JP2000080332A - Resin composition for flatting anion electrodeposition coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve coating stability, flatting appearance, weatherability and gloss stability of flatting anion electrodeposition coating by a resin composition comprising an acrylic resin containing a carboxyl group, a specific organoalkoxysilane compound and an aluminum chelate compound. SOLUTION: In producing an acrylic resin, a polymerizable unsaturated carboxylic acid, a hydroxyl group-containing unsaturated monomer according to needs, an alkoxysilane group-containing unsaturated monomer or an epoxy group-containing unsaturated monomer are copolymerized to obtain an acrylic resin having a carboxyl group and a hydroxyl group or an epoxy group at a side chain or a termination of the copolymer. The acrylic resin has a hydroxyl value of 20-150 mgKOH/g, preferably 30-100 mgKOH/g and number average molecular weight of 2,000-70,000, preferably 4,000-50,000. A resin composition is obtained by compounding 100 pts.wt. of the acrylic resin, and 0.05-100 pts.wt. of an organoalkoxysilane compound having a glycidyl group and a hydrolyzable alkoxy silane group and 0.01-10 pts.wt. of an aluminum chelate compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a matte anion electrodeposition paint used for aluminum building materials and the like. More specifically, the present invention uses a matte anion electrodeposition coating resin composition which is excellent in paint stability and can form a coating film having good matte appearance and weather resistance and uses the paint resin composition. The present invention relates to a paint obtained by the above method.

[0002]

2. Description of the Related Art Heretofore, as a method for obtaining a matte coating film by electrodeposition coating, a method of containing an inorganic pigment such as silica fine powder (JP-A-56-75596), a fine powder of polyethylene or polypropylene, etc. (JP-A-60-135466), a method of post-treating an electrodeposited coating with an acidic treatment solution (JP-A-52-137444), and the like. However, in these methods, the persistence of the matting effect and the gloss are not constant, and uneven gloss occurs.In the post-treatment method, the number of steps is increased, and the uneven gloss occurs when pulling up from the processing solution or washing with water. In addition, there were drawbacks such as side effects in terms of coating film performance.

As a method for matting an electrodeposition paint which overcomes the above-mentioned disadvantages, a method of introducing a compound having a hydrolyzable alkoxysilane group having a double bond such as 3-methacryloyloxypropyltrimethoxysilane by copolymerization is used. (Japanese Patent Publication No. 62-24519), a method of reacting a carboxylic acid in a polymer molecule with an epoxysilane compound such as, for example, 3-glycidoxypropyltrimethoxysilane (JP-A-2-269780). An acrylic resin mixed with a curing agent such as an amino resin and dispersed in water is disclosed.

[0004] In the matting coating by this matting method, since the acrylic resin contains a hydrolyzable alkoxysilane group, silanol is generated and crosslinks are formed by a condensation reaction. Since the coating film does not melt and flow even during baking due to this cross-linking, it is widely used in the technical field to maintain an uneven structure at the time of coating and to form a good matte coating film.

[0005] However, since the formation of a cross-link using a hydrolyzable alkoxysilane group depends on the dispersion state, it is difficult to control the degree of cross-linking. And the problem that gloss unevenness is likely to occur. In the electrodeposition coating, there has been a demand for development of a paint which does not have such a problem, has high stability of the paint, and has no gloss variation and gloss unevenness.

[0006] A matting method using an aluminum chelate compound (JP-A-58-45270) has been proposed. However, in these paints or methods, the viscosity increases due to the progress of the crosslinking reaction in the paint and the storage stability. There was a problem that was bad. Further, the coating film using this paint has a problem that yellowing occurs and weather resistance is weak.

In order to further solve the above problem, a technique in which an alkoxysilane group and an aluminum chelate compound are used in combination has been proposed (JP-A-10-7949). However, an alkoxysilane group is copolymerized with an acrylic resin. Therefore, the storage stability of the resin is poor, and there is a possibility that the properties of the paint may vary, and there are many problems in production.

[0008]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and provides a matte anion type electrodeposition coating resin composition excellent in paint stability, gloss stability, and finished appearance, and the paint. The present invention provides a matte anion-type electrodeposition coating composition obtained by using a resin composition for an electrode. Further, the matte anion type electrodeposition coating resin according to the present invention is excellent in various properties (adhesion, appearance, weather resistance, chemical resistance, solvent resistance, etc.) required for the coating resin. Function can be fully exhibited.

