WO2023105737A1 - Ink set for ink-jet recording, ink-jet recording method, and ink-jet recording device - Google Patents

Ink set for ink-jet recording, ink-jet recording method, and ink-jet recording device Download PDF

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Publication number
WO2023105737A1
WO2023105737A1 PCT/JP2021/045458 JP2021045458W WO2023105737A1 WO 2023105737 A1 WO2023105737 A1 WO 2023105737A1 JP 2021045458 W JP2021045458 W JP 2021045458W WO 2023105737 A1 WO2023105737 A1 WO 2023105737A1
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Prior art keywords
ink
inkjet recording
treatment liquid
inkjet
ink set
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PCT/JP2021/045458
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French (fr)
Japanese (ja)
Inventor
歩 上井
正幸 牛久
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コニカミノルタ株式会社
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Priority to PCT/JP2021/045458 priority Critical patent/WO2023105737A1/en
Publication of WO2023105737A1 publication Critical patent/WO2023105737A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/17—Ink jet characterised by ink handling
    • B41J2/18—Ink recirculation systems
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D11/00—Inks
    • C09D11/30—Inkjet printing inks
    • C09D11/32—Inkjet printing inks characterised by colouring agents
    • C09D11/322—Pigment inks
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D11/00—Inks
    • C09D11/54—Inks based on two liquids, one liquid being the ink, the other liquid being a reaction solution, a fixer or a treatment solution for the ink

Definitions

  • the present invention relates to an ink set for inkjet recording, an inkjet recording method, and an inkjet recording apparatus. More specifically, the present invention relates to an ink set for ink jet recording, which has good ink ejection stability and improved image quality of recorded matter.
  • the inkjet recording (also called “printing”) method is a recording method in which small droplets of ink are ejected from an inkjet head and landed on the surface of a recording medium such as paper. With this method, it is possible to print high-resolution and high-quality images at high speed with a relatively inexpensive device.
  • inkjet printing especially when water-based ink is used, when a character or image pattern is printed on the surface of a recording medium, the liquid component permeates the recording medium and then dries, fixing the ink.
  • plain paper, special paper, high-quality paper, or recycled paper with high ink absorption as the recording medium, the ink can be easily fixed and a high-quality image can be provided.
  • a recording medium with low or no absorbency such as , art paper, lightly coated paper, or film
  • the ink droplets do not easily penetrate into the recording medium, so drying does not occur due to penetration. Bleeding occurred between the droplets, and the image quality was impaired.
  • the ink In order to improve the image quality of the recorded matter (printed matter), it is preferable that the ink has high viscosity on the surface of the recording medium and is quickly fixed. On the other hand, when the ink is ejected from the inkjet head, if the viscosity of the ink is too high, it becomes difficult to stably eject the required amount to the required location. Therefore, it is preferable that the ink has good ejection stability and is quickly fixed on the surface of the recording medium.
  • Patent Literature 1 discloses a technique for an aqueous inkjet ink in which the ratio of the viscosity when the shearing force is strongly controlled and the viscosity when the shearing force is weakly controlled is a certain value or more. Since the ink has relatively high so-called thixotropic properties, the viscosity decreases when subjected to a shearing force, but the viscosity is relatively high when the ink remains stationary without being subjected to a shearing force.
  • the ink can be fixed immediately on the surface of the recording medium, but when it is ejected from the inkjet head, it is necessary to adjust the viscosity to the optimum level by applying a shearing force, etc., and precise control of the circulation flow rate, etc. is required. was necessary.
  • the treatment liquid includes one that forms a layer (ink-receiving layer) that absorbs the liquid components of the ink and improves drying properties, and one that aggregates the solid components to intentionally increase the viscosity of the ink.
  • a layer ink aggregation layer
  • two types are known that form a layer (ink aggregation layer) that prevents ink bleeding and color unevenness between ink droplets.
  • a treatment liquid containing an aggregating agent is applied to the surface of the recording medium, and then the ink is applied, and the treatment liquid and the ink are combined (mixed) in a liquid state to obtain the ink.
  • a method (hereinafter, also referred to as “wet-on-wet method”) is known for quickly aggregating a coloring material inside and quickly fixing a mixture of a treatment liquid and an ink.
  • the treatment liquid is preferably applied using a blade-like member or a sponge-like member while rotating the roller.
  • the application amount can be adjusted by controlling, the treatment liquid is applied uniformly over a certain range. Therefore, it is difficult to finely control the application amount of the treatment liquid in correspondence with the application amount of the ink. Further, no study has been made on a method of applying the treatment liquid by an inkjet method.
  • the processing liquid contains resin particles and a thickener (hydrophobic-modified water-soluble urethane resin) to increase the viscosity of the processing liquid, thereby improving the recording properties with low or no absorbency.
  • a thickener hydrophobic-modified water-soluble urethane resin
  • the treatment liquid has a relatively high viscosity, when applied by an inkjet method, good ejection stability cannot be obtained. It was found to be defective.
  • Cited Document 4 discloses a technique for improving optical density and marker resistance by including an associative thickener in the treatment liquid (reaction liquid).
  • the present invention has been made in view of the above-mentioned problems and circumstances, and the problem to be solved is an ink set for inkjet recording, an inkjet recording method, and an inkjet recording method, in which the ejection stability of the ink is good and the image quality of the recorded matter is improved. It is to provide a recording device.
  • the present inventors have investigated the causes of the above problems and found that, in an inkjet recording ink set containing an ink and a treatment liquid, the thickener contained in the ink causes excessive aggregation of the coloring material.
  • the present inventors have found that the presence of the inhibiting function provides good ejection stability of the ink and improves the image quality of the recorded matter, leading to the present invention. That is, the above problems related to the present invention are solved by the following means.
  • An inkjet recording ink set comprising an ink and a treatment liquid,
  • the ink contains a thickener, a coloring material, water and an organic solvent
  • the treatment liquid contains a flocculant, water and an organic solvent
  • the ink is composition A
  • a composition B is obtained by removing the thickening agent from the ink
  • a composition C is obtained by mixing the composition A and the treatment liquid
  • the composition D is obtained by mixing the composition B and the treatment liquid
  • V C and V D satisfy the following relational expressions (1) and (2): Formula (1): V A >V B
  • Items 1 to 10 wherein the composition obtained by mixing the ink and the treatment liquid has a viscosity VC of 15 mPa ⁇ s or more at a shear rate of 2 [1/s] at 25°C.
  • An inkjet recording method using an inkjet recording ink set Using the inkjet recording ink set according to any one of items 1 to 11, An inkjet recording method, wherein the ink and the treatment liquid are combined with each other on the surface of a recording medium.
  • Item 15 The inkjet recording method according to any one of Items 12 to 14, wherein the ink set for inkjet recording is discharged from an inkjet recording apparatus having a circulation mechanism.
  • Item 16 The inkjet recording method of Item 15, wherein the circulation mechanism is bidirectional circulation.
  • An inkjet recording apparatus using an inkjet recording ink set Using the inkjet recording ink set according to any one of items 1 to 11,
  • the inkjet recording device has the inkjet head for the ink and the inkjet head for the treatment liquid, The inkjet head for ink and the inkjet head for treatment liquid are mounted on the same carriage, or An inkjet recording apparatus, wherein the inkjet head for ink and the inkjet head for treatment liquid are mounted on separate carriages, and the carriages are adjacent to each other without a drying mechanism interposed therebetween.
  • a wet-on-wet method in order to sufficiently agglomerate the coloring material in the ink.
  • the coalescence (mixing) of the liquid ink and the treatment liquid on the surface of the recording medium increases the chances of contact between the coloring material in the ink and the aggregating agent in the treatment liquid, so that aggregation proceeds sufficiently.
  • the particle size of aggregates composed of a flocculant and a coloring material becomes too large, i.e., over-aggregation tends to occur, and smoothness is reduced, resulting in a decrease in glossiness.
  • the problem was the deterioration of image quality. Therefore, in the wet-on-wet method, it is necessary to adjust the progress of aggregation to the extent that image quality does not deteriorate.
  • the present inventors conducted extensive studies and found that there exists a compound that has a function of inhibiting excessive aggregation of the coloring material. was found to improve.
  • a compound (thickener) that has the property of increasing the viscosity of the ink when contained in the ink, it is possible to adjust the viscosity of the ink to a viscosity that provides good ejection stability. have understood.
  • Schematic diagram showing an inkjet recording device Carriage bottom view
  • the ink set for inkjet recording of the present invention is an ink set for inkjet recording containing an ink and a treatment liquid, wherein the ink contains a thickener, a coloring material, water and an organic solvent, and the treatment liquid aggregates agent, water and an organic solvent, and the thickener has a function of inhibiting overaggregation of the colorant.
  • This feature is a technical feature common to or corresponding to the following embodiments.
  • the ink is a composition A
  • the ink excluding the thickener is a composition B
  • the viscosities V C and V D at a shear rate of 2 [1/s] at 25 ° C. of the compositions C and D are expressed by the following relational expression (1 ) and (2) are preferably satisfied.
  • Formula (2) V C ⁇ V D
  • the composition A has a viscosity VA of 15 mPa ⁇ s or less at a shear rate of 1000 [1/s] at 25°C.
  • the ratios R C and R D of the number of coarse particles of 5 ⁇ m or more in the compositions C and D satisfy the following relational expression (3).
  • the content of the thickening agent is within the range of 5 to 100% by mass with respect to the total mass of the coloring material.
  • the thixotropic index at 25°C of the ink is preferably in the range of 0.85 to 1.0.
  • the thickener has at least a hydrophilic portion and a hydrophobic portion in the same particle.
  • the content of the organic solvent in the ink is in the range of 5 to 25% by mass with respect to the total mass of the ink.
  • the aggregating agent is preferably a polyvalent metal salt, a cationic polymer or an organic acid, and more preferably the polyvalent metal salt contains at least calcium salt or magnesium salt.
  • the composition obtained by mixing the ink and the treatment liquid has a viscosity V C at a shear rate of 2 [1/s] at 25° C. of 15 mPa ⁇ s or more.
  • the ink jet recording method of the present invention is characterized in that the ink set for ink jet recording of the present invention is used, and the ink and the treatment liquid are united with each other on the surface of the recording medium.
  • the ink set is ejected from the staggered inkjet heads.
  • the ink set for inkjet recording is preferably ejected from an inkjet recording apparatus having a circulation mechanism, and more preferably, the circulation mechanism is bidirectional circulation.
  • the inkjet recording apparatus of the present invention uses the inkjet recording ink set of the present invention, the inkjet recording apparatus has the inkjet head for the ink and the inkjet head for the treatment liquid, and the inkjet head for the ink and the treatment liquid.
  • the inkjet head for the treatment liquid is mounted on the same carriage, or the inkjet head for the ink and the inkjet head for the treatment liquid are mounted on separate carriages, and the carriages are adjacent to each other without a drying mechanism interposed therebetween. It is characterized by
  • the ink set for inkjet recording of the present invention is an ink set for inkjet recording containing an ink and a treatment liquid, wherein the ink contains a thickener, a coloring material, water and an organic solvent, and the treatment liquid aggregates agent, water and an organic solvent, and the thickener has a function of inhibiting overaggregation of the colorant.
  • the ink according to the present invention is a water-based ink containing water.
  • Water-based inks can have a relatively low VOC (volatile organic compound) content compared to solvent inks, and are therefore preferable because they can reduce the burden on the environment.
  • VOC volatile organic compound
  • the treatment liquid Due to the reaction with the aggregating agent in the ink, the coloring material in the ink agglomerates and the viscosity of the mixture of the ink and treatment liquid increases. It is possible to suppress bleeding and color unevenness between ink droplets.
  • overaggregation Excessive aggregation of the coloring material in the ink is called "overaggregation", and by suppressing overaggregation, good image quality can be obtained in the printed matter.
  • the thickener contained for the purpose of obtaining good ejection stability further has a function of inhibiting overaggregation of the coloring material, thereby suppressing overaggregation of the coloring material and improving image quality.
  • the effect is remarkable in the wet-on-wet method in which overaggregation tends to occur.
  • the presence or absence of excessive aggregation can be determined by viscosity.
  • the viscosity of the mixture of the ink according to the present invention (including the thickener) and the treatment liquid (mixed liquid) is such that the ink excluding the thickener is mixed with the treatment liquid. If the viscosity is lower than or equal to that of the other (mixed liquid), it can be determined that excessive aggregation is suppressed. A method for measuring the viscosity will be described later.
  • the ink according to the present invention contains a thickener, a coloring material, water and an organic solvent, and is characterized in that the thickening agent has a function of inhibiting excessive aggregation of the coloring material.
  • the ink according to the present invention can adjust the viscosity of the ink and obtain good ejection stability. Also, the organic solvent content in the ink can be reduced. Furthermore, since the thickener has a function of inhibiting overaggregation of the coloring material, overaggregation of the coloring material is suppressed, and image quality can be improved.
  • Thickening agent refers to a substance that increases the viscosity of a liquid when added, and in the present invention, further refers to a substance that has the function of inhibiting overaggregation of a coloring material.
  • the method and conditions for measuring viscosity are not particularly limited.
  • Whether or not the thickener has a function of inhibiting overaggregation of the coloring material is determined, for example, by comparing the ink (including the thickener) according to the present invention and the ink excluding the thickener. are mixed with the treatment liquid, and the viscosity of the mixture and the ratio of the number of coarse particles are compared. A method for comparing the viscosity and the ratio of the number of coarse particles will be described later in detail.
  • the ink according to the present invention behaves as if it were a physically cross-linked macromolecule due to intermolecular interactions caused by containing the thickening agent. It is thought that the viscosity of the system increases due to Since the coloring material is retained in the macromolecules, excessive aggregation of the coloring material can be suppressed even when mixed with a treatment liquid containing an aggregating agent. However, since the physical cross-linked structure of macromolecules is formed by intermolecular interactions, the coloring material is not completely retained, and some coloring materials can move freely, and the flocculant and It is possible to aggregate by reaction. Therefore, the coloring material can be appropriately aggregated.
  • any compound that has the function of increasing the viscosity of the liquid and inhibiting overaggregation of the coloring material is particularly limited. can be used without
  • the thickening agent according to the present invention may be an inorganic compound or an organic compound. From the viewpoint of interaction with the coloring material, the thickening agent is preferably an organic compound, and at least It is more preferable to have a hydrophilic part and a hydrophobic part in the same particle.
  • Particles here refer to aggregates formed by aggregation of molecules, and the types of molecules may all be the same or different. In addition, in the assembly, the molecules may form chemical bonds with each other. Further, “having at least a hydrophilic part and a hydrophobic part in the same particle” means that at least the same aggregate has a hydrophilic part and a hydrophobic part, and is composed only of a hydrophobic part without a hydrophilic part. molecules may be present in the aggregate.
  • an emulsifier surfactant
  • an aggregate may be formed only by molecules having a hydrophilic portion and a hydrophobic portion in the same molecule.
  • water-insoluble resin fine particles or water-soluble resins described below are preferable.
  • the content of the thickening agent is preferably in the range of 0.1 to 5% by weight with respect to the total weight of the ink. By being within the above range, good ejection stability of the ink can be obtained. Also, the content of the thickening agent is preferably in the range of 5 to 100% by mass with respect to the coloring material. By being within the above range, excessive aggregation can be sufficiently suppressed.
  • inorganic compounds include inorganic compounds such as silica (SiO 2 ), alumina, and titania, and clay minerals such as bentonite and montmorillonite, among which silica powder, hydrophobically treated silica powder, or a mixture thereof. is preferred.
  • fine silica powder pulverized by a dry method for example, Aerosil 300, manufactured by Nippon Aerosil Co., Ltd.
  • fine powder obtained by modifying the above fine silica powder with trimethyldisilazane for example, Aerosil RX300, manufactured by Nippon Aerosil Co., Ltd.
  • a fine powder obtained by modifying the silica fine powder with polydimethylsiloxane for example, Aerosil RY300, manufactured by Nippon Aerosil Co., Ltd.
  • Laponite manufactured by BYK-Chemie
  • silicate a synthetic layered silicate made from naturally occurring inorganic mineral sources
  • the average particle size of the inorganic compound is preferably within the range of 5-50 ⁇ m, more preferably within the range of 5-12 ⁇ m.
  • Water-insoluble resin microparticles As the organic compound, the following water-insoluble resin fine particles can be used.
  • the water-insoluble resin fine particles can be dispersed in an aqueous medium by having at least a hydrophilic portion and a hydrophobic portion in the same particle.
  • resin fine particle dispersion The resin fine particles described below are water-insoluble resin fine particles, and a water-insoluble resin fine particle dispersion containing the water-insoluble resin fine particles exhibits solubility or affinity for ink.
  • the "water-insoluble resin fine particles” are originally water-insoluble, but have a form in which the resin is dispersed in an aqueous medium as micro fine particles.
  • hydrophilic portion into a water-insoluble resin (hydrophobic portion) (forced emulsification using an emulsifier or the like, or introducing a hydrophilic functional group into the molecule), the hydrophilic portion and the hydrophobic and can be dispersed in an aqueous medium.
  • a structure having a hydrophilic portion and a hydrophobic portion in the same molecule, that is, a hydrophilic functional group is introduced into the molecule to form a stable aqueous dispersion by itself without using an emulsifier or a dispersion stabilizer. It is preferably a water-insoluble resin that can self-emulsify to form.
  • the term “water-insoluble” means that when the resin is dried at 105° C. for 2 hours and then dissolved in 100 g of water at 25° C., the dissolved amount is 10 g or less, preferably 5 g or less, and further Preferably, it refers to a resin weighing 1 g or less.
  • the dissolved amount is the dissolved amount when the salt-forming group of the resin is 100% neutralized with acetic acid or sodium hydroxide, depending on the type.
  • the fine resin particles are preferably acrylic resin fine particles, urethane resin fine particles, polyester resin fine particles, or composite resin fine particles of urethane resin and acrylic resin.
  • the dispersion becomes unstable and the fine particles are adsorbed and aggregated to each other, resulting in an increase in the particle size of the fine particles.
  • the average particle size (Z average particle size) of the fine resin particles is preferably 1000 nm or more.
  • the average particle size (Z-average particle size) of fine particles can be measured by the following procedure using a particle size measuring device and a dynamic light scattering method.
  • a slurry containing resin fine particles is diluted with ion-exchanged water so that the resin fine particles are 0.1% by mass, the diluted slurry is irradiated with a laser beam, and the scattered light intensity scattered from the resin fine particles changes over time in microseconds.
  • Measure in The Z-average particle size of the resin fine particles is obtained by applying the scattering intensity distribution caused by the detected resin fine particles to a normal distribution and using the cumulant analysis method.
  • the particle size measuring device include Zetasizer Nano ZS manufactured by Spectris.
  • the particle size measuring device is equipped with data analysis software, and the Z-average particle size can be calculated by automatically analyzing the measurement data with the data analysis software.
  • a resin may be added in addition to the thickener from the viewpoint of improving fixability to the recording medium.
  • the fixing resin it is preferable to use fine resin particles having an average particle size (Z-average particle size) of less than 1000 nm at the time of aggregation.
  • polyester resin, urethane resin, acrylic resin, or composite resin particles of urethane resin and acrylic resin are preferably anionic or nonionic.
  • the resin fine particles preferably contain an acid structure (hydrophilic portion).
  • an acid structure hydrophilic portion
  • the acid structure may be present in the side chain of the resin, or may be present at the end.
  • the acid structure is not necessarily required, and the acid structure may or may not be present. good too.
  • a part or all of the acid structure is preferably neutralized.
  • the neutralizing agent that neutralizes the acid structure are preferably organic amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, N-methyldiethanolamine, and triethanolamine.
  • the glass transition point (Tg) of the fine resin particles is preferably in the range of -30 to 100°C.
  • the glass transition point (Tg) is determined from the endothermic peak when the temperature is raised in the temperature range of ⁇ 30 to 200° C. at a temperature elevation rate of 10° C./min using a DSC (differential scanning calorimeter). It can be identified by reading the transition temperature Tg.
  • polyester resin A polyester resin having a polyester skeleton as water-insoluble resin fine particles can be obtained by using a polyhydric alcohol component and a polycarboxylic acid component such as a polycarboxylic acid, a polycarboxylic anhydride, or a polycarboxylic acid ester. can.
  • a dihydric alcohol specifically an alkylene glycol having 2 to 36 carbon atoms (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1, 4-butylene glycol, 1,6-hexanediol, etc.), alkylene ether glycols having 4 to 36 carbon atoms (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polybutylene glycol, etc.), carbon Alicyclic diols having numbers 6 to 36 (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.), alkylene oxides having 2 to 4 carbon atoms in the alicyclic diols (ethylene oxide (hereinafter referred to as EO), propylene oxide (hereinafter abbreviated as PO), butylene oxide (hereinafter abbreviated as BO)) adduct (addition mole number range of 1
  • polycarboxylic acid components include divalent carboxylic acids (dicarboxylic acids), specifically alkanedicarboxylic acids having 4 to 36 carbon atoms (succinic acid, apidic acid, sebacic acid, etc.), alkenylsuccinic acids ( dodecenyl succinic acid, etc.), alicyclic dicarboxylic acids having 4 to 36 carbon atoms (dimer acid (dimerized linoleic acid), etc.), alkenedicarboxylic acids having 4 to 36 carbon atoms (maleic acid, fumaric acid, citraconic acid, mesaconic acid, etc.), aromatic dicarboxylic acids having 8 to 36 carbon atoms (phthalic acid, isophthalic acid, terephthalic acid or derivatives thereof, naphthalenedicarboxylic acid, etc.). These may be used alone or in combination of two or more.
  • the number average molecular weight of the polyester resin is preferably within the range of 1,000 to 50,000, more preferably within the range of 2,000 to 20,000.
  • polyester resin commercially available products may be used.
  • urethane resin A urethane resin having a hydrophilic group can be used as the water-insoluble resin fine particles.
  • Urethane resin is an aqueous dispersion of self-emulsifying urethane that has a water-soluble functional group in its molecule, or a forced emulsifying urethane water that is emulsified under strong mechanical shearing force using a surfactant in combination.
  • a dispersion is preferred.
  • the urethane resin in the aqueous dispersion can be obtained by reacting a polyol with an organic polyisocyanate and a hydrophilic group-containing compound.
  • polyester polyols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2- and 1,3-propylene glycol, neopentyl glycol, 1,3- and 1,4-butanediol, 3-methylpentanediol, Low-molecular-weight polyols such as hexamethylene glycol, 1,8-octanediol, 2-methyl-1,3-propanediol, bisphenol A, hydrogenated bisphenol A, trimethylolpropane, cyclohexanedimethanol; succinic acid, glutaric acid, adipine acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, tetrahydrofuranic acid, endomethinetetrahydrofuranic acid, condensates with polyvalent carboxylic acids such as hexahydrophthalic acid, and the like.
  • Low-molecular-weight polyols such as
  • polyether polyols examples include polyethylene glycol, polypropylene glycol, polyethylene polytetramethylene glycol, polypropylene polytetramethylene glycol, and polytetramethylene glycol.
  • polycarbonate polyols can be obtained by reacting carbonic acid derivatives such as diphenyl carbonate, dimethyl carbonate or phosgene with diols.
  • diols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2- and 1,3-propylene glycol, neopentyl glycol, 1,3- and 1,4-butanediol, 3-methylpentanediol, hexamethylene glycol, 1,8-octanediol, 2-methyl-1,3-propanediol, bisphenol A, hydrogenated bisphenol A, trimethylolpropane, cyclohexanedimethanol and the like.
  • organic polyisocyanates examples include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymeric MDI, xylylene diisocyanate (XDI), and tetramethylxylylene diisocyanate.
  • aromatic isocyanates such as (TMXDI); aliphatic isocyanates such as hexamethylene diisocyanate (HMDI); be done. These may be used alone or in combination of two or more.
  • a urethane resin can be obtained by a known method.
  • a urethane prepolymer can be obtained by mixing the polyol, organic polyisocyanate, and hydrophilic group-containing compound and reacting them at 30 to 130° C. for 30 minutes to 50 hours.
  • the urethane prepolymer becomes a urethane resin with hydrophilic groups by extending it with a chain extender and polymerizing it.
  • the chain extender is preferably water and/or an amine compound. By using water or an amine compound as a chain extender, the isocyanate-terminated prepolymer can be efficiently extended by reacting with free isocyanate in a short period of time.
  • amine compounds include aliphatic polyamines such as ethylenediamine and triethylenediamine; aromatic polyamines such as metaxylenediamine and toluylenediamine; and polyhydrazino compounds such as hydrazine and adipic acid dihydrazide.
  • the amine compound may contain, together with the polyamine, a monovalent amine such as dibutylamine, methyl ethyl ketoxime, or the like as a reaction terminator, to the extent that polymerization is not greatly hindered.
  • a solvent that is inert with isocyanate and capable of dissolving the urethane prepolymer may be used.
  • these solvents include dioxane, methyl ethyl ketone, dimethylformamide, tetrahydrofuran, N-methyl-2-pyrrolidone, toluene, propylene glycol monomethyl ether acetate, and the like.
  • These hydrophilic organic solvents used in the reaction step are preferably finally removed.
  • amine catalysts e.g., triethylamine, N-ethylmorpholine, triethyldiamine, etc.
  • tin-based catalysts e.g., dibutyltin dilaurate, dioctyltin dilaurate, octylic acid
  • Tin, etc. titanium-based catalysts (eg, tetrabutyl titanate, etc.) may be added.
  • the number average molecular weight of the urethane resin is preferably increased as much as possible by introducing a branched structure or an internal crosslinked structure, and is preferably from 50,000 to 1,000,000. Within the above range, the urethane resin becomes difficult to dissolve in a solvent, and a coating film excellent in weather resistance and water resistance can be obtained.
  • the number average molecular weight (Mn) is a value measured by gel permeation chromatography (GPC). Solvent: tetrahydrofuran (THF), column temperature: 40° C.) can be determined from a calibration curve prepared from polystyrene standard samples.
  • urethane resins such as WBR-016U (manufactured by Taisei Fine Chemical Co., Ltd.), Superflex (registered trademark) 620, 650, 500M, E-2000 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). , Permaline (registered trademark) UC-20 (manufactured by Sanyo Chemical Industries, Ltd.), Parasurf UP-22 (manufactured by Ohara Palladium Chemical Co., Ltd.), and the like.
  • WBR-016U manufactured by Taisei Fine Chemical Co., Ltd.
  • Superflex registered trademark
  • E-2000 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
  • Permaline registered trademark
  • UC-20 manufactured by Sanyo Chemical Industries, Ltd.
  • Parasurf UP-22 manufactured by Ohara Palladium Chemical Co., Ltd.
  • the acrylic resin can be obtained by using a copolymer with an acrylic acid ester component, a methacrylic acid ester component, a styrene component, or the like.
  • acrylic acid ester components and methacrylic acid ester components include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, blue (meth) acrylate, and (meth) acrylic acid-2- Hydroxyethyl, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, (meth)acrylate ) benzyl acrylate, 2-hydroxybutyl (meth)acrylate, benzyl (meth)acrylate, glycidyl (meth)acrylate, (meth)acrylic acid,
  • styrene components include styrene, 4-methylstyrene, 4-hydroxystyrene, 4-acetoxystyrene, 4-acetylstyrene and styrenesulfonic acid. These components may be used alone or in combination of two or more.
  • the number average molecular weight (Mn) of the acrylic resin is preferably 1,000 to 50,000, more preferably 2,000 to 20,000.
  • Mn number average molecular weight
  • the number average molecular weight (Mw) is a value measured by gel permeation chromatography (GPC).
  • Solvent: tetrahydrofuran (THF), column temperature: 40° C.) can be determined from a calibration curve prepared from polystyrene standard samples.
  • acrylic resin a commercially available product may be used. Fine Chemical Co., Ltd.), 2682, 2680, 2684, 2685, 2687 (manufactured by Nissin Kagaku Kogyo Co., Ltd.).
  • the fine resin particles may be fine composite resin particles, and are preferably fine composite resin particles obtained by emulsifying an acrylic resin with a urethane resin. That is, it is preferable that the fine composite resin particles have an inner layer made of an acrylic resin and a surface layer made of a urethane resin.
  • the urethane resin exists at the interface between the acrylic resin as the water-insoluble resin fine particles and the water as the continuous phase, and functions as a water-insoluble resin fine particle layer different from the resin that protects the water-insoluble resin fine particles.
  • composite resin fine particles obtained by emulsifying acrylic resin with urethane resin in this way, unlike using acrylic resin alone, it is possible to suppress deterioration in compatibility with urethane resin and pigment flocculant.
  • the physical properties of the image (coating film) can be improved, and the stability of the ink can also be improved, compared to emulsifying and mixing the acrylic resin and the urethane resin respectively.
  • the mass ratio (U/A) between the urethane resin (U) and the acrylic resin (A) is in the range of 40/60 to 95/5.
  • the mass ratio (U/A) between the urethane resin (U) and the acrylic resin (A) is preferably in the range of 40/60 to 80/20.
  • the total resin content of the acrylic resin and the urethane resin in the composite resin fine particles is not particularly limited, but is preferably 5.0% by mass or more relative to the total mass of the composite resin fine particles. It is more preferably within the range of 0.0 to 70.0% by mass. Within the above range, good fixability between the recording medium and the ink can be obtained.
  • a surfactant that acts as an emulsifier can be used together with the urethane resin.
  • an emulsifier By adding an emulsifier, the storage stability of the fine composite resin particles can be improved.
  • An anionic surfactant or a nonionic surfactant can be used as an emulsifier, and both are more preferably used in the present invention.
  • the content of the emulsifier (surfactant) is preferably in the range of 1.0 to 20.0% by mass with respect to the total mass of the total resin including the acrylic resin and the urethane resin. By being within the above range, water resistance and solvent resistance can be improved.
  • the content mass ratio (X/Y) between the anionic surfactant (X) and the nonionic surfactant (Y) is preferably within the range of 100/0 to 50/50. By being within the above range, the emulsifiability and the storage stability of the ink can be further improved.
  • anionic surfactants include alkyl sulfates, polyoxyethylene alkyl ether sulfates, sulfosuccinates, alpha olefin sulfonates, N-acyl amino acid salts, carboxylates, phosphate esters, and the like. Among them, sulfosuccinate or alpha olefin sulfonate is preferred.
  • the salt type include, but are not particularly limited to, metal salts such as sodium salts, potassium salts and magnesium salts, and triethanolamine salts.
  • nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkylamine ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, and the like. . Among them, polyoxyethylene alkyl ethers or polyoxyethylene alkylphenyl ethers are preferable.
  • the average particle size of the fine resin particles is preferably 1000 nm or more when used as a thickening agent. Further, from the viewpoint of improving the fixability to the recording medium, when the fine resin particles are used as a fixing resin separately from the thickening agent, the average particle size is preferably in the range of 10 to 500 nm, more preferably 10 to 300 nm. more preferably within the range of 10 to 200 nm. As described above, the average particle size can be measured by a commercially available particle size measuring instrument using a dynamic light scattering method, an electrophoresis method, or the like. The particle size range can be measured with high accuracy. When the fine resin particles are used from the viewpoint of improving fixability, the acid structure is not necessarily required, and the acid structure may or may not be present.
  • polyester resin Pesresin A-110F, A-520, A-613D, A-615GE, A-640, A-645GH, A-647GEX (manufactured by Takamatsu Oil Co., Ltd.), Vylonal (registered trademark) MD-1200, 1480, 2000 ( Above, manufactured by Toyobo), Elitel (registered trademark) KA-5034, KA-5071S, KA-1449, KA-0134, KA-3556, KA-6137, KZA-6034, KT-8803, KT-8701, KT- 9204, KT-8904, KT-0507, KT-9511 (manufactured by Unitika Ltd.)
  • NeoRez registered trademark
  • R-967 R-600, R-9671
  • W-6061 W-5661
  • WS-4000 manufactured by Mitsui Chemicals, Inc.
  • Evafanol registered trademark
  • HA-560 manufactured by Nicca Chemical Co., Ltd.
  • Water-soluble resin As the organic compound, the following water-soluble resins can be used.
  • a water-soluble resin can be dispersed in an aqueous medium by having a hydrophilic portion and a hydrophobic portion in the same molecule.
  • water-soluble resins examples include polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, sodium polyacrylate, hydroxycellulose, carboxymethylcellulose, and polyethylene glycol. These may be used alone or in combination of two or more.
  • water-soluble resin such as Joncryl (registered trademark) JDX-6500 (manufactured by BASF). Copolymer resins described in JP-A-2011-94082 may also be used.
  • thickener As the thickener according to the present invention, commonly used thickeners other than those mentioned above can be used, and examples thereof include associative thickeners. Commercially available products such as BYK (registered trademark)-425 (manufactured by BYK-Chemie) can be used as the associative thickener.
  • resins that are generally used as pigment dispersants can also be used as the thickener according to the present invention.
  • a commercial product may be used as the pigment dispersant, and examples thereof include Disperbyk 190 and 193 (manufactured by BYK-Chemie).
  • the ink according to the present invention can form an image on the surface of a recording medium by containing a coloring material.
  • the coloring material is not particularly limited as long as it can be colored, and includes dyes and pigments. Pigments are preferred from the viewpoint of forming images on recording media with low or no absorption.
  • pigments include anionic dispersed pigments, such as self-dispersing pigments having anionic groups on the surface, pigments dispersed with an anionic polymer dispersant, and pigments dispersed by coating the surface with an anionic resin. It is preferable to use a pigment or the like.
  • the anionic dispersed pigment is not particularly limited, and known ones can be used. Examples thereof include inorganic pigments such as titanium oxide, and organic pigments such as insoluble pigments and lake pigments.
  • the term "lake pigment” refers to a pigment that is made insoluble by precipitating a water-soluble dye with a lake agent (precipitant).
  • Titanium oxide has three crystal forms: anatase, rutile, and brookite.
  • General-purpose forms can be roughly divided into anatase and rutile. Although it is not particularly limited, it is preferably a rutile type having a high refractive index and high hiding power.
  • titanium oxide commercially available products can be used, such as TR series (trade name, manufactured by Fuji Titanium Industry Co., Ltd.), JR series (trade name, manufactured by Tayca), and Typaque (registered trademark) (trade name, manufactured by Ishihara Sangyo Co., Ltd.). ) and the like.
  • insoluble pigments include, but are not limited to, azo, azomethine, methine, diphenylmethane, triphenylmethane, quinacridone, anthraquinone, perylene, indigo, quinophthalone, isoindolinone, isoindoline, azine, oxazine, thiazine, dioxazine, and thiazole. , phthalocyanines, diketopyrrolopyrroles and the like.
  • organic pigments preferably used in the present invention include the following.
  • pigments for magenta or red for example, C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I. I. Pigment Red 7, C.I. I. Pigment Red 15, C.I. I. Pigment Red 16, C.I. I. Pigment Red 48:1, C.I. I. Pigment Red 53:1, C.I. I. Pigment Red 57:1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 123, C.I. I. Pigment Red 139, C.I. I. Pigment Red 144, C.I. I. Pigment Red 149, C.I. I.
  • Pigment Red 166 C.I. I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I. Pigment Red 202, C.I. I. Pigment Red 222, C.I. I. Pigment Violet 19 and the like.
  • pigments for orange or yellow for example, C.I. I. Pigment Orange 31, C.I. I. Pigment Orange 43, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I. I. Pigment Yellow 15:3, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 74, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 128, C.I. I. Pigment Yellow 94, C.I. I. Pigment Yellow 138, C.I. I. Pigment Yellow 155 and the like. In particular, C.I. I. Pigment Yellow 155 is preferred.
  • pigments for green or cyan for example, C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15:2, C.I. I. Pigment Blue 15:3, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 60, C.I. I. Pigment Green 7 and the like.
  • black pigments for example, C.I. I. Pigment Black 1, C.I. I. Pigment Black 6, C.I. I. Pigment Black 7 and the like.
  • the pigment dispersant used to disperse the pigment is not particularly limited, but is preferably a polymeric dispersant having an anionic group, and further preferably has a molecular weight within the range of 5000 to 200000.
  • polymeric dispersants examples include 2 selected from styrene, styrene derivatives, vinylnaphthalene derivatives, acrylic acid, acrylic acid derivatives, maleic acid, maleic acid derivatives, itaconic acid, itaconic acid derivatives, fumaric acid, and fumaric acid derivatives.
  • Block copolymers, random copolymers and salts thereof, polyoxyalkylenes, polyoxyalkylene alkyl ethers, etc., having structures derived from more than one kind of monomers are included.
  • the polymer dispersant preferably has an acryloyl group and is preferably added after being neutralized with a neutralizing base.
  • the neutralizing base is not particularly limited, but is preferably an organic base such as ammonia, monoethanolamine, diethanolamine, triethanolamine, morpholine and the like.
  • titanium oxide when used as the pigment, it is preferable to disperse the titanium oxide with a polymer dispersant having an acryloyl group.
  • the content of the polymeric dispersant in the ink is preferably in the range of 10 to 100% by mass, more preferably in the range of 10 to 40% by mass, relative to the total mass of the pigment.
  • a so-called capsule pigment in which the pigment is coated with the polymer dispersant may be used.
  • a method for coating the pigment with the polymer dispersant known methods can be used. and a method of coating while polymerizing.
  • Particularly preferred methods include the following methods.
  • a water-insoluble resin is dissolved in an organic solvent such as methyl ethyl ketone, and the acidic groups in the resin are partially or completely neutralized with a base.
  • a pigment and deionized water are added to disperse the pigment.
  • the organic solvent is removed, water is added as necessary, and a pigment dispersion is prepared.
  • the average particle size of the pigment in the dispersed state in the ink is preferably 50 nm or more and less than 300 nm. Within the above range, the dispersion stability of the pigment can be improved, and the storage stability of the ink can be improved.
  • the particle size of the pigment can be determined by a commercially available particle size measuring instrument using a dynamic light scattering method, an electrophoresis method, etc., but the measurement by the dynamic light scattering method is simple and can be measured with high accuracy.
  • the pigment can be dispersed with a dispersing machine together with a dispersant and other additives required according to the purpose.
  • the disperser a known one can be used, and examples include ball mills, sand mills, line mills, high-pressure homogenizers, and the like. Among them, it is preferable to disperse the pigment by a sand mill because the particle size distribution becomes sharp.
  • the material of the beads used for sand mill dispersion is not particularly limited, but zirconia or zircon is preferable from the viewpoint of preventing the generation of bead fragments and contamination with ionic components. Also, the bead diameter is preferably within the range of 0.3 to 3 mm.
  • the content of the pigment in the ink is not particularly limited, but it is preferably in the range of 7 to 18% by mass for titanium oxide and 0.5 to 7% by mass for the organic pigment relative to the total mass of the ink. % is preferred.
  • the ink according to the invention contains water.
  • water-based ink By using water-based ink, the content of organic solvents such as VOCs (volatile organic compounds) can be reduced compared to solvent ink.
  • Water is not particularly limited, and may be ion-exchanged water, distilled water, or pure water.
  • the water content in the ink is preferably in the range of 40 to 90% by weight with respect to the total weight of the ink.
  • the ink according to the present invention can improve the wettability of the ink and the moisture retaining property of the ink on the recording medium.
  • an organic solvent is used also for the purpose of thickening, but it is desirable to suppress the VOC content to 30% by mass or less from the viewpoint of reducing the burden on the environment and drying property.
  • the content of the organic solvent can be reduced by containing the thickener, and the drying property of the ink is improved.
  • the content of the organic solvent in the ink is not particularly limited, but is preferably within the range of 5 to 25% by mass with respect to the total mass of the ink. When the amount is 5% by mass or more, it is possible to suppress ink clogging and ink bubbling in head nozzles.
  • the organic solvent is preferably a water-soluble organic solvent such as alcohols, polyhydric alcohols, amines, amides, glycol ethers, and 1,2-alkanediols having 4 or more carbon atoms. etc.
  • Alcohols include, for example, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, t-butanol, 3-methoxy-1-butanol, 3-methoxy -3-methylbutanol, 1-octanol, 2-octanol, n-nonyl alcohol, tridecyl alcohol, n-undecyl alcohol, stearyl alcohol, oleyl alcohol, benzyl alcohol and the like.
  • polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol having 5 or more ethylene oxide groups, propylene glycol, dipropylene glycol, tripropylene glycol, and the number of propylene oxide groups. are 4 or more, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol, and the like.
  • amines include ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine, pentamethyldiethylenetriamine, tetramethylpropylenediamine, and the like.
  • amides include formamide, N,N-dimethylformamide, N,N-dimethylacetamide and the like.
  • glycol ethers examples include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, and tripropylene glycol monomethyl. ether and the like.
  • 1,2-alkanediols having 4 or more carbon atoms examples include 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, and 1,2-heptanediol. .
  • the organic solvent is preferably a polyhydric alcohol, especially ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol.
  • ethylene glycol diethylene glycol
  • triethylene glycol triethylene glycol
  • tetraethylene glycol propylene glycol
  • propylene glycol dipropylene glycol
  • tripropylene glycol preferably ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol.
  • These organic solvents may be used alone or in combination of two or more.
  • the ink according to the invention may further contain a resin.
  • a resin By containing a resin, fixability to a recording medium can be improved.
  • the fixation resin that enhances the fixability is not particularly limited, and examples thereof include vinyl chloride resins, (meth)acrylic resins, urethane resins, polyether resins, and polyester resins.
  • the water-insoluble resin fine particles described above may be contained as a fixing resin.
  • the average particle diameter of the fine resin particles is preferably in the range of 10 to 500 nm, more preferably in the range of 10 to 300 nm, even more preferably in the range of 10 to 200 nm.
  • the resin content in the ink is preferably in the range of 2 to 15% by mass with respect to the total mass of the ink.
  • the ink according to the present invention may contain various known additives according to other purposes such as ejection stability, compatibility with print heads and ink cartridges, storage stability, and image storage stability.
  • Additives include, for example, surfactants. By adding a surfactant, it is possible to improve the ejection stability of the ink and to control the spread (dot diameter) of the ink droplets that have landed on the recording medium.
  • the surfactant is not particularly limited, but when an anionic compound is included in the constituents of the ink, the ionicity of the surfactant may be anionic, nonionic (also referred to as "nonionic"), or amphoteric. and the amphoteric ionic surfactant is preferably a betaine type.
  • the anionic surfactant contains an alkaline component
  • the fine resin particles contained as the fixing resin tend to agglomerate and the fixability decreases, so the surfactant is preferably nonionic.
