Dispersion powder, method for producing same, heat-ray-shielding resin molded article, and heat-ray-shielding laminate

Abstract

Provided are: a dispersed powder containing composite tungsten oxide fine particles which are represented by general formula MxWOy, have a hexagonal crystal structure, have a crystallite diameter of 15-80 nm (inclusive), and have been surface-modified with an acrylic dispersant, and a heat-ray-shielding resin molded article and a heat-ray-shielding laminate which are produced using the dispersed powder; the weight ratio of the dispersant to the composite tungsten oxide microparticles is 0.3 < = (weight of dispersant / weight of composite tungsten oxide microparticles) lt; and 3.0 is within the range of 0 to 3.0.

Description

Technical Field

[0001] This invention relates to a dispersion powder applicable to the manufacture of heat-shielding resin molded bodies with high weather resistance, a method for manufacturing the same, a heat-shielding resin molded body with high weather resistance using the dispersion powder, and a heat-shielding laminate with high weather resistance. Background Technology

[0002] Sunlight entering through openings such as windows and doors of various buildings and vehicles contains ultraviolet and infrared rays in addition to visible light. Near-infrared rays with wavelengths of 800-2500 nm, which are part of the infrared radiation, are called heat rays and contribute to increased indoor temperatures by entering through these openings. To address this issue, in recent years, there has been a surge in demand for heat-shielding substrates that can effectively allow visible light in while shielding against heat rays and maintaining brightness while suppressing indoor temperature increases. Numerous patents have been filed regarding heat-shielding substrates.

[0003] For example, Patent Documents 1-3 proposed heat-reflective films made by vapor-depositing metals or metal oxides onto transparent resin films and then bonding them to transparent substrates such as glass, acrylic sheets, and polycarbonate sheets to form heat-shielding plates. However, the heat-reflective films in these heat-shielding plates are very expensive and require complex processes such as bonding, resulting in high costs. Furthermore, due to poor adhesion between the transparent substrate and the heat-reflective film, the film may peel off over time. In addition, many heat-shielding plates have been proposed that are made by directly vapor-depositing metals or metal oxides onto the surface of transparent substrates. However, manufacturing these heat-shielding plates requires high-vacuum, high-precision air control equipment, resulting in poor mass production capabilities and a lack of versatility.

[0004] Furthermore, patent documents 4 and 5, for example, propose heat-shielding plates and films incorporating 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. However, to adequately shield heat rays, a large amount of near-infrared absorber must be incorporated into these heat-shielding plates and films, which leads to a reduction in visible light transmittance. Moreover, because organic compounds are used as near-infrared absorbers, their weather resistance is poor when applied to window materials in buildings or vehicles constantly exposed to direct sunlight, making them potentially unsuitable.

[0005] Against this technological background, the applicant focuses on hexaborides that retain a large number of free electrons. Patent documents 6 to 8 disclose a coating liquid for forming a heat-wire shielding film by dispersing hexaborides as a heat-wire shielding component in an organic solvent and adding various adhesives, and a heat-wire shielding film obtained by coating the coating liquid onto various transparent substrates and then curing it.

[0006] However, these inventions are based on the premise that the hexaboride particles, which are the heat shielding component, are dispersed in an organic solvent. Therefore, the coating liquid for forming the heat shielding film is treated as a hazardous material under fire prevention laws, and its transportation is subject to various restrictions, resulting in high transportation costs.

[0007] Furthermore, when the dispersion of hexaboride particles, which serve as the heat shielding component, in an organic solvent is stored for an extended period of time, the particles are prone to agglomeration due to Brownian motion, which can sometimes lead to the formation of precipitates.

[0008] Furthermore, when molding transparent resin materials by incorporating hexaboride microparticles, since the hexaboride microparticles are dispersed in an organic solvent, it is necessary to remove the organic solvent and uniformly incorporate the hexaboride microparticles into the transparent resin material. Therefore, there is a technical problem where the equipment and processes used become complex and may not be the optimal method.

[0009] Furthermore, the applicant disclosed a high heat-resistant masterbatch in Patent Document 9, which comprises a thermoplastic resin, tungsten oxide microparticles and / or composite tungsten oxide microparticles having a hexagonal crystal structure, and a high heat-resistant dispersant with a thermal decomposition temperature of 230°C or higher, and is in the range of 10 ≥ [weight of high heat-resistant dispersant / (weight of tungsten oxide microparticles and / or composite tungsten oxide microparticles)] ≥ 0.5.

[0010] Existing technical documents

[0011] Patent documents

[0012] Patent Document 1: Japanese Patent Application Publication No. 61-277437

[0013] Patent Document 2: Japanese Patent Application Publication No. 10-146919

[0014] Patent Document 3: Japanese Patent Application Publication No. 2001-179887

[0015] Patent Document 4: Japanese Patent Application Publication No. 6-256541

[0016] Patent Document 5: Japanese Patent Application Publication No. 6-264050

[0017] Patent Document 6: Japanese Patent Application Publication No. 11-181336

[0018] Patent Document 7: Japanese Patent Application Publication No. 2000-96034

[0019] Patent Document 8: Japanese Patent Application Publication No. 2000-169765

[0020] Patent Document 9: Japanese Patent Application Publication No. 2008-024902 Summary of the Invention

[0021] The technical problem solved by the invention

[0022] However, in the high heat-resistant masterbatch described in Patent Document 9, a large amount of high heat-resistant dispersant is required to disperse the tungsten oxide particles and / or composite tungsten oxide particles, which serve as heat-shielding particles, in the thermoplastic resin. Therefore, the proportion of the heat-shielding particles in the particle dispersion is low, and their content has room for improvement. Furthermore, Patent Document 9 does not describe weather resistance, leaving room for further research.

[0023] The present invention was made under the above-described conditions, and the technical problem to be solved is to provide a heat-shielding resin molded body and a heat-shielding laminate with excellent weather resistance, high transmittance in the visible light region and excellent heat-shielding function, and to provide a dispersing powder for manufacturing them.

[0024] Technical means to solve the problem

[0025] Under the above circumstances, the inventors conducted research and came up with the following: a dispersion powder with a large concentration adjustment amount (balance) and a method for manufacturing the same, a heat-shielding resin molded body with high weather resistance using the dispersion powder, and a heat-shielding laminate with high weather resistance, thereby completing the present invention.

[0026] That is, the first invention of the present invention is a dispersing powder comprising composite tungsten oxide microparticles, the composite tungsten oxide microparticles being represented by the general formula MxWOy, having a hexagonal crystal structure, a crystallite size of 15 nm or more and 80 nm or less, and being surface-modified with an acrylic dispersant.

[0027] Wherein, element M is one or more elements selected from groups 1, 2, and 13 of the periodic table, where 0.1 ≤ x ≤ 1.0, 2.0 ≤ y < 4.0.

[0028] The weight ratio of the dispersant to the composite tungsten oxide particles is in the range of 0.3 ≤ (weight of dispersant / weight of composite tungsten oxide particles) < 3.0.

[0029] The second invention is the dispersible powder described in the first invention, wherein...

[0030] The acrylic dispersant has acidic functional groups as its functional groups.

[0031] The third invention is the dispersible powder described in the first or second invention, wherein,

[0032] The M element contained in the composite tungsten oxide particles is selected from at least one of Cs, Rb, K, Tl, and Ba.

