JP2010110719A - Colloidal solution of metallic compound, and method of producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a colloidal solution of a metallic compound excellent in preservability, wherein uniform crystallites of a metallic compound having small diameters are dispersed as they are or in a state of uniform aggregates thereof having small diameters, and a method of producing the same. <P>SOLUTION: The colloidal solution of a metallic compound including crystallites of a metallic compound having a crystallite diameter d<SB>50</SB>of 0.8 to 3 nm whereat the cumulative number of the crystallite particles in the particle size distribution reaches 50% and having a crystallite diameter d<SB>90</SB>1.5 times or lower the crystallite diameter d<SB>50</SB>whereat the cumulative number of the crystallite particles reaches 90%, and a polyalkyleneimine of a weight-average molecular weight of 3,000 to 15,000, is characterized in that the pH of the colloidal solution is 1.0 to 6.0, and microparticles dispersed therein are crystallites of a metallic compound having a particle diameter D<SB>50</SB>of 0.8 to 70 nm whereat the cumulative mass in the particle size distribution reaches 50% and having a particle diameter D<SB>90</SB>2.0 times or lower the particle diameter D<SB>50</SB>whereat the cumulative mass reaches 90%, and/or the aggregates thereof. <P>COPYRIGHT: (C)2010,JPO&INPIT

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-described problems of the prior art, and the crystallites of the metal compound having a small diameter and uniform are dispersed as they are or in the form of uniform aggregates having a small diameter, and It is an object of the present invention to provide a colloidal solution of a metal compound excellent in preservability and a method for producing the same.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have a high reaction site with two or more raw material solutions containing a metal ion that is a raw material of a metal compound and a polyalkyleneimine having a predetermined molecular weight. It has been found that a homogeneous colloidal solution in which crystallites of a uniform metal compound with a small diameter are dispersed in the same state or in a state of uniform aggregates with a small diameter is obtained by homogeneously mixing so as not to apply a shearing force. The present invention has been completed.

That is, a colloidal solution of the metal compounds of the present invention, the crystallite size _{d 90} of and cumulative number is the crystallite size _{d 50} of the cumulative number of 50% at a particle size distribution 0.8~3nm is 90% the A colloid solution containing a crystallite of a metal compound having a crystallite diameter d ₅₀ of 1.5 times or less and a polyalkyleneimine having a weight average molecular weight of 3000 to 15000, the colloid solution having a pH of 1.0. is 6.0, particulates dispersed in the colloid solution is, the particle diameter _{D 50} which cumulative mass in the particle size distribution is 50% becomes a and and cumulative mass 90% 0.8~70nm particles diameter D ₉₀ of a crystallite and / or aggregates of the metal compound is 2.0 times or less of the particle diameter D _50, it is characterized in. In such a colloidal solution, the content of the polyalkyleneimine is preferably 10 to 35 mg / m ² with respect to the unit surface area of the crystallite of the metal compound.

The colloid solution 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 a raw material of the metal compound. It contains a certain metal ion, and at least one of the two or more raw material solutions contains a polyalkylenimine having a weight average molecular weight of 3000 to 15000, and has a shear rate of 7500 sec ⁻¹ or less. It is preferable that the raw material solutions are directly directly introduced into the formed region and mixed homogeneously, and the solution is prepared by adjusting the pH of the solution to 1.0 to 6.0.

  In such a method for producing a colloidal solution, at least one of the two or more kinds of raw material solutions contains the metal ion, and at least one of the remaining raw material solutions contains the polyalkylene. It is preferable to use a material containing imine, the raw material solution containing metal ions is a solution containing a metal salt that is a raw material of the metal compound, and the raw material solution containing polyalkyleneimine is further neutralized More preferably, it contains an agent. Moreover, it is preferable that the cation density | concentration of the raw material solution containing the said metal ion is 0.005-0.5 mol / L.

  The reason why the present invention can provide a colloidal solution in which crystallites of a metal compound having a small diameter and a uniform size are dispersed as they are or in a state of uniform aggregates having a small diameter is not necessarily clear. They guess 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 presumed that the polyalkyleneimine used in the present invention also adsorbs to the nanoparticles and suppresses aggregation. At this time, when a high shear force is applied to the reaction field, aggregates having a large particle diameter tend to be formed. This is because the polyalkyleneimine is destroyed by a high shearing force, so even if the broken polyalkyleneimine is adsorbed to the nanoparticles, a sufficient repulsive force cannot be imparted, and the nanoparticles and aggregates thereof aggregate. This is presumed to be due to this.

  Further, when diethanolamine and polyethylene glycol are added, aggregates having a large particle size tend to be formed. This is because diethanolamine added to produce a 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 fully exhibited, and diethanolamine is not 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, a polyalkyleneimine having a predetermined molecular weight is added so as not to give a high shearing force to the reaction field, so that the polyalkyleneimine is adsorbed to the nanoparticles without being destroyed, A sufficient repulsive force is imparted to the nanoparticles, and the nanoparticles are presumed to exist in the colloidal solution as they are or in the form of aggregates having a relatively small particle diameter. In addition, since polyalkyleneimines exist stably in colloidal solutions, it is difficult to form aggregates with large particle diameters, and nanoparticles remain in the colloidal solution as they are or in the form of aggregates with relatively small particle diameters. It is inferred that they are stably dispersed.