  • Surfactants include fluorine-based or silicone-based surfactants with high static surface tension lowering ability, anionic surfactants such as dioctyl sulfosuccinate with high dynamic surface tension lowering ability, relatively Nonionic surfactants such as low-molecular-weight polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, acetylene glycols, Pluronic (registered trademark) type surfactants, and sorbitan derivatives are preferred.
  • a surfactant having a high static surface tension lowering ability and a surfactant having a high dynamic surface tension lowering ability may be used in combination.
  • the content of the surfactant in the ink is not particularly limited, but is preferably within the range of 0.1 to 5.0% by mass with respect to the total mass of the ink.
  • various known additives such as polysaccharides, viscosity modifiers, resistivity modifiers, film-forming agents, ultraviolet absorbers, antioxidants, etc. agents, anti-fading agents, anti-mold agents, anti-rust agents, etc. can be used by appropriately selecting them. No. 74193, No. 57-87988, No. 62-261476, etc. ultraviolet absorbers, JP-A-57-74192, No. 57-87989, No. 60-72785, No.
  • JP-A-1-95091 anti-fading agents described in JP-A-1-95091, JP-A-3-13376, JP-A-59-42993, JP-A-59-52689, JP-A-62-280069, Fluorescent whitening agents described in JP-A-61-242871, JP-A-4-219266 and the like.
  • the viscosity of the ink according to the present invention at a shear rate of 1000 [1/s] at 25° C. is preferably 15 mPa ⁇ s (15 cP) or less, and 5 to 10 mPa ⁇ s. is preferably within the range of The viscosity at a shear rate of 1000 [1/s] at 25° C. can be measured using a rotational rheometer such as MCR-102 manufactured by Anton Paar in the same manner as the apparent viscosity ⁇ a below.
  • the ink according to the present invention preferably has relatively low thixotropy, and preferably has a thixotropic index at 25° C. within the range of 0.85 to 1.0.
  • Thixotropy refers to the property that the viscosity gradually decreases when subjected to shear stress and the viscosity gradually increases when standing still.
  • relatively low thixotropy refers to the It means that the thixotropic index is relatively close to 1.0.
  • the thixotropic index n in the viscosity equation can be calculated by the following method.
  • the treatment liquid according to the present invention is characterized by containing a coagulant, water and an organic solvent.
  • a coagulant e.g., water, water and an organic solvent.
  • the aggregating agent can aggregate the coloring material in the ink and improve the image quality of the recorded matter when used in combination with the ink. It may be liquid.
  • pre-treatment liquid refers to a treatment liquid that is applied to the surface of the recording medium before or at the same time as the application of ink to the surface of the recording medium
  • post-treatment liquid refers to the application of ink to the surface of the recording medium. It refers to a treatment liquid that is applied to the surface of the recording medium after the treatment.
  • the treatment liquid according to the present invention can aggregate the coloring material in the ink, and can improve the image quality of the recorded matter.
  • the aggregating agent is not particularly limited as long as it can aggregate the coloring material, but since the coloring material is usually an anionic component, examples thereof include metal salts, cationic compounds, acids, and the like.
  • the flocculants may be used singly or in combination of two or more.
  • the polyvalent metal salt can aggregate anionic components such as the coloring material in the ink by salting out.
  • polyvalent metal salts salts of metals having a valence of two or more can be used.
  • the type of metal (cation ) that constitutes the polyvalent metal salt is not particularly limited . , Cr 3+ , Y 3+ and other trivalent metal ions, and Zr 4+ and other tetravalent metal ions. From the viewpoint of water solubility, Ca 2+ , Mg 2+ , Zn 2+ or Al 3+ is preferable, and Ca 2+ or Mg 2+ is more preferable.
  • the type of anion that constitutes the polyvalent metal salt is not particularly limited, and may be an inorganic ion or an organic ion.
  • inorganic ions include carbonate ions, sulfate ions, nitrate ions, phosphate ions, chloride ions, and hydroxide ions.
  • organic ions include organic ions such as borate ions and carboxylate ions. acid ions.
  • polyvalent metal salts include calcium carbonate such as heavy calcium carbonate and light calcium carbonate, calcium nitrate, calcium chloride, calcium sulfate, magnesium sulfate, calcium hydroxide, magnesium chloride, magnesium carbonate, barium sulfate, barium chloride, zinc carbonate, zinc sulfide, aluminum silicate, calcium silicate, magnesium silicate, copper nitrate, calcium acetate, magnesium acetate, aluminum acetate and the like. These may be used singly or in combination of two or more.
  • magnesium sulfate, calcium nitrate, or calcium chloride is preferable from the viewpoints of having good water solubility and reducing traces left by the treatment liquid, that is, from the viewpoint of inconspicuous traces.
  • these metal salts may have water of hydration in the raw material form.
  • metal salts other than polyvalent metal salts include monovalent metal salts such as sodium salts and potassium salts, such as sodium sulfate and potassium sulfate.
  • the content of the metal salt is preferably 5% by mass or less, more preferably in the range of 0.1 to 3% by mass, more preferably 0.5 to 1.0% by mass, based on the total mass of the treatment liquid. It is more preferable to be within the mass % range. Within the above range, the anionic components such as the coloring material in the ink can be effectively aggregated, so that both image quality and hot water resistance can be achieved.
  • the metal salt content can be measured by a known method such as ICP emission spectrometry.
  • the applied amount of the metal salt is preferably within the range of 0.1 to 20 g/m 2 , and the applied amount of the treatment liquid is adjusted so as to fall within the above range. is preferred.
  • cationic polymers examples include cationic urethane-based resins, cationic olefin-based resins, and cationic amine-based resins.
  • cationic urethane resin commercially available products can be used, for example, Hydran (registered trademark) CP-7010, CP-7020, CP-7030, CP-7040, CP-7050, CP-7060, CP- 7610 (trade name, manufactured by Dainippon Ink and Chemicals), Superflex (registered trademark) 600, 610, 620, 630, 640, 650 (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), urethane emulsion WBR-2120C, WBR -2122C (trade name, manufactured by Taisei Fine Chemical Co., Ltd.) or the like can be used.
  • Hydran registered trademark
  • CP-7010 CP-7010
  • CP-7020 CP-7030, CP-7040, CP-7050, CP-7060
  • CP- 7610 trade name, manufactured by Dainippon Ink and Chemicals
  • Superflex registered trademark
  • the cationic olefin-based resin is a resin having an olefin such as ethylene, propylene, or the like in its structural skeleton, and a known one can be appropriately selected and used. Moreover, the cationic olefin resin may be in an emulsion state dispersed in a solvent containing water, an organic solvent, or the like. As the cationic olefin resin, commercially available products can be used, such as Arrowbase (registered trademark) CB-1200 and CD-1200 (trade name, manufactured by Unitika Ltd.).
  • any one having an amino group in its structure can be used, and a known one can be appropriately selected and used.
  • examples thereof include polyamine resins having amino groups in the main skeleton of the resin, polyamide resins having amide groups in the main skeleton of the resin, and polyallylamine resins having allyl groups in the main skeleton of the resin.
  • cationic polyamine resin a commercially available product can be used. mPa s), aqueous solution with a solid concentration of 50% by mass), Unisense KHE104L (trade name, manufactured by Senka Co., Ltd., dimethylamine/epichlorohydrin resin, pH of 1% aqueous solution of about 7.0, viscosity 1 to 10 (mPa s) , an aqueous solution having a solid concentration of 20% by mass), and the like.
  • Unisense KHE104L trade name, manufactured by Senka Co., Ltd., dimethylamine/epichlorohydrin resin, pH of 1% aqueous solution of about 7.0, viscosity 1 to 10 (mPa s) , an aqueous solution having a solid concentration of 20% by mass
  • FL-14 (trade name, manufactured by SNF), Arafix (registered trademark) 100, 251S, 255, 255LOX (trade name, manufactured by Arakawa Chemical Co., Ltd.), DK-6810, 6853, 6885; WS-4010, 4011 , 4020, 4024, 4027, 4030 (trade name, manufactured by Seiko PMC), Papiogen (registered trademark) P-105 (trade name, manufactured by Senka), Sumilaze Resin 650 (30), 675A, 6615, SLX-1 (trade name, manufactured by Taoka Chemical Co., Ltd.), Catiomaster (registered trademark) PD-1, 7, 30, A, PDT-2, PE-10, PE-30, DT-EH, EPA-SK01, TMHMDA-E (trade name, manufactured by Yokkaichi Gosei Co., Ltd.), Jetfix 36N, 38A, and 5052 (trade name, manufactured by Satoda Kako Co., Ltd.).
  • polyallylamine resins include polyallylamine hydrochloride, polyallylamine amide sulfate, allylamine hydrochloride/diallylamine hydrochloride copolymer, allylamine acetate/diallylamine acetate copolymer, allylamine acetate/diallylamine acetate copolymer, allylamine hydrochloride/ Dimethylallylamine hydrochloride copolymer, allylamine/dimethylallylamine copolymer, polydiallylamine hydrochloride, polymethyldiallylamine hydrochloride, polymethyldiallylamine amide sulfate, polymethyldiallylamine acetate, polydiallyldimethylammonium chloride, diallylamine acetate/sulfur dioxide copolymer, diallylmethylethylammonium ethylsulfate/sulfur dioxide copolymer, methyldiallylamine hydrochloride/sulfur dioxide copolymer
  • a free-type polyallylamine resin that is not neutralized with an acid may be used, other than the above acid salt type.
  • the free type type is used for a processing liquid containing water, the pH of the processing liquid can be easily adjusted from neutral to alkaline side, and durability and corrosion of ink jet recording device members are prevented.
  • free-type polyallylamine resins include PAA-01, PAA-03, PAA-05, PAA-08, PAA-15, PAA-15C, and PAA-25 (trade names, manufactured by Nittobo Medical). .
  • the content of the cationic polymer is preferably within the range of 1 to 5% by mass with respect to the total mass of the treatment liquid.
  • organic acid From the viewpoint of the storage stability of the treatment liquid and from the viewpoint of suppressing blocking after coating and drying the treatment liquid, organic acids are preferred among the acids.
  • the organic acid can aggregate the anionic components such as the coloring material in the ink by changing the pH.
  • organic acids include formic acid, acetic acid, propionic acid, isobutyric acid, oxalic acid, fumaric acid, malic acid, citric acid, malonic acid, succinic acid, maleic acid, benzoic acid, 2-pyrrolidone-5-carboxylic acid, Examples include lactic acid, acrylic acid or derivatives thereof, methacrylic acid or derivatives thereof, acrylamide or derivatives thereof, sulfonic acid derivatives and the like. These may be used singly or in combination of two or more.
  • an organic acid that has not been completely neutralized with a base.
  • Neutralization with a base means that the acidic groups of these acids are ionically bonded with other positively charged elements or compounds (eg, inorganic compounds such as metals).
  • not completely neutralized means that among the acidic groups of the organic acid, there are acidic groups that do not form the above ionic bond.
  • Acids other than organic acids include inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid. These may be used singly or in combination of two or more.
  • the content of the acid is preferably 5% by mass or less, more preferably in the range of 0.1 to 3% by mass, more preferably 0.5 to 1.0% by mass, relative to the total mass of the treatment liquid. % range is more preferred. Within the above range, the anionic components such as the coloring material in the ink can be effectively aggregated, so that both image quality and hot water resistance can be achieved.
  • the acid content can be measured by a known method such as high performance liquid chromatography (HPLC).
  • the amount of acid applied is preferably equal to or less than the neutralization equivalent of the anionic component in the ink, and the amount of application of the treatment liquid is preferably adjusted so as to fall within the above range. .
  • the treatment liquid according to the present invention can reduce the content of organic solvents such as VOCs (volatile organic compounds) as compared with solvent inks.
  • Water is not particularly limited, and ion-exchanged water, distilled water, or pure water can be used.
  • the content of water in the treatment liquid is preferably in the range of 50 to 90% by weight with respect to the total weight of the treatment liquid.
  • the treatment liquid according to the present invention can improve the wettability of the treatment liquid on the recording medium and the moisture retention of the treatment liquid.
  • the organic solvent is preferably a water-soluble organic solvent such as alcohols, polyhydric alcohols, amines, amides, glycol ethers, and 1,2-alkanediols having 4 or more carbon atoms. and the like, and the same organic solvents as those contained in the ink described above can be used.
  • the content of the organic solvent in the treatment liquid is preferably in the range of 5 to 45% by weight with respect to the total weight of the treatment liquid.
  • the treatment liquid according to the present invention may appropriately contain other components such as a surfactant, a cross-linking agent, an antifungal agent, and a bactericide within a range that does not impair the effects of the present invention.
  • Various known additives such as lubricants, preservatives, thickeners and antistatic agents may be incorporated.
  • the viscosity of the treatment liquid according to the present invention at a shear rate of 1000 [1/s] at 25° C. is preferably 15 mPa ⁇ s (15 cP) or less, and preferably 5 to 10 mPa ⁇ s. It is preferably within the range of s.
  • the viscosity at a shear rate of 1000 [1/s] at 25° C. can be measured using a rotational rheometer such as MCR-102 manufactured by Anton Paar in the same manner as the apparent viscosity ⁇ a below.
  • the ink set for inkjet recording of the present invention is an ink set for inkjet recording containing an ink and a treatment liquid, and it is preferable that the ink and the treatment liquid coalesce with each other on the surface of the recording medium. That is, it is preferable that the ink in the liquid state and the treatment liquid are mixed on the surface of the recording medium, and the mixed liquid is used to form an image.
  • the ink and the treatment liquid do not have to be completely mixed, and only need to be partially mixed.
  • a mixture in which the ink and the treatment liquid are completely mixed or partially mixed is referred to as a "mixed liquid”.
  • liquid ink and treatment liquid can be mixed on the surface of the recording medium.
  • the wet-on-wet method will be described later in detail.
  • the ink according to the present invention (including the thickener) and the ink excluding the thickener are examined. can be determined by mixing with the processing liquid and comparing the viscosities of the mixture.
  • the coloring material in the ink reacts with the coagulant in the treatment liquid, causing the coloring material in the ink to aggregate, and the viscosity of the mixed liquid of the ink and the treatment liquid increases.
  • the pinning property is good, and bleeding between ink droplets and color unevenness can be suppressed.
  • inks that do not contain a compound that inhibits overaggregation of the colorant when the ink and treatment liquid are applied onto the recording medium in the wet-on-wet method, overaggregation tends to occur, and the mixing of the ink and the treatment liquid tends to occur.
  • the viscosity of the liquid increases greatly.
  • the ink contains a compound having a function of inhibiting overaggregation of the coloring material
  • the viscosity of the mixed liquid increases, but the rate of change in viscosity becomes moderate. Therefore, in the present invention, whether or not the thickener has a function of inhibiting overaggregation of the coloring material is determined by the ink (including the thickener) according to the present invention and the thickener in the ink. can be determined by comparing the rate of change in the viscosity of a sample obtained by mixing each sample with the treatment liquid and the sample obtained by mixing the sample with the processing liquid.
  • the following method can be used to determine whether or not the thickener has a function of inhibiting excessive aggregation of the coloring material.
  • composition A The ink of the present invention (including the thickener of the present invention) is designated as composition A, and the ink excluding the thickener of the present invention (water is added instead of the thickener) is composed.
  • Composition B is obtained by mixing Composition A and the treatment liquid according to the present invention
  • Composition C is obtained by mixing Composition A and the treatment liquid according to the present invention
  • Composition D is obtained by mixing Composition B and the treatment liquid according to the present invention.
  • the viscosities of compositions A and B at a shear rate of 1000 [1 / s] at 25 ° C. are V A and V B
  • V C and V D are V C and V D respectively, and when V A to V D satisfy the following relational expressions (1) and (2), it can be determined that the thickener has a function of inhibiting excessive aggregation of the coloring material.
  • composition C and composition D the mixing ratio (mixing ratio of composition A or B and treatment liquid) is not particularly limited, and the preferred range is Although different, it is preferable to mix the treatment liquid within the range of 10 to 100% by mass with respect to the total mass of composition A or B.
  • the viscosity at a shear rate of 1000 [1/s] at 25° C. can be measured using a rotary rheometer, for example, MCR-102 manufactured by Anton Paar, in the same manner as the apparent viscosity ⁇ a described above.
  • the viscosity of the mixture according to the present invention at a shear rate of 2 [1/s] at 25°C is preferably 15 mPa ⁇ s (15 cP) or more.
  • the viscosity at a shear rate of 2 [1 / s] at 25 ° C. is measured using a rotary rheometer, such as MCR-102 manufactured by Anton Paar, E-type viscometer (TVE-33LT, manufactured by Toki Sangyo Co., Ltd.), etc. can be measured
  • the viscosity of a sample can be measured at a prescribed shear rate by varying the rotational speed (rotational speed) of the cone rotor of the E-type viscometer. Specifically, the viscosity is measured under the condition that the rotation speed is 20 rpm, that is, the shear rate is 2 [1/s].
  • the thickener has a function of inhibiting overaggregation of the coloring material is determined by comparing the ink (including the thickener) according to the present invention and the ink excluding the thickener. , are mixed with the treatment liquid, and the ratio of the number of coarse particles in the mixture is compared.
  • the ratio of the number of coarse particles of 5 ⁇ m or more can be calculated by the following method. After diluting the compositions C and D 10,000 times with pure water, using a particle counter (manufactured by RION, sensor: PARTICLE SENSOR KS-42C, controller: CONTROLLER KE-40B1, pump: SYRINGE SAMPLER KZ-31W) , and the flow rate is 10 mL/min. The number of particles is measured three times, and the average value is adopted.
  • composition C and composition D the ratio of the number of particles with a particle size of 5 ⁇ m or more to the total number of particles (total number of particles with the above particle size) is defined as R C and R D respectively, and the ratio (R C / R D ) is calculated.
  • the ink jet recording method of the present invention is characterized in that the ink set for ink jet recording of the present invention is used, and the ink and the treatment liquid are united with each other on the surface of the recording medium.
  • a recording method in which the ink and the treatment liquid are combined with each other on the surface of the recording medium for recording is called a “wet-on-wet method”.
  • the liquid ink and the treatment liquid coalesce (mix) on the surface of the recording medium, increasing the chances of contact between the coloring material in the ink and the coagulant in the treatment liquid. Aggregation progresses sufficiently.
  • the particle size of aggregates composed of the aggregating agent and the colorant becomes too large, that is, excessive aggregation tends to occur, resulting in a problem of deterioration in image quality.
  • the ink set of the present invention over-aggregation is suppressed, and a good image quality recorded matter can be obtained.
  • the ink set of the present invention exhibits remarkable effects during wet-on-wet inkjet recording.
  • wet-on-wet recording by inkjet recording not only provides good image quality, but also allows ink to be applied immediately after applying the treatment liquid. Drying time can be shortened, treatment liquid is not applied to areas not coated with ink, so the texture of the base material can be utilized, and treatment liquid application and ink application can be performed with a single printer. and other advantages.
  • the inkjet recording method of the present invention comprises: 1) a treatment liquid application step of applying a treatment liquid to the surface of a recording medium; 2) an ink application step of applying ink onto the applied treatment liquid; and 3) application to the surface of a recording medium. and a mixed liquid drying step of drying the mixed liquid of the treated liquid and the ink.
  • the treatment liquid application process may be performed before, after, or at the same time as the ink application process, and the mixed liquid drying process is performed after the treatment liquid application process and the ink application process.
  • the recording medium that can be used in the present invention is not particularly limited, but by using the ink set for inkjet recording described above, the ejection stability of the ink is good, and the image quality of the recorded matter is improved. Therefore, it is preferable that the recording medium has low or no absorbency.
  • absorbency refers to absorbency for water-based ink.
  • a well-known plastic film can be used as a recording medium with low or no absorbency.
  • Specific examples include polyester films such as polyethylene terephthalate, polyethylene films, polypropylene films, polyamide films such as nylon, polystyrene films, polyvinyl chloride films, polycarbonate films, polyacrylonitrile films, biodegradable films such as polylactic acid films, and the like. is mentioned.
  • a film coated with polyvinylidene chloride on one or both sides thereof, or a film deposited with a metal oxide can also be preferably used.
  • the film can be preferably used whether it is an unstretched film or a stretched film.
  • the thickness of the recording medium is preferably in the range of 10-120 ⁇ m, more preferably in the range of 12-60 ⁇ m.
  • metals such as tin plates for three-piece cans and tin-free steel plates (TFS plates, thickness within the range of 0.1 to 0.6 ⁇ m) are preferably used.
  • TFS plates tin-free steel plates
  • the packaging materials for canned foods for example, block air, moisture, and light, and seal the food inside. It is common to use acrylic or acrylic thermosetting paints.
  • Treatment liquid application process In the treatment liquid application process, the above-described treatment liquid is applied to the surface of the recording medium.
  • the treatment liquid is applied to the surface of the recording medium using an inkjet method, similar to the ink described later.
  • the application amount can be finely controlled, and an appropriate amount of treatment liquid can be applied according to the application amount of the ink.
  • the ink coating film may crack and image quality may deteriorate. There is a possibility that the image quality will deteriorate due to the appearance of graininess due to waves. Therefore, it is preferable to finely control the application amount of the treatment liquid, and the application amount of the treatment liquid is controlled by changing the printing rate or the droplet amount of the treatment liquid according to the absorbency of the recording medium and the application amount of the ink. is preferred.
  • a suitable amount of the treatment liquid to be applied varies depending on the constituents of the ink and the treatment liquid, but is preferably in the range of 10 to 100% by mass with respect to the total mass of the ink.
  • the ink is applied to the surface of the recording medium using an inkjet method.
  • the application amount can be finely controlled.
  • a printer equipped with an inkjet head loaded with ink can be used.
  • recording can be performed by ejecting ink droplets from nozzles of an inkjet head based on a digital signal and then landing the droplets on the surface of a recording medium.
  • the inkjet head may be either an on-demand type or a continuous type.
  • on-demand inkjet heads include electro-mechanical conversion, including single-cavity, double-cavity, bender, piston, shear mode and shared wall, and thermal inkjet and bubble jet. (registered trademark, Canon Inc.) type, and other electric-heat conversion methods.
  • an inkjet head (also referred to as a "piezo inkjet head") using a piezoelectric element as an electro-mechanical conversion element used in an electro-mechanical conversion system is preferable.
  • the inkjet head may be either a scanning type inkjet head or a single-pass type inkjet head, but the single-pass type is preferable.
  • the single pass method it is preferable to use a line head type inkjet head.
  • a line head type inkjet head is an inkjet head that has a length greater than the width of the recording area.
  • a single head having a width equal to or larger than the recording range may be used, or a plurality of heads may be combined to form an ink jet head having a width equal to or larger than the recording range.
  • a plurality of heads may be arranged side by side so that their nozzles are staggered to increase the resolution of the heads as a whole.
  • the transport speed of the recording medium can be set, for example, within the range of 1 to 120 m/min.
  • the faster the conveying speed the faster the recording speed.
  • even at a very high linear velocity in the range of 50 to 120 m/min, which is applicable to the single-pass inkjet recording method the ink fixability is high and high-definition recorded matter is produced. can be obtained.
  • the drying temperature is preferably 220°C or less, preferably in the range of 50 to 150°C.
  • the drying time is not particularly limited, but it is preferably a time during which the solvent can be sufficiently removed.
  • the mixed liquid may be dried, for example, using a non-contact heating drying device such as a drying furnace or a hot air blower, or using a contact heating drying device such as a hot plate or a hot roller. you can go
  • the drying temperature is (a) when using a non-contact heating drying device such as a drying furnace or a hot air blower, the temperature in the furnace or the atmosphere temperature such as the hot air temperature, and (b) the temperature of the hot plate, the heat roller, etc.
  • a non-contact heating drying device such as a drying furnace or a hot air blower
  • the temperature in the furnace or the atmosphere temperature such as the hot air temperature
  • the temperature of the hot plate, the heat roller, etc is measured during the entire period of the mixed liquid drying process. obtained by As for the drying temperature, it is preferable to measure (c) the surface temperature of the surface to be dried.
  • the inkjet recording apparatus of the present invention uses the inkjet recording ink set of the present invention, the inkjet recording apparatus has an inkjet head for ink and an inkjet head for treatment liquid, and the inkjet head for ink and the inkjet head for treatment liquid.
  • the heads are mounted on the same carriage, or the inkjet head for ink and the inkjet head for treatment liquid are mounted on separate carriages, and the carriages are adjacent to each other without a drying mechanism in between. and
  • the ink set for inkjet recording of the present invention can use a wet-on-wet method. Ink can be ejected immediately thereafter. Therefore, the inkjet head for ink and the inkjet head for treatment liquid can be mounted on the same carriage.
  • the inkjet recording apparatus of the present invention can be downsized and the recording time can be shortened.
  • the inkjet recording apparatus 200 includes a paper feed section 210, an image recording section 220, a paper discharge section 230, an ink circulation device 8 (see FIG. 3) as ink supply means, and a controller. section (see FIG. 4) and the like.
  • the inkjet recording apparatus 200 conveys the recording medium M stored in the paper feeding section 210 to the image recording section 220, forms an image on the recording medium M in the image recording section 220, and ejects the recording medium M on which the image is formed. It is conveyed to the paper section 230 .
  • the paper feed unit 210 has a paper feed tray 211 that stores the recording medium M, and a medium supply unit 212 that conveys and supplies the recording medium M from the paper feed tray 211 to the image recording unit 220 .
  • the medium supply unit 212 includes a ring-shaped belt whose inner side is supported by two rollers, and the recording medium M is fed from the paper feed tray 211 by rotating the rollers while the recording medium M is placed on the belt. It is conveyed to the image recording section 220 .
  • the image recording section 220 has a conveying drum 221, a delivery unit 222, a heating section 223, a carriage 224, a fixing section 225, a delivery section 226, and the like.
  • the transport drum 221 has a cylindrical surface, and its outer peripheral surface serves as a transport surface on which the recording medium M is placed.
  • the conveying drum 221 conveys the recording medium M along the conveying surface by rotating in the direction of the arrow in FIG. 1 while holding the recording medium M on the conveying surface.
  • the conveying drum 221 includes a claw portion and a suction portion (not shown). holds the recording medium M.
  • the transfer unit 222 is provided between the medium supply unit 212 of the paper supply unit 210 and the transport drum 221, and picks up the recording medium M transported from the medium supply unit 212 by holding one end of the recording medium M transported from the medium supply unit 212 with the swing arm 222a. , to the transport drum 221 via the delivery drum 222b.
  • the heating unit 223 is provided between the arrangement position of the delivery drum 222b and the arrangement position of the carriage 224, and heats the recording medium M conveyed by the conveying drum 221 so that the temperature of the recording medium M is within a predetermined temperature range. to heat.
  • the heating unit 223 has, for example, an infrared heater or the like, and energizes the infrared heater based on a control signal supplied from a control unit (not shown) to cause the heater to generate heat.
  • the "carriage” refers to what supports the inkjet head.
  • the carriage is not particularly limited as long as it can support the inkjet head, and the carriage may or may not be equipped with an ink tank.
  • the inkjet head 100 arranged in the carriage 224 ejects ink onto the recording medium M at an appropriate timing according to the rotation of the transport drum 221 holding the recording medium M based on the image data to form an image.
  • the carriage 224 is arranged with an ink ejection surface facing the transport drum 221 at a predetermined distance.
  • four carriages 224 corresponding to four colors of ink, yellow (Y), magenta (M), cyan (C), and black (K), move the recording medium M.
  • the colors are arranged in the order of Y, M, C, and K from the upstream side in the transport direction so as to be arranged at predetermined intervals.
  • a pair of inkjet heads 100 adjacent in the front-rear direction are arranged in a zigzag pattern at different positions in the front-rear direction.
  • drying of the ink by heating the ink or the recording medium is usually used as a method of fixing (pinning) the ink on the recording medium.
  • this method is applied to an inkjet head arranged in a zigzag arrangement, the timing at which the ink droplets land is shifted, and color unevenness is likely to occur due to the difference in the drying time of the droplets.
  • the ink is fixed using the treatment liquid, and pinning due to drying is unnecessary, so color unevenness and image quality unevenness due to drying time differences are less likely to occur.
  • the present invention employs a wet-on-wet method using inkjet recording, even if there is a difference in the landing timing of the treatment liquid and the ink, it has little effect on the image quality, and good image quality can be obtained. , and an ink jet head arranged in a zigzag manner.
  • the inkjet recording apparatus 200 is an inkjet recording apparatus 200 that performs image recording by a one-pass drawing method using a line head, and the carriage 224 is moved relative to the rotating shaft of the conveying drum 221 during image recording. Position is fixed and used.
  • the ink jet recording apparatus of the present invention may be of a scanning type, in which the carriage reciprocates in the sub-scanning direction.
  • the fixing unit 225 dries and fixes the mixed liquid of the ink and the treatment liquid ejected onto the recording medium M.
  • the delivery unit 226 has a belt loop 226b having a ring-shaped belt whose inside is supported by two rollers, and a cylindrical delivery drum 226a that delivers the recording medium M from the transport drum 221 to the belt loop 226b.
  • the recording medium M transferred from the conveying drum 221 onto the belt loop 226b by the transfer drum 226a is conveyed by the belt loop 226b and delivered to the paper ejection section 230.
  • the paper discharge section 230 has a plate-shaped paper discharge tray 231 on which the recording medium P delivered from the image recording section 220 by the delivery section 226 is placed.
  • the ink set for inkjet recording of the present invention is preferably discharged from an inkjet recording apparatus having a circulation mechanism.
  • inks according to the present invention inks with relatively high thixotropic properties can suppress an increase in the viscosity of the ink by circulating the ink, and good ejection stability can be obtained.
  • the ink circulation device 8 is an ink supply means for generating a circulation flow of ink from pressure chambers (not shown) in the inkjet head 100 to individual ink discharge paths (not shown).
  • the ink circulation device 8 is composed of a supply sub-tank 81, a circulation sub-tank 82, a main tank 83, and the like (see FIG. 3).
  • the supply sub-tank 81 is filled with ink to be supplied to the ink reservoir 51 of the manifold 5 and is connected to the first ink port 53 by an ink flow path 84 .
  • the circulation sub-tank 82 is filled with ink discharged from a discharge liquid chamber (not shown) of the manifold 5 and is connected to the fourth ink port 56 by an ink channel 85 .
  • the supply sub-tank 81 and the circulation sub-tank 82 are provided at different positions in the vertical direction (gravitational direction) with respect to the nozzle surface of the inkjet head 100 (hereinafter also referred to as the "position reference plane").
  • a pressure P1 due to a water head difference between the position reference plane and the supply sub-tank 81 and a pressure P2 due to a water head difference between the position reference plane and the circulation sub-tank 82 are generated.
  • the supply sub-tank 81 and the circulation sub-tank 82 are connected by an ink flow path 86 . Then, the pressure applied by the pump 88 can return the ink from the circulation sub-tank 82 to the supply sub-tank 81 .
  • the main tank 83 is filled with ink to be supplied to the supply sub-tank 81 and is connected to the supply sub-tank 81 by an ink flow path 87 . Ink can be supplied from the main tank 83 to the supply sub-tank 81 by the pressure applied by the pump 89 .
  • the pressure P1 and the pressure P2 can be adjusted by appropriately changing the amount of ink filled in each sub-tank and the position of each sub-tank in the vertical direction (the direction of gravity).
  • the pressure difference between the pressures P1 and P2 allows the ink in the inkjet head 100 to circulate at an appropriate circulation flow rate. As a result, it is possible to remove air bubbles, foreign matter, and the like generated in the head chip of the inkjet head, thereby suppressing nozzle clogging, ejection failure, and the like.
  • the ink circulation device 8 As an example of the ink circulation device 8, the method of controlling the circulation of ink by using the difference in water head has been described, but it is naturally possible to make appropriate modifications as long as the configuration is capable of generating a circulating flow of ink.
  • the ink circulation mechanism is bidirectional circulation. By switching the driving direction of the pump between the forward direction and the reverse direction, the direction of the circulating flow of ink can be changed.
  • FIG. 4 is a block diagram showing the main functional configuration of the inkjet printing apparatus.
  • the inkjet recording apparatus 200 includes the paper feeding section 210, the image recording section 220 (the conveying drum 221, the transfer unit 222, the heating section 223, the carriage 224, the fixing section 225, and the delivery section 226), and the paper discharging section 230. , an ink circulation device 8 as ink supply means, a controller 240 and the like.
  • the control section 240 is connected to each section that configures the inkjet recording apparatus 200 and controls each section that configures the inkjet recording apparatus 200 .
  • the control unit 240 has a CPU 241, a RAM 242, a ROM 243, and the like.
  • the CPU 241 reads and executes various programs, data, and the like according to the content of processing from a storage device such as the ROM 243, and controls the operation of each unit of the inkjet recording apparatus 200 according to the content of the executed processing.
  • the RAM 242 temporarily stores various programs and data processed by the CPU 241 .
  • the ROM 243 stores various programs and data read by the CPU 241 and the like.
  • the control unit 240 performs the following processing on the ink circulation device 8 of the inkjet recording device 200 .
  • the control unit 240 controls the flow rate (circulation flow rate Q) of ink flowing through the flow path R communicating with the nozzles of the inkjet head, that is, the circulation differential pressure ⁇ P, so that the average shear velocity of the flow path R communicating with the nozzle is can be adjusted.
  • the average shear rate of the flow path R is preferably 100 [1/s] or more.
  • the pressure P1 and the pressure P1 and the The pressure P2 is adjusted, and the circulation flow rate Q is controlled by the pressure difference (circulation differential pressure ⁇ P) between the pressures P1 and P2.
  • the circulation differential pressure ⁇ P is preferably within the range of 5 to 30 kPa.
  • a recorded matter formed using the ink set for inkjet recording of the present invention preferably has an ink layer formed using a mixture of ink and treatment liquid on the surface of the recording medium.
  • another functional layer may be provided between the recording medium and the ink layer. may be pasted together.
  • a layer containing a thermosetting resin, the ink layer, and a layer containing a thermosetting resin are preferably laminated in this order on a metal substrate.
  • examples include packaging materials for packaging canned foods, retort-packed foods, beverages, and the like.
  • Recording media with low or no absorbency include, for example, PET film (FE2001, manufactured by Futamura Chemical Co., Ltd.). Thus, a recorded matter with improved image quality can be obtained.
  • thermosetting resin for example, TW-1407 series manufactured by T&K TOKA
  • base coat a thermosetting resin layer
  • thermosetting resin layer a thermosetting resin layer (base coat)
  • thermosetting resin layer top coat
  • thermosetting resin layer top coat
  • composition A ⁇ Preparation and Evaluation of Ink (Composition A)>> Ink compositions 1A to 37A were prepared and evaluated.
  • Pigment Dispersions D1-D3 were prepared as follows. The average particle size of the pigment particles contained in each pigment dispersion was D1: 150 nm, D2: 100 nm, and D3: 220 nm. The average particle size was measured using "Zetasizer Nano S-90" manufactured by Maruballoon.
  • Pigment Dispersion D1 Preparation of Pigment Dispersion D1 After mixing and premixing the following components, the mixture was dispersed using a bead mill filled with 50% by volume of 0.3 mm zirconia beads to prepare a pigment dispersion D1 having a pigment content of 20% by mass.
  • Magenta pigment (mixed crystal of Pigment Red 122 and Pigment Violet 19) 20% by mass Pigment dispersant (acrylic dispersant having a carboxyl group neutralized with dimethylaminoethanol (manufactured by BASF, Joncryl (registered trademark) 819, acid value 75 mgKOH/g, solid content 20% by mass)) 8% by mass Propylene glycol 20% by mass Antifungal agent (Proxel GXL (S) manufactured by Lonza) 0.1% by mass Ion-exchanged water (Remainder; amount to make the total amount 100% by mass)
  • Pigment Dispersion D2 was prepared in the same manner as Pigment Dispersion D1, except that the magenta pigment of Pigment Dispersion D1 was changed to cyan pigment (pigment blue 15:3) at 20% by weight.
  • Pigment Dispersion D3 After mixing and premixing the following components, the mixture was dispersed using a bead mill filled with 50% by volume of 0.3 mm zirconia beads to prepare a pigment dispersion D3 having a pigment content of 40% by mass.
  • Titanium oxide pigment 40% by mass Pigment dispersant (Joncryl (registered trademark) 819, acid value 75 mgKOH/g, solid content 20% by mass, manufactured by BASF) 4% by mass Propylene glycol 20% by mass Antifungal agent (Proxel GXL (S) manufactured by Lonza) 0.1% by mass Ion-exchanged water (Remainder; amount to make the total amount 100% by mass)
  • Pigment dispersant Joncryl (registered trademark) 819, acid value 75 mgKOH/g, solid content 20% by mass, manufactured by BASF
  • Propylene glycol 20% by mass
  • Antifungal agent Proxel GXL (S) manufactured by Lonza
  • Ion-exchanged water Remainder; amount to make the total amount 100% by mass
  • composition 1A The following components were mixed, and the resulting mixture was filtered through a 1 ⁇ m filter to prepare composition 1A. There was no substantial compositional change before and after filtration.
  • Pigment dispersion D1 20% by mass (4% by mass as solid content)
  • Thickener a manufactured by BYK-Chemie, BYK (registered trademark)-425
  • Resin fine particle dispersion P1 the amount added is adjusted so that the resin fine particles (solid content) is 5% by mass in composition 1A
  • Surfactant TEGO (registered trademark) WET-KL245, manufactured by Evonik
  • TEGO registered trademark
  • WET-KL245 manufactured by Evonik
  • Antifungal agent Proxel GXL (S), manufactured by Lonza
  • Ion-exchanged water Remainder; amount to make the total amount 100% by mass
  • composition 2A was prepared in the same manner as in the preparation of composition 1A, except that the types and amounts of the thickener, pigment dispersion, organic solvent, resin and surfactant were changed as shown in Tables I and II below.
  • ⁇ 37A was prepared. Numerical values for thickeners, pigment dispersions, organic solvents, resins, surfactants, and antifungal agents in Tables I and II represent the percentage of the total mass of composition A, and the "-" indicates the corresponding component. indicates that it does not contain
  • the numerical values in the "thickening agent ratio" in Tables I and II are the amount of coloring material added (3A: 8% by mass, 33A: 10% by mass, 34A: 3% by mass, others: 4% by mass).
  • the ratio of the added amount of the sticky agent is represented, and the numerical value in the "organic solvent total amount” represents the ratio of the total amount of the organic solvents a to e and the organic solvent contained in the pigment dispersion with respect to the total mass of the composition A.
  • all units of numerical values are [% by mass].
  • compositions 1B-37B were prepared in the same manner as in the preparation of compositions 1A to 37A, except that the thickener was changed to pure water.
  • 36B was the same component and addition amount as 36A.
  • each component in Tables I and II is as follows.
  • Viscosity> The viscosities of the compositions A and B were measured in the rotation mode of MCR-102 at a temperature of 25 ° C., a time setting of 150 measurement points, a measurement interval of 2 s, and a shear rate of 1000 [1 / s] to 1 [. 1/s], and the values at a shear rate of 1000 [1/s] were taken as VA and VB .
  • ⁇ Thixotropic Index> Create a logarithmic graph with the viscosity ⁇ a [mPa s] measured above on the vertical axis (Y-axis) and the shear rate [1/s] on the horizontal axis (X-axis).
  • the thixotropic index n was obtained from 1).
  • ⁇ Ejection stability> A Konica Minolta independently driven inkjet head (360 npi, ejection volume 6 pL, 1024 nozzles) was filled with Composition A, and a continuous ejection test was conducted for 30 minutes using a stroboscope-synchronized droplet observation device. After that, ejection stability was evaluated according to the following criteria. In addition, ⁇ or more was regarded as practically no problem. A: Out of the 256 nozzles evaluated, all 256 nozzles ejected normally. ⁇ : Out of the 256 nozzles evaluated, 1 or more and 4 or less abnormal nozzles were observed. ⁇ : Out of the 256 nozzles evaluated, 5 to 9 abnormal ejection nozzles were observed. x: Out of the 256 nozzles evaluated, 10 or more abnormal discharge nozzles were observed.
  • ⁇ A coating film was formed, and color transfer occurred when the coating film was rubbed with a finger, but no color transfer occurred when the coating film was pressed with a finger.
  • ⁇ A coating film was formed, and color transfer occurred even when the coating film was pressed with a finger.
  • x A coating film was not formed.
  • the ink according to the present invention has good ejection stability, has a viscosity of 15 mPa s or less at a shear rate of 1000 [1/s] at 25°C, and has a thixotropic index at 25°C. is in the range of 0.85 to 1.0, more favorable ejection stability can be obtained.
  • the ink according to the present invention has good drying properties, and furthermore, the content of the organic solvent in the ink (composition A) is 25% by mass or less in comparison with composition 22A and others. It can be seen that the effect is remarkable. Further, from a comparison of Composition 32A with Compositions 1A and 31A, it was found that good ejection stability can be obtained when the content of the organic solvent in the ink (Composition A) is 5% by mass or more. Recognize.
  • Treatment liquids 1 to 12 according to the present invention were prepared and evaluated.
  • a treatment liquid 1 was prepared by mixing the following components and filtering the resulting mixed liquid through a 1 ⁇ m filter.
  • Treatment solutions 2 to 12 were prepared in the same manner as in the preparation of treatment solution 1, except that the types and amounts of flocculants, organic solvents, surfactants, and thickeners were changed as shown in Table IV below. .
  • the organic solvents, surfactants and thickeners in Table IV are synonymous with the components used in the preparation of the ink, and other organic solvents and flocculants not used in the preparation of the ink are described below It is as follows.
  • the ejection stability was evaluated for the treatment liquids 1 to 12.
  • the evaluation method has the same meaning as the method for evaluating the ejection stability of the ink. Evaluation results are shown in Table IV.
  • composition C and composition D the ratio of the number of particles with a particle size of 5 ⁇ m or more to the total number of particles (total number of particles with the above particle size) is defined as R 1C and R 1D , respectively, and the ratio (R 1C / R 1D ) was calculated.
  • Printing was carried out unidirectionally in the direction recorded in the The conveying speed of the carriage was set to 300 mm/sec, and no drying process was provided between the recording of the treatment liquid and the ink.
  • a PET film (FE2001, thickness 50 ⁇ m, manufactured by Futamura Chemical Co., Ltd.) was used as a recording medium. After printing, the recording medium was placed in a dryer set at 90° C. and dried by heating for 5 minutes to obtain a recorded matter.
  • the recorded matter was subjected to the following image quality evaluation.
