WO2015170743A1 - Polishing solution composition for sapphire plate - Google Patents

Abstract

This polishing solution composition for a sapphire plate contains alumina particles, an anionic polymer, and an aqueous medium. One example of a manufacturing method for a sapphire plate according to the present invention includes a step in which the polishing solution composition for a sapphire plate is supplied to a sapphire plate to be polished and the sapphire plate to be polished is polished. Another example of a manufacturing method for a sapphire plate according to the present invention includes a step in which the polishing solution composition for a sapphire plate is supplied to the sapphire plate to be polished and the sapphire plate to be polished is polished, and a step in which a sapphire plate to be polished, which is different from the previous sapphire plate to be polished, is polished using the polishing solution composition for a sapphire plate used in the previous step.

Description

Polishing liquid composition for sapphire plate

The present invention relates to a polishing liquid composition for a sapphire plate, a method for producing a sapphire plate using the same, and a method for polishing a sapphire plate to be polished.

Hard and brittle materials such as sapphire are indispensable as optical materials, electronic materials or mechanical materials.

For example, artificial sapphire plates are used as materials for various applications such as integrated circuit boards, infrared detection lenses, watches, and mobile terminal devices such as smartphones. In particular, with the rapid spread of mobile terminal devices, the demand for sapphire plates used as cover glasses is increasing rapidly. The cover glass of a portable terminal device is desired to have a high surface smoothness in order to improve the beauty of the portable terminal device.

In order to satisfy the surface smoothness of the sapphire plate, finish polishing using a polishing liquid composition containing silica particles is performed. By using silica (Mohs hardness 7) particles having a hardness lower than that of the sapphire (α-alumina, Mohs hardness 9) plate as abrasive grains, pits and scratches are prevented from occurring on the surface of the sapphire plate. However, although sapphire is excellent in mechanical, chemical, and thermal stability, there is a problem that the polishing rate is low in finish polishing using silica particles.

In response to the problem of the polishing rate, for example, Patent Document 1 discloses that the polishing rate is improved by controlling the pH of the polishing composition to make the zeta potentials of the silica particles and the sapphire substrate have opposite signs. Has been. Patent Documents 4, 9, and 10 disclose a polishing composition containing an anionic surfactant added as a dispersing agent for abrasive grains and containing silica particles as abrasive grains. Although it is disclosed that the sapphire polishing slurry containing grains contains an anionic surfactant as a dispersant, it is not disclosed that the anionic surfactant is an anionic polymer (Patent Document 2). 3, 5, 6, 8, 11).

JP 2011-2111178 A JP 2011-62815 A JP-T-2006-524583 JP 2009-28814 A JP 2008-211040 A JP 2004-168622 A WO2011 / 136387 JP 2012-700 A JP 2011-183530 A Special table 2009-538236 WO2009 / 151120

On the other hand, for the purpose of improving productivity, it is desired to further improve the surface smoothness while further improving the polishing rate of the sapphire plate.

The present invention provides a polishing liquid composition for a sapphire plate that has a high polishing rate and can reduce the surface roughness, a method for producing a sapphire plate using the same, and a method for polishing a polished sapphire plate.

An example of the polishing composition for a sapphire plate of the present invention is a polishing composition for a sapphire plate containing alumina particles, an anionic polymer, and an aqueous medium.

Another example of the polishing liquid composition for sapphire plates of the present invention is a polishing liquid composition for sapphire plates containing alumina particles, a rheology modifier, and an aqueous medium.

An example of the method for producing a sapphire plate of the present invention is a method for producing a sapphire plate, comprising the step of supplying the polishing composition for a sapphire plate of the present invention to polish the sapphire plate to be polished. Is the method.

Another example of the method for producing a sapphire plate of the present invention includes a step of supplying the polishing composition for a sapphire plate of the present invention to the polished sapphire plate and polishing the polished sapphire plate, and the above step. And a step of polishing a polished sapphire plate different from the polished sapphire plate using the used sapphire plate polishing liquid composition.

The polishing method for a polished sapphire plate of the present invention includes a step of supplying the polishing composition for a sapphire plate of the present invention to the polished sapphire plate and polishing the polished sapphire plate. This is a polishing method.

According to the present invention, a polishing composition for a sapphire plate that has a high polishing rate and can reduce surface roughness, a method for manufacturing a sapphire plate using the same, and a method for polishing a sapphire plate to be polished are provided. it can.

When an anionic polymer is added to an acidic polishing liquid composition used for polishing a glass substrate to be polished or an aluminum alloy substrate plated with Ni—P, the anionic polymer is adsorbed on the polishing pad, It is generally recognized that the polishing rate decreases because it functions as a protective film for the object to be polished. In contrast, the present invention is a polishing liquid composition used for polishing a sapphire plate to be polished, and the polishing liquid composition containing alumina particles and an aqueous medium has either an acidic or alkaline pH. However, the addition of an anionic polymer improves the polishing rate when the polished sapphire plate is polished, and the surface roughness of the polished surface to be polished (hereinafter also referred to as “polishing surface”). Is based on the unexpected finding that

When the polishing liquid composition for sapphire plates of the present invention (hereinafter referred to as “polishing liquid composition”) is used for polishing the sapphire plate to be polished, it is significantly more than when a polishing liquid composition containing no anionic polymer is used. A decrease in shear viscosity is observed. Therefore, in the polishing composition of the present invention, a rheology modifier such as an anionic polymer loosens the aggregated alumina particles during polishing, and as a result, the number of effective abrasive grains is increased and effective. It is presumed that the polishing speed is improved and the surface roughness of the polished surface is reduced by reducing the grain size of the abrasive grains.

The polishing liquid composition of the present invention contains alumina particles (component A), an anionic polymer (component B), and an aqueous medium (component C).

[Alumina particles (component A)]
The polishing composition of the present disclosure includes alumina particles as abrasive grains. Examples of the alumina particles include α-alumina, intermediate alumina, amorphous alumina, fumed alumina, and the like. Among these, α-alumina is preferable from the viewpoint of improving the polishing rate.

The average particle diameter (average secondary particle diameter) measured by the dynamic light scattering method of alumina particles is preferably 0.2 μm or more, more preferably 0.25 μm or more, and still more preferably 0, from the viewpoint of improving the polishing rate. From the viewpoint of reducing the surface roughness, it is preferably 1.0 μm or less, more preferably 0.95 μm or less, still more preferably 0.90 μm or less, and even more preferably. Is 0.80 μm or less. In addition, this average secondary particle diameter can be calculated | required by the method as described in an Example.

In one or a plurality of embodiments, the alpha conversion rate of the alumina particles is preferably 50% or more, more preferably 60% or more, from the viewpoint of improving the polishing rate and reducing the surface roughness. This pregelatinization rate can be measured by powder X-ray diffraction, specifically, for example, by the method of the example.

The BET specific surface area of the alumina particles in the polishing liquid composition of the present disclosure is preferably 10 m ² / g or more, more preferably 20 m ² / g or more, still more preferably 40 m ² / g or more, from the viewpoint of improving the polishing rate. In view of the above, 200 m ² / g or less is preferable, 100 m ² / g or less is more preferable, and 60 m ² / g or less is more preferable.

The content of the alumina particles in the polishing liquid composition of the present disclosure is preferably 3% by mass or more, more preferably 5% by mass or more, still more preferably 7% by mass or more, and still more preferably from the viewpoint of improving the polishing rate. From the viewpoint of reducing the surface roughness, it is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, and even more preferably 20% by mass or less.

[Anionic polymer (component B)]
The polishing composition of the present invention contains a water-soluble polymer (component B) having an anionic group from the viewpoint of reducing the surface roughness of the polished object and improving the polishing rate. Further, when the polishing composition of the present invention contains a water-soluble polymer having an anionic group (hereinafter also referred to as “anionic polymer”), the polishing durability is also improved. The anionic polymer is adsorbed on the surface of the alumina particles, and contributes to improving the dispersibility of the alumina particles and suppressing aggregation of the alumina particles by charge repulsion. Therefore, it is presumed that the anionic polymer contributes to the improvement of the polishing rate and the reduction of the surface roughness. “Water-soluble” means having a solubility of 2 g / 100 ml or more in water.

