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US 4,859,760 AGranted
Polyurethane powder coating compositions
AssigneeEastman Kodak Company
InventorsFred W. Light, Jr., James D. Hood, Yeong-Ho Chang
Life of this patent
Estimating the term…
Abstract
Disclosed are polyurethane powder coating compositions comprising at least one amorphous polyester, at least one semi-crystalline polyester, and a polyisocyanate crosslinking agent. Coatings made from such powder compositions provide a unique combination of good hardness and flexibility, while the powder from which they are made has good storage stability.
Claims13
Polyurethane powder coating composition in solid form comprising
- (a) abou 10-80 weight % of at least one amorphous polyester containing free hydroxyl groups and having a Tg of greater than 40.degree. C., a hydroxyl number of about 20-200, and an inherent viscosity of about 0.1-0.5.
- (b) abou 10-80 weight % of at least one semi-crystalline polyester containing free hydroxyl groups and having a Tg of about -10 to about 50.degree. C., a number average molecular weight of about 500-10,000, a heat of ofusion of greater than 5 calories per gram--.degree. C., a hydroxyl number of about 20-200, an inherent viscosity of about 0.1-0.5, and
- (c) about 5-30 weight % of a polyisocyanate crosslinking agent.
- the sum of (a), (b) and (c) being 100%.
1 more element
Dependencies are inferred from the claim text.