  • ⁇ Smoothness> A solid image of 5 cm ⁇ 5 cm was recorded by the above method, and the presence or absence of surface gloss and unevenness was evaluated. In addition, 0 or more was regarded as no practical problem.
  • ⁇ Reflection of light was observed when observed in a bright place, and no surface unevenness was observed when traced with a finger.
  • ⁇ No light reflection was observed when observed in a bright place, but no surface unevenness was observed when traced with a finger.
  • x No reflection of light was observed when observed in a bright place, and surface unevenness was felt when traced with a finger.
  • ink set 47 does not provide good ejection stability for composition A, and does not provide good image quality (printing quality and smoothness) of recorded matter.
  • Ink set 48 does not provide good smoothness of the recorded matter, and it can be seen that the thickener g contained in composition A does not have the function of inhibiting overaggregation of the coloring material.
  • the ink set of the present invention has good ink ejection stability, and furthermore, the image quality of the printed matter is improved.
  • a comparison between ink sets 6 and 7 and others shows that the print quality is improved when V C ⁇ V D .
  • a comparison of ink sets 4 to 7 and 11 to 12 with others shows that printing quality is improved when R C /R D ⁇ 1.
  • the content of the thickening agent It can be seen that printing quality is improved when the content is in the range of 5 to 100% by mass.
  • a comparison between ink set 27 and ink sets 1 and 23 to 25 shows that printing quality is improved when the thickener has at least a hydrophilic portion and a hydrophobic portion in the same particle.
  • a comparison of ink set 11 with ink sets 1 to 5 and 12 shows that the use of a polyvalent metal salt, cationic polymer, or organic acid as the aggregating agent improves print quality and smoothness.
  • a comparison between Set 12 and Ink Sets 1 to 3 shows that the polyvalent metal salt containing at least calcium salt or magnesium salt improves print quality and smoothness.
  • a comparison of the ink sets 22 and 43 with the others shows that the printing quality is improved when the V C is 15 mPa ⁇ s or more.
  • the ink set for ink jet recording of the present invention it is possible to record with good image quality on a recording medium with low or no absorbency. can be applied.
  • Manifold 6 Housing 8 Ink circulation device 53 First ink port 56 Fourth ink port 81 Supply sub-tank 82 Circulation sub-tank 83 Main tank 86 Ink flow path 88 Pump 100 Inkjet head 200 Inkjet recording device 210 Paper feed unit 220 Image recording Unit 224 Carriage 230 Paper discharge unit 240 Control unit M Recording medium P Recording medium

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Abstract

The present invention addresses the problem of providing: an ink set for ink-jet recording which has satisfactory ink delivery stability and gives prints having improved image quality; an ink-jet recording method; and an ink-jet recording device.　This ink set for ink-jet recording comprises an ink and a treatment liquid, and is characterized in that the ink comprises a thickener, a colorant, water, and an organic solvent and the treatment liquid comprises a coagulant, water, and an organic solvent, the thickener having the function of inhibiting the colorant from excessively coagulating.

Description

インクジェット記録用インクセット、インクジェット記録方法及びインクジェット記録装置INKSET FOR INKJET RECORDING, INKJET RECORDING METHOD AND INKJET RECORDING DEVICE
　本発明は、インクジェット記録用インクセット、インクジェット記録方法及びインクジェット記録装置に関する。より詳しくは、インクの吐出安定性が良好であり、記録物の画質が向上したインクジェット記録用インクセット等に関する。 The present invention relates to an ink set for inkjet recording, an inkjet recording method, and an inkjet recording apparatus. More specifically, the present invention relates to an ink set for ink jet recording, which has good ink ejection stability and improved image quality of recorded matter.
　インクジェット記録（「印刷」ともいう。）方法とは、インクジェットヘッドからインクの小滴を吐出させ、紙等の記録媒体表面に着弾させて行う記録方法である。この方法では、比較的安価な装置で、高解像度及び高品位な画像を高速で印刷することが可能である。 The inkjet recording (also called "printing") method is a recording method in which small droplets of ink are ejected from an inkjet head and landed on the surface of a recording medium such as paper. With this method, it is possible to print high-resolution and high-quality images at high speed with a relatively inexpensive device.
　インクジェット印刷において、特に水性インクを用いた場合、文字や画像のパターンを記録媒体表面に印刷すると、液体成分が記録媒体中に浸透した後乾燥し、インクが定着する。普通紙や専用紙、又は上質紙や再生紙のようなインクの吸収性の高いものを記録媒体とする場合には、インクが定着しやすく高品質の画像を提供することができるが、コート紙やアート紙、微塗工紙、フィルムのような吸収性の低い・無いものを記録媒体とする場合には、インクの液滴が記録媒体中に浸透しづらいため、浸透による乾燥が起きず、液滴同士でにじみが発生し、画質が損なわれていた。 In inkjet printing, especially when water-based ink is used, when a character or image pattern is printed on the surface of a recording medium, the liquid component permeates the recording medium and then dries, fixing the ink. When using plain paper, special paper, high-quality paper, or recycled paper with high ink absorption as the recording medium, the ink can be easily fixed and a high-quality image can be provided. When using a recording medium with low or no absorbency such as , art paper, lightly coated paper, or film, the ink droplets do not easily penetrate into the recording medium, so drying does not occur due to penetration. Bleeding occurred between the droplets, and the image quality was impaired.
　記録物（印刷物）の画質を向上させるためには、記録媒体表面において、インクは粘度が高く、すぐに固定化することが好ましい。一方、インクジェットヘッドからインクを吐出する際、インクの粘度が高すぎると、必要な量を必要な場所に安定して吐出することが難しくなる。そのため、インクは、吐出安定性が良好であり、かつ、記録媒体表面では素早く固定化することが好ましい。 In order to improve the image quality of the recorded matter (printed matter), it is preferable that the ink has high viscosity on the surface of the recording medium and is quickly fixed. On the other hand, when the ink is ejected from the inkjet head, if the viscosity of the ink is too high, it becomes difficult to stably eject the required amount to the required location. Therefore, it is preferable that the ink has good ejection stability and is quickly fixed on the surface of the recording medium.
　特許文献１では、せん断力の支配が強い場合の粘度とせん断力の支配が弱い場合の粘度の比が一定値以上である水性インクジェットインクの技術が開示されている。当該インクは、いわゆるチキソ性が比較的高いため、せん断力を受けると粘度は低下するが、せん断力を受けず静止したままであると粘度は比較的高い。 Patent Literature 1 discloses a technique for an aqueous inkjet ink in which the ratio of the viscosity when the shearing force is strongly controlled and the viscosity when the shearing force is weakly controlled is a certain value or more. Since the ink has relatively high so-called thixotropic properties, the viscosity decreases when subjected to a shearing force, but the viscosity is relatively high when the ink remains stationary without being subjected to a shearing force.
　そのため、記録媒体表面ではすぐにインクを固定化することができるが、インクジェットヘッドから吐出する際に、せん断力を与えるなどして最適な粘度に調整する必要があり、循環流量等の精密な制御が必要であった。 As a result, the ink can be fixed immediately on the surface of the recording medium, but when it is ejected from the inkjet head, it is necessary to adjust the viscosity to the optimum level by applying a shearing force, etc., and precise control of the circulation flow rate, etc. is required. was necessary.
　また、記録物の画質を向上させる方法として、インクの吸収性の低い・無い記録媒体に処理液を塗布する方法が知られている。処理液（「反応液」ともいう。）としては、インクの液体成分を吸収し乾燥性を向上させる層（インク受容層）を形成するものと、固体成分を凝集しインクの増粘を意図的に引き起こすことでインクの液滴間のにじみや色ムラを防止する層（インク凝集層）を形成するものの二種類が知られている。 Also, as a method of improving the image quality of printed matter, a method of applying a treatment liquid to a recording medium with low or no ink absorption is known. The treatment liquid (also referred to as the "reaction liquid") includes one that forms a layer (ink-receiving layer) that absorbs the liquid components of the ink and improves drying properties, and one that aggregates the solid components to intentionally increase the viscosity of the ink. Two types are known that form a layer (ink aggregation layer) that prevents ink bleeding and color unevenness between ink droplets.
　インク凝集層を形成する方法では、記録媒体表面に、凝集剤を含有する処理液を付与した後、インクを付与し、処理液及びインクが共に液体状態で合一（混合）することにより、インク中の色材を素早く凝集させ、処理液及びインクの混合物を素早く固定化させる方法（以下、「ウェット・オン・ウェット方式」ともいう。）が知られている。 In the method of forming the ink aggregation layer, a treatment liquid containing an aggregating agent is applied to the surface of the recording medium, and then the ink is applied, and the treatment liquid and the ink are combined (mixed) in a liquid state to obtain the ink. A method (hereinafter, also referred to as “wet-on-wet method”) is known for quickly aggregating a coloring material inside and quickly fixing a mixture of a treatment liquid and an ink.
　当該方法では、インクの付与量に対応して、適当量の処理液を付与する必要がある。処理液の付与量が適当量を下回る場合、インクの塗膜にひび割れが生じて画質が低下する可能性があり、処理液の付与量が適当量を上回る場合、ドットの形状の不均化や波寄りによる粒状感が発現し画質が低下する可能性があるためである。また、吸収性の低い・無い記録媒体においては、処理液の付与量が適当量を下回る場合、記録媒体表面に形成された画像が崩れてしまう可能性がある。
　このため、インク及び処理液共に、付与量を細かく制御できるインクジェット法により付与することが好ましい。 In this method, it is necessary to apply an appropriate amount of treatment liquid corresponding to the amount of applied ink. If the amount of treatment liquid applied is less than the appropriate amount, the ink coating film may crack and image quality may deteriorate. This is because there is a possibility that graininess due to waves may appear and the image quality may deteriorate. In addition, in the case of recording media with low or no absorbency, if the amount of treatment liquid to be applied is less than the appropriate amount, there is a possibility that the image formed on the surface of the recording medium will collapse.
For this reason, it is preferable to apply both the ink and the treatment liquid by an ink jet method in which the application amount can be finely controlled.
　特許文献２では、記録媒体と使用するインクの組み合わせの違いによってインクの浸透速度が大きく異なることから、記録媒体とインクの組み合わせに適した処理液及びインクの付与量（付加量）を制御する技術が開示されている。 In Japanese Patent Laid-Open No. 2002-200011, since the ink permeation speed varies greatly depending on the combination of the recording medium and the ink used, a technique for controlling the application amount (addition amount) of the treatment liquid and the ink suitable for the combination of the recording medium and the ink. is disclosed.
　当該技術では、処理液は、ローラーを回動させながら、ブレード状の部材やスポンジ状の部材などを用いて塗布されることが好ましいとされており、また、ローラーの回転速度及び押圧する圧力を制御することにより付与量を調整できるとあるが、処理液はある範囲において一様に塗布される。このため、インクの付与量に対応して、処理液の付与量を細かく制御することは難しい。また、処理液をインクジェット法により付与する方法については、検討されていない。 In this technique, the treatment liquid is preferably applied using a blade-like member or a sponge-like member while rotating the roller. Although it is described that the application amount can be adjusted by controlling, the treatment liquid is applied uniformly over a certain range. Therefore, it is difficult to finely control the application amount of the treatment liquid in correspondence with the application amount of the ink. Further, no study has been made on a method of applying the treatment liquid by an inkjet method.
　特許文献３では、処理液（前処理液）が、樹脂粒子及び増粘剤（疎水変性の水溶性ウレタン樹脂）を含有することにより、処理液の粘度を上昇させ、吸収性の低い・無い記録媒体（非浸透性基材）に対する密着性や、長期の保存安定性を向上させる技術が開示されている。 In Patent Document 3, the processing liquid (pre-treatment liquid) contains resin particles and a thickener (hydrophobic-modified water-soluble urethane resin) to increase the viscosity of the processing liquid, thereby improving the recording properties with low or no absorbency. Techniques for improving adhesion to a medium (non-permeable substrate) and long-term storage stability have been disclosed.
　しかし、当該処理液は、比較的粘度が高いため、インクジェット法により付与する場合、良好な吐出安定性が得られず、さらに、インクジェットヘッドのノズル面に、当該処理液の乾燥物が析出し吐出不良が生じることがわかった。 However, since the treatment liquid has a relatively high viscosity, when applied by an inkjet method, good ejection stability cannot be obtained. It was found to be defective.
　引用文献４では、処理液（反応液）が会合性増粘剤を含有することにより、光学濃度及び耐マーカー性を向上させる技術が開示されている。 Cited Document 4 discloses a technique for improving optical density and marker resistance by including an associative thickener in the treatment liquid (reaction liquid).
　しかし、当該技術では、成膜性及び表面平滑性が低下するため、記録物の光沢性が低下してマット調になることがわかった。また、処理液に多価金属塩を含む場合、多価金属塩と会合性増粘剤との相溶性が悪く、処理液の吐出安定性、記録媒体表面における濡れ性等の両立が難しいことがわかった。 However, it was found that with this technique, the film-forming properties and surface smoothness deteriorated, so that the glossiness of the recorded matter deteriorated, resulting in a matte tone. Further, when the treatment liquid contains a polyvalent metal salt, the compatibility between the polyvalent metal salt and the associative thickener is poor, making it difficult to achieve both ejection stability of the treatment liquid and wettability on the surface of the recording medium. have understood.
特開２０１１－２２５８５９号公報JP 2011-225859 A 特開２００５－３０６０２５号公報JP 2005-306025 A 特開２０２０－７５４３６号公報JP 2020-75436 A 特開２０１８－１６２５号公報JP 2018-1625 A
　本発明は、上記問題・状況に鑑みてなされたものであり、その解決課題は、インクの吐出安定性が良好であり、記録物の画質が向上したインクジェット記録用インクセット、インクジェット記録方法及びインクジェット記録装置を提供することである。 The present invention has been made in view of the above-mentioned problems and circumstances, and the problem to be solved is an ink set for inkjet recording, an inkjet recording method, and an inkjet recording method, in which the ejection stability of the ink is good and the image quality of the recorded matter is improved. It is to provide a recording device.
　本発明者は、上記課題を解決すべく、上記問題の原因等について検討した結果、インク及び処理液を含むインクジェット記録用インクセットにおいて、インクが含有する増粘剤が、色材の過凝集を阻害する機能を有することにより、インクの良好な吐出安定性が得られ、記録物の画質が向上することを見出し本発明に至った。
　すなわち、本発明に係る上記課題は、以下の手段により解決される。 In order to solve the above problems, the present inventors have investigated the causes of the above problems and found that, in an inkjet recording ink set containing an ink and a treatment liquid, the thickener contained in the ink causes excessive aggregation of the coloring material. The present inventors have found that the presence of the inhibiting function provides good ejection stability of the ink and improves the image quality of the recorded matter, leading to the present invention.
That is, the above problems related to the present invention are solved by the following means.
　１．インク及び処理液を含むインクジェット記録用インクセットであって、
　前記インクが、増粘剤、色材、水及び有機溶剤を含有し、
　前記処理液が、凝集剤、水及び有機溶剤を含有し、
　前記増粘剤が、前記色材の過凝集を阻害する機能を有する
　ことを特徴とするインクジェット記録用インクセット。 1. An inkjet recording ink set comprising an ink and a treatment liquid,
The ink contains a thickener, a coloring material, water and an organic solvent,
The treatment liquid contains a flocculant, water and an organic solvent,
The ink set for inkjet recording, wherein the thickener has a function of inhibiting excessive aggregation of the coloring material.
　２．前記インクを組成物Ａとし、
　前記インクのうち、前記増粘剤を除いたものを組成物Ｂとし、
　前記組成物Ａと前記処理液とを混合させたものを組成物Ｃとし、かつ、
　前記組成物Ｂと前記処理液とを混合させたものを組成物Ｄとしたとき、
　前記組成物Ａ及びＢの２５℃におけるせん断速度１０００［１／ｓ］時の粘度ＶＡ及びＶＢ、並びに、前記組成物Ｃ及びＤの２５℃におけるせん断速度２［１／ｓ］時の粘度ＶＣ及びＶＤが、下記関係式（１）及び（２）を満たす
　式（１）：　ＶＡ＞ＶＢ
　式（２）：　ＶＣ≦ＶＤ
　ことを特徴とする第１項に記載のインクジェット記録用インクセット。 2. The ink is composition A,
A composition B is obtained by removing the thickening agent from the ink,
A composition C is obtained by mixing the composition A and the treatment liquid, and
When the composition D is obtained by mixing the composition B and the treatment liquid,
The viscosities V A and V B of the compositions A and B at a shear rate of 1000 [1/s] at 25° C., and the viscosities of the compositions C and D at a shear rate of 2 [1/s] at 25° C. V C and V D satisfy the following relational expressions (1) and (2): Formula (1): V A >V B
Formula (2): V C ≤ V D
2. The ink set for inkjet recording according to item 1, characterized by:
　３．前記組成物Ａの２５℃におけるせん断速度１０００［１／ｓ］時の粘度ＶＡが、１５ｍＰａ・ｓ以下である
　ことを特徴とする第２項に記載のインクジェット記録用インクセット。 3. 3. The ink set for inkjet recording according to item 2, wherein the viscosity VA of the composition A at a shear rate of 1000 [1/s] at 25° C. is 15 mPa·s or less.
　４．前記組成物Ｃ及びＤにおける５μｍ以上の粗大粒子数の割合ＲＣ及びＲＤにおいて、
　下記関係式（３）を満たす
　式（３）：　ＲＣ／ＲＤ＜１
　ことを特徴とする第２項又は第３項のいずれか一項に記載のインクジェット記録用インクセット。 4. In the ratios R C and R D of the number of coarse particles of 5 μm or more in the compositions C and D,
Formula (3) that satisfies the following relational expression (3): R C /R D <1
The ink set for inkjet recording according to any one of items 2 and 3, characterized by:
　５．前記増粘剤の含有量が、前記色材の全質量に対して５～１００質量％の範囲内である
　ことを特徴とする第１項から第４項までのいずれか一項に記載のインクジェット記録用インクセット。 5. 5. The inkjet according to any one of items 1 to 4, wherein the content of the thickening agent is in the range of 5 to 100% by mass with respect to the total mass of the coloring material. Ink set for recording.
　６．前記インクの２５℃におけるチキソトロピック指数が、０．８５～１．０の範囲内である
　ことを特徴とする第１項から第５項までのいずれか一項に記載のインクジェット記録用インクセット。 6. 6. The ink set for inkjet recording according to any one of items 1 to 5, wherein the ink has a thixotropic index at 25° C. in the range of 0.85 to 1.0.
　７．前記増粘剤が、少なくとも同一粒子中に親水部と疎水部とをもつ
　ことを特徴とする第１項から第６項までのいずれか一項に記載のインクジェット記録用インクセット。 7. 7. The ink set for inkjet recording according to any one of items 1 to 6, wherein the thickener has at least a hydrophilic portion and a hydrophobic portion in the same particle.
　８．前記インクにおける前記有機溶剤の含有量が、前記インクの全質量に対して５～２５質量％の範囲内である
　ことを特徴とする第１項から第７項までのいずれか一項に記載のインクジェット記録用インクセット。 8. 8. The method according to any one of items 1 to 7, wherein the content of the organic solvent in the ink is in the range of 5 to 25% by mass with respect to the total mass of the ink. Ink set for inkjet recording.
　９．前記凝集剤が、多価金属塩、カチオン性ポリマー又は有機酸である
　ことを特徴とする第１項から第８項までのいずれか一項に記載のインクジェット記録用インクセット。 9. 9. The ink set for inkjet recording according to any one of items 1 to 8, wherein the aggregating agent is a polyvalent metal salt, a cationic polymer, or an organic acid.
　１０．前記多価金属塩が、少なくともカルシウム塩又はマグネシウム塩を含有する
　ことを特徴とする第９項に記載のインクジェット記録用インクセット。 10. 10. The ink set for inkjet recording according to Item 9, wherein the polyvalent metal salt contains at least a calcium salt or a magnesium salt.
　１１．前記インク及び前記処理液を混合させた組成物の２５℃におけるせん断速度２［１／ｓ］時の粘度ＶＣが、１５ｍＰａ・ｓ以上である
　ことを特徴とする第１項から第１０項までのいずれか一項に記載のインクジェット記録用インクセット。 11. Items 1 to 10, wherein the composition obtained by mixing the ink and the treatment liquid has a viscosity VC of 15 mPa·s or more at a shear rate of 2 [1/s] at 25°C. The ink set for inkjet recording according to any one of .
　１２．インクジェット記録用インクセットを用いるインクジェット記録方法であって、
　第１項から第１１項までのいずれか一項に記載のインクジェット記録用インクセットを用い、
　前記インク及び前記処理液が、記録媒体表面において、液体同士で合一する
　ことを特徴とするインクジェット記録方法。 12. An inkjet recording method using an inkjet recording ink set,
Using the inkjet recording ink set according to any one of items 1 to 11,
An inkjet recording method, wherein the ink and the treatment liquid are combined with each other on the surface of a recording medium.
　１３．前記記録媒体の前記インクの吸収性及び前記インクの付与量に応じて、前記処理液の印字率又は液滴量を変化させる
　ことを特徴とする第１２項に記載のインクジェット記録方法。 13. 13. The inkjet recording method according to Item 12, wherein the printing rate or the amount of droplets of the treatment liquid is changed according to the absorbability of the ink of the recording medium and the amount of the ink applied.
　１４．前記インクジェット記録用インクセットが、千鳥配置されたインクジェットヘッドから吐出される
　ことを特徴とする第１２項又は第１３項に記載のインクジェット記録方法。 14. 14. The inkjet recording method of item 12 or 13, wherein the inkjet recording ink set is ejected from an inkjet head arranged in a staggered manner.
　１５．前記インクジェット記録用インクセットが、循環機構を有するインクジェット記録装置から吐出される
　ことを特徴とする第１２項から第１４項までのいずれか一項に記載のインクジェット記録方法。 15. Item 15. The inkjet recording method according to any one of Items 12 to 14, wherein the ink set for inkjet recording is discharged from an inkjet recording apparatus having a circulation mechanism.
　１６．前記循環機構が、両方向循環である
　ことを特徴とする第１５項に記載のインクジェット記録方法。 16. Item 16. The inkjet recording method of Item 15, wherein the circulation mechanism is bidirectional circulation.
　１７．インクジェット記録用インクセットを用いるインクジェット記録装置であって、
　第１項から第１１項までのいずれか一項に記載のインクジェット記録用インクセットを用い、
　前記インクジェット記録装置が、前記インク用インクジェットヘッド及び前記処理液用インクジェットヘッドを有し、
　前記インク用インクジェットヘッド及び前記処理液用インクジェットヘッドが、同一キャリッジに搭載されている、又は、
　前記インク用インクジェットヘッド及び前記処理液用インクジェットヘッドが、それぞれ別のキャリッジに搭載され、乾燥機構を挟むことなく前記キャリッジが隣接している
　ことを特徴とするインクジェット記録装置。 17. An inkjet recording apparatus using an inkjet recording ink set,
Using the inkjet recording ink set according to any one of items 1 to 11,
The inkjet recording device has the inkjet head for the ink and the inkjet head for the treatment liquid,
The inkjet head for ink and the inkjet head for treatment liquid are mounted on the same carriage, or
An inkjet recording apparatus, wherein the inkjet head for ink and the inkjet head for treatment liquid are mounted on separate carriages, and the carriages are adjacent to each other without a drying mechanism interposed therebetween.
　本発明の上記手段により、インクの吐出安定性が良好であり、記録物の画質が向上したインクジェット記録用インクセット、インクジェット記録方法及びインクジェット記録装置を提供することができる。 By the means of the present invention, it is possible to provide an ink set for ink jet recording, an ink jet recording method and an ink jet recording apparatus with good ink ejection stability and improved image quality of recorded matter.
　本発明の効果の発現機構又は作用機構については、明確にはなっていないが、以下のように推察している。 Although the expression mechanism or action mechanism of the effects of the present invention has not been clarified, it is speculated as follows.
　水性インクは、インクの吸収性の低い・無い記録媒体に記録すると、インクの液滴間のにじみや色ムラが発生する。そのため、インク中の色材を凝集させ、インクの粘度を意図的に上昇させる必要がある。
　そこで、凝集剤を含有する処理液と水性インクを併用することにより、インクの液滴間のにじみや色ムラを抑制できる技術が知られている。 When water-based ink is used for recording on a recording medium with low or no ink absorption, bleeding between ink droplets and color unevenness occur. Therefore, it is necessary to intentionally increase the viscosity of the ink by aggregating the coloring material in the ink.
Therefore, a technique is known in which bleeding between ink droplets and color unevenness can be suppressed by using a treatment liquid containing an aggregating agent in combination with water-based ink.
　また、インク中の色材を、十分に凝集させるためには、ウェット・オン・ウェット方式を用いることが好ましい。液体状態のインクと処理液が記録媒体表面で合一（混合）することにより、インク中の色材と処理液中の凝集剤との接触する機会が増えるため、十分に凝集が進行する。しかし、ウェット・オン・ウェット方式では、場合によっては、凝集剤と色材からなる凝集物の粒径が大きくなりすぎる、すなわち、過凝集が生じやすく、平滑性の低下による光沢性の低下等の画質の低下が問題であった。そのため、ウェット・オン・ウェット方式では、画質の低下が生じない程度に凝集の進行度合いを調整する必要があった。 In addition, it is preferable to use a wet-on-wet method in order to sufficiently agglomerate the coloring material in the ink. The coalescence (mixing) of the liquid ink and the treatment liquid on the surface of the recording medium increases the chances of contact between the coloring material in the ink and the aggregating agent in the treatment liquid, so that aggregation proceeds sufficiently. However, in the wet-on-wet method, in some cases, the particle size of aggregates composed of a flocculant and a coloring material becomes too large, i.e., over-aggregation tends to occur, and smoothness is reduced, resulting in a decrease in glossiness. The problem was the deterioration of image quality. Therefore, in the wet-on-wet method, it is necessary to adjust the progress of aggregation to the extent that image quality does not deteriorate.
　そこで、本発明者が検討を重ねたところ、色材の過凝集を阻害する機能を有する化合物が存在し、さらに、インク中に当該化合物を含有させることにより色材の過凝集を抑制でき、画質が向上することがわかった。また、当該化合物のうち、インク中に含有することによりインクの粘度を上昇させる性質を有するもの（増粘剤）を用いることにより、インクの粘度を吐出安定性が良好となる粘度に調整できることがわかった。 Accordingly, the present inventors conducted extensive studies and found that there exists a compound that has a function of inhibiting excessive aggregation of the coloring material. was found to improve. In addition, among the compounds, by using a compound (thickener) that has the property of increasing the viscosity of the ink when contained in the ink, it is possible to adjust the viscosity of the ink to a viscosity that provides good ejection stability. have understood.
インクジェット記録装置を示す概略図Schematic diagram showing an inkjet recording device キャリッジの底面図Carriage bottom view インク循環系を示す模式図Schematic diagram showing ink circulation system インクジェット記録装置の主要な機能構成を示すブロック図Block diagram showing the main functional configuration of an inkjet printing apparatus
　本発明のインクジェット記録用インクセットは、インク及び処理液を含むインクジェット記録用インクセットであって、前記インクが、増粘剤、色材、水及び有機溶剤を含有し、前記処理液が、凝集剤、水及び有機溶剤を含有し、前記増粘剤が、前記色材の過凝集を阻害する機能を有することを特徴とする。
　この特徴は、下記実施形態に共通する又は対応する技術的特徴である。 The ink set for inkjet recording of the present invention is an ink set for inkjet recording containing an ink and a treatment liquid, wherein the ink contains a thickener, a coloring material, water and an organic solvent, and the treatment liquid aggregates agent, water and an organic solvent, and the thickener has a function of inhibiting overaggregation of the colorant.
This feature is a technical feature common to or corresponding to the following embodiments.
　本発明の実施形態としては、本発明の効果発現の観点から、前記インクを組成物Ａとし、前記インクのうち、前記増粘剤を除いたものを組成物Ｂとし、前記組成物Ａと前記処理液とを混合させたものを組成物Ｃとし、かつ、前記組成物Ｂと前記処理液とを混合させたものを組成物Ｄとしたとき、前記組成物Ａ及びＢの２５℃におけるせん断速度１０００［１／ｓ］時の粘度ＶＡ及びＶＢ、並びに、前記組成物Ｃ及びＤの２５℃におけるせん断速度２［１／ｓ］時の粘度ＶＣ及びＶＤが、下記関係式（１）及び（２）を満たすことが好ましい。
　式（１）：　ＶＡ＞ＶＢ
　式（２）：　ＶＣ≦ＶＤ As an embodiment of the present invention, from the viewpoint of exhibiting the effect of the present invention, the ink is a composition A, the ink excluding the thickener is a composition B, and the composition A and the The shear rate at 25° C. of the compositions A and B when a composition C is obtained by mixing the treatment liquid and a composition D is obtained by mixing the composition B and the treatment liquid The viscosities V A and V B at 1000 [1/s], and the viscosities V C and V D at a shear rate of 2 [1/s] at 25 ° C. of the compositions C and D are expressed by the following relational expression (1 ) and (2) are preferably satisfied.
Formula (1): V A >V B
Formula (2): V C ≤ V D
　吐出安定性の観点から、前記組成物Ａの２５℃におけるせん断速度１０００［１／ｓ］時の粘度ＶＡが、１５ｍＰａ・ｓ以下であることが好ましい。 From the viewpoint of ejection stability, it is preferable that the composition A has a viscosity VA of 15 mPa·s or less at a shear rate of 1000 [1/s] at 25°C.
　また、本発明の効果発現の観点から、前記組成物Ｃ及びＤにおける５μｍ以上の粗大粒子数の割合ＲＣ及びＲＤにおいて、下記関係式（３）を満たすことが好ましい。
　式（３）：　ＲＣ／ＲＤ＜１ Moreover, from the viewpoint of exhibiting the effects of the present invention, it is preferable that the ratios R C and R D of the number of coarse particles of 5 μm or more in the compositions C and D satisfy the following relational expression (3).
Formula (3): R C /R D <1
　過凝集を抑制する観点から、前記増粘剤の含有量が、前記色材の全質量に対して５～１００質量％の範囲内であることが好ましい。 From the viewpoint of suppressing overaggregation, it is preferable that the content of the thickening agent is within the range of 5 to 100% by mass with respect to the total mass of the coloring material.
　吐出安定性の観点から、前記インクの２５℃におけるチキソトロピック指数が、０．８５～１．０の範囲内であることが好ましい。 From the viewpoint of ejection stability, the thixotropic index at 25°C of the ink is preferably in the range of 0.85 to 1.0.
　色材（顔料分散体等）との相互作用の観点から、前記増粘剤が、少なくとも同一粒子中に親水部と疎水部とをもつことが好ましい。 From the viewpoint of interaction with the colorant (pigment dispersion, etc.), it is preferable that the thickener has at least a hydrophilic portion and a hydrophobic portion in the same particle.
　インクの乾燥性の観点から、前記インクにおける前記有機溶剤の含有量が、前記インクの全質量に対して５～２５質量％の範囲内であることが好ましい。 From the viewpoint of the drying property of the ink, it is preferable that the content of the organic solvent in the ink is in the range of 5 to 25% by mass with respect to the total mass of the ink.
　印字品質の観点から、前記凝集剤が、多価金属塩、カチオン性ポリマー又は有機酸であることが好ましく、前記多価金属塩が、少なくともカルシウム塩又はマグネシウム塩を含有することがより好ましい。 From the viewpoint of print quality, the aggregating agent is preferably a polyvalent metal salt, a cationic polymer or an organic acid, and more preferably the polyvalent metal salt contains at least calcium salt or magnesium salt.
　ピニング性の観点から、前記インク及び前記処理液を混合させた組成物の２５℃におけるせん断速度２［１／ｓ］時の粘度ＶＣが、１５ｍＰａ・ｓ以上であることが好ましい。 From the viewpoint of pinning properties, it is preferable that the composition obtained by mixing the ink and the treatment liquid has a viscosity V C at a shear rate of 2 [1/s] at 25° C. of 15 mPa·s or more.
　本発明のインクジェット記録方法は、本発明のインクジェット記録用インクセットを用い、前記インク及び前記処理液が、記録媒体表面において、液体同士で合一することを特徴とする。 The ink jet recording method of the present invention is characterized in that the ink set for ink jet recording of the present invention is used, and the ink and the treatment liquid are united with each other on the surface of the recording medium.
　画質及び乾燥性が向上する観点から、前記記録媒体の前記インクの吸収性及び前記インクの付与量に応じて、前記処理液の印字率又は液滴量を変化させることが好ましく、前記インクジェット記録用インクセットが、千鳥配置されたインクジェットヘッドから吐出されることがより好ましい。 From the viewpoint of improving image quality and drying property, it is preferable to change the printing rate or droplet amount of the treatment liquid according to the absorption of the ink and the amount of the ink applied to the recording medium. More preferably, the ink set is ejected from the staggered inkjet heads.
　吐出安定性の観点から、前記インクジェット記録用インクセットが、循環機構を有するインクジェット記録装置から吐出されることが好ましく、前記循環機構が、両方向循環であることがより好ましい。 From the viewpoint of ejection stability, the ink set for inkjet recording is preferably ejected from an inkjet recording apparatus having a circulation mechanism, and more preferably, the circulation mechanism is bidirectional circulation.
　本発明のインクジェット記録装置は、本発明のインクジェット記録用インクセットを用い、前記インクジェット記録装置が、前記インク用インクジェットヘッド及び前記処理液用インクジェットヘッドを有し、前記インク用インクジェットヘッド及び前記処理液用インクジェットヘッドが、同一キャリッジに搭載されている、又は、前記インク用インクジェットヘッド及び前記処理液用インクジェットヘッドが、それぞれ別のキャリッジに搭載され、乾燥機構を挟むことなく前記キャリッジが隣接していることを特徴とする。 The inkjet recording apparatus of the present invention uses the inkjet recording ink set of the present invention, the inkjet recording apparatus has the inkjet head for the ink and the inkjet head for the treatment liquid, and the inkjet head for the ink and the treatment liquid. The inkjet head for the treatment liquid is mounted on the same carriage, or the inkjet head for the ink and the inkjet head for the treatment liquid are mounted on separate carriages, and the carriages are adjacent to each other without a drying mechanism interposed therebetween. It is characterized by
　以下、本発明とその構成要素、及び本発明を実施するための形態・態様について詳細な説明をする。なお、本願において、「～」は、その前後に記載される数値を下限値及び上限値として含む意味で使用する。 The following is a detailed description of the present invention, its components, and the forms and modes for carrying out the present invention. In the present application, "-" is used to mean that the numerical values before and after it are included as the lower limit and the upper limit.
　≪本発明のインクジェット記録用インクセットの概要≫
　本発明のインクジェット記録用インクセットは、インク及び処理液を含むインクジェット記録用インクセットであって、前記インクが、増粘剤、色材、水及び有機溶剤を含有し、前記処理液が、凝集剤、水及び有機溶剤を含有し、前記増粘剤が、前記色材の過凝集を阻害する機能を有することを特徴とする。 <<Overview of the ink set for inkjet recording of the present invention>>
The ink set for inkjet recording of the present invention is an ink set for inkjet recording containing an ink and a treatment liquid, wherein the ink contains a thickener, a coloring material, water and an organic solvent, and the treatment liquid aggregates agent, water and an organic solvent, and the thickener has a function of inhibiting overaggregation of the colorant.
　本発明に係るインクは、水を含有する水性インクである。水性インクは、溶剤インクと比較してＶＯＣ（volatile organic compounds：揮発性有機化合物）の含有量を比較的少なくすることができるため、環境への負荷を低減できて好ましい。その反面、吸収性の低い・無い記録媒体に記録する場合、インクの液滴間のにじみや色ムラが生じやすい。 The ink according to the present invention is a water-based ink containing water. Water-based inks can have a relatively low VOC (volatile organic compound) content compared to solvent inks, and are therefore preferable because they can reduce the burden on the environment. On the other hand, when recording on a recording medium with low or no absorbency, bleeding between ink droplets and color unevenness are likely to occur.
　そこで、本発明に係るインクと本発明に係る処理液と併用することにより、すなわち、本発明のインクジェット記録用インクセット（以下、単に、「インクセット」ともいう。）を用いることにより、処理液中の凝集剤との反応により、インク中の色材が凝集し、インクと処理液の混合物の粘度が上昇するため、吸収性の低い・無い記録媒体に記録しても、ピニング性が良好であり、インクの液滴間のにじみや色ムラを抑制できる。 Therefore, by using the ink according to the present invention and the treatment liquid according to the present invention together, that is, by using the ink set for inkjet recording of the present invention (hereinafter also simply referred to as "ink set"), the treatment liquid Due to the reaction with the aggregating agent in the ink, the coloring material in the ink agglomerates and the viscosity of the mixture of the ink and treatment liquid increases. It is possible to suppress bleeding and color unevenness between ink droplets.
　しかし、必要以上にインク中の色材が凝集し、凝集物の粒径が大きくなってしまうと、記録媒体表面に着弾したインクの塗膜表面に凹凸が生じてしまい、記録物の画質が低下する。そのため、インクと処理液を併用する方法では、インクの塗膜表面に凹凸が生じない程度に凝集力を調整する必要がある。 However, if the colorant in the ink agglomerates more than necessary and the particle size of the agglomerate increases, the surface of the ink film that lands on the surface of the recording medium becomes uneven, and the image quality of the printed matter deteriorates. do. Therefore, in the method of using both the ink and the treatment liquid, it is necessary to adjust the cohesive force to such an extent that unevenness does not occur on the surface of the coating film of the ink.
　インク中の色材が凝集しすぎることを「過凝集」といい、過凝集を抑制することにより、記録物の良好な画質が得られる。 Excessive aggregation of the coloring material in the ink is called "overaggregation", and by suppressing overaggregation, good image quality can be obtained in the printed matter.
　本発明においては、良好な吐出安定性を得る目的で含有される増粘剤が、さらに、色材の過凝集を阻害する機能を有することにより、色材の過凝集が抑制され、画質を向上させることができる。特に、過凝集が生じやすいウェット・オン・ウェット方式において、その効果は顕著である。 In the present invention, the thickener contained for the purpose of obtaining good ejection stability further has a function of inhibiting overaggregation of the coloring material, thereby suppressing overaggregation of the coloring material and improving image quality. can be made In particular, the effect is remarkable in the wet-on-wet method in which overaggregation tends to occur.
　さらに、過凝集の有無は粘度により判別することができる。具体的には、本発明に係るインク（増粘剤を含む）と処理液を混合させたもの（混合液）の粘度が、当該インクのうち増粘剤を除いたものと処理液を混合させたもの（混合液）の粘度よりも低い、又は、粘度が同じ場合には、過凝集が抑制されていると判別することができる。なお、粘度の測定方法については、後述する。 Furthermore, the presence or absence of excessive aggregation can be determined by viscosity. Specifically, the viscosity of the mixture of the ink according to the present invention (including the thickener) and the treatment liquid (mixed liquid) is such that the ink excluding the thickener is mixed with the treatment liquid. If the viscosity is lower than or equal to that of the other (mixed liquid), it can be determined that excessive aggregation is suppressed. A method for measuring the viscosity will be described later.
　［１　インク］
　本発明に係るインクは、増粘剤、色材、水及び有機溶剤を含有し、増粘剤が、色材の過凝集を阻害する機能を有することを特徴とする。 [1 Ink]
The ink according to the present invention contains a thickener, a coloring material, water and an organic solvent, and is characterized in that the thickening agent has a function of inhibiting excessive aggregation of the coloring material.
　［１．１　インクの構成］
　［１．１．１　増粘剤］
　本発明に係るインクは、増粘剤を含有することにより、インクの粘度を調整することができ、良好な吐出安定性が得られる。また、インクにおける有機溶剤の含有量を低減することができる。さらに、当該増粘剤が、色材の過凝集を阻害する機能を有することにより、色材の過凝集が抑制され、画質を向上させることができる。 [1.1 Configuration of Ink]
[1.1.1 Thickener]
By containing a thickener, the ink according to the present invention can adjust the viscosity of the ink and obtain good ejection stability. Also, the organic solvent content in the ink can be reduced. Furthermore, since the thickener has a function of inhibiting overaggregation of the coloring material, overaggregation of the coloring material is suppressed, and image quality can be improved.
　「増粘剤」とは、添加することにより、液体の粘度を上昇させるもののことをいい、本発明においては、さらに、色材の過凝集を阻害する機能を有するもののことをいう。なお、粘度の測定方法及び測定条件は、特に制限されない。 "Thickening agent" refers to a substance that increases the viscosity of a liquid when added, and in the present invention, further refers to a substance that has the function of inhibiting overaggregation of a coloring material. The method and conditions for measuring viscosity are not particularly limited.
　増粘剤が、色材の過凝集を阻害する機能を有するか否かについては、例えば、本発明に係るインク（増粘剤を含む）と、当該インクのうち増粘剤を除いたものとを、それぞれ処理液に混合させ、混合させたものの粘度や、粗大粒子数の割合を比較することにより、判別することができる。粘度や粗大粒子数の割合の比較方法については、詳しくは後述する。 Whether or not the thickener has a function of inhibiting overaggregation of the coloring material is determined, for example, by comparing the ink (including the thickener) according to the present invention and the ink excluding the thickener. are mixed with the treatment liquid, and the viscosity of the mixture and the ratio of the number of coarse particles are compared. A method for comparing the viscosity and the ratio of the number of coarse particles will be described later in detail.
　増粘剤の種類によって、増粘性の詳細なメカニズムは異なるが、本発明に係るインクは、増粘剤を含有することにより分子間相互作用が働き、あたかも物理的に架橋した巨大分子としてふるまうことによって系の粘度が上昇すると考えられる。そして、この巨大分子中に色材が保持されることにより、凝集剤を含有する処理液と混合させても、色材が凝集しすぎるのを抑制できる。ただし、巨大分子の物理的な架橋構造は分子間相互作用により形成されるため、完全に色材が保持されるのではなく、一部の色材は自由に動くことができ、凝集剤との反応により凝集することが可能である。このため、色材を適度に凝集させることができる。 Although the detailed mechanism of thickening differs depending on the type of thickening agent, the ink according to the present invention behaves as if it were a physically cross-linked macromolecule due to intermolecular interactions caused by containing the thickening agent. It is thought that the viscosity of the system increases due to Since the coloring material is retained in the macromolecules, excessive aggregation of the coloring material can be suppressed even when mixed with a treatment liquid containing an aggregating agent. However, since the physical cross-linked structure of macromolecules is formed by intermolecular interactions, the coloring material is not completely retained, and some coloring materials can move freely, and the flocculant and It is possible to aggregate by reaction. Therefore, the coloring material can be appropriately aggregated.
