Multifilament-Garn aus Polyäthylennaphthalat und Verfahren zu seiner Herstellung

摘要

Multifilament yarn, monofilament or filmlike structure composed at least predominantly of polyethylene naphthalate and having a strength of at least 400 mN/tex, characterised in that it has a DSC melting point of at least 292 DEG C, the DSC melting point being measured on a sample of 2.5 mg at a heating rate of 20 DEG C per min. It preferably contains at least 95% by weight of polyethylene-2,6-naphthalate. Production is by extruding molten polyethylene naphthalate from a multihole spinneret and taking off the cooled solidified filaments or the rigidified film at a speed of 500 to 10,000 m/min, the filaments or film being subjected between the spinneret and the first take-off element to a draw-down B of 40 to 25,000. The polymer used contains at least 85% by weight of polyethylene naphthalate and has a melt flow index C of 3 to 26.