JP5118330B2 - Water-based ink for inkjet recording - Google Patents

Description

  The present invention relates to a water-based ink for inkjet recording, and an aqueous dispersion used for the ink.

The ink jet recording system is a recording system in which characters and images are obtained by ejecting ink droplets directly from a very fine nozzle and attaching them to a recording member. This method is widely spread because it is easy to make full color and is inexpensive, and has many advantages such as the ability to use plain paper as a recording member and non-contact with the object to be printed.
Among them, those using pigment-based inks have become mainstream from the viewpoint of weather resistance and water resistance of printed matter. (For example, see Patent Documents 1 to 5)

Patent Document 1 discloses a water-based ink in which a pigment is contained in a vinyl polymer.
Patent Document 2 discloses an ink containing 10 to 1000 ppm of phthalic acid diester and latex in order to form a glossy image. However, the content of phthalic acid diester is small and sufficient functions are exhibited. It has not been.
Patent Document 3 discloses an aqueous pigment dispersion in which a pigment is dispersed with a carboxy group-containing thermoplastic resin, the aqueous pigment dispersion having a carboxy group-containing thermoplastic resin crosslinked after the pigment is dispersed, It is said to be excellent in light resistance, water resistance, solvent resistance, stability over time, and the like.
Patent Document 4 discloses a method for producing an aqueous pigment dispersion in which a pigment and a resin having a carboxy group and a crosslinkable functional group are used, and the crosslinkable functional group of the resin is reacted with a crosslinker to crosslink. The obtained aqueous pigment dispersion has good storage stability, and can form a coating film excellent in water resistance, durability and the like.
Patent Document 5 discloses an ink composed of an aqueous emulsion of core-shell type particles having a core composed of a colorant and a resin component and a shell composed of a resin having a three-dimensional cross-linking structure, and preserves recorded images. It is said that the erasability is excellent.
However, the water-based ink containing the above pigment dispersion is not satisfactory in terms of glossiness and image clarity.

International Publication No. 00/39226 Pamphlet JP 2003-183554 A International Publication No. 99/52966 Pamphlet Japanese Patent Laid-Open No. 9-104834 Japanese Patent Laid-Open No. 2002-12802

  An object of the present invention is to provide an aqueous ink excellent in glossiness and image clarity, and an aqueous dispersion for inkjet recording used in the ink.

The present invention provides the following (1) and (2).
(1) An aqueous dispersion of water-insoluble crosslinked polymer particles containing carbon black, wherein the carbon black has a DBP oil absorption of 40 to 90 ml / 100 g, and the water-insoluble crosslinked polymer particles have an average particle size of 95 nm or less An aqueous dispersion for inkjet recording.
(2) A water-based ink for ink jet recording containing the water dispersion of (1).

  The aqueous dispersion for ink jet recording of the present invention and the aqueous ink containing the aqueous dispersion can give a black printed matter excellent in glossiness and image clarity when printed on dedicated paper.

The aqueous dispersion for inkjet recording of the present invention is an aqueous dispersion of water-insoluble crosslinked polymer particles containing carbon black, and the carbon black has a DBP oil absorption of 40 to 90 ml / 100 g, and the water-insoluble crosslinked polymer particles The average particle size of is not more than 95 nm.
Each component will be described below, but the water-insoluble crosslinked polymer particles containing carbon black having a DBP oil absorption of 40 to 90 ml / 100 g may be simply referred to as “crosslinked polymer particles”. May be simply referred to as “crosslinked polymer”.

(Carbon black (hereinafter also referred to as “CB”))
In the present invention, carbon black having a DBP oil absorption of 40 to 90 ml / 100 g is contained in the water-insoluble crosslinked polymer particles from the viewpoint of glossiness and image clarity.
The DBP (dibutyl phthalate) oil absorption amount of CB is preferably 40 to 85 ml / 100 g, more preferably 40 to 75 ml / 100 g, particularly preferably 45 to 70 ml / 100 g, and most preferably 45 from the viewpoints of glossiness and image clarity. ~ 65ml / 100g.
The volatile content of the carbon black used in the present invention is preferably 3% or less, more preferably 2% or less, from the viewpoint of printing density, glossiness, and image clarity.
The relationship between the amount of the water-insoluble crosslinked polymer and the amount ratio of CB is such that the weight ratio of [CB / water-insoluble crosslinked polymer] is preferably 50/50 to 90/10 from the viewpoint of printing density, glossiness and image clarity. More preferably, it is 55 / 45-80 / 20, More preferably, it is 60 / 40-78 / 22.
In the measurement of the above characteristics, the DBP oil absorption is a value based on ASTM D2414-65T, and the volatile content is the remaining amount after heating at 950 ° C. for 7 minutes (according to ASTM D1620-60).

Examples of the carbon black include furnace black (including high color furnace black and medium color furnace black), thermal lamp black, acetylene black, channel black and the like. Carbon black can also be oxidized by a gas phase or liquid phase oxidation method using an oxidizing agent such as ozone, nitric acid, hydrogen peroxide, nitrogen oxide, or a surface modification method such as plasma treatment.
Specific examples of commercially available carbon black include MONARCH 800 (DBP oil absorption 68, volatile content 1.5%), 1100 (DBP oil absorption 65, volatile content 2.0%), REGAL 330R (manufactured by Cabot Corporation) DBP oil absorption 71, volatile content 1.0%), 415R (DBP oil absorption 71, volatile content 1.0%), MOGUL L (DBP oil absorption 60, volatile content 4.5%), Denexa Printex 35 (DBP oil absorption 42, volatile content 0.5%), 55 (DBP oil absorption 46, volatile content 1.2%), 75 (DBP oil absorption 49, volatile content 1.2%), 85 (DBP Oil absorption 48, volatile content 1.2%), Mitsubishi Chemical Corporation # 900 (DBP oil absorption 56, volatile content 1.5%), # 1000 (DBP oil absorption 56, volatile content 3.0%) # 2600 (DBP absorption Oil amount 77, volatile matter 1.8%), # 45L (DBP oil absorption 45, volatile matter 1.1%), MCF88 (DBP oil absorption 55, volatile matter 1.5%) and the like. The unit of the DBP oil absorption is ml / 100 g.

(Water-insoluble polymer)
The water-insoluble polymer used in the present invention is crosslinked with a crosslinking agent to form a crosslinked polymer. Here, the water-insoluble polymer means that when the polymer is dried at 105 ° C. for 2 hours and then dissolved in 100 g of water at 25 ° C., the dissolution amount is 10 g or less, preferably 5 g or less, more preferably 1 g or less. Is a polymer. When the polymer has a salt-forming group, the dissolution amount is a dissolution amount when the salt-forming group of the polymer is neutralized 100% with acetic acid or sodium hydroxide depending on the type.
Examples of the polymer to be used include polyester, polyurethane, and vinyl polymer. From the viewpoint of dispersion stability, a vinyl polymer obtained by addition polymerization of a vinyl monomer (vinyl compound, vinylidene compound, vinylene compound) is preferable.

(Vinyl polymer)
As the vinyl polymer, (a) a salt-forming group-containing monomer (hereinafter sometimes referred to as “(a) component”), (b) a macromer (hereinafter sometimes referred to as “(b) component”) and / or (c ) A water-insoluble vinyl polymer obtained by copolymerizing a monomer mixture (hereinafter also referred to as “monomer mixture”) containing a hydrophobic monomer (hereinafter also referred to as “component (c)”) is preferable. This water-insoluble vinyl polymer has a structural unit derived from the component (a), a structural unit derived from the component (b) and / or a structural unit derived from the component (c). A more preferred water-insoluble vinyl polymer has a structural unit derived from the component (a) or a structural unit derived from the components (a) and (c) as a main chain, and a structural unit derived from the component (b) as a side chain. It is a water-insoluble graft polymer.

(A) The salt-forming group-containing monomer is used from the viewpoint of enhancing the dispersion stability of the resulting dispersion. Examples of the salt-forming group include an anionic group such as a carboxy group, a sulfonic acid group, and a phosphoric acid group, and a cationic group such as an amino group and an ammonium group.
Examples of the salt-forming group-containing monomer include cationic monomers and anionic monomers described in JP-A-9-286939, paragraph [0022].
Representative examples of the cationic monomer include unsaturated amine-containing monomers and unsaturated ammonium salt-containing monomers. Among these, N, N-dimethylaminoethyl (meth) acrylate, N- (N ′, N′-dimethylaminopropyl) (meth) acrylamide and vinylpyrrolidone are preferable.
Representative examples of anionic monomers include unsaturated carboxylic acid monomers, unsaturated sulfonic acid monomers, unsaturated phosphoric acid monomers, and the like.
Examples of the unsaturated carboxylic acid monomer include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, and 2-methacryloyloxymethyl succinic acid. Examples of the unsaturated sulfonic acid monomer include styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, 3-sulfopropyl (meth) acrylate, bis- (3-sulfopropyl) -itaconic acid ester, and the like. Unsaturated phosphoric acid monomers include vinyl phosphonic acid, vinyl phosphate, bis (methacryloxyethyl) phosphate, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, dibutyl-2-acryloyloxyethyl phosphate Etc.
Among the anionic monomers, unsaturated carboxylic acid monomers are preferable, and acrylic acid and methacrylic acid are more preferable from the viewpoints of dispersion stability and ejection stability.

