Patent ID: 6472550
Filing Date: 2002-10-29
Classification: C08K

Abstract:
A process for the preparation of a stabiliser mixture containing a low amount of chloride comprisinga) 50-80% by weight of a diphosphonite of the formula I b) 5-25% by weight of a monophosphonite of the formula II c) 5-25% by weight of a phosphite of the formula III in which R is a radical of the formula IV and where the sum of the compounds of the formula I, II and III is not greater than 100% by weight, by reacting a biphenyl of the formula V under Friedel-Crafts condition with phosphorus trichloride and aluminium trichloride and by reacting the product mixture with 2,4-di-tert-butyl-phenol of the formula VI in the presence of a tertiary amine or an aromatic amine and a solvent, separating the formed two layers, which process comprises treating the solvent layer with water, a base and a desiccant, separating the precipitate from the solution containing the stabiliser mixture and evaporating the solvent.