JPH0226854B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a light-transmitting sheet that transmits visible light and absorbs or reflects infrared rays. More specifically, the present invention relates to a selectively transparent sheet that transmits visible light and absorbs or reflects near-infrared light to infrared light.

In general, by controlling the thickness of each component thin film in a laminate in which conductive metal thin films such as gold, silver, copper, and various alloys containing these as main components are sandwiched between transparent high refractive index dielectric layers, specific wavelength ranges can be achieved. It is known that it is possible to obtain a material that selectively reflects the rays of light.

In particular, a laminate that is transparent in the visible region and selectively reflects the infrared wavelength region is effective as a heat ray reflective film from the viewpoint of energy conservation in buildings, houses, etc., and solar energy utilization. However, in order to further improve energy saving efficiency in the field of energy saving in buildings, houses, etc. and solar energy blocking, it is necessary to
m ~ 700nm), near infrared region (701nm ~ 2100nm)
It is more effective to give more selectivity to the transmission characteristics of the filter. In other words, in the solar energy distribution, the transmission characteristics of the near-infrared region, which is invisible to the human eye but accounts for approximately 50% of the solar reflected heat rays, are further reduced, and the transmission characteristics of the visible light region are further improved. Since it is more effective in the field of view and does not impair transparency in any way, it can be applied to various fields without affecting the surrounding environment or safety.

Examples of application fields include improving the heat insulation of monitoring windows during high-temperature work, further improving the cooling effect by improving the ability to block solar energy that enters through the windows of buildings, cars, trains, and other vehicles, and heat blocking of transparent food containers. Improvements in performance and further improvement in the cold retention effect in frozen and refrigerated cases can be mentioned.

(b) Prior Art A well-known optical laminate having selective permeability is a laminate in which a metal thin film layer made of gold, silver, copper, etc. is sandwiched between transparent dielectric layers having a high refractive index. Such a laminate is transparent in the visible region and has the property of reflecting well from the near-infrared region to the infrared region.

In addition, heat-absorbing glass containing Fe oxide, which is known as a selectively transmitting material that is transparent in the visible light region and absorbs near-infrared light, has a visible light transmittance of 76% at a thickness of 5 mm, and is transparent to near-infrared light. It has a radiation transmittance of 57%.

In addition, in recent years, near-infrared light absorption filters containing organometallic complexes in an organic medium (Tokuko Showa) have been developed.
46-3452) or near-infrared light absorbing agricultural sheets (see Japanese Patent Laid-Open No. 49-31748).

(c) Problems However, in a laminate with a transparent dielectric layer/metal thin film layer/transparent dielectric layer structure, the optical properties are mostly determined by the properties of the metal thin film layer, and the absorption and transmission of the metal thin film layer The balance of reflection characteristics is controlled by the type of metal and film thickness. In such a structure, there is little room for selection of optical properties, and if you try to lower the near-infrared transmittance,
There is a tendency that the transmittance in the visible light region also decreases. For this reason, it has the disadvantage that there is very little room for selection of the optical properties that can be obtained.

In addition, in heat-absorbing glass, FeO and Fe ₂ O ₃ , which are oxides of Fe, have absorption not only in the near-infrared region but also in the visible region, which increases the absorption efficiency in the near-infrared region. When the color is improved, the absorption in the visible light region increases, the visible light transmittance decreases, and the visible light region becomes dark and colored.

A similar phenomenon is also observed in organometallic complexes that have absorption in the near-infrared region, and as expected, increasing the absorption effect in the near-infrared region decreases the visible light transmittance, making it darker and increasing the coloration. There were flaws.

(d) Means for solving the problem We have conducted intensive studies to find a way to apply a structure with better selective light transmittance to applications such as blocking solar energy, saving energy, and blocking harmful heat rays.

