Patent application number | Description | Published |
20090140204 | Precursor compound and crystallised compound of the alkaline-earth aluminate type, and methods of preparing and using the crystallised compound as phosphor - The invention relates to an alkaline-earth-aluminate-type compound which is at least partially crystallised such as in the form of a beta- or tridymite-type alumina Said compound can be used as phosphor in plasma-type screens or in trichromatic lamps, backlights for liquid crystal displays or plasma excitation lighting or in light-emitting diodes. The invention also relates to a precursor compound of the aforementioned compound. | 06-04-2009 |
20090256115 | COLLOIDAL DISPERSIONS OF RARE-EARTH BORATES, PREPARATION THEREOF AND LUMINOPHORES PRODUCED THEREFROM - Colloidal dispersions of rare-earth borates include a liquid phase and borate colloids dispersed therein, these colloids having a mean hydrodynamic diameter of at most 200 nm and consisting essentially of elementary particles having a mean size of less than 100 nm; such dispersions are prepared by: (a) reacting a rare-earth oxide with a controlled amount of a water-soluble monovalent acid, having a pKa of from 2.5 to 5.0; (b) heating the medium thus obtained; (c) adding boric acid to the medium obtained and heating the resulting mixture; and (d) separating the solid product from the liquid medium thus obtained, and redispersing same in a liquid phase (the subject borates are useful luminophores, especially for the manufacture of luminescent transparent materials). | 10-15-2009 |
20100051868 | LUMINOPHORES AND CORE-SHELL LUMINOPHORE PRECURSORS - A novel type of green luminophore containing mixed rare-earth phosphates is produced from precursor particles having a mean diameter ranging from 1.5 to 15 microns; such particles have an inorganic core and a shell of a mixed lanthanum and/or cerium phosphate, optionally doped with terbium, evenly covering the inorganic core with a thickness greater than or equal to 300 nm. | 03-04-2010 |
20110068303 | SUBMICRONIC BARIUM AND MAGNESIUM ALUMINATE PHOSPHORS - Submicronic barium and magnesium aluminates, useful as phosphors, are in the form of a liquid-phase suspension of substantially monocrystalline particles having an average particle size ranging from 80 to 400 nm; such aluminates are prepared by a process that includes: providing a liquid mixture containing compounds of aluminum and of other elements that are part of the aluminate composition; drying the mixture by atomization; calcining the dried product in a reducing atmosphere and wet-grinding this product. | 03-24-2011 |
20110133124 | SUSPENSIONS OF PHOSPHATES OF AT LEAST ONE RARE EARTH ELEMENT SELECTED FROM AMONG CERIUM AND TERBIUM AND OPTIONALLY LANTHANUM AND LUMINOPHORES PRODUCED THEREFROM - Phosphate particulates of at least one rare-earth metal (Ln), with Ln being at least one rare-earth metal selected from among cerium and terbium and optionally lanthanum are in the form of a suspension in a liquid phase of primary isotropic monocrystalline monazite particles having an average size of at least 25 nm and agglomerated into secondary particles having an average size of at most 400 nm; useful luminophores are produced from such phosphate particulates. | 06-09-2011 |
20110272632 | CERIUM AND/OR TERBIUM PHOSPHATE OPTIONALLY WITH LANTHANUM, PHOSPHOR RESULTING FROM SAID PHOSPHATE AND METHODS FOR PREPARING SAME - A rare earth (Ln) phosphate is described, wherein Ln is either: (1) at least one rare earth selected from cerium and terbium, or (2) lanthanum in combination with at least one of the two above-mentioned rare earths, and wherein the phosphate has a crystalline structure of the monazite type with a potassium content of at most 6000 ppm. The phosphate can be obtained by the precipitation of a rare earth chloride at a constant pH lower than 2, by calcination at a temperature of at least 700° C. and by redispersion in hot water. A phosphor obtained by calcination of said phosphate at at least 1000° C. is also described. | 11-10-2011 |
20110272633 | CERIUM AND/OR TERBIUM PHOSPHATE OPTIONALLY WITH LANTHANUM, PHOSPHOR RESULTING FROM SAID PHOSPHATE AND METHODS FOR PREPARING SAME - A rare earth (Ln) phosphate is described, wherein Ln is either: ( | 11-10-2011 |
20110272634 | CERIUM AND/OR TERBIUM PHOSPHATE OPTIONALLY WITH LANTHANUM, PHOSPHOR RESULTING FROM SAID PHOSPHATE AND METHODS FOR MAKING SAME - A rare earth element phosphate (Ln) is described, wherein Ln is either: (1) at least one rare earth element selected from cerium and terbium, or (2) lanthanum in combination with at least one of the above two rare earth elements, and wherein the phosphate has a crystalline structure either of the rhabdophane type with a sodium content of at most 6000 ppm, or of the monazite type with a sodium content of at most 4000 ppm. The phosphate can be obtained by the precipitation of a rare earth element chloride at a constant pH lower than 2, and then calcining and redispersing the same in hot water. A phosphor obtained by calcining the phosphate at at least 1000° C. is also described. | 11-10-2011 |