(B) The macromer is used from the viewpoint of enhancing the dispersion stability of the crosslinked polymer particles. The macromer includes a macromer which is a monomer having a polymerizable unsaturated group having a number average molecular weight of 500 to 100,000, preferably 1,000 to 10,000. In addition, the number average molecular weight of (b) macromer is measured using polystyrene as a standard substance by gel chromatography using chloroform containing 1 mmol / L of dodecyldimethylamine as a solvent.
Among the macromers, a styrene macromer and an aromatic group-containing (meth) acrylate macromer having a polymerizable functional group at one end are preferable from the viewpoint of dispersion stability of the crosslinked polymer particles.
Examples of the styrenic macromer include a styrene monomer homopolymer or a copolymer of a styrene monomer and another monomer. Examples of the styrene monomer include styrene, 2-methylstyrene, vinyl toluene, ethyl vinyl benzene, vinyl naphthalene, chlorostyrene, and the like.

Examples of the aromatic group-containing (meth) acrylate-based macromer include a homopolymer of an aromatic group-containing (meth) acrylate or a copolymer thereof with another monomer. As an aromatic group-containing (meth) acrylate, an arylalkyl having 7 to 22 carbon atoms, preferably 7 to 18 carbon atoms, more preferably 7 to 12 carbon atoms, which may have a substituent containing a hetero atom. (Meth) acrylate having an aryl group having 6 to 22 carbon atoms, preferably 6 to 18 carbon atoms, more preferably 6 to 12 carbon atoms, which may have a group or a substituent containing a hetero atom In addition, examples of the substituent containing a hetero atom include a halogen atom, an ester group, an ether group, and a hydroxy group. Examples include benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, and benzyl (meth) acrylate is particularly preferable.
The polymerizable functional group present at one end of the macromer is preferably an acryloyloxy group or a methacryloyloxy group, and the other monomer to be copolymerized is preferably acrylonitrile.
The content of the styrene monomer in the styrene macromer or the aromatic group-containing (meth) acrylate in the aromatic group-containing (meth) acrylate macromer is preferably 50% by weight from the viewpoint of increasing the affinity with the pigment. Above, more preferably 70% by weight or more.

(B) The macromer may have a side chain composed of another structural unit such as an organopolysiloxane. This side chain can be obtained, for example, by copolymerizing a silicone macromer having a polymerizable functional group at one end represented by the following formula (11).
_{CH 2 = C (CH 3)} -COOC 3 H 6 - [Si (CH _{3) 2} O] _{t -Si (CH 3) 3 (} 11)
(In the formula, t represents a number of 8 to 40).
Examples of commercially available styrenic macromers as component (b) include Toa Gosei Co., Ltd. trade names, AS-6 (S), AN-6 (S), HS-6 (S), and the like. It is done.

(C) The hydrophobic monomer is used from the viewpoint of improving the printing density. Examples of the hydrophobic monomer include alkyl (meth) acrylates and aromatic group-containing monomers.
As the alkyl (meth) acrylate, those having an alkyl group having 1 to 22 carbon atoms, preferably 6 to 18 carbon atoms are preferable. For example, methyl (meth) acrylate, ethyl (meth) acrylate, (iso) propyl (meta) ) Acrylate, (iso or tertiary) butyl (meth) acrylate, (iso) amyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (iso) octyl (meth) acrylate, (iso) Examples include decyl (meth) acrylate, (iso) dodecyl (meth) acrylate, and (iso) stearyl (meth) acrylate.
In the present specification, “(iso or tertiary)” and “(iso)” mean both the case where these groups are present and the case where these groups are not present. Indicates. “(Meth) acrylate” indicates acrylate, methacrylate, or both.

The aromatic group-containing monomer has an aromatic group having 6 to 22 carbon atoms, preferably 6 to 18 carbon atoms, more preferably 6 to 12 carbon atoms, which may have a substituent containing a hetero atom. Vinyl monomers are preferable, and examples thereof include the styrene monomer (c-1 component) and the aromatic group-containing (meth) acrylate (c-2 component). The above-mentioned thing is mentioned as a substituent containing a hetero atom.
Among the components (c), a styrene monomer (c-1 component) is preferable from the viewpoint of improving printing density, and styrene and 2-methylstyrene are particularly preferable as the styrene monomer. The content of the component (c-1) in the component (c) is preferably 10 to 100% by weight, more preferably 20 to 80% by weight, from the viewpoint of improving printing density.
Moreover, as an aromatic group containing (meth) acrylate (c-2) component, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, etc. are preferable. The content of the component (c-2) in the component (c) is preferably 10 to 100% by weight, more preferably 20 to 80% by weight, from the viewpoint of improving printing density and gloss. Moreover, it is also preferable to use (c-1) component and (c-2) component together.

The monomer mixture may further contain (d) a hydroxyl group-containing monomer (hereinafter sometimes referred to as “component (d)”). (D) The hydroxyl group-containing monomer exhibits an excellent effect of enhancing dispersion stability.
As the component (d), for example, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, polyethylene glycol (n = 2 to 30, n represents the average number of added moles of oxyalkylene group. The same)) (meth) acrylate, polypropylene glycol (n = 2-30) (meth) acrylate, poly (ethylene glycol (n = 1-15) / propylene glycol (n = 1-15)) (meth) acrylate, etc. Can be mentioned. Among these, 2-hydroxyethyl (meth) acrylate, polyethylene glycol monomethacrylate, and polypropylene glycol methacrylate are preferable.

The monomer mixture may further contain (e) a monomer represented by the following formula (12) (hereinafter sometimes referred to as “(e) component”).
^{_{CH 2 = C (R 7)}} COO (R 8 O) q R 9 (12)
Wherein R ⁷ is a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms, R ⁸ is a divalent hydrocarbon group having 1 to 30 carbon atoms which may have a hetero atom, and R ⁹ is , A monovalent hydrocarbon group having 1 to 30 carbon atoms which may have a hetero atom, or a phenyl group optionally having an alkyl group having 1 to 9 carbon atoms, q is an average added mole number Meaning 1 to 60, preferably 1 to 30)
(E) component expresses the outstanding effect of improving discharge property.
In the formula (12), examples of the hetero atom include a nitrogen atom, an oxygen atom, a halogen atom, and a sulfur atom.
Preferable examples of R ⁷ include a methyl group, an ethyl group, and an (iso) propyl group.
Preferred examples of the R ⁸ O group include oxyethylene group, oxytrimethylene grave, oxypropane-1,2-diyl group, oxytetramethylene group, oxyheptamethylene group, oxyhexamethylene group, and two or more kinds thereof. Examples thereof include oxyalkanediyl groups having 2 to 7 carbon atoms (oxyalkylene groups).
Preferable examples of R ⁹ include aliphatic alkyl groups having 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms, alkyl groups having 7 to 30 carbon atoms having an aromatic ring, and 4 to 30 carbon atoms having a heterocyclic ring. And a phenyl group which may have an alkyl group having 1 to 3 carbon atoms.

  Specific examples of the component (e) include methoxypolyethylene glycol (1 to 30: the value of q in the formula (12). The same applies hereinafter) (meth) acrylate, methoxypolytetramethylene glycol (1 to 30) ( (Meth) acrylate, ethoxy polyethylene glycol (1-30) (meth) acrylate, octoxy polyethylene glycol (1-30) (meth) acrylate, polyethylene glycol (1-30) (meth) acrylate 2-ethylhexyl ether, (iso) Propoxy polyethylene glycol (1-30) (meth) acrylate, butoxy polyethylene glycol (1-30) (meth) acrylate, methoxypolypropylene glycol (1-30) (meth) acrylate, methoxy (ethylene glycol / propylene glycol) Copolymerization) (1-30, ethylene glycol therein: 1-29) (meth) acrylate. Among these, octoxypolyethylene glycol (1-30) (meth) acrylate and polyethylene glycol (1-30) (meth) acrylate 2-ethylhexyl ether are preferable.

Specific examples of commercially available (d) and (e) components include Shin-Nakamura Chemical Co., Ltd. polyfunctional acrylate monomer (NK ester) M-40G, 90G, 230G, and Nippon Oil & Fats Co., Ltd. BLEMMER series, PE-90, 200, 350, PME-100, 200, 400, 1000, PP-500, 800, 1000, AP-150, 400, 550, 800 , 50PEP-300, 50POEP-800B, and the like.
The components (a) to (e) can be used alone or in admixture of two or more.

The content of the components (a) to (e) in the monomer mixture (content as an unneutralized amount; the same applies hereinafter) or the water-insoluble vinyl polymer (a) to (e) ) The content of the structural unit derived from the component is as follows.
The content of component (a) is preferably 2 to 40% by weight, more preferably 2 to 30% by weight, and particularly preferably 3 to 20% by weight from the viewpoint of dispersion stability of the resulting dispersion.
The content of the component (b) is preferably 1 to 25% by weight, more preferably 5 to 20% by weight, particularly from the viewpoint of enhancing the interaction with CB.
The content of the component (c) is preferably 5 to 98% by weight, more preferably 10 to 60% by weight, from the viewpoint of improving print density.
The content of component (d) is preferably 5 to 40% by weight, more preferably 7 to 20% by weight, from the viewpoint of dispersion stability of the resulting dispersion.
The content of the component (e) is preferably 5 to 50% by weight, more preferably 10 to 40% by weight, from the viewpoint of improving dischargeability.
The total content of [component (a) + component (d)] in the monomer mixture is preferably 6 to 60% by weight, more preferably 10 to 50% by weight, from the viewpoint of dispersion stability of the resulting dispersion. is there. The total content of [component (a) + component (e)] is preferably 6 to 75% by weight, more preferably 13 to 50% by weight, from the viewpoint of dispersion stability and dischargeability of the resulting dispersion. . Moreover, the total content of [(a) component + (d) component + (e) component] is preferably 6 to 60% by weight, more preferably from the viewpoint of dispersion stability and dischargeability of the resulting dispersion. 7 to 50% by weight.
The weight ratio of [(a) component / [(b) component + (c) component]] is preferably 0.01 to 1, more preferably from the viewpoint of dispersion stability and print density of the resulting dispersion. Is 0.02 to 0.67, more preferably 0.03 to 0.50.

