JP2009091197A - Warty-surfaced sphere-form inorganic oxide sol, method for producing same, and abrasive containing the sol - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a warty-surfaced sphere-form inorganic oxide sol composed of a solvent and fine microspherical inorganic oxide particles dispersed therein and being in a peculiar form, i.e., a warty-surfaced sphere-form. <P>SOLUTION: The warty-surfaced sphere-form inorganic oxide sol is composed of a solvent and warty-surfaced sphere-form fine inorganic oxide particles being fine spherical inorganic oxide particles having warty protrusions on their surfaces and dispersed therein and satisfying (a) a sphericity in the range of 0.8-1, (b) a surface roughness (SA1)/(SA2) of a value in the range of 1.20-1.70 (wherein (SA1) is the specific surface area as measured by a sodium titration method, and (SA2) is the specific surface area calculated from an average particle diameter (D2) as measured by an image analysis method), and (c) the average particle diameter (D2) as measured by the image analysis method in the range of 10-60 nm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inorganic oxide sol in which inorganic oxide fine particles having a unique shape such as confetti are dispersed in a solvent and a method for producing the same. In addition to the application to paint additives, resin additives, ink receiving layer components, cosmetic components, etc., the gold plain sugar-like inorganic oxide sol of the present invention is particularly useful in the field of abrasives and the field of aggregation accelerators. Is.

  In the manufacture of a substrate with a semiconductor integrated circuit, irregularities or steps are formed when forming a circuit with a metal such as copper on a silicon wafer. Removal is performed preferentially. Further, when an aluminum wiring is formed on a silicon wafer and an oxide film such as silica is provided thereon as an insulating film, irregularities due to the wiring are generated. Therefore, the oxide film is polished and flattened. In the polishing of such a substrate, the surface after polishing is required to be flat with no steps or irregularities, smooth without microscopic scratches, etc., and the polishing rate must be high.

In addition, semiconductor materials are becoming more highly integrated as electrical and electronic products become smaller and higher in performance. For example, when impurities such as Na and K remain in the transistor isolation layer, the performance is not exhibited. Or cause malfunctions. In particular, if Na adheres to the polished semiconductor substrate or oxide film surface, Na is highly diffusive and is trapped by defects in the oxide film, causing insulation failure even when a circuit is formed on the semiconductor substrate, or shorting the circuit. In some cases, the dielectric constant may decrease. For this reason, since the said malfunction may arise depending on use conditions or when used over a long term, the abrasive | polishing particle | grains which hardly contain impurities, such as Na and K, are calculated | required.
Conventionally, silica sol, fumed silica, fumed alumina, or the like is used as the abrasive particles.

  The abrasive used in CMP is usually spherical abrasive particles having an average particle diameter of about 200 nm made of a metal oxide such as silica and alumina, and an oxidizer for increasing the polishing rate of the wiring / circuit metal. It is composed of additives such as organic acids and solvents such as pure water, but there are steps (unevenness) due to the groove pattern for wiring formed on the underlying insulating film on the surface of the material to be polished. It is required to polish the coplanar surface while polishing and removing the convex portions to obtain a flat polished surface. However, with conventional spherical abrasive particles, when the portion above the coplanar surface is polished, the circuit metal in the wiring trench at the bottom of the recess is polished to below the coplanar surface (called dishing) There was.) If such dishing (overpolishing) occurs, the thickness of the wiring decreases and the wiring resistance increases, and the flatness of the insulating film formed thereon deteriorates. There is a need to suppress it.

  Abrasives containing irregularly shaped particles are used in polishing a substrate having such irregularities, and polishing of the concave portion is suppressed until the upper end surface of the convex portion is at the same level as the bottom surface of the concave portion, and the upper end surface of the convex portion is concave. After polishing to the same level as the bottom surface, both the convex and concave portions can be polished at the same polishing rate, so dishing (overpolishing) does not occur, and the polished surface has no unevenness and is excellent in flatness. It has been. For example, since dishing does not occur during polishing in the formation of semiconductor integrated circuits, etc., without increasing the circuit resistance of the obtained integrated circuit, the surface after polishing is excellent in flatness, so that stacking can be performed efficiently. A circuit can be formed.

  In addition, the abrasives containing such irregularly shaped particles include aluminum disks (aluminum or a plating layer on a base material thereof), aluminum wiring of a semiconductor multilayer wiring board, glass substrates for optical disks and magnetic disks, and liquid crystal displays. Application to glass substrates, glass substrates for photomasks, mirror finishing of glassy materials, and the like is expected.

As a method for producing a silica sol containing irregularly shaped particles, Japanese Patent Application Laid-Open No. 1-317115 (Patent Document 1) describes the measurement particle diameter (D ₁ ) obtained by an image analysis method and the measurement particle diameter (D ₂ ) obtained by a nitrogen gas adsorption method. and the ratio D ₁ / D ₂ is 5 or more, D ₁ is elongated having an elongation of only one plane in a uniform thickness in the range of 40 to 500 millimicrons and from 5 to 40 millimicrons by electron microscopy, As a method for producing a silica sol in which amorphous colloidal silica particles having a shape are dispersed in a liquid medium, (a) an aqueous solution containing a water-soluble calcium salt or magnesium salt in a predetermined colloidal aqueous solution of active silicic acid, was added a predetermined amount, the step of mixing, (b) further, alkali metal oxide, water-soluble organic base or their water-soluble silicate SiO ₂ / M ₂ O (where, M is the alkali metal atom or A step of adding and mixing so that the molar ratio is 20 to 200, and (c) a step of heating the mixture obtained in the previous step at 60 to 150 ° C. for 0.5 to 40 hours. A manufacturing method is disclosed.

The JP-A 4-65314 (Patent Document 2), particle diameter measured by the image analysis method (D ₁ millimicron) and particle diameter measured by a nitrogen gas adsorption method (D ₂ millimicrons) the ratio D ₁ / D ₂ Is less than 3 and less than 5, and this D ₁ is 40 to 500 millimicrons, and is uniform within one plane with a uniform thickness larger than 5 millimicrons but less than 100 millimicrons by electron microscopy. As a method for producing a stable silica sol having a SiO ₂ concentration of 50% by mass or less, in which elongated amorphous colloidal silica particles having an elongation of 1 are dispersed in a liquid medium, an aqueous solution of active silicic acid is added to the elongated silica sol. When starting, the colloidal silica particles of the raw material sol do not collapse, and the added active silicic acid is deposited on the surface of the original elongated particles through siloxane bonds. Colloidal silica thickness increased elongated shape are disclosed for the resulting.

The JP-A 4-187512 (Patent Document 3), the alkali metal silicate aqueous solution 0.05～5.0Wt% as _{SiO 2, SiO 2 / M 2} O of the mixture by adding silicic acid solution ( (Molar ratio: M is alkali metal or quaternary ammonium) 30-60, then selected from the group consisting of Ca, Mg, Al, In, Ti, Zr, Sn, Si, Sb, Fe, Cu and rare earth metals 1 type or 2 or more types of metal compounds are added (the timing of addition may be before or during addition of the silicic acid solution), and this mixed solution is maintained at an arbitrary temperature of 60 ° C. or higher for a certain period of time. A method for producing a sol in which silica particles having a substantially chain shape, in which a silicic acid solution is added and SiO ₂ / M ₂ O (molar ratio) in the reaction solution is set to 60 to 100, is dispersed is disclosed.

  In Japanese Patent No. 3441142 (Patent Document 4), the total number of colloidal silica particles having a major axis of 7 to 1000 nm and a minor axis / major axis ratio of 0.3 to 0.8 determined by image analysis of an electron micrograph is described. A semiconductor wafer abrasive comprising a stable sol of silica occupying 50% or more of the particles has been proposed.

In JP-A-7-118008 (Patent Document 5), an aqueous solution of a water-soluble calcium salt, magnesium salt or a mixture thereof is added to an aqueous colloidal solution of active silicic acid, and an alkaline substance is added to the obtained aqueous solution. A part of the obtained mixture is heated to 60 ° C. or more to obtain a heel liquid, the remainder is used as a feed liquid, the feed liquid is added to the heel liquid, and water is evaporated during the addition to evaporate SiO _2. A method for producing an elongated silica sol comprising concentrating to a concentration of 6 to 30% by mass is disclosed.

