fine powder reassembly 1 to 3 are photographs of the fine powder reassembles according to Preparation Examples 1 to 2 and Comparative Preparation Example 3, respectively, with a scanning electron microscope (SEM).
  • XT2plus equipment from Text Analyzer was used to measure the force of the superabsorbent polymer single particles at a constant speed of 0.01 mm / s into a cylinder of 8 mm in diameter. As the device descends, the force of the superabsorbent polymer increases gradually, and when a certain amount is exceeded, crushing occurs. At this time, the maximum force that the particles endure is defined as crushing strength (kg 'Force), and after 10 measurements, a normal distribution curve is drawn. The average was obtained after excluding%. And this average value is described in Table 3.
  • a simple method of measuring Absorbency Under Pressure is as follows.
  • a stainless steel 400 mesh wire mesh was mounted on the bottom of a 60-mm inner plastic cylinder.
  • the piston which can evenly spray 0.90 g of the absorbent resin onto the wire mesh under the condition of room temperature and humidity of 5 OT, and further give a lowering of 4.83 kPa (0.7 ps i) on it, has an outer diameter of 60 kPa. It is slightly smaller and has no gaps with the inner wall of the cylinder, and the up and down movement is not disturbed. At this time, the weight Wa (g) of the apparatus was measured.
  • a glass filter having a diameter of 90 mm and a thickness of 5 mm was placed inside a petri dish having a diameter of 150 mm 3, and the physiological saline consisting of 0.90 weight> sodium chloride was set to the same level as the upper surface of the glass filter.
  • One sheet of filter paper having a diameter of 90 mm was loaded thereon. Put the measuring device on the filter paper and load the liquid Absorbed for 1 hour. After 1 hour, the measuring device was lifted and the weight Wb (g) was measured.
  • AUP (g / g) [Wb (g)-Wa (g)] / mass of absorbent resin (g)
  • SFC physiological saline flow inducible refers to the permeability of 0.69% by weight aqueous sodium chloride solution to an absorbent resin under a 2.07 kPa load and is measured in accordance with the SFC test method described in US Pat. No. 5669894 and listed in Table 4.
  • Examples 1 to 2 have a high solution permeability (SFC) value because the assembly strength of the fine powder reassembly is increased to decrease the amount of particle size down during transport, grinding, and surface crosslinking, thereby maintaining pores.
  • SFC solution permeability

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Abstract

The present invention relates to a method for preparing a superabsorbent polymer. Specifically, according to the present invention, the method for preparing a superabsorbent polymer comprises the steps of: forming a hydrogel polymer by carrying out thermal polymerization or photopolymerization of a monomer composition containing a water-soluble ethylenically unsaturated monomer and a polymerization initiator; drying the hydrogel polymer; pulverizing the dried polymer; classifying, according to a diameter, the pulverized polymer into a fine powder having a diameter less than 150 μm and a polymer having a diameter of 150-850 μm; carrying out wet-regranulation by mixing 50-200 parts by weight of water of 5-30°C on the basis of 100 parts by weight of the fine powder having a diameter less than 150 μm; and carrying out surface cross-linking by mixing the polymer having a diameter of 150-850 μm and the regranulated fine powder, thereby enabling a superabsorbent polymer having high fine powder cohesive strength to be obtained.

Description

【명세서】  【Specification】
【발명의 명칭】  [Name of invention]
고흡수성 수지의 제조 방법 【기술분야】  Manufacturing Method of Super Absorbent Polymer [Technical Field]
관련 출원 (들)과의 상호 인용  Cross Citation with Related Application (s)
본 출원은 2015 년 11 월 3 일자 한국 특허 출원 제 10-2015- 0153879호 및 2016년 10월 31일자 한국 특허 출원 제 10-2016-0142887 에 기초한 우선권의 이익을 주장하며, 해당 한국 특허 출원들의 문헌에 개시된 모든 내용은 본 명세서의 일부로서 포함된다.  This application claims the benefit of priority based on Korean Patent Application No. 10-2015-0153879 filed on November 3, 2015, and Korean Patent Application No. 10-2016-0142887 filed on October 31, 2016. All content disclosed in is included as part of this specification.
본 발명은 고흡수성 수지의 제조 방법에 관한 것이다. 보다 상세하게는, 높은 미분 응집강도를 갖는 고흡수성 수지의 제조방법에 관한 것이다. 【발명의 배경이 되는 기술】  The present invention relates to a method for producing a super absorbent polymer. More specifically, the present invention relates to a method for producing a super absorbent polymer having a high fine powder cohesive strength. [Technique to become background of invention]
고흡수성 수지 (Super Absorbent Polymer , SAP)란 자체 무게의 5 백 내지 1 천 배 정도의 수분을 흡수할 수 있는 기능을 가진 합성 고분자 물질로서， 개발업체마다 SAM(Super Absorbency Mater i al ) , AGKAbsorbent Gel Mater i al ) 등 각기 다른 이름으로 명명하고 있다. 상기와 같은 고흡수성 수지는 생리용구로 실용화되기 시작해서， 현재는 어린이용 종이기저귀 등 위생용품 외에 원예용 토양보수제， 토목， 건축용 지수재， 육묘용 시트， 식품유통분야에서의 신선도 유지제， 및 찜질용 등의 재료로 널리 사용되고 있다.  Super Absorbent Polymer (SAP) is a synthetic polymer material capable of absorbing water of 500 to 1,000 times its own weight. Are named differently. Such super absorbent polymers have been put into practical use as physiological tools, and are currently used in gardening, soil repair agents, civil engineering, building index materials, seedling sheets, food fresheners in addition to hygiene products such as paper diapers for children, and It is widely used as a material for steaming.
상기와 같은 고흡수성 수지를 제조하는 방법으로는 역상현탁중합에 의한 방법 또는 수용액 중합에 의한 방법 등이 알려져 있다. 역상현탁중합에 대해서는 예를 들면 일본 특개소 56-161408， 특개소 5그 158209 , 및 특개소 57-198714 등에 개시되어 있다. 수용액 중합에 의한 방법으로는 또 다시, 여러 개의 축을 구비한 반죽기 내에서 중합겔을 파단， 넁각하면서 중합하는 열중합 방법, 및 고농도 수용액을 벨트상에서 자외선 등을 조사하여 중합과 건조를 동시에 행하는 광중합 방법 등이 알려져 있다. 상기와 같은 중합 반웅을 거쳐 얻은 함수겔상 중합체는 일반적으로 건조공정을 거쳐 분쇄한 뒤 분말상의 제품으로 시판된다. As a method for producing such a super absorbent polymer, a method by reverse phase suspension polymerization or a method by aqueous solution polymerization is known. Reverse phase suspension polymerization is disclosed in, for example, Japanese Patent Laid-Open No. 56-161408, Japanese Patent Laid-Open No. 158209, Japanese Patent Laid-Open No. 57-198714, and the like. As a method of aqueous solution polymerization, a thermal polymerization method of breaking and staggering a polymerization gel in a kneader having several shafts and a photopolymerization method of simultaneously performing polymerization and drying by irradiating ultraviolet rays or the like on a belt with a high concentration of aqueous solution Etc. are known. The hydrous gel polymer obtained through the polymerization reaction as described above is generally pulverized through a drying process and then marketed as a powder product.
이때 건조된 중합체의 절단， 분쇄 및 분말화 단계 동안 약 150 βΆ 이하의 입자 크기를 갖는 미분 ( f ines)이 발생될 수 있다. 상기 미분을 포함하여 제조된 고흡수성 중합체 입자를 제품에 적용시 사용 전에 이동되거나 저하된 물성을 나타낼 수 있기 때문에 유아용 기저귀 및 성인용 요실금 기구를 포함하는 위생 물품에서 바람직하지 않은 것으로 여겨진다. 따라서， 최종 수지 제품 내 미분이 포함되지 않도록 배제시키거나 상기 미분들을 정상 입자 크기가 되도록 응집시키는 재조립 과정을 거치는데， 재조립 중합체의 응집강도가 낮아 다시 미분으로 파쇄되는 경우가 많다.  At this time, f ines having a particle size of less than about 150 βΆ may be generated during the cutting, grinding and powdering of the dried polymer. It is considered undesirable in hygiene articles including infant diapers and adult incontinence devices because the superabsorbent polymer particles prepared including the fine powder may exhibit physical properties that have been transferred or degraded prior to use when applied to the product. Therefore, the reassembling process of excluding the fine powder in the final resin product or aggregating the fine powder to a normal particle size is often performed, and the coagulation strength of the reassembled polymer is often broken down into fine powder again.
이에 따라， 높은 미분 웅집강도를 가져 재조립 중합체의 미분 발생를을 감소시킬 수 있는 고흡수성 수지의 제조 방법에 대한 연구가 여전히 필요하다.  Accordingly, there is still a need for research on a method of preparing a super absorbent polymer which can have high fine powder forming strength and can reduce fine powder generation of the reassembled polymer.
【발명의 내용] [Contents of the Invention]
【해결하고자 하는 과제】  Problem to be solved
본 발명은 미분 재조립체의 웅집강도를 증가시킴으로써 보수능 또는 가압 흡수능의 저하 없이 투과도가 향상된 고흡수성 수지의 제조방법에 관한 것이다.  The present invention relates to a method for producing a superabsorbent polymer having improved permeability without increasing water retention capacity or pressure absorption capacity by increasing the foaming strength of the fine powder reassembly.
【과제의 해결 수단】 [Measures of problem]
본 발명은 수용성 에틸렌계 불포화 단량체 및 중합개시제를 포함하는 모노머 조성물에 열중합' 또는 광중합을 진행하여 함수겔상 중합체를 형성하는 단계; 상기 함수겔상 중합체를 건조하는 단계; 건조된 중합체를 분쇄하는 단계; 상기 분쇄된 중합체를 입경에 따라 150 m 미만의 입경을 갖는 미분과， 150 내지 850 IM 의 입경을 갖는 중합체로 분급하는 단계; 상기 150 이하의 입경을 갖는 미분 100 중량부에 대하여 5 내지 30°C의 물을 50 내지 200 중량부 흔합하여 습윤시켜 재조립하는 단계; 및 상기 150 내지 850 urn 의 입경을 갖는 중합체와 미분 재조립체를 흔합하여 표면 가교하는 단계;를 포함하는 고흡수성 수지의 제조 방법을 제공한다. The present invention comprises the steps of thermal polymerization ' or photopolymerization to the monomer composition comprising a water-soluble ethylenically unsaturated monomer and a polymerization initiator to form a hydrogel polymer; Drying the hydrogel polymer; Pulverizing the dried polymer; Classifying the ground polymer into fine powder having a particle size of less than 150 m and a polymer having a particle size of 150 to 850 IM depending on the particle size; 50 to 200 parts by weight of mixed water of 5 to 30 ° C. with respect to 100 parts by weight of fine powder having a particle diameter of 150 or less, and reassembly; And above 150 It provides a method for producing a superabsorbent polymer comprising a; and a surface crosslinking a polymer having a particle diameter of 850 urn and fine powder reassembly.
이하 발명의 구체적인 구현예에 따른 고흡수성 수지의 제조 방법에 관하여 보다 상세하게 설명하기로 한다.  Hereinafter, a method of preparing a super absorbent polymer according to a specific embodiment of the present invention will be described in detail.
