Heat shielding composition, heat shielding resin molded body, heat shielding resin laminate, method for producing dispersed powder

Abstract

The objective is to provide a heat-shielding composition that includes a dispersion powder that can be converted into an aqueous dispersion using water as a dispersion medium by adding water. [Solution] A nonionic polymer dispersant and A crystal with a hexagonal crystal structure, general formula M x WO y (However, element M includes one or more elements selected from Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, and satisfies 0.1 ≤ x ≤ 1.0 and 2.0 ≤ y < 4.0) Composite tungsten oxide particles containing composite tungsten oxide, A heat-shielding composition comprising polycarbonate resin or acrylic resin.

Description

[Technical Field]

[0001] The present invention relates to a heat-shielding composition, a heat-shielding resin molded article, a heat-shielding resin laminate, and a method for producing a dispersed powder. [Background technology]

[0002] Sunlight entering through openings such as windows and doors of various buildings and vehicles contains not only visible light but also ultraviolet and infrared rays. Of the infrared rays contained in sunlight, near-infrared rays with wavelengths of 800 nm to 2500 nm are called heat rays, and when they enter through openings, they cause the temperature inside a room to rise. In recent years, there has been a surge in demand for heat-shielding substrates in the fields of window materials for various buildings and vehicles that can maintain brightness by allowing sufficient visible light in while reducing the rise in indoor temperature caused by heat rays by shielding them, and many patents related to heat-shielding substrates have been proposed.

[0003] For example, Patent Documents 1 to 3 propose a heat shielding plate in which a heat-reflective film, made by depositing metal or metal oxide onto a transparent resin film, is bonded to a transparent substrate such as glass, an acrylic plate, or a polycarbonate plate.

[0004] In addition, for example, Patent Documents 4 and 5 propose heat shielding plates and films made by kneading organic near-infrared absorbers, such as phthalocyanine compounds and anthraquinone compounds, into thermoplastic transparent resins such as polyethylene terephthalate resin, polycarbonate resin, acrylic resin, polyethylene resin, and polystyrene resin.

[0005] On the other hand, the applicant of this application has focused on hexaborides and the like that which have a large amount of free electrons, and in Patent Documents 6 to 8, has disclosed a coating liquid for forming a heat-shielding film, which is composed of hexaboride particles and the like dispersed in an organic solvent as a heat-shielding component and various binders added, and a heat-shielding film obtained by applying this coating liquid to various transparent substrates and then curing it.

[0006] In addition, the applicant of the present application disclosed in Patent Document 9 a high heat resistance masterbatch containing a thermoplastic resin, tungsten oxide fine particles and / or composite tungsten oxide fine particles having a hexagonal crystal structure, and a high heat resistance dispersant having a thermal decomposition temperature of 230°C or higher, in the range of 10 ≥ [weight of high heat resistance dispersant / (weight of tungsten oxide fine particles and / or composite tungsten oxide fine particles)] ≥ 0.5.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Patent Document 9

Summary of the Invention

Problems to be Solved by the Invention

[0008] When manufacturing the high heat resistance masterbatch described in Patent Document 9, composite tungsten oxide fine particles or the like are added to an organic solvent such as toluene together with a high heat resistance dispersant to form a dispersion liquid, and then the organic solvent is removed to obtain a dispersion powder. The high heat resistance masterbatch is manufactured by kneading the dispersion powder with a thermoplastic resin.

[0009] The high heat-resistant masterbatch disclosed in Patent Document 9 is produced using an organic solvent process, making it impossible to avoid the residue of organic solvents in the masterbatch. From the viewpoint of reducing the residue of organic solvents in the masterbatch and reducing environmental impact, there has been a demand for dispersions that do not use organic solvents as a dispersion medium, or for dispersion powders that can be made into a dispersion using water as the dispersion medium. Furthermore, since the amount of residual organic solvent can be reduced by using such dispersion powder, there has also been a demand for heat-shielding compositions containing such dispersion powder, as well as forms of heat-shielding compositions such as masterbatches, heat-shielding resin molded articles, and heat-shielding resin laminates.

[0010] One aspect of the present invention aims to provide a heat shielding composition that includes a dispersion powder which can be converted into an aqueous dispersion using water as a dispersion medium by adding water. [Means for solving the problem]

[0011] A heat-shielding composition according to one aspect of the present invention comprises a nonionic polymer dispersant and A crystal with a hexagonal crystal structure, general formula M x WO y (However, element M includes one or more elements selected from Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, and satisfies 0.1 ≤ x ≤ 1.0 and 2.0 ≤ y < 4.0) Composite tungsten oxide particles containing composite tungsten oxide, It includes polycarbonate resin or acrylic resin. [Effects of the Invention]

[0012] According to one aspect of the present invention, a heat shielding composition can be provided that includes a dispersion powder which can be converted into an aqueous dispersion using water as a dispersion medium by adding water. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is an explanatory diagram of a hybrid plasma reactor that superimposes DC plasma and high-frequency plasma. [Figure 2] Figure 2 is an explanatory diagram of a masterbatch relating to one aspect of this disclosure. [Figure 3] Figure 3 is an explanatory diagram of a heat-shielding resin laminate according to one aspect of the present disclosure. [Figure 4] Figure 4 is an explanatory diagram of a heat-shielding resin laminate according to one aspect of the present disclosure. [Modes for carrying out the invention]

[0014] Specific examples of a dispersion powder, a method for producing a dispersion powder, a heat shielding composition, a heat shielding resin molded article, and a heat shielding resin laminate according to one embodiment of this disclosure (hereinafter referred to as "this embodiment") will be described below with reference to the drawings. However, the present invention is not limited to these examples and is intended to be shown in the claims, with all modifications within the meaning and scope of equivalence to the claims being included.

[0015] [Dispersed powder, method for producing dispersed powder] The dispersed powder of this embodiment may include a nonionic polymer dispersant and composite tungsten oxide particles.

[0016] The dispersion powder of this embodiment will be described in the following order: [1] composite tungsten oxide particles, [2] method for producing composite tungsten oxide particles, [3] nonionic polymer dispersant, and [4] method for producing the dispersion powder.

[0017] [1] Composite tungsten oxide particles [1-1] About the composition Composite tungsten oxide particles have the general formula M x WO y It is preferable that the compound tungsten oxide represented by [formula] is included.

[0018] Furthermore, while the composite tungsten oxide particles may consist solely of the above-mentioned composite tungsten oxide, this does not exclude the possibility of unavoidable impurities being present.

[0019] However, the element M represented by M in the above general formula is H (hydrogen), He (helium), alkali metals, alkaline earth metals, rare earth elements, Mg (magnesium), Zr (zirconium), Cr (chromium), Mn (manganese), Fe (iron), Ru (ruthenium), Co (cobalt), Rh (rhodium), Ir (iridium), Ni (nickel), Pd (palladium), Pt (platinum), Cu (copper), Ag (silver), Au (gold), Zn (zinc), Cd (cadmium), Al (aluminum), Ga (gallium), In (indium oxide). It can be one or more elements selected from among Dium, Thallium (Tl), Silicon (Si), Germanium (Ge), Tin (Sn), Lead (Pb), Antimony (Sb), Boron (B), Fluorine (F), Phosphorus (P), Sulfur (S), Selenium (Se), Bromine (Br), Tellurium (Te), Titanium (Ti), Niobium (Nb), Vanadium (V), Molybdenum (Mo), Tantalum (Ta), Rhenium (Re), Beryllium (Be), Hafnium (Hf), Os (Osmium), Bi (Bismuth), and I (Iodine). In the general formula, W represents tungsten, O represents oxygen, and x may be 0.1 ≤ x ≤ 1.0 or 0.25 ≤ x ≤ 0.39. y may be 2.0 ≤ y < 4.0.

[0020] Alkali metal elements include Li (lithium), Na (sodium), K (potassium), Rb (rubidium), Cs (cesium), and Fr (francium). Alkaline earth metal elements include Ca (calcium), Sr (strontium), Ba (barium), and Ra (radium). Rare earth elements include Sc (scandium), Y (yttrium), La (lanthanum), Ce (cerium), Pr (praseodymium), Nd (neodymium), Pm (promethium), Sm (samarium), Eu (europium), Gd (gadolinium), Tb (terbium), Dy (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), Yb (ytterbium), and Lu (lutetium).

[0021] The above general formula M x WO yThe composite tungsten oxide shown is described below.

[0022] General formula M x WO y The elements M, x, and y within the composite tungsten oxide particles, along with their crystal structure, are closely related to the free electron density of the composite tungsten oxide particles and significantly influence the near-infrared absorption properties.

[0023] Generally, tungsten trioxide (WO3) has low near-infrared absorption properties because it does not contain effective free electrons.

[0024] By adding element M to tungsten trioxide to form a composite tungsten oxide, free electrons are generated in the composite tungsten oxide, resulting in absorption characteristics in the near-infrared region derived from these free electrons. In particular, the above composite tungsten oxide is effective as a near-infrared absorbing material that absorbs near-infrared light around a wavelength of 1000 nm, and the composite tungsten oxide maintains a chemically stable state, making it effective as a near-infrared absorbing material with excellent weather resistance.

