OBTAINING CAPROLACTAM BY HYDROLYTIC CLEAVAGE OF MOLTEN POLYCAPROLACTAM

CAPROLACTAM IS OBTAINED FROM CAPROLACTAM-CONTAINING POLYMERS IN THE PRESENCE OF SUPERHEATED WATER BY BRINGING POLYMERS WHICH CONTAIN THE REPEATING UNIT -[-N (H)- (CH2) 5-C (O)- ]-OR MIXTURES CONSISTING ESSENTIALLY OF FROM 40 TO 99.9BY WEIGHT OF A POLYMER CONTAINING THE REPEATING UNIT -[-N (H) - (CH2) 5- C(O) - ]-,FROM 0.01 TO 50BY WEIGHT OF ADDITIVES SELECTED FROM THE GROUP CONSISTING OF INORGANIC FILLERS, ORGANIC AND INORGANIC PIGMENTS AND DYES,FROM 0 TO 10BY WEIGHT OF ORGANIC AND/OR INORGANIC ADDITIVES,FROM 0 TO 40BY WEIGHT OF NON-POLYAMIDE-CONTAINING POLYMERS ANDFROM 0 TO 60BY WEIGHT OF POLYAMIDES, WITH THE EXCEPTION OF POLYCAPROLACTAM AND COPOLYAMIDES PREPARED FROM CAPROLACTAM,INTO CONTACT WITH SUPERHEATED WATER AT FROM 280 TO 320?C AND FROM 7.5 TO 15 MPA AND A WEIGHT RATIO OF WATER TO POLYMER CONTAINING THE REPEATING UNIT -[-N (H) -(CH2)5- C(O)- ]- OF FROM 5:1 TO 13:1 AND IN A REACTION TIME OF LESS THAN 3 HOURS, WITH THE PROVISO THAT THE REACTION MIXTURE, CONSISTING ESSENTIALLY OF WATER AND THE POLYMER USED OR THE MIXTURE USED, CONTAINS NO GASEOUS PHASE UNDER THE CONDITIONS OF THE HYDROLYSIS.FIGURE 1