JP2009155180A - Particle-linked alumina-silica composite sol and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an alumina-silica composite sol and a method for manufacturing the sol having excellent characteristics such as polishing property and comprising particle-linked alumina-silica composite fine particles dispersed in a dispersion medium. <P>SOLUTION: The particle-linked alumina-silica composite sol comprises the particle-linked alumina-silica composite fine particles dispersed in the dispersion medium, which includes linked structures of two or more alumina-silica composite primary particles having an average particle diameter of 5 to 300 nm measured by an image analysis method, wherein the particle-linked alumina-silica composite fine particles contain spherical particles having a plurality of bump-like projections on the surface as the alumina-silica composite primary particles. A method for manufacturing the sol is also disclosed. Since the particle-linked alumina-silica composite fine particles of the present invention have a specific structure different from normal particle-linked silica fine particles or aspheric alumina-silica composite particles, the obtained particles have excellent packing property, oil absorptivity, electric characteristics, optical characteristics and physical characteristics. An aspheric alumina-silica composite sol relating to the present invention is useful as a polishing material and a polishing composition, and particularly excellent in an effect for high polishing speed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

Particle-linked type in which particle-linked alumina-silica composite fine particles formed by bonding two or more spherical primary particles having an average particle diameter in the range of 5 to 300 nm measured by an image analysis method are dispersed in a dispersion medium Alumina-silica composite sol, wherein the particle-coupled alumina-silica composite fine particles have a plurality of hook-shaped protrusions on the surface thereof.
The present invention relates to a silica composite sol and a method for producing the same. The particle-linked alumina
The present invention relates to a polishing composition containing a silica composite sol.

  Of the particle-coupled silica sols in which the particle-coupled silica sol is dispersed in a solvent, the chain-coupled silica sols having a shape other than a spherical shape are known to be chain-like, beaded, or oval. Yes. Such particle-linked silica sols are used as various abrasives, for example.

As a method for producing a particle-coupled silica sol containing irregularly shaped particles, JP-A-1-317115 (Patent Document 1) describes a measurement particle size (D ₁ ) by an image analysis method and a measurement particle size (D ₁ ) by a nitrogen gas adsorption method. ₂ ) The ratio D ₁ / D ₂ is 5 or more, D ₁ is 40 to 500 millimicrons, and stretched only in one plane with a uniform thickness in the range of 5 to 40 millimicrons by electron microscope observation As a method for producing a particle-coupled silica sol in which elongated colloidal silica particles having a solid shape are dispersed in a liquid medium, (a) a water-soluble calcium salt or magnesium salt is added to a predetermined colloidal aqueous solution of active silica (B) Further, an alkali metal oxide, a water-soluble organic base or a water-soluble silicate thereof is added to SiO ₂ / M ₂ O (where M is the alkali Metal atom or existence Represents a base molecule)) a step of adding and mixing so that the molar ratio is 20 to 200; and (c) a method of heating the mixture obtained in the previous step at 60 to 150 ° C. for 0.5 to 40 hours. Is disclosed.

Japanese Patent Laid-Open No. 4-65314 (Patent Document 2) describes a ratio D ₁ / D ₂ between a particle diameter measured by an image analysis method (D ₁ millimicron) and a particle diameter measured by a nitrogen gas adsorption method (D ₂ millimicron). Is less than 3 and less than 5, and this D ₁ is 40 to 500 millimicrons and 5 by electron microscopy.
A SiO ₂ concentration of 50 wt% formed by dispersing amorphous colloidal silica particles with a uniform thickness within the range of less than 100 mm but less than 100 mm and having an extension in only one plane in a liquid medium. %, The addition of an aqueous solution of active silicic acid to the elongated particle-coupled silica sol starts without collapsing the colloidal silica particles of the raw sol, and the original elongated shape. It is disclosed that elongated colloidal silica having an increased thickness can be obtained by depositing added active silicic acid on the surface of each particle through a siloxane bond.

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 an alkali metal or quaternary ammonium), and is set to 30 to 60, and then Ca, Mg, Al, In, Ti, Z
Add a compound of one or more metals selected from the group consisting of r, Sn, Si, Sb, Fe, Cu and rare earth metals (addition time may be before or during addition of the silicic acid solution) This mixed solution is maintained at an arbitrary temperature of 60 ° C. or higher for a certain period of time, and a silicic acid solution is further added to make the SiO ₂ / M ₂ O (molar ratio) in the reaction solution substantially 60 to 100 A method for producing a sol in which shaped particle-linked silica sol is dispersed is disclosed.

In Japanese Patent No. 3441142 (Patent Document 4), the 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 50% of all particles. A semiconductor wafer polishing agent made of a stable sol of silica occupying the above 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 process for producing an elongated particle-coupled silica sol comprising concentrating to a concentration of 6-30% by weight 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 weight SiO _2, preferably has a concentration of 0.5 to 30 wt%. 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 nitrogen adsorption method / D ₂ ) is 3 or more, and this D ₁ is 50 to 500 nm. A particle-linked silica sol is described in which beaded colloidal silica particles in which silica particles are connected only in one plane are dispersed.

Further, 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 an acidic particle-linked silica sol, and a metal with respect to SiO _{2 of the} colloidal aqueous solution or acidic particle-linked silica sol Mixture 1 by adding 1 to 10% by weight of oxide
(B) The acidic spherical particle coupled silica sol having an average particle size of 10 to 80 nm and pH 2 to 6 is added to the mixed solution 1 and the silica content (A) derived from the acidic spherical particle coupled silica sol and this The ratio A / B (weight ratio) of the silica content (B) derived from the mixed solution 1 is 5 to 100, and the total amount of the mixed solution 2 obtained by mixing the acidic spherical particle-linked silica sol and the mixed solution 1 A step of adding and mixing the silica content (A + B) in the mixed solution 2 so that the SiO ₂ concentration is 5 to 40% by weight; and (c) an alkali metal hydroxide, a water-soluble organic base or It describes a method for producing the particle-coupled silica sol comprising a step of adding a water-soluble silicate so that the pH is 7 to 11, mixing and heating.

JP-A-2001-11433 (Patent Document 9) describes a water-soluble II in an aqueous colloidal solution of active silicic acid containing 0.5 to 10% by weight 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, to the obtained mixed liquid (1), an acidic spherical particle-coupled silica sol having an average particle size of 10 to 120 nm and pH 2 to 6, the silica content (A) derived from this acidic spherical particle-coupled silica sol and this mixed liquid. The ratio A / B (weight ratio) of the silica content (B) derived from (1) is 5 to 5. 00, and, SiO ₂ concentration of 5 to 40 wt in total silica content (A + B) is a mixture (2) of the acidic spherical particles linked sol this mixture (1) and the resulting mixture by mixing (2) % To be mixed and mixed (2)
A bead-like particle-linked type in which an alkali metal hydroxide or the like is added 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 method for producing 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 particle-coupled 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 weight obtained by decation treatment of an aqueous solution of an alkali metal silicate such as water glass. In addition, an alkaline earth metal, for example, 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. 2 to 6% by weight of SiO ₂ concentration and 20 to 1
50 SiO ₂ / M ₂ O (M is the same as above) An active silicic acid aqueous solution having a molar ratio is used as a charge liquid, and the charge liquid is charged to the initial heel liquid at 60 to 150 ° C. per hour. Particle connected type having a distorted shape formed by adding while removing (or without) water from the liquid at a rate of 0.05 to 1.0 as a weight ratio of SiO ₂ / initial heel liquid SiO ₂ A method for producing silica sol 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.

