WO2017056613A1 - Method for producing vanadium dioxide particles - Google Patents

Method for producing vanadium dioxide particles Download PDF

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Publication number
WO2017056613A1
WO2017056613A1 PCT/JP2016/069700 JP2016069700W WO2017056613A1 WO 2017056613 A1 WO2017056613 A1 WO 2017056613A1 JP 2016069700 W JP2016069700 W JP 2016069700W WO 2017056613 A1 WO2017056613 A1 WO 2017056613A1
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Prior art keywords
vanadium dioxide
dioxide particles
vanadium
particles
hydrothermal reaction
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PCT/JP2016/069700
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French (fr)
Japanese (ja)
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啓司 新井
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コニカミノルタ株式会社
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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G31/00—Compounds of vanadium
    • C01G31/02—Oxides
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K9/00—Tenebrescent materials, i.e. materials for which the range of wavelengths for energy absorption is changed as a result of excitation by some form of energy

Definitions

  • the present invention relates to a method for producing vanadium dioxide particles. More specifically, the present invention relates to a method for producing vanadium dioxide particles exhibiting excellent thermochromic properties.
  • thermochromic material a material having thermochromic properties
  • thermochromic material is a material whose optical properties such as transparent state / reflective state change depending on temperature. Specifically, the material is in a reflective state when the temperature is high, and is in a transparent state when the temperature is low. When such a thermochromic material is applied to a window glass of a building, for example, it can reflect sunlight in the summer to block heat, and in winter it can transmit sunlight and use heat, As a result, both energy saving and comfort can be achieved.
  • thermochromic materials that has received most attention is vanadium dioxide particles containing vanadium dioxide (VO 2 ) (hereinafter also simply referred to as “VO 2 particles”).
  • VO 2 particles are known to exhibit thermochromic properties (property of reversibly changing optical characteristics depending on temperature) during phase transition near room temperature. Therefore, thermochromic properties depending on the temperature of the environment can be obtained by utilizing this property.
  • vanadium oxide has a plurality of polymorphs of oxides and crystal phases of trivalent to pentavalent vanadium.
  • crystal phases such as A phase, B phase, C phase and R phase (so-called “rutile crystal phase”).
  • R phase the main crystal structure exhibiting thermochromic properties as described above. Since this R phase has a monoclinic structure below the transition temperature, it is also called an M phase.
  • M phase the monoclinic structure below the transition temperature
  • the particles are not aggregated, the particle size is nano-order (100 nm or less), and the particles are isotropic. It is desirable to have
  • thermochromic member such as a film
  • a VO 2 particle or a dispersion thereof is prepared and bonded to a member that is desired to exhibit thermochromic properties via an adhesive. It has been studied to manufacture a member having chromic properties (see, for example, Patent Document 1 and Patent Document 2).
  • the VO 2 particles described in Patent Document 1 are produced by a hydrothermal reaction.
  • the particles grow anisotropically into a rod shape, the particle size is large and good thermochromic properties are obtained. There is a problem that can not be.
  • hydrazine is used as a reducing agent to reduce the particle size.
  • the particles are aggregated during the growth process, it is difficult to control the particle size and thermochromic property. is there.
  • the present invention has been made in view of the above-mentioned problems and situations, and the problem to be solved is to provide a method for producing vanadium dioxide particles exhibiting excellent thermochromic properties.
  • the present inventor formed vanadium dioxide particles by hydrothermal reaction in the process of studying the cause of the above problems, etc., and oxidized the vanadium dioxide particles, thereby providing excellent thermochromic properties.
  • the inventors have found that vanadium dioxide particles exhibiting the following can be produced, and have reached the present invention. That is, the said subject which concerns on this invention is solved by the following means.
  • a method for producing vanadium dioxide particles containing vanadium dioxide having thermochromic properties A step of forming the vanadium dioxide particles by hydrothermal reaction of a reaction solution containing a raw material containing a vanadium compound, a reducing agent and water; Oxidizing the vanadium dioxide particles;
  • a method for producing vanadium dioxide particles comprising:
  • Item 4 The method for producing vanadium dioxide particles according to any one of Items 1 to 3, wherein a temperature of the hydrothermal reaction is in a range of 250 to 350 ° C.
  • the vanadium dioxide particles are tungsten (W), molybdenum (Mo), niobium (Nb), tantalum (Ta), tin (Sn), rhenium (Re), iridium (Ir), osmium (Os), antimony (Sb).
  • the method for producing vanadium dioxide particles according to any one of items 1 to 5, wherein:
  • the above-mentioned means of the present invention can provide a method for producing vanadium dioxide particles exhibiting excellent thermochromic properties.
  • thermochromic property is improved.
  • the method for producing vanadium dioxide particles according to the present invention is a method for producing vanadium dioxide particles containing vanadium dioxide having thermochromic properties, and a hydrothermal reaction of a reaction solution containing a raw material containing a vanadium compound, a reducing agent and water. And the step of forming the vanadium dioxide particles and the step of oxidizing the vanadium dioxide particles.
  • This feature is a technical feature common to or corresponding to the claimed invention.
  • the pH at 25 ° C. of the reaction solution after the hydrothermal reaction is within the range of 4.0 to 7.0. This is preferable because the stability of the vanadium dioxide particles is improved.
  • the oxidation-reduction potential at 25 ° C. of the reaction solution after the hydrothermal reaction is in the range of 100 to 500 mV because the surface oxidation of the particles can be appropriately advanced.
  • the temperature of the hydrothermal reaction when the temperature of the hydrothermal reaction is in the range of 250 to 350 ° C., metastable rod-like vanadium dioxide particles that are impurities are less likely to be produced, and vanadium dioxide exhibiting an M phase. It is preferable because the particles are small and have a uniform size.
  • reaction time of the hydrothermal reaction is preferably within the range of 12 to 72 hours.
  • the vanadium dioxide particles are tungsten (W), molybdenum (Mo), niobium (Nb), tantalum (Ta), tin (Sn), rhenium (Re), iridium (Ir), osmium (Os). ), Antimony (Sb), ruthenium (Ru), germanium (Ge), chromium (Cr), iron (Fe), gallium (Ga), aluminum (Al), fluorine (F) and phosphorus (P). It is preferable in that the phase transition temperature can be changed by containing the selected element.
  • pH in 25 degreeC conversion means the value of pH at the time of measuring pH of a measuring object (in this invention, it is a reaction liquid mainly) at 25 degreeC.
  • the method for producing vanadium dioxide particles according to the present invention is a method for producing vanadium dioxide particles containing vanadium dioxide having thermochromic properties, and a hydrothermal reaction of a reaction solution containing a raw material containing a vanadium compound, a reducing agent and water. And the step of forming the vanadium dioxide particles and the step of oxidizing the vanadium dioxide particles.
  • vanadium dioxide particles containing vanadium dioxide having thermochromic properties of the present invention VO 2 (hereinafter, also referred to as "VO 2 particles”.
  • a reaction solution is prepared by mixing a solution containing a reducing agent, water, and a compound containing vanadium (V) (hereinafter also referred to as “vanadium compound”).
  • This reaction solution may be an aqueous solution in which the vanadium compound is dissolved in water, or may be a suspension in which the vanadium compound is dispersed in water.
  • the pH of the reaction solution after hydrothermal reaction is preferably in the range of 4.0 to 7.0 because the stability of the vanadium dioxide particles in the reaction solution is improved.
  • the compound containing vanadium (V) is not particularly limited as long as it is a compound containing at least pentavalent vanadium (V).
  • vanadium pentoxide V 2 O 5
  • ammonium vanadate NH 4
  • VO 3 vanadium trichloride oxide
  • NaVO 3 sodium metavanadate
  • the reaction liquid according to the present invention may contain a metal compound other than vanadium (V).
  • the metal compound contained other than vanadium (V) is not particularly limited as long as it does not inhibit the effects of the present invention.
  • the metal compound other than vanadium (V) tungsten (W ), Molybdenum (Mo), niobium (Nb), tantalum (Ta), tin (Sn), rhenium (Re), iridium (Ir), osmium (Os), antimony (Sb), ruthenium (Ru), germanium (Ge) ), Chromium (Cr), iron (Fe), gallium (Ga), aluminum (Al), fluorine (F), and phosphorus (P).
  • the metal compound other than vanadium (V) may be a vanadium compound having a valence different from that of vanadium (V), for example, V 2 O 3 (a trivalent vanadium compound).
  • V 2 O 4 tetravalent vanadium compound
  • V 6 O 13 4.3 valent vanadium compound
  • a metal compound other than vanadium (V) can be contained in the reaction solution to change the phase transition temperature exhibiting thermochromic properties, it is also preferable to add it as an additive.
  • the reducing agent used in the present invention may be easily dissolved in water and may function as a reducing agent for compounds containing vanadium (V).
  • a reducing agent for compounds containing vanadium (V) for example, hydrazine (N 2 H 4 ) and hydrazine Hydrazine hydrate (N 2 H 4 .nH 2 O) such as monohydrate and the like can be mentioned.
