JPH11152424A - Production of aqueous pigment dispersion and aqueous colored liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an aqueous pigment dispersion suitable for an aqueous colored liquid such as a water-color ink, aqueous printing liquid and water paint without using any steps of e.g. acid dipping and repeated dispersion in a short process step while saving the labor and energy. SOLUTION: This method is conducted by solving and dispersing either a water-soluble resin (A1) obtained by neutralizing an acid group in a hydrophobic resin (a1) having a functional group and acid group with a base, a pigment (B) and a cross-linking agent (C), or a water-soluble resin (A2) obtained by neutralizing an acid group in a hydrophobic resin (a2) having a self cross-linking functional group and acid group with a base and the pigment (B), into an aqueous medium to thus obtain the resultant aqueous dispersion, and by depositing a cross-linked product of water-soluble resin onto a periphery of the pigment (B). In this case, the water-soluble resins (A1) and (A2) are each obtained by neutralizing the acid group therein with the base of such an amount that the base may dissolve in the aqueous medium before the cross-linking step but then may deposit therein after the cross-linking step. The aqueous colored liquid includes the thus obtained aqueous pigment dispersion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an aqueous pigment dispersion useful for aqueous coloring liquids such as aqueous paints, aqueous inks, printing agents, color filters and aqueous recording liquids, and uses the aqueous pigment dispersions. Aqueous coloring liquid.

[0002]

2. Description of the Related Art From the viewpoint of pollution prevention and occupational health, the industry in which colorants such as paints and printing inks are used has a strong tendency to become water-based. In addition, stationery such as ballpoint pens and felt-tip pens used for recording information, and recording liquids such as printers and plotters represented by ink jets are becoming more and more water-soluble in terms of toxicity and hygiene.

[0003] The required performance of these uses, such as fine dispersions of pigments and long-term storage stability when preparing paints, inks and recording liquids, and water resistance, durability and robustness when formed into coatings, Japanese Patent Application Laid-Open No. 9-104834 discloses a method for producing an aqueous pigment dispersion capable of satisfying, for example, the redispersibility of the recording liquid against drying at the nozzle tip of an inkjet nozzle. This production method comprises kneading a resin having both a carboxyl group and a functional group capable of reacting with a crosslinking agent and / or a functional group capable of self-crosslinking, and a pigment to form a finely dispersed aqueous dispersion, The resin is made hydrophobic by making the pH neutral or acidic with an acidic compound to strongly adhere to the pigment (acid precipitation). Then, the carboxyl group is neutralized again with a basic compound and redispersed in water. And a novel aqueous pigment dispersion produced by crosslinking a resin at an arbitrary time.

[0004]

However, as a method for producing the above-mentioned aqueous pigment dispersion, after producing the aqueous dispersion,
It is manufactured through the steps of acid precipitation and redispersion. Therefore, there is a problem that the production process is longer than that of a normal aqueous pigment dispersion, and energy and labor are required more than necessary.

[0005]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, first, a hydrophobic resin having a crosslinkable functional group and an acidic group, or a self-crosslinkable functional group. A hydrophobic resin having a group and an acidic group is dissolved in an aqueous medium at a stage before crosslinking, but after crosslinking, the acidic group is neutralized with an amount of base that precipitates in the aqueous medium to form a water-soluble resin, After dissolving and dispersing the water-soluble resin, the pigment, and the crosslinking agent as necessary in an aqueous medium, the water-soluble resin is dissolved, and an aqueous dispersion in which the pigment is dispersed is obtained. The cross-linking reaction of the water-soluble resin causes the cross-linked product of the water-soluble resin to precipitate around the pigment, so that the cross-linked product of the water-soluble resin adheres to the surface of the pigment without the need for acid precipitation and redispersion. Aqueous pigment dispersion can be manufactured at the same time. 20 wt% or less of that aqueous dispersion is preferred, acrylic resin as the hydrophobic resin having a carboxyl group, for example an acid value 30~250KOHmg
It has been found that a resin having a resin solid content of 1 g is preferable, and that the aqueous pigment dispersion thus obtained is preferably used for an aqueous coloring liquid such as an aqueous ink, an aqueous recording liquid, or an aqueous paint. It was completed.

That is, the present invention provides: Hydrophobic resin having a crosslinkable functional group and an acidic group (a
1) A water-soluble resin (A) obtained by neutralizing an acidic group in
1) After dissolving and dispersing the pigment (B) and the crosslinking agent (C) in an aqueous medium to obtain an aqueous dispersion (I), a crosslinking functional group in the water-soluble resin (A1) and a crosslinking agent ( C) to form a water-soluble resin (A) around the pigment (B).
1) a method for producing an aqueous pigment dispersion for precipitating a crosslinked product,
Alternatively, a water-soluble resin (A2) obtained by neutralizing an acidic group in a hydrophobic resin (a2) having a self-crosslinkable functional group and an acidic group with a base and a pigment (B) are dissolved and dispersed in an aqueous medium. Aqueous pigment dispersion (II), which is then subjected to a self-crosslinking reaction of the water-soluble resin (A2) to precipitate a self-crosslinked product of the water-soluble resin (A2) around the pigment (B). And the water-soluble resin (A1),
(A2) is a water-soluble resin which is dissolved in an aqueous medium at the stage before crosslinking, but is a water-soluble resin obtained by neutralizing acidic groups with an amount of base which precipitates in the aqueous medium after crosslinking. A method for producing a pigment dispersion,

[0007] 2. By crosslinking the aqueous dispersion (I) or (II) having a non-volatile content of 20% by weight or less, the crosslinked product of the water-soluble resin (A1) or the self-dispersion of the water-soluble resin (A2) around the pigment (B). The production method according to the above 1, wherein the crosslinked product is precipitated,

[0008] 3. 3. The method according to the above 1 or 2, wherein the hydrophobic resin (a1) or the hydrophobic resin (a2) is an acrylic resin having a carboxyl group.

4. The production method according to the above 1, 2, or 3, wherein the hydrophobic resin (a1) or the hydrophobic resin (a2) is a resin having an acid value of 30 to 250 KOHmg / resin solid content of 1 g,

[0010] 5. Hydrophobic resin (a1) is a resin having a carboxyl group as a crosslinkable functional group and an acidic group,
Any one of the above 1-4, wherein the crosslinking agent (C) is a compound having an amino group or a compound having two or more epoxy groups.
Manufacturing method described in

6. The method according to any one of the above items 1 to 4, wherein the hydrophobic resin (a2) is a resin having a carboxyl group and an epoxy group,

7. The production method according to any one of the above 1 to 6, wherein the base used for neutralization of the hydrophobic resin (a1) or the hydrophobic resin (a2) is a tertiary amine;

8. An aqueous coloring liquid comprising an aqueous pigment dispersion obtained by the production method according to any one of claims 1 to 7, and

9. The aqueous recording liquid according to claim 8, which is an aqueous ink, an aqueous recording liquid, or an aqueous paint.

The acid value in the present invention is represented by the amount of mg of potassium hydroxide necessary to neutralize 1 g of resin solids.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Among the production methods of the present invention, a method using an aqueous dispersion (I) basically comprises the following production steps.

A water-soluble resin (A1) which is made water-soluble by neutralizing a part or all of the acidic groups in the hydrophobic resin (a1) having a crosslinkable functional group and an acidic group with a base, (B) is dissolved in an aqueous medium by dissolving the water-soluble resin (A1), dispersing the pigment (B), and further adding a cross-linking agent (C) before or after the pigment dispersion to form an aqueous dispersion. Produce body (I). In this case, the crosslinking agent (C) may be dissolved or dispersed in the aqueous medium. Next, while maintaining the dispersion of the pigment (B) in the aqueous medium, energy is applied to the aqueous dispersion (I), whereby the crosslinkable functional group in the water-soluble resin (A1) and the crosslinker (C) are formed. Water-soluble resin (A)
The crosslinked product of 1) is precipitated. The precipitated crosslinked product adheres to the pigment surface.

The method using the aqueous dispersion (II) of the production method of the present invention basically comprises the following production steps.

A water-soluble resin (A2) which has been rendered water-soluble by neutralizing a part or all of the acidic groups in the hydrophobic resin (a2) having a self-crosslinkable functional group and an acidic group with a base;
The water-soluble resin (A2) is dissolved in an aqueous medium with the pigment (B), and the pigment (B) is dispersed to produce an aqueous dispersion (II). Next, while maintaining the dispersion of the pigment (B) in the aqueous medium, the energy is applied to the aqueous dispersion (II), whereby the self-crosslinkable functional groups in the water-soluble resin (A2) are self-crosslinked. A crosslinked product of the water-soluble resin (A2) is deposited on the surface. The precipitated crosslinked product adheres to the pigment surface.

The water-soluble resin (A
The precipitation of 1) and (A2) occurs when the solubility of the resin in water decreases due to an increase in the molecular weight of the resin, a decrease in the polar group in the resin due to a crosslinking reaction, and the like. Further, a crosslinking reaction of the resin proceeds on the surface of the pigment, a network structure is formed, and storage stability and water resistance of various paints and inks increase.

The amount of the base used for neutralizing the acidic groups in the hydrophobic resins (a1) and (a2) to make the resin water-soluble is such that the neutralized resin is in an aqueous medium before the crosslinking. It is an amount that dissolves in the aqueous medium, but causes precipitation of the resin dissolved in the aqueous medium after crosslinking. Specifically, in a system in which the pigment (B) is removed from the aqueous dispersion (I) or (II), the degree of neutralization of the hydrophobic resin (a1) or (a2) with a base is changed, and then the crosslinking is performed. The maximum neutralization ratio at which a crosslinked product is deposited is determined. The amount of base before and after this maximum neutralization rate is the required amount of base. In this case, since the pigment is not present in the system, even if the neutralization ratio is greater than the neutralization ratio that has been precipitated (in a state of being water-solubilized even when crosslinked), the solubility of water in the water due to adsorption of the crosslinked product to the pigment occurs. Then, the precipitation of the crosslinked product occurs sufficiently.

Under the conditions where the crosslinked product does not precipitate,
Networking of the resin on the pigment surface does not occur, and storage stability deteriorates. In addition, when crosslinking is performed under conditions that do not make the resin water-soluble, aggregation of the pigment due to crosslinking of the insolubilized resin does not occur, and networking of the resin on the pigment surface does not occur, resulting in poor storage stability.

