JP2019023266A - Composite particle aqueous dispersion - Google Patents

Abstract

To provide a composite particle aqueous dispersion which contains pigment particles that have excellent adhesion to a base material when used in ink and the like and are stably dispersed with time.SOLUTION: A composite particle aqueous dispersion (X) contains: a composite particle (c) in which polyurethane resin particles (b) are flocculated on pigment particles (a1) or particles (a2) with a dispersant (d) adsorbed on the pigment particles (a1); and an aqueous medium. The ratio between a volume average particle size of the pigment particles (a1) to a volume average particle size of the polyurethane resin particles (b) [the volume average particle size of (a1)/the volume average particle size of (b)] is 1.5-7.SELECTED DRAWING: None

Description

  The present invention relates to an aqueous composite particle dispersion containing pigment particles.

  Conventionally, as a method for dispersing a pigment in water, a method using a surfactant, a method for modifying a hydrophilic group on the pigment surface, a method for coating the pigment with a hydrophilic resin, and the like are used. Among these, a method of coating with a hydrophilic resin has been particularly studied since the dispersion stability is high and the viscosity of the aqueous pigment dispersion is relatively low. For example, a pigment dispersion (for example, Patent Document 1) coated with an organic polymer compound containing an anionic group or a pigment dispersion (for example, Patent Document 2) in which a pigment surface-treated with rosin or the like is coated with a resin. It is disclosed. However, when used as an ink or the like, there is a problem that the adhesion to the substrate is insufficient, or the dispersion state changes with time and the viscosity increases or decreases.

Japanese Patent Laid-Open No. 10-140065 JP 10-36732 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide pigment particles that have excellent adhesion to a substrate when used in inks and are stably dispersed over time. It is to provide an aqueous dispersion containing composite particles.

  The inventors of the present invention have arrived at the present invention as a result of intensive studies to achieve the above object. That is, the present invention provides composite particles (c) in which polyurethane resin particles (b) are aggregated on the surface of pigment particles (a1) or particles (a2) formed by adsorbing dispersant (d) on pigment particles (a1). And an aqueous dispersion of composite particles, the ratio of the volume average particle diameter of the pigment particles (a1) to the volume average particle diameter of the polyurethane resin particles (b) [volume average particle diameter of (a1) Composite particle aqueous dispersion (X) having a volume average particle diameter of (b)] of 1.5 to 7; aqueous ink (Y) containing the composite particle aqueous dispersion (X); pigment particles (a1) Alternatively, composite particles (c) in which polyurethane resin particles (b) are aggregated on the surface of particles (a2) formed by adsorbing dispersant (d) on pigment particles (a1) and aqueous dispersions containing composite particles (c) A method for producing a body, wherein the polyurethane resin particles A step of adding the aqueous dispersion (A) containing the pigment particles (a1) or the particles (a2) to the aqueous dispersion (B) containing (b) while stirring the aqueous dispersion (B). The ratio of the volume average particle diameter of the pigment particles (a1) to the volume average particle diameter of the polyurethane resin particles (b) [volume average particle diameter of (a1) / volume average particle diameter of (b)] is 1. 0.5-7, the absolute value of the difference between the zeta potential of the pigment particles (a1) and the zeta potential of the polyurethane resin particles (b), and the zeta potential of the particles (a2) and the polyurethane resin particles (b). This is a method for producing an aqueous composite particle dispersion (X) in which the absolute value of the difference from the zeta potential is 30 to 100 mV.

  According to the present invention, an aqueous composite particle dispersion containing pigment particles, which is excellent in adhesion to a substrate when used in an ink or the like and stably disperses with time, is obtained.

  In the composite particle aqueous dispersion (X) of the present invention, the polyurethane resin particles (b) are aggregated on the surface of the pigment particles (a1) or the particles (a2) formed by adsorbing the dispersant (d) on the pigment particles (a1). The composite particles (c) thus formed and an aqueous medium are contained.

<Particle (a2) formed by adsorbing dispersant (d) on pigment particles (a1) and (a1)>
Examples of the pigment particles (a1) include pigment particles such as inorganic pigments and organic pigments.
Examples of inorganic pigments include carbon black, titanium oxide, zinc white, zinc oxide, trypone, iron oxide, aluminum oxide, silicon dioxide, kaolinite, montmorillonite, talc, barium sulfate, calcium carbonate, silica, alumina, cadmium red, red pepper, Molybdenum red, chrome vermilion, molybdate orange, yellow lead, chrome yellow, cadmium yellow, yellow iron oxide, titanium yellow, chromium oxide, pyridiane, cobalt green, titanium cobalt green, cobalt chrome green, ultramarine blue, ultramarine blue, bitumen , Cobalt blue, cerulean blue, manganese violet, cobalt violet and mica.

  Examples of organic pigments include azo, azomethine, polyazo, phthalocyanine, quinacridone, anthraquinone, indigo, thioindigo, quinophthalone, benzimidazolone, isoindoline, and isoindolinone pigments. It is done.

  Examples of pigments classified according to ink use include black pigments, yellow ink pigments, magenta ink pigments, and cyan ink pigments, and specific examples thereof are as follows.

  Black pigments include furnace black, lamp black, acetylene black, channel black and other carbon blacks (CI Pigment Black 7), copper, iron (CI Pigment Black 11) and other metals, oxidation Examples thereof include metal compounds such as titanium and organic pigments such as aniline black (CI Pigment Black 1).

  Examples of commercially available carbon black include No. 2300, no. 900, MCF-88, no. 33, no. 40, no. 45, no. 52, MA7, MA8, MA100, no. 2200B (all manufactured by Mitsubishi Chemical Corporation); Raven700, 5750, 5250, 5000, 3500, 1255 (all manufactured by Columbia); Regal400R, 330R, 660R, Mogu L, Monarch700, 800, 880, 900, 1000, 1100, 1300, Monarch 1400 (all manufactured by Cabot Corporation); Color Black FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, Printex 35, U, V, 140U, 140V, Special Black 6, 5, 4A, 4 (all manufactured by Degussa).

  As a pigment for yellow ink, C.I. I. Pigment yellow 1, C.I. I. Pigment yellow 2, C.I. I. Pigment yellow 3, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 16, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 73, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 75, C.I. I. Pigment yellow 83, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 95, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 98, C.I. I. Pigment yellow 114, C.I. I. Pigment yellow 120, C.I. I. Pigment yellow 128, C.I. I. Pigment yellow 129, C.I. I. Pigment yellow 138, C.I. I. Pigment yellow 150, C.I. I. Pigment yellow 151, C.I. I. Pigment yellow 154, C.I. I. Pigment yellow 155, C.I. I. Pigment yellow 174, C.I. I. Pigment yellow 180 and C.I. I. And CI Pigment Yellow 185.

  Examples of pigments for magenta ink include C.I. I. Pigment red 5, C.I. I. Pigment red 7, C.I. I. Pigment red 12, C.I. I. Pigment red 48 (Ca), C.I. I. Pigment red 48 (Mn), C.I. I. Pigment red 57 (Ca), C.I. I. Pigment red 57: 1, C.I. I. Pigment red 112, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 146, C.I. I. Pigment red 168, C.I. I. Pigment red 176, C.I. I. Pigment red 184, C.I. I. Pigment red 185, C.I. I. Pigment red 202, pigment violet 19, and the like.

