Abstract: An object of the present invention is to provide a golf ball traveling a great distance of a driver shot. The present invention provides a golf ball having a spherical core and at least one cover layer covering the spherical core, wherein the spherical core is formed from a rubber composition containing (a) a base rubber, (b) an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof as a co-crosslinking agent, (c) a crosslinking initiator, (d) a carboxylic acid and/or a salt thereof, and (e) an organic sulfur compound having a naphthalene ring, provided that the rubber composition further contains (e) a metal compound in the case of containing only (b) the ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms as the co-crosslinking agent.

Abstract: An object of the present invention is to provide a golf ball showing a low spin rate on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover layer covering the spherical core, wherein the spherical core is formed from a rubber composition containing (a) a base rubber, (b) an ?,?-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 carboxylic acid having a heterocyclic ring and/or a salt thereof, provided that the rubber composition further contains (e) a metal compound in case of containing only (b) the ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms as the co-crosslinking agent.

Abstract: An object of the present invention is to provide a golf club grip showing a good feeling both at hitting and at waggling. The present invention provides a golf club grip comprising a cylindrical portion for inserting a shaft, wherein the cylindrical portion has a compression strain in a range from 46% to 55% at a compression stress of 20 kg/cm2, and a compression strain in a range from 63% to 69% at a compression stress of 120 kg/cm2.

Abstract: An object of the present invention is to provide a grip for sporting goods excellent in tensile strength and having a light weight. The present invention provides a grip for sporting goods comprising a cylindrical portion composed of a cylindrical inner layer and a cylindrical outer layer covering the cylindrical inner layer, wherein the cylindrical inner layer is a porous rubber layer or a porous resin layer, and the cylindrical outer layer is formed from a rubber composition containing an acrylonitrile-butadiene based rubber.

Abstract: An object of the present invention is to provide a golf club grip comprising a layer containing a polar rubber and a layer containing a nonpolar rubber, and excellent in tensile strength. The present invention provides a golf club grip comprising a polar rubber layer and a nonpolar rubber layer, wherein the polar rubber layer is formed from a rubber composition containing a base rubber including a polar rubber in an amount of 50 mass % or more, the nonpolar rubber layer is formed from a rubber composition containing a base rubber including a nonpolar rubber in an amount of 50 mass % or more, the polar rubber layer and the nonpolar rubber layer are laminated via an interlayer formed from an interlayer composition containing an olefin rubber.

Abstract: A golf ball, showing a lower spin rate and a greater flight distance on driver shots by controlling a hardness distribution of the spherical core thereof, comprises a spherical core and at least one cover layer covering the spherical core. The spherical core is formed from a rubber composition containing (a) a base rubber, (b) an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof as a co-crosslinking agent, (c) a crosslinking initiator, (d1) a salt of a carboxylic acid having 1 to 4 carbon atoms, or an aromatic carboxylic acid and/or a salt thereof, and (d2) at least one compound selected from the group consisting of an aliphatic carboxylic acid having 5 or more carbon atoms, a salt of an aliphatic carboxylic acid having 5 or more carbon atoms, thiobenzoic acids, salts of thiobenzoic acids, a mercaptocarboxylic acid derivative and a dithiodicarboxylic acid derivative.

Abstract: An object of the present invention is to provide a golf ball showing a great flight distance on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover layer covering the spherical core, wherein the spherical core is formed from a rubber composition containing (a) base rubber, (b) an ?,?-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 branched carboxylic acid and/or a salt thereof, provided that the rubber composition further contains (e) a metal compound in case of containing only (b) the ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms as the co-crosslinking agent.

Abstract: An object of the present invention is to provide a golf ball showing a low spin rate on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover layer covering the spherical core, wherein the spherical core is formed from a rubber composition containing (a) a base rubber, (b) an ?,?-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 carboxylic acid having a heterocyclic ring and/or a salt thereof, provided that the rubber composition further contains (e) a metal compound in case of containing only (b) the ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms as the co-crosslinking agent.

Abstract: An object of the present invention is to provide a golf ball showing a great flight distance on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover layer covering the spherical core, wherein the spherical core is formed from a rubber composition containing (a) base rubber, (b) an ?,?-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 mercaptocarboxylic acid derivative and/or a dithiodicarboxylic acid derivative.

Abstract: An object of the present invention is to provide a golf ball having a low spin rate on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover layer covering the spherical core, wherein the spherical core is formed from a rubber composition containing (a) base rubber, (b) an ?,?-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 carboxylic acid having a benzene ring and/or a salt thereof, provided that the rubber composition further contains (e) a metal compound in case of containing only (b) the ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms as the co-crosslinking agent.

Abstract: An object of the present invention is to provide a golf club grip excellent in grip performance in a wet condition. The present invention provides a golf club grip formed from a rubber composition comprising a base rubber and a crosslinking agent, wherein the base rubber comprises a hydrogenated acrylonitrile-butadiene rubber and/or a carboxyl-modified acrylonitrile-butadiene rubber.

