TW201321492A - Abrasive grains, manufacturing process therefor, polishing slurry and process for manufacturing glass products - Google Patents

Abstract

The purpose of the present invention is to provide abrasive grains and a polishing slurry, both of which make it possible to polish an object to be polished at a high polish rate even when the amount of cerium oxide used is reduced. The present invention pertains to abrasive grains obtained by coating base particles with cerium oxide.

Description

Abrasive grain, manufacturing method thereof, polishing slurry and method for producing glass product

The present invention relates to an abrasive granule, a method for producing the same, a polishing slurry, and a method for producing a glass product.

In the polishing step in the manufacture of glass products such as a magnetic disk drive for a hard disk drive, a glass for liquid crystal, a semiconductor substrate, or a photomask, in order to improve productivity, various methods have been used to increase the polishing rate.

For example, Patent Document 1 indicates that the polishing rate can be increased by adding an additive to a polishing slurry containing cerium oxide crystal fine particles or cerium oxide-zirconia solid solution crystal fine particles, and a good glass substrate surface property can be obtained.

Patent Document 2 teaches that an abrasive material which is produced by using a cerium oxide particle having a primary particle diameter of 3 to 60 μm as a raw material in the polishing material is obtained, thereby obtaining an abrasive material which is subjected to high-speed polishing without damage.

Further, in Patent Document 3, it is pointed out that by polishing a substrate to be polished by using a composite oxide containing cerium and zirconium in a polishing liquid composition, scratches can be suppressed in the substrate to be polished, and high-speed polishing can be realized.

Prior technical literature Patent literature

Patent Document 1: International Publication No. 2010/038617

Patent Document 2: Japanese Patent Laid-Open No. 2010-30041

Patent Document 3: Japanese Patent Laid-Open No. 2010-16064

As described above, in the polishing step in the manufacture of a glass material such as a magnetic disk drive for a hard disk drive, a glass for liquid crystal, a semiconductor substrate, or a photomask, yttrium oxide is mainly used in terms of a high polishing rate. However, there are limited areas for mining, so there is difficulty in stabilizing supply, and prices have risen in recent years.

Accordingly, it is an object of the present invention to provide an abrasive grain and a polishing slurry which can grind an object to be polished at a high polishing rate with a small amount of cerium oxide used.

The present inventors have found that by using abrasive grains coated with cerium oxide on the mother phase particles for polishing the object to be polished, it is possible to polish the object to be polished at a higher polishing rate with less use of cerium oxide. Thus, the present invention has been completed.

That is, the present invention is as follows.

An abrasive granule which is coated with cerium oxide on a mother phase particle.

2. The abrasive granule according to above 1, wherein the parent phase particles are selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, aminosulfonic acid, phosphoric acid, oxalic acid, tartaric acid, citric acid, formic acid, glycolic acid, acetic acid, ascorbic acid, hydrogen peroxide, Solubility is obtained in an aqueous solution of at least one of ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

3. The abrasive grain according to 1 or 2 above, wherein the mother phase particle comprises at least one oxide selected from the group consisting of manganese oxide and zinc oxide.

4. The abrasive particles according to any one of the above 1 to 3, wherein the cerium oxide coated on the mother phase particles is 0.1% by mass to 25% by mass based on the mother phase particles.

5. The abrasive particles according to any one of the above 1 to 4, wherein the cerium oxide coated on the mother phase particles is from 0.1% by mass to 20% by mass based on the mother particles.

6. The abrasive granule according to any one of the above 1 to 5, which has a specific surface area of from 0.1 to 20 m ² /g.

A polishing slurry comprising the abrasive particles according to any one of the above 1 to 6.

A method for producing abrasive grains, which is a method for producing abrasive particles coated with cerium oxide on a mother phase particle, and which comprises the following steps (1) to (3) in sequence: (1) a step of dissolving a hydrazine compound in water to obtain an aqueous solution of hydrazine; (2) a step of coating the aqueous solution of the ruthenium source obtained in the step (1) on the mother phase particles to obtain the mother phase particles coated with the aqueous solution of the ruthenium source; (3) A step of calcining the mother phase particles coated with the aqueous solution of the cerium source obtained in the step (2) to obtain mother particles coated with cerium oxide.

9. The method for producing an abrasive according to the above 8, wherein in the step (2), the aqueous solution of the cerium source is sprayed onto the mother phase particles to obtain a mother phase particle coated with the aqueous solution of the cerium source.

10. The method for producing the abrasive grains according to the above 8 or 9, wherein the cerium compound is at least one selected from the group consisting of cerium acetate, cerium nitrate, cerium hydroxide, and barium sulfate.

A method of producing a glass article, comprising the step of grinding the glass using the abrasive particles according to any one of the above 1 to 6 or the polishing slurry as described above.

According to the abrasive grains and the polishing slurry of the present invention, the object to be polished can be polished at a higher polishing rate without using a large amount of cerium oxide.

Hereinafter, the present invention will be described in detail.

[abrasive grain]

The abrasive grains of the present invention are abrasive grains coated with cerium oxide on the mother phase particles, and include mother phase particles and cerium oxide covering the mother phase particles.

