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, where said pseudo-living polymer is characterized by having greater than about 85 percent of the polymer in the cis microstructure and less than about 3 percent of the polymer is in the 1,2- or 3,4-microstructure, and reacting the pseudo-living polymer with at least one functionalizing agent defined by the formula (I) or (II) where Z is a substituent that will react or interact with organic or inorganic fillers; R1 is a single bond or a divalent organic group; R2 is a monovalent organic group or a divalent organic group that forms a cyclic organic group with R13 or R14; R3 is a single bond, a divalent organic group, or a trivalent organic group that forms a cyclic organic group with R4 or R5; R13 is a single bond, a divalent organic group, or a trivalent organic group that forms a cyclic organic group with R2 or R14; R4 is a m

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: 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, where said pseudo-living polymer is characterized by having greater than about 85 percent of the polymer in the cis microstructure and less than about 3 percent of the polymer is in the 1,2- or 3,4-microstructure, and reacting the pseudo-living polymer with at least one functionalizing agent defined by the formula (I) or (II) where Z is a substituent that will react or interact with organic or inorganic fillers; R1 is a single bond or a divalent organic group; R2 is a monovalent organic group or a divalent organic group that forms a cyclic organic group with R13 or R14; R3 is a single bond, a divalent organic group, or a trivalent organic group that forms a cyclic organic group with R4 or R5; R13 is a single bond, a divalent organic group, or a trivalent organic group that forms a cyclic organic group with R2 or R14; R4 is a mo

Abstract: A rubber composition comprising as a rubber component a specified styrene-butadiene copolymer (A) and a styrene-isoprene copolymer of a specified hydrogenation ratio (B) wherein a bound styrene content of the copolymer (B) is larger by a given value than a bound styrene content of the copolymer (A) is good in the wear resistance and fracture property and further excellent in the wet-skid resistance and dry gripping property.

Abstract: A continuous process for producing conjugated diene polymers comprising the steps of contacting, within an hydrocarbon solvent and within a continuous reactor, conjugated diene monomer and a catalyst composition prepared by combining: (a) a lanthanide compound, (b) an alkylating agent, and (c) a halogen-containing compound, and maintaining a non-ideal flow pattern within the continuous reactor so that 10% of the reagents entering the reactor at a reference time t0 are still present within the continuous reactor at a time t0+xtrt, where trt is the residence time corresponding to ideal flow within the continuous reactor and x is a numeral greater than 1.5.

Abstract: A continuous process for producing conjugated diene polymers comprising the steps of contacting, within an hydrocarbon solvent and within a continuous reactor, conjugated diene monomer and a catalyst composition prepared by combining: (a) a lanthanide compound, (b) an alkylating agent, and (c) a halogen-containing compound, and maintaining a non-ideal flow pattern within the continuous reactor so that 10% of the reagents entering the reactor at a reference time t0 are still present within the continuous reactor at a time t0+xtrt, where trt is the residence time corresponding to ideal flow within the continuous reactor and x is a numeral greater than 1.5.

Abstract: A catalyst composition that is the combination of or the reaction product of ingredients comprising (a) an lanthanide compound, (b) an alkylating agent, (c) a nickel-containing compound, and optionally (d) a halogen-containing compound, with the proviso that the halogen-containing compound must be present where none of the lanthanide compound, the alkylating agent, and the nickel-containing compound contain a labile halogen atom.

Abstract: A catalyst composition that is the combination of or the reaction product of ingredients comprising (a) an lanthanide compound, (b) an alkylating agent, (c) a nickel-containing compound, and optionally (d) a halogen-containing compound, with the proviso that the halogen-containing compound must be present where none of the lanthanide compound, the alkylating agent, and the nickel-containing compound contain a labile halogen atom.

Abstract: A stabilized high-vinyl polybutadiene composition comprising a high-vinyl polybutadiene, and an antioxidant defined by the formula 1

Abstract: A rubber composition comprises, as a softener, a polymer obtained by cationic polymerization using a Lewis acid catalyst as an initiator. The polymer may be substantially a homopolymer of isobutylene, or substantially a copolymer of isobutylene and an aromatic vinyl compound. The homopolymer of isobutylene may be copolymerized with a conjugated diene monomer. The aromatic vinyl compound in the polymer may be styrene. In accordance with the present invention, a rubber composition exhibiting an excellent high hysteresis loss property without adverse effects on fracture properties can be provided. A pneumatic tire exhibiting excellent gripping ability can be provided by using the rubber composition in a tread.