[0025] The element M in the above general formula contained in the composite tungsten oxide particles preferably contains one or more elements selected from, for example, Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Tl, and In. This is because the inclusion of one or more elements selected from Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Tl, and In makes it easier for the composite tungsten oxide particles to adopt a hexagonal crystal structure, particularly enhancing the transmittance of light in the visible light region and improving the near-infrared shielding function. In particular, considering the ease of handling of the raw materials, it is even more preferable that element M contains one or more elements selected from, for example, Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, and Ra. In particular, if element M contains one or more elements selected from K, Rb, Cs, and Ba, the composite tungsten oxide becomes particularly likely to adopt a hexagonal crystal structure. As a result, it is particularly preferable because it enhances the transmittance of light in the visible light region and absorbs light in the near-infrared region. Element M can also be formed from only one or more elements selected from K, Rb, Cs, and Ba.

[0026] It is also possible to select and combine two or more elements as element M. In this case, even if at least one of the two or more elements contained in element M is selected from Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Tl, and In, and the remaining elements are other elements, a hexagonal crystal may still be formed.

[0027] Regarding the value of x indicating the addition amount of element M in the above general formula, if the value of x is 0.1 or more, a sufficient amount of free electrons can be generated, and particularly high near-infrared absorption characteristics can be obtained. And, the larger the addition amount of element M, the more the supply amount of free electrons increases, and the near-infrared absorption characteristics also increase, but the effect saturates when the value of x is about 1. Further, if the value of x is 1 or less, generation of an impurity phase in the composite tungsten particles can be avoided, so x is preferably 1.0 or less. x may be 0.25 ≦ x ≦ 0.39, or may be in the vicinity of 0.33. This is because the value of x theoretically calculated from the hexagonal crystal structure is 0.33, and particularly favorable optical characteristics can be obtained with the addition amounts around this value.

[0028] Regarding the value of y indicating the oxygen amount in the above general formula, it is preferably 2.0 ≦ y < 4.0, more preferably 2.2 ≦ y ≦ 3.5, still more preferably 2.6 ≦ y ≦ 3.0, and particularly preferably 2.7 ≦ y ≦ 3.0. If the value of y indicating the oxygen amount is 2.0 or more, appearance of an unintended WO2 crystal phase in the composite tungsten oxide particles can be avoided, and chemical stability as a material can be obtained, so it can be a particularly effective near-infrared absorption material.

[0029] Tungsten oxide (WO y ) in which, by making y representing the oxygen amount less than 3, a particularly sufficient amount of free electrons can be generated to enhance the absorption and reflection characteristics in the near-infrared region. M x WO y In the composite tungsten oxide represented by, the same mechanism as that of the tungsten oxide represented by WO y works. However, in the composite tungsten oxide, regarding the value of y indicating the oxygen amount, even when y = 3.0 or when the oxygen amount y exceeds 3.0 and is excessive, due to the supply of free electrons by the addition of element M, near-infrared absorption characteristics can be obtained. For this reason, y may be y < 4.0, or may be y ≦ 3.5.

[0030] If the value of y is 3.0 or less, the required amount of free electrons are generated in the composite tungsten oxide, resulting in an even more efficient near-infrared absorbing material. Therefore, y may be 3.0 or less.

[0031] Here, a typical example of a composite tungsten oxide material is Cs 0.33 WO3, Rb 0.33 WO3, K 0.33 WO3, Ba 0.33 Examples include WO3. However, as long as x and y fall within the above range, useful near-infrared shielding characteristics can be obtained without being limited to the above examples.

[0032] [1-2] About the crystal structure The composite tungsten oxide contained in the composite tungsten oxide particles may have a hexagonal, tetragonal, or cubic tungsten bronze structure, but it is effective as a near-infrared absorbing material regardless of the structure. For this reason, the crystal structure of the composite tungsten oxide contained in the composite tungsten oxide particles used in the dispersed powder of this embodiment is not particularly limited.

[0033] The absorption position of light in the near-infrared region of composite tungsten oxides tends to change depending on the crystal structure. Specifically, the absorption position in the near-infrared region shifts to longer wavelengths in tetragonal crystals compared to cubic crystals, and shifts even further to longer wavelengths in hexagonal crystals than in tetragonal crystals. In addition, in conjunction with this variation in absorption position, the absorption of light in the visible light region is lowest in hexagonal crystals, followed by tetragonal crystals, and highest in cubic crystals.

[0034] Based on the above findings, the crystal structure of the composite tungsten oxide contained in the composite tungsten oxide particles may be selected to absorb and transmit light in a predetermined wavelength range depending on the application. For example, when used in applications where it is required to transmit more light in the visible light region and absorb more light in the near-infrared region, it is preferable to use hexagonal tungsten bronze as the composite tungsten oxide contained in the composite tungsten oxide particles. For this reason, it is preferable that the composite tungsten oxide contained in the composite tungsten oxide particles has a hexagonal crystal structure. When the composite tungsten oxide has a hexagonal crystal structure, the transmittance of light in the visible light region of the composite tungsten oxide is improved, and the absorption rate of light in the near-infrared region is improved. In a hexagonal crystal structure, six octahedra formed by WO6 units are assembled to form a hexagonal void (tunnel), and element M is placed in the void to form one unit, and the structure is made up of many such units assembled together.

[0035] Regarding composite tungsten oxide particles, in order to obtain the effect of improving the transmittance of light in the visible light region and the absorption rate of light in the near-infrared region, it is preferable that the composite tungsten oxide contains the above-mentioned unit structure, but it is sufficient that it contains the unit structure, and it does not need to be crystalline. The above-mentioned unit structure refers to a structure that includes a hexagonal void formed by the aggregation of six octahedrons formed by WO6 units, and in which element M is arranged.

[0036] [1-3] Regarding the size of dispersed particles The composite tungsten oxide particles used in the dispersed powder of this embodiment absorb a large amount of light in the near-infrared region, particularly around 1000 nm in wavelength, so their transmitted color is often blue. Furthermore, the particle size of the composite tungsten oxide particles can be selected according to their intended use.

[0037] When used for applications requiring transparency, it is preferable that the composite tungsten oxide particles have a dispersed particle diameter of 800 nm or less. This is because composite tungsten oxide particles with a dispersed particle diameter of 800 nm or less do not completely block light due to scattering, thus maintaining visibility in the visible light region while simultaneously efficiently maintaining transparency. In particular, when transparency in the visible light region is important, it is preferable to further consider the scattering of light by the composite tungsten oxide particles.

[0038] Furthermore, when it is required to reduce light scattering by composite tungsten oxide particles, the dispersed particle diameter of the composite tungsten oxide particles is more preferably 200 nm or less, and even more preferably 100 nm or less. This is because if the dispersed particle diameter of the composite tungsten oxide particles is small, the scattering of light in the visible light region with wavelengths between 400 nm and 780 nm due to geometric scattering or Mie scattering is reduced. As a result of reducing the scattering of light in the visible light region, it is possible to avoid the heat-shielding resin molded body, etc., becoming cloudy like frosted glass and losing clear transparency.

[0039] When the dispersed particle diameter of the composite tungsten oxide particles is 200 nm or less, the geometric scattering or Mie scattering described above is reduced, and the region becomes Rayleigh scattering. In the Rayleigh scattering region, scattered light is proportional to the sixth power of the particle diameter, so as the dispersed particle diameter decreases, light scattering decreases and transparency improves. Furthermore, when the dispersed particle diameter is 100 nm or less, scattered light becomes very small, which is preferable. From the viewpoint of avoiding light scattering, a smaller dispersed particle diameter is preferable.

[0040] There is no particular lower limit to the dispersed particle size of composite tungsten oxide particles, but the dispersed particle size can be, for example, 1 nm or larger. A dispersed particle size of 1 nm or larger can be easily manufactured industrially.

[0041] With regard to composite tungsten oxide particles, from the viewpoint of particularly improving the transparency and weather resistance of the composite tungsten oxide particles, the dispersed particle diameter of the composite tungsten oxide particles is preferably 15 nm or more and 80 nm or less, more preferably 20 nm or more and 40 nm or less, and even more preferably 30 nm or more and 40 nm or less.

[0042] [2] Method for producing composite tungsten oxide particles The method for producing composite tungsten oxide particles described above is not particularly limited. Composite tungsten oxide particles can be produced, for example, by solid-phase reaction or gas-phase reaction. Various properties of composite tungsten oxide particles can be easily controlled by the conditions under which they are produced. For this reason, preliminary tests can be conducted to select production conditions in order to produce composite tungsten oxide particles with desired properties. Examples of such production conditions include the temperature (firing temperature) used to produce the composite tungsten oxide particles, the production time (firing time), the production atmosphere (firing atmosphere), the form of the precursor raw material, the annealing treatment after production, and the doping of impurity elements.

[0043] The following describes an example of a method for producing composite tungsten oxide particles.

[0044] [2-1] Manufacturing method using the solid-state method A method for producing composite tungsten oxide particles may include, for example, a heat treatment step in which the starting material is heat-treated in an inert gas atmosphere or a reducing gas atmosphere.

[0045] A method for producing composite tungsten oxide particles may include an oxidation treatment step after a heat treatment step, in which an oxidation treatment is further performed.

[0046] The following describes each step. (Heat treatment process) The starting materials used in the heat treatment process may include tungsten-containing raw materials that serve as a source of tungsten.

[0047] The tungsten raw material may include one or more selected from, for example, tungstic acid, tungsten trioxide powder, tungsten dioxide powder, tungsten oxide hydrate, tungsten hexachloride powder, ammonium tungstate powder, tungsten oxide hydrate powder, tungsten compound powder, and metallic tungsten powder.

