The various embodiments of the invention provide, a magnesium titanium polymerization procatalyst, methods for making and using the same.

The invention relates to a process for the preparation of a multimodal copolymer of ethylene and a comonomer which is 1-hexene and/or 1-butene in a series of polymerization reactors comprising at least a first polymerization reactor and a second polymerization reactor, the process comprising: a) feeding ethylene, hydrogen and catalyst components (1) and a first diluent (29) to the first polymerization reactor (A) to prepare a first suspension (3) of solid particles of a first ethylene polymer in a first suspension medium, wherein the first diluent (29) comprises branched heptane and is essentially free of the comonomer: b) feeding the first suspension (3) to a flash drum (E) for vaporizing a part of the first suspension medium to obtain a hydrogen-depleted suspension (4), c) feeding the hydrogen-depleted suspension (4), ethylene and comonomer (9) and a second diluent (24 & 34) to the second polymerization reactor (H) to prepare a second suspension (11) of solid particles of a second ethylene polymer in a second suspension medium, wherein the second diluent (24 & 34) comprises branched heptane and the comonomer dissolved in the second diluent, d) processing the second suspension (11) to obtain a dry effluent (15) of the solid particles of the second ethylene polymer and a liquid stream (23) comprising branched heptane, the comonomer, and low molecular weight hydrocarbon reaction products, e) feeding at least part (25) of the liquid stream (23) to an evaporation system (Q) for separating non-volatile, low-molecular-weight hydrocarbon reaction products and subsequently to a distillation column (R) for separating the comonomer from branched heptane to obtain 1) a branched heptane liquid stream (29) essentially free of the comonomer. 2) a vapor distillate (31) comprising the comonomer and branched heptane and 3) a liquid distillate (30) comprising branched heptane and the comonomer, f) feeding the liquid distillate stream (30) to the second polymerization reactor (B) to form at least part of the second diluent (34) and g) feeding the branched heptane liquid stream (29) to the first polymerization reactor as the first diluent.

A process may include contacting ethylene monomer with Ziegler-Natta catalyst to form polyethylene. The Ziegler-Natta catalyst may be formed by contacting an alkyl magnesium compound with an alcohol and a metal reagent to form a blend, and contacting the blend with a first agent to form a solution of reaction product A. The solution of reaction product A may be contacted with a second agent to form a solid reaction product B, and the solid reaction product B may be contacted with a third agent to form a solid reaction product C. The solid reaction product C may be contacted with a fourth agent to form a solid reaction product D, and the solid reaction product D may be contacted with a fifth agent to form a catalyst component.

Methods for controlling the productivity of an olefin polymer in a polymerization reactor system using a halogenated hydrocarbon compound are disclosed. The productivity of the polymer can be increased via the addition of the halogenated hydrocarbon compound.

A method is provided to control the short chain branching (SCB) distribution of an ethylene-butene (EB) polyethylene resin that is prepared in a gas phase polymerization process using a specific type of magnesium-titanium Ziegler Natta catalyst. The method allows the level of short chain branching to be increased in the low molecular weight fraction of the resin by increasing the polymerization residence time. The polymers that are produced in accordance with this invention may be useful for the preparation of cast films and blown films, especially for stretch film applications.

A method is provided to control the short chain branching (SCB) distribution of an ethylene-butene (EB) polyethylene resin that is prepared in a gas phase polymerization process using a specific type of magnesium-titanium Ziegler Natta catalyst. The method allows the level of short chain branching to be increased in the low molecular weight fraction of the resin by increasing the polymerization residence time. The polymers that are produced in accordance with this invention may be useful for the preparation of cast films and blown films, especially for stretch film applications.

A solid catalyst component for the polymerization of olefins made from or containing Mg, Ti, halogen and an electron donor of formula (I) or (II): ##STR00001##
When activated with an aluminum alkyl and optionally an external electron donor, the solid catalyst component can give high activity and stereospecificity in the polymerization of olefins.

A solid catalyst component for the polymerization of olefins made from or containing Mg, Ti, halogen and an electron donor of formula (I) or (II): ##STR00001##
When activated with an aluminum alkyl and optionally an external electron donor, the solid catalyst component can give high activity and stereospecificity in the polymerization of olefins.

This disclosure relates to rotomolded articles, having a wall structure, where the wall structure contains at least one layer containing an ethylene interpolymer product, or a blend containing an ethylene interpolymer product and an ethylene polymer, where the ethylene interpolymer product has a Dilution Index (Y.sub.d) greater than 0 and improved Environmental Stress Crack Resistance (ESCR). The ethylene interpolymer product has a melt index from about 0.5 to about 15 dg/minute, a density from about 0.930 to about 0.955 g/cm.sup.3, a polydispersity (M.sub.w/M.sub.n) from about 2 to about 6 and a CDBI.sub.50 from about 50% to about 98%. Further, the ethylene interpolymer products are a blend of at least two ethylene interpolymers; where one ethylene interpolymer is produced with a single-site catalyst formulation and at least one ethylene interpolymer is produced with a heterogeneous catalyst formulation.

A solid catalyst component for the polymerization of olefins made from or containing Mg, Ti, halogen and an electron donor of formula (I) or (II) ##STR00001## When activated with an aluminum alkyl and optionally an external electron donor, solid catalyst component can give high activity and stereospecificity in the polymerization of olefins.