In addition, regarding a silica-alumina-coated chain-particle-linked silica sol, JP-A No. 2002-3212 (Patent Document 15) discloses (a) 0.05 to 5.0% by weight as SiO _2.
A step of adding a silicic acid solution to the alkali metal silicate aqueous solution to make the mixed solution SiO ₂ / M ₂ O (molar ratio, M is an alkali metal or quaternary ammonium) 30 to 60, (b) A step of adding one or two or more metal compounds of divalent to tetravalent metals before, during or after the silicic acid solution adding step, (c) A step of maintaining at an arbitrary temperature of 0 ° C. or higher for a certain period of time, (d) a step of adding a silicic acid solution to the reaction solution again to make SiO ₂ / M ₂ O (molar ratio) in the reaction solution 60 to 200 (E) Further, a method for producing a silica-alumina-coated chain-particle-coupled silica sol comprising the step of simultaneously adding an alkali silicate aqueous solution and an alkali aluminate aqueous solution to the reaction solution on the alkali side is disclosed. .

As an example having a protruding structure on the surface of silica-based fine particles, JP-A-3-257010 (Patent Document 16) discloses a continuous surface having a size of 0.2 to 5 μm as observed on the surface of the silica particles with an electron microscope. 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 17) 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. There is a description of silica-based fine particles bound to. Furthermore, (A) a step of hydrolyzing and condensing a specific alkoxysilane compound to produce polyorganosiloxane particles, (B) a step of treating the polyorganosiloxane particles with a surface adsorbent, and (C) the above There is a description of a method for producing silica-based fine particles, including a step of forming protrusions on the entire surface of the polyorganosiloxane particles surface-treated in the step (B) using the alkoxysilane compound.

  Japanese Patent Application Laid-Open No. 2004-35293 (Patent Document 18) discloses silica-based 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 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 particles described in JP-A-3-257010 (Patent Document 16) are composed only of silica having an average particle diameter of 5 to 100 μm, and are disclosed in JP-A-2002-38049 (Patent Document 17). As for the silica-based particles, only an average particle diameter of 0.5 to 30 μm is disclosed, and the same applies to JP-A-2004-35293 (Patent Document 18).
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 2002-3212 A JP-A-3-257010 JP 2002-38049 A JP 2004-35293 A

  An object of the present invention is to provide an alumina-silica composite sol having particle-connected alumina-silica composite fine particles dispersed in a dispersion medium, and a method for producing the same. Another object of the present invention is to provide a polishing composition containing the non-spherical alumina-silica composite sol.

To achieve the above object, the present invention is as follows.
[1] Particle-linked alumina-silica composite fine particles containing a structure in which two or more alumina-silica composite primary particles having an average particle size measured by an image analysis method in the range of 5 to 300 nm are dispersed are dispersed in a dispersion medium. The particle-coupled alumina-silica composite sol, wherein the particle-coupled alumina-silica composite fine particles include spherical particles having a plurality of hook-shaped protrusions on the surface as primary particles of the alumina-silica composite. A particle-coupled alumina-silica composite sol.
[2] The particle-linked alumina-silica composite sol according to [1], wherein a variation coefficient of a radius of the alumina-silica composite primary particles is in a range of 3 to 30%.
[3] An abrasive comprising the particle-linked alumina-silica composite sol according to [1] or [2].
[4] A polishing composition comprising the particle-linked alumina-silica composite sol according to [1] or [2].
[5] Particle connection in which particle-linked silica fine particles formed by bonding two or more spherical silica primary particles having an average particle diameter in the range of 5 to 300 nm measured by an image analysis method are dispersed in a dispersion medium. Alumina-coated particles are obtained by continuously or intermittently adding 0.1 to 2.5 parts by mass of sodium aluminate to 100 parts by mass of the particle-linked silica fine particles, and then aging. Prepare a dispersion of linked silica fine particles, and then add alkali metal silicate corresponding to 0.1 to 100 parts by mass to 100 parts by mass of the alumina-coated particle-linked silica fine particles, and after aging, Further, the particle-linked alumina-silica according to any one of [1] and [2], wherein the silicic acid solution is added continuously or intermittently to grow particles and form protrusions. Production method of composite sol [6] The amount of the silicic acid liquid used is in the range of 3 to 700 parts by mass in terms of silica with respect to 100 parts by mass of the alumina-coated particle-coupled silica fine particles, and the addition of silicic acid liquid is 2 The method for producing a particle-linked alumina-silica composite sol according to [5], wherein the method is performed continuously or intermittently over 24 hours.

Since the particle-coupled alumina-silica composite fine particles of the present invention have a unique structure different from normal particle-coupled silica fine particles or non-spherical alumina-silica composite fine particles, filling properties, oil absorption properties, electrical properties, optical properties Or it has excellent physical properties. Therefore, the non-spherical alumina-silica composite sol according to the present invention is useful as, for example, an abrasive and a polishing composition, and is particularly excellent in the effect of a high polishing rate.

[Particle-linked alumina-silica composite sol]
The particle-coupled alumina-silica composite sol according to the present invention is a particle-coupled alumina-silica composite fine particle having a structure in which two or more alumina-silica composite primary particles having an average particle diameter in the range of 5 to 300 nm are combined. A particle-coupled alumina-silica composite sol dispersed in a dispersion medium, wherein the particle-coupled alumina-silica composite fine particle has a plurality of hook-shaped protrusions on the surface as an alumina-silica composite primary particle. It is characterized by including. Here, the alumina-silica composite fine particles and the alumina-silica composite primary particles refer to fine particles and primary particles composed of a portion made of alumina and a portion made of silica.

The particle-coupled alumina-silica composite fine particles, which are dispersoids of the particle-coupled alumina-silica composite sol, include, as primary particles, spherical particles having a plurality of hook-shaped protrusions on the surface, that is, so-called confetti-like spherical particles. This is structurally different from conventional particle-linked silica-based sols. The particle-coupled alumina-silica composite fine particles have various applications such as polishing applications, fillers for resin or film forming components, ink-receiving layers, etc. due to the presence of hook-like projections in addition to the particle-coupled structure. In applications such as fillers, it is possible to show unique effects. The hook-shaped protrusions can be confirmed by, for example, an electron micrograph of a non-spherical alumina-silica composite sol, and have a structure protruding from the peripheral portion or a swollen structure on the particle surface.

The particle-coupled alumina-silica composite fine particles, which are the dispersoid of the particle-coupled alumina-silica composite sol in the present invention, are a group of particles in a form in which primary particles are aggregated to be spheroidized or aggregated into a lump. Rather, it is a particle group in which two or more primary particles are bonded to form a chain, a fiber, or other irregular shapes. As the bonding mode of primary particles in this irregularly shaped particle group, two primary particles are bonded, three or more are bonded in a chain, three are bonded at three points, four are planar or In addition to those bonded in a tetrapot type, similarly those in which five or more particles are bonded, and the like, a deformed particle group in which these deformed particle groups are bonded together can be exemplified. The primary particles constituting the particle-coupled alumina-silica composite fine particles are bonded to each other in a range of 2 or more, preferably 2 to 20, particularly preferably 3 to 10. When the number of primary particles is one, for example, when applied as an abrasive, dishing is likely to occur.

