JP2000327986A - Anionic electrodeposition coating material and colored aluminum material obtained by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating material capable of providing a colored aluminum material having an excellent finish by making the coating material including a specific organopolymer. SOLUTION: This anionic electrodeposition coating material contains a hollow organopolymer having 0.01 μm to 1 μm average particle diameter, 0.005 μm to 0.5 μm average inner particle diameter and 0.01-0.9 ratio of the inner particle diameter/the particle diameter in an anionic electrodeposition coating material containing a melamine curing type acrylic resin as a curable resin component. A coating film obtained from the coating material has opacifying properties.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel anionic electrodeposition paint capable of forming a colored electrodeposition coating film and a colored aluminum material.

[0002]

2. Description of the Related Art Conventionally, anodized aluminum substrates are often used in building materials such as sashes because of their light weight, high strength, and excellent corrosion resistance. Also,
The aluminum substrate is usually coated with a clear topcoat electrodeposition coating in order to impart properties such as mortar resistance and stain resistance. In recent years, with the social environment changing drastically, paints are not only intended to provide aesthetics and protect the materials, but also to provide materials with sensibility, luxury, etc. that have departed from the conventional image due to consumer needs. That is the current situation. In the field of building materials such as aluminum sashes, the metallic feeling of aluminum materials is tedious by consumers due to the monotonous color sensation. It has become to. As conventional colored anion electrodeposition paints, white pigments such as titanium white, lead white, zinc white, alumina, zirconia, boron nitride, and white ceramics are used as white pigments. However, the colored anion type electrodeposition paint using the above-mentioned white pigment or white ceramics causes pigment sedimentation, coagulation, etc. in a place where circulation is not sufficient in an electrodeposition bath, and PH temporarily changes during ion exchange. The paint stability becomes worse when the paint is lowered, the electrical load is high when the electricity is applied due to the high paint film resistance, and the wet coating on the substrate is inferior due to the poor wettability to the substrate. However, there are drawbacks such that the film becomes conspicuous and the dilutability with respect to the washing liquid is inferior, and as a result, the finished appearance of the coating and the performance of the coating film (particularly, weather resistance) are inferior. In addition, the dice of the aluminum base material was conspicuous, and the aluminum material did not give a sense of quality, such as a sense of calmness and warmth, or a sense of quality.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a colored anion-type electrodeposition paint capable of solving the above-mentioned problems and a three-dimensional, calm, warmth-like texture and high-grade feel obtained by using the same. It is to provide a colored aluminum material which can be imparted with.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, in particular, an anionic electrodeposition paint containing a conventional melamine-curable acrylic resin as a curable resin component. Average particle size 0.01 μm ~
1 μm, average inner pore diameter 0.005 μm to 0.5 μm, and a finished appearance by using a colored anion electrodeposition coating material containing hollow organic polymer particles having an inner pore diameter / particle diameter ratio of 0.01 to 0.9, The present inventors have found that a coating film excellent in coating film performance and the like can be provided, and have completed the present invention.

That is, the present invention relates to: 1. An anion electrodeposition paint containing a melamine-curable acrylic resin as a curable resin component has an average particle diameter of 0.0
1 μm to 1 μm, average inner pore diameter 0.005 μm to 0.5 μ
m, a colored anion-type electrodeposition paint containing hollow organic polymer particles having an inner pore diameter / particle diameter ratio of 0.01 to 0.9, wherein a coating film formed from the paint has a hiding property. 2. An anionic electrodeposition paint characterized by the fact that the hollow organic polymer fine particles are an acrylic styrene-based polymer; and 3. An anodized aluminum substrate is treated by the anion electrodeposition paint. The electrodeposited paint is applied in the coating material, and then the obtained electrodeposited product is washed with water as necessary, and then baked. 4. The anion-type electrodeposited paint has a cured film thickness of 20 μm. The colored aluminum material having a light transmittance (measuring wavelength 400 nm) of less than 20%.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The anionic electrodeposition coating material used in the present invention is a generally known one, and is formed by crosslinking an acrylic base resin containing a carboxyl group and a hydroxyl group in a skeleton with a melamine resin. And a curable resin composition, and the resin composition is neutralized with a neutralizing agent such as an amine and then dispersed in water. As an acrylic resin,
Examples include a copolymer obtained by subjecting a hydroxyl group-containing acrylic monomer, an ethylenically unsaturated carboxylic acid, and another unsaturated monomer as required to a radical copolymerization reaction.

