JPH11246640A - Aqueous dispersion, coating material for ink jet recording and sheet for ink jet recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an aqueous dispersion capable of developing excellent ink receptivity, water resistance, etc., useful as a coating material for ink jet recording by adding a polymer obtained by polymerizing a specific monomer component in an aqueous medium. SOLUTION: This aqueous dispersion comprises a polymer obtained by polymerizing (A) 100 pts.wt. of a radically polymerizable monomer component in the presence of (B) 5-50 pts.wt. of a hydroxyl group-containing water-soluble polymer. The component A preferably contains an N-alkyl(meth)acrylamide. The component A may contain an ethylenic unsaturated monomer containing a carbonyl group based on an aldo group or a keto group. In the case in which the component A contains an ethylenic unsaturated monomer containing a carbonyl group, preferably the component A comprises a polyfunctional hydrazine derivative containing at least two hydrazino groups in one molecule. Preferably the obtained polymer has >=-20 deg.C glass transition temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an aqueous dispersion, a coating material for ink jet recording, and a sheet for ink jet recording.

[0002]

2. Description of the Related Art The ink jet recording method has the advantages that noise during printing can be suppressed and that color printing and high-speed printing are possible. Therefore, the range of application is wide-ranging, such as facsimile and various printers. As a recording medium used by this method, paper and a plastic film sheet are mainly used. Further, a coating material for ink jet recording is formed on the surface of the recording medium so as to regret the function of the ink jet recording machine.

[0003] However, in order to improve the technology of the ink jet recording machine, it has become possible to further increase the speed of printing and increase the number of colors, and accordingly, it is required to further improve the recording medium for ink jet recording. It is becoming. That is, ink acceptability, water resistance, blocking resistance, curling resistance, etc. are required, and in the case of a plastic film sheet, in addition to the above-mentioned properties, transparency is also required for the coating layer. Have been. In order to respond to this requirement, various types of studies have been conducted, but even if any of the properties have been improved, these properties have not been improved at the same time, and the requirements have not yet been fully met. is the current situation.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording sheet having excellent ink receptivity, water resistance, transparency, curl resistance and blocking resistance, and coating of the ink jet recording sheet. It is an object of the present invention to provide a coating material for ink jet recording useful as a composition for printing and an aqueous dispersion useful as a main component of the coating material for ink jet recording.

[0005]

Means for Solving the Problems The aqueous dispersion of the present invention comprises:
In an aqueous medium, a hydroxyl group-containing water-soluble polymer 5 to 50 parts by weight per 100 parts by weight of a radically polymerizable monomer component.
It is obtained by polymerizing the radically polymerizable monomer component in the presence of 0 parts by weight.

[0006] The aqueous dispersion of the present invention can exhibit well-balanced and excellent ink receptivity, water resistance, transparency, curl resistance and blocking resistance. That is,
Excellent ink receptivity is exhibited based on the water absorption of the hydroxyl group-containing water-soluble polymer. However,
In terms of water resistance, curl resistance and blocking resistance, in the hydroxyl group-containing water-soluble polymer,
Not enough. The polymer obtained by polymerizing the monomer component capable of radical polymerization is excellent in water resistance, curling resistance and blocking resistance, and the like. By coexisting with these, these various properties can be improved and improved. Furthermore, in the presence of a hydroxyl group-containing water-soluble polymer, by polymerizing the radically polymerizable monomer component, micro-level compatibilization is promoted, and
The aqueous dispersion of the present invention thus obtained is a blend of a polymer obtained by simply mixing a polymer obtained by polymerizing the monomer component and a hydroxyl group-containing water-soluble polymer. An aqueous dispersion can exhibit transparency that is difficult to obtain.

Further, the radically polymerizable monomer component desirably contains N-alkyl (meth) acrylamide.

An aqueous dispersion obtained by polymerizing a radically polymerizable monomer component containing N-alkyl (meth) acrylamide further improves ink receptivity due to the water absorption of N-alkyl (meth) acrylamide. Can be done. Further, the N-alkyl (meth) acrylamide is quaternized by using a suitable quaternizing agent, so that the cationic group of the quaternized N-alkyl (meth) acrylamide and Since the anionic group of the anionic dye and the anionic group form an ionic bond, the adhesive force between the polymer of the aqueous dispersion and the anionic dye in the aqueous ink is increased, and as a result, the ink receptivity and the ink fixing property are improved. Further improvement can be achieved.

The radically polymerizable monomer component may include an ethylenically unsaturated monomer having a carbonyl group based on an ald group or a keto group.

An aqueous dispersion obtained by containing the radically polymerizable monomer component and the ethylenically unsaturated monomer having a carbonyl group based on an ald group or a keto group is further included in one molecule. It is further desirable to include a polyfunctional hydrazine derivative having at least two hydrazino groups.

The polymer of the aqueous dispersion contains a carbonyl group based on an ald group or a keto group, and the aqueous dispersion contains a polyfunctional hydrazine derivative having at least two hydrazino groups in one molecule. By being included, when the aqueous dispersion is formed into a film, a dehydration condensation reaction occurs between the carbonyl group and the hydrazino group, and the polymer is further crosslinked, so that the water resistance of the coating film can be further improved. it can. Further, by forming a crosslinked structure in the coating film, form maintenance is imparted, and as a result, curling resistance can be further improved.

Further, the glass transition temperature of the polymer obtained by polymerizing the radically polymerizable monomer component is -2.
It is desirable that the temperature is 0 ° C. or higher. When the glass transition temperature of the polymer is less than -20 ° C, the coating film formed by forming the aqueous dispersion tends to be tacky and have poor blocking resistance.

When the ink-jet recording coating material containing the aqueous dispersion of the present invention as a main component is applied to an ink-jet recording sheet, the ink-jet recording coating material has excellent ink receptivity and water resistance. , An ink jet recording sheet having transparency, blocking resistance, curling resistance and the like.

Thus, the ink jet recording sheet of the present invention achieves the above object and can be suitably applied to a facsimile, various printers and the like.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail.

