Abstract: Provided is a natural rubber obtained by drying a gathered natural rubber latex without coagulating, wherein a drum dryer and/or a conveyor type dryer are used for drying.

Abstract: A production process for a viscosity-stabilizer-containing natural rubber comprising a step of adding a viscosity stabilizer liquid diluted with a solvent to a natural rubber, and a viscosity-stabilizer-containing natural rubber latex to which added is a viscosity stabilizer dissolved in an aliphatic chain compound, and a viscosity-stabilizer-containing natural rubber obtained by adding a viscosity stabilizer liquid diluted with a solvent to a natural rubber after it was coagulated.

Abstract: A production process for a viscosity-stabilizer-containing natural rubber comprising a step of adding a viscosity stabilizer liquid diluted with a solvent to a natural rubber, and a viscosity-stabilizer-containing natural rubber latex to which added is a viscosity stabilizer dissolved in an aliphatic chain compound, and a viscosity-stabilizer-containing natural rubber obtained by adding a viscosity stabilizer liquid diluted with a solvent to a natural rubber after it was coagulated.

Abstract: The high aromatic oil provided in the present invention is characterized by that a glass transition point is -45 to -20.degree. C. and an aromatic component measured by Clay-Gel method accounts for 55 to 90% by weight and that a polycyclic aromatic compound measured by IP 346 method accounts for less than 3% by weight based on the whole components of hydrocarbons contained in the oil.This high aromatic oil can suitably be used for various rubber compositions such as tires, rubber vibration insulators and fenders, oil extended synthetic rubbers, printing inks and writing inks.

Abstract: A rubber composition is a mixture of 100 parts by weight of at least one rubber component selected from the group consisting of a natural rubber and a synthetic rubber and 1 to 120 parts by weight of a softening agent containing 0.1 to 4% by weight of asphaltene. The rubber composition simultaneously has a high high-loss property, a high fracture property and a good workability.

Abstract: A rubber composition for a tire tread which is provided by the present invention can be obtained by blending 100 parts by weight of a natural rubber and/or a diene synthetic rubber with40 to 100 parts by weight of a carbon black having characteristic values of a cetyltriammonium bromide adsorption specific surface area (CTAB) being 90 to 220 m.sup.2 /g and a 24M4DBP absorption value being 90 to 140 ml/100 g, and0.1 to 20 parts by weight of an organic unsaturated fatty acid having two or more carbon double bonds in its molecule which includes 10% by weight or more of a conjugated diene acid having at least one pair of two carbon double bonds in a conjugated relation in its molecule.This rubber composition for a tire tread can be suitably used for a pneumatic tire, particularly a pneumatic tire for heavy load having an excellent wear resistance.

Abstract: In a flame-retardant rubber tire comprising an outer rubber body portion consisting essentially of a tread rubber layer, a sidewall rubber layer extending inward from each side edge of the tread rubber layer toward the vicinity of a bead portion in radial direction and a rubber chafer layer arranged in the vicinity of the bead portion, a flame-retardant rubber composition having an oxygen index of not less than 19.8 but not more than 27.5 is disposed so as to amount at least 20% by weight of the tread rubber layer. Such rubber tires are used in electric vehicles, automobiles, airplanes and the like and have excellent self-extinguishing property and flame-delaying property without damaging other rubber properties.

Abstract: A continuous process is described for preparing copolymer compositions of 1,3-conjugated dienes and aromatic vinyl compounds having a weight average molecular weight of greater than about 100,000, and in one embodiment above about 900,000. The process comprises:(A) continuously introducing into a reactor, a 1,3-conjugated diene, an aromatic vinyl compound, a hydrocarbon solvent and a polymerization catalyst comprising a trimetalated 1-alkyne wherein the catalyst is obtained by reacting at a temperature of above about 70.degree. C., a 1-alkyne containing at least 4 carbon atoms, an organo metallic compound, R.degree. M and a 1,3-conjugated diene wherein the alkyne is characterized by the formulaRCH.sub.2 C.tbd.CH (II)wherein R is an alkyl group, R.degree. is a hydrocarbyl group, M is an alkali metal, the mole ratio of R.degree.

