JP2003049112A - Anionic electrodeposition coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anionic electrodeposition coating composition having excellent storage stability and readily regulating the gloss of finish. SOLUTION: This anionic electrodeposition coating composition comprises an acrylic resin (I) obtained by copolymerizing a compound (a) having >=2 polymerizable unsaturated groups in one molecule with a hydroxy group- containing polymerizable unsaturated monomer (b), a carboxy group-containing polymerizable unsaturated monomer (c) and other polymerizable unsaturated monomers (d) and a melamine resin and/or a blocked isocyanate as a cross- linking agent (II).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anionic electrocoating composition having excellent storage stability and easy control of the matte finish.

[0002]

2. Description of the Related Art At present, an anion type matte electrodeposition paint having a good finish is coated on an object to be coated such as an aluminum sash. As such an anion type matte electrodeposition coating composition, for example, JP-B-62-245
No. 19, etc., discloses a method in which an acrylic copolymer having an alkoxysilyl group is used as a base resin and an amino resin is used as a curing agent. In this method, since the acrylic copolymer used as the base resin has an alkoxysilyl group in the side chain, this is gradually hydrolyzed when the acrylic copolymer is made water-soluble (or water-dispersed). To produce silanol (Si—OH), and the condensation of the silanols produces a siloxane bond to form fine dispersion particles having an intraparticle gel structure. As a result, when this product is subjected to anion electrodeposition coating, a coating film with a fine rough surface is formed, and even if this coating is baked and cured, the coating film does not completely melt and maintain the rough surface, resulting in a good matte finish. Since it forms a coating film, it is widely used in the art.

However, with this coating composition, the gloss of the coating film obtained varies depending on the coating conditions, it is difficult to control the degree of matting, and the acrylic copolymer itself having an alkoxysilyl group as the base resin is used. There was a problem of poor storage stability.

On the other hand, Japanese Patent Laid-Open No. 3-139574,
Japanese Patent Application Laid-Open No. 5-263296 proposes a coating composition comprising an acrylic copolymer and crosslinkable resin particles. With this method, it is possible to control the desired matteness and the physical properties of the electrodeposition coating film by combining the acrylic copolymer and the crosslinkable resin particles, but if the finish has low gloss, a large amount of crosslinkability is required. Since it is necessary to add resin particles, there is a problem that the coating film performance such as adhesion and hardness becomes insufficient.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors use an acrylic resin obtained by copolymerizing a compound having two or more polymerizable unsaturated groups in one molecule. The inventors have found that the above-mentioned problems can be solved by this and completed the present invention. That is, the present invention is: Compound (a) having two or more polymerizable unsaturated groups in one molecule, hydroxyl group-containing polymerizable unsaturated monomer (b), carboxyl group-containing polymerizable unsaturated monomer (c), and other polymerizations 1. An anionic electrodeposition coating composition containing an acrylic resin (I) obtained by copolymerizing a polar unsaturated monomer (d) and a melamine resin and / or a blocked isocyanate as a crosslinking agent (II). The acrylic resin (I) contains 0.5 to 10% by weight of the compound (a) having two or more polymerizable unsaturated groups in one molecule and 5 to 30% of the hydroxyl group-containing polymerizable unsaturated monomer (b). %, A carboxyl group-containing polymerizable unsaturated monomer (c) in an amount of 1 to 20% by weight, and another polymerizable unsaturated monomer (d) in an amount of 40 to 93.5% by weight. The anionic electrodeposition coating composition according to item 1, which is 3. The weight average molecular weight of the acrylic resin (I) is 5,000
3. The anionic electrocoating composition according to item 1 or 2, which is 0 to 150,000. Further, items 1 to 3 containing the emulsion polymer (III).
An anion type electrodeposition coating composition according to any one of items
Regarding Hereinafter, the present invention will be described in detail.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Acrylic resin (I) The acrylic resin (I) in the present invention is a compound (a) having two or more polymerizable unsaturated groups in one molecule, a hydroxyl group-containing polymerizable unsaturated monomer. It is obtained by copolymerizing (b), the carboxyl group-containing polymerizable unsaturated monomer (c), and the other polymerizable unsaturated monomer (d).

