摘要 |
A process for stabilizing by encapsulation red phosphorus powder for using it as flame retardant for polymeric materials, consisting in preparing a red phosphorus dispersion in an aqueous solution of a melamine condensate cationized with a mineral acid, consisting of melamine, formaldehyde, triethanolamine and a monohydroxyl alcohol having up to 5 carbon atoms, in heating the aforesaid dispersion, under stirring, at 80 DEG -100 DEG C. in order to precipitate said condensate in the form of a melamine resin partially cross-linked around the individual red phosphorus particles which are so stabilized by a continuous and compact layer of said resin, then in completing the cross-linking of same in a final dehydration step by drying at 80 DEG -130 DEG C. |