Abstract: A zinc acrylate particle composition which is substantially fine and, even when kneaded with a rubber composition, is capable of being uniformly dispersed and kneaded in a state very rarely inducing fast adhesion or agglomeration, a method for the production thereof, and a golf ball using the composition are provided. The zinc acrylate particle composition contemplated by this invention comprises zinc acrylate satisfying the conditions that the proportion accounted for by the zinc acrylate particles measuring not less than 300 ?m in particle size as determined by the dry type method be not more than 20% by mass of all the particles, that the median of particle sizes as determined by the dry type method be in the range of 10-300 ?m, and that the ratio of the median (A) of particle sizes as determined by the dry type method to the median (B) of particle sizes as determined by the wet type method exceed 2, and an anionic surfactant.

Abstract: A golf ball is characterized by comprising a molded and vulcanized product of a rubber composition as a constituent component, the rubber composition comprising 100 pbw of a base rubber composed primarily of a polybutadiene containing at least 60 wt % of cis-1,4-bond, having a Mooney viscosity (ML1+4, 100° C.) of at least 30, and synthesized using a rare-earth catalyst, 15-50 pbw of an unsaturated carboxylic acid and/or a metal salt thereof, at least 2 pbw of a processing aid having a highest melting point of up to 115° C., and at least two organic peroxides including an organic peroxide having the shortest half-life at 155° C. designated (a) and another organic peroxide having the longest half-life at 155° C. designated (b), a ratio of half-lives (bt/at) being at least 7 wherein at is the half-life of (a) and bt is the half-life of (b), a total content of the organic peroxides being 0.1-0.9 pbw per 100 pbw of the base rubber.

Abstract: A rubber composition for a one-piece golf ball or the solid core of a multilayer structure solid golf ball having a solid core enclosed with a cover directly or via an intermediate layer is provided comprising a base rubber, a dry preblend of an unsaturated carboxylic acid metal salt with a solid rubber having a Mooney viscosity (ML1+4, 100° C.) of 5-150, and an organic peroxide.

Abstract: A rubber compound for solid golf balls which includes (A) a base rubber, (B) a filler, (C) an organic peroxide, and (D) a co-crosslinking agent coated with a coating rubber in which the ratio of the co-crosslinking agent to the coating rubber is from 100/1 to 100/20 by weight. A solid golf ball with good flight performance and uniform quality which is formed from the rubber compound. The rubber compound contains a co-crosslinking agent (a metal salt of unsaturated carboxylic acid) finely dispersed therein and also permits processing with good workability.

Abstract: Disclosed herein is a one-piece golf ball formed by vulcanization from a rubber composition composed of 100 parts by weight of rubber base material, 10 to 40 parts by weight of unsaturated carboxylic acid, 10 to 60 parts by weight of metal oxide, and 0.9 to 5 parts by weight of organic peroxide, said rubber base material containing 60 to 100% by weight based on the weight of a polybutadiene which is synthesized with a catalyst of rare earth element, contains no less than 60% of cis-1,4-linkage, and has a Mooney viscosity (ML1+4(100° C.)) no less than 40. This golf ball has good shot feeling and high rebound resilience and is easy to produce by extrusion.

Abstract: A golf ball, typically its core, is manufactured by hot molding a rubber composition comprising a base rubber, an unsaturated carboxylic acid or a metal salt thereof, and an organic peroxide, the base rubber comprising a methacryloxy or acryloxy-modified silicone polymer and optionally, a peroxide-crosslinkable rubber. The golf ball exhibits high rebound and prevents the rebound property from declining at low temperatures.

Abstract: A golf ball, typically its core, is manufactured by molding and vulcanizing a rubber composition comprising a base rubber, an unsaturated carboxylic acid or a metal salt thereof, an inorganic filler, an organic peroxide, and an organosulfur compound. The base rubber contains a polybutadiene having a Mw of 60-150×104 and a Mw/Mn of up to 2.0 and containing at least 98% of cis-1,4 bonds and up to 1.5% of trans-1,4 bonds. The composition is easy to mold and work, and the golf ball has good rebound and improved flight performance.