In the present invention, examples of the compound (a) having two or more polymerizable unsaturated groups in one molecule include allyl (meth) acrylate and ethylene glycol di (meth).
Acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol diacrylate, glycerin di (Meth) acrylate, glycerin tri (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol di (meth) acrylate,
Pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, hydroxyisocyanurate tri (meth) acrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, glycerol Aryloxydi (meth) acrylate, 1,1,1-tris (hydroxymethyl) ethanedi (meth) acrylate, 1,1,1
-Tris (hydroxymethyl) ethane tri (meth) acrylate, triallyl isocyanurate, triallyl trimellitate, diallyl terephthalate, diallyl phthalate, diallyl isophthalate, pentaerythritol diallyl ether, divinylbenzene and the like. The copolymerization of this compound causes the acrylic resin (I) to have an appropriately high molecular weight and multi-branching. As a result, when the acrylic resin (I) and the below-mentioned crosslinking agent (II) (particularly a hydrophobic compound) are dispersed in water, the acrylic resin (I)
The dispersibility of the above in the cross-linking agent (II) is improved, and the water dispersion stability can be improved.

In the present invention, when a melamine resin is used as the crosslinking agent (II), the use of triallyl isocyanurate as the compound (a) improves the affinity between the acrylic resin (I) and the crosslinking agent (II). However, it is particularly preferable because the water dispersion stability becomes good.

Examples of the hydroxyl group-containing polymerizable unsaturated monomer (b) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and 3
-C2-C8 hydroxyalkyl (meth) acrylate of acrylic acid or methacrylic acid such as -hydroxypropyl (meth) acrylate and hydroxybutyl (meth) acrylate, N-methylol acrylamide, etc., and these may be used alone or in combination. The above can be used in combination. By using this monomer, a hydroxyl group is introduced into the acrylic resin (I), and a crosslinking functional group for reacting with a crosslinking agent (II) described later can be introduced.

Examples of the carboxyl group-containing polymerizable unsaturated monomer (c) include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid and itaconic acid. By using this monomer, a carboxyl group is introduced into the acrylic resin (I), and the resin (I) can have water-solubilizing ability and water-dispersing ability by neutralization. These can be used alone or in combination of two or more.

Examples of the other polymerizable unsaturated monomer (d) include methyl (meth) acrylate, ethyl (meth) acrylate, n-, i-, t-butyl (meth) acrylate and 2-ethylhexyl (meth). ) Acrylic acid such as acrylate and cyclohexyl (meth) acrylate, or aliphatic or alicyclic alkyl ester having 1 to 24 carbon atoms of methacrylic acid, vinyl aromatic monomer such as styrene, α-methylstyrene and vinyltoluene, (Meta)
Examples thereof include acrylamide and N-methylol acrylamide butyl ether, and these can be used alone or in combination of two or more kinds.

Further, an alkoxysilyl group-containing polymerizable unsaturated monomer can be exemplified, but in the present invention, from the viewpoint of storage stability of the acrylic resin (I) itself, it is not possible to use it as a copolymerization component. Not desirable.

The acrylic resin (I) is usually obtained by radical polymerization of the polymerizable unsaturated monomers (a) to (d) in a solvent with a radical polymerization initiator. In this polymerization, the copolymerization amount of each of (a) to (d) is about 0 for the compound (a) having two or more polymerizable unsaturated groups in one molecule.
5 to 10% by weight, preferably 1 to 5% by weight, hydroxyl group-containing polymerizable unsaturated monomer (b) is 5 to 30% by weight, preferably 10 to 20% by weight, carboxyl group-containing polymerizable unsaturated monomer 1 to 20% by weight of the body (c), preferably 2 to 10% by weight, and 40 to 9% of the other polymerizable unsaturated monomer (d).
A suitable range is 3.5% by weight, preferably 65 to 87% by weight. In particular, when the copolymerization amount of the compound (a) having two or more polymerizable unsaturated groups in one molecule is less than 0.5% by weight, a co-dispersion product of the acrylic resin (I) and the crosslinking agent (II) described later is obtained. On the other hand, the effect of improving the stability is insufficient. On the other hand, when it exceeds 10% by weight, the production stability tends to be deteriorated such as gelation during the production of the acrylic resin (I).

Examples of the radical polymerization initiator include organic azo compounds, peroxide compounds, sulfides, sulfines, diazo compounds and nitroso compounds. In the present invention, since the compound (a) having two or more polymerizable unsaturated groups in one molecule is copolymerized as a copolymerization component, it is used to stably produce the acrylic resin (I). The amount of the radical polymerization initiator is 0.5 to 10% by weight, preferably 0.5 to 10% by weight, based on the total amount of the polymerizable unsaturated monomers used in the production of the acrylic resin (I), depending on the type and amount of the compound (a). It is preferably used within the range of 1 to 5% by weight.

