To provide a method for producing a multicomponent copolymer with which a multicomponent copolymer having excellent rupture strength can be obtained, and a multicomponent copolymer, a rubber composition and a tire having excellent rupture strength. The method is a method for producing a multicomponent copolymer having a conjugated diene unit, a non-conjugated olefin unit and an aromatic vinyl unit, comprising adding a conjugated diene compound in divided portions into a reactor containing a catalyst and at least one selected from the group consisting of a non-conjugated olefin compound and an aromatic vinyl compound. The multicomponent copolymer is obtained with the production method. The rubber composition comprises the multicomponent copolymer as a rubber component. The tire uses the rubber composition.

Provided is a polyethylene powder having a density of 910 kg/m.sup.3 or more and less than 935 kg/m.sup.3 and an average particle diameter of 50 μm or more and less than 140 μm, wherein the polyethylene powder contains a particle having a particle diameter of 60 μm and a particle having a particle diameter of 100 μm, the compressive strength at 10% displacement of the particle having a particle diameter of 60 μm is 2.0 MPa or more and less than 5.0 MPa, and the compressive strength at 10% displacement of the particle having a particle diameter of 60 μm is 0.5 times or more and less than 1.3 times the compressive strength at 10% displacement of the particle having a particle diameter of 100 μm.

Provided is a polyethylene powder having a density of 910 kg/m.sup.3 or more and less than 935 kg/m.sup.3 and an average particle diameter of 50 μm or more and less than 140 μm, wherein the polyethylene powder contains a particle having a particle diameter of 60 μm and a particle having a particle diameter of 100 μm, the compressive strength at 10% displacement of the particle having a particle diameter of 60 μm is 2.0 MPa or more and less than 5.0 MPa, and the compressive strength at 10% displacement of the particle having a particle diameter of 60 μm is 0.5 times or more and less than 1.3 times the compressive strength at 10% displacement of the particle having a particle diameter of 100 μm.

Provided is a propylene homopolymer or a copolymer of propylene and a 30 wt % or less α-olefin having 2 or 4 to 8 carbon atoms, having a intrinsic viscosity of more than 20 dl/g, as measured in a tetralin solvent at 135° C.

Provided is a propylene homopolymer or a copolymer of propylene and a 30 wt % or less α-olefin having 2 or 4 to 8 carbon atoms, having a intrinsic viscosity of more than 20 dl/g, as measured in a tetralin solvent at 135° C.

The invention relates to an efficient process for the preparation and isolation of rubber particles formed in aqueous media and highly pure rubbers obtained thereby. The invention further relates to copolymer products comprising the same or derived therefrom.

The invention relates to an efficient process for the preparation and isolation of rubber particles formed in aqueous media and highly pure rubbers obtained thereby. The invention further relates to copolymer products comprising the same or derived therefrom.

Disclosed herein are ethylene-based polymers generally characterized by a density of at least 0.94 g/cm.sup.3, a high load melt index from 4 to 20 g/10 min, a zero-shear viscosity at 190° C. from 20,000 to 400,000 kPa-sec, and a relaxation time at 190° C. from 225 to 3000 sec. These ethylene polymers can be produced by peroxide-treating a broad molecular weight distribution Ziegler-catalyzed resin, and can be used in large diameter, thick wall pipes and other end-use applications.

The present invention relates to compounds according to formula I:

##STR00001##

wherein: each R1-R10 may individually be H, a halogen, an alkoxy moiety, a siloxy moiety, a nitrogen-containing moiety, an alkyl moiety, an aryl moiety, or an aralkyl moiety, wherein each R1-R10 comprises ≤10 carbon atoms, wherein each of R1-R10 may form a cyclic moiety with an adjacent R1-R10 moiety; Y is O or N—R11, wherein R11 is an alkyl, cycloalkyl, aryl or aralkyl moiety comprising 1-12 carbon atoms; M is a group 3 or 4 transition metal; X is a sigma-bonded ligand, or a diene; z is the number of ligands X that are bonded to M. Such compounds may be used in a catalyst system for olefin polymerisation.

The present invention relates to compounds according to formula I:

##STR00001##

wherein: each R1-R10 may individually be H, a halogen, an alkoxy moiety, a siloxy moiety, a nitrogen-containing moiety, an alkyl moiety, an aryl moiety, or an aralkyl moiety, wherein each R1-R10 comprises ≤10 carbon atoms, wherein each of R1-R10 may form a cyclic moiety with an adjacent R1-R10 moiety; Y is O or N—R11, wherein R11 is an alkyl, cycloalkyl, aryl or aralkyl moiety comprising 1-12 carbon atoms; M is a group 3 or 4 transition metal; X is a sigma-bonded ligand, or a diene; z is the number of ligands X that are bonded to M. Such compounds may be used in a catalyst system for olefin polymerisation.