Olefin polymerization catalysts

摘要

A TiCl3 olefin polymerization catalyst component is prepared by reducing TiCl4 with an aluminum trihydrocarbyl compound in a molar ratio of Ti:Al of 2.7:1 to 4.0:1 in the presence of diisoamyl ether and a hydrocarbon solvent by gradually adding TiCl4 to the aluminum trihydrocarbyl compound and at least a substantial proportion of the diisoamyl ether at a temperature of from 15 DEG to 50 DEG C. during a period of from 0.7 to 2.5 hours to produce a precipitate of TiCl3, and thereafter converting the precipitate into active TiCl3 by heating at a temperature of from 80 DEG to 110 DEG C. during at least 30 minutes. The active TiCl3, when combined with a conventional organoaluminum cocatalyst, provides a stereospecific catalyst for the polymerization of alpha monoolefins having high activity, good morphology and good stereospecificity.