公开(公告)号：US5241066A

公开(公告)日：1993-08-31

申请号：US904223

申请日：1992-06-25

Applicant: Edward A. Davis ,  Jack A. Dellinger

Inventor： Edward A. Davis ,  Jack A. Dellinger

IPC: C07D201/12 ,  C07D201/16

CPC classification number: C07D201/16 ,  C07D201/12

Abstract: A process for recovering caprolactam from waste containing both polycaprolactam and materials which are insoluble in acidic solvents for polycaprolactam includes agitating the waste in an acidic solvent capable of dissolving polycaprolactam without degrading the acid insoluble materials, separating the solution containing polycaprolactam from the acid insoluble materials, feeding the solution containing the polycaprolactam to a depolymerization reactor, without substantially precipitating the polycaprolactam and depolymerizing the polycaprolactam solution to obtain substantially pure caprolactam.

公开(公告)号：US5169870A

公开(公告)日：1992-12-08

申请号：US718720

申请日：1991-06-21

Applicant: Thomas F. Corbin ,  Edward A. Davis ,  Jack A. Dellinger

Inventor： Thomas F. Corbin ,  Edward A. Davis ,  Jack A. Dellinger

IPC: B29B17/02 ,  B29K77/00 ,  B29K105/26 ,  C07D201/12 ,  C08G69/14 ,  C08J11/00

CPC classification number: C07D201/12 ,  C08G69/14 ,  Y02P20/582

Abstract: A process for the continuous recovery of .epsilon.-caprolactam provides a carpet made from nylon 6 fibers and having a backing to a separator to prepare scrap containing nylon 6 and waste. The scrap from the separator is fed to a depolymerizing reactor where the scrap is subjected to a depolymerization catalyst, temperatures of at least the melting point of nylon 6 and superheated steam to produce an .epsilon.-caprolactam containing distillate and more waste. The .epsilon.-caprolactam in the distillate is separated from other volatiles therein; and purified.

公开(公告)号：US3600381A

公开(公告)日：1971-08-17

申请号：US3600381D

申请日：1969-04-21

Applicant: TEIJIN LTD

Inventor： YAMAMOTO AKIRA ,  YASUDA MAKOTO ,  FURUSAWA YUTAKA

IPC: C07D201/12 ,  C07D41/06

CPC classification number: C07D201/12

Abstract: A METHOD FOR THE PREPARATION OF PURE LACTAM FROM AN OLIGOMER-CONTAINING CRUDE LACTAM BY EVAPORATING SAID OLIGOMER-CONTAINING CRUDE LACTAM AT A TEMPERATURE LESS THAN THE EVAPORATION TEMPERATURE OF SAID LACTAM WHILE MAINTAINING SAID LACTAM UNDER ALKALINE CONDITIONS AND THEN RECTIFYING SAID OLIGOMER-CONTAINING CRUDE LACTAM. FURTHER PURIFICATION OF THE CRUDE LACTAM REMAINING AFTER RECTIFICATION CAN BE CARRIED OUT BY DEPOLYMERIZATION OF SAID CRUDE LACTAM IN THE PRESENCE OF AN ACIDIC CATALYST AT A TEMPERATURE WITHIN THE RANGE FROM ABOUT 220*C. TO ABOUT 350*C. AND AT A PRESSURE WITHIN THE RANGE FROM ABOUT 0.5 TO ABOUT 6 ATMOSPHERES, SEPARATING A LACTAM AQUEOUS SOLUTION, OXIDIZING SAID LACTAM AQUEOUS SOLUTION UNTIL THE PERMANGANATE NUMBER OF THE LACTAM IS BELOW 1.50, REDUCING THE WATER CONTENT FROM SAID LACTAM AQUEOUS SOLUTION TO AT LEAST ABOUT 5%, AND RECIRULATING SAID LACTAM AQUEOUS SOLUTION TO SAID EVAPORATING STEP.

公开(公告)号：US2667483A

公开(公告)日：1954-01-26

申请号：US2667483D

CPC classification number: C07D201/16 ,  C07D201/12

公开(公告)号：US2501376A

公开(公告)日：1950-03-21

申请号：US65006746

申请日：1946-02-25

Applicant: GEN ELECTRIC

Inventor： LEONARD BREADNER ROBERT ,  GRAINGER JENKINS HENRY ,  HENRY SIMMS CHARLES

IPC: C07D201/12 ,  H01J61/30 ,  H01J61/94

CPC classification number: C07D201/12 ,  H01J61/307 ,  H01J61/94