Continuous mass polymerization process for ABS polymeric polyblends

Claim 1

IN A CONTINUOUS MASS POLYMERIZATION PROCESS FOR PREPARING A POLYMERIC POLYBLEND, THE STEPS COMPRISING IN THE SEQUENCE SET FORTH: A. CONTINUOUSLY MASS POLYMERIZING MONOMERS CONTAINING 0. 1 TO 15% BY WEIGHT OF A SOLUBLE DIENE RUBBER SO AS TO CONVERT 10 TO 40% OF SAID MONOMERS TO A POLYMER, GRAFT AT LEAST A PORTION OF SAID DIENE RUBBER AND DISPERSE SAID RUBBER AS A FIRST GRAFTED DIENE RUBBERMONOMER PHASE IN A MONOMER-POLYMER PHASE, TO PROVIDE A FIRST PARTIALLY POLYMERIZED MIXTURE, SAID MONOMERS COMPRISING AT LEAST PRINCIPALLY A MONOALKENYLAROMATIC MONOMER AND AN ETHYLENICALLY UNSATURATED NITRILE MONOMER, SAID FIRST GRAFTED DIENE RUBBER-MONOMER PHASE BEING DISPERSED BY SHEARING AGITATION OF SAID FIRST PARTIALLY POLYMERIZED MIXTURE AS RUBBER-MONOMER PARTICLES HAVING AN AVERAGE PARTICLE SIZE OF 0. 7 TO 10 MICRONS AND HAVING PRESENT OCCLUDED AND GRAFTED POLYMER, B. CONTINUOUSLY WITHDRAWING SAID FIRST PARTIALLY POLYMERIZED MIXTURE FROM STEP (A), C. CONTINUOUSLY MASS POLYMERIZING SAID FIRST PARTIALLY POLYMERIZED MIXTURE UNDER SHEARING AGITATION UNTIL THE POLYMERIZATION OF SAID MONOMER FORMULATION HAS REACHED A CONVERSION OF ABOUT 25 TO 80% TO PROVIDE A SECOND PARTIALLY POLYMERIZED MIXTURE, FOLLOWED BY WITHDRAWING SAID SECOND PARTIALLY POLYMERIZED MIXTURE FROM STEP (C), D. CONTINUOUSLY DISPERSING A SECOND GRAFTED DIENE RUBBER INTO SAID SECOND PARTIALLY POLYMERIZED MIXTURE, SAID SECOND GRAFTED RUBBER COMPRISING CROSSLINKED RUBBER PARTICLES HAVING A SWELLING INDEX OF AT LEAST 2, AN AVERAGE PARTICLE SIZE OF 0.01 TO 0.5 MICRONS AND BEING GRAFTED WITH ABOUT 0.1 TO 2.5 PARTS OF SAID MONOMERS PER 1 PART OF RUBBER FORMING A THRID PARTIALLY POLYMERIZED MIXTURE CONTAINING 1 TO 30 WEIGHT PERCENT OF SAID FIRST AND SECOND GRAFTED RUBBERS WHEREIN THE SECOND GRAFTED RUBBER COMPRISES FROM ABOUT 50 TO 97% OF THE TOTAL WEIGHT OF SAID FIRST AND SECOND GRAFTED DIENE RUBBERS, E. CONTINUOUSLY DEVOLATILIZING SAID THRID PARTIALLY POLYMERIZED MIXTURE TO PROVIDE A POLYMERIC POLYBLEND COMPRISING ABOUT 2 TO 40% BY WEIGHT OF SAID FIRST AND SECOND GRAFTED DIENE RUBBERS WHEREIN SAID SECOND GRAFTED DIENE RUBBER COMPRISES ABOUT 50 TO 97% OF THE TOTAL WEIGHT OF SAID FIRST AND SECOND GRAFTED DIENE RUBBERS, THE REMAINDER UP TO 100%, BEING POLYMER OF SAID MONOMERS, SAID FIRST GRAFTED DIENE RUBBERS BEING DISPERSED AS RUBBER PARTICLES HAVING AN AVERAGE PARTICLE SIZE OF 0.7 TO 10 MICRONS, A SWELLING INDEX OF AT LEAST 5 AND HAVING PRESENT OCCLUDED AND GRAFTED POLYMER IN AN AMOUNT OF ABOUT 1 TO 5 PARTS PER EACH PART OF RUBBER.