A golf ball comprising a thermoplastic inner core layer that has a geometric center hardness greater than its surface hardness to define a first “negative” hardness gradient. An outer core layer is disposed about the inner core and is formed from a substantially homogenous thermoset composition,...http://www.google.es/patents/US7942761?utm_source=gb-gplus-sharePatente US7942761 - Dual core golf ball having negative-hardness-gradient thermoplastic inner core and shallow negative-hardness-gradient outer core layer
Dual core golf ball having negative-hardness-gradient thermoplastic inner ...
