JPS6019942B2 - Resin composition for matte coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin composition for matte coating that forms a matte coating.

Conventionally, many methods have been proposed as methods for forming matte coatings.

For example, many coating methods have been used for many years to apply a matte paint in which a fine inorganic powder or a fine organic powder matting agent is dispersed in the paint. On the other hand, in Kame-deposition coating, [1] A method of treating the electrodeposition coating film with an alcohol solution or an alcohol-containing aqueous solution (Hakama Kosho 46-22
351 Publication), [2] A method of treating an unglazed coating film with hot water or heated steam containing or not containing an acid (see Japanese Patent Publication No. 47-51927), {31 Electrodeposition coating film A method of cleaning with a cationic surfactant (see Samurai Publication No. 48-4447), a method of treating the fin coating film before '41 baking with an aqueous solution of an organic or inorganic acid (Japanese Patent Publication No. 14159-1988) (Refer to Publication No. 1416), '5)
After cleaning the electrodeposited coating, it is treated with an aqueous salt solution (see Tokusekki No. 56-9392), or after forming an electroplated coating, it is treated with chemicals to reduce the hardness of the coating. A method of dispersing a disinfectant into a tortoise coating (Tokusei 1973-
16569) and the like are known.

However, the method of treating the coating film with chemicals etc. after forming the electrodeposited coating film does not produce a sufficient matting effect, and the degree of matting changes with changes in the state of the treatment solution, resulting in a uniform matting effect. There is a problem that it is not possible to obtain a stable coating.

Furthermore, since this method adds another step to the conventional electrodeposition coating process, there is the problem of reduced work efficiency, and for these reasons, it has not yet been implemented on a practical scale. . Furthermore, in the case of glaze coating, it is difficult to apply a matte paint containing a kojio agent dispersed therein as is. For example, when using a dew paint in which fine silica powder is dispersed as a matting agent, the fine silica powder tends to settle in the paint, and as a result, the degree of matting on the top and bottom surfaces of the coated object is greatly reduced. Another problem was that the paint itself became unstable. On the other hand, it is known from {6} above to add a solvent-resistant particulate polymerization reaction product to a paint as a matting agent. This method has the advantage that the conventional mechanical refining process such as crushing or dispersing the matting agent is not required, but as in the case of adding the matting agent described above, particulate polymerization occurs in the paint. The tendency for the reaction products to settle is unavoidable, and as a result, there still remains the problem that a uniform glossy coating film cannot be obtained. The present inventors have discovered that, unlike the above-mentioned known techniques, a matte coating film can be formed by simply performing normal painting without dispersing and blending a bee extinguisher or treating the coating film with chemicals. The present invention was completed as a result of repeated research with the aim of obtaining a resin composition for matte coatings.

The present inventors have completed a resin composition for turtle coating that satisfies the above objectives, and have already filed a patent application (Tokuiso Sho 5
No. 6-1974), but the present invention is also an improved invention of this invention.

To summarize the present invention, a resin composition contains {a'Q,8-ethylenically unsaturated polycarboxylic acid resin and {b' alkoxylated methylol melamine as coating film forming components, and this 'a'
This is a resin composition for matte coating, characterized in that it is a composition containing a product obtained by heating an aqueous emulsion containing components '' and 'b'.

According to the research of the present inventors, when Q,6-ethylenically unsaturated polycarboxylic acid resin and alkoxylated methylol melamine are mixed and heated, they do not remain in a mere mixed state, but form Q,8-ethylenically unsaturated polycarboxylic acid. It was confirmed that some reaction products with alkoxylated methylolmelamine were produced.

The resin composition of the aforementioned invention contains as an active ingredient a product obtained by mixing a Q,8-ethylenically unsaturated polycarboxylic acid resin and an alkoxylated methylol melamine in the presence of an organic solvent and heating the mixture. However, when this is used for electroplated coatings, there is a tendency for the so-called matting phenomenon to occur, in which the gloss value of the electrodeposited coating gradually increases due to changes over time, and it is difficult to adjust the gloss of the electrocoated coating. There was a practical problem that it was difficult.

