Patent ID: 6083866
Filing Date: 2000-07-04
Classification: C08F,Y02P

Abstract:
A catalytic system for the polymerisation of an .alpha.-olefin, consisting of:(1) a solid based on complexed titanium trichloride of .delta. crystalline form, free of magnesium, obtained by reducing titanium tetrachloride or tetraalkoxide with an organoaluminium reducing agent to form a resulting solid, treating said resulting solid with an aliphatic ether electron-donating compound and, either successively or simultaneously, treating said resulting solid with titanium tetrachloride and activating said successively or simultaneously treated resulting solid by bringing it into contact with an activation agent selected from the group consisting of organoaluminium compound and products from the reaction of an organoaluminium compound with a compound chosen from hydroxyaromatic compounds in which the hydroxyl group is sterically blocked,(2) an organoaluminium compound selected from the non-halogenated organoaluminium compounds of formulaAlR.sub.m Y.sub.3-mwhere R represents a hydrocarbon radical, containing from 1 to 18 carbon atoms, Y represents a group selected from the group consisting of --OR.sup.1, --SR.sup.1 and --NR.sup.1 R.sup.2 in which R.sup.1 and R.sup.2 each represent an identical or different hydrocarbon radical selected from the group consisting of alkyl, aryl, arylalkyl, alkylaryl and cycloalkyl radicals, and m is a number such that 0<m.ltoreq.3, and(3) diisobutyldimethoxysilane.