A golf ball 2 includes a core 4, a cover 8 positioned outside the core 4, and a paint film 10 positioned outside the cover 8. The paint film 10 includes an inner layer 12 and an outer layer 14 positioned outside the inner layer 12. A 10% modulus Mo of the outer layer 14 is lower than a 10% modulus Mi of the inner layer 12. A difference (Mi-Mo) between the modulus Mi and the modulus Mo is not less than 25.0 kgf/cm.sup.2. The cover 8 has a Shore D hardness Hc of not less than 50 and not greater than 65. The cover 8 has a thickness Tc of not less than 0.80 mm and not greater than 1.80 mm.

An object of the present invention is to provide a golf ball having an excellent flight performance on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover covering the spherical core, wherein a hardness difference D1 (H75H0) between a hardness H75 at a point located at a distance of 75% of a core radius from a center of the spherical core and a center hardness H0 of the spherical core is 15 or more and 35 or less in Shore C hardness, a hardness difference D2 (HsH75) between a surface hardness Hs of the spherical core and the hardness H75 at the point located at the distance of 75% of the core radius from the center of the spherical core is 1 or more and 3.5 or less in Shore C hardness, and a hardness difference D3 ((H0+H75)/2H37.5) between a hardness of (the center hardness H0 of the spherical core+the hardness H75 at the point located at the distance of 75% of the core radius from the center of the spherical core)/2 and a hardness H37.5 at a point located at a distance of 37.5% of the core radius from the center of the spherical core is 0.5 or more and 6.5 or less in Shore C hardness.

Golf balls comprising a multi-layer core and a cover are disclosed. The multi-layer core comprises a layer formed from a highly neutralized polymer composition and a layer formed from a thermoset rubber.

Golf ball comprising layer(s) comprised of neutralized acid polymer composition consisting of mixture of: (a) low molecular weight acid-containing wax(es); (b) non-acid polymer(s) including at least one low molecular weight non-acid wax such as high density oxidized polyethylene homopolymers; ethylene maleic anhydride copolymers; polypropylene maleic anhydride copolymers; polypropylene homopolymers; ethylene-vinyl acetate copolymers; high density oxidized homopolymers; oxidized copolymers; polyethylene micronized waxes; polytetrafluoroethylene micronized waxes; emulsifiable low molecular weight non-acid waxes; non-emulsifiable low molecular weight non-acid waxes; and/or chemically modified low molecular weight non-acid waxes; and (c) organic acid(s) or salt thereof. Molecular weight of each low molecular weight acid-containing wax is about 500 to 7000, or up to 30,000. Interactions between components (a), (b), and (c) advantageously produce layer of ionomeric material having heat stability, processability, and well-retained durability, adhesion, CoR, compression and targeted feel without need for blending high and low molecular weight acid-containing polymer(s).

A golf ball includes a plurality of dimples on the surface thereof and satisfies the following expression (1):
PS.sub.7/S/H1006.25 (mm.sup.1)(1),
wherein H is a deformation amount, which is expressed by a compressive deformation amount of the golf ball; S is a virtual plane area, which is a surface area of the golf ball determined supposing that no dimple exists on the surface of the golf ball; and PS.sub.7 is a pressurized area, which is an area of the golf ball contacting a plane when a load of 6864 N is applied to the golf ball. The bottom of the dimple includes a center protruding portion with a curved shape protruding toward an outside of the golf ball.

To provide a golf ball that can prevent considerable decrease in carry distance of a driver shot when it rains and also can more reliably prevent adhesion of dirt, etc. to the surface of the golf ball. The golf ball of the present invention includes a core, a cover that is provided on an outer side of the core and has dimples, and an outermost layer that is formed on an outer side of the cover and made of a material having a contact angle of 90 or more and a dynamic contact angle of 85 or less. The golf ball may have a dynamic friction coefficient of 0.48 or less. The cover may be formed of a material having hardness of 48 or more in terms of Shore D Hardness. The outermost layer may be formed of a urethane coating containing a water repellent additive, as a main component.

To provide a golf ball that can prevent a decrease in carry distance of a driver shot when it rains and also, can exert excellent spinning performance upon an approach shot. The golf ball of the present invention includes a core, a cover that is provided on an outer side of the core and has dimples, and an outermost layer that is formed on an outer side of the cover and made of a material having a contact angle of 90 or more, the golf ball having a dynamic friction coefficient of 0.52 or more. The cover may be formed of thermoplastic polyurethane having hardness of 55 or more in terms of Shore D Hardness. The outermost layer may be formed of a urethane coating containing a water repellent additive, as a main component.

In a golf ball having a core, a cover of at least one layer and a paint film layer formed on a surface of the cover, the paint film layer has an elastic work recovery of at least 60%, the cover layer in contact with the paint film layer has a material hardness on the Shore D scale of at least 55 and, letting M be the elastic work recovery (%) of the paint film layer and N be the material hardness (Shore D hardness) of the cover layer, MN>0. The ball surface is scratch-resistant and has an excellent durability, and the ball has a reduced spin rate on shots with a driver or a long iron, resulting in an increased carry.

A golf ball (2) includes a core (4), an inner cover (6), a main cover (8), and an outer cover (10). X=HcRc0.05, S=HsRc0.05, M=HmTm, I=HiTi, O=HoTo, and Q=(I+O)/2 that are calculated from a radius Rc of the core (4), a Shore C hardness Hc at a central point of the core (4), a Shore C hardness Hs at a surface of the core (4), a thickness Tm of the main cover (8), a Shore C hardness Hm of the main cover (8), a thickness Ti of the inner cover (6), a Shore C hardness Hi of the inner cover (6), a thickness To of the outer cover (10) and a Shore C hardness Ho of the outer cover (10), satisfy 15MS100, 0.25<Q/M<0.5, 10IO30, and Q/X<0.8.

A golf ball (2) includes a core (4), an inner cover (6), a main cover (8), and an outer cover (10). X=HcRc0.05, S=HsRc0.05, M=HmTm, I=HiTi, O=HoTo, and Q=(I+O)/2 that are calculated from a radius Rc of the core (4), a Shore C hardness Hc at a central point of the core (4), a Shore C hardness Hs at a surface of the core (4), a thickness Tm of the main cover (8), a Shore C hardness Hm of the main cover (8), a thickness Ti of the inner cover (6), a Shore C hardness Hi of the inner cover (6), a thickness To of the outer cover (10) and a Shore C hardness Ho of the outer cover (10), satisfy 15MS100, 0.25<Q/M<0.5, 10IO30, and Q/X0.8.