Nihon Parkerizing Co., Ltd.

Henkel Corporation

Toyota Motor Corporation

Toshi Miyawaki

Kazuhiko Mori

Hitoshi Ishii

Yoshikazu Saito

Hiroshi Okita

Atsunori Yoshida

Asao Mochizuki

Tsukasa Yamamoto

Shizuo Shima

Yoshiji Shirogane

Hitoshii Ishii

Surface treatment method and composition for zinc coated steel sheet

A treating solution for forming a hydroxide film on each surface of zinc-plated steel plates by cathodic electrolysis is here disclosed which comprises (a) 0.2 to 50 g/l of one or more metal ions selected from the group consisting of Mg.sup.2+, Cr.sup.3+, Ca.sup.2+, Ni.sup.2+, Co.sup.2+ and Al.sup.3+, and (b) 0.1 to 50 g/l of one or more oxidizing agents selected from the group consisting of nitrate ions, nitrite ions, chlorate ions, bromate ions and hydrogen peroxide. A process for the surface treatment of the zinc-plated steel plates by the use of this treating solution is also disclosed.

Surface treating solution and surface treating process for zinc-plated

Zinciferous surfaces, particularly those of galvanized steel, may be effectively coated with an adherent corrosion resistant black layer of fine metal particles by contacting the surfaces with an aqueous solution containing (A) at least 0.5 g/L of the treatment solution of Ni.sup.2+ and/or Co.sup.2+ ions; and (B) an amount, sufficient to complex all the ions of component (A), of a weak complexing component selected from the group consisting of ammonia, saturated aliphatic compounds having at least two amino groups of which at least one is a primary amino group, and/or amino acids; and, optionally but preferably, (C) at least 50 parts per million ('ppm') by weight of a component selected from the group consisting of nitrite ions, nitrate ions, carbonate ions, thiocyanate ions, thiosulfate ions, thiourea, hypophosphite ions, phosphite ions, and/or perchlorate ions.

Process for forming a blackened layer on a zinciferous surface by

The operation of zinc-nickel phosphate conversion coating of active metals is improved by using phosphating solutions containing formic acid or formate ions. Such solutions can work effectively at low temperatures and provide excellent substrates for paint, particularly that applied by electrodeposition.

Zinc-nickel phosphate conversion coating composition and process

Zinc and zinc alloy surfaces can be given an effective corrosion inhibiting treatment by contact for less than a minute with an alkaline aqueous solution having a pH not more than 11 and containing at least 0.020 g/L of dissolved nickel ions and sufficient ammonia to give a molar ratio of ammonia to nickel ion of at least 6. If the concentration of nickel ions in the treating solution is at least 1.0 g/L, a durable blackening of the surface is also produced. Both the corrosion resistance and the quality of the blackening can usually be further improved by subsequent conventional phosphate conversion coating.

Treating zinciferous metal surfaces to blacken them

Disclosed is a Zn-based composite-plated metallic material, comprising a plating layer on a metal substrate. The plating layer consists essentially of (1) Zn or as Zn alloy electroplated onto a metallic substrate and (2) the cathodic precipitation reaction product of aluminum, calcium, magnesium, strontium, titanium, zirconium, molybdenum, and/or tungsten. The latter metal constitutes 0.002 to 10% by weight of the plating layer. The cathodic precipitation-reaction product may be hydroxide, hydroxide hydrate or a phosphate.

Zn-based composite-plated metallic material and plating method

An improved process for preparing a phosphated metal surface for painting comprises electrolyzing the surface as cathode in an aqueous solution containing hexavalent and trivalent chromium in specified concentrations and weight ratios.

Electrolytic post-treatment of phosphated surface

This invention discloses a process for activating steel surface prior to phosphating treatment wherein the steel surface is cleaned, the cleaned steel surface is then treated with an aqueous activating solution containing titanium and pyrophosphate ion, and thereafter the steel surface is treated with a phosphating solution, characterized in that magnesium ion is included in said aqueous activating solution in order to suppress formation of an inactive film on said steel surface due to the presence of said pyrophosphate ion, and then said steel surface is treated with the resulting aqueous activating solution.

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Kanagawa, Japan

Toshi Miyawaki