- 발명의 일 구현예에 따르면， 수용성 에틸렌계 불포화 단량체 및 중합개시제를 포함하는 모노머 조성물에 열중합 또는 광중합을 진행하여 함수겔상 중합체를 형성하는 단계; 상기 함수겔상 중합체를 건조하는 단계; 건조된 중합체를 분쇄하는 단계; 상기 분쇄된 중합체를 입경에 따라 150 IM 미만의 입경을 갖는 미분과， 150 내지 850 의 입경을 갖는 중합체로 분급하는 단계; 상기 150 im 이하의 입경을 갖는 미분 100 중량부에 대하여 5 내지 30 °C의 물을 50 내지 200 중량부 흔합하여 습윤시켜 재조립하는 단계; 및 상기 150 내지 850 m 의 입경을 갖는 중합체와 미분 재조립체를 흔합하여 표면 가교하는 단계;를 포함하는 고흡수성 수지의 제조 방법이 제공될 수 있다. 상기 일 구현예의 고흡수성 수지의 제조 방법에서， 상기 고흡수성 수지의 원료 물질인 모노머 조성물은 수용성 에틸렌계 불포화 단량체 및 중합 개시제를 포함한다. According to one embodiment of the invention, a step of thermally polymerizing or photopolymerizing a monomer composition comprising a water-soluble ethylenically unsaturated monomer and a polymerization initiator to form a hydrogel polymer; Drying the hydrogel polymer; Pulverizing the dried polymer; Classifying the pulverized polymer into fine powder having a particle size of less than 150 IM and a polymer having a particle size of 150 to 850 depending on the particle size; Reassembling by mixing 50 to 200 parts by weight of water at a temperature of 5 to 30 ° C with respect to 100 parts by weight of fine powder having a particle diameter of 150 im or less; And a surface crosslinking of the polymer having a particle diameter of 150 to 850 m and the fine powder reassembly, may be provided. In the manufacturing method of the super absorbent polymer of the embodiment, the monomer composition which is a raw material of the super absorbent polymer includes a water-soluble ethylenically unsaturated monomer and a polymerization initiator.
상기 수용성 에틸렌계 불포화 단량체는 고흡수성 수지의 제조에 통상 사용되는 임의의 단량체를 별다른 제한 없이 사용할 수 있다. 여기에는 음이온성 단량체와 그 염, 비이온계 친수성 함유 단량체 및 아미노기 함유 불포화 단량체 및 그의 4 급화물로 이루어진 군에서 선택되는 어느 하나 이상의 단량체를 사용할 수 있다. _  The water-soluble ethylenically unsaturated monomer may be used without any limitation any monomers commonly used in the production of superabsorbent polymers. Any one or more monomers selected from the group consisting of anionic monomers and salts thereof, nonionic hydrophilic-containing monomers and amino group-containing unsaturated monomers and quaternized compounds thereof can be used. _
구체적으로는 (메타)아크릴산， 무수말레인산, 푸말산， 크로톤산， 이타콘산， 2ᅳ아크릴로일에탄 술폰산， 2-메타아크릴로일에탄술폰산， 2- (메타)아크릴로일프로판술폰산 또는 2- (메타)아크릴아미드 -2-메틸 프로판 술폰산의 음이온성 단량체와 그 염; (메타)아크릴아미드， N- 치환 (메타)아크릴레이트， 2-히드록시에틸 (메타)아크릴레이트， 2- 히드록시프로필 (메타)아크릴레이트， 메특시폴리에틸렌글리콜 (메타)아크릴레이트 또는 폴리에틸렌 글리콜 (메타)아크릴레이트의 비이온계 친수성 함유 단량체; 및 (Ν,Ν)- 디메틸아미노에틸 (메타) 아크릴레이트 또는 (Ν ,Ν)- 디메틸아미노프로필 (메타)아크릴아미드의 아미노기 함유 불포화 단량체 및 그의 4급화물로 이루어진 군에서 선택된 어느 하나 이상을 사용할 수 있다. 더욱 바람직하게는 아크릴산 또는 그 염， 예를 들어， 아크릴산 또는 그 나트륨염 등의 알칼리 금속염을 사용할 수 있는데, 이러한 단량체를 사용하여 보다 우수한 물성을 갖는 고흡수성 수지의 제조가 가능해 진다. 상기 아크릴산의 알칼리 금속염을 단량체로 사용하는 경우， 아크릴산을 가성소다 (NaOH)와 같은 염기성 화합물로 중화시켜 사용할 수 있다. Specifically, (meth) acrylic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid, diacryloylethane sulfonic acid, 2-methacryloylethanesulfonic acid, 2- (meth) acryloylpropanesulfonic acid, or 2- Anionic monomers of (meth) acrylamide-2-methyl propane sulfonic acid and salts thereof; (Meth) acrylamide, N- substituted (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, Nonionic hydrophilic-containing monomers of methypolyethylene glycol (meth) acrylate or polyethylene glycol (meth) acrylate; And amino group-containing unsaturated monomers of (Ν, Ν) -dimethylaminoethyl (meth) acrylate or (Ν, Ν) -dimethylaminopropyl (meth) acrylamide and quaternized compounds thereof. Can be. More preferably, alkali metal salts such as acrylic acid or salts thereof, for example acrylic acid or sodium salts thereof, may be used. The use of such monomers enables the production of superabsorbent polymers having better physical properties. When the alkali metal salt of acrylic acid is used as a monomer, acrylic acid may be neutralized with a basic compound such as caustic soda (NaOH).
상기 수용성 에틸렌계 불포화 단량체의 농도는， 상기 고흡수성 수지의 원료 물질 및 용매를 포함하는 단량체 조성물에 대해 약 20 내지 약 60 중량 %， 바람직하게는 약 40 내지 약 50 중량 %로 될 수 있으며， 중합 시간 및 반응 조건 등을 고려해 적절한 농도로 될 수 있다. 다만, 상기 단량체의 농도가 지나치게 낮아지면 고흡수성 수지의 수율이 낮고 경제성에 문제가 생길 수 있고， 반대로 농도가 지나치게 높아지면 단량체의 일부가 석출되거나 중합된 함수겔상 중합체의 분쇄 시 분쇄 효율이 낮게 나타나는 등 공정상 문제가 생길 수 있으며 고흡수성 수지의 물성이 저하될 수 있다. 또한， 상기 중합 개시제는 고흡수성 수지의 제조에 일반적으로 사용되는 것이면 특별히 한정되지 않으며， 중합 방법에 따라 열중합 개시제 또는 UV 조사에 따른 광중합 개시제를 사용할 수 있다. 다만 광중합 방법에 의하더라도， 자외선 조사 등의 조사에 의해 일정량의 열이 발생하고， 또한 발열 반웅인 중합 반웅의 진행에 따라 어느 정도의 열이 발생하므로， 추가적으로 열중합 개시제를 포함할 수도 있다.  The concentration of the water-soluble ethylenically unsaturated monomer may be about 20 to about 60% by weight, preferably about 40 to about 50% by weight, based on the monomer composition including the raw material and the solvent of the superabsorbent polymer. The concentration may be appropriate in consideration of time and reaction conditions. However, when the concentration of the monomer is too low, the yield of the superabsorbent polymer may be low and there may be a problem in economics. On the contrary, when the concentration is too high, some of the monomer may be precipitated or the grinding efficiency of the polymerized hydrogel polymer may be low. Etc. may cause problems in the process and may decrease the physical properties of the super absorbent polymer. In addition, the polymerization initiator is not particularly limited as long as it is generally used for the production of superabsorbent polymers, and may be a thermal polymerization initiator or a photopolymerization initiator according to UV irradiation depending on the polymerization method. However, even by the photopolymerization method, since a certain amount of heat is generated by irradiation of ultraviolet radiation or the like, and a certain amount of heat is generated in accordance with the progress of the polymerization reaction, which is an exothermic reaction, it may further include a thermal polymerization initiator.
상기 광중합 개시제는 자외선과 같은 광에 의해 라디칼을 형성할 수 있는 화합물이면 그 구성의 한정이 없이 사용될 수 있다.  The photopolymerization initiator may be used without any limitation as long as it is a compound capable of forming radicals by light such as ultraviolet rays.
, 상기 광중합 개시제로는 예를 들어， 벤조인 에테르 (benzoin ether ) , 디알킬아세토페논 (di alkyl acetophenone) , 하이드록실 알킬케톤 (hydroxyl alkylketone) , 페닐글리옥실레이트 (phenyl glyoxyl ate) , 벤질디메틸케탈 (Benzyl Dimethyl Ketal ) , 아실포스핀 (acyl phosphine) 및 알파 -아미노케톤 ( α-aminoketone)으로 이루어진 군에서 선택되는 하나 이상을 사용할 수 있다. 한편， 아실포스핀의 구체예로， 상용하는 lucirin TP0, 즉， 2，4，6-트리메틸 -벤조일-트리메틸 포스핀 옥사이드 (2，4，6- trimethyl-benzoyl-tr imethyl phosphine oxide)¾- 사용할- 수 있다. 보다 다양한 광개시제에 대해서는 Reinhold Schwa lm 저서인 "UV Coatings: Basics , Recent Developments and New Appl icat ion(Elsevier 2007 년)" pll5에 잘 명시되어 있으며， 상술한 예에 한정되지 않는다. As the photopolymerization initiator, for example, benzoin ether, dialkyl acetophenone, hydroxyl alkylketone, phenylglyoxylate, benzyldimethyl ketal (Benzyl Dimethyl Ketal), acyl phosphine and One or more selected from the group consisting of alpha-aminoketone may be used. Meanwhile, as an embodiment of acylphosphine, commercially available lucirin TP0, that is, 2,4,6-trimethyl-benzoyl-trimethyl phosphine oxide (2,4,6-trimethyl-benzoyl-tr imethyl phosphine oxide) ¾- can be used. -You can. A wider variety of photoinitiators are well specified in Reinhold Schwalm lm "UV Coatings: Basics, Recent Developments and New Application (Elsevier 2007)" pll5, and are not limited to the examples described above.
상기 광중합 개시제는 상기 모노머 조성물에 대하여 약 0.01 내지 약 1.0 중량 %의 농도로 포함될 수 있다. 이러한 광중합 개시제의 농도가 지나치게 낮을 경우 중합 속도가 느려질 수 있고， 광중합 개시제의 농도가 지나치게 높으면 고흡수성 수지의 분자량이 작고 물성이 불균일해질 수 있다.  The photopolymerization initiator may be included in a concentration of about 0.01 to about 1.0 wt% based on the monomer composition. When the concentration of the photopolymerization initiator is too low, the polymerization rate may be slow. When the concentration of the photopolymerization initiator is too high, the molecular weight of the superabsorbent polymer may be low and the physical properties may be uneven.
