Game balls with cover containing post crosslinkable thermoplastic polyurethane and method of making same

1. A golf ball, comprising:

a core, and

a cover layer formed over said core, said cover layer comprising a crosslinkable thermoplastic polyurethane and a co-agent capable of crosslinking said crosslinkable thermoplastic polyurethane via free radical initiation, the co-agent having the formula H 2 C═CH—(CH 2 ) n —CH═CH 2 where n is from 1 to 6.

2. The golf ball according to claim 1 , wherein said crosslinkable thermoplastic polyurethane has a Shore D hardness of from about 35 to about 72 before crosslinking and undergoes an increase in Shore D hardness of at least 2 units upon exposure to gamma radiation at a dosage of 3.5 Mrads.

3. The golf ball according to claim 1 , wherein said crosslinkable thermoplastic polyurethane has a Shore D hardness of from about 35 to about 72 before crosslinking and experiences an increase in Shore D hardness of at least 5 units upon exposure to gamma radiation at a dosage of 3.5 Mrads.

4. The golf ball according to claim 1 , wherein said crosslinkable thermoplastic polyurethane comprises at least one of a polyether based polyurethane and a polyester based polyurethane.

5. The golf ball according to claim 1 , wherein said core is at least one member selected from the group consisting of solid cores, wound cores and liquid filled cores.

6. A golf ball comprising:

a core; and

a cover layer disposed about said core, said cover comprising a thermoplastic polyurethane capable of undergoing crosslinking upon exposure to about 3.5 Mrads of radiation, and thereby increasing in hardness by at least 2 units on the Shore D hardness scale, wherein said cover layer further comprises a co-agent capable of crosslinking said thermoplastic polyurethane, the a co-agent having the formula H 2 C═CH—(CH 2 ) n —CH═CH 2 where n is from 1 to 6.

7. The golf ball according to claim 6 , wherein said cover layer comprises at least an inner cover layer and an outer cover layer.