　したがって、一般的に増粘剤として使用されている化合物以外にも、添加することにより液体の粘度を上昇させ、さらに、色材の過凝集を阻害する機能を有するものであれば、特に制限されず使用できる。本発明に係る増粘剤としては、無機化合物であっても、有機化合物であってもよいが、色材との相互作用の観点から、増粘剤は、有機化合物であることが好ましく、少なくとも同一粒子中に親水部と疎水部とをもつことがより好ましい。 Therefore, in addition to compounds that are generally used as thickeners, any compound that has the function of increasing the viscosity of the liquid and inhibiting overaggregation of the coloring material is particularly limited. can be used without The thickening agent according to the present invention may be an inorganic compound or an organic compound. From the viewpoint of interaction with the coloring material, the thickening agent is preferably an organic compound, and at least It is more preferable to have a hydrophilic part and a hydrophobic part in the same particle.
　ここでの「粒子」とは、分子が集合して形成される集合体のことをいい、分子の種類は全て同じであっても異なっていてもよい。なお、集合体中において、分子同士が化学結合を形成していてもよい。また、「少なくとも、同一粒子中に親水部と疎水部とをもつ」とは、少なくとも、同一集合体において、親水部と疎水部をもっていればよく、親水部をもたない疎水部のみで構成される分子が集合体中に存在してもよい。 "Particles" here refer to aggregates formed by aggregation of molecules, and the types of molecules may all be the same or different. In addition, in the assembly, the molecules may form chemical bonds with each other. Further, "having at least a hydrophilic part and a hydrophobic part in the same particle" means that at least the same aggregate has a hydrophilic part and a hydrophobic part, and is composed only of a hydrophobic part without a hydrophilic part. molecules may be present in the aggregate.
　例えば、親水部を持たない疎水部のみで構成される分子の表面に、乳化剤（界面活性剤）を吸着させることにより、同一粒子中に親水部と疎水部をもつ構成とすることができる。また、親水部と疎水部とを同一分子中にもつ分子のみで集合体を形成してもよい。具体的には、以下で説明する水不溶性樹脂微粒子又は水溶性樹脂であることが好ましい。 For example, by adsorbing an emulsifier (surfactant) to the surface of a molecule that is composed only of hydrophobic moieties that do not have hydrophilic moieties, it is possible to create a structure that has hydrophilic moieties and hydrophobic moieties in the same particle. Alternatively, an aggregate may be formed only by molecules having a hydrophilic portion and a hydrophobic portion in the same molecule. Specifically, water-insoluble resin fine particles or water-soluble resins described below are preferable.
　増粘剤の含有量は、インクの全質量に対して、０．１～５質量％の範囲内であることが好ましい。上記範囲内であることにより、インクの良好な吐出安定性が得られる。
　また、増粘剤の含有量は、色材に対して、５～１００質量％の範囲内であることが好ましい。上記範囲内であることにより、過凝集を十分に抑制することができる。 The content of the thickening agent is preferably in the range of 0.1 to 5% by weight with respect to the total weight of the ink. By being within the above range, good ejection stability of the ink can be obtained.
Also, the content of the thickening agent is preferably in the range of 5 to 100% by mass with respect to the coloring material. By being within the above range, excessive aggregation can be sufficiently suppressed.
　［１．１．１．１　無機化合物］
　無機化合物としては、シリカ（ＳｉＯ２）、アルミナ、チタニア等の無機化合物、及び、ベントナイト、モンモリロナイトのような粘土鉱物が挙げられ、中でも、シリカ粉末、疎水処理したシリカ粉末又はこれらの混合物であることが好ましい。 [1.1.1.1 Inorganic compound]
Examples of inorganic compounds include inorganic compounds such as silica (SiO 2 ), alumina, and titania, and clay minerals such as bentonite and montmorillonite, among which silica powder, hydrophobically treated silica powder, or a mixture thereof. is preferred.
　具体的には、乾式法により微粉化したシリカ微粉末（例えば、アエロジル３００、日本アエロジル社製）、上記シリカ微粉末をトリメチルジシラザンで変性した微粉末（例えば、アエロジルＲＸ３００、日本アエロジル社製）、上記シリカ微粉末をポリジメチルシロキサンで変性した微粉末（例えば、アエロジルＲＹ３００、日本アエロジル社製）などが挙げられる。 Specifically, fine silica powder pulverized by a dry method (for example, Aerosil 300, manufactured by Nippon Aerosil Co., Ltd.), fine powder obtained by modifying the above fine silica powder with trimethyldisilazane (for example, Aerosil RX300, manufactured by Nippon Aerosil Co., Ltd.). and a fine powder obtained by modifying the silica fine powder with polydimethylsiloxane (for example, Aerosil RY300, manufactured by Nippon Aerosil Co., Ltd.).
　また、天然に産する無機鉱物源から作られた合成層状シリケート（ケイ酸塩）であるラポナイト（ビックケミー社製）等が挙げられる。 　In addition, Laponite (manufactured by BYK-Chemie), which is a synthetic layered silicate (silicate) made from naturally occurring inorganic mineral sources, can be mentioned.
　無機化合物の平均粒径は、５～５０μｍの範囲内であることが好ましく、５～１２μｍの範囲内であることがより好ましい。 The average particle size of the inorganic compound is preferably within the range of 5-50 μm, more preferably within the range of 5-12 μm.
　［１．１．１．２　水不溶性樹脂微粒子］
　有機化合物としては、下記の水不溶性樹脂微粒子を用いることができる。なお、水不溶性樹脂微粒子は、少なくとも同一粒子中に親水部と疎水部とをもつことにより、水系媒体中に分散することができる。 [1.1.1.2 Water-insoluble resin microparticles]
As the organic compound, the following water-insoluble resin fine particles can be used. The water-insoluble resin fine particles can be dispersed in an aqueous medium by having at least a hydrophilic portion and a hydrophobic portion in the same particle.
　（樹脂微粒子分散液）
　以下で説明する樹脂微粒子は、水不溶性樹脂微粒子であり、当該水不溶性樹脂微粒子を含む水不溶性樹脂の微粒子分散液は、インクに対して溶解性又は親和性を示す。 (resin fine particle dispersion)
The resin fine particles described below are water-insoluble resin fine particles, and a water-insoluble resin fine particle dispersion containing the water-insoluble resin fine particles exhibits solubility or affinity for ink.
　本発明において、「水不溶性樹脂微粒子」とは、本来水不溶性であるが、ミクロな微粒子として、樹脂が水系媒体中に分散する形態を有するものであり、乳化剤等を用いて強制乳化させ水中に分散している非水溶性樹脂、又は、分子内に親水性の官能基を導入して、乳化剤や分散安定剤を使用することなくそれ自身で安定な水分散体を形成する自己乳化できる非水溶性樹脂である。これらの樹脂は通常、水又は水／アルコール混合溶剤中に乳化分散させた状態で用いられる。 In the present invention, the "water-insoluble resin fine particles" are originally water-insoluble, but have a form in which the resin is dispersed in an aqueous medium as micro fine particles. Dispersed water-insoluble resin, or self-emulsifying water-insoluble water-insoluble resin that forms a stable aqueous dispersion by itself without using an emulsifier or dispersion stabilizer by introducing a hydrophilic functional group into the molecule. It is a flexible resin. These resins are usually used in a state of being emulsified and dispersed in water or a water/alcohol mixed solvent.
　すなわち、水不溶性樹脂（疎水部）に、親水部を導入（乳化剤等を用いて強制乳化、又は、分子内に親水性の官能基を導入）することにより、同一粒子中において、親水部と疎水部とをもつ構成とすることができ、水系媒体中に分散することができる。中でも、同一分子中において親水部と疎水部とをもつ構成、すなわち、分子内に親水性の官能基を導入して、乳化剤や分散安定剤を使用することなくそれ自身で安定な水分散体を形成する自己乳化できる非水溶性樹脂であることが好ましい。 That is, by introducing a hydrophilic portion into a water-insoluble resin (hydrophobic portion) (forced emulsification using an emulsifier or the like, or introducing a hydrophilic functional group into the molecule), the hydrophilic portion and the hydrophobic and can be dispersed in an aqueous medium. Among them, a structure having a hydrophilic portion and a hydrophobic portion in the same molecule, that is, a hydrophilic functional group is introduced into the molecule to form a stable aqueous dispersion by itself without using an emulsifier or a dispersion stabilizer. It is preferably a water-insoluble resin that can self-emulsify to form.
　なお、本発明において、「水不溶性」とは、樹脂を１０５℃で２時間乾燥させた後、２５℃の水１００ｇに溶解させたときに、その溶解量が１０ｇ以下、好ましくは５ｇ以下、更に好ましくは１ｇ以下である樹脂をいう。ただし、樹脂が塩生成基を有する場合、溶解量は、その種類に応じて、樹脂の塩生成基を酢酸又は水酸化ナトリウムで１００％中和したときの溶解量である。 In the present invention, the term “water-insoluble” means that when the resin is dried at 105° C. for 2 hours and then dissolved in 100 g of water at 25° C., the dissolved amount is 10 g or less, preferably 5 g or less, and further Preferably, it refers to a resin weighing 1 g or less. However, when the resin has a salt-forming group, the dissolved amount is the dissolved amount when the salt-forming group of the resin is 100% neutralized with acetic acid or sodium hydroxide, depending on the type.
　樹脂微粒子としては、アクリル樹脂微粒子、ウレタン樹脂微粒子、ポリエステル樹脂微粒子又はウレタン樹脂とアクリル樹脂の複合樹脂微粒子のいずれかであることが好ましい。 The fine resin particles are preferably acrylic resin fine particles, urethane resin fine particles, polyester resin fine particles, or composite resin fine particles of urethane resin and acrylic resin.
　また、樹脂微粒子分散液は、本発明に係る処理液と混合した場合、分散が不安定化して微粒子同士が吸着集合するため、微粒子の粒径が増大する。このときの樹脂微粒子の平均粒径（Ｚ平均粒径）は、１０００ｎｍ以上であることが好ましい。理由は定かではないが、凝集時における平均粒径が１０００ｎｍ以上である樹脂微粒子を使用することにより、色材の過凝集を阻害することができ、記録物の画質が向上する。 In addition, when the resin fine particle dispersion is mixed with the treatment liquid according to the present invention, the dispersion becomes unstable and the fine particles are adsorbed and aggregated to each other, resulting in an increase in the particle size of the fine particles. At this time, the average particle size (Z average particle size) of the fine resin particles is preferably 1000 nm or more. Although the reason is not clear, by using fine resin particles having an average particle diameter of 1000 nm or more when aggregated, overaggregation of the coloring material can be inhibited, and the image quality of the recorded matter is improved.
　なお、微粒子の平均粒径（Ｚ平均粒径）は、粒子径測定装置及び動的光散乱法を利用して以下の手順で測定できる。
　樹脂微粒子を含むスラリーを、樹脂微粒子が０．１質量％になるようイオン交換水で希釈し、希釈スラリーにレーザー光を照射し、樹脂微粒子から散乱される散乱光強度をマイクロ秒単位の時間変化で測定する。検出された樹脂微粒子に起因する散乱強度分布を正規分布に当てはめて、キュムラント解析法により樹脂微粒子のＺ平均粒子径を求める。
　粒子径測定装置としては、例えば、スペクトリス社製ゼータサイザーナノＺＳが挙げられる。粒子径測定装置には、データ解析ソフトが搭載されており、データ解析ソフトが測定データを自動的に解析することでＺ平均粒子径を算出できる。 The average particle size (Z-average particle size) of fine particles can be measured by the following procedure using a particle size measuring device and a dynamic light scattering method.
A slurry containing resin fine particles is diluted with ion-exchanged water so that the resin fine particles are 0.1% by mass, the diluted slurry is irradiated with a laser beam, and the scattered light intensity scattered from the resin fine particles changes over time in microseconds. Measure in The Z-average particle size of the resin fine particles is obtained by applying the scattering intensity distribution caused by the detected resin fine particles to a normal distribution and using the cumulant analysis method.
Examples of the particle size measuring device include Zetasizer Nano ZS manufactured by Spectris. The particle size measuring device is equipped with data analysis software, and the Z-average particle size can be calculated by automatically analyzing the measurement data with the data analysis software.
　また、本発明のインクにおいては、記録媒体への定着性を高める観点から、増粘剤とは別に樹脂を添加してもよい。また、定着樹脂としては、凝集時において、平均粒径（Ｚ平均粒径）が１０００ｎｍ未満の樹脂微粒子を使用することが好ましい。 In addition, in the ink of the present invention, a resin may be added in addition to the thickener from the viewpoint of improving fixability to the recording medium. As the fixing resin, it is preferable to use fine resin particles having an average particle size (Z-average particle size) of less than 1000 nm at the time of aggregation.
　上記ポリエステル樹脂、ウレタン樹脂、アクリル樹脂又はウレタン樹脂とアクリル樹脂の複合樹脂微粒子は、アニオン性又はノニオン性であることが好ましい。 The polyester resin, urethane resin, acrylic resin, or composite resin particles of urethane resin and acrylic resin are preferably anionic or nonionic.
　中でも、樹脂微粒子は、酸構造（親水部）を含有することが好ましい。酸構造を含有することにより、界面活性剤の添加量が少なくても、水中に分散することが可能となる。これを、自己乳化型といい、界面活性剤を使用すること無く分子イオン性のみで、水中に樹脂微粒子が分散安定化しうることを意味する。酸構造の例には、カルボキシ基（－ＣＯＯＨ）、スルホン酸基（－ＳＯ３Ｈ）等の酸基等が含まれる。酸構造は、樹脂において側鎖に存在していてもよく、末端に存在していてもよい。
　ただし、増粘剤とは別に定着性を高める観点で樹脂微粒子を用いる場合（詳しくは後述する。）には、必ずしも酸構造を必要とせず、酸構造を有していても有していなくてもよい。 Among them, the resin fine particles preferably contain an acid structure (hydrophilic portion). By containing an acid structure, it becomes possible to disperse in water even if the added amount of the surfactant is small. This is called a self-emulsifying type, which means that fine resin particles can be dispersed and stabilized in water only with molecular ionic properties without using a surfactant. Examples of acid structures include acid groups such as a carboxy group (--COOH) and a sulfonic acid group (--SO 3 H). The acid structure may be present in the side chain of the resin, or may be present at the end.
However, when resin fine particles are used from the standpoint of improving the fixability separately from the thickener (details will be described later), the acid structure is not necessarily required, and the acid structure may or may not be present. good too.
　上記酸構造の一部又は全部は、中和されていることが好ましい。酸構造を中和することにより、樹脂の水分散性を向上させることができる。酸構造を中和する中和剤の例としては、有機アミン類であることが好ましく、トリメチルアミン、トリエチルアミン、トリプロピルアミン、トリブチルアミン、Ｎ－メチルジエタノールアミン、トリエタノールアミン等が挙げられる。 A part or all of the acid structure is preferably neutralized. By neutralizing the acid structure, the water dispersibility of the resin can be improved. Examples of the neutralizing agent that neutralizes the acid structure are preferably organic amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, N-methyldiethanolamine, and triethanolamine.
　また、樹脂微粒子のガラス転移点（Ｔｇ）は、－３０～１００℃の範囲内であることが好ましい。
　前記ガラス転移点（Ｔｇ）は、ＤＳＣ（示差走査熱量測定装置）を用いて－３０～２００℃の温度域で昇温速度１０℃／分の条件で昇温させたときの吸熱ピークから、ガラス転移温度Ｔｇを読み取ることによって特定することができる。 Further, the glass transition point (Tg) of the fine resin particles is preferably in the range of -30 to 100°C.
The glass transition point (Tg) is determined from the endothermic peak when the temperature is raised in the temperature range of −30 to 200° C. at a temperature elevation rate of 10° C./min using a DSC (differential scanning calorimeter). It can be identified by reading the transition temperature Tg.
　以下、各樹脂について説明する。
　（ポリエステル樹脂）
　水不溶性樹脂微粒子としてのポリエステル骨格を有するポリエステル樹脂は、多価アルコール成分と多価カルボン酸、多価カルボン酸無水物、多価カルボン酸エステル等の多価カルボン酸成分とを用いて得ることができる。 Each resin will be described below.
(polyester resin)
A polyester resin having a polyester skeleton as water-insoluble resin fine particles can be obtained by using a polyhydric alcohol component and a polycarboxylic acid component such as a polycarboxylic acid, a polycarboxylic anhydride, or a polycarboxylic acid ester. can.
　多価アルコール成分としては、２価のアルコール（ジオール）、具体的には炭素数２～３６の範囲内のアルキレングリコール（エチレングリコール、１，２－プロピレングリコール、１，３－プロピレングリコール、１，４－ブチレングリコール、１，６－ヘキサンジオール等）、炭素数４～３６の範囲内のアルキレンエーテルグリコール（ジエチレングリコール、トリエチレングリコール、ジプロピレングリコール、ポリエチレングリコール、ポリプロピレングリコール、ポリブチレングリコール等）、炭素数６～３６の範囲内の脂環式ジオール（１，４－シクロヘキサンジメタノール、水素添加ビスフェノールＡ等）、前記脂環式ジオールの炭素数２～４の範囲内のアルキレンオキシド（エチレンオキシド（以下、ＥＯと略記する。）、プロピレンオキシド（以下、ＰＯと略記する。）、ブチレンオキシド（以下、ＢＯと略記する。））付加物（付加モル数１～３０の範囲）ビスフェノール類（ビスフェノールＡ、ビスフェノールＦ、ビスフェノールＳ等）の炭素数２～４の範囲内のアルキレンオキシド（ＥＯ、ＰＯ、ＢＯ等）付加物（付加モル数２～３０の範囲）等が挙げられる。これらは、一種類のみを単独で使用してもよいし、二種類以上を併用してもよい。 As the polyhydric alcohol component, a dihydric alcohol (diol), specifically an alkylene glycol having 2 to 36 carbon atoms (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1, 4-butylene glycol, 1,6-hexanediol, etc.), alkylene ether glycols having 4 to 36 carbon atoms (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polybutylene glycol, etc.), carbon Alicyclic diols having numbers 6 to 36 (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.), alkylene oxides having 2 to 4 carbon atoms in the alicyclic diols (ethylene oxide (hereinafter referred to as EO), propylene oxide (hereinafter abbreviated as PO), butylene oxide (hereinafter abbreviated as BO)) adduct (addition mole number range of 1 to 30) bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.) and alkylene oxides having 2 to 4 carbon atoms (EO, PO, BO, etc.) adducts (addition mole number in the range of 2 to 30). These may be used alone or in combination of two or more.
　多価カルボン酸成分としては、２価のカルボン酸（ジカルボン酸）、具体的には炭素数４～３６の範囲内のアルカンジカルボン酸（コハク酸、アピジン酸、セバシン酸等）、アルケニルコハク酸（ドデセニルコハク酸等）、炭素数４～３６の範囲内の脂環式ジカルボン酸（ダイマー酸（２量化リノール酸）等）、炭素数４～３６の範囲内のアルケンジカルボン酸（マレイン酸、フマル酸、シトラコン酸、メサコン酸等）、炭素数８～３６の範囲内の芳香族ジカルボン酸（フタル酸、イソフタル酸、テレフタル酸又はこれらの誘導体、ナフタレンジカルボン酸等）等が挙げられる。これらは、一種類のみを単独で使用してもよいし、二種類以上を併用してもよい。 Examples of polycarboxylic acid components include divalent carboxylic acids (dicarboxylic acids), specifically alkanedicarboxylic acids having 4 to 36 carbon atoms (succinic acid, apidic acid, sebacic acid, etc.), alkenylsuccinic acids ( dodecenyl succinic acid, etc.), alicyclic dicarboxylic acids having 4 to 36 carbon atoms (dimer acid (dimerized linoleic acid), etc.), alkenedicarboxylic acids having 4 to 36 carbon atoms (maleic acid, fumaric acid, citraconic acid, mesaconic acid, etc.), aromatic dicarboxylic acids having 8 to 36 carbon atoms (phthalic acid, isophthalic acid, terephthalic acid or derivatives thereof, naphthalenedicarboxylic acid, etc.). These may be used alone or in combination of two or more.
　ポリエステル樹脂の数平均分子量としては、１０００～５００００の範囲内が好ましく、２０００～２００００の範囲内であることがより好ましい。 The number average molecular weight of the polyester resin is preferably within the range of 1,000 to 50,000, more preferably within the range of 2,000 to 20,000.
　ポリエステル樹脂としては、市販品を使用してもよく、例えば、ペスレジンＡ－１１０Ｆ、Ａ－６４０、Ａ－６４７ＧＥＸ（以上、高松油脂社製）、バイロナール（登録商標）ＭＤ－１１００、ＭＤ－１２００、ＭＤ－１３３５、ＭＤ－１４８０、ＭＤ－１９３０、ＭＤ－２０００（以上、東洋紡社製）、Ｚ－１１００（互応化学社製）等が挙げられる。これらは、一種類のみを単独で使用してもよいし、二種類以上を併用してもよい。 As the polyester resin, commercially available products may be used. MD-1335, MD-1480, MD-1930, MD-2000 (manufactured by Toyobo Co., Ltd.), Z-1100 (manufactured by Goo Chemical Co., Ltd.) and the like. These may be used alone or in combination of two or more.
　（ウレタン樹脂）
　水不溶性樹脂微粒子としてのウレタン樹脂としては、親水基を有するものを用いることができる。 (urethane resin)
A urethane resin having a hydrophilic group can be used as the water-insoluble resin fine particles.
　ウレタン樹脂は、その分子内に水溶性官能基を有する自己乳化型ウレタンを分散させた水分散体、又は界面活性剤を併用して強力な機械剪断力の下で乳化した強制乳化型ウレタンの水分散体であることが好ましい。上記水分散体におけるウレタン樹脂は、ポリオールと有機ポリイソシアネート及び親水基含有化合物との反応により得ることができる。 Urethane resin is an aqueous dispersion of self-emulsifying urethane that has a water-soluble functional group in its molecule, or a forced emulsifying urethane water that is emulsified under strong mechanical shearing force using a surfactant in combination. A dispersion is preferred. The urethane resin in the aqueous dispersion can be obtained by reacting a polyol with an organic polyisocyanate and a hydrophilic group-containing compound.
　上記ウレタン樹脂の水分散体の調製に使用し得るポリオールの例としては、ポリエステルポリオール、ポリエーテルポリオール、ポリカーボネートポリオール、ポリオレフィン系ポリオール等が挙げられる。 Examples of polyols that can be used for preparing the aqueous dispersion of the urethane resin include polyester polyols, polyether polyols, polycarbonate polyols, and polyolefin polyols.
　ポリエステルポリオールの例としては、エチレングリコール、ジエチレングリコール、トリエチレングリコール、１，２－及び１，３－プロピレングリコール、ネオペンチルグリコール、１，３－及び１，４－ブタンジオール、３－メチルペンタンジオール、ヘキサメチレングリコール、１，８－オクタンジオール、２－メチル－１，３－プロパンジオール、ビスフェノールＡ、水添ビスフェノールＡ、トリメチロールプロパン、シクロヘキサンジメタノール等の低分子ポリオール；コハク酸、グルタル酸、アジピン酸、セバシン酸、フタル酸、イソフタル酸、テレフタル酸、トリメリット酸、テトラヒドロフラン酸、エンドメチンテトラヒドロフラン酸、ヘキサヒドロフタル酸などの多価カルボン酸との縮合物等が挙げられる。 Examples of polyester polyols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2- and 1,3-propylene glycol, neopentyl glycol, 1,3- and 1,4-butanediol, 3-methylpentanediol, Low-molecular-weight polyols such as hexamethylene glycol, 1,8-octanediol, 2-methyl-1,3-propanediol, bisphenol A, hydrogenated bisphenol A, trimethylolpropane, cyclohexanedimethanol; succinic acid, glutaric acid, adipine acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, tetrahydrofuranic acid, endomethinetetrahydrofuranic acid, condensates with polyvalent carboxylic acids such as hexahydrophthalic acid, and the like.
　ポリエーテルポリオールの例としては、ポリエチレングリコール、ポリプロピレングリコール、ポリエチレンポリテトラメチレングリコール、ポリプロピレンポリテトレメチレングリコール、ポリテトラメチレングリコール等が挙げられる。 Examples of polyether polyols include polyethylene glycol, polypropylene glycol, polyethylene polytetramethylene glycol, polypropylene polytetramethylene glycol, and polytetramethylene glycol.
　ポリカーボネートポリオールの例としては、ジフェニルカーボネート、ジメチルカーボネート又はホスゲン等の炭酸誘導体と、ジオールとの反応により得ることができる。上記ジオールの例としては、エチレングリコール、ジエチレングリコール、トリエチレングリコール、１，２－及び１，３－プロピレングリコール、ネオペンチルグリコール、１，３－及び１，４－ブタンジオール、３－メチルペンタンジオール、ヘキサメチレングリコール、１，８－オクタンジオール、２－メチル－１，３－プロパンジオール、ビスフェノールＡ、水添ビスフェノールＡ、トリメチロールプロパン、シクロヘキサンジメタノール等が挙げられる。 Examples of polycarbonate polyols can be obtained by reacting carbonic acid derivatives such as diphenyl carbonate, dimethyl carbonate or phosgene with diols. Examples of such diols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2- and 1,3-propylene glycol, neopentyl glycol, 1,3- and 1,4-butanediol, 3-methylpentanediol, hexamethylene glycol, 1,8-octanediol, 2-methyl-1,3-propanediol, bisphenol A, hydrogenated bisphenol A, trimethylolpropane, cyclohexanedimethanol and the like.
　また、ウレタン樹脂の水分散体の調製に使用し得る有機ポリイソシアネートの例としては、トリレンジイソシアネート（ＴＤＩ）、ジフェニルメタンジイソシアネート（ＭＤＩ）、ポリメリックＭＤＩ、キシリレンジイソシアネート（ＸＤＩ）、テトラメチルキシリレンジイソシアネート（ＴＭＸＤＩ）などの芳香族イソシアネート；ヘキサメチレンジイソシアネート（ＨＭＤＩ）などの脂肪族イソシアネート；イソホロンジイソシアネート（ＩＰＤＩ）、４，４’－ジシクロヘキシルメタンジイソシアネート（水素添加ＭＤＩ、Ｈ１２ＭＤＩ）などの脂環族イソシアネートが挙げられる。これらは、一種類のみを単独で使用してもよく、二種類以上を併用してもよい。 Examples of organic polyisocyanates that can be used for preparing aqueous dispersions of urethane resins include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymeric MDI, xylylene diisocyanate (XDI), and tetramethylxylylene diisocyanate. aromatic isocyanates such as (TMXDI); aliphatic isocyanates such as hexamethylene diisocyanate (HMDI); be done. These may be used alone or in combination of two or more.
　また、ウレタン樹脂の水分散体の調製に使用し得る親水基含有化合物の例としては、２，２－ジメチロールプロピオン酸、２，２－ジメチロールブタン酸、２，２－ジメチロール酪酸、２，２－ジメチロール吉草酸、グリシンなどのカルボン酸含有化合物、及びそのナトリウム塩、カリウム塩、アミン塩などの誘導体；タウリン（すなわち、アミノエチルスルホン酸）、エトキシポリエチレングリコールスルホン酸などのスルホン酸含有化合物、及びそのナトリウム塩、カリウム塩、アミン塩等の誘導体が挙げられる。 Examples of hydrophilic group-containing compounds that can be used in the preparation of aqueous dispersions of urethane resins include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolbutyric acid, Carboxylic acid-containing compounds such as 2-dimethylolvaleric acid, glycine, and derivatives thereof such as sodium salts, potassium salts, amine salts; and derivatives thereof such as sodium salts, potassium salts and amine salts.
　ウレタン樹脂は、公知の方法により得ることができる。例えば、上記ポリオールと有機ポリイソシアネートと、親水基含有化合物とを混合し、３０～１３０℃、３０分～５０時間の範囲内で反応させることにより、ウレタンプレポリマーを得ることができる。 A urethane resin can be obtained by a known method. For example, a urethane prepolymer can be obtained by mixing the polyol, organic polyisocyanate, and hydrophilic group-containing compound and reacting them at 30 to 130° C. for 30 minutes to 50 hours.
　ウレタンプレポリマーは、鎖伸長剤により伸長してポリマー化することで、親水基を有するウレタン樹脂となる。鎖伸長剤としては、水及び／又はアミン化合物であることが好ましい。鎖伸長剤として水やアミン化合物を用いることにより、遊離イソシアネートと短時間で反応して、イソシアネート末端プレポリマーを効率よく伸長させることができる。 The urethane prepolymer becomes a urethane resin with hydrophilic groups by extending it with a chain extender and polymerizing it. The chain extender is preferably water and/or an amine compound. By using water or an amine compound as a chain extender, the isocyanate-terminated prepolymer can be efficiently extended by reacting with free isocyanate in a short period of time.
　アミン化合物の例としては、エチレンジアミン、トリエチレンジアミンなどの脂肪族ポリアミン；メタキシレンジアミン、トルイレンジアミンなどの芳香族ポリアミン；ヒドラジン、アジピン酸ジヒドラジド等のポリヒドラジノ化合物等が挙げられる。上記アミン化合物には、上記ポリアミンとともに、ポリマー化を大きく阻害しない程度で、ジブチルアミンなどの１価のアミンやメチルエチルケトオキシム等を反応停止剤として含んでいてもよい。 Examples of amine compounds include aliphatic polyamines such as ethylenediamine and triethylenediamine; aromatic polyamines such as metaxylenediamine and toluylenediamine; and polyhydrazino compounds such as hydrazine and adipic acid dihydrazide. The amine compound may contain, together with the polyamine, a monovalent amine such as dibutylamine, methyl ethyl ketoxime, or the like as a reaction terminator, to the extent that polymerization is not greatly hindered.
　なお、ウレタンプレポリマーの合成においては、イソシアネートと不活性であり、ウレタンプレポリマーを溶解し得る溶剤を用いてもよい。これらの溶剤の例としては、ジオキサン、メチルエチルケトン、ジメチルホルムアミド、テトラヒドロフラン、Ｎ－メチル－２－ピロリドン、トルエン、及びプロピレングリコールモノメチルエーテルアセテート等が挙げられる。反応段階で使用されるこれらの親水性有機溶剤は、最終的に除去されるのが好ましい。 In the synthesis of the urethane prepolymer, a solvent that is inert with isocyanate and capable of dissolving the urethane prepolymer may be used. Examples of these solvents include dioxane, methyl ethyl ketone, dimethylformamide, tetrahydrofuran, N-methyl-2-pyrrolidone, toluene, propylene glycol monomethyl ether acetate, and the like. These hydrophilic organic solvents used in the reaction step are preferably finally removed.
　また、ウレタンプレポリマーの合成においては、反応を促進させるために、アミン触媒（例えば、トリエチルアミン、Ｎ－エチルモルフォリン、トリエチルジアミン等）、スズ系触媒（例えば、ジブチルスズジラウレート、ジオクチルスズジラウレート、オクチル酸スズ等）、チタン系触媒（例えば、テトラブチルチタネート等）等の触媒を添加してもよい。 In the synthesis of urethane prepolymers, amine catalysts (e.g., triethylamine, N-ethylmorpholine, triethyldiamine, etc.), tin-based catalysts (e.g., dibutyltin dilaurate, dioctyltin dilaurate, octylic acid) are used to promote the reaction. Tin, etc.), titanium-based catalysts (eg, tetrabutyl titanate, etc.) may be added.
　ウレタン樹脂の数平均分子量は、分岐構造や内部架橋構造を導入して可能な限り大きくすることが好ましく、数平均分子量５００００～１０００００００であることが好ましい。上記範囲内であることにより、ウレタン樹脂が溶剤に溶けにくくなり、耐候性及び耐水性に優れた塗膜が得られる。なお、数平均分子量（Ｍｎ）は、ゲル浸透クロマトグラフィー（ＧＰＣ）で測定される値であり、例えば、株式会社島津製作所製「ＲＩＤ－６Ａ」（カラム：東ソー株式会社製「ＴＳＫ－ＧＥＬ」、溶剤：テトラヒドロフラン（ＴＨＦ）、カラム温度：４０℃）を用いて、ポリスチレン標準試料で作成した検量線から求めることができる。 The number average molecular weight of the urethane resin is preferably increased as much as possible by introducing a branched structure or an internal crosslinked structure, and is preferably from 50,000 to 1,000,000. Within the above range, the urethane resin becomes difficult to dissolve in a solvent, and a coating film excellent in weather resistance and water resistance can be obtained. The number average molecular weight (Mn) is a value measured by gel permeation chromatography (GPC). Solvent: tetrahydrofuran (THF), column temperature: 40° C.) can be determined from a calibration curve prepared from polystyrene standard samples.
　また、ウレタン樹脂は市販品を用いてもよく、例えば、ＷＢＲ－０１６Ｕ（大成ファインケミカル社製）、スーパーフレックス（登録商標）６２０、６５０、５００Ｍ、Ｅ－２０００（以上、第一工業製薬社製）、パーマリン（登録商標）ＵＣ－２０（三洋化成工業社製）、パラサーフＵＰ－２２（大原パラヂウム化学社製）等が挙げられる。 In addition, commercially available urethane resins may be used, such as WBR-016U (manufactured by Taisei Fine Chemical Co., Ltd.), Superflex (registered trademark) 620, 650, 500M, E-2000 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). , Permaline (registered trademark) UC-20 (manufactured by Sanyo Chemical Industries, Ltd.), Parasurf UP-22 (manufactured by Ohara Palladium Chemical Co., Ltd.), and the like.
　（アクリル樹脂）
　アクリル樹脂は、アクリル酸エステル成分、メタクリル酸エステル成分、スチレン成分等との共重合体を用いて得ることができる。
　アクリル酸エステル成分及びメタクリル酸エステル成分の例としては、（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸プロピル、（メタ）アクリル酸ブル、（メタ）アクリル酸－２－ヒドロキシエチル、（メタ）アクリル酸－２－ヒドロキシプロピル、（メタ）アクリル酸－４－ヒドロキブチル、（メタ）アクリル酸シクロヘキシル、（メタ）アクリル酸テトラヒドロフルフリル、（メタ）アクリル酸イソボルニル、（メタ）アクリル酸ベンジル、（メタ）アクリル酸－２－ヒドロキシブチル、（メタ）アクリル酸ベンジル、（メタ）アクリル酸グリシジル、（メタ）アクリル酸、ジ（メタ）アクリル酸（ジ）エチレングリコール、ジ（メタ）アクリル酸－１，４－ブタンジオ－ル、ジ（メタ）アクリル酸－１，６－ヘキサンジオ－ル、トリ（メタ）アクリル酸トリメチロ－ルプロパン、ジ（メタ）アクリル酸グリセリン、（メタ）アクリル酸－２－エチルヘキシル、（メタ）アクリル酸ラウリル、（メタ）アクリル酸ステアリル、アクリルアミド等が挙げられる。 (acrylic resin)
The acrylic resin can be obtained by using a copolymer with an acrylic acid ester component, a methacrylic acid ester component, a styrene component, or the like.
Examples of acrylic acid ester components and methacrylic acid ester components include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, blue (meth) acrylate, and (meth) acrylic acid-2- Hydroxyethyl, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, (meth)acrylate ) benzyl acrylate, 2-hydroxybutyl (meth)acrylate, benzyl (meth)acrylate, glycidyl (meth)acrylate, (meth)acrylic acid, (di)ethylene glycol di(meth)acrylate, di ( 1,4-butanediol meth)acrylate, 1,6-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, glyceryl di(meth)acrylate, (meth)acrylic acid-2-ethylhexyl, lauryl (meth)acrylate, stearyl (meth)acrylate, acrylamide and the like.
　スチレン成分の例としては、スチレン、４－メチルスチレン、４－ヒドロキシスチレン、４－アセトキシスチレン、４－アセチルスチレン、スチレンスルホン酸等が挙げられる。これらの成分は、一種類のみを単独で使用してもよく、二種類以上を併用してもよい。 Examples of styrene components include styrene, 4-methylstyrene, 4-hydroxystyrene, 4-acetoxystyrene, 4-acetylstyrene and styrenesulfonic acid. These components may be used alone or in combination of two or more.
　アクリル樹脂の数平均分子量（Ｍｎ）は、１０００～５００００であることが好ましく、２０００～２００００であることがより好ましい。アクリル樹脂の数平均分子量（Ｍｎ）が１０００以上であると、塗膜の凝集力が強くなり、密着性が向上し、５００００以下であると、有機溶剤に対する溶解性が良く、乳化分散体の粒子径の微小化が促進される。 The number average molecular weight (Mn) of the acrylic resin is preferably 1,000 to 50,000, more preferably 2,000 to 20,000. When the number average molecular weight (Mn) of the acrylic resin is 1000 or more, the cohesive force of the coating film becomes strong and the adhesion is improved. Miniaturization of the diameter is promoted.
　なお、数平均分子量（Ｍｗ）は、ゲル浸透クロマトグラフィー（ＧＰＣ）で測定される値であり、例えば、株式会社島津製作所製「ＲＩＤ－６Ａ」（カラム：東ソー株式会社製「ＴＳＫ－ＧＥＬ」、溶剤：テトラヒドロフラン（ＴＨＦ）、カラム温度：４０℃）を用いて、ポリスチレン標準試料で作成した検量線から求めることができる。 The number average molecular weight (Mw) is a value measured by gel permeation chromatography (GPC). Solvent: tetrahydrofuran (THF), column temperature: 40° C.) can be determined from a calibration curve prepared from polystyrene standard samples.
　また、アクリル樹脂としては、市販品を用いてもよく、例えば、モビニール（登録商標）６７６３（ジャパンコーティングレジン社製）、ＲＫＷ－６２０、ＵＷ－３１９ＳＸ、ＵＷ－６００、ＵＷ－５５０ＣＳ（以上、大成ファインケミカル社製）、２６８２、２６８０、２６８４、２６８５、２６８７（以上、日信化学工業社製）などのアクリル系エマルジョン等が挙げられる。 In addition, as the acrylic resin, a commercially available product may be used. Fine Chemical Co., Ltd.), 2682, 2680, 2684, 2685, 2687 (manufactured by Nissin Kagaku Kogyo Co., Ltd.).
　（複合樹脂微粒子）
　樹脂微粒子は、複合樹脂微粒子であってもよく、アクリル樹脂をウレタン樹脂により乳化させてなる複合樹脂微粒子であることが好ましい。すなわち、アクリル樹脂から構成される内部層、及びウレタン樹脂から構成される表面層を有する複合樹脂微粒子であることが好ましい。 (Composite resin particles)
The fine resin particles may be fine composite resin particles, and are preferably fine composite resin particles obtained by emulsifying an acrylic resin with a urethane resin. That is, it is preferable that the fine composite resin particles have an inner layer made of an acrylic resin and a surface layer made of a urethane resin.
　ここで、ウレタン樹脂は、水不溶性樹脂微粒子としてのアクリル樹脂と連続相である水との界面に存在して、水不溶性樹脂微粒子を保護する樹脂と異なる水不溶性樹脂微粒子層として機能する。 Here, the urethane resin exists at the interface between the acrylic resin as the water-insoluble resin fine particles and the water as the continuous phase, and functions as a water-insoluble resin fine particle layer different from the resin that protects the water-insoluble resin fine particles.
　このようにアクリル樹脂をウレタン樹脂により乳化させてなる複合樹脂微粒子とすることで、アクリル樹脂の単独での使用と異なり、ウレタン樹脂や顔料凝集剤との相溶性の低下を抑制することができる。また、アクリル樹脂とウレタン樹脂とをそれぞれ乳化させて混合するのと比べて、画像（塗膜）の物性を向上させることができるとともに、インクの安定性も改善することができる。 By forming composite resin fine particles obtained by emulsifying acrylic resin with urethane resin in this way, unlike using acrylic resin alone, it is possible to suppress deterioration in compatibility with urethane resin and pigment flocculant. In addition, the physical properties of the image (coating film) can be improved, and the stability of the ink can also be improved, compared to emulsifying and mixing the acrylic resin and the urethane resin respectively.
　アクリル樹脂をウレタン樹脂により乳化させてなる複合樹脂微粒子において、ウレタン樹脂（Ｕ）とアクリル樹脂（Ａ）との質量比率の値（Ｕ／Ａ）は、４０／６０～９５／５の範囲内であることが好ましい。ウレタン樹脂（Ｕ）の存在割合が上記範囲内であると、分散剤との相溶性が向上し、耐溶剤性も向上する。また、アクリル樹脂（Ａ）の存在割合が上記範囲内であると、アクリル系フィルムに対する密着性に優れる。上記存在割合において、ウレタン樹脂（Ｕ）とアクリル樹脂（Ａ）との質量比率の値（Ｕ／Ａ）は、４０／６０～８０／２０の範囲内であることが好ましい。 In the composite resin fine particles obtained by emulsifying an acrylic resin with a urethane resin, the mass ratio (U/A) between the urethane resin (U) and the acrylic resin (A) is in the range of 40/60 to 95/5. Preferably. When the content of the urethane resin (U) is within the above range, the compatibility with the dispersant is improved, and the solvent resistance is also improved. Moreover, when the abundance of the acrylic resin (A) is within the above range, the adhesiveness to the acrylic film is excellent. In the above proportions, the mass ratio (U/A) between the urethane resin (U) and the acrylic resin (A) is preferably in the range of 40/60 to 80/20.
　複合樹脂微粒子中におけるアクリル樹脂とウレタン樹脂とを合わせた合計の樹脂の含有量は、特に制限されないが、複合樹脂微粒子の全質量に対して、５．０質量％以上であることが好ましく、１０．０～７０．０質量％の範囲内であることがより好ましい。上記範囲内であることにより、記録媒体とインクとの良好な定着性が得られる。 The total resin content of the acrylic resin and the urethane resin in the composite resin fine particles is not particularly limited, but is preferably 5.0% by mass or more relative to the total mass of the composite resin fine particles. It is more preferably within the range of 0.0 to 70.0% by mass. Within the above range, good fixability between the recording medium and the ink can be obtained.
