Modified diene polymers containing heteroatoms are disclosed, as is their production, rubber mixtures comprising these modified diene rubbers, and to their use for the production of rubber vulcanizates, which serve, in particular, for the production of rubber moldings and the production of tires.

Modified diene polymers containing heteroatoms are disclosed, as is their production, rubber mixtures comprising these modified diene rubbers, and to their use for the production of rubber vulcanizates, which serve, in particular, for the production of rubber moldings and the production of tires.

To provide a fluorinated copolymer capable of producing a cross-linked rubber article with excellent mold-releasing properties, a method for producing the fluorinated copolymer, a fluorinated copolymer composition, and a cross-linked rubber article. The fluorinated copolymer of the present invention is a fluorinated copolymer having units based on tetrafluoroethylene, units based on a perfluoro(alkyl vinyl ether), units based on a monomer having a fluorine atom and at least two polymerizable unsaturated bonds, and units based on a monomer having a nitrile group and a fluorine atom, wherein when the storage modulus of the fluorinated copolymer at an angular frequency of 0.3 rad/s is G.sub.0.3 and the storage modulus of the fluorinated copolymer at an angular frequency of 0.03 rad/s is G.sub.0.03 as determined by dynamic viscoelasticity measurement at 140 C., G.sub.0.3/G.sub.0.03 is from 1.00 to 1.45.

To provide a fluorinated copolymer capable of producing a cross-linked rubber article with excellent mold-releasing properties, a method for producing the fluorinated copolymer, a fluorinated copolymer composition, and a cross-linked rubber article. The fluorinated copolymer of the present invention is a fluorinated copolymer having units based on tetrafluoroethylene, units based on a perfluoro(alkyl vinyl ether), units based on a monomer having a fluorine atom and at least two polymerizable unsaturated bonds, and units based on a monomer having a nitrile group and a fluorine atom, wherein when the storage modulus of the fluorinated copolymer at an angular frequency of 0.3 rad/s is G.sub.0.3 and the storage modulus of the fluorinated copolymer at an angular frequency of 0.03 rad/s is G.sub.0.03 as determined by dynamic viscoelasticity measurement at 140 C., G.sub.0.3/G.sub.0.03 is from 1.00 to 1.45.

Conjugated diene polymers such as a styrene-butadiene copolymer are sequentially brominated by reaction with a quaternary ammonium tribromide or quaternary phosphonium tribromide and halohydrated by reaction with an N-haloimide compound. This produces a brominated and halohydrated polymer with very good thermal stability. The product is useful as a flame retardant in a variety of polymer systems.

Conjugated diene polymers such as a styrene-butadiene copolymer are sequentially brominated by reaction with a quaternary ammonium tribromide or quaternary phosphonium tribromide and halohydrated by reaction with an N-haloimide compound. This produces a brominated and halohydrated polymer with very good thermal stability. The product is useful as a flame retardant in a variety of polymer systems.

A conjugated diene polymer having a high content of cis-1,4-structures with a high activity, a conjugated diene polymer and a modified conjugated diene polymer using the same, a rubber composition for a tire, and a rubber composition for a rubber belt. Described are a catalyst for a conjugated diene polymerization including: a non-metallocene type gadolinium compound (A) represented by the general formula (1); an ionic compound (B) formed of a non-coordinating anion and a cation; and an organic metal compound (C) of an element selected from the group consisting of a group 2, a group 12, and a group 13 of the periodic table, a conjugated diene polymer and a modified conjugated diene polymer obtained using the same, a rubber composition for a tire, and a rubber composition for a rubber belt.

A conjugated diene polymer having a high content of cis-1,4-structures with a high activity, a conjugated diene polymer and a modified conjugated diene polymer using the same, a rubber composition for a tire, and a rubber composition for a rubber belt. Described are a catalyst for a conjugated diene polymerization including: a non-metallocene type gadolinium compound (A) represented by the general formula (1); an ionic compound (B) formed of a non-coordinating anion and a cation; and an organic metal compound (C) of an element selected from the group consisting of a group 2, a group 12, and a group 13 of the periodic table, a conjugated diene polymer and a modified conjugated diene polymer obtained using the same, a rubber composition for a tire, and a rubber composition for a rubber belt.

The invention relates to an energy efficient, fast and environmentally favourable process for the preparation of chlorinated butyl rubbers, that uses hypochlorous acid (HOCl) and/or dichlorine monoxide (Cl.sub.2O) as halogenating agent. The process comprises reacting a copolymer with hypochlorous acid and/or dichlorine oxide. The copolymer comprises units derived from an isoolefin monomer and units derived from a multiolefin monomer. A preferred isoolefin is isobutene and a preferred multiolefin is isoprene.

The invention relates to an energy efficient, fast and environmentally favourable process for the preparation of chlorinated butyl rubbers, that uses hypochlorous acid (HOCl) and/or dichlorine monoxide (Cl.sub.2O) as halogenating agent. The process comprises reacting a copolymer with hypochlorous acid and/or dichlorine oxide. The copolymer comprises units derived from an isoolefin monomer and units derived from a multiolefin monomer. A preferred isoolefin is isobutene and a preferred multiolefin is isoprene.