GOLF BALLS HAVING FOAM CENTER AND THERMOSET OUTER CORE LAYER WITH HARDNESS GRADIENTS

摘要

Multi-layered golf balls containing a dual-core structure are provided. The core structure includes an inner core (center) comprising a foam composition, preferably foamed polyurethane. The outer core layer is preferably formed from a non-foamed thermoset composition such as polybutadiene rubber. The core layers have different hardness and specific gravity levels. The specific gravity (density) of the foam inner core is preferably less than the density of the outer core layer. The core assembly preferably has a positive hardness gradient extending across the entire assembly. The core structure and resulting ball have relatively good resiliency.

主权项

1. A core assembly for a golf ball, comprising:
i) an inner core layer comprising a foamed composition, the inner core layer having a diameter in the range of about 0.100 to about 1.100 inches, a specific gravity (SGinner), and an outer surface hardness (Hinner core surface) and a center hardness (Hinner core center), the Hinner core surface being greater than the Hinner core center to provide a positive hardness gradient; and ii) an outer core layer comprising a thermoset material, the outer core layer being disposed about the intermediate core layer and having a thickness in the range of about 0.100 to about 0.750 inches, a specific gravity (SGouter), and an outer surface hardness (Houter surface of OC) and an inner surface hardness (Hinner surface of OC), the Houter surface of OC being greater than the Hinner surface of OC to provide a positive hardness gradient, wherein the SGouter, is greater than the SGinner, and the center hardness of the inner core (Hinner core center) is in the range of about 10 Shore C to about 60 Shore C and the outer surface hardness of the outer core layer (Houter surface of OC) is in the range of about 65 Shore C to about 96 Shore C to provide a positive hardness gradient across the core assembly.