JP6207390B2 - Infrared shielding sheet and use thereof - Google Patents

Description

The present invention relates to a new infrared shielding sheet that efficiently absorbs and reflects infrared rays and has excellent transparency and low haze, and uses thereof.

In recent years, from the viewpoint of energy saving and global environmental problems, it has been demanded to reduce the load on air conditioning equipment. For example, in the field of houses and automobiles, it is required to lay an infrared shielding material capable of shielding infrared rays from sunlight on a window glass to control the temperature in a room or in a vehicle.

There are various materials having infrared shielding properties. However, in Patent Document 1, a dielectric multilayer film of a high refractive index layer and a low refractive index layer and a fine particle film such as ITO are laminated in order to reflect light having a specific wavelength in the infrared region. An insulated member is disclosed. Since this heat insulating member forms the dielectric multilayer film and the fine particle layer separately, there is a problem of manufacturing cost.

Patent Document 2 discloses a heat insulating member in which a transparent conductive layer and a high refractive index layer having a relatively high refractive index in the infrared region are laminated. However, since a conductive layer is used as a low refractive index layer in the infrared region, it cannot be used for systems that require radio wave transmission performance for transmitting and receiving radio waves indoors and outdoors, such as mobile phones, TVs, and GPS. There is. Furthermore, there is a problem of manufacturing cost because vacuum equipment such as sputtering is required.

International Publication No. 2007/020791 Pamphlet JP 2010-202465 A

An object of this invention is to provide the new infrared shielding sheet which improved the transparency in a visible light region, radio wave permeability, infrared shielding property, and manufacturing cost significantly.

As a result of intensive studies on such problems in the prior art, the present inventors have found that the high refractive index resin layer containing fine particles and the fine particles contained in the high refractive index resin layer in the infrared region are more relative to each other. In a laminated film in which a low refractive index resin layer containing fine particles having a low refractive index is laminated by coating, by optimizing the optical film thickness of each layer, it has transparency, radio wave transparency, and manufacturing cost. The present inventors have found that a new infrared shielding sheet having significantly improved infrared shielding properties is obtained, and have completed the present invention.

That is, the present invention comprises (1) a high refractive index resin layer (A) containing fine particles on a transparent support and fine particles, and has a lower refractive index than the layer (A) in the infrared region of 780 nm to 2500 nm. In the laminated film in which the refractive index resin layers (B) are alternately laminated, at least one of the low refractive index resin layers (B) has a value obtained by subtracting the refractive index at an arbitrary wavelength at 780 nm or more from the refractive index at 550 nm. 1. The QWOT coefficient of the optical film thickness of at least one high refractive index resin layer (A) and / or at least one low refractive index resin layer is 1.5 or more. Infrared shielding sheet,
(2) (A), (B) The infrared ray shielding sheet according to (1), wherein the surface resistance of each layer is 1 kΩ / □ or more, and the total number of layers of (A) and (B) is 4 or more,
(3) The infrared ray shielding sheet according to (1) or (2), wherein the visible light transmittance is 50% or more and the haze is 8% or less,
(4) Fine particles contained in the high refractive index resin layer (A) are titanium oxide, zirconium oxide, hafnium oxide, tantalum oxide, tungsten oxide, niobium oxide, cerium oxide, lead oxide, diamond, zinc oxide, boride, The infrared shielding sheet according to any one of (1) to (3), which is at least one kind of fine particles selected from the group consisting of nitrides,
(5) The fine particles contained in the low refractive index resin layer (B) are at least one kind of fine particles selected from the group consisting of tin oxide, indium oxide, zinc oxide, tungsten oxide, and silica (1) to (4). Infrared shielding sheet according to any one of
(6) Fine particles contained in the low refractive index resin layer (B) are Sb-doped tin oxide (ATO), Sn-doped indium oxide (ITO), Ga-doped zinc oxide (GZO), oxygen-deficient tungsten oxide, Cs-doped oxide. The infrared shielding sheet according to any one of (1) to (5), which is at least one selected from the group consisting of tungsten and hollow silica,
(7) The infrared shielding sheet according to any one of (1) to (6), wherein the content of fine particles contained in the high refractive index resin layer or the low refractive index resin layer is 90% by weight or less,
(8) The infrared shielding sheet according to any one of (1) to (7), wherein a high refractive index resin layer and a low refractive index resin layer are formed by coating;
(9) The infrared ray shielding sheet according to any one of (1) to (8) and a cholesteric liquid crystal film, a birefringent multilayer film, or a 780 nm to 2500 nm that selectively reflects 780 nm to 2000 nm An infrared shielding sheet formed by combining at least one of infrared absorbing pigments,
(10) An interlayer film for laminated glass having an interlayer film on the outermost layer of any one of the infrared shielding sheets according to any one of (1) to (9),
(11) The interlayer film for laminated glass according to (10), comprising polyvinyl butyral,
(12) Laminated glass obtained by inserting the interlayer film for laminated glass according to (10) or (11) between a plurality of glass plates,
(13) The infrared shielding sheet according to any one of (1) to (9) and the interlayer film for laminated glass according to (10) or (11), or the laminated glass according to (12) are laminated. Window member obtained by
About.

