| abstract |
PURPOSE: To prepare a water-soluble flame-retardant having remarkably improved solubility in water, and capable of imparting a material with flame-retardancy uniformly and easily, by using a condensed ammonium phosphate and a mixture of urea and its derivatives. n CONSTITUTION: An aqueous solution of phosphoric acid is heated at 50W100°C, added with urea, and further heated at 115W125°C to perform the condensation reaction to obtain a water-soluble flame-retardant having high solubility in water, and composed of a highly condensed ammonium phosphate having an average condensation degree of 20W60, and a by-produced urea derivatives (a mixture of urea, biuret, triburet, cyanuric acid, etc.). The weight ratio of the condensed ammonium phosphate to the urea derivatives is pref. 2/1W10/1, and the concentration of the sum of the above components in the solution is pref. 10W50wt%. n COPYRIGHT: (C)1980,JPO&Japio |