A method of forming a golf ball is disclosed herein. The method includes injecting a cover mixture into a mold to form a cover mixture comprising a thermoplastic polyurethane resin and a polyahl, subjecting the golf ball to a polyisocyanated solution to create a golf ball with a polyisocyanated cover, and heating the golf ball or polyisocyanated cover to remove a solvent component of the polyisocyanated solution and promote the reaction of the polyisocyanate with the cover mixture and polyahl.

Golf balls comprising a multi-layer core and a cover are disclosed. The multi-layer core comprises a layer formed from a highly neutralized polymer composition and a layer formed from a thermoset rubber.

A golf ball comprising at least one layer comprised of a neutralized acid polymer composition consisting of a mixture of: (a) at least one low molecular weight acid-containing wax; (b) at least one non-acid-polymer; and (c) at least one organic acid or salt thereof. Each low molecular weight acid-containing wax may have a molecular weight of from about 500 to about 7000, and in some embodiments, the molecular weight may be considered low up to 30,000. Interactions between components (a), (b) and (c) as disclosed herein advantageously produce a layer of ionomeric material having desirable physical properties, such as heat stability, and processability (excellent melt flow) without the need for blending high and low molecular weight acid-containing polymer(s).

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.

A golf ball with a center core comprising polybutadiene and a carbon nanotube material in an amount ranging from 0.4 to 2.5 weight percent of the center core is disclosed herein. Alternatively, the golf ball has a mantle layer with a blend of ionomer materials and a carbon nanotube material in an amount ranging from 0.2 to 2.5 weight percent of the mantle layer.

Multi-layered golf balls containing a dual-core structure are provided. The core structure includes an inner core (center) comprising a thermoplastic composition, preferably including: a) ethylene acid copolymer, b) plasticizer, and c) cation source. Preferably, a fatty acid ester such as ethyl oleate is used as the plasticizer. The outer core layer is preferably formed from a thermoset composition such as polybutadiene rubber. The core layers have different hardness levels. For example, the inner core can have a positive, zero, or negative hardness gradient. The core assembly preferably has a positive hardness gradient extending across the entire assembly. The core structure and resulting ball have relatively good resiliency at given compressions.

In a multi-piece solid golf ball having a core, an envelope layer, an intermediate layer, and a cover with a plurality of dimples thereon, the core is a two-layer core consisting of an inner core layer and an outer core layer each formed primarily of a base rubber, the envelope layer, the intermediate layer and the cover layer are each composed of at least one layer and formed primarily of a synthetic resin material, and the initial velocities and surface hardnesses of the core, the envelope layer-encased sphere and the intermediate layer-encased sphere are designed within specific ranges. This golf ball satisfies at a very high level the flight and control performances expected for use by professional golfers and skilled amateurs, has the ability to move forward on a straight path particularly on full shots, and also has an excellent scuff resistance.

In a multi-piece solid golf ball having a two-layer core with an inner core layer and an outer core layer, a cover, and at least one intermediate layer between the core and cover, the inner and outer core layers are formed of different rubber compositions, and the intermediate layer and the cover are formed of different resin compositions. The inner core layer diameter, the hardness relationship between the surface of the outer core layer and the center of the inner core layer, and the material hardness of the intermediate layer fall within specific ranges. Also, within the ball, the intermediate layer-encased sphere has a higher surface hardness than the cover-encased sphere. This golf ball has a larger spin rate-lowering effect on full shots with a driver, resulting in an increased distance, and also has an excellent spin performance on approach shots, thus providing the golfer with a competitive advantage.

Multi-layered golf balls having at least one layer made of a polyamide composition containing a transparent polyamide polymer and fatty acid salt are provided. In one preferred version, the polyamide composition consists essentially of a blend of 40 to 99% by weight transparent polyamide and 1 to 60% by weight fatty acid salt. The golf ball includes a core having at least one layer and a cover having at least one layer. The polyamide composition may be used to form any core, cover, or other layer in the golf ball. The polyamide compositions have a good combination of properties including Coefficient of Restitution (COR) and compression.

A multi-piece golf ball comprising at least one component made of a polybutadiene rubber/ionomer resin blend is provided. The ball preferably contains a dual-core comprising an inner core and surrounding outer core layer. Preferably, the polybutadiene rubber/ionomer resin blend is used to form the outer core layer. Preferably, the outer surface hardness of the outer core layer is greater than the outer surface hardness of the inner core. The resulting ball has high resiliency and good impact durability.