Examples of the mother phase particles include manganese oxide (Mn ₃ O ₄ , Mn ₂ O ₃ , MnO ₂ ), zinc oxide (ZnO), iron oxide (Fe ₃ O ₄ , Fe ₂ O ₃ ), and copper oxide (Cu). ₂ O, CuO), alumina (Al ₂ O ₃ ), cerium oxide (SiO ₂ ), chromium oxide (Cr ₂ O ₃ , CrO ₂ ), and zirconia (ZrO ₂ ). These parent phase particles are usually commercially available.

The cerium oxide coated on the mother phase particles has high adhesion to the object to be polished, and cannot be easily dissolved. Therefore, there is a disadvantage that the rinsing property after polishing is inferior. Therefore, from the viewpoint of improving the detergency after polishing, it is preferably selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, aminosulfonic acid, phosphoric acid, oxalic acid, tartaric acid, citric acid, formic acid, glycolic acid, The mother phase particles are produced by dissolving in an aqueous solution of at least one of acetic acid, ascorbic acid, hydrogen peroxide, ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

As selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, aminosulfonic acid, phosphoric acid, oxalic acid, tartaric acid, citric acid, formic acid, glycolic acid, acetic acid, ascorbic acid, hydrogen peroxide, ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, and Among the aqueous solutions of at least one of potassium carbonate, solubility mother particles are exemplified by manganese oxide (Mn ₃ O ₄ , Mn ₂ O ₃ , MnO ₂ ), zinc oxide (ZnO), and iron oxide (Fe ₃ ). O ₄ , Fe ₂ O ₃ ) and copper oxide (Cu ₂ O, CuO).

More specifically, manganese oxide (Mn ₃ O ₄ , Mn ₂ O ₃ , MnO ₂ ) can be dissolved by hydrochloric acid, sulfuric acid, nitric acid, ascorbic acid, hydrogen peroxide or the like.

Zinc oxide (ZnO) can be dissolved by hydrochloric acid, nitric acid, sulfuric acid or the like.

Iron oxide (Fe ₃ O ₄ , Fe ₂ O ₃ ) can be dissolved by hydrochloric acid, nitric acid, sulfuric acid or the like.

Copper oxide (Cu ₂ O, CuO) can be dissolved by hydrochloric acid, nitric acid, sulfuric acid or the like.

These parent phase particles may be used alone or in combination of two or more. Further, these are more preferably manganese oxide or zinc oxide. Manganese oxide or zinc oxide has high solubility with respect to an acid, a base, an oxidizing agent or a reducing agent. Therefore, by using manganese oxide or zinc oxide as a mother phase particle, it is possible to contain an acid without affecting the object to be polished. The cleaning solution of the alkali, oxidant or reducing agent obtains a higher cleaning effect.

Here, "solubility" means that 0.1 to 1% by mass of the mother phase particles are dissolved in a mixture containing 0.01 to 2 mol% selected from sulfuric acid, hydrochloric acid, nitric acid, and aminosulfonic acid at room temperature for 1 hour. When an aqueous solution of phosphoric acid, oxalic acid, tartaric acid, citric acid, formic acid, glycolic acid, acetic acid, ascorbic acid, hydrogen peroxide, ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate or potassium carbonate is used, the amount of dissolution is 90. More than % by mass. Regarding the solubility of the mother phase particles, the test can be carried out in accordance with the following dissolution test in the examples.

As the mother phase particles, it can be used for selecting from sulfuric acid, hydrochloric acid, nitric acid, aminosulfonic acid, phosphoric acid, oxalic acid, tartaric acid, citric acid, formic acid, glycolic acid, acetic acid, hydrogen peroxide, ascorbic acid, hydrogen peroxide, ammonia, hydrogen. It is soluble in an aqueous solution of at least one of sodium oxide, potassium hydroxide, sodium carbonate and potassium carbonate, and is used in a washing step after polishing, and contains a selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, aminosulfonic acid, and phosphoric acid. , oxalic acid, tartaric acid, citric acid, formic acid, glycolic acid, acetic acid, hydrogen peroxide, ascorbic acid, hydrogen peroxide, ammonia, hydrogen The cleaning liquid is washed with at least one of sodium oxide, potassium hydroxide, sodium carbonate, and potassium carbonate, whereby a high cleaning effect can be obtained without affecting the object to be polished.

The coating amount of the mother particles of the cerium oxide is preferably 0.1 to 25% by mass, more preferably 0.1 to 20% by mass, still more preferably 1 to 10% by mass, even more preferably 1 to 5% by mass, in terms of cerium oxide. . When the coating amount is 0.1% by mass or more, the effect of improving the polishing rate can be obtained, and if it is 25% by mass or less, the amount of ruthenium used can be reduced, and if it is 20% by mass or less, the amount of ruthenium used can be further reduced.

