JP4949209B2 - Non-spherical alumina-silica composite sol, method for producing the same, and polishing composition - Google Patents

Description

  The present invention relates to a non-spherical silica sol in which non-spherical silica fine particles having a plurality of hook-shaped protrusions on the surface of non-spherical alumina-silica composite fine particles serving as a nucleus are dispersed in a dispersion medium, and a method for producing the same. . The present invention also relates to a polishing composition containing the non-spherical silica sol.

  Among non-spherical silica sols in which non-spherical silica fine particles are dispersed in a solvent, chain-like, beaded, or oval spherical ones are known as non-spherical silica sols having non-spherical silica fine particles having a shape other than spherical. Such non-spherical silica sols are used as various abrasives, for example.

As a method for producing non-spherical silica sol containing irregular particles, JP-A to 1-317115 (Patent Document 1), particle diameter measured by the image analysis method particle diameter measured by (D ₁₎ and the nitrogen gas adsorption method (D ₂ ) Ratio D ₁ / D ₂ is 5 or more, D ₁ is 40-500 millimicrons, and stretched only in one plane with uniform thickness in the range of 5-40 millimicrons by electron microscope observation As a method for producing a non-spherical silica sol in which amorphous colloidal silica particles having an elongated shape are dispersed in a liquid medium, (a) a predetermined colloidal aqueous solution of active silicic acid contains a water-soluble calcium salt or magnesium salt (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 of organic base A production method comprising a step of adding and mixing so that the molar ratio is 20 to 200, and (c) heating the mixture obtained in the previous step at 60 to 150 ° C. for 0.5 to 40 hours. Has been.

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. % Of a stable non-spherical silica sol, when the addition of an aqueous solution of active silicic acid to an elongated non-spherical silica sol is started, the colloidal silica particles of the raw material sol do not collapse and the original elongated particles It is disclosed that elongated colloidal silica of increased thickness is obtained by depositing added active silicic acid on the surface via siloxane bonds.

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 non-spherical silica fine particles are 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 method for producing an elongated non-spherical silica sol comprising concentrating to a concentration of 6 to 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 a method of directly dispersing in an aqueous medium is usually 4 to 1,000 nm (nanometer), preferably 7 to
Colloidal silica particles having a particle diameter of 500 nm are dispersed in an aqueous medium and have a concentration of 0.5 to 50% by weight, preferably 0.5 to 30% by weight as SiO ₂ . 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 non-spherical silica sol in which beaded colloidal silica particles in which silica particles are connected only in one plane is dispersed is described.

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 non-spherical silica sol, and a metal oxide with respect to SiO _{2 of the} colloidal aqueous solution or acidic non-spherical silica sol. (B) A step of preparing a mixed solution 1 by adding an amount of 1 to 10% by weight, (b) An acidic spherical non-spherical silica sol having an average particle size of 10 to 80 nm and a pH of 2 to 6 is added to the mixed solution 1 The ratio A / B (weight ratio) of the silica content (A) derived from the non-spherical silica sol and the silica content (B) derived from the mixed solution 1 is 5 to 100, and the acidic spherical non-spherical silica sol and the mixed solution A step of adding and mixing the total silica content (A + B) of the mixed solution 2 obtained by mixing with 1 to an SiO ₂ concentration of 5 to 40% by weight in the mixed solution 2, and (c) the obtained mixed solution 2 In There is described a method for producing the non-spherical silica sol comprising a step of adding an alkali metal hydroxide, a water-soluble organic base or a water-soluble silicate so as to have a pH of 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, an acidic spherical non-spherical silica sol having an average particle diameter 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 non-spherical silica sol and the mixed liquid (1 The ratio A / B (weight ratio) of the silica content (B) derived from One, a SiO ₂ concentration of 5 to 40 wt% in the total silica content of the acidic spherical non-spherical silica sol and the mixture (1) and the resulting mixture by mixing (2) (A + B) is a mixture (2) The mixture (2) was mixed with an alkali metal hydroxide or the like so as to have a pH of 7 to 11, and the resulting mixture (3) was mixed at 100 to 200 ° C. with 0.5. A method for producing a beaded non-spherical silica sol heated for ˜50 hours 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 non-spherical 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. Non-spherical silica sol having a distorted shape formed by adding (or without) evaporating and removing 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 The manufacturing method 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 abrasive 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.

Moreover, about chain | strand-shaped non-spherical silica sol coated with silica-alumina, JP-A No. 2002-3212 (Patent Document 15) discloses (a) Alkali metal silicic acid of 0.05 to 5.0% by weight as SiO _2. A step of adding a silicic acid solution to the aqueous salt solution to adjust the SiO ₂ / M ₂ O (molar ratio, M is an alkali metal or quaternary ammonium) of the mixed solution to 30 to 60, (b) addition of the silicic acid solution Before the step, during the addition step or after the addition step, a step of adding one or two or more metal compounds having a valence of 2 to 4; (c) A step of maintaining at a temperature for a certain period of time, (d) a step of adding a silicic acid solution to the reaction solution again to adjust SiO ₂ / M ₂ O (molar ratio) in the reaction solution to 60 to 200, (e) further Alkaline silicate aqueous solution and alkali Adding the Riarumin salt solution simultaneously, silica consists - method for producing alumina coated linear non-spherical silica sol 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 surface-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 non-spherical alumina-silica composite fine particles dispersed in a dispersion medium and having excellent properties such as polishing properties, 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.

The present invention for solving the above problems is as follows.
The average particle diameter measured by the dynamic light scattering method is in the range of 3 to 150 nm, the short diameter / long diameter ratio is in the range of 0.01 to 0.8, the specific surface area is in the range of 10 to 800 m ² / g, and the surface A non-spherical alumina-silica composite sol, wherein non-spherical alumina-silica composite fine particles having a plurality of hook-shaped protrusions are dispersed in a dispersion medium,
As a preferred embodiment of the non-spherical alumina-silica composite sol,
On a plane including the long axis of the non-spherical alumina-silica composite fine particle, from any point on the outer edge of the non-spherical alumina-silica composite fine particle, a straight line passing through the point on the outer edge and orthogonal to the long axis; An XY curve was drawn where Y was the distance to the intersection B with the major axis, and X was the distance from one intersection A between the outer edge of the non-spherical alumina-silica composite fine particle to the major axis. The XY curve has a plurality of local maxima,
On a plane including the long axis of the non-spherical alumina-silica composite fine particle, from any point on the outer edge of the non-spherical alumina-silica composite fine particle, a straight line passing through the point on the outer edge and orthogonal to the long axis; When the distance to the intersection B with the long axis is Y, the variation coefficient of the distance Y is in the range of 5 to 50%.

Other inventions are:
Nonspherical particles in which nonspherical silica fine particles having an average particle diameter measured by a dynamic light scattering method in the range of 3 to 150 nm and a minor axis / major axis ratio in the range of 0.01 to 0.8 are dispersed in a dispersion medium. Alumina-coated non-spherical silica fine 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 non-spherical silica fine particles and then aging the silica sol. Next, an alkali metal silicate corresponding to 0.1 to 100 parts by mass is added to 100 parts by mass of the alumina-coated non-spherical silica fine particles, and after aging, the silicic acid solution is continuously added. The method for producing the non-spherical alumina-silica composite sol is characterized in that particles are grown and formed into protrusions by adding them intermittently or intermittently,
As a preferred embodiment of the method for producing the non-spherical alumina-silica 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 non-spherical silica fine particles, and the addition of the silicic acid solution is continuously performed over 2 to 24 hours. Or do it intermittently.

