JP2018154517A - Method for producing vanadium dioxide-containing particle and vanadium dioxide-containing particle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing vanadium dioxide-containing particles which upon blending with resin is capable of giving a molded article having improved heat storage properties.SOLUTION: A method for producing vanadium dioxide-containing particles is provided which comprises a hydrothermal reaction step of causing a reaction liquid containing a vanadium-containing compound and water to undergo a hydrothermal reaction to give a vanadium dioxide-containing particle precursor; and a calcination step of calcining the vanadium dioxide-containing particle precursor under an inert gas atmosphere. In the calcination step, the calcination temperature is 300 to 600°C, and the calcination time is 1 to 20 hours.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing vanadium dioxide-containing particles and vanadium dioxide-containing particles.

  The heat storage material has a temperature adjustment function of maintaining a constant temperature with respect to a change in the outside air temperature, and is generally known as a cold insulation agent or a heat insulation agent that is not a heat insulating material. The heat storage material is also used for waste heat use in factories and automobiles.

  Heat storage materials that use a large specific heat of the substance (sensible heat storage material), those that use the phase change heat of the substance (for example, phase change of melting-solidification) (latent heat storage material), heat generated by chemical reaction There are things to use. Above all, the latent heat storage material can be used repeatedly, and has a merit that the heat storage capacity is larger than other heat storage materials, and various developments have been made. A typical example of a latent heat storage material is vanadium dioxide. It is known that vanadium dioxide undergoes a phase transition in a temperature range of around 65 ° C. and exhibits characteristics as a heat storage material.

  As a method for obtaining such vanadium dioxide, for example, in Patent Document 1, a solid containing vanadium oxide is used as a raw material, and the solid containing vanadium dioxide is made into a particle size of 1 to 100 nm by wet grinding, A step B of adjusting the particle size of the vanadium dioxide fine particles to 10 to 150 nm by firing the fine particles obtained in the step A in a temperature range of 350 to 550 ° C. in an inert gas atmosphere. A method for producing vanadium dioxide fine particles in which the proportion of particles having a diameter of 10 to 150 nm is 90% or more is disclosed.

  Further, Patent Document 2 discloses a first step of preparing a slurry containing a precipitate deposited by adding an alkali to a solution containing a vanadium source, and then subjecting the slurry to a hydrothermal reaction to produce a reaction precursor. A second step for obtaining a fired product by firing the reaction precursor in an inert gas atmosphere, and then a fourth step for annealing the fired product. A method for producing vanadium dioxide, comprising adding a compound containing a metal element to a solution containing a source and / or a slurry containing the precipitate, is disclosed.

JP 2017-1929 A Japanese Patent Laid-Open No. 2006-160148

  However, when the vanadium dioxide particles produced using the techniques described in Patent Documents 1 and 2 are blended with a resin, there is a problem that the heat storage property of the obtained molded article is lowered.

  Then, an object of this invention is to provide the manufacturing method of vanadium dioxide containing particle | grains which can improve the thermal storage property of the molded object obtained by blending with resin.

  The present inventors have conducted intensive research to solve the above problems. As a result, the reaction solution containing the vanadium-containing compound and water is hydrothermally reacted to obtain a vanadium dioxide-containing particle precursor, and the obtained vanadium dioxide-containing particle precursor is obtained at a specific range of firing temperature and firing time. It has been found that the above problems can be solved by a method for producing vanadium dioxide-containing particles having a firing step, and the present invention has been completed.

  That is, the present invention includes a hydrothermal reaction step in which a reaction solution containing a vanadium-containing compound and water is subjected to hydrothermal reaction to obtain a vanadium dioxide-containing particle precursor, and the vanadium dioxide-containing particle precursor is calcined in an inert gas atmosphere. A method for producing vanadium dioxide-containing particles having a firing temperature in the firing step of 300 to 600 ° C. and a firing time of 1 to 20 hours. .

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the vanadium dioxide containing particle | grains which can improve the thermal storage property of the molded object obtained by blending with resin is provided.

It is the schematic which shows an example of the flow-type reaction apparatus which has a hydrothermal reaction part used for the hydrothermal reaction process which concerns on this invention.

  The present invention includes a hydrothermal reaction step in which a reaction solution containing a vanadium-containing compound and water is subjected to a hydrothermal reaction to obtain a vanadium dioxide-containing particle precursor, and a firing step in which the vanadium dioxide-containing particle precursor is fired in an inert gas atmosphere. And a method for producing vanadium dioxide-containing particles, wherein the firing temperature in the firing step is 300 to 600 ° C. and the firing time is 1 to 20 hours. The vanadium dioxide-containing particles of the present invention obtained by the production method having the steps described above can improve the dispersibility in the resin and improve the heat storage property of the molded product obtained by blending with the resin.

  Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments.

[Method for producing vanadium dioxide-containing particles]
The method for producing vanadium dioxide-containing particles of the present invention comprises a hydrothermal reaction step of hydrothermally reacting a reaction solution containing a vanadium-containing compound and water to obtain a vanadium dioxide-containing particle precursor, and the vanadium dioxide-containing particle precursor is inert. Firing in a gas atmosphere at a firing temperature of 300 to 600 ° C. for a firing time of 1 to 20 hours to obtain vanadium dioxide-containing particles.

(Hydrothermal reaction process)
In this step, the reaction solution containing the vanadium-containing compound and water is subjected to a hydrothermal reaction. By this step, a vanadium dioxide-containing particle precursor is obtained.

The vanadium-containing compound is not particularly limited, vanadium pentoxide _{(V) (V 2 O 5} ), ammonium vanadate _{(V) (NH 4 VO 3} ), trichloride oxide, vanadium (V) (VOCl _3), Sodium vanadate (V) (NaVO ₃ ), vanadyl oxalate (IV) (VOC ₂ O ₄ ), vanadium oxide sulfate (IV) (VOSO ₄ ), divanadium tetroxide (IV) (V ₂ O ₄ ), etc. Can be mentioned. These vanadium-containing compounds may be hydrated (hydrates).

  The vanadium-containing compounds may be used alone or in combination of two or more. Furthermore, as the vanadium-containing compound, a commercially available product may be used, or a synthetic product may be used.

Here, the hydrothermal reaction is
(A-1) The vanadium-containing compound is a vanadium (IV) -containing compound, and the reaction is performed in a reaction solution containing an alkali as a compound that reacts with the vanadium-containing compound.
Or (a-2) the vanadium-containing compound is a vanadium (V) -containing compound, and the reaction is performed in a reaction solution containing a reducing agent as a compound that reacts with the vanadium-containing compound,
Is preferred. Hereinafter, the method (a-1) and the method (a-2) will be described.

