Patent ID: 8486322

Claim:
A method of manufacturing golf balls which is characterized in that a golf ball having a cover layer formed thereon is post-treated for a specific length of time in up to a 150° C. temperature environment and/or a high-humidity environment, wherein the method comprises the steps of premixing a cover resin material comprising (A) a thermoplastic polyurethane, (B) a polyisocyanate compound and (C) a thermoplastic elastomer other than the thermoplastic polyurethane in a weight ratio (A):(B):(C)=100: {2-50}: {0-50} to form single pellets; and injecting the cover resin material in the form of the single resin pellets so as to form a cover layer, wherein the cover resin material is injected with from 10 to 99% of the total number of isocyanate groups in component B remaining in an unreacted state within the cover resin material.