JPH0633004A - Resin composition for flat electrodeposition coating - Google Patents

Abstract

PURPOSE:To provide a resin composition for electrodeposition coating capable of forming a coating film excellent in physical properties. CONSTITUTION:This resin composition for flat coating is characterized by its film-forming components composed of (a) an alpha,beta-ethylenic unsaturated polycarboxylic acid resin containing 0.1 to 10.0wt.% vinyl silicone macromer and (b) an alkoxylated methylol melamine and its composition containing products obtained by heating an aqueous emulsion containing the components (a) and (b). This composition can form a coating film excellent in surface smoothness and water repellency and, therefore, remarkably improved in dew-fall resistance and scuff resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a matte electrodeposition coating resin composition for forming a matte coating on a conductive article such as an aluminum building material.

[0002]

2. Description of the Related Art Conventionally, as a method for forming a matte coating film,
Japanese Examined Patent Publication No. 60-19922 has been implemented for many years. When the above invention is outlined, the resin composition is (a)
Product obtained by heating an aqueous emulsion containing α, β-ethylenically unsaturated polycarboxylic acid resin and (b) alkoxylated methylol melamine as a coating film forming component and containing the components (a) and (b) It is a resin composition for matte coating characterized in that it is a composition containing, and a matte coating film can be formed by using any coating means such as brush coating, dipping, spraying, electrostatic, and electrodeposition coating. In particular, when the electrodeposition coating is applied, the lusterless phenomenon does not occur, and the gloss value of the obtained coating film is less than 10% by the measurement of 60 ° specular gloss, which is an extremely low gloss and fine texture. It has the effect of obtaining the appearance of a matte coating film.

When the resin composition of the invention is used as a paint for electrodeposition coating, the reason for forming a matte coating film has not yet been clarified, but the α, β-ethylenically unsaturated poly (ethylenically unsaturated poly) is contained in the resin composition. It is presumed that the mixing of the high molecular weight reaction product of the carboxylic acid resin and the alkoxylated methylolmelamine is involved in the formation of the matte coating film.

[0004]

However, in the above-mentioned invention, the properties that the physical properties of the coating film are required to be stricter, such as scratch resistance, are not always satisfactory. An object of the present invention is to solve the problems of the conventional electrodeposition coating composition and to provide a resin composition for electrodeposition coating composition having excellent characteristics.

[0005]

In order to achieve the above object, the inventors of the present invention have earnestly studied the conditions for improving the physical performance of a coating film such as scratch resistance, and as a result, the acrylic resin composition for electrodeposition coating has been obtained. By using a vinyl-based silicon macromer as an essential component of the copolymer, the physical performance of the coating film, that is, the surface slipperiness of the electrodeposition coating film and the water repellency are remarkably improved. The present invention has been completed based on the finding that the scratch resistance and the like are remarkably improved.

That is, the present invention provides a resin composition comprising (a)
0.1 to 10.0% by weight of vinyl-based silicon macromer
After the α, β-ethylenically unsaturated polycarboxylic acid resin containing and (b) alkoxylated methylol melamine are used as the film-forming components, the components (a) and (b) are partially neutralized with a hydrophilic base. A resin composition for matte electrodeposition coating is characterized in that it is a composition containing a product obtained by adding water, emulsifying and then heating.

[0007]

The structure and operation of the present invention will be described. The α, β-ethylenically unsaturated polycarboxylic acid resin used in the present invention is
(A) α, β-ethylenically unsaturated polycarboxylic acid 3 to 3
0% by weight, (b) 5 to 30% by weight of hydroxyalkyl-containing ester or amide or amide derivative of α, β-ethylenically unsaturated carboxylic acid, (c) alkyl ester of α, β-ethylenically unsaturated carboxylic acid 30 -80% by weight, (d) vinyl-based silicon macromer 0.1-10.
The acid value is obtained by reacting a monomer composition of 0% by weight, (e) 0 to 20% by weight of another copolymerizable monomer, and the total amount thereof is 100% by weight. 10
Those of ˜200 are preferable.

