Vapor permeation curable coatings based on alkyd resins
AssigneeJ.G.L. Chemicals Ltd.
InventorsChacko Thankachan, John G. Ritchie, Eugene Sahayada, Asok Sengupta
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Abstract
Improved coating compositions for use in diversified applications, curable by permeation of a tertiary amine vapor or without permeation at room temperature. The composition and the coating process are characterized by the modification of an alkyd resin, having free hydroxyl groups, by reaction with p-hydroxybenzoic acid. The coatings display good flexibility and high gloss as well as good color retention and good adhesion to substrates.
Claims24
A process for producing a coated surface comprising
- (a) applying to a surface to be coated, a liquid film of a urethane forming composition comprising
- (i) an alkyd resin modified with p-hydroxy benzoic acid to provide side chain aromatic hydroxyl groups on the alkyd resin backbone, and
- (ii) at least one organic isocyanate selected from the group consisting of di- and poly-isocyanates, said at least one isocyanate having an at least partial aromatic character, wherein
- (iii) components (i) and (ii) are present in amounts such that the ratio of active hydroxyl hydrogen groups in (i) to isocyanate groups in (ii) is 1:1 to 1.5, and
- (b) curing the composition to form a solid urethane coating.
A curable coating composition comprising:
- (i) an alkyd resin modified with p-hydroxy benzoic acid to provide side chain aromatic hydroxyl groups in the alkyd resin backbone, in admixture with
- (ii) at least one organic isocyanate selected from the group consisting of diisocyanates and polyisocyanates, said isocyanate having an at least partial aromatic character, wherein
- (iii) components (i) and (ii) are present in amounts such that the ratio of active hydroxyl hydrogen groups in (i) to isocyanate groups in (ii) is 1:1 to 1.5.
An article comprising a substrate coated with a cured urethane coating derived from a urethane forming composition comprising
- (i) an alkyd resin modified with p-hydroxy benzoic acid to provide side chain aromatic hydroxyl groups on the alkyd resin backbone, and
- (ii) at least one organic isocyanate selected from the group consisting of di- and poly-isocyanates, said at least one isocyanate having an at least partial aromatic character, wherein
- (iii) components (i) and (ii) are present in amounts such that the ratio of active hydroxyl hydrogen groups in (i) to isocyanate groups in (ii) is 1:1 to 1.5.
Dependencies are inferred from the claim text.