  Examples of the pigment for cyan ink include C.I. I. Pigment blue 1, C.I. I. Pigment blue 2, C.I. I. Pigment blue 3, C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 4, C.I. I. Pigment blue 15:34, C.I. I. Pigment blue 16, C.I. I. Pigment blue 22, C.I. I. Pigment blue 60, C.I. I. Pigment blue 63, C.I. I. Pigment blue 66; C.I. I. Bat Blue 4 and C.I. I. Examples include Bat Blue 60.

  When the polyurethane resin particles (b) are aggregated on the surface of the pigment particles (a1) to obtain the composite particles (c), the aqueous dispersion (A) containing the pigment particles (a1) and the polyurethane resin particles ( A method of mixing the aqueous dispersion (B) containing b) is preferably used. As a method of dispersing the pigment particles (a1) in the aqueous medium, a method using self-dispersing pigment particles as the pigment particles (a1) and a method of dispersing the pigment particles (a1) in the aqueous medium using the dispersant (d) Etc. From the viewpoint of the stability of the aqueous dispersion of the composite particles (c), it is preferable to use self-dispersing pigment particles as the pigment particles (a1).

  When self-dispersing pigment particles are used, the polyurethane resin particles (b) aggregate on the surface of the pigment particles (a1), and when the dispersant (d) is used, the dispersant (d) is added to the pigment particles (a1). The polyurethane resin particles (b) aggregate on the surface of the adsorbed particles (a2).

  The self-dispersing pigment particles mean inorganic pigment particles or organic pigment particles that can be dispersed in an aqueous medium without introducing a dispersant or a resin by introducing a hydrophilic functional group on the surface of the pigment particles. Examples of the hydrophilic group to be bonded to the surface include a carbonyl group, a carboxyl group, a hydroxyl group, a sulfo group, and a phosphate group.

  Commercially available self-dispersing pigment particles include Aqua-Black 001 and 162 manufactured by Tokai Carbon Co., Ltd. having a carboxyl group as a hydrophilic functional group, Cab-O-Jet 300 manufactured by Cabot Corporation, and Cabot Corporation having a sulfo group. Examples thereof include Cab-O-Jet 200, 250, 260, and 270.

The self-dispersing pigment particles can be obtained, for example, by subjecting the pigment particles and the oxidizing agent to an oxidation treatment by heating them with a heatable facility. Specifically, the pigment particles and the oxidant are charged in a container and uniformly stirred, and then heated with no stirring in a heating dryer or heating furnace, a simple pressure reactor (autoclave), flask, uniaxial or Examples thereof include a method of reacting by heating with stirring or kneading in a biaxial kneader, plast mill or universal kneader. Among them, the method of heating and reacting while stirring or kneading is preferable because the homogeneity of (a1) obtained is high and (a1) excellent in dispersion stability can be obtained.
The temperature of the oxidation treatment when producing the self-dispersing pigment particles is preferably 40 to 90 ° C. The oxidation treatment time is preferably 1 hour to 10 hours.

  Examples of the dispersant (d) used when dispersing the pigment particles (a1) in the aqueous medium include a nonionic surfactant (d1), an anionic surfactant (d2), a cationic surfactant (d3), Examples include amphoteric surfactants (d4) and polymeric dispersants (d5). A dispersing agent (d) may be used individually by 1 type, or may use 2 or more types together.

  Examples of (d1) include alkylene oxide (hereinafter abbreviated as AO) addition-type nonionic surfactants and polyhydric alcohol-type nonionic surfactants. Examples of the AO addition type include ethylene oxide (hereinafter abbreviated as EO) adduct of aliphatic alcohol having 10 to 20 carbon atoms, EO adduct of phenol, EO adduct of nonylphenol, and EO of alkylamine having 8 to 22 carbon atoms. Examples include adducts and EO adducts of polypropylene glycol. As the polyhydric alcohol type, polyhydric (3 to 8 or more) alcohol (2 to 30 carbon atoms) fatty acid (8 to 24 carbon atoms) ester (Glycerin monostearate, glycerin monooleate, sorbitan monolaurate, sorbitan monooleate, etc.) and alkyl (having 4 to 24 carbon atoms) poly (degree of polymerization 1 to 10) glycosides.

  (D2) includes an ether carboxylic acid having a hydrocarbon group having 8 to 24 carbon atoms or a salt thereof [sodium lauryl ether acetate and (poly) oxyethylene (addition mole number 1 to 100) sodium lauryl ether acetate, etc.]; carbon Sulfate ester or ether sulfate having a hydrocarbon group of 8 to 24 and salts thereof [sodium lauryl sulfate, (poly) oxyethylene (addition mole number 1 to 100) sodium lauryl sulfate, (poly) oxyethylene (addition mole) 1-100) lauryl sulfate triethanolamine and (poly) oxyethylene (addition mole number 1-100) coconut oil fatty acid monoethanolamide sodium sulfate and the like]; sulfonate having a hydrocarbon group having 8 to 24 carbon atoms [ Sodium dodecylbenzenesulfonate, etc.]; charcoal having 8 to 24 carbon atoms Sulfosuccinates having one or two hydrogen groups; phosphate esters or ether phosphates having 8 to 24 carbon atoms and their salts [sodium lauryl phosphate and (poly) oxyethylene (addition moles) A fatty acid salt having a hydrocarbon group having 8 to 24 carbon atoms [sodium laurate, triethanolamine laurate and the like]; and a hydrocarbon group having 8 to 24 carbon atoms. Acylated amino acid salts [coconut oil fatty acid methyl taurine sodium, coconut oil fatty acid sarcosine sodium, coconut oil fatty acid sarcosine triethanolamine, N-coconut oil fatty acid acyl-L-glutamic acid triethanolamine, N-coconut oil fatty acid acyl-L- Sodium glutamate and lauroylmethyl-β-a Lanine sodium, etc.].

  (D3) includes quaternary ammonium salt types [stearyltrimethylammonium chloride, behenyltrimethylammonium chloride, distearyldimethylammonium chloride, ethyl lanolin sulfate fatty acid aminopropylethyldimethylammonium, etc.] and amine salt type [diethylaminoethylamide stearate] Lactate, dilaurylamine hydrochloride and oleylamine lactate, etc.].

  (D4) is a betaine-type amphoteric surfactant [coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, laurylhydroxysulfo Betaine and lauroylamidoethylhydroxyethylcarboxymethylbetaine hydroxypropyl phosphate sodium etc.] and amino acid type amphoteric surfactants [sodium β-laurylaminopropionate etc.] and the like.

  (D5) includes natural gums such as gum arabic, tragan gum, guar gum, karaya gum, locust bean gum, arabinogalactone, pectin, quince seed starch, alginic acid, carrageenan, agar, gelatin, casein, albumin, collagen, xanthene gum, dextran, etc. Polymer dispersant. Semi-synthetic polymer dispersants such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, sodium starch glycolate, sodium starch phosphate ester, sodium alginate, propylene glycol alginate. Vinyl polymers such as polyvinyl alcohol, polyvinyl pyrrolidone and polyvinyl methyl ether, non-crosslinked polyacrylamide, polyacrylic acid or alkali metal salts thereof, acrylic resins such as water-soluble styrene acrylic resin, water-soluble styrene maleic resin, water-soluble Vinyl naphthalene acrylic resin, water-soluble vinyl naphthalene maleic acid resin, polyvinyl pyrrolidone, polyvinyl alcohol, alkali metal salt of β-naphthalene sulfonic acid formalin condensate, salt of cationic functional group such as quaternary ammonium and amino group in the side chain Examples thereof include synthetic polymer dispersants such as polymer compounds.

