METHOD FOR SOLID-PHASE DRYING AND SOLID-PHASE POLYMERIZATION OF POLYAMIDE

摘要

PROBLEM TO BE SOLVED: To provide a method for obtaining a solid-phase dried product or a solid-phase polymerized product of a polyamide which hardly causes an increase in yellowness in solid-phase drying or solid-phase polymerizing a polyamide comprising a diamine containing at least 70 mole% of xylylenediamine and a dicarboxylic acid containing at least 70 mole% of adipic acid. SOLUTION: The method for solid-phase drying and solid-phase polymerizing a polyamide comprises employing a raw polyamide preserved in a light-shielded state at a temperature lower than a glass transition temperature Tg of the raw polyamide under a condition satisfying the following equation (A): 0.8×10-9≥P×D0.5×expä-6002/T+(1-2×C/100)×(a×(h/100-0.6)2+0.62)} [wherein P is an oxygen partial pressure (MPa); (h) is a relative humidity (%RH); D is a preservation time (day); T is a temperature (K); C is a degree of crystallization (%) of the raw polyamide; and (a) is 2.9 when (h) is lower than 60%RH and 18.8 when (h) is not lower than 60%RH]. COPYRIGHT: (C)2003,JPO