JP2007138089A - Anionic electrodeposition coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anionic electrodeposition coating having finishability, weatherability, die mark-masking tendency and new design. <P>SOLUTION: The anionic electrodeposition coating contains 0.01-20 pts.mass of (C) a pigment imparted with leafing property with an average particle size of 5-30 μm and an average thickness of 0.01-0.2 μm based on 100 pts.mass total of solids of (A) a carboxy group-containing resin and (B) a crosslinking agent. Specifically, in this anionic electrodeposition coating, the pigment C is a vacuum-deposited aluminum pigment imparted with leafing property. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an anionic electrodeposition coating material having finish, weather resistance, dice mark concealment and novel design.

  Conventionally, aluminum has better workability at high temperatures than steel and the like, so molds having various cross-sectional shapes can be obtained relatively easily by hot extrusion. In addition, aluminum is increasingly used as a material especially for building materials by utilizing the excellent properties of original aluminum such as light weight, easy workability and excellent corrosion resistance.

  In this method of hot extrusion of aluminum, a cylindrical aluminum ingot is usually heated and melted, and then this melt is put into an extruder and pressed against a die having a hole having a predetermined cross-sectional shape. In this method, a mold having a predetermined shape is obtained by passing through a hole.

  In addition, aluminum itself is not easily corroded by corrosive substances such as salt water resistance, but easily corrodes alkali resistance (such as mortar). In general, the clear coating film is coated. As such an anion electrodeposition coating, for example, a water-soluble resin such as a water-dispersible vinyl copolymer and a melamine resin or a blocked polyisocyanate as a crosslinking agent are known.

  However, when the above anion electrodeposition coating is electrodeposited on an anodized aluminum mold, there is a problem in that the die mark of the aluminum mold is easily noticeable and the commercial value is inferior.

  In addition, in order to make such a dice mark inconspicuous, the present applicant provided an anionic electrodeposition coating material in which a water-soluble acrylic resin and a melamine resin incompatible with these acrylic resins are dispersed in water ( Patent Document 1). However, an anion electrodeposition coating material that satisfies both the performances of forming a coating film that is excellent in coating storage stability and in which the die mark of the aluminum mold material is inconspicuous cannot be obtained.

  In addition, it is disclosed that an anodic deposition electrodeposition coating composition containing a mica having a longitudinal diameter of 30 μm or less or a scaly pigment mainly composed of aluminum is excellent in dice mark concealability and finish. (Patent Document 2). However, a coated article having a new design property has been demanded by a user request.

Japanese Patent Laid-Open No. 10-46065 JP 2001-271032 A

  The problem to be solved is to provide an anionic electrodeposition coating material that is excellent in finish, weather resistance, and dice mark concealing properties, and that provides a new design.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that an anionic electrodeposition coating material containing an aluminum pigment (C) imparted with leafing properties has been obtained, and the present invention has been completed. It came to do.

  The anion electrodeposition paint of the present invention is a paint film obtained by electrodeposition coating of an anion electrodeposition paint, and is a matte paint film in which a dice mark is not conspicuous, excellent in metallic luster, finely textured and like silver A coating film having a high-quality plated appearance is obtained. Moreover, this novel design can be easily obtained by surface treatment (anodized film) by normal secondary electrolytic coloring (etching step-neutralization-anodizing treatment-electrolytic coloring treatment-sealing).

  In the present invention, a carboxyl group-containing resin (A) and a crosslinking agent (B) are used as resin components, and the aluminum pigment (C) imparted with leafing properties to 0.01 parts by mass of the solid content of the resin component is 0.01. By containing ˜20 parts by mass, a coating film having a high-quality feeling like silver can be obtained which is excellent in dice mark concealing property and has a fine metallic luster and texture. Details will be described below.

Carboxyl group-containing resin (A):
The carboxyl group-containing resin is a resin having at least one carboxyl group in one molecule, and preferably having at least one hydroxyl group. Specific examples include resins such as acrylic resins, polyester resins, polyether resins, polycarbonate resins, and urethane resins. Among these, acrylic resins are preferred from the viewpoint of weather resistance. The above acrylic resin is obtained by copolymerizing a carboxyl group-containing radical polymerizable unsaturated monomer, and optionally a hydroxyl group-containing radical polymerizable unsaturated monomer, and other radical polymerizable unsaturated monomers. Can be manufactured.

