JP2014024155A - Abradant, abrasive composition, polishing method of crustaceous material, and manufacturing method of crustaceous material substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an abradant which easily increases polishing speed, an abrasive composition, a polishing method of a crustaceous material using the abrasive composition, and a manufacturing method of a crustaceous material substrate.SOLUTION: An abradant contains zirconium oxide particles. A specific surface area of the zirconium oxide particles is 15.0 m/g or less. The zirconium oxide particles have a particle size distribution in which a value X obtained by dividing a difference between D90 and D10 by D50 is 2.0 or less, when D10, D50, and D90 are particle diameters whose integrated mass is 10%, 50%, and 90% respectively from a small particle diameter side of an integrated particle size distribution on a mass basis. An abrasive composition contains the abradant and water, and a content of the abradant is 0.1 mass% or more. A polishing method of a crustaceous material uses the abrasive composition to polish the crustaceous material. A manufacturing method of a crustaceous material substrate includes a polishing process of polishing a substrate raw material consisting of the crustaceous material by using the abrasive composition.

Description

  The present invention relates to an abrasive and a polishing composition containing zirconium oxide particles. The present invention also relates to a method for polishing a hard and brittle material using the polishing composition and a method for producing a hard and brittle material substrate.

  For example, polishing compositions used for polishing substrates made of hard and brittle materials such as glass substrates for hard disks, glass substrates for liquid crystal display panels, synthetic quartz substrates for photomasks, etc., reduce the time required for polishing work. From the viewpoint, it is required that the substrate polishing rate (removal rate) be high.

  A polishing composition containing a cerium oxide-based abrasive is known as a polishing composition used for polishing a substrate made of a hard and brittle material (see Patent Document 1). However, in Japan today, rare earths such as cerium oxide depend on imports from abroad. For this reason, there is a concern that rare earth supplies may be insufficient due to the international situation, and price increases associated therewith. Therefore, development of an abrasive using an alternative material to replace rare earth is desired.

  On the other hand, Patent Document 2 discloses a polishing composition containing zirconium oxide fine particles and a polishing accelerator as a polishing composition used for polishing an aluminum substrate for a magnetic disk.

JP 2010-16064 A JP-A-10-121034

  An object of the present invention is to provide an abrasive and a polishing composition that can easily increase the polishing rate. Another object of the present invention is to provide a method for polishing a hard and brittle material and a method for producing a hard and brittle material substrate using the polishing composition.

In order to achieve the above object, in one embodiment of the present invention, there is provided an abrasive containing zirconium oxide particles, wherein the specific surface area of the zirconium oxide particles is 15.0 m ² / g or less, and the zirconium oxide The difference between D90 and D10 is defined as D10, D50, and D90 when the particle diameters at which the accumulated mass from the small particle diameter side of the accumulated particle size distribution on the mass basis is 10%, 50%, and 90%, respectively. An abrasive having a particle size distribution with a value divided by D50 of 2.0 or less is provided.

In another aspect of the present invention, there is provided a polishing composition containing the abrasive and water, wherein the polishing composition has a content of 0.1% by mass or more.
In another aspect of the present invention, there is provided a method for polishing a hard and brittle material, wherein the hard and brittle material is polished using the polishing composition.

  In another aspect of the present invention, there is provided a method for producing a hard and brittle material substrate including a polishing step of polishing a substrate material made of a hard and brittle material using the polishing composition.

  According to the present invention, an abrasive and a polishing composition that can easily increase the polishing rate are provided. Further, a method for polishing a hard and brittle material using the polishing composition and a method for producing a hard and brittle material substrate are provided.

Hereinafter, an embodiment of the present invention will be described.
The polishing composition of this embodiment contains an abrasive and water. The abrasive contains zirconium oxide particles. The polishing composition can be suitably used for polishing hard and brittle materials such as sapphire, silicon nitride, silicon carbide, silicon oxide, glass, gallium nitride, gallium arsenide, indium arsenide, and indium phosphide.

