JP2012256041A - Heat-ray shielding material, lamination structure and laminated glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-ray shielding material capable of realizing high optical transparency in a visible light region while increasing reflectance of infrared rays over a wide band, and lamination structure and laminated glass which use the heat-ray shielding material.SOLUTION: A heat-ray shielding material includes a metal particle containing layer containing at least a kind of metal particle and an infrared ray reflecting layer where at least two kinds of transparent thin layers with different refractive indexes are alternately laminated in 5-200 layers. The metal particle is a tabular metal particle which has a hexagonal or circular shape, and the heat-ray shielding material has equal to or more than 60% by number of the flat plate-shaped metal particles.

Description

  The present invention relates to a heat ray shielding material, a laminated structure using such a heat ray shielding material, and laminated glass, which achieve high light transmittance in the visible light region while improving infrared reflectance over a wide band.

  In recent years, heat ray shielding materials for automobiles and building windows have been developed as one of energy saving measures for reducing carbon dioxide. About heat ray shielding imparting material, from the viewpoint of heat ray shielding properties (acquisition rate of solar heat), re-radiation of absorbed light into the room (about 1/3 of the absorbed solar energy is emitted into the room) A heat ray reflective type that does not re-emit in the first place is preferable to a certain heat ray absorbing type. Therefore, various proposals have been made for heat ray reflective heat ray shielding imparting materials.

  For example, a metal Ag thin film is generally used as a heat ray reflecting material because of its high reflectance, but it reflects not only visible light and heat rays but also radio waves, so that it has visible light permeability and radio wave permeability. Low was a problem. Low-E glass (for example, manufactured by Asahi Glass Co., Ltd.) using Ag and ZnO multilayer film is widely used in buildings in order to increase visible light transmittance, but Low-E glass is made of metal Ag on the glass surface. Since the thin film was formed, there existed a subject that radio wave permeability was low.

  In order to solve the above problems, for example, glass with island-shaped Ag particles imparted with radio wave permeability has been proposed. Moreover, the glass which formed granular Ag by annealing the Ag thin film formed by vapor deposition is proposed (refer patent document 1).

  Alternatively, an infrared reflective layer in which 5 to 200 layers of at least two transparent thin layers having different refractive indexes are alternately laminated, such as a polymer multilayer extruded film, and a dispersion film of conductive fine particles such as tin-doped indium oxide (ITO) A polymer multilayer extruded film, which is a functional film having an infrared absorbing layer made of, has been proposed (see Patent Document 2).

Japanese Patent No. 3454422 JP 2010-222233 A

However, in the glass described in Patent Document 1, since granular Ag is formed by annealing, it is difficult to control the particle size, shape, area ratio, etc., control of the reflection wavelength, band, etc. of heat rays, visible light transmission As a result, it is difficult to improve the rate, and as a result, there is a problem that infrared rays on the short wavelength side where solar energy is high in infrared light cannot be sufficiently shielded.
Further, in the functional film described in Patent Document 2, the polymer multilayer extruded film is effective for reflection in the infrared region, but in order to keep the visible light region transparent, the generation of the second harmonic in the visible light region is prevented. Therefore, it is necessary to limit the infrared reflection region to around 800 to 1,100 nm. Therefore, in this proposal, infrared shielding after 1,100 nm is supplemented with an infrared absorbing layer containing ITO or the like. In that case, since there are many components that easily change to heat, there is a problem that the suppression of heat generation is insufficient and the shielding coefficient is not sufficiently low. In addition, when the infrared shielding filter is attached to a window glass, the temperature rises differently in places where it is not exposed to sunlight, so the glass breaks due to the difference in the expansion coefficient of the film, so-called thermal cracking phenomenon There was a problem that happened.
Therefore, there is a demand for a heat ray shielding material having improved infrared reflectance over the entire band and having high light transmittance in the visible light region, and a laminated structure and laminated glass using the heat ray shielding material. It is.

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention provides a heat ray shielding material, a laminated structure using such a heat ray shielding material, and a laminated glass that achieves high light transmittance in the visible light region while improving infrared reflectance over a wide band. The purpose is to provide.

Means for solving the above problems are as follows. That is,
<1> a metal particle-containing layer containing at least one metal particle;
An infrared reflective layer in which 5 to 200 layers of at least two transparent thin layers having different refractive indexes are alternately laminated, and a heat ray shielding material,
The metal particles include hexagonal or circular and flat metal particles,
The heat ray shielding material, wherein the ratio of the flat metal particles to the total number of metal particles contained in the metal particle-containing layer is 60% by number or more.
<2> The transparent thin layer is the heat ray shielding material according to <1>, which is a layer containing a polymer.
<3> The infrared ray reflective layer is a heat ray shielding material according to <1> or <2>, which is obtained by executing transparent lamination, at least one of alternate lamination extrusion, alternate application, and alternate thin lamination. is there.
<4> The heat ray shielding material according to any one of <1> to <3>, wherein the difference between the maximum wavelength of the reflection spectrum of the infrared reflection layer and the maximum wavelength of the reflection spectrum of the metal particle-containing layer is 100 nm or more. is there.
<5> The maximum wavelength of the reflection spectrum of the infrared reflection layer is 700 nm to 1,500 nm, the maximum wavelength of the reflection spectrum of the metal particle-containing layer is 900 nm to 2,000 nm, and the shielding coefficient is 0.7 or less. It is a heat ray shielding material in any one of <1> to <4>.
<6> The flat metal particles in which the main plane is plane-oriented in the range of 0 ° to ± 30 ° with respect to one surface of the metal particle-containing layer with respect to the total number of the flat metal particles. The heat ray shielding material according to any one of <1> to <5>, wherein the ratio is 50% by number or more.
<7> The flat metal particles in which the main plane is plane-oriented in the range of 0 ° to ± 30 ° with respect to one surface of the metal particle-containing layer with respect to the total number of flat metal particles. The heat ray shielding material according to any one of <1> to <6>, wherein the ratio is 80% by number or more.
<8> The flat metal particles in which the main plane is plane-oriented in the range of 0 ° to ± 30 ° with respect to one surface of the metal particle-containing layer with respect to the total number of the flat metal particles. The heat ray shielding material according to any one of <1> to <7>, wherein the ratio is 90% by number or more.
<9> The heat ray shielding material according to any one of <1> to <8>, wherein a coefficient of variation in particle size distribution of the flat metal particles is 30% or less.
<10> The average particle size of the flat metal particles is 70 nm to 500 nm,
The heat ray shielding material according to any one of <1> to <9>, wherein the flat metal particles have an aspect ratio (average particle diameter / average particle thickness) of 10 to 45.
<11> The heat ray shielding material according to any one of <1> to <10>, wherein the flat metal particles include at least silver.
<12> The heat ray shielding material according to any one of <1> to <11>, wherein the visible light transmittance of the heat ray shielding material is 70% or more.
<13> The heat ray shielding material according to any one of <1> to <12>, further including an adhesive layer.
<14> A laminated structure comprising the heat ray shielding material according to any one of <1> to <13> and any one of glass and plastic.
<15> At least one heat ray shielding material according to any one of <1> to <12>, at least two intermediate layers that sandwich the heat ray shielding material, and at least two glasses that sandwich the intermediate layer It is the laminated glass characterized by including.
<16> The laminated glass according to <15>, wherein the intermediate layer contains at least one of polyvinyl butyral and an ethylene vinyl copolymer.