As a result, a Fabry-Perot optical interference filter having a metal thin film layer mainly composed of Ag metal laminated on an organic polymer film layer,
By optically combining a thin film layer containing a near-infrared absorber with an absorption peak between 800 nm and 1200 nm, it becomes possible to complementarily improve each other's shortcomings, and also to take advantage of each other's strengths. Synergistically increases the selectivity ratio of visible light and near-infrared light, which is transparent to visible light, reflects or absorbs most of near-infrared light, and reflects solar energy, or heat rays. The present invention was achieved by discovering that it is possible to produce a selectively transmitting light sheet with excellent blocking ability over a large area on an industrial scale. That is, the present invention provides a selectively transmitting sheet that transmits visible light and absorbs or reflects infrared rays, in which a metal layer with a thickness of 40 Å to 150 Å containing 50% by weight or more of Ag metal is made of an organic polymer with a refractive index of 1.35 or more. It has a first selective layer laminated on both sides of the transparent dielectric layer, and a second selective layer containing a near-infrared absorber having an absorption peak in the wavelength range of 800 nm to 1200 nm, and has optical properties that are integrally visible. Transmittance 70
% or more, and an integrated near-infrared transmittance of 50% or less.

The organic polymer film (D) serving as the substrate of the present invention does not need to be particularly limited, but for the purpose of applying the present invention by pasting it on a transparent window etc.
It is necessary to have transparency with a transmittance of at least 50% or less, preferably 75% or more, and any conventionally known organic polymer film (D) that satisfies this condition may be used. Among these, polyethylene terephthalate film, polycarbonate film, polypropylene film, polyethylene film, polyethylene naphthalate film, polysulfone film, polyethersulfone film, nylon film, etc. are preferably used.

The thickness of the organic polymer film (D) can be appropriately selected depending on the purpose, but from the viewpoint of flexibility, it is preferably from 10 μm to 200 μm. Furthermore, the present invention may include coloring agents, ultraviolet absorbers, stabilizers, plasticizers, pigments, etc., to the extent that these organic polymer films do not impair the mechanical properties and optical properties of the organic polymer films. There is no problem with the organic polymer film used.

The metal thin film layer (A) used in the present invention may be made of any metal or alloy as long as it has low absorption loss in the visible light region and has high electrical conductivity, but in particular, silver is the main component. is preferred. Other metals that can be contained include gold,
Copper, aluminum, etc. are preferred, but any metal may be included as long as it does not reduce the properties of silver. The content of silver is an important factor governing the optical properties of the selectively transparent sheet obtained, and it is preferably contained at least 50% by weight.

In addition, in order to obtain a light-selective transmitting sheet with particularly high infrared reflectivity, two elements selected from the three elements of gold, silver, and copper are used.
It is preferable that the metal thin film layer (A) is a metal thin film layer (A) of a metal or an alloy consisting of three metals, or a single metal thin film layer (A) of these metals.

The thickness of the metal thin film layer (A) is not particularly limited as long as it satisfies the required optical properties of the selectively transmitting light sheet to be obtained;
Alternatively, in order to have electrical conductivity, it is necessary to have continuity as a film in at least a certain area. The thickness for the metal thin film to change from an island-like structure to a continuous structure is approximately 40 Å or more, and in order to improve the visible light transmission characteristics, which is the objective of the present invention, the thickness is 150 Å.
It is preferable that it is below.

In order for the selectively transparent sheet to have sufficient visible light transmittance, the thickness of the metal thin film layer (A) is particularly preferably about 120 Å or less.

The metal thin film layer (A) can be formed by any conventionally known method such as vacuum evaporation, cathode sputtering, ion plating, etc., but it is stable at a film thickness of 150 Å or less. In order to form a film, cathode sputtering method,
A film forming method using high energy particles such as ion plating method is preferred. In particular, when obtaining an alloy thin film, the cathode sputtering method is preferred from the viewpoint of uniformity of the alloy composition of the formed thin film and uniformity of the thickness of the formed thin film.

Furthermore, in order to stabilize the thin metal layer when forming the metal thin film layer (A), the material that will become the substrate can be pretreated by a known method. These methods include, for example, cleaning treatments such as ion bombardment, undercoating treatments such as coating with organic silicates, organic titanates, organic zirconate compounds, and/or metals such as Ni, Ti, Si, Bi, Zr, V,
There is a nucleation stabilization treatment in which Ta and oxides of these metals are preformed by sputtering, etc., and these should be selected and used as long as they do not adversely affect the optical properties of the selectively transparent sheet. Just do it. If these pre-treatments involve an increase in thickness, the thickness is preferably 100 Å or less.
A treatment similar to this pre-treatment may be performed on the metal layer as a post-treatment.

The dielectric used for the transparent dielectric layer (B) of the present invention has a refractive index of 1.35 or more and is preferably a transparent organic polymer.