[0048] As hydrated tungsten oxide, for example, hydrated tungsten oxide powder obtained by dissolving tungsten hexachloride in alcohol and then drying it, or hydrated tungsten oxide powder obtained by dissolving tungsten hexachloride in alcohol, adding water to precipitate it, and then drying it can be used.

[0049] The tungsten compound powder may be a powder obtained by drying an aqueous solution of ammonium tungstate.

[0050] The tungsten raw material may include a solution containing one or more of the above-mentioned powder materials.

[0051] When manufacturing composite tungsten oxide particles, if the starting material is a solution, the elements contained in the starting material can be easily and uniformly mixed. For this reason, it is more preferable to use a solution such as an aqueous solution of ammonium tungstate or a tungsten hexachloride solution as the tungsten raw material.

[0052] The starting materials may also include element M raw materials containing element M, which serve as a source of element M.

[0053] The element M raw material may include one or more selected elements, such as element M in its elemental form or compounds containing element M.

[0054] The starting material may be a mixture of tungsten raw material and element M raw material.

[0055] In order to produce starting materials in which each component is uniformly mixed at the molecular level, it is preferable to mix each raw material in the form of a solution. Therefore, it is preferable that the element M raw material containing element M is soluble in a solvent such as water or an organic solvent. For example, the element M raw material can be one or more selected from tungstates, chlorides, nitrates, sulfates, oxalates, oxides, carbonates, hydroxides, etc., that contain element M, but is not limited to these, and any material that can be dissolved in solution can be suitably used.

[0056] In the heat treatment process, a heat treatment temperature of 650°C or higher is preferred in an inert gas atmosphere. Starting materials heat-treated at 650°C or higher have sufficient near-infrared absorption capacity and are efficient as near-infrared absorbing materials. The upper limit of the heat treatment temperature in an inert gas atmosphere is not particularly limited, but it can be, for example, 1200°C or lower.

[0057] In other words, the heat treatment conditions in an inert gas atmosphere can be set to a temperature between 650°C and 1200°C.

[0058] Inert gases such as Ar (argon) and N2 (nitrogen) can be used.

[0059] In the heat treatment process, when heat treatment is performed in a reducing gas atmosphere, it is preferable to first heat-treat the starting material in a reducing gas atmosphere at a temperature of 300°C to 1000°C, and then heat-treat it in an inert gas atmosphere at a temperature of 650°C to 1200°C.

[0060] The reducing gas used in the reducing gas atmosphere is not particularly limited, but H2 (hydrogen) is preferred. When H2 is used as the reducing gas, the composition of the reducing gas atmosphere is preferably a mixture of an inert gas such as Ar or N2 with H2 at a volume ratio of 0.1% or more, and more preferably 0.2% or more. If H2 is at a volume ratio of 0.1% or more, reduction can be carried out efficiently.

[0061] There is no particular upper limit to the H2 concentration in a reducing gas atmosphere, but it can be set to, for example, 100% or less by volume. (Oxidation process) In the oxidation treatment process, the composite tungsten oxide particles obtained in the heat treatment process can be oxidized under mild conditions.

[0062] The oxygen source gas used in the oxidation process is not particularly limited, but one or more selected from oxygen, air, and water vapor is preferred. The concentration of the oxygen source can be appropriately selected according to the heat treatment temperature and the amount of material to be heat treated, and is not particularly limited. The heat treatment temperature can also be appropriately selected according to the amount of material to be heat treated, and is not particularly limited, but for example, it is preferably between 400°C and 850°C. (Other processes) A method for producing composite tungsten oxide particles may also include a surface treatment step in which the surface is treated with at least one compound selected from silane compounds, titanium compounds, aluminum compounds, and zirconia compounds. By coating the surface of the composite tungsten oxide particles with a compound containing one or more elements selected from Si, Ti, Al, and Zr, the weather resistance can be improved.

[0063] [2-2] Manufacturing method by gas phase method As an example of a method for producing composite tungsten oxide particles using a gas-phase method, a method for producing composite tungsten oxide particles using a plasma method will be described.

[0064] (Materials used in the thermal plasma method) When synthesizing composite tungsten oxide particles using the thermal plasma method, the raw materials include a mixture of tungsten raw material and element M raw material, or a mixture of general formula M x1 WO y1 A composite tungsten oxide precursor represented by [formula] can be used. The same materials as those described in the solid-phase manufacturing method described above can be suitably used as the tungsten raw material and element M raw material.

[0065] When preparing a raw material mixture of a tungsten raw material and an element M raw material as starting materials, they can be mixed according to the target composition. That is, each raw material can be formulated and mixed so that the ratio of element M to tungsten in the raw material mixture of the tungsten raw material and the element M raw material is equal to the ratio of x to y in the general formula of the target composite tungsten oxide.

[0066] Also, when using a composite tungsten oxide precursor represented by the general formula M x1 WO y1 as a starting material, it is preferable that x1 and y1 in the general formula satisfy 0.001 ≦ x1 ≦ 1.0 and 2.0 < y1.

[0067] The general formula M x1 WO y1 The composite tungsten oxide precursor represented by can be synthesized, for example, by the solid-phase method described above.

[0068] (Configuration example of plasma device) As the plasma used for producing the composite tungsten oxide particles, for example, any one of direct current arc plasma, high-frequency plasma, microwave plasma, low-frequency alternating current plasma, or a superposition of these plasmas, or plasma generated by an electrical method in which a magnetic field is applied to direct current plasma, plasma generated by irradiation with a high-power laser, or plasma generated by a high-power electron beam or ion beam can be used.

[0069] However, in any case of using any plasma, it is a thermal plasma having a high-temperature part of 10000K or more and 15000K or less, and particularly preferably a plasma capable of controlling the generation time of fine particles.

[0070] The raw material supplied into the thermal plasma having a high-temperature part instantaneously evaporates at the high-temperature part. Then, the evaporated raw material condenses in the process of reaching the plasma afterglow part and is rapidly solidified outside the plasma flame to produce composite tungsten oxide particles.

[0071] Below, as an example of a plasma device, we will explain using a hybrid plasma reactor, which is a combination of a DC plasma device and a high-frequency plasma device as shown in Figure 1.

[0072] The apparatus shown in Figure 1 is a hybrid plasma reactor 10 that superimposes a DC plasma device and a high-frequency plasma device.

[0073] The hybrid plasma reactor 10 includes a water-cooled quartz double tube 11 and a reaction vessel 12 connected to the water-cooled quartz double tube 11. A vacuum evacuation device 13 is also connected to the reaction vessel 12.

[0074] A DC plasma torch 14 is provided above the water-cooled quartz double tube 11, and a plasma generation gas supply port 15 is provided on the DC plasma torch 14.

[0075] The system is configured to supply a sheath gas for generating high-frequency plasma and protecting the quartz tube along the inner wall of the water-cooled quartz double tube 11 outside the plasma region, and a sheath gas inlet 16 is provided on the upper flange of the water-cooled quartz double tube 11.

[0076] A water-cooled copper coil 17 for generating high-frequency plasma is arranged around the water-cooled quartz double tube 11.

[0077] A raw material powder carrier gas supply port 18 is provided near the DC plasma torch 14 and is connected by piping to a raw material powder supply device 19 that supplies the raw material powder.

[0078] The plasma generation gas supply port 15, the sheath gas inlet 16, and the raw material powder supply device 19 can be connected to a gas supply device 200 by piping, so that a predetermined gas can be supplied to each component from the gas supply device 200. In addition, supply ports can be provided for components other than those mentioned above and connected to the gas supply device 200 to cool the components inside the device or to control the atmosphere to a predetermined level, as needed.

[0079] (Example of manufacturing conditions for composite tungsten oxide particles using a plasma device) An example configuration for a method of producing composite tungsten oxide particles using a hybrid plasma reactor 10 will be described.

[0080] First, the reaction system, consisting of the water-cooled quartz double tube 11 and the reaction vessel 12, is evacuated using the vacuum evacuation device 13. The degree of vacuum at this time is not particularly limited, but it can be reduced to, for example, about 0.1 Pa. After evacuating the reaction system, argon gas can be supplied from the gas supply device 200 to fill the reaction system with argon gas. For example, it is preferable to have an argon gas flow system at 1 atmosphere within the reaction system.

[0081] Furthermore, plasma gas can then be supplied into the reaction vessel 12. The plasma gas is not particularly limited, but for example, any gas selected from argon gas, a mixture of argon and helium (Ar-He mixed gas), a mixture of argon and nitrogen (Ar-N2 mixed gas), neon, helium, or xenon can be used.

[0082] The plasma gas supply flow rate is not particularly limited, but for example, it can be introduced from the plasma generation gas supply port 15 at a flow rate of preferably 3 L / min to 30 L / min, more preferably 3 L / min to 15 L / min. Then, a DC plasma can be generated.

[0083] On the other hand, outside the plasma region, a sheath gas for generating high-frequency plasma and protecting the quartz tube can be supplied in a swirling manner from the sheath gas inlet 16 along the inner wall of the water-cooled quartz double tube 11. The type of sheath gas and the supply speed are not particularly limited, but for example, high-frequency plasma can be generated by flowing argon gas at a rate of 20 L / min to 50 L / min and hydrogen gas at a rate of 1 L / min to 5 L / min.

