Nihon Parkerizing Co., Ltd.

Hooker Chemicals & Plastics Corporation

Nobuyuki Oda

Haruyoshi Terada

Yasunobu Matsushima

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.

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Yokohama, Japan

Nobuyuki Oda