  On the other hand, when more than 20 primary particles are bonded, the irregularly shaped particle group may be destroyed and scratches (linear marks) may be generated depending on the bonding form. In the case of a long chain shaped irregularly shaped particle group, the polishing rate may decrease. In addition, when the primary particles are aggregated in a lump shape, the thixotropy described later may not be exhibited, there is no difference from simply large spherical particles, and the effect of suppressing dishing cannot be sufficiently obtained. In this case as well, scratches may occur. The deformed particle group in which the primary particles are bonded in the range of 2 to 20 has a multi-point contact between the deformed particle group and the bottom surface of the concave surface of the polished surface having irregularities, and the deformed particle group has thixotropic properties. Therefore, the irregularly shaped particle group deposited in the concave portion during polishing is not easily moved from the concave portion, so that the bottom surface of the concave portion is not polished, so that dishing can be suppressed.

  The primary particles constituting the particle-coupled alumina-silica composite fine particles are preferably composed of spherical particles, but may contain oval, cubic or rod-like particles. Moreover, the particle diameters of the primary particles may be different from each other. Here, the spherical shape is not limited as long as it is not visually recognized as irregularly shaped particles such as a rod shape, a ball shape, an elongated shape, a bead shape, and an egg shape.

The average particle diameter of the primary particles is in the range of 5 to 300 nm, preferably 20 to 80 nm. More preferably, a range of 25 to 60 nm is recommended.
When the average particle diameter is less than 5 nm, the particle group obtained by aggregation of the primary particles tends to be agglomerated. In addition, in polishing applications, thixotropic properties are not exhibited, and it is difficult to obtain an effect of suppressing dishing, which is not preferable. When the average particle diameter exceeds 300 nm, for example, in polishing applications, the particles are excessive, and therefore the polishing rate may be reduced, or scratches (linear marks) may be generated on the polished surface.

  Regarding the particle-coupled alumina-silica composite fine particles, it is preferable that the variation coefficient (CV value) of the radius of the spherical particles constituting the particle-coupled silica fine particles is in the range of 3 to 30%. When it is less than 3%, the particle surface is almost smooth. When it exceeds 30%, preparation is not easy with the production method according to the present invention. About the variation coefficient (CV value) of a particle diameter, the range of 3.5-20% is recommended suitably. More preferably, the range of 4 to 15% is recommended.

  Regarding the coefficient of variation of the particle diameter in the present invention, the radius in the range of 0 to 30 ° C. from the central point of the particle toward the outer edge of the particle of the spherical particles constituting the particle-coupled alumina-silica composite fine particles Means the coefficient of variation.

  More specifically, each of the particles contained in the particle-coupled alumina-silica composite fine particles is an image of a scanning electron micrograph (250,000 to 500,000 times) of the particle-coupled alumina-silica composite sol. For a spherical particle, the longest line segment connecting two points on the outer edge of the spherical particle is drawn, and a point that bisects the line segment is defined as a center point O. From this center point O, a half line S passing through the end of the outer edge (intersection with the outer edge of the adjacent spherical particle, etc.) is drawn, and the center point O is the starting point at an interval of 5 degrees from the half line S. Draw 6 half straight lines. The length from each intersection of the seven straight lines including the half line S to the outer edge of the particle to the center point O is measured, and the coefficient of variation of the radius of the particle is calculated from the result. This operation is performed for all particles contained in one particle-coupled alumina-silica composite fine particle, and the maximum variation coefficient obtained is taken as the coefficient of variation of the radius of the particle-coupled alumina-silica composite fine particle. This operation is performed for 50 particle-coupled alumina-silica composite fine particles, and the average value of the obtained coefficient of variation in radius is used as the coefficient of variation in the radius of primary particles of the particle-coupled alumina-silica composite fine particles. An outline of how to obtain the coefficient of variation of the primary particle radius of the particle-coupled alumina-silica composite fine particles is shown in FIG. Here, the “outer edge of the particle” means a boundary line that appears on the scanning electron micrograph and forms a contour unique to the particle and the portion where the particle does not exist. That is, the boundary line of the part where the particle is bonded to another particle and the boundary line generated when the particle is bonded to the other particle are not included in the “outer edge of the particle”.

  When there are a plurality of the longest straight lines and there are a plurality of center points O, a straight line connecting the two center points (O1 and O2) at the most distant positions is used. The center point is determined again as a center point O. When a plurality of half lines passing through the end of the outer edge can be drawn from the center point O, the half line having the longest distance between the center point O and the outer edge is defined as a half line S.

  When the variation coefficient of the radius is in the above range, the particle-coupled alumina-silica composite fine particles have suitable hook-shaped protrusions and are particularly excellent in polishing characteristics. That is, in the particle-coupled alumina-silica composite fine particles of the present invention, it is not necessary that all of the primary particles constituting the particles are spherical particles having a plurality of hook-shaped protrusions on the surface, and the coefficient of variation is in the above range. If it exists, a favorable effect is brought about.

For the solvent in which the particle-linked alumina-silica composite sol is dispersed, water, an organic solvent,
Alternatively, any of these mixed solvents may be used. Examples thereof include alcohol-alumina-silica composites such as methyl alcohol, ethyl alcohol, and isopropyl alcohol, water-soluble organic solvents such as ethers, esters, and ketones.

[Method for producing particle-linked alumina-silica composite sol]
The method for producing the particle-linked alumina-silica composite sol of the present invention is a particle-linked method in which two or more spherical silica primary particles having an average particle diameter measured by an image analysis method in the range of 5 to 300 nm are bonded. 0.1-2.5 parts by mass of sodium aluminate is continuously or intermittently added to 100 parts by mass of the particle-coupled silica fine particles in a particle-coupled silica sol in which fine silica particles are dispersed in a dispersion medium. And then aging to prepare a dispersion of alumina-coated particle-linked silica fine particles. Next, it corresponds to 0.1 to 100 parts by mass with respect to 100 parts by mass of the alumina-coated particle-linked silica fine particles. After adding and aging the alkali metal silicate, the particles are further grown by continuous or intermittent addition of a silicic acid solution to form protrusions.

Raw Material Particle-Linked Silica Sol In the method for producing the particle-coupled alumina-silica composite sol of the present invention, the method for producing the particle-coupled silica sol used as the core particle of the raw material is not particularly limited, and known particles A linked silica sol can be applied. As such an example, a silica sol disclosed in JP-A-2003-133267 can be mentioned. For this, for example, a solution in which tetraethoxysilane is dissolved in a water / methanol mixed solvent is prepared, and this solution and an aqueous alkaline solution are simultaneously mixed in a water / methanol mixed solvent kept at 60 ° C. to 200 ° C. Add over time. After completion of the addition, aging is further performed at this temperature for 1 to 10 hours. Thereafter, unreacted tetraethoxysilane, methanol, and ammonia are almost completely removed with an ultrafiltration membrane, and pure water is added to prepare a silica concentration of 1% by mass, and then 1 in an autoclave at 250 to 350 ° C. A particle-linked silica sol having a structure in which two particles having an average particle diameter of 20 nm are linked in a chain by hydrothermal treatment for -20 hours, after hydrothermal treatment, and purification with both ion exchange resins and concentration. Can be obtained. Similarly, in JP-A-2003-133267, silica sol (average particle size 25 nm) was diluted to a SiO 2 concentration of 2% by mass, and then hydrothermally treated in an autoclave at 250 ° C. for 10 hours. It describes a method for producing a particle-coupled silica sol which is purified by an amphoteric ion exchange resin after hydrothermal treatment and then concentrated, and a particle-coupled silica sol obtained by this production method can also be used suitably. In addition to this, for example, silica sol obtained by the production method disclosed in JP-A-2007-153672 can be suitably used. Specifically, in a silica sol having a pH of 2 to 8 in which silica fine particles having an average particle diameter of 3 to 25 nm are dispersed, a polymetal salt with respect to 100 parts by weight of the silica solid content of the silica sol. The production method is characterized by adding 0.01 to 70 parts by weight of the compound and heating at 50 to 160 ° C.

