Mitsui Kinzoku Kogyo Kabushiki Kaisha

Kanetaro Sannohe

Yoshio Sohama

Hirohisa Senzaki

Yoshinobu Nakamura

Toru Iwasaki

Sumiko Yamano

Seiji Mori

This invention is to offer a copper powder for solderable and conductive paints which have an improved solderability, excellent adhesion and conductivity. A copper powder for solderable and conductive paints comprising particles of green caterpillar shape is obtained by crushing particulate dendritic copper powder, and has an oil absorption value (JIS K5101) of up to 20 ml/100 g, a maximum particle diameter of up to 44 .mu.m, an average particle diameter of up to 10 .mu.m, and a hydrogen-reduction loss of up to 0.5%. A process for producing this copper powder for solderable and conductive paints comprises: preparing a copper powder comprising particles of a green caterpillar shape having an average particle diameter of up to 10 .mu.m by crushing dendritic copper powder having a maximum diameter of up to 44 .mu.m by means of a crushing apparatus; treating the copper powders thus obtained with a pickling solution consisting of inorganic acids or organic acids to dissolve and remove any oxidation film on the copper powder surface; washing the copper powder with water; spraying a quick drying organic solvent on the copper powders; and hot-air drying the copper powder, thereby obtaining a copper powder having an oil absorption value of up to 20 ml/100 g and a hydrogen-reduction loss of up to 0.5%.

Copper powder for solderable and electroconductive paints and process

A copper powder for electroconductive paints comprising copper particles and an organic zirconate compound which has been applied as a coating on the surfaces of said particles and an electroconductive paint composition obtained from the copper powder for electroconductive paints. The organic zirconate compounds used in the present invention are an organic zirconate compound (RO).sub.x --Zr--(OR').sub.4-x having an easily hydrolyzable organic group and an organic group which is hardly hydrolyzable and exhibits lipophilicity or a mixture of a zirconium acylate polymer and a higher carboxylic acid ester.

Copper powder for electroconductive paints and electroconductive paint

A process for preparing a copper powder for electroconductive paints, which comprises adding to a dispersion bath of copper powder and a dispersion medium a mixture of a titanium acylate polymer and a higher carboxylic acid ester to form a film of the titanium acylate polymer and the higher caboxylic acid ester on the surfaces of the particles of said copper powder, and if necessary, removing the dispersion medium to obtain the copper powder for electroconductive paints. The copper powder thus obtained is coated on the surfaces of its particles with the titanium acylate polymer and the higher carboxylic acid ester.

Copper powder for electroconductive paints and process for production

A process for preparing a copper powder for electroconductive paints, which comprises adding to a dispersion bath of copper powder and a dispersion medium a mixture of a titanium acylate polymer and a higher carboxylic acid ester to form a film of the titanium acylate polymer and the higher carboxylic acid ester on the surfaces of the particles of said copper powder, and if necessary, removing the dispersion medium to obtain the copper powder for electroconductive paints. The copper powder thus obtained is coated on the surfaces of its particles with the titanium acylate polymer and the higher carboxylic acid ester.

Growing community of inventors

Takehara, Japan

Kanetaro Sannohe