Patent ID: 6399003
Filing Date: 2002-06-04
Classification: C08G,D01F

Abstract:
A process for preparing melt-spun spandex comprising the steps of:a) contacting in a solvent i) a polymeric glycol selected from the group consisting of poly(tetramethyleneether) glycol and poly(tetramethyleneether-co-3-methyltetramethylene-ether) glycol having a number average molecular weight of 2400-8000, ii) 1,1â€²-methylenebis(4-isocyanatobenzene) at a molar addition ratio of polymeric glycol to isocyanate of 1.8-6.0:1 and iii) a chain extender selected from the group consisting of ethylene glycol, 1,3-propanediol, and 1,4-butanediol, to form a polyurethane; b) adding a monofunctional chain terminator in order to obtain a polyurethane having a number average molecular weight 40,000-150,000 and a softening point of not more than 230Â° C.; c) removing the solvent; and d) melt-spinning the polyurethane to form spandex.