COMPOSITE SALT OF POLYPHOSPHORIC ACID WITH MELAMINE, MELAM, AND MELEM AND PROCESS FOR PRODUCING THE SAME

摘要

A composite salt of polyphosphoric acid with melamine, melam, and melem, characterized by having a solubility in water (25 DEG C) of 0.01 to 0.10 g/100 ml, a pH of 4.0 to 7.0 as measured on its 10 wt.% aqueous slurry (25 DEG C), and melamine, melam, and melem contents of 0.05 to 1.00 mol, 0.30 to 0.60 mol, and 0.05 to 0.80 mol, respectively, per mol of phosphorus atoms. A process for producing the composite salt of polyphosphoric acid with melamine, melam, and melem, which comprises the steps of h: (a) mixing melamine with phosphoric acid at 0 to 330 DEG C in a molar melamine to phosphoric acid (in terms of orthophosphoric acid) ratio of (2.0-4.0)/1 to yield a reaction product, and (b) baking the reaction product thus obtained at 340 to 450 DEG C for 0.1 to 30 hours.