JP5532199B2 - Colloidal solution of metal compound and method for producing the same - Google Patents

Description

  The present invention relates to a colloidal solution of a metal compound and a method for producing the same.

  Metal compounds such as metal oxides and metal salts are used in various applications such as catalysts. In recent years, such metal compounds have been made nanosized in order to fully exhibit their functions or to exhibit functions not found in bulk bodies.

  For example, Japanese Patent Application Laid-Open No. 2008-19106 (Patent Document 1) discloses a metal having a primary particle size of nanometer order by adding a water-soluble amine to an aqueous solution containing metal ions and adjusting the pH of the aqueous solution to 4 or more. A method for producing oxide particles is disclosed. Furthermore, it is also disclosed that metal oxide particles can be highly dispersed in water by making the polymer protective agent coexist.

However, after adding diethanolamine and polyethylene glycol to an aqueous solution containing cerium ions, zirconium ions and yttrium ions, the resulting solution is adjusted to pH 3 by adding nitric acid, and further subjected to ultrasonic treatment. The particle size of the agglomerates was as large as submicron order, and the storage stability of the colloidal solution was not sufficient.
JP 2008-19106 A

  The present invention has been made in view of the above-mentioned problems of the prior art. The crystallites of a metal compound having a small diameter and uniform are dispersed in a state of a uniform aggregate having a small diameter and excellent in storage stability. It is an object to provide a colloidal solution of a metal compound and a method for producing the same.

  As a result of intensive studies to achieve the above object, the inventors of the present invention obtained two or more kinds of raw material solutions containing a metal ion and a polymer dispersant, which are raw materials for metal compounds, at a predetermined high shear rate. Introduced directly into the region, and mixed homogeneously. Furthermore, by destroying the agglomerates of metal compound crystallites and simultaneously adsorbing the polymer dispersant to a single crystallite, the crystals of metal compounds with small diameters are uniform. The inventors have found that a colloidal solution in which a child is dispersed in a state of uniform aggregates having a small diameter can be obtained, and the present invention has been completed.

That is, the colloidal solution of the metal compound of the present invention is a colloidal solution of a metal compound produced by mixing two or more raw material solutions,
At least one of the two or more raw material solutions contains a metal ion that is a raw material of the metal compound, and at least one of the two or more raw material solutions is (meth) acrylic acid. A homopolymer of (meth) acrylic acid and a copolymer of (meth) acrylic acid ester, and at least one selected from the group consisting of sodium salts and ammonium salts thereof having a weight average molecular weight of 800 to 3000 It contains a (meth) acrylic acid polymer,
Arranged so that a predetermined gap region is formed between the rotor and the outer stator arranged to form a predetermined gap region between the rotor and the inner periphery of the rotor. Using a homogenizer with an inner stator
Each of the raw material solutions is directly and independently introduced into a region formed by rotating the rotor and having a shear rate of 3000 sec ⁻¹ or more, and obtained by homogeneous mixing.
Cumulative number 50 percent becomes the crystallite size d ₅₀ is 0.8~3nm and crystallite diameter d ₉₀ is the crystallite size of which cumulative number of 90% at a measuring particle size distribution by transmission electron microscopy and aggregates of crystallites of the metal compound is 1.5 times the d _50, containing said as the polymer dispersant (meth) acrylic acid polymer, wherein the agglomerates, by dynamic light scattering method agglomerated particle size _{D 90} of and cumulative mass is the aggregated particle diameter _{D 50} which cumulative mass is 50% 4~9nm in measured particle size distribution is 90% or less 2.5 times the aggregate particle diameter _{D 50} are those of the (meth) 9~15mg / ^{m 2} der respect to the unit surface area of the crystallite of the content of the acrylic polymer is the metal compound Ri, pH is at 5.0 to 10.0 It is characterized by that.

In such a metal compound colloidal solution, at least one of the two or more raw material solutions contains the metal ion, and at least one of the remaining raw material solutions contains the (meta) It is preferable to contain an acrylic acid polymer, and the raw material solution containing the metal ion is a solution containing a metal salt that is a raw material of the metal compound, and the (meth) acrylic acid polymer is More preferably, the raw material solution to be contained further contains a neutralizing agent. Moreover, it is preferable that the cation density | concentration of the raw material solution containing the said metal ion is 0.01-0.5 mol / L.

The method for producing a colloidal solution of a metal compound of the present invention is a method for producing a colloidal solution of a metal compound by mixing two or more kinds of raw material solutions, wherein at least one of the two or more kinds of raw material solutions is It contains a metal ion that is a raw material of the metal compound, and at least one of the two or more raw material solutions is a homopolymer of (meth) acrylic acid, (meth) acrylic acid and (meth) It contains a copolymer with an acrylate ester, and a (meth) acrylic acid polymer having a weight average molecular weight of 800 to 3000 selected from the group consisting of sodium salts and ammonium salts thereof . A rotor and an outer stator disposed so that a predetermined gap region is formed between the outer periphery of the rotor and an inner periphery of the rotor. Using a homogenizer and a arranged inside stator as regions of constant gap is formed, the rotor 3000 sec ^-1 or more, which is formed by rotating the (preferably 6000Sec ^-1 or higher) a shear rate of In each region, each raw material solution is independently adjusted so that the content of the (meth) acrylic acid polymer in the colloidal solution is 9 to 15 mg / m ² with respect to the unit surface area of the crystallite of the metal compound. It is a method characterized by adjusting the pH of the resulting colloidal solution to 5.0-10.0 by introducing it directly into the mixture and mixing homogeneously.

In such a method for producing a colloidal solution, one containing the metal ions is used as at least one of the two or more kinds of raw material solutions, and the above (meta) is used as at least one of the remaining raw material solutions. It is preferable to use a material containing an acrylic acid polymer, and the raw material solution containing the metal ion is a solution containing a metal salt that is a raw material of the metal compound, and the (meth) acrylic acid heavy polymer It is more preferable that the raw material solution containing the coalescence further contains a neutralizing agent. Moreover, it is preferable that the cation density | concentration of the raw material solution containing the said metal ion is 0.01-0.5 mol / L.

Colloidal solution odor of the metal compound of the present invention Te, the (meth) acrylic acid-based polymer, when the pH of the colloidal solution is lower than 5.0 or 7.0, the hydrophilic groups of the total repeating units The ratio of those having 90 to 100% is preferable. When the pH of the colloidal solution is 7.0 to 10.0, the ratio of the repeating unit having the hydrophilic group is 50% to 100%. Is preferred. In the method for producing a colloidal solution of a metal compound of the present invention, when the ratio of those having a hydrophilic group among all repeating units in the (meth) acrylic acid polymer is 90% or more and 100% or less. Adjusts the pH of the colloidal solution to 5.0 or more and 10.0 or less, and when the ratio of the repeating unit having the hydrophilic group is 50% or more and less than 90%, the pH of the colloidal solution is 7.0 or more and 10. It is preferable to adjust to 0 or less.