The neutralization ratio required to precipitate the water-soluble resin by crosslinking depends on the acid value of the hydrophobic resins (a1) and (a2). In addition, a high acid value resin needs to have a low neutralization ratio, and a cross-linking reaction of these resins makes it possible to precipitate a cross-linked product. Here, the low acid value resin has relatively good water resistance, but the water resistance is further improved by crosslinking. The high acid value resin can be made hydrophilic on the surface of the pigment by adding a small amount of a base after the crosslinking reaction. These make it possible to produce an aqueous pigment dispersion that can be used in a wide range of applications, from coating applications requiring water resistance to recording liquids requiring redispersibility by making the pigment surface hydrophilic, from a coating application requiring water resistance.

The hydrophobic resins (a1) and (a2) used in the production method of the present invention have an acidic group and a crosslinkable functional group or a self-crosslinkable functional group, and a part of the acidic group or Any resin can be used as long as it can be made water-soluble by neutralizing all with a base.
For example, a vinyl resin, a polyester resin, a polyurethane resin, an epoxy resin, a rosin-modified resin, and the like can be given. Among these, vinyl resins, especially acrylic resins, are preferable from the viewpoint of easy introduction of an acidic group or easy introduction of a crosslinkable functional group or a self-crosslinkable functional group.

The vinyl resin used in the production method of the present invention includes, for example, (meth) acrylic acid ester polymer, (meth) acrylic acid ester-styrene copolymer, styrene- (anhydride) maleic acid copolymer And fluorine-containing acrylic copolymers. Examples of the polyester resin include a saturated polyester resin, an unsaturated polyester resin, and an alkyd resin. These resins must contain an acidic group for imparting appropriate water solubility, and have a crosslinkable functional group or a self-crosslinkable functional group in order to cause precipitation by crosslinking of the resin. is there.

The acidic group is a group that is neutralized by a basic compound and includes, for example, a carboxyl group, a sulfonic acid group, a phosphoric acid group, etc. Among them, a carboxyl group is particularly preferred.

The crosslinkable functional group is a functional group capable of forming a crosslink by reacting with a crosslinker. The self-crosslinkable functional group is a functional group capable of forming a crosslink without a crosslinker (hereinafter referred to as “self-crosslinkable group”). Abbreviated as "crosslinkable functional group (1)") and a combination of two or more functional groups capable of forming a crosslinking bond without a crosslinking agent (hereinafter abbreviated as "self-crosslinkable functional group (2)"). is there.

Examples of the crosslinkable functional group include a carboxyl group, a hydroxyl group, a tertiary amino group, a blocked isocyanate group, an epoxy group, and a 1,3-dioxolan-2-one-4-yl group. Among them, a carboxyl group, a hydroxyl group, and an epoxy group are preferable because of high reactivity and easy introduction into a resin.

Next, typical examples of combinations of a crosslinkable functional group and a crosslinking agent will be shown below. When the crosslinkable functional group is a carboxyl group, the crosslinking agent may be an amino resin, a compound having two or more epoxy groups in one molecule, a 1,3-dioxolan-2-one-4-yl group in one molecule ( And the like having two or more cyclocarbonate groups).

When the crosslinkable functional group is a hydroxyl group, examples of the crosslinking agent include amino resins, polyisocyanate compounds, and blocked polyisocyanate compounds.

When the crosslinkable functional group is a tertiary amino group,
Examples of the crosslinking agent include a compound having two or more epoxy groups in one molecule, a compound having two or more 1,3-dioxolan-2-one-4-yl groups in one molecule, and the like.

When the crosslinkable functional group is a blocked isocyanate group, examples of the crosslinking agent include compounds having two or more hydroxyl groups in one molecule.

When the crosslinkable functional group is an epoxy group or 1,3
In the case of -dioxolan-2-one-4-yl group, examples of the crosslinking agent include a compound having two or more carboxyl groups in one molecule, a polyamine compound, a polymercapto compound and the like.

Examples of the self-crosslinkable functional group (1) include a radically polymerizable unsaturated group and a hydrolyzable alkoxysilane group. For the purpose of reinforcing the self-crosslinking property, a compound having two or more radically polymerizable unsaturated groups and a compound having two or more hydrolyzable alkoxysilane groups can be partially used in combination.

Examples of the hydrolyzable alkoxysilane group include methacryloxypropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (β-methoxyethoxy) silane and the like.

The self-crosslinkable functional group (2) has two or more types of functional groups capable of reacting in one molecule. The combination of such functional groups includes, for example, a carboxyl group and an epoxy group, Carboxyl group and 1,3-dioxolan-2-one-4-yl group, hydroxyl group and blocked isocyanate group, hydroxyl group and N-alkoxymethylamide group, hydroxyl group and hydrolyzable alkoxysilane group,
Examples include a combination of an amino group and an epoxy group. Among these, a combination of a carboxyl group and an epoxy group is particularly preferable because of its reactivity and easy introduction into a resin.

Next, a specific method for introducing a crosslinkable functional group or a self-crosslinkable functional group into a resin will be described.

The vinyl resin in which the acidic group and the crosslinkable functional group are carboxyl groups can be easily produced, for example, by a method of copolymerizing a polymerizable monomer composition containing a vinyl monomer having a carboxyl group. . Examples of the vinyl monomer having a carboxyl group include acrylic acid, methacrylic acid, crotonic acid, fumaric acid, itaconic acid, and maleic acid (anhydride); monoalkyl maleates such as monobutyl maleate; itacone such as monobutyl itaconate Monoalkyl acid and the like.

Examples of the polymerizable monomer other than the vinyl monomer having a carboxyl group contained in the polymerizable monomer composition include styrene, vinyl toluene, α-
Aromatic vinyl monomers such as methylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate,
n-butyl (meth) acrylate, isobutyl (meth)
Acrylate, tert-butyl (meth) acrylate, isoamyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, butoxymethyl (Meth) acrylates such as (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, benzyl (meth) acrylate, cetyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, and isobornyl (meth) acrylate; vinyl acetate; Vinyl esters such as vinyl benzoate, vinyl versatate and vinyl propionate; polymerizable nitriles such as (meth) acrylonitrile; vinyl fluoride; Fluoride, tetrafluoroethylene, vinyl monomers having such fluorine atoms hexafluoropropylene or chlorotrifluoroethylene; diethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, N-
Tertiary amino group-containing monomers such as vinylimidazole and N-vinylcarbazole; 2- (2'-hydroxy-5-methacryloyloxyethylphenyl) -2H-
Benzotriazole, 2-hydroxy-4- (2-methacryloyloxyethoxy) benzophenone, 1,2,2
Monomers having ultraviolet absorbing or antioxidant properties, such as 2,6,6-pentamethyl-4-piperidyl methacrylate; N-vinylpyrrolidone, glycidyl (meth) acrylate, 1,3-dioxolan-2-one-4-ylmethyl (Meth) acrylate, 1,3-dioxolan-2-one-4-ylmethylvinylether, diacetoneacrylamide, N-methylolacrylamide, N
-Functional group-containing monomers such as N-alkoxymethyl (meth) acrylamides such as butoxymethyl (meth) acrylamide; and phosphoric acid groups such as 2-phosphooxyethyl (meth) acrylate and 4-phosphooxybutyl (meth) acrylate Monomers: macromonomers having one polymerizable unsaturated group at the molecular terminal.

The polymerization method of the polymerizable monomer composition is as follows:
Various known polymerization methods such as suspension polymerization, emulsion polymerization, bulk polymerization, and solution polymerization can be used, but solution polymerization is preferable because it is simple. As the polymerization initiator, known peroxides and azo compounds can be used.

The vinyl resin having a carboxyl group includes, for example, a vinyl resin having a hydroxyl group, maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride,
It can also be produced by a method in which an acid anhydride such as hexahydrophthalic anhydride or trimellitic anhydride is subjected to an addition reaction.

The vinyl resin having a hydroxyl group and a carboxyl group can be easily produced, for example, by using a vinyl monomer having a hydroxyl group in the production of the above-mentioned vinyl resin having a carboxyl group. . Examples of the vinyl monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate and 2-hydroxyethyl (meth) acrylate.
Hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, "Placcel FM
(Meth) acrylic monomers, polyethylene glycol mono (meth) acrylate monomers, and polypropylene glycol mono (meth) to which a lactone compound represented by "-2" or "Placcel FA-2" (manufactured by Daicel Chemical Industries, Ltd.) has been added. Acrylate monomers, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether and the like can be mentioned.

The vinyl resin having a tertiary amino group and a carboxyl group may be used, for example, when the above-mentioned vinyl resin having a carboxyl group is used together with a vinyl monomer having a tertiary amino group. Can be manufactured more easily. Examples of the polymerizable monomer having a tertiary amino group include diethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and the like.

The vinyl resin having a blocked isocyanate group and a carboxyl group can be easily prepared, for example, by using a polymerizable monomer having a blocked isocyanate group in producing the above-mentioned vinyl resin having a carboxyl group. Can be manufactured.

The polymerizable monomer having a blocked isocyanate group can be easily obtained by, for example, adding a known blocking agent to a polymerizable monomer having an isocyanate group such as 2-methacryloyloxyethyl isocyanate. Alternatively, it can be easily produced by adding a compound having an isocyanate group and a blocked isocyanate group to the above-mentioned vinyl resin having a hydroxyl group and a carboxyl group by an addition reaction.

The compound having an isocyanate group and a blocked isocyanate group can be easily obtained, for example, by subjecting a diisocyanate compound and a known blocking agent to an addition reaction at a molar ratio of about 1: 1.

The vinyl resin having an epoxy group and a carboxyl group can be easily produced, for example, by using a polymerizable monomer having an epoxy group in the production of the above-mentioned vinyl resin having a carboxyl group. Can be. Examples of the polymerizable monomer having an epoxy group include glycidyl (meth) acrylate and a (meth) acrylate monomer having an alicyclic epoxy group.

The vinyl resin having a 1,3-dioxolan-2-one-4-yl group and a carboxyl group can be used, for example, in producing the above-mentioned vinyl resin having a carboxyl group. It can be easily produced by using a polymerizable monomer having a -2-on-4-yl group in combination. 1,3-dioxolan-2-
Examples of the polymerizable monomer having an on-4-yl group include 1,3-dioxolan-2-one-4-ylmethyl (meth) acrylate and 1,3-dioxolan-2-
On-4-ylmethyl vinyl ether and the like can be mentioned.

