The invention relates to a process for the preparation of a heterophasic propylene copolymer consisting of a propylene-based matrix and a dispersed ethylene--olefin copolymer, comprising the steps of a) preparing the propylene-based matrix from propylene and optionally a C2 or C4-C12 -olefin by contacting at least propylene and optionally C2 or C4-C12 -olefin with a catalyst in a first gas-phase reactor at a temperature T1 and a pressure P1, b) subsequently preparing the dispersed ethylene--olefin copolymer from ethylene and a C3-C12 -olefin by contacting the ethylene and the C3-C12 -olefin with a catalyst in a second gas-phase reactor at a temperature T2 and a pressure P2, wherein T1T2 is in the range from 6 to 25 C., wherein T1>T2, wherein P1 and P2 are in the range from 22 to 30 bar to prepare a heterophasic propylene copolymer (A).

The present invention provides an olefin coordination polymerization catalyst and use thereof. The composition of the raw materials of the olefin coordination polymerization catalyst comprises: a main catalyst and a cocatalyst, wherein a molar ratio of the transition metal halide in the main catalyst to the cocatalyst is 1:10-500; and the composition of the raw materials of the main catalyst comprises a magnesium compound, a transition metal halide, an alcohol having 2 to 15 carbon atoms, and a star-shaped organosiloxane compound in a molar ratio of 1:1-40:0.01-10:0.001-10; and the cocatalyst comprises an organoaluminum compound. The above olefin coordination polymerization catalyst is used as a catalyst for ethylene polymerization, propylene polymerization, and copolymerization of ethylene or propylene with an -olefin. The olefin polymerization catalyst of the present invention has good catalytic activity.

The invention relates to a process for preparing a solid support for a procatalyst suitable for preparing a catalyst composition for olefin polymerization, said process for preparing said solid support comprising reacting a compound R.sup.4.sub.2MgX.sup.4.sub.2-z with a silane compound Si(OR.sup.5).sub.4-n(R.sup.6).sub.n in a solvent and mixing the resulting mixture with a mixing device and at a certain mixing speed in order to give a solid support Mg(OR.sup.1).sub.xX.sup.1.sub.2-x said solid support obtained having an average particle size of at most 17 m, preferably at most 16 or 14 m, more preferably at most 12 m. The invention further relates to a solid support, a process for preparing a procatalyst and said procatalyst as well as polyolefins obtained using said procatalyst.

The present invention relates to a process for preparing a solid catalyst component suitable for producing polyethylene and its copolymers, said process comprising the steps of: (a) contacting a dehydrated support having hydroxyl groups with a magnesium compound having the general formula MgR.sup.1R.sup.2; (b) contacting the product obtained in step (a) with modifying compounds (A) and/or (B) and/or (C), wherein: (A) is at least one oxygen and/or nitrogen comprising organic compound; (B) is a compound having the general formula R.sup.11.sub.f(R.sup.12O).sub.gSiX.sub.h, (C) is a compound having the general formula (R.sup.13O).sub.4M, and (c) contacting the product obtained in step (b) with a titanium halide compound having the general formula TiX.sub.4, wherein Ti is a titanium atom and X is a halide atom, wherein an organometallic compound is added either before step (a) and/or after step (c). The invention also relates to a solid catalyst component obtainable by said process. The invention further relates to a process for producing polyethylene and its copolymers in the presence of the solid catalyst component and a co-catalyst.

The present invention relates to a process for preparing a solid catalyst component suitable for producing polyethylene and its copolymers, said process comprising the steps of: (a) contacting a dehydrated support having hydroxyl groups with a magnesium compound having the general formula MgR.sup.1R.sup.2; (b) contacting the product obtained in step (a) with modifying compounds (A) and/or (B) and/or (C), wherein: (A) is an 4-amino-pent-3-en-2-one; (B) is a compound having the general formula R.sup.11.sub.f(R.sup.12O).sub.g,SiX.sub.h, (C) is a compound having the general formula (R.sup.13O).sub.4M, and (c) contacting the product obtained in step (b) with a titanium halide compound having the general formula TiX.sub.4, wherein Ti is a titanium atom and X is a halide atom. The invention also relates to a solid catalyst component obtainable by said process. The invention further relates to a process for producing polyethylene and its copolymers in the presence of the solid catalyst component and a co-catalyst.

