Patent ID: 9090637
Filing Date: 2015-07-28
Classification: A61K,C07F

Abstract:
1. A process for the synthesis of a rare-earth organophosphate comprising: dispersing, under high shear, in a mixer having agitator impellers, a rare-earth oxide in a two-phase medium comprising at least one organic solvent, water, an organophosphoric acid and an organic or mineral acid and, simultaneously or sequentially, reacting the rare-earth oxide with the organophosphoric acid and the organic or mineral acid, wherein the two-phase medium is driven, during the dispersion, by a shear rate of greater than 200 s −1 , expressed by the equation: in which k is a constant ranging from 10 to 13 and N is the rotation speed of the agitator impellers expressed in s −1 , by a blade tip peripheral speed of greater than 4 m/s, expressed by the equation: in which D is the diameter of the agitator impellers expressed in meters and N is their rotational speed expressed in s −1 wherein the organic or mineral acid is selected from the group consisting of perchloric acid HClO 4 , chloric acid HClO 3 , chlorous acid HClO 2 , hydrochloric acid HCl, bromic acid HBrO 3 , hydrobromic acid HBr, iodic acid HIO 3 , periodic acid HIO 4 , orthoperiodic acid H 5 IO 6 , hydroiodic acid HI, trichloroacetic acid CCl 3 —COOH, dichloroacetic acid CCl 2 H—COOH, trifluoroacetic acid CF 3 COOH, nitric acid HNO 3 , peroxonitric acid HNO 4 , sulphurous acid H 2 SO 3 , sulphuric acid H 2 SO 4 , lithium, sodium or potassium hydrogen sulphates, fluorosulphuric acid FSO 3 H, sulphonic acid HSO 3 H, trifluoromethanesulphonic acid CF 3 —SO 3 H 4 , benzenesulphonic acid, naphthalenesulphonic acid, phosphoric acid H 3 PO 4 , lithium, sodium or potassium hydrogen phosphates, pyrophosphoric acid H 4 P 2 O 7 , phosphorous acid H 3 PO 3 , hypophosphorous acid H 3 PO 2 , chromic acid H 2 CrO 4 , picric acid, maleic acid, oxalic acid, and mixtures thereof.