<Method (a-1)>
In the above (a-1), the vanadium (IV) -containing compound (raw material of vanadium dioxide-containing particles) is not particularly limited, and vanadyl oxalate (IV) (VOC ₂ O ₄ ), vanadium oxide sulfate (IV) (VOSO) ₄ ), divanadium tetroxide (IV) (V ₂ O ₄ ), or a hydrate thereof, and the like. From the viewpoint of generating as little by-product as possible after the hydrothermal reaction, vanadium oxide (IV) sulfate (VOSO ₄ ) is preferable. In addition, you may use a vanadium (IV) containing compound individually or in mixture of 2 or more types. In addition, said vanadium (IV) containing compound may be melt | dissolved in the reaction liquid, and may be disperse | distributed.

  The initial concentration of the vanadium (IV) -containing compound contained in the reaction solution obtained by mixing each raw material solution is not particularly limited as long as the object effect of the present invention is obtained, but preferably 0.1 to 1000 mmol / L. It is. If it is such a density | concentration, a vanadium (IV) containing compound can fully melt | dissolve or disperse | distribute, the average secondary particle diameter of the vanadium dioxide containing particle | grains obtained can be made into a desired range, and vanadium dioxide containing particle | grains are included. The heat storage property of a molded object can be improved more. In addition, said "initial concentration" is the amount of vanadium (IV) -containing compounds in 1 L of the reaction solution before hydrothermal reaction (the total amount when two or more vanadium (IV) -containing compounds are included). is there.

As described in (a-1) above, the compound that reacts with the vanadium-containing compound that can be used with the vanadium (IV) -containing compound is preferably an alkali. That is, according to one embodiment, the hydrothermal reaction step is performed in a reaction solution in which the vanadium-containing compound is a vanadium (IV) -containing compound and the compound that reacts with the vanadium-containing compound includes at least one alkali. preferable. Furthermore, it is more preferable that the compound that reacts with the vanadium-containing compound consists only of alkali. In the present specification, alkali means a substance that generates hydroxide ions (OH ⁻ ) in an aqueous solution, and includes not only hydroxides but also substances that eventually generate hydroxide ions. Shall be.

  Although it does not restrict | limit especially as an alkali, Ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogencarbonate, potassium carbonate, potassium hydrogencarbonate, etc. are mentioned. The said alkali can be used individually by 1 type or in combination of 2 or more types.

  Among these, ammonia, sodium hydroxide, or potassium hydroxide is preferable, ammonia or sodium hydroxide is more preferable, and ammonia is more preferable.

  Here, the amount of alkali in the reaction liquid obtained by mixing each raw material liquid is not particularly limited, but includes, for example, a raw material liquid containing a vanadium-containing compound and water, a compound that reacts with the vanadium-containing compound, and water. It is preferable to add such an amount that the pH of the reaction liquid obtained by mixing the raw material liquid becomes 7.5 to 10.

<Method (a-2)>
In the above (a-2), the vanadium (V) -containing compound (raw material of vanadium dioxide-containing particles) is not particularly limited, and divanadium pentoxide (V) (V ₂ O ₅ ), ammonium vanadate (V) ( NH ₄ VO ₃ ), vanadium trichloride (V) (VOCl ₃ ), sodium vanadate (V) (NaVO ₃ ), or a hydrate thereof can be appropriately selected. From the viewpoint of generating as little by-products as possible after the hydrothermal reaction, divanadium pentoxide (V) (V ₂ O ₅ ), ammonium vanadate (V) (NH ₄ VO ₃ ), and vanadium trichloride (V) ( VOCl ₃ ) is preferred. More preferred are divanadium pentoxide and ammonium vanadate, and particularly preferred is ammonium vanadate. In addition, said vanadium (V) containing compound may be melt | dissolved in the reaction liquid, and may be disperse | distributed. Moreover, the said vanadium (V) containing compound may be used individually or in mixture of 2 or more types.

  The initial concentration of the vanadium (V) -containing compound contained in the reaction solution is not particularly limited as long as the objective effect of the present invention can be obtained, but is preferably 0.1 to 1000 mmol / L. With such a concentration, the reducing agent acts efficiently, the average secondary particle diameter of the obtained vanadium dioxide-containing particles can be within a desired range, and the heat storage property of the molded body containing the vanadium dioxide-containing particles can be increased. Can be increased. In addition, said "initial concentration" is the amount of vanadium (V) containing compounds in 1 L of reaction liquid before the hydrothermal reaction (the total amount when two or more vanadium (V) containing compounds are included). is there.

As described in (a-2) above, the compound that reacts with the vanadium-containing compound that can be used together with the vanadium (V) -containing compound is preferably a reducing agent. Examples of the reducing agent include oxalic acid and its hydrate, hydrazine (N ₂ H ₄ ) and its hydrate (N ₂ H ₄ .H ₂ O), water-soluble vitamins such as ascorbic acid, and derivatives thereof, Examples include sodium erythorbate, BHT (dibutylhydroxytoluene), BHA (butylhydroxyanisole), antioxidants such as propyl gallate and sodium sulfite, and reducing sugars such as glucose, fructose, glyceraldehyde, lactose and maltose. The said reducing agent can be used individually by 1 type or in combination of 2 or more types.

  The reducing agent is more preferably hydrazine or a hydrate thereof. That is, according to one embodiment, in the hydrothermal reaction step, the vanadium-containing compound is a vanadium (V) -containing compound, and the compound that reacts with the vanadium-containing compound includes at least one of hydrazine and a hydrate thereof. More preferably, Furthermore, it is more preferable that the compound that reacts with the vanadium-containing compound is only one of hydrazine and its hydrate.

  Here, the amount of the reducing agent in the reaction solution obtained by mixing each raw material solution is added in an equimolar amount or more with respect to the vanadium (V) -containing compound in consideration of the pH during the reaction and the amount decomposed during the reaction. It is preferable to do. For example, it is more preferable that it is about 1.01-1.50 mol with respect to 1 mol of vanadium (V) containing compounds, and it is still more preferable that it is 1.05-1.30 mol.

  Further, when divanadium pentoxide is used as the vanadium (V) -containing compound, it is preferable to perform a pretreatment in the presence of hydrogen peroxide before the hydrothermal reaction. By adding hydrogen peroxide, the vanadium-containing compound can be uniformly dissolved. Alternatively, the vanadium-containing compound may be pretreated in the presence of hydrogen peroxide and a reducing agent before the hydrothermal reaction. When a reduction reaction with a reducing agent is employed after a pretreatment with hydrogen peroxide, hydrogen peroxide and a reducing agent are sequentially added, for example, at 20 to 40 ° C., with stirring as necessary, 0.5 to 10 The reaction can be performed for about an hour.