Such organic polymers include acrylate resins such as polymethyl methacrylate resin, acrylic resins such as polymethacrylonitrile and polyacrylonitrile, polystyrene resins, vinyl resins such as vinyl acetate, phenoxy resins, nylon resins, polyester resins, melamine resins, urethane resin,
Examples include epoxy resins and fluororesins.
Such organic polymers may be used singly or in the form of copolymers, or may be used with the addition of a crosslinking agent for crosslinking after coating.

The method for forming the transparent dielectric layer (B) is to dissolve the resin at an appropriate concentration in a solvent that dissolves the selected resin, and if the area is small, it can be coated using spin coating, a bar coater, a doctor knife, etc. It can be obtained by drying. In the case of a large area, a transparent dielectric layer (B) of any thickness can be formed by coating with a machine such as a gravure roll coater or a reverse roll coater and then drying. The drying temperature varies depending on the resin and solvent used, but is usually 80°C to 150°C.

The thickness of the transparent dielectric layer (B) is determined based on the relationship between the selectively transmitted wavelength and the resulting laminate of the transparent dielectric layer (B). In order to obtain a selectively transmitting light sheet, which is a laminate having maximum transmittance in the visible region,
The thickness of the transparent dielectric layer (B) is preferably between 500 Å and 1200 Å. In this way, the thickness of the transparent dielectric layer (B) may be appropriately determined depending on the desired optical characteristics.

The organic polymer used for the transparent dielectric layer (B) is preferably an organic polymer that is optically homogeneous and free from local turbidity, and when a layer with a thickness of 1 μm is formed, the organic polymer has a thickness of 500 nm.
It is preferable to transmit 85% or more of light having a wavelength of m.

Wavelength 800n, which is the second selective layer in the present invention
The thin film layer (C) containing a near-infrared absorber having an absorption peak between m and 1200 nm is formed from an organic resin layer containing a near-infrared absorber.

Examples of near-infrared absorbers include
Iron compounds such as FeO, Cu ion compounds such as copper sulfate,
Copper complexes such as copper phthalocyanine are known, but as near-infrared absorbers suitable for the present invention, the following general formula as seen in Japanese Patent Publication No. 1983-3452 is used. C: Carbon atom S: Sulfur atom R: Alkyl group M: Bis[cis-1,2-bis(alkyl)ethylene-1,2-dithiolate] metal complex compound represented by a metal atom, or J.Am, Chem. Soc 88 43 (1966)
The [bis(toluene-3,4-dithiol)] metal complex compound shown by HBGray et al. is preferably used. For example, Mitsui Toatsu Huain Co., Ltd.
Near-infrared absorber [IR ABSORBERPA-1001,
PA−1002, PA−1003, PA−1005, PA−1006〕
etc. can be easily used in the present invention.

In particular, [bis(1-methyl-3,4-dithiophenolate)nickel]tetrabutylammonium, [bis(1-methyl-3,4-dithiophenolate)platinum]tetrabutylammonium, [bis(1-methyl-3,4-dithiophenolate)platinum]tetrabutylammonium, chloro-3,4-dithiophenolate)nickel]tetrabutylammonium,
[Bis(1,2-dichloro-4,5 dithiophenolate)nickel]tetrabutylammonium,
[Bis(1,2,3,4tetrachloro-5,6 dithiophenolate)nickel] A dithiophenolate complex having a metal core of Ni, Pt, etc. such as tetrabutylammonium is preferably used in the present invention.

Such a near-infrared absorber is mixed into a solution of a suitable organic resin such as an acrylate resin, an acrylic resin, a urethane resin, a styrene resin, a polyester resin, a vinyl acetate resin, an acetal resin, or a copolymer composition thereof in a suitable solvent. Alternatively, by dissolving and coating, it is possible to form a thin film layer (C) containing a near-infrared absorber at an appropriate concentration to an arbitrary thickness.

In addition, if the near-infrared absorber is soluble in the organic polymer film (D) selected as the substrate, it can be mixed into the organic polymer film (D) by kneading or other methods. A film (D) can be the second selective layer. In this case, the thin film layer (C) containing the near-infrared absorber may be omitted.

In addition, an organic sheet containing a near-infrared absorber,
For example, it is also possible to laminate a polymethyl methacrylate resin plate or a polyvinyl chloride resin plate with an organic polymer film (D), and use the combination as an organic polymer film (D) as a substrate.

