Stabilised, powdered red phosphorus@ - coated with tin oxide hydrate and uncured epoxy] resin as oxidn. stabilisers

摘要

Stabilised, powdered red phosphorus comprises phosphorus particles with a max. particle size of 2mm, the surface of which is covered with a thin layer of an oxidn. stabiliser, which comprises tin oxide hydrate and an uncured epoxy-resin, the proportion of which is 0.2 to less than 5 wt.%. - Mfr. of the red phosphorus involves a water-soluble Sn cpd. being stirred into an aq. suspension of red phosphorus at a pH of 4-9 for 0.5 to 3 hrs. at a temp. of 40-80 deg.C. An aq. emulsion of the epoxy-resin or a soln. of the resin in a solvent miscible with water is then added and stirred for 0.5-3 hrs. at a temp. of 40-80 deg.C. An aq. emulsion of the epoxy-resin or a soln. of the resin in a solvent miscible with water is then added and stirred for 0.5-3 hours at a temp. of 40-80 deg.C, in such a way that the prod. contains more than 85-99.3 wt.% of red phosphorus, 0.5-10 wt.% tin oxide hydrate, calculated as SnO and 0.2-less than 5 wt.% of the resin. The phosphorus particles are then filtered off and dried at high temp. - Pref the red phosphorus is additionally coated with a thin layer of a di-2-ethyl hexyl phthalate as duct formation inhibitor, in a proportion of 0.05-2 wt.%, pref. 0.3-1.5 wt.%. In the mfg. process, the phthalate is added to the stirred mixt. The proportion of tin oxide hydrate, calculated as SnO, is 0.5-10 wt.%, most pref. 1 to 3 wt.%. The proportion of uncured resin is 0.2 to less than 5 wt.%, most pref. 0.5-3 wt.%. The final drying of the filtered off phosphorus particles is effected at a temp. of 80-120 deg.C under nitrogen.