  The aqueous medium in the present invention means water and a mixture of water and the organic solvent (s). Examples of the organic solvent (s) include ketone solvents (for example, acetone and methyl ethyl ketone), ester solvents (for example, ethyl acetate and dibasic acid ester (DBE)), ether solvents (for example, tetrahydrofuran), amide solvents (for example, N, N-dimethylformamide and N-methylpyrrolidone) and aromatic hydrocarbon solvents (for example, toluene).

  The pigment particles (a1) can be further subjected to purification treatment or classification treatment. The purification treatment is preferably performed until a predetermined concentration is obtained using a separation membrane such as an ultrafiltration membrane, a reverse osmosis membrane, and an electrodialysis membrane. The classification treatment can be performed by a method such as centrifugation or filtration. Examples of the method for performing the classification process by centrifugation include a classifying process using a horizontal decanter, a rotor type high-speed centrifuge, a vertical centrifuge, a separation plate type separator, and the like. Examples of the method for performing the classification process by filtration include a method using a depth filter, a pleated filter, a membrane filter, and the like, and further performing a classification process effectively by using them in multiple stages.

The volume average particle diameter of the pigment particles (a1) is preferably 30 to 180 nm, more preferably 60 to 150 nm, from the viewpoint of the coloring power of the pigment.
The volume average particle size in the present invention is measured by a dynamic light scattering method with a particle size measuring device LB-550 manufactured by Horiba, Ltd. in an environment of 23 ° C. and 55% RH.

  The volume average particle diameter of the pigment particles (a1) can be controlled by the type of hydrophilic group bonded to the surface, the type of dispersant, the type of pigment, the dispersion treatment method, the dispersion treatment time, and the like.

<Polyurethane resin particles (b)>
Examples of the polyurethane resin particles (b) in the present invention include resin particles obtained by dispersing the polyurethane resin (U) in an aqueous medium.

  The polyurethane resin (U) is obtained, for example, by reacting a polyol (e), an organic polyisocyanate (f), a compound (g) having a hydrophilic group and two active hydrogen atoms, and a chain extender (h). A polyurethane resin (U) may be used individually by 1 type, or may use 2 or more types together.

  Examples of the polyol (e) include a polyol (e1) having a number average molecular weight (hereinafter abbreviated as Mn) of 300 or more and a low molecular polyol (e2) having an Mn or chemical formula weight of less than 300. Polyol (e) may be used individually by 1 type, or may use 2 or more types together.

Mn in the present invention can be measured by gel permeation chromatography, for example, under the following conditions.
Apparatus: “Waters Alliance 2695” [manufactured by Waters]
Column: “Guardcolumn Super HL” (1), “TSKgel SuperH2000, TSKgel SuperH3000, TSKgel SuperH4000 (all manufactured by Tosoh Corporation)”
Sample solution: 0.25 wt% tetrahydrofuran solution solution injection amount: 10 μl
Flow rate: 0.6 ml / min Measurement temperature: 40 ° C
Detector: Refractive index detector Reference material: Standard polyethylene glycol

  Examples of the polyol (e1) having Mn of 300 or more include polyether polyol (e11) and polyester polyol (e12).

  Examples of the polyether polyol (e11) include aliphatic polyether polyols and aromatic ring-containing polyether polyols.

  Examples of the aliphatic polyether polyol include polyoxyalkylene polyols [polyethylene glycol, polypropylene glycol, poly (oxyethylene / oxypropylene) polyol and polyoxytetramethylene glycol].

  Examples of the aliphatic polyether polyol include PTMG1000 [poly (oxytetramethylene) glycol with Mn = 1,000, manufactured by Mitsubishi Chemical Corporation], PTMG2000 [poly (oxytetramethylene) glycol with Mn = 2,000, Mitsubishi Chemical Corporation. Manufactured by], PTMG3000 [poly (oxytetramethylene) glycol with Mn = 3,000, manufactured by Mitsubishi Chemical Corporation], PTGL2000 [modified poly (oxytetramethylene) glycol with Mn = 2,000, Hodogaya Chemical Manufactured by Kogyo Co., Ltd.], PTGL3000 [modified poly (oxytetramethylene) glycol with Mn = 3,000, manufactured by Hodogaya Chemical Co., Ltd.], and Sanniks Diol GP-3000 [polypropylene ether triol with Mn = 3,000. Sanyo Chemical Industries, Ltd.].

  Aromatic polyether polyols include bisphenol A EO adducts [bisphenol A EO 2 mol adduct, bisphenol A EO 4 mol adduct, bisphenol A EO 6 mol adduct, bisphenol A EO 8 mol adduct, bisphenol A EO adduct. EO 10 mol adduct and bisphenol A EO 20 mol adduct etc.] and bisphenol A propylene oxide (hereinafter abbreviated as PO) adduct [bisphenol A PO2 mol adduct, bisphenol A PO3 mol adduct, bisphenol A PO5 Mole adducts etc.] and other polyols having a bisphenol skeleton, and resorcin EO or PO adducts.

  Mn of (e11) is preferably 300 or more, more preferably 300 to 10,000, and particularly preferably 300 to 6,000, from the viewpoint of mechanical properties of the polyurethane resin (U).

  Examples of the polyester polyol (e12) include condensed polyester polyols, polylactone polyols, polycarbonate polyols, and castor oil-based polyols.

  Examples of the condensed polyester polyol include polyester polyols of low molecular weight (Mn or chemical formula amount less than 300) polyhydric alcohol and polyhydric carboxylic acid having 2 to 10 carbon atoms or ester-forming derivatives thereof.

Examples of the low molecular weight polyhydric alcohol include Mn or a divalent to octavalent or higher aliphatic polyhydric alcohol having a chemical formula amount of less than 300 and a Mn or a divalent to octavalent or higher phenol having a chemical formula amount of less than 300. AO low molar adducts can be used.
Among the low molecular weight polyhydric alcohols that can be used for the condensed polyester polyol, ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexane glycol, bisphenol A EO or PO low Molar adducts and mixtures thereof.

  Examples of the polyvalent carboxylic acid having 2 to 10 carbon atoms or ester-forming derivatives thereof that can be used in the condensed polyester polyol include aliphatic dicarboxylic acids (succinic acid, adipic acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, etc.) , Alicyclic dicarboxylic acids (such as dimer acid), aromatic dicarboxylic acids (such as terephthalic acid, isophthalic acid and phthalic acid), trivalent or higher polycarboxylic acids (such as trimellitic acid and pyromellitic acid), these Anhydrides (succinic anhydride, maleic anhydride, phthalic anhydride, trimellitic anhydride, etc.), acid halides thereof (adipic acid dichloride, etc.), low molecular weight alkyl esters thereof (dimethyl succinate, dimethyl phthalate, etc.) A mixture of these is listed.

  Specific examples of the condensed polyester polyol include polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyhexamethylene isophthalate diol, polyhexamethylene terephthalate diol, polyneopentyl adipate diol, polyethylene propylene adipate diol, polyethylene Butylene adipate diol, polybutylene hexamethylene adipate diol, polydiethylene adipate diol, poly (polytetramethylene ether) adipate diol, poly (3-methylpentylene adipate) diol, polyethylene azelate diol, polyethylene sebacate diol, polybutylene aze Rate diol, polybutylene sebacate diol and poly Oh pliers Rutere terephthalate diol.