The vinyl resin having a radically polymerizable unsaturated group as the self-crosslinking agent functional group (1) and further having a carboxyl group as an acidic group includes, for example, a vinyl resin having an epoxy group and a carboxyl group. A method in which a radical-polymerizable unsaturated group-containing monomer having a primary or secondary amino group is subjected to an addition reaction. A vinyl resin having a hydroxyl group and a carboxyl group has an isocyanate group such as 2-methacryloyloxyethyl isocyanate. A method in which radical-polymerizable unsaturated group-containing monomers or an anhydride having a radical-polymerizable unsaturated group such as maleic anhydride is subjected to an addition reaction, and a radical-polymerizable unsaturated resin having an epoxy group is added to a vinyl resin having a carboxyl group. A method of subjecting a saturated group-containing monomer to an addition reaction,
It can be easily manufactured by the above method.

The vinyl resin having a hydrolyzable alkoxysilane group as the self-crosslinkable functional group (1) and a carboxyl group as an acidic group is, for example, a vinyl resin having a carboxyl group as described above. In this case, a polymerizable monomer having a hydrolyzable alkoxysilane group such as methacryloxypropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, or vinyltris (β-methoxyethoxy) silane is easily used in combination. Can be manufactured.

The vinyl resin having a self-crosslinkable functional group (2) and a carboxyl group may be used, for example, when the above-mentioned vinyl resin having a carboxyl group is used in combination with a polymerizable monomer having an epoxy group. A polymerizable monomer having a 1,3-dioxolan-2-one-4-yl group, a polymerizable monomer having a hydroxyl group and a polymerizable monomer having a blocked isocyanate group, and a polymerizable monomer having a hydroxyl group It can be easily produced by using together with a polymerizable monomer having an N-alkoxymethylamide group.

The polyester resin in which the acidic group and the crosslinkable functional group are carboxyl groups can be prepared, for example, by mixing a carboxyl group-containing compound and a hydroxyl group-containing compound by a known method such as a melting method and a solvent method so that the carboxyl group remains. It can be produced by performing a dehydration condensation reaction by a method.

Examples of the polyester resin include those obtained by appropriately selecting a compound having a carboxyl group such as a monobasic acid or a polybasic acid and a compound having a hydroxyl group such as a diol or a polyol and subjecting them to dehydration condensation. Further, an alkyd resin using oils and fats or fatty acids is used.

The carboxyl group of the polyester resin used in the production method of the present invention is mainly an unreacted carboxyl group derived from a polybasic acid of dibasic acid or more constituting the polyester resin.

Examples of polybasic acids include adipic acid,
(Anhydrous) succinic acid, sebacic acid, dimer acid, (anhydrous)
Maleic acid, (phthalic anhydride), isophthalic acid, terephthalic acid, tetrahydro (phthalic anhydride), hexahydro (phthalic anhydride), hexahydroterephthalic acid, 2,6
-Naphthalenedicarboxylic acid, trimellitic acid (anhydride),
(Anhydrous) pyromellitic acid and the like.

Compounds having a carboxyl group that can be used other than polybasic acids include, for example, lower alkyl esters of acids such as dimethyl terephthalate; benzoic acid, p-
Monobasic acids such as tertiary butyl benzoic acid, rosin, hydrogenated rosin; fatty acids and fats and oils; macromonomers having one or two carboxyl groups at molecular terminals;
Sodium sulfoisophthalic acid and its dimethyl esters.

As the compound having a hydroxyl group, for example,
Ethylene glycol, neopentyl glycol, propylene glycol, diethylene glycol, dipropylene glycol, 2-methyl-1,3-propanediol,
2,2-diethyl-1,3-propanediol, 1,4
-Butanediol, 1,3-propanediol, 1,6
-Hexanediol, 1,4-cyclohexanedimethanol, 1,5-pentanediol, an alkylene oxide adduct of bisphenol A, hydrogenated bisphenol A,
Alkylene oxide adduct of hydrogenated bisphenol A,
Polyethylene glycol, polypropylene glycol,
Diols such as polytetramethylene glycol; polyols such as glycerin, trimethylolpropane, trimethylolethane, diglycerin, pentaerythritol, and trishydroxyethyl isocyanurate;
Monoglycidyl compounds such as "Kajura E-10" (glycidyl ester of a synthetic fatty acid manufactured by Shell Chemical Industry Co., Ltd.), macromonomers having two hydroxyl groups at one molecular end, and the like.

In synthesizing a polyester resin,
Castor oil, hydroxyl-containing fatty acids or oils such as 12-hydroxystearic acid; dimethylolpropionic acid,
Compounds having a carboxyl group and a hydroxyl group, such as p-hydroxybenzoic acid and ε-caprolactone, can also be used.

Further, a part of the dibasic acid can be replaced with a diisocyanate compound.

The polyester resin having a carboxyl group can be obtained by adding a maleic anhydride, a phthalic anhydride, a tetrahydrophthalic anhydride to a polyester resin having a hydroxyl group.
It can also be produced by a method in which an acid anhydride such as hexahydrophthalic anhydride or trimellitic anhydride is subjected to an addition reaction.

The polyester resin having a hydroxyl group and a carboxyl group can be easily produced, for example, by subjecting the polyester resin to a dehydration condensation reaction according to a known method so that the hydroxyl group and the carboxyl group remain. .

The polyester resin having a tertiary amino group and a carboxyl group includes, for example, a compound having a tertiary amino group and a hydroxyl group such as triethanolamine, N-methyldiethanolamine and N, N-dimethylethanolamine. It can be easily produced by using it as an alcohol component when producing a polyester resin.

A polyester resin having a radically polymerizable unsaturated group as the self-crosslinkable functional group (1) and a carboxyl group as the acidic group may be obtained, for example, by adding 2-methacryloyloxyethyl isocyanate to a polyester resin having a hydroxyl group and a carboxyl group. A radical polymerizable unsaturated group-containing monomer having an isocyanate group such as, or a method of performing an addition reaction with an anhydride having a radical polymerizable unsaturated group such as maleic anhydride, an epoxy group is added to a polyester resin having a carboxyl group. It can be easily produced by a method in which a polymerizable monomer having an addition reaction is carried out, a method of synthesizing a polyester resin using a monomer having a radically polymerizable unsaturated group such as maleic anhydride as an acid component, and the like.

The polyurethane resin having a carboxyl group used in the production method of the present invention includes, for example, a polyol component containing a compound having a carboxyl group and a hydroxyl group such as dimethylolpropionic acid as a component for introducing a carboxyl group; It can be easily produced by reacting with a polyisocyanate component.

As the polyol component, in addition to the diol components listed in the method for producing a polyester resin, a polyol compound having three or more functional groups can be used, if necessary.

Examples of the polyisocyanate component include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, phenylene diisocyanate, 1,5-naphthalene diisocyanate, and meta-isocyanate. Xylylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated 4,4′-diphenylmethane diisocyanate, hydrogenated meta-xylylene diisocyanate, crude 4,
In addition to diisocyanate compounds such as 4'-diphenylmethane diisocyanate, polyisocyanate compounds such as polymethylene polyphenylisocyanate can be used.

The production of the polyurethane resin may be performed according to a conventional method. For example, the addition reaction is preferably performed at room temperature or at a temperature of about 40 to 100 ° C. in an inert organic solvent solution that does not react with the isocyanate group. At that time, a known catalyst such as dibutyltin dilaurate may be used.

In the reaction system for producing the polyurethane resin, known chain extenders such as diamines, polyamines, N-alkyl dialkanolamines such as N-methyldiethanolamine; and dihydrazide compounds can be used.

A polyurethane resin having a hydroxyl group and a carboxyl group can be easily produced, for example, by reacting a polyurethane resin at a ratio of more hydroxyl groups than isocyanate groups when producing the polyurethane resin. Alternatively, it can also be easily produced by subjecting a polyisocyanate resin having a carboxyl group and a terminal isocyanate group to an addition reaction with a compound having two or more hydroxyl groups in one molecule.

The polyurethane resin having a tertiary amino group and a carboxyl group can be easily produced, for example, by using an N-alkyldialkanolamine such as N-methyldiethanolamine as a part of the polyol component. .

The polyurethane resin having a blocked isocyanate group and a carboxyl group can be easily produced, for example, by adding a known blocking agent to a polyisocyanate resin having a carboxyl group and a terminal isocyanate group. .

The polyurethane resin having an epoxy group and a carboxyl group can be easily produced, for example, by subjecting a polyisocyanate resin having a carboxyl group and a terminal isocyanate group to an addition reaction of a compound having a hydroxyl group and an epoxy group. Can be.

Examples of the compound having a hydroxyl group and an epoxy group include glycidol, glycerin diglycidyl ether, trimethylolpropane diglycidyl ether, and diglycidyl ether of bisphenol A.

Polyurethane resins having a radically polymerizable unsaturated group as the self-crosslinkable functional group (1) and a carboxyl group as the acidic group include, for example, a polymer having a hydroxyl group as described above in a polyisocyanate resin having a terminal isocyanate group. Monomer, glycerol mono (meth) acrylate, trimethylolpropanedi (meth)
It can be easily produced by, for example, a method in which a compound having a hydroxyl group and a radical polymerizable unsaturated group such as acrylate and pentaerythritol triacrylate is subjected to an addition reaction.

Polyurethane resins having a hydrolyzable alkoxysilane group as the self-crosslinkable functional group (1) and a carboxyl group as the acidic group include, for example, γ-mercaptopropyltrimethoxysilane as a polyisocyanate resin having a terminal isocyanate group. Easily produced by a method such as an addition reaction of a silane coupling agent having an active hydrogen capable of reacting with an isocyanate group such as γ-mercaptopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, and γ-aminopropyltriethoxysilane. can do.

The amount of the acidic group in the hydrophobic resins (a1) and (a2) having an acidic group and a crosslinkable functional group or a self-crosslinkable functional group is such that the acid value is in the range of 30 to 300 KOH mg / g. Is preferable, and an amount which is in the range of 50 to 250 KOH mg / g is more preferable. If the acid value exceeds 300 KOH mg / g, the hydrophilicity becomes too high, so that even if crosslinked, the resin tends to become water-soluble in water. If the acid value is lower than 30 KOH mg / g, the resin becomes water-soluble. Care must be taken when using it, as it tends to be difficult to convert.

The hydrophobic resin (a1) used in the present invention,
When (a2) is a vinyl resin or a polyurethane resin, those having a number average molecular weight in the range of 3,000 to 20,000 are preferred. When the number average molecular weight is lower than 3,000, the material to be coated tends to become brittle when used as a coating agent, and when the number average molecular weight is higher than 20,000, a fine pigment dispersion is formed. Care must be taken when using it because it tends to be difficult to obtain.

