METHOD FOR PREPARING MELAMINE SALT OF BIS(PENTAERYTHRITOL PHOSPHATE) PHOSPHORIC ACID

摘要

A method for producing a melamine salt of bis(pentaerythritol phosphate) phosphoric acid is proposed. The method includes the steps of reacting and mixing pentaerythritol and diphosphorous pentaoxide in an extruder to carry out esterification to produce bis(pentaerythritol phosphate) phosphoric acid; and mixing bis(pentaerythritol phosphate) phosphoric acid with melamine or a derivative thereof to carry out quaternization in the presence of a solvent, followed by removing water to obtain a melamine salt of bis(pentaerythritol phosphate) phosphoric acid. Diphosphorous pentaoxide is used in the method as a reactant, so that no hydrogen chloride is produced and it is not necessary to recollect trichlorophosphoric acid. Moreover, in the method of the present invention, such that esterification time can be shortened and a high pressure in a closed reaction system that causes explosion can be avoided.