Rhone-poulenc Chimie

Rhodia Chimie

Rhone-poulenc Specialites Chimiques

Rhodia Electronics & Catalysis

Rhone-poulenc Specialties Chimiques

Innophos, Inc.

Rhodia Terres Rares

Other

Centre National De La Recherche Scientifique

Rhodia Operations

Jean-Yves Chane-Ching

Jean-Yves Dumousseau

Thierry Chopin

Jean-Luc Le Loarer

Mathias Destarac

Evelyne Prat

Jean-Louis Sabot

Valérie Buissette

Jacques Persello

Thierry Gacoin

Jean-Pierre Boilot

Patrick Dupuis

Gilbert Blanchard

Sylvie Touzet

Thierry Le Mercier

Olivier Anthony

Yves Mottot

Frederic Fabre

Fabrice Fourcot

Bruno Tolla

Corine Gerardin

Gerard Hustache

Nicole Aupaix

Christian Herviou

Albert Lebugle

Frédéric Cobo

The present invention provides calcium phosphate platelets with a length between 250 nm and 800 nm and methods for producing the calcium phosphate platelets. The platelets may be used to provide dispersions or colloidal dispersions obtained by suspending the platelets in the presence of a dispersing agent. The platelets may be used in reinforcing fillers, polishing agents, building materials, additives for oral formulations, in dentrifices or in encapsulating agents.

Nanometric calcium phosphate platelets

The invention provides colloidal dispersions of calcium phosphate platelets comprising at least one polymer which complexes the calcium and in which the length of the platelets, L, is between 5 and 500 nm and in which the thickness of the platelets is between 0.5 and 20 nm. Another subject-matter of the invention is the calcium phosphate platelets obtained by drying the colloidal dispersion according to the invention. The invention also provides a process for preparing these colloidal dispersions of calcium phosphate platelets according to the invention. Finally, another subject-matter of the invention is the use of the abovementioned colloidal dispersions of platelets as food additive, reinforcing filler, thermal insulation filler, pharmaceutical excipient, polishing agent, building materials, additive for oral formulations, in particular dentifrices, or encapsulating agent.

Colloidal dispersion of calcium phosphate platelets, and its process of preparation

Colloidal dispersion of calcium phosphate tablets and method of obtaining the same

The invention concerns a colloidal dispersion of a vanadate or a phosphovanadate of at least a rare earth comprising either a complex-forming agent having a pK higher than 2.5, or an anion of a monovalent acid, soluble in water and having a pKa ranging between 2.5 and 5. The dispersion is obtained by contacting a colloidal dispersion or a dispersion of initial complexes comprising at least a rare earth compound and at least a complex-forming agent or an anion of said monovalent acid and whereof the pH has been adjusted to a value of at least 7, with vanadate ions, then, in adjusting the pH of the resulting medium to a value of at least 9 and heating.

Colloidal dispersion of particles of a rare-earth vanadate or phosphovanadate

The invention concerns a colloidal dispersion of a phosphate of a rare earth and a process for its preparation. The dispersion is characterized in that it comprises anisotropic and disaggregated or disaggregatable particles of a phosphate of at least one rare earth and an anion of a monobasic acid, soluble in water and with a pKa of at least 2.5. It is prepared by a process in which a solution of a salt of at least one rare earth is mixed with phosphate ions while controlling the pH of the reaction medium to a value in the range 4 to 9 and in the presence of a monobasic acid, soluble in water and with a pKa of at least 2.5; the mixture obtained optionally undergoes a maturing step; the precipitate is then separated from the reaction medium; and said precipitate is then dispersed in water.

Dispersion of a rare earth phosphate, and a process for its preparation

The invention concerns an aqueous colloidal dispersion of isotropic particles of a phosphate of at least one rare earth and is characterized in that it comprises either a complexing agent with a pK (cologarithm of the dissociation constant of the complex formed by the complexing agent and said rare earth) of more than 2.5; or an anion of a monobasic acid, soluble in water and with a pKa in the range 2.5 to 5; or said complexing agent and/or said anion of a monobasic acid. In the case of cerium and lanthanum, the mean particle size is at most 20 nm. The dispersions can have a degree of colloid agglomeration of less than 40%.This dispersion can be prepared by forming an aqueous mixture comprising at least one rare earth salt and the complexing agent or monobasic acid anion; by adding a base then phosphate ions to the mixture formed; and heating the mixture obtained. A precipitate is obtained that is re-dispersed in water.