The radically polymerizable monomer component used in the production of the aqueous dispersion of the present invention is an essential component for imparting ink receptivity, water resistance and blocking resistance. Examples of the monomer of the monomer component include the following.

For example, N-alkyl (meth) acrylamide; an ethylenically unsaturated monomer having a carbonyl group based on an ald group or a keto group; methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) Acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, n-amyl (meth) acrylate, (cyclo) alkyl (meth) acrylates such as i-amyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate and cyclohexyl (meth) acrylate; 2 -Methoxyethyl (meth) Acrylate, 2-ethoxyethyl (meth) acrylate, 2-methoxypropyl (meth)
Acrylate, 3-methoxypropyl (meth) acrylate, 2-methoxybutyl (meth) acrylate, 3-
Alkoxy (cyclo) alkyl (meth) acrylates such as methoxybutyl (meth) acrylate, 4-methoxybutyl (meth) acrylate and p-methoxycyclohexyl (meth) acrylate; hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) ) Acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2
-Hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 5-hydroxyamyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxycyclohexyl Hydroxy (cyclo) alkyl mono (meth) acrylates of dihydric alcohols such as (meth) acrylate and neopentyl glycol mono (meth) acrylate; 3-chloro-2-
Substituted hydroxy (cyclo) alkyl mono (meth) acrylates such as hydroxypropyl (meth) acrylate and 3-amino-2-hydroxypropyl (meth) acrylate; glycerin mono- or di- (meth) acrylate, and trimethylolpropane Mono- or di-
(Meth) acrylates, free hydroxyl group-containing (meth) acrylates of trihydric or higher polyhydric alcohols such as mono-, di- or tri- (meth) acrylates of pentaerythritol; N-methylol (meth) acrylamide, N,
N-methylolated unsaturated carboxylic amides such as N-dimethylol (meth) acrylamide; unsaturated epoxy compounds such as allyl glycidyl ether, glycidyl (meth) acrylate, methyl glycidyl methyl acrylate, epoxidized cyclohexyl (meth) acrylate; Vinyl esters such as vinyl, vinyl propionate and vinyl versatate; fluoroalkyl (meth) acrylates such as perfluoroethyl (meth) acrylate, perfluoropropyl (meth) acrylate and pentadecafluorooctyl (meth) acrylate; 2 -Dimethylaminoethyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, 2-dimethylaminopropyl (meth) acrylate, 3-dimethylaminopropyl (meth) Aminoalkyl group-containing (meth) acrylates such as acrylate; 2-dimethylaminoethyl acrylamide, 2-diethylaminoethyl acrylamide, 2-dimethylaminopropyl acrylamide,
Aminoalkyl group-containing acrylamides such as 3-dimethylaminopropylacrylamide; 2- (dimethylaminoethoxy) ethyl (meth) acrylate, 2- (diethylaminoethoxy) ethyl (meth) acrylate, 3
Aminoalkoxyalkyl group-containing (meth) acrylates such as-(dimethylaminoethoxy) propyl (meth) acrylate; ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate,
Triethylene glycol (meth) diacrylate, tetraethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) ) Acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 2,2′-bis [4- (meth)
Acryloxypropoxyphenyl] propane, 2,
Polyfunctional (meth) acrylates such as 2'-bis [4- (meth) acryloxydiethoxyphenyl] propane, glycerin tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, and pentaerythritol tetra (meth) acrylate Styrene, α-
Methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-ethylstyrene, 4-
t-butylstyrene, 3,4-dimethylstyrene, 4-
Methoxystyrene, 4-ethoxystyrene, 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene,
2,4-dichlorostyrene, 2,6-dichlorostyrene, 4-chloro-3-methylstyrene, divinylbenzene, 1-vinylnaphthalene, 2-vinylpyridine, 4-
Aromatic vinyl compounds such as vinylpyridine; (meth) acrylic acid, crotonic acid, cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, monomethyl maleate, monoethyl maleate, monomethyl itaconate, monoethyl itaconate , Hexahydrophthalic acid mono-2-
Carboxyl group-containing unsaturated monomers such as (meth) acryloyloxyethyl and the like or anhydrides thereof; (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N,
N-dimethoxymethyl (meth) acrylamide, N, N
-Methylenebis (meth) acrylamide, N, N-ethylenebis (meth) acrylamide, maleic amide,
Amides or imides of unsaturated carboxylic acids such as maleimide; (meth) acrylonitrile, crotonitrile,
Cyano group-containing unsaturated monomers such as 2-cyanoethyl (meth) acrylate, 2-cyanopropyl (meth) acrylate, 3-cyanopropyl (meth) acrylate, and cinnamate nitrile; vinyl chloride, vinylidene chloride, and fatty acid vinyl Vinyl halide compounds such as esters; 1,3-
Conjugated dienes such as butadiene, isoprene, chloroprene, and 2,3-dimethyl-1,3-butadiene; γ- (meth) acryloxypropyltrimethoxysilane; In addition to polymerizable silicones, 2- (2′-hydroxy-
5'-methacryloxyethylphenyl) -2H-benzotriazole, 2- (2'-hydroxy-5'-methacryloxyethyl-3'-t-butylphenyl) -2H-
UV-absorbing functional group-containing (meth) acrylates such as benzotriazole; 1,2,2,6,6-pentamethyl-4-piperidyl (meth) acrylate;
(Meth) acrylates having a light stabilizing group such as 6,6-tetramethyl-4-piperidyl (meth) acrylate are exemplified.

Of these, N-alkyl (meth) acrylamide, ethylenically unsaturated monomers having a carbonyl group based on an ald group or a keto group, methyl (meth) acrylate, ethyl (meth) acrylate, n-alkyl
Butyl (meth) acrylate, styrene, (meth) acrylamide, 2-hydroxyethyl (meth) acrylate, N- (3-dimethylaminopropyl) (meth) acrylamide and the like are preferred, and N-alkyl (meth) acrylamide is particularly preferred. And ethylenically unsaturated monomers having a carbonyl group based on an ald group or a keto group.