[0033] The fourth invention is a method for manufacturing a dispersible powder, wherein,

[0034] By adding composite tungsten oxide microparticles with a hexagonal crystal structure (represented by the general formula MxWOy) and an acrylic dispersant to an organic solvent, followed by pulverization and dispersion treatment, a dispersion of the composite tungsten oxide microparticles with a crystallite size of 15 nm or more and 80 nm or less is produced.

[0035] The organic solvent is removed from the dispersion to produce a dispersion powder in which the weight ratio of the dispersant to the composite tungsten oxide particles is in the range of 0.3 ≤ (weight of dispersant / weight of composite tungsten oxide particles) < 3.0.

[0036] Among them, element M is one or more elements selected from groups 1, 2, and 13 of the periodic table, with 0.1≤x≤1.0 and 2.0≤y<4.0.

[0037] The fifth invention is a heat-shielding resin molded body obtained by diluting and mixing the dispersion powder described in the first or second invention with a thermoplastic resin molding material and molding it into a given shape.

[0038] The sixth invention is the heat-shielding resin molded body described in the fifth invention, wherein...

[0039] The thermoplastic resin molding material is a polycarbonate resin or an acrylic resin.

[0040] The seventh invention is a heat-wire shielding laminate, wherein...

[0041] The heat-shielding resin molded body described in the fifth invention is laminated with other molded bodies.

[0042] Invention Effects

[0043] The dispersion powder of the present invention is diluted and mixed with a thermoplastic resin molding material, and then further processed by known methods such as extrusion molding, injection molding, and compression molding to obtain a heat-shielding resin molded body with high weather resistance in any shape, such as a film. By applying the obtained heat-shielding resin molded body with high weather resistance to applications such as windows, carports, and arcades in automobiles and buildings, incident solar energy can be blocked, reducing cooling load and stuffiness, and contributing to energy conservation, thus exhibiting high environmental benefits. Detailed Implementation

[0044] The dispersing powder of the present invention is composed of composite tungsten oxide microparticles, which are represented by the general formula MxWOy (where M is one or more elements selected from Groups 1, 2, and 13 of the periodic table, 0.1≤x≤1.0, 2.0≤y<4.0) after surface modification with an acrylic dispersant, and have a hexagonal crystal structure. The heat wire shielding resin molded body and heat wire shielding laminate of the present invention are manufactured using this dispersing powder.

[0045] The dispersion powder, the heat-shielding resin molded body with high weather resistance, and the heat-shielding laminate with high weather resistance of the present invention will be described below in the following order.

[0046] 1) Composite tungsten oxide microparticles used in the dispersion powder

[0047] 2) Method for manufacturing composite tungsten oxide microparticles used in the dispersion powder

[0048] 3) Dispersants used in dispersing powders

[0049] 4) Method for manufacturing the composite tungsten oxide microparticle dispersion used in the dispersing powder

[0050] 5) Method for manufacturing dispersing powder

[0051] 6) Thermoplastic resin used in hot wire shielding resin molded bodies

[0052] 7) Methods for dispersing powder into thermoplastic resin

[0053] 8) Manufacturing method of hot wire shielding resin molded body and hot wire shielding laminate

[0054] 1) Composite tungsten oxide microparticles used in the dispersion powder

[0055] The composite tungsten oxide microparticles used as a thermal shielding material in the dispersion powder of this invention exhibit a predominantly blue hue due to their significant absorption of near-infrared light, particularly light near 1000 nm wavelengths. Furthermore, the particle size of this near-infrared shielding material can be appropriately selected based on its intended use.

[0056] Firstly, in applications where transparency is maintained, the composite tungsten oxide microparticles preferably have a dispersed particle size of less than 800 nm. This is because a dispersed particle size of less than 800 nm will not completely block light due to scattering, thus maintaining visual recognizability in the visible light region while efficiently preserving transparency. Especially when transparency in the visible light region is of paramount importance, further consideration is given to scattering caused by the particles.

[0057] Furthermore, when minimizing scattering caused by these particles, the dispersed particle size of the composite tungsten oxide microparticles is preferably 200 nm or less, and more preferably 100 nm or less. The reason for this is that if the dispersed particle size is small, the scattering of light in the visible light region (400 nm to 780 nm) caused by geometric scattering or Mie scattering is reduced. This is because the reduction in light scattering prevents the near-thermal shielding resin molded body from becoming like frosted glass, thus avoiding the loss of clear transparency. In other words, if the dispersed particle size is 200 nm or less, the aforementioned geometric scattering or Mie scattering decreases, entering the Rayleigh scattering region. This is because in this Rayleigh scattering region, the scattered light is proportional to the sixth power of the particle size; therefore, as the dispersed particle size decreases, scattering decreases, and transparency increases. Furthermore, when the dispersed particle size is 100 nm or less, the scattered light becomes very little, which is preferable. From the viewpoint of avoiding light scattering, a small dispersed particle size is preferred; if the dispersed particle size is 1 nm or more, industrial manufacturing is easier.

[0058] The composite tungsten oxide microparticles are represented by the general formula MxWOy (where M is one or more elements selected from Groups 1, 2, and 13 of the periodic table, 0.1 ≤ x ≤ 1.0, 2.0 ≤ y < 4.0), and have a hexagonal crystal structure. Preferably, the M element comprises at least one composite tungsten oxide microparticle selected from Cs, Rb, K, Tl, and Ba. The amount of M element added, x, is preferably 0.1 or more and 1.0 or less, more preferably around 0.33. This is because the theoretically calculated value for the hexagonal crystal structure is 0.33, and preferred optical properties can be obtained by adjusting the amount added before and after this value. Furthermore, regarding the range of y, 2.0 ≤ y < 4.0 is preferred.

[0059] Here, Cs can be cited as a typical example of this composite tungsten oxide material. 0.33 WO3, Rb 0.33 WO3, K 0.33 WO3, Ba 0.33 If x and y are within the range described in WO3, useful near-infrared shielding characteristics can be obtained.

[0060] 2) Method for manufacturing composite tungsten oxide microparticles used in the dispersion powder

[0061] a) Thermochemical manufacturing method

[0062] The composite tungsten oxide particles can be obtained by heat-treating tungsten compound starting materials in an inert or reducing gas atmosphere, followed by a mild oxidation treatment.

[0063] The starting material for tungsten compounds is preferably selected from any one or more of the following substances: tungsten trioxide powder, tungsten dioxide powder, or tungsten oxide hydrate, or tungsten hexachloride powder, or ammonium tungstate powder, or tungsten oxide hydrate powder obtained by dissolving tungsten hexachloride in alcohol and then drying it, or tungsten oxide hydrate powder obtained by dissolving tungsten hexachloride in alcohol, adding water to precipitate it and then drying it, or tungsten compound powder obtained by drying an aqueous solution of ammonium tungstate, or metallic tungsten powder.

[0064] Here, in the case of manufacturing composite tungsten oxide particles, since the starting material is a solution, from the viewpoint that the elements can be easily and uniformly mixed, it is further preferable to use an aqueous solution of ammonium tungstate or a solution of tungsten hexachloride. Using these materials, and subjecting them to heat treatment in an inert gas atmosphere or a reducing gas atmosphere, composite tungsten oxide particles of the stated particle size can be obtained.