As the solvent used in radical polymerization,
It is desirable to use a solvent that dissolves the resulting copolymer and is miscible with water so that gelation does not occur during the copolymer reaction. As such a solvent, for example, a cellosolve solvent, a carbitol solvent, a glyme solvent, a cellosolve acetate solvent, an alcohol solvent, or the like can be used.

The acrylic resin (I) produced as described above has a weight average molecular weight of 5,000 to 150,000.
A range of 0, preferably 20,000 to 100,000 is suitable. When the weight average molecular weight is less than 5,000,
The storage stability of the paint may become insufficient, and in the case of producing a matte paint, there may be problems such as the need to add a large amount of the emulsion polymer (III) described later, while 150,000 If it exceeds, the finish of the electrodeposition coating film finally obtained tends to deteriorate.

The acid value of the acrylic resin (I) is 1
5 to 150 mg KOH / g, preferably 20 to 70 mg
A KOH / g and a hydroxyl value of 5 to 150 mgKOH / g, preferably 30 to 100 mgKOH / g are suitable. If the acid value is less than 15 mgKOH / g, the water dispersibility of the resin (I) and a mixture of the resin and a crosslinking agent (II) described later in water is insufficient, while 150 mgKO
When it exceeds H / g, the water resistance when formed into a coating film is insufficient, which is not preferable. If the hydroxyl value is less than 5 mgKOH / g, the curability will be poor, so the coating film hardness will be insufficient, while if it exceeds 150 mgKOH / g, hydroxyl groups that will not react with the crosslinking agent (II) described below will remain in the coating film. Therefore, the water resistance is insufficient, which is not preferable.

Crosslinking Agent (II) As the crosslinking agent (II) in the present invention, a crosslinking coating film is obtained by reacting with the hydroxyl group contained in the acrylic resin (I) and the emulsion polymer (III) described later, Melamine resin and / or blocked isocyanate can be preferably used.
The cross-linking agent (II) is compatible with the acrylic resin (I) with the aid of an organic solvent common to the acrylic resin (I), but in the absence of a solvent, one that is not completely compatible is preferable from the viewpoint of controlling the matting degree. .

The above-mentioned "not completely compatible" can be defined as follows, for example.

40 parts of acrylic resin (I) and crosslinking agent (II)
A compounded mixture of 60/60 weight ratio is mixed with 1.0 equivalent of an amine compound with respect to the carboxyl groups of the acrylic resin (I) and then dispersed in water to obtain an aqueous dispersion having a solid content of about 20% by weight. This is coated on a transparent glass plate so as to have a dry film thickness of 10 μm, the solvent is volatilized at room temperature to 100 ° C., and then dried at 150 to 200 ° C. for about 5 to 10 minutes. When turbidity is visually observed in this state, it can be said that the crosslinking agent (II) is not completely compatible with the acrylic resin (I).

Further quantitatively speaking, in the above coating film, the light transmittance at a wavelength of 4000 angstrom is measured by using a spectrophotometric system, and the transmittance is 95% or less, particularly in the range of 50 to 90%. In this case, it can be said that the crosslinking agent (II) is not completely compatible with the acrylic resin (I).

As the melamine resin, for example, one modified with one or more alcohols such as methanol, ethanol, propanol, butanol, octyl alcohol and 2-ethylhexyl alcohol can be used. Preferably C3 or more, especially C4-18
Those modified with the alcohol are preferred. It is preferable that the melamine resin contains an average of about 2.0 or more, particularly about 2.0 to 5.0, ether groups modified with a C3 or more alcohol per triazine ring nucleus.

Examples of the isocyanate used as the blocked isocyanate include aliphatic or alicyclic polyisocyanate compounds such as isophorone diisocyanate and hexamethylene diisocyanate, lactones such as ε-caprolactone, propanol, butanol, pentanol and benzyl alcohol. It is possible to use those blocked with the above alcohols or oximes such as methyl ethyl ketoxime and methyl isobutyl ketoxime.