Furthermore, no matte coating film was formed by coating methods other than decoating. The present invention solves the drawbacks of the resin composition of Sakido's invention by Q. B - Ethylenically unsaturated polycarboxylic acid resin and alkoxylated methylol melamine are mixed together to form an aqueous emulsion, which is then heated to dissolve the mixture.
A matte coating film can be formed using any coating method such as tortoise coating, and in particular, when lightning coating is used, no matte phenomenon occurs and the gloss value of the resulting coating film is unobtainable with the resin composition of the previous Iso invention. A value of less than 10% is obtained when measuring the specular gloss. As described above, when the resin composition of the present invention is used, it is possible to obtain an elegant matte coating film appearance with extremely low gloss and fine texture. When the resin composition of the present invention is used as a crab coating paint, the reason why a matte coating film is formed has not yet been investigated, but as mentioned above, the resin composition contains 〇,8-ethylenically unsaturated It is presumed that the presence of a high molecular weight reaction product of the polycarboxylic acid resin and the alkoxylated methylol melamine is involved in the formation of the koji eraser coating.

To explain the present invention in detail, Q,3- used in the present invention
The ethylenically unsaturated polycarboxylic acid resin is
- 3 to 3% by weight of ethylenically unsaturated carboxylic acid,'.

'Hydroxyalkyl-containing ester or amide or amide derivative of Q,3-ethylenically unsaturated carboxylic acid 5
~3% by weight, 30% to 8% by weight of alkyl ester of 1Q,8-ethylenically unsaturated carboxylic acid, 0% to 20% by weight of 8 other copolymerizable monomers, and the total amount is 100% by weight. It is obtained by reacting a monomer composition blended so that it becomes, and preferably has an acid value of 10 to 200.
Suitable Q,B-ethyleneically unsaturated carboxylic acids include acrylic acid, Q-chloroacrylic acid, methacrylic acid, itaconic acid, maleic anhydride, maleic acid, fumaric acid, crotonic acid, citracosonic acid, mesaconic acid. alone or in mixtures, or their functional derivatives having at least one carboxyl group, such as partial esters or amides of unsaturated polymerizable di- or polycarboxylic acids. Next, as the hydroxyalkyl-containing ester or amide or amide derivative of {o}Q,8-ethylene unsaturated carboxylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl 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, alkoxymethylol acrylamide, alkoxymethylol methacrylamide, diacetone acrylamide, diacetone methacrylamide and so on.

Examples of alkyl esters of Q,8-ethylenically unsaturated carboxylic acids include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, and isopropyl methacrylate. Butyl acrylate, butyl methacrylate, lauryl acrylate, lauryl methacrylate,
stearyl acrylate, stearyl methacrylate,
Similar esters having up to about 20 carbon atoms in the alkyl group can be used, such as hexyl acrylate, 2-ethylhexyl methacrylate, heptyl acrylate, heptyl methacrylate, and the like.

Examples of other copolymerizable monomers include styrene, Q-alkylstyrene, Q-chlorostyrene, vinyltoluene, acrylonitrile, and vinyl acetate.

On the other hand, the alkoxylated methylol melamine may be one in which at least a portion of the methylol group is alkoxylated with a lower alcohol.

As the lower alcohol, one or more of methyl alcohol, ethyl alcohol, propyl alcohol, inpropyl alcohol, butyl alcohol, etc. is used. The above-mentioned Q, 3- in the resin composition for matte coating of the present invention
The composition ratio of the unsaturated polycarboxylic acid resin and the alkoxylated methylol melamine can be in the range of 5 to 95 parts by weight of the Q,8-ethylene unsaturated polycarboxylic acid resin and 95 to 5 parts by weight of the alkoxylated methylol melamine.

The resin composition for koji eradication painting of the present invention can be produced, for example, by the following method.

In a reaction vessel equipped with a stirrer, a thermometer, and a reflux condenser, mix 'a}Q,8-ethylenically unsaturated poly1'' carboxylic acid resin and 'b}alkoxylated methylolmelamine in the presence of an organic solvent. .