The hydrophobic resin (a1) used in the present invention,
When (a2) is a polyester resin, the molecular weight is
In most cases, the polyester resin is of a branched type, so that unlike the case of a linear vinyl resin or the like, the weight average molecular weight is large even if the number average molecular weight is small, so that the film has sufficient toughness as a coating. Therefore, the number average molecular weight of the polyester resin is preferably in the range of 1,000 to 20,000, and the weight average molecular weight is preferably 5,0.
Those in the range of 00 to 100,000 are preferred.

As the pigment (B) used in the present invention, inorganic pigments and extender pigments can be used, but carbon black and organic pigments are particularly preferred.

Representative organic pigments include, for example, quinacridone pigments, quinacridone quinone pigments,
Dioxazine pigments, phthalocyanine pigments, anthrapyrimidine pigments, anthanthrone pigments, indanthrone pigments, flavanthrone pigments, perylene pigments,
Diketopyrrolopyrrole pigments, perinone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, isoindoline pigments, isoindolinone pigments, azomethine pigments or azo pigments, etc. Can be

As carbon black, neutral,
Acidic and basic carbons are exemplified.

The pigment (B) used in the present invention may be a powder or a solidified one, or
Pigments dispersed in water, such as aqueous slurries and press cakes, can also be used.

The base used in the present invention includes, for example,
Examples include inorganic bases such as sodium hydroxide and potassium hydroxide, and organic amines such as ammonia, triethylamine, tributylamine, monoethanolamine, dimethylethanolamine, diisopropanolamine, triethanolamine and morpholine. Further, preferred bases are tertiary amines such as triethylamine, tributylamine, dimethylaminoethanol and triethanolamine.

Next, an example of the manufacturing process in the present invention will be described sequentially.

First, the hydrophobic resins (a1) and (a2)
Before the crosslinking, the base is dissolved in the aqueous medium, but after the crosslinking, the amount of the base that precipitates in the aqueous medium is determined. Specifically, a system in which the pigment (B) is removed from the aqueous dispersions (I) and (II), for example, a hydrophobic resin (a1) and a crosslinking agent (C)
In a system comprising a base and water and, if necessary, a water-soluble organic solvent, or a system comprising a hydrophobic resin (a2), a base and water, and optionally a water-soluble organic solvent, the amount of the base is changed to obtain an acidic solution. Prepare ones with different neutralization rates of the groups, cross-link each, observe the state of precipitation of cross-linked products by cross-linking, dissolve in aqueous medium at the stage before cross-linking, but in aqueous medium after cross-linking The amount of the base that precipitates on the surface is determined. Usually, the maximum amount of base from which a crosslinked product has been deposited is employed.

Next, in a normal case, the water-soluble resin (A1), which is neutralized and water-soluble by the amount of the base under the above conditions,
The pigment (B) is dispersed in the aqueous solution of (A2). In this case, the crosslinking agent (C) is added before or after the pigment is dispersed. At that time, it is more preferable before the dispersion because the probability that the crosslinking agent (C) exists on the surface of the pigment (B) is high.

Further, it is preferable to add a small amount of a water-soluble organic solvent at the time of dispersing the pigment (B) since foaming is reduced and the wettability of the resin to the pigment (B) is improved.

To disperse the pigment (B), first, a powdery or solid pigment is mixed with the water-soluble resin (A1) or (A
Along with the aqueous solution of 2), fine dispersion is carried out using a known disperser such as a ball mill, a sand grinder, a colloid mill, a bead mill such as a Dyno mill.

The water-soluble organic solvent used above is not particularly limited, but has good solubility in the water-soluble resins (A1) and (A2) and has no problem in the synthesis of the water-soluble resin.
Those having a higher vapor pressure than water and easy to remove the solvent are preferred.
Examples of such a water-soluble organic solvent include acetone, methyl ethyl ketone, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, ethyl acetate, tetrahydrofuran and the like.

In addition to the above, for the purpose of assisting the dispersion of the pigment (B), a pigment dispersant or a wetting agent may be used in combination within a range that does not deteriorate the performance of the intended use.

When or after dispersing the pigment (B), a substance other than the pigment (B), for example, a dye,
Antioxidants, ultraviolet absorbers, curing catalysts for coating binders, rust inhibitors, fragrances, chemicals, and the like can also be added.

The ratio between the water-soluble resins (A1) and (A2) and the pigment (B) is based on 100 parts by weight of the pigment (B).
The water-soluble resin preferably has a solid content of 5 to 300 parts by weight, particularly preferably 10 to 200 parts by weight. When the proportion of the resin solids is less than 5 parts by weight, the pigment tends to be difficult to disperse sufficiently finely, and when the proportion is more than 300 parts by weight, the proportion of the pigment in the dispersion decreases and the water-based paint When used in inks and inks, recording liquids, etc., there is a tendency that there is no room for formulation design.

The amount of the water-soluble organic solvent is preferably 200 parts by weight or less, more preferably 5 to 100 parts by weight, based on 100 parts by weight of the pigment.

The water-soluble resin (A1), (A
The crosslinking of 2) is carried out by dissolving the water-soluble resin and dispersing the pigment (B) in an aqueous medium composed of water and, if necessary, a water-soluble organic solvent, etc., to form aqueous dispersions (I) and (II). After that, heating is performed under normal pressure or under pressure, irradiation with energy rays, or the like. In this case, crosslinking may be performed in the presence of a catalyst or a polymerization initiator. When the non-volatile content in the aqueous dispersions (I) and (II) is high, the distance between the dispersed pigments is short and the cross-linking causes the pigments to aggregate. Therefore, it is preferably prepared by adding water or the like in advance, and is preferably in a range of 20% by weight or less, more preferably in a range of 2 to 10% by weight.

The self-crosslinking with a carboxyl group and an epoxy group, the self-crosslinking with a hydroxyl group and an N-alkoxymethylamide group, and the self-crosslinking with a hydrolyzable alkoxysilane group are performed, for example, by heating at 50 to 150 ° C. under normal pressure or under pressure. Crosslinking. At this time, it is also recommended to use a catalyst.

In the case of self-crosslinking by a radically polymerizable unsaturated group, a water-soluble polymerization initiator such as potassium persulfate and ammonium persulfate is added, and the polymerization is further changed to a redox system at 50 to 90 ° C. Crosslinking can take place at moderate temperatures.

On the other hand, the crosslinking using the crosslinking agent (C)
Crosslinking by heating at 50 to 100 ° C. under normal pressure is preferable, but crosslinking may be performed at about 100 to 150 ° C. under pressure in some cases. At this time, it is also recommended to use a catalyst.

As such a crosslinking agent, a water-soluble or water-dispersible one is preferable, and examples thereof include an amino resin and a compound having two or more epoxy groups in a molecule.

Typical amino resins include melamine resins, urea resins, benzoguanamine resins, and the like. Examples of the amino resins include those that have been methylolated with formaldehyde and then etherified with methanol or butanol.

Examples of the compound having two or more epoxy groups include a vinyl resin obtained by copolymerizing a polymerizable monomer having an epoxy group such as various polyglycidyl ethers, polyglycidyl esters, and glycidyl methacrylate, which is called an epoxy resin. And the like.

The mixing ratio of the water-soluble resins (A1) and (A2) and the crosslinking agent (C) is generally expressed by the weight ratio of solids,
The range of 30:70 to 95: 5 is preferable, and 40:60 to
A range of 90:10 is particularly preferred.

Further, the aqueous pigment dispersion obtained above may be concentrated to recover the organic solvent by distillation and increase the concentration of nonvolatile components, depending on the intended use.

The obtained aqueous pigment dispersion preferably has a pigment having a volume average particle diameter of 500 nm or less,
The range of 0 to 500 nm is more preferable. When the volume average particle diameter is larger than 500 nm, gloss and glossiness of the object to be coated, and those having good coloring power tend not to be obtained, and in a recording liquid such as a writing instrument, clogging at a nozzle may occur. . Also, it is very difficult and impractical to make the diameter smaller than 10 nm.

The aqueous coloring liquid using the aqueous pigment dispersion obtained by the production method of the present invention includes, for example, aqueous paints for automobiles, painted steel plates, building materials, cans, etc., printing agents for dyeing fibers,
Aqueous inks such as gravure inks and flexo inks, water-based ballpoint pens, fountain pens, water-based sign pens, water-based markers and other writing implement inks, and aqueous recording liquids for on-demand inkjet printers such as bubble jet, thermal jet, and piezo systems, Examples include a dispersion for a color filter used in a liquid crystal television, a laptop personal computer, and the like, but are not limited to these uses.

The aqueous coloring liquid contains an aqueous pigment dispersion obtained by the production method of the present invention, a film-forming resin, a curing agent thereof, various auxiliaries, an organic solvent, water, a basic substance, various pigments and the like. It is conveniently mixed and prepared according to the application.

The content of the aqueous pigment dispersion obtained by the production method of the present invention in the aqueous coloring liquid is 5% in terms of pigment.
0 wt% or less is preferable, and the range of 0.1 to 40 wt% is particularly preferable. When the proportion of the pigment exceeds 50% by weight, the viscosity in the aqueous coloring liquid becomes high, and there is a tendency that the object to be coated cannot be colored.

The pigment in the aqueous pigment dispersion to be mixed with the aqueous coloring liquid preferably has an average primary particle diameter of 500 nm or less, particularly preferably in the range of 200 nm to 5 nm.

Examples of the film-forming resin include glue, gelatin, casein, albumin, gum arabic,
Natural proteins such as fish grew, alginic acid, methylcellulose, carboxymethylcellulose,
Polyethylene oxide, hydroxyethyl cellulose,
Polyvinyl alcohol, polyacrylamide, aromatic amide, polyacrylic acid, polyvinyl ether, polyvinylpyrrolidone, acrylic, polyester, alkyd, urethane, amide resin, melamine resin, ether resin, fluororesin, styrene acrylic resin, styrene maleic resin, etc. Examples include general polymers such as synthetic polymers, photosensitive resins, thermosetting resins, ultraviolet curable resins, and electron beam curable resins, but are not particularly limited thereto. These are selected and used depending on the use of the aqueous coloring liquid.

The ratio of these film-forming resins in the aqueous coloring liquid is preferably in the range of 0 to 50% by weight. Depending on the application, the resin used in the aqueous pigment dispersion acts as a resin for forming a coating film, or does not require a resin for forming a coating film. It does not necessarily require a film-forming resin.

