Crystalline, grindable polyurethane prepolymers
AssigneeWarner-Lambert Company
InventorsCharles W. McGary, Jr., Delmer R. Rhodes, Vincent J. Pascarella
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Abstract
A crystalline grindable end-blocked prepolymer useful in providing a polyurethane elastomer having a 100% modulus less than approximately 250 psi, tensile of 3500 to 6500 psi, and less than 30% initial tensile set, said prepolymer being the product of reacting an organic polyisocyanate, a long chain crystalline diol having an average molecular weight of approximately 500 to 5000, a polyhydroxy cross-linking agent, and an end-blocking agent.
Claims30
A crystalline, grindable, end-blocked prepolymer comprising the reaction product of an organic polyisocyanate, a crystalline long chain diol having an average molecular weight of approximately 500 to 5000, a polyhydroxy crosslinking agent and an end blocking agent, wherein the resulting polyurethane elastomer has a 100% modulus less than approximately 250 psi, a 300% modulus between 200 and 450 psi and tensile of about 3500 to 6500 psi.
A crystalline, grindable, end-blocked prepolymer comprising the reaction product of:
- (a) an organic polyisocyanate selected from the group consisting of 4,4'-diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, and methylene bis (4-cyclohexyl isocyanate),
- (b) a crystalline long chain diol having a molecular weight of 1000 to 5000 selected from the group consisting of polycaprolactone glycol, poly(ethylene adipate) glycol, poly(ethylene succinate) glycol, poly(ethylene sebacate) glycol, poly(butylene adipate) glycol and mixtures thereof,
- (c) a polyhydroxy crosslinking agent,
- (d) a short chain diol extender, and
- (e) an end-blocking agent wherein the resulting polyurethane elastomer has a 100% modulus less than approximately 250 psi, a 300% modulus between 200 and 450 psi and tensile of about 3500 to 6500 psi.
A crystalline, grindable, end-blocked prepolymer comprising the reaction product of:
- (a) about 13 to 23% by weight of an organic polyisocyanate selected from the group consisting of 4,4'-diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, and methylene bis (4-cyclohexyl isocyanate),
- (b) about 70 to 84% by weight of a crystalline long chain diol having a molecular weight of 1000 to 5000 and a melting point of 30.degree. to 55.degree. C. selected from the group consisting of polycaprolactone glycol, poly(ethylene adipate) glycol, poly(ethylene succinate) glycol, poly(ethylene sebacate) glycol, poly(butylene adipate) glycol and mixtures thereof,
- (c) a polyhydroxy crosslinking agent in an amount sufficient to provide a crosslinking degree in the range of approximately 5000 to 30,000 M.sub.c,
- (d) up to about 3% of a short chain diol extender, and
- (e) an end-blocking agent in an amount sufficient to block about 5 to 30% of the isocyanate groups forming said polyisocyanate wherein the resulting polyurethane elastomer has a 100% modulus less than approximately 250 psi, a 300% modulus between 200 and 450 psi and tensile of about 3500 to 6500 psi.
Dependencies are inferred from the claim text.