Patent ID: 6893359

Claim:
A method for preparing a solid golf ball, comprising the steps of: placing a solid core formed from a rubber composition in a mold composed of upper and lower mold halves; injection molding a cover material mainly containing a thermoplastic urethane resin around the surface of said solid core so as to directly cover the solid core, wherein in said mold, assuming that a parting plane of said upper and lower mold halves is taken as an equator, each of said upper and lower mold halves has air vent portions in a region within a radius of 10 mm, measured as that projected on the equator plane, from a pole of said mold half, and the total length of gaps of said air vent portions formed in said upper and lower mold halves is in a range of 90 mm or more, the width of each of the gaps of said air vent portions is in a range of 0.01 to 0.08 mm, and the total area, measured as that projected on the equator plane, of the gaps of said air vent portions in said upper and lower mold halves is in a range of 1 to 5 mm 2 , thereby to prepare the solid golf ball wherein said solid core has a hardness, expressed by a deflection measured under an applied load of 5 kg to 130 kg, in a range of 2.0 mm or more, and said urethane cover has a thickness in a range of 0.9 mm to 1.7 mm.