  According to the present invention, it is possible to solve the problems of the prior art, achieve the above-mentioned object, improve the infrared reflectance over a wide band, and simultaneously achieve high light transmittance in the visible light region, In addition, a laminated structure and a laminated glass using the heat ray shielding material can be provided.

FIG. 1A is a schematic perspective view showing an example of the shape of flat metal particles contained in the heat ray shielding material of the present invention, and shows circular and flat metal particles. FIG. 1B is a schematic perspective view showing an example of the shape of flat metal particles contained in the heat ray shielding material of the present invention, and shows hexagonal flat metal particles. FIG. 2A is a schematic cross-sectional view showing the existence state of a metal particle-containing layer containing flat metal particles in the heat ray shielding material of the present invention, and shows the most ideal existence state. FIG. 2B is a schematic cross-sectional view showing the existence state of the metal particle-containing layer containing flat metal particles in the heat ray shielding material of the present invention, and one surface of the metal particle-containing layer and the flat metal particles The figure explaining the angle ((theta)) which makes with a plane is shown. FIG. 2C is a schematic cross-sectional view showing the existence state of a metal particle-containing layer containing flat metal particles in the heat ray shielding material of the present invention, and the presence of the metal particle-containing layer in the depth direction of the heat ray shielding material. It is a figure which shows an area | region. FIG. 3 is a graph showing a transmission spectrum, a reflection spectrum, and an absorption spectrum in the heat ray shielding material of Comparative Example 4. FIG. 4 is a graph showing a reflection spectrum in the heat ray shielding material of Comparative Example 1.

(Heat ray shielding material)
The heat ray shielding material of the present invention has a metal particle-containing layer containing at least one kind of metal particles, and an infrared reflective layer in which at least two kinds of transparent thin layers having different refractive indexes are alternately laminated. Furthermore, it has other layers, such as a pressure-sensitive adhesive layer, appropriately selected as necessary.

<Metal particle content layer>
If a metal particle content layer is a layer containing at least 1 sort (s) of metal particle, there will be no restriction | limiting in particular, According to the objective, it can select suitably.

-Metal particles-
The metal particles are not particularly limited as long as they contain flat metal particles, and can be appropriately selected according to the purpose. For example, in addition to flat metal particles, granular, cubic, hexahedral, Examples include a face shape and a rod shape.
In the metal particle-containing layer, the presence state of the metal particles may be unevenly distributed in one plane facing a substantially horizontal direction with respect to one surface of the metal particle-containing layer (the surface of the infrared reflecting layer), or randomly. However, it is preferable to be unevenly distributed in one plane in the substantially horizontal direction. The form unevenly distributed in one plane facing the substantially horizontal direction is not particularly limited and can be appropriately selected according to the purpose. For example, the form in which the infrared reflective layer and the metal particles are substantially in contact, the infrared reflective layer And the metal particles are arranged at a certain distance in the depth direction of the heat ray shielding material.
In addition, one surface of the metal particle-containing layer is a surface in contact with the infrared reflective layer, and is a flat plane similarly to the surface of the infrared reflective layer.
There is no restriction | limiting in particular as a magnitude | size of a metal particle, According to the objective, it can select suitably, For example, you may have an average particle diameter of 500 nm or less.
The material of the metal particles is not particularly limited and can be appropriately selected according to the purpose. However, silver, gold, aluminum, copper, rhodium, nickel, platinum are preferred because of the high heat ray (near infrared) reflectance. Etc. are preferable.

-Flat metal particles-
The flat metal particles are not particularly limited as long as they are particles composed of two main planes (see FIGS. 1A and 1B), and can be appropriately selected according to the purpose. For example, a hexagonal shape, a circular shape, Examples include a triangle shape. Among these, a hexagonal shape and a circular shape are particularly preferable in terms of high visible light transmittance.
The circular shape is not particularly limited as long as it has no corners and round shape when the flat metal particles are observed from above the main plane with a transmission electron microscope (TEM), and is appropriately selected according to the purpose. be able to.
The hexagonal shape is not particularly limited as long as it is a hexagonal shape when the flat metal particles are observed from above the main plane with a transmission electron microscope (TEM), and can be appropriately selected according to the purpose. For example, the hexagonal corners may be sharp or dull, but the corners are preferably dull in that the absorption in the visible light region can be reduced. There is no restriction | limiting in particular as a grade of the dullness of an angle | corner, According to the objective, it can select suitably.
There is no restriction | limiting in particular as a material of a flat metal particle, The same thing as a metal particle can be suitably selected according to the objective. The flat metal particles preferably contain at least silver.

  Of the metal particles present in the metal particle-containing layer, the hexagonal or circular plate-like metal particles are 60% by number or more, preferably 65% by number or more, and 70 by number with respect to the total number of metal particles. % Or more is more preferable. If the proportion of the flat metal particles is less than 60% by number, the visible light transmittance may be lowered.

[Plane orientation]
In the heat ray shielding material of the present invention, the planar metal particles have a plane orientation in the range of 0 ° to ± 30 ° with respect to one surface of the metal particle-containing layer (or the surface of the infrared reflective layer). It is preferable that the plane orientation is in the range of 0 ° to ± 20 °. Further, the ratio of the flat metal particles in which the main plane is plane-oriented in the range of 0 ° to ± 30 ° with respect to one surface of the metal particle-containing layer with respect to the total number of the flat metal particles. Is preferably 50% by number or more, more preferably 80% by number or more, and still more preferably 90% by number or more. The number of tabular metal particles whose main plane is plane-oriented in the range of 0 ° to ± 30 ° with respect to one surface of the metal particle-containing layer with respect to the total number of tabular metal particles. As the ratio is larger, the infrared reflection performance is improved and the haze is reduced, so that the transparency of the heat ray shielding material is improved.
The presence state of the flat metal particles is not particularly limited and may be appropriately selected depending on the purpose. However, it is preferable that the flat metal particles are arranged on the infrared reflecting layer as shown in FIG.

Here, FIG. 2A to FIG. 2C are schematic cross-sectional views showing the existence state of the metal particle-containing layer containing flat metal particles in the heat ray shielding material of the present invention. FIG. 2A shows the most ideal existence state of the plate-like metal particles 3 in the metal particle-containing layer 2. FIG. 2B is a diagram for explaining an angle (± θ) formed by the plane of the infrared reflecting layer 1 and the plane of the flat metal particle 3. FIG. 2C shows the existence region in the depth direction of the heat ray shielding material of the metal particle-containing layer 2.
In FIG. 2B, the angle (± θ) formed between the surface of the infrared reflective layer 1 and the main plane or extension of the main plane of the flat metal particles 3 corresponds to a predetermined range in the plane orientation. That is, the plane orientation means a state in which the inclination angle (± θ) shown in FIG. 2B is small when the cross section of the heat ray shielding material is observed. In particular, FIG. 2A shows the surface of the infrared reflecting layer 1 and the flat metal particles. 3 is in contact with the main plane, that is, a state where θ is 0 °. When the angle of the plane orientation of the main plane of the flat metal particles 3 with respect to the surface of the infrared reflecting layer 1, that is, θ in FIG. 2B exceeds ± 30 °, a predetermined wavelength of the heat ray shielding material (for example, a visible light region long wavelength) The reflectance in the near infrared light region from the side is reduced.

