JPH0339534B2 - - Google Patents

Description

[Detailed description of the invention]

Industrial Application Fields The present invention is a pigment dispersion consisting of a pigment and a branched resin that has low viscosity and excellent compatibility with acrylic resins and resins other than acrylic resins, and is also effective as a resin for dispersing various pigments. Regarding the base composition. Prior Art The inventors have already used the formula

[Formula] (wherein R is an aliphatic, alicyclic, aromatic or heterocyclic hydrocarbon residue, n' is a real number of 2 to 6) and a polyfunctional epoxy compound represented by the formula In the formula, X is an acrylic prepolymer chain with a weight average molecular weight of 1000 to 100000 and a glass transition temperature of -20 to 100℃
The formula obtained by reacting an acrylic prepolymer having a terminal carboxyl group represented by

Based on the fact that the branched acrylic resin represented by the formula has a lower viscosity than a normal acrylic resin at the same molecular weight, a patent application was filed as Patent Application No. 58-218127. Furthermore, it was discovered that a resin for dispersing pigments with excellent dispersibility with various pigments could be obtained by supporting an electron-accepting group and/or an electron-donating group on the branched acrylic resin.
A patent application was filed as No. 124791. However, in the paint industry, paints are rarely prepared using only one type of resin, and various resins are usually mixed together as plasticizers, crosslinking agents, and modifiers. In this case, if the resins have good compatibility with each other, the desired low viscosity and improved pigment dispersibility can be achieved, but if the compatibility is poor, the intended results may not necessarily be obtained. There is. Therefore, regardless of the type of resin used, if it has excellent compatibility, maintains low viscosity even in the mixed state, and provides good pigment dispersibility,
It is of great benefit to the industry, and its low viscosity makes it possible to obtain paints with high non-volatile content and excellent workability and film performance. Means for Solving the Problems The present inventors have developed various resins (especially alkyd resins,
As a means of improving compatibility with polyester resins), we introduce some resin molecules that cause compatibility problems into resin molecules, and this book is based on the fact that compatibility can be improved by configuring new molecules. Completed the invention. To explain the contents of the present invention in detail:

