| 摘要 |
PROBLEM TO BE SOLVED: To industrially advantageously produce a polyamide of high quality at a low cost which reduces the content of caprolactam and the content of polyamide oligomers in the method for producing the polyamide by using recovered lactams as the raw material or the part of the raw material. SOLUTION: The method for producing a polyamide comprises polymerizing recovered lactams to be obtained by melt volatilization as the part of the raw material or the entire raw material, and the method for producing a polyamide comprises treating the raw material partially or entirely having recovered lactams to be obtained by melt volatilization in the presence of a solid acid under pressure at 200-330°C to produce a polyamide prepolymer, and then polymerizing the prepolymer to produce a polyamide. COPYRIGHT: (C)2003,JPO
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