JP2002038084A - Anionic electrodeposition coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anionic electrodeposition coating composition excellent in curing properties and weather resistance. SOLUTION: The anionic electrodeposition coating composition comprises an acrylic copolymer (A) having an acid value of 20-200 mgKOH/g and a hydroxy value of 20-200 mgKOH/g, an amino resin curing agent (B), a blocked polyisocyanate compound curing agent (C), an ultraviolet absorbing agent component (D) and a photostabilizer component (E).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel anionic electrodeposition coating composition.

[0002]

2. Description of the Related Art Conventionally, as an anionic coating composition, a melamine curing type electrodeposition coating composition comprising a melamine resin curing agent blended with a polyol resin or a block polyisocyanate curing agent blending with a polyol resin. The isocyanate-curable electrodeposition coating composition is generally used.

However, the melamine-curable electrodeposition coating composition usually requires a baking temperature of 180 ° C. or higher, so that a load is easily applied to the substrate to be coated, and the type of the substrate to be coated is limited. There is a problem that the fuel cost is high, so that the product cost is high.In addition, since it is a melamine crosslink, there is also a problem that the coating film performance such as weather resistance, processability, and top coat adhesion is inferior. . In addition, it is possible to lower the temperature by adding an acid catalyst such as paratoluenesulfonic acid to the melamine-curable electrodeposition coating composition, but the coating film is discolored yellow and the weather resistance and processability are further reduced. There is a problem of doing.

On the other hand, the block polyisocyanate-curable electrodeposition coating composition, like the melamine-curable electrodeposition coating composition, usually requires a baking temperature of 180 ° C. or more, so that the substrate to be coated is loaded. However, there is a problem that the type of the substrate to be coated is easily restricted, and the cost of the product is increased because the blocked polyisocyanate curing agent is expensive. An organotin catalyst was added to the blocked polyisocyanate-curable electrodeposition coating composition as a dissociation catalyst for the blocked polyisocyanate curing agent, and the mixture was heated at 160 ° C.
Although it is possible to lower the temperature to a certain extent, there is a problem that the cost is further increased.

It is also conceivable to use a melamine resin curing agent and a blocked polyisocyanate curing agent in combination with the polyol resin. However, in this case, the acid catalyst for curing the melamine used at the time of lowering the temperature is the same as that of the blocked polyisocyanate curing agent. There is a problem that the temperature cannot be lowered because the dissociation of the blocking agent is delayed, and the reaction of the melamine curing agent by the organotin catalyst for curing the blocked polyisocyanate is delayed.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, the secondary carbamate group of the blocked polyisocyanate curing agent is bonded to N of the amino resin. Active hydrogen group, a methylol group or a paint obtained by combining a methylol derivative in which a methylol group is substituted with a lower alkyl group and an acid-based catalyst,
The present inventors have found that a coating film having excellent curability can be formed at a relatively low temperature of about ° C, and have completed the present invention.

That is, the present invention provides an acid value of 20 to 200 mgK.
OH / g, acrylic copolymer (A) having a hydroxyl value of 20 to 200 mg KOH / g, amino resin curing agent (B), blocked polyisocyanate compound curing agent (C), ultraviolet absorber (D) component and light stabilizer The present invention relates to an anionic electrodeposition coating composition comprising the component (E).

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. Acrylic copolymer (A) used in the present invention
Is a resin containing an active hydrogen group such as a hydroxyl group and a carboxyl group in the resin.

The acrylic copolymer (A) is obtained by subjecting a hydroxyl group-containing vinyl monomer, an ethylenically unsaturated carboxylic acid and, if necessary, other unsaturated monomers to a radical copolymerization reaction. .

The following are examples of these monomer components. (1) Hydroxyl-containing vinyl monomers: for example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, (poly) ethylene glycol mono (meth) Acrylate, (poly) propylene glycol mono (meth) acrylate, hydroxybutyl vinyl ether,
(Meth) allyl alcohol and the above-mentioned hydroxyl-containing vinyl monomers and β-propiolactone, dimethylpropiolactone, butyrolactone, γ-valerolactone, γ-caprolactone, γ-caprylolactone, γ-
As a product name such as a reaction product with a lactone compound such as laurilolactone, ε-caprolactone, δ-caprolactone, etc., as a trade name, Praxel FM1 (manufactured by Daicel Chemical Industries, trade name,
Caprolactone-modified (meth) acrylic acid hydroxyesters), Praxel FM2 (same as left), Praxel FM
3 (same as left), Plaxel FA-1 (same left), Plaxel FA2 (same left), Plaxel FA3 (same left) and the like.