  The reason why the colloidal solution in which the crystallite of the metal compound having a small diameter and uniform is dispersed in the state of a uniform aggregate having a small diameter is obtained by the production method of the present invention is not necessarily clear. Guesses as follows. That is, nanoparticles such as metal compound crystallites are likely to aggregate in an aqueous solution such as water. Usually, a dispersant is added and adsorbed on the nanoparticles to suppress aggregation. It is surmised that the polymer dispersant used in the present invention is also adsorbed to the nanoparticles and suppresses aggregation, but an aggregate having a large particle diameter is formed only by adding the polymer dispersant and performing normal stirring. Tend to form. This is because the polymer dispersant is usually larger than the primary particles and tends to form a crosslinked structure, so that the nanoparticles adsorbed by the polymer dispersant agglomerate with the crosslinking reaction of the polymer dispersant, This is presumably because the polymer dispersant is adsorbed simultaneously on a plurality of metal compound crystallites.

  Further, when diethanolamine and polyethylene glycol are added, aggregates having a large particle size tend to be formed. This is because the diethanolamine added to produce the metal compound is adsorbed on the produced metal compound particles and inhibits the adsorption of polyethylene glycol, so that the aggregation suppressing effect by polyethylene glycol is not sufficiently exhibited. It is presumed that sufficient steric hindrance repulsion does not act even when adsorbed on the metal compound particles, and the aggregation suppressing effect by diethanolamine is not sufficiently exhibited. Further, since the adsorption amount of polyethylene glycol is small and the repulsive action is small, it is presumed that the aggregate further aggregates during storage of the colloidal solution and the dispersibility is lowered.

  On the other hand, in the production method of the present invention, since a high shear force is imparted to the reaction field in addition to the addition of the polymer dispersant, the aggregate structure of the metal compound crystallites is destroyed and at the same time the polymer dispersant Is adsorbed on the crystallites, and the aggregates are presumed to exist in the colloidal solution in a relatively small particle size. Further, since the polymer dispersant is stably present in the colloidal solution, it is assumed that the small aggregates are not further aggregated and are stably dispersed in the colloidal solution.

  According to the present invention, it is possible to obtain a metal compound colloidal solution in which a uniform crystallite of a metal compound having a small diameter is dispersed in a state of a uniform aggregate having a small diameter and excellent in storage stability.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof.

First, the colloidal solution of the metal compound of the present invention will be described. Colloidal solution of metal compounds of the present invention, the crystallite diameter d ₉₀ is the crystallites and the cumulative number is a crystallite size d ₅₀ of 0.8~3nm cumulative number becomes 50% is 90% in the particle size distribution An aggregated particle diameter D ₅₀ containing a crystallite aggregate of a metal compound having a diameter d ₅₀ or less of a diameter d ₅₀ and a polymer dispersant, wherein the aggregate has a cumulative mass in a particle size distribution of 50%. The aggregate particle diameter D ₉₀ at which the cumulative mass is 90% and the cumulative mass is 90% is not more than 2.5 times the aggregate particle diameter D ₅₀ .

In the present invention, the particle size distribution of the metal compound crystallites can be determined by, for example, extracting 50 metal compound crystallites and directly measuring the crystallite diameter in a transmission electron microscope observation of the metal compound. Crystallites of the metal compound contained in the colloidal solution of the present invention thus crystallite size d ₅₀ of the cumulative number of 50% in the measured particle size distribution is 0.8～3Nm (preferably 1.0 to And the crystallite diameter d ₉₀ at which the cumulative number becomes 90% is 1.5 times or less (preferably 1.3 times or less) of the crystallite diameter d ₅₀ . The metal compound crystallites having such crystallite diameters d ₅₀ and d ₉₀ have a large specific surface area and are useful as a starting material for a highly active and highly durable catalyst, for example.

In the colloidal solution of the present invention, such metal compound crystallites are present in an aggregated state. The particle size distribution of the aggregates of metal compound crystallites in the colloidal solution can be measured by, for example, a dynamic light scattering method. Aggregates of the metal compound crystallites contained in the colloidal solution of the present invention, aggregated particle diameter D ₅₀ which cumulative mass in measured particle size distribution in this way is 50 percent 4～70Nm (preferably 4～30Nm, More preferably, the aggregated particle diameter D ₉₀ with a cumulative mass of 90% is not more than 2.5 times (preferably not more than 2.0 times) the aggregated particle diameter D ₅₀ . Aggregates having such aggregated particle diameters D ₅₀ and D ₉₀ become crystallites having a size corresponding to the aggregated particle diameter by heat treatment. This crystallite is useful as a catalyst carrier having an excellent balance between specific surface area and heat resistance. In addition, when the aggregate is adsorbed on particles having an alumina skeleton, the pore size distribution of the aggregate can be arbitrarily controlled by changing the pore diameter of the particles having the alumina skeleton. Therefore, by using the colloidal solution of the metal compound of the present invention in the preparation of the catalyst carrier, it becomes possible to design an ideally shaped catalyst carrier according to the operating temperature range of the catalyst. It is possible to obtain a highly heat-resistant catalyst having an optimum pore diameter and having an ideal catalytic activity in the diffusion-controlled region.

  The metal contained in the metal compound according to the present invention is not particularly limited, but Ti, Zr, Al, Si, rare earth metals (La, Ce, Pr, Y, Sc, etc.), alkaline earth metals (Sr, Ca, Ba, etc.), Fe, Co, Ni, Cu, Zn, Rh, Ag, Pt, Pd, Au, V, Mn and the like. These metals may be used individually by 1 type, or may use 2 or more types together. Among these, Zr, Ce, Y, Al, and La are preferable from the viewpoint of having oxygen storage ability and heat resistance.

Further, the metal compound according to the present invention is not particularly limited, and examples thereof include the metal oxides, hydroxides, salts, carbides, nitrides, sulfides, and intermediate products thereof. Examples of the metal oxide include an oxide containing one kind of the metal, a composite oxide containing two or more kinds of the metal, and a mixture of oxides containing one kind of the metal. Specific metal oxides include CeO ₂ , ZrO ₂ , Y ₂ O ₃ , TiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , composite oxides thereof, and mixtures thereof, among others, oxygen storage from the viewpoint of having a capability and heat resistance, composite oxide composed mainly of CeO ₂ or ZrO ₂ are _{preferable, CeO 2 -ZrO 2 -Y 2 O} 3 3 -element complex oxide are more preferred.

Examples of the metal hydroxide include hydroxides containing one or more of the metals, and mixtures thereof. Specific examples of the metal hydroxide include Ce (OH) ₄ , Zr (OH) ₄ , Al (OH) ₃ , Ti (OH) ₄ , and Fe (OH) ₂ . Furthermore, examples of the metal salt include sulfates, carbonates, oxalates, and phosphates. Specific examples of the metal salt include BaSO ₄ , CaCO ₃ , calcium oxalate, and titanium phosphate. The same applies to carbides, nitrides, sulfides and the like.

  The colloidal solution of the present invention contains a polymer dispersant. The presence of the polymer dispersant in the colloidal solution enables the crystallites of the metal compound to be stably dispersed in the colloidal solution in the state of an aggregate having the aggregated particle size and the particle size distribution. Become.

