JP5913429B2 - Electrodeposition coating composition, electrodeposition coating method, and fluorine-containing coating film - Google Patents

Description

  The present invention relates to an electrodeposition coating composition, an electrodeposition coating method and a fluorine-containing coating film capable of forming a gradient coating film on the surface of an object to be coated.

  Parts for the purpose of protecting and decorating parts in a wide range of industrial products such as home appliances, acoustic equipment, electronic equipment, communication equipment, precision equipment, optical equipment, transportation equipment, leisure and sports equipment, ornaments, furniture, and building materials A protective coating film is formed on the surface. When the object to be coated is a conductive material such as a metal material, it is preferable to form a protective coating film by electrodeposition coating.

  According to electrodeposition coating, an object to be protected is immersed in a bath containing a coating film-forming component to which a charge has been imparted, energized in the bath, and applied to the surface of the object to be coated. A film forming component is deposited and subjected to a baking treatment to form a protective coating film. At this time, if the coating film forming component contains a colorant such as a pigment, it is easy to increase the number of colors of the object to be coated.

  By forming a protective coating film by electrodeposition coating, the durability, surface smoothness, texture, etc. of the object to be coated are improved, and the commercial value of the object to be coated is greatly increased. In addition, it can be applied with a uniform film thickness regardless of the surface shape of the object to be coated, the film thickness can be controlled quantitatively by adjusting the energizing voltage and energizing time, paint loss is low, and the paint can be applied by ultrafiltration. Can be easily recovered. Therefore, electrodeposition coating is counted as one of the important coating techniques in forming a protective film.

  Although a thermosetting resin is used as a coating film forming component of electrodeposition coating in consideration of surface hardness, mechanical strength, etc., the thermosetting resin is generally cured at a very high temperature of 100 ° C. or higher. Is. Such high-temperature curing complicates process management and requires measures from the viewpoint of worker safety. For this reason, a photo-curing electrodeposition coating method has been developed in which a photo-curing coating film-forming component to which an electric charge is applied is used and the coating film is cured by light irradiation such as ultraviolet rays instead of heating.

  The electrodeposition coating composition described in Patent Document 1 contains 30 to 90% by weight of an ultraviolet curable (meth) acrylic resin containing a (meth) acryloyl group and having a weight average molecular weight of 2000 to 30000, and 2 or 2 in one molecule. It is characterized by containing 10 to 70% by weight of a bifunctional or polyfunctional (meth) acrylate containing a higher (meth) acryloyl group as a coating film forming component. By using such an electrodeposition coating composition, it is excellent in wear resistance without increasing the brittleness without impairing the adhesion to the metal plating surface by electrodeposition coating using UV-cured coating. It has high hardness and good surface gloss, and can form an electrodeposition coating film of various colors.

JP 2010-47692 A

  Various improvements are required in the photo-curing electrodeposition coating method, and further improvement in adhesion, scratch resistance, weather resistance, and corrosion resistance to the object is desired for the protective coating film formed by electrodeposition coating. ing.

  An object of the present invention is to provide an electrodeposition coating composition, an electrodeposition coating method, and a fluorine-containing coating film capable of forming a coating film excellent in both properties of adhesion and strength.

The present invention provides a first resin component obtained by polymerizing at least one of a hydroxy derivative of (meth) acrylic acid or an amine derivative of (meth) acrylic acid and a vinyl ester compound containing no fluorine, and photopolymerizability. A first coating composition comprising a first monomer component and a first aqueous solvent, wherein the first resin component and the first monomer component are dispersed in the first aqueous medium;
A second resin component obtained by polymerizing at least one of a hydroxy derivative of (meth) acrylic acid or an amine derivative of (meth) acrylic acid and a vinyl ester compound containing fluorine, a second monomer having photopolymerizability An electrodeposition comprising: a component and a second aqueous solvent, wherein the second resin component and the second monomer component are mixed with a second coating composition dispersed in the second aqueous medium. It is a coating composition.

  In the present invention, the content of the first resin component with respect to the entire first coating composition is 20 to 80% by weight, and the content of the second resin component with respect to the entire second coating composition is It is characterized by being 20 to 80% by weight.

  The present invention also provides a mixing ratio of the first coating composition and the second coating composition, where W1 is the content of the first coating composition and W2 is the content of the second coating composition. W1 / W2 is 0.25-4.

  In the present invention, the vinyl ester compound containing fluorine may be 2- (perfluorooctyl) ethyl acrylate, 2- (perfluorooctyl) ethyl methacrylate, 2- (perfluorobutyl) ethyl acrylate, 2- (perfluoro). (Butyl) ethyl methacrylate, trifluoromethyl acrylate, and trifluoromethyl methacrylate are selected from the group consisting of one or more.

  Further, in the present invention, the first monomer component and the second monomer component include 1,6 hexanediol diacrylate, tripropylene glycol diacrylate, phenoxyethyl acrylate, dipentaerythritol hexaacrylate, trimethylolpropane triacrylate and dipenta It is one type or two or more types selected from the group containing hexamethylene diisocyanate adduct of erythritol acrylate.

  The present invention further includes at least one of a polymerization initiator that accelerates polymerization initiation of the first monomer component and the second monomer component and an ultraviolet absorber that absorbs ultraviolet rays.

In addition, the present invention provides an electrodeposition coating process in which an electrodeposition coating is performed using the above electrodeposition coating composition, and a coating film is formed on the surface of the object to be coated;
And a curing step of curing the coating film by irradiating light to the coating film formed on the surface of the object to be coated.

  In the invention, it is preferable that the object to be coated is any one of a metal material, a semiconductor material, a conductive ceramic material, and a resin material whose surface is subjected to metal plating.

Further, the present invention is a fluorine-containing coating film formed by electrodeposition coating using the above electrodeposition coating composition,
It is a fluorine-containing coating film characterized by having a concentration gradient that increases the fluorine concentration from the surface of the object to be coated to the surface of the coating film.

