Polyurethane/urea for producing spandex and its production method

Abstract

Segmented polyurethane / ureas useful for the production of spandex are produced by chain extending, in the presence of a solvent, an isocyanate-terminated prepolymer prepared by reacting a stoichiometric excess of an isocyanate with an isocyanate-reactive component which includes: (1) from about 5 to about 30 equivalent percent of a polyoxypropylene diol having a molecular weight of at least 1500 Da and an unsaturation level less than or equal to 0.03 meq / g; (2) from about 20 to about 60 equivalent percent of a polytetramethylene ether glycol having a molecular weight less than 1000 Da; and (3) from about 25 to about 65 equivalent percent of a polytetramethylene ether glycol having a molecular weight greater than or equal to 1000 Da.

Description

technical field

[0001] The present invention relates to segmented polyurethane / urea, which has excellent elastic, mechanical and thermal properties, to fibers made of such polyurethane / urea and to the production process of such polyurethane / urea and fiber. More specifically, the present invention relates to polyurethane / urea and spandex fibers produced by chain extension of isocyanate-terminated prepolymers in the presence of solvents. The isocyanate-terminated prepolymers are derived from isocyanate-reactive components comprising high molecular weight polytetramethylene ether glycol (PTMEG), low molecular weight PTMEG and up to 30 equivalents based on total isocyanate-reactive components % of low unsaturation, high molecular weight polyoxyalkylene glycols. Background technique

[0002] Polyurethane / urea in the form of fibers and films has been widely used in the textile industry. The term "spandex" is commonly used to describe these polyurethaneureas, which are long-chain...