The specific surface area of the abrasive grains coated with the mother particles of cerium oxide is preferably from 0.1 to 20 m ² /g, more preferably from 0.5 to 15 m ² /g, still more preferably from 1 to 10 m ² /g. When the specific surface area of the abrasive grains is 0.1 m ² /g or more, the polishing damage caused by the coarse particles can be suppressed, and if it is 20 m ² /g or less, a sufficient polishing rate can be obtained. The specific surface area of the abrasive grains was measured in the examples by the method described later.

[Method of manufacturing abrasive grains]

The abrasive grains of the present invention can be produced by a production method including the following steps (1) to (3) in sequence.

(1) a step of dissolving a ruthenium compound in water to obtain an aqueous solution of ruthenium source; (2) a step of coating an aqueous solution of ruthenium source obtained in the step (1) on the mother phase particles to obtain mother phase particles coated with an aqueous solution of ruthenium source (3) a step of calcining the mother phase particles coated with the aqueous solution of the cerium source obtained in the step (2) to obtain mother particles coated with cerium oxide.

Hereinafter, each step will be explained.

(1) a step of obtaining a hydrazine aqueous solution by dissolving a hydrazine compound in water

As the cerium compound, cerium acetate, cerium nitrate, cerium hydroxide or cerium sulfate is preferred in terms of availability and solubility in water. These hydrazine compounds may be used alone or in combination of two or more.

The concentration of the ruthenium compound in the aqueous solution of ruthenium is appropriately adjusted by considering the amount of ruthenium oxide to be coated on the mother phase particles and the amount of the ruthenium source aqueous solution coated on the mother phase particles in the following step (2). can. When the concentration of the ruthenium compound in the aqueous solution of ruthenium is set to be equal to or lower than the solubility of the ruthenium compound, the aqueous solution of ruthenium source can be uniformly coated on the mother phase particles in the following step (2), which is preferable.

In the following step (2), when the aqueous solution of the cerium source is coated on the mother phase particles by spraying the aqueous solution of the cerium source onto the mother phase particles, the concentration of the cerium compound in the aqueous solution of the cerium source is preferably set to 5 to 60% by mass, more preferably 10 to 60% by mass.

In the step (2), when the aqueous solution of the cerium source is coated on the mother phase particles by immersing the mother phase particles in the aqueous solution of the cerium source, the concentration of the cerium compound in the aqueous solution of the cerium source is preferably set to 1~ 40% by mass, more preferably 1 to 20% by mass.

In the step (2), when the aqueous solution of the cerium source is coated on the mother phase particles by applying the aqueous solution of the cerium source to the mother phase particles, the concentration of the cerium compound in the aqueous solution of the cerium source is preferably set to 1~ 60% by mass, more preferably 1 to 40% by mass.

(2) a step of obtaining the mother phase particles coated with the aqueous solution of the ruthenium source by coating the aqueous solution of the ruthenium source obtained in the step (1) on the mother phase particles

Step (2) is to coat the mother phase particles with the aqueous solution of the hydrazine source obtained in the step (1). The step of precipitating the cerium compound to the surface of the mother phase particles using water as a medium.

As a method of coating the aqueous solution of the cerium source on the mother phase particles, for example, spraying, dipping or coating can be mentioned. In these, the spraying does not require a drying step, and is preferred from an industrial standpoint.

(2-1) Spray

In the case of using a spray, the aqueous solution of the cerium source is coated on the mother phase particles by, for example, spraying an aqueous solution of the cerium source onto the mother phase particles by means of an atomizer, a sprayer or the like. At this time, the mother phase particles can be uniformly coated with the aqueous solution of the cerium source by stirring the mother phase particles each time the spraying.

As a specific method, for example, a method in which the mother phase particles are placed in a plastic bag and the atomizer is used to spray the aqueous solution of the helium source is exemplified.

Further, for example, it is also industrially advantageous to carry out thermal drying by a rotary kiln and to spray the aqueous solution of the cerium source while stirring the mother phase particles by a rotary machine.

The amount of the mother phase particles sprayed on the mother phase particles is preferably from 0.1 to 40% by mass, more preferably from 5 to 30% by mass, even more preferably from 10 to 25% by mass.

When the amount of the spray is 0.1% by mass or more, the aqueous solution spreads over the entire mother phase particles to achieve uniform coating. When it is 40% by mass or less, it can be directly supplied to the baking step without forming a paste or a liquid, and therefore the drying step can be omitted, which is preferable.

The spray condition is usually preferably set to 0 to 200 °C.

(2-2) impregnation

In the case of using impregnation, the mother phase particles are immersed in an aqueous solution of lanthanum source. The aqueous solution of lanthanum is coated on the mother phase particles. The amount of the mother phase particles immersed in the aqueous solution of the cerium source is usually preferably from 1 to 60% by mass, more preferably from 10 to 50% by mass, based on the aqueous solution.

By setting the amount of the mother phase particles to be immersed in the aqueous solution of the cerium source to 1% by mass or more, the amount of water to be evaporated can be reduced, and the cerium compound can be uniformly coated by being 60% by mass or less.

The immersion conditions are usually preferably from 0.1 to 24 hours at 0 to 90 °C.

The cerium source aqueous solution is coated on the mother phase particles by dipping, and then dried to precipitate the cerium compound to the surface of the mother phase particles. Further, the drying condition is usually preferably from 2 to 24 hours at 80 to 200 °C.

