| 摘要 |
<p>To provide polyamide fibers such as polyhexamethyleneadipamide fiber having high strength and excellent strength retention after vulcanization and GY fatigue life as a rubber reinforcement. This fiber is a high-strength polyamide fiber, preferably a polyhexamethyleneadipamide fiber composed of at least 95 mol % of hexamethyleneadipamide units and having a relative viscosity in a sulfuric acid of at least 3.0, and satisfies the following requirements: (a) δΔn»-5x10?-3-0x10-3¿, wherein δΔn is differential birefringence, (b) Dm»105 Å and De»90-130 Å, wherein Dm is a long period in the direction of fiber axis and De is one in the direction perpendicular thereto, and (c) Tα»125 °C, wherein Tα is a principal dispersion peak temperature in the mechanical loss factor (tan δ) curve obtained by dynamic viscoelastic measurement, and preferably satisfies further the following requirements: (d) Δn»60x10-3, wherein Δn is birefringence, (e) fc»0.88, wherein fc is degree of crystalline orientation, and (f) fa = 0.70-0.85, wherein fa is degree of non-crystalline molecule orientation.</p> |