Examples of the anionic group of the anionic polymer (component B) include a carboxylic acid group, a sulfonic acid group, a sulfate ester group, a phosphate ester group, and a phosphonic acid group. These anionic groups may take the form of neutralized salts. From the viewpoint of reducing the surface roughness, the anionic polymer preferably has at least one of a sulfonic acid group and a carboxylic acid group, and dispersibility of the alumina particles by interacting with a sugar compound described later. From the viewpoint of further improving the ratio, it is more preferable to have a carboxylic acid group.

In this specification, “sulfonic acid group” refers to a sulfonic acid group and / or salt thereof, and “carboxylic acid group” refers to a carboxylic acid group and / or salt thereof. Although there is no limitation in particular about the counter ion in case a sulfonic acid group or a carboxylic acid group takes the form of a salt, Specifically, a metal ion, an ammonium ion, an alkyl ammonium ion, etc. are mentioned. Specific examples of the metal include metals belonging to the periodic table (long period type) 1A, 1B, 2A, 2B, 3A, 3B, 4A, 6A, 7A, or Group 8. Among these metals, metals belonging to Group 1A, 3B, or Group 8 are preferable from the viewpoint of reducing surface roughness, and sodium and potassium belonging to Group 1A are more preferable. Specific examples of alkylammonium include tetramethylammonium, tetraethylammonium, tetrabutylammonium and the like. Among the counter ions, at least one selected from the group consisting of ammonium ions, sodium ions, and potassium ions is more preferable.

An anionic polymer having at least one of a sulfonic acid group and a carboxylic acid group is obtained by polymerizing a monomer having an ionic hydrophilic group such as a monomer having a sulfonic acid group or a monomer having a carboxylic acid group. It is preferable that it was obtained by. Polymerization of these monomers may be random, block, or graft.

Examples of the monomer having a sulfonic acid group include isoprene sulfonic acid, 2- (meth) acrylamido-2-methylpropane sulfonic acid, styrene sulfonic acid, methallyl sulfonic acid, vinyl sulfonic acid, allyl sulfonic acid, and isoamyl sulfonic acid. Examples thereof include lensulfonic acid and naphthalenesulfonic acid. Examples of the monomer having a carboxylic acid group include itaconic acid, (meth) acrylic acid, maleic acid and the like. Among these monomers, (meth) acrylic acid is preferable and acrylic acid is more preferable from the viewpoint of reducing the surface roughness of the polished object to be polished. That is, the anionic polymer preferably includes a structural unit derived from (meth) acrylic acid, and more preferably includes a structural unit derived from acrylic acid.

When the anionic polymer contains a structural unit derived from (meth) acrylic acid, the proportion of the structural unit derived from (meth) acrylic acid in the total structural unit of the anionic polymer is determined based on the polished object to be polished. From the viewpoint of reducing the surface roughness, preferably 50 mol% or more, more preferably 60 mol% or more, still more preferably 70 mol% or more, and from the viewpoint of improving the polishing rate, preferably 90 mol% or more, more preferably. Is 95% or more, more preferably 98 mol% or more, and still more preferably 100 mol%.

For the synthesis of an anionic polymer having at least one of a sulfonic acid group and a carboxylic acid group, a monomer other than a monomer having a sulfonic acid group and a monomer having a carboxylic acid group can also be used. . Examples of other monomers that can be used for polymerization of anionic polymers include aromatic vinyl compounds such as styrene, α-methylstyrene, vinyltoluene, and p-methylstyrene, methyl (meth) acrylate, ( (Meth) acrylic acid alkyl esters such as ethyl (meth) acrylate and octyl (meth) acrylate, aliphatics such as butadiene, isoprene, 2-chloro-1,3-butadiene and 1-chloro-1,3-butadiene Conjugated dienes, vinyl cyanide compounds such as (meth) acrylonitrile, vinylphosphonic acid, methacryloyloxymethyl phosphoric acid, methacryloyloxyethyl phosphoric acid, methacryloyloxybutyl phosphoric acid, methacryloyloxyhexyl phosphoric acid, methacrylyloxyoctyl Phosphoric acid, methacryloyloxydecyl phosphate, methacryloyloxy Lauryl phosphate, metallo-yl oxy stearyl phosphoric acid, phosphonic acid compounds such as methacryloyl oxy 1,4-dimethylcyclohexyl phosphate. These monomers can be used alone or in combination of two or more.

Preferred specific examples of the anionic polymer having at least one of a sulfonic acid group and a carboxylic acid group include polyacrylic acid and (meth) acrylic acid / isoprene from the viewpoint of reducing the surface roughness of the polished object. Sulfonic acid copolymer, (meth) acrylic acid / 2- (meth) acrylamide-2-methylpropanesulfonic acid copolymer, (meth) acrylic acid / isoprenesulfonic acid / 2- (meth) acrylamide-2-methylpropane Examples include sulfonic acid copolymers, (meth) acrylic acid / maleic acid copolymers, formalin condensates of styrene sulfonic acid, and styrene / isoprene sulfonic acid copolymers. Among these anionic polymers, polyacrylic acid and (meth) acrylic acid / 2- (meth) acrylamido-2-methylpropanesulfonic acid copolymer are used from the viewpoint of reducing the surface roughness of the polished object. One or more anionic polymers selected from polymers are preferred, and polyacrylic acid is more preferred.

[Weight average molecular weight of anionic polymer]
The weight average molecular weight of the anionic polymer is preferably 500 or more, more preferably 1000 or more, and even more preferably 1500 or more, from the viewpoint of reducing the surface roughness of the polished object. The weight average molecular weight of the anionic polymer is preferably 120,000 or less, more preferably 100,000 or less, further preferably 30,000 or less, from the viewpoint of reducing the surface roughness of the polished object. The following is still more preferable, and 8000 or less is even more preferable.

In addition, the said weight average molecular weight is computable based on the peak in the chromatogram obtained by applying the gel permeation chromatography (GPC) method on the following conditions.
Column: G4000PWXL + G2500PWXL (Tosoh Corporation)
Eluent: (0.2 M phosphate buffer) / (CH ₃ CN) = 9/1 (volume ratio)
Flow rate: 1.0 mL / min
Column temperature: 40 ° C
Detector: RI detector Standard material: Polyacrylic acid equivalent

Some of the anionic groups of the anionic polymer having at least one of a sulfonic acid group and a carboxylic acid group may take the form of a neutralized salt. The counter ion when a part of the anionic group takes a salt form is not particularly limited, and examples thereof include metal ions, ammonium ions, alkylammonium ions, and the like.

The content of the anionic polymer (component B) in the polishing liquid composition is preferably 1 mass ppm or more, more preferably 10 mass ppm or more, from the viewpoint of reducing the surface roughness of the polished object to be polished. Preferably it is 100 mass ppm or more, and still more preferably 200 mass ppm or more. The content of the anionic polymer (component B) in the polishing composition is preferably 5000 ppm by mass or less, more preferably 4000 ppm by mass or less, from the viewpoint of reducing the surface roughness of the polished object. More preferably, it is 3000 mass ppm or less, More preferably, it is 2000 mass ppm or less.

Content ratio of alumina particles (component A) and anionic polymer (component B) in the polishing composition [alumina particle content (mass ppm) / anionic polymer content (mass ppm)] Is preferably 10 or more, more preferably 20 or more, still more preferably 50 or more, and even more preferably 100 or more, from the viewpoint of reducing the surface roughness of the polished object to be polished. Therefore, it is preferably 200000 or less, more preferably 20000 or less, and still more preferably 2000 or less.

The rheology modifier contained in the polishing composition of the present invention is not limited to the anionic polymer as long as it can reduce the shear viscosity, and vinyl such as polyvinylpyrrolidone, polyvinyl alcohol, n-polyvinylformamide, and the like. At least one selected from polyethylene polymers, polyethylene glycol, polyethylene oxide, polypropylene glycol, polypropylene oxide, and other polyalkylene oxides and copolymers thereof, and copolymers with other polymers containing the above polymer as part of the structure It may be a seed polymer. These polymers may be used in combination with the anionic polymer.

[Aqueous medium (component C)]
Examples of the aqueous medium (component C) contained in the polishing liquid composition of the present invention include water such as ion-exchanged water and ultrapure water, or a mixed medium of water and a solvent. A miscible solvent (for example, an alcohol such as ethanol) is preferred. As the aqueous medium, ion-exchanged water or ultrapure water is more preferable, and ultrapure water is more preferable. When component C of the present invention is a mixed medium of water and a solvent, the ratio of water to the entire mixed medium is not particularly limited, but is preferably 95% by mass or more from the viewpoint of economy, and 98 More preferably, it is more preferably at least 100% by weight, still more preferably 100% by weight, and even more preferably 100% by weight.

