A golf ball comprising a core and a cover, wherein the core consists of: a solid inner core layer formed from an unfoamed thermoplastic composition and having a diameter of 1.10 inch or less and a center Shore C hardness (H.sub.center) of 50 or less, one or more optional intermediate core layers, and an outer core layer formed from an unfoamed thermoset composition and having a thickness of 0.200 inches or greater and an outer surface Shore C hardness (H.sub.outer surface) of 70 or greater, wherein H.sub.outer surface>H.sub.center, and H.sub.outer surface−H.sub.center≧40.

Golf ball having at least three layers comprising ionomeric and/or HNP compositions, wherein for each two adjacent layers, a relationship is established between a ratio of the volumes of the two adjacent layers and a ratio of the percent neutralizations of those two layers such that the volumes and % neutralizations of all layers are interrelated and interdependent to produce unique and desirable playing characteristics. In one embodiment, a golf ball of the invention has T layers, wherein T≧3 and each of T layers has a different volume “V” and comprises an ionomeric and/or HNP composition having a different % neutralization “N”. Furthermore, each of n inner layers of the T layers (n<T) has an adjacent surrounding layer n+1 such that a volume V.sub.n and a % neutralization N.sub.n of each inner layer and a volume V.sub.(n+1) and % neutralization N.sub.(n+1) of each adjacent surrounding layer n+1 satisfy the relationship (V.sub.n−V.sub.(n+1))/N.sub.n≧(N.sub.n−N.sub.(n+1))/N.sub.(n+1).

Golf ball having at least three layers comprising an ionomeric and/or HNP composition, wherein for each two adjacent layers, a relationship is established between a ratio of the volumes of the two adjacent layers and a ratio of the percent neutralizations of those two layers such that the volumes and % neutralizations of all layers are interrelated and interdependent to produce unique and desirable playing characteristics. In one embodiment, each of T layers, wherein T≧3, has a different volume “V” and comprises an ionomeric/HNP composition having a different % neutralization “N”; and wherein each of n inner layers of the T layers (n<T) has an adjacent surrounding layer n+1 such that a volume V.sub.n and a % neutralization N.sub.n of each inner layer and a volume V.sub.(n+1) and % neutralization N.sub.(n+1) of each adjacent surrounding layer n+1 satisfy the relationship (V.sub.(n+1)−V.sub.n)/V.sub.(n+1)≦(N.sub.(n+1)−N.sub.n)/N.sub.n.

Golf ball having at least three layers comprising ionomeric and/or HNP compositions, wherein for each two adjacent layers, a relationship is established between a ratio of the volumes of the two adjacent layers and a ratio of the percent neutralizations of those two layers such that the volumes and % neutralizations of all layers are interrelated and interdependent to produce unique and desirable playing characteristics. In one embodiment, a golf ball of the invention has T layers, wherein T≧3 and each of T layers has a different volume “V” and comprises an ionomeric and/or HNP composition having a different % neutralization “N”; and wherein each of n inner layers of the T layers (n<T) has an adjacent surrounding layer n+1 such that a volume V.sub.n and a % neutralization N.sub.n of each inner layer and a volume V.sub.(n+1) and % neutralization N.sub.(n+1) of each adjacent surrounding layer n+1 satisfy the relationship (V.sub.(n+1)−V.sub.n)/V.sub.(n+1)≦(N.sub.n−N.sub.(n+1))/N.sub.(n+1).

A golf ball material includes (A) one or more resin ingredient selected from the group consisting of olefin-unsaturated carboxylic acid random copolymers, olefin-unsaturated carboxylic acid-unsaturated carboxylic acid ester random copolymers, and metal ion neutralization products of these copolymers; (D) an amino compound having at least 2 amino groups per molecule; (B) one or more resin ingredient selected from the group consisting of polyethylene, polyesters and polyamide elastomers; and (C) an agent for compatibilizing components (A) and (B). The compatibilizing agent (C) includes: (C-i) two different types of base polymer selected from a specific group, (C-ii) a hydrogenated diene polymer having at least one type of functional moiety selected from a specific group of moieties, and (C-iii) an olefinic polymer having at least one type of functional moiety selected from a specific group of moieties.

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.

The use of a low molecular weight farnesene, poly(farnesene), and farnesene copolymer in a golf ball is disclosed herein. In a core, low molecular weight farnesene, poly(farnesene) or farnesene copolymer is blended with 1,4 polybutadiene or a polyalkenamer. In a mantle layer, low molecular weight farnesene, poly(farnesene), and/or farnesene copolymer can be blended with non- or partially neutralized copolymeric or terpolymeric ionomer(s). In a cover, low molecular weight farnesene, poly(farnesene), and farnesene copolymer can be blended with highly neutralized ionomer.

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.

Method of making a golf ball comprising the steps of: providing a subassembly; forming about the subassembly at least one layer comprised of a thermoset polyurethane which is prepared by mixing as the essential ingredients: (i) at least one long chain soft segment polyol and/or polyamine; (ii) at least one short chain-extending-type species; (iii) at least one isocyanate; and (iv) at least one additional chain-extending-type species; wherein essential ingredients (i) and (ii) are combined (reacted/mixed) to form a first sub-mixture; followed by combining/mixing the first sub-mixture and essential ingredient (iii) to form a prepolymer second sub-mixture; followed by combining (reacting/mixing) the prepolymer second sub-mixture with essential ingredient (iv) to form the thermoset polyurethane. Essential ingredients (ii) and (iv) may differ, or in some embodiments, are the same, although the total amount of essential ingredients (ii) included is preferably greater than the total amount of essential ingredient (iv).

Methods of forming dual core golf ball constructions achieving consistent and repeatable concentricity by incorporating a pair of novel hemispherical shells produced using an inventive center plate button. The pair of resulting novel hemispherical shells may be collectively compression molded about and reliably center a spherical inner core there within due to the novel resulting centering features and structure provided on the inner surface of each hemispherical shell by the novel center plate button used to form same. Securing features and structure are thereby provided within/on inner surfaces of resulting hemispherical shells in order to prevent undesirable movement of the spherical inner core there within until the final compression molding step occurs.