(Production of water-insoluble polymer)
The water-insoluble polymer used in the present invention is produced by copolymerizing a monomer mixture by a known polymerization method such as a bulk polymerization method, a solution polymerization method, a suspension polymerization method or an emulsion polymerization method. Among these polymerization methods, the solution polymerization method is preferable.
The solvent used in the solution polymerization method is not particularly limited, but a polar organic solvent is preferable. When the polar organic solvent is miscible with water, it can be used by mixing with water. Examples of the polar organic solvent include aliphatic alcohols having 1 to 3 carbon atoms such as methanol, ethanol and propanol; ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate and the like. Among these, methanol, ethanol, acetone, methyl ethyl ketone, or a mixed solvent of one or more of these and water is preferable.
In the polymerization, azo compounds such as 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), t-butyl peroxyoctate, dibenzoyl oxide, etc. Known radical polymerization initiators such as organic peroxides can be used.
The amount of the radical polymerization initiator is preferably 0.001 to 5 mol, more preferably 0.01 to 2 mol, per mol of the monomer mixture.
In the polymerization, a known polymerization chain transfer agent such as mercaptans such as octyl mercaptan and 2-mercaptoethanol and thiuram disulfide may be further added.

Since the polymerization conditions of the monomer mixture vary depending on the type of radical polymerization initiator, monomer, and solvent used, it cannot be determined unconditionally. Usually, the polymerization temperature is preferably 30 to 100 ° C, more preferably 50 to 80 ° C, and the polymerization time is preferably 1 to 20 hours. The polymerization atmosphere is preferably a nitrogen gas atmosphere or an inert gas atmosphere such as argon.
After completion of the polymerization reaction, the produced polymer can be isolated from the reaction solution by a known method such as reprecipitation or solvent distillation. Further, the obtained polymer can be purified by repeating reprecipitation or by removing unreacted monomers and the like by membrane separation, chromatographic method, extraction method and the like.

The weight average molecular weight of the water-insoluble polymer used in the present invention is preferably 5,000 to 500,000, more preferably 10,000 to 400,000, and 10,000 to 300,000 from the viewpoints of glossiness and CB dispersion stability. Further preferred is 20,000 to 300,000.
The weight average molecular weight of the water-insoluble polymer is measured using polystyrene as a standard substance by gel chromatography using dimethylformamide containing 60 mmol / L phosphoric acid and 50 mmol / L lithium bromide as a solvent. .

When the water-insoluble vinyl polymer used in the present invention has (a) a salt-forming group derived from a salt-forming group-containing monomer, it is neutralized with a neutralizing agent. As the neutralizing agent, an acid or a base can be used depending on the type of salt or product group in the polymer. For example, hydrochloric acid, acetic acid, propionic acid, phosphoric acid, sulfuric acid, lactic acid, succinic acid, glycolic acid, gluconic acid, glyceric acid and other acids, lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonia, methylamine, dimethylamine , Bases such as trimethylamine, ethylamine, diethylamine, triethylamine, triethanolamine, and tributylamine.
The degree of neutralization of the salt-forming group is preferably 10 to 200%, more preferably 20 to 150%, and particularly preferably 50 to 150%.
Here, the degree of neutralization can be determined by the following formula when the salt-forming group is an anionic group.
{[Weight of neutralizing agent (g) / equivalent of neutralizing agent] / [acid value of polymer (KOH mg / g) × polymer weight (g) / (56 × 1000)]} × 100
When the salt-forming group is a cationic group, it can be determined by the following formula.
{[Weight of neutralizing agent (g) / equivalent of neutralizing agent] / [amine value of polymer (HCL mg / g) × polymer weight (g) / (36.5 × 1000)]} × 100
The acid value and amine value can be calculated from the structural unit of the polymer. Alternatively, it can also be determined by a method in which a polymer is dissolved in an appropriate solvent (for example, methyl ethyl ketone) and titrated.

(Crosslinking agent)
As the crosslinking agent used in the present invention, a crosslinking agent having at least two reactive groups in the molecule (hereinafter simply referred to as “crosslinking agent”) is preferable in order to moderately crosslink the water-insoluble polymer. The molecular weight of the cross-linking agent is preferably 120 to 2000, more preferably 150 to 1500, and particularly preferably 150 to 1000, from the viewpoint of easy reaction and storage stability of the resulting cross-linked polymer particles.
The number of reactive groups is preferably 2 to 4, and more preferably 2 to 3, from the viewpoint of controlling the molecular weight to improve glossiness and image clarity. Preferred examples of the reactive group include one or more selected from the group consisting of a hydroxyl group, an epoxy group, an aldehyde group, an amino group, and a carboxy group.
Specific examples of the crosslinking agent include the following (a) to (e).
(A) Compound having two or more hydroxyl groups in the molecule: for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, glycerin, polyglycerin, propylene glycol, 1,4-butanediol, 1,5-pentane Polyhydric alcohols such as diol, 1,6-hexanediol, neopentyl alcohol, diethanolamine, tridiethanolamine, polypropylene glycol, polyvinyl alcohol, pentaerythritol, sorbitol, sorbitan, glucose, mannitol, mannitan, sucrose, and glucose.
(B) Compounds having two or more epoxy groups in the molecule: for example, polyglycidyl ethers such as ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin triglycidyl ether, and polyglycerol polyglycidyl ether.
(C) Compounds having two or more aldehyde groups in the molecule: for example, polyaldehydes such as glutaraldehyde and glyoxal.
(D) Compounds having two or more amino groups in the molecule: for example, polyamines such as ethylenediamine and polyethyleneimine.
(E) Compounds having two or more carboxy groups in the molecule: for example, polyvalent carboxylic acids such as oxalic acid, malonic acid, succinic acid, fumaric acid, maleic acid and adipic acid.
Among these, (b) a compound having two or more epoxy groups in the molecule is preferable.

The water-insoluble polymer has a reactive group (crosslinkable functional group) capable of reacting with the crosslinking agent, and a suitable combination example of both is as follows.
When the reactive group of the water-insoluble polymer is an acidic group such as a carboxy group, a sulfonic acid group, or a phosphoric acid group, the above-mentioned compounds (a), (b) and (d) are preferred as the crosslinking agent.
When the reactive group of the water-insoluble polymer is an amino group or a hydroxyl group, the crosslinking agent is preferably the compounds (b), (c) and (e).
When the reactive group of the water-insoluble polymer is an isocyanate group or an epoxy group, the crosslinking agent is preferably the compounds (a), (d) and (e).
Among the above combinations, one type selected from an acidic group (carboxy group, sulfonic acid group, phosphoric acid group, etc.), amino group and hydroxyl group from the viewpoint of controlling the water-insoluble polymer so as to impart an appropriate crosslinking structure. A combination of the above water-insoluble polymer having a reactive group and (b) a compound having two or more epoxy groups in the molecule is particularly preferred.

A water-insoluble polymer having an acidic group such as a carboxy group, a sulfonic acid group, and a phosphoric acid group, an amino group, a hydroxyl group, an isocyanate group, and an epoxy group as a reactive group (crosslinkable functional group) that can react with the crosslinking agent is In the production of the above water-insoluble polymer, it can be produced by copolymerizing a polymerizable monomer composition containing a monomer having the reactive group.
As the polymer having a reactive group capable of reacting with the crosslinking agent, the polymer having a salt-forming group such as an acidic group or an amino group can be a polymer obtained by copolymerizing the aforementioned salt-forming group-containing monomer. As the polymer having, a polymer obtained by copolymerizing the above-mentioned hydroxyl group-containing monomer can be used.
As the polymer having an epoxy group, a monomer having an epoxy group, specifically, a polymer obtained by copolymerizing glycidyl (meth) acrylate can be used. As the polymer having an isocyanate group, (i) a monomer having an isocyanate group, for example, a polymer copolymerized with isocyanate ethyl (meth) acrylate, (ii) an isocyanate-terminated prepolymer obtained from an unsaturated polyester polyol and isocyanate was copolymerized. A polymer or the like can be used.

(Water-insoluble organic compound)
The water-insoluble organic compound used in the present invention is considered to be at least partially contained in the crosslinked polymer particles to improve its flexibility. By improving the flexibility of the crosslinked polymer particles by the water-insoluble organic compound, the fusing property between the polymer particles discharged from the nozzle of the ink jet recording apparatus is increased, and the polymer particles are uniformly diffused on the recording paper, It is considered that the glossiness and image clarity of the printed matter are improved by the smooth printing surface.