[0084] Furthermore, a high-frequency power supply can be applied to the water-cooled copper coil 17 for generating high-frequency plasma. The conditions of the high-frequency power supply are not particularly limited, but for example, a high-frequency power supply with a frequency of about 4 MHz and a power output of 15 kW to 50 kW can be applied.

[0085] After generating the hybrid plasma, the raw materials can be introduced using a carrier gas through the raw material powder carrier gas supply port 18 via the raw material powder supply device 19. The carrier gas is not particularly limited, but for example, a mixed gas consisting of argon gas at a rate of 1 L / min to 8 L / min and oxygen gas at a rate of 0.001 L / min to 0.8 L / min can be used.

[0086] The reaction is carried out by introducing a raw material mixture or a composite tungsten oxide precursor, which serves as the starting material, into the plasma. The supply rate of the starting material powder from the carrier gas supply port 18 is not particularly limited, but it is preferably supplied at a rate of 1 g / min to 50 g / min, and more preferably 1 g / min to 20 g / min.

[0087] By setting the feed rate of the starting material to 50 g / min or less, the proportion of the starting material passing through the center of the plasma flame can be sufficiently high, suppressing the proportion of unreacted materials and intermediate products, and increasing the production rate of the desired composite tungsten oxide particles. Furthermore, productivity can be increased by setting the feed rate of the starting material to 1 g / min or more.

[0088] The starting material supplied into the plasma instantly evaporates within the plasma and, through a condensation process, can generate composite tungsten oxide particles with an average primary particle diameter of 100 nm or less.

[0089] Furthermore, the particle size of the composite tungsten oxide particles obtained by the manufacturing method of this embodiment can be easily controlled by the plasma output, plasma flow rate, and the amount of raw material powder supplied.

[0090] After the reaction, the resulting composite tungsten oxide particles accumulate in the reaction vessel 12 and can be recovered.

[0091] Furthermore, the composite tungsten oxide particles obtained by the manufacturing method described above can also be surface-treated and coated. Since the surface treatment process has already been explained, it will be omitted here.

[0092] (Crushing and dispersion processing) Composite tungsten oxide particles obtained by solid-phase or gas-phase synthesis methods may undergo aggregation, which can result in the dispersion particle size of the composite tungsten oxide particles falling outside the desired range.

[0093] Thus, if the characteristics of the obtained composite tungsten oxide particles, such as particle size, are not within the desired range, the composite tungsten oxide particles can be added to a liquid medium and subjected to grinding and dispersion treatment. After the grinding and dispersion treatment, the liquid medium can be removed by drying and the composite tungsten oxide particles can be recovered.

[0094] As for the drying equipment, one or more types selected from the following are preferably used, but are not limited to these, as they can perform one or more operations selected from heating and reduced pressure, and allow for easy mixing and recovery of particles: air dryers, universal mixers, ribbon mixers, vacuum fluidized bed dryers, vibrating fluidized bed dryers, freeze dryers, Ribocones, rotary kilns, spray dryers, Palcon dryers, etc.

[0095] [3] Nonionic polymer dispersants Nonionic polymer dispersants are used to hydrophobize the surface of composite tungsten oxide particles. The nonionic polymer dispersant can be selected to match the dispersion system, which is a combination of composite tungsten oxide particles, a dispersion medium, and a coating resin raw material. However, since the composite tungsten oxide particle dispersion according to one aspect of this disclosure uses water as a solvent, a water-soluble polymer dispersant containing one or more functional groups selected from pyrrolidone groups and amide groups is preferred. An example of a nonionic polymer dispersant is polyvinylpyrrolidone.

[0096] The proportion of nonionic polymer dispersant added to the composite tungsten oxide particles is not particularly limited and can be selected according to the required properties. The weight ratio of the nonionic polymer dispersant to the composite tungsten oxide particles may be, for example, in the range of 0.08 ≤ (weight of nonionic polymer dispersant / weight of composite tungsten oxide particles) < 3.0. By setting the weight ratio of the nonionic polymer dispersant to the composite tungsten oxide particles within the above range, it is possible to produce heat-shielding resin molded articles and heat-shielding resin laminates that exhibit particularly excellent heat-shielding functions. Furthermore, by setting the weight ratio of the nonionic polymer dispersant to the composite tungsten oxide particles within the above range, the content of composite tungsten oxide particles in the dispersed powder can be made sufficiently high. Therefore, it becomes possible to easily adjust the concentration of the dispersed powder when manufacturing heat-shielding resin molded articles and heat-shielding resin laminates.

[0097] As already described, the dispersed powder of this embodiment may include a nonionic polymer dispersant and composite tungsten oxide particles. At least a portion of the nonionic polymer dispersant may be disposed on the particle surface of the composite tungsten oxide particles. The nonionic polymer dispersant may modify the particle surface of the composite tungsten oxide particles.

[0098] [4] Method for producing dispersed powder The method for producing the dispersed powder according to this embodiment may include a dispersion liquid preparation step and a dispersed powder preparation step. Each step will be described below.

[0099] (Dispersion liquid preparation process) In the dispersion preparation process, the composite tungsten oxide particles, a nonionic polymer dispersant, and water (which serves as the dispersion medium) are mixed to prepare the dispersion. Furthermore, from the viewpoint of reducing the particle size of the composite tungsten oxide particles and ensuring uniform dispersion within the dispersion, the composite tungsten oxide particles may also be ground and dispersed during the dispersion preparation process.

[0100] Water is used as the dispersion medium from the perspective of reducing environmental impact.

[0101] Since the composite tungsten oxide particles have already been explained, the explanation will be omitted. As a nonionic polymer dispersant, a water-soluble polymer dispersant having one or more functional groups selected from pyrrolidone groups and amino groups can be used. Since the nonionic polymer dispersant has also already been explained, the explanation will be omitted.

[0102] The mixing method used when mixing and grinding the composite tungsten oxide particles, nonionic polymer dispersant, and water is not particularly limited, but one or more selected from, for example, a bead mill, ball mill, sand mill, paint shaker, ultrasonic homogenizer, etc. can be used. In particular, as a mixing method, it is preferable to use a media stirring mill such as a bead mill, ball mill, sand mill, or paint shaker that uses a media such as beads, balls, or Ottawa sand. This is because using a media stirring mill allows the composite tungsten oxide particles to be dispersed to the desired particle size, especially in a short time, which is preferable from the viewpoint of productivity and suppression of impurity contamination.

[0103] The degree of grinding of the composite tungsten oxide particles in the dispersion preparation step is not particularly limited. In the dispersion preparation step, for example, grinding and dispersion treatment may be performed until the dispersed particle size of the composite tungsten oxide particles contained in the dispersion is preferably 15 nm to 80 nm, more preferably 20 nm to 40 nm, and even more preferably 30 nm to 40 nm. By grinding the composite tungsten oxide particles until the dispersed particle size is within the above range, the composite tungsten oxide particles can particularly exhibit transparency in visible light and high weather resistance.

[0104] By keeping the weight ratio of the nonionic polymer dispersant to the composite tungsten oxide particles within the range described above, and by grinding the composite tungsten oxide particles to the above-mentioned particle size, the transparency and weather resistance of the composite tungsten oxide particles in terms of visible light can be further enhanced.

[0105] The concentration of composite tungsten oxide particles in the dispersion (composite tungsten oxide particle dispersion) is not particularly limited, but may be, for example, 5% by mass or more and 50% by mass or less. By setting the concentration of composite tungsten oxide particles to 5% by mass or more, the amount of liquid medium such as water that needs to be removed when preparing the dispersion powder can be reduced, and manufacturing costs can also be reduced. Furthermore, if the concentration of composite tungsten oxide particles is 50% by mass or less, particle aggregation will not occur and the viscosity of the liquid will not increase, making it easier to handle.

[0106] (Dispersed powder preparation process) In the dispersion powder preparation process, water can be removed from the dispersion liquid to prepare the dispersion powder.

[0107] The dispersion powder preparation process involves removing water from the dispersion liquid, and can therefore also be called a drying process.

[0108] The method for removing water from the dispersion in the dispersion preparation process is not particularly limited, but for example, a method of vacuum drying of the dispersion may be used. Specifically, the dispersion is vacuum dried while stirring using a vacuum drying apparatus to separate the dispersion powder from the water. Examples of apparatus used for vacuum drying include vacuum stirring type dryers, but any apparatus having the above function is acceptable and is not particularly limited. Furthermore, the pressure of the vacuum in the drying process is not particularly limited and can be selected arbitrarily.

[0109] In the dispersion powder preparation process, using a vacuum drying method to remove water is preferable because it improves the efficiency of water removal and prevents the dispersion powder from being exposed to high temperatures for extended periods, thus reducing the likelihood of aggregation of the dispersed composite tungsten oxide particles.

[0110] [Heat ray shielding composition] (1) Regarding heat shielding compositions The heat shielding composition of this embodiment may include a dispersed powder according to one aspect of the present disclosure and a thermoplastic resin.

[0111] The heat shielding composition of this embodiment includes, for example, a nonionic polymer dispersant and a polymer having a hexagonal crystal structure, with general formula M xWO y The material may contain composite tungsten oxide particles, which are composite tungsten oxides represented by [formula], and a thermoplastic resin.