The infrared shielding sheet of the present invention has a reflection property in addition to a good absorption property for a wide infrared region, is excellent in radio wave transmission, transparency and manufacturing cost, has low haze, and has an infrared shielding effect. Therefore, both the effect of reducing the heating cost in winter and the effect of reducing the temperature in summer can be improved.

It is a graph which shows the transmittance | permeability and reflectance with respect to the wavelength of the infrared shielding sheet which concerns on Example 1 of this invention, and the energy of the sunlight which reaches | attains the ground surface. It is a graph which shows the refractive index and reflectance with respect to the wavelength of the infrared shielding sheet which concerns on the comparative example of this invention. It is sectional drawing which shows typically an example of the intermediate film for laminated glasses which concerns on embodiment of this invention. It is sectional drawing which shows typically an example of the laminated glass using the intermediate film for laminated glasses shown in FIG.

The infrared shielding sheet of the present invention contains a high refractive index resin layer (A) containing fine particles on a transparent support and fine particles, and has a lower refractive index than the layer (A) in the infrared region of 780 nm to 2500 nm. In the laminated film in which the refractive index resin layers (B) are alternately laminated, at least one of the low refractive index resin layers (B) has a value obtained by subtracting the refractive index at an arbitrary wavelength at 780 nm or more from the refractive index at 550 nm. 1. The QWOT coefficient of the optical film thickness of at least one high refractive index resin layer (A) and / or at least one low refractive index resin layer is 1.5 or more. Features. In addition, the infrared region in this invention shows a thing of 780 nm-2500 nm.

As the transparent support used in the present invention, various resin films and glass can be used, polyolefin film (polyethylene, polypropylene, etc.), polyester film (polyethylene terephthalate (hereinafter referred to as PET), polybutylene terephthalate, polyethylene naphthalate. (Hereinafter referred to as PEN), polycarbonate (hereinafter referred to as PC), polyvinyl chloride, cellulose triacetate, polyamide, polyimide, and the like can be used.

Infrared shielding sheet made by alternately laminating high refractive index resin layer and low refractive index resin layer is the infrared reflection function with both refractive index difference in infrared region and absolute value of refractive index of high refractive index resin layer It is important to decide. That is, the infrared reflection function becomes larger as the refractive index difference and the absolute value of the refractive index are larger.

In the present invention, a difference in refractive index between at least two adjacent layers (a high refractive index resin layer and a low refractive index resin layer) is 0.1 or more at an infrared wavelength to be reflected. Preferably it is 0.3 or more, More preferably, it is 0.35 or more.

If the difference in refractive index is less than 0.2, the number of laminated layers is increased to make the infrared reflectance a desired value, the visible transmittance is reduced, and the production cost is increased, which is not preferable.

The infrared wavelength λ to be reflected is generally given by equation (1). n _H and d _H are the refractive index and geometric film thickness of the high refractive index resin layer, and n _L and d _L are the refractive index and geometric film thickness of the low refractive index resin layer.
Formula (1)
_{n H d H + n L d} L = λ / 2

Here, as shown in FIG. 1, the infrared region of sunlight that reaches the earth's surface has several mountains of energy, and when it is desired to shield the infrared region of sunlight, it is possible to effectively shield these mountains of energy. It becomes important. As a result of intensive studies, the infrared region of sunlight is effectively blocked by increasing the QWOT coefficient of the optical film thickness of at least one of the high refractive index resin layer and the low refractive index resin layer to 1.5 or more. I found out that I can do it. Here, a QWOT (quarter wave optical thickness) coefficient is set to 1 when nd = λ / 4. n and d are the refractive index of the high refractive index resin layer or the low refractive index resin layer, the geometric film thickness, and λ is the infrared wavelength to be reflected.

