DEVELOPMENT AND INDUSTRIALIZATION OF A NE W PROCESS FOR MANUFACTURINGMALEIMIDES

maleimides are useful for improving the heat distortion temperature of resins. However, the economical industrial production method for thes e monomers has not been established because of the difficulties during the process operations. We have developed a new industrial production process of maleimides based on the proposed reaction model. This proc ess contains following new technologies; (1) the yield of N-phenylmale imide (PMI) is significantly improved, (2) PMI is directly produced fr om aniline and maleic anhydride (MAN), (3) 2-anilino-N-phenylsuccinimi de (APSI), which is one of the major byproducts, is converted to PMI v ia N-phenyl-N-(l -phenyl-2,5-dioxo-3 -pyrrolidinyl) maleamic acid (PPM A) by the reaction with MAN at elevated temperature, and (4) PMI is th e stabilized by dissolving in acrylonitrile.