Polyester polyol, polyurethane, obtained using the same, process for production thereof, and molded polyurethane

1. A process for producing a polyurethane, which comprises using a polyester polyol (a-1), a polyether polyol (b) other than said polyester polyol (a-1), an isocyanate compound (c) and a chain extender (d) as a raw material to produce a polyurethane, wherein the polyester polyol (a-1) is a polyester polyol (a-1) obtained by forming an ester bond between either a carboxyl group of a polycarboxylic acid (i-1) having a polysiloxane framework and a plurality of carboxyl groups or an ester group of a polycarboxylic acid ester (i-2) having a polysiloxane framework and a plurality of ester groups, and a hydroxyl group of a polyether polyol (ii).

2. The process for producing a polyurethane according to claim 1 , which comprises obtaining a mixture of the polyester polyol (a-1) and the polyether polyol (b).

3. The process for producing a polyurethane according to claim 2 , which comprises reacting the mixture obtained by the step of obtaining a mixture of the polyester polyol (a-1) and the polyether polyol (b) with the isocyanate compound (c) to obtain a prepolymer having an isocyanate group at both ends thereof.

4. The process for producing a polyurethane according to claim 1 , wherein the polyester polyol (a-1) has an ester bond formed between two terminal carboxyl groups in one molecule of the polycarboxylic acid (i-1) having a polysiloxane framework and a plurality of carboxyl groups and terminal hydroxyl groups in two molecules of the polyether polyol (ii).

5. The process for producing a polyurethane according to claim 1 , wherein the polyester polyol (a-1) is obtained using polytetramethylene ether glycol as the polyether polyol (ii).

6. The process for producing a polyurethane according to claim 1 , wherein the polyester polyol (a-1) has a number-average molecular weight of 1,000-4,000.

7. The process for producing a polyurethane according to claim 1 , wherein the polyester polyol (a-1) is used in an amount of 0.1-10% by weight based on the total amount of the polyester polyol (a-1) and the polyether polyol (b) to be used.

8. The process for producing a polyurethane according to claim 1 , wherein the isocyanate compound (c) is an aromatic polyisocyanate.

9. The process for producing a polyurethane according to claim 1 , wherein the chain extender (d) is a polyamine compound.

10. A polyurethane obtained by the process for producing a polyurethane according to claim 1 .

11. A polyurethane film comprising the polyurethane according to claim 10 .

12. A polyurethane fiber comprising the polyurethane according to claim 10 .

13. A molded object comprising a polyurethane obtained from a polysiloxane polyol (a-2) represented by the following structural formula (1), a polyether polyol (b) other than said polysiloxane polyol (a-2), an isocyanate compound (c) and a chain extender (d), wherein the relative proportion of silicon atoms to carbon atoms in the surface of the molded object, Si/C, is 0.03-0.5:1

wherein in formula (1), the two R 1 each independently are an alkylene group having 1-15 carbon atoms, the two R 2 each independently are an alkylene group having 2-6 carbon atoms, x is an integer of 1, the two y's each independently are an integer of 5-50, and n is an integer of 1-100.

14. The molded object according to claim 13 , wherein the polyether polyol (b) is polytetramethylene ether glycol.

15. The molded object according to claim 13 , wherein the polysiloxane polyol (a-2) has a number-average molecular weight of 500-5,000.

16. The molded object according to claim 13 , wherein the polyisocyanate compound (c) is an aromatic polyisocyanate.

17. The molded object according to claim 13 , wherein the chain extender (d) is a polyamine compound.

18. The molded object according to claim 13 , which is a polyurethane film.

19. The molded object according to claim 13 , which is a polyurethane fiber.

20. The molded object according to claim 13 , wherein the polyurethane is a polyurethane obtained by mixing the polysiloxane polyol (a-2) with the polyether polyol (b) to obtain a polyol mixture and then reacting the mixture with the polyisocyanate compound (c) and the chain extender (d).

21. The molded object according to claim 13 , wherein the polyurethane is a polyurethane obtained using a polyol mixture prepared by introducing and the polysiloxane polyol (a-2) through a line and the polyether polyol (b) through a separate line and mixing or dispersing polyol (a-2) and polyol (b).

22. A molded object comprising a polyurethane obtained from a polysiloxane polyol (a-2) represented by the following structural formula (I), a polyether polyol (b) other than said polysiloxane polyol (a-2), an isocyanate compound (c) and a chain extender (d), wherein the relative proportion of silicon atoms to carbon atoms in the surface of the molded object, Si/C, is 0.03-0.5:1

wherein in formula (I), the two R 1 each independently are an alkylene group having 1-15 carbon atoms, the two R 2 each independently are an alkylene group having 2-6 carbon atoms, x is 0, the two y's each independently are an integer of 5-50, and n is an integer of 1-100,

wherein said molded object is a polyurethane fiber.

23. The molded object according to claim 22 , wherein the polyether polyol (b) is polytetramethylene ether glycol.