Patent ID: 7691010
Filing Date: 2010-04-06
Classification: A63B,C08F,C08L

Abstract:
1. A golf ball which comprises a core, a mid layer and a cover, said mid layer comprising 10 parts by weight or greater and 70 parts by weight or less of a thermoplastic elastomer containing a styrene block having a material hardness of less than 10, and 30 parts by weight or greater and 90 parts by weight or less of an ethylene-(meth)acrylic acid copolymer based ionomer resin having a material hardness of 50 or greater and 70 or less, per 100 parts by weight of the base polymer, wherein said mid layer has a shore D hardness of less than 40, and said mid layer has a thickness of equal to or less than 1.2 mm, said golf ball having three or more kinds of dimples, each having a different diameter, on the surface thereof, an occupation ratio of the total area of the dimples in the surface area of a phantom sphere being equal to or greater than 75%, a ratio Dx/Dn being equal to or greater than 1.30, wherein a mean diameter of the dimples having a diameter ranking in the top 10% of the diameters of all the dimples is defined as Dx and a mean diameter of the dimples having a diameter ranking in the bottom 10% of the diameters of all the dimples is defined as Dn, and a standard deviation η of diameters of all the dimples being equal to or less than 0.52.