　また、ウレタン樹脂によるアクリル樹脂の乳化においては、ウレタン樹脂とともに、乳化剤として作用する界面活性剤を用いることができる。乳化剤を添加することにより、複合樹脂微粒子の貯蔵安定性を向上させることができる。 Also, in emulsifying the acrylic resin with the urethane resin, a surfactant that acts as an emulsifier can be used together with the urethane resin. By adding an emulsifier, the storage stability of the fine composite resin particles can be improved.
　乳化剤としては、アニオン性界面活性剤又はノニオン性界面活性剤を用いることができ、本発明においては、両方を用いることがより好ましい。乳化剤（界面活性剤）の含有量は、アクリル樹脂とウレタン樹脂とを合わせた合計の樹脂の全質量に対して、１．０～２０．０質量％の範囲内であることが好ましい。上記範囲内であることにより、耐水性及び耐溶剤性を向上できる。 An anionic surfactant or a nonionic surfactant can be used as an emulsifier, and both are more preferably used in the present invention. The content of the emulsifier (surfactant) is preferably in the range of 1.0 to 20.0% by mass with respect to the total mass of the total resin including the acrylic resin and the urethane resin. By being within the above range, water resistance and solvent resistance can be improved.
　また、アニオン性界面活性剤（Ｘ）とノニオン性界面活性剤（Ｙ）との含有質量比（Ｘ／Ｙ）の値は、１００／０～５０／５０の範囲内であることが好ましい。上記範囲内であることにより、乳化性やインクの貯蔵安定性をより向上できる。 Also, the content mass ratio (X/Y) between the anionic surfactant (X) and the nonionic surfactant (Y) is preferably within the range of 100/0 to 50/50. By being within the above range, the emulsifiability and the storage stability of the ink can be further improved.
　アニオン性界面活性剤の例としては、アルキル硫酸塩、ポリオキシエチレンアルキルエーテル硫酸塩、スルホコハク酸塩、アルファオレフィンスルホン酸塩、Ｎ－アシルアミノ酸塩、カルボン酸塩、リン酸エステル等が挙げられる。中でも、スルホコハク酸塩又はアルファオレフィンスルホン酸塩であることが好ましい。
　また、塩の種類の例としては、特に制限されないが、ナトリウム塩、カリウム塩、マグネシウム塩などの金属塩、トリエタノールアミン塩等が挙げられる。 Examples of anionic surfactants include alkyl sulfates, polyoxyethylene alkyl ether sulfates, sulfosuccinates, alpha olefin sulfonates, N-acyl amino acid salts, carboxylates, phosphate esters, and the like. Among them, sulfosuccinate or alpha olefin sulfonate is preferred.
Examples of the salt type include, but are not particularly limited to, metal salts such as sodium salts, potassium salts and magnesium salts, and triethanolamine salts.
　ノニオン性界面活性剤の例としては、ポリオキシエチレンアルキルエーテル類、ポリオキシエチレンアルキルフェニルエーテル類、ポリオキシエチレンアルキルアミンエーテル、ポリオキシエチレン脂肪酸エステル、ソルビタン脂肪酸エステル、ショ糖脂肪酸エステル等が挙げられる。中でも、ポリオキシエチレンアルキルエーテル類、又は、ポリオキシエチレンアルキルフェニルエーテル類であることが好ましい。 Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkylamine ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, and the like. . Among them, polyoxyethylene alkyl ethers or polyoxyethylene alkylphenyl ethers are preferable.
　樹脂微粒子の平均粒径は、増粘剤として用いる場合には、１０００ｎｍ以上であることが好ましい。また、記録媒体への定着性を高める観点から、増粘剤とは別に定着樹脂として当該樹脂微粒子を用いる場合には、平均粒径が１０～５００ｎｍの範囲内であることが好ましく、１０～３００ｎｍの範囲内であることがより好ましく、１０～２００ｎｍの範囲内であることが更に好ましい。平均粒径の測定は、前述のとおり、動的光散乱法、電気泳動法等を用いた市販の粒径測定機器により求めることができるが、動的光散乱法による測定が簡便で、かつ当該粒子径領域を精度よく測定できる。
　定着性を高める観点で当該樹脂微粒子を用いる場合には、必ずしも酸構造を必要とせず、酸構造を有していても有していなくてもよい。 The average particle size of the fine resin particles is preferably 1000 nm or more when used as a thickening agent. Further, from the viewpoint of improving the fixability to the recording medium, when the fine resin particles are used as a fixing resin separately from the thickening agent, the average particle size is preferably in the range of 10 to 500 nm, more preferably 10 to 300 nm. more preferably within the range of 10 to 200 nm. As described above, the average particle size can be measured by a commercially available particle size measuring instrument using a dynamic light scattering method, an electrophoresis method, or the like. The particle size range can be measured with high accuracy.
When the fine resin particles are used from the viewpoint of improving fixability, the acid structure is not necessarily required, and the acid structure may or may not be present.
　定着性を高める観点から、本発明に係るインクに用いられる樹脂微粒子の市販品の例を以下に挙げる。
　（ポリエステル樹脂）
　ペスレジンＡ－１１０Ｆ、Ａ－５２０、Ａ－６１３Ｄ、Ａ－６１５ＧＥ、Ａ－６４０、Ａ－６４５ＧＨ、Ａ－６４７ＧＥＸ（以上、高松油脂社製）、バイロナール（登録商標）ＭＤ－１２００、１４８０、２０００（以上、東洋紡社製）、エリーテル（登録商標）ＫＡ－５０３４、ＫＡ－５０７１Ｓ、ＫＡ－１４４９、ＫＡ－０１３４、ＫＡ－３５５６、ＫＡ－６１３７、ＫＺＡ－６０３４、ＫＴ－８８０３、ＫＴ－８７０１、ＫＴ－９２０４、ＫＴ－８９０４、ＫＴ－０５０７、ＫＴ－９５１１（以上、ユニチカ社製） Examples of commercially available resin fine particles used in the ink according to the present invention are listed below from the viewpoint of improving fixability.
(polyester resin)
Pesresin A-110F, A-520, A-613D, A-615GE, A-640, A-645GH, A-647GEX (manufactured by Takamatsu Oil Co., Ltd.), Vylonal (registered trademark) MD-1200, 1480, 2000 ( Above, manufactured by Toyobo), Elitel (registered trademark) KA-5034, KA-5071S, KA-1449, KA-0134, KA-3556, KA-6137, KZA-6034, KT-8803, KT-8701, KT- 9204, KT-8904, KT-0507, KT-9511 (manufactured by Unitika Ltd.)
　（ウレタン樹脂）
　ＮｅｏＲｅｚ（登録商標）Ｒ－９６７、Ｒ－６００、Ｒ－９６７１（以上、楠本化成社製）、Ｗ－６０６１、Ｗ－５６６１、ＷＳ－４０００（以上、三井化学社製）、エバファノール（登録商標）ＨＡ－５６０（日華化学社製） (urethane resin)
NeoRez (registered trademark) R-967, R-600, R-9671 (manufactured by Kusumoto Kasei Co., Ltd.), W-6061, W-5661, WS-4000 (manufactured by Mitsui Chemicals, Inc.), Evafanol (registered trademark) HA-560 (manufactured by Nicca Chemical Co., Ltd.)
　（アクリル樹脂）
　モビニール（登録商標）６７６３、６８９９Ｄ、６９６９Ｄ、６８００、６８１０（以上、ジャパンコーティングレジン社製）、ＴＯＣＲＹＬ（登録商標）Ｗ－７１４６、Ｗ－７１５０、Ｗ－７１５２（以上、トーヨーケム社製） (acrylic resin)
Movinyl (registered trademark) 6763, 6899D, 6969D, 6800, 6810 (manufactured by Japan Coating Resin Co., Ltd.), TOCRYL (registered trademark) W-7146, W-7150, W-7152 (manufactured by Toyochem)
　［１．１．１．３　水溶性樹脂］
　有機化合物としては、下記の水溶性樹脂を用いることができる。なお、水溶性樹脂は、同一分子中に親水部と疎水部とをもつことにより、水系媒体中に分散することができる。 [1.1.1.3 Water-soluble resin]
As the organic compound, the following water-soluble resins can be used. A water-soluble resin can be dispersed in an aqueous medium by having a hydrophilic portion and a hydrophobic portion in the same molecule.
　水溶性樹脂の例としては、ポリビニルアルコール、ポリビニルピロリドン、ポリアクリル酸、ポリアクリル酸ナトリウム、ヒドロキシセルロース、カルボキシメチルセルロース、ポリエチレングリコール等が挙げられる。これらは、一種類のみを単独で用いてもよいし、二種類以上を併用してもよい。 Examples of water-soluble resins include polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, sodium polyacrylate, hydroxycellulose, carboxymethylcellulose, and polyethylene glycol. These may be used alone or in combination of two or more.
　水溶性樹脂としては、市販品を用いることができ、ジョンクリル（登録商標）ＪＤＸ－６５００（ＢＡＳＦ社製）等が挙げられる。また、特開２０１１－９４０８２号公報に記載の共重合樹脂を用いてもよい。 Commercially available products can be used as the water-soluble resin, such as Joncryl (registered trademark) JDX-6500 (manufactured by BASF). Copolymer resins described in JP-A-2011-94082 may also be used.
　［１．１．１．４　その他］
　本発明に係る増粘剤としては、上記の他に一般的に使用される増粘剤が使用でき、例えば、会合型増粘剤が挙げられる。会合型増粘剤は、市販品を用いてもよく、例えばＢＹＫ（登録商標）－４２５（ビックケミー社製）等が挙げられる。 [1.1.1.4 Others]
As the thickener according to the present invention, commonly used thickeners other than those mentioned above can be used, and examples thereof include associative thickeners. Commercially available products such as BYK (registered trademark)-425 (manufactured by BYK-Chemie) can be used as the associative thickener.
　また、本発明に係る増粘剤としては、一般的に顔料分散剤として使用される樹脂も使用できる。顔料分散剤は、市販品を用いてもよく、例えばＤｉｓｐｅｒｂｙｋ１９０、１９３（以上、ビックケミー社製）等が挙げられる。 In addition, resins that are generally used as pigment dispersants can also be used as the thickener according to the present invention. A commercial product may be used as the pigment dispersant, and examples thereof include Disperbyk 190 and 193 (manufactured by BYK-Chemie).
　［１．１．２　色材］
　本発明に係るインクは、色材を含有することにより、記録媒体表面に画像を形成することができる。
　色材としては、着色できるものであれば特に制限されず、染料及び顔料が挙げられるが、吸収性の低い・無い記録媒体に画像を形成する観点から、顔料であることが好ましい。 [1.1.2 Colorant]
The ink according to the present invention can form an image on the surface of a recording medium by containing a coloring material.
The coloring material is not particularly limited as long as it can be colored, and includes dyes and pigments. Pigments are preferred from the viewpoint of forming images on recording media with low or no absorption.
　顔料としては、アニオン性の分散顔料、例えば、表面にアニオン性基を有する自己分散性顔料や、アニオン性の高分子分散剤により分散された顔料、表面をアニオン性の樹脂で被覆されて分散された顔料等を用いることが好ましい。 Examples of pigments include anionic dispersed pigments, such as self-dispersing pigments having anionic groups on the surface, pigments dispersed with an anionic polymer dispersant, and pigments dispersed by coating the surface with an anionic resin. It is preferable to use a pigment or the like.
　アニオン性の分散顔料としては、特に制限されず、公知のものを使用でき、例えば、酸化チタン等の無機顔料、及び、不溶性顔料、レーキ顔料等の有機顔料が挙げられる。
　なお、「レーキ顔料」とは、水に可溶性の染料をレーキ化剤（沈殿剤）で沈殿させて不溶性にした顔料のことをいう。 The anionic dispersed pigment is not particularly limited, and known ones can be used. Examples thereof include inorganic pigments such as titanium oxide, and organic pigments such as insoluble pigments and lake pigments.
The term "lake pigment" refers to a pigment that is made insoluble by precipitating a water-soluble dye with a lake agent (precipitant).
　酸化チタンには、アナターゼ型、ルチル型及びブルーカイト型の三つの結晶形態があるが、汎用なものとしてはアナターゼ型とルチル型に大別できる。特に制限されないが、屈折率が大きく隠蔽性が高いルチル型であることが好ましい。 　Titanium oxide has three crystal forms: anatase, rutile, and brookite. General-purpose forms can be roughly divided into anatase and rutile. Although it is not particularly limited, it is preferably a rutile type having a high refractive index and high hiding power.
　酸化チタンとしては、市販品を用いることができ、ＴＲシリーズ（商品名、富士チタン工業社製）、ＪＲシリーズ（商品名、テイカ社製）やタイペーク（登録商標）（商品名、石原産業社製）などが挙げられる。 As titanium oxide, commercially available products can be used, such as TR series (trade name, manufactured by Fuji Titanium Industry Co., Ltd.), JR series (trade name, manufactured by Tayca), and Typaque (registered trademark) (trade name, manufactured by Ishihara Sangyo Co., Ltd.). ) and the like.
　不溶性顔料としては、特に制限されないが、例えば、アゾ、アゾメチン、メチン、ジフェニルメタン、トリフェニルメタン、キナクリドン、アントラキノン、ペリレン、インジゴ、キノフタロン、イソインドリノン、イソインドリン、アジン、オキサジン、チアジン、ジオキサジン、チアゾール、フタロシアニン、ジケトピロロピロール等が挙げられる。 Examples of insoluble pigments include, but are not limited to, azo, azomethine, methine, diphenylmethane, triphenylmethane, quinacridone, anthraquinone, perylene, indigo, quinophthalone, isoindolinone, isoindoline, azine, oxazine, thiazine, dioxazine, and thiazole. , phthalocyanines, diketopyrrolopyrroles and the like.
　本発明において、好ましく用いられる有機顔料の例としては、以下のものが挙げられる。 Examples of organic pigments preferably used in the present invention include the following.
　マゼンタ又はレッド用の顔料としては、例えば、Ｃ．Ｉ．ピグメントレッド２、Ｃ．Ｉ．ピグメントレッド３、Ｃ．Ｉ．ピグメントレッド５、Ｃ．Ｉ．ピグメントレッド６、Ｃ．Ｉ．ピグメントレッド７、Ｃ．Ｉ．ピグメントレッド１５、Ｃ．Ｉ．ピグメントレッド１６、Ｃ．Ｉ．ピグメントレッド４８：１、Ｃ．Ｉ．ピグメントレッド５３：１、Ｃ．Ｉ．ピグメントレッド５７：１、Ｃ．Ｉ．ピグメントレッド１２２、Ｃ．Ｉ．ピグメントレッド１２３、Ｃ．Ｉ．ピグメントレッド１３９、Ｃ．Ｉ．ピグメントレッド１４４、Ｃ．Ｉ．ピグメントレッド１４９、Ｃ．Ｉ．ピグメントレッド１６６、Ｃ．Ｉ．ピグメントレッド１７７、Ｃ．Ｉ．ピグメントレッド１７８、Ｃ．Ｉ．ピグメントレッド２０２、Ｃ．Ｉ．ピグメントレッド２２２、Ｃ．Ｉ．ピグメントバイオレット１９等が挙げられる。 As pigments for magenta or red, for example, C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I. I. Pigment Red 7, C.I. I. Pigment Red 15, C.I. I. Pigment Red 16, C.I. I. Pigment Red 48:1, C.I. I. Pigment Red 53:1, C.I. I. Pigment Red 57:1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 123, C.I. I. Pigment Red 139, C.I. I. Pigment Red 144, C.I. I. Pigment Red 149, C.I. I. Pigment Red 166, C.I. I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I. Pigment Red 202, C.I. I. Pigment Red 222, C.I. I. Pigment Violet 19 and the like.
　オレンジ又はイエロー用の顔料としては、例えば、Ｃ．Ｉ．ピグメントオレンジ３１、Ｃ．Ｉ．ピグメントオレンジ４３、Ｃ．Ｉ．ピグメントイエロー１２、Ｃ．Ｉ．ピグメントイエロー１３、Ｃ．Ｉ．ピグメントイエロー１４、Ｃ．Ｉ．ピグメントイエロー１５、 Ｃ．Ｉ．ピグメントイエロー１５：３、Ｃ．Ｉ．ピグメントイエロー１７、Ｃ．Ｉ．ピグメントイエロー７４、Ｃ．Ｉ．ピグメントイエロー９３、Ｃ．Ｉ．ピグメントイエロー１２８、Ｃ．Ｉ．ピグメントイエロー９４、Ｃ．Ｉ．ピグメントイエロー１３８、Ｃ．Ｉ．ピグメントイエロー１５５等が挙げられる。特に、色調と耐光性のバランスにおいて、Ｃ．Ｉ．ピグメントイエロー１５５であることが好ましい。 As pigments for orange or yellow, for example, C.I. I. Pigment Orange 31, C.I. I. Pigment Orange 43, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I. I. Pigment Yellow 15:3, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 74, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 128, C.I. I. Pigment Yellow 94, C.I. I. Pigment Yellow 138, C.I. I. Pigment Yellow 155 and the like. In particular, C.I. I. Pigment Yellow 155 is preferred.
　グリーン又はシアン用の顔料としては、例えば、Ｃ．Ｉ．ピグメントブルー１５、Ｃ．Ｉ．ピグメントブルー１５：２、Ｃ．Ｉ．ピグメントブルー１５：３、Ｃ．Ｉ．ピグメントブルー１６、Ｃ．Ｉ．ピグメントブルー６０、Ｃ．Ｉ．ピグメントグリーン７等が挙げられる。 As pigments for green or cyan, for example, C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15:2, C.I. I. Pigment Blue 15:3, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 60, C.I. I. Pigment Green 7 and the like.
　また、ブラック用の顔料としては、例えば、Ｃ．Ｉ．ピグメントブラック１、Ｃ．Ｉ．ピグメントブラック６、Ｃ．Ｉ．ピグメントブラック７等が挙げられる。 Also, as black pigments, for example, C.I. I. Pigment Black 1, C.I. I. Pigment Black 6, C.I. I. Pigment Black 7 and the like.
　（顔料分散剤）
　上記顔料を分散させるために用いられる顔料分散剤は、特に制限されないが、アニオン性基を有する高分子分散剤であることが好ましく、さらに、分子量が５０００～２０００００の範囲内であることが好ましい。 (Pigment dispersant)
The pigment dispersant used to disperse the pigment is not particularly limited, but is preferably a polymeric dispersant having an anionic group, and further preferably has a molecular weight within the range of 5000 to 200000.
　高分子分散剤の例としては、スチレン、スチレン誘導体、ビニルナフタレン誘導体、アクリル酸、アクリル酸誘導体、マレイン酸、マレイン酸誘導体、イタコン酸、イタコン酸誘導体、フマル酸、フマル酸誘導体から選ばれた２種以上の単量体に由来する構造を有するブロック共重合体、ランダム共重合体及びこれらの塩、ポリオキシアルキレン、ポリオキシアルキレンアルキルエーテル等が挙げられる。 Examples of polymeric dispersants include 2 selected from styrene, styrene derivatives, vinylnaphthalene derivatives, acrylic acid, acrylic acid derivatives, maleic acid, maleic acid derivatives, itaconic acid, itaconic acid derivatives, fumaric acid, and fumaric acid derivatives. Block copolymers, random copolymers and salts thereof, polyoxyalkylenes, polyoxyalkylene alkyl ethers, etc., having structures derived from more than one kind of monomers are included.
　高分子分散剤は、アクリロイル基を有することが好ましく、中和塩基で中和して添加することが好ましい。中和塩基としては、特に制限されないが、アンモニア、モノエタノールアミン、ジエタノールアミン、トリエタノールアミン、モルホリン等の有機塩基であることが好ましい。特に、顔料として酸化チタンを用いる場合、アクリロイル基を有する高分子分散剤で酸化チタンを分散させることが好ましい。 The polymer dispersant preferably has an acryloyl group and is preferably added after being neutralized with a neutralizing base. The neutralizing base is not particularly limited, but is preferably an organic base such as ammonia, monoethanolamine, diethanolamine, triethanolamine, morpholine and the like. In particular, when titanium oxide is used as the pigment, it is preferable to disperse the titanium oxide with a polymer dispersant having an acryloyl group.
　インクにおける高分子分散剤の含有量は、顔料の全質量に対して、１０～１００質量％の範囲内であることが好ましく、１０～４０質量％の範囲内であることがより好ましい。 The content of the polymeric dispersant in the ink is preferably in the range of 10 to 100% by mass, more preferably in the range of 10 to 40% by mass, relative to the total mass of the pigment.
　顔料の形態としては、上記高分子分散剤で上記顔料を被覆した、いわゆるカプセル顔料を使用してもよい。高分子分散剤で顔料を被覆する方法としては、公知の方法を用いることができるが、例えば、転相乳化法、酸析法、又は、顔料を重合性界面活性剤により分散し、そこへモノマーを供給し、重合しながら被覆する方法等が挙げられる。 As for the form of the pigment, a so-called capsule pigment in which the pigment is coated with the polymer dispersant may be used. As a method for coating the pigment with the polymer dispersant, known methods can be used. and a method of coating while polymerizing.
　特に好ましい方法としては、以下の方法が挙げられる。
　水に不溶性の樹脂を、メチルエチルケトンなどの有機溶剤に溶解し、塩基にて当該樹脂中の酸性基を部分的又は完全に中和した後、顔料及びイオン交換水を添加し、顔料を分散させる。そして、有機溶剤を除去し、必要に応じて加水し、顔料分散液を調製する。 Particularly preferred methods include the following methods.
A water-insoluble resin is dissolved in an organic solvent such as methyl ethyl ketone, and the acidic groups in the resin are partially or completely neutralized with a base. Then, a pigment and deionized water are added to disperse the pigment. Then, the organic solvent is removed, water is added as necessary, and a pigment dispersion is prepared.
　インク中における顔料の分散状態における平均粒径は、５０ｎｍ以上、３００ｎｍ未満であることが好ましい。上記範囲内であることにより、顔料の分散安定性を向上でき、インクの保存安定性を向上できる。顔料の粒子径は、動的光散乱法、電気泳動法等を用いた市販の粒径測定機器により求めることができるが、動的光散乱法による測定が、簡便で、かつ、当該粒子径領域を精度よく測定できる。 The average particle size of the pigment in the dispersed state in the ink is preferably 50 nm or more and less than 300 nm. Within the above range, the dispersion stability of the pigment can be improved, and the storage stability of the ink can be improved. The particle size of the pigment can be determined by a commercially available particle size measuring instrument using a dynamic light scattering method, an electrophoresis method, etc., but the measurement by the dynamic light scattering method is simple and can be measured with high accuracy.
　顔料は、分散剤及びその他目的に応じて必要な添加剤とともに、分散機により分散させることができる。 The pigment can be dispersed with a dispersing machine together with a dispersant and other additives required according to the purpose.
　分散機としては、公知のものを使用でき、例えば、ボールミル、サンドミル、ラインミル、高圧ホモジナイザー等が挙げられる。中でも、サンドミルによって顔料を分散させると、粒度分布がシャープとなるため好ましい。また、サンドミル分散に使用されるビーズの材質は、特に制限されないが、ビーズ破片の生成やイオン成分のコンタミネーションを防止する観点から、ジルコニア又はジルコンであることが好ましい。また、ビーズ径は、０．３～３ｍｍの範囲内であることが好ましい。 As the disperser, a known one can be used, and examples include ball mills, sand mills, line mills, high-pressure homogenizers, and the like. Among them, it is preferable to disperse the pigment by a sand mill because the particle size distribution becomes sharp. The material of the beads used for sand mill dispersion is not particularly limited, but zirconia or zircon is preferable from the viewpoint of preventing the generation of bead fragments and contamination with ionic components. Also, the bead diameter is preferably within the range of 0.3 to 3 mm.
　インクにおける顔料の含有量は、特に制限されないが、インクの全質量に対して、酸化チタンについては、７～１８質量％の範囲内であることが好ましく、有機顔料については０．５～７質量％の範囲内であることが好ましい。 The content of the pigment in the ink is not particularly limited, but it is preferably in the range of 7 to 18% by mass for titanium oxide and 0.5 to 7% by mass for the organic pigment relative to the total mass of the ink. % is preferred.
　［１．１．３　水］
　本発明に係るインクは、水を含有する。水性インクとすることにより、溶剤インクと比較して、ＶＯＣ（volatile organic compounds：揮発性有機化合物）等の有機溶剤の含有量を低減することができる。水は、特に制限されず、イオン交換水、蒸留水、又は純水であり得る。
　インクにおける水の含有量は、インクの全質量に対して、４０～９０質量％の範囲内であることが好ましい。 [1.1.3 Water]
The ink according to the invention contains water. By using water-based ink, the content of organic solvents such as VOCs (volatile organic compounds) can be reduced compared to solvent ink. Water is not particularly limited, and may be ion-exchanged water, distilled water, or pure water.
The water content in the ink is preferably in the range of 40 to 90% by weight with respect to the total weight of the ink.
　［１．１．４　有機溶剤］
　本発明に係るインクは、有機溶剤を含有することにより、記録媒体におけるインクの濡れ性及びインクの保湿性を向上させることができる。また、水性インクは、水を主溶媒として構成されているため、安定吐出に必要な粘度に調製するのが困難である。そのため、増粘目的でも有機溶剤が使用されるが、環境への負荷の低減及び乾燥性の観点から、ＶＯＣ含有量を３０質量％以下に抑えることが望ましい。ただし、本発明においては、上記増粘剤を含有することにより、有機溶剤の含有量を低減することができ、インクの乾燥性が向上する。 [1.1.4 Organic solvent]
By containing an organic solvent, the ink according to the present invention can improve the wettability of the ink and the moisture retaining property of the ink on the recording medium. In addition, since the water-based ink is composed of water as the main solvent, it is difficult to adjust the viscosity to be required for stable ejection. Therefore, an organic solvent is used also for the purpose of thickening, but it is desirable to suppress the VOC content to 30% by mass or less from the viewpoint of reducing the burden on the environment and drying property. However, in the present invention, the content of the organic solvent can be reduced by containing the thickener, and the drying property of the ink is improved.
　インクにおける有機溶剤の含有量は、特に制限されないが、インクの全質量に対して、５～２５質量％の範囲内であることが好ましい。５質量％以上であることにより、ヘッドノズルにおけるインクの詰まりやインクの泡立ちを抑制できる。 The content of the organic solvent in the ink is not particularly limited, but is preferably within the range of 5 to 25% by mass with respect to the total mass of the ink. When the amount is 5% by mass or more, it is possible to suppress ink clogging and ink bubbling in head nozzles.
　有機溶剤としては、水溶性の有機溶剤であることが好ましく、例えば、アルコール類、多価アルコール類、アミン類、アミド類、グリコールエーテル類、炭素数が４以上である１，２－アルカンジオール類などが挙げられる。 The organic solvent is preferably a water-soluble organic solvent such as alcohols, polyhydric alcohols, amines, amides, glycol ethers, and 1,2-alkanediols having 4 or more carbon atoms. etc.
　アルコール類としては、例えば、メタノール、エタノール、１－プロパノール、２－プロパノール、１－ブタノール、２－ブタノール、２－メチル－１－プロパノール、ｔ－ブタノール、３－メトキシ－１－ブタノール、３－メトキシ－３－メチルブタノール、１－オクタノール、２－オクタノール、ｎ－ノニルアルコール、トリデシルアルコール、ｎ－ウンデシルアルコール、ステアリルアルコール、オレイルアルコール、ベンジルアルコール等が挙げられる。 Alcohols include, for example, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, t-butanol, 3-methoxy-1-butanol, 3-methoxy -3-methylbutanol, 1-octanol, 2-octanol, n-nonyl alcohol, tridecyl alcohol, n-undecyl alcohol, stearyl alcohol, oleyl alcohol, benzyl alcohol and the like.
　多価アルコール類としては、例えば、エチレングリコール、ジエチレングリコール、トリエチレングリコール、テトラエチレングリコール、エチレンオキサイド基の数が５以上のポリエチレングリコール、プロピレングリコール、ジプロピレングリコール、トリプロピレングリコール、プロピレンオキサイド基の数が４以上のポリプロピレングリコール、ブチレングリコール、ヘキサンジオール、ペンタンジオール、グリセリン、ヘキサントリオール、チオジグリコール等が挙げられる。 Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol having 5 or more ethylene oxide groups, propylene glycol, dipropylene glycol, tripropylene glycol, and the number of propylene oxide groups. are 4 or more, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol, and the like.
　アミン類としては、例えば、エタノールアミン、ジエタノールアミン、トリエタノールアミン、Ｎ－メチルジエタノールアミン、Ｎ－エチルジエタノールアミン、モルホリン、Ｎ－エチルモルホリン、エチレンジアミン、ジエチレンジアミン、トリエチレンテトラミン、テトラエチレンペンタミン、ポリエチレンイミン、ペンタメチルジエチレントリアミン、テトラメチルプロピレンジアミン等が挙げられる。 Examples of amines include ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine, pentamethyldiethylenetriamine, tetramethylpropylenediamine, and the like.
　アミド類としては、例えば、ホルムアミド、Ｎ，Ｎ－ジメチルホルムアミド、Ｎ，Ｎ－ジメチルアセトアミド等が挙げられる。 Examples of amides include formamide, N,N-dimethylformamide, N,N-dimethylacetamide and the like.
　グリコールエーテル類としては、例えば、エチレングリコールモノエチルエーテル、エチレングリコールモノブチルエーテル、ジエチレングリコールモノエチルエーテル、ジエチレングリコールモノブチルエーテル、トリエチレングリコールモノブチルエーテル、プロピレングリコールモノプロピルエーテル、ジプロピレングリコールモノメチルエーテル、トリプロピレングリコールモノメチルエーテル等が挙げられる。 Examples of glycol ethers include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, and tripropylene glycol monomethyl. ether and the like.
　炭素数が４以上である１，２－アルカンジオール類としては、例えば、１，２－ブタンジオール、１，２－ペンタンジオール、１，２－ヘキサンジオール、１，２－ヘプタンジオール等が挙げられる。 Examples of 1,2-alkanediols having 4 or more carbon atoms include 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, and 1,2-heptanediol. .
　高速プリント時の滲みを抑制できる観点から、有機溶剤は多価アルコール類であることが好ましく、中でも、エチレングリコール、ジエチレングリコール、トリエチレングリコール、テトラエチレングリコール、プロピレングリコール、ジプロピレングリコール、トリプロピレングリコールであることが好ましい。
　これらの有機溶剤は、一種類のみを単独で用いてもよく、二種類以上を併用してもよい。 From the viewpoint of suppressing bleeding during high-speed printing, the organic solvent is preferably a polyhydric alcohol, especially ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol. Preferably.
These organic solvents may be used alone or in combination of two or more.
　［１．１．５　樹脂］
　本発明に係るインクは、更に樹脂を含有していてもよい。樹脂を含有することにより、記録媒体への定着性を高めることができる。 [1.1.5 Resin]
The ink according to the invention may further contain a resin. By containing a resin, fixability to a recording medium can be improved.
　定着性を高める定着樹脂としては、特に制限されず、例えば、塩化ビニル系樹脂、（メタ）アクリル系樹脂、ウレタン系樹脂、ポリエーテル系樹脂、ポリエステル系樹脂等が挙げられる。 The fixation resin that enhances the fixability is not particularly limited, and examples thereof include vinyl chloride resins, (meth)acrylic resins, urethane resins, polyether resins, and polyester resins.
　また、前述の水不溶性樹脂微粒子を定着樹脂として含有させてもよい。この場合、樹脂微粒子の平均粒径は、１０～５００ｎｍの範囲内であることが好ましく、１０～３００ｎｍの範囲内であることがより好ましく、１０～２００ｎｍの範囲内であることが更に好ましい。 Further, the water-insoluble resin fine particles described above may be contained as a fixing resin. In this case, the average particle diameter of the fine resin particles is preferably in the range of 10 to 500 nm, more preferably in the range of 10 to 300 nm, even more preferably in the range of 10 to 200 nm.
　インクにおける樹脂の含有量は、インクの全質量に対して、２～１５質量％の範囲内であることが好ましい。 The resin content in the ink is preferably in the range of 2 to 15% by mass with respect to the total mass of the ink.
　［１．１．６　添加剤］
　本発明に係るインクは、吐出安定性、プリントヘッドやインクカートリッジ適合性、保存安定性、画像保存性等、その他の目的に応じて、公知の各種添加剤を含有してもよい。 [1.1.6 Additives]
The ink according to the present invention may contain various known additives according to other purposes such as ejection stability, compatibility with print heads and ink cartridges, storage stability, and image storage stability.
　添加剤としては、例えば、界面活性剤が挙げられる。界面活性剤を添加することにより、インクの吐出安定性の向上、及び、記録媒体に着弾したインクの液滴の広がり（ドット径）を制御することができる。 Additives include, for example, surfactants. By adding a surfactant, it is possible to improve the ejection stability of the ink and to control the spread (dot diameter) of the ink droplets that have landed on the recording medium.
　界面活性剤は、特に制限されないが、インクの構成成分にアニオン性の化合物が含まれる場合は、界面活性剤のイオン性はアニオン性、ノニオン性（「非イオン」ともいう。）又は両性のいずれであってもよく、両性イオン界面活性剤としては、ベタイン型であることが好ましい。 The surfactant is not particularly limited, but when an anionic compound is included in the constituents of the ink, the ionicity of the surfactant may be anionic, nonionic (also referred to as "nonionic"), or amphoteric. and the amphoteric ionic surfactant is preferably a betaine type.
　本発明では、アニオン性の界面活性剤にアルカリ成分が含まれると、定着樹脂として含まれる樹脂微粒子が凝集しやすくなり、定着性が低下するため、界面活性剤はノニオン性であることが好ましい。 In the present invention, if the anionic surfactant contains an alkaline component, the fine resin particles contained as the fixing resin tend to agglomerate and the fixability decreases, so the surfactant is preferably nonionic.
　界面活性剤としては、静的な表面張力の低下能が高いフッ素系又はシリコーン系界面活性剤や、動的な表面張力の低下能が高いジオクチルスルホサクシネートなどのアニオン性界面活性剤、比較的低分子量のポリオキシエチレンアルキルエーテル、ポリオキシエチレンアルキルフェニルエーテル、アセチレングリコール類、プルロニック（登録商標）型界面活性剤、ソルビタン誘導体などのノニオン性界面活性剤であることが好ましい。なお、静的な表面張力の低下能が高い界面活性剤と、動的な表面張力の低下能が高い界面活性剤を併用して用いてもよい。 Surfactants include fluorine-based or silicone-based surfactants with high static surface tension lowering ability, anionic surfactants such as dioctyl sulfosuccinate with high dynamic surface tension lowering ability, relatively Nonionic surfactants such as low-molecular-weight polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, acetylene glycols, Pluronic (registered trademark) type surfactants, and sorbitan derivatives are preferred. A surfactant having a high static surface tension lowering ability and a surfactant having a high dynamic surface tension lowering ability may be used in combination.
　インクにおける界面活性剤の含有量は、特に制限されないが、インクの全質量に対して、０．１～５．０質量％の範囲内であることが好ましい。 The content of the surfactant in the ink is not particularly limited, but is preferably within the range of 0.1 to 5.0% by mass with respect to the total mass of the ink.
　本発明に係るインクにおいては、上記界面活性剤以外に、必要に応じて、公知の各種添加剤、例えば、多糖類、粘度調整剤、比抵抗調整剤、皮膜形成剤、紫外線吸収剤、酸化防止剤、退色防止剤、防ばい剤、防錆剤等を適宜選択して用いることができ、例えば、流動パラフィン、ジオクチルフタレート、トリクレジルホスフェート、シリコーンオイル等の油滴微粒子、特開昭５７－７４１９３号公報、同５７－８７９８８号公報、同６２－２６１４７６号公報等に記載の紫外線吸収剤、特開昭５７－７４１９２号公報、同５７－８７９８９号公報、同６０－７２７８５号公報、同６１－１４６５９１号公報、特開平１－９５０９１号公報、同３－１３３７６号公報等に記載の退色防止剤、特開昭５９－４２９９３号公報、同５９－５２６８９号公報、同６２－２８００６９号公報、同６１－２４２８７１号公報、特開平４－２１９２６６号公報等に記載の蛍光増白剤等が挙げられる。 In the ink according to the present invention, in addition to the above surfactants, various known additives such as polysaccharides, viscosity modifiers, resistivity modifiers, film-forming agents, ultraviolet absorbers, antioxidants, etc. agents, anti-fading agents, anti-mold agents, anti-rust agents, etc. can be used by appropriately selecting them. No. 74193, No. 57-87988, No. 62-261476, etc. ultraviolet absorbers, JP-A-57-74192, No. 57-87989, No. 60-72785, No. 61 -146591, JP-A-1-95091, anti-fading agents described in JP-A-1-95091, JP-A-3-13376, JP-A-59-42993, JP-A-59-52689, JP-A-62-280069, Fluorescent whitening agents described in JP-A-61-242871, JP-A-4-219266 and the like.
　［１．２　インクの物性］
　［１．２．１　粘度］
　吐出安定性が良好である観点から、本発明に係るインクの２５℃におけるせん断速度１０００［１／ｓ］時の粘度は、１５ｍＰａ・ｓ（１５ｃＰ）以下であることが好ましく、５～１０ｍＰａ・ｓの範囲内であることが好ましい。２５℃におけるせん断速度１０００［１／ｓ］時の粘度は、回転式レオメーター、例えば、アントンパール社製、ＭＣＲ－１０２を用いて、以下の見かけ粘度ηａと同様にして測定できる。 [1.2 Physical Properties of Ink]
[1.2.1 Viscosity]
From the viewpoint of good ejection stability, the viscosity of the ink according to the present invention at a shear rate of 1000 [1/s] at 25° C. is preferably 15 mPa·s (15 cP) or less, and 5 to 10 mPa·s. is preferably within the range of The viscosity at a shear rate of 1000 [1/s] at 25° C. can be measured using a rotational rheometer such as MCR-102 manufactured by Anton Paar in the same manner as the apparent viscosity η a below.
　また、吐出安定性向上の観点から、本発明に係るインクは、チキソ性が比較的低いことが好ましく、２５℃におけるチキソトロピック指数が０．８５～１．０の範囲内であることが好ましい。
　「チキソ性」とは、せん断応力を受け続けると粘度が次第に低下し、静止すると粘度が次第に上昇する性質のことをいい、本発明において、「チキソ性が比較的低い」とは、２５℃におけるチキソトロピック指数が比較的１．０に近い値であることをいう。 Further, from the viewpoint of improving ejection stability, the ink according to the present invention preferably has relatively low thixotropy, and preferably has a thixotropic index at 25° C. within the range of 0.85 to 1.0.
"Thixotropy" refers to the property that the viscosity gradually decreases when subjected to shear stress and the viscosity gradually increases when standing still. In the present invention, "relatively low thixotropy" refers to the It means that the thixotropic index is relatively close to 1.0.
　粘度方程式におけるチキソトロピック指数ｎは、以下の方法により算出できる。 The thixotropic index n in the viscosity equation can be calculated by the following method.
　下記に示す粘度方程式は、見かけ粘度ηａ［ｍＰａ・ｓ］とせん断速度Ｄ［１／ｓ］の関係を表す式であり、せん断速度Ｄ［１／ｓ］時の見かけ粘度ηａ［ｍＰａ・ｓ］は、回転式レオメーター、例えば、アントンパール社製、ＭＣＲ－１０２や、Ｅ型粘度計を用いて測定できる。
　粘度方程式；ηａ＝μＤｎ－１ The viscosity equation shown below is a formula that expresses the relationship between the apparent viscosity η a [mPa s] and the shear rate D [1/s], and the apparent viscosity ηa [mPa s ] can be measured using a rotational rheometer such as MCR-102 manufactured by Anton Paar, or an E-type viscometer.
Viscosity equation; η a = μD n−1
　具体的には、ＭＣＲ－１０２のローテーションモードで、温度：２５℃、時間設定：測定点１５０点、測定間隔：２ｓにて、せん断速度を１０００［１／ｓ］～１［１／ｓ］の範囲内として、見かけ粘度ηａ［ｍＰａ・ｓ］を測定する。縦軸（Ｙ軸）に見かけ粘度ηａ［ｍＰａ・ｓ］、横軸（Ｘ軸）にせん断速度［１／ｓ］をそれぞれ対数でとったグラフを作成し、グラフの傾き（ｎ－１）からチキソトロピック指数ｎを求める。なお、グラフの切片が非ニュートン粘性係数μである。 Specifically, in rotation mode of MCR-102, temperature: 25 ° C., time setting: 150 measurement points, measurement interval: 2 s, shear rate from 1000 [1 / s] to 1 [1 / s] Apparent viscosity η a [mPa·s] is measured within the range. Create a logarithmic graph of the apparent viscosity η a [mPa s] on the vertical axis (Y-axis) and the shear rate [1/s] on the horizontal axis (X-axis), and the slope of the graph (n-1) Obtain the thixotropic index n from Note that the intercept of the graph is the non-Newtonian viscosity coefficient μ.
　ここで、粘度方程式；ηａ＝μＤｎ－１から以下のとおり、ｎが求められる。
　ｌｏｇηａ＝ｌｏｇ（μＤ（ｎ－１））
　　　　　　＝ｌｏｇμ＋ｌｏｇ（Ｄ（ｎ－１））
　　　　　　＝ｌｏｇμ＋（ｎ－１）×ｌｏｇＤ
　ｌｏｇηａをＹ軸、ｌｏｇＤをＸ軸にとってプロットすると、Ｙ＝（ｎ－１）Ｘ＋ｌｏｇμとなり、傾き（ｎ－１）からｎを算出できる。 Here, n is obtained as follows from the viscosity equation; ηa=μDn−1.
log η a =log(μD (n−1) )
= log μ + log (D (n-1) )
= log μ + (n-1) x log D
Plotting log η a on the Y axis and log D on the X axis yields Y=(n−1)X+log μ, and n can be calculated from the slope (n−1).
　［２　処理液］
　本発明に係る処理液は、凝集剤、水及び有機溶剤を含有することを特徴とする。なお、インクと併用することにより、凝集剤がインク中の色材を凝集し、記録物の画質を向上することができるものであれば、特に制限されず、前処理液であっても後処理液であってもよい。 [2 Treatment liquid]
The treatment liquid according to the present invention is characterized by containing a coagulant, water and an organic solvent. There is no particular limitation, as long as the aggregating agent can aggregate the coloring material in the ink and improve the image quality of the recorded matter when used in combination with the ink. It may be liquid.
