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. At least one of the core layers has a specific gravity of less than 1.05 g/cc and/or at least one of the core layers has a specific gravity of greater than 1.25 g/cc.
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 70 Shore C, and a surface hardness of from 50 Shore C to 95 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 60 Shore D or less;
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 45 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 greater;
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; and
wherein the surface hardness of the outer core layer is less than the surface hardness of the center.
2. The golf ball of claim 1 , wherein the center has a specific gravity of 0.95 g/cc or less.
3. The golf ball of claim 1 , wherein the center has a specific gravity of 0.90 g/cc or less.
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 greater than 1.25 g/cc.
7. The golf ball of claim 1 , wherein the outer core layer has a specific gravity of 1.30 g/cc or greater.
8. The golf ball of claim 1 , wherein the center has a specific gravity of 0.95 g/cc or less, 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 greater than 1.25 g/cc.
9. The golf ball of claim 1 , wherein the center has a specific gravity of 0.90 g/cc or less, 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 1.30 g/cc or greater.