THERMOPLASTIC POLYURETHANE FOR PRODUCING HYDROPHILIC FIBERS

摘要

The invention relates to a thermoplastic polyurethane that can be obtained by reacting at least the following components: an isocyanate having two isocyanate groups, a first poly(ethylene glycol) polyether diol of the structure (HO-(CH2-CH2-O)x-H) having two isocyanate-reactive groups and a number-average molecular weight Mn >= 6000 and <= 16000 g/mol, a second poly(ethylene glycol) polyether diol of the structure (HO-(CH2-CH2-O)x-H) having two isocyanate-reactive groups and a number-average molecular weight Mn that corresponds to up to 80% of the number-average molecular weight Mn of the first poly(ethylene glycol) polyether diol B1), a chain extender having two isocyanate-reactive groups and a number-average molecular weight Mn >= 60 and < 600 g/mol, optionally a catalyst, and optionally auxiliary agents and additives, wherein the equivalent ratio of isocyanate A) to poly(ethylene glycol) polyether diols B1) and B2) lies between 1.5 : 1.0 and 10.0 : 1.0 and the NCO index, calculated from the quotient of the equivalent ratios of the isocyanate groups multiplied by 100 and the total of the isocyanate-reactive groups, is 90 to 105. The invention further relates to a method for producing the thermoplastic polyurethane according to the invention and to a thermoplastic polyurethane that can be obtained as per the method according to the invention.