The water-insoluble organic compound preferably has a molecular weight of 100 to 2,000, more preferably a molecular weight of 100 to 1,500, from the viewpoint of improving the glossiness and image clarity of the water-based ink.
The amount of the water-insoluble organic compound dissolved in 100 g of water (20 ° C.) is preferably 5 g or less, more preferably 3 g or less, still more preferably 1 g or less, and particularly preferably 0.5 g or less.
The water-insoluble organic compound preferably has a LogP value of 4 from the viewpoint of improving the glossiness of printed matter when printed on special paper and improving the storage stability of an aqueous dispersion containing the water-insoluble organic compound. -18, more preferably 5-16, particularly preferably 6-15. Moreover, SP value becomes like this. Preferably it is 8.5-13, More preferably, it is 9-12.

Here, “Log P value” means the logarithmic value of the 1-octanol / water partition coefficient of water-insoluble organic compounds, calculated by the fragment approach by SRC's LOGKOW / KOWWIN Program of KowWin (Syracuse Research Corporation, USA). The KowWin Program methodology is described in the following journal article: Meylan, WM and PH Howard. 1995. Atom / fragment contribution method for using octanol-water partition coefficients. J. Pharm. Sci. 84: 83-92 .). The fragment approach is based on the chemical structure of the compound and takes into account the number of atoms and the type of chemical bond. The LogP value is a numerical value generally used for relative evaluation of the hydrophilicity / hydrophobicity of an organic compound.
The SP value (solubility parameter) is represented by the square root of the ratio between the cohesive energy density and the molecular volume, as shown by the following formula.
SP value ((J / m ³ ) ^1/2 ) = (ΔE / ΔV) ^1/2
Here, ΔE represents the cohesive energy density, and ΔV represents the molecular volume. The value can be calculated by the method of Fedors [Robert F. Fedors, Polymer Engineering and Science, 14, 147-154 (1974)].

The water-insoluble organic compound is preferably an ester compound, an ether compound, or a sulfonic acid amide compound so that the water-insoluble organic compound is easily contained in the crosslinked polymer particles, and the ester or ether having two or more ester or ether bonds in the molecule. Compound (f) and / or one or more selected from the group consisting of one or more ester or ether bonds and a carboxy group, a sulfonic acid group, a phosphoric acid residue, a carbonyl group, an epoxy group and a hydroxyl group in the molecule An ester or ether compound (g) having one or more of the above functional groups is more preferred. The number of ester or ether bonds in the compound (f) is preferably 2-5. The ester or ether bond of the compound (g) is preferably 1 to 5. The number of functional groups is preferably 1 to 3. In addition, a phosphoric acid residue means the remaining phosphoric acid group in which a part of phosphoric acid was esterified or etherified.
Among the ester compounds, esters obtained from monovalent carboxylic acids or salts thereof and polyhydric alcohols, polyacids (polycarboxylic acids, phosphoric acids) or esters obtained from salts thereof and monohydric alcohols are preferred, and ether compounds Of these, polyhydric alcohol ethers are preferred. Examples of the salt include alkali metal salts, alkanolamine salts, ammonium salts and the like.

As the monovalent carboxylic acid, a linear or branched aliphatic carboxylic acid having 1 to 18 carbon atoms, preferably 2 to 10 carbon atoms (for example, acetic acid, butyric acid, caproic acid, caprylic acid, capric acid, lauric acid, Linear aliphatic carboxylic acids such as palmitic acid, branched aliphatic carboxylic acids such as pivalic acid, unsaturated aliphatic carboxylic acids such as acrylic acid and methacrylic acid), and aromatic carboxylic acids having 6 to 12 carbon atoms (for example, benzoic acid) Acid) and the like.
Examples of the polyvalent acid include aliphatic carboxylic acids having 2 to 12 carbon atoms such as maleic acid, fumaric acid, itaconic acid, succinic acid, adipic acid and sebacic acid, and 6 to 12 carbon atoms such as phthalic acid and trimellitic acid. Aromatic carboxylic acid, phosphoric acid and the like can be mentioned.
The monohydric alcohol is a linear or branched aliphatic alcohol having 1 to 18 carbon atoms, preferably 2 to 10 carbon atoms (for example, ethyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol, decyl alcohol, dodecyl alcohol). , Aromatic alcohols having 6 to 12 carbon atoms (for example, phenol) and alkylene oxide compounds thereof.
Examples of the polyhydric alcohol include polyhydric alcohols having 2 to 12 carbon atoms such as ethylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, pentaerythritol, and glycerin, and alkylene oxide compounds thereof. A saturated or unsaturated fatty acid or alcohol can be used.

Specific examples of the water-insoluble organic compound include (1) aliphatic carboxylic acid ester, (2) aromatic carboxylic acid ester, (3) cycloalkane (ken) carboxylic acid ester, (4) phosphoric acid ester, (5) Oxy acid ester, (6) glycol ester, (7) epoxy ester, (8) sulfonamide, (9) polyester, (10) glyceryl alkyl ether, (11) glyceryl alkyl ester, (12) glycol alkyl ether, etc. Can be mentioned.
Among these, from the viewpoint of improving glossiness and image clarity, the compounds of the above (1) to (5), (8) and (10) are preferable, (1) aliphatic carboxylic acid ester, (2) aromatic More preferably, it is at least one selected from the group consisting of carboxylic acid esters, (3) cycloalkane (ken) carboxylic acid esters, and (4) phosphoric acid esters, aliphatic dicarboxylic acid esters, aromatic di- or tricarboxylic acids. It is particularly preferable that it is one or more selected from the group consisting of esters, cycloalkane (ken) dicarboxylic acid esters and phosphoric acid di- or triesters.

  (1) Aliphatic carboxylic acid ester, (2) aromatic carboxylic acid ester, and (3) cycloalkane (ken) carboxylic acid ester are preferably compounds represented by the following formula (1).

(.R wherein, R ¹ and R ² are each independently a hydrogen atom, or a hydrocarbon group having 1 to 22 carbon atoms, R ³ is showing a divalent hydrocarbon group having 1 to 18 carbon atoms ¹ and R ² may be the same or different, except for the case where R ¹ and R ² are both hydrogen atoms, R ^{1 to} R ³ may have a substituent, and n is independent. Represents an average addition mole number of 0 to 30, and AO represents an alkanediyloxy group.)

R ¹ and R ² are preferably a linear or branched alkyl or alkenyl group having 2 to 18 carbon atoms, more preferably 4 to 12 carbon atoms, from the viewpoint of improving glossiness and image clarity of printed matter. An aralkyl group having 7 to 23 carbon atoms, preferably 7 to 11 carbon atoms, or an aryl group having 6 to 22 carbon atoms, preferably 6 to 10 carbon atoms, specifically, a methyl group, an ethyl group, or a propyl group. Isopropyl group, butyl group, hexyl group, 2-ethylhexyl group, octyl group, dodecyl group, cetyl group, phenyl group, benzyl group and the like. The same applies to the following equations.
R ³ is preferably a divalent aliphatic hydrocarbon group, a cyclic hydrocarbon group or an aromatic hydrocarbon group, preferably 2 to 15 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 carbon atoms. An alkanediyl group (alkylene group) or an alkenylene group having 8 to 8 carbon atoms, an arylene group having 6 to 10 carbon atoms, more preferably a phenylene group, or a cyclic saturated or unsaturated hydrocarbon group having 3 to 8 carbon atoms. Specifically, ethylene group, trimethylene group, propane-1,2-diyl group, tetramethylene group, heptamethylene group, hexamethylene group, pentane-1,5-diyl group, octamethylene group, dodecamethylene group, phenylene Groups and the like. The same applies to the following equations.
n is independently preferably 0 to 20, more preferably 0 to 15, still more preferably 1 to 15, particularly preferably 2 to 14, and most preferably 2 to 12.

AO is the number of carbon atoms such as ethyleneoxy group (EO), propyleneoxy group (trimethyleneoxy group or propane-1,2-diyloxy group) (PO), butyleneoxy group (tetramethyleneoxy group etc.) (BO), etc. 2 to 4 alkanediyloxy groups (alkyleneoxy groups), and when n is 2 or more, AO may be the same or different, and when they are different, AO may be added in blocks or randomly. Also good.
Examples of the substituent that R ^{1 to} R ³ may have include halogen atoms such as fluorine, chlorine and bromine atoms, alkoxy groups having 1 to 12 carbon atoms such as methoxy, ethoxy and isopropoxy groups, phenyloxy Aryloxy groups such as oxycarbonyl groups such as methoxycarbonyl groups, acyl groups such as acetyl and benzoyl groups, acyloxy groups such as acetyloxy groups, cyano groups, nitro groups, hydroxyl groups, carboxy groups, oxo groups, epoxy groups , Ether groups, ester groups and the like (these are collectively referred to as “substituents”). These substituents may be one or a combination of two or more.
The substituent that R ³ may have is preferably —CO (O) — (AO) n—R ¹ . In the formula, AO is the same as described above. n has the same meaning as n described above, and the preferred range is also the same. R ¹ has the same meaning as R ¹ described above, and the preferred range is also the same. In this case, R ³ is preferably an aromatic hydrocarbon group.