[Formula] A polyfunctional epoxy compound represented by the formula and the formula X-
An acrylic prepolymer with a carboxyl group represented by COOH (X is an acrylic prepolymer chain) and a carboxyl group represented by Y-COOH (Y is a variety of resin residues, but alkyd and/or polyester residues are particularly preferred) X with
By reacting at least one or more prepolymers other than other resins. By synthesizing a branched resin and introducing a resin Y different from the acrylic resin represented by X,
The compatibility with various resins that are not compatible with Y but are compatible with Y is improved. Furthermore, for the purpose of improving the pigment dispersibility, paint, coating, and film performance of such resins, the branched resins may be made to support electron-accepting groups and/or electron-donating groups. To explain in detail the method for producing the above-mentioned branched resin, the carboxyl group-containing acrylic prepolymer represented by It can be obtained by copolymerizing monomers other than acid monomers using an initiator having a carboxyl group. In the case of (1) above, the monomers used include acid monomers, neutral monomers, monomers having a functional group that reacts with active hydrogen and/or active alkoxy groups, or monomers having active hydrogen and/or active alkoxy groups. Obtained by copolymerization. Typical acid monomers include carboxyl group-containing monomers, such as acrylic acid, methacrylic acid, itaconic acid, and maleic acid. Neutral monomers include ethylene, propylene,
Butadiene, isoprene, chloroprene, vinyl bromide, vinyl fluoride, acrylate esters (e.g. methyl, ethyl, butyl ester, etc.), methacrylate esters (e.g. methyl, ethyl, butyl ester, etc.), nitrile derivatives (e.g. acrylonitrile, methacrylate, etc.) nitrile, etc.), styrene derivatives (for example, α-methylstyrene), and the like. On the other hand, examples of the above-mentioned functional group-containing monomers include glycidyl acrylate, glycidyl methacrylate, etc. as glycidyl group-containing monomers,
Vinyl isocyanate, etc. can be selected as the isocyanate group-containing monomer, and vinyl chloride, vinylidene chloride, etc. can be selected as the chlorine-containing monomer. As the active hydrogen group-containing monomer '' above, acrylamide, methacrylamide, etc. can be used as an amide group-containing monomer, and N-methoxymethylolacrylamide, N-butoxymethylolacrylamide, etc. can be used as an active alkoxy group-containing monomer. Alternatively, the above functional group-containing monomers or active hydrogen group-containing monomers such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-
Hydroxyl-containing monomers such as hydroxypropyl methacrylate, N-methylolacrylamide, etc. can also be used. In the case of such a carboxyl group-containing acrylic prepolymer, the amount of carboxyl groups contained is on average 0.1 to 1.5 mol per molecule calculated based on the number average molecular weight.
mol, preferably 0.2 mol to 1.2 mol. If the amount of carboxyl groups exceeds 1.5 mol, the viscosity of the branched resin increases, and if it is less than 0.1 mol, a sufficient branched structure cannot be obtained, making it impossible to achieve the object of the present invention. On the other hand, in the case of (2) above, the monomers other than the acid monomer include the above neutral monomer, active hydrogen and/or
Alternatively, when polymerizing an acrylic resin, a monomer having a functional group that reacts with an active alkoxy group or a monomer having an active hydrogen and/or an active alkoxy group is used as an initiator commonly used, such as an azonitrile compound such as 2,2'-azo-
2,3-diazo-bicyclo[2, 2,1]heptene, 2,2,2'-azo-bis-propane, 1,
Polymerization is initiated using 1'-azo-bis-1-phenylethane, etc., and t-butyl peroxide, benzoyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, etc. as peroxide compounds, (1) By using a compound containing a carboxyl group as a chain transfer agent, such as mercaptoacetic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 0-mercaptobenzoic acid, etc., A carboxyl group can be introduced. On the other hand, monomers other than carboxyl group-containing monomers are added to (2) carboxyl group-containing initiators, such as 4,4'-azobis(4-cyanopentanoic acid), peroxide diglutaric acid, during polymerization of acrylic resin. A carboxyl group can also be introduced at the end of an acrylic prepolymer by initiating polymerization using, for example, a polymer. Furthermore, carboxyl groups can also be introduced into the terminals of the acrylic prepolymer by using both a carboxyl group-containing compound as the chain transfer agent (α) and a carboxyl group-containing initiator (β). be able to. In the polymerization of the carboxyl group-containing acrylic prepolymer obtained by the methods (1) and (2) above,
Using a polymerization method such as bulk polymerization, solution polymerization, or suspension polymerization if necessary, the reaction is carried out at a temperature above the decomposition temperature of the initiator, usually 70 to 170°C, by the total amount charging method, initiator dropping method, or monomer dropping method. The prepolymer can be synthesized by reacting at a temperature of 1 to 8 hours. When synthesizing such a prepolymer, the amount of the carboxyl group-containing chain transfer agent used in method (α) used to introduce carboxyl groups at the terminals of the acrylic prepolymer obtained by method (2) is determined based on the solidity of the prepolymer. Mold weight ratio: 0.2~
8% by weight, preferably in the range 0.3-5% by weight. On the other hand, when using a carboxyl group-containing initiator in method (β), the amount used is 0.3 to 12% by weight, preferably 0.4% by weight of the solid content of the prepolymer.
