Process for polymerizing styrene

Claim 1

A MASS POLYMERIZATION PROCESS WHICH COMPRISES (1) FORMING A REACTION MIXTURE BY DISSOLVING IN 100 PARTS BY WEIGHT OF STYRENE A MONOMER-SOLUBLE MIXTURE OF (A) 0.001-0.5 PART BY WEIGHT OF AN ORGANIC HYHDROPEROXIDE HAVING A HALF-LIFE OF AT LEAT 10 HOURS IN BENZENE AT 100*C., (B) 0.01-0.1 PARTS BY WEIGHT OF A PEROXY COMPOUND HAVING A HALF-LIFE OF AT LEAST 10 HOURS INBENZENE AT 100*C. AND CORRESPONDING TO THE FORMULA ROOR'', WHEREIN BOTH R AND R'' REPRESENT ORGANIC RADICALS, AND (C) AT LEAST 0.05 PART BY WEIGHT OF A MONOCARBOXYHYDROCARBON OF THE GROUP CONSISTING OF ACETIC ACID, HEXANOIC ACID, BENZOIC ACID, PHENYLACETIC ACID, ISOPROPYLBENZOIC ACID, HEXAHYDROENZOIC ACID, AND AN ALKANOIC ACID CONTAINING 12-20 CARBON ATOMS (2) HEATING THE REACTION MIXTURE AT 75-125*C. UNTIL 15-45% CONVERSION TO POLYMRE IS OBTAINED, THE TEMPERATURE BEING SO REGUALTED AS TO BE IN THE 75-95*C. RANGE AT THE TIME THAT THIS CONVERSION IS OBTAINED, (3) GRANUALLY RAISING THE REACTION TEMPERATURE TO 180-200*C. OVER A PERIOD OF ABOUT 3-7 HOURS, AND (4) MAINTAINING THE REACTION TEMPERATURE AT 180-200*C. FOR ABOUT 0.5-5 HOURS.