Nihon Parkerizing Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Mitsubishi Kasei Corporation

Toyota Motor Corporation

Hiroshi Okita

Akira Nishihara

Takao Ogino

Asao Mochizuki

Tsukasa Yamamoto

Kazuhiko Mori

Koichi Ando

Takumi Honda

Toshi Miyawaki

Ryosuke Sako

Noriaki Yoshitake

Kenshi Saeki

Yukio Tsuge

Akihiko Hasebe

Haruo Iizuka

Kuniaki Tanabe

Yoshiji Shirogane

Yoshinori Sakamoto

Motoki Kanazawa

Ryohsuke Sako

Yoshikazu Shibata

Yasuhiro Okano

Keiji Hadate

Issei Goto

The present invention relates to a process for surface treatment for cathodic electrodeposit coating of a zinc-plated or zinc alloy-plated steel sheet comprising coating and drying a protective coating material on said steel sheet chromate-treated beforehand, to form a protective film before subjecting the sheet to the cathodic electrodeposit coating, which comprises coating a protective coating material having as a principal constituent of film-forming organic component a block isocyanate-containing prepolymer containing in one and the same molecule respectively at least one blocked isocyanate group, hydroxyl group, and tertiary amono group and containing 10-100 parts by weight of silica sol relative to 100 parts by weight of said prepolymer, in an amount of 0.3 g-4 g/m.sup.2, and then heat-drying the same.

Process for treating plated steel sheet

A durable hydrophilic surface can be formed on metals by coating them with a composition containing a first water soluble polymer based on polyacrylamide, a second water soluble polymer with at least 60 mole percent of ionizable groups such as acids and quaternary ammonium salts, and a cross linking agent. Water soluble chromium and zirconium salts that can form complexes with the first water soluble polymer are preferred crosslinking agents. The invention is particularly useful for aluminum to be used in heat exchangers.

Metal surface hydrophilicizing process and composition

A hydrophilic coating is formed on an aluminum surface by the application of an aqueous solution of an amphoteric acrylamide polymer which is dried in place. The polymer solution may contain a cross-linking agent and the dried coating may be subsequently treated to form a water-glass coating.

Method for hydrophilic treatment of aluminum using an amphoteric polymer

This invention relates to an aqueous solution of an alkaline degreasing agent employed for cleaning of metal products surface, and an alkaline degreasing agent employed for making up and replenishing the alkaline degreasing solution. The essential consituent for these alkaline degreasing solution and agent is a compound, such as an alkyl dimethylamine oxide, a nonionic surface active agent, whose structural formula can be described as follows; ##STR1## wherein R is an aliphatic hydrocarbon group having the number of carbon atoms 12-22. The present alkaline degreasing solution can improve degreasing effects without lowering its deforming performance even at a low temperature.

Alkaline degreasing solution comprising amine oxides

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.

Process for activating steel surface prior to phosphating treatment

In the phosphate immersion treatment of a steel sheet structure such as an automobile body, a method is provided wherein the bottom of a treatment tank is flat. An object to be treated such as an automobile body is submerged in the treatment solution. The object to be treated is inclined upward and downward at least once to remove oil, reaction cases, and air collected inside the object. An apparatus for performing phosphate immersion treatment of the object is also provided wherein the treatment solution is sprayed toward the feeding side of the treatment tank to cause small waves, so that formation of a border line mark on the surface of the object due to temporary interruption of the feeding operation may be prevented. An undulation is formed in a conveyor arranged above the treatment tank, or a pair of drop lifters which are individually operable are mounted to the conveyor, so that the object may be inclined upward and downward.

Method and apparatus for treating steel sheet structures

Growing community of inventors

Yokosuka, Japan

Hiroshi Okita