  According to the present invention, it is possible to obtain a metal compound colloidal solution in which crystallites of a metal compound having a small diameter are dispersed as they are or in a state of uniform aggregates having a small diameter and excellent in storage stability. Is possible.

  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 A colloidal solution containing crystallites of a metal compound having a diameter d ₅₀ or less of a diameter d ₅₀ and a polyalkyleneimine having a weight average molecular weight of 3000 to 15000, the colloidal solution having a pH of 1.0 to 6 0.0, and the fine particles dispersed in the colloidal solution have a particle size D _{50 at} which the cumulative mass in the particle size distribution is 50%, the particle size D ₅₀ is 0.8 to 70 nm, and the cumulative mass is 90%. ₉₀ is characterized in that a crystallite and / or aggregates of the metal compound is 2.0 times or less of the 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 0.8 to and cumulative number is 2.0 nm) is of a crystallite size _{d 90} comprising 90% is 1.5 times or less (preferably 1.3 times or less) of the crystallite size _{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, fine particles composed of such metal compound crystallites and / or aggregates thereof are dispersed. The particle size distribution of the fine particles in the colloidal solution can be measured by, for example, a dynamic light scattering method. Particles in the colloidal solution of the present invention, the particle diameter _{D 50} which cumulative mass in measured particle size distribution in this way is 50 percent 0.8～70Nm (preferably 0.8～30Nm, more preferably 0 8 to 9 nm) and a particle diameter D ₉₀ with a cumulative mass of 90% is 2.0 times or less (preferably 1.8 times or less) of the particle diameter D ₅₀ . The metal compound fine particles having such particle diameters D ₅₀ and D ₉₀ are useful as a catalyst carrier having an excellent balance between specific surface area and heat resistance. Further, when the metal compound fine particles are adsorbed on particles having an alumina skeleton, the pore size distribution of the metal compound fine particles can be arbitrarily controlled by changing the pore diameter of the particles having an alumina skeleton. . When the metal compound fine particles are aggregates of metal compound crystallites, crystallites having a size corresponding to the particle diameter of the aggregates can be formed by heat-treating the aggregates. 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 polyalkyleneimine having a predetermined molecular weight. Due to the presence of such a polyalkyleneimine in the colloidal solution, the crystallites of the metal compound can be stably contained in the colloidal solution as it is or in the state of an aggregate having the particle size and the particle size distribution. It becomes possible to disperse.

  The weight average molecular weight of such a polyalkyleneimine is 3000-15000, and it is preferable that it is 8000-12000. When the weight average molecular weight of the polyalkyleneimine is within the above range, the metal compound crystallites are dispersed as they are or in the form of uniform aggregates having a small diameter, and a colloidal solution having excellent storage stability can be obtained. On the other hand, when the weight average molecular weight of the polyalkyleneimine is less than the lower limit, even if the polyalkyleneimine is adsorbed to the metal compound fine particles, the repulsive force due to steric hindrance is not sufficiently expressed, and the metal compound fine particles tend to aggregate, If the upper limit is exceeded, the polyalkyleneimine tends to form a crosslinked structure and a large aggregate. The weight average molecular weight is a value measured by gel permeation chromatography (GPC) and converted to standard polystyrene.

In the colloidal solution of the present invention, the polyalkyleneimine content is preferably 10 to 35 mg / m ^{2 and} more preferably 15 to 25 mg / m ² with respect to the unit surface area of the crystallite of the metal compound. When the polyalkyleneimine content is in the above range, the metal compound crystallites are dispersed as they are or in the form of uniform aggregates having a small diameter, and a colloidal solution having excellent storage stability can be obtained. On the other hand, if the content of the polyalkyleneimine is less than the lower limit, the surface of the metal compound fine particles cannot be sufficiently covered with the polyalkyleneimine, and the metal compound fine particles tend to aggregate to form larger aggregates. On the other hand, if the upper limit is exceeded, a large amount of free polyalkyleneimine is present in the colloidal solution, so that the crosslinking reaction of polyalkyleneimine proceeds remarkably and aggregates having a large particle size tend to be formed.

Moreover, the colloidal solution of the present invention has a pH of 1.0 to 6.0, preferably 3.0 to 5.0. When the pH of the colloidal solution is within the above range, the polyalkyleneimine dissociates to form NH ₃ ⁺ groups, which are adsorbed on the negatively charged sites or neutral sites of the metal compound crystallites to give a dispersion effect. As a result, the metal compound crystallites are dispersed as they are or in the form of uniform aggregates having a small diameter, and a colloidal solution having excellent storage stability can be obtained. On the other hand, when the pH is less than the lower limit, the surface of the metal compound crystallite is large and positively charged. Therefore, the polyalkyleneimine formed by dissociation and forming NH ₃ ⁺ groups is difficult to be adsorbed on the metal compound crystallite, and between the metal compound fine particles. However, when the above upper limit is exceeded, the degree of dissociation of the polyalkyleneimine is small, and the amount of polyalkyleneimine adsorbed on the metal compound fine particles decreases. In addition, sufficient repulsive force is not expressed between the metal compound fine particles, and the metal compound fine particles tend to aggregate.

