| 摘要 |
In a continuous process for the manufacture of aromatic polyesters by polycondensation of mono- or multi-nuclear substituted or unsubstituted diphenols, with halides of aromatic dicarboxylic acids according to the two-phase interface polycondensation process, the first step is to produce continuously a fine pre-emulsion with an organic solvent and from the aqueous phase, consisting of a solution obtained from the diphenols, of an alkaline hydroxide in order to form the diphenates and possibly of a phase transfer catalyst in water or in a mixture of water and of an organic solubilizer. This pre-emulsion is fed in quantities to a dispersion unit jointly with the organo-liquid phase forming the acid chloride solution. The compounds involved in the polycondensation reaction are mixed in the dispersion unit in constant proportions in order to produce a reaction emulsion which then passes successively through one or several dispersion units and/or into static mixers, the polycondensation taking place and being completed during this period. The phases are then separated and the polyester formed is precipitated from the organic phase. |
