Boride particles, liquid dispersed with boride particles, transparent base that blocks infrared light, optical member that blocks infrared light, body dispersed with infrared-blocking particles, transparent laminated base that blocks infrared light, powder dispersed with infrared-blocking particles, and masterbatch.

Abstract

Page 1 of 1 Summary of the invention. A boride particle represented by the general formula XBm(where X is at least one type of boride). The selected metallic components are Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb. Lu, Sr, Ca, and m (numbers representing the amount of boron in the general formula) are prepared in which the quantities... The amount of carbon incorporated into the boride particles is 0.2% by mass or less, as measured by the method. Absorbs infrared radiation from combustion.

Description

Boride particles, boride particle dispersion, infrared-shielding transparent substrate, infrared-shielding optical member, infrared-shielding particle dispersion, infrared-shielding laminated transparent substrate, infrared-shielding particle dispersion powder, and masterbatch The present invention relates to boride particles, a boride particle dispersion, an infrared-shielding transparent substrate, an infrared-shielding optical member, an infrared-shielding particle dispersion, an infrared-shielding laminated transparent substrate, an infrared-shielding particle dispersion powder, and a masterbatch. Conventionally, boride particles of rare earth elements such as La have been produced by being synthesized by a solid-phase reaction method and then pulverized by a dry pulverization method. In particular, a method of colliding particles with each other by a high-speed air flow such as a jet mill is generally used. Among the boride particles of rare earth elements, for example, lanthanum hexaboride is obtained by heating lanthanum oxide and boron oxide at a high temperature in the presence of carbon, and then pulverized by a dry pulverization device. Note that a method for finely pulverizing powder using a jet mill is disclosed in, for example, Patent Document 1. These boride particles have conventionally been used in thick film resistance pastes and the like, and when made into fine particles, they can be used as an optical material for solar radiation shielding. That is, a film in which boride particles are dispersed can transmit visible light and can efficiently shield near-infrared rays that act as thermal energy, and is known to be suitable as a solar radiation shielding material applied to windows of houses and automobiles (see, for example, Patent Documents 2 and 3). However, since borides of rare earth elements such as La are hard, it has been difficult to pulverize them into fine particles by a dry pulverization method using a jet mill or the like, and there has been a problem that only relatively large particles of about 1 μm to 3 μm can be obtained. In addition, it has been difficult to suppress re-aggregation of the boride particles obtained by the dry pulverization method. Subsequent research has found that by processing with a media agitation mill, the average dispersed particle size of the boride particles can be reduced to 200 nm or less (see, for example, Patent Document 4). As a result, boride particles with an average dispersed particle size of about 200 nm can be obtained economically. When boride particles with an average dispersed particle size of 200 nm or less are used, geometric scattering or Mie scattering that occurs when the particle size is larger than 200 nm can be reduced. For this reason, it becomes possible to prevent the phenomenon of scattering light in the visible light region of 400 nm to 780 nm and becoming cloudy like frosted glass, and an optical member that emphasizes transparency can be obtained. However, as an infrared shielding particle, an infrared shielding optical member in which the above boride particles are dispersed may exhibit a phenomenon of discoloring to bluish white when irradiated with strong light such as sunlight or a spotlight (hereinafter, such a phenomenon may be referred to as "blue haze"). When such blue haze occurs, there are problems such as the possibility of impairing the aesthetic appearance of the infrared shielding optical member. When the average dispersed particle size of the boride particles is 200 nm or less, geometric scattering or Mie scattering is reduced, and it is known that most of the scattering follows Rayleigh scattering defined by the following formula (1). S = [16π ５ r ６ / 3λ ４ ·[(m ２ - 1) / (m ２ + 2)] ２ ·[m] (1) [However, in the above formula (1), S is the scattering coefficient, λ is the wavelength, r is the particle size, m = n １ / n ０ , n ０ is the refractive index of the substrate, and n １ is the refractive index of the dispersed substance] The above Rayleigh scattering is the scattering of light by particles smaller than the wavelength of the light. From the above formula (1), it is understood that Rayleigh scattering is inversely proportional to the fourth power of the wavelength (λ), so it scatters a large amount of blue light with a short wavelength and causes discoloration to bluish white. Also, in the Rayleigh scattering region, from the above formula (1), since the scattered light is proportional to the sixth power of the particle diameter (r), it is understood that by reducing the particle diameter, Rayleigh scattering can be reduced and the occurrence of blue haze can be suppressed. And, for example, Patent Document 5 discloses an example in which the occurrence of blue haze can be suppressed by making the average dispersed particle diameter 85 nm or less. Japanese Patent Application Laid-Open No. 2001-314776, Japanese Patent Application Laid-Open No. 2000-096034, Japanese Patent Application Laid-Open No. 11-181336, Japanese Patent Application Laid-Open No. 2004-237250, Japanese Patent Application Laid-Open No. 2009-150979 V. Domnich et al., J. Am. Ceram. Soc., (2011) vol.94, Issue 11, pp.3605-3628, X.H.Zhao et al., App. Mech. Mater., (2011) vol.55-57, pp.1436-1440 However, when attempting to grind the conventionally used boride particles to an average dispersed particle diameter of 85 nm or less by the grinding method using a media agitation mill disclosed in Patent Document 4, there were cases where the viscosity of the slurry increased and the grinding process became difficult. Therefore, in order to continue the grinding process to further reduce the average dispersed particle diameter and suppress blue haze, it is necessary to extremely lower the concentration of boride particles in the slurry to lower the viscosity, resulting in a problem of poor grinding efficiency and being uneconomical. Therefore, in view of the problems of the above prior art, an aspect of the present invention aims to provide boride particles that can be easily finely ground. According to one aspect of the present invention for solving the above problems, General formula XB ｍ (However, X is one or more metal elements selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr, Ca, and m is a number indicating the amount of boron in the general formula), which are boride particles, provide boride particles in which the carbon content contained in the boride particles when measured by the combustion-infrared absorption method is 0.2% by mass or less. According to one aspect of the present invention, it is possible to provide boride particles that can be easily pulverized. Explanatory drawing (Part 1) showing the measurement principle of the diffusion transmission profile of an infrared-shielding particle dispersion or the like according to an embodiment of the present invention. Explanatory drawing (Part 2) showing the measurement principle of the diffusion transmission profile of an infrared-shielding particle dispersion or the like according to an embodiment of the present invention. Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications and substitutions can be made to the following embodiments without departing from the scope of the present invention. (Boride particles) First, in this embodiment, a configuration example of boride particles will be described. The boride particles of this embodiment have the general formula XB ｍ (where X is one or more metal elements selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr, Ca, and m is a number indicating the amount of boron in the general formula). And the carbon content contained in the above boride particles when measured by the combustion-infrared absorption method can be 0.2 mass% or less. The inventors of the present invention have intensively studied boride particles that can be easily pulverized, that is, pulverized into fine particles. And by setting the carbon content (carbon concentration) in the boride particles to a predetermined value or less, it has been found that boride particles that can be easily pulverized can be obtained, and the present invention has been completed. The boride particles of this embodiment can be particles of a boride represented by the general formula XB as described above. ｍ In the boride particles of this embodiment represented by the above general formula XB ｍ , m, which is the element ratio (molar ratio) of boron (B) to the metal element (X) (B / X), is not particularly limited, but is preferably 3.0 or more and 20.0 or less. Examples of the boride constituting the boride particles represented by the general formula XB ｍ include, for example, XB ４ , XB ６ , XB１２ and the like. However, from the viewpoint of selectively and efficiently reducing the transmittance of light in the near-infrared region around a wavelength of 1000 nm, the boride particles of the present embodiment are XB ４ , or XB ６ is preferably the main component, and may partly contain XB １２ . Therefore, in the general formula XB ｍ , m which is the element ratio (B / X) of boron (B) to the metal element (X) is more preferably 4.0 or more and 6.2 or less. When the above (B / X) is 4.0 or more, the generation of XB, XB ２ and the like can be suppressed. Although the reason is not clear, the solar radiation shielding property can be improved. When the above (B / X) is 6.2 or less, the content ratio of hexaboride, which is particularly excellent in the solar radiation shielding property, can be increased, which is preferable because the solar radiation shielding property is improved. In particular, since the boride particles of the present embodiment have a high ability to absorb near-infrared rays among borides, it is preferable that XB ６ is the main component. Therefore, in the boride particles of the present embodiment represented by the general formula XB ｍ , m which is the element ratio (B / X) of boron (B) to the metal element (X) is more preferably 5.8 or more and 6.2 or less. When boride particles are produced, the powder containing the obtained boride particles is not composed of only particles of a boride having a single composition, but can be particles containing borides of a plurality of compositions. Specifically, for example, particles of a mixture of borides such as XB ４ , XB ６ , XB １２ and the like can be used. Therefore, for example, when X-ray diffraction measurement is performed on particles of hexaboride, which is a typical boride particle, even if it is a single phase in terms of X-ray diffraction analysis, it is considered that actually it contains a trace amount of other phases. Therefore, the general formula XB of the boride particles of the present embodiment ｍIn this case, m can be, for example, the atomic ratio of boron (B) to 1 atom of element X when the powder containing the obtained boride particles is chemically analyzed by ICP emission spectrometry (high-frequency inductively coupled plasma emission spectrometry) or the like. The metal element (X) of the boride particles of the present embodiment is not particularly limited as shown in the above general formula, and can be, for example, one or more metal elements selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr, and Ca. However, since lanthanum hexaboride, which is a lanthanum hexaboride, has particularly high near-infrared absorption ability, the boride particles of the present embodiment preferably contain lanthanum hexaboride particles. And, as described above, according to the studies of the inventors of the present invention, by setting the amount of carbon (carbon concentration) in the boride particles to a predetermined value or less, boride particles that can be easily pulverized can be obtained. The reason for this will be described below. According to the studies of the inventors of the present invention, carbon contained in the boride particles may form a carbon compound with the components of the boride particles, or a carbon compound contained in the raw material may remain. Examples of such carbon compounds include LaB ２ C ２ , LaB ２ C ４ , B ４ C, B ４．５ C, B ５．６ C, B ６．５ C, B ７．７ C, B ９ C, etc. According to Non-Patent Document 1, among the above carbon compounds, B ４ C, B ４．５ C, B ５．６ C, B ６．５ C, B ７．７ C, B ９ C are carbon compounds with high hardness, with Young's moduli, which are indicators of hardness, of 472 GPa, 463 GPa, 462 GPa, 446 GPa, 352 GPa, and 348 GPa, respectively. On the other hand, Non-Patent Document 2 reports that, for example, the Young's modulus of lanthanum hexaboride is 194 GPa. It is presumed that other boride particles also have a Young's modulus of about the same degree. Thus, in some cases, the carbon compound mixed as an impurity may have a higher Young's modulus than the target boride particles. Therefore, in order to obtain boride particles that can be easily pulverized, it is required to suppress the mixing of these carbon compounds. And since the mixing amount (content) of these carbon compounds is correlated with the carbon amount in the boride particles, as described above, it is considered that by setting the carbon amount in the boride particles to a predetermined value or less, boride particles that can be easily pulverized can be obtained. The carbon amount contained in the boride particles of the present embodiment can be measured by the combustion-infrared absorption method. And the carbon amount contained in the boride particles of the present embodiment measured by the combustion-infrared absorption method is preferably 0.2 mass% or less, and more preferably 0.1 mass% or less. In particular, among the above-mentioned carbon compounds in the boride particles, ４ since B ４ C (boron carbide) is likely to be generated, it is also preferable to suppress the amount of B ４ C contained in the boride particles of the present embodiment. For example, the content (content ratio) of B ４ C in the boride particles of the present embodiment is preferably 1.0 mass% or less. By setting the amount of B ４ C, that is, the content ratio of B ４ C in the boride particles of the present embodiment to 1.0 mass% or less, the content of other carbon compounds can also be suppressed, and particularly, boride particles that can be easily pulverized can be obtained, which is preferable. The amount of B ４ C contained in the boride particles of the present embodiment can be measured by ICP analysis after performing a pretreatment of nitric acid dissolution and filtration separation. B ４ C is known to hardly dissolve in nitric acid. On the other hand, boride particles are known to dissolve in nitric acid. Therefore, B in the boride particles ４When evaluating the C content, boride particles are added to nitric acid, the boride particles are dissolved, and then the undissolved residue is separated by filtration, so that only B ４ C particles can be taken out. Then, the separated B ４ C particles are dissolved with sodium carbonate, and the boron concentration is measured by ICP analysis, so that the B ４ C concentration can be calculated. At this time, in order to confirm that the undissolved residue obtained after filtration separation is B ４ C, a sample that has been similarly processed up to filtration separation is prepared in parallel, and the undissolved residue of the sample obtained after filtration separation is measured by XRD to confirm that it is B ４ C single phase. By the way, boride particles such as hexaboride particles are powders colored dark purple or the like, but when pulverized so that the particle size is sufficiently smaller than the visible light wavelength and in a state of being dispersed in the film, the film has visible light transmittance. At the same time, an infrared shielding function is exhibited. The reason for this has not been elucidated in detail, but these boride materials are considered to have a relatively large number of free electrons, and absorption due to interband transitions between 4f - 5d, electron - electron, and electron - phonon interactions exists in the near - infrared region. According to experiments, in a film in which these boride particles are dispersed finely and uniformly enough, it is confirmed that the transmittance of the film has a maximum value in the region of wavelengths from 400 nm to 700 nm and a minimum value in the region of wavelengths from 700 nm to 1800 nm. Considering that the visible light wavelength is from 380 nm to 780 nm and the visual sensitivity has a bell - shaped curve with a peak around 550 nm, it can be understood that such a film effectively transmits visible light and effectively absorbs and reflects other solar radiation. The average dispersed particle size of the boride particles of the present embodiment is preferably 100 nm or less, and more preferably 85 nm or less. Here, the average dispersed particle size can be measured by a particle size measuring device based on the dynamic light scattering method. The lower limit of the average dispersed particle diameter of the boride particles is not particularly limited, but is preferably, for example, 1 nm or more. This is because it is industrially difficult to make the average dispersed particle diameter of the boride particles less than 1 nm. Since the boride particles of the present embodiment described above have a carbon content of a predetermined value or less, they can be easily pulverized to have an average dispersed particle diameter of, for example, 100 nm or less, particularly 85 nm or less. Therefore, the infrared shielding optical member in which the boride particles of the present embodiment are dispersed can suppress the occurrence of blue haze even when irradiated with strong light such as sunlight or a spotlight. (Method for producing boride particles) Next, a configuration example of the method for producing the boride particles of the present embodiment will be described. As the method for producing the boride particles of the present embodiment, the obtained boride particles are represented by the general formula XB ｍ (wherein X is one or more metal elements selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr, Ca), and when the boride particles are measured by the combustion-infrared absorption method, the amount of carbon (carbon concentration) contained in the boride particles is not particularly limited as long as it is 0.2% by mass or less. As a configuration example of the method for producing the boride particles of the present embodiment, for example, a solid-phase reaction method using carbon or boron carbide as a reducing agent can be mentioned. Hereinafter, the case of producing boride particles using lanthanum as a metal element will be described as an example. For example, boride particles