~8% by weight. If the amount of the carboxyl group-containing chain transfer agent used in method (1) exceeds the above 8% by weight, and the amount of the carboxyl group-containing initiator used in method (2) exceeds the above 12% by weight, The molecular weight of the polymer is significantly reduced, and therefore the molecular weight of the acrylic resin, which is the object of the present invention, is reduced, resulting in poor durability performance such as weather resistance and chemical resistance.
cannot exert sufficient effect. On the other hand, if the amount of the carboxyl group-containing chain transfer agent used is less than 0.2% by weight, or if the amount of the carboxyl group-containing initiator used is less than 0.3% by weight,
The molecular weight of the prepolymer increases significantly, and the reactivity with the glycidyl group of the polyfunctional epoxy compound decreases, which requires a long time to synthesize the acrylic resin that is the object of the present invention. If the molecular weight of the acrylic resin becomes too large, the viscosity will increase, causing problems such as making it unsuitable for use as a paint resin. The acrylic prepolymer having a carboxyl group synthesized under the above polymerization conditions does not impair the durability such as weather resistance and chemical resistance, solvent resistance, mechanical strength, etc. of the acrylic resin, which is the object of the present invention. In order to maintain low viscosity, the weight average molecular weight of the acrylic prepolymer (measured by gel permeation chromatography, polystyrene equivalent) is 1000 or more.
100,000, and preferably a glass transition temperature of -20 to 100°C. On the other hand, the at least one prepolymer Y-COOH other than the above-mentioned acrylic resin having a carboxyl group represented by X includes oil-free polyester resins containing a carboxyl group, long oil or short oil alkyd resins, and the like. On the other hand, in polyhydroxy resins such as polyether resins, polyurethane resins, and epoxy resins, such hydroxyl groups are converted to acid anhydrides, such as acetic anhydride, succinic anhydride, phthalic anhydride, maleic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride. Low acid content 1
It is possible to add one or more species by a conventional method so that a carboxyl group is included in the resin for use. Oil-free polyester resin is obtained by the condensation of polycarboxylic acids and polyhydric alcohols, and the polycarboxylic acids include trimellitic acid, trimellitic anhydride,
Phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, adipic acid, etc., and polyhydric alcohols such as pentaerythritol, trimethylolpropane, trimethylolethane, glycerin, polyethylene glycol, 1,6-hexanediol, neopentyl glycol , propylene glycol, ethylene glycol, etc. are commonly used. In addition to the above-mentioned polycarboxylic acids and polyhydric alcohols, long oil or short oil alkyd resins contain fatty acids such as soybean oil fatty acids, castor oil fatty acids, tall oil fatty acids, coconut oil fatty acids, cottonseed oil fatty acids, etc., or vegetable oils. For example, soybean oil, castor oil,
Tall oil, coconut oil, cottonseed oil, linseed oil, etc. are used. The above polyether resin is obtained by polymerizing propylene oxide, ethylene oxide, etc. using a polyhydroxy compound such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, sorbitol, pentaerythritol, sucrose, starch, or other initiator. It is resin. Polyurethane resins are obtained by addition-reacting polyhydroxy resins, such as oil-free polyester resins having hydroxyl groups, long oil or short oil alkyd resins, acrylic resins or polyether resins, and isocyanate compounds. Epoxy resins can generally be obtained by reacting a phenolic compound and epichlorohydrin, a polyhydric alcohol and epichlorohydrin, or an organic acid and epichlorohydrin. Further, as Y-COOH, an acrylic resin other than X containing a carboxyl group can also be used. The above carboxyl group-containing prepolymer, Y
-The amount of carboxyl groups contained in the resin in COOH is 0.1 on average per molecule calculated by number average molecular weight.
mol to 1.5 mol, preferably 0.2 mol to 1.2 mol. If the amount of carboxyl groups exceeds 1.5 mol, the viscosity of the branched resin increases, and if it is less than 0.1 mol, a sufficient branched structure cannot be obtained, and the object of the present invention cannot be achieved. Acrylic prepolymers containing carboxyl groups synthesized under such conditions, X-COOH and other resins containing carboxyl groups, Y-
By subjecting COOH to an addition reaction with the glycidyl group of a polyfunctional epoxy compound having two or more glycidyl groups, a branched resin with good compatibility, which is the object of the present invention, can be synthesized. The carboxylic acid resin prepolymer portion represented by X-COOH or Y-COOH may have various substituents (for example, F, CI, etc.) that do not affect the reaction between the carboxyl group and the glycidyl group, and may also have Si. may contain heteroatoms such as. The polyfunctional epoxy compound is a substance having two or more glycidyl groups, and these compounds may be saturated or unsaturated aliphatic, alicyclic, aromatic or heterocyclic compounds, and chlorine, These compounds, which may be substituted with substituents such as hydroxyl groups and ether groups, may be monomers or polymers. The polyfunctional epoxy compound of the present invention includes epoxidized esters of unsaturated monohydric alcohols and polyvalent aliphatic acids, such as adipic acid di(2,3-