Abstract: In a flame-retardant rubber tire comprising an outer rubber body portion consisting essentially of a tread rubber layer, a sidewall rubber layer extending inward from each side edge of the tread rubber layer toward the vicinity of a bead portion in radial direction and a rubber chafer layer arranged in the vicinity of the bead portion, a flame-retardant rubber composition having an oxygen index of not less than 19.8 but not more than 27.5 is disposed so as to amount at least 20% by weight of the tread rubber layer. Such rubber tires are used in electric vehicles, automobiles, airplanes and the like and have excellent self-extinguishing property and flame-delaying property without damaging other rubber properties.

Abstract: A flame-retardant rubber composition has an oxygen index of 19.8-27.5 and comprises not more than 24% by weight of red phosphorus as a flame retardant based on the rubber composition and a nitrile group-containing elastomer as a flame-retardant polymer component as a part of rubber ingredients constituting the rubber composition. Such flame-retardant rubber compositions are very useful in applications such as industrial goods, tire and the like strongly requiring the fire preventing function.

Abstract: Elastomer compositions comprising (A) ultra high molecular weight copolymer compositions of 1,3-conjugated dienes and aromatic vinyl compounds having a weight average molecular weight of greater than about 1,000,000 and (B) oil are described. The ultra high molecular weight copolymer compositions which are also characterized as having an intrinsic viscosity in tetrahydrofuran of at least about 4.0 may be obtained by a process which comprises polymerizing a 1,3-conjugated diene and a vinyl aromatic compound in a hydrocarbon solvent in the presence of a trimetalated 1-alkyne catalyst which comprises the reaction product of a 1-alkyne containing at least 4 carbon atoms, an organo metallic compound R.degree.M and a 1,3-conjugated diene wherein R.degree. is a hydrocarbyl group, M is an alkali metal, the mole ratio of R.degree.M to 1-alkyne is about 3:1 and the mole ratio of conjugated diene to 1-alkyne is from about 2:1 to about 30:1.

Abstract: High-performance tires comprising treads made of elastomer compositions comprising (A) ultra high molecular weight copolymer compositions of 1,3-conjugated dienes and aromatic vinyl compounds having a weight average molecular weight of greater than about 1,000,000; (B) extender oil; and (C) carbon black are described. The ultra high molecular weight copolymer compositions which are also characterized as having an intrinsic viscosity in tetrahydrofuran of at least about 4.0 may be obtained by a process which comprises polymerizing a 1,3-conjugated diene and a vinyl aromatic compound in a hydrocarbon solvent in the presence of a trimetalated 1-alkyne catalyst which comprises the reaction product of a 1-alkyne containing at least 4 carbon atoms, an organo metallic compound R.sup.o M and a 1,3-conjugated diene wherein R.sup.o is a hydrocarbyl group, M is an alkali metal, the mole ratio of R.sup.o M to 1-alkyne is about 3:1 and the mole ratio of conjugated diene to 1-alkyne is from about 2:1 to about 30:1.

Abstract: Elastomer compositions comprising (A) ultra high molecular weight copolymer compositions of 1,3-conjugated dienes and aromatic vinyl compounds having a weight average molecular weight of greater than about 1,000,000 and (B) oil are described. The ultra high molecular weight copolymer compositions which are also characterized as having an intrinsic viscosity in tetrahydrofuran of at least about 4.0 may be obtained by a process which comprises polymerizing a 1,3-conjugated diene and a vinyl aromatic compound in a hydrocarbon solvent in the presence of a trimetalated 1-alkyne catalyst which comprises the reaction product of a 1-alkyne containing at least 4 carbon atoms, an organo metallic compound R.sup.o M and a 1,3-conjugated diene wherein R.sup.o is a hydrocarby group, M is an alkali metal, the mole ratio of R.sup.o M to 1-alkyne is about 3:1 and th mole ratio of conjugated diene to 1-alkyne is from about 2:1 to about 30:1.