  According to the method for producing a particle-coupled alumina-silica composite sol according to the present invention, since the particle-coupled alumina-silica composite fine particles having a structure similar to the structure of the raw material particle-coupled silica fine particles are likely to be produced, The structure of the particle-coupled silica fine particles is preferably a structure similar to or similar to the structure of the particle-coupled alumina-silica composite fine particles. Specifically, a group of particles in which two or more primary particles are combined to form a chain, a fiber, or other irregular shapes is included. As the bonding mode of primary particles in this irregularly shaped particle group, two primary particles are bonded, three or more are bonded in a chain, three are bonded at three points, four are planar or In addition to those bonded in a tetrapot type, similarly those in which five or more particles are bonded, and the like, a deformed particle group in which these deformed particle groups are bonded together can be exemplified. The particle-coupled silica fine particles have two or more spherical primary particles, that is, silica primary particles having an average particle diameter measured by an image analysis method in the range of 5 to 300 nm, preferably 2 to 20, particularly preferably. Are bonded to each other in the range of 3-10. The average particle diameter of the particle-linked silica fine particles is recommended to be in the range of 4 to 290 nm, preferably 20 to 80 nm.

Sodium aluminate In the production method of the present invention, an alumina-coated particle in which an aqueous solution of sodium aluminate (NaAlO ₂ ) is added to a raw material particle-coupled silica sol, and alumina is present in the form of spots on the particle-coupled silica sol surface A linked silica sol is prepared.

  Sodium aluminate (solid content concentration) is in the range of 0.1 to 2.5 parts by mass, preferably 0.1 to 2 parts per 100 parts by mass of the particle-coupled silica fine particles contained in the raw material particle-coupled silica sol. Used in the range of 0.0 part by mass. More preferably, the range of 0.1 to 1.9 parts by mass is recommended. When the amount of sodium aluminate used is within this range, the surface of the particle-coupled silica sol is not completely covered with alumina, and is almost covered with alumina in the form of spots. The surface of such an alumina-coated particle-coupled silica sol is presumed to form a chemical structure represented by the following formula (1).

Here, the vicinity of the Al atom is more water-soluble than the vicinity of the Si atom, so that it becomes a starting point for particle growth during the subsequent particle growth, and a plurality of protruding portions are formed on the surface of the particle-coupled silica sol. It is considered that the alumina-silica composite fine particles of the present invention are obtained through such a manufacturing process.

The temperature at which the sodium aluminate aqueous solution is added is desirably 10 to 30 ° C, and more preferably 10 to 28 ° C is recommended.
When it exceeds 30 ° C., nucleation of sodium aluminate occurs, and it is difficult to form a silica-alumina coating in the subsequent aging step. When the temperature is lower than 10 ° C., the reaction of sodium aluminate on the surface of the particle-coupled silica sol is poor, and therefore, a spot-like coating with alumina is difficult to form.

  Regarding the addition of the sodium aluminate aqueous solution, it is necessary to add continuously or intermittently over 10 minutes to 10 hours. When the sodium aluminate aqueous solution is continuously added, it is desirable to add the sodium aluminate aqueous solution in an equal or equivalent proportion within a predetermined addition time. Also, when sodium aluminate is intermittently added, it is desirable to add the sodium aluminate aqueous solution in an equal amount or in an equivalent amount within the addition time.

  When all of the required amount of sodium aluminate aqueous solution or most of the required amount is added at once, the surface of the particle-linked silica sol may be unevenly distributed, making it easy to form a spot-like coating. Therefore, it becomes difficult to obtain the target alumina-silica composite fine particles. Usually, when adding the sodium aluminate aqueous solution to the raw material particle-coupled silica sol, the raw material particle-coupled silica sol is sufficiently stirred.

After the sodium aluminate aqueous solution is added to the raw material particle-coupled silica sol, aging is required to form a heterogeneous layer of silica-alumina on the particle surface.
As aging conditions, it is necessary to carry out at 60 to 98 ° C. for 1 to 7 hours. If the aging temperature is less than 60 ° C., it takes time to make the surface a silica-alumina layer, which is not economical. Aging at temperatures above 98 ° C is not necessary. If the aging time is less than 1 hour, the formation of the silica-alumina layer is not sufficient, and the desired fine particles cannot be obtained. Aging over 7 hours is not necessary.

For the alumina-coated particle-coupled silica sol obtained in the particle growth process, after adding the alkali metal silicate and seeding before adding the silicic acid solution, the particles are grown by adding the silicic acid solution and further aged. Thus, an alumina-silica composite sol in which alumina-silica composite fine particles are dispersed in a solvent is prepared. This particle growth process will be described below.

Alkali Metal Silicate In the production method of the present invention, an alkali metal silicate is added to the alumina-coated particle-linked silica sol obtained in the previous step. When the alkali metal silicate is added, the concentration of SiO ₂ dissolved in the dispersion medium is set high in advance when the silicate solution for particle growth is added next. Precipitation of silicic acid on silica sol is accelerated.

  Examples of the alkali metal silicate include sodium silicate (water glass), potassium silicate, and lithium silicate. The tertiary ammonium silicate includes triethanolamine silicate, the quaternary ammonium silicate includes tetramethanol ammonium silicate, For example, tetraethanolammonium silicate is used. Usually, these alkali metal silicates are used in the form of an aqueous solution.

The addition of the alkali metal silicate to the alumina-coated particle-coupled silica sol is usually performed in the range of room temperature to 99 ° C., but is preferably performed at room temperature.
The amount of the alkali metal silicate added to the alumina-coated particle-coupled silica sol is preferably 0.1 to 100 parts by mass with respect to 100 parts by mass of the alumina-coated particle-coupled silica fine particles. When the addition amount of the alkali metal silicate is less than 0.1 parts by mass, no substantial influence is observed on the SiO ₂ concentration. When the amount exceeds 100 parts by mass, silica may be precipitated, which is not preferable.

About the addition amount of an alkali metal silicate, the range of 1-50 mass parts is recommended more suitably. More preferably, the range of 2 to 20 parts by mass is recommended.
After adding the alkali metal silicate, it is preferable to add the alkali metal silicate so that the silica solid content concentration is 1 to 10% by mass.

Aging
After adding the alkali metal silicate to the alumina-coated non-spherical silica sol, aging is performed by continuing stirring at 75 to 98 ° C. for about 10 minutes to 1 hour. Aging can increase the densification or homogenization of the particles.