(2) Ethylenically unsaturated carboxylic acids: for example, (meth) acrylic acid, maleic acid, Plaxel F
M1A (hereinafter, manufactured by Daicel Chemical Industries, caprolactone-modified carboxyl group-containing (meth) acrylic monomer, trade name), Praxel FM4A, Praxel FM10A and the like.

(3) Other unsaturated monomers: for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate Octyl (meth) acrylate, lauryl (meth) acrylate, C1-18 alkyl or cycloalkyl esters of (meth) acrylic acid such as cyclohexyl (meth) acrylate, aromatic vinyl monomers such as styrene, Meta)
(Meth) acrylamides such as acrylamide, N-butoxymethyl (meth) acrylamide, N-methylol (meth) acrylamide and derivatives thereof, and (meth)
Acrylonitrile compounds, etc., alkoxysilyl groups such as γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, vinyltrimethoxysilane Containing vinyl monomers.

As the above monomer component, vinyl monomers containing an alkoxysilyl group are used as a matting agent.

In the proportion of these monomers, the above-mentioned hydroxyl-containing monomers have a copolymer having a hydroxyl value of about 2
The amount of the hydroxyl group-containing monomer may be about 3 to 40% by weight, preferably about 5 to 5% by weight in terms of the total amount of the above monomers.
It is in the range of 30% by weight.

The above ethylenically unsaturated carboxylic acid may be blended so that the acid value of the copolymer falls within the range of about 20 to 200 mg KOH / g, but is based on the total amount of the above monomers. And the ethylenically unsaturated carboxylic acid ranges from about 3 to 30% by weight, preferably about 4 to 20% by weight.

As the other unsaturated monomers, it is preferable to use C1-C18 alkyl or cycloalkyl esters of (meth) acrylic acid and aromatic vinyl monomers such as styrene. The amount of the monomers is about 37 to 95 based on the total amount of the monomers.
%, Preferably in the range of about 60-91% by weight.

As a method of causing a radical copolymerization reaction,
Conventionally known solution polymerization methods can be used.

Amino resin curing agent (B) used in the present invention
A conventionally known amino resin can be used. Examples of the amino resin include a methylolated amino resin obtained by reacting an amino component such as melamine, urea, benzoguanamine, acetogranamine, sterogtanamine, spiroguanamine, and dicyandiamide with an aldehyde. Aldehydes include formaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde and the like. Further, those obtained by etherifying the methylolated amino resin with an appropriate alcohol can also be used. Examples of the alcohol used for the etherification include methyl alcohol, ethyl alcohol, n-propyl alcohol, i-propyl alcohol, and n-butyl alcohol. , I-butyl alcohol, 2-ethylbutanol, 2-ethylhexanol and the like.

As the blocked polyisocyanate compound curing agent (C) used in the present invention, those obtained by blocking the isocyanate group of a conventionally known polyisocyanate compound with a blocking agent can be used.

Examples of the polyisocyanate compound include aliphatic diisocyanates such as hexamethylene diisocyanate or trimethylhexamethylene diisocyanate; cycloaliphatic diisocyanates such as hydrogenated xylylene diisocyanate or isophorone diisocyanate; tolylene diisocyanate or 4,4 ' Organic diisocyanates themselves such as aromatic diisocyanates such as diphenylmethane diisocyanate, or adducts of each of these organic diisocyanates with polyhydric alcohols, low molecular weight polyester resins or water, or cyclization of each organic diisocyanate as described above Polymers, and isocyanate / biuret compounds, etc., are examples of typical commercial products. D-750, -800, DN-95
0, -970 or 15-455] [Dai Nippon Ink and Chemicals, products], "Desmodur L, N, H
L, IL or N3390] [manufactured by Bayer AG, West Germany], "Takenate D-102, -202, -110"
N or 123N "[Takeda Pharmaceutical Co., Ltd.]," Coronate L, HL, EH or 203 "[Nippon Polyurethane Industry Co., Ltd.] or" Duranate 24A-90C "
X "[Asahi Kasei Kogyo Co., Ltd.] and the like.

Of these, aliphatic diisocyanates and cycloaliphatic diisocyanates are preferred.