using lanthanum as a metal element can be produced by firing a mixture of a boron source, a reducing agent, and a lanthanum source. Specifically, for example, when producing lanthanum boride particles using boron carbide as a boron source and a reducing agent and lanthanum oxide as a lanthanum source, first, a raw material mixture of boron carbide and lanthanum oxide is prepared. Next, the raw material mixture is fired at a temperature of 1500 °C or higher in an inert atmosphere, whereby the lanthanum oxide is reduced by the carbon in the boron carbide, carbon monoxide and carbon dioxide are generated, and the carbon is removed. Further, lanthanum boride is obtained from the remaining lanthanum and boron. Note that the carbon derived from boron carbide is not completely removed as carbon monoxide and carbon dioxide, and a part of it remains in the lanthanum boride particles as impurity carbon. Therefore, increasing the proportion of boron carbide in the raw material increases the impurity carbon concentration in the obtained lanthanum boride particles. As described above, the powder containing the obtained boride particles is not composed only of particles of a boride having a single composition, but is a mixture of particles of LaB ４ , LaB ６ , LaB １２ and the like. Therefore, when the powder containing the obtained boride particles is measured by X-ray diffraction, even if the boride is a single phase in terms of X-ray diffraction analysis, it is considered that actually a trace amount of other phases are contained. Here, when producing boride particles using lanthanum as a metal element as described above, the elemental ratio B / La of boron in the boron source of the raw material and lanthanum in the lanthanum source is not particularly limited, but is preferably 3.0 or more and 20.0 or less. In particular, when the elemental ratio B / La of boron in the boron source of the raw material and lanthanum in the lanthanum source is 4.0 or more, the formation of LaB, LaB ２ and the like can be suppressed. Also, although the reason is not clear, the solar radiation shielding property can be improved. On the other hand, when the elemental ratio B / La of boron in the boron source of the raw material and lanthanum in the lanthanum source is 6.2 or less, the formation of boron oxide particles other than the boride particles is suppressed. Since boron oxide particles are hygroscopic, if boron oxide particles are mixed into the powder containing the boride particles, the moisture resistance of the powder containing the boride particles decreases, and the deterioration of the solar radiation shielding property over time becomes large. For this reason, it is preferable to suppress the formation of boron oxide particles by setting the elemental ratio B / La of boron in the boron source of the raw material and lanthanum in the lanthanum source to 6.2 or less. Also, when the elemental ratio B / La is 6.2 or less, the content ratio of the hexaboride having particularly excellent solar radiation shielding properties can be increased, which is preferable because the solar radiation shielding property is improved. In order to further reduce the impurity carbon concentration, it is effective to reduce the proportion of boron carbide in the raw materials as much as possible. Therefore, for example, by setting B / La to 6.2 or less to produce lanthanum boride particles, a powder containing lanthanum boride particles with an impurity carbon concentration of 0.2% by mass or less can be obtained more reliably. As described above, when producing boride particles using lanthanum as a metal element, it is more preferable that the elemental ratio (molar ratio) B / La of boron in the boron source and lanthanum in the lanthanum source is 4.0 or more and 6.2 or less. By setting the composition of the raw materials within the above range, it is possible to obtain a powder containing lanthanum boride particles that exhibits high solar radiation shielding properties while suppressing the impurity carbon concentration in the powder containing the obtained lanthanum boride particles to a low level. In addition, in particular, the obtained lanthanum boride particles preferably mainly consist of LaB ６ . This is because LaB ６ has particularly high absorption ability for near-infrared rays. Therefore, it is more preferable that the elemental ratio B / La of boron in the boron source of the raw materials and the lanthanum element in the lanthanum source is 5.8 or more and 6.2 or less. Here, the case of producing lanthanum boride particles using boron carbide as the boron source and reducing agent and lanthanum oxide as the lanthanum source has been described as an example, but it is not limited to such a form. For example, boron or boron oxide can be used as the boron source, carbon can be used as the reducing agent, and lanthanum oxide can be used as the lanthanum source. In this case, it is preferable to conduct preliminary tests or the like so that excess carbon and oxygen do not remain in the product, and to select the mixing ratio of each component. In addition, for example, depending on the metal element X contained in the boride particles to be produced, a compound containing the metal element X can be used instead of lanthanum oxide. Examples of the compound containing the metal element X include one or more selected from hydroxides of the metal element X, hydrates of the metal element X, and oxides of the metal element X. The production method of the compound containing the metal element X is not particularly limited, but for example, it can be obtained from a precipitate formed by reacting a solution containing the compound containing the metal element X with an alkaline solution while stirring. As described above, even when a compound containing a metal element X is used instead of lanthanum oxide, it is preferable to conduct preliminary tests or the like and select the mixing ratio of each component so that excess carbon or oxygen does not remain in the product. For example, the elemental ratio of boron in the boron source and the metal element X in the metal element X source can be set to the same ratio as the elemental ratio of boron in the boron source and the lanthanum element in the lanthanum source described above. The obtained boride particles can be made into boride particles having a desired average dispersed particle diameter by, for example, performing wet pulverization or the like. (Boride particle dispersion liquid) Next, a configuration example of the boride particle dispersion liquid of the present embodiment will be described. The boride particle dispersion liquid of the present embodiment can contain the above-described boride particles and a liquid medium. The boride particles are preferably in a dispersed state in the liquid medium, for example. The liquid medium used for the boride particle dispersion liquid can contain one or more selected from water, organic solvents, fats and oils, liquid resins, and plasticizers. The organic solvent preferably has a function of maintaining the dispersibility of the boride particles and a function of not causing coating defects when applying the dispersion liquid. Examples of the organic solvent include alcohol solvents such as methanol (MA), ethanol (EA), 1-propanol (NPA), isopropanol (IPA), butanol, pentanol, benzyl alcohol, and diacetone alcohol; ketone solvents such as acetone, methyl ethyl ketone (MEK), methyl propyl ketone, methyl isobutyl ketone (MIBK), cyclohexanone, and isophorone; ester solvents such as 3-methyl-methoxy-propionate (MMP); glycol derivatives such as ethylene glycol monomethyl ether (MCS), ethylene glycol monoethyl ether (ECS), ethylene glycol isopropyl ether (IPC), propylene glycol methyl ether (PGM), propylene glycol ethyl ether (PE), propylene glycol methyl ether acetate (PGMEA), and propylene glycol ethyl ether acetate (PE-AC); amides such as formamide (FA), N-methylformamide, dimethylformamide (DMF), dimethylacetamide, and N-methyl-2-pyrrolidone (NMP); aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as ethylene chloride and chlorobenzene. One or more of these can be selected and used in combination. Among the above, as the organic solvent, those with higher hydrophobicity such as ketones like MIBK and MEK, aromatic hydrocarbons such as toluene and xylene, and glycol ether acetates such as PGMEA and PE-AC are more preferable. Therefore, it is preferable to select and use one or more of these in combination. Examples of the oil include one or more selected from drying oils such as linseed oil, sunflower oil, and tung oil; semi-drying oils such as sesame oil, cottonseed oil, rapeseed oil, soybean oil, and rice bran oil; non-drying oils such as olive oil, coconut oil, palm oil, and dehydrated castor oil; fatty acid monoesters obtained by directly subjecting fatty acids of vegetable oils and monoalcohols to an ester reaction; ethers; petroleum solvents such as Isopar E, Exxol Hexane, Exxol Heptane, Exxol E, Exxol D30, Exxol D40, Exxol D60, Exxol D80, Exxol D95, Exxol D110, and Exxol D130 (manufactured by ExxonMobil). Examples of the liquid resin include one or more selected from liquid acrylic resins, liquid epoxy resins, liquid polyester resins, and liquid urethane resins. As the plasticizer, for example, a plasticizer for liquid plastics can be used. Examples of the plasticizer for liquid plastics include one or more selected from phthalate plasticizers such as DEHP and DINP; adipate plasticizers such as DIN A and DOA; phosphate plasticizers; epoxy plasticizers; and polyester plasticizers. In addition to the above-described components, the liquid medium used in the boride particle dispersion liquid of the present embodiment can also contain, for example, a dispersant, a coupling agent, a surfactant, and the like. The dispersant, the coupling agent, and the surfactant can be selected according to the application, but preferably have an amine-containing group, a hydroxyl group, a carboxyl group, or an epoxy group as a functional group. These functional groups can adsorb on the surface of the boride particles and prevent aggregation of the boride particles, and exhibit an effect of uniformly dispersing the boride particles, for example, in a boride particle dispersion prepared using the boride particle dispersion liquid. As the dispersant, coupling agent, and surfactant, for example, phosphate ester compounds, polymer-based dispersants, silane-based coupling agents, titanate-based coupling agents, aluminum-based coupling agents, etc. can be preferably used, but are not limited thereto. Examples of the polymer-based dispersants include acrylic polymer dispersants, urethane polymer dispersants, acrylic block copolymer-based polymer dispersants, polyether dispersants, polyester-based polymer dispersants, and the like. The addition amount of one or more materials selected from the dispersant, coupling agent, and surfactant to the boride particle dispersion is preferably in the range of 10 parts by weight or more and 1000 parts by weight or less, more preferably in the range of 20 parts by weight or more and 200 parts by weight or less, based on 100 parts by weight of the boride particles. If the addition amount of the dispersant or the like is within the above range, aggregation of the boride particles in the dispersion can be suppressed, and the dispersion stability can be kept high, which is preferable. The method for dispersing the boride particles in the liquid medium is not particularly limited. For example, there is a method of subjecting the raw material mixture of the boride particle dispersion to a dispersion treatment using a wet media mill such as a bead mill, a ball mill, or a sand mill. In particular, the boride particle dispersion of the present embodiment preferably has a state in which boride particles having an average dispersed particle diameter of 100 nm or less are dispersed in the liquid medium, and the average dispersed particle diameter of the boride particles is more preferably 85 nm or less. Therefore, it is preferable to prepare a dispersion by dispersing the boride particles by a wet grinding method using a media stirring mill such as a bead mill. When preparing a boride particle dispersion in which boride particles are dispersed in a dispersion medium (liquid medium), as described above, the boride particles, the dispersant, etc., which are the raw materials, are added to water, an organic solvent, an oil or fat, a liquid resin, a plasticizer, etc., which are liquid media, and a dispersion treatment is performed using a media stirring mill or the like. Also, a boride particle dispersion can be prepared by the following procedure. Here, the case of preparing a boride particle plasticizer dispersion will be described as an example. Specifically, first, using the aforementioned organic solvent as the liquid medium, a boride particle dispersion liquid in which boride particles are dispersed in the organic solvent is prepared in advance. Next, a plasticizer is added to the boride particle dispersion liquid, and the boride particle plasticizer dispersion liquid can be obtained by removing the organic solvent. As a method for removing the organic solvent, for example, a method of drying the boride particle dispersion liquid under reduced pressure can be mentioned. Specifically, while stirring the boride particle dispersion liquid using the organic solvent as the liquid medium with the plasticizer added, it is dried under reduced pressure to separate the organic solvent component. As the apparatus used for the reduced pressure drying, a vacuum stirring type dryer can be mentioned, but any apparatus having the above functions can be used and is not particularly limited. Also, the pressure value during the reduced pressure is appropriately selected. By using the reduced pressure drying method, the removal efficiency of the organic solvent from the boride particle dispersion liquid using the organic solvent with the plasticizer added as the liquid medium can be improved. Therefore, it is preferable because aggregation of the boride particles dispersed in the boride particle plasticizer dispersion liquid does not occur. Furthermore, the productivity of the boride particle plasticizer dispersion liquid is also increased, and it is easy to recover the evaporated organic solvent, which is also preferable from an environmental consideration. In addition, in order to obtain a uniform boride particle dispersion liquid, various additives or a dispersant as described above may be added, or the pH may be adjusted. Here, the case of preparing a boride particle plasticizer dispersion liquid using a plasticizer as the dispersion medium has been described as an example, but it is not limited to such a form. Instead of the plasticizer, other dispersion media (liquid media) such as water, organic solvents, oils and fats, and liquid resins can be used to obtain a dispersion liquid in which boride particles are dispersed in various dispersion media. The content rate, that is, the concentration of the boride particles in the boride particle dispersion liquid is not particularly limited, but for example, it is preferably 0.01 mass% or more and 30 mass% or less. This is because if the content of the boride particles is 0.01 mass% or more, a boride particle dispersion liquid having sufficient infrared ray shielding ability can be obtained. Also, if the content of the boride particles is 30% by mass or less, the viscosity of the boride particle dispersion liquid does not become too high, and the dispersion stability can be maintained, which is preferable. In particular, the content of the boride particles in the boride particle dispersion liquid is more preferably 1% by mass or more and 30% by mass or less. Also, the boride particles in the boride particle dispersion liquid are preferably dispersed with an average dispersed particle diameter of 100 nm or less as measured by the dynamic light scattering method, and more preferably 85 nm or less. This is because if the average dispersed particle diameter of the boride particles is 100 nm or less, the generation of blue haze in the infrared shielding film produced using the boride particle dispersion liquid according to the present embodiment can be suppressed, and the optical properties can be improved. Further, when the average dispersed particle diameter is 85 nm or less, the generation of blue haze in the infrared shielding film can be particularly suppressed. In addition, when a boride particle dispersion liquid is prepared using the above-described boride particles, the inventors of the present invention speculate as follows about the reason why the average dispersed particle diameter can be efficiently pulverized to 100 nm or less, particularly 85 nm or less, without problems such as gelation of the boride particle dispersion liquid (slurry). Since the boride particles are hard, when pulverizing using a wet medium stirring mill, wear debris such as fine powder of worn media beads and fine bead pieces of crushed media beads are mixed into the slurry. At this time, since the hardness of the boride particles increases with an increase in the carbon concentration, when boride particles having a carbon concentration higher than 0.2% by mass are used as a raw material, a large amount of wear debris of the media beads is mixed into the slurry. The mixing of such wear debris of the media beads is the cause of increasing the viscosity of the slurry. The concentration ratio of the wear debris of the media beads and the boride in the slurry can be used as an index of the media bead wear amount. For example, when yttria-stabilized zirconia beads (also simply referred to as "zirconia beads") known for high wear resistance are used as the media beads, Zr derived from the zirconia beads in the slurry and the general formula XB ｍThe weight concentration (mass %) ratio Zr / X of the metal element X in the boride represented by the following formula can be used as an index of the wear amount of the media beads. When the carbon concentration of the boride particles is higher than 0.2 mass%, the zirconium derived from the zirconia beads and the zirconium compound represented by the general formula XB ｍ The concentration ratio Zr / X of the metal element X in the boride represented by the formula (1) becomes larger than 1.5. In other words, the amount of wear of the media beads becomes very large. The inclusion of wear debris of the media beads causes an increase in the viscosity of the slurry. In contrast, by using boride particles containing 0.2 mass% or less of carbon as a raw material, yttria-stabilized zirconia beads are used as media beads, and when the average dispersed particle size is 100 nm or less, particularly 85 nm or less, the concentration ratio Zr / X in the resulting slurry can be 1.5 or less. In other words, it is presumed that the amount of wear debris mixed into the media beads is greatly reduced, making it possible to efficiently grind the slurry without worsening its viscosity. However, there are many unknown aspects regarding the increase in the viscosity of the slurry, and there is a possibility that other actions are at work, so it is not limited to the above action. In addition, when zirconia beads are used as media beads and the dispersion treatment of the boride particle dispersion liquid is performed, Zr derived from the zirconia beads in the boride particle dispersion liquid and the general formula XB ｍ The