During or after this mixing, a hydrophilic base is added while stirring, and water is further added to form an emulsion. Next, the temperature is raised to 40° C. to reflux temperature, and stirring is continued to complete the reaction. The lower the heating temperature, the longer the reaction time and/or the room temperature standing time. Examples of organic solvents include methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol, isobutanol, s
Alcohols such as ec-phthanol, t-butanol, bentanol, etc., methyl cellosolve, ethyl cellosolve, inpropyl cellosolve, butyl cellosolve,
Use cellosolve such as sec-butyl cellosolve. Hydrophilic bases include ammonia, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, monobutylamine, dibutylamine,
Alkylamines such as tributylamine, monoethanolamine, diethanolamine, triethanolamine, mono(2-hydroxypropyl)amine, di(2-hydroxypropyl)amine, tri(2-hydroxypropyl)amine, dimethyl Alkaline amines such as aminoethanol and diethylaminoethanol,
In addition to alkylene polyamines such as ethylene diamine, propylene diamine, diethylene triamine, and triethylene tetramine, alkylene imines such as ethylene imine and propylene imine, piperazine, morpholine, pyrazine, and pyridine, sodium hydroxide, potassium hydroxide, lithium hydroxide, etc. Examples include metal hydroxides.

The molar ratio of the hydrophilic base to the carboxyl group of the Q,8-ethylene unsaturated polycarboxylic acid resin is 0.1 to 0.
What is necessary is to add it so that it becomes 8. In the resin composition for koji eradication coating of the present invention, when an acid is added, the reaction time and the coating hardness baking time are shortened, and favorable results can be obtained. This is because the acid promotes the formation of a reaction product between the Q,3-ethylene unsaturated polycarboxylic acid resin and the alkoxylated methylol melamine, and also acts as a catalyst during heating and aggregation of the coating film. It is estimated to be. Acids that can be blended into the resin composition in the present invention include organic acids and/or inorganic acids.

Examples of organic acids include formic acid, acetic acid, oxalic acid, and sulfonic acid compounds, while examples of inorganic acids include sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid. In the present invention, at least one type of organic acid or inorganic acid, or a mixture of an organic acid and an inorganic acid can be used. In the present invention, it is preferable to use a sulfonic acid compound because it exhibits particularly excellent effects.

Sulfonic acid compounds include aliphatic sulfonic acids and aromatic sulfonic acids. As aliphatic sulfonic acid,
Examples of alkanesulfonic acids such as methanesulfonic acid and ethanesulfonic acid, and aromatic sulfonic acids include m-nonylbenzenesulfonic acid, p-decylbenzenesulfonic acid, p-undecylbenzenesulfonic acid, p-dodecylbenzenesulfonic acid, p- Alkylbenzenesulfonic acids such as toluenesulfonic acid, dinonylnaphthalenesulfonic acid, dinonylnaphthalene disulfonic acid, dihexylnaphthalene disulfonic acid, dihebutylnaphthalene disulfonic acid, dioctylnaphthalene disulfonic acid, didecylnaphthalene disulfonic acid, etc.; Use disulfonic acid, etc. The acid may be mixed arbitrarily,
The addition may be carried out at the time of mixing the coating film-forming components or after mixing, for example, before addition of the hydrophilic base.

In addition, when adding an acid, it may be added separately at the same time as the hydrophobic base, or in some cases, a salt-containing substance containing a reaction product with the base may be added. You can get the same effect. The reason why a hydrophobic base is used to neutralize an acid in the present invention is that an acid is normally neutralized by a base and becomes water-soluble, but when a hydrophobic base is used, it becomes hydrophobic even after being neutralized. Since the neutralized product is included in the resin that forms the paint film, it is not removed even if the paint is treated with ion exchange, and therefore, even during continuous operation, fluctuations in the amount of acid in the paint are kept small. It's for a reason.