The content of the aqueous medium (component C) in the polishing composition of the present invention is not particularly limited, and may be the remainder of component A, component B, and optional components described later.

The pH at 25 ° C. of the polishing composition of the present invention is preferably a strongly acidic region or strongly alkaline region other than 4-9 from the viewpoint of improving the polishing rate, preferably 3 or less, more preferably in the strongly acidic region. 2 or less, preferably 10 or more, more preferably 11 or more, preferably less than 14 in the strongly alkaline region.

The shear viscosity (Pa · s) of the polishing composition of the present invention at 25 ° C. at a shear rate of 100 (1 / s) measured in an environment of 25 ° C. and 50% RH is an improvement in polishing rate and surface roughness. From the viewpoint of reduction, it is preferably 0.01 (Pa · s) or less, more preferably 0.008 (Pa · s) or less, and still more preferably 0.007 (Pa · s) or less. Therefore, it is preferably 0.001 (Pa · s) or more, more preferably 0.0015 (Pa · s) or more, and still more preferably 0.002 (Pa · s) or more.

Since the rheology modifier contained in the polishing composition of the present invention has a function of reducing shear viscosity, it can also be called a shear viscosity reducing agent. The shear viscosity ratio calculated by the following formula is preferably 0.6 or less, more preferably 0.4 or less, and still more preferably 0, from the viewpoint of reducing the surface roughness of the polished object and improving the polishing rate. From the viewpoint of improving the polishing rate, it is preferably 0.01 or more, more preferably 0.05 or more, and still more preferably 0.1 or more. In the present application, the shear viscosity is a value obtained by measuring the polishing composition (25 ° C.) in an environment of 25 ° C. and 50% RH using a parallel plate rheometer and setting the gap between the plates to 100 μm. It can be determined by the method described in the examples.
Shear viscosity ratio = (Shear viscosity at a shear rate of 100 (1 / s) of the polishing composition) / (Shear rate of a polishing composition having the same composition as the polishing composition except that it does not contain a rheology modifier) Shear viscosity at 100 (1 / s))

The polishing liquid composition of the present invention may further contain conventionally known optional components depending on the intended use. When the polishing liquid composition of the present invention is, for example, a polishing liquid composition for a sapphire plate for a mobile terminal device such as a smartphone, the polishing liquid composition of the present invention is a compound having a sugar skeleton described below (component D). , An oxidizing agent (component E), a dispersant other than the alkaline polymer (component B), a pH adjuster (acid, alkali) (component F), an inorganic phosphate compound (component G), and the like. .

[Compound having a sugar skeleton (component D)]
The polishing composition of the present invention is a saccharide compound or a derivative thereof (hereinafter collectively referred to as “a polishing compound” from the viewpoint of improving the polishing rate, reducing the surface roughness of the polished object to be polished, and improving the polishing durability. And a compound having a sugar skeleton ”. When the carboxyl group of the anionic polymer and the hydroxyl group of the compound having a sugar skeleton (component D) interact, the compound having a bulky sugar skeleton (component D) is adsorbed to the alumina particles via the anionic polymer. As a result, the dispersibility of the alumina particles is further improved. As a result, it is assumed that the polishing rate can be further improved and the surface roughness of the polished object can be further reduced. . Further, as a result of the compound (component D) having a bulky sugar skeleton suppressing the agglomeration of abrasive grains during polishing of the sapphire plate, the polishing durability is improved and the decrease in the polishing rate can be suppressed over a long period of time. Further, in an example of the polishing composition of the present invention in which an anionic polymer (component B) and a compound having a sugar skeleton (component D) are used in combination, a further remarkable decrease in shear viscosity is observed.

The compound having a sugar skeleton (component D) may be any of monosaccharides, disaccharides, oligosaccharides, polysaccharides, and sugar alcohols. Examples of monosaccharides include glucose, fructose, xylose, arabinose, erythrose galactose, xylulose and the like, and disaccharides include sucrose, maltose, lactose and the like, and sugar alcohols include xylitol, erythritol, maltitol, Examples include sorbitol. These compounds having a sugar skeleton (component D) may be used alone or in combination of two or more. Among the compounds having the sugar skeleton (component D), from the viewpoint of improving the polishing rate and reducing the surface roughness of the polished object to be polished, a sugar alcohol, a monosaccharide, or a disaccharide is preferable, and sorbitol, sucrose, At least one compound selected from the group consisting of galactose and maltitol is preferred, and sorbitol is more preferred.

The content of the compound having a sugar skeleton (component D) in the polishing composition is 10 mass ppm or more from the viewpoint of improving the polishing rate, reducing the surface roughness of the polished object to be polished, and improving the polishing durability. More preferably, it is 50 mass ppm or more, More preferably, it is 100 mass ppm or more, More preferably, it is 500 mass ppm or more. Further, the content of the compound having a sugar skeleton (component D) in the polishing composition is preferably 10,000 ppm by mass or less, more preferably 5000 ppm by mass, from the viewpoint of reducing the surface roughness of the polished object. Hereinafter, it is more preferably 3000 ppm by mass or less, and still more preferably 1000 ppm by mass or less.

Content ratio of anionic polymer (component B) and a compound having a sugar skeleton (component D) [content of compound having a sugar skeleton (mass ppm) / content of anionic polymer in the polishing composition] (Mass ppm)] is preferably 0.01 or more, more preferably 0.1 or more, and still more preferably from the viewpoint of improving the polishing rate, reducing the surface roughness of the polished object to be polished, and improving the polishing durability. Is 0.5 or more, still more preferably 1 or more. In addition, the content ratio [content of the compound having a sugar skeleton (mass ppm) / content of anionic polymer (mass ppm)] improves the polishing rate, reduces the surface roughness of the polished object to be polished, From the viewpoint of improving polishing durability, it is preferably 5000 or less, more preferably 1000 or less, still more preferably 100 or less, and even more preferably 50 or less.

[Oxidizing agent (component E)]
The polishing composition of the present invention may further contain an oxidizing agent (component E). As the oxidizing agent (component E), peroxide, permanganic acid or a salt thereof, chromic acid or a salt thereof, peroxo acid or a salt from the viewpoint of improving the polishing rate and reducing the surface roughness of the polished object to be polished. The salt, oxygen acid or its salt, metal salt, nitric acid, sulfuric acid etc. are mentioned. These oxidizing agents may be used alone or in admixture of two or more.

Examples of the peroxide include hydrogen peroxide, sodium peroxide, barium peroxide and the like. Examples of permanganic acid or a salt thereof include potassium permanganate. Examples of chromic acid or a salt thereof include a chromic acid metal salt and a dichromic acid metal salt. Examples of peroxo acids or salts thereof include peroxodisulfuric acid, ammonium peroxodisulfate, metal peroxodisulfate, peroxophosphoric acid, peroxosulfuric acid, sodium peroxoborate, performic acid, peracetic acid, perbenzoic acid, perphthalic acid and the like. It is done. Examples of the oxygen acid or a salt thereof include hypochlorous acid, hypobromous acid, hypoiodous acid, chloric acid, bromic acid, iodic acid, sodium hypochlorite, calcium hypochlorite and the like. Examples of the metal salts include iron (III) chloride, iron (III) nitrate, iron (III) sulfate, iron (III) citrate, and iron (III) ammonium sulfate.

The oxidizing agent (component E) is preferably hydrogen peroxide, iron (III) nitrate, peracetic acid, ammonium peroxodisulfate, from the viewpoint of improving the polishing rate and reducing the surface roughness of the object to be polished. Among them, iron sulfate (III) and ammonium iron sulfate (III) are preferable, and hydrogen peroxide is more preferable from the viewpoint that metal ions do not adhere to the surface and are generally used and inexpensive.

The content of the oxidizing agent (component E) in the polishing composition is preferably 1000 ppm by mass or more, more preferably 1500 from the viewpoints of improving the polishing rate and reducing the surface roughness of the polished object. From the viewpoint of reducing the surface roughness of the polished object, it is preferably 10000 mass ppm or less, more preferably 8500 mass ppm or less, and even more preferably 8000 mass. ppm or less.