  As a commercially available product of condensed polyester polyol, Sanester 2610 [polyethylene adipate diol with Mn = 1,000, manufactured by Sanyo Chemical Industries, Ltd.], Sanester 4620 [polytetramethylene adipate diol with Mn = 2,000], Sanester 2620 [polyethylene adipate diol with Mn = 2,000, manufactured by Sanyo Chemical Industries, Ltd.], Kuraray polyol P-2010 [poly-3-methyl-1,5-pentane adipate diol with Mn = 2,000], Kuraray polyol P-3010 [poly-3-methyl-1,5-pentane adipate diol with Mn = 3,000] and Kuraray polyol P-6010 [poly-3-methyl-1,5-pentane with Mn = 6,000 Adipate diol] and the like.

The polylactone polyol is a polyadduct of lactone to the low molecular weight polyhydric alcohol, and examples of the lactone include lactones having 4 to 12 carbon atoms (γ-butyrolactone, γ-valerolactone, ε-caprolactone, etc.). It is done.
Specific examples of the polylactone polyol include polycaprolactone diol, polyvalerolactone diol, and polycaprolactone triol.

  Examples of the polycarbonate polyol include the low molecular weight polyhydric alcohol, a low molecular carbonate compound (an alkyl group having 1 to 6 carbon atoms dialkyl carbonate, an alkylene carbonate having 2 to 6 carbon atoms, and an aryl having 6 to 9 carbon atoms). And a polycarbonate polyol produced by condensation with a dealcoholization reaction. Two or more low molecular weight polyhydric alcohols and alkylene carbonates may be used in combination.

  Specific examples of the polycarbonate polyol include polyhexamethylene carbonate diol, polypentamethylene carbonate diol, 3-methyl-5-pentane-carbonate diol, polytetramethylene carbonate diol, and poly (tetramethylene / hexamethylene) carbonate diol (1, Diols obtained by condensing 4-butanediol and 1,6-hexanediol with a dialkyl carbonate while causing dealcoholization reaction).

  Examples of commercially available polycarbonate polyols include NIPPOLAN 980R [polyhexamethylene carbonate diol with Mn = 2,000, manufactured by Nippon Polyurethane Industry Co., Ltd.], and Kuraray polyol C-3090 [poly (3-methyl- with Mn = 3,000). 5-pentanediol / hexamethylene) carbonate diol] and T4672 [poly (tetramethylene / hexamethylene) carbonate diol of Mn = 2,000, manufactured by Asahi Kasei Chemicals Corporation].

  The castor oil-based polyol includes castor oil and modified castor oil modified with polyol or AO. Modified castor oil can be produced by transesterification of castor oil and polyol and / or AO addition. Castor oil-based polyols include castor oil, trimethylolpropane-modified castor oil, pentaerythritol-modified castor oil, and EO (4 to 30 mol) adduct of castor oil.

  Among the polyester polyols (e12), preferred are condensed polyester polyols and polylactone polyols.

  As the low molecular polyol (e2) having an Mn or a chemical formula amount of less than 300, aliphatic dihydric alcohols (ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6 -Hexanediol, 1,8-octanediol, 1,4-cyclohexanedimethanol and their EO and / or PO adducts), aliphatic trihydric alcohols (glycerin, trimethylolpropane and their EO and / or PO) Adducts, etc.) and tetrahydric or higher aliphatic alcohols (pentaerythritol, sorbitol and their EO and / or PO adducts, etc.). Among (e2), preferred from the viewpoint of water resistance and heat-resistant yellowing are divalent and trivalent aliphatic alcohols, and the aliphatic trivalent alcohols can form a crosslinked structure in the polyurethane resin particles, This is preferable in that the effect of improving the water resistance and chemical resistance of the urethane film can be obtained. As the aliphatic dihydric alcohol, ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol and 1,6-hexanediol are particularly preferable, and as the aliphatic trihydric alcohol, trimethylolpropane is particularly preferable.

  The organic polyisocyanate (f) used in the polyurethane resin (U) is an aromatic polyisocyanate having 2 to 3 or more isocyanate groups and having 6 to 20 carbon atoms (excluding carbon in the isocyanate groups, the same applies hereinafter). Isocyanate (f1), C2-C18 aliphatic polyisocyanate (f2), C4-C15 alicyclic polyisocyanate (f3), C8-C15 araliphatic polyisocyanate (f4) and ( and derivatives of f1) to (f4) (isocyanurate).

  Examples of the aromatic polyisocyanate having 6 to 20 carbon atoms (f1) include 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate (TDI), 4,4'- or 2,4′-diphenylmethane diisocyanate (MDI), 1,5-naphthylene diisocyanate, 4,4 ′, 4 ″ -triphenylmethane triisocyanate, m- or p-isocyanatophenylsulfonyl isocyanate, crude MDI, etc. It is done.

  Examples of the aliphatic polyisocyanate (f2) having 2 to 18 carbon atoms include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, and 2- And isocyanatoethyl-2,6-diisocyanatohexanoate.

  Examples of the alicyclic polyisocyanate (f3) having 4 to 15 carbon atoms include isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, and methylcyclohexylene diisocyanate (hydrogenated TDI). Bis (2-isocyanatoethyl) -4-cyclohexene-1,2-dicarboxylate and 2,5- or 2,6-norbornane diisocyanate.

  Examples of the araliphatic polyisocyanate (f4) having 8 to 15 carbon atoms include m- or p-xylylene diisocyanate (XDI) and α, α, α ′, α′-tetramethylxylylene diisocyanate (TMXDI). It is done.

  Among the organic polyisocyanates (f), (f2) and (f3) are preferable from the viewpoint of mechanical strength and weather resistance of the obtained film, (f3) is more preferable, and IPDI and hydrogenated MDI are particularly preferable. It is. The organic polyisocyanate (f) may be used alone or in combination of two or more.

Examples of the compound (g) having a hydrophilic group and two active hydrogen atoms include a compound (g1) having an anionic group and an active hydrogen atom and a compound (g2) having a cationic group and an active hydrogen atom.
(G1) includes a carboxyl group as an anionic group and a compound having 2 to 10 carbon atoms [dialkylol alkanoic acid (2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2 , 2-dimethylol heptanoic acid and 2,2-dimethylol octanoic acid, etc.), tartaric acid and amino acids (for example, glycine, alanine and valine)], sulfonic acid groups as anionic groups, and having 2 to 16 carbon atoms. Compound [3- (2,3-dihydroxypropoxy) -1-propanesulfonic acid and sulfoisophthalic acid di (ethylene glycol) ester, etc.], containing a sulfamic acid group as an anionic group, and having 2 to 10 carbon atoms Compounds [N, N-bis (2-hydroxylethyl) sulfamic acid, etc.] etc. and these compounds are neutralized with a neutralizing agent (k). Salt and the like.

Examples of the neutralizing agent (k) used for the salt of (g1) include ammonia, amine compounds having 1 to 20 carbon atoms, and alkali metal hydroxides (such as sodium hydroxide, potassium hydroxide, and lithium hydroxide). It is done.
Examples of the amine compound having 1 to 20 carbon atoms include primary amines such as monomethylamine, monoethylamine, monobutylamine and monoethanolamine, secondary amines such as dimethylamine, diethylamine, dibutylamine, diethanolamine, diisopropanolamine and methylpropanolamine. Examples include amines and tertiary amines such as trimethylamine, triethylamine, dimethylethylamine, dimethylmonoethanolamine and triethanolamine.

