JPH0347667B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Background and Problems of the Invention Electrodeposition paints are widely used as undercoats with anticorrosive properties because of their workability regardless of shape and their safety. Electrodeposition paints are in the form of resins dispersed or dissolved in water as a medium, so controlling their stability and throwing power through energization is necessary to stabilize the coating line. Regarding its performance as a coating film, coating films with high film thickness and high performance physical properties are desired, particularly in fields such as automobile coating systems, where high corrosion resistance and chipping properties are required. In addition, as consumers have recently become more conscious of high-quality products, there has been a strong desire for high-quality paint films, and there is a strong need for paint films that have higher definition and higher gloss than ever before. Conventionally, in electrodeposition paints, especially emulsion-based electrodeposition paints, phase separation of the base resin itself has often been a problem. Possible methods to reduce the tendency for phase separation include the use of surfactants and increasing the number of hydrophilic groups introduced into the base resin, but these methods do not affect coating performance, such as water resistance. and has a negative effect on corrosion resistance. Therefore, it is an object of the present invention to improve the dispersion stability of the base resin without sacrificing the coating performance or adversely affecting other performances of the electrodeposition paint. Solution The above-mentioned problem is solved by adding a material having a relatively small particle size to an aqueous dispersion of an aqueous resin (base resin) that can be electrodeposited.
This problem is solved by adding fine resin particles having an SP value relatively close to the solubility parameter (hereinafter referred to as "SP") value of the base resin. Therefore, the present invention provides (a) an aqueous dispersion of an aqueous resin that can be electrodeposited; Provided is an electrodeposition coating composition characterized in that it contains as an essential component fine resin particles having an SP value difference of 1 or less from that of the resin. Because the micro resin particles are small, they adhere to the surface of the aqueous resin emulsion particles in the paint liquid and modify their charge state, improving the dispersion stability of the emulsion particles. Since it has high compatibility with the paint, it is stably dispersed in the paint, contributing to improving the stability of the paint as a whole. Since the fine resin particles become part of the film-forming resin component, they do not adversely affect other properties of the paint or coating film. In the present invention, the solubility parameter is KW
SUH, JMCORBETT: Journal of Applied
Science, 12, 2359 ('68). Specifically, non-solvents (water with a high SP and n-hexane with a low SP) are added to an acetone solution of a sample, and the amount of non-solvent required to cause turbidity is determined. At this time, the SP of the sample is calculated by the formula: SP = (√ _o- hexane × SP _o- hexane + √ water × SP water) / (√ _o- hexane + √ water) [In the formula, V _o- hexane = Volume of n-hexane, SP _o- hexane = SP of n-hexane, V
Water = Volume of water until turbidity and SP Water = SP of water. ] Find it from . Detailed Discussion Electrodepositable Water-Based Resins The present invention is applicable to both cationic and anionic electrodeposition coatings. Electrodepositable aqueous resins (base resins) are generally film-forming resins that have functional groups that provide the charge and hydrophilicity necessary for electrodeposition. They are classified into aqueous solution type, dispersion type, emulsion type, and suspension type, mainly depending on their form when dispersed in water, and herein they are collectively referred to as aqueous resin. Various types of water-based resins are known for use in electrodeposition paints, and any of these known water-based resins can be used in the present invention. The water-based resin used in anionic electrodeposition paints has anionic functional groups such as carboxyl groups in order to give the resin the negative charge and hydrophilicity necessary for electrodeposition. Typical such resins are maleated natural or synthetic drying oils, maleated polybutadiene, half esters, half amides thereof, and the like. The water-dispersible resin used in cationic electrodeposition paints has cationic functional groups such as amino groups to give it positive charge and hydrophilicity. Examples of such resins include epoxies, polyethers, polyesters, polyurethanes, polyamides,
Various types such as polybutadiene type are known. Depending on the mechanism of the curing reaction, these resins can be of the self-crosslinking type, in which the resin itself is cured by radical polymerization or oxidative polymerization, or in combination with a curing agent, such as a melamine resin or a block polyisocyanate compound. There are curing agent types that harden when used in combination, and types that use both in combination. Furthermore, according to the type of curing energy, it can be classified into types such as room temperature curing, heat curing, and radiant energy curing such as ultraviolet rays and electron beams. Furthermore, for the purpose of improving coating film performance, resins that do not have functional groups that impart charge and hydrophilicity, such as epoxy acrylate resins, are used in combination with the hydrophilic resins in the form of emulsions. In the present invention, a system in which such a curing agent is used in combination with a resin having no hydrophilic functional group is also referred to as an aqueous resin. Such electrodepositable aqueous resins are well known to those skilled in the art and do not require further explanation as such do not form part of the present invention. Micro resin particles Various methods have been proposed to produce micro resin particles, one of which involves suspending ethylenically unsaturated monomers and/or crosslinkable comonomers in an aqueous medium. A fine resin particle dispersion is obtained by polymerization or emulsion polymerization.Other methods use low SP organic solvents such as aliphatic hydrocarbons or high SP organic solvents such as esters, ketones, alcohols, etc.