Examples of the blocking agent include phenol-based, lactam-based, active methylene-based, alcohol-based, mercaptan-based, acid amide-based, imide-based, amine-based, imidazole-based, urea-based, and carbamate esters. A blocking agent such as a system, an imine system, or a sulfite system may be used.

In the present invention, the carbamate group of the blocked polyisocyanate curing agent (C) is combined with the functional group of the amino resin curing agent (B) such as a methylol group or an alkylated methylol group (lower alkyl derivative of methylol). An acid catalyst (F) that promotes the condensation reaction can be used. The catalyst is preferably a catalyst which promotes the reaction between the carbamate group and the amino resin curing agent before the blocking agent is separated from the isocyanate at the time of baking of the coating film. Specifically, for example, sulfuric acid, phosphoric acid, paratoluenesulfonic acid and derivatives thereof, trichloroacetic acid, trifluoromethanesulfonic acid, monobutyl phosphate, dibutyl phosphate, boron trifluoride and the like can be mentioned.

In the present invention, the blending ratio of the acrylic copolymer (A), the amino resin curing agent (B), the blocked polyisocyanate compound curing agent (C) and the acid catalyst (F) is 100% of the resin (A). Curing agent (B) based on parts by weight
15 to 100 parts by weight, preferably 15 to 50 parts by weight, curing agent (C) 1 to 100 parts by weight, preferably 5 to 50 parts by weight, catalyst (F) 0 to 10 parts by weight, preferably 0.001 parts by weight
To 1 part by weight, further 0.1 to 1 part by weight.

In the ultraviolet absorber (D) component and the light stabilizer (E) component used in the present invention, either one or both of these components may be simply mixed into the electrodeposition coating material, or may be mixed. Although the polymer (A) may be chemically bonded, it is preferable that both components are chemically bonded to the copolymer (A) from the viewpoint of maintaining the performance (weather resistance and the like) of these components.

Examples of the ultraviolet absorbent (D) used in the mixed system include salicylic acid derivatives such as phenyl salicylate, p-octylphenyl salicylate and 4-t-butylphenyl salicylate; Dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4-methoxy-5
-Sulfobenzophenone trihydrate, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone,
-Hydroxy-4-octoxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, sodium 2,2'-dihydroxy-4,4'-dimethoxy-5-sulfobenzophenone, 2,2 ', 4,4'- Tetrahydroxybenzophenone, 4-dodecyloxy-2
-Hydroxybenzophenone, 5-chloro-2-hydroxybenzophenone, resorcinol monobenzoe-
2,4-dibenzoylresorcinol, 4,6-dibenzoylresorcinol, hydroxydodecylbenzophenone, 2,2'-dihydroxy-4 (3-methacryloxy-2-hydroxypropoxy) benzophenone, etc. Benzophenone type; 2- (2′-hydroxy-5)
Examples thereof include benzotriazole-based compounds such as' -methylphenyl) benzotriazole, and other (oxalic acid anilide, cyanoacrylate, etc.) compounds.

The light stabilizer (E) used in the mixed system is a hindered amine derivative, specifically, bis-amine.
(2,2 ', 6,6'-tetramethyl-4-piperidinyl) sebate, 4-benzoyloxy-2,2',
6,6′-tetramethylpiperidine and the like can be mentioned, and one or more of these can be appropriately selected and used.

As a method of chemically bonding the ultraviolet absorber (D) component or the light stabilizer (E) component to the copolymer (A), for example, the copolymer (A) is used to form the copolymer. The radical polymerizable monomer component can be introduced by using a polymerizable unsaturated monomer (d) having an ultraviolet absorber component or a polymerizable unsaturated monomer (e) having a light stabilizer component.

In addition to the above, it can be introduced by reacting the ultraviolet absorbent (f) having an alcoholic hydroxyl group with the hydroxyl group of the copolymer (A) via the polyisocyanate.

Examples of the polymerizable unsaturated monomer (d) include 2- (2′-hydroxy-5′-methacryloxyethylphenyl) -2H-benzotriazole and 2-hydroxy-4- (3-methacryloxy-2). -Hydroxypropoxy) benzophenone, 2-hydroxy-4
-(3-acryloxy-2-hydroxypropoxy) benzophenone, 2,2'-dihydroxy-4- (3
-Methacryloxy-2-hydroxypropoxy) benzophenone, 2,2'-hydroxy-4- (3-acryloxy-2-hydroxypropoxy) benzophenone, 2 (N-methacryloyl) aminobenzophenone, and the like. Also, as the product name, for example, RUV
A-93 (manufactured by Otsuka Chemical Co., Ltd.).