  As the neutralizing agent (k) used in the salt of (g1), a compound having a high vapor pressure at 25 ° C. is preferable from the viewpoint of the drying property of the resulting polyurethane resin aqueous dispersion and the water resistance of the resulting film. . From such a viewpoint, as the neutralizing agent (k) used in the salt of (g1), ammonia, monomethylamine, monoethylamine, dimethylamine, diethylamine, trimethylamine, triethylamine and dimethylethylamine are preferable.

  Among (g1), 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid and salts thereof are preferable from the viewpoint of the resin physical properties of the obtained film and the dispersion stability of the aqueous polyurethane resin dispersion. More preferred are neutralized salts of 2,2-dimethylolpropionic acid and 2,2-dimethylolbutanoic acid with ammonia or an amine compound having 1 to 20 carbon atoms.

  As the compound (g2) having a cationic group and an active hydrogen atom, a compound having a tertiary amino group as a cationic group and a hydroxyl group as an active hydrogen atom, a tertiary amino group-containing diol having 1 to 20 carbon atoms [ N-alkyl dialkanolamine (N-methyldiethanolamine, N-propyldiethanolamine, N-butyldiethanolamine, N-methyldipropanolamine, etc.) and N, N-dialkylmonoalkanolamine (N, N-dimethylethanolamine, etc.), etc. ] The salt which neutralized compounds, such as] with the neutralizing agent (k) is mentioned.

Examples of the neutralizing agent (k) used in (g2) include monocarboxylic acids having 1 to 10 carbon atoms (such as formic acid, acetic acid and propanoic acid), carbonic acid, dimethyl carbonate, dimethyl sulfate, methyl chloride and benzyl chloride. It is done.
The neutralizing agent (k) used in (g) and (g) may be used alone or in combination of two or more.

The amount of (g) used is such that the content of the hydrophilic group in (U) is preferably 0.5 to 5.0% by weight, more preferably 0.5 to 4 based on the weight of (U). 0.8% by weight, particularly preferably 0.5 to 4.5% by weight.
The content of the hydrophilic group in the present invention means the weight percent of the unneutralized cationic group or anionic group, and does not include the weight of the counter ion. For example, the content of the hydrophilic group in (g1) is such that in the case of triethylamine salt of 2,2-dimethylolpropionic acid, the weight percentage of the carboxyl group (—COOH) is 3- (2,3-dihydroxypropoxy). In the case of triethylamine salt of -1-propanesulfonic acid, it refers to the weight percent of the sulfo group (—SO ₃ H). Further, the content of the hydrophilic group in (g2) refers to the weight% of only the nitrogen atom in the tertiary amino group.

  As chain extender (h), Mn or low molecular weight polyol (e2) having a chemical formula of less than 300, water, diamine having 2 to 10 carbon atoms (ethylenediamine, propylenediamine, hexamethylenediamine, isophoronediamine, toluenediamine, piperazine, etc. ), Polyalkylene polyamines having 2 to 10 carbon atoms (such as diethylenetriamine, triethylenetetramine and tetraethylenepentamine), hydrazine or derivatives thereof (dibasic acid dihydrazide such as adipic acid dihydrazide), polyepoxy compounds having 2 to 30 carbon atoms ( 1,6-hexanediol diglycidyl ether and trimethylolpropane polyglycidyl ether) and amino alcohols having 2 to 10 carbon atoms (ethanolamine, diethanolamine, 2-amino-2-methylpropano) And triethanolamine, etc.) and the like. A chain extender (h) may be used individually by 1 type, or may use 2 or more types together.

  In the polyurethane resin (U) in the present invention, a reaction terminator (j) can be used if necessary. As the reaction terminator (j), monoalcohols having 1 to 8 carbon atoms (methanol, ethanol, isopropanol, cellosolves and carbitols), monoamines having 1 to 10 carbon atoms (monomethylamine, monoethylamine, mono Mono- or dialkylamines such as butylamine, dibutylamine and monooctylamine; mono- or dialkanolamines such as monoethanolamine, diethanolamine and diisopropanolamine). The reaction terminator (j) may be used alone or in combination of two or more.

  The polyurethane resin (U) in the present invention can contain additives such as antioxidants, anti-coloring agents, weathering stabilizers, plasticizers, and mold release agents as necessary. The amount of these additives used is preferably 10% by weight or less, more preferably 3% by weight or less, and particularly preferably 1% by weight or less based on the weight of (U).

  The urethane group content of the polyurethane resin (U) is preferably 0.5 to 3.0 mmol / g, more preferably 0.7 to 2.5 mmol, from the viewpoint of mechanical properties, elongation at break, and adhesion of the resulting film. / G, particularly preferably 0.9 to 2.0 mmol / g.

  The urea group content of the polyurethane resin (U) is 1.5 mmol / g or less based on the weight of (U) from the viewpoints of film-forming properties and water resistance, elongation at break and adhesion of the resulting film. Preferably, it is 1.2 mmol / g or less, particularly preferably 1.0 mmol / g or less, and most preferably 0.8 mmol / g or less.

  The Mn of the polyurethane resin (U) is 5,000 or more, and preferably 5,000 or more, more preferably 8,000 or more, and most preferably 10 from the viewpoints of mechanical properties, chemical resistance, and the like of the resulting film. 1,000 or more. When the Mn is 5,000 or more, the resulting film has good mechanical properties and chemical resistance.

Mn of the polyurethane resin (U) can be measured, for example, under the following conditions by gel permeation chromatography.
Apparatus: “HLC-8220GPC” [manufactured by Tosoh Corporation]
Column: “Guardcolumn α” + “TSKgel α-M” [both manufactured by Tosoh Corporation]
Sample solution: 0.125% by weight dimethylformamide solution Injection amount: 100 μl
Flow rate: 1 ml / min Measurement temperature: 40 ° C
Detector: Refractive index detector Reference material: Standard polystyrene

  The volume average particle diameter of the polyurethane resin particles (b) is preferably 20 to 120 nm, more preferably 20 to 80 nm, from the viewpoint of the stability of the composite particle aqueous dispersion.

  The volume average particle diameter of the polyurethane resin particles (b) can be controlled by, for example, an acid value of a urethane prepolymer (t) described later, a neutralization rate during dispersion, and the dispersant (d) added during dispersion. For example, by increasing the acid value of (t), increasing the neutralization rate of (t) at the time of dispersion, or adding a dispersant (d) at the time of dispersion, the volume average particle diameter of (b) is increased. Can be small.

<Composite particle aqueous dispersion (X)>
In the composite particle aqueous dispersion (X) of the present invention, for example, the pigment particle (a1) or the dispersant (d) is adsorbed to the pigment particle (a1) on the aqueous dispersion (B) containing the polyurethane resin particles (b). The aqueous dispersion (A) containing the particles (a2) is put into the aqueous dispersion (B) under stirring (aggregation step).

  In the aggregation step, the ratio of the volume average particle diameter of the pigment particles (a1) to the volume average particle diameter of the polyurethane resin particles (b) [volume average particle diameter of (a1) / volume average particle diameter of (b)] is specified. By setting the absolute value of the difference between the zeta potential of (a1) or (a2) and the zeta potential of the polyurethane resin particles (b) to a specific range, and setting the range to (a1) or (a2) (B) can be aggregated on the surface.

  Furthermore, the composite particle aqueous dispersion having more excellent storage stability can be obtained by heating to a temperature not lower than the glass transition temperature (Tg) of the polyurethane resin (U) and fusing the aggregated particles.

<Aqueous dispersion (A)>
The aqueous dispersion (A) containing the particles (a2) formed by adsorbing the dispersant (d) on the pigment particles (a1) or the pigment particles (a1) is, for example, self-dispersing pigment particles as the pigment particles (a1). It can be obtained by a method of dispersing it in an aqueous medium, or a method of dissolving the dispersing agent (d) in an aqueous medium and then adding and mixing the pigment particles (a1).