Examples of the curing agent for the film-forming resin include amino resins such as melamine resin, benzoguanamine resin and urea resin, phenol resins such as trimethylolphenol and condensates thereof, tetramethylene diisocyanate (TDI), diphenylmethane diisocyanate. (MD
I), hexamethylene diisocyanate (HDI), naphthalene diisocyanate (NDI), isophorone diisocyanate (IPDI), xylylene diisocyanate (XDI), polyisocyanates such as modified isocyanates and blocked isocyanates, aliphatic amines, aromatic amines, Amines such as N-methylpiperazine, triethanolamine, morpholine, dialkylaminoethanol, benzyldimethylamine, polycarboxylic acid, phthalic anhydride, maleic anhydride, hexahydrophthalic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride Acid, acid anhydride such as ethylene glycol bistrimellitate, bisphenol A type epoxy resin,
Phenolic epoxy resin, glycidyl methacrylate copolymer, glycidyl ester resin of carboxylic acid, epoxy compound such as alicyclic epoxy, polyether polyol, polybutadiene glycol, polycaprolactone polyol, trishydroxyethyl isocyanate (T
Alcohols such as HEIC), polyvinyl compounds as unsaturated group-containing compounds used for radical curing or UV curing or electron beam curing with peroxides, polyallyl compounds, vinyl compounds such as reaction products of glycol or polyol with acrylic acid or methacrylic acid, etc. Is mentioned.

The curing agent is appropriately selected and used depending on the application and suitability, but may not be used. The use ratio of the curing agent is 0 to 5 with respect to 100% by weight of the film-forming resin.
A range of 0% by weight is preferred, and a range of 0 to 40% by weight is particularly preferred.

Examples of the organic solvent include methyl alcohol, ethyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol and n-butyl alcohol.
Alcohols such as propyl alcohol and isopropyl alcohol; amides such as dimethylformaldehyde and dimethylacetamide; ketones such as acetone and methyl ethyl ketone; tetrahydrofuran, dioxane, ethylene glycol methyl ether, ethylene glycol ethyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether; Ethers such as triethylene glycol monomethyl ether and triethylene glycol monoethyl ether; ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, diethylene glycol, polyethylene glycol, and polypropylene glycol Alcohol such as glycerin S; N- methyl - pyrrolidone,
1,3-dimethyl-2-imidazolidinone and the like. Among these water-soluble organic solvents, polyhydric alcohols and ethers are preferable.

The content ratio of the organic solvent in the aqueous coloring liquid is 5
0 wt% or less is preferable, and the range of 0 to 30 wt% is particularly preferable. In particular, if the performance of the aqueous coloring liquid is not inferior, it is needless to say that those containing no coloring liquid are preferable from the viewpoint of environmental problems.

Auxiliaries used as required include dispersing wetting agents, anti-skinning agents, ultraviolet absorbers, antioxidants,
Preservatives, fungicides, pH adjusters, viscosity adjusters, chelating agents, various auxiliary materials such as surfactants and stabilizers,
It is not limited to these. As the basic substance, for example,
Inorganic compounds such as sodium hydroxide and potassium hydroxide; ethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-ethyldiethanolamine, 2-amino-2-methylpropanol, 2-ethyl-2-amino-1 , 3-propanediol, 2- (aminoethyl) ethanolamine, tris (hydroxymethyl) aminomethane, ammonia, piperidine, morpholine, and other organic amine compounds, but are not limited thereto.

As a disperser for dispersing the aqueous pigment dispersion obtained by the production method of the present invention in these aqueous coloring liquids, a simple known disperser such as Disper is sufficient, but is not limited thereto. Not something.

As a method for producing an aqueous coloring liquid, the above-mentioned aqueous pigment dispersion, a film-forming resin, an effect agent thereof, various auxiliaries, an organic solvent, water, various pigment pigment compositions and the like are simply added, stirred and mixed. In the case of adding a high-viscosity resin or an organic solvent, the aqueous pigment dispersion is stirred, and
It is more preferable to sequentially add the above resin, effect agent, organic solvent, and various auxiliaries.

The aqueous coloring liquid containing the aqueous pigment dispersion obtained by the production method of the present invention can be produced according to its use. In addition, storage stability required for the aqueous coloring liquid, performance such as hydrophilicity to prevent clogging of the nozzle with a pen tip of a writing instrument and solvent stability, water resistance, weather resistance, transparency and clarity etc. It is possible to provide a coating film having excellent properties.

[0118]

The present invention will be described below in more detail with reference to Synthesis Examples, Comparative Examples and Examples, but the present invention is not limited to the scope of these Examples. In the following examples, “parts” and “%” are unless otherwise specified.
"Parts by weight" and "% by weight" are indicated respectively.

The molecular weight in the present invention is determined by GPC
(Gel permeation chromatography), and the volume average particle diameter is “UPA-15”.
“0” (Laser Doppler type particle size distribution meter manufactured by JGC Corporation)
It is measured by the following.

(Synthesis Example 1) [Synthesis of Vinyl Resin Having Carboxyl Group and Hydroxyl Group] A 3 liter four-necked flask equipped with a dropping device, a thermometer, a nitrogen gas inlet tube, a stirrer, and a reflux condenser was provided. , 1,000 parts of isopropyl alcohol and heated to 75 ° C., then 630 parts of n-butyl methacrylate, 50 parts of n-butyl acrylate, 150 parts of 2-hydroxyethyl methacrylate, 170 parts of acrylic acid and tert-butyl peroxy. A mixed solution consisting of 80 parts of 2-ethylhexanoate ("Perbutyl O" manufactured by NOF Corporation) was dropped over 2 hours, and reacted at the same temperature for 15 hours. After completion of the reaction, isopropyl alcohol was added to adjust the nonvolatile content to 50%. A resin solution having an acid value of 128 KOH mg / solid resin 1 g and a number average molecular weight of 6,900 with a resin solid content of 1900 g (resin solid content) 1) was obtained.

(Synthesis Example 2) [Synthesis of Vinyl Resin Having Carboxyl Group and Hydroxyl Group] An organic solvent was used in 1000 parts of methyl ethyl ketone, a mixed solution of a monomer and a polymerization initiator was used in 405.2 parts of n-butyl methacrylate, and n -45.6 parts of butyl acrylate,
In the same manner as in Synthesis Example 1 except that the mixture was changed to a mixed solution consisting of 150 parts of 2-hydroxyethyl methacrylate, 200 parts of styrene, 199.3 parts of methacrylic acid, and 80 parts of tertiary butyl peroxy-2-ethylhexanoate,
Acid value at resin solids is 127 KOHmg / resin solids 1
g, a resin solution (2) having a number average molecular weight of 9,000 was obtained.

(Synthesis Example 3) [Synthesis of Vinyl Resin Having Carboxyl Group and Epoxy Group (for Crosslinking Agent)] 3 liters equipped with a dropping device, a thermometer, a nitrogen gas introducing tube, a stirring device, and a reflux cooling tube After charging 1,000 parts of methyl ethyl ketone and raising the temperature to 75 ° C., 83 parts of n-butyl methacrylate, 385 parts of n-butyl acrylate, 150 parts of 2-hydroxyethyl methacrylate, 75 parts of glycidyl methacrylate, A mixed solution consisting of 107 parts of methacrylic acid, 200 parts of styrene and 80 parts of tert-butylperoxy-2-ethylhexanoate was added dropwise over 4 hours, and reacted at the same temperature for 6 hours. After completion of the reaction, methyl ethyl ketone was added to adjust the non-volatile content to 50%, and the resin solution having an acid value of 69 KOH mg / g of resin solid content / g of resin solid content and a number average molecular weight of 13,000 (3,000). ) Got.

(Synthesis Example 4) [Synthesis of Vinyl Resin Having Carboxyl Group and Epoxy Group] A mixture of a monomer and a polymerization initiator was mixed with 335 parts of n-butyl methacrylate, 358 parts of n-butyl acrylate, and
-Resin solid in the same manner as in Synthesis Example 3 except that the mixture was changed to a mixture comprising 150 parts of hydroxyethyl methacrylate, 50 parts of glycidyl methacrylate, 107 parts of methacrylic acid and 80 parts of tert-butyl peroxy-2-ethylhexanoate. A resin solution (4) having an acid value per minute of 67 KOH mg / resin solid content of 1 g and a number average molecular weight of 10,400 was obtained.

(Synthesis Example 5) [Synthesis of Vinyl Resin Having Carboxyl Group and Epoxy Group] A mixture of a monomer and a polymerization initiator was mixed with 335 parts of n-butyl methacrylate, 312 parts of n-butyl acrylate, and 2
-Resin solid in the same manner as in Synthesis Example 1 except that the mixture was changed to a mixture comprising 150 parts of hydroxyethyl methacrylate, 50 parts of glycidyl methacrylate, 153 parts of methacrylic acid and 80 parts of tert-butylperoxy-2-ethylhexanoate. Thus, a resin solution (5) having an acid value of 98 KOH / g and a resin solid content of 1 g and a number average molecular weight of 9,900 was obtained.

[0125]

[Table 1]

<Example 1> When resin solution (1) and Nicalac MX-035 (water-soluble melamine; methyl etherified melamine manufactured by Sanwa Chemical Industry Co., Ltd.) were used as a crosslinking agent.

Determination of Neutralization Ratio (Using Sodium Hydroxide as Base) Resin Solution (1): In the case where the weight ratio of solids of Nicalac MX-035 is 8: 2 16 parts of resin solution (1) (solids content) 8 parts), 2 parts of Nikarac MX-035 and 20% of the number of parts shown in Table 2 below.
After mixing with an aqueous solution of sodium hydroxide and adding ion-exchanged water with stirring to make the total 200 parts, the mixture was charged into an autoclave and subjected to a crosslinking reaction at 140 ° C. for 4 hours.
The state of precipitation of the crosslinked product was observed. Table 2 shows the results.

[0128]

[Table 2] From the above results, it was found that the neutralization ratio had an optimum value around 60%. Therefore, the neutralization rate was set to 60%.

Production of Aqueous Pigment Dispersion Resin solution (1) 16 parts (solids content: 8 parts)
X-035 2 parts, 20% aqueous sodium hydroxide solution
2 parts and 59.8 parts of ion-exchanged water were mixed, and the neutralization ratio was 60%.
% Resin aqueous solution was prepared. "Fastogen Blue TGR" (Cyanine blue pigment manufactured by Dainippon Ink and Chemicals, Inc.) 2
0 parts were added to prepare a pigment slurry.

