Nihon Parkerizing Co., Ltd.

Nippon Steel Corporation

Hooker Chemicals & Plastics Corporation

Haruyoshi Terada

Nobuyuki Oda

Akimitsu Fukuda

Youji Ono

Hideaki Kaneko

Seijun Higuchi

Yasunobu Matsushima

Kenichi Asakawa

Akinori Maruta

Yohji Oho

Yokichi Satoh

The present invention offers a cleaning agent for aluminium surface which is an aqueous acidic liquid containing peroxo acid and/or peroxide in 0.05-10 g/l and further one or more kinds out of sulphuric acid, phosphoric acid and nitric acid.

Cleaning chemical for aluminium surface

A chromate treatment of metal coated steel sheets comprising subjecting the sheets to a cathodic electrolytic treatment to form a chromate film thereon and subjecting the sheet to an anodic electrolytic treatment to form an anodic electrolytic film on the chromate film and to convert the chromate film. The treatment is applicable to various metal coated steel sheets, such as those coated with zinc, zinc alloy, aluminum, aluminum alloy, lead and lead alloy, and is effective to improve the corrosion resistance of the sheets, the quality of paint coating applied on the sheets and the adaptability of the sheets to a cation electro-deposition paint coating.

Chromate treatment of a metal coated steel sheet

A method of treating a zinc plated steel surface provides improved corrosion resistance and painting properties. The surface is rendered cathodic in the presence of an aqueous treatment liquor containing 5-70 g/l of hexavalent chromium, 0.01 to 5 g/l of trivalent chromium, 5-100 g/l of silica and/or silicate and 0.05-10 g/l of nitrate in which the ratio of Cr.sup.3+ /Cr.sup.6+ is within the range 1/50-1/3.

Treatment of galvanized steel

An aqueous chromium-free composition is useful for imparting a corrosion resistance paintable coating to a tin surface. The composition contains a titanium or zirconium compound, a pyrazole derivative, a myoinositol phosphate ester and a silicon compound. The surface is either chemically coated via contact with the composition or electrolytically coated via immersion in the composition.

Method of surface treatment of tin plated cans and tin plated steel

A conversion coating solution for treating metallic surfaces has a pH value in the range of 3 to 6 and contains 1 g/l to 50 g/l of an acid alkali phosphate as phosphate ions, 0.2 g/l to 20 g/l of one or more of chlorates and bromates, and 0.01 g/l to 0.5 g/l of tin ions, with a weight ratio of chlorine ions to tin ions being between 0.6 and 6. The solution provides a continuous and uniform conversion coating having high anti-corrosion performance.

Conversion coating solutions for treating metallic surfaces

A conversion coating solution for treating metallic surfaces is able to form conversion coating films having excellent anticorrosiveness and giving good adhesiveness and gloss to the overcoating. The conversion coating solution has a pH value of 5.5 to 6.5 and contains 0.1 to 50 g/liter as phosphate ion of acid salts of alkali phosphates, 0.01 to 0.5 g/liter of stannous ion and 2 to 12-fold by weight as much fluorine ion as the stannous ion. The conversion coating solution may be further combined with 0.2 to 5 g/liter of at least one of pyrazole compounds, hydroxylamine compounds and hydrazine compounds.

Growing community of inventors

Tanashi, Japan

Haruyoshi Terada