Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G39/00—Compounds of molybdenum
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G39/00—Compounds of molybdenum
  • C01G39/02—Oxides; Hydroxides
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G41/00—Compounds of tungsten
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G41/00—Compounds of tungsten
  • C01G41/02—Oxides; Hydroxides
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/51—Particles with a specific particle size distribution
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/60—Particles characterised by their size
  • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/60—Particles characterised by their size
  • C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2006/00—Physical properties of inorganic compounds
  • C01P2006/80—Compositional purity

Definitions

• the present invention relates to a molybdic acid solution and its manufacturing method, molybdenum oxide powder and its manufacturing method.
• Molybdenum oxides such as molybdenum trioxide
• molybdenum trioxide are expected to find applications in the fields of electrochemical devices and displays, in addition to uses such as catalysts, pigments, and the production of ceramics and glasses.
• molybdenum trioxide when molybdenum trioxide is used as a catalyst, it is often used by coating the surface of a substrate or carrier. Research is being conducted to make it easier to add properties that match the application.
• Patent Document 1 A technique for making molybdenum trioxide into a solution is disclosed in Patent Document 1, for example.
• the present invention is to provide a molybdic acid solution with high concentration and excellent solution stability, a method for producing the same, and a molybdenum oxide powder and a method for producing the same.
• the molybdic acid solution of the present invention which has been made to solve the above problems, is a molybdic acid solution containing 0.1 to 40% by mass of molybdenum in terms of MoO 3 , and has a particle diameter of It is characterized by having a particle size (D50) of 20 nm or less by distribution measurement.
• the molybdic acid solution of the present invention preferably contains 0.1 to 40% by mass of molybdenum in terms of MoO 3 because the solution stability of the solution is improved. Further, the molybdic acid solution of the present invention more preferably contains 20 to 40% by mass of molybdenum in terms of MoO 3 .
• the molybdic acid concentration in the molybdic acid solution is obtained by diluting the solution with dilute hydrochloric acid as necessary, and using ICP emission spectrometry (Agilent Technologies: AG-5110) to calculate molybdenum oxide (MoO 3 ) conversion.
• MoO 3 molybdenum oxide
• the content of molybdic acid is shown in terms of MoO 3 based on the convention for showing molybdic acid concentration.
• molybdic acid in the molybdic acid solution of the present invention is presumed to exist in the solution as polymolybdic acid polynuclear complex ions in which molybdenum atoms and oxygen atoms undergo multistage condensation in the solution.
• the particle size (D50) measured by particle size distribution measurement using a dynamic light scattering method is preferably 20 nm or less from the viewpoint of stability over time, more preferably 10 nm or less, and even more preferably 2 nm or less. Particularly preferred is 1 nm or less, and even more preferably below the detection limit of less than 1 nm.
• the particle size (D50) of the present invention is determined by measuring the particle size distribution using a dynamic light scattering method. ”.
• the particle diameter (D50) of the molybdic acid particles in the molybdic acid solution of the present invention determined by particle size distribution measurement using a dynamic light scattering method is preferably 20 nm or less from the viewpoint of stability over time, and is preferably 10 nm or less. is more preferably 2 nm or less, particularly preferably 1 nm or less, and even more preferably less than the detection limit of less than 1 nm.
• the dynamic light scattering method measures the light scattering intensity from a group of particles moving in Brownian motion by irradiating a solution such as a suspension solution with light such as a laser beam.
• This is a method for determining the particle size and distribution.
• the particle size distribution evaluation method uses a zeta potential/particle size/molecular weight measurement system (manufactured by Otsuka Electronics Co., Ltd.: ELSZ-2000ZS), JIS Z 8828: 2019 "Particle size analysis-dynamic light scattering to comply with the law.
• the solution is filtered with a filter with a pore size of 2 ⁇ m, and ultrasonicated for 3 minutes with an ultrasonic cleaner (manufactured by AS ONE: VS-100III). Take action. Furthermore, the liquid temperature of the solution, which is the mode of measurement, was adjusted to 25°C.
• the particle diameter (D50) refers to the median diameter (D50), which is the particle diameter showing the 50% integrated value of the integrated distribution curve.