Emulsion Polymer (III) In the present invention, the emulsion polymer (III) is blended in order to adjust the finished appearance of the electrodeposition coating film, particularly the matteness, depending on the object to be coated and the purpose. And an emulsion polymer produced by emulsion-polymerizing a polymerizable unsaturated monomer mixture in the presence of water and an emulsifier.

In particular, as the emulsion polymer (III), it is preferable to copolymerize an alkoxysilyl group-containing polymerizable unsaturated monomer (e) with the alkoxyl group-containing polymerizable unsaturated monomer (e). ) Are, for example, divinylmethoxysilane, divinyldi-β-methoxyethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris-β-methoxyethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltrisilane. Examples thereof include ethoxysilane, and these may be used alone or in combination of two or more kinds.

The alkoxysilyl group-containing polymerizable unsaturated monomer (e) is contained in an amount of 5 to 40% by weight based on all polymerizable unsaturated monomers used in the production of the emulsion polymer (III).
It is suitable to include it in a ratio of. If it is less than 5% by weight, the matte effect is insufficient, while if it exceeds 40% by weight,
Polymerization stability during synthesis tends to decrease.

Further, by cross-linking the inside of the emulsion polymer (III), the stability of the emulsion polymer (III) particles is improved and the matting effect of the finally obtained electrodeposition coating film is obtained. For the purpose of further improving, the compound (f) having two or more polymerizable unsaturated groups in one molecule is added to the emulsion polymer (II
It is desirable to copolymerize 1 to 20% by weight, preferably 2 to 10% by weight, based on all the polymerizable unsaturated monomers used in the production of I). If it is less than 1% by weight, the effect of improving the stability of particles and the matting effect are insufficient, and if it exceeds 20% by weight, the polymerization stability at the time of synthesis tends to decrease.

The compound (f) having two or more polymerizable unsaturated groups in one molecule is a compound (a) having two or more polymerizable unsaturated groups in one molecule used in the acrylic resin (I). The same as the above) can be used.

Copolymerization components other than the above-mentioned alkoxysilyl group-containing unsaturated monomer (e) and compound (f) having two or more polymerizable unsaturated groups are listed in the above description of the acrylic resin (I). The polymerizable unsaturated monomer (b),
It can be appropriately selected and used from the examples of (c) and (d).

In particular, as the polymerizable unsaturated monomer, the emulsion polymer (III) is provided with crosslinkability to obtain the emulsion polymer (III).
In order to improve the stability of the particles, it is desirable to copolymerize the aforementioned hydroxyl group-containing unsaturated monomer (b). The copolymerization amount is preferably such that the hydroxyl value of the emulsion polymer (III) is 2 to 40 mgKOH / g based on the resin solid content.

As the emulsifier used in the production of the above emulsion polymer (III), a sodium salt or ammonium salt of a sulfuric acid ester group, a sulfonic acid group, a phosphoric acid group or the like, or a reactive emulsifier having these can be used. Among them, a reactive emulsifier having a polymerizable unsaturated group and an ammonium salt in one molecule can be preferably used because of its good matting effect and excellent coating film performance. The amount of the emulsifier is the emulsion polymer (III)
0.5 for all polymerizable unsaturated monomers used in the production of
It is preferably ˜5% by weight. As usable polymerization initiators, potassium persulfate, sodium persulfate, ammonium persulfate, azobiscyanovaleric acid, 2,
Organic azo compounds such as 2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide],
Examples thereof include organic peroxides such as benzoyl peroxide and di-t-butyl hydroperoxide. It is also possible to use a redox initiator in combination therewith. These polymerizable initiators are preferably used within the range of 0.1 to 1.0% by weight based on the total polymerizable unsaturated monomers used for the production of the emulsion polymer (III). .

Anion-type electrodeposition coating composition The anion-type electrodeposition coating composition of the present invention contains the above-mentioned acrylic resin (I) and cross-linking agent (II), and contains the emulsion polymer (III). Depending on the presence or absence, the finish is glossy,
Can be applied to both matte. In producing a coating for gloss in the present invention, for example, a method of neutralizing the acrylic resin (I), mixing the crosslinking agent (II) after water dispersion, and mixing the acrylic resin (I) and the crosslinking agent (II). Examples of the method include neutralization and water dispersion after mixing.

