Compositions for golf balls based on oriented nanostructures
Multi-piece golf balls having at least one component made of a rubber composition comprising substantially oriented nanostructures are provided. For example, the nanostructures may be in the form of nanofibers, nanorods, nanotubes, and nanoparticles. The multi-piece golf ball contains a core, which may have a dual-core construction including a center and surrounding outer core layer or other multi-layered structure. Preferably at least one of the core layers is formed from a polybutadiene rubber composition comprising the nanostructures. The polybutadiene rubber may be chemically or non-chemically modified. The polybutadiene preferably has a cis-bond content of at least 80%.
1. A golf ball, comprising a core having at least one layer and a cover having at least one layer, the at least one layer of the core being formed a composition comprising;
i) a rubber material, wherein the rubber material comprises about 5 to about 50% by weight modified polybutadiene rubber and about 50 to about 95% by weight non-modified polybutadiene rubber;
ii) 0.1 to 5 parts by peroxide free-radical initiator;
iii) 5 to 50 parts by weight cross-linking co-agent; and
iv) 0.1 to 30 parts by weight of substantially oriented nanostructures, the nanostructures being selected from the group consisting nanofibers, nanorods, nanotubes, and nanoparticles, based on 100 parts of rubber material.
2. The golf ball of claim 1 , wherein the nanostrnctures are nano-particles having an average particle size of 100 nm or less.
3. The golf ball of claim 1 , wherein the modified polybutadiene rubber is formed by reacting the polybutadiene with a chemical modifier having chemical moieties selected from the group consisting of alkoxysilanes, three-membered heterocycles including oxiranes, azirdines and thioxiranes; carboxylic acids, esters and salts, alcohols, isocyanates, thiols, sulfides, and anhydrides.
4. The golf ball of claim 1 , wherein the modified polybutadiene has a cis-content of at least 80%.
5. The golf ball of claim 4 , wherein the modified polybutadiene has a cis-content of at least 90%.
6. The golf ball of claim 5 , wherein the modified polybutadiene has a cis-content of at least 97%.
7. The golf ball of claim 1 , wherein the cross-linking co-agent is selected from the group consisting of zinc acrylates and zinc methacrylates.
8. The golf ball of claim 1 , wherein the rubber material further comprises 0.5 to 100 parts by weight of a non-nanometer-sized filler material.
9. The golf ball of claim 8 , wherein the filler is selected from the group consisting of silica, clay, glass fibers, aramid fibers, mica, calcium metasilicate, zinc sulfate, zinc sulfide, barium sulfate, and carbon black and mixtures thereof.
10. The golf ball of claim 8 , wherein the filler is selected from the group consisting of calcium carbonate, zinc carbonate, barium carbonate, and magnesium carbonate, and mixtures thereof.
11. The golf ball of claim 8 , wherein the filler is selected from the group consisting of titanium., tungsten, aluminum, bismuth, nickel, molybdenium, iron, lead, copper, boron, cobalt, beryllium, zinc, tin, steel, brass, bronze, boron carbide, and tungsten carbide materials.
12. The golf ball of claim 8 , wherein the filler is selected from the group consisting of zinc oxide, tin oxide, iron oxide, calcium oxide, aluminum oxide, and mixtures thereof.
13. The golf ball of claim 1 , wherein the composition further comprises a halogenated organosulfur or metal salt thereof, an organic disulfide, or an inorganic disulfide compound.
14. The golf ball of claim 1 , wherein the composition for the core layer further comprises a polymer selected from the group consisting of ethylene acid copolymer ionomers; polyesters; polyamides; polyamide-ethers, polyimide-esters; polyurethanes, polyureas;
fluoropolymers; polystyrenes; polypropylenes and polyethylenes; polyvinyl chlorides; polyvinyl acetates; polycarbonates; polyvinyl alcohols; polyethers; polyimides, polyetherketones, polyamideimides; and mixtures thereof.
15. The golf ball of claim 1 , wherein the cover is a single layer having a thickness of about 0.015 to about 0.090 inches and is formed from a thermoplastic or thermoset material.
16. The golf ball of claim 1 , wherein the cover comprises two or more layers and has an overall thickness of about 0.020 to about 0.210 inches and wherein each cover layer is formed from a thermoplastic or thermoset material.
17. The golf ball of claim 16 , wherein the inner cover is formed of an ionomer resin comprising an ethylene acid copolymer and the outer cover is formed of a polyurethane composition.