The concentration of the near-infrared absorber contained in the thin film layer (C) or the organic polymer (D) that becomes the second selective layer is 0.01 to 30 parts by weight [0.01 parts by weight] per 100 parts by weight of the resin used. phr (per hundred resin) to 30 phr], and it is necessary to select the appropriate concentration in relation to the compatibility with the organic resin used and the film thickness with the thin film layer (C). There is.

The thickness of the thin film layer (C) may be appropriately determined depending on the concentration of the near-infrared absorber contained, taking into consideration the effect of near-infrared absorbing ability. Considering the synergistic effect in the present invention, it is preferable that the near-infrared absorbent used at this time has a transmittance of 30% or less and 0.5% or more at the absorption peak (800 nm to 1200 nm).

Further, such a thin film layer (C) may contain a stabilizer, an ultraviolet absorber, an antioxidant, etc.

Furthermore, when stabilizers, ultraviolet absorbers, antioxidants, etc. interact with the near-infrared absorber, it is preferable to separate them and include them in other layers.

The selectively transmitting light sheet of the present invention has the following features: (1) excellent flexibility; and (2) optical uniformity over a large area.

(3) It is extremely bright with an integrated visible transmittance of 70% or more, and has excellent solar energy blocking properties with an integrated near-infrared transmittance of 50% or less.

Then, the selectively transmitting light sheet is made of the metal layer described above.
(A), the transparent dielectric layer (B), the thin film layer (C), and the organic polymer film (D) are the first selective layer with the layer configuration of (A)/(B)/(A) and the near-infrared rays. It is preferable that the layers be laminated in the following layer configuration so as to have a second selective layer containing an absorbent. That is, each of the above layers (A), (B), (C),
(D) is (C)/(D)/(A)/(B)/(A), or (C)/(D)/(A)/(
B)／
(A)/(B), or /(D)/(A)/(B)/(A)/(C), or/(D)
/
(A)／(B)／(A)／(B)／(C), or／(D)／(C)／(A)／(B)
/
It is preferable that the layers are laminated in the order of (A) or /(D)/(C)/(A)/(B)/(A)/(B).

Such selective light transmission functional sheets are used depending on their purpose, but for example, when used for building windows, etc., they can be applied directly to the glass of the window etc. with an adhesive, or they can be attached to the glass of the window etc. One possible method is to use it by spreading it between layers, and when it is used for windows of automobiles, it can be inserted into laminated glass known as safety glass through polyvinyl butyral.

In this case, an adhesion promoter, an adhesive, or a pressure-sensitive adhesive may be applied to the selectively transmitting light functional sheet of the present invention by a known method before use.

In particular, when the selective light transmission functional sheet of the present invention is used in safety glass for automobiles, vehicles, aircraft, buildings, etc., the synergy of the metal layer containing Ag, the antireflection layer, and the near-infrared absorber Due to the effect, the transmittance in the visible part is high, and the reflectance in the visible part is less than 15%,
It is preferably 12% or less, most preferably 10% or less, which is almost equivalent to glass, and it is possible to obtain a structure with excellent solar energy shielding rate.

By using the laminate of the present invention in this way,
It is possible to obtain various structures with excellent properties that are unattainable with the prior art.

In this way, the selective light transmission functional sheet of the present invention can be used in an optimal manner depending on the purpose of use, and can be effectively used not only in controlling the incidence of solar energy but also in all fields of heat radiation prevention. can do.

The optical performance of the present invention was measured with a self-recording spectrophotometer model 330 manufactured by Hitachi, Ltd., Asahi Glass Research Report, 1971, Volume 21, "On the calculation method of cooling load on window glass", Integrated ultraviolet transmittance 300-400 nm Calculated using integral visible transmittance of 450 to 700 nm and integral near-infrared transmittance of 750 to 2100 nm.

Moreover, in particular, the integral visible transmittance was also calculated by the JIS-R3212 method (400 to 760 nm), and the larger value obtained was adopted.

Examples of specific examples of the present invention will be described below. In addition, below, parts refer to parts by weight.

