Patent ID: 7927526

Claim:
A golf ball comprising: a core consisting essentially of a thermoplastic material, the core having an outer diameter of 1.51 inches to 1.59 inches and having an outer surface and a geometric center, each having a hardness; an outer cover layer; and an inner cover layer disposed between the core and the outer cover layer; wherein the thermoplastic core has been exposed to a gradient-initiating solution comprising a silane having the formula: where R′ is a non-hydrolysable organofunctional group, X is a hydrolysable group, and n is 0-24, such that the hardness of the outer surface is greater than the hardness of the geometric center to define a positive hardness gradient of 5 Shore C or greater; wherein the thermoplastic material comprises an ionomer, a highly-neutralized ionomer, a thermoplastic polyurethane, a thermoplastic polyurea, a polyester amide, or a polyester ether.