Patent ID: 6528591
Filing Date: 2003-03-04
Classification: C08F,C08L

Abstract:
A continuous mass polymerization process for making ABS polymer comprising(i) continuously charging a reaction mixture into a first in a series of continuous stirred reactors and under conditions promoting polymerization, the mixture comprising diene rubber in solution of a mixture of monomers, inert solvent and chemical initiator in an amount of 0.02 to 0.05 percent relative to the weight of said reaction mixture to form a first reaction mixture in which the rubber is in the form of a dispersed phase and has a weight average particle diameter of 0.3 to 0.7 microns, (ii) transferring said first reaction mixture into at least one subsequent continuous stirred reactor of said series, optionally along with additional mixture of monomers, and with no addition of chemical initiator, said subsequent reactor operating at a temperature of 130 to 155Â° C. to form a product, and (iii) transferring the product obtained in (ii) to a devolatilizing unit, and (iv) devolatilizing said product, said mixture of monomers, both occurrences containing monoalkenyl aromatic monomers and ethylenically unsaturated nitrile monomers.