PHLEGMATIZED RED PHOSPHORUS

摘要

HOE 89/H 008 Phlegmatized red phosphorus : Phlegmatized, pulverulent red phosphorus with good freeflowing properties comprises 95 to 99.95 % by weight of red phosphorus having a particle size of up to 2 mm, and 0.05 to 5 % by weight of polyurethane as phlegmatization agent. This red phosphorus is prepared by introducing an aqueous polyurethane dispersion into an aqueous suspension of red phosphorus having a particle size of up to 2 mm, after a pH of from 5 to 9 has been set, in a manner such that 5 to 0.05 parts by weight of polyurethane are present per 95 to 99.95 parts by weight of red phosphorus, then stirring the mixture at a temperature of from 20 to 90.degree.C for 0.5 to 3 hours, and finally drying the phlegmatized red phosphorus at elevated temperature after filtration.