Low VOC low tack gel coat resin
AssigneeCook Composites and Polymers Co.
InventorsMing Yang Zhao, L. Scott Crump, Chih-Pin Hsu, Erwoan Pezron
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Abstract
A low tack, low VOC gel coat is disclosed comprising a unsaturated polyester resin derived from maleic anhydride and up to about 30% of an organic solvent. The resin is characterized by: a viscosity of less than or equal to about 1750 cp at 70% NVM in styrene; a glass transition temperature greater than or equal to about 11° C.; and a weight average molecular weight less than or equal to about 6,050. A process for making such a gel coat is also disclosed.
Claims25
A low VOC, low tack gel coat composition comprising:
- (A) a unsaturated polyester resin derived from at least two reactants, one reactant of which is maleic anhydride, the resin characterized by:
- (a) a viscosity at 500 s−1 in styrene solution, at a concentration of 70% non-volatile matter, less than or equal to about 1750 cp;
- (b) a glass transition temperature greater than or equal to about 11° C.;
- and, (c) a weight average molecular weight, Mw, less than or equal to about 6,050;
- and,
- (B) up to about 34% by weight, based on the total weight of the composition, of an organic solvent capable of polymerization with the unsaturated polyester resin.
A low VOC, low tack gel coat composition comprising:
- (A) a unsaturated polyester resin obtained by (1) reacting a first reaction mixture comprising a dicarboxylic acid, a glycol and a polyol to form a first reaction product, and (2) reacting a second reaction mixture comprising the first reaction product and further reactant monomers comprising maleic anhydride and a monocarboxylic acid to form the unsaturated polyester resin;
- and
- (B) up to 70% by weight of the total composition of an organic solvent capable of polymerizing with the unsaturated polyester resin,
- wherein the unsaturated polyester resin is characterized by:
- (a) a viscosity at 500 s−1 in styrene solution, at a concentration of 70% non-volatile matter, less than or equal to about 1750 cp;
- (b) a glass transition temperature greater than or equal to about 11° C.:
- and, (c) a weight average molecular weight, Mw, less than or equal to about 6,050.
A process for preparing a low VOC, low tack gel coat, the process comprising the steps of:
- (A) forming a first reaction mixture comprising reactant monomers comprising a dicarboxylic acid, and at least one polyol;
- (B) reacting the first reaction mixture to form a first reaction product;
- (C) forming a second reaction mixture comprising the first reaction product and further reactant monomers comprising maleic anhydride and a monocarboxylic acid;
- and
- (D) reacting the second reaction mixture to form a unsaturated polyester resin, wherein the unsaturated polyester resin is characterized by:
- (a) a viscosity at 500 s−1 in styrene solution, at a concentration of 70% non-volatile matter, less than or equal to about 1750 cp;
- (b) a glass transition temperature greater than or equal to about 11° C.;
- and, (c) a weight average molecular weight, Mw, less than or equal to about 6,050.
Dependencies are inferred from the claim text.