concentration ratio Zr / X of the metal element X in the boride represented by the formula (1) is preferably 1.5 or less. That is, the boride particle dispersion liquid may contain zirconia derived from the media beads used during pulverization, and the weight concentration of Zr is preferably 1.5 times or less than the weight concentration of the metal element X in the boride particle dispersion liquid. This is because, when the concentration ratio Zr / X in the boride particle dispersion liquid obtained as described above is 1.5 or less, the increase in viscosity of the boride particles can be sufficiently suppressed. The boride particle dispersion of the present embodiment described above can be used for various applications as an infrared shielding particle dispersion. And the boride particle dispersion of the present embodiment contains the aforementioned boride particles, and can easily have an average dispersed particle diameter of 100 nm or less, particularly 85 nm or less. For this reason, it is possible to suppress the occurrence of blue haze. (Infrared shielding transparent substrate, infrared shielding optical member) A configuration example of the infrared shielding transparent substrate of the present embodiment will be described. The infrared shielding transparent substrate of the present embodiment has a coating layer on at least one surface of the transparent substrate, and the coating layer can contain infrared shielding particles and a binder. And the infrared shielding particles are represented by the general formula XB ｍ (However, X is one or more metal elements selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr, Ca, and m is a number indicating the amount of boron in the general formula), and boride particles having a carbon content of 0.2 mass% or less when measured by the combustion-infrared absorption method can be used. The infrared shielding transparent substrate of the present embodiment can have, as described above, a transparent substrate and a coating layer disposed on at least one surface of the transparent substrate. And the coating layer can contain infrared shielding particles and a binder. Each component will be described below. (1) Regarding infrared shielding particles and their manufacturing method. As the infrared shielding particles, the aforementioned boride particles can be used, and thus the description thereof is omitted here. (2) Binder As described above, since the coating layer can contain a binder, the binder will be described next. As the binder, for example, an ultraviolet (UV) curable resin, a thermoplastic resin, a thermosetting resin, an electron beam curable resin, a room temperature curable resin, etc. can be selected according to the purpose. In particular, it is preferable that the binder contains one or more selected from an ultraviolet (UV) curable resin, a thermoplastic resin, a thermosetting resin, and a room temperature curable resin. As the binder, specifically, polyethylene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, polystyrene resin, polypropylene resin, ethylene vinyl acetate copolymer, polyester resin, polyethylene terephthalate resin, fluororesin, polycarbonate resin, acrylic resin, polyvinyl butyral resin, etc. can be mentioned. As the binder, for example, one kind or a combination of two or more kinds selected from the above resin group can be used. However, as the binder for the coating layer described above, among the above resin group, it is particularly preferable to use a UV curable resin from the viewpoints of productivity and equipment cost. In addition, instead of the resin-based binder, an inorganic binder using a metal alkoxide can also be used. As the metal alkoxide, alkoxides of Si, Ti, Al, Zr, etc. can be mentioned as typical materials. The inorganic binder using these metal alkoxides can form a coating layer of an oxide film by hydrolysis and polycondensation by heating or the like. Furthermore, the above resin-based binder and the above inorganic binder may be used in combination. (3) Transparent substrate The infrared shielding transparent substrate of this embodiment can have a coating layer on at least one surface of the transparent substrate. Therefore, next, a configuration example of the transparent substrate will be described. As the transparent substrate, for example, a transparent film substrate or a transparent glass substrate can be preferably used. The transparent film substrate is not limited to the film shape, and for example, it may be in the form of a board or a sheet. The material of the transparent film substrate is not particularly limited, but for example, one or more selected from polyester, acrylic, urethane, polycarbonate, polyethylene, ethylene vinyl acetate copolymer, vinyl chloride, fluororesin, etc. can be used. As the transparent film substrate, a polyester film is preferable, and a polyethylene terephthalate (PET) film is more preferable. Also, the transparent glass substrate is not particularly limited, and transparent glass substrates such as silica glass and soda glass can be used. In addition, the surface of the transparent substrate is preferably surface-treated in order to improve the coatability of the infrared-shielding particle dispersion liquid and the adhesion to the coating layer. Further, in order to improve the adhesiveness between the transparent substrate and the coating layer, an intermediate layer can be formed on the transparent substrate, and a coating layer can be formed on the intermediate layer. The configuration of the intermediate layer is not particularly limited, and it can be constituted by, for example, a polymer film, a metal layer, an inorganic layer (for example, an inorganic oxide layer such as silica, titania, zirconia, etc.), an organic / inorganic composite layer, or the like. As described above, the infrared-shielding transparent substrate of the present embodiment has a coating layer on at least one surface of the transparent substrate, and the coating layer can contain infrared-shielding particles and a binder. The coating layer may be composed only of infrared-shielding particles and a binder, but can also contain other components. For example, since the coating layer can be produced using an infrared-shielding particle dispersion liquid as described later, a solvent, a dispersant, a coupling agent, a surfactant, etc. can be added to the infrared-shielding particle dispersion liquid. Therefore, the coating layer may contain the components added to the infrared-shielding particle dispersion liquid and the components derived from the added components. In addition, in order to further impart an ultraviolet-shielding function to the infrared-shielding transparent substrate of the present embodiment, at least one type or more of ultraviolet-shielding materials selected from inorganic titanium oxide, zinc oxide, cerium oxide, etc., and organic benzophenone, benzotriazole, etc. may be added to the coating layer. Note that the above ultraviolet-shielding material is not limited to the form of being added to the coating layer, and a layer containing the ultraviolet-shielding material separately can also be formed. When forming a layer containing the ultraviolet-shielding material, the arrangement of the layer is not particularly limited, but it can be formed, for example, on the coating layer. In addition, in order to improve the visible light transmittance of the infrared ray shielding transparent base material according to the present embodiment, one or more types of particles selected from ATO, ITO, zinc oxide added with aluminum, and indium tin composite oxide may be further mixed into the coating layer. By adding these transparent particles to the coating layer, while the transmittance in the vicinity of a wavelength of 750 nm increases, infrared light with a wavelength longer than 1200 nm is shielded, so that a heat ray shielding body with a high transmittance of near-infrared light and high heat ray shielding characteristics can be obtained. Note that the form of adding one or more types of particles selected from the above ATO and the like is not limited to being added to the coating layer, and a layer containing such particles can also be formed separately from the coating layer. The thickness of the coating layer on the transparent base material is not particularly limited, but in practical use, it is preferably 20 μm or less, and more preferably 6 μm or less. This is because if the thickness of the coating layer is 20 μm or less, in addition to exhibiting sufficient pencil hardness and having scratch resistance, when the solvent volatilizes and the binder cures in the coating layer, process abnormalities such as warping of the substrate film can be avoided. Note that the lower limit value of the thickness of the coating layer is not particularly limited, but for example, it is preferably 10 nm or more, and more preferably 50 nm or more. The content of the infrared ray shielding particles contained in the coating layer is not particularly limited, but the content per projected area of the transparent base material / coating layer is 0.01 g / m ２ or more and 1.0 g / m ２ or less is preferable. This is because if the content is 0.01 g / m ２ or more, the heat ray shielding characteristics can be significantly exhibited as compared with the case where no infrared ray shielding particles are contained, and if the content is 1.0 g / m ２ or less, the infrared ray shielding transparent base material can sufficiently maintain the transmittance of visible light. In addition, the infrared ray shielding transparent base material of the present embodiment preferably has a maximum value of the diffusion transmittance profile in the region of 360 nm or more and 500 nm or less of 1.5% or less when the visible light (wavelength 400 nm or more and 780 nm or less) transmittance of the coating layer is set to 45% or more and 55% or less. In addition, when a transparent substrate having a sufficient visible light transmittance is used and the transparent substrate has almost no influence on the visible light transmittance of the infrared shielding transparent substrate, that is, for example, when a transparent substrate having a visible light transmittance of 90% or more is used, the visible light transmittance of the coating layer may be read as the visible light transmittance of the infrared shielding transparent substrate. Here, a method for evaluating blue haze will be described. There is no known method for directly measuring blue haze. However, the applicant of the present invention has already proposed a method for evaluating "blue haze" by paying attention to the components of transmitted light, that is, direct incident light and scattered light, when light is applied to a sample such as an infrared shielding particle dispersion, and obtaining the diffuse transmittance for each wavelength (see Patent Document 5). Hereinafter, the principle of measuring the diffuse transmittance for each wavelength, that is, the diffuse transmittance profile, will be described with reference to FIGS. 1 and 2. First, a measuring device for measuring the diffuse transmittance profile will be described with reference to FIGS. 1 and 2. As shown in FIGS. 1 and 2, the measuring device 10 includes an integrating sphere 14. The integrating sphere 14 has a spherical inner surface with diffuse reflectivity, and has a first opening 141 to which a measurement sample 12 (see FIG. 2) is attached, a second opening 142 to which a standard reflector 15 or a light trap component 16 is attached, and a third opening 143 to which a light receiver 13 is attached. The measuring device 10 also includes a light source 11 that emits direct light incident into the spherical space through the first opening 141, a spectroscope (not shown) that is attached to the light receiver 13 and spectrally analyzes the received reflected light or scattered light, a data storage means (not shown) that is connected to the spectroscope and stores the spectral data of the spectrally analyzed reflected light or scattered light, and a calculation means (not shown) that calculates the ratio of the diffuse transmittance light intensity to the blank transmittance light intensity for each wavelength from the stored spectral data of the blank transmittance light intensity and the diffuse transmittance light intensity to obtain the diffuse transmittance for each wavelength. Here, the integrating sphere 14 has diffusive reflectivity with, for example, barium sulfate or Spectralon (registered trademark) coated on the inner surface of the spherical body. The incident angle to the standard reflector 15 can be, for example, 10° on both the standard side and the control side. As the light receiver 13, for example, a photomultiplier tube (ultraviolet / visible region) or one using cooled lead sulfide (near-infrared region) can be used. Also, for the spectroscope (not shown) attached to the light receiver 13, a wavelength measurement range and photometric accuracy (±0.002 Abs) in the ultraviolet / visible region are required. Next, as the light source 11 that emits linearly polarized light incident into the spherical space, for example, a deuterium lamp can be applied in the ultraviolet region, and a 50 W halogen lamp can be applied in the visible / near-infrared region. Also, for the standard reflector 15, for example, a white plate made of Spectralon can be used. The light trap component 16 needs to have a function of trapping the incident linearly polarized light without reflecting it. For example, a dark box that almost completely absorbs the incident linearly polarized light is used. Then, using the above-described diffusive transmission profile measuring device, the maximum value of the diffusive transmission profile of an infrared-shielding transparent base material or the like, which is a measurement sample, can be evaluated through each of the blank transmitted light intensity measurement step, the diffusive transmitted light intensity measurement step, and the diffusive transmittance calculation step. First, in the blank transmitted light intensity measurement step, as shown in FIG. 1, the standard reflector 15 is attached to the second opening 142 of the integrating sphere 14, and linearly polarized light from the light source 11 is made to enter the spherical space through the first opening 141 with no measurement sample attached to the first opening 141. Then, the reflected light reflected by the standard reflector 15 is received by the light receiver 13, and the reflected light is spectroscopically analyzed by a spectroscope (not shown) attached to the light receiver 13 to obtain spectroscopic data of the reflected light. The spectroscopic data at this time becomes the blank transmitted light intensity. Next, in the above-described diffused transmitted light intensity measurement step, as shown in FIG. 2, a light trap component 16 is attached to the second opening 142 of the integrating sphere 14. Then, with the measurement sample 12 attached to the first opening 141, direct light from the light source 11 is made to enter the spherical space through the measurement sample 12 and the first opening 141, and the light receiver 13 receives scattered light other than the light trapped by the light trap component 16. At this time, the scattered light is spectroscopically analyzed by a spectroscope (not shown) attached to the light receiver 13 to obtain spectroscopic data of the scattered light. The spectroscopic data at this time becomes the diffused transmitted light intensity. Then, in the above-described diffused transmittance calculation step, based on the spectroscopic data of the blank transmitted light intensity and the diffused transmitted light intensity stored by data storage means (not shown), an arithmetic means (not shown) calculates the ratio of the diffused transmitted light intensity to the blank transmitted light intensity for each wavelength to obtain the diffused transmittance for each wavelength, and from the obtained diffused transmittance for each wavelength, the maximum value in the wavelength range of 360 nm to 500 nm in the diffused transmission profile of the measurement sample 12 can be obtained. Here, in the measuring apparatus for measuring the diffused transmission profile, an optical system for adjusting the light beam may be provided between the light source 11 and the measurement sample 12. In this optical system, for example, a plurality of lenses are combined to adjust parallel light, and the light quantity is adjusted by a diaphragm. In some cases, a specific wavelength may be cut off by a filter. Then, in the infrared-shielding transparent base material of the present embodiment, when the visible light (wavelength: 400 nm or more and 780 nm or less) transmittance of the coating layer is set to any value between 45% and 55% as described above, it is preferable that the maximum value of the diffused transmission profile in the wavelength range of 360 nm or more and 500 nm or less is 1.5% or less. This is because it has been confirmed that almost no blue haze is observed in the infrared-shielding transparent base material that satisfies the above conditions. The reason why the visible light transmittance of the coating layer is set to be 45% or more and 55% or less is to specify the measurement conditions of the diffusion transmittance (diffusion transmittance profile). Since the diffusion transmittance is proportional to the visible light transmittance, a range is set. In addition, the reason for measuring the diffusion transmittance (diffusion transmittance profile) in the region of a wavelength of 360 nm or more and 500 nm or less is that scattering in that region is exactly the cause of blue haze. If the maximum value of the diffusion transmittance within the above range is 1.5% or less, blue haze is not observed visually experimentally. The infrared ray shielding transparent base material of the present embodiment can be used for various optical members, for example, and an infrared ray shielding optical member including the infrared ray shielding transparent base material of the present embodiment can be formed. Examples of the infrared ray shielding optical member here include windows of buildings and windows of automobiles. According to the infrared ray shielding transparent base material of the present embodiment and the infrared ray shielding optical member including the infrared ray shielding transparent base material described above, an infrared ray shielding transparent base material using boride particles that can be easily pulverized can be obtained. Therefore, the average dispersed particle diameter of the infrared ray shielding particles contained in the coating layer can be made sufficiently small, and the generation of blue haze can be suppressed. (Manufacturing method of infrared ray shielding transparent base material) The infrared ray shielding transparent base material of the present embodiment can be manufactured using, for example, an infrared ray shielding particle dispersion liquid. Therefore, here, first, the infrared ray shielding particle dispersion liquid and its manufacturing method will be described. (1) Infrared ray shielding particle dispersion liquid and its manufacturing method As described above, the infrared ray shielding transparent base material of the present embodiment can be manufactured using an infrared ray shielding particle dispersion liquid containing the