[PH adjuster (component F)]
The polishing composition of the present invention may contain an acid or alkali as a pH adjuster (component F) from the viewpoint of improving the polishing rate. Examples of the alkali include sodium hydroxide and potassium hydroxide. Acids include inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid or phosphoric acid, organic acids such as acetic acid, lactic acid, succinic acid, citric acid, nicotinic acid, oxalic acid, malonic acid, malic acid, tartaric acid, maleic acid, gluconic acid, etc. Is mentioned. These acids may be used alone or in combination of two or more. From the viewpoint of improving the polishing rate and reducing the surface roughness of the polished object, inorganic acids and organic acids are used. It is preferable that both are included.

From the viewpoint of improving the polishing rate and reducing the surface roughness of the polished object to be polished, the pH adjuster (component F) contains both an inorganic acid and an organic acid. Preferably sulfuric acid / citric acid, sulfuric acid / tartaric acid, sulfuric acid / maleic acid, phosphoric acid / citric acid, phosphoric acid / tartaric acid, more preferably sulfuric acid / citric acid, sulfuric acid / tartaric acid, phosphoric acid / citric acid, Sulfuric acid / citric acid is preferred.

When the acid contains both an inorganic acid and an organic acid, the mass ratio of the inorganic acid to the organic acid (the mass of the inorganic acid / the mass of the organic acid) is preferably 0.1 or more from the viewpoint of improving the polishing durability. More preferably, it is 0.2 or more, more preferably 0.5 or more. From the viewpoint of improving the polishing rate, it is preferably 10 or less, more preferably 5 or less, and still more preferably 3 or less.

The organic acid is preferably used in the production of the polishing composition in the form of a salt having high solubility in an aqueous medium, and an alkali metal salt or the like is preferably used. Examples of alkali metal salts of organic acids include alkali metal salts of acetic acid, lactic acid, succinic acid, citric acid, nicotinic acid, oxalic acid, malonic acid, malic acid, tartaric acid, maleic acid, and gluconic acid. Among these, from the viewpoint of improving the polishing rate, an organic acid salt having two or more carboxyl groups in one molecule is preferable, trisodium citrate or disodium maleate is more preferable, and trisodium citrate is still more preferable.

[Inorganic phosphate compound (component G)]
The polishing composition of the present invention preferably contains an inorganic phosphate compound (component G) from the viewpoint of improving the polishing rate and reducing the surface roughness. The inorganic phosphate compound is one or more inorganic phosphates selected from the group consisting of orthophosphate, phosphite, and hypophosphite from the viewpoint of improving the polishing rate and reducing the surface roughness. Compounds are preferred, and orthophosphates and phosphites are more preferred. The inorganic phosphate compound is preferably an alkali metal salt, an alkaline earth metal salt, or an ammonium salt. As the alkali metal or alkaline earth metal, magnesium, calcium, sodium, and potassium are preferable. Among these, from the viewpoint of suppressing aggregation of alumina particles, the inorganic phosphate compound is more preferably at least one selected from sodium salts, potassium salts, and ammonium salts.

Specific examples of the inorganic phosphate compound (component G) include sodium phosphate (Na ₃ PO ₄ ), potassium phosphate (K ₃ PO ₄ ), and phosphoric acid from the viewpoint of improving the polishing rate and reducing the surface roughness. Disodium monohydrogen (Na ₂ HPO ₄ ), monosodium dihydrogen phosphate (NaH ₂ PO ₄ ), monopotassium dihydrogen phosphate (KH ₂ PO ₄ ), monoammonium dihydrogen phosphate (NH ₄ H ₂ PO ₄₎ ), Orthophosphate such as dipotassium monohydrogen phosphate (K ₂ HPO ₄ ), diammonium monohydrogen phosphate ((NH ₄ ) ₂ HPO ₄ ); sodium phosphite (Na ₂ HPO ₃ ), phosphorous acid Phosphites such as potassium (K ₂ HPO ₃ ); sodium hypophosphite (NaH ₂ PO ₂ ), potassium hypophosphite (KH ₂ PO ₂ ), ammonium hypophosphite (NH ₄ H ₂ PO ₂ ) And other hypophosphites Among these, from the viewpoint of improving the polishing rate and reducing the surface roughness, disodium monohydrogen phosphate, dipotassium monohydrogen phosphate, sodium phosphite, sodium hypophosphite, diammonium monohydrogen phosphate One or more inorganic phosphate compounds selected from the group consisting of ((NH ₄ ) ₂ HPO ₄ ) and ammonium hypophosphite are preferred. These inorganic salts may have a hydrate structure.

The content of the inorganic phosphate compound (component G) contained in the polishing composition of the present invention is preferably 1 ppm by mass or more, more preferably 10 ppm by mass, from the viewpoint of improving the polishing rate and reducing the surface roughness. As mentioned above, More preferably, it is 100 mass ppm or more, More preferably, it is 200 mass ppm or more, More preferably, it is 500 mass ppm or more, More preferably, it is 800 ppm or more. In addition, the content of the inorganic phosphate compound (component G) contained in the polishing liquid composition of the present invention is preferably 5000 ppm by mass or less, from the viewpoint of reducing the surface roughness of the polished object. Preferably it is 4000 mass ppm or less, More preferably, it is 3000 mass ppm or less, More preferably, it is 2000 mass ppm or less.

Content ratio of alumina particles (component A) and inorganic phosphate compound (component G) in the polishing composition of the present invention [alumina particle content (ppm by mass) / inorganic phosphate compound content (Mass ppm)] is preferably 2 or more, more preferably 20 or more, still more preferably 100 or more, preferably 10,000 or less, more preferably 4000 or less, and still more preferably 1000 or less, from the viewpoint of reducing the surface roughness.

[Method for preparing polishing liquid composition]
The polishing liquid composition of this invention can be prepared by mixing each component by a well-known method. The polishing composition is usually produced as a concentrated solution from the viewpoint of economy, and it is often diluted at the time of use. The polishing composition may be used as it is, or diluted if it is a concentrated solution.

Next, an example of the method for producing a sapphire plate of the present invention using the polishing liquid composition of the present invention and an example of the method for polishing a polished sapphire plate of the present invention will be described.

[To be polished]
An example of a method for producing a sapphire plate of the present invention (sometimes abbreviated as “an example of a production method of the present invention”) and an example of a method for polishing a polished sapphire plate of the present invention (“of the polishing method of the present invention”). There is no particular limitation on the shape of the object to be polished in (In some cases, abbreviated as “example”). For example, not only the shape having a flat portion such as a disk shape, a plate shape, a slab shape, and a prism shape, The shape which has curved-surface parts, such as, may be sufficient. Moreover, although the said to-be-polished object is various, such as a sapphire board used as a cover glass of portable terminal devices, such as a smart phone, and a sapphire substrate for LED, the polishing liquid composition of this invention is a cover of the said portable terminal device especially. It is suitable as a polishing composition used in the polishing step of a method for producing a sapphire plate used as glass.

Therefore, an example of the manufacturing method of the sapphire plate of this invention is a manufacturing method of the sapphire plate for portable terminal devices, Comprising: The process of grind | polishing a to-be-polished sapphire board using the polishing liquid composition of this invention is included. Moreover, an example of the grinding | polishing method of the to-be-polished sapphire board of this invention is a grinding | polishing method of the sapphire board for portable terminal devices, Comprising: The process of grind | polishing to-be-polished sapphire board using the polishing liquid composition of this invention is included.

When the average particle size of the alumina particles contained in the polishing liquid composition of the present invention is small, for example, 0.2 μm or more and 1 μm or less, the polishing liquid composition of the present invention is a semiconductor that requires high smoothness. It is suitable as a polishing composition used in a polishing step of a method for producing a sapphire substrate for electronic parts such as an element and further a sapphire substrate for LED.

The step of polishing the sapphire plate to be polished includes a first polishing step (rough polishing step) for planarizing a wafer obtained by slicing a sapphire single crystal ingot into a thin disc shape, and after etching the rough polished wafer The polishing composition of the present invention can be used in both the first polishing step and the second polishing step, although it is divided into a second polishing step (finish polishing) for mirror-finishing the wafer surface. However, the polishing composition of the present invention is preferably used in the second polishing step from the viewpoint of improving the surface smoothness and productivity of the sapphire plate. In the first polishing step, it is common to use a polishing composition containing diamond as abrasive grains.

The polishing apparatus used in one example of the production method of the present invention and one example of the polishing method of the present invention is not particularly limited, and a jig (carrier: made of aramid, etc.) for holding the sapphire plate to be polished and a polishing cloth (polishing pad) Can be used, and may be either a double-side polishing apparatus or a single-side polishing apparatus.

