US 12,478,840 B2
Golf balls having core layers with individual hardness gradients
Erin McDermott, Providence, RI (US); Manjari Kuntimaddi, Raynham, MA (US); and Dennis Britton, North Dartmouth, MA (US)
Assigned to Acushnet Company, Fairhaven, MA (US)
Filed by Acushnet Company, Fairhaven, MA (US)
Filed on Oct. 18, 2023, as Appl. No. 18/381,245.
Prior Publication US 2025/0128126 A1, Apr. 24, 2025
Int. Cl. A63B 37/06 (2006.01); A63B 37/00 (2006.01); C08K 3/30 (2006.01); C08K 5/14 (2006.01); C08L 9/00 (2006.01)
CPC A63B 37/0063 (2013.01) [A63B 37/0051 (2013.01); C08K 3/30 (2013.01); C08K 5/14 (2013.01); C08L 9/00 (2013.01); C08K 2003/3045 (2013.01); C08L 2205/025 (2013.01); C08L 2205/03 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A golf ball, comprising:
a core having an outer surface and a geometric center, wherein the core is formed from a rubber composition cured under heat, the rubber composition comprising:
a base rubber,
an organic peroxide,
a cross-linking co-agent,
a first water releasing agent and a second water releasing agent, wherein the first water releasing agent is aluminum sulfate monohydrate and the second water releasing agent is selected from calcium sulfate dihydrate or zinc sulfate heptahydrate,
wherein the geometric center and the outer surface each has a hardness and the hardness of the geometric center ranges from about 45 Shore C to about 65 Shore C and the hardness of the outer surface ranges from about 80 Shore C to about 100 Shore C, and
wherein 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; and
a cover layer surrounding the core.