Abstract: 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 (?m) is an arithmetic mean roughness of a surface of a cut plane of the cover, and Spc (mm?1) is an arithmetic mean curvature of a summit of the surface of the cut plane of the cover.

Abstract: 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.

Abstract: A golf club grip having great anti-slipping performance in the material itself constituting the grip includes an outermost surface layer, wherein at least a part of the outermost surface layer is formed from a rubber composition containing (A) a base rubber and (B) a tackifier having a softening point in a range of from 5° C. to 120° C., and a portion formed from the rubber composition has a loss tangent (tan?) (30° C., 10 Hz) and a complex elastic modulus (E*) (30° C., 10 Hz) satisfying a relationship of 0.070?tan?/(E*)02?0.098.

Abstract: An object of the present invention is to provide a cured product of a golf ball rubber composition imparting excellent durability. The present invention provides a cured product of a golf ball rubber composition cured from a golf ball 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) a crosslinking initiator, wherein the cured product of the golf ball rubber composition satisfies the following mathematical formula (1): Y<(0.1×X)?1.30??(1) in the formula (1), Y represents an effective crosslinking density of the cured product of the rubber composition (mmol/cc), and X represents an amount of the component (b) with respect to 100 parts by mass of (a) the base rubber (parts by mass).

Abstract: An object of the present invention is to provide a diene-based polymer that can control the crosslinking morphology. The present invention provides a modified diene-based polymer having a structure represented by the formula (1). [In the formula (1), R1 and R2 represent an alkyl group having 1 or more carbon atoms, an aryl group having 6 or more carbon atoms, an aralkyl group having 6 or more carbon atoms, a hydrogen atom, or a halogen atom; and Z is an organic group, an organic group where a part of hydrogen atom of the above organic group is substituted, a hydrogen atom, or a halogen atom.

Abstract: An object of the present disclosure is to provide a cured product of a golf ball rubber composition imparting excellent durability to a golf ball. The present disclosure provides a cured product of a golf ball 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) a crosslinking initiator, wherein an effective crosslinking density DC (mmol/cm3) of the cured product and a tensile modulus TM of the cured product at a strain (MPa) from 0.05% to 0.25% satisfy a relationship of TM?333.32×ln(DC)>100.

Abstract: An object of the present disclosure is to provide a golf ball having good shot feeling and excellent durability while having non-lowered resilience. The present disclosure provides a golf ball comprising a spherical core and one or more cover layers disposed outside the spherical core, wherein at least one layer of the cover layers contains (A) a base resin and (B) a polyethylene oxide.

Abstract: An object of the present disclosure is to provide a golf club grip comprising an inner layer that is hard to collapse and has excellent weather resistance. The present disclosure provides a golf club grip comprising a cylindrical portion having a cylindrical inner layer and a cylindrical outer layer provided outside the cylindrical inner layer, wherein the cylindrical inner layer is formed from an inner layer rubber composition containing an acrylonitrile-butadiene based rubber as (A1) a base rubber, and the inner layer rubber composition has a maximum torque value of 0.5 Nm or more in a vulcanization curve measured at a temperature of 165° C. and an amplitude angle of one degree.

Abstract: An object of the present invention is to provide a golf ball having excellent shot feeling while maintaining the resilience performance on driver shots. The present invention provides a golf ball comprising a core and at least one cover covering the core, wherein the core is formed from a core 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 monophenol compound having a substituent group only at p-position.

Abstract: An object of the present invention is to provide a production method of a diene-based polymer that can control the crosslinking morphology. The present invention provides a method for producing a modified diene-based polymer having a structure represented by the formula (1), comprising a first step of mixing a diene-based polymer and a dithioester compound to prepare a mixture; and a second step of irradiating a ray to the mixture under an inert atmosphere. [In the formula (1), R1 and R2 represent an alkyl group having 1 or more carbon atoms, an aryl group having 6 or more carbon atoms, an aralkyl group having 6 or more carbon atoms, a hydrogen atom, or a halogen atom; and Z is an organic group, an organic group where a part of hydrogen atom of the above organic group is substituted, a hydrogen atom, or a halogen atom.

Abstract: An object of the present disclosure is to provide a golf ball which has excellent spin performance on approach shots and from which stain such as mud or grass juice can be wiped off when the golf ball has the stain adhered thereto. The present disclosure provides a golf ball comprising a golf ball body and a paint film composed of at least one layer and formed on a surface of the golf ball body, wherein an outermost layer of the paint film includes, as a base resin, a polyurethane obtained by a reaction between a polyisocyanate composition and a polyol composition, the polyol composition contains, as a polyol component, a polyrotaxane having at least two hydroxyl groups and a urethane polyol, and the outermost layer of the paint film has a tackiness of 0.