[0065] Furthermore, when manufacturing composite tungsten oxide particles, element M is added to the tungsten compound starting material in the form of an elemental substance or a compound, serving as the starting material for the composite tungsten compound.

[0066] Here, in order to produce a starting material in which the components are uniformly mixed at the molecular level, it is preferable to mix the raw materials in the form of a solution. Therefore, it is preferable that the tungsten compound starting material containing element M is soluble in solvents such as water and organic solvents. Examples of such starting materials include tungstates, chloride salts, nitrates, sulfates, oxalates, oxides, carbonates, and hydroxides containing element M, but they are not limited to these, as long as they are in a solution state.

[0067] The preferred heat treatment conditions in an inert atmosphere are 650°C or higher. Starting materials heat-treated at 650°C or higher possess sufficient near-infrared absorption capacity, providing good efficiency in shielding heat-electrode particles. Inert gases such as Ar and N2 can be used as the inert gas.

[0068] On the other hand, as heat treatment conditions in a reducing atmosphere, it is preferable to first heat-treat the starting material in a reducing gas atmosphere at a temperature of 300°C or higher and 1000°C or lower, followed by heat treatment in an inert gas atmosphere at a temperature of 650°C or higher and 1200°C or lower. The reducing gas is not particularly limited, but H2 is preferred. Furthermore, when using H2 as the reducing gas, the composition of the reducing atmosphere is preferably, for example, a mixture of at least 0.1% H2 by volume in an inert gas such as Ar or N2, more preferably at least 0.2%. If the H2 content is 0.1% or higher by volume, reduction can be performed efficiently.

[0069] The composite tungsten oxide microparticles that provide near-infrared shielding in this embodiment are preferably surface-treated with at least one of silane compounds, titanium compounds, aluminum compounds, and zirconium oxide compounds. The surface of the microparticles is covered with a compound containing one or more of Si, Ti, Zr, and Al, thereby improving weather resistance.

[0070] b) Manufacturing methods using plasma

[0071] The method for manufacturing composite tungsten oxide microparticles using plasma method is described item by item.

[0072] (I) Raw material preparation

[0073] As starting materials, a mixture of tungsten compounds and M-element compounds, or a composite tungsten oxide precursor represented by the general formula MxWOy, can be used. Furthermore, the same materials described in the thermochemical manufacturing method are preferably used as the tungsten compound and the M-element compound.

[0074] As starting materials, in the case of preparing a mixture of tungsten compound and M element compound, the raw materials are prepared and mixed in such a way that the ratio of M element to tungsten in the mixture of tungsten compound and M element compound is equal to the ratio of x to y in the general formula of the target composite tungsten oxide.

[0075] Furthermore, when using a composite tungsten oxide precursor represented by the general formula MxWOy as the starting material, it is preferable to satisfy 0.001≤x≤1.0, 2.0 <y。

[0076] The composite tungsten oxide precursor represented by the general formula MxWOy can be synthesized, for example, by the aforementioned thermochemical manufacturing method.

[0077] (II) Plasma apparatus and reaction conditions

[0078] The plasma used in the manufacture of composite tungsten oxide particles can be, for example, any one of DC arc plasma, high-frequency plasma, microwave plasma, low-frequency AC plasma or plasmas superimposed thereon, or plasma obtained by an electrical method of applying a magnetic field to DC plasma, plasma obtained by a high-power laser, plasma obtained by a high-power electron beam or ion beam.

[0079] The following description uses a hybrid plasma reactor that combines a DC plasma device and a high-frequency plasma device as an example.

[0080] A mixture of inert gas and oxygen can be used as a carrier gas to transport the starting materials in the reaction process.

[0081] Plasma can be generated, for example, in an atmosphere of a single inert gas or a mixture of an inert gas and hydrogen. According to the plasma method, composite tungsten oxide particles with a single crystalline phase can be generated, for example.

[0082] There are no particular limitations on high-frequency power supplies, such as those with a frequency of around 4MHz and an output of 15kW or more but less than 50kW.

[0083] When using thermal plasma, thermal plasma with a high temperature section of 10,000 K or higher, more preferably 10,000 K or higher and 25,000 K or lower, is used, especially plasma in which the particle generation time can be controlled.

[0084] (III) Fabrication of composite tungsten oxide microparticles using plasma

[0085] The reaction system is evacuated using a vacuum evacuation device. The vacuum level is not particularly limited; for example, it can be evacuated to approximately 0.1 Pa. After evacuation, the reaction system is filled with argon gas. For example, it is preferable to use an argon gas flow system with a pressure of 1 atmosphere within the reaction system.

[0086] Then, plasma gas is supplied into the reaction vessel. There are no particular limitations on the plasma gas; for example, any gas selected from argon, a mixture of argon and helium (Ar-He mixture), a mixture of argon and nitrogen (Ar-N2 mixture), neon, helium, and xenon can be used.

[0087] There is no particular limitation on the supply flow rate of plasma gas. For example, it can be introduced at a flow rate of 3L / min or more and 30L / min or less, preferably 3L / min or more and 15L / min or less.

[0088] On the other hand, outside the plasma region, sheath gas is supplied from the sheath gas inlet for both high-frequency plasma generation and quartz tube protection. The type and supply rate of the sheath gas are not particularly limited; for example, argon gas is flowed at a rate of 20 L / min or higher but less than 50 L / min, and hydrogen gas is flowed at a rate of 1 L / min or higher but less than 5 L / min to generate high-frequency plasma.

[0089] After generating the mixed plasma, a carrier gas is introduced into the raw material powder through the carrier gas supply port. There are no particular limitations on the carrier gas; for example, a mixed gas containing argon at a flow rate of 1 L / min or more and 8 L / min or less, and oxygen at a flow rate of 0.001 L / min or more and 0.8 L / min or less can be used.

[0090] The starting material is supplied from the raw material powder carrier gas supply port at a rate preferably of 1 g / min or more and 50 g / min or less, more preferably 1 g / min or more and 20 g / min or less.

[0091] The starting material supplied to the plasma evaporates instantaneously within the plasma and undergoes a condensation process to generate composite tungsten oxide particles with an average primary particle size of less than 100 nm. It should be noted that the particle size of the composite tungsten oxide particles can be easily controlled by factors such as plasma output, plasma flow rate, and the amount of raw material powder supplied.

[0092] In order to obtain the desired near-infrared shielding resin molded body using composite tungsten oxide microparticles manufactured by the described thermochemical manufacturing method or by plasma manufacturing method, the powder color of the composite tungsten oxide microparticles preferably satisfies the following conditions: in the powder color of the L*a*b* color system (JIS Z 8729) recommended by the International Commission on Illumination (CIE), L* is 25~80, a* is -10~10, and b* is -15~15.

[0093] By using the composite tungsten oxide microparticles, the desired optical properties as a near-infrared shielding resin sheet can be obtained.

[0094] 3) Dispersants used in dispersing powders

[0095] Dispersants are used to hydrophobize the surface of composite tungsten oxide particles. The dispersant can be selected based on the combination of the composite tungsten oxide particles, the dispersion medium, and the coating resin raw material, i.e., the dispersion system. Acrylic dispersants are preferred, and dispersants with acidic functional groups are even more preferred. Examples include hydroxyl, carboxyl, phosphate, and sulfonyl groups. Carboxyl groups are the most preferred.