boride particles, which are the infrared ray shielding particles described so far. Therefore, here, a configuration example of the infrared ray shielding particle dispersion liquid and its manufacturing method will be described. The infrared ray shielding particle dispersion liquid is obtained by dispersing the above-described infrared ray shielding particles in a solvent. The infrared ray shielding particle dispersion liquid is obtained by adding the above-described infrared ray shielding particles, that is, boride particles, an appropriate amount of a dispersant, a coupling agent, a surfactant, etc. to a solvent and performing a dispersion treatment to disperse the infrared ray shielding particles in the solvent. For the solvent of the infrared ray shielding particle dispersion liquid, a function for maintaining the dispersibility of the infrared ray shielding particles and a function for not causing coating defects when applying the dispersion liquid are required. Specifically, alcohol solvents such as methanol (MA), ethanol (EA), 1-propanol (NPA), isopropanol (IPA), butanol, pentanol, benzyl alcohol, and diacetone alcohol, ketone solvents such as acetone, methyl ethyl ketone (MEK), methyl propyl ketone, methyl isobutyl ketone (MIBK), cyclohexanone, and isophorone, ester solvents such as 3-methyl-methoxy-propionate (MMP), glycol derivatives such as ethylene glycol monomethyl ether (MCS), ethylene glycol monoethyl ether (ECS), ethylene glycol isopropyl ether (IPC), propylene glycol methyl ether (PGM), propylene glycol ethyl ether (PE), propylene glycol methyl ether acetate (PGMEA), and propylene glycol ethyl ether acetate (PE-AC), amides such as formamide (FA), N-methylformamide, dimethylformamide (DMF), dimethylacetamide, and N-methyl-2-pyrrolidone (NMP), aromatic hydrocarbons such as toluene and xylene, and halogenated hydrocarbons such as ethylene chloride and chlorobenzene can be mentioned, and one type selected from these or a combination of two or more types can be used. Among the above, as the solvent, those with high hydrophobicity such as ketones such as MIBK and MEK, aromatic hydrocarbons such as toluene and xylene, and glycol ether acetates such as PGMEA and PE-AC are more preferable. For this reason, it is more preferable to use one type or a combination of two or more types selected from these. In addition, in order to form a coating layer on a transparent substrate such as a transparent film substrate or a transparent glass substrate, it is preferable to select an organic solvent with a low boiling point as the solvent. This is because when the solvent is an organic solvent with a low boiling point, the solvent can be easily removed in the drying process after coating, and the properties of the coating layer, such as hardness and transparency, are not impaired. Specifically, for example, it is preferable to use one or a combination of two or more selected from ketones such as methyl isobutyl ketone and methyl ethyl ketone, and aromatic hydrocarbons such as toluene and xylene. The dispersant, coupling agent, and surfactant can be selected according to the use, but preferably have an amine-containing group, hydroxyl group, carboxyl group, or epoxy group as a functional group. These functional groups adsorb on the surface of the infrared-shielding particles and prevent aggregation of the infrared-shielding particles, so that when a coating layer is formed on a transparent substrate or when an infrared-shielding particle dispersion or the like described later is formed, the infrared-shielding particles are uniformly dispersed in the coating layer or the infrared-shielding particle dispersion. As the dispersant, coupling agent, and surfactant, phosphate ester compounds, polymer dispersants, silane coupling agents, titanate coupling agents, aluminum coupling agents, etc. can be preferably used. Examples of the polymer dispersant include acrylic polymer dispersants, urethane polymer dispersants, acrylic block copolymer polymer dispersants, polyether dispersants, polyester polymer dispersants, etc. However, the dispersant, coupling agent, and surfactant are not limited to these, and various dispersants, coupling agents, and surfactants can be used. The addition amount of one or more materials selected from the dispersant, coupling agent, and surfactant to the infrared-shielding particle dispersion liquid is preferably in the range of 10 parts by weight or more and 1000 parts by weight or less, and more preferably in the range of 20 parts by weight or more and 200 parts by weight or less, based on 100 parts by weight of the boride particles, which are the infrared-shielding particles. If the addition amount of the dispersant or the like is within the above range, the infrared-shielding particles will not aggregate in the dispersion liquid, and the dispersion stability will be maintained. The method of dispersing boride particles, which are infrared-shielding particles, in a solvent (liquid medium) is not particularly limited. For example, there is a method of subjecting a raw material mixture of an infrared-shielding particle dispersion liquid to a dispersion treatment using a wet media mill such as a bead mill, a ball mill, or a sand mill. In particular, the infrared-shielding particle dispersion liquid of the present embodiment preferably has a state in which infrared-shielding particles having an average dispersed particle diameter of 100 nm or less are dispersed in a solvent (liquid medium), and the average dispersed particle diameter of the infrared-shielding particles is more preferably 85 nm or less. For this reason, it is preferable to prepare a dispersion liquid by dispersing boride particles by a wet grinding method using a media stirring mill such as a bead mill. In order to obtain a uniform infrared-shielding particle dispersion liquid, various additives and dispersants may be added, or the pH may be adjusted. The content of the infrared-shielding particles in the above-described infrared-shielding particle dispersion liquid is preferably 0.01% by mass or more and 30% by mass or less. This is because if the content of the infrared-shielding particles is 0.01% by mass or more, a coating layer having infrared-shielding ability can be formed on the transparent substrate. Further, if the content of the infrared-shielding particles is 30% by mass or less, the infrared-shielding dispersion liquid can be easily applied on the transparent substrate, and the productivity of the coating layer can be increased. Further, the infrared-shielding particles in the infrared-shielding particle dispersion liquid are preferably dispersed with an average dispersed particle diameter of 100 nm or less, and more preferably 85 nm or less. If the average dispersed particle diameter of the infrared-shielding particles is 100 nm or less, the generation of blue haze in the infrared-shielding transparent substrate produced using the infrared-shielding particle dispersion liquid according to the present embodiment can be suppressed, and the optical characteristics can be improved. Further, when the average dispersed particle diameter is 85 nm or less, the generation of blue haze in the infrared-shielding transparent substrate can be particularly suppressed. In addition, when an infrared-shielding particle dispersion liquid is prepared using the above-described boride particles, the inventors of the present invention speculate as follows about the reason why the average dispersed particle diameter can be efficiently pulverized to 100 nm or less, particularly 85 nm or less, without problems such as gelation of the infrared-shielding particle dispersion liquid (slurry). Since boride particles are hard, when they are pulverized using a wet media agitation mill, wear debris such as fine powder of worn media beads and fine bead fragments of crushed media beads are mixed into the slurry. At this time, since the hardness of the boride particles increases with an increase in carbon concentration, when boride particles containing a carbon concentration higher than 0.2 mass% are used as the raw material, a large amount of wear debris of the media beads is mixed into the slurry. The mixing of such wear debris of the media beads causes an increase in the viscosity of the slurry. In contrast, by using boride particles containing 0.2 mass% or less of carbon as a raw material, when the average dispersed particle size is pulverized to 100 nm or less, particularly 85 nm or less, the amount of wear debris from the media beads is greatly reduced, so it is presumed that efficient pulverization is possible without worsening the viscosity of the slurry. However, there are many aspects of the increase in the viscosity of the slurry that are not yet understood, and there may be other actions at work, so it is not limited to the above actions. (2) Manufacturing method of infrared shielding transparent substrate Next, a configuration example of the method for producing the infrared shielding transparent substrate of this embodiment will be described. The infrared shielding transparent substrate of the present embodiment can be produced by forming a coating layer containing infrared shielding particles on a transparent substrate using the above-mentioned infrared shielding particle dispersion liquid. An example of a specific procedure will be described below. A binder is added to the above-mentioned infrared shielding particle dispersion liquid to obtain a coating liquid. The obtained coating liquid is coated on the surface of a transparent substrate, and then the solvent is evaporated and the binder is cured by a predetermined method, whereby a coating layer in which the infrared shielding particles are dispersed in a medium can be formed. Alternatively, a coating liquid having an adjusted concentration may be prepared without adding a binder to the infrared shielding particle dispersion liquid, and the coating liquid may be coated on a transparent substrate, followed by evaporating the solvent. Thereafter, the coating liquid containing the binder may be overcoated, and the solvent may be evaporated to form a coating layer. The binder and the transparent substrate that can be suitably used in the coating layer have already been described, and therefore a description thereof will be omitted here. In addition, the surface of the transparent substrate is preferably surface-treated in order to improve the coatability of the infrared-shielding particle dispersion liquid and the adhesion to the coating layer. Further, in order to improve the adhesion between the transparent substrate and the coating layer, an intermediate layer can be formed on the transparent substrate, and a coating layer can be formed on the intermediate layer. The configuration of the intermediate layer is not particularly limited, and for example, it can be composed of a polymer film, a metal layer, an inorganic layer (for example, an inorganic oxide layer such as silica, titania, zirconia, etc.), an organic / inorganic composite layer, or the like. The method of providing the coating layer on the transparent substrate is not particularly limited as long as it is a method capable of uniformly applying the infrared-shielding particle dispersion liquid to the surface of the transparent substrate. For example, a bar coating method, a gravure coating method, a spray coating method, a dip coating method, etc. can be mentioned. For example, when a UV curable resin is used as the binder contained in the infrared-shielding particles and the coating layer is formed by the bar coating method, it is preferable to appropriately adjust the liquid concentration and additives of the infrared-shielding particle dispersion liquid so as to have appropriate leveling properties. Then, the wire bar of the bar number can be selected so that the thickness of the coating layer and the content of the infrared-shielding particles can achieve the purpose of the obtained infrared-shielding transparent substrate, and a coating film can be formed on the transparent substrate. Next, after removing the organic solvent contained in the coating film by drying, the coating layer can be formed on the transparent substrate by irradiating with ultraviolet rays to cure it. At this time, the drying conditions of the coating film vary depending on each component, the type and use ratio of the solvent, but for example, it can be carried out by heating at a temperature of 60°C to 140°C for about 20 seconds to 10 minutes. The method of irradiating ultraviolet rays is not particularly limited, and for example, a UV exposure machine such as an ultra-high pressure mercury lamp can be preferably used. In addition, the adhesion between the transparent substrate and the coating layer, the smoothness of the coating film during coating, the drying property of the organic solvent, etc. can also be controlled by the processes before and after the formation of the coating layer. Examples of the before and after processes include a surface treatment process of the transparent substrate, a pre-bake (preheating of the substrate) process, a post-bake (post-heating of the substrate) process, etc., which can be appropriately selected. The heating temperature in the pre-bake process and / or the post-bake process is preferably 80°C or higher and 200°C or lower, and the heating time is preferably 30 seconds or longer and 240 seconds or shorter. Since the suitable ranges of the thickness of the coating layer to be formed and the content of the infrared-shielding particles in the coating layer have been described above, the description is omitted here. In addition, in order to further impart an ultraviolet-shielding function to the infrared-shielding transparent substrate of the present embodiment, at least one kind of particles such as inorganic titanium oxide, zinc oxide, cerium oxide, or organic benzophenone, benzotriazole, etc. may be added to the coating layer. In addition, in order to improve the visible light transmittance of the infrared-shielding transparent substrate according to the present embodiment, one or more kinds of particles selected from ATO, ITO, aluminum-added zinc oxide, indium tin composite oxide may be further mixed into the coating layer. By adding these transparent particles to the coating layer, while the transmittance near a wavelength of 750 nm increases, infrared light with a wavelength longer than 1200 nm is shielded, so that a heat-ray shielding body with a high transmittance of near-infrared light and high heat-ray shielding characteristics can be obtained. According to the manufacturing method of the infrared-shielding transparent substrate of the present embodiment described above, an infrared-shielding transparent substrate using boride particles that can be easily pulverized can be manufactured. According to such an infrared-shielding transparent substrate, the average dispersed particle diameter of the infrared-shielding particles contained in the coating layer can be made sufficiently small, and the generation of blue haze can be suppressed. (Infrared-shielding particle dispersion) One configuration example of the infrared-shielding particle dispersion of the present embodiment will be described. The infrared-shielding particle dispersion of the present embodiment can contain boride particles and a thermoplastic resin. Here, as the boride particles, the general formula XB ｍ(However, X represents one or more metal elements selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr, Ca, and m represents the amount of boron in the general formula), and the carbon content measured by the combustion-infrared absorption method can be 0.2% by mass or less. Each component will be described below. (1) Boride particles (infrared shielding particles) and a method for producing the same Since the aforementioned boride particles can be used, the description thereof will be omitted here. (2) Thermoplastic resin As described above, the infrared shielding particle dispersion of the present embodiment can contain a thermoplastic resin. The thermoplastic resin is not particularly limited, and various thermoplastic resins can be used according to applications and the like. For example, when applying the infrared shielding particle dispersion of the present embodiment to various window materials, it is preferably a thermoplastic resin having sufficient transparency. Specifically, the thermoplastic resin is preferably one selected from the resin group consisting of polyethylene terephthalate resin, polycarbonate resin, acrylic resin, styrene resin, polyamide resin, polyethylene resin, vinyl chloride resin, olefin resin, epoxy resin, polyimide resin, fluororesin, ethylene-vinyl acetate copolymer, ionomer resin, polyvinyl butyral resin, polyvinyl acetal resin, or a mixture of two or more resins selected from the above resin group, or a copolymer of two or more resins selected from the above resin group, and more preferably one or more selected. Also, for example, when using the infrared shielding particle dispersion of the present embodiment as a board-shaped window material as it is, the thermoplastic resin preferably has high transparency and satisfies general characteristics required for window materials, that is, requirements such as rigidity, light weight, long-term durability, and low cost. In this case, the thermoplastic resin is preferably one or more selected from, for example, polyethylene terephthalate resin, polycarbonate resin, ionomer resin, acrylic resin, and more preferably polycarbonate resin. On the other hand, when the infrared shielding particle dispersion of the present embodiment is used as an intermediate layer of an infrared shielding laminated transparent substrate described later, from the viewpoints of adhesion to the transparent substrate, weather resistance, penetration resistance, etc., as the thermoplastic resin, polyvinyl acetal resin or ethylene-vinyl acetate copolymer can be preferably used. In particular, in this case, the thermoplastic resin is more preferably polyvinyl butyral resin. Further, when the infrared shielding particle dispersion of the present embodiment is used as an intermediate layer, and the thermoplastic resin constituting the infrared shielding particle dispersion does not sufficiently have flexibility or adhesion to the transparent substrate alone, for example, when the thermoplastic resin is a polyvinyl acetal resin, it is preferable to further add a plasticizer. The plasticizer is not particularly limited, and a substance that functions as a plasticizer for the thermoplastic resin used can be used. For example, as a plasticizer used for polyvinyl acetal resin, plasticizers that are compounds of monohydric alcohol and organic acid ester, plasticizers that are ester-based such as polyhydric alcohol organic acid ester compounds, plasticizers that are phosphoric acid-based such as organic phosphoric acid-based plasticizers, etc. can be mentioned. Any plasticizer is preferably liquid at room temperature. Among them, plasticizers that are ester compounds synthesized from polyhydric alcohol and fatty acid are preferable. As described above, the infrared shielding particle dispersion of the present embodiment can contain boride particles and a thermoplastic resin, and for example, it can have a form in which the above-described boride particles are dispersed in the thermoplastic resin. In addition, the infrared shielding particle dispersion of the present embodiment can contain arbitrary components