(1) The aliphatic carboxylic acid ester is more specifically a compound in which, in the formula (1), R ³ is a divalent aliphatic hydrocarbon group which may have a substituent. preferable. Examples of this substituent include the above-described substituents.
Specific examples of the aliphatic carboxylic acid ester include dimethyl adipate, diethyl adipate, dibutyl adipate, diisobutyl adipate, bis (2-ethylhexyl) adipate, diisononyl adipate, diisodecyl adipate, bis (butyldiethylene glycol) adipate, dimethyl sebacate, diethyl sebacate Examples thereof include aliphatic dibasic acid esters such as keto, dibutyl sebacate, bis (2-ethylhexyl) sebacate, diethyl succinate and bis (2-ethylhexyl) azelate. Among these, diethyl adipate, dibutyl adipate, diisobutyl adipate, bis (butyldiethylene glycol) adipate, bis (octoxypolyethylene glycol) adipate (R ¹ and R ² are both 2-ethylhexyl, EO average addition moles m and n = 1 to 4), bis (octoxypolypropylene glycol) adipate (R ¹ and R ² are both 2-ethylhexyl, average added moles of PO and n = 1 to 6), bis (octoxypolyethyleneglycol / polypropylene) Propylene glycol) adipate (R ¹ and R ² are both 2-ethylhexyl, EO and PO total average addition moles m and n = 4-12, block addition), bis [octoxypoly (ethylene glycol propylene glycol)] adipate (R ¹ and R ² are both 2 -Ethyl hexyl, EO and PO total average addition moles m and n = 4-12, random addition), diethyl sebacate, dibutyl sebacate, diisobutyl sebacate, etc. Diesters are particularly preferred.

  (2) The aromatic carboxylic acid ester is more preferably a compound represented by the following formulas (2-1) and (2-2).

(In the formula, R ¹ and R ² have the same meaning as described above and may be the same or different. AO and n have the same meaning as described above and may be the same or different.)
Specific examples of the aromatic carboxylate include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, bis (2-ethylhexyl) phthalate, di-n-octyl phthalate, diisodecyl phthalate, butyl benzyl phthalate, octyl benzyl phthalate, nonyl Phthalate esters such as benzyl phthalate, stearyl benzyl phthalate, octyl decyl phthalate, dicyclohexyl phthalate, diphenyl phthalate, bis (dimethylcyclohexyl) phthalate, bis (t-butylcyclohexyl) phthalate, ethyl phthalyl ethyl glycolate, tributyl trimellitate, Trimellitic acid esters such as triisobutyl trimellitate and tri (2-ethylhexyl) trimellitate It is below. Among these, carbon number 3 such as phthalic acid diester having an aliphatic alcohol residue having 1 to 5 carbon atoms such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, octyl benzyl phthalate, nonyl benzyl phthalate, stearyl benzyl phthalate Benzyl phthalate having -18 alkyl groups, bis (octoxypolyethylene glycol) phthalate (R ¹ and R ² are both 2-ethylhexyl, average addition number m of EO and n = 1-5), bis (octoxy Polypropylene glycol) phthalate (R ¹ and R ² are both 2-ethylhexyl, average added moles m and n of PO = 1 to 4), bis (octoxypolyethylene glycol / polypropylene glycol) phthalate (R ¹ and R ² Are both 2-Echi Hexyl, each total average addition mole number m and n = 4 to 12 of EO and PO, block addition), bis [Okutokishipori (ethylene glycol-propylene glycol) phthalate (R ¹ and R ² are both 2-ethylhexyl, EO and Each total average addition mole number of PO and n = 4 to 12, random addition), and trimellitic acid diester having an aliphatic alcohol residue of 3 to 5 carbon atoms such as tributyl trimellitate and triisobutyl trimellitate Is particularly preferred.

(3) The cycloalkane (ken) carboxylic acid ester is more preferably a cyclohexane (cene) carboxylic acid ester represented by the following formulas (3-1) and (3-2). Examples of the cycloalkane (ken) group include a cyclic hydrocarbon group which may have one unsaturated group having 3 to 8 carbon atoms.

(In the formula, R ¹ and R ² have the same meaning as described above and may be the same or different. AO and n have the same meaning as described above and may be the same or different.)
Specific examples of the cycloalkane (ken) carboxylic acid ester include cyclohexane esters such as 1,2-cyclohexanedicarboxylic acid dibutyl ester and 1,2-cyclohexanedicarboxylic acid diisononyl ester, 3,4-cyclohexene dicarboxylic acid dibutyl ester, 3 Cyclohexene esters such as 1,4-cyclohexenecarboxylic acid diisononyl ester.
(4) The phosphate ester is preferably a compound represented by the following formula (4).

(In the formula, R ¹ and R ² have the same meaning as described above and may be the same or different.)
Specific examples of phosphate esters include tributyl phosphate, tris (2-ethylhexyl) phosphate, tris (butoxyethyl) phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, 2-ethylhexyl diphenyl A phosphate etc. are mentioned. Among these, phosphate esters having a C5-C9 alkoxyalkyl group such as tris (butoxyethyl) phosphate, phosphate esters having a C4-12 aliphatic hydrocarbon group such as tributyl phosphate, tris ( Butoxyethyl) phosphates, tricresyl phosphates, trixylenyl phosphates, cresyl diphenyl phosphates, and other phosphate esters having an aromatic hydrocarbon group of 7 to 12 carbon atoms are particularly preferred. The phosphoric acid ester is preferably a phosphoric acid di- or triester.

  (5) The oxyacid ester is preferably a compound represented by the following formula (5).

(In the formula, R ¹ , R ² and R ³ have the same meaning as described above. R ¹ and R ² may be the same or different.)
Specific examples of the oxyester include triethyl acetylcitrate, tributyl acetylcitrate, methyl acetylricinoleate and the like.

  (6) The glycol ester is preferably a compound represented by the following formula (6).

(In the formula, R ¹ , R ² and R ³ have the same meaning as described above. R ¹ and R ² may be the same or different.)
Specific examples of the glycol ester include diethylene glycol dibenzoate and triethylene glycol di (2-ethylhexoate).

  (7) The epoxy ester is preferably a compound represented by the following formula (7).

(In the formula, R ¹ has the same meaning as described above. R ⁴ and R ⁵ each independently represents a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms, and R ⁶ represents an alkanediyloxy group having 1 to ⁶ carbon atoms. Show.)
Specific examples of the epoxy ester include butyl epoxy stearate and octyl epoxy stearate.

  (8) The sulfonamide is preferably a compound represented by the following formula (8).

(In the formula, R ¹ and R ² have the same meaning as described above and may be the same or different.)
Specific examples of the sulfonamide include o- and p-toluenesulfonamide, N-butylbenzenesulfonamide and the like.

  (9) The polyester is preferably a compound represented by the following formula (9).

(In the formula, R ¹ , R ² and R ³ have the same meaning as described above and may be the same or different. P represents a number of 1 to 18, preferably 1 to 10.)
Specific examples of the polyester include poly (1,2-butanediol adipate), poly (1,3-butanediol adipate) and the like.
(10) Specific examples of the glyceryl alkyl ether include glyceryl monoether, glyceryl diether, and glyceryl triether. In these, the glyceryl monoether which has a C8-C30 linear or branched alkyl group is preferable. The alkyl group has 8 to 30 carbon atoms, preferably 8 to 22 carbon atoms, and more preferably 8 to 14 carbon atoms.
Examples of the alkyl group include 2-ethylhexyl, (iso) octyl, (iso) decyl, (iso) dodecyl, (iso) myristyl, (iso) cetyl, (iso) stearyl, and (iso) behenyl groups.
There is no restriction | limiting in particular about the position of an alkyl group, Either 1-alkyl glyceryl monoether and 2-alkyl glyceryl monoether may be sufficient.

(11) Specific examples of the glyceryl alkyl ester include glyceryl monoalkyl ester, glyceryl dialkyl ester, and glyceryl trialkyl ester.
Among these, a linear or branched aliphatic carboxylic acid having 1 to 18 carbon atoms, preferably 2 to 10 carbon atoms (for example, acetic acid, butyric acid, caproic acid, caprylic acid, capric acid, lauric acid, palmitic acid) Linear aliphatic carboxylic acids such as branched aliphatic carboxylic acids such as pivalic acid) esters are preferred. The total carbon number of the alkyl group is preferably 6 or more, and more preferably 8 or more.
More specifically, glyceryl triacetate, glyceryl diacetate, glyceryl monoacetate and the like can be mentioned.

(12) Specific examples of glycol alkyl ether include glycol monoalkyl ether and glycol dialkyl ether.
Examples of the glycol (12) include ethylene glycol and neopentyl glycol, and examples of the alkyl group include linear or branched alkyl groups having 1 to 22 carbon atoms. The total carbon number of the alkyl group is preferably 6 or more, and more preferably 8 or more.
Said water-insoluble organic compounds (1)-(12) can be used individually or in mixture of 2 or more types. Among these, the water-insoluble organic compound is preferably a compound represented by the formula (1) or (2) from the viewpoint of gloss.