Abstract: A continuous process is described for preparing copolymer compositions of 1,3-conjugated dienes and aromatic vinyl compounds having a weight average molecular weight of greater than about 100,000, and in one embodiment above about 900,000. The process comprises:(A) continuously introducing into a reactor, a 1,3-conjugated diene, an aromatic vinyl compound, a hydrocarbon solvent and a polymerization catalyst comprising a trimetalated 1-alkyne wherein the catalyst is obtained by reacting at a temperature of above about 70.degree. C., a 1-alkyne containing at least 4 carbon atoms, an organo metallic compound, R.degree.M and a 1,3-conjugated diene wherein the alkyne is characterized by the formulaRCH.sub.2 C.tbd.CH (II)wherein R is an alkyl group, R.degree. is a hydrocarbyl group, M is an alkali metal, the mole ratio of R.degree.

Abstract: A reinforcing agent for vulcanizable rubber compounds comprises an anhydrous metal salt of an .alpha.,.beta.-ethylenically unsaturated carboxylic acid having a crystalline structure consisting essentially of plates and fibers. Vulcanizable rubber compounds containing such reinforcing agents have improved physical properties over rubber compounds containing conventional metal carboxylic acid salts. Methods for the preparation of such anhydrous metal salts and methods for the reinforcement of vulcanizable rubber compounds therewith are also provided.

Abstract: An ultra high molecular weight copolymer compositions of 1,3-conjugated dienes and aromatic vinyl compounds having a weight average molecular weight of greater than about 1,000,000 are described. The ultra high molecular weight copolymer compositions which are also characterized as having an intrinsic viscosity in tetrahydrofuran of at least about 4.0 may be obtained by a process which comprises polymerizing a 1,3-conjugated diene and a vinyl aromatic compound in a hydrocarbon solvent in the presence of a trimetalated 1-alkyne catalyst which comprises the reaction product of a 1-alkyne containing at least 4 carbon atoms, an organo metallic compound R.degree.M and 1,3-conjugated diene wherein R.degree. is a hydrocarbyl group, M is an alkali metal, the mole ratio of R.degree.M to 1-alkyne is about 3:1 and the mole ratio of conjugated diene to 1-alkyne is from about 2:1 to about 30:1.

Abstract: Solid golf balls comprise a vulcanizable rubber and a reinforcing filler comprising an essentially anhydrous metal salt of an .alpha.,.beta.-ethylenically unsaturated carboxylic acid. Golf balls containing such reinforcing fillers have improved physical properties over rubber compounds containing conventional metal carboxylic acid salts. Additionally, the rubber compounds have improved processability and shorter curing time.

Abstract: A reinforcing agent for vulcanizable rubber compounds comprises an anhydrous metal salt of an .alpha.,.beta.-ethylenically unsaturated carboxylic acid having a crystalline structure consisting essentially of plates and fibers. Vulcanizable rubber compounds containing such reinforcing agents have improved physical properties over rubber compounds containing conventional metal carboxylic acid salts. Methods for the preparation of such anhydrous metal salts and methods for the reinforcement of vulcanizable rubber compounds therewith are also provided.

Abstract: A reinforcing agent for vulcanizable rubber compounds comprises an anhydrous metal salt of an .alpha.-.beta.-ethylenically unsaturated carboxylic acid having a crystalline structure consisting essentially of plates and fibers. Vulcanizable rubber compounds containing such reinforcing agents have improved physical properties over rubber compounds containing conventional metal carboxylic acid salts. Methods for the preparation of such anhydrous metal salts and methods for the reinforcement of vulcanizable rubber compounds therewith are also provided.

Abstract: A method for incorporating metal salts of .alpha.,.beta.-ethylenically unsaturated carboxylic acids into polymers and improving the cured physical properties of vulcanizable rubber compositions based on such polymers. The method includes the steps of preparing a polymer cement in a suitable organic solvent, forming a suspension of the metal salt of an .alpha.,.beta.-ethylenically unsaturated carboxylic acid in a suitable aliphatic hydrocarbon solvent miscible with the organic solvent, mixing the polymer cement and the suspension together and thereafter removing the solvents to provide the metal salt uniformly dispersed within the polymer.