JPH0735253B2 - Zirconia or zirconia-based spherical particles and method for producing metal-supported zirconia or zirconia-based spherical particles - Google Patents

Description

TECHNICAL FIELD The present invention relates to zirconia spherical particles and a method for producing the same. Specifically, the present invention is submicron (about 1 μm or less)
TECHNICAL FIELD The present invention relates to monodisperse zirconia spherical particles having a narrow particle size distribution and capable of controlling the particle size from 10 to several tens of microns, and a method for producing the same. More specifically, the spherical particles have a high filling property and a slip property due to their shape characteristics, and are not only optimal as a raw material for a ceramic molded body but also useful as a coating agent, an abrasive or the like.

Further, in the present invention, it is possible to produce zirconia-based spherical particles containing a metal component other than zirconium, and further, because of the high dispersibility of the spherical particles, as a particle by coating the particle surface with another metal. It is easy to enhance the function of zirconia spherical particles or metal-coated or supported zirconia spherical particles having a composite composition as described above, such as catalyst, paste filler, conductive material, dispersion plating filler, and decorative material. It can be used in a wide range of fields.

[Prior Art] A method for producing spherical particles of zirconia or inorganic spherical particles has been disclosed by the present inventors in Japanese Patent Application Nos. 62-40085 and 62-62.
-170868 and Japanese Patent Application No. 63-40839. In these production methods, a metal oxide sol such as zirconia is prepared from an aqueous solution of an inorganic metal salt, and the sol is mixed with an organic solvent and a surfactant to form a w / o type emulsion,
This sol emulsion is formed into a gel emulsion, and the gel emulsion is dried and then baked to prepare inorganic spherical fine particles such as zirconia.

[Problems to be Solved by the Invention] In the above production method, since chlorides and nitrates of inorganic metals are used as starting materials for the sol, chlorine ions and nitrate ions are present in the obtained sol. Therefore, there is a problem that corrosion of the apparatus or a low temperature ignitable substance due to a reaction with an organic solvent and a surfactant is likely to be generated in a subsequent step, and handling becomes complicated. Therefore, it is necessary to sufficiently wash the sol by ultrafiltration or the like to remove chlorine ions and nitrate ions in the sol. In the case of industrially producing inorganic spherical fine particles such as zirconia for high purification, production It had a problem of poor sex.

[Means for Solving the Problems] As a result of intensive studies for solving the above problems, the present inventors have found that zirconium hydrate-containing sol (hereinafter, “zirconia”) manufactured by the manufacturing method specified in the claims. It is found that zirconia spherical particles can be obtained with high productivity, and that the obtained zirconia spherical particles have excellent characteristics by using (sol)). .

Therefore, the object of the present invention is to have substantially spherical zirconia spherical particles having excellent monodispersibility, and zirconia-based spherical particles containing a metal component other than zirconium, and their excellent industrial productivity economically. The present invention provides an advantageous manufacturing method. In the following, zirconia-based spherical particles are collectively referred to as zirconia spherical particles unless otherwise specified.

Another object of the present invention is to provide highly functionalized zirconia spherical particles and a method for producing the same.

The present invention will be described in detail below.

The present invention is prepared by heating and hydrolyzing a reaction product of zirconyl ammonium carbonate and a chelating agent at 60 ° C. or higher, the content of zirconium oxide is 5 to 40% by weight, and the pH is 5 to 10%. Zirconium hydrate-containing sol in the range of 0.05 to 30% by weight of a surfactant and 5 to 80% by weight of a water-insoluble or sparingly water-soluble organic solvent by stirring and mixing,
Forming an O-type emulsion, and then heating the emulsion to remove water in the spherical sol forming the aqueous phase of the emulsion as a mixture with the organic solvent to the outside of the system to form a spherical gel in the spherical sol, , The spherical gel
By removing organic substances such as surfactants by baking at 300 ° C or higher, the average particle size is in the range of 0.05 to 50 μm, the standard deviation is in the range of 1 to 1.5, and the specific surface area is 5 to 2
A method for producing spherical particles of zirconia having a particle size of 00 m ² / g.

