Soft elastic polyurethane films, process of their preparation and their use

摘要

A flexible, elastic polyurethane film (I) is prepared by sintering of a thermoplastic polyurethane (TPU) or TPU mixture powder, having a melt index (190 degrees C, 21.1 N) of 20-100, a relative solution viscosity of 1.15-1.45 and a Shore A hardness of 80-98, by means of a heated mold. A flexible, elastic polyurethane film (I) is prepared by sintering of a thermoplastic polyurethane (TPU) or TPU mixture powder, having a melt index (190 degrees C, 21.1 N) of 20-100, a relative solution viscosity of 1.15-1.45 and a Shore A hardness of 80-98, by means of a heated mold. The TPU powder is prepared by reaction of (A) aromatic and/or aliphatic diisocyanates (B) a linear, hydroxyl terminated polyol having an average mol. wt. of 600-5,000 g/mol and containing an average of 1.8-3.0 Zerewitinoff active hydrogen atoms per molecule. whereby the equivalent ratio of NCO groups to the sum of NCO reactive groups is 0.9:1.0-1.1:1.0.