Patent ID: 7838617
Filing Date: 2010-11-23
Classification: C08G,D01F,D04B,D10B,Y10S

Abstract:
1. A method of making a polyurethaneurea comprising the steps of: (a) contacting at least one polymeric glycol selected from the group consisting of polyether glycols and polyester glycols; with a diisocyanate mixture comprising at least about 78 mole percent 4,4′-MDI and at least about 5 mole percent 2,4′-MDI; wherein the molar ratio of the at least one glycol to the total moles of diisocyanate is between about 1:1.5 and about 1:2; (b) contacting the product of step (a) with a composition comprising: (1) a solvent selected from the group consisting of N,N-dimethylacetamide, dimethylformamide, dimethyl sulfoxide, N,N-dimethylpyrrolidinone, and mixtures thereof; (2) at least one chain extender comprising ethylenediamine or a mixture of chain extenders comprising ethylenediamine and a secondary chain extender; wherein ethylenediamine is at least about 90 mole percent of the total moles of chain extenders; (3) a chain terminator selected from the group consisting of diethylamine, diisopropylamine, piperidine, dibutylamine, and mixtures thereof; to form a polymer, wherein the pre-spun IV of the polymer is between about 0.65 and about 1.0 dl/g and the primary amine content is between about 25 and about 70 meq/Kg.