또한, 상기 열중합 개시제로는 과황산염계 개시제， 아조계 개시게， 과산화수소 및 아스코르빈산으로 이루어진 개시제 군에서 선택되는 하나 이상을 사용할 수 있다. 구체적으로， 과황산염계 개시제의 예로는 과황산나트륨 (Sodium persulfate; Na2S208) , 과황산칼륨 (Potassium persulfate; K2S208) , 과황산암모늄 (Ammonium persulfate; (NH4)2S2(¾) 등이 있으며， 아조 (Azo)계 개시제의 예로는 2， 2-아조비스 -(2- 아미디노프로판)이염산염 (2， 2-azob i s ( 2-am i d i nopr opane ) dihydrochlor ide) : 2， 2-아조비스 -(N, N-디메틸렌)이소부티라마이딘 디하이드로클로라이드 (2 , 2-azobis-(N, N— dimethyl ene) i sobuty rami dine dihydrochloride), 2— (카바모일아조)이소부티로니트릴 (2-In addition, the thermal polymerization initiator may be used at least one selected from the group consisting of persulfate initiator, azo initiator, hydrogen peroxide and ascorbic acid. Specifically, examples of persulfate-based initiators include sodium persulfate (Na 2 S 2 0 8 ), potassium persulfate (K 2 S 2 0 8 ), ammonium persulfate (NH 4 ) 2 S2 (¾), and examples of azo initiators include 2, 2-azobis- (2-amidinopropane) dihydrochloride (2, 2-azob is (2-am idi nopr opane) dihydrochlor ide) : 2, 2-azobis- (N, N-dimethylene) isobutyramidine dihydrochloride (2, 2-azobis- (N, N—dimethyl ene) i sobuty rami dine dihydrochloride), 2— ( Carbamoyl azo) isobutyronitrile (2-
( car bamoy 1 azo ) i sobut y 1 oni t r i 1 ) , 2, 2-아조비스 [2-(2—이미다졸린 -2- 일 )프로판] 디하이드로클로라이드 (2 ,2-azobi s[2-(2-imidazol in-2- yDpropane] dihydrochloride), 4,4-아조비스 -(4-시아노발레릭 산) (4,4- azobis-(4-cyanovaleric acid)) 등이 있다. 보다 다양한 열중합 개시제에 대해서는 Odian 저서인 'Principle of Polymer izat ion(Wi ley , 1981)' , p203에 잘 명시되어 있으며， 상술한 예에 한정되지 않는다 . (car bamoy 1 azo) i sobut y 1 oni tri 1), 2, 2-azobis [2- (2—imidazolin-2-yl) propane] dihydrochloride (2,2-azobi s [2- (2-imidazol in-2-yDpropane) dihydrochloride), 4,4-azobis- (4-cyanovaleric acid) (4,4-azobis- (4-cyanovaleric acid)), etc. More heat The polymerization initiator is well specified in Odian's Principle of Polymer izat ion (Wi ley, 1981), p203, and is not limited to the examples described above.
상기 열중합 개시제는 상기 모노머 조성물에 대하여 약 0.001 내지 약 0.5 중량 %의 농도로 포함될 수 있다. 이러한 열 중합 개시제의 농도가 지나치게 낮을 경우 추가적인 열중합이 거의 일어나지 않아 열중합 개시제의 추가에 따른 효과가 미미할 수 있고, 열중합 개시제의 농도가 지나치게 높으면 고흡수성 수지의 분자량이 작고 물성이 불균일해질 수 있다. The thermal polymerization initiator may be included in a concentration of about 0.001 to about 0.5% by weight based on the monomer composition. The concentration of this thermal polymerization initiator When too low, additional thermal polymerization hardly occurs, so that the effect of the addition of the thermal polymerization initiator may be insignificant. When the concentration of the thermal polymerization initiator is too high, the molecular weight of the superabsorbent polymer may be small and the physical properties may be uneven.
또한， 상기 모노머 조성물은 고흡수성 수지의 원료 물질로서 내부 가교제를 더 포함할 수 있다. 상기 내부 가교제로는 상기 수용성 에틸렌계 불포화 단량체의 수용성 치환기와 반웅할 수 있는 관능기를 1 개 이상 가지면서， 에틸렌성 불포화기를 1 개 이상 갖는 가교제 ; 혹은 상기 단량체의 수용성 치환기 및 /또는 단량체의 가수분해에 의해 형성된 수용성 치환기와 반웅할 수 있는 관능기를 2개 이상 갖는 가교제를 사용할 수 있다.  In addition, the monomer composition may further include an internal crosslinking agent as a raw material of the super absorbent polymer. Examples of the internal crosslinking agent include a crosslinking agent having at least one ethylenically unsaturated group while having at least one functional group capable of reacting with the water-soluble substituent of the water-soluble ethylenically unsaturated monomer; Alternatively, a crosslinking agent having two or more water-soluble substituents and / or functional groups capable of reacting with the water-soluble substituents formed by hydrolysis of the monomers may be used.
상기 내부 가교제의 구체적인 예로는， 탄소수 8 내지 12 의 비스아크릴아미드， 비스메타아크릴아미드， 탄소수 2 내지 10 의 폴리을의 폴리 (메타)아크릴레이트 또는 탄소수 2 내지 10 의 폴리올의 폴리 (메타)알릴에테르 등을 들 수 있고， 보다 구체적으로， N , Ν ' - 메틸렌비스 (메타)아크릴레이트， 에틸렌옥시 (메타)아크릴레이트， 폴리에틸렌옥시 (메타)아크릴레이트, 프로필렌옥시 (메타)아크릴레이트， 글리세린 디아크릴레이트， 글리세린 트리아크릴레이트, 트리메티를 트리아크릴레이트, 트리알릴아민， 트리아릴시아누레이트， 트리알릴이소시아네이트， 폴리에틸렌글리콜， 디에틸렌글리콜 및 프로필렌글리콜로 이루어진 군에서 선택된 하나 이상을 사용할 수 있다. 이러한 내부 가교제는 상기 모노머 조성물에 대하여 약 0.01 내지 약0.5 중량 %의 농도로 포함되어， 중합된 고분자를 가교시킬 수 있다.  Specific examples of the internal crosslinking agent include bisacrylamide having 8 to 12 carbon atoms, bismethacrylamide, poly (meth) acrylate having 2 to 10 carbon atoms or poly (meth) allyl ether having 2 to 10 carbon atoms. More specifically, N, Ν'- methylenebis (meth) acrylate, ethyleneoxy (meth) acrylate, polyethyleneoxy (meth) acrylate, propyleneoxy (meth) acrylate, glycerin diacrylate Glycerol triacrylate, trimethy triacrylate, triallylamine, triaryl cyanurate, triallyl isocyanate, polyethylene glycol, diethylene glycol and propylene glycol may be used. Such an internal crosslinking agent may be included in a concentration of about 0.01 wt% to about 0.5 wt% based on the monomer composition to crosslink the polymerized polymer.
또한， 상기 일 구현예의 고흡수성 수지 제조 방법의 모노머 조성물은 필요에 따라 증점제 (thi ckener ) , 가소제， 보존안정제, 산화방지제 등의 첨가제를 더 포함할 수 있다.  In addition, the monomer composition of the superabsorbent polymer production method of the embodiment may further include additives such as a thickener, a plasticizer, a storage stabilizer, an antioxidant, and the like, as necessary.
상술한 수용성 에틸렌계 불포화 단량체， 광중합 개시제， 열증합 개시제， 내부 가교제 및 첨가제와 같은 원료 물질은 용매에 용해된 모노머 조성물 용액의 형태로 준비될 수 있다.  Raw materials such as the above-mentioned water-soluble ethylenically unsaturated monomers, photopolymerization initiators, thermal polymerization initiators, internal crosslinking agents and additives may be prepared in the form of a monomer composition solution dissolved in a solvent.
이 때 사용할 수 있는 상기 용매는 상술한 성분들을 용해할 수 있으면 그 구성의 한정이 없이 사용될 수 있으며， 예를 .들어 물， 에탄을， 에틸렌글리콜， 디에틸렌글리콜， 트리에틸렌글리콜， 1，4-부탄디올， 프로필렌글리콜， 에틸렌글리콜모노부틸에테르， 프로필렌글리콜모노메틸에테르， 프로필렌글리콜모노메틸에테르아세테이트， 메틸에틸케톤， 아세톤， 메틸아밀케톤， 시클로핵사논, 시클로펜타논， 디에틸렌글리콜모노메틸에테르, 디에틸렌글리콜에틸에테르, 를루엔， 크실렌, 부틸로락톤， 카르비를， 메틸샐로솔브아세테이트 및 N, N- 디메틸아세트아미드 등에서 선택된 1종 이상을 조합하여 사용할 수 있다. 상기 용매는 모노머 조성물의 총 함량에 대하여 상술한 성분을 제외한 잔량으로 포함될 수 있다. The solvent that can be used at this time can be used without limitation in the composition as long as it can dissolve the above-mentioned components, for example, water, ethane, Ethylene glycol, diethylene glycol, triethylene glycol, 1,4-butanediol, propylene glycol, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl ethyl ketone, acetone, methyl amyl ketone, cyclo 1 type selected from nucleanone, cyclopentanone, diethylene glycol monomethyl ether, diethylene glycol ethyl ether, toluene, xylene, butyrolactone, carbyl, methyl salosolve acetate, and N, N-dimethylacetamide The above can be used in combination. The solvent may be included in the remaining amount except for the above-described components with respect to the total content of the monomer composition.
. 한편， 이와 같은 모노머 조성물을 열중합 또는 광중합하여 함수겔상 중합체를 형성하는 방법 또한 통상 사용되는 중합 방법이면， 특별히 구성의 한정이 없다.  . On the other hand, the method of forming a hydrogel polymer by thermally polymerizing or photopolymerizing such a monomer composition is not particularly limited as long as it is a commonly used polymerization method.
구체적으로， 중합 방법은 중합 에너지원에 따라 크게 열중합 및 광중합으로 나뉘며, 통상 열중합을 진행하는 경우， 니더 (kneader )와 같은 교반축을 가진 반웅기에서 진행될 수 있으며， 광중합을 진행하는 경우， 이동 가능한 컨베이어 벨트를 구비한 반웅기에서 진행될 수 있으나， 상술한 중합 방법은 일 예이며， 본 발명은 상술한 증합 방법에 한정되지는 않는다. 일 예로, 상술한 바와 같이 교반축을 구비한 니더 (kneader )와 같은 반웅기에, 열풍을 공급하거나 반웅기를 가열하여 열중합을 하여 얻어진 함수겔상 중합체는 반응기에 구비된 교반축의 형태에 따라， 반웅기 배출구로 배출되는 함수겔상 중합체는 수 센티미터 내지 수 밀리미터 형태일 수 있다. 구체적으로， 얻어지는 함수겔상 중합체의 크기는 주입되는 모노머 조성물의 농도 및 주입속도 등에 따라 다양하게 나타날 수 있는데， 통상 중량 평균 입경이 2 내지 50 隱 인 함수겔상 중합체가 얻어질 수 있다. 또한， 상술한 바와 같이 이동 가능한 컨베이어 벨트를 구비한 반응기에서 광중합을 진행하는 경우， 통상 얻어지는 함수겔상 중합체의 형태는 벨트의 너비를 가진 시트 상의 함수겔상 중합체일 수 있다. 이 때， 중합체 시트의 두께는 주입되는 단량체 조성물의 농도 및 주입속도에 따라 달라지나， 통상 약 0.5 내지 약 5cm 의 두께를 가진 시트 상의 중합체가 얻어질 수 있도록 단량체 조성물을 공급하는 것이 바람직하다. 시트 상의 중합체의 두께가 지나치게 얇을 정도로 단량체 조성물을 공급하는 경우， 생산 효율이 낮아 바람직하지 않으며 , 시트 상의 중합체 두께가 5cm 를 초과하는 경우에는 지나치게 두꺼운 두께로 인해， 중합 반응이 전 두께에 걸쳐 고르게 일어나지 않을 수가 있다. Specifically, the polymerization method is largely divided into thermal polymerization and photopolymerization according to the polymerization energy source, and when the thermal polymerization is usually carried out, it can be carried out in a semi-unggi with a stirring shaft such as kneader, when the polymerization proceeds, Although it can proceed in a semi-unggi equipped with a conveyor belt possible, the above-described polymerization method is an example, the present invention is not limited to the above-described polymerization method. For example, as described above, the hydrogel polymer obtained by thermal polymerization by supplying hot air or by heating the reaction vessel may be a semi-ungker, such as a kneader having a stirring shaft, according to the shape of the stirring shaft provided in the reactor. The hydrogel polymer discharged to the outlet may be in the form of several centimeters to several millimeters. Specifically, the size of the water-containing gel polymer obtained may vary depending on the concentration and the injection speed of the monomer composition to be injected, it can be obtained a water-containing gel polymer having a weight average particle diameter of 2 to 50 kPa. In addition, when photopolymerization is carried out in a reactor having a movable conveyor belt as described above, the form of the hydrogel polymer generally obtained may be a hydrogel gel polymer on a sheet having a width of the belt. At this time, the thickness of the polymer sheet depends on the concentration and the injection speed of the monomer composition to be injected, but it is usually preferable to supply the monomer composition so that a polymer on the sheet having a thickness of about 0.5 to about 5 cm is obtained. On the sheet In the case of supplying the monomer composition to such an extent that the thickness of the polymer is too thin, it is not preferable because the production efficiency is low, and when the polymer thickness on the sheet exceeds 5 cm, the polymerization reaction may not occur evenly over the entire thickness due to the excessively thick thickness. have.