epoxyhexyl), di(2,3-epoxybutyl) oxalate, di(2,3-epoxyhexyl) succinate, di(2,3-epoxybutyl) phthalate
and other glycidyl group-containing nitrogen compounds, such as diglycidylaniline and di- and triglycidylamine. Particularly preferred polyfunctional epoxy compounds for use in the production of the novel branched resins of the present invention are glycidyl ethers, particularly glycidyl ethers of polyhydric phenols and polyhydric alcohols. Glycidyl ethers of polyhydric phenols and polyhydric alcohols can be obtained by reacting epirochlorohydrin with desired polyhydric phenols or polyhydric alcohols in the presence of an alkali. For example, diglycidyl ether of bisphenol A, diglycidyl ether of resorcinol, triglycidyl ether of phloroglucinol, triglycidyl ether of tribidroxydibiphenyl, polyglycidyl ether of phenol formaldehyde novolac, 0-
Cresol formaldehyde/novolac polyglycidyl ether, butanediol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetra Glycidyl ether, polyglycidyl ether of sorbitol, and other polyfunctional epoxy compounds include epoxy compounds derived from aromatic dicarboxylic acids such as diglycidyl isophthalate, diglycidyl phthalate, diglycidyl ester of linole dimer acid, and Also included are triglycidyl isocyanurate, tetraphenylolethane epoxy, and the like. The reaction between the polyfunctional epoxy compound having two or more glycidyl groups and the carboxyl group-containing acrylic prepolymer is based on the number of moles of glycidyl groups in the polyfunctional epoxy compound and the number of moles of carboxyl groups in the carboxyl group-containing acrylic prepolymer. and in the range of 1:0.6 to 1:1.4, preferably 1:0.8 to
On the other hand, the blending ratio of carboxyl group-containing acrylic prepolymer and other carboxyl group-containing resin is 99 to 10 wt% of the former and 1 to 90 wt% of the latter, with glycidyl groups added as necessary. Or by adding a solvent that does not react with carboxyl groups, the reaction temperature is 80 to 180℃, preferably 100 to 160℃.
The reaction is carried out until the reaction rate as measured by the acid value of unreacted carboxyl groups in the carboxyl group-terminated acrylic prepolymer is 80% or more. For the reaction between the glycidyl group and the carboxyl group, for example, a base catalyst can be used as a reaction catalyst, if necessary. Examples of base catalysts include pyridine, isoquinoline, quinoline,
N,N-dimethylcyclohexylamine, α-picoline tri-n-butylamine, triethylamine, N-ethylmorpholine, N,N-dimethylaniline, N-(β-hydroxyethyl)amine,
Organic amines such as dimethyl coconut amine derived from N-ethyl-3,5-dimethylmorpholine and coconut oil, or inorganic alkalis such as caustic soda and caustic potash are used. The branched resin obtained by this method has improved compatibility with various resins, has a low viscosity of the resin itself, is a high non-volatile paint, and has excellent coating workability and film performance. available. However, since pigments used in paints do not have uniform surface characteristics, the branched resins described above may not always exhibit good dispersion performance depending on the pigment. Based on the fact that the surface properties of pigments are classified according to the concepts of acid and base, the present inventors used the above-mentioned branched resin and modified the pigment to be acidic or/and basic according to the surface properties. Taking into consideration the low viscosity properties and good compatibility of the resin itself, compared to the case of modifying ordinary acrylic resins, the dispersion performance of various pigments, especially dispersion speed, viscosity of dispersion paste, yield value, stability over time, and even paints are improved. It has been found that the composition has excellent characteristics in terms of color mixing stability under various conditions, non-volatile content during coating, coating workability, and color tone, gloss, and sharpness as a coating film. In branched resins for pigment dispersion having such excellent dispersion, paint, painting, and coating performance, (1) branched resins having electron-accepting groups contain acid anhydrides and/or Alternatively, free electron-accepting groups can be supported within the molecule by reacting with a sultone compound. On the other hand, (2) a branched resin having an electron-donating group is produced by copolymerizing a polymerizable basic compound monomer during the synthesis of a carboxyl group-containing acrylic prepolymer, and using a prepolymer that retains the base to form a branched resin. Obtained by synthesis. Furthermore, the active hydrogen contained in the branched resin and the optionally introduced active alkoxy group are reacted with a basic low molecular weight compound and/or basic resin having an active alkoxy group and/or active hydrogen. You can get it by twisting it. Furthermore, (3) the amphoteric branched resin having an electron-donating group and an electron-accepting group is
It can be easily obtained by combining with In addition, "active hydrogen" used in this specification
The term refers to primary, secondary and tertiary hydroxyl groups,
It refers to a highly reactive hydrogen atom bonded to oxygen, sulfur, nitrogen, etc. contained in an amide bond, urethane bond, carboxyl group, etc., and the term "active alkoxy group" refers to a highly reactive hydrogen atom bonded to oxygen, sulfur, nitrogen, etc. contained in an amide bond, urethane bond, carboxyl group, etc. "Functional group that reacts with active hydrogen" refers to highly reactive alkoxy groups such as substituted groups.
The term refers to primary, secondary and tertiary hydroxyl groups,