  According to the present invention, it is an electrodeposition coating composition obtained by mixing a first coating composition and a second coating composition, and the first coating composition is a hydroxy derivative of (meth) acrylic acid or (meth). A first resin component obtained by polymerizing at least one of amine derivatives of acrylic acid and a vinyl ester compound not containing fluorine, a first monomer component having photopolymerizability, and a first aqueous solvent, The resin component and the first monomer component are dispersed in the first aqueous medium, and the second coating composition includes at least one of a hydroxy derivative of (meth) acrylic acid or an amine derivative of (meth) acrylic acid and fluorine. A second resin component obtained by polymerizing a vinyl ester compound containing, a second monomer component having photopolymerizability, and a second aqueous solvent, And the second monomer component, in which are dispersed in the second aqueous medium.

  By setting it as such a composition, in the coating film obtained after electrodeposition coating, it has what is called gradient which the fluorine density | concentration changes to a film thickness direction. Since the coating film has a gradient, it is possible to realize a coating film having excellent adhesion and strength characteristics in one layer.

  According to the invention, the content of the first resin component with respect to the entire first coating composition is 20 to 80% by weight, and the content of the second resin component with respect to the entire second coating composition. The amount is 20-80% by weight.

  According to the present invention, when the content of the first coating composition is W1 and the content of the second coating composition is W2, the first coating composition and the second coating composition The mixing ratio W1 / W2 is 0.25-4.

  According to the invention, as the vinyl ester compound containing fluorine, 2- (perfluorooctyl) ethyl acrylate, 2- (perfluorooctyl) ethyl methacrylate, 2- (perfluorobutyl) ethyl acrylate, 2- ( Perfluorobutyl) ethyl methacrylate, trifluoromethyl acrylate and trifluoromethyl methacrylate can be used alone or in combination of two or more.

  According to the invention, the first monomer component and the second monomer component are 1,6 hexanediol diacrylate, tripropylene glycol diacrylate, phenoxyethyl acrylate, dipentaerythritol hexaacrylate, trimethylolpropane triacrylate and 1 type (s) or 2 or more types selected from the group containing the hexamethylene diisocyanate adduct of dipentaerythritol acrylate can be used.

  Moreover, according to this invention, it can further contain at least any one of the polymerization initiator which accelerates | stimulates the polymerization start of the said 1st monomer component and the said 2nd monomer component, or the ultraviolet absorber which absorbs an ultraviolet-ray.

  Further, according to the present invention, in the electrodeposition coating process, the electrodeposition coating composition is used to perform electrodeposition coating, a coating film is formed on the surface of the object to be coated, and the surface of the object to be coated in the curing process. The coating film formed on is irradiated with light to cure the coating film. Thereby, the coating film which has inclination on the surface of a to-be-coated object can be formed.

  Further, according to the present invention, a metal material, a semiconductor material, a conductive ceramic material, and a resin material whose surface is metal-plated can be used as the object to be coated.

  Further, according to the present invention, there is provided a fluorine-containing coating film formed by electrodeposition coating using the above-mentioned electrodeposition coating composition, wherein the fluorine concentration increases from the surface of the object to be coated to the surface of the coating film. Therefore, it is possible to realize a fluorine-containing coating film that is excellent in both adhesion and strength.

It is a graph which shows the gradient of Example 1,2.

  The electrodeposition coating composition of the present invention is obtained by mixing a first coating composition and a second coating composition, and the first coating composition is composed of a hydroxy derivative of (meth) acrylic acid or (meth) acrylic acid. A first resin component obtained by polymerizing at least one of the amine derivatives and a vinyl ester compound not containing fluorine, a first monomer component having photopolymerizability and a first aqueous solvent, the first resin component and The first monomer component is dispersed in the first aqueous medium, and the second coating composition contains fluorine and at least one of a hydroxy derivative of (meth) acrylic acid or an amine derivative of (meth) acrylic acid. A second resin component obtained by polymerizing the vinyl ester compound, a second monomer component having photopolymerizability, and a second aqueous solvent; The second monomer component, in which are dispersed in the second aqueous medium. In the present invention, “(meth) acrylic acid” means either acrylic acid or methacrylic acid.

[First resin component]
The first resin component is an acrylic resin obtained by polymerizing at least one of a hydroxy derivative of (meth) acrylic acid or an amine derivative of (meth) acrylic acid and a vinyl ester compound not containing fluorine. It is.

  Known hydroxy derivatives of (meth) acrylic acid can be used, such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, Hydroxy derivatives such as 4-hydroxybutyl methacrylate and 2-hydroxy-3-phenoxypropyl acrylate can be used. Among the above-mentioned hydroxy derivatives of (meth) acrylic acid, one can be used alone, or two or more can be used in combination.

  Known amine derivatives of (meth) acrylic acid can be used, such as dimethylaminomethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminoethyl (meth) acrylate. An amino derivative such as di-t-butylaminoethyl (meth) acrylate ethyltrimethylammonium chloride acrylate can be used. Among the above-mentioned amine derivatives of (meth) acrylic acid, one can be used alone, or two or more can be used in combination.

  As the vinyl ester compound not containing fluorine, known compounds can be used, for example, methyl acrylate, methyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate. Benzyl acrylate, benzyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, isobornyl acrylate, 2-acryloyloxyethyl hydrogen phthalate, 2-acryloyloxypropyl hydrogen phthalate, styrene, N-phenylmaleimide, N-cyclohexylmaleimide, polyalkoxysilane acrylate, Use polyalkoxysilane methacrylate, etc. Door can be. Among the above-mentioned vinyl ester compounds not containing fluorine, one kind can be used alone, or two or more kinds can be used in combination.

  The first resin component is obtained by polymerizing these, but may be polymerized with a hydroxy derivative of (meth) acrylic acid and a vinyl ester compound not containing fluorine, and an amine derivative of (meth) acrylic acid and fluorine. May be polymerized with a vinyl ester compound that does not contain, or a hydroxy derivative of (meth) acrylic acid and an amine derivative of (meth) acrylic acid may be polymerized with a vinyl ester compound that does not contain fluorine.

  In addition to the hydroxy derivative of acrylic acid, the amine derivative of (meth) acrylic acid, and the vinyl ester compound not containing fluorine, an alkyl (meth) acrylate compound can be used as a monomer for the synthesis of the first resin component. Specific examples of the alkyl (meth) acrylate compound include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and lauryl (meth). Examples include acrylate, boronyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, and phenoxyethyl (meth) acrylate. In the present invention, any compound having an ethylenically unsaturated double bond (excluding hydroxy derivatives of acrylic acid, amine derivatives of (meth) acrylic acid and vinyl ester compounds not containing fluorine) can be used without any particular limitation. it can. Examples of such compounds include styrene, methyl styrene, vinyl carbazole and the like. Each of the (meth) acrylate compound and the other compound having an ethylenically unsaturated double bond can be used alone or in combination of two or more.

