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.

Disclosed is a matte golf ball paint composition that provides a solution to the problem with a golf ball having a difficulty of taking on the original color of the cover due to scattering of the color incurred during the injection molding of the ball, thus helping deliver the original color of the cover; a matte golf ball that not only takes on the original color of the cover but also provides a combination of improved driving distance, spin, and control; and a method for manufacturing a matte golf ball with excellent weather resistance, water resistance, yellowing resistance, and abrasion resistance.

A golf ball with a core comprising polybutadiene and graphene is disclosed herein. The golf ball has a single core comprising polybutadiene and graphene. Alternatively, the golf ball has a dual core with an inner core comprising polybutadiene and graphene. Alternatively, the golf ball has a dual core with an outer core comprising polybutadiene and graphene.

A method for manufacturing a golf ball having a core, an intermediate layer and a cover that is formed of a resin material composed primarily of a polyurethane resin and has a thickness of 0.1 mm to 0.7 mm by injection molding the cover using a vertically separating two-part injection mold having specific gate and support pin configurations. This method enables a relatively soft urethane resin cover that is thin and of high quality to be formed, and has a good golf ball productivity.

An object of the present invention is to provide a golf ball having excellent durability. The present invention provides a golf ball comprising a spherical core composed of an inner core layer and an outer core layer, and at least one cover covering the spherical core, wherein the inner core layer is formed from an inner core layer rubber composition containing (a) a base rubber, (b) an α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof as a co-crosslinking agent, (c) a crosslinking initiator, and (d) a terpene-based resin.

In a golf ball having a core, envelope layer, intermediate layer and cover, the core has a specific hardness profile, the resin materials making up either or both of the envelope layer and the intermediate layer contain a high-acid ionomer, and the Shore C hardness relationships among the core center, surface of the envelope-encased layer and surface of the intermediate layer-encased sphere satisfy the following conditions:

surface hardness of envelope layer-encased sphere<surface hardness of intermediate layer-encased sphere,  (1)

surface hardness of intermediate layer-encased sphere−center hardness of core≥40.  (2)

This ball achieves a good distance on shots with utility and iron clubs, is receptive to spin in the short game, and has a soft feel at impact on all shots, making it useful to amateur golfers.

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 core is formed of a rubber composition including the specific ingredient compounding ingredients, 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 core has a deflection when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf) of at least 3.9 mm, the sphere obtained by encasing the core with the intermediate layer (intermediate layer-encased sphere) has a surface hardness on the Shore D hardness scale of at least 69, the ball has a surface hardness on the Shore D hardness scale of 62 or less, and 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.

A method for forming a golf ball with a graphene core disclosed herein. The method includes mixing a graphene masterbatch material with a polybutadiene material to form a core mixture, wherein the graphene masterbatch material comprises graphene in an amount from 0.1 to 80.0 weight percent of the graphene masterbatch material mixed with a carrier polymer in an amount from 99.9 to 20 weight percent of the graphene masterbatch material.

A golf ball paint composition includes primarily a urethane paint containing polyol as a base resin and polyisocyanate as a curing agent. The polyisocyanate includes two types of isocyanurate and adduct of hexamethylene diisocyanate and the golf ball paint composition has an elastic work recovery of at least 70%. The paint composition has a high self-repairing ability and is of high quality as a golf ball paint. Golf balls coated with this composition are able to maintain a good durability, in addition to which they have an excellent abrasion resistance and an excellent ball appearance.

A golf ball with a cover layer composed of a blend of non- or partially neutralized copolymeric or terpolymeric ionomer(s), hydroxyl-functionalized styrenic block copolymer and silane coupling agent (SCA). The amount of SCA is preferably between 0.01 and 2.0 weight percent based on the total weight of the polymer composition. The cover layer preferably has a Shore A hardness less than 90.