In the colloidal solution of the present invention, the content of the polymer dispersant is preferably 9 to 21 mg / m ^{2 and} more preferably 9 to 15 mg / m ² with respect to the unit surface area of the crystallite of the metal compound. When the content of the polymer dispersant is in the above range, the aggregate of the metal compound crystallites has a small particle size and is uniform, and a colloidal solution having excellent storage stability can be obtained. On the other hand, when the content of the polymer dispersant is less than the lower limit, the surface of the metal compound crystallite cannot be sufficiently covered with the polymer dispersant, and the crystallites aggregate to form larger aggregates. On the other hand, if the upper limit is exceeded, a large amount of free polymer dispersant is present in the colloidal solution, so that the crosslinking reaction of the polymer dispersant proceeds remarkably and larger aggregates tend to remain. is there.

  Although there is no restriction | limiting in particular as a weight average molecular weight of such a polymer dispersing agent, 800-8000 are preferable and 800-3000 are more preferable. When the weight average molecular weight of the polymer dispersant is within the above range, the aggregate of metal compound crystallites has a small particle size and becomes uniform, and a colloidal solution having excellent storage stability can be obtained. On the other hand, when the weight average molecular weight of the polymer dispersant is less than the lower limit, even if the polymer dispersant is adsorbed to the crystallite, the repulsive force due to steric hindrance or electrostatic repulsion is not sufficiently exhibited, and the crystallites tend to aggregate. On the other hand, when the upper limit is exceeded, the polymer dispersant becomes extremely larger than the crystallites, and larger aggregates tend to remain. The weight average molecular weight is a value measured by gel permeation chromatography (GPC) and converted to standard polystyrene.

  The polymer dispersant used in the present invention includes a homopolymer of (meth) acrylic acid, a copolymer of (meth) acrylic acid and (meth) acrylic acid ester, (meth) acrylic acid and other vinyl monomers (Meth) acrylic acid polymers such as copolymers, and (meth) acrylic acid polymers are preferred from the viewpoint of maintaining water solubility, and (meth) acrylic acid homopolymers. A copolymer of (meth) acrylic acid and (meth) acrylic acid ester is more preferred.

  Moreover, when a (meth) acrylic acid polymer is used as the polymer dispersant, the pH of the colloidal solution of the present invention is preferably 5.0 to 10.0, and 6.0 to 9.0. It is more preferable. When the pH of the colloidal solution is within the above range, the aggregate of metal compound crystallites has a small particle size and becomes uniform, and a colloidal solution having excellent storage stability can be obtained. On the other hand, since the carboxyl group in the (meth) acrylic acid polymer does not dissociate when the pH is less than the lower limit, the amount of adsorption of the (meth) acrylic acid polymer to the metal compound crystallite decreases, On the other hand, when the above upper limit is exceeded, depending on the type of the metal compound, the surface of the metal compound crystallite is likely to be negatively charged, and the (meth) acrylic acid-based heavy compound in which the carboxyl group has been dissociated. The adsorbed amount of coalescence decreases, and crystallites tend to aggregate further.

  The proportion of those having a hydrophilic group among all repeating units in the (meth) acrylic acid polymer is 90% or more when the pH of the resulting colloidal solution is 5.0 or more and less than 7.0. 100% or less is preferable. When the pH of the colloidal solution is 7.0 or more and 10.0 or less, the ratio of the repeating unit having a hydrophilic group is preferably 50% or more and 100% or less, and more preferably 75% or more and 100% or less. When the ratio of the repeating unit having a hydrophilic group is within the above range, the (meth) acrylic acid polymer is adsorbed to the metal compound crystallite in a loop train type, and therefore repulsive force due to steric hindrance acts to cause aggregation of the crystallites. Effectively suppressed, the agglomerates of metal compound crystallites have a small particle size and are uniform, and a colloidal solution having excellent storage stability can be obtained. On the other hand, when the ratio of the repeating unit having a hydrophilic group is less than the lower limit, the dissociated carboxyl group in the (meth) acrylic acid polymer is insufficient, and the (meth) acrylic acid polymer is adsorbed on the metal compound crystallite. The amount decreases and the crystallites tend to further aggregate.

  The solvent used in the present invention is preferably water. Accordingly, a colloidal aqueous solution is preferred as the colloidal solution of the present invention.

Such a colloidal solution of the metal compound of the present invention is, for example, a method of mixing two or more kinds of raw material solutions (preferably a raw material aqueous solution, the same shall apply hereinafter), using those containing the metal ions as at least one of which uses those containing the polymer dispersing agent as at least one of said two or more kinds of raw material solution, 3000 sec these raw solution ^- It can be produced by a method in which it is independently introduced directly into a region having a high shear rate of ¹ or more and homogeneously mixed. According to this method, it is possible to disperse the metal compound crystallites in a state of uniform aggregates with a small diameter even in water in which the metal compound crystallites easily aggregate.

  As an apparatus used for manufacturing such a colloidal solution of a metal compound, for example, the apparatus shown in FIG. Hereinafter, a preferred apparatus for producing a colloidal solution of a metal compound of the present invention will be described in detail with reference to the drawings. In the following description and drawings, the same or corresponding elements are denoted by the same reference numerals, and duplicate descriptions are omitted.

  The manufacturing apparatus shown in FIG. 1 includes a homogenizer 10 as a high-speed stirring device, and the tip (stirring portion) of the homogenizer 10 is disposed in the reaction vessel 20. As shown in FIG. 2, the front end of the homogenizer 10 includes a concave outer stator 12 disposed so that a predetermined gap region is formed between the concave rotor 11 and the outer periphery of the rotor 11, and the rotor. 11 and a convex inner stator 13 arranged so that a predetermined gap region is formed between the inner periphery of the inner stator 11 and the inner periphery. Furthermore, the rotor 11 is connected to a motor 15 via a rotating shaft 14 and has a structure capable of rotating at high speed.

  In the manufacturing apparatus shown in FIG. 1, a plurality of nozzles, that is, a nozzle 16 </ b> A for introducing the raw material solution A and a nozzle 16 </ b> B for introducing the raw material solution B are opposed to the rotor 11 in the inner stator 13. It is provided on each surface. Further, a supply device (not shown) for the raw material solution A is connected to the nozzle 16A via a flow path 17A, and a supply device (not shown) for the raw material solution B is connected to the nozzle 16B via a flow path 17B. The raw material solution A and the raw material solution B can be directly and independently introduced into the region between the rotor 11 and the inner stator 13.

  Further, in the manufacturing apparatus shown in FIG. 1, as shown in FIGS. 3 and 4, the nozzle 16 </ b> A and the nozzle 16 </ b> B are orthogonal to the rotation axis X of the rotor 11 on the surface facing the rotor 11 in the inner stator 13. The predetermined surfaces Y are alternately provided in the outer peripheral direction.