Examples of the carboxyl group-containing radical polymerizable unsaturated monomer include acrylic acid,
Examples include monomers such as methacrylic acid, crotonic acid, itaconic acid, maleic acid, and fumaric acid. Examples of the hydroxyl group-containing radical polymerizable unsaturated monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate. Other than these, there may be mentioned, for example, Plaxel FM1, Plaxel FM2, Plaxel FM3, Plaxel FA1, Plaxel FA2, Plaxel FA3 (manufactured by Daicel Chemical Industries, trade name, caprolactone-modified (meth) acrylic acid hydroxy ester).

Examples of the other radical polymerizable unsaturated monomer include γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropylmethyldimethoxysilane, and γ- (meth) acryloyloxypropyltriethoxy. Alkoxysilyl group-containing unsaturated monomers such as silane and vinyltrimethoxysilane; for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, (meth ) hexyl acrylate, (meth) acrylate, octyl (meth) acrylate, lauryl (meth) alkyl or cycloalkyl esters of C ₁ -C ₁₈ (meth) acrylic acid such as cyclohexyl acrylate, aromatic such as styrene Group vinyl monomers, amino acid (meth) acrylate , N- butoxymethyl (meth) acrylamide, N- methylol - Le (meth) (meth) acrylamide and its derivatives such as acrylamide, (meth) acrylonitrile compounds, and the like.

As the acrylic resin, usually the above carboxyl group-containing radical polymerizable unsaturated monomer,
It is obtained by subjecting a hydroxyl group-containing radically polymerizable unsaturated monomer and other radically polymerizable unsaturated monomer to a radical polymerization reaction with a polymerization initiator in a solvent as required. In this polymerization reaction, the carboxyl group-containing polymerizable unsaturated monomer is 1 to 20% by mass, preferably 4 to 10% by mass, and the hydroxyl group-containing radical polymerizable unsaturated monomer is 0 to 40% by mass, preferably 5%. The range of -30 mass% and the other radical polymerizable unsaturated monomer is 40-99 mass%, preferably 60-91 mass%.

  Examples of the solvent used for the polymerization reaction include alcohols such as propyl alcohol, isopropyl alcohol, n-butyl alcohol, t-butyl alcohol, isobutyl alcohol, diethylene glycol monobutyl ether, methyl carbitol, 2-methoxyethanol, 2-ethoxy. Ethanol, 2-isopropoxyethanol, 2-butoxyethanol, diethylene glycol, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, 1-methoxy-2-propanol, 1-ethoxy-2-propanol Ethers such as dipropylene glycol monomethyl ether can be preferably used.

Other than this, for example, aromatics such as xylene and toluene; acetone,
Ketones such as methyl ethyl ketone, 2-pentanone, 2-hexanone, methyl isobutyl ketone, isophorone, cyclohexanone; methyl acetate, ethyl acetate, pentyl acetate, 3-methoxybutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, propionic acid Esters such as methyl and ethyl propionate can also be used in combination.

  Examples of the radical polymerization initiator used for radical copolymerization include, for example, benzoyl peroxide, di-t-butyl hydroperoxide, t-butyl hydroperoxide, cumyl peroxide, cumene hydroperoxide, diisopropylbenzan hydroperoxide, Peroxides such as t-butylperoxybenzoate, lauryl peroxide, acetyl peroxide, t-butylperoxy-2-ethylhexanoate, α, α'-azobisisobutylnitrile, azobisdimethylvaleronitrile, azo Examples include azo compounds such as biscyclohexanecarbonitrile. The weight average molecular weight (Note 1) of the acrylic resin produced as described above is in the range of 5,000 to 150,000, preferably 20,000 to 100,000.

(Note 1) Weight average molecular weight: Measured according to JIS K 0124-83.
Chromatograph and polystyrene calibration curve obtained with RI refractometer using SK GEL4000HXL + G3000HXL + G2500HXL + G2000HXL (manufactured by Tosoh Corporation) at 40 ° C. with a flow rate of 1.0 ml / min and eluent using GPC tetrahydrofuran. From the calculation.

