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.

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, ultraviolt (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.

Multi-piece golf balls containing a multi-layered core structure are provided. The core structure includes a small, heavy inner core (center) having a relatively high specific gravity, an intermediate core layer, and a surrounding outer core layer. The layers of the core structure may have different hardness gradients. In one preferred embodiment, each core layer has a positive hardness gradient. The center of the core comprises a metal material such as copper, steel, brass, tungsten, titanium, aluminum, and alloys thereof. The intermediate core layer is preferably formed from a thermoset composition such as polybutadiene rubber, and the outer core layer is preferably formed from a thermoplastic composition such as an ethylene acid copolymer. The resulting ball has high resiliency and good spin control.

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.

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 textures that are different.

In a multi-piece solid golf ball having a core, an envelope layer, an intermediate layer and a cover, the core is formed primarily of a base rubber, the envelope layer, intermediate layer and cover are each formed of a resin material, and the envelope layer is formed into two layersan inner layer and an outer layer. The center and surface hardnesses of the core, the surface hardness of the inner envelope layer-encased sphere, the surface hardness of the outer envelope layer-encased sphere, the surface hardness of the intermediate layer-encased sphere and the surface hardness of the ball together satisfy a specific relationship. This ball exhibits a flight performance capable of satisfying professional golfers and skilled amateurs and possesses an excellent controllability on approach shots, in addition to which it has a good feel at impact and an excellent scuff resistance.

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 a hydroxyl 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.

An object of the present invention is to provide a golf ball having excellent approach spin performance under a dry condition and excellent approach spin performance 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 formed on a surface of the golf ball body, wherein the paint film is composed of at least one layer, and an outermost paint film layer located at the outermost layer of the golf ball contains, as a base resin, a polyurethane obtained by a reaction between (A) a polyisocyanate composition and (B) a polyol composition, and the outermost paint film layer has a dynamic friction coefficient of from 0.75 to 1.5 measured with a dynamic friction tester under specific conditions.

The present invention provides a method for arranging dimples on a golf ball surface in which the dimples are arranged in a pattern derived from at least one irregular domain generated from a regular or non-regular polyhedron. The method includes choosing control points of a polyhedron, generating an irregular domain based on those control points, packing the irregular domain with dimples, and tessellating the irregular domain to cover the surface of the golf ball. The control points include the center of a polyhedral face, a vertex of the polyhedron, a midpoint or other point on an edge of the polyhedron and others. The method ensures that the symmetry of the underlying polyhedron is preserved while minimizing or eliminating great circles due to parting lines.

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.