The present invention also provides, in the above method, at least one compound selected from the group consisting of magnesium, calcium, aluminum, silicon, titanium, tin, yttrium, lanthanum, and cerium in the zirconium hydrate-containing sol, or two of these metal elements. The average particle diameter characterized by adding at least one kind of the composite compound containing the above
It is a method for producing zirconia-based spherical particles having a standard deviation value of 1 to 1.5 and a specific surface area of 5 to 200 m ² / g in the range of 0.05 to 50 μm.

Further, the present invention, the average particle size obtained by the above method is 0.
In the range of 05 to 50 μm, the standard deviation value is in the range of 1 to 1.5,
Zirconia spherical particles or zirconia-based spherical particles having a specific surface area of 5 to 200 m ² / g, at least one metal selected from the group consisting of ruthenium, rhodium, palladium, silver, indium, platinum and gold, and / or vanadium, Chromium, manganese, iron, cobalt, nickel, copper,
A method for producing metal-supported zirconia spherical particles or zirconia-based spherical particles, which comprises supporting at least one metal selected from the group consisting of molybdenum, tungsten and bismuth, or a metal oxide thereof.

In particular, the feature of the present invention is as a method for preparing a zirconia sol,
The reaction product of zirconyl ammonium carbonate and a chelating agent is hydrolyzed to obtain a high-concentration zirconia sol having a pH in the range of 5 to 10, and this zirconia sol is used as a raw material for zirconia spherical particles.

The method for producing the sol and the like will be described below.

That is, a zirconyl ammonium carbonate aqueous solution is put into a stirred tank reactor, and a chelating agent is added under stirring to obtain a reaction product of the zirconyl ammonium carbonate and the chelating agent at room temperature. Then, the aqueous solution containing the product is further heated to 60 ° C. or higher to hydrolyze the reaction product of zirconyl ammonium carbonate and the chelating agent. In this case, a gas mainly containing carbon dioxide and ammonia is generated, but the aqueous solution containing the product does not thicken and hydrolysis is completed while maintaining transparency. Of the liquid after the reaction
The pH is weakly alkaline to neutral and weakly acidic, and this reaction solution is preferably used as the zirconia sol of the present invention.

By adopting the above sol preparation method, ammonium ions and carbonate ions, which are impurities as a sol during the hydrolysis reaction, are discharged out of the system as ammonia and carbon dioxide, and thus the reaction between zirconyl ammonium carbonate and the chelating agent It is not necessary to wash the reaction liquid after the hydrolysis reaction of the product, and it can be used as it is as the zirconia sol of the present invention. Further, it is possible to increase the concentration by ordinary heating concentration, and it relates to a method for producing spherical particles of zirconia which is excellent in industrial productivity and economically advantageous.

Further, of course, a trace amount of unreacted material remaining in the reaction solution, ammonium ion, carbonate ion, etc. can be used for the production of the zirconia spherical particles of the present invention as a high-purity zirconia sol by washing with an ultrafiltration membrane. It is possible.

As the chelating agent used in the preparation of the zirconia sol used in the present invention, catechol, oxyphenols such as pyrogallol, amino alcohols such as diethanolamine and triethanolamine, glycolic acid, citric acid, tartaric acid, lactic acid, and mandel Oxy acids such as acid, malic acid, hydroxyacrylic acid and their methyl,
Esters such as ethyl and hydroxyethyl, oxyaldehydes such as glycolaldehyde, polycarboxylic acids such as oxalic acid and malonic acid, amino acids such as glycine and alanine, acetylacetone, benzoylacetone, stearoylacetone, stearoylbenzoylmethane, dibenzoyl One of β-diketones such as methane and β-ketone acids such as acetoacetic acid, propionylacetic acid, benzoylacetic acid and their esters such as methyl, ethyl, n-propyl, isopropyl, n-butyl and t-butyl, or Two or more kinds can be used in combination. Of these, oxyacids such as glycolic acid, citric acid, tartaric acid, lactic acid, mandelic acid, malic acid and hydroxyacrylic acid or β-diketones such as acetylacetone are preferably used. More preferably, α-, β- and γ-oxy acids are α-, β- and γ-ketonic acids or their esters each having a functional group having an oxygen atom on the α, β and γ carbon atoms. .

