| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for efficiently and stably producing, a polyamide prepolymer and a polyamide suitable as a material for fibers and resins, which are reduced in the content of a cyclic oligomer, in particular, of a cyclic dimer, by decreasing the amounts of a monomer and oligomers after polyamide preparation, and to provide a method capable of simplifying the post-processing step of removing olygomers and a purification step and producing a polyamide with a high production efficiency and at a low energy cost. SOLUTION: The method for producing polyamide prepolymer comprises continuously supplying an aqueous caprolactam solution to a lower part of a reactor, reacting under a condition in which no gas-phase exists in the reactor, and continuously taking out polyamide prepolymers from the upper part. COPYRIGHT: (C)2008,JPO&INPIT
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