Crosslinking agent (B):
As the crosslinking agent, conventionally known compounds can be used. For example, a methylolated amino resin obtained by reacting an amino component such as melamine, urea, benzoguanamine, acetoguanamine, steroguanamine, spiroguanamine, dicyandiamide and an aldehyde. And alkyl etherified products of the methylolated amino resin and block polyisocyanate compounds.

  As the methylolated amino resin, a methylolated melamine resin is preferable, and a part or all of the methylol group of the methylolated melamine resin is one kind of methanol, ethanol, propanol, butanol, octyl alcohol, 2-ethylhexyl alcohol, or the like. A melamine resin modified with two or more monohydric alcohols can be used.

  Commercially available products of the above melamine resins include, for example, Uban 20SE-60, Uban 225 (all are trade names manufactured by Mitsui Chemicals, Inc.), Super Becamine G840, Super Becamine G821 (All are Dainippon Ink. Butyl etherified melamine resins such as Chemical Industry Co., Ltd. (trade name); Sumimar M-100, Sumimar M-40S, Sumimar M-55 (all of which are Sumitomo Chemical Co., Ltd., trade names), Cymel 232, Cymel 303, Cymel 325, Cymel 327, Cymel 350, Cymel 370 (all are made by Nihon Cytec Industries, Inc., trade name), Nicarak MS17, Nicarak MX15, Nicarak MX430, Nicarak MX600 (all are made by Sanwa Chemical Co., Ltd., trade name) ), Regimin 741 (M Methyl etherified melamine resins such as Santo Co., Ltd. (trade name); Cymel 235, Cymel 202, Cymel 238, Cymel 254, Cymel 272, Cymel 1130 (all of which are Mitsui Cytec Co., Ltd., trade name), Summir M66B (Sumitomo) Mixed etherified melamine resin of methylation and isobutylation, etc., manufactured by Kagaku Co., Ltd .; methylation of Cymel XV805 (trade name, manufactured by Mitsui Cytec Co., Ltd.), Nicalac MS95 (trade name, manufactured by Sanwa Chemical Co., Ltd.), etc. And n-butylated mixed etherified melamine resin.

  As the blocked polyisocyanate compound, those obtained by blocking the isocyanate group of a conventionally known polyisocyanate compound with a blocking agent can be used. Examples of the polyisocyanate compound include aliphatic diisocyanates such as hexamethylene diisocyanate or trimethylhexamethylene diisocyanate; cyclic aliphatic diisocyanates such as hydrogenated xylylene diisocyanate or isophorone diisocyanate; tolylene diisocyanate or 4,4'-diphenylmethane diisocyanate. Organic diisocyanates such as aromatic diisocyanates themselves, or adducts of these organic diisocyanates with polyhydric alcohols, low molecular weight polyester resins or water, or cyclized polymers of the respective organic diisocyanates as described above, Furthermore, an isocyanate biuret body etc. are mentioned.

  Examples of commercially available block polyisocyanate compounds include Vernock D-750, -800, DN-950, -970 or 15-455 (trade name, manufactured by Dainippon Ink & Chemicals, Inc.), Desmodur L, N, HL, IL or N3390 (manufactured by Bayer Products), Takenate D-102, -202, -110N or 123N (Takeda Pharmaceutical Company, trade name), Coronate L, HL, EH or 203 (Japan) A polyurethane industry company make, brand name) or Duranate 24A-90CX (Asahi Kasei Kogyo company make, brand name) etc. are mentioned.

  Basic compounds used for neutralization of the carboxyl group-containing resin (A) and the crosslinking agent (B) are ethylamine, propylamine, butylamine, benzylamine, monoethanolamine, neopentanolamine, 2-aminopropanol, 3-aminopropanol, Primary monoamines such as aminopropanol; secondary monoamines such as diethylamidiethanolamine, di-n- or di-iso-propanolamine, N-methylethanolamine, N-ethylethanolamine; dimethylethanolamine, trimethylamine, triethylamine Tertiary monoamines such as triisopropylamine, methyldiethanolamine, dimethylaminoethanol; diethylenetriamine, hydroxyethylaminoethylamine, ethylaminoethylamine, methylaminopropylene Examples include polyamine triethylamine such as ruamine.