• the "solution" in the present invention is not limited to one in which a solute is dispersed or mixed in a solvent in a monomolecular state, but an assembly in which a plurality of molecules are attracted by intermolecular interactions, such as (1 ) polymeric molecules, (2) solvated molecules, (3) molecular clusters, (4) colloidal particles, etc., dispersed in a solvent.
• the molybdic acid solution of the present invention is preferably an aqueous solution.
• Molybdic acid in the molybdic acid solution of the present invention is highly dispersible in water and has good solubility in water, so that pure water can be used as a solvent.
• the molybdic acid solution of the present invention is characterized by containing ammonia and an organic nitrogen compound.
• the molybdic acid solution of the present invention contains ammonia and an organic nitrogen compound in addition to molybdic acid.
• the "ammonia” and “organic nitrogen compound” according to the present invention include those ionized in the molybdic acid solution of the present invention.
• a hydrous ammonium molybdate cake which is a molybdenum-containing precipitation slurry, is produced by a reverse neutralization method in which an acidic molybdenum solution is added to aqueous ammonia. It is believed that the substituted ammonia and organic nitrogen compound are present in the solution as cations since the molybdate solution of the present invention is produced by adding and mixing the organic nitrogen compound after formation.
• the method of measuring the concentration of ammonia present in the solution is to add sodium hydroxide to the solution to separate the ammonia by distillation, quantify the ammonia concentration with an ion meter, and heat conduction of N 2 minutes in the gasified sample.
• Examples include a method of quantifying with a gas meter, the Kjeldahl method, gas chromatography (GC), ion chromatography, gas chromatography/mass spectrometry (GC-MS), and the like.
• organic nitrogen compounds include aliphatic amines, aromatic amines, amino alcohols, amino acids, polyamines, quaternary ammonium, guanidine compounds, and azole compounds.
• aliphatic amines include methylamine, dimethylamine, trimethylamine, ethylamine, methylethylamine, diethylamine, triethylamine, methyldiethylamine, dimethylethylamine, n-propylamine, di-n-propylamine, tri-n-propylamine, iso- Propylamine, diiso-propylamine, triiso-propylamine, n-butylamine, di-n-butylamine, tri-n-butylamine, iso-butylamine, diiso-butylamine, triiso-butylamine and tert-butylamine, n-pentamine , n-hexylamine, cyclohexylamine, piperidine and the like.
• aromatic amines examples include aniline, phenylenediamine, and diaminotoluene.
• amino alcohols include, for example, methanolamine, ethanolamine, propanolamine, butanolamine, pentanolamine, dimethanolamine, diethanolamine, trimethanolamine, methylmethanolamine, methylethanolamine, methylpropanolamine, and methylbutanolamine.
• amino acids include, for example, alanine, arginine, aspartic acid, EDTA, and the like.
• polyamines include polyamines and polyetheramines.
• Examples of quaternary ammonium include alkylimidazolium, pyridinium, pyrrolidium, tetraalkylammonium and the like.
• alkylimidazolium include 1-methyl-3-methylimidazolium, 1-ethyl-3-methylimidazolium, 1-propyl-3-methylimidazolium, 1-butyl-3-methylimidazolium.
• pyridinium and pyrrolidium include N-butyl-pyridinium, N-ethyl-3-methyl-pyridinium, N-butyl-3-methyl-pyridinium, N-hexyl-4-(dimethylamino)-pyridinium, Examples include N-methyl-1-methylpyrrolidinium and N-butyl-1-methylpyrrolidinium.
• tetraalkylammonium include tetramethylammonium, tetraethylammonium, tetrabutylammonium, and ethyl-dimethyl-propylammonium.
• anions that form salts with the above cations include OH ⁇ , Cl ⁇ , Br ⁇ , I ⁇ , BF 4 ⁇ , HSO 4 ⁇ and the like.
• Guanidine compounds include guanidine, diphenylguanidine, and ditolylguanidine.
• azole compounds include imidazole compounds and triazole compounds.
• specific examples of imidazole compounds include imidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole and the like.
• Specific examples of triazole compounds include 1,2,4-triazole, methyl 1,2,4-triazole-3-carboxylate, and 1,2,3-benzotriazole.
