Polymerization method

Claim 1

A CONTINUOUS METHOD FOR THE POLYMERIZATION OF VINYLIDENE COMPOUNDS WHICH COMPRISES FEEDING AT LEAST ONE POLYMERIZABLE LIQUID VINYLIDENE COMPOUND, INCLUDING A POLYMERIZABLE AR-MONOALKENYL AROMATIC COMPOUND HAVING FROM 2 TO 3 CARBON ATOMS IN THE ALKENYL RADICAL THEREOF, AS A STREAM INTO ADMIXTURE WITH A PORTION OF A HEATED POLYMERIZATION MIXTURE THAT COMPRISES THE SAME TOGETHER WITH A POLYMER THEREOF AND THAT IS BEING WITHDRAWN AS A STREAM FROM A POLYMERIZATION ZONE FOR SUCH DILUTION WITH THE FEED MATERIAL, PASSING THE RESULTING MIXTURE THROUGH A HEAT EXCHANGER WHICH IS OPERATED TO BRING THE MIXTURE TO A TEMPERATURE SUCH THAT, UPON SUBSEQUENT PASSAGE INTO THE POLYMERIZATION ZONE, IT BRINGS THE MIXTURE THEREIN TO THE DESIRED POLYMERIZATION TEMPERATURE, WHICH IS ABOVE ROOM TEMPERATURE, THEN PASSING SAID RESULTING MIXTURE INTO THE POLYMERIZATION ZONE AND INTIMATELY ADMIXING IT WITH A LARGE PROPORTION BY WEIGHT OF A POLYMERIZATION MIXTURE, WHICH IS IN SAID ZONE AND WHICH COMPRISES THE SAME KINDS OF INGREDIENTS AS SAID RESULTING MIXTURE WHICH IS PASSED INTO SAID ZONE, WITHDRAWING A PORTION OF THE POLYMERIZATION MIXTURE AS A STREAM FROM THE POLYMERIZATION ZONE AND DISTILLING VOLATILE MATERIAL THEREFROM TO OBTAIN A RESIDUE OF THE POLYMERIC PRODUCT, AND RETURNING THE DISTILLATE TO THE POLYMERIZATION ZONE, AND, WHILE CONTINUING THE OPERATIONS JUST STATED, MAINTAINING THE MIXTURE IN THE POLYMERIZATION ZONE UNDER A NEARLY CONSTANT SET OF POLYMERIZATION CONDITIONS BY VARYING THE RATE OF FEED OF THE STARTING MATERIAL TO THE POLYMERIZATION SYSTEM AND CORRESPONDINGLY THE RATE OF WITHDRAWAL OF POLYMERIC PRODUCT FROM THE SYSTEM IN RESPONSE TO CHANGES IN THE CONCENTRATION OF POLYMER IN THE MIXTURE IN THE POLYMERIZATION ZONE IN A MANNER SUCH THAT SAID RATES ARE INCREASED WITH INCREASE IN SAID CONCENTRATION OF POLYMER ABOVE A GIVE VALUE AND ARE DECREASED WITH DECREASE IN THE CONCENTRATION OF POLYMER BELOW THE GIVEN VALUE AND THE POLYMER-CONCENTRATION OF THE MIXTURE IN THE POLYMERIZATION ZONE IS THEREBY PREVENTED FROM CHANGING TO MORE THAN A SLIGHT EXTENT FROM THE GIVEN VALUE, AND AT THE SAME TIME VARYING THE RATE OF CIRCULATION OF PART OF THE POLYMERIZATION MIXTURE THROUGH THE HEAT-EXCHANGER IN RESPONSE TO CHANGES IN THE TEMPERATURE OF THE MIXTURE IN THE POLYMERIZATION ZONE IN A MANNER SUCH THAT THE RATE OF CIRCULATION IS INCREASED WITH INCREASE IN THE TEMPERATURE ABOVE A GIVEN VALUE AND IS DECREASED WITH DECREASE IN THE TEMPERATURE BELOW THE GIVEN VALUE AND THE TEMPERATURE OF THE MIXTURE IN THE POLYMERIZATION ZONE, AT A POINT REMOTE FROM ANY POINT OF FEED OF POLYMERIZABLE MATERIAL TO THE POLYMERIZATION ZONE, IS THEREBY PREVENTED FROM CHANGING BY MORE THAN ABOUT 1*C. FROM THE GIVEN VALUE.