Another invention is an abrasive comprising the non-spherical alumina-silica composite sol.
Another invention is a polishing composition comprising the non-spherical alumina-silica composite sol.

The non-spherical alumina-silica composite fine particles contained in the non-spherical alumina-silica composite sol according to the present invention have a unique structure different from ordinary non-spherical silica fine particles.
Excellent oil absorption, electrical properties, optical properties and physical properties. For this reason, the non-spherical alumina-silica composite sol according to the present invention is useful, for example, as an abrasive and a polishing composition, and is particularly excellent in the effect of the polishing rate.

[Non-spherical alumina-silica composite sol]
The non-spherical alumina-silica composite sol of the present invention has an average particle diameter measured by a dynamic light scattering method in a range of 3 to 150 nm, a minor axis / major axis ratio in a range of 0.01 to 0.8, and a specific surface area. The non-spherical alumina-silica composite fine particles having a range of 10 to 800 m ² / g and having a plurality of hook-shaped protrusions on the surface are dispersed in a dispersion medium. Here, the alumina-silica composite fine particles are fine particles composed of a portion made of alumina and a portion made of silica.

  The non-spherical alumina-silica composite fine particles that are the dispersoid of the non-spherical alumina-silica composite sol according to the present invention preferably have a minor axis / major axis ratio in the range of 0.01 to 0.8. In the case of the minor axis / major axis ratio in this range, a shape that is regarded as an unusual shape such as a fiber shape, a column shape, or a spheroid shape, that is, a shape that is not regarded as a spherical shape is taken. When the minor axis / major axis ratio exceeds 0.8, the particles are almost spherical. The case where the minor axis / major axis ratio is less than 0.01 includes the case where the production is not easy. A more preferable range of the minor axis / major axis ratio is 0.1 to 0.7, and an even more preferable range is 0.12 to 0.65.

The non-spherical alumina-silica composite sol according to the present invention is different from the conventional non-spherical alumina-silica composite sol in that the dispersoid non-spherical alumina-silica composite fine particles have a plurality of hook-shaped protrusions on the surface. It is different in structure from the first non-spherical silica sol. Due to the presence of the hook-shaped protrusions, it is possible to exhibit unique effects in various applications, for example, applications such as polishing, fillers for resin or film forming components, and fillers for ink receiving layers. 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.
About the non-spherical alumina-silica composite fine particles, preferably, from any point on the outer edge of the non-spherical alumina-silica composite fine particles on a plane including the long axis of the non-spherical alumina-silica composite fine particles, The distance to the intersection B between the long axis passing through a point on the outer edge and the straight line perpendicular to the major axis is Y, from one intersection A of the outer edge of the non-spherical alumina-silica composite fine particle and the major axis, When an XY curve is drawn with the distance to the intersection B as X, it is desirable that the XY curve has a plurality of maximum values. This is the most nonspherical of the straight lines passing through the non-spherical alumina-silica composite fine particles in the scanning electron micrograph (250,000 to 500,000 times) of the non-spherical alumina-silica composite fine particles. The long axis passing through the alumina-silica composite fine particle is defined as the major axis, the entire length of the major axis is divided into 40 equal parts, and each point (point B) and the straight line perpendicular to that point are divided into the fine particles. Stretching to one side and recording the distance from the point of intersection with the outer edge of the fine particles as Y. In addition, the distance between one point (point A) of the two intersections between the outer edge of the non-spherical alumina-silica composite fine particle and the major axis and the corresponding point (point B) is X. . By plotting the Y value corresponding to each X with the Y as the vertical axis and the X as the horizontal axis, the XY curve can be drawn, and the number of local maximum values of the XY curve can be measured. In the present application, the nonspherical alumina-silica composite fine particles are subjected to such a measurement for 50 particles, and the average of the maximum number of particles is 2 or more. Therefore, it is assumed that the plurality of local maximum values are handled. An outline of how to determine the number of local maximum values is shown in FIG. Note that the number of maximum values may be obtained by measurement with an analytical instrument.

The non-spherical alumina-silica composite fine particles are more preferably a point on the outer edge from an arbitrary point on the outer edge of the non-spherical alumina-silica composite fine particles on a plane including the long axis of the fine particles. It is preferable that the variation coefficient of the distance Y is in the range of 5 to 50%, where Y is the distance to the intersection B between the straight line passing through the long axis and the long axis. In the present invention, the coefficient of variation of the distance Y from the outer edge of the fine particle to the long axis was calculated by the following method.
1) Measure the distance (major axis radius M) from the center point of the major axis (located at a position that bisects the major axis of the particulate) to one of the outer edges of the particulate on the major axis. Next, the length of the major axis radius M from the center point is plotted in a range of 0 to 50% in 5% increments.
2) A straight line perpendicular to the major axis is drawn in each plot, and the distance Y from the point where the straight line intersects the outer edge of the fine particle on one side to the plot is measured.
3) About the coefficient of variation (CV value) for the distance Y from the outer edge of the fine particle to the long axis, on the long axis, the range of 0 to 10% of the long axis radius M from the center point is 0 to 20%. The variation coefficient (CV value) of distance Y is calculated in each of the range, the range of 0 to 30%, the range of 0 to 40%, and the range of 0 to 50% to obtain five types of variation coefficients (CV values). The maximum coefficient of variation (CV value) among them is defined as the coefficient of variation (CV value) for the distance Y in the particle.
4) The above measurements 1) to 3) were carried out on 50 particles, and the average value was taken as the coefficient of variation (CV value) for the distance Y in the non-spherical alumina-silica composite fine particles. An outline of how to obtain the coefficient of variation of the distance Y value is shown in FIG.

The variation coefficient (CV value) of the distance Y is the relationship of the variation coefficient (CV value) [%] of the distance Y = (standard deviation of the distance Y (σ) / average value of the distance Y (Ya)) × 100. It is obtained from the formula.
As described above, from a point on the outer edge of the non-spherical alumina-silica composite fine particle on a plane including the long axis of the non-spherical alumina-silica composite fine particle, the point on the outer edge passes through and is orthogonal to the long axis. XY curve where Y is the distance to the intersection B between the straight line and the major axis, and X is the distance from one intersection A between the outer edge of the non-spherical alumina-silica composite fine particle to the major axis. When the XY curve has a plurality of maximum values, the non-spherical alumina-silica composite fine particles have ridge-like projections. In such non-spherical alumina-silica fine particles, When the coefficient of variation (CV value) for the distance Y from the outer edge to the long axis is in the range of 5 to 50%, there is a significant variation in the length of the distance Y from the outer edge of the particle to the long axis. Indicating and non-spherical Na - and thus indicate that there is undulating silica fine particle surface.

  When the average number of the maximum values is 2 or more and the coefficient of variation (CV value) for the distance Y from the outer edge to the long axis is less than 5%, the surface of the non-spherical alumina-silica fine particles is slightly undulated. Or a case where there is substantially no undulation. When the coefficient of variation (CV value) for the distance Y from the outer edge to the long axis is 50% or more, it is not easy to prepare, and such particles have a problem in robustness due to the structure. May come out.

The coefficient of variation (CV value) for the distance Y from the outer edge to the long axis is more preferably in the range of 10 to 35%. Moreover, the range of 11-25% is more preferable.
The average particle size of the non-spherical alumina-silica composite fine particles, which are the dispersoid of the non-spherical alumina-silica composite sol according to the present invention, is preferably in the range of 3 to 150 nm in the average particle size measured by the dynamic light scattering method. . If the average particle diameter is in this range, for example, in each of the above applications, an effective effect based on the shape of the non-spherical alumina-silica composite sol according to the present invention is likely to occur. When the average particle diameter exceeds 150 nm, although depending on the size of the raw material fine particles, the tendency to flatten the hook-shaped projections is generally increased because the built-up process generally proceeds excessively. When the average particle diameter is less than 3 nm, it is not easy to prepare non-spherical alumina-silica fine particles as a raw material.