Abstract: An object of the present disclosure is to provide a rubber composition from which a crosslinked rubber molded product having good softness and excellent resilience performance can be obtained. The present disclosure provides a rubber composition containing (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking initiator, and (d) an organic sulfur compound, wherein (d) the organic sulfur compound includes (d1) a compound represented by the formula (1) and/or (d2) a compound represented by the formula (2).

Abstract: [Problem] To provide a golf club grip having excellent anti-slipping performance, and feeling when the grip is wet, and further to provide a golf club grip having excellent durability and an improved head speed. [Solution] The golf club grip comprises a cylindrical portion for inserting a shaft, wherein the golf club grip has a narrow groove region comprising narrow grooves in an occupation ratio of 35% or more per 25 mm2 at at least a part of a surface of the cylindrical portion, and the narrow groove has a width (w) of from 0.1 mm to 0.7 mm and a depth (h) of from 0.1 mm to 1.0 mm. In addition, an interval (d) between the narrow grooves are preferably 1.5 mm or less.

Abstract: An object of the present disclosure is to provide a golf ball having an increased spin rate when being hit with an 8-iron while suppressing rise in a spin rate when being hit with a driver. The present disclosure provides a golf ball comprising a spherical core having an inner core and an outer core, and a cover positioned outside the spherical core, wherein A×a is 12,200 or less and B×b is 20,400 or more, where “a” represents an average hardness (Shore C) of a hardness (H2.5) at a point of 2.5 mm from a center of the spherical core and a hardness (H5) at a point of 5 mm from the center of the spherical core, “b” represents an average hardness (Shore C) of a hardness (H7.5) at a point of 7.

Abstract: An object of the present invention is to provide a novel golf ball having excellent spin performance on approach shots. The present invention provides a golf ball comprising a golf ball body and a paint film composed of at least one layer and formed on a surface of the golf ball body, wherein a base resin constituting an outermost layer of the paint film is a polyurethane obtained by a reaction between (A) a polyol composition and (B) a polyisocyanate composition, and a loss modulus (E?) at the temperature of ?50° C. obtained by measuring a dynamic viscoelasticity of the polyurethane is 1.00×108 Pa or more.

Abstract: An object of the present invention is to provide a novel golf ball having excellent spin performance on approach shots. The present invention provides a golf ball comprising a golf ball body, and a paint film formed on a surface of the golf ball body and composed of at least one layer, wherein a base resin constituting an outermost layer of the paint film includes a polyurethane, and the polyurethane has a loss elastic modulus (E?) of 0.2×108 Pa or more at ?50° C. and a loss tangent (tan ?) having a peak temperature of 0° C. or less, obtained by measuring dynamic viscoelasticity of the polyurethane under specific conditions.

Abstract: 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 (?m) is an arithmetic mean roughness of a surface of a cut plane of the cover, and Spc (mm?1) is an arithmetic mean curvature of a summit of the surface of the cut plane of the cover.

Abstract: 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 ?m or more.

Abstract: An object of the present disclosure is to provide a rubber composition containing an organic sulfur compound from which a molded product having a high hardness can be obtained. The present disclosure provides a rubber composition containing (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking initiator, (d) a benzothiazole derivative, and (e) an organic sulfur compound, wherein (d) the benzothiazole derivative is a compound represented by the formula (1) and/or a compound represented by the formula (2). [R1 represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group having 4 to 14 carbon atoms, or a metal atom, R2 to R5 are identical to or different from each other, and represent an electron-withdrawing group or a hydrogen atom, and at least one of R3 to R5 is an electron-withdrawing group.

Abstract: An object of the present invention is to provide a golf ball having excellent durability and good shot feeling. The present invention provides a golf ball comprising a core, wherein a difference (crosslinking density at surface of core-crosslinking density at center of core) between a crosslinking density at a surface of the core and a crosslinking density at a center of the core is more than 1.0×102 mol/m3 and less than 9.0×102 mol/m3, and a hardness difference (Hs?Ho) between Hs and Ho is 13.0 or more and 30.0 or less, and the core satisfies H50?Ho>Hs?H50, wherein Hs (Shore C hardness) is a hardness at the surface of the core, Ho (Shore C hardness) is a hardness at the center of the core, and H50 (Shore C hardness) is a hardness at a midpoint between the center of the core and the surface of the core.