Patent ID: 8394876

Claim:
A golf ball comprising a core, one or more intermediate layer and an outermost cover layer, wherein at least one intermediate layer is formed of a resin composition which is comprised of: (a) a nonionic olefin-unsaturated carboxylic acid copolymer having a weight-average molecular weight (Mw) of from 40,000 to 73,400, a weight-average molecular weight (Mw)/number-average molecular weight (Mn) ratio of from 2.0 to 10.0 and an unsaturated carboxylic acid content of at least 16 wt %, (b) a nonionic olefin-unsaturated carboxylic acid copolymer and/or olefin-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer having a weight-average molecular weight (Mw) of from 40,000 to 200,000, a weight-average molecular weight (Mw)/number-average molecular weight (Mn) ratio of from 4.0 to 10.0 and an unsaturated carboxylic acid content of less than 16 wt %, (c) an organic acid or a metal salt thereof, and (d) a basic inorganic metal compound for neutralizing at least 70 mol % of acid groups in components (a) to (c), and which has a material hardness, expressed as the Shore D hardness, of from 40 to 60; and wherein the cover is formed of an ionic resin composition which is comprised of: (A) an ionic olefin-unsaturated carboxylic acid copolymer having a weight-average molecular weight (Mw) of from 40,000 to 150,000, a weight-average molecular weight (Mw)/number-average molecular weight (Mn) ratio of from 4.0 to 10.0 and an unsaturated carboxylic acid content of at least 16 wt %, and/or (B) an ionic olefin-unsaturated carboxylic acid copolymer and/or olefin-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer having a weight-average molecular weight (Mw) of from 40,000 to 200,000, a weight-average molecular weight (Mw)/number-average molecular weight (Mn) of from 4.0 to 10.0 and an unsaturated carboxylic acid content of less than16 wt %, and which has a material hardness, expressed as the Shore D hardness, of at least 55, wherein the cover comprises component (B).