METHOD FOR CONTINUOUS POLYMERIZATION OF LAUROLACTAM AND ITS APPARATUS

Japanese Patent JPH0551446

A

PURPOSE:To enable practice of prepolymerzation of laurolactam at a conventional low temperature of <=300 deg.C under pressure by specifying the ratio of water added to the laurolactam and internal temperature conditions in the prepolymerization step. CONSTITUTION:Laurolactam in which 1-10wt.% water is added is preheated, then fed and made to continuously flow from the upper part to the lower part of a vertical type polymerizing reaction zone. A temperature gradient of >=10 deg.C lowering in the direction from the upper to the lower parts at 250-300 deg.C polymerizing reaction temperature is provided. In a prepolymerization step, the laurolactam is polymerized up to >=99.5% conversion rate and the pressure is subsequently released from the prepolymerization product obtained from the prepolymerization step to provide an intermediate product under ordinary pressure in an intermediate step. The resultant intermediate product under ordinary pressure from the intermediate step is then continuously fed from the lower end of a horizontal polymerizing zone in the direction to the other end, stirred and evacuated at 220-280 deg.C in the presence of an inert gas under a reduced or normal pressure and post-polymerized until the relative viscosity attains 1.9-3.3.

KAWAKAMI ATSUO
YAMAGUCHI HISAYA
SHIMADA TOSHIRO
TSUMIYAMA TATSUO

JP23536191A

March 02, 1993

August 22, 1991

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UBE INDUSTRIES

B01J19/18; C08G69/04; C08G69/14; C08G69/16; (IPC1-7): C08G69/16

Ippei Watanabe (1 person outside)

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