High strength, melt spun polypropylene@ fibre, yarn and fabric with high elongation at break

摘要

The claims cover polyolefin fibres and yarns with high strength and elongation at break produced by melt processing, especially fibres with capillary titres of 1-10 dtex, elongation at break 130% and tensile strength = 15 cN/tex that are not redrawn, and textile fabrics produced from them. They consist of polypropylene mixtures containing 0.05-10, preferably 0.2-3 wt.% modified propylene polymers (I) with melt indices of 0.1-50, preferably 1-40 g/10 minutes at 230 deg C/2.16 kg and a ratio of intrinsic viscosity of (I) to the intrinsic viscosity of the unmodified polypropylene of the same weight average molecular weight (Mw) of 0.20-0.95. (I) are obtained by (a) treating propylene homopolymers and/or copolymers of propylene and ethylene and/or 4-18 carbon (C) alpha -olefins with polyfunctional ethylenically unsaturated monomers in the presence of ionising radiation and/or thermal free radical initiators; or (b) reacting functionalised polypropylene, preferably containing acid and/or acid anhydride groups, with polyfunctional compounds of opposite reactivity, preferably 2-16 C diamines and/or 2-16 C diols. Also claimed is a method of making these materials.