Examples of the N-alkyl (meth) acrylamide include N-monoalkyl (meth) acrylamide having 1 to 10 carbon atoms in the alkyl group, N, N-dialkylacrylamide, specifically N-methylacrylamide, N-ethylacrylamide, Nn-propylacrylamide, Ni-propylacrylamide, N, N
-Dimethylacrylamide, N, N-diethylacrylamide, N, N-di (n-propyl) acrylamide,
N, N-di (i-propyl) acrylamide, N, N-
Examples include dimethyl methacrylamide, N, N-diethyl methacrylamide, N, N-di (n-propyl) methacrylamide, and N, N-di (i-propyl) methacrylamide. -Methylacrylamide, N, N-dimethylacrylamide and the like are preferred. The N-alkyl (meth) acrylamides can be used alone or in combination of two or more.

When such N-alkyl (meth) acrylamide is used, its preferred amount is from 0.1 to 100 parts by weight of the radically polymerizable monomer component.
80 parts by weight, more preferably 1 to 40 parts by weight,
Particularly preferably, it is 2 to 30 parts by weight. If the amount of N-alkyl (meth) acrylamide is less than 0.1 part by weight, ink receptivity tends to be poor. On the other hand, if it exceeds 80 parts by weight, water resistance tends to be poor.

Among the ethylenically unsaturated monomers having a carbonyl group based on an ald group or a keto group, examples of the ethylenically unsaturated monomer having an ald group include (meth) acrolein, crotonaldehyde, formylstyrene, Formyl-α-methylstyrene, diacetone acrylamide, (meth) acrylamide pivalinaldehyde, 3- (meth) acrylamidomethyl-anisaldehyde, and β- (meth) represented by the following (formula 1)
Acryloxy-α, α-dialkylpropanals can be exemplified.

[0022]

Embedded image [In the formula 1, R ₁ represents a hydrogen atom or a methyl group;
R ₂ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ₃ represents an alkyl group having 1 to ₃ carbon atoms, and R ₄ represents an alkyl group having 1 to ₄ carbon atoms. Β- (meth) acryloxy-α, α represented by (Formula 1)
-Specific examples of dialkylpropanals include β-
(Meth) acryloxy-α, α-dimethylpropanal (ie, β- (meth) acryloxypivalinaldehyde), β- (meth) acryloxy-α, α-diethylpropanal, β- (meth) acryloxy-α, α-dipropylpropanal, β- (meth) acryloxy-α-
Methyl-α-butylpropanal, β- (meth) acryloxy-α, α, β-trimethylpropanal and the like can be mentioned.

Examples of the ethylenically unsaturated monomer having a keto group include diacetone (meth) acrylamide and vinyl alkyl ketones having 4 to 7 carbon atoms (for example, vinyl methyl ketone, vinyl ethyl ketone,
Vinyl-n-propyl ketone, vinyl-i-propyl ketone, vinyl-n-butyl ketone, vinyl-i-butyl ketone, vinyl-t-butyl ketone, etc.), vinyl phenyl ketone, vinyl benzyl ketone, divinyl ketone, diacetone (meth) acrylate , Acetonitrile (meth) acrylate, 2-hydroxypropyl (meth) acrylate-acetyl acetate, 3-hydroxypropyl (meth) acrylate-acetyl acetate, 2-
Hydroxybutyl (meth) acrylate-acetyl acetate, 3-hydroxybutyl (meth) acrylate-
Acetyl acetate, 4-hydroxybutyl (meth) acrylate-acetyl acetate, butanediol-
1,4- (meth) acrylate-acetyl acetate and the like. Of these, acrolein, diacetone acrylamide, vinyl methyl ketone and the like are particularly preferred.

The ethylenically unsaturated monomers having a carbonyl group can be used alone or in combination of two or more.

When such an ethylenically unsaturated monomer having a carbonyl group is used, its preferred amount is
For 100 parts by weight of a radically polymerizable monomer component,
0.1 to 20 parts by weight, more preferably 0.5 to
10 parts by weight, particularly preferably 1.0 to 8 parts by weight.
The amount of the ethylenically unsaturated monomer having a carbonyl group is 0.1.
If it is less than 1 part by weight, water resistance tends to be poor. On the other hand, if it exceeds 20 parts by weight, ink receptivity tends to be poor.

When the radically polymerizable monomer component contains an ethylenically unsaturated monomer having a carbonyl group, the aqueous dispersion contains a polyfunctional compound having at least two hydrazino groups in one molecule. The ratio (B) / (A) of the equivalent of the hydrazino group (B) in the polyfunctional hydrazine derivative to the equivalent of the carbonyl group (A) in the aqueous dispersion is preferably 0.1 to 0.1. 5, more preferably 0.5 to 1.5, particularly preferably 0.7 to 1.
It is more desirable to include them in the range of 2. When the ratio (B) / (A) is less than 0.1, the effect of improving the water resistance due to the addition of the polyfunctional hydrazine derivative is not sufficient, while the ratio (B) / (A) is insufficient. If it exceeds 5, water resistance and transparency tend to be inferior.

Examples of the polyfunctional hydrazine derivative having at least two hydrazino groups in one molecule include oxalic dihydrazide, malonic dihydrazide, succinic dihydrazide, glutaric dihydrazide, adipic dihydrazide, sebacic dihydrazide, and phthalic acid. Dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide, etc.
In particular, dicarboxylic dihydrazides having a total of 4 to 6 carbon atoms;
Citric acid trihydrazide, nitrilic acid trihydrazide,
Trifunctional or higher hydrazides such as cyclohexanetricarboxylic acid trihydrazide and ethylenediaminetetraacetic acid tetrahydrazide; ethylene-1,2-dihydrazine, propylene-1,2-dihydrazine, propylene-1,3-dihydrazine, butylene-1 , 2-dihydrazine, butylene-1,3-dihydrazine, butylene-1,4-dihydrazine, butylene-2,3-dihydrazine and the like; aliphatic dihydrazines having a total of 2 to 4 carbon atoms; Sex dihydrazine.