It refers to groups that easily react with active hydrogen, such as isocyanate groups and glycidyl groups, and the term "functional groups that react with active alkoxy" refers to groups that easily react with active alkoxy groups, such as primary, secondary, and tertiary hydroxyl groups. The term "electron-accepting group" refers to groups such as carboxyl, sulfone, and nitro groups that tend to withdraw electrons from others when hydrogen is the standard in the molecule. The term "basic resin" is usually used in the paint field to refer to groups that tend to donate electrons to others when hydrogen is the standard in the molecule, such as halogens and alkyls, because they have -N- which has a lone pair of electrons. Urea resins, melamine resins used in
The term "basic low molecular weight compound" refers to resins with basic groups such as polyamide resins and polyurethane resins, and also refers to hydroxylamine compounds (e.g. monoethanolamine, diethanolamine, aminopentanol) used as prepolymers or monomers of basic resins. , aminobenzyl alcohol, 2-dimethylaminoethanol, etc.), amino acids (e.g. 3-dimethylaminobenzoic acid, 2-dimethylaminobenzoic acid, etc.),
-amino-isobutyric acid, 4-amino-n-butyric acid, etc.)
etc. A detailed explanation of the manufacturing method of (A) a branched resin having an electron accepting group, (B) a branched resin having an electron donating group, and (C) an amphoteric branched resin having an electron accepting group and an electron donating group in this application. do. (A) In the synthesis of a branched resin having an electron-accepting group, an active hydrogen group-containing compound is used to synthesize the acrylic prepolymer having a carboxyl group and other resins having a carboxyl group. Active hydrogen groups may be retained in polymers and other resins, or acrylic prepolymers and other resins that do not retain active hydrogen groups may be used. The branched resin obtained by reacting these acrylic prepolymers having carboxyl groups and other resins having carboxyl groups with a polyfunctional epoxy compound has the formula: It holds a secondary hydroxyl group within the molecule and can be used as an active hydrogen group. In order to support an electron-accepting group on the branched resin that retains active hydrogen groups obtained by such a method,
Any compound can be used as long as it reacts with active hydrogen groups to generate free acidic groups, but
Typically, compounds that react with active hydrogen groups to produce carboxyl groups, acid anhydrides such as acetic anhydride, succinic anhydride, phthalic anhydride, maleic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride. Acids, trimellitic anhydride, etc., as well as compounds that react with active hydrogen groups to produce sulfonic acid groups, fatty acid sultones, such as 1,3-propanesultone, 1,3-butanesultone, 2,
4-butane sultone, 1,4-butane sultone,
It is also possible to use 1,3-octane sultone, 2,3-decane sultone, etc., or anhydrous inorganic acids such as metaphosphoric acid. In the addition reaction of such sultone compounds, a solution consisting of a branched resin and a fatty acid sultone is
A saltone-modified branched resin can be synthesized by reacting at a reaction temperature of 150°C for 2 to 10 hours. When synthesizing such a sultone-modified branched resin, the amount of sultone used when adding sultone is from 0.01 to 0.01 in solid weight ratio of the branched resin.
6% by weight, preferably in the range 0.02-4% by weight. If the amount used exceeds 6% by weight, the melt viscosity of the polymer increases, making it difficult to manufacture the polymer. On the other hand, in the synthesis of (B) a branched resin having an electron-donating group, a polymerizable basic compound,
For example, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, butylaminoethyl methacrylate, butylaminoethyl acrylate, 2-vinylpyridine, 4-vinylpyridine, 2-methyl5
-vinylpyridine, 2-ethyl 5-vinylpyridine, dimethylallylamine, diallylamine, vinylpyrroline, vinylisoquinoline, NN-dimethylaminoethyl vinyl ether, 2-(NN dimethylamino)4vinylpyrimidine, trans 1,2 dipyridylethylene, 3-thinner Moylpyridine, 2-methyl-5-cinnamoylpyridine,
By copolymerizing 4,6 diamino 2-vinyl 5-triazine or the like and synthesizing a branched resin using such a prepolymer, an electron donating group can be supported within the molecule. Alternatively, when synthesizing an acrylic prepolymer having a carboxyl group and other resins having a carboxyl group, an active alkoxy group-containing compound and/or an active hydrogen group-containing compound as needed may be copolymerized, and such prepolymers and other resins can be synthesized. The branched resin synthesized using this method is made to support active hydrogen and an active alkoxy group introduced as necessary, and the branched resin selected by this method is reacted with a low molecular weight basic compound and/or a basic resin. By this, a branched resin having an electron donating group can be synthesized. In addition, a polyvalent isocyanate compound or a glycidyl compound is blended and reacted with a branched resin carrying an active hydrogen group so that free isocyanate groups or glycidyl groups remain, and a basic resin and/or a basic low molecular weight It can also be a branched resin that can react with active hydrogen in the compound. As the basic resin, urea resins, melamine resins, polyamide resins, polyurethane resins, etc., which are commonly used in the paint field, are used. Urea resins and melamine resins are obtained by condensing urea or melamine with formaldehyde, and if necessary, alcohols (such as methyl alcohol,
Ethyl alcohol, propyl alcohol, butyl alcohol, etc.) can also be used as an alkylated methylol urea resin or an alkylated methylol melamine resin, using the resin as part of the raw materials for production. Polyamide resin is obtained by a condensation reaction of an aliphatic diamine and a dibasic acid, or a urea condensation reaction of a cyclic lactam.