Examples of the polymerizable unsaturated monomer (e) include those represented by the following general formula.

[0032]

Embedded image

(Wherein, in the general formula, R 1 is a hydrogen atom or a cyano group, R 2 and R 3 are each independently a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, and R 4 is a hydrogen atom or a 1 to 18 carbon atoms. X represents an imino group or an oxygen atom.) Specifically, for example, 4- (meth) acryloyloxy-
1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloylamino-2,2,6,6- Tetramethylpiperidine, 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4- (meth)
Acryloylamino-1,2,2,6,6-pentamethylpiperidine, 4-cyano-4- (meth) acryloylamino-
2,2,6,6-tetramethylpiperidine and the like can be mentioned. As a product name, for example, FA-711MM,
FA-712HM (all manufactured by Hitachi Chemical Co., Ltd.) and the like.

As the ultraviolet absorber (f), for example,
2,2′-methylenebis [6- (2H-benzotriazol-2-yl) -4- (hydroxymethyl) phenol], 2,2′-methylenebis [6- (2H-benzotriazol-2-yl) -4 -(2-hydroxyethyl) phenol], 2,2′-methylenebis [6- (5
-Chloro-2H-benzotriazol-2-yl) -4
-(2-hydroxyethyl) phenol], 2,2'-
Methylenebis [6- (2H-benzotriazole-2-
Yl) -4- (3-hydroxypropyl) phenol], 2,2'-methylenebis [6- (5-chloro-2
H-benzotriazol-2-yl) -4- (3-hydroxypropyl) phenol], 2,2′-methylenebis [6- (5-bromo-2H-benzotriazole-2)
-Yl) -4- (3-hydroxypropyl) phenol], 2,2'-methylenebis [6- (2H-benzotriazol-2-yl) -4- (2-hydroxypropyl) phenol], 2,2 ' -Methylenebis [6- (5
-Chloro-2H-benzotriazol-2-yl) -4
-(2-hydroxypropyl) phenol], 2,2 '
-Methylenebis [6- (5-bromo-2H-benzotriazol-2-yl) -4- (2-hydroxypropyl) phenol], 2,2'-methylenebis [6- (2
H-benzotriazol-2-yl) -4- (4-hydroxybutyl) phenol], 2,2'-methylenebis [6- (5-chloro-2H-benzotriazole-2-
Yl) -4- (4-hydroxybutyl) phenol].

The mixing ratio of the component (D) is from (A) to
It is preferably 0.01 to 10% by weight, particularly 0.1 to 5% by weight in terms of the total weight of (E). If the amount used is less than 0.01% by weight, the weather resistance is poor, while if it exceeds 10% by weight, gloss, curability, chemical resistance and workability are reduced.

The mixing ratio of the component (E) is from (A) to
It is preferably 0.01 to 10% by weight, particularly 0.1 to 5% by weight in terms of the total weight of (E). If the amount used is less than 0.01% by weight, the weather resistance is poor, while if it exceeds 10% by weight, gloss, curability, chemical resistance and workability are reduced.

The electrodeposition coating composition of the present invention is obtained by dissolving or dispersing an organic solvent resin composition dissolved or dispersed in an organic solvent or a resin obtained by neutralizing a carboxyl group in a resin with a basic compound in water. It can be obtained by:

The organic solvent is not particularly limited as long as it can dissolve or disperse the base resin, and a conventionally known organic solvent can be used.

Specifically, xylene and toluene are used as hydrocarbons, propanol and butanol are used as alcohols, and cellosolve is used as ether is used as ethers.
Examples of ketones such as methyl cellosolve, butyl cellosolve, methyl carbitol, 2-methoxyethanol, diethylene glycol, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and triethylene glycol monomethyl ether include acetone, methyl ethyl ketone, 2-pentanone, and 2-hexanone. , Methyl isobutyl ketone, isophorone, cyclohexanone and the like, such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate,
Cellosolve acetate, carbitol acetate and the like can be mentioned.

Examples of the basic compound include hydroxides of alkali metals or alkaline earth metals such as sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide and barium hydroxide; ammonia; dimethylethanol Tertiary monoamines such as amine, trimethylamine, triethylamine, triisopropylamine, methyldiethanolamine and dimethylaminoethanol can be mentioned.

The paint of the present invention may optionally contain pigments, dyes, fluidity modifiers and the like.

