| abstract |
A process for the production of highly elastic elastane fibers (spandex fibers) based on segmented polyurethane (urea) elastomers having high elasticity and, at the same time, high strength values, balanced elastic properties and excellent thermal and hydrothermal behavior, wherein relatively high molecular weight, carbonate-linked, block-like polyester of polyester etherdiols having molecular weight of 3,300 to 7,000 are reacted with macrodiols with diisocyanates in a molecular ratio of 1:2.5 to 1:4.5 to obtain NCO prepolymers which have NCO contents of 2.10 to 4.0% NCO, then the NCO prepolymer is chain-extended with (cyclo)-aliphatic diamines to fom polyurethane (urea) elastomers. |