Example 1 A biaxially stretched polyethylene terephthalate film with a thickness of 50 μm is used as the substrate (D), and on one side thereof, a first layer as a first selective layer and a thickness as a third layer are formed.
60Å silver-copper alloy thin film layer (containing 10% copper by weight) (A)
A transparent dielectric layer (B) made of polystyrene with a thickness of 700 Å is sequentially laminated as a second layer, and a near-infrared absorber made of polystyrene with a thickness of 2 μ is layered on the other side as a second selective layer. (contains 10 phr of near-infrared absorber) thin film layer (C) laminated (C) / (D) / (A) /
A selectively transmitting light functional sheet having the configuration (B)/(A) was formed as follows.

The silver alloy thin film layer (A) containing 10% by weight of copper was formed by DC magnetron sputtering at an Ar gas pressure of 5×10 ^-3 Torr using a silver-copper alloy containing 10% by weight of copper as a target.

The input power is per unit area of the target.
It was 2W/ ^cm2 .

The transparent dielectric layer (B) made of polystyrene with a thickness of 700 Å contains 5 parts of toluene, 1 part of methyl ethyl ketone,
2% by weight of polystyrene was dissolved in a mixed solvent consisting of 1 part of ethyl acetate, coated with a bar coater, and dried. The thin film layer (C) containing a near-red absorber made of polystyrene is made by adding 10 phr of [bis(1-methyl-3,4 dithiophenolate)nickel]tetra-n-butylammonium to 10 parts of polystyrene, 7 parts of toluene, and ethyl acetate. A solution containing 10% by weight of polystyrene was prepared by dissolving it in a mixed solvent consisting of 3 parts. After coating with a bar coater, it was dried at 130°C for 2 minutes to form a 2μ thick thin film layer containing the near-infrared absorbent ( C) was formed.

The integrated visible transmittance (JIS-
R3212) had a 75% lamination near-infrared light transmittance of 34%.

Comparative Example 1 A film with a thickness of 2 μm was deposited on the polyethylene terephthalate film (D) used in Example 1 in the same manner as in Example 1.
Near-red absorber made of polystyrene [bis(1-methyl-3,4-dithiophenolate) nickel]
A thin film layer (C) containing tetra-n-butylammonium was formed.

The resulting laminate had an integrated visible transmittance of 85% and a near-infrared transmittance of 75%.

Comparative Example 2 On the polyethylene terephthalate film (D) used in Example 1, a silver-copper alloy metal thin film layer (containing 10% by weight of copper) with a thickness of 60 Å was applied as the first and third layers in the same manner as in Example 1. A transparent dielectric layer (B) made of polystyrene with a thickness of 700 Å was formed as a second layer from A).

The resulting laminate had an integrated visible transmittance of 76% and an integrated near-infrared light transmittance of 49%.

Example 2 On a biaxially stretched polyethylene terephthalate film (D) with a thickness of 75 μm, a pretreatment layer made of titanium metal with a thickness of 10 Å, a silver-copper alloy thin film layer containing 5% by weight of copper with a thickness of 55 Å, and a thickness of A first metal thin film layer (A) consisting of a post-treatment layer formed from metallic titanium with a thickness of 20 Å
The third layer is a transparent dielectric layer (B) made of polymethacrylonitrile with a thickness of 800 Å, the second layer is the first selective layer, and the fourth layer is the near-red absorber of the second selective layer. Light selective transmission function with (D)/(A)/(B)/(A)/(C) configuration made by sequentially laminating protective thin film layers (C) made of polymethacrylonitrile with a thickness of 5 μ and containing 10 phr of A plastic sheet was obtained as follows.

The silver-copper alloy thin film layer (A) containing 5% by weight of copper was formed in the same manner as in Example 1 by DC magnetron sputtering using the silver-copper alloy layer containing 5% by weight of copper as a target. The pre-treatment layer and post-treatment layer made of titanium metal were formed as thin films of titanium metal by RF magnetron sputtering using titanium metal as a target.

A transparent dielectric layer (B) made of polymethacrylonitrile having a thickness of 800 Å was obtained by applying a solution containing 5 parts of cyclohexanone and 2 parts of methyl ethyl ketone in which 2% by weight of polymethacrylonitrile was dissolved using a bar coater.

The protective thin film layer (C) is made of polymethacrylonitrile with a thickness of 5μ and contains 10 phr of a near-red absorber. A mixture of polymethacrylonitrile and a near-red absorber containing an amount of cyclohexanone
1 part by weight of polymethacrylonitrile in a solvent consisting of 4 parts of methyl ethyl ketone and 1 part of acetone.
The solution was dissolved and coated using a bar coater.

