发明授权
US5068308A Continuous preparation of aromatic polycondensates 失效
连续制备芳香族聚氧乙烯

Continuous preparation of aromatic polycondensates
摘要:
Aromatic polycondensates are prepared in a continuous process froma) aromatic hydroxy-, thio- and/or amino-carboxylic acids,b) aromatic dihydroxy-, dithio-, diamino- and/or hydroxy-amino compounds,c) urea as an optional component andd) a molar amount equivalent to the sum of components b) and c) of aromatic dicarboxylic acids,by1. reacting components a), b), d) and optionally c) with lower fatty acid anhydrides in excess at from 140.degree. to 280.degree. C. with distillative removal of fatty acids and fatty acid anhydrides,2. passing the oligomer mixture downward through a perpendicular precondensation zone to form a two-phase mixture of prepolymers and vaporous fatty acids,3. separating the prepolymers from the vaporous fatty acids and4. condensing the prepolymer in a condensation zone to give a granulable polycondensate.
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