as necessary in addition to boride particles and the thermoplastic resin. For example, as described above, it can also contain a plasticizer, any additive component added in the process of manufacturing the infrared shielding particle dispersion, and components derived from the additive component. Further, in order to further impart ultraviolet shielding ability to the infrared shielding particle dispersion of the present embodiment, at least one kind or more of inorganic titanium oxide, zinc oxide, cerium oxide, etc., and organic benzophenone, benzotriazole, etc. may be added to the infrared shielding particle dispersion. In addition, in order to improve the visible light transmittance of the infrared ray shielding particle dispersion according to the present embodiment, one or more types of particles selected from ATO, ITO, aluminum-added zinc oxide, and indium tin composite oxide may be further mixed. By adding these transparent particles to the infrared ray shielding particle dispersion, the transmittance in the vicinity of a wavelength of 750 nm increases, while infrared light having a wavelength longer than 1200 nm is shielded. Thus, an infrared ray shielding particle dispersion having a high transmittance of near-infrared light and a high heat ray shielding property can be obtained. The content of the boride particles, which are the infrared ray shielding particles contained in the infrared ray shielding particle dispersion, is not particularly limited. However, the content of the boride particles per unit projected area is 0.01 g / m ２ or more and 1.0 g / m ２ or less. This is because when the content is 0.01 g / m ２ or more, the heat ray shielding property can be significantly exhibited as compared with the case where the boride particles, which are the infrared ray shielding particles, are not contained. When the content is 1.0 g / m ２ or less, the infrared ray shielding particle dispersion can sufficiently maintain the visible light transmittance. The optical properties of the infrared ray shielding particle dispersion of the present embodiment are not particularly limited. However, when the maximum transmittance in the visible light wavelength region is 70%, the transmittance of near-infrared light having a wavelength of 850 nm is preferably 23% or more and 45% or less, and the minimum value of the transmittance of heat rays having a wavelength of 1200 nm or more and 1800 nm or less is preferably 15% or less. Here, as a method for adjusting the maximum transmittance in the visible light wavelength region to 70%, methods such as adjusting the content of the boride particles, which are the infrared ray shielding particles, in the infrared ray shielding particle dispersion and the thickness of the infrared ray shielding particle dispersion can be mentioned. Specifically, it can be easily performed by adjusting the concentration of the infrared ray shielding particles contained in the infrared ray shielding particle dispersion powder, the infrared ray shielding particle plasticizer dispersion liquid, or the masterbatch described later, the addition amount of the infrared ray shielding particle dispersion powder, the infrared ray shielding particle plasticizer dispersion liquid, or the masterbatch when preparing the resin composition, and further, the film thickness of the film or sheet. The shape of the infrared shielding particle dispersion of the present embodiment is not particularly limited. For example, it can have a plate shape, specifically, it can be in the form of a sheet, a board, or a film. Note that the infrared shielding particle dispersion of the present embodiment can also be referred to as an infrared shielding film, an infrared shielding sheet, etc. according to its shape. In addition, when the visible light (wavelength 400 nm or more and 780 nm or less) transmittance of the infrared shielding particle dispersion of the present embodiment is set to 45% or more and 55% or less, it is preferable that the maximum value of the diffuse transmittance profile in the region of wavelength 360 nm or more and 500 nm or less is 1.5% or less. Since the method for evaluating blue haze has already been described, the description will be omitted here. As described above, although there is no known method for directly measuring blue haze, the applicant of the present invention has already proposed a method for evaluating "blue haze" by focusing on the components of transmitted light, i.e., direct incident light and scattered light, when light is applied to the infrared shielding particle dispersion as a sample, and obtaining the diffuse transmittance for each wavelength, which is described in this specification. Then, when the visible light (wavelength 400 nm or more and 780 nm or less) transmittance of the infrared shielding particle dispersion of the present embodiment is set to any value of 45% or more and 55% or less as described above, it is preferable that the maximum value of the diffuse transmittance profile in the region of wavelength 360 nm or more and 500 nm or less is 1.5% or less. This is because it has been confirmed that almost no blue haze is observed in the infrared shielding particle dispersion that satisfies the above conditions. Note that the visible light transmittance of the infrared shielding particle dispersion is set to 45% or more and 55% or less in order to specify the measurement conditions of the diffuse transmittance (diffuse transmittance profile). Since the diffuse transmittance is proportional to the visible light transmittance, the range is set. Also, the reason for measuring the diffuse transmittance (diffuse transmittance profile) in the region of wavelength 360 nm or more and 500 nm or less is that scattering in that region is exactly the cause of blue haze. If the maximum value of the diffuse transmittance in the above range is 1.5% or less, blue haze is not observed visually experimentally. According to the infrared ray shielding particle dispersion of the present embodiment described above, an infrared ray shielding particle dispersion using boride particles that can be easily pulverized can be obtained. Therefore, the average dispersed particle diameter of the boride particles, which are the infrared ray shielding particles contained therein, can be made sufficiently small, and the generation of blue haze can be suppressed. (Method for producing infrared ray shielding particle dispersion powder, masterbatch, and infrared ray shielding particle dispersion) (1) Infrared ray shielding particle dispersion liquid and method for producing the same The infrared ray shielding particle dispersion of the present embodiment can be produced using the infrared ray shielding particle dispersion liquid containing the boride particles described so far as the infrared ray shielding particles. Therefore, here, a configuration example of the infrared ray shielding particle dispersion liquid and a method for producing the same will be described. The infrared ray shielding particle dispersion liquid is obtained by dispersing the above-described boride particles in a solvent. The infrared ray shielding particle dispersion liquid is obtained by adding the above-described boride particles, which are infrared ray shielding particles, an appropriate amount of a dispersant, a coupling agent, a surfactant, etc. to a solvent and performing a dispersion treatment to disperse the boride particles in the solvent. Since the same materials as those described in the method for producing an infrared ray shielding transparent base material can be used for the infrared ray shielding particle dispersion liquid, the description thereof will be omitted here. The content of the boride particles, which are infrared ray shielding particles, in the infrared ray shielding particle dispersion liquid is preferably 0.01% by mass or more and 30% by mass or less. This is because if the content of the infrared ray shielding particles is 0.01% by mass or more, an infrared ray shielding particle dispersion having sufficient infrared ray shielding ability can be formed. Also, if the content of the infrared ray shielding particles is 30% by mass or less, the infrared ray shielding particle dispersion can be easily molded, and the productivity of the infrared ray shielding particle dispersion can be increased. In addition, the boride particles, which are infrared-shielding particles in the infrared-shielding particle dispersion liquid, are preferably dispersed with an average dispersed particle diameter of 100 nm or less, and more preferably 85 nm or less. If the average dispersed particle diameter of the infrared-shielding particles is 100 nm or less, the generation of blue haze in the infrared-shielding particle dispersion produced using the infrared-shielding particle dispersion liquid according to the present embodiment can be suppressed, and the optical properties can be improved. Further, when the average dispersed particle diameter is 85 nm or less, the generation of blue haze in the infrared-shielding particle dispersion can be particularly suppressed. (2) Infrared-shielding particle dispersion powder, infrared-shielding particle plasticizer dispersion liquid, masterbatch, and method for producing the same As described above, the boride particles, which are infrared-shielding particles, can be dispersed in a solvent together with a dispersant and a coupling agent and / or a surfactant as desired to obtain an infrared-shielding particle dispersion liquid. Then, by removing the solvent from the infrared-shielding particle dispersion liquid, the infrared-shielding particle dispersion powder according to the present embodiment in which the infrared-shielding particles are dispersed in, for example, a dispersant can be obtained. In this case, the infrared-shielding particle dispersion powder has the general formula XB ｍ (where X is one or more metal elements selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr, Ca, and m is a number indicating the amount of boron in the general formula), and can contain boride particles having a carbon content of 0.2 mass% or less when measured by the combustion-infrared absorption method and a dispersant. As a method for removing the solvent from the infrared-shielding particle dispersion liquid, it is preferable to subject the infrared-shielding particle dispersion liquid to drying under reduced pressure. Specifically, the infrared-shielding particle dispersion liquid is dried under reduced pressure while being stirred to separate the infrared-shielding particle-containing composition and the solvent component. Examples of the apparatus used for the drying under reduced pressure include a vacuum stirring type dryer, but any apparatus having the above functions may be used and is not particularly limited. Further, the pressure value during the reduced pressure in the drying step is appropriately selected. By using the reduced-pressure drying method, the removal efficiency of the solvent from the infrared-shielding particle dispersion liquid is improved, and the infrared-shielding particle dispersion powder according to the present embodiment is not exposed to high temperature for a long time. Therefore, aggregation of the infrared-shielding particles dispersed in the dispersion powder or the plasticizer dispersion liquid does not occur, which is preferable. Furthermore, the productivity of the infrared-shielding particle dispersion powder and the like is also increased, and it is easy to recover the evaporated solvent, which is also preferable from the perspective of environmental consideration. In the infrared-shielding particle dispersion powder according to the present embodiment obtained after the drying step, the residual organic solvent is preferably 5% by mass or less. If the residual organic solvent is 5% by mass or less, no bubbles will be generated when the infrared-shielding particle dispersion powder is processed into an infrared-shielding combined transparent base material or the like, and the appearance and optical properties will be kept good. In addition, the infrared-shielding particles can be dispersed in a plasticizer together with a dispersant, a coupling agent and / or a surfactant to obtain an infrared-shielding particle plasticizer dispersion liquid. Note that the infrared-shielding particle plasticizer dispersion liquid is not limited to the above method, and can also be obtained by adding a plasticizer to the infrared-shielding particle dispersion liquid and removing the solvent. Regarding the removal of the solvent, it is preferably performed by reduced-pressure drying in the same manner as in the process of producing the infrared-shielding particle dispersion powder. As the infrared-shielding particle plasticizer dispersion liquid, the general formula XB ｍ (where X is one or more metal elements selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr, Ca, and m is a number indicating the amount of boron in the composition formula), and can contain boride particles having a carbon content of 0.2% by mass or less when measured by the combustion-infrared absorption method and a plasticizer. In addition, by dispersing the boride particles or the dispersion powder in a resin and pelletizing the resin, the masterbatch according to the present embodiment can be obtained. In addition, after uniformly mixing the boride particles or the infrared-shielding particle dispersion powder, the powder or pellets of the thermoplastic resin, and other additives as necessary, kneading with a vent-type single-screw or twin-screw extruder, and cutting the once-melt-extruded strand into a pellet shape, the masterbatch can also be obtained. The shape of the masterbatch is not particularly limited, and examples thereof include columnar and prismatic shapes. It is also possible to employ a so-called hot cut method in which the melt extrudate is directly cut. In this case, it generally has a shape close to spherical. Incidentally, the masterbatch of the present embodiment has the general formula XB ｍ (wherein X is one or more metal elements selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr, Ca, and m is a number indicating the amount of boron in the general formula), and is an infrared-shielding particle dispersion containing boride particles having a carbon content of 0.2 mass% or less when measured by a combustion-infrared absorption method, and a thermoplastic resin, and can have a pellet shape. (3) Method for producing infrared-shielding particle dispersion By uniformly mixing the infrared-shielding particle dispersion powder, the infrared-shielding particle plasticizer dispersion liquid, or the masterbatch of the present embodiment described so far into a thermoplastic resin which is a transparent resin, the infrared-shielding particle dispersion according to the present embodiment can be produced. According to the infrared-shielding particle dispersion of the present embodiment, for example, while ensuring the infrared-shielding characteristics of the composite tungsten oxide according to the prior art, the transmittance of near-infrared light in the region of 700 nm or more and 1200 nm or less can be improved. Since the thermoplastic resin that can be suitably used for the infrared-shielding particle dispersion of the present embodiment has been described above, the description thereof is omitted here. Then, after kneading the dispersion powder or the plasticizer dispersion liquid or the masterbatch, the thermoplastic resin, and, if desired, a plasticizer and other additives, the kneaded product is formed into, for example, a planar or curved sheet material by a known method such as an extrusion molding method or an injection molding method, whereby an infrared-shielding particle dispersion can be produced. Known methods can be used for the method of forming the infrared-shielding particle dispersion. For example, a calendar roll method, an extrusion method, a casting method, an inflation method, etc. can be used. (Infrared-shielding combined transparent substrate) The infrared-shielding laminated transparent substrate of the present embodiment can have a plurality of transparent substrates and the above-described infrared-shielding particle dispersion. And the infrared-shielding particle dispersion can have a configuration disposed between a plurality of transparent substrates. The infrared-shielding laminated transparent substrate is a structure in which the infrared-shielding particle dispersion as an intermediate layer is sandwiched between transparent substrates from both sides thereof. As the transparent substrate, plate glass, plate-shaped plastic, film-shaped plastic, etc. that are transparent in the visible light region are used. That is, a transparent glass substrate or a transparent plastic substrate can be used. The material of the plastic is not particularly limited and can be selected according to the application. For example, when used in transportation equipment such as automobiles, from the viewpoint of ensuring the visibility of the driver and passengers of the transportation equipment, transparent resins such as polycarbonate resin, acrylic resin, and polyethylene terephthalate resin are preferable. In addition, polyamide resin, vinyl chloride resin, olefin resin, epoxy resin, polyimide resin, fluororesin, etc. can also be used. In addition, when the visible light (wavelength 400 nm or more and 780 nm or less) transmittance of the infrared-shielding particle dispersion contained in the infrared-shielding laminated transparent substrate of the present embodiment is set to be 45% or more and 55% or less, it is preferable that the maximum value of the diffusion transmittance profile in the region of 360 nm or more and 500 nm or less is 1.5% or less. This is because when the maximum value of the diffusion transmittance profile is within the above range, blue haze can be more reliably suppressed. The infrared-shielding laminated transparent substrate according to the present embodiment can also be obtained by bonding and integrating a plurality of opposing inorganic glasses sandwiching the above-described infrared-shielding particle dispersion together by a known method. The obtained infrared-shielding laminated inorganic glass can be preferably used mainly as the inorganic glass for the front of an automobile or as the window of a building. Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples. First, the evaluation methods of the samples in the following examples and comparative examples will be described here. (Composition of boride particles) For the boride particles obtained in the following examples and comparative examples, analysis was performed using ICP (model: ICPE9000, manufactured by Shimadzu Corporation), and the elemental ratio (molar ratio) of boron (B) to the metal element X when represented by the general formula XB ｍ was calculated, that is, the value of m which is the elemental ratio (B / X) of boron (B) and the metal element X in the boride particles. (Carbon concentration in boride particles) The carbon content (carbon concentration) in the boride particles prepared in the following examples and comparative examples was measured by combustion-infrared absorption method. (B ４ C concentration in boride particles) Of the obtained boride particles, two samples for measuring the B ４ C concentration were divided, weighed into a platinum crucible respectively, 7N nitric acid was added, and heated to 50 °C to dissolve the boride particles. After cooling, pure water was added, and then the undissolved residue (B ４ C) was separated by filtration using a cellulose acetate membrane filter with a pore size of 0.2 μm. One of the obtained undissolved residues was put into the original platinum crucible, moistened with a saturated aqueous solution of calcium hydroxide to prevent boron volatilization, and then dried in a dryer at about 80 °C. After drying, sodium carbonate was added and thoroughly mixed, and then heated and melted. After cooling, the molten salt in the crucible was dissolved in warm water and transferred to a Teflon (registered trademark) beaker. After adding nitric acid, it was heated to boiling to remove carbon dioxide gas, and then used as a sample solution for ICP. The boron concentration in the obtained sample solution was analyzed by ICP. In addition, XRD measurement was performed on the other obtained undissolved residue to confirm whether the undissolved residue was a single phase of B ４ C. When it was a single phase of B ４ C, the B ４ C concentration was calculated from the boron concentration analyzed by ICP. (Average dispersed particle size) The average dispersed particle diameter of the boride particles in the infrared ray-shielding particle dispersion liquid (boride particle dispersion liquid) prepared in the following Examples and Comparative Examples was measured by a particle size measuring device (Model: ELS-8000, manufactured by Otsuka Electronics Co., Ltd.) based on the dynamic light scattering method. The refractive index of the particles was set to 1.81, and the particle shape was non-spherical. The background was measured with toluene, and the refractive index of the solvent was set to 1.50. (Weight concentration ratio of Zr to metal element X in the boride particle dispersion liquid (Zr / X)) The weight concentration ratio of Zr to metal element X in the boride particle dispersion liquid (Zr / X) was measured by ICP (Model: ICPE9000, manufactured by Shimadzu Corporation) and calculated from the measured values. (Visible light transmittance) The visible light transmittance in the following Examples and Comparative Examples is the ratio of the transmitted light beam to the incident light beam for the daylight beam perpendicularly incident on the sample. Here, the above-mentioned daylight means the CIE daylight defined by the International Commission on Illumination. In this CIE daylight, the spectral irradiance distribution of daylight with the same color temperature as the color temperature of blackbody radiation is shown as a relative value with respect to the value at a wavelength of 560 nm based on the observed data. Also, the above-mentioned light beam is the integrated value of the product of the spectral radiant flux for each wavelength of the radiation and the value of the luminous sensitivity (sensitivity of the human eye to light) with respect to the wavelength. That is, the visible light transmittance is a value that means the brightness felt by the human eye, which is the integrated value of the transmitted light amount normalized by the luminous sensitivity of the human eye for the light transmission amount in the region of wavelengths of 380 nm or more and 780 nm or less. For the visible light transmittance measurement, using a spectrophotometer (Model: U-4100, manufactured by Hitachi, Ltd.), the infrared ray-shielding particle dispersion or the infrared ray-shielding combined transparent base material prepared in the following Examples and Comparative Examples was measured at intervals of 1 nm in the range of wavelengths from 300 nm to 2600 nm. (Maximum value of the diffuse transmittance profile) For the boride particle dispersion liquid prepared in the following Examples and Comparative Examples, the visible light (wavelength from 400 nm to 780 nm) transmittance was adjusted to 50%. Using a spectrophotometer (Model: U-4100, manufactured by Hitachi, Ltd.) as the spectroscope, the maximum value of the diffuse transmittance profile in the region of wavelengths from 360 nm to 500 nm was measured by the method described with reference to FIGS. 1 and 2. The measurement sample was prepared by diluting the boride particle dispersion prepared in each example and comparative example with the main solvent so as to have the above-described visible light transmittance, placing it in a 10 mm square glass cell, and used for measurement. When the maximum value of the measured diffusion transmission profile is 1.5% or less, it has been confirmed that almost no blue haze is observed in the infrared shielding particle dispersion prepared using the boride particle dispersion. In the measurement, the visible light transmittance of the boride particle dispersion is set to 50% or less in order to specify the measurement conditions of the diffusion transmittance (diffusion transmission profile), and the range is set because the diffusion transmittance is proportional to the visible light transmittance. Further, the diffusion transmittance (diffusion transmission profile) in the region of 360 nm or more and 500 nm or less in wavelength is measured because scattering in that region is exactly the cause of blue haze. Also, for the infrared shielding transparent substrate, infrared shielding particle dispersion, or infrared shielding combined transparent substrate prepared in the following examples and comparative examples, as a spectroscope, a spectrophotometer (manufactured by Hitachi, Ltd., model: U-4100) was used, and the diffusion transmittance was measured at intervals of 1 nm in the range of 300 nm or more and 800 nm or less in wavelength by the method described with reference to FIGS. 1 and 2. Then, the maximum value was obtained from the obtained diffusion transmission profile. In addition, when evaluating the maximum value of the diffusion transmission profile of the infrared shielding particle dispersion and the infrared shielding combined transparent substrate, in each example and comparative example, except that the thickness of the infrared shielding particle dispersion was adjusted so that the visible light transmittance was 50%, the infrared shielding particle dispersion and the infrared shielding combined transparent substrate for measuring the diffusion transmission profile were prepared under the same conditions as in each example and comparative example, and the evaluation was performed. (Haze) The haze value of the infrared shielding transparent substrate, infrared shielding particle dispersion, or infrared shielding combined transparent substrate prepared in the following examples and comparative examples was measured using a haze meter (manufactured by Murakami Color Research Laboratory, model: HM-150) based on JIS K 7105-1981. (Blue Haze) Blue haze was visually confirmed by irradiating the infrared-shielding transparent base material, the infrared-shielding particle dispersion, or the infrared-shielding laminated transparent base material produced in the following examples and comparative examples with an artificial sunlight lamp [XC-100 manufactured by Celic Corporation]. The production conditions and evaluation results of the samples in each example and comparative example will be described below. [Example 1] Using boron carbide as a boron source and a reducing agent, and lanthanum oxide as a lanthanum source, these were weighed and mixed so that the element ratio of B / La, which is the element ratio of lanthanum to boron, was 5.90. Then, it was fired at a temperature of 1600 ± 50 °C for 6 hours in an argon atmosphere to obtain a powder containing lanthanum hexaboride particles. When the carbon concentration of the obtained powder containing lanthanum hexaboride particles was measured by combustion-infrared absorption method, the carbon content was 0.05% by mass. Also, when the composition of the obtained lanthanum hexaboride particles was evaluated by ICP, it was confirmed that m, which is the element ratio (B / La) of boron (B) to lanthanum element (La) in the general formula LaB ｍ was 5.8. Furthermore, regarding the obtained powder containing lanthanum hexaboride particles, the B ４ C concentration of the powder containing lanthanum hexaboride particles was measured by the evaluation method of the B ４ C concentration in the boride particles described above, and it was 0.2% by mass. Next, 10 parts by weight of the produced powder containing lanthanum hexaboride particles (infrared-shielding material), 80 parts by weight of toluene, and 10 parts by weight of a dispersant (acrylic polymer dispersant having an amino group) were weighed and mixed to prepare 3 kg of a slurry. This slurry was put into a media agitation mill together with beads, and the slurry was circulated to perform a pulverization and dispersion treatment for 20 hours. The media agitation mill used was a horizontal cylindrical annular type (manufactured by Ashizawa Co., Ltd.), and the materials of the vessel inner wall and the rotor (rotating agitation part) were ZrO ２It was set as such. Also, as the beads, beads made of YSZ (Yttria-Stabilized Zirconia: yttria-stabilized zirconia) with a diameter of 0.3 mm were used. The rotational speed of the rotor was set to 13 m / sec, and pulverization was performed at a slurry flow rate of 1 kg / min. When the average dispersed particle diameter of the boride particles in the obtained boride particle dispersion liquid was measured, it was 70 nm. Furthermore, regarding the dispersion liquid, as described above, the weight concentration ratio (Zr / La) of Zr and La in the boride particle dispersion liquid and the evaluation of the maximum value of the diffusion transmission profile were performed. The results are shown in Table 1. Also, the obtained dispersion liquid, ultraviolet curable resin, and toluene were mixed at a weight ratio of dispersion liquid:ultraviolet curable resin:toluene = 2:1:1 to prepare a coating liquid. This was applied onto a transparent glass substrate with a bar coater to form a coating film. At this time, the bar used for coating was selected so that the visible light transmittance of the obtained coating layer would be about 50%. Note that as the bar coater, IMC-700 manufactured by Imoto Seisakusho was used, and the thickness of the obtained coating layer was about 10 μm. Next, after evaporating the solvent from this coating film by holding it at 70°C for 1 minute, ultraviolet irradiation was performed to cure the coating film. Then, the optical properties of the obtained infrared-shielding transparent substrate were measured. The measurement results are shown in Table 1 below. The haze of the obtained infrared-shielding transparent substrate was 0.2%, and it was confirmed that the transparency was extremely high. Also, the maximum value of the diffusion transmission profile in the region of wavelengths from 360 nm to 500 nm was 0.6%, and no blue haze was observed when irradiated with sunlight. Furthermore, the same amount of a dispersant (an acrylic polymer dispersant having an amino group) was added to the obtained dispersion liquid, and after holding the obtained mixed liquid in a dryer to remove the solvent component and then pulverizing it, an infrared-shielding particle dispersion powder was obtained. The obtained infrared-shielding particle dispersion powder was mixed with a polycarbonate resin, and a pellet-shaped masterbatch was prepared using an extrusion processor. Furthermore, the above masterbatch and the polycarbonate resin were mixed, and an infrared ray shielding particle dispersion was formed by an extrusion processor. At this time, the mixing ratio of the polycarbonate resin and the masterbatch was adjusted so that the visible light transmittance of the obtained infrared ray shielding particle dispersion was about 70%. The measurement results of the optical properties of the obtained infrared ray shielding particle dispersion are shown in Table 1 below. It was confirmed that the visible light transmittance was about 70% and the light in the visible light region was sufficiently transmitted. Furthermore, the haze was 0.3%, and it was confirmed that the transparency was extremely high. Also, the maximum value of the diffuse transmittance profile in the wavelength range of 360 nm to 500 nm was 0.8%, and blue haze (coloring) was not observed when irradiated with simulated sunlight. In addition, when evaluating the maximum value of the diffuse transmittance profile of the infrared ray shielding particle dispersion or the infrared ray shielding combined transparent substrate, the infrared ray shielding particle dispersion or the infrared ray shielding combined transparent substrate for measuring the diffuse transmittance profile described above is produced and evaluated. The same applies to the following other examples and comparative examples. [Example 2] A powder containing lanthanum hexaboride particles was obtained in the same manner as in Example 1, except that boron carbide and lanthanum oxide were weighed and mixed so that the element ratio B / La of lanthanum and boron was 5.95. When the carbon concentration of the obtained powder containing lanthanum hexaboride particles was measured by combustion-infrared absorption method, the carbon content was 0.1% by mass. In addition, when the composition of the obtained lanthanum hexaboride particles was evaluated by ICP, it was confirmed that m, which is the element ratio (B / La) of boron (B) to lanthanum element (La) in the general formula LaB ｍ was 5.9. Furthermore, regarding the obtained powder containing lanthanum hexaboride particles, the B ４ C concentration of the powder containing lanthanum hexaboride particles was measured by the evaluation method of the B ４ C concentration in the boride particles described above, and it was 0.5% by mass. Then, except for using the lanthanum hexaboride particle-containing powder, a boride particle dispersion was prepared in the same manner as in Example 1. Further, using the obtained dispersion, an infrared-shielding transparent substrate, an infrared-shielding particle dispersion powder, a masterbatch, and further an infrared-shielding particle dispersion were produced in the same manner as in the case of Example 1. The obtained dispersion, the infrared-shielding transparent substrate, and the infrared-shielding particle dispersion were evaluated in the same manner as in Example 1. The results are shown in Table 1. [Example 3] Except for weighing and mixing boron carbide and lanthanum oxide so that the element ratio B / La of lanthanum and boron was 6.00, lanthanum hexaboride particle-containing powder was obtained in the same manner as in Example 1. When the carbon concentration of the obtained lanthanum hexaboride particle-containing powder was measured by combustion-infrared absorption method, the carbon content was 0.2 mass%. Further, when the composition of the obtained lanthanum hexaboride particles was evaluated by ICP, it was confirmed that m, which is the element ratio (B / La) of boron (B) to lanthanum element (La) in the general formula LaB ｍ was 5.9. Furthermore, for the obtained lanthanum hexaboride particle-containing powder, the B ４ C concentration of the lanthanum hexaboride particle-containing powder was measured by the evaluation method of the B ４ C concentration in the boride particles described above, and it was 0.9 mass%. Then, except for using the lanthanum hexaboride particle-containing powder, a boride particle dispersion was prepared in the same manner as in Example 1. Further, using the obtained dispersion, an infrared-shielding transparent substrate, an infrared-shielding particle dispersion powder, a masterbatch, and further an infrared-shielding particle dispersion were produced in the same manner as in the case of Example 1. The obtained dispersion, the infrared-shielding transparent substrate, and the infrared-shielding particle dispersion were evaluated in the same manner as in Example 1. The results are shown in Table 1. [Example 4] Except for weighing and mixing boron carbide and lanthanum oxide so that the element ratio B / La of lanthanum and boron was 6.10, lanthanum hexaboride particle-containing powder was obtained in the same manner as in Example 1. When the carbon concentration of the obtained lanthanum hexaboride particle-containing powder was measured by combustion-infrared absorption method, the carbon content was 0.2% by mass. Further, when the composition of the obtained lanthanum hexaboride particles was evaluated by ICP, it was confirmed that m, which is the element ratio (B / La) of boron (B) to lanthanum element (La) in the general formula LaB ｍ was 6.0. Furthermore, for the obtained lanthanum hexaboride particle-containing powder, the BC concentration of the lanthanum hexaboride particle-containing powder was measured by the evaluation method of the BC concentration in the boride particles described above, and it was 0.9% by mass. ４ ４ Then, except for using such lanthanum hexaboride particle-containing powder, a boride particle dispersion was prepared in the same manner as in Example 1. Further, using the obtained dispersion, an infrared-shielding transparent substrate, an infrared-shielding particle dispersion powder, a masterbatch, and further an infrared-shielding particle dispersion were produced in the same manner as in the case of Example 1. The obtained dispersion, the infrared-shielding transparent substrate, and the infrared-shielding particle dispersion were evaluated in the same manner as in Example 1. The results are shown in Table 1. [Example 5] Lanthanum hexaboride particle-containing powder was obtained in the same manner as in Example 1, except that boron carbide and lanthanum oxide were weighed and mixed so that the element ratio B / La of lanthanum and boron was 6.20, and fired under the temperature condition of 1650 ± 50°C. When the carbon concentration of the obtained lanthanum hexaboride particle-containing powder was measured by combustion-infrared absorption method, the carbon content was 0.2% by mass. Further, when the composition of the obtained lanthanum hexaboride particles was evaluated by ICP, it was confirmed that m, which is the element ratio (B / La) of boron (B) to lanthanum element (La) in the general formula LaB ｍ was 6.0. Furthermore, for the obtained lanthanum hexaboride particle-containing powder, the BC concentration of the lanthanum hexaboride particle-containing powder was measured by the evaluation method of the BC concentration in the boride particles described above, and it was 0.9% by mass. ４ ４ ​​​​Then, except for using the powder containing lanthanum hexaboride particles, a boride particle dispersion was prepared in the same manner as in Example 1. Further, using the obtained dispersion, an infrared-shielding transparent substrate, an infrared-shielding particle dispersion powder, a masterbatch, and further an infrared-shielding particle dispersion were produced in the same manner as in the case of Example 1. The obtained dispersion, the infrared-shielding transparent substrate, and the infrared-shielding particle dispersion were evaluated in the same manner as in Example 1. The results are shown in Table 1. [Example 6] Using boron oxide as a boron source, lanthanum oxide as a lanthanum source, and carbon (graphite) as a reducing agent, lanthanum hexaboride particle-containing powder was obtained in the same manner as in Example 1, except that weighing and mixing were performed so that the elemental ratio B / La of lanthanum and boron was 6.10. However, 60 parts by weight of carbon was