  The blending ratio of the basic compound is preferably in the range of 0.1 to 1.2 equivalents as a neutralization equivalent, and the basic compound with respect to the total solid content of the carboxyl group-containing resin (A) and the crosslinking agent (B). Is in the range of 0.01 to 10% by mass, preferably 0.05 to 5% by mass. The aqueous dispersion of the carboxyl group-containing resin (A) can be obtained by adding a crosslinking agent (B), a basic compound and deionized water to the carboxyl group-containing resin (A) and stirring the mixture with a disper or the like. .

Aluminum pigment (C) with leafing properties:
The anionic electrodeposition paint of the present invention is characterized by using an aluminum pigment (C) imparted with leafing properties as a pigment component. The aluminum pigment (C) imparted with leafing properties is obtained by subjecting aluminum to a surface treatment with, for example, a hydrophobic and / or oleophobic agent, and an average particle diameter (Note 2) of 5 to 30 μm, preferably 10 ˜15 μm, average thickness (Note 3) is 0.01 to 0.2 μm, preferably 0.02 to 0.08 μm.
(Note 2) Average particle size: Measurement was carried out after being put into circulating water in a measurement system of a laser diffraction particle size distribution measuring device (Microtrac HRA, manufactured by Honeywell), dispersed with ultrasonic waves for 30 seconds.
(Note 3) Average thickness: The obtained aluminum pigment (C) imparted with leafing properties is uniformly dispersed in a glass plate shape, and the particle size of the particles is measured with a probe microscope (Nanopics 1000, manufactured by Seiko Instruments Inc.). The thickness was measured for 10 pieces, and the average value was defined as the average thickness.
Here, aluminum having a small average particle diameter generally tends to be difficult to obtain high luminance. Therefore, if the average particle size is less than 5 μm, strong metallic luster and high reflectance cannot be obtained. On the other hand, if the average particle size exceeds 30 μm, the fineness of the coating film cannot be obtained, and the particle feeling and The glittery feeling is over-emphasized and a high-quality plating finish like silver cannot be obtained.

  The production method of the aluminum pigment (C) imparted with leafing properties is not particularly limited, and can be produced by a conventionally known method. For example, an aluminum powder is used as a raw material and a ball mill in the presence of an organic solvent. Can be obtained by grinding for a certain time or longer. As the grinding media, conventionally known industrial grinding balls can be used. For example, steel balls or stainless balls having a diameter of 0.3 to 4 mm can be suitably used.

The grinding aid used at the time of grinding is not particularly limited, and conventionally known ones can be used. For example, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, etc. Higher fatty acids, higher unsaturated fatty acids such as oleic acid, higher aliphatic amines such as stearamine, higher aliphatic alcohols such as stearyl alcohol and oleyl alcohol, higher fatty acid amides such as stearic acid amide and oleic acid amide, aluminum stearate And higher fatty acid metal salts such as aluminum oleate. The grinding aid is more preferably 0.1 to 10% by mass, preferably 0.2 to 5% by mass, based on the raw material aluminum powder. The grinding solvent used in the production method is not particularly limited, and conventionally known solvents can be used. For example, hydrocarbon solvents such as mineral spirits and solvent naphtha, alcohols, ethers, and ketones. And ester solvents can be preferably used. Of the above-mentioned solvents, use of a hydrocarbon solvent having a high boiling point such as mineral spirit or solvent naphtha is particularly preferable from the viewpoint of safety.

Furthermore, the amount of grinding solvent with respect to 100 parts by mass of the raw aluminum powder is 250-20.
It is preferably in the range of 00 parts by mass. In addition to the ball mill as described above, a conventionally known grinding device such as an attritor or a vibration mill can be suitably manufactured as the grinding device.
The aluminum pigment (C) imparted with leafing properties is 0.01 to 20 masses relative to 100 mass parts in total of the solid content of the carboxyl group-containing resin (A) and the crosslinking agent (B) in the anionic electrodeposition paint. Parts, preferably 0.02 to 10 parts by mass, more preferably 0.05 to 5 parts by mass. By being within this range, it is a matte coating that ensures paint stability, the die mark is not conspicuous, and has an excellent metallic luster. A coating film having the following is obtained.

