A heterophasic polypropylene copolymer having an MFR2 of 0.05 to 20 g/10 min (ISO 1133 at 230° C. with a loading of 2.16 kg) and a melting point (Tm) of 156 to 164° C. (measured by DSC according to ISO 11357) wherein the heterophasic polypropylene copolymer comprises at least the following components: (A) 55.0 to 95.0 wt % of a crystalline fraction (CF) having a comonomer content of 0 to 3.0 wt %; and (B) 5.0 to 45.0 wt % of a soluble fraction (SF) having a comonomer content of 12 to 45 wt %; wherein the intrinsic viscosity (IV) (in decalin at 135° C.) of the soluble fraction (SF) is 2.5 to 11 dl/g, and wherein the amount of crystalline fraction (CF) and the amount of soluble fraction (SF) are determined in 1,2,4-trichlorobenzene at 40° C.

A process for propylene preliminary polymerization in liquid phase that occurs in a continuous preliminary polymerization reactor may include feeding a propylene monomer and a Ziegler-Natta catalyst system having (a) a pro-catalyst having an internal electron donor comprising a substituted phenylene aromatic diester, (b) a catalyst activator and optionally (c) an external donor, into the continuous preliminary polymerization reactor, wherein the feeding is carried out without pre-contact of the pro-catalyst with the catalyst activator, and also without pre-contact of the catalyst activator with the propylene monomer before entering the continuous preliminary polymerization reactor.

A process for propylene preliminary polymerization in liquid phase that occurs in a continuous preliminary polymerization reactor may include feeding a propylene monomer and a Ziegler-Natta catalyst system having (a) a pro-catalyst having an internal electron donor comprising a substituted phenylene aromatic diester, (b) a catalyst activator and optionally (c) an external donor, into the continuous preliminary polymerization reactor, wherein the feeding is carried out without pre-contact of the pro-catalyst with the catalyst activator, and also without pre-contact of the catalyst activator with the propylene monomer before entering the continuous preliminary polymerization reactor.

Embodiments are directed towards the use of a supported biphenylphenol polymerization catalyst made from a biphenylphenol polymerization precatalyst of Formula I via a gas-phase or slurry-phase polymerization process under gas-phase or slurry-phase polymerization conditions to make a polymer.

Embodiments are directed towards the use of a supported biphenylphenol polymerization catalyst made from a biphenylphenol polymerization precatalyst of Formula I via a gas-phase or slurry-phase polymerization process under gas-phase or slurry-phase polymerization conditions to make a polymer.

An ultra-high molecular weight, ultra-fine particle size polyethylene has a viscosity average molecular weight (Mv) greater than 1×10.sup.6. The polyethylene is spherical or are sphere-like particles having a mean particle size of 10-100 μm, having a standard deviation of 2-15 μm and a bulk density of 0.1-0.3 g/mL. Using the polyethylene as a basic polyethylene, a grafted polyethylene can be obtained by means of a solid-phase grafting method; and a glass fiber-reinforced polyethylene composition comprising the polyethylene and glass fibers, and a sheet or pipe prepared therefrom; a solubilized ultra-high molecular weight, ultra-fine particle size polyethylene; and a fiber and a film prepared from the solubilized ultra-high molecular weight, ultra-fine particle size polyethylene may also be obtained. The method has simple steps, is easy to control, has a relatively low cost and a high repeatability, and can realize industrialisation.

An ultra-high molecular weight, ultra-fine particle size polyethylene has a viscosity average molecular weight (Mv) greater than 1×10.sup.6. The polyethylene is spherical or are sphere-like particles having a mean particle size of 10-100 μm, having a standard deviation of 2-15 μm and a bulk density of 0.1-0.3 g/mL. Using the polyethylene as a basic polyethylene, a grafted polyethylene can be obtained by means of a solid-phase grafting method; and a glass fiber-reinforced polyethylene composition comprising the polyethylene and glass fibers, and a sheet or pipe prepared therefrom; a solubilized ultra-high molecular weight, ultra-fine particle size polyethylene; and a fiber and a film prepared from the solubilized ultra-high molecular weight, ultra-fine particle size polyethylene may also be obtained. The method has simple steps, is easy to control, has a relatively low cost and a high repeatability, and can realize industrialisation.

Activators may comprise compounds represented by the Formula [Ar(EHR.sup.1R.sup.2)(OR.sup.3)]d+[M.sup.k+Q.sub.n].sup.d, wherein: Ar is an aryl group; E is nitrogen or phosphorous; R.sup.1 is a C.sub.1-C.sub.30, optionally substituted, linear alkyl group; R.sup.2 is a C.sub.1-C.sub.30, optionally substituted, linear alkyl group; R.sup.3 is a C.sub.10-C.sub.30, optionally substituted, linear alkyl group; M is an element selected from group 13 of the Periodic Table of the Elements; d is 1, 2 or 3; k is 1, 2, or 3; n is 1, 2, 3, 4, 5, or 6; n−k=d; and each Q is independently hydride, bridged or unbridged dialkylamido, halide, alkoxide, aryloxide, hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, or halosubstituted-hydrocarbyl radical. Catalysts systems may comprise these activators and methods of preparing polyolefins may use these catalysts systems.

Activators may comprise compounds represented by the Formula [Ar(EHR.sup.1R.sup.2)(OR.sup.3)]d+[M.sup.k+Q.sub.n].sup.d, wherein: Ar is an aryl group; E is nitrogen or phosphorous; R.sup.1 is a C.sub.1-C.sub.30, optionally substituted, linear alkyl group; R.sup.2 is a C.sub.1-C.sub.30, optionally substituted, linear alkyl group; R.sup.3 is a C.sub.10-C.sub.30, optionally substituted, linear alkyl group; M is an element selected from group 13 of the Periodic Table of the Elements; d is 1, 2 or 3; k is 1, 2, or 3; n is 1, 2, 3, 4, 5, or 6; n−k=d; and each Q is independently hydride, bridged or unbridged dialkylamido, halide, alkoxide, aryloxide, hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, or halosubstituted-hydrocarbyl radical. Catalysts systems may comprise these activators and methods of preparing polyolefins may use these catalysts systems.

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.