JPH09279064A - Water-soluble resin composition - Google Patents

Abstract

(57) Abstract: [PROBLEMS] To provide a resin composition for electrodeposition coating which has excellent lubricity and can obtain a uniform coating film thickness. SOLUTION: The following general formula (I): (In the formula, R is a hydrogen atom or a methyl group, X is an alkylene group or an alkylene oxide group which may have a substituent,
A, Y and Z each represent an alkyl group or a phenyl group which may have a substituent, and n is 0 or 1 to 200.
Is an integer. ) A silicone-containing acrylic acid ester represented by the above) and a silicone-containing acrylic resin obtained by copolymerization of another polymerizable unsaturated monomer copolymerizable with the ester are mixed with a crosslinking agent and then neutralized. A water-soluble resin composition for electrodeposition paint, which comprises an agent.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a water-soluble resin composition for electrocoating having a lubricating property.

[0002]

2. Description of the Related Art Conventionally, sliding parts have been coated with a coating material having a lubricity function. Generally, examples of lubricants that are blended in this type of coating material include polytetrafluoroethylene, fluorine-based surfactants, polyolefin waxes, and silicone resins. A resin coating solution is prepared by dispersing these lubricants using a resin and water or a solvent. Further, by applying these coating solutions to the sliding parts by using a dip coating method or a spray coating method, a coating film is formed on the surface of the sliding parts to impart lubricity. However, in the immersion coating method using the above resin coating, it is not possible to obtain a uniform coating film, and because the affinity between the lubricant and the resin and solvent is weak, agglomerates adhere to the coating tank wall, This agglomerate floats in the solution and adheres to the coating material due to stirring when the coating material such as sliding parts is taken in and out of the coating solution or by circulation of the coating solution, etc. Therefore, there is a problem that the appearance of the coating material is impaired.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems in the prior art, and its object is to have excellent lubricity and a complicated shape. Another object of the present invention is to provide a water-soluble resin composition for an electrodeposition coating composition, which can easily obtain a coating film having a uniform thickness on the above article.

[0004]

Means for Solving the Problems As a result of intensive investigations by the present inventors regarding improvement of a water-soluble resin composition having lubricity, the use of a silicone-containing acrylic monomer results in excellent lubricity. A water-soluble resin composition for an electrodeposition coating composition is obtained, and by performing electrodeposition coating using such a resin composition, the problems occurring in the above-mentioned dip coating method and spray coating method can be solved, and lubricity can be improved. The inventors have found that a uniform coating film can be formed even on an article having a complicated shape that requires the above-mentioned properties, and have completed the present invention.

That is, the water-soluble resin composition for electrodeposition coating composition of the present invention has the following general formula (I):

Embedded image (In the formula, R is a hydrogen atom or a methyl group, X is an alkylene group or an alkylene oxide group which may have a substituent,
A, Y and Z each represent an alkyl group or a phenyl group which may have a substituent, and n is 0 or 1 to 200.
Is an integer. ) A silicone-containing acrylic acid ester represented by the above) and a silicone-containing acrylic resin obtained by copolymerization of another polymerizable unsaturated monomer copolymerizable with the ester are mixed with a crosslinking agent and then neutralized. It is characterized by containing an agent. Further, the silicone-containing acrylic resin in the resin composition for electrodeposition coating composition preferably contains the silicone-containing acrylic ester represented by the general formula (I) in the range of 1 to 30% by weight.

[0006]

Embodiments of the present invention will be described below in detail. The silicone-containing acrylic resin used in the resin composition for electrodeposition coating composition of the present invention includes a silicone-containing acrylic ester represented by the following general formula (I) and other polymerizable unsaturated monomer copolymerizable therewith. It is a copolymer with.

Embedded image (In the formula, R is a hydrogen atom or a methyl group, X is an alkylene group or an alkylene oxide group which may have a substituent,
A, Y and Z each represent an alkyl group or a phenyl group which may have a substituent, and n is 0 or 1 to 200.
Is an integer. In the above general formula (I), the “substituent” in the definition of A, X, Y and Z means an alkyl group, a phenyl group, a halogen atom, a hydroxyl group, an alkoxy group, a keto group, a carboxyl group, an ester group, Amino groups and the like are included.