이때 이와 같은 방법으로 얻어진 함수겔상 중합체의 통상 함수율은 약 30 내지 약 70 중량 %， .바람직하게는 약 40 내지 약 60 중량 %일 수 있다. 한편， 본 명세서 전체에서 "함수율"은 전체 함수겔상 중합체 중량에 대해 차지하는 수분의 함량으로 함수겔상 중합체의 중량에서 건조 상태의 중합체의 중량을 뺀 값을 의미한다. 구체적으로는， 적외선 가열을 통해 중합체의 온도를 올려 건조하는 과정에서 중합체 중의 수분증발에 따른 무게감소분을 측정하여 계산된 값으로 정의한다. 이때， 건조 조건은 상온에서 약 180°C까지 온도를 상승시킨 뒤 18CTC에서 유지하는 방식으로 총 건조시간은 온도상승단계 5 분을 포함하여 20 분으로 설정하여， 함수율을 측정한다. In this case, the water content of the hydrogel polymer obtained by the above method may be about 30 to about 70 wt%, preferably about 40 to about 60 wt%. On the other hand, "water content" as used throughout the present specification means the content of the water to the total weight of the water-containing gel polymer subtracted from the weight of the water-containing gel polymer minus the weight of the dry polymer. Specifically, it is defined as a value calculated by measuring the weight loss due to moisture evaporation in the polymer in the process of raising the temperature of the polymer through infrared heating and drying. At this time, the drying conditions are raised to a temperature of about 180 ° C at room temperature and then maintained at 18 CTC, the total drying time is set to 20 minutes, including 5 minutes of temperature rise step, the moisture content is measured.
다음에， 얻어진 함수겔상 중합체를 건조한다.  Next, the hydrous gel polymer obtained is dried.
이때 필요에 따라서 상기 건조 단계의 효율을 높이기 위해 건조 전에 조분쇄하는 단계를 더 거칠 수 있다.  At this time, if necessary to coarse grinding before drying to increase the efficiency of the drying step may be more rough.
이때， 사용되는 분쇄기는 구성의 한정은 없으나, 구체적으로， 수직형 절단기 (Vertical pulverizer), 터보 커터 (Turbo cutter), 터보 글라인더 (Turbo grinder), 회전 절단식 분쇄기 (Rotary cutter mill), 절단식 분쇄기 (Cutter mill), 원판 분쇄기 (Disc mill), 조각 파쇄기 (Shred crusher), 파쇄기 (Crusher)， 초퍼 (chopper) 및 원판식 절단기 (Disc cutter)로 이루어진 분쇄 기기 군에서 선택되는 어느 하나를 포함할 수 있으나， 상술한 예에 한정되지는 않는다.  At this time, the pulverizer used is not limited in configuration, but specifically, a vertical pulverizer, a turbo cutter, a turbo grinder, a rotary cutter mill, a cutting machine Any one selected from the group of crushing machines consisting of cutter mills, disc mills, shred crushers, crushers, choppers and disc cutters Although it is possible, it is not limited to the above-mentioned example.
이때 분쇄 단계는 함수겔상 중합체의 입경이 약 2 내지 약 10mm 로 되도록 분쇄할 수 있다. 입경이 2瞧 미만으로 분쇄하는 것은 함수겔상 중합체의 높은 함수율로 인해 기술적으로 용이하지 않으며， 또한 분쇄된 입자 간에 서로 응집되는 현상이 나타날 수도 있다. 한편， 입경이 10隱초과로 분쇄하는 경우， 추후 이루어지는 건조 단계의 효율 증대 효과가 미미하다. 상기와 같이 분쇄되거나， 혹은 분쇄 단계를 거치지 않은 중합 직후의 함수겔상 중합체에 대해 건조를 수행한다. 이때 상기 건조 단계의 건조 온도는 약 150 내지 약 250°C일 수 있다. 건조 온도가 150°C 미만인 경우， 건조 시간이 지나치게 길어지고 최종 형성되는 고흡수성 수지의 물성이 저하될 우려가 있고， 건조 온도가 250°C를 초과하는 경우， 지나치게 중합체 표면만 건조되어， 추후 이루어지는 분쇄 공정에서 미분이 발생할 수도 있고， 최종 형성되는 고흡수성 수지의 물성이 저하될 우려가 있다. 따라서 바람직하게 상기 건조는 약 150 내지 약 20CTC의 온도에서, 더욱 바람직하게는 약 160 내지 약 180°C의 은도에서 진행될 수 있다. At this time, the grinding step may be pulverized so that the particle size of the hydrogel polymer is about 2 to about 10mm. Grinding to a particle diameter of less than 2 μs is not technically easy due to the high water content of the hydrogel polymer, and may also cause agglomeration between the milled particles. On the other hand, when the particle size is pulverized in excess of 10 隱, the effect of increasing the efficiency of the subsequent drying step is insignificant. Drying is performed on the hydrous gel polymer immediately after the polymerization as described above or not subjected to the grinding step. At this time, the drying temperature of the drying step may be about 150 to about 250 ° C. If the drying temperature is less than 150 ° C, the drying time may be too long and the physical properties of the final superabsorbent polymer may be lowered. If the drying temperature is higher than 250 ° C, only the polymer surface is dried excessively. Fine powder may occur in the grinding process, and there is a fear that the physical properties of the superabsorbent polymer to be finally formed decrease. Thus, preferably, the drying may be carried out at a temperature of about 150 to about 20 CTC, more preferably at a silver degree of about 160 to about 180 ° C.
한편, 건조 시간의 경우에는 공정 효율 등을 고려하여， 약 20 내지 약 90분 동안 진행될 수 있으나， 이에 한정되지는 않는다.  On the other hand, in the case of drying time, in consideration of the process efficiency, etc., it may proceed for about 20 to about 90 minutes, but is not limited thereto.
상기 건조 단계의 건조 방법 역시 함수겔상 중합체의 건조 공정으로 통상 사용되는 것이면， 그 구성의 한정이 없이 선택되어 사용될 수 있다. 구체적으로， 열풍 공급, 적외선 조사, 극초단파 조사， 또는 자외선 조사 등의 방법으로 건조 단계를 진행할 수 있다. 이와 같은 건조 단계 진행 후의 중합체의 함수율은 약 0.1 내지 약 10 중량%일 수 있다.  If the drying method of the drying step is also commonly used as a drying step of the hydrogel polymer, it can be selected and used without limitation of the configuration. Specifically, the drying step may be performed by a method such as hot air supply, infrared irradiation, microwave irradiation, or ultraviolet irradiation. The water content of the polymer after the drying step may be about 0.1 to about 10% by weight.
다음에， 이와 같은 건조 단계를 거쳐 얻어진 건조된 중합체를 분쇄하는데， 이는 2 내지 약 10匪로 되도록 분쇄하는 상기 조분쇄 단계와는 구분되는 것으로， 분쇄 단계 후 얻어지는 중합체 분말은 입경이 약 850 im 이하일 수 있다. 이와 같은 입경으로 분쇄하기 위해 사용되는 분쇄기로는 구체적으로， 핀 밀 (pin mill), 해머 밀 (hammer mill), 스크류 밀 (screw mill), 를 밀 (roll mill), 디스크 밀 (disc mill) 또는 조그 밀 (jog mill) 등을 사용할 수 있으나, 상술한 예에 본 발명이 한정되는 것은 아니다.  Next, the dried polymer obtained through such a drying step is pulverized, which is distinguished from the coarse pulverizing step which is pulverized to 2 to about 10 mm 3, and the polymer powder obtained after the pulverizing step has a particle diameter of about 850 im or less. Can be. The grinder used to grind to such a particle size may specifically be a pin mill, hammer mill, screw mill, roll mill, disc mill or A jog mill or the like may be used, but the present invention is not limited to the above-described example.
그리고， 다음으로는 분쇄 후 얻어지는 중합체를 입경에 따라 150 im 미만의 입경을 갖는 미분과， 약 150 내지 약 850 의 입경을 갖는 중합체로 분급한다.  Next, the polymer obtained after grinding is classified into fine powder having a particle size of less than 150 im and a polymer having a particle size of about 150 to about 850 depending on the particle size.
. 본 발명에서는 일정 입자 크기 이하， 즉 약 150 im 미만의 입자 크기를 갖는 미세 입자를 고흡수성 중합체 미분, 중합체 미분， SAP 미분 또는 미분 (fines, fine powder)으로 지칭한다. 상기 미분은 중합 공정, 건조 공정 또는 건조된 중합체의 분쇄 단계 동안 발생될 수 있는데， 제품에 포함될 경우 취급이 어렵고 겔 블로킹 (gel blocking) 현상을 나타내는 등 물성을 저하시키기 때문에 최종 수지 제품에 포함되지 않도록 배제하거나 정상 입자가 되도록 재사용하는 것이 바람직하다. . Fine particles having a particle size below a certain particle size, ie less than about 150 im, are referred to as superabsorbent polymer fine powder, polymer fine powder, SAP fine powder or fine powder (fines, fine powder). The fines can be generated during the polymerization process, the drying process or the grinding of the dried polymer, When included, it is difficult to handle and exhibits a gel blocking phenomenon, thereby deteriorating physical properties. Therefore, it is preferable to exclude them from the final resin product or reuse them to become normal particles.
상기 일 구현예의 제조 방법에서는， 상기 150 μΆ 이하의 입경을 갖는 미분에 5 내지 3( C의 물을 흔합하여 습윤상태에서 재조립한다.  In the manufacturing method of the above embodiment, 5 to 3 (C water is mixed and reassembled in a wet state to a fine powder having a particle size of 150 μΆ or less.
상기 5 내지 30°C의 물은 미분 100 중량부에 대하여 약 50 내지 200 중량부 흔합할 수 있으며， 상기 재조립 단계가 습윤 상태에서 진행되는 것은 재조립체의 웅집강도를 높이기 위해서이다. 이때 물의 함량이 높을수록 미분의 응집강도가 높아지나 재조립 공정시 너무 큰 재조립체 덩어리나 부분적으로 수분을 많이 함유하여 단단하게 뭉쳐진 상태의 재조립체 덩어리 (젤리볼)가 생겨 후속하는 분쇄 공정 운전시 문제가 생길 수 있다. 또한， 물의 함량이 낮으면 재조립 공정은 용이하나 웅집강도가 낮아 재조립 이후 다시 미분으로 파쇄되는 경우가 많다. The water of 5 to 30 ° C may be mixed about 50 to 200 parts by weight with respect to 100 parts by weight of fine powder, the reassembly step is carried out in a wet state to increase the cohesive strength of the reassembly. At this time, the higher the water content, the higher the cohesive strength of the fine powder, but during the reassembly process, too large reassembly lumps or partly water-containing reassembly lumps (jelly balls) are formed and subsequent crushing processes are operated. Problems can arise. In addition, if the water content is low, the reassembly process is easy, but the foaming strength is low, and after reassembly, the powder is often crushed again.
