公开(公告)号：DE19752183A1

公开(公告)日：1999-05-27

申请号：DE19752183

申请日：1997-11-25

Applicant: BASF AG

Inventor： ERBES JOERG DR ,  LUDWIG ALFONS DR ,  PIPPER GUNTER

IPC: C08J3/12 ,  B01D11/02 ,  B29B9/16 ,  C08G69/00 ,  C08G69/04 ,  C08G69/16 ,  C08G69/46 ,  C08G69/14 ,  C08L77/02 ,  B01D11/00

Abstract: Continuous extraction of polyamide particles with an aqueous extraction medium in an essentially vertical extraction column comprises using subdivided extraction columns in two zones, with extraction in the first zone with 40-95 wt.% aqueous caprolactam and in the second zone with water. An Independent claim is included for an extraction column for use in the above process comprising a first zone (2) with a means for adding and removing an extraction medium and a second zone (3), where the ratio of length of zone 1 to zone 2 is 1:5-5:1 and of diameter is 8-2:1.