Suitable (a) α, β-ethylenically unsaturated carboxylic acids for the present invention include acrylic acid, α-chloroacrylic acid, methacrylic acid, itaconic acid, maleic anhydride, maleic acid, fumaric acid and croton. Acids, citraconic acid, mesaconic acid, etc., alone or in mixtures, or functional derivatives thereof having at least one carboxyl group, such as unsaturated polymerizable di- or poly-carboxylic acid partial esters or amides.

Next, (b) as hydroxyalkyl-containing ester or amide or amide derivative of α, β-ethylenically unsaturated carboxylic acid, 2-hydroxyethyl acrylate, 2-hydroxydiethyl methacrylate,
2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 4
-Hydroxybutyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, acrylamide, methacrylamide, methylol acrylamide, methylol methacrylamide,
Examples include alkoxymethylol acrylamide, diacetone acrylamide, and diacetone methacrylamide.

(C) Examples of the alkyl ester of α, β-ethylenically unsaturated carboxylic acid include methyl acrylate, methyl methacrylate, ethyl acrylate,
Ethyl methacrylate, n-propyl acrylate, n
-Propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, butyl acrylate, butyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate, stearyl methacrylate, hexyl acrylate, 2-ethylhexyl methacrylate, heptyl acrylate,
Similar esters can be used, such as heptylmethacrylate, having up to about 20 carbon atoms in the alkyl group.

And (d) the vinyl silicone macromer as an essential component constituting the α, β-ethylenically unsaturated polycarboxylic acid resin of the present invention is represented by Chemical Formula 1 (X-24-8200, X-, manufactured by Shin-Etsu Chemical Co., Ltd.). 24-8201) or Chemical formula 2 (X-248202 manufactured by Shin-Etsu Chemical Co., Ltd.).

[0012]

[Chemical 1]

[0013]

[Chemical 2]

When the vinyl-based silicon macromer is less than 0.1% by weight, the effect of surface slipperiness and water repellency is not obtained, and on the other hand, 1
If it exceeds 0.0% by weight, the coating film may repel,
It is not preferable because it causes defects such as deterioration of adhesion of the coating film.

(E) Other copolymerizable monomers include
Examples include styrene, α-alkylstyrene, α-chlorostyrene, vinyltoluene, acrylonitrile, vinyl acetate and the like. (F) The alkoxylated methylol melamine may be one in which at least a part of the methylol group is alkoxylated with a lower alcohol.

As the (g) lower alcohol, one or more of methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol and the like are used.

The practical composition ratio of the α, β-ethylenically unsaturated polycarboxylic acid resin and the alkoxylated methylolmelamine in the matte coating resin composition of the present invention is α, β-ethylenically unsaturated. Polycarboxylic acid resin 5
95 parts by weight, alkoxylated methylol melamine 95-
It can be used in the range of 5 parts by weight.

The matte coating resin composition of the present invention can be produced, for example, by the following method. Stirring device,
In a reaction vessel equipped with a thermometer and a reflux condenser, (a) α,
The β-ethylenically unsaturated polycarboxylic acid resin and (b) alkoxylated methylol melamine are mixed in the presence of an organic solvent. During or after this mixing, a hydrophilic base is added while stirring is continued, and water is further added to emulsify. Then, the temperature is raised to 40 ° C. to the reflux temperature, and stirring is further continued to complete the reaction. The lower the heating temperature, the longer the reaction time and / or the room temperature standing time.

Examples of the organic solvent include alcohols such as methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol, isobutanol, sec-butanol, t-butanol and pentanol, methyl cellosolve, ethyl cellosolve, A cellosolve such as isopropyl cellosolve, butyl cellosolve, sec-butyl cellosolve or the like is used.

As the hydrophilic base, ammonia, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, monobutylamine, dibutylamine,
Alkyl amines such as tributylamine, monoethanolamine, diethanolamine, triethanolamine, mono (2-hydroxypropyl) amine, di (2-hydroxypropyl) amine, tri (2-hydroxypropyl) amine, dimethylaminomethanol , Alkanolamines such as diethylaminomethanol,
Alkylene polyamines such as ethylenediamine, propylenediamine, diethylenetriamine and triethylenetriamine, alkyleneimines such as ethyleneimine and propyleneimine, piperazine, morpholine, piperazine, pyridine, sodium hydroxide, potassium hydroxide, lithium hydroxide and the like. A metal hydroxide is mentioned.

