Polymerization of olefins in the presence of a catalyst modified with an organic anhydride

Claim 1

IN A PROCESS FOR POLYMERIZING AT LEAST ONE 1-OLFEIN TO SOLID POLYMER IN THE PRESENCE OF A CATALYST WHICH FORMS ON MIXING (A) A MATERIAL SELECTED FROM THE GOUP CONSISTING OF THE METALS, THE HYDRIDES, AND THE TETAALKYL AND TETRAARYL COMPOUNDS HAVING UP TO 40 CARBON ATOMS PER MOLECULE OF GE,SN,PB, (B) A HALIDE OF A METAL SELECTED FROM THE GROUP CONSISTING OF IV-B, V-B, AND VI-B METALS WHEREIN ALL VALENCES OF THE METAL ARE SATISFIED BY HALIDE, AND (C) A HALIDE OF A METAL SELECTED FROM THE GROUP CONSISTING OF B. AL, GA, IN, TL, SB, AND BI WHEREIN ALL THE VALENCES OF THE METAL ARE SATISFIED BY HALIDE; THE IMPROVEMENT WHICH COMPRISES SUPPLYING TO THE POLYMERIZATION MIXTURE A MINOR AMOUNT OF A CARBOXYLIC ACID ANHYDRIDE HAVING UP TO 20 CABON ATOMS PR MOLECULE SELECTED FROM THE GROUP CARBOXLIC ALIPHATIC ACID ANHYDRIDES, AROMATIC ACID ANHYDRIDES, AND CYCLIC ANHYDRIDES OF DICARBOXYLIC ACIDS AND THUS MODIFYING THE MOLECULAR WEIGHT OF THE RESULTING POLYMER.