| 摘要 |
PROBLEM TO BE SOLVED: To provide a polyamide resin having a high melting point and a high molecular weight through a pressurized and heated polycondensation. SOLUTION: This method for producing the polyamide resin constituted by an aliphatic diamine containing pentamethylenediamine and hexamethylenediamine as main components with a dicarboxylic acid containing terephthalic acid as a main component is characterized by comprising a process of pressurizing/heating for performing the polycondensation of a raw material of which composition is adjusted to become 1.01-1.06 ratio A/B of the total number of moles A of the aliphatic diamine to the total number of moles B of the dicarboxylic acid, in the presence of water under conditions of 10-30 kg/cm<SP>2</SP>pressure and 150-300°C maximum achieved temperature in the polymerization system to obtain a lower condensate satisfying 1.05-1.60 relative viscosity in sulfuric acid, and a process of converting the lower condensate to a condensate having a high degree of polymerization. COPYRIGHT: (C)2004,JPO
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