  Examples of the solvent used in the present invention include water, water-soluble organic solvents (methanol, ethanol, propanol, isopropanol, butanol, acetone, etc.), a mixed solvent of water and the water-soluble organic solvent, and the like. The polyalkyleneimine according to the present invention tends to exhibit an excellent dispersion effect when such a solvent is used.

Such a colloidal solution of the metal compound of the present invention is prepared, for example, by stirring the raw material solution containing the metal ion and the raw material solution containing the polyalkyleneimine under conditions that do not give a high shear force to the reaction field. It can manufacture by carrying out homogeneous mixing using a child etc. Also, the colloidal solution of the metal compound of the present invention is a method of mixing two or more kinds of raw material solutions, and uses one containing the metal ions as at least one of the two or more kinds of raw material solutions. , Using at least one of the two or more kinds of raw material solutions containing the polyalkyleneimine, and directly introducing these raw material solutions directly into a region having a low shear rate of 7500 sec ⁻¹ or less. It is also possible to manufacture by a homogeneous mixing method. In particular, according to the latter method, it is possible to disperse the metal compound crystallite as it is or even in the form of a uniform aggregate with a smaller diameter, even in a solvent in which the metal compound crystallite easily aggregates. It becomes.

  As an apparatus used for the latter manufacturing method, 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 stirring device, and a front end portion (stirring portion) of the homogenizer 10 is disposed in the reaction vessel 20. As shown in FIG. 2, the tip 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. Further, the rotor 11 is connected to a motor 15 via a rotating shaft 14 and has a structure capable of rotating.

  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 nozzles 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 nozzle 16A and the nozzle 16B is not particularly limited and varies depending on the size of the apparatus, but 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 7500 sec ^-1 or less, and particularly preferably 6500Sec ^-1 or less. If the shear rate in this region exceeds the upper limit, the polyalkyleneimine is destroyed and sufficient repulsive force cannot be imparted to the metal compound fine particles, and a larger aggregate tends to be formed. Furthermore, the preferably at least 500 sec ^-1 as the lower limit of the shear rate, 1800 sec ^-1 or more is more preferable.

  Conditions for achieving such a low 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 of 0.5 mm between the rotor 11 and the inner stator 13, the shear speed is achieved by setting the rotational speed of the rotor 11 to preferably 300 to 4000 rpm, more preferably 1000 to 3500 rpm. It becomes possible.

  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, 0.5 to 1 More preferably, it is 0.0 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, 0.5 to 1 More preferably, it is 0.0 mm. By adjusting the rotational speed of the rotor 11 in response to the change in the size of the gap, it is 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, effective shearing force cannot be applied.

  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 nozzle 16B adjacent to the raw material solution A (or raw material solution B) introduced from the nozzle 16A (or nozzle 16B). It means the time until the position of (or nozzle 16A) is reached and mixed with raw material solution B (or raw material solution A) introduced from nozzle 16B (or nozzle 16A).

  As mentioned above, although the apparatus used suitably 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.

  Furthermore, as described above, two or more kinds of raw material solutions may be homogeneously mixed using a stirrer or the like under conditions that do not give a high shearing force to the reaction field.

  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, it is preferable that 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 so that the shear rate in the region between the above ranges 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. Each raw material solution directly introduced into the region having such a low shear rate is homogeneously mixed in an extremely short time to complete the reaction, and the crystallites of the metal compound derived from the raw material in the raw material solution And fine particles comprising the aggregates thereof are obtained. The metal compound crystallite obtained by such a method has a smaller crystallite diameter and a narrower particle size distribution. In addition, the aggregate of metal compound crystallites also has a smaller particle size and a narrower particle size distribution.

  Moreover, there is no restriction | limiting in particular as a liquid feeding rate of each raw material solution, However, 10-30 ml / min is preferable. 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. On the other hand, when the upper limit is exceeded, the particle diameter of the metal compound crystallite aggregates is large. Tend to be.

In the method for producing a colloidal solution of the present invention, the pH of the colloidal solution is adjusted to 1.0 to 6.0. When the pH of the colloidal solution is within the above range, the polyalkyleneimine dissociates to form NH ₃ ⁺ groups, which are adsorbed on the negatively charged sites or neutral sites of the metal compound crystallites to impart a dispersion effect. As a result, the metal compound crystallites are dispersed as they are or in the form of uniform aggregates having a small diameter, and a colloidal solution having excellent storage stability can be obtained. Meanwhile, since the pH is lower than the lower limit surface of the metal compound crystallites increases positively charged, polyalkyleneimine NH ₃ ⁺ group formed by dissociation hardly adsorbed on the metal compound crystallites, metal compound fine particles between When the above upper limit is exceeded, the dissociation degree of polyalkyleneimine is small, and the amount of polyalkyleneimine adsorbed on the metal compound fine particles is reduced. Sufficient repulsive force is not expressed between the fine particles, and the metal compound fine particles are aggregated. From this point of view, it is preferable to adjust the pH of the colloidal solution to 3.0 to 5.0 in the production method of the present invention.

