Process for preparing a pillared phyllosilicate clay

摘要

A process for preparing pillared chromium phyllosilicate clay alpha -olefin catalysts is disclosed This process utilizes palygorskite and sepiolite clays. The pillaring of said clays comprise the steps of: (a) preparing a hydrolyzed first solution by dissolving a chromium salt and a base in water, heating said first solution to a temperature in the range of about 20 DEG C to about 100 DEG C while stirring continuously until the solution reaches a pH in the range of about 1.5 to about 2.5 and thereby producing a master batch; (b) diluting said master batch with water to produce a diluted second solution and heating said diluted second solution to produce a heated second solution; (c) adding a solid clay selected from the group consisting of sepiolites and palagorskites to said heated second solution, and continuing heating; (d) recovering said pillared chain silicate clay; (e) drying said pillared chain silicate clay to form first product; The activation of said clays comprise the steps of: (a) heating said first product at a temperature in the range of about 150 DEG C to about 500 DEG C and for a time period in the range of about 30 minutes to about 10 hours in an inert atmosphere; (b) thereafter reheating said first product at a temperature in the range of about 500 DEG C to about 900 DEG C and for a time period in the range of about 1 hour to about 50 hours in an oxidizing atmosphere and recovering said catalyst composition. This results in clay catalysts which polymerize alpha -olefins.