US Patent 7,775,908
Golf balls having two core layers formed from HNP compositions
Abstract
The present invention is directed to golf balls consisting of a dual-layer core and a cover. The core consists of a layer formed from a relatively soft HNP composition and a layer formed from a relatively hard HNP composition. The relatively soft HNP composition has a material hardness of 55 Shore D or less and comprises a highly neutralized ethylene/(meth)acrylic acid/alkyl (meth)acrylate copolymer. The relatively hard HNP composition has a material hardness of 45 Shore D or greater and comprises a highly neutralized ethylene/(meth)acrylic acid copolymer. The cover preferably consists of a single cover layer.