Treating solution for surface treatment of metal and a method for surface treatment

Abstract

Treating solution for surface treatment of metal to treat one metal material selected from the group consisting of ferriferous material, zinciferous material, aluminiferous material and magnesiferous material or to treat two or more metal materials selected from the group consisting of ferriferous material, zinciferous material, aluminiferous material and magnesiferous material at the same time, wherein the aqueous surface treating solution contains from 5 to 5000 ppm of at least one compound selected from the group consisting of zirconium compound and titanium compound by the metal element, and from 0.1 to 100 ppm of free fluorine ion, further the pH of the treating solution is from 2 to 6. To the treating solution, calcium compound, magnesium compound, strontium compound, nitric acid group, oxygen acid and / or salt of oxygen acid, polymer compound and surface active agent can be added.

Description

TECHNICAL FIELD [0001] The present invention relates to the treating solution for surface treatment of metal which may deposit a surface treated film having excellent corrosion resistance after being coated on the surface of a metal material of a structural construction such as car body consisting of a single material or two to four materials selected from the group consisting of ferriferous material, zinciferous material, aluminiferous material and magnesiferous material independently or simultaneously. BACKGROUND ART [0002] As the method to form on metal surface a surface treated film having excellent corrosion resistance after coated, a zinc phosphate treatment and a chromate treatment are currently used as ordinary methods. According to the zinc phosphate treatment, it is possible to deposit a film having excellent corrosion resistance on the surface of steel such as cold rolled steel plate, zinc plated steel plate and some of aluminum alloys. However, in the zinc phosphate trea...

AI Technical Summary

Benefits of technology

[0008] The object of the present invention is to provide a treating solution for surface treatment of metal to form a surface treated film having excellent corrosion resistance after coated on the surface of ferriferous material, zinciferous material, aluminiferous material and magnesiferous material, which does not contain harmful component to the environment and does not generate sludge to be wasted, which was not accomplished by the prior arts. Further, the object of the present invention is to provide a treating solution for metal surface treatment to form a surface treated film of a uniform component having excellent corrosion resistance after coated on the surface of a metal material composing a structural construction such as car body consisting of two to four materials selecting from the group consisting of ferriferous material, zinciferous material, aluminiferous material and magnesiferous material by same component simultaneously under a uniform condition. And another object of the present invention is to provide a method for treatment using the treating solution.

[0012] And, the present invention is the method for surface treatment of metal comprising, contacting independently each metal material or simultaneously two or more metal materials selected from the group consisting of ferriferous material, zinciferous material, aluminiferous material and magnesiferous material with the treating solution for surface treatment. In the method for surface treatment, after contacting with the treating solution for surface treatment, it is possible to further contact the metal material or the two or more metal materials with acidic aqueous solution of compound containing at least one element selected from the group consisting of cobalt, nickel, tin, copper, titanium and zirconium, with or without washing by water, or it is possible to further contact the metal material or the two or more metal materials with treating solution containing at least one polymer compound selected from water soluble polymer compounds and water dispersible polymer compounds.

Problems solved by technology

However, in the zinc phosphate treatment, the generation of sludge, which is the byproduct of the reaction can not be avoided, and depending on the kind of aluminum alloy, the sufficient corrosion resistance after coated can not be obtained.

However, in the case of the method, the metal material which can be treated is limited to aluminum alloys only, and, it is difficult to be applied to a structural construction having complex structure such as car body, because the surface treated film is formed by coating and drying.

However, in any of these methods, the metal material which can be treated is limited to the aluminum alloy only, originally having excellent corrosion resistance; these methods may not deposit a surface treated film on the surface of ferriferous material or zinciferous material.

However, by this method, it is difficult to form a surface treated film on a surface of ferriferous material such as cold rolled steel, and is not possible to treat ferriferous material at the same time.

However, similarly to the invention disclosed in above mentioned JP 2000-204485 A, since the film is formed by coating and drying, it is difficult to form a uniform film on the surface of a structural construction having complex structure such as car body.

As mentioned above, according to the prior arts, it was impossible to perform surface treatment excellent in corrosion resistance and adhesion on car body and the like composed of two to four metal materials of ferriferous material such as cold rolled steel plate, zinciferous material such as zinc plated steel plate, aluminiferous material and magnesiferous material simultaneously with a treating solution containing no harmful component to the environment and not generating waste sludge.

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