A process for preparing a procatalyst for polymerization of olefins, comprising contacting a magnesium-containing support with a halogen-containing titanium compound, a first internal electron donor represented by Formula A, a second internal electron donor represented by Formula B, and an activator; wherein the molar ratio of the first internal donor to the second internal donor is between 0.01 and 0.7;

##STR00001##

wherein in Formula A each R.sup.80 group is independently a substituted or unsubstituted aromatic group; and R.sup.81, R.sup.82, R.sup.83, R.sup.84, R.sup.85, R.sup.86 and R.sup.87 are each independently selected from a hydrogen or a hydrocarbyl group; wherein in Formula B R.sup.51 and R.sup.52 are each independently selected from a hydrogen or a hydrocarbyl group; and R.sup.53 and R.sup.54 are each independently selected from hydrogen, a halide or a hydrocarbyl group.

A process for preparing a procatalyst for polymerization of olefins, comprising contacting a magnesium-containing support with a halogen-containing titanium compound, a first internal electron donor represented by Formula A, a second internal electron donor represented by Formula B, and an activator; wherein the molar ratio of the first internal donor to the second internal donor is between 0.01 and 0.7;

##STR00001##

wherein in Formula A each R.sup.80 group is independently a substituted or unsubstituted aromatic group; and R.sup.81, R.sup.82, R.sup.83, R.sup.84, R.sup.85, R.sup.86 and R.sup.87 are each independently selected from a hydrogen or a hydrocarbyl group; wherein in Formula B R.sup.51 and R.sup.52 are each independently selected from a hydrogen or a hydrocarbyl group; and R.sup.53 and R.sup.54 are each independently selected from hydrogen, a halide or a hydrocarbyl group.

A catalyst component (A) for olefin polymerization is prepared by contacting a solid component (a) containing magnesium, titanium, halogen and an internal electron donor compound with an organosilicon compound (b), wherein the organosilicon compound (b) is one or more selected from a SiH functional group containing chainlike polysiloxane (b1) represented by formula (I.sub.x), a cyclic polysiloxane (b2) represented by formula (I.sub.y) and a SiH functional group containing organosilicon compound (b3) represented by formula (I.sub.z). In addition, a process for preparing the catalyst component and the corresponding catalyst is described. The catalyst component and its catalyst have high catalytic activity, good hydrogen response, and good stereospecificity, the catalyst can release its activity more evenly, and the obtained polymer has significantly increased bulk density. The definitions of R.sup.1 to R.sup.10, n and z in the formulae (I.sub.x), (l.sub.y) and (I.sub.z) are as described in the specification. ##STR00001##

The present invention relates to a process for preparing a catalyst component for polymerization of an olefin comprising the steps of: i) contacting a compound R.sup.9.sub.zMgX.sub.2-z wherein R.sup.9 is aromatic, aliphatic or cyclo-aliphatic group containing up to 20 carbon atoms, X is a halide, and z is in a range of larger than 0 and smaller than 2, with an alkoxy- or aryloxy-containing silane compound to given a first intermediate reaction product; ii) contacting the first intermediate reaction product with at least one activating compound selected from the group formed by electron donors and compounds of formula M(OR.sup.10).sub.v-w(OR.sup.11).sub.w, wherein M can be Ti, Zr, Hf, Al or Si, and M(OR.sup.10).sub.v-w(R.sup.11).sub.w, wherein M is Si, each R.sup.10 and R.sup.11, independently, represent an alkyl, alkenyl or aryl group, v is the valency of M, v being either 3 or 4, and w is smaller than v, to give a second intermediate reaction product; and iii) contacting the second intermediate reaction product with a halogen-containing Ti-compound, a monoester as activating agent, a 1,3-diether as an internal electron donor, and optionally a diester as an additional internal electron donor.

The present disclosure provides a heterogeneous Ziegler-Natta catalyst system to be used in the preparation of ultra-high molecular weight polymers (UHMWP). The system includes at least one procatalyst, at least one co-catalyst, at least one hydrocarbon medium and at least one external donor, wherein the ratio of elemental magnesium to elemental titanium to halide, in the procatalyst, is 1:1.3:3.7; the ratio of elemental aluminum, present in the co-catalyst to elemental titanium, present in the procatalyst, ranges between 6:1 and 12:1; and the ratio of elemental silicon, present in the external donor to elemental titanium, present in the procatalyst, ranges between 1:10 and 10:1. The present disclosure also provides a process for preparation of UHMWPE using the heterogeneous Ziegler-Natta catalyst system of the present disclosure.