Silicic acid solution The silicic acid solution used in the production method of the present invention is prepared by dealkalizing a water-soluble silicate, and usually a method of treating an aqueous silicate solution with a cation exchange resin. This is an aqueous solution of a low-polymerized silicic acid obtained by dealkalization at 1. This type of silicic acid solution usually has a pH of 2 to 4 and a SiO ₂ concentration of about 10% by mass or less, preferably 2 to 7% by mass.
Gelation at normal temperature hardly occurs, it is relatively stable, and is used as a practical raw material.

  The addition speed of such a silicic acid solution varies depending on the average particle diameter of the core particles and the concentration in the dispersion, but is preferably added within a range where fine particles other than the core particles are not generated. Further, the silicic acid solution can be added once or repeatedly until alumina-silica composite fine particles having a desired average particle diameter are obtained.

About the addition amount of a silicic acid liquid, the range of 5-300 mass parts is preferable with respect to 100 mass parts of alumina covering particle | grain connection type | formula silica fine particles. If it is less than 5 mass parts, it does not affect the production | generation of a hook-shaped processus | protrusion. When the amount exceeds 300 parts by mass, the silica component becomes excessive, and generation of hook-like protrusions may not be observed. About the addition amount of a silicic acid liquid, the range of 6-200 mass parts is recommended suitably. More preferably, the range of 7 to 150 parts by mass is recommended.

  Such a silicic acid solution is continuously or intermittently added at 70 to 99 ° C. over 2 to 24 hours. When the addition temperature is less than 70 ° C., excessive time may be required for particle growth, or particle growth itself may not proceed. If it exceeds 99 ° C., it boils, and thus particle growth may be inhibited. Regarding the addition time, it is not appropriate to add the whole amount at once, and particle growth is performed by adding continuously or intermittently over the time in the above range.

  After adding the silicic acid solution, it can be aged in the temperature range of 70 to 99 ° C. for 0.5 to 5 hours as necessary. When such aging is performed, the content of Na ions in the resulting alumina-silica composite fine particles may be further reduced, and the particle size distribution tends to be more uniform. Further, if necessary, excess ions can be removed using an ultrafiltration membrane or the like, and concentrated or diluted to a desired concentration to obtain a particle-linked alumina-silica composite sol. It is also possible to obtain a particle-linked alumina-silica composite sol in which an aqueous solvent is replaced with the above organic solvent by an ultrafiltration membrane method, a distillation method or the like.

[Abrasive and polishing composition]
The particle-linked alumina-silica composite sol of the present invention can be applied as an abrasive by itself, and can also constitute a normal polishing composition together with other components (such as a polishing accelerator). Is possible. The polishing composition according to the present invention is obtained by dispersing particle-linked alumina-silica composite 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. If the concentration is less than 2% by weight, the concentration may be too low depending on the type of substrate or insulating film, resulting in a slow polishing rate and productivity. 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]
Hereinafter, preferred examples of the present invention will be described. Measurement methods of various characteristics in the examples and comparative examples were carried out as described below unless otherwise specified. The results are shown in Tables 1-5.

[1] Measurement of average particle size of particle-coupled alumina-silica composite primary particles by image analysis method Using a scanning electron microscope (H-800, manufactured by Hitachi, Ltd.), the particle-coupled alumina-silica composite fine particles were scaled to 250,000. In a photographic projection obtained by taking a photograph at a magnification (or 500,000 times), the maximum value of the diameter is taken for two ends of one connected particle, and the average value of the primary particles in the connected particle is taken. The same measurement was performed for 50 linked particles, and the average particle size was defined as the average particle size of the particle-linked alumina-silica composite primary particles.

[2] Method for measuring radius variation coefficient of primary particles Included in particle-coupled alumina-silica composite fine particles in the image of scanning electron micrograph (250,000 to 500,000 times) of particle-coupled alumina-silica composite sol For each spherical particle, the longest line segment l is drawn out of the line segments connecting the two points on the outer edge, and the point that bisects the line segment l is set as the center point O. From this center point O, a half line S passing through the end P of the outer edge (intersection with the outer edge of an adjacent spherical particle, etc.) is drawn, and the center point O is the starting point at intervals of 5 degrees from the half line S. Draw 6 half-lines through. The length from each intersection of the seven straight lines including the half line S to the outer edge of the particle to the center point O is measured, and the coefficient of variation of the radius of the particle is calculated from the result. This operation is performed for all particles contained in one particle-coupled alumina-silica composite fine particle, and the maximum variation coefficient obtained is taken as the coefficient of variation of the radius of the particle-coupled alumina-silica composite fine particle. This operation is performed for 50 particle-coupled alumina-silica composite fine particles, and the average value of the obtained coefficient of variation in radius is used as the coefficient of variation in the radius of primary particles of the particle-coupled alumina-silica composite fine particles. An outline of how to obtain the coefficient of variation of the primary particle radius of the particle-coupled alumina-silica composite fine particles is shown in FIG. Here, the “outer edge of the particle” means a boundary line that appears on the scanning electron micrograph and forms a unique contour of the particle and a portion where the particle does not exist. That is, the boundary line of the part where the particle is bonded to another particle and the boundary line generated when the particle is bonded to the other particle are not included in the “outer edge of the particle”.

  When there are a plurality of the longest straight lines and there are a plurality of center points O, a straight line connecting the two center points (O1 and O2) at the most distant positions is used. The center point is determined again as a center point O. When a plurality of half lines passing through the end of the outer edge can be drawn from the center point O, the half line having the longest distance between the center point O and the outer edge is defined as a half line S.

[3] Specific surface area measurement and average particle diameter measurement by Sears method 1) A sample corresponding to 1.5 g as SiO ₂ was collected in a beaker, and then a constant temperature reaction vessel (2
5 ° C.) and add pure water to make the volume 90 ml. (The following operations were 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 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 0.1 mol / L sodium hydroxide solution, and the titer 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 titer of 1 mol / L sodium hydroxide solution and Y is the pH value at that time.
6) 0.1 required for pH 4.0 to 9.0 per 1.5 g of SiO ₂ from the following formula (2)
The consumption amount V (ml) of the mol / L sodium hydroxide solution is obtained, and the specific surface area SA [m ² / g] is obtained according to the following formula (3).

  Further, the average particle diameter D1 (nm) is obtained from the equation (4).

(Where ρ represents the particle density (g / cm ³ ). In the case of silica, 2.2 is substituted.
)
However, the meanings of the symbols in the above formula (2) 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)

[4] Specific surface area measurement and average particle diameter measurement by BET method (nitrogen adsorption method) 50 ml of particle-coupled silica sol was adjusted to pH 3.5 with HNO ₃ , and 1-propanol 4
A sample which was added with 0 ml and dried at 110 ° C. for 16 hours was pulverized in a mortar and then baked in a muffle furnace at 500 ° C. for 1 hour to obtain a measurement sample. 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 particle-coupled silica sol was calculated using a calibration curve prepared in advance. Further, the obtained specific surface area (SA) was substituted into the formula (4) to determine the average particle diameter D1.

[5] Measurement of solid content of alumina-coated particle-coupled silica sol 2 g of sample (alumina-coated particle-coupled silica sol dispersion) was evaporated to dryness with a crucible, and the resulting solid was fired at 1000 ° C. for 1 hour, and then desiccator Cool and weigh. The content of the alumina-coated particle-linked silica sol was determined from these weight differences.

