Golf ball with vapor barrier layer and method of making same

1. A golf ball comprising a cover layer encasing a subassembly, the subassembly comprising a moisture vapor barrier layer encasing a core, wherein the moisture vapor barrier layer has a moisture vapor transmission rate of less than about 0.6 grams·mm/m 2 ·day, and is formed from a composition comprising an elastomer and a double-bond vulcanizable rubber, and a thickness of less than 0.01 inch, wherein the composition is cured by infra red radiation or a combination of infra red and ultra violet radiations, wherein the elastomer comprises branched styrenic blocks.

2. The golf ball of claim 1 , wherein the elastomer is halogenated, sulfonated, or both.

3. The golf ball of claim 2 , wherein the elastomer is halogenated, and comprises at least one of the following:

less than about 3% reactive halogen;

less than about 1 halogen atom per double bond; or

a benzylic bromine functionality.

4. The golf ball of claim 1 , wherein the elastomer comprises a conjugated multi-olefin or an iso-olefin.

5. The golf ball of claim 1 , wherein the elastomer is a copolyomer of p-methylstyrene and isobutylene or a brominated copolymer of p-methylstyrene and isobutylene.

6. The golf ball of claim 1 , wherein the composition further comprises a filler.

7. The golf ball of claim 6 , wherein the filler is selected from a group consisting of leafing aluminum, mica flakes, micaceous iron oxide flakes, aluminum flakes, ceramic flakes, graphite flakes, and mixtures thereof.

8. The golf bail of claim 1 , wherein the composition further comprises at least one polymer selected from a group consisting of vinylidene chloride polymers and ionomers.

9. The golf ball of claim 1 , wherein the composition has a moisture vapor transmission rate of about 0.001 grams·mm/m 2 ·day to about 0.1 grams·mm/m 2 ·day.

10. The golf ball of claim 1 , wherein the composition is a dynamically vulcanizable thermoplastic elastomer blend adhesive to diene rubbers.

11. The golf ball of claim 1 , wherein the elastomer has a molecular weight of about 20,000 to about 500,000.

12. The golf ball of claim 1 , wherein the composition forms a tortuous path against moisture vapor encroachment.

13. The golf ball of claim 1 , wherein the composition is applied in a form selected from a group consisting of liquid, latex, viscous liquid, semi-solid, solid, and in solvents.