Flame-retardant plastic composition, yarn and textile structure coated therewith

A flame-retarded composite yarn comprising a core and a plastic sheath comprising a halogen-free fire retarded composition, consisting of at least one acrylic resin and an intumescent agent that are dispersed in a plasticizing medium, obtained by the process wherein:

• a) a die suitable for passage of the core of said yarn is used;
• b) the plastic sheath comprising a halogen-free fire retarded composition is used in an ungelled plastisol state;
• c) the core of the yarn is passed through said die, with a peripheral distribution of the plastisol around said core;
• d) rheological properties of the plastisol at a shear rate of the die, at least equal to 20,000 s−1, are adapted by formulating said ungelled plastisol comprising a plasticizing medium comprising predominantly an organic phosphate and a phthalate, so that at low shear rate, at most equal to 400 s−1, it exhibits a Newtownian behaviour, with a viscosity of less than or equal to 6,000 mPa·s, measured with a Brookfield RVT viscometer at 20 rpm, and at high shear rate, at least equal to 10,000 s−1, it exhibits a pseudoplastic behaviour;
• and
• e) the gelling of the fire-retarded composition is carried out, wherein the plastic sheath is halogen free.