Patent ID: 11912583
Assignee: SHIN-ETSU CHEMICAL CO., LTD.
Field: Materials, metallurgy (Chemistry)
Classification: CPC C | IPC C

Claim 8:
9. A slurry comprising a dispersion medium and rare earth oxide particles wherein the particles have a volume basis median particle size D50 of up to 50 nm, and the rare earth oxide particles are prepared by the steps of:
heating an aqueous solution containing rare earth metal ions and urea to form rare earth compound particles by reaction of a hydrolysis product of urea, and the rare earth metal ions,
separating a precipitate of the rare earth compound particles generated in the heating step from the solution by a solid-liquid separation,
firing the obtained solid component in an atmosphere containing oxygen to form a rare earth oxide,
wherein in the heating step, heating the aqueous solution into which an acetylene glycol-ethylene oxide adduct is added, and
wherein the rare earth comprise at least one selected from the group consisting of Y, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu.