Abrasive particles and production method thereof
AssigneeKonica Minolta, Inc.
InventorsAtsushi Takahashi, Natsuki Ito, Akihiro Maezawa
Life of this patent
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Abstract
In order to use less cerium oxide and achieve higher durability and polishing speeds, these abrasive particles used in an abrasive have: a shell layer (3) which is the outermost shell layer of the abrasive particles and is formed with cerium oxide as the main component; and a middle layer (2) which contains cerium oxide and an oxide of at least one element selected from Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, In, Sn, Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, W, Bi, Th, and the alkali earth metals, and which is formed closer to the center of the abrasive particles than the shell layer (3).
Claims8
An abrasive particle to be used as an abrasive material, comprising:
- a shell layer being an outermost layer of the abrasive particle and mainly composed of cerium oxide;
- an intermediate layer containing cerium oxide and an oxide of at least one element selected from the group consisting of Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, In, Sn, Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, W, Bi, Th, and alkali earth metals and formed on an inner side of the shell layer of the abrasive particle;
- and
- a core layer formed on an inner side of the intermediate layer of the abrasive particle and including a center of the abrasive particle,
- wherein the shell layer covers the entire intermediate layer, and the core layer is mainly composed of an oxide of at least one element selected from the group consisting of Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, In, Sn, Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, W, Bi, Th, and alkali earth metals,
- wherein the intermediate layer contains the cerium oxide and the oxide of at least one element selected from the group consisting of Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, In, Sn, Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, W, Bi, Th, and alkali earth metals at a variation within a range of ±5 mol %.
A method of producing abrasive particles, comprising:
- forming a core layer mainly composed of a salt of at least one element selected from the group consisting of Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, In, Sn, Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, W, Bi, Th, and alkali earth metals through formation of the salt;
- forming an intermediate layer containing a Ce salt and a salt of at least one element selected from the group consisting of Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, In, Sn, Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, W, Bi, Th, and alkali earth metals on an outer surface of the core layer by adding an aqueous solution containing at least one element selected from the group consisting of Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, In, Sn, Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, W, Bi, Th, and alkali earth metals and an aqueous solution containing a Ce salt to a first dispersion containing the dispersed particles of the salt of the element formed in the core layer-forming step;
- forming a shell layer mainly composed of a Ce salt on an outer surface of the intermediate layer by adding an aqueous solution containing a Ce salt to a second dispersion containing the dispersed particles provided with the intermediate layer of the salts formed in the intermediate layer-forming step;
- separating the solid being an abrasive material precursor from a third dispersion prepared in the shell layer-forming step;
- and
- firing the abrasive material precursor prepared in the separation step in the air or in an oxidizing atmosphere,
- wherein the intermediate layer-forming step uses the aqueous solution containing a Ce salt and the aqueous solution containing a salt of at least one element selected from the group consisting of Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, In, Sn, Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, W, Bi, Th, and alkali earth metals such that the intermediate layer contains the Ce salt and the salt of at least one element selected from the group consisting of Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, In, Sn, Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, W, Bi, Th, and alkali earth metals at a variation within a range of ±5 mol %.
Dependencies are inferred from the claim text.