HIGHLY-NEUTRALIZED THERMOPLASTIC COPOLYMER CENTER FOR IMPROVED MULTI-LAYER CORE GOLF BALL
A golf ball includes a core formed from a thermosetting rubber composition; a cover; and an intermediate layer disposed between the core and the cover. The intermediate layer is formed from a highly-neutralized thermoplastic copolymer of ethylene and an α,β-unsaturated carboxylic acid, the acid being neutralized by a salt of an organic acid or a suitable base of the organic acid, and sufficient cation source to bring the neutralization to 80% or greater. A sphere resulting from a combination of the core and the intermediate layer has an Atti compression of 60 or greater.
1 . A golf ball comprising:
a core comprising a thermosetting rubber composition;
a cover; and
an intermediate layer disposed between the core and the cover;
wherein the intermediate layer comprises a highly-neutralized thermoplastic copolymer of ethylene and an α,β-unsaturated carboxylic acid, the acid being neutralized by a salt of an organic acid or a suitable base of the organic acid, and sufficient cation source to bring the neutralization to 80% or greater;
and wherein a sphere resulting from a combination of the core and the intermediate layer has an Atti compression of 60 or greater.
2 . The golf ball of claim 1 , wherein the intermediate layer has a flexural modulus of 50,000 psi or greater.
3 . The golf ball of claim 2 , wherein the flexural modulus of the intermediate layer is from 60,000 psi to 70,000 psi.
4 . The golf ball of claim 1 , wherein the core has a diameter of about 0.80 inches to about 1.40 inches, and the cover comprises a thermoset polymer having a hardness of about 45 Shore D to about 60 Shore D and a thickness of about 0.02 inches to about 0.04 inches.
5 . The golf ball of claim 1 , wherein the golf ball has a coefficient of restitution of 0.76 or greater when measured at an incoming velocity of 160 ft/s.
6 . The golf ball of claim 1 , wherein the intermediate layer has a hardness of about 40 Shore D to about 70 Shore D.
7 . The golf ball of claim 1 , wherein the neutralization is 90% or greater.
8 . The golf ball of claim 7 , wherein the neutralization is 100%.
9 . The golf ball of claim 1 , wherein the core comprises an inner core layer and an outer core layer.
10 . The golf ball of claim 9 , wherein the inner core layer has an Atti compression of 30 or less.
11 . A golf ball comprising:
a core;
a cover; and
a first intermediate layer disposed between the core and the cover;
wherein the core comprises a thermosetting polybutadiene rubber and the first intermediate layer comprises a highly-neutralized thermoplastic copolymer of ethylene and an α,β-unsaturated carboxylic acid, the acid being 100% neutralized by a salt of an organic acid, a suitable base of the organic acid, and sufficient a cation source;
and wherein a sphere resulting from a combination of the center and the intermediate layer has an Atti compression of 60 or greater.
12 . The golf ball of claim 11 , wherein the compression of the combination of the center and the intermediate layer is 80 or greater.
13 . The golf ball of claim 11 , wherein the first intermediate layer has a hardness of about 40 Shore D to about 70 Shore D.
14 . The golf ball of claim 11 , wherein the core has a diameter of 1.40 inches or less.
15 . The golf ball of claim 11 , wherein the core has an Atti compression of 60 or less.
16 . The golf ball of claim 11 , wherein the first intermediate layer has a flexural modulus of 50,000 psi or greater.
17 . The golf ball of claim 11 , wherein the cover is injection molded, cast, reaction injection molded, or compression molded over the core.
18 . The golf ball of claim 11 , wherein the core comprises an inner core layer and an outer core layer.
19 . The golf ball of claim 11 , wherein the golf ball further comprises a second intermediate layer disposed between the core and the first intermediate layer or the cover and the first intermediate layer.
20 . The golf ball of claim 19 , wherein the second intermediate layer comprises an ionomeric composition.