The paint of the present invention can be used as a glossy, semi-gloss, matte paint or the like, and a coating film can be formed by the following non-rinse or rinse electrodeposition coating method.

The paint of the present invention is preferably applied as an electrodeposition paint in the field of aluminum building materials using a colored or uncolored anodized aluminum material.

As a method of forming a coating film using the electrodeposition paint, the aqueous paint of the present invention is used as an electrodeposition paint bath, and after dipping the aluminum material in this bath, the dry film thickness is about 5%. ~ 3
Anion electrodeposition coating is performed so as to have a thickness of 0 micron, without water washing (non-rinsing) or with water washing (rinsing), followed by setting at room temperature, followed by baking (for example,
At about 120 to 200 ° C. for about 20 to 40 minutes) to form a coating film.

[0045]

The paint of the present invention has a secondary carbamate group (-NHC) bonded to a blocked polyisocyanate curing agent.
OO-, Chemical 2

[0046]

Embedded image

In the formula, R represents the same or different and represents an alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group.)) And a methylol group or a methylol group directly bonded to a nitrogen atom of an amino resin. Since it is a paint containing a functional group having a methylol derivative substituted with an alkyl group (methyl group, ethyl group, propyl group, butyl group, etc.) and an acid-based catalyst as essential components, a relatively low temperature of about 120 ° C. By baking, the curing reaction between the carbamate group of the blocked polyisocyanate curing agent and the above-described functional group of the amino resin is performed in a temperature range lower than the temperature at which the blocking agent dissociates in the presence of the acid-based catalyst. Excellent, and further baking volatilizes the blocking agent and regenerates the free isocyanate group. Processability, coating film excellent in chemical resistance and the like is presumed to have been formed. Further, since the above-mentioned crosslinking reaction does not proceed at a temperature of about 50 ° C. or less, the storage stability of the coating material is excellent, and the flowability of the coating material is improved, so that the coating film is smooth and the like.

Also, by blending the UV absorber (D) component and the light stabilizer (E) component, a coating film having excellent discoloration and weather resistance due to the blocking agent can be formed without lowering the curability. Therefore, it is particularly effective as a colored electrodeposition coating composition.

Further, when used as an electrodeposition paint such as matte or semi-gloss, an alkoxysilyl group-containing vinyl monomer is used as a matting agent. The radical copolymerizability of the monomer containing the absorbent (D) component and the monomer containing the light stabilizer (E) component is excellent, so that the workability of electrodeposition coating, finished appearance, chemical resistance, etc. of the coating film are reduced. The weather resistance was able to be improved without making it.

[0050]

EXAMPLES The present invention will be described in detail with reference to examples. The invention is not limited to the embodiments provided.

Production Example of Acrylic Copolymer (a) 70 g of isopropyl alcohol was charged into a reaction vessel and kept at 80 ° C., and 10 g of styrene, 30 g of methyl methacrylate, 9 g of n-butyl acrylate, 30 g of ethyl acrylate, 12 g of 2-hydroxyethyl acrylate, 7 g of acrylic acid, 2- (2'-hydroxy-5'-
1 g of methacryloxyethylphenyl) -2H-benzotriazole, 4-methacryloyloxy-1,2,2,6,6-
A mixture of 1 g of pentamethylpiperidine and 2 g of azobisdimethylvaleronitrile was added dropwise over 3 hours, and then 1 g of azobisdimethylvaleronitrile was added.
The reaction was carried out at a temperature of 1 ° C. for 1 hour to obtain a copolymer (a) varnish. The copolymer has a weight average molecular weight of about 20,000 and an acid value of 5
5 mgKOH / g and a hydroxyl value of 58 mgKOH / g. This copolymer (a) is used for a glossy electrodeposition paint.

Production Example of Acrylic Copolymer (b) 70 g of isopropyl alcohol was charged into a reaction vessel and kept at 80 ° C., and 10 g of styrene, 28 g of methyl methacrylate, 8 g of n-butyl acrylate, 29 g of ethyl acrylate, 12 g of 2-hydroxyethyl acrylate, 7 g of acrylic acid, 2- (2'-hydroxy-5'-
(Methacryloxyethylphenyl) -2H-benzotriazole 3 g, 4-methacryloyloxy-1,2,2,6,6-
A mixture of 3 g of pentamethylpiperidine and 2 g of azobisdimethylvaleronitrile was added dropwise over 3 hours, and then 1 g of azobisdimethylvaleronitrile was added.
The reaction was carried out at a temperature of 1 ° C. for 1 hour to obtain a varnish of copolymer (b). The copolymer has a weight average molecular weight of about 20,000 and an acid value of 5
5 mgKOH / g and a hydroxyl value of 58 mgKOH / g. This copolymer (b) is used for a glossy electrodeposition coating.

