| 摘要 |
PURPOSE: To efficiently obtain a polyamide, especially that having various terephthalic acid components, improved in hue, tensile strength, elongation and dimensional stability. CONSTITUTION: This process for the production of this polyamide comprises the following steps, in the named order, of: (A) synthesizing a primary condensate with a relative viscosity (ηr) ranging from 1.04 to 2.5 at 25 deg.C in its 1% sulfuric acid solution, at temperatures ranging from 150 to 350 deg.C in a polymerization vessel, (B) discharging the primary condensate from the polymerization vessel, and (C) bringing the primary condensate to a higher degree of polymerization. The expansion magnification of the primary condensate discharged from the polymerization vessel is within the range between 1.01 and 100.
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