  The pH of the reaction solution obtained by mixing the raw material solutions differs depending on the vanadium (V) -containing compound used, and is preferably adjusted by the amount of reducing agent added. For example, in the case of ammonium vanadate, it is preferable to add an amount such that the pH is 8.0 to 11.0, and it is more preferable to add an amount that is 9.0 to 10.0. In the case of vanadium pentoxide or vanadium trichloride oxide, it is preferable to add an amount such that the pH is 3.5 to 5.5, and it is more preferable to add an amount such that 4.0 to 5.0. .

<Water>
The raw material liquid containing the vanadium-containing compound and water, and the water in the raw material liquid containing the compound that reacts with the vanadium-containing compound and the water function as a dispersion medium or a solvent for the vanadium-containing compound and the compound that reacts with the vanadium-containing compound, respectively. Have. The reaction liquid obtained by mixing each raw material liquid also contains water as a dispersion medium or a solvent.

  The water contained in these raw material liquids is preferably one with few impurities, and is not particularly limited, but for example, distilled water, ion exchange water, pure water, ultrapure water, deaerated water, etc. are preferably used. . The deaerated water here is water having an amount of dissolved oxygen at 25 ° C. of 4.0 mg / L or less, preferably 2.0 mg / L or less, more preferably 1.0 mg / L or less, Especially preferably, it is 0.4 mg / L or less. If the amount of dissolved oxygen is in the above range, oxidation in the reaction system, suppression of decomposition due to oxidation, and prevention of foaming can be achieved.

<Phase transition regulator>
The reaction solution may further include a substance containing an element for adjusting the phase transition temperature of the vanadium dioxide-containing particles (also referred to as “phase transition modifier” in this specification). That is, the manufacturing method according to an aspect of the present invention is a manufacturing method in which the reaction solution further includes a substance containing an element for adjusting the phase transition temperature of the vanadium dioxide-containing particles.

Phase transition modifiers are not particularly limited, but elements other than vanadium such as tungsten, titanium, molybdenum, niobium, tantalum, tin, rhenium, iridium, osmium, ruthenium, germanium, chromium, iron, gallium, aluminum, fluorine, phosphorus, etc. Substances containing can be used. When the reaction liquid contains the phase change regulator, the phase transition temperature of the obtained vanadium dioxide-containing particles can be lowered. Here, the amount of addition of the phase transition modifier is not particularly limited, but the element ratio (atomic ratio) between vanadium contained in the vanadium-containing compound and other elements contained in the phase transition modifier is 50.0: 50. The amount is preferably 0.0 to 99.9: 0.1, and more preferably 70.0: 30.0 to 99.5: 0.5. The form of the phase transition regulator is not particularly limited, and examples thereof include oxides and ammonium salts of the other elements. Specific examples of the phase transition modulators, for example, ammonium tungstate para pentahydrate _{((NH 4) 10 W 12} O 41 · 5H 2 O), hexaammonium heptamolybdate tetrahydrate _((NH 4) _{6 Mo 7 O 24 · 4H 2} O), tantalum chloride (TaCl _5), mention may be made of niobium chloride (NbCl ₅₎ or the like.

  The method for adding the phase transition regulator to the reaction solution is not particularly limited, and a known method can be used. For example, the method of adding to the raw material liquid containing a vanadium containing compound and water, and the method of adding directly to the reaction liquid before a hydrothermal reaction are mentioned.

<Hydrothermal reaction conditions>
In this step, the reaction solution is hydrothermally reacted to form a vanadium dioxide-containing particle precursor. The “hydrothermal reaction” means a mineral synthesis or alteration reaction, that is, a chemical reaction performed in the presence of high-temperature water, particularly high-temperature and high-pressure water.

  The hydrothermal reaction is characterized in that it is carried out in a state where the temperature is 150 ° C. or higher and the pressure is higher than the saturated vapor pressure, that is, water is present in a subcritical or supercritical state. It is known that by carrying out the reaction under such conditions, a peculiar reaction can occur, unlike the case of normal pressure and high temperature where water can hardly exist. It is also known that the solubility of oxides such as silica and alumina is improved and the reaction rate is improved.

  Hydrothermal reaction conditions are not particularly limited as long as the temperature under which water is present in a subcritical or supercritical state is 150 ° C. or higher and the pressure is equal to or higher than the saturated vapor pressure, and other conditions ( For example, it can be appropriately set according to the amount of reaction product, reaction time, and the like.

  The temperature and pressure during the hydrothermal reaction are not particularly limited as long as it is 150 ° C. or higher and the pressure is equal to or higher than the saturated vapor pressure, as described above, but the temperature is 230 ° C. to 450 ° C., Is more preferably 3 to 40 MPa, and more preferably a pressure equal to or higher than the saturated vapor pressure at the set temperature.

  The hydrothermal reaction time is not particularly limited, but is preferably 0.1 second to 48 hours. If it is reaction time as above-mentioned, the vanadium dioxide containing particle | grains which have a desired average secondary particle diameter can be manufactured efficiently. Moreover, the possibility that the crystallinity of the vanadium dioxide-containing particles is lowered can be avoided. The hydrothermal reaction may be performed in one stage using the same conditions, or may be performed in multiple stages by changing the conditions.

  The hydrothermal reaction step can be carried out using a flow reactor having a hydrothermal reactor or a batch reactor such as an autoclave. Especially, it is preferable to carry out using the flow-type reaction apparatus which has a hydrothermal reaction part.

  When a flow reactor having a hydrothermal reaction section is used, a reaction at a higher temperature and a higher pressure is possible as compared with the case of using a batch reactor, so that the reaction time can be further shortened. Thereby, secondary aggregation of the vanadium dioxide-containing particle precursor is less likely to occur, and the average secondary particle diameter of the obtained vanadium dioxide-containing particles can be further reduced. Furthermore, the average primary particle diameter of the obtained vanadium dioxide-containing particles can be further reduced and the particle size distribution can be narrowed by directly mixing water in a subcritical or supercritical state with the reaction liquid. Since vanadium dioxide-containing particles having a small average primary particle size or average secondary particle size can be more uniformly dispersed in the resin, the heat storage property of the molded product obtained by blending with the resin is further improved.

  Hereinafter, an embodiment using ion-exchanged water will be described as an embodiment in which a hydrothermal reaction is performed using a flow reactor having a hydrothermal reaction section. In addition, this invention is not limited to the following embodiment.