  The first resin component can be polymerized according to a known method. For example, polymerize at least one of a hydroxy derivative of (meth) acrylic acid or an amine derivative of (meth) acrylic acid and a vinyl ester compound containing no fluorine in the presence of a polymerization initiator and heating in a solvent. By making it, the 1st resin component used by this invention is obtained. Here, as the solvent, for example, diethylene glycol monoisopropyl ether can be preferably used. There are no particular restrictions on the amount of solvent used, and it is easy to isolate and purify from the reaction system of the (meth) acrylic resin in which the polymerization reaction proceeds smoothly and depends on the type and amount of compound to be polymerized. An appropriate amount may be selected as appropriate.

  Known polymerization initiators can be used, and examples thereof include azo compounds, disulfide compounds, sulfide compounds, sulfine compounds, nitroso compounds, and peroxide compounds. Specific examples of the polymerization initiator include benzoin peroxide. The amount of the polymerization initiator used is not particularly limited, and a (meth) acrylic resin having a desired degree of polymerization or a weight average molecular weight can be obtained in which the polymerization reaction proceeds smoothly according to the type and amount of the compound to be polymerized. However, it is preferably 0.01 to 3 parts by weight with respect to 100 parts by weight of the monomer compound. Depending on the progress of the polymerization reaction, the polymerization initiator may be added to the polymerization reaction system by dividing it into several times with a time interval. The polymerization reaction is preferably performed at the reflux temperature of the solvent and is completed in about 5 to 20 hours. The resin obtained by the polymerization reaction has a weight average molecular weight (Mw) of 2,000 to 300,000, preferably 15,000 to 150,000. The weight average molecular weight (Mw) is a value obtained by converting a measured value by gel permeation chromatography (GPC) with a calibration curve of monodisperse molecular weight polystyrene (molecular weight 1300, 3000 and 10,000) which is a standard substance.

[Second resin component]
The second resin component is an acrylic resin obtained by polymerizing at least one of a hydroxy derivative of (meth) acrylic acid or an amine derivative of (meth) acrylic acid and a vinyl ester compound containing fluorine. It is.

  As the hydroxy derivative of (meth) acrylic acid, known ones can be used in the same manner as the first resin component. For example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate Hydroxy derivatives such as 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate and 2-hydroxy-3-phenoxypropyl acrylate can be used. Among the above-mentioned hydroxy derivatives of (meth) acrylic acid, one can be used alone, or two or more can be used in combination.

  As the amine derivative of (meth) acrylic acid, known ones can be used in the same manner as the first resin component. For example, dimethylaminomethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate An amino derivative such as diethylaminoethyl (meth) acrylate or di-t-butylaminoethyl (meth) acrylate ethyltrimethylammonium chloride acrylate can be used. Among the above-mentioned amine derivatives of (meth) acrylic acid, one can be used alone, or two or more can be used in combination.

As the vinyl ester compound containing fluorine, known compounds can be used, for example,
Acrylic acid or methacrylic acid such as 2- (perfluorooctyl) ethyl acrylate, 2- (perfluorooctyl) ethyl methacrylate, 2-perfluorobutylethyl acrylate, 2-perfluorobutylethyl methacrylate, trifluoromethyl acrylate, trifluoromethyl methacrylate Acid derivatives such as tetrafluoroethylene, trifluoride ethylene, difluoroethylene, monofluoroethylene, and derivatives thereof can be used. Among the above-mentioned vinyl ester compounds containing fluorine, one can be used alone, or two or more can be used in combination.

  The second resin component can be obtained by polymerizing these, but it may polymerize a hydroxy derivative of (meth) acrylic acid and a vinyl ester compound containing fluorine, and an amine derivative of (meth) acrylic acid and fluorine. May be polymerized, and a hydroxy derivative of (meth) acrylic acid and an amine derivative of (meth) acrylic acid may be polymerized with a vinyl ester compound containing fluorine.

  In addition to the hydroxy derivative of acrylic acid, the amine derivative of (meth) acrylic acid, and the vinyl ester compound containing fluorine, an alkyl (meth) acrylate compound can be used as a monomer for the synthesis of the second resin component. Specific examples of the alkyl (meth) acrylate compound include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and lauryl (meth). Examples include acrylate, boronyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, and phenoxyethyl (meth) acrylate. In the present invention, any compound having an ethylenically unsaturated double bond (except hydroxy derivatives of acrylic acid, amine derivatives of (meth) acrylic acid and vinyl ester compounds containing fluorine) can be used without any particular limitation. it can. Examples of such compounds include styrene, methyl styrene, vinyl carbazole and the like. Each of the (meth) acrylate compound and the other compound having an ethylenically unsaturated double bond can be used alone or in combination of two or more.

  Similar to the first resin component, the second resin component can be polymerized according to a known method. For example, polymerize at least one of a hydroxy derivative of (meth) acrylic acid or an amine derivative of (meth) acrylic acid and a vinyl ester compound containing fluorine in the presence of a polymerization initiator and heating in a solvent. By making it, the 2nd resin component used by this invention is obtained. Here, as the solvent, for example, diethylene glycol monoisopropyl ether can be preferably used. There are no particular restrictions on the amount of solvent used, and it is easy to isolate and purify from the reaction system of the (meth) acrylic resin in which the polymerization reaction proceeds smoothly and depends on the type and amount of compound to be polymerized. An appropriate amount may be selected as appropriate.

  Known polymerization initiators can be used, and examples thereof include azo compounds, disulfide compounds, sulfide compounds, sulfine compounds, nitroso compounds, and peroxide compounds. Specific examples of the polymerization initiator include benzoin peroxide. The amount of the polymerization initiator used is not particularly limited, and a (meth) acrylic resin having a desired degree of polymerization or a weight average molecular weight can be obtained in which the polymerization reaction proceeds smoothly according to the type and amount of the compound to be polymerized. However, it is preferably 0.01 to 3 parts by weight with respect to 100 parts by weight of the monomer compound. Depending on the progress of the polymerization reaction, the polymerization initiator may be added to the polymerization reaction system by dividing it into several times with a time interval. The polymerization reaction is preferably performed at the reflux temperature of the solvent and is completed in about 5 to 20 hours. The resin obtained by the polymerization reaction has a weight average molecular weight (Mw) of 2,000 to 300,000, preferably 15,000 to 150,000. The weight average molecular weight (Mw) is a value obtained by converting a measured value by gel permeation chromatography (GPC) with a calibration curve of monodisperse molecular weight polystyrene (molecular weight 1300, 3000 and 10,000) which is a standard substance.