[0096] The weight-average molecular weight of the dispersant is 15,000 or more and 80,000 or less, more preferably 20,000 or more and 40,000 or less. When the weight-average molecular weight is higher than 15,000, the dispersion stability is good, and the agglomeration of the composite tungsten oxide particles is suppressed. If the weight-average molecular weight is lower than 80,000, the composite tungsten oxide particles are easy to pulverize.

[0097] Furthermore, the acid value of the dispersant is preferably 3.0 mg KOH / g or higher and 20.0 mg KOH / g or lower, more preferably 5.0 mg KOH / g or higher and 15.0 mg KOH / g or lower. If the acid value is higher than 3.0 mg KOH / g, the dispersibility of the composite tungsten oxide particles is good. If the acid value is lower than 20.0 mg KOH / g, the dispersant has good compatibility with the organic solvent, and the dispersibility of the composite tungsten oxide particles is good.

[0098] Furthermore, the glass transition temperature (the temperature at which the dispersant softens when heated above a certain temperature) can be above 90°C and below 150°C. If the glass transition temperature is above 90°C, the dispersant powder can be melt-mixed into the resin within a temperature range of 250°C to 300°C.

[0099] Based on the amount of acrylic dispersant with acidic functional groups added relative to the composite tungsten oxide particles, the weight ratio of dispersant to composite tungsten oxide particles is set to a range of 0.3 ≤ (weight of dispersant / weight of composite tungsten oxide) < 3.0, more preferably a range of 0.3 ≤ (weight of dispersant / weight of composite tungsten oxide) ≤ 1.0, 0.3 ≤ (weight of dispersant / weight of composite tungsten oxide) ≤ 0.8, and even more preferably a range of 0.3 ≤ (weight of dispersant / weight of composite tungsten oxide) ≤ 0.5. This allows for the acquisition of both a heat-shielding resin molded body with high weather resistance and a heat-shielding laminate with high weather resistance. As a result, it is possible to achieve both the viewpoint of obtaining a dispersant powder with a large concentration adjustment amount (balance) by significantly increasing the content of heat-shielding particles in the dispersant powder, and the viewpoint of obtaining a heat-shielding resin molded body with high weather resistance and a heat-shielding laminate with high weather resistance.

[0100] This is believed to be because, in the composite tungsten oxide microparticles with large crystallite size of the present invention, even through mixing and pulverizing during the manufacturing of the dispersion described below, it is less likely to cause defects in the constituent elements, thereby reducing damage to the crystal structure and ensuring high weather resistance. On the other hand, the inventors have found that if the weight ratio of the dispersant to the composite tungsten oxide microparticles exceeds 3.0, the weather resistance decreases. This decrease in weather resistance is believed to be due to a chemical reaction occurring between the dispersant and the composite tungsten oxide microparticles.

[0101] 4) Method for manufacturing the composite tungsten oxide microparticle dispersion used in the dispersing powder

[0102] In the manufacturing process of the composite tungsten oxide microparticle dispersion used in the manufacture of the dispersion powder, the dispersion can be manufactured by mixing composite tungsten oxide microparticles, dispersant and dispersion medium. From the viewpoint of reducing the particle size of the composite tungsten oxide microparticles and making them uniformly dispersed in the dispersion, it is preferable to perform the pulverization process of the composite tungsten oxide microparticles at the same time as mixing.

[0103] The dispersion medium can be any organic compound that can disperse the composite tungsten oxide particles and the dispersant to form a dispersion. For example, one or more organic solvents selected from aromatic hydrocarbons such as toluene and xylene are preferred.

[0104] The mixing method used for mixing and pulverizing composite tungsten oxide particles, dispersants, and dispersion media is not particularly limited; for example, one or more selected from bead mills, ball mills, sand mills, paint mixers, and ultrasonic homogenizers can be used. Particularly preferred mixing methods are media-stirred mills such as bead mills, ball mills, sand mills, and paint mixers that use media such as beads, balls, or Ottawa sand. This is because, by using a media-stirred mill, the composite tungsten oxide particles can achieve the desired dispersed particle size in a very short time, which is preferable from the viewpoint of productivity and suppression of impurity contamination.

[0105] Here, from the viewpoint of enabling the composite tungsten oxide particles to exhibit both transparency and high weather resistance, it is preferable to pulverize the composite tungsten oxide to a crystallite size of 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. When the crystallite size of the composite tungsten oxide particles is within this range, combined with the weight ratio of the dispersant to the composite tungsten oxide particles being within the given range, the composite tungsten oxide particles achieve a balance between transparency and high weather resistance.

[0106] To achieve the aforementioned objective, the concentration of the composite tungsten oxide particles in the organic solvent serving as the dispersion medium is preferably 5 to 50% by mass. If the concentration of the composite tungsten oxide particles is 5% by mass or higher, the amount of organic solvent that needs to be removed in subsequent processes can be suppressed, thereby reducing manufacturing costs. Furthermore, if the concentration of the composite tungsten oxide particles is 50% by mass or lower, particle aggregation will not occur, and the viscosity of the liquid will not increase, thus simplifying processing.

[0107] 5) Method for manufacturing dispersing powder

[0108] The drying process used to obtain the dispersed powder of the present invention is a process performed to remove organic solvents from the dispersion. This process is preferably carried out by vacuum drying of the obtained dispersion. Specifically, vacuum drying is performed while stirring the dispersion using a vacuum drying apparatus to separate the dispersed powder from the organic solvent components. Examples of apparatus used in vacuum drying include vacuum-stirred dryers; any apparatus with the aforementioned function is acceptable and is not particularly limited. Furthermore, the pressure of the vacuum drying process is appropriately selected.

[0109] By using this reduced-pressure drying method, the removal efficiency of organic solvents is improved, and the dispersed powder is not exposed to high temperatures for extended periods, thus preventing agglomeration of the dispersed particles, making it a preferred method. Furthermore, productivity is increased, and the evaporated organic solvents are easily recovered, making it also preferred from an environmental perspective.

[0110] 6) Thermoplastic resin used in hot wire shielding resin molded bodies

[0111] As for the thermoplastic resin used in this invention, there are no particular limitations as long as it is a transparent thermoplastic resin with high light transmittance in the visible light region. For example, thermoplastic resins with visible light transmittance of 50% or more as described in JIS R 3106 when forming a 3mm thick sheet can be cited, and thermoplastic resins with haze of 30% or less as described in JIS K 7105 can be cited.

[0112] Specifically, examples include acrylic resins, polycarbonate resins, polyetherimide resins, polyester resins, polystyrene resins, polyethersulfone resins, fluorinated resins, and polyolefin resins. When the purpose is to apply heat-shielded transparent resin substrates to window materials in various buildings or vehicles, acrylic resins, polycarbonate resins, polyetherimide resins, and fluorinated resins are preferred, considering factors such as transparency, impact resistance, and weather resistance.

[0113] As a polycarbonate resin, aromatic polycarbonate is preferred. Examples of aromatic polycarbonate include polymers obtained by known methods such as interfacial polymerization, melt polymerization, or solid-state polymerization of one or more diphenolic compounds, such as 2,2-bis(4-hydroxyphenyl)propane and 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, and carbonate precursors, such as phosgene or diphenyl carbonate.

