Patent ID: 7666810

Claim:
A process to prepare an olefin polymerization procatalyst, said process comprising: Step a): forming a solid product by reacting: i) a diorganomagnesium compound defined by the formula MgRaRb, wherein each of Ra and Rb is independently selected from the group consisting of C 1 to C 8 hydrocarbyl groups, with ii) a source of active chlorine, wherein the mole ratio of chlorine in said active chlorine to said Mg is less than 2 and the mole ratio of chlorine in said active chlorine to the total moles of (Ra+Rb) is from 1.55 to 1.90/1; Step b): collecting said solid product from step a) and separating said solid product from said diorganomagnesium which did not react in said step a); washing said solid product; adding to said solid product a tetravalent titanium chloride species of the formula: TiCl n (OR) m , wherein n is from 2 to 4 and n+m=4 and wherein OR is a ligand selected from the group consisting of alkoxy, aryloxy and mixtures thereof.