CONTINUOUS BULK POLYMERIZATION PROCESS FOR TRANSPARENT ABS RESIN

摘要

A method for preparing a transparent rubber-modified styrenic resin through a continuous mass polymerization process is provided to obtain an ABS resin having excellent impact strength and processability while maintaining transparency by using a rubber phase and a matrix phase having the same refractive index. The method for preparing a transparent rubber-modified styrenic resin through a continuous mass polymerization process comprises the steps of: (A) reacting a reaction mixture containing a styrene-butadiene monomer dissolved in a reaction medium, styrene monomer, methyl methacrylate monomer and acrylonitrile monomer in a first reactor at 90-130 deg.C for 1-2 hours to form a first polymerizate having a conversion ratio of 10-20%; (B) introducing the first polymerizate continuously into a second reactor and polymerizing it at 110-145 deg.C for 1-2 hours to form a second polymerizate having a conversion ratio of 45-85%; (C) introducing the second polymerizate continuously into a third reactor and polymerizing it at 130-160 deg.C for 0.5-1.5 hours to form a third polymerizate having a conversion ratio of 80-90%; and (D) introducing the third polymerizate into a volatile component remover to remove unreacted monomer and the solvent. In step (A), the monomer mixture is an azeotropic mixture containing 58-78 parts by weight of a styrene monomer, 5-45 parts by weight of a methyl methacrylate monomer and 1-23 parts by weight of an acrylonitrile monomer. In step (B) or (C), at least one of the styrene monomer, methyl methacrylate monomer and acrylonitrile monomer is continuously introduced into the second or the third reactor to allow the rubber phase to have the same refractive index as the matrix phase formed of the monomers.