[Evaluation of plane orientation]
The evaluation of whether or not the main plane of the flat metal particles is plane-oriented with respect to one surface of the metal particle-containing layer (or the surface of the infrared reflective layer) is not particularly limited and is appropriately selected according to the purpose. For example, a method may be used in which an appropriate cross section is prepared and the metal particle-containing layer and the flat metal particles in the slice are observed and evaluated. Specifically, as a heat ray shielding material, a microtome and a focused ion beam (FIB) are used to prepare a cross-sectional sample or a cross-section sample of the heat ray shielding material, and this is used for various microscopes (for example, a field emission scanning electron microscope ( FE-SEM) etc.) and the method of evaluating from images obtained by observation.

  In the heat ray shielding material, when the binder that covers the flat metal particles swells with water, the sample frozen in liquid nitrogen is cut with a diamond cutter mounted on a microtome to obtain a cross-section sample or a cross-section sample. May be produced. Moreover, when the binder which coat | covers a flat metal particle in a heat ray shielding material does not swell with water, you may produce a cross-section sample thru | or a cross-section piece sample.

  As the observation of the cross-section sample or cross-section sample prepared as described above, in the sample, the main plane of the plate-like metal particles is plane-oriented with respect to one surface of the metal particle-containing layer (or the surface of the infrared reflective layer). If it can confirm whether it exists, it will not restrict | limit in particular, According to the objective, it can select suitably, For example, observation using FE-SEM, TEM, an optical microscope etc. is mentioned. In the case of a cross-section sample, observation may be performed by FE-SEM, and in the case of a cross-section sample, observation may be performed by TEM. When evaluating by FE-SEM, it is preferable to have a spatial resolution with which the shape and inclination angle (± θ in FIG. 2B) of the flat metal particles can be clearly determined.

[Average particle diameter (average equivalent circle diameter) and average particle diameter (average equivalent circle diameter) particle size distribution]
There is no restriction | limiting in particular as an average particle diameter (average equivalent circle diameter) of a flat metal particle, Although it can select suitably according to the objective, 70 nm-500 nm are preferable, and 80 nm-400 nm are more preferable. When the average particle diameter (average equivalent circle diameter) is less than 70 nm, the contribution of the absorption of the flat metal particles is larger than the reflection, so that sufficient heat ray reflectivity may not be obtained. Haze (scattering) increases, and the transparency of the heat ray shielding material may be impaired.
Here, the average particle diameter (average equivalent circle diameter) is an average value of main plane diameters (maximum lengths) of 200 flat metal particles arbitrarily selected from images obtained by observing particles with a TEM. Means.
Two or more kinds of metal particles having different average particle diameters (average equivalent circle diameters) can be included in the metal particle-containing layer. In this case, two or more peaks of the average particle diameter (average equivalent circle diameter) of the metal particles are present. That is, you may have two average particle diameters (average circle equivalent diameter).

In the heat ray shielding material of the present invention, the coefficient of variation in the particle size distribution of the flat metal particles is preferably 30% or less, and more preferably 20% or less. When the variation coefficient exceeds 30%, the reflection wavelength region of the heat ray in the heat ray shielding material may become broad.
Here, the coefficient of variation in the particle size distribution of the flat metal particles is plotted, for example, by plotting the particle size distribution range of the 200 flat metal particles used for calculating the average value obtained as described above. The standard deviation is obtained, and is a value (%) divided by the average value (average particle diameter (average equivalent circle diameter)) of the main plane diameter (maximum length) obtained as described above.

[aspect ratio]
There is no restriction | limiting in particular as an aspect-ratio of a flat metal particle, Although it can select suitably according to the objective, From the point from which the reflectance in the infrared region of wavelength 900nm-2,000nm becomes high, it is 10 -45 are preferable and 20-35 are more preferable. When the aspect ratio is less than 10, the reflection wavelength becomes smaller than 900 nm, and when it exceeds 45, the reflection wavelength becomes longer than 2,000 nm and sufficient heat ray reflectivity may not be obtained.
The aspect ratio means a value obtained by dividing the average particle diameter (average equivalent circle diameter) of the flat metal particles by the average particle thickness of the flat metal particles. The average particle thickness corresponds to the distance between the main planes of the flat metal particles, and is, for example, as shown in FIGS. 1A and 1B and can be measured by an atomic force microscope (AFM).
The method for measuring the average particle thickness by AFM is not particularly limited and can be appropriately selected depending on the purpose.For example, a particle dispersion containing flat metal particles is dropped onto a glass substrate and dried. For example, a method of measuring the thickness of one particle may be used.

[Existence range of flat metal particles]
In the heat ray shielding material of the present invention, as shown in FIG. 2C, the plasmon resonance wavelength of the metal constituting the flat metal particle 3 in the metal particle-containing layer 2 is λ, and the refractive index of the medium in the metal particle-containing layer 2 is When it is set to n, it is preferable that the metal particle content layer 2 exists in the range of 0-((lambda) / n) / 4 in the depth direction from the horizontal surface of a heat ray shielding material. Outside this range, the effect of increasing the amplitude of the reflected wave due to the phase of the reflected wave at the interface air interface between the upper and lower metal particle-containing layers of the heat ray shielding material is reduced, haze characteristics, The visible light transmittance and the maximum heat ray reflectance may decrease.

The plasmon resonance wavelength λ of the metal constituting the flat metal particles in the metal particle-containing layer is not particularly limited and can be appropriately selected according to the purpose, but is 400 nm to 2 in terms of imparting heat ray reflection performance. , 500 nm, preferably 700 nm to 2,500 nm from the viewpoint of imparting visible light transmittance.
There is no restriction | limiting in particular as a medium in a metal particle content layer, According to the objective, it can select suitably, For example, polyvinyl acetal resin, polyvinyl alcohol resin, polyvinyl butyral resin, polyacrylate resin, polymethylmethacrylate resin, polycarbonate resin , Polyvinyl chloride resin, saturated polyester resin, polyurethane resin, polymers such as natural polymers such as gelatin and cellulose, and inorganic substances such as silicon dioxide and aluminum oxide.
The refractive index n of the medium is preferably 1.4 to 1.7.

[Area ratio of flat metal particles]
The area of the plate-like metal particles relative to the area A of the heat ray shielding material when the heat ray shielding material is viewed from above (the total projected area A of the metal particle containing layer when viewed from the direction perpendicular to the metal particle containing layer) The area ratio [(B / A) × 100], which is the ratio of the total value B, is preferably 15% or more, and more preferably 20% or more. When the area ratio is less than 15%, the maximum reflectance of the heat ray is lowered, and the heat shielding effect may not be sufficiently obtained.
Here, the area ratio can be measured, for example, by performing image processing on an image obtained by SEM observation of the heat ray shielding material from above or an image obtained by AFM (atomic force microscope) observation.

