Three-layer-core golf ball having highly-neutralized polymer outer core layer
View Patent ↗A golf ball includes an inner core layer formed from a thermoset rubber composition. The inner core layer has a first outer surface Shore D hardness and an outer diameter of about 0.8 to 1.40 inches. A thermoplastic outer core layer is formed around the inner core layer, has a second outer surface Shore D hardness, and is formed from a copolymer of ethylene and an α,β-unsaturated carboxylic acid, a magnesium salt of oleic acid, and sufficient cation source to fully-neutralize the acid groups of the copolymer. The golf ball includes an inner cover layer and an outer cover layer. The first outer surface Shore D hardness is greater than the second outer surface Shore D hardness and the outer core layer has a thickness of about 0.01 inches to 0.05 inches.
1. A golf ball comprising:
an inner core layer comprising a thermoset rubber composition and having a first outer surface Shore D hardness and an outer diameter of about 1.0 inch to about 1.6 inches;
a thermoplastic outer core layer having a second outer surface Shore D hardness, and comprising a copolymer of ethylene and an α,β-unsaturated carboxylic acid, a magnesium salt of oleic acid, and sufficient cation source to fully-neutralize the acid groups of the copolymer;
an inner cover layer; and
an outer cover layer;
wherein the first outer surface Shore D hardness is less than the second outer surface Shore D hardness and the outer core layer has a thickness of about 0.02 inches to about 0.150 inches.
2. The golf ball of claim 1 , wherein the inner core outer diameter is about 1.2 to 1.58 inches.
3. The golf ball of claim 2 , wherein the inner core outer diameter is about 1.3 to 1.56 inches.
4. The golf ball of claim 1 , wherein the first outer surface hardness is about 30 Shore D to about 65 Shore D and the second outer surface hardness is about 35 Shore D to about 70 Shore D.
5. The golf ball of claim 4 , wherein the first outer surface hardness is about 35 Shore D to about 60 Shore D and the second outer surface hardness is about 40 Shore D to about 65 Shore D.
6. The golf ball of claim 5 , wherein the first outer surface hardness is about 40 Shore D to about 55 Shore D and the second outer surface hardness is about 45 Shore D to about 60 Shore D.
7. The golf ball of claim 1 , wherein the outer core layer thickness is about 0.04 inches to about 0.125 inches.
8. The golf ball of claim 7 , wherein the outer core layer thickness is about 0.05 inches to about 0.095 inches.
9. A golf ball comprising:
an inner core layer comprising a thermoset rubber composition and having a first outer surface Shore D hardness and an outer diameter of about 0.8 inches to about 1.6 inches;
a thermoplastic outer core layer having a second outer surface Shore D hardness, and comprising a copolymer of ethylene and an α,β-unsaturated carboxylic acid, a magnesium salt of oleic acid, and sufficient cation source to fully-neutralize the acid groups of the copolymer;
an inner cover layer; and
an outer cover layer;
wherein the first outer surface Shore D hardness is greater than the second outer surface Shore D hardness and the outer core layer has a thickness of about 0.02 inches to about 0.150 inches.
10. The golf ball of claim 9 , wherein the inner core outer diameter is about 1.0 inches to about 1.58 inches.
11. The golf ball of claim 10 , wherein the inner core outer diameter is about 1.2 inches to about 1.56 inches.
12. The golf ball of claim 9 , wherein the outer core layer thickness is about 0.04 inches to about 0.125 inches.
13. The golf ball of claim 12 , wherein the outer core layer thickness is about 0.05 inches to about 0.095 inches.