Method for producing thermoplastically processable polyurethane polymers
The present invention relates to a novel process for preparing thermoplastically processable polyurethanes, to thermoplastically processable polyurethane obtainable from the process and to compositions, articles and uses of these polyurethanes.
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.
2. The process as claimed in claim 1 , wherein in process step 2) a molar ratio of NCO-functional prepolymer to component (C) is less than 1.0.
3. The process as claimed in claim 1 , wherein component (A) comprises one or more polyols comprising a polyester diol, a polyether diol, a polycarbonate diol, or a mixture of at least two of these.
4. The process as claimed in claim 1 , wherein component (A) comprises one or more polyester diols having an average molecular weight Mn in the range from 500 g/mol to 5000 g/mol, wherein Mn is calculated from the OH number determined according to DIN53240.
5. The process as claimed in claim 1 , wherein component (A) comprises one or more polycarbonate diols having an average molecular weight Mn in the range from in the range from 500 g/mol to 5000 g/mol, wherein Mn is calculated from the OH number determined according to DIN53240.
6. The process as claimed in claim 1 , wherein component (A) comprises one or more polyether diols having an average molecular weight in the range from 500 g/mol to 5000 g/mol, wherein Mn is calculated from the OH number determined according to DIN53240.
7. The process as claimed in claim 6 , wherein the one or more polyether diols are independently of one another polyethers based on a polymer of ethylene oxide or propylene oxide or a mixture of different polymers of these raw materials.
8. The process as claimed in claim 6 , wherein the one or more polyether diols are independently of one another polyethers based on a polymer of tetrahydrofuran.
9. The process as claimed in claim 1 , wherein component (B) comprises a diphenylmethane diisocyanate isomer mixture having a 4,4′-diphenylmethane diisocyanate content of more than 96% by weight based on the total weight of component (B).
10. The process as claimed in claim 1 , wherein component (B) comprises 1,6-hexamethylene diisocyanate.
11. The process as claimed in claim 1 , wherein component (C) comprises one or more diols comprising ethane-1,2-diol, butane-1,4-diol, hexane-1,6-diol, 1,4-di(beta-hydroxyethyl) hydroquinone, or a mixture of at least two of these.
12. The process as claimed in claim 1 , wherein the thermoplastically processable polyurethane polymer has a hardness of less than 60 Shore A or greater than 80 Shore D, in each case determined according to DIN ISO 7619-1 (2012 Feb. 1).
13. A thermoplastically processable polyurethane polymer obtained by a process as claimed in claim 1 .
14. A thermoplastically processable polyurethane polymer having a Charpy impact strength of ≥15 KJ/m 2 at −30° C. determined according to DIN EN ISO179/1eA, obtained by reacting the following components
(A) one or more essentially linear polyether diols based on a polymer of tetrahydrofuran, wherein a total amount of component (A) has an average molecular weight Mn of greater than 1450 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 one or more additives, auxiliaries, additions, or a combination thereof; and
(F) optionally in the presence of one or more monofunctional chain terminators,
wherein the reaction of the components is performed in a solvent-free fashion and comprises the following steps:
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 the 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.
15. The thermoplastically processable polyurethane polymer as claimed in claim 14 , wherein the thermoplastically processable polyurethane polymer has a Charpy impact strength of at least 30 KJ/m 2 , determined according to DIN EN ISO179/1eA (2010) at −30° C.
16. A composition containing at least one thermoplastically processable polyurethane polymer as claimed in claim 13 and an additive.
17. An article comprising a thermoplastically processable polyurethane polymer as claimed in claim 13 .
18. An injection molded article, extruded article, or coating, comprising a thermoplastically processable polyurethane polymer as claimed in claim 13 .
19. A composition containing a thermoplastically processable polyurethane polymer as claimed in claim 14 and an additive.
20. An article comprising a thermoplastically processable polyurethane polymer as claimed in claim 14 .