The vanadate of the rare earth element or colloid dispersing element null of the phospho vanadate

摘要

In the colloidal dispersion of particles of the phosphodiester vanadate or vanadium salt of one rare-earth element, the present invention is formed by the rare earth elements (complexing agent pK of 2.5 or more as a complexing agent at least on colloidal dispersion characterized in that it comprises one of the anions of the monovalent acid having a pKa of 2.5 to 5 soluble in water or which have an extra logarithm) of the dissociation constant of the complex is. In the case of vanadate dispersion, the particles have an average size of at most 6nm. The dispersion of the present invention, the pH is adjusted to a value of at least 7 and an initial colloidal dispersion of rare earth element at least one compound containing an anion of an acid or a monovalent complexing agent at least one An initial dispersion of complexes based on anions of monovalent acid rare earth element compound, or a complexing agent or things,, OH ^- and further contain anions, the pH is adjusted to a value of at least 7 is obtained by heating the said medium, and adjusted to a value of at least 9 and the pH of the medium in which phosphate ions both into contact if necessary were but also, and vanadate ions one, was obtained.