Patent ID: 7429220

Claim:
A golf ball comprising a center, an intermediate layer disposed over the center, and a cover disposed about the intermediate laver, wherein at least one interpenetrating polymer network is present in the cover, wherein the interpenetrating polymer network is formed from a material consisting essentially of a urethane, an epoxy homopolymer or copolymer, a homopolymer or copolymer having backbone or pendant ester groups, a polyimide or copolymer including imide groups, a polysilane homopolymer or copolymer, a silicone homopolymer or copolymer, a polysiloxane homopolymer or copolymer, and combinations thereof, and wherein the shear resistance rating of the cover is at least 1 rating category lower than that measured for a cover comprising a polymer blend or mixture that is substantially free of IPN and that is made of the same components as the IPN, and wherein at least one of the center, the intermediate layer, and the cover has a foamed structure.