What is disclosed is a method for preparing a catalyst system and a catalyst system for polymerizing or copolymerizing an α-olefin. Catalyst component (A) is obtained by a process of reacting a magnesium complex (A-1) containing acid salts of group IB-VIIIB elements formed by contacting a magnesium halide with an acid salt solution of group IB-VIIIB metals or spherical particles adducts, an internal electron donor (A-2) of diester or diether or composite compounds, and a titanium compound (A-3). The catalyst compound (A) is contacted with a silicon compound (B) and an organoaluminium compound (C) to complete the catalyst system providing a good balance of catalyst performance in terms of activity and stereo-specificity.

What is disclosed is a method for preparing a catalyst system and a catalyst system for polymerizing or copolymerizing an α-olefin. Catalyst component (A) is obtained by a process of reacting a magnesium complex (A-1) containing acid salts of group IB-VIIIB elements formed by contacting a magnesium halide with an acid salt solution of group IB-VIIIB metals or spherical particles adducts, an internal electron donor (A-2) of diester or diether or composite compounds, and a titanium compound (A-3). The catalyst compound (A) is contacted with a silicon compound (B) and an organoaluminium compound (C) to complete the catalyst system providing a good balance of catalyst performance in terms of activity and stereo-specificity.

What is disclosed is a method for preparing a catalyst system and a catalyst system for polymerizing or copolymerizing an -olefin. Catalyst component (A) is obtained by a process of reacting a magnesium complex (A-1) containing acid salts of group IB-VIIIB elements formed by contacting a magnesium halide with an acid salt solution of group IB-VIIIB metals or spherical particles adducts, an internal electron donor (A-2) of diester or diether or composite compounds, and a titanium compound (A-3). The catalyst compound (A) is contacted with a silicon compound (B) and an organoaluminium compound (C) to complete the catalyst system providing a good balance of catalyst performance in terms of activity and stereo-specificity.

What is disclosed is a method for preparing a catalyst system and a catalyst system for polymerizing or copolymerizing an -olefin. Catalyst component (A) is obtained by a process of reacting a magnesium complex (A-1) containing acid salts of group IB-VIIIB elements formed by contacting a magnesium halide with an acid salt solution of group IB-VIIIB metals or spherical particles adducts, an internal electron donor (A-2) of diester or diether or composite compounds, and a titanium compound (A-3). The catalyst compound (A) is contacted with a silicon compound (B) and an organoaluminium compound (C) to complete the catalyst system providing a good balance of catalyst performance in terms of activity and stereo-specificity.

A precatalyst for the polymerization of -olefins, having the formula Fe.sub.uM.sup.alc.sub.vX.sub.w(LA).sub.y(LB).sub.z wherein: M.sup.alc is an alkali metal and/or an alkaline-earth metal; X is an anion; LA is a Lewis acid; LB is a Lewis base; u is from 0.001 to 10; v is an integer 1; w is from 1 to 20; y is from 0 to 10; z is from 0 to 10.

A precatalyst for the polymerization of -olefins, having the formula Fe.sub.uM.sup.alc.sub.vX.sub.w(LA).sub.y(LB).sub.z wherein: M.sup.alc is an alkali metal and/or an alkaline-earth metal; X is an anion; LA is a Lewis acid; LB is a Lewis base; u is from 0.001 to 10; v is an integer 1; w is from 1 to 20; y is from 0 to 10; z is from 0 to 10.

What is disclosed is a method for preparing a catalyst system and a catalyst system for polymerizing or copolymerizing an -olefin. Catalyst component (A) is obtained by a process of reacting a magnesium complex (A-1) containing acid salts of group IB-VIIIB elements formed by contacting a magnesium halide with an acid salt solution of group IB-VIIIB metals or spherical particles adducts, an internal electron donor (A-2) of diester or diether or composite compounds, and a titanium compound (A-3). The catalyst compound (A) is contacted with a silicon compound (B) and an organoaluminium compound (C) to complete the catalyst system providing a good balance of catalyst performance in terms of activity and stereo-specificity.

What is disclosed is a method for preparing a catalyst system and a catalyst system for polymerizing or copolymerizing an -olefin. Catalyst component (A) is obtained by a process of reacting a magnesium complex (A-1) containing acid salts of group IB-VIIIB elements formed by contacting a magnesium halide with an acid salt solution of group IB-VIIIB metals or spherical particles adducts, an internal electron donor (A-2) of diester or diether or composite compounds, and a titanium compound (A-3). The catalyst compound (A) is contacted with a silicon compound (B) and an organoaluminium compound (C) to complete the catalyst system providing a good balance of catalyst performance in terms of activity and stereo-specificity.

A precatalyst for the polymerization of -olefins, having the formula Fe.sub.uM.sup.alc.sub.vX.sub.w(LA).sub.y(LB).sub.z wherein: M.sup.alc is an alkali metal and/or an alkaline-earth metal. X is an anion; LA is a Lewis acid; LB is a Lewis base; u is between 0.001 and 10; v is an integer 1; w is between 1 and 20; y is between 0 and 10;
z is between 0 and 10.

A precatalyst for the polymerization of -olefins, having the formula Fe.sub.uM.sup.alc.sub.vX.sub.w(LA).sub.y(LB).sub.z wherein: M.sup.alc is an alkali metal and/or an alkaline-earth metal. X is an anion; LA is a Lewis acid; LB is a Lewis base; u is between 0.001 and 10; v is an integer 1; w is between 1 and 20; y is between 0 and 10;
z is between 0 and 10.