Nippon Ester Co., Ltd.

Tokuzo Nozaki

Katsuyoshi Atsumi

Katsuya Fujimoto

Makiko Sakai

a resin composition for a powder coating comprising a polyester A, which does not substantially set to gel and has a hydroxyl value of at least 1,200 g eq/10.sup.6 g, a polyester B, which does not substantially set to gel and has a hydroxyl value of from 200 to 1,000 g eq/10.sup.6 g, and an inner blocked isocyanate hardener, wherein the weight ratio of polyester A to polyester B is from 70:30 to 10:90 and the difference (absolute value) in gel time between these polyesters A and B is at least 3 minutes.

Resin composition for powder coating

A resin composition for powder coating which comprises a substantially un-gelled polyester A having a hydroxyl value of from 1,200 to 5,000 g eq/10.sup.6 g, a substantially un-gelled polyester B having a hydroxyl value of from 200 to 1,000 g eq/10.sup.6 g, tetramethoxymethyl glycoluril as a curing agent and an organic sulfonic acid compound as a curing catalyst, wherein the weight ratio of polyester A to polyester B is from 70:30 to 10:90 and the difference (absolute value) in the gel time between polyester A and polyester B is at least 3 minutes.

Resin composition for powder coatings

A resin composition for powder coating which comprises a substantially un-gelled polyester A having an acid value of from 1,200 to 5,000 g eq/10.sup.6 g, a substantially un-gelled polyester B having an acid value of from 200 to 1,000 g eq/10.sup.6 g and triglycidyl isocyanurate as a curing agent, wherein the weight ratio of polyester A to polyester B is from 70:30 to 10:90 and the difference (absolute value) in the gel time between polyester A and polyester B is at least 3 minutes. A resin composition for powder coating which causes no problems of polluting a baking oven, which shows less weight loss at the time of reaction and which can form a semi-mat or completely mat stable paint film is provided. These advantages cannot be obtained from any prior art powder coating that comprises a polyester having a large quantity of terminal hydroxyl groups and a blocked isocyanate-based curing agent.

A resin composition for a matte powder coating comprising a polyester A having a hydroxyl value of at least 1,200 g eq/10.sup.6 g, a polyester B having a hydroxyl value of from 200 to 1,000 g eq/10.sup.6 g and a blocked isocyanate hardener, wherein the weight ratio of polyester A to polyester B is from 70:30 to 10:90, the difference (absolute value) in gel time between polyester A and polyester B is at least 3 minutes and the difference (absolute value) in acid value between these polyesters is at least 20 g eq/10.sup.6 g is disclosed.

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Aichi, Japan

Tokuzo Nozaki