Nanocomposite ethylene copolymer compositions for golf balls

1. A method for making a golf ball comprising the steps of:

providing a core;

providing a nanoparticulate;

providing a first monomer comprising an olefin;

providing a second monomer comprising an α,β-ethylenically unsaturated carboxylic acid;

in-situ polymerizing the first monomer and the second monomer in the presence of the nanoparticulate to form a nanocomposite non-ionic co-polymer, the nanoparticulate consisting essentially of carbon nanotubes; fullerenes; single-wall and multi-wall carbon nanotubes; carbon nanofibrils; glass ionomers; resin-modified glass ionomers; silicon ionomers; lipid-based nanotubules, graphite sheets, or polyhedral oligomeric silsequioxanes;

forming an inner cover layer about the core from the nanocomposite non-ionic polymer; and

forming an outer cover layer over the inner cover layer, the outer cover comprising a castable urethane or urea material.

2. The method of claim 1 , wherein the first monomer comprises ethylene or propylene.

3. The method of claim 1 , wherein the second monomer comprises acrylic acid or methacrylic acid.

4. The method of claim 1 , wherein the nanoparticulate is pre-dispersed in the second monomer.

5. The method of claim 1 , wherein the nanoparticulate is present in an amount of 0.1 weight % to 10 weight percent of the nanocomposite non-ionomer.

6. The method of claim 1 , wherein the cover has a material hardness of 20 Shore D to 70 Shore D.

7. The method of claim 1 , wherein the cover has a flexural modulus of 5,000 psi to 80,000 psi.

8. The method of claim 1 , wherein the core has a surface hardness of 20 Shore D to 60 Shore D.

9. The method of claim 1 , wherein the core has an elastic modulus of 1,000 psi to 15,000 psi.

10. The method of claim 1 , wherein the cover further comprises a density-adjusting filler.

11. The method of claim 1 , wherein the core is solid, fluid-filled, or hollow.