GRAFTING PHASE-INVERSION AND CROSS-LINKING CONTROLLED MUTI-STAGE BSS FOR MAKING ABS GRAFT COPOLYMER

摘要

The present invention provides a method for continuously mass polymerizing a thermoplastic main body of acrylonitrile-butadiene-styrene type. The process feeds a liquid steel feed composition comprising vinylidene aromatic monomer, unsaturated vinyl nitrile monomer and synthetic butadiene polymer dissolved in the monomer into a graft reactor and prereacts to form a grafted rubber continuous phase polymeric product. The product from the graft reactor is then fed to a phase inversion reactor where only the free hard copolymer in the monomer is present in the continuous phase and the dispersed copolymer of the grafted rubber with the hard copolymer and monomer closed. Particles form immediately from the product of the graft reactor. The second polymerization product recovered from the phase inversion reactor is then fed to the workup reactor and further polymerized to form a third polymerization product which is then devolatilized to give the final thermoplastic composition. The process of the present invention provides a unique and flexible method for controlling the graft reaction and rubber particle morphology of rubber. The reaction conditions can be adjusted to produce a high gloss or low gloss resin product.