The amount of chelating agent used varies depending on the type of chelating agent used, but is 0.02 to 4 equivalents (molar ratio) to zirconium in zirconyl ammonium carbonate, preferably 0.
It is selected to be in the range of 1 to 3 equivalents (molar ratio), more preferably 0.5 to 2 equivalents (molar ratio). When the amount of the chelating agent used is less than 0.02 equivalent, the hydrolysis reaction of the reaction product between zirconyl ammonium carbonate and the chelating agent is insufficient and the zirconia sol is not sufficiently formed, so that it exceeds 4 equivalents (molar ratio). If no special effect is observed.

Furthermore, the hydrolysis reaction in the above method may be carried out by heating at 40 ° C. or higher, and it is also preferable to react in a pressurized atmosphere in order to accelerate the reaction. Practical reaction temperature is 60 ~ 20
It is 0 ° C.

According to the above method, the content of zirconium oxide is 5
It is possible to obtain a zirconia sol having a pH of ˜40% by weight and a pH of 5 to 10, but the sol concentration affects the spherical particle size,
For the production of spherical zirconia particles, it is preferable to use a zirconia sol having a concentration of 5 to 30% by weight.

Zirconia-based spherical particles containing a metal component other than zirconium can also be produced in the same manner as above, but in this case, the metal component other than zirconium need not be a sol as the form of the additive, but an acetate salt, a carbonate salt, It may be in the form of an aqueous solution such as a hydroxide or a slurry. As the metal component contained, magnesium, calcium, aluminum, silicon, titanium, tin and yttrium, and rare earth elements such as lanthanum and cerium are suitable.

Hereinafter, a method for producing the zirconia spherical particles will be described.

The sol concentration obtained according to the above manufacturing method is 5-40
After adding a water-insoluble or sparingly water-soluble organic solvent and a surfactant to the zirconia sol by weight%, emulsify by stirring and mixing using a normal stirring blade, a homogenizer, a colloid mill, an ultrasonic disperser, etc. Form an o-type emulsion.

In this case, the organic solvent used is benzene, toluene, aromatic hydrocarbons such as xylene, chlorobenzene,
Halogenated hydrocarbons such as dichlorobenzene, carbon tetrachloride, dichloromethane, trichloroethylene, heptane,
Aliphatic hydrocarbons such as octane, decane and dodecane, alicyclic hydrocarbons such as cyclohexane and cyclododecane,
Higher aliphatic alcohols such as hexanols, heptanols and octanols, and alicyclic alcohols such as cyclopentanol and cyclohexanol are preferably used. In addition, an amount of the water-soluble organic solvent that does not cause any inconvenience in the formation of the w / o type emulsion can be mixed.

Further, as the surfactant used, known ones can be used as long as they can cause w / o emulsification, but in order to avoid mixing of metal ions contained in the surfactant, nonionic surfactants Is preferably used. Examples of nonionic surfactants include polyoxyethylene alkyl ether type, polyoxyethylene alkylaryl ether type, polyoxyethylene alkylamine type, polyoxyethylene alkylamide type, polyoxyethylene sorbitan fatty acid ester type, pluronic type, and TE type. There are polyalkylene glycol type such as tronic type and polyhydric alcohol type. Further, at this time, as an emulsion stabilizer, amino acids such as glycine, alanine, phenylalanine, valine, leucine, isoleucine, lysine, serine, aspartic acid, glutamic acid, methionine, arginine or salts thereof, sorbitol, glycerin and the like. A stable emulsion can be obtained by using polyhydric alcohols. The amount used is 0.05 to 30% by weight, preferably 0.1 to 5% by weight, based on the sol used.

Depending on the raw material sol concentration used, the type of organic solvent and the amount ratio with the aqueous layer, the type and concentration of the surfactant, the method of mechanical emulsification when preparing the w / o type emulsion, the temperature during emulsification, etc. The difference in particle size and stability is the same as in the case of a usual emulsification method. There is a direct correlation between the particle size of the emulsion and the particle size of the obtained spherical particles, and the particle size of the spherical particles is determined by the particle size of this emulsion and the concentration of the raw material sol.

