Multi-piece solid golf ball

摘要

In 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 elastomer, the envelope layer is formed of a rubber composition containing primarily a rubber material, 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. The relationships among the specific gravities and the surface hardnesses of the respective layers are optimized. This golf ball enables an increased distance on full shots with a driver and improved controllability in the short game to be achieved, and also makes it possible to obtain a further reduction in the spin rate on full shots.

主权项

1. A multi-piece solid golf ball comprising a core, an envelope layer encasing the core, an intermediate layer encasing the envelope layer, and a cover which encases the intermediate layer and has formed on a surface thereof a plurality of dimples,
wherein the core is formed primarily of one or more thermoplastic elastomer selected from the group consisting of polyester, polyamide, polyurethane, olefin and styrene-type thermoplastic elastomers and has a diameter of from 10 to 30 mm, a specific gravity of more than 1.0 and less than 1.3, and a deflection when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf) of from 3.6 to 10 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; wherein the intermediate layer has a specific gravity of less than 1.0; wherein the envelope layer, the intermediate layer and the cover have specific gravities which satisfy the condition:
envelope layer specific gravity>intermediate layer specific gravitycore surface hardnesscover surface hardness.