Nippon Steel Corporation

Takeda Chemical Industries, Inc.

Yoshikatsu Matsuura

Hiroshi Kanai

Joji Oka

Shigeaki Miyabayashi

A one-can thermosetting resin composition comprising (A) a blocked product of hexamethylene diisocyanate or bis(isocyanatomethyl)cyclohexane, or a blocked product of an adduct of hexamethylene diisocyanate or bis(isocyanatomethyl)cyclohexane and (B) a polyester polyol having at least three functional groups, gives tough coating films in yellowing and thermal degradation, and also exhibits increased hardness as well as high flexibility, stain resistance and chemical resistance. Especially, when the resin composition is used for preparing precoated metals, it gives good steel plates, thus being advantageously utilized for, among others, light electric appliances.

One-can thermosetting resin compositions and precoated metal

A one-can thermosetting resin composition comprising (1) a polyester polyol obtained by allowing an aliphatic dicarboxylic acid to react with an aliphatic glycol and polyol having at least three functional groups and (2) a blocked product of .alpha.,.alpha.,.alpha.'.alpha.'-tetramethyl-xylylene diisocyanate or 4,4'-methylene bis (cyclohexyl isocyanate), or a blocked product of an NCO-terminated prepolymer obtained by allowing .alpha.,.alpha.,.alpha.'.alpha.'-tetramethylxylylene diisocyanate and/or 4,4'-methylene bis(cyclohexylisocyanate) to react with an active hydrogen compound, gives tough coating films in yellowing and thermal degradation, and also exhibits increased hardness as well as high flexibility, stain resistance and chemical resistance. Especially, when the resin composition is used for preparing precoated metals, it gives good steel plates, thus being advantageously utilized for, among others, light electric appliances.

A one-can heat-curable resin composition which comprises: (1) a polyester polyol having at least three functional groups; (2) an adduct of an epoxy resin having at least one secondary hydroxyl group with a lactone compound or an alkylene oxide; and (3) a blocked organic polyisocyanate or a product of blocking of a prepolymer having terminal NCO groups obtained by reacting an organic polyisocyanate and an active hydrogen-containing compound, gives a tough and durable coat film showing no yellowing or thermal degradation due to heating at all. Furthermore, said film has a high hardness and is excellent in processability and staining resistance, particularly in mustard staining resistance. In particular, the composition, when used in the production of precoated metal, gives good coated steel sheets, which can be advantageously used in manufacturing household electric appliances and so on.

Growing community of inventors

Minoo, Japan

Yoshikatsu Matsuura