| 摘要 |
A process for the stereospecific polymerization of alpha -olefins which comprises polymerizing an alpha -olefin with a catalyst comprising (A) the reaction product of a magnesium compound and a titanium compound and (B) an organo-aluminum compound. Component (A) is prepared by reacting a (i) magnesium compound of the formula Mg(OR1)nX12-n wherein R1 contains from 1 to 10 carbon atoms and is an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group, X1 is a halogen atom, and n is a real number of from 1.0 to 2.0, with (ii) at least one halogen-containing compound selected from the group consisting of halogenated hydrocarbons, oxygen-containing halogenated hydrocarbons, halogenated thionyls, halogen-containing phosphorus compounds and halogen-containing nitrogen compounds, and (iii) an oxygen-containing titanium compound of the formula Ti(OR2)4 wherein R2 contains from 1 to 10 carbon atoms and is an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group, (iv) in the presence or in the absence of an organic acid ester to produce a solid reaction product. Said solid reaction product is, as it is or after a pre-treatment with an organic acid ester, reacted with a halogen-containing tetravalent titanium compound of the formula Ti(OR3)mX24-m wherein R3 contains from 1 to 10 carbon atoms and is an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group, X2 is a halogen atom, and m is a real number of from 0 to 3.0, in the presence or in the absence of an organic acid ester, and always in the presence of an organic acid ester when an organic acid ester was not used in at least one of the preceding steps. |