1,2 ethanediamine, N,N'-dimethyl-1,
2-ethanediamine, 1,6-hexanediamine, etc., and dibasic acids such as succinic acid, adipic acid, and sebacic acid are appropriately selected. Examples of cyclic lactams include α-pyrrolidone,
δ-caprolactam, ω-capryllactam, etc. are used. In the above-mentioned production process, active hydrogen or active alkoxy groups are introduced into such basic resins along with electron-donating groups, which can be subjected to an addition or condensation reaction with the functional groups in the acidic resin (A). The above (A) branched resin having an electron accepting group and (B)
(C) A branched resin having an electron accepting group and an electron donating group can be synthesized by combining the techniques used in the synthesis of a branched resin having an electron donating group. The branched resins (A), (B), and (C) obtained in this way have lower viscosity at the same molecular weight than when ordinary resins are loaded with electron-accepting groups and/or electron-donating groups using the same method. It has the characteristic that it becomes low. In addition, by appropriately using branched resins (A), (B), and (C) according to the pigment surface characteristics, we have achieved superior dispersion, paint, coating, and coating performance compared to when ordinary resins are modified. It has a great effect. However, in the paint industry, a wide variety of inorganic and organic pigments are used and their surface properties are also very different. Even if we think of pigments in terms of acids and bases, their acidity and basicity vary widely. Therefore, it is naturally expected that the degree of acidity and basicity in the dispersing resin will vary from pigment to pigment if the optimum one is sought for each pigment. Therefore, the present inventors thought that it might be possible for the acidity and basicity of the dispersion resin to exhibit good dispersibility in terms of the greatest common denominator for many of the pigments that are widely used today.
Various pigments were actually dispersed in the above-mentioned dispersing resin, and the relationship between the acidity and basicity of the resin and the pigment dispersion effect was investigated. However, since there is no known simple method for measuring the acidity and basicity of amphoteric pigments in a non-aqueous system, the present inventors dissolved the sample dispersion resin in aniline and used n-tetrabutylammonium hydroxide. The acidity of the resin is determined from the number of moles of the reagent required for neutralization by non-aqueous potentiometric titration using a titration reagent, and the acidity of the resin is determined by non-aqueous potentiometric titration using perchloric acid as a titration reagent using an acetic acid solution of the sample. We have developed a unique method for measuring acidity and basicity in non-aqueous systems that determines basicity from the number of moles of reagent required for neutralization. I valued it. As a result of the test, the present inventors found that the acidity of the amphoteric dispersion resin was 1.0 to 1.0×10 ^-2 m mol/g.solid,
Particularly preferably 0.8 to 2.0×10 ^-2 m mol/g.solid
The basicity is in the range of 1.0 to 5×10 ^-3 m
mol/g.solid, particularly preferably 1.0 to 1×10 ^-2 m
It has been found through experience that when the amount is within the mol/solid range, good dispersibility is exhibited for various inorganic and organic pigments for paints. Therefore, in preferred embodiments of the present invention, resins exhibiting acidity and basicity within the above ranges in the test method described herein are preferably used. As a result of research, the present inventors found that the blending ratio in the reaction between the active hydrogen groups in the branched resin and the acid anhydride and/or sultone compound is 0.1 to 50% compared to 99.9 to 50% of the solid content of the resin. , most preferably 0.1-30% for 99.9-70%,
Furthermore, the blending ratio in the reaction between the branched resin supporting active hydrogen and the active alkoxy group introduced as necessary and the low molecular weight basic compound and/or basic resin is determined by the solid content of the resin.
99.9-50% to 0.1-50%, most preferably 99.9-70% to 0.1-30%, while
The weight ratio of the mixture in the reaction between the branched resin and the basic resin is 0.5 to 60%, most preferably 99.5 to 60%, relative to the solid content of the resin, which is 99.5 to 40%.
and 0.5 to 60%, the molecular weight of the obtained dispersion resin measured by gel permeation chromatography is 2000 to 200000, preferably 4000 to 100000 in terms of polystyrene, and the glass transition temperature is -
It has also been found that temperatures between 20 and 100°C, preferably between -10 and 80°C, give the best results. Therefore, in the most preferred embodiment of the present invention, a resin that satisfies the above various parameters in addition to the acidity and basicity of the dispersing resin is used for dispersing the pigment. The coating composition of the present invention can be obtained by dispersing various pigments using the dispersing resin specified herein. In this case, various inorganic and organic pigments commonly used in paints are used as pigments, such as carbon black, zinc white, titanium oxide, antimony white, iron black, Benkara, red lead, cadmium yellow, Zinc sulfide, lithopone, barium sulfate, lead sulfate, barium carbonate, lead white, alumina white, etc., and organic pigments include azo, polycondensed azo, metal complex azo, benzimidazolone, and phthalocyanine (blue). , green), thioindigo, anthraquinone, flavanthrone, indanthrene, anthrapyridine, pyranthrone, isoindolinone, perylene, perinone and quinacridone pigments are advantageously used. The blending ratio of the above dispersing resin and pigment is not critical and can be selected arbitrarily since it is further diluted with a resin or solvent when making a paint, but it is important to consider the economic efficiency of dispersion-based production, dispersion rate, etc. Considering,