The infrared wavelength to be reflected is preferably 780 nm or more. If it is less than 780 nm, the visible light transmittance is lowered because it is in the visible light region, which is not preferable.

The number of layers of the infrared shielding sheet of the present invention is preferably 4 to 30 layers, more preferably 4 to 20 layers, and particularly preferably 4 to 15 layers. If the number of layers of the multilayer film is less than 4, the infrared reflection function is insufficient, and if it exceeds 30 layers, the manufacturing cost increases, the visible light transmittance, the durability decreases, and the curl of the film due to an increase in film stress. Is not preferable because it becomes a problem.

The ideal optical performance of the infrared shielding sheet is that it has a high visible light transmittance and a low solar transmittance, but generally there is a proportional relationship between them, and the optical performance depends on which performance is important. Will be determined. As a result of various studies, the visible light transmittance of the infrared shielding sheet of the present invention is 50% or more, preferably 70% or more, in order to minimize the increase in lighting cost and winter heating cost. Furthermore, the haze value of the infrared shielding sheet needs to be such that transparency is not impaired, and should be 8% or less, preferably 3% or less.

In the case of producing a multilayer film using the difference in refractive index by coating, in the conventional technique, a high refractive index resin layer contains dielectric fine particles (such as titanium oxide) having a high refractive index, and the low refractive index resin layer has a refractive index. Low dielectric fine particles (silica or the like) were contained (for example, JP 2012-93481 A). The refractive index of the dielectric fine particles in the visible light region to the infrared region is substantially constant.

However, as a result of intensive studies, the present inventors have discovered a group of fine particles having a refractive index in the visible light region and a refractive index in the infrared region, and further have an infrared absorption capability. It was found that the infrared region can be shielded more efficiently by combining the dielectric fine particle groups.

The high refractive index resin layer containing fine particles preferably has a value obtained by subtracting the refractive index at an arbitrary wavelength of 780 nm or more from the refractive index at 550 nm of 0.1 or less. In addition, at least one low refractive index resin layer has a refractive index at 550 nm minus a refractive index at an arbitrary wavelength at 780 nm or more, which is 0.1 or more, and has a low refractive index in the difference wavelength region. The refractive index of the refractive index resin layer is preferably lower than that of the high refractive index resin layer.

The fine particles contained in the high refractive index resin layer satisfying the above conditions are suitably fine particles that absorb less in the visible light region and exhibit a high refractive index in the infrared region. Examples of such fine particles include dielectric fine particles such as titanium oxide, zirconium oxide, hafnium oxide, tantalum oxide, tungsten oxide, niobium oxide, cerium oxide, lead oxide, zinc oxide, and diamond. Of these, titanium oxide, zirconium oxide, zinc oxide, and diamond are preferable. Further, although not the dielectric fine particles, borides and nitrides can be exemplified as electrically conductive metal oxide fine particles having a high refractive index in the infrared region and having infrared absorption ability. Specifically, lanthanum hexaboride and titanium nitride are suitable.

These fine particles exhibiting a high refractive index in the infrared region may be used singly or in combination of two or more, and separate fine particles may be used in each high refractive index resin layer in the laminated film.

The content of fine particles in the high refractive index resin layer is 40 to 95% by weight, preferably 60 to 90% by weight, more preferably 70 to 90% by weight. If it exceeds 95% by weight, the binder component decreases, and it becomes impossible to produce a sheet. On the other hand, if the amount is less than 40% by weight, the refractive index of the resin binder becomes dominant and the infrared region cannot be effectively reflected.

