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 0.05 to 10 mols of (B) to one mol of (A), and
• reacting them together at a temperature of room temperature (20.degree. C.) to 500.degree. C.,
• to obtain a solid product (I);
• reacting with 100 g of this solid product (I),
• (C) 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
• (D) an electron acceptor selected from the group consisting of (D-1) aluminum chloride compounds expressed by the formula R.sub.n AlCl.sub.3-n (wherein O.ltoreq.n<3 and R is a hydrocarbon radical of 1 to 20 carbon atoms), (D-2) inorganic chlorides of an atom selected from the group consisting of Si, Sn, Ti, Zr, P, V, Sb, S, Mn, Fe and Ni, and (D-3) organomagnesium compounds expressed by the formula (MgR.sub.2)a.(R'MgX).sub.b (wherein R and R' are each an alkyl group of 1 to 20 carbon atoms or a phenyl group substituted or unsubstituted by an alkyl group of 1 to 10 carbon atoms;
• X is Cl, Br or I;
• and a and b are each a number of 0 to 1, and a+b=1),
• at a reaction temperature of 0.degree. to 500.degree. C.,
• (C) and (D) being respectively reacted once or twice or more up to 10 times,
• TiCl.sub.4 being employed as said electron acceptor at least once, and
• (C) and (D) being respectively employed in an amount of 5 to 50 g a time,
• to obtain a solid product (II),
• (this reaction being referred to as formation reaction of solid product (II));
• combining with 1 g of this solid product (II),
• (E) 0.5 to 500 g of a trialkylaluminum, and
• (G) 1 to 20 g of a reaction product of an electron donor with an electron acceptor, both being selected from among the substances listed above in the respective groups of (C) and (D),
• (said solid product (II), (E) and (G) employed for this combination being referred to catalyst components), and
• at the time of this combination, subjecting a part or the whole of the catalyst components to polymerization treatment by reacting (F) an .alpha.-olefin at a temperature of 0.degree. to 100.degree. C. in an amount of 0.1 to 500 g, at least in the presence of said solid product (II) and trialkylaluminum,
• to obtain a preliminarily activated catalyst;
• and
• polymerizing an .alpha.-olefin or .alpha.-olefins in the presence of this catalyst.