  • the reducing agent has a thermochromic property (in terms of a molar ratio of 1.0 to 1.4 equivalents with respect to the compound containing vanadium (V)). Vanadium dioxide particles containing VO 2 exhibiting an M phase crystal phase) are preferred because they can be selectively obtained.
  • reaction liquid according to the present invention may be a mixture of substances having oxidizing properties or reducing properties.
  • materials include, for example, hydrogen peroxide (H 2 O 2 ).
  • H 2 O 2 hydrogen peroxide
  • the pH of the reaction solution can be adjusted, or the vanadium compound can be uniformly dissolved.
  • hydrogen peroxide hydrogen peroxide water (concentration 35 mass%, the Wako Pure Chemical Industries make, special grade) can be used suitably, for example.
  • hydrothermal reaction treatment is performed using the prepared reaction solution to form vanadium dioxide particles. That is, in this step, the reaction liquid containing a metal compound other than vanadium (V) is subjected to a hydrothermal reaction.
  • hydrothermal reaction means a chemical reaction that occurs in hot water (subcritical water) whose temperature and pressure are lower than the critical point of water (374 ° C., 22 MPa).
  • a hydrothermal reaction process is implemented in an autoclave apparatus, for example. By the hydrothermal reaction treatment, VO 2 particles containing vanadium dioxide (VO 2 ) are obtained.
  • the conditions of the hydrothermal reaction treatment are appropriately set.
  • the liquid temperature of the hydrothermal reaction treatment is, for example, 250 to 350 ° C. (preferably 270 to 350 ° C., more preferably 300 to 350 ° C.).
  • the hydrothermal reaction is carried out within a liquid temperature range of 250 to 350 ° C., metastable rod-like vanadium dioxide particles that are impurities are less likely to be produced, and the vanadium dioxide particles exhibiting the M phase have a small and uniform particle size. This is preferable.
  • the hydrothermal reaction treatment time is, for example, 1 hour to 7 days, and by increasing the time, the average particle diameter of the obtained VO 2 particles can be controlled, and within 7 days, The possibility of excessive energy consumption can be avoided. More preferably, it is in the range of 12 to 72 hours from the viewpoint of cost.
  • the hydrothermal reaction is preferably performed while stirring, because the particle diameter of the VO 2 particles can be made more uniform.
  • the hydrothermal reaction process may be implemented by a batch type and may be implemented by a continuous type.
  • the reaction solution is oxidized. Specifically, the reaction solution obtained in the particle formation step is cooled to room temperature to oxidize the vanadium dioxide particles.
  • the oxidation method include a method in which the reaction solution is allowed to stand at room temperature, a method in which an oxidizing agent is added, and a method in which oxygen bubbling is performed.
  • the pH at 25 ° C. of the reaction solution after the hydrothermal reaction is preferably in the range of 4.0 to 7.0.
  • the redox potential is preferably in the range of 100 to 500 mV. It is preferable that the pH is within the range because the stability of the vanadium dioxide particles in the reaction solution is improved. Furthermore, it is preferable that the oxidation-reduction potential is within the above range in that the surface oxidation of the particles can be appropriately advanced.
  • the room temperature is, for example, room temperature in the production facility, and specifically, for example, around 25 ° C.
  • oxidant used in the present invention halogen, hypohalous acid, halous acid, perhalogen acid or salts thereof, halogen oxide, peroxide and the like, and known oxidants can be used.
  • the reaction solution containing the VO 2 particles containing the vanadium dioxide (VO 2) having a thermochromic property can be obtained. Thereafter, VO 2 particles according to the present invention are obtained from the reaction solution by filtration, washing, drying and the like.
  • Vanadium dioxide particles (VO 2 particles) VO 2 particles produced by the production method of the VO 2 particles of the present invention contains vanadium dioxide (VO 2), and can provide a vanadium dioxide particles having excellent thermochromic.
  • the average particle diameter of the VO 2 particles is preferably in the range of 5 to 50 nm.
  • the CV value of the particle size distribution of the VO 2 particles is preferably 40 or less.
  • thermochromic properties The thermochromic property of the aqueous dispersion containing vanadium dioxide particles can be measured by using, for example, a spectrophotometer V-670 (manufactured by JASCO Corporation), the light transmittance at a wavelength of 1300 nm that is not affected by the absorption peak of water. It can be measured as a difference.
  • the vanadium dioxide particles produced by the method for producing vanadium dioxide particles according to the present invention are subjected to an oxidation step, so that the ratio of oxygen atoms on the particle surface is increased as compared with conventional vanadium particles exhibiting thermochromic properties. It is thought that there is.
  • the composition of the surface of the vanadium dioxide particles can be measured by a known method, for example, by X-ray photoelectron spectroscopy (XPS: X-ray Photoelectron Spectroscopy).
  • XPS measurement is a technique for irradiating a sample with X-rays and measuring photoelectron energy emitted from the sample. Photoelectrons emitted from deep inside the sample are not scattered because they are not scattered within the sample, and the state near the surface can be evaluated. Therefore, the XPS measurement can detect the surface state within several to several tens of nanometers of the sample. Specifically, the XPS measurement can be performed with an X-ray electron spectrometer (Quantum-2000, manufactured by ULVAC-PHI). The measurement conditions may vary depending on the type of phosphor to be measured, the particle shape, and the like. For example, measurement can be performed under the following measurement conditions.
  • VO 2 particles according to the present invention may contain other compounds or atoms within a range not adversely affecting the effects of the present invention in addition to vanadium dioxide as described above.
  • VO 2 particles VO 2 particles produced by the production method of the present invention are dispersed in water, and vanadium dioxide (VO 2), and a dispersion containing VO 2 particles having a thermochromic Can be provided. If the dispersion containing VO 2 particles produced by the method for producing VO 2 particles of the present invention is applied, an optical film showing excellent thermochromic properties can be provided.
  • distributing should just contain water, and well-known solvents, such as an organic solvent, can be used in the range which does not inhibit the function of vanadium dioxide.
  • the solution stirred for 1 hour after dropping is put into a commercially available autoclave for hydrothermal reaction treatment (manufactured by Sanai Kagaku Co., HU-50) (SUS body is equipped with a 50 ml capacity Teflon (registered trademark) inner cylinder). And hydrothermal reaction at 250 ° C. for 48 hours to obtain a reaction solution. A portion of the reaction solution was immediately diluted 5000 times with pure water to evaluate thermochromic properties.
  • the solution stirred for 1 hour after dropping is put into a commercially available autoclave for hydrothermal reaction treatment (manufactured by Sanai Kagaku Co., HU-50) (SUS body is equipped with a 50 ml capacity Teflon (registered trademark) inner cylinder). And hydrothermal reaction at 250 ° C. for 48 hours to obtain a reaction solution.
  • the reaction solution was transferred to a glass bottle and allowed to stand at 25 ° C. for 72 hours in the atmosphere, and then diluted 5000 times with pure water to evaluate thermochromic properties.
  • the solution stirred for 1 hour after dropping is put into a commercially available autoclave for hydrothermal reaction treatment (manufactured by Sanai Kagaku Co., HU-50) (SUS body is equipped with a 50 ml capacity Teflon (registered trademark) inner cylinder).
  • a hydrothermal reaction was performed at 270 ° C. for 48 hours to obtain a reaction solution.
  • the reaction solution was transferred to a glass bottle and oxygen bubbling was performed at 10 ml / min for 3 hours, and then the thermochromic properties of the reaction solution were evaluated.
  • ⁇ Thermochromic properties (change in light transmittance)>
  • a hydrothermally diluted reaction solution diluted 5000 times with pure water is placed in a commercially available quartz cell with a stopper (two-sided translucent 45 ⁇ 12.5 ⁇ 10 mm), and a spectrophotometer that can be heated (V-manufactured by JASCO Corporation). 670 type, 190-2500 nm) was used, and the measurement temperatures were 20 ° C. and 80 ° C.
  • the temperature dependence of the light transmittance (%; wavelength 1300 nm) of the reaction solution was measured.
  • vanadium dioxide particles exhibiting excellent thermochromic properties can be produced, and these can be suitably used for near infrared light shielding films and the like.

Abstract

The problem of the present invention is to provide a method for producing vanadium dioxide particles that exhibit excellent thermochromicity. A method for producing vanadium dioxide particles containing thermochromic vanadium dioxide wherein the method has a step for forming vanadium dioxide particles by subjecting a reaction solution including a vanadium compound-containing raw material, reducing agent, and water to a hydrothermal reaction and a step for oxidizing the vanadium dioxide particles.

Description

二酸化バナジウム粒子の製造方法Method for producing vanadium dioxide particles
　本発明は、二酸化バナジウム粒子の製造方法に関する。より詳しくは、優れたサーモクロミック性を示す二酸化バナジウム粒子の製造方法に関する。 The present invention relates to a method for producing vanadium dioxide particles. More specifically, the present invention relates to a method for producing vanadium dioxide particles exhibiting excellent thermochromic properties.