[0007] These monomer components include the following.

(1) Acrylic monomers containing a hydroxyl group:
For example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, (poly) ethylene glycol mono (meth) acrylate, (poly) propylene glycol mono (Meth) acrylates and the above-mentioned hydroxyl-containing acrylic monomers and β-propiolactone, dimethylpropiolactone, butyrolactone, γ-valerolactone, γ-caprolactone, γ-capryrolactone, γ
As a product name such as a reaction product with a lactone compound such as -laurylolactone, ε-caprolactone, δ-caprolactone, etc., as a trade name, Praxel FM1 (trade name, manufactured by Daicel Chemical Industries, caprolactone-modified (meth) acrylic acid hydroxyester) , Plaxel FM2 (same left), Plaxel FM3 (same left), Plaxel FA-1 (same left), Plaxel FA2 (same left), Plaxel FA3 (same left) and the like.

(2) Ethylenically unsaturated carboxylic acids: for example, (meth) acrylic acid, maleic acid, Placcel F
M1A (hereinafter, manufactured by Daicel Chemical Industries, caprolactone-modified carboxyl group-containing (meth) acrylic monomer, trade name), Praxel FM4A, Praxel FM10A and the like.

(3) Other unsaturated monomers: for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) 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 vinyl monomers - s , (Meta)
(Meth) acrylamides such as acrylamide, N-butoxymethyl (meth) acrylamide, N-methylol (meth) acrylamide and derivatives thereof, and (meth)
Acrylonitrile compounds, etc., alkoxysilyl groups such as γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, vinyltrimethoxysilane Containing vinyl monomers. In these monomer components, a matte electrodeposition coating film can be formed by using an alkoxysilyl group-containing vinyl monomer as another monomer component. The mixing ratio of the alkoxysilyl group-containing vinyl monomer used for forming the matte electrodeposition coating film is about 0.01 to 20% by weight, preferably about 0.1 to 20% by weight in all monomer components. A range of 10% by weight is desirable.

In the mixing ratio of these monomers, the hydroxyl group-containing acrylic monomers may be blended so that the hydroxyl value of the copolymer falls within the range of about 30 to 300 mg KOH / g. The amount of the hydroxyl-containing acrylic monomer is about 3 to 40% by weight, preferably about 5 to 30% by weight in terms of the total amount of the monomers.

The above-mentioned ethylenically unsaturated carboxylic acid may be blended so that the acid value of the copolymer falls within the range of about 10 to 200 mg KOH / g. And the ethylenically unsaturated carboxylic acid ranges from about 3 to 30% by weight, preferably about 4 to 20% by weight.

As other unsaturated monomers, it is preferable to use C ₁ -C ₁₈ alkyl or cycloalkyl esters of (meth) acrylic acid and aromatic vinyl monomers such as styrene. The amount of the monomers is about 37 to 95 based on the total amount of the monomers.
%, Preferably in the range of about 60-91% by weight.