In JP-A-8-279480 (Patent Document 6), (1) a method in which an alkali silicate aqueous solution is neutralized with mineral acid, an alkaline substance is added and heat-aged, and (2) the alkali silicate aqueous solution is subjected to cation exchange treatment. A method of heating and aging by adding an alkaline substance to the obtained active silicic acid, (3) a method of heating and aging the active silicic acid obtained by hydrolyzing alkoxysilane such as ethyl silicate, or (4) fine silica powder Colloidal silica aqueous solution produced by, for example, a method of directly dispersing in an aqueous medium usually contains colloidal silica particles having a particle diameter of 4 to 1,000 nm (nanometer), preferably 7 to 500 nm. is obtained by dispersing 0.5 to 50% by mass as SiO _2, preferably has a concentration of 0.5 to 30 mass%. It is described that the particle shape of the silica particles includes a spherical shape, a distorted shape, a flat shape, a plate shape, an elongated shape, and a fibrous shape.

  Japanese Patent Laid-Open No. 11-214338 (Patent Document 7) discloses a silicon wafer polishing method using an abrasive mainly composed of colloidal silica particles, in which methyl silicate purified by distillation is converted into ammonia or methanol in a methanol solvent. A method for polishing a silicon wafer, characterized by using colloidal silica particles obtained by reacting with ammonia and ammonium salt as a catalyst, and having a major axis / minor axis ratio of 1.4 or more. Has been proposed.

International Publication No. WO00 / 15552 (Patent Document 8) is composed of spherical colloidal silica particles having an average particle diameter of 10 to 80 nm and metal oxide-containing silica that joins the spherical colloidal silica particles. The ratio D ₁ / D _{2 of} D ₁ ) to the average particle diameter of spherical colloidal silica particles (measured particle diameter by sodium titration method / D ₂ ) is 3 or more, and this D ₁ is 50 to 500 nm. A silica sol is described in which beaded colloidal silica particles in which silica particles are connected only in one plane are dispersed.

In addition, as a production method thereof, (a) an aqueous solution of a water-soluble metal salt is added to a predetermined colloidal aqueous solution of active silicic acid or acidic silica sol as a metal oxide with respect to SiO _{2 of the} colloidal aqueous solution or acidic silica sol. A step of preparing a mixed solution 1 by adding an amount of mass%, (b) an acidic spherical silica sol having an average particle diameter of 10 to 80 nm and a pH of 2 to 6 to the mixed solution 1, and a silica content derived from the acidic spherical silica sol The ratio A / B (weight ratio) of (A) and the silica content (B) derived from the mixed liquid 1 is 5 to 100, and the mixed liquid 2 obtained by mixing the acidic spherical silica sol and the mixed liquid 1 All silica content (a + B) a step of adding and mixing amount corresponding to SiO ₂ concentration of 5 to 40 mass% in the liquid mixture 2, and an alkali metal hydroxide to the mixture 2 obtained (c), a water-soluble organic of It describes a method for producing the silica sol comprising a step of adding an organic base or a water-soluble silicate so that the pH is 7 to 11, mixing, and heating.

JP-A-2001-11433 (Patent Document 9) discloses a water-soluble II in an aqueous colloidal solution of active silicic acid containing 0.5 to 10% by mass as SiO ₂ and having a pH of 2 to 6. an aqueous solution containing valence or III valent metal salt singly or as a mixture thereof, with respect to SiO ₂ colloid solution having the same active silicic acid in the case of the metal oxide (II valent metal salt and MO, the III In the case of a metal salt of M ₂ O ₃ , M represents a II or III valent metal atom, and O represents an oxygen atom.) Then, an acidic spherical silica sol having an average particle size of 10 to 120 nm and a pH of 2 to 6 is added to the obtained mixed liquid (1), and the silica content (A) derived from the acidic spherical silica sol and the mixed liquid (1). The ratio A / B (weight ratio) of silica content (B) is 5 to 100, and this acid Spherical silica sol and the mixture (1) and the resulting mixture by mixing (2) the total silica content (A + B) is added and mixed so that SiO ₂ concentration of 5 to 40 mass% in the mixed solution (2) A bead of alkali metal hydroxide added to the mixture (2) and mixed so that the pH is 7 to 11, and the resulting mixture (3) is heated at 100 to 200 ° C. for 0.5 to 50 hours. A process for producing a silica sol is described.

  Japanese Patent Laid-Open No. 2001-48520 (Patent Document 10) describes a composition having a silica concentration of 1 to 8 mol / liter, an acid concentration of 0.0018 to 0.18 mol / liter, and a water concentration of 2 to 30 mol / liter. The alkyl silicate is hydrolyzed with an acid catalyst without using a solvent, diluted with water so that the silica concentration is in the range of 0.2 to 1.5 mol / liter, and then the pH is 7 or more. An alkali catalyst is added and heated to advance the polymerization of silicic acid, and the average diameter in the thickness direction by electron microscope observation is 5 to 100 nm, and the length is 1.5 to 50 times that of a long and thin shape. A method for producing a silica sol in which crystalline silica particles are dispersed in a liquid dispersion is described.

JP 2001-150334 A (Patent Document 11) discloses an acidic aqueous solution of activated silicic acid having a SiO ₂ concentration of about _{2 to} 6% by mass obtained by subjecting an aqueous solution of alkali metal silicate such as water glass to decation treatment. In addition, an alkaline earth metal such as a salt of Ca, Mg, Ba or the like is added in a weight ratio of 100 to 1500 ppm with respect to SiO ₂ of the above active silicic acid in terms of its oxide, and further SiO ₂ / M _{2 in} this solution. O (M represents an alkali metal atom, NH ₄ or a quaternary ammonium group.) The liquid obtained by adding the same alkaline substance in an amount that the molar ratio is 20 to 150 is initially used as the heel liquid. SiO ₂ / M ₂ O of SiO ₂ concentration of from 2 to 6% by weight obtained with 20 to 150 Te (M is the same. above) the active silicic acid aqueous solution having a molar ratio as charged liquid, 60 to 150 ° C. The charge liquid the initially heel solution, per hour, the charge liquid SiO ₂ / initially at a rate of 0.05 to 1.0 as a weight ratio of the heel solution SiO _2, while evaporating and removing water from the liquid (or allowed No.), a method for producing a silica sol having a distorted shape is described.

  In JP-A-2003-133267 (Patent Document 12), the average particle diameter is in the range of 5 to 300 nm as polishing particles capable of suppressing dishing (overpolishing) and polishing the substrate surface flatly. Abrasive particles comprising a group of irregularly shaped particles in which two or more primary particles are bonded, and in particular, the primary particles constituting the irregularly shaped particle group in the total number of primary particles in the abrasive particles There is a description that polishing particles having a particle number of 5 to 100% are effective.

  JP 2004-288732 A (Patent Document 13) discloses a slurry for semiconductor polishing characterized by containing non-spherical colloidal silica, an oxidizing agent and an organic acid, and the balance being water. Among them, non-spherical colloidal silica (major axis / minor axis) having a major axis / minor axis of 1.2 to 5.0 has been proposed, and a similar non-true one is also disclosed in Japanese Patent Application Laid-Open No. 2004-311652 (Patent Document 14). Spherical colloidal silica is disclosed.

  Japanese Patent Laid-Open No. 10-128121 (Patent Document 15) describes a method for producing a silica sol by adding an alkali silicate aqueous solution to a core particle dispersion or an alkali silicate aqueous solution in the presence of an electrolyte to grow the core particles. Alternatively, a silica-based composite oxide sol is produced by growing a core particle by adding an alkali silicate aqueous solution and an aqueous metal salt or non-metal salt solution other than silicon to a nuclear particle dispersion or an alkali silicate aqueous solution in the presence of an electrolyte. A method for producing a silica sol or a composite silica sol is disclosed, and this production method is capable of obtaining a silica sol and a silica-based composite oxide sol that are excellent in production efficiency, have a high particle growth rate, and have a uniform and uniform particle size. It is stated that there is.