(Water-insoluble crosslinked polymer particles containing CB)
In the present invention, water-insoluble crosslinked polymer particles containing CB are used for improving glossiness and image clarity. The crosslinked structure of the polymer particles used in the present invention has high stability, suppresses thickening of the ink after landing on the printing surface, and smoothes the printing surface, thereby providing glossiness and mapping of the printed matter. It is thought that the property improves.
Further, when a water-insoluble organic compound is used, the crosslinked polymer has an appropriate crosslinked structure, so that the water-insoluble organic compound is easily contained. Even if the crosslinked polymer contains the water-insoluble organic compound and the polymer structure swells, It is thought that it is excellent in storage stability. If the cross-linked structure of the cross-linked polymer is too large, it is difficult to contain a water-insoluble organic compound, and if there is no cross-linkage, it is considered that the particles are easily fused together due to swelling of the polymer.
As a method for producing crosslinked polymer particles, (i) a step of obtaining water-insoluble polymer particles containing CB using CB and a water-insoluble polymer, and the obtained water-insoluble polymer particles containing CB are crosslinked with a crosslinking agent. And a step of obtaining a crosslinked polymer particle, (ii) a step of obtaining a water-insoluble crosslinked polymer by crosslinking a water-insoluble polymer with a crosslinking agent, and the obtained water-insoluble crosslinked polymer and CB. And a method of producing the crosslinked polymer particles. Among these, the method according to (i) is preferable because of easy production.

The manufacturing method by said (i) can be performed by the following process (1)-(3), for example.
Step (1): Step of obtaining a dispersion of water-insoluble polymer particles containing CB by dispersing a mixture containing a water-insoluble polymer, an organic solvent, CB, water, and, if necessary, a neutralizing agent. 2): Step of removing the organic solvent from the dispersion obtained in step (1) to obtain an aqueous dispersion of water-insoluble polymer particles containing CB Step (3): obtained in step (2) A step of obtaining crosslinked polymer particles by reacting an aqueous dispersion of water-insoluble polymer particles containing CB with a crosslinking agent.

In step (1), first, the water-insoluble polymer is dissolved in an organic solvent, and then CB, water, and, if necessary, a neutralizing agent and a surfactant are added to the obtained organic solvent solution and mixed. A method of obtaining an oil-in-water type dispersion is preferred. In the mixture, CB is preferably 5 to 50% by weight, more preferably 10 to 40% by weight, the organic solvent is preferably 10 to 70% by weight, more preferably 10 to 50% by weight, and the water-insoluble polymer is 2%. -40% by weight is preferred, 3-20% by weight is more preferred, and water is preferably 10-70% by weight, more preferably 20-70% by weight.
When the water-insoluble polymer has a salt-forming group, it is preferable to use a neutralizing agent. There is no particular limitation on the degree of neutralization when neutralizing with a neutralizer. Usually, it is preferable that the liquid pH of the finally obtained aqueous dispersion is 4.5 to 10. The pH can also be determined by the desired degree of neutralization of the water-insoluble polymer. Examples of the neutralizing agent include those described above. Further, the water-insoluble polymer may be neutralized in advance.
Examples of the organic solvent include alcohol solvents such as ethanol, isopropanol and isobutanol, ketone solvents such as acetone, methyl ethyl ketone and diethyl ketone, and ether solvents such as dibutyl ether, tetrahydrofuran and dioxane. The solubility in water is preferably 50% by weight or less and 10% by weight or more at 20 ° C., and methyl ethyl ketone is particularly preferable.

There is no restriction | limiting in particular in the dispersion method of the mixture in process (1). Although the average particle size of the polymer particles can be atomized only by the main dispersion until the desired particle size is reached, it is preferably pre-dispersed and then subjected to further dispersion by applying shear stress to obtain the average particle size of the polymer particles. It is preferable to control the diameter to a desired particle diameter. 5-50 degreeC is preferable and, as for the dispersion | distribution of a process (1), 5-35 degreeC is still more preferable.
When preliminarily dispersing the mixture, a commonly used mixing and stirring device such as an anchor blade can be used. Among the mixing and stirring devices, Ultra Disper [Asada Steel Corporation, product name], Ebara Milder [Ebara Manufacturing Co., Ltd., product name], TK Homomixer, TK Pipeline Mixer, TK Homojetter, TK Homomic Line Flow, High-speed agitating and mixing devices such as Filmix [above, Primix Co., Ltd., trade name], Clear Mix [M Technique Co., Ltd., trade name], and KD Mill [Kinetic Dispersion Co., Ltd., trade name] are preferred.
As means for applying the shear stress of this dispersion, for example, a kneader such as a roll mill, a bead mill, a kneader, an extruder, a high-pressure homogenizer (Izumi Food Machinery Co., Ltd., trade name), a minilab 8.3H type (Rannie Co., trade name) Representative homo-valve type high-pressure homogenizer, microfluidizer (Microfluidics, trade name), nanomizer (Nanomizer, trade name), optimizer (Sugino machine, trade name), Genus PY (Shiramizu Chemical Co., Ltd.) Product name], DeBEE2000 [Japan EE Co., Ltd., product name] and the like chamber type high-pressure homogenizer. A plurality of these devices can be combined.

In the step (2), an aqueous dispersion of polymer particles containing CB can be obtained by distilling the organic solvent from the obtained dispersion by a known method to form an aqueous system. The organic solvent in the aqueous dispersion containing the obtained polymer particles is substantially removed. The amount of the residual organic solvent is preferably 0.1% by weight or less, and more preferably 0.01% by weight or less.
The obtained aqueous dispersion of polymer particles containing CB is one in which the solid content of the polymer containing CB is dispersed in water as the main solvent. The aqueous dispersion may contain other solvents and additives usually used for inkjet. Here, the form of the polymer particles is not particularly limited as long as the particles are formed of at least CB and a polymer. For example, a particle form in which CB is included in the polymer, a particle form in which CB is uniformly dispersed in the polymer, a particle form in which CB is exposed on the polymer particle surface, and the like are included.

In the step (3), the obtained polymer particles containing CB are reacted with a crosslinking agent to obtain crosslinked polymer particles. Depending on the crosslinking agent used, the catalyst, solvent, temperature, and time can be appropriately selected and used.
The reaction time is preferably 0.5 to 10 hours, more preferably 1 to 5 hours, and the reaction temperature is preferably 40 to 95 ° C.
The amount of the crosslinking agent used is preferably 0.5 parts by weight or more, more preferably 0.7 parts by weight or more, based on 100 parts by weight of the water-insoluble polymer, from the viewpoint of glossiness, image clarity and storage stability. .85 parts by weight or more is more preferable, 1.0 part by weight or more is particularly preferable, and 1.5 parts by weight or more is most preferable. Further, the upper limit is preferably 15 parts by weight or less, more preferably 10 parts by weight or less, still more preferably 7 parts by weight or less, and particularly preferably 5 parts by weight or less.
From these viewpoints, 0.5 to 15 parts by weight is preferable, 0.7 to 10 parts by weight is more preferable, 0.85 to 7 parts by weight is still more preferable, and 1.0 to 5 parts by weight is most preferable.

The crosslinking rate (mol%) of the crosslinked polymer is preferably 1 to 60%, more preferably 3 to 40%, and particularly preferably 3 to 30% from the viewpoint of improving printing density, glossiness, and image clarity. is there. Here, the crosslinking rate (mol%) of the crosslinked polymer refers to a value determined by the following formula.
Crosslinking rate (mol%) = [number of moles of crosslinking agent to be reacted with 1 mole of water-insoluble polymer × 100 / number of moles of reactive groups capable of reacting with crosslinking agent of 1 mole of water-insoluble polymer]
Here, “the number of molar equivalents of the crosslinking agent to be reacted with 1 mol of the water-insoluble polymer” is obtained by multiplying the number of moles of the crosslinking agent to be reacted with 1 mol of the water-insoluble polymer by the number of reactive groups in one molecule of the crosslinking agent. Value.

(Aqueous dispersion containing crosslinked polymer particles and water-insoluble organic compound)
The aqueous dispersion for ink-jet recording of the present invention preferably contains crosslinked polymer particles and a water-insoluble organic compound.
The aqueous dispersion for inkjet recording of the present invention comprises the steps (1) to (3), and a water-insoluble organic compound is allowed to exist during or after at least one of the steps (1) to (3). Can be obtained.
Preferably, from the viewpoint of storage stability, the aqueous dispersion of polymer particles containing CB obtained in step (2) and a water-insoluble organic compound are mixed, or the crosslinked polymer particles obtained in step (3) are mixed. It is obtained by mixing an aqueous dispersion and a water-insoluble organic compound.

The mixing ratio of the aqueous dispersion of the polymer particles containing CB obtained in the step (2) and the water-insoluble organic compound is determined from the viewpoint of gloss, image clarity, and storage stability. The water-insoluble organic compound is preferably 1 to 100 parts by weight, more preferably 3 to 50 parts by weight, and still more preferably 3 to 30 parts by weight with respect to 100 parts by weight (CB and polymer).
From the viewpoint of gloss and storage stability, the mixing ratio of the aqueous dispersion of the crosslinked polymer particles obtained in the step (3) and the water-insoluble organic compound is determined based on the solid content of the aqueous dispersion of crosslinked polymer particles (CB and the crosslinked polymer). ) The water-insoluble organic compound is preferably 1 to 100 parts by weight, more preferably 3 to 50 parts by weight, and still more preferably 3 to 30 parts by weight with respect to 100 parts by weight.
The amount of the water-insoluble organic compound is preferably 5 to 300 parts by weight, more preferably 15 to 150 parts by weight with respect to 100 parts by weight of the crosslinked polymer, from the viewpoints of glossiness, image clarity and storage stability. It is preferably 20 to 150 parts by weight, more preferably 30 to 95 parts by weight.
A mixing method of an aqueous dispersion of polymer particles containing CB and a water-insoluble organic compound and a mixing method of an aqueous dispersion of crosslinked polymer particles and a water-insoluble organic compound include adding a water-insoluble organic compound to the aqueous dispersion. Or vice versa. The mixing temperature is preferably about 5 to 50 ° C. After mixing, it is also preferable to re-disperse by the above dispersion method.
In the aqueous dispersion of the present invention, at least a part of the water-insoluble organic compound is contained in the crosslinked polymer particles, and the aqueous dispersion of water-insoluble crosslinked polymer particles containing the water-insoluble organic compound and CB is obtained. .
The content of the crosslinked polymer particles in the aqueous dispersion of the present invention is preferably from 5 to 30% by weight, more preferably from 10 to 25% by weight, from the viewpoints of glossiness, image clarity and storage stability. The content of the water-insoluble organic compound in the aqueous dispersion of the present invention is preferably from 0.1 to 5% by weight, more preferably from 0.2 to 4% by weight, from the viewpoints of glossiness, image clarity and storage stability. 0.3 to 3% by weight is particularly preferable. The content of water is preferably 50 to 80% by weight, more preferably 60 to 80% by weight.