[Monomer component having photopolymerizability]
The monomer component having photopolymerizability is a monomer component that can be polymerized when irradiated with light in a specific wavelength region. The monomer component having photopolymerization includes a first monomer component used for the first coating composition and a second monomer component used for the second coating composition. The monomer component and the second monomer component are common. Hereinafter, when it is not necessary to distinguish between the first monomer component and the second monomer component, they are simply referred to as monomer components. In the electrodeposition coating composition, the monomer component is solubilized or dispersed in the state of a monomer, and after the coating film is formed on the surface of the object by electrodeposition coating, the coating film is irradiated with light. Polymerizes and the coating is cured.

  Examples of monomer components having photopolymerization properties include polyethylene glycol diacrylate, tripropylene glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, ethylene glycol di (meth) acrylate, Diethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, glycerin di (meth) acrylate, neopentyl glycol di (meth) acrylate, bisphenol A ethylene Bifunctional (meth) acrylate compounds such as oxide-modified diacrylate, lysine isocyanate triacrylate, tolylene diisocyanate trimer triacrylate, hex Methylene diisocyanate trimer triacrylate, trimethylolethane triacrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, isocyanuric acid ethylene oxide modified triacrylate, trimethylolpropane propylene oxide triacrylate, trimethylol Methylolpropane epoxy modified triacrylate, trimethylolpropane ethylene oxide modified triacrylate, pentaglycerol triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol hexaacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythris Tall pentaacrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol tetra (meth) acrylate, trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane triacrylate, glycerol triacrylate, ethoxylated glycerol triacrylate, ethoxylated pentaerythritol tetra Examples thereof include polyfunctional (meth) acrylate compounds having three or more functions such as acrylate glycerin triacrylate, hexamethylene diisocyanate adduct of dipentaerythritol acrylate, and isophorone diisocyanate adduct of dipentaerythritol acrylate. A polyfunctional (meth) acrylate can be used individually by 1 type, or can use 2 or more types together. Further, not only a polyfunctional monomer but also a monofunctional (meth) acrylate such as phenoxyethyl (meth) acrylate having an ethylenically unsaturated double bond can be used in combination as another monomer component. One of the monomer components having photopolymerizability can be used alone or two or more of them can be used in combination.

[Neutralizer]
In order to disperse the first resin component and the second resin component in the aqueous solvent, a neutralizing agent that neutralizes the charges of the first resin component and the second resin component is used. When the first resin component and the second resin component are cationic, an organic acid such as lactic acid, acetic acid, formic acid, succinic acid, or butyric acid or an inorganic acid such as sulfuric acid or phosphoric acid is used as the acid neutralizing agent. it can. When the first resin component and the second resin component are anionic, dimethylamine, trimethylamine, diethylamine, triethylamine, morpholine, pyridine, sodium carbonate, potassium carbonate, sodium hydroxide, water as amine and alkali neutralizer Amines such as potassium oxide or alkali compounds can be used.

  The content of the neutralizing agent contained in the electrodeposition coating composition of the present invention is such that the charge can be neutralized based on the amounts of the first resin component and the second resin component contained in the electrodeposition coating composition. May be added as appropriate.

[Other ingredients]
In addition to the above components, the electrodeposition coating composition of the present invention can use the following components as necessary.

  The electrodeposition coating composition of the present invention may contain a photopolymerization initiator, and examples of the photopolymerization initiator include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy- Cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2- Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 and the like can be used, and one of these can be used alone or two or more can be used in combination. Further, a sensitizer such as isopropylthioxanthone and diethylthioxanthone may be combined.

  When a photopolymerization initiator is included, the amount of photopolymerization initiator used is not particularly limited, and the polymerization reaction proceeds smoothly and has a desired degree of polymerization or a weight average molecular weight depending on the type and amount of monomer components used. Although the quantity which can obtain a (meth) acrylic resin should just be selected suitably, Preferably it is 0.01-3 weight part with respect to 100 weight part of monomer components. Depending on the progress of the polymerization reaction, the photopolymerization initiator may be added to the polymerization reaction system by dividing it into several times with a time interval.

  The electrodeposition coating composition of the present invention may contain an ultraviolet absorber, and examples of the ultraviolet absorber include 2- (2-hydroxy-5-t-butylphenyl) -2H-benzotriazole, 2-methoxy. -1-methylethyl acetate 3- (2H-benzotriazol-2-yl) -5- (1,1-dimethylethyl) -4-hydroxyalkyl ester, 2- (2H-benzotriazol-2-yl) -4 , 6-Bis (1-methyl-1-phenylethyl) phenol, 2- (2H-benzotriazol-2-yl) -6- (1-methyl-1-phenylethyl) -4- (1,1,3 , 3-tetramethylbutyl) phenol, 2,4-bis (2-hydroxy-4-butoxyphenyl) -6- (2,4-dibutoxyphenyl) -1,3-5-triazine, etc. One of these can be used alone, or two or more can be used in combination.

  The electrodeposition coating composition of the present invention may contain a light stabilizer. Examples of the light stabilizer include dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol. Bis (1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] butyl malonate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, methyl 1,2,2,6,6-pentamethyl-4-piperidylsebacate and the like can be used, and one of these can be used alone Or can be used in combination of two or more.

