公开(公告)号：CA2192536A1

公开(公告)日：1997-06-12

申请号：CA2192536

申请日：1996-12-10

Applicant: HOECHST AG

Inventor： EBMEYER FRANK ,  KAMPMANN DETLEF ,  PAULUS-VON RUSSDORF ULF OTTO ,  ROSSMEISSL RUDOLF

IPC: C07C51/377 ,  C07C51/43 ,  C07C51/487 ,  C07C53/16

Abstract: The present invention relates to a process for the preparation of a particularly pure monochloroacetic acid, in which, in a first step, a hydrogenation of a mixture of mono- and dichloroacetic acid is carried out to a residual content of dichloroacetic acid of 400 to 600 ppm and, in a second step, this mixture is subjected to melt crystallization. The hydrogenation is carried out with a heterogeneous catalyst which comprises 0.1 - 5.0% by weight of palladium and in which active charcoal or silicon dioxide is used as the support.

公开(公告)号：DE59103750D1

公开(公告)日：1995-01-19

申请号：DE59103750

申请日：1991-05-16

Applicant: HOECHST AG

Inventor： DAPPERHELD STEFFEN DR ,  ROSSMEISSL RUDOLF

IPC: C07C53/16 ,  C25B3/25 ,  C25B3/04

Abstract: Trichloro- and dichloroacetic acids are dehalogenated by electrolysing aqueous solutions of these acids in partitioned electrolysis cells using carbon cathodes to produce monochloroacetic acid; the aqueous electrolysis solutions also contain one or more metal salts having a hydrogen overvoltage of at least 0.4 V (at a current density of at least 4,000 A/m ) and special ammonium and/or phosphonium salts. In this process, an extraordinary low evolution of hydrogen occurs at the cathode, even at very low concentration of the polychlorinated acetic acid, without the high selectivity of the electrolysis being impaired during continuous operation.

公开(公告)号：HU9603393A2

公开(公告)日：1997-09-29

申请号：HU9603393

申请日：1996-12-09

Applicant: HOECHST AG

Inventor： EBMEYER FRANK ,  KAMPMANN DETLEF ,  PAULUS-VON RUSSDORF ULF OTTO ,  ROSSMEISSL RUDOLF

IPC: C07C51/377 ,  C07C51/43 ,  C07C51/487 ,  C07C53/16

公开(公告)号：NO965280D0

公开(公告)日：1996-12-10

申请号：NO965280

申请日：1996-12-10

Applicant: HOECHST AG

Inventor： EBMEYER FRANK ,  KAMPMANN DETLEF ,  RUSSDORF ULF OTTO PAULUS-VON ,  ROSSMEISSL RUDOLF

IPC: C07C51/377 ,  C07C51/43 ,  C07C51/487 ,  C07C53/16

公开(公告)号：NO965280A

公开(公告)日：1997-06-12

申请号：NO965280

申请日：1996-12-10

Applicant: HOECHST AG

Inventor： EBMEYER FRANK ,  KAMPMANN DETLEF ,  RUSSDORF ULF OTTO PAULUS-VON ,  ROSSMEISSL RUDOLF

IPC: C07C51/377 ,  C07C51/43 ,  C07C51/487 ,  C07C53/16

CPC classification number: C07C51/43 ,  C07C51/487 ,  C07C53/16

公开(公告)号：ZA9610372B

公开(公告)日：1997-06-11

申请号：ZA9610372

申请日：1996-12-10

Applicant: HOECHST AG

Inventor： EBMEYER FRANK ,  KAMPMANN DETLEF ,  RUSSDORF ULF OTTO PAULUS-VON ,  ROSSMEISSL RUDOLF

IPC: C07C51/377 ,  C07C51/43 ,  C07C51/487 ,  C07C53/16 ,  C07C

公开(公告)号：HU9603393D0

公开(公告)日：1997-02-28

申请号：HU9603393

申请日：1996-12-09

Applicant: HOECHST AG

Inventor： EBMEYER FRANK ,  KAMPMANN DETLEF ,  PAULUS-VON RUSSDORF ULF OTTO ,  ROSSMEISSL RUDOLF

IPC: C07C51/377 ,  C07C51/43 ,  C07C51/487 ,  C07C53/16

公开(公告)号：FI912381A

公开(公告)日：1991-11-19

申请号：FI912381

申请日：1991-05-16

Applicant: HOECHST AG

Inventor： DAPPERHELD STEFFEN ,  ROSSMEISSL RUDOLF

IPC: C07C53/16 ,  C25B3/25 ,  C25B

Abstract: Trichloro- and dichloroacetic acids are dehalogenated by electrolysing aqueous solutions of these acids in partitioned electrolysis cells using carbon cathodes to produce monochloroacetic acid; the aqueous electrolysis solutions also contain one or more metal salts having a hydrogen overvoltage of at least 0.4 V (at a current density of at least 4,000 A/m ) and special ammonium and/or phosphonium salts. In this process, an extraordinary low evolution of hydrogen occurs at the cathode, even at very low concentration of the polychlorinated acetic acid, without the high selectivity of the electrolysis being impaired during continuous operation.

公开(公告)号：NO965280L

公开(公告)日：1997-06-12

申请号：NO965280

申请日：1996-12-10

Applicant: HOECHST AG

Inventor： EBMEYER FRANK ,  KAMPMANN DETLEF ,  RUSSDORF ULF OTTO PAULUS-VON ,  ROSSMEISSL RUDOLF

IPC: C07C51/377 ,  C07C51/43 ,  C07C51/487 ,  C07C53/16

公开(公告)号：BR9102050A

公开(公告)日：1991-12-24

申请号：BR9102050

申请日：1991-05-17

Applicant: HOECHST AG

Inventor： DAPPERHELD STEFFEN DR ,  ROSSMEISSL RUDOLF

IPC: C07C53/16 ,  C25B3/25 ,  C25B3/04

Abstract: Trichloro- and dichloroacetic acids are dehalogenated by electrolysing aqueous solutions of these acids in partitioned electrolysis cells using carbon cathodes to produce monochloroacetic acid; the aqueous electrolysis solutions also contain one or more metal salts having a hydrogen overvoltage of at least 0.4 V (at a current density of at least 4,000 A/m ) and special ammonium and/or phosphonium salts. In this process, an extraordinary low evolution of hydrogen occurs at the cathode, even at very low concentration of the polychlorinated acetic acid, without the high selectivity of the electrolysis being impaired during continuous operation.