Modification method of polyurethane, polyurethane, polishing pad, and modification method of polishing pad

1. A method for modifying a polishing pad, the method comprising:

preparing a polishing pad comprising in at least a polishing surface thereof, a polyurethane having an ethylenically unsaturated bond; and

treating the polyurethane with a liquid comprising a compound having a conjugated double bond and a functional group selected from the group consisting of a carboxyl group, a metal salt of a carboxyl group, a hydroxyl group, an amino group, a sulfonic acid group, a phosphoric acid group and an imidazole group to obtain a Diels Alder ring substituted with the functional group on the polyurethane.

2. The method of claim 1 ,

wherein the polyurethane comprises a polymer constituent unit derived from a compound having an ethylenically unsaturated bond.

3. The method of claim 2 ,

wherein the compound having an ethylenically unsaturated bond comprises at least one compound selected from the group consisting of cis-2-butene-1,4-diol, 4,5-bis(hydroxymethyl)imidazole, 5-norbornene-2,3-dimethanol, cis-2-nonene-1-ol, cis-3-nonene-1-ol, cis-3-octene-1-ol, and polybutadiene diol.

4. A modified polishing pad obtained according to the method of claim 1 .

5. The polishing pad

of claim 4 ,

wherein the polishing surface has a zeta potential at a pH of 3.0 of −1.0 mV or less.

6. The method of claim 1 , wherein the polyurethane is a thermoplastic polyurethane.

7. The method of claim 6 , wherein the polishing pad comprises a molded body of the thermoplastic polyurethane.

8. The method of claim 1 , wherein the polishing pad has at least one groove for sufficiently supplying a slurry to the polishing surface, wherein a depth of the groove is from 0.2 to 1.8 mm and a width of the groove is from 0.1 to 3.0 mm.

9. The method of claim 1 , wherein the polishing surface of the modified polishing pad has a contact angle with water of 80 degrees or less.

10. A method for modifying a polishing pad, the method comprising:

preparing a polishing pad comprising, in at least a surface thereof, a polyurethane having a conjugated double bond; and

treating the polishing surface with a liquid comprising a compound having an ethylenically unsaturated bond and a functional group selected from the group consisting of a carboxyl group, a hydroxyl group, an amino group, a sulfonic acid group, a phosphoric acid group and an imidazole group to obtain a Diels Alder ring substituted with the functional group on the polyurethane.

11. The method of claim 10 ,

wherein the polyurethane comprises a polymer constituent unit derived from a compound having a conjugated double bond.

12. The method of claim 11 ,

wherein the compound having a conjugated double bond comprises at least one compound selected from the group consisting of 4,5-bis(hydroxymethyl)imidazole, 4-hydroxymethyl-5-methylimidazole, and polyethylene furanoate.

13. A modified polishing pad obtained according to the method of claim 10 .

14. The polishing pad

of claim 13 ,

wherein the polishing surface has a zeta potential at a pH of 3.0 of −1.0 mV or less.

15. The method of claim 10 , wherein the polyurethane is a thermoplastic polyurethane.

16. The method of claim 15 , wherein the polishing pad comprises a molded body of the thermoplastic polyurethane.

17. The method of claim 10 , wherein the polishing pad has at least one groove for sufficiently supplying a slurry to the polishing surface, wherein a depth of the groove is from 0.2 to 1.8 mm and a width of the groove is from 0.1 to 3.0 mm.

18. The method of claim 10 , wherein the polishing surface of the modified polishing pad has a contact angle with water of 80 degrees or less.