Polymerization process with a catalyst system of metal halide and organo-magnesium compound

Claim 1

A PROCESS FOR PREPARING A POLYMER FROM AT LEAST ONE MONOMER FROM THE CLASS CONSISTING OF ACRYLONITRILE, METHACRYLONITRILE, AND ESTERS OF ACRYLIC ACID AND OF METHACRYLIC ACID AND AN ALCOHOL, THE NON-HYDROXYL PORTION OF WHICH IS FREE OF GROUPS HAVING REACTIVE HYDROGEN AS DETERMINED BY THE ZEREWITINOFF TEST, WHICH COMPRISES FIRST MIXING TOGETHER UNDER SUBSTANTIALLY ANHYDROUS CONDITIONS AND BEFORE ORGANO-MAGNESIUM COMPOUND IS INTRODUCED A SAID MONOMER AND A MEMBER OF THE CLASS CONSISTING OF BORON TRIFLUORIDE, BERYLLIUM CHLORIDE, BERYLLIUM BROMIDE, BERYLLIUM IODIDE, MAGNESIUM CHLORIDE, MAGNESIUM BROMIDE, MAGNESIUM IODIDE, CALCIUM CHLORIDE, CALCIUM BROMIDE, CALCIUM IODIDE, STRONTIUM CHLORIDE, STRONTIUM BROMIDE, STRONTIUM IODIDE, BARIUM CHLORIDE, BARIUM BROMIDE, BARIUM IODIDE, ZINC CHLORIDE, ZINC BROMIDE, ZINC IODIDE, CADMIUM CHLORIDE, CADMIUM BROMIDE, CADMIUM IODIDE, ALUMINUM CHLORIDE, ALUMINUM BROMIDE, AND ALUMINUM IODIDE, THE SAID MEMBER BEING MIXED IN A PROPORTION OF 0.5 TO 2.0 MOLES THEREOF PER MOLE OF SAID MONOMER, WHEREBY A PERFORMED COMPLEX IS FORMED FROM SAID MEMBER IN SAID MONOMER, AND THEN BRINGING TOGETHER UNDER SUBSTANTIALLY ANHYDROUS AND ANAEROBIC CONDITIONS AT A TEMPERATURE FROM -90*C. TO 50*C. AND IN ADMIXTURE WITH AN ORGANIC SOLVENT INERT TO ORGANO-MAGNESIUM COMPOUNDS THE MONOMER CONTAINING SAID PREFORMED COMPLEX AND 0.001 TO 0.1 MOLE OF AN ORGANO-MAGNESIUM COMPOUND PER MOLE OF SAID MONOMER, SAID ORGANO-MAGNESIUM COMPOUND BEING OF THE FORMULA