As a method for carrying out a radical copolymerization reaction,
Conventionally known solution polymerization methods can be used. As the cross-linking agent, for example, one obtained by modifying one or more monohydric alcohols such as methanol, ethanol, propanol, butanol, octyl alcohol, and 2-ethylhexyl alcohol in which a part or all of the methylol groups of the melamine resin are used can be used. Can be used. It is preferable that the melamine resin has a mononuclear to polynuclear (about 2 to 5) nucleus content of 50% by weight or more. Further, the melamine resin may contain other functional groups such as an imino group and a methylol group. As the matte electrodeposition coating, C ₁ or more monohydric alcohols, in particular C ₄ -C _{1 8} monohydric alcohol modified with ether group triazine ring 1 nucleus per average of about 2.0 or more, in particular It is preferable to contain 2.0 to 5.0. As the matte electrodeposition paint, C ₃ or more 1
Polyhydric alcohols, in particular C ₄ 1 monohydric alcohol modified ether group triazine in the ring 1 to ₁₈ nuclear per average of about 2.0
It is preferable to contain at least 2.0, especially 2.0 to 5.0. In the paint of the present invention, the mixing ratio of the base resin and the cross-linking agent is such that the base resin is 40
~ 85 wt%, preferably 50-80 wt%, and the crosslinker is 15-60 wt%, preferably 20-50 wt%.
% By weight. 40% by weight of base resin
If the amount of the crosslinking agent exceeds 60% by weight, the coating properties such as weather resistance and workability deteriorate, whereas the blending ratio of the base resin exceeds 85% by weight and the amount of the crosslinking agent falls below 15% by weight. In addition, the coating film performance such as weather resistance, abrasion resistance and workability deteriorates, which is not preferable. The hollow organic polymer fine particles used in the present invention have an average particle size of 0.01 μm to 1 μm.
m, preferably 0.1 μm to 0.7 μm, average inner pore diameter 0.005 μm to 0.5 μm, preferably 0.03 μm
0.3 μm, and the ratio of inner pore diameter / particle diameter is 0.01-0.
9, preferably in the range of 0.1 to 0.7.
When the average particle diameter is less than 0.01 μm, it is not possible to impart whiteness to the coating film, so that a composite colored coating film with a colored aluminum material cannot be formed. On the other hand, when it exceeds 1 μm, the storage stability of the coating material is poor. Become. 0.005 average inner hole diameter
If it is less than μm, it is not possible to impart whiteness to the coating film, so that a composite colored coating film with a colored aluminum material cannot be formed. On the other hand, if it exceeds 1 μm, the storage stability of the coating material deteriorates. When the ratio of inner pore diameter / particle diameter is less than 0.01, it becomes impossible to impart whiteness to the coating film, so that a composite colored coating film with a colored aluminum material cannot be formed.
If it exceeds 0.9, the storage stability of the paint will be poor. The hollow organic polymer fine particles that can be used may have various functional groups such as a carboxyl group, a hydroxyl group, and a glycidyl group on the particle surface as needed. The content of the carboxyl group of the polymer fine particles is about 0 to 100 KOHmg.
/ G, preferably in the range of about 0.1 to 80 KOH mg / g. The carboxyl group has an effect of improving the storage stability of the polymer fine particles in the coating. The content of hydroxyl groups in the polymer fine particles is about 0 to 100 KOHmg /
g, preferably in the range of about 1-80 KOH mg / g. The hydroxyl group reacts with the melamine crosslinking agent and chemically bonds to the curable resin, so that there is an effect that the coating film performance is improved. The hollow organic polymer fine particles are not particularly limited as long as they satisfy the above-mentioned configuration, and conventionally known hollow organic polymer fine particles can be used. As the fine particles, for example,
The following can be mentioned. (1) 100 parts by weight of a polymerizable monomer component composed of 1 to 50% by weight of a crosslinkable monomer, 1 to 99% by weight of a hydrophilic monomer, and 0 to 85% by weight of another polymerizable monomer copolymerizable with the monomer. 1-10 fine particles of a heterogeneous polymer having a composition different from that of a copolymer composed of a reactive monomer component
In the presence of 0 parts by weight, a single inner hole produced in the step of dispersing in an aqueous medium to absorb the polymerizable monomer component into the fine particles of the different polymer, and then polymerizing the polymerizable monomer component, Polymer fine particles (for example, see Japanese Patent Application Laid-Open No. 62-127336). (2) 5 to 70 parts by weight of a hydrophilic monomer, 2 to 20 parts by weight of a crosslinkable monomer, 100 parts by weight of a polymerizable monomer component composed of another polymerizable monomer, and 1 to 1000 of an oily substance
By preparing a dispersion in which the parts by weight coexist, and by heating and polymerizing the monomer component in this dispersion,
Hollow polymer fine particles obtained in the step of producing capsule-shaped polymer particles having single pores filled with the oily substance and the step of removing the oily substance in the polymer particles obtained in the step (for example, 1986-8773
No. 4). (3) (a) solvent-swellable core particles are formed by emulsion-polymerizing at least one ethylenically unsaturated polymerizable monomer in an aqueous medium; And (c) forming a polymer shell around the core particles by emulsion polymerization of at least one ethylenically unsaturated polymerizable monomer, wherein the polymer particles are swollen. The glass transition temperature of the polymeric shell around the inner core is greater than about 50 ° C., and the partition coefficient of the non-aqueous solvent between the inner core and the outer shell is at least about 1.25. Aqueous dispersion of shell particles (JP-A-63-1
No. 35409). The detailed description of the hollow polymer fine particles described above is described in detail in the official gazette. The mixing ratio of the hollow polymer fine particles is preferably about 0.1 to about 100 parts by weight, particularly preferably about 1 to 80 parts by weight, based on 100 parts by weight of the solid content of the anionic electrodeposition paint. If the compounding ratio is less than about 0.1 part by weight, it becomes impossible to impart whiteness to the coating film.
If the amount is more than 00 parts by weight, the storage stability of the coating material deteriorates, which is not preferable. Since the hollow polymer fine particle component has voids inside the particles, it can whiten differently from the conventional titanium white pigment due to light scattering with a large refractive index difference at the polymer and air interface. Due to the weight reduction, sedimentation and coagulation do not occur even in places where circulation is not sufficient in the electrodeposition bath, and the stability of the paint may deteriorate if the pH temporarily decreases during ion exchange. No, high electric load due to high current due to high coating resistance, good wettability to the base material, when applying energized coating in the tank, traces of electrodeposition paint due to the tank become less noticeable, dilution to washing liquid Due to good properties, paint stability, finish appearance and coating performance (particularly weather resistance, etc.) are excellent. The coating containing the hollow polymer fine particle component is hardly noticeable on the aluminum base by forming the coating on the aluminum base of the anodic oxide film, and the die is hardly noticeable due to the extrusion molding of the aluminum base. Texture and luxury. The paint of the present invention may contain, if necessary, a coloring pigment, a dye, a fluidity modifier and the like other than those described above.
The paint of the present invention is a hollow anionic fine particle alone or in combination with other coloring pigments, and is a coloring anion having a concealing property which is blended to such an extent that light passes through the coating film and the color of the base of the aluminum material cannot be substantially distinguished. It can be used as a mold electrodeposition paint. The concealing property is a cured film thickness of 2
Light transmittance at 0 μm (measuring wavelength 400 nm) 20
% Of the present invention, preferably in the range of less than 10%, can be used as glossy and matte paints. The paint of the present invention is preferably applied in the field of aluminum building materials using an anodized aluminum material. A coating method for forming a colored coating film by electrodeposition coating on an anodized aluminum material will be described below. Preferably, the matte electrodeposition coating has a 60 ° specular gloss in the range of about 3 to 60%, more preferably in the range of about 5 to 50%. As a method of coating a matte-colored electrodeposition coating film on the surface of the anodized aluminum material having the anodization film, for example, an electrodeposition coating composition of the present invention is applied to an electrodeposition bath (for example, a solid content of about 5 to 5%).
20% by weight, preferably about 6 to 15% by weight), anion electrodeposition coating is performed in this bath so that the cured film thickness becomes about 10 to 30 μm, and then, if necessary, washed with water and baked (for example, (About 160 to 200 ° C. for about 20 to 40 minutes). As the matte-colored electrodeposition paint, an electrodeposition paint containing an aqueous acrylic copolymer resin having an alkoxysilyl group and a melamine resin as a matte-curable resin component can be used. In particular, because the acrylic copolymer has an alkoxysilyl group in the resin,
When this is dispersed in water, it is hydrolyzed to generate silanol groups, and siloxane bonds are generated by condensation of the silanol groups to form fine dispersion particles having an intraparticle gel structure. Then, the coating film obtained by electrodeposition coating and baking forms a fine rough surface, so that the coating film surface becomes matte, and further contains a gel particle structure due to siloxane bonds in the coating film, and this gel particle Since the refractive index of light passing through the structural part and the other part is different, it cannot be expressed with a coating film using an inorganic matting agent such as barium sulfate fine powder, which has been widely used as a matting agent. It is considered that the color tone was formed. The glossy electrodeposition coating has a 60 ° specular gloss of more than about 60%. The method of coating the glossy colored electrodeposition coating film on the surface of the anodized aluminum material having the anodized film can be performed in the same manner as described above.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to embodiments. The invention is not limited to the embodiments provided.

