Multi-layer golf ball with a thin, castable outer layer

1. A golf ball comprising:

a core;

an intermediate layer formed from a polymer blend having a flexural modulus of between about 65,000 psi and about 120,000 psi comprising a first material and a second material comprising a grafted-metallocene polymer; and

a cover layer comprising a castable reactive liquid material.

2. The golf ball of claim 1 , wherein the grafted metallocene polymer is formed from homopolymers and copolymers of ethylene; and a second olefin comprising propylene, butene, pentene, hexene, heptene, octene, and norbornene.

3. The golf ball of claim 1 , wherein the grafted metallocene polymer is produced by grafting a functional group onto a metallocene-catalyzed polymer having the formula:

wherein:

R 1 is hydrogen, branched or straight chain alkyl methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, and octyl, carbocyclic, aromatic or heterocyclic;

R 2 is hydrogen, lower alkyl selected from the group consisting of C 1 –C 5; carbocyclic, aromatic and heterocyclic;

R 3 is hydrogen, lower alkyl selected from the group consisting of C 1 –C 5, carbocyclic, aromatic and heterocyclic;

R 4 is selected from the group consisting of H, C n H 2n+1, where n=1 to 18, and phenyl, in which from 0 to 5 H within R 4 can be replaced by substituents selected from the group consisting of COOH, SO 3 H, NH 2, F, Cl, Br, I, OH, SH, silicone, lower alkyl esters and lower alkyl ethers, with the proviso that R 3 and R 4 can be combined to form a bicyclic ring;

R 5 is hydrogen, lower alkyl C 1 –C 5 , carbocyclic, aromatic or heterocyclic;

R 6 is hydrogen, lower alkyl C 1 –C 5 , carbocyclic, aromatic or heterocyclic; and

wherein x ranges from 1–99 percent, y ranges from 99–1 percent, and z ranges from 0 to 49 percent.

4. The golf ball of claim 1 , wherein the castable reactive liquid material comprises thermoset or thermoplastic polyurethanes, polyureas, urethane ionomers, urethane epoxies, or a mixture thereof.

5. The golf ball of claim 1 , wherein the grafted metallocene polymer is functionalized by sulfonation, carboxylation, the addition of an amine or hydroxy group, or a mixture thereof.

6. The golf ball of claim 1 , wherein the grafted metallocene polymer is a maleic anhydride grafted metallocene polymer.

7. The golf ball of claim 1 , wherein the grafted-metallocene polymer is foamed or unfoamed.

8. The golf ball of claim 1 , wherein the polymer blend further comprises a non-ionomer.

9. The golf ball of claim 1 , wherein the intermediate layer has an outer diameter of between about 1.58 and about 1.64 inches.

10. The golf ball of claim 1 , wherein the outer cover has a Shore D hardness of between about 30 and about 60.

11. The golf ball of claim 1 , wherein the intermediate layer has a Shore D hardness of about 65 to about 80.

12. The golf ball of claim 1 , wherein the intermediate layer has a thickness of no greater than about 0.055 inches.

13. The golf ball of claim 1 , wherein the outer cover layer has a thickness of less than about 0.05 inches.