Usually the ratio is 10-90% by weight of resin (solid content) and 90-10% by weight of pigment, preferably 30% by weight of resin (solid content).
~70% by weight of pigment and 70-30% by weight of pigment. The coating composition of the present invention comprises a dispersing resin carrying the above-described electron-accepting group and/or electron-donating group, and, if necessary, other resins such as acrylic resins, alkyd resins, polyester resins other than those of the present invention, One or more of polyether resin, cellulose nitrate, urethane resin, vinyl acetate resin, polyvinyl alcohol resin, vinyl chloride resin, phenol resin, melamine resin, guanamine resin, urea resin, epoxy resin, etc., and the above pigments. One or more kinds can be mixed together, and if necessary, a solvent commonly used in the paint industry, such as toluene,
Add one or more of hydrocarbon solvents such as xylene, Solbetsuso 100 and Solbetsuso 150, ester solvents such as ethyl acetate and butyl acetate, and ketone solvents such as MEK and MIBK, and use a conventional dispersion machine such as a roll mill dispersion machine. , ball mill dispersion machine, sand grind mill dispersion machine, planetary mixer,
Manufactured using a high-speed dispersion machine, etc. The coating composition thus obtained exhibits extremely good pigment dispersibility, excellent stability during storage, and excellent compatibility with various resins and solvents, making it extremely useful as a coating composition. The present invention will be explained below with reference to typical production examples and examples of the dispersing resin used in the present invention. By weight unless otherwise specified. Synthesis Example 1 (Branched resin incorporating a carboxyl group-containing acrylic prepolymer and a carboxyl group-containing alkyd resin) 24 parts of xylene and butyl acetate are placed in a reaction vessel equipped with a dropping roller, a cooling tube, a nitrogen introduction tube, a thermometer, and a stirring blade. Pour 200 parts and raise the temperature to 130℃. 45 parts of 2-hydroxyethyl methacrylate, 336 parts of methyl methacrylate, 60 parts of n-butyl acrylate,
A solution of 127 parts of styrene monomer, 3 parts of acrylic acid, and 10.8 parts of azobisisobutyronitrile is charged into a dropping funnel. The contents of the dropping funnel were added dropwise at a constant rate over 3 hours at 130°C under a nitrogen atmosphere. 30 minutes after completion of dripping
Hold at 130 °C for minutes. Next, a solution of 1.2 parts of azobisisobutyronitrile and 176 parts of xylene is charged into the dropping funnel. This is added dropwise at a uniform rate over 30 minutes. 1 hour after completion of dripping 130
The polymerization was completed by maintaining the temperature at ℃. dena call here
EX-411 13 parts, Furmin DMC 1.11 parts, and in-house alkyd resin α (Mn8500, Mw30000, acid value
0.2mgKOH/g solid content, OH value 55mgKOH/g solid content, heating residue 60%) 162 parts was prepared and heated for 9 hours at 130°C.
to hold. Then 115 parts of xylene, 115 parts of butyl acetate
The reaction was completed. After cooling, the contents were taken out to obtain a branched acrylic resin A incorporating an alkyd resin. The characteristics of the obtained resin are shown in Table-1. Synthesis Example 2 (Branched resin incorporating carboxyl-terminated acrylic prepolymer and carboxyl-containing alkyd resin) 24 parts of xylene was added to butyl acetate in a reaction vessel equipped with a dropping funnel, a cooling tube, a nitrogen introduction tube, a thermometer, and a stirring blade. Prepare 200 parts and raise the temperature to 130℃. 45 parts of 2-hydroxyethyl methacrylate, 336 parts of methyl methacrylate, 60 parts of n-butyl acrylate,
127 parts of styrene monomer, 6.5 parts of thioglycolic acid
A solution of 2.7 parts of azobisisobutyronitrile is charged into the dropping funnel. The contents of the dropping funnel were added dropwise at a constant rate over 3 hours at 130°C under a nitrogen atmosphere. After finishing dropping, keep at 130℃ for 30 minutes. Next, a solution of 0.3 parts of azobisisobutyronitrile and 176 parts of xylene is charged into the dropping funnel. This is added dropwise at a uniform rate over 30 minutes. After the dropwise addition was completed, the temperature was maintained at 130°C for 1 hour to complete the polymerization. Denacol EX-411 28 parts here, Fuamin
Add 1.11 parts of DMC and 275 parts of in-house alkyd resin α, and keep at 130°C for 9 hours. Then xylene
130 parts and 130 parts of butyl acetate were added to complete the reaction. After cooling, the contents were taken out to obtain a branched acrylic resin B. The characteristics of the obtained resin are shown in Table-1. Synthesis Example 3 (Acid-added branched resin) After cooling, 865 parts of the branched resin A synthesized by the method of Synthesis Example 1, 9.1 parts of phthalic anhydride, and 0.0 parts of DBTO were placed in a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirring blade. Pour 44 parts of the solution (manufactured by Wako Pure Chemical Industries, Ltd.) into a Kolben and raise the temperature to 130°C. After the temperature was raised, the temperature was maintained at 130° C. for 1 hour to complete the addition reaction, and acid addition branched resin C was obtained. The special numbers of C are shown in Table-2. Synthesis Example 4 (Acid-added branched resin) A phthalic anhydride-added branched resin was synthesized using the same method as in Synthesis Example 3 using the formulation shown in Table 2. Synthesis Example 5 (Base addition branched resin) 33 parts of xylene and 156 parts of butyl acetate are charged into a reaction vessel equipped with a dropping funnel, a cooling tube, a nitrogen introduction tube, a thermometer, and a stirring blade, and the temperature is raised to 130°C. 45 parts of 2-hydroxyethyl methacrylate, 336 parts of methyl methacrylate, 60 parts of n-butyl acrylate,
