| 摘要 |
The present invention is related to a process for the preparation of thermoplastic polyurethanes by reacting a) organic polyisocyanates and/or organic polyisocyanates modified with b) at least an oligomeric polyhydroxy and/or polyamino compound having an average molecular weight from 400 to 10,000 grams per mol, in the presence or absence of c) chain expanders having at least two Zerewitinoff active hydrogen atoms, and an average molecular weight of less than 400 grams per mol, d) catalysts, e) compounds which are less than difunctional with respect to isocyanates and/or isocyanates which are less than difunctional, and f) adjuvants and/or additives, in a twin screw extrusion apparatus, wherein both screws rotate in the same direction, and having a length/diameter ratio of 20 to 60, and discharging the resulting thermoplastic polyurethane from the configuration extrusion apparatus. |