For the non-spherical alumina-silica composite fine particles having an average particle diameter range of 3 to 150 nm by the dynamic light scattering method, the long axis average diameter by an image analysis method is in the range of 7 to 180 nm. Spherical alumina-silica composite fine particles correspond. Here, the long axis means the maximum diameter of the non-spherical alumina-silica composite fine particles. In the present application, the image analysis method means the maximum diameter of particles measured in a scanning electron micrograph (magnification 250,000 to 500,000 times). Specific measurement methods are shown in the examples.

The solvent in which the alumina-nonspherical silica fine particles are dispersed may be water, an organic solvent, or a mixed solvent thereof. Examples thereof include alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol, water-soluble organic solvents such as ethers, esters and ketones.
[Method for producing non-spherical alumina-silica composite sol]
The method for producing an alumina-silica composite sol of the present invention is such that the average particle diameter measured by the dynamic light scattering method is in the range of 3 to 140 nm and the short diameter / long diameter ratio is in the range of 0.01 to 0.8. 0.1 to 2.5 parts by mass of sodium aluminate is continuously or intermittently added to 100 parts by mass of the non-spherical silica fine particles in a non-spherical silica sol in which spherical silica fine particles are dispersed in a dispersion medium. Then, a dispersion of alumina-coated non-spherical silica fine particles is prepared by aging, and then alkali metal silicate corresponding to 0.1 to 100 parts by mass with respect to 100 parts by mass of the alumina-coated non-spherical silica fine particles. Is added, and after aging, a silicic acid solution is added continuously or intermittently to grow particles and form protrusions.
Raw material non-spherical silica sol In the method for producing an alumina-silica composite sol of the present invention, the non-spherical silica sol used as a raw material is not particularly limited, and a commercially available non-spherical silica sol or a known non-spherical silica sol is used. be able to. The manufacturing method is not particularly limited.

Examples of known methods for producing non-spherical silica sols include, but are not limited to, the following production methods.
A silicic acid solution is added to an aqueous solution of a water-soluble silicate, and SiO ₂ / M ₂ O [M is selected from alkali metals, tertiary ammonium, quaternary ammonium or guanidine] (molar ratio) is 30 to 30 A mixed solution in the range of 65 is prepared, and a silica sol is prepared by adding the silicic acid solution intermittently or continuously again at a temperature of 60 to 200 ° C., and the silica sol is adjusted to a pH in the range of 7 to 9. The method for producing an anisotropic shaped silica sol characterized by heating at 60 to 98 ° C. (see JP2007-153671)
In a silica sol in which silica fine particles having an average particle diameter in the range of 3 to 25 nm are dispersed and having a pH in the range of 2 to 8, 0.01 parts of the polymetal salt compound is added to 100 parts by weight of the silica solid content of the silica sol. Addition of ˜70 parts by weight and heating at 50 to 160 ° C. (see Japanese Patent Application Laid-Open No. 2007-153672)
Silica sol having an average particle size in the range of 3 to 20 nm is decationized and adjusted to a pH of 2 to 5, then deanionized, and then adjusted to pH 7 to 9 by adding an alkaline aqueous solution. A method for producing an anisotropic shaped silica sol, characterized by heating at 60 to 250 ° C. (see JP2007-145633)
An alkaline aqueous solution is added to the silicic acid solution (a) to adjust the pH to 10.0 to 12.0, and the silicic acid solution (b) and a divalent or higher water-soluble metal salt are heated under a temperature condition of 60 to 150 ° C. A method for producing an anisotropic silica sol, wherein the mixture is added continuously or intermittently (see JP2007-153692A)
A method for producing anisotropic silica sol by the following steps (1) and (2) (see WO2007 / 018069).
(1) The silica hydrogel obtained by neutralizing silicate with an acid is washed to remove salts, and the molar ratio of SiO ₂ / M ₂ O (M: Na, K, NH ₃ ) is 30 to 500. (2) Step of obtaining silica sol by heating in a range of 60 to 200 ° C. after adding alkali so that the pH becomes 9 to 12.5, temperature 60 to The step of adding the silicic acid solution continuously or intermittently under the condition of 200 ° C. In the method of the present invention, the non-spherical silica sol of such raw material is diluted with pure water as necessary to adjust the silica solid content concentration. It is desirable to adjust to 2 to 40%.

The non-spherical silica sol used as a raw material is a silica sol having a short diameter / long diameter ratio in the range of 0.01 to 0.8, and is a dispersoid of the non-spherical alumina-silica composite sol to be obtained. Those having an average particle diameter smaller than or equivalent to those of non-spherical alumina-silica composite fine particles are used. Note that the non-spherical silica fine particles, which are dispersoids of the non-spherical silica sol used as a raw material, preferably have an average particle diameter in the range of 3 to 140 nm by a dynamic light scattering method, and the minor axis / major axis ratio is 0.00. The thing in the range of 01-0.8 is desirable. In addition, the specific surface area of such non-spherical silica fine particles is preferably in the range of, for example, 5 to 800 m ² / g.
Sodium aluminate In the production method of the present invention, an alumina-coated non-spherical structure in which an aqueous solution of sodium aluminate (NaAlO ₂ ) is added to a raw non-spherical silica sol, and alumina is present in the form of spots on the non-spherical silica fine particles. Silica fine particles are prepared.

  Sodium aluminate (solid content concentration) is in the range of 0.1 to 2.5 parts by weight, preferably 0.1 to 2.0 parts by weight with respect to 100 parts by weight of the nonspherical silica fine particles contained in the raw material nonspherical silica sol. Used in the range of parts by mass. When the amount of sodium aluminate used is in this range, the surface of the non-spherical silica fine particles is not completely covered with alumina, and is almost covered with alumina. The surface of such alumina-coated non-spherical silica fine particles is presumed to form a chemical structure represented by the following formula (1).

Here, the vicinity of the Al atom is higher in water solubility than the vicinity of the Si atom, so that it becomes a starting point of particle growth during the subsequent particle growth, and a plurality of protruding portions are formed on the surface of the non-spherical silica fine particles. 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 less than 10 ° C., the reaction of sodium aluminate on the surface of the non-spherical silica fine particles is low, so that it is difficult to form a spot-like coating with alumina.

  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 all at once, the surface of the non-spherical silica fine particles 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 non-spherical silica sol, the raw material non-spherical silica sol is sufficiently stirred.
After adding the sodium aluminate aqueous solution to the raw material non-spherical silica sol, it is necessary to perform aging in order 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 non-spherical silica sol obtained in the particle growth process, before adding the silicic acid solution, add an alkali metal silicate, perform seeding, then grow the particles by adding the silicic acid solution, and further aged 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 non-spherical silica sol obtained in the previous step. Since the alkali metal silicate is added, the concentration of SiO ₂ dissolved in the dispersion medium is set high in advance when adding the silica solution for particle growth, so the alumina-coated non-spherical silica fine particles that are the core particles Precipitation of silicic acid on the surface 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 non-spherical silica sol is usually performed at room temperature to 99 ° C., but preferably at room temperature.
The addition amount of the alkali metal silicate to the alumina-coated non-spherical silica sol is 0.1 to 100 parts by mass with respect to 100 parts by mass of the alumina-coated particle-linked silica fine particles. It is preferable to add the alkali metal silicate so that the partial 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.