Further, the fine particles contained in at least one low refractive index resin layer have less absorption in the visible light region, have good absorption in the infrared region, and have a higher refractive index than the fine particles containing the high refractive index resin layer. Those having a particularly low refractive index are suitable. As such, there may be mentioned electrically conductive metal oxide fine particles having a plasma wavelength in the infrared region. Specific examples include tin oxide, indium oxide, zinc oxide, tungsten oxide, chromium oxide, and molybdenum oxide. Among these, tin oxide, indium oxide, zinc oxide, and tungsten oxide having a low light absorption property in the visible light region are preferable, and indium oxide is more preferable among them.

Moreover, it is preferable to dope the third component in order to improve the electrical conductivity of these metal oxide fine particles. Examples of dopants for this include Sb, V, Nb, Ta, etc. for tin oxide, and Zn, Al, Sn, Sb, Ga, Ge, etc. for indium oxide. On the other hand, Al, Ga, In, Sn, Sb, Nb and the like can be mentioned. For tungsten oxide, Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, Sn, Al, Cu etc. are mentioned. Among these, Sn-doped indium oxide is preferable. It is also preferable to make the third component oxygen deficient in order to improve the electrical conductivity of these metal oxide fine particles. Examples of oxygen defects for this purpose include oxygen defects WO _x (where 2.45 ≦ x ≦ 2.999) with respect to tungsten oxide.

Further, as the metal oxide fine particles, fine particles having a powder resistance of 100 Ω · cm or less, preferably 10 Ω · cm or less, more preferably 1 Ω · cm or less when compressed at 60 MPa are used. When fine particles having a powder resistance higher than 100 Ω · cm are used, the absorption due to the plasma resonance of the fine particles is larger than 2500 nm, and the infrared shielding effect is reduced. As a method for measuring powder resistance, a powder resistance measurement system MCP-PD51 (Mitsubishi Chemical Analytech) is preferable, but is not limited thereto.

In addition to electrically conductive metal oxide fine particles (hereinafter referred to as electrically conductive fine particles), low refractive index dielectric fine particles can be used for the low refractive index resin layer. As the dielectric fine particles, silica, magnesium fluoride, or the like can be used.

Further, hollow fine particles can be used as the dielectric fine particles having a low refractive index. Examples of the hollow fine particles include hollow fine particles such as hollow silica and hollow acrylic beads. The porosity of the hollow fine particles is preferably 10% to 90% by volume. When the porosity is less than 10% by volume, the refractive index of the hollow fine particles does not decrease and cannot be used for the low refractive index resin layer. On the other hand, when the porosity is higher than 90% by volume, the mechanical strength of the hollow particles decreases, and the hollow cannot be maintained, which is not preferable.

The fine particles (electrically conductive fine particles, dielectric fine particles, hollow fine particles) used for the low refractive index resin layer may be used alone or in combination of two or more kinds. Further, separate fine particles are used in each low refractive index resin layer in the laminated film. You may use.

The content of fine particles in the low refractive index resin layer is 40 to 95% by weight, preferably 60 to 90% by weight, more preferably 70 to 90% by weight. If it exceeds 95% by weight, the binder component decreases, so that it cannot be produced in a sheet form, and the fine particles are connected to each other, so that radio wave transmission performance cannot be imparted. If it is less than 40% by weight, the refractive index of the resin binder becomes dominant, and the infrared region cannot be effectively reflected.

When electrically conductive fine particles and dielectric fine particles or hollow fine particles are combined with the low refractive index resin layer, the proportion of the electrically conductive fine particles in the low refractive index resin layer is preferably 10% by weight to 90% by weight. More preferably, it is 20 to 90% by weight. When the amount of the electrically conductive fine particles is less than 10% by weight, the infrared absorbing ability by the metal oxide is insufficient, which is not preferable. When the amount is more than 90% by weight, the proportion of hollow fine particles decreases, which is not preferable.

Further, fine particles used in the infrared shielding sheet of the present invention are those having a primary particle diameter of 300 nm or less, preferably 1 nm to 200 nm. When the primary particle diameter is larger than 300 nm, when an infrared shielding sheet is used, the haze value is increased and the visibility is deteriorated. The particle size is calculated from the specific surface area measured by the BET method.