The applicant of the present patent application disclosed in Japanese Patent Application Laid-Open No. 2003-26417 (Patent Document 16) as a method for producing a silica sol having excellent production efficiency, high particle growth rate, uniform particle size, and stable liquid I (nuclear particle dispersion). liquid or aqueous solution of an alkali silicate), the presence of an electrolyte comprising a salt of a strong acid, is added II solution (alkali silicate aqueous solution) in growing core particles, the number of equivalents of alkali II solution and (E _{a) A} method for producing a silica sol was proposed in which the ratio (E _A / E _E ) of the number of equivalents of electrolyte (E _E ) is in the range of 0.5-8.
According to the production method, a stable silica sol having a uniform particle size can be obtained, but when used as a polishing composition, there is a limit in polishing performance.

As an example having a protruding structure on the surface of silica-based fine particles, JP-A-3-257010 (Patent Document 17) discloses a continuous surface having a size of 0.2 to 5 μm as observed with an electron microscope on the surface of silica particles. There is a description relating to silica particles having irregular projections, an average particle diameter of 5 to 100 μm, a BET specific surface area of 20 m ² / g or less, and a pore volume of 0.1 mL / g or less.

  Japanese Patent Application Laid-Open No. 2002-38049 (Patent Document 18) discloses silica-based fine particles having substantially spherical and / or hemispherical protrusions on the entire surface of the base particle, and the protrusion is chemically bonded to the base. Silica-based fine particles having substantially spherical and / or hemispherical protrusions on the entire surface of the silica-based fine particles and the base particles, characterized in that they are bound to the particles, wherein the protrusions are chemically bonded to the base particles. And (A) a step of hydrolyzing and condensing a specific alkoxysilane compound to produce polyorganosiloxane particles, and (B) the surface of the polyorganosiloxane particles by a surface adsorbent. And (C) forming protrusions on the entire surface of the polyorganosiloxane particles surface-treated in the step (B) using the alkoxysilane compound. Step of, is described a method for manufacturing the silica-based particles comprising a.

Japanese Patent Laid-Open No. 2004-35293 (Patent Document 19) discloses silica-based particles having substantially spherical and / or hemispherical protrusions on the entire surface of the base particles, and the protrusions are bonded to the base by chemical bonding. Silica-based particles are disclosed that are bound to particles and have different compressive elastic moduli at 10% compression between the base particles and the protrusions.
However, the silica particles described in JP-A-3-257010 (Patent Document 17) have an average particle diameter of 5 to 100 μm and are disclosed in JP-A-2002-38049 (Patent Document 18). The average particle diameter of the particles is substantially only 0.5 to 30 μm, and the same applies to JP-A-2004-35293 (Patent Document 19).

  In addition, in Japanese Patent Application Laid-Open No. 2001-352966 (Patent Document 20), the present patent applicant relates to a technique for promoting aggregation or sedimentation of a substance present in a liquid by adding silica sol to a predetermined liquid. Disclosed is a fermented liquid food dripping agent characterized in that the fine particle zeta potential in the pH 4 to 6 range of the sol is negative and the absolute value is 35 mV or more. It was reported that the turbidity of soy sauce was lowered from 58 to 20 in 3 hours after the addition of the sol.

JP-A-1-317115 Japanese Patent Laid-Open No. 4-65314 Japanese Patent Laid-Open No. 4-187512 Japanese Patent No. 3441142 Japanese Patent Laid-Open No. 7-118008 JP-A-8-279480 JP-A-11-214338 International Publication WO00 / 15552 JP 2001-11433 A JP 2001-48520 A JP 2001-150334 A JP 2003-133267 A JP 2004-288732 A JP 2004-311652 A JP-A-10-128121 JP 2003-26417 A JP-A-3-257010 JP 2002-38049 A JP 2004-35293 A JP 2001-352966 A

An object of the present invention is to provide a confetti-like inorganic oxide sol in which fine spherical inorganic oxide fine particles having a unique shape of confetti are dispersed in a solvent, and to provide a production method thereof.
Moreover, this invention makes it a subject to provide the polishing composition containing the said gold-peeled sugar-like inorganic oxide sol. In particular, among the polishing characteristics, the polishing rate is maintained at least at the same level as the conventional one, and the generation of scratches (linear traces) generated on the surface of the substrate to be polished is significantly suppressed compared to the conventional one. Another object of the present invention is to provide a polishing composition that is excellent in surface accuracy of a substrate to be polished.

The present invention
(A) the sphericity is in the range of 0.8 to 1,
(B) Surface roughness (SA1) when the specific surface area measured by the sodium titration method is (SA1) and the specific surface area converted from the average particle diameter (D2) measured by the image analysis method is (SA2) / (SA2) is in the range of 1.20 to 1.70,
(C) The average particle diameter (D2) measured by the image analysis method is in the range of 10 to 60 nm.
The above-mentioned problem is solved by a confetti-like inorganic oxide sol in which confetti-like inorganic oxide fine particles having ridge-like projections on the surface of spherical inorganic oxide fine particles are dispersed in a solvent.

  It is preferable that the gold flat sugar-like inorganic oxide fine particles are composed of silica, silica-alumina, silica-zirconia, silica-ceria, silica-titania or a composite thereof.

According to the method for producing the gold flat sugar-like inorganic oxide sol of the present invention, after adding an acidic silicic acid solution to the core particle dispersion to grow the core particles, the addition rate is 1.2 to 1.8 times the addition rate. An acidic silicic acid solution is added again to grow the core particles to prepare a confetti-like inorganic oxide sol.
The core particle dispersion is preferably an alkali silicate aqueous solution and / or a mixture of an alkali aqueous solution and an acidic silicate liquid, and silica fine particles can be produced by addition of the acidic silicate liquid.

The core particle dispersion is preferably a dispersion of silica fine particles, alumina fine particles, zirconia fine particles, ceria fine particles, or composite fine particles thereof.
It is preferable that the pH of the core particle dispersion is adjusted to 8-12.
An acidic silicic acid solution of 50 to 10,000 parts by mass (silica conversion) is added to the core particle dispersion at a rate of 0.020 to 80 parts by mass / min (silica conversion) with respect to 100 parts by mass of the solid content in the dispersion. Then, it is preferable to add 50 to 10,000 parts by mass (silica conversion) of acidic silicic acid solution at an addition rate of 0.024 to 144 parts by mass / min (silica conversion).

  The polishing composition of the present invention is characterized in that it contains the above-mentioned confetti-like inorganic oxide sol.

  The confetti-like inorganic oxide sol of the present invention is a sol in which spherical particles having unique ridge-like projections are dispersed. This confetti inorganic oxide sol can be used, for example, as an abrasive that is a component of the polishing composition. According to the polishing composition containing the konpeira-like inorganic oxide sol, the polishing rate is the same level as the conventional one, but the generation of scratches on the substrate to be polished due to polishing is suppressed compared to the conventional one. The surface accuracy of the substrate to be polished after polishing can also be improved.

In addition, the gold flat sugar-like inorganic oxide fine particles exhibit different filling properties, oil absorption, electrical properties, optical properties, or physical properties from ordinary spherical silica fine particles because of their unique structure.
According to the production method of the present invention, it is possible to easily prepare a sol in which confetti-like spherical particles are dispersed.

[Kinpeira sugar-like inorganic oxide sol]
In the confetti-like inorganic oxide sol of the present invention, the dispersoid of the confetti-like inorganic oxide fine particles has a unique ridge-like projection on the spherical particle surface. Since the shape thereof is generally similar to that of confetti, in the present invention, such a structure is referred to as “competitive sugar”. The confetti-like inorganic oxide sol of the present invention is a sol containing such confetti-like fine particles (average particle diameter of 10 to 60 nm) and exhibits, for example, an excellent effect as an abrasive.

