Disclosed is a carbon nanotube golf ball having improved hitting feel and durability, and antistatic property comprising: a core having CNT/ionomer-dispersion; a cover formed on the core; and an antistatic finish on the top cover. Herein, CNT/ionomer-dispersions having a diameter of 10 to 3,000 m are produced in advance using an independent process, and then applied to the present art. The top cover is provided with antistatic finish using a CNT coating solution for keeping the clean surface during the golf play.

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 core has a deflection when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf) of at least 3.9 mm, the core has a center and a surface such that the value obtained by subtracting the JIS-C hardness at the core center from the JIS-C hardness at the core surface is at least 15, the sphere obtained by encasing the core with the intermediate layer (intermediate layer-encased sphere) has a surface hardness on the Shore D hardness scale of at least 69, the ball has a surface hardness on the Shore D hardness scale of 62 or less, and 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.

In a multi-piece solid golf ball having a core, an envelope layer, an intermediate layer and a cover, the envelope layer is formed into two layersan inner envelope layer and an outer envelope layer. The inner envelope layer-encased sphere, outer envelope layer-encased sphere, intermediate layer-encased sphere and ball have respective surface hardnesses that satisfy a specific relationship. The inner envelope layer or outer envelope layer is formed primarily of one or more thermoplastic elastomer selected from the group consisting of polyester elastomers, polyamide elastomers, polyurethane elastomers, olefin elastomers and styrene elastomers. This ball has an excellent flight when struck by golfers whose head speeds are not that fast and has a good, soft feel at impact, thus making it highly suitable for amateur golfers.

In a multi-piece solid golf ball having a core, an intermediate layer and a cover, the cover is formed primarily of a polyurethane material, the ball has a higher surface hardness on the Shore C hardness scale than the sphere obtained by encasing the core with the intermediate layer (intermediate layer-encased sphere), and the ball has a deflection of at least 3.6 mm when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf). The golf ball has an excellent flight performance when hit by golfers whose head speeds are not very fast and moreover has a good, soft feel at impact, making it suitable for use by amateur golfers.

In a multi-piece solid golf ball having a core formed of a rubber composition, an intermediate layer formed of a polyurethane material and a cover, the ball satisfies the following condition: surface hardness of ballsurface hardness of intermediate layer-encased sphere. When the ball is struck with a driver at a head speed of 40 m/s, the sum of the time t1 required from contact initiation between the driver and ball for deformation of the ball to reach a maximum value and the time t2 required from the state of maximum ball deformation for the ball and driver clubface to separate is at least 705 microseconds. This ball has an excellent flight performance when hit by low or moderate head-speed golfers, is receptive to spin on approach shots and has a good, soft feel at impact.

An object of the present invention is to provide a golf ball having excellent spin performance on approach shots under a wet condition and excellent spin performance on approach shots under a condition that there is grass between the golf ball and the club face. The present invention provides a golf ball comprising a golf ball body and a paint film composed of at least one layer and formed on a surface of the golf ball body, wherein an outermost layer of the paint film located at the outermost layer of the golf ball contains a base resin and a porous filler, the base resin contains a polyurethane obtained by a reaction between a polyisocyanate composition and a polyol composition, and the porous filler contains SiO.sub.2 in an amount of 50 mass % or more as a constituent component.

An object of the present invention is to provide a golf ball having excellent spin performance on approach shots under a wet condition and excellent spin performance on approach shots under a condition that there is grass between the golf ball and the club face. The present invention provides a golf ball comprising a golf ball body and a paint film composed of at least one layer and formed on a surface of the golf ball body, wherein an outermost layer of the paint film located at the outermost layer of the golf ball contains a base resin and a porous filer, the base resin contains a polyurethane obtained by a reaction between (A) a polyisocyanate composition and (B) a polyol composition containing a urethane polyol as a polyol component, the porous filler contains SiO.sub.2 in an amount of 50 mass % or more as a constituent component, and a loss tangent (tan ) of the outermost layer of the paint film measured with a dynamic viscoelasticity measuring apparatus under following conditions has a peak temperature in a range of from 40 C. to 40 C.

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.

A golf ball with a coating disposed on a cover that is infused with graphene in an amount ranging from 0.01% to 5% based on a dry weight of the paint film is disclosed herein. The coating is preferably based on polyurethane chemistry where hydroxyl functional polymers are cured with polyisocyanate-based hardeners. The coating is preferably applied in a dipping process or a spraying process.

In a golf ball having a core of at least one layer and a cover encasing the core, the cover is formed of a resin composition composed primarily of a polyurethane or a polyurea. Letting HMa (N/mm.sup.2) be the Martens hardness of the cover measured at a position 0.3 mm toward the center of the ball from the cover surface and Ita (%) be the elastic recovery of the cover, HMa and Ita satisfy the following conditions: (1) Ita1.16HMa+79, (2) 10.0HMa38.0, and (3) 40Ita80. The ball has an excellent spin performance on approach shots and an excellent scuff resistance.