Examples of the neutralizing agent include aliphatic amines such as monoethylamine, diethylamine and triethylamine, cyclic amines such as pyridine and piperidine, monoethanolamine, diethanolamine, triethanolamine and mono (2-hydroxypropyl). Examples include amines, di (2-hydroxypropyl) amine, tri (2-hydroxypropyl) amine, alkanolamines such as dimethylaminoethanol and diethylaminoethanol, and ammonia, which may be used alone or in combination of two or more. Is also good.

The mixing ratio of the acrylic resin (I) and the crosslinking agent (II) is such that (I) is 3 with respect to the total of these resin solids.
0-80% by weight, preferably 40-70% by weight, (II)
Is 20 to 70% by weight, preferably 30 to 60% by weight.

On the other hand, the acrylic resin (I) obtained above
Of the emulsion polymer (II
A matting paint can be easily obtained by simply adding and mixing I). At this time, the acrylic resin (I) and the crosslinking agent (I
The blending ratio of I) and the emulsion polymer (III) is such that (I) is 30 to 70% by weight, preferably 40 to 60% by weight, and (II) is 20 to 60% by weight based on the total of these resin solids. %, Preferably 30 to 50% by weight, (III) 5 to 30% by weight,
A range of 5 to 20% by weight is preferable. (I)
When the content is less than 30% by weight, the coating film performance such as curability and weather resistance is insufficient, and when it exceeds 70% by weight, the gloss tends not to disappear even when the emulsion polymer (III) is added. is there. (I
If I) is less than 20% by weight, the coating properties such as curability and weather resistance will be insufficient, and if it exceeds 60% by weight, the storage stability of the coating will tend to be insufficient. If (III) is less than 5% by weight, the matting effect is insufficient, and if it exceeds 30% by weight, the finished skin tends to deteriorate.

Further, the composition of the present invention contains a curing / dissociation catalyst, a pigment, a filler, an aggregate, a pigment dispersant, a wetting agent, a defoaming agent, a plasticizer, an organic solvent, an antiseptic agent, an antifungal agent, and a pH. Regulator,
Corrosion preventive agents and the like can be appropriately selected and combined according to each purpose and can be blended.

The anion type electrodeposition coating composition of the present invention comprises aluminum, aluminum alloy, alumite, steel; plated steel sheet plated with zinc, tin, chromium, aluminum, etc .;
Alternatively, it can be applied to a metal material such as a steel plate which has been subjected to chemical conversion treatment with chromic acid or phosphoric acid or cathodic electrolytic treatment. In particular, it is desirable to apply to the field of aluminum building materials using colored or uncolored anodized aluminum materials.

As a coating method, for example, the composition of the present invention is used as an anion type electrodeposition coating bath (for example, solid content of about 5 to 20% by weight, preferably about 6 to 12% by weight), and the aluminum material in the bath. After soaking, the dry film thickness is about 5-30μ
Anion electrodeposition coating so that it becomes, then wash with water (tap water, permeated water, etc.) as necessary, and then bake (eg,
It can be carried out at about 160 to 200 ° C. for about 20 to 40 minutes).

[0039]

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples. In the examples, "part" and "%"
Indicates "part by weight" and "% by weight" unless otherwise specified. Further, the present invention is not limited to this embodiment.

Production of Acrylic Resin (I) Production Example 1 Isopropyl alcohol 1 in a reaction vessel equipped with a thermometer, a thermostat, a stirrer, a reflux condenser and a dropping device.
00 parts, n-butyl alcohol 150 parts, and butyl cellosolve 100 parts were charged, and a monomer mixture having the following composition was added dropwise to the mixture kept at 85 ° C. over 4 hours, and then 5 parts of azobisdimethylvaleronitrile was added to the reaction vessel. , 8
The mixture was kept at 5 ° C for 3 hours to obtain a light brown transparent acrylic resin solution (A-1) having a solid content of 59%. The obtained acrylic resin (A-1) has a weight average molecular weight of about 60,000 and an acid value of 46 mgKO.
It was H / g and the hydroxyl value was 67 mgKOH / g. Monomer mixture composition Styrene 50 parts Methyl methacrylate 190 parts n-Butyl acrylate 100 parts Ethyl acrylate 50 parts 2-Hydroxyethyl acrylate 70 parts Acrylic acid 30 parts Triallyl isocyanurate 10 parts Azobisdimethylvaleronitrile 4 parts.

Production Examples 2 to 6 Acrylic resin solutions (A-2) to (A-6) were obtained in the same manner as in Production Example 1 except that the composition of the monomer mixture dropped in Production Example 1 was as shown in Table 1 below. .

