Abstract: Stabilized powder of red phosphorus, for use as flame-retardant agent, in particular for compositions on the basis of polymers, constituted by particles of red phosphorus enveloped by a thin capsule constituted by a first layer of Al(OH).sub.3 adhering on to the surface of red phosphorus individual particles, and by a second layer, superimposed onto said first layer, constituted by a crosslinked polyconsensation resin formed by urea-melamine-phenol-formaldehyde.

Abstract: A process for making self-extinguishing thermoplastic materials based on synthetic polymeric substances by incorporation of red phosphorus into said materials, which comprises the following steps:forming a "concentrate" consisting of 30-70% of a "mother polymeric substance" and of 70-30% of red phosphorus powder previously encapsulated in a modified cationized melamine resin;incorporating said concentrate into a thermoplastic material to be made self-extinguishing and consisting of at least 50% of a polymeric substance similar to or consistent with the substance comprised in said concentrate, the amount of the above-mentioned concentrate being quantitatively so proportioned that the final self-extinguishing thermoplastic material contains 1-15% by weight of encapsulated red phosphorus.

Abstract: 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.degree.-100.degree. 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.degree.-130.degree. C.

Abstract: Self-extinguishing paper materials essentially consisting of paper pulps obtained from virgin chemical or reclaimed cellulose fibers and from red phosphorus powder encapsulated by a modified melaminic resin. These materials find practical industrial appliances especially as paperboard and in papers of various types requiring flame-retarding self-extinguishing characteristics.