Title:
METHOD FOR PURIFYING A RECYCLE STREAM FROM A SYSTEM FOR PRODUCING POLYARYLENE ETHER SULFONES
Document Type and Number:
WIPO Patent Application WO/2014/102310
Kind Code:
A3
Abstract:
Proposed is a method for purifying a recycle stream (1) from a system for producing polyarylene ether sulfones by the polycondensation of aromatic bis-halogen compounds and aromatic bisphenols or salts thereof in the presence of at least one alkali metal- or ammonium carbonate or -hydrogen carbonate in an N-alkyl-2-pyrrolidone as a solvent, containing - 60 to 90% by weight water, - 10 to 40% by weight N-alkyl-2-pyrrolidone and, as a specification-detrimental impurity, up to 5000 ppm by weight of the alkyl succinimide corresponding to the N-alkyl-2-pyrrolidone and, in addition, up to 1000 ppm by weight additional high boilers relative to N-alkyl-2-pyrrolidone, in particular inorganic salts, each relative to the total weight of the recycle stream (1), the sum of the components being 100% by weight, to obtain a pure N-alkyl-2-pyrrolidone stream (2) that can be fed back into the system for producing polyarylene ether sulfones by purification by distillation which is characterized in that the purification by distillation is carried out in a dividing wall column (TK) that has a dividing wall (T) which is arranged in the longitudinal direction of the column and which divides the inner space of the dividing wall column (TK) into a supply region (A), a discharge region (B), an upper common column region (C) and a lower common column region (D), the recycle stream (1) being fed to the supply region (A) of said dividing wall column and divided in the dividing wall column (TK) into a bottom stream (7) containing N-methyl succinimide, a top stream (8) containing water and a pure NMP stream as a side stream (2) from the discharge region (B).
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Inventors:
SIGWART CHRISTOPH (KR)
DE RUITER CORNELIS HENDRICUS (DE)
VONEND JUTTA (DE)
ERBES JÖRG (DE)
DE RUITER CORNELIS HENDRICUS (DE)
VONEND JUTTA (DE)
ERBES JÖRG (DE)
Application Number:
PCT/EP2013/078029
Publication Date:
September 04, 2014
Filing Date:
December 27, 2013
Export Citation:
Assignee:
BASF SE (DE)
International Classes:
C08G75/23; C08J11/02
Foreign References:
| CN101289548A | 2008-10-22 | |||
| CN102276838A | 2011-12-14 | |||
| JP2010083780A | 2010-04-15 |
Attorney, Agent or Firm:
REITSTÖTTER - KINZEBACH (Ludwigshafen, DE)
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