The acid or salt-containing substance is preferably within 10% by weight, preferably within 5% by weight, particularly preferably 1. It is appropriate to add the amount within % by weight.

This is necessary in order to preserve the excellent physical properties of the resulting matte coating. As the hydrophobic base,
Particularly preferred are those that are poorly water-soluble or water-insoluble.

Examples include long mirror alkyl amines or aralkyl group-containing amines. The resin composition for matte coating of the present invention can be used at a resin solid content concentration of 3 to 5% by weight.
It may be used by diluting it with water to an appropriate concentration using various coating methods.

At that time, commonly used colorants and other paint additives may be mixed and used. Furthermore, the resin composition for matte coating of the present invention can be mixed with a coating composition that forms a coating film with excellent gloss to arbitrarily adjust the gloss of the resulting coating.

When an object is coated with a matte paint prepared in this way, a uniform matte coating can be formed regardless of the material, shape, and size of the object.

Various coating methods such as electrodeposition coating, dipping coating, spray coating, electrostatic coating, gravure coating, roll coating, and brush coating can be applied to the resin composition for matte coating of the present invention.

For fin-deposition painting, it is sufficient to apply the same method on the conventional Kame-deposition painting line, and it is not possible to use a method that uses electrodeposition paint containing a koji eraser or a method that involves post-treatment of the Kame-deposition film with chemicals. It has the advantage that it is always stable and can provide a uniform koji eradication coating film with a low gloss value. Furthermore, the resulting matte coating film has excellent adhesion to the object to be coated, and also has excellent coating properties such as acid resistance, alkali resistance, and boiling water resistance. Examples are shown below to explain the present invention in more detail. However, the present invention is not limited thereto. In addition, parts in each example mean parts by weight.

Production Example 1 [Synthesis Example 1 of Component 'a'] In a reaction vessel equipped with a stirring device, a thermometer, and a reflux condenser, 1 part of acrylic acid, 15 parts of 2-hydroxyethyl methacrylate, 15 parts of styrene, and 15 parts of octyl acrylate were added. 1 part of butyl acrylate, 35 parts of methyl methacrylate, 1.5 parts of azobisisobutyronitrile, 12 parts of ethylene glycol monobutyl ether, and 35 parts of inpropyl alcohol were charged and stirred under reflux for 6 hours. Q, 8-ethylenically unsaturated polycarboxylic acid resin solution shame. 1 (acid value 78)
was prepared.

[Synthesis Example 2 of component {a}] In the same method as Synthesis Example 1, 4 parts of acrylic acid, 5 parts of 2-hydroxyethyl acrylate, 15 parts of 2-hydroxyethyl methacrylate, 1 part of styrene, 15 parts of octyl acrylate 15 parts of butyl acrylate, 36 parts of methyl methacrylate, 1.5 parts of azobisisobutyronitrile, 12 parts of ethylene glycol monobutyl ether
Guo, 35 parts of inpropyl alcohol at reflux temperature (approximately 9
0qo) for 6 hours, and the Q,8-ethylenically unsaturated polycarboxylic acid resin solution M. 2 (acid value approximately 31) was prepared.

[Synthesis Example 3 of Component 'a'] In the same manner as in Synthesis Example 1, 15 parts of acrylic acid, 2-hydro, 1 part of loxethyl acrylate, 1 part of 2-hydroxyethyl methacrylate were added.
5 parts of ethyl acrylate, 1 part of styrene, 1 part of octyl acrylate, 35 parts of methyl methacrylate, 1.5 parts of azobisisobutyronitrile, 12 parts of ethylene glycol monobutyl ether, and 35 parts of isopropyl alcohol at reflux temperature. The Q,3-ethylenically unsaturated polycarboxylic acid resin solution M. was stirred for 6 hours at a temperature of about 9 mm. 3 (acid value approximately 117) was prepared.

Example 1 The above Q,8-ethylenically unsaturated polycarboxylic acid resin solution No. 1 was placed in a reaction vessel equipped with a stirring device, a thermometer and a reflux condenser. 1 10 base parts and 3 sparse parts of methoxybutoxy mixed methylol melamine (trade name MX-40 manufactured by Sanwa Chemical Co., Ltd.) were added and mixed by stirring.