About the surface of the gold flat sugar-like inorganic oxide fine particle which has the said hook-shaped protrusion, the range is prescribed | regulated by surface roughness.
In the present invention, the surface roughness is converted from the average particle diameter (D2) measured by the image analysis method, assuming that the value of the specific surface area (surface area per unit mass) measured by the sodium titration method is (SA1). When the value of the specific surface area is (SA2), the surface roughness is defined as (SA1) / (SA2).

  Here, the specific surface area (SA1) measured by the sodium titration method (Sears method) is to obtain the specific surface area of the silica fine particles from the consumption amount of the sodium hydroxide solution when the sodium hydroxide solution is titrated against the silica sol. It can be said that it reflects the actual surface area. Specifically, the value of the specific surface area (SA1) increases as the surface of the fine particles is richer in undulations or ridges. In place of the sodium titration method, a specific surface area measured by a nitrogen adsorption method (BET method) may be used.

Further, with respect to the specific surface area (SA2) converted from the average particle diameter (D2) measured by the image analysis method, a photographic projection view obtained by taking a photograph of a sample gold-peeled inorganic oxide sol with a transmission electron microscope. Assuming that the average particle diameter (D2) is the average value when the maximum diameter (DL) of any 50 particles is measured, the silica fine particles dispersed in the sample silica sol are ideal spherical particles. Thus, the specific surface area (SA2) is calculated from the following equation (1).
SA2 = 6000 / (D2 × ρ) (1)

However, in Formula (1), (rho) is the density of a sample particle and is 2.2 in the case of silica. In the case of composite fine particles such as silica-alumina composite fine particles, silica-zirconia composite fine particles, silica-ceria composite fine particles, or silica-titania composite fine particles, the density of each oxide (alumina 3.3 to 4.0, zirconia 5. 49, ceria 7.3, titania 4.6), and the weight ratio of each oxide in each sample particle.
Since this relational expression is based on the above assumption, it can be said that the value of the specific surface area (SA2) corresponds to the specific surface area when the particles are spherical.
Since the specific surface area indicates the surface area per unit mass, the value of the surface roughness (SA1) / (SA2) is such that the more the particles are spherical and the surface of the particles has more ridge-like projections ( The value of (SA1) / (SA2) increases, the smaller the number of wrinkles on the particle surface and the smoother, the smaller the value of (SA1) / (SA2), and the value approaches 1.

  In the present invention, the surface roughness of the gold flat sugar-like inorganic oxide fine particles is in the range of 1.20 to 1.70. When the surface roughness is less than 1.20, the ratio of the ridge-like protrusions is small, or the ridge-like protrusions themselves are smaller than the particle diameter of the silica fine particles, and the closer the surface roughness is to 1.00, the more spherical particles are formed. It will be close. In addition, in order to obtain the effect of the present invention, if the surface roughness is in the above range, a sufficient effect can be obtained. A range of 1.25 to 1.68 is recommended as the surface roughness range.

  The gold-plated sugar-like inorganic oxide fine particles need to be spherical, and do not include irregular-shaped particles such as rod-shaped, slanted-ball-shaped, elongated, beaded, or egg-shaped. In the present invention, the term “spherical” means that the sphericity is in the range of 0.8 to 1.0. Here, the sphericity is the maximum diameter (DL) and the short diameter (DS) orthogonal to each of any 50 particles in a photographic projection obtained by photographing with a transmission electron microscope. Mean ratio (DS / DL). When the sphericity is less than 0.8, the inorganic oxide fine particles may not be spherical but may correspond to the irregular shaped particles.

The average value of the average particle diameter (D2) measured by the image analysis method is in the range of 10 to 60 nm for the gold flat sugar-like inorganic oxide fine particles according to the present invention. In the case of less than 10 nm, it is not easy to prepare silica fine particles having a necessary surface roughness. Moreover, sufficient effects can be obtained if the average particle diameter is in the above range to obtain the effects of the present invention. The average particle size (D2) of the confetti inorganic oxide fine particles is preferably in the range of 12 to 40 nm.
The solvent in which the gold flat sugar-like inorganic oxide fine particles of the present invention are dispersed may be water, an organic solvent, or a mixed solvent thereof.

  The gold-peeled sugar-like inorganic oxide sol of the present invention satisfying the above requirements concerning the surface roughness, the sphericity and the average particle diameter is a very unique one in which the gold-peeled sugar-like fine particles having hook-shaped protrusions are dispersed in a solvent. . For this reason, for example, when the confetti-like inorganic oxide sol of the present invention is used as an abrasive, the wrinkled projections on the surface of the particles uniformly act on the surface of the substrate to be polished. In addition to being able to polish with excellent surface accuracy, it is possible to suppress the occurrence of scratches.

  With regard to the gold flat sugar-like inorganic oxide sol of the present invention, in the method for producing the gold flat sugar-like inorganic oxide sol described later, the inorganic oxides of the gold flat sugar-like inorganic oxide sol are silica, silica-alumina, silica- It may be selected from zirconia, silica-ceria, silica-titania or a composite thereof. Specifically, it is selected from gold-peeled silica sol, gold-peeled silica-alumina composite sol, gold-peeled silica-zirconia composite sol, gold-peeled silica-ceria composite sol, gold-peeled silica-titania composite sol or alumina, zirconia, ceria or titania. An olivine sugar-like inorganic oxide sol containing two or more kinds and silica. Of these, from the standpoint of raw material costs and the like, gold flat sugar silica sol or gold flat sugar silica-alumina composite sol is particularly preferable.

[Production Method of Konpei Sugar-like Inorganic Oxide Sol]
In the particle growth step of gradually adding the silicic acid solution to the core particle dispersion, by increasing the addition rate of the silicic acid solution during the particle growth step, A confectionary inorganic oxide sol is prepared. This manufacturing method will be described below.

Core particle dispersion The core particle dispersion used in the method for producing the gold flat sugar-like inorganic oxide sol of the present invention is an indispensable raw material in the method for producing the gold flat sugar-like inorganic oxide sol of the present invention. It means a dispersion in which a particle serving as a nucleus for particle growth is dispersed in a solvent by adding an acidic silicic acid solution.
The core particle is not particularly limited as long as it can be a nucleus of particle growth. Preferable examples include silica fine particles, alumina fine particles, zirconia fine particles, ceria fine particles, zirconia fine particles, and composite fine particles thereof. The core particle dispersion is preferably adjusted to pH 8 to 12, preferably pH 9.5 to 11.5 by adding alkali silicate before addition of the acidic silicic acid solution. When alkali silicate is added, the concentration of SiO ₂ dissolved in the dispersion medium is preliminarily increased when the acidic silicate solution for particle growth is added next, so that precipitation of silicic acid on the core particles is likely to occur quickly. Become.

As an alkali silicate used here, it is preferable to use the solution which melt | dissolved the silica in organic bases, such as alkali silicate other than sodium silicate (sodium water glass), such as potassium silicate (potassium water glass), or a quaternary amine. Moreover, alkali metal hydroxides other than NaOH, ammonium, and quaternary ammonium hydride can be added as needed. Furthermore, alkali metal hydroxides such as Mg (OH) ₂ , Ca (OH) ₂ , Sr (OH) ₂ and Ba (OH) ₂ can be preferably used.
Further, as the core particle dispersion liquid, an alkali silicate aqueous solution and / or a mixture of an alkali aqueous solution and an acidic silicate liquid which can generate silica fine particles by addition of the acidic silicate liquid may be used. In this case, if the silica fine particles are dispersed, it can be used as a core particle dispersion, but at the stage where an acidic silicic acid solution for particle growth is added, silica fine particles are generated by increasing the silica concentration. There may be. Regarding the alkali silicate aqueous solution and / or the mixture of the alkali aqueous solution and the acidic silicic acid solution, the molar ratio of SiO ₂ / M ₂ O (M is an alkali metal) is 10 to 70, and the silica concentration is 0.5 to 7% by mass. Is desirable.

