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 epoxy compound. Mixtures of multi-functional amines and imines, and multi-functional isocyanates, and epoxy curing agents; and solvent, can be applied to the outer cover. 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. 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. In one embodiment, the outer cover layer is formed from a composition comprising a thermoplastic polyurethane and epoxy compound. In another embodiment, the cover composition comprises a reaction product of thermoplastic polyurethane, epoxy-functional compound, and epoxy curing agent. Surface coatings of isocyanates, amines, and imines also can be applied to the cover. The cover composition and surface coatings can further include catalysts, ultraviolet (UV)-light stabilizers, and other additives.

In a multi-piece solid golf ball having a core, an envelope layer encasing the core, an intermediate layer encasing the envelope layer, and an outermost layer encasing the intermediate layer, the envelope layer-encased sphere, the intermediate layer-encased sphere and the ball have surface hardnesses which satisfy a specific relationship, the intermediate layer and the cover have thicknesses which satisfy a specific relationship, and 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 core surface and center satisfy specific relationships. This golf ball satisfies at a high level the flight and control performances desired for use by professional golfers and skilled amateurs. In particular, it holds down the spin rate on full shots and follows a straight trajectory, thus having a superior flight performance, and moreover is endowed with an excellent scuff resistance.

An object of the present disclosure is to provide a golf ball from which stain such as mud or grass juice can be wiped off when the stain is adhered to the golf ball while the spin performance of the golf ball on approach shots is not substantially lowered. The present disclosure 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 at least one layer of the paint film contains a polyurethane as a resin component, and the polyurethane has a structural unit derived from a polyether polycarbonate diol.

The invention provides a golf ball having a core and a cover of one or more layer encasing the core, wherein the cover has an outermost layer molded of a thermoplastic material selected from the group consisting of polyurethane, polyurea and mixtures thereof and, letting the absorbance peak heights near a wave number of 1512 cm.sup.1 measured by the attenuated total reflectance method in Fourier transform infrared absorption spectroscopy (FT-IR/ATR spectroscopy) at an outside portion and an inside portion of the outermost cover layer be respectively P.sub.1 and P.sub.2, the value P.sub.1-P.sub.2 is at least 0.02.

The invention provides a golf ball having a core and a cover of one or more layer encasing the core, wherein the cover has an outermost layer molded of a thermoplastic material selected from the group consisting of polyurethane, polyurea and mixtures thereof and, letting the absorbance peak heights near a wave number of 1512 cm.sup.1 measured by the attenuated total reflectance method in Fourier transform infrared absorption spectroscopy (FT-IR/ATR spectroscopy) at an outside portion and an inside portion of the outermost cover layer be respectively P.sub.1 and P.sub.2, the value P.sub.1P.sub.2 is at least 0.02.

The invention provides a method of manufacturing a golf ball having a core and a cover of one or more layer over the core, wherein an outermost layer of the cover is molded of a thermoplastic material selected from the group consisting of polyurethane, polyurea and mixtures thereof. The method includes at least the following steps (1) and (2): (1) treating a surface of the cover with an isocyanate compound; and (2) washing off and physically removing excess isocyanate compound by blasting the cover surface with a specific substance at high pressure.

Multi-piece golf balls having at least one layer made from a polyamide non-ionomeric composition are provided. The polyamide composition consists essentially of about 40 to about 99% by weight polyamide; about 1 to about 60% by weight of an acid anhydride-modified polyolefin; and about 1 to about 60% of a fatty acid additive selected from the group consisting of fatty acid salts, fatty acid amides, and mixtures thereof. The ball includes a core, preferably a dual core construction; and a cover of at least one layer. In another preferred construction, a multi-layered core containing an inner, intermediate, and outer core layer is made. For example, the intermediate core layer may be made of a rubber composition; and each of the inner core and outer core layers may be made of the polyamide composition. The resulting ball has high resiliency along with a soft feel.

The invention provides a method of manufacturing a golf ball having a core and a cover of one or more layer over the core, wherein an outermost layer of the cover is molded of a thermoplastic material selected from the group consisting of polyurethane, polyurea and mixtures thereof. The method includes at least the following steps (1) and (2): (1) treating a surface of the cover with an isocyanate compound; and (2) washing off and physically removing excess isocyanate compound by blasting the cover surface with a specific substance at high pressure.