A thermoplastic elastomer composition possessing a good combination of elastic recovery, tear strength at 25° C., stress relaxation and reduced (improved) anisotropy, which is based on a hydrogenated block copolymer (A), a thermoplastic resin (B), a rubber softener (C) and a polyolefin elastomer (D), of specified types and proportions, and which is suitable for use in a variety of film and sheet applications.

An object of the present invention is to provide a golf ball having a decreased 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) a compound represented by the formula (1) as a co-crosslinking agent, and (c) a crosslinking initiator,
(R.sup.1COO)M(OCOR.sup.2)m  (1) in the formula (1), M represents a metal atom, m represents 1 or 2, R.sup.1 and R.sup.2 are different from each other, represent an alkenyl group having 2 to 30 carbon atoms or an alkynyl group having 2 to 30 carbon atoms and have a carbon-carbon double bond or a carbon-carbon triple bond at an α-position carbon atom bonding to the carbonyl group, and when m is 2, two of R.sup.2 may be identical to or different from each other.

An object of the present invention is to provide a golf ball having a decreased 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) a compound represented by the formula (1) as a co-crosslinking agent, and (c) a crosslinking initiator,
(R.sup.1COO)M(OCOR.sup.2)m  (1) in the formula (1), M represents a metal atom, m represents 1 or 2, R.sup.1 and R.sup.2 are different from each other, represent an alkenyl group having 2 to 30 carbon atoms or an alkynyl group having 2 to 30 carbon atoms and have a carbon-carbon double bond or a carbon-carbon triple bond at an α-position carbon atom bonding to the carbonyl group, and when m is 2, two of R.sup.2 may be identical to or different from each other.

The invention relates to a process which responds to this problem scenario. The invention therefore relates to a process for preparing a rubber composition based on at least one diene elastomer, a reinforcing filler, a crumb rubber and a crosslinking system, said process comprising at least the following steps: incorporating the reinforcing filler into the diene elastomer, all at once or in several stages, and mixing; when the temperature of the mixture reaches a temperature of greater than 100° C., adding the crumb rubber; continuing the mixing up to a maximum temperature of between 120° C. and 190° C.; cooling the mixture to a temperature of less than 100° C.; incorporating the crosslinking system and mixing up to a maximum temperature of less than 110° C.

The invention relates to a process which responds to this problem scenario. The invention therefore relates to a process for preparing a rubber composition based on at least one diene elastomer, a reinforcing filler, a crumb rubber and a crosslinking system, said process comprising at least the following steps: incorporating the reinforcing filler into the diene elastomer, all at once or in several stages, and mixing; when the temperature of the mixture reaches a temperature of greater than 100° C., adding the crumb rubber; continuing the mixing up to a maximum temperature of between 120° C. and 190° C.; cooling the mixture to a temperature of less than 100° C.; incorporating the crosslinking system and mixing up to a maximum temperature of less than 110° C.

A curable composition includes an olefin-aromatic vinyl compound-aromatic polyene copolymer satisfying conditions (1) to (4) and an additive resin, which is at least one of a hydrocarbon-based elastomer, polyphenylene ether, olefin-aromatic vinyl compound-aromatic polyene copolymerized oligomer, and aromatic polyene-based resin. (1) The number average molecular weight of the copolymer is 5000 to 100000. (2) The aromatic vinyl compound monomer has 8 to 20 carbon atoms, and the content of the unit of the monomer is 0 to 70 mass %. (3) The aromatic polyene is selected from polyenes having 5 to 20 carbon atoms and a plurality of vinyl and/or vinylene groups in the molecule, and the content of the groups is 1.5 to 20 pieces per number average molecular weight. (4) The olefin is selected from olefins having 2 to 20 carbon atoms, and the total monomer units of the olefin, aromatic vinyl compound, and aromatic polyene is 100 mass %.

A curable composition includes an olefin-aromatic vinyl compound-aromatic polyene copolymer satisfying conditions (1) to (4) and an additive resin, which is at least one of a hydrocarbon-based elastomer, polyphenylene ether, olefin-aromatic vinyl compound-aromatic polyene copolymerized oligomer, and aromatic polyene-based resin. (1) The number average molecular weight of the copolymer is 5000 to 100000. (2) The aromatic vinyl compound monomer has 8 to 20 carbon atoms, and the content of the unit of the monomer is 0 to 70 mass %. (3) The aromatic polyene is selected from polyenes having 5 to 20 carbon atoms and a plurality of vinyl and/or vinylene groups in the molecule, and the content of the groups is 1.5 to 20 pieces per number average molecular weight. (4) The olefin is selected from olefins having 2 to 20 carbon atoms, and the total monomer units of the olefin, aromatic vinyl compound, and aromatic polyene is 100 mass %.

The present disclosure provides a tire which makes it possible to reduce the increase in hardness and the decrease in wet grip performance from before to after heat aging. The present disclosure relates to a tire including a tread, the tread including an elastomer composition containing a styrene elastomer and urethane particles, the tread satisfying the following relationship (1): (M100a−M100f)/M100f×100≤38 wherein M100f represents the stress at 100% elongation (23° C.) before heat aging, and M100a represents the stress at 100% elongation (23° C.) after heat aging.

The present disclosure provides a tire which makes it possible to reduce the increase in hardness and the decrease in wet grip performance from before to after heat aging. The present disclosure relates to a tire including a tread, the tread including an elastomer composition containing a styrene elastomer and urethane particles, the tread satisfying the following relationship (1): (M100a−M100f)/M100f×100≤38 wherein M100f represents the stress at 100% elongation (23° C.) before heat aging, and M100a represents the stress at 100% elongation (23° C.) after heat aging.

An elastomeric composition is disclosed. The elastomeric composition includes, per 100 parts by weight of rubber (phr): about 5 to about 30 phr of polybutadiene having a cis-1,4 linkage content of at least 95%; about 60 to 100 phr of a styrene/butadiene copolymer; an antioxidant; about 1 to about 20 phr carbon black; about 100-140 phr silica; a silane coupling agent and about 5 to about 40 phr of a polymer selected from the group consisting of ethylene-propylene-diene terpolymer, butyl rubber, poly(isobutylene-co-para-methylstyrene) and poly (isobutylene-co-para-methylstyrene-co-isoprene) terpolymer. The polymer based on ethylene-propylene-diene terpolymer, butyl rubber, poly(isobutylene-co-para-methylstyrene) and poly (isobutylene-co-para-methylstyrene-co-isoprene) terpolymer may be functionalized.