About the kind of alkali silicate used here, the thing similar to the said alkali silicate can be used. An aqueous ammonia solution or the like is used as the alkaline aqueous solution. Moreover, about pH, the range of pH 8-12 is suitably desirable like the above.
The particle size of the core particles is selected mainly by the particle size of the sol to be finally obtained. In the present application, the upper limit of the average particle size of the product of the confetti-like inorganic oxide sol as a product is determined. Since it is defined as 60 nm, it is preferably less than 60 nm, and more preferably 50 nm or less. The lower limit of the particle diameter is not particularly limited as long as it functions as a core particle, but is preferably larger than a silicic acid oligomer, particularly a 10-mer or more.

As for the shape of the core particle, since the target product shape is a gold flat sugar-like inorganic oxide fine particle having hook-shaped protrusions on the surface of the spherical inorganic oxide fine particle, it is preferably a spherical fine particle. In the case of a bead-like particle formed by connecting remarkably chain-shaped fine particles or particles, it may be difficult to form spherical fine particles even by particle growth, which is not desirable.
The concentration of the core particle dispersion varies depending on the particle diameter of the core particles, but is preferably in the range of 0.005 to 10% by mass, more preferably 0.01 to 5% by mass as an oxide. When the concentration of the core particle dispersion is less than 0.005% by mass, the amount of the core particles is too small, and the productivity is significantly reduced. If the concentration of the core particle dispersion exceeds 10% by mass, the concentration may be too high and the core particles may aggregate due to the addition of alkali.

The aging core particle dispersion is aged as necessary after pH adjustment. The aging temperature is 40 to 150 ° C., preferably 60 to 100 ° C., and the aging time is about 30 minutes to 5 hours, although it varies depending on the aging temperature. By performing such aging, the properties of the core particle dispersion are stabilized.

Acid silicate solution and particle growth The acid silicate solution used in the method for producing the gold flat sugar-like inorganic oxide sol of the present invention is prepared by dealkalizing a water-soluble silicate, usually an aqueous solution of silicate. Is an aqueous solution of a low polymer of silicic acid obtained by dealkalization by a method such as treating with a cation exchange resin. This type of silicic acid solution usually has a pH of 2 to 4, SiO ₂ / Na ₂ O (molar ratio) of 100 to 5,000, and a SiO ₂ concentration of 10% by mass or less, preferably 2 to 7% by mass. Gelation at normal temperature hardly occurs, is relatively stable, and is practically used as a raw material.

  In the production method of the confetti-like inorganic oxide sol of the present invention, an acidic silicic acid solution is continuously or intermittently added to the core particle dispersion (hereinafter referred to as “pre-term addition”), and then the pre-phase. The acidic silicic acid solution is added continuously or intermittently at an addition rate of 1.2 to 1.8 times the acidic silicic acid solution addition rate at the time of addition (hereinafter referred to as “late addition”). It is said. By increasing the addition rate of the acidic silicate solution to the core particle dispersion during the particle growth, the added acidic silicate solution remains in an oligomeric or acidic silicate solution without depositing on the particle surface in the form of a monomer. Since it adheres to the particle surface, it is considered that ridge-like protrusions are easily formed on the particle surface.

  In the production method of the present invention, the acidic silicic acid solution is to be added continuously or intermittently to the core particle dispersion. Here, the addition rate refers to the period of early addition and the period of late addition. Mean average addition rate of each. Specific embodiments relating to the addition of the acidic silicic acid solution include 1) when the acidic silicic acid solution is dropped, and 2) when the acidic silicic acid solution is continuously supplied without interruption.

In the period of the first addition, it is required that spherical inorganic oxide fine particles are generated by normal particle growth. For this reason, normal conditions are applied to the conditions for grain growth during the period of the previous addition.
Specifically, with respect to 100 parts by mass of silica contained in the core particle dispersion, an acidic silicic acid solution corresponding to 50 to 5000 parts by mass of silica is added at a temperature of 20 ° C. or less and an addition rate of 0.020 to 80 Add at parts per minute. When the amount of the silicic acid solution to be added (in terms of silica) exceeds 5000 parts by mass, the average particle size may exceed the average particle size of the gold flat sugar-like inorganic oxide sol to be obtained in the present invention. It may become impossible to perform the two-stage addition of the liquid. When the amount is less than 50 parts by mass, there may be a case where particles having a size sufficient to serve as a nucleus for generating hook-shaped protrusions cannot be obtained by late addition.
The temperature at the time of addition is recommended to be 20 ° C. or lower, preferably in the range of 1 to 18 ° C. for maintaining the temporal stability of the acidic silicic acid solution.

When the addition rate is less than 0.020 parts by mass / min, the productivity is remarkably lowered and it becomes difficult to generate hook-shaped protrusions. When the addition rate exceeds 80 parts by mass / min, the aggregation of particles or new Nucleation tends to occur.
The time required for the addition in the first period is not limited as long as the addition is performed within the addition rate range and the addition amount range for the first period addition of the acidic silicic acid solution.
Immediately after the end of the period of the first period addition, the period of the second period addition starts immediately after the addition rate of the acidic silicic acid solution is increased.

Specifically, with respect to 100 parts by mass of silica contained in the core particle dispersion, an acidic silicic acid solution corresponding to 50 to 5000 parts by mass of silica is added at a temperature of 20 ° C. or less and an addition rate of 0.024 to 144. Add at parts per minute. In addition, about the addition speed | rate of the acidic silicic acid liquid in late addition, it is necessary to increase to 1.2 to 1.8 times the addition speed of the first period addition. By increasing the speed in this range, it is easy to produce a confetti-like silica sol having ridge-like projections on the surface for the reasons described above.
When the rate of increase of the acidic silicic acid solution during the latter period of addition is less than 1.2 times the rate of addition of the acidic silicic acid solution during the previous period of addition, the monomer is used because the acidic silicic acid solution is sufficiently dissolved. Precipitation is likely to occur, and hook-like projections are difficult to be generated. When the speed increasing ratio exceeds 1.8 times, the inorganic oxide fine particles are easily aggregated due to the rapid addition of the acidic silicic acid solution, and the tendency for new nucleation to occur does not contribute to the particle growth.

In the latter addition, the amount of silica solution used (silica conversion) is 100 parts by weight of silica contained in the core particle dispersion (excluding silica derived from the acidic silicate solution added by the previous addition). And the range of 50-5000 mass parts is desirable. The temperature at the time of addition is recommended to be 20 ° C. or lower, preferably in the range of 1 to 18 ° C. for maintaining the temporal stability of the acidic silicic acid solution.
In particular, when the addition rate exceeds 144 parts by mass / min, aggregation of inorganic oxide fine particles and new nucleation easily occur. Note that the time required for the late addition also depends on the amount of the finally obtained confetti inorganic oxide sol, and is not limited.
The time required for the late addition is not limited as long as it is added in the above-described addition rate range and the addition amount range regarding the later addition of the acidic silicic acid solution.

After adding the total amount of the aging acidic silicic acid solution, this is aged as necessary. The aging temperature is 40 to 150 ° C., preferably 60 to 100 ° C., and the aging time is about 30 minutes to 5 hours, although it varies depending on the aging temperature. By performing such aging, generally a silica sol having a more uniform particle diameter and excellent stability can be obtained.

The obtained konpeito-like inorganic oxide sol is concentrated as necessary. As the concentration method, an ultrafiltration membrane method, a distillation method or a combination thereof is usually employed. The concentration of the confetti inorganic oxide sol after concentration is approximately 10 to 50% by mass in terms of oxide. Range.

[Abrasive and polishing composition]
The gold flat sugar-like inorganic oxide sol of the present invention is useful as an abrasive and a polishing composition. Specifically, the confetti-like inorganic oxide sol of the present invention can be applied as an abrasive by itself, and further constitutes a normal polishing composition together with other components (such as a polishing accelerator). It is also possible to do.