　なお、「前処理液」とは、記録媒体表面にインクを付与する前又は同時に、記録媒体表面に付与する処理液のことをいい、「後処理液」とは、記録媒体表面にインクを付与した後に、記録媒体表面に付与する処理液のことをいう。
　以下、本発明において好適に用いられる前処理液の一例について説明する。 The term "pre-treatment liquid" refers to a treatment liquid that is applied to the surface of the recording medium before or at the same time as the application of ink to the surface of the recording medium, and the term "post-treatment liquid" refers to the application of ink to the surface of the recording medium. It refers to a treatment liquid that is applied to the surface of the recording medium after the treatment.
An example of the pretreatment liquid suitable for use in the present invention will be described below.
　［２．１　処理液の構成］
　［２．１．１　凝集剤］
　本発明に係る処理液は、凝集剤を含有することにより、インク中の色材を凝集することができ、記録物の画質を向上することができる。
　凝集剤としては、色材を凝集することができるものであれば特に制限されないが、通常、色材がアニオン性の成分であることから、例えば、金属塩、カチオン性化合物、酸等が挙げられる。なお、凝集剤は、一種類のみを単独で用いてもよく、二種類以上を併用してもよい。 [2.1 Structure of treatment liquid]
[2.1.1 Flocculant]
By containing an aggregating agent, the treatment liquid according to the present invention can aggregate the coloring material in the ink, and can improve the image quality of the recorded matter.
The aggregating agent is not particularly limited as long as it can aggregate the coloring material, but since the coloring material is usually an anionic component, examples thereof include metal salts, cationic compounds, acids, and the like. . The flocculants may be used singly or in combination of two or more.
　［２．１．１．１　金属塩］
　（多価金属塩）
　凝集性の観点から、金属塩の中でも多価金属塩であることが好ましい。多価金属塩は、塩析によって上記インク中の色材等のアニオン性の成分を凝集することができる。 [2.1.1.1 Metal salt]
(Polyvalent metal salt)
From the viewpoint of cohesiveness, among metal salts, polyvalent metal salts are preferred. The polyvalent metal salt can aggregate anionic components such as the coloring material in the ink by salting out.
　多価金属塩としては、２価以上の価数をもつ金属の塩を用いることができる。多価金属塩を構成する金属（カチオン）の種類は特に制限されないが、例えば、Ｃａ２＋、Ｃｕ２＋、Ｎｉ２＋、Ｍｇ２＋、Ｚｎ２＋、Ｂａ２＋などの２価金属イオン、Ａｌ３＋、Ｆｅ３＋、Ｃｒ３＋、Ｙ３＋などの３価金属イオン、Ｚｒ４＋などの４価金属イオン等が挙げられる。
　水溶性の観点から、Ｃａ２＋、Ｍｇ２＋、Ｚｎ２＋又はＡｌ３＋であることが好ましく、Ｃａ２＋又はＭｇ２＋であることがより好ましい。 As polyvalent metal salts, salts of metals having a valence of two or more can be used. The type of metal (cation ) that constitutes the polyvalent metal salt is not particularly limited . , Cr 3+ , Y 3+ and other trivalent metal ions, and Zr 4+ and other tetravalent metal ions.
From the viewpoint of water solubility, Ca 2+ , Mg 2+ , Zn 2+ or Al 3+ is preferable, and Ca 2+ or Mg 2+ is more preferable.
　多価金属塩を構成するアニオンの種類は特に制限されず、無機イオンであっても有機イオンであってもよい。無機イオンとしては、例えば、炭酸イオン、硫酸イオン、硝酸イオン、リン酸イオン、塩化物イオン、水酸化物イオン等が挙げられ、有機イオンとしては、例えば、ホウ酸イオン、カルボン酸イオン等の有機酸イオンが挙げられる。 The type of anion that constitutes the polyvalent metal salt is not particularly limited, and may be an inorganic ion or an organic ion. Examples of inorganic ions include carbonate ions, sulfate ions, nitrate ions, phosphate ions, chloride ions, and hydroxide ions. Examples of organic ions include organic ions such as borate ions and carboxylate ions. acid ions.
　多価金属塩の例としては、重質炭酸カルシウム及び軽質炭酸カルシウムなどの炭酸カルシウム、硝酸カルシウム、塩化カルシウム、硫酸カルシウム、硫酸マグネシウム、水酸化カルシウム、塩化マグネシウム、炭酸マグネシウム、硫酸バリウム、塩化バリウム、炭酸亜鉛、硫化亜鉛、珪酸アルミニウム、珪酸カルシウム、珪酸マグネシウム、硝酸銅、酢酸カルシウム、酢酸マグネシウム、酢酸アルミニウム等が挙げられる。
　これらは、一種類単独で用いてもよいし、二種類以上併用してもよい。 Examples of polyvalent metal salts include calcium carbonate such as heavy calcium carbonate and light calcium carbonate, calcium nitrate, calcium chloride, calcium sulfate, magnesium sulfate, calcium hydroxide, magnesium chloride, magnesium carbonate, barium sulfate, barium chloride, zinc carbonate, zinc sulfide, aluminum silicate, calcium silicate, magnesium silicate, copper nitrate, calcium acetate, magnesium acetate, aluminum acetate and the like.
These may be used singly or in combination of two or more.
　中でも、水溶性が良好であり、かつ、処理液による跡残りが低減する、すなわち、跡が目立たなくなる観点から、硫酸マグネシウム、硝酸カルシウム又は塩化カルシウムであることが好ましい。
　なお、これらの金属塩は、原料形態において水和水を有していてもよい。 Among them, magnesium sulfate, calcium nitrate, or calcium chloride is preferable from the viewpoints of having good water solubility and reducing traces left by the treatment liquid, that is, from the viewpoint of inconspicuous traces.
In addition, these metal salts may have water of hydration in the raw material form.
　（一価の金属塩）
　多価金属塩以外の金属塩としては、ナトリウム塩、カリウム塩等の一価の金属塩が、挙げられ、例えば、硫酸ナトリウム、硫酸カリウム等が挙げられる。 (monovalent metal salt)
Examples of metal salts other than polyvalent metal salts include monovalent metal salts such as sodium salts and potassium salts, such as sodium sulfate and potassium sulfate.
　金属塩の含有量は、処理液の全質量に対して、５質量％以下であることが好ましく、０．１～３質量％の範囲内であることがより好ましく、０．５～１．０質量％の範囲内であることが更に好ましい。上記範囲内であることにより、インク中の色材等のアニオン性の成分を効果的に凝集することができるため、画質と耐熱水性を両立することができる。
　金属塩の含有量は、例えばＩＣＰ発光分析等の公知の方法により測定できる。 The content of the metal salt is preferably 5% by mass or less, more preferably in the range of 0.1 to 3% by mass, more preferably 0.5 to 1.0% by mass, based on the total mass of the treatment liquid. It is more preferable to be within the mass % range. Within the above range, the anionic components such as the coloring material in the ink can be effectively aggregated, so that both image quality and hot water resistance can be achieved.
The metal salt content can be measured by a known method such as ICP emission spectrometry.
　記録媒体に付与される処理液において、金属塩の付量が０．１～２０ｇ／ｍ２の範囲内であることが好ましく、上記範囲内となるように、処理液の付量を調整することが好ましい。 In the treatment liquid applied to the recording medium, the applied amount of the metal salt is preferably within the range of 0.1 to 20 g/m 2 , and the applied amount of the treatment liquid is adjusted so as to fall within the above range. is preferred.
　［２．１．１．２　カチオン性化合物］
　（カチオン性ポリマー）
　水溶性の観点から、カチオン性化合物の中でも、水溶性のカチオン性ポリマーであることが好ましい。 [2.1.1.2 Cationic compound]
(Cationic polymer)
From the viewpoint of water solubility, among the cationic compounds, a water-soluble cationic polymer is preferred.
　カチオン性ポリマーとしては、例えば、カチオン性のウレタン系樹脂、カチオン性のオレフィン系樹脂、カチオン性のアミン系樹脂等が挙げられる。 Examples of cationic polymers include cationic urethane-based resins, cationic olefin-based resins, and cationic amine-based resins.
　カチオン性のウレタン系樹脂としては、市販品を用いることができ、例えば、ハイドラン（登録商標）ＣＰ－７０１０、ＣＰ－７０２０、ＣＰ－７０３０、ＣＰ－７０４０、ＣＰ－７０５０、ＣＰ－７０６０、ＣＰ－７６１０（商品名、大日本インキ化学工業社製）、スーパーフレックス （登録商標）６００、６１０、６２０、６３０、６４０、６５０（商品名、第一工業製薬社製）、ウレタンエマルジョン　ＷＢＲ－２１２０Ｃ、ＷＢＲ－２１２２Ｃ（商品名、大成ファインケミカル社製）等を用いることができる。 As the cationic urethane resin, commercially available products can be used, for example, Hydran (registered trademark) CP-7010, CP-7020, CP-7030, CP-7040, CP-7050, CP-7060, CP- 7610 (trade name, manufactured by Dainippon Ink and Chemicals), Superflex (registered trademark) 600, 610, 620, 630, 640, 650 (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), urethane emulsion WBR-2120C, WBR -2122C (trade name, manufactured by Taisei Fine Chemical Co., Ltd.) or the like can be used.
　カチオン性のオレフィン系樹脂は、エチレン、プロピレン等のオレフィンを構造骨格に有する樹脂であり、公知のものを適宜選択して用いることができる。また、カチオン性のオレフィン系樹脂は、水や有機溶剤等を含む溶剤に分散させたエマルジョン状態であってもよい。カチオン性のオレフィン系樹脂としては、市販品を用いることができ、例えば、アローベース（登録商標）ＣＢ－１２００、ＣＤ－１２００（商品名、ユニチカ社製）等が挙げられる。 The cationic olefin-based resin is a resin having an olefin such as ethylene, propylene, or the like in its structural skeleton, and a known one can be appropriately selected and used. Moreover, the cationic olefin resin may be in an emulsion state dispersed in a solvent containing water, an organic solvent, or the like. As the cationic olefin resin, commercially available products can be used, such as Arrowbase (registered trademark) CB-1200 and CD-1200 (trade name, manufactured by Unitika Ltd.).
　カチオン性のアミン系樹脂としては、構造中にアミノ基を有するものであればよく、公知のものを適宜選択して用いることができる。例えば、樹脂の主骨格中にアミノ基を有するポリアミン樹脂、樹脂の主骨格中にアミド基を有するポリアミド樹脂、樹脂の主骨格中にアリル基を有するポリアリルアミン樹脂等が挙げられる。 As the cationic amine-based resin, any one having an amino group in its structure can be used, and a known one can be appropriately selected and used. Examples thereof include polyamine resins having amino groups in the main skeleton of the resin, polyamide resins having amide groups in the main skeleton of the resin, and polyallylamine resins having allyl groups in the main skeleton of the resin.
　カチオン性のポリアミン樹脂としては、市販品を用いることができ、例えば、ユニセンスＫＨＥ１０３Ｌ（商品名、センカ社製、ヘキサメチレンジアミン／エピクロルヒドリン樹脂、１％水溶液のｐＨ約５．０、粘度２０～５０（ｍＰａ・ｓ）、固形分濃度５０質量％の水溶液）、ユニセンスＫＨＥ１０４Ｌ（商品名、センカ社製、ジメチルアミン／エピクロルヒドリン樹脂、１％水溶液のｐＨ約７．０、粘度１～１０（ｍＰａ・ｓ）、固形分濃度２０質量％の水溶液）、等が挙げられる。 As the cationic polyamine resin, a commercially available product can be used. mPa s), aqueous solution with a solid concentration of 50% by mass), Unisense KHE104L (trade name, manufactured by Senka Co., Ltd., dimethylamine/epichlorohydrin resin, pH of 1% aqueous solution of about 7.0, viscosity 1 to 10 (mPa s) , an aqueous solution having a solid concentration of 20% by mass), and the like.
　また、ＦＬ－１４（商品名、ＳＮＦ社製）、アラフィックス（登録商標）１００、２５１Ｓ、２５５、２５５ＬＯＸ（商品名、荒川化学社製）、ＤＫ－６８１０、６８５３、６８８５；ＷＳ－４０１０、４０１１、４０２０、４０２４、４０２７、４０３０（商品名、星光ＰＭＣ社製）、パピオゲン（登録商標）Ｐ－１０５（商品名、センカ社製）、スミレーズレジン６５０（３０）、６７５Ａ、６６１５、ＳＬＸ－１（商品名、田岡化学工業社製）、カチオマスター（登録商標）ＰＤ－１、７、３０、Ａ、ＰＤＴ－２、ＰＥ－１０、ＰＥ－３０、ＤＴ－ＥＨ、ＥＰＡ－ＳＫ０１、ＴＭＨＭＤＡ－Ｅ（商品名、四日市合成社製）、ジェットフィックス３６Ｎ、３８Ａ、５０５２（商品名、里田化工社製）が挙げられる。 In addition, FL-14 (trade name, manufactured by SNF), Arafix (registered trademark) 100, 251S, 255, 255LOX (trade name, manufactured by Arakawa Chemical Co., Ltd.), DK-6810, 6853, 6885; WS-4010, 4011 , 4020, 4024, 4027, 4030 (trade name, manufactured by Seiko PMC), Papiogen (registered trademark) P-105 (trade name, manufactured by Senka), Sumilaze Resin 650 (30), 675A, 6615, SLX-1 (trade name, manufactured by Taoka Chemical Co., Ltd.), Catiomaster (registered trademark) PD-1, 7, 30, A, PDT-2, PE-10, PE-30, DT-EH, EPA-SK01, TMHMDA-E (trade name, manufactured by Yokkaichi Gosei Co., Ltd.), Jetfix 36N, 38A, and 5052 (trade name, manufactured by Satoda Kako Co., Ltd.).
　ポリアリルアミン樹脂の例としては、ポリアリルアミン塩酸塩、ポリアリルアミンアミド硫酸塩、アリルアミン塩酸塩・ジアリルアミン塩酸塩コポリマー、アリルアミン酢酸塩・ジアリルアミン酢酸塩コポリマー、アリルアミン酢酸塩・ジアリルアミン酢酸塩コポリマー、アリルアミン塩酸塩・ジメチルアリルアミン塩酸塩コポリマー、アリルアミン・ジメチルアリルアミンコポリマー、ポリジアリルアミン塩酸塩、ポリメチルジアリルアミン塩酸塩、ポリメチルジアリルアミンアミド硫酸塩、ポリメチルジアリルアミン酢酸塩、ポリジアリルジメチルアンモニウムクロリド、ジアリルアミン酢酸塩・二酸化硫黄コポリマー、ジアリルメチルエチルアンモニウムエチルサルフェイト・二酸化硫黄コポリマー、メチルジアリルアミン塩酸塩・二酸化硫黄コポリマー、ジアリルジメチルアンモニウムクロリド・二酸化硫黄コポリマー、ジアリルジメチルアンモニウムクロリド・アクリルアミドコポリマー等が挙げられる。 Examples of polyallylamine resins include polyallylamine hydrochloride, polyallylamine amide sulfate, allylamine hydrochloride/diallylamine hydrochloride copolymer, allylamine acetate/diallylamine acetate copolymer, allylamine acetate/diallylamine acetate copolymer, allylamine hydrochloride/ Dimethylallylamine hydrochloride copolymer, allylamine/dimethylallylamine copolymer, polydiallylamine hydrochloride, polymethyldiallylamine hydrochloride, polymethyldiallylamine amide sulfate, polymethyldiallylamine acetate, polydiallyldimethylammonium chloride, diallylamine acetate/sulfur dioxide copolymer, diallylmethylethylammonium ethylsulfate/sulfur dioxide copolymer, methyldiallylamine hydrochloride/sulfur dioxide copolymer, diallyldimethylammonium chloride/sulfur dioxide copolymer, diallyldimethylammonium chloride/acrylamide copolymer and the like.
　また、上記の酸塩タイプ以外の、酸で中和されていないフリータイプのポリアリルアミン樹脂を用いてもよい。フリータイプ形態の方が、水を含有する処理液に用いた場合に、処理液のｐＨを中性からアルカリ性側に容易に調整することができ、インクジェット記録装置部材の耐久性・腐食等に対して有利であるため好ましい。フリータイプのポリアリルアミン樹脂の例としては、ＰＡＡ－０１、ＰＡＡ－０３、ＰＡＡ－０５、ＰＡＡ－０８、ＰＡＡ－１５、ＰＡＡ－１５Ｃ，ＰＡＡ－２５（商品名、ニットーボーメディカル社製）が挙げられる。 Also, a free-type polyallylamine resin that is not neutralized with an acid may be used, other than the above acid salt type. When the free type type is used for a processing liquid containing water, the pH of the processing liquid can be easily adjusted from neutral to alkaline side, and durability and corrosion of ink jet recording device members are prevented. preferred because it is advantageous Examples of free-type polyallylamine resins include PAA-01, PAA-03, PAA-05, PAA-08, PAA-15, PAA-15C, and PAA-25 (trade names, manufactured by Nittobo Medical). .
　カチオン性ポリマーの含有量は、処理液の全質量に対して、１～５質量％の範囲内であることが好ましい。 The content of the cationic polymer is preferably within the range of 1 to 5% by mass with respect to the total mass of the treatment liquid.
　［２．１．１．３　酸］
　（有機酸）
　処理液の保存安定性の観点から、また、処理液を塗布、乾燥した後にブロッキングを抑制できる観点から、酸の中でも有機酸であることが好ましい。有機酸は、ｐＨ変動によって上記インク中の色材等のアニオン性の成分を凝集させることができる。 [2.1.1.3 Acid]
(organic acid)
From the viewpoint of the storage stability of the treatment liquid and from the viewpoint of suppressing blocking after coating and drying the treatment liquid, organic acids are preferred among the acids. The organic acid can aggregate the anionic components such as the coloring material in the ink by changing the pH.
　有機酸としては、例えば、ギ酸、酢酸、プロピオン酸、イソ酪酸、シュウ酸、フマル酸、リンゴ酸、クエン酸、マロン酸、コハク酸、マレイン酸、安息香酸、２－ピロリドン－５－カルボン酸、乳酸、アクリル酸又はその誘導体、メタクリル酸又はその誘導体、アクリルアミド又はその誘導体、スルホン酸誘導体等が挙げられる。
　これらは、一種類単独で用いてもよいし、二種類以上併用してもよい。 Examples of organic acids include formic acid, acetic acid, propionic acid, isobutyric acid, oxalic acid, fumaric acid, malic acid, citric acid, malonic acid, succinic acid, maleic acid, benzoic acid, 2-pyrrolidone-5-carboxylic acid, Examples include lactic acid, acrylic acid or derivatives thereof, methacrylic acid or derivatives thereof, acrylamide or derivatives thereof, sulfonic acid derivatives and the like.
These may be used singly or in combination of two or more.
　有機酸は、塩基により完全には中和されていないものを用いることが好ましい。塩基による中和とは、これらの酸の酸性基と、正に帯電した他の元素又は化合物（例えば、金属などの無機化合物）と、がイオン結合していることを意味する。また、完全には中和されていないとは、有機酸が有する酸性基のうち、上記イオン結合を形成していない酸性基が存在することを意味する。 It is preferable to use an organic acid that has not been completely neutralized with a base. Neutralization with a base means that the acidic groups of these acids are ionically bonded with other positively charged elements or compounds (eg, inorganic compounds such as metals). In addition, "not completely neutralized" means that among the acidic groups of the organic acid, there are acidic groups that do not form the above ionic bond.
　（無機酸）
　有機酸以外の酸としては、無機酸が挙げられ、硫酸、塩酸、硝酸、リン酸等が挙げられる。
　これらは、一種類単独で用いてもよいし、二種類以上併用してもよい。 (inorganic acid)
Acids other than organic acids include inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid.
These may be used singly or in combination of two or more.
　酸の含有量は、処理液の全質量に対して、５質量％以下であることが好ましく、０．１～３質量％の範囲内であることがより好ましく、０．５～１．０質量％の範囲内であることが更に好ましい。上記範囲内であることにより、インク中の色材等のアニオン性の成分を効果的に凝集することができるため、画質と耐熱水性を両立することができる。
　酸の含有量は、例えば高速液体クロマトグラフィー（ＨＰＬＣ）等の公知の方法で測定できる。 The content of the acid is preferably 5% by mass or less, more preferably in the range of 0.1 to 3% by mass, more preferably 0.5 to 1.0% by mass, relative to the total mass of the treatment liquid. % range is more preferred. Within the above range, the anionic components such as the coloring material in the ink can be effectively aggregated, so that both image quality and hot water resistance can be achieved.
The acid content can be measured by a known method such as high performance liquid chromatography (HPLC).
　記録媒体に付与される処理液において、酸の付量がインク中のアニオン成分の中和当量以下であることが好ましく、上記範囲内となるように、処理液の付量を調整することが好ましい。 In the treatment liquid applied to the recording medium, the amount of acid applied is preferably equal to or less than the neutralization equivalent of the anionic component in the ink, and the amount of application of the treatment liquid is preferably adjusted so as to fall within the above range. .
　［２．１．２　水］
　本発明に係る処理液は、水を含有することにより、溶剤インクと比較して、ＶＯＣ（volatile organic compounds：揮発性有機化合物）等の有機溶剤の含有量を低減することができる。水については、特に制限されず、イオン交換水、蒸留水又は純水が挙げられる。
　処理液における水の含有量は、処理液の全質量に対して、５０～９０質量％の範囲内であることが好ましい。 [2.1.2 Water]
By containing water, the treatment liquid according to the present invention can reduce the content of organic solvents such as VOCs (volatile organic compounds) as compared with solvent inks. Water is not particularly limited, and ion-exchanged water, distilled water, or pure water can be used.
The content of water in the treatment liquid is preferably in the range of 50 to 90% by weight with respect to the total weight of the treatment liquid.
　［２．１．３　有機溶剤］
　本発明に係る処理液は、有機溶剤を含有することにより、記録媒体における処理液の濡れ性、及び、処理液の保湿性を向上させることができる。有機溶剤としては、水溶性の有機溶剤であることが好ましく、例えば、アルコール類、多価アルコール類、アミン類、アミド類、グリコールエーテル類、炭素数が４以上である１，２－アルカンジオール類などが挙げられ、前述のインクに含有される有機溶剤と同様のものを使用できる。
　処理液における有機溶剤の含有量は、処理液の全質量に対して、５～４５質量％の範囲内であることが好ましい。 [2.1.3 Organic solvent]
By containing an organic solvent, the treatment liquid according to the present invention can improve the wettability of the treatment liquid on the recording medium and the moisture retention of the treatment liquid. The organic solvent is preferably a water-soluble organic solvent such as alcohols, polyhydric alcohols, amines, amides, glycol ethers, and 1,2-alkanediols having 4 or more carbon atoms. and the like, and the same organic solvents as those contained in the ink described above can be used.
The content of the organic solvent in the treatment liquid is preferably in the range of 5 to 45% by weight with respect to the total weight of the treatment liquid.
　［２．１．４　添加剤］
　本発明に係る処理液は、発明の効果を損なわない範囲で、界面活性剤、架橋剤、防黴剤、殺菌剤等、他の成分を適宜含有させてもよい。 [2.1.4 Additives]
The treatment liquid according to the present invention may appropriately contain other components such as a surfactant, a cross-linking agent, an antifungal agent, and a bactericide within a range that does not impair the effects of the present invention.
　さらに、例えば、特開昭５７－７４１９３号公報、同５７－８７９８８号公報及び同６２－２６１４７６号公報に記載の紫外線吸収剤、特開昭５７－７４１９２号公報、同５７－８７９８９号公報、同６０－７２７８５号公報、同６１－１４６５９１号公報、特開平１－９５０９１号公報及び同３－１３３７６号公報等に記載の退色防止剤、アニオン、カチオン又は非イオンの各種界面活性剤、特開昭５９－４２９９３号公報、同５９－５２６８９号公報、同６２－２８００６９号公報、同６１－２４２８７１号公報及び特開平４－２１９２６６号公報等に記載の蛍光増白剤、消泡剤、ジエチレングリコール等の潤滑剤、防腐剤、増粘剤、帯電防止剤等、公知の各種添加剤を含有させてもよい。 Furthermore, for example, the UV absorber described in JP-A-57-74193, JP-A-57-87988 and JP-A-62-261476, JP-A-57-74192, JP-A-57-87989, the same 60-72785, 61-146591, anti-fading agents described in JP-A-1-95091 and JP-A-3-13376, various anionic, cationic or nonionic surfactants, JP-A 59-42993, 59-52689, 62-280069, 61-242871 and JP-A-4-219266, such as fluorescent brighteners, defoaming agents, diethylene glycol, etc. Various known additives such as lubricants, preservatives, thickeners and antistatic agents may be incorporated.
　［２．２　処理液の物性］
　［２．２．１　粘度］
　吐出安定性が良好である観点から、本発明に係る処理液の２５℃におけるせん断速度１０００［１／ｓ］時の粘度は、１５ｍＰａ・ｓ（１５ｃＰ）以下であることが好ましく、５～１０ｍＰａ・ｓの範囲内であることが好ましい。２５℃におけるせん断速度１０００［１／ｓ］時の粘度は、回転式レオメーター、例えば、アントンパール社製、ＭＣＲ－１０２を用いて、以下の見かけ粘度ηａと同様にして測定できる。 [2.2 Physical properties of treatment liquid]
[2.2.1 Viscosity]
From the viewpoint of good ejection stability, the viscosity of the treatment liquid according to the present invention at a shear rate of 1000 [1/s] at 25° C. is preferably 15 mPa·s (15 cP) or less, and preferably 5 to 10 mPa·s. It is preferably within the range of s. The viscosity at a shear rate of 1000 [1/s] at 25° C. can be measured using a rotational rheometer such as MCR-102 manufactured by Anton Paar in the same manner as the apparent viscosity η a below.
　［３　インクジェット記録用インクセット］
　本発明のインクジェット記録用インクセットは、インク及び処理液を含むインクジェット記録用インクセットであり、インク及び処理液が、記録媒体表面において、液体同士で合一することが好ましい。すなわち、液体状態のインクと処理液が記録媒体表面で混合し、その混合液により画像を形成することが好ましい。 [3 Ink set for inkjet recording]
The ink set for inkjet recording of the present invention is an ink set for inkjet recording containing an ink and a treatment liquid, and it is preferable that the ink and the treatment liquid coalesce with each other on the surface of the recording medium. That is, it is preferable that the ink in the liquid state and the treatment liquid are mixed on the surface of the recording medium, and the mixed liquid is used to form an image.
　なお、インクと処理液は、完全に混合する必要はなく、一部が混合していればよい。以下、インクと処理液が完全に混合したもの又は一部が混合したものを「混合液」とする。 It should be noted that the ink and the treatment liquid do not have to be completely mixed, and only need to be partially mixed. Hereinafter, a mixture in which the ink and the treatment liquid are completely mixed or partially mixed is referred to as a "mixed liquid".
　本発明においては、ウェット・オン・ウェット方式を用いることにより、液体状態のインクと処理液を記録媒体表面で混合することができる。ウェット・オン・ウェット方式については、詳しくは後述する。 In the present invention, by using the wet-on-wet method, liquid ink and treatment liquid can be mixed on the surface of the recording medium. The wet-on-wet method will be described later in detail.
　［３．１　混合液の物性］
　［３．１．１　粘度］
　増粘剤が、色材の過凝集を阻害する機能を有するか否かについては、本発明に係るインク（増粘剤を含む）と、当該インクのうち増粘剤を除いたものと、それぞれを処理液と混合させ、混合させたものの粘度を比較することによって、判別することができる。 [3.1 Physical properties of mixed liquid]
[3.1.1 Viscosity]
Regarding whether or not the thickener has a function of inhibiting overaggregation of the coloring material, the ink according to the present invention (including the thickener) and the ink excluding the thickener are examined. can be determined by mixing with the processing liquid and comparing the viscosities of the mixture.
　一般的に、インクと処理液を用いて記録物を得る場合、処理液中の凝集剤との反応により、インク中の色材が凝集し、インクと処理液の混合液の粘度が上昇するため、吸収性の低い・無い記録媒体に記録しても、ピニング性が良好であり、インクの液滴間のにじみや色ムラを抑制できる。色材の過凝集を阻害する機能を有する化合物を含有しないインクにおいては、ウェット・オン・ウェット方式においてインクと処理液を記録媒体上に付与すると、過凝集が生じやすく、インクと処理液の混合液の粘度は大きく上昇する。 In general, when an ink and a treatment liquid are used to obtain a recorded matter, the coloring material in the ink reacts with the coagulant in the treatment liquid, causing the coloring material in the ink to aggregate, and the viscosity of the mixed liquid of the ink and the treatment liquid increases. Even when recording is performed on a recording medium with low or no absorbency, the pinning property is good, and bleeding between ink droplets and color unevenness can be suppressed. For inks that do not contain a compound that inhibits overaggregation of the colorant, when the ink and treatment liquid are applied onto the recording medium in the wet-on-wet method, overaggregation tends to occur, and the mixing of the ink and the treatment liquid tends to occur. The viscosity of the liquid increases greatly.
　しかし、インクが、色材の過凝集を阻害する機能を有する化合物を含有する場合においては、その混合液の粘度は上昇するものの、粘度の変化率は緩やかになる。したがって、本発明においては、増粘剤が、色材の過凝集を阻害する機能を有するか否かについては、本発明に係るインク（増粘剤を含む）と、当該インクのうち増粘剤を除いたものと、それぞれを処理液と混合させ、混合させたものの粘度の変化率を比較することによって、判別することができる。 However, when the ink contains a compound having a function of inhibiting overaggregation of the coloring material, the viscosity of the mixed liquid increases, but the rate of change in viscosity becomes moderate. Therefore, in the present invention, whether or not the thickener has a function of inhibiting overaggregation of the coloring material is determined by the ink (including the thickener) according to the present invention and the thickener in the ink. can be determined by comparing the rate of change in the viscosity of a sample obtained by mixing each sample with the treatment liquid and the sample obtained by mixing the sample with the processing liquid.
　具体的には、以下の方法により、増粘剤が、色材の過凝集を阻害する機能を有するか否かについて判別することができる。 Specifically, the following method can be used to determine whether or not the thickener has a function of inhibiting excessive aggregation of the coloring material.
　本発明のインク（本発明に係る増粘剤を含む）を組成物Ａとし、当該インクのうち、本発明に係る増粘剤を除いたもの（増粘剤の代わりに水を添加）を組成物Ｂとし、組成物Ａと本発明に係る処理液とを混合させたものを組成物Ｃとし、かつ、組成物Ｂと本発明に係る処理液とを混合させたものを組成物Ｄとする。そして、組成物Ａ及びＢの２５℃におけるせん断速度１０００［１／ｓ］時の粘度をそれぞれＶＡ及びＶＢ、組成物Ｃ及びＤの２５℃におけるせん断速度２［１／ｓ］時の粘度をそれぞれＶＣ及びＶＤとし、ＶＡ～ＶＤが、下記関係式（１）及び（２）を満たす場合、当該増粘剤が色材の過凝集を阻害する機能を有すると判別できる。
　式（１）：　ＶＡ＞ＶＢ
　式（２）：　ＶＣ≦ＶＤ The ink of the present invention (including the thickener of the present invention) is designated as composition A, and the ink excluding the thickener of the present invention (water is added instead of the thickener) is composed. Composition B is obtained by mixing Composition A and the treatment liquid according to the present invention, and Composition C is obtained by mixing Composition A and the treatment liquid according to the present invention. Composition D is obtained by mixing Composition B and the treatment liquid according to the present invention. . Then, the viscosities of compositions A and B at a shear rate of 1000 [1 / s] at 25 ° C. are V A and V B , and the viscosities of compositions C and D at a shear rate of 2 [1 / s] at 25 ° C. are V C and V D respectively, and when V A to V D satisfy the following relational expressions (1) and (2), it can be determined that the thickener has a function of inhibiting excessive aggregation of the coloring material.
Formula (1): V A >V B
Formula (2): V C ≤ V D
　組成物Ａ及びＢの２５℃におけるせん断速度１０００［１／ｓ］時の粘度が、式（１）を満たすことにより、インクジェットヘッドのノズルから吐出する（外力が比較的大きく流動している）際に、組成物Ａの粘度の方が組成物Ｂの粘度より高くなることが想定され、本発明に係る増粘剤が、増粘作用を有することがわかる。
　また、組成物Ｃ及びＤの２５℃におけるせん断速度２［１／ｓ］時の粘度が、式（２）を満たすことにより、記録媒体表面にインクと処理液が付与された（外力が比較的小さくほぼ静止している）際に、組成物Ｃの粘度が、組成物Ｄの粘度より低い又は同じになることが想定され、本発明に係る増粘剤が過凝集を阻害する機能を有することがわかる。 When the viscosities of the compositions A and B at a shear rate of 1000 [1/s] at 25° C. satisfy the formula (1), when ejecting from the nozzle of the inkjet head (the external force is relatively large and flowing) Furthermore, it is assumed that the viscosity of composition A is higher than that of composition B, and it can be seen that the thickener according to the present invention has a thickening effect.
In addition, the viscosities of Compositions C and D at a shear rate of 2 [1/s] at 25° C. satisfy formula (2), so that the ink and the treatment liquid are applied to the surface of the recording medium (the external force is relatively It is assumed that the viscosity of the composition C is lower than or the same as the viscosity of the composition D when the I understand.
　組成物Ｃ及び組成物Ｄにおいて、その混合比（組成物Ａ又はＢと処理液との混合比）は、特に制限されず、組成物Ａ、Ｂ及び処理液の構成成分によってその好適な範囲は異なるが、組成物Ａ又はＢの全質量に対して、処理液を１０～１００質量％の範囲内で混合させることが好ましい。 In composition C and composition D, the mixing ratio (mixing ratio of composition A or B and treatment liquid) is not particularly limited, and the preferred range is Although different, it is preferable to mix the treatment liquid within the range of 10 to 100% by mass with respect to the total mass of composition A or B.
　２５℃におけるせん断速度１０００［１／ｓ］時の粘度は、回転式レオメーター、例えば、アントンパール社製、ＭＣＲ－１０２を用いて、前述の見かけ粘度ηａと同様にして測定できる。 The viscosity at a shear rate of 1000 [1/s] at 25° C. can be measured using a rotary rheometer, for example, MCR-102 manufactured by Anton Paar, in the same manner as the apparent viscosity η a described above.
　また、ピニング性が良好である観点から、本発明に係る混合液の２５℃におけるせん断速度２［１／ｓ］時の粘度は、１５ｍＰａ・ｓ（１５ｃＰ）以上であることが好ましい。２５℃におけるせん断速度２［１／ｓ］時の粘度は、回転式レオメーター、例えば、アントンパール社製、ＭＣＲ－１０２、Ｅ型粘度計（ＴＶＥ－３３ＬＴ、東機産業社製）等を用いて測定できる。 In addition, from the viewpoint of good pinning properties, the viscosity of the mixture according to the present invention at a shear rate of 2 [1/s] at 25°C is preferably 15 mPa·s (15 cP) or more. The viscosity at a shear rate of 2 [1 / s] at 25 ° C. is measured using a rotary rheometer, such as MCR-102 manufactured by Anton Paar, E-type viscometer (TVE-33LT, manufactured by Toki Sangyo Co., Ltd.), etc. can be measured
　Ｅ型粘度計を用いて測定する場合には、Ｅ型粘度計のコーンローターの回転数（回転速度）を可変することで、規定のせん断速度での試料の粘度を測定できる。具体的には、回転数を２０ｒｐｍ、つまり、せん断速度が２［１／ｓ］となる条件下で、粘度を測定する。
　なお、せん断速度［１／ｓ］は、下記式により算出することができる。
　せん断速度［１／ｓ］＝せん断速度係数×回転数 When measuring using an E-type viscometer, the viscosity of a sample can be measured at a prescribed shear rate by varying the rotational speed (rotational speed) of the cone rotor of the E-type viscometer. Specifically, the viscosity is measured under the condition that the rotation speed is 20 rpm, that is, the shear rate is 2 [1/s].
In addition, the shear rate [1/s] can be calculated by the following formula.
Shear rate [1/s] = shear rate factor x number of revolutions
　［３．１．２　粗大粒子数］
　また、増粘剤が、色材の過凝集を阻害する機能を有するか否かについては、本発明に係るインク（増粘剤を含む）と、当該インクのうち増粘剤を除いたものと、それぞれを処理液と混合させ、混合させたものの粗大粒子数の割合を比較することによって、判別することができる。 [3.1.2 Number of coarse particles]
In addition, whether or not the thickener has a function of inhibiting overaggregation of the coloring material is determined by comparing the ink (including the thickener) according to the present invention and the ink excluding the thickener. , are mixed with the treatment liquid, and the ratio of the number of coarse particles in the mixture is compared.
　すなわち、上記組成物Ｃ及びＤにおける５μｍ以上の粗大粒子数の割合ＲＣ及びＲＤが、下記関係式（３）を満たす場合、当該増粘剤が色材の過凝集を阻害する機能を有すると判別できる。
　式（３）：　ＲＣ／ＲＤ＜１ That is, when the ratios R C and R D of the number of coarse particles of 5 μm or more in the compositions C and D satisfy the following relational expression (3), the thickener has a function of inhibiting overaggregation of the coloring material. Then you can tell.
Formula (3): R C /R D <1
　５μｍ以上の粗大粒子数の割合は、以下の方法で算出できる。
　上記組成物Ｃ及びＤについて、純水にて１００００倍に希釈後、パーティクルカウンター（ＲＩＯＮ社製、センサー：ＰＡＲＴＩＣＬＥ　ＳＥＮＳＯＲ　ＫＳ－４２Ｃ、コントローラー：ＣＯＮＴＲＯＬＬＥＲ　ＫＥ－４０Ｂ１、ポンプ：ＳＹＲＩＮＧＥ　ＳＡＭＰＬＥＲ　ＫＺ－３１Ｗ）にて、流量１０ｍＬ／ｍｉｎの条件で、粒径が０．５、１、２、３、５、７．５、１０、１２、１５及び２０μｍの粒子数を、それぞれカウントする。なお、粒子数の測定は３回実施し、その平均値を採用する。 The ratio of the number of coarse particles of 5 μm or more can be calculated by the following method.
After diluting the compositions C and D 10,000 times with pure water, using a particle counter (manufactured by RION, sensor: PARTICLE SENSOR KS-42C, controller: CONTROLLER KE-40B1, pump: SYRINGE SAMPLER KZ-31W) , and the flow rate is 10 mL/min. The number of particles is measured three times, and the average value is adopted.
　組成物Ｃ及び組成物Ｄについて、全粒子数（上記粒径の粒子数の総和）に対する、粒径が５μｍ以上の粒子数の割合をそれぞれ、ＲＣ及びＲＤとし、その比（ＲＣ／ＲＤ）を算出する。 For composition C and composition D, the ratio of the number of particles with a particle size of 5 μm or more to the total number of particles (total number of particles with the above particle size) is defined as R C and R D respectively, and the ratio (R C / R D ) is calculated.
　≪インクジェット記録方法の概要≫
　本発明のインクジェット記録方法は、本発明のインクジェット記録用インクセットを用い、上記インク及び処理液が、記録媒体表面において、液体同士で合一することを特徴とする。 <<Overview of inkjet recording method>>
The ink jet recording method of the present invention is characterized in that the ink set for ink jet recording of the present invention is used, and the ink and the treatment liquid are united with each other on the surface of the recording medium.
　インク及び処理液を、記録媒体表面において、液体同士で合一させて記録する方法を、「ウェット・オン・ウェット方式」という。ウェット・オン・ウェット方式では、液体状態のインクと処理液が記録媒体表面で合一（混合）することにより、インク中の色材と処理液中の凝集剤との接触する機会が増えるため、十分に凝集が進行する。しかし、従来のウェット・オン・ウェット方式では、場合によっては、凝集剤と色材からなる凝集物の粒径が大きくなりすぎる、すなわち、過凝集が生じやすく、画質の低下が問題であった。
　しかし、本発明のインクセットを用いることにより、過凝集が抑制され、良好な画質の記録物が得られる。 A recording method in which the ink and the treatment liquid are combined with each other on the surface of the recording medium for recording is called a “wet-on-wet method”. In the wet-on-wet method, the liquid ink and the treatment liquid coalesce (mix) on the surface of the recording medium, increasing the chances of contact between the coloring material in the ink and the coagulant in the treatment liquid. Aggregation progresses sufficiently. However, in the conventional wet-on-wet method, in some cases, the particle size of aggregates composed of the aggregating agent and the colorant becomes too large, that is, excessive aggregation tends to occur, resulting in a problem of deterioration in image quality.
However, by using the ink set of the present invention, over-aggregation is suppressed, and a good image quality recorded matter can be obtained.
　したがって、本発明のインクセットは、ウェット・オン・ウェット方式でのインクジェット記録の際に、顕著な効果を示す。なお、インクジェット記録によるウェット・オン・ウェット方式での記録は、良好な画質の記録物が得られるだけでなく、処理液を付与した後、すぐにインクを付与することができるため、処理液の乾燥時間を短縮できる、インク未塗布の部分には処理液を付与しないため、基材の質感を活かせる、さらに、１台のプリンターで、処理液の付与とインクの付与を行うことができる、等の利点がある。 Therefore, the ink set of the present invention exhibits remarkable effects during wet-on-wet inkjet recording. In addition, wet-on-wet recording by inkjet recording not only provides good image quality, but also allows ink to be applied immediately after applying the treatment liquid. Drying time can be shortened, treatment liquid is not applied to areas not coated with ink, so the texture of the base material can be utilized, and treatment liquid application and ink application can be performed with a single printer. and other advantages.
　本発明のインクジェット記録方法は、１）処理液を記録媒体表面に付与する処理液付与工程と、２）付与された処理液上にインクを付与するインク付与工程と、３）記録媒体表面に付与された処理液及びインクの混合液を乾燥させる混合液乾燥工程と、を有することが好ましい。ここで、処理液付与工程は、インク付与工程の前に行っても、後に行っても、同時であってもよく、混合液乾燥工程は、処理液付与工程及びインク付与工程の後に行われる。 The inkjet recording method of the present invention comprises: 1) a treatment liquid application step of applying a treatment liquid to the surface of a recording medium; 2) an ink application step of applying ink onto the applied treatment liquid; and 3) application to the surface of a recording medium. and a mixed liquid drying step of drying the mixed liquid of the treated liquid and the ink. Here, the treatment liquid application process may be performed before, after, or at the same time as the ink application process, and the mixed liquid drying process is performed after the treatment liquid application process and the ink application process.