127 parts of styrene monomer, 11.5 parts of N,N dimethylaminoethyl methacrylate, thioglycolic acid
A solution of 6.5 parts of azobisisobutyronitrile and 2.7 parts of azobisisobutyronitrile is charged into the dropping funnel. The contents of the dropping funnel were dropped at a uniform rate over 3 hours at 130°C under a nitrogen atmosphere. After completion of dropping, keep at 130°C for 30 minutes. Then 0.3 part of azobisisobutyronitrile,
Charge a solution of 123 parts of xylene to the dropping funnel. This is added dropwise at a uniform rate over 30 minutes. 1 hour after completion of dripping
Hold at 130℃. Next, a solution of 17 parts of Denacol EX-411 (manufactured by Nagase Kasei Kogyo Co., Ltd.) and 1.44 parts of Furmin DMC was charged and kept at 130°C for 7 hours to complete the addition reaction, and then 144 parts of xylene and 144 parts of butyl acetate were added and cooled. A base-added branched resin E was obtained. The special values of E are shown in Table-3. Synthesis Example 6 (Acid/Base Addition Branched Resin) 665 parts of base addition branched resin E synthesized by the method of Synthesis Example 5, 9.1 parts of phthalic anhydride in a reaction vessel equipped with a cooling tube, nitrogen introduction tube, thermometer, and stirring blade. Department, DBTO
(manufactured by Wako Pure Chemical Industries, Ltd.) Pour 0.44 parts of the solution into a Kolben and raise the temperature to 130°C. After raising the temperature, it was maintained at 130°C for 1 hour to complete the addition reaction. The special properties of the acid/base addition branched resin F are shown in Table 4. Example 1 Patent filed by the present inventors in 1982-
2181273 showed a method for synthesizing a branched acrylic resin, and according to this method, the in-house alkyd resin α (carboxyl group-containing alkyd resin) was removed from the formulation shown in Synthesis Example 2 of this patent to create a branched acrylic resin β.
was synthesized. In order to investigate the compatibility between the in-house alkyd resin α and the branched resins (β, A, and B), we mixed the two resins well and applied a solution to a transparent glass plate using a 7 mil film applicator (Taiyu Kikai Co., Ltd.). Co., Ltd.) was used to prepare the resin film.
Next, after drying in a jet oven at 140°C for 1 hour, the resin film was evaluated after being cooled to room temperature. The evaluation results are shown in Table-5. From this result, it was observed that compatibility can be improved by introducing some alkyd resin molecules that cause problems in compatibility into a branched acrylic resin and configuring new molecules. Example 2 Patent filed by the present inventors in 1982-
2181273 shows a method for synthesizing an acid-added branched acrylic resin. After removing the in-house alkyd resin α from the formulation shown in Synthesis Example 2 of this patent according to this method, the acid-added branched acrylic resin was synthesized by adding an acid. Resin γ was synthesized. In-house alkyd resin α (carboxyl group-containing alkyd resin) and acid addition branched resin (γ, C and D)
The method of Example 1 was followed to examine the compatibility of . The evaluation results are shown in Table-6. From this result, it was observed that compatibility can be improved by introducing some alkyd resin molecules that cause problems in compatibility into a branched acrylic resin and configuring new molecules. Example 3 Branched resins B and D obtained in Synthesis Examples 2 and 4
Each pigment was dispersed using a paint shaker (Red Devil Co., Ltd.) according to the dispersion formulation shown in Table 7, and the specular gloss (Murakami gloss meter GM-26D model) of the dispersed product was measured. Further, the viscosity of each of the obtained dispersion pastes was measured using a cone-plate viscometer (E-type viscometer manufactured by Tokyo Keiki Co., Ltd.), and the results shown in Table 7 were obtained.
From these results, it is observed that when an acid-added branched resin is used, the viscosity of the dispersed paste becomes about 1/3 of that of a branched resin that has almost no acid, in the case of phthalocyanine blue. In addition, the gloss is about 30% in the case of phthalocyanine blue.
It is observed that it is increasing.

【table】

【table】

【table】

【table】

【table】

【table】

[Table] Evaluation criteria: ○...Transparent, no shrinkage
×…Cloudy, shrinkage

【table】

Claims (1)

[Claims] 1 formula (In the formula, R is an n+m-valent aliphatic, alicyclic, aromatic, or heterocyclic hydrocarbon residue;
acrylic prepolymer chain; Y is polyester;
Prepolymer chains of alkyd, polyether, polyurethane or epoxy resin; m and n are each m+
n is a real number from 2 to 6), and has a weight average molecular weight (gel permeation chromatography measurement,
Polystyrene equivalent) 2000 to 200000, branched resin with a glass transition temperature of -20℃ to 100℃, acrylic resin,
A resin composition for paints comprising at least one base resin for paints selected from the group consisting of polyester resins, alkyd resins, polyether resins, polyurethane resins, and epoxy resins.