The ethylenically unsaturated monomer and/or crosslinkable copolymer are non-polymerized in a non-aqueous organic solvent that dissolves the monomer but not the polymer, like an organic solvent, and the resulting fine resin particle copolymer is Spread
This method is called the NAD method or precipitation method. The fine resin particles of the present invention may be produced by any of the above methods. Examples of ethylenically unsaturated monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)allylate, isobutyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. Alkyl esters of acrylic acid or methacrylic acid and other monomers having ethylenically unsaturated bonds that can be copolymerized with them, such as styrene,
Examples include α-methylstyrene, vinyltoluene, t-butylstyrene, ethylene, propylene, vinyl acetate, vinyl propionate, acrylonitrile, methacrylonitrile, dimethylaminoethyl (meth)acrylate, and the like. Two or more types of these monomers may be used. The crosslinkable copolymerizable monomer is a monomer having two or more radically polymerizable ethylenically unsaturated bonds in the molecule and/or two types of ethylenically unsaturated monomers each carrying mutually reactive groups. Contains group-containing monomers. Examples of monomers having two or more radically polymerizable ethylenically unsaturated groups in the molecule include polymerizable unsaturated monocarboxylic acid esters of polyhydric alcohols;
Examples include polymerizable unsaturated alcohol esters of polybasic acids and aromatic compounds substituted with two or more vinyl groups, examples of which include the following compounds. Ethylene glycol diacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 1,4-butanediol dimethacrylate acrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate,
Pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, glycerol dimethacrylate,
Glycerol diacrylate, glycerol allyloxy dimethacrylate, 1,1,1-trishydroxymethylethane diacrylate, 1,1,
1-trishydroxymethylethane triacrylate, 1,1,1-trishydroxymethylethane dimethacrylate, 1,1,1-trishydroxymethylethane trimethacrylate, 1,1,
1-trishydroxymethylpropane diacrylate, 1,1,1-trishydroxymethylpropane triacrylate, 1,1,1-trishydroxymethylpropane dimethacrylate, 1,
1,1-trishydroxymethylpropane trimethacrylate, triallyl cyanurate, triallyl isocyanurate, triallyl trimellitate, diallyl terephthalate, diallyl phthalate and divinylbenzene. In addition, two groups each carrying a group that can react with each other
Examples of monomers having ethylenically unsaturated groups include epoxy group-containing ethylenically unsaturated monomers such as glycidyl acrylate and glycidyl methacrylate, and carboxyl group-containing ethylenically unsaturated monomers such as acrylic acid, methacrylic acid, and crotonic acid. Monomers are the most representative, but mutually reactive groups are not limited to these.