Production Example of Acrylic Copolymer (a) 70 g of isopropyl alcohol was charged into a reaction vessel and kept at 80 ° C., and 10 g of styrene, 31 g of methyl methacrylate, 10 g of n-butyl acrylate, 30 g of ethyl acrylate, 2-hydroxyethyl acrylate
A mixture of 12 g of acrylic acid, 7 g of acrylic acid, and 2 g of azobisdimethylvaleronitrile was added dropwise over 3 hours, and then 1 g of azobisdimethylvaleronitrile was added.
For 1 hour to produce a reactive varnish (a). The copolymer had a weight average molecular weight of about 20,000 and an acid value of 55 m.
gKOH / g and a hydroxyl value of 58 mgKOH / g.
This copolymer (a) is used for a glossy electrodeposition paint. Production Example of Acrylic Copolymer (b) 70 g of isopropyl alcohol was charged into a reaction vessel and kept at 80 ° C., and 10 g of styrene, 24 g of methyl methacrylate, 7 g of γ-methacryloxypropyltrimethoxysilane, 10 g of n-butyl acrylate, 30 g of ethyl acrylate, 2-hydroxyethyl acrylate
A mixture of 12 g of acrylic acid, 7 g of acrylic acid, and 2 g of azobisdimethylvaleronitrile was added dropwise over 3 hours, and then 1 g of azobisdimethylvaleronitrile was added.
For 1 hour to produce a reactive varnish (b). The copolymer has a weight average molecular weight of about 25,000 and an acid value of 5
5 mgKOH / g and a hydroxyl value of 58 mgKOH / g. This copolymer (b) is used for a matte electrodeposition paint.

