公开(公告)号：CZ20001930A3

公开(公告)日：2000-11-15

申请号：CZ20001930

申请日：1998-11-24

Applicant: BASF AG

Inventor： HILDEBRAND PETER ,  LANG REINHARD ,  LUDWIG ALFONS ,  PIPPER GUNTER

IPC: C08J3/12 ,  B29B9/16 ,  C08G69/16 ,  C08G69/46

Abstract: A process for continuous extraction of polyamide particles in an essentially vertical extraction column using an aqueous extractant comprises using an extraction column that is divided into two zones and performing an extraction with a recirculating 15-40% strength by weight aqueous epsi-caprolactam solution in the first zone and then with countercurrent water at a from 5 to 40° C. lower temperature in the second zone. The process provides for economical extraction of polyamides with a low level of monomers and oligomers.

公开(公告)号：CZ290277B6

公开(公告)日：2002-06-12

申请号：CZ20001930

申请日：1998-11-24

Applicant: BASF AG

Inventor： HILDEBRAND PETER ,  LANG REINHARD ,  LUDWIG ALFONS ,  PIPPER GUNTER

IPC: C08J3/12 ,  B29B9/16 ,  C08G69/16 ,  C08G69/46

Abstract: Disclosed is a continuous extraction process of polyamide particles by means of a circulating aqueous extraction solution within a closed circuit and in substantially stand-up extraction column divided in two zones, wherein in the first zone polyamide is treated with aqueous solution of {epsilon}-caprolactam with concentration ranging within 15 to 40 percent by weight as an extraction agent at a temperature ranging from 100 to 140 degC and subsequently in the second zone it is additionally extracted with water with temperature being by 5 to 40 degC lower. The invented process enables economical manufacture of polyamide with low content of monomer and oligomers.