[0114] Examples of acrylic resins include polymers or copolymers that use methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate as main raw materials, and, as needed, use alkyl acrylates, vinyl acetate, styrene, acrylonitrile, methacrylonitrile, etc., with alkyl groups having 1 to 8 carbon atoms as copolymerizing components. Furthermore, acrylic resins that have undergone further multi-stage polymerization can also be used.

[0115] Examples of fluorinated resins include polyvinyl fluoride, polydifluoroethylene, polytetrafluoroethylene, ethylene-difluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer, and tetrafluoroethylene-perfluoroalkoxyethylene copolymer.

[0116] 7) Methods for dispersing powder into thermoplastic resin

[0117] The dispersion method for dispersing powder into thermoplastic resin can be any method that allows the composite tungsten oxide particles contained in the dispersion powder to be uniformly dispersed in the resin.

[0118] As an example, firstly, a dispersion in any solvent is prepared using methods such as bead mills, ball mills, sand mills, and ultrasonic dispersion. Next, this dispersion, dispersant, thermoplastic resin powder or particles, and other additives as needed, are uniformly melt-mixed using mixers such as belt mixers, drum mixers, NAUTA mixers, Henschel mixers, super mixers, planetary mixers, as well as BANBURY mixers, kneaders, rollers, kneaders, single-screw extruders, and twin-screw extruders, while removing the solvent from the dispersion. This process prepares a mixture in which composite tungsten oxide particles are uniformly dispersed in the thermoplastic resin. The mixing temperature is maintained at a temperature that prevents the thermoplastic resin from decomposing.

[0119] Alternatively, as another method, the dispersion powder can be uniformly melt-mixed with the powder or particles of the thermoplastic resin, as well as other additives as needed, to prepare a mixture in which composite tungsten oxide particles are uniformly dispersed in the thermoplastic resin.

[0120] Alternatively, a method can be used to uniformly melt-mix the dispersing powder with the powder or particles of the thermoplastic resin, and other additives as needed.

[0121] The dispersion method is not limited to any method that uniformly disperses the composite tungsten oxide particles in the thermoplastic resin.

[0122] 8) Manufacturing method of hot wire shielding resin molded body and hot wire shielding laminate

[0123] Next, the hot wire shielding resin molded body of this embodiment is obtained by diluting and mixing the dispersed powder with a thermoplastic resin molding material and molding it into a given shape.

[0124] In this embodiment, because a dispersing powder is used, it is easy to mix into the thermoplastic resin, thus allowing the mixing process for molding the heat-shielding resin molded body to be completed in a short time. As a result, the thermal degradation of the dispersing powder itself is very small, and the composite tungsten oxide particles are fully dispersed in the near-heat-shielding resin molded body, thus ensuring good visible light transmittance and exhibiting excellent heat-shielding function.

[0125] The shape of the heat-shielding resin molded body can be molded into any shape as needed, including planar and curved shapes. Furthermore, the thickness of the heat-shielding resin molded body can be adjusted to any thickness as required. Additionally, the planar resin sheet can be further processed into any shape, such as a spherical shape.

[0126] Examples of molding methods for the heat-shielding resin molded body include injection molding, extrusion molding, compression molding, and rotational molding. Injection molding and extrusion molding are particularly preferred. Extrusion molding can be used to obtain sheet-like or film-like molded articles by drawing molten thermoplastic resin extruded using an extruder such as a T-die while cooling it with cooling rollers.

[0127] The heat-shielding resin molded body can be used alone in structural materials such as window glass and archways, or it can be laminated to other molded bodies such as inorganic glass, resin glass, and resin film by any method to form an integrated heat-shielding laminate for use as a structural material. For example, by using a hot lamination method to integrate a pre-molded film-like heat-shielding resin molded body with inorganic glass, a heat-shielding laminate with heat-shielding and anti-scattering functions can be obtained.

[0128] In addition, heat-shielding resin molded bodies can be laminated and integrated with other molded bodies during the molding process using methods such as hot lamination, co-extrusion, compression molding, and injection molding, thereby obtaining a heat-shielding laminate. This heat-shielding laminate, by effectively leveraging the advantages of each molded body while compensating for their respective disadvantages, can be used as a more useful structural material.

[0129] As detailed above, by using a dispersion powder composed of composite tungsten oxide particles and a dispersant as the thermal shielding component, it is possible to provide thermal shielding resin molded bodies and thermal shielding laminates with excellent weather resistance and high transmittance in the visible light region, thus providing excellent thermal shielding function, without the need for costly physical film-forming methods or complex processes.

[0130] Example

[0131] The present invention will be specifically described using examples. However, the present invention is not limited to the following examples.

[0132] The visible light transmittance, as well as the transmittance at wavelengths of 820 nm, 1000 nm, and 1500 nm, of the prepared heat-shielded resin molded body before and after the weathering resistance test were measured using a Hitachi UH-4150 spectrophotometer. The Δ transmittance at each wavelength (= transmittance after weathering resistance test - transmittance before weathering resistance test) is an indicator of weathering resistance performance.

[0133] [Example 1]

[0134] Dissolve 17.7 g of Cs₂CO₃ in 39.9 g of water, then add it to 82.3 g of H₂WO₄ and dry using a vacuum dryer while stirring. The resulting dried powder is then calcined at 550 °C for 1 hour in a 5% H₂ atmosphere with N₂ as the carrier gas, followed by calcination at 800 °C for 1 hour in an N₂ atmosphere to obtain particle a. Chemical analysis shows that particle a has the composition of Cs₂CO₃. 0.33 WO 2.45 Based on the results of powder X-ray diffraction, it is hexagonal Cs. 0.3 WO3.

[0135] Next, 15% by weight of the microparticle a, 6% by weight of an acrylic dispersant with acidic functional groups, and 79% by weight of toluene were weighed and pulverized and dispersed for 6 hours using a paint stirrer with 0.3 mm φ ZrO2 beads added, thereby preparing a composite tungsten oxide microparticle dispersion (liquid A). Here, the crystallite size of the composite tungsten oxide microparticles in liquid A was measured, and the result was 31.8 nm. Then, toluene was removed from liquid A using a large vacuum pulverizer to obtain composite tungsten oxide microparticle dispersion powder (dispersion powder A).

[0136] The obtained dispersion powder A was added to polycarbonate resin powder, which is a thermoplastic resin, at a concentration of 0.08% by weight of composite tungsten oxide particles. After being uniformly mixed with a mixer, the mixture was melt-kneaded using a twin-screw extruder and extruded into a thickness of 1 mm using a T-die. Then, it was hot-pressed to obtain a heat-shielded resin molded body with a thickness of 0.8 mm, in which composite tungsten oxide particles are uniformly dispersed throughout the resin.

[0137] The heat-shielded resin molded body was subjected to xenon arc weathering test conditions (temperature 60℃, relative humidity 50%RH, irradiance 150W / m²). 2An exposure test was conducted after 200 hours of exposure. The optical properties after the test were measured, and the results are shown in Table 1. The Δ transmittance at a wavelength of 820 nm was 2.6% when the visible light transmittance was 78.8%, the Δ transmittance at a wavelength of 1000 nm was 1.5%, and the Δ transmittance at a wavelength of 1500 nm was 1.3%.