[0009]

That is, the present invention provides an organoalkoxysilane compound (B) having a glycidyl group and a hydrolyzable alkoxysilane group per 100 parts by weight of an acrylic resin (A) having a carboxyl group. .
A matte anion electrodeposition coating resin composition, comprising 0.5 to 100 parts by weight and 0.01 to 10 parts by weight of an aluminum chelate compound (C).

The matte anion electrodeposition coating resin composition of the present invention further comprises an acrylic resin (A) 10
A preferred embodiment includes mixing 1 to 200 parts by weight of an epoxy resin having an epoxy equivalent of 10 to 500 with respect to 0 parts by weight.

Hereinafter, the present invention will be described in detail.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The acrylic resin (A) having a carboxyl group in a molecule according to the present invention is used for producing an acrylic resin, when acrylic acid, methacrylic acid, itaconic acid, maleic acid, vinyl acetic acid, fumaric acid, Polymerizable unsaturated carboxylic acids such as crotonic acid, acid phosphooxyethyl acrylate, acid phosphofooxyethyl methacrylate, acid phosphophooxypropyl methacrylate, acid phosphooxypolyoxyethylene glycol monoacrylate, acid phosphooxypolyoxyethylene glycol monomethacrylate Polymerizable unsaturated organic phosphoric acid such as acid phosphooxypolyoxypropylene monoacrylate, acid phosphooxypolyoxypropylene monomethacrylate, vinyl sulfonic acid, 2-acrylamide 2-methylpropane sulfonic acid, p- polymerizable unsaturated acid homopolymers such as polymerizable unsaturated organic sulfonic acids such as styrene sulfonic acid can be prepared by copolymerizing. These may be used alone or as a mixture of two or more types, but a polymerizable unsaturated carboxylic acid is preferred.

The polymerizable unsaturated acid monomer has an acid value of the acrylic resin (A) of preferably 20 to 150 mg KO.
H / g, more preferably 30-100 mgKOH / g
It is used in such a range. It is preferably at least 20 mgKOH / g for improving water dilutability and matting property, and is preferably within 150 mgKOH / g for improving water resistance and weather resistance.

The number average molecular weight of the acrylic resin (A) measured by GPC in terms of standard polystyrene is 20
00 to 70000 is preferred. Number average molecular weight 2000
If it is above, sufficient coating film durability can be obtained, and 70
When the molecular weight is 000 or less, a water dispersion type having good stability is easily obtained, the viscosity is appropriate, and the handling is good. In particular, the number average molecular weight is 4000 to 50,000 in terms of matting properties and stability.
It is preferred that

The acrylic resin (A) can be obtained by known methods such as solution polymerization, non-aqueous dispersion polymerization, bulk polymerization, emulsion polymerization and suspension polymerization of the above-mentioned monomers and other copolymerizable monomers. However, it is particularly preferable to obtain it by a solution polymerization method. Solution polymerization is carried out in a suitable inert solvent using α, α
Organic azo polymerization initiators such as' -azobisisobutyronitrile and α, α'-azobisvaleronitrile; organic peroxides such as benzoyl peroxide and t-butylperoxy-2-ethylhexanoate; By carrying out the reaction at a reaction temperature of usually about 0 to about 180 ° C, preferably about 40 to about 170 ° C, for about 1 to about 20 hours, preferably about 4 to about 15 hours. Can be.

As a solvent to be used, it is desirable to use a solvent which dissolves the produced copolymer and is miscible with water so as not to gel during polymerization. Such solvents include alcohols, cellosolves, carbitols,
Solvents such as grime and cellosolve acetate can be used. Particularly, hydrophilic organic solvents such as isopropyl alcohol, n-butyl alcohol, ethyl cellosolve, and butyl cellosolve are preferable.

The other copolymerizable monomer is a component that mainly forms the skeleton of an acrylic resin, and alkyl esters such as acrylic acid and methacrylic acid, or ordinary vinyl monomers are preferably used. . Acrylic acid,
Examples of alkyl esters such as methacrylic acid include, for example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n
-Butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, t
-Butyl acrylate, t-butyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate, stearyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate dimethylaminoethyl methacrylate, methacryloxypropyl trimethoxysilane, methylol acrylamide , Methylol methacrylamide,
n-butoxymethylacrylamide, n-butoxymethylmethacrylamide, propoxymethylacrylamide, propoxymethylmethacrylamide and the like. Examples of the vinyl monomer include, but are not limited to, styrene, methylstyrene, vinyl toluene, vinyl acetate, acrylonitrile, acrylamide, methacrylamide, and the like.