  The electrodeposition coating composition of the present invention may contain a colorant, and examples of the colorant include inorganic pigments and organic pigments. Specific examples of inorganic pigments include, for example, colored pigments such as titanium white (titanium oxide), carbon black, and bengara, extender pigments such as kaolin, talc, aluminum silicate, calcium carbonate, mica, clay, silica, and zinc phosphate. , Iron phosphate, aluminum phosphate, calcium phosphate, zinc phosphite, zinc cyanide, zinc oxide, aluminum tripolyphosphate, zinc molybdate, aluminum molybdate, calcium molybdate, aluminum phosphomolybdate, zinc aluminum phosphomolybdate, etc. Anticorrosive pigments and the like. In addition to these, bismuth compounds described in JP-A Nos. 2000-290542, 2000-230151, and JP-A-11-106687, tungsten oxides described in JP-A-6-220371, etc. Phosphorous acid compounds such as Kaihei 9-241546 can also be used. Specific examples of the organic pigment include phthalocyanine blue, phthalocyanine green, monoazo yellow, disazo yellow, benzimidazolone yellow, quinacridone red, monoazo red, boriazo red, and berylene red.

  The pigment which is a colorant can be used alone or in combination of two or more. For example, when titanium oxide is used, an electrodeposition coating composition having excellent sedimentation stability can be obtained, and an electrodeposition coating film having high whiteness and high hiding power can be formed. Further, when silica or kaolin is used, the repellency prevention property, chipping resistance, coating film hardness, weather resistance, adhesion, rust prevention property, etc. of the electrodeposition coating film can be improved. Moreover, when aluminum phosphate or calcium molybdate is used, the sedimentation stability of the electrodeposition coating composition is improved and the rust prevention property of the electrodeposition coating film is improved.

  When a colorant is included, the content of the colorant is preferably 1 to 60% by weight, more preferably 1 to 30% by weight, based on the total solid content of the electrodeposition coating composition.

  Furthermore, the electrodeposition coating composition of the present invention may contain general additives for electrodeposition coating compositions such as pigment dispersants, surfactants and antioxidants.

[Aqueous solvent]
As an aqueous solvent for solubilizing or dispersing each component, water (including pure water, ultrapure water, ion-exchanged water, etc.) is preferably used, and an organic solvent solubilized in water may be used. The aqueous solvent includes a first aqueous solvent used for the first coating composition and a second aqueous solvent used for the second coating composition. The usable aqueous solvents are the first aqueous solvent and the second aqueous solvent. And is common. Hereinafter, when it is not necessary to distinguish between the first aqueous solvent and the second aqueous solvent, they are simply referred to as an aqueous solvent.

[First coating composition and second coating composition]
The first coating composition essentially comprises a first resin component and a photopolymerizable first monomer component, and if necessary, other components are added, and each component is contained in a first aqueous solvent containing a neutralizing agent. Obtained by dispersing. The second coating composition essentially comprises a second resin component and a second monomer component having photopolymerizability, and if necessary, other components are added, and each component is added to a second aqueous solvent containing a neutralizing agent. Obtained by dispersing.

  In the present invention, the content of the first resin component with respect to the entire first coating composition is 20 to 80% by weight, and the content of the second resin component with respect to the entire second coating composition is 20 to 80% by weight. %. Further, when the content of the first coating composition in the electrodeposition coating composition is W1, and the content of the second coating composition in the electrodeposition coating composition is W2, the first coating composition and W1 / W2, which is the mixing ratio with the second coating composition, is 0.25-4.

[Electrodeposition coating composition]
The electrodeposition coating composition of the present invention is obtained by preparing a first coating composition and a second coating composition in advance and mixing the prepared first coating composition and second coating composition. The fluorine content in the electrodeposition coating composition is 1 to 30% by weight, preferably 3 to 15% by weight in terms of fluorine atoms.

  The solid content concentration of the electrodeposition coating composition is 5 to 30% by weight. If the solid content concentration is out of this range, the dispersion state of each component in the coating becomes unstable, and for example, the aggregation or precipitation of the component occurs, and the appearance defect of the coating film is likely to occur.

  The electrodeposition coating method using the electrodeposition coating composition of the present invention can be carried out in the same manner as the conventional electrodeposition coating method except that the aqueous electrodeposition coating composition of the present invention is used. In the electrodeposition coating method of the present invention, for example, the object to be coated is subjected to degreasing treatment, pickling treatment, etc., if necessary, and then the object to be coated is immersed in the electrodeposition coating composition of the present invention. By performing the electrodeposition coating process for forming an uncured electrodeposition coating film on the surface of the object to be coated, and the object to be coated on which the uncured electrodeposition coating film has been formed, it is contained in the coating film such as ultraviolet rays. And a curing step of curing the electrodeposition coating film on the surface of the object to be coated by irradiating with light having a specific wavelength corresponding to the photopolymerizable monomer.

  A degreasing process is performed by making alkaline aqueous solution contact the surface of a to-be-coated article, for example. The contact with the alkaline aqueous solution is performed, for example, by spraying the alkaline aqueous solution onto the article to be coated or immersing the article to be coated in the alkaline aqueous solution. As the alkali, those commonly used for metal degreasing can be used, and examples include alkali metal phosphates such as sodium phosphate and potassium phosphate. The alkali concentration in the aqueous alkali solution is appropriately determined according to, for example, the type of metal to be treated and the degree of contamination of the metal to be treated. Furthermore, the alkaline aqueous solution may contain an appropriate amount of a surfactant such as an anionic surfactant and a nonionic surfactant.

  The degreasing treatment is performed at a temperature of about 20 to 50 ° C. (liquid temperature of the alkaline aqueous solution) and is completed in about 1 to 5 minutes. After degreasing, the article to be coated is washed with water and subjected to the next pickling process. In addition, degreasing to be immersed in an acidic bath, bubbling immersion degreasing, electrolytic degreasing, and the like can be appropriately combined. The pickling treatment is performed, for example, by bringing an aqueous acid solution into contact with the surface of the article to be coated. The contact with the acid aqueous solution is performed by spraying the acid aqueous solution onto the object to be coated, immersing the object in the acid aqueous solution, or the like, as in the case of the contact with the alkaline aqueous solution in the degreasing treatment. As the acid, those commonly used for metal pickling can be used, and examples thereof include sulfuric acid, nitric acid, and phosphoric acid. The acid concentration in the acid aqueous solution is appropriately determined according to, for example, the type of metal to be treated.

  The pickling treatment is performed at a temperature of about 20 to 30 ° C. (liquid temperature of the acid aqueous solution) and is completed in about 15 to 60 seconds. In addition to the degreasing treatment and pickling treatment, scale removal treatment, ground treatment, rust prevention treatment, and the like may be performed. After these treatments, the article to be coated is dried at a temperature of about 70 to 120 ° C., and is used for the next electrodeposition coating.