　住宅やビル等の建物及び車両などの移動体等では、内部（例えば、室内、車両内）と外部環境との間で大きな熱交換が生じる箇所（例えば、窓ガラス）において、省エネ性と快適性とを両立するために、熱の遮断又は透過を制御可能なサーモクロミック性を有する材料（以下、「サーモクロミック材料」ともいう。）の適用が期待されている。 In buildings such as houses and buildings, and moving bodies such as vehicles, energy saving and comfort are provided in places (for example, window glass) where large heat exchange occurs between the inside (for example, indoors and inside the vehicle) and the external environment. Therefore, application of a material having thermochromic properties (hereinafter, also referred to as “thermochromic material”) capable of controlling the blocking or transmission of heat is expected.
　「サーモクロミック材料」とは、例えば透明状態／反射状態等の光学的な性質が、温度により変化する材料である。具体的には、温度が高い場合は反射状態となり、温度が低い場合は透明状態となる材料である。このようなサーモクロミック材料を、例えば、建物の窓ガラスに適用した場合には、夏には太陽光を反射させて熱を遮断でき、冬には太陽光を透過させて熱を利用できるため、この結果、省エネ性と快適性とを両立できる。 “Thermochromic material” is a material whose optical properties such as transparent state / reflective state change depending on temperature. Specifically, the material is in a reflective state when the temperature is high, and is in a transparent state when the temperature is low. When such a thermochromic material is applied to a window glass of a building, for example, it can reflect sunlight in the summer to block heat, and in winter it can transmit sunlight and use heat, As a result, both energy saving and comfort can be achieved.
　現在、最も着目されているサーモクロミック材料の一つに、二酸化バナジウム（ＶＯ２）を含有する二酸化バナジウム粒子（以下、単に「ＶＯ２粒子」ともいう。）がある。ＶＯ２粒子は、室温付近での相転移の際に、サーモクロミック性（温度により、光学特性が可逆的に変化する性質）を示すことが知られている。したがって、この性質を利用することにより、環境の温度に依存するサーモクロミック性を得ることができる。 At present, one of the thermochromic materials that has received most attention is vanadium dioxide particles containing vanadium dioxide (VO 2 ) (hereinafter also simply referred to as “VO 2 particles”). VO 2 particles are known to exhibit thermochromic properties (property of reversibly changing optical characteristics depending on temperature) during phase transition near room temperature. Therefore, thermochromic properties depending on the temperature of the environment can be obtained by utilizing this property.
　また、酸化バナジウムは、３～５価のバナジウムの酸化物、及び結晶相の多形が複数存在することが知られている。ここで、ＶＯ２の結晶構造には、Ａ相、Ｂ相、Ｃ相及びＲ相（いわゆる「ルチル型の結晶相」）など、いくつかの結晶相の多形が存在する。この中でも、前述のようなサーモクロミック性を示す主な結晶構造はＲ相である。このＲ相は、転移温度以下では、単斜晶系（ｍｏｎｏｃｌｉｎｉｃ）の構造を有するため、Ｍ相とも呼ばれている。
　また、二酸化バナジウム粒子において、実質的に優良なサーモクロミック性を発現させるためには、粒子が凝集していないこと、粒径がナノオーダー（１００ｎｍ以下）であること、粒子が等方的な形状を有していることが望ましい。 In addition, it is known that vanadium oxide has a plurality of polymorphs of oxides and crystal phases of trivalent to pentavalent vanadium. Here, in the crystal structure of VO 2 , there are several polymorphs of crystal phases such as A phase, B phase, C phase and R phase (so-called “rutile crystal phase”). Among these, the main crystal structure exhibiting thermochromic properties as described above is the R phase. Since this R phase has a monoclinic structure below the transition temperature, it is also called an M phase.
In addition, in order to exhibit substantially excellent thermochromic properties in vanadium dioxide particles, the particles are not aggregated, the particle size is nano-order (100 nm or less), and the particles are isotropic. It is desirable to have
　このようなサーモクロミック性を有する部材（フィルムなど）の形成方法として、ＶＯ２粒子又はその分散液を調製し、接着材を介して、サーモクロミック性を発現させたい部材に接着することにより、サーモクロミック性を有する部材を製造することが検討されている（例えば特許文献１及び特許文献２参照。）。 As a method for forming such a thermochromic member (such as a film), a VO 2 particle or a dispersion thereof is prepared and bonded to a member that is desired to exhibit thermochromic properties via an adhesive. It has been studied to manufacture a member having chromic properties (see, for example, Patent Document 1 and Patent Document 2).
　例えば、特許文献１に記載のＶＯ２粒子は、水熱反応で作製されているが、粒子が異方成長してロッド状となっているため、粒子サイズが大きく、良好なサーモクロミック性が得られないという問題がある。
　また、特許文献２では、還元剤にヒドラジンを用い、小粒径化を図っているが、成長過程中に粒子同士が凝集してしまうため、粒径及びサーモクロミック性の制御が困難という問題がある。 For example, the VO 2 particles described in Patent Document 1 are produced by a hydrothermal reaction. However, since the particles grow anisotropically into a rod shape, the particle size is large and good thermochromic properties are obtained. There is a problem that can not be.
In Patent Document 2, hydrazine is used as a reducing agent to reduce the particle size. However, since the particles are aggregated during the growth process, it is difficult to control the particle size and thermochromic property. is there.
特開２０１１－１７８８２５号公報JP 2011-178825 A 米国特許出願公開第２０１３／０３４４３３５号明細書US Patent Application Publication No. 2013/0344435
　本発明は、上記問題・状況に鑑みてなされたものであり、その解決課題は、優れたサーモクロミック性を示す二酸化バナジウム粒子の製造方法を提供することである。 The present invention has been made in view of the above-mentioned problems and situations, and the problem to be solved is to provide a method for producing vanadium dioxide particles exhibiting excellent thermochromic properties.
　本発明者は、上記課題を解決すべく、上記問題の原因等について検討する過程において、水熱反応により二酸化バナジウム粒子を形成し、かつ当該二酸化バナジウム粒子を酸化させることにより、優れたサーモクロミック性を示す二酸化バナジウム粒子を製造することができることを見いだし本発明に至った。
　すなわち、本発明に係る上記課題は、以下の手段により解決される。 In order to solve the above problems, the present inventor formed vanadium dioxide particles by hydrothermal reaction in the process of studying the cause of the above problems, etc., and oxidized the vanadium dioxide particles, thereby providing excellent thermochromic properties. The inventors have found that vanadium dioxide particles exhibiting the following can be produced, and have reached the present invention.
That is, the said subject which concerns on this invention is solved by the following means.
　１．サーモクロミック性を有する二酸化バナジウムを含有する二酸化バナジウム粒子の製造方法であって、
　バナジウム化合物を含有する原料、還元剤及び水を含む反応液を水熱反応させることにより、前記二酸化バナジウム粒子を形成する工程と、
　前記二酸化バナジウム粒子を酸化する工程と、
　を有することを特徴とする二酸化バナジウム粒子の製造方法。 1. A method for producing vanadium dioxide particles containing vanadium dioxide having thermochromic properties,
A step of forming the vanadium dioxide particles by hydrothermal reaction of a reaction solution containing a raw material containing a vanadium compound, a reducing agent and water;
Oxidizing the vanadium dioxide particles;
A method for producing vanadium dioxide particles, comprising:
　２．前記水熱反応後の反応液の２５℃におけるｐＨが、４．０～７．０の範囲内であることを特徴とする第１項に記載の二酸化バナジウム粒子の製造方法。 2. 2. The method for producing vanadium dioxide particles according to item 1, wherein the reaction solution after the hydrothermal reaction has a pH at 25 ° C. in the range of 4.0 to 7.0.
　３．前記水熱反応後の反応液の２５℃における酸化還元電位が、１００～５００ｍＶの範囲内であることを特徴とする第１項又は第２項に記載の二酸化バナジウム粒子の製造方法。 3. 3. The method for producing vanadium dioxide particles according to item 1 or 2, wherein a redox potential at 25 ° C. of the reaction solution after the hydrothermal reaction is in the range of 100 to 500 mV.
　４．前記水熱反応の温度が、２５０～３５０℃の範囲内であることを特徴とする第１項から第３項までのいずれか一項に記載の二酸化バナジウム粒子の製造方法。 4. Item 4. The method for producing vanadium dioxide particles according to any one of Items 1 to 3, wherein a temperature of the hydrothermal reaction is in a range of 250 to 350 ° C.
　５．前記水熱反応の反応時間が、１２～７２時間の範囲内であることを特徴とする第１項から第４項までのいずれか一項に記載の二酸化バナジウム粒子の製造方法。 5. The method for producing vanadium dioxide particles according to any one of items 1 to 4, wherein a reaction time of the hydrothermal reaction is in a range of 12 to 72 hours.