  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 an alumina-silica composite fine particle dispersion. In addition, an alumina-silica composite fine particle dispersion in which an aqueous solvent is substituted with the above organic solvent by an ultrafiltration membrane method, a distillation method, or the like can also be obtained.
[Abrasive and polishing composition]
The non-spherical 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). It is.

  The polishing composition according to the present invention is such that the above-mentioned non-spherical alumina-silica composite fine particles are dispersed 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 non-spherical alumina-silica composite fine particles in the polishing composition is preferably 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, add acid such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, polyphosphoric acid, amidosulfuric acid, hydrofluoric acid or the like, or add sodium salt, potassium salt, ammonium salt or a mixture thereof. Can do. 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. Other examples of the organic acid include carboxylic acid, organic phosphoric acid, and amino acid. Examples of carboxylic acids include monovalent carboxylic acids such as acetic acid, glycolic acid, and ascorbic acid, divalent carboxylic acids such as succinic acid and tartaric acid, and trivalent carboxylic acids such as citric acid. -Aminoethylphosphonic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, aminotri (methylenephosphonic acid), ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid) and the like. Examples of amino acids include glycine and alanine. Among these,
From the viewpoint of reducing scratches, inorganic acids, carboxylic acids and organic phosphoric acids are preferable. For example, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, polyphosphoric acid, glycolic acid, succinic acid, citric acid, aminotri (methylenephosphonic acid), ethylenediaminetetra ( Methylenephosphonic acid) and diethylenetriaminepenta (methylenephosphonic acid) are suitable. These acids can be used as an acid for adjusting the pH.

  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.

Preferred embodiment 1
Non-spherical shape in which the average particle diameter measured by the dynamic light scattering method is in the range of 3 to 150 nm, the minor axis / major axis ratio is in the range of 0.01 to 0.8, and the specific surface area is in the range of 10 to 800 m ² / g. Alumina
In a non-spherical alumina-silica composite sol in which silica fine particles are dispersed in a dispersion medium, the non-spherical alumina-silica composite fine particles have a plurality of hook-shaped protrusions on the surface. On a plane including the long axis, a distance from an arbitrary point on the outer edge of the non-spherical alumina-silica composite fine particle to an intersection B of the straight line passing through the point on the outer edge and orthogonal to the long axis Y, and when the XY curve is drawn with the distance from one intersection A between the outer edge of the non-spherical alumina-silica composite fine particles and the long axis to the intersection B as X, the XY curve is A non-spherical alumina-silica composite sol having a plurality of maximum values.

Preferred embodiment 2
Non-spherical shape in which the average particle diameter measured by the dynamic light scattering method is in the range of 3 to 150 nm, the minor axis / major axis ratio is in the range of 0.01 to 0.8, and the specific surface area is in the range of 10 to 800 m ² / g. In a non-spherical alumina-silica composite sol in which composite silica fine particles are dispersed in a dispersion medium, the non-spherical alumina-silica composite fine particles have a plurality of hook-shaped protrusions on the surface, and the non-spherical alumina-silica composite fine particles The length from an arbitrary point on the outer edge of the non-spherical alumina-silica composite fine particle to the intersection B of the straight line passing through the point on the outer edge and perpendicular to the major axis on a plane including the major axis. When the XY curve is drawn with X being the distance from one intersection A between the outer edge of the non-spherical composite silica fine particle and the major axis to X, the X-Y curve is plural. It has a local maximum of Further, on a plane including the long axis of the non-spherical alumina-silica composite fine particle, a straight line passing through a point on the outer edge and perpendicular to the long axis from any point on the outer edge of the non-spherical alumina-silica composite fine particle A non-spherical alumina-silica composite sol in which the coefficient of variation of Y is in the range of 5 to 50%, where Y is the distance to the intersection B with the major axis.

Preferred embodiment 3
Non-spherical shape in which the average particle diameter measured by the dynamic light scattering method is in the range of 3 to 150 nm, the minor axis / major axis ratio is in the range of 0.01 to 0.8, and the specific surface area is in the range of 10 to 800 m ² / g. Alumina
In a non-spherical alumina-silica composite sol in which silica composite fine particles are dispersed in a dispersion medium, the non-spherical alumina-silica composite fine particles have a plurality of hook-shaped protrusions on the surface, and the non-spherical alumina-silica composite fine particles From an arbitrary point on the outer edge of the non-spherical alumina-silica composite fine particle to a crossing point B between the straight line passing through the point on the outer edge and perpendicular to the major axis, on the plane including the major axis When the XY curve is drawn with the distance Y being the distance from one intersection A between the outer edge of the non-spherical alumina-silica composite fine particle and the long axis to the intersection B, the XY curve Has a plurality of maximum values, a polishing composition containing a non-spherical alumina-silica composite sol.

Preferred embodiment 4
Non-spherical shape in which the average particle diameter measured by the dynamic light scattering method is in the range of 3 to 150 nm, the minor axis / major axis ratio is in the range of 0.01 to 0.8, and the specific surface area is in the range of 10 to 800 m ² / g. Alumina
In the non-spherical alumina-silica composite sol in which the silica composite fine particles are dispersed in a dispersion medium, the non-spherical alumina-silica composite fine particles have a plurality of hook-shaped protrusions on the surface. On a plane including the long axis, a distance from an arbitrary point on the outer edge of the non-spherical alumina-silica composite fine particle to an intersection B of the straight line passing through the point on the outer edge and orthogonal to the long axis Y, and when the XY curve is drawn with the distance from one intersection A between the outer edge of the non-spherical alumina-silica composite fine particles and the long axis to the intersection B as X, the XY curve is The outer edge has a plurality of maximum values, and further, from an arbitrary point on the outer edge of the non-spherical alumina-silica composite fine particle on a plane including the long axis of the non-spherical alumina-silica composite fine particle. The variation coefficient of the distance Y is in the range of 5 to 50%, where Y is the distance to the intersection point B between the long axis and the straight line passing through the point and the long axis. A polishing composition comprising a spherical alumina-silica composite sol.

Preferred embodiment 5
The average value of major axis measured by dynamic light scattering method is in the range of 7 to 180 nm, the minor axis / major axis ratio is in the range of 0.01 to 0.8, and the specific surface area is in the range of 10 to 800 m ² / g. In a non-spherical alumina-silica composite sol in which non-spherical composite silica fine particles are dispersed in a dispersion medium, the non-spherical alumina-silica composite fine particles have a plurality of hook-shaped projections on the surface, and the non-spherical alumina-silica composite From an arbitrary point on the outer edge of the non-spherical alumina-silica composite fine particle to an intersection B of the straight line passing through the point on the outer edge and perpendicular to the long axis on a plane including the long axis of the fine particle When the XY curve is drawn with the distance from one intersection point A between the outer edge of the non-spherical composite silica fine particles and the long axis as X, and the distance from the intersection point B as X, the XY curve is Have multiple maxima Further, on a plane including the major axis of the non-spherical alumina-silica composite fine particles, from any point on the outer edge of the non-spherical alumina-silica composite fine particles, passing through the point on the outer edge and orthogonal to the major axis. A non-spherical alumina-silica composite sol, wherein the variation coefficient of Y is in the range of 5 to 50%, where Y is the distance to the intersection B of the straight line and the long axis.