Production Example of Acrylic Copolymer (c) In the production example of the acrylic copolymer (b), 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidine was used in place of 4-methacryloyloxy. It was produced in the same manner as in the acrylic copolymer (b) except that methacryloyloxy-2,2,6,6-tetramethylpiperidine was used. The copolymer had a weight average molecular weight of about 20,000, an acid value of 55 mg KOH / g, and a hydroxyl value of 5
It was 8 mgKOH / g. This copolymer (c) is used for glossy electrodeposition paints.

Production Example of Acrylic Copolymer (d) 70 g of isopropyl alcohol was charged into a reaction vessel and kept at 80 ° C., into which 10 g of styrene, 31 g of methyl methacrylate, 10 g of n-butyl acrylate, 30 g of ethyl acrylate, 2-hydroxyethyl acrylate
A mixture of 12 g of acrylic acid, 7 g of acrylic acid, and 2 g of azobisdimethylvaleronitrile was added dropwise over 3 hours, and then 1 g of azobisdimethylvaleronitrile was added.
And the reaction was carried out for 1 hour to obtain a copolymer (d) varnish. The copolymer has a weight average molecular weight of about 20,000 and an acid value of 55.
mgKOH / g and hydroxyl value were 58 mgKOH / g. This copolymer (d) is used for a glossy electrodeposition paint.

Production Example of Acrylic Copolymer (e) 70 g of isopropyl alcohol was charged into a reaction vessel and kept at 80 ° C., and 10 g of styrene, 23 g of methyl methacrylate, γ-methacryloxypropyltrimethoxy were added. 7 g of silane, 9 g of n-butyl acrylate, 30 g of ethyl acrylate, 12 g of 2-hydroxyethyl acrylate, 7 g of acrylic acid, 2- (2'-hydroxy-5'-
1 g of methacryloxyethylphenyl) -2H-benzotriazole, 4-methacryloyloxy-1,2,2,6,6-
A mixture of 1 g of pentamethylpiperidine and 2 g of azobisdimethylvaleronitrile was added dropwise over 3 hours, and then 1 g of azobisdimethylvaleronitrile was added.
The reaction was carried out at a temperature of 1 ° C. for 1 hour to obtain a copolymer (e) varnish. The copolymer had a weight average molecular weight of about 25,000, an acid value of 55 mg KOH / g, and a hydroxyl value of 58 mg KOH / g. This copolymer (e) is used for a matte electrodeposition paint.

Production Example of Acrylic Copolymer (f) 70 g of isopropyl alcohol was charged into a reaction vessel and kept at 80 ° C., and 10 g of styrene, 21 g of methyl methacrylate, γ-methacryloxypropyl trimethoxy were added. 7 g of silane, 8 g of n-butyl acrylate, 29 g of ethyl acrylate, 12 g of 2-hydroxyethyl acrylate, 7 g of acrylic acid, 2- (2'-hydroxy-5'-
(Methacryloxyethylphenyl) -2H-benzotriazole 3 g, 4-methacryloyloxy-1,2,2,6,6-
A mixture of 3 g of pentamethylpiperidine and 2 g of azobisdimethylvaleronitrile was added dropwise over 3 hours, and then 1 g of azobisdimethylvaleronitrile was added.
The reaction was carried out at a temperature of 1 ° C. for 1 hour to obtain a varnish of copolymer (f). The copolymer had a weight average molecular weight of about 25,000, an acid value of 55 mg KOH / g, and a hydroxyl value of 58 mg KOH / g. This copolymer (f) is used for a matte electrodeposition paint.

Production Example of Acrylic Copolymer (g) In the production example of the acrylic copolymer (f), 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidine was used in place of 4-methacryloyloxy. It was produced in the same manner as for the acrylic copolymer (f) except that methacryloyloxy-2,2,6,6-tetramethylpiperidine was used. The copolymer had a weight average molecular weight of about 25,000, an acid value of 55 mg KOH / g, and a hydroxyl value of 58 mg KOH / g. This copolymer (g) is used for a matte electrodeposition paint.

