JPH05311454A - Composite coated aluminum plate or aluminum alloy plate excellent in press moldability, scratch resistance, filiform erosion resistance and image clarity - Google Patents

Abstract

PURPOSE:To provide a composite coated aluminum plate or aluminum alloy plate having excellent press moldability, scratch resistance and rust resistance to outside surface and high image clarity when applied to an automobile body. CONSTITUTION:The composite coated aluminum plate or aluminum alloy plate has a chromate layer of 1-50mg/m<2> expressed in terms of metallic chromium as a 1st layer and has an organic coated film containing 30-80wt.% epoxy resin, 5-60wt.% a lubricant and, if necessary, 3-50wt.% rust preventive additive and/or 2-40wt.% electroconductive material as a 2nd layer on the surface of the plate. Fluorocarbon resin, graphite, boron nitride or the like is used as the lubricant comprising the organic resin, each of silica, chromic acid or the like is used as the rust preventive additive, and the maximum effect is attained by compositely adding silica and chromate in a specific compounding ratio.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum plate or an aluminum alloy plate which is used for automobile bodies, home electric appliances and the like, and which is excellent in press formability, scratch resistance, yarn rust resistance and sharpness. ..

[0002]

2. Description of the Related Art Conventionally, steel sheets have been widely used for automobile bodies, but in recent years, in order to protect the global environment, it has been strongly demanded to significantly reduce the weight of automobile bodies for the purpose of improving the fuel efficiency of the automobile. Became. Based on this background,
Aluminum alloy plates for automobile bodies, which replace steel plates, are being actively developed and are already being adopted for some automobiles.

On the other hand, when an aluminum alloy sheet is applied to an automobile body, the press formability, workability (for example, scratch resistance during handling), and quality characteristics after coating (for example, thread rust resistance, etc.) similar to those of a steel sheet are applied. Image clarity and paint adhesion are required, but if the aluminum alloy plate is used as it is, sufficient quality characteristics (for example,
Press moldability, scratch resistance, and yarn rust resistance) cannot be obtained.

Conventionally, as a method for improving the press formability and the thread rust resistance of an aluminum alloy sheet, a method of forming a chromate layer on the surface of aluminum and further forming an organic resin film on the chromate layer (JP-A-3-140480).
No.) Further, although not an aluminum alloy plate, as a method for improving the formability of a steel plate, a method of forming a chromate layer on the surface of the steel plate and forming an organic resin film containing a fluororesin and silica on the upper layer thereof (Patent Document 1) Sho 63
-162886) has been proposed.

[0005]

However, in the method disclosed in Japanese Patent Laid-Open No. 3-140480, although it is possible to improve the thread rust resistance, the press formability is insufficient and the weldability is also poor. Not enough. Further, when the method disclosed in JP-A-63-162886 is applied to an aluminum alloy plate, it is possible to improve press formability, but a carboxylated polyolefin resin is used as a binder for an organic film. Since it is used, the adhesion with the cationic electrodeposition coating applied to the car body is insufficient and the weldability is also insufficient.

The present invention has been made to solve the above problems, and when applied to the body of an automobile,
A composite-coated aluminum plate or aluminum alloy plate that suppresses scratches during handling, has excellent formability in the pressing process, and has excellent outer surface rust resistance and high image clarity on the outer surface of the outer plate. Its purpose is to provide.

[0007]

Means for Solving the Problems The inventors of the present invention have made extensive studies on the coating composition to be applied to an aluminum plate and an aluminum alloy plate in order to achieve such an object, and have obtained the following findings. Improve the press formability by adding a lubricant such as fluororesin, graphite and boron nitride to the organic film to impart lubricity to the surface. The chromate film as the base film suppresses thread rust, and its upper layer The effect becomes more remarkable by adding silica or chromate to the organic film of the. The weldability deteriorates by forming the organic film on the surface of the aluminum alloy plate, but the conductive material is contained in the organic film. Addition of the above improves weldability. High corrosion resistance, epoxy resin is effective for realizing adhesion with cationic electrodeposition coating. The present invention has been made based on such findings. It is characterized in that it is configured as follows.

[1] On the surface of an aluminum plate or an aluminum alloy plate, a chromate layer as a first layer having a metal chromium equivalent of 1 to 150 mg / m ² is provided, and an epoxy resin and a lubricant having the following proportions as a second layer are provided thereon. A composite-coated aluminum plate or aluminum alloy plate which has an organic film having a film thickness of 0.05 to 2 μm containing an agent and is excellent in press moldability, scratch resistance, yarn rust resistance and sharpness. Epoxy resin: 30-80 wt% Lubricant: 5-60 wt% (both are weight ratio of non-volatile content)

[2] On the surface of an aluminum plate or an aluminum alloy plate, a chromate layer as a first layer is 1 to 150 mg / m ^{2 in} terms of metallic chromium, and an epoxy resin in the following proportions as a second layer and a lubricant are provided on the chromate layer as a first layer. Composite-coated aluminum plate or aluminum alloy plate having an organic film having a film thickness of 0.05 to 2 μm containing an agent and an anticorrosive additive and having excellent press moldability, scratch resistance, yarn rust resistance and sharpness .. Epoxy resin: 30 to 80 wt% Lubricant: 5 to 60 wt% Rust preventive additive: 3 to 50 wt% (both are weight ratio of nonvolatile content)

