Patent ID: 8039564
Filing Date: 2011-10-18
Classification: C08F

Abstract:
1. A method for preparing a catalyst precursor for an olefin polymerization catalyst, the catalyst precursor comprising an inorganic support material carrying a chromium salt, aluminium carboxylate and boric acid, the method comprising i) providing an inorganic support material, ii) depositing a chromium salt onto the inorganic support material from a first solution comprising a chromium salt in a solvent which is water, C iii) depositing an aluminium carboxylate and boric acid onto the inorganic support material from a second solution comprising an aluminium carboxylate and boric acid in a solvent which is water, C iv) removing solvent to form the catalyst precursor comprising chromium salt, aluminium carboxylate and boric acid, wherein the inorganic support material is a silica xerogel comprising at least 90% by weight of SiO