  Electrodeposition coating is carried out in accordance with a known method, for example, by immersing the whole object to be coated or a specific part in an energizing tank filled with the electrodeposition coating composition of the present invention to make an anode or a cathode and energizing it. To be implemented. The electrodeposition coating conditions are not particularly limited, and are appropriately selected from a wide range according to various conditions such as the type of metal to be coated, the composition of the electrodeposition coating, the size and shape of the current-carrying tank, and the use of the coating to be obtained. Although it can be selected, the bath temperature (electrodeposition coating composition temperature) is usually about 10 to 50 ° C., the applied voltage is about 10 to 450 V, and the voltage application time is about 1 to 5 minutes.

The object to be electrodeposited is taken out of the energization tank and irradiated with light (for example, ultraviolet rays) to cure the monomer component. Prior to the ultraviolet irradiation, the uncured coating film formed on the surface of the article to be coated may be washed and dried. Although the irradiation amount of an ultraviolet-ray is not restrict | limited in particular, Although it can select suitably from a wide range according to the kind of coating-film component, Preferably it is 200-5000 mJ / cm < ² >. Since the irradiation amount is a product of the irradiation intensity (mJ / cm ² · s) and the irradiation time (s), a desired irradiation amount can be selected by appropriately selecting the irradiation intensity and the irradiation time. As the ultraviolet ray source, for example, a general ultraviolet ray source such as a high-pressure mercury lamp, a chemical lamp, or a metal halide lamp can be used. In this way, a cured electrodeposition coating film is formed on the surface of the object to be coated.

  The object to be formed with an electrodeposition coating on the surface may be any conductive material that can be electrodeposited, such as various metal materials, semiconductor materials such as silicon and indium titanate, conductive ceramic materials, and metal on the surface. A resin material or the like plated can be used.

  The coating film by electrodeposition coating using the electrodeposition coating composition of the present invention has a so-called gradient in which the concentration of the first resin component containing no fluorine and the concentration of the second resin component containing fluorine changes in the film thickness direction. It is obtained as a fluorine-containing coating film. In an uncured state after electrodeposition coating, the resin component is present in a non-uniform amount in the film thickness direction due to differences in physical properties such as surface tension difference, viscosity difference, and glass transition temperature difference of each resin component.

  Small in surface tension is biased toward the surface of the coating, large is concentrated on the surface of the coating, small in viscosity is biased toward the surface of the coating, and large is concentrated on the surface of the coating, glass A higher transition temperature is biased toward the coating film surface, and a lower transition temperature is concentrated on the surface of the object to be coated.

  The first resin component and the second resin component have an affinity for each other, and the first resin component and the second resin component are not separated into two layers in the coating film, and the concentration distribution is in the film thickness direction. Arise. Thereby, the characteristic of a film | membrane can be varied in the outer surface side of a coating film, and the to-be-coated surface side. In general, a surface excellent in strength such as scratch resistance is inferior in adhesiveness, and a surface excellent in adhesiveness is inferior in strength, so it is difficult to satisfy these characteristics with a single coating film. A two-layer coating film that forms a coating film with excellent adhesion on the surface of the object to be coated and forms a coating film with excellent strength on the surface. In some cases, peeling occurs at the interface between the coating films.

  The coating film formed from the electrodeposition coating composition of the present invention can realize a coating film excellent in both adhesion and strength properties by a single layer due to the gradient.

  Curing of the coating film is performed by light irradiation. The photopolymerizable monomer is not inclined and exists uniformly in the coating film, and when irradiated with light, the photopolymerizable monomer is polymerized in a state where the concentrations of the first resin component and the second resin component are inclined, It hardens | cures, with the density | concentration of 1 resin component and 2nd resin component inclined.

  There is no need to bake the coating to cure by light irradiation, and the object to be coated is not exposed to high temperature conditions, so heat sensitive electronic parts, soldered electronic devices, metal plated resin Thus, an electrodeposition coating film as a protective film can be formed.

A practical example of the present invention will be described below.
・ Coating of digital home appliance parts such as mobile phones with metal plating on plastic materials and automotive interior and exterior parts Electrodeposition coating on parts with metal plating on plastic materials, which was impossible with conventional thermosetting paints Therefore, it is possible to realize the formation of a coating film having excellent weather resistance, corrosion resistance, scratch resistance and adhesion strength.

-Protective film in solar cell element The electrodeposition coating composition of the present invention can be applied uniformly and cannot be heated in a mounted state in a complicated shape such as a tile-type solar cell element in household power generation. A coating film can be uniformly formed even on possible components, and a solar cell element having excellent weather resistance, corrosion resistance, adhesion strength, and high light transmittance can be realized.

(Example)
(1) Synthesis of first resin component (1-1) Production example of resin A1 60 g of diethylene glycol monoisopropyl ether is placed in a four-necked flask equipped with a Dimroth reflux tube, and the mixture is heated to reflux. Next, 5 g of methacrylic acid (compound having an ethylenically unsaturated double bond), 20 g of methyl methacrylate (vinyl ester compound not containing fluorine), 30 g of 2-hydroxyethyl methacrylate (hydroxy derivative of methacrylic acid), isobutyl methacrylate (fluorine) 20 g of vinyl ester compound not containing), 25 g of styrene (vinyl ester compound not containing fluorine) and 1 g of benzoin peroxide as a polymerization initiator were added and mixed, and then transferred to a dropping funnel. A dropping funnel is attached to the above-mentioned four-necked flask, and the mixture of the above-mentioned monomer divided into 8 is dropped at intervals of 10 minutes while stirring. The reaction is carried out at a reaction temperature of 70 to 80 ° C. for 5 to 6 hours. Thereafter, 0.1 g of benzoin peroxide was added, and the mixture was refluxed for about 1 hour until the monomer odor disappeared. A light yellow transparent resin A1 solution having a solid content of 70%, a viscosity of 50,000 cps (25 ° C.), and an acid value of 35 Got.