　６．前記二酸化バナジウム粒子が、タングステン（Ｗ）、モリブデン（Ｍｏ）、ニオブ（Ｎｂ）、タンタル（Ｔａ）、スズ（Ｓｎ）、レニウム（Ｒｅ）、イリジウム（Ｉｒ）、オスミウム（Ｏｓ）、アンチモン（Ｓｂ）、ルテニウム（Ｒｕ）、ゲルマニウム（Ｇｅ）、クロム（Ｃｒ）、鉄（Ｆｅ）、ガリウム（Ｇａ）、アルミニウム（Ａｌ）、フッ素（Ｆ）及びリン（Ｐ）からなる群から選ばれた元素を含有することを特徴とする第１項から第５項までのいずれか一項に記載の二酸化バナジウム粒子の製造方法。 6. The vanadium dioxide particles are tungsten (W), molybdenum (Mo), niobium (Nb), tantalum (Ta), tin (Sn), rhenium (Re), iridium (Ir), osmium (Os), antimony (Sb). Contains an element selected from the group consisting of ruthenium (Ru), germanium (Ge), chromium (Cr), iron (Fe), gallium (Ga), aluminum (Al), fluorine (F) and phosphorus (P) The method for producing vanadium dioxide particles according to any one of items 1 to 5, wherein:
　本発明の上記手段により、優れたサーモクロミック性を示す二酸化バナジウム粒子の製造方法を提供することができる。 The above-mentioned means of the present invention can provide a method for producing vanadium dioxide particles exhibiting excellent thermochromic properties.
　本発明の効果の発現機構又は作用機構については、明確にはなっていないが、以下のように推察している。
　二酸化バナジウム粒子を水熱反応で合成すると、一部粒子は還元反応が進みすぎてしまい、粒子表面の酸素原子が電子を残して脱離する酸素欠陥が生じてしまう。このため、低温時でも電子がドープされた状態（金属状態）の二酸化バナジウム粒子を含んでしまい、サーモクロミック性が劣ってしまう。 The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.
When vanadium dioxide particles are synthesized by a hydrothermal reaction, some of the particles undergo a reduction reaction too much, resulting in oxygen defects in which oxygen atoms on the surface of the particles leave and leave electrons. For this reason, it contains vanadium dioxide particles in a state of being doped with electrons (metal state) even at low temperatures, resulting in poor thermochromic properties.
　そこで、サーモクロミック性の悪い、水熱反応後の二酸化バナジウム粒子の粒子表面を、適度に酸化することによって酸素欠陥を減らすことができ、低温時、金属状態であった粒子が非金属状態になることで、サーモクロミック性が向上するものと推察している。 Therefore, oxygen vacancies can be reduced by moderately oxidizing the surface of vanadium dioxide particles that have poor thermochromic properties after hydrothermal reaction, and the particles that are in a metallic state at low temperatures become non-metallic. Therefore, it is presumed that the thermochromic property is improved.
　本発明の二酸化バナジウム粒子の製造方法は、サーモクロミック性を有する二酸化バナジウムを含有する二酸化バナジウム粒子の製造方法であって、バナジウム化合物を含有する原料、還元剤及び水を含む反応液を水熱反応させることにより、前記二酸化バナジウム粒子を形成する工程と、前記二酸化バナジウム粒子を酸化する工程と、を有することを特徴とする。この特徴は、各請求項に係る発明に共通する又は対応する技術的特徴である。 The method for producing vanadium dioxide particles according to the present invention is a method for producing vanadium dioxide particles containing vanadium dioxide having thermochromic properties, and a hydrothermal reaction of a reaction solution containing a raw material containing a vanadium compound, a reducing agent and water. And the step of forming the vanadium dioxide particles and the step of oxidizing the vanadium dioxide particles. This feature is a technical feature common to or corresponding to the claimed invention.
　本発明の実施態様としては、本発明の効果発現の観点から、水熱反応後の反応液の２５℃におけるｐＨが、４．０～７．０の範囲内であることが、反応液中の二酸化バナジウム粒子の安定性が向上するため好ましい。 As an embodiment of the present invention, from the viewpoint of manifestation of the effect of the present invention, the pH at 25 ° C. of the reaction solution after the hydrothermal reaction is within the range of 4.0 to 7.0. This is preferable because the stability of the vanadium dioxide particles is improved.
　本発明においては、水熱反応後の反応液の２５℃における酸化還元電位が、１００～５００ｍＶの範囲内であることが、粒子の表面酸化を適度に進めることができる点で好ましい。 In the present invention, it is preferable that the oxidation-reduction potential at 25 ° C. of the reaction solution after the hydrothermal reaction is in the range of 100 to 500 mV because the surface oxidation of the particles can be appropriately advanced.
　また、本発明においては、水熱反応の温度が、２５０～３５０℃の範囲内であることが、不純物である準安定なロッド状の二酸化バナジウム粒子が生成しにくくなり、Ｍ相を示す二酸化バナジウム粒子が小粒径かつ均一に生成されるため好ましい。 In the present invention, when the temperature of the hydrothermal reaction is in the range of 250 to 350 ° C., metastable rod-like vanadium dioxide particles that are impurities are less likely to be produced, and vanadium dioxide exhibiting an M phase. It is preferable because the particles are small and have a uniform size.
　さらに、本発明においては、本発明の効果発現の観点から、水熱反応の反応時間が、１２～７２時間の範囲内であることが好ましい。 Furthermore, in the present invention, from the viewpoint of manifesting the effects of the present invention, the reaction time of the hydrothermal reaction is preferably within the range of 12 to 72 hours.
　また、本発明においては、二酸化バナジウム粒子が、タングステン（Ｗ）、モリブデン（Ｍｏ）、ニオブ（Ｎｂ）、タンタル（Ｔａ）、スズ（Ｓｎ）、レニウム（Ｒｅ）、イリジウム（Ｉｒ）、オスミウム（Ｏｓ）、アンチモン（Ｓｂ）、ルテニウム（Ｒｕ）、ゲルマニウム（Ｇｅ）、クロム（Ｃｒ）、鉄（Ｆｅ）、ガリウム（Ｇａ）、アルミニウム（Ａｌ）、フッ素（Ｆ）及びリン（Ｐ）からなる群から選ばれた元素を含有することで相転移温度を変化させることができる点で好ましい。 In the present invention, the vanadium dioxide particles are tungsten (W), molybdenum (Mo), niobium (Nb), tantalum (Ta), tin (Sn), rhenium (Re), iridium (Ir), osmium (Os). ), Antimony (Sb), ruthenium (Ru), germanium (Ge), chromium (Cr), iron (Fe), gallium (Ga), aluminum (Al), fluorine (F) and phosphorus (P). It is preferable in that the phase transition temperature can be changed by containing the selected element.
　以下、本発明とその構成要素、及び本発明を実施するための形態・態様について詳細な説明をする。なお、本願において、「～」は、その前後に記載される数値を下限値及び上限値として含む意味で使用する。
　なお、本発明において、２５℃換算でのｐＨとは、測定対象（本発明では、主に反応液）のｐＨを２５℃で測定した場合におけるｐＨの値をいう。 Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In the present application, “˜” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.
In addition, in this invention, pH in 25 degreeC conversion means the value of pH at the time of measuring pH of a measuring object (in this invention, it is a reaction liquid mainly) at 25 degreeC.
　≪二酸化バナジウム粒子の製造方法の概要≫
　本発明の二酸化バナジウム粒子の製造方法は、サーモクロミック性を有する二酸化バナジウムを含有する二酸化バナジウム粒子の製造方法であって、バナジウム化合物を含有する原料、還元剤及び水を含む反応液を水熱反応させることにより、前記二酸化バナジウム粒子を形成する工程と、前記二酸化バナジウム粒子を酸化する工程と、を有することを特徴とする。
　以下に、本発明のサーモクロミック性を有する二酸化バナジウム（ＶＯ２）を含有する二酸化バナジウム粒子（以下、「ＶＯ２粒子」ともいう。）の製造方法について詳細に説明する。 ≪Outline of manufacturing method of vanadium dioxide particles≫
The method for producing vanadium dioxide particles according to the present invention is a method for producing vanadium dioxide particles containing vanadium dioxide having thermochromic properties, and a hydrothermal reaction of a reaction solution containing a raw material containing a vanadium compound, a reducing agent and water. And the step of forming the vanadium dioxide particles and the step of oxidizing the vanadium dioxide particles.
Hereinafter, vanadium dioxide particles containing vanadium dioxide having thermochromic properties of the present invention (VO 2) (hereinafter, also referred to as "VO 2 particles".), The method of production will be explained in detail.
　［１：反応液の調製］
　まず、還元剤、水、バナジウム（Ｖ）を含有する化合物（以下、「バナジウム化合物」ともいう。）を含む溶液を混ぜて反応液を調製する。この反応液は、バナジウム化合物が水中に溶解した水溶液であってもよいし、バナジウム化合物が水中に分散した懸濁液であってもよい。
　なお、反応液の水熱反応後のｐＨ（２５℃換算）は、４．０～７．０の範囲内であることが、反応液中の二酸化バナジウム粒子の安定性が向上するため好ましい。 [1: Preparation of reaction solution]
First, a reaction solution is prepared by mixing a solution containing a reducing agent, water, and a compound containing vanadium (V) (hereinafter also referred to as “vanadium compound”). This reaction solution may be an aqueous solution in which the vanadium compound is dissolved in water, or may be a suspension in which the vanadium compound is dispersed in water.
The pH of the reaction solution after hydrothermal reaction (25 ° C. conversion) is preferably in the range of 4.0 to 7.0 because the stability of the vanadium dioxide particles in the reaction solution is improved.