[0112] The heat shielding composition of this embodiment may be a mixture of dispersed powder and a thermoplastic resin.

[0113] The heat-shielding composition of this embodiment includes both a mixture of a nonionic polymer dispersant, a composite tungsten oxide, and a thermoplastic resin, and a masterbatch, which is a molded body of the mixture. The mixture refers to the state in which each raw material is simply mixed before the components such as the thermoplastic resin are melted and mixed. The masterbatch is a molded body before it is molded into the shape of the final product, and can be called an intermediate molded body, for example, a pellet-shaped molded body.

[0114] In the following explanation, the term "mixture" may refer to the mixture of a nonionic polymer dispersant, a composite tungsten oxide, and a thermoplastic resin, while the term "masterbatch" may refer to the masterbatch, which is the molded product of this mixture.

[0115] As described above, the heat shielding composition of this embodiment may also include a masterbatch, which is a molded body, as one aspect. That is, the heat shielding composition of this embodiment may be a masterbatch, but is not limited to this form.

[0116] A masterbatch, which is one embodiment of the heat-shielding composition of this embodiment, can be used as a raw material for various molded articles and is not particularly limited in its use, but it can be used as a masterbatch for manufacturing heat-shielding resin molded articles. When the heat-shielding composition of this embodiment is in the form of a masterbatch, the heat-shielding composition in a mixed state can be melted and kneaded and processed into pellets (granules) of, for example, 1 mm to 5 mm. By processing it into the above shape, a masterbatch that is easy to melt and process can be made.

[0117] In a masterbatch that is one embodiment of the heat shielding composition of this embodiment, the thermoplastic resin can be arranged to cover, for example, composite tungsten oxide particles, including, i.e., to enclose them.

[0118] Figure 2 shows a schematic diagram of a masterbatch, which is one embodiment of the heat shielding composition of this embodiment. As schematically shown in Figure 2, the masterbatch 20, which is one embodiment of the heat shielding composition of this embodiment, may include, for example, composite tungsten oxide particles 21 and a thermoplastic resin 22, and the composite tungsten oxide particles 21 may be arranged in the thermoplastic resin 22. It is preferable that the composite tungsten oxide particles 21 are dispersed in the thermoplastic resin 22.

[0119] Figure 2 is a schematic diagram, and the masterbatch, which is one embodiment of the heat shielding composition of this embodiment, is not limited to this form. For example, in Figure 2, the composite tungsten oxide particles 21 are represented by circles and described as spherical particles, but the shape of the composite tungsten oxide particles 21 is not limited to this form and can have any shape. The composite tungsten oxide particles 21 may also have a coating on their surface, for example. Although not shown in Figure 2, as previously described, the masterbatch 20 of this embodiment further includes a nonionic polymer dispersant. The nonionic polymer dispersant can be placed on the surface of the composite tungsten oxide particles 21 and can modify the surface of the composite tungsten oxide particles 21. Furthermore, the masterbatch 20, which is one embodiment of the heat shielding composition of this embodiment, may also include other additives as needed.

[0120] (Regarding thermoplastic resins) Since nonionic polymer dispersants, composite tungsten oxides, and dispersed powders have already been explained, we will now discuss thermoplastic resins.

[0121] As the thermoplastic resin, a transparent thermoplastic resin with high light transmittance in the visible light region can be suitably used. For example, a thermoplastic resin that has a visible light transmittance of 50% or more as described in JIS R 3106 (2019) and a haze of 30% or less as described in JIS K 7105 (1981) when molded into a 3 mm thick plate can be suitably used.

[0122] Specifically, the thermoplastic resin can be one or more selected from, for example, acrylic resin, polycarbonate resin, polyetherimide resin, polyester resin, polystyrene resin, polyethersulfone resin, fluoropolymer resin, and polyolefin resin.

[0123] The heat-shielding composition of this embodiment can be used as a raw material for heat-shielding resin molded articles, etc. Therefore, when the purpose is to apply heat-shielding resin molded articles to window materials for various buildings and vehicles, the thermoplastic resin is more preferably one or more selected from acrylic resin, polycarbonate resin, polyetherimide resin, and fluororesin, considering transparency, impact resistance, weather resistance, etc. The thermoplastic resin is even more preferably polycarbonate resin or acrylic resin.

[0124] Aromatic polycarbonates can be suitably used as the polycarbonate resin. Examples of aromatic polycarbonates include polymers obtained by known methods such as interfacial polymerization, melt polymerization, or solid-phase polymerization from one or more divalent phenolic compounds, such as 2,2-bis(4-hydroxyphenyl)propane and 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, and a carbonate precursor, such as phosgene or diphenyl carbonate.

[0125] Examples of acrylic resins include polymers or copolymers that primarily use methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate as raw materials, and optionally use acrylic acid esters having alkyl groups with 1 to 8 carbon atoms, vinyl acetate, styrene, acrylonitrile, methacrylonitrile, etc., as copolymer components. Furthermore, acrylic resins that have been polymerized in multiple stages can also be used.

[0126] The thermoplastic resin may be one or more types selected from polycarbonate resin and acrylic resin, or it may be polycarbonate resin or acrylic resin.

[0127] (2) Method for manufacturing heat shielding composition The heat-shielding composition of this embodiment can be manufactured by mixing a dispersion powder and a thermoplastic resin. Since it is preferable that the dispersion powder is dispersed in the thermoplastic resin, it is preferable to mix the two so that the dispersion powder can be dispersed in the thermoplastic resin.

[0128] Therefore, the method for producing the heat-shielding composition of this embodiment may include a mixing step of mixing a dispersed powder with a thermoplastic resin. After the mixing step, a heat-shielding composition in the form of a mixture can be obtained.

[0129] Furthermore, a method for producing a masterbatch, which is one embodiment of the heat shielding composition of this embodiment, can be prepared by melting and kneading the heat shielding composition in a mixed state using a melt kneader and processing it into pellets. In addition, a mixing step may be performed in the melt kneader as well, or the heat shielding composition in a mixed state may be supplied to the melt kneader to produce a heat shielding composition in the form of a masterbatch.

[0130] The temperature during melt-mixing can be maintained at a temperature that prevents the decomposition of the thermoplastic resin contained in the heat-shielding composition.

[0131] Suitable kneaders for melt-kneading include single-screw extruders and twin-screw extruders.

[0132] Masterbatch pellets can be obtained by cutting the most common molten extruded strands. Therefore, their shapes can be cylindrical or prismatic. Alternatively, a so-called hot-cut method, where the molten extruded material is cut directly, is also possible. In this case, the masterbatch is generally nearly spherical.

[0133] The masterbatch, which is one embodiment of the heat-shielding composition of this embodiment, can take any form or shape. However, it is preferable that the masterbatch has the same or similar size and shape as the thermoplastic resin used to dilute the masterbatch when molding the heat-shielding resin molded article.

[0134] The heat-shielding composition mixture and masterbatch of this embodiment can use a dispersion or dispersion powder according to one aspect of this disclosure as a raw material, thereby reducing the content of organic solvents. The heat-shielding composition mixture and masterbatch of this embodiment can, for example, have a residual organic solvent content of 0.1% by mass or less, or even 0% by mass.

[0135] The method for producing a masterbatch, which is one embodiment of the heat shielding composition of this embodiment, is not limited to a method using the heat shielding composition in a mixed state. For example, a dispersion can be prepared by first using a method such as a bead mill, ball mill, sand mill, or ultrasonic dispersion to disperse the dispersed powder according to one embodiment of this disclosure in any dispersion medium such as water.

[0136] Next, the dispersion, the thermoplastic resin powder or pellets, and optionally a dispersant or other additives can be uniformly melt-mixed using a kneader while removing the dispersion medium from the dispersion to prepare a masterbatch in which composite tungsten oxide particles are dispersed in the thermoplastic resin.

[0137] Furthermore, it is also possible to obtain a heat-shielding composition in a mixed state by simply removing the dispersion medium without melting and mixing.

[0138] As a mixing machine, one or more types selected from, for example, ribbon blenders, tumblers, Nauter mixers, Henschel mixers, super mixers, planetary mixers, etc., and Banbury mixers, kneaders, rolls, kneader-ruders, single-screw extruders, twin-screw extruders, etc., may be used. It is preferable to maintain the temperature during mixing at a temperature that does not cause the thermoplastic resin used to decompose.

[0139] Alternatively, a masterbatch can be prepared in which composite tungsten oxide particles are dispersed in a thermoplastic resin by uniformly melting and mixing the dispersed powder with granular or pelletized thermoplastic resin and, if necessary, other additives.

[0140] In addition, a method for manufacturing a masterbatch may be used in which dispersed powder, thermoplastic resin powder or pellets, and other additives as needed are uniformly melted and mixed.

[0141] The dispersion method is not limited to these methods, as long as the composite tungsten oxide particles are dispersed in the thermoplastic resin. [Heat-shielding resin molded body, heat-shielding resin laminate] Next, the heat-shielding resin molded body of this embodiment will be described.

[0142] The heat-shielding resin molded article of this embodiment is a molded article containing a heat-shielding composition according to one aspect of the present disclosure.

[0143] The heat-shielding resin molded article of this embodiment can also be manufactured by molding a heat-shielding composition according to one aspect of the present disclosure. That is, the heat-shielding resin molded article of this embodiment can also be a molded article made of a heat-shielding composition.

