Process for the preparation of an olefin polymerization catalyst

An improved process for the preparation of a supported chromium oxide type of catalyst for the polymerization of olefins wherein the reaction product of a chromium- 1,3-diketo compound and an organometallic compound of an element from Group II or III of the periodic system is deposited on an inert inorganic supporting material which is thereafter heated in a nonreducing atmosphere at a temperature of between 200.degree. and 1200.degree. C., the improvement comprising:

• reacting, in the presence of a solvent which is inert with respect to compounds (1), (2), and (3) hereinafter referenced,
• (1) a chromium chelate of a 1,3-diketo compound, and
• (2) a vanadium chelate or a vanadyl chelate of a 1,3-diketo compound,
• separately or jointly with
• (3) an organo-metallic compound of an element from Group II or III of the periodic system in which hydrocarbyl groups with 1-20 carbon atoms are bound, via a carbon atom, to the element;
• jointly contacting the resulting solution containing the reaction products of (1) and (2), with (3) with, and depositing said reaction products on, an inert inorganic supporting material;
• and
• heating said supporting material having said reaction products deposited thereon in a non-reducing atmosphere at a temperature of between about 200.degree. and 1200.degree. C.;
• wherein said 1,3-diketo compounds of (1) and (2) are the same or different and have the formula ##STR4## in which formula R.sub.1, R.sub.2, and R.sub.3 are the same or different, R.sub.1 and R.sub.3 being an alkyl group with 1-10 carbon atoms, and R.sub.2 being selected from the group consisting of an alkyl group with 1-10 carbon atoms, and a hydrogen atom.