<Flow-type reactor>
When hydrothermal reaction is carried out using a flow reactor having a hydrothermal reaction section, in the hydrothermal reaction section, a raw material solution containing a vanadium-containing compound and ion-exchanged water, and a compound that reacts with the vanadium-containing compound The passage time of the reaction liquid mixed with supercritical or subcritical ion exchange water is preferably in the range of 0.1 to 700 seconds, and more preferably in the range of 1 to 600 seconds.

  In this step, the reaction solution is basically 1) a raw material solution containing a vanadium-containing compound and ion-exchanged water, 2) a compound that reacts with the vanadium-containing compound, and 3) ion exchange in a supercritical or subcritical state. Although composed of water, at least 1) a raw material liquid containing a vanadium-containing compound and ion-exchanged water, and 3) supercritical or subcritical ion-exchanged water are divided into 1) or 3), 2 ) A form in which a compound that reacts with a vanadium-containing compound coexists is preferable.

  Specifically, according to one embodiment, in the raw material liquid container, 1) a raw material liquid containing a vanadium-containing compound and ion-exchanged water, and 2) a compound that reacts with the vanadium-containing compound, for example, ion-exchanged water at a predetermined concentration. Dissolved alkali or reducing agent is added, ion-exchanged water is added as water to the other raw material liquid container, and this ion-exchanged water is ionized in a supercritical or subcritical state with a heating medium at a predetermined temperature and pressure. After making the exchange water, the two are assembled at the confluence to make a reaction solution, and then hydrothermal treatment is performed in the heating part piping in the hydrothermal reaction part constituting the hydrothermal reaction part to prepare a vanadium dioxide-containing particle precursor (This method is also referred to as Embodiment 1).

  On the other hand, according to another embodiment, 1) a raw material liquid containing a vanadium-containing compound and ion-exchanged water is added to the raw material liquid container, and 2) a compound that reacts with the vanadium-containing compound is contained in the other raw material liquid container. The ion-exchanged water containing the compound that reacts with the vanadium-containing compound is made into a supercritical or subcritical ion-exchanged water under a predetermined temperature and pressure with a heating medium, This is a method for preparing a vanadium dioxide-containing particle precursor by making a reaction liquid by associating at a confluence, and then subjecting it to a hydrothermal treatment in a heating part pipe in the hydrothermal reaction part constituting the hydrothermal reaction part (this method Also referred to as Embodiment 2.)

  Next, in the present invention, the overall configuration of a flow reactor having a hydrothermal reaction section, which can be preferably used as an example of a flow reactor applied in the method for producing vanadium dioxide-containing particles, will be described with reference to the drawings. To do.

  FIG. 1 is a schematic view showing an example of a flow reaction apparatus having a hydrothermal reaction section that can be applied to the hydrothermal reaction process according to the present invention.

  In FIG. 1, a flow reactor (101) having a hydrothermal reaction section includes a raw material solution containing one component liquid, a vanadium-containing compound, a compound that reacts with a vanadium-containing compound, and ion-exchanged water (Embodiment 1). Or a raw material liquid container 1 (105) for containing a raw material liquid (embodiment 2) containing a vanadium-containing compound and ion-exchanged water, and ion-exchanged water for forming supercritical water or subcritical water as the other constituent liquid ( Embodiment 1), or a hydrothermal reaction section having a raw material liquid container 2 (102) for containing ion-exchanged water (embodiment 2) containing a compound that reacts with a vanadium-containing compound, and a heating medium (114) for performing a hydrothermal reaction (116) A tank (109) for containing the reaction liquid after the hydrothermal reaction, a raw material liquid container 1 (105), a raw material liquid container 2 (102) and a tank (109) From the raw material liquid container 1 (105), a pipe (106), a junction (MP), and a heating part pipe (117) are connected to the flow path (pipe, 103, 106) and the vanadium-containing compound. , A pump (107) for feeding liquid to the tank (109) via the pipe (118) and the control valve (119), and the supercritical fluid stored in the raw material liquid container 2 (102) which is the other constituent liquid Ion exchange water or the like for forming water or subcritical water is supplied from the raw material liquid container 2 (102) to the pipe (103), the heating medium (113), the junction (MP), the heating section pipe (117), the pipe. (118) and a pump (104) for feeding liquid to the tank (109) via the control valve (119).

  The flow reactor (101) includes a cooling part (108) including a flow path (118) for cooling the reaction liquid containing the vanadium dioxide-containing particle precursor after the hydrothermal reaction, if necessary. Also good. Further, if necessary, it is added to the reaction liquid containing the vanadium dioxide-containing particle precursor after the hydrothermal reaction, and is mixed with the reaction liquid after the surface modifier, the pH adjuster, or the hydrothermal reaction for cooling. A pump for feeding a tank (110) for containing a cooling medium (for example, water), a surface modifier, a pH adjusting agent, a cooling medium and the like to the flow path (118) via the flow path (111). (112) may further be included.

  The surface modifier suppresses / prevents aggregation of vanadium dioxide-containing particles (or precursors), and specifically includes, for example, organosilicon compounds, organotitanium compounds, organoaluminum compounds, organozirconia compounds, surface activity. Agents, silicone oils and the like.

  Although it does not restrict | limit especially as a pH adjuster, For example, organic or inorganic acids or alkalis, such as hydrochloric acid, a sulfuric acid, nitric acid, phosphoric acid, an oxalic acid (including hydrate), ammonium hydroxide, etc. are mentioned.

  The flow type reaction apparatus (101) has heating media (113, 115) in the flow path (106) or the line of the flow path (103). In particular, the heating medium (113) disposed in the flow path (103) applies supercritical water or ion exchange water stored in the raw material liquid container 2 (102) to a predetermined temperature and pressure. Form subcritical water.

  In the above example, an example in which ion-exchanged water is used as a solvent is shown, but deaerated water can also be used as necessary.

  After completion of the hydrothermal reaction, the resulting dispersion (slurry) containing the vanadium dioxide-containing particle precursor is subjected to operations such as solid-liquid separation, washing, drying, and pulverization as necessary, and the vanadium dioxide-containing particle precursor is obtained. You can get a body.

(Baking process)
In this step, the vanadium dioxide-containing particle precursor obtained in the hydrothermal reaction step is fired in an inert gas atmosphere at a firing temperature of 300 to 600 ° C. and a firing time of 1 to 20 hours. Thereby, the vanadium dioxide containing particle | grains which have the average secondary particle diameter and heat storage amount prescribed | regulated by this invention can be obtained.

