# US 5,344,588 A · Cerium (IV) compound > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,344,588 A - Document ID: US5344588A - Status: Granted - Kind: A - Application number: 07/750,750 - Filed: 1991-08-21 - Granted: 1994-09-06 - Earliest claimed: 1985-06-20 - Assignees: Rhone-Poulenc Specialites Chimiques - Inventors: Jean-Yves Chane-Ching - Web page: https://patentgrep.com/patent/US5344588A ## CPC - C01F 17/30: Compounds containing rare earth metals and at least one element other than a rare earth metal, oxygen or hydrogen, e.g. La4S3Br6 (C01F17/247 - C01F17/294 take precedence) - B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites - C01F 17/235: Cerium oxides or hydroxides - C01P 2002/60: Compounds characterised by their crystallite size - C01P 2002/88: by thermal analysis data, e.g. TGA, DTA, DSC - C01P 2004/64: Nanometer sized, i.e. from 1-100 nanometer - Y10S 516/922: Colloid systems having specified particle size, range, or distribution, e.g. bimodal particle distribution - Y10S 516/928: Mixing combined with non-mixing operation or step, successively or simultaneously, e.g. heating, cooling, ph change, ageing, milling - C01F: COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts of peroxyacids C01B15/00; sulfides or polysulfides of magnesium, calcium, strontium, or barium C01B17/42; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds other than ammonia or cyanogen containing nitrogen and non-metals and optionally metals C01B21/082; amides or imides of silicon C01B21/087}; metal {imides or} amides C01B21/092, {C01B21/0923}; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanic acid C01C3/14; salts of cyanamide C01C3/16; thiocyanates C01C3/20; {double sulfates of magnesium with sodium or potassium C01D5/12; with other alkali metals C01D15/00, C01D17/00}) - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract A novel cerium (IV) compound, well adopted for the production of aqueous colloidal sols therefrom, has the general formula (I): Ce (Me).sub.x (OH).sub.y (NO.sub.3).sub.z (I) wherein M is an alkali metal an ammonium radical; x ranges from 0.01 to 0.2; y is a number such that y=4-z+x; and z ranges from 0.4 to 0.7. ## Claims ### Claim 1 An aqueously dispersible cerium (IV) material having the general formula (I): Ce (M).sub.x (OH).sub.y (NO.sub.3).sub.z (I) wherein M is an alkali metal or an ammonium radical; x ranges from 0.01 to 0.2; y is a number such that y=4-z+x; and z ranges from 0.4 to 0.7. ### Claim 2 (depends on 1) The cerium (IV) material as defined by claim 1, exhibiting an exothermic peak of 250.degree. C. to 300.degree. C. by differential thermal analysis at a temperature rise of 300.degree. C. per hour. ### Claim 3 (depends on 1) The cerium (IV) material as defined by claim 1, comprising a CeO.sub.2 type crystalline phase with lattice parameters of 5.42 .ANG. to 5.44 .ANG. and having a degree of crystallinity ranging from 30 to 70%. ### Claim 4 (depends on 3) The cerium (IV) material as defined by claim 3, having a degree of crystallinity ranging from 40 to 60%. ### Claim 5 (depends on 3) The cerium (IV) material as defined by claim 3, the size of the crystallites thereof being less than about 60 .ANG.. ### Claim 6 An aqueous colloidal dispersion of cerium (IV) material comprising an aqueously dispersible cerium (IV) material having the general formula (I): Ce (M).sub.x (OH).sub.y (NO.sub.3).sub.z (I) wherein M is an alkali metal or an ammonium radical; x ranges from 0.01 to 0.2; y is a number such that y=4-z+x; and z ranges from 0.4 to 0.7. ### Claim 7 An aqueous colloidal dispersion containing a cerium (IV) precipitate material produced by (I) reacting an aqueous solution of a cerium (IV) salt with a base reactant to form a colloidal dispersion of a cerium (IV) material in water, said colloidal dispersion having a neutralization ratio ranging from at least 0.01 to not more than 3, and (II) heat treating said colloidal dispersion to precipitate the cerium (IV) material therefrom, wherein said cerium (IV) salt is added in an amount sufficient to create a cerium (IV) concentration of from 0.01 to 2 moles/liter. ### Claim 8 (depends on 7) An aqueous colloidal dispersion as defined by claim 7, having a cerium (IV) concentration of from 0.3 to 0.8 mole/liter. ### Claim 9 (depends on 7) An aqueous colloidal dispersion as defined by claim 7, the hydrodynamic diameter of