Abstract: An object of the present invention is to provide a golf ball having an excellent flight performance on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover covering the spherical core, wherein a hardness difference D1 (H75?H0) between a hardness H75 at a point radially located at a distance of 75% from a center of the spherical core and a center hardness H0 of the spherical core is 10 or more and 27 or less in Shore C hardness, and a hardness difference D2 (Hs?H75) between a surface hardness Hs of the spherical core and the hardness H75 at the point radially located at the distance of 75% from the center of the spherical core is 0 or more and 6.5 or less in Shore C hardness.

Abstract: An object of the present invention is to provide a novel complex having at least one carbon-carbon double bond and/or carbon-carbon triple bond, and having at least one Diels-Alder reactive functional group such as tetrazine. The present invention provides a complex represented by a formula (1): [M4O(RCOO)6]p??(1) wherein in the formula (1), at least one of R is an alkenyl group having 2 to 18 carbon atoms or an alkynyl group having 2 to 18 carbon atoms, and at least one of R is a monovalent group represented by a structural formula (2), wherein in the structural formula (2), A1 to A4 each independently represent a nitrogen atom or a carbon atom, X1 represents a single bond or a divalent organic group, and R1 represents a hydrogen atom or a monovalent organic group.

Abstract: An object of the present invention is to provide a novel complex having at least two carbon-carbon double bonds and/or carbon-carbon triple bonds. The present invention provides a complex represented by a structural formula (2): [In the structural formula (2), M1 to M4 are identical to or different from each other and represent a metal atom, R1 to R6 are identical to or different from each other and represent a hydrogen atom, an alkyl group having 1 to 24 carbon atoms, an alkenyl group having 2 to 18 carbon atoms or an alkynyl group having 2 to 18 carbon atoms, at least two of R1 to R6 are the alkenyl group having 2 to 18 carbon atoms or the alkynyl group having 2 to 18 carbon atoms, and at least one of R1 to R6 is the alkyl group having 6 to 24 carbon atoms].

Abstract: 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. [In the formula (1), A1 to A4 each independently represents a nitrogen atom or a carbon atom. X1 represents a single bond or a divalent organic group. R1 represents a hydrogen atom or a monovalent organic group. It is noted that at least one of A1 to A4 is the carbon atom, and X1 and R1 bond to the carbon atom. n represents an integer of 0 to 3. When n is 2 or more, a plurality of R1 may be identical to or different from each other, and a plurality of R1 may bond to each other to form a ring structure.

Abstract: A golf ball includes a spherical core, and a cover covering the spherical core. The spherical core is formed from a rubber composition including a base rubber, a co-cross-linking agent, a cross-linking initiator, and an unsaturated fatty acid and/or a metal salt thereof, the co-cross-linking agent includes ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof, the unsaturated fatty acid and/or metal salt thereof excludes an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms and a metal salt thereof, an unsaturated aliphatic carboxylic acid that forms the unsaturated fatty acid and/or metal salt thereof has a functional group other than a carboxy group and a carbon-carbon unsaturated bond, and the rubber composition further includes a metal compound when the co-cross-linking agent is only an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms.

Abstract: 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. [In the formula (1), A1 to A4 each independently represents a nitrogen atom or a carbon atom. X1 represents a single bond or a divalent organic group. R1 represents a hydrogen atom or a monovalent organic group. It is noted that at least one of A1 to A4 is the carbon atom, and X1 and R1 bond to the carbon atom. n represents an integer of 0 to 3. When n is 2 or more, a plurality of R1 may be identical to or different from each other, and a plurality of R1 may bond to each other to form a ring structure.

Abstract: An object of the present invention is to provide a novel complex having at least one carbon-carbon double bond and/or carbon-carbon triple bond, and having at least one Diels-Alder reactive functional group such as tetrazine. The present invention provides a complex represented by a formula (1): [M4O(RCOO)6]p??(1) wherein in the formula (1), at least one of R is an alkenyl group having 2 to 18 carbon atoms or an alkynyl group having 2 to 18 carbon atoms, and at least one of R is a monovalent group represented by a structural formula (2), wherein in the structural formula (2), A1 to A4 each independently represent a nitrogen atom or a carbon atom, X1 represents a single bond or a divalent organic group, and R1 represents a hydrogen atom or a monovalent organic group.

Abstract: An object of the present invention is to provide a novel complex having at least two carbon-carbon double bonds and/or carbon-carbon triple bonds. The present invention provides a complex represented by a structural formula (2): [In the structural formula (2), M1 to M4 are identical to or different from each other and represent a metal atom, R1 to R6 are identical to or different from each other and represent a hydrogen atom, an alkyl group having 1 to 24 carbon atoms, an alkenyl group having 2 to 18 carbon atoms or an alkynyl group having 2 to 18 carbon atoms, at least two of R1 to R6 are the alkenyl group having 2 to 18 carbon atoms or the alkynyl group having 2 to 18 carbon atoms, and at least one of R1 to R6 is the alkyl group having 6 to 24 carbon atoms].

Abstract: An object of the present invention is to provide a golf ball having an excellent flight performance on driver shots. 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, (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) an unsaturated fatty acid and/or a metal salt thereof excluding an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof, and provided that the rubber composition further contains (f) a metal compound if only an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms is present as (b) the co-crosslinking agent.

