Abstract: The present invention is a composition for making a solid one-piece golf ball and the core of a two-piece or multi-layer golf ball with a butadiene base crosslinked by a methacrylic acid zinc salt. The resulting product is a golf ball with outstanding performance which possesses both resilience and durability and which can be reproduced accurately and economically. This type of golf ball is suitable for play by tournament caliber golfers.

Abstract: In a homogeneous molded golf ball comprising a filled elastomer highly cross-linked into a three dimensional network with long, flexible cross-links formed of a polymerized cross-linking monomer, the improvement which comprises using as said cross-linking monomer a metal-containing cross-linkable monomer whereby said comonomer simultaneously functions as said filler at least in part. The preferred elastomer is cis-polybutadiene. The metal-containing cross-linkable monomer can be formed in situ or added as such and preferably comprises a salt of at least one metal selected from the group consisting of zinc, magnesium and calcium, and at least one acid selected from the group consisting of methacrylic, acrylic, cinnamic, acotinic, crotonic, vinylacetic, itaconic, styrenesulfonic and benzoylacrylic acids. Additional filler may be added to adjust the density to the desired value.