Therefore, preparing a w / o type emulsion having a narrow particle size distribution produces monodispersed zirconia spherical particles having a narrow particle size distribution. For this purpose, a water-insoluble or poorly water-soluble organic solvent is contained in an amount of 5 to 80% by weight, preferably 10 to
60 wt%, more preferably in the range of 30 to 50 wt%, the sol concentration (content as zirconium oxide in the sol) is 5 to
20% to 95% by weight of zirconia sol, which is 40% by weight, preferably 40 to 90% by weight, more preferably 50 to 70% by weight, and 0.1 to 30% by weight, preferably 1 to 10% by weight of a surfactant. More preferably, the mixture is stirred and mixed in the range of 1 to 5% by weight and emulsified in the range of 10 to 90 ° C, preferably 40 to 80 ° C to produce a w / o type emulsion having a narrow particle size distribution.

Then, the w / o type emulsion is heated to remove the water in the spherical sol forming the aqueous layer of the emulsion as a mixture with the organic solvent out of the system, and at the same time, the spherical sol is made into a spherical gel. The heating of the emulsion may be in the range of 10 to 120 ° C. under normal pressure, but the water in the spherical sol is immediately dehydrated,
At the same time, heating under reduced pressure is preferable for gelling the spherical sol, and the temperature at this time is 0 to 100 ° C., preferably 10 to 7
It is in the range of 0 ° C.

The spherical gel particles thus obtained contain an organic substance such as a surfactant, and by firing this, dehydration and crystallization of the gel and burning of the organic substance such as a surfactant are carried out. In this case, the gel is dehydrated and crystallized while maintaining the spherical shape, and monodispersed zirconia spherical particles having a narrow particle size distribution in the range of 0.05 to 50 μm, especially the standard deviation of 1 to 1.5 are produced. .

The firing may be performed at 300 ° C. or higher at which the surfactant decomposes, but by firing at 600 ° C. or higher, high-strength zirconia spherical particles can be obtained. Since a gas accompanied by a foul odor is generated when the surfactant is decomposed by firing, it is preferable to perform the heating in a tubular kiln rotary kiln with a rotating furnace wall capable of continuous firing type zone heating.

Zirconia spherical particles thus obtained and magnesium, calcium, aluminum, silicon, titanium,
The zirconia-based spherical particles containing a metal component other than zirconium such as tin and yttrium, rare earth elements such as lanthanum and cerium, have an average particle size in the range of 0.05 to 50 μm.
Its standard deviation is in the range of 1-1.5, specific surface area is 5-200 m ² / g
It has the following characteristics. Further, the true density of each particle is 4 g / cm ³ or more, although it varies depending on the type of additive element, firing temperature and the like.

The average particle diameter and standard deviation value referred to in the present invention were determined by the following methods.

The particle diameter of 100 arbitrary particles in an electron micrograph image of 100,000 times was measured and determined, and the average particle diameter and standard deviation were calculated by the following formulas.

(However, Xi represents the i-th particle diameter and n is 100.) Such zirconia spherical fine particles and zirconia-based spherical particles having excellent dispersibility and a high specific surface area can be formed on the surface or inside of the particles. By supporting a metal or a metal oxide or both, the function as particles can be enhanced. The supported metal or metal oxide is at least one metal selected from the group consisting of ruthenium, rhodium, palladium, silver, indium, platinum and gold and / or vanadium, chromium, manganese, iron, cobalt, nickel, copper. ,
At least one metal selected from the group consisting of molybdenum, tungsten, and bismuth or a metal oxide thereof is selected, and the supporting method depends on the application, impregnation with an aqueous solution of the above metal compound, vapor deposition of the above metal or metal compound. A method such as sputtering, ion plating, plasma spraying, plating of the above-mentioned metals, particularly electroless plating is appropriately selected.