또한, 상기 재조립 단계에서는 미분이 상술한 함수율을 갖는 습윤 상태를 형성하기 위하여 약 5 내지 30°C의 저온의 물을 첨가하며 반응을 진행시킬 수 있다. 이 때， 상기 저은의 물은 조립체의 응집강도를 증가시키는 특징을 갖기 때문에， 약 60°C 이상의 고온의 물을 사용하는 경우에 비하여 건조 및 분쇄 공정 이후에 재미분화 되는 비율이 줄어드는 장점이 있다. In addition, in the reassembling step, the reaction may proceed by adding low temperature water of about 5 to 30 ° C to form a wet state in which the fine powder has the above-mentioned water content. At this time, since the water of the low silver has the characteristic of increasing the cohesive strength of the assembly, there is an advantage that the rate of fungization after the drying and grinding process is reduced compared to the case of using high temperature water of about 60 ° C or more.
이 때， 상기 5 내지 30°C의 물은 미스트 (mi st ) , 스프레이노즐 (spray) 장치 등을 이용하여 상기 미분에 흔합하여 습윤시킬 수 았다. At this time, the water of 5 to 30 ° C was mixed with the fine powder by using a mist (mis st), spray nozzle (spray) device and the like can be wet.
그리고， 상기 재조립 단계에서 미분은 함수율이 약 40 내지 60 중량 %인 습윤 상태에서 재조립 공정을 진행할 수 있다. 상술한 바와 같이 미분과 물을 적정 비율로 흔합하면 미분을 함수율 약 40 내지 60 중량 %로 습윤시킬 수 있으며， 이러한 상태에서 재조립하여， 보다 높은 웅집 강도를 갖는 미분 재조립체를 제조할 수 있다.  In the reassembling step, the fine powder may be reassembled in a wet state having a water content of about 40 to 60 wt%. As described above, when the fine powder and water are mixed at an appropriate ratio, the fine powder may be wetted at a water content of about 40 to 60 wt%, and reassembled in this state, thereby preparing a fine powder reassembly having a higher coarse strength.
다음으로, 상기 150 내지 850 ； ΜΠ 의 입경을 갖는 증합체와 미분 재조립체를 흔합하여 표면 가교한다.  Next, surface-crosslinking is carried out by mixing the above-mentioned polymer with a particle size of 150 to 850; μπι and a fine powder reassembly.
상기 150 내지 850 urn 의 입경을 갖는 중합체는 분쇄된 중합체를 입경에 따라 분급하는 단계에서 도출된 것으로， 정상적인 입경 범위의 중합체에 해당하고， 미분 재조립체는 상기 분급하는 단계에서 도출된 150 μα 미만의 입경을 갖는 미분을 상술한 방법으로 재조립한 재조립체를 의미한다. 이 때， 상기 미분 재조립체는 상기 미분 재조립 공정에서 도출된 상태로 사용될 수도 있고， 미분 재조립체를 건조， 분쇄 및 분급 공정을 거친 상태로 사용될 수도 있다. The polymer having a particle size of 150 to 850 urn is derived from the step of classifying the pulverized polymer according to the particle size, the range of the normal particle size range The powder reassembly, which corresponds to a polymer, refers to a reassembly which has been reassembled by the above-described method of fine powder having a particle diameter of less than 150 μα derived in the classification step. In this case, the fine powder reassembly may be used in a state derived from the fine powder reassembling process, or may be used in a state in which the fine powder reassembly is dried, pulverized and classified.
미분 재조립체를 건조， 분쇄 및 분급 공정을 거친 상태로 사용하는 경우에， 미분 재조립체의 건조， 분쇄 및 분급 공정은 상술한 함수겔상 중합체를 건조， 분쇄 및 분급하는 공정올 제한 없이 적용할 수 있다.  In the case where the fine powder reassembly is used in a drying, pulverizing and classification process, the drying, pulverizing and classification process of the fine powder reassembly can be applied without any limitation in the process of drying, pulverizing and classifying the hydrous gel polymer described above. .
또한， 상기 150 내지 850 의 입경을 갖는 중합체와 미분 재조립체는 약 6 : 4 내지 8 : 2 의 중량비로 흔합될 수 있다. 이때， 상기 흔합 비율에 특별한 제약은 없으나, 마분의 재조립체의 비율이 증가할수록 정상적인 입경 범위의 중합체만을 사용하는 경우와 비교하여 물성의 저하를 초래하기 때문에， 미분의 재조립체의 함량은 30 중량 % 이상을 초과하지 않는 것이 바람직하다.  In addition, the polymer having a particle size of 150 to 850 and the fine powder reassembly may be mixed at a weight ratio of about 6: 4 to 8: 2. At this time, there is no particular restriction on the mixing ratio, but as the ratio of the reassembly of the powder increases, the physical properties are reduced compared to the case of using only a polymer having a normal particle size range. It is preferable not to exceed the above.
그리고， 상기 표면 가교 단계는 입자 내부의 가교결합 밀도와 관련하여 고흡수성 고분자 입자 표면 근처의 가교결합 밀도를 증가시키는 단계이다. 일반적으로， 표면 가교제는 고흡수성 수지 입자의 표면에 도포된다. 따라서， 이 반웅은 고흡수성 수지 입자의 표면 상에서 일어나며， 이는 입자 내부에는 실질적으로 영향을 미치지 않으면서 입자의 표면 상에서의 가교 결합성은 개선시킨다. 따라서 표면 가교 결합된 고흡수성 수지 입자는 내부에서보다 표면 부근에서 더 높은 가교 결합도를 갖는다. 이때 상기 표면 가교제로는 중합체가 갖는 관능기와 반웅 가능한 화합물이라면 그 구성의 한정이 없다.  The surface crosslinking step is to increase the crosslinking density near the surface of the superabsorbent polymer particles in relation to the crosslinking density inside the particles. Generally, the surface crosslinking agent is applied to the surface of the super absorbent polymer particles. Thus, this reaction occurs on the surface of the superabsorbent resin particles, which improves the crosslinkability on the surface of the particles without substantially affecting the interior of the particles. The surface crosslinked superabsorbent resin particles thus have a higher degree of crosslinking in the vicinity of the surface than in the interior. In this case, the surface crosslinking agent is not limited as long as it is a compound capable of reacting with the functional group of the polymer.
바람직하게는 생성되는 고흡수성 수지의 특성을 향상시키기 위해, 상기 표면 가교제로 다가 알콜 화합물; 에폭시 화합물; 폴리아민 화합물; 할로에폭시 화합물; 할로에폭시 화합물의 축합 산물; 옥사졸린 화합물류; 모노-， 디- 또는 폴리옥사졸리디논 화합물; 환상 우레아 화합물; 다가 금속염; 및 알킬렌 카보네이트 화합물로 이루어진 군에서 선택되는 1 종 이상을 포함할 수 있다. 구체적으로， 다가 알콜 화합물의 예로는 모노- , 디-， 트리-， 테트라- 또는 폴리에틸렌 글리콜, 모노프로필렌 글리콜, 1，3-프로판디을， 디프로필렌 글리콜， 2，3，4-트리메틸 -1 , 3-펜탄디을， 폴리프로필렌 글리콜, 글리세를， 폴리글리세를， 2-부텐 -1 , 4-디올， 1，4-부탄디올， 1 , 3-부탄디을, 1 , 5-펜탄디을， 1 , 6-핵산디을， 및 1， 2-사이클로헥산디메탄을로 이루어진 군에서 선택되는 1 종 이상을 사용할 수 있다. Preferably, in order to improve the properties of the resulting super absorbent polymer, the surface crosslinking agent may be a polyhydric alcohol compound; Epoxy compounds; Polyamine compounds; Haloepoxy compound; Condensation products of haloepoxy compounds; Oxazoline compounds; Mono-, di- or polyoxazolidinone compounds; Cyclic urea compounds; Polyvalent metal salts; And it may include one or more selected from the group consisting of alkylene carbonate compounds. Specifically, examples of the polyhydric alcohol compound include mono-, di-, tri-, tetra- or polyethylene glycol, monopropylene glycol, 1,3-propanedi, dipropylene glycol, 2,3,4-trimethyl-1, 3 -Pentanedi, polypropylene glycol, glycerol, polyglycerol, 2-butene-1, 4-diol, 1,4-butanediol, 1, 3-butanedi, 1, 5-pentanedi, 1, 6-nucleic acid Di, and 1, 2-cyclohexane dimethane can be used 1 or more types chosen from the group which consists of.
또한， 에폭시 화합물로는 에틸렌 글리콜 디글리시딜 에테르 및 글리시돌 등을 사용할 수 있으며， 폴리아민 화합물류로는 에틸렌디아민， 디에틸렌트리아민， 트리에틸렌테트라아민， 테트라에틸렌펜타민， 펜타에틸렌핵사민, 폴리에틸렌이민 및 폴리아미드폴리아민로 이루어진 군에서 선택되는 1 종 이상을 사용할 수 있다.  Ethylene glycol diglycidyl ether and glycidol may be used as the epoxy compound, and polyamine compounds may be ethylene diamine, diethylene triamine, triethylene tetraamine, tetraethylenepentamine, or pentaethylene nucleoamine. , At least one selected from the group consisting of polyethyleneimine and polyamide polyamine can be used.
또, 할로에폭시 화합물로는 에피클로로히드린， 에피브로모히드린 및 α -메틸에피클로로히드린을 사용할 수 있다. 한편， 모노- , 디- 또는 폴리옥사졸리디논 화합물로는 예를 들어 2-옥사졸리디논 등을 사용할 수 있다.  Moreover, epichlorohydrin, epibromohydrin, and (alpha)-methyl epichlorohydrin can be used as a halo epoxy compound. On the other hand, 2-oxazolidinone etc. can be used as a mono-, di-, or a polyoxazolidinone compound.
그리고， 알킬렌 카보네이트 화합물로는 에틸렌 카보네이트 등을 사용할 수 았다.  As the alkylene carbonate compound, ethylene carbonate or the like may be used.
한편， 표면가교 후 조립자의 생성을 최소화하고， 표면가교 효율을 증가시키기 위해， 상기 표면 가교제 중에서 1 종 이상의 알킬렌 카보네이트 화합물을 포함하는 것이 바람직하며， 더욱 바람직하게는 에틸렌 카보네이트를 사용할 수 있다 .  On the other hand, in order to minimize the formation of coarse particles after the surface crosslinking and increase the surface crosslinking efficiency, it is preferable to include at least one alkylene carbonate compound in the surface crosslinking agent, and more preferably ethylene carbonate may be used.
상기 첨가되는 표면 가교제의 함량은 구체적으로 추가되는 표면 가교제의 종류나 반웅 조건에 따라 적절히 선택될 수 있지만， 통상 150 내지 850 im 의 입경을 갖는 중합체와 미분 재조립체 100 중량부에 대해， 약 0.001 내지 약 5 중량부， 바람직하게는 약 0.01 내지 약 3 중량부， 더욱 바람직하게는 약 0.05 내지 약 2 중량부를 사용할 수 있다.  The amount of the surface crosslinking agent to be added may be appropriately selected depending on the kind or reaction conditions of the surface crosslinking agent to be added, but it is usually about 0.001 to 100 parts by weight based on 100 parts by weight of the polymer having a particle diameter of 150 to 850 im About 5 parts by weight, preferably about 0.01 to about 3 parts by weight, more preferably about 0.05 to about 2 parts by weight can be used.
