Multi-layer core golf ball
View Patent ↗Golf balls consisting of a multi-layer core and a cover are disclosed. The multi-layer core comprises a thermoset rubber center, a thermoplastic intermediate core layer, and a thermoset rubber outer core layer.
1. A golf ball comprising:
a center formed from a first thermoset rubber composition and having a diameter of from 1.250 inches to 1.580 inches, a center hardness of from 40 Shore C to 75 Shore C, a surface hardness of from 50 Shore C to 95 Shore C, and a positive hardness gradient wherein the difference between the center hardness and the surface hardness of the center is from 10 to 45 Shore C;
an intermediate core layer formed from a thermoplastic composition and having a thickness of 0.005 inches to 0.100 inches and a surface hardness of greater than 50 Shore D;
an outer core layer formed from a second thermoset rubber composition and having a thickness of 0.010 inches to 0.100 inches and a surface hardness of 50 Shore C or greater; and
a cover layer having a thickness of from 0.010 inches to 0.050 inches and a surface hardness of 60 Shore D or less;
wherein the specific gravity of at least one of the center, intermediate core layer, and outer core layer is less than 1.05 g/cc.
2. The golf ball of claim 1 , wherein the center has a specific gravity of greater than 1.25 g/cc.
3. The golf ball of claim 1 , wherein the center has a specific gravity of 1.30 g/cc or greater.
4. The golf ball of claim 1 , wherein the intermediate core layer has a specific gravity of 1.00 g/cc or less.
5. The golf ball of claim 1 , wherein the intermediate core layer has a specific gravity of 0.95 g/cc or less.
6. The golf ball of claim 1 , wherein the outer core layer has a specific gravity of 0.95 g/cc or less.
7. The golf ball of claim 1 , wherein the outer core layer has a specific gravity of 0.90 g/cc or less.
8. The golf ball of claim 1 , wherein the center has a specific gravity of greater than 1.25 g/cc, the intermediate core layer has a specific gravity of 1.00 g/cc or less, and the outer core layer has a specific gravity of 0.95 g/cc or less.
9. The golf ball of claim 1 , wherein the center has a specific gravity of 1.30 g/cc or greater, the intermediate core layer has a specific gravity of 0.95 g/cc or less, and the outer core layer has a specific gravity of 0.90 g/cc or less.
10. The golf ball of claim 1 , wherein the specific gravity of at least one of the center, intermediate core layer, and outer core layer is greater than 1.25 g/cc.
11. The golf ball of claim 10 , wherein the center has a specific gravity of greater than 1.25 g/cc.
12. The golf ball of claim 10 , wherein the center has a specific gravity of 1.30 g/cc or greater.
13. The golf ball of claim 11 , wherein the intermediate core layer has a specific gravity of 1.00 g/cc or less.
14. The golf ball of claim 11 , wherein the intermediate core layer has a specific gravity of 0.95 g/cc or less.
15. The golf ball of claim 11 , wherein the outer core layer has a specific gravity of 0.95 g/cc or less.
16. The golf ball of claim 11 , wherein the outer core layer has a specific gravity of 0.90 g/cc or less.