[0144] Furthermore, the heat-shielding resin molded article of this embodiment may also contain a heat-shielding composition and a thermoplastic resin. The thermoplastic resin is used to dilute the heat-shielding composition and adjust the concentration of the composite tungsten oxide particles contained therein. For this reason, it is preferable that the thermoplastic resin is the same type of resin as the thermoplastic resin contained in the heat-shielding composition, or a different type of resin that is compatible with it. That is, it is preferable that the thermoplastic resin is a resin that can be mixed without separation when kneaded with the heat-shielding composition. If it is necessary to distinguish it from the thermoplastic resin contained in the heat-shielding composition, the thermoplastic resin contained in the heat-shielding composition may be referred to as the first thermoplastic resin. Also, the thermoplastic resin added when manufacturing the heat-shielding resin molded article may be referred to as the second thermoplastic resin.

[0145] The heat-shielding resin molded article of this embodiment is obtained by molding a heat-shielding composition, or a mixture of a heat-shielding composition and a thermoplastic resin, into a predetermined shape.

[0146] The heat-shielding resin molded article of this embodiment may be manufactured using either a heat-shielding composition in a mixture state or a heat-shielding composition in a masterbatch state.

[0147] In the heat-shielding resin molded article of this embodiment, the composite tungsten oxide particles may be sufficiently dispersed in the heat-shielding resin molded article. By sufficiently dispersing the composite tungsten oxide particles in the heat-shielding resin molded article, the heat-shielding resin molded article of this embodiment ensures good visible light transmittance and exhibits excellent near-infrared shielding function.

[0148] The heat shielding performance is determined by the amount of composite tungsten oxide particles per unit area of ​​the heat-shielding resin molded body. Therefore, if a predetermined amount of composite tungsten oxide particles is dispersed per unit area of ​​the heat-shielding resin molded body, it will exhibit the desired heat shielding performance commensurate with the amount of composite tungsten oxide particles, regardless of the thickness of the heat-shielding resin molded body. Thus, it is preferable to determine the amount of composite tungsten oxide particles in the resin of a heat-shielding resin molded body according to the optical properties and mechanical properties required of the heat-shielding resin molded body. Even if the amount of composite tungsten oxide particles per unit area satisfies the heat shielding characteristics, as the heat-shielding resin molded body becomes thinner, the amount per unit volume increases, reducing the wear strength and impact resistance of the heat-shielding resin molded body. In addition, composite tungsten oxide particles may rise to the surface of the heat-shielding resin molded body, potentially impairing its appearance. Therefore, even when the heat-shielding resin molded body is thin, specifically when the thickness is around 20 μm to 30 μm, from the viewpoint of producing a heat-shielding resin molded body with excellent mechanical properties and appearance, the content of composite tungsten oxide particles is such that the heat-shielding resin molded body is 1 m 2 The amount is preferably 45g or less per unit, more preferably 20g or less, and even more preferably 1g or less. On the other hand, the content of composite tungsten oxide particles is 1m of heat-shielding resin molded body. 2 It may be 0.05g or more per unit. Heat-shielding resin molded body 1m 2 By setting the content of composite tungsten oxide particles per unit to 0.05g or more, the heat shielding properties of the heat-shielding resin molded body can be particularly enhanced.

[0149] In other words, the heat-shielding resin molded body of this embodiment has a composite tungsten oxide particle content of 1 m 2 The amount per serving may be between 0.05g and 45g, between 0.05g and 20g, or between 0.05g and 1g.

[0150] The shape of the heat-shielding resin molded body in this embodiment is not particularly limited and can be molded into any shape as needed, for example, it can be molded into a flat or curved shape.

[0151] The thickness of the heat-shielding resin molded body in this embodiment is not particularly limited and can be adjusted to any thickness as needed. Furthermore, the resin sheet formed in a flat shape can be molded into any shape, such as a curved surface or a sphere, by post-processing.

[0152] Any method can be used to mold the heat-shielding resin molded article of this embodiment, such as injection molding, extrusion molding, compression molding, or rotational molding. In particular, methods for obtaining the molded article by injection molding or by extrusion molding can be preferably used as the molding method for the heat-shielding resin molded article of this embodiment.

[0153] As a method for obtaining plate-shaped or film-shaped molded products by extrusion molding, the molten thermoplastic resin extruded using an extruder such as a T-die is taken up while being cooled by a cooling roll.

[0154] The heat-shielding resin molded body of this embodiment may be used as a structural material such as window glass or arcade, using only the heat-shielding resin molded body itself.

[0155] Furthermore, the heat-shielding resin molded body of this embodiment can be laminated to other substrates such as inorganic glass, resin glass, or resin film in any manner and used as a structural material as an integrated heat-shielding resin laminate. For example, by laminating a heat-shielding resin molded body, which has been pre-formed into a film shape, onto inorganic glass using a thermal lamination method, a heat-shielding resin laminate with heat-shielding and shatterproof functions can be obtained.

[0156] Furthermore, by using methods such as thermal lamination, co-extrusion, press molding, and injection molding, it is possible to create a heat-shielding resin laminate by laminating and integrating a heat-shielding resin molded body with another molded body at the same time as molding the resin molded body. This heat-shielding resin laminate can be used as a more useful structural material by effectively utilizing the advantages of each molded body while compensating for their respective disadvantages.

[0157] In other words, the heat-shielding resin laminate of this embodiment may have a base material and a heat-shielding resin molded body according to one aspect of the present disclosure, laminated on the base material.

[0158] Specifically, as shown in Figure 3, a schematic cross-sectional view along the lamination direction of the substrate and the heat-shielding resin molded body, the heat-shielding resin laminate 30 may have a substrate 31 and a heat-shielding resin molded body 32. The heat-shielding resin molded body 32 can be placed on at least one surface 31A of the substrate 31.

[0159] The heat-shielding resin laminate of this embodiment is not limited to the form shown in Figure 3. For example, as shown in Figure 4, a schematic cross-sectional view along the lamination direction of the substrate and the heat-shielding resin molded body, the heat-shielding resin laminate 40 can have a plurality of transparent molded bodies 411, 412 which are the substrate, and a heat-shielding resin molded body 42. The heat-shielding resin molded body 42, which is the interlayer, can be placed between the plurality of transparent molded bodies 411, 412. In Figure 4, an example is shown in which there are two transparent molded bodies 411, 412, but the embodiment is not limited to this form.

[0160] The shape of the transparent molded body used in the heat-shielding resin laminate is not particularly limited and can be selected according to the shape required for the heat-shielding resin laminate. The shape of the transparent molded body may be a board shape, a sheet shape, or a film shape, as shown in Figures 3 and 4. If the near-heat-shielding resin laminate has multiple transparent molded bodies, their thickness and shape may differ.

[0161] The material of the transparent molded body is not particularly limited, but one or more types selected from glass, resin sheets, resin boards, resin films, etc., can preferably be used. A transparent molded body is a material that transmits light in the visible light range, and the degree of light transmission in the visible light range can be arbitrarily selected depending on the application of the heat-shielding resin laminate. The glass may be either inorganic glass or resin glass.

[0162] When a transparent molded body includes one or more types selected from resin sheets, resin boards, resin films, etc., the resin used is not particularly limited and can be selected according to the required characteristics such as the surface condition and durability of the sheet, board, or film. Examples of the above-mentioned resins include polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetylcellulose and triacetylcellulose, polycarbonate polymers, acrylic polymers such as polymethyl methacrylate, styrene polymers such as polystyrene and acrylonitrile-styrene copolymers, olefin polymers such as polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure, and ethylene-propylene copolymers, vinyl chloride polymers, amide polymers such as aromatic polyamides, imide polymers, sulfone polymers, polyethersulfone polymers, polyetheretherketone polymers, polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers, vinyl butyral polymers, arylate polymers, polyoxymethylene polymers, epoxy polymers, and transparent polymers such as various binary and ternary copolymers, graft copolymers, and blends thereof. In particular, polyester-based biaxially oriented films such as polyethylene terephthalate, polybutylene terephthalate, or polyethylene-2,6-naphthalate are preferred in terms of mechanical properties, optical properties, heat resistance, and cost-effectiveness. The polyester-based biaxially oriented film may also be a copolymerized polyester.

[0163] The transparent molded body may also contain various additives, such as particles with infrared absorption properties, as needed.

[0164] The heat-shielding resin molded articles and heat-shielding resin laminates of this embodiment described above have a molded article containing a heat-shielding composition according to one aspect of the present disclosure.

[0165] A heat-shielding composition according to one aspect of this disclosure comprises a nonionic polymer dispersant, a thermoplastic resin, and composite tungsten oxide particles. Therefore, aggregation of the composite tungsten oxide particles can be prevented when molding the heat-shielding composition. As a result, the heat-shielding resin molded article and the heat-shielding resin laminate of this embodiment can exhibit good light transmittance in the visible light region and excellent heat-shielding function.