  Before firing, the vanadium dioxide-containing particle precursor may be dried or pulverized as necessary. Examples of the inert gas that can be used include nitrogen gas, argon gas, and helium gas.

  The baking apparatus used in this step is not particularly limited, and examples thereof include a muffle furnace, a tubular furnace, a tilting batch kiln, and the like.

  The firing temperature in this step is 300 to 600 ° C. When a calcination temperature is less than 300 degreeC, the crystallinity of the vanadium dioxide containing particle | grains obtained becomes low, the heat storage amount falls, and the heat storage property of a molded object falls. On the other hand, when the calcination temperature exceeds 600 ° C., the average secondary particle diameter becomes excessively large, the dispersibility of the vanadium dioxide-containing particles in the resin is deteriorated, and the heat storage property of the molded article is lowered. The firing temperature is preferably 350 to 550 ° C, more preferably 400 to 500 ° C.

  Moreover, the baking time in this process is 1 to 20 hours. When baking time is less than 1 hour, the crystallinity of the vanadium dioxide containing particle | grains obtained becomes low, a heat storage amount falls, and the heat storage property of a molded object falls. On the other hand, when the firing time exceeds 20 hours, the average secondary particle diameter of the vanadium dioxide-containing particles becomes excessively large, the dispersibility of the vanadium dioxide-containing particles in the resin is deteriorated, and the heat storage property of the molded article is lowered. . The firing time is preferably 2 to 10 hours, more preferably 4 to 6 hours.

  The firing step may be performed in multiple steps. When performing by dividing into multiple times, it is performed so that the total baking time is in the above range.

[Vanadium dioxide-containing particles]
The vanadium dioxide-containing particles obtained by the above production method have an average secondary particle diameter and a heat storage amount in a specific range, thereby being excellent in dispersibility in the resin and heat storage properties of the molded product obtained by blending with the resin. Can be improved. That is, the present invention also provides vanadium dioxide-containing particles having an average secondary particle diameter of 50 to 1000 nm and a heat storage amount of 25 to 50 J / g.

  The average secondary particle diameter of the vanadium dioxide-containing particles of the present invention is 50 to 1000 nm. If the average secondary particle diameter is 50 nm or more, it can be synthesized by the production method of the present embodiment. Moreover, if it is 1000 nm or less, it is excellent in the dispersibility of the vanadium dioxide containing particle | grains in resin, and also excellent in the heat storage property of a molded object. The average secondary particle diameter is preferably 50 to 500 nm, more preferably 70 to 100 nm.

  In addition, this average secondary particle diameter can be measured by the method as described in an Example.

  The heat storage amount of the vanadium dioxide-containing particles of the present invention is 25 to 50 J / g. When the heat storage amount is less than 25 J / g, the heat storage property of the molded body obtained by blending with the resin becomes insufficient. The heat storage amount is preferably 30 to 50 J / g, more preferably 40 to 50 J / g.

  In addition, this heat storage amount can be measured by the method as described in an Example.

  In addition, the average primary particle diameter of the vanadium dioxide-containing particles of the present invention is preferably 10 to 500 nm, and more preferably 10 to 200 nm. When the average primary particle diameter is in such a range, it can be blended more uniformly with the resin, and the heat storage property when formed into a molded body is further improved.

  In addition, this average primary particle diameter can be measured by the method as described in an Example.

  The average secondary particle size, heat storage amount, and average primary particle size of the vanadium dioxide-containing particles can be controlled by appropriately adjusting the conditions in the hydrothermal reaction step and the firing step. For example, when the firing temperature is increased, the average secondary particle diameter and average primary particle diameter of the obtained vanadium dioxide-containing particles tend to increase. Further, when the firing time is lengthened, the crystallinity of the obtained vanadium dioxide-containing particles tends to increase and the heat storage amount tends to increase, and the average secondary particle diameter and average primary particle diameter of the obtained vanadium dioxide-containing particles tend to increase. It is in.

  Furthermore, when the reaction time in the hydrothermal reaction step is increased or the reaction temperature is increased, the crystallinity of the obtained vanadium dioxide-containing particles tends to increase and the amount of heat storage tends to increase, and the average of the obtained vanadium dioxide-containing particles The secondary particle size and the average primary particle size tend to increase.

  Furthermore, the phase transition temperature of the vanadium dioxide-containing particles of the present invention is preferably 30 to 70 ° C. The phase transition temperature can be controlled by appropriately selecting the type and amount of the phase transition modifier. The phase transition temperature can be measured by the method described in the examples.

[Molded body]
The vanadium dioxide-containing particles obtained by the production method according to one aspect of the present invention or the vanadium dioxide-containing particles according to one aspect of the present invention is suitably used for a molded body obtained by blending with a resin, for example. That is, this invention provides the molded object containing vanadium dioxide containing particle | grains whose average secondary particle diameter is 50-1000 nm, and a heat storage amount is 25-50 J / g, and resin. Moreover, this invention provides the thermal storage material for resin containing the vanadium dioxide containing particle | grains of this invention.

  The resin used in the molded article of the present invention is not particularly limited, and examples thereof include polyethylene resin, polypropylene resin, polystyrene resin, rubber-modified polystyrene resin, acrylonitrile-butadiene-styrene (ABS) resin, acrylonitrile-styrene (AS) resin, Polymethyl methacrylate resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyester resin, ethylene vinyl alcohol resin, cellulose acetate resin, ionomer resin, polyacrylonitrile resin, polyamide resin, polyacetal resin, polylactic acid resin, polyphenylene ether resin Modified polyphenylene ether resin, polycarbonate resin, polysulfone resin, polyphenylene sulfide resin, polyetherimide resin, polyethersulfone resin, Thermoplastic resins such as rearylate resin, thermoplastic polyimide resin, polyamideimide resin, polyether ether ketone resin, polyketone resin, liquid crystal polyester resin, fluororesin, syndiotactic polystyrene resin, cyclic polyolefin resin, thermoplastic polyurethane resin; melamine resin And thermosetting resins such as urea resin, unsaturated polyester resin, epoxy resin, thermosetting polyimide resin, thermosetting polyurethane resin, and phenol resin. These resins can be used alone or in admixture of two or more.