In the case of coating by immersion, it is preferable that the amount of the cerium compound to be coated on the mother phase particles after the mother phase particles are immersed in the hydrazine aqueous solution and dried is preferably 1 to 50% by mass based on the mother phase particles. More preferably, it is set to 5 to 50% by mass, and further preferably set to 5 to 30% by mass.

When the coating amount is 1% by mass or more, the ruthenium compound is spread over the entire mother phase particles to achieve uniform coating. When it is 50% by mass or less, cerium oxide does not precipitate separately.

(2-3) Coating

In the case of coating, the aqueous solution of the cerium source is applied to the mother phase particles by, for example, a rolling granulation apparatus, and the mother phase particles are coated with the aqueous solution of the cerium source.

The coating amount of the aqueous solution of the cerium source to the mother phase particles is preferably from 1 to 100% by mass, more preferably from 5 to 80% by mass, even more preferably from 10 to 60% by mass, based on the mother phase particles.

When the coating amount is 1% by mass or more and 100% by mass or less, the aqueous solution is spread over The mother phase particles as a whole can achieve a uniform coating.

The coating conditions are usually preferably set to 0 to 90 °C.

(3) a step of calcining the mother phase particles coated with the aqueous solution of the ruthenium source obtained in the step (2) to obtain mother particles coated with ruthenium oxide

The step (3) is a step of obtaining a mother phase particle coated with cerium oxide by baking the mother phase particles coated with the aqueous solution of the cerium source obtained in the step (2) to oxidize the cerium compound.

The calcination temperature is preferably from 300 to 1,000 ° C, more preferably from 400 to 1000 ° C, and still more preferably from 400 to 800 ° C. By setting the calcination temperature to 300° C. or more, the cerium compound can be decomposed to precipitate cerium oxide, and by setting it to 1000° C. or less, it is possible to suppress generation of coarse particles due to grain growth and to produce abrasive grains having less damage.

The calcination environment is preferably in the atmosphere, and is preferable in terms of cost. Further, the baking time is usually preferably set to 2 to 72 hours.

The coarse particles can also be removed by classifying the calcined product. As a method of classification, a well-known method, such as a sieve or a classifier, is mentioned, for example.

The abrasive grains in the present invention can be produced by the above steps (1) to (3), and other steps can be carried out as long as they do not affect each step. As the other steps, for example, the above-described drying or classification step and the like can be mentioned. Further, the abrasive grains in the present invention may be produced by a method which does not have one or two or more steps in the above steps (1) to (3).

(grinding slurry)

The abrasive slurry of the present invention can be dispersed in a dispersion medium such as water to produce a polishing slurry. The concentration of the abrasive grains in the polishing slurry is preferably from 0.1 to 40% by mass. More preferably, it is 1 to 30% by mass, and further preferably 1 to 20% by mass. When the concentration of the abrasive grains is 0.1% by mass or more, a sufficient polishing rate can be exhibited, and the polishing can be performed efficiently by 40% by mass or less.

Examples of the dispersion medium include water and alcohol. Examples of the alcohol include methanol, ethanol, 2-propanol, and ethylene glycol.

A dispersing agent may also be added to the slurry. As the dispersing agent, those known may be used, and examples thereof include sodium citrate, sodium polyacrylate, ammonium polyacrylate, polyacrylic acid-maleic acid copolymer, pyridine carboxylic acid, and carboxymethyl cellulose.

The polishing slurry can also be subjected to dispersion treatment. A known method can be used for the dispersion treatment, and examples thereof include a homogenizer, an ultrasonic homogenizer, a ball mill, a bead mill, and a wet jet mill.

The pH of the polishing slurry is preferably from 2 to 12, more preferably from 5 to 12, still more preferably from 5 to 11. By the pH value of 2 or more, polishing can be performed without dissolving the abrasive grains, and if it is 12 or less, polishing can be performed without affecting the object to be polished.

The volume-based median diameter (D ₅₀ ) of the polishing slurry is preferably from 0.1 to 20 μm, more preferably from 0.5 to 20 μm, still more preferably from 0.5 to 10 μm. The median diameter of the polishing slurry was measured in the examples by the following method.

When the median diameter of the polishing slurry is 0.1 μm or more, a sufficient polishing rate can be exhibited, and by 20 μm or less, polishing damage can be suppressed.

[Method for manufacturing glass products]

(grinding step)

The method for producing a glass article of the present invention comprises using a coating on a mother phase particle A grinding step of grinding the glass with cerium oxide abrasive grains or a polishing slurry containing the abrasive particles.

The method of polishing in the present invention is not particularly limited. For example, it is preferred to polish the glass into a mirror-like shape while moving the polishing cloth against the glass while bringing the glass into contact with the polishing cloth and supplying the polishing particles or the polishing slurry. . As a polishing cloth, a polishing pad made of a urethane is mentioned, for example.

(washing step)

The washing step should be appropriately selected depending on the glass product. For example, in the production of the glass substrate for a magnetic disk, the following washing step can be exemplified.