The resulting laminate had an integrated visible transmittance of 71% and an integrated near-infrared light transmittance of 28%.

Example 3 Same selective light transmittance as Example 1 except that the second transparent dielectric layer (B) of Example 1 was formed from a copolymer of methacrylonitrile/2-hydroxyethyl methacrylate instead of polystyrene. A sheet was formed. The transparent dielectric layer (B) made of a copolymer of methacrylonitrile and 2-hydroxyethyl methacrylate contains 90 parts of methacrylonitrile and 2
- 1 part of a copolymer formed from 10 parts of hydroxyethyl methacrylate and an isocyanate compound (adduct of trimethylolpropane and xylylene diisocyanate: trade name Takenate A-10,
(manufactured by Takeda Pharmaceutical Co., Ltd.) and 2% by weight of the above copolymer in a mixed solvent of cyclohexanone-acetone-methyl ethyl ketone (mixing ratio 5:2:1).
A solution dissolved at a concentration of 100 ml was applied using a bar coater and dried at 120° C. for 2 minutes to form a thin film layer in which the copolymer was crosslinked with the isocyanate compound.

The resulting laminate had an integrated visible transmittance of 74% and an integrated near-infrared transmittance of 35%.

Example 4 A polyvinyl butyral sheet having a thickness of 380 μm was laminated on both sides of the selectively transmitting sheet obtained in Example 2, and both sides were sandwiched with a glass plate having a thickness of 3 mm. The laminate was held at a temperature of 90° C. for 60 minutes while applying a pressure of 1 kg/cm ² to completely adhere, and then further treated under high temperature and high pressure conditions of 120° C. and 15 kg/cm ² . The integrated visible transmittance of the obtained laminate is 70%, and the near-infrared light transmittance is 25%.
%, and the integrated visible reflectance was 10%.

Example 5 On a polyethylene terephthalate film (D) with a thickness of 100 μm, a thin metal film layer (A) with a thickness of 60 Å consisting of a silver-gold metal layer (containing 15% by weight of gold) was applied as the first and third layers. A transparent dielectric layer (B) made of methyl methacrylate resin with a thickness of 650 Å is laminated as two layers, the first selective layer having a thickness containing 5 phr of the near-infrared absorber of the second selective layer as the fourth layer. A light-selective transmitting sheet with the configuration (D)/(A)/(B)/(A)/(C) made by sequentially laminating thin film layers (C) of 5 μm polymethacrylonitrile was prepared as follows. Obtained.

The silver-gold thin film layer (A) containing 15% gold by weight contains 15% gold by weight.
Using a silver-gold target containing % by weight, it was formed to a thickness of 60 Å by DC magnetron sputtering.
The transparent dielectric layer (B) made of methyl methacrylate resin with a thickness of 650 Å was coated using a bar coater with a solution consisting of 5 parts of toluene, 1 part of ethyl acetate, and 3 parts of methyl ethyl ketone in which 2% by weight of methyl methacrylate resin was dissolved. Obtained by drying. near red absorber
The thin film layer (C) made of polymethacrylonitrile with a thickness of 5 μm and containing 5phr is made of cyclohexanone 8 in which 15% by weight of polymethacrylonitrile is dissolved.
Tetrabutylammonium [bis(1 chlor-3,4 dithiophenolate) nickel] was dissolved in a solution consisting of 1 part by weight and 2 parts by weight of methyl ethyl ketone to give a concentration of 5 phr to polymethacrylonitrile, and coated with a bar coater at 120°C. It was obtained by drying for 3 minutes.

The resulting laminate had an integrated visible transmittance of 72% and an integrated near-infrared light transmittance of 32%.

Claims (1)

[Claims] 1. In a light-selective transmitting sheet that transmits visible light and absorbs or reflects infrared rays, Ag metal is
A first selective layer in which a metal layer with a thickness of 40 Å to 150 Å containing more than % by weight is laminated on both sides of a transparent dielectric layer made of an organic polymer with a refractive index of 1.35 or more, and a metal layer with a wavelength of 800 nm.
and a second selective layer containing a near-infrared absorber having an absorption peak between
% or less.