Patent ID: 8821316

Claim:
A golf ball, comprising a solid, single core having an outer surface and a geometric center, the core being formed from a rubber composition, the rubber composition comprising a cycloalkene rubber having a trans-bond content of 55% or greater and a melting point of 30° C. or greater in an amount of 80 weight percent and polybutadiene rubber having a cis-bond content of at least 40% in an amount of 20 weight percent, and zinc diacrylate in an amount of 40 phr or greater and peroxide in an amount of 2.5 phr or greater based on weight of the cycloalkene rubber, wherein the geometric center and the outer surface each has a hardness, the hardness of the outer surface being in the range of 42 Shore C to 60 Shore C and the hardness of the geometric center being in the range of 52 Shore C to 65 Shore C to define a zero or negative hardness gradient, wherein the gradient is in the range of 0 to 10 Shore C units; and a cover layer surrounding the core.