• Methods for measuring the concentration of organic nitrogen compounds present in the solution include gas chromatography (GC), liquid chromatography (LC), mass spectrometry (MS), gas chromatography/mass spectrometry (GC-MS), and liquid chromatography. • Mass spectrometry (LC-MS) and the like may be mentioned, and a method of quantifying N 2 minutes in a gasified sample with a thermal conductivity meter may be used in combination.
• the organic nitrogen compound is preferably an aliphatic amine and/or a quaternary ammonium.
• these organic nitrogen compounds are volatile when compounded with multiple elements to add properties tailored to the application. This is because it is expensive and easy to remove.
• the organic nitrogen compound is an aliphatic amine, because it has particularly low toxicity.
• an aliphatic amine having 1 to 4 carbon atoms is more preferable, and an aliphatic amine having 1 to 2 carbon atoms is particularly preferable.
• Examples include methylamine and dimethylamine.
• the organic nitrogen compound is quaternary ammonium, it is preferable in terms of not only high solubility but also high crystallization suppression and high solation suppression.
• tetraalkylammonium salts are preferred, tetraalkylammonium hydroxide salts are more preferred, tetramethylammonium hydroxide, tetraethylammonium hydroxide are particularly preferred, and tetramethylammonium hydroxide (TMAH) is also particularly preferred.
• the organic nitrogen compound is not one selected from aliphatic amines, aromatic amines, amino alcohols, amino acids, polyamines, quaternary ammoniums, guanidine compounds and azole compounds, but a mixture of two or more.
• a mixture of two kinds, an aliphatic amine and a quaternary ammonium is preferable in that the solubility can be increased while suppressing the amount added so as not to increase toxicity.
• TMAH methylamine and tetramethylammonium hydroxide
• TMAH dimethylamine and tetramethylammonium hydroxide
• TMAH methylamine and dimethylamine
• TMAH methylamine and dimethylamine
• TMAH methylamine and dimethylamine
• the aliphatic amine is methylamine or dimethylamine
• the quaternary ammonium is more preferably tetramethylammonium hydroxide (TMAH).
• TMAH tetramethylammonium hydroxide
• TMAH tetramethylammonium hydroxide
• methylamine is particularly preferred because it has the highest volatility and the lowest toxicity.
• the molybdic acid solution of the present invention preferably has a pH of 6 or more and 12 or less. This is because when the molybdic acid solution of the present invention has a pH of 6 or more and 12 or less, the solution is more excellent in solution stability.
• the pH is more preferably 7 or more and 12 or less, more preferably 7 or more and 12 or less, particularly preferably 7 or more and 11 or less, and particularly preferably 9 or more and 10 or less.
• the molybdic acid solution of the present invention binds more strongly to the polymolybdic acid polynuclear complex ions as the basicity of the organic nitrogen compound contained in the solution increases, and H + in the polymolybdic acid polynuclear complex ions is liberated. It is presumed that the pH tends to decrease.
• the molybdic acid solution of the present invention contains, as additives, oxidation of Nb, Ta, Ti, Si, Zr, Zn, Al, Y, V, La (La, Ce, Nd, Eu, Gd, Dy, Yb). may contain powder. This is because the molybdic acid solution of the present invention is a homogeneous solution, and therefore, even if these oxide powders are in a suspended state, improvement in uniformity and improvement in reactivity (reaction rate) can be expected. Further, if these oxide powders are dissolved in the molybdic acid solution of the present invention to form a uniform solution, the composite element can be brought into a state of the highest reactivity.
• the molybdic acid solution of the present invention contains molybdenum, molybdic acid-derived components, and components other than ammonia and organic nitrogen compounds (referred to as "other components") within a range that does not impair its action and effect. may contain.
• Other components include, for example, Nb, Ta, Ti, Si, Zr, Zn, Al, Y, V, La-based (La, Ce, Nd, Eu, Gd, Dy, Yb). However, it is not limited to these.
• the content of other components in the molybdic acid solution of the present invention is preferably less than 5% by mass, more preferably less than 4% by mass, and even more preferably less than 3% by mass. It should be noted that the molybdic acid solution of the present invention is unintentionally assumed to contain unavoidable impurities.
