Derivative of phosphoric acid ester salt or phosphoric acid ester adduct or mixtures thereof, method for the production thereof and their use

A derivative of phosphoric acid ester salt or adduct or a mixture thereof is obtained from a reaction product, polycondensed with at least one aldehyde, of at least one polyol phosphoric acid ester with at least one organic nitrogen base. The derivative is advantageously used as a flame-inhibiting and/or intumescent treatment in plastic mouldings, on porous carriers or in paint or coating systems. The production of the derivative or a mixture thereof by reacting at least one polyol with phosphorus pentoxide and reacting the polyol phosphoric acid ester obtained in that way with at least one organic nitrogen base forming a phosphoric acid ester salt or adduct, is characterized in that the amount of phosphorus pentoxide required for the esterification operation is suspended in an amount of the ester or ester mixture to be produced, then at a temperature in the range of 20-180° C. the amount of polyol required for the esterification operation and optionally water is added, then the esterification reaction is allowed to take place substantially completely and thereafter the product is obtained and finally the salt or adduct obtained by reaction of that product with the organic nitrogen base is polycondensed with at least one aldehyde.