Abstract: An object of the present invention is to provide a golf ball having a low spin rate on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover layer covering the spherical core, wherein the spherical core is formed from a rubber composition containing (a) base rubber, (b) an ?,?-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 carboxylic acid having a benzene ring and/or a salt thereof, provided that the rubber composition further contains (e) a metal compound in case of containing only (b) the ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms as the co-crosslinking agent.

Abstract: An object of the present invention is to provide a golf ball traveling a great flight distance on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover layer covering the spherical core, wherein the spherical core is formed from a rubber composition containing (a) base rubber, (b) an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof as a co-crosslinking agent, (c) a crosslinking initiator, (d) a carboxylic acid having 1 to 14 carbon atoms and/or a salt thereof, and (e) a halogen-substituted thiophenol and/or a metal salt thereof as an organic sulfur compound, provided that the rubber composition further contains (f) a metal compound in the case of containing only (b) the ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms as the co-crosslinking agent.

Abstract: An object of the present invention is to provide a golf ball traveling a great distance on driver shots. The present invention provides a golf ball comprising a constituting member formed from a rubber composition containing (a) a base rubber, (b) an ?, ?-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof as a co-crosslinking agent, and (c) an crosslinking initiator, wherein (b) the ?, ?-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or the metal salt thereof meets the following conditions (1) and (2) in a volume based distribution, when measuring a particle size thereof with a laser diffraction particle size analyzer; (1) a mode particle size is more than 10 ?m and 50 ?m or less, and (2) a volume ratio of particles having a particle size ranging from 6 ?m to 300 ?m is 60% or more.

Abstract: The present invention provides a golf ball comprising a spherical core and at least one cover layer covering the spherical core, wherein the cover is formed from a polyurethane composition containing a polyurethane elastomer as a resin component, the polyurethane composition satisfying properties of rebound resilience of 54% or more and a shear loss modulus G? of 5.03×106 Pa or less when measured in a shear mode using a dynamic viscoelasticity measuring apparatus at the conditions of the temperature of 0° C., and the oscillation frequency of 10 Hz, and the spherical core has a hardness distribution that R2 of a linear approximate curve determined by a least-squares method is 0.95 or more, when plotting JIS-C hardness measured at a center, a surface and at intervals of 2.5 mm from the center of the spherical core, versus distances from the center of the spherical core.

Abstract: A golf ball includes a spherical core and a cover covering the spherical core, wherein the cover is formed from a polyurethane composition containing a polyurethane elastomer as a resin component, the polyurethane composition has a shear loss modulus G? of more than 5.03×106 Pa and 1.17×108 Pa or less when measured in a shear mode using a dynamic viscoelasticity measuring apparatus at the conditions of the temperature of 0° C., and the oscillation frequency of 10 Hz, the golf ball has a hardness distribution that R2 of a linear approximate curve determined by a least-squares method is 0.95 or more, when plotting center hardness (JIS-C) of the spherical core, hardness (JIS-C) measured at intervals of 2.5 mm from the center of the spherical core, surface hardness (JIS-C) of the spherical core, and slab hardness (JIS-C) of the cover versus distances from the center of the spherical core.

Abstract: An object of the present invention is to provide a golf ball showing a low spin rate on driver shots and an excellent shot feeing. The present invention provides a golf ball having 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, (b) an ?,?-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 at least one compound of (d) mercaptobenzoic acids and/or salts thereof, provided that the rubber composition further contains (e) a metal compound in the case of containing only (b) the ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms as the co-crosslinking agent, and the spherical core has a hardness difference (Hs—Ho) between a surface hardness (Hs) and a center hardness (Ho) thereof of 20 or more in JIS-C hardness.

Abstract: An object of the present invention is to provide a golf ball showing a great flight distance on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover layer covering the spherical core, wherein when JIS-C hardness of the spherical core is measured at points located at distances of 0% (core center), 37.5%, 75.0% and 100% (core surface) from the core center of the spherical core, a hardness difference (Hs?Ho) between a surface hardness (Hs) thereof and a center hardness (Ho) thereof is 20 or more, a ratio ((H37.5?Ho)/(H75.0?Ho)) of a hardness difference (H37.5?Ho) to a hardness difference (H75.0?Ho) is 0.6 or less, and a compression deformation amount (D (mm)) of the spherical core and the 37.5% point hardness (H37.5) satisfy a relation of H37.5??9×D+95.

Abstract: A method for manufacturing a golf ball showing a great flight distance on driver shots for includes the steps of: preparing a rubber composition containing a base rubber, an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof as a co-crosslinking agent, a crosslinking initiator and a carboxylic acid and/or a salt thereof; heat pressing the rubber composition at a press temperature ranging from t-40° C. to t-15° C. to mold a spherical core, wherein t ° C. is a one-minute half-life temperature of the crosslinking initiator; and forming at least one cover layer covering the spherical core.

Abstract: A method for manufacturing a golf ball showing a great flight distance on driver shots for includes the steps of: preparing a rubber composition containing a base rubber, an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof as a co-crosslinking agent, a crosslinking initiator and a carboxylic acid and/or a salt thereof; heat pressing the rubber composition at a press temperature ranging from t-40° C. to t-15° C. to mold a spherical core, wherein t ° C. is a one-minute half-life temperature of the crosslinking initiator; and forming at least one cover layer covering the spherical core.