Production Example of Acrylic Copolymer (h) 70 g of isopropyl alcohol was charged into a reaction vessel and kept at 80 ° C., and 10 g of styrene, 24 g of methyl methacrylate, γ-methacryloxypropyltrimethoxy were added. 7 g of silane, 10 g of n-butyl acrylate, 30 g of ethyl acrylate, 2-hydroxyethyl acrylate
A mixture of 12 g of acrylic acid, 7 g of acrylic acid, and 2 g of azobisdimethylvaleronitrile was added dropwise over 3 hours, and then 1 g of azobisdimethylvaleronitrile was added.
And reacted for 1 hour to obtain a varnish of copolymer (h). The copolymer had a weight average molecular weight of about 25,000, an acid value of 55 mg KOH / g, and a hydroxyl value of 58 mg KOH / g. This copolymer (h) is used for a matte electrodeposition paint.

Example 1 After 7 kg (solid content) of the above copolymer (a) was mixed with 0.4 equivalent of triethylamine with respect to the carboxyl group of the copolymer (a), the mixture was dispersed and then dispersed. , Cymel 300 (Mitsui Cytec Co., Ltd., trade name, methoxymelamine resin), 2 kg, duranate 24
After mixing and dispersing 1 kg of A-90CX (trade name, block polyisocyanate compound, manufactured by Asahi Kasei Kogyo Co., Ltd.) and 50 g of p-toluenesulfonic acid, deionized water was gradually added dropwise with stirring, and the pH was further increased to 8.0. Then, triethylamine was added to obtain a glossy electrodeposition paint having a solid content of 8% by weight in Example 1.

Example 2 A glossy electrodeposition paint having a solid content of 8% by weight in Example 2 was prepared in the same manner as in Example 1 except that the copolymer (a) was changed to the copolymer (b). Was manufactured.

Example 3 A glossy electrodeposition paint having a solid content of 8% by weight in Example 3 was prepared in the same manner as in Example 1 except that the copolymer (a) was replaced with the copolymer (c). Was manufactured.

Comparative Example 1 0.4 kg of triethylamine with respect to the carboxyl group of the copolymer (d) was mixed with 7 kg (solid content) of the copolymer (d), mixed and dispersed, and then mixed. , Cymel 300 (Mitsui Cytec Co., Ltd., trade name, methoxymelamine resin), 2 kg, duranate 24
A-90CX (manufactured by Asahi Kasei Corporation, trade name, blocked polyisocyanate compound) 1 kg, Tinuvin 328
(Ciba Geigy Co., Ltd., trade name, UV absorber) 7
0 g, Tinuvin 292 (manufactured by Ciba-Geigy Corporation, trade name, light stabilizer) 70 g, p-toluenesulfonic acid 50 g
After mixing and dispersing, deionized water was gradually added dropwise with stirring, and triethylamine was further added so that the pH became 8.0, whereby a glossy electrodeposition paint having a solid content of 8% by weight in Comparative Example 1 was obtained. Manufactured.

Comparative Example 2 A glossy electrodeposition paint having a solid content of 8% by weight in Comparative Example 2 was prepared in the same manner as in Example 1 except that the copolymer (a) was replaced with the copolymer (d). Was manufactured.

Example 4 After mixing 7 kg (solid content) of the above copolymer (e) with 0.4 equivalent of triethylamine based on the carboxyl group of the copolymer (e), the mixture was dispersed and then dispersed. 2 kg of Niraclac MX-430 (trade name, manufactured by Sanwa Chemical Co., Ltd., about 3 methyl groups and about 3 butyl groups per melamine nucleus, the amount of which is about 57%), duranate 24A-90CX ( After mixing and dispersing 1 kg of a block polyisocyanate compound (trade name, manufactured by Asahi Kasei Kogyo Co., Ltd.) and 50 g of p-toluenesulfonic acid, deionized water is gradually added dropwise with stirring, and the pH is further increased to 8.0.
To obtain a matte electrodeposition paint having a solid content of 10% by weight.

Example 5 The procedure of Example 4 was repeated, except that the copolymer (e) was replaced with the copolymer (f).
A weight percent matte electrodeposition coating was prepared.

Example 6 The procedure of Example 4 was repeated, except that the copolymer (e) was replaced by the copolymer (g).
A weight percent matte electrodeposition coating was prepared.