  When producing the colloidal solution of the present invention, the metal ions and the polyalkyleneimine may be contained in the same raw material solution, or may be contained in different raw material solutions. Preferably, at least one of the raw material solutions contains the metal ion, and at least one of the remaining raw material solutions contains the polyalkyleneimine. For example, when the manufacturing apparatus shown in FIG. 1 is used, both the metal ions and the polyalkyleneimine may be contained in the raw material solution A, or the raw material solution A contains the metal ions and the raw material solution B. May contain the polyalkyleneimine, but the latter is preferred.

  The cation concentration of the raw material solution containing the metal ions (for example, the raw material solution A) is preferably 0.005 to 0.5 mol / L, more preferably 0.01 to 0.2 mol / L. When the cation concentration is within the above range, the metal compound crystallites are dispersed as they are or in the form of uniform aggregates having a small diameter, 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. On the other hand, when the cation concentration exceeds the upper limit, the distance between the metal compound fine particles in the colloid solution is shortened. The imine cannot be adsorbed on the metal compound fine particles in an effective form, and the metal compound fine particles tend to aggregate.

  The reaction system applicable to the production of such a colloidal solution of the present invention is not particularly limited, and examples thereof include a hydrolysis reaction of alkoxide and a precipitation reaction using solubility change using a poor solvent. Even in a reaction with a very fast nucleation rate or reaction rate such as a redox reaction or a redox reaction, the metal compound fine particles have a small particle size and become uniform according to the above production method, and a colloidal solution having excellent storage stability can be obtained. The production method of the 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 polyalkyleneimine 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 the metal salt, which is a raw material for the metal compound, and a raw material solution B containing a neutralizing agent and a polyalkyleneimine.

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.

  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
Metal ion-containing raw material aqueous solution in which 20.9 g of diammonium cerium (IV) nitrate, 7.0 g of zirconium oxynitrate, and 2.3 g of yttrium nitrate are dissolved in 500 g of ion-exchanged water in a beaker, and the cation concentration is 0.1 mol / L. (Raw material solution A) was prepared. Moreover, following formula (1):

125 g of polyethyleneimine having a weight average molecular weight of 10,000 and 160 g of nitric acid
Was dissolved in 340 g of ion-exchanged water to prepare a polyethyleneimine aqueous solution (raw material solution B).

  The raw material solution A and the raw material solution B were mixed in a beaker and stirred at a rotational speed of 100 rpm with a magnetic stirrer using a stirrer to prepare a colloidal solution of a metal compound.

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 is performed with an electron beam diffraction measurement of the high-resolution transmission electron microscope (high resolution TEM), obtained the metal compound from the electron diffraction pattern _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Furthermore, a high-resolution TEM photograph was taken of this sample, 50 metal compound crystallites in the TEM photograph were extracted, and the crystallite diameter was directly measured to obtain the particle size distribution. 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 polyethyleneimine per unit surface area was determined. These results are shown in Table 1.

Next, the particle size distribution of the fine particles in the colloidal solution was measured by a dynamic light scattering method (using “Nanotrac 250” manufactured by Nikkiso Co., Ltd.). 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 determined from the particle size distribution of the crystallites of the metal compound, and the particle diameter D _{90 at} which the cumulative mass becomes 90% is determined from the particle size distribution of the fine particles in the colloid solution. It was. Furthermore, the left colloidal solution 30 days in the same manner as described above to measure the particle size distribution of the microparticles to determine the particle size D ₅₀ which cumulative mass is 50%. These results are shown in Table 1.

(Example 2)
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.

  Raw material solutions A and B were prepared in the same manner as in Example 1. 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 mixed while rotating the rotor 11 in the homogenizer 10 at a rotation speed of 300 rpm. Using a tube pump (not shown) at a supply rate of 5 ml / min, the solution is fed from the nozzle 16A and the 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. did.

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 562 sec ⁻¹ . The outer diameter of the inner stator 13 is 12.2 mm, the gap between the rotor 11 and the inner stator 13 is 0.5 mm, the shear rate in the region between them was 562sec ^-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 4.2 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.

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Further, in the same manner as in Example 1, the pH of the colloid solution and the content of polyethyleneimine were determined. These results are shown in Table 1. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound were dispersed as they were. Moreover, these particle size distribution in the same manner as in Example 1, the crystallite size _{d 50} and _{d 90,} was determined particle diameter _{D 50} and _{D 90} in the colloidal solution. These results are shown in Table 1.

(Example 3)
A colloidal solution of a metal compound was prepared in the same manner as in Example 2 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.

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Further, in the same manner as in Example 1, the pH of the colloid solution and the content of polyethyleneimine were determined. These results are shown in Table 1. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound were dispersed as they were. Moreover, these particle size distribution in the same manner as in Example 1, the crystallite size _{d 50} and _{d 90,} was determined particle diameter _{D 50} and _{D 90} in the colloidal solution. These results are shown in Table 1.

