A resin composition for golf balls includes (a) an acid-containing copolymer having an amount of acid constituent per 100 wt % of the sum of monomer units in the copolymer that is from 1 to 30 wt %, and (b) an amine-containing polymer having a branched structure. The resin composition imparts golf balls with an excellent rebound resilience and also confers an outstanding durability to repeated impact and an outstanding scuff resistance, making it particularly useful as a cover material in golf balls.

A golf ball material contains (I) a multi-component copolymer having conjugated diene units, non-conjugated olefin units and aromatic vinyl units; and (II) a binary copolymer of an olefin and an α,β-unsaturated carboxylic acid of 3 to 8 carbons and/or a ternary copolymer of an olefin, an α,β-unsaturated carboxylic acid of 3 to 8 carbons and an ester of the α,β-unsaturated carboxylic acid, or a metal neutralization product thereof.

The conjugated diene units include butadiene units, the non-conjugated olefin units include units selected from the group consisting of ethylene, propylene and 1-butene units, and the aromatic vinyl units include styrene units. The content of the conjugated diene units in the multi-component copolymer (I) is 5 wt % or more. This golf ball material is soft and has an excellent rebound resilience. Golf balls which use this material in the cover provide golfers with a competitive edge.

A golf ball core, mantle, and/or cover layer(s) of golf ball having a composition comprising functionalized aluminosilicate particles having a particle size of less than 50 μm is disclosed herein. The aluminosilicate microspheres with an average diameter less than 50 μm are functionalized with, but not limited to, polysulfide, vinyl, amino, epoxy, hydroxyl, carboxyl, methacryloyl, hydrocarbon, mercapto and isocyanate.

In a golf ball having a rubber core of at least one layer and a cover of at least one layer encasing the core, at least one layer of the cover is formed of a resin composition that includes (I) a polyurethane or a polyurea and (II) a (meth)acrylic block copolymer, the (meth)acrylic block copolymer serving as component (II) being included in an amount of 20 parts by weight or less per 100 parts by weight of component (I). The golf ball has an excellent controllability on approach shots and is able to maintain a good scuff resistance and moldability.

A golf ball comprising layers that have from 0.05% to 70% by weight of a radio-opaque filler, and wherein the concentration of the radio-opaque filler is measurably different in each layer is disclosed herein. The radio-opaque filler is preferably a compound based on barium, bismuth, tungsten, iodine, or reduced iron.

Multi-layered golf balls having at least one layer made of a foamed silicone composition are provided. Multi-layered golf balls having at least one layer made of non-foamed silicone elastomer composition also are provided. For example, three-piece, four-piece, and five-piece golf balls containing different core and cover structures can be made. The foamed silicones have good thermal stability and durability without sacrificing resiliency. The non-foamed silicone elastomers have high elongation, tensile strength, chemical/fluid-resistance, and weatherability properties. These compositions can be used to form any layer, for example, core, intermediate, or cover, in the golf ball.

Provided are novel ethylene acid copolymers, their ionomers and their use in various articles, including packaging films and injection molded articles. The ethylene acid copolymers comprise copolymerized units of ethylene, about 10 to about 30 wt % of copolymerized units of a first α,β-unsaturated carboxylic acid having 3 to 10 carbon atoms; and about 5 to about 15 wt % of copolymerized units of a derivative of a second α,β-unsaturated carboxylic acid having 3 to 10 carbon atoms. Preferred derivatives include esters, and in particular alkyl esters. These ethylene acid copolymers and ionomers have improved optical properties when compared to conventional ethylene acrylic or methacrylic acid copolymers and their ionomers.

In a golf ball having a core and a cover of one or a plurality of layers that encases the core, the core or at least one layer of the cover is formed of a resin composition which contains from 5 to 250 parts by weight of a mechanoluminescent material that receives mechanical energy and luminesces per 100 parts by weight of a base material which is a rubber material or a resin material. This golf ball has an excellent visibility in that, even under dark conditions, the ball impact site can be clearly confirmed visually at the time of impact. Moreover, the ball is able to maintain a good scuff resistance.

An object of the present disclosure is to provide a golf ball having good shot feeling and excellent durability and not having lowered resilience even if a hard cover material is used. The present disclosure provides a golf ball comprising a spherical core, and a cover disposed outside the spherical core and composed of one or more layers, wherein at least one cover layer contains (A) a base resin, and (B) at least one member selected from the group consisting of a polyrotaxane, a polyethylene oxide, a polypropylene oxide, a polycaprolactone and a liquid polymer, and Sa×Spc≥100 wherein Sa (μm) is an arithmetic mean roughness of a surface of a cut plane of the cover, and Spc (mm.sup.−1) is an arithmetic mean curvature of a summit of the surface of the cut plane of the cover.

An object of the present invention is to provide a golf ball having excellent color development stability. The present invention provides a golf ball comprising a core and a cover covering the core, wherein the cover is formed from a resin composition containing a first base resin and a fluorescent pigment, and the fluorescent pigment has a number-based cumulative median size of 2.5 μm or more.