  3 and 4, 12 nozzles 16A and 12 nozzles 16B are provided (24-hole type), but the number of nozzles 16A and nozzles 16B is not particularly limited. Therefore, it is only necessary to provide one nozzle 16A and one nozzle 16B (two-hole type), but the time from when the raw material solution A and the raw material solution B are introduced into the region until homogeneous mixing is further reduced. From the viewpoint of being able to do so, the number of nozzles 16A and 16B is preferably 10 or more, and more preferably 20 or more. On the other hand, the upper limit of the number of each of the nozzles 16A and 16B is not particularly limited and varies depending on the size of the apparatus. From the viewpoint of more reliably preventing nozzle clogging, the alternately arranged nozzles 16A It is preferable that the diameter of the opening of the nozzle 16B can be about 0.1 mm or more. As described above, the diameter of the opening of the nozzle is not particularly limited and varies depending on the size of the apparatus, but is preferably about 0.1 to 1 mm from the viewpoint of more reliably preventing nozzle clogging. .

  3 and 4, the nozzles 16A and the nozzles 16B are alternately provided in a row in the outer circumferential direction of one surface Y orthogonal to the rotation axis X of the rotor 11. It may be provided alternately in a plurality of rows in the outer circumferential direction.

In the manufacturing apparatus shown in FIG. 1 described above, regions where the raw material solution A and the raw material solution B are respectively introduced from the nozzle 16A and the nozzle 16B, that is, the inner periphery of the rotor 11 and the inner stator 13 in FIGS. in the region between the outer periphery of, preferably shear rate is 3000 sec ^-1 or more, and particularly preferably 6000Sec ^-1 or more. When the shear rate in this region is less than the lower limit, the aggregation of the metal compound crystallites and the structure in which the polymer dispersant is adsorbed on the plurality of crystallites are not destroyed, and larger aggregates tend to remain.

  The conditions for achieving such a high shear rate are affected by the rotational speed of the rotor and the size of the gap between the rotor and the stator. Must be set. The specific rotation speed of the rotor 11 is not particularly limited and varies depending on the size of the apparatus. For example, the outer diameter of the inner stator 13 is 12.2 mm, and the gap between the rotor 11 and the outer stator 12 is 0. In the case of 5 mm and a gap between the rotor 11 and the inner stator 13 of 0.5 mm, the rotational speed of the rotor 11 is preferably set to 3000 to 30000 rpm, more preferably 3000 to 20000 rpm, and the shear rate in the above range is set. Can be achieved.

  Further, the size of the gap between the rotor 11 and the inner stator 13 is not particularly limited and varies depending on the size of the device, but is preferably 0.2 to 1.0 mm, and preferably 0.2 to 0 mm. More preferably, it is 5 mm. Further, the size of the gap between the rotor 11 and the outer stator 12 is not particularly limited, and varies depending on the size of the device, but is preferably 0.2 to 1.0 mm, and preferably 0.2 to 0 mm. More preferably, it is 5 mm. By adjusting the rotational speed of the rotor 11 in response to the change in the size of the gap, it becomes possible to achieve the shear speed in the above range. When these gaps are less than the lower limit, clogging of the gaps tends to occur, and when the upper limit is exceeded, high shear rates tend not to be achieved.

  Further, in the manufacturing apparatus shown in FIG. 1, the raw material solution A and the raw material solution B respectively supplied from the nozzle 16A and the nozzle 16B are introduced within 1 msec (particularly preferably within 0.5 msec) after being introduced into the region. It is preferable that the nozzle 16A and the nozzle 16B are arranged so as to be homogeneously mixed. Here, the time from when the raw material solution is introduced into the region until it is homogeneously mixed is the time when the raw material solution A (or raw material solution B) introduced from the nozzle 16A (or nozzle 16B) rotates the rotor 11. It is a time until the position of the adjacent nozzle 16B (or nozzle 16A) is reached and mixed with the raw material solution B (or raw material solution A) introduced from the nozzle 16B (or nozzle 16A).

  As mentioned above, although the apparatus used for manufacture of the colloidal solution of this invention was demonstrated, the manufacturing method of the colloidal solution of this invention is not limited to the method using the manufacturing apparatus shown in FIG. For example, the manufacturing apparatus shown in FIG. 1 is configured so that two kinds of raw material solutions can be introduced, but a nozzle, a raw material solution supply apparatus, or the like may be configured so that three or more kinds of raw material solutions can be introduced. Good.

  Further, in the manufacturing apparatus shown in FIG. 1, the nozzle 16 </ b> A and the nozzle 16 </ b> B are respectively provided on the surface facing the rotor 11 in the inner stator 13, but the nozzle 16 </ b> A and the nozzle 16 </ b> B are respectively rotors in the outer stator 12. 11 may be provided respectively on the surface facing 11. If comprised in that way, it will become possible to introduce the raw material solution A and the raw material solution B directly into the area | region between the rotor 11 and the outer side stator 12, respectively independently. Note that the shear rate in that region needs to be set so as to satisfy the above condition.

  Next, a preferred embodiment of the method for producing a colloidal solution of the present invention will be described. In the method for producing a colloidal solution of the present invention, the shear rate of the region into which the raw material solution is introduced is set in the above range, and each of the raw material solutions is directly and independently introduced into the region. For example, when the manufacturing apparatus shown in FIG. 1 is used, regions where the raw material solution A and the raw material solution B are respectively introduced from the nozzle 16A and the nozzle 16B, that is, the rotor 11 and the inner stator 13 in FIG. 1 and FIG. The rotor 11 is rotated at a high speed so that the shear rate in the region between is within the above range, and the raw material solution A and the raw material solution B are directly introduced into the region independently from the nozzle 16A and the nozzle 16B, respectively. Thus, each raw material solution directly introduced into the region where the shear rate is extremely high is homogeneously mixed in a very short time to complete the reaction, and a crystallite of a metal compound is formed and remarkably aggregates. At the same time, the aggregate is instantaneously broken, and the polymer dispersant is effectively adsorbed on the crystallite surface. As a result, a colloidal solution in which crystallites are highly dispersed can be obtained.

  In the method for producing a colloidal solution of the present invention, the metal ions and the polymer dispersant may be contained in the same raw material solution, or may be contained in different raw material solutions. It is preferable that at least one of the plurality of raw material solutions contains the metal ion, and at least one of the remaining raw material solutions contains the polymer dispersant. For example, when the manufacturing apparatus shown in FIG. 1 is used, both the metal ions and the polymer dispersant may be contained in the raw material solution A, or the raw material solution A contains the metal ions. The polymer dispersant may be contained in B, but the latter is preferable.

  In the method for producing a colloidal solution of the present invention, the cation concentration of the raw material solution containing the metal ions (for example, the raw material solution A) is preferably 0.01 to 0.5 mol / L, preferably 0.05 to 0. More preferable is 1 mol / L. When the cation concentration is within the above range, the aggregate of metal compound crystallites has a small particle size and becomes uniform, and a colloidal solution having excellent storage stability can be obtained. On the other hand, when the cation concentration is less than the lower limit, the yield of the crystallites of the metal compound tends to decrease, whereas when the upper limit is exceeded, the distance between the particles of the metal compound crystallites in the colloidal solution is shortened. The polymer dispersant adsorbed on the crystallites tends to be adsorbed on many crystallites, and the crystallites and aggregates tend to further aggregate.