[0166] The heat-shielding resin molded article and the heat-shielding resin laminate of this embodiment can use a dispersion or dispersion powder according to one aspect of the present disclosure as a raw material, thereby reducing the content of organic solvents. The heat-shielding resin molded article and the heat-shielding resin laminate of this embodiment can have a residual organic solvent content of, for example, 0.1% by mass or less, or even 0% by mass. [Examples]

[0167] The present invention will be described more specifically below with reference to examples, but the present invention is not limited thereto. [1] Evaluation method The visible light transmittance and solar transmittance of the fabricated heat-shielding resin molded body were measured using a Hitachi, Ltd. UH-4150 spectrophotometer. [2] Conditions and results of the examples and comparative examples [Example 1] 17.7g of Cs2CO3 was dissolved in 39.9g of water, and this was added to 82.3g of H2WO4. The mixture was dried in a vacuum dryer while stirring. The resulting dried powder was calcined at 550°C for 1 hour under a 5 vol% H2 gas atmosphere with N2 gas as a carrier, and then calcined again at 800°C for 1 hour under an N2 gas atmosphere to obtain particle a. Chemical analysis revealed that particle a has the composition of Cs 0.33 WO 2.45 The measured powder X-ray diffraction pattern was hexagonal Cs 0.3 The X-ray diffraction pattern matched that of WO3, confirming that it has a hexagonal crystal structure.

[0168] Next, a composite tungsten oxide particle dispersion (solution a) was prepared by weighing 15% by mass of particle a, 12% by mass of polyvinylpyrrolidone, and 73% by mass of water, and grinding and dispersing them in a paint shaker containing 0.3 mmφ ZrO2 beads for 6 hours (dispersion preparation step).

[0169] The dispersed particle size of the composite tungsten oxide particles in liquid a was measured to be 32.3 nm. The dispersed particle size was measured using the ELS-8000 manufactured by Otsuka Electronics Co., Ltd., which is based on the principle of dynamic light scattering. Subsequently, water was removed from liquid A using a large vacuum grinder to obtain a dispersed powder of composite tungsten oxide particles (dispersed powder a) (dispersed powder preparation step).

[0170] It has been confirmed that the dispersion powder a prepared in this embodiment, as well as the dispersion powders prepared and used in the following other embodiments, disperse the composite tungsten oxide particles in water and become an aqueous dispersion again when water is added. Furthermore, in the case of dispersion powder a prepared in this embodiment, as well as the dispersion powders prepared in the following other embodiments, water is used as the dispersion medium when preparing the raw material dispersion. Therefore, the content of organic solvents in the heat shielding composition, masterbatch, and heat shielding resin molded article prepared using this dispersion powder can be reduced.

[0171] The obtained dispersed powder a was added to polycarbonate resin powder, which is a thermoplastic resin, so that the composite tungsten oxide particle concentration was 0.08% by mass, and the mixture was uniformly mixed in a blender to prepare a heat-shielding composition in a mixed state.

[0172] The prepared heat-shielding composition was melt-kneaded in a twin-screw extruder and extruded to a thickness of 1 mm using a T-die. Subsequently, a heat-pressing was performed to obtain a heat-shielding resin molded article with a thickness of 0.8 mm in which composite tungsten oxide particles were uniformly dispersed throughout the resin.

[0173] Obtained heat-shielding resin molded body 1m 2The amount of composite tungsten oxide particles per unit was 0.77 g. The calculation results are shown in the "Composite Tungsten Oxide Particle Content" column of Table 1. However, the density of the heat-shielding resin molded article containing polycarbonate resin as the thermoplastic resin was assumed to be 1.2 g / cm³. 3 The calculation was performed as follows: Specifically, the mass of composite tungsten oxide particles contained in the heat-shielding resin molded sample was determined from the volume, density, and composite tungsten oxide particle concentration of the heat-shielding resin molded sample. Then, the mass of composite tungsten oxide particles contained in the heat-shielding resin molded sample was divided by the thickness of the heat-shielding resin molded sample and the area of ​​the intersecting surface, resulting in the mass of composite tungsten oxide particles contained in the heat-shielding resin molded sample per 1 m 2 The content of composite tungsten oxide particles per unit was calculated. The heat-shielding resin molded body can also be described as a molded product of the masterbatch prepared in this example. The same applies to Examples 2 to 6 below.

[0174] When the optical properties of this heat-shielding resin molded body were measured, the solar radiation transmittance was 42.5% when the visible light transmittance was 74.8%, as shown in Table 1. [Example 2] 8.8g of Cs2CO3 was dissolved in 16.5g of water, and this was added to 450g of H2WO and dried in a vacuum dryer while stirring. The resulting dried powder was calcined at 570°C for 1 hour under a 5 vol% H2 gas atmosphere with N2 gas as a carrier, then calcined at 800°C for 1 hour under a 1 vol% air atmosphere with N2 gas as a carrier, and finally calcined at 820°C for 0.5 hours under an N2 gas atmosphere to obtain particle b. Chemical analysis revealed that particle b has a composition of Cs 0.27 WO 2.86 The measured powder X-ray diffraction pattern was hexagonal Cs 0.3 The X-ray diffraction pattern matched that of WO3, confirming that it has a hexagonal crystal structure.

[0175] Except for using particle b, the composite tungsten oxide particle dispersion powder (dispersion powder b) according to Example 2 was obtained under the same conditions and procedures as in Example 1. Furthermore, the heat-shielding composition and heat-shielding resin molded article according to Example 2 were prepared and their optical properties were evaluated under the same conditions as in Example 1.

[0176] The dispersed particle size of the composite tungsten oxide particles in liquid b, which is a dispersion of composite tungsten oxide particles prepared during the process of preparing dispersed powder b, was 32.5 nm.

[0177] Obtained heat-shielding resin molded body 1m 2 The amount of composite tungsten oxide particles per unit was 0.77 g.

[0178] When the optical properties of the heat-shielding resin molded body according to Example 2 were measured, the solar radiation transmittance was 43.6% when the visible light transmittance was 76.0%, as shown in Table 1. [Example 3] 17.7g of Cs2CO3 was dissolved in 39.9g of water, and this was added to 82.3g of H2WO4. The mixture was dried in a vacuum dryer while stirring to obtain dried powder c.

[0179] Using the hybrid plasma reactor 10 shown in Figure 1, which superimposes DC plasma and high-frequency plasma, the reaction system was evacuated to approximately 0.1 Pa (approximately 0.001 torr) using a vacuum pump, and then completely replaced with argon gas to create a 1 atm argon flow system. Subsequently, 8 L / min of argon gas was flowed from the plasma generation gas supply port 15 to generate DC plasma. The DC power input at this time was 6 kW. Furthermore, 40 L / min of argon gas and 3 L / min of hydrogen gas were flowed in a spiral manner from the sheath gas inlet 16 along the inner wall of the water-cooled quartz double tube 11 as gases for high-frequency plasma generation and protection of the quartz tube, and high-frequency plasma was generated. The high-frequency power input at this time was 45 kW. After generating the hybrid plasma in this way, a mixed gas of 3 L / min of argon gas and 0.15 L / min of oxygen gas was used as a carrier gas, and the obtained dried powder c was supplied into the plasma at a rate of 2 g / min from the raw material powder supply device. As a result, the raw material instantly evaporated, condensed in the plasma tail flame, and was pulverized to obtain particle c. Chemical analysis of particle c revealed that its composition is Cs 0.31 WO 3.21 The measured powder X-ray diffraction pattern was hexagonal Cs 0.3 The X-ray diffraction pattern matched that of WO3, confirming that it has a hexagonal crystal structure.

[0180] Except for using particle c, the composite tungsten oxide particle dispersion powder (dispersion powder c) according to Example 3 was obtained under the same conditions and procedures as in Example 1. Furthermore, the heat-shielding composition and heat-shielding resin molded article according to Example 3 were prepared and their optical properties were evaluated under the same conditions as in Example 1.

[0181] The dispersed particle size of the composite tungsten oxide particles in liquid c, which is a dispersion of composite tungsten oxide particles prepared during the process of preparing dispersed powder c, was 24.6 nm.

[0182] Obtained heat-shielding resin molded body 1m 2 The amount of composite tungsten oxide particles per unit was 0.77 g.

[0183] When the optical properties of the heat-shielding resin molded body according to Example 3 were measured, the solar radiation transmittance was 44.3% when the visible light transmittance was 75.2%, as shown in Table 1. [Example 4] Except for the fact that K2CO3 and H2WO4 were weighed in a molar ratio of K / W = 0.33 during raw material preparation and used in place of Cs2CO3 and H2WO4, the composite tungsten oxide particles d according to Example 4 were obtained under the same conditions and procedures as in Example 1. Chemical analysis of particle d revealed that its composition was K 0.33 WO 2.45 The measured powder X-ray diffraction pattern was hexagonal K 0.3 The X-ray diffraction pattern matched that of WO3, confirming that it has a hexagonal crystal structure.

[0184] Except for using particle d, the composite tungsten oxide particle dispersion powder (dispersion powder d) according to Example 4 was obtained under the same conditions and procedures as in Example 1. Furthermore, the heat shielding composition and heat shielding resin molded article according to Example 4 were prepared and their optical properties were evaluated under the same conditions as in Example 1.

[0185] The dispersed particle size of the composite tungsten oxide particles in liquid d, which is a dispersion of composite tungsten oxide particles prepared during the process of preparing dispersed powder d, was 32.1 nm.

[0186] Obtained heat-shielding resin molded body 1m 2 The amount of composite tungsten oxide particles per unit was 0.77 g.