　＜バナジウム（Ｖ）を含有する化合物＞
　上記バナジウム（Ｖ）を含有する化合物は、少なくとも５価のバナジウム（Ｖ）を含有する化合物であれば、特に限定されず、例えば、五酸化バナジウム（Ｖ２Ｏ５）、バナジン酸アンモニウム（ＮＨ４ＶＯ３）、三塩化酸化バナジウム（ＶＯＣｌ３）、メタバナジン酸ナトリウム（ＮａＶＯ３）が含まれる。 <Compound containing vanadium (V)>
The compound containing vanadium (V) is not particularly limited as long as it is a compound containing at least pentavalent vanadium (V). For example, vanadium pentoxide (V 2 O 5 ), ammonium vanadate (NH 4). VO 3 ), vanadium trichloride oxide (VOCl 3 ), sodium metavanadate (NaVO 3 ).
　＜バナジウム（Ｖ）以外の金属化合物（その他の金属化合物）＞
　本発明に係る反応液は、バナジウム（Ｖ）以外の金属化合物を含有してもよい。バナジウム（Ｖ）以外に含有される金属化合物としては特に限定されず、本発明の効果を阻害しないものであればよいが、具体的には、バナジウム（Ｖ）以外の金属化合物として、タングステン（Ｗ）、モリブデン（Ｍｏ）、ニオブ（Ｎｂ）、タンタル（Ｔａ）、スズ（Ｓｎ）、レニウム（Ｒｅ）、イリジウム（Ｉｒ）、オスミウム（Ｏｓ）、アンチモン（Ｓｂ）、ルテニウム（Ｒｕ）、ゲルマニウム（Ｇｅ）、クロム（Ｃｒ）、鉄（Ｆｅ）、ガリウム（Ｇａ）、アルミニウム（Ａｌ）、フッ素（Ｆ）及びリン（Ｐ）からなる群から選ばれた元素を含有することが好ましい。
　また、バナジウム（Ｖ）以外の金属化合物としては、上記以外にも、バナジウム（Ｖ）とは価数の異なるバナジウムの化合物であってもよく、例えば、Ｖ２Ｏ３（３価のバナジウムの化合物）、Ｖ２Ｏ４（４価のバナジウムの化合物）、Ｖ６Ｏ１３（４．３価のバナジウムの化合物）などが含まれていてもよい。
　バナジウム（Ｖ）以外の金属化合物が、反応液に含有されることで、サーモクロミック性を示す相転移温度を変化させることができるため、添加剤として添加することも好ましい。 <Metal compounds other than vanadium (V) (other metal compounds)>
The reaction liquid according to the present invention may contain a metal compound other than vanadium (V). The metal compound contained other than vanadium (V) is not particularly limited as long as it does not inhibit the effects of the present invention. Specifically, as the metal compound other than vanadium (V), tungsten (W ), Molybdenum (Mo), niobium (Nb), tantalum (Ta), tin (Sn), rhenium (Re), iridium (Ir), osmium (Os), antimony (Sb), ruthenium (Ru), germanium (Ge) ), Chromium (Cr), iron (Fe), gallium (Ga), aluminum (Al), fluorine (F), and phosphorus (P).
In addition to the above, the metal compound other than vanadium (V) may be a vanadium compound having a valence different from that of vanadium (V), for example, V 2 O 3 (a trivalent vanadium compound). ), V 2 O 4 (tetravalent vanadium compound), V 6 O 13 (4.3 valent vanadium compound), and the like may be included.
Since a metal compound other than vanadium (V) can be contained in the reaction solution to change the phase transition temperature exhibiting thermochromic properties, it is also preferable to add it as an additive.
　＜還元剤＞
　本発明で用いられる還元剤は、水に容易に溶解する性質を有し、かつ、バナジウム（Ｖ）を含有する化合物の還元剤として機能すればよく、例えば、ヒドラジン（Ｎ２Ｈ４）及びヒドラジン一水和物などのヒドラジンの水和物（Ｎ２Ｈ４・ｎＨ２Ｏ）などが挙げられる。
　なお、本発明に係る反応液中において、還元剤は、バナジウム（Ｖ）を含有する化合物に対してモル比で、１．０～１．４当量の範囲内であることが、サーモクロミック性（Ｍ相の結晶相）を示すＶＯ２を含有する二酸化バナジウム粒子を選択的に得られるため好ましい。 <Reducing agent>
The reducing agent used in the present invention may be easily dissolved in water and may function as a reducing agent for compounds containing vanadium (V). For example, hydrazine (N 2 H 4 ) and hydrazine Hydrazine hydrate (N 2 H 4 .nH 2 O) such as monohydrate and the like can be mentioned.
In the reaction solution according to the present invention, the reducing agent has a thermochromic property (in terms of a molar ratio of 1.0 to 1.4 equivalents with respect to the compound containing vanadium (V)). Vanadium dioxide particles containing VO 2 exhibiting an M phase crystal phase) are preferred because they can be selectively obtained.
　＜水＞
　本発明に係る水は、特に限定されないが、不純物の少ない高純度のものが好ましく、具体的には、イオン交換水、蒸留水等の精製水を用いることができる。 <Water>
Although the water which concerns on this invention is not specifically limited, The highly purified thing with few impurities is preferable, Specifically, purified water, such as ion-exchange water and distilled water, can be used.
　また、本発明に係る反応液は、酸化性又は還元性を有する物質が更に混ざったものであって良い。このような物質には、例えば、過酸化水素（Ｈ２Ｏ２）が含まれる。酸化性又は還元性を有する物質を添加することにより、反応液のｐＨを調整したり、バナジウム化合物を均一に溶解させたりすることができる。
　なお、過酸化水素としては、例えば、過酸化水素水（濃度３５質量％、和光純薬社製、特級）を好適に用いることができる。 In addition, the reaction liquid according to the present invention may be a mixture of substances having oxidizing properties or reducing properties. Such materials include, for example, hydrogen peroxide (H 2 O 2 ). By adding an oxidizing or reducing substance, the pH of the reaction solution can be adjusted, or the vanadium compound can be uniformly dissolved.
In addition, as hydrogen peroxide, hydrogen peroxide water (concentration 35 mass%, the Wako Pure Chemical Industries make, special grade) can be used suitably, for example.
　［２：粒子形成（水熱反応）工程］
　次に、調製した反応液を用いて、水熱反応処理を行い、二酸化バナジウム粒子を形成する。すなわち、本工程では、バナジウム（Ｖ）以外の金属化合物も含む前記反応液を水熱反応させる。
　ここで、「水熱反応」とは、温度と圧力が、水の臨界点（３７４℃、２２ＭＰａ）よりも低い熱水（亜臨界水）中において生じる化学反応を意味する。水熱反応処理は、例えば、オートクレーブ装置内で実施される。水熱反応処理により、二酸化バナジウム（ＶＯ２）を含有するＶＯ２粒子が得られる。 [2: Particle formation (hydrothermal reaction) step]
Next, hydrothermal reaction treatment is performed using the prepared reaction solution to form vanadium dioxide particles. That is, in this step, the reaction liquid containing a metal compound other than vanadium (V) is subjected to a hydrothermal reaction.
Here, “hydrothermal reaction” means a chemical reaction that occurs in hot water (subcritical water) whose temperature and pressure are lower than the critical point of water (374 ° C., 22 MPa). A hydrothermal reaction process is implemented in an autoclave apparatus, for example. By the hydrothermal reaction treatment, VO 2 particles containing vanadium dioxide (VO 2 ) are obtained.
　水熱反応処理の条件（反応物の量、処理温度、処理圧力、処理時間）は、適宜設定されるが、水熱反応処理の液温は、例えば、２５０～３５０℃（好ましくは、２７０～３５０℃、更に好ましくは、３００～３５０℃）の範囲内である。水熱反応が、液温２５０～３５０℃の範囲内で行われると、不純物である準安定なロッド状の二酸化バナジウム粒子が生成しにくくなり、Ｍ相を示す二酸化バナジウム粒子が小粒径かつ均一に生成されるため好ましい。
　また、水熱反応処理の時間は、例えば１時間～７日であり、時間を長くすることにより、得られるＶＯ２粒子の平均粒径等を制御することができ、７日以内であると、エネルギー消費量が多くなりすぎるおそれを回避できる。より好ましくは、コストの面から１２～７２時間の範囲内である。
　また、水熱反応は、撹拌されながら行われることが、ＶＯ２粒子の粒径をより均一化できるため、好ましい。
　なお、水熱反応処理は、バッチ式で実施してもよく、連続式に実施してもよい。 The conditions of the hydrothermal reaction treatment (reaction amount, treatment temperature, treatment pressure, treatment time) are appropriately set. The liquid temperature of the hydrothermal reaction treatment is, for example, 250 to 350 ° C. (preferably 270 to 350 ° C., more preferably 300 to 350 ° C.). When the hydrothermal reaction is carried out within a liquid temperature range of 250 to 350 ° C., metastable rod-like vanadium dioxide particles that are impurities are less likely to be produced, and the vanadium dioxide particles exhibiting the M phase have a small and uniform particle size. This is preferable.