In the silicone-containing acrylic acid ester represented by the general formula (I) used in the present invention, the silicone portion mainly contributes to the development of lubricity, and other polymerizable unsaturated monomers are used. The part contributes to the coating strength and coating adhesion. Specific examples of the silicone-containing acrylic acid ester include the following compounds.

(Specific examples of silicone-containing acrylic acid ester)

Embedded image

[0009]

Embedded image

In the present invention, in the above general formula (I), R = CH ₃ , X = C ₃ H ₆ , Y = Z = A = CH ₃
And it is preferable to use a silicone macromonomer having a number average molecular weight of about 1000 (Cilaplane FM-0711, manufactured by Chisso Corporation).

In the present invention, various unsaturated compounds can be used as the other polymerizable unsaturated monomer copolymerizable with the silicone-containing acrylic acid ester monomer. First, as specific examples of other polymerizable unsaturated monomers having an acidic moiety, (meth) acrylic acid, maleic acid,
Fumaric acid, itaconic acid, acid phosphooxyethyl (meth) acrylate, acid phosphooxypropyl (meth) acrylate, acid phosphooxypolyoxyethylene glycol mono (meth) acrylate, acid phosphooxypolyoxypropylene glycol mono (meth) acrylate, Examples thereof include vinyl sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, and P-styrene sulfonic acid, and these can be used alone or in admixture of two or more.

Next, specific examples of other polymerizable unsaturated monomers having no acidic site include (meth) acrylic acid esters having 1 to 22 carbon atoms, for example, (meth).
Methyl acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n- (meth) acrylate
Butyl, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxy (meth) acrylate Propyl, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate; 1
Vinyl esters of alkane monocarboxylic acids having ˜12 carbon atoms, such as vinyl acetate, vinyl propionate, vinyl-n-butyrate, vinyl versatate; unsaturated amides or unsaturated imides, such as (meth) Acrylamide, N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, alkoxymethyl (meth) acrylamide, N-butoxymethyl (meth)
Acrylamide, diacetone (meth) acrylamide,
Maleic acid imide, maleic acid diamide; vinyl aromatic monomers such as styrene and P-methylstyrene.

Further, as the other polymerizable unsaturated monomer, any monomer generally having radical polymerizability can be used as the monomer of the present invention. Halogen-containing vinyl compounds such as vinyl, vinylidene chloride and vinylidene fluoride; mono- or diolefins such as ethylene and 1,3-butadiene; α, β-olefinically unsaturated acids such as maleic acid and fumaric acid esters Other examples include (meth) acrylonitrile. These monomers may be used alone or in admixture of two or more.

The silicone-containing acrylic resin used in the present invention is obtained by copolymerizing the silicone-containing acrylic ester represented by the general formula (I) with the above-mentioned other polymerizable unsaturated monomer by a conventional method. It can be manufactured. Obtained silicone-containing acrylic resin (copolymer)
Has a molecular weight in the range of 30,000 to 150,000. In the present invention, for example, by radically polymerizing the above-mentioned monomer mixture in a solution, mixing the obtained silicone-containing acrylic resin varnish with a crosslinking agent, and then neutralizing with a neutralizing agent, A resin composition can be obtained.
The obtained resin composition is mixed with water or the like and used as an electrodeposition coating solution.

The ratio of the silicone-containing acrylic acid ester to the other unsaturated monomer in the silicone-containing acrylic resin is determined in consideration of the balance between the lubricating performance and the copolymerization reactivity of the resulting electrodeposition coating film. However, the proportion of the silicone-containing acrylic acid ester monomer in the silicone-containing acrylic resin used in the present invention is preferably in the range of 1 to 30% by weight. If this proportion is less than 1% by weight, the lubricating performance of the coating film is poor, while if it exceeds 30% by weight, the copolymerization reactivity becomes poor, and
There is no improvement in the lubricating performance of the coating film with increasing content.