Abstract: An object of the present invention is to provide a grip for sporting goods containing an acrylonitrile-butadiene based rubber as a base rubber and having an excellent grip performance and sustainability of grip performance under a wet condition. The present invention provides a grip for sporting goods comprising an outermost surface layer formed from a surface layer rubber composition, wherein the surface layer rubber composition contains (A) a base rubber and (B) a resin having a softening point in a range from 5° C. to 120° C., (A) the base rubber contains an acrylonitrile-butadiene based rubber, and (B) the resin is at least one type selected from the group consisting of a hydrogenated rosin ester, a disproportionated rosin ester, an ethylene-vinyl acetate copolymer, a coumarone resin, a phenol resin, a xylene resin and a styrene resin.

Abstract: An object of the present invention is to provide a golf ball excellent in flying performance, in particular, to provide a golf ball traveling a great flight distance. 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, and (d1) an aromatic carboxylic acid or (d2) an aromatic carboxylic acid salt, 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 having excellent resilience performance. The present invention provides a golf ball having a spherical core and at least one cover layer, 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, and (c) a crosslinking initiator, provided that the rubber composition further contains (d) 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, wherein (c) the crosslinking initiator includes a peroxy ketal represented by the formula (1), and substituents represented by R1 and R2 have a bond dissociation energy of 435 KJ/mol or more.

Abstract: An object of the present invention is to provide a golf ball having an excellent flight performance on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover covering the spherical core, wherein a hardness difference D1 (H75?H0) between a hardness H75 at a point located at a distance of 75% of a core radius from a center of the spherical core and a center hardness H0 of the spherical core is 15 or more and 35 or less in Shore C hardness, a hardness difference D2 (Hs?H75) between a surface hardness Hs of the spherical core and the hardness H75 at the point located at the distance of 75% of the core radius from the center of the spherical core is ?1 or more and 3.5 or less in Shore C hardness, and a hardness difference D3 ((H0+H75)/2?H37.5) between a hardness of (the center hardness H0 of the spherical core+the hardness H75 at the point located at the distance of 75% of the core radius from the center of the spherical core)/2 and a hardness H37.

Abstract: An object of the present invention is to provide a golf ball having excellent flying performance on driver shots. 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) an unsaturated fatty acid and/or a metal salt thereof (excluding an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof), and (e) a saturated fatty acid and/or a metal salt thereof, 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 club grip having excellent adhesion between the grip body and the grip end thereof, and excellent durability. The present invention provides a golf club grip comprising a cylindrical grip body having a cylindrical inner layer and a cylindrical outer layer covering the cylindrical inner layer, and a grip end provided on an butt side end of the cylindrical grip body, wherein the cylindrical outer layer is interposed in at least a part of a space between a butt side end edge of the cylindrical inner layer and the grip end.

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 has a difference between absorbance of the absorption peak appeared at 1560±30 cm?1 at a surface thereof and absorbance of the absorption peak appeared at 1560±30 cm?1 at a center thereof of 0.024 or more, when measuring the spherical core with a Fourier transform infrared spectrophotometer.

Abstract: An object of the present invention is to provide a golf ball having an excellent flight performance on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover covering the spherical core, wherein a hardness difference D1 (H75?H0) between a hardness H75 at a point located at a distance of 75% of a core radius from a center of the spherical core and a center hardness H0 of the spherical core is 15 or more and 35 or less in Shore C hardness, a hardness difference D2 (Hs?H75) between a surface hardness Hs of the spherical core and the hardness H75 at the point located at the distance of 75% of the core radius from the center of the spherical core is ?1 or more and 3.5 or less in Shore C hardness, and a hardness difference D3 ((H0+H75)/2?H37.5) between a hardness of (the center hardness H0 of the spherical core+the hardness H75 at the point located at the distance of 75% of the core radius from the center of the spherical core)/2 and a hardness H37.

Abstract: A golf ball includes a spherical core, and a cover covering the spherical core. The spherical core is formed from a rubber composition including a base rubber, a co-cross-linking agent, a cross-linking initiator, and an unsaturated fatty acid and/or a metal salt thereof, the co-cross-linking agent includes ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof, the unsaturated fatty acid and/or metal salt thereof excludes an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms and a metal salt thereof, an unsaturated aliphatic carboxylic acid that forms the unsaturated fatty acid and/or metal salt thereof has a functional group other than a carboxy group and a carbon-carbon unsaturated bond, and the rubber composition further includes a metal compound when the co-cross-linking agent is only an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms.

Abstract: An object of the present invention is to provide a golf ball having an excellent flight performance on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover covering the spherical core, wherein a hardness difference D1 (H75?H0) between a hardness H75 at a point radially located at a distance of 75% from a center of the spherical core and a center hardness H0 of the spherical core is 10 or more and 27 or less in Shore C hardness, and a hardness difference D2 (Hs?H75) between a surface hardness Hs of the spherical core and the hardness H75 at the point radially located at the distance of 75% from the center of the spherical core is 0 or more and 6.5 or less in Shore C hardness.

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.