The hydrothermal reaction treatment time is, for example, 1 hour to 7 days, and by increasing the time, the average particle diameter of the obtained VO 2 particles can be controlled, and within 7 days, The possibility of excessive energy consumption can be avoided. More preferably, it is in the range of 12 to 72 hours from the viewpoint of cost.
In addition, the hydrothermal reaction is preferably performed while stirring, because the particle diameter of the VO 2 particles can be made more uniform.
In addition, the hydrothermal reaction process may be implemented by a batch type and may be implemented by a continuous type.
　［３：酸化工程］
　前記水熱反応後に、反応液を酸化する。
　具体的には、粒子形成工程で得られた反応液を室温まで冷却し、二酸化バナジウム粒子を酸化させる。
　酸化させる方法としては、反応液を室温で静置する方法や、酸化剤を添加する方法、酸素バブリングをする方法等が挙げられる。 [3: Oxidation process]
After the hydrothermal reaction, the reaction solution is oxidized.
Specifically, the reaction solution obtained in the particle formation step is cooled to room temperature to oxidize the vanadium dioxide particles.
Examples of the oxidation method include a method in which the reaction solution is allowed to stand at room temperature, a method in which an oxidizing agent is added, and a method in which oxygen bubbling is performed.
　また、水熱反応をさせた後の反応液の２５℃におけるｐＨは、４．０～７．０の範囲内が好ましい。さらに、酸化還元電位は、１００～５００ｍＶの範囲内であることが好ましい。
　ｐＨが、当該範囲内であることにより、反応液中の二酸化バナジウム粒子の安定性が向上するため好ましい。さらに、酸化還元電位が当該範囲内であることにより、粒子の表面酸化を適度に進めることができる点で好ましい。
　なお、本発明において、室温とは、例えば、製造設備内の室温であり、具体的には、例えば、２５℃前後である。 The pH at 25 ° C. of the reaction solution after the hydrothermal reaction is preferably in the range of 4.0 to 7.0. Furthermore, the redox potential is preferably in the range of 100 to 500 mV.
It is preferable that the pH is within the range because the stability of the vanadium dioxide particles in the reaction solution is improved. Furthermore, it is preferable that the oxidation-reduction potential is within the above range in that the surface oxidation of the particles can be appropriately advanced.
In the present invention, the room temperature is, for example, room temperature in the production facility, and specifically, for example, around 25 ° C.
　＜酸化剤＞
　本発明で用いられる酸化剤としては、ハロゲン、次亜ハロゲン酸、亜ハロゲン酸、過ハロゲン酸又はそれらの塩、ハロゲン酸化物、過酸化物等及び公知の酸化剤が使用できる。 <Oxidizing agent>
As the oxidant used in the present invention, halogen, hypohalous acid, halous acid, perhalogen acid or salts thereof, halogen oxide, peroxide and the like, and known oxidants can be used.
　以上の工程により、サーモクロミック性を有する二酸化バナジウム（ＶＯ２）を含有するＶＯ２粒子を含む反応液が得られる。その後、反応液から、ろ過、洗浄及び乾燥などによって、本発明に係るＶＯ２粒子が得られる。 Through the above process, the reaction solution containing the VO 2 particles containing the vanadium dioxide (VO 2) having a thermochromic property can be obtained. Thereafter, VO 2 particles according to the present invention are obtained from the reaction solution by filtration, washing, drying and the like.
　《二酸化バナジウム粒子（ＶＯ２粒子）》
　本発明のＶＯ２粒子の製造方法によって製造されたＶＯ２粒子は、二酸化バナジウム（ＶＯ２）を含有し、かつ、優れたサーモクロミック性を有する二酸化バナジウム粒子を提供することができる。
　当該ＶＯ２粒子の平均粒径は、５～５０ｎｍの範囲内であることが好ましい。また、ＶＯ２粒子の粒径分布のＣＶ値は、４０以下であることが好ましい。 "Vanadium dioxide particles (VO 2 particles)"
VO 2 particles produced by the production method of the VO 2 particles of the present invention contains vanadium dioxide (VO 2), and can provide a vanadium dioxide particles having excellent thermochromic.
The average particle diameter of the VO 2 particles is preferably in the range of 5 to 50 nm. The CV value of the particle size distribution of the VO 2 particles is preferably 40 or less.
　（サーモクロミック性）
　二酸化バナジウム粒子を含有する水分散液のサーモクロミック性は、例えば、分光光度計Ｖ－６７０（日本分光株式会社製）を用いて、水の吸収ピークによる影響を受けない波長１３００ｎｍにおける光透過率の差として測定することができる。 (Thermochromic properties)
The thermochromic property of the aqueous dispersion containing vanadium dioxide particles can be measured by using, for example, a spectrophotometer V-670 (manufactured by JASCO Corporation), the light transmittance at a wavelength of 1300 nm that is not affected by the absorption peak of water. It can be measured as a difference.
　＜二酸化バナジウム粒子の表面組成＞
　本発明の二酸化バナジウム粒子の製造方法により製造した二酸化バナジウム粒子は、酸化する工程を経ることにより、従来のサーモクロミック性を示すバナジウム粒子と比較して、粒子表面の酸素原子の割合が増加していると考えられる。
　二酸化バナジウム粒子表面の組成は、公知の方法で測定でき、例えば、Ｘ線光電子分光法（ＸＰＳ：Ｘ－ｒａｙ　Ｐｈｏｔｏｅｌｅｃｔｒｏｎ　Ｓｐｅｃｔｒｏｓｃｏｐｙ）により測定できる。 <Surface composition of vanadium dioxide particles>
The vanadium dioxide particles produced by the method for producing vanadium dioxide particles according to the present invention are subjected to an oxidation step, so that the ratio of oxygen atoms on the particle surface is increased as compared with conventional vanadium particles exhibiting thermochromic properties. It is thought that there is.
The composition of the surface of the vanadium dioxide particles can be measured by a known method, for example, by X-ray photoelectron spectroscopy (XPS: X-ray Photoelectron Spectroscopy).
　ＸＰＳ測定は、サンプルにＸ線を照射し、サンプルから放出される光電子エネルギーを測定する手法である。
　サンプルの奥深くから放出された光電子は、サンプル内で散乱されないので検出されず、表面付近の状態を評価することができる。
　そのためＸＰＳ測定は、サンプルの数～数十ｎｍ以内の表面状態を検出することが可能である。
　具体的には、ＸＰＳ測定は、Ｘ線電子分光装置（アルバック・ファイ社製、Ｑｕａｎｔｕｍ－２０００）等によって測定することができる。
　なお、測定条件は、測定対象とする蛍光体の種類や粒子形状などによって変動し得るが、例えば、以下の測定条件で測定することができる。 XPS measurement is a technique for irradiating a sample with X-rays and measuring photoelectron energy emitted from the sample.
Photoelectrons emitted from deep inside the sample are not scattered because they are not scattered within the sample, and the state near the surface can be evaluated.
Therefore, the XPS measurement can detect the surface state within several to several tens of nanometers of the sample.
Specifically, the XPS measurement can be performed with an X-ray electron spectrometer (Quantum-2000, manufactured by ULVAC-PHI).
The measurement conditions may vary depending on the type of phosphor to be measured, the particle shape, and the like. For example, measurement can be performed under the following measurement conditions.
　（表面組成の測定条件）
　Ｘ線源：　ＡｌＫα線、出力：４０Ｗ、測定面積：φ２００μｍ
　パスエネルギー：ワイドスキャン：１８７．８５ｅＶ（１．６０ｅＶ／Ｓｔｅｐ）
　ナロースキャン：５８．７０ｅＶ（０．１２５ｅＶ／Ｓｔｅｐ）
　帯電中和銃：ｅ－
　なお、本発明に係るＶＯ２粒子は、前述のとおり二酸化バナジウム以外にも本発明の効果を阻害しない範囲でその他の化合物や原子を含んでいてもよい。 (Surface composition measurement conditions)
X-ray source: AlKα ray, output: 40 W, measurement area: φ200 μm
Pass energy: Wide scan: 187.85 eV (1.60 eV / Step)
Narrow scan: 58.70 eV (0.125 eV / Step)
Charge neutralizing gun: e −
Incidentally, VO 2 particles according to the present invention may contain other compounds or atoms within a range not adversely affecting the effects of the present invention in addition to vanadium dioxide as described above.
　≪分散液≫
　本発明のＶＯ２粒子の製造方法で製造されたＶＯ２粒子を水に分散させた場合、二酸化バナジウム（ＶＯ２）を含有し、かつ、サーモクロミック性を有するＶＯ２粒子を含有する分散液を提供することができる。本発明のＶＯ２粒子の製造方法で製造された、ＶＯ２粒子を含有する分散液を塗布すれば、優れたサーモクロミック性を示す光学フィルム等を提供することができる。
　また、分散させるための溶媒は、水を含んでいればよく、二酸化バナジウムの機能を阻害しない範囲で有機溶媒等の公知の溶媒を使用することができる。 ≪Dispersion≫
If the VO 2 particles VO 2 particles produced by the production method of the present invention are dispersed in water, and vanadium dioxide (VO 2), and a dispersion containing VO 2 particles having a thermochromic Can be provided. If the dispersion containing VO 2 particles produced by the method for producing VO 2 particles of the present invention is applied, an optical film showing excellent thermochromic properties can be provided.
