Akzo Nobel Coatings International B.v.

Koji Miyabe

Takahiro Tsujita

Nobuhiro Nishida

Hiroki Mizutani

Taichiro Kohashi

The present invention relates to a thermosetting composition characterized in that it contains (A) a polyester resin of number average molecular weight 1,000-10,000, hydroxyl value 5-200 mg KOH/g and, (B) 0.5-2.0 equivalents relative to the hydroxyl groups of the aforesaid component (A) of a compound (B) which is a blocked aliphatic isocyanate compound having reactivity with the hydroxyl groups of component (A), wherein the blocking is with methyl ethyl ketoxime and/or &#x3b5;-caprolactam, (C) 0.05-5 parts by weight of a bismuth compound, per 100 parts by weight of total resin solids of component (A) and component (B), and (D) 0.5-50 parts by weight of an organosilicate represented by the following general formula (I) and/or a condensation product thereof, relative to 100 parts by weight of total resin solids of component (A) and component (B) wherein R, R, Rand Rin the formula each mean hydrogen atom or 1-10 carbon organic group, and can be the same or different, n is 1. By using the thermosetting, not only does stain resistance appear a short time after painting, but also excellent stain resistance is maintained for a long period, which fulfil the paint film performance requirements for painted steel sheet such as water resistance and bending workability and which have high environmental protection qualities and safety. 

Thermosetting composition, paint finishing method and method for producing a painted article

[Purpose] To provide a thermosetting composition with which it is possible to obtain paint films which not only display stain resistance for a short period after application, but with which excellent stain resistance can also be expected for longer periods, and which comply with the paint film properties required for painted steel sheet such as water resistance and bending workability, and have high environmental protection and safety qualities. [Solution] The present invention relates to a thermosetting composition, wherein it contains, as essential components, (A) a polyester resin of number average molecular weight 1,000-10,000 and hydroxyl value 5-200 mg KOH/g and, (B) 0.5 to 2.0 equivalents, relative to the hydroxyl groups of the aforesaid component (A), of a compound (B) which is a blocked aliphatic polyisocyanate compound having reactivity to the hydroxyl groups of component (A), wherein the blocks are methyl ethyl ketone oxime and/or &#x3b5;-caprolactam, (C) 0.05 to 5 mass %, relative to the total resin solids mass of component (A) and component (B), of an organotin compound represented by the following general formula (I) [Chem.1] R&#x2014;Sn-(O)C&#x2550;(O)&#x2014;R)(I) (Rin the formula represents an organic group wherein it has 1-24 carbons, and is directly bound to the Sn atom via a C atom. Rrepresents an organic group wherein it has 1-24 carbons, and is directly bound to the C atom of the (C&#x2550;O) via a C atom), and (D) 0.5 to 50 mass %, relative to the total resin solids mass of component (A) and component (B), of an organosilicate represented by the following general formula (II) and/or a condensation product thereof [Chem.2] (R, R, Rand Rin the formula are each a hydrogen atom or 1-10 carbon organic group, and may be the same or different, n is 1). 

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Yokohama, Japan

Koji Miyabe