[Average distance between flat metal particles]
The average inter-particle distance between the flat metal particles adjacent in the horizontal direction in the metal particle-containing layer is 1/10 of the average particle diameter of the flat metal particles in terms of the visible light transmittance and the maximum reflectance of the heat ray. The above is preferable.
When the average interparticle distance in the horizontal direction of the flat metal particles is less than 1/10 of the average particle diameter of the flat metal particles, the maximum reflectivity of the heat rays is lowered. Further, the average interparticle distance in the horizontal direction is preferably non-uniform (random) in terms of visible light transmittance. If it is not random, that is, if it is uniform, absorption of visible light occurs, and the transmittance may decrease.

  Here, the horizontal average interparticle distance of the flat metal particles means an average value of interparticle distances between two adjacent particles. In addition, the average distance between the particles means that “other than the origin when taking a two-dimensional autocorrelation of luminance values when binarizing an SEM image including 100 or more tabular metal particles. Does not have a significant local maximum. "

[Layer structure of metal particle-containing layer]
In the heat ray shielding material of the present invention, the flat metal particles are arranged in the form of a metal particle-containing layer containing flat metal particles, as shown in FIGS. 2A to 2C.
As a metal particle content layer, as shown to FIG. 2A-FIG. 2C, it may be comprised by the single layer, and may be comprised by the some metal particle content layer. When comprised with a several metal particle content layer, it becomes possible to provide the shielding performance according to the wavelength range | band which wants to provide heat insulation performance.
There is no restriction | limiting in particular as thickness of a metal particle content layer, Although it can select suitably according to the objective, when an actual application | coating and drying load are considered, 0.01 micrometer-1 micrometer are preferable, and 0.02 micrometer-0.00. 5 μm is more preferable.
Here, the thickness of each layer of the metal particle-containing layer can be measured, for example, from an image obtained by SEM observation of a cross-sectional sample of the heat ray shielding material.

[Method for synthesizing flat metal particles]
The method for synthesizing the flat metal particles is not particularly limited as long as it can synthesize a hexagonal shape or a circular shape, and can be appropriately selected according to the purpose. For example, a chemical reduction method, a photochemical reduction method, Examples thereof include a liquid phase method such as an electrochemical reduction method. Among these, a liquid phase method such as a chemical reduction method or a photochemical reduction method is particularly preferable in terms of shape and size controllability. After synthesizing hexagonal or triangular plate-like metal particles, for example, by performing etching treatment with a dissolved species that dissolves silver such as nitric acid or sodium sulfite, aging treatment by heating, etc., hexagonal or triangular plate The corners of the metal particles may be blunted to obtain hexagonal or circular flat metal particles.

  As a method for synthesizing the flat metal particles, in addition to the above, after seed crystals are fixed in advance on the surface of a transparent substrate such as a film or glass, the metal particles (for example, Ag) may be crystal-grown in a flat shape.

  In the heat ray shielding material of the present invention, the flat metal particles may be subjected to further treatment in order to impart desired characteristics. The further treatment is not particularly limited and may be appropriately selected depending on the purpose. For example, the formation of a high refractive index shell layer, the addition of various additives such as a dispersant and an antioxidant may be included. Can be mentioned.

-Formation of high refractive index shell layer-
The plate-like metal particles may be coated with a high refractive index material having high visible light region transparency in order to further enhance the visible light region transparency.
As the high refractive index material is not particularly limited and may be appropriately selected depending on the purpose, for _example, TiO _x, BaTiO _3, ZnO, etc. SnO _2, ZrO _2, NbO _x and the like.

There is no restriction | limiting in particular as a method to coat | cover, According to the objective, it can select suitably, For example, Langmuir, 2000, 16 volumes, p. As reported in 2731-2735, a method of forming a TiO _x layer on the surface of silver tabular metal particles by hydrolyzing tetrabutoxy titanium may be used.

In addition, when it is difficult to form a high refractive index metal oxide layer shell directly on the flat metal particles, after synthesizing the flat metal particles as described above, an appropriate SiO ₂ or polymer shell layer is formed. Furthermore, a metal oxide layer may be formed on the shell layer. When TiO _x is used as a material for the high refractive index metal oxide layer, since TiO _x has photocatalytic activity, there is a concern that the matrix in which the flat metal particles are dispersed may be deteriorated. After forming the TiO _x layer on the flat metal particles, an SiO ₂ layer may be appropriately formed.

-Addition of various additives-
In the heat ray shielding material of the present invention, the flat metal particles adsorb an antioxidant such as mercaptotetrazole and ascorbic acid in order to prevent oxidation of metals such as silver constituting the flat metal particles. May be. Further, for the purpose of preventing oxidation, an antioxidant layer such as Ni may be formed on the surface of the flat metal particles. Further, it may be covered with a metal oxide film such as SiO ₂ for the purpose of blocking oxygen.

  For the purpose of imparting dispersibility, the flat metal particles are, for example, quaternary ammonium salts, low molecular weight dispersants containing at least one of N elements such as amines, S elements, and P elements, and high molecular weight dispersants. A dispersant may be added.

<Infrared reflective layer>
The infrared reflection layer is not particularly limited as long as at least two types of transparent thin layers having different refractive indexes are alternately laminated, and can be appropriately selected according to the purpose.
The infrared reflective layer is preferably an infrared reflective layer (organic multilayer film) in which 20 to 200 layers of at least two kinds of polymers having different refractive indexes are alternately laminated, and alternately laminated, alternately laminated extruded, alternately coated, and alternately thinned. More preferably, it is at least one of layer laminates.

<< Transparent thin layer >>
The transparent thin layer has a visible light transmittance of 70% or more, has a thickness of 50 nm to 300 nm, and may be a thin layer made of a polymer.
The thickness of the transparent thin layer is not particularly limited as long as it is 50 nm to 300 nm, and can be appropriately selected according to the purpose, but is preferably 70 nm to 200 nm. Moreover, as thickness of the transparent thin layer which consists of a different material, it may mutually differ between different materials, and may be the same. Moreover, as thickness of the transparent thin layer which consists of 1 type of material, it may mutually differ between several transparent thin layers, and may be the same.
“The refractive indexes are different from each other” means that at least two kinds of transparent thin layers have different refractive indexes of 0.01 or more, and when the transparent thin layer is a thin layer made of a polymer, it differs by 0.02 or more. It is preferable.

-Polymer-
The polymer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polymethyl methacrylate, polyethylene terephthalate, polyethylene, polystyrene, polyethylene naphthalate, polycarbonate, a copolymer of polyvinylidene fluoride and polymethyl methacrylate , A copolymer of ethylene and an unsaturated monocarboxylic acid, a copolymer of styrene and methyl methacrylate, and the like.
The method for alternately laminating the polymers is not particularly limited, and a known method can be appropriately selected according to the purpose. For example, a lamination extrusion method, a roll coating method, a flow coating method, a dipping method, or the like can be applied. And a method of laminating a thin polymer layer.

