THERMOPLASTIC DUAL CORE HAVING A POSITIVE GRADIENT INNER CORE AND A NEGATIVE GRADIENT OUTER CORE

摘要

A golf ball includes an inner core layer formed from a first thermoplastic material and having a geometric center hardness less than a surface hardness to define a positive hardness gradient. An outer core layer is disposed about the inner core and is formed from a second thermoplastic material. The outer core layer has a surface hardness less than a hardness at a point about 0.5 to 2 mm from an interface between the inner core layer and the outer core layer to define a negative hardness gradient. An inner cover layer is disposed outer core layer and an outer cover layer is disposed about the inner cover layer. The positive hardness gradient os the inner core layer is up to about 10 Shore C and the negative hardness gradient of the outer core layer is less than about 10 Shore C.

主权项

1. A golf ball comprising:
an inner core layer comprising a first thermoplastic material and having a geometric center hardness less than a surface hardness to define a positive hardness gradient; an outer core layer disposed about the inner core, the outer core layer comprising a second thermoplastic material and having a surface hardness less than a hardness at a point about 0.5 to 2 mm from an interface between the inner core layer and the outer core layer to define a negative hardness gradient; an inner cover layer disposed outer core layer; and an outer cover layer disposed about the inner cover layer, wherein the positive hardness gradient is up to about 10 Shore C and the negative hardness gradient is less than about 10 Shore C.