Highly-neutralized thermoplastic copolymer center for improved multi-layer core golf ball
AssigneeAcushnet Company
InventorsMichael J. Sullivan, Derek A. Ladd
Life of this patent
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Abstract
A golf ball includes an inner core layer formed from a first rubber composition having a first Shore D hardness; an intermediate core layer formed from a second rubber composition; and a thermoplastic outer core layer having a second Shore D hardness. The outer core layer includes a copolymer of ethylene and an α,β-unsaturated carboxylic acid, an organic acid or salt thereof, and sufficient cation source to fully-neutralize the acid groups of the copolymer. An inner cover layer surrounds the multi-layer core and an outer cover layer is disposed about the inner cover layer. The inner core layer hardness differs from the outer core hardness by at least 10 points.
Claims11
A golf ball comprising:
- a center formed from a first composition comprising:
- an E/X/Y-type copolymer, wherein E is ethylene, X is an α,β-unsaturated carboxylic acid, and Y is a softening comonomer present in an amount of from 0 wt % to 50 wt % of the polymer;
- and
- a cation source;
- wherein greater than 80% of all acid groups present in the first composition are neutralized;
- a cover;
- and
- an intermediate layer disposed between the center and the cover and formed from a second composition;
- wherein a sphere resulting from a combination of the center and the intermediate layer has a compression of 60 or greater;
- and
- wherein the Shore D hardness of the first composition is less than the Shore D hardness of the second composition.
Dependencies are inferred from the claim text.