Abstract: A solid hydrocarbon-insoluble, alpha-olefin polymerization catalyst component with superior activity, stereospecificity and morphology characteristics comprising the product formed by A) forming a solution of a magnesium-containing species from a magnesium alkyl (or hydrocarbyl) carbonate or a magnesium carboxylate; B) precipitating solid particles from such solution by treatment with a transition metal halide; C) reprecipitating such solid particles from a mixture containing a cyclic ether; D) treating the reprecipitated particles with a transition metal compound and an electron donor; and E) drying the resulting solid particles such that the residual volatile hydrocarbon content is between 0.1 and 0.9 weight percent.

Abstract: An olefin polymerization catalyst component comprises an organoaluminum-reduced titanium trihalide on which a pretreatment amount of olefin polymer has been placed complexed with an alkyl aliphatic carboxylic acid ester containing 7 to 22 carbon atoms having a structure:R--CO.sub.2 R'wherein R' is an alkyl group containing 3 to about 8 carbon atoms and R is an alkyl group containing 3 to 17 carbon atoms, and treated with a Lewis acid, a chlorocarbon or an haloalkylchlorosilane.

Abstract: A solid-hydrocarbon insoluble, alpha-olefin polymerization catalyst component with superior activity, stereospecificity and morphology characteristics, comprises the product formed by (a) complexing a magnesium alkyl composition with an ortho disubstituted hindered aromatic acid ester; (b) reacting the resulting complex with a compatible precipitation agent to form a solid component; and (c) reacting the resulting solid with a titanium(IV) compound and an electron donor compound in a suitable diluent.