Golf ball compositions
View Patent ↗Disclosed herein are heterogeneous golf ball compositions comprising discrete particles of crosslinked rubber dispersed within an acid copolymer-based matrix.
1. A golf ball comprising an innermost core layer formed from a heterogeneous composition, the heterogeneous composition comprising:
a thermoplastic matrix formed from an acid copolymer composition wherein the acid copolymer is selected from one or more E/X- and E/X/Y-type acid copolymers of ethylene, an α,β-unsaturated carboxylic acid, and optionally a softening comonomer, and
discrete particles of crosslinked rubber dispersed within the matrix,
wherein the discrete particles are present in an amount of from 10 wt % to 40 wt %, based on the total weight of the heterogenous composition, and are formed from a rubber composition that is substantially free of reactive metal ingredients, and
wherein less than 5% of all acid groups present in the matrix composition are neutralized.
2. The golf ball of claim 1 , wherein less than 3% of all acid groups present in the matrix composition are neutralized.
3. The golf ball of claim 1 , wherein less than 1% of all acid groups present in the matrix composition are neutralized.
4. The golf ball of claim 1 , wherein the crosslinked rubber composition has a Shore D hardness of 60 or greater.
5. The golf ball of claim 1 , wherein the crosslinked rubber composition has a Shore D hardness of 65 or greater.
6. The golf ball of claim 1 , wherein the acid copolymer is ethylene acrylic acid.
7. The golf ball of claim 1 , wherein the discrete particles have a particle size of from 1.19 mm to 2.38 mm.