Example 1 28 g of the hollow polymer fine particles (I) shown in Table 1 were added to 70 g (solid content) of the copolymer (a), and 0.4 equivalent of triethylamine was used for the carboxyl group of the copolymer (a). Is mixed and dispersed, and then added to the mixture. Nikarac MX600 (trade name, butoxylated melamine resin, manufactured by Sanwa Chemical Co., Ltd .; hereinafter abbreviated as melamine (a)) 30
g and then mixed and dispersed, while stirring, deionized water was gradually added dropwise, and triethylamine was further added to adjust the pH to 8.0 to obtain a glossy white electrodeposition coating composition of Example 1 having a solid content of 10% by weight. Was manufactured. Examples 2 to 6 Glossy white electrodeposition paints were produced in the same manner as in Example 1 using the formulations shown in Table 1. Comparative Example 1 A glossy white electrodeposition paint was produced in the same manner as in Example 1 with the composition shown in Table 1. Example 7 In Example 1, the copolymer (a) was replaced with the copolymer (b).
And Nicaraq MX-600 to Nicaraq MX-4
30 (manufactured by Sanwa Chemical Co., Ltd., trade name, melamine core 1)
Approximately 3 methyl groups, 3 butyl groups per unit, the amount of mononuclear substance is about 57%, and melamine (abbreviated as b)) was used in the same manner as in Example 1 except that the same amount of solid content was used. A matte white electrodeposition paint of 10% by weight was obtained. Examples 8 to 12 Matting white electrodeposition paints were produced in the same manner as in Example 7 using the formulations shown in Table 1. Comparative Example 2 A matte white electrodeposition paint was produced in the same manner as in Example 7 with the composition shown in Table 1. In Table 1, the hollow polymers are as follows. Hollow polymer I: particle diameter 0.39 μm, inner pore diameter 0.17
μm, inner pore diameter / particle ratio 0.44 hollow polymer II: particle diameter 0.39 μm, inner pore diameter 0.27
μm, inner pore diameter / particle ratio 0.69 hollow polymer III: particle diameter 0.39 μm, inner pore diameter 0.0
8 μm, inner pore diameter / particle ratio 0.21 hollow polymer IV: particle diameter 0.68 μm, inner pore diameter 0.18
μm, inner pore diameter / particle ratio 0.26 Hollow polymer V: particle diameter 0.30 μm, inner pore diameter 0.20
μm, inner pore diameter / particle ratio 0.67 Table 1 shows the performance of the paints of the above Examples and Comparative Examples, and the appearance and performance of the paint films. Table 1

In Table 1, the evaluation was performed based on the following criteria. The test evaluation of paint storage stability and coating film appearance is as follows. Paint storage stability: The paint was placed in a test tube (height 20 cm, capacity 2).
0 cc) and allowed to stand at 20 ° C. for 7 days, and then the height of the residue settled at the bottom of the container was examined. ◎ indicates no residue, は indicates that the residue is 0.1 mm to 0.5 mm, which is almost good, Δ indicates that the residue is 0.6 mm to 4.9 mm, and is poor, and X indicates that the residue is 5 mm or more, which is extremely poor. Method for forming a coating film The electrodeposition coating material obtained above was used as an electrodeposition bath, and anodized aluminum material was subjected to electrodeposition coating in the electrodeposition bath so that a cured film thickness was about 20 μm. For 30 minutes to obtain a colored aluminum material. Appearance: The color appearance of the coating film was visually observed. Good quality with a sense of quality such as three-dimensional feeling, calmness, warmth, and luxury, and poor quality and quality such as three-dimensional feeling, calmness, warmth, etc. Specular reflectance: 60 degrees of JIS K-5400 Specular reflectance was measured. Smoothness: The surface of the coating film (e.g., skin, unevenness, etc.) was visually evaluated. ◎: good, は: almost good, Δ: slightly poor, x: poor Color tone: Measured according to JIS Z-8730 (L value according to L * a * b * color system). Stripe resistance: The gloss change due to stripes (coating lines) was visually examined. ◎ indicates good, は indicates almost good, 不良 indicates slightly poor, and × indicates defective. Influence of the substrate: ○ indicates that the material has inconspicuous dice, ×
Is the one where the base dice are noticeable.

[0019]

EFFECTS OF THE INVENTION Since the present invention has the above-mentioned structure, it does not cause pigment sedimentation or aggregation in a place where circulation is not sufficient in an electrodeposition bath, and paints when pH temporarily decreases during ion exchange. Stability does not deteriorate, the electrical load due to energization is small due to high coating resistance,
Since the wettability to the base material is inferior, when the energized paint is applied to the tank, the trace of the electrodeposition paint due to the tank is inconspicuous, the dilutability to the washing liquid is excellent, and the finished paint appearance and coating performance (especially weather resistance etc.) are good. The aluminum base material is effective in making the dice eyes less noticeable, giving the aluminum material a sense of calmness, warmth and the like, and giving it a high-grade feel.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J038 CC031 CC062 CG031 CG071 CG141 CG142 CG161 CG171 CH031 CH041 CH121 CH141 CH151 CJ032 CJ181 CL001 DA162 GA03 GA06 GA07 KA03 MA04 NA01 NA03 PA04 PB05 PC02

Claims (4)

[Claims] 1. An anion electrodeposition coating composition containing a melamine-curable acrylic resin as a curable resin component has an average particle diameter of 0.01 μm to 1 μm and an average inner pore diameter of 0.005 μm to
A colored anion-type electrodeposition paint containing hollow organic polymer particles having a pore diameter / particle diameter ratio of 0.01 to 0.9 μm, and a coating film formed from the paint has a concealing property. An anion-type electrodeposition paint characterized by having: 2. The anionic electrodeposition coating composition according to claim 1, wherein the hollow organic polymer fine particles are an acrylic styrene-based polymer. 3. An anodized aluminum substrate is electrodeposited in the anionic electrodeposition coating, and the resulting electrodeposition is washed with water as required and then baked. Colored aluminum material. 4. An anionic electrodeposition coating composition having a cured film thickness of 20 μm.
The colored aluminum material according to claim 3, wherein the light transmittance (measured wavelength 400 nm) at m is less than 20%.