  Moreover, the optical functional layer used for a thermochromic film etc. can be obtained by mixing vanadium dioxide containing particle | grains and water-soluble resin and shape | molding in a sheet form (layer form). Examples of water-soluble resins used in this case include gelatins, graft polymers of gelatin and other polymers, proteins such as albumin and casein, celluloses, sodium alginate, cellulose sulfate, dextrin, dextran, and dextran. Naturally derived materials such as sugar derivatives such as sulfates, thickening polysaccharides, polyvinyl alcohols, polyvinylpyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymers, potassium acrylate-acrylonitrile copolymers, acetic acid Acrylic resin such as vinyl-acrylic acid ester copolymer, acrylic acid-acrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid ester copolymer , Styrene-α-methyl Styrene acrylic resin such as styrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer, styrene-sodium styrene sulfonate copolymer, styrene-2-hydroxyethyl acrylate copolymer Styrene-2-hydroxyethyl acrylate-potassium styrene sulfonate copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer Examples include polymers, vinyl acetate-maleic acid ester copolymers, vinyl acetate-crotonic acid copolymers, vinyl acetate copolymers such as vinyl acetate-acrylic acid copolymers, and salts thereof.

  In addition, a water-soluble resin having an amide group can also be used, and examples thereof include polyvinylacetamide and polyacrylamide.

  The shape of the molded body is not particularly limited and can be appropriately selected depending on the use and purpose of the molded product. Examples thereof include a plate shape, a plate shape, a rod shape, a sheet shape (layer shape), a film shape, a cylindrical shape, an annular shape, a circular shape, an elliptical shape, a polygonal shape, a frame shape, a box shape, and a panel shape.

  The method for producing the molded product of the present invention is not particularly limited, but a method of molding after mixing and kneading the vanadium dioxide-containing particles and the resin may be employed.

  As a method of mixing (kneading) the vanadium dioxide-containing particles and the resin, for example, a melt kneading method using a kneader such as an extruder, a super mixer, a Banbury mixer, a kneader, a tumbler, or a kneader; a bead mill, a planetary mixer, three A wet kneading method using the present roll, plastomill and the like;

  When the wet kneading method is used, it is preferable to mix (knead) a dispersion containing vanadium dioxide-containing particles and a resin. Examples of the solvent used in the dispersion include one or more of water, ethanol, methanol, isopropanol, acetone, methyl ethyl ketone, ethyl acetate, hexane, toluene, and the like. The dispersion may contain a dispersant for dispersing the vanadium dioxide-containing particles. Further, when preparing the dispersion, a wet dispersion apparatus may be used. Since the vanadium dioxide-containing particles according to the present invention have an average secondary particle size in the above range, they are excellent in dispersibility in these solvents.

  A known method may be used as the molding method, and is not particularly limited. If a plate-shaped product is to be manufactured, an extrusion molding method is generally used, but a flat press is also possible. In addition, profile extrusion molding method, blow molding method, compression molding method, vacuum molding method, injection molding method, inflation film molding method, extrusion lamination molding method, calender molding method, sheet molding method, fiber molding method, rotational molding method, It is possible to use a melt molding method such as a coating molding method. In addition, if a sheet-like or film-like molded body is produced, a solution casting method can be used in addition to the melt molding method.

  The content of the vanadium dioxide-containing particles in the molded body is not particularly limited, but is preferably 1 to 5 parts by mass with respect to 100 parts by mass of the resin.

  The molded body may contain, if necessary, a lubricant, an antiseptic, an antifungal agent, an antistatic agent, a matting agent, a heat stabilizer, a light stabilizer, an antioxidant, a flame retardant, a crystal nucleating agent, inorganic particles, organic Various known additives such as particles, thickeners, lubricants, ultraviolet absorbers, dyes, pigments, plasticizers, antifogging agents, antiblocking agents, surfactants, dispersants, and surface modifiers may be included.

  The said molded object can be used conveniently in uses, such as a cold insulating agent, a heat insulating agent, energy storage, and exhaust heat utilization. It can also be used for thermochromic films.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. Unless otherwise specified, “%” and “part” mean “% by mass” and “part by mass”, respectively.

Example 1
<Hydrothermal reaction process>
19.0 g of vanadium oxide sulfate (IV) (VOSO ₄ ) was dissolved in ion-exchanged water to 300 mL, and while stirring this solution, 68 g of 3.0 mol / L NH ₃ aqueous solution was added as an alkali and the solution temperature was 25 Reaction solution 1 was prepared at a pH of 8.0. This reaction liquid 1 was put into an autoclave having an internal volume of 500 mL, and subjected to a hydrothermal reaction at 250 ° C. and 3.98 MPa for 8 hours to obtain a dispersion containing a vanadium dioxide-containing particle precursor.

  The obtained dispersion containing the vanadium dioxide-containing particle precursor is dried for 3 hours using an oven set at 100 ° C. to remove water, and then powdered in an agate mortar to form solid vanadium dioxide-containing particles. A precursor was obtained.

<Baking process>
The vanadium dioxide-containing particle precursor obtained above was fired under a condition of a firing temperature of 550 ° C. and a firing time of 5 hours while flowing nitrogen gas in a tilting batch kiln (manufactured by Hiroki Co., Ltd.). 1 was obtained.

(Example 2)
<Hydrothermal reaction process>
19.0 g of vanadium oxide sulfate (IV) (VOSO ₄ ) is charged into a raw material liquid container 1 (105) of the flow reactor (101) shown in FIG. 1, and dissolved in ion-exchanged water to make 300 mL. While stirring, 68 mL of 3.0 mol / L NH ₃ aqueous solution was added as an alkali to prepare a raw material liquid 1 having a pH of 8.0 at a liquid temperature of 25 ° C. On the other hand, ion exchange water was charged as the raw material liquid 2 into the raw material liquid container 2 (102) of the flow reaction apparatus 101.

  The raw material liquid 1 containing vanadium oxide sulfate (IV) and alkali is fed from the raw material liquid container 1 (105) into the flow path (106) by the pump (107), and heated at 25 ° C. with the heating medium (115). Pressurization was performed so that the condition was 30 MPa.

  On the other hand, ion exchange water as the raw material liquid 2 is fed from the raw material liquid container 2 (102) into the flow path (103) by the pump (104), and is heated by the heating medium (113) at 440 ° C. and 30 MPa. Was heated and pressurized to obtain supercritical water.

  Next, the condition that the raw material liquid 1 containing vanadium oxide (IV) oxide and an alkali and the raw material liquid 2 that is supercritical water is the raw material liquid 1: the raw material liquid 2 = 1: 4 (volume ratio) at the junction MP. The reaction solution 2 was prepared by mixing the solution and fed to the hydrothermal reaction section (116) which is a hydrothermal reaction section. In the hydrothermal reaction part (116), it sent to the heating part piping (117) arrange | positioned in the heating medium (114). The hydrothermal reaction in the heating part piping (117) was performed under the conditions of 400 ° C., 30 MPa, and a processing time (passing time) of 2 seconds. Subsequently, the reaction liquid 2 was cooled in the cooling part (118), and the dispersion liquid containing a vanadium dioxide containing particle precursor and water was prepared.