A hydrophilic solvent is used as the solvent used in the copolymerization reaction. Specific examples thereof include monohydric alcohols having 1 to 4 carbon atoms, such as methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol and t-butyl alcohol; ethylene glycol and its derivatives, for example Ethylene glycol monomethyl ether, monomethyl ether acetate, monoethyl ether, diethyl ether, monoethyl ether acetate, monoisopropyl ether, monobutyl ether and monobutyl ether acetate; diethylene glycol and its derivatives, for example, diethylene glycol monomethyl ether, monoethyl ether, Monoethyl ether acetate, mono-n-butyl ether, mono-
t-Butyl ether, dimethyl ether, methyl ethyl ether and diethyl ether monoacetate; triethylene glycol and its derivatives, such as triethylene glycol monomethyl ether and monoethyl ether; propylene glycol and its derivatives, such as
Propylene glycol monomethyl ether, monoethyl ether, mono-n-butyl ether, mono-t-butyl ether and methyl ether acetate; dipropylene glycol and its derivatives, such as dipropylene glycol monomethyl ether and monoethyl ether; tripropylene glycol and Derivatives thereof, eg monomethyl ether of tripropylene glycol;
Glycerin and its derivatives, such as glycerin monoacetate; trimethylene glycol and its derivatives,
For example, 1-butoxy-ethoxypropanol, 3,3
-Dimethyl-3-methoxypropanol and 3-methoxybutylacetate; butanediol and its derivatives,
For example, 3-methoxybutanol and 3-methyl-1,
3-butanediol; acetylene glycol derivatives such as 2,4,7,9-tetramethyl-5-decyne 4,
7-diol and its ethylene oxide adduct, 2,
6-Dimethyl-4-octyl-3,6-diol; Others, dioxane, 1,5-pentanediol, hexylene glycol, trimethylolpropane, 1,2,6-
Hexanetriol, low-molecular-weight ethylene glycol and the like can be mentioned, but it is usually preferable to use a monoalkyl ether of ethylene glycol or propylene glycol in combination with a monohydric alcohol having 5 or less carbon atoms. These solvents can be used alone or as a mixture.

As the cross-linking agent in the present invention, melamine resins and the like are used, and as the melamine resin, alkoxylated methylol melamine which is at least partially etherified with a monohydric alcohol such as methanol, ethanol or propanol is used. It is preferable to use. The amount used is 20-based on the silicone-containing acrylic resin.
60% by weight is suitable. The amount of melamine resin used is 20
When the content is less than wt%, the coating film is not sufficiently crosslinked, leading to a decrease in coating film hardness. On the other hand, if it exceeds 60% by weight, there is a problem that the silicone-containing acrylic resin cannot sufficiently exhibit the coating performance because the coating becomes brittle and the stability of the liquid is deteriorated due to excessive crosslinking.

The neutralizing agent used in the aqueous dispersion of the silicone-containing acrylic resin copolymer thus obtained is ammonia and / or amines, and specific examples thereof include diethylamine, triethylamine and monoisopropylamine. , Alkanolamines such as diisopropylamine, triisopropylamine, monobutylamine, dibutylamine and tributylamine, and alkylalkanolamines such as dimethylaminoethanol. The amount of the neutralizing agent used varies depending on the concentration (acid value) of the unsaturated monomer having an acidic site to be used, but is usually in the range of 30 to 120 mol% with respect to the acid group.

[0019]

EXAMPLES The present invention will be described more specifically below with reference to Examples and Comparative Examples. In all of them, “part” means “part by weight”. Example 1 A reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, a nitrogen gas introducing tube and a dropping funnel was charged with 12 parts of ethylene glycol monobutyl ether and 35 parts of isopropyl alcohol, and 90% while introducing nitrogen gas. Under reflux at 0 ° C., the following raw material component mixture (a) was added dropwise by a dropping funnel at a constant speed over 3 hours. Raw material component mixture (a) Silicone-containing acrylic acid ester 2 parts (trade name: Silaplane FM-0711, molecular weight 1000, manufactured by Chisso Corporation) Acrylic acid 10 parts 2-Hydroxyethyl methacrylate 15 parts Styrene 15 parts Octyl acrylate 15 parts Butyl acrylate 10 parts Methyl methacrylate 33 parts Azobisisobutyronitrile 1.5 parts Then, by aging for 3 hours, 147 parts of a silicone-containing acrylic resin having a weight average molecular weight of 95,000 was obtained. Next, 30 parts of methoxybutoxy-mixed methylol melamine (trade name MX-40, manufactured by Sanwa Chemical Co., Ltd.) was added and mixed by stirring, and then 10 parts of triethylamine was added while continuing stirring to obtain a resin composition 187.
Got a part.