표면 가교제의 함량이 지나치게 적으면， 표면 가교 반웅이 거의 일어나지 않으며， 중합체 100 중량부에 대해， 5 중량부를 초과하는 경우， 과도한 표면 가교 반웅의 진행으로 인해 흡수능력 및 물성의 저하 현상이 발생할 수 있다. . 그리고， 상기 표면 가교하는 단계는 150°C 내지 300 °C의 온도에서 10 분 내지 100 분 동안 표면 가교 반응시킬 수 있다. 즉, 표면 가교제가 첨가된 150 내지 850 의 입경을 갖는 중합체와 미분 재조립체의 흔합물에 대해 가열시킴으로써 표면 가교 결합 반응이 이루어질 수 있으며， 이 때 건조가 함께 이루어질 수도 있다 . When the content of the surface crosslinking agent is too small, the surface crosslinking reaction hardly occurs, and when 100 parts by weight of the polymer is more than 5 parts by weight, excessive surface crosslinking reaction may result in deterioration of absorbing ability and physical properties. . . The surface crosslinking may be a surface crosslinking reaction for 10 minutes to 100 minutes at a temperature of 150 ° C to 300 ° C. That is, the surface crosslinking reaction may be performed by heating a mixture of a polymer having a particle size of 150 to 850 to which a surface crosslinking agent is added and the fine powder reassembly, and drying may be performed together.
표면 가교 반웅을 위한 승온 수단은 특별히 한정되지 않는다. 열매체를 공급하거나， 열원을 직접 공급하여 가열할 수 있다. 이때， 사용 가능한 열매체의 종류로는 스팀， 열풍， 뜨거운 기름과 같은 승온한 유체 등을 사용할 수 있으나， 본 발명이 이에 한정되는 것은 아니며, 또한 공급되는 열매체의 은도는 열매체의 수단， 승온 속도 및 승온 목표 온도를 고려하여 적절히 선택할 수 있다. 한편， 직접 공급되는 열원으로는 전기를 통한 가열， 가스를 통한 가열 방법을 들 수 있으나， 상술한 예에 본 발명이 한정되는 것은 아니다. 【발명의 효과】  The temperature raising means for surface crosslinking reaction is not specifically limited. It can be heated by supplying a heat medium or by directly supplying a heat source. In this case, as the type of heat medium that can be used, a heated fluid such as steam, hot air, or hot oil may be used. However, the present invention is not limited thereto, and the silver content of the heat medium to be supplied is a means of heating medium, a temperature rising rate, and a temperature increase. It may be appropriately selected in consideration of the target temperature. On the other hand, the heat source directly supplied may be a heating method through electricity, a gas heating method, the present invention is not limited to the above examples. 【Effects of the Invention】
본 발명의 고흡수성 수지의 제조 방법에 따르면， 미분 재조립체의 웅집강도를 증가시킴으로써 보수능 또는 가압 흡수능의 저하 없이 투과도가 향상된 고흡수성 수지를 제조할 수 있다. 【도면의 간단한 설명】  According to the manufacturing method of the super absorbent polymer of the present invention, the superabsorbent polymer having improved permeability can be prepared without increasing the water retention capacity or the pressurized absorbent capacity by increasing the foaming strength of the fine powder reassembly. [Brief Description of Drawings]
도 1 은 제조예 1 의 주사전자현미경 (Scanning Electron Mi croscope , SEM)사진이다.  1 is a scanning electron microscope (SEM) photograph of Preparation Example 1. FIG.
도 2 는 제조예 2 의 주사전자현미경 (Scannir g Electron Microscope , SEM)사진이다.  2 is a scanning electron microscope (Scannir g Electron Microscope, SEM) photograph of Preparation Example 2.
도 3 은 비교 제조예 3 의 주사전자현미경 (Scanning Electron 3 is a scanning electron microscope of Comparative Preparation Example 3 (Scanning Electron)
Mi croscope , SEM)사진이다. Mi croscope, SEM).
【발명을 실시하기 위한 구체적인 내용】 발명을 하기의 실시예에서 보다 상세하게 설명한다. 단， 하기의 실시예는 본 발명을 예시하는 것일 뿐, 본 발명의 내용이 하기의 실시예에 의하여 한정되는 것은 아니다. 제조예 및 비교 제조예: 미분 재조립체의 제조 방법 [Specific contents to carry out invention] The invention is explained in more detail in the following examples. However, the following examples are merely to illustrate the invention, but the content of the present invention is not limited by the following examples. Preparation Example and Comparative Preparation Example: Method of Preparing Fine Powder Reassembly
제조예 1  Preparation Example 1
150 이하의 미분 40g 을 회전식 믹서를 아용하여 mi x i ng 하면서 저온의 물 50g을 스프레이로 투입하여 재조립을 하였다., 함수된 재조립체를 180 °C 에서 30 분 동안 건조하여 함수량이 3% 이하인 건조된 미분 재조립체를 제조하였다. 분쇄 후 분급하여 입경이 150 내지 850 / 범위인 미분 재조립체를 수득하였다.  40 g of fine powder of 150 or less was re-assembled by spraying 50 g of cold water with a sprayer while using a rotary mixer. The reassembled water was dried at 180 ° C for 30 minutes, and the water content was 3% or less. Fine powder reassembly was prepared. Grinding followed by classification gave a fine powder reassembly having a particle diameter in the range of 150 to 850 /.
제조예 2  Preparation Example 2
150 !M 이하의 미분 40g 을 mi x ing 하면서 저온의 물 40g 을 스프레이로 투입한 것을 제외하고는 제조예 1 과 동일한 방법으로 미분 재조립체를 수득하였다.  A fine powder reassembled product was obtained in the same manner as in Production Example 1, except that 40 g of cold water was sprayed with mi 40 g of fine powder of 150! M or less.
제조예 3  Preparation Example 3
150 im 이하의 미분 . 40g 을 mi x i ng 하면서 저온의 물 30g 을 스프레이로 투입한 것을 제외하고는 제조예 1 과 동일한 방법으로 미분 재조립체를 수득하였다. 비교 제조예 1  Differential up to 150 im. A fine powder reassembled product was obtained in the same manner as in Preparation Example 1, except that 30 g of cold water was sprayed with 40 g of mi x ing. Comparative Production Example 1
150 im 이하의 미분 40g 을 mi x ing 하면서 고온의 물 50g 을 스프레이로 투입한 것을 제외하고는 제조예 1 과 동일한 방법으로 미분 재조립체를 수득하였다.  A fine powder reassembled product was obtained in the same manner as in Preparation Example 1, except that 50 g of hot water was sprayed while mixing 40 g of fine powder of 150 im or less.
비교 제조예 2  Comparative Production Example 2
150 im 이하의 미분 40g 을 mi xi ng 하면서 고온의 물 40g 을 스프레이로 투입한 것을 제외하고는 제조예 1 과 동일한 방법으로 미분 재조립체를 수득하였다.  A fine powder reassembled product was obtained in the same manner as in Preparation Example 1, except that 40 g of fine powder of 150 im or less was injected with mi xi ng and 40 g of hot water was sprayed.
비교 제조예 3 150 m 이하의 미분 40g 을 mixing 하면서 고온의 물 30g 스프레이로 투입한 것을 제외하고는 제조예 1 과 동일한 방법으로 口 재조립체를 수득하였다. Comparative Production Example 3 A 口 reassembled product was obtained in the same manner as in Preparation Example 1, except that 40 g of a powder of 150 m or less was added with a spray of hot water 30 g.
【표 1】 Table 1
Figure imgf000017_0001
실시예 및 비교예: 고흡수성 수지의 제조방법
Figure imgf000017_0001
Examples and Comparative Examples: Preparation of Super Absorbent Polymers
실시예 1  Example 1
아크릴산 (수용성 에틸렌계 불포화 단량체) 단량체 100g, 가성소다 (NaOH) 40g 및 물 137g 을 흔합하고， 상기 흔합물에 igacure 819(광증합 개시제) 0.008g, 소디움퍼설페이트 (열중합 개시제) 0.2g, 폴리에틸렌글리콜디아크릴레이트 (가교제) 0.5g 및 핵산다이을아크릴레이트 (가교제) 0.05g 를 포함하는 모노머 조성물을 준비하였다. 상기 모노머 조성물을 내부온도가 80°C인 챔버에서 10mV UV 램프 광원으로 자외선을 1 분간 조사하고, 추가로 2 분간 무광원 상태에서 중합 반웅을 진행하였다. 중합 반응 진행 후， meat chopper 를 이용하여 10瞧 이하의 입자로 절단하고， 열풍 건조기를 이용하여 180°C에서 30 분간 건조하였다. 이후 분쇄, 분급하여 입경이 150 내지 850 인 고흡수성 베이스 수지를 얻었다. 100 g of acrylic acid (water-soluble ethylenically unsaturated monomer) monomer, 40 g of caustic soda (NaOH) and 137 g of water are mixed, and 0.008 g of igacure 819 (photopolymerization initiator), 0.2 g of sodium persulfate (thermal polymerization initiator), polyethylene A monomer composition containing 0.5 g of glycol diacrylate (crosslinking agent) and 0.05 g of nucleic acid diacrylate (crosslinking agent) was prepared. The monomer composition was irradiated with ultraviolet light for 1 minute with a 10 mV UV lamp light source in a chamber having an internal temperature of 80 ° C., and polymerization reaction was performed in a non-light source state for 2 minutes. After the polymerization reaction was cut into particles of 10 kPa or less using a meat chopper, and dried at 180 ° C. for 30 minutes using a hot air dryer. Thereafter, the resultant was ground and classified to obtain a super absorbent base resin having a particle diameter of 150 to 850.
다음으로， 상기 150 내지 850 im 의 입경을 갖는 고흡수성 베이스 수지 70g과 제조예 1의 미분 재조립체 30g을 흔합한 후 에틸렌 카보네이트 0.4g, 물 3g, 옥살산 0.22g, DM30S 0.02g 을 투입하여 균일하게 흔합하고， 180°C에서 40 분 동안 표면가교를 진행하였다. 분쇄 후 시브 (sieve)를 이용하여 입경 크기가 150 내지 850 의 표면처리된 고흡수성 수지를 수득하였다. Next, 70 g of the superabsorbent base resin having a particle size of 150 to 850 im and 30 g of the fine powder reassembly of Preparation Example 1 were mixed, and then 0.4 g of ethylene carbonate, 3 g of water, 0.22 g of oxalic acid, and 0.02 g of DM30S were added uniformly. After mixing, the surface was crosslinked at 180 ° C. for 40 minutes. After crushing the sieve To obtain a surface-treated superabsorbent polymer having a particle size of 150 to 850.
실시예 2  Example 2
180 °C에서 60 분 동안 표면가교를 진행한 것을 제외하고는 실시예 1과 동일한 방법으로 고흡수성 수지를 수득하였다. 비교예 1 Superabsorbent polymer was obtained in the same manner as in Example 1, except that the surface crosslinking was performed at 180 ° C. for 60 minutes. Comparative Example 1
실시예 1 의 베이스 수지 70g 과 비교 제조예 1 의 미분 재조립체 30g 을 흔합하고 180°C에서 40 분 동안 표면가교를 진행한 것을 제외하고는 실시예 1과 동일한 방법으로 고흡수성 수지를 수득하였다. A super absorbent polymer was obtained in the same manner as in Example 1, except that 70 g of the base resin of Example 1 and 30 g of the fine powder reassembly of Comparative Example 1 were mixed and subjected to surface crosslinking at 180 ° C. for 40 minutes.