The hydrophilic base may be added in a molar ratio of 0.1 to 0.8 with respect to the carboxyl group of the α, β-ethylenically unsaturated polycarboxylic acid resin. In the matte coating resin composition of the present invention, when an acid is added, the reaction time and the coating film baking time are shortened, and favorable results are obtained. It is presumed that this is because the acid promotes the formation reaction of the reaction product of the α, β-ethylenically unsaturated polycarboxylic acid resin and the alkoxylated methylolmelamine and also acts as a crosslinking catalyst when the coating film is heated and baked. To be done.

Acids that can be added to the resin composition in the present invention include organic acids and / or inorganic acids. Organic acids include formic acid, acetic acid, oxalic acid, sulfonic acid compounds, and the like, while inorganic acids include sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, and the like. In the present invention, at least one kind of organic acid or inorganic acid or a mixture of organic acid and inorganic acid can be used.

In the present invention, the use of an aliphatic sulfonic acid compound is preferable because it exhibits particularly excellent effects. Examples of the sulfonic acid compound include aliphatic sulfonic acid and aromatic sulfonic acid. As the aliphatic sulfonic acid, methanesulfonic acid, alkanesulfonic acid such as ethanesulfonic acid, and as the aromatic sulfonic acid, m-nonylbenzenesulfonic acid, p-decylbenzenesulfonic acid, p-undecylbenzenesulfonic acid, p -Alkylbenzenesulfonic acids such as dodecylbenzenesulfonic acid and p-toluenesulfonic acid, dinonylnaphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, dihexylnaphthalenedisulfonic acid, diheptylnaphthalenedisulfonic acid, dioctylnaphthalenedisulfonic acid, didecylnaphthalenedisulfonic acid , Dialkylnaphthalene sulfonic acid or disulfonic acid is used.

The acid may be compounded arbitrarily, and its addition may be carried out at the time of mixing the film-forming components or after mixing, for example, before the addition of the hydrophilic base. In addition, when the acid is added, it may be added separately at the same time as the hydrophobic base, and in these cases, the same effect as the addition of the acid alone can be obtained.

The reason why the hydrophobic base is used for neutralizing the acid in the present invention is that the acid is usually neutralized by the base to be solubilized, but when the hydrophobic base is used, the acid is hydrophobized even if neutralized. Since such a hydrophobized neutralized product is contained in the resin of the film-forming component, it is not removed even when the paint is subjected to ion exchange treatment, and therefore the amount of acid in the paint does not fluctuate even during continuous operation. This is to keep it small.

The content of the acid or salt is within 10% by weight, preferably within 5% by weight, based on the film forming component of the resin composition,
Particularly preferably, it is suitable to add an amount within 1.0% by weight. This is necessary to retain the excellent physical properties of the resulting matte coating.

As the hydrophobic base, those which are sparingly water-soluble or water-insoluble are particularly preferable. Examples thereof include long-chain alkyl amines and alkyl group-containing amines. The matte coating resin composition of the present invention has a resin solid content of 3 to 5
It can be used in the range of 0% by weight, and may be diluted with water to an appropriate concentration by various coating means before use. At that time, a commonly used colorant and other additives for paints can be mixed and used.

The resin composition for matte coating of the present invention comprises
The gloss of the resulting coating film can be optionally adjusted by mixing with a coating composition that forms a coating film having excellent gloss. By coating an object with the thus prepared matte paint, a uniform matte coating film can be formed regardless of the material, shape and size of the object.

When the object to be coated is coated with the coating composition using the resin composition for matte electrodeposition coating of the present invention, it may be coated by the same method as it is on the conventional electrodeposition coating line. It has an advantage that a uniform matte coating having a stable and low gloss value can be obtained, which is impossible by the method of using the electrodeposition coating and the method of post-treating the electrodeposition coating with a chemical. Further, the obtained matte coating film has excellent adhesion to the object to be coated and also has excellent coating film performance such as acid resistance, alkali resistance and boiling water resistance.