[Analysis methods used in Examples and Comparative Examples]
Hereinafter, preferred examples of the present invention will be described. The 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 Table 1.
[1] Average particle diameter measurement by dynamic light scattering method About the average particle diameter measured by the dynamic light scattering method, a particle size distribution measuring apparatus (manufactured by Particle Sizing Systems, Inc .: The average particle size was measured using NICOMP MODEL380).
[2] Method for measuring the maximum number of distances Y from the outer edge of the particle to the long axis The length of the nonspherical silica fine particles in the image of a scanning electron micrograph (250,000 to 500,000 times) of the nonspherical silica fine particles Set the axis, divide the entire length of the major axis into 40 equal parts, and draw the distance between each point (point B) for the time being and the point intersecting the outer edge of the fine particle by extending a straight line perpendicular to that point to one side of the fine particle Record as Y. Further, let X be the length of one point (point A) of the two intersections between the outer edge of the non-spherical silica fine particle and the long axis, and the corresponding point (point B). By plotting the Y value corresponding to each X with the Y as the vertical axis and the X as the horizontal axis, the XY curve can be drawn, and the number of local maximum values of the XY curve can be measured. In the present application, such a measurement was performed for 50 particles of non-spherical silica fine particles, and the average of the number of local maximum values was taken as the maximum number of distances Y from the outer edge of the particle to the major axis.
[3] Method for calculating the coefficient of variation (CV value) of the distance Y from the outer edge of the particle to the long axis The measurement of the coefficient of variation of the distance Y from the outer edge of the fine particle to the long axis in the present invention is calculated by the following method. did.
1) The distance (major axis radius M) from the center point of the major axis to the outer edge of one fine particle is measured, and plotted from 0 to 50% in increments of 5% from the center point to the major axis radius M on the major axis.
2) A straight line perpendicular to the major axis is drawn in each plot, and the distance Y from the point where this straight line intersects the outer edge of the fine particle on one side to the plot is measured.
3) Regarding the coefficient of variation (CV value) for the distance Y from the outer edge of the fine particle to the long axis, on the long axis, the range of 0 to 10% of the long axis radius M from the center point is 0 to 20%. Each variation coefficient (CV value) is calculated in the range, 0-30% range, 0-40% range, 0-50% range to obtain five types of variation coefficients (CV value), of which The maximum variation coefficient (CV value) is defined as the variation coefficient (CV value) for the distance Y in the particle.
4) The above measurements 1) to 3) are performed on 50 particles, and the average value is adopted as the coefficient of variation (CV value) for the distance Y in the non-spherical silica fine particles.
[4] Specific surface area 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 reactor (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).
V = (A × f × 100 × 1.5) / (W × C) (2)
SA = 29.0V-28 (3)
D1 = 6000 / (ρ × SA) (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)
[5] Specific surface area measurement by BET method (nitrogen adsorption method) 50 ml of non-spherical silica sol was adjusted to pH 3.5 with HNO ₃ and 1-propanol 40 m
1 was added, and the sample 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 above mixed gas, the amount of nitrogen desorbed during that time was detected, and the specific surface area of the non-spherical 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.
[6] Measurement of average value of major axis of non-spherical alumina-silica composite fine particles by image analysis method Using a scanning electron microscope (H-800, manufactured by Hitachi, Ltd.), the magnification of non-spherical alumina-silica composite sol is 250,000 times. In a photograph projection view obtained by taking a photograph at (or 500,000 times), the maximum diameter of the particles was taken as the major axis, and the length was measured. This measurement was performed on arbitrary 50 particles, and the average value was taken as the average value of the major axis.
[7] Measuring method of ratio of minor axis / major axis Obtained by photographing a sample non-spherical silica sol at a magnification of 250,000 times (or 500,000 times) with a scanning electron microscope (H-800, manufactured by Hitachi, Ltd.) In the photograph projection view, the maximum diameter of the particles was taken as the major axis, the length was measured, and the value was taken as the major diameter (DL). Further, a point that bisects the major axis on the major axis was determined, two points where a straight line perpendicular to the major axis intersected with the outer edge of the particle were determined, and a distance between the two points was measured to obtain a minor axis (DS). And ratio (DS / DL) was calculated | required. This measurement was performed on any 50 particles, and the average value was defined as the minor axis / major axis ratio. When a plurality of major axes can be set for one particle, an average value of a plurality of corresponding minor axis lengths was obtained and used as the minor axis length (DS).
[8] Solid content measurement of alumina-coated non-spherical silica fine particle dispersion 2 g of sample (alumina-coated non-spherical silica fine particle dispersion) was evaporated to dryness with a crucible, and the obtained solid was calcined at 1000 ° C. for 1 hour. Place in a desiccator, cool and weigh. The content of the alumina-coated non-spherical silica fine particles was determined from these weight differences.
[9] Evaluation method of polishing characteristics for aluminum substrate
Preparation of polishing slurry Sample silica sol was adjusted to a silica concentration of 20% by mass, H ₂ O ₂ , HEDP (1-hydroxyethylidene-1,1-disulfonic acid) and ultrapure water were added, and 9 wt% silica, H A polishing slurry of 0.5% by weight of ₂ O _{2 and} 0.5% by weight of 1-hydroxyethylidene-1,1-disulfonic acid was prepared, and HNO ₃ was further added as necessary to prepare a polishing slurry having a pH of 2. Prepared.
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 change in weight of the substrate to be polished before and after polishing was determined to calculate the polishing rate [nm / min].
Measurement of scratches (line marks) Regarding the occurrence of scratches, after polishing an aluminum disk substrate in the same manner as described above, an ultra-fine defect / visualization macro device (manufactured by VISION PSYTEC, product name: Micro-MAX) The entire surface was observed with a Zoom 15, and the number of scratches (linear traces) on the polished substrate surface corresponding to 65.97 cm ² was counted and totaled.
[10] Evaluation method of polishing characteristics for glass substrate
Preparation of Polishing Slurry The sample silica sol was adjusted to a silica concentration of 20% by mass, and ultrapure water and a 5% by mass sodium hydroxide aqueous solution were added to prepare a polishing slurry of 9% silica by weight and pH 10.5. Polished substrate A glass substrate for hard disk made of 65 mmφ tempered glass was used as the substrate to be polished. This glass substrate for hard disk has been ground and has a surface roughness of 0.2
1 μm.
Polishing test The above substrate to be polished was set in a polishing apparatus (manufactured by Nano Factor Co., Ltd .: NF300), and a polishing pad (“Apollon” manufactured by Rodel) was used and polished at a substrate load of 0.18 MPa and a table rotation speed of 30 rpm. Polishing was performed by supplying the slurry for 10 minutes at a rate of 20 g / min.

The change in weight of the substrate to be polished before and after polishing was determined to calculate the polishing rate [nm / min].
Measurement of scratches (line marks) Regarding the occurrence of scratches, after polishing the glass substrate in the same manner as described above, an ultrafine defect / visualization macro apparatus (product name: Micro-MAX, manufactured by VISION PSYTEC) was used. The entire surface was observed with Zoom ^1, and the number of scratches (linear traces) on the polished substrate surface corresponding to 65.97 cm ² was counted and totaled.
[Synthesis Example 1]

18.7 g of a sodium silicate aqueous solution (SiO ₂ / Na ₂ O molar ratio 3) having a SiO ₂ concentration of 24 wt% was placed in a separable flask equipped with a reflux condenser and a stirrer, and 837 g of water was further added to prepare 855 g of an aqueous sodium silicate solution. . Next, sodium silicate (SiO ₂ / Na ₂ O molar ratio: 3) having a SiO ₂ concentration of 4.82% by weight was passed through the cation exchange resin tower through this sodium silicate aqueous solution to obtain a SiO ₂ concentration of 4.82. Wt% silicic acid solution (pH 2.3, Si
By adding 1,067 g of O ₂ / Na ₂ O molar ratio = 1200), a mixed liquid (SiO ₂ / Na ₂ O molar ratio 35) composed of a silicic acid solution and a sodium silicate aqueous solution was obtained.