The above copolymerizable monomer is preferably used as a constituent of the acrylic resin (A) in the range of 20 to 90% by weight, and these may be used alone or in combination of two or more. Can also be used. When the content is 20% by weight or more, the coating film has sufficient hardness and weather resistance. When the content is 90% by weight or less, appropriate fluidity is obtained.

It is also possible to produce a macromonomer having a polymerizable terminal group, alone or in combination of two or more kinds, by copolymerizing with the above components.

The macromonomer having a polymerizable terminal group is mainly used for the purpose of improving the performance of a coating film and the stability of an aqueous dispersion, and is a copolymer of a polymerizable monomer having a polymerizable terminal group. Coalescing is used. For example, methacryloyl group and dihydroxyl group are often used for the terminal group, and the segment part is a copolymer of polymerizable monomers such as methyl methacrylate, styrene, styrene and acrylonitrile, butyl acrylate, isobutyl methacrylate, hexamethyl acrylate, and dimethyl siloxane. But are not limited to these.

The preferred number average molecular weight of the macromonomer is from 2,000 to 40,000. When the number average molecular weight is 2,000 or more, a sufficient effect of adding the macromonomer is obtained, and when the number average molecular weight is 40,000 or less, the obtained resin has appropriate fluidity and is easy to handle. The macromonomer is 0.1% as a component of the acrylic resin (A).
It is preferably used in the range of 30 to 30% by weight, and these can be used alone or in combination of two or more.
When the content is 0.1% by weight or more, the effect of the macromonomer is sufficiently obtained, and when the content is 30% by weight or less, the cross-linking reaction between the acrylic resin and the amino resin is not inhibited.

The acrylic resin (A) can be produced, if necessary, by copolymerizing with an unsaturated monomer having an alkoxysilane group. Examples of the alkoxysilane group-containing unsaturated monomer include divinyldimethoxysilane, divinyldi-β-methoxyethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltributoxysilane, and vinyltripentoxy. Silane, vinyl tris-β-
Methoxyethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, trimethoxyallylsilane, triethoxyallylsilane, (meth) acryloylmethyltrimethoxysilane, (meth) acryloylethyltrimethoxysilane, An unsaturated dialkoxysilane compound or an unsaturated trialkoxysilane compound such as (meth) acryloyl propyltrimethoxysilane is exemplified. These alkoxysilane group-containing unsaturated monomers,
One type may be used alone, or two or more types may be used in combination.

The acrylic resin (A) preferably has a hydroxyl group as a functional group other than a carboxyl group on the side chain or at the terminal of the polymer. Thereby, the solvent resistance of the cured coating film is dramatically improved. In addition, adhesion, coating film appearance,
The coating film performance such as weather resistance is excellent.

Acrylic resin (A) having a hydroxyl group as a functional group other than a carboxyl group on the side chain or terminal of the polymer
Are used when producing an acrylic resin, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, acrylic acid 2
-Hydroxyethyl, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monoacrylate, polypropylene glycol monomethacrylate, polytetramethylene glycol monoacrylate,
Hydroxyl-containing unsaturated monomers such as adducts of polytetramethylene glycol monomethacrylate, acrylic acid or methacrylic acid having 2 to 8 hydroxyalkyl esters with lactones such as ε-caprolactone or γ-valerolactone It can be produced by copolymerizing the body. In addition, instead of a simple hydroxyl group, an unsaturated monomer having a methylol group such as cyclohexane dimethanol monoacrylate, cyclohexane dimethanol monoacrylate, N-methylol acrylamide, N-methylol methacrylamide is used as a hydroxyl group-containing unsaturated monomer. It can be produced by copolymerization. These monomers may be used alone or as a mixture of two or more.

These monomers have an acrylic resin (A) having a hydroxyl value of preferably 30 to 150 mgKOH / g,
More preferably, it is used in the range of 40 to 100 mgKOH / g. Hydroxyl value is 30mgKOH / g
If it is above, curability is sufficiently obtained, and 150 mg
If it is within KOH / g, the coating film is prevented from being embrittled and has good water resistance.

The acrylic resin (A) preferably has an epoxy group as a functional group other than a carboxyl group on the side chain or terminal of the polymer.

