The present invention provides a golf ball, which is superior in shot feel, rebound characteristics and laminar separation resistance. The present invention relates to a golf ball comprising at least one layer of a core and a cover formed on the core, wherein the cover is formed from a cover resin composition mainly comprising a mixture of (a) ionomer resin, and (b) a functional group modified polyester-based thermoplastic elastomer as a base resin.
1. A golf ball comprising at least one layer of a core and a cover formed on the core, wherein the cover is formed from a cover resin composition mainly comprising a mixture of:
(a) ionomer resin, and
(b) a functional group modified polyester-based thermoplastic elastomer as a base resin, and
wherein the cover resin composition has a Shore D hardness of 50 to 67, and the cover has a thickness of 0.5 to 2.5 mm.
2. The golf ball according to claim 1 , wherein the functional group modified polyester-based thermoplastic elastomer is modified by a functional group selected from the group consisting of epoxy group, acid group, ester group, hydroxyl group and anhydride group.
3. The golf ball according to claim 1 , wherein the functional group modified polyester-based thermoplastic elastomer has a Shore D hardness of not more than 50.
4. The golf ball according to claim 1 , wherein a weight ratio (a/b) of the ionomer resin (a) to the functional group modified polyester-based thermoplastic elastomer (b) is within the range of 40/60 to 95/5.
5. The golf ball according to claim 2 , wherein functional group modified polyester-based thermoplastic elastomer has a Shore D hardness of not more than 50.
6. The golf ball according to claim 5 , wherein a weight ratio (a/b) of the ionomer resin (a) to the functional group modified polyester-based thermoplastic elastomer (b) is within the range of 40/60 to 95/5.
7. The golf ball according to claim 1 , wherein the mixture is present in the cover resin composition in an amount not less than 80% by weight.
8. The golf ball according to claim 1 , wherein the mixture is present in the cover resin composition in an amount not less than 90% by weight.
9. The golf ball according to claim 1 , wherein a weight ratio (a/b) of the ionomer resin (a) to the functional group modified polyester-based thermoplastic elastomer (b) is within the range of 50/50 to 95/5.
10. The golf ball according to claim 1 , wherein a weight ratio (a/b) of the ionomer resin (a) to the functional group modified polyester-based thermoplastic elastomer (b) is within the range of 60/40 to 95/5.
11. The golf ball according to claim 1 , wherein the ionomer resin has a Shore D hardness of 50 to 70.
12. The golf ball according to claim 1 , wherein the ionomer resin has a Shore D hardness of 55 to 63.
13. The golf ball according to claim 1 , wherein the functional group modified polyester-based thermoplastic elastomer has a Shore D hardness of 5 to 40.
14. The golf ball according to claim 1 , wherein the functional group modified polyester-based thermoplastic elastomer has a Shore D hardness of 10 to 30.
15. The golf ball according to claim 1 , wherein the cover resin composition has a Shore D hardness of 52 to 67.
16. The golf ball according to claim 1 , wherein the cover resin composition has a Shore D hardness of 55 to 65.
17. The golf ball according to claim 1 , wherein the functional group modified polyester-based thermoplastic elastomer is modified by a functional group selected from the group consisting of epoxy group and anhydride group.