Further, at least a part of the hydrazino group of these polyfunctional hydrazine derivatives is converted to a carbonyl such as acetaldehyde, propionaldehyde, butyraldehyde, acetone, methyl ethyl ketone, diethyl ketone, methyl propyl ketone, methyl butyl ketone, diacetone alcohol and the like. Compounds blocked by reacting with compounds (hereinafter, referred to as “blocked polyfunctional hydrazine derivatives”), for example, dihydrazide monoacetone hydrazone adipate, dihydrazide acetone hydrazone adipate, and the like can also be used. By using such a blocked polyfunctional hydrazine derivative, the progress of the crosslinking reaction of the aqueous dispersion can be controlled. Among these polyfunctional hydrazine derivatives, adipic dihydrazide, sebacic dihydrazide, isophthalic dihydrazide, adipic dihydrazide acetone hydrazone and the like are preferable. The polyfunctional hydrazine derivatives may be used alone or in combination of two or more.

Examples of the hydroxyl group-containing water-soluble polymer include polyvinyl alcohol, completely saponified polyvinyl alcohol, partially saponified polyvinyl alcohol, cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, silicon-modified polyvinyl alcohol, terminal thiol-modified polyvinyl alcohol, and acetoacetyl-modified. Various polyvinyl alcohols such as polyvinyl alcohol, methyl cellulose, hydroxyethyl cellulose,
In addition to celluloses such as carboxymethylcellulose, various starches, polyethylene glycol, and the like, hydroxyl group-containing acrylic water-soluble polymers and the like can be mentioned. In particular, partially saponified polyvinyl alcohol, terminal thiol-modified polyvinyl alcohol, and hydroxyl group-containing acrylic water-soluble polymer Polymers and the like are preferred.

The hydroxyl group-containing water-soluble polymer is an essential component for introducing the hydroxyl group which is a crosslinkable functional group in addition to ink receptivity and water absorption. The amount is 5 to 500 parts by weight, preferably 30 to 300 parts by weight, more preferably 50 to 200 parts by weight, based on 100 parts by weight of the monomer component. If the amount is less than 5 parts by weight, ink acceptability will be poor, and if it exceeds 500 parts by weight, sharpness, water resistance and curl resistance will be poor.

The aqueous dispersion of the present invention is prepared by mixing the above-mentioned hydroxyl group-containing water-soluble polymer 5 to 500 with respect to 100 parts by weight of the radically polymerizable monomer component in an aqueous medium.
It is obtained by polymerizing the radically polymerizable monomer component in the presence of parts by weight.

The glass transition temperature of the polymer of the aqueous dispersion of the present invention is preferably -20 ° C. or higher, more preferably 0 ° C.
C. or higher, particularly preferably 10 ° C. or higher. If the glass transition temperature is lower than -20 ° C, the blocking resistance tends to be poor.

The polymerization of the radically polymerizable monomer in the present invention is not particularly limited as long as the produced polymer is dispersed as particles in an aqueous medium.
Emulsion polymerization is particularly preferred. The emulsion polymerization, in addition to the hydroxyl group-containing water-soluble polymer, a monomer component capable of radical polymerization, if necessary, various emulsifiers, a chain transfer agent,
Water is usually added to 100 parts by weight of a radically polymerizable monomer component by using an electrolyte and a pH adjuster in combination with 100 parts by weight.
Using a radical polymerization initiator and the like at a polymerization temperature of 5 to 100 ° C, preferably 40 to 90 ° C,
Emulsion polymerization is carried out under the conditions of a polymerization time of 0.1 to 10 hours. Further, the polymerization conversion of the obtained polymer is preferably 95% or more.

Examples of the radical polymerization initiator include an oxidizing agent comprising an organic hydroperoxide such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramenthane hydroperoxide and a sugar-containing iron pyrophosphate formulation, sulfoxylate. Redox initiators in combination with reducing agents such as prescriptions, sugar-containing iron pyrophosphate prescriptions / sulfoxylate prescriptions; persulfates such as potassium persulfate and ammonium persulfate; azobisisobutyronitrile, dimethyl −
2,2'-azobisisobutyrate, 2-carbamoylazaisobutyronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis [2-
(2-imidalin-2-yl) propane] azo compounds such as dihydrochloride; organic peroxides such as benzoyl peroxide, lauroyl peroxide, t-butylperoxy-2-ethylhexanoate; and the like. 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride And the like. These radical polymerization initiators can be used alone or in combination of two or more. The amount of the radical polymerization initiator used is usually 0.05 to 5 based on 100 parts by weight of the monomer component used.
Parts by weight, preferably about 0.1 to 2 parts by weight.

In the emulsion polymerization, the hydroxyl group-containing water-soluble polymer itself functions as an emulsifier, and one or more emulsifiers may be used in some cases.

Examples of such emulsifiers include anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, and water-soluble polymers other than hydroxyl group-containing water-soluble polymers. Coalescence or the like can be used.

Examples of the anionic surfactant include an alkali metal salt of a higher alcohol sulfate, an alkali metal salt of an alkylbenzene sulfonic acid, an alkali metal salt of a dialkyl succinate sulfonic acid, and an alkali metal salt of an alkyl diphenyl ether disulfonic acid. ,
In addition to polyoxyethylene alkyl (or alkyl phenyl) ether sulfates, polyoxyethylene alkyl (or alkyl phenyl) ether phosphates and the like, Latemul S-180A (Kao Corporation)
), Eleminol JS-2 (manufactured by Sanyo Kasei Co., Ltd.), Aqualon HS-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Adecaria Soap SE-10N (manufactured by Asahi Denka Kogyo Co., Ltd.), etc. Anionic surfactants can be mentioned.

Examples of the nonionic surfactant include, for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, etc., Aqualon RS-20 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and Adecaria Soap NE- And 20 (manufactured by Asahi Denka Kogyo KK).