  The zirconium oxide particles contained in the abrasive may be made of crystalline zirconia such as cubic, tetragonal or monoclinic, or may be made of amorphous zirconia. . As the abrasive, it is preferable to use zirconium oxide particles made of tetragonal or monoclinic zirconia.

  The zirconium oxide particles may contain impurities. However, the purity of the zirconium oxide particles is preferably as high as possible. Specifically, the purity of the zirconium oxide particles is preferably 99% by mass or more, more preferably 99.5% by mass or more, and further preferably 99.8% by mass or more. When the purity of the zirconium oxide particles is 99% by mass or more, the polishing rate of the hard and brittle material by the polishing composition is improved by the increase in purity. In this respect, if the purity of the zirconium oxide particles is 99% by mass or more, preferably 99.5% by mass or more, more preferably 99.8% by mass or more, the polishing rate of the hard and brittle material by the polishing composition is practically used. It becomes easy to improve to a particularly suitable level. The purity of the zirconium oxide particles can be calculated from the measured value of the total amount of zirconium oxide and hafnium oxide by a fluorescent X-ray analyzer such as XRF-1800 manufactured by Shimadzu Corporation.

  Examples of the impurities contained in the zirconium oxide particles include calcium, magnesium, hafnium, yttrium, silicon, aluminum, iron, copper, chromium, titanium, and oxides thereof. However, the amount of impurities contained in the zirconium oxide particles is preferably small. For example, the content of silicon oxide in the zirconium oxide particles is preferably 1% by mass or less, more preferably 0.5% by mass or less, and still more preferably 0.2% by mass or less. The contents of aluminum oxide and iron oxide in the zirconium oxide particles are each preferably 0.1% by mass or less. In addition, content of impurities, such as a silicon oxide, aluminum oxide, and an iron oxide, can be computed from the measured value by an ICP emission-spectral-analysis apparatus, for example.

The specific surface area of the zirconium oxide particles is 15.0 m ² / g or less. The specific surface area of the zirconium oxide particles is preferably 13.0 m ² / g or less. By setting the specific surface area of the zirconium oxide particles in the range of 15.0 m ² / g or less, it becomes easy to improve the polishing rate of the hard and brittle material by the polishing composition to a practically suitable level. Moreover, it is preferable that the specific surface area of a zirconium oxide particle is 0.5 m < ² > / g or more, More preferably, it is 1.0 m < ² > / g or more, More preferably, it is 2.0 m < ² > / g or more. Note that the specific surface area of the abrasive can be measured by a specific surface area measurement apparatus using a nitrogen adsorption method such as FlowSorbII2300 manufactured by Shimadzu Corporation.

  Zirconium oxide particles have a specific particle size distribution. The particle size distribution of the zirconium oxide particles is D90 when the particle sizes at which the integrated mass from the small particle size side of the integrated particle size distribution on the mass basis is 10%, 50%, and 90% are D10, D50, and D90, respectively. And D10 is represented by a value X ([D90−D10] / D50) obtained by dividing D50 by D50. A value X obtained by dividing the difference between D90 and D10 by D50 is 2.0 or less.

  Here, the closer the value X is to 0, the smaller the particle size variation, and the larger the value X, the larger the particle size variation. By increasing the particle size distribution of the zirconium oxide particles so that the value X is 2.0 or less, the polishing rate of the hard and brittle material by the polishing composition is improved to a practically suitable level. Becomes easy. In addition, each value of said D10, D50, D90 can be calculated | required with a laser diffraction / scattering type particle size distribution measuring apparatus, for example.

  D50, which is the particle diameter at which the cumulative mass is 50%, reflects the average particle diameter (median diameter) of the zirconium oxide particles. D50 is preferably 4 μm or less, more preferably 2 μm or less, and even more preferably 1 μm or less. Further, D50 is preferably 0.2 μm or more, more preferably 0.3 μm or more, and further preferably 0.5 μm or more.