Then, while stirring, triethylamine 4.2
15 parts of deionized water was added to form an emulsion. The emulsified contents were heated to about 90° C. and stirred for about 1 hour to complete the reaction and prepare a resin composition. Comparative Example 1 A resin composition was obtained in the same manner as in Example 1 except that it was emulsified in the same manner as in Example 1 and then stirred briefly at room temperature.

Comparative Example 2 Using the method of Example 1, a Q,8-ethylenically unsaturated polycarboxylic acid resin solution was used. When mixing 1 with methoxybutoxy mixed methylol melamine, 2 parts of ethylene glycol monobutyl ether and 8 parts of inpropyl alcohol were used, and the contents were heated to about 90 qC and stirred for about 1 hour. Thereafter, the mixture was cooled to room temperature, 1 part of triethylamine was added and mixed, and 15 parts of deionized water was further added to prepare a resin composition.

Example 2 In the same method as in Example 1, Q,8-ethylenically unsaturated polycarboxylic acid resin solution No. 2 100 parts, methoxybutoxy mixed methylolmelamine (trade name MX-4
After mixing 30 parts (manufactured by Sanwa Chemical Co., Ltd.), 0.8 part of p-dodecylbenzenesulfonic acid was added and mixed.

Then, while stirring, 2.5 parts of triethylamine was added, followed by an additional 15 parts of deionized water to form an emulsion. Approximately 90% of this emulsified content
The temperature was raised to .degree. C. and stirring was continued for about 8 hours to complete the reaction and prepare a resin composition. 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 The method of Example 2 except that 0.5 part of a salt obtained by neutralizing p-dodecylbenzenesulfonic acid with tri-n-butylamine was added instead of p-dodecylbenzenesulfonic acid, and the reaction was carried out. All resin compositions were obtained by the same method.

Application Example 1 The resin compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 2 were adjusted to a resin solid content concentration of 1% by weight to form a matte coating material.

Each paint was anodized, an aluminum plate colored with inorganic oxidation was connected to the anode, and a stainless steel plate was connected to the cathode. A voltage of 180 volts was applied between the two electrodes, and the initial current density was 1.0 A/d. DC current was applied for 2 minutes. After finishing the coating, each aluminum plate was taken out, thoroughly washed with water, and then dried with hot air at 150°C for 30 minutes. As a result, the electrodeposition coating films formed on each aluminum slope were as shown in Table 1.

In the examples of the present invention, no matting phenomenon occurred. On the other hand, in Comparative Example 2,
There was an area where the matting phenomenon occurred. Table 1 However, (1) and (2) are 600 specular reflectance (JISZ-
8741).

(3) is the pencil traction test (JIS Japan 8602)
by. ■ is adhesion test (JIS H-8602)
by. (5) is based on the 1st generation NaOH 40 hour spot test (JIS H-8602). (6) is 100
℃, 5 hours immersion (JIS H-8602). (7
) is based on a 5% day 2S04 24 hour spot test.
Example 5 In the same manner as in Example 1, a Q,8-ethylenically unsaturated polycarboxylic acid resin solution M. 3 100
After mixing 30 parts of methoxy and butoxy mixed methylolmelamine (trade name MX-40 manufactured by Sanwa Chemical Co., Ltd.),
0.1 part of a salt-containing material previously obtained from p-dodecylbenzenesulfonic acid and di-n-butylamine was added and mixed.

Then, with continued stirring, 4 parts of triethylamine was added, followed by 15 parts of deionized water to form an emulsion. The emulsified contents were heated to about 90 qo and stirred for about 4 hours to complete the reaction and prepare a resin composition. The resin composition of Comparative Example 1 was added to this resin composition at varying resin solid content ratios as shown in Table 2, and after thorough mixing, matte electrodeposition was carried out at 1% by weight of each resin solid content. Electrodeposition coating was performed on an anodized aluminum plate which had been inorganically electrolytically colored using the same method as in Application Example 1.