[0030]

EXAMPLES Examples will be shown below to explain the present invention in more detail. However, the present invention is not limited to this. In addition, the part in each example means a weight part.

Production Example 1 [Synthesis Example 1 of component (a)] In a reaction vessel equipped with a stirrer, a thermometer and a reflux condenser, 10 parts of acrylic acid, 15 parts of 2-hydroxyethyl methacrylate, 15 parts of styrene and octyl acrylate. 1
5 parts, butyl acrylate 10 parts, methyl methacrylate 30 parts, vinyl-based silicon macromer X-24-8
5 parts of 200 (manufactured by Shin-Etsu Chemical Co., Ltd.), 1.5 parts of azobisisobutyronitrile, 12 parts of ethylene glycol monobutyl ether and 35 parts of isopropyl alcohol were charged, and the mixture was stirred under reflux for 6 hours to obtain α, β-ethylenic property. Unsaturated polycarboxylic acid resin solution No. 1 (acid value 78) was prepared.

[Synthesis Example 2 of Component (a)] In the same manner as in Synthesis Example 1, 4 parts of acrylic acid, 5 parts of 2-hydroxyethyl acrylate, 15 parts of 2-hydroxyethyl methacrylate, 10 parts of styrene, 1 part of octyl acrylate.
5 parts, butyl acrylate 15 parts, methyl methacrylate 31 parts, vinyl-based silicon macromer X-24-8
5 parts of 200 (manufactured by Shin-Etsu Chemical Co., Ltd.), 1.5 parts of azobisisobutyronitrile, 12 parts of ethylene glycol monobutyl ether, and 35 parts of isopropyl alcohol were stirred at reflux temperature (about 90 ° C.) for 6 hours to obtain α, β-ethylenically unsaturated polycarboxylic acid resin solution No. 2 (acid value about 3
1) was prepared.

[Synthesis example 3 of component (a)] In the same manner as in Synthesis example 1, 15 parts of acrylic acid, 10 parts of 2-hydroxyethyl acrylate, 15 parts of 2-hydroxyethyl methacrylate, 5 parts of ethyl acrylate, and 1 of styrene.
0 part, octyl acrylate 10 parts, methyl methacrylate 30 parts, vinyl silicone macromer X-24-
8200 (manufactured by Shin-Etsu Chemical Co., Ltd.), 1.5 parts of azobisisobutyronitrile, 12 parts of ethylene glycol monobutyl ether, and 35 parts of isopropyl alcohol were stirred at reflux temperature (about 90 ° C.) for 6 hours, and α, β-ethylenically unsaturated polycarboxylic acid resin solution No. 3 (acid value about 117) was prepared.

[Synthesis Example 4 of Component (a)] In the same manner as in Synthesis Example 1, 10 parts of acrylic acid, 15 parts of 2-hydroxyethyl methacrylate, 15 parts of styrene, 15 parts of octyl acrylate, 10 parts of butyl acrylate, and methyl. Methacrylate 35 parts, azobisisobutyronitrile 1.5 parts, ethylene glycol monobutyl ether 12
Part, isopropyl alcohol 35 parts under reflux temperature (about 9
Stirring is carried out for 6 hours at 0 ° C.), and α, β-ethylenically unsaturated polycarboxylic acid resin solution No. 4 (acid value about 78) was prepared.

Example 1 In a reaction vessel equipped with a stirring device, a thermometer and a reflux condenser, the above α, β-ethylenically unsaturated polycarboxylic acid resin solution No. 1 100 parts, methoxybutoxy mixed methylol melamine (trade name MX-40 manufactured by Sanwa Chemical Co., Ltd.)
30 parts were charged and stirred to mix. Next, while continuing stirring, 4.2 parts of triethylamine was added, and then 150 parts of deionized water was further added to emulsify. The emulsified contents were heated to about 90 ° C., stirring was continued for about 12 hours to complete the reaction, and a resin composition was prepared.