The aqueous dispersion of the present invention may be used as it is as a water-based ink, but a wetting agent, a penetrating agent, a dispersant, a viscosity modifier, an antifoaming agent, an antifungal agent, and a rust-preventing agent that are usually used in water-based inks for inkjet recording Etc. may be added.
The content of the crosslinked polymer particles in the aqueous ink of the present invention is preferably 1 to 15% by weight, and more preferably 1 to 10% by weight from the viewpoints of glossiness, image clarity and storage stability. The content of the water-insoluble organic compound in the water-based ink of the present invention is preferably from 0.1 to 5% by weight, more preferably from 0.2 to 4% by weight, from the viewpoints of glossiness, image clarity and storage stability. 0.3 to 3% by weight is particularly preferred. The content of water is preferably 50 to 80% by weight, more preferably 60 to 80% by weight.
The average particle diameter of the crosslinked polymer particles in the obtained water dispersion and water-based ink is 95 nm or less, preferably 20 to 95 nm, from the viewpoints of glossiness, image clarity, prevention of printer nozzle clogging and dispersion stability. More preferably, it is 30-90 nm, Most preferably, it is 40-85 nm.

The average particle diameter can be measured with a laser particle analysis system ELS-8000 (cumulant analysis) manufactured by Otsuka Electronics Co., Ltd. The measurement conditions are a temperature of 25 ° C., an angle between incident light and a detector of 90 °, and an integration count of 100. The refractive index of water (1.333) is input as the refractive index of the dispersion solvent. The measurement concentration is usually about 5 × 10 ⁻³ wt%.
Even if the water-insoluble organic compound is further contained in the crosslinked polymer particles, the average particle diameter of the crosslinked polymer particles is preferably in the same range as described above.
The preferred surface tension (20 ° C.) of the aqueous dispersion and aqueous ink of the present invention is preferably 30 to 70 mN / m, more preferably 35 to 68 mN / m as the aqueous dispersion, and preferably as the aqueous ink. Is 25-50 mN / m, more preferably 27-45 mN / m.
The viscosity (20 ° C.) at a solid content of 10% by weight of the aqueous dispersion is preferably 2 to 6 mPa · s, and more preferably 2 to 5 mPa · s, in order to obtain a good viscosity when used as a water-based ink. Further, the viscosity (20 ° C.) of the water-based ink is preferably 2 to 12 mPa · s, and more preferably 2.5 to 10 mPa · s, in order to maintain good ejection properties. The pH of the water-based ink is preferably 4-10.

According to the water-based ink for ink-jet recording of the present invention, it is possible to obtain a printed matter having high glossiness and image clarity when printed on dedicated paper. Examples of the special paper include ink jet photographic paper having a void-type glossy medium having a 60 ° glossiness of preferably 10 to 45 and image clarity of preferably 10 to 50. Such photographic paper is commercially available, and a preferred example is Seiko Epson Corporation trade name: KA450PSK.
The ink jet method to which the water-based ink of the present invention is applied is not limited, but is particularly suitable for a piezo ink jet printer.

In the following production examples, preparation examples, examples and comparative examples, “parts” and “%” are “parts by weight” and “% by weight” unless otherwise specified.
Production Example 1 (Production of water-insoluble polymer A)
In a reaction vessel, 20 parts of methyl ethyl ketone, 0.05 part of a polymerization chain transfer agent (2-mercaptoethanol), and 10% of 200 parts of each monomer shown in Table 1 were mixed and mixed, and nitrogen gas substitution was performed sufficiently. A mixed solution was obtained.
On the other hand, the remaining 90% of the monomer shown in Table 1 was charged into a dropping funnel, and 0.45 part of the polymerization chain transfer agent, 60 parts of methyl ethyl ketone, and a radical polymerization initiator (2,2′-azobis (2,4- Dimethylvaleronitrile)) 1.2 parts were added and mixed, and the gas was sufficiently replaced with nitrogen gas to obtain a mixed solution.
Under a nitrogen atmosphere, the mixed solution in the reaction vessel was heated to 65 ° C. while stirring, and the mixed solution in the dropping funnel was gradually dropped over 3 hours. After 2 hours at 65 ° C. from the end of dropping, a solution in which 0.3 part of the radical polymerization initiator was dissolved in 5 parts of methyl ethyl ketone was added, and further aged at 65 ° C. for 2 hours and at 70 ° C. for 2 hours, and further 115 parts of methyl ethyl ketone. In addition, the mixture was stirred for 30 minutes to obtain a polymer solution having a solid content (effective content) of about 50%. It was 150,000 as a result of measuring the weight average molecular weight of this polymer by the said method.

The details of the compounds shown in Table 1 are as follows.
(B) Styrene macromer, manufactured by Toa Gosei Co., Ltd., trade name: AS-6S, number average molecular weight: 6000, polymerizable functional group: methacryloyloxy group (d) M-90G
Polyethylene glycol monomethacrylate (average number of moles of added ethylene oxide = 9, terminal methyl group): Shin-Nakamura Chemical Co., Ltd., trade name: NK ester M-90G
(E) PP-800
Polypropylene glycol monomethacrylate (propylene oxide average added mole number = 13, terminal hydroxyl group): manufactured by NOF Corporation, trade name: BLEMMER PP-800

Production Example 2 (Production of water-insoluble organic compound A)
In a reaction vessel, 100 parts of phthalic anhydride and 400 parts of an ethylene oxide average 4 mol adduct of 2-ethylhexyl alcohol (Nippon Emulsifier Co., Ltd., trade name: New Coal 1004) and 0.5 parts of tetraisopropoxy titanate are placed. The mixture was sufficiently mixed with nitrogen gas, and then heated to 220 ° C. for esterification reaction. Furthermore, the esterification reaction was completed by performing a reduced pressure reaction at the same temperature, and the excess alcohol was removed by topping to obtain a phthalic acid diester-based water-insoluble organic compound A.
The water-insoluble organic compound A has an ethylene oxide 4-mol adduct of 2-ethylhexyl group at both ends of the basic structure derived from phthalic acid, and its LogP value (calculated value) is 6.23. The value was 9.4.

Preparation Example 1 (Preparation of aqueous dispersion 1 of CB-containing water-insoluble polymer particles)
100 parts of the polymer obtained by drying the polymer solution obtained in Production Example 1 under reduced pressure is dissolved in 200 parts of methyl ethyl ketone, and 23 parts of 5N sodium hydroxide aqueous solution (neutralization degree 60%) and ions are used as a neutralizing agent. 800 parts of exchanged water was added to neutralize the salt-forming groups, and 340 parts of carbon black (Mitsubishi Chemical Corporation, trade name: # 45, DBP oil absorption: 53 ml / 100 g) was added, and at 20 ° C. with a disper blade. The mixture was dispersed for 1 hour. The obtained dispersion was further subjected to 10-pass dispersion treatment at a pressure of 200 MPa with a microfluidizer (trade name, manufactured by Microfluidics). Methyl ethyl ketone was removed from the obtained dispersion under reduced pressure at 60 ° C., a part of water was further removed, and a 5 μm filter (acetylcellulose membrane, outer diameter: 2.5 cm, manufactured by Fuji Photo Film Co., Ltd.) was attached. An aqueous dispersion A-1 of CB-containing water-insoluble polymer particles having a solid content concentration of 18% (CB 13.9 parts) was obtained by filtering with a 25 mL needleless syringe (manufactured by Terumo Corporation) and removing coarse particles. , 4.1 parts of polymer). The results are shown in Table 2.
Preparation Examples 2 to 4 (Preparation of aqueous dispersions 2 to 4 of CB-containing water-insoluble polymer particles)
Except having used CB of Table 2, it carried out similarly to Example 1, and obtained the water dispersion A-2-4 of the CB containing water-insoluble polymer particle. The results are shown in Table 2.