[0042]

[Table 1]

(Note 1) "KBM-503": manufactured by Shin-Etsu Chemical Co., Ltd., trade name, γ-methacryloxypropyltrimethoxysilane.

Production of Emulsion Polymer Production Example 7 298 parts of deionized water was charged into a reaction vessel equipped with a thermometer, a thermostat, a stirrer, a reflux condenser, and a dropping device, and the temperature was raised to 90 ° C. An aqueous solution of an initiator prepared by dissolving 0.15 part of "VA086" (Note 2) in 9.85 parts of deionized water was added thereto and stirred for 15 minutes. In a separate container, "SE-10N" (Note 3) 2 parts Deionized water 60 parts Styrene 33 parts n-Butyl acrylate 34 parts 1, 6 Hexanediol diacrylate 4 parts "KBM-503" (Note 1) 25 parts 2 -Hydroxyethyl acrylate 4 parts were mixed and stirred to prepare a monomer emulsion,
It was added dropwise to the reaction vessel over time. At the same time as the start of the dropping of the above-mentioned monomer emulsion, an initiator aqueous solution (“VA086” (Note 2), an aqueous solution prepared by dissolving 0.55 part in deionized water; 29.45 parts) was subjected to all the steps including the aging step described later. It dripped over 5 hours until completion. After the monomer emulsion was added dropwise, the mixture was aged for 1 hour to obtain a milky white emulsion polymer (B-1).
Got The solid content of the obtained emulsion polymer (B-1) is 20.
%, And the average particle diameter was 127 nm. (Note 2) "VA-086": Wako Pure Chemical Industries, Ltd., trade name,
Nonionic water-soluble polymerization initiator 2,2′-azobis [2
-Methyl-N- (2-hydroxyethyl) propionamide] (Note 3) "SE-10N": Asahi Denka Co., Ltd., trade name, ammonium sulfate-based reactive emulsifier.

Preparation of anion electrodeposition coating composition Example 1 Acrylic resin solution (A-1) 10 obtained in Production Example 1 in a container
2 parts, 40 parts of "Nikalac MX-430" (Note 4), and 0. 0 relative to the carboxyl group of the acrylic resin (A-1).
4 equivalents of triethylamine was blended, mixed and dispersed, and deionized water was gradually added dropwise with stirring to a resin solid content of 10% by weight to obtain a uniform emulsion. Triethylamine was added with further stirring to adjust the pH to 8.2.
The anionic electrodeposition coating composition for gloss (T-1) was obtained.

Example 2 Acrylic resin solution (A-1) 77 obtained in Production Example 1 in a container
Part, 40 parts of "Nikarac MX-430" (Note 4), and 0.4 with respect to the carboxyl group of the acrylic resin (A-1).
Equivalent amount of triethylamine was blended, mixed and dispersed, and while stirring, deionized water was gradually added dropwise so that the resin solid content was 10% by weight to obtain a uniform emulsion. 75 parts of the emulsion polymer (B-1) obtained in Production Example 7 was added thereto, and the pH was adjusted with triethylamine and deionized water while stirring.
The solid content was adjusted to 8.2 and the solid content was 10% by weight to obtain a matting anionic electrodeposition coating composition (T-2). (Note 4) "Nikarac MX-430": manufactured by Sanwa Chemical Co., Ltd., trade name, about 3 methyl groups per 1 melamine nucleus,
About 3 butyl groups and about 57% melamine resin with 100% solids.

Examples 3 to 6 and Comparative Examples 1 to 2 In Example 2, except that the compounding composition is shown in Table 2 below,
In the same manner as in Example 2, matting anion electrodeposition coating compositions (T-3) to (T-8) were obtained. The values in Table 2 are based on solid content.

Anion electrodeposition coated aluminum material (anodic oxide aluminum material having a film thickness of 10 μm) was used as an electrodeposition bath for each coating composition, and electrodeposition coating was performed in the electrodeposition bath, followed by washing with water and at 30 ° C. at 30 ° C. It was baked for a minute to give a test coated plate. The dry film thickness was 10 microns.

