Titanium impregnated silica-chromium catalysts

Claim 1

A polymerization process compsiring contacting at least one mono-1-olefin having 2 to 8 carbon atoms per molecule with a catalyst produced by: (a) forming a silica hydrogel containing a pore preserving agent selected from (1) organic silicon compounds having the structure R n SiA 4-n wherein n is an integer of 2 or 3, and wherein each R is a saturated or unsaturated hydrocarbon group wherein each R can be the same or different and wherein A is selected from the group consisting of hydroxy radicals, halides and alkoxy radicals in which the alkyl group therein contains from 1 to about 10 carbon atoms, (2) water soluble inorganic acids which are sufficiently ionized to produce a pH of 0 to 3.5, (3) organic acids having an acid strength equal to or greater than that of acetic acid, and (4) anionic, cationic or non-ionic surfactants; (b) drying said hydrogel by means of air oven drying, spray drying, tray drying, vacuum oven drying or drying under a heat lamp to form a xerogel; (c) anhydrously incorporating a titanium compound into said xerogel; (d) wherein chromium is introduced by either coprecipitating same with said silica hydrogel, by combining a water-soluble chromium compound with said hydrogel, or adding anhydrous solution of a chromium compound soluble in non-aqueous solvents to said xerogel; and (e) after said drying of (b) and after said chromium of (d) is introduced, activating the resulting dried, chromium-containing composition by means of an activation procedure which comprises treatment at an elevated temperature in an atmosphere containing oxygen.