Comparative Example 3 After mixing 7 kg (solid content) of the above copolymer (h) with 0.4 equivalent of triethylamine based on the carboxyl group of the copolymer (h), the mixture was dispersed and then dispersed. 2 kg of Niraclac MX-430 (trade name, manufactured by Sanwa Chemical Co., Ltd., about 3 methyl groups and about 3 butyl groups per melamine nucleus, the amount of which is about 57%), duranate 24A-90CX ( 1 kg of Asahi Kasei Kogyo Co., Ltd., trade name, block polyisocyanate compound), 70 g of Tinuvin 328 (trade name, ultraviolet absorber), 70 g of Tinuvin 292 (trade name, light stabilizer) of Ciba Geigy Corporation, After mixing and dispersing 50 g of p-toluenesulfonic acid, deionized water is gradually added dropwise while stirring, and then the pH is adjusted to 8.0 with a trie. Addition of tylamine and solid content of Comparative Example 3 10% by weight
To produce a matte electrodeposition paint.

Comparative Example 4 The procedure of Example 4 was repeated, except that the copolymer (e) was replaced with the copolymer (h).
A weight percent matte electrodeposition coating was prepared.

Coating method (rinse): The electrodeposition paints obtained in the above Examples and Comparative Examples were used as an electrodeposition bath, and an object to be coated (anodized aluminum material having a film thickness of about 10 μm (size: Is 1m long x 0.1m wide x 0.5mm thick)
Is suspended vertically, and anion electrodeposition coating is performed so that the dry film thickness becomes about 10 microns. Then, after the coated material is pulled up from the bath, the coated material is pulled up from the bath tub and washed with water at 20 ° C., and Next, baking was performed at 170 ° C. for 30 minutes to form coating films of Examples and Comparative Examples.

The test method is as follows. Specular reflectivity: JIS K-5400 60 degree specular reflectivity was measured. Smoothness: The surface of the coating film (yuzu skin, unevenness, etc.) was visually evaluated. Is good, ○ is almost good, Δ is slightly bad, and × is bad. Storage stability: paint in test tube (height 20cm, capacity 20c)
c), and allowed to stand at 20 ° C. for 7 days to confirm the presence or absence of a precipitate. ◎ is good when the precipitate is 0.5 mm or less, は is almost good when the precipitate is 0.6 to 1 mm or less, △ is 1 to
3mm: Somewhat poor, x: Poor precipitate with 4mm or more.

Adhesiveness: Goban eye tape method JISK54
This was done based on 00. ◎: no peeling at all, ○: slight peeling of the cut part is recognized but no problem in practical use, △: 1 to 50 squares peeled off,
× indicates that 51 or more cells were peeled off.

Alkali resistance: After immersion in a 1% aqueous sodium hydroxide solution at 20 ° C. for 160 hours, the presence or absence of abnormality in the coated surface was examined. ◎ indicates no abnormality, は indicates slight swelling but no practical problem, Δ indicates swelling is inferior, and X indicates much swelling and is remarkably inferior.

Acid resistance: 160 ° C. in 5% sulfuric acid aqueous solution at 20 ° C.
After immersion for a period of time, the painted surface was examined for abnormalities. ◎ indicates no abnormality, は indicates slight swelling but no practical problem, Δ indicates swelling is inferior, and X indicates much swelling and is remarkably inferior.

Weather resistance: Evaluated by the gloss retention (%) after 2000 hours and 4000 hours of irradiation with a sunshine weatherometer.

Table 1 shows the results of the appearance and performance of the glossy coating film, and Table 2 shows the results of the matte coating film. Table-1

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[Table 1]

Table 2

[0078]

[Table 2]

Claims (5)

[Claims] 1. An acrylic copolymer (A) having an acid value of 20 to 200 mg KOH / g, a hydroxyl value of 20 to 200 mg KOH / g, an amino resin curing agent (B), a blocked polyisocyanate compound curing agent (C), and ultraviolet absorption An anionic electrodeposition coating composition comprising a component (D) and a light stabilizer (E). 2. The electrodeposition coating composition according to claim 1, further comprising an acid catalyst (F).
3. The electrodeposition coating composition according to item 1. 3. The component (D) and the component (E), wherein one or both of these components are chemically bonded to the copolymer (A). 3. The electrodeposition coating composition according to item 2. 4. The electrodeposition coating composition according to claim 1, wherein the component (E) is a hindered amine light stabilizer. 5. The electrodeposition coating composition according to claim 1, wherein a color pigment is blended in the electrodeposition coating composition.