  Of the aluminum pigments (C) imparted with leafing properties, vapor deposited aluminum pigments imparted with leafing properties are preferred for obtaining a finely finished finish. For example, as a commercial product, Metacene KM1000 (Toyo Aluminum)).

  The aluminum pigment (C) imparted with the leafing property may be used in combination with other glitter pigments, color pigments, dyes, and the like. Examples of other glitter pigments include aluminum flakes, metal oxide-coated alumina flakes, Metal oxide coated silica flakes, graphite pigments, natural mica (mica) and synthetic mica coated with metal oxides such as iron oxide and titanium oxide, metal oxide coated mica, titanium flakes, stainless steel flakes, oxybismuth chloride, plate Examples thereof include iron oxide pigments, metal-plated glass flakes, metal oxide-coated glass flakes, and hologram pigments, and these can be used alone or in combination of two or more.

  Examples of the color pigment include titanium dioxide, carbon black, zinc white, molybdenum red, Prussian blue, cobalt blue, phthalocyanine pigment, azo pigment, quinacridone pigment, isoindoline pigment, selenium pigment, and perylene pigment. It can be used alone or in combination of two or more.

  Examples of the dye include azo dyes, anthraquinone dyes, indigoid dyes, carbonium dyes, quinoneimine dyes, and phthalocyanine dyes, and these can be used alone or in combination of two or more.

  The blending amount of the other glitter pigments, color pigments and dyes is 0.01 with respect to 100 parts by mass in total of the solid contents of the carboxyl group-containing resin (A) and the crosslinking agent (B) in the anionic electrodeposition paint. The range of -50 parts by mass, preferably 1-30 parts by mass is appropriate.

  The above-mentioned pigment component is prepared by adjusting the type and amount of the pigment according to the target design property, and appropriately adding a pigment-dispersing resin and surfactant water, and sufficiently stirring with a stirrer, or It is preferable to produce a pigment dispersion paste by dispersing it using a ball mill, a sand mill or the like, and use it for the production of an anionic electrodeposition paint.

  Anionic electrodeposition paints can be adjusted to pH by adding a curing catalyst and a surface conditioner, if necessary, in addition to an emulsion in which a carboxyl group-containing resin (A) and a crosslinking agent (B) are dispersed in water, and a pigment dispersion paste. And anionized electrodeposition paint having a solid content of 5 to 20% by mass can be obtained by adding deionized water. Examples of the anion electrodeposition coating material include an anodized aluminum material and a boehmite-treated aluminum material.

  In order to form a coating film using the anionic electrodeposition coating material, the anionic electrodeposition coating material obtained above is used as a bath, and the object to be coated is immersed in this bath, and then 10 to 35 ° C., more preferably Anion electrodeposition coating is carried out at 15 to 30 ° C. with a coating voltage of 100 to 300 V and a dry film thickness of about 5 to 30 μm, and water such as pure water or reverse osmosis membrane (RO) water as required. After washing with water or without washing (non-rinse), or after washing with water (rinsing) and then setting at room temperature, finish (for example, about 160 to 200 ° C. for about 20 to 40 minutes), finish, A weather resistance and a 60-degree specular gloss (see Note 12 below) are 20 or less, so that a coating film having excellent dice mark concealing properties and a novel design can be obtained.

  Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited thereby. “Parts” and “%” indicate “parts by mass” and “% by mass”.