[0138] [Example 2]

[0139] The acrylic dispersant having acidic functional groups as functional groups was 7.5% by weight and toluene was 77.5% by weight. Otherwise, the composite tungsten oxide microparticle dispersion powder (dispersion powder B) of Example 2 was obtained in the same manner as in Example 1.

[0140] Using dispersant B, the heat-shielding resin molded body of Example 2 was prepared in the same manner as in Example 1, and an exposure test was performed under the same conditions as in Example 1 to evaluate its optical properties.

[0141] The microcrystal size of the composite tungsten oxide microparticles in the composite tungsten oxide microparticle dispersion in Example 2 is 32.6 nm.

[0142] The optical properties of the hot wire shielding resin molded body of Example 2 after exposure test were measured. The results are shown in Table 1. The Δ transmittance at a wavelength of 820 nm was 2.5% when the visible light transmittance was 78.1%, the Δ transmittance at a wavelength of 1000 nm was 1.6%, and the Δ transmittance at a wavelength of 1500 nm was 1.3%.

[0143] [Example 3]

[0144] The acrylic dispersant having acidic functional groups as functional groups was 9.0% by weight and toluene was 76.0% by weight. Otherwise, the composite tungsten oxide microparticle dispersion powder (dispersion powder C) of Example 3 was obtained in the same manner as in Example 1.

[0145] Using dispersant powder C, the heat-shielding resin molded body of Example 3 was prepared in the same manner as in Example 1, and an exposure test was performed under the same conditions as in Example 1 to evaluate its optical properties.

[0146] The microcrystal size of the composite tungsten oxide microparticles in the composite tungsten oxide microparticle dispersion in Example 3 is 32.3 nm.

[0147] The optical properties of the hot wire shielding resin molded body of Example 3 after exposure test were measured. The results are shown in Table 1. The Δ transmittance at a wavelength of 820 nm was 2.6% when the visible light transmittance was 78.7%, the Δ transmittance at a wavelength of 1000 nm was 1.6%, and the Δ transmittance at a wavelength of 1500 nm was 1.3%.

[0148] [Example 4]

[0149] The acrylic dispersant having acidic functional groups as functional groups was 12.0% by weight and toluene was 73.0% by weight. Otherwise, the composite tungsten oxide microparticle dispersion powder (dispersion powder D) of Example 4 was obtained in the same manner as in Example 1.

[0150] Using dispersant powder D, the heat-shielding resin molded body of Example 4 was prepared in the same manner as in Example 1, and an exposure test was performed under the same conditions as in Example 1 to evaluate its optical properties.

[0151] The microcrystal size of the composite tungsten oxide microparticles in the composite tungsten oxide microparticle dispersion in Example 4 is 32.7 nm.

[0152] The optical properties of the hot wire shielding resin molded body of Example 4 were measured after exposure test. The results are shown in Table 1. The Δ transmittance at a wavelength of 820 nm was 2.8% when the visible light transmittance was 78.9%, the Δ transmittance at a wavelength of 1000 nm was 1.7%, and the Δ transmittance at a wavelength of 1500 nm was 1.5%.

[0153] [Example 5]

[0154] Dissolve 8.8 g of Cs₂CO₃ in 16.5 g of water, then add it to 50 g of H₂WO₄ and dry using a vacuum dryer while stirring. The resulting dried powder is calcined at 570 °C for 1 hour in a 5% H₂ atmosphere with N₂ as the carrier, then calcined at 800 °C for 1 hour in a 1% air atmosphere with N₂ as the carrier, and finally calcined at 820 °C for 0.5 hours in an N₂ atmosphere to obtain particle b. Chemical analysis shows that particle b has the composition Cs₂CO₃. 0.27 WO 2.86 Based on the results of powder X-ray diffraction, it is hexagonal Cs. 0.3 WO3.

[0155] Using microparticle b, the composite tungsten oxide microparticle dispersion powder (dispersion powder E) of Example 5 was obtained in the same manner as in Example 1. The heat-shielding resin molded body of Example 5 was further prepared, and an exposure test was carried out under the same conditions as in Example 1 to evaluate its optical properties.

[0156] The microcrystal size of the composite tungsten oxide microparticles in the composite tungsten oxide microparticle dispersion in Example 5 is 31.5 nm.

[0157] The optical properties of the hot wire shielding resin molded body of Example 5 after exposure test were measured. The results are shown in Table 1. The Δ transmittance at a wavelength of 820 nm was 2.9% when the visible light transmittance was 80.0%, the Δ transmittance at a wavelength of 1000 nm was 1.8%, and the Δ transmittance at a wavelength of 1500 nm was 1.8%.

[0158] [Example 6]

[0159] Dissolve 17.7g of Cs2CO3 in 39.9g of water, add it to 82.3g of H2WO4, and dry it with a vacuum dryer while stirring to obtain dried powder a.

[0160] A hybrid plasma reactor combining DC and high-frequency plasma was used. The reaction system was evacuated to approximately 0.1 Pa (approximately 0.001 torr) using a vacuum exhaust device, and then completely purged with argon gas to create a flow system at 1 atmosphere. Argon gas was then introduced at a rate of 8 L / min through the plasma generation gas supply port to generate DC plasma. The DC power input at this time was 6 kW. Additionally, argon gas at a rate of 40 L / min and hydrogen gas at a rate of 3 L / min were spirally introduced from the sheath gas supply port along the inner wall of the water-cooled quartz tube as both high-frequency plasma generation and quartz tube protection gas to generate high-frequency plasma. The high-frequency power input at this time was 45 kW. After generating the hybrid plasma, a mixture of 3 L / min argon gas and 0.15 L / min oxygen gas was used as the carrier gas, and the obtained dried powder a was supplied to the plasma at a rate of 2 g / min via a raw material powder supply device. As a result, the raw material evaporated instantaneously, condensed and pulverized in the plasma tail flame, yielding microparticle c. Chemical analysis showed that microparticle c had a composition of Cs. 0.31 WO 3.21 The powder X-ray diffraction results show that it is a hexagonal Cs crystal. 0.3 WO3.

[0161] Using microparticle c, the composite tungsten oxide microparticle dispersion powder (dispersion powder F) of Example 6 was obtained in the same manner as in Example 1. The heat-shielding resin molded body of Example 6 was further prepared and an exposure test was performed under the same conditions as in Example 1 to evaluate its optical properties.

[0162] The microcrystal size of the composite tungsten oxide microparticles in the composite tungsten oxide microparticle dispersion in Example 6 is 24.6 nm.

[0163] The optical properties of the hot wire shielding resin molded body of Example 6 after exposure test were measured. The results are shown in Table 1. The Δ transmittance at a wavelength of 820 nm was 3.4% when the visible light transmittance was 79.2%, the Δ transmittance at a wavelength of 1000 nm was 2.0%, and the Δ transmittance at a wavelength of 1500 nm was 1.9%.

[0164] [Example 7]

[0165] In preparing the raw materials, K₂CO₃ and H₂WO₄ were set to a K / W molar ratio of 0.33. Otherwise, the composite tungsten oxide particles d of Example 7 were obtained in the same manner as in Example 1. According to chemical analysis, the composition of particles d was K₂CO₃ / H₂WO₄. 0.33 WO 2.45 The powder X-ray diffraction results show that it is a hexagonal K-type crystal. 0.3 WO3.