  When a (meth) acrylic acid polymer is used as a polymer dispersant in the method for producing a colloidal solution of the present invention, it is preferable to adjust the pH of the colloidal solution to 5.0 to 10.0. It is more preferable to adjust to 0-9.0. In particular, when the (meth) acrylic acid-based polymer having a hydrophilic group among all repeating units of 90% to 100% is used, the colloidal solution has a pH of 5.0 to 10. More preferably, it is adjusted to 0 or less. In addition, when the ratio of the repeating unit having a hydrophilic group is 50% or more and less than 90% (more preferably 75% or more and less than 90%), the pH of the colloidal solution is 7.0 or more and 10.0 or less. It is more preferable to adjust. By adjusting the pH of the colloidal solution to the above range, a uniform aggregate of metal compound crystallites having a small particle diameter can be obtained, and a colloidal solution excellent in storage stability can be obtained. On the other hand, since the carboxyl group in the (meth) acrylic acid polymer does not dissociate when the pH is less than the lower limit, the amount of adsorption of the (meth) acrylic acid polymer to the metal compound crystallite decreases, On the other hand, when the above upper limit is exceeded, depending on the type of the metal compound, the surface of the metal compound crystallite is likely to be negatively charged, and the (meth) acrylic acid-based heavy compound in which the carboxyl group has been dissociated. The adsorbed amount of coalescence decreases, and crystallites tend to aggregate further.

  The feed rate of each raw material solution is not particularly limited, but is preferably 10 to 30 ml / min. When the feed rate of the raw material solution is less than the lower limit, the production efficiency of the metal compound crystallites and aggregates thereof tends to decrease. Tend to be.

  The reaction system applicable to such a method for producing a colloidal solution of the present invention is not particularly limited, and examples thereof include a hydrolysis reaction of alkoxide and a precipitation reaction utilizing a change in solubility using a poor solvent. Even in a reaction with a very fast nucleation rate or reaction rate such as an oxidation-reduction reaction, the agglomerates of metal compound crystallites have a small particle size and become uniform according to the production method, and a colloidal solution having excellent storage stability can be obtained. Therefore, the production method of the present invention is particularly useful for such a reaction system having a very high nucleation rate and reaction rate.

  The specific reaction system in such neutralization reaction, oxidation-reduction reaction and the like is not particularly limited. For example, when two kinds of raw material solutions are used, the following reaction system can be mentioned.

(I) Neutralization reaction I
Raw material solution A (metal ion-containing solution): Solution raw material containing the metal acetate, fatty acid salt (eg, oxalate), and inorganic acid salt (eg, nitrate, sulfate, hydrochloride) that is the raw material of the metal compound Solution B (neutralizing agent): ammonia water, a solution containing an ammonium salt of a fatty acid (for example, oxalic acid) or an inorganic acid (for example, nitric acid, sulfuric acid, hydrochloric acid), or an alkali metal hydroxide solution (aqueous sodium hydroxide solution, water) Potassium oxide aqueous solution).

(Ii) Neutralization reaction II
Raw material solution A (alkaline raw material liquid): Solution raw material solution B (acidic raw material liquid) containing barium acetate, calcium chloride and the like: A solution containing ammonium sulfate, ammonium carbonate and the like.

(Iii) Redox reaction raw material solution A: Solution raw material solution B containing silver nitrate, chloroplatinic acid, etc .: Acetaldehyde solution, sodium borohydride solution, hydrazine, ethanol, and the like.

  The polymer dispersant may be contained in at least one of the raw material solution A and the raw material solution B in any of the above reactions, but is preferably contained in the raw material solution B. For example, in the neutralization reaction I, it is preferable to use a raw material solution A containing a metal salt that is a raw material of a metal compound and a raw material solution B containing a neutralizing agent and a polymer dispersant.

The composition and combination of such raw material solutions can be appropriately set according to the type of the colloidal solution of the target metal compound and the type of raw material used. For example, when producing a colloidal solution of a metal oxide containing CeO ₂ , any raw material solution including a raw material solution A containing tetravalent cerium ions and a trivalent cerium ion can be used. However, when the latter raw material solution A is used, in order to oxidize to tetravalent cerium ions, the raw material solution B is equivalent to the cerium ions in the raw material solution A in addition to the neutralizing agent. It is preferable to use those containing hydrogen peroxide.

  In the production method of the present invention described above, two or more kinds of raw material solutions are not mixed in advance under a gentle stirring condition, and the stirring conditions are not different for each raw material solution. Since the mixture is homogeneously mixed under high shear force and aggregates are destroyed, the resulting metal compound crystallite aggregates have a small particle size and are uniform, and a colloidal solution with excellent storage stability can be obtained. Is possible.

  The composition of the colloidal solution of the metal compound obtained by the present invention is not particularly limited. By using various raw material solutions, it is possible to obtain colloidal solutions having various compositions such as metal oxides, metal hydroxides, and metal salts. It becomes.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

Example 1
Manufacturing apparatus shown in FIG. 1 with (super agitation reactor) to produce a colloidal solution of _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -component metal compound. The stator 13 was a 48-hole type in which 24 nozzles 16A and 24 nozzles 16B were provided.

  First, 12.7 g of cerium acetate monohydrate (III), 12.8 g of zirconium oxyacetate and 1.7 g of yttrium acetate tetrahydrate were dissolved in 500 g of ion-exchanged water, and the cation concentration was 0.1 mol / L. A raw material aqueous solution (raw material solution A) was prepared. Further, 23.2 g of ammonium acetate, 13.6 g of hydrogen peroxide water and 140 g of polyacrylic acid sodium salt (weight average molecular weight: 1200, ratio of those having a hydrophilic group among all repeating units: 100%) were added to 360 g of ion-exchanged water. The polymer dispersant aqueous solution (raw material solution B) was prepared.

  As shown in FIG. 1, the tip of the homogenizer 10 is set so as to be immersed in a 100 ml beaker 20, and the raw material solution A and the raw material solution B are respectively rotated while rotating the rotor 11 in the homogenizer 10 at a rotational speed of 10,000 rpm. Using a tube pump (not shown) at a supply rate of 5 ml / min, liquid was fed from the nozzle 16A and nozzle 16B to the region between the rotor 11 and the inner stator 13 and mixed to prepare a colloidal solution of the metal compound. .

The outer diameter of the rotor 11 was 17.8 mm, the gap between the rotor 11 and the outer stator 12 was 0.5 mm, and the shear rate in the region between them was 18730 sec ⁻¹ . The outer diameter of the inner stator 13 was 12.2 mm, the gap between the rotor 11 and the inner stator 13 was 0.5 mm, and the shear rate in the region between them was 18730 sec ⁻¹ . Further, the time from when the raw material solution A and the raw material solution B were introduced into the region until they were homogeneously mixed was 0.126 msec. Here, the time until homogeneous mixing is defined as the time until the raw material solution A or the raw material solution B discharged from the nozzle 16A or the nozzle 16B reaches the adjacent nozzle 16B or the nozzle 16A by the rotation of the rotor 11. It is what is done.