The resulting liquid was heated and aged at 98 ° C. for 30 minutes. Thereafter, 1,162 g of a silicic acid solution having the same composition as that of the silicic acid solution was added to this solution over a period of 4 hours, and a non-spherical silica sol having a pH of 8.9 was obtained. This non-spherical silica sol had a SiO ₂ / Na ₂ O molar ratio of 76.

After adding 2.5% sulfuric acid aqueous solution so that the pH of this non-spherical silica sol becomes 8.5 and heating at 90 ° C. for 8 hours, the non-spherical silica sol is concentrated by an evaporator to a SiO ₂ concentration of 20% by weight. Prepared.

The average particle size calculated from the specific surface area measured by the BET method for the non-spherical silica fine particles contained in the non-spherical silica sol was 12 nm, and the average particle size by the dynamic light scattering method was 34 nm. Further, the minor diameter / major diameter ratio of the non-spherical silica fine particles was 0.45, and the specific surface area was 220 m ² / g.
[Synthesis Example 2]

About 100 g of silica sol (manufactured by Catalyst Kasei Kogyo Co., Ltd .: Cataloid S-30L, average particle diameter measured by BET method: 15 nm, specific surface area: 182 m ² / g, SiO ₂ concentration: 30 wt%), the pH is 2. Until 3, the liquid was repeatedly passed through 0.4 L of strongly acidic cation exchange resin SK1BH (manufactured by Mitsubishi Chemical Corporation) at a space velocity of 3.1. Next, a strong basic ion exchange resin SANUPC (manufactured by Mitsubishi Chemical Corporation) was passed through 0.4 L at a space velocity of 3.1 to adjust the pH to 5.6, and then an alkaline aqueous solution so that the pH became 7.8. As a result, 5.4 g of a 5% aqueous ammonia solution was added. And it heated at 90 degreeC for 30 hours. This non-spherical silica sol was concentrated to an SiO ₂ concentration of 20% by weight with an evaporator to prepare a non-spherical silica sol.

The average particle size of this non-spherical silica sol measured by the BET method was 15 nm, and the average particle size by the dynamic light scattering method was 42 nm. Further, the non-spherical silica sol had a minor axis / major axis ratio of 0.4 and a specific surface area of 180 m ² / g.
[Synthesis Example 3]

A sodium silicate aqueous solution (SiO ₂ / Na ₂ O molar ratio: 3.1) having a SiO ₂ concentration of 24% by weight was diluted with ion-exchanged water to obtain a sodium silicate aqueous solution (pH 11) having a SiO ₂ concentration of 5% by weight.
. 3 kg of 3) 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 thoroughly washed with an Oliver filter with a 28% aqueous ammonia solution (corresponding 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 weight) to prepare a silica hydrogel dispersion in a fluid slurry state with a strong stirrer. This was added to a 5% by weight NaOH aqueous solution and 28% ammonia. A 1: 1 mixture of water was added to a SiO ₂ / Na ₂ O molar ratio of 75 and heated at 160 ° C. for 1 hour.

  Next, 0.81 kg of 24% sodium silicate and 10.93 kg of pure water were added to 2.09 kg of the non-spherical silica sol to prepare 13.83 kg (pH 11.2) of 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 90 ° C., 117.2 kg of a silicic acid solution having a SiO ₂ concentration of 4.5% by weight described later was added thereto over 10 hours. After completion of the addition, the mixture was cooled to room temperature, and the obtained non-spherical silica sol was concentrated to an SiO ₂ concentration of 20% by weight using an ultrafiltration membrane.

The average particle size of this non-spherical silica sol measured by the BET method was 50 nm, and the average particle size by the dynamic light scattering method was 150 nm. Further, the non-spherical silica sol had a minor axis / major axis ratio of 0.3 and a specific surface area of 50 m ² / g.
[Synthesis Example 4]

18.7 g of a sodium silicate aqueous solution (SiO ₂ / Na ₂ O molar ratio 3) having a SiO ₂ concentration of 24% by weight and a Na ₂ O concentration of 8.16% by weight is placed in a separable flask equipped with a reflux condenser and a stirrer, and water 895g was added and 914g of sodium silicate aqueous solution was prepared.

Next, this aqueous solution of sodium silicate was mixed with sodium silicate having a SiO ₂ concentration of 4.82% by weight (
A silicic acid solution having a SiO ₂ concentration of 4.82% by weight (pH 2.3, SiO ₂ / Na ₂ O molar ratio = 1) obtained by passing SiO ₂ / Na ₂ O molar ratio 3) through a cation exchange resin tower. 200) to 3
By adding 1,900 g under a temperature condition of 5 ° C., a mixed solution (SiO ₂ / Na ₂ O molar ratio 60) composed of a silicic acid solution and a sodium silicate aqueous solution was obtained.

The resulting mixture was warmed and aged at 80 ° C. for 30 minutes. While maintaining the temperature at 80 ° C., 329 g of a silicic acid solution having the same composition as that of the silicic acid solution was added to this solution over 2 hours to obtain a non-spherical silica sol having a pH of 8.7. This non-spherical silica sol had a SiO ₂ / Na ₂ O molar ratio of 76.

After heating this non-spherical silica sol at 70 ° C. for 12 hours, SiO _{2 was} evaporated with an evaporator.
Concentrated to a concentration of 20% by weight.
The average particle diameter of this non-spherical silica sol converted from the specific surface area measured by the BET method was 6 nm, and the average particle diameter by the dynamic light scattering method was 18 nm. Further, the value of the ratio of minor axis / major axis was 0.15, and the specific surface area was 455 m ² / g.

Pure water was added to the non-spherical silica sol prepared by the method of Synthesis Example 1 (average particle diameter by dynamic light scattering method: 34 nm, minor axis / major axis ratio: 0.45, specific surface area: 220 m ² / g) to obtain a silica concentration of 15.
Adjusted to 4 wt%.

850 g of a 0.9 wt% aqueous solution of sodium aluminate [chemical formula: NaAlO ₂ ] at 12 ° C. was added to 6500 g of this non-spherical silica sol (0.77% sodium aluminate with respect to 100 parts by mass of silica content of the non-spherical silica sol). (Corresponding to parts by mass) was continuously added uniformly 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 non-spherical silica fine particles) of the obtained dispersion of alumina-coated non-spherical silica fine particles was measured by the solid content measurement method of [6], and found to be 13.7% by weight. Pure water was added to 1199 g of this alumina-coated non-spherical silica fine particle 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 5586 g of this alumina-coated non-spherical silica fine particle aqueous solution (corresponding to 4.0 parts by mass of silica with respect to 100 parts by mass of alumina-coated non-spherical silica fine particles). Then, the temperature was raised to 98 ° C., followed by aging for 30 minutes, and 4305 g of a silica solution having a silica concentration of 3% by weight (silica solution silica with respect to 100 parts by mass of silica in the alumina-coated non-spherical silica fine particle aqueous solution after completion of the aging). (Corresponding to 75.6 parts by mass) was gradually and continuously 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 non-spherical alumina-silica composite sol and the production conditions of the non-spherical alumina-silica composite sol are shown in Tables 1 to 5.

  A scanning electron micrograph (magnification: 250,000 times) of the obtained non-spherical alumina-silica composite sol is shown in FIG. In addition, Table 5 shows the evaluation results of this non-spherical alumina-silica composite sol according to the above-described [9] Evaluation method of polishing characteristics for aluminum substrate. (Hereinafter, the evaluation results for Examples 2, 4, 5 and Comparative Examples 1 and 3 by the method for evaluating the polishing properties for the aluminum substrate are also shown in Table 5.)