  In addition, the infrared reflective layer is formed as a unit laminate by alternately laminating 10 to 40 polymer thin layers having different refractive indices of thickness t1 and polymer thin layers having thickness t2, and changing the thicknesses t1 and t2. It is preferable to have 2 to 6 unit laminated bodies in that the range of the reflection wavelength can be widened.

  The thickness of the infrared reflective layer, that is, the total thickness of the plurality of transparent thin layers is not particularly limited and can be appropriately selected according to the purpose. However, the infrared reflective layer has at least two kinds of refractive indexes different from each other. When the polymer is an infrared reflective layer (organic multilayer film) in which 20 to 200 layers are alternately laminated, 30 to 200 μm is preferable, and 50 to 100 μm is more preferable.

  It is preferable that the maximum wavelength of the reflection spectrum of the infrared reflection layer is 700 nm to 1,500 nm, the maximum wavelength of the reflection spectrum of the metal particle-containing layer is 900 nm to 2,000 nm, and the shielding coefficient is 0.7 or less. Moreover, it is preferable that the difference between the maximum wavelength of the reflection spectrum of the infrared reflection layer and the maximum wavelength of the reflection spectrum of the metal particle-containing layer is 100 nm or more. Further, the shielding coefficient is more preferably 0.65 or less, and particularly preferably 0.6 or less.

<Other layers>
<< Adhesive layer >>
The heat ray shielding material of the present invention preferably further has an adhesive layer.
The material that can be used for forming the adhesive layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polyvinyl butyral (PVB) resin, acrylic resin, styrene / acrylic resin, urethane resin, polyester resin , Silicone resin, polyvinylpyrrolidone resin and the like. These may be used individually by 1 type and may use 2 or more types together. An adhesive layer made of these materials can be formed by coating.
Furthermore, you may add an antistatic agent, a lubricant, an antiblocking agent, etc. to the adhesion layer.
The thickness of the adhesive layer is preferably 0.1 μm to 10 μm.

<< Protective layer >>
In the heat ray shielding material of the present invention, it is preferable to have a protective layer in order to improve adhesion to the infrared reflective layer or to protect it from mechanical strength.
There is no restriction | limiting in particular in a protective layer, Although it can select suitably according to the objective, For example, it contains a binder and surfactant, and also contains another component as needed.
The binder is not particularly limited and may be appropriately selected depending on the intended purpose. For example, acrylic resin, polyvinyl butyral, polyvinyl alcohol, polyethylene vinyl copolymer, polyester, polyurethane, nylon, polyimide, polyamide, polyolefin, diacetyl Examples thereof include cellulose, polyvinyl chloride, and polyvinyl pyrrolidone. As a method for forming the protective layer, an appropriate organic solvent is selected as a solution, applied to the surface of the metal particle-containing layer, and then dried to form a thin film, or depending on the resin, a water-soluble emulsion is prepared. For example, a method of forming a thin film by coating the surface of the metal particle-containing layer as an aqueous solution and then heat drying to fuse the emulsion particles.

[Method of manufacturing heat ray shielding material]
There is no restriction | limiting in particular as a manufacturing method of the heat ray shielding material of this invention, According to the objective, it can select suitably, For example, a metal particle content layer is further added to the surface of an infrared reflective layer by the apply | coating method, Furthermore, as needed. The method of forming other layers, such as an adhesion layer, is mentioned.

-Method for forming metal particle-containing layer-
The method for forming the metal particle-containing layer is not particularly limited and can be appropriately selected depending on the purpose.For example, a dispersion having flat metal particles on the surface of a lower layer such as an infrared reflective layer, Examples thereof include a method of coating by a dip coater, a die coater, a slit coater, a bar coater, a gravure coater, and the like, and a method of surface orientation by a method such as an LB film method, a self-organization method, and spray coating.

  In addition, the method for forming the metal particle-containing layer includes a method in which plane orientation is performed using electrostatic interaction in order to improve the adsorptivity to the infrared reflective layer surface and plane orientation of the flat metal particles. You may go out. As such a method, for example, when the surface of the flat metal particle is negatively charged (for example, dispersed in a negatively charged medium such as citric acid), the surface of the infrared reflective layer is positively And a method of aligning the surface by electrostatically enhancing the surface orientation by charging (for example, modifying the surface of the infrared reflecting layer with an amino group or the like). If the surface of the flat metal particles is hydrophilic, a hydrophilic / hydrophobic sea-island structure is formed on the surface of the infrared reflecting layer by using a block copolymer, microcontact stamp method, etc., and the hydrophilic / hydrophobic interaction is utilized. Thus, the plane orientation and the interparticle distance of the flat metal particles may be controlled.

  In addition, in order to accelerate | stimulate plane orientation, you may make it accelerate | stimulate by passing through pressure-bonding rollers, such as a calender roller and a laminating roller, after apply | coating a flat metal particle.

--Method of forming adhesive layer--
The adhesive layer is preferably formed by coating. For example, it can be laminated on the surface of a lower layer such as an infrared reflecting layer, a metal particle-containing layer, or an ultraviolet absorbing layer. There is no limitation in particular as the coating method at this time, A well-known method can be used.

The solar radiation reflectance of the heat ray shielding material of the present invention preferably has a maximum value in the range of 600 nm to 2,000 nm (preferably 800 nm to 1,800 nm) in that the efficiency of the heat ray reflectance can be increased. .
The visible light transmittance of the heat ray shielding material of the present invention is preferably 60% or more, and more preferably 70% or more. When the visible light transmittance is less than 60%, for example, when used as glass for automobiles or glass for buildings, the outside may be difficult to see.
The haze of the heat ray shielding material of the present invention is preferably 20% or less. If the haze exceeds 20%, it may be unfavorable in terms of safety, for example, when it is used as automotive glass or building glass, it becomes difficult to see the outside.

[Lamination of adhesive layer by dry lamination]
When using the heat ray shielding material of the present invention to add functionality to existing window glass, an adhesive layer is laminated and attached to the indoor side of the glass. In this case, since the heat generation is prevented when the reflective layer is directed to the sunlight side as much as possible, it is appropriate to laminate an adhesive layer on the metal particle-containing layer and attach the surface to the window glass.
When laminating the pressure-sensitive adhesive layer on the surface of the metal particle-containing layer, a coating solution containing a pressure-sensitive adhesive can be applied directly to the surface, but various additives, plasticizers and solvents used in the pressure-sensitive adhesive However, in some cases, the arrangement of the metal particle-containing layer may be disturbed, or the metal particles themselves may be altered. In order to minimize such harmful effects, a film is prepared by previously applying and drying an adhesive on a release film, and the adhesive surface of the film and the metal particles of the heat ray shielding material of the present invention are used. It is effective to laminate in a dry state by laminating the surface of the containing layer.

(Laminated structure)
The bonding structure of the present invention is formed by bonding the heat ray shielding material of the present invention and either glass or plastic.
There is no restriction | limiting in particular as a manufacturing method of a bonding structure, According to the objective, it can select suitably, The heat ray shielding material of this invention which has the adhesion layer manufactured as mentioned above is used for glass for vehicles, such as a motor vehicle. Or a method of bonding to glass or plastic for building materials or plastic.

