摘要:
High vinyl polybutadiene or styrene-butadiene copolymer obtained by polymerizing 1,3-butadiene alone or with styrene in a hydrocarbon solvent using an organolithium compound as an initiator and coupling the resulting polymer, characterized in that(1) the polybutadiene or styrene-butadiene copolymer comprises at least 20% by weight of a polymer having in its molecular chain a linkage between butadienyl and at least one metal selected from the group consisting of silicon, germanium, tin and lead,(2) the styrene content of said copolymer is 40% by weight or less, and(3) the polybutadiene or the butadiene portion of the styrene-butadiene copolymer has a vinyl content of 50 to 95%.Said polybutadiene or styrene-butadiene copolymer has low rolling resistance, high wet skid resistance, highly improved fracture property and, an excellent processability.
摘要:
Styrene-butadiene random copolymers having an average vinyl content of at least 70%, a breadth of the distribution of vinyl contents of at least 20%, a Mooney viscosity (ML.sub.1+4, 100.degree. C.) of 10 to 150, and a styrene content of about 3 to 30% by weight. They are prepared by copolymerizing styrene and butadiene in a hydrocarbon solvent in the presence of an organolithium initiator and a Lewis base and, if necessary, an anionic surface active agent containing --SO.sub.3 M or --OSO.sub.3 M (wherein M is Na, K, Rb or Cs) under temperature-raising conditions. They are rubber materials having low rolling resistance and high wet skid resistance.
摘要:
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.
摘要:
A styrene-butadiene block copolymer having a Mooney viscosity (ML.sub.1+4, 100.degree. C.) of 10 to 150 comprising two specific random styrene-butadiene copolymer blocks different in bound styrene content and in vinyl content in the butadiene portion, and optionally polybutadiene blocks, wherein the total vinyl content in the whole bound butadiene is 30 to 70% and the total bound styrene content is 10 to 40% by weight. Said block copolymer is excellent in wet skid resistance and rolling resistance, well-balanced in fracture and wear characteristics and also satisfactory in processability and cold flow property.
摘要:
An electroluminescent cell which exhibits a high luminous efficiency and excellent durability is provided. The electroluminescent material comprises a unit (AB) which is formed by alternate copolymerization of hole transfer monomers and electron transfer monomers, and a unit (A) which is formed by the polymerization of hole transfer monomers, wherein the molar ratio of the total of the structural units originating from the hole transfer monomers and the structural units originating from the electron transfer monomers in the unit (AB) and the structural units originating from the hole transfer monomers in the unit (A) is from 50:50 to 5:95. The electroluminescent cell has an anode layer 2, an electroluminescent material layer 3 made from the electroluminescent material, an electron transfer luminous layer 4, and a cathode layer 5.
摘要:
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.
摘要:
An EL cell exhibiting high luminous efficiency and excellent durability is disclosed. The EL cell comprises a layer of a block copolymer comprising a block component (A) of the following formula (1) having a positive hole transfer capability and a block component (B) of the following formula (2) having an electron transfer capability at molar ratio of the block component (A) to the block (B) between 0.1:99.9 and 99.9:0.1. ##STR1##
摘要:
A rubber composition suitable for use in tire tread is disclosed, which contains at least 20 parts by weight of a block copolymer per 100 parts by weight of total rubber content. This block copolymer comprises (A) a polymer segment obtained by starting from conjugated diolefin and monovinyl aromatic hydrocarbon and having a content of monovinyl aromatic hydrocarbon bond of not more than 10% by weight and (B) a copolymer segment obtained by copolymerization of conjugated diolefin and monovinyl aromatic hydrocarbon and having a content of monovinyl aromatic hydrocarbon bond of 15-50% by weight. Further, the block copolymer satisfies the following conditions:(i) the block copolymer contains at least 10% by weight of each of the segments (A) and (B);(ii) a total content of monovinyl aromatic hydrocarbon bond in the block copolymer is 10-40% by weight;(iii) an average content of vinyl bond in conjugated diolefin portion of the block copolymer is 20-70% by weight; and(iv) the block copolymer includes at least 20% by weight of a polymer having a metal-carbon bond in its molecular chain.
摘要:
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.
摘要:
A process for producing a conjugated diene polymer, characterized by polymerizing at least one conjugated diene with a catalyst consisting of (A) a reaction product of a Lewis base and a carboxylate of a rare earth element of the lanthanum series represented by Ln(R.sup.1 CO.sub.2).sub.3 wherein Ln is a rare earth element of the lanthanum series having an atomic number of 57 to 71 and R.sup.1 is a hydrocarbon substituent having 1 to 20 carbon atoms, (B) an organic aluminum compound represented by AlR.sup.2 R.sup.3 R.sup.4 wherein R.sup.2, R.sup.3 and R.sup.4, which may be identical or different, represent hydrogen atoms or hydrocarbon substituents having 1 to 8 carbon atoms, excluding the case where all of R.sup.2, R.sup.3 and R.sup.4 are hydrogen atoms at the same time, and (C) an (alkyl)aluminum halide represented by AlX.sub.n R.sup.5.sub.3-n wherein X is Cl, Br, F or I; R.sup.5 is a hydrocarbon substituent having 1 to 8 carbon atoms; and n has a value of 1, 1.5, 2 or 3, or consisting of these (A), (B) and (C) components and (D) a conjugated diene. A polymer obtained by said process has a high cis-1,4-configuration content and is excellent in physical properties of vulcanizate.