[6] Evaluation Method of Polishing Characteristics for Aluminum Substrate Preparation of Polishing Slurry Particle-connected alumina-silica composite sol having a silica concentration of 20% by mass obtained in each Example and each Comparative Example was added to H ₂ O ₂ , HEDP (1 -Hydroxyethylidene-1,1-disulfonic acid) and ultrapure water were added, silica 9% by weight, H ₂ O ₂ 0.5% by weight, 1-hydroxyethylidene-1,1-disulfonic acid 0.5% by weight A polishing slurry having a pH of 2 was prepared by adding HNO ₃ as necessary.

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.

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.
[Synthesis Example 1]

Production of Particle-Linked Silica Sol (A) 2982.5 g of a solution obtained by dissolving 532.5 g of tetraethoxysilane (* 1) in 2450 g of a water / methanol mixed solvent (weight ratio of water and methanol = 2/8) was prepared, This solution and 596.4 g of an aqueous ammonia solution having a concentration of 0.25% by mass were simultaneously added to a water / methanol mixed solvent (mixed with 139.1 g of pure water and 169.9 g of methanol) kept at 60 ° C. for 20 hours. Added.

After completion of the addition, the mixture was further aged at this temperature for 3 hours. Thereafter, unreacted tetraethoxysilane, methanol and ammonia were removed almost completely with an ultrafiltration membrane, and pure water was added to prepare a silica concentration of 1% by weight. Next, hydrothermal treatment was performed in an autoclave at 300 ° C. for 10 hours. After hydrothermal treatment, it is purified with both ion exchange resins, concentrated, and has a solid content concentration of 20% by weight consisting of a structure in which 2 to 5 particles having an average particle diameter of 20 nm and 4 spherical particles are averagely connected in a chain form. A particle-linked silica sol (A) was obtained.
* 1: (Tama Chemical Co., Ltd .: ethyl silicate 28, SiO2 = 28% by weight)
[Synthesis Example 2]

Production of particle-linked silica sol (B) Particle-coupled alumina having a solid content concentration of 20% by weight in the same manner as in Synthesis Example 1 except that pure water was added to prepare a silica concentration of 0.5% by weight. A silica composite sol (B) was obtained. The obtained particle-coupled silica sol (B) had a structure in which 1 to 4 particles having an average particle diameter of 20 nm and 3 spherical particles on average were linked in a chain.
[Synthesis Example 3]

Production of particle-linked silica sol (C) Particle-coupled alumina having a solid content of 20% by weight in the same manner as in Synthesis Example 1 except that pure water was added to adjust the silica concentration to 2.5% by weight. A silica composite sol (C) was obtained. The obtained particle-coupled silica sol (C) had a structure in which 2 to 8 particles having an average particle diameter of 20 nm and 6 spherical particles on average were linked in a chain.
[Synthesis Example 4]

Production of particle-linked silica sol (D) Silica sol (manufactured by Catalytic Chemical Industry Co., Ltd .: Cataloid SI-50, average particle diameter 25 nm by image analysis method, SiO2 concentration 48% by weight) was diluted to SiO2 concentration 2% by weight. Hydrothermal treatment was performed in an autoclave at 250 ° C. for 10 hours. After hydrothermal treatment, it is purified with an amphoteric ion exchange resin, then concentrated, and a solid content concentration of 20% by weight having a structure in which 1 to 6 particles having an average particle diameter of 25 nm are connected in an average of 4 chains or tetrapots. % Particle-linked silica sol (D) was obtained.

Particle-linked silica sol prepared by the method of Synthesis Example 1 (primary average particle diameter 20 nm converted from specific surface area measured by image analysis method, average number of connected particles 4, specific surface area 139 m ² / g)
Pure water was added to adjust the silica concentration to 15.4% by weight.

850 g of 0.9 wt% aqueous solution of sodium aluminate [chemical formula: NaAlO ₂ ] was added to 6500 g of the particle-coupled silica sol at 12 ° C. .76 parts by mass) was added evenly over 4 hours with stirring. And it heated up to 90 degreeC and age | cure | ripened for 3 hours.

  The content of solid content (alumina-coated particle-coupled silica fine particles) of the obtained dispersion of alumina-coated particle-coupled silica fine particles was measured by the solid content measurement method of [4] and found to be 13.7% by weight. . Pure water was added to 1199 g of this alumina-coated particle-coupled silica sol to prepare a concentration of 2.9% by weight.

  27 g of No. 3 water glass (silica concentration 24 wt%) is added to 5586 g of this alumina-coated particle-coupled silica sol (equivalent to 4.0 parts by mass of silica with respect to 100 parts by mass of alumina-coated particle-coupled silica fine particles). The mixture was aged for 30 minutes after being heated to 98 ° C., and 4305 g of a silica solution having a silica concentration of 3% by weight (the silica content of the silica solution was 79.100 parts by mass with respect to 100 parts by mass of the alumina-coated particle-coupled silica fine particles after the completion of the aging. 7 parts by mass) was gradually added over 7 hours with stirring. After completion of the addition, the mixture was aged at 98 ° C. for 1 hour.

Thereafter, concentration is performed while supplying pure water so that the liquid level is always constant at the outer membrane (SIP-1013) until the electric conductivity of the aqueous solution becomes constant, and then the silica concentration becomes 12% by weight. Concentrated to 30% and then concentrated to 30% on a rotary evaporator. Table 5 shows the characteristics of the obtained particle-linked alumina-silica composite sol. Manufacturing conditions are described in Tables 1-4. Further, a scanning electron micrograph of this particle-linked alumina-silica composite sol (magnification: 2)
20000) is shown in FIG.

Particle-linked silica sol prepared by the method of Synthesis Example 2 (primary average particle diameter 20 nm converted from specific surface area measured by image analysis method, average number of connections 3, specific surface area 139 m ² / g)
Pure water was added to adjust the silica concentration to 15.4% by weight.

At 14 ° C., 482 g of a 0.9 wt% aqueous solution of sodium aluminate [Chemical Formula: NaAlO ₂ ] was added to 6500 g of this particle-coupled silica sol (0.1 parts of sodium aluminate with respect to 100 parts by mass of silica in the particle-coupled silica sol). 43 parts by mass) was added evenly over 2 hours with stirring. And it heated up to 90 degreeC and age | cure | ripened for 3 hours.

With respect to the obtained alumina-coated particle-coupled silica sol, the solid content (alumina-coated particle-coupled silica fine particles) was measured by the solid content measurement method of [4] above, and was found to be 14.4% by weight. Pure water was added to 1463 g of this alumina-coated particle-coupled silica sol to prepare a concentration of 2.7% by weight.

  41 g (corresponding to 10.9 parts by mass of silica with respect to 100 parts by mass of alumina-coated particle-linked silica sol) of No. 3 water glass (silica concentration: 24 wt%) was added to 7163 g of this alumina-coated particle-linked silica sol, After the temperature was raised to 98 ° C., the mixture was aged for 30 minutes, and 2641 g of a silica solution having a silica concentration of 3% by weight (the silica content of the silica solution was 32.4% with respect to 100 parts by mass of the alumina-coated particle-coupled silica fine particles after completion of the aging. (Corresponding to parts by mass) was gradually added over 10 hours with stirring. After completion of the addition, the mixture was aged at 98 ° C. for 1 hour.