In order to satisfy the infrared shielding performance, smoothness, low haze, and radio wave permeability of the infrared shielding sheet, it is important to appropriately disperse the fine particles. As a dispersion method, it is preferable to use a sand mill, an attritor, a ball mill, a homogenizer, a roll mill, or a bead mill. Among these, a bead mill is particularly preferable. When a bead mill is used, the peripheral speed is preferably 3 m / s to 10 m / s. If it is lower than 3 m / s, the fine particles cannot be sufficiently dispersed. If it is higher than 10 m / s, the surface of the electrically conductive fine particles contained in the low refractive index resin layer is particularly damaged, and the infrared absorption performance is lowered. The appropriate range varies slightly depending on the apparatus used, the binder, the fine particle concentration at the time of dispersion, etc., but it is better to disperse with a relatively low dispersion energy. Furthermore, when coarse particles remain, it is preferable to remove the coarse particles by a treatment such as filtration or centrifugation.

The solvent used for dispersion is not particularly limited, but in the present invention, water or an organic solvent may be blended and used as a mixture. Examples of the organic solvent include hydrocarbon solvents (toluene, xylene, hexane, cyclohexane, n-heptane, etc.), alcohol solvents (methanol, ethanol, isopropyl alcohol, butanol, t-butanol, benzyl alcohol, etc.), ketone solvents. (Acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, acetylacetone, etc.), ester solvents (ethyl acetate, methyl acetate, butyl acetate, cellosolve acetate, amyl acetate, etc.), ether solvents (isopropyl ether, methyl cellosolve, butyl cellosolve) 1,4-dioxane, etc.), glycol solvents (ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, etc.), glycol ether solvents Diethylene glycol monomethyl ether, propylene glycol monomethyl ether, etc.), glycol ester solvents (ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, etc.), glyme solvents (monoglyme, diglyme, etc.), halogenated solvents ( Dichloromethane, chloroform, etc.), amide solvents (N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone), pyridine, tetrahydrofuran, sulfolane, acetonitrile, dimethyl sulfoxide. Preferred are water, ketone solvents, alcohol solvents, amide solvents, and hydrocarbon solvents, and more preferred are toluene, methyl ethyl ketone, methyl isobutyl ketone, and acetylacetone.

Dispersants include fatty acid salts (soap), α-sulfo fatty acid ester salts (MES), alkylbenzene sulfonates (ABS), linear alkylbenzene sulfonates (LAS), alkyl sulfates (AS), alkyl ether sulfates Low molecular weight anionic (anionic) compounds such as salt (AES) and alkyl sulfate triethanol, fatty acid ethanolamide, polyoxyethylene alkyl ether (AE), polyoxyethylene alkylphenyl ether (APE), sorbitol, sorbitan Nonionic compounds, low molecular weight cationic (cationic) compounds such as alkyltrimethylammonium salt, dialkyldimethylammonium chloride, alkylpyridinium chloride, alkylcarboxyl betaine, sulfobetatai Low molecular amphoteric compounds such as lecithin, formalin condensate of naphthalene sulfonate, polystyrene sulfonate, polyacrylate, copolymer salt of vinyl compound and carboxylic acid monomer, carboxymethyl cellulose, polyvinyl alcohol, etc. Typical examples are polymeric water-based dispersants such as polyacrylic acid partial alkyl esters and polyalkylene polyamines, and polymer cationic dispersants such as polyethyleneimine and aminoalkyl methacrylate copolymers. However, as long as it is suitably applied to the particles of the present invention, those having a structure other than the ones exemplified here are not excluded.

The following are known as specific dispersants to be added. Florene DOPA-15B, Floren DOPA-17 (manufactured by Kyoeisha Chemical Co., Ltd.), Solplus AX5, Solplus TX5, Solsperse 9000, Solsperse 12000, Solsperse 17000, Solsperse 20000, Solsperse 21000, Solsperse 24000, Solsperse 26000, Solsperse 27000, Solsperse 28000, Solsperse 32000, Solsperse 35100, Solsperse 54000, Sol Six 250, (manufactured by Nippon Lubrizol Corporation), EFKA4008, EFKA4009, EFKA4010, EFKA4015, EFKA4046, EFKA4047, EFKA4060, EFKA7440E, EFKA7440E EFKA4400, EFKA4401, EFKA4402, EFKA4403, EFKA4300, EFKA4320, EFKA4330, EFKA4340, EFKA6220, EFKA6225, EFKA6700, EFKA6780, EFKA8583, EFKA8583 PN411, Famex L-12 (manufactured by Ajinomoto