Polyoxymethylene moulding material - contg antimony trioxide pyrophyllite or boron nitride as nucleating agent

摘要

Thermoplastic moulding materials are based on polyoxymethylenes having a reduced specific viscosity of 0.07 - 2.5 dl.g -1 and a m.p. of 150 - 180 degrees C, and contg. spherulites formed during isothermal crystallisation at 1 atm. and 150 degrees C with a diameter of 30 - 250 mu, the polyoxymethylene contg. 0.0005 - 1.0% wt.. nucleating agent selected from antimony trioxide and pyrophyllite. The materials have a good impact resistance, flex resistance and hardness The material contains 0.02 - 0.2% wt. antimony trioxide or 0.01 - 0.2% wt. pyropyllite. The material may contain 0.0005 - 0.04% wt. pref. 0.001 - 0.02% wt. boron nitride as nucleating agent. The antimony trioxide is in the form of valentinite; Sb flowers or is prepd by burning Sb in air at a temp. above the m.p. of antimony. The nucleating agent has a diameter of 1-5 mu.