Multi-layered golf balls containing a dual-core structure are provided. The core structure includes an inner core (center) made from a foam or metal-containing composition, or it has a hollow shell construction, and the outer core layer is made of a thermoplastic composition. Preferably, the thermoplastic composition comprises: a) ethylene acid copolymer, b) plasticizer, and c) cation source. A fatty acid ester such as ethyl oleate is preferably used as the plasticizer. The core assembly preferably has a positive hardness gradient extending across the entire assembly. The core structure and resulting ball have relatively good resiliency at given compressions.

An object of the present invention is to provide a golf ball having excellent abrasion resistance and spin performance on driver shots. The present invention provides a golf ball having a spherical core and a cover covering the spherical core, wherein the cover contains a polyurethane, wherein the polyurethane comprises, as a constituent component, (A) a polyisocyanate component and (B) a polyol component containing (b1) a polyrotaxane, and wherein (b1) the polyrotaxane has a cyclodextrin, a linear molecule piercing through the cyclic structure of the cyclodextrin, and a blocking group located at both terminals of the linear molecule to prevent disassociation of the cyclodextrin, and at least a part of hydroxyl groups of the cyclodextrin is modified with a caprolactone chain via OC.sub.3H.sub.6O group.

In a multi-piece solid golf ball having a core, an intermediate layer encasing the core and a cover which encases the intermediate layer and has numerous dimples on an outside surface thereof, the intermediate layer is formed of a resin material, the cover is formed of a urethane resin material, the core has a diameter of at least 38.0 mm, the sphere obtained by encasing the core with the intermediate layer has a surface hardness on the Shore D hardness scale of at least 69, the cover has a material hardness on the Shore D hardness scale of 55 or less, the (intermediate layer thickness)/(core diameter) value is from 0.025 to 0.043, the (cover thickness)/(core diameter) value is from 0.014 to 0.027, and the sphere obtained by encasing the core with the intermediate layer has an initial velocity A and the core has an initial velocity B which together satisfy the condition AB0 m/s.

In a golf ball including a core, an intermediate layer, and a cover, the relationship of the surface hardness between an intermediate layer-encased sphere and the ball satisfies a predetermined relational expression, and with an initial velocity of the ball and a deflection under a predetermined load applied to the ball optimized, and letting a value of (initial velocity of core?weight of core) be Ciw, a value of [(initial velocity of intermediate layer-encased sphere?initial velocity of core)?(weight of intermediate layer-encased sphere?weight of core)] be Miw, and a value of [(initial velocity of ball?initial velocity of intermediate layer-encased sphere)?(weight of ball?weight of intermediate layer-encased sphere)] be CViw, the expression of Ciw+Miw+CViw is optimized, and lift and drag coefficients at predetermined Reynolds numbers and spin rates of dimples are set to predetermined ranges.

The present invention provides a golf ball capable of exhibiting an excellent spin performance in approach shot while the effect on the spin performance in driver shot is being suppressed to be low. The golf ball of the present invention includes a core, a cover located outside the core and having dimples formed thereon, and a coating layer located outside the cover and formed with a material having a surface force of 130 N or less.

An object of the present invention is to provide a golf ball that can strike a good balance in approach performance under a rough condition and a wet condition while maintaining a flight distance on driver shots. The present invention provides a golf ball comprising a golf ball body and a paint film formed on a surface of the golf ball body, wherein the golf ball body has a spherical core, an intermediate layer covering the spherical core, and a cover covering the intermediate layer, and the paint film has a multi-layered construction composed of two or more layers, wherein a 10% elastic modulus (Pi10) of an innermost layer of the paint film is greater than a 10% elastic modulus (Po10) of an outermost layer of the paint film and a 10% elastic modulus (C10) of a material constituting the cover, and a thickness (Ti) of the innermost layer of the paint film is greater than a thickness (To) of the outermost layer of the paint film, a 10% elastic modulus (M10) of a material constituting the intermediate layer is greater than the 10% elastic modulus (C10) of the material constituting the cover, and a difference (Po10C10) between the 10% elastic modulus (Po10) of the outermost layer of the paint film and the 10% elastic modulus (C10) of the material constituting the cover is 4.0 kgf/cm.sup.2 or more and 50 kgf/cm.sup.2 or less, and a Shore D hardness (Hc) of the material constituting the cover is 40 or less.

In a golf ball having a two-layer core consisting of an inner core layer and an outer core layer and a cover of one or more layer, the inner core layer and outer core layer are each formed of a rubber composition made up primarily of a base rubber, the inner core layer has a diameter of not more than 30 mm; and the core has specific hardness ratios (JIS-C hardness/Shore D hardness) at specific points on the cross-section thereof. This golf ball has a reduced spin rate on full shots with a driver and middle irons, thus imparting to an excellent flight performance, and moreover has a good controllability in the short game on approach shots, making it ideal as a golf ball for professional golfers and mid- and high-level amateur golfers.

The present invention provides a golf ball capable of achieving a further decrease of the spin rate in the driver shot, and capable of more improving the flight distance, while maintaining high durability. The golf ball 1 of the present invention includes a core located in the center of the golf ball, a cover located outside the core and having a plurality of dimples on the surface thereof, and a metal mesh layer located between the core and the cover, wherein the metal mesh layer has a wire diameter falling within a range from 0.01 to 0.5 mm, and a mesh count falling within a range from 16 to 1000.

The present invention provides a golf ball having an outer surface comprising a plurality of dimples covering greater than 70 percent of the outer surface, wherein a plurality of the dimples incorporate directional surface texturing therein. The directional surface texturing preferably comprises substantially parallel channels or protrusions formed within the dimples. The directional surface texturing can comprise of parallel linear channels or protrusions or parallel non-linear linear channels or protrusions.

In order to satisfy at a high level the golf ball flight and control performances relied on by professional golfers and skilled amateurs, this invention provides a multi-piece solid golf ball G having a core 1, a cover 3 and an intermediate layer 2 therebetween wherein, letting Hc be the JIS-C hardness at a center of the core, H12 be the JIS-C hardness at a position 12 mm from the core center and Ho be the JIS-C hardness at a surface of the core, the core has a hardness profile which satisfies the condition (HoH12)(H12Hc)10; letting (HoH12)(H12Hc) above be A, the spin index of the ball, defined as the dynamic coefficient of friction of the ball multiplied by A, is at least 3.0; and the hardness profile index, defined as the deflection (mm) of the core when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf) multiplied by A, is at least 40.