  The polishing composition according to the present invention is obtained by dispersing the above-described confetti silica-based fine particles in a solvent. As the solvent, water is usually used, but alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol can be used as necessary, and water-soluble organic solvents such as ethers, esters, and ketones are also used. be able to. The concentration of the abrasive silica particles in the abrasive is preferably in the range of 2 to 50% by weight, more preferably 5 to 30% by weight. When the concentration is less than 2% by weight, the concentration may be too low depending on the type of the base material or the insulating film, and the polishing rate may be slow and productivity may be a problem. If the concentration of silica particles exceeds 50% by weight, the stability of the abrasive will be insufficient, the polishing rate and the polishing efficiency will not be further improved, and the dried product will be removed in the step of supplying the dispersion for polishing treatment. It may be generated and attached, which may cause scratches.

  The polishing composition according to the present invention varies depending on the type of the material to be polished, but it may be used by adding a conventionally known hydrogen peroxide, peracetic acid, urea peroxide, or a mixture thereof as necessary. it can. When such hydrogen peroxide or the like is added and used, when the material to be polished is a metal, the polishing rate can be effectively improved. If necessary, an acid such as sulfuric acid, nitric acid, phosphoric acid or hydrofluoric acid, or a sodium salt, potassium salt, ammonium salt or a mixture thereof can be added. In this case, when a plurality of kinds of materials to be polished are polished, a flat polishing surface can be finally obtained by increasing or decreasing the polishing rate of the material to be polished having a specific component.

  As other additives, for example, imidazole, benzotriazole, benzothiazole and the like can be used in order to form a passive layer or a dissolution suppressing layer on the surface of the metal polishing material to prevent erosion of the substrate. In order to disturb the passive layer, a complex forming material such as an organic acid such as citric acid, lactic acid, acetic acid, oxalic acid, phthalic acid, citric acid, or an organic acid salt thereof may be used. In order to improve the dispersibility and stability of the abrasive slurry, a cationic, anionic, nonionic or amphoteric surfactant can be appropriately selected and added. Furthermore, the pH of the abrasive slurry can be adjusted by adding an acid or a base as necessary in order to enhance the effect of each additive.

[Analysis methods used in Examples and Comparative Examples]
Preferred embodiments of the present invention will be described below. [1] A specific surface area (SA2) calculation method calculated from an average particle diameter (D2) measured by an image analysis method, and [2] sodium titration method. Unless otherwise specified, the specific surface area (SA1) measurement, [3] specific surface area measurement by nitrogen adsorption method, [4] sphericity measurement method, and [5] polishing property evaluation method for aluminum substrate are measured. Measured or calculated in accordance with analytical methods [1] to [5] described later, and the results are shown in Table 2.

[1] Measurement method of average particle diameter (D2) by image analysis and calculation method of specific surface area (SA2) Photograph of sample silica sol at a magnification of 250,000 times with a transmission electron microscope (H-800, manufactured by Hitachi, Ltd.) The maximum diameter (DL) of any 50 particles in a photograph projection view obtained by photographing was measured, and the average value was defined as the average particle diameter (D2). Further, the specific surface area (SA2) was determined by substituting the value of the average particle diameter (D2) into the formula (1).

[2] Measurement of specific surface area (SA1) and average particle diameter (D1) by sodium titration method (Sears method) 1) A sample corresponding to 1.5 g as SiO ₂ was collected in a beaker and then incubated at 25 ° C. Transfer to a tank and add pure water to make the volume 90 ml. The following operation was performed in a constant temperature reaction tank maintained at 25 ° C.
2) Add 0.1 mol / L hydrochloric acid aqueous solution so that pH becomes 3.6.
3) Add 30 g of sodium chloride, dilute to 150 ml with pure water and stir for 10 minutes.
4) A pH electrode is set, and 0.1 mol / L aqueous sodium hydroxide solution is added dropwise with stirring to adjust the pH to 4.0.
5) The sample adjusted to pH 4.0 was titrated with a 0.1 mol / L sodium hydroxide aqueous solution, and the titration amount and pH value in the range of pH 8.7 to 9.3 were recorded at 4 points or more. A calibration curve is prepared, where X is the titration amount of 1 mol / L sodium hydroxide aqueous solution and Y is the pH value at that time.

6) Consumption V (ml) of 0.1 mol / L sodium hydroxide aqueous solution required for pH 4.0 to 9.0 per 1.5 g of SiO _{2 was obtained} from the following formula (3), and the following formula (4) ) To calculate the specific surface area.
Moreover, average particle diameter D1 (nm) is calculated | required from Formula (5).
V = (A × f × 100 × 1.5) / (W × C) (3)
SA1 = 29.0V−28 (4)
D1 = 6000 / (ρ × SA1) (5) (ρ: density of sample)
However, the meanings of the symbols in the above formula (3) are as follows.
A: Titration amount of 0.1 mol / L sodium hydroxide solution required for pH 4.0 to 9.0 per 1.5 g of SiO ₂ (ml)
f: Potency of 0.1 mol / L sodium hydroxide solution C: SiO ₂ concentration of sample (%)
W: Sampling amount (g)

[3] Specific surface area measurement by nitrogen adsorption method (BET method) 50 ml of silica sol was adjusted to pH 3.5 with HNO ₃ , 40 ml of 1-propanol was added, and the sample was dried at 110 ° C. for 16 hours. A sample for measurement was obtained by firing in an oven at 500 ° C. for 1 hour. And the specific surface area was computed by the BET 1 point method from the adsorption amount of nitrogen using the nitrogen adsorption method (BET method) using the specific surface area measuring apparatus (The product made from Yuasa Ionics, model number multisorb 12).
Specifically, 0.5 g of a sample is taken in a measurement cell, degassed for 20 minutes at 300 ° C. in a mixed gas stream of nitrogen 30 v% / helium 70 v%, and then the sample is liquidized in the mixed gas stream. Keep nitrogen temperature and allow nitrogen to equilibrate to sample. Next, the sample temperature was gradually raised to room temperature while flowing the mixed gas, the amount of nitrogen desorbed during that time was detected, and the specific surface area of the silica sol was calculated using a calibration curve prepared in advance. The average particle diameter D1 (nm) is obtained from the above formula (5).

[4] Method for measuring sphericity Any 50 of the photographic projections obtained by photographing a sample silica sol at a magnification of 250,000 times with a transmission electron microscope (H-800, manufactured by Hitachi, Ltd.) About each particle | grain, ratio (DS / DL) of the largest diameter (DL) and the short diameter (DS) orthogonal to this was measured, and those average values were made into sphericity.

[5] Evaluation method of polishing characteristics for aluminum substrate
Preparation of Slurry for Slurry To the gold flat sugar-like silica sol having a silica concentration of 20% by mass obtained in each Example and each Comparative Example, H ₂ O ₂ , HEDP (1-hydroxyethylidene-1,1-disulfonic acid) and ultrapure water were added. In addition, a polishing slurry of 9% by mass of silica, 0.5% by mass of H ₂ O _{2 and} 0.5% by mass of HEDP was prepared, and further, HNO ₃ was added as necessary to prepare a polishing slurry of pH 2. .

Polishing Substrate An aluminum disk substrate was used as the polishing substrate. This aluminum disk substrate is a substrate (95 mmΦ / 25 mmΦ-1.27 mmt) obtained by electrolessly plating Ni-P to a thickness of 10 μm (a hard Ni-P plating layer having a composition of Ni88% and P12%) on an aluminum substrate. It was used. This substrate was first polished and the surface roughness (Ra) was 0.17 nm.

Polishing test The above substrate to be polished is set in a polishing apparatus (manufactured by Nano Factor Co., Ltd .: NF300), and a polishing pad (“Apollon” manufactured by Rodel) is used and polished at a substrate load of 0.05 MPa and a table rotation speed of 30 rpm. Polishing was performed by supplying the slurry for 5 minutes at a rate of 20 g / min. The polishing rate was calculated by determining the weight change of the substrate to be polished before and after polishing. Specifically, the amount of polishing per unit time is obtained by dividing the weight difference (g) between the substrate before and after polishing by the specific gravity (8.4 g / cm ³ ), and further dividing by the substrate surface area (65.97 cm ² ) and polishing time. (Nm / min) was calculated.

