Golf ball comprising layer(s) comprised of a mixture of: (a) low molecular weight acid-containing wax(es); (b) non-acid-polymer(s) including at least one low molecular weight non-acid wax such as high density oxidized polyethylene homopolymers; ethylene maleic anhydride copolymers; polypropylene maleic anhydride copolymers; polypropylene homopolymers; ethylene-vinyl acetate copolymers; high density oxidized homopolymers; oxidized copolymers; polyethylene micronized waxes; polytetrafluoroethylene micronized waxes; emulsifiable low molecular weight non-acid waxes; non-emulsifiable low molecular weight non-acid waxes; and/or chemically modified low molecular weight non-acid waxes; and (c) organic acid(s) or salt thereof. Molecular weight of each low molecular weight acid-containing wax is about 500 to 7000, or up to 30,000. Interactions between components (a), (b), and (c) advantageously produce layer of ionomeric material having heat stability, processability, and well-retained durability, adhesion, CoR, compression and targeted feel without need for blending high and low molecular weight acid-containing polymer(s).

A pre-molded dimple-free golf ball is formed before dimples are created in a thermoplastic cover of the pre-molded dimple-free golf ball.

Multi-piece golf balls containing a dual-core structure are provided. The core structure includes an inner core (center) comprising a foam composition, preferably foamed polyurethane. The outer core layer is preferably formed from a non-foamed thermoset composition such as polybutadiene rubber. The inner and outer core layers can have different hardness gradients. Preferably, the specific gravity (density) of the foam inner core is less than the density of the outer core layer. The ball further includes a cover of at least one layer and may include at least one casing layer. The core structure and resulting ball have relatively good resiliency.

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 polydimethylsiloxane compound. Functionalized polydimethylsiloxane compounds also can be used to treat thermoplastic polyurethane golf ball covers. 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 with thermoplastic polyurethane covers have good physical properties.

A golf ball 2 includes a core 4 and a cover 6 positioned outside the core 4. The cover 6 is formed in a mold having support pins by injection molding. A ratio (V/S) of a volume V (mm.sup.3) of the cover 6 to an amount of compressive deformation S (mm) of the core 4 is not less than 1000 and not greater than 1900. The cover 6 has a shore D hardness of not greater than 62. The golf ball 2 has a plurality of dimples 8 on a surface thereof. A total volume W of these dimples is not less than 490 mm.sup.3 and not greater than 620 mm.sup.3. A ratio (/P) of a latitude (degree) of each support pin to a total cross-sectional area P (mm.sup.2) of the support pins is not less than 0.35 and not greater than 0.60.

A golf ball comprising a core comprising an inner core center and an outer core layer disposed over the inner core center. The inner core center has a deflection of greater than 0.210 inch under a load of 100 kilograms, and the entire the core has a deflection ranging from 0.130 inch to 0.105 inch under a load of 100 kilograms. A mantle layer is disposed over the core and a cover is disposed over the mantle.

The golf teaching set in the form of a subconscious habit based on established experience contains a special golf training club no. 0, a swing trainer for learning the position of the striking area at the moment of impact and training golf balls. Training golf club no. 0 has zero loft and the plane of the striking area is reflected in the club's grip. The swing trainer serves to develop the ability to perceive the position of the striking area at the moment of impact. It is used together with training club no. 0, where a pupil tries to achieve clean contact, i.e. under an angle of 0, between the striking area and the area of the flexible panel.

Golf balls having a single or dual-layered solid core are provided. In one embodiment, the golf ball has dimensions and properties that do not conform to the rules of the United States Golf Association (USGA). For example, the ball weight; ball size; ball spherical symmetry; ball initial velocity; and/or ball overall distance may fall outside of the USGA standards. The dual-layered core can have an inner core comprising a thermoplastic composition and surrounding outer core comprising a thermoset composition. In another embodiment, the dual-layered core has an inner core comprising a thermoplastic composition and outer core comprising a thermoset composition. The thermoplastic composition preferably comprises an ethylene acid copolymer ionomer and plasticizer. The thermoset composition preferably comprises polybutadiene rubber. The ball further includes a cover of at least one layer.

An object of the present invention is to provide a golf ball resin composition having improved rebound resilience performance. The present invention provides a golf ball resin composition containing: (A) a thermoplastic resin having an infrared absorption peak in a region from 3200 cm.sup.1 to 3600 cm.sup.1, and (B) at least one resin component selected from the group consisting of (b-1) a binary copolymer composed of an olefin and an ,-unsaturated carboxylic acid having 3 to 8 carbon atoms, (b-2) a metal ion-neutralized product of a binary copolymer composed of an olefin and an ,-unsaturated carboxylic acid having 3 to 8 carbon atoms, (b-3) a ternary copolymer composed of an olefin, an ,-unsaturated carboxylic acid having 3 to 8 carbon atoms and an ,-unsaturated carboxylic acid ester, and (b-4) a metal ion-neutralized product of a ternary copolymer composed of an olefin, an ,-unsaturated carboxylic acid having 3 to 8 carbon atoms and an ,-unsaturated carboxylic acid ester, wherein when a relaxation modulus Er (20 C., 9%) of the golf ball resin composition is measured under conditions of 20 C. and a strain of 9%, a relaxation curve is plotted with the relaxation modulus (MPa) as the vertical axis and a logarithm (ln(t)) of time (sec) as the horizontal axis, and the relaxation curve is linearly approximated to obtain a linear approximation curve, the linear approximation curve has a slope in an absolute value of 7 or more.

A golf ball strikes a good balance between the durability and the shot feeling, and includes a spherical core and at least one cover disposed outside the spherical core. At least one layer of the cover contains (A) a base resin and (B) a resin fine particle, (A) the base resin contains an ionomer resin, and (B) the resin fine particles contain a polyrotaxane component having a cyclodextrin, a linear molecule penetrating the cyclic structure of the cyclodextrin in a skewering manner, and blocking groups located at both terminals of the linear molecule to prevent disassociation of the cyclodextrin wherein at least a part of hydroxyl groups of the cyclodextrin is modified with a caprolactone chain via a OC.sub.3H.sub.6O group.