[0166] Using microparticles d, the composite tungsten oxide microparticle dispersion powder (dispersion powder G) of Example 7 was obtained in the same manner as in Example 1.

[0167] Using dispersant powder G, except that the hot wire shielding resin molded body of Example 7 was prepared in the same manner as in Example 1, and an exposure test was performed under the same conditions as in Example 1 to evaluate its optical properties.

[0168] The microcrystal size of the composite tungsten oxide microparticles in the composite tungsten oxide microparticle dispersion in Example 7 is 31.6 nm.

[0169] The optical properties of the hot wire shielding resin molded body of Example 7 after exposure test were measured. The results are shown in Table 1. The Δ transmittance at a wavelength of 820 nm was 3.4% when the visible light transmittance was 78.0%, the Δ transmittance at a wavelength of 1000 nm was 2.2%, and the Δ transmittance at a wavelength of 1500 nm was 2.0%.

[0170] [Example 8]

[0171] In preparing the raw materials, Rb₂CO₃ and H₂WO₄ were set to an Rb / W molar ratio of 0.33. Otherwise, the composite tungsten oxide particles e of Example 8 were obtained in the same manner as in Example 1. According to chemical analysis, the composition of particle e was Rb 0.33 WO 2.45 The powder X-ray diffraction results show that the Rb crystal is hexagonal. 0.33 WO3.

[0172] Using microparticle e, the composite tungsten oxide microparticle dispersion (dispersion powder H) of Example 8 was obtained in the same manner as in Example 1.

[0173] Using dispersant powder H, except that the hot wire shielding resin molded body of Example 8 was prepared in the same manner as in Example 1, and the optical properties were evaluated by exposure testing under the same conditions as in Example 1.

[0174] The microcrystal size of the composite tungsten oxide microparticles in the composite tungsten oxide microparticle dispersion in Example 8 is 32.2 nm.

[0175] The optical properties of the hot wire shielding resin molded body of Example 8 after exposure test were measured. The results are shown in Table 1. The Δ transmittance at a wavelength of 820 nm was 2.9% when the visible light transmittance was 79.9%, the Δ transmittance at a wavelength of 1000 nm was 2.1%, and the Δ transmittance at a wavelength of 1500 nm was 2.0%.

[0176] [Example 9]

[0177] In preparing the raw materials, Tl(NO3)3·3H2O and H2WO4 were set to a Tl / W molar ratio of 0.33. Otherwise, the composite tungsten oxide particles g of Example 9 were obtained in the same manner as in Example 1. According to chemical analysis, the composition of particle g was Tl... 0.33 WO 2.45 The powder X-ray diffraction results show that it is a hexagonal Tl crystal. 0.3 WO3.

[0178] Using microparticles g, the composite tungsten oxide microparticle dispersion powder (dispersion powder I) of Example 9 was obtained in the same manner as in Example 1.

[0179] Using dispersant powder I, except that the hot wire shielding resin molded body of Example 9 was prepared in the same manner as in Example 1, and the optical properties were evaluated by exposure testing under the same conditions as in Example 1.

[0180] The microcrystal size of the composite tungsten oxide microparticles in the composite tungsten oxide microparticle dispersion in Example 9 is 32.6 nm.

[0181] The optical properties of the heat-shielded resin molded body of Example 9 after exposure test were measured. The results are shown in Table 1. The Δ transmittance at wavelength 820nm was 3.0% when the visible light transmittance was 79.4%, the Δ transmittance at wavelength 1000nm was 2.2%, and the Δ transmittance at wavelength 1500nm was 2.0%.

[0182] [Example 10]

[0183] In preparing the raw materials, the BaCO3 and H2WO4 were set to a Ba / W molar ratio of 0.33. Otherwise, the composite tungsten oxide particles h of Example 10 were obtained in the same manner as in Example 1. According to chemical analysis, the composition of particle h was Ba... 0.33 WO 2.45 The powder X-ray diffraction results show that it is hexagonal Ba. 0.3 WO3.

[0184] Using particle h, the composite tungsten oxide particle dispersion powder (dispersion powder J) of Example 10 was obtained in the same manner as in Example 1.

[0185] Using dispersant powder J, the heat-shielding resin molded body of Example 10 was prepared in the same manner as in Example 1, and an exposure test was performed under the same conditions as in Example 1 to evaluate its optical properties.

[0186] The microcrystal size of the composite tungsten oxide microparticles in the composite tungsten oxide microparticle dispersion of Example 10 is 32.5 nm.

[0187] The optical properties of the hot wire shielding resin molded body of Example 10 after exposure test were measured. The results are shown in Table 1. The Δ transmittance at a wavelength of 820 nm was 3.7% when the visible light transmittance was 78.0%, the Δ transmittance at a wavelength of 1000 nm was 2.6%, and the Δ transmittance at a wavelength of 1500 nm was 2.0%.

[0188] [Example 11]

[0189] Using an acrylic resin as the thermoplastic resin, the heat-shielding resin molded article of Example 11 was obtained in the same manner as in Example 1. Subsequently, it was exposed under the same conditions as in Example 1, and its optical properties were evaluated.

[0190] As shown in Table 1, when the visible light transmittance is 80.8%, the Δ transmittance at wavelength 820nm is 3.4%, at wavelength 1000nm is 2.5%, and at wavelength 1500nm is 2.0%.

[0191] [Example 12]

[0192] The acrylic dispersant having acidic functional groups as functional groups was 15.0% by weight and toluene was 70.0% by weight. Otherwise, the composite tungsten oxide microparticle dispersion powder (dispersion powder K) of Example 12 was obtained in the same manner as in Example 1.

[0193] Using dispersant powder K, the heat-shielding resin molded body of Example 12 was prepared in the same manner as in Example 1, and an exposure test was performed under the same conditions as in Example 1 to evaluate its optical properties.

[0194] The microcrystal size of the composite tungsten oxide microparticles in the composite tungsten oxide microparticle dispersion in Example 12 is 32.2 nm.

[0195] The optical properties of the hot wire shielding resin molded body of Example 12 were measured after exposure test. The results are shown in Table 1. The Δ transmittance at a wavelength of 820 nm was 3.7% when the visible light transmittance was 79.1%, the Δ transmittance at a wavelength of 1000 nm was 2.2%, and the Δ transmittance at a wavelength of 1500 nm was 1.9%.

[0196] [Example 13]

[0197] The acrylic dispersant having acidic functional groups as functional groups was 4.5 wt% and toluene was 80.5 wt%. Otherwise, the composite tungsten oxide microparticle dispersion powder (dispersion powder L) of Example 13 was obtained in the same manner as in Example 1.

[0198] Using dispersant L, the hot wire shielding resin molded body of Example 13 was prepared in the same manner as in Example 1, and exposure tests were performed under the same conditions as in Example 1 to evaluate its optical properties.

[0199] The microcrystal size of the composite tungsten oxide microparticles in the composite tungsten oxide microparticle dispersion in Example 13 is 32.2 nm.

