Stabilized activators and their use in emuslion polymerization

Claim 1

IN THE PRODUCTION OF SYNTHETIC RUBBER BY POLYMERIZATION OF A MONOMERIC MATERIAL COMPRISING 65 TO 90 PER CENT 1,3-BUTADIENE AND 35 TO 10 PER CENT STYRENE WHILE DISPERSED IN AQUEOUS EMULSION AT A POLYMERIZATION TEMPERATURE BELOW 0* C., THE IMPROVEMENT WHICH COMPRISES ADMIXING AT A POLYMERIZATION TEMPERATURE BELOW 0* C. SAID MONOMERIC MATERIAL, AN AQUEOUS MEDIUM IN A WEIGHT RATIO TO SAID MONOMERIC MATERIAL BETWEEN 1.5:1 AND 2.75:1, AN EMULSIFYING AGENT, A TERTIARY ALKYL MERCAPTAN HAVING 12 TO 16 CARBON ATOMS PER MOLECULE IN AN AMOUNT BETWEEN 0.05 AND 1.4 PARTS PER 100 PARTS OF SAID MONOMERIC MATERIAL, AND AN ACTIVATOR SOLUTION PREPARED BY DISSOLVING IN WATER FERROUS SULFATE, SODIUM PYROPHOSPHATE AND SUFFICIENT HYDROCHLORIC ACID TO PRODUCE A PH OF THE SOLUTION WITHIN THE RANGE OF 3 TO 8.5, WITH THE FIRST TWO IN EQUIMOLAR PROPORTIONS, HEATING THE RESULTING SOLUTION TO 40 TO 80* C. FOR 5 TO 90 MINUTES AND SUBSEQUENTLY COOLING SAID SOLUTION, WITH THE COMPOSITION OF SAID ACTIVATOR SOLUTION AND THE AMOUNT ADDED BEING SUCH THAT 0.01 TO 1.0 MILLIMOL PART OF FERROUS SULFATE AND SODIUM PYROPHOSPHATE ARE ADDED PER 100 PARTS BY WEIGHT OF SAID MONOMERIC MATERIAL, AND SUBSEQUENTLY ADDING TO SAID MIXTURE CUMENE HYDROPEROXIDE IN AN AMOUNT IN EXCESS OF ONE MOLECULAR EQUIVALENT OF SAID FERROUS SALT, MAINTAINING SAID MATERIALS ADMIXED AT A POLYMERIZATION TEMPERATURE BELOW 0* C. FOR A TIME SUFFICIENT TO EFFECT POLYMERIZATION OF 50 TO 85 PER CENT OF SAID MONOMERIC MATERIAL, AND RECOVERING FROM SAID REACTION MIXTURE POLYMERS SO PRODUCED.