The method for producing a glass article of the present invention preferably comprises the steps of: using a compound selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, aminosulfonic acid, phosphoric acid, oxalic acid, tartaric acid, citric acid, formic acid, glycolic acid, acetic acid, ascorbic acid, peroxidation. A cleaning liquid (hereinafter, also referred to as a cleaning liquid used in the present invention) of at least one of hydrogen, ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate, and abrasive grains attached to the glass Or the slurry is washed.

In the above grinding step, used in selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, aminosulfonic acid, phosphoric acid, oxalic acid, tartaric acid, citric acid, formic acid, glycolic acid, acetic acid, ascorbic acid, hydrogen peroxide, ammonia, sodium hydroxide, In the case where the aqueous solution of at least one of potassium hydroxide, sodium carbonate, and potassium carbonate is a mother particle of the abrasive grains, the solvent is selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, aminosulfonic acid, phosphoric acid, and oxalic acid. Washing glass with at least one of tartaric acid, citric acid, formic acid, glycolic acid, acetic acid, ascorbic acid, hydrogen peroxide, ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate, thereby eliminating It has an effect on the glass and an excellent cleaning effect.

The cleaning solution used in the present invention is selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, aminosulfonic acid, phosphoric acid, oxalic acid, tartaric acid, citric acid, formic acid, glycolic acid, acetic acid, ascorbic acid, ammonia, sodium hydroxide, potassium hydroxide. The content of at least one of sodium carbonate and potassium carbonate is preferably 0.001 to 2 mol%, more preferably 0.01 to 1 mol%.

By selecting a cleaning solution selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, aminosulfonic acid, phosphoric acid, oxalic acid, tartaric acid, citric acid, formic acid, glycolic acid, acetic acid, ascorbic acid, hydrogen peroxide, ammonia, sodium hydroxide, hydrogen The content of at least one of potassium oxide, sodium carbonate, and potassium carbonate is 0.001 mol% or more in total, and the amount of elution is easily maintained. Moreover, by setting it as 2 mol% or less, the influence on glass can be suppressed.

The cleaning solution used in the present invention preferably contains a cleaning aid. Examples of the cleaning aid include a surfactant for lowering the surface tension and an acid having a buffering effect for stably maintaining the pH.

Examples of the surfactant include nonionic surfactants such as acetylene glycol and anionic surfactants such as sodium polyacrylate.

Further, examples of the acid having a buffering effect for stably maintaining the pH value include an acid having a pKa of 2 to 5 and having one or more carboxylic acid groups. Specifically, for example, citric acid is used as an acid which can be expected to have a buffering effect, and various organic acids can also be used.

The cleaning liquid used in the present invention preferably contains water as a solvent. Examples of the water include deionized water, ultrapure water, charged ionized water, hydrogen water, and ozone water. Further, the water has a function of controlling the fluidity of the washing liquid used in the present invention, and therefore the content thereof can be combined with the washing of the target such as the washing speed. The characteristics are appropriately set, and it is usually preferably 55 to 98% by mass.

In the washing step, it is preferred that the washing liquid is directly contacted with the glass to be washed. As a method of directly contacting the washing liquid with the glass, for example, a method in which the washing liquid is filled in the washing tank and the glass is placed therein, and the washing liquid is sprayed from the nozzle onto the glass, and Erasing using a sponge made of polyvinyl alcohol, etc. The cleaning solution used in the present invention can be applied to any of the above methods, but in the case of more effective cleaning, it is preferred to use an ultrasonic cleaning with immersion cleaning.

In the washing step, the time for bringing the washing liquid into contact with the glass is preferably 30 seconds or longer. By setting it to 30 seconds or more, sufficient washing effect can be obtained.

In the washing step, the temperature of the washing liquid may be room temperature, or may be heated to about 40 to 80 ° C and used, preferably 80 ° C or less. By setting the temperature of the cleaning liquid to 80 ° C or lower, it is possible to prevent thermal decomposition of the acid, alkali, oxidizing agent or reducing agent contained in the cleaning liquid. Further, in the configuration of the apparatus, when the cleaning liquid is at a temperature close to 100 ° C, evaporation of water causes difficulty in controlling the pH, and therefore it is preferably 80 ° C or lower.

It is more effective if it is washed with water or an alkaline detergent after the above washing step. Further, it is also possible to use a combination of water washing before the above washing step.

(other steps)

In the case where the glass product is a glass substrate for a magnetic disk or a glass substrate for a high-quality liquid crystal display, the method for producing the glass product of the present invention is preferably included in the cleaning step using a colloidal cerium oxide. The finished grinding step of the main surface of the grain slurry grinding glass is taken as another step.

Examples of the glass product produced by the production method of the present invention include a disk substrate facing a hard disk drive, a semiconductor substrate, a photomask substrate, and a glass substrate such as a display substrate, and a lens and a CCD (charge coupled device). Component) blue filter glass and cover glass. The magnetic disk can be manufactured by forming a magnetic recording layer on the main surface of the glass substrate for a magnetic disk manufactured by the manufacturing method of the present invention.

