High hardness gradient golf ball cores and methods of making same
AssigneeAcushnet Company
InventorsErin McDermott, Manjari Kuntimaddi
Life of this patent
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Abstract
Compositions including a water releasing agent and golf ball cores made from such compositions having a high hardness gradient are disclosed. The type and concentration of the components in the composition, including the water releasing agent, affect the hardness and hardness gradient of cores made from the composition and, thus, can be used to produce a golf ball having desirable performance characteristics. Cores made from the composition may be cured using infrared radiation to further increase the hardness and hardness gradient of such cores. Cores cured using infrared radiation may have a center and a skin with hardness greater than the hardness of the center to produce a high hardness gradient.
Claims19
A golf ball, comprising:
- a core having a center and a skin disposed about the center, wherein the core is formed from a rubber formulation cured under infrared radiation, the rubber formulation comprising:
- a base rubber, and
- a water releasing agent comprising a metal salt hydrate, wherein the water releasing agent has 1 to 4 waters of hydration and is present in an amount of about 0.7 to about 1.4 parts by weight per 100 parts of the base rubber;
- and
- a cover layer disposed about the core, wherein the center has a hardness ranging from about 45 Shore C to about 65 Shore C, wherein the skin has a hardness ranging from about 60 Shore C to about 95 Shore C, wherein the core possesses a hardness gradient substantially equal to the difference in the center hardness and the skin hardness, and wherein the hardness gradient is at least 30 Shore C.
A golf ball, comprising:
- a multi-layer core comprising a center and an outer core layer disposed about the center, the outer core layer having a skin forming an exterior of the outer core layer,
- wherein the outer core layer is formed from a rubber formulation cured under infrared radiation, the rubber formulation comprising:
- a base rubber, and
- a water releasing agent comprising a metal salt hydrate, wherein the water releasing agent has 1 to 4 waters of hydration and is present in an amount of about 0.7 to about 1.4 parts by weight per 100 parts of the base rubber;
- and
- a cover layer disposed about the core, wherein the center has a hardness ranging from about 45 Shore C to about 65 Shore C, wherein the skin has a hardness ranging from about 70 Shore C to about 95 Shore C, wherein the core possesses a hardness gradient substantially equal to the difference in the center hardness and the skin hardness, and wherein the hardness gradient is at least 30 Shore C.
A golf ball, comprising:
- a core comprising:
- a center having a geometric center hardness HC ranging from about 45 Shore C to about 65 Shore C;
- a skin disposed about the center and including a surface having a surface hardness HS ranging from about 60 Shore C to about 95 Shore C;
- and
- a hardness gradient HGr equal to the difference between HC and HS,
- wherein the core is formed from a rubber formulation comprising a base rubber and a metal salt hydrate having a water releasing agent concentration WRAC ranging from about 0.7 parts to about 1.4 parts by weight per 100 parts of the base rubber, and waters of hydration, WRAWOH ranging between 1 and 4,
- wherein HGr is equal to or greater than 30 Shore C,
- wherein HS is at least 2 Shore C harder than any point in the center,
- and wherein
- 1
- ≤
- WRA
- C
- *
- WRA
- WOH
- 1
- -
- 1
- H
- Gr
- ≤
- 22
- ;
- and
- a cover layer disposed about the core.
Dependencies are inferred from the claim text.