Method for treating condensates form polycodensates

Abstract

The invention relates to a method for treating vapours and condensates which arise during the production of polycondensates from bisphenols or high-value phenols by esterification and/or transesterification with alkyl or aryl esters of at least bivalent organic or inorganic acids. According to the invention, the treatment is carried out in a plurality of condensates and/or distillation columns which are connected in a step-by-step manner behind each other, each distillation column comprising a connected condensate. The dew point and the pressure in each condensate are adjusted such that in each step, monomers, oligomers or decomposition and transformation products are removed.

1 . A method of treating vapors and condensates that are produced during the production of polycondensates from bisphenols or polyhydric phenols by esterification of acids and/or transesterification with alkyl and/or aryl esters of at least divalent organic or inorganic acids in a multiple stage polymerization with progressing vacuum wherein the preparation of the vapors and condensates from each stage occurs in several succeeding cascaded condensation steps and distillation columns with respective attached condensers, the dew point and pressure being established in each condenser such that in each stage specific monomers, oligomers, or decomposition and rearrangement products are separated and collected separately. 
   
   
       2 . The method according to  claim 1  wherein the method is used for treating vapors and condensates that are produced during the production of polymers or copolymers based on diphenols, bisphenols, or phenyl esters. 
   
   
       3 . The method according to  claim 1  wherein for the condensation of the distillate recovered in a preparation step, the dew point, temperature, and pressure are selected such that in at least one condenser predominantly the cleavage products or the monomers arising in the esterification and/or transesterification, are separated and collected in a special collection tank. 
   
   
       4 . The method according to  claim 1  wherein for the condensation of the distillate recovered in a preparation step, the dew point, temperature, and pressure are selected such that in at least one condenser predominantly the oligomers arising in the preliminary condensation, are separated and collected in a special collection tank. 
   
   
       5 . The method according to  claim 1  wherein for the condensation of the distillate recovered in a preparation step, the dew point, temperature, and pressure are selected such that in at least one condenser predominantly the reaction products arising during the polycondensation by thermal decomposition or rearrangement are separated and collected in a special collection tank. 
   
   
       6 . The method according to  claim 1  wherein the vapors and condensates are rectified in at least one distillation stage. 
   
   
       7 . The method according to  claim 1  wherein the product mixtures collected in the collection tanks are analyzed and then purified by at least one fine distillation and/or at least one crystallization and supplied taken to the polycondensation. 
   
   
       8 . The method according to  claim 1  through  6  wherein waste products are incinerated.