A styrene-isoprene/butadiene diblock copolymer contains a polystyrene block and a polyisoprene/butadiene block. Based on 100 wt % of the styrene-isoprene/butadiene diblock copolymer, the polystyrene block is 20-45 wt %, and the polyisoprene/butadiene block is 55-80 wt %. The polyisoprene/butadiene block has a polyisoprene unit and a polybutadiene unit. The weight ratio of the polyisoprene unit to the polybutadiene unit is 8:2 to 2:8.

To provide a catalyst composition having high polymerization activity. To provide a polymer manufacturing method. To provide a polymer manufactured by the polymer manufacturing method. To provide a rubber composition including the polymer. To provide a tire using the rubber composition. A catalyst composition including a compound represented by Structural Formula I below, wherein the compound has an OH group at at least one position of the bipyridyl ring; M is a transition metal, a lanthanoid, scandium, or yttrium; R.sup.1 and R.sup.2 are a hydrocarbon group having one or more carbon atoms or a halogen atom; and R.sup.1 and R.sup.2 may be the same or different from each other. A polymer manufacturing method including a step of polymerizing one or more selected from the group consisting of a conjugated diene compound and a compound having an ethylenically unsaturated double bond in the presence of the catalyst composition. A polymer manufactured by the manufacturing method. A rubber composition including the polymer. A tire using the rubber composition. ##STR00001##

To provide a catalyst composition having high polymerization activity. To provide a polymer manufacturing method. To provide a polymer manufactured by the polymer manufacturing method. To provide a rubber composition including the polymer. To provide a tire using the rubber composition. A catalyst composition including a compound represented by Structural Formula I below, wherein the compound has an OH group at at least one position of the bipyridyl ring; M is a transition metal, a lanthanoid, scandium, or yttrium; R.sup.1 and R.sup.2 are a hydrocarbon group having one or more carbon atoms or a halogen atom; and R.sup.1 and R.sup.2 may be the same or different from each other. A polymer manufacturing method including a step of polymerizing one or more selected from the group consisting of a conjugated diene compound and a compound having an ethylenically unsaturated double bond in the presence of the catalyst composition. A polymer manufactured by the manufacturing method. A rubber composition including the polymer. A tire using the rubber composition. ##STR00001##

The present invention relates to a rubber composition having excellent abrasion resistance and improved tensile properties and viscoelasticity properties by controlling compatibility among rubber components, and a tire manufactured using the same.

The present invention relates to a rubber composition having excellent abrasion resistance and improved tensile properties and viscoelasticity properties by controlling compatibility among rubber components, and a tire manufactured using the same.

It has been unexpectedly found that certain neodymium catalyst systems can be used to copolymerize isoprene and 1,3-butadiene to produce random isoprene-butadiene copolymer rubbers which are not tapered. These random isoprene-butadiene copolymer rubbers have properties which are beneficial for use in rubber formulations for manufacturing a wide variety of rubber products, such as tires, hoses, conveyor belts, power transmission belts, and shoe soles. These random isoprene-butadiene rubbers are synthesized by copolymerizing (a) isoprene monomer or a substituted isoprene monomer and (b) 1,3-butadiene monomer in the presence of a neodymium catalyst system, wherein the neodymium catalyst system is prepared by (1) reacting a neodymium carboxylate with an organoaluminum compound in the presence of a conjugated diolefin monomer to produce neodymium-aluminum catalyst component, and (2) subsequently reacting the neodymium-aluminum catalyst component with an alkyl aluminum chloride to produce the neodymium catalyst system.

It has been unexpectedly found that certain neodymium catalyst systems can be used to copolymerize isoprene and 1,3-butadiene to produce random isoprene-butadiene copolymer rubbers which are not tapered. These random isoprene-butadiene copolymer rubbers have properties which are beneficial for use in rubber formulations for manufacturing a wide variety of rubber products, such as tires, hoses, conveyor belts, power transmission belts, and shoe soles. These random isoprene-butadiene rubbers are synthesized by copolymerizing (a) isoprene monomer or a substituted isoprene monomer and (b) 1,3-butadiene monomer in the presence of a neodymium catalyst system, wherein the neodymium catalyst system is prepared by (1) reacting a neodymium carboxylate with an organoaluminum compound in the presence of a conjugated diolefin monomer to produce neodymium-aluminum catalyst component, and (2) subsequently reacting the neodymium-aluminum catalyst component with an alkyl aluminum chloride to produce the neodymium catalyst system.

It has been unexpectedly found that certain neodymium catalyst systems can be used to copolymerize isoprene and 1,3-butadiene to produce random isoprene-butadiene copolymer rubbers which are not tapered. These random isoprene-butadiene copolymer rubbers have properties which are beneficial for use in rubber formulations for manufacturing a wide variety of rubber products, such as tires, hoses, conveyor belts, power transmission belts, and shoe soles. These random isoprene-butadiene rubbers are synthesized by copolymerizing (a) isoprene monomer or a substituted isoprene monomer and (b) 1,3-butadiene monomer in the presence of a neodymium catalyst system, wherein the neodymium catalyst system is prepared by (1) reacting a neodymium carboxylate with an organoaluminum compound in the presence of a conjugated diolefin monomer to produce neodymium-aluminum catalyst component, and (2) subsequently reacting the neodymium-aluminum catalyst component with an alkyl aluminum chloride to produce the neodymium catalyst system.

Butadiene-isoprene diblock copolymer formed by a block of crystalline polybutadiene (hard block) and by a block of amorphous polyisoprene (soft block). Said butadiene-isoprene diblock copolymer can be advantageously used both in the footwear industry (for example, in the production of shoe soles), and in the production of tires for motor vehicles and/or trucks.

The present invention relates to a method for halogenating an isobutene-isoprene copolymer by using an organic hypochlorite. By using the method of the present invention, a hydrogen halide byproduct may be rapidly recycled into a halogenating agent and reused. As a result, a halogenated isobutene-isoprene copolymer having the high content of secondary allyl halogen functional groups may be prepared by increasing the participation ratio of the halogenating agent in reaction and suppressing the rearrangement of the secondary allyl halogen functional groups. The halogenated isobutene-isoprene copolymer prepared according to the present invention may be effectively used in the crosslinking reaction with other rubber, and is industrially useful.