Example

Hereinafter, the present invention will be described by way of examples, but the invention is not limited thereto.

(1) Preparation of abrasive grains and grinding slurry

[example 1]

3 L of distilled water and 37.5 g of glycine (manufactured by Kanto Chemical Co., Ltd.) were dissolved in a glass tank, and the water temperature was maintained at 50 ° C by a push-type heater while stirring. 200 g of manganese (manufactured by Kanto Chemical Co., Ltd.) was slowly introduced therein, and filtered using a sieve having a mesh size of 150 μm. The obtained solution was dried overnight at 80 ° C, and calcined at 700 ° C for 8 hours under the atmosphere to obtain an oxide.

The obtained oxide is manganese oxide (Mn ₂ O ₃ ). The X-ray distribution of the obtained manganese oxide was measured by TTR-III (manufactured by RIGAKU Co., Ltd.). The results are shown in Fig. 1.

Further, the specific surface area of the obtained manganese oxide was measured by ASAP2020 (manufactured by Shimadzu Corporation). The results are shown in Table 1.

20 g of obtained manganese oxide, 378 g of distilled water, and 2 g of a dispersing agent (POLITY A-550, manufactured by LION Co., Ltd.) were mixed, and a homogenizer was used for 15 minutes. Into the slurry. The abrasive grain concentration in the polishing slurry was 5% by mass, and the dispersant concentration was 0.5% by mass.

The results obtained by measuring the volume-based median diameter (D ₅₀ ) of the obtained polishing slurry by MT3300EXII (manufactured by Nikkiso Co., Ltd.) and pH values are shown in Table 1.

[Example 2]

30 g of manganese oxide obtained in Example 1 was placed in a plastic bag, and 6.9 g of an aqueous solution of 16.9% by mass of barium acetate monohydrate (manufactured by Kanto Chemical Co., Ltd.) was sprayed with a nebulizer. The amount of the spray was 23% by mass based on the manganese oxide, and was 2% by mass in terms of cerium oxide.

Thereafter, it was baked at 700 ° C for 8 hours under the atmosphere. The obtained oxide was coated with Mn ₂ O _{3 of} CeO ₂ . The X-ray distribution of the obtained cerium oxide-coated manganese oxide was analyzed in the same manner as in Example 1. The results are shown in Fig. 1. As shown in Fig. 1, in addition to Mn ₂ O ₃ , a peak belonging to CeO ₂ was observed at 28.4°, and it was confirmed that cerium oxide was precipitated.

Further, the specific surface area of the obtained cerium oxide-coated manganese oxide was measured in the same manner as in Example 1. The results are shown in Table 1.

20 g of manganese oxide-coated manganese oxide, 378 g of distilled water, and 2 g of a dispersing agent (POLITY A-550, manufactured by LION Co., Ltd.) were mixed, and a homogenizer was used for 15 minutes to prepare a polishing slurry. The abrasive grain concentration in the polishing slurry was 5% by mass, and the dispersant concentration was 0.5% by mass.

The volume-based median diameter (D ₅₀ ) of the obtained polishing slurry was measured in the same manner as in Example 1, and the results and pH values are shown in Table 1.

[Example 3]

Zinc oxide (high purity) which is baked at 700 ° C for 8 hours under the atmosphere 20 g of reagents, reagents), 378 g of distilled water, and 2 g of a dispersing agent (manufactured by LION Co., Ltd., POLITY A-550) were mixed, and a homogenizer was used for 15 minutes to prepare a polishing slurry. The abrasive grain concentration in the polishing slurry was 5% by mass, and the dispersant concentration was 0.5% by mass.

The volume-based median diameter (D ₅₀ ) of the obtained polishing slurry was measured in the same manner as in Example 1, and the results and pH values are shown in Table 1.

[Example 4]

5.4 g of an aqueous solution of 5.4% by mass of ruthenium acetate monohydrate (manufactured by Kanto Chemical Co., Ltd.) was sprayed onto 30 g of the same zinc oxide as in Example 3 by means of a nebulizer. The amount of the spray was 18% by mass based on the zinc oxide, and was 0.5% by mass in terms of cerium oxide. Thereafter, it was baked at 700 ° C for 8 hours under the atmosphere. The obtained oxide was coated with ZnO of CeO ₂ .

20 g of zinc oxide-coated zinc oxide, 378 g of distilled water, and 2 g of a dispersing agent (POLITY A-550, manufactured by LION Co., Ltd.) were mixed, and a homogenizer was used for 15 minutes to prepare a polishing slurry. The abrasive grain concentration in the polishing slurry was 5% by mass, and the dispersant concentration was 0.5% by mass.

The volume-based median diameter (D ₅₀ ) of the obtained polishing slurry was measured in the same manner as in Example 1, and the results and pH values are shown in Table 1.

[Example 5]

100 g of an aqueous solution of 50 g of manganese oxide obtained in Example 1 and 9.7% by mass of ruthenium acetate monohydrate (manufactured by Kanto Chemical Co., Ltd.) was added to an eggplant type flask, and the flask was dried while being rotated by an evaporator. The amount of the aqueous solution of the cerium acetate monohydrate was 200% by mass based on the manganese oxide, and was 10% by mass in terms of cerium oxide. Thereafter, it was baked at 700 ° C for 8 hours under the atmosphere. The obtained oxide was coated with Mn ₂ O _{3 of} CeO ₂ .