비교예 2  Comparative Example 2
실시예 1 의 베이스 수지 70g 과 비교 제조예 1 의 미분 재조립체 30g 을 흔합하고 180°C에서 60 분 동안 표면가교를 진행한 것을 제외하고는 실시예 1과 동일한 방법으로 고흡수성 수지를 수득하였다. A super absorbent polymer was obtained in the same manner as in Example 1, except that 70 g of the base resin of Example 1 and 30 g of the fine powder reassembly of Comparative Preparation Example 1 were mixed and subjected to surface crosslinking at 180 ° C. for 60 minutes.
비교예 3  Comparative Example 3
미분 재조립체를 흔합하지 않고， 실시예 1 의 베이스 수지 100g 을 이용하여 180°C에서 40 분 동안 표면가교를 진행한 것을 제와하고는 실시예 1과 동일한 방법으로 고흡수성 수지를 수득하였다. The superabsorbent polymer was obtained in the same manner as in Example 1, except that the surface recrosslinking was carried out at 180 ° C. for 40 minutes using 100 g of the base resin of Example 1 without mixing the fine powder reassembly.
비교예 4 ᅳ  Comparative Example 4
미분 재조립체를 흔합하지 않고， 실시예 1 의 베이스 수지 100g 을 이용하여 180°C에서 60 분 동안 표면가교를 진행한 것을 제외하고는 실시예 1과 동일한 방법으로 고흡수성 수지를 수득하였다. 시험예 1 : 미분 재조립체의 물성 평가 A superabsorbent polymer was obtained in the same manner as in Example 1, except that the fine powder reassembled was not mixed and surface crosslinking was performed at 180 ° C. for 60 minutes using 100 g of the base resin of Example 1. Test Example 1 Evaluation of Physical Properties of Fine Powder Reassembly
( 1) 입도 평가  (1) particle size evaluation
상기 제조예 및 비교 제조예에서 제조한 미분 재조립체의 입도는 EDANA 법 및 WSP 220.2 방법에 따라 측정하였다. 그 결과는 표 2 에 나타내었다. (2) 자유 팽창률 (FSR, Free Swel l Rate) 측정 상기 실시예 및 비교예에서 제조한 l .OOgOWl)의 고흡수성 수지 입자를 25 ml 의 제 1 유리 비커에 균일하게 분배하였다. 그리고， 20ml (=W2)의 0.9 중량 % 염화나트륨 용액을 제 2 유리 비커로 디스펜싱하고， 이 비커의 내용물을 제 1 유리 비커로 신속하게 첨가한 후 스톱워치를 눌렀다. 액체 표면에서 반사 소멸에 의해 확인되는 염용액의 마지막 방울을 흡수하자마자， 스톱워치를 정지하였다. 이 때， 표면에서 마지막 액체 방울의 소멸은 시간 t 로서 규정된다. 그리고， 자유 팽창률 (FSR)은 다음과 같은 식에 따라 계산하여 표 3에 기재하였다: The particle size of the fine powder reassembly prepared in Preparation Example and Comparative Preparation Example was measured according to EDANA method and WSP 220.2 method. The results are shown in Table 2. (2) Free Swel Rate (FSR) Measurement OOgOWl) superabsorbent resin particles prepared in the above Examples and Comparative Examples were uniformly distributed in 25 ml of the first glass beaker. 20 ml (= W2) of 0.9 wt% sodium chloride solution was then dispensed into a second glass beaker, and the contents of this beaker were quickly added to the first glass beaker and the stopwatch was pressed. The stopwatch was stopped as soon as the last drop of salt solution identified by the reflection disappearance at the liquid surface was absorbed. At this time, the disappearance of the last liquid drop at the surface is defined as time t. And the free expansion coefficient (FSR) is calculated according to the following formula and is shown in Table 3:
[식 1]  [Equation 1]
FSR(g/gs)=W2/(Wl*t )  FSR (g / gs) = W2 / (Wl * t)
(3) 무하중하 흡수배율 (CRC, Centr i fuge Retent ion Capaci ty) EDANA 법 WSP 241.2 에 따라 상기 제조예 및 비교 제조예의 고흡수성 수지에 대하여 무하중하 흡수배율에 의한 보수능을 측정하여 표 3 에 기재하였다. (3) Unloaded Absorption Ratio (CRC) Centrifugal Retent Ion Capacity (CRC) According to the EDANA method WSP 241.2, the water-retaining capacity by the unloaded absorption ratio was measured for the superabsorbent polymers of the above-described preparations and comparative preparations. Described.
즉， 실시예 및 비교예로 얻어진 수지 W(g) (약 O . lg)을 부직포제의 봉투에 균일하게 넣고 밀봉 (seal )한 후， 상온에서 0.9 질량 %의 생리 식염수에 침수시켰다. 30 분 후에 봉투를 원심 분리기를 이용하고 250G 로 3 분간 물기를 뺀 후에 봉투의 질량 W2(g)을 측정했다. 또 수지를 이용하지 않고 동알한 조작을 한 후에 그때의 질량 Wl(g)을 측정했다. 얻어진 각 질량을 이용하여 다음과 같은 식에 따라 CRC (g/g)를 산출하였다.  That is, the resin W (g) (about O. lg) obtained in Examples and Comparative Examples was uniformly sealed in a nonwoven fabric bag, and then immersed in 0.9% by mass of physiological saline at room temperature. After 30 minutes, the envelope was centrifuged and drained at 250 G for 3 minutes, and then the mass W2 (g) of the envelope was measured. Moreover, after carrying out the same operation without using resin, the mass W1 (g) at that time was measured. Using each mass obtained, CRC (g / g) was computed according to the following formula.
[식 2]  [Equation 2]
CRC(g/g) = { (W2(g) - Wl(g) )/ W(g) } - 1 (4) 수가용성분 (EC, R tractable content )  CRC (g / g) = {(W2 (g)-Wl (g)) / W (g)}-1 (4) Retractable content (EC)
EDANA법 WSP 270.2에 개시되어 있는 순서와 동일한 방법으로 수가용 성분을 측정하여 표 3 에 기재하였다. 본 발명에서 언급하고 있는 중화도는 수가용 성분 측정시에 계산되어지는 식에 의해 계산된 중화도 값이다. (5) 미분 재조립체의 주자전자현미경 (SEM) 이미지 도 1 내지 3은 각각 상기 제조예 1 내지 2 및 비교 제조예 3에 따른 미분 재조립체를 주사전자현미경 (Scanning Electron Mi croscope , SEM)으로 관찰한 사진이다. The water-soluble components were measured in the same manner as the procedure disclosed in the EDANA method WSP 270.2 and listed in Table 3. The neutralization degree referred to in the present invention is a neutralization value calculated by an equation calculated at the time of measuring the aqueous component. (5) Runner electron microscopy (SEM) images of fine powder reassembly 1 to 3 are photographs of the fine powder reassembles according to Preparation Examples 1 to 2 and Comparative Preparation Example 3, respectively, with a scanning electron microscope (SEM).
도 1 내지 3 을 참고하면， 제조예 1(도 1 )， 제조예 2(도 2)와 비교 제조예 3(도 3)을 비교할 때， 표면상태가 제조예 1， 2 가 더 매끄럽고 공극이 적어 보인다. 따라서， 저온의 물을 재조립 단계에서 사용한 제조예 1， 2 가 비교 제조예 3 에 비하여 공극이 적고， 재조립 미분의 강도가 더 높은 것을 알 수 있다. (6) 미분 재조립체의 파쇄강도 측정  Referring to Figures 1 to 3, when comparing the Preparation Example 1 (Fig. 1), Preparation Example 2 (Fig. 2) and Comparative Preparation Example 3 (Fig. 3), the surface conditions of the Preparation Examples 1, 2 are smoother and less voids see. Accordingly, it can be seen that Preparation Examples 1 and 2, in which low-temperature water was used in the reassembly step, have less voids and higher strength of the reassembled fine powder than Comparative Preparation Example 3. (6) Measurement of fracture strength of fine powder reassembly
Text Analyzer (TA)의 XT2plus 장비를 사용하여 고흡수성 수지 단일 입자를 직경 8 mm 의 실린더로 0.01 mm/s 의 속도로 정속 가압하여 걸리는 힘을 측정하였다. 장치가 내려가면서 고흡수성 수지가 버티는 힘이 점점 증가하며 일정 이상 되면 파쇄가 일어나는데， 이 때 입자가 견디는 최대 힘을 파쇄 강도 (kg 'Force)로 정의하고 10회 측정 후 정규 분포 곡선을 그려 좌우 5%를 배제한 뒤 평균을 구하였다. 그리고, 이 평균 값을 표 3 에 기재하였다.  XT2plus equipment from Text Analyzer (TA) was used to measure the force of the superabsorbent polymer single particles at a constant speed of 0.01 mm / s into a cylinder of 8 mm in diameter. As the device descends, the force of the superabsorbent polymer increases gradually, and when a certain amount is exceeded, crushing occurs. At this time, the maximum force that the particles endure is defined as crushing strength (kg 'Force), and after 10 measurements, a normal distribution curve is drawn. The average was obtained after excluding%. And this average value is described in Table 3.
【표 2] [Table 2]
Figure imgf000020_0001
【표 3】
Figure imgf000020_0001
Table 3
Figure imgf000021_0001
시험예 2: 고흡수성 수지의 물성 평가
Figure imgf000021_0001
Test Example 2: Evaluation of Physical Properties of Super Absorbent Polymer
( 1) 가압 흡수량 (Absorbing under Pressure , AUP) 측정  (1) Absorbing under Pressure (AUP) measurement
실시예 및 비교예의 고흡수성 수지에 대하여 EDANA 법 MP 242.2 의 방법에 따라 가압 흡수량을 측정하여 표 4에 기재하였다.  About the superabsorbent polymer of an Example and a comparative example, the pressure absorption amount was measured according to the method of EDANA method MP242.2, and it is shown in Table 4.
간단한 가압 흡수능 (AUP : Absorbency under Pressure)의 측정 방법은 다음과 같다.  A simple method of measuring Absorbency Under Pressure (AUP) is as follows.
즉， 내경 60隱 의 플라스틱의 원통 바닥에 스테인레스제 400 mesh 철망을 장착시켰다. 상온， 습도 5OT의 조건하에서 철망상에 흡수성 수지 0.90g을 균일하게 살포하고， 그 위에 4.83 kPa(0.7 ps i )의 하증을 균일하게 더 부여할 수 있는 피스톤 (pi ston)은， 외경이 60 誦 보다 약간 작고 원통의 내벽과 틈이 없고， 상하의 움직임이 방해받지 않게하였다. 이때 상기 장치의 중량 Wa(g)을 측정하였다.  In other words, a stainless steel 400 mesh wire mesh was mounted on the bottom of a 60-mm inner plastic cylinder. The piston, which can evenly spray 0.90 g of the absorbent resin onto the wire mesh under the condition of room temperature and humidity of 5 OT, and further give a lowering of 4.83 kPa (0.7 ps i) on it, has an outer diameter of 60 kPa. It is slightly smaller and has no gaps with the inner wall of the cylinder, and the up and down movement is not disturbed. At this time, the weight Wa (g) of the apparatus was measured.
직경 150 腿의 페트로 접시의 내측에 직경 90瞧로 두께 5薩의 유리 필터를 두고, 0.90 중량 >의 염화 나트륨으로 구성된 생리 식염수를 유리 필터의 윗면과 동일 레벨이 되도록 하였다. 그 위에 직경 90誦 의 여과지 1 장을 실었다. 여과지 위에 상기 측정장치를 싣고, 액을 하중하에서 1 시간 동안 흡수하였다. 1 시간 후 측정 장치를 들어을리고, 그 중량 Wb(g)을 측정하였다. A glass filter having a diameter of 90 mm and a thickness of 5 mm was placed inside a petri dish having a diameter of 150 mm 3, and the physiological saline consisting of 0.90 weight> sodium chloride was set to the same level as the upper surface of the glass filter. One sheet of filter paper having a diameter of 90 mm was loaded thereon. Put the measuring device on the filter paper and load the liquid Absorbed for 1 hour. After 1 hour, the measuring device was lifted and the weight Wb (g) was measured.
