Polyester fiber dyeable under normal pressure

Abstract

Abstract A fiber consisting essentially of polyethylene terephthalate capable of being dyed under normal pressure and having an initial modulus at 30° C. of about 55 g/d to about 130 g/d, a relationship between a peak temperature ]T max (°C.)] at the peak of a dynamic mechanical loss tangent (tan δ) measured with a frequency of 110 Hz and a peak value of the dynamic mechanical loss tangent [(tan δ) max ] represented by the formula: (tan δ).sub.max ≦1×10.sup.-2 (T.sub.max -105) and a (tan δ) max of about 0.14 to about 0.30 and a dynamic mechanical loss tangent at 220° C. (tan δ 220 ) of at most about 0.055. The fiber is produced by subjecting a polyethylene terephthalate fiber obtained at a spinning speed of at least about 4000 m/min. to heat treatment at a temperature ranging from a temperature at which a dynamic modulus (E') of the fiber deviates from a tangent line at 180° C. of a logarithm of the E' of the fiber-temperature curve (T min ) plus 10° C. to a temperature of completion of melting (T m .sbsb.3) at a melting curve of the fiber measured by a differential scanning calorimeter (DSC) plus 10° C.

Inventors

• 👤 Tomio Kuriki
• 👤 Seiichi Manabe

Bibliographic Details