Melt processable, bleach resistant, durable fibers having high elastic recovery and low stress relaxation from polyurethane elastomers

摘要

The present invention provides melt processable, bleach resistant durable fibers having an elastic recovery above 50% after extension to 160% elongation and a stress relaxation below 50% after extension to 150% for 30 minutes which are formed from a soft polyurethane elastomer. This elastomer is comprised of (a) from 75 to 90% weight of a polydiene diol having up to about two terminal hydroxyl groups per molecule and a number average molecular weight between 500 and 20,000, (b) from 9 to 25% weight of a diisocyanate, and (c) from 0.8 to 5% weight of a chain extender which is a low molecular weight aliphatic diol, or a mixture of the low molecular weight aliphatic diol and from 0.1 to 4.0 mol % of a diamine wherein the hard segment content of the polyurethane elastomer is from about 10 to about 30% weight. The present invention further provides a polyurethane elastomer.