Abstract: An electrically conductive elastomer film comprising (i) a thermoplastic elastomer and (ii) 5 to 100 parts by weight, based on 100 parts by weight of the thermoplastic elastomer, of an electrically conductive filler, and having a volume resistance of 0.1 to 5 &OHgr;cm as measured in the direction perpendicular to the film plane. This film is produced by a casting process wherein a releasable base is coated with a solution prepared by dissolving or dispersing 5 to 30 parts by weight of the sum of a thermoplastic elastomer and an electrically conductive filler in 100 parts by weight of an organic solvent; the thus-formed coating is dried; and then the thus-formed film is released from the releasable base.

Abstract: A process for preparation of a rubber composition which comprises mixing a modified diene polymer wherein at least one functional group represented by the formula >C.dbd.N.sup.+ < was bound to the main chain of the polymer or the main chain and terminal of the polymer directly or through another atomic group, with carbon black in an organic solvent, and separately the mixture of the modified diene polymer with carbon black from the resultant mixture solution.

Abstract: An abrasion-resistant rubber composition comprises as rubber components (A) 30-95 wt. % of an end-modified butadiene polymer and (B) 70-5 wt. % of a diene rubber other than the end-modified butadiene polymer (A). The end-modified butadiene polymer (A) is obtained by reacting at least one compound to active terminals of a starting butadiene polymer having a trans 1,4 bond content of 70-95 wt. %. The at least one compound is selected from N-substituted aminoketones, N-substituted thioaminoketones, N-substituted amino-aldehydes, N-substituted thioaminoaldehydes and compounds containing in the molecules thereof an atomic group represented by the following formula: ##STR1## in which M stands for an oxygen or sulfur atom.

Abstract: A rubber composition comprises as rubber components (A) 30-95 wt. % of an end-modified styrene-butadiene copolymer and (B) 70-5 wt. % of a diene rubber other than the end-modified styrene-butadiene copolymer (A). The end-modified styrene-butadiene copolymer (A) is obtained by reacting at least one compound to active terminals of a starting styrene-butadiene copolymer containing butadiene moieties, the trans-1,4 bond content of which is 70-95 wt. %, and having a styrene content of 5-60 wt. %. The at least one compound is selected from N-substituted aminoketones, N-substituted thioaminoketones, N-substituted aminoaldehydes, N-substituted thioaminoaldehydes and compounds containing in the molecules thereof an atomic group represented by the following formula: ##STR1## in which M stands for an oxygen or sulfur atom. The diene rubber (B) has a glass transition temperature higher than -60.degree. C.

Abstract: A rubber composition comprising a rubbery polymer, carbon black and a processing aid is described wherein the processing aid is a liquid diene polymer having a weight average molecular weight of about 5,000 to 140,000 and having an atomic group having a bond represented by the formula:>C.dbd.N.sup..crclbar. <,which is bonded to the terminal of the polymer chain, and the amount of the liquid diene polymer is 1 to 100 parts by weight per 100 parts by weight of the rubbery polymer. The liquid diene polymer is usually prepared by reacting an anionic living liquid diene polymer with a compound having in the molecule a bond represented by the formula: ##STR1## in which M represents an oxygen or sulfur atom.

Abstract: A rubber composition comprising, as rubber components, 10-40 % by weight of (1) a styrene-butadiene copolymer rubber obtained by solution polymerization, having a styrene content of less than 20% by weight and a trans-1,4 bond content in butadiene portion, of more than 90% by weight and 60-90% by weight of (2) a diene rubber other than the styrene-butadiene copolymer rubber (1), having a glass transition temperature of -60.degree. C. or below.

Abstract: A rubber composition for tire treads which comprises 100 parts by weight of a rubber component comprising 10 to 100 parts by weight of a styrene-butadiene copolymer rubber produced by a solution polymerization and 90 to 0 parts by weight of at least one of other diene rubbers having a glass transition temperature (Tg) of -60.degree. C. at lowest, and at least 70 parts by weight of a carbon black mixed in the rubber component, the styrene-butadiene copolymer rubber having a styrene content of 45 to 65% by weight, a content of butadiene derived vinyl groups of 20 to 70 parts by weight and a content of a styrene sequence consisting of not less than 8 bonded styrene monomer units of at largest 10% by weight of the above styrene content.