For example, various compounds have been proposed, such as amine and carbonyl, epoxide and carboxylic acid anhydride, amine and carboxylic acid chloride, alkyleneimine and carbonyl, organoalkoxysilane and carboxyl, hydroxyl and isocyanate, etc., and the present invention broadly encompasses these. It is something to do. Fine resin particles produced in an aqueous medium or a non-aqueous organic medium can be isolated by a method such as filtration, spray drying, or freeze drying, and then they can be reduced to an appropriate particle size using a mill or the like. It can be used after being pulverized, or the synthesized dispersion can be used as it is or by replacing the medium by solvent replacement. Generally, it is desirable to control the particle size of the particles obtained by the polymerization method. 0.01
Emulsion polymerization method and NAD method are suitable for particles of ~0.2μ. The SP value of the fine resin particles can be controlled by the composition of the monomer mixture. In particular, in the case of copolymers of ethylenically unsaturated monomers, it can be determined by calculation from the types of monomers and their proportions. In order to maintain a stable dispersion state in the paint and the electrodeposition bath, the fine resin particles preferably have ionizable groups of the same polarity as the aqueous resin which is itself a base resin. That is, in the case of anionic electrodeposition, it is preferable to support an anionic group such as a carboxyl group or a sulfonic acid group, and in the case of cationic electrodeposition, it is preferable to support a cationic group such as an amino group or a quaternary ammonium group. To achieve this, monomers having an ethylenically unsaturated bond and a carboxyl group, such as acrylic acid and methacrylic acid, and monomers having an ethylenically unsaturated bond and a basic group, such as dimethylaminoethyl (Meth)acrylates, vinylpyridines, etc. are added to the monomer mixture during the synthesis of minute resin particles, or the monomer mixture is polymerized using an initiator that provides a cationic end for the synthesis of minute resin particles. There is a way. If the polymer itself that makes up the micro resin particles is non-polar, use an appropriate emulsifier during synthesis of the micro resin particles, especially oligosoaps, polysoaps, or reactive emulsifiers that have amphoteric ionic groups to stably disperse the micro resin particles. You can also do so. These emulsifiers having zwitterionic groups were disclosed in Japanese Patent Application Laid-Open No.
56-24461, 57-21927, 57-40522, etc. Electrodeposition Coating Composition The electrodeposition coating composition of the present invention contains the electrodepositable aqueous resin and the fine resin particles as essential components. The ratio of aqueous resin and fine resin particles is 1 to 50% by weight of the former as solid content.
It is. If the amount of fine resin particles added is too small, there will be no effect, and if it is too large, the stability of the paint and the workability of electrodeposition will be impaired. Depending on the type of water-dispersible resin used, auxiliary hardeners such as melamine resins, benzoguanamine resins, phenolic resins, blocked polyisocyanate compounds, manganese, cobalt, copper, lead, etc.
These components, which may include metal compounds such as tin as catalysts, are dispersed in an aqueous medium containing a base for anionic electrodeposition and an acid for cationic electrodeposition. These acids and bases are used to neutralize the electrodepositable water-soluble resin. Examples of the base used for neutralization include ammonia, diethanolamine, triethanolamine, methylethanolamine, diethylamine,
Examples include morpholine and potassium hydroxide. As the acid, phosphoric acid, acetic acid, propionic acid, lactic acid, etc. are used. The aqueous medium is water or a mixture of water and a water-miscible organic solvent. If necessary, the aqueous medium may contain a water-immiscible organic solvent. Examples of water-miscible organic solvents include ethyl cellosolve, propyl cellosolve, butyl cellosolve, ethylene glycol dimethyl ether, diacetone alcohol, 4-
Examples include methoxy-4-methylpentanone-2 and methyl ethyl ketone. Examples of water-immiscible organic solvents include xylene, toluene, methyl isobutyl ketone, and 2-ethylhexanol. The coating composition of the present invention can contain pigments. Examples include titanium dioxide, red iron,
There are coloring pigments such as carbon black, extender pigments such as aluminum silicate and precipitated barium sulfate, and rust-preventing pigments such as aluminum phosphomolybdate, strontium chromate, basic lead silicate, and lead chromate. The coating composition of the present invention has a non-volatile content of the coating of 10 to 10%.
Adjust to about 20% and electrodeposit to a dry film thickness of 15 to 30μ.
