Liquid suspension of cerium oxide particles

Patent metadata

Field	Value
Publication number	US-11028288-B2
Application number	US-201916424031-A
Country	US
Kind code	B2
Filing date	May 28, 2019
Priority date	Dec 16, 2013
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

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.

First claim

The invention claimed is:

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.

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

3. 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.

4. The process according to claim 1 , wherein the amount of nitrate ions, expressed by the NO 3 − /Ce 3 + molar ratio, is between 1/6 and 5/1.

5. 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.

Assignees

• Rhodia Operations

Inventors

• Suda Eisaku
• Yuasa Manabu
• Sekimoto Takao

Classifications

• C01P2004/62

  Submicrometer sized, i.e. from 0.1-1 micrometer · CPC title

• C01F17/235

  Cerium oxides or hydroxides · CPC title

• C09G1/02 Primary

  containing abrasives or grinding agents {(abrasives as such C09K3/14; polishing of semi-conductors H10P52/40)} · CPC title

• C01F17/206

  oxide or hydroxide being the only anion · CPC title

• C09K3/1472

  Non-aqueous liquid suspensions · CPC title