Examples of the cationic surfactant include alkylpyridinyl chloride, alkylamine acetate, alkylammonium chloride and the like.
Reactive cationic surfactants such as diallylammonium halides described in Japanese Patent No. 235631 can be used.

As the amphoteric surfactant, lauryl betaine is suitable, and as the water-soluble polymer, an ionic water-soluble polymer containing no hydroxyl group such as an alkali-soluble polymer can be used. Among them, it is particularly preferable to use a nonionic emulsifier and a cationic emulsifier. The amount of these emulsifiers used is
It is usually 5 parts by weight or less per 0 parts by weight, and 50 parts by weight or less in the case of a water-soluble polymer.

As the chain transfer agent (molecular weight adjusting agent), any of those usable in ordinary polymerization can be used. Specifically, halogenated hydrocarbons such as chloroform and bromoform; Dodecyl mercaptan,
mercaptans such as t-dodecyl mercaptan, n-octyl mercaptan, n-octyl thioglycol;
Xanthogens such as dimethyl xanthogen disulfide and diisopropylxanthogen disulfide; terpenes such as dipentene and terpinolene; unsaturated cyclic carbonization such as 9,10-dihydroanthracene, 1,4-dihydronaphthalene, indene and 1,4-cyclohexadiene Hydrogen compounds; unsaturated heterocyclic compounds such as xanthene and 2,5-dihydrofuran; α-methylstyrene dimer, 1,1-diphenylethylene and the like can be used. The amount of the chain transfer agent to be used is generally about 0 to 5 parts by weight per 100 parts by weight of the monomer mixture. is necessary.

As the polymerization system, a batch system, a system in which monomers are divided or continuously added, a system in which a pre-emulsion of a monomer is divided or continuously added, or a system in which these systems are combined stepwise In particular, when a monomer having low water solubility is used, a hydroxyl group-containing water-soluble polymer, an ethylenically unsaturated monomer may be used in advance using a high-pressure homogenizer or an ultrasonic disperser. After pre-emulsion is prepared by forcibly emulsifying water, polymerization is preferably carried out by a batch polymerization method, a divided or continuous addition method, or the like. In the present invention,
In the case of the emulsion polymerization as described above, if necessary, and within a range that does not impair the purpose of the present invention, specifically, within a range that does not impair workability, disaster prevention safety, environmental safety, and manufacturing safety, Small amounts of solvent can be used.

Examples of the solvent include methyl ethyl ketone, acetone, trichlorotrifluoroethane,
Methyl isobutyl ketone, dimethyl sulfoxide, toluene, dibutyl phthalate, methyl pyrrolidone, ethyl acetate, alcohols, cellosolves, carbitols and the like are used. The solvent can be used usually in an amount of about 0 to 10 parts by weight per 100 parts by weight of the monomer mixture.
In order to obtain the effect of adding a solvent, it is necessary to add at least 0.1 part or more.

The following additives can be added to the aqueous dispersion of the present invention according to the purpose.

One or more inorganic pigments or organic pigments can be used in order to improve the ink receptivity (absorbency) of the obtained coating film or to color the recording sheet. These inorganic pigments or organic pigments are not particularly limited.Examples of inorganic pigments include clay, barium sulfate, titanium oxide, calcium carbonate, satin white, talc, aluminum hydroxide, zinc oxide, and the like. Is polystyrene latex,
Urea formalin resin and the like can be used.

For the purpose of improving the weather resistance and light resistance of the obtained coating film, a light stabilizer and an ultraviolet absorber can be added. Such light stabilizers and ultraviolet absorbers are not particularly limited, and organic nickel compounds, light stabilizers such as hindered amines, inorganic ultraviolet absorbers such as titanium oxide, zinc oxide and cerium oxide, benzophenone Any light stabilizer that can be conventionally used for paints, synthetic rubbers, synthetic resins, and synthetic fibers, such as organic ultraviolet absorbers such as benzotriazole and the like, may be used. Of these, bis (1,2,2,6,6-pentamethyl-
Hindered amine light stabilizers such as (4-piperidyl) sebacate; cerium oxide; and hindered amine ultraviolet absorbers. The addition amount of these light stabilizers or ultraviolet absorbers is 10 parts by weight or less, preferably 5 parts by weight or less based on 100 parts by weight of the aqueous polymer (solid content). In order to obtain it, it is necessary to add at least 0.1 part by weight or more.

In order to improve the film forming property and wettability of the obtained coating film, alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, amyl alcohol and hexyl alcohol, methyl cellosolve, ethyl cellosolve, etc. One or more organic solvents such as propyl cellosolve, butyl cellosolve, hexyl cellosolve, methyl carbitol, ethyl carbitol, methyl cellosolve acetate, ethyl cellosolve acetate, and tribubutoxymethyl phosphate can be used. The amount of these organic solvents used is 20% by weight or less, preferably 10% by weight or less, more preferably 5% by weight or less in the total composition. Addition of 1% by weight or more is necessary.

Further, a conventionally used crosslinking agent can be added to improve the water resistance of the obtained coating film. Here, as the cross-linking agent, any one that reacts with various functional groups introduced into a polymer obtained by polymerizing a hydroxyl group or a radical polymerizable monomer component in a hydroxyl group-containing water-soluble polymer can be used. For example, in addition to melamine resin, phenol resin, epoxy resin and the like, aldehydes such as gliogizar, dimethylol urea and formalin, which are generally used as a crosslinking agent for polyvinyl alcohol, can be mentioned. These crosslinkers are
Usually, it can be used at a curing temperature of 0 to 280 ° C, but it is desirable to use a phenol resin or the like at a curing temperature of 100 ° C or more. As the melamine resin,
Examples include a methylated melamine resin, a butylated melamine resin, a methylolated melamine resin, a mixed etherified melamine resin, and the like. Examples of the phenol resin include dimethylol resin, polymethylol phenol resin, phenol formamide resin, methylol phenol formamide resin, and dimethylol phenol formamide resin. Examples of the epoxy resin include ethylene glycol diglycidyl ether, hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, glycerin diglycidyl ether,
Glycerin / polyglycidyl ether, diglycerin /
Polyglycidyl ether, polyglycidyl ether of polyhydric alcohol such as sorbitol / polyglycidyl ether, hydrogenated bisphenol A / diglycidyl ether or bisphenol A / diglycidyl ether, or glycidyl ether of p-oxybenzoic acid, diglycidyl phthalate Alternatively, hexahydrophthalic acid / diglycidyl ether, an epoxy resin containing a hydantoin ring, and a vinyl polymer having an epoxy group in a side chain may be used.

