Abstract:
Rubber compositions having improved tensile strength, elongation and modulus of unvulcanized rubbers without deteriorating physical properties of vulcanized rubbers are prepared by utilizing synergistic effect of addition of a filler having high reinforcing property and alkadiene sulfones in given amounts to natural rubber and/or dienic synthetic rubbers.
Abstract:
A rubber composition having an improved crack growth resistance is disclosed, which contains 1-40 wt % of granular bodies having an average particle diameter of 5-500 .mu.m, which contain 2-40 wt % of micro short fibers having an average diameter of not more than 1 .mu.m, an average length of 1-30 .mu.m and an aspect ratio of not less than 8 and orientated in uniaxial or biaxial direction, and is random in the orientation axis of the micro short fiber between the granular bodies.
Abstract:
A pneumatic radial tire comprising: (1) a cylindrical tread portion; (2) side portions located at both sides of the tread portion and extending inwardly in the radial direction; (3) bead portions located at the inner edge portions of the side portions; (4) a carcass comprising at least one ply which is reinforced with a belt arranged on the inside of the tread portion, wherein said belt and/or said carcass ply is reinforced by steel cords; and (5) a rubber composition surrounding the steel cords, wherein said rubber composition comprises: (a) 100 parts by weight of at least one rubber selected from the group consisting of natural rubber and dienic synthetic rubber; (b) 0.1-5.0 parts by weight of alkadiene sulfone; and (c) 0.05-1.0 parts by metal weight of at least one metal salt of an organic acid selected from the group consisting of cobalt salt of an organic acid and nickel salt of an organic acid.
Abstract:
Disclosed herein is a rubber composition for use in vibration insulating material, which comprises as rubber components 5-50 parts by weight of a copolymer consisting of 99.5-45% by weight of a conjugated diolefin, 0.5-30% by weight of an ethylenically unsaturated carboxylic acid and 0-40% by weight of another vinly monomer polymerizable therewith, and 50-95 parts by weight of at least one rubber selected from natural rubber and synthetic diene rubbers. This rubber composition is excellent in the breaking properties and vibration insulating properties with a small temperature dependence of hysteresis loss.
Abstract:
A rubber composition having improved cut growth resistance, processability and dimensional stability is disclosed, which comprises not less than 20 parts by weight of polyisoprene having a melting point of not less than 10.degree. C. and a content of cis-1,4 bond of not less than 88% and the balance of at least one diene rubber.
Abstract:
A rubber composition having excellent fracture properties and cut growth resistance is disclosed, which consists of 10-95 parts by weight of polybutadiene having a content of cis-1,4 bond of at least 70% and an average chain length of 1,4-sequence of 110-450 and 90-5 parts by weight of at least one diene rubber.
Abstract:
Organic micro-fiber reinforced rubber compositions having high elastic modulus, excellent crack growth resistance, impact cut resistance and rebound resilience and a small swell value are prepared by incorporating 10-100 parts by weight of carbon black, 3-30 parts by weight of organic micro-fibers based on 100 parts by weight of at least one rubber selected from a group consisting of natural rubber, synthetic polyisoprene rubber, butyl rubber, halogenated butyl rubber, polybutadiene rubber, styrene-butadiene copolymeric rubber, ethylene-propylene-diene ternary copolymeric rubber and acrylonitrile-butadiene copolymeric rubber, said micro-organic staple fibers being lower than 30.degree. C. or higher than 120.degree. C. in glass transition temperature of amorphous portion and higher than 160.degree. C. in melting point of crystal portion, and having an average length of the micro-fibers of 0.8-30 .mu.m, an average diameter of the micro-fibers of 0.02-0.8 .mu.m and a ratio of the average length of the micro-fibers to the average diameter of the micro-fibers of 8-400.
Abstract:
A polybutadiene rubber composition having an improved green strength is disclosed, which comprises a polybutadiene having a content of cis-1,4 bond of at least 70%, an average chain length of 1,4-bond of 110.about.450 and a molecular weight distribution represented by a ratio of weight-average molecular weight to number-average molecular weight of not less than 5.0.
Abstract:
A rubber composition having improved wet skid resistance and rolling resistance is disclosed, which comprises (A) 10-90% by weight of polybutadiene rubber having a content of cis-1,4-bond at least 80% and an average chain length of cis-1,4-bond of not less than 110, and (B) 10-90% by weight of random styrene-butadiene copolymer rubber obtained by copolymerization in the presence of an organic metal catalyst and having a content of bound styrene of not more than 40% by weight and a content of 1,2-bond in total butadiene unit of 30-95%.
Abstract:
A pneumatic radial tire having sidewalls, the rubber composition of said sidewalls comprising, based on 100 parts by weight of rubber, 20 to 90 parts by weight of butadienepiperylene copolymer and 80 to 10 parts by weight of at least one rubbery diene polymer selected from the group consisting of natural rubber, synthetic polyisoprene rubber, polybutadiene rubber, butadiene-styrene copolymer rubber, ethylenepropylene-diene ternary copolymer rubber and acrylonitrile-butadiene copolymer rubber.