  Examples of the apparatus for dispersing include an apparatus using media such as an attritor, ball mill, bead mill, sand mill, and dyno mill, and a dispersing apparatus such as a jet mill and an ultrasonic disperser that do not use media.

The zeta potential of the pigment particles (a1) and the particles (a2) is preferably −100 to 0 mV, more preferably −100 to −20 mV, from the viewpoint of dispersion stability of the composite particles.
The zeta potential in the present invention is measured by a laser Doppler method with a particle size measuring device LB-550 manufactured by Horiba, Ltd. after the particle dispersion is diluted with ion-exchanged water so that the solid content becomes 0.01% by weight.

  The zeta potential of the pigment particles (a1) is controlled by adding the acid value of (a1), the neutralization rate, the pH of the aqueous dispersion (A), and adding a nonionic or anionic surfactant to (A). it can. For example, by increasing the acid value of (a1), increasing the neutralization rate of (a1), increasing the pH of (A), or adding an anionic surfactant, the zeta potential of (a1) is absolute The negative value can be a large negative value, the acid value of (a1) is reduced, the neutralization rate of (a1) is reduced, the pH of (A) is reduced, or a nonionic surfactant is added Thus, the zeta potential of (a1) can be set to a negative value having a small absolute value.

  The pH adjuster is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include alkanolamines, alkali metal hydroxides, ammonium hydroxides, phosphonium hydroxides, and alkali metal carbonates. Examples include salts.

  Examples of the alkanolamine include diethanolamine, triethanolamine, and 2-amino-2-ethyl-1,3-propanediol. Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, and potassium hydroxide. Examples of the ammonium hydroxide include ammonium hydroxide and quaternary ammonium hydroxide. Examples of the phosphonium hydroxide include quaternary phosphonium hydroxide. Examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, and potassium carbonate.

<Aqueous dispersion (B)>
The aqueous dispersion (B) containing the polyurethane resin particles (b) is produced, for example, by the following steps.
(I) A step of obtaining a urethane prepolymer (t).
(Ii) A step of neutralizing with the neutralizing agent (k).
(Iii) The obtained neutralized product is dispersed in water and reacted with a chain extender (h), a reaction terminator (j) and / or water, and if necessary, an organic solvent (s) is used. Removing.

<Manufacturing process (i)>
The urethane prepolymer (t) is obtained by reacting the polyol (e), the organic polyisocyanate (f), and the compound (g) having a hydrophilic group and two active hydrogen atoms by heating with a heatable facility. can get. For example, (e), (f) and (g) are charged in a container, and after uniform stirring, a method of heating without stirring in a heating dryer or heating furnace, a simple pressure reactor (autoclave), a flask, Examples thereof include a method of reacting by heating with stirring or kneading in a uniaxial or biaxial kneader, a plast mill or a universal kneader. Among them, the method of heating and reacting while stirring or kneading increases the homogeneity of the obtained (t), and improves the mechanical properties, durability, chemical resistance, wear resistance, etc. of the obtained film. It is preferable because it is excellent.

  The reaction temperature for producing the urethane prepolymer (t) is preferably 60 to 120 ° C, more preferably 60 to 110 ° C, particularly preferably from the viewpoint of suppressing the formation of the allophanate group and burette group of (t). 60-100 ° C. The time for producing (t) can be appropriately selected depending on the equipment used, but generally 1 minute to 100 hours is preferable, more preferably 3 minutes to 30 hours, and particularly preferably 5 minutes. ~ 20 hours. If it is this range, (t) which can fully exhibit the effect of the present invention will be obtained.

  The urethane prepolymer (t) can be diluted with the organic solvent (s). Of the organic solvents (s), amide solvents are preferred from the viewpoint of solubility of the urethane prepolymer (t). The organic solvent (s) may be used alone or in combination of two or more.

  The organic solvent (s) may be added before the urethanization reaction, during the urethanization reaction, after the urethanization reaction, or before the dispersion, but is added before the urethanization reaction from the viewpoint of the uniformity of the reaction system. It is preferable.

  In order to control the urethanization reaction rate, known reaction catalysts (such as tin octylate and bismuth octylate) and reaction retarders (such as phosphoric acid) can be used. The addition amount of these catalysts or reaction retarders is preferably 0.001 to 3% by weight, more preferably 0.005 to 2% by weight, particularly preferably 0.01 to 1% by weight, based on the weight of (t). %.

<Manufacturing process (ii)>
If necessary, the hydrophilic group part introduced into the urethane prepolymer (t) is neutralized with a neutralizing agent (k). The neutralizing agent (k) may be added before the urethanization reaction, during the urethanization reaction, after the urethanization reaction, before the dispersion, during the dispersion, or after the dispersion, but the aqueous dispersion (B) and From the viewpoint of dispersion stability of the composite particle aqueous dispersion (X), it is preferably added before or during dispersion. Further, if necessary, the neutralizing agent (k) volatilized during the solvent removal may be added after the solvent removal, and the type of the neutralizing agent to be added can be freely selected from those described above.

  The amount of (k) used is adjusted so that the carboxylate group content based on the weight of the polyurethane resin (U) is 23 to 80 mg / g from the viewpoint of the stability of the aqueous composite particle dispersion (X). The neutralization rate of the carboxyl group in the neutralization step is preferably 20 to 100%, more preferably 60 to 100% from the viewpoint of dispersion stability.

<Manufacturing process (iv)>
Examples of a method for dispersing the neutralized product obtained in step (iii) in an aqueous medium include, for example, a chain extender (h) and, if necessary, an organic solvent (s), a dispersant (d) and a reaction terminator (j). Disperse in an aqueous medium in the presence of the reaction and carry out the reaction [water, chain extension by (h) and, if necessary, stop by (j)] until the isocyanate group is substantially eliminated, and if necessary, the organic solvent (s) used The method of distilling off is mentioned.

  The organic solvent (s) used in the aqueous medium is preferably a water-soluble organic solvent from the viewpoint of dispersibility. When the organic solvent (s) is used, it may be distilled off if necessary during and / or after the production of the aqueous composite particle dispersion (X).

  The zeta potential of the polyurethane resin particles (b) is preferably −100 to 0 mV, more preferably −100 to −20 mV, from the viewpoint of dispersion stability of the composite particles (c).

  The zeta potential of the polyurethane resin particles (b) can be determined by adding a nonionic or anionic surfactant to the acid value of (b), the neutralization rate, the pH of the aqueous dispersion (B) and (B), etc. Can be controlled. For example, by increasing the acid value of (b), increasing the neutralization rate of (b), increasing the pH of (B), or adding an anionic surfactant, the zeta potential of (b) is absolutely The negative value can be a large negative value, and the acid value of (b) is reduced, the neutralization rate of (b) is reduced, the pH of (B) is reduced, or a nonionic surfactant is added. Thus, the zeta potential in (b) can be set to a negative value having a small absolute value.

<Formation of composite particles (c)>
Particles formed by adsorbing the dispersant (d) on the pigment particles (a1) or the pigment particles (a1) by adding the aqueous dispersion (A) while stirring the aqueous dispersion (B) (aggregation step) ( The polyurethane resin particles (b) are aggregated on the surface of a2) to obtain composite particles (c).

