The object of the present invention is to provide a golf ball with superior abrasion resistance and resilience. The present invention provides a golf ball of the present invention comprises a core and a cover that covers the core. The cover contains a polyurethane resin and an organically modified layered silicate, and an interlayer distance of the organically modified layered silicate measured by X-ray diffraction is in a range from 2.5 nm to 15 nm.
1. A golf ball comprising a core and a cover that covers the core, wherein
the cover contains a polyurethane resin and an organically modified layered silicate, and
an interlayer distance of the organically modified layered silicate measured by X-ray diffraction after molding into the cover is in a range from 2.5 nm to 15 nm.
2. The golf ball according to claim 1 , wherein the interlayer distance of the organically modified layered silicate measured by X-ray diffraction is in a range from 2.6 nm to 14.5 nm.
3. The golf ball according to claim 1 , wherein the interlayer distance of the organically modified layered silicate measured by X-ray diffraction is in a range from 2.7 nm to 14.0 nm.
4. The golf ball according to claim 1 , wherein the melt viscosity (210° C.) of the polyurethane resin is in a range from 1,500 P to 30,000 P.
5. The golf ball according to claim 1 , wherein the melt viscosity (210° C.) of the polyurethane resin is in a range from 5,000 P to 20,000 P.
6. The golf ball according to claim 1 , wherein the amount of the organically modified layered silicate in the cover is in a range from 0.01 part to 10 parts by mass per 100 parts by mass of the polyurethane resin.
7. The golf ball according to claim 1 , wherein the organically modified layered silicate includes a layered silicate that is organically modified by an organic ammonium ion.
8. The golf ball according to claim 7 , wherein the layered silicate is at least one selected from a smectite group consisting of montmorillonite, beidellite, nontronite, saponite, ferrous saponite, hectorite, sauconite, and stevensite.
9. The golf ball according to claim 1 , wherein the slab hardness of the cover is in a range from 70 to 98 in Shore A hardness.
10. A golf ball comprising a core and a cover that covers the core, wherein
the cover contains
a polyurethane resin having a melt viscosity (210° C.) ranging from 1,500 P to 30,000 P, and
an organically modified layered silicate which is obtained by modifying a layered silicate selected from a smectite group consisting of montmorillonite, beidellite, nontronite, saponite, ferrous saponite, hectorite, sauconite, and stevensite by an organic ammonium ion, and
an interlayer distance of the organically modified layered silicate measured by X-ray diffraction after molding into the cover is in a range from 2.5 nm to 15 nm.
11. A golf ball manufacturing method for manufacturing a golf ball, comprising the steps of:
organically modifying a layered silicate by using an organic cation to prepare an organically modified layered silicate;
mixing the organically modified layered silicate and a polyurethane resin to prepare a nanocomposite urethane having an interlayer distance of the layered silicate in a range from 2.0 nm to 15 nm before the cover forming step; and
forming a cover such that the organically modified layered silicate in the cover has an interlayer distance measured by X-ray diffraction after molding into the cover in a range from 2.5 nm to 15 nm, by using the nanocomposite urethane and an additive.
12. The method according to claim 11 , wherein
the organically modified layered silicate and the polyurethane resin are mixed by using a twin-screw extruder at the mixing step, under a mixing condition of a mixing temperature in a range from 140° C. to 220° C.
13. The method according to claim 11 , wherein
at the cover forming step, the nanocomposite urethane and the additive are mixed, and injection-molding of the cover are conducted, both by using a twin-screw extruder under a mixing temperature in a range from 150° C. to 220° C.