# US 11,028,288 B2 · Liquid suspension of cerium oxide particles

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- Number: US 11,028,288 B2
- Document ID: US11028288B2
- Status: Granted
- Kind: B2
- Application number: 16/424,031
- Filed: 2019-05-28
- Published: 2020-03-19
- Granted: 2021-06-08
- Earliest claimed: 2013-12-16
- Assignees: Rhodia Operations
- Applicants: Rhodia Operations
- Inventors: Eisaku Suda; Manabu Yuasa; Takao Sekimoto
- Web page: https://patentgrep.com/patent/US11028288B2

## CPC

- C09G 1/02: containing abrasives or grinding agents {(abrasives as such C09K3/14; polishing of semi-conductors H10P52/40)}
- C01F 17/206: oxide or hydroxide being the only anion
- C01F 17/235: Cerium oxides or hydroxides
- C09K 3/1409: {Abrasive particles per se (preparation of diamond C01B32/25)}
- C09K 3/1436: {Composite particles, e.g. coated particles}
- C09K 3/1463: {Aqueous liquid suspensions}
- C09K 3/1472: {Non-aqueous liquid suspensions}
- B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites
- B82Y 40/00: Manufacture or treatment of nanostructures
- C01P 2004/50: Agglomerated particles
- C01P 2004/51: Particles with a specific particle size distribution
- C01P 2004/62: Submicrometer sized, i.e. from 0.1-1 micrometer
- C01P 2006/12: Surface area
- C01P 2006/22: Rheological behaviour as dispersion, e.g. viscosity, sedimentation stability
- C09G: POLISHING COMPOSITIONS (French polish C09F11/00); SKI WAXES
- 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})
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- 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

## Abstract

The present invention relates to a suspension of cerium oxide particles in a liquid phase, in which said particles comprise secondary particles comprising primary particles, and a process for preparing said liquid suspension in which the cerium IV/total cerium molar ratio before precipitation is comprised between 1/10000 and 1/500000 and that the thermal treatment is being carried out under an inert atmosphere.

## Claims

### Claim 1

A process for preparing a cerium oxide suspension, the process comprising:
(a) treating a solution comprising at least a cerium III salt, a cerium IV salt and a base, under an inert atmosphere, to form a precipitate in solution; wherein the cerium IV/total cerium molar ratio before precipitation is between 1/10000 and 1/500000;
(b) thermally treating the precipitate in solution under an inert atmosphere to form a thermally treated medium, wherein at least one of steps (a) or (b) is carried out in the presence of nitrate ions; and
(c) acidifying and washing the thermally treated medium, whereby the suspension is obtained.

### Claim 2 (depends on 1)

The process according to claim 1, wherein the cerium IV/total cerium molar ratio before precipitation is between 1/50000 and 1/300000.

### Claim 3 (depends on 1)

The process according to claim 1, wherein the cerium IV is at least one compound selected from the group consisting of: cerium IV nitrate, cerium ammonium nitrate, cerium ammonium sulfate, and cerium IV sulfate.

### Claim 4 (depends on 1)

The process according to claim 1, wherein the amount of nitrate ions, expressed by the NO3−/Ce3+ molar ratio, is between 1/6 and 5/1.

### Claim 5 (depends on 1)

The process according to claim 1, wherein step a) comprises treating a solution of a cerium III salt with a solution comprising a base and a cerium IV salt, under an inert atmosphere, to form a precipitate in solution.