An object of the present invention is to provide a golf ball that has excellent abrasion resistance and spin performance without sacrificing the processability of the cover, in a golf ball having a cover for which a crosslinkable thermoplastic polyurethane is used as a resin component. The present invention provides a golf ball comprising: a core; and a cover covering the core, wherein the cover is formed from a cover composition containing a thermoplastic polyurethane that has, as a constituting component, a chain extender having an unsaturated carbon-carbon bond.
1. A golf ball comprising:
a core; and a cover covering the core,
wherein the cover is formed from a cover composition containing a thermoplastic polyurethane that has, as a constituting component, a chain extender having an unsaturated carbon-carbon bond,
wherein the chain extender is at least one selected from the group consisting of ethene diol, propene diol, butene diol, pentene diol, hexene diol, heptene diol, octene diol, nonene diol, decene diol, ethyne diol, propyne diol, butyne diol, pentyne diol, hexyne diol, heptyne diol, octyne diol, nonyne diol, and decyne diol,
wherein the thermoplastic polyurethane contains a polyisocyanate component, a high-molecular weight polyol component, and the chain extender component, as the constituting component, and a concentration of the unsaturated carbon-carbon bond in a hard segment component consisting of the polyisocyanate component and the chain extender component falls within a range from 0.2 mole/kg to 1.9 mole/kg, and
wherein the thermoplastic polyurethane has a slab hardness ranging from 15 to 50 in Shore D hardness.
2. The golf ball according to claim 1 , wherein the concentration of the unsaturated carbon-carbon bond in the hard segment consisting of the polyisocyanate component and the chain extender component falls within a range from 0.7 mole/kg to 1.7 mole/kg.
3. The golf ball according to claim 1 , wherein the thermoplastic polyurethane contains dicyclohexylmethane diisocyanate as the polyisocyanate component.
4. The golf ball according to claim 1 , wherein the thermoplastic polyurethane contains polyoxytetramethyleneglycol as the high-molecular weight polyol component.
5. The golf ball according to claim 1 , wherein the cover has a hardness ranging from 20 to 50 in Shore D hardness.
6. The golf ball according to claim 1 , wherein the cover has a thickness ranging from 0.3 mm to 2.5 mm.
7. The golf ball according to claim 1 , wherein the core is a multi-layered core having a center and at least one intermediate layer covering the center.
8. The golf ball according to claim 7 , wherein the intermediate layer has a hardness ranging from 50 to 75 in Shore D hardness.
9. The golf ball according to claim 7 , wherein the intermediate layer has a thickness ranging from 0.3 mm to 6.0 mm.
10. The golf ball according to claim 1 , wherein the core has a hardness difference between a surface hardness and a center hardness ranging from 10 to 40 in JIS-C hardness.
11. The golf ball according to claim 1 , wherein the chain extender has a molecular weight ranging from 30 to 400.
12. The golf ball according to claim 1 , wherein the chain extender is 2-butene-1,4-diol or 2-butyne-1,4-diol.
13. The golf ball according to claim 1 , wherein the high-molecular weight polyol has a number average molecular weight of more than 400 and 10,000 or less.
14. The golf ball according to claim 1 , wherein the high-molecular weight polyol has a hydroxyl value of 500 mg KOH/g or less.