Zirconia spherical fine particles carrying these metals or metal oxides or mixtures thereof are for catalysts, for decoration,
It is preferably used as a conductive material for a particle dispersion-reinforced composite material, a conductive paste, and the like. Especially for catalysts, 1) catalysts for combustion of hydrocarbons and carbon monoxide such as methane, ethane, propane, butane, kerosene, and organic solvents, 2) nitrogen oxides (NOx), sulfur oxides (SOx) ozone (O) ₃ ) Combustion or decomposition catalysts such as ₃ ) Catalysts for organic acid synthesis processes such as phthalic acid, maleic acid, acrylic acid, methacrylic acid, etc. 4) Hydrocarbons are contacted with steam at a temperature of 400-1500 ° C to produce hydrogen. And a steam reforming catalyst for producing a gas composed of carbon monoxide, and the like.

[Examples] Hereinafter, the present invention will be described in more detail with reference to Examples, Reference Examples, and Comparative Examples, but is not limited to these Examples and the like.

Reference Example 1 13 kg of an aqueous zirconyl ammonium carbonate solution containing 13% by weight of zirconium oxide was placed in a stirred tank reactor having a capacity of 10 liters, and 1 kg of glycolic acid was gradually added with stirring. At this time, odorless gas is generated. Then
The hydrolysis reaction was performed while heating the reactor with a mantle heater. When the temperature of the reaction solution reaches 50 to 60 ° C., a gas with an ammonia odor begins to be generated, and as the temperature further rises, it foams violently, and a gas mainly containing carbon dioxide and ammonia is generated. After discharging these gases to the outside of the system, the temperature was raised to 100 ° C. and maintained for 3 hours. While adding pure water into the reactor, the temperature was further maintained at 100 ° C. for 12 hours to complete the hydrolysis reaction. After cooling the reaction solution to room temperature, the concentration was adjusted while adding pure water to obtain a transparent zirconia sol containing 35% by weight of zirconium oxide and having a pH of 7. The sol was stable for a long period of time.

Reference Example 2 Yttrium acetate was added to a transparent zirconia sol containing 30% by weight of zirconium oxide prepared by the same method as in Reference Example 1 and having a pH of 7, and 5.3% by weight of yttrium oxide was used with respect to zirconium oxide in the sol. To 30% by weight as zirconium oxide and 5.3% by weight as yttrium oxide.
A transparent zirconia sol of No. 6 was obtained. The sol was stable for a long period of time.

Reference Example 3 Yttrium acetate was contained in a transparent zirconia sol containing 30% by weight of zirconium oxide prepared by the same method as in Reference Example 1 and having a pH of 7.2% by weight of yttrium oxide based on zirconium oxide in the sol. PH that contains 30% by weight of zirconium oxide and 14.2% by weight of yttrium oxide, which have been added to
A transparent zirconia-based sol of 5.5 was obtained. The sol was stable for a long period of time.

Reference Example 4 As a zirconium oxide prepared by the same method as in Reference Example 1, containing 30% by weight, transparent zirconia sol having a pH of 7 and cerium acetate 5.3% by weight of cerium oxide to zirconium oxide in the sol. To give a transparent zirconia-based sol having a pH of 8 and containing 30% by weight of zirconium oxide and 5.3% by weight of cerium oxide. The gel was stable for a long time.

Example 1 Polyalkylene glycol having a HLB of about 5 as a surfactant
While circulating 30 kg of octanol in which 0.9 kg was dissolved in a colloid mill, 1 kg of the zirconia sol obtained in Reference Example 1 was added.
It was put into a colloid mill at a ratio of min to form a sol emulsion.

Next, the sol emulsion was transferred to an agitated vibrating fluidized dryer equipped with a water jacket, the interior of the dryer was depressurized by a water flow pump, and then steam was introduced into the jacket to heat the sol emulsion while stirring. . When the sol emulsion shows almost no fluidity, the dryer is vibrated to dry, then steam is stopped and heating is stopped, and when the temperature inside the dryer becomes 60 ° C or lower, the inside pressure is returned to atmospheric pressure. Spherical gel particles containing an organic substance were obtained.