• the content of unavoidable impurities is preferably less than 0.01% by mass.
• the molybdenum oxide powder of the present invention is characterized by containing molybdic acid particles contained in the molybdic acid solution.
• the molybdenum oxide powder of the present invention contains molybdic acid particles contained in the molybdic acid solution described above. A method for producing the molybdenum oxide powder of the present invention will be described later.
• the method for producing a molybdic acid solution of the present invention includes a step of adding an acidic molybdenum aqueous solution containing 1 to 100 g/L of molybdenum in terms of MoO 3 to a 10 to 30% by mass ammonia aqueous solution to produce a molybdenum-containing precipitate; and adding an organic nitrogen compound to the molybdenum-containing precipitation slurry obtained by making the molybdenum-containing precipitation into a slurry to generate a molybdic acid solution.
• the acidic molybdenum aqueous solution is such that molybdenum is converted to sulfuric acid.
• Molybdenum sulfate aqueous solution obtained by solvent extraction of a solution dissolved in an acidic aqueous solution containing molybdenum sulfate.
• Molybdenum referred to in this specification includes molybdenum oxide unless otherwise specified.
• the molybdenum sulfate aqueous solution is preferably adjusted to contain 1 to 100 g/L of molybdenum in terms of MoO 3 by adding water (for example, pure water).
• water for example, pure water
• the molybdenum concentration is 1 g / L or more in terms of MoO 3
• /L or more is more preferable.
• the molybdenum concentration is 100 g / L or less in terms of MoO 3 , it is preferable because it becomes a molybdate compound hydrate that is easily soluble in water.
• the pH of the molybdenum sulfate aqueous solution is preferably 2 or less, more preferably 1 or less, from the viewpoint of completely dissolving molybdenum or molybdenum oxide.
• the so-called reverse neutralization method adds the molybdenum sulfate aqueous solution to the ammonia aqueous solution of 10% by mass to 30% by mass, that is, by the reverse neutralization method, the molybdate compound hydrate. of the so-called molybdenum-containing precipitate is preferably obtained.
• the concentration of ammonia in the aqueous ammonia solution used for reverse neutralization is preferably 10% by mass to 30% by mass.
• concentration of ammonia in the aqueous ammonia solution used for reverse neutralization is preferably 10% by mass to 30% by mass.
• ammonia concentration is 10% by mass, molybdenum is less likely to remain undissolved, and molybdenum and molybdenum oxide can be completely dissolved in water.
• ammonia concentration is 30% by mass or less, it is close to a saturated aqueous solution of ammonia, which is preferable.
• the ammonia concentration of the aqueous ammonia solution is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, and particularly preferably 25% by mass.
• the ammonia concentration is preferably 30% by mass or less, more preferably 29% by mass or less, and even more preferably 28% by mass or less.
• the amount of the molybdenum sulfate aqueous solution added to the aqueous ammonia is preferably such that the molar ratio of NH 3 /MoO 3 is 0.1 or more and 300 or less, more preferably 5 or more and 200 or less.
• the molybdenum sulfate aqueous solution added to the ammonia water preferably has a NH 3 /SO 4 2- molar ratio of 3.0 or more, from the viewpoint of generating amines and molybdic acid compounds that dissolve in dilute ammonia water. 0.0 or more, and more preferably 20.0 or more.
• the molar ratio of NH 3 /SO 4 2- is preferably 200 or less, more preferably 150 or less, and even more preferably 100 or less.
• the time required for adding the molybdenum sulfate aqueous solution to the aqueous ammonia is preferably within 1 minute, more preferably within 30 seconds, and even more preferably within 10 seconds. That is, instead of gradually adding the molybdenum sulfate aqueous solution over time, it is preferable to add the aqueous solution of molybdenum sulfate to the ammonia water in as short a time as possible, for example, to carry out the neutralization reaction. Further, in reverse neutralization, since an acidic molybdenum sulfate aqueous solution is added to alkaline aqueous ammonia, the neutralization reaction can be carried out while maintaining a high pH. The molybdenum sulfate aqueous solution and the aqueous ammonia can be used at room temperature.