Comparative Example 1 A resin composition was obtained in the same manner as in Example 1, except that the emulsion was emulsified and the resulting mixture was stirred at room temperature for 12 hours.

Comparative Example 2 In the method of Example 1, α, β-ethylenically unsaturated polycarboxylic acid resin solution No. 20 parts of ethylene glycol monobutyl ether and 80 parts of isopropyl alcohol when mixed with 1 and methoxybutoxy-mixed methylol melamine
Parts, the contents were heated to about 90 ° C., stirring was continued for about 12 hours, then cooled to room temperature, 10 parts of triethylamine was added and mixed, and then 150 parts of deionized water was further added.
Parts were added to prepare a resin composition.

Comparative Example 3 In the method of Example 1, α, β-ethylenically unsaturated polycarboxylic acid resin solution No. 1 instead of 1. Four
A resin composition was prepared in the same manner except that was used.

Example 2 In the same manner as in Example 1, α, β-ethylenically unsaturated polycarboxylic acid resin solution No. 2 100 parts, methoxybutoxy mixed methylol melamine (trade name MX-4
30 parts (manufactured by Sanwa Chemical Co., Ltd.), and then 0.8 parts of p-dodecylbenzenesulfonic acid was added and mixed. Then, 2.5 parts of triethylamine was added while continuing stirring, and then 150 parts of deionized water was further added to emulsify. The emulsified contents were heated to about 90 ° C., stirring was continued for about 8 hours to complete the reaction, and a resin composition was prepared.

Example 3 A resin composition was prepared in the same manner as in Example 2, except that 0.3 part of p-dodecylbenzenesulfonic acid and 0.2 part of tri-n-butylamine were simultaneously added and blended.

Example 4 In the method of Example 2, p-dodecylbenzenesulfonic acid was replaced with tri-dodecylbenzenesulfonic acid instead of p-dodecylbenzenesulfonic acid.
A resin composition was obtained by the same method except that 0.5 part of a salt obtained by neutralization with n-butylamine was added and the reaction was carried out.

Application Example 1 The resin compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were adjusted to a resin solid content concentration of 10% by weight to prepare a paint for matting coating.
Anodizing treatment is applied to each paint, and an inorganic electrolytically colored aluminum plate is connected to the anode, and an 18-8 austenitic stainless steel plate is connected to the cathode to immerse it.
A voltage was applied, and direct current was applied for 2 minutes at an initial current density of 1.0 A / dm 2. After the electrodeposition coating was completed, each aluminum plate was taken out, washed thoroughly with water, and then dried with hot air at 150 ° C. for 30 minutes.

As a result, the electrodeposition coating film formed on each aluminum plate was as shown in Table 1. And, according to the example of the present invention, the lusterless phenomenon did not occur. On the other hand, in Comparative Example 2, there was a tendency that a lusterless phenomenon occurred.

[0044]

[Table 1]

Example 5 In the same manner as in Example 1, α, β-ethylenically unsaturated polycarboxylic acid resin solution No. 3 100 parts, methoxybutoxy mixed methylol melamine (trade name MX-4
(Manufactured by Sanwa Chemical Co., Ltd.), and then 0.1 part of a salt-containing material obtained in advance from p-dodecylbenzenesulfonic acid and di-n-butylamine was added and mixed. Then, while continuing stirring, add 4 parts of triethylamine,
Further, 150 parts of deionized water was added to emulsify. After heating the emulsified contents to about 90 ° C., stirring was continued for about 4 hours to complete the reaction to prepare a resin composition.

To this resin composition, the resin composition of Comparative Example 1 was added at varying resin solid content ratios as shown in Table 2, thoroughly mixed, and then matte with a resin solid content of 10% by weight, respectively. An anodized aluminum plate, which had been subjected to inorganic electrolytic coloring as an electrodeposition paint in the same manner as in Application Example 1, was subjected to electrodeposition paint. As a result, the gloss value of electrodeposition coating was as shown in Table 2.

