Golf ball layer having reduced surface hardness and method of making same

Abstract

A golf ball comprising a core and a cover, wherein the core comprises a thermoset rubber composition, a geometric center and a treated outer surface, the treated outer surface having a first hardness and the geometric center having a second hardness, the treated outer surface being treated with a surface-softening material comprising at least one fatty acid and/or fatty acid salt plasticizer composition such that the second hardness is greater than the first hardness to define a negative hardness gradient. In another emobodiment, the golf ball comprises a thermoset rubber composition core and a cover, said core comprising a treated outer surface and a geometric center, the treated outer surface comprising a fatty acid and/or fatty acid salt plasticizer composition and extending inward from the surface from about 0.001 inches to about 0.100 inches, the treated outer surface further having a first hardness and the geometric center having a second hardness, wherein the first hardness is less than the second hardness to define a negative hardness gradient.

Dependencies are inferred from the claim text.