Abstract: In general the present invention provides a functionalized polymer prepared by a process comprising the steps of preparing a pseudo-living polymer by polymerizing conjugated monomer with a lanthanide-based catalyst, and reacting the pseudo-living polymer with a functionalizing agent defined by the formula (I) A-R1—Z?? (I) where R1 is a divalent bond or divalent organic group comprising from 0 to about 20 carbon atoms, A is a substituent that will undergo an addition reaction with a pseudo-living polymer, and Z is a substituent that will react or interact with silica or carbon black reinforcing fillers, with the proviso that A, R1, and Z are substituents that will not protonate a pseudo-living polymer.

Abstract: In general the present invention provides a functionalized polymer prepared by a process comprising the steps of preparing a pseudo-living polymer by polymerizing conjugated monomer with a lanthanide-based catalyst, and reacting the pseudo-living polymer with a functionalizing agent defined by the formula (I) A-R1—Z??(I) where R1 is a divalent bond or divalent organic group comprising from 0 to about 20 carbon atoms, A is a substituent that will undergo an addition reaction with a pseudo-living polymer, and Z is a substituent that will react or interact with silica or carbon black reinforcing fillers, with the proviso that A, R1, and Z are substituents that will not protonate a pseudo-living polymer.

Abstract: In general the present invention provides a functionalized polymer prepared by a process comprising the steps of preparing a pseudo-living polymer by polymerizing conjugated monomer with a lanthanide-based catalyst, and reacting the pseudo-living polymer with a functionalizing agent defined by the formula (I) A-R1—Z??(I) where R1 is a divalent bond or divalent organic group comprising from 0 to about 20 carbon atoms, A is a substituent that will undergo an addition reaction with a pseudo-living polymer, and Z is a substituent that will react or interact with silica or carbon black reinforcing fillers, with the proviso that A, R1, and Z are substituents that will not protonate a pseudo-living polymer.

Abstract: In general the present invention provides a functionalized polymer prepared by a process comprising the steps of preparing a pseudo-living polymer by polymerizing conjugated monomer with a lanthanide-based catalyst, and reacting the pseudo-living polymer with a functionalizing agent defined by the formula (I) A-R1—Z??(I) where R1 is a divalent bond or divalent organic group comprising from 0 to about 20 carbon atoms, A is a substituent that will undergo an addition reaction with a pseudo-living polymer, and Z is a substituent that will react or interact with silica or carbon black reinforcing fillers, with the proviso that A, R1, and Z are substituents that will not protonate a pseudo-living polymer.

Abstract: A method for preparing a functionalized polymer comprising the steps of preparing a polymer by polymerizing conjugated diene monomer with a lanthanide-based catalyst, wherein the lanthanide-based catalyst comprises (a) a lanthanide compound, (b) an alkylating agent, and (c) a source of halogen, and reacting the pseudo-living polymer with at least one amide-containing functionalizing agent.

Abstract: A method for preparing a functionalized polymer comprising the steps of preparing a polymer by polymerizing conjugated diene monomer with a lanthanide-based catalyst, wherein the lanthanide-based catalyst comprises (a) a lanthanide compound, (b) an alkylating agent, and (c) a source of halogen, and reacting the pseudo-living polymer with at least one amide-containing functionalizing agent.

Abstract: A method for preparing a functionalized polymer comprising the steps of preparing a polymer by polymerizing conjugated diene monomer with a lanthanide-based catalyst, wherein the lanthanide-based catalyst comprises (a) a lanthanide compound, (b) an alkylating agent, and (c) a source of halogen, and reacting the pseudo-living polymer with at least one amide-containing functionalizing agent.

Abstract: A method for preparing a functionalized polymer comprising the steps of preparing a pseudo-living polymer by polymerizing conjugated diene monomer with a lanthanide-based catalyst, and reacting the pseudo-living polymer with at least one functionalizing agent defined by the formula (I) where A is a substituent that will undergo an addition reaction with a pseudo-living polymer, R1 is a divalent organic group, R2 is a monovalent organic group, and each R4, which may be the same or different, is a monovalent organic group or a substituent defined by —OR5 where R5 is a monovalent organic group, with the proviso that A, R1, R2, R4, and R5 are substituents that will not protonate a pseudo-living polymer. Also, the functionalized polymer and a vulcanizable composition containing the polymer.