Scratch generation Regarding the generation of scratches, after polishing the substrate for an aluminum disk in the same manner as described above, the entire surface was measured with Zoom 15 using an ultra-fine defect / visualization macro device (product name: Micro-MAX, manufactured by VISION PSYTEC). The number of scratches (linear traces) on the polished substrate surface corresponding to 65.97 cm ² was counted and totaled.

Surface accuracy Here, the surface accuracy means the surface roughness of the surface to be polished. For measurement of surface accuracy, an atomic force microscope (manufactured by Digital Instruments: AFM, NanoScope IIIa) was used. The surface roughness of the polishing substrate was measured at a scan rate of 1.0 Hz and a scan area of 2.0 × 2.0 μm, and the value was determined as the surface roughness Ra (nm).

Synthesis example 1

(Preparation of silicic acid solution)
7,000 g of 7% sodium silicate (No. 3 water glass) was passed through an ultra module (SIP-1013 manufactured by Asahi Kasei Co., Ltd.) and the filtrate was collected to obtain purified water glass. Pure water was added so that the silica concentration of the purified water glass was 5%. Then, 6,650 g of water glass having a silica concentration of 5% was passed through 2.2 L of strongly acidic cation exchange resin SK1BH (manufactured by Mitsubishi Chemical Corporation) at a space velocity of 3.1 to obtain 6,650 g of a silicic acid solution. . The silica concentration of the obtained silicic acid solution was 4.7%.

(Preparation of confetti silica sol)
Pure water 833.5 g was added to 67.2 g of sodium silicate (No. 3 water glass, SiO ₂ concentration 24.28 mass%) to prepare 906.7 g of an aqueous sodium silicate solution having a silica concentration of 1.8 mass%. To this sodium silicate aqueous solution, 264.1 g of the silicic acid solution obtained in Synthesis Example 1 was added and stirred, and then the temperature was raised to 79 ° C. and held at 79 ° C. for 30 minutes to obtain a core particle dispersion. Hereinafter, 28.7 g of the silica content in the core particle dispersion is converted to 100 parts by mass, and the part by mass of the added amount of the silicic acid solution is displayed.

Next, 6122.2 g of the silicic acid solution obtained in Synthesis Example 1 cooled to 18 ° C. was continuously added over 9 hours at an addition rate of 11.3 g / min (1.8 parts by mass / min in terms of silica). Added. Subsequently, 2040.6 g of the silicic acid solution obtained in Synthesis Example 1 cooled to 18 ° C. was continuously added over 2 hours at an addition rate of 17.0 g / min (2.8 parts by mass in terms of silica). Added. After completion of the addition, the mixture was kept at 79 ° C. for 1 hour and then cooled to room temperature.
The obtained silica sol was concentrated using an ultrafiltration membrane (product name: SIP-1013, manufactured by Asahi Kasei Corporation) until the silica concentration became 12% by mass. Subsequently, it concentrated to 20% density | concentration with the rotary evaporator.

The resulting silica sol had an average measured by the image analysis method particle diameter (D2) is 15 nm, converted from D2 the specific surface area of 181.8m ² / g, specific surface area measured by sodium titration 248m ² / g, sphericity It was confirmed that the gold flat sugar-like silica sol was obtained by dispersing gold flat sugar-like silica fine particles having a degree of 0.88 and a surface roughness of 1.36 in water.
[Polishing test]
[5] An evaluation test was performed by the method for evaluating polishing characteristics of the aluminum substrate. The same applies to the following examples and comparative examples.

(Preparation of confetti silica sol)
673.1 g of pure water was added to 41.2 g of sodium silicate (No. 3 water glass, SiO ₂ concentration: 24.28 mass%) to prepare 714.3 g of an aqueous sodium silicate solution having a silica concentration of 1.4 mass%. To this sodium silicate aqueous solution, 37.2 g of the silicic acid solution obtained in Synthesis Example 1 was added and stirred, and then the temperature was raised to 83 ° C. and kept at 83 ° C. for 30 minutes to obtain a core particle dispersion. Hereinafter, 11.7 g of the silica content in the core particle dispersion is converted to 100 parts by mass, and the part by mass of the added amount of the silicic acid solution is displayed.

Next, 4470.5 g (1788 parts by mass in terms of silica) of the silicic acid solution obtained in Synthesis Example 1 cooled to 18 ° C. was added at a rate of 9.2 g / min (3.7 parts by mass in terms of silica). , And added continuously over 8.1 hours. Subsequently, 1915.9 g (766 parts by mass in terms of silica) of the silicic acid solution obtained in Synthesis Example 1 cooled to 18 ° C. was added at a rate of 11.0 g / min (4.4 parts by mass / in terms of silica). Added continuously over 2.9 hours. After completion of the addition, the mixture was kept at 83 ° C. for 1 hour and then cooled to room temperature.
The obtained silica sol was concentrated using an ultrafiltration membrane (product name: SIP-1013, manufactured by Asahi Kasei Corporation) until the silica concentration became 12% by mass. Subsequently, it concentrated to 20 mass% with the rotary evaporator.

The resulting silica sol had an average measured by the image analysis method particle diameter (D2) is 23 nm, converted from D2 the specific surface area of 118.6m ² / g, specific surface area measured by sodium titration 152m ² / g, sphericity It was confirmed that the gold flat sugar-like silica sol was obtained by dispersing gold flat sugar-like silica fine particles having a degree of 0.95 and a surface roughness of 1.28 in water.

(Preparation of confetti silica sol)
705.9 g of pure water was added to 46.5 g of sodium silicate (No. 3 water glass, SiO ₂ concentration 24.28% by mass) to prepare 752.4 g of a sodium silicate aqueous solution having a silica concentration of 1.5% by mass. To this sodium silicate aqueous solution, 12.9 g of the silicic acid solution obtained in Synthesis Example 1 was added and stirred, and then the temperature was raised to 83 ° C. and maintained at 83 ° C. for 30 minutes to obtain a core particle dispersion.

Next, 917.3 g of the silicic acid solution obtained in Synthesis Example 1 cooled to 18 ° C. (363 parts by mass in terms of silica) was added at an addition rate of 5.1 g / min (2.0 parts by mass in terms of silica). Added continuously over time. Subsequently, 5497.2 g of silica solution obtained in Synthesis Example 1 cooled to 18 ° C. (2173 parts by mass in terms of silica) was added at a rate of 7.6 g / min (3.0 parts by mass in terms of silica), Added continuously over 12 hours. After completion of the addition, the mixture was kept at 83 ° C. for 1 hour and then cooled to room temperature.
The obtained silica sol was concentrated using an ultrafiltration membrane (product name: SIP-1013, manufactured by Asahi Kasei Corporation) until the silica concentration became 12% by mass. Subsequently, it concentrated to 20% density | concentration with the rotary evaporator.

The obtained silica sol has an average particle diameter (D2) measured by image analysis method of 36 nm, a specific surface area of 75.8 m ² / g converted from D2, a specific surface area of 96 m ² / g by sodium titration method, and a true sphere It was confirmed that the gold flat sugar silica sol was obtained by dispersing gold flat sugar silica fine particles having a degree of 0.9 and a surface roughness of 1.27 in water.

Comparative Example 1

A silica sol having an average particle diameter of 83 nm converted from a specific surface area measured by a nitrogen adsorption method with a silica concentration of 40.6% by mass was diluted with pure water to give a silica concentration of 20% by mass. The silica sol had an average particle diameter (D2) of 115 nm measured by an image analysis method, a specific surface area of 23.7 m ² / g converted from D2, a specific surface area of 33 m ² / g by a nitrogen adsorption method, and a sphericity of 0 It was confirmed that it was a gold flat sugar-like silica sol having a surface roughness of 1.39.

