| abstract |
The instant invention is directed to a continuous process for the production of thermoplastic polyurethanes by reacting n A. one or more substantially linear polyols having molecular weights in the range from 400 to 10,000, n B. one or more organic diisocyanates and n C. a hydroxyl-group-containing chain extender having a molecular weight below 250, n the ratio of the NCO-groups in component (B) to the Zerewitinoff-active groups in components (A) and (C) lying between 0.90 and 1.2, in extruders, characterized in that the chain extender (C) used is a mixture of at least two different glycols, of which one is present in a quantity of from 50 to 99% by weight, based on the total amount of component (C), and a second in a quantity of from 1 to 50% by weight, based on the total amount of component (C). |