(Laminated glass)
The laminated glass of the present invention includes at least one heat ray shielding material of the present invention, at least two intermediate layers, and at least two glasses, and the intermediate layer sandwiching the heat ray shielding material is at least two glasses. Hold it.
The intermediate layer preferably contains at least one of polyvinyl butyral and ethylene vinyl copolymer.
There is no restriction | limiting in particular as a manufacturing method of a laminated glass, According to the objective, it can select suitably, The heat ray shielding material of this invention is laminated | stacked between two intermediate | middle layers, such as polyvinyl butyral and an ethylene vinyl copolymer. Furthermore, after the intermediate layer is sandwiched between two pieces of glass, for example, autoclaving under conditions of 130 ° C., 13 atm, and 1 hour may be used.

  The glass is not particularly limited and can be appropriately selected according to the purpose.For example, it has good smoothness, little distortion of the fluoroscopic image, little distortion due to wind and external force with a certain degree of rigidity, and in the visible light region. Examples thereof include soda lime glass called a transparent type or a clear type, which is excellent in permeation and has a reduced coloring component such as metal oxide by a float method obtained at a relatively low cost.

[Usage of heat ray shielding material, laminated structure and laminated glass]
The heat ray shielding material, the laminated structure and the laminated glass of the present invention are not particularly limited as long as they are used for selectively reflecting or absorbing heat rays (near infrared rays), and are appropriately selected according to the purpose. For example, a film for vehicles, a laminated structure or laminated glass, a film for building materials, a laminated structure or laminated glass, an agricultural film, and the like can be given. Among these, the film for vehicles, the laminated structure and the laminated glass, the film for building material, the laminated structure and the laminated glass are preferable from the viewpoint of energy saving effect.
In addition, in this invention, a heat ray (near infrared rays) means the near infrared rays (780 nm-1,800 nm) contained about 50% in sunlight.

Hereinafter, although an example and a comparative example of the present invention are given and explained, the present invention is not limited to these examples at all. In addition, a comparative example is not necessarily a well-known technique.
The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

(Production Example 1: Production of infrared reflective layer 1 (organic multilayer film))
[Infrared reflective layer 1] was produced by alternately laminating two types of thin polymer layers having different refractive indexes by the following procedure.
Polymethylmethacrylate (PMMA) was used for the low refractive polymer thin layer, and polyethylene terephthalate (PET) was used for the high refractive polymer thin layer. A low refractive index layer formed using PMMA is called a PMMA layer, and a high refractive index layer formed using PET is called a PET layer.

The PMMA layer was formed by applying a solution obtained by dissolving PMMA in 2-methoxyethyl acetate by a roll coating method. The refractive index was 1.49.
The PET layer was formed by applying PET pellets while melting them with an extruder. The refractive index of the PET layer was 1.65.

  20 layers of 0.144 μm PMMA layers and 0.159 μm PET layers are alternately laminated, and further, 10 layers of 0.165 μm PMMA layers and 0.183 μm PET layers are alternately laminated, and 15 layers of 0.187 μm PMMA layers and 0.207 μm PET layers are alternately stacked, and further 15 layers of 0.158 μm PMMA layers and 0.175 μm PET layers are alternately stacked. 15 layers of 0.172 μm PMMA layers and 0.191 μm PET layers were alternately laminated to produce [Infrared reflective layer 1]. There are 150 polymer thin layers in total.

(Production Example 2: Production of infrared reflective layer 2 (organic multilayer extruded film))
[Infrared reflective layer 2] was produced by alternately laminating two types of polymer thin layers having different refractive indexes by the following procedure.
The multilayer extrusion film forming apparatus described in US Pat. Nos. 3,773,882 and 3,759,647 is used to reflect light in the infrared region, while in the visible region, second and second. A three-component multilayer optical interference film that suppresses the 3rd and 4th order reflections was produced, thereby obtaining an apparently transparent multilayer extruded film reflecting the infrared rays of sunlight.
[Infrared reflective layer 2] comprises the following three polymer components: component A is a styrene-methyl methacrylate copolymer (P-359, Richardson's) having a refractive index of 1.57 and a density of 1.08. Component B is a methyl methacrylate-styrene copolymer (RPC-440, manufactured by Richardson Polymer Corporation) having a refractive index of 1.53 and a density of 1.13; and Component C Is polymethylmethacrylate (VS-100, manufactured by Rohm and Haas) having a refractive index of 1.49 and a density of 1.20.

According to the following procedure, a protective layer of polycarbonate sufficient to eliminate surface instability and impart mechanical properties was further provided on both sides of [infrared reflective layer 2].
This three-component film was coextruded to obtain a 165-layer film having ABCB repeating units. The three component feed block has 42 feed slots for component A, 82 feed slots for component B, and 41 feed slots for component C. Three separate extruders feedblock each polymer component at a rate of 8.5 kg / hr for component A, 9.0 kg / hr for component B, and 9.8 kg / hr for component C. Supplied to. As a protective layer, 6.8 kg / hr polycarbonate was coextruded on both surfaces of the film. The drop rate of the film was adjusted to show a strong primary reflectivity at 1,400 nm with a film thickness of about 204 μm (0.9 mil). As a result, an [infrared reflective layer 2] in which the layer thickness of component A was 148.6 nm, the layer thickness of component B was 76.3 nm, and the layer thickness of component C was 156.6 nm was obtained. Therefore, the optical thickness ratio fA of the first component A is 1/3, the optical thickness ratio fB of the second component B is 1/6, and the optical thickness ratio fC of the third component C is The refractive index of each component satisfies the relationship of the following formula.
At this time, the optical thickness ratio f _i is defined by the following equation.
(In the formula, ni represents the refractive index of the polymer i, and di represents the layer thickness of the polymer i.)

  [Infrared reflective layer 2] was found to exhibit strong primary reflection at a wavelength (λI) of 1,400 nm in the near-infrared spectral region. In [Infrared reflective layer 2], secondary, tertiary and quaternary reflections were suppressed. Therefore, secondary reflection at a wavelength of 700 nm (λI / 2) in the red region of visible light, tertiary reflection at a wavelength of 467 nm (λI / 3) in the blue region of visible light, and 350 nm in the ultraviolet region. All fourth-order reflections at a wavelength of (λI / 4) were suppressed.

(Production Example 3: Production of flat silver particle dispersion B1)
-Synthesis of tabular silver particles-
--Synthesis process of tabular core grains--
2.5 mL of 0.5 g / L polystyrene sulfonic acid aqueous solution was added to 50 mL of 2.5 mM sodium citrate aqueous solution and heated to 35 ° C. To this solution, 3 mL of 10 mM sodium borohydride aqueous solution was added, and 50 mL of 0.5 mM silver nitrate aqueous solution was added with stirring at 20 mL / min. This solution was stirred for 30 minutes to prepare a seed solution.
--First growth step of tabular silver particles--
Next, 87.1 mL of ion-exchanged water was added to 132.7 mL of a 2.5 mM sodium citrate aqueous solution and heated to 35 ° C. To this solution, 2 mL of 10 mM ascorbic acid aqueous solution was added, 42.4 mL of seed solution was added, and 79.6 mL of 0.5 mM aqueous silver nitrate solution was added at 10 mL / min with stirring.
--- Second growth step of tabular silver particles--
Next, after stirring the said solution for 30 minutes, 71.1 mL of 0.35M potassium hydroquinonesulfonate aqueous solution was added, and 200 g of 7 mass% gelatin aqueous solution was added. To this solution was added a white precipitate mixture formed by mixing 107 mL of a 0.25 M aqueous sodium sulfite solution and 107 mL of a 0.47 M aqueous silver nitrate solution. This was stirred for 300 minutes, and flat silver particle dispersion liquid a1 was obtained.

