Golf ball having thin intermediate layer and methods of manufacture
View Patent ↗A golf ball has a thin intermediate layer, within specified thickness and hardness, situated between a ball core and cover layer. The thin intermediate layer provides for a ball having superior ball spin performance without loss of ball speed. Particular compositions for the intermediate layer, along with methods for spray-coating of a ball core, compression molding over a ball core, and grinding down of a thick intermediate layer that are particularly suited for making this thin intermediate layer, also are disclosed.
1. A golf ball comprising a core, a cover layer on the outer surface of the golf ball, and an intermediate layer between the core and the cover layer, wherein the intermediate layer is situated immediately over a solid surface, comprises an elastomeric material, and has a thickness of from about 0.1 to about 1.0 mm and a Shore A hardness of from about 30 to about 100, wherein the elastomeric material comprises a block copolymer having at least one polymer block comprising an aromatic vinyl compound and at least one polymer block comprising a conjugated diene compound and having a hydroxyl group at a terminal block copolymer, or its hydrogenation product.
2. A golf ball as defined in claim 1 , wherein the intermediate layer has a thickness of from about 0.1 to about 0.77 mm.
3. A golf ball as defined in claim 2 , wherein the intermediate layer has a thickness of from about 0.1 to about 0.65 mm.
4. A golf ball as defined in claim 3 , wherein the intermediate layer has a thickness of from about 0.1 to about 0.33 mm.
5. A golf ball as defined in claim 1 , wherein the intermediate layer has a Shore A hardness of from about 45 to about 100.
6. A golf ball as defined in claim 6 , wherein the intermediate layer has a Shore A hardness of from about 60 to about 100.
7. A golf ball as defined in claim 1 , wherein the core comprises an inner core and a plurality of outer cores encasing the inner core.
8. A golf ball as defined in claim 1 , further comprising a layer of rubber thread situated between the core and the intermediate layer.
9. A golf ball as defined in claim 1 , further comprising a plurality of additional intermediate layers situated between the core and the cover layer.
10. A golf ball comprising a core, an intermediate layer situated immediately over a solid surface of the core, and an outer cover layer, wherein the intermediate layer comprises a polyether amide block copolymer and has a thickness of about 0.3 mm, and wherein the cover layer comprises an amide block copolymer and an ionomer.
11. A golf ball comprising a core, an intermediate layer situated immediately over a solid surface of the core, and an outer cover layer, wherein the intermediate layer comprises a polyether amide block copolymer and has a thickness of about 0.3 mm, and wherein the cover layer comprises: a block copolymer having at least one polymer block comprising an aromatic vinyl compound and at least one polymer block comprising a conjugated diene compound and having a hydroxyl group at a terminal block copolymer, or its hydrogenation product; and an ionomer.
12. A golf ball comprising a core, an intermediate layer situated immediately over a solid surface of the core, and an outer cover layer, wherein the intermediate layer comprises a block copolymer having at least one polymer block comprising an aromatic vinyl compound and at least one polymer block comprising a conjugated diene compound and having a hydroxyl group at a terminal block copolymer, or its hydrogenation product, and the intermediate layer has a thickness of about 0.5 mm.
13. A golf ball as defined in claim 12 , wherein the cover layer comprises an amide block copolymer and an ionomer.
14. A golf ball as defined in claim 12 , wherein the cover layer comprises: a block copolymer having at least one polymer block comprising an aromatic vinyl compound and at least one polymer block comprising a conjugated diene compound and having a hydroxyl group at a terminal block copolymer, or its hydrogenation product; and an ionomer.