Production Example 1
A ball mill having an inner diameter of 500 mm and a length of 180 mm is filled with 1 kg of atomized aluminum spherical powder having an average particle diameter of 3 μm, 6 L of mineral spirit, and 100 g of oleic acid, and 50 kg of steel balls having a diameter of 1.8 mm are used. Then, the first stage grinding was performed at 33 rpm (corresponding to 55% of the critical rotational speed) over 8 hours.
After the first stage grinding, the slurry in the ball mill was washed out with mineral spirits and solid-liquid separated with a pan filter. After that, 500 g in terms of aluminum metal is returned from the obtained filter cake (non-volatile content: 85%) to the same ball mill with 50 kg of steel balls with a diameter of 1.5 mm, and 5 L of mineral spirit and 100 g of oleic acid are added. Then, the second stage grinding was performed at 40 rpm (corresponding to 67% of the critical rotational speed) over 20 hours.
After the second stage of grinding, the slurry in the ball mill is washed out with mineral spirits, sequentially applied to 400 mesh screen and 500 mesh screen, and the resulting cake is transferred to a kneader mixer and dried at 100 ° C. to improve leafing properties. Aluminum pigment No. assigned 1 was obtained. Aluminum pigment no. 1 had an average particle diameter of 12.8 μm and a particle thickness of 0.045 μm.

Production Example 2 Pigment Dispersion Paste No. Production Example 1 Acrylic resin-based pigment dispersion resin (note 4) 5.5 (solid content 3) having a resin solid content of 55% by mass
Part), aluminum pigment No. 1 obtained in Production Example 1. 2.5 parts of triethylamine and 2.55 parts of deionized water were added, and pigment dispersion paste No. 1 having a solid content of 50% was added. 1 was obtained.
(Note 4) Acrylic resin pigment dispersion resin: an acrylic resin having a carboxyl group having an acid value of 54.5 mgKOH / g, a hydroxyl value of 74.2 mgKOH / g, and a weight average molecular weight of 40,000, and a resin solid content of 55% by mass.

Production Example 3 Pigment Dispersion Paste No. Production Example 2 Acrylic resin-based pigment dispersion resin (Note 4) 5.5 (solid content 3 parts) with a solid content of 55% by mass, 2.5 parts of Metacene KM1000 (Note 5), 0.5 parts of triethylamine, Add 2.55 parts of deionized water and add 50% solids pigment dispersion paste no. 2 was obtained.
(Note 5) Metacene KM1000: manufactured by Toyo Aluminum Co., Ltd., trade name, vapor-deposited aluminum pigment imparted with leafing properties, average particle diameter of 11.1 μm, particle thickness of 0.025 μm.

Production Examples 4 to 10 Pigment dispersion paste No. 3-No. Production Example No. 8 As in Production Example 3, the pigment dispersion paste No. 3-No. 8 was obtained.

(Note 6) 612R: Merck, trade name, gray pearl pigment, average particle size 12.5 μm
(Note 7) MH6601: manufactured by Asahi Kasei Co., Ltd., trade name, paste containing non-leafing aluminum, solid content 65% by weight, average particle size 15.5 μm.

Production Example 11 Production of Acrylic Resin Solution 280 g of isopropyl alcohol was charged into a reaction vessel and maintained at 80 ° C., and 40 g of styrene, 96 g of methyl methacrylate, 28 g of γ-methacryloxypropyltrimethoxysilane, 40 g of n-butyl acrylate, ethyl acrylate A mixture of 120 g, 2-hydroxyethyl acrylate 48 g, acrylic acid 28 g, and azobisdimethylvaleronitrile 8 g was added dropwise over 3 hours, then 4 g of azobisdimethylvaleronitrile was added, and the reaction was maintained at 80 ° C. for 1 hour. And an acrylic resin solution having a resin solid content of 65% by weight was produced. The acrylic resin solution had a weight average molecular weight of about 25,000, an acid value of 55 mgKOH / g, and a hydroxyl value of 58 mgKOH / g.

Production Example 12 Production Example of Emulsion for Anion Electrodeposition Paint
The acrylic resin solution obtained in Production Example 11 was mixed with 0.4 equivalent of triethylamine with respect to a carboxyl group having a solid content of 70 parts (solid content), then mixed and dispersed, and then this was mixed with Nicalac MX600 (Sanwa Chemical). Co., Ltd., trade name, butoxylated melamine resin) 30 parts (solid content) is mixed and dispersed, then deionized water is gradually added dropwise with stirring, and triethylamine is added so that the pH is 7.5. An emulsion for an anionic electrodeposition paint having a solid content of 10% was obtained.