The acrylic resin (A) having an epoxy group as a functional group other than a carboxyl group on the side chain or at the terminal of the polymer can be used for producing an acrylic resin such as glycidyl acrylate, glycidyl methacrylate, methyl glycidyl acrylate, methyl glycidyl methacrylate, etc. It can be produced by copolymerizing an unsaturated monomer containing an epoxy group. Further, an alicyclic epoxy group-containing unsaturated monomer such as 3,4-epoxycyclohexanemethyl acrylate and 3,4-epoxycyclohexanemethyl methacrylate is more preferable in terms of storage stability. These monomers may be used alone or as a mixture of two or more.

It is preferable that these monomers are used in an amount of 2 to 50 parts by weight based on 100 parts by weight of the unsaturated monomer having a carboxyl group. If the amount is less than 2 parts by weight, sufficient curability may not be obtained, and if it exceeds 50 parts by weight, the storage stability of the composition tends to deteriorate.

The acrylic resin (A) may further comprise 2- (2'-hydroxy-5'-methacryloxyethylphenyl) -2H-, if necessary, for the purpose of improving and improving weather resistance.
Benzotriazole, 2- (2'-hydroxy-5'-
Acryloxyethylphenyl) -2H-benzotriazole and other copolymerizable ultraviolet absorbers and 1,2,2,6,6-
A copolymerizable HALS (light stabilizer) such as pentamethyl-4-piperidyl methacrylate may be copolymerized. These monomers may be used alone or in a mixture of two or more.

The organoalkoxysilane compound (B) having a glycidyl group and a hydrolyzable alkoxysilane group in one molecule includes γ-glycidoxypropyltrimethoxysilane and γ-glycidoxypropyltriethoxy in the present invention. Silane, γ-glycidoxypropyltriisopropoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyldimethoxysilane, and the like. These compounds can be used alone or It may be a mixture of two or more. Further, partial condensates of these compounds may be used.

Organoalkoxysilane compound (B)
Is 0.05 with respect to 100 parts by weight of the acrylic resin (A).
-100 parts by weight, whereby a paint having excellent properties such as curability, storage stability and weather resistance can be obtained. 0.05
If the amount is less than 100 parts by weight, the curability is reduced. If the amount is more than 100 parts by weight, only the surface of the coating is dried and hardened quickly, and the appearance of the coating film is deteriorated.

The aluminum chelate compound (C) of the present invention includes aluminum ethyl acetoacetate diisopropylate, aluminum tris (ethyl acetoacetate), alkyl acetoacetate aluminum diisopropylate, aluminum tris (acetyl acetate), aluminum bisethylacetate There are acetate monoacetylacetonate, aluminum monoacetylacetonate bis (alkylacetoacetate) and the like, and these may be used alone or as a mixture of two or more. The compound functions as a starter for curing the curable resin composition of the present invention.

It is well known that a corresponding chelating agent is added as a stabilizer so that it does not inadvertently perform its function during storage, and the present invention is suitably carried out. That is, in order to improve storage stability, acetylacetone,
It is preferable to add methyl acetoacetate, ethyl acetoacetate and the like.

The aluminum chelate compound (C) is used in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the acrylic resin (B).
Use parts by weight. If the amount is less than 0.01 part by weight, the curability of the coating material deteriorates, the crosslinking is delayed, and the solvent resistance and weather resistance of the coating film are reduced. If it exceeds 10 parts by weight, it will not be able to be sufficiently dissolved in the acrylic resin, and conversely, the curability will be deteriorated, and there will be bumps on the coating film, and the appearance of the coating film will deteriorate.

In the matte anion electrodeposition coating resin composition of the present invention, in addition to the acrylic resin (A), the organoalkoxysilane compound (B) and the aluminum chelate compound (C), the oxy equivalent is more preferable. 10 to 500 epoxy resins (D) can be blended. The mixing ratio of the epoxy resin (D) is preferably 1 to 2 with respect to 100 parts by weight of the acrylic resin (A).
00 parts by weight, more preferably 3 to 50 parts by weight.

If the proportion of the epoxy resin is less than 1 part by weight, the coating film tends to be hard and brittle, and if it exceeds 200 parts by weight, sufficient curability and corrosion resistance cannot be obtained.

