Abstract: To provide a polyamide resin excellent in lasting thermal stability and having a high biomass ratio. A polyamide resin comprising adipic acid units, pentamethylenediamine units and 6-aminocaproic acid units as constituents, wherein the weight ratio of the sum of the adipic acid units and the pentamethylenediamine units to the 6-aminocaproic acid units is 97:3 to 75:25. The pentamethylenediamine is preferably one produced from lysine using lysine decarboxylase, lysine decarboxylase-producing cells or a treated product of the cells.

Abstract: A polyamide resin comprising a dicarboxylic acid constitutional unit comprising an adipic acid unit and a diamine constitutional unit comprising a pentamethylenediamine unit and a hexamethylenediamine unit wherein a weight ratio of the pentamethylenediamine unit to the hexamethylenediamine unit being in the range of 95:5 to 60:40; a vibration-welded molded product having an excellent vibration welding strength, a hinged molded product and a binding band having an excellent low-temperature toughness, and a filament having an excellent transparency which are obtained from the polyamide resin; and a hinged molded product comprising a polyamide resin constituted of an adipic acid unit and a pentamethylenediamine unit.

Abstract: The present invention relates to an integrally molded article of polyamide resin comprising at least one primary molded pieces made of a primary molding material and at least one secondary molded pieces made of a secondary molding material, and having a welded part, said secondary molding material being injection molded on the surface of said primary molded piece, thereby welding the secondary molded piece comprising the secondary molding material to said primary molded piece, and said primary and secondary molding materials each comprising 100 parts by weight of a polyamide resin and 0.05 to 10 parts by weight of nigrosine or a nigrosine derivative.

Abstract: The present invention relates to a vibration-molded hollow product comprising a polyamide resin composition which comprises(a) 40 to 89.97% by weight of a polyamide resin,(b) 10 to 59.97% by weight of a glass fiber, and(c) 0.03 to 10% by weight of a compound represented by the following formula (1) or formula (2).