Abstract: A polyamide multifilament has a tensile strength at 15% elongation of 4.0 to 6.0 cN/dtex, a strength-elongation product of 10.0 cN/dtex or more, and a yarn unevenness (U %) of 1.2 or less. The high-strength polyamide multifilament makes it possible to obtain stockings having high softness, durability, and transparency, and a lace knit in which patterns have a beautiful appearance.

Abstract: A biomass resource-derived 1,5-pentamethylene diamine produces a polyamide resin composition having a good color tone. The 1,5-pentamethylene diamine in which a total of the contents of an acetamide, 2,3,4,5-tetrahydropyridine, 2-piperidone, ?-amino-?-caprolactam, lysine and ornithine that the 1,5-pentamethylene diamine contains as impurities is less than or equal to 150 weight ppm.

Abstract: A polyamide resin composition includes (a) a polyamide composed mainly of a polyamide backbone composed of diamine units composed mainly of 5-pentanediamine and dicarboxylic acid units, and (b) a compound with a molecular weight of 1,000 or less having a sterically hindered N atom and a nitrogen-containing functional group that can react with at least one of amino groups, carboxyl groups, and amide groups constituting the polyamide.

Abstract: A polyamide resin composition includes (a) a polyamide composed mainly of a polyamide backbone composed of diamine units composed mainly of 5-pentanediamine and dicarboxylic acid units, and (b) a compound with a molecular weight of 1,000 or less having a sterically hindered N atom and a nitrogen-containing functional group that can react with at least one of amino groups, carboxyl groups, and amide groups constituting the polyamide.

Abstract: A hygroscopic fiber is a fiber including polyamide 56 resin, and having a ?MR of at least 3.0%. A method for manufacturing the fiber is by a direct spin draw method in which: a polyamide 56 fiber discharged through a spinneret is cooled and solidified by cooling air; a spinning oil is deposited thereon and the fiber is stretched; and the fiber is taken up. The manufacturing method satisfies (1) the spinneret discharge line rate is between 14 m/min and 30 m/mm; and (2) the product of the take up velocity and the draw ratio is between 3900 and 4500.