weighed and mixed with respect to 100 parts by weight of boron oxide. When the carbon concentration of the obtained lanthanum hexaboride particle-containing powder was measured by combustion-infrared absorption method, the carbon content was 0.1% by mass. Further, when the composition of the obtained lanthanum hexaboride particles was evaluated by ICP, it was confirmed that m, which is the elemental ratio (B / La) of boron (B) to lanthanum element (La) in the general formula LaB ｍ was 6.0. Furthermore, for the obtained lanthanum hexaboride particle-containing powder, the B ４ C concentration of the lanthanum hexaboride particle-containing powder was measured by the evaluation method of the B ４ C concentration in the boride particles described above, and it was 0.4% by mass. Then, except for using the lanthanum hexaboride particle-containing powder, a boride particle dispersion was prepared in the same manner as in Example 1. Further, using the obtained dispersion, an infrared-shielding transparent substrate, an infrared-shielding particle dispersion powder, a masterbatch, and further an infrared-shielding particle dispersion were produced in the same manner as in the case of Example 1. The obtained dispersion, the infrared-shielding transparent substrate, and the infrared-shielding particle dispersion were evaluated in the same manner as in Example 1. The results are shown in Table 1. [Example 7] Except that cerium oxide was used instead of lanthanum oxide so that the elemental ratio B / Ce of cerium and boron was 6.10, cerium hexaboride particle-containing powder was obtained in the same manner as in Example 1. When the carbon concentration of the obtained cerium hexaboride particle-containing powder was measured by combustion-infrared absorption method, the carbon content was 0.2% by mass. Further, when the composition of the obtained cerium hexaboride particles was evaluated by ICP, m which is the elemental ratio (B / Ce) of boron (B) to cerium element (Ce) in the general formula CeB ｍ was confirmed to be 6.0. Furthermore, regarding the obtained cerium hexaboride particle-containing powder, the B ４ C concentration of the boride particles was measured by the evaluation method described above, and the B ４ C concentration of the cerium hexaboride particle-containing powder was 0.9% by mass. Then, except for using such cerium hexaboride particle-containing powder, a boride particle dispersion was prepared in the same manner as in Example 1. Further, using the obtained dispersion, an infrared-shielding transparent substrate, an infrared-shielding particle dispersion powder, a masterbatch, and further an infrared-shielding particle dispersion were produced in the same manner as in the case of Example 1. The obtained dispersion, the infrared-shielding transparent substrate, and the infrared-shielding particle dispersion were evaluated in the same manner as in Example 1. The results are shown in Table 1. [Example 8] A dispersant (fatty acid amine-based dispersant) and a plasticizer were added to the infrared-shielding particle dispersion (boride particle dispersion) prepared in Example 1 at a weight ratio of 4:1:10, and the solvent component was removed in a vacuum dryer to obtain an infrared-shielding particle plasticizer dispersion. The obtained infrared-shielding particle plasticizer dispersion and polyvinyl butyral resin were mixed, and an infrared-shielding particle dispersion in sheet form was obtained by an extrusion processor. At this time, the mixing ratio was adjusted so that the visible light transmittance of the finally obtained infrared-shielding combined transparent substrate was about 70%. The obtained sheet-shaped infrared-shielding particle dispersion was sandwiched between two glass substrates (thickness: 3 mm), and an infrared-shielding laminated transparent substrate in the form of laminated glass was produced using a hot press machine. The obtained infrared-shielding laminated transparent substrate was evaluated in the same manner as in the case of the infrared-shielding particle dispersion of Example 1. The results are shown in Table 1. [Comparative Example 1] Boron carbide was used as a boron source and a reducing agent, and lanthanum oxide was used as a lanthanum source. These were weighed and mixed so that the elemental ratio B / La of lanthanum and boron was 6.10. Then, it was fired at a temperature of 1480 ± 50 °C for 6 hours in an argon atmosphere to obtain a powder containing lanthanum hexaboride particles. When the carbon concentration of the obtained powder containing lanthanum hexaboride particles was measured by combustion-infrared absorption method, the carbon content was 0.6% by mass. Further, when the composition of the obtained lanthanum hexaboride particles was evaluated by ICP, it was confirmed that m, which is the elemental ratio (B / La) of boron (B) to lanthanum element (La) in the general formula LaB ｍ was 6.0. Furthermore, for the obtained powder containing lanthanum hexaboride particles, the B ４ C concentration of the powder containing lanthanum hexaboride particles was measured by the evaluation method of B ４ C concentration in the boride particles described above, and it was 2.6% by mass. Then, a boride particle dispersion was prepared in the same manner as in Example 1 except that the powder containing lanthanum hexaboride particles was used. The obtained dispersion was evaluated in the same manner as in Example 1. The results are shown in Table 2. In addition, in order to prepare the dispersion, when the pulverization treatment was carried out for 20 hours, the average dispersed particle diameter was 105 nm, which was larger than 100 nm. However, since the pulverization efficiency was significantly reduced due to the increase in the slurry viscosity, it was judged that it was difficult to obtain a particle diameter of 100 nm or less even if the pulverization treatment was continued. Also, Zr / La in the obtained boride particle dispersion was 1.8, which was higher than that in the cases of Examples 1 to 8, indicating that a large amount of media beads were worn and mixed into the slurry. Furthermore, the peak value of the diffusion transmittance is 1.8%, which is higher than that in Examples 1 to 8. When an optical member is produced using this, there is concern that strong blue haze will be observed. Using the obtained dispersion liquid, a coating layer was formed on a transparent glass substrate in the same manner as in Example 1 to obtain an infrared-shielding transparent substrate. Then, the optical properties of the obtained infrared-shielding transparent substrate were measured. The measurement results are shown in Table 2 below. The haze of the obtained infrared-shielding transparent substrate was 1.6%, confirming that the transparency was extremely low. Also, the maximum value of the diffusion transmittance profile in the region of wavelengths of 360 nm or more and 500 nm or less was 1.9%, and blue haze was clearly confirmed visually when irradiated with simulated sunlight. Furthermore, the same amount of a dispersant (an acrylic polymer dispersant having an amino group) was added to the obtained dispersion liquid, and after the obtained mixture was held in a dryer to remove the solvent component and then pulverized, an infrared-shielding particle dispersion powder was obtained. The obtained infrared-shielding particle dispersion powder was mixed with a polycarbonate resin, and a pellet-shaped masterbatch was produced using an extrusion processor. Furthermore, the above masterbatch and polycarbonate resin were mixed, and an infrared-shielding particle dispersion was formed by an extrusion processor. At this time, the mixing ratio of the polycarbonate resin and the masterbatch was adjusted so that the visible light transmittance of the obtained infrared-shielding particle dispersion would be about 70%. The optical property measurement results of the obtained infrared-shielding particle dispersion are shown in Table 2 below. The visible light transmittance was about 70%, confirming that light in the visible light region was sufficiently transmitted. However, the haze was 1.6%, confirming that the transparency was extremely low. Also, the maximum value of the diffusion transmittance profile in the region of wavelengths of 360 nm or more and 500 nm or less was 2.0%, and blue haze was clearly confirmed visually when irradiated with simulated sunlight. [Comparative Example 2] A powder containing lanthanum hexaboride particles was obtained in the same manner as in Comparative Example 1, except that boron carbide and lanthanum oxide were weighed and mixed so that the element ratio B / La of lanthanum and boron was 6.20. When the carbon concentration of the obtained lanthanum hexaboride particle-containing powder was measured by combustion-infrared absorption method, the carbon content was 0.8% by mass. Further, when the composition of the obtained lanthanum hexaboride particles was evaluated by ICP, it was confirmed that m, which is the element ratio (B / La) of boron (B) to lanthanum element (La) in the general formula LaB ｍ is 6.1. Furthermore, for the obtained lanthanum hexaboride particle-containing powder, the B ４ C concentration of the lanthanum hexaboride particle-containing powder was measured by the evaluation method of the B ４ C concentration in the boride particles described above, and it was 3.7% by mass. Then, except for using such lanthanum hexaboride particle-containing powder, a boride particle dispersion was prepared in the same manner as in Example 1. Further, an infrared-shielding transparent substrate, an infrared-shielding particle dispersion powder, a masterbatch, and further an infrared-shielding particle dispersion were produced in the same manner as in the case of Example 1 using the obtained dispersion. The obtained dispersion, the infrared-shielding transparent substrate, and the infrared-shielding particle dispersion were evaluated in the same manner as in Example 1. The results are shown in Table 2. In addition, in order to prepare the dispersion, when the pulverization treatment was performed for 20 hours, the average dispersed particle diameter was 111 nm, which was larger than 100 nm. However, since the pulverization efficiency was significantly reduced due to the increase in the slurry viscosity, it was judged that it was difficult to obtain a particle diameter of 100 nm or less even if the pulverization treatment was continued. Also, Zr / La in the obtained boride particle dispersion was 2.0, which was higher than that in the cases of Examples 1 to 8, indicating that a large amount of media beads were worn and mixed into the slurry. Furthermore, the peak value of the diffusion transmittance was 2.4%, which was higher than that in the cases of Examples 1 to 8. When an optical member is produced using this, there is a concern that strong blue haze will be observed. Also, a coating layer was formed on a glass substrate in the same manner as in the case of Example 1 using the obtained dispersion. Then, the optical properties of the obtained infrared-shielding transparent substrate were measured. The measurement results are shown in Table 2 below. The haze of the obtained infrared-shielding transparent substrate was 1.8%, and it was confirmed that the transparency was very low. Also, the maximum value of the diffuse transmittance profile in the region of 360 nm or more and 500 nm or less in wavelength was 2.4%, and when irradiated with sunlight, a clear blue haze was visually confirmed as in the case of Comparative Example 1. [Comparative Example 3] Using boron oxide as the boron source, lanthanum oxide as the lanthanum source, and carbon (graphite) as the reducing agent, a powder containing lanthanum hexaboride particles was obtained in the same manner as in Comparative Example 1, except that the elemental ratio B / La of lanthanum and boron was weighed and mixed to be 6.10. However, 60 parts by weight of carbon was weighed and mixed with respect to 100 parts by weight of boron oxide. When the carbon concentration of the obtained powder containing lanthanum hexaboride particles was measured by combustion-infrared absorption method, the carbon content was 0.7 mass%. Also, when the composition of the obtained lanthanum hexaboride particles was evaluated by ICP, it was confirmed that m, which is the elemental ratio (B / La) of boron (B) to lanthanum element (La) in the general formula LaB ｍ was 6.0. Furthermore, for the obtained powder containing lanthanum hexaboride particles, the B ４ C concentration of the powder containing lanthanum hexaboride particles was measured by the evaluation method of the B ４ C concentration in the boride particles described above, and it was 3.4 mass%. Then, a boride particle dispersion was prepared in the same manner as in Example 1, except that the powder containing lanthanum hexaboride particles was used. Also, using the obtained dispersion, an infrared-shielding transparent substrate, an infrared-shielding particle dispersion powder, a masterbatch, and further an infrared-shielding particle dispersion were produced in the same manner as in the case of Example 1. The obtained dispersion, the infrared-shielding transparent substrate, and the infrared-shielding particle dispersion were evaluated in the same manner as in Example 1. The results are shown in Table 2. The haze of the obtained infrared-shielding transparent substrate was 1.7%, and it was confirmed that the transparency was extremely low. Also, the maximum value of the diffuse transmittance profile in the region of wavelengths of 360 nm or more and 500 nm or less was 2.2%. Further, when irradiated with sunlight, a clear blue haze was visually confirmed in the same manner as in Comparative Example 1. [Comparative Example 4] A powder containing cerium hexaboride particles was obtained in the same manner as in Comparative Example 1, except that cerium oxide was used instead of lanthanum oxide so that the element ratio B / Ce of cerium and boron was 6.10. When the carbon concentration of the obtained powder containing cerium hexaboride particles was measured by the combustion-infrared absorption method, the carbon content was 0.9% by mass. Further, when the composition of the obtained cerium hexaboride particles was evaluated by ICP, it was confirmed that m, which is the element ratio (B / Ce) of boron (B) to cerium element (Ce) in the general formula CeB ｍ was 6.0. Furthermore, for the obtained powder containing cerium hexaboride particles, the B ４ C concentration of the powder containing cerium hexaboride particles was measured by the evaluation method of the B ４ C concentration in the boride particles described above, and it was 4.4% by mass. Then, a boride particle dispersion was prepared in the same manner as in Example 1, except that the powder containing cerium hexaboride particles was used. Further, using the obtained dispersion, an infrared-shielding transparent substrate, an infrared-shielding particle dispersion powder, a masterbatch, and further an infrared-shielding particle dispersion were produced in the same manner as in Example 1. The obtained dispersion, and the infrared-shielding transparent substrate and the infrared-shielding particle dispersion were evaluated in the same manner as in Example 1. The results are shown in Table 2. The haze of the obtained infrared-shielding transparent substrate was 1.9%, and it was confirmed that the transparency was extremely low. Also, the maximum value of the diffuse transmittance profile in the region of wavelengths of 360 nm or more and 500 nm or less was 2.5%. Further, when irradiated with sunlight, a clear blue haze was visually confirmed in the same manner as in Comparative Example 1. In Examples 1 to 8, it was confirmed that the boride particles obtained by solid-phase reaction or the like can be pulverized and refined relatively easily and economically to have an average dispersed particle diameter of 100 nm or less, particularly 85 nm or less. Further, in Examples 1 to 8, since the obtained boride particles have an average dispersed particle diameter of 100 nm or less, particularly 85 nm or less, the infrared shielding film produced using the particles or the dispersion liquid, the infrared shielding transparent substrate provided with a coating layer, and the infrared shielding particle dispersion do not turn bluish-white even when irradiated with simulated sunlight. That is, it was confirmed that blue haze is suppressed. Therefore, it was confirmed that the infrared shielding film, the infrared shielding transparent substrate, the infrared shielding optical member having the infrared shielding transparent substrate, the infrared shielding particle dispersion, the infrared shielding laminated transparent substrate, etc. produced using the boride particle dispersion liquids of Examples 1 to 8 are suitably used for window glass for building materials, window glass for vehicles, etc. In Examples 1 to 7, the thickness of the coating layer is about 10 μm and is 20 μm or less in all cases. On the other hand, in Comparative Examples 1 to 4 using a boride particle-containing powder having a carbon concentration higher than 0.2% by mass as a raw material, the average dispersed particle diameter was larger than 100 nm after 20 hours of pulverization treatment, and it was confirmed that it is difficult to obtain a particle diameter of 100 nm or less even if further pulverization is carried out due to an increase in viscosity. Furthermore, the maximum value of the diffusion transmission profile of the boride particle dispersion liquid is also higher than 1.5%. For this reason, it was confirmed that the occurrence of blue haze is a concern for the infrared shielding transparent substrate etc. produced using such a boride particle dispersion liquid. Also, there were problems when applying it to window glass for building materials, window glass for vehicles, etc. The boride particles, the boride particle dispersion liquid, the infrared shielding transparent substrate, the infrared shielding optical member, the infrared shielding particle dispersion, the infrared shielding laminated transparent substrate, the infrared shielding particle dispersion powder, and the masterbatch have been described in the embodiments and examples etc., but the present invention is not limited to the above embodiments and examples etc. Various modifications and changes are possible within the scope of the gist of the present invention described in the claims. This application claims priority based on Japanese Patent Application No. 2016-000298 filed with the Japan Patent Office on January 4, 2016, Japanese Patent Application No. 2016-000300 filed with the Japan Patent Office on January 4, 2016, Japanese Patent Application No. 2016-000301 filed with the Japan Patent Office on January 4, 2016, Japanese Patent Application No. 2016-254433 filed with the Japan Patent Office on December 27, 2016, Japanese Patent Application No. 2016-254437 filed with the Japan Patent Office on December 27, 2016, and Japanese Patent Application No. 2016-254440 filed with the Japan Patent Office on December 27, 2016, and incorporates the entire contents of Japanese Patent Application No. 2016-000298, Japanese Patent Application No. 2016-000300, Japanese Patent Application No. 2016-000301, Japanese Patent Application No. 2016-254433, Japanese Patent Application No. 2016-254437, and Japanese Patent Application No. 2016-254440 into this international application.

