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 &mgr;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 &mgr;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 rubber composition comprising (A) a base rubber, (B) a metal salt of an unsaturated carboxylic acid and/or a mixture of an unsaturated carboxylic acid and zinc oxide, (C) an organic peroxide, and (D) a non-aromatic mercaptan and/or (E) a dialkyl disulfide whose alkyl has 3-10 carbon atoms is suitable for forming center cores of solid golf balls and wound golf balls and one-piece golf balls by a pressure molding process.

Abstract: Disclosed are a rubber compound for a golf ball comprising a base rubber, a metal salt of an &agr;,&bgr;-unsaturated carboxylic acid, an organic peroxide, and synthetic zeolite, wherein the content of the synthetic zeolite is in a range of 0.1 to 15 parts by weight on the basis of 100 parts by weight of the base rubber, and a golf ball including a center core made from the above rubber compound for a golf ball. The rubber compound is usable for a center core of a solid golf ball or a thread wound golf ball, whereby the initial velocity of the center core can be increased and the degree of freedom in design of the golf ball can be enlarged.

Abstract: A rubber composition comprising (A) a base rubber, (B) a metal salt of an unsaturated carboxylic acid and/or a mixture of an unsaturated carboxylic acid and zinc oxide, (C) an organic peroxide, and (D) a non-aromatic mercaptan and/or (E) a dialkyl disulfide whose alkyl has 3-10 carbon atoms is suitable for forming center cores of solid golf balls and wound golf balls and one-piece golf balls by a pressure molding process.

Abstract: Disclosed are a rubber compound for a golf ball comprising a base rubber, a metal salt of an &agr;,&bgr;-unsaturated carboxylic acid, an organic peroxide, and synthetic zeolite, wherein the content of the synthetic zeolite is in a range of 0.1 to 15 parts by weight on the basis of 100 parts by weight of the base rubber, and a golf ball including a center core made from the above rubber compound for a golf ball. The rubber compound is usable for a center core of a solid golf ball or a thread wound golf ball, whereby the initial velocity of the center core can be increased and the degree of freedom in design of the golf ball can be enlarged.

Abstract: There are disclosed a method and an apparatus for removing a cover from a golf ball. There is used a pair of geared rolls in an engaged manner, each geared roll comprising a cylindrical shaft on which teeth are axially formed and are circumferentially arranged at predetermined pitches. After the pair of geared rolls are rotated, the golf ball is placed on the upstream side of rotation of the geared rolls, so that part of the cover of the golf ball is bitten between the geared rolls. The cover bitten between the geared rolls is advanced by a rotational force of the geared rolls and is drawn out to the downstream side of rotation of the geared rolls. In this way, the core and cover of the golf ball are separated from each other. Accordingly, the cover can be mechanically removed from the golf ball with improved efficiency, so that the efficiency of work for recycling golf balls can be improved, and the amount of golf balls disposed as industrial waste can be reduced.

Abstract: A solid type golf ball comprising a central core and an outer cover for the core and having an excellent flight performance and durability and acceptable "click" characteristics is presented. The main component of the outer cover of this golf ball is a polyetherester block copolymer containing the following X, Y and Z units:X: Butylene terephthalate unitY: Ester unit other than butylene terephthalateZ: Polyetherester unit derived from a dicarboxylic acid component containing terephthalic acid and poly(alkylene oxide) glycol having a number average molecular weight of 400 through 3000, wherein the X, Y and Z units are present in the following amounts:30% by weight .ltoreq.X.ltoreq.80% by weight0% by weight .ltoreq.Y.ltoreq.50% by weight20% by weight .ltoreq.Z.ltoreq.70% by weight.

Abstract: Novel abrasion resistant rubber compositions are disclosed. The compositions are prepared by curing the mixtures comprising a diene elastomer, an .alpha.,.beta.-ethylenically unsaturated carboxylic acid, a divalent metal compound, and an organic peroxide. When an unpolymerizable carboxylic acid is added to the mixture, the mechanical properties of the composition are improved. The addition of a carbon black to the mixtures brings about the improvement of weather-proofing property of the composition. The compositions are useful for the rubber stock of solid tires, snow removing plates and the like.

Abstract: One shot mouldable and curable homogeneous rubber composition consisting mainly of polyisoprene rubber and a monomer mixture composed of divinylbenzene and .alpha.-methylstyrene in specifically limited weight ratios of the rubber/the monomer mixture and of divinylbenzene/.alpha.-methylstyrene and containing small amounts of organic peroxide and at least one of amine compound and phenol compound. The cured product of the rubber composition has high Young's modulus, tear energy and tensile strength retention. More improved cured rubbers having these physical properties well balanced in a high level can be easily obtained by additionally adding a small amount of sulfur or p-quinonedioxime to the above rubber composition.

Abstract: An ethylene-propylene copolymer rubber composition having a high Young's modulus, which comprises 100 parts by weight of a mixture of the following ingredients (a) and (b) in a weight ratio of ingredient (a)/ingredient (b) of 67/33-50/50, said ingredient (a) being an ethylene-propylene copolymer having a Mooney viscosity of at least 75, said ingredient (b) being divinylbenzene, (c) 0.3-2.5 parts by weight of an organic peroxide, and (d) 0.01-0.25 part by weight of sulfur, and the homogeneous rubber composition cured at 120.degree.-180.degree.C having a Young's modulus of 200-500 Kg/cm.sup.2, a tensile strength of at least 200 Kg/cm.sup.2, an elongation of at least 300%, a tear energy of at least 10 Kg/cm and retentions of Young's modulus and tensile strength at 70.degree.C of at least 50%.