[3] On the surface of an aluminum plate or an aluminum alloy plate, a chromate layer as a first layer is 1 to 150 mg / m ^{2 in} terms of metallic chromium, and as a second layer above it, an epoxy resin in the following ratio, lubrication A composite-coated aluminum plate or aluminum alloy plate excellent in press formability, scratch resistance, yarn rust resistance and sharpness, which has an organic film having a film thickness of 0.05 to 2 μm containing an agent and a conductive substance. Epoxy resin: 30 to 80 wt% Lubricant: 5 to 60 wt% Conductive substance: 2 to 40 wt% (both are nonvolatile component weight ratio)

[4] On the surface of an aluminum plate or an aluminum alloy plate, a chromate layer as a first layer is provided in an amount of 1 to 150 mg / m ^{2 in} terms of metallic chromium, and an epoxy resin in the following proportion as a second layer and a lubricant are provided on the chromate layer as a first layer Coated aluminum plate having excellent press formability, scratch resistance, yarn rust resistance and sharpness, which has an organic film having a film thickness of 0.05 to 2 μm containing an agent, an anticorrosive additive and a conductive substance Or aluminum alloy plate. Epoxy resin: 30 to 80 wt% Lubricant: 5 to 60 wt% Rust preventive additive: 3 to 50 wt% Conductive substance: 2 to 40 wt% (both are weight ratio of nonvolatile content)

[5] In the composite coated aluminum plate or aluminum alloy plate according to the above [1], [2], [3] or [4], the lubricant constituting the organic coating is fluororesin, graphite and A composite-coated aluminum plate or aluminum alloy plate which is excellent in press formability, scratch resistance, thread rust resistance and sharpness and is made of one or more selected from the group consisting of boron nitride.

[6] The above [2], [4] or [5]
In the composite-coated aluminum plate or aluminum alloy plate according to, the rust preventive additive constituting the organic film is one or more selected from the group consisting of silica and chromate, and has press formability, scratch resistance, and resistance to scratches. Composite coated aluminum plate or aluminum alloy plate with excellent thread rust and sharpness.

[7] The above [2], [4] or [5]
In the composite-coated aluminum plate or aluminum alloy plate according to, the rust preventive additive constituting the organic film is composed of silica and chromate in the following proportions, which are press formability, scratch resistance, yarn rust resistance and sharpness. Composite coated aluminum plate or aluminum alloy plate with excellent properties. Silica / chromate = 90/10 to 10/90 (weight ratio)

[8] The above [1], [2], [3],
In the composite-coated aluminum plate or aluminum alloy plate according to [4], [5], [6] or [7], the press-molding property and the resistance to oxidation of the surface of the aluminum plate or the aluminum alloy plate being 100 Å or less. Composite coated aluminum plate or aluminum alloy plate with excellent scratch resistance, yarn rust resistance and sharpness.

[0016]

The original plate used in the present invention is an aluminum plate or an aluminum alloy plate, which is an industrial pure aluminum plate and one of alloy elements such as copper, manganese, silicon, magnesium, zinc, chromium and nickel. Alternatively, there is an aluminum alloy plate containing two or more kinds. The aluminum plate and the aluminum alloy plate are, for example, JIS 1050, 1100, 1085, 1200, 2
002, 2117, 2036, 2037, 2038, 3
004, 5052, 5182, 6009, 6010, 6
There are 015, 6016, 6111 materials and the like. For convenience of description, the pure aluminum plate and the aluminum alloy plate described above are collectively referred to as "aluminum plate" in the description of the "action".

On the surface of the rolled / annealed aluminum plate,
An oxide film with a thickness of several hundred Å is formed, and this oxide film hinders the electrical conductivity when welding aluminum plates,
Since the weldability is significantly deteriorated, it is preferable to dissolve and remove it with an acid or alkaline aqueous solution. If the oxide film thickness is 100 Å or less, good weldability can be secured, and in order to obtain particularly high weldability, it is preferable that the oxide film thickness is 80 Å or less.

The chromate layer formed on the surface of such an aluminum plate has a passivation effect due to hexavalent chromate ions contained in the chromate layer and chromium of trivalent chromium which is a reduction product of chromate ions. Corrosion of the aluminum plate is suppressed by the effect of reducing the anode area by coating the surface with the hydrated oxide film and the effect of the chromium hydrated oxide film of trivalent chromium serving as a diffusion barrier of water and oxygen. The amount of the chromate film deposited is 1 to 150 mg / m ^{2 in} terms of metallic chromium. Adhesion amount is 1 mg /
If it is less than m ² , sufficient yarn rust resistance cannot be expected,
On the other hand, when it exceeds 150 mg / m ² , the weldability deteriorates.
In addition, in order to obtain higher thread rust resistance and weldability,
It is preferably in the range of 5 to 100 mg / m ² .

As the chromate treatment for forming this chromate film, any of reaction type, electrolytic type and coating type methods can be applied. From the viewpoint of yarn rust resistance, a coating type containing a large amount of hexavalent chromate ions in the chromate film is preferable. The coating-type chromate treatment mainly comprises a partially reduced chromic acid aqueous solution, and
A treatment liquid containing one or more of the above components added as required is applied to an aluminum plate and dried without washing with water. Water-soluble or water-dispersible organic resins such as acrylic resins and polyester resins Silica, alumina, titania, zirconia, and other oxide colloids and / or powders Molybdic acid, tungstic acid, vanadic acid, and other acids and / or salts thereof Phosphorus Phosphoric acids such as acids and polyphosphoric acids Zirconium fluorides, silicofluorides, fluorides such as titanium fluorides, metal ions such as zinc ions, iron phosphide, conductive fine powders such as antimony-doped tin oxide, etc. Although the treatment liquid is applied by the roll coater method, it is also possible to adjust the application amount by the air knife method or the roll squeezing method after applying by the dipping method or the spray method.