Abstract: A method for preparing a functionalized polymer comprising the steps of preparing a polymer by polymerizing conjugated diene monomer with a lanthanide-based catalyst, wherein the lanthanide-based catalyst comprises (a) a lanthanide compound, (b) an alkylating agent, and (c) a source of halogen, and reacting the pseudo-living polymer with at least one amide-containing functionalizing agent.

Abstract: A functionalized polymer prepared by a process comprising the steps of preparing a pseudo-living polymer by polymerizing conjugated monomer with a lanthanide-based catalyst, and reacting the pseudo-living polymer with a functionalizing agent defined by the formula (I) A-R1-Z??(I) where R1 is a divalent bond or divalent organic group comprising from 0 to about 20 carbon atoms, A is a substituent that will undergo an addition reaction with a pseudo-living polymer, and Z is a substituent that will react or interact with silica or carbon black reinforcing fillers, with the proviso that A, R1, and Z are substituents that will not protonate a pseudo-living polymer.

Abstract: A method for preparing a functionalized polymer comprising the steps of preparing a pseudo-living polymer by polymerizing conjugated diene monomer with a lanthanide-based catalyst, and reacting the pseudo-living polymer with at least one functionalizing agent defined by the formula (I) where A is a substituent that will undergo an addition reaction with a pseudo-living polymer, R1 is a divalent organic group, R2 is a monovalent organic group, and each R4, which may be the same or different, is a monovalent organic group or a substituent defined by —OR5 where R5 is a monovalent organic group, with the proviso that A, R1, R2, R4, and R5 are substituents that will not protonate a pseudo-living polymer. Also, the functionalized polymer and a vulcanizable composition containing the polymer.

Abstract: A method for preparing a functionalized polymer comprising the steps of preparing a pseudo-living polymer by polymerizing conjugated diene monomer with a lanthanide-based catalyst, and reacting the pseudo-living polymer with at least one functionalizing agent defined by the formula (I) where A is a substituent that will undergo an addition reaction with a pseudo-living polymer, R1 is a divalent organic group, R2 is a monovalent organic group, and each R4, which may be the same or different, is a monovalent organic group or a substituent defined by —OR5 where R5 is a monovalent organic group, with the proviso that A, R1, R2, R4, and R5 are substituents that will not protonate a pseudo-living polymer. Also, the functionalized polymer and a vulcanizable composition containing the polymer.

Abstract: A functionalized polymer prepared by a process comprising the steps of preparing a pseudo-living polymer by polymerizing conjugated monomer with a lanthanide-based catalyst, and reacting the pseudo-living polymer with a functionalizing agent defined by the formula (I) A-R1-Z??(I) where R1 is a divalent bond or divalent organic group comprising from 0 to about 20 carbon atoms, A is a substituent that will undergo an addition reaction with a pseudo-living polymer, and Z is a substituent that will react or interact with silica or carbon black reinforcing fillers, with the proviso that A, R1, and Z are substituents that will not protonate a pseudo-living polymer.

Abstract: Disclosure is herein made of a rubber composition containing at least 30% by weight of a butadiene copolymer which is characterized in that: (i) the content of vinyl bonds in a polybutadiene portion is from 40 to 70%; (ii) the content of bound vinyl aromatic compound is from 25 to 50% by weight: (iii) the ratio Mw/Mn between the weight average molecular weight (Mw) and the number average molecular weight (Mn) when calculated as polystyrene according to the gel permeation chromatograph (GPC) method is from 1.8 to 5, and the distribution of the molecular weight is unimodal; (iv) the rate of the copolymer having the weight average molecular weight of not more than 100,000 when calculated as polystyrene is from 10 to 30%; (v) the rate of the copolymer having the weight average molecular weight of not less than 2,000,000 when calculated as polystyrene is from 10 to 30%; and (vi) the Mooney viscosity (ML.sub.1+4 100.degree. C.) is from 20 to 100.