Abstract: A rubber composition capable of giving a vulcanized rubber having improved rebound and elongation at break. The composition consists essentially of(1) 100 parts by weight of a rubber component composed of (a) 10 to 100% by weight of a modified conjugated diene polymer obtained by reacting a conjugated diene polymer having an alkali metal and/or an alkaline earth metal bonded thereto with a compound containing the ##STR1## bond in which M represents an oxygen or sulfur atom in the molecule, said modified conjugated diene polymer consisting essentially of 50 to 100% by weight of at least one C.sub.4 -C.sub.12 conjugated diene monomer and 0 to 50% by weight of an aromatic vinyl monomer, the amount of said compound bonded being at least 0.

Abstract: An improved diene type polymer rubber is prepared by reacting a diene type polymer rubber, to which an alkali metal and/or an alkaline earth metal has been added, with a compound represented by the formula: ##STR1## wherein M is oxygen or sulfur, R.sub.1 and R.sub.4 are a substituent having no hydrogen on the .alpha.-carbon atom, R.sub.2 and R.sub.3 are hydrogen or a hydrocarbon group, m is an integer of at least 2, and n is an integer of 2 to 4. The diene type polymer rubber is characterized in that, even after storage for a long time, the Mooney viscosity rises only to a very slight extent, and the rebound, wet skid resistance and other physical properties of the cured product thereof are not substantially changed.

Abstract: A rubber composition for tire tread, comprising a rubber mixture composed of two kinds of styrene-butadiene copolymer rubber different from each other in the styrene content and the vinyl bond content in butadiene, polybutadiene rubber, natural rubber and/or synthetic polyisoprene rubber.

Abstract: A vibration insulating rubber having an improved balance between its loss tangent and dynamic-to-static modulus ratio is prepared by molding and curing a rubber compound comprising as a rubber component a modified rubbery polymer obtained by reacting (1) a rubbery polymer having at least one metal selected from alkali metals and alkaline earth metals bonded to its molecular chain with (2) at least one compound selected from organic compounds having a bond of the formula ##STR1## wherein X represents an oxygen or sulfur atom, in the molecule, benzophenones having at least one of unsubstituted and substituted amino groups, and thiobenzophenones having at least one of unsubstituted or substituted amino groups.

Abstract: A rubber composition for a tire tread comprising a novel modified styrene-butadiene copolymer rubber, carbon black, and aromatic oil.

Abstract: A process for modifying a polymer of a conjugated diene, which comprises reacting a polymer of a conjugated diene containing at least one metal selected from alkali metals and alkaline earth metals with a compound having a linkage of the following formula ##STR1## wherein X represents an oxygen or sulfur atom, in the molecule.

Abstract: A process for making a diene polymer rubber which comprises reacting an active diene polymer rubber having alkali metal and/or alkaline earth metal terminals, which is obtained by polymerizing a conjugated diene monomer alone or together with an aromatic vinyl monomer in a hydrocarbon solvent, using an alkali metal and/or alkaline earth metal initiator, with(1) a tin compound expressed by the general formula R.sub.a S.sub.n X.sub.b (in which R stands for an alkyl, alkenyl, cycloalkenyl or aromatic hydrocarbon group; X is a halogen atom; a is an integer of 0-2, and b is an integer of 2-4), and(2) at least one organic compound selected from the group consisting of aminoaldehydes, aminoketones, aminothioaldehydes, aminothioketones and the organic compounds having in their molecules ##STR1## (in which A stands for an oxygen or sulfur atom).