20 g of the obtained cerium oxide-coated manganese oxide, 378 g of distilled water, and 2 g of a dispersing agent (POLITY A-550, manufactured by LION Co., Ltd.) were mixed, and a homogenizer was used for 15 minutes to prepare a polishing slurry. The abrasive grain concentration in the polishing slurry was 5% by mass, and the dispersant concentration was 0.5% by mass.

The volume-based median diameter (D ₅₀ ) of the obtained polishing slurry was measured in the same manner as in Example 1, and the results and pH values are shown in Table 1.

[Example 6]

150 g of 50 g of manganese oxide obtained in Example 1 and 150 g of an aqueous solution of barium acetate monohydrate (manufactured by Kanto Chemical Co., Ltd.) in an amount of 150 g were added to an eggplant type flask, and the flask was rotated while being rotated by an evaporator. The amount of the aqueous solution of the cerium acetate monohydrate was 300% by mass based on the manganese oxide, and was 20% by mass in terms of cerium oxide. Thereafter, it was baked at 700 ° C for 8 hours under the atmosphere. The obtained oxide was coated with Mn ₂ O _{3 of} CeO ₂ .

20 g of the obtained cerium oxide-coated manganese oxide, 378 g of distilled water, and 2 g of a dispersing agent (POLITY A-550, manufactured by LION Co., Ltd.) were mixed, and a homogenizer was used for 15 minutes to prepare a polishing slurry. The abrasive grain concentration in the polishing slurry was 5% by mass, and the dispersant concentration was 0.5% by mass.

The volume-based median diameter (D ₅₀ ) of the obtained polishing slurry was measured in the same manner as in Example 1, and the results and pH values are shown in Table 1.

[Example 7]

Adding 100 g of zinc oxide (manufactured by High Purity Chemical Co., Ltd.) and 100 g of 9.7% by mass of ruthenium acetate monohydrate (manufactured by Kanto Chemical Co., Ltd.) in an aqueous solution at 800 ° C for 8 hours in the atmosphere The flask was dried while rotating the flask while using an evaporator. The amount of the aqueous solution of the cerium acetate monohydrate was 200% by mass based on the zinc oxide, and was 10% by mass in terms of cerium oxide. Thereafter, it was baked at 700 ° C for 8 hours under the atmosphere. The obtained oxide was coated with ZnO of CeO ₂ .

20 g of the obtained cerium oxide-coated zinc oxide, 378 g of distilled water, and 2 g of a dispersing agent (POLITY A-550, manufactured by LION Co., Ltd.) were mixed, and a homogenizer was used for 15 minutes to prepare a polishing slurry. The abrasive grain concentration in the polishing slurry was 5% by mass, and the dispersant concentration was 0.5% by mass.

The volume-based median diameter (D ₅₀ ) of the obtained polishing slurry was measured in the same manner as in Example 1, and the results and pH values are shown in Table 1.

[Example 8]

50 g of zinc oxide (manufactured by High Purity Chemical Co., Ltd.) and 50 g of an aqueous solution of ruthenium acetate monohydrate (manufactured by Kanto Chemical Co., Ltd.) added to the eggplant at a temperature of 700 ° C for 8 hours. The flask was dried while rotating the flask while using an evaporator. The amount of the aqueous solution of the cerium acetate monohydrate was 300% by mass based on the zinc oxide, and was 20% by mass in terms of cerium oxide. Thereafter, it was baked at 700 ° C for 8 hours under the atmosphere. The obtained oxide was coated with ZnO of CeO ₂ .

20 g of the obtained cerium oxide-coated zinc oxide, 378 g of distilled water, and 2 g of a dispersing agent (POLITY A-550, manufactured by LION Co., Ltd.) were mixed, and a homogenizer was used for 15 minutes to prepare a polishing slurry. The abrasive grain concentration in the polishing slurry was 5% by mass, and the dispersant concentration was 0.5% by mass.

The volume-based median diameter (D ₅₀ ) of the obtained polishing slurry was measured in the same manner as in Example 1, and the results and pH values are shown in Table 1.

(2) Dissolution test

30 mL of 1 mol/L sulfuric acid and 0.3 g of hydrogen peroxide, and cerium oxide coated with manganese oxide obtained in Example 2 of (1), zinc oxide coated with cerium oxide obtained in Example 4, or oxidized 30 mg of 铈 (product name A10, manufactured by Showa Denko Co., Ltd.) was placed in a centrifuge tube, and stirred at room temperature for 1 hour using a turntable.

After stirring, the mixture was centrifuged at 3,500 rpm for 10 minutes using a centrifugal separator (device name: 5220, manufactured by Kubota Co., Ltd.), the supernatant was removed, and the mixture was poured into distilled water and centrifuged in the same manner to carry out the supernatant. Remove. Thereafter, it was dried in a thermostat at 80 ° C for 3 hours. After drying, the residual amount of each of the abrasive grains was measured. From this value, the ratio (dissolution amount) of the abrasive grains dissolved in the aqueous solution was determined.

