Colloidal dispersion of particles of a rare earth

专利名称：Colloidal dispersion of particles of a rare

earth vanadate or phosphovanadate

发明人：Jean-Yves Chane-Ching,Thierry Le Mercier申请号：US10489283申请日：20020910

公开号：US20050008877A1公开日：20050113

摘要：The invention concerns a colloidal dispersion of a vanadate or a

phosphovanadate of at least a rare earth characterized in that it comprises either acomplex-forming agent having a pK (cologarithm of the dissociation constant of thecomplex formed by the complex-forming agent and said rare earth) higher than 2.5, or ananion of a monovalent acid, soluble-in water and having a pKa ranging between 2.5 and 5.In the case of a vanadate dispersion, the particles have an average size of not more than 6nm. The inventive dispersion is obtained by a method which consists in contacting acolloidal dispersion or a dispersion of initial complexes comprising at least a rare earthcompound and at least a complex-forming agent or an anion of said monovalent acid andwhereof the pH has been adjusted to a value of at least 7, with vanadate ions and, ifrequired, with phosphate ions, then in adjusting the pH of the resulting medium to avalue of at least 9 and heating.

申请人：Jean-Yves Chane-Ching,Thierry Le Mercier

地址：Eaubonne FR,Paris FR

国籍：FR,FR

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