  In the obtained tabular silver particle dispersion a1, silver hexagonal silver tabular grains having an average equivalent circle diameter of 310 nm (hereinafter referred to as Ag hexagonal tabular grains) are generated. confirmed. Further, when the thickness of the Ag hexagonal tabular grains was measured with an atomic force microscope (Nanocute II, manufactured by Seiko Instruments Inc.), the average hexagonal tabular grains having an aspect ratio of 23.8 and 13 nm were formed. I understood.

  Add 0.75 mL of 1N NaOH to 16 mL of flat silver particle dispersion a1, add 24 mL of ion-exchanged water, and centrifuge at 5,000 rpm for 5 minutes in a centrifuge (Hokusan Co., Ltd. H-200N, Amble Rotor BN). Separation was performed to precipitate Ag hexagonal tabular grains. The supernatant liquid after centrifugation was discarded, 5 mL of water was added, and the precipitated Ag hexagonal tabular grains were redispersed to obtain tabular silver particle dispersion B1 of Production Example 3.

Next, various characteristics of the obtained tabular silver particles were evaluated as follows. The results are shown in Tables 1 and 2.
<< Evaluation of metal particles >>
-Ratio of flat metal particles, average particle diameter (average equivalent circle diameter), coefficient of variation-
The shape uniformity of tabular silver particles is the shape of 200 particles arbitrarily extracted from the observed SEM image, A is a hexagonal shape or circular shape, and the shape is an irregular shape such as a teardrop shape. And B was subjected to image analysis, and the ratio (number%) of the number of particles corresponding to A was determined.
Similarly, the particle diameter of 100 particles corresponding to A is measured with a digital caliper, the average value is defined as the average particle diameter (average equivalent circle diameter), and the standard deviation of the particle size distribution is the average particle diameter (average equivalent circle diameter). ) To obtain the coefficient of variation (%).

-Average particle thickness-
The obtained dispersion containing flat metal particles is dropped on a glass substrate and dried, and the thickness of one flat metal particle is measured by an atomic force microscope (AFM) (Nanocute II, manufactured by Seiko Instruments Inc.). ). The measurement conditions using AFM were a self-detecting sensor, DFM mode, measurement range: 5 μm, scanning speed: 180 seconds / frame, and data points: 256 × 256.

-Aspect ratio-
From the average particle diameter (average circle equivalent diameter) and average particle thickness of the obtained flat metal particles, the average particle diameter (average circle equivalent diameter) was divided by the average particle thickness to calculate the aspect ratio.

-Transmission spectrum of tabular silver particle dispersion-
The transmission spectrum of the obtained tabular silver particle dispersion was diluted with water and evaluated using an ultraviolet-visible near-infrared spectrometer (manufactured by JASCO Corporation, V-670).

[Preparation of coating solution 1]
A coating solution 1 having the composition shown below was prepared.
Composition of coating solution 1:
Polyester latex aqueous dispersion: Finetex ES-650
(Manufactured by DIC, solid content concentration 30% by mass) 28.2 parts by mass Surfactant A: Rapisol A-90
(Nippon Yushi Co., Ltd., solid content concentration: 1% by mass) 12.5 parts by mass Surfactant B: Aronactee CL-95
(Sanyo Chemical Industries, Ltd., solid content concentration 1% by mass) 15.5 parts by weight Flat silver particle dispersion B1 200 parts by weight Water 800 parts by weight

Example 1
On one surface of [Infrared reflective layer 1], coating solution 1 was applied using a wire bar so that the average thickness after drying was 0.08 μm. Then, it heated at 150 degreeC for 10 minute (s), dried and solidified, the metal particle content layer was formed, and the heat ray shielding material of Example 1 was produced.
The average thickness can be determined by peeling a part of the coating film with an adhesive tape and measuring the stepped portion between the base and the coating film with a stylus roughness meter (DEKTAK).

(Example 1-1: Production of heat ray shielding material having adhesive layer)
After cleaning the surface of the obtained heat ray shielding material, the adhesive layer was bonded together. As the pressure-sensitive adhesive, PD-S1 manufactured by Panac Co., Ltd. was used, and the surface of the pressure-sensitive adhesive peeled off was overlapped with the surface of the metal particle-containing layer of the heat ray shielding material and bonded together.
The heat ray shielding material which has the adhesion layer of Example 1-1 was produced by the above.

(Example 1-2: Production of bonded structure of heat ray shielding material)
The release sheet of the heat ray shielding material which has the obtained adhesion layer was peeled off, and it bonded with transparent glass (thickness: 3 mm), and produced the bonding structure of the heat ray shielding material of Example 1-2.
Note that the transparent glass used is one that has been wiped off with isopropyl alcohol and left to stand. At the time of bonding, a rubber roller is used and the surface pressure is 0.5 kg / cm ² at 25 ° C. and 65% humidity. Crimped.

(Example 1-3: Production of laminated glass)
The heat ray shielding material of Example 1 is sandwiched from both sides with a polyvinyl butyral film (thickness 0.38 mm, S-LECT B, manufactured by Sekisui Chemical Co., Ltd.), and further sandwiched between 2 mm thick glass plates from both sides of the laminate (each The size in the plane direction was 50 mm square). In that state, it was temporarily pressure-bonded through a roll laminator having a metal roll heated at 60 ° C. The temporarily pressure-bonded sample was put in an autoclave and subjected to main pressure bonding by autoclaving under conditions of 130 ° C., 13 atm and 1 hour to obtain a laminated glass of Example 1-3.

  Next, various characteristics of the obtained heat ray shielding material were evaluated as follows. The results are shown in Table 3.

<< Evaluation of heat ray shielding material >>
-Particle tilt angle-
After embedding the heat ray shielding material with an epoxy resin, the heat ray shielding material was cleaved with a razor in a frozen state with liquid nitrogen, and a vertical section sample of the heat ray shielding material was produced. The vertical cross-section sample is observed with a scanning electron microscope (SEM), and the inclination angle (corresponding to ± θ in FIG. 2B) of the 100 flat metal particles contained in the metal particle-containing layer with respect to the horizontal plane of the substrate. Calculated as an average value.

-Reflection spectrum and transmission spectrum measurement-
The reflection spectrum and transmission spectrum of the produced heat ray shielding material were measured using an ultraviolet-visible near-infrared spectrometer (manufactured by JASCO Corporation, V-670). For the reflection spectrum measurement, an absolute reflectance measurement unit (ARV-474, manufactured by JASCO Corporation) was used, and the incident light passed through a 45 ° polarizing plate and was made incident light that could be regarded as non-polarized light.