Further, in order to improve the fixability of the anionic dye on the obtained coating film, a cationic surfactant, a cationic polymer and the like can be added.

Further, as additives other than the above-mentioned additives,
Water-soluble polyester resin commonly used as a water-soluble polymer, water-soluble epoxy resin, water-soluble acrylic resin,
Polyvinyl alcohol, carboxymethyl cellulose,
In addition to polyoxyethylene, starch, gelatin, etc., it is also possible to use antifoaming agents, thickening agents, heat stabilizers, wetting agents, leveling agents, lubricants, coloring agents, matting agents, pigments, fungicides, etc. it can.

The aqueous dispersion of the present invention forms a coating film having excellent ink receptivity (absorptivity), water resistance, transparency, blocking resistance and curling resistance. Paper, wood, metal,
It can be used for various coating agents such as concrete, ceramics, slate, marble, porcelain, gypsum, leather, etc., as well as antistatic additives, ink binders,
It can also be used for battery separators, adhesives, cement admixtures, sealants, paper impregnation, textile processing, etc., especially as a coating material for inkjet recording.
It can be suitably used for an ink jet recording sheet.

In applying the coating material comprising the aqueous dispersion of the present invention, a conventionally known method such as brush coating, a blade coater, a roll coater, a spin coater, or an electrodeposition method can be employed. In addition, when a coating material containing the aqueous dispersion of the present invention is applied to a plastic film such as a polyester film, in addition to a post-coat for coating a formed film, a uniaxial stretching or a biaxial stretching step may be performed. It can also be used as a precoat for coating.

The ink jet recording sheet coated with the ink jet recording coating material of the present invention can be preferably applied to facsimile, copy, printing machines, various printers and the like by an ink jet recording system.

[0054]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. In Examples, "parts" and "%" indicating percentages mean parts by weight and% by weight, respectively.

(Example 1) Stirrer, thermometer, heater,
In a stainless steel autoclave equipped with a monomer addition pump and a nitrogen gas introduction device, water 40 was used as an initial component.
Equivalent to 0 parts, partially saponified polyvinyl alcohol (brand name Kuraray PVA-2) as a hydroxyl group-containing water-soluble polymer
03 50 parts of a 20% aqueous solution of Kuraray Co., Ltd. (in terms of solid content), 2,2′-azobis (2-amidinopropane)
0.5 part (in terms of solid content) of a 5% aqueous solution of dihydrochloride (trade name: V-50, manufactured by Wako Pure Chemical Industries, Ltd.) was charged, the gas phase was replaced with nitrogen gas for 15 minutes, and then heated to 65 ° C. Warmed.

Then, emulsion polymerization was carried out at 70 ° C. while continuously adding the monomer components shown in Table 1 over 3 hours, and after completion of the addition, aging was carried out at 75 to 80 ° C. for 2 hours.
Thereafter, the mixture is cooled to 25 ° C., and 1 part of a 10% aqueous solution of adipic dihydrazide as the polyfunctional hydrazine derivative (in terms of solid content, at least two hydrazine derivatives in one molecule with respect to the equivalent (A) of the carbonyl group in the aqueous dispersion) are obtained. The ratio (B) / (A) = 1) of the equivalent (B) of the hydrazino group in the polyfunctional hydrazine derivative having a hydrazino group was added thereto, and the mixture was stirred for about 1 hour. And filtered through a 200-mesh wire gauze to obtain an aqueous dispersion.

Example 2 In an autoclave similar to that in Example 1, 400 parts of water was used as an initial component, and a cation-modified polyvinyl alcohol (trade name: Kuraray C-506, manufactured by Kuraray Co., Ltd.) as a water-soluble polymer having a hydroxyl group. )
25 parts (solid content) of a 20% aqueous solution of polyethylene glycol (trade name polyethylene glycol 20,000, manufactured by Wako Pure Chemical Industries, Ltd.) as a hydroxyl group-containing water-soluble polymer (solid content conversion) ), 1 part (in terms of solid content) of a 20% aqueous solution of lauryltrimethylammonium chloride (trade name: Cotamine 24P, manufactured by Kao Corporation), 2,2′-azobis (2-amidinopropane) dihydrochloride (trade name: V-50) 1.0 part (solid content conversion) of a 5% aqueous solution of Wako Pure Chemical Industries, Ltd.) was charged, and the gas phase was purged with nitrogen gas for 15 minutes, and then heated to 65 ° C.

Next, emulsion polymerization was carried out at 70 ° C. while continuously adding the monomer components shown in Table 1 over 3 hours, and after completion of the addition, aging was carried out at 75 to 80 ° C. for 2 hours.
Then, after cooling to 25 ° C., the solid content concentration was reduced to 2 with water.
It was adjusted to 5% and filtered through a 200-mesh wire net to obtain an aqueous dispersion. (Examples 3 to 6) An aqueous dispersion was obtained in the same manner as in Example 1 except that the initial components, additional components, and additional components used in the polymerization were as shown in Table 1.

