Continuous preparation of polyamides wherein relative viscosity and amineend value of final product are maintained constant

Claim 1

IN A CONTINUOUS SYSTEM OF POLYMERIZATION WHERIN (1) A POLYMER IS PRODUCED BY CONTINOUS POLYMERIZATION OF AN INITIAL AQUEOUS SOLUTION OF A SLAT OF A DIAMINE AND A DICARBOXYLIC ACID;(2) FINAL QUANTITIES OF WATER ARE SEPARATED FROM THE RESULTANT POLYMER UNDER PRESSURE; AND (3)THE POLYMER IS TRANSFERRED FROM THE POINT OF FINAL WATER SEPARATION TO A ZONE OF EXTRUSION WHILE HOLDING IT UP FOR A FIXED, PREDETERMINED TIME INTERVAL UNDER CONSTANT TEMPERATURE, A PROCESS FOR MAINTAINING THE RELATIVE VISCOSITY AND THE AMINE-END VALUE OF THE FINAL PRODUCT CONSTANT DURING AN INCREASE IN THROUHPUT RATE BY: (1) INCREASING THE SALT CONCENTRATION IN THE AFORESAID INITIAL AQUEOUS SOLUTION WITHIN THE RANGE OF ABOUT 50 TO 70 WEIGHT PERCENT; (2) DECREASING THE STEAM PRESSURE UNDER WHICH THE FINAL QUANTITIES OF WATER ARE SEPARATED FROM THE POLYMERIZED PRODUCT WITHIN THE RANGE OF ABOUT 0 TO 10 P.S.I.G.; AND (3) HOLDING THE TEMPERATURE AND THE TIME INTERVAL FOR THE TRANSFER OF POLYMER FROM THE POINT OF LAST WATER SEPARATION TO THE POING OF EXTRUSION CONSTANT.