　［記録媒体］
　本発明に用いることができる記録媒体は、特に限定されるものではないが、前述のインクジェット記録用インクセットを用いることにより、インクの吐出安定性が良好であり、記録物の画質が向上する観点から、記録媒体は吸収性の低い・無い記録媒体であることが好ましい。
　なお、本発明において、「吸収性」とは、水性のインクに対する吸収性のことをいう。 [recoding media]
The recording medium that can be used in the present invention is not particularly limited, but by using the ink set for inkjet recording described above, the ejection stability of the ink is good, and the image quality of the recorded matter is improved. Therefore, it is preferable that the recording medium has low or no absorbency.
In the present invention, "absorbency" refers to absorbency for water-based ink.
　吸収性の低い・無い記録媒体としては、公知のプラスチックのフィルムが使用できる。具体例としては、ポリエチレンテレフタレート等のポリエステルフィルム、ポリエチレンフィルム、ポリプロピレンフィルム、ナイロン等のポリアミド系フィルム、ポリスチレンフィルム、ポリ塩化ビニルフィルム、ポリカーボネートフィルム、ポリアクリロニトリルフィルム、ポリ乳酸フィルム等の生分解性フィルム等が挙げられる。 A well-known plastic film can be used as a recording medium with low or no absorbency. Specific examples include polyester films such as polyethylene terephthalate, polyethylene films, polypropylene films, polyamide films such as nylon, polystyrene films, polyvinyl chloride films, polycarbonate films, polyacrylonitrile films, biodegradable films such as polylactic acid films, and the like. is mentioned.
　また、ガスバリアー性、防湿性、保香性などを付与するために、フィルムの片面又は両面にポリ塩化ビニリデンをコートしたものや、金属酸化物を蒸着したフィルムも好ましく用いることができる。フィルムは、未延伸フィルムでも延伸フィルムでも好ましく用いることができる。
　記録媒体の厚さは、プラスチックのフィルムの場合は、１０～１２０μｍの範囲内であることが好ましく、１２～６０μｍの範囲内であることがより好ましい。 In addition, in order to impart gas barrier properties, moisture resistance, fragrance retention properties, etc., a film coated with polyvinylidene chloride on one or both sides thereof, or a film deposited with a metal oxide can also be preferably used. The film can be preferably used whether it is an unstretched film or a stretched film.
In the case of a plastic film, the thickness of the recording medium is preferably in the range of 10-120 μm, more preferably in the range of 12-60 μm.
　また、吸収性の低い・無い記録媒体として、３ピース缶用途のブリキ板やティンフリースチール板（ＴＦＳ板、厚さ０．１～０．６μｍの範囲内)等の金属も好ましく用いられ、例えば、熱硬化性樹脂を塗工層として設けた、缶詰食品用の包装材料などに好適に用いることができる。前記缶詰食品用の包装材料は、例えば、空気や水分、光を遮断し、内部の食品を密閉するため、食品側にはエポキシ－フェノール系塗料やポリエステル系ラミネート剤が使用され、外側は、ポリエステル系、アクリル系の熱硬化性塗料が使用されるのが一般的である。 Also, as recording media with low or no absorbency, metals such as tin plates for three-piece cans and tin-free steel plates (TFS plates, thickness within the range of 0.1 to 0.6 μm) are preferably used. , can be suitably used for packaging materials for canned food, etc. provided with a thermosetting resin as a coating layer. The packaging materials for canned foods, for example, block air, moisture, and light, and seal the food inside. It is common to use acrylic or acrylic thermosetting paints.
　１）処理液付与工程
　処理液付与工程では、記録媒体表面に前述の処理液を付与する。 1) Treatment Liquid Application Process In the treatment liquid application process, the above-described treatment liquid is applied to the surface of the recording medium.
　処理液は、後述のインクと同様に、インクジェット法を用いて、記録媒体表面に付与される。インクジェット法を用いることにより、付与量を細かく制御することができ、インクの付与量に対応して、適当量の処理液を付与することができる。 The treatment liquid is applied to the surface of the recording medium using an inkjet method, similar to the ink described later. By using the inkjet method, the application amount can be finely controlled, and an appropriate amount of treatment liquid can be applied according to the application amount of the ink.
　処理液の付与量が適当量を下回る場合、インクの塗膜にひび割れが生じて画質が低下する可能性があり、処理液の付与量が適当量を上回る場合、ドットの形状の不均化や波寄りによる粒状感が発現し画質が低下する可能性がある。そのため、処理液の付与量を細かく制御することが好ましく、記録媒体の吸収性及びインクの付与量に応じて、処理液の印字率又は液滴量を変化させて処理液の付与量を制御することが好ましい。 If the amount of treatment liquid applied is less than the appropriate amount, the ink coating film may crack and image quality may deteriorate. There is a possibility that the image quality will deteriorate due to the appearance of graininess due to waves. Therefore, it is preferable to finely control the application amount of the treatment liquid, and the application amount of the treatment liquid is controlled by changing the printing rate or the droplet amount of the treatment liquid according to the absorbency of the recording medium and the application amount of the ink. is preferred.
　処理液の好適な付与量は、インク及び処理液の構成成分によって異なるが、インクの全質量に対して、１０～１００質量％の範囲内であることが好ましい。 A suitable amount of the treatment liquid to be applied varies depending on the constituents of the ink and the treatment liquid, but is preferably in the range of 10 to 100% by mass with respect to the total mass of the ink.
　２）インク付与工程
　インク付与工程では、記録媒体表面に前述のインクを付与する。 2) Ink Application Process In the ink application process, the ink described above is applied to the surface of the recording medium.
　インクは、インクジェット法を用いて、記録媒体表面に付与される。インクジェット法を用いることにより、付与量を細かく制御することができる。 The ink is applied to the surface of the recording medium using an inkjet method. By using the inkjet method, the application amount can be finely controlled.
　処理液付与工程及びインク付与工程においては、例えば、インクを装填したインクジェットヘッドを備えるプリンターを用いることができる。具体的には、デジタル信号に基づいてインクジェットヘッドのノズルからインクを液滴として吐出させた後、当該液滴を記録媒体表面に着弾させることにより、記録することができる。 In the treatment liquid applying process and the ink applying process, for example, a printer equipped with an inkjet head loaded with ink can be used. Specifically, recording can be performed by ejecting ink droplets from nozzles of an inkjet head based on a digital signal and then landing the droplets on the surface of a recording medium.
　上記インクジェットヘッドは、オンデマンド方式及びコンティニュアス方式のいずれのインクジェットヘッドでもよい。オンデマンド方式のインクジェットヘッドの例には、シングルキャビティー型、ダブルキャビティー型、ベンダー型、ピストン型、シェアーモード型及びシェアードウォール型を含む電気－機械変換方式、並びに、サーマルインクジェット型及びバブルジェット（登録商標、キヤノン社）型を含む電気－熱変換方式等が含まれる。 The inkjet head may be either an on-demand type or a continuous type. Examples of on-demand inkjet heads include electro-mechanical conversion, including single-cavity, double-cavity, bender, piston, shear mode and shared wall, and thermal inkjet and bubble jet. (registered trademark, Canon Inc.) type, and other electric-heat conversion methods.
　上記インクジェットヘッドの中では、電気－機械変換方式に用いられる電気－機械変換素子として圧電素子を用いたインクジェットヘッド（「ピエゾ型インクジェットヘッド」ともいう。）であることが好ましい。 Among the above inkjet heads, an inkjet head (also referred to as a "piezo inkjet head") using a piezoelectric element as an electro-mechanical conversion element used in an electro-mechanical conversion system is preferable.
　また、インクジェットヘッドは、スキャン方式及びシングルパス方式のいずれのインクジェットヘッドでもよいが、シングルパス方式であることが好ましい。シングルパス方式の場合には、ラインヘッド方式のインクジェットヘッドを使用することが好ましい。 In addition, the inkjet head may be either a scanning type inkjet head or a single-pass type inkjet head, but the single-pass type is preferable. In the case of the single pass method, it is preferable to use a line head type inkjet head.
　ラインヘッド方式のインクジェットヘッドとは、記録範囲の幅以上の長さを持つインクジェットヘッドのことをいう。ラインヘッド方式のインクジェットヘッドとしては、一つのヘッドで記録範囲の幅以上であるものを用いてもよいし、複数のヘッドを組み合わせて記録範囲の幅以上となるように構成してもよい。 A line head type inkjet head is an inkjet head that has a length greater than the width of the recording area. As the line head type inkjet head, a single head having a width equal to or larger than the recording range may be used, or a plurality of heads may be combined to form an ink jet head having a width equal to or larger than the recording range.
　また、複数のヘッドを、互いのノズルが千鳥配置となるように並設して、これらヘッド全体としての解像度を高くしてもよい。 Also, a plurality of heads may be arranged side by side so that their nozzles are staggered to increase the resolution of the heads as a whole.
　記録媒体の搬送速度は、例えば、１～１２０ｍ／ｍｉｎの範囲内で設定することができる。搬送速度が速いほど記録速度が速まる。本発明においては、シングルパス方式のインクジェット記録方法で適用可能な、線速５０～１２０ｍ／ｍｉｎの範囲内という非常に速い線速であっても、インクの定着性が高く、高精細な記録物を得ることができる。 The transport speed of the recording medium can be set, for example, within the range of 1 to 120 m/min. The faster the conveying speed, the faster the recording speed. In the present invention, even at a very high linear velocity in the range of 50 to 120 m/min, which is applicable to the single-pass inkjet recording method, the ink fixability is high and high-definition recorded matter is produced. can be obtained.
　３）混合液乾燥工程
　混合液乾燥工程では、記録媒体表面に付与したインク及び処理液からなる混合液を乾燥させる。 3) Mixed Liquid Drying Process In the mixed liquid drying process, the mixed liquid composed of the ink and the treatment liquid applied to the surface of the recording medium is dried.
　混合液を乾燥させることにより、主にインク及び処理液の溶剤成分である水や水溶性有機溶剤などを除去する。乾燥温度は、２２０℃以下であること好ましく、５０～１５０℃の範囲内であることが好ましい。また、乾燥時間は、特に制限はないが、十分に溶剤が除去できる時間であることが好ましい。 By drying the mixed liquid, water and water-soluble organic solvents, etc., which are the solvent components of the ink and treatment liquid, are mainly removed. The drying temperature is preferably 220°C or less, preferably in the range of 50 to 150°C. Also, the drying time is not particularly limited, but it is preferably a time during which the solvent can be sufficiently removed.
　混合液の乾燥は、例えば、乾燥炉や熱風送風機などのような非接触加熱型の乾燥装置を用いて行ってもよいし、ホットプレートや熱ローラーなどのような接触加熱型の乾燥装置を用いて行ってもよい。 The mixed liquid may be dried, for example, using a non-contact heating drying device such as a drying furnace or a hot air blower, or using a contact heating drying device such as a hot plate or a hot roller. you can go
　乾燥温度は、（ａ）乾燥炉や熱風送風機等のような非接触加熱型の乾燥装置を用いる場合には、炉内温度又は熱風温度等の雰囲気温度、（ｂ）ホットプレートや熱ローラーなどのような接触加熱型の乾燥装置を用いる場合には、接触加熱部の温度、また、（ｃ）被乾燥面の表面温度、から選ばれるいずれか一つを、混合液乾燥工程の全期間において測定することにより得られる。なお、乾燥温度は、（ｃ）被乾燥面の表面温度を測定することが好ましい。 The drying temperature is (a) when using a non-contact heating drying device such as a drying furnace or a hot air blower, the temperature in the furnace or the atmosphere temperature such as the hot air temperature, and (b) the temperature of the hot plate, the heat roller, etc. When using such a contact heating type drying apparatus, the temperature of the contact heating part, or (c) the surface temperature of the surface to be dried, is measured during the entire period of the mixed liquid drying process. obtained by As for the drying temperature, it is preferable to measure (c) the surface temperature of the surface to be dried.
　≪インクジェット記録装置の概要≫
　本発明のインクジェット記録装置は、本発明のインクジェット記録用インクセットを用い、当該インクジェット記録装置が、インク用インクジェットヘッド及び処理液用インクジェットヘッドを有し、当該インク用インクジェットヘッド及び当該処理液用インクジェットヘッドが、同一キャリッジに搭載されている、又は、当該インク用インクジェットヘッド及び当該処理液用インクジェットヘッドが、それぞれ別のキャリッジに搭載され、乾燥機構を挟むことなくキャリッジが隣接していることを特徴とする。 <<Overview of Inkjet Recording Apparatus>>
The inkjet recording apparatus of the present invention uses the inkjet recording ink set of the present invention, the inkjet recording apparatus has an inkjet head for ink and an inkjet head for treatment liquid, and the inkjet head for ink and the inkjet head for treatment liquid. The heads are mounted on the same carriage, or the inkjet head for ink and the inkjet head for treatment liquid are mounted on separate carriages, and the carriages are adjacent to each other without a drying mechanism in between. and
　本発明のインクジェット記録用インクセットは、ウェット・オン・ウェット方式を用いることができ、例えば、処理液として前処理液を用いる場合、処理液を乾燥させる工程が不要であり、処理液を吐出した後すぐにインクを吐出することができる。そのため、インク用インクジェットヘッド及び処理液用インクジェットヘッドを同一キャリッジに搭載することができる。 The ink set for inkjet recording of the present invention can use a wet-on-wet method. Ink can be ejected immediately thereafter. Therefore, the inkjet head for ink and the inkjet head for treatment liquid can be mounted on the same carriage.
　また、インク用インクジェットヘッド及び処理液用インクジェットヘッドを、それぞれ別のキャリッジに搭載した場合においても、処理液を乾燥させる工程が不要であるため、それぞれのキャリッジ間に乾燥機構を挟む必要がない。そのため、本発明のインクジェット記録装置は、装置を小型化することができ、また、記録時間を短縮させることができる。 Also, even if the inkjet head for the ink and the inkjet head for the treatment liquid are mounted on different carriages, there is no need to dry the treatment liquid, so there is no need to interpose a drying mechanism between the carriages. Therefore, the inkjet recording apparatus of the present invention can be downsized and the recording time can be shortened.
　以下、本発明のインクジェット記録装置の一例について説明する。 An example of the inkjet recording apparatus of the present invention will be described below.
　［インクジェット記録装置］
　インクジェット記録装置２００は、図１に示すように、給紙部２１０と、画像記録部２２０と、排紙部２３０と、インクの供給手段としてのインク循環装置８（図３参照。）と、制御部（図４参照。）等を備える。インクジェット記録装置２００は、給紙部２１０に格納された記録媒体Ｍを画像記録部２２０に搬送し、画像記録部２２０で記録媒体Ｍに画像を形成し、画像が形成された記録媒体Ｍを排紙部２３０に搬送する。 [Inkjet recording device]
As shown in FIG. 1, the inkjet recording apparatus 200 includes a paper feed section 210, an image recording section 220, a paper discharge section 230, an ink circulation device 8 (see FIG. 3) as ink supply means, and a controller. section (see FIG. 4) and the like. The inkjet recording apparatus 200 conveys the recording medium M stored in the paper feeding section 210 to the image recording section 220, forms an image on the recording medium M in the image recording section 220, and ejects the recording medium M on which the image is formed. It is conveyed to the paper section 230 .
　給紙部２１０は、記録媒体Ｍを格納する給紙トレー２１１と、給紙トレー２１１から画像記録部２２０に記録媒体Ｍを搬送して供給する媒体供給部２１２とを有する。媒体供給部２１２は、内側が２本のローラーにより支持された輪状のベルトを備え、このベルト上に記録媒体Ｍを載置した状態でローラーを回転させることで記録媒体Ｍを給紙トレー２１１から画像記録部２２０へ搬送する。 The paper feed unit 210 has a paper feed tray 211 that stores the recording medium M, and a medium supply unit 212 that conveys and supplies the recording medium M from the paper feed tray 211 to the image recording unit 220 . The medium supply unit 212 includes a ring-shaped belt whose inner side is supported by two rollers, and the recording medium M is fed from the paper feed tray 211 by rotating the rollers while the recording medium M is placed on the belt. It is conveyed to the image recording section 220 .
　画像記録部２２０は、搬送ドラム２２１と、受け渡しユニット２２２と、加熱部２２３と、キャリッジ２２４と、定着部２２５と、デリバリー部２２６等を有する。 The image recording section 220 has a conveying drum 221, a delivery unit 222, a heating section 223, a carriage 224, a fixing section 225, a delivery section 226, and the like.
　搬送ドラム２２１は、円柱面をなしており、その外周面が記録媒体Ｍを載置させる搬送面となっている。搬送ドラム２２１は、その搬送面上に記録媒体Ｍを保持した状態で図１中の矢印の向きに回転することによって、記録媒体Ｍを搬送面に沿って搬送する。また、搬送ドラム２２１は、爪部及び吸気部（図示省略）を備え、爪部により記録媒体Ｍの端部を押さえ、かつ吸気部により記録媒体Ｍを搬送面に吸い寄せることで、搬送面上に記録媒体Ｍを保持している。 The transport drum 221 has a cylindrical surface, and its outer peripheral surface serves as a transport surface on which the recording medium M is placed. The conveying drum 221 conveys the recording medium M along the conveying surface by rotating in the direction of the arrow in FIG. 1 while holding the recording medium M on the conveying surface. In addition, the conveying drum 221 includes a claw portion and a suction portion (not shown). holds the recording medium M.
　受け渡しユニット２２２は、給紙部２１０の媒体供給部２１２と搬送ドラム２２１との間の位置に設けられ、媒体供給部２１２から搬送された記録媒体Ｍの一端をスイングアーム部２２２ａで保持して取り上げ、受け渡しドラム２２２ｂを介して搬送ドラム２２１に引き渡す。 The transfer unit 222 is provided between the medium supply unit 212 of the paper supply unit 210 and the transport drum 221, and picks up the recording medium M transported from the medium supply unit 212 by holding one end of the recording medium M transported from the medium supply unit 212 with the swing arm 222a. , to the transport drum 221 via the delivery drum 222b.
　加熱部２２３は、受け渡しドラム２２２ｂの配置位置とキャリッジ２２４の配置位置との間に設けられ、搬送ドラム２２１により搬送される記録媒体Ｍが所定の温度範囲内の温度となるように当該記録媒体Ｍを加熱する。加熱部２２３は、例えば、赤外線ヒーター等を有し、制御部（図示省略）から供給される制御信号に基づいて赤外線ヒーターに通電してヒーターを発熱させる。 The heating unit 223 is provided between the arrangement position of the delivery drum 222b and the arrangement position of the carriage 224, and heats the recording medium M conveyed by the conveying drum 221 so that the temperature of the recording medium M is within a predetermined temperature range. to heat. The heating unit 223 has, for example, an infrared heater or the like, and energizes the infrared heater based on a control signal supplied from a control unit (not shown) to cause the heater to generate heat.
　本発明において、「キャリッジ」とは、インクジェットヘッドを支持するもののことをいう。キャリッジは、インクジェットヘッドを支持することができるものであれば、特に制限されず、キャリッジはインクタンクを搭載していても、していなくてもよい。 In the present invention, the "carriage" refers to what supports the inkjet head. The carriage is not particularly limited as long as it can support the inkjet head, and the carriage may or may not be equipped with an ink tank.
　キャリッジ２２４内に配置されたインクジェットヘッド１００は、画像データに基づいて、記録媒体Ｍが保持された搬送ドラム２２１の回転に応じた適切なタイミングで記録媒体Ｍに対してインクを吐出して画像を形成する。キャリッジ２２４は、インク吐出面が搬送ドラム２２１に対向して所定の距離を置いて配置される。本実施形態のインクジェット記録装置２００では、例えば、イエロー（Ｙ）、マゼンタ（Ｍ）、シアン（Ｃ）、ブラック（Ｋ）の４色のインクにそれぞれ対応する四つのキャリッジ２２４が、記録媒体Ｍの搬送方向上流側からＹ、Ｍ、Ｃ、Ｋの色の順に所定の間隔で並ぶように配列されている。 The inkjet head 100 arranged in the carriage 224 ejects ink onto the recording medium M at an appropriate timing according to the rotation of the transport drum 221 holding the recording medium M based on the image data to form an image. Form. The carriage 224 is arranged with an ink ejection surface facing the transport drum 221 at a predetermined distance. In the inkjet recording apparatus 200 of the present embodiment, for example, four carriages 224 corresponding to four colors of ink, yellow (Y), magenta (M), cyan (C), and black (K), move the recording medium M. The colors are arranged in the order of Y, M, C, and K from the upstream side in the transport direction so as to be arranged at predetermined intervals.
　キャリッジ２２４では、例えば、図２に示すように、前後方向に隣接する一対のインクジェットヘッド１００の組が、前後方向について異なる位置に千鳥状に配置されている。 In the carriage 224, for example, as shown in FIG. 2, a pair of inkjet heads 100 adjacent in the front-rear direction are arranged in a zigzag pattern at different positions in the front-rear direction.
　通常、インクジェット記録において、インクを記録媒体上に固定化（ピニング）させる手法として、インク又は記録媒体の加熱によるインクの乾燥が用いられる。ただし、この方法を千鳥配置されたインクジェットヘッドに適用すると、インクの液滴が着弾するタイミングにズレが生じて、液滴の乾燥時間差による色ムラが発生しやすい。 In inkjet recording, drying of the ink by heating the ink or the recording medium is usually used as a method of fixing (pinning) the ink on the recording medium. However, if this method is applied to an inkjet head arranged in a zigzag arrangement, the timing at which the ink droplets land is shifted, and color unevenness is likely to occur due to the difference in the drying time of the droplets.
　しかし、本発明のインクセットは、処理液を用いてインクを固定化しており、乾燥によるピニングが不要のため、乾燥の時間差による色ムラや画質のムラが生じにくい。また、本発明では、インクジェット記録によるウェット・オン・ウェット方式を採用しているが、処理液とインクの着弾するタイミングにズレが生じても画質への影響は少なく、良好な画質が得られるため、千鳥配置されたインクジェットヘッドにおいても好適に用いることができる。 However, in the ink set of the present invention, the ink is fixed using the treatment liquid, and pinning due to drying is unnecessary, so color unevenness and image quality unevenness due to drying time differences are less likely to occur. In addition, although the present invention employs a wet-on-wet method using inkjet recording, even if there is a difference in the landing timing of the treatment liquid and the ink, it has little effect on the image quality, and good image quality can be obtained. , and an ink jet head arranged in a zigzag manner.
　また、本実施形態においては、インクジェット記録装置２００は、ラインヘッドを用いた１パス描画方式の画像記録を行うインクジェット記録装置２００であり、キャリッジ２２４は、画像の記録時には搬送ドラム２２１の回転軸に対する位置が固定されて用いられる。ただし、本発明のインクジェット記録装置は、スキャン方式であってもよく、スキャン方式では、キャリッジが副走査方向に往復移動する。 Further, in this embodiment, the inkjet recording apparatus 200 is an inkjet recording apparatus 200 that performs image recording by a one-pass drawing method using a line head, and the carriage 224 is moved relative to the rotating shaft of the conveying drum 221 during image recording. Position is fixed and used. However, the ink jet recording apparatus of the present invention may be of a scanning type, in which the carriage reciprocates in the sub-scanning direction.
　定着部２２５は、記録媒体Ｍ上に吐出されたインクと処理液の混合液を乾燥させて定着させる。 The fixing unit 225 dries and fixes the mixed liquid of the ink and the treatment liquid ejected onto the recording medium M.
　デリバリー部２２６は、内側が２本のローラーにより支持された輪状のベルトを有するベルトループ２２６ｂと、記録媒体Ｍを搬送ドラム２２１からベルトループ２２６ｂに受け渡す円筒状の受け渡しドラム２２６ａとを有し、受け渡しドラム２２６ａにより搬送ドラム２２１からベルトループ２２６ｂ上に受け渡された記録媒体Ｍをベルトループ２２６ｂにより搬送して排紙部２３０に送出する。 The delivery unit 226 has a belt loop 226b having a ring-shaped belt whose inside is supported by two rollers, and a cylindrical delivery drum 226a that delivers the recording medium M from the transport drum 221 to the belt loop 226b. The recording medium M transferred from the conveying drum 221 onto the belt loop 226b by the transfer drum 226a is conveyed by the belt loop 226b and delivered to the paper ejection section 230. FIG.
　排紙部２３０は、デリバリー部２２６により画像記録部２２０から送り出された記録媒体Ｐが載置される板状の排紙トレー２３１を有する。 The paper discharge section 230 has a plate-shaped paper discharge tray 231 on which the recording medium P delivered from the image recording section 220 by the delivery section 226 is placed.
　［インク循環装置］
　本発明のインクジェット記録用インクセットは、循環機構を有するインクジェット記録装置から吐出されることが好ましい。本発明に係るインクのうち、比較的チキソ性の高いインクは、インクを循環させることにより、インクの粘度の上昇を抑制でき、良好な吐出安定性が得られる。 [Ink circulation device]
The ink set for inkjet recording of the present invention is preferably discharged from an inkjet recording apparatus having a circulation mechanism. Among the inks according to the present invention, inks with relatively high thixotropic properties can suppress an increase in the viscosity of the ink by circulating the ink, and good ejection stability can be obtained.
　インク循環装置８は、インクジェットヘッド１００内の圧力室（図示省略）から個別インク排出路（図示省略）へのインクの循環流を発生させるためのインクの供給手段である。インク循環装置８は、供給用サブタンク８１、循環用サブタンク８２及びメインタンク８３等によって構成されている（図３参照。）。 The ink circulation device 8 is an ink supply means for generating a circulation flow of ink from pressure chambers (not shown) in the inkjet head 100 to individual ink discharge paths (not shown). The ink circulation device 8 is composed of a supply sub-tank 81, a circulation sub-tank 82, a main tank 83, and the like (see FIG. 3).
　供給用サブタンク８１は、マニホールド５のインク貯留部５１に供給するためのインクが充填されており、インク流路８４によって第１インクポート５３に接続されている。
　循環用サブタンク８２は、マニホールド５の排出用液室（図示省略）から排出されたインクが充填されており、インク流路８５によって第４インクポート５６に接続されている。
　また、供給用サブタンク８１と循環用サブタンク８２は、インクジェットヘッド１００のノズル面（以下、「位置基準面」ともいう。）に対して、上下方向（重力方向）に異なる位置に設けられている。これによって、当該位置基準面と供給用サブタンク８１の水頭差による圧力Ｐ１と、当該位置基準面と循環用サブタンク８２との水頭差による圧力Ｐ２が生じている。
　また、供給用サブタンク８１と循環用サブタンク８２は、インク流路８６で接続されている。そして、ポンプ８８によって加えられた圧力によって、循環用サブタンク８２から供給用サブタンク８１にインクを戻すことができる。 The supply sub-tank 81 is filled with ink to be supplied to the ink reservoir 51 of the manifold 5 and is connected to the first ink port 53 by an ink flow path 84 .
The circulation sub-tank 82 is filled with ink discharged from a discharge liquid chamber (not shown) of the manifold 5 and is connected to the fourth ink port 56 by an ink channel 85 .
The supply sub-tank 81 and the circulation sub-tank 82 are provided at different positions in the vertical direction (gravitational direction) with respect to the nozzle surface of the inkjet head 100 (hereinafter also referred to as the "position reference plane"). As a result, a pressure P1 due to a water head difference between the position reference plane and the supply sub-tank 81 and a pressure P2 due to a water head difference between the position reference plane and the circulation sub-tank 82 are generated.
The supply sub-tank 81 and the circulation sub-tank 82 are connected by an ink flow path 86 . Then, the pressure applied by the pump 88 can return the ink from the circulation sub-tank 82 to the supply sub-tank 81 .
　メインタンク８３は、供給用サブタンク８１に供給するためのインクが充填されており、インク流路８７によって供給用サブタンク８１に接続されている。そして、ポンプ８９によって加えられた圧力によって、メインタンク８３から供給用サブタンク８１にインクを供給することができる。 The main tank 83 is filled with ink to be supplied to the supply sub-tank 81 and is connected to the supply sub-tank 81 by an ink flow path 87 . Ink can be supplied from the main tank 83 to the supply sub-tank 81 by the pressure applied by the pump 89 .
　また、各サブタンク内のインク充填量と、各サブタンクの上下方向（重力方向）の位置とを適宜変更することによって、圧力Ｐ１及び圧力Ｐ２を調整することができる。そして、圧力Ｐ１及び圧力Ｐ２の圧力差によって、適宜の循環流速で、インクジェットヘッド１００内のインクを循環できる。これにより、インクジェットヘッドのヘッドチップ内に発生した気泡や異物等を除去し、ノズルの詰まりや、吐出不良等を抑制することができる。 Also, the pressure P1 and the pressure P2 can be adjusted by appropriately changing the amount of ink filled in each sub-tank and the position of each sub-tank in the vertical direction (the direction of gravity). The pressure difference between the pressures P1 and P2 allows the ink in the inkjet head 100 to circulate at an appropriate circulation flow rate. As a result, it is possible to remove air bubbles, foreign matter, and the like generated in the head chip of the inkjet head, thereby suppressing nozzle clogging, ejection failure, and the like.
　なお、インク循環装置８の一例として、水頭差によってインクの循環を制御する方法を説明したが、インクの循環流を発生できる構成であれば、当然適宜変更可能である。 As an example of the ink circulation device 8, the method of controlling the circulation of ink by using the difference in water head has been described, but it is naturally possible to make appropriate modifications as long as the configuration is capable of generating a circulating flow of ink.
　また、インク内で色材が沈殿するのを抑制できる観点から、インクの循環機構を両方向循環とすることが好ましい。ポンプの駆動方向を正方向と逆方向で切り替えることにより、インクの循環流の方向を替えることができる。 In addition, from the viewpoint of suppressing the precipitation of the coloring material in the ink, it is preferable that the ink circulation mechanism is bidirectional circulation. By switching the driving direction of the pump between the forward direction and the reverse direction, the direction of the circulating flow of ink can be changed.
　図４は、インクジェット記録装置の主要な機能構成を示すブロック図である。
　インクジェット記録装置２００は、前述のとおり、給紙部２１０と、画像記録部２２０（搬送ドラム２２１、受け渡しユニット２２２、加熱部２２３、キャリッジ２２４、定着部２２５及びデリバリー部２２６）と、排紙部２３０と、インクの供給手段としてのインク循環装置８と、制御部２４０等を備える。 FIG. 4 is a block diagram showing the main functional configuration of the inkjet printing apparatus.
As described above, the inkjet recording apparatus 200 includes the paper feeding section 210, the image recording section 220 (the conveying drum 221, the transfer unit 222, the heating section 223, the carriage 224, the fixing section 225, and the delivery section 226), and the paper discharging section 230. , an ink circulation device 8 as ink supply means, a controller 240 and the like.
　制御部２４０は、インクジェット記録装置２００を構成する各部と接続されており、インクジェット記録装置２００を構成する各部を制御する。制御部２４０は、ＣＰＵ２４１、ＲＡＭ２４２及びＲＯＭ２４３等を有する。ＣＰＵ２４１は、ＲＯＭ２４３等の記憶装置から処理内容に応じた各種のプログラムやデータ等を読み出して実行し、実行された処理内容に応じてインクジェット記録装置２００の各部の動作を制御する。ＲＡＭ２４２は、ＣＰＵ２４１により処理される各種のプログラムやデータ等を一時的に記憶する。ＲＯＭ２４３は、ＣＰＵ２４１等により読み出される各種のプログラムやデータ等を記憶する。 The control section 240 is connected to each section that configures the inkjet recording apparatus 200 and controls each section that configures the inkjet recording apparatus 200 . The control unit 240 has a CPU 241, a RAM 242, a ROM 243, and the like. The CPU 241 reads and executes various programs, data, and the like according to the content of processing from a storage device such as the ROM 243, and controls the operation of each unit of the inkjet recording apparatus 200 according to the content of the executed processing. The RAM 242 temporarily stores various programs and data processed by the CPU 241 . The ROM 243 stores various programs and data read by the CPU 241 and the like.
　制御部２４０は、インクジェット記録装置２００のインク循環装置８に対して、次のような処理を行う。
　例えば、制御部２４０は、インクジェットヘッドのノズルに連通する流路Ｒを流れるインク流量（循環流量Ｑ）、すなわち循環差圧ΔＰを制御することにより、当該ノズルに連通する流路Ｒの平均せん断速度を調整することができる。流路Ｒの平均せん断速度は、１００［１／ｓ］以上であることが好ましい。 The control unit 240 performs the following processing on the ink circulation device 8 of the inkjet recording device 200 .
For example, the control unit 240 controls the flow rate (circulation flow rate Q) of ink flowing through the flow path R communicating with the nozzles of the inkjet head, that is, the circulation differential pressure ΔP, so that the average shear velocity of the flow path R communicating with the nozzle is can be adjusted. The average shear rate of the flow path R is preferably 100 [1/s] or more.
　詳しくは、インク循環装置８のポンプ８８に加えられる圧力や、サブタンク８１及び８２内のインク充填量と、サブタンク８１及び８２の上下方向（重力方向）の位置とを適宜変更することによって圧力Ｐ１及び圧力Ｐ２を調整し、圧力Ｐ１及び圧力Ｐ２の圧力差（循環差圧ΔＰ）によって循環流量Ｑを制御する。循環差圧ΔＰは、５～３０ｋＰａの範囲内であることが好ましい。 More specifically, the pressure P1 and the pressure P1 and the The pressure P2 is adjusted, and the circulation flow rate Q is controlled by the pressure difference (circulation differential pressure ΔP) between the pressures P1 and P2. The circulation differential pressure ΔP is preferably within the range of 5 to 30 kPa.
　≪記録物≫
　本発明のインクジェット記録用インクセットを用いて形成される記録物は、記録媒体表面に、インク及び処理液からなる混合液を用いて形成されるインク層を有することが好ましい。また、必要に応じて、記録媒体とインク層との間に他の機能性層を有していてもよく、インク層の上層に、例えばラミネート接着層を介して非吸収性のフィルム基材等を貼合してもよい。 ≪Records≫
A recorded matter formed using the ink set for inkjet recording of the present invention preferably has an ink layer formed using a mixture of ink and treatment liquid on the surface of the recording medium. In addition, if necessary, another functional layer may be provided between the recording medium and the ink layer. may be pasted together.
　上記記録物としては、例えば、金属基材上に、熱硬化性樹脂を含有する層、上記インク層及び熱硬化性樹脂を含有する層を、この順に積層することが好ましく、具体的には、缶詰食品、レトルト食品や飲料等を包装する包装材料等が挙げられる。 As the recorded matter, for example, a layer containing a thermosetting resin, the ink layer, and a layer containing a thermosetting resin are preferably laminated in this order on a metal substrate. Examples include packaging materials for packaging canned foods, retort-packed foods, beverages, and the like.
　吸収性の低い・無い記録媒体としては、例えば、ＰＥＴフィルム（ＦＥ２００１、フタムラ化学社製）等が挙げられ、当該ＰＥＴフィルムに、本発明のインクジェット記録用インクセットを用いて記録物を形成することにより、画質が向上した記録物が得られる。 Recording media with low or no absorbency include, for example, PET film (FE2001, manufactured by Futamura Chemical Co., Ltd.). Thus, a recorded matter with improved image quality can be obtained.
　また、ブリキ基材上に熱硬化性樹脂（例えば、ＴＷ－１４０７シリーズ　Ｔ＆Ｋ　ＴＯＫＡ製）をローラー塗布して熱硬化性樹脂層（ベースコート）を形成し、その上に、本発明のインクジェット記録用インクセットにより記録し、インク層を形成する。次いで、熱硬化性樹脂（例えば 、ＡＸ－１０シリーズ　Ｔ＆Ｋ　ＴＯＫＡ製）をローラー塗布して熱硬化性樹脂層（トップコート）を形成し、加熱硬化、乾燥させて、缶詰食品用包装材料を得ることができる。 In addition, a thermosetting resin (for example, TW-1407 series manufactured by T&K TOKA) is roller-coated on a tin substrate to form a thermosetting resin layer (base coat), and the ink for inkjet recording of the present invention is applied thereon. Recording is performed by setting to form an ink layer. Next, a thermosetting resin (for example, AX-10 series manufactured by T&K Toka) is roller-coated to form a thermosetting resin layer (top coat), which is then cured by heating and dried to obtain a packaging material for canned food. can be done.
　以下、実施例を挙げて本発明を具体的に説明するが、本発明はこれらに限定されるものではない。なお、実施例において「部」又は「％」の表示を用いるが、特に断りがない限り「質量部」又は「質量％」を表す。
　また、下記実施例において、特記しない限り操作は室温（２５℃）で行われた。 EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these. In the examples, "parts" or "%" are used, but "mass parts" or "mass%" are indicated unless otherwise specified.
Also, in the following examples, the operations were carried out at room temperature (25° C.) unless otherwise specified.
　≪インク（組成物Ａ）の調製及び評価≫
　インク組成物１Ａ～３７Ａを調製し、評価を行った。 <<Preparation and Evaluation of Ink (Composition A)>>
Ink compositions 1A to 37A were prepared and evaluated.
　［顔料分散体Ｄ１～Ｄ３の調製］
　下記のとおり、顔料分散体Ｄ１～Ｄ３を調製した。各顔料分散体に含まれる顔料粒子の平均粒径は、Ｄ１：１５０ｎｍ、Ｄ２：１００ｎｍ、Ｄ３：２２０ｎｍであった。なお、平均粒径の測定はマルバルーン社製「ゼータサイザー　Ｎａｎｏ　Ｓ－９０」により行った。 [Preparation of pigment dispersions D1 to D3]
Pigment Dispersions D1-D3 were prepared as follows. The average particle size of the pigment particles contained in each pigment dispersion was D1: 150 nm, D2: 100 nm, and D3: 220 nm. The average particle size was measured using "Zetasizer Nano S-90" manufactured by Maruballoon.
　（顔料分散体Ｄ１の調製）
　下記成分を混合し、プレミックスした後、０．３ｍｍのジルコニアビーズを体積率で５０％充填したビーズミルを用いて分散し、顔料の含有量が２０質量％の顔料分散液Ｄ１を調製した。 (Preparation of Pigment Dispersion D1)
After mixing and premixing the following components, the mixture was dispersed using a bead mill filled with 50% by volume of 0.3 mm zirconia beads to prepare a pigment dispersion D1 having a pigment content of 20% by mass.
　マゼンタ顔料（ピグメントレッド１２２とピグメントバイオレット１９の混晶）
　　　　　　　　　　　　　　　　　　　　　　　　　　　　２０質量％
　顔料分散剤（ジメチルアミノエタノール中和されたカルボキシ基を有するアクリル系分散剤（ＢＡＳＦ社製、ジョンクリル（登録商標）８１９、酸価７５ｍｇＫＯＨ／ｇ、固形分２０質量％））
　　　　　　　　　　　　　　　　　　　　　　　　　　　　　８質量％
　プロピレングリコール　　　　　　　　　　　　　　　　　２０質量％
　防黴剤（ロンザ社製、プロキセルＧＸＬ（Ｓ））　　　　０．１質量％
　イオン交換水　　　　　　　　（残部；全量が１００質量％となる量） Magenta pigment (mixed crystal of Pigment Red 122 and Pigment Violet 19)
20% by mass
Pigment dispersant (acrylic dispersant having a carboxyl group neutralized with dimethylaminoethanol (manufactured by BASF, Joncryl (registered trademark) 819, acid value 75 mgKOH/g, solid content 20% by mass))
8% by mass
Propylene glycol 20% by mass
Antifungal agent (Proxel GXL (S) manufactured by Lonza) 0.1% by mass
Ion-exchanged water (Remainder; amount to make the total amount 100% by mass)
　（顔料分散体Ｄ２の調製）
　顔料分散体Ｄ１のマゼンタ顔料をシアン顔料（ピグメントブルー１５：３）２０質量％に変更した以外は同様にして顔料分散体Ｄ２を調製した。 (Preparation of Pigment Dispersion D2)
Pigment Dispersion D2 was prepared in the same manner as Pigment Dispersion D1, except that the magenta pigment of Pigment Dispersion D1 was changed to cyan pigment (pigment blue 15:3) at 20% by weight.
　（顔料分散体Ｄ３の調製）
　下記成分を混合し、プレミックスした後、０．３ｍｍのジルコニアビーズを体積率で５０％充填したビーズミルを用いて分散し、顔料の含有量が４０質量％の顔料分散液Ｄ３を調製した。 (Preparation of Pigment Dispersion D3)
After mixing and premixing the following components, the mixture was dispersed using a bead mill filled with 50% by volume of 0.3 mm zirconia beads to prepare a pigment dispersion D3 having a pigment content of 40% by mass.
　酸化チタン顔料　　　　　　　　　　　　　　　　　　　　４０質量％
　顔料分散剤（ジョンクリル（登録商標）８１９、酸価７５ｍｇＫＯＨ／ｇ、固形分２０質量％、ＢＡＳＦ社製）
　　　　　　　　　　　　　　　　　　　　　　　　　　　　　４質量％
　プロピレングリコール　　　　　　　　　　　　　　　　　２０質量％
　防黴剤（ロンザ社製、プロキセルＧＸＬ（Ｓ））　　　　０．１質量％
　イオン交換水　　　　　　　　（残部；全量が１００質量％となる量） Titanium oxide pigment 40% by mass
Pigment dispersant (Joncryl (registered trademark) 819, acid value 75 mgKOH/g, solid content 20% by mass, manufactured by BASF)
4% by mass
Propylene glycol 20% by mass
Antifungal agent (Proxel GXL (S) manufactured by Lonza) 0.1% by mass
Ion-exchanged water (Remainder; amount to make the total amount 100% by mass)
　［組成物１Ａの調製］
　下記成分を混合し、得られた混合液を１μｍのフィルターにより濾過して組成物１Ａを調製した。濾過前後で実質的な組成変化はなかった。 [Preparation of composition 1A]
The following components were mixed, and the resulting mixture was filtered through a 1 μm filter to prepare composition 1A. There was no substantial compositional change before and after filtration.