  The neutralized colloidal solution overflowing from the beaker 20 was received by setting a 1 L beaker (not shown) further below the beaker 20.

The pH of the obtained colloidal solution of the metal compound is shown in Table 1. A part of the colloidal solution was dried at 80 ° C. for 24 hours to prepare a powder sample. This sample was subjected to electron diffraction measurement with a high resolution transmission electron microscope (high resolution TEM). From the obtained electron beam diffraction pattern, the metal compound had a fluorite structure and a single phase CeO ₂ —ZrO ₂ —Y ₂ O. ₃ It was confirmed to be a ternary complex oxide single crystal. Further, a high-resolution TEM photograph of this sample was taken, 50 metal compound crystallites in the TEM photograph were extracted, and the crystallite diameter was directly measured to obtain the particle size distribution. The result shown in FIG. was gotten. From this particle size distribution of the metal compound crystallites, a crystallite diameter d ₅₀ (average crystallite diameter) at which the cumulative number of metal compounds becomes 50% is obtained, and a specific surface area of the metal compound crystallites is calculated to obtain a metal compound crystallite. The content of the polymer dispersant per unit surface area was determined. These results are shown in Table 1.

Next, when the particle size distribution of the fine particles in the colloidal solution was measured by a dynamic light scattering method (using “Nanotrac250” manufactured by Nikkiso Co., Ltd.), a particle size distribution as shown in FIG. 5 was obtained. From the particle size distribution of the fine particles in the colloidal solution, the particle diameter D ₅₀ (average crystallite diameter) at which the cumulative mass becomes 50% was determined. The results are shown in Table 1. Since the larger the particle diameter D ₅₀ of the particles in the colloidal solution than the crystallite size d _50, crystallites of a metal compound in the colloidal solution, it was confirmed that form aggregates.

Further, the crystallite diameter d _{90 at} which the cumulative number becomes 90% is obtained from the particle size distribution of the crystallites of the metal compound, and the aggregated particle diameter D _{90 at} which the cumulative mass becomes 90% is obtained from the particle size distribution of the fine particles in the colloid solution. Asked. Furthermore, the left colloidal solution 30 days to measure the particle size distribution of the aggregate in the same manner as described above to determine the agglomerated particle size D ₅₀ which cumulative mass is 50%. These results are shown in Table 1.

(Example 2)
Instead of polyacrylic acid sodium salt having a weight average molecular weight of 1200, a polyacrylic acid ammonium salt having a weight average molecular weight of 2000 (ratio of those having a hydrophilic group among all repeating units: 100%) was used as the polymer dispersant. A metal compound colloidal solution was prepared in the same manner as in Example 1 except for the above.

The metal compound in the obtained colloidal solution was subjected to high-resolution TEM electron diffraction measurement in the same manner as in Example 1. As a result, the metal compound had a fluorite structure and a single-phase CeO ₂ —ZrO ₂ —Y ₂ O. ₃ It was confirmed to be a ternary complex oxide single crystal. Further, in the same manner as in Example 1, the pH of the colloidal solution, the content of the polymer dispersant, the crystallite diameters d ₅₀ and d ₉₀ , and the aggregate particle diameters D ₅₀ and D ₉₀ were determined. These results are shown in Table 1.

( Comparative Example 1 )
Instead of the polyacrylic acid sodium salt having a weight average molecular weight of 1200, a polyacrylic acid sodium salt having a weight average molecular weight of 8000 (ratio of those having a hydrophilic group among all repeating units: 100%) was used as the polymer dispersant. A metal compound colloidal solution was prepared in the same manner as in Example 1 except for the above.

The metal compound in the obtained colloidal solution was subjected to high-resolution TEM electron diffraction measurement in the same manner as in Example 1. As a result, the metal compound had a fluorite structure and a single-phase CeO ₂ —ZrO ₂ —Y ₂ O. ₃ It was confirmed to be a ternary complex oxide single crystal. Further, in the same manner as in Example 1, the pH of the colloidal solution, the content of the polymer dispersant, the crystallite diameters d ₅₀ and d ₉₀ , and the aggregate particle diameters D ₅₀ and D ₉₀ were determined. These results are shown in Table 1.

( Comparative Example 2 )
Raw material aqueous solution in which 1.27 g of cerium acetate monohydrate (III), 1.28 g of zirconium oxyacetate and 0.17 g of yttrium acetate tetrahydrate are dissolved in 500 g of ion-exchanged water and the cation concentration is 0.01 mol / L. Was prepared. Further, 2.32 g of ammonium acetate, 1.36 g of hydrogen peroxide water and 14.0 g of polyacrylic acid sodium salt (weight average molecular weight: 2000, ratio of those having a hydrophilic group among all repeating units: 100%) were ion-exchanged. It melt | dissolved in 496 g of water, and prepared polymer dispersing agent aqueous solution. A colloidal solution of a metal compound was prepared in the same manner as in Example 1 except that these raw material aqueous solution and polymer dispersant aqueous solution were used as raw material solutions A and B, respectively.

The metal compound in the obtained colloidal solution was subjected to high-resolution TEM electron diffraction measurement in the same manner as in Example 1. As a result, the metal compound had a fluorite structure and a single-phase CeO ₂ —ZrO ₂ —Y ₂ O. ₃ It was confirmed to be a ternary complex oxide single crystal. Further, in the same manner as in Example 1, the pH of the colloidal solution, the content of the polymer dispersant, the crystallite diameters d ₅₀ and d ₉₀ , and the aggregate particle diameters D ₅₀ and D ₉₀ were determined. These results are shown in Table 1.

( Example 3 )
Ammonium acetate 23.2 g, hydrogen peroxide solution 13.6 g and ammonium salt of acrylic acid / methyl acrylate copolymer (weight average molecular weight: 2000, proportion of those having a hydrophilic group among all repeating units: 75%, total 140 g of a repeating unit having a hydrophobic group (25%) was dissolved in 360 g of ion-exchanged water. Aqueous polymer dispersant solution was prepared by adding aqueous ammonia to this solution so that the resulting colloidal solution had a pH of 9. A colloidal solution of a metal compound was prepared in the same manner as in Example 1 except that this polymer dispersant aqueous solution was used as the raw material solution B.

The metal compound in the obtained colloidal solution was subjected to high-resolution TEM electron diffraction measurement in the same manner as in Example 1. As a result, the metal compound had a fluorite structure and a single-phase CeO ₂ —ZrO ₂ —Y ₂ O. ₃ It was confirmed to be a ternary complex oxide single crystal. Further, in the same manner as in Example 1, the pH of the colloidal solution, the content of the polymer dispersant, the crystallite diameters d ₅₀ and d ₉₀ , and the aggregate particle diameters D ₅₀ and D ₉₀ were determined. These results are shown in Table 1.