  For aggregation, the ratio of the volume average particle diameter of the pigment particles (a1) to the volume average particle diameter of the polyurethane resin particles (b) [volume average particle diameter of (a1) / volume average particle diameter of (b)]. It is necessary to adjust to the range of 1.5-7, and to adjust the absolute value of the difference of the zeta potential of (a1) or (a2) and the zeta potential of the polyurethane resin particle (b) to the range of 30-100 mV.

  The ratio of the volume average particle diameter of the pigment particles (a1) to the volume average particle diameter of the polyurethane resin particles (b) is adjusted in the range of 2.5 to 4 from the viewpoint of dispersion stability of the composite particles (c). The absolute value of the difference between the zeta potential of (a1) or (a2) and the zeta potential of the polyurethane resin particles (b) is in the range of 50 to 100 mV from the viewpoint of the dispersion stability of the composite particles (c). It is preferable to adjust.

  In order to set the absolute value of the ratio between the volume average particle size and the difference between the zeta potentials within a predetermined range, the volume average particle size of (a1) and (b) and (a1), (a2) and (b) It is preferable to prepare an aqueous dispersion (A) and an aqueous dispersion (B) by setting the zeta potential.

  The temperature in the aggregation step is preferably 5 to 100 ° C., and more preferably 20 to 50 ° C. from the viewpoint of dispersion stability of the composite particles (c) during the aggregation process. The time required for the aggregation step is preferably 1 minute to 24 hours, and preferably 1 hour to 24 hours from the viewpoint of dispersion stability of the composite particles (c).

  The weight ratio of the polyurethane resin particles (b) to the pigment particles (a1) [weight of (b) / weight of (a1)] is preferably from the viewpoint of dispersion stability of the composite particles (c) and adhesion to the substrate. It is 1.5-5, More preferably, it is 2-3.

  The volume average particle diameter of the composite particles (c) is preferably 70 to 200 nm, more preferably 70 nm to 150 nm, from the viewpoint of the stability of the composite particle aqueous dispersion (X).

The state of the composite particles (c) in the composite particle aqueous dispersion (X) can be observed using a transmission electron microscope (TEM) by preparing a sample by the method described below.
(1) First, the composite particles (c) obtained by removing the aqueous medium from (X) are embedded in an acrylic resin or the like and dyed with ruthenium tetroxide.
(2) Next, the dyed sample is cut out to a thickness of 80 nm in a state cooled to −80 ° C. with an ultramicrotome, and observed with TEM. Examples of the TEM to be used include “thermal FE-SEM JSM7000F” [manufactured by JEOL Ltd.] and “cold FE-TEM” [manufactured by Hitachi High-Technologies Corporation].

<Water-based ink (Y)>
The aqueous ink (Y) of the present invention contains the composite particle aqueous dispersion (X) of the present invention. The composite particle aqueous dispersion (X) may be used alone or in combination of two or more.

  The water-based ink (Y) includes other components appropriately selected as necessary, for example, a crosslinking agent, a viscosity modifier, an antifoaming agent, an antiseptic, a deterioration preventing agent, a stabilizer, an antifreezing agent, an organic solvent, and a surfactant. One type or two or more types of agents and water can be contained.

  Examples of crosslinking agents include water-soluble or aqueous medium-dispersible amino resins, water-soluble or aqueous medium-dispersible polyepoxides, water-soluble or aqueous medium-dispersed blocked polyisocyanate compounds, polyethylene urea, water-soluble or aqueous medium-dispersible compounds. Examples thereof include polycarbodiimide resins and water-soluble or aqueous medium-dispersible polyoxazoline resins. The amount of the crosslinking agent used is preferably such that the number of moles of the reactive group possessed by the crosslinking agent is 0.05 to 2 times the number of moles of the reactive group possessed by the aqueous composite particle dispersion (X). Is an amount of 0.1 to 1 times.

Viscosity modifiers include thickeners such as inorganic viscosity modifiers (such as sodium silicate and bentonite), cellulose-based viscosity modifiers (such as methylcellulose, carboxymethylcellulose and hydroxymethylcellulose with Mn of 20,000 or more), proteins System viscosity modifiers (casein, casein soda, casein ammonium, etc.), acrylics (such as sodium polyacrylate and ammonium polyacrylate with Mn of 20,000 or more) and vinyl viscosity modifiers (Mn of 20,000 or more) Polyvinyl alcohol).
Examples of antifoaming agents include long-chain alcohols (such as octyl alcohol), sorbitan derivatives (such as sorbitan monooleate), and silicone oils (such as polymethylsiloxane and polyether-modified silicone).

Examples of the preservative include organic nitrogen sulfur compound preservatives and organic sulfur halide preservatives.
Deterioration inhibitors and stabilizers (such as UV absorbers and antioxidants) include hindered phenol, hindered amine, hydrazine, phosphorus, benzophenone or benzotriazole degradation inhibitors and stabilizers. .
Examples of the antifreezing agent include ethylene glycol and propylene glycol.
The contents of the viscosity modifier, antifoaming agent, preservative, deterioration preventing agent, stabilizer and antifreezing agent are each preferably 5% by weight or less, more preferably 3% by weight based on the weight of the aqueous ink (Y). % Or less.

  The organic solvent used in the water-based ink is used for the purpose of improving the appearance of the coated film after drying and for the purpose of delaying drying in order to prevent clogging in the coating or printing line. Alcohol (methanol, ethanol, propanol, etc.), C1-20 glycols (ethylene glycol, propylene glycol, diethylene glycol, etc.), C1-20 trivalent or higher alcohols (glycerin, etc.), and C1-20 The cellosolves such as methyl and ethyl cellosolve are preferably used. The addition amount of the organic solvent is preferably 80% by weight or less, more preferably 70% by weight or less, based on the weight of the water-based ink (Y).

Examples of the surfactant include acetylene glycol surfactants, acetylene alcohol surfactants, and polysiloxane surfactants. The addition of a surfactant improves the drying properties of images such as printing.
Examples of the acetylene glycol surfactant and the acetylene alcohol surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol and 2,4,7,9-tetramethyl-5- Examples include AO adducts of decyne-4,7-diol and AO adducts of 2,4-dimethyl-5-decyn-4-ol and 2,4-dimethyl-5-decyn-4-ol. Examples include Olphine 104 and Olphine E1010 [manufactured by Nissin Chemical Industry Co., Ltd.], Surfinol 465 and Surfinol 61 [manufactured by Nissin Chemical Industry Co., Ltd.], and the like.
Examples of the polysiloxane-based surfactant include BYK-347 and BYK-348 (manufactured by Big Chemie Japan).

The aqueous ink (Y) of the present invention is produced by mixing and stirring the composite particle aqueous dispersion (X) of the present invention and each of the above components. When mixing, all the components may be mixed at the same time, or each component may be added stepwise and mixed.
The solid content concentration of the water-based ink (Y) is preferably 3 to 70% by weight, more preferably 7 to 60% by weight.

  The aqueous ink (Y) of the present invention can be used for applications such as offset printing ink, relief printing ink, gravure printing ink, silk printing ink, ink jet recording ink, and color filter.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these. Hereinafter, the part means part by weight.