The organic film formed as the second layer on the chromate layer suppresses the excessive elution of hexavalent chromate ions in the chromate layer into the corrosive environment to maintain the anticorrosive effect and The lubricant added to the coating improves the lubrication characteristics of the aluminum plate during press working. In addition, silica and chromate added to the organic film further improve the thread rust resistance, and the conductive substance imparts appropriate conductivity to the organic film to ensure good weldability. It

As the epoxy resin which is the base resin for the organic film, an epoxy resin obtained by converting bisphenol A, bisphenol F, novolac or the like into a glycidyl ether, or an epoxy resin obtained by adding propylene oxide or ethylene oxide to bisphenol A to form a glycidyl ether is used. be able to. Furthermore, an aliphatic epoxy resin, an alicyclic epoxy resin, and a polyether-based epoxy resin can be used, and two or more kinds of these epoxy resins can be used together. Further, a modified epoxy resin such as a urethane-modified epoxy resin, an amine-modified epoxy resin, an aminosilane-modified epoxy resin, a phosphoric acid-modified epoxy resin, an epoxy ester resin or an acryl-modified epoxy resin, which is obtained by modifying these epoxy resins, can be used.

The urethane-modified epoxy resin is obtained by reacting the above-mentioned epoxy resin with polyisocyanate. As the polyisocyanate, for example, hexamethylene diisocyanate, aliphatic isocyanate such as trimethylhexamethylene diisocyanate, xylylene diisocyanate, 2,4-tolylene diisocyanate,
There are aromatic isocyanates such as 2,6-tolylene diisocyanate, isophorone diisocyanate, alicyclic isocyanates such as norbornane diisocyanate methyl, and mixtures and polynuclear compounds thereof. In addition, a reaction product of these with a polyhydric alcohol such as ethylene glycol, propylene glycol, glycerin, or trimethylolpropane and a high molecular weight polyol such as polypropylene glycol, polytetramethylene glycol, or polytetramethylene glycol is used. There are compounds having two isocyanate groups remaining.

The amine-modified epoxy resin is obtained by reacting the above-mentioned epoxy resin with a polyfunctional amine. Polyfunctional amines include ethanolamine, propanolamine,
Primary alkanolamines such as isopropanolamine and butanolamine, primary alkylamines such as propylamine, butylamine, octylamine and decylamine,
It has two or more active hydrogens in one molecule such as ethylenediamine, aminoethylpiperazine and norbornanediaminomethyl, and one or more of these amines can be used.

The aminosilane-modified epoxy resin is obtained by reacting the above-mentioned epoxy resin with aminosilane. Examples of aminosilanes include γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, and γ-ureidopropyltriethoxysilane, and one or more of these may be used. it can.

The phosphoric acid-modified epoxy resin is obtained by reacting the above-mentioned epoxy resin with phosphoric acid. Phosphoric acid
It has at least one P-OH group in one molecule, and examples thereof include orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, phosphorous acid, and polyphosphoric acid. Further, examples of the phosphoric acid ester include the above-mentioned phosphoric acid alkyl ester and hydroxyalkyl ester.

The epoxy ester resin is obtained by reacting the above-mentioned epoxy resin with a carboxylic acid compound. As the carboxylic acid compound, adipic acid, azelaic acid,
Dicarboxylic acids such as sebacic acid, phthalic acid, dimer acid,
There are fatty acids, alkyd resins, polyester resins and the like.

The acrylic-modified epoxy resin contains a vinyl group copolymerizable with the epoxy resin and acrylic acid, methacrylic acid or their esters, by reacting the above-mentioned epoxy resin with acrylic acid or methacrylic acid. It is obtained by carrying out a graft polymerization with a monomer.

These epoxy resins (including modified epoxy resins) can be used alone or in a mixture of two or more kinds. Further, a curing agent may be used, and as the curing agent, known curing agents such as phenol resin, amino resin, polyamide, amine, blocked isocyanate and acid anhydride can be used. The compounding ratio of the epoxy resin and the curing agent is preferably such that the weight ratio of the curing agent is 50 wt% or less. 5 hardeners
If it exceeds 0 wt%, the coating film becomes hard and the workability is poor.

Next, in the present invention, by adding a lubricant to the organic film, it is possible to prevent the press die and the aluminum plate from adhering to each other and improve the press formability. Here, the amount of the lubricant added to the organic film is 5 to 60 wt%. If it is less than 5 wt%, sufficient press formability cannot be expected, while 60 wt%
If it exceeds, the adhesion with the cationic electrodeposition coating composition deteriorates. Further, in order to satisfy higher press moldability and paint adhesion, a range of 10 to 50 wt% is preferable.

When the lubricant is in the form of particles, its average particle size is preferably in the range of 0.1 to 9 μm. It is considered that the lubricant added to the organic film reduces the friction coefficient of the surface by appropriately exposing it to the surface of the organic film and imparts lubricity. However, the press formability is deteriorated. On the other hand, when it exceeds 9 μm, the smoothness of the electrodeposition coated surface is deteriorated and the image clarity is deteriorated.