Abstract: A process for making a diene copolymer rubber having improved rebound, which comprises polymerizing a conjugated diene monomer with an aromatic vinyl monomer in a hydrocarbon solvent in the presence of an alkali metal and/or alkaline earth metal initiator, to form a dienyl-metal terminated, conjugated diene-aromatic vinyl copolymer rubber, and thereafter reacting the copolymer rubber with at least one reactant selected from the group consisting of aminoaldehydes, aminoketones, aminothioaldehydes and aminothioketones.

Abstract: A rubber composition for tire treads, comprising [I] 10 to 90% by weight of a styrene-butadiene copolymer rubber containing not more than 40% by weight of bound styrene and having bonded to a carbon atom of the rubber molecular chain at least 0.1 mole, per mole of the rubber molecular chain, of an atomic grouping represented by the following formula ##STR1## wherein: X represents O or S,R.sub.1 and R.sub.2 are identical or different and each represents an amino group or an alkyl-substituted amino group,R.sub.3 and R.sub.4 are identical or different and each represents a substituent other than the above-mentioned,m, p and q each represent O or an integer of at least 1,n represents an integer of at least 1, m+p=0-5, and n+q=1-5,and [II] 90 to 10% by weight of at least one rubber selected from the group consisting of styrene-butadiene copolymer rubber having a bound styrene content of not more than 40% by weight and polyisoprene rubber.

Abstract: A rubber composition for tire treads, comprising [I] 10 to 70% by weight of a polybutadiene rubber having bonded to a carbon atom of the rubber molecular chain at least 0.1 mole, per mole of the rubber molecular chain, of an atomic grouping represented by the following formula ##STR1## wherein X represents O or S, R.sub.1 and R.sub.2 are identical or different and each represents an amino group or an alkyl-substituted amino group, R.sub.3 and R.sub.4 are identical or different and each represents a substituent other than the above-mentioned, m, p and q each represent O or an integer of at least 1, n represents an integer of at least 1, m+p=0-5, and n+q=1-5,and [II] 90 to 30% by weight of at least one rubber selected from the group consisting of styrene-butadiene copolymer rubber having a bound stryene content of not more than 50% by weight and polyisoprene rubber.

Abstract: A rubber composition comprising at least 10% by weight, based on the entire rubber component, of a highly unsaturated polymer rubber having a benzophenone introduced into its molecular chains in an amount of at least 0.1 mole per mole of the rubber molecular chains.

Abstract: A rubber composition comprising as main components (1) at least one rubber having a glass transition temperature of from -45.degree. C. to 0.degree. C. and selected from the group consisting of an isoprene-butadiene copolymer rubber and polyisoprene rubber and (2) at least one rubber selected from the group consisting of natural rubber and cis-1,4-polyisoprene rubber having a cis-1,4-linkage content of at least 90 mole %, said composition having a value, defined by the following formula, of at least 10,[(R-53)+(S-100)]wherein R is a rebound (%) measured at 51.degree. C. by a Dunlop Tripso meter for a vulcanized product of said rubber composition, and S, as defined in the specification, is a wet skid resistance index on a road surface defined by ASTM E-303-74 which is determined at 19.degree. C. by a portable skid tester for a vulcanized product of said rubber composition.

Abstract: A process for preparing a tire tread rubber composition having improved rolling resistance and wet skid resistance comprising [I] 100 parts by weight of a rubber material composed of 25 to 75% by weight of substantially amorphous polybutadiene having a 1,2-bond unit content of 65 to 90 mole % and a Mooney viscosity (ML.sub.1+4, 100.degree. C.) of 20 to 100 and 75 to 25% by weight of natural rubber and/or cis-1,4-polyisoprene, and [II] 40 to 70 parts by weight of carbon black, said process comprising (1) mechanically compounding 40 to 60 parts by weight of the rubber material [I] with 40 to 70 parts by weight of carbon black [II], and then (2) adding to the resulting mixture the rubber material [I] in an amount sufficient to adjust the amount of the carbon black [II] to 40 to 70 parts by weight per 100 parts by weight of the rubber material [I] and mechanically compounding them.