Depending on the type of resin, it can be cured by room temperature curing, heat curing, ultraviolet curing, electron beam curing, etc. Production examples, examples, and comparative examples of the present invention are shown below. Parts and percentages in these examples are by weight. Production example 1 Production of cationic micro resin particles 73.5 parts of sodium salt of taurine and ethylene glycol were placed in a 2-kolben equipped with a stirrer, nitrogen inlet tube, temperature control device, condenser, and decanter.
100 parts ethylene glycol monomethyl ether
Prepare 200 parts and heat while stirring to bring the temperature up.
Raise to 120℃. After the contents reach a uniform state of dissolution, use Epicote 1001 (manufactured by Ciel Chemical Co., Ltd.,
A solution consisting of 470 parts of a diglycidyl ether type epoxy resin of bisphenol A (epoxy equivalent: 470) and 400 parts of ethylene glycol monomethyl ether was added dropwise over 2 hours. After dropping, stirring and heating were continued for 20 hours to obtain 518 parts of modified epoxy resin. The acid value of this resin by KOH titration was 49.4, and the sulfur content by fluorescent X-ray analysis was 2.8%. In a reaction vessel equipped with a stirrer, a cooling tube, and a temperature control device, 306 parts of deionized water, 7.5 parts of the modified epoxy resin obtained above, and 1.0 parts of dimethylethanolamine were added.
The mixture was heated to 80°C while stirring. After the contents have dissolved, the temperature is maintained at 8°C while stirring, and 4.8% of azobiscyanovaleric acid is added to this.
85.7 parts of styrene, 114.3 parts of methyl methacrylate, n.
A mixed solution consisting of 28.6 parts of -butyl acrylate, 57.1 parts of n-butyl methacrylate, and 14.3 parts of diethylaminoethyl methacrylate was added dropwise over 60 minutes. After dropping, a mixed aqueous solution consisting of 1.2 parts of azobiscyanovaleric acid, 11.4 parts of dimethylethanolamine, and 12 parts of deionized water was added at the same temperature, and stirring was continued for 60 minutes to obtain a particle size of 128 nm and SP value.
10.1. A fine resin dispersion with a non-volatile content of 35% was obtained. Production example 2 Nisseki polybutadiene B-2000 (number average molecular weight
2000, 1, 2 bonds (65%) was epoxidized using peracetic acid to produce epoxidized polybutadiene with an oxirane oxygen content of 6.4%. After charging 1000 g of this epoxidized polybutadiene and 354 g of ethyl cellosolve into two autoclaves, 62.1 g of dimethylamine was added, and the mixture was heated to 150°C.
The reaction was carried out for 5 hours. After distilling off the unreacted amine,
After cooling to 120°C, a mixture of 79.3 g of acrylic acid, 7.6 g of hydroquinone and 26.4 g of ethyl cellosolve was added, and the mixture was further reacted at 120°C for 3 hours and 45 minutes to produce a resin solution (A). The amine value of this substance is
85.2 mmol/100g, acid value 10.0 mmol/100
g, and the solid content concentration was 75.0% by weight. Production example 3 1000 g of bisphenol type epoxy resin (trade name Epicote 1004 manufactured by Yuka Ciel Epoxy Co., Ltd.) with an epoxy equivalent of 950 was added to ethyl cellosolve.
343 g, 76.3 g of acrylic acid, 10 g of hydroquinone, and 5 g of N,N-dimethylaminoethanol were added, and the mixture was heated to 100° C. and reacted for 5 hours to synthesize a resin solution (B). Solid content concentration 75% by weight Production example 4 Nisseki polybutadiene B-1000 (number average molecular weight
1000, 1, 2 bonds 60%) 1000g, maleic anhydride
265.8 g, xylene 10 g, and Antigen 6C (Sumitomo Chemical brand name) 1 g were placed in two separable flasks equipped with a reflux condenser and heated at 190°C under a nitrogen stream for 50 minutes.
After reacting for an hour, unreacted maleic anhydride and xylene were distilled off under reduced pressure, and the acid value was 214 mmol/100 g.