[0200] The optical properties of the hot wire shielding resin molded body of Example 13 were measured after exposure test. The results are shown in Table 1. The Δ transmittance at a wavelength of 820 nm was 2.3% when the visible light transmittance was 78.0%, the Δ transmittance at a wavelength of 1000 nm was 1.4%, and the Δ transmittance at a wavelength of 1500 nm was 1.3%.

[0201] [Example 14]

[0202] When pulverizing and dispersing particles a, the pulverization and dispersion process was carried out using a paint mixer for 20 hours. Otherwise, the heat-shielding resin molded body of Example 14 was obtained in the same manner as in Example 1. Subsequently, an exposure test was conducted under the same conditions as in Example 1 to evaluate its optical properties.

[0203] The microcrystal size of the composite tungsten oxide microparticles in the composite tungsten oxide microparticle dispersion in Example 14 is 15.0 nm.

[0204] The optical properties of the hot wire shielding resin molded body of Example 14 were measured after exposure test. The results are shown in Table 1. The Δ transmittance at a wavelength of 820 nm was 3.8% when the visible light transmittance was 80.3%, the Δ transmittance at a wavelength of 1000 nm was 2.7%, and the Δ transmittance at a wavelength of 1500 nm was 2.1%.

[0205] [Example 15]

[0206] When pulverizing and dispersing particles a, the pulverization and dispersion process was carried out using a paint mixer for 1 hour. Otherwise, the heat-shielding resin molded body of Example 15 was obtained in the same manner as in Example 1. Subsequently, an exposure test was conducted under the same conditions as in Example 1 to evaluate its optical properties.

[0207] The microcrystal size of the composite tungsten oxide microparticles in the composite tungsten oxide microparticle dispersion in Example 15 is 80 nm.

[0208] The optical properties of the hot wire shielding resin molded body of Example 15 were measured after exposure test. The results are shown in Table 1. The Δ transmittance at a wavelength of 820 nm was 2.0% when the visible light transmittance was 79.8%, the Δ transmittance at a wavelength of 1000 nm was 1.0%, and the Δ transmittance at a wavelength of 1500 nm was 1.0%.

[0209] [Comparative Example 1]

[0210] The acrylic dispersant having acidic functional groups as functional groups was 45.0% by weight and toluene was 35.0% by weight. Otherwise, the composite tungsten oxide microparticle dispersion powder (dispersion powder M) of Comparative Example 1 was obtained in the same manner as in Example 1.

[0211] Using dispersant powder M, the hot wire shielding resin molded body of Comparative Example 1 was prepared in the same manner as in Example 1, and an exposure test was performed under the same conditions as in Example 1 to evaluate its optical properties.

[0212] The crystallite size of the composite tungsten oxide particles in the composite tungsten oxide particle dispersion of Comparative Example 1 is 32.9 nm.

[0213] The optical properties of the hot wire shielding resin molded body of Comparative Example 1 after exposure test were measured. The results are shown in Table 1. The Δ transmittance at a wavelength of 820 nm was 5.6% when the visible light transmittance was 79.2%, the Δ transmittance at a wavelength of 1000 nm was 3.1%, and the Δ transmittance at a wavelength of 1500 nm was 2.6%.

[0214] [Comparative Example 2]

[0215] The composite tungsten oxide microparticle dispersion of Comparative Example 1 was prepared in the same manner as in Example 1, with an acrylic dispersant having an acidic functional group of 3.0 wt% and toluene of 82.0 wt%.

[0216] However, the microcrystal size of the composite tungsten oxide particles in the composite tungsten oxide particle dispersion of Comparative Example 2 was 96.3 nm. The particle size was not pulverized to the desired size during the dispersion preparation stage, so the experiment was terminated.

[0217] [Comparative Example 3]

[0218] When pulverizing and dispersing particles a, the pulverizing and dispersing process was carried out for 25 hours using a paint mixer. Otherwise, the heat-shielding resin molded body of Example 15 was prepared in the same manner as in Example 1. However, due to the gelation of the dispersion, the preparation of the heat-shielding resin molded body and the evaluation of its optical properties were not achieved, and the experiment was terminated.

[0219] [evaluate]

[0220] Based on the results shown in Table 1, it can be confirmed that the visible light transmittance of the heat-shielded resin molded bodies after the weathering test of Examples 1 to 15 is above 78.0%, and the Δ transmittance at wavelength 820nm is below 3.8%, the Δ transmittance at wavelength 1000nm is below 2.7%, and the Δ transmittance at wavelength 1500nm is below 2.1%.

[0221] On the other hand, it can be confirmed that the visible light transmittance of the heat-shielding resin molded body of Comparative Example 1 is over 78.0%, the Δ transmittance at 820 nm exceeds 3.8%, the Δ transmittance at 1000 nm exceeds 2.7%, and the Δ transmittance at 1500 nm exceeds 2.1%, with high Δ transmittance in the near-infrared region. Furthermore, in Comparative Example 2, the pulverization did not reach the desired particle size in the dispersion preparation stage. In addition, in Comparative Example 3, gelation occurred during the dispersion preparation stage, failing to achieve the desired results in the preparation of the heat-shielding resin molded body and the evaluation of its optical properties.

[0222] [Table 1]

[0223]

Claims

1. A dispersing powder comprising composite tungsten oxide microparticles, said composite tungsten oxide microparticles being represented by the general formula MxWOy and having a hexagonal crystal structure, with a crystallite size of 15 nm or more and 80 nm or less, and surface-modified with an acrylic dispersant. in, Element M is one or more elements selected from Groups 1, 2, and 13 of the periodic table, where 0.1 ≤ x ≤ 1.0 and 2.0 ≤ y < 4.

0. The weight ratio of the dispersant to the composite tungsten oxide particles is in the range of 0.3 ≤ (weight of dispersant / weight of composite tungsten oxide particles) < 3.

0.

2. The dispersible powder according to claim 1, wherein, The acrylic dispersant has acidic functional groups as its functional groups.

3. The dispersible powder according to claim 1 or 2, wherein, The M element contained in the composite tungsten oxide particles is selected from at least one of Cs, Rb, K, Tl, and Ba.

4. A method for manufacturing a dispersible powder, wherein, By adding composite tungsten oxide microparticles with a hexagonal crystal structure (represented by the general formula MxWOy) and an acrylic dispersant to an organic solvent, followed by pulverization and dispersion treatment, a dispersion of the composite tungsten oxide microparticles with a crystallite size of 15 nm or more and 80 nm or less is produced. The organic solvent is removed from the dispersion to produce a dispersion powder in which the weight ratio of the dispersant to the composite tungsten oxide particles is in the range of 0.3 ≤ (weight of dispersant / weight of composite tungsten oxide particles) < 3.

0. Among them, element M is one or more elements selected from groups 1, 2, and 13 of the periodic table, with 0.1≤x≤1.0 and 2.0≤y<4.

0.

5. A heat-shielding resin molded body, obtained by diluting and mixing the dispersion powder of claim 1 or 2 with a thermoplastic resin molding material and molding it into a given shape.

6. The heat-wire shielding resin molded body according to claim 5, wherein, The thermoplastic resin molding material is a polycarbonate resin or an acrylic resin.

7. A heat wire shielding laminate, in ， The hot wire shielding resin molded body of claim 5 is laminated with other molded bodies.

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