20110272635 | CERIUM AND/OR TERBIUM PHOSPHATE, OPTIONALLY WITH LANTHANUM, PHOSPHOR RESULTING FROM SAID PHOSPHATE AND METHODS FOR PREPARING SAME - A rare earth element phosphate (Ln) is described, wherein Ln is either: (1) at least one rare earth element selected from cerium and terbium, or (2) lanthanum in combination with at least one of the above two rare earth elements, and wherein the phosphate has a crystalline structure of the rhabdophane type or of the monazite type with a lithium content of at most 300 ppm. The phosphate is obtained by the precipitation of a rare earth element chloride at a constant pH lower than 2, and then calcining and redispersing the same in hot water. A phosphor obtained by calcining the phosphate at at least 1000° C. is also described. | 11-10-2011 |
20120025137 | CORE/SHELL LANTHANUM CERIUM TERBIUM PHOSPHATE, PHOSPHOR CONTAINING SAID PHOSPHATE, AND PREPARATION METHODS - A phosphate containing particles including a mineral core and a lanthanum cerium terbium phosphate shell uniformly coating the mineral core with a thickness greater than or equal to 300 nm is described. The particles can have a mean diameter between 3 μm and 6 μm and the lanthanum cerium terbium phosphate can have the following general formula (1): La | 02-02-2012 |
20120241672 | COMPOSITION COMPRISING A CERIUM AND/OR TERBIUM PHOSPHATE AND SODIUM, OF CORE/SHELL TYPE, PHOSPHOR RESULTING FROM THIS COMPOSITION AND METHODS FOR PREPARING SAME - The composition of the invention is of the type comprising particles formed by a mineral core and a shell that covers the mineral core uniformly, said shell being based on a phosphate of cerium and/or of terbium, optionally with lanthanum. The composition is characterized in that it contains sodium at a concentration of at most 7000 ppm. The phosphor of the invention is obtained by calcination of the composition at at least 1000 DEG C. | 09-27-2012 |
20130099161 | CORE/SHELL LANTHANUM CERIUM TERBIUM PHOSPHATE, AND PHOSPHOR HAVING IMPROVED THERMAL STABILITY AND INCLUDING SAID PHOSPHATE - A phosphate particle with a mean diameter of from 1.5 μm to 15 μm, which has an inorganic core and a shell that covers the inorganic core uniformly over a thickness of no less than 300 nm, is described. The shell can have a lanthanum cerium terbium phosphate of formula La | 04-25-2013 |
20130187093 | CORE-SHELL PHOSPHOR PRODUCED BY HEAT-TREATING A PRECURSOR IN THE PRESENCE OF LITHIUM TETRABORATE - A method of producing a phosphor is described in which a precursor including particles having an average diameter from 1.5 micrometers to 15 micrometers is heat-treated under a reducing atmosphere. The method can produce particles including a mineral core and a shell including a composite phosphate of lanthanum and/or cerium, optionally doped with terbium. The composite phosphate of lanthanum and/or cerium covers the mineral core uniformly over a thickness greater than or equal to 300 nm. The aforementioned heat treatment at a temperature of 1050° C. to 1150° C. and for a time period of 2 hours to 4 hours can involve the use of lithium tetraborate (Li | 07-25-2013 |
20130313479 | COMPOSITION CONTAINING A CORE-SHELL ALUMINATE, PHOSPHOR OBTAINED FROM SAID COMPOSITION, AND PREPARATION METHODS - A composition comprising an inorganic core and an aluminate shell is described. The aluminate can have the formula (1): | 11-28-2013 |
20140048743 | LUMINOPHORES AND CORE-SHELL LUMINOPHORE PRECURSORS - A novel type of green luminophore containing mixed rare-earth phosphates is produced from precursor particles having a mean diameter ranging from 1.5 to 15 microns; such particles have an inorganic core and a shell of a mixed lanthanum and/or cerium phosphate, optionally doped with terbium, evenly covering the inorganic core with a thickness greater than or equal to 300 nm. | 02-20-2014 |
20140295153 | PHOSPHOR BASED ON A LANTHANUM CERIUM TERBIUM PHOSPHATE WITH STABILIZED BRIGHTNESS, PREPARATION PROCESS AND USE IN A LUMINESCENT DEVICE - The phosphor of the invention is based on a lanthunum cerium terbium phosphate, and it is characterized in that the phosphate consists of particles having a mean size of at most 4 μm, in that it has a lithium content of at most 30 ppm, a boton content of at most 30 ppm and in that it has a variation of brightness between the brightness measured on the phosphor at 25° C. and that measured on the same phosphor at 200° C. of at most 4%. | 10-02-2014 |