JPH06166138A - Surface treated aluminum material having good processability without applying oil - Google Patents

Abstract

PURPOSE:To provide an org. coated aluminum material which may be processed without oil coating/degreasing in a press process by extremely enhancing press moldability and corrosion resistance as compared with a conventional aluminum material and capable of being produced in an industrially easy and economical manner. CONSTITUTION:A film of an org. resin mixture prepared by mixing 2-40 pts.wt. of a powder lubricant with 100 pts.wt. of an org. resin is formed on the surface subjected to activation treatment of an aluminum material in a dry thickness of 0.05-5.0mum to obtain a surface treated aluminum material having good processability without applying oil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface-treated aluminum plate which is remarkably improved in the workability of the aluminum plate mainly for press forming, for automobiles, home appliances, building materials, cans and the like.

[0002]

2. Description of the Related Art Aluminum sheets are widely used in the fields of automobiles, home appliances, office automation equipment, building materials, can materials and the like, and are often subjected to various press workings in the manufacturing process of these products.

Lubricant oil is usually applied to the surface of an aluminum plate during press working, but this work has the following problems. (1) Lubricant cannot prevent the occurrence of mold galling during press working. (2) Lubricating oil is often applied by spraying, which causes the lubricating oil to scatter around and deteriorate the working environment. (3) It needs to be degreased and washed in order to be incorporated as a product after press working. However, in this process, there is a risk that the working environment may be reduced or environmental problems may occur (Freon,
1-1-1 trichloroethane etc.) is used.

Therefore, there has been a demand for the development of an aluminum plate which can be press-molded without oiling and which can eliminate the degreasing step. However, the conventional technique of applying a wax, which has been developed as a can material, to the surface (for example, Japanese Patent Laid-Open No. 2-310036). In JP-A-3-180218, if the coating amount of the wax is small, the workability is not sufficient, and if the coating amount is large, the mold is contaminated, and therefore it cannot be used in a wide range of fields, and Al after press working is not used.
Since the metal surface of the plate is exposed, using it as it is may cause a problem in corrosion resistance.

[0005]

It is difficult to obtain a stable effect under various molding conditions by the conventional method for improving the workability by applying these waxes, and the post-processing coating or the like depending on the use environment. Since there is a risk of rusting if the anticorrosion treatment is not applied, it is difficult to omit the washing step after processing or completely omit the press oil.

Therefore, an object of the present invention is to provide a surface-treated aluminum plate capable of ensuring higher workability and maintaining sufficient corrosion resistance in order to overcome these drawbacks of the prior art.

[0007]

DISCLOSURE OF THE INVENTION As a result of intensive studies to overcome these drawbacks of the prior art, the inventors of the present invention have activated the surface of an aluminum plate, and have a resin layer containing a lubricant thereon. It was found that the formation of the above-mentioned structure ensures sufficient workability and can also maintain the corrosion resistance, and the present invention has met the present invention.

That is, according to the first aspect of the present invention,
Organic resin 10 on the surface of the activated aluminum material
An organic resin mixture containing 2 to 40 parts by weight of a powdered lubricant with respect to 0 parts by weight, and a dry film thickness of 0.05 to 5.0 μ.
A surface-treated aluminum material having no oil coating and good workability, which is characterized in that an organic resin mixture film of m is formed.

Here, the activation treatment is a treatment for removing the alumina layer on the surface by an alkali etching treatment, or
It is either a pickling treatment which mainly removes the magnesia layer in an acidic aqueous solution containing a mineral acid, or a treatment which removes most of the oxide layer on the surface by a treatment of carrying out pickling treatment after alkali etching treatment.

The organic resin is preferably one or a mixture of two or more of epoxy resin, alkyd resin, acrylic resin, urethane resin, phenol resin, melamine resin, polyvinyl butyral resin and polyester resin. In addition, it is possible and preferable to add general additives such as a reaction accelerator, a stabilizer and a dispersant to the base resin as long as they do not impair the gist of the present invention.

The powdery lubricant is a polyolefin wax having an average particle size of 0.05 to 20 μm and / or
Alternatively, it is preferably a fluororesin and its average particle size is 1.0 to 10 times the dry film thickness.

[0012]

The present invention will be described in more detail below. The aluminum material in the present invention broadly includes aluminum materials such as aluminum and aluminum alloys, and its form is arbitrary such as plate material, bar material, and pipe material. In the present invention, the above-mentioned aluminum material is subjected to an activation treatment in order to secure the adhesion with the lubricating resin.