This pigment slurry was dispersed using a Dynomill KDL type until the volume average particle diameter of the pigment was 200 nm or less to obtain an aqueous dispersion (pigment slurry dispersion). The dispersion conditions were as follows: vesicle capacity: 0.6 L, zirconia beads of 0.5 mmφ were used at a filling rate of 80%, and peripheral speed: 14 m
/ S, dispersion temperature; 40 ° C. or less, residence time of the dispersion in the vessel; dispersion, 500 g / hr. The volume average particle diameter after dispersion was 148 nm.

After dispersion, the aqueous dispersion has a nonvolatile content of 7.
Ion-exchanged water was added so as to be 5%. The dispersion was charged into an autoclave, at a temperature of 140 ° C. and a pressure of 4 kg / c.
Crosslinking was performed under the conditions of m ² .

After crosslinking, distillation was carried out to adjust the non-volatile content to 20%, and an aqueous pigment dispersion having a pH of 8.5 and a volume average particle diameter of 146 nm was obtained.

This aqueous pigment dispersion can be produced only by performing distillation and concentration after crosslinking. Compared to the acid precipitation method of Comparative Example 1, the aqueous pigment dispersion is subjected to acid precipitation, filtration, washing, and redispersion. The process can be omitted, saving energy and labor.

<Comparative Example 1> An aqueous dispersion (pigment slurry dispersion) was obtained in the same manner as in Example 1, and the pH was adjusted to 4 using a 1% aqueous hydrochloric acid solution, followed by acid precipitation. Further, the mixture was filtered and washed with ion-exchanged water to obtain a wet pigment. The pH was adjusted to 9 to 10 while adding 20% sodium hydroxide to the wet pigment and redispersing with a disper, and the non-volatile content was adjusted to 15% with ion-exchanged water.
Thereafter, the mixture was charged into an autoclave and crosslinked under the conditions of a temperature of 140 ° C. and a pressure of 4 kg / cm ² to obtain an aqueous pigment dispersion. The pH of the obtained aqueous pigment dispersion was 9.2, and the volume average particle size was 155 nm.

In producing this aqueous pigment dispersion, a step of performing acid precipitation, filtration, and washing after crosslinking, and a step of redispersion in order to precipitate and agglomerate the dispersed product, as compared with Example 1, were carried out. It took a lot of time and energy to do so.

<Comparative Example 2> The resin neutralization ratio of the aqueous resin solution was 4
An aqueous pigment dispersion was produced in the same manner as in Example 1 except that the dispersion was adjusted to 0%. The volume average particle size before crosslinking is 19
At 0 nm, dispersibility in the Dynomill was poor (residence time of dispersion in vessel; dispersion 250 g / hr). The resulting aqueous pigment dispersion had a pH of 7.6 and a volume average particle size of 5
At 20 nm, aggregation occurred, and it could not be used as an aqueous pigment dispersion.

<Example 2> In the case of using the resin solution (2) and the resin solution (3) as a crosslinking agent

Measurement of Neutralization Ratio as Crosslinking Condition Resin Solution (2): Resin Solution (3) When Resin Solids Weight Ratio is 7: 3 (Total Acid Value 100, Neutralizing Base is Triethylamine) Resin Solution (2) 14 parts (7 parts in solid content)
And 6 parts of resin solution (3) and triethylamine in the number of parts shown in Table 3 below were mixed, and ion-exchanged water was added with stirring to make a total of 200 parts. Then, the mixture was charged in an autoclave and heated at 120 ° C. And a cross-linking reaction was performed for 2 hours, and a precipitation state of a cross-linked product was observed. Table 3 shows the results.

[0139]

[Table 3] From the above results, it was found that the neutralization ratio had an optimum value around 70%. Therefore, the neutralization rate was set to 70%.

Production of Aqueous Pigment Dispersion 14 parts (7 parts in solid content) of the resin solution (2), 6 parts of the resin solution (3), 1.26 parts of triethylamine and 58.74 parts of ion-exchanged water were mixed. A resin aqueous solution having a modulus of 70% was prepared. Carbon black # 9 in this resin aqueous solution
20 (60 parts of carbon black pigment manufactured by Mitsubishi Chemical Corporation) was added to prepare a pigment slurry.

This pigment slurry was dispersed using a Dynomill KDL type until the volume average particle diameter of the pigment was 200 nm or less to obtain an aqueous dispersion (pigment slurry dispersion). The dispersion conditions were as follows: vesicle capacity: 0.6 L, zirconia beads of 0.5 mmφ were used at a filling rate of 80%, and peripheral speed: 14 m
/ S, dispersion temperature; 25 ° C. or less, residence time of the dispersion in the vessel; dispersion, 500 g / hr. The volume average particle diameter after dispersion was 107 nm.

After the dispersion, ion-exchanged water was added so that the nonvolatile content of the pigment slurry dispersion became 7.5%. The dispersion was charged into an autoclave, and the temperature was 120 ° C. and the pressure was 2
Crosslinking was performed at kg / cm ² for 4 hours.

After crosslinking, distillation was carried out to adjust the nonvolatile content to 20%, and an aqueous pigment dispersion having a pH of 8.0 and a volume average particle diameter of 98 nm was obtained.

This aqueous pigment dispersion can be produced only by performing distillation and concentration after crosslinking, and is called an acid precipitation, filtration, washing step, and a redispersion as compared with the acid precipitation method of Comparative Example 3 below. The process can be omitted, saving energy and labor. Further, the problem of waste liquid treatment has been eliminated.

<Comparative Example 3> An aqueous dispersion (pigment slurry dispersion) was obtained in the same manner as in Example 2, and the pH was adjusted to 4 using a 1% aqueous hydrochloric acid solution, followed by acid precipitation. Further, the mixture was filtered and washed with ion-exchanged water to obtain a wet pigment. Triethylamine was added to this wet pigment, and the pH was adjusted to 9 to 10 while redispersing with a disper, and the non-volatile content was adjusted to 15% with ion-exchanged water. afterwards,
Charged in an autoclave, temperature 140 ° C, pressure 4kg /
Crosslinking was performed under the condition of cm ² to obtain an aqueous pigment dispersion. The pH of the obtained aqueous pigment dispersion was 8.3, and the volume average particle size was 103 nm.

In preparing this aqueous pigment dispersion, a step of performing acid precipitation, filtration and washing, and a step of redispersion for acidifying and aggregating the dispersed product are required as compared with Example 2. Therefore, it required much labor and energy.
In addition, since the filtrate contained an organic amine salt, it was necessary to treat wastewater.

<Example 3> In the case of resin (4) having a self-crosslinkable functional group and an acidic group, measurement of neutralization ratio as a crosslinking condition (neutralization base is triethanolamine) 20 parts of resin solution (4) (10 parts in solid content) and Table 4 below
After mixing with triethanolamine in the number of parts indicated in (1) and adding ion-exchanged water with stirring to make the total 200 parts, the mixture was charged into an autoclave and subjected to a crosslinking reaction at 120 ° C. for 4 hours to obtain a resin precipitation state. Was observed. Table 4 shows the results.

[0148]

[Table 4] From the above results, it was found that the neutralization ratio had an optimum value around 90%. Therefore, the neutralization rate was set to 90%.

Preparation of Aqueous Pigment Dispersion Resin (4) (20 parts (solids: 10 parts), triethanolamine (1.67 parts) and ion-exchanged water (58.33 parts) were mixed, and a neutralization ratio of 90% was obtained. An aqueous solution was prepared. In this resin aqueous solution, "Fastogen Super Magenta (Fa
Stogen SuperMagenta) RTS (a quinacridone pigment manufactured by Dainippon Ink and Chemicals, Inc.) was added to prepare a pigment slurry.

The pigment slurry was dispersed using a Dynomill KDL type to a volume average particle size of 200 nm or less to obtain an aqueous dispersion (pigment slurry dispersion). Dispersion conditions were as follows: Vessel capacity: 0.6 L, zirconia beads of 0.5 mmφ were used at a filling rate of 80%, peripheral speed: 14 m / s,
Dispersion temperature: 30 ° C. or less, residence time of the dispersion in the vessel; dispersion 250 g / hr. The volume average particle size before crosslinking was 165 nm.

After the dispersion, ion-exchanged water was added so that the non-volatile content of the pigment slurry dispersion became 7.5%. The dispersion was charged into an autoclave, and the temperature was 120 ° C. and the pressure was 2
Crosslinking was performed at kg / cm ² for 4 hours.

After crosslinking, distillation was performed to adjust the concentration of non-volatile components to 20% to obtain an aqueous pigment dispersion having a pH of 8.1 and a volume average particle diameter of 161 nm.

This aqueous pigment dispersion can be produced by simply performing distillation and concentration after crosslinking, and can eliminate the steps of acid precipitation, filtration, washing and redispersion as compared with the acid precipitation method. Energy and labor were saved. Further, the problem of waste liquid treatment has been eliminated.

<Comparative Example 4> The resin neutralization ratio of the aqueous resin solution was 6
An aqueous pigment dispersion was produced in the same manner as in Example 3, except that the dispersion was adjusted to 0%. The volume average particle size before crosslinking is 195
The dispersibility was poor in nm, and the pH of the obtained aqueous pigment dispersion was 8.8, and the volume average particle diameter was 482 nm and the particles were aggregated.

<Example 4> In the case of resin (5) having a self-crosslinkable functional group and an acidic group: Measurement of neutralization rate as a crosslinking condition (neutralized base is triethanolamine) 20 parts of resin solution (5) (10 parts in solid content) and Table 5 below
Was mixed with ion-exchanged water while stirring to make a total of 200 parts, charged in an autoclave, and allowed to undergo a crosslinking reaction at 120 ° C. for 4 hours to obtain a crosslinked product. The precipitation state was observed. Table 5 shows the results.

[0156]

[Table 5] From the above results, it was found that the neutralization ratio had an optimum value around 70%. Therefore, the neutralization rate was set to 70%.

Preparation of Aqueous Pigment Dispersion Resin (5) (20 parts (solids: 10 parts), triethanolamine (1.86 parts) and ion-exchanged water (58.14 parts) were mixed together to obtain a resin having a neutralization ratio of 70%. An aqueous solution was prepared. In this resin aqueous solution, "Shimler First Yellow (Syml
er Fast Yellow) 4192 (Benzimidazolone pigment manufactured by Dainippon Ink and Chemicals, Inc.) was added to prepare a pigment slurry.