<Production Examples 1-4>
A simple pressure reactor equipped with a stirrer and a heating device has the types and parts of polyols (e1) and (e2), organic polyisocyanate (f), a hydrophilic group and two active hydrogen atoms shown in Table 1. The compound (g) and the organic solvent (s) were charged and stirred at 85 ° C. for 10 hours to carry out a urethanization reaction to produce a solvent solution of urethane prepolymers (t-1) to (t-4). To this, the type and number of neutralizing agents (k) shown in Table 1 were added and homogenized, and then the mixture was dispersed by adding the number of ion-exchanged water shown in Table 1 while stirring at 200 rpm. The type and number of parts of chain extender (h) shown in Table 1 were added to the obtained dispersion, and the organic solvent was distilled off at 65 ° C. under reduced pressure for 8 hours. Furthermore, the resin concentration and the zeta potential were adjusted by adding the amount of ion-exchanged water distilled together with the organic solvent and the pH adjusting agent of the type and number of parts shown in Table 1, and the polyurethane resin particle aqueous dispersion (B-1 ) To (B-4) were obtained. Table 1 shows the physical property values of the produced urethane prepolymers (t-1) to (t-4) and the polyurethane resin particle aqueous dispersions (B-1) to (B-4). In addition, pH in Table 1 and Table 2 was measured at a temperature of 25 ° C. using “Twin pH meter B-212” manufactured by Horiba, Ltd.

<Examples 1-2 and Comparative Example 1>
A device equipped with a stirrer and a heating device, and the type and number of self-dispersing pigment particle aqueous dispersions [Aqua-Black162: manufactured by Tokai Carbon Co., Ltd., solid content 19% by weight], ion-exchanged water and polyurethane The resin particle aqueous dispersion (B) is stirred and mixed at 65 ° C. for 8 hours under normal pressure, and the composite particle aqueous dispersions (X-1) to (X-2) and the comparative composite particle aqueous dispersion (X ′ -1) was obtained.

<Examples 3 to 4 and Comparative Example 2>
The pigment particle aqueous dispersions (A-2) and (A-3) are dispersed by dispersing the types and number of pigment particles (a1), dispersant (d) and ion-exchanged water shown in Table 2 in a bead mill over 10 hours. Obtained. Next, 30 parts of the pigment particle aqueous dispersion (A) of the type shown in Table 2 and the polyurethane resin particle aqueous dispersion (B) of the type shown in Table 2 are placed at 40 ° C. under normal pressure in an apparatus equipped with a stirrer and a heating device. Were mixed and stirred for 4 hours to obtain composite particle aqueous dispersions (X-3) to (X-4) and comparative composite particle aqueous dispersion (X′-2). Table 2 shows the physical property values of the pigment particle aqueous dispersion (A), the polyurethane resin particle aqueous dispersion (B), and the composite particle aqueous dispersion.

<Examples 5-8 and Comparative Examples 3-4>
Composite particle aqueous dispersions (X-1) to (X-4) obtained in Examples 1 to 4 and Comparative Examples 1 to 2 and comparative composite particle aqueous dispersions (X′-1) to (X ′) -2) 100 parts, 20 parts of propylene glycol as a solvent, 20 parts of glycerin, 1 part of Surfynol 104 [manufactured by Nissin Chemical Industry Co., Ltd.] as a surfactant and 9 parts of ion-exchanged water at 25 ° C. for 30 minutes By mixing, water-based inks (Y-1) to (Y-4) and comparative water-based inks (Y′-1) to (Y′-2) were obtained.
Table 3 shows the results of evaluating the adhesion and ink storage stability of the obtained water-based ink by the following evaluation methods.

<Adhesion evaluation method>
A water-based ink was applied to a coated paper of 5 cm in length and 20 cm in width [“Aurora Coat” {manufactured by Nippon Paper Industries Co., Ltd.}] so that the film thickness after drying was 2 μm, and dried at 140 ° C. for 10 minutes. Was made. Eleven incisions were made on the surface of the coating film at 1 mm intervals in the vertical and horizontal directions, and a peel test was performed using cello tape (registered trademark) to examine the number of 1 mm square coating films remaining. The display shows the number of residual coatings in the numerator and the number of 1 mm square coating films first cross-cut in the denominator.

<Evaluation method of ink storage stability>
The aqueous ink was put in a screw tube and stored at 70 ° C. for 1 week, and the viscosity change rate (%) was calculated from the following equation using the initial viscosity and the viscosity after storage. The smaller the rate of change in viscosity, the less the ink thickens and aggregates.
Viscosity change rate (%) = (viscosity after storage−initial viscosity) ÷ initial viscosity × 100
The viscosity of the water-based ink was measured using a TVE-25 viscometer viscometer manufactured by Toki Sangyo Co., Ltd. at a liquid temperature of 25 ° C. and a rotation speed of 20 rpm.

  The composite particle aqueous dispersion of the present invention comprises an aqueous coating composition, an aqueous adhesive composition, an aqueous fiber processing agent composition (a binder composition for pigment printing, a binder composition for nonwoven fabric, a sizing agent composition for reinforcing fibers, Binder composition for antibacterial agent and raw material composition for artificial leather / synthetic leather, etc.), aqueous coating composition (waterproof coating composition, water repellent coating composition, antifouling coating composition, etc.), aqueous paper treatment composition, and It can be suitably used for an aqueous ink composition (inkjet ink or the like).

Claims (7)

  The composite particles (c) in which the polyurethane resin particles (b) are aggregated on the surface of the pigment particles (a1) or the particles (a2) formed by adsorbing the dispersant (d) on the pigment particles (a1) and the aqueous medium. A composite particle aqueous dispersion containing, wherein the ratio of the volume average particle diameter of the pigment particles (a1) to the volume average particle diameter of the polyurethane resin particles (b) [volume average particle diameter of (a1) / (b) The volume average particle diameter of the composite particle aqueous dispersion (X) is 1.5 to 7.   The composite particle aqueous dispersion according to claim 1, wherein the pigment particle (a1) has a volume average particle diameter of 30 to 180 nm, and the polyurethane resin particle (b) has a volume average particle diameter of 20 to 120 nm.   The composite particle aqueous dispersion according to claim 1 or 2, wherein the composite particles (c) have a volume average particle diameter of 70 to 200 nm.   The composite particle (c) is a composite particle obtained by aggregating polyurethane resin particles (b) on the surface of the pigment particle (a1), and the dispersant (d) is not adsorbed on the pigment particle (a1). The composite particle aqueous dispersion according to any one of claims 1 to 3, which is a self-dispersing pigment particle.   5. The composite particle according to claim 1, wherein a weight ratio of the polyurethane resin particles (b) to the pigment particles (a1) [weight of (b) / weight of (a1)] is 1.5 to 5. 5. Aqueous dispersion.   An aqueous ink (Y) containing the composite particle aqueous dispersion (X) according to any one of claims 1 to 5.   The composite particles (c) in which the polyurethane resin particles (b) are aggregated on the surface of the pigment particles (a1) or the particles (a2) formed by adsorbing the dispersant (d) on the pigment particles (a1) and the aqueous medium. A method for producing an aqueous composite particle dispersion comprising the aqueous dispersion (B) containing the polyurethane resin particles (b) and the aqueous dispersion (B1) containing the pigment particles (a1) or the particles (a2) ( A) is a step of adding the aqueous dispersion (B) under stirring, and the ratio of the volume average particle diameter of the pigment particles (a1) to the volume average particle diameter of the polyurethane resin particles (b) [(a1 ) Volume average particle diameter / (b) volume average particle diameter] is 1.5 to 7, and the absolute difference between the zeta potential of the pigment particles (a1) and the zeta potential of the polyurethane resin particles (b) Value and zeta potential of the particle (a2) Method for producing an absolute value of the composite particle aqueous dispersion all at 30~100mV of the difference between the zeta potentials of the serial polyurethane resin particles (b) (X).