A maleated polybutadiene was synthesized. Next, 1000 g of maleated polybutadiene and 212.4 g of ethyl cellosolve were charged into a two-separable flask equipped with a reflux condenser and reacted with stirring at 120° C. for 2 hours to produce a half-esterified product (C) of maleated polybutadiene. Solid content concentration 98% by weight Example 1 400 g of (A) produced in Production Example 2, 240 g of (B) produced in Production Example 3, and 19.2 g of (C) produced in Production Example 4
g was mixed until homogeneous. Varnish SP value
10.6. Thereafter, 8.1 g of acetic acid was added and thoroughly stirred for neutralization. 1835 g of deionized water was gradually added to this varnish to obtain an emulsion with a solids concentration of about 20%. Thereafter, 200 g of the fine resin dispersion of Production Example 1 was added to prepare an aqueous solution having a solid content concentration of approximately 20% (solid content of fine resin particles in the paint bath was approximately 3%). Cathode deposition type electrodeposition coating was performed using the above electrodeposition coating liquid at 100V for 3 minutes using the carbon electrode as the anode and the zinc phosphate treated plate as the cathode. Baking at 175℃ x 30 minutes.
The test results are shown in Table-1. Production example 5 Quaternary ammonium group-containing resin E 1800-6.5 (Nippon Petrochemical Co., Ltd., epoxidized polybutadiene) 1000 g Butyl cellosolve 349 g Dimethylamine 46 g 50% lactic acid 138 g Deionized water 473 g Phenyl glycidyl ether 117 g Epoxidized polybutadiene E1800 After charging −6.5 and butyl cellosolve into the autoclave,
Dimethylamine was added and reacted at 150°C for 5 hours.
After distilling off the unreacted amine, it was cooled to 60°C and heated to 50°C.
at 80 °C after adding a mixture of % lactic acid and deionized water.
Stir and keep warm for 30 minutes. After that, phenyl glycidyl ether was added, the temperature was raised to 110℃, and while stirring and keeping warm, the acid value of the contents was measured by the usual method using phenolphthalene as an indicator and alcoholic KOH as a standard solution, and the acid value was 0.1 or less. After allowing the reaction to occur, production is terminated. Non-volatile content 55% Production Example 6 Pigment Paste Production Example 5 Varnish 231g Deionized water 315g Carbon black 16g Titanium oxide 92g Kaolin 220g Basic lead silicate 58g After adding deionized water to the varnish of Production Example 5 and dissolving it, add the pigment. Stir and mix with a dispenser for about 1 hour. After glass beads are added to this mixture, they are dispersed in a sand mill to a particle size of 20 μm or less, and the production is completed after the glass beads are separated. Non-volatile content 55% Example 2 After mixing 400 g of (A) produced in Production Example 2, 240 g of (B) produced in Production Example 3, and 19.2 g of (C) produced in Production Example 4 until uniform (varnish SP value of
10.6), 8.1 g of acetic acid was added and thoroughly stirred to neutralize. 1835 g of deionized water was gradually added to this varnish to obtain an emulsion with a solids concentration of about 20%. After that, 360 g of the pigment paste of Production Example 6, 550 g of deionized water, and 260 g of the fine resin particle dispersion of Production Example 1 were added.
was stirred uniformly to prepare an enamel electrodeposition bath (solid content of fine resin particles in the paint: about 2%). Table 1 shows the performance of the coating film electrodeposited and cured using this electrodeposition bath under the same conditions as in Example 1. Production example 7 Nisseki polybutadiene B-1500 *(1) 1000g Antigen 6C *(2) 10g Maleic anhydride 250g Deionized water 20g Diethylamine 0.5g Propylene glycol 100g Ethyl cellosolve 340g *(1) Made by Nippon Petrochemical Co., Ltd.; Mn1500, vinyl 65
%, trans 14%, cis 16% *(2) Manufactured by Sumitomo Chemical Co., Ltd.; N-methyl-N'-(1,3
-dimethylbutyl), p-phenylenediamine In a 2-colben equipped with a cooling tube, 1000g of Nisseki Polybutadiene B-1500 was charged, and Antigen 6C
Add 10 g and 250 g of maleic anhydride. The addition reaction of maleic acid to polybutadiene is carried out while stirring and maintaining the internal temperature at 190 to 200°C.