(Evaluation of Resin Composition) To 100 parts of the obtained resin composition, 769 parts of deionized water was added to prepare an electrodeposition coating solution. In this electrodeposition coating solution, a hard aluminum plate anodized is connected to the anode and a stainless plate is connected to the cathode to immerse it, and a voltage of 180 V is applied between both electrodes, and the liquid temperature is 20 ° C for 2 minutes. I went. After completion of the electrodeposition coating, the aluminum plate was taken out, sufficiently washed with water, and then dried with hot air at 180 ° C. for 30 minutes, and the film thickness and lubricity of the electrodeposition coating film formed on the aluminum plate were measured. Table 1 shows the results.

Example 2 A resin composition was prepared in the same manner as in Example 1 except that the following raw material component mixture (b) was used in place of the raw material component mixture (a) used in Example 1. Raw material component mixture (b) Silicone-containing acrylic ester 15 parts (trade name: Silaprene FM-0711, molecular weight 1000, manufactured by Chisso Corporation) Acrylic acid 10 parts 2-Hydroxyethyl methacrylate 15 parts Styrene 15 parts Octyl acrylate 15 parts Butyl acrylate 10 parts Methyl methacrylate 20 parts Azobisisobutyronitrile 1.5 parts The film thickness and lubricity of the electrodeposition coating film formed in the same manner as in Example 1 were measured except that the above resin composition was used. .
Table 1 shows the results.

Comparative Example 1 A resin composition was prepared in the same manner as in Example 1 except that the following raw material component mixture (c) was used in place of the raw material component mixture (a) used in Example 1. Raw material component mixture (c) Acrylic acid 10 parts 2-Hydroxyethyl methacrylate 15 parts Styrene 15 parts Octyl acrylate 15 parts Butyl acrylate 10 parts Methyl methacrylate 35 parts Azobisisobutyronitrile 1.5 parts Using the above resin composition The film thickness and lubricity of the electrodeposition coating film formed in the same manner as in Example 1 except for the above were measured.
Table 1 shows the results. Comparative Example 2 The same hard aluminum plate used in Example 1 was used,
Fluorine-based lubricant dispersion (DEFENSA FR-20
0, manufactured by Dainippon Ink and Chemicals, Inc.) for 2 minutes and dried at room temperature. The measurement results of the coating film are also shown in Table 1.

[0023]

[Table 1]

[0024]

EFFECTS OF THE INVENTION The resin composition for electrodeposition coating composition of the present invention is excellent in lubricity by using a silicone-containing acrylic resin copolymer obtained by using a specific silicone-containing acrylic acid ester as a monomer. A thick and uniform coating film can be easily obtained.

Claims (2)

[Claims] 1. A compound represented by the following general formula (I) (In the formula, R is a hydrogen atom or a methyl group, X is an alkylene group or an alkylene oxide group which may have a substituent,
A, Y and Z each represent an alkyl group or a phenyl group which may have a substituent, and n is 0 or 1 to 200.
Is an integer. ) A silicone-containing acrylic acid ester represented by the above) and a silicone-containing acrylic resin obtained by copolymerization of another polymerizable unsaturated monomer copolymerizable with the ester are mixed with a crosslinking agent and then neutralized. A water-soluble resin composition for electrodeposition paint, which comprises an agent. 2. The water for electrodeposition coating composition according to claim 1, wherein the silicone-containing acrylic resin contains the silicone-containing acrylic ester represented by the general formula (I) in the range of 1 to 30% by weight. Soluble resin composition.