Kansai Paint Company, Ltd.

Nippon Kokan Kabushiki Kaisha

Fuji Sashi Industries, Limited

Norio Nikaido

Mototaka Iihashi

Shinji Shirai

Sueo Umemoto

Masaaki Yamashita

Takahiro Kubota

Takeshi Adaniya

Yoshiaki Miyosawa

Tadashi Nishimoto

Kazuhiko Ozawa

Akira Enatsu

Kisaku Suzuki

This invention relates to a highly corrosion-resistant, multi-layer coated steel sheet, and includes an undercoat film obtained by galvanization or zinc-alloy plating and a chromate coated film thereon, on which a resin-composition film is further applied, comprising an organic high-molecular weight resin having a glass transision temperature of 343.degree. to 423.degree. K. and soluble in organic solvent and hydrophobic silica. For the purpose of improvement of corrosion preventiveness, a sparingly water soluble Cr compound may be contained in this resin composition film. Together with this sparingly water soluble Cr compound, a di- or tri-alkoxysilane compound may be also contained in the resin composition film.

Highly corrosion-resistant, multi-layer coated steel sheets

The present invention relates to a highly corrosion resistant surface-treated steel plate. The steel plate of the invention comprises a zinc deposition or zinc alloy deposition film as the undercoat deposition layer, a chromate film formed on the undercoat deposition layer and a film of a resin composition formed on the chromate film. This resin composition comprises a substrate resin formed by adding at least one basic nitogen atom and at least two primary hydrogen groups to terminal of an epoxy resin, silica and sparingly water soluble Cr compound. The resin composition may comprise a polyisocyanate compound as the curing agent. Moreover, the resin composition may comprise a silane compound as the crosslinking agent for the substrate resin and silica.

Highly corrosion-resistant surface-treated steel plate

The present invention relates to a highly corrosion-resistant surface-treated steel plate. The steel plate of the present invention comprises a zinc deposition or zinc alloy deposition film as the undercoat deposition layer, a chromate film formed on the undercoat deposition layer and a film of a resin composition formed on the chromate film. This resin composition comprises a base resin formed by adding at least one basic nitrogen atom and at least two primary hydroxyl groups to terminals of an epoxy resin. The resin composition may comprise a polyisocyanate compound as the curing agent. Furthermore, the resin composition may comprise silica or a hardly soluble chromium compound as the additive for improving the corrosion resistance. Moreover, the resin composition may comprise a silane compound as the crosslinking agent for the base resin and silica.

A process for treating the surface of aluminum or aluminum alloy comprising the steps of contacting aluminum or aluminum alloy with hot water or steam to form an aluminum oxide layer thereon and conducting electrolysis using the resulting aluminum or aluminum alloy as an anode by applying direct current in an aqueous solution consisting essentially of a water-soluble salt of at least one oxyacid selected from the group consisting of silicic acid, phosphoric acid, molybdic acid, vanadic acid, permanganic acid, stannic acid and tungstic acid.

Process for treating the surface of aluminum or aluminum alloy

In an aqueous coating composition comprising an aqueous medium having dispersed therein an unsaturated polycarboxylic acid resin neutralized with a base and a resol-type phenolic resin, an improvement characterized in that said composition further contains a copper compound dispersed in the aqueous medium in an amount of 0.0005 to 5% by weight in terms of copper metal, based on said polycarboxylic acid resin.

Aqueous coating compositions comprising polycarboxylic acid resin,

In coating aluminum or aluminum alloy by contacting the aluminum or aluminum alloy with hot water or steam to form an aluminum oxide layer on its surface and thereafter electrophoretically coating the aluminum or aluminum alloy with an electrophoretic coating composition to form a resin layer, a process which is characterized in that said electrophoretic coating composition contains at least one water-soluble salt of an oxyacid selected from the group consisting of silicic acid, boric acid, phosphoric acid, vanadic acid, tungstic acid, permanganic acid, molybdic acid and stannic acid.

Process for coating aluminum or aluminum alloy

A process for coating an aluminum or aluminum alloy comprising the steps of subjecting aluminum or aluminum alloy to boehmite treatment or chemical conversion treatment, conducting electrolysis using the resulting aluminum or aluminum alloy as an electrode in an aqueous solution of a water-soluble salt of at least one oxyacid, and thereafter coating electrophoretically the aluminum or aluminum alloy with an aqueous organic coating composition containing a binder resin and a water-soluble salt of at least one oxyacid to form a resin layer, said oxyacid contained in the aqueous solution and aqueous organic coating composition being at least one oxyacid selected from the group consisting of silicic acid, boric acid, phosphoric acid, molybdic acid, vanadic acid, permanganic acid, stannic acid and tungstic acid.

A process for coating an aluminum or aluminum alloy comprising the steps of subjecting the aluminum or aluminum alloy to boehmite treatment or chemical conversion treatment, anodizing the resulting aluminum or aluminum alloy in an aqueous solution of a water-soluble salt of at least one oxyacid, and thereafter coating the aluminum or aluminum alloy with an organic coating composition to form a resin layer, said oxyacid being at least one oxyacid selected from the group consisting of silicic acid, boric acid, phosphoric acid, molybdic acid, vanadic acid, permanganic acid, stannic acid and tungstic acid.

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Hiratsuka, Japan

Norio Nikaido