Process for producing .alpha.-olefin polymers

A process for producing .alpha.-olefin polymers which comprises:

• milling (A) a trivalent metal halide selected from the group consisting of aluminum trichloride (anhydrous), ferric chloride (anhydrous) and aluminum tribromide (anhydrous), together with
• (B) a divalent metal compound selected from the group consisting of
• Mg(OH).sub.2, Ca(OH).sub.2, Zn(OH).sub.2, Mn(OH).sub.2, MgO, CaO, ZnO, MnO, MgAl.sub.2 O.sub.4, Mg.sub.2 SiO.sub.4, Mg.sub.6 MnO.sub.8, MgCO.sub.3, MnCO.sub.3, MgCO.sub.3.CaCO.sub.3, SnCl.sub.2.2H.sub.2 O, MgCl.sub.2.nH.sub.2 O (n=1.about.6), NiCl.sub.2.6H.sub.2 O, MnCl.sub.2.4H.sub.2 O, KMgCl.sub.3.6H.sub.2 O, MgCl.sub.2.nMg(OH).sub.2.mH.sub.2 O (n=1.about.3, m=1.about.6), 3MgO.2SiO.sub.2.2H.sub.2 O, 3MgCO.sub.3.Mg(OH).sub.2.3H.sub.2 O and Mg.sub.6 Al.sub.2 (OH).sub.14 CO.sub.3.4H.sub.2 O,
• in a proportion of 0.1 to 20 mols of (B) to one mol of (A), and
• reacting the resulting mixture of (A) with (B) at a temperature of room temperature (20.degree. C.) to 500.degree. C.,
• to obtain a solid product (I);
• reacting with this solid product (I),
• (ED) an electron donor selected from the group consisting of alcohols, ethers, esters, aldehydes, fatty acids, ketones, nitriles, amines, amides, urea, thiourea, isocyanates, azo compounds, phosphines, phosphites, phosphinites, thioethers, thioalcohols and polysiloxanes, and
• (EA) an electron acceptor selected from the group consisting of (EA.sub.1) aluminum chloride compounds expressed by the formula R.sub.n AlCl.sub.3-n (wherein 0.ltoreq.n<3 and R is a hydrocarbon radical of 1 to 20 carbon atoms), and (EA.sub.2) inorganic chlorides consisting of the group of SiCl.sub.4, SnCl.sub.2, SnCl.sub.4, TiCl.sub.4, ZrCl.sub.4, PCl.sub.3, VCl.sub.4, SbCl.sub.5, SCl.sub.2, MnCl.sub.2, FeCl.sub.2 and NiCl.sub.2,
• at a reaction temperature of 0.degree. to 500.degree. C.,
• (ED) and (EA) being respectively reacted one to 10 times,
• TiCl.sub.4 being employed as said electron acceptor at least once, and
• (ED) and (EA) being respectively employed in an amount of 5 to 50 parts by weight each time, based on 100 parts by weight of said solid product (I),
• to obtain a solid product (II);
• combining with one part by weight of this solid product (II),
• 0. 1 to 500 parts by weight of (OAl) an organoaluminum compound, and
• 0. 05 to 20 parts by weight of (ED) an electron donor, and
• at the time of this combination, reacting 0.05 to 300 parts by weight based on one part by weight of said solid product (II), of (.alpha.-O) an .alpha.-olefin, with a combination of said solid product (II) and said (OAl) or a combination of said solid product (II), said (OAl) and said (ED), at a temperature of 0.degree. to 100.degree. C. for a period of one minute to 20 hours,
• to obtain a preactivated catalyst;
• and
• polymerizing an .alpha.-olefin or .alpha.-olefins in the presence of this catalyst.