그리고 Wa , Wb로부터 다음 식에 따라 가압 흡수능을 산출하였다. And the pressure absorption capacity was computed from Wa and Wb by following Formula.
[식 3] [Equation 3]
AUP (g/g) = [Wb(g) - Wa(g) ] / 흡수 수지의 질량 (g)  AUP (g / g) = [Wb (g)-Wa (g)] / mass of absorbent resin (g)
(2) 무하중하 흡수배율 (CRC , Centr i fuge Retent ion Capaci ty) 상기 미분 재조립체의 물성 평가 방법 중 (3) 무하중하 흡수배율 측정 방법과 동일한 방법으로 실시예 및 비교예의 고흡수성 수지의 무하중하 흡수배율을 측'정하여 표 4에 기재하였다. (2) Unloaded Absorption Ratio (CRC) Centrifugal Retent ion Capaci ty (3) Among the methods for evaluating the physical properties of the fine powder reassembly, (3) the unabsorbed superabsorbent polymers of the Examples and Comparative Examples by the same method as the measurement method of the unloaded absorption ratio Heavy the absorption magnification side, are shown in Table 4. appointed.
(3) 용액 투과도 (SFC , permeabi l i ty) 측정 (3) Measurement of solution permeability (SFC, permeabi l i ty)
SFC (생리 식염수 흐름 유도성)은 2.07kPa 하중 하에서의 흡수성 수지에 대한 0.69 중량 % 염화나트륨 수용액의 통액성을 의미하며， 미국 특허 제 5669894 호에 기재된 SFC 시험 방법에 따라 측정하여 표 4 에 기재하였다.  SFC (physiological saline flow inducible) refers to the permeability of 0.69% by weight aqueous sodium chloride solution to an absorbent resin under a 2.07 kPa load and is measured in accordance with the SFC test method described in US Pat. No. 5669894 and listed in Table 4.
(4) 투과도 측정 (4) transmittance measurement
문헌 (Buchholz , F .L and Graham , A .T.， "Modern Superabsorbent Polymer Technology" , John Wi ley&Sons( 1998) , page 161)에 기술된 방법에 따라 0.9% 염수용액을 사용하여 0.3psi 하중 하에서 측정하였다. 샘플 0.2g을 취하여 준비된 실린더에 투입하고， 여기에 50g의 0.9% 염수 용액을 투입하고 30 분간 방치하였다. 이후， 0.3psi 무게의 추를 0.9% 염수 용액을 흡수한 샘플에 올려놓고 1 분간 방치하였다. 이후 실린더 아래에 위치한 스탑콕 (stopcock)을 열어 0.9% 염수 용액이 실린더에 미리 표시된 상한선에서부터 하한선을 통과하는 시간을 측정하였다. 모든 측정은 24士 1°C의 온도 및 50 ± 10%의 상대습도 하에서 실시하였다. 상기 상한선에서부터 하한선을 통과하는 시간을 각각의 샘플에 대해서와 고흡수성 수지의 투입 없이 측정하여 하기 식에 따라 투과도를 계산하여 표 4에 기재하였다. [식 4] Measured under a 0.3 psi load using 0.9% saline solution according to the method described in Buchholz, F.L and Graham, A.T., "Modern Superabsorbent Polymer Technology", John Wiley & Sons (1998), page 161 It was. 0.2 g of sample was taken and put into a prepared cylinder, and 50 g of 0.9% saline solution was added thereto and left for 30 minutes. Thereafter, a 0.3 psi weight was placed on a sample absorbed with 0.9% saline solution and allowed to stand for 1 minute. The stopcock located under the cylinder was then opened to measure the time for the 0.9% saline solution to pass through the lower limit from the upper limit previously marked on the cylinder. All measurements were carried out at a temperature of 24 ° C. 1 ° C. and a relative humidity of 50 ± 10%. The time passing from the upper limit to the lower limit was measured for each sample and without the addition of a super absorbent polymer, and the transmittance was calculated according to the following formula and is shown in Table 4. [Equation 4]
투과도 (sec)= 시간 (샘플) -시간 (고흡수성 수지의 투입 없이 측정)  Permeability (sec) = time (sample)-time (measured without addition of super absorbent polymer)
【표 4】 Table 4
Figure imgf000023_0001
상기 표 4 을 참고하면， 실시예 1 내지 2 와 같이 미분 재조립체를 제조하는 과정에서 저온의 물을 사용하는 경우, 웅집강도가 우수한 재조립체를 제조할 수 있고, 이를 150 내지 850 m 의 입경을 갖는 중합체와 흔합 및 표면가교 하여 제조한 고흡수성 수지는 비교예와 유사한 흡수능력 (CRC , AUP)에서 우수한 투과도를 나타냄을 확인할 수 있다.
Figure imgf000023_0001
Referring to Table 4, in the case of using low temperature water in the process of manufacturing the fine powder reassembly as in Examples 1 to 2, it is possible to produce a reassembly having excellent follicular strength, which has a particle size of 150 to 850 m It can be seen that the superabsorbent polymer prepared by mixing and surface crosslinking with the polymer having excellent permeability in the absorption capacity (CRC, AUP) similar to the comparative example.
또한， 실시예 1 내지 2 는 미분 재조립체의 조립강도가 증가하게 되어 이송 및 분쇄， 표면가교 과정에서 입도가 하향되는 양이 줄어들게 되어 기공이 유지되는 면에서 유리하기 때문에 높은 용액 투과도 (SFC) 값을 갖는다.  In addition, Examples 1 to 2 have a high solution permeability (SFC) value because the assembly strength of the fine powder reassembly is increased to decrease the amount of particle size down during transport, grinding, and surface crosslinking, thereby maintaining pores. Has

Claims

【특허청구범위】 [Patent Claims]
【청구항 1]  [Claim 1]
수용성 에틸렌계 불포화 단량체 및 중합개시제를 포함하는 모노머 조성물에 열중합 또는 광중합을 진행하여 함수겔상 중합체를 형성하는 단계;  Thermally polymerizing or photopolymerizing the monomer composition including a water-soluble ethylenically unsaturated monomer and a polymerization initiator to form a hydrogel polymer;
상기 함수겔상 중합체를 건조하는 단계;  Drying the hydrogel polymer;
건조된 중합체를 분쇄하는 단계;  Pulverizing the dried polymer;
상기 분쇄된 중합체를 입경에 따라 150 미만의 입경을 갖는 미분과， 150 내지 850 의 입경을 갖는 중합체로 분급하는 단계;  Classifying the pulverized polymer into fine powder having a particle size of less than 150, and a polymer having a particle size of 150 to 850 according to the particle size;
상기 150 'ΙΜ 이하의 입경을 갖는 미분 100 중량부에 대하여 5 내지5 to 5 parts by weight of fine powder having a particle diameter of 150 ' ΙΜ or less
30°C의 물을 50 내지 200중량부 흔합하여 습윤시켜 재조립하는 단계 ; 및 상기 150 내지 850 iM 의 입경을 갖는 중합체와 미분 재조립체를 흔합하여 표면 가교하는 단계;를 포함하는 고흡수성 수지의 제조 방법 . 50-200 parts by weight of water at 30 ° C mixed and reassembled by wet; And surface-crosslinking a polymer having a particle diameter of 150 to 850 iM and a fine powder reassembly.
【청구항 2】 [Claim 2]
제 1항에 있어서，  The method of claim 1,
상기 150 내지 850 im 의 입경을 갖는 중합체와 미분 재조립체는 6 : 4 내지 8 : 2의 중량비로 흔합되는 고흡수성 수지의 제조 방법 .  The polymer having a particle diameter of 150 to 850 im and the fine powder reassembly are mixed in a weight ratio of 6: 4 to 8: 2: 2.
【청구항 3】 [Claim 3]
제 1항에 있어서，  The method of claim 1,
상기 표면 가교하는 단계는 150 내지 850 m 의 입경을 갖는 중합체와 미분 재조립체 100 중량부에 대해 0.001 내지 5 중량부의 표면 가교제를 사용하는 고흡수성 수지의 제조 방법 .  The step of surface crosslinking is a method for producing a super absorbent polymer using 0.001 to 5 parts by weight of a surface crosslinking agent based on 100 parts by weight of a polymer having a particle diameter of 150 to 850 m and fine powder reassembly.
【청구항 4】 . 【Claim 4】 .
제 3항에 있어서，  The method of claim 3,
상기 표면 가교제는 다가 알콜 화합물; 에폭시 화합물; 폴리아민 화합물; 할로에폭시 화합물; 할로에폭시 화합물의 축합 산물; 옥사졸린 화합물류; 모노- , 디- 또는 폴리옥사졸리디논 화합물; 환상 우레아 화합물; 다가 금속염; 및 알킬렌 카보네이트 화합물로 이루어진 군에서 선택되는 1 종 이상을 포함하는 고흡수성 수지의 제조 방법. The surface crosslinking agent may be a polyhydric alcohol compound; Epoxy compounds; Polyamine compounds; Haloepoxy compound; Condensation products of haloepoxy compounds; Oxazoline compounds; Mono-, di- or polyoxazolidinone compounds; Cyclic urea compounds; Polyvalent metal salts; And an alkylene carbonate compound. A method for producing a superabsorbent polymer comprising at least one member selected from the group consisting of alkylene carbonate compounds.
【청구항 5】 [Claim 5]
제 1항에 있어서，  The method of claim 1,
상기 표면 가교하는 단계는 150°C 내지 300°C의 온도에서 10 분 내지 100분 동안 표면 가교 반웅시키는 고흡수성 수지와 제조 방법 . The surface crosslinking step is a super absorbent polymer and a method for producing a surface crosslinking reaction for 10 to 100 minutes at a temperature of 150 ° C to 300 ° C.
[청구항 6】 [Claim 6]
제 1항에 있어서，  The method of claim 1,
상기 5 내지 30°C의 물은 미스트 또는 스프레이 장치를 이용하여 상기 미분에 흔합하여 습윤시키는 고흡수성 수지의 제조 방법. The water of 5 to 30 ° C is mixed with the fine powder using a mist or a spray device to wet the superabsorbent resin manufacturing method.
【청구항 7】 [Claim 7]
제 1항에 있어서,  The method of claim 1,
상기 재조립 단계에서， 미분은 함수율이 40 내지 . 60 중량 ¾>인 상태에서 재조립하는 고흡수성 수지의 제조 방법.  In the reassembling step, the derivative has a water content of 40 to. A method for producing a super absorbent polymer, which is reassembled in a state of 60 weight ¾>.
【청구항 8】 [Claim 8]
제 1항에 있어서，  The method of claim 1,
상기 함수겔상 중합체의 함수율은 40 내지 60 중량%인 고흡수성 수지의 제조 방법 .  The water content of the water-containing gel polymer is 40 to 60% by weight of the method for producing a super absorbent polymer.
【청구항 9】 [Claim 9]
제 1항에 있어서，  The method of claim 1,
상기 건조된 중합체의 함수율은 0. 1 내지 10 중량 %인 고흡수성 수지의 제조 방법 .  The moisture content of the dried polymer is 0.1 to 10% by weight of the method for producing a super absorbent polymer.
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