公开(公告)号：DE3820737A1

公开(公告)日：1989-12-21

申请号：DE3820737

申请日：1988-06-18

Applicant: BASF AG

Inventor： FUCHS HUGO DR ,  PITSCHMANN PETER DR ,  SCHMIDT RUDOLF DR

IPC: C07D201/16 ,  C07D223/10

Abstract: Caprolactam is recovered from aqueous solutions by extraction by a) extracting the aqueous solution of caprolactam under a pressure of 100 to 500 bar and at a temperature of 0 to 50@C with an inert water-immiscible extracting agent which is present at 0@C in the gaseous state and under extraction conditions in the liquid or supercritical state, b) separating off the aqueous phase and obtaining a caprolactam-containing extract, c) converting the extracting agent from the caprolactam-containing extract into the gaseous state by warming and/or depressurising and separating off caprolactam and d) recycling the gaseous extracting agent to stage a).

公开(公告)号：DE3938877A1

公开(公告)日：1991-05-29

申请号：DE3938877

申请日：1989-11-24

Applicant: BASF AG

Inventor： GOERTZ HANS-HELMUT DR ,  HUNGENBERG KLAUS-DIETER DR ,  PITSCHMANN PETER DR ,  HATZMANN GUENTER DR ,  OSCHMANN WERNER DR

IPC: C08F2/22 ,  C08F6/00 ,  C08F291/00 ,  C08L27/06 ,  C08L51/04

Abstract: Process for prodn. of a graft copolymer (I) with residual monomer content below 30 ppm comprises (a) prodn. of the graft copolymer by emulsion polymerisation in the usual way, (b) spray drying the prod. to give a powder with d50 100-300 microns and (c) extracting the powder with supercritical CO2 at 31-100 deg.C and 73-350 bar. (I) is e.g. a copolymer with styrene, alpha-methylstyrene, acrylonitrile or 1-12C alkyl (meth)acrylate grafted onto a SB rubber or polyacrylate base; pref. powder has d50a 100-150 microns and is extd. with CO2 at 31-50 deg.C and 79-150 bar. USE/ADVANTAGE - (I) is useful as a modifier for PVC (claimed). In the packaging applications for which such PVC is suitable (bottles for mineral water, etc.), the highly pure (I) is partic. useful as an impact modifier since it has no adverse effect on the taste of the contents.