Abstract: There is a tire having tire performances such as wear resistance, cut resistance, heat build-up and the like and a processability simultaneously and economically improved by the application of a rubber composition containing a rubbery polymer modified with a silane compound and silica. The rubbery polymer modified with the silane compound is obtained by reacting an active terminal of a living polymer, which is obtained by polymerizing a monomer in the presence of an organic alkali metal catalyst, with a silane compound represented by the following general formula:X.sub.n Si(OR).sub.m R'.sub.4-m-n(where X is a halogen atom selected from a chlorine atom, a bromine atom and an iodine atom, OR is a non-hydrolyzable alkoxy group having a carbon number of 4.about.20, an aryloxy group or a cycloalkoxy group, R' is an alkyl group having a carbon number of 1.about.20, an aryl group, a vinyl group or a halogenated alkyl group, m is an integer of 1.about.4, n is an integer of 0.about.2, and a sum of n and m is 2.about.

Abstract: A rubber composition for tire having improved processability, wear resistance, rebound resilience and heat build-up comprises 20.about.70 parts by weight of a specified butadiene polymer, 30.about.80 parts by weight of at least one rubber selected from natural rubber, high cis-1,4 polyisoprene rubber and styrene-butadiene copolymer rubber, and 0.about.30 parts by weight of high cis-1,4 polybutadiene and/or low cis-1,4 polybutadiene, and contains 35.about.100 parts by weight of carbon black, 0.about.50 parts by weight of process oil, 0.5.about.5 parts by weight of aliphatic carboxylic acid and 0.1.about.3 parts by weight of sulfur based on 100 parts by weight of the above rubber components.

Abstract: A rubber composition is disclosed which contains not less than 20% by weight in a rubber component of a block copolymer composed of polymer or copolymer block units (A) and a random copolymer block units (B). The polymer or copolymer block units (A) are obtained by singly polymerizing a conjugated diolefine or copolymerizing the conjugated diolefine and a monovinyl aromatic hydrocarbon with use of a lithium initiator and contains not more than 10% by weight of the bound monovinyl aromatic hydrocarbon. The random copolymer block unit (B) are obtained by copolymerizing the conjugated diolefine and the monovinyl aromatic hydrocarbon and contain 15 to 80% by weight of the bound monovinyl aromatic hydrocarbon.

Abstract: A rubber composition comprising not less than 20% by weight of an amino group-containing diene based polymer in a rubber component, and 10 to 100 parts by weight of silica as a filler with respect to 100 parts by weight of the rubber component. The amino group-containing diene based polymer is obtained by polymerizing a monomer or copolymerizing the monomer in an organic solvent in the presence of at least one of an organic alkali metal and an organic alkaline earth metal.

Abstract: Disclosed is a novel rubber composition for the treads of high-performance tires including racing tires. The elastomer component of the rubber composition consists essentially of 10-60 wt % of a low molecular weight copolymer of an aliphatic diene, e.g. butadiene, and an aromatic vinyl compound, e.g. styrene, and the balance of a conventional diene rubber such as a high styrene styrene-butadiene rubber. The copolymer is the product of solution copolymerization reaction of the aliphatic and aromatic monomers in a hydrocarbon solvent using an organic lithium compound as the initiator, and the molecular weight of the copolymer is from about 2000 to about 50000. The rubber composition provides very high road gripping ability and is sufficiently high also in rupture strength, heat resistance and wear resistance.

Abstract: A conjugated diene series rubber composition comprises, as a rubber component, (a) 20.about.100% by weight of a particular conjugated diene polymer and (b) a diene polymer rubber except for the polymer (a) and is excellent in the processability at unvulcanized state and the rebound resilience, strengths at rupture and wear resistance at vulcanized state.