Next, the organic substance-containing spherical gel particles are put into a rotary kiln heated to 600 ° C. to remove organic substances such as surfactants adhering to the spherical gel particles by firing, and the average particle size is 0.
Spherical zirconia particles having a particle size of 3 μm and a specific surface area of 50 m ² / g were obtained. Its standard deviation was 1.18.

Example 2 Zirconia spherical particles having an average particle size of 2 μm and a specific surface area of 25 m ² / g were obtained in the same manner as in Example 1 except that polyalkylene glycol having an HLB of about 11 was used as the surfactant. Its standard deviation was 1.32.

Example 3 HLB about 5 polyalkylene glycol as a surfactant
While circulating 30 kg of octanol in which 0.6 kg of polyalkylene glycol (0.6 kg of HLB is about 11) was circulated in the colloid mill, the zirconia sol obtained in Reference Example 2 was charged into the colloid mill at a rate of 1 kg / min to obtain a sol emulsion. Was formed. Thereafter, in the same manner as in Example 1, the average particle size was 0.
3 mol of yttrium oxide with 5 μm and specific surface area of 100 m ² / g
% Zirconia spherical particles were obtained. Its standard deviation is 1.12
Met.

Example 4 Polyalkylene glycol having a HLB of about 5 as a surfactant
An average particle size of 2. was obtained in the same manner as in Example 1 except that 0.8 kg and 0.3 kg of polyalkylene glycol having an HLB of about 11 were used.
3 mol of yttrium oxide with 5 μm and specific surface area of 70 m ² / g
% Zirconia spherical particles were obtained. Its standard deviation is 1.28
Met.

Example 5 HLB about 5 polyalkylene glycol which is a surfactant
An average particle size of 2. was obtained in the same manner as in Example 1 except that 0.9 kg and 0.9 kg of polyalkylene glycol having an HLB of about 11 were used.
8 mol of yttrium oxide with 0 μm and specific surface area of 120 m ² / g
% Zirconia spherical particles were obtained. Its standard deviation is 1.2
Met.

Example 6 Surfactant HLB about 5 polyalkylene glycol
While circulating 30 kg of octanol in which 0.6 kg of polyalkylene glycol 0.6 kg of HLB about 11 was circulated in the colloid mill, the zirconia sol obtained in Reference Example 4 was charged into the colloid mill at a rate of 1 kg / min to obtain a sol emulsion. Was formed. Thereafter, in the same manner as in Example 1, the average particle size was 0.
Spherical particles of zirconia containing 3 mol% of cerium oxide having a particle size of 5 μm and a specific surface area of 70 m ² / g were obtained. Its standard deviation was 1.27.

Example 7 The average particle size obtained in Example 5 was 2.0 μm and the specific surface area was 120 m ^2.
/ g yttrium oxide 8mol% added zirconia spherical particles were sensitized at room temperature for 2 minutes using stannous chloride solution (SnCl ₂ · 2H ₂ O 158g / l), washed with water and then palladium chloride solution (PdCl ₂ 0.2 g / l), and activated at 40 ° C. for 3 minutes and washed with water. After repeating the above sensitizing and activation again, 8 mol of the yttrium oxide was added to a palladium plating solution (A-10X, Uemura Kogyo Co., Ltd.).
% Zirconia spherical particles were added and stirred at room temperature for 5 minutes, then washed with a microfilter, added to a reducing agent (BEL-801R, Uemura Kogyo Co., Ltd.), stirred at room temperature for 5 minutes, and further microfiltered. It was washed with water and dried to obtain spherical zirconia particles coated with palladium.

Example 8 Palladium-coated zirconia spherical particles obtained in Example 7 were mixed with 80
The mixture is added to a rhodium plating solution (Rh-1 of Okuno Seiyaku Co., Ltd.) at ℃ and stirred for 5 minutes at the same temperature, and then heating is stopped and cooled to room temperature. It was washed with a microfilter and dried to obtain rhodium-coated zirconia spherical particles.

Example 9 The average particle size obtained in Example 1 is 0.3 μm, and the specific surface area is 50 m ² /
A chloroplatinic acid solution was added to 300 g of spherical zirconia spherical particles (g) and immersed therein, and then dried at 150 ° C. This was crushed in a mortar and then baked at 950 ° C. for 5 hours to obtain platinum-supported zirconia spherical particles in which 1 g of platinum was supported on 100 g of zirconium oxide.