  D10, which is the particle diameter at which the cumulative mass is 10%, indicates the amount of fine particles. Specifically, the smaller the D10, the greater the amount of fine particles. D10 is preferably 2.5 μm or less, more preferably 1 μm or less, and even more preferably 0.6 μm or less. Further, D10 is preferably 0.1 μm or more, more preferably 0.2 μm or more, and further preferably 0.3 μm or more.

  D90, which is the particle diameter at which the cumulative mass is 90%, indicates the amount of coarse particles. Specifically, the larger the D90, the greater the amount of coarse particles. D90 is preferably 5 μm or less, more preferably 3 μm or less, and even more preferably 2 μm or less. Further, D90 is preferably 0.5 μm or more, more preferably 0.8 μm or more, and further preferably 1 μm or more.

  The method for producing zirconium oxide particles is not particularly limited. For example, zirconium oxide particles produced by either a wet method or a dry method can be used. In the wet method, zirconium-containing ores such as zircon and zircon sand are used as raw materials, and the zirconium compound obtained by melting, dissolving and refining it is hydrolyzed to obtain zirconium hydroxide, and then calcined and pulverized. Zirconium oxide particles are obtained. In the dry method, zirconium oxide particles are obtained by removing silicon oxide from zirconium-containing ores such as zircon and zircon sand by high-temperature treatment, or by pulverizing zirconium oxide ores such as badelite and then removing impurities. The high temperature treatment in the dry method is performed by heating the raw material ore to, for example, an arc furnace, usually at 2000 ° C. or higher, preferably about 2700 ° C. or higher. By this high temperature treatment, impurities such as silicon oxide are sublimated.

  The dry method can reduce the manufacturing cost than the wet method. Furthermore, the dry method is relatively easy to adjust the particle size and specific surface area of the resulting zirconium oxide particles by operations such as pulverization and classification than the wet method. Therefore, it is preferable that the zirconium oxide particles are produced by a dry method using badelite or the like as a raw material.

  In the method for producing zirconium oxide particles, the pulverization step of pulverizing the zirconium oxide particles is a step necessary for making the particle diameters of the obtained zirconium oxide particles small and removing impurities. Examples of the method of pulverizing the zirconium oxide particles include a method using a ball mill, a bead mill, a hammer mill or the like using media, and a method using a jet mill or the like that does not use media. Further, a wet method using a solvent and a dry method using no solvent can be given.

  In the pulverization step, the zirconium oxide particles collide with each other, or the zirconium oxide particles collide with the media, whereby the zirconium oxide particles are crushed or scraped to relatively reduce the particle diameter of the zirconium oxide particles. In the case of a grinding method using media such as a ball mill, efficient grinding can be expected due to the action of the media on the zirconium oxide particles. Therefore, it is preferable to perform a grinding method using media in the grinding step.

  The abrasive may further contain other particles in addition to the zirconium oxide particles. Examples of other particles include aluminum oxide particles, silicon dioxide particles, cerium oxide particles, titanium oxide particles, and zircon particles. For example, the abrasive may contain zirconium oxide particles and cerium oxide particles.

  When other particles are contained, the content of zirconium oxide particles in the abrasive is preferably 50% by mass or more, and more preferably 90% by mass or more. When silicon dioxide is contained as other particles, the content of silicon dioxide in the abrasive is preferably less than 10% by mass, more preferably less than 1% by mass. Moreover, when it contains cerium oxide as another particle | grain, it is preferable that content of cerium oxide in an abrasives is less than 40 mass%, More preferably, it is less than 9 mass%.

  Polishing composition contains the said abrasive | polishing material and water. The content of the abrasive in the polishing composition is preferably 0.1% by mass or more, more preferably 1% by mass or more, and further preferably 3% by mass or more. By increasing the content of the abrasive, the polishing rate of the hard and brittle material by the polishing composition is improved. In this respect, when the content of the abrasive in the polishing composition is 0.1% by mass or more, preferably 1% by mass or more, more preferably 3% by mass or more, polishing of the brittle material by the polishing composition It becomes easy to increase the speed to a particularly suitable level for practical use.

