Cerium oxide abrasive, method for producing cerium oxide abrasive, and polishing method

Patent metadata

Field	Value
Publication number	US-10047262-B2
Application number	US-201414901229-A
Country	US
Kind code	B2
Filing date	Jun 18, 2014
Priority date	Jun 27, 2013
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

An object of the present invention is to provide a cerium oxide abrasive material containing cerium oxide abrasive particles prepared by a synthetic method using an aqueous solution of a salt of a rare earth element and a precipitant, the cerium oxide abrasive particles having a spherical shape and high polishing performance (polishing rate and polishing precision of the polished surface), a method for producing the cerium oxide abrasive material, and a polishing method. The cerium oxide abrasive material according to the present invention comprises spherical cerium oxide abrasive particles prepared by a synthetic method using an aqueous solution of a salt of a rare earth element and a precipitant, wherein the cerium oxide abrasive particles have a spherical shape having an average aspect ratio within the range of 1.00 to 1.15.

First claim

The invention claimed is:

1. A cerium oxide abrasive material comprising spherical cerium oxide abrasive particles prepared by a synthetic method using an aqueous solution of a salt of a rare earth element and a precipitant,
wherein the cerium oxide abrasive particles have a spherical shape having an average aspect ratio within the range of 1.00 to 1.15; and
the cerium oxide abrasive particles each have a core-shell structure comprising:
a core containing at least one of Y, Ti, Sr, Ba, Sm, Eu, Gd, and Tb; and
a shell containing Ce and at least one of Y, Ti, Sr, Ba, Sm, Eu, Gd, and Tb.

2. The cerium oxide abrasive material according to claim 1 , wherein an average content of trivalent cerium is within the range of 5 to 40 mol % of the total cerium content in a surface region ranging from the outermost layer of each cerium oxide abrasive particle to a depth of 10 nm toward a center of the particle.

3. The cerium oxide abrasive material according to claim 1 , wherein a particle size D 50 (nm) determined from a cumulative particle size distribution curve of the cerium oxide abrasive particles is within the range of 50 to 500 nm.

4. The cerium oxide abrasive material according to claim 1 , wherein a particle size D 10 (nm) determined from a cumulative particle size distribution curve of the cerium oxide abrasive particles is within the range of 0.70 to 0.95 times the particle size D 50 (nm).

5. The cerium oxide abrasive material according to claim 1 , wherein a particle size D 90 (nm) determined from a cumulative particle size distribution curve of the cerium oxide abrasive particles is within the range of 1.10 to 1.35 times the particle size D 50 (nm).

6. The cerium oxide abrasive material according to claim 1 , wherein an average content of cerium in the cerium oxide abrasive particles is 81 mol % or more of the total content of all the rare earth elements in the particles.

7. The cerium oxide abrasive material according to claim 1 , wherein a half width of a main peak in a powder X ray diffraction pattern of the cerium oxide abrasive particles is within the range of 0.17 to 0.25°.

8. The cerium oxide abrasive material according to claim 7 , wherein the cerium oxide abrasive particles have a spherical shape having an average aspect ratio within the range of 1.00 to 1.02.

9. A method for producing a cerium oxide abrasive material, wherein the cerium oxide abrasive material according to claim 1 is produced through steps 1 to 4,
Step 1: mixing an aqueous solution of a salt of a rare earth element containing cerium with a precipitant solution to prepare a reaction solution,
Step 2: heating the reaction solution to prepare an abrasive particle precursor,
Step 3: separating the abrasive particle precursor from the reaction solution, and
Step 4: firing the separated abrasive particle precursor to form cerium oxide abrasive particles.

10. The method for producing a cerium oxide abrasive material according to claim 9 , wherein a firing temperature in the firing step is within the range of 450 to 900° C.

11. The method for producing the cerium oxide abrasive material according to claim 7 , wherein the abrasive particles are prepared by firing at least a cerium oxide particle precursor mainly composed of cerium oxide precipitated in a solution, and the firing treatment is performed at a firing temperature within the range of 700 to 1000° C.

12. The method for producing a cerium oxide abrasive material according to claim 11 , wherein a firing apparatus for firing the cerium oxide particle precursor in the firing step is a roller hearth kiln or a rotary kiln.

13. The method for producing a cerium oxide abrasive material according to claim 9 , wherein the pH of the reaction solution is controlled within the range of 4.5 to 7.0 in the step 2.

14. The method for producing a cerium oxide abrasive material according to claim 13 , wherein urea is added to the reaction solution as a pH adjuster for the reaction solution.

15. The method for producing a cerium oxide abrasive material according to claim 13 , wherein an aqueous acidic or alkaline solution is added to the reaction solution as pH adjusters for the reaction solution.

16. The method for producing a cerium oxide abrasive material according to claim 13 , wherein the pH of the reaction solution is controlled within the range of 5.0 to 6.5 in the step of preparing the abrasive particle precursor.

Assignees

• Konica Minolta Inc

Inventors

• Mizoguchi Keisuke
• Maezawa Akihiro
• Takahashi Atsushi
• Ito Natsuki
• Hirayama Natsumi
• Wakamatsu Hideaki

Classifications

• C09G1/02

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

• B24B37/044

  characterised by the composition of the lapping agent · CPC title

• C09K3/1436

  Composite particles, e.g. coated particles · CPC title

• C09K3/1445

  the coating consisting exclusively of metals · CPC title

• C01P2004/64

  Nanometer sized, i.e. from 1-100 nanometer · CPC title