Epoxy resin (D) used in the present invention
Is arbitrarily selected from many commercially available ones,
Can be used. That is, these include polyphenol type, polyglycidylamine type, alcohol type,
Ester type, alicyclic epoxy resins and the like (Reference: 13197, Chemical Products, Chemical Daily Inc. (19
1997), P923-P931). More preferred is an alicyclic epoxy resin, and a paint having a composition using such an epoxy resin has very good stability. Specifically, examples of the alicyclic epoxy resin include 3,4-epoxycyclohexylmethyl-3 ′, 4 ′ epoxycyclohexane carbonate, bis (3,4-epoxycyclohexylmethyl) adipate, and the like. These epoxy resins may be used alone or as a mixture of two or more.

The matte anion electrodeposition coating resin composition of the present invention comprises an acrylic resin (A) having a carboxyl group in a side chain, an organoalkoxysilane compound (B), an aluminum chelate compound (C), and further, Accordingly, if the epoxy resin (D) is uniformly mixed, the object can be achieved by any method.

Briefly, while stirring the acrylic resin (A), the aluminum chelate compound (C), the organoalkoxysilane compound (B) and, if necessary, the epoxy resin (D) are added, and the mixture is stirred until it becomes uniform. Continue to manufacture. Heating may be used if necessary during this manufacturing process, but sufficient manufacturing is possible at room temperature, and stability of the manufacturing (because the curing reaction proceeds during the manufacturing and no gel is formed), storage From the viewpoint of stability, it is preferable to manufacture at 20 to 50 ° C.

Furthermore, by adding a hydrophilic organic solvent containing water and stirring and mixing until the mixture becomes uniform, the curability at low temperatures can be further improved.

Another effective method is to produce the organoalkoxysilane compound (B) as described below, and then blend it with other raw materials to similarly improve the curability at low temperatures.

That is, a predetermined amount of the organoalkoxysilane compound (B) is measured in a container equipped with a stirrer, and while stirring, a hydrophilic organic solvent containing water is added to dilute the organoalkoxysilane compound (B). Is prepared in advance.

The term "hydrophilic organic solvent" as used herein refers to an organic solvent which is dissolved in water at 20 ° C. in a volume ratio of 10% or more, such as alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, and n-butyl alcohol; Examples include glycol ethers such as glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol butyl ether. These solvents may be used alone or as a mixture of two or more.

By incorporating a hydrophilic organic solvent, the curability and storage stability of the composition are improved, and the finish of a paint prepared using the matte anion electrodeposition coating resin composition of the present invention is improved. The appearance is improved. The hydrophilic organic solvent is preferably used in an amount of 100 parts by weight or less based on 100 parts by weight of the organoalkoxysilane compound (B) in order to prevent only the surface drying of the paint from being promoted.

Further, 100 parts by weight or less of water is added to the hydrophilic organic solvent based on 100 parts by weight of the hydrophilic organic solvent (preferably at 25 ° C. to improve the storage stability of the composition.
Is diluted with 6.8 or less ion-exchanged water), whereby the curability at low temperatures is further improved.

The matting anion electrodeposition coating resin composition of the present invention can be used as it is or as a surfactant for preparing a paint, that is, if necessary, for improving drying unevenness and water washability. , Matting aid and pigment for improving smoothness, wax and latex for improving smoothness and matting, curing catalyst for improving coating hardness, other colorants, plasticizers, acidic / basic Substances and the like can be appropriately added. Further, if necessary, other resins such as melamine resin, polyester resin, silicone resin, and acrylic resin, and polypropylene glycol, polyethylene glycol, and the like can be added as long as the effects of the present invention are not impaired.

The object to be applied to the matte electrodeposition coating method of the present invention is not particularly limited as long as it has conductivity, but when aluminum or an aluminum alloy is used as the object to be coated, the smoothness is low. And a uniform matte coating film having excellent hardness and the like can be obtained, and a matte coating film having both a soft appearance and a high hardness, in which dice marks and the like of an aluminum material are not conspicuous, can be obtained.

[0048]

The present invention will be described in more detail with reference to the following specific examples.

Production Example 1 70 parts by weight of isopropyl alcohol and 20 parts by weight of butyl cellosolve were charged into a reaction vessel and heated to the reflux temperature. 15 parts by weight of acrylic acid, 10 parts by weight of ethyl acrylate, 10 parts by weight of butyl acrylate, 5 parts by weight of n-butoxymethylacrylamide, 60 parts by weight of methyl methacrylate and 0.8 parts of azobisisobutyronitrile
A mixture consisting of parts by weight was added dropwise at reflux temperature for 3 hours.
One hour after the completion of dropping, 0.8 parts by weight of azobisisobutyronitrile and 1 part of isopropyl alcohol
0 parts by weight was added four times at intervals of 30 minutes, and after the addition was completed, the polymerization was further continued for 1 hour to obtain the acrylic resin of Production Example 1.

Production Example 2 70 parts by weight of isopropyl alcohol and 20 parts by weight of butyl cellosolve were charged into a reaction vessel and heated to the reflux temperature. 15 parts by weight of acrylic acid, 10 parts by weight of ethyl acrylate, 10 parts by weight of butyl acrylate, 5 parts by weight of n-butoxymethylacrylamide, 40 parts by weight of methyl methacrylate, 20 parts by weight of 2-hydroxyethyl methacrylate and azobisisobutyronitrile A mixture consisting of 0.8 parts by weight was added dropwise at reflux temperature for 3 hours. One hour after the completion of the dropwise addition, 0.8 parts by weight of azobisisobutyronitrile and 10 parts by weight of isopropyl alcohol were further added in four portions every 30 minutes, and polymerization was continued for another hour after the addition was completed. The acrylic resin of Production Example 2 was obtained.

Production Example 3 70 parts by weight of isopropyl alcohol and 20 parts by weight of butyl cellosolve were charged into a reaction vessel and heated to the reflux temperature. 15 parts by weight of acrylic acid, 10 parts by weight of ethyl acrylate, 10 parts by weight of butyl acrylate, 5 parts by weight of n-butoxymethylacrylamide, 35 parts by weight of methyl methacrylate, 20 parts by weight of 2-hydroxyethyl methacrylate, 5 parts by weight of glycidyl methacrylate And a mixture of 0.8 parts by weight of azobisisobutyronitrile were added dropwise at reflux temperature for 3 hours. One hour after the completion of the dropwise addition, 0.8 parts by weight of azobisisobutyronitrile and 10 parts by weight of isopropyl alcohol were further added in four portions every 30 minutes, and polymerization was continued for another hour after the addition was completed. The acrylic resin of Production Example 3 was obtained.

Production Example 4 70 parts by weight of isopropyl alcohol and 20 parts by weight of butyl cellosolve were charged into a reaction vessel and heated to the reflux temperature. 15 parts by weight of acrylic acid, 15 parts by weight of ethyl acrylate, 10 parts by weight of butyl acrylate, 5 parts by weight of n-butoxymethylacrylamide, 35 parts by weight of methyl methacrylate, 20 parts by weight of 2-hydroxyethyl methacrylate, 3,4-epoxycyclohexane A mixture consisting of 5 parts by weight of methyl methacrylate and 0.8 parts by weight of azobisisobutyronitrile was added dropwise at reflux temperature for 3 hours. One hour after the completion of the dropwise addition, 0.8 parts by weight of azobisisobutyronitrile and 10 parts by weight of isopropyl alcohol were further added in four portions every 30 minutes, and polymerization was continued for another hour after the addition was completed. The acrylic resin of Production Example 4 was obtained.

Example 1 100 parts by weight of the acrylic resin of Production Example 1 were charged, and 1 part by weight of aluminum chelate AW (aluminum chelate compound (aluminum tris (acetyl acetate)); a product of Kawaken Fine Chemicals Co., Ltd.) with stirring. And stirred until homogeneously dissolved. To this, 20 parts by weight of SH-6040 (organoalkoxysilane compound (γ-glycidoxypropyltrimethoxysilane); manufactured by Dow Corning Toray Silicone Co., Ltd.) was added, and the mixture was stirred and mixed until it became uniform. A resin composition for anion electrodeposition coating of Example 1 was obtained.

Example 2 A resin composition for anion electrodeposition coating of Example 2 was obtained in the same manner as in Example 1 except that the acrylic resin was changed to Production Example 2.

Example 3 A resin composition for anion electrodeposition coating of Example 3 was obtained in the same manner as in Example 1 except that the acrylic resin was changed to Production Example 3.

Example 4 A resin composition for anion electrodeposition coating of Example 4 was obtained in the same manner as in Example 1 except that the acrylic resin was changed to Production Example 4.