  It is preferable that pH of polishing composition is 3 or more. Moreover, it is preferable that pH of polishing composition is 12 or less. If the pH of the polishing composition is within the above range, it becomes easy to improve the polishing rate of the hard and brittle material by the polishing composition to a practically particularly suitable level.

  The pH of the polishing composition can be adjusted using various acids, bases, or salts thereof. Specifically, organic acids such as carboxylic acid, organic phosphonic acid and organic sulfonic acid, inorganic acids such as phosphoric acid, phosphorous acid, sulfuric acid, nitric acid, hydrochloric acid, boric acid and carbonic acid, tetramethylammonium hydroxide, trimethanolamine Organic bases such as monoethanolamine, inorganic bases such as potassium hydroxide, sodium hydroxide and ammonia, or salts thereof are preferably used.

  A cerium salt or a zirconium salt may be added to the polishing composition to promote polishing. Examples of the cerium salt include cerium ammonium nitrate, cerium nitrate, cerium chloride, cerium sulfate, and the like. Examples of the zirconium salt include zirconium oxychloride, zirconium nitrate, zirconium carbonate, zirconium hydroxide and the like. In addition, when cerium salt is added to the polishing composition, precipitation of cerium salt may occur depending on the type of alkali used for pH adjustment. If the cerium salt is precipitated, the effect of promoting polishing by adding the cerium salt may not be sufficiently obtained.

  A dispersing agent may be added to the polishing composition to improve dispersion stability. Examples of the dispersant include polyphosphates such as sodium hexametaphosphate and sodium pyrophosphate. Also, certain water-soluble polymers or salts thereof can be used as a dispersant. By adding the dispersant, the dispersion stability of the polishing composition is improved, and the supply of the polishing composition can be stabilized by making the slurry concentration uniform.

  Examples of the water-soluble polymer used as the dispersant include polycarboxylic acids, polycarboxylic acid salts, polysulfonic acid, polysulfonic acid salts, polyamines, polyamides, polyols, polysaccharides, and derivatives and copolymers thereof. Is mentioned. Specifically, polystyrene sulfonate, polyisoprene sulfonate, polyacrylate, polymaleic acid, polyitaconic acid, polyvinyl acetate, polyvinyl alcohol, polyglycerin, polyvinylpyrrolidone, a copolymer of isoprene sulfonic acid and acrylic acid , Polyvinylpyrrolidone polyacrylic acid copolymer, polyvinylpyrrolidone vinyl acetate copolymer, naphthalenesulfonic acid formalin condensate salt, diallylamine hydrochloride sulfur dioxide copolymer, carboxymethylcellulose, carboxymethylcellulose salt, hydroxyethylcellulose, hydroxypropylcellulose , Pullulan, chitosan, chitosan salts and the like.

  The content of the dispersant in the polishing composition is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, and further preferably 0.02% by mass or more. If the content of the dispersant is 0.001% by mass or more, it is easy to obtain a polishing composition having good dispersion stability.

  On the other hand, when an excessive amount of the dispersant is added, there is a tendency that the precipitate generated by the precipitation of the abrasive in the polishing composition during storage or transportation becomes strong. Therefore, when using the polishing composition, it is difficult to disperse the precipitate, that is, the redispersibility of the abrasive in the polishing composition may be reduced. Therefore, the content of the dispersant in the polishing composition is preferably 1% by mass or less, more preferably 0.2% by mass or less. When the content of the dispersant is 1% by mass or less, the storage stability of the polishing composition can be improved without reducing the redispersibility of the abrasive in the polishing composition.

Next, a method for preparing the polishing composition of the embodiment will be described.
The polishing composition is prepared by dispersing a polishing material containing zirconium oxide particles in water and adding a known additive as required. The mixing order of each component at the time of preparing polishing composition is arbitrary. For example, the polishing composition may be prepared by producing a concentrated composition containing an abrasive, water and additives, and diluting the concentrated composition with water. Further, the polishing composition may be prepared by dispersing an abrasive in an aqueous solution in which the additive is dissolved. Moreover, you may prepare polishing composition by mixing a powdery additive with a powdery abrasive and adding water to the mixture.