Example 10 The average particle size obtained in Example 6 was 0.5 μm, and the specific surface area was 70 m ² / g.
Zirconia Spherical Particles with Addition of Cerium Oxide 30mol% 300
Cobalt nitrate, lanthanum nitrate, and strontium nitrate mixed solution cobalt was added to g, and the mixture was dipped and dried at 150 ° C. This was ground in a mortar, La ₀ against the zirconium oxide 100g and calcined 3 hours at _{920 ℃. 8 Sr 0. La} 0 carrying Sg as ₂ O ₃ becomes a perovskite-type composite oxide. ₈ S
It was obtained r _{0. 2} O ₃ supported zirconia spherical particles.

Test Example 1 Palladium-coated zirconia spherical particles obtained in Example 7 were made into a paste and screen-printed on an alumina substrate, and then 900 ° C.
The Pd thick film circuit was formed by firing for 30 minutes. As a result of performing a solder crack test using this circuit, solder nicks after the solder immersion test was performed 10 times were hardly observed, and it was effectively used as a conductive paste.

Test Example 2 80 g of activated alumina having a specific surface area of 100 m ² / g and containing 20 g of rhodium-coated zirconia spherical particles obtained in Example 8 and 1 g of platinum
A slurry for coating was prepared by wet-milling and with a ball mill for 20 hours. A cordierite monolith carrier with an outer diameter of 25.4 mmφ and a length of 500 ml having a cross-sectional area of about 400 gas flow cells per square inch was immersed in this slurry, and the excess slurry in the cell was extracted with compressed air after removal. It was blown to remove the clogging in the cell. Then
It was dried at 130 ° C. for 3 hours to obtain a finished catalyst. The catalyst was aged in air at 900 ° C for 10 hours in an electric furnace, and then an air-fuel ratio was set to A / F = 1 using an electronically controlled engine (four-cylinder 1800cc).
It was fixed at 4.6 and the purification performance of carbon monoxide, hydrocarbons and nitric oxide was measured. As a result of evaluating the catalyst performance by obtaining the catalyst inlet gas temperature showing a purification rate of 50%, the carbon monoxide purification temperature was 390 ° C, the hydrocarbon purification temperature was 396 ° C, and the nitric oxide purification temperature was 388 ° C. The results are shown and it was effectively used as an exhaust gas purifying catalyst.

Test Example 3 A platinum-supported zirconia spherical particle obtained in Example 9 and 80 g of activated alumina having a specific surface area of 100 m ² / g were wet-milled for 20 hours with a ball mill to prepare a coating slurry. Then, a completed catalyst was obtained in the same manner as in Test Example 2.

This catalyst was installed in a flow reactor and carbon monoxide was 200ppm.
(Air balance) gas as reaction gas (SV = 20000Hr ^-1 )
As a result, the catalyst performance was evaluated by measuring the CO concentration on the catalyst inlet side and the CO concentration on the catalyst outlet side at a catalyst inlet gas temperature of 300 ° C.
Furthermore, the same measurement was performed after the catalyst was aged in an electric furnace at 900 ° C. for 10 hours in the air.

As a result, the CO conversion was 99% with the fresh catalyst, and the CO conversion was 87% after aging, which was a good result.

La ₀ obtained in Test Example 4 Example _{10. 8 Sr 0. 2 O} 3 supported zirconia spherical particles 60
Zirconia sol with g of 5% by weight zirconium oxide and pH 7
It is dispersed in 300 g, has an average fiber diameter of about 3 μm, a specific surface area of 135 m ² / g, an average pore size of 20 A, and a γ-alumina type alumina fiber laminate consisting of 5% by weight of silica and 95% by weight of alumina (10 cm in length, After immersing 12.5 cm in width and 2 cm in thickness) into the sol, it was dried at 120 ° C. and calcined at 600 ° C. to obtain a completed catalyst body.

