| abstract |
Multi-layered golf balls containing a dual-core structure are provided. The core structure includes an inner core (center) comprising a thermoplastic composition, preferably including: a) ethylene acid copolymer, b) plasticizer, and c) cation source. Preferably, a fatty acid ester such as ethyl oleate is used as the plasticizer. The outer core layer is preferably formed from a thermoset composition such as polybutadiene rubber. The core layers have different hardness levels. The core assembly preferably has a positive hardness gradient extending across the entire assembly. The core structure and resulting ball have relatively good resiliency at given compressions. |