Next, the manufacturing method of the hard-brittle material board | substrate using the polishing composition of embodiment is demonstrated.
The manufacturing method of a hard and brittle material substrate includes a polishing step of polishing a substrate material made of a hard and brittle material using the polishing composition of the embodiment.

  Polishing of the substrate material using the polishing composition in the polishing step can be performed using the same apparatus and conditions as those normally used for polishing the substrate material. As the polishing apparatus, for example, a single-side polishing apparatus or a double-side polishing apparatus can be used. When using a single-side polishing machine, hold the substrate raw material using a carrier called a carrier, and press the surface plate with the polishing pad on one side of the substrate raw material, and then polish the substrate raw material against the substrate raw material. One side of the substrate raw material is polished by rotating the surface plate while supplying the material. When a double-side polishing apparatus is used, the substrate raw material is held using a holder called a carrier, and the upper and lower surface plates to which the polishing pads are respectively attached are pressed against both surfaces of the substrate raw material. Then, while supplying the polishing composition to the substrate material from above, the two surface plates are rotated in opposite directions to polish both surfaces of the substrate material. In the polishing step, the substrate raw material is polished by a physical action due to friction between the polishing pad and the polishing composition and the substrate raw material, and a chemical action that the polishing composition brings to the substrate raw material.

As the load during the polishing process, that is, the polishing load is increased, the polishing rate increases. The polishing load when polishing the substrate raw material using the polishing composition is not particularly limited, but is preferably 50 g or more and 1,000 g or less, more preferably 70 g or more and 800 g or less per 1 cm ^{2 of the} substrate surface area. . When the polishing load is within the above range, a practically sufficient polishing rate is obtained, and surface defects such as scratches generated on the substrate surface after polishing are suppressed.

  The linear velocity during the polishing process, that is, the polishing linear velocity, is generally affected by parameters such as the number of revolutions of the polishing pad, the number of carrier revolutions, the size of the substrate material, and the number of substrate materials. As the linear velocity increases, the frictional force applied to the substrate material increases, so that the substrate material is more strongly subjected to a mechanical polishing action. Further, since the frictional heat increases, the chemical polishing action by the polishing composition may be strengthened. However, if the linear velocity is too high, the polishing pad may not sufficiently rub against the substrate material, and the polishing rate may decrease. The linear velocity when the substrate material is polished using the polishing composition is not particularly limited, but is preferably 10 m / min or more and 150 m / min or less, more preferably 30 m / min or more and 100 m / min or less. When the linear velocity is within the above range, it is easy to obtain a practically sufficient polishing rate.

  The supply rate of the polishing composition to the polishing apparatus during the polishing step is appropriately set depending on the type of substrate raw material to be polished, the type of polishing apparatus, polishing conditions, and the like. However, it is preferable that the supply speed be sufficient to supply the polishing composition uniformly to the entire substrate material and polishing pad.

  The polishing pad used for polishing the substrate material using the polishing composition is not particularly limited in terms of its material, physical properties such as hardness and thickness. For example, any type such as a polyurethane type, a nonwoven fabric type, and a suede type may be used. The polishing pad may contain abrasive grains or may not contain abrasive grains. Further, the hardness and thickness of the polishing pad are not particularly limited.

  If the substrate material is a substrate that requires particularly high surface accuracy, such as a semiconductor substrate, a hard disk substrate, a liquid crystal display panel, or a synthetic quartz substrate for a photomask, a further fine polishing step may be performed after the polishing step. preferable. In the fine polishing step, the surface of the substrate material after the polishing step is further polished using a polishing composition containing a fine polishing abrasive, that is, a fine polishing composition. The pH of the fine polishing composition is preferably 1 or more and 4 or less, or 9 or more and 11 or less. The pH of the fine polishing composition can be adjusted using various acids, bases or salts thereof as in the polishing composition.