1.5Kcal / cm ² · H by mounting this on a surface diffusion type catalytic combustor
Propane gas corresponding to r was supplied to the catalyst body and ignited by a heater.

As a result, the catalyst surface temperature is maintained at 440 to 520 ℃ in the central part and 240 to 350 ℃ in the peripheral part, and the exhaust gas composition is also carbon monoxide ~
4ppm, unburned propane was 30-500ppm, and combustion efficiency was 99.5%.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B01J 2/08 23/40 ZAB A 8017-4G 23/54 ZAB A 8017-4G (72) Inventor Teruyuki Moto 1 992 Nishi-oki, Okihama, Aboshi-ku, Himeji-shi, Hyogo Pref. Toshiko Nakata, Inspector, Catalysis Laboratory, Nippon Catalysis Chemical Co., Ltd. (56) Reference JP-A-1-126229 (JP, A)

Claims (4)

[Claims] 1. The content of zirconium oxide prepared by heating and hydrolyzing a reaction product of zirconyl ammonium carbonate and a chelating agent at 60 ° C. or higher is 5 to 40% by weight.
And a zirconium hydrate-containing sol having a pH in the range of 5 to 10 by stirring and mixing with a surfactant of 0.05 to 30% by weight and a water-insoluble or poorly water-soluble organic solvent of 5 to 80% by weight,
A spherical sol is formed into a spherical gel by forming a W / O type emulsion and then heating the emulsion to remove the water in the spherical sol forming the aqueous phase of the emulsion as a mixture with the organic solvent out of the system. Furthermore, the average particle size of the spherical gel is obtained by removing organic substances such as a surfactant by baking the spherical gel at 300 ° C. or higher, and the standard deviation value is in the range of 1 to 1.5 and the specific surface area is in the range of 0.05 to 50 μm. Is 5
A method for producing spherical particles of zirconia having a particle size of about 200 m ² / g. 2. The content of zirconium oxide prepared by heating and hydrolyzing a reaction product of zirconyl ammonium carbonate and a chelating agent at 60 ° C. or higher is 5 to 40% by weight.
And a zirconium hydrate-containing sol having a pH in the range of 5 to 10 at least one compound containing magnesium, calcium, aluminum, silicon, titanium, tin, yttrium, lanthanum, and cerium, or a metal element of these. After adding at least one compound compound containing two or more kinds, the mixture is stirred and mixed with 0.05 to 30% by weight of a surfactant and 5 to 80% by weight of a water-insoluble or sparingly water-soluble organic solvent to form a W / O type emulsion. The spherical sol is formed into a spherical gel by removing the water in the spherical sol that forms the aqueous phase of the emulsion from the system as a mixture with the organic solvent to form a spherical gel.
The average particle diameter obtained by removing organic substances such as a surfactant by baking the spherical gel at 300 ° C. or higher is 0.05.
A method for producing zirconia-based spherical particles having a standard deviation value of 1 to 1.5 and a specific surface area of 5 to ²⁰ m ² / g in the range of ˜50 μm. 3. A zirconia spherical particle obtained by the method according to claim 1, which has an average particle size of 0.05 to 50 μm, a standard deviation value of 1 to 1.5 and a specific surface area of 5 to 200 m ² / g. At least one selected from the group consisting of ruthenium, rhodium, palladium, silver, indium, platinum and gold
One metal and / or at least one metal selected from the group consisting of vanadium, chromium, manganese, iron, cobalt, nickel, copper, molybdenum, tungsten and bismuth, or a metal oxide thereof. A method for producing metal-supported zirconia spherical particles. 4. A zirconia-based spherical particle having an average particle size of 0.05 to 50 μm, a standard deviation value of 1 to 1.5, and a specific surface area of 5 to 200 m ² / g, which is obtained by the method according to claim 2. At least one selected from the group consisting of ruthenium, rhodium, palladium, silver, indium, platinum and gold.
One metal and / or at least one metal selected from the group consisting of vanadium, chromium, manganese, iron, cobalt, nickel, copper, molybdenum, tungsten and bismuth, or a metal oxide thereof. A method for producing spherical zirconia particles supported on a metal.