Moreover, the solvent for disperse | distributing should just contain water, and well-known solvents, such as an organic solvent, can be used in the range which does not inhibit the function of vanadium dioxide.
　なお、本発明を適用可能な実施形態は、上述した実施形態に限定されることなく、本発明の趣旨を逸脱しない範囲で適宜変更可能である。 Note that embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention.
　以下、実施例により本発明を具体的に説明するが、本発明はこれにより限定されるものではない。なお、実施例において「％」の表示を用いるが、特に断りがない限り「質量％」を表す。 Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto. In addition, although the display of "%" is used in an Example, unless otherwise indicated, "mass%" is represented.
　［サンプル１の合成方法］
　過酸化水素水（濃度３５質量％、和光純薬社製、特級）の１０質量％水溶液３０ｍＬに、五酸化バナジウム（Ｖ２Ｏ５、和光純薬社製、特級）０．９ｇを加え、これを４時間撹拌して澄んだ赤茶色のゾルを得た。得られたゾルに、還元剤であるヒドラジン一水和物（Ｎ２Ｈ４・Ｈ２Ｏ、和光純薬社製、特級）の５質量％水溶液２．５ｇをゆっくり滴下した。 [Synthesis Method of Sample 1]
0.9 g of vanadium pentoxide (V 2 O 5 , Wako Pure Chemicals, special grade) is added to 30 mL of a 10% aqueous solution of hydrogen peroxide (concentration 35% by mass, Wako Pure Chemicals, special grade) Was stirred for 4 hours to obtain a clear reddish brown sol. To the obtained sol, 2.5 g of a 5 mass% aqueous solution of hydrazine monohydrate (N 2 H 4 .H 2 O, manufactured by Wako Pure Chemical Industries, Ltd.) as a reducing agent was slowly added dropwise.
　滴下後１時間撹拌した溶液を、市販の水熱反応処理用オートクレーブ（三愛科学社製、ＨＵ－５０型）（ＳＵＳ製本体に５０ｍｌ容積のテフロン（登録商標）製内筒を備える）内に入れ、２５０℃で４８時間、水熱反応させ、反応液を得た。反応液の一部を純水ですぐに５０００倍希釈して、サーモクロミック性を評価した。 The solution stirred for 1 hour after dropping is put into a commercially available autoclave for hydrothermal reaction treatment (manufactured by Sanai Kagaku Co., HU-50) (SUS body is equipped with a 50 ml capacity Teflon (registered trademark) inner cylinder). And hydrothermal reaction at 250 ° C. for 48 hours to obtain a reaction solution. A portion of the reaction solution was immediately diluted 5000 times with pure water to evaluate thermochromic properties.
　［サンプル２の合成方法］
　過酸化水素水（濃度３５質量％、和光純薬社製、特級）の１０質量％水溶液３０ｍｌに、五酸化バナジウム（Ｖ２Ｏ５、和光純薬社製、特級）０．９ｇを加え、これを４時間撹拌して澄んだ赤茶色のゾルを得た。得られたゾルに、還元剤であるヒドラジン一水和物（Ｎ２Ｈ４・Ｈ２Ｏ、和光純薬社製、特級）の５質量％水溶液３．０ｇをゆっくり滴下した。 [Synthesis method of sample 2]
0.9 g of vanadium pentoxide (V 2 O 5 , Wako Pure Chemical Industries, special grade) is added to 30 ml of a 10 mass% aqueous solution of hydrogen peroxide (concentration 35 mass%, manufactured by Wako Pure Chemical Industries, Ltd.) Was stirred for 4 hours to obtain a clear reddish brown sol. To the obtained sol, 3.0 g of a 5 mass% aqueous solution of hydrazine monohydrate (N 2 H 4 .H 2 O, manufactured by Wako Pure Chemical Industries, Ltd.), which is a reducing agent, was slowly added dropwise.
　滴下後１時間撹拌した溶液を、市販の水熱反応処理用オートクレーブ（三愛科学社製、ＨＵ－５０型）（ＳＵＳ製本体に５０ｍｌ容積のテフロン（登録商標）製内筒を備える）内に入れ、２５０℃で４８時間、水熱反応させ、反応液を得た。反応液をガラス瓶に移し、大気下２５℃で７２時間放置してから、純水で５０００倍希釈して、サーモクロミック性を評価した。 The solution stirred for 1 hour after dropping is put into a commercially available autoclave for hydrothermal reaction treatment (manufactured by Sanai Kagaku Co., HU-50) (SUS body is equipped with a 50 ml capacity Teflon (registered trademark) inner cylinder). And hydrothermal reaction at 250 ° C. for 48 hours to obtain a reaction solution. The reaction solution was transferred to a glass bottle and allowed to stand at 25 ° C. for 72 hours in the atmosphere, and then diluted 5000 times with pure water to evaluate thermochromic properties.
　［サンプル３～５の合成方法］
　水熱反応温度を２７０℃に変更した以外はサンプル２と同様の反応液をガラス瓶に移し、２５℃（サンプル３）、５℃（サンプル４）、５０℃（サンプル５）で７２時間放置してから、サーモクロミック性を評価した。 [Synthesis method of samples 3 to 5]
Except for changing the hydrothermal reaction temperature to 270 ° C, the same reaction solution as in sample 2 was transferred to a glass bottle and left at 25 ° C (sample 3), 5 ° C (sample 4), and 50 ° C (sample 5) for 72 hours. From this, thermochromic properties were evaluated.
　［サンプル６及び７の合成方法］
　サンプル３と同様の反応液をガラス瓶に移し、次亜塩素酸ナトリウム溶液（ＮａＣｌＯ、和光純薬社製、化学用、サンプル５）０．５ｇ、又は過マンガン酸カリウム（ＫＭｎＯ４、和光純薬社製、試薬特級、サンプル６）０．５ｇを加え、１時間撹拌してから、サーモクロミック性を評価した。 [Synthesis Method of Samples 6 and 7]
Transfer the same reaction solution as sample 3 to a glass bottle, 0.5 g of sodium hypochlorite solution (NaClO, Wako Pure Chemical Industries, Chemical, sample 5) or potassium permanganate (KMnO 4 , Wako Pure Chemical Industries, Ltd.) Manufactured, reagent special grade, sample 6) 0.5 g was added and stirred for 1 hour, and then the thermochromic properties were evaluated.
　［サンプル８の合成方法］
　過酸化水素水（濃度３５質量％、和光純薬社製、特級）の１０質量％水溶液３０ｍｌに、五酸化バナジウム（Ｖ２Ｏ５、和光純薬社製、特級）０．９ｇとタングステン酸アンモニウムパラ五水和物（（ＮＨ４）１０Ｗ１２Ｏ４１・５Ｈ２Ｏ、和光純薬社製）０．０２９ｇを混合し、これを４時間撹拌して澄んだ赤茶色のゾルを得た。得られたゾルに、還元剤であるヒドラジン一水和物（Ｎ２Ｈ４・Ｈ２Ｏ、和光純薬社製、特級）の５質量％水溶液３．０ｇをゆっくり滴下した。 [Synthesis Method of Sample 8]
To 30 ml of 10% by weight aqueous solution of hydrogen peroxide (concentration 35% by weight, manufactured by Wako Pure Chemical Industries, Ltd.), 0.9 g of vanadium pentoxide (V 2 O 5 , Wako Pure Chemical Industries, special grade) and ammonium tungstate para pentahydrate ((NH 4) 10 W 12 O 41 · 5H 2 O, manufactured by Wako Pure Chemical Industries, Ltd.) and 0.029g were mixed to obtain a sol of clear red-brown and stirred it for 4 hours. To the obtained sol, 3.0 g of a 5 mass% aqueous solution of hydrazine monohydrate (N 2 H 4 .H 2 O, manufactured by Wako Pure Chemical Industries, Ltd.), which is a reducing agent, was slowly added dropwise.
　滴下後１時間撹拌した溶液を、市販の水熱反応処理用オートクレーブ（三愛科学社製、ＨＵ－５０型）（ＳＵＳ製本体に５０ｍｌ容積のテフロン（登録商標）製内筒を備える）内に入れ、２７０℃で４８時間、水熱反応させ、反応液を得た。反応液をガラス瓶に移し、１０ｍｌ／分で３時間酸素バブリングしてから、反応液のサーモクロミック性を評価した。 The solution stirred for 1 hour after dropping is put into a commercially available autoclave for hydrothermal reaction treatment (manufactured by Sanai Kagaku Co., HU-50) (SUS body is equipped with a 50 ml capacity Teflon (registered trademark) inner cylinder). A hydrothermal reaction was performed at 270 ° C. for 48 hours to obtain a reaction solution. The reaction solution was transferred to a glass bottle and oxygen bubbling was performed at 10 ml / min for 3 hours, and then the thermochromic properties of the reaction solution were evaluated.