The polishing pad is not particularly limited, and a conventionally known polishing pad can be used. Examples of the material for the polishing pad include organic polymers, and examples of the organic polymer include polyurethane. The shape of the polishing pad is preferably a nonwoven fabric. For example, SUBA800 (manufactured by Nitta Haas) is suitably used as the nonwoven fabric polishing pad.

In one example of the production method of the present invention and one example of the polishing method of the present invention using the polishing apparatus, the sapphire plate to be polished is sandwiched by a polishing surface plate that holds the sapphire plate to be polished by a carrier and has a polishing pad attached thereto. The polishing liquid composition of the invention is supplied between a polishing pad and a sapphire plate to be polished, and the polishing pad and / or the sapphire plate to be polished is moved while contacting the sapphire plate to be polished and the polishing pad. A step of polishing the polished sapphire plate.

Polishing load in an example of an example and a polishing method of the production method of the present invention, from the viewpoint of increasing the polishing rate, 50 g / cm ² or more is preferable, 100 g / cm ² or more, and more preferably from 150 g / cm ² or more, Even more preferably 200 g / cm ² or more. Further, the polishing load, device, considering the durability, such as pad, preferably 400 g / cm ² or less, 350 g / cm ² or less being more preferred. The polishing load can be adjusted by applying air pressure or weight to the surface plate or the polished sapphire plate. The polishing load means the pressure of the surface plate applied to the polishing surface of the polished sapphire plate during polishing.

The method of supplying the polishing liquid composition of the present invention is a method of supplying a polishing pad between a polishing pad and a sapphire plate to be polished by a pump or the like in a state where the constituents of the polishing liquid composition are sufficiently mixed in advance. For example, a method of mixing and supplying the above components can be used. A method of supplying a polishing liquid composition between a polishing pad and a sapphire plate to be polished with a pump or the like in a state where constituents of the polishing liquid composition are sufficiently mixed in advance from the viewpoint of improving the polishing rate and reducing the load on the apparatus Is preferred.

The supply rate of the polishing composition is preferably 20 mL / min or less, more preferably 10 mL / min or less, and even more preferably 5 mL / min or less per 1 cm ^{2 of the} polished sapphire plate from the viewpoint of cost reduction. The supply rate is preferably 0.01 mL / min or more, more preferably 0.1 mL / min or more, and further preferably 0.5 mL / min or more from 1 cm ^{2 of the} polished sapphire plate from the viewpoint of improving the polishing rate.

In one example of the production method of the present invention and one example of the polishing method of the present invention, since the polishing liquid composition of the present invention is used, the polishing rate of the polished sapphire plate is high, and the surface roughness of the substrate surface after polishing is increased. Can be reduced.

In another example of the production method of the present invention, a polishing liquid composition of the present invention is supplied to a polished sapphire plate to polish the polished sapphire plate, and the polishing liquid composition used in the step And polishing a polished sapphire plate different from the polished sapphire plate using an object. In such a production method of the present invention in which cyclic polishing is performed, the surface roughness is reduced by using the polishing liquid composition of the present invention, particularly a polishing liquid composition containing a compound having a sugar skeleton (component D). Can be manufactured with good productivity.

The present invention further discloses the following <1> to <33>.

