Multi-layer golf ball
View Patent ↗Golf balls consisting of a dual core and a dual cover are disclosed. The dual core consists of an inner core layer formed from a rubber composition and an outer core layer formed from a highly neutralized polymer composition.
1. A golf ball consisting essentially of:
an inner core layer formed from a rubber composition and having a center hardness (H center ) of 60 Shore C or greater, and an outer surface hardness of 80 Shore C or greater;
an outer core layer having a diameter of 1.4 inches to 1.55 inches and a specific gravity of from 0.95 g/cc to 0.99 g/cc, formed from a highly neutralized polymer composition comprised of a copolymer of an α-olefin and a C 3 -C 8 α, β-ethylenically unsaturated carboxylic acid and having a material hardness (H outer core material ) of 35 Shore D or greater;
an inner cover layer formed from a thermoplastic composition and having a material hardness (H inner cover material ) of 95 Shore C or less; and
an outer cover layer formed from a composition selected from the group consisting of polyurethanes, polyureas, and copolymers and blends thereof.
2. The golf ball of claim 1 , wherein the outer core layer composition has a modulus within the range of 25,000 psi to 75,000 psi.
3. The golf ball of claim 1 , wherein the outer core layer composition has a moisture vapor transmission rate of 8 g-mil/100in 2 /day or less.
4. The golf ball of claim 1 , wherein H center is from 60 Shore C to 80 Shore C.
5. The golf ball of claim 1 , wherein the outer surface hardness of the inner core layer is from 80 Shore C to 90 Shore C.
6. The golf ball of claim 1 , wherein H outer core material is 45 Shore D or greater.
7. The golf ball of claim 1 , wherein the outer cover has a surface hardness (H cover ) from 40 Shore D to 65 Shore D.
8. The golf ball of claim 1 , wherein a sphere formed from the outer core layer composition has a compression of 70 to 110.
9. The golf ball of claim 1 , wherein the core has an overall dual core diameter of from 1.5 inches to 1.55 inches.
10. A golf ball consisting essentially of:
an inner core layer formed from a rubber composition and having a center hardness (H center ) of about 50 Shore C or greater, and an outer surface hardness of about 80 Shore C or greater;
an outer core layer having an outer diameter of 1.51 to 1.54 and a specific gravity of from 0. 95 g/cc to 0.99 g/cc, formed from a highly neutralized polymer composition and having a material hardness (H outer core material ) of about 35 Shore D or greater;
an inner cover layer having a thickness of 0.03 inches to 0.045 inches and formed from a thermoplastic composition and having an outer surface hardness (H inner cover ) of from about 75 Shore C to about 95 Shore C; and
an outer cover layer formed from a composition selected from the group consisting of polyurethanes, polyureas, and copolymers and blends thereof.