Comparative Example 1 In an autoclave similar to that in Example 1, 300 parts of water was used as an initial component, and a cation-modified polyvinyl alcohol (trade name: Kuraray C-506 manufactured by Kuraray Co., Ltd.) as a water-soluble polymer having a hydroxyl group was used. )
4 parts of a 20% aqueous solution (solid content conversion) of lauryl trimethyl ammonium chloride (trade name Cotamine 24P
2 parts of a 20% aqueous solution of Kao Corporation (solid content conversion),
0.8 part (in terms of solid content) of a 5% aqueous solution of 2,2′-azobis (2-amidinopropane) dihydrochloride (trade name: V-50, manufactured by Wako Pure Chemical Industries, Ltd.) was charged, and the gas phase was removed. After purging with nitrogen gas for 15 minutes, the temperature was raised to 65 ° C. Next, emulsion polymerization was performed at 70 ° C. while continuously adding the monomer components shown in Table 2 over 3 hours.
Aged for 2 hours. Then cool to 25 ° C,
1 part of a 10% aqueous solution of adipic dihydrazide as a polyfunctional hydrazine derivative (in terms of solid content, polyfunctional hydrazine having at least two hydrazino groups in one molecule based on equivalent (A) of carbonyl group in the aqueous dispersion) Ratio of equivalent (B) of hydrazino group in derivative (B) / (A) =
After adding 1) and stirring for about 1 hour, the solid content concentration was adjusted to 25% with water, and the mixture was filtered through a 200-mesh wire net to obtain an aqueous dispersion.

Comparative Example 2 In an autoclave similar to that in Example 1, 250 parts of water and lauryl trimethyl ammonium chloride (trade name: Cotamine 2) were used as initial components.
4P 3 parts of a 20% aqueous solution (manufactured by Kao Corporation) (in terms of solid content) of 2,2′-azobis (2-amidinopropane) dihydrochloride (trade name: V-50 manufactured by Wako Pure Chemical Industries, Ltd.) 5
% Aqueous solution (solid content conversion)
After purging with nitrogen gas for 5 minutes, the temperature was raised to 65 ° C. Next, emulsion polymerization was performed at 70 ° C. while continuously adding the monomer components shown in Table 2 over 3 hours.
Aged at ８０80 ° C. for another 2 hours. Thereafter, the mixture is cooled to 25 ° C., and 2 parts of a 10% aqueous solution of adipic dihydrazide as a polyfunctional hydrazine derivative (in terms of solid content, at least two hydrazino compounds in one molecule based on the equivalent (A) of carbonyl groups in the aqueous dispersion) are obtained. Of equivalent (B) of hydrazino group in polyfunctional hydrazine derivative having a group (B) /
(A) = 0.8) and stirred for about 1 hour,
The solid content concentration was adjusted to 25% with water, and the mixture was filtered through a 200-mesh wire net to obtain an aqueous dispersion.

Comparative Example 3 In an autoclave similar to that in Example 1, 250 parts of water and lauryltrimethylammonium chloride (trade name: Cotamine 2) were used as initial components.
4P 3 parts of a 20% aqueous solution (manufactured by Kao Corporation) (in terms of solid content) of 2,2′-azobis (2-amidinopropane) dihydrochloride (trade name: V-50 manufactured by Wako Pure Chemical Industries, Ltd.) 5
% Aqueous solution (solid content conversion)
After purging with nitrogen gas for 5 minutes, the temperature was raised to 65 ° C. Next, emulsion polymerization was performed at 70 ° C. while continuously adding the monomer components shown in Table 2 over 3 hours.
Aged at ８０80 ° C. for another 2 hours. Thereafter, the mixture is cooled to 25 ° C. and partially saponified polyvinyl alcohol (trade name Kuraray PVA-20) as a hydroxyl group-containing water-soluble polymer.
(3) 50 parts of a 20% aqueous solution of Kuraray Co., Ltd. (in terms of solid content) and 2 parts of a 10% aqueous solution of adipic dihydrazide as a polyfunctional hydrazine derivative (in terms of solid content, equivalent of carbonyl group in aqueous dispersion (A ) Of the equivalent (B) of hydrazino groups in the polyfunctional hydrazine derivative having at least two hydrazino groups in one molecule to (B) /
(A) = 0.8) and stirred for about 1 hour,
The solid content concentration was adjusted to 25% with water, and the mixture was filtered through a 200-mesh wire net to obtain an aqueous dispersion.

(Comparative Example 4) An aqueous dispersion was obtained in the same manner as in Example 1 except that the initial components, additional components and additional components used in the polymerization were as shown in Table 2.

(Measurement of Glass Transition Temperature) The aqueous dispersions obtained in Examples and Comparative Examples were vacuum-dried at 100 ° C. for 20 hours to form films. The dried film was subjected to AS using a differential scanning calorimeter (DSC: manufactured by DuPont).
The glass transition temperature was measured according to the TM method. The results are shown in Tables 1 and 2.

(Adjustment and Evaluation of Coating Material) Using the aqueous dispersions obtained in Examples and Comparative Examples, coating materials were prepared according to the following formulation. Formulation: Aqueous dispersion (in terms of solid content) 20 parts Water-soluble melamine 2 parts (trade name: Sumimar M-30W, manufactured by Sumitomo Chemical Co., Ltd.) Cationic oligomer type surfactant 1 part (trade name: ADEKA CATHIOACE PD- 50 Asahi Denka Kogyo Co., Ltd.) 78 parts of ion-exchanged water Each of the obtained coating materials was applied to a PET film whose surface was wiped off with methanol in advance, and the dry film thickness was 10 μm.
m after coating with a bar coder,
The specimen was dried in an atmosphere of 0 ° C. for 3 minutes to prepare a test piece. The performance of the obtained test piece was evaluated by the following method. Unless otherwise specified, printing on the test piece was performed using a dye-based inkjet printer (Seiko Epson Corporation).
PM-700C), black, yellow,
Printing was performed using four color inks of cyan and magenta.

1. Ink acceptability 1) Ink absorptivity One minute after the completion of printing, the printed surface was rubbed with a finger, and the state of the printed surface was visually observed.