<1> A polishing liquid composition for a sapphire plate containing alumina particles, an anionic polymer, and an aqueous medium.
<2> The polishing composition for a sapphire plate according to <1>, wherein the anionic polymer preferably includes a structural unit derived from (meth) acrylic acid, and more preferably includes a structural unit derived from acrylic acid.
<3> The proportion of structural units derived from (meth) acrylic acid in the total structural units of the anionic polymer is preferably 50 mol% or more, more preferably 60 mol% or more, still more preferably 70 mol% or more, The polishing composition for sapphire plates according to <2>, which is more preferably 90 mol% or more, still more preferably 95% or more, still more preferably 98 mol% or more, and even more preferably 100 mol%.
<4> The anionic polymer is preferably one or more anionic polymers selected from polyacrylic acid and (meth) acrylic acid / 2- (meth) acrylamide-2-methylpropanesulfonic acid copolymer, The polishing liquid composition for sapphire plates according to any one of <1> to <3>, which is more preferably polyacrylic acid.
<5> The weight average molecular weight of the anionic polymer is preferably 500 or more, more preferably 1000 or more, still more preferably 1500 or more, preferably 120,000 or less, more preferably 100,000 or less, and further preferably 30,000 or less. Preferably, 10,000 or less is still more preferable, and 8000 or less is still more preferable, The polishing liquid composition for sapphire plates in any one of <1> to <4>.
<6> The content of the anionic polymer in the polishing liquid composition for sapphire plate is preferably 1 ppm by mass or more, more preferably 10 ppm by mass or more, still more preferably 100 ppm by mass or more, and even more preferably 200 masses. <1> to <5>, which is at least ppm, preferably 5000 ppm by mass or less, more preferably 4000 ppm by mass or less, further preferably 3000 ppm by mass or less, and even more preferably 2000 ppm by mass or less. Polishing liquid composition for sapphire plates.
<7> Content ratio of the alumina particles and the anionic polymer in the polishing liquid composition for sapphire plate [alumina particle content (mass ppm) / anionic polymer content (mass ppm)] Is preferably 10 or more, more preferably 20 or more, still more preferably 50 or more, still more preferably 100 or more, preferably 200000 or less, more preferably 20000 or less, and even more preferably 2000 or less, from <1>. <6> The polishing composition for sapphire plates according to any one of the above.
<8> The polishing composition for sapphire plates according to any one of <1> to <7>, preferably further containing a sugar compound and / or a derivative thereof.
<9> The sugar compound and / or derivative thereof is preferably a sugar alcohol, a monosaccharide, or a disaccharide, and more preferably at least one compound selected from the group consisting of sorbitol, sucrose, galactose, and maltitol. The polishing composition for sapphire plates according to any one of <1> to <8>.
<10> The content of the sugar compound and / or derivative thereof in the sapphire plate polishing liquid composition is preferably 10 ppm by mass or more, more preferably 50 ppm by mass or more, still more preferably 100 ppm by mass or more, and even more. Preferably, it is 500 ppm by mass or more, preferably 10,000 ppm by mass or less, more preferably 5000 ppm by mass or less, still more preferably 3000 ppm by mass or less, and even more preferably 1000 ppm by mass or less. <1> to <9> The polishing liquid composition for sapphire boards in any one of.
<11> Content ratio of the anionic polymer and the sugar compound and / or derivative thereof in the polishing liquid composition for sapphire plate [content (mass ppm) of the sugar compound and / or derivative thereof / anionic high The molecular content (mass ppm)] is preferably 0.01 or more, more preferably 0.1 or more, still more preferably 0.5 or more, still more preferably 1 or more, preferably 5000 or less, more preferably 1000. Hereinafter, the polishing composition for a sapphire plate according to any one of <1> to <10>, which is more preferably 100 or less, and still more preferably 50 or less.
<12> The polishing composition for sapphire plates according to any one of <1> to <11>, preferably further containing an oxidizing agent.
<13> The polishing composition for sapphire plates according to any one of <1> to <12>, preferably further containing an acid.
<14> The polishing composition for sapphire plates according to <13>, wherein the acid preferably contains an organic acid and an inorganic acid.
<15> The polishing composition for sapphire plates according to <14>, wherein the organic acid is preferably citric acid and the inorganic acid is sulfuric acid.
<16> The polishing composition for sapphire plates according to any one of <1> to <15>, preferably further containing an inorganic phosphate compound.
<17> The inorganic phosphate compound is preferably at least one inorganic phosphate compound selected from the group consisting of orthophosphate, phosphite, and hypophosphite, more preferably orthophosphate. And the polishing composition for sapphire plates according to <16>, which is one or more inorganic phosphate compounds selected from the group consisting of phosphites and phosphites.
<18> The inorganic phosphate compound is preferably one or more of alkali metal salts, alkaline earth metal salts, and ammonium salts, more preferably sodium salts, potassium salts, and ammonium salts. The polishing liquid composition for sapphire plates according to <16> or <17>, which is at least one selected from:
<19> The inorganic phosphate compound is preferably sodium phosphate (Na ₃ PO ₄ ), potassium phosphate (K ₃ PO ₄ ), disodium monohydrogen phosphate (Na ₂ HPO ₄ ), diphosphate phosphate. Monosodium hydrogen (NaH ₂ PO ₄ ), monopotassium dihydrogen phosphate (KH ₂ PO ₄ ), monoammonium dihydrogen phosphate (NH ₄ H ₂ PO ₄ ), dipotassium monohydrogen phosphate (K ₂ HPO ₄ ) Diammonium monohydrogen phosphate ((NH ₄ ) ₂ HPO ₄ ), sodium phosphite (Na ₂ HPO ₃ ), potassium phosphite (K ₂ HPO ₃ ), sodium hypophosphite (NaH ₂ PO ₂ ) One or more inorganic phosphate compounds selected from the group consisting of potassium hypophosphite (KH ₂ PO ₂ ) and ammonium hypophosphite (NH ₄ H ₂ PO ₂ ), more preferably dihydrogen phosphate Sodium, phosphorus <16> which is at least one inorganic phosphate compound selected from the group consisting of dipotassium hydrogen monohydrogen, sodium phosphite, sodium hypophosphite, diammonium monohydrogen phosphate, and ammonium hypophosphite. To <18> The polishing liquid composition for sapphire plates according to any one of items.
<20> The content of the inorganic phosphate compound (component G) in the polishing composition for a sapphire plate is preferably 1 mass ppm or more, more preferably 10 mass ppm or more, still more preferably 100 mass ppm or more. More preferably 200 mass ppm or more, still more preferably 500 mass ppm or more, still more preferably 800 ppm or more, preferably 5000 mass ppm or less, more preferably 4000 mass ppm or less, still more preferably 3000 mass ppm or less, More preferably, it is 2000 mass ppm or less, The polishing liquid composition for sapphire plates in any one of <16> to <19>.
<21> Content ratio of alumina particles (component A) and inorganic phosphate compound (component G) in the polishing composition for sapphire plate [alumina particle content (ppm by mass) / inorganic phosphate compound Content (mass ppm)] is preferably 2 or more, more preferably 20 or more, still more preferably 100 or more, preferably 10,000 or less, more preferably 4000 or less, and even more preferably 1000 or less, from <16> to <20 > The polishing liquid composition for sapphire plates in any one of.
<22> The pH at 25 ° C. of the polishing composition for sapphire plates is preferably 10 or more, more preferably 11 or more, and preferably less than 14, according to any one of <1> to <21>. Polishing liquid composition for sapphire plates.
<23> The average particle diameter of the alumina particles measured by the dynamic light scattering method is preferably 0.2 μm or more, more preferably 0.25 μm or more, still more preferably 0.3 μm or more, and even more preferably 0.00. Any one of <1> to <22>, which is 35 μm or more, preferably 1.0 μm or less, more preferably 0.95 μm or less, still more preferably 0.90 μm or less, and even more preferably 0.80 μm or less. The polishing liquid composition for sapphire plates as described.
<24> The content of alumina particles in the polishing composition for sapphire plate is preferably 3% by mass or more, more preferably 5% by mass or more, still more preferably 7% by mass or more, and even more preferably 10% by mass or more. Preferably, it is 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, and even more preferably 20% by mass or less, according to any one of <1> to <23>. Polishing liquid composition for sapphire plates.
<25> A polishing composition for a sapphire plate, containing alumina particles, a rheology modifier, and an aqueous medium.
<26> The sapphire plate according to <25>, wherein the rheology modifier is an anionic polymer, preferably includes a structural unit derived from (meth) acrylic acid, and more preferably includes a structural unit derived from acrylic acid. Polishing liquid composition.
<27> The polishing composition for sapphire plates according to <25> or <26>, preferably further containing a compound having a sugar skeleton.
<28> The polishing composition for sapphire plates according to any one of <25> to <27>, preferably further containing an inorganic phosphate compound.
<29> The shear viscosity (Pa · s) at a shear rate of 100 (1 / s) of the polishing composition for a sapphire plate at 25 ° C. measured in an environment of 25 ° C. and 50% RH is preferably 0.00. 01 (Pa · s) or less, more preferably 0.008 (Pa · s) or less, still more preferably 0.007 (Pa · s) or less, preferably 0.001 (Pa · s) or more, more preferably Is a polishing liquid composition for sapphire plates according to any one of <1> to <28>, which is 0.0015 (Pa · s) or more, more preferably 0.002 (Pa · s) or more.
<30> The shear viscosity ratio calculated by the following formula is preferably 0.6 or less, more preferably 0.4 or less, still more preferably 0.3 or less, preferably 0.01 or more, more preferably 0. The polishing composition for sapphire plates according to any one of <1> to <29>, which is 0.05 or more, more preferably 0.1 or more.
Shear viscosity ratio = (Shear viscosity at a shear rate of 100 (1 / s) of the polishing composition) / (Shear rate of a polishing composition having the same composition as the polishing composition except that it does not contain a rheology modifier) Shear viscosity at 100 (1 / s))
<31> A sapphire plate comprising a step of supplying the polishing composition for a sapphire plate according to any one of <1> to <30> to polish the sapphire plate to be polished. Production method.
<32> A step of supplying the polishing composition for a sapphire plate according to any one of <1> to <30> to polish the sapphire plate to be polished,
A step of polishing a polished sapphire plate different from the polished sapphire plate using the polishing liquid composition for sapphire plate used in the step.
<33> A sapphire to be polished comprising a step of supplying the polishing composition for a sapphire plate according to any one of <1> to <30> and polishing the sapphire plate to be polished to a sapphire plate to be polished. A method for polishing a plate.

The polishing compositions of Examples 1 to 50 and Comparative Examples 1 to 7 were prepared as follows. The contents of the particles, the anionic polymer, the compound having a sugar skeleton, the inorganic phosphate compound, and the oxidizing agent in the polishing liquid compositions of Examples 1 to 50 and Comparative Examples 1 to 7 are shown in Tables 1 to 4 as described. The solubility of the anionic polymer used in the preparation of the polishing composition of Examples 1 to 50 and Comparative Examples 1 to 7 in water at 20 ° C. was 2 g / 100 ml or more.

The details of each component used for the preparation of the polishing liquid compositions of Examples 1 to 50 and Comparative Examples 1 to 7 are as follows.
[Anionic polymer]
(1) Polyacrylic acid (weight average molecular weight: 6000, POIZ (registered trademark) 530, manufactured by Kao Corporation)
(2) Acrylic acid / 2-acrylamido-2-methylpropanesulfonic acid copolymer (80 mol% acrylic acid, 20 mol% 2-acrylamido-2-methylpropanesulfonic acid, weight average molecular weight 2000, 40 mass% aqueous solution, Toagosei Co., Ltd., Aron (registered trademark) A-6016)
[Compound having a sugar skeleton]
(1) D (+)-glucose (manufactured by Wako Pure Chemical Industries, Ltd.)
(2) D (+)-galactose (manufactured by Wako Pure Chemical Industries, Ltd.)
(3) D (+)-xylose (manufactured by Wako Pure Chemical Industries, Ltd.)
(4) L (+)-arabinose (Wako Pure Chemical Industries)
(5) D-erythrose (manufactured by Wako Pure Chemical Industries, Ltd.)
(6) D (-)-fructose (Wako Pure Chemical Industries, Ltd.)
(7) D-xylulose (manufactured by Sigma Aldrich Japan)
(8) D-erythrulose (manufactured by Carbosynth Limited)
(9) D (-)-sorbitol (Wako Pure Chemical Industries)
(10) Xylitol (Wako Pure Chemical Industries, Ltd.)
(11) D (-)-mannitol (Wako Pure Chemical Industries, Ltd.)
(12) Maltitol (manufactured by Tokyo Chemical Industry Co., Ltd.)
(13) Maltose monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.)
(14) Sucrose (Wako Pure Chemical Industries)

<Examples 1 to 5>
After adding polyacrylic acid as an anionic polymer into a beaker containing ion-exchanged water, 45 mass% alumina particles (abrasive grains, 90% alpha conversion rate, crystallite size 32 nm) in water dispersion are added. Was stirred to obtain an aqueous dispersion of an anionic polymer-added alumina particle. Immediately thereafter, the pH of the aqueous dispersion of the anionic polymer-added alumina particles was adjusted to 13 using a 48 mass% aqueous sodium hydroxide solution (manufactured by Kanto Chemical Co., Inc.) to obtain a polishing composition. The average particle diameters of the alumina particles used in the preparation of Examples 1 to 5 were as shown in Table 1, respectively. In Table 1, except for Comparative Example 1, alumina particles were used as abrasive grains.

