METHOD OF PREPARING ALUMINIUM METHYLPHOSPHITE Russian patent published in 2000 - IPC

FIELD: chemical industry. SUBSTANCE: described is method of preparing aluminium methyl phosphite which is effective fireproofing compound of polymeric compositions. Method comprises reacting phosphorus-containing agent with aluminium hydroxide. Phosphorus-containing agent includes phosphite containing 74.2-83.0 mole % of dimethylphosphorous acid, 15.6-24.3 mole % of monomethylphosphorous acid, 1.56-1.8 mole % of phosphorous acid. Phosphite mixture is preheated to 150 C to obtain additional amount of monomethylphosphorous acid, and process is carried out at aluminium hydroxide to phosphite mixture molar ratio from 1-3 to 4-12, at temperature of 80 C and pressure of 130-120 mm Hg. EFFECT: simplified method of preparing aluminium methylphosphite, shorter process period of time and lower process temperature. 9 ex, 1 tbl