( Comparative Example 3 )
The raw material solutions A and B prepared in the same manner as in Example 1 were mixed in a beaker and stirred at a rotation speed of 100 rpm using a stirrer to prepare a colloidal solution of a metal compound. The metal compound in the obtained colloidal solution was subjected to high-resolution TEM electron diffraction measurement in the same manner as in Example 1. As a result, the metal compound had a fluorite structure and a single-phase CeO ₂ —ZrO ₂ —Y ₂ O. ₃ It was confirmed to be a ternary complex oxide single crystal. Further, in the same manner as in Example 1, the pH of the colloidal solution, the content of the polymer dispersant, the crystallite diameters d ₅₀ and d ₉₀ , and the aggregate particle diameters D ₅₀ and D ₉₀ were determined. These results are shown in Table 1.

( Comparative Example 4 )
A colloidal solution of a metal compound was prepared in the same manner as in Example 1 except that the raw material solution A and the raw material solution B were fed without rotating the rotor 11. The metal compound in the obtained colloidal solution was subjected to high-resolution TEM electron diffraction measurement in the same manner as in Example 1. As a result, the metal compound had a fluorite structure and a single-phase CeO ₂ —ZrO ₂ —Y ₂ O. ₃ It was confirmed to be a ternary complex oxide single crystal. Further, in the same manner as in Example 1, the pH of the colloidal solution, the content of the polymer dispersant, the crystallite diameters d ₅₀ and d ₉₀ , and the aggregate particle diameters D ₅₀ and D ₉₀ were determined. These results are shown in Table 1.

( Comparative Example 5 )
A colloidal solution of a metal compound was prepared in the same manner as in Example 1 except that the rotation speed of the rotor 11 was changed to 1000 rpm. In this case, the shear rate in the region between the rotor 11 and the outer stator 12 was 1873 sec ⁻¹ , and the shear rate in the region between the rotor 11 and the inner stator 13 was 1873 sec ⁻¹ . Further, the time from when the raw material solution A and the raw material solution B were introduced into the region until they were homogeneously mixed was 1.26 msec.

The metal compound in the obtained colloidal solution was subjected to high-resolution TEM electron diffraction measurement in the same manner as in Example 1. As a result, the metal compound had a fluorite structure and a single-phase CeO ₂ —ZrO ₂ —Y ₂ O. ₃ It was confirmed to be a ternary complex oxide single crystal. Further, in the same manner as in Example 1, the pH of the colloidal solution, the content of the polymer dispersant, the crystallite diameters d ₅₀ and d ₉₀ , and the aggregate particle diameters D ₅₀ and D ₉₀ were determined. These results are shown in Table 1.

( Comparative Example 6 )
Ammonium acetate (23.2 g) and hydrogen peroxide water (13.6 g) were dissolved in ion-exchanged water (500 g). A colloidal solution of a metal compound was prepared in the same manner as in Example 1 except that this aqueous solution containing no polymer dispersant was used as the raw material solution B.

The metal compound in the obtained colloidal solution was subjected to high-resolution TEM electron diffraction measurement in the same manner as in Example 1. As a result, the metal compound had a fluorite structure and a single-phase CeO ₂ —ZrO ₂ —Y ₂ O. ₃ It was confirmed to be a ternary complex oxide single crystal. In the same manner as in Example 1, the pH of the colloidal solution, the crystallite diameters d ₅₀ and d ₉₀ , and the aggregated particle diameters D ₅₀ and D ₉₀ were determined. These results are shown in Table 1.

( Comparative Example 7 )
First, 12.7 g of cerium acetate monohydrate (III), 12.8 g of zirconium oxyacetate and 1.7 g of yttrium acetate tetrahydrate were dissolved in 500 g of ion-exchanged water, and the cation concentration was 0.1 mol / L. A raw material aqueous solution (raw material solution A) was prepared. Further, 31.6 g of diethanolamine, 13.6 g of hydrogen peroxide water and 0.68 g of polyethylene glycol having a weight average molecular weight of 20000 were dissolved in 500 g of ion-exchanged water to prepare an aqueous polymer dispersant solution (raw material solution B).

  These raw material solutions A and B were mixed in a beaker, and nitric acid was added to adjust the pH to 3. This solution was subjected to ultrasonic treatment for 30 minutes using an ultrasonic homogenizer with a vibration frequency of 20 kHz, an amplitude of 30 μm, and an output of 200 W to prepare a colloidal solution of a metal compound.

The metal compound in the obtained colloidal solution was subjected to high-resolution TEM electron diffraction measurement in the same manner as in Example 1. As a result, the metal compound had a fluorite structure and a single-phase CeO ₂ —ZrO ₂ —Y ₂ O. ₃ It was confirmed to be a ternary complex oxide single crystal. Further, in the same manner as in Example 1, the pH of the colloidal solution, the content of the polymer dispersant, the crystallite diameters d ₅₀ and d ₉₀ , and the aggregate particle diameters D ₅₀ and D ₉₀ were determined. These results are shown in Table 1. FIG. 5 shows the particle size distribution of particles (aggregates) in the colloidal solution.

  In addition, the colloidal solution of the obtained metal compound was subjected to centrifugal acceleration sedimentation treatment to remove larger aggregate particles, and an attempt was made to collect only the supernatant liquid. Only the aggregate remained, and most of the sample was removed as a precipitate.

As is clear from the results shown in FIG. 5 and Table 1, in the colloidal solution of the metal compound ( Examples 1 to 3 ) obtained by mixing the raw material solution under high shear force by the production method of the present invention, It was confirmed that metal compound crystallites having a crystallite size of nano-order and a narrow particle size distribution were included in an aggregate state in which the aggregate particle size was nano-order and the particle size distribution was narrow. Moreover, even if it preserve | saved for 30 days, the change was not looked at by the particle diameter of the aggregate, and the colloidal solution obtained in Examples 1-3 was excellent in the preservability.

  On the other hand, when diethanolamine and polyethylene glycol are added and the pH is adjusted to 3 and sonication is performed (Comparative Example 7), the metal compound crystallite having a crystallite size of nano-order has an aggregate particle size of sub- It was contained in the state of an aggregate of micron order and was inferior in dispersibility. In addition, since the temperature of the aqueous solution slightly increased due to the ultrasonic treatment, it is surmised that a part of the crystallites grew and the particle size distribution width increased. Furthermore, in the colloidal solution preserve | saved for 30 days, the particle diameter of the aggregate became still larger and it was inferior to preservability.

Further, as is clear from the results shown in Table 1, when mixing is performed using a stir bar ( Comparative Example 3 ), when no shear force is applied to the reaction field ( Comparative Example 4 ), and when the reaction field is low In the case where a shearing force was applied ( Comparative Example 5 ) and in the case where no polymer dispersant was added ( Comparative Example 6 ), the metal compound crystallites having a crystallite size of nano-order had an aggregate particle diameter of micron-order. It was contained in the state of an aggregate and was inferior in dispersibility.