<Examples 6 to 19>
After adding polyacrylic acid as an anionic polymer into a beaker containing ion-exchanged water, a compound having a sugar skeleton was added. Thereafter, an aqueous dispersion of 45% by mass alumina particles (abrasive grains, 90% gelatinization rate, crystallite size 32 nm) was added and stirred to obtain an aqueous dispersion of anionic polymer-added alumina particles. Immediately thereafter, the pH of the aqueous dispersion of the anionic polymer-added alumina particles was adjusted to 13 using a 48% by mass aqueous sodium hydroxide solution (manufactured by Kanto Chemical Co., Inc.) to obtain the polishing liquid compositions of Examples 6-19. It was.

<Examples 20 to 22>
Polishing liquid compositions of Examples 20 to 22 were prepared in the same manner as in Example 14 except that the content of the compound having a sugar skeleton was different.

<Examples 23 and 24>
The polishing liquid compositions of Examples 23 and 24 were prepared in the same manner as in Example 14 except that the content of abrasive grains (alumina particles) was different.

<Example 25>
A polishing composition of Example 25 was prepared in the same manner as Example 14 except that the content of the anionic polymer (polyacrylic acid) was different.

<Example 26>
The polishing liquid composition of Example 26 was the same as Example 14 except that the amount of 48 mass% sodium hydroxide aqueous solution (manufactured by Kanto Chemical Co., Inc.) was different and the polishing composition had a pH of 11 at 25 ° C. A product was prepared.

<Example 27>
A polishing composition of Example 27 was prepared in the same manner as in Example 4 except that the anionic polymer was AA-AMPS (Aron (registered trademark) A-6012, manufactured by Toa Gosei Co., Ltd.).

<Examples 28 to 31>
Polishing of Examples 28 to 31 was carried out in the same manner as in Examples 14, 19, 7, and 17, except that the anionic polymer was AA-AMPS (Aron (registered trademark) A-6012, manufactured by Toa Gosei Co., Ltd.). A liquid composition was prepared.

<Examples 32 and 33>
Polishing liquid compositions of Examples 32 and 33 were prepared in the same manner as Example 14 except that Na phosphite was further included as the inorganic phosphate compound.

<Example 34>
A polishing composition of Example 34 was prepared in the same manner as Example 19 except that Na phosphite was further included as an inorganic phosphate compound.

<Examples 35 to 39>
Polishing liquid compositions of Examples 35 to 39 were prepared in the same manner as in Example 33 except that the types of inorganic phosphate compounds were different.

<Example 40>
A polishing liquid composition of Example 40 was prepared in the same manner as in Example 34 except that the anionic polymer was AA-AMPS (Aron (registered trademark) A-6012, manufactured by Toa Gosei Co., Ltd.).

<Examples 41 and 42>
The polishing composition of Examples 41 and 42 was prepared in the same manner as in Examples 33 and 40 except that the compound having a sugar skeleton was not included.

<Examples 43 and 44>
After adding polyacrylic acid as an anionic polymer in a beaker containing ion-exchanged water, add 35% by mass hydrogen peroxide (concentration adjusted by diluting a reagent manufactured by Wako Pure Chemical Industries, Ltd.) did. Thereafter, an aqueous dispersion of 45% by mass alumina particles (abrasive grains, 90% gelatinization rate, crystallite size 32 nm) was added, and sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd.) diluted to 62.5% by mass with water was used. The pH was adjusted to 1.9 to obtain a polishing composition of Example 43. In Example 44, instead of diluting sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd.) to 62.5% by mass with water, the citric acid concentration of the system was 0.4% by mass in a beaker containing ion-exchanged water. A 50% by mass aqueous citric acid solution was added, and a solution obtained by diluting sulfuric acid to 62.5% by mass with water was added to adjust the pH to 1.9. Except this, the polishing composition of Example 44 was obtained in the same manner as in Example 43.

<Example 45>
In a beaker containing ion-exchanged water, polyacrylic acid is added as an anionic polymer, sorbitol (manufactured by Wako Pure Chemical Industries, Ltd.) is added as a compound having a sugar skeleton, and a 35% by mass hydrogen peroxide solution is added. (Wako Pure Chemical Industries, Ltd. reagent diluted with water to adjust the concentration) was added. Thereafter, an aqueous dispersion of 45% by mass alumina particles (abrasive grains, 90% alpha conversion, crystallite size 32 nm) was added, and the pH was adjusted to 1.9 using sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd.). The polishing liquid composition of Example 45 was obtained.

<Example 46>
A polishing composition of Example 46 was prepared in the same manner as Example 45 except that Na phosphite was further included as the inorganic phosphate compound.

<Example 47>
A polishing liquid composition of Example 47 was prepared in the same manner as in Example 46 except that the compound having a sugar skeleton was not included.

<Examples 48 and 49>
The polishing liquid compositions of Examples 48 and 49 were prepared in the same manner as in Examples 43 and 44 except that the anionic polymer was AA-AMPS (Aron (registered trademark) A-6012, manufactured by Toa Gosei Co., Ltd.). Prepared.

<Example 50>
A polishing liquid composition of Example 50 was prepared in the same manner as Example 47 except that the anionic polymer was AA-AMPS (Aron (registered trademark) A-6012, manufactured by Toa Gosei Co., Ltd.).

<Comparative Example 1>
In a beaker containing ion-exchanged water, a colloidal silica aqueous dispersion (average particle size 80 nm) and a 48% by mass aqueous sodium hydroxide solution (manufactured by Kanto Chemical Co., Inc.) were added and stirred, and the pH was 10.6 A polishing liquid composition of Comparative Example 1 was prepared.

<Comparative example 2>
A polishing liquid composition of Comparative Example 2 was prepared in the same manner as in Example 4 except that the anionic polymer was not added.

<Comparative Examples 3 and 4>
A polishing composition of Comparative Examples 3 and 4 was prepared in the same manner as in Examples 14 and 19 except that the anionic polymer was not added.

<Comparative Example 5>
A polishing composition of Comparative Example 5 was prepared in the same manner as in Example 43 except that the anionic polymer was not added.

<Comparative Example 6>
A polishing composition of Comparative Example 6 was prepared in the same manner as in Example 45 except that the anionic polymer was not added.

<Comparative Example 7>
A polishing composition of Comparative Example 7 was prepared in the same manner as Comparative Example 6 except that sucrose was used in place of sorbitol as the compound having a sugar skeleton.

[Method of measuring volume average particle diameter (D50) of alumina particles]
The average particle diameter of alumina particles (abrasive grains) in the polishing compositions of Examples 1 to 50 and Comparative Examples 2 to 7 was 0.5% poise 530 (manufactured by Kao Corporation; special polycarboxylic acid type polymer surfactant) ) Using an aqueous solution as a dispersion medium, the sample was introduced into the following measuring apparatus, and then a sample was introduced so that the transmittance was 75 to 95%. After that, ultrasonic waves were applied for 5 minutes, and the particle size was measured.
Measuring equipment: Laser diffraction / scattering type particle size distribution measuring instrument LA920 manufactured by HORIBA, Ltd.
Circulation strength: 4
Ultrasonic intensity: 4
The particle diameter at which the cumulative volume frequency of the obtained volume distribution particle diameter is 50% is defined as the volume average particle diameter (D50) of alumina particles, and is shown in Tables 1 to 4.

[Measurement method of alumina particle alpha ratio and crystallite size]
20 g of alumina slurry was dried at 105 ° C. for 5 hours, and the resulting dried product was crushed with a mortar to obtain a powder X-ray diffraction sample. Each sample was analyzed by the powder X-ray diffraction method, and the peak areas on the 104th surface were compared. The measurement conditions by the powder X-ray diffraction method were as follows.
Measurement condition;
Apparatus: Rigaku Co., Ltd., powder X-ray analyzer RINT2500VC
X-ray generation voltage: 40 kV
Radiation: Cu-Kα1 line (λ = 0.154050 nm)
Current: 120 mA
Scan Speed: 10 degrees / minute Measurement step: 0.02 degrees / minute pregelatinization rate (%) = alpha alumina specific peak area ÷ WA−1000 peak area × 100
The crystallite size was calculated from the obtained powder X-ray diffraction spectrum using the powder X-ray diffraction pattern comprehensive analysis software JADE (MDI, automatically calculated by Scherrer's equation) attached to the powder X-ray diffractometer. The calculation process by the software was calculated based on the instruction manual of the software (Jade (Ver. 5) software, instruction manual Manual No. MJ13133E02, Rigaku Corporation).

