Uniformly dyeable nylon 66 fiber and process for the production thereof.

摘要

A nylon 66 fiber capable of being uniformly dyed and having an initial modulus at 20°C and a relative humidity of 60% of about 15g/d to about 65g/d and a relationship of a peak temperature [T<Sub>max</Sub>(°C)] at peak of 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) <Sub>max</Sub>] represented by the equation:
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The fiber has such a structure that refractive indices are different between an outer layer of the fiber and an inner layer of the fiber. The fiber is made by extruding a melt of nylon 66, passing the extruded filaments (1) through a heating zone (3) provided at the surface of the extrusion nozzle (2) and having a length of at least about 5 cm and a temperature of about 150°C to about the melting point of the polymer, applying a suction with an aspirator (4) located below the heating zone, and then winding on a roll (7) at a winding speed of at least about 4,000 m/min.