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.

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.

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.

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.

A process for the preparation of a procatalyst suitable for preparing a catalyst composition for olefin polymerization, the procatalyst obtained or obtainable by the process; and a catalyst composition for olefin polymerization comprising the procatalyst. In particular a benzamide can be used as an activator in the preparation of a supported Ziegler-Natta type procatalyst useful for a process for the preparation of polyolefins. The Polyolefins and polypropylene homopolymers are also disclosed.

A process for the preparation of a procatalyst suitable for preparing a catalyst composition for olefin polymerization, the procatalyst obtained or obtainable by the process; and a catalyst composition for olefin polymerization comprising the procatalyst. In particular a benzamide can be used as an activator in the preparation of a supported Ziegler-Natta type procatalyst useful for a process for the preparation of polyolefins. The Polyolefins and polypropylene homopolymers are also disclosed.

A solid catalyst component for the (co)polymerization of -olefins having general formula (I):
Zr.sub.nMAl.sub.xCl.sub.yMg.sub.p(I)
wherein: M represents titanium (Ti), vanadium (V), or mixtures thereof; n is a number ranging from 0.01 to 2; x is a number ranging from 0.1 to 4; y is a number ranging from 5 to 53; p is a number ranging from 0 to 15;
obtained by means of a process comprising putting at least one zirconium arene in contact with at least one metal compound and, optionally, with at least one compound of magnesium. Said solid catalyst component can be advantageously used as a solid component in a catalyst for the (co)polymerization of -olefins. Said catalyst can be advantageously used in a process for the (co)polymerization of -olefins.

A solid catalyst component for the (co)polymerization of -olefins having general formula (I):
Zr.sub.nMAl.sub.xCl.sub.yMg.sub.p(I)
wherein: M represents titanium (Ti), vanadium (V), or mixtures thereof; n is a number ranging from 0.01 to 2; x is a number ranging from 0.1 to 4; y is a number ranging from 5 to 53; p is a number ranging from 0 to 15;
obtained by means of a process comprising putting at least one zirconium arene in contact with at least one metal compound and, optionally, with at least one compound of magnesium. Said solid catalyst component can be advantageously used as a solid component in a catalyst for the (co)polymerization of -olefins. Said catalyst can be advantageously used in a process for the (co)polymerization of -olefins.

The invention relates to a process for transitioning from a first continuous polymerization reaction in a reactor, for example a gas-phase reactor conducted in the presence of a first catalyst to a second continuous polymerization reaction in the react or conducted in the presence of a second catalyst, wherein the first and second catalysts are incompatible, the process comprising: (a) discontinuing the introduction of the first catalyst from a catalyst feeding system into a reactor and emptying the catalyst feeding system of the first catalyst; (b) introducing a first catalyst killer to the reactor to substantially deactivate the first catalyst in the reactor; (c) introducing a second catalyst killer to the catalyst feeding system to substantially deactivate the first catalyst in the catalyst feeding system; (d) introducing a second catalyst to the catalyst feeding system and (e) introducing the second catalyst to the reactor from the catalyst feeding system, wherein the second catalyst killer is the same as or different from the first catalyst killer.

The invention relates to a process for transitioning from a first continuous polymerization reaction in a reactor, for example a gas-phase reactor conducted in the presence of a first catalyst to a second continuous polymerization reaction in the react or conducted in the presence of a second catalyst, wherein the first and second catalysts are incompatible, the process comprising: (a) discontinuing the introduction of the first catalyst from a catalyst feeding system into a reactor and emptying the catalyst feeding system of the first catalyst; (b) introducing a first catalyst killer to the reactor to substantially deactivate the first catalyst in the reactor; (c) introducing a second catalyst killer to the catalyst feeding system to substantially deactivate the first catalyst in the catalyst feeding system; (d) introducing a second catalyst to the catalyst feeding system and (e) introducing the second catalyst to the reactor from the catalyst feeding system, wherein the second catalyst killer is the same as or different from the first catalyst killer.