An object of the present disclosure is to provide a golf ball having good shot feeling and excellent durability and not having lowered resilience even if a hard cover material is used. The present disclosure provides a golf ball comprising a spherical core, and a cover disposed outside the spherical core and composed of one or more layers, wherein at least one cover layer contains (A) a base resin, and (B) at least one member selected from the group consisting of a polyrotaxane, a polyethylene oxide, a polypropylene oxide, a polycaprolactone and a liquid polymer, and Sa?Spc?100 wherein Sa (?m) is an arithmetic mean roughness of a surface of a cut plane of the cover, and Spc (mm.sup.?1) is an arithmetic mean curvature of a summit of the surface of the cut plane of the cover.

The present invention provides a golf ball having an aerodynamic subsurface for packing dimples. More particularly, the invention relates to a golf ball having an exterior surface and at least a first subsurface containing at least two dimples located solely on the subsurface and lying below the exterior surface of the golf ball. A transition zone between the exterior surface and the subsurface is disclosed having an angle of transition and a top radius and a bottom radius.

Golf ball comprising dimple(s) incorporating three or more linear channels having the same channel length L and same channel width CW; all linear channels extend radially outward from a centroid of the dimple toward a perimeter of the dimple without intersecting the dimple's centroid. Each linear channel may extend radially outward from a location on the dimple that is a distance Cd from the dimple's centroid, wherein Cd>0. Alternatively, at least one of the three or more linear channels has a different channel length L and/or a different channel width CW than at least one other linear channel. Dimple may have circular or non-circular plan shape; channels may not intersect each other; at least one linear channel may intersect the dimple's perimeter; and linear channels may be spaced by n separation angles .sub.S, wherein n is number of linear channels, which may be equal, or at least two differ.

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.

The present invention is directed to golf balls having improved aerodynamic performance due, at least in part, to the selection of the plan shapes of the dimples thereon. In particular, the present invention is directed to a golf ball that includes at least a portion of its dimples having a plan shape defined by low frequency periodic functions along a closed simple path. In addition, the present invention provides methods for designing dimples having a plan shape defined by a low frequency periodic function along a closed simple path.

The present invention is a golf ball which comprises spherical-cosine dimples on the surface thereof. The spherical-cosine dimples have a cross-sectional shape defined by the superposition of a spherical function and a cosine function. Each of the spherical-cosine dimples preferably has a dimple diameter of 0.180 inches or greater.

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.

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. An average depth Fav of the dimples 12 and an average height Hav of the minute projections satisfy the following mathematical formula (1).

Hav/Fav0.050 (1)

A ratio M (%) of a sum of areas of all the dimples 12 relative to a surface area of a phantom sphere of the golf ball and an average value Pav (m) of pitches P each between a minute projection 18 and another minute projection 18 adjacent to this minute projection 18 satisfy the following mathematical formula (2).

M/Pav>0.3 (2)

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.

The present invention provides a golf ball having an aerodynamic subsurface for packing dimples. More particularly, the invention relates to a golf ball having an exterior surface and at least a first subsurface containing at least two dimples located solely on the subsurface and lying below the exterior surface of the golf ball. A transition zone between the exterior surface and the subsurface is disclosed having an angle of transition and a top radius and a bottom radius. According to the present invention, the exterior surface and at least the first subsurface have at least a first and second surface colors that are different.