Pure water was added to the non-spherical silica sol prepared by the method of Synthesis Example 2 (average particle diameter 42 nm by dynamic light scattering method, minor diameter / major diameter ratio 0.4, specific surface area 180 m ² / g) to obtain a silica concentration of 15. 4
Adjusted to wt%.

482 g of 0.9 wt% aqueous solution of sodium aluminate [chemical formula: NaAlO ₂ ] at 14 ° C. in 6500 g of this non-spherical silica sol (0.43 mass of sodium aluminate with respect to 100 mass parts of silica content of the non-spherical silica sol) Was added continuously over a period of 2 hours with stirring. And it heated up to 90 degreeC and age | cure | ripened for 3 hours.

  The content of solid content (alumina-coated non-spherical silica fine particles) of the obtained dispersion liquid of alumina-coated non-spherical silica fine particles was measured by the solid content measurement method of [6] and found to be 14.4% by weight. Pure water was added to 1463 g of this alumina-coated non-spherical silica fine particle aqueous solution to prepare a concentration of 2.7% by weight.

41 g (corresponding to 3.7 parts by mass of silica with respect to 100 parts by mass of alumina-coated non-spherical silica fine particles) is added to 7163 g of this aqueous solution of alumina-coated non-spherical silica fine particles. Then, the temperature was raised to 98 ° C., followed by aging for 30 minutes, and 2641 g of silica solution having a silica concentration of 3% by weight (silica solution silica with respect to 100 parts by mass of the silica content of the alumina-coated non-spherical silica fine particle aqueous solution after completion of the aging). The amount corresponding to 32.4 parts by mass) was gradually and continuously 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. The characteristics of the obtained non-spherical alumina-silica composite sol and the production conditions of the non-spherical alumina-silica composite sol are shown in Tables 1 to 5.

Pure water is added to the non-spherical silica sol prepared by the method of Synthesis Example 3 (average particle diameter 150 nm by dynamic light scattering method, minor diameter / major diameter ratio 0.3, specific surface area 50 m ² / g) to obtain a silica concentration of 15. 4
Adjusted to wt%.

1488 g of 0.9 wt% aqueous solution of sodium aluminate [chemical formula: NaAlO ₂ ] was added to 6500 g of this non-spherical silica sol at 25 ° C. (Corresponding to parts by mass) was continuously added uniformly over 6 hours with stirring. And it heated up to 90 degreeC and age | cure | ripened for 3 hours.

  The content of solid content (alumina-coated non-spherical silica fine particles) of the obtained dispersion liquid of alumina-coated non-spherical silica fine particles was measured by the solid content measurement method of [6] and found to be 12.7% by weight. Pure water was added to 882 g of this alumina-coated non-spherical silica fine particle aqueous solution to prepare a concentration of 2.8% by weight.

  48 g (corresponding to 10.1 parts by mass with respect to 100 parts by mass of the alumina-coated non-spherical silica fine particles) was added to 4704 g of this alumina-coated non-spherical silica fine particle aqueous solution (4704 g), After raising the temperature to 87 ° C. and aging for 30 minutes, maintaining the temperature at 87 ° C., 5961 g of silica solution with a silica concentration of 3% by weight (to 100 parts by mass of silica in the alumina-coated non-spherical silica fine particle aqueous solution after completion of the aging) On the other hand, the silica content of the silicic acid solution corresponds to 150 parts by mass) was gradually and continuously added over 7 hours with stirring. 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 non-spherical alumina-silica composite sol and the production conditions of the non-spherical alumina-silica composite sol are shown in Tables 1 to 5.

  Table 5 shows the results of evaluating the polishing characteristics of the obtained non-spherical alumina-silica composite sol by the above-mentioned [10] Evaluation method of polishing characteristics on glass substrate. (Hereinafter, for Comparative Examples 2 and 4, the evaluation results by the method for evaluating the polishing properties for [10] glass substrate are also shown in Table 5.)

Pure water was added to the non-spherical silica sol prepared by the method of Synthesis Example 1 (average particle diameter by dynamic light scattering method: 34 nm, minor axis / major axis ratio: 0.45, specific surface area: 220 m ² / g) to obtain a silica concentration of 15.
Adjusted to 4 wt%.

142 g of a 0.9 wt% aqueous solution of sodium aluminate [chemical formula: NaAlO ₂ ] at 25 ° C. in 6500 g of this non-spherical silica sol (0.13 mass of sodium aluminate with respect to 100 parts by mass of silica content of the non-spherical silica sol) Was added continuously and uniformly over 30 minutes with stirring. And it heated up to 90 degreeC and age | cure | ripened for 3 hours.

  The content of solid content (alumina-coated non-spherical silica fine particles) of the obtained dispersion liquid of alumina-coated non-spherical silica fine particles was measured by the solid content measurement method of [6] and found to be 15.1% by weight. Pure water was added to 1199 g of this alumina-coated non-spherical silica fine particle aqueous solution to prepare a concentration of 2.9% by weight.

  27 g (corresponding to 4.0 parts by mass with respect to 100 parts by mass of alumina-coated non-spherical silica fine particles) of No. 3 water glass (silica concentration: 24% by weight) was added to 6243 g of this aqueous solution of alumina-coated non-spherical silica fine particles, After raising the temperature to 98 ° C. and aging for 30 minutes, while maintaining the temperature at 98 ° C., 4305 g of silica solution with a silica concentration of 3% by weight (to 100 parts by mass of silica in the alumina-coated non-spherical silica fine particle aqueous solution after completion of the aging) On the other hand, the silica content of the silicic acid solution was equivalent to 75.6 parts by mass) and gradually added continuously 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 non-spherical alumina-silica composite sol and the production conditions of the non-spherical alumina-silica composite sol are shown in Tables 1 to 5.

Pure water was added to the non-spherical silica sol prepared by the method of Synthesis Example 4 (average particle diameter 18 nm by dynamic light scattering method, minor diameter / major diameter ratio 0.15, specific surface area 455 m ² / g) to obtain a silica concentration of 15.
Adjusted to 4 wt%.

To 25,000 ° C., 60.9 g of this non-spherical silica sol was 1983 g of a 0.9 wt% aqueous solution of sodium aluminate [chemical formula: NaAlO ₂ ] (sodium aluminate was 1.79 with respect to 100 parts by mass of silica content of the non-spherical silica sol. (Corresponding to part by mass) was continuously added uniformly 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 non-spherical silica fine particles) of the obtained dispersion of alumina-coated non-spherical silica fine particles was measured by the solid content measurement method of [6], and found to be 12.0% by weight. Pure water was added to 1199 g of this alumina-coated non-spherical silica fine particle aqueous solution to prepare a concentration of 2.9% by weight.

  To 4552 g of this alumina-coated non-spherical silica fine particle aqueous solution, 22 g of No. 3 water glass (silica concentration 24 wt%) was added (corresponding to 6.0 parts by mass with respect to 100 parts by mass of alumina-coated non-spherical silica fine particles), After raising the temperature to 98 ° C. and aging for 30 minutes, while maintaining the temperature at 98 ° C., 4343 g of a silica solution having a silica concentration of 3% by weight (to 100 parts by mass of silica in the alumina-coated non-spherical silica fine particle aqueous solution after completion of the aging) On the other hand, the silica content of the silicic acid solution was equivalent to 75.6 parts by mass) and gradually added continuously 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 conductivity of the aqueous solution becomes constant, and then the silica concentration is 12% by weight.
The solution was concentrated to 30%, and then concentrated to 30% using a rotary evaporator. The characteristics of the obtained non-spherical alumina-silica composite sol and the production conditions of the non-spherical alumina-silica composite sol are shown in Tables 1 to 5.
[Comparative Example 1]

Pure water was added to the non-spherical silica sol prepared by the method of Synthesis Example 1 (average particle diameter by dynamic light scattering method: 34 nm, minor axis / major axis ratio: 0.45, specific surface area: 220 m ² / g), and the silica concentration was 2. 8
Adjusted to wt%.