  The polishing material for fine polishing preferably has an average particle size of 0.15 μm or less, more preferably 0.10 μm or less, and still more preferably 0, from the viewpoint of reducing waviness, roughness, and defects on the substrate surface. 0.07 μm or less. From the viewpoint of improving the polishing rate, the average particle size of the fine polishing abrasive is preferably 0.01 μm or more, more preferably 0.02 μm or more. The average particle diameter of the abrasive for fine polishing can be measured by a dynamic light scattering method using, for example, Nanotrac UPA-UT151 manufactured by Nikkiso Co., Ltd.

By passing through the polishing step and, if necessary, the fine polishing step, the substrate raw material made of a hard and brittle material becomes a hard and brittle material substrate with improved surface accuracy.
According to the embodiment described in detail above, the following effects are exhibited.

(1) The polishing composition contains an abrasive containing zirconium oxide particles and water. The specific surface area of the zirconium oxide particles is 15.0 m ² / g or less. Zirconium oxide particles are D90 and D10, where D10, D50, and D90 are the particle diameters at which the integrated mass from the small particle diameter side of the integrated particle size distribution on the mass basis is 10%, 50%, and 90%, respectively. The particle size distribution has a value obtained by dividing the difference by D50 by 2.0 or less. This facilitates increasing the polishing rate.

  The zirconium oxide particles contained in the polishing composition are particularly excellent in the ability to polish hard and brittle materials. Therefore, it can be suitably used for polishing hard and brittle materials such as glass, ceramics, stone, and semiconductor materials. Among hard and brittle materials, it can be particularly preferably used for polishing sapphire, silicon nitride, silicon carbide, silicon oxide, glass, gallium nitride, gallium arsenide, indium arsenide, and indium phosphide. Furthermore, a hard and brittle material made of glass or oxide such as quartz glass, soda lime glass, aluminosilicate glass, borosilicate glass, aluminoborosilicate glass, alkali-free glass, crystallized glass, soda aluminosilicate glass, silicon oxide film, etc. Can be suitably used as an alternative to conventional abrasives and polishing compositions mainly composed of cerium oxide. Furthermore, by using the zirconium oxide particles, it becomes easy to increase the polishing rate of the hard and brittle material by the polishing composition.

(2) Preferably, the content of the abrasive in the polishing composition is 0.1% by mass or more. Thereby, it becomes easy to further increase the polishing rate.
(3) The method for polishing a hard and brittle material includes a step of polishing the hard and brittle material using the polishing composition described in the section (1) above. Thereby, a hard and brittle material with improved surface accuracy can be obtained. Moreover, it becomes easy to increase the polishing rate of the hard and brittle material by the polishing composition.

  (4) The manufacturing method of a hard and brittle material substrate includes a polishing step of polishing a substrate material made of a hard and brittle material using the polishing composition described in the above section (1). Thereby, a hard and brittle material substrate with improved surface accuracy can be obtained. Moreover, it becomes easy to increase the polishing rate of the substrate raw material by the polishing composition.

The embodiment may be modified as follows.
-You may add an additive in the said polishing composition as needed. Moreover, you may add an additive in the said fine polishing composition as needed. Examples of additives include chelating agents, surfactants, antiseptics, antifungal agents, and rust inhibitors.

  The polishing composition and the fine polishing composition may be manufactured and sold in the form of a dilution stock solution, and may be used after being diluted. That is, it may be prepared by diluting the dilution stock solution with water.

  The polishing composition and the fine polishing composition may be manufactured and sold in the form of a dispersion / dissolution powder, and may be used by being dispersed / dissolved in water. That is, it may be prepared by mixing the powder for dispersion / dissolution with water.

-You may use the polishing composition of embodiment as said fine polishing composition.
In the polishing step, the used polishing composition may be collected and reused (circulated). For example, the above-described used polishing composition discharged from the polishing apparatus may be temporarily collected in a tank and supplied from the tank to the polishing apparatus again. In this case, since it is less necessary to treat the used polishing composition as a waste liquid, it is possible to reduce the environmental burden and the cost.

