Polishing slurry and polishing material
A polishing slurry according to the present invention contains: abrasive grains made of a metal oxide; a permanganate; and an inorganic compound other than the permanganate. The inorganic compound is such that a solution that is obtained by adding the inorganic compound to a 1.0 mass % aqueous solution of the permanganate so that the inorganic compound accounts for 1.0 mass % of the resultant aqueous solution has an oxidation-reduction potential higher than that of the 1.0 mass % aqueous solution of the permanganate. It is preferable that the inorganic compound be contained in an amount of 0.7 parts by mass or more and 150 parts by mass or less relative to 100 parts by mass of the permanganate. It is also preferable that the abrasive grains made of a metal oxide be manganese oxide particles.
1. A polishing slurry comprising:
abrasive grains made of manganese oxide particles, wherein an amount of the abrasive grains in the polishing slurry is 1 mass % or more and 10 mass % or less;
a permanganate; and
an inorganic compound, wherein the inorganic compound includes one or more of cerium nitrate (Ce(NO 3 ) 3 ) and cerium sulfate (IV) (Ce(SO 4 ) 2 ), wherein an amount of the one or more of cerium nitrate (Ce(NO 3 ) 3 ) and cerium sulfate (IV) (Ce(SO 4 ) 2 ) in the polishing slurry is 0.02 mass % or more and 1.0 mass % or less, and wherein the amount of the one or more of cerium nitrate (Ce(NO 3 ) 3 ) and cerium sulfate (IV) (Ce(SO 4 ) 2 ) is 1.0 parts by mass or more and 50 parts by mass or less relative to 100 parts by mass of the permanganate,
wherein the inorganic compound is such that a solution that is obtained by adding the inorganic compound to a 1.0 mass % aqueous solution of the permanganate so that the inorganic compound accounts for 1.0 mass % of the resultant aqueous solution has an oxidation-reduction potential higher than that of the 1.0 mass % aqueous solution of the permanganate, and
wherein the polishing slurry has an oxidation-reduction potential of 25° C. of 700 mV or more and 1300 mV or less.
2. The polishing slurry as set forth in claim 1 , wherein the polishing slurry has a pH at 25° C. of 1.0 or more and 8.0 or less before polishing.
3. The polishing slurry as set forth in claim 1 , wherein the polishing slurry is used in polishing that does not use fixed abrasive grains.
4. The polishing slurry as set forth in claim 1 , wherein the inorganic compound further includes one or more transition metal chlorides including one or more of rare earth elements selected from the group consisting of: scandium chloride (ScCl 3 ), yttrium chloride (YCl 3 ), lanthanum chloride (LaCl 3 ), cerium chloride (CeCl 3 ), praseodymium chloride (PrCl 3 ), neodymium chloride (NdCl 3 ), samarium chloride (SmCl 3 ), europium chloride (EuCl 3 ), gadolinium chloride (GdCl 3 ), terbium chloride (TbCl 3 ), dysprosium chloride (DyCl 3 ), holmium chloride (HoCl 3 ), erbium chloride (ErCl 3 ), thulium chloride (TmCl 3 ), ytterbium chloride (YbCl 3 ), lutetium chloride (LuCl 3 ), and combinations thereof.
5. The polishing slurry as set forth in claim 1 , wherein the inorganic compound further includes one or more transition metal sulfates including one or more of rare earth elements selected from the group consisting of: scandium sulfate (Sc(SO 4 ) 3 ), yttrium sulfate (Y(SO 4 ) 3 ), lanthanum sulfate (La(SO 4 ) 3 ), praseodymium sulfate (Pr(SO 4 ) 3 ), neodymium sulfate (Nd(SO 4 ) 3 ), samarium sulfate (Sm(SO 4 ) 3 ), europium sulfate (Eu(SO 4 ) 3 ), gadolinium sulfate (Gd(SO 4 ) 3 ), terbium sulfate (Tb(SO 4 ) 3 ), dysprosium sulfate (Dy(SO 4 ) 3 ), holmium sulfate (Ho(SO 4 ) 3 ), erbium sulfate (Er(SO 4 ) 3 ), thulium sulfate (Tm(SO 4 ) 3 ), ytterbium sulfate (Yb(SO 4 ) 3 ), lutetium sulfate (Lu(SO 4 ) 3 ), and combinations thereof.
6. The polishing slurry as set forth in claim 1 , wherein the content of the manganese oxide in the abrasive grains is 90 mass % or more.
7. A method for producing a polished article, comprising:
polishing a high-hardness material having a Mohs hardness of 8 or more as an article to be polished using:
a first polishing slurry including:
abrasive grains made of manganese oxide particles wherein an amount of the abrasive grains in the polishing slurry is 1 mass % or more and 10 mass % or less;
a first permanganate; and
a first inorganic compound, wherein the first inorganic compound includes one or more of cerium nitrate (Ce(NO 3 ) 3 ) and cerium sulfate (IV) (Ce(SO 4 ) 2 ), wherein an amount of the one or more of cerium nitrate (Ce(NO 3 ) 3 ) and cerium sulfate (IV) (Ce(SO 4 ) 2 ) in the polishing slurry is 0.02 mass % or more and 1.0 mass % or less, and wherein the amount of the one or more of cerium nitrate (Ce(NO 3 ) 3 ) and cerium sulfate (IV) (Ce(SO 4 ) 2 ) is 1.0 parts by mass or more and 50 parts by mass or less relative to 100 parts by mass of the permanganate,
wherein the first inorganic compound is such that a solution that is obtained by adding the first inorganic compound to a 1.0 mass % aqueous solution of the first permanganate so that the first inorganic compound accounts for 1.0 mass % of the resultant aqueous solution has an oxidation-reduction potential higher than that of the 1.0 mass % aqueous solution of the first permanganate, and
wherein the polishing slurry has an oxidation-reduction potential of 25° C. of 700 mV or more and 1300 mV or less.
8. The method for producing a polished article as set forth in claim 7 , wherein fixed abrasive grains are not used.