| CPC C08G 18/12 (2013.01) [C08G 18/3206 (2013.01); C08G 18/42 (2013.01); C08G 18/44 (2013.01); C08G 18/4808 (2013.01); C08G 18/4825 (2013.01); C08G 18/4854 (2013.01); C08G 18/5045 (2013.01); C08G 18/6511 (2013.01); C08G 18/664 (2013.01); C08G 18/6674 (2013.01); C08G 18/73 (2013.01); C08G 18/7671 (2013.01)] | 20 Claims |
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1. A solvent-free process for preparing thermoplastically processable polyurethane polymers by reacting the following components
(A) one or more essentially linear polyols, wherein a total amount of component (A) has an average molecular weight Mn in a range from 500 g/mol to 5000 g/mol, wherein Mn is calculated from the OH number determined according to DIN53240;
(B) one or more organic polyisocyanates;
(C) one or more linear diols having a molecular weight of 62 g/mol to 500 g/mol;
(D) optionally in the presence of one or more catalysts;
(E) optionally in the presence of additives, auxiliaries, additions, or a combination thereof; and
(F) optionally in the presence of one or more monofunctional chain terminators,
wherein the process comprises:
1) Providing and reacting a mixture comprising the total amount of component (A), a subamount of component (B), and optionally a subamount or a total amount of component (D), component (E), component (F), or a combination thereof to afford an NCO-functional prepolymer, wherein in process step 1) a molar ratio of component (B) to component (A) is in a range from 1.1:1.0 to 5.0:1.0;
2) Reacting the NCO-functional prepolymer from process step 1) with a total amount of component (C) to obtain an OH-functional prepolymer, optionally in the presence of a further subamount of component (D), component (E), component (F), or a combination thereof; and
3) Reacting the OH-functional prepolymer from process step 2) with a remaining amount of component (B) and any remaining amount of component (D), component (E), component (F), or a combination thereof to obtain the thermoplastically processable polyurethane, wherein over all process steps a molar ratio of component (B) to a sum of component (A) and component (C) is in a range from 0.9:1.0 to 1.2:1.0.
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