Aqueous dispersion of a rare earth phosphate, and a process for its preparation

An aqueous colloidal dispersion of at least one lanthanide compound and a complexing agent with a pK (cologarithm of the dissociation constant of the complex formed by the complexing agent and the lanthanide cation) or more than 2.5. The dispersion can also include a compound of at least one other element selected from groups IVa, Va, VIIa, VIIa, VIII, Ib and IIb of the periodic table. A process for preparing the dispersion starts by forming an aqueous mixture comprising at least one lanthanide salt, optionally a salt of one of the elements mentioned, and the complexing agent. A base is added to the mixture, which is heated to obtain the dispersion. Methods that use the dispersion are also disclosed.

Aqueous colloidal dispersion based on at least a lanthanide compound and a complexing agent a process for its preparation and use thereof

The colloidal dispersion of the invention is characterized in that it comprises an organic phase; particles of an iron compound in its amorphous form; and at least one amphiphilic agent. It is prepared by a process in which either an iron salt in the presence of an iron complexing agent or an iron complex is reacted with a base, maintaining the pH of the reaction medium at a value of at most 8 to obtain a precipitate, the iron complexing agent being selected from hydrosoluble carboxylic acids with a complexing constant K such that the pK is at least 3 and the iron complex being selected from the products of reacting iron salts with said acids; then the precipitate obtained or a suspension containing said precipitate is brought into contact with an organic phase in the presence of an amphiphilic agent to obtain the dispersion in an organic phase. The dispersion of the invention can be used as a combustion additive in liquid fuel or motor fuel.

Organic colloidal dispersion of iron particles, method for preparing same and use thereof as fuel additive for internal combustion engines

Rare earth phosphate colloidal dispersion and preparation method

The invention relates to an aqueous colloidal dispersion of a compound of cerium and at least one other element M chosen from among the rare earths other than cerium; titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, aluminium, gallium and zirconium. This dispersion is characterized in that it displays a conductivity of at most 5 mS/cm. It is obtained by a process in which there is reacted with a base a mixture of at least one salt of cerium with at least one salt of an element M mentioned above and in the presence of an acid in a quantity such that the atomic ratio H/(Ce+M) is greater than 0.1, then the precipitate from the preceding reaction is re-dispersed in water. The dispersions of this type cane be used in catalysis, in lubrication, in ceramics, in the manufacture of luminophorous compounds, in cosmetics and as anticorrosion agents.

Aqueous colloidal dispersion of a compound of cerium and at least one other element chosen from among the rare earths, transition metals, aluminum, gallium and zirconium preparation process and use

The invention concerns a heat-stable ordered mesoporous or mesostructured material comprising a mineral phase wherein are dispersed particles of nanometric dimension at least partly crystaline, the global crystallinity index of said mesostructured or ordered mesoporous material being less than 10% in volume. The invention also concern a method for obtaining such a material.

Mesostructured material incorporating particles of nanometric dimensions

An organic sol is disclosed comprising titanium oxide particles; an organic liquid phase and at least am amphiphilic compound selected among polyethylene phosphate alkyl ethers. In a first embodiment, the method for preparing said sol mixes said amphiphilic compound and the organic liquid phase, and disperses the titanium oxide particles in the resulting mixture. In a second embodiment, the method forms a mixture of titanium oxide and at least said amphiphilic compound, then disperses said mixture in said liquid phase. A solid compound comprising a mixture of titanium oxide particles and at least an amphiphilic compound selected among these mentioned above is also disclosed.

Organic sol and solid compound based on titanium oxide and amphiphilic compound and preparation methods

An organic sol containing: cerium oxide particles; an organic liquid phase; and at least one amphiphilic compound chosen from polyoxyethylenated alkyl ethers of carboxylic acids, polyoxyethylenated alkyl ether phosphates, dialkyl sulphosuccinates and quaternary ammonium compounds. A process for preparing the sol is characterized in that the abovementioned amphiphilic compound and the organic liquid phase are mixed together and the cerium oxide particles are then dispersed in the mixture obtained. According to a second variant, a mixture of cerium oxide and of at least one abovementioned amphiphilic compound is formed and the said mixture is then dispersed in the organic liquid phase.

Organic sol and solid compound based on cerium oxide and an amphiphilic compound and method for preparing same

Process for preparing mineral particles in the form of colloids in aqueous dispersion of controlled size from a precursor, comprising: a) the step of putting the said precursor, which is a mineral salt of a metal cation, into aqueous solution; b) the complexation of the product obtained in a) with at least one water-soluble block copolymer having at least one complexing anionic hydrophilic block and at least one stabilizing nonionic hydrophilic block; and c) the partial or complete hydrolysis of the said precursor in order to obtain controlled growth of the mineral particles in the form of an aqueous dispersion. Use of said colloids, especially as reinforcing fillers for a polymer.

Process for preparing colloids of particles coming from the hydrolysis of a salt of a metal cation

Aqueous suspension based on alkaline aluminium polysulphate, preparation method and use in the field of building materials

Growing community of inventors

Eaubonne, France

Jean-Yves Chane-Ching