As the activation treatment, a treatment for removing the alumina layer on the surface by an alkali etching treatment, a pickling treatment for mainly removing the magnesia layer in an acidic aqueous solution containing a mineral acid, or a treatment for carrying out a pickling treatment after an alkali etching treatment is carried out. Is used to remove most of the oxide layer on the surface.

As the alkali etching treatment and the pickling treatment, a method generally used as a treatment method for an aluminum material may be used, and a commercially available treatment liquid may be used. For example, as the alkali etching treatment, caustic soda, caustic potash, etc., as the pickling treatment, sulfuric acid,
Nitric acid, hydrofluoric acid, a mixed solution of nitric acid and hydrofluoric acid can be used.

In the present invention, the film formed on the surface of the aluminum material after the activation treatment is composed of an organic resin and a powdery lubricant.

As the organic resin, for example, epoxy resin,
Alkyd resin, acrylic resin, urethane resin, phenol resin, melamine resin, polyvinyl butyral resin,
One or a mixture of two or more polyester resins is used.

If the dry film thickness of these organic resin mixtures is too small, the effect of improving the lubricity by the resin is small, and if it is too large, a part of the film peels off during processing and causes deterioration of workability. Within the range of 0.05 to 5.0 μm, the film can be improved in lubricity without peeling off during processing.
A more preferable range is 0.1 to 1.0 μm.

As the powdery lubricant, it is preferable to use a polyolefin wax, a fluororesin or a mixture thereof.

Examples of the polyolefin wax include polyethylene wax, polypropylene wax, polybutene wax and the like.

Examples of the fluorine resin include polytetrafluoroethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin and the like.

The average particle size of these lubricants is 0.05 to 2
It is preferably 0 μm and used in the range of 1.0 to 10 times the dry film thickness.

If the average particle size of the lubricant is smaller than the dry film thickness, the lubricity is insufficient, and conversely, if the average particle size of the lubricant is too large, the lubricant tends to fall off during processing. A more preferable range is 1.5 to 5 times the dry film thickness.

The addition of less than 2 parts by weight of the powdery lubricant to 100 parts by weight of the organic resin is not sufficient for improving the lubricity, and the addition of more than 40 parts by weight reduces the cohesive force of the organic resin. Since there is a risk, it is limited to the range of 2 to 40 parts by weight.

The average particle size of the powdery lubricant is measured by direct observation with a microscope.

[0025]

EXAMPLES The present invention will be specifically described below based on examples.

(Example) Using a 5182 alloy plate having a thickness of 1 mm, which is a typical aluminum alloy for processing used as a material for automobile bodies, first the surface of the aluminum alloy plate was vapor-degreased with trichlorethane, and then shown in Table 1. The activation treatment shown was applied.

Next, an organic resin mixture was prepared in a ratio shown in Table 2 by a ball mill and applied on the surface of the activated sample by a bar coater to form a film having a dry film thickness shown in Table 2. did. Drying was performed by a hot air circulation type drying furnace. In the table, Alsoft and Desmut are manufactured by Okuno Chemical Industries Co., Ltd.

The following organic resins were used as shown in Table 2. Epoxy resin Yuka Shell Epoxy Co., Ltd. Epicoat 1007 Alkyd resin Mitsui Toatsu Kagaku Co., Ltd. Ulix acrylic resin Mitsui Toatsu Kagaku Co., Ltd. Almatex 749-7 Urethane resin Mitsui Toatsu Kagaku Co., Ltd. Orestar phenol resin Dainippon Ink Chemical Industry Co., Ltd. Super Beckasite Melamine Resin Mitsui Toatsu Chemical Co., Ltd. Uban Polyvinyl Butyral Resin Electrochemical Engineering Co., Ltd.
Denka Butyral Polyester Resin Mitsui Toatsu Chemical Co., Ltd. Almatex P645

Further, the epoxy + acrylic resin is 50 parts by weight of the acrylic resin with respect to 100 parts by weight of the epoxy resin, the epoxy + urethane resin is 100 parts by weight of the urethane resin with respect to 100 parts by weight of the epoxy resin, and the acrylic + urethane resin is 100 parts by weight of the acrylic resin. 100 parts by weight of urethane resin was used for each part.

Polyethylene wax was used as the polyolefin wax, and polytetrafluoroethylene resin was used as the fluororesin. In the case of these mixtures, the mixing ratio was 100 parts by weight of the fluorocarbon wax and 100 parts by weight of the fluororesin.