  Further, when the polishing composition is used in a circulating manner, a reduced amount of at least one of the components such as the abrasive in the polishing composition consumed or lost by being used for polishing the substrate material. You may make it perform replenishment. The components to be replenished may be added individually to the used polishing composition, or may be added to the used polishing composition in a mixture containing two or more components at any concentration.

-The said polishing composition can also be used for the use which grind | polishes materials other than a hard-brittle material.
Next, a technical idea that can be grasped from the embodiment will be described.
(A) The abrasive and the polishing composition used for polishing hard and brittle materials.

The embodiment will be described more specifically with reference to examples and comparative examples.
Examples 1 to 8 and Comparative Example 1 were prepared by mixing zirconium oxide particles with water, adjusting the pH to 7 with phosphorous acid or potassium hydroxide, and adjusting the content of zirconium oxide particles to 10% by mass. -3 polishing compositions were prepared. As the zirconium oxide particles, monoclinic zirconium oxide particles produced by wet process using badelite as a raw material were used. Table 1 shows the details of the zirconium oxide particles contained in the polishing composition of each example.

  In the column “D10”, “D50”, and “D90” in Table 1, in the particle size distribution of zirconium oxide particles, the integrated mass from the small particle size side of the integrated particle size distribution on the mass basis is 10% and 50%. , 90% particle size is shown respectively. “D10”, “D50”, and “D90” were measured using LA-950 manufactured by Horiba, Ltd.

  The “Production” column in Table 1 shows the production method of zirconium oxide particles. “ZD” indicates that zirconium oxide particles manufactured by a dry method using zircon sand as a raw material is used, and “BD” indicates that zirconium oxide particles manufactured by a wet method using badelite as a raw material are used.

The “(D90−D10) / D50” column in Table 1 shows the value of (D90−D10) / D50 calculated based on the measured “D10”, “D50”, and “D90”.
The “SA” column in Table 1 shows the specific surface area of the zirconium oxide particles. The specific surface area was measured by a nitrogen adsorption method using FlowSorbII2300 manufactured by Shimadzu Corporation.

The “purity” column in Table 1 shows the purity of the zirconium oxide particles. The purity was measured using XRF-1800 manufactured by Shimadzu Corporation.
In Table 1, the “SiO ₂ ” column and the “TiO ₂ ” column show the contents of silicon dioxide and titanium dioxide contained in the zirconium oxide particles, respectively. The content of silicon dioxide and titanium dioxide was measured using ICPE-9000 manufactured by Shimadzu Corporation.

  Using the polishing composition of each example, the surface of an aluminosilicate glass substrate for a magnetic disk having a diameter of 65 mm (about 2.5 inches) was polished under the conditions shown in Table 2. Then, the polishing rate was determined based on the difference in mass of the substrate before and after polishing. The polishing rate was evaluated as a relative value where the polishing rate value when Example 1 was used was 1. The results are shown in Table 3.

As shown in Table 3, Examples 1 to 8 using zirconium oxide particles having a particle size distribution with a specific surface area of 15.0 m ² / g or less and (D90-D10) / D50 of 2.0 or less are In any case, a polishing rate higher than those of Comparative Examples 1 to 3 using other zirconium oxide particles was obtained.

Claims (4)

An abrasive containing zirconium oxide particles,
The specific surface area of the zirconium oxide particles is 15.0 m ² / g or less,
The above-mentioned zirconium oxide particles have D90, D10, and D10, D50, D90 when the particle diameters at which the integrated mass from the small particle diameter side of the integrated particle size distribution on the mass basis is 10%, 50%, 90%, respectively. An abrasive having a particle size distribution in which a value obtained by dividing the difference by D50 is 2.0 or less. A polishing composition comprising the abrasive according to claim 1 and water,
Polishing composition characterized by content of the said abrasive | polishing material being 0.1 mass% or more.   A method for polishing a hard and brittle material, comprising polishing a hard and brittle material using the polishing composition according to claim 2.   The manufacturing method of the hard-brittle material board | substrate characterized by including the grinding | polishing process of grind | polishing the board | substrate raw material which consists of a hard-brittle material using the polishing composition of Claim 2.