Patent ID: 8414426
Filing Date: 2013-04-09
Classification: A63B

Abstract:
1. A golf ball comprising: a unitary core having a volume, an outer surface, a geometric center, and an outermost transition volume adjacent to the outer surface, the core being formed from a substantially homogenous composition; an inner cover layer; and an outer cover layer comprising ionomer, metallocene-catalyzed polymer, polyester, polyamide, non-ionomeric thermoplastic elastomer, copolyether-ester, copolyether-amide, polycarbonate, polybutadiene, polyisoprene, or polystyrene block copolymer; wherein the outermost transition volume is disposed between the core outer surface and the geometric center, the transition volume has an outer portion congruent with the core outer surface, and comprises the outermost 5% to 40% of the core volume; wherein the core has an outer diameter of 1.0 to 1.64 inches and the transition volume has an inner portion and the hardness within the transition volume decreases by at least 2 Shore C/mm in a direction away from the inner portion and towards the outer portion; and wherein both a hardness of the core outer surface and a hardness within the outermost transition volume are less than the hardness of the geometric center to define a negative hardness gradient.