In a golf ball having a core, a cover of at least one layer and a paint film layer formed on a surface of the cover, the paint film layer has an elastic work recovery of at least 60%, the cover layer in contact with the paint film layer has a material hardness on the Shore D scale of at least 55 and, letting M be the elastic work recovery (%) of the paint film layer and N be the material hardness (Shore D hardness) of the cover layer, MN>0. The ball surface is scratch-resistant and has an excellent durability, and the ball has a reduced spin rate on shots with a driver or a long iron, resulting in an increased carry.

An object of the present invention is to provide a golf ball having excellent resilience. The present invention provides a golf ball comprising a spherical core and at least one cover covering the spherical core, wherein the spherical core is formed from a rubber composition containing (a) a base rubber, and (b) a co-crosslinking agent containing (b1) a carboxylic acid represented by a structural formula (1) and/or a metal salt thereof.

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[In the formula (1), A.sup.1 to A.sup.4 each independently represents a nitrogen atom or a carbon atom. X.sup.1 represents a single bond or a divalent organic group. R.sup.1 represents a hydrogen atom or a monovalent organic group. It is noted that at least one of A.sup.1 to A.sup.4 is the carbon atom, and X.sup.1 and R.sup.1 bond to the carbon atom. n represents an integer of 0 to 3. When n is 2 or more, a plurality of R.sup.1 may be identical to or different from each other, and a plurality of R.sup.1 may bond to each other to form a ring structure.]

A method and system for determining concentricity of a multiple layer golf ball are disclosed herein. One or more images of a golf ball are generated using an X-ray source, a camera or a digital detector, and an image intensifier. An edge detection algorithm is preferably utilized. The method also includes calculating Y,Z center coordinates of the a best fit diameter or ellipse of the inner edge layer and outer edge layer of the multiple layer golf ball.

An object of the present disclosure is to provide a rubber composition from which a crosslinked rubber molded product having excellent resilience performance can be obtained. The present disclosure 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 includes (b1) a metal complex, and (b1) the metal complex is composed of (b11) a metal component, (b12) a ligand derived from an ?,?-unsaturated carboxylic acid compound having 3 to 8 carbon atoms, and (b13) a ligand derived from a mercaptobenzothiazole-based compound.

A golf ball comprising an inner core comprising polybutadiene, and an outer core comprising a polybutadiene material, a graphene material and a carbon nanotube material (CNT) is disclosed herein. Improved durability of the core by using a mixture of graphene and CNT can result in higher mean time to fail (MTTF) upon repeated impact in a high speed testing device, or with a golf club in normal play.

In order to satisfy at a high level the golf ball flight and control performances relied on by professional golfers and skilled amateurs, this invention provides a multi-piece solid golf ball G having a core 1, a cover 3 and an intermediate layer 2 therebetween wherein the core is formed of a rubber composition that includes a lower alcohol having a molecular weight below 200. Also, letting Hc be the JIS-C hardness at the center of the core, H12 be the JIS-C hardness at a position 12 mm from the core center and Ho be the JIS-C hardness at the surface of the core, the core has a hardness profile in which these hardnesses satisfy fixed relationships defined by specific formulas.

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 ?,?-unsaturated carboxylic acid of 3 to 8 carbons and/or a ternary copolymer of an olefin, an ?,?-unsaturated carboxylic acid of 3 to 8 carbons and an ester of the ?,?-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 comprising a core comprising an inner core center and an outer core layer disposed over the inner core center. The inner core center has a deflection of greater than 0.210 inch under a load of 100 kilograms, and the entire the core has a deflection ranging from 0.130 inch to 0.105 inch under a load of 100 kilograms. A mantle layer is disposed over the core and a cover is disposed over the mantle.

Multi-layered golf balls having at least one layer made of a polyester composition containing a polyester thermoplastic elastomer and plasticizer are provided. The plasticizers help reduce the glass transition temperature (Tg) of the composition and various plasticizers may be used. For example, the composition may include alkyl oleate plasticizers such as ethyl oleate and octyl oleate. Polyester-ether block copolymers are particularly preferred. The golf ball includes a core having at least one layer and a cover having at least one layer. The polyester composition may be used to form any core, cover, or other layer in the golf ball.

Methods of reclaiming resources from finished golf balls and incorporating the reclaimed resources into a manufacturing process for making golf balls or components of golf balls.