(1-2) Production Example of Resin A2 As monomer components, 10 g of dimethylaminoethyl methacrylate (amine derivative of methacrylic acid), 20 g of methyl methacrylate (vinyl ester compound not containing fluorine), 2-hydroxyethyl methacrylate (hydroxy of methacrylic acid) Derivatives) 25 g, isobutyl methacrylate (vinyl ester compound not containing fluorine) 20 g, and styrene (vinyl ester compound not containing fluorine) 25 g were used in the same manner as Resin A1. A yellow transparent resin A2 solution having a solid content concentration of 70%, a viscosity of 20,000 cps (25 ° C.), and a hydroxyl value of 63 was obtained.

(2) Synthesis of Second Resin Component (2-1) Production Example of Resin B1 As a monomer component, acrylic acid (a compound having an ethylenically unsaturated double bond) 5 g, trimethoxysilane acrylate (ethylenically unsaturated double) 20 g of compound having a bond), 30 g of 2-hydroxyethyl acrylate (hydroxy derivative of acrylic acid), 20 g of 2-ethylhexyl acrylate (vinyl ester compound not containing fluorine), 25 g of perfluoroethyl methacrylate (vinyl ester compound containing fluorine) Except for the above, it was the same as Resin A1. A pale yellow transparent resin B1 solution having a solid content concentration of 70%, a viscosity of 20,000 cps (25 ° C.), and an acid value of 40 was obtained.

(2-2) Production Example of Resin B2 As monomer components, 15 g of n-butyl acrylate (vinyl ester compound containing no fluorine), 25 g of perfluoroethyl methacrylate (vinyl ester compound containing fluorine), 2-hydroxyethyl acrylate ( Resin A1 was used except that 25 g of hydroxy derivative of acrylic acid, 10 g of dimethylaminoethyl methacrylate (amine derivative of methacrylic acid), and 25 g of styrene (compound having an ethylenically unsaturated double bond) were used. A yellow transparent resin solution having a solid content concentration of 70%, a viscosity of 32,000 cps (25 ° C.), and a hydroxyl value of 63 was obtained.

(3) Manufacture of electrodeposition coating composition Each electrodeposition coating composition was manufactured on condition of the following.
(Coating composition A)
-1st resin composition Resin component: Resin A1 35.71g
First monomer component: 1.6 HD 15 g
Other monomer components: PEA 15g
Photopolymerization initiator: Irgacure 907 2.5g
Neutralizer: Triethylamine 1g
Water rolling conditions: The remaining portion was poured into pure water over 2 hours and divided into 10 parts so that the total amount would be 500 ml. Second resin composition Resin component: 35.71 g of resin B1
Second monomer component: DPHA 15 g
: TMPTA 15g
Photopolymerization initiator: Irgacure 907 2.5g
Neutralizer: Triethylamine 1g
Water-transfer conditions: The remainder is divided into 10 portions over 2 hours with pure water so that the total amount becomes 500 ml. It was. The pH of the coating composition A was 7.7, and the electric conductivity was 290 μS / cm.

(Coating composition B)
-1st resin composition Resin component: Resin A2 42.85g
First monomer component: TPGDA 12.5 g
Other monomer components: PEA 12.5 g
Photopolymerization initiator: Irgacure 907 2.5g
UV absorber: Tinuvin 900 1g
Neutralizer: Lactic acid 2g
Water transfer conditions: The remaining portion was poured into pure water over 2 hours and divided into 10 parts so that the total amount would be 500 ml. Second resin composition Resin component: Resin B2 42.85 g
Second monomer component: TMPTA 12.5 g
: DPHA-H 12.5g
Photopolymerization initiator: Irgacure 907 2.5g
UV absorber: Tinuvin 900 1g
Neutralizer: Lactic acid 2g
Water-transfer conditions: The remainder is divided into 10 portions over 2 hours with pure water so that the total amount becomes 500 ml. It was. The pH of the coating composition B was 4.0, and the electrical conductivity was 450 μS / cm.

(Coating composition C)
Resin component: Resin A2 85.71 g
Photopolymerizable monomer component: TPGDA 25 g
Other monomer components: PEA 25g
Photopolymerization initiator: Irgacure 907 5g
UV absorber: Tinuvin 900 2g
Neutralizer: Lactic acid 3g
The remainder was poured into pure water over 2 hours and divided into 10 parts so that the total amount would be 1 L, and a coating composition C was obtained. The pH of the coating composition C was 4.5, and the electrical conductivity was 350 μS / cm.

(Coating composition D)
Resin component: Resin B2 85.71 g
Photopolymerizable monomer component: TMPTA 25 g
: DPHA-H 25g
Photopolymerization initiator: Irgacure 907 5g
UV absorber: Tinuvin 900 2g
Neutralizer: Lactic acid 3g
The remainder was poured into pure water for 2 hours and divided into 10 parts so that the total amount would be 1 L, and a coating composition D was obtained. The pH of the coating composition D was 4.2, and the conductivity was 380 μS / cm.

(Coating composition E)
Resin component: Resin A2 42.85 g
: Resin B2 42.85 g
Photopolymerizable monomer component: TPGDA 12.5 g
: TMPTA 12.5g
: DPHA-H 12.5g
Other monomer components: PEA 12.5 g
Photopolymerization initiator: Irgacure 907 5g
UV absorber: Tinuvin 900 2g
Neutralizer: Lactic acid 6g
The remainder was poured into pure water over 2 hours and divided into 10 parts so that the total amount would be 1 L, and a coating composition E was obtained. The pH of the coating composition E was 4.0, and the electric conductivity was 450 μS / cm.

In addition, about the abbreviation of each component used by said description, it is as follows.
DPHA: dipentaerythritol hexaacrylate TMPTA: trimethylolpropane triacrylate DPHA-H: hexamethylene diisocyanate adduct of dipentaerythritol acrylate 1.6HD: 1,6 hexanediol diacrylate TPGDA: tripropylene glycol diacrylate PEA: phenoxyethyl Acrylate Irgacure 907: 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one (manufactured by BASF)
Tinuvin 900: 2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol (manufactured by BASF)

(4) Example (4-1) Example 1
A SUS304 plate was prepared and subjected to solvent degreasing, alkali degreasing, water washing, acid neutralization, water washing, and pure water washing in this order. In the electrodeposition coating step, the voltage was set using the coating composition A so that the film thickness was 30 μm, and the electrodeposition coating was performed for 1 minute. After electrodeposition coating, it was washed with water and water was removed by air blow.

