Provided is a multi-component copolymer having high elasticity and excellent low heat generating property. The multi-component copolymer comprises conjugated diene units, non-conjugated olefin units and aromatic vinyl units, wherein: a peak top molecular weight of non-conjugated olefin parts linking only the non-conjugated olefin units is 40,000 or more.

Provided is a multi-component copolymer having high elasticity and excellent low heat generating property. The multi-component copolymer comprises conjugated diene units, non-conjugated olefin units and aromatic vinyl units, wherein: a peak top molecular weight of non-conjugated olefin parts linking only the non-conjugated olefin units is 40,000 or more.

A block copolymer and a method for preparing the same are disclosed. The method comprises the following steps: (A) mixing a compound of formula (I), a catalyst of formula (II), and a first solvent to obtain a first mixture; (B) adding a first monomer into the first mixture for reaction to obtain a second mixture; and (C) adding a second monomer into the second mixture for reaction to obtain a third mixture; wherein the compound of formula (I) and the catalyst of formula (II) are as defined in the specification.

A tyre for wheels of vehicles, in particular motor vehicles, is described. The tyre has a tread with at least one copolymer of (iso-styrene/trans-butadiene): diene-terminated copolymers. The tread has less sensitivity to the effects of temperature, with less weakness, better consistancy of performances, and improved characteristics in terms of grip and/or resistance to laceration.

A tyre for wheels of vehicles, in particular motor vehicles, is described. The tyre has a tread with at least one copolymer of (iso-styrene/trans-butadiene): diene-terminated copolymers. The tread has less sensitivity to the effects of temperature, with less weakness, better consistancy of performances, and improved characteristics in terms of grip and/or resistance to laceration.

Metallic complexes having indenyl ligands can be used as an ingredient of a catalyst system. The catalyst system can be used in polymerizations of ethylenically unsaturated hydrocarbon monomers that include both olefins and polyenes. Embodiments of the catalyst system can provide interpolymers that include polyene mer and from 40 to 75 mole percent ethylene mer, with a plurality of the ethylene mer being randomly distributed. The catalyst system also can be used in solution polymerizations conducted in C.sub.5-C.sub.12 alkanes, yielding interpolymers that include at least 10 mole percent ethylene mer.

Metallic complexes having indenyl ligands can be used as an ingredient of a catalyst system. The catalyst system can be used in polymerizations of ethylenically unsaturated hydrocarbon monomers that include both olefins and polyenes. Embodiments of the catalyst system can provide interpolymers that include polyene mer and from 40 to 75 mole percent ethylene mer, with a plurality of the ethylene mer being randomly distributed. The catalyst system also can be used in solution polymerizations conducted in C.sub.5-C.sub.12 alkanes, yielding interpolymers that include at least 10 mole percent ethylene mer.

Provide is a polymer that can provide excellent toughness and weather resistance to a rubber composition and a rubber product such as a tire. The multicomponent copolymer contains a conjugated diene unit, a non-conjugated olefin unit and an aromatic vinyl unit, where a proportion of conjugated diene units bonded to a unit other than a conjugated diene unit out of the total conjugated diene units is 50% or more.

A vulcanizable composition comprising rubber component, a filler, and a curing agent, where the rubber component includes a block copolymer of polybutadiene and polyisoprene, and where the block copolymer has a cis content of at least 90%.

A method for producing a propylene-based block copolymer produces a propylene-based copolymer that exhibits excellent stereoregularity, rigidity, and impact resistance in a convenient and efficient manner while achieving high polymerization activity. The method for producing a propylene-based block copolymer includes bringing a catalyst into contact with propylene, or propylene and an -olefin, and bringing an electron donor compound into contact with the resulting product to produce a propylene-based block copolymer, the catalyst including a solid catalyst component that includes titanium, magnesium, a halogen, and an internal electron donor compound, a specific organoaluminum compound, and a specific external electron donor compound.