  The prepared dispersion was filtered, and the residue was washed with water and ethanol. Next, the residue is dried at 60 ° C. for 10 hours using a constant temperature dryer, further dried for 3 hours using an oven set at 100 ° C. to remove water, and then powdered in an agate mortar. A solid vanadium dioxide-containing particle precursor was obtained.

<Baking process>
The obtained vanadium dioxide-containing particle precursor was fired under a condition of a firing temperature of 450 ° C. and a firing time of 5 hours while flowing nitrogen gas in a tilting batch kiln (manufactured by Hiroki Co., Ltd.). Obtained.

(Example 3)
Vanadium dioxide-containing particles 3 were obtained in the same manner as in Example 2 except that the firing temperature in the firing step was 550 ° C.

Example 4
Together with an oxidizing vanadium sulfate (IV), vanadium tungsten = 9: 1 ammonium tungstate para pentahydrate such that (atomic _{ratio) ((NH 4) 10 W} 12 O 41 · 5H 2 O, Wako Pure Chemical Industries, Vanadium dioxide-containing particles 4 were obtained in the same manner as in Example 3 except that the product manufactured by Co., Ltd. was charged into the raw material liquid container 1 (105).

(Comparative Example 1)
Vanadium dioxide (manufactured by High-Purity Chemical Laboratory Co., Ltd.) is fired at a firing temperature of 900 ° C. and a firing time of 5 hours while flowing nitrogen gas in a tilting batch kiln (manufactured by Hiroki Co., Ltd.), and contains vanadium dioxide. Particle 5 was obtained.

(Comparative Example 2)
Vanadium dioxide-containing particles 6 were obtained in the same manner as in Comparative Example 1 except that the firing temperature was 550 ° C.

(Comparative Example 3)
Vanadium dioxide (manufactured by Kojundo Chemical Laboratory Co., Ltd.) was wet-ground for 8 hours using a paint shaker (manufactured by RED DEVIL, trade name: RED DEVIL Paint Mixer, model: Model 5410 Type 5410). Water contained in the obtained slurry was removed by freeze-drying to obtain vanadium dioxide powder having an average primary particle size of 1000 nm.

  Next, the obtained vanadium dioxide powder was fired under a condition of a firing temperature of 900 ° C. and a firing time of 5 hours while flowing nitrogen gas in a tilting batch kiln (manufactured by Hiroki Co., Ltd.). Obtained.

(Comparative Example 4)
Vanadium dioxide-containing particles 8 were obtained in the same manner as in Example 2 except that the firing step was not performed.

(Comparative Example 5)
Vanadium dioxide-containing particles 9 were obtained in the same manner as in Example 2 except that the firing temperature was 200 ° C.

(Comparative Example 6)
Vanadium dioxide-containing particles 10 were obtained in the same manner as in Example 2 except that the firing temperature was 900 ° C.

(Comparative Example 7)
Vanadium dioxide-containing particles 11 were obtained in the same manner as in Example 3 except that the firing time was 0.5 hours.

(Comparative Example 8)
Vanadium dioxide-containing particles 12 were obtained in the same manner as in Example 3 except that the firing time was 24 hours.

(Comparative Example 9)
Vanadium dioxide (manufactured by Kojundo Chemical Laboratory Co., Ltd.) was wet-ground for 8 hours using a paint shaker (manufactured by RED DEVIL, trade name: RED DEVIL Paint Mixer, model: Model 5410 Type 5410). Water contained in the obtained slurry was removed by freeze-drying to obtain vanadium dioxide powder having an average primary particle size of 88 nm.

  Next, the obtained vanadium dioxide powder was fired at a firing temperature of 500 ° C. and a firing time of 6 hours while flowing nitrogen gas in a tilting batch kiln (manufactured by Hiroki Co., Ltd.). Obtained.

(Comparative Example 10)
25 g of vanadium triisopropoxide oxide was added to 500 ml of 35% hydrogen peroxide water and stirred at 30 ° C. to obtain a vanadium-containing solution. The vanadium-containing solution was adjusted to pH 1.8 while stirring and allowed to stand at 35 ° C. for 15 hours. As a result, vanadium oxide was precipitated. As a result of SEM observation of this precipitate, it was confirmed that the precipitate had a porous structure.

  The obtained vanadium oxide was pulverized using Star Mill Lab Star Mini (manufactured by Ashizawa Finetech Co., Ltd.) and heated in a hydrogen stream at 330 ° C. for 2 hours for reduction treatment.

  Further, the vanadium oxide after the reduction treatment was wet-pulverized for 4 hours with a paint shaker (manufactured by RED DEVIL, trade name: RED DEVIL Paint Mixer, model: Model 5410 Type 5410). Water contained in the obtained slurry was removed by lyophilization to obtain vanadium dioxide powder (vanadium dioxide-containing particle precursor) having an average primary particle size of 30 nm.

  Next, the obtained vanadium dioxide powder was fired under a condition of a firing temperature of 500 ° C. and a firing time of 13 hours while flowing nitrogen gas in a tilting batch kiln (manufactured by Hiroki Co., Ltd.). Obtained.

[Evaluation]
(Average primary particle size)
The prepared vanadium dioxide-containing particles were photographed with a scanning electron microscope (manufactured by Hitachi, Ltd., Hitachi S-5000 type), and an SEM photograph (1100 nm × 950 nm) was obtained. In the obtained SEM photograph, 30 particles having the most universal size and shape are selected, the area of each particle is measured, the diameter of the circle having the same area is taken as the particle diameter, and the average value is obtained. This was made into the average primary particle diameter.

(Average secondary particle size)
Using a dynamic light scattering analyzer (Malvern, Zetasizer Nano S), an average particle size (Z average) of vanadium dioxide-containing particles (sample) is obtained by a dynamic light scattering (DLS) method. The value was defined as the average secondary particle size. The measurement conditions are as follows:
Sample concentration: 0.01% by mass
Sample refraction (RI value): 3.0
Solvent; methyl ethyl ketone Dispersant: PA-085C (manufactured by NOF Corporation) is added in an amount of 20% by mass with respect to the vanadium dioxide-containing particles.