As the lubricant used in the present invention, a fluororesin (eg, tetrafluoroethylene resin, tetrafluoroethylene-hexafluoropropylene copolymer resin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin, Fine powder of tetrafluoroethylene-ethylene copolymer resin, trifluoroethylene chloride resin, vinylidene fluoride resin), graphite, boron nitride, polyethylene resin, molybdenum disulfide, oil-based lubricant, carbon fluoride, extreme pressure agent, etc. , Liquids, colloids can be used. From the viewpoint of press moldability, fluororesin, graphite, and boron nitride are excellent, and tetrafluoroethylene resin is most preferable among fluororesins.

Next, in the present invention, for the purpose of improving the thread rust resistance, 3 to 50 wt% of a rust preventive additive is added to the organic film.
Can be added within the range. This rust preventive additive is 3w
If it is less than t%, the effect of improving the yarn rust resistance is insufficient, while if it exceeds 50 wt%, the film peels off during press molding and the formability deteriorates. Further, in order to satisfy the higher level of yarn rust resistance and moldability, the range of 5 to 40 wt% is preferable.

As the rust preventive additive used in the present invention, fine powders or colloids of silica, chromate, aluminum dihydrogen tripolyphosphate, aluminum phosphomolybdate, zinc phosphate and the like can be used. From the viewpoint of yarn rust resistance, silica and chromate are preferable. It is presumed that a small amount of silica is dissolved in a corrosive environment, and the silicate ion functions as a film-forming corrosion inhibitor to exert an anticorrosion effect. Further, it is considered that the chromate dissolves in a corrosive environment in a trace amount to release hexavalent chromate ions and suppress the corrosion of the aluminum plate by a mechanism similar to that of the chromate layer.

By adding silica and chromate in combination, it is possible to obtain a higher level of yarn rust resistance. That is, by adding silica and chromate in the organic coating in a weight ratio of silica / chromate within the range of 90/10 to 10/90, the most excellent yarn resistance due to the synergistic effect of both anticorrosion effects. Rust resistance is obtained. If the silica / chromate ratio exceeds 90/10 or less than 10/90, the synergistic effect becomes insufficient and the yarn rust resistance is slightly inferior.

The silica used in the present invention is dry silica (for example, AEROSIL 13 manufactured by Nippon Aerosil Co., Ltd.).
0, AEROSIL 200, AEROSIL 300, AEROSIL 38
0, AEROSIL R972, AEROSIL R811, AEROSIL R
805), organosilica sol (for example, MA-ST, IPA-ST, NBA-ST manufactured by Nissan Chemical Industries, Ltd.).
IBA-ST, EG-ST, XBA-ST, ETC-S
T, DMAC-ST, etc.), precipitated wet silica (eg,
Tokuyama Soda Co., Ltd. T-32 (S), K-41, F-80
Etc.), gel wet silica (eg, Fuji Davison Chemical)
Syloid 244, Syloid 150, Syloid 72, Syloid 65, SHIELDEX, etc., manufactured by Co., Ltd.) can be applied. It is also possible to use a mixture of two or more of the above silicas.

When hydrophobic silica whose surface is hydrophobized by substituting a silanol group on the silica surface with a methyl group or the like is added to the epoxy resin, the organic film and the cationic electrodeposition paint which is a water-based paint are compatible with each other. Is poor, and a smooth electrodeposited surface cannot be obtained, resulting in poor image clarity after middle / top coating. Therefore, in order to obtain excellent image clarity, silica having a non-hydrophobic surface is preferable. Further, in the present invention, as a method for further improving the anticorrosion effect of silica, silica ion-exchanged with a cation having a corrosion-inhibiting action (for example, calcium, zinc, cobalt, lead, strontium, lithium, barium, manganese) is used. Can be used. These cations exchange ions with protons in corrosive environments,
It is considered that the release from silica forms a stable corrosion product on the metal surface and suppresses corrosion.

The specific surface area of silica is 20 to 100.
The range of 0 m ² / g (BET method) is preferable. When the specific surface area is less than 20 m ² / g, the effect of improving the thread rust resistance is poor, and the smoothness of the electrodeposition coated surface is reduced and the image clarity is deteriorated. On the other hand, when the specific surface area exceeds 1000 m ² / g, the thixotropy of the coating composition containing silica becomes strong, and the workability at the time of coating with a roll coater or the like decreases.

Chromates used in the present invention include barium chromate (BaCrO ₄ ), strontium chromate (SrCrO ₄ ), and calcium chromate (CaCr).
O ₄ ), zinc chromate (ZnCrO ₄ .4Zn (O
H) ₂ ), zinc potassium chromate (K ₂ O ・ 4ZnO ・ 4
CrO ₃ .3H ₂ O), lead chromate (PbCrO ₄ ) and the like can be used. It is also possible to use a mixture of two or more of the above chromates. However, from the viewpoint of yarn rust resistance, barium chromate and strontium chromate, which are expected to have a self-repairing effect due to hexavalent chromate ions over a long period of time, are preferable. In addition, barium chromate, which has a low solubility in water, is preferable from the viewpoint of minimizing the elution of water-soluble chromium from the chromate added to the organic film in the pretreatment process for coating automobiles. As the average particle size of chromate,
The range of 0.1 to 1 μm is preferable, and if it is less than 0.1 μm, the solubility of chromate in water becomes excessive, so that the self-repairing effect of hexavalent chromate ion is lost, while it exceeds 1 μm. And the smoothness of the electrodeposition coated surface deteriorates and the image clarity deteriorates.