  To 5761 g of this non-spherical silica sol, 40 g of No. 3 water glass (silica concentration 24% by weight) was added to 6.0 parts by mass of silica in No. 3 water glass with respect to 100 parts by mass of non-spherical silica fine particles in the non-spherical silica sol. The mixture was heated to 98 ° C. and aged for 30 minutes. While maintaining the temperature at 98 ° C., 4199 g of a silica solution having a silica concentration of 3% by weight (to 100 parts by mass of the nonspherical silica fine particles in the nonspherical silica sol) On the other hand, the silica content of the silicic acid solution was equivalent to 75.6 parts by mass) and gradually added continuously 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 non-spherical silica sol and the production conditions thereof are shown in Tables 1 to 5.
[Comparative Example 2]

Pure water is added to the non-spherical silica sol prepared by the method of Synthesis Example 3 (average particle diameter 150 nm by dynamic light scattering method, minor diameter / major diameter ratio 0.3, specific surface area 50 m ² / g) to obtain a silica concentration of 2. Adjusted to 8 wt%.

  To 3972 g of this non-spherical silica sol, 46 g of No. 3 water glass (silica concentration 24% by weight) was added to 10.1 parts by mass of silica content of No. 3 water glass with respect to 100 parts by mass of non-spherical silica fine particles in the non-spherical silica sol. The mixture was heated to 98 ° C. and then 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 (100 parts by mass of non-spherical silica fine particles in the non-spherical silica sol) On the other hand, the silica content of the silicic acid solution corresponds to 150 parts by mass) was gradually added over 7 hours with stirring. 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 non-spherical silica sol and the production conditions thereof are shown in Tables 1 to 5. Table 5 shows the results of evaluating the polishing characteristics of the obtained non-spherical alumina-silica composite sol by the above-mentioned [10] Evaluation method of polishing characteristics on glass substrate.
[Comparative Example 3]

Pure water was added to the non-spherical silica sol prepared by the method of Synthesis Example 1 (average particle diameter by dynamic light scattering method: 34 nm, minor axis / major axis ratio: 0.45, specific surface area: 220 m ² / g), and the silica concentration was 2. 8
Adjusted to wt%. 2833 g of 0.9 wt% aqueous solution of sodium aluminate [chemical formula: NaAlO ₂ ] was added to 6500 g of this non-spherical silica sol at 2.5 ° C. (Corresponding to part by mass) was continuously added uniformly over 12 hours with stirring. And it heated up to 90 degreeC and age | cure | ripened for 3 hours.

When the content of solid content (alumina-coated non-spherical silica fine particles) of the obtained dispersion liquid of alumina-coated non-spherical silica fine particles was measured by the solid content measurement method of [6], it was 11.0% by weight. Pure water was added to 1494 g of this alumina-coated non-spherical silica fine particle aqueous solution to prepare a concentration of 2.9% by weight.

  41 g (corresponding to 6.0 parts by mass with respect to 100 parts by mass of the alumina-coated non-spherical silica fine particles) was added to 8483 g of this alumina-coated non-spherical silica fine particle aqueous solution (8383 g). The temperature was raised to 98 ° C. and then aged for 30 minutes. While maintaining the temperature at 98 ° C., 4190 g of a silica solution having a silica concentration of 3% by weight (to 100 parts by mass of silica in the alumina-coated non-spherical silica fine particle aqueous solution after completion of the aging) On the other hand, the silica content of the silicic acid solution was equivalent to 75.6 parts by mass) and gradually added continuously 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 non-spherical alumina-silica composite sol sol and the production conditions thereof are shown in Tables 1 to 5. [Comparative Example 4]

  Spherical silica sol (Cataloid SI-80 manufactured by Catalytic Chemical Industry Co., Ltd. (average particle diameter 110 nm by dynamic light scattering method) was adjusted to a silica concentration of 20% by mass and polished by the above-mentioned [10] Evaluation method of polishing characteristics for glass substrate. The results of evaluating the characteristics are shown in Table 5.

The alumina-silica composite sol of the present invention is useful as an abrasive and a polishing composition. The aluminum disk (aluminum or a plating layer on the substrate thereof), aluminum wiring of a semiconductor multilayer wiring board, glass for optical disks and magnetic disks. It can be used for substrates, glass substrates for liquid crystal displays, glass substrates for photomasks, 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, coagulation promoters, suspending agents, thickeners, soil hardeners, and the like.

Schematic diagram of how to find the maximum value Schematic of how to find the coefficient of variation of distance Y Scanning electron micrograph of the non-spherical alumina-silica composite sol prepared in Example 1 (magnification: 250,000 times)

Claims (7)

The average particle diameter measured by the dynamic light scattering method is in the range of 3 to 150 nm, the short diameter / long diameter ratio is in the range of 0.01 to 0.8, the specific surface area is in the range of 10 to 800 m ² / g, and the surface A non-spherical alumina-silica composite sol, wherein non-spherical alumina-silica composite fine particles having a plurality of hook-shaped protrusions are dispersed in a dispersion medium. On the plane containing the long axis of the non-spherical alumina-silica composite fine particles,
The distance from an arbitrary point on the outer edge of the non-spherical alumina-silica composite fine particle to the intersection B of the straight line passing through the point on the outer edge and perpendicular to the long axis is Y, and the non-spherical alumina- When an XY curve is drawn with a distance from one intersection A between the outer edge of the silica composite fine particle and the major axis to the intersection B as X, the XY curve has a plurality of maximum values. The non-spherical alumina-silica composite sol according to claim 1.   On a plane including the long axis of the non-spherical alumina-silica composite fine particle, from any point on the outer edge of the non-spherical alumina-silica composite fine particle, a straight line passing through the point on the outer edge and orthogonal to the long axis; The non-spherical alumina-silica according to claim 1 or 2, wherein when the distance to the intersection B with the long axis is Y, the variation coefficient of the distance Y is in the range of 5 to 50%. Composite sol.   Nonspherical particles in which nonspherical silica fine particles having an average particle diameter measured by a dynamic light scattering method in the range of 3 to 150 nm and a minor axis / major axis ratio in the range of 0.01 to 0.8 are dispersed in a dispersion medium. Alumina-coated non-spherical silica fine 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 non-spherical silica fine particles and then aging the silica sol. Next, an alkali metal silicate corresponding to 0.1 to 100 parts by mass is added to 100 parts by mass of the alumina-coated non-spherical silica fine particles, and after aging, the silicic acid solution is continuously added. 4. The production of a non-spherical alumina-silica composite sol according to any one of claims 1, 2 and 3, wherein particles are grown to form protrusions by being added intermittently or intermittently. Direction .     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 non-spherical silica fine particles, and the addition of the silicic acid solution is continuously performed over 2 to 24 hours. 5. The method for producing a non-spherical alumina-silica composite sol according to claim 4, wherein the method is carried out intermittently.   An abrasive comprising the non-spherical alumina-silica composite sol according to claim 1, claim 2 or claim 3.   A polishing composition comprising the non-spherical alumina-silica composite sol according to claim 1, claim 2 or claim 3.