　［サンプル９の合成方法］
　サンプル８で添加したタングステン酸アンモニウムパラ五水和物をモリブデン酸アンモニウムパラ四水和物０．０９６ｇに変更した以外は同様にして反応液を作製し、反応液のサーモクロミック性を評価した。 [Synthesis Method of Sample 9]
A reaction solution was prepared in the same manner except that the ammonium tungstate parapentahydrate added in Sample 8 was changed to 0.096 g of ammonium molybdate paratetrahydrate, and the thermochromic properties of the reaction solution were evaluated.
　［サンプル１０及び１１の合成方法］
　純水３０ｍｌに、五酸化バナジウム（Ｖ２Ｏ５、和光純薬社製、特級）０．９ｇを加え、ヒドラジン一水和物（Ｎ２Ｈ４・Ｈ２Ｏ、和光純薬社製、特級）の５質量％水溶液３．０ｇを、をゆっくり滴下した溶液を市販の水熱反応処理用オートクレーブで水熱反応させ（サンプル１０：２８５℃で７２時間、サンプル１１：３４０℃で１２時間）、反応液を得た。反応液をガラス瓶に移し、１０ｍｌ／分で３時間酸素バブリングしてから、純水で５０００倍希釈して、サーモクロミック性を評価した。 [Synthesis Method of Samples 10 and 11]
To 30 ml of pure water, 0.9 g of vanadium pentoxide (V 2 O 5 , Wako Pure Chemical Industries, special grade) is added, and hydrazine monohydrate (N 2 H 4 · H 2 O, Wako Pure Chemical Industries, special grade) is added. ) Was slowly dropped in a commercially available autoclave for hydrothermal reaction treatment (sample 10: 285 ° C. for 72 hours, sample 11: 340 ° C. for 12 hours), A reaction solution was obtained. The reaction solution was transferred to a glass bottle and subjected to oxygen bubbling at 10 ml / min for 3 hours, and then diluted 5000 times with pure water to evaluate thermochromic properties.
　［サンプル１２の合成方法］
　サンプル１１に添加剤として三酸化アンチモン０．０２３ｇを添加した以外は同様にして反応液を作製し、反応液のサーモクロミック性を評価した。 [Synthesis Method of Sample 12]
A reaction solution was prepared in the same manner except that 0.023 g of antimony trioxide was added as an additive to Sample 11, and the thermochromic properties of the reaction solution were evaluated.
　《二酸化バナジウム含有反応液の評価》
　＜ｐＨ及び標準酸化還元電位（ＯＲＰ）測定＞
　ｐＨ／ＯＲＰメータ　ＴＰＸ－９９９ｉ（東興化学社製）を用い、２５℃にてｐＨ及びＯＲＰの測定を行った。 << Evaluation of reaction liquid containing vanadium dioxide >>
<Measurement of pH and standard redox potential (ORP)>
The pH and ORP were measured at 25 ° C. using a pH / ORP meter TPX-999i (manufactured by Toko Chemical Co., Ltd.).
　＜サーモクロミック性（光透過率変化）＞
　純水で５０００倍希釈した水熱後反応液を市販の栓付石英セル（２面透光型４５×１２．５×１０ｍｍ）内に入れ、加熱可能な分光光度計（日本分光社製Ｖ－６７０型、１９０－２５００ｎｍ）を使用し、測定温度は、２０℃及び８０℃とした。また、反応液の光透過率（％；波長１３００ｎｍ）の温度依存性を測定した。 <Thermochromic properties (change in light transmittance)>
A hydrothermally diluted reaction solution diluted 5000 times with pure water is placed in a commercially available quartz cell with a stopper (two-sided translucent 45 × 12.5 × 10 mm), and a spectrophotometer that can be heated (V-manufactured by JASCO Corporation). 670 type, 190-2500 nm) was used, and the measurement temperatures were 20 ° C. and 80 ° C. Moreover, the temperature dependence of the light transmittance (%; wavelength 1300 nm) of the reaction solution was measured.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　（まとめ）
　表１に示されるように、本発明のＶＯ２粒子の製造方法によって製造されたＶＯ２粒子は、優れたサーモクロミック性を示すことがわかった。 (Summary)
As shown in Table 1, it was found that the VO 2 particles produced by the method for producing VO 2 particles of the present invention showed excellent thermochromic properties.
　本発明により、優れたサーモクロミック性を示す二酸化バナジウム粒子を製造することができ、これらは近赤外光遮蔽フィルム等に好適に利用できる。 According to the present invention, vanadium dioxide particles exhibiting excellent thermochromic properties can be produced, and these can be suitably used for near infrared light shielding films and the like.

Claims (6)

  1. 　サーモクロミック性を有する二酸化バナジウムを含有する二酸化バナジウム粒子の製造方法であって、
    　バナジウム化合物を含有する原料、還元剤及び水を含む反応液を水熱反応させることにより、前記二酸化バナジウム粒子を形成する工程と、
    　前記二酸化バナジウム粒子を酸化する工程と、
    　を有することを特徴とする二酸化バナジウム粒子の製造方法。     A method for producing vanadium dioxide particles containing vanadium dioxide having thermochromic properties,
    A step of forming the vanadium dioxide particles by hydrothermal reaction of a reaction solution containing a raw material containing a vanadium compound, a reducing agent and water;
    Oxidizing the vanadium dioxide particles;
    A method for producing vanadium dioxide particles, comprising:
  2. 　前記水熱反応後の反応液の２５℃におけるｐＨが、４．０～７．０の範囲内であることを特徴とする請求項１に記載の二酸化バナジウム粒子の製造方法。 The method for producing vanadium dioxide particles according to claim 1, wherein the pH of the reaction solution after the hydrothermal reaction at 25 ° C is within a range of 4.0 to 7.0.
  3. 　前記水熱反応後の反応液の２５℃における酸化還元電位が、１００～５００ｍＶの範囲内であることを特徴とする請求項１又は請求項２に記載の二酸化バナジウム粒子の製造方法。 The method for producing vanadium dioxide particles according to claim 1 or 2, wherein an oxidation-reduction potential at 25 ° C of the reaction solution after the hydrothermal reaction is in a range of 100 to 500 mV.
  4. 　前記水熱反応の温度が、２５０～３５０℃の範囲内であることを特徴とする請求項１から請求項３までのいずれか一項に記載の二酸化バナジウム粒子の製造方法。 The method for producing vanadium dioxide particles according to any one of claims 1 to 3, wherein a temperature of the hydrothermal reaction is in a range of 250 to 350 ° C.
  5. 　前記水熱反応の反応時間が、１２～７２時間の範囲内であることを特徴とする請求項１から請求項４までのいずれか一項に記載の二酸化バナジウム粒子の製造方法。 The method for producing vanadium dioxide particles according to any one of claims 1 to 4, wherein a reaction time of the hydrothermal reaction is within a range of 12 to 72 hours.
  6. 　前記二酸化バナジウム粒子が、タングステン（Ｗ）、モリブデン（Ｍｏ）、ニオブ（Ｎｂ）、タンタル（Ｔａ）、スズ（Ｓｎ）、レニウム（Ｒｅ）、イリジウム（Ｉｒ）、オスミウム（Ｏｓ）、アンチモン（Ｓｂ）、ルテニウム（Ｒｕ）、ゲルマニウム（Ｇｅ）、クロム（Ｃｒ）、鉄（Ｆｅ）、ガリウム（Ｇａ）、アルミニウム（Ａｌ）、フッ素（Ｆ）及びリン（Ｐ）からなる群から選ばれた元素を含有することを特徴とする請求項１から請求項５までのいずれか一項に記載の二酸化バナジウム粒子の製造方法。 The vanadium dioxide particles are tungsten (W), molybdenum (Mo), niobium (Nb), tantalum (Ta), tin (Sn), rhenium (Re), iridium (Ir), osmium (Os), antimony (Sb). Contains an element selected from the group consisting of ruthenium (Ru), germanium (Ge), chromium (Cr), iron (Fe), gallium (Ga), aluminum (Al), fluorine (F) and phosphorus (P) The method for producing vanadium dioxide particles according to any one of claims 1 to 5, wherein:
PCT/JP2016/069700 2015-09-30 2016-07-01 Method for producing vanadium dioxide particles WO2017056613A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011178825A (en) * 2010-02-26 2011-09-15 National Institute Of Advanced Industrial Science & Technology Single crystal fine particle, method for producing the same, and application thereof
JP2014505651A (en) * 2011-01-21 2014-03-06 中国科学院上海硅酸塩研究所 Doped vanadium dioxide powder, dispersions and their production and application
WO2016052740A1 (en) * 2014-10-03 2016-04-07 コニカミノルタ株式会社 Optical film and process for producing optical film

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011178825A (en) * 2010-02-26 2011-09-15 National Institute Of Advanced Industrial Science & Technology Single crystal fine particle, method for producing the same, and application thereof
JP2014505651A (en) * 2011-01-21 2014-03-06 中国科学院上海硅酸塩研究所 Doped vanadium dioxide powder, dispersions and their production and application
WO2016052740A1 (en) * 2014-10-03 2016-04-07 コニカミノルタ株式会社 Optical film and process for producing optical film

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