the colloidal particulates of which ranging from 40 to 300 A. ### Claim 10 (depends on 7) An aqueous colloidal dispersion as defined by claim 7, from 20 to 70% of the cerium (IV) content of which comprising colloidal particulates. ### Claim 11 (depends on 1) A sol comprising a suspension, in water, of colloidal particulates of the cerium (IV) material as defined by claim 1. ### Claim 12 (depends on 11) The aqueous sol as defined by claim 11, the hydrodynamic diameter of the colloidal particulates of which ranging from 40 to 3000 .ANG.. ### Claim 13 (depends on 12) The aqueous sol as defined by claim 12, the hydrodynamic diameter of the colloidal particulates of which ranging from 40 to 600 .ANG.. ### Claim 14 (depends on 12) The aqueous sol as defined by claim 12, the hydrodynamic diameter of the colloidal particulates of which ranging from 150 to 3000 .ANG.. ### Claim 15 (depends on 12) The aqueous sol as defined by claim 12, the hydrodynamic diameter of the colloidal particulates of which ranging from 40 to 100 .ANG.. ### Claim 16 (depends on 12) The aqueous sol as defined by claim 12, the hydrodynamic diameter of the colloidal particulates of which ranging from 150 to 500 .ANG.. ### Claim 17 (depends on 12) The aqueous sol as defined by claim 12, wherein the concentration of the cerium (IV) material therein, expressed as CeO.sub.2, is up to 2 moles/liter. ### Claim 18 (depends on 12) The aqueous sol as defined by claim 12, having a pH ranging from about 1 to 2.5. ### Claim 19 (depends on 18) The aqueous sol as defined by claim 18, having a pH of about 1. ### Claim 20 (depends on 12) The aqueous sol as defined by claim 12, at least 95% of the cerium (IV) content of which comprising colloidal particulates. ### Claim 21 (depends on 20) The aqueous sol as defined by claim 20, at least 99% of the cerium (IV) content of which comprising colloidal particulates. ### Claim 22 (depends on 12) The aqueous sol as defined by claim 12, the size distribution of said colloidal particulates being essentially uniform. ### Claim 23 (depends on 6) An aqueous colloidal dispersion of the cerium (IV) material as defined by claim 6, wherein at least 95% of the cerium (IV) content in the dispersion is in the form of colloidal particulates. ### Claim 24 (depends on 6) An aqueous colloidal dispersion of the cerium (IV) material as defined by claim 6, wherein the concentration of the cerium (IV) material, expressed as CeO.sub.2, is not more than 2 moles per liter. ### Claim 25 An aqueous colloidal dispersion of a cerium (IV) material combined with a base, said cerium (IV) material having the general formula (I): Ce (M).sub.x (OH).sub.y (NO.sub.3).sub.z (I) wherein M is an alkali metal or an ammonium radical; x ranges from 0.01 to 0.2; y is the number such that y=4-z+x; and z ranges from 0.4 to 0.7, said base being present in an amount such that, the colloidal particulates have a hydrodynamic diameter ranging from 150 to 3000 .ANG.. ### Claim 26 (depends on 25) An aqueous colloidal dispersion according to claim 25, said base being present in an amount such that the pH is about 2.5. ### Claim 27 (depends on 6) An aqueous colloidal dispersion according to claim 6, including colloid particulates having a hydrodynamic diameter ranging from 40 to 100 .ANG.. ### Claim 28 (depends on 27) An aqueous colloidal dispersion according to claim 27 having a uniform size distribution of colloids. ### Claim 29 (depends on 27) An aqueous colloidal dispersion according to claim 27, wherein at least 99% of the cerium (IV) content in the dispersion is in the form of colloidal particulates. ### Claim 30 (depends on 25) An aqueous colloidal dispersion according to claim 25, including colloid particulates having a hydrodynamic diameter ranging from 150 to 400 .ANG.. ### Claim 31 A cerium (IV) precipitate material produced by (i) reacting an aqueous solution of a cerium (IV) salt with a base reactant to form a colloidal dispersion of a cerium (IV) material in water, said colloidal dispersion having a neutralization ratio ranging from at least 0.01 to not more than 3, and (ii) heat treating said colloidal dispersion to precipitate a cerium (IV) material therefrom. ### Claim 32 (depends on 31) A cerium (IV) precipitate material according to claim 31 wherein said heat treatment is conducted at a temperature ranging from about 80.degree. C. to about 300.degree. C.