Abstract: A golf ball has a core obtained by molding and vulcanizing a rubber composition comprising (A) a base rubber which includes a polybutadiene having a cis-1,4 content of at least 60 wt %, (B) an unsaturated carboxylic acid and/or metal salt thereof, (C) an inorganic filler and (D) at least one organic peroxide selected from among 1,1-bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, and 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane. The golf ball has excellent rebound characteristics and flight performance as well as a high productivity due to a reduced vulcanization time.

Abstract: A golf ball includes, as a composing element, a hot-molded product of a rubber composition. The rubber composition contains a polybutadiene having 60 wt % or more of cis-1,4-bonds and 40 or more of a Mooney viscosity (ML1+4(100° C.)), unsaturated carboxylic acid and/or a metal salt thereof, an organic peroxide, and a monophenol based antioxidant. The golf ball can be produced with good workability because of no burn at the time of kneading the rubber composition, while preventing a reduction in rebound characteristic.

Abstract: Disclosed is a rubber composition for forming a core of a solid golf ball, the composition containing a base rubber (A); a filler (B); an organic peroxide (C); and a dry blend and/or a solvent slurry blend (D) of an unsaturated carboxylic acid metallic salt and a metal-containing organic sulfur compound represented by the following formula (1): (wherein X represents a halogen atom, each of m and n represents an integer of 0 to 5 inclusive, and M represents a divalent metallic atom). The rubber composition exhibits high curing rate, and can be cured within shorter time, whereby productivity of a core can be improved.

Abstract: Disclosed herein is a one-piece golf ball formed by vulcanization from a rubber composition composed of 100 parts by weight of rubber base material, 10 to 40 parts by weight of unsaturated carboxylic acid, 10 to 60 parts by weight of metal oxide, and 0.9 to 5 parts by weight of organic peroxide, said rubber base material containing 60 to 100% by weight based on the weight of a polybutadiene which is synthesized with a catalyst of rare earth element, contains no less than 60% of cis-1,4-linkage, and has a Mooney viscosity (ML1+4(100° C.)) no less than 40. This golf ball has good shot feeling and high rebound resilience and is easy to produce by extrusion.

Abstract: A rubber composition for a solid golf ball contains a polybutadiene rubber component, a co-crosslinking agent, an organic peroxide, a filler, and an organic sulfur compound. When a core for a solid golf ball is formed by using the rubber composition for a solid golf ball, the content of a trans-structure in a cross-linked polybutadiene rubber component on the surface of the core is in a range of 20 to 39%, and a value obtained by subtracting the content of the trans-structure in the cross-linked polybutadiene rubber component at the center of the core from the content of the trans-structure in the cross-linked polybutadiene rubber component on the surface of the core is in a range of 5 to 35%. A solid golf ball produced by using such a core is excellent in hit feeling and flight characteristics. A method of producing a core for a solid golf ball makes it possible to simply produce the core specified as described above.

Abstract: A golf ball is characterized by comprising a molded and vulcanized product of a rubber composition as a constituent component, the rubber composition comprising 100 pbw of a base rubber including 60-100 wt % of a polybutadiene containing art least 60 wt % of cis-1,4-bond, having a Mooney viscosity (ML1+4 (100° C.)) of at least 40, and synthesized using a rare-earth catalyst, 10-60 pbw of an unsaturated carboxylic acid and/or a metal salt thereof, 0.1-5 pbw of an organosulfur compound, 5-80 pbw of an inorganic filler, and at least two organic peroxides including an organic peroxide having the shortest half-life at 155° C. designated (a) and another organic peroxide having the longest half-life at 155° C. designated (b), a ratio of half-lives (bt/at) being from 7 to 20 wherein at is the half-life of (a) and bt is the half-life of (b), a total content of the organic peroxides being 0.1-0.8 pbw per 100 pbw of the base rubber.