As a result, the gloss values of the tortoise coated films were as shown in Table 2. Table 2 Example 6 The resin composition 5 for matte coating prepared in Example 4 was treated with a pinychloride-acrylic aqueous treatment solution for surface treatment of synthetic leather (
After mixing 60 parts of the product (trade name: Honeyclone, manufactured by Honey Kasei Co., Ltd.), this was applied to surface-hardened polyvinyl chloride leather using a 120-mesh gravure printer so that the dry film thickness was 10R, and the mixture was heated at 8000 for 30 minutes. Heat drying was performed.

As a result, a polyvinyl chloride leather with a dry texture and a matte appearance was obtained. Comparative Example 3 A commercially available acrylic-melamine electrodeposition paint (trade name: Honeylight Yamaichi 800 manufactured by Honey Kasei Co., Ltd.) that forms a glossy electrodeposition coating film (fake gloss value) stock solution [resin solid content 50% by weight] 20 parts'
1 part of this fine silica powder (trade name: NipSeal E-200A, manufactured by Nippon Silica Kogyo Co., Ltd.) was added to the mixture and sufficiently mixed and dispersed using a sand mill.

Deionized water was then added to this dispersion to prepare a matte electrodeposition coating having a resin solid content of 1% by weight. Each paint prepared in Examples 1 to 5 and Comparative Example 3 was placed in a precipitation tube at room temperature (25 CO
) was left undisturbed for one month and the formation of precipitate was confirmed.
The results were as shown in the table. Table 3 However, the precipitate of Comparative Example 3 was hard and could not be redispersed.

Application example 2 The resin composition obtained in Example 3 was mixed with 5% by weight of resin solids and 1% by weight of resin solids.
and 2% by weight respectively, and spray coating (resin solid content 5% by weight) and roll coating (same 1% by weight)
The aluminum plate, the glass plate, and the polyphenylene sulfide plate were each coated by various coating methods such as , immersion coating (2% by weight), and then dried with hot air at 150° C. for 20 minutes.

In either case, a matte coating film similar to that shown in Application Example 1 was obtained. As is clear from the results of each example above,
The resin composition according to the present invention has remarkable effects in that it has an excellent matting effect, has no matting phenomenon, and has a wide range of applicability for painting.

Claims (1)

[Scope of Claims] 1 A resin composition includes (a) an α,β-ethylenically unsaturated polycarboxylic acid resin and (b) an alkoxylated methylolmelamine as coating film-forming components, and the (a) component and (b)
1. A resin composition for matte coating, characterized in that it is a composition containing a product obtained by heating an aqueous emulsion containing the following components. 2. The resin composition is a composition containing a product obtained by adding a hydrophilic base and water during or after mixing components (a) and (b) to form an emulsion, and then heating the mixture. A resin composition for matte coating according to claim 1. 3. The resin composition is prepared by adding and mixing an inorganic acid and/or an organic acid during or after mixing components (a) and (b),
The resin composition for matte coating according to claim 1, which is a composition containing a product obtained by adding a hydrophilic base and water to emulsion the resin composition and then heating the product. 4 The resin composition is formed by adding and mixing an inorganic acid and/or an organic acid and a hydrophobic base during or after mixing components (a) and (b), and adding a hydrophilic base and water to this to form an emulsion. 2. The resin composition for matte coating according to claim 1, which is a composition containing a product obtained by heating the resin composition. 5 The resin composition is prepared by adding and mixing a salt-containing substance obtained from an inorganic acid and/or an organic acid and a hydrophobic base during or after mixing components (a) and (b), and adding and mixing a salt-containing substance obtained from an inorganic acid and/or an organic acid and a hydrophobic base. Claim 1, which is a composition containing a product obtained by adding and emulsifying water and heating the product.
The resin composition for matte coating described in 2. 6. The matte coating resin according to any one of claims 1 to 5, wherein the resin composition is a composition containing a product obtained by heating at 40°C to reflux temperature. Composition.