In a multi-piece solid golf ball having a core, an envelope layer, an intermediate layer and a cover, the core, an intermediate layer-encased sphere and the ball have surface hardnesses which satisfy a specific relationship, and the envelope layer, the intermediate layer and the cover have thicknesses which satisfy a specific relationship. Also, the core has a hardness profile in which the hardnesses at the core surface, core center, a position 5 mm from the core center, and a position midway between the surface and center of the core satisfy specific relationships. This golf ball, when used by mid- and high-level amateurs, enables the golfer to maintain an adequate distance on shots with a driver and achieve a good distance on iron shots, has a good spin performance on approach shots and has a good feel on impact. In addition, the ball has an excellent scuff resistance when struck with a grooved wedge.

Methods for coatings for golf balls, particularly golf balls having thermoplastic polyurethane covers, and the resulting finished balls are provided. The coating is preferably a topcoat comprising a polyurethane composition containing optical brighteners. The topcoat composition may comprise a low concentration of optical brighteners. For example, the concentration of optical brightener can be in the range of 0.01 to about 0.20 weight %. Multi-piece golf balls having inner cores, outer cores, inner covers, and intermediate layers can be made. The finished ball with the topcoat has many advantageous physical and playing performance properties.

In a golf ball having a two-layer core consisting of an inner core layer and an outer core layer, one or more intermediate layer, and a cover serving as an outermost layer, the inner core layer and outer core layer are each formed primarily of a base rubber, the inner core layer has a diameter of at least 19 mm, the intermediate layer and the cover are each formed primarily of a resin material, and the overall core has a specific hardness profile. The golf ball has a high initial velocity while holding down the spin rate on full shots with a driver or long iron, thus enabling a good distance to be achieved. The ball also has a high controllability in the short game.

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)

Disclosed herein are golf balls having a thermoplastic outer cover layer formed from a thermoplastic polyurethane composition. The golf balls are produced without the use of a secondary treatment step that would result in the crosslinking of the polyurethane cover composition.

A golf ball with embedded electronics to allow proximity to be tracked and to monitor golfer performance is disclosed. The golf ball comprises a processor connected to an accelerometer, communications circuitry, a spin detector, and memory, wherein the processor stores accelerometer data from the accelerometer and rotation data regarding rotation of the spin detector in the memory. The processor converts the data regarding the rotation of the spin detector into a rotation speed and a rotation direction, said rotation speed determined by a frequency of the data, and said rotation direction determined by a magnitude of the data. The communications circuitry is configured to communicate the accelerometer data, the rotation direction, and the rotation speed to a central interrogator for analysis of a golfer's performance.

A golf ball has a plurality of dimples 12 and a land 14 on a surface thereof. The golf ball further has a large number of minute projections 18 formed on surfaces of the dimples 12 and the land 14. The surface of the golf ball has an arithmetic average height Sa of not less than 0.5 m and not greater than 30 m. An average value Hav of heights H of the minute projections 18 is not less than 0.5 m and not greater than 50 m. A ratio Pp of a sum of areas of all the minute projections 18 to a surface area of a phantom sphere of the golf ball is not less than 7%. An average value Dav of diameters D of the minute projections 18 is not less than 5 m and not greater than 50 m.

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 is provided with 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 has a dynamic friction coefficient of 0.52 or more. The material constituting the outermost layer comprises a urethane coating that contains a water repellent additive, and the water repellent additive includes a fluorinated surfactant, silicone-modified acrylate or hydrophobic silica. The urethane coating comprises a polyisocyanate as a curing agent, and the polyisocyanate includes both an adduct form and an isocyanurate form of hexamethylene diisocyanate, and a mixing ratio (isocyanurate form/adduct form) of the isocyanurate and adduct forms of the hexamethylene diisocyanate, expressed as a mass ratio, is from 95/5 to 40/60.

In a multi-piece solid golf ball having a core, a cover and an intermediate layer therebetween, the core, an intermediate layer-encased sphere and the ball have surface hardnesses which satisfy a specific relationship, and the intermediate layer and the cover have thicknesses which satisfy a specific relationship. Also, the core has a hardness profile in which the hardnesses at the core surface, core center, a position 5 mm from the core center, and a position midway between the surface and center of the core satisfy specific relationships. This golf ball, when used by mid- and high-level amateurs, enables the golfer to maintain an adequate distance on shots with a driver and achieve a good distance on iron shots, has a good spin performance on approach shots and has a good feel on impact. In addition, the ball has an excellent scuff resistance when struck with a grooved wedge.