Further, when Examples 1-2 and Comparative Example 1 are compared, the average crystallite diameter (d ₅₀ ) and the particle size distribution width (d ₉₀ / d ₅₀ ) of the metal compound crystallites even when the molecular weight of the polymer dispersant increases. However, it was confirmed that the average particle diameter (D ₅₀ ) of the aggregates increased as the molecular weight of the polymer dispersant increased. Further, when Example 1 and Comparative Example 2 are compared, the average crystallite diameter (d ₅₀ ) and particle size distribution width (d ₉₀ / d ₅₀ ) of the metal compound crystallites even when the content of the polymer dispersant increases. However, it was confirmed that the average particle diameter (D ₅₀ ) of the aggregates increased as the content of the polymer dispersant increased.

  As described above, according to the present invention, it is possible to obtain a colloidal solution in which crystallites of a metal compound having a small particle size and a narrow particle size distribution are dispersed in an aggregate state having a small particle size and a narrow particle size distribution. .

  Therefore, the colloidal solution of the metal compound of the present invention is a highly dispersed nano-sized agglomerate of metal compound crystallites. Therefore, the nano-size effect is expected to be exhibited in various applications. It is useful as a starting material for a catalyst carrier having an excellent balance with the specific surface area.

It is a schematic longitudinal cross-sectional view which shows suitable one Embodiment of the manufacturing apparatus of the metal compound colloid solution used for this invention. FIG. 2 is an enlarged longitudinal sectional view showing a tip portion (stirring portion) of the homogenizer 10 shown in FIG. 1. It is a side view of the inner side stator 13 shown in FIG. It is a cross-sectional view of the inner stator 13 shown in FIG. It is a graph which shows the result of having measured the particle size distribution (cumulative number) of the crystallite of the metal compound in the colloidal solution obtained in Example 1 and Comparative Example 7 , and the particle size distribution (cumulative mass) of the aggregate.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Homogenizer, 11 ... Rotor, 12 ... Outer stator, 13 ... Inner stator, 14 ... Rotating shaft, 15 ... Motor, 16A, 16B ... Nozzle, 17A, 17B ... Flow path (supply pipe), 20 ... Reaction vessel, A , B ... reaction solution, X ... rotation axis, Y ... surface perpendicular to the rotation axis X.

Claims (10)

A colloidal solution of a metal compound produced by mixing two or more kinds of raw material solutions,
At least one of the two or more raw material solutions contains a metal ion that is a raw material of the metal compound, and at least one of the two or more raw material solutions is (meth) acrylic acid. A homopolymer of (meth) acrylic acid and a copolymer of (meth) acrylic acid ester, and at least one selected from the group consisting of sodium salts and ammonium salts thereof having a weight average molecular weight of 800 to 3000 It contains a (meth) acrylic acid polymer,
Arranged so that a predetermined gap region is formed between the rotor and the outer stator arranged to form a predetermined gap region between the rotor and the inner periphery of the rotor. Using a homogenizer with an inner stator
Each of the raw material solutions is directly and independently introduced into a region formed by rotating the rotor and having a shear rate of 3000 sec ⁻¹ or more, and obtained by homogeneous mixing.
Cumulative number 50 percent becomes the crystallite size d ₅₀ is 0.8~3nm and crystallite diameter d ₉₀ is the crystallite size of which cumulative number of 90% at a measuring particle size distribution by transmission electron microscopy and aggregates of crystallites of the metal compound is 1.5 times the d _50, containing said (meth) acrylic polymer,
The aggregate, cumulative mass 50% become agglomerated particle size D ₅₀ is 4~9nm and cumulative mass the agglomeration particle size D ₉₀ comprised 90% of the measured particle size distribution by a dynamic light scattering method The aggregated particle diameter D is 2.5 times or less of ₅₀ ,
The (meth) 9~15mg / m ² der content of the acrylic polymer is to the unit surface area of the crystallites of the metal compound is,
pH is 5.0-10.0 ,
A colloidal solution of a metal compound characterized by the above. The ratio of those having a hydrophilic group among all repeating units in the (meth) acrylic acid polymer is 90% or more and 100% or less when the pH of the colloidal solution is 5.0 or more and less than 7.0. , colloidal solution of metal compound of claim 1 in which the pH of the colloidal solution, characterized in that in the case of 7.0 to 10.0 at 50% to 100%. At least one of the two or more raw material solutions contains the metal ion, and at least one of the remaining raw material solutions contains the (meth) acrylic acid polymer. A colloidal solution of a metal compound according to claim 1 or 2 . The raw material solution containing the metal ions is a solution containing a metal salt that is a raw material of the metal compound, and the raw material solution containing the (meth) acrylic acid polymer further contains a neutralizing agent. A colloidal solution of the metal compound according to claim 3 . Colloidal solution of metal compound according to any one of claims 1-4 for cation concentration of raw material solution containing the metal ions is characterized by a 0.01 to 0.5 mol / L. A method for producing a colloidal solution of a metal compound by mixing two or more raw material solutions,
At least one of the two or more raw material solutions contains a metal ion that is a raw material of the metal compound, and at least one of the two or more raw material solutions is (meth) acrylic acid. A homopolymer of (meth) acrylic acid and a copolymer of (meth) acrylic acid ester, and at least one selected from the group consisting of sodium salts and ammonium salts thereof having a weight average molecular weight of 800 to 3000 It contains a (meth) acrylic acid polymer,
Arranged so that a predetermined gap region is formed between the rotor and the outer stator arranged to form a predetermined gap region between the rotor and the inner periphery of the rotor. Using a homogenizer with an inner stator
In the region formed by rotating the rotor and having a shear rate of 3000 sec ⁻¹ or more, the content of the (meth) acrylic acid polymer in the colloid solution is the unit surface area of the crystallite of the metal compound. In contrast, each raw material solution is directly and independently introduced so as to be 9 to 15 mg / m ^2, and homogeneously mixed .
A method for producing a colloidal solution of a metal compound , wherein the pH of the obtained colloidal solution is adjusted to 5.0 to 10.0 . At least one of the two or more raw material solutions contains the metal ion, and at least one of the remaining raw material solutions contains the (meth) acrylic acid polymer. The method for producing a colloidal solution of a metal compound according to claim 6 . The raw material solution containing the metal ions is a solution containing a metal salt that is a raw material of the metal compound, and the raw material solution containing the (meth) acrylic acid polymer further contains a neutralizing agent. A method for producing a colloidal solution of a metal compound according to claim 7 . The colloidal solution of a metal compound according to any one of claims 6 to 8 , wherein the cation concentration of the raw material solution containing the metal ions is 0.01 to 0.5 mol / L. Production method. The pH of the colloidal solution is adjusted to 5.0 or more and 10.0 or less when the ratio of those having a hydrophilic group among all repeating units in the (meth) acrylic acid polymer is 90% or more and 100% or less. and, to claim 6-9 proportion of the repeating unit having a hydrophilic group, which comprises adjusting the pH of the colloidal solution to 7.0 to 10.0 in the case is less than 50% 90% A method for producing a colloidal solution of the metal compound described.

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