Next, in the present invention, by adding a conductive substance to the organic coating, the organic coating is provided with appropriate conductivity and the weldability can be improved. here,
The amount of conductive material added to the organic film is 2 to 40 wt%. If it is less than 2 wt%, the conductivity of the organic film is insufficient, so the weldability is somewhat poor, while if it exceeds 40 wt%, the conductive substance in the organic film becomes the starting point of the oxygen reduction reaction in a corrosive environment, and the thread rust resistance Deteriorate. Moreover, in order to satisfy further high weldability and yarn rust resistance, 3 to 3 is required.
The range of 0 wt% is preferable. The average particle diameter of the conductive material is preferably in the range of 0.01 to 9 μm,
If it is less than μm, it becomes difficult to three-dimensionally contact the particles of the conductive substance, and sufficient conductivity cannot be exhibited.
On the other hand, when it exceeds 9 μm, the smoothness of the electrodeposition coated surface decreases,
The image clarity deteriorates.

As the conductive substance, iron phosphide, graphite, antimony-doped tin oxide, antimony-doped indium oxide, antimony-doped tin oxide-coated titanium oxide, carbon black, titanium black, metal powder and the like can be used. it can. In addition, the above conductive material
It is also possible to use a mixture of two or more species. Iron phosphide is preferable from the viewpoint of the influence on the thread rust resistance and the conductivity.

In the present invention, the lubricant, the rust preventive additive such as silica and chromate, and the conductive substance described above are the main additive components in the epoxy resin. It is also possible to mix one or more of coloring pigments (for example, condensed polycyclic organic pigments, phthalocyanine organic pigments, etc.), coloring dyes (for example, azo dyes, azo metal complex salt dyes, etc.), and surfactants. It is possible.

The organic film of the present invention described above has a thickness of 0.05 to 2 μm. If the film thickness is less than 0.05 μm, sufficient thread rust resistance, lubricity, and scratch resistance cannot be expected, while if it exceeds 2 μm, weldability and sharpness deteriorate. Further, in order to satisfy higher thread rust resistance, lubricity, scratch resistance, weldability, and sharpness,
The range of 1.5 μm is preferable.

The method for applying the coating composition to an aluminum plate to obtain the above-mentioned organic film of the present invention is usually by a roll coater method, but after applying by a dipping method or a spray method, an air knife method or a roll drawing method is used. It is also possible to adjust the coating amount. The heat treatment after applying the coating composition can be performed in a hot air oven, a high frequency induction heating oven, an infrared oven or the like. The heat treatment is the ultimate plate temperature of 50 to 3
It is carried out at a temperature of 00 ° C, preferably 60 to 250 ° C.
Furthermore, when the present invention is applied to an aluminum plate having a BH property, heat treatment at 170 ° C. or lower is preferable.

The aluminum plate of the present invention usually has a chromate film + organic film on both sides of the aluminum plate. However, in some cases, the chromate film + organic film is applied only on one side, and on the other side, for example, an oxide film is used. The aluminum plate as it is As it is the aluminum plate from which the oxide film has been removed It is possible to adopt any mode such as only the chromate film.

[0045]

EXAMPLES Examples of the present invention will be shown below together with comparative examples. Aluminum alloy plate 50g / before chromate treatment
1, soak in 50 ° C sodium hydroxide aqueous solution for 2 minutes,
After washing with water, neutralization with nitric acid, washing with water, and drying, the oxide film was removed. After removing this oxide film, chromate treatment is applied,
Then, the coating composition was applied with a roll coater and baked. Also, for some aluminum alloy sheets, spray degreasing with 20 g / l, 60 ° C. sodium orthosilicate aqueous solution for 20 seconds, washing with water, drying and chromate treatment, then coating composition with a roll coater and baking. It was

With respect to the composite-coated aluminum alloy sheet thus obtained, rust resistance to thread, image clarity, paint adhesion,
Each evaluation test of scratch resistance was performed. The processing conditions of this example are as follows. Aluminum alloy plate JIS 5052 equivalent thickness 1.0 mm, surface roughness (Ra) 1.
A 0 μm aluminum alloy plate was used as a processed original plate.

Chromate treatment a. Coating Chromate Treatment A chromate treatment liquid having the following liquid composition was applied by a roll coater and dried without washing with water. The amount of the chromate film deposited was adjusted by changing the peripheral speed ratio of the pickup roll of the roll coater and the applicator roll. Chromic anhydride: 20 g / l Phosphate ion: 4 g / l Zirconium fluoride ion: 1 g / l Zinc ion: 1 g / l Hexavalent chromium / Trivalent chromium: 3/3 (weight ratio) Chromic anhydride / zirconium fluoride Ion: 20/1
(Weight ratio) b. Electrolytic chromate treatment Chromic anhydride 30 g / l, sulfuric acid 0.2 g / l, bath temperature 40 ° C
An aluminum alloy plate was subjected to cathodic electrolysis treatment at a current density of 10 A / dm ² using the treatment liquid of Example ¹ , washed with water and dried.
The amount of the chromate film deposited was adjusted by controlling the amount of electricity applied during the cathodic electrolysis treatment.

