| 摘要 |
PROBLEM TO BE SOLVED: To provide golf balls capable of achieving a high initial ball velocity using foam cores.SOLUTION: A core 17 includes a foam inner core 18 (center), an intermediate core layer 20 and an outer core layer 22. Foamed polyurethane is preferably used to make the inner core 18. The intermediate core layer 20 and the outer core layer 22 are preferably made of non-foamed thermoplastic compositions such as ethylene acid copolymer ionomers. In an alternative version, the intermediate core layer 20 is made of a thermoset composition such as polybutadiene. The core layers have different hardness and specific gravity levels. |
