Method of removing monomeric components from polycaprolactam

Claim 1

METHOD OF REMOVING MONOMERIC COMPONENTS FROM A POLYCAPROLACTAN CONTAINING THE SAME, WHICH COMPRISES CONTACTING SAID POLYCAPROLACTAN WITH A SOLVENT FOR SAID MONOMERIC COMPONENTS WHICH SOLVENT AT NORMAL PRESSURE HAS A BOILING POINT BELOW THE MELTING POINT OF SAID POLYCAPROLACTAM AND WHICH FORMS A EUTECTIC MIXTURE THEREWITH WHILE MAINTAINING A TEMPERATURE ABOVE THE BOILING POINT OF THE PURE SOLVENT AND BELOW THE MELTING POINT OF THE PURE POLYCAPROLACTAM AND AS HIGH AS THE EUTECTIC TEMPERATURE OF SAID MIXTURE AND A PRESSURE WHICH IS SUFFICIENTLY HIGH SO THAT SAID SOLVENT IS IN LIQUID CONDITION AT SAID TEMPERATURE, WHEREBY SAID POLYCAPROLACTAM IS SUBJECTED TO LIQUID-LIQUID EXTRACTION BY SAID SOLVENT ALTHROUGH AT NORMAL PRESSURE SAID SOLVENT WOULD BE IN GASEOUS CONDITION AND SAID POLYCAPROLACTAN WOULD BE IN SOLID CONDITION, SO THAT THE MAJOR PORTION OF SAID MONOMERIC COMPONENTS ARE DISSOLVED BY SAID SOLVENT; AND SEPARATING SAID SOLVENT FROM SAID MIXTURE, THEREBY OBTAINING A POLYCARPROLACTAM OF LOW MONOMERIC COMPONENTS CONTENT.