Example 4
A colloidal solution of a metal compound was prepared in the same manner as in Example 2 except that the rotation speed of the rotor 11 was changed to 3200 rpm. In this case, the shear rate in the region between the rotor 11 and the outer stator 12 was 6000 sec ⁻¹ , and the shear rate in the region between the rotor 11 and the inner stator 13 was 6000 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 0.394 msec.

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Further, in the same manner as in Example 1, the pH of the colloid solution and the content of polyethyleneimine were determined. These results are shown in Table 1. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound were dispersed as they were. Further, in the same manner as in Example 1, the crystallite diameters d ₅₀ and d ₉₀ and the particle diameters D ₅₀ and D ₉₀ in the colloid solution were obtained from these particle size distributions. These results are shown in Table 1.

(Example 5)
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 a metal ion having a cation concentration of 0.1 mol / L A containing raw material aqueous solution was prepared. Further, 23.2 g of ammonium acetate, 13.6 g of hydrogen peroxide water, 125 g of polyethyleneimine having a weight average molecular weight of 10000 represented by the above formula (1), and 130 g of acetic acid were dissolved in 355 g of ion-exchanged water, and an aqueous polyethyleneimine solution was obtained. Prepared.

  A metal compound colloidal solution was prepared by stirring with a magnetic stirrer using a stirrer in the same manner as in Example 1 except that the metal ion-containing raw material aqueous solution and the polyethyleneimine aqueous solution were used as the raw material solutions A and B, respectively. .

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Further, in the same manner as in Example 1, the pH of the colloid solution and the content of polyethyleneimine were determined. These results are shown in Table 1. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound formed aggregates. Further, in the same manner as in Example 1, the crystallite diameters d ₅₀ and d ₉₀ and the particle diameters D ₅₀ and D ₉₀ in the colloid solution were obtained from these particle size distributions. These results are shown in Table 1.

(Example 6)
A metal ion-containing raw material aqueous solution and a polyethyleneimine aqueous solution were prepared in the same manner as in Example 5, and these were used as the raw material solutions A and B, using the production apparatus shown in FIG. A colloidal solution was prepared.

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Further, in the same manner as in Example 1, the pH of the colloid solution and the content of polyethyleneimine were determined. These results are shown in Table 1. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound were dispersed as they were. Further, in the same manner as in Example 1, the crystallite diameters d ₅₀ and d ₉₀ and the particle diameters D ₅₀ and D ₉₀ in the colloid solution were obtained from these particle size distributions. These results are shown in Table 1.

(Example 7)
A colloidal solution of a metal compound was prepared in the same manner as in Example 6 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.

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Further, in the same manner as in Example 1, the pH of the colloid solution and the content of polyethyleneimine were determined. These results are shown in Table 1. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound were dispersed as they were. Further, in the same manner as in Example 1, the crystallite diameters d ₅₀ and d ₉₀ and the particle diameters D ₅₀ and D ₉₀ in the colloid solution were obtained from these particle size distributions. These results are shown in Table 1.

(Example 8)
A colloidal solution of a metal compound was prepared in the same manner as in Example 6 except that the rotation speed of the rotor 11 was changed to 3200 rpm. In this case, the shear rate in the region between the rotor 11 and the outer stator 12 was 6000 sec ⁻¹ , and the shear rate in the region between the rotor 11 and the inner stator 13 was 6000 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 0.394 msec.

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Further, in the same manner as in Example 1, the pH of the colloid solution and the content of polyethyleneimine were determined. These results are shown in Table 1. Further, for the fine particles in the obtained colloid solution, the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloid solution were determined in the same manner as in Example 1. These results are shown in FIG. The average particle diameter D ₅₀ of fine particles of a metal compound crystallites average crystallite size d ₅₀ and colloidal solution obtained from the particle size distribution shown in FIG. 5, crystallite metal compound in the colloidal solution is dispersed as it is It was confirmed that Further, in the same manner as in Example 1, the crystallite diameter d ₉₀ and the particle diameter D ₉₀ in the colloid solution were determined from these particle size distributions. These results are shown in Table 1.

Example 9
In the same manner as in Example 5, raw material solutions A and B were prepared and mixed, and stirred with a magnetic stirrer using a stirring bar. 1000 g of ethyl alcohol was added to the obtained colloidal solution, and further stirred with a magnetic stirrer using a stirrer at a rotation speed of 100 rpm to prepare a colloidal solution of a metal compound.

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Further, in the same manner as in Example 1, the pH of the colloid solution and the content of polyethyleneimine were determined. These results are shown in Table 1. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound formed aggregates. Further, in the same manner as in Example 1, the crystallite diameters d ₅₀ and d ₉₀ and the particle diameters D ₅₀ and D ₉₀ in the colloid solution were obtained from these particle size distributions. These results are shown in Table 1.

(Example 10)
23.2 g of ammonium acetate, 13.6 g of hydrogen peroxide, 62.5 g of polyethyleneimine having a weight average molecular weight of 10000 represented by the above formula (1), and 70 g of acetic acid are dissolved in 400 g of ion-exchanged water, and a polyethyleneimine aqueous solution is obtained. Prepared. A colloidal solution of a metal compound was prepared in the same manner as in Example 8 except that this aqueous solution was used as the raw material solution B.

