| 摘要 |
<p>A composite salt of polyphosphoric acid with melamine, melam, and melem, characterized by having a solubility in water (25 °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 °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 °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 °C for 0.1 to 30 hours.</p> |