Comparative Example 2

A sodium silicate aqueous solution (SiO ₂ / Na ₂ O molar ratio: 3.1) having a SiO ₂ concentration of 24% by mass is diluted with ion-exchanged water to obtain a sodium silicate aqueous solution (pH 11.3) having a SiO ₂ concentration of 5% by mass. 1 kg was prepared.
Sulfuric acid was added to neutralize this sodium silicate aqueous solution so that the pH was 6.5, and the mixture was kept at room temperature for 1 hour to prepare a silica hydrogel. This silica hydrogel was sufficiently washed with an oliver filter with pure water (an amount equivalent to about 120 times the SiO ₂ solid content) to remove salts. The sodium sulfate concentration after washing was less than 0.01% based on the SiO ₂ solid content.
The obtained silica hydrogel was dispersed in pure water (silica concentration 3% by mass) to obtain a silica hydrogel dispersion in a fluid slurry state with a powerful stirrer, and an aqueous NaOH solution having a concentration of 5% by mass was added to SiO ₂ / Na ₂ O molar ratio is added to a 75, it was heated at 160 ° C..

Next, 0.81 kg of a 24% sodium silicate aqueous solution and 10.93 kg of pure water were added to 2.09 kg of the silica sol to prepare 13.83 kg (pH 11.2) of a seed sol. The average particle size of the seed sol measured by the dynamic light scattering method was 17 nm.
Next, while maintaining the seed sol at 83 ° C., 175.8 kg of a silicic acid solution having a SiO ₂ concentration of 3% by mass described later was added over 14 hours.

After completion of the addition, the mixture was cooled to room temperature, and the obtained silica sol was concentrated to an SiO ₂ concentration of 20% by mass with an ultrafiltration membrane.
The average particle diameter measured by the image analysis method of this silica sol was 35 nm, and the specific surface area was 78 m ² / g.

Synthesis example 2

(Preparation of silicic acid solution)
0.8 kg of sodium silicate (No. 3 water glass) having a silica concentration of 24% was passed through an ultra module (SIP1013 manufactured by Asahi Kasei Co., Ltd.), and filtrate was collected to obtain purified water glass. Pure water was added to the resulting purified water glass to adjust the silica concentration to 3.2%. By passing 6,500 g of this diluted water glass through 2.2 L of strongly acidic cation exchange resin SK1BH (manufactured by Mitsubishi Chemical Corporation) at a rate of 3 L / hour, 6,650 g of acidic silicic acid solution was obtained. The silica concentration of the obtained silicic acid solution was 3.0%.

Comparative Example 3

To the silicic acid solution having a silica concentration of 4.7% obtained in the same manner as the silicic acid solution prepared in Synthesis Example 2, pure water is added to adjust the silica concentration to 2%, and the mixture is stirred for 10 minutes. Ammonia water having a concentration of 1% was added so as to be 4.8, and the mixture was aged by keeping it at room temperature for 2 hours to obtain 6650 g of a polymerized silicic acid solution.
To 1,000 g of this polymerized silicic acid solution, 15% ammonia water was added so that the pH was 10.4, the temperature was raised to 95 ° C., and the mixture was heated for 1 hour, cooled to room temperature, A clear pale sol was obtained. The obtained sol had an average particle size of 31 nm as measured by a dynamic light scattering method and a solid content concentration of 1.9%.

To 284.7 g of the sol obtained by heating, 20.81 g of No. 3 water glass having a silica concentration of 24.25% was added, the pH was adjusted to 11.2, and the temperature was raised to 83 ° C. and maintained for 30 minutes. Then, 4,333 g of the silicic acid solution (silica concentration: 3.0% by mass) obtained in Synthesis Example 2 was added over 18 hours. After completion of the addition, the mixture was further maintained at 83 ° C. for 1 hour and then cooled to room temperature.
Then, ultraconcentration and concentration with a rotary evaporator were performed in the same manner as in Example 1 to obtain a 30% concentration silica sol.
The average particle diameter measured by the image analysis method of this silica sol was 23 nm, and the specific surface area was 119 m ² / g.

Comparative Example 4

626.5 g of silica sol having a silica concentration of 30% by mass obtained in Comparative Example 3 was diluted with 3239 g of ultrapure water, and 20.8 g of No. 3 water glass having a silica concentration of 24.25% by mass was further added. The temperature was adjusted to 7 and the temperature was raised to 87 ° C. and kept for 30 minutes. Then, 4,333 g of the silicic acid solution (silica concentration: 3.0% by mass) prepared in Synthesis Example 2 was added over 2 hours. After completion of the addition, the mixture was further maintained at 87 ° C. for 1 hour and then cooled to room temperature.
Subsequently, ultraconcentration and concentration by a rotary evaporator were performed in the same manner as in Example 1 to obtain a silica sol having a silica concentration of 30% by mass.
The average particle diameter measured by the image analysis method of this silica sol was 32 nm, and the specific surface area was 85 m ² / g.

Comparative Example 5

In Example 3, the acid silicic acid solution was not added in two stages consisting of the first and second additions, and 6414.5 g of the acid silicic acid solution was 7.2 g / min (without changing the addition rate while maintaining the temperature of 35 ° C). A silica sol was prepared in the same manner as in Example 3 except that the addition was performed over 15 hours at 2.8 parts by mass in terms of silica) to prepare a silica sol (silica concentration 20% by mass).
The obtained silica sol has an average particle diameter (D2) measured by an image analysis method of 27 nm, a specific surface area of 101 m ² / g converted from D2, a specific surface area by a sodium titration method of 135 m ² / g, and a sphericity of 0 It was confirmed that this was a silica sol in which silica fine particles having a surface roughness of 1.34 and a surface roughness of 1.34 were dispersed in water.

  The gold-peeled silica sol of the present invention has high utility as an abrasive. Further, since it has excellent filling properties, oil absorption properties, electrical properties, optical properties, or physical properties, it is applied to paint additives, resin additives, ink receiving layer components, cosmetic components, and the like.

Claims (8)

(A) the sphericity is in the range of 0.8 to 1,
(B) Surface roughness (SA1) when the specific surface area measured by the sodium titration method is (SA1) and the specific surface area converted from the average particle diameter (D2) measured by the image analysis method is (SA2) / (SA2) is in the range of 1.20 to 1.70,
(C) The average particle diameter (D2) measured by the image analysis method is in the range of 10 to 60 nm.
A confetti-like inorganic oxide sol obtained by dispersing, in a solvent, confetti-like inorganic oxide fine particles having hook-shaped protrusions on the surface of spherical inorganic oxide fine particles.   2. The confetti composition according to claim 1, wherein the confetti inorganic oxide fine particles are composed of silica, silica-alumina, silica-zirconia, silica-ceria, silica-titania, or a composite thereof. Inorganic oxide sol.   After adding the acidic silicate solution to the core particle dispersion to grow the core particles, the acidic silicate solution is added again at an addition rate of 1.2 to 1.8 times the addition rate to grow the core particles. A method for producing a confetti-like inorganic oxide sol comprising preparing a confetti-like inorganic oxide sol.   4. The core particle dispersion is an alkali silicate aqueous solution and / or a mixture of an alkali aqueous solution and an acidic silicate liquid, and silica fine particles can be formed by adding the acidic silicate liquid. A method for producing a confetti-like inorganic oxide sol.   4. The method for producing a gold flat sugar-like inorganic oxide sol according to claim 3, wherein the core particle dispersion is a dispersion of silica fine particles, alumina fine particles, zirconia fine particles, ceria fine particles or composite fine particles thereof.   6. The method for producing a gold flat sugar-like inorganic oxide sol according to any one of claims 3 to 5, wherein the pH of the core particle dispersion is adjusted to 8 to 12.   An acidic silicic acid solution of 50 to 10,000 parts by mass (silica conversion) is added to the core particle dispersion at a rate of 0.020 to 80 parts by mass / min (silica conversion) with respect to 100 parts by mass of the solid content in the dispersion. 4. An oxytocinous inorganic oxide according to claim 3, wherein 50 to 10,000 parts by mass (silica conversion) of an acidic silicic acid solution is added at an addition rate of 0.024 to 144 parts by mass / min (silica conversion). A method for producing a sol.   A polishing composition comprising the gold-peeled inorganic oxide sol according to claim 1 or 2.