A melamine-coated ammonium polyphosphate exhibiting properties of having no hygroscopicity, being difficultly soluble in water and difficultly susceptive of hydrolysis is provided and further a process for producing a melamine-coated ammonium polyphosphate having the above properties and also being powdery even when it is not ground is provided, the above powdery, melamine-coated ammonium polyphosphate being characterized in that melamine is added and/or adhered onto the particle surface of a powdery, ammonium polyphosphate expressed by the formula ##STR1## wherein n represents an integer of 20 or more, and a process for producing a powdery, melamine-coated ammonium polyphosphate being characterized in that melamine is sublimated and added and/or adhered onto the particle surface of a powdery ammonium polyphosphate.
A fire retardant material comprising both ammonium polyphosphate particles microencapsulated within a melamine or melamine-based resin and melamine-based particles retained in a base material. The material may be applied to a textile article or incorporated into an article during formation thereof.
Thermoplastic resin-coated ammonium polyphosphate comprises a core material which comprises ammonium polyphosphate and a thermosetting resin, a melamine monomer or a surface-treating agent; and a coating layer of a thermoplastic resin which covers the core material. The thermoplastic resin-coated ammonium polyphosphate is excellent in water resistance, resistance to acids, resistance to alkalis, resistance to ions and resistance to organic solvents and if it is incorporated into a resin composition as a component of a flame retardant used therein and the composition is formed into a molded article, the resulting article does not show any marked reduction of its mechanical strength.