Polyamide fiber

Abstract

This polyamide fiber is characterized by comprising a polyamide resin obtained by polycondensation of an aliphatic diamine and a dicarboxylic acid, and is characterized in that the aliphatic diamine and/or the dicarboxylic acid is a straight-chain monomer having a carbon chain of at least C9, the biobased content as measured in accordance with the standard ASTM D6866 is at least 50%, and formulae (1) and (2) are satisfied: (1) 1.0≤boiling water shrinkage rate [%]≤5.0; (2) −1.5≤boiling water shrinkage rate [%]−dry heat shrinkage rate [%]≤1.5. Provided is a fiber which, even having biomass plastic used therein, has a high strength, and by which a processed state similar to that of conventional fibers when processed into a woven knitted product is obtained by setting a boiling water-dry heat shrinkage rate to fall within a predetermined range.

Dependencies are inferred from the claim text.