Process for producing α-olefin polymers

Claim 1

A process for producing alpha-olefin polymers which comprises homopolymerizing or copolymerizing alpha-olefins in the presence of a catalyst system comprising: (A) a solid catalyst component containing a trivalent titanium compound, which is obtained by reducing a titanium compound represented by the general formula Ti(OR 1 ) n X 4-n (wherein R 1 is a hydrocarbon group having 1 to 20 carbon atoms, X is a halogen atom, and n is a number satisfying 0<n≦4) with an organo magnesium compound in the presence of an organo silicon compound having Si--O bonds of the formula: Si(OR.sup.3).sub.m R.sup.4.sub.4-m', R.sup.5 (R.sup.6 SiO).sub.p SiR.sup.7.sub.3 or (R.sup.8 SiO).sub.q (wherein R 3 is a hydrocarbon group having 1 to 20 carbon atoms, R 4 , R 5 , R 6 , R 7 and R 8 are each a hydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom, mm is a number satisfying 0<m≦4, p is an integer of 1 to 1,000, and q is an integer of 2 to 1,000); and then treating the resulting solid product with a mono- or poly-carboxylic acid ester compound and a mixture of a dialkyl ether compound and titanium tetrachloride; (B) an organo aluminum compound; and (C) an organo silicon compound having Si--OR 2 bonds which is an alkoxysilane compound represented by the general formula R 17 αSi(OR 2 ) 4- α (wherein R 2 and R 17 are each a hydrocarbon group having 1 to 20 carbon atoms and α is a number satisfying 0≦α≦3) and/or an organic carboxylic acid ester, at a temperature of -30° C. to 200° C. under a pressure of 3 to 100 atm.