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 T3 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.nN.sub.(n+1))/N.sub.(n+1).

The present invention relates to the use of a mono (meth)acrylate ester in a golf ball layer. The mono (meth)acrylate ester may be added to one or more portions of a golf ball including a core, intermediate, or cover layer. For example, in one embodiment, the mono (meth)acrylate ester may be blended with a polybutadiene rubber material. In another embodiment, the mono (meth)acrylate ester of the present invention may be blended with an ionomer. In some embodiments, the mono (meth)acrylate ester may be blended with a formulation including both a polybutadiene rubber component and an ionomer.

Multi-piece golf balls having a multi-layered solid core and multi-layered cover are provided.

Multi-piece golf balls having a multi-layered solid core and multi-layered cover are provided.

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 comprising an inner core layer including a thermoplastic material and having a geometric center hardness less than the surface hardness to define a positive hardness gradient. An outer core layer is formed over the inner core. The outer core includes a thermoset rubber composition and has an inner surface hardness less than an outer surface hardness to define a positive hardness gradient. A cover layer is formed over the outer core layer. The cover layer includes an inner cover layer and an outer cover layer. The thermoplastic material of the core includes an acid copolymer of ethylene and an ,-unsaturated carboxylic acid, optionally a softening monomer comprising alkyl acrylate or methacrylate; a plasticizer; an organic acid or salt thereof; and a cation source present in an amount sufficient to neutralize from about 70 to about 100% of all acid groups present in the material.

Multi-piece golf balls having a multi-layered solid core and multi-layered cover are provided.

Multi-piece golf balls having a multi-layered solid core and multi-layered cover are provided.

An object of the present invention is to provide a rubber composition from which a crosslinked rubber molded product excellent in the resilience performance can be obtained. The present invention provides a rubber composition containing (a) a base rubber, (b) a co-crosslinking agent and (c) a crosslinking initiator, wherein (b) the co-crosslinking agent contains a complex represented by a general formula (1).

((RCOO).sub.8M.sub.5(OH).sub.2).sub.n (1)

[In the formula (1), M is a metal atom, R is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms or an alkynyl group having 2 to 18 carbon atoms, and n is an integer of 1 or more. A plurality of R and M may be identical to or different from each other. At least one of R is the alkenyl group having 2 to 18 carbon atoms or the alkynyl group having 2 to 18 carbon atoms.]