Abstract: A golf ball includes, as a composing element, a hot-molded product of a rubber composition. The rubber composition contains a polybutadiene having 60 wt % or more of cis-1,4-bonds and 40 or more of a Mooney viscosity (ML1+4(100° C.)), unsaturated carboxylic acid and/or a metal salt thereof, an organic peroxide, and a monophenol based antioxidant. The golf ball can be produced with good workability because of no burn at the time of kneading the rubber composition, while preventing a reduction in rebound characteristic.

Abstract: A golf ball is manufactured by molding and vulcanizing a rubber composition comprising 100 pbw of a base rubber composed primarily of a polybutadiene having a cis-1,4 content of at least 60 wt % and a Mooney viscosity of at least 30 and synthesized using a rare-earth catalyst, 15-50 pbw of an unsaturated carboxylic acid and/or a metal salt thereof, at least 2 pbw of a processing aid having a highest melting point of up to 115° C., and 1-5 pbw of an organic peroxide. The golf ball can be efficiently manufactured and has excellent rebound characteristics.

Abstract: A golf ball is characterized by comprising a molded and vulcanized product of a rubber composition as a constituent component, the rubber composition comprising 100 pbw of a base rubber composed primarily of a polybutadiene containing at least 60 wt % of cis-1,4-bond, having a Mooney viscosity (ML1+4, 100° C.) of at least 30, and synthesized using a rare-earth catalyst, 15-50 pbw of an unsaturated carboxylic acid and/or a metal salt thereof, at least 2 pbw of a processing aid having a highest melting point of up to 115° C., and at least two organic peroxides including an organic peroxide having the shortest half-life at 155° C. designated (a) and another organic peroxide having the longest half-life at 155° C. designated (b), a ratio of half-lives (bt/at) being at least 7 wherein at is the half-life of (a) and bt is the half-life of (b), a total content of the organic peroxides being 0.1-0.9 pbw per 100 pbw of the base rubber.

Abstract: A golf ball is characterized by comprising a molded and vulcanized product of a rubber composition as a constituent component, the rubber composition comprising 100 pbw of a base rubber including 60-100 wt % of a polybutadiene containing at least 60 wt % of cis-1,4-bond, having a Mooney viscosity (ML1+4 (100° C.)) of at least 40, and synthesized using a rare-earth catalyst, 10-60 pbw of an unsaturated carboxylic acid and/or a metal salt thereof, 0.1-5 pbw of an organosulfur compound, 5-80 pbw of an inorganic filler, and at least two organic peroxides including an organic peroxide having the shortest half-life at 155° C. designated (a) and another organic peroxide having the longest half-life at 155° C. designated (b), a ratio of half-lives (bt/at) being from 7 to 20 wherein at is the half-life of (a) and bt is the half-life of (b), a total content of the organic peroxides being 0.1-0.8 pbw per 100 pbw of the base rubber.

Abstract: A rubber composition for a one-piece golf ball or the solid core of a multilayer structure solid golf ball having a solid core enclosed with a cover directly or via an intermediate layer is provided comprising a base rubber, a dry preblend of an unsaturated carboxylic acid metal salt with a solid rubber having a Mooney viscosity (ML1+4, 100° C.) of 5-150, and an organic peroxide.

Abstract: A rubber composition for a one-piece golf ball or the solid core of a multilayer structure solid golf ball having a solid core enclosed with a cover directly or via an intermediate layer is provided comprising a base rubber, a dry preblend of an unsaturated carboxylic acid metal salt with a solid rubber having a Mooney viscosity (ML1+4, 100° C.) of 5-150, and an organic peroxide.

Abstract: Disclosed is a rubber composition for forming a core of a solid golf ball, the composition containing a base rubber (A); a filler (B); an organic peroxide (C); and a dry blend and/or a solvent slurry blend (D) of an unsaturated carboxylic acid metallic salt and a metal-containing organic sulfur compound represented by the following formula (1): 1