Toyota Jidosha Kabushiki Kaisha

Aisin Seiki Kabushiki Kaisha

C.uyemura Co., Ltd.

Yoshio Takagi

Taketoshi Minohara

Junichi Handa

Hiroshi Ito

Shinji Kato

Hitoshi Ozawa

Hiroki Uchida

Keiichi Kano

Hiroshi Itou

Hideo Yano

Tsuyoshi Uotani

Tadashi Isobe

Yosiomi Aoyagi

Keita Suzuki

A production process of pigment according to this invention comprises the steps of: a first step of forming an inorganic compound coating layer on the entire surfaces of scaly substrates made of ceramic; a second step of forming metallic glossy dots on the surfaces of the inorganic compound coating layer in a scattered manner by an electroless plating, and the metallic glossy dots occupying from 0.05 to 95% of the surfaces of the inorganic compound coating layer with respect to the total surface area of the inorganic compound coating layer; and a third step of irradiating ultraviolet ray on particles formed by the second step. The impurities and the like, which adversely affect the color hue of the pigment, have been discolored or faded away by the ultraviolet ray irradiation in the third step. Accordingly, the pigment having good weather resistance can be produced readily and stably by the present invention.

Production process of pigment

A pigment comprises a substrate, a metallic layer formed on at least one surface of the substrate and imparting metallic luster, and a transparent inorganic compound layer formed on surfaces of the substrate and the metallic layer. Thereby, the pigment produces color by light interference of a ray reflected on a surface of the transparent inorganic compound layer and a ray passed through the transparent inorganic compound layer and reflected on a surface of the metallic layer. Thus, the pigment is excellent in coloring power and hiding power, and particularly useful for an automotive finishing paint.

Pigment

A pigment of this invention comprises a ceramic scaly substrate, and metal dots or alloy dots formed on the surfaces of ceramic scaly substrate in the ratio of from 0.05 to 95% of the total surface area of ceramic scaly substrate. An inorganic compound coating film may further be formed on all over the surfaces of ceramic scaly substrate, and metal dots or alloy dots may be formed on the surfaces of inorganic compound coating film instead of on the surfaces of ceramic scaly substrate in the same ratio. Thus, this pigment gives various hues with metallic gloss feelings due to combined effect of light reflection and light scattering with metal dots or alloy dots and even light interference with two pairs of reflecting surfaces when the inorganic compound coating film is employed.

An Fe-P alloy film is electrodeposited on a workpiece in a bath comprising 20-80 g/l ferrous ion, 0.01-15 g/l hypophosphorous acid and/or a hypophosphite, and 0.05-5 g/l aluminum ion or a bath comprising 20-80 g/l ferrous ion and 0.01-20 g/l phosphorous acid and/or a phosphite, and optionally aluminum ion at 10.degree.-80.degree. C. and 0.5-30 A/dm.sup.2. There is obtained a crack-free alloy film having a P content of 0.1 to 9.9 wt %.

Iron-phosphorus electroplating bath and electroplating method using same

A composite nickel plated sliding surface is obtained by the formation of a composite nickel plating film on a sliding surface of an automobile part such as an engine cylinder or piston by electroless nickel plating. The plating film contains at least one member of wear resistant particles having an average particle size of 0.1 to 1.0.mu. selected from SiC, TiC, WC, BC.sub.4, TiN, Al.sub.2 O.sub.3 or the like, and also at least one member of lubricating particles having an average particle size of 1 to 10.mu. selected from BN, MoS.sub.2, and Teflon. The nickel plating bath is adjusted to have a phosphorus concentration of 0.5 to 12%. When the matrix of the nickel plating film has a phosphorus concentration of 0.5 to 5%, the film hardness is improved.

Sliding surface of composite nickel-plated sliding member

Growing community of inventors

Nagoya, Japan

Yoshio Takagi