Anionic polymerization of lactams with volatile promoters

Claim 1

A PROCESS FOR THE ALKALINE POLYMERIZATION OF MONOMER CYCLIC LACTAMS OF MONOAMINO MONOCARBOXYLIC ACIDS CONTAINING FROM 6 TO 12 CARBON ATOMS AND HAVING AT LEAST SIX CARBON ATOMS IN THE LACTAM RING WHICH COMPRISES ENTRAINING, IN A STREAM OF INET GS, A VOLATILE PROMOTER SELECTED FROM THE CLASS CONSISTING OF DIALKYL CARBONATES CONTAINING NOT MORE THAN 4 CARBON ATOMS IN EACH ALKYL GROUP, KETENE, DIMETHYL KETENE, ACETIC ANHYDRIDE, PROPANOIC ANHYDRIDE, BUTANOIC ANHYDRIDE, METHYL ISOCYANATE, ETHYL ISOCYANATE, PROPYL ISOCYANATE, BUTYL ISOCYANATE, PHENYL ISOCYANATE, N-METHYL URETHANE, N-ETHYL URETHANE, ACETYL CHLORIDE, PROPYL CHLORIDE AND BUTYRYL CHLORIDE, PASSING SAID INERT GAS CONTAINING ENTRAINED PROMOTER OVER A MELT OF THE ANHYDROUS LACTAM CONTAINING DISSOVLED ALKALINE CATALYST, THE PROMOTER BEING IN THE VAPOR STATE WHEN IT CONTACTS SAID MELT AND THE POLYMERIZATION BEING CARRIED OUT AT A TEMPERATURE IN THE RANGE OF FROM 150*C. TO A TEMPERATURE WHICH IS 40*C. ABOVE THE SOFTENING POINT OF THE POLYMERIZED LACTAM.