[0047]

[Table 2]

Comparative Example 4 A commercially available acrylic-melamine-based electrodeposition coating composition (trade name: Honeylite Al-800) which forms a glossy electrodeposition coating film (gloss value 98).
Honey Chemical Co., Ltd.) undiluted solution [resin solid content 50% by weight] 200
Fine silica powder (trade name Nipseal E-200A,
10 parts (manufactured by Nippon Silica Industry Co., Ltd.) were added and thoroughly mixed and dispersed in a sand mill. Then, deionized water was added to this dispersion to prepare a matte electrodeposition coating composition having a resin solid content of 10% by weight.

The paints prepared in Examples 1 to 5 and Comparative Example 4 were placed in a precipitation tube and allowed to stand at room temperature (25 ° C.) for 1 month to confirm the formation of precipitates. The results are shown in Table 3. Met.

[0050]

[Table 3] However, the precipitate of Comparative Example 4 was hard and could not be redispersed.

[0051]

EFFECTS OF THE INVENTION Since the present invention is constituted as described above, the coating film obtained has an excellent matting effect, does not have a matt-reducing phenomenon, and has almost no fluctuation in gloss over time. It also has excellent surface lubricity and water repellency, resulting in significantly improved dew condensation prevention and scratch resistance,
It is a great place to benefit the industry.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoichi Fujiwara 3-133, Hiyoshi-cho, Nagata-ku, Kobe City, Hyogo Prefecture Honey Kasei Co., Ltd.

Claims (9)

[Claims] 1. A coating film forming component comprising (a) an α, β-ethylenically unsaturated polycarboxylic acid resin containing 0.1 to 10.0% by weight of a vinyl-based silicon macromer and (b) an alkoxylated methylol melamine. A composition containing a product obtained by partially neutralizing the components (a) and (b) with a hydrophilic base, adding water to form an emulsion, and then heating. A matte electrodeposition coating resin composition. 2. The α, β-ethylenically unsaturated polycarboxylic acid resin as the component (a) is (a) α, β-ethylenically unsaturated polycarboxylic acid 3 to 30% by weight, and (b) α, β. 5-30% by weight of hydroxyalkyl-containing ester or amide or amide derivative of ethylenically unsaturated carboxylic acid,
(C) Alkyl ester of α, β-ethylenically unsaturated carboxylic acid 30 to 80% by weight, (D) Vinyl silicon macromer 0.1 to 10.0% by weight, (V) Other copolymerizable monomer 0 to 20% by weight and total amount is 100% by weight
The resin composition for matte electrodeposition coating according to claim 1, which is obtained by reacting a monomer composition blended so that the acid value is 10 to 200. 3. The α, β-ethylenically unsaturated polycarboxylic acid resin as the component (a) is 5 to 95 parts by weight, and the alkoxylated methylolmelamine as the component (b) is 95 to 5 parts by weight. The matte electrodeposition coating resin composition according to 2. 4. An inorganic acid and / or an organic acid is added and mixed at the time of or after mixing the components (a) and (b), and a hydrophilic base and water are added to this to emulsify and then heated. The matte electrodeposition coating resin composition according to claim 1, which is a composition containing the product obtained by the above. 5. A salt component obtained from an inorganic acid and / or an organic acid and a hydrophobic base is added and mixed at the time of or after mixing the components (a) and (b), and a hydrophilic base and water are added thereto. The resin composition for matte electrodeposition coating according to claim 1, 2 or 3, which is a composition containing a product obtained by heating after adding and emulsifying. 6. The resin composition for matte electrodeposition coating according to claim 4, wherein the addition amount of the inorganic acid and / or the organic acid is 10% by weight or less based on the coating film forming component of the resin composition. 7. The matting agent according to claim 5, wherein the addition amount of the salt component obtained from the inorganic acid and / or organic acid and the hydrophobic base is 10% by weight or less based on the coating film forming component of the resin composition. Resin composition for coating. 8. The addition amount of the hydrophilic base is 0.1 to 0.8 in molar ratio with respect to the carboxyl group of the α, β-ethylenically unsaturated polycarboxylic acid resin. The resin composition for matte electrodeposition coating according to item 4. 9. The resin composition for matte electrodeposition coating according to claim 1, which is a composition containing the product obtained by heating at 40 ° C. to the reflux temperature.