A golf ball having an outer surface with a pattern forming a polyhedron. The pattern can be flat faces forming sharp edges and sharp points therebetween. In one embodiment, the polyhedron is a Goldberg polyhedron.

A rubber composition for golf balls includes (a) a base rubber, (b) a co-crosslinking agent which is an α,β-unsaturated carboxylic acid and/or a metal salt thereof, (c) an organic peroxide, (d) water or an alcohol, and (e) an antioxidant which is a benzoimidazole of the following general formula and/or a metal salt thereof. When the rubber composition is used in constituent members of a golf ball, especially the core, the golf ball exhibits low spin properties on shots, resulting in an improved flight performance and enabling a good durability to be maintained.

A golf ball wherein a slide amount Ds is 1.05 mm or less and a post-slide contact time Tc is 600 μs or more in the case where a golf ball 140 is dropped freely from a height position of 3 m above and away from a collision surface 130a inclined 58 degrees with respect to a horizontal direction to collide with the collision surface, the slide amount Ds being a vertical displacement of the golf ball from when the golf ball starts sliding on the collision surface to when the golf ball stops sliding on the collision surface, and the post-slide contact time Tc being a period from when the golf ball stops sliding on the collision surface to when the golf ball leaves the collision surface.

Golf balls having covers made of thermoplastic polyurethane compositions are provided. Multi-piece golf balls can be made. In one embodiment, the outer cover layer is formed from a composition comprising a thermoplastic polyurethane and acid copolymer ionomer. The cover composition also can contain hydroxyl-containing compounds. The golf ball having the thermoplastic polyurethane cover can be treated with an isocyanate compound. The golf ball also can be treated with an amine and/or silane-containing compound. The cover composition and surface coatings can further include catalysts, ultraviolet (UV)-light stabilizers, and other additives. The coating methods have many benefits and the finished balls have good physical properties.

A golf ball has a core, an inner cover, an outer cover, and dimples. The golf ball satisfies the following mathematical formulas.

Sa=4500+10(A0.5B2Cs)4000

0.04Sa+16020D0.04Sa+160+20 A: a compression (Atti) of the golfball B: a hardness difference (Shore C) between a surface and a center of the core

Cs: (HiTi+2HoTo)/(Ti+2To) D: a total volume (mm.sup.3) of the dimples Hi: a hardness (Shore D) of the inner cover Ho: a hardness (Shore D) of the outer cover Ti: a thickness (mm) of the inner cover To: a thickness (mm) of the outer cover

A golf ball has a core, an inner cover, an outer cover, and dimples, and satisfies the following mathematical formulas.

Vw=54+0.01(2.5AB+5Cv)58.0

0.08X.sup.24.25X+34520D0.08X.sup.24.25X+345+20

A: a compression of the golf ball

B: a hardness difference between a surface and a center of the core

Cv:(HiTi+HoTo)/(Ti+To)

Cs:(HiTi+2HoTo)/(Ti+2To)

D: a total volume of the dimples

X:Sw/Vw

Hi: a hardness of the inner cover

Ho: a hardness of the outer cover

Ti: a thickness of the inner cover

To: a thickness of the outer cover

Sw: 3000+10(AB1.5Cs)

A golf ball 2 includes a main body 4 and a paint layer 6 positioned outside the main body 4. The main body 4 includes a spherical core 8, a mid layer 10 positioned outside the core 8, and a cover 12 positioned outside the mid layer 10. An outer surface of the paint layer 6 forms a surface of the golf ball 2. A contact angle CAw with respect to water measured on the surface of the golf ball 2 is not less than 70 degrees. The paint layer 6 is preferably formed from a resin composition. A preferable resin composition includes a polyurethane as a base resin and includes a silicone compound and/or a fluorine compound. Another preferable resin composition includes a silicone compound and/or a fluorine compound as a base resin and includes no polyurethane.

Golf balls having covers made of thermoplastic polyurethane compositions are provided. Multi-piece golf balls can be made. Polyurethane primer coatings and polyurethane top-coatings are applied to the thermoplastic polyurethane cover. Isocyanate-rich and polyol-rich polyurethane coatings can be applied. In one embodiment, multi-functional imine and amine compounds can be used to treat the golf ball. The resulting coating may contain polyurethanes, polyureas, and hybrids, copolymers, and blends thereof. The cover composition and surface coatings can further include catalysts, ultraviolet (UV)light stabilizers, and other additives. Heat is used to cure the coatings. The coating methods have many benefits and the finished balls have good physical properties.

A golf ball includes a core, a mid layer, and a cover. A ratio R1 calculated by mathematical formula (1): R1=(Df1Df2)/(Df2Df3) is not less than 5.00. A ratio R2 calculated by mathematical formula (2): R2=(T2*H2)/H3 is not less than 2.00. A ratio R3 calculated by mathematical formula (3): R3=D1/T3 is not less than 50. In mathematical formulas (1) to (3), Df1 represents an amount of compressive deformation of the core, Df2 represents an amount of compressive deformation of a sphere including the core and the mid layer, Df3 represents an amount of compressive deformation of the golf ball, T2 represents a thickness of the mid layer, H2 represents a hardness of the mid layer, H3 represents a hardness of the cover, D1 represents a diameter of the core, and T3 represents a thickness of the cover.

A golf ball includes a core, a mid layer, and a cover. A ratio R1 calculated by mathematical formula (1): R1=(Df1Df2)/(Df2Df3) is not less than 5.00. A ratio R2 calculated by mathematical formula (2): R2=(T2*H2)/H3 is not less than 2.00. A ratio R3 calculated by mathematical formula (3): R3=D1/T3 is less than 50. In mathematical formulas (1) to (3), Df1 represents an amount of compressive deformation of the core, Df2 represents an amount of compressive deformation of a sphere including the core and the mid layer, Df3 represents an amount of compressive deformation of the golf ball, T2 represents a thickness of the mid layer, H2 represents a hardness of the mid layer, H3 represents a hardness of the cover, D1 represents a diameter of the core, and T3 represents a thickness of the cover.