• the sulfur content is removed from the molybdenum-containing precipitate slurry obtained by the reverse neutralization method to produce a molybdenum-containing precipitate from which the sulfur content has been removed.
• the slurry of the molybdenum-containing precipitate obtained by the reverse neutralization method contains, as impurities, sulfate ions remaining unreacted with molybdenum or molybdenum oxide, and the sulfur content of hydrogen sulfate ions, so these are removed. is preferred.
• the sulfur removal method is arbitrary, but for example, a method by filtration using a membrane such as reverse osmosis filtration using ammonia water or pure water, ultrafiltration, or microfiltration, centrifugation, or other known methods. can be adopted.
• temperature control is not particularly required, and the removal may be carried out at room temperature.
• the slurry of the molybdenum-containing precipitate obtained by the reverse neutralization method is decanted using a centrifuge, and the slurry of the molybdenum-containing precipitate is washed until the electrical conductivity of the slurry is 500 ⁇ S/cm or less.
• a molybdenum-containing precipitate from which the sulfur content has been removed is obtained.
• the conductivity was measured by adjusting the liquid temperature of the slurry of the molybdenum-containing precipitate to 25 ° C., immersing the measurement part of a conductivity meter (manufactured by AS ONE: ASCON2) in the supernatant liquid of the slurry of the precipitate, and measuring the conductivity. After the value stabilized, the value was read.
• the molybdenum-containing precipitate slurry contains molybdenum from which the sulfur content has been removed as described above.
• the contained precipitate is diluted with pure water or the like to form a slurry.
• the molybdenum concentration of the molybdenum-containing precipitation slurry from which the sulfur content was removed was obtained by sampling a part of the slurry, drying it at 110 ° C. for 24 hours, and then calcining it at 1,000 ° C. for 4 hours to remove MoO 3 . Generate.
• the weight of MoO 3 thus produced can be measured and the molybdenum concentration of the slurry can be calculated from the weight.
• the molybdic acid solution of the present invention is obtained by mixing an organic nitrogen compound with the molybdenum-containing precipitation slurry from which the sulfur content has been removed.
• the obtained molybdenum-containing precipitation slurry is added to the organic nitrogen compound and mixed with pure water so that the molybdenum concentration of the final mixture is 0.1 to 40% by mass in terms of MoO 3 ,
• the liquid temperature is maintained at room temperature (25° C.) for 1 hour while stirring the mixture, a colorless and transparent molybdic acid solution of the present invention is obtained.
• the organic nitrogen compound mixed with the molybdenum-containing precipitation slurry is preferably an aliphatic amine and/or a quaternary ammonium.
• the aliphatic amine is preferably mixed so that the concentration of the aliphatic amine in the molybdenum-containing precipitation slurry is 40% by mass or less. From the same point of view, the concentration of aliphatic amine in the molybdenum-containing precipitation slurry is preferably 0.1% by mass or more, more preferably 20% by mass or more.
• the aliphatic amine is more preferably methylamine or dimethylamine, and particularly preferably methylamine.
• the quaternary ammonium is preferably mixed so that the concentration of the quaternary ammonium in the molybdenum-containing precipitation slurry is 40% by mass or less.
• the concentration of quaternary ammonium in the molybdenum-containing precipitation slurry is preferably 0.1% by mass or more, more preferably 20% by mass or more.
• the quaternary ammonium is more preferably tetramethylammonium hydroxide (TMAH).
• the organic nitrogen compound to be mixed with the molybdenum-containing precipitation slurry may be a mixture of two or more of the aliphatic amine and the quaternary ammonium instead of one.
• mixtures of two or more organic nitrogen compounds such as methylamine and tetramethylammonium hydroxide (TMAH), dimethylamine and tetramethylammonium hydroxide (TMAH), methylamine and dimethylamine, methylamine
• TMAH methylamine and tetramethylammonium hydroxide
• TMAH dimethylamine and tetramethylammonium hydroxide
• TMAH dimethylamine and tetramethylammonium hydroxide
• TMAH dimethylamine and tetramethylammonium hydroxide
• TMAH dimethylamine and tetramethylammonium hydroxide
• the method for producing molybdenum oxide powder of the present invention is characterized by having a step of drying and firing the molybdic acid solution obtained by the method for producing molybdenum acid solution of the present invention described above to produce molybdenum oxide powder.
