Golf balls having core layers with individual hardness gradients
AssigneeAcushnet Company
InventorsErin McDermott, Manjari Kuntimaddi, Dennis Britton
Life of this patent
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Abstract
Golf balls having core layers with individual hardness gradients are provided. The cores have at least one layer with an increased “positive” hardness gradient (or a “hard-to-soft” hardness) where the outer surface of the core is harder than the center. The increased positive hardness gradient can be achieved by introducing a water-releasing agent into the core rubber formulation during the curing process. The cores may also have a “zero” hardness gradient in another layer. By utilizing different hardness gradients in the core layers, the present disclosure allows for the properties of the final golf ball to be manipulated to produce desired performance characteristics.
Claims20
A core for a golf ball, comprising:
- an outer surface and a geometric center, wherein the core is formed from a reaction product of a base rubber, an organic peroxide, and a metal sulfate hydrate comprising aluminum sulfate monohydrate and at least one of calcium sulfate dihydrate or zinc sulfate heptahydrate,
- wherein the geometric center and the outer surface each has a hardness, and the hardness of the outer surface is greater than the hardness of the geometric center to define a positive hardness gradient of at least 30 Shore C units.
A dual core for a golf ball, comprising:
- a first core layer disposed over a second core layer,
- wherein the first core layer is formed from a reaction product comprising a base rubber, an organic peroxide, and a metal sulfate hydrate comprising aluminum sulfate monohydrate and at least one of calcium sulfate dihydrate or zinc sulfate heptahydrate, and the first core layer has an inner surface hardness less than an outer surface hardness to define a positive hardness gradient of at least 30 Shore C units.
A multi-layered core for a golf ball, comprising:
- a center and a plurality of core layers formed around the center,
- wherein at least one of the center or the plurality of core layers has a positive hardness gradient of at least 30 Shore C units and is formed from a reaction product of a base rubber, an organic peroxide, and a metal sulfate hydrate comprising aluminum sulfate monohydrate, calcium sulfate dihydrate, and zinc sulfate heptahydrate.
Dependencies are inferred from the claim text.