-Visible light transmittance-
About the produced heat ray shielding material, the value which correct | amended the transmittance | permeability of each wavelength measured from 380 nm to 780 nm with the spectral visibility of each wavelength was made visible light transmittance.

-Thermal insulation performance evaluation-
About the produced heat ray shielding material, the shielding coefficient was calculated | required based on the method of JIS5759 from the transmittance | permeability of each wavelength measured to 350 nm-2,100 nm, and the determination was performed. As evaluation of heat insulation performance, it is preferable that a shielding coefficient (0-1) is small.

(Example 2)
In Example 1, instead of [Infrared reflective layer 1], [Infrared reflective layer 2] was used, except that the coating liquid 1 was applied on one surface of [Infrared reflective layer 2]. In the same manner as in Example 2, the heat ray shielding material of Example 2, the heat ray shielding material having the adhesive layer of Example 2-1, the bonding structure of the heat ray shielding material of Example 2-2, and the combination of Example 2-3 Glass was produced.

(Comparative Example 1)
In Example 1, except that the coating liquid 1 was not applied, the heat ray shielding material of Comparative Example 1, the heat ray shielding material having the adhesive layer of Comparative Example 1-1, and Comparative Example 1 were the same as in Example 1. -2 heat ray shielding material laminated structure and Comparative Example 1-3 laminated glass were produced.

(Comparative Example 2)
In Example 1, it replaced with the coating liquid 1, and applied the ITO hard-coat coating liquid (Mitsubishi Materials Co., Ltd. EI-1) similarly to Example 1, and the heat ray shielding material of the comparative example 2, The heat ray shielding material which has the adhesion layer of the comparative example 2-1, the bonding structure of the heat ray shielding material of the comparative example 2-2, and the laminated glass of the comparative example 2-3 were produced.
The ITO particles have a transmittance of 1,400 nm to 2,200 nm of 10% or less and a visible transmittance of 90%.

(Comparative Example 3)
In Example 2, except that the coating liquid 1 was not applied, the heat ray shielding material of Comparative Example 3, the heat ray shielding material having the adhesive layer of Comparative Example 3-1, and Comparative Example 3 were the same as in Example 2. -2 heat ray shielding laminated structure and laminated glass of Comparative Example 3-3.

(Comparative Example 4)
In Example 1, instead of [Infrared reflective layer 1], a transparent PET film having a thickness of 100 μm was used, and the coating liquid 1 was applied on one surface of the PET film, as in Example 1. The heat ray shielding material of Comparative Example 4, the heat ray shielding material having the adhesive layer of Comparative Example 4-1, the laminated structure of the heat ray shielding material of Comparative Example 4-2, and the laminated glass of Comparative Example 4-3 Produced.

  About the heat ray shielding material of Example 2 and Comparative Examples 1-4, it carried out similarly to Example 1, and evaluated various characteristics. The results are shown in Table 3. Moreover, the spectrum of the comparative example 4 (only a metal particle content layer) is shown in FIG. 3, and the reflection spectrum of the comparative example 1 (only [infrared reflective layer 1]) is shown in FIG.

  From the results in Table 3, it was found that the heat ray shielding material of the present invention can improve the reflectance of infrared rays over a wide band and can achieve both high light transmittance in the visible light region.

  Since the heat ray shielding material of the present invention can improve the reflectance of infrared rays over a wide band and can achieve both high light transmittance in the visible light region, for example, films for vehicles such as automobiles and buses, bonded structures, As a laminated glass, a building material film, a laminated structure, a laminated glass, etc., it can be suitably used as various members that are required to prevent the transmission of heat rays.

DESCRIPTION OF SYMBOLS 1 Infrared reflective layer 2 Metal particle content layer 3 Flat metal particle

Claims (16)

A metal particle-containing layer containing at least one metal particle;
An infrared reflective layer in which 5 to 200 layers of at least two transparent thin layers having different refractive indexes are alternately laminated, and a heat ray shielding material,
The metal particles include hexagonal or circular and flat metal particles,
The heat ray shielding material, wherein the ratio of the flat metal particles to the total number of metal particles contained in the metal particle-containing layer is 60% by number or more.   The heat ray shielding material according to claim 1, wherein the transparent thin layer is a layer containing a polymer.   The said infrared reflective layer is a heat ray shielding material of Claim 1 or 2 obtained by performing at least any one of alternate lamination extrusion, alternate application | coating, and alternate thin layer lamination of the said transparent thin layer.   The heat ray shielding material according to any one of claims 1 to 3, wherein a difference between a maximum wavelength of a reflection spectrum of the infrared reflection layer and a maximum wavelength of a reflection spectrum of the metal particle-containing layer is 100 nm or more.   The maximum wavelength of the reflection spectrum of the infrared reflection layer is 700 nm to 1,500 nm, the maximum wavelength of the reflection spectrum of the metal particle-containing layer is 900 nm to 2,000 nm, and the shielding coefficient is 0.7 or less. The heat ray shielding material according to any one of claims 1 to 4.   Of the flat metal particles, the main plane is plane-oriented in the range of 0 ° to ± 30 ° with respect to one surface of the metal particle-containing layer with respect to the total number of particles of the flat metal particles. The heat ray shielding material according to any one of claims 1 to 5, wherein the ratio is 50% by number or more.   Of the flat metal particles, the main plane is plane-oriented in the range of 0 ° to ± 30 ° with respect to one surface of the metal particle-containing layer with respect to the total number of particles of the flat metal particles. The heat ray shielding material according to any one of claims 1 to 6, wherein the ratio is 80% by number or more.   Of the flat metal particles, the main plane is plane-oriented in the range of 0 ° to ± 30 ° with respect to one surface of the metal particle-containing layer with respect to the total number of particles of the flat metal particles. The heat ray shielding material according to any one of claims 1 to 7, wherein the ratio is 90% by number or more.   The heat ray shielding material according to any one of claims 1 to 8, wherein a variation coefficient of a particle size distribution of the flat metal particles is 30% or less. The flat metal particles have an average particle diameter of 70 nm to 500 nm,
The heat ray shielding material according to any one of claims 1 to 9, wherein an aspect ratio (average particle diameter / average particle thickness) of the flat metal particles is 10 to 45.   The heat ray shielding material according to any one of claims 1 to 10, wherein the flat metal particles contain silver.   The heat ray shielding material according to any one of claims 1 to 11, wherein the heat ray shielding material has a visible light transmittance of 70% or more.   The heat ray shielding material according to any one of claims 1 to 12, further comprising an adhesive layer.   A bonded structure comprising the heat ray shielding material according to any one of claims 1 to 13 and either glass or plastic.   The heat ray shielding material according to any one of claims 1 to 12, at least two intermediate layers that sandwich the heat ray shielding material, and at least two glasses that sandwich the intermediate layer. Laminated glass characterized by   The laminated glass of Claim 15 in which the said intermediate | middle layer contains at least any one of polyvinyl butyral and an ethylene vinyl copolymer.