• the molybdic acid solution obtained by the method for producing the molybdic acid solution of the present invention described above is placed in a stationary furnace and air-dried at a heating temperature of about 110 ° C. for 7 hours to obtain the molybdic acid solution of the present invention.
• a heating temperature of about 110 ° C. for 7 hours By evaporating the water, an intermediate product of molybdenum oxide powder containing the molybdenum oxide particles contained in the molybdic acid solution of the present invention is obtained.
• the molybdic acid solution may be placed in a vacuum drying furnace with an internal pressure of 0.01 MPa, heated to 60° C. or higher, and vacuum dried for 6 hours.
• the obtained intermediate product of molybdenum oxide powder (also referred to as dry powder) containing molybdenum oxide particles is placed in a stationary furnace, heated to 650° C. or higher, and fired for 1 to 3 hours. By doing so, a molybdenum oxide powder is obtained.
• the heating temperature is preferably 500° C. or higher and 2,000° C. or lower. When the heating temperature is 500° C. or higher and 2,000° C. or lower, the temperature is sufficient for the growth of molybdenum oxide particles, the firing cost can be suppressed, and the fired product obtained by firing becomes a hard lump. This is because there is no need for pulverization and an increase in cost can be avoided. Furthermore, the heating temperature is more preferably 700° C.
• the firing time is preferably 0.5 to 72 hours. This is because if the firing time is 0.5 to 72 hours, the time is sufficient for molybdenum oxide particles to grow, and unnecessary costs can be suppressed. Furthermore, the firing time is more preferably 0.5 hours to 50 hours, more preferably 0.5 hours to 30 hours.
• a pulverized fired product may be used as the molybdenum oxide powder.
• the under-sieves fine particle side obtained by classifying the fired product with a sieve or the like may be used as the molybdenum oxide powder.
• the sieve top coarse particle side
• a sieve when classifying using a sieve, it is preferable to use a sieve with an opening of 150 ⁇ m to 1,000 ⁇ m. When it is 150 ⁇ m to 1,000 ⁇ m, the proportion on the sieve does not become too large and re-pulverization is not repeated, and the molybdenum oxide powder that requires re-pulverization is not classified under the sieve.
• the composite molybdic acid composition of the present invention comprises the molybdic acid solution of the present invention described above, Si, Al, Ti, Zn, Sn, Y, Ce, Ba, Sr, P, S, La, Gd, Nd, and at least one element selected from the group consisting of Eu, Dy, Yb, Nb, Li, Na, K, Mg, Ca, Zr, W, and Ta.
• molybdic acid and at least one element selected from the group are present in the solution as ions in an ionic bond state.
• the composite molybdic acid composition of the present invention is not limited to the “solution” of the present invention, and includes those in which precipitates are formed in the “solution”.
• the molybdic acid concentration in the composite molybdic acid composition of the present invention is determined by moderately diluting the composition with dilute hydrochloric acid as necessary and using ICP emission spectrometry (manufactured by Agilent Technologies: AG-5110). MoO 3 It can be calculated by measuring the converted Mo weight fraction. Similarly to the Mo weight fraction, the concentration of at least one element selected from the group in the composite molybdic acid composition of the present invention can also be calculated.
• the method for producing a composite molybdic acid composition of the present invention comprises the molybdic acid solution produced by the method for producing a molybdic acid solution of the present invention described above, and Si, Al, Ti, Zn, Sn, Y, Ce, at least one element selected from the group consisting of Ba, Sr, P, S, La, Gd, Nd, Eu, Dy, Yb, Nb, Li, Na, K, Mg, Ca, Zr, W, and Ta and mixing to produce a composite molybdic acid composition.
• the liquid temperature is maintained at an appropriate temperature for a predetermined period of time to obtain the composite molybdenum of the present invention.
• An acid composition is obtained.
• at least one element selected from the group, which is mixed with the molybdic acid solution produced by the method for producing the molybdic acid solution of the present invention described above, is an oxidation It may be in various forms such as compounds, hydroxides, metal complexes and salts.
• the molybdic acid film of the present invention is characterized by containing molybdic acid particles contained in the molybdic acid solution.