Organic Resins Table 1 shows the resins used in this example. Resin A in the table
E was prepared by the method shown below. A: Epicoat 1009 (bisphenol A type epoxy resin, manufactured by Yuka Shell Epoxy Co., Ltd.) was dissolved in methyl ethyl ketone to obtain a resin solution having a resin content of 20%. B: Epokey 803 as urethane-modified epoxy resin
(Mitsui Toatsu Chemical Co., Ltd.) was used. C: 500 parts of a bisphenol A type epoxy resin having an epoxy equivalent of 1500, 390 parts of xylene, and 390 parts of cyclohexanone were added to 20 parts of isopropanolamine, and the mixture was reacted at 100 ° C. for 5 hours to give a resin content of 40%. An amine-modified epoxy resin was obtained. D: Polyethylene glycol 440 having a molecular weight of 1000
The mixture was heated to 60 ° C., and 153 parts of 2,6-tolylene diisocyanate was added. The NCO% of this intermediate was 4.8%. Further, 106 parts of ε-caprolactam was added to continue the reaction, and after confirming that NCO% was 0, 175 parts of butanol was added to obtain a blocked isocyanate as a curing agent having a resin content of 70%. E: Uban 20SE-6 which is a butylated melamine resin
0 (manufactured by Mitsui Toatsu Chemicals, Inc.) was used as an amino resin as a curing agent.

Lubricants Table 2 shows the lubricants used in this example.

Antirust Additives Table 3 shows the antirust additives used in this example.

Conductive Substances Table 4 shows the conductive substances used in this example.

Tables 5 to 14 show the constitutions of the composite coated aluminum alloy sheets prepared in this example and the evaluation results of their corrosion resistance (thread rust resistance), image clarity, paint adhesion, weldability and scratch resistance. Shown in. The evaluation method of each characteristic is as follows.

A) Corrosion resistance (thread rust resistance) The test material was PBL-3020 manufactured by Nippon Parkerizing Co., Ltd.
Treated with zinc phosphate and then U- manufactured by Nippon Paint Co., Ltd.
After electrodeposition coating (25μ) at 600, Kansai Paint
KPX-36 manufactured by K.K. Co., Ltd. was used for intermediate coating (30 .mu.m), and overcoating (35 .mu.m) was applied with LugaBake B-531 manufactured by Kansai Paint K.K. Cross-cut these test pieces with a cutter knife, [salt spray test, 24 hours →
Wet test (40 ° C., relative humidity 85%) for 720 hours] was performed to evaluate the corrosion resistance (yarn rust resistance) by the swelling width of corrosion from the black cut portion. The evaluation criteria are as follows. ◎: Less than 1 mm ○: 1 mm or more and less than 2 mm △: 2 mm or more and less than 4 mm ×: 4 mm or more

B) Image clarity: The sample material was subjected to the same electrodeposition coating, intermediate coating and top coating as in the above a), and the image clarity measuring device (IC) manufactured by Suga Test Instruments Co., Ltd.
M-2DP) and the image clarity C when a slit of 0.5 mm was used. The evaluation criteria are as follows. ◎: 80 or more ○: less than 80, 75 or more △: less than 75, 70 or more ×: less than 70

C) Paint Adhesion The test material was subjected to the same electrodeposition coating, intermediate coating and top coating as in the above a), and these test pieces were immersed in ion exchanged water at 40 ° C. for 240 hours. Then take out the test piece,
After leaving it at room temperature for 24 hours, 100 cross-cuts were cut on the coating film at intervals of 2 mm, cellophane tape was adhered and peeled off, and the residual rate of the coating film was evaluated. The evaluation criteria are as follows. ◎: No peeling ○: Peeling less than 3% △: Peeling 3% or more, less than 10% ×: Peeling 10% or more

D) Weldability DR type electrode (tip diameter 6 mm), pressure: 270 kg
f, energization time: 5 cycles / 50 Hz, welding current: 25
A continuous dot test is performed at kA, and JIS is specified every 100 dots.
The tensile shear load is measured based on Z 3136 and JIS Z
The number of RBIs was evaluated based on 3140. The evaluation criteria are as follows. ◎: 1200 points or more ○: 800 points or more and less than 1200 points Δ: 500 points or more and less than 800 points ×: less than 500 points

E) Scratch resistance Using a weighted scratching strength tester, the test material was subjected to a scratching test with a sapphire needle (0.05 mmφ) under a constant load and evaluated by the load at which scratches began to be observed. .. The evaluation criteria are as follows. A: 50 g or more O: 40 g or more and less than 50 g B: 30 g or more, less than 40 g X: less than 30 g

F) Press formability punch: 50 mmφ · R
8, die: 53mmφ ・ R5, blank diameter: 110m
The press formability was evaluated by performing deep drawing at mφ and BHF of 3.6 ton and measuring the forming height until cracking. The evaluation criteria are as follows. A: 15 mm or more O: 14 mm or more and less than 15 mm B: 13 mm or more and less than 14 mm X: less than 13 mm

In Tables 5 to 14, No. 1-No. 8 is
The effect of chromate treatment was investigated. No. 1 and No. 9-No. In 18, the effect of the resin blended in the organic film was examined. No. 1 and No. 19-N
o. In No. 31, the influence of the lubricant compounded in the organic film was examined. No. 1 and No. 32-No. 49,
No. In No. 65, the effect of the rust preventive additive incorporated in the organic film was examined. No. 1 and No. 50-No.
58, No. In No. 65, the influence of the conductive substance contained in the organic film was examined. No. 59-No. 64, the effect of the film thickness of the organic film was examined. No. 67
Then, the influence of the oxide film on the surface of the aluminum alloy plate was investigated.

