Nissan Motor Company Limited

Nippon Oil Fats Co., Ltd.

Shinto Paint Co., Ltd.

Masahide Nagaoka

Katsuya Yamamoto

Tsuneo Sakauchi

Hiroyuki Kishi

Hitoshi Kimura

Yoshinobu Tamura

Eisaku Nakatani

Shosaku Yamamoto

Masayuki Takemoto

Yoichi Masubuchi

Akitoshi Shirasaka

Shinichi Inoue

Naoya Sakai

Masaya Kawabata

Makoto Efumi

Michiaki Wake

A composite paint film coating formed on a steel sheet of an automotive vehicle body. The composite paint film coating is comprised of an electrodeposition paint film (I) coated on the steel sheet, and an intermediate paint film (II) coated on the first paint film. The electrodeposition paint film has a minimum melt viscosity not less than 0.2 during hardening. The electrodepositon paint film is formed of cathodic electrodeposition paint composition which includes a cationic thermosetting resin (1), and an already cross-linked particulate resin (2). The particlate resin is an addition-polymer formed between a fist compound (A) having at least two primary amino groups in a molecule, and a second compound (B) having at least two .alpha.,.beta.-ethylenic unsaturated groups. The particulate resin has an average particle size ranging from 0.01 to 1 .mu.m. The weight ratio ((2)/(1)) in solid content between the particulate resin (2) cationic thermosetting resin (1) is within a range from 0.03 to 0.15. The intermediate paint film (II) has hardening starting time ranging from 5 to 20 minutes.

Composite paint film coating

A composite paint film formed on a steel sheet of an automotive vehicle body. The composite paint film comprises an electrodeposition paint film (I) coated on the steel sheet, and an intermediate coat paint film (II) coated on the first paint film. The electrodeposition paint film is formed of an epoxy-based cationic electrodeposition paint composition and has a minimum melt viscosity not less than 0.2 during hardening. The epoxy-based cationic electrodeposition paint composition includes an amine-added epoxy resin (1) of the type which may be hardened with a blocked isocyanate, a colloidal silica-containing gelled particulate (2), and an alkyltin ester compound of a liquid aliphatic carboxylic acid. The above-mentioned colloidal silica-containing gelled particulate is formed by dispersing a mixture of an acrylic copolymer having a hydrolizable alkoxysilane group and a cationic group and a cationic acidic colloidal silica in water to carry out a cross-linking reaction in particles of the colloidal silica. The second paint film (II) has a hardening starting time ranging from 15 to 20 minutes.

Composite paint film

Growing community of inventors

Yokohama, Japan

Masahide Nagaoka