Shinto Paint Co., Ltd.

Masaaki Nakashio

Takeshi Kuninori

Yasuhiko Tsukamoto

Shoichiro Arakura

Junko Kawashima

Toshiyuki Yamada

Disclosed herein is a resin composition for cationic electrodeposition coating containing (A) an epoxy resin (a base resin) having cationic groups and (B) a blocked polyisocyanate (a curing agent), characterized in that, a blocked polyisocyanate (B) in which a part of the isocyanate groups is polymerized with a polyol and which is blocked by (1) a blocking agent represented by a formula R--(OC.sub.2 H.sub.3 X).sub.n --OH (wherein R is an alkyl having 1-6 carbon atom(s); X is H or methyl; and n is 1-6) and having a molecular weight of not less than 150 and also by (2) another blocking agent having a deblocking temperature of not higher than about 150.degree. C. is used.

Resin composition for cationic electrodeposition coating

A method of coating a metal article by forming a first electrodeposition coating layer having varistor properties on a metal article by an electrodeposition coating method by use of an electrodeposition coating film-forming composition containing from 7 to 50 parts by weight of an electrically semiconductive substance per 100 parts by weight of the solid content of the composition, and then forming a second electrodeposition coating layer on said first electrodeposition coating layer by an electrodeposition coating method by use of an anionic or cationic electrodeposition paint while applying a voltage exceeding the varistor voltage. The coating composition thus-produced has excellent varistor properties with superior corrosion resistance.

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Aichi, Japan

Masaaki Nakashio