| abstract |
A multi-piece solid golf ball having a core, an envelope layer, an intermediate layer and a cover. The core is formed primarily of a thermoplastic resin and has a diameter of from 20 to 30 mm, the envelope layer is formed of a rubber composition containing primarily a rubber material and has a thickness of from 3 to 10 mm, the intermediate layer is formed of a resin composition containing primarily an ionomer, and the cover is formed of a resin composition containing primarily a urethane. Both the relationship among the specific gravities of the core, the envelope layer and the intermediate layer, and the relationship among the surface hardnesses of the core, the envelope layer, the intermediate layer and the cover are optimized. |