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Further, in the same manner as in Example 1, the pH of the colloid solution and the content of polyethyleneimine were determined. These results are shown in Table 1. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound were dispersed as they were. Further, in the same manner as in Example 1, the crystallite diameters d ₅₀ and d ₉₀ and the particle diameters D ₅₀ and D ₉₀ in the colloid solution were obtained from these particle size distributions. These results are shown in Table 1.

(Example 11)
23.2 g of ammonium acetate, 13.6 g of hydrogen peroxide, 36.8 g of polyethyleneimine having a weight average molecular weight of 10000 represented by the above formula (1), and 35 g of acetic acid are dissolved in 465 g of ion-exchanged water. Prepared. A colloidal solution of a metal compound was prepared in the same manner as in Example 8 except that this aqueous solution was used as the raw material solution B.

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Further, in the same manner as in Example 1, the pH of the colloid solution and the content of polyethyleneimine were determined. These results are shown in Table 1. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound formed aggregates. Further, in the same manner as in Example 1, the crystallite diameters d ₅₀ and d ₉₀ and the particle diameters D ₅₀ and D ₉₀ in the colloid solution were obtained from these particle size distributions. These results are shown in Table 1.

Example 12
1.27 g of cerium acetate monohydrate (III), 1.28 g of zirconium oxyacetate and 0.17 g of yttrium acetate tetrahydrate were dissolved in 500 g of ion-exchanged water, and a metal ion having a cation concentration of 0.01 mol / L A containing raw material aqueous solution was prepared. Further, 2.32 g of ammonium acetate, 1.36 g of hydrogen peroxide water, 12.5 g of polyethyleneimine having a weight average molecular weight of 10000 represented by the above formula (1), and 10 g of acetic acid were dissolved in 485 g of ion-exchanged water, and polyethyleneimine was dissolved. An aqueous solution was prepared.

  A metal compound colloidal solution was prepared in the same manner as in Example 8 except that the metal ion-containing raw material aqueous solution and the polyethyleneimine aqueous solution were used as the raw material solutions A and B, respectively.

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Further, in the same manner as in Example 1, the pH of the colloid solution and the content of polyethyleneimine were determined. These results are shown in Table 1. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound were dispersed as they were. Therefore, in the same manner as in Example 1, the crystallite diameters d ₅₀ and d ₉₀ and the particle diameters D ₅₀ and D ₉₀ in the colloid solution were obtained from these particle size distributions. These results are shown in Table 1.

(Comparative Example 1)
Dissolved in 23.2 g of ammonium acetate and 13.6 g of hydrogen peroxide water 430 g of ion-exchanged water. A colloidal solution of a metal compound was prepared in the same manner as in Example 5 except that this aqueous solution was used as the raw material solution B.

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Further, the pH of the colloidal solution was determined in the same manner as in Example 1. The results are shown in Table 2. Further, for the fine particles in the obtained colloid solution, the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloid solution were determined in the same manner as in Example 1. It was confirmed that the crystallites of the metal compound formed aggregates. Further, in the same manner as in Example 1, the crystallite diameters d ₅₀ and d ₉₀ and the particle diameters D ₅₀ and D ₉₀ in the colloid solution were obtained from these particle size distributions. These results are shown in Table 2.

(Comparative Example 2)
A colloidal solution of a metal compound was prepared in the same manner as in Example 6 except that the rotation speed of the rotor 11 was changed to 10,000 rpm. In this case, the shear rate in the region between the rotor 11 and the outer stator 12 was 18730 sec ⁻¹ , and the shear rate in the region between the rotor 11 and the inner stator 13 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.

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Further, in the same manner as in Example 1, the pH of the colloid solution and the content of polyethyleneimine were determined. These results are shown in Table 2. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound formed aggregates. Moreover, these particle size distribution in the same manner as in Example 1, the crystallite size _{d 50} and _{d 90,} was determined particle diameter _{D 50} and _{D 90} in the colloidal solution. These results are shown in Table 2.

(Comparative Example 3)
A colloidal solution of a metal compound was prepared in the same manner as in Example 8 except that 125 g of polyethyleneimine having a weight average molecular weight of 600 represented by the above formula (1) was used instead of polyethyleneimine having a weight average molecular weight of 10,000.

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Further, in the same manner as in Example 1, the pH of the colloid solution and the content of polyethyleneimine were determined. These results are shown in Table 2. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound formed aggregates. Further, in the same manner as in Example 1, the crystallite diameters d ₅₀ and d ₉₀ and the particle diameters D ₅₀ and D ₉₀ in the colloid solution were obtained from these particle size distributions. These results are shown in Table 2.

(Comparative Example 4)
A colloidal solution of a metal compound was prepared in the same manner as in Example 8 except that 125 g of polyethyleneimine having a weight average molecular weight of 1800 represented by the formula (1) was used instead of polyethyleneimine having a weight average molecular weight of 10,000.