：: Ink is not rubbed △: Ink is slightly rubbed ×: Ink is rubbed 2) Ink sticking property Printing of alphabet letters, leaving to stand for 10 minutes, dropping water drops on the letters, and drying water drops The state of the printing surface at that time was visually observed.

：: Characters can be clearly discriminated. Δ: Characters can be discriminated although there is bleeding. ×: Characters cannot be discriminated at all. 3) Clarity The sharpness of the print was visually observed.

：: clear image without bleeding or unevenness ：: slight bleeding or unevenness, but no problem in practical use x: remarkable bleeding Water resistance After printing alphabet letters and leaving them to stand for 10 minutes, drops of water were dropped on the letters, and one minute later, the printed portions were rubbed with absorbent cotton.

：: There is no detachment of the print surface. Δ: Some detachment of the print surface occurs. X: The print surface completely detaches. Transparency In accordance with JIS K6714, the haze value of the coating film was measured using an integral light transmittance measuring device and evaluated according to the following criteria.

：: Haze value is less than 10 ×: Haze value is 10 or more Blocking resistance A test piece was touched and evaluated.

：: No stickiness at all Δ: Slightly sticky, but no problem in practical use ×: Significant sticky feeling Curling Resistance A test piece was cut into a square of 10 cm 2, which was left on a flat table under an atmosphere of 25 ° C. and 65% humidity for 24 hours.
The evaluation was made based on the distance between the edge of the curled film and the table.

：: 5 mm or less Δ: 5 to 10 mm ×: 10 mm or more The results evaluated by the above evaluation methods are shown in Table 3 for Examples and Table 4 for Comparative Examples.

The aqueous dispersions shown in Examples 1 and 6 were excellent in ink receptivity such as ink absorbency, ink fixation and sharpness, water resistance, transparency, blocking resistance and curling resistance. A film can be formed.

The aqueous dispersion of Example 2 does not contain an ethylenically unsaturated monomer having a carbonyl group based on an ald group or a keto group in a radically polymerizable monomer component. Although the level is not as high as in Examples 1 and 6, the object of the present invention is sufficiently achieved.

The aqueous dispersion of Example 3 did not contain N-alkyl (meth) acrylamide in the monomer component, and was based on the equivalent (A) of the carbonyl group in the aqueous dispersion. Since the ratio (B) / (A) of the equivalent (B) of the hydrazino groups in the polyfunctional hydrazine derivative having at least two hydrazino groups in one molecule is less than 0.1, the ink absorption and the water resistance are improved. In Examples 1 and 6,
Although not at such a high level, the object of the present invention has been sufficiently achieved.

In the aqueous dispersion of Example 4, the amount of N-alkyl (meth) acrylamide was more than 50 parts by weight and the ratio (B) / 100 parts by weight relative to 100 parts by weight of the monomer component. Since (A) exceeds 5, the clarity, water resistance, and transparency are not as high as those in Examples 1 and 6, but the object of the present invention is sufficiently achieved.

In the aqueous dispersion of Example 5, the amount of the ethylenically unsaturated monomer having a carbonyl group based on an ald group or keto group was 20 parts by weight based on 100 parts by weight of the monomer component. And the glass transition temperature of the polymer obtained by polymerizing the monomer component is lower than −20 ° C., so that the ink absorption and the blocking resistance are at the level of Examples 1 and 6. However, the object of the present invention has been sufficiently achieved.

In contrast to these examples, the aqueous dispersion of Comparative Example 1 had an amount of the hydroxyl group-containing water-soluble polymer of less than 5 parts by weight based on 100 parts by weight of the monomer component. As a result, the ink receptivity such as ink absorbency, ink fixability, and sharpness is poor. Also, transparency tends to be poor.

Further, since the aqueous dispersion of Comparative Example 2 did not use a water-soluble polymer having a hydroxyl group, the ink receptivity such as ink absorption, ink fixation, and sharpness was poor. ing.

The aqueous dispersion of Comparative Example 3 was excellent
Despite developing ink absorption and ink fixation, without using hydroxyl group-containing water-soluble polymer during polymerization,
Since it is added after polymerization, excellent transparency cannot be exhibited. Also, the sharpness tends to be slightly inferior.

In the aqueous dispersion of Comparative Example 4, the amount of the hydroxyl group-containing water-soluble polymer was more than 500 parts by weight with respect to 100 parts by weight of the monomer component. In addition, the curl resistance is poor.

In Comparative Example 5, since the monomer component was not charged in the aqueous medium, the polymer obtained by polymerizing the monomer component was not included in the aqueous dispersion. As a result, sharpness, water resistance, and curl resistance are poor.

[0083]

[Table 1]

[Table 2]

[Table 3]

[Table 4]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 101/00 C08L 101/00 C09D 101/00 C09D 101/00 103/00 103/00 129/04 129/04 B 151/00 151/00 171/02 171/02 201/00 201/00 (72) Inventor Nobuo Kawahashi 2-11-24 Tsukiji, Chuo-ku, Tokyo Inside JSR Corporation

Claims (7)

[Claims] 1. A radical-polymerizable monomer component in an aqueous medium in the presence of 5 to 500 parts by weight of a hydroxyl group-containing water-soluble polymer per 100 parts by weight of a radically polymerizable monomer component. An aqueous dispersion containing a polymer obtained by polymerization. 2. The aqueous dispersion according to claim 1, wherein the radically polymerizable monomer component contains N-alkyl (meth) acrylamide. 3. The aqueous dispersion according to claim 1, wherein the radically polymerizable monomer component contains an ethylenically unsaturated monomer having a carbonyl group based on an ald group or a keto group. body. 4. The aqueous dispersion according to claim 3, wherein the aqueous dispersion further comprises a polyfunctional hydrazine derivative having at least two hydrazino groups in one molecule. 5. The aqueous dispersion according to claim 1, wherein the polymer has a glass transition temperature of −20 ° C. or higher. 6. A coating material for ink-jet recording, comprising the aqueous dispersion according to claim 1 as a main component. 7. An ink jet recording sheet obtained by applying the ink jet recording coating material according to claim 6.