DUAL-CORE COMPRISING ZERO GRADIENT CENTER AND POSITIVE GRADIENT OUTER CORE LAYER

摘要

Disclosed is a golf ball including an internal core which is formed of a homogeneous first rubber composite including a carbon-carbon initiator and has a geometric center and a first outer surface having a hardness about 20 shore C lower than the hardness of the geometric center; an external core layer including a second outer surface which is formed of a homogeneous second rubber composite and has a hardness about 43 shore C point higher than the hardness of the geometric center; an internal cover layer which includes an ionomer material and has a material hardness of about 55 shore D or more and is arranged around the core; and an external cover layer which includes polyurea or polyurethane and has a material hardness of 20 shore D to 70 shore D and is arranged around the internal cover layer.