Core-shell-type cerium oxide microparticle, dispersion solution comprising the microparticle, and process for production of the microparticle or dispersion solution

摘要

An object of the present invention is to provide a core-shell-type cerium oxide microparticle, a dispersion solution comprising the microparticle, and a process for production of the microparticle or dispersion solution, and to achieve the object, the present invention provides a core-shell-type cerium oxide microparticle which has an average particle diameter of 30 to 200 nm and a coefficient of variation therein no greater than 0.25, and in which the secondary particle forming the core portion is spherical in shape and a polymer is attached to its surface, a dispersion solution of this cerium oxide microparticle and a dry powder from the cerium oxide microparticle dispersion solution, and a process of producing a core-shell-type cerium oxide microparticle or a dispersion solution thereof, which comprises the steps of: mixing a cerium salt and a polymer in an organic solvent to obtain a mixture; and heating this mixture under reflux at a prescribed temperature to precipitate core-shell-type cerium oxide microparticles, wherein the cerium salt is cerium nitrate and the particle diameter of the microparticles is adjusted using the molecular weight of the polymer.

主权项

1. A process of producing core-shell cerium oxide microparticles having a cross-linked polymer layer on a spherical aggregation of primary nanosize particles, comprising:
mixing a cerium (III) nitrate hydrate and a polymer of polyvinylpyrrolidone (PVP), which has an average molecular weight of 4,000 to 20,000 in terms of polyethylene glycol, in a high-boiling organic solvent to obtain a mixture having a concentration of the polymer of 80 kg/m3 to 120 kg/m3; and heating the mixture under reflux at a temperature ranging from 110° C. to 190° C. to give the core-shell cerium oxide microparticles.