Thereafter, concentration is performed while supplying pure water so that the liquid level is always constant at the outer membrane (SIP-1013) until the electric conductivity of the aqueous solution becomes constant, and then the silica concentration becomes 12% by weight. Concentrated to 30% and then concentrated to 30% on a rotary evaporator. Table 5 shows the characteristics of the obtained particle-linked alumina-silica composite sol. Manufacturing conditions are described in Tables 1-4. Further, a scanning electron micrograph of this particle-linked alumina-silica composite sol (magnification: 2)
30000) is shown in FIG.

Particle-coupled silica sol prepared by the method of Synthesis Example 3 (primary average particle diameter 20 nm converted from specific surface area measured by image analysis method, average number of connections 6, specific surface area 139 m ² / g)
Pure water was added to adjust the silica concentration to 15.4% by weight.

1488 g of a 0.9 wt% aqueous solution of sodium aluminate [Chemical Formula: NaAlO ₂ ] at 25 ° C. was added to 6500 g of this particle-coupled silica sol (1 part of sodium aluminate was 100 parts by mass of silica in the particle-coupled silica sol). Equivalent to 34 parts by mass) was added evenly over 6 hours with stirring. And it heated up to 90 degreeC and age | cure | ripened for 3 hours.

  With respect to the obtained alumina-coated particle-coupled silica sol, the solid content (alumina-coated particle-coupled silica sol) was measured by the solid content measurement method of [4] above, and found to be 12.7% by weight. Pure water was added to 882 g of this alumina-coated particle-linked silica sol to prepare a concentration of 2.8% by weight.

  To 4074 g of this alumina-coated particle-coupled silica sol, 48 g of No. 3 water glass (silica concentration 24 wt%) (corresponding to 10.1 parts by mass with respect to 100 parts by mass of alumina-coated particle-coupled silica fine particles) was added, and 87 The mixture was aged for 30 minutes after the temperature was raised to 0 ° C., while maintaining the temperature at 87 ° C., 5961 g of silicic acid solution having a silica concentration of 3% by weight (based on 100 parts by mass of the alumina-coated particle-coupled silica fine particles after completion of the aging) The silica content of the liquid was equivalent to 156.9 parts by mass) and was gradually added with stirring over 7 hours. After completion of the addition, the mixture was aged at 87 ° C. for 1 hour.

  Thereafter, concentration is performed while supplying pure water so that the liquid level is always constant at the outer membrane (SIP-1013) until the electric conductivity of the aqueous solution becomes constant, and then the silica concentration becomes 12% by weight. Concentrated to 30% and then concentrated to 30% on a rotary evaporator. Table 5 shows the characteristics of the obtained particle-linked alumina-silica composite sol. Manufacturing conditions are described in Tables 1-4.

Particle-linked silica sol prepared by the method of Synthesis Example 4 (primary average particle diameter 25 nm converted from specific surface area measured by image analysis method, average number of connected particles 4, specific surface area 108 m ² / g)
Pure water was added to adjust the silica concentration to 15.4% by weight.

At 25 ° C, 142 g of 0.9 wt% aqueous solution of sodium aluminate [chemical formula: NaAlO ₂ ] was added to 6500 g of this particle-coupled silica sol (0.1 parts of sodium aluminate with respect to 100 parts by mass of silica in the particle-coupled silica sol). 13 parts by mass) was added uniformly over 30 minutes with stirring. And it heated up to 90 degreeC and age | cure | ripened for 3 hours.

  The content of the solid content (alumina-coated particle-coupled silica sol) of the obtained dispersion liquid of alumina-coated particle-coupled silica sol was measured by the solid content measurement method of [4] and found to be 15.1% by weight. Pure water was added to 1199 g of this alumina-coated particle-linked silica sol aqueous solution to prepare a concentration of 2.9% by weight.

  27 g of No. 3 water glass (silica concentration 24 wt%) was added to 6243 g of this alumina-coated particle-linked silica sol aqueous solution (equivalent to 4.0 parts by mass with respect to 100 parts by mass of the alumina-coated particle-coupled silica sol), The temperature was raised to 98 ° C. and then aged for 30 minutes. While maintaining the temperature at 98 ° C., 4305 g of silica solution having a silica concentration of 3% by weight On the other hand, the silica content of the silicic acid solution corresponds to 79.7 parts by mass) was gradually added over 7 hours with stirring. After completion of the addition, the mixture was aged at 98 ° C. for 1 hour.

  Thereafter, concentration is performed while supplying pure water so that the liquid level is always constant at the outer membrane (SIP-1013) until the electric conductivity of the aqueous solution becomes constant, and then the silica concentration becomes 12% by weight. Concentrated to 30% and then concentrated to 30% on a rotary evaporator. The characteristics of the obtained particle-linked silica sol are shown in Table 5. Manufacturing conditions are described in Tables 1-4.

Particle-linked silica sol prepared by the method of Synthesis Example 4 (primary average particle diameter 25 nm converted from specific surface area measured by image analysis method, average number of connected particles 4, specific surface area 108 m ² / g)
Pure water was added to adjust the silica concentration to 15.4% by weight.

At 25 ° C., 1983 g of a 0.9 wt% aqueous solution of sodium aluminate [chemical formula: NaAlO ₂ ] was added to 6500 g of this particle-coupled silica sol (1 part of sodium aluminate was 100 parts by mass of silica content of the particle-coupled silica sol). .78 parts by mass) was added evenly over 8 hours with stirring. And it heated up to 90 degreeC and age | cure | ripened for 3 hours.

  The content of solid content (alumina-coated particle-coupled silica fine particles) of the obtained alumina-coated particle-coupled silica sol was measured by the solid content measurement method of [4] and found to be 12.0% by weight. Pure water was added to 1199 g of this alumina-coated particle-coupled silica sol to prepare a concentration of 2.9% by weight.

  To 4552 g of this alumina-coated particle-coupled silica sol, 22 g of No. 3 water glass (silica concentration 24 wt%) was added (corresponding to 4.0 parts by mass with respect to 100 parts by mass of alumina-coated particle-coupled silica fine particles). The mixture was aged for 30 minutes after the temperature was raised to 0 ° C., and while maintaining the temperature at 98 ° C., 4343 g of silica solution having a silica concentration of 3% by weight (based on 100 parts by mass of the alumina-coated particle-linked silica fine particles after completion of the aging) The silica content of the liquid corresponds to 98.7 parts by mass) was gradually added with stirring over 7 hours. After completion of the addition, the mixture was aged at 98 ° C. for 1 hour.

Thereafter, concentration is performed while supplying pure water so that the liquid level is always constant at the outer membrane (SIP-1013) until the electric conductivity of the aqueous solution becomes constant, and then the silica concentration becomes 12% by weight. Concentrated to 30% and then concentrated to 30% on a rotary evaporator. Table 5 shows the characteristics of the obtained particle-linked alumina-silica composite sol. Manufacturing conditions are described in Tables 1-4.
[Comparative Example 1]

Particle-linked silica sol prepared by the method of Synthesis Example 1 (primary average particle diameter 20 nm converted from specific surface area measured by image analysis method, average number of connected particles 4, specific surface area 139 m ² / g)
Pure water was added to adjust the silica concentration to 2.8% by weight.

