Patent ID: 8298978
Filing Date: 2012-10-30
Classification: C08F

Abstract:
1. A method of making a catalyst system having an activity greater than 1500 g of polymer per gram of supported catalyst per hour normalized to 1379 kPag (200 psig) of ethylene partial pressure and a temperature of 90° C. and a kinetic profile for a plot of ethylene consumption in standard liters of ethylene per minute against time in minutes, at a reaction pressure of 1379 kPag (200 psig) and 90° C., corrected for the volume of ethylene in the reactor prior to the commencement of the reaction, in a 2 liter reactor over a period of time from 0 to 60 minutes is such that the ratio of the maximum peak height over the first 10 minutes to the average ethylene consumption from 10 to 60 minutes taken at not less than 40 data points, is less than 3.5, comprising: i) impregnating a porous particulate inorganic oxide support having an average particle size from 10 to 150 microns, a surface area greater than 100 m (ii) at least a 1 weight % aqueous solution of a metal salt selected from the group consisting of Zr(SO (iii) recovering the impregnated support; (iv) calcining said impregnated support in one or more steps at a temperature from 300° C. to 630° C. for a time from 2 to 20 hours in an inert atmosphere; (v) and either (vi) recovering and drying the catalyst.