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Further, in the same manner as in Example 1, the pH of the colloid solution and the content of polyethyleneimine were determined. These results are shown in Table 2. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound formed aggregates. Further, in the same manner as in Example 1, the crystallite diameters d ₅₀ and d ₉₀ and the particle diameters D ₅₀ and D ₉₀ in the colloid solution were obtained from these particle size distributions. These results are shown in Table 2.

(Comparative Example 5)
A colloidal solution of a metal compound was prepared in the same manner as in Example 8 except that the amount of acetic acid added was changed to 100 g. Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Further, in the same manner as in Example 1, the pH of the colloid solution and the content of polyethyleneimine were determined. These results are shown in Table 2. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound formed aggregates. Further, in the same manner as in Example 1, the crystallite diameters d ₅₀ and d ₉₀ and the particle diameters D ₅₀ and D ₉₀ in the colloid solution were obtained from these particle size distributions. These results are shown in Table 2.

(Comparative Example 6)
A colloidal solution of a metal compound was prepared in the same manner as in Example 8 except that the amount of acetic acid added was changed to 50 g. Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Further, in the same manner as in Example 1, the pH of the colloid solution and the content of polyethyleneimine were determined. These results are shown in Table 2. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound formed aggregates. Further, in the same manner as in Example 1, the crystallite diameters d ₅₀ and d ₉₀ and the particle diameters D ₅₀ and D ₉₀ in the colloid solution were obtained from these particle size distributions. These results are shown in Table 2.

(Comparative Example 7)
A colloidal solution of a metal compound was prepared in the same manner as in Example 8 except that 125 g of polyvinylpyrrolidone having a weight average molecular weight of 10,000 was used instead of polyethyleneimine, the amount of ion exchange water was changed to 480 g, and acetic acid was not added. .

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Moreover, it carried out similarly to Example 1, and calculated | required pH of colloid solution and content of polyvinylpyrrolidone. These results are shown in Table 2. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound formed aggregates. Further, in the same manner as in Example 1, the crystallite diameters d ₅₀ and d ₉₀ and the particle diameters D ₅₀ and D ₉₀ in the colloid solution were obtained from these particle size distributions. These results are shown in Table 2.

(Comparative Example 8)
A colloidal solution of a metal compound was prepared in the same manner as in Example 8 except that 125 g of polyethylene glycol having a weight average molecular weight of 10,000 was used instead of polyethyleneimine, the amount of ion-exchanged water was changed to 480 g, and acetic acid was not added. .

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Moreover, it carried out similarly to Example 1, and calculated | required pH of colloid solution and content of polyethyleneglycol. These results are shown in Table 2. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound formed aggregates. Further, in the same manner as in Example 1, the crystallite diameters d ₅₀ and d ₉₀ and the particle diameters D ₅₀ and D ₉₀ in the colloid solution were obtained from these particle size distributions. These results are shown in Table 2.

(Comparative Example 9)
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 a polyethylene glycol aqueous 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. In addition, the addition amount of diethanolamine with respect to cerium ion was 3 molar equivalent, and the addition amount of polyethyleneglycol was 5 mass% of the produced | generated metal compound.

Similarly the metal compound resulting colloidal solution as in Example 1 to was subjected to electron beam diffraction measurement of the high-resolution TEM, the metal compound is _{CeO 2 -ZrO 2 -Y 2 O 3} 3 -element compound oxide It was confirmed to be a single crystal. Moreover, it carried out similarly to Example 1, and calculated | required pH of colloid solution and content of polyethyleneglycol. These results are shown in Table 2. Furthermore, when the particle size distribution of the metal compound crystallites and the particle size distribution of the fine particles in the colloidal solution were determined in the same manner as in Example 1 for the fine particles in the obtained colloidal solution, It was confirmed that the crystallites of the metal compound formed aggregates. Further, in the same manner as in Example 1, the crystallite diameters d ₅₀ and d ₉₀ and the particle diameters D ₅₀ and D ₉₀ in the colloid solution were obtained from these particle size distributions. These results are shown in Table 2. 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 only the supernatant was collected, but only a part (several percent) of fine particles remained, Most particles precipitated. Particle diameter _{D 50} of the particles in the supernatant is 20 _{nm, D 90} was 100 nm.

  As is apparent from the results shown in FIG. 5 and Table 1, in a colloidal solution of a metal compound obtained by adding a polyalkyleneimine having a predetermined molecular weight so that a high shear force is not applied to the reaction field, As the ion-containing raw material solution, the crystallite diameter is a nano-order particle in any of the cases containing nitrate (Examples 1 to 4) and the case containing acetate (Examples 5 to 12). It was confirmed that the metal compound crystallites having a narrow diameter distribution were dispersed as they were or in the form of aggregates having a particle size of nano-order and a narrow particle size distribution. Further, in the colloidal solutions obtained in Examples 5 to 8, even when stored for 30 days, no change was observed in the particle diameter of the metal compound crystallites and / or aggregates thereof, and the storage stability was excellent. It was a thing.