• the molybdic acid film of the present invention ie, molybdic acid molded film, contains molybdic acid particles contained in the molybdic acid solution described above.
• the method for producing a molybdic acid film of the present invention is characterized by having a step of applying the molybdic acid solution obtained by the above-described method for producing a molybdic acid solution of the present invention and baking it to form a molybdic acid film.
• the molybdic acid solution obtained by the method for producing a molybdic acid solution of the present invention described above is dropped onto a substrate using a syringe while being filtered through a filter having a pore size of 2 ⁇ m, if necessary, followed by spinning. It was applied by coating (1,500 rpm, 30 seconds). Then, the substrate coated with the molybdic acid solution of the present invention is placed in a stationary furnace, heated to 700° C. or higher, and baked for 1 hour to obtain the molybdic acid film of the present invention.
• the composite molybdic acid film of the present invention is characterized by containing the composite molybdic acid particles contained in the composite molybdic acid composition.
• the composite molybdic acid film of the present invention that is, the composite molybdic acid molded film contains the composite molybdic acid particles contained in the composite molybdic acid solution described above.
• the method for producing a composite molybdic acid film of the present invention has a step of applying the composite molybdic acid composition obtained by the above-described method for producing a composite molybdic acid composition of the present invention and baking it to form a composite molybdic acid film. It is characterized by
• the composite molybdic acid composition obtained by the above-described method for producing a composite molybdic acid composition of the present invention is, if necessary, filtered through a filter having a pore size of 2 ⁇ m, for example, onto a substrate using a syringe. It was dropped and applied by spin coating (1,500 rpm, 30 seconds). Then, the substrate coated with the composite molybdic acid composition of the present invention is placed in a stationary furnace, heated to 700° C. or higher, and baked for 1 hour to form the composite molybdic acid film of the present invention. can get.
• the molybdic acid solution of the present invention may be added with a dispersant, a pH adjuster, a colorant, a thickener, a wetting agent, a binder resin, etc., depending on the application.
• this reaction liquid was decanted using a centrifuge and washed until the conductivity became 500 ⁇ S/cm or less to obtain a molybdenum-containing precipitate from which sulfur was removed. At this time, ammonia water was used as a cleaning liquid.
• the molybdenum-containing precipitation slurry diluted with pure water from which the sulfur content has been removed is mixed with 2% by mass of methylamine and pure water so that the molybdenum concentration of the final mixture is 10% by mass in terms of MoO3 .
• the mixture was stirred and kept at room temperature (25° C.) for 1 hour to obtain a colorless and transparent molybdic acid aqueous solution according to Example 1.
• the pH of the molybdic acid aqueous solution obtained in Example 1 was 9.7.
• Example 2 In Example 2, the production method was the same as in Example 1, except that 2% by mass of methylamine and pure water were mixed so that the molybdenum concentration of the final mixture was 0.1% by mass in terms of MoO3 . was carried out to obtain a colorless and transparent molybdic acid aqueous solution according to Example 2. The pH of the molybdic acid aqueous solution obtained in Example 2 was 9.4.
• Example 3 In Example 3, the same production method as in Example 1 was carried out, except that 2% by mass of methylamine and pure water were mixed so that the molybdenum concentration of the final mixture was 30% by mass in terms of MoO3 . Then, a colorless and transparent molybdic acid aqueous solution according to Example 3 was obtained. The pH of the molybdic acid aqueous solution obtained in Example 3 was 9.5.
• Example 4 In Example 4, the same production method as in Example 1 was carried out, except that 2% by mass of methylamine and pure water were mixed so that the molybdenum concentration of the final mixture was 40% by mass in terms of MoO3 . Then, a colorless and transparent molybdic acid aqueous solution according to Example 4 was obtained. The pH of the molybdic acid aqueous solution obtained in Example 4 was 9.0.
• Example 5 In Example 5, the same production method as in Example 1 was performed, except that 2% by mass of dimethylamine was mixed instead of 2% by mass of methylamine in the molybdenum-containing precipitation slurry diluted with pure water and from which sulfur was removed. A colorless and transparent molybdic acid aqueous solution according to Example 5 was obtained. The pH of the molybdic acid aqueous solution obtained in Example 5 was 6.7.