That is, the elution amount of the abrasive grains in various aqueous solutions is a value obtained by subtracting the residual amount of the abrasive grains in each aqueous solution, and is expressed by a percentage (%). The results are shown in Table 2.

As shown in Table 2, the abrasive grains obtained by using manganese oxide or zinc oxide as the mother phase particles and coating the mother phase particles with cerium oxide exhibit higher solubility to the cleaning liquid than cerium oxide.

According to the results, it is suggested that manganese oxide and zinc oxide exhibiting higher solubility with respect to a cleaning liquid containing an acid, a base, an oxidizing agent or a reducing agent are parent phase particles, and the mother phase particles are coated with cerium oxide. The abrasive grains obtained have a high washing effect by using the washing liquid.

(3) Grinding test

The polishing test was carried out using the polishing slurs of Examples 1 to 8 obtained in (1). The polishing slurry of Example 2 was used in Example 1, the polishing slurry of Example 4 was used in Example 2, the polishing slurry of Example 1 was used in Comparative Example 1, and the polishing slurry of Example 3 was used in Comparative Example 2, and Examples 3, the polishing slurry of Example 5 was used, the polishing slurry of Example 6 was used in Example 4, the polishing slurry of Example 7 was used in Example 5, and the polishing slurry of Example 8 was used in Example 6.

Glass was used for the object to be polished, the grinding pressure was set to 12 kPa, and the platen speed was set to 40 rpm. A 12B single-side grinder (manufactured by SpeedFam Co., Ltd.) was used as a grinder, and FX8H-101U (manufactured by Fujibo Co., Ltd.) was used as a polishing pad.

The slurry was circulated at 100 ml/min and ground for 20 minutes. root The polishing rate (μm/min) was calculated from the difference in weight before and after the polishing. The results are shown in Table 3.

As shown in Table 3, when the glass was polished by a polishing slurry containing abrasive grains obtained by coating the mother phase particles with cerium oxide, it was found that compared with the polishing slurry containing the abrasive grains including only the mother phase particles, The grinding speed is increased.

Moreover, it is understood that the coating amount of the mother particles of cerium oxide is preferably 0.1 to 25% by mass in terms of cerium oxide.

The present invention has been described in detail with reference to the specific embodiments of the invention. In addition, the present application is based on a Japanese patent application filed on Sep. 9, 2011 (Japanese Patent Application No. 2011-197379).

Industrial availability

The abrasive grains and polishing slurry of the present invention can be used for a glass substrate such as a disk substrate, a semiconductor substrate, a photomask substrate, and a display substrate facing a hard disk drive. And in the grinding step in the manufacture of glass products such as blue filter glass and cover glass for lenses and CCDs.

Figure 1 shows the X-ray distribution of manganese oxide.

Claims (11)

An abrasive granule which is coated with cerium oxide on a mother phase particle. The abrasive particle of claim 1, wherein the parent phase particles are selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, aminosulfonic acid, phosphoric acid, oxalic acid, tartaric acid, citric acid, formic acid, glycolic acid, acetic acid, ascorbic acid, hydrogen peroxide, ammonia. Solubility is obtained in an aqueous solution of at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate. The abrasive grain of claim 1 or 2, wherein the parent phase particles comprise at least one oxide selected from the group consisting of manganese oxide and zinc oxide. The abrasive grains according to any one of claims 1 to 3, wherein the cerium oxide coated on the mother phase particles is from 0.1% by mass to 25% by mass based on the mother particles. The abrasive particles according to any one of claims 1 to 4, wherein the cerium oxide coated on the mother phase particles is from 0.1% by mass to 20% by mass based on the mother particles. The abrasive particles according to any one of claims 1 to 5, which have a specific surface area of 0.1 to 20 m ² /g. An abrasive slurry comprising the abrasive particles of any one of claims 1 to 6. A method for producing abrasive grains, which is a method for producing abrasive particles coated with cerium oxide on mother particles, and which comprises the following steps (1) to (3): (1) dissolving the cerium compound in water a step of obtaining an aqueous solution of a ruthenium source; (2) a step of coating the aqueous solution of the ruthenium source obtained in the step (1) on the mother phase particles to obtain a mother phase particle coated with the aqueous solution of the ruthenium source; (3) in the step (2) The obtained mother phase particles coated with an aqueous solution of cerium source are calcined to obtain cerium oxide-coated mother phase particles. The method for producing abrasive grains according to claim 8, wherein in the above step (2), The cerium source aqueous solution was sprayed onto the mother phase particles to obtain mother phase particles coated with the hydrazine source aqueous solution. The method for producing abrasive grains according to claim 8 or 9, wherein the cerium compound is at least one selected from the group consisting of cerium acetate, cerium nitrate, cerium hydroxide, and barium sulfate. A method of producing a glass article, comprising the step of grinding the glass using the abrasive particles of any one of claims 1 to 6 or the abrasive slurry of claim 7.