| abstract |
The present invention provides a styrene-acrylonitrile (SAN) resin that exhibits significantly improved thermal resistance and, at the same time, can be produced at high productivity and is highly processable and highly moldable; and a method of producing the same by preparing and storing the solution containing a mixture of an N-substituted maleimide monomer and an unsaturated nitrile monomer at a particular temperature, introducing the solution and a styrene polymer into the polymerization reactor separately, and maintaining the first polymerization reactor and the second polymerization reactor at particular respective temperatures, thereby significantly reducing the amounts of oligomers contained in the SAN resin. |