• Example 6 In Example 6, except that 2% by mass of tetramethylammonium hydroxide (TMAH) was mixed instead of 2% by mass of methylamine in the molybdenum-containing precipitation slurry diluted with pure water and from which sulfur was removed, Example 1 A colorless and transparent molybdic acid aqueous solution according to Example 6 was obtained by carrying out the same manufacturing method as . The pH of the molybdic acid aqueous solution obtained in Example 6 was 6.2.
• TMAH tetramethylammonium hydroxide
• Comparative example 1 In Comparative Example 1, the slurry of the molybdenum-containing precipitate described above was concentrated using an ultrafiltration device until the molybdenum concentration of the slurry was 10% by mass in terms of MoO 3 , and the conductivity was 500 ⁇ S / cm or less. A semi-transparent sol (suspension solution) was obtained by washing until the liquid became clear. Then, the mixture was stirred and kept at room temperature (25° C.) for 1 hour to obtain a translucent sol (suspension solution) molybdic acid aqueous solution according to Comparative Example 1. The obtained molybdic acid aqueous solution according to Comparative Example 1 had a pH of 6.9.
• Comparative example 2 In Comparative Example 2, the same production method as in Example 1 was performed, except that 22% by mass of methylamine was mixed instead of 2% by mass of methylamine in the molybdenum-containing precipitation slurry diluted with pure water and from which sulfur was removed. A translucent sol (suspension solution) molybdic acid aqueous solution according to Comparative Example 2 was obtained. The obtained molybdic acid aqueous solution according to Comparative Example 2 had a pH of 8.8.
• the particle size distribution was evaluated by a dynamic light scattering method according to JIS Z 8828:2019 using a zeta potential/particle size/molecular weight measurement system (manufactured by Otsuka Electronics Co., Ltd.: ELSZ-2000ZS). In addition, it was filtered through a filter with a pore size of 2 ⁇ m, and the above-mentioned dispersion treatment using ultrasonic waves was performed.
• the particle diameter (D50) refers to the median diameter (D50), which is the particle diameter showing the 50% integrated value of the cumulative distribution curve.
• Initial particle size D50 (nm) refers to the molybdic acid particle size (D50) in an aqueous molybdenum solution adjusted to a liquid temperature of 25°C immediately after being produced.
• time-dependent particle size D50 (nm) refers to the molybdic acid particle size (D50) in the molybdenum aqueous solution after standing for one month in a constant temperature chamber set at room temperature of 25°C.
• the molybdic acid aqueous solutions according to Examples 1 to 6 had excellent solution stability during long-term storage when the molybdic acid concentration in the aqueous solution was 0.1 to 40% by mass. .
• the molybdic acid aqueous solution according to Comparative Example 1 had precipitates after it was allowed to stand for one month under the test conditions of the above-described stability test over time. A precipitate was observed in the molybdic acid aqueous solution according to Comparative Example 2.
• the aqueous solutions of molybdic acid according to Examples 1 to 6 had improved solution stability when the pH of the aqueous solutions was 6 or more and 12 or less.
• the basicity increases in the order of methylamine, dimethylamine, and tetramethylammonium hydroxide (TMAH) contained in the aqueous solution, so as the basicity increases, polymolybdic acid It was presumed that the pH tended to decrease due to the strong binding with polynuclear complex ions and liberation of H + in the polymolybdic acid polynuclear complex ions.
• TMAH tetramethylammonium hydroxide
• Molybdic acid aqueous solutions according to Examples 1 to 6 are molybdic acid films formed from molybdic acid aqueous solutions according to all examples as a result of observing the coating films formed from these molybdic acid aqueous solutions at 100 times with an optical microscope. , no air bubbles, coating unevenness, or cracks were observed, and the film-forming properties were excellent.
• the molybdic acid aqueous solution according to the present invention has a high concentration and excellent solution stability, and is suitable as a coating agent or a composite material with multiple elements.
• INDUSTRIAL APPLICABILITY The aqueous molybdic acid solution according to the present invention can be produced with low energy consumption and is stable as a product, leading to sustainable management and efficient utilization of natural resources.

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