Claims

Revised 28 / 09 / 2018. Claim 1. Boride particles represented by the general formula XBm (where X is at least one type of metallic element selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr, Ca and m is the number representing the amount of boron in the general formula) where the amount of carbon included in the boride particles is 0.2% by mass or less, measured by the infrared absorption combustion method. ---------- Page 1 of 5. Claim 1. Boride particles represented by the general formula XBm (where X is at least one type of metallic element selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr, Ca) The types of metallic components selected are:

1. Boride particles according to claim 1, where Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr, Ca, and m is the number representing the amount of boron in the general formula), where the amount of carbon included in the boride particles is 0.2% by mass or less as measured by the infrared absorption combustion method.

2. Boride particles according to claim 1, where m in the general formula XBm is 4.0 or greater and 6.2 or less.

3. Boride particles according to claim 1 or 2, where the boride particles include danthanum hexaboride particles. 4.

5. A liquid dispersed with boride particles consisting of: boride particles according to one of the claims 1 to 4; and a liquid medium.

6. A liquid dispersed with boride particles according to claim 5 where the liquid medium is at least one of the selected types from water, organic solvents, fats and oils, liquid resins, and plasticizers.

7. A liquid dispersed with boride particles.

7. Liquids dispersed with boride particles according to one of Requisitions 5 through 7 where the average dispersed particle diameter of boride particles is 85 nm or less as measured by the dynamic light scattering method.

8. Liquids dispersed with boride particles according to one of Requisitions 5 through 7 where the boride particle concentration is 0.01% by mass or greater and 30% by mass or less. Page 2 of 5.

9. Liquids dispersed with boride particles according to one of Requisitions 5 through 8 where the weight concentration of Zr is less than or equal to 1.5 times the weight concentration of the metallic component X10. The transparent base that blocks infrared light consists of: a coating layer on at least one side of the transparent base that blocks infrared light, where the coating layer includes infrared blocking particles and a binder, and the infrared blocking particles are boride particles represented by the general formula XBm (where X is at least one type of metallic component selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr). ,Ca, and m are numbers representing the amount of boron in the general formula) and the amount of carbon incorporated into the boride particles is 0.2% by mass or less as measured by the infrared absorption combustion method.

11. The transparent base that blocks infrared light according to claim 10 where m in the general formula XBm is 4.0 or greater and 6.2 or less.

12. The transparent base that blocks infrared light according to claim 10 or 11 where the amount of B4C incorporated into the boride particles is 1.0% by mass or less.13.A transparent base that blocks infrared light under any of the claims 10 to 12 where the average dispersed particle diameter of the boride particles is 1 nm or greater and 100 nm or less.

14. A transparent base that blocks infrared light under any of the claims 10 to 13 where the binder includes at least one of the selected types from ultraviolet-cured resins, thermoplastic resins, thermosetting resins and room-temperature curing resins.

15. A transparent base that blocks light. Infrared as per any of the claims 10 to 14, where the coating layer thickness is 20 (formula) or less, page 3 of number 5, page 16. The transparent base that blocks infrared light as per any of the claims 10 to 15, where the peak intensity of the transmitted scattering profile is 1.5% or less in the wavelength range of 360 nm or more and 500 nm or less, where the visible light transmittance of the coating layer is set in the range of 45% or more and 55% or less.17.

18. An infrared-blocking optical member composed of an infrared-blocking transparent base particle according to one of the claims 10 through 16, where the infrared-blocking transparent base particle is a transparent film base particle or a transparent glass base particle.

19. An infrared-blocking optical member composed of an infrared-blocking transparent base particle according to one of the claims 10 through 17.

20. A body dispersed with infrared-blocking particles composed of: boride particles represented by the general formula XBm(where X is at least 16). A selection of metallic components (Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr, Ca, and m being the number representing the amount of boron in the general formula) where the amount of carbon incorporated into the boride particles is 0.2% by mass or less as measured by the infrared absorption combustion method; and a thermoplastic resin body dispersed with infrared-blocking particles according to claim 19 where m in the general formula XBm is 4.0 or greater and 6.2 or less.21.

21. A body dispersed with infrared-excitation particles under one of the claims 19 to 21 where the amount of B4C incorporated into the boride particles is 1.0% by mass or less. (Page 4 of 5, page 2) 22. A body dispersed with infrared-excitation particles under one of the claims 19 to 22 where the thermoplastic resin is... At least one type of resin selected from a group of resins including polyethylene terephthalate resin, polycarbonate resin, acrylic resin, styrene resin, polyamide resin, polyethylene resin, vinyl chloride resin, olefin resin, epoxy resin, polyimide resin, fluororesin, ethylene-vinyl acetate copolymer, ionomer resin, polyvinyl butyryl resin and polyvinyl acetal resin, a mixture of two or more resins selected from the resin group, and a copolymer including two or more resins selected from the resin group.2425. A body dispersed with infrared-excitation particles according to one of the claims 19 to 23 where the body dispersed with infrared-excitation particles is in sheet, board or film form.

26. A body dispersed with infrared-excitation particles according to one of the claims 19 to 25 where the boride particle content per irradiated unit area is 0.01 g / m² or greater and 1.0 g / m² or less.

27. A body dispersed with infrared-excitation particles according to one of the claims 19 to 25 where the peak intensity of the transmitted scattering profile is 1.5% or less in the wavelength range of 360 nm or greater and 500 nm or less in the case where the visible light transmittance is set to 45% or greater and 55% or less.The transparent base portion laminated with infrared-blocking particles consists of: a large quantity of the transparent base portion; and a body dispersed with infrared-blocking particles according to one of the claims 19 to 26, where page 5 of 5 pages of the body dispersed with infrared-blocking particles is arranged between the large quantity of the transparent base portion.

28. The powder dispersed with infrared-blocking particles consists of: boride particles represented by the general formula XBm (where X is at least one type of metallic component selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr, Ca, and m is the number representing the amount of boron in the general formula), where the amount of carbon incorporated into the boride particles is 0.2% by mass or less as measured by the infrared absorption combustion method; and the dispersant.29.The masterbatch consists of a body dispersed with infrared-blocking particles including: boride particles represented by the general formula XBm (where X is at least one type of metallic component selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr, Ca, and m is the number representing the amount of boron in the general formula) where the amount of carbon incorporated into the boride particles is 0.2% by mass or less as measured by the infrared absorption combustion method; and thermoplastic resin, in which the masterbatch has a spherical shape.