(Phase transition temperature, heat storage)
Using a differential scanning calorimeter, differential scanning calorimetry (DSC) of vanadium dioxide-containing particles was performed under the following conditions. The peak top temperature of the endothermic peak observed at the time of temperature rise was defined as the phase transition temperature of the vanadium dioxide-containing particles. Further, the peak area of the same endothermic peak was determined, and this was defined as the heat storage amount of the vanadium dioxide-containing particles;
Scanning temperature range: -20 to 100 ° C
Temperature increase rate: 10 ° C./min Temperature decrease rate: 10 ° C./min.

(Heat storage property of molded body)
<Production of molded body>
100 parts by weight of vanadium dioxide-containing particles, 9600 parts by weight of methyl ethyl ketone (manufactured by Wako Pure Chemical Industries, Ltd., 99% special grade), and 300 parts by weight of PA-085C (manufactured by NOF Corporation) as a dispersing agent are mixed, and Nanovaita (registered) Dispersion treatment was performed using a trademark (manufactured by Yoshida Kikai Kogyo Co., Ltd.) (treatment conditions: 200 MPa, 10 pass) to obtain a vanadium dioxide-containing particle dispersion. 200 parts by mass of the obtained vanadium dioxide-containing particle dispersion, 100 parts by mass of Byron (registered trademark) 200 (Toyobo Co., Ltd.), which is an amorphous polyester resin, and methyl ethyl ketone (Wako Pure Chemical Industries, Ltd., special grade 99) %) And 700 parts by mass were kneaded at 200 ° C. for 1 hour by a kneading extrusion molding apparatus Labo Plast Mill C model (manufactured by Toyo Seiki Seisakusho Co., Ltd.).

  After kneading, it was molded into a thin plate having a length of 5 cm, a width of 5 cm, and a thickness of 0.5 cm using an injection molding machine Hand Truda (manufactured by Toyo Seiki Seisakusho Co., Ltd.) to obtain a molded body.

<Evaluation of heat storage>
The obtained molded body was heated to 100 ° C. on a hot plate, and the surface temperature of the molded body was observed with a thermography camera. The time from the start of heating until reaching 80 ° C. was recorded, and the heat storage property of the molded body was evaluated as follows. It shows that it is excellent in heat storage property, so that the time until it reaches 80 degreeC is long, and it is practical if it is (double-circle) -triangles;
◎: 70 minutes or more ○: 50 minutes or more and less than 70 minutes Δ: 30 minutes or more and less than 50 minutes ×: Less than 30 minutes.

  The production conditions and evaluation results of the vanadium dioxide-containing particles of Examples and Comparative Examples are shown in Table 1 below.

  As apparent from Table 1 above, the vanadium dioxide-containing particles of the examples whose average secondary particle diameter and heat storage amount are within the scope of the present invention improve the heat storage property of the resulting molded product when blended with the resin. I knew it was possible.

  On the other hand, the vanadium dioxide-containing particles of Comparative Examples 1 to 3, Comparative Example 6, and Comparative Example 8 have an average primary particle size that is too large, and the particles settle out during the measurement of the average secondary particle size. The secondary particle size could not be measured. In Comparative Examples 9 and 10, secondary aggregation of the vanadium dioxide-containing particles occurred, and the particles settled during the measurement of the average secondary particle size, and the average secondary particle size could not be measured. Moreover, the dispersibility in resin of the vanadium dioxide containing particle | grains of these comparative examples was also bad, and the heat storage property of the molded object deteriorated.

  Although the vanadium dioxide-containing particles of Example 1 have a relatively large average primary particle size, no sedimentation of particles occurs during measurement of the average secondary particle size, and the average secondary particle size can be measured. Moreover, the heat storage property of the molded body containing the vanadium dioxide-containing particles of Example 1 was relatively good. This is because when the vanadium dioxide-containing particles are produced by the production method of the present invention including a hydrothermal reaction step, there are more hydroxyl groups on the surface of the vanadium dioxide-containing particles than when produced by wet pulverization. It is considered that the solvent dispersibility is improved and the dispersibility in the resin is also relatively improved.

  The vanadium dioxide-containing particles of Comparative Examples 4, 5, and 7 had a low heat storage amount, and the heat storage properties of the molded bodies obtained by blending with the resin were lowered.

101 flow reactor,
102, 105 raw material liquid container,
103, 106, 111, 118 flow path (pipe),
104, 107, 112 pump,
108 cooling section,
109, 110 tanks,
113, 114, 115 heating medium,
116 Hydrothermal reaction section,
117 Heating part piping,
119 control valve,
C refrigerant,
IN heating medium inlet,
OUT Heating medium outlet,
L Line length of heating part piping,
MP junction,
TC Temperature sensor.

Claims (12)

A hydrothermal reaction step of hydrothermally reacting a reaction solution containing a vanadium-containing compound and water to obtain a vanadium dioxide-containing particle precursor; and
A firing step of firing the vanadium dioxide-containing particle precursor in an inert gas atmosphere;
A method for producing vanadium dioxide-containing particles having
The manufacturing method of vanadium dioxide containing particle | grains whose calcination temperature in the said baking process is 300-600 degreeC, and whose calcination time is 1 to 20 hours.   The said hydrothermal reaction process is a manufacturing method of the vanadium dioxide containing particle | grains of Claim 1 performed using the flow-type reaction apparatus which has a hydrothermal reaction part.   The manufacturing method of the vanadium dioxide containing particle | grains of Claim 1 or 2 whose said calcination temperature is 400-500 degreeC.   The manufacturing method of the vanadium dioxide containing particle | grains of any one of Claims 1-3 with which the said reaction liquid further contains the substance containing the element for adjusting the phase transition temperature of the said vanadium dioxide containing particle | grain.   The method for producing vanadium dioxide-containing particles according to any one of claims 1 to 4, wherein the vanadium dioxide-containing particles have an average secondary particle diameter of 50 to 1000 nm and a heat storage amount of 25 to 50 J / g.   The manufacturing method of the vanadium dioxide containing particle | grains of any one of Claims 1-5 whose average primary particle diameter of the said vanadium dioxide containing particle | grain is 10-500 nm.   Vanadium dioxide-containing particles having an average secondary particle diameter of 50 to 1000 nm and a heat storage amount of 25 to 50 J / g.   The vanadium dioxide-containing particles according to claim 7, wherein the average secondary particle diameter is 50 to 500 nm.   The vanadium dioxide containing particle | grains of Claim 7 or 8 whose average primary particle diameter is 10-500 nm.   The vanadium dioxide-containing particles according to any one of claims 7 to 9, wherein the phase transition temperature is 30 to 70 ° C.   The molded object containing the vanadium dioxide containing particle | grains and resin of any one of Claims 7-10.   The heat storage material for resin containing the vanadium dioxide containing particle | grains of any one of Claims 7-10.