| 摘要 |
Golf balls comprise a core and a cover for said core formed from a composition comprising a copolymer of at least one mono-olefin and at least one unsaturated mono- or di-carboxylic acid. The copolymers may be derived from ethylene and acrylic, methacrylic, itaconic, crotonic or sorbic acid. The copolymers may also comprise units of metal salts of such acids, e.g. sodium or zinc salts, to provide thermolabile cross-linkages; and units of other monomers such as vinyl alkanoates, alkyl acrylates and alkyl methacrylates. The copolymer may be a random copolymer, or a radiation induced graft polymer of the acid on a polyolefin base. Instead of using an acid salt monomer a cross-linking agent which supplies metal ions, e.g. a metal acetate, oxide, carbonate or hydroxide, may be incorporated. Fillers, e.g. metal oxides, may also be present. In examples golf ball covers are prepared from compositions comprising (I) ethylene/acrylic acid copolymers and titanium dioxide, with and without zinc oxide; (II) ethylene/acrylic acid/sodium acrylate copolymers and titanium dioxide, with and without zinc oxide; (III) a polyethylene/acrylic acid graft copolymer, with and without zinc oxide; and (IV) an ethylene/methacrylic acid/sodium methacrylate copolymer, or ethylene/acrylic acid copolymers reacted with sodium acetate, and titanium dioxide.ALSO:Golf balls comprise a core and a cover for said core formed from a composition comprising a copolymer of at least one mono olefin and at least one unsaturated mono- or dicarboxylic acid. The copolymers may be derived from ethylene and acrylic, methacrylic, itaconic, crotonic or sorbic acid. The copolymers may also comprise units of metal salts of such acids, e.g. sodium or zinc salts, to provide thermo-labile cross-linkages; and units of other monomers such as vinyl alkanoates, alkyl acrylates and alkyl methacrylates. Instead of using an acid salt monomer a cross-linking agent which supplies metal ions, e.g. a metal acetate, oxide, carbonate or hydroxide, may be incorporated in the copolymer. Fillers, e.g. metal oxides, may also be present. The balls may be manufactured by moulding the compositions of the invention to form half shells, placing two half shells round a core comprising a core-centre which is solid or a liquid or paste filled spherical sac wound with rubber tape or thread, heating the assembly in a mould to fuse the two half shells on the core and impart the desired surface pattern thereto. In examples golf balls are prepared from thread-wound cores and cover compositions comprising (I) ethylene/acrylic acid copolymers and titanium dioxide with and without zinc oxide; (II) ethylene/acrylic acid/sodium acrylate copolymers and titanium dioxide with and without zinc oxide; (III) a polyethylene/acrylic acid graft copolymer with and without zinc oxide; and (IV) an ethylene/methacrylic acid/sodium methacrylate copolymer, or ethylene/acrylic acid copolymers reacted with sodium acetate, and titanium dioxide. |
