Continuous process for producing block copolymers of dienes and vinyl aromatic compounds

Claim 1

A CONTINUOUS PROCESS FOR PREPARING A BLOCK COPOLYMER OF A CONJUGATED DIENE AND A VINYL-SUBSTITUTED AROMATIC HYDROCARBON, WHICH PROCESS COMPRISES, IN COMBINATION, THE STEPS OF: CONTINUOUSLY CHARGING TO A PREREACTION ZONE THE FOLLOWING MATERIALS (1) A FIRST MONOMER SELECTED FROM THE GROUP CONSISTING OF 1,3-BUTADIENE, ISOPRENE, AND PIPERLYLENE, AND THE MONOVINYL-SUBSTITUTED AROMATIC HYDROCARBONS, (2) AN ORGANOLITHIUM POLYMERIZATION INITIATOR, (3) A FIRST STREAM OF A HYDROCARBON DILUENT SELECTED FROM THE GROUP CONSISTING OF PARAFFINIC, CYCLOPARAFFINIC, AND AROMATIC HYDROCARBONS, SAID MATERIALS (1), (2), AND (3) BEING INTRODUCED AT RELATIVELY COLD TEMPERATURE, AND (4) A SECOND STREAM OF SAID HYDROCARBON DILUENT AT A RELATIVELY HOT TEMPERATURE GREATER THAN THE TEMPERATURE OF SAID MATERIALS (1), (2) AND (3), MAINTAINING THE CONTENTS OF SAID PREREACTION ZONE UNDER TURBULENT MIXING CONDITIONS AND UNDER SUFFICIENT PRESSURE TO MAINTAIN SAID CONTENTS SUBSTANTIALLY COMPLETELY IN THE LIQUID PHASE, AND MAINTAINING THE TEMPERATURE IN SAID PREREACTION ZONE WITHIN THE RANGE OF FROM 220 TO 350*F. WHEN SAID FIRST MONOMER IS ONE OF SAID DIENE COMPOUNDS AND WITHIN THE RANGE OF FROM 180 TO 250*F. WHEN SAID FIRST MONOMER IS ONE OF SAID AROMATIC COMPOUNDS BY CONTROLLING THE TEMPERATURE OF SAID SECOND STREAM OF HYDROCARBON DILUENT; CONTINUOUSLY WITHDRAWING FROM SAID PREREACTION ZONE AN EFFLUENT CONTAINING INITIATOR, POLYMER, AND DILUENT; CONTINUOUSLY PASSING SAID EFFLUENT INTO A REACTION ZONE; CONTINUOUSLY INTRODUCING INTO SAID REACTION ZONE A STREAM OF A SECOND MONOMER SELECTED FROM THE ABOVE GROUP OF MONOMERS BUT WHICH IS A DISSIMILAR TYPE OF COMPOUND FROM SAID FIRST MONOMER; MAINTAINING THE CONTENTS OF SAID REACTION ZONE UNDER TURBULENT MIXING CONDITIONS AND UNDER SUFFICIENT PRESSURE TO MAINTAIN SAID CONTENTS SUBSTANTIALLY COMPLETELY IN THE LIQUID PHASE; AND MAINTAINING THE TEMPERATURE IN SAID REACTION ZONE WITHIN THE RANGE OF FROM 180 TO 250*F. WHEN SAID SECOND MONOMER IS ONE OF SAID AROMATIC COMPOUNDS AND WITHIN THE RANGE OF FROM 220 TO 350*F. WHEN SAID SECOND MONOMER IS ONE OF SAID DIENE COMPOUNDS BY CONTROLLING THE TEMPERATURE OF SAID STREAM OF SECOND MONOMER; AND CONTINUOUSLY RECOVERING FROM SAID REACTION ZONE A REACTION MIXTURE CONTAINING SAID BLOCK COPOLYMER; THE TOTAL AMOUNT OF SAID AROMATIC COMPOUND MONOMER USED IN SAID PROCESS BEING WITHIN THE RANGE OF FROM 10 TO 50 PARTS BY WEIGHT PER 100 PARTS BY WEIGHT OF TOTAL MONOMERS TO BE POLYMERIZED.