Abstract: The invention relates to a process for the preparation of a high activity procatalyst for the production of ethylene polymers. The process according to the present invention comprises the following steps:(a) contacting the inorganic support with an alkyl metal chloride which is soluble in non-polar hydrocarbon solvents, and has the formula(R.sub.n MeCl.sub.3-n).sub.m (1)wherein R is a C.sub.1 -C.sub.20 aklyl group, Me is a metal of group III(13) of the periodic table, n=1 or 2 and m=1 or 2, to give a first reaction product,(b) contacting said first reaction product with a compound or mixture containing hydrocarbyl and hydrocarbyl oxide linked to magnesium which is soluble in non-polar hydrocarbon solvents, to give a second reaction product, and(c) contacting said second reaction product with a titanium compound which contains chlorine, having the formulaCl.sub.x Ti(OR.sup.IV).sub.4-x (2)wherein R.sup.IV is a C.sub.2 -C.sub.20 hydrocarbyl group and x is 3 or 4, to give said procatalyst.

Abstract: The invention relates to a procatalyst for the production of ethylene polymers, which procatalyst comprises an inorganic support, a chlorine compound carried on said support, a magnesium compound carried on said support, a titanium compound carried on said support, whereby the chlorine compound can be different from or the same as the magnesium compound and/or the titanium compound. The activity balance AB of the procatalyst in specified polymerization conditions, isAB>3.2wherein AB=?(A+A'):2!.multidot.?log (MFR.sub.2 ':MFR.sub.2):(A-A')!, A means polymerization activity expressed an kg PE/g cat .multidot.h, MFR.sub.2 means the melt flow rate in g/min units at a load of 2,16 kg, according to the standard ISO 1133, the absence of the upper index ' means low melt flow rate polymerization and the presence of the upper index ' means high melt flow polymerization. This means that the catalyst activity is relatively independent of the presence of chain transfer agents.

Abstract: The invention relates to a process for the preparation of a solid procatalyst composition of a catalyst system for the polymerization of olefins wherein a magnesium halide such as magnesium chloride is dissolved and/or suspended into an alkyl ester of a monocarboxylic acid such as ethyl acetate, impregnated to a carrier, treated with an organometallic compound or a silicon compound and thereafter with a transition metal compound. The invention also relates to a procatalyst composition and its use together with a cocatalyst for the polymerization of olefins. The activity has been enhanced according to the invention by the use of a carrier containing hydroxyl groups, which carrier is kept at a temperature of at most about 200.degree. C. prior to the impregnation so that the hydroxyl groups are retained in the carrier to an essential extent until the impregnation step. The carrier is preferably silica which is treated thermally at 100.degree.-200.degree. C.

Abstract: The invention relates to a method for the preparation of a solid procatalyst composition for a catalyst system intended for the polymerization of olefins, wherein a magnesium halide, such as magnesium chloride, is dissolved and/or slurried in a mono-carboxylic acid alkyl ester, such as ethyl acetate, is impregnated into a support material, dried, treated with an organometallic compound or a silicon compound and thereafter with a transition metal compound. The invention also relates to such a procatalyst composition and its use together with a cocatalyst for the polymerization of olefins. According to the invention it has been possible to increase the activity of the catalyst composition by using a silanated support material, such as silanated silica, which is then treated with an organometallic or silicon compound before treatment with a transition metal compound. The silanated silica is preferably a silicon dioxide which has been heat-treated at 1000.degree.-200.degree.