  On the other hand, as is clear from the results shown in Table 2, when the polyalkyleneimine according to the present invention is not added (Comparative Example 1), when polyvinylpyrrolidone is used instead of the polyalkyleneimine (Comparative Example 7), polyethylene In the case of using glycol (Comparative Example 8), the metal compound crystallite having a crystallite size of nano-order was dispersed in the state of an aggregate having a particle size of micron-order, and the dispersibility was poor. . This is presumed to be because the metal oxide fine particles have a high cohesive force in water or an aqueous solvent, and thus easily aggregate, and polyvinyl pyrrolidone and polyethylene glycol do not adsorb in such an effective form. The

  Further, as is clear from the results shown in FIG. 5 and Table 2, in the case where diethanolamine and polyethylene glycol were added, the pH was adjusted to 3, and the ultrasonic treatment was performed (Comparative Example 9), nano-order The metal compound crystallites were dispersed in a state of an aggregate having a particle size of submicron order, and the dispersibility was poor. 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 was inferior to preservability.

  Further, as apparent from the results shown in Table 2, when a high shear force is applied to the reaction field (Comparative Example 2), when a polyalkyleneimine having a low molecular weight is added (Comparative Examples 3 to 4), and colloid In the case where the pH of the solution is high (Comparative Examples 5 to 6), the metal compound crystallite having a crystallite size of nano-order is contained in the state of an aggregate having a particle size of submicron to micron-order, and thus dispersibility. It was inferior to.

Further, when Example 1 and Examples 2 to 4 or Example 5 and Examples 6 to 8 are compared, a microreaction field is provided, and an appropriate shear force is applied to the reaction field, thereby using a stirrer. The average crystallite diameter (d ₅₀ ) of the metal compound crystallites was not different from the case of stirring with the metal compound, but the particle size distribution width (d ₉₀ / d ₅₀ ) was small and the metal compound in the colloidal solution It was confirmed that the average particle diameter (D ₅₀ ) of the fine particles was reduced.

When Example 5 and Example 9 are compared, in the case where a mixed solvent of water and a water-soluble solvent is used (Example 9) as compared with the case where only water is used as the solvent (Example 5), Although there was no difference in the average crystallite size (d ₅₀ ) and particle size distribution width (d ₉₀ / d ₅₀ ) of the metal compound crystallite, the average particle size (D ₅₀ ) of the metal compound fine particles in the colloidal solution was small. It was confirmed that Further, when Examples 8 and 10 to 11 are compared, as the polyalkyleneimine content increases, the average crystallite size (d ₅₀ ) and the particle size distribution width (d ₉₀ / d ₅₀ ) of the metal compound crystallites are different. However, it was confirmed that the average particle diameter (D ₅₀ ) of the metal compound fine particles in the colloidal solution was reduced.

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

  Therefore, the colloidal solution of the metal compound of the present invention is a nano-size highly dispersed dispersion of metal compound crystallites and aggregates thereof. Therefore, expression of a nano-size effect is expected in various applications, for example, heat resistance It is useful as a starting material for a catalyst carrier having an excellent balance between the surface area and 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 8, and the comparative example 9, and the particle size distribution (cumulative mass) of microparticles | fine-particles.

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)

The crystallite diameter d _{50 at} which the cumulative number in the particle size distribution is 50% is 0.8 to 3 nm, and the crystallite diameter d ₉₀ at which the cumulative number is 90% is 1.5 times or less of the crystallite diameter d _50. A colloidal solution containing crystallites of a metal compound and a polyalkylenimine having a weight average molecular weight of 3000 to 15000,
The colloidal solution has a pH of 1.0 to 6.0;
Particulates dispersed in said colloidal solution is cumulative mass particle diameter _{D 90} of the particle diameter at and cumulative mass is a particle diameter _{D 50} which is a 50% 0.8~70nm is 90% in the particle size distribution a crystallite and / or aggregates of the metal compound is 2.0 times the D _50, a colloidal solution of metal compounds, characterized in that. ^2. The colloidal solution of a metal compound according to claim 1, wherein the content of the polyalkyleneimine is 10 to 35 mg / m ² with respect to a unit surface area of the crystallite of the metal compound. 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 contains the polyalkyleneimine. Is what
3. The metal compound according to claim 1, wherein the metal compound is obtained by directly and independently introducing each of the raw material solutions into a region having a shear rate of 7500 sec ⁻¹ or less. 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 polyalkyleneimine. A colloidal solution of the metal compound according to claim 3.   5. 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 polyalkyleneimine further contains a neutralizing agent. A colloidal solution of the metal compound described in 1.   The colloidal solution of a metal compound according to any one of claims 3 to 5, wherein a cation concentration of the raw material solution containing the metal ions is 0.005 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 has a weight average molecular weight of 3000 to 3000. Containing 15000 polyalkylenimines,
Each of the raw material solutions is independently and directly mixed into a region where the shear rate is 7500 sec ⁻¹ or less, and the pH of the solution is adjusted to 1.0 to 6.0. A method for producing a 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 polyalkyleneimine. A method for producing a colloidal solution of the metal compound according to claim 7.   9. 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 polyalkyleneimine further contains a neutralizing agent. A method for producing a colloidal solution of a metal compound described in 1.   10. The metal compound colloidal solution according to claim 7, wherein a cation concentration of the raw material solution containing the metal ions is 0.005 to 0.5 mol / L. Production method.

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