Example 3 except that this pigment slurry was used.
In the same manner as in the above, an aqueous dispersion (pigment slurry dispersion) was obtained. The volume average particle diameter after dispersion was 127 nm.

After the dispersion, ion-exchanged water was added so that the nonvolatile content of the pigment slurry dispersion became 7.5%. The dispersion was charged into an autoclave, and the temperature was 120 ° C. and the pressure was 2
Crosslinking was performed at kg / cm ² for 4 hours.

After crosslinking, distillation was carried out to adjust the non-volatile content to 20% to obtain an aqueous pigment dispersion having a pH of 8.3 and a volume average particle diameter of 118 nm.

This aqueous pigment dispersion can be produced only by performing distillation and concentration after crosslinking, and can eliminate the steps of acid precipitation, filtration, washing and redispersion as compared with the acid precipitation method. Energy and labor were saved. Further, the problem of waste liquid treatment has been eliminated.

<Example 5> In the case of resin solution (5) having a self-crosslinkable functional group and an acidic group: Measurement of neutralization ratio as a crosslinking condition (neutralized base is triethylamine) 20 parts of resin solution (5) (Solid content: 10 parts) and Table 6 below
After mixing with the number of parts of triethylamine shown in (1) and adding ion-exchanged water with stirring to make the total 200 parts,
The reaction mixture was charged in an autoclave and allowed to undergo a crosslinking reaction at 120 ° C. for 4 hours, and a precipitation state of a crosslinked product was observed. Table 6 shows the results.

[0163]

[Table 6] From the above results, it was found that the neutralization ratio had an optimum value around 70%. Therefore, the neutralization rate was set to 70%.

Preparation of Aqueous Pigment Dispersion 20 parts of resin solution (5) (10 parts in solid content), 1.26 parts of triethylamine and 58.74 parts of ion-exchanged water were mixed, and a resin aqueous solution having a neutralization ratio of 70% was added. Prepared. In this aqueous resin solution, "Shimler First Yellow (Symler
Fast Yellow) 20 parts of 8GF (disazo yellow pigment manufactured by Dainippon Ink and Chemicals, Inc.) was added to prepare a pigment slurry.

This pigment slurry was dispersed using a Dynomill KDL type to a volume average particle diameter of 200 nm or less to obtain an aqueous dispersion (pigment slurry dispersion). Dispersion conditions were as follows: Vessel capacity: 0.6 L, zirconia beads of 0.5 mmφ were used at a filling rate of 80%, peripheral speed: 14 m / s,
Dispersion temperature: 30 ° C. or less, residence time of the dispersion in the vessel; dispersion 150 g / hr. The volume average particle diameter after dispersion was 175 nm.

After the dispersion, ion-exchanged water was added so that the nonvolatile content of the pigment slurry dispersion became 7.5%. The dispersion was charged into an autoclave, and the temperature was 120 ° C. and the pressure was 2
Crosslinking was performed at kg / cm ² for 4 hours.

After crosslinking, distillation was carried out to adjust the nonvolatile content to 20% to obtain an aqueous pigment dispersion having a pH of 8.3 and a volume average particle diameter of 173 nm.

This aqueous pigment dispersion can be produced only by performing distillation and concentration after crosslinking, and the steps of acid precipitation, filtration, washing and redispersion can be omitted as compared with the acid precipitation method. Energy and labor were saved. Further, the problem of waste liquid treatment has been eliminated.

<Example 6> In the case of resin (4) having a self-crosslinkable functional group and an acidic group: Measurement of neutralization ratio as a crosslinking condition (neutralized base is dimethylaminoethanol) 20 parts of resin solution (4) (10 parts in solid content) and Table 7 below
Mixed with the indicated number of dimethylaminoethanol,
While stirring, ion-exchanged water was added to make a total of 200 parts, then charged in an autoclave, subjected to a crosslinking reaction at 120 ° C. for 4 hours, and a precipitation state of a crosslinked product was observed. Table 7 shows the results.

[0170]

[Table 7] From the above results, it was found that the neutralization ratio had an optimum value around 60%. Therefore, the neutralization rate was set to 60%.

Preparation of Aqueous Pigment Dispersion 20 parts (10 parts in solid content) of resin solution (4), 0.67 part of dimethylaminoethanol and 59.33 of ion-exchanged water
Were mixed to prepare a resin aqueous solution having a neutralization ratio of 60%. 20 parts of "Fastogen Super Maroon PSK" (Perylene pigment manufactured by Dainippon Ink and Chemicals, Inc.) was added to the aqueous resin solution to prepare a pigment slurry.

This pigment slurry was dispersed using a Dynomill KDL type to a volume average particle diameter of 200 nm or less to obtain an aqueous dispersion (pigment slurry dispersion). Dispersion conditions were as follows: Vessel capacity: 0.6 L, zirconia beads of 0.5 mmφ were used at a filling rate of 80%, peripheral speed: 14 m / s,
Dispersion temperature: 30 ° C. or less, residence time of the dispersion in the vessel; dispersion 150 g / hr. The volume average particle size before crosslinking was 89 nm.

After the dispersion, ion-exchanged water was added so that the nonvolatile content of the pigment slurry dispersion became 7.5%. The dispersion was charged into an autoclave, and the temperature was 120 ° C. and the pressure was 2
Crosslinking was performed at kg / cm ² for 4 hours.

After crosslinking, distillation was carried out to adjust the concentration of non-volatile components to 20% to obtain an aqueous pigment dispersion having a pH of 8.2 and a volume average particle diameter of 93 nm.

This aqueous pigment dispersion can be produced only by performing distillation and concentration after crosslinking, and the steps of acid precipitation, filtration, washing and redispersion can be omitted as compared with the acid precipitation method. Energy and labor were saved. Further, the problem of waste liquid treatment has been eliminated.

Table 8 below summarizes the properties of the aqueous pigment dispersions obtained in Examples 1 to 6 and Comparative Examples 1 to 4.

In the pigment column in Table 8, TGR is “Fastogen Blue TG”.
R ", carbon is carbon black # 960, RTS is" Fastogen Super Magenta "
r Magenta) RTS ”, 4192 is“ Symler Fast Yellow 4192 ”,
8GF stands for "Symler First Yellow"
Fast Yellow) 8GF ”, PSK is“ Fastogen Super Maroon PSK ”
And in the column of the type of resin solution, 1, 2, 3, 4,
5 is a resin solution (1) obtained in Synthesis Examples 1 to 5, respectively.
(2), (3), (4), (5), MX-035 indicates Nicalac MX-035, and in the column of base / neutralization ratio, TEA is triethylamine, TEOHA is triethanolamine, and DMAE is dimethylaminoethanol. Is shown.

[0178]

[Table 8]

Reference Example 1 (Production of an aqueous pigment dispersion of cyan using a commercially available resin) As a resin for dispersing an aqueous pigment, Hiros X-205L (styrene-maleic acid resin manufactured by Seiko Chemical Co., Ltd .;
%) 40 parts, ion-exchanged water 40 parts and "fastogen
Blue (Fastogen Blue) TGR ”20 parts
A pigment slurry was prepared.

The pigment slurry was dispersed using a Dynomill KDL type to produce an aqueous pigment dispersion. Dispersion conditions were as follows: Vessel capacity: 0.6 L, zirconia beads of 0.5 mmφ were used at a filling rate of 80%, peripheral speed: 14 m / s,
Dispersion temperature: 40 ° C. or less, residence time of the dispersion in the vessel; dispersion 250 g / hr.

The non-volatile content was adjusted to 20 using ion-exchanged water.
%, And an aqueous pigment dispersion having a pH of 8.1 and a volume average particle diameter of 171 nm was obtained.

<Reference Example 2> (Production of aqueous magenta pigment dispersion using commercially available resin) "Fastogen Blue TGR"
Instead of "Fastgen Super Magenta
(Fastogen Super Magenta) RTS "was used to produce a magenta aqueous pigment dispersion in the same manner as in Reference Example 1. The obtained aqueous pigment dispersion has a nonvolatile content of 20%, p
H8.2, volume average particle diameter: 198 nm.

<Reference Example 3> (Production of yellow aqueous pigment dispersion using commercially available resin) "Fastogen Blue TGR"
Instead of "Shimla First Yellow (Sy
muler Fast Yellow) 4192 ", except that a yellow aqueous pigment dispersion was obtained. The obtained aqueous pigment dispersion has a nonvolatile content of 20%, pH
8.2, the volume average particle diameter was 265 nm.

Reference Example 4 (Production of Black Aqueous Pigment Dispersion Using Commercial Resin) "Fastogen Blue TGR"
Was prepared in the same manner as in Reference Example 1 except that carbon black # 960 was used in place of the above, to obtain a black aqueous pigment dispersion. The obtained aqueous pigment dispersion has a nonvolatile content of 20%,
The pH was 8.0 and the volume average particle diameter was 140 nm.

Reference Example 5 (Production of aqueous pigment dispersion of perylene using a commercially available resin) "Fastogen Blue TGR"
Instead of "Fast Gen Super Maroon"
An aqueous pigment dispersion of perylene was obtained in the same manner as in Reference Example 1 except that "PSK" was used. The obtained aqueous pigment dispersion has a nonvolatile content of 20%, a pH of 8.3, and a volume average particle size of 2
06 nm.

<Example 7> Preparation of aqueous recording liquid of cyan Aqueous pigment dispersion of Example 1 22.5 parts Ethylene glycol 5.0 parts Glycerin 10.0 parts Isopropyl alcohol 3.0 parts Ion-exchanged water 59.5 Were mixed with a disper to prepare a yellow aqueous recording liquid.

Similarly, aqueous recording liquids of magenta, yellow and black were prepared using the aqueous pigment dispersion of Example 3, the aqueous pigment dispersion of Example 4, and the aqueous pigment dispersion of Example 2, respectively. .

Table 9 shows the volume average particle diameters of the pigments in the cyan, magenta, yellow, and black recording liquids and the volume average particle diameter after storage at room temperature for 30 days.

The volume average particle diameter of the pigment in the recording liquid of the present example was almost the same before and after storage, no sedimentation of particles was observed, and the storage stability was higher than that of the conventional pigment dispersion. It is evident that they have very good properties and sedimentation.

Next, using the above recording liquid, a full-color recorded image of yellow, magenta, cyan, and black was converted to OHP using a commercially available bubble jet printer.
Recorded on sheets and copy paper. This recorded image had high definition and color density, and was excellent in color rendering properties and transparency. Further, the image recorded on the OHP sheet showed a colorful projection because of excellent transparency. In addition, the nozzle for ejecting ink was not clogged even after repeated use.