Approximately 5 hours after the temperature was raised, it was confirmed that the reaction was completed by a dimethylaniline color reaction. Then check the internal temperature
Cool to 100° C. and add dropwise a mixture of 20 g deionized water and 0.5 g diethylamine over about 30 minutes.
After addition, stirring was continued for approximately 1 hour until the acid value
Confirmed that it is 140. Thereafter, 100 g of propylene glycol was added and reacted at 110° C. for 3 hours, and the total acid value was confirmed to be 125. Thereafter, 340 g of ethyl cellosolve was added and the mixture was stirred at 80° C. for about 1 hour, and then the synthesis was completed. Non-volatile content 80% Production example 8 Epotote YD-014 * (3) 950g Ethyl cellosolve 240g Hydroquinone 10g Acrylic acid 65g Dimethylbenzylamine 5g *(3) Manufactured by Toto Kasei Co., Ltd., epoxy resin, epoxy equivalent 950 2 Kolben with cooling tube ni epo tote YD−
014 Prepare 950g and 240g of ethyl cellosolve,
Dissolve YD-014 uniformly while stirring gradually to 120°C. Then add 10 g of hydroquinone, and further add 65 g of acrylic acid and 5 g of dimethylbenzylamine. After reacting at 120°C for 4 hours, it was confirmed that the post-acid value was 1 or less. Non-volatile content
80% Production Example 9 Production of Fine Resin Particles 426 parts of deionized water was placed in a flask equipped with a stirrer and a thermometer, and the temperature was heated to 80°C. An aqueous solution consisting of 1 part of ammonium persulfate and 20 parts of deionized water was added dropwise under a nitrogen stream. In addition, 5 parts of styrene,
After adding a monomer mixture consisting of 5 parts of n-butyl acrylate and reacting for 10 minutes, an aqueous solution consisting of 1 part of ammonium persulfate and 20 parts of deionized water,
A monomer mixture consisting of 40 parts of methyl methacrylate, 20 parts of n-butyl methacrylate, 30 parts of styrene and 10 parts of 2-hydroxyethyl methacrylate was added dropwise over 60 minutes. Furthermore, the temperature is 80℃
The mixture was kept warm for 2 hours to complete the reaction. A fine resin particle dispersion having a particle size of 196 nm, an SP value of 10.1, and a non-volatile content of 35% was obtained. Production Example 10 Pigment Paste 125g of the varnish from Production Example 7 was taken, 13g of triethylamine was added thereto, and then 250g of deionized water was added.
Gradually add g to dissolve it uniformly to make a varnish with a non-volatile content of 26%. Next, 150g of titanium dioxide, 50g of lead silicate, 25g of strontium chromate, and 25g of carbon black.
Add g and stir with a disperser for about 1 hour. After glass beads are added to this mixture, they are dispersed in a sand mill to a particle size of 20μ or less, and after the glass beads are separated, the production is completed. Non-volatile content 55% Example 3 125g of varnish from Production Example 7, 75g of varnish from Production Example 8
g, butylated melamine (50% non-volatile content), 40 g of resol type phenolic resin (50% non-volatile content) were collected, and 2 g of nonionic surfactant (SP value of varnish 10.5) and 3 g of cobalt naphthenate were added thereto and mixed uniformly. After stirring, 13 g of triethylamine was added, and then 707 g of deionized water was gradually added and dissolved by stirring uniformly. 47 g of the fine resin particle dispersion of Production Example 9 was added, and the solid content was approximately 20% (paint concentration). A paint bath was prepared in which the solid content of fine resin particles was approximately 2%. A dull steel plate treated with zinc phosphate was immersed in a paint bath, and electrodeposition was applied to a film thickness of 20 μm using the object to be coated as an anode. After that, the surface of the object to be coated is washed with water and placed in a baking oven.