In the curing step, the coating film was dried at 70 ° C. for 15 minutes and then irradiated with ultraviolet rays at a wavelength of 365 nm and an exposure amount of 4000 mJ / cm ² to cure the coating film.

(4-2) Example 2
The procedure was the same as Example 1 except that the coating composition B was used.

(4-3) Comparative Example 1
Example 1 was repeated except that the coating composition C was used.

(4-4) Comparative Example 2
A coating film having a film thickness of 15 μm was formed using the coating composition C, and a coating film having a film thickness of 15 μm was further formed on the coating film using the coating composition D.
(4-5) Comparative Example 3
Example 1 was repeated except that the coating composition E was used.

(5) Evaluation (5-1) Evaluation Items Evaluation items of the coating film were pencil hardness (JIS K5600), cross-cut peel test (JIS K5600), weather resistance and corrosion resistance test, and scratch depth evaluation by sandblasting. The weather resistance and corrosion resistance tests were performed using a sunshine weather meter (Suga Test Instruments Co., Ltd., WEL-SUN-HC-B type) weather resistance tester, black panel temperature 63 ± 3 ° C., rainfall 12 minutes, irradiation 48 minutes. The cycle was tested. After the test time of 1000 hours, the CASS test (JIS Z2371) was evaluated, and the scratch depth was evaluated by sandblasting (ASTM C-418, silica sand, pressure 2 kg / cm ² , 5 minutes). The gradient of the resin component in the coating film is obtained by taking a cross-sectional photograph with a scanning electron microscope and composing the EDAX (energy dispersive X-ray analyzer) in the vicinity of the object to be coated, the middle portion, and the vicinity of the coating film surface. Analysis was carried out.

(5-2) Evaluation Results Table 1 shows the evaluation results for each evaluation item.

  FIG. 1 is a graph showing the slope of Examples 1 and 2. The horizontal axis represents the distance (μm) in the thickness direction from the SUS304 plate surface, and the vertical axis represents the composition concentration (%). A broken line 1 indicates the first embodiment, and a broken line 2 indicates the second embodiment. Since the film thickness of the coating film is 30 μm, the composition concentration when the distance from the SUS304 plate surface is 10 μm is the composition concentration near the surface of the object to be coated, and the composition concentration when the distance is 20 μm is the middle of the coating film. The composition concentration at the part, and the composition concentration at a distance of 30 μm is the composition concentration in the vicinity of the surface of the coating film.

  As can be seen from FIG. 1, in Examples 1 and 2, the fluorine concentration is changed in the thickness direction of the coating film, and it can be seen that it has a gradient.

  As described above, Examples 1 and 2 were excellent in evaluation results in all of the adhesion to the object to be coated, the scratch resistance, the weather resistance and the corrosion resistance due to the inclination.

  Comparative Example 1 is a coating film composed of only one kind of resin component and does not have a gradient, so that an excellent result was obtained in adhesion, but the scratch resistance, weather resistance and corrosion resistance were poor in practical use. Met.

  Since Comparative Example 2 was a two-layer coating film, excellent results were obtained in scratch resistance, weather resistance and corrosion resistance, but the adhesion was a result of poor practicality.

  In Comparative Example 3, since the resin composition was prepared using the two resin components without preparing the two resin compositions in advance, the gradient was not obtained, and the adhesion, weather resistance, and corrosion resistance were practical. It was a poor result.

Claims (9)

A first resin component obtained by polymerizing at least one of a hydroxy derivative of (meth) acrylic acid or an amine derivative of (meth) acrylic acid and a vinyl ester compound not containing fluorine, a first monomer having photopolymerizability A first coating composition comprising a component and a first aqueous solvent, wherein the first resin component and the first monomer component are dispersed in the first aqueous medium;
A second resin component obtained by polymerizing at least one of a hydroxy derivative of (meth) acrylic acid or an amine derivative of (meth) acrylic acid and a vinyl ester compound containing fluorine, a second monomer having photopolymerizability An electrodeposition comprising: a component and a second aqueous solvent, wherein the second resin component and the second monomer component are mixed with a second coating composition dispersed in the second aqueous medium. Paint composition.   The content of the first resin component with respect to the entire first coating composition is 20 to 80% by weight, and the content of the second resin component with respect to the entire second coating composition is 20 to 80% by weight. The electrodeposition coating composition according to claim 1, wherein the composition is%.   W1 / W2 which is a mixing ratio of the first coating composition and the second coating composition when the content of the first coating composition is W1 and the content of the second coating composition is W2. Is 0.25-4, The electrodeposition coating composition of Claim 1 or 2 characterized by the above-mentioned.   The fluorine-containing vinyl ester compound includes 2- (perfluorooctyl) ethyl acrylate, 2- (perfluorooctyl) ethyl methacrylate, 2- (perfluorobutyl) ethyl acrylate, 2- (perfluorobutyl) ethyl methacrylate, The electrodeposition coating composition according to any one of claims 1 to 3, which is one or more selected from the group comprising trifluoromethyl acrylate and trifluoromethyl methacrylate.   The first monomer component and the second monomer component are 1,6 hexanediol diacrylate, tripropylene glycol diacrylate, phenoxyethyl acrylate, dipentaerythritol hexaacrylate, trimethylolpropane triacrylate, and hexamethylene of dipentaerythritol acrylate. It is 1 type, or 2 or more types chosen from the group containing a diisocyanate adduct, The electrodeposition coating material composition as described in any one of Claims 1-4 characterized by the above-mentioned.   6. The apparatus according to claim 1, further comprising at least one of a polymerization initiator that accelerates polymerization initiation of the first monomer component and the second monomer component and an ultraviolet absorber that absorbs ultraviolet rays. The electrodeposition coating composition described in 1. Electrodeposition coating using the electrodeposition coating composition according to any one of claims 1 to 6, and forming a coating film on the surface of the object to be coated;
And a curing step of curing the coating film by irradiating light onto the coating film formed on the surface of the object to be coated. 8. The electrodeposition coating method according to claim 7 , wherein the object to be coated is any one of a metal material, a semiconductor material, a conductive ceramic material, and a resin material whose surface is subjected to metal plating.
A fluorine-containing coating film formed by electrodeposition coating using the electrodeposition coating composition according to any one of claims 1 to 6,
A fluorine-containing coating film characterized by having a concentration gradient in which the fluorine concentration increases from the surface of an object to be coated.

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