Comparative Example 5 Cyan, magenta, and magenta were prepared in the same manner as in Example 7 except that the aqueous pigment dispersions of Reference Examples 1, 2, 3, and 4 were used instead of the aqueous pigment dispersion of Example 7.
Yellow and black aqueous recording liquids were prepared.

Table 9 shows the volume average particle size of the pigment in these recording liquids and the volume average particle size after storage at room temperature for 30 days.
It was shown to. The volume average particle diameter of the pigment in the recording liquid of this comparative example became large after storage, except for the black recording liquid, indicating aggregation of the particles and poor storage stability.

Next, a cyan color recorded image was recorded on an OHP sheet and copy paper using a commercially available bubble jet printer using the recording liquid. This recorded image had low definition and color density, and lacked color rendering properties and transparency. Further, the image recorded on the OHP sheet did not show an opaque and colorful projection, and could not be used for the OHP sheet. In addition, during repeated use, nozzles for ejecting ink were clogged, and the printer could not be used.

[0194]

[Table 9]

<Example 8> 112.5 parts of the yellow aqueous pigment dispersion obtained in Example 5, 13.5 parts of ion-exchanged water,
4.0 parts of isopropyl alcohol and "John Krill"
J74 "(a styrene acrylic resin manufactured by Johnson Wax Co.) was mixed with 70.0 parts with a glass rod to prepare an aqueous flexographic ink.

In preparing the aqueous flexographic ink, it was possible to prepare the aqueous flexographic ink simply by mixing without using a dispersing machine such as a bead mill or a roll. Therefore, no dispersing equipment was required, and the dispersing process and labor could be shortened. The manufacturing time can be reduced or the energy for dispersion energy can be saved.

Using the above flexographic ink, a thickness of 0.0
On a 5 mm acetate film, 0.15 mm (N
o. 6) The color was spread using a bar coder. The gloss and transparency of the obtained drawn film were much better than those obtained by using a flexographic ink using the pigment of Comparative Example 6 below.

Table 10 shows the volume average particle size of the pigment in the aqueous flexographic ink and the volume average particle size after storage at room temperature for 30 days. From the results shown in Table 10, the volume average particle diameter of the pigment in the aqueous flexographic ink of the present invention was almost the same before and after storage, indicating that the storage stability was much lower than that of the pigment obtained by the conventional dispersion method. It is clear that it is excellent.

<Comparative Example 6> Shimla First Yellow 8GF 15.0 parts "Johncryl J61" 23.0 parts (Styrene acrylic resin manufactured by Johnson Wax) Ion-exchanged water 23.0 parts Isopropyl alcohol 4.0 parts After measuring 120.0 parts of 3 mmφ glass beads in a polyethylene bottle and dispersing them for 2 hours using a paint conditioner, 70.0 parts of “John Krill J74” (styrene acrylic resin manufactured by Johnson Wax) and ion exchange 65.0 parts of water was added, and the mixture was dispersed for 10 minutes using a paint conditioner to prepare a flexographic ink.

In preparing the flexographic ink, a dispersing facility was required to disperse the ink for 2 hours with a paint conditioner, and labor and energy for dispersing the ink were required, and the production cost was high.

Using the above flexo ink, a thickness of 0.0
On a 5 mm acetate film, 0.15 mm (N
o. 6) The color was spread using a bar coder. The gloss and transparency of the obtained drawn film were inferior to those obtained when the flexographic ink of Example 7 was used.

Table 10 shows the volume average particle diameter of the pigment of the flexographic ink and the volume average particle diameter after storage at room temperature for 30 days. From the results shown in Table 10, the volume average particle diameter of the pigment in the aqueous flexographic ink of this comparative example was large after storage and showed a tendency to agglomerate, varnish separation was observed, and the stability was poor.

[0203]

[Table 10]

<Example 9>"WatersolS-7"
51 ”(Non-volatile content 5 manufactured by Dainippon Ink and Chemicals, Inc.)
56 parts (28 parts by solid content) of 0% water-soluble acrylic resin for baking paint, and 12.25 parts (by solid content) of "CYMEL 303" (98% active ingredient methyl etherified melamine resin manufactured by Mitsui Cyanamid Co.) 12 parts) and 100 parts (20 parts by solids) of the aqueous pigment dispersion of perylene obtained in Example 6, diluted with water to a nonvolatile content of 24%, and dissolved in water. A baked acrylic resin paint was prepared.

The paint was stored in a thermostatic chamber at 50 ° C. for 7 days to conduct a long-term storage stability test. As shown in Table 11, the volume average particle diameter of the pigment in the coating material was excellent in stability without change before and after storage.

[0206] This paint was treated with "BT-144 treated steel sheet".
(Zinc phosphate treated steel plate manufactured by Nippon Parker Rising Co., Ltd.) was coated using a bar coater so that the film thickness became 20 ± 2 μm, and after setting for 10 minutes, baking was performed at 150 ° C. for 20 minutes to obtain a test piece. Was prepared.

The test pieces were evaluated for water resistance as follows. The test piece was immersed in water at a temperature of 50 ° C.
After a lapse of time, the degree of blister generation was visually determined. Blisters did not occur at all, and a coating film having excellent water resistance was obtained. From this, it was clear that the water-based pigment-dispersed pigment had excellent water resistance.

Further, this paint was subjected to corona discharge treatment PET.
The film was coated using a bar coater so that the film thickness became 10 ± 1 μm.
For 20 minutes to prepare a test piece, and the gloss of the coating film was measured at 60 ° gloss using a haze gloss meter. The gloss was very high, and a coating film excellent in sharpness was obtained.

Comparative Example 7 An aqueous paint was prepared and stored in the same manner as in Example 9 except that the aqueous pigment dispersion of perylene of Reference Example 5 was used instead of the aqueous pigment dispersion of perylene of Example 6. The stability, water resistance and gloss were evaluated. Table 1
As shown in FIG. 1, the particle size of the pigment after storage increased, causing aggregation and poor storage stability. As a result of the water resistance test, blisters were generated, the water resistance was poor, and the gloss of the coating film was inferior to that of Example 9.

<Example 10> An aqueous paint was prepared in the same manner as in Example 9 except that the magenta aqueous pigment dispersion of Example 3 was used instead of the aqueous pigment dispersion of Example 6, and the storage stability was measured. As shown in Table 11 in which the evaluation of water resistance and gloss was performed, there was no change in the particle diameter of the pigment before and after storage, and the storage stability was excellent. Further, as a result of the water resistance test, no blister was generated, the water resistance was excellent, and the gloss of the coating film was excellent.

Comparative Example 8 An aqueous paint was prepared in the same manner as in Example 9 except that the aqueous pigment dispersion of Reference Example 2 was used instead of the aqueous pigment dispersion of Example 6, and storage stability and water resistance were measured. The properties and gloss were evaluated. As shown in Table-5, the particle size of the pigment after storage increased, causing aggregation and poor storage stability. Further, as a result of the water resistance test, blisters were generated, the water resistance was poor, and the gloss of the coating film was inferior to that of Example 10.

[0212]

[Table 11]

Evaluation criteria A: No abnormality. ：: Blister generation was slightly observed. Δ: Significant blister generation was observed. ×: Blisters were generated on the entire surface of the test piece. Storage test conditions: Storage in a constant temperature layer at 50 ° C for 7 days

[0214]

According to the production method of the present invention, an aqueous pigment dispersion excellent in pigment dispersibility and storage stability can be easily produced without the steps of acid precipitation and redispersion, and the production process is short, And has the advantage that labor can be reduced.
The obtained aqueous pigment dispersion is an aqueous ink, an aqueous recording liquid,
Aqueous paints and the like can also be suitably used for the aqueous coloring liquid.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09D 17/00 C09D 17/00 133/06 133/06

Claims (9)

[Claims] 1. A water-soluble resin (A1) obtained by neutralizing an acidic group in a hydrophobic resin (a1) having a crosslinkable functional group and an acidic group with a base, a pigment (B), and a crosslinking agent (C). Is dissolved and dispersed in an aqueous medium to obtain an aqueous dispersion (I), and then a crosslinking reaction is performed between the crosslinking functional group in the water-soluble resin (A1) and the crosslinking agent (C) to obtain the pigment (B). A method for producing an aqueous pigment dispersion in which a crosslinked product of a water-soluble resin (A1) is precipitated around a resin, or an acidic group in a hydrophobic resin (a2) having a self-crosslinkable functional group and an acidic group is neutralized with a base. The water-soluble resin (A2) and the pigment (B) are dissolved and dispersed in an aqueous medium to obtain an aqueous dispersion (II), and then the water-soluble resin (A2) is subjected to a self-crosslinking reaction. A method for producing an aqueous pigment dispersion in which a self-crosslinked product of a water-soluble resin (A2) is precipitated around (B). And the water-soluble resin (A
1) and (A2) are characterized in that they are water-soluble resins which dissolve in an aqueous medium before crosslinking, but neutralize acidic groups with an amount of base which precipitates in the aqueous medium after crosslinking. A method for producing an aqueous pigment dispersion. 2. A crosslinked product of a water-soluble resin (A1) or a water-soluble resin around a pigment (B) by crosslinking an aqueous dispersion (I) or (II) having a nonvolatile content of 20% by weight or less. The method according to claim 1, wherein the self-crosslinked product of (A2) is precipitated. 3. Hydrophobic resin (a1) or hydrophobic resin (a
3. The method according to claim 1, wherein 2) is an acrylic resin having a carboxyl group. 4. The hydrophobic resin (a1) or the hydrophobic resin (a
2) has an acid value of 30 to 250 KOH mg / resin solid content 1 g
The production method according to claim 1, 2 or 3, which is a resin. 5. The hydrophobic resin (a1) is a resin having a carboxyl group as a crosslinkable functional group and an acidic group, and the crosslinking agent (C) is a compound having an amino group or an epoxy group.
The method according to any one of claims 1 to 4, which is a compound having at least one compound. 6. The production method according to claim 1, wherein the hydrophobic resin (a2) is a resin having a carboxyl group and an epoxy group. 7. The hydrophobic resin (a1) or the hydrophobic resin (a
The production method according to any one of claims 1 to 6, wherein the base used for the neutralization in 2) is a tertiary amine. 8. An aqueous coloring liquid comprising the aqueous pigment dispersion obtained by the production method according to claim 1. Description: 9. The aqueous recording liquid according to claim 8, which is an aqueous ink, an aqueous recording liquid or an aqueous paint.