THERMOPLASTIC NITRILE BASED COPOLYMER HAVING EXCELLENT COLOR STABILITY AND METHOD FOR PRODUCING THE SAME

摘要

PURPOSE: Provided are a thermoplastic nitrile based copolymer which contains a high content of unsaturated nitrile compound and has a uniform composition, and which comprises a minimum content of residual monomer and shows excellent tone of color and chemical resistance. CONSTITUTION: The method comprises continuously mass polymerizing 50-70 parts by weight of aromatic vinyl compound, 50-30 parts by weight of unsaturated nitrile compound, 0.10-0.30 parts by weight of molecular weight controlling agent, and 0.05-0.30 parts by weight of antioxidant consisting of primary phenolic antioxidant and secondary phosphite antioxidant. The thermoplastic nitrile copolymer comprises 30-50 wt% of unsaturated nitrile compound and 70-50 wt% of aromatic vinyl compound monomers. Amount of the residual monomers is 0.2% or less. The copolymer shows a transparency of 1.0 or less.