(Workability Test and Evaluation Method) The workability of the aluminum alloy plate is 33 mmφ flat head cylindrical drawing (wrinkle pressing force 1
The limit drawing ratio was evaluated at 000 kg and a processing speed of 100 mm / sec. In addition, the test is a lubricating rust preventive oil
03P) with and without oiling (about 2 g / m ² ) 2
66mmφ blank diameter for resin treated material
Appearance after processing was evaluated with the oil-free material of No. 1 and the film was peeled off or galling occurred over the entire circumference of the side surface of the cylinder.
Those in which these defects were partially generated were evaluated as normal (marked by Δ), and those in which these defects were not generated were evaluated as good (marked by ◯).

(Corrosion resistance test and evaluation method) Corrosion resistance of the samples was determined by cutting a 75 × 150 mm plate from each sample, sealing the end faces, and then performing a salt spray test (5% NaC) for 360 hours.
(1), 35 ° C.), white rust and / or blackening is bad (marked x), and no change is good (○)
Mark).

Table 2 shows examples of the present invention and comparative examples. As is clear from this, any aluminum alloy plate having a surface coating of the present invention has excellent workability and corrosion resistance, and particularly when processed without oiling, it is more excellent in workability than when oiled. Recognize.

On the other hand, it can be seen that the untreated material of Comparative Example 1 is inferior in workability and corrosion resistance, and is particularly inferior in workability in the absence of oil coating. In Comparative Example 2, although the resin film is provided, the film is not activated so that the adhesion of the film is insufficient and sufficient processability and corrosion resistance are not obtained.

In Comparative Examples 3 and 4, sufficient workability and corrosion resistance were not obtained due to insufficient resin thickness. In Comparative Example 5, since the lubricant is excessive, powdering occurs, the appearance after processing is deteriorated, and the corrosion resistance is also deteriorated. In Comparative Example 6, the workability without oiling is insufficient and the appearance is poor because the lubricant is too small.

In Comparative Example 7, the lubricant is too large, so that the appearance and corrosion resistance after processing are not sufficient, and in Comparative Example 8, the workability is not sufficient because it is too small. In Comparative Example 9, the film thickness is too thick and powdering occurs, resulting in insufficient workability.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

[Table 3]

[0040]

[Table 4]

[0041]

[Table 5]

[0042]

[Table 6]

[0043]

As described above, according to the present invention, the surface of an aluminum plate or an aluminum alloy plate is subjected to activation treatment, and an organic resin mixture film containing a powdery lubricant is formed thereon, Press workability and corrosion resistance are significantly improved. In particular, when oil is not applied, there is a remarkable effect that the workability is superior to that when oil is applied.

As a result, the oiling and degreasing steps during various press moldings can be omitted, resulting in cost reduction.
The effect of environmental improvement is improved. It is also mixed with other materials,
Since it retains sufficient workability and corrosion resistance even after the oiling / degreasing process, it does not hinder the use in such a mixed flow process.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masaki Mabuchi, Inventor 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba, Kawasaki Steel Corporation Technical Research Headquarters (72) Inventor Koichi Hashiguchi, Chuo-ku, Chiba-shi, Chiba Kawasaki-cho 1 Technical Research Headquarters, Kawasaki Steel Co., Ltd. (72) Inventor Koji Yamato 1 Kawasaki-cho Chuo-ku, Chiba City, Chiba Prefecture Technical Research Headquarters Kawasaki Steel Co., Ltd. (72) Inventor Motohiro Nambae 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Aluminum Industry Co., Ltd.

Claims (4)

[Claims] 1. A powdered lubricant 2 to 40 per 100 parts by weight of an organic resin on the surface of an activated aluminum material.
A surface-treated aluminum material having no oil coating and good processability, which is formed by forming an organic resin mixture film having a dry film thickness of 0.05 to 5.0 μm with an organic resin mixture containing 1 part by weight. . 2. The activation treatment is a treatment for removing the alumina layer on the surface by an alkali etching treatment, or a pickling treatment for mainly removing the magnesia layer in an acidic aqueous solution containing a mineral acid or a post-alkali etching pickling treatment. The surface-treated aluminum material having no oil coating and good workability according to claim 1, which is a treatment for carrying out. 3. The organic resin is one kind or a mixture of two kinds or more of an epoxy resin, an alkyd resin, an acrylic resin, a urethane resin, a phenol resin, a melamine resin, a polyvinyl butyral resin, and a polyester resin. An oil-free surface-treated aluminum material having good processability according to 1. 4. The powder lubricant has an average particle size of 0.05.
A non-oiled oil according to any one of claims 1 to 3, which is a polyolefin wax and / or a fluororesin having a thickness of -20 µm, and has an average particle size of 1.0 to 10 times the dry film thickness. Surface-treated aluminum material with workability.