[Measurement of average particle size of colloidal silica]
The average particle size (dispersed particle size) of colloidal silica (abrasive grains) in the polishing composition of Comparative Example 1 is a dynamic light scattering (DLS) particle size distribution meter (Zetasizer (registered trademark) Nano S, manufactured by Malvern). The volume-converted average particle size obtained was determined as the average particle size (dispersed particle size).
Solvent: water (refractive index 1.333)
Abrasive grain: colloidal silica (refractive index 1.45, attenuation coefficient 0.02)
Measurement temperature: 25 ° C

[Measurement of pH of polishing composition]
The pH of the polishing composition was measured at 25 ° C. using a pH meter (manufactured by Toa Denpa Kogyo Co., Ltd., HM-30G).

[Polishing evaluation]
A 3-inch sapphire plate (c surface) was polished for 1 hour under the following polishing conditions using the polishing liquid compositions of Examples 1 to 50 and Comparative Examples 1 to 7. And the weight change before and behind grinding | polishing of a sapphire board was calculated | required, and polishing rate X (micrometer / h) was computed from the sapphire density (3.98g / cm < ³ >) and the sapphire board area (45.6cm < ² >). The polishing rate X when using the polishing liquid compositions of Examples 1 to 50 and Comparative Examples 2 to 7 is the same as that when the polishing rate X when using the polishing liquid composition of Comparative Example 1 was “100”. The relative values are shown in Tables 1 and 2. The polishing rates listed in Tables 3 and 4 are relative values when the polishing rate X when the polishing liquid compositions of Comparative Example 2 and Comparative Example 5 are used is “100”, respectively.

Further, polishing was performed for 1 hour (first polishing) on the 3-inch sapphire plate (c surface) using the polishing liquid compositions of Examples 1 to 50 and Comparative Examples 1 to 7 under the following polishing conditions. Then, using the used polishing composition used for the polishing, another 3 inch sapphire plate (c surface) is polished for 1 hour under the following polishing conditions (second polishing), and polished. The speed ratio (polishing speed of the second polishing / polishing speed of the first polishing × 100) is shown in Tables 1 and 2 as polishing durability. The closer the polishing rate ratio is to “100”, the better the polishing durability of the polishing composition. The sapphire plate was polished under the following polishing conditions, then immersed in ultrapure water, then rinsed with running water (ultrapure water) and dried.

(Polishing conditions)
Single-side polishing machine (Technolize TR15M-TRK1, platen diameter 38cm)
Nonwoven polishing pad (Nitta Haas SUBA800)
Polishing load 300g / cm ²
Plate rotation speed 120rpm
Carrier rotation speed 120rpm
Polishing fluid flow rate 80mL / min (circulation)

[Measurement method of surface roughness]
Using an AFM (Digital Instrument NanoScope IIIa Multi Mode AFM), the center part of the inner and outer edges of the sapphire plate after cleaning was measured one by one on the front and back sides under the following conditions, and the centerline average roughness AFM- Ra was measured. The average value of the two points was defined as “surface roughness”. The surface roughness when the polishing liquid compositions of Examples 1 to 50 and Comparative Examples 2 to 7 are used is the surface roughness when the polishing liquid composition of Comparative Example 1 is used as “100”. The relative values are shown in Tables 1 and 2. The surface roughnesses shown in Tables 3 and 4 are relative values when the polishing rate X when the polishing liquid compositions of Comparative Example 2 and Comparative Example 5 are used is “100”, respectively. It shows that the deterioration of surface roughness is suppressed, so that a value is small.
[AFM measurement conditions]
Mode: Tapping mode
Area: 1 × 1μm
Scan rate: 1.0 Hz
Cantilever: NCH-10V
Line: 512 × 512

[Measurement method of shear viscosity by rotary rheometer]
The viscosity of the polishing composition at 25 ° C. was measured in an environment of 25 ° C. and 50% RH using a viscoelasticity measuring device (manufactured by Anton Paar, Physica MCR301). Specifically, parallel plates (PP75, φ75 mm) are used, the gap between the parallel plates is 100 μm, one of the plates is rotated, and the shear rate is from 1 (1 / s) to 10000 (1 / s) Then, the pressure is gradually lowered from 10000 (1 / s) to 1 (1 / s), and the shear viscosity at 100 (1 / s) when the shear rate is lowered is taken as a measurement result. It is shown in Table 4. The shear viscosity ratio calculated by the following formula is also shown in Tables 3 and 4.
Shear viscosity ratio = (Shear viscosity at a shear rate of 100 (1 / s) of the polishing composition) / (Shear rate of a polishing composition having the same composition as the polishing composition except that it does not contain a rheology modifier) Shear viscosity at 100 (1 / s))

As shown in Tables 1 and 2, when comparing the examples and comparative examples for the alkaline polishing composition and the acid polishing composition, respectively, when the polishing composition of the example was used, the comparative example As compared with the case of using the above polishing liquid composition, the polishing rate 1 hour after the start of polishing is high, the surface roughness is small, and the deterioration with time of the polishing rate is suppressed. Further, as shown in Tables 3 and 4, the shear viscosity of the polishing liquid compositions of the examples is significantly smaller than the shear viscosity of the polishing liquid compositions of the comparative examples, and in particular, anionic polymers and sugar skeletons. The shear viscosity of the polishing composition of the example in combination with the compound having the is even smaller.

As described above, in the polishing of the sapphire plate to be polished using the polishing liquid composition of the present invention, the polishing rate is fast, the surface roughness of the surface of the sapphire plate after polishing is reduced, and the polishing rate over time Deterioration is suppressed. Therefore, if the polishing liquid composition of this invention is used, the productivity of the sapphire plate used as a cover glass of portable terminal devices, such as a smart phone, will improve.

Claims (18)

1. Polishing liquid composition for sapphire plates containing alumina particles, anionic polymer, and aqueous medium.
2. The polishing composition for a sapphire plate according to claim 1, wherein the anionic polymer contains a structural unit derived from acrylic acid.
3. The polishing composition for sapphire plates according to claim 1 or 2, further comprising a compound having a sugar skeleton.
4. The polishing composition for sapphire plates according to any one of claims 1 to 3, further comprising an inorganic phosphate compound.
5. The sapphire plate according to claim 4, wherein the inorganic phosphate compound is one or more inorganic phosphate compounds selected from the group consisting of orthophosphate, phosphite, and hypophosphite. Polishing liquid composition.
6. The polishing liquid composition for sapphire plates according to claim 4 or 5, wherein the inorganic phosphate compound is one or more of alkali metal salts, alkaline earth metal salts, and ammonium salts. object.
7. The polishing composition for a sapphire plate according to any one of claims 1 to 6, further comprising an oxidizing agent.
8. The polishing composition for sapphire plates according to any one of claims 1 to 7, further comprising an acid.
9. The polishing composition for a sapphire plate according to claim 8, wherein the acid comprises an organic acid and an inorganic acid.
10. The polishing composition for sapphire plates according to any one of claims 1 to 9, wherein the pH of the polishing composition for sapphire plates at 25 ° C is 10 or more and less than 14.
11. The polishing composition for a sapphire plate according to any one of claims 1 to 10, wherein an average particle diameter of the alumina particles measured by a dynamic light scattering method is 0.2 µm or more and 1.0 µm or less.
12. A polishing composition for a sapphire plate containing alumina particles, a rheology modifier, and an aqueous medium.
13. The polishing composition for sapphire plates according to claim 12, wherein the rheology modifier is an anionic polymer and contains a structural unit derived from acrylic acid.
14. The polishing composition for sapphire plates according to claim 12 or 13, further comprising a compound having a sugar skeleton.
15. The polishing composition for sapphire plates according to any one of claims 12 to 14, further comprising an inorganic phosphate compound.
16. The manufacturing method of a sapphire board including the process of supplying the polishing liquid composition for sapphire boards in any one of Claims 1-15 with respect to a to-be-polished sapphire board, and grind | polishing the said to-be-polished sapphire board.
17. A step of supplying the polishing composition for a sapphire plate according to any one of claims 1 to 15 to polish the sapphire plate to be polished,
    A step of polishing a polished sapphire plate different from the polished sapphire plate using the polishing liquid composition for sapphire plate used in the step.
18. Polishing of a to-be-polished sapphire plate, comprising a step of supplying the polishing composition for a sapphire plate according to any one of claims 1 to 15 to polish the to-be-polished sapphire plate. Method.