Method of producing acrylonitrile copolymers

Claim 1

IN A CONTINUOUS METHOD OF PREPARING A POLYMER OF POLYMERIZABLE MONOMERIC MATERIAL COMPRISING A MAJOR PROPORTION BY WEIGHT OF ACRYLONITRILE AND A MINOR PROPORTION BY WEIGHT OF AT LEAST ONE ETHYLENICALLY UNSATURATED MATERIAL WHICH IS COPOLYMERIZABLE WITH ACRYLONITRILE AND WHICH INCLUDES A VINYL-SUBSTITUTED HETEROCYCLIC TERTIARY AMINE, AND WHEREIN THE SAID MONOMERIC MATERIAL IS AND WHICH INCLUDES A VINYL-SUBSTITUTED HETEROCYCLIC TERTIARY AMINE, AND WHEREIN THE SAID MONOMERIC MATERIAL IS CONTINUOUSLY POLYMERIZED IN AN AQUEOUS ACIDIC MEDIUM WITH THE AID OF A WATER-SOLUBLE POLYMERIZATION CATALYST, THE IMPROVEMENT WHICH COMPRISES CONTINUOUSLY CARRYING OUT THE SAID POLYMERIZATION IN TWO STAGES WHICH INCLUDE (1) POLYMERIZATION IN A FIRST ZONE WHEREIN THE CONCENTRATION OF SAID MONOMERIC MATERIAL IN THE AQUEOUS ACIDIC MEDIUM AT THE REACTION TEMPERATURE IS SUCH THAT ALL OF THE MONOMERIC MATERIAL CHARGED TO SAID ZONE IS IN SOLUTION IN THE SAID AQUEOUS ACIDIC MEDIUM AND IS WITHIN THE RANGE OF, BY WEIGHT, FROM ABOUT 1% TO ABOUT 10% OF THE SAID AQUEOUS MEDIUM, THE RESIDENCE TIME IN THE FIRST ZONE OF THE CHARGE THERETO BEING FROM ABOUT 1 MINUTE TO ABOUT 10 MINUTES, AND (2) POLYMERIZATION IN A MAIN REACTION ZONE THAT CONTINUOUSLY RECEIVES THE REACTION MASS FROM THE FIRST ZONE, AS WELL AS ADDITIONAL MONOMERIC MATERIAL TO BE POLYMERIZED THAT WAS NOT CHARGED TO THE FIRST ZONE, THE TOTAL WEIGHT OF POLYMERIZABLE MONOMERIC MATERIAL CHARGED TO THE MAIN REACTION ZONE BEING BETWEEN ABOUT 15% AND ABOUT 50% OF THE TOTAL MATERIAL CHARGED TO THE FIRST AND MAIN REACTION ZONES, THE RESIDENCE TIME IN THE MAIN REACTION ZONE BEING WITHIN THE RANGE OF FROM ABOUT 1/2 TO 2 HOURS; REACTION CONDITIONS IN EACH OF SAID FIRST ZONE AND SAID MAIN REACTION ZONE BEING DIFFERENT TO PRODUCE POLYMER OF SUBSTANTIALLY UNIFORM COMPOSITION AND SUBSTANTIALLY UNIFORM MOLECULAR WEIGHT.