  No. 3 water glass (silica concentration: 24% by weight) is 4061 g of this particle-coupled silica sol (61 wt%) with respect to 100 parts by mass of the particle-coupled silica sol in the particle-coupled silica sol. The mixture was heated to 98 ° C. and aged for 30 minutes. While maintaining the temperature at 98 ° C., 4199 g of silica solution having a silica concentration of 3% by weight (particle-coupled silica sol 100 in the particle-coupled silica sol 100) The silica content of the silicic acid solution corresponds to 78.2 parts by mass with respect to parts by mass) was gradually added with stirring over 7 hours. After completion of the addition, the mixture was aged at 98 ° C. for 1 hour.

Thereafter, concentration is performed while supplying pure water so that the liquid level is always constant at the outer membrane (SIP-1013) until the electric conductivity of the aqueous solution becomes constant, and then the silica concentration becomes 12% by weight. Concentrated to 30% and then concentrated to 30% on a rotary evaporator. The characteristics of the obtained particle-linked silica sol are shown in Table 5. Manufacturing conditions are described in Tables 1-4.
[Comparative Example 2]

Particle-linked silica sol prepared by the method of Synthesis Example 2 (primary average particle diameter 20 nm converted from specific surface area measured by image analysis method, average number of connections 3, specific surface area 139 m ² / g)
Pure water was added to adjust the silica concentration to 2.8% by weight.

  3972 g of this particle-coupled silica sol is 46 g of No. 3 water glass (silica concentration 24 wt%) (10.0 mass parts of silica of No. 3 water glass with respect to 100 parts by mass of the particle-coupled silica sol in the particle-coupled silica sol). The mixture was heated to 98 ° C. and aged for 30 minutes. While maintaining the temperature at 87 ° C., 5983 g of a silica solution having a silica concentration of 3% by weight (particle-coupled silica sol 100 in the particle-coupled silica sol 100) The silica content of the silicic acid solution corresponds to 161.7 parts by mass with respect to parts by mass) and was gradually added with stirring over 7 hours. After completion of the addition, the mixture was aged at 87 ° C. for 1 hour.

Thereafter, concentration is performed while supplying pure water so that the liquid level is always constant at the outer membrane (SIP-1013) until the electric conductivity of the aqueous solution becomes constant, and then the silica concentration becomes 12% by weight. Concentrated to 30% and then concentrated to 30% on a rotary evaporator. The characteristics of the obtained silica sol are shown in Table 5. Manufacturing conditions are described in Tables 1-4.
[Comparative Example 3]

Particle-linked silica sol prepared by the method of Synthesis Example 1 (primary average particle diameter 20 nm converted from specific surface area measured by image analysis method, average number of connected particles 4, specific surface area 139 m ² / g)
Pure water was added to adjust the silica concentration to 15.4% by weight.

To 25, 000 g of this particle-coupled silica sol, 2833 g of a 0.9 wt% aqueous solution of sodium aluminate [Chemical Formula: NaAlO ₂ ] (2 parts of sodium aluminate was added to 100 parts by mass of silica in the particle-coupled silica sol). Equivalent to .55 parts by mass) was added evenly over 12 hours with stirring. And it heated up to 90 degreeC and age | cure | ripened for 3 hours.

The content of solid content (alumina-coated particle-coupled silica fine particles) of the obtained alumina-coated particle-coupled silica sol was measured by the solid content measurement method of [4] and found to be 11.0% by weight. Pure water was added to 1494 g of this alumina-coated particle-coupled silica sol to prepare a concentration of 2.9% by weight.

  41 g (corresponding to 4.0 parts by mass with respect to 100 parts by mass of alumina-coated particle-linked silica fine particles) of No. 3 water glass (silica concentration: 24% by weight) was added to 8483 g of this alumina-coated particle-linked silica sol, 98 The mixture was aged for 30 minutes after the temperature was raised to 0 ° C., and while maintaining the temperature at 98 ° C., 4190 g of a silica solution having a silica concentration of 3% by weight (based on 100 parts by mass of the alumina-coated particle-linked silica fine particles after completion of the aging) The silica content of the liquid was equivalent to 51.1 parts by mass) and was gradually added with stirring over 7 hours. After completion of the addition, the mixture was aged at 98 ° C. for 1 hour. Thereafter, concentration is performed while supplying pure water so that the liquid level is always constant at the outer membrane (SIP-1013) until the electric conductivity of the aqueous solution becomes constant, and then the silica concentration becomes 12% by weight. Concentrated to 30% and then concentrated to 30% on a rotary evaporator. The characteristics of the obtained silica sol are shown in Table 5. Manufacturing conditions are described in Tables 1-4.

  The particle-coupled alumina-silica composite sol of the present invention is useful as an abrasive and a polishing composition, and includes an aluminum disk (aluminum or a plating layer on a base material thereof), an aluminum wiring of a semiconductor multilayer wiring board, an optical disk and a magnetic material. It can be used for disk glass substrates, liquid crystal display glass substrates, photomask glass substrates, mirror finishing of glassy materials, and the like. It can also be used as a filler for resin moldings and coating films, cosmetic ingredients, adsorbents, aggregation promoters, suspending agents, thickeners, soil hardeners, and the like.

Schematic diagram on how to determine the coefficient of variation of the primary particle radius of particle-linked alumina-silica composite particles Scanning electron micrograph of the particle-linked alumina-silica composite sol prepared in Example 1 (magnification: 250,000 times) Scanning electron micrograph of the particle-linked alumina-silica composite sol prepared in Example 2 (magnification: 250,000 times)

Explanation of symbols

l ... Line segment O ... Center point P ... Outer edge S ... Half line

Claims (6)

Particle-linked alumina-silica composite fine particles having a structure in which two or more alumina-silica composite primary particles having an average particle diameter measured by an image analysis method in the range of 5 to 300 nm are combined are dispersed in a dispersion medium. A particle-coupled alumina-silica composite sol, wherein the particle-coupled alumina-silica composite fine particles include spherical particles having a plurality of hook-shaped protrusions on the surface as primary alumina-silica composite particles. Particle-linked alumina-silica composite sol.   2. The particle-coupled alumina-silica composite sol according to claim 1, wherein the variation coefficient of the radius of the alumina-silica composite primary particles is in the range of 3 to 30%.   An abrasive comprising the particle-linked alumina-silica composite sol according to claim 1 or 2. A polishing composition comprising the particle-linked alumina-silica composite sol according to claim 1.   A particle-coupled silica sol in which two or more spherical silica primary particles having an average particle diameter measured by an image analysis method in the range of 5 to 300 nm bonded together are dispersed in a dispersion medium. Then, 0.1 to 2.5 parts by mass of sodium aluminate is continuously or intermittently added to 100 parts by mass of the particle-coupled silica fine particles, and then aged, thereby aging. After preparing a dispersion of fine particles, and then adding alkali metal silicate corresponding to 0.1 to 100 parts by mass to 100 parts by mass of the alumina-coated particle-coupled silica fine particles and aging, a silicic acid solution is further added. 3. The particle-coupled alumina-silica composite according to claim 1, wherein particles are grown to form protrusions by continuously or intermittently adding. A method for producing a composite sol.   The amount of the silicic acid solution used is in the range of 3 to 700 parts by mass in terms of silica relative to 100 parts by mass of the alumina-coated particle-coupled silica fine particles, and the addition of the silicic acid solution is continuously performed over 2 to 24 hours. 6. The method for producing a particle-linked alumina-silica composite sol according to claim 5, wherein the method is carried out intermittently.