A golf ball comprising: (a) a core; (b) an inner mantle layer; (c) an intermediate mantle layer; (d) an outer mantle layer; and (e) at least one cover layer; wherein the core has a PGA compression of less than 70, and the core/inner mantle layer/intermediate mantle layer combined construct has a PGA compression of at least 30.

A golf ball comprising a core composed of a fully neutralized polymer material is disclosed herein. The golf ball also preferably has multiple mantle layers and a cover.

A golf ball comprising: (a) a core; (b) at least one mantle layer adjacent to the core; (c) an inner cover layer adjacent to the mantle layer; and (d) an outer cover layer adjacent to the inner cover layer, wherein the inner cover layer has a material Shore D hardness that is at least 3 less than the material Shore D hardness of the outer cover layer, and the inner cover layer has a thickness of less than 0.050 in.

The present invention provides methods for producing molded golf balls and the resultant balls. The methods of this invention involve producing foamed polyurethane covers and these methods help reduce dimple distortions and other surface imperfections. These golf balls contain an inner core and outer foamed polyurethane cover. One or more intermediate layers can be disposed between the core and cover. In one embodiment, a castable liquid polyurethane composition containing a foaming agent is dispensed into mold cavities, which are then pressed together to form a foam cover for the ball.

An object of the present invention is to provide a cured product of a golf ball rubber composition for constituting a golf ball having excellent shot feeling on both driver shots and approach shots. The present invention provides a cured product of a golf ball rubber composition, wherein the golf ball rubber composition contains (a) a base rubber, (b) an α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof as a co-crosslinking agent, and (c) a crosslinking initiator, and a product (hardness×(tan δ.sub.−80−tan δ.sub.0)) obtained by multiplying a slab hardness of the cured product of the golf ball rubber composition in Shore C hardness by a difference (tan δ.sub.−80−tan δ.sub.0) between a loss tangent of the cured product of the golf ball rubber composition at −80° C. (tan δ.sub.−80) and a loss tangent of the cured product of the golf ball rubber composition at 0° C. (tan δ.sub.0) is 28.0 or more.

The use of a low molecular weight farnesene, poly(farnesene), and farnesene copolymer in a golf ball is disclosed herein. In a core, low molecular weight farnesene, poly(farnesene) or farnesene copolymer is blended with 1,4 polybutadiene or a polyalkenamer. In a mantle layer, low molecular weight farnesene, poly(farnesene), and/or farnesene copolymer can be blended with non- or partially neutralized copolymeric or terpolymeric ionomer(s). In a cover, low molecular weight farnesene, poly(farnesene), and farnesene copolymer can be blended with highly neutralized ionomer.

A golf ball resin composition includes (a) an olefin-α,β-unsaturated carboxylic acid copolymer and/or a metal ion neutralization product thereof or an olefin-α,β-unsaturated carboxylic acid-α,β-unsaturated carboxylic acid ester copolymer and/or a metal ion neutralization product thereof, (b) a phenolic resin and (c) a compound having at least two oxazoline groups per molecule, wherein the content of component (C) is from 0.1 to 5 parts by weight per 100 parts by weight of components (a) and (b) combined. The resin composition has excellent tensile properties and, when used in a golf ball, provides the ball with an excellent durability without lowering the spin performance and distance performance of the ball. The resin is especially useful as a golf ball cover material for an outermost layer or an intermediate layer.

In a golf ball having a core, an intermediate layer and a cover, the core is formed primarily of a base rubber, has a diameter set in a specific range and has a specially designed internal hardness profile, the intermediate layer and the cover are each formed of resin materials, and the surface hardness of the ball is higher than the surface hardness of the intermediate layer-encased sphere. This ball achieves a satisfactory distance on full shots with a driver and with long and middle irons, provides a good spin performance on approach shots, and has a durability to repeated impact and a scuff resistance that are both excellent.

A golf ball for amateur golfers is endowed with an excellent flight and a good feel at impact that is soft yet solid when hit by a golfer whose head speed is not very high. The ball, which includes a core and a cover, has a compressive deformation B when subjected to a final load of 30 kgf from an initial load state of 5 kgf that is from 0.72 to 0.97 mm and a compressive deformation C when subjected to a final load of 60 kgf from an initial load state of 5 kgf that is from 1.55 to 1.85 mm. In addition, the core has a hardness profile which satisfies specific conditions.

Golf balls having covers made of thermoplastic polyurethane compositions are provided. The golf ball includes an inner core and surrounding thermoplastic polyurethane outer cover. Multi-piece golf balls having outer cores, inner covers, and intermediate layers can be made. The invention includes cast molding methods for increasing the molecular weight of the thermoplastic polyurethane composition used to make the cover and ultimately to a golf ball cover having high shear and cut-resistance