Ethylene polymerization utilizing two organic peroxygen compounds as catalysts

Claim 1

IN THE PREPARATION OF POLYMERS OF ETHYLENE BY A CONTINUOUS NON-SOLVENT PROCESS, THE IMPROVEMENT WHICH COMPRISES CONTINUOUSLY FLOWING THROUGH A SMALL DIAMETER, HIGHLY ELONGATED TUBE A REACTION MIXTURE COMPRISING ETHYLENE, A CHAIN TRANSFER AGENT SELECTED FROM THE GROUP CONSISTING OF SATURATED LOWER HYDROCARBONS HAVING AT LEAST 3 CARBON ATOMS AND ACETONE, THE SAID CHAIN TANSFER AGENT BEING EMPLOYED IN AN AMOUNT FROM ABOUT 0.3 TO 15 MOLE PERCENT BASED ON ETHYLENE AND IN THE ABSENCE O ANY MORE THAN 2% BY WEIGHT BASED ON ETHYLENE OF OTHER SOLVENT AND A COMBINATION FREE RADICAL CATALYST COMPRISING MIXTURES OF CATALYST OF DECOMPOSITION TEMPERATURES DIFFERING BY AT LEAST 20 CENTIGRADE DEGREES AND IN THE RANGE FROM 110*C. TO 200*C., THE CATALYST BEING SELECTED FROM THE GROUP CONSISTING OF ORGANIC PEROXYGEN COMPOUNDS AND OXYGEN AND COMPRISING LAUROYL PEROXIDE AND DITERTIARYBUTYL PEROXIDE, AND MAINTAINING THE PRESSURE IN THE REACTION TUBE IN EXCESS OF ABOUT 15,000 POUNDS PER SQUARE INCH AND CARRYING OUT THE ACTUAL POLYMERIZATION IN THE RANGE OF 120* TO 300*C. AND OVER A BROADER TEMPERATURE RANGE THAN WOULD OBTAIN WITH USE OF A SINGLE CATALYST, UTILIZING INDIRECT HEAT EXCHANGE FOR CONTROL OF SAME, AND ADJUSTING THE AMOUNTS AND RATIO OF CATAYLST IN LINE WITH OTHER VARIABLES IN THE POLYMERIZATION TO OBTAIN GOOD POLYMER QUALITY ALONG WITH HIGH CONVERSION OF ETHYLENE TO THE POLYMER, THE CATALYST BEING PRESENT IN AMOUNTS SUCH THAT EACH CONSTITUTES AT LEAST 10 MOLAR PERCENT OF THE CATALYST COMBINATION ON A MOLAR BASIS AND THE TOTAL CATALYST IS 17 TO 35 MICROMOLS/MOLE OF ETHYLENE, AND BEING SELECTED SO AS TO OBTAIN A SUBSTANTIALLY LARGE PORTION OF THE POLYMERIZATION AT TEMPERATURE IN THE RANGE OF 120 TO 170*C., AND ALSO A SUBSTANTIALLY LARGE PORTION OF THE POLYMERIZATION AT TEMPERATURES WELL ABOVE 170*C., WHILE MAINTAINING A RELATIVELY SMOOTH REACTION AS INDICATED BY THE TEMPERATURE-TIME CURVE FOR THE REACTION BEING FAIRLY SMOOTH WITHOUT A PEAK RADICALLY HIGHER THAN THE REST OF THE CURVE.