Golf ball cover composition
A durable, injection moldable, thermoplastic elastomer that has the favorable resilience, feel, spin, barrier, and UV stability performance attributes is disclosed herein. An OBC grafted with silane provides a good cover shear durability (cut/tear/abrasion resistance). This invention combines the benefits of OBCs and silane crosslinking technology to yield a golf ball cover with a desirable combination of properties.
1. A method for forming a golf ball cover, the method comprising:
forming free radicals from a peroxide material;
grafting a vinyl-silane onto an ethylene-octene block copolymer material to form a silane grafted ethylene-octene block copolymer material, wherein grafting comprises compounding the vinyl-silane, the ethylene-octene block copolymer material and free radicals in a twin screw extruder;
dry-blending the silane grafted ethylene-octene block copolymer material with a tin catalyst masterbatch to create a cover composition material;
injection molding the cover composition material onto a golf ball insert assembly to create a covered golf ball; and
moisture curing the covered golf ball in a hot water bath to impart crosslinking through water in combination with the tin catalyst and heat hydrolyzes a plurality of alkoxysilane moieties on the silane grafted ethylene-octene block copolymer that in turn condenses to form siloxane crosslinks in the cover composition material.
2. The method according to claim 1 wherein the golf ball insert assembly comprises a core and a mantle layer.
3. The method according to claim 1 wherein the golf ball insert assembly comprises a dual core and a mantle layer.
4. The method according to claim 1 wherein the golf ball insert assembly comprises a core.
5. The method according to claim 1 wherein the golf ball insert assembly comprises a dual core and a mantle layer composed of a HPF material.
6. The method according to claim 1 wherein the golf ball insert assembly comprises a hollow core and a mantle layer.
7. The method according to claim 1 wherein the golf ball insert assembly comprises a liquid-filled core and a mantle layer.
8. The method according to claim 1 wherein the golf ball insert assembly comprises a thread-wound core and a mantle layer.
9. The method according to claim 1 wherein the vinyl-silane is a trimethoxyvinylsilane.