Baking was performed at 140°C for 30 minutes to obtain a coated board with a film thickness of approximately 20μ. Table 1 shows the results of testing the performance of the obtained coating film.
Shown below. Example 4 125g of varnish from Production Example 7, 75g of varnish from Production Example 8
g, butylated melamine (50% non-volatile content), 40 g of resol type phenolic resin (50% non-volatile content) were collected, and 2 g of nonionic surfactant (SP value of varnish 10.5) and 3 g of cobalt naphthenate were added thereto and mixed uniformly. After stirring, 13 g of triethylamine was added, and then 707 g of deionized water was gradually added while stirring uniformly to dissolve. Next, 125 g of the pigment paste of Production Example 10, 220 g of deionized water, and the fine resin particle dispersion of Production Example 9 were added. 80 g of the liquid was uniformly stirred to prepare an enamel electrodeposition bath (the solid content of fine resin particles in the paint was approximately 2%). Table 1 shows the performance of the coating film electrodeposited and cured using this electrodeposition bath under the same conditions as in Example 3. Comparative Example 1 The same procedure as in Example 1 was carried out except that 200 g of the fine resin particles of Production Example 1 were not added and 1835 g of deionized water was changed to 1800 g. Comparative Example 2 The same procedure as in Example 2 was carried out except that 260 g of the fine resin particles of Production Example 1 were not added and 1835 g of deionized water was changed to 1800 g. Comparative Example 3 The same procedure as in Example 3 was carried out except that 60 g of the fine resin particles of Production Example 9 were not added and 707 g of deionized water was changed to 662 g. Comparative Example 4 The same procedure as in Example 4 was carried out except that 80 g of the fine resin particles of Production Example 10 were not added and 707 g of deionized water was changed to 662 g. Production Example 11 In Production Example 1, the same monomer mixture was added to 180
The process was carried out in the same manner as in Preparation Example 1, except that the dropwise addition took several minutes, and that stirring was continued for 180 minutes after adding an additional amount of the mixture of azobiscyanovaleric acid, dimethylethanolamine, and deionized water. A fine resin particle dispersion having a particle size of 0.35μ, an SP value of 10.1, and a non-volatile content of 35% was obtained. Production Example 12 The same procedure as in Production Example 1 was carried out except that the monomer mixture was made of 184.9 parts of methyl methacrylate, 100.7 parts of 2-hydroxyethyl methacrylate, and 14.3 parts of diethylaminoethyl methacrylate. A fine resin particle dispersion having a particle size of 0.156μ, an SP value of 12.0, and a non-volatile content of 35% was obtained. Comparative Example 5 Micro resin particle dispersion liquid of Production Example 1 in Example 1 200
200 g of the fine resin particle dispersion of Production Example 11 instead of
The same procedure as in Example 1 was carried out except that g was added. Comparative Example 6 Micro resin particle dispersion liquid of Production Example 1 in Example 1 200
The same procedure as in Example 1 was carried out except that 200 g of the fine resin dispersion of Production Example 12 was added instead of 200 g. 【table】

Claims (1)

[Scope of Claims] 1. (a) an aqueous dispersion of an aqueous resin capable of electrodeposition; (b) a particle having a particle size of 0.01 to 0.2μ uniformly dispersed in the aqueous dispersion of the aqueous resin, and An electrodeposition coating composition comprising, as an essential component, fine resin particles having a solubility parameter value difference of 1 or less from the aqueous resin. 2. The electrodeposition coating composition according to item 1, wherein the aqueous dispersion of the electrodepositable aqueous resin is an emulsion. 3 The aqueous resin has a cationic group.
The electrodeposition coating composition according to item 1 or 2. 4 The aqueous resin has a first aqueous resin having an anionic group.
The electrodeposition coating composition according to item 1 or 2. 5 Items 1 to 4, wherein the amount of the fine resin particles is 1 to 50% by weight of the solid content of the aqueous resin.
The electrodeposition coating composition according to any one of paragraphs.