Patent ID: 8764582

Claim:
A multi-piece solid golf ball, comprising a solid core, an envelope layer that encloses the solid core, an intermediate layer that encloses the envelope layer, and a cover that encloses the intermediate layer and has a plurality of dimples on a surface thereof, wherein the solid core has a diameter of 36.3 to 41.0 mm, a center hardness expressed as the Shore D hardness of 15 to 45, a surface hardness expressed as the Shore D hardness of 40 to 63, and a hardness difference between the center and surface, expressed in Shore D hardness units, of 10 to 40; the envelope layer is made primarily of a resin, has a thickness of 0.2 to 0.9 mm and the material of which it is made has a Shore D hardness of 45 to 58; the intermediate layer has a thickness of 0.5 to 1.5 mm, the material of which it is made has a Shore D hardness of 55 to 75, and the intermediate layer is formed so as to be harder than the envelope layer and the cover; the cover has a thickness of 0.6 to 1.5 mm and the material of which it is made has a Shore D hardness of 30 to 60; the cover material and the intermediate layer material have a Shore D hardness difference therebetween of 2 to 30; and the combined thickness of the envelope layer, intermediate layer and cover is from 1.5 to 3.5 mm, wherein the material of which the intermediate layer is made includes trimethylolpropane or polyhydroxypolyolefin oligomers.