Example 5 100 parts by weight of the acrylic resin of Production Example 1 were charged, and while stirring, aluminum chelate DOL (aluminum chelate compound (aluminum monoacetylacetonate bis (alkyl acetoacetate)); Kawaken Fine Chemical Co., Ltd.
1 part by weight, SH-6040 (organoalkoxysilane compound (γ-glycidoxypropyltrimethoxysilane)); 20 parts by weight of Toray Dow Corning Silicone Co., Ltd.), ERL-4221 (fat) Cyclic epoxy resin (3,4-epoxycyclohexylmethyl-3 ′, 4 ′ epoxycyclohexane carbonate)); product of Union Carbide Nihon Co.)) 3
0 parts by weight was added, and the mixture was stirred and mixed until it became uniform, to obtain a resin composition for anion electrodeposition coating of Example 5.

Comparative Example 1 A resin composition for coating was obtained in the same manner as in Example 1 except that an acrylic resin was used as Production Example 1 and no organoalkoxysilane compound was added.

Comparative Example 2 A resin composition for anion electrodeposition coating of Comparative Example 2 was obtained in the same manner as in Example 1 except that the acrylic resin was used in Production Example 1 and no aluminum chelate compound was added.

The compositions obtained in the Examples and Comparative Examples and the melamine resin (Cymel 235; manufactured by Mitsui Cytec Co., Ltd.) were mixed by stirring at a ratio of 60/40 at 25 ° C. for 30 minutes. Triethylamine was added in an amount of 60% neutralization, and the mixture was further stirred at 25 ° C. for 10 minutes, and then gradually diluted with deionized water to prepare an electrodeposition paint having a resin solid content of 10%.

The electrodeposited paint was placed in an electrodeposition bath, and anodized and subjected to AC-colored 6063 s aluminum plate as an anode. Electrodeposition coating was performed. After completion of the electrodeposition, the electrodeposition was washed with water containing 2% by weight of isopropanol and 1% by weight of butyl cellosolve, and air-dried at room temperature for 10 minutes.
The composition was heated and cured at 80 ° C. for 30 minutes, and the obtained electrodeposition coating film was evaluated for performance.

The results are shown in Table 1. The evaluation method and evaluation criteria in the present invention are as follows. (1) Appearance of coating film: The surface of the electrodeposition coating film was visually observed, and the presence or absence of gloss unevenness was evaluated. (2) Gloss: The glossiness due to 60 ° specular reflection is determined by JISK5.
It was measured according to 4007.6. (3) Hardness: A pencil scratch test was performed according to JIS K5400 8.4. (4) Adhesion: A 1 × 10 × 10 × 10-mesh test (based on JIS K5400) was performed at 1 mm, and the adhesion to the aluminum substrate was indicated by the number of non-peeling / 100. (5) Alkali resistance A spot test (temperature: 23 ° C.) was performed for 24 hours using an aqueous 1% sodium hydroxide solution, and then the presence or absence of the above on the coating film surface was observed.

[0063]

[Table 1]

[0064]

The resin composition for a matte anion type electrodeposition coating composition of the present invention is formed into a coating composition by a usual coating preparation method, then electrodeposited and dried by heating to obtain a coating film appearance, adhesion, A coating film excellent in many coating performances such as weather resistance, chemical resistance, and solvent resistance can be obtained.

Claims (5)

[Claims] 1. An organoalkoxysilane compound (B) having a glycidyl group and a hydrolyzable alkoxysilane group (B) in an amount of 0.05 to 100 parts by weight, based on 100 parts by weight of an acrylic resin (A) having a carboxyl group, and an aluminum chelate. A matte anion electrodeposition coating resin composition comprising 0.01 to 10 parts by weight of a compound (C). 2. The matte anion electrodeposition coating resin composition according to claim 1, wherein the acrylic resin (A) has a hydroxyl group as a functional group other than a carboxyl group at a polymer side chain or terminal. 3. The matte anion electrodeposition coating resin composition according to claim 1, wherein the acrylic resin (A) has an epoxy group as a functional group other than a carboxyl group at a polymer side chain or terminal. object. 4. The matte anion electrodeposition coating resin composition according to claim 3, wherein the epoxy group is introduced by copolymerizing an unsaturated monomer containing an alicyclic epoxy group. 5. An epoxy resin (D) having an epoxy equivalent of 10 to 500 and 1 to 200 parts by weight are mixed with 100 parts by weight of the acrylic resin (A). The resin composition for matte anion electrodeposition coating according to any one of the above.