[0187] When the optical properties of the heat-shielding resin molded body according to Example 4 were measured, the solar radiation transmittance was 44.7% when the visible light transmittance was 74.0%, as shown in Table 1. [Example 5] Except for the fact that Rb2CO3 and H2WO4 were weighed in a molar ratio of Rb / W = 0.33 during raw material preparation and used in place of Cs2CO3 and H2WO4, the composite tungsten oxide particles e according to Example 5 were obtained under the same conditions and procedures as in Example 1. Chemical analysis of particle e revealed that its composition was Rb 0.33 WO 2.45The measured powder X-ray diffraction pattern was hexagonal Rb 0.33 WO 2.45 The X-ray diffraction pattern matched that of the sample, confirming that it has a hexagonal crystal structure.

[0188] Except for using particle e, a composite tungsten oxide particle dispersion powder (dispersion powder e) according to Example 5 was obtained under the same conditions and procedures as in Example 1. Furthermore, a heat-shielding composition and a heat-shielding resin molded article according to Example 5 were prepared, and their optical properties were evaluated under the same conditions as in Example 1.

[0189] The dispersed particle size of the composite tungsten oxide particles in liquid e, which is a dispersion of composite tungsten oxide particles prepared during the process of preparing dispersed powder e, was 32.5 nm.

[0190] Obtained heat-shielding resin molded body 1m 2 The amount of composite tungsten oxide particles per unit was 0.77 g.

[0191] When the optical properties of the heat-shielding resin molded body according to Example 5 were measured, the solar radiation transmittance was 44.1% when the visible light transmittance was 75.9%, as shown in Table 1. [Example 6] Except for the fact that BaCO3 and H2WO4 were weighed in a molar ratio of Ba / W = 0.33 during raw material preparation and used in place of Cs2CO3 and H2WO4, the composite tungsten oxide particles f according to Example 6 were obtained under the same conditions and procedures as in Example 1. Chemical analysis of particle f revealed that its composition was Ba 0.33 WO 2.45 The measured powder X-ray diffraction pattern was hexagonal Ba 0.3 The X-ray diffraction pattern matched that of WO3, confirming that it has a hexagonal crystal structure.

[0192] Except for using particle f, a composite tungsten oxide particle dispersion powder (dispersion powder f) according to Example 6 was obtained under the same conditions and procedures as in Example 1. Furthermore, a heat-shielding composition and a heat-shielding resin molded article according to Example 6 were prepared, and their optical properties were evaluated under the same conditions as in Example 1.

[0193] The particle size of the composite tungsten oxide particles dispersed in liquid f, which is a dispersion of composite tungsten oxide particles prepared during the process of preparing the dispersed powder f, was 32.6 nm.

[0194] Obtained heat-shielding resin molded body 1m 2 The amount of composite tungsten oxide particles per unit was 0.77 g.

[0195] When the optical properties of the heat-shielding resin molded body according to Example 6 were measured, the solar radiation transmittance was 45.4% when the visible light transmittance was 74.0%, as shown in Table 1. [Example 7] Except for using acrylic resin as the thermoplastic resin, a heat-shielding resin molded article according to Example 7 was obtained under the same conditions and procedures as in Example 1.

[0196] Obtained heat-shielding resin molded body 1m 2 The content of composite tungsten oxide particles per unit was 0.76 g. However, the density of the heat-shielding resin molded article containing acrylic resin as the thermoplastic resin was 1.18 g / cm³. 3 It was calculated as follows.

[0197] When the optical properties of the heat-shielding resin molded body according to Example 7 were measured, the solar radiation transmittance was 45.0% when the visible light transmittance was 76.8%, as shown in Table 1. [Comparative Example 1] Except for not using polyvinylpyrrolidone, the dispersion powder (dispersion powder a1), heat shielding composition, and heat shielding resin molded article for Comparative Example 1 were prepared under the same conditions and procedures as in Example 1, and the optical properties were evaluated under the same conditions as in Example 1.

[0198] The particle size of the composite tungsten oxide particles dispersed in liquid a1, which is a dispersion of composite tungsten oxide particles prepared during the process of preparing dispersed powder a1, was 32.5 nm.

[0199] Obtained heat-shielding resin molded body 1m 2The amount of composite tungsten oxide particles per unit was 0.77 g.

[0200] When the optical properties of the heat-shielding resin molded article relating to Comparative Example 1 were measured, the solar radiation transmittance was 61.9% when the visible light transmittance was 78.2%, as shown in Table 1.

[0201] [Table 1]

[0202] 〔evaluation〕 According to the results shown in Table 1, it was confirmed that the heat-shielding resin molded articles of Examples 1 to 7 had a visible light transmittance of 74.0% or more and a solar radiation transmittance of 45.5% or less.

[0203] Furthermore, in the heat-shielding compositions and heat-shielding resin molded articles of Examples 1 to 7, water is used as the dispersion medium when preparing the dispersion, and no organic solvent is used, thus the proportion of organic solvents introduced during the manufacturing process can be sufficiently reduced.

[0204] On the other hand, while the heat-shielding resin molded body of Comparative Example 1 had a visible light transmittance of 76.0% or higher, its solar radiation transmittance exceeded 61%, which was confirmed to be high.

[0205] Examples of embodiments of the present disclosure are as follows: <1> Nonionic polymer dispersant, A crystal with a hexagonal crystal structure, general formula M x WO y (However, element M includes one or more elements selected from Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, and satisfies 0.1 ≤ x ≤ 1.0 and 2.0 ≤ y < 4.0) Composite tungsten oxide particles containing composite tungsten oxide, A heat-shielding composition comprising polycarbonate resin or acrylic resin. <2> The element M includes one or more elements selected from K, Rb, Cs, and Ba. <1> The heat-shielding composition described above. <3> It is a masterbatch. <1> or <2> The heat-shielding composition described above. <4> <1> from <3> A heat-shielding resin molded article, which is a molded article containing the heat-shielding composition described in any of the above. <5> The content of the composite tungsten oxide particles is such that the heat-shielding resin molded body is 1 m 2 The amount per serving is between 0.05g and 45g. <4> A heat-shielding resin molded body as described above. <6> Substrate and Laminated on the aforementioned substrate <4> or <5> A heat-shielding resin laminate comprising a heat-shielding resin molded body as described in [reference]. <7> A crystal with a hexagonal crystal structure, general formula M x WO y A dispersion preparation step involves mixing composite tungsten oxide particles, which contain a composite tungsten oxide represented by (where element M is one or more elements selected from Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, and satisfies 0.1 ≤ x ≤ 1.0 and 2.0 ≤ y < 4.0), with a nonionic polymer dispersant and water, then grinding and dispersing to prepare a dispersion. A method for producing a dispersion powder, comprising a dispersion powder preparation step of removing the water from the dispersion to prepare a dispersion powder. <8> In the dispersion preparation step, the grinding and dispersion process is performed until the particle size of the composite tungsten oxide particles contained in the dispersion is between 15 nm and 80 nm. <7> A method for producing the dispersed powder described above. [Explanation of symbols]

[0206] 10 Hybrid Plasma Reactor 11 Water-cooled quartz double tube 12 Reaction vessel 13. Vacuum Exhaust System 14. DC Plasma Torch 15. Gas supply port for plasma generation 16. Sheathed gas inlet 17 Water-cooled copper coil 18. Raw material powder carrier gas supply port 19 Raw material powder supply device 200 Gas supply device 20 Masterbatch 21. Composite tungsten oxide particles 22 Thermoplastic resin 30 Heat-shielding resin laminate 31 Base material 32 Heat ray shielding resin molded body 40 Heat-shielding resin laminate 411 Transparent molded body 412 Transparent molded body 42 Heat ray shielding resin molded body

Claims

1. Nonionic polymer dispersant, A crystal with a hexagonal crystal structure, general formula M ｘ WO ｙ (However, element M includes one or more elements selected from Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, and satisfies 0.1 ≤ x ≤ 1.0 and 2.0 ≤ y < 4.0) Composite tungsten oxide particles containing composite tungsten oxide, A heat-shielding composition comprising polycarbonate resin or acrylic resin.

2. The heat shielding composition according to claim 1, wherein the element M comprises one or more elements selected from K, Rb, Cs, and Ba.

3. A heat shielding composition according to claim 1 or claim 2, which is a masterbatch.

4. A heat-shielding resin molded article, which is a molded article containing the heat-shielding composition described in claim 1 or claim 2.

5. The content of the composite tungsten oxide particles is such that the heat-shielding resin molded body 1 m ２ A heat-shielding resin molded article according to claim 4, wherein the amount per unit is 0.05 g or more and 45 g or less.

6. Substrate and A heat-shielding resin laminate comprising a heat-shielding resin molded body according to claim 4 laminated on the substrate.

7. A crystal with a hexagonal crystal structure, general formula M ｘ WO ｙ A dispersion preparation step involves mixing composite tungsten oxide particles, which contain a composite tungsten oxide represented by (where element M is one or more elements selected from Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, and satisfies 0.1 ≤ x ≤ 1.0 and 2.0 ≤ y < 4.0), with a nonionic polymer dispersant and water, then grinding and dispersing to prepare a dispersion. A method for producing a dispersion powder, comprising a dispersion powder preparation step of removing the water from the dispersion to prepare a dispersion powder.

8. The method for producing dispersed powder according to claim 7, wherein the dispersion preparation step involves performing the grinding and dispersion process until the dispersed particle size of the composite tungsten oxide particles contained in the dispersion is 15 nm or more and 80 nm or less.

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