[0060]

[Table 1]

[0061]

[Table 2]

[0062]

[Table 3]

[0063]

[Table 4]

[0064]

[Table 5]

[0065]

[Table 6]

[0066]

[Table 7]

[0067]

[Table 8]

[0068]

[Table 9]

[0069]

[Table 10]

[0070]

[Table 11]

[0071]

[Table 12]

[0072]

[Table 13]

[0073]

[Table 14]

* 1 From: Example of the present invention Ratio: Comparative example * 2 Chromate adhesion amount in terms of metal chromium * 3 See Table 1 * 4 Nonvolatile content by weight * 5 See Table 2 * 6 See Table 3 * 7 Nonvolatile content Weight ratio * 8 See Table 4 * 9 Aluminum alloy plate with oxide film removed * 10 Aluminum alloy plate is spray degreased with sodium orthosilicate, washed with water, dried and chromated,
Then, the coating composition is applied by a roll coater and baked.

[0075]

As described above, according to the present invention, excellent press formability is ensured while ensuring good image clarity,
Moreover, since it has excellent thread rust resistance, scratch resistance, paint adhesion, and spot welding is possible, it is extremely useful as an aluminum plate or aluminum alloy plate for automobiles and home appliances. Further, since the composite-coated aluminum plate or aluminum alloy plate of the present invention suppresses the elution of aluminum into the treatment liquid during the phosphating treatment, it is treated at the same time as the steel sheet in the existing automobile phosphating process. However, the eluted aluminum does not hinder the formation of the phosphate coating on the steel sheet. Further, the aluminum plate and aluminum alloy plate of the present invention can obtain excellent thread rust resistance and paint adhesion even if the phosphate treatment step is omitted.

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[Procedure amendment]

[Submission date] April 9, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0019

[Correction method] Change

[Correction content]

As the chromate treatment for forming this chromate film, any of reaction type, electrolytic type and coating type methods can be applied. From the viewpoint of yarn rust resistance, a coating type containing a large amount of hexavalent chromate ions in the chromate film is preferable. The coating-type chromate treatment mainly comprises a partially reduced chromic acid aqueous solution, and
A treatment liquid containing one or more of the above components added as required is applied to an aluminum plate and dried without washing with water. Water-soluble or water-dispersible organic resin such as acrylic resin and polyester resin Silica, alumina, titania, zirconia, and other oxide colloids and / or powders Molybdic acid, tungstic acid, vanadic acid, and other acids and / or salts thereof Phosphorus acid, phosphoric acids zirconium fluoride and poly phosphoric acid, silicofluoride, a metal ion iron phosphide, such as fluoride, zinc ions, such as titanium fluoride, conductive fine powder coating type chromate treatment, such as antimony-doped tin oxide, usually Although the treatment liquid is applied by the roll coater method, it is also possible to adjust the application amount by the air knife method or the roll squeezing method after applying by the dipping method or the spray method.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction content]

The aminosilane-modified epoxy resin is obtained by reacting the above-mentioned epoxy resin with aminosilane. The aminosilane, .gamma.-aminopropyltriethoxysilane, n-beta (aminoethyl) .gamma.-aminopropyl trimethinecyanine Tokishishiran, there is .gamma. ureidopropyltriethoxysilane, etc., it is used alone or in combination of two or more of these it can.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

The acryl-modified epoxy resin is obtained by reacting the above-mentioned epoxy resin with acrylic acid or methacrylic acid, or with an epoxy resin and acrylic acid, methacrylic acid or their esters, and vinyl groups copolymerizable therewith. It is obtained by graft-polymerizing the contained monomer.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0033

[Correction method] Change

[Correction content]

[0033] As anti-rust additives for use in the present invention can be silica, chromate, tripolyphosphate dihydrogen aluminum, aluminum phosphomolybdate, the use of powder or colloid of zinc phosphate and the like. From the viewpoint of yarn rust resistance, silica and chromate are preferable. It is presumed that a small amount of silica is dissolved in a corrosive environment, and the silicate ion functions as a film-forming corrosion inhibitor to exert an anticorrosion effect. Further, it is considered that the chromate dissolves in a corrosive environment in a trace amount to release hexavalent chromate ions and suppress the corrosion of the aluminum plate by a mechanism similar to that of the chromate layer.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0044

[Correction method] Change

[Correction content]

The aluminum plate of the present invention usually has a chromate film + organic film on both sides of the aluminum plate. However, in some cases, the chromate film + organic film is applied only on one side, and on the other side, for example, an oxide film is used. can be any aspect of the chromate film only like remains of the aluminum plate remained oxide film aluminum plate to remove the with.

[Procedure Amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0047

[Correction method] Change

[Correction content]

Chromate treatment a. Coating Chromate Treatment A chromate treatment liquid having the following liquid composition was applied by a roll coater and dried without washing with water. The amount of the chromate film deposited was adjusted by changing the peripheral speed ratio of the pickup roll of the roll coater and the applicator roll. Chromic anhydride: 20 g / l Phosphate ion: 4 g / l Zirconium fluoride ion: 1 g / l Zinc ion: 1 g / l Hexavalent chromium / Trivalent chromium: 3/3 (weight ratio) Chromic anhydride / zirconium fluoride Ion: 20/1
(Weight ratio) b. Electrolytic chromate treatment Chromic anhydride 30 g / l, sulfuric acid 0.2 g / l, bath temperature 40 ° C
An aluminum alloy plate was subjected to cathodic electrolysis treatment at a current density of 10 A / dm ² using the treatment liquid of Example ¹ , washed with water and dried.
The amount of the chromate film deposited was adjusted by controlling the amount of electricity applied during the cathodic electrolysis treatment.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0056

[Correction method] Change

[Correction content]

