Patent ID: 6521164
Filing Date: 2003-02-18
Classification: B29C,B29K,C08G

Abstract:
A method of injection molding an article from a p-phenylene diisocyanate-based thermoplastic polyurethane elastomer comprising the steps of:(a) forming said elastomer as the reaction product of a formulation consisting essentially of: from about 60 to 80% by weight of a hydroxyl-terminated poly(caprolactone) diol; from about 17 to 22% by weight of a p-phenylene diisocyanate; from about 3 to 10% by weight of a first hydroxyl-functional chain extender selected from the group consisting of glycols, amines, diols, and water; and less than about 2% by weight of a second hydroxyl-functional chain extender different from said first chain extender, and selected from the group consisting of hydroquinone dihydroxy ethyl neopentyl glycol, cyclohexane dimethanol, bis (2-hydroxyethyl) bisphenol, and mixtures thereof as effective to modify the crystallinity of said elastomer; (b) heating said elastomer to a temperature of from between about 440 to 480Â° F. to form a melt; and (c) injecting at least a portion of said melt into a mold to form said article.