Example 1
Denacol EX-810 (average molecular weight: 226, manufactured by Nagase ChemteX Corporation, epoxy equivalent) as a crosslinking agent for 100 parts of water dispersion A-1 of water-insoluble polymer particles containing CB (including 4.1 parts of water-insoluble polymer) 113) 0.075 part was added, 0.075 part of ion-exchanged water was added and the mixture was stirred at 80 ° C. for 3 hours, and then a 5 μm filter (acetylcellulose membrane, outer diameter: 2.5 cm, Fuji Photo Film Co., Ltd.) CB-containing water-insoluble cross-linked polymer particles B-1 (solid content concentration: 18%, CB13. 9 parts of an aqueous dispersion) was obtained. The amount of the crosslinking agent used relative to 100 parts of the water-insoluble crosslinked polymer particles at this time was 1.83 parts. The average particle size of the CB-containing water-insoluble crosslinked polymer particles in the aqueous dispersion B-1 was 77 nm.
The aqueous dispersion B-1 of 14.4 parts of this CB-containing water-insoluble crosslinked polymer particle (prepared to 2 parts of CB with respect to 100 parts of ink), 25 parts of glycerin, 7 parts of triethylene glycol monobutyl ether, Surfynol 465 (Nisshin) 1 part of Chemical Industry Co., Ltd.), 0.3 part of Proxel XL2 (Avisia Co., Ltd.), 1.0 part of triethyleneamine and 51.3 parts of ion-exchanged water were mixed. A water-based ink was obtained by filtering with a 25 mL needleless syringe equipped with a 2 μm filter (acetylcellulose membrane, outer diameter: 2.5 cm, manufactured by Fuji Photo Film Co., Ltd.) and removing coarse particles. The average particle size of the CB-containing water-insoluble crosslinked polymer particles in the water-based ink was 80 nm as a result of measurement by the above method.

The crosslinking rate (mol%) was calculated as follows.
Since 4.175 parts of water-insoluble polymer is reacted with 0.075 part of Denacol EX-810 (manufactured by Nagase ChemteX Corporation, ethylene glycol diglycidyl ether, epoxy equivalent 113) as a crosslinking agent, 1 mole of water-insoluble polymer The number of molar equivalents of the cross-linking agent reacted with (0.075 / 113) / (4.1 / weight average molecular weight of water-insoluble polymer (150,000)) = 24.3.
Here, since Denacol EX-810 reacts with a carboxy group and a hydroxyl group, the number of moles of the reactive group capable of reacting with the crosslinking agent possessed by 1 mole of the water-insoluble polymer is methacrylic acid (molecular weight: molecular weight: 1 mole). 86) and PP-800 (molecular weight: 840).
150,000 × 0.14 / 86 + 150,000 × 0.2 / 840 = 280 mol Therefore, the crosslinking rate (mol%) = 24.3 × 100/280 = 8.6 mol%.

Example 2
14.4 parts of the aqueous dispersion B-1 of CB-containing water-insoluble crosslinked polymer particles obtained in Example 1 and 0.26 part of the water-insoluble organic compound A obtained in Production Example 2 were mixed and stirred to obtain water. Insoluble organic compounds were included in the polymer particles. Next, 25 parts of glycerin, 7 parts of triethylene glycol monobutyl ether, 1 part of Surfinol 465 (manufactured by Nissin Chemical Industry Co., Ltd.), 0.3 part of Proxel XL2 (manufactured by Avisia Corporation), 1.0 part of triethyleneamine , And 51.04 parts of ion-exchanged water, and the resulting mixture was mixed with a 1.2 μm filter (acetylcellulose membrane, outer diameter: 2.5 cm, manufactured by Fuji Photo Film Co., Ltd.) with a capacity of 25 mL. None Filtered with a syringe to remove coarse particles, thereby obtaining a water-based ink.
The average particle size of the CB-containing water-insoluble crosslinked polymer particles B-1 in the water-based ink was 83 nm.

Example 3
CB-containing water-insoluble crosslinked polymer particles in the same manner as in Example 1, except that the water-dispersed A-2 of CB-containing water-insoluble polymer particles was used in place of the water-dispersed A-1 of CB-containing water-insoluble polymer particles. Water dispersion B-2 was obtained. The average particle size of the CB-containing water-insoluble crosslinked polymer particles in the water dispersion was 63 nm.
A water-based ink was prepared using the aqueous dispersion B-2 of CB-containing water-insoluble crosslinked polymer particles in place of the aqueous dispersion B-1 of CB-containing water-insoluble crosslinked polymer particles in Example 2.
The average particle size of the CB-containing water-insoluble crosslinked polymer particles B-2 in the water-based ink was 68 nm.

Comparative Example 1
Ink was prepared in the same manner as in Example 1 except that CB-containing water-insoluble polymer particles A-1 were used instead of CB-containing water-insoluble crosslinked polymer particles B-1. The average particle size of the CB-containing water-insoluble polymer particles A-1 in the water-based ink was 80 nm.
Comparative Example 2
CB-containing water-insoluble cross-linked polymer particles in the same manner as in Example 1, except that the water-dispersed A-3 of CB-containing water-insoluble polymer particles was used instead of the water-dispersed water-insoluble polymer particles A-1. An aqueous dispersion B-3 was obtained. The average particle size of the CB-containing water-insoluble crosslinked polymer particles in the aqueous dispersion was 103 nm.
A water-based ink was prepared in the same manner as in Example 1 using the aqueous dispersion B-3 of CB-containing water-insoluble crosslinked polymer particles. The average particle diameter of the CB-containing water-insoluble crosslinked polymer particles B-3 in the water-based ink was 102 nm.
Comparative Example 3
CB-containing water-insoluble crosslinked polymer particles in the same manner as in Example 1, except that the water-dispersed A-4 of CB-containing water-insoluble polymer particles was used in place of the water-dispersed A-1 of CB-containing water-insoluble polymer particles. Water dispersion B-4 was obtained. The average particle size of the CB-containing water-insoluble crosslinked polymer particles in the aqueous dispersion was 150 nm.
A water-based ink was prepared in the same manner as in Example 1 using the aqueous dispersion B-4 of CB-containing water-insoluble crosslinked polymer particles. The average particle size of the CB-containing water-insoluble crosslinked polymer particles B-4 in the water-based ink was 152 nm.

Next, the glossiness and image clarity of the water-based inks obtained in Examples and Comparative Examples were evaluated by the following methods.
(1) Glossiness Using a printer manufactured by Seiko Epson Corporation (model number: PX-A650, piezo method), solid printing is performed on commercially available special paper (photo paper <gloss> manufactured by Seiko Epson Corporation, trade name: KA450PSK) [ Printing condition = Paper type: Photo print paper, Mode setting: Photo], left at 25 ° C for 24 hours, and then glossiness of 20 ° is measured by a gloss meter (manufactured by Nippon Denshoku Industries Co., Ltd., trade name: HANDY GLOSSMETER PG-1 ), And the average value was obtained. The higher the value, the higher the glossiness.
(2) Image clarity Using the printer, solid printing was performed on the commercially available special paper under the above printing conditions, and after standing at 25 ° C. for 24 hours, the image clarity C value (comb width 2.0 mm) was measured as an image clarity measuring instrument ( It was measured three times with Suga Test Instruments Co., Ltd., trade name: touch panel type image measuring instrument ICM-1T), and the average value was obtained. The image clarity is to measure the sharpness or distortion when the image is reflected on the printed matter. The larger the numerical value, the clearer the reflected image is and the less distortion appears.

  From Table 3, it can be seen that the aqueous inks of Examples 1 to 3 are more excellent in glossiness and image clarity than the aqueous inks of Comparative Examples 1 to 3. Moreover, the printed matter printed by the inkjet recording system using the water-based inks of Examples 1 to 3 had a sufficient print density.

Claims (8)

An aqueous dispersion of water-insoluble crosslinked polymer particles containing carbon black, wherein the carbon black has a DBP oil absorption of 40 to 65 ml / 100 g, and the water-insoluble crosslinked polymer particles have an average particle size of 95 nm or less, Furthermore, it contains a water-insoluble organic compound having a solubility in 100 g of water (20 ° C.) of 5 g or less, and the water-insoluble organic compound has an ester or ether compound (f) having two or more ester or ether bonds in the molecule, And / or at least one ester or ether bond in the molecule and one or more functional groups selected from the group consisting of carboxy group, sulfonic acid group, phosphoric acid residue, carbonyl group, epoxy group and hydroxyl group. An aqueous dispersion for inkjet recording, which is an ester or ether compound (g) having at least one.   The aqueous dispersion for inkjet recording according to claim 1, wherein the water-insoluble crosslinked polymer particles are a polymer obtained by crosslinking 0.5 to 15 parts by weight of a crosslinking agent with respect to 100 parts by weight of the water-insoluble polymer.   The water dispersion for inkjet recording according to claim 1 or 2, wherein the water-insoluble polymer has a weight average molecular weight of 5,000 to 500,000.   The aqueous dispersion for inkjet recording according to any one of claims 1 to 3, wherein the crosslinking agent is a compound having two or more epoxy groups in the molecule.   The water-insoluble polymer is a water-insoluble vinyl polymer obtained by copolymerizing a monomer mixture containing (a) a salt-forming group-containing monomer, (b) a macromer and / or (c) a hydrophobic monomer. The water dispersion for inkjet recording in any one.   The water-insoluble organic compound is at least one selected from the group consisting of aliphatic dicarboxylic acid esters, aromatic di- or tricarboxylic acid esters, cycloalkane (ken) dicarboxylic acid esters, and phosphoric acid di- or triesters. The water dispersion for inkjet recording in any one of -5.   The aqueous dispersion for inkjet recording according to any one of claims 1 to 6, wherein the amount of the water-insoluble organic compound is 5 to 300 parts by weight with respect to 100 parts by weight of the water-insoluble crosslinked polymer.   An aqueous ink for inkjet recording, comprising the aqueous dispersion for inkjet recording according to any one of claims 1 to 7.