Example 1 Anionic electrodeposition paint No. 1 Production of Emulsion No. 10 for 10% anionic electrodeposition paint obtained in Production Example 12 1 to 1000 parts (resin solids content 100 parts), pigment dispersion paste No. 1 1 was blended with 11 parts (solid content 5.5 parts), 44 parts of deionized water was added, and the anionic electrodeposition paint No. 1 having a solid content of 10% was added. 1 was obtained.

Examples 2-4, Comparative Examples 1-4
The anionic electrodeposition paint Nos. Of Examples 2 to 4 and Comparative Examples 1 to 4 were blended as shown in Table 2 by the same operation as in Example 1. 2-No. 8 was obtained.

Painting method:
Anion electrodeposition paint No. obtained in Examples and Comparative Examples 1-No. 8 was used as a bath, and the object to be coated was subjected to secondary electrolytic treatment (degreasing-etching-neutralization-anodizing treatment-sealing), and an anodized aluminum material having a film thickness of about 10 μm (silver: the size is 150 × 70 × 0.5 mm) was immersed, electrodeposition was applied so that the dry film thickness was 10 μm, washed with water, and baked at 180 ° C. for 30 minutes. The test contents and test results are shown in Table 3.

(Note 8) Paint stability: A paint tube was filled in a test tube (height 20 cm, capacity 20 mL), allowed to stand at 20 ° C. for 7 days, and then the height of the residue precipitated on the bottom of the container was examined.
◎ is good when the residue is 0.5 mm or less,
○, the residue is almost good with 0.6 mm to 5 mm,
△ is a little poor when the residue is 6 mm to 10 mm.
X shows a defect at 11 mm or more.

(Note 9) Finishing property: The surface of the coating film (Yuzu skin, unevenness, etc.) was visually evaluated.
◎ is good,
○ is almost good,
△ is a little bad,
X shows a defect.

(Note 10) Dice mark concealment:
○ indicates good dice mark concealment,
△ is inferior in dice mark concealment,
X is remarkably inferior in dice mark concealment.

  (Note 11) L value: Measured using a variable angle spectrophotometer GCMS-4 (trade name, manufactured by Murakami Color Research Co., Ltd.). Measurement was performed by changing the light receiving angle to 90 degrees with respect to the incident angle of 45 degrees. The larger the L value, the whiter the coating film becomes and the better the dice mark concealing property becomes.

  (Note 12) 60 degree specular glossiness: When the degree of gloss of the multilayer coating film is 60 degrees according to the 60 degree specular glossiness of JIS K-5400 7.6 (1990), respectively. The reflectance was measured and expressed as a percentage when the glossiness of the reference surface of the specular glossiness was taken as 100.

(Note 13) Weather resistance: In accordance with JIS K5400, the gloss of the coating film is measured using a sunshine weatherometer, a carbon arc lamp type accelerated weathering tester, and the gloss retention ratio against the gloss before the exposure test is 80%. The time to divide was measured. Furthermore, the coating film surface was observed visually. ◎: Time for gloss retention to break 80% exceeds 3,000 hours ○: Time for gloss retention to break 80% for 2,500 hours or more and less than 3,000 hours ○ △: Gloss retention The time when the rate is less than 80% is 2,000 hours or more and less than 2,500 hours Δ is the time when the gloss retention is less than 80% is 1,000 hours or more and less than 2,000 hours,
X is less than 1,000 hours when the gloss retention is less than 80%.

With the anion electrodeposition coating material of the present invention, a coated article having excellent dice mark concealability and a novel design can be obtained.

Claims (3)

Aluminum imparted with leafing properties having an average particle diameter of 5 to 30 μm and an average thickness of 0.01 to 0.2 μm with respect to 100 parts by mass of the solid content of the carboxyl group-containing resin (A) and the crosslinking agent (B). An anionic electrodeposition paint containing 0.01 to 20 parts by mass of the pigment (C). The anionic electrodeposition paint according to claim 1, wherein the aluminum pigment (C) imparted with leafing property is a vapor deposited aluminum pigment imparted with leafing property. A matte coated article having a 60-degree specular gloss of less than 20 on the surface of an anodized aluminum substrate coated with the anionic electrodeposition paint according to claim 1 or 2.