| 摘要 |
A multi-layered core golf ball wherein each core layer comprises its own specific hardness gradient in addition to an overall specific hardness gradient from one core layer to the next. The inner core layer comprises a plurality of hardnesses of from about 40 Shore C to about 85 Shore C, a diameter of about 30 mm or lower, and a first outer surface comprising a hardness greater than a hardness of a geometric center to define a positive hardness gradient of about 20 Shore C or greater. The outer core layer comprises a plurality of hardnesses of from about 65 Shore C to about 95 Shore C, a thickness of about 10 mm or lower, and a second outer surface comprising a hardness greater than that of an inner surface to define a positive hardness gradient of about 20 Shore C or lower. A further outer core layer hardness, disposed in a region extending between about 10% and about 90% of the distance from the inner surface to the second outer surface, is greater than that of the inner and second outer surfaces. Also, the hardness of second outer surface is greater than that of the geometric center to define a positive hardness gradient of about 30 Shore C or greater.
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