　顔料分散体Ｄ１　　　　　　　　　　　　　　　　　　　　２０質量％
　　　　　　　　　　　　　　　　　　　　　（固形分として４質量％）
　増粘剤ａ（ビックケミー社製、ＢＹＫ（登録商標）－４２５）
　　　　　　　　　　　　　　　　　　　　　　　　　　　　　１質量％
　樹脂微粒子分散体Ｐ１（添加量は、組成物１Ａ中において樹脂微粒子（固形分）が５質量％となるように調整）
　プロピレングリコール　　　　　　　　　　　　　　　　　１７質量％
　グリセリン　　　　　　　　　　　　　　　　　　　　　　　５質量％
　界面活性剤（ＴＥＧＯ（登録商標）ＷＥＴ－ＫＬ２４５、エボニック社製）
　　　　　　　　　　　　　　　　　　　　　　　　　　　　　１質量％
　防黴剤（プロキセルＧＸＬ（Ｓ）、ロンザ社製）　　　　０．１質量％
　イオン交換水　　　　　　　　（残部；全量が１００質量％となる量） Pigment dispersion D1 20% by mass
(4% by mass as solid content)
Thickener a (manufactured by BYK-Chemie, BYK (registered trademark)-425)
1% by mass
Resin fine particle dispersion P1 (the amount added is adjusted so that the resin fine particles (solid content) is 5% by mass in composition 1A)
Propylene glycol 17% by mass
Glycerin 5% by mass
Surfactant (TEGO (registered trademark) WET-KL245, manufactured by Evonik)
1% by mass
Antifungal agent (Proxel GXL (S), manufactured by Lonza) 0.1% by mass
Ion-exchanged water (Remainder; amount to make the total amount 100% by mass)
　［組成物２Ａ～３７Ａの調製］
　組成物１Ａの調製において、増粘剤、顔料分散体、有機溶剤、樹脂及び界面活性剤の種類及び添加量を下記表Ｉ及びIIに記載のとおりに変更した以外は同様にして、組成物２Ａ～３７Ａを調製した。表Ｉ及びII内の増粘剤、顔料分散体、有機溶剤、樹脂、界面活性剤及び防黴剤における数値は、組成物Ａの全質量に対する割合を表し、「－」の箇所は該当する成分を含有しないことを示す。 [Preparation of Compositions 2A-37A]
Composition 2A was prepared in the same manner as in the preparation of composition 1A, except that the types and amounts of the thickener, pigment dispersion, organic solvent, resin and surfactant were changed as shown in Tables I and II below. ~37A was prepared. Numerical values for thickeners, pigment dispersions, organic solvents, resins, surfactants, and antifungal agents in Tables I and II represent the percentage of the total mass of composition A, and the "-" indicates the corresponding component. indicates that it does not contain
　また、表Ｉ及びII内の「増粘剤比率」における数値は、色材の添加量（３Ａ：８質量％、３３Ａ：１０質量％、３４Ａ：３質量％、その他：４質量％）に対する増粘剤の添加量の割合を表し、「有機溶剤合計量」における数値は、組成物Ａの全質量に対する、有機溶剤ａ～ｅ及び顔料分散体に含まれる有機溶剤の合計量の割合を表す。
　なお、表Ｉ及びII内において、数値の単位は全て、［質量％］である。 In addition, the numerical values in the "thickening agent ratio" in Tables I and II are the amount of coloring material added (3A: 8% by mass, 33A: 10% by mass, 34A: 3% by mass, others: 4% by mass). The ratio of the added amount of the sticky agent is represented, and the numerical value in the "organic solvent total amount" represents the ratio of the total amount of the organic solvents a to e and the organic solvent contained in the pigment dispersion with respect to the total mass of the composition A.
In addition, in Tables I and II, all units of numerical values are [% by mass].
　［組成物１Ｂ～３７Ｂの調製］
　組成物１Ａ～３７Ａの調製において、増粘剤を純水に変更した以外は同様にして、組成物１Ｂ～３７Ｂを調製した。なお、３６Ｂは、３６Ａと同一の成分及び添加量であった。 [Preparation of Compositions 1B-37B]
Compositions 1B to 37B were prepared in the same manner as in the preparation of compositions 1A to 37A, except that the thickener was changed to pure water. In addition, 36B was the same component and addition amount as 36A.
　なお、表Ｉ及びII内の各成分については、以下のとおりである。
　＜増粘剤＞
　ａ：ＢＹＫ（登録商標）－４２５（ビックケミー社製）
　ｂ：モビニール（登録商標）６７６３（ジャパンコーティングレジン社製）
　ｃ：Ｄｉｓｐｅｒｂｙｋ１９３（ビックケミー社製）
　ｄ：ジョンクリル（登録商標）ＪＤＸ－６５００（ＢＡＳＦ社製）
　ｅ：ラポナイト（ビックケミー社製）
　ｆ：バイロナール（登録商標）ＭＤ１２００（東洋紡社製）
　ｇ：ダイヤミッドＯ－２００（三菱ケミカル社製）
　＜有機溶剤＞
　ａ：プロピレングリコール
　ｂ：１，２－ペンタンジオール
　ｃ：１，２－ヘキサンジオール
　ｄ：２－メチル－１，３－プロパンジオール
　ｅ：グリセリン
　＜樹脂＞
　ａ：エバファノール（登録商標）ＨＡ－５６０（日華化学社製）
　ｂ：バイロナール（登録商標）ＭＤ２０００（東洋紡社製）
　ｃ：モビニール（登録商標）６９６９Ｄ（ジャパンコーティングレジン社製）
　＜界面活性剤＞
　ａ：ポリエーテル変性シリコーン界面活性剤（ＴＥＧＯ（登録商標）ＷＥＴ－ＫＬ２４５、エボニック社製）
　ｂ：アセチレングリコール系界面活性剤（オルフィンＥ１０１０、日信化学工業社製）
　ｃ：シリコーン変性界面活性剤（ＫＦ－３５１Ａ、信越シリコーン社製）
　ｄ：ポリエーテル変性シリコーン界面活性剤（ＴＥＧＯ（登録商標）ＷＥＴ－２５０、エボニック社製）
　ｅ：ポリエーテル変性シリコーン界面活性剤（ＢＹＫ（登録商標）－３４５０、ビックケミー社製）
　＜防黴剤＞
　プロキセルＧＸＬ（Ｓ）（ロンザ社製） In addition, each component in Tables I and II is as follows.
<Thickener>
a: BYK (registered trademark) -425 (manufactured by BYK Chemie)
b: Movinyl (registered trademark) 6763 (manufactured by Japan Coating Resin Co., Ltd.)
c: Disperbyk193 (manufactured by BYK-Chemie)
d: Joncryl (registered trademark) JDX-6500 (manufactured by BASF)
e: Laponite (manufactured by BYK-Chemie)
f: Vylonal (registered trademark) MD1200 (manufactured by Toyobo Co., Ltd.)
g: Diamid O-200 (manufactured by Mitsubishi Chemical Corporation)
<Organic solvent>
a: propylene glycol b: 1,2-pentanediol c: 1,2-hexanediol d: 2-methyl-1,3-propanediol e: glycerin <resin>
a: Evaphanol (registered trademark) HA-560 (manufactured by Nicca Chemical Co., Ltd.)
b: Vylonal (registered trademark) MD2000 (manufactured by Toyobo Co., Ltd.)
c: Movinyl (registered trademark) 6969D (manufactured by Japan Coating Resin Co., Ltd.)
<Surfactant>
a: Polyether-modified silicone surfactant (TEGO (registered trademark) WET-KL245, manufactured by Evonik)
b: Acetylene glycol-based surfactant (Olfine E1010, manufactured by Nissin Chemical Industry Co., Ltd.)
c: Silicone-modified surfactant (KF-351A, manufactured by Shin-Etsu Silicone Co., Ltd.)
d: Polyether-modified silicone surfactant (TEGO (registered trademark) WET-250, manufactured by Evonik)
e: Polyether-modified silicone surfactant (BYK (registered trademark)-3450, manufactured by BYK-Chemie)
<Antifungal agent>
Proxel GXL (S) (manufactured by Lonza)
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　［評価］
　＜粘度＞
　上記組成物Ａ及びＢの粘度を、ＭＣＲ－１０２のローテーションモードで、温度：２５℃、時間設定：測定点１５０点、測定間隔：２ｓにて、せん断速度を１０００［１／ｓ］～１［１／ｓ］の範囲内として測定し、せん断速度１０００［１／ｓ］時の値をＶＡ及びＶＢとした。 [evaluation]
<Viscosity>
The viscosities of the compositions A and B were measured in the rotation mode of MCR-102 at a temperature of 25 ° C., a time setting of 150 measurement points, a measurement interval of 2 s, and a shear rate of 1000 [1 / s] to 1 [. 1/s], and the values at a shear rate of 1000 [1/s] were taken as VA and VB .
　＜チキソトロピック指数＞
　縦軸（Ｙ軸）に上記で測定した粘度ηａ［ｍＰａ・ｓ］、横軸（Ｘ軸）にせん断速度［１／ｓ］をそれぞれ対数でとったグラフを作成し、グラフの傾き（ｎ－１）からチキソトロピック指数ｎを求めた。 <Thixotropic Index>
Create a logarithmic graph with the viscosity ηa [mPa s] measured above on the vertical axis (Y-axis) and the shear rate [1/s] on the horizontal axis (X-axis). The thixotropic index n was obtained from 1).
　＜吐出安定性＞
　上記組成物Ａをコニカミノルタ製の独立駆動型インクジェットヘッド（３６０ｎｐｉ、吐出量６ｐＬ、１０２４ノズル）に充填し、ストロボ同期型の液滴観測装置で３０分間連続吐出試験を実施した。その後、以下の基準に従って吐出安定性を評価した。なお、△以上を実用上問題なしとした。
　◎：評価した２５６ノズル中、２５６ノズル全てのノズルが正常に吐出された。
　〇：評価した２５６ノズル中、異常吐出ノズルが１ノズル以上、４ノズル以下観測された。
　△：評価した２５６ノズル中、異常吐出ノズルが５ノズル以上、９ノズル以下観測された。
　×：評価した２５６ノズル中、異常吐出ノズルが１０ノズル以上観測された。 <Ejection stability>
A Konica Minolta independently driven inkjet head (360 npi, ejection volume 6 pL, 1024 nozzles) was filled with Composition A, and a continuous ejection test was conducted for 30 minutes using a stroboscope-synchronized droplet observation device. After that, ejection stability was evaluated according to the following criteria. In addition, △ or more was regarded as practically no problem.
A: Out of the 256 nozzles evaluated, all 256 nozzles ejected normally.
◯: Out of the 256 nozzles evaluated, 1 or more and 4 or less abnormal nozzles were observed.
Δ: Out of the 256 nozzles evaluated, 5 to 9 abnormal ejection nozzles were observed.
x: Out of the 256 nozzles evaluated, 10 or more abnormal discharge nozzles were observed.
　＜乾燥性＞
　上記組成物ＡをＰＥＴフィルム上に０．３ｍＬ滴下し、７０℃で５分乾燥させた。得られた乾燥物について、以下の基準に従って乾燥性を評価した。なお、〇以上を実用上問題なしとした。
　◎：塗膜が形成されており、塗膜を指で擦った場合に、指に色移りしなかった。
　〇：塗膜が形成されており、塗膜を指で擦った場合は色移りするが、指で押した場合には色移りしなかった。
　△：塗膜が形成されており、塗膜を指で押した場合にも色移りした。
　×：塗膜が形成されていなかった。 <Drying property>
0.3 mL of the composition A was dropped on a PET film and dried at 70° C. for 5 minutes. The dryness of the resulting dried product was evaluated according to the following criteria. In addition, 0 or more was regarded as no practical problem.
A: A coating film was formed, and when the coating film was rubbed with a finger, the color did not transfer to the finger.
◯: A coating film was formed, and color transfer occurred when the coating film was rubbed with a finger, but no color transfer occurred when the coating film was pressed with a finger.
Δ: A coating film was formed, and color transfer occurred even when the coating film was pressed with a finger.
x: A coating film was not formed.
　評価結果を、表IIIに示す。 The evaluation results are shown in Table III.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　上記結果より、本発明に係るインクは良好な吐出安定性が得られ、２５℃におけるせん断速度１０００［１／ｓ］時の粘度が、１５ｍＰａ・ｓ以下である、また、２５℃におけるチキソトロピック指数が、０．８５～１．０の範囲内であることにより、更に良好な吐出安定性が得られることがわかる。 From the above results, the ink according to the present invention has good ejection stability, has a viscosity of 15 mPa s or less at a shear rate of 1000 [1/s] at 25°C, and has a thixotropic index at 25°C. is in the range of 0.85 to 1.0, more favorable ejection stability can be obtained.
　そして、本発明に係るインクは、乾燥性が良好であり、さらに、組成物２２Ａと、その他との比較から、インク（組成物Ａ）における有機溶剤の含有量が、２５質量％以下であることにより、その効果が顕著であることがわかる。また、組成物３２Ａと、組成物１Ａ及び３１Ａとの比較から、インク（組成物Ａ）における有機溶剤の含有量が、５質量％以上であることにより、良好な吐出安定性が得られることがわかる。 The ink according to the present invention has good drying properties, and furthermore, the content of the organic solvent in the ink (composition A) is 25% by mass or less in comparison with composition 22A and others. It can be seen that the effect is remarkable. Further, from a comparison of Composition 32A with Compositions 1A and 31A, it was found that good ejection stability can be obtained when the content of the organic solvent in the ink (Composition A) is 5% by mass or more. Recognize.
　≪処理液の調製及び評価≫
　本発明に係る処理液１～１２を調製し、評価を行った。 <<Preparation and Evaluation of Treatment Solution>>
Treatment liquids 1 to 12 according to the present invention were prepared and evaluated.
　［処理液1の調製］
　下記成分を混合し、得られた混合液を１μｍのフィルターにより濾過して処理液１を調製した。 [Preparation of treatment liquid 1]
A treatment liquid 1 was prepared by mixing the following components and filtering the resulting mixed liquid through a 1 μm filter.
　酢酸カルシウム・水和物　　　　　　　　　　　　　　　　　３質量％
　ジプロピレングリコール　　　　　　　　　　　　　　　　１２質量％
　プロピレングリコール　　　　　　　　　　　　　　　　　１０質量％
　グリセリン　　　　　　　　　　　　　　　　　　　　　　１０質量％
　界面活性剤（ＴＥＧＯ（登録商標）ＷＥＴ－ＫＬ２４５、エボニック社製）
　　　　　　　　　　　　　　　　　　　　　　　　　　　　　１質量％
　防黴剤（プロキセルＧＸＬ（Ｓ）、ロンザ社製）　　　　０．１質量％
　イオン交換水　　　　　　　　（残量；全量が１００質量％となる量） Calcium acetate hydrate 3% by mass
Dipropylene glycol 12% by mass
Propylene glycol 10% by mass
Glycerin 10% by mass
Surfactant (TEGO (registered trademark) WET-KL245, manufactured by Evonik)
1% by mass
Antifungal agent (Proxel GXL (S), manufactured by Lonza) 0.1% by mass
Ion-exchanged water (remaining amount; the amount that makes the total amount 100% by mass)
　［処理液２～１２の調製］
　処理液１の調製において、凝集剤、有機溶剤、界面活性剤及び増粘剤の種類並びに添加量を下記表IVに記載のとおりに変更した以外は同様にして、処理液２～１２を調製した。なお、表IV内の有機溶剤、界面活性剤及び増粘剤については、インクの調製時に使用した成分と同義であり、インクの調製時に使用していないその他の有機溶剤及び凝集剤については、以下のとおりである。 [Preparation of treatment liquids 2 to 12]
Treatment solutions 2 to 12 were prepared in the same manner as in the preparation of treatment solution 1, except that the types and amounts of flocculants, organic solvents, surfactants, and thickeners were changed as shown in Table IV below. . The organic solvents, surfactants and thickeners in Table IV are synonymous with the components used in the preparation of the ink, and other organic solvents and flocculants not used in the preparation of the ink are described below It is as follows.
　＜有機溶剤＞
　ｆ：ジエチレングリコール
　＜凝集剤＞
　ａ：酢酸カルシウム・水和物
　ｂ：酢酸マグネシウム・四水和物
　ｃ：マロン酸
　ｄ：ユニセンスＫＨＥ１０３Ｌ（センカ社製）
　ｅ：リン酸
　ｆ：硝酸アルミニウム・九水和物 <Organic solvent>
f: diethylene glycol <flocculant>
a: Calcium acetate hydrate b: Magnesium acetate tetrahydrate c: Malonic acid d: Unisense KHE103L (manufactured by Senka)
e: phosphoric acid f: aluminum nitrate nonahydrate
　処理液１～１２について、吐出安定性の評価を行った。なお、評価方法は、インクの吐出安定性の評価方法と同義である。評価結果を、表IVに示す。 The ejection stability was evaluated for the treatment liquids 1 to 12. The evaluation method has the same meaning as the method for evaluating the ejection stability of the ink. Evaluation results are shown in Table IV.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　≪インクセットの評価≫
　上記インク（組成物Ａ）と処理液を、表Ｖ及びVIに記載のとおりに組み合わせてインクセットとし、評価を行った。 <<Evaluation of ink set>>
The above ink (composition A) and treatment liquid were combined as described in Tables V and VI to form an ink set and evaluated.
　［混合液の評価］
　＜混合液（組成物Ｃ及びＤ）の粘度ＶＣ及びＶＤ＞
　表Ｖに記載のインクセット１について、組成物１Ａ及び処理液１を３：１の質量比で混合し、１０分攪拌させて調製した溶液を組成物１Ｃ、同様に組成物１Ｂと処理液１を３：１の質量比で混合して１０分攪拌させて調製した溶液を組成物１Ｄとした。Ｅ型粘度計（ＴＶＥ－３３ＬＴ、東機産業社製）を用いて、２５℃、回転数２０ｒｐｍ（せん断速度２［１／ｓ］）の条件下で、組成物１Ｃ及び１Ｄの粘度を測定した値をそれぞれ、Ｖ１Ｃ及びＶ１Ｄとした。なお、せん断速度［１／ｓ］は、下記式により算出することができる。
　せん断速度［１／ｓ］＝せん断速度係数×回転数
　同様にして、インクセット２～４８についても、組成物Ｃ及び組成物Ｄの粘度（ＶＣ及びＶＤ）を測定した。 [Evaluation of mixed solution]
<Viscosities V C and V D of mixed liquids (compositions C and D)>
For Ink Set 1 described in Table V, Composition 1A and Treatment Liquid 1 were mixed in a mass ratio of 3:1 and stirred for 10 minutes to prepare Composition 1C, and similarly Composition 1B and Treatment Liquid 1. were mixed at a mass ratio of 3:1 and stirred for 10 minutes to prepare a solution as composition 1D. Using an E-type viscometer (TVE-33LT, manufactured by Toki Sangyo Co., Ltd.), the viscosities of compositions 1C and 1D were measured under the conditions of 25° C. and a rotation speed of 20 rpm (shear rate of 2 [1/s]). The values were taken as V 1C and V 1D respectively. In addition, the shear rate [1/s] can be calculated by the following formula.
Shear rate [1/s]=shear rate factor×number of revolutions Similarly, the viscosities (V C and V D ) of composition C and composition D were measured for ink sets 2 to 48 as well.
　＜粗大粒子数の割合ＲＣ及びＲＤ＞
　表Ｖに記載のインクセット１について、上記組成物１Ｃ及び１Ｄを、純水にて１００００倍に希釈後、パーティクルカウンター（ＲＩＯＮ社製、センサー：ＰＡＲＴＩＣＬＥ　ＳＥＮＳＯＲ　ＫＳ－４２Ｃ、コントローラー：ＣＯＮＴＲＯＬＬＥＲ　ＫＥ－４０Ｂ１、ポンプ：ＳＹＲＩＮＧＥ　ＳＡＭＰＬＥＲ　ＫＺ－３１Ｗ）にて、流量１０ｍＬ／ｍｉｎの条件で、粒径が０．５、１、２、３、５、７．５、１０、１２、１５及び２０μｍの粒子数を、それぞれカウントした。なお、粒子数の測定は３回実施し、その平均値を採用した。 <Proportion of number of coarse particles R C and R D >
For ink set 1 shown in Table V, the above compositions 1C and 1D were diluted 10,000 times with pure water, and then a particle counter (manufactured by RION, sensor: PARTICLE SENSOR KS-42C, controller: CONTROLLER KE-40B1, Pump: SYRINGE SAMPLER KZ-31W) at a flow rate of 10 mL / min, the number of particles with a particle size of 0.5, 1, 2, 3, 5, 7.5, 10, 12, 15 and 20 μm, counted each. The number of particles was measured three times, and the average value was adopted.
　組成物Ｃ及び組成物Ｄについて、全粒子数（上記粒径の粒子数の総和）に対する、粒径が５μｍ以上の粒子数の割合をそれぞれ、Ｒ１Ｃ及びＲ１Ｄとし、その比（Ｒ１Ｃ／Ｒ１Ｄ）を算出した。 For composition C and composition D, the ratio of the number of particles with a particle size of 5 μm or more to the total number of particles (total number of particles with the above particle size) is defined as R 1C and R 1D , respectively, and the ratio (R 1C / R 1D ) was calculated.
　［記録物の評価］
　（記録物の作製）
　インクセット１～４８を用いて、以下の方法で印字試験を実施した。コニカミノルタ製の独立駆動型インクジェットヘッド（３６０ｎｐｉ、吐出量６ｐＬ又は１４ｐＬ、１０２４ノズル）２個を搭載したスキャン型プリンターを準備し、先に記録するヘッドに各処理液を充填し、後に記録するヘッドに各インク（組成物Ａ）を充填した。その後、解像度７２０×７２０ｄｐｉの画像を走査方向Ｘ及び搬送方向Ｙに各々２分割した４つの画像（１８０×１８０ｄｐｉ）とし、一つの印刷領域を４回印刷する４パスモードで、必ず処理液が先に記録される向きに片方向で印刷を実施した。キャリッジの搬送速度は３００ｍｍ／ｓｅｃに設定し、処理液とインクの記録間に乾燥工程を設けない構成とした。記録媒体は、ＰＥＴフィルム（ＦＥ２００１、厚さ５０μｍ、フタムラ化学社製）を用いた。印刷後に記録媒体を９０℃に設定した乾燥機に投入し、５分間加熱乾燥して記録物を得た。
　なお、処理液の付与量は、インクの付与量の全質量に対して、３３．３質量％（インク：処理液＝３：１）であった。
　記録物について、下記の画質評価を行った。 [Evaluation of recorded matter]
(Preparation of Recorded Matter)
Using ink sets 1 to 48, printing tests were carried out by the following method. Prepare a scan-type printer equipped with two Konica Minolta independently driven inkjet heads (360 npi, ejection volume 6 pL or 14 pL, 1024 nozzles), fill the head that records first with each treatment liquid, and print the head later. was filled with each ink (composition A). After that, an image with a resolution of 720 x 720 dpi is divided into four images (180 x 180 dpi) each in the scanning direction X and the transport direction Y, and in a 4-pass mode in which one printing area is printed four times, the treatment liquid always comes first. Printing was carried out unidirectionally in the direction recorded in the The conveying speed of the carriage was set to 300 mm/sec, and no drying process was provided between the recording of the treatment liquid and the ink. A PET film (FE2001, thickness 50 μm, manufactured by Futamura Chemical Co., Ltd.) was used as a recording medium. After printing, the recording medium was placed in a dryer set at 90° C. and dried by heating for 5 minutes to obtain a recorded matter.
The amount of treatment liquid applied was 33.3% by mass (ink:treatment liquid=3:1) with respect to the total mass of the amount of ink applied.
The recorded matter was subjected to the following image quality evaluation.
　＜印字品質＞
　上記の方法で、５ポイント及び７ポイントのＭＳ明朝体で、漢字「口、四、日、回、因、困、固、国、目、図、國」の抜き文字を印字し、印字した文字画像を目視観察し、下記の評価基準に従って印字品質の評価を行った。なお、△以上を実用上問題なしとした。
　◎：５ポイントの抜き文字全てが、細部まで明瞭に記録されていた。
　〇：５ポイントの抜き文字は一部しか判読できないが、７ポイントの抜き文字全てが判読可能であった。
　△：７ポイントの抜き文字のうち、一部判読できないものがあったが、おおよそ判読可能であった。
　×：７ポイントの抜き文字もほとんど判読できなかった。 <Print quality>
By the above method, in 5-point and 7-point MS Mincho typeface, the kanji characters "mouth, four, days, times, causes, problems, solids, countries, eyes, figures, countries" were printed and printed. The character images were visually observed, and the print quality was evaluated according to the following evaluation criteria. In addition, △ or more was regarded as practically no problem.
⊚: All 5-point cut-out characters were clearly recorded in detail.
Good: Only part of the 5-point cut-out characters was legible, but all of the 7-point cut-out characters were legible.
Δ: Most of the 7-point cutout characters were illegible, although some were illegible.
x: 7-point cut-out characters were almost unreadable.
　＜平滑性＞
　上記の方法で、５ｃｍ×５ｃｍのベタ画像を記録し、表面光沢及び凹凸の有無を評価した。なお、〇以上を実用上問題なしとした。
　◎：明るい場所で観測した場合に光の反射が見られ、指でなぞった際に表面凹凸がなかった。
　〇：明るい場所で観測した場合に光の反射が見られなかったが、指でなぞった際に表面凹凸がなかった。
　×：明るい場所で観測した場合に光の反射が見られず、指でなぞった際に表面凹凸を感じた。 <Smoothness>
A solid image of 5 cm×5 cm was recorded by the above method, and the presence or absence of surface gloss and unevenness was evaluated. In addition, 0 or more was regarded as no practical problem.
⊚: Reflection of light was observed when observed in a bright place, and no surface unevenness was observed when traced with a finger.
◯: No light reflection was observed when observed in a bright place, but no surface unevenness was observed when traced with a finger.
x: No reflection of light was observed when observed in a bright place, and surface unevenness was felt when traced with a finger.
　評価結果を、下記表Ｖ及びVIに示す。 The evaluation results are shown in Tables V and VI below.
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
　上記結果より、インクセット４７については、組成物Ａの良好な吐出安定性が得られず、記録物の良好な画質（印字品質及び平滑性）も得られないことがわかる。また、インクセット４８については、記録物の良好な平滑性が得られず、組成物Ａに含有される増粘剤ｇは、色材の過凝集を阻害する機能を有さないことがわかる。
　一方、本発明のインクセットは、インクの吐出安定性が良好であり、さらに、記録物の画質が向上していることがわかる。 From the above results, it can be seen that ink set 47 does not provide good ejection stability for composition A, and does not provide good image quality (printing quality and smoothness) of recorded matter. Ink set 48 does not provide good smoothness of the recorded matter, and it can be seen that the thickener g contained in composition A does not have the function of inhibiting overaggregation of the coloring material.
On the other hand, it can be seen that the ink set of the present invention has good ink ejection stability, and furthermore, the image quality of the printed matter is improved.
　さらに、本発明の実施例において、インクセット６及び７と、その他との比較から、ＶＣ≦ＶＤであることにより、印字品質が向上することがわかる。
　インクセット４～７及び１１～１２と、その他との比較から、ＲＣ／ＲＤ＜１であることにより、印字品質が向上することがわかる。
　インクセット２１と、インクセット１及び１３～２０との比較から、また、インクセット４１と、インクセット２３、３９、４０及び４４との比較から、増粘剤の含有量が、色材の全質量に対して５～１００質量％の範囲内であることにより、印字品質が向上することがわかる。
　インクセット２７と、インクセット１及び２３～２５との比較から、増粘剤が、少なくとも同一粒子中に親水部と疎水部とをもつことにより、印字品質が向上することがわかる。 Further, in the examples of the present invention, a comparison between ink sets 6 and 7 and others shows that the print quality is improved when V C ≤ V D .
A comparison of ink sets 4 to 7 and 11 to 12 with others shows that printing quality is improved when R C /R D <1.
From the comparison of ink set 21 with ink sets 1 and 13 to 20, and from the comparison of ink set 41 with ink sets 23, 39, 40 and 44, the content of the thickening agent It can be seen that printing quality is improved when the content is in the range of 5 to 100% by mass.
A comparison between ink set 27 and ink sets 1 and 23 to 25 shows that printing quality is improved when the thickener has at least a hydrophilic portion and a hydrophobic portion in the same particle.
　インクセット１１と、インクセット１～５及び１２との比較から、凝集剤が、多価金属塩、カチオン性ポリマー又は有機酸であることにより、印字品質及び平滑性が向上することがわかり、インクセット１２と、インクセット１～３との比較から、多価金属塩が、少なくともカルシウム塩又はマグネシウム塩を含有することにより、印字品質及び平滑性が向上することがわかる。
　インクセット２２及び４３と、その他との比較から、ＶＣが、１５ｍＰａ・ｓ以上であることにより、印字品質が向上することがわかる。 A comparison of ink set 11 with ink sets 1 to 5 and 12 shows that the use of a polyvalent metal salt, cationic polymer, or organic acid as the aggregating agent improves print quality and smoothness. A comparison between Set 12 and Ink Sets 1 to 3 shows that the polyvalent metal salt containing at least calcium salt or magnesium salt improves print quality and smoothness.
A comparison of the ink sets 22 and 43 with the others shows that the printing quality is improved when the V C is 15 mPa·s or more.
　本発明のインクジェット記録用インクセットを用いることにより、吸収性の低い・無い記録媒体に、良好な画質で記録することができるため、ＰＥＴフィルムや缶詰食品用包装材料においても良好な画質のインクジェット記録を適用することができる。 By using the ink set for ink jet recording of the present invention, it is possible to record with good image quality on a recording medium with low or no absorbency. can be applied.
　５　マニホールド
　６　筐体
　８　インク循環装置
５３　第１インクポート
５６　第４インクポート
８１　供給用サブタンク
８２　循環用サブタンク
８３　メインタンク
８６　インク流路
８８　ポンプ
１００　インクジェットヘッド
２００　インクジェット記録装置
２１０　給紙部
２２０　画像記録部
２２４　キャリッジ
２３０　排紙部
２４０　制御部
　Ｍ　記録媒体
　Ｐ　記録媒体 5 Manifold 6 Housing 8 Ink circulation device 53 First ink port 56 Fourth ink port 81 Supply sub-tank 82 Circulation sub-tank 83 Main tank 86 Ink flow path 88 Pump 100 Inkjet head 200 Inkjet recording device 210 Paper feed unit 220 Image recording Unit 224 Carriage 230 Paper discharge unit 240 Control unit M Recording medium P Recording medium

Claims (17)

  1. 　インク及び処理液を含むインクジェット記録用インクセットであって、
    　前記インクが、増粘剤、色材、水及び有機溶剤を含有し、
    　前記処理液が、凝集剤、水及び有機溶剤を含有し、
    　前記増粘剤が、前記色材の過凝集を阻害する機能を有する
    　ことを特徴とするインクジェット記録用インクセット。     An inkjet recording ink set comprising an ink and a treatment liquid,
    The ink contains a thickener, a coloring material, water and an organic solvent,
    The treatment liquid contains a flocculant, water and an organic solvent,
    The ink set for inkjet recording, wherein the thickener has a function of inhibiting excessive aggregation of the coloring material.
  2. 　前記インクを組成物Ａとし、
    　前記インクのうち、前記増粘剤を除いたものを組成物Ｂとし、
    　前記組成物Ａと前記処理液とを混合させたものを組成物Ｃとし、かつ、
    　前記組成物Ｂと前記処理液とを混合させたものを組成物Ｄとしたとき、
    　前記組成物Ａ及びＢの２５℃におけるせん断速度１０００［１／ｓ］時の粘度ＶＡ及びＶＢ、並びに、前記組成物Ｃ及びＤの２５℃におけるせん断速度２［１／ｓ］時の粘度ＶＣ及びＶＤが、下記関係式（１）及び（２）を満たす
    　式（１）：　ＶＡ＞ＶＢ
    　式（２）：　ＶＣ≦ＶＤ
    　ことを特徴とする請求項１に記載のインクジェット記録用インクセット。     The ink is composition A,
    A composition B is obtained by removing the thickening agent from the ink,
    A composition C is obtained by mixing the composition A and the treatment liquid, and
    When the composition D is obtained by mixing the composition B and the treatment liquid,
    The viscosities V A and V B of the compositions A and B at a shear rate of 1000 [1/s] at 25° C., and the viscosities of the compositions C and D at a shear rate of 2 [1/s] at 25° C. V C and V D satisfy the following relational expressions (1) and (2): Formula (1): V A >V B
    Formula (2): V C ≤ V D
    The ink set for inkjet recording according to claim 1, characterized by:
  3. 　前記組成物Ａの２５℃におけるせん断速度１０００［１／ｓ］時の粘度ＶＡが、１５ｍＰａ・ｓ以下である
    　ことを特徴とする請求項２に記載のインクジェット記録用インクセット。     3. The ink set for inkjet recording according to claim 2, wherein the composition A has a viscosity VA of 15 mPa·s or less at a shear rate of 1000 [1/s] at 25°C.
  4. 　前記組成物Ｃ及びＤにおける５μｍ以上の粗大粒子数の割合ＲＣ及びＲＤにおいて、
    　下記関係式（３）を満たす
    　式（３）：　ＲＣ／ＲＤ＜１
    　ことを特徴とする請求項２又は請求項３のいずれか一項に記載のインクジェット記録用インクセット。     In the ratios R C and R D of the number of coarse particles of 5 μm or more in the compositions C and D,
    Formula (3) that satisfies the following relational expression (3): R C /R D <1
    4. The ink set for inkjet recording according to claim 2 or 3, characterized in that:
  5. 　前記増粘剤の含有量が、前記色材の全質量に対して５～１００質量％の範囲内である
    　ことを特徴とする請求項１から請求項４までのいずれか一項に記載のインクジェット記録用インクセット。     5. The inkjet according to any one of claims 1 to 4, wherein the content of the thickening agent is in the range of 5 to 100% by mass with respect to the total mass of the coloring material. Ink set for recording.
  6. 　前記インクの２５℃におけるチキソトロピック指数が、０．８５～１．０の範囲内である
    　ことを特徴とする請求項１から請求項５までのいずれか一項に記載のインクジェット記録用インクセット。     The ink set for inkjet recording according to any one of claims 1 to 5, wherein the ink has a thixotropic index at 25°C in the range of 0.85 to 1.0.
  7. 　前記増粘剤が、少なくとも同一粒子中に親水部と疎水部とをもつ
    　ことを特徴とする請求項１から請求項６までのいずれか一項に記載のインクジェット記録用インクセット。     The ink set for inkjet recording according to any one of claims 1 to 6, wherein the thickener has at least a hydrophilic portion and a hydrophobic portion in the same particle.
  8. 　前記インクにおける前記有機溶剤の含有量が、前記インクの全質量に対して５～２５質量％の範囲内である
    　ことを特徴とする請求項１から請求項７までのいずれか一項に記載のインクジェット記録用インクセット。     The content of the organic solvent in the ink is in the range of 5 to 25% by mass with respect to the total mass of the ink. Ink set for inkjet recording.
  9. 　前記凝集剤が、多価金属塩、カチオン性ポリマー又は有機酸である
    　ことを特徴とする請求項１から請求項８までのいずれか一項に記載のインクジェット記録用インクセット。     The ink set for inkjet recording according to any one of claims 1 to 8, wherein the aggregating agent is a polyvalent metal salt, a cationic polymer, or an organic acid.
  10. 　前記多価金属塩が、少なくともカルシウム塩又はマグネシウム塩を含有する
    　ことを特徴とする請求項９に記載のインクジェット記録用インクセット。     10. The ink set for inkjet recording according to claim 9, wherein the polyvalent metal salt contains at least a calcium salt or a magnesium salt.
  11. 　前記インク及び前記処理液を混合させた組成物の２５℃におけるせん断速度２［１／ｓ］時の粘度ＶＣが、１５ｍＰａ・ｓ以上である
    　ことを特徴とする請求項１から請求項１０までのいずれか一項に記載のインクジェット記録用インクセット。     A composition obtained by mixing the ink and the treatment liquid has a viscosity VC of 15 mPa·s or more at a shear rate of 2 [1/s] at 25° C. The ink set for inkjet recording according to any one of .
  12. 　インクジェット記録用インクセットを用いるインクジェット記録方法であって、
    　請求項１から請求項１１までのいずれか一項に記載のインクジェット記録用インクセットを用い、
    　前記インク及び前記処理液が、記録媒体表面において、液体同士で合一する
    　ことを特徴とするインクジェット記録方法。     An inkjet recording method using an inkjet recording ink set,
    Using the inkjet recording ink set according to any one of claims 1 to 11,
    An inkjet recording method, wherein the ink and the treatment liquid are combined with each other on the surface of a recording medium.
  13. 　前記記録媒体の前記インクの吸収性及び前記インクの付与量に応じて、前記処理液の印字率又は液滴量を変化させる
    　ことを特徴とする請求項１２に記載のインクジェット記録方法。     13. The inkjet recording method according to claim 12, wherein the printing rate or the amount of droplets of the treatment liquid is changed according to the absorbability of the ink of the recording medium and the amount of the ink applied.
  14. 　前記インクジェット記録用インクセットが、千鳥配置されたインクジェットヘッドから吐出される
    　ことを特徴とする請求項１２又は請求項１３に記載のインクジェット記録方法。     14. The inkjet recording method according to claim 12, wherein the ink set for inkjet recording is ejected from inkjet heads arranged in a staggered manner.
  15. 　前記インクジェット記録用インクセットが、循環機構を有するインクジェット記録装置から吐出される
    　ことを特徴とする請求項１２から請求項１４までのいずれか一項に記載のインクジェット記録方法。     15. The inkjet recording method according to any one of claims 12 to 14, wherein the ink set for inkjet recording is discharged from an inkjet recording apparatus having a circulation mechanism.
  16. 　前記循環機構が、両方向循環である
    　ことを特徴とする請求項１５に記載のインクジェット記録方法。     16. The inkjet recording method according to claim 15, wherein the circulation mechanism is bidirectional circulation.
  17. 　インクジェット記録用インクセットを用いるインクジェット記録装置であって、
    　請求項１から請求項１１までのいずれか一項に記載のインクジェット記録用インクセットを用い、
    　前記インクジェット記録装置が、前記インク用インクジェットヘッド及び前記処理液用インクジェットヘッドを有し、
    　前記インク用インクジェットヘッド及び前記処理液用インクジェットヘッドが、同一キャリッジに搭載されている、又は、
    　前記インク用インクジェットヘッド及び前記処理液用インクジェットヘッドが、それぞれ別のキャリッジに搭載され、乾燥機構を挟むことなく前記キャリッジが隣接している
    　ことを特徴とするインクジェット記録装置。     An inkjet recording apparatus using an inkjet recording ink set,
    Using the inkjet recording ink set according to any one of claims 1 to 11,
    The inkjet recording device has the inkjet head for the ink and the inkjet head for the treatment liquid,
    The inkjet head for ink and the inkjet head for treatment liquid are mounted on the same carriage, or
    An inkjet recording apparatus, wherein the inkjet head for ink and the inkjet head for treatment liquid are mounted on separate carriages, and the carriages are adjacent to each other without a drying mechanism interposed therebetween.
PCT/JP2021/045458 2021-12-10 2021-12-10 Ink set for ink-jet recording, ink-jet recording method, and ink-jet recording device WO2023105737A1 (en)

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Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005306025A (en) * 2004-03-25 2005-11-04 Fuji Photo Film Co Ltd Inkjet recording apparatus and liquid application method
JP2010155908A (en) * 2008-12-26 2010-07-15 Fujifilm Corp Inkjet recording liquid
WO2013179838A1 (en) * 2012-05-29 2013-12-05 Dic株式会社 Aqueous ink set for ink jet recording
JP2015044408A (en) * 2009-03-25 2015-03-12 コニカミノルタ株式会社 Method of forming images
WO2017013983A1 (en) * 2015-07-22 2017-01-26 コニカミノルタ株式会社 Image recording body and ink jet image recording method
WO2017013984A1 (en) * 2015-07-22 2017-01-26 コニカミノルタ株式会社 Precoating agent for inkjet and image forming method using same
JP2017024365A (en) * 2015-07-27 2017-02-02 富士フイルム株式会社 Image recording method
JP2019162741A (en) * 2018-03-19 2019-09-26 コニカミノルタ株式会社 Image-formed article, ink set, and image forming method
JP2019218418A (en) * 2018-06-15 2019-12-26 コニカミノルタ株式会社 Inkjet recording liquid set and inkjet recording method
JP2020100005A (en) * 2018-12-20 2020-07-02 セイコーエプソン株式会社 Recording method, ink set and printer
WO2021065682A1 (en) * 2019-09-30 2021-04-08 富士フイルム株式会社 Ink set for printing, and printing method
WO2021084960A1 (en) * 2019-10-29 2021-05-06 富士フイルム株式会社 Image recording product and production method therefor
WO2021140772A1 (en) * 2020-01-10 2021-07-15 富士フイルム株式会社 Image recording method
JP2021155556A (en) * 2020-03-27 2021-10-07 セイコーエプソン株式会社 Composition set, and recording method

Patent Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005306025A (en) * 2004-03-25 2005-11-04 Fuji Photo Film Co Ltd Inkjet recording apparatus and liquid application method
JP2010155908A (en) * 2008-12-26 2010-07-15 Fujifilm Corp Inkjet recording liquid
JP2015044408A (en) * 2009-03-25 2015-03-12 コニカミノルタ株式会社 Method of forming images
WO2013179838A1 (en) * 2012-05-29 2013-12-05 Dic株式会社 Aqueous ink set for ink jet recording
WO2017013983A1 (en) * 2015-07-22 2017-01-26 コニカミノルタ株式会社 Image recording body and ink jet image recording method
WO2017013984A1 (en) * 2015-07-22 2017-01-26 コニカミノルタ株式会社 Precoating agent for inkjet and image forming method using same
JP2017024365A (en) * 2015-07-27 2017-02-02 富士フイルム株式会社 Image recording method
JP2019162741A (en) * 2018-03-19 2019-09-26 コニカミノルタ株式会社 Image-formed article, ink set, and image forming method
JP2019218418A (en) * 2018-06-15 2019-12-26 コニカミノルタ株式会社 Inkjet recording liquid set and inkjet recording method
JP2020100005A (en) * 2018-12-20 2020-07-02 セイコーエプソン株式会社 Recording method, ink set and printer
WO2021065682A1 (en) * 2019-09-30 2021-04-08 富士フイルム株式会社 Ink set for printing, and printing method
WO2021084960A1 (en) * 2019-10-29 2021-05-06 富士フイルム株式会社 Image recording product and production method therefor
WO2021140772A1 (en) * 2020-01-10 2021-07-15 富士フイルム株式会社 Image recording method
JP2021155556A (en) * 2020-03-27 2021-10-07 セイコーエプソン株式会社 Composition set, and recording method

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