| abstract |
Disclosed is a polyamide resin which is produced by the polycondensation of (A) pentamethylenediamine, (B) terephthalic acid and/or a derivative thereof, and (C) at least one member selected from adipic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, isophthalic acid, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, caprolactam, undecalactam, laurolactam, aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and derivatives of these compounds. In the polyamide resin, the ratio of a repeating unit derived from the component (C) is 10 to 50 wt% (inclusive) relative to the total weight of the polymer. A solution of the polyamide resin in 98% sulfuric acid, which contains the polyamide resin at a concentration of 0.01 g/ml, has a relative viscosity of 1.5 to 4.5 at 25°C. |