Evaluation Test Each coating composition obtained in Examples 1 to 6 and Comparative Examples 1 and 2 was evaluated according to the following criteria. The results are shown in Table 2. 60 ° Gloss Measured using a variable angle gloss meter UGV-50 (trade name, manufactured by Suga Test Materials Co., Ltd.). Appearance Each test coated plate was visually evaluated. Good: no abnormalities, bad: gloss unevenness, cissing, lumps, and dents occurred Adhesion Adhesiveness According to JIS H8602 4.7, 100 cross-cuts were made on the test coated plate surface using a single-edged razor blade at 1 mm intervals. The adhesive tape was adhered on the top and was peeled off instantly. Good: 100 remaining pieces, Bad: 1 to 99 remaining pieces
Individual pencil hardness According to JIS H8602 4.8, apply the pencil lead at an angle of about 45 ° to the test coated plate surface, press it firmly against the test coated plate surface so that the core does not break, and move forward at a uniform speed. Moved 10 mm. This operation was repeated 5 times by changing the test place, and the hardness symbol of the pencil when the coating film was not broken 4 or more times was defined as the pencil hardness.

Storability test (1) Storability of paints Each anionic electrodeposition coating composition (T-1) to (T-6) was p-typed.
After adjusting to H10 with triethylamine, 1
The sample was left to stand in a 00cc measuring cylinder at room temperature for 1 week, and the degree of sedimentation was visually evaluated. ○: No sedimentation, ○ △: A slight amount of sedimentation is observed, △: 0.
Sedimentation of 5 to 2 cc is observed, x: Sedimentation of 2 cc or more (2) Storage property of paint without addition of emulsion polymer In each of the anionic electrodeposition coating compositions (T-2) to (T-6), emulsion polymer Before adding (B-1), the pH was adjusted to 10 with triethylamine, and 100 c
It was allowed to stand in a measuring cylinder at room temperature for 1 week, and the degree of sedimentation was visually evaluated. ○: No sedimentation, ○ △: A slight amount of sedimentation is observed, △: 0.
Sedimentation of 5-2 cc is observed, x: Sedimentation of 2 cc or more (3) Storability of acrylic resin alone In a container of 250 cc, each acrylic resin solution (A-1) to (A-1) obtained in Production Examples 1 to 6 -6) was added and stored at 30 ° C. for 1 month, and then visually evaluated. ○: No change, ×: Gelation

[0051]

[Table 2]

(Note 5) "Death module BL-317
5 ”: Sumitomo Bayer Co., Ltd., trade name, oxime-blocked product of hexamethylene diisocyanate, solid content 100
%.

[0053]

EFFECTS OF THE INVENTION The anion-type electrodeposition coating composition of the present invention has excellent storage stability especially when the acrylic resin as the base resin is used alone. It is possible to form a coating film having excellent coating properties such as curability and adhesion to the substrate. further,
This has the advantage that a matte coating film having a desired glossiness can be easily obtained from a glossy coating film having a glossy feeling depending on the presence or absence, the amount, etc. of the addition of the emulsion polymer, and the degree of freedom in design is widened. .

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4J038 CC021 CC071 CC081 CG001                       CG141 CG171 CH031 CH041                       CH071 CH081 DA162 DG302                       GA01 GA03 GA06 GA15 KA03                       MA08 MA10 MA13 NA01 NA26                       PA04 PB05 PC02

Claims (4)

[Claims] 1. A compound (a) having two or more polymerizable unsaturated groups in one molecule, a hydroxyl group-containing polymerizable unsaturated monomer (b), and a carboxyl group-containing polymerizable unsaturated monomer (c). And an acrylic resin (I) obtained by copolymerizing another polymerizable unsaturated monomer (d), and a crosslinking agent (II)
An anionic electrocoating composition containing a melamine resin and / or a blocked isocyanate as the composition. 2. The acrylic resin (I) contains 0.5 to 1 of the compound (a) having two or more polymerizable unsaturated groups in one molecule.
0% by weight, 5 to 5 of the hydroxyl group-containing polymerizable unsaturated monomer (b)
Obtained by copolymerizing 30% by weight, 1 to 20% by weight of the carboxyl group-containing polymerizable unsaturated monomer (c), and 40 to 93.5% by weight of other polymerizable unsaturated monomer (d). The anionic electrocoating composition according to claim 1, which is 3. The anionic electrodeposition coating composition according to claim 1, wherein the acrylic resin (I) has a weight average molecular weight of 5,000 to 150,000. 4. The anionic electrocoating composition according to any one of claims 1 to 3, which further comprises an emulsion polymer (III).