D) Weldability DR type electrode (tip diameter 6 mm) , pressing force: 270 kgf,
Energization time: 5 cycles / 50 Hz, welding current: 25 kA
The continuous dotability test was conducted with JIS Z 31
The tensile shear load is measured based on 36 and JIS Z 3140
The number of RBIs was evaluated based on. The evaluation criteria are as follows. ◎: 1200 points or more ○: 800 points or more and less than 1200 points Δ: 500 points or more and less than 800 points ×: less than 500 points

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0075

[Correction method] Change

[Correction content]

[0075]

As described above, according to the present invention, excellent press formability is ensured while ensuring good image clarity,
Moreover, since it has excellent thread rust resistance, scratch resistance, paint adhesion, and spot welding is possible, it is extremely useful as an aluminum plate or aluminum alloy plate for automobiles and home appliances. The composite-coated aluminum plate or aluminum alloy plate of the invention, since the elution of aluminum into phosphating time in the treatment solution can be suppressed, at the same time processing the steel sheet by existing automotive phosphating process carried out even, never forming a phosphate film on the steel sheet is inhibited by the eluted aluminum. Further, the aluminum plate of the present invention, an aluminum alloy sheet excellent filiform rust resistance be omitted phosphating step, the paint adhesion is obtained.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location B32B 15/08 P C25D 11/38 C (72) Inventor Masaaki Yamashita 1-chome, Marunouchi, Chiyoda-ku, Tokyo No. 2 Nihon Steel Pipe Co., Ltd. (72) Inventor Toyofumi Watanabe 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd. (72) Inventor Yoshio Kikuta 1900, Togo, Mobara-shi, Chiba Mitsui Toatsu (72) Inventor Kimio Kobori 1900, Togo, Mobara-shi, Chiba Prefecture Mitsui Toatsu Chemical Co., Ltd. (72) Inventor, Takashi Yokoyama 1900, Togo, Mobara-shi, Chiba Prefecture Mitsui Toatsu Chemical Co., Ltd.

Claims (8)

[Claims] 1. A surface of an aluminum plate or an aluminum alloy plate has a chromate layer as a first layer of 1 to 150 mg / m ^{2 in} terms of metallic chromium, and an epoxy resin and a lubricant in the following proportions as a second layer above the chromate layer. A composite-coated aluminum plate or aluminum alloy plate excellent in press formability, scratch resistance, yarn rust resistance and sharpness, which has an organic film having a film thickness of 0.05 to 2 μm containing Epoxy resin: 30-80 wt% Lubricant: 5-60 wt% (both are weight ratio of non-volatile content) 2. A surface of an aluminum plate or an aluminum alloy plate has a chromate layer as a first layer of 1 to 150 mg / m ^{2 in} terms of metallic chromium, and an epoxy resin and a lubricant having the following proportions as a second layer above the chromate layer. And a composite-coated aluminum plate or aluminum alloy plate which has an organic film having a film thickness of 0.05 to 2 μm containing a rust preventive additive and which is excellent in press formability, scratch resistance, yarn rust resistance and sharpness. Epoxy resin: 30 to 80 wt% Lubricant: 5 to 60 wt% Rust preventive additive: 3 to 50 wt% (both are weight ratio of nonvolatile content) 3. A surface of an aluminum plate or an aluminum alloy plate has a chromate layer as a first layer of 1 to 150 mg / m ^{2 in} terms of metallic chromium, and an epoxy resin and a lubricant having the following proportions as a second layer above the chromate layer. And a composite-coated aluminum plate or aluminum alloy plate excellent in press formability, scratch resistance, yarn rust resistance and sharpness, which has an organic film having a film thickness of 0.05 to 2 μm containing a conductive substance. Epoxy resin: 30 to 80 wt% Lubricant: 5 to 60 wt% Conductive substance: 2 to 40 wt% (both are nonvolatile component weight ratio) 4. An aluminum plate or an aluminum alloy plate surface has a chromate layer as a first layer in the range of 1 to 150 mg / m ^{2 in} terms of metallic chromium, and an epoxy resin and a lubricant having the following proportions as a second layer above the chromate layer. , A composite-coated aluminum plate having an excellent press formability, scratch resistance, yarn rust resistance and sharpness, which has an organic film having a film thickness of 0.05 to 2 μm containing a rust preventive additive and a conductive substance, or Aluminum alloy plate. Epoxy resin: 30 to 80 wt% Lubricant: 5 to 60 wt% Rust preventive additive: 3 to 50 wt% Conductive substance: 2 to 40 wt% (both are weight ratio of nonvolatile content) 5. The press formability and scratch resistance according to claim 1, 2, 3 or 4, wherein the lubricant constituting the organic film is at least one selected from the group consisting of fluororesin, graphite and boron nitride. Composite coated aluminum plate or aluminum alloy plate with excellent durability, rust resistance and sharpness. 6. The press moldability, scratch resistance, and scratch resistance according to claim 2, 4 or 5, wherein the rust-preventive additive constituting the organic film comprises at least one selected from the group consisting of silica and chromate. Composite coated aluminum plate or aluminum alloy plate with excellent rust resistance and sharpness. 7. The press formability, scratch resistance, yarn rust resistance and freshness according to claim 2, 4 or 5, wherein the rust preventive additive constituting the organic film comprises silica and chromate in the following proportions. Composite coated aluminum plate or aluminum alloy plate with excellent image clarity. Silica / chromate = 90/10 to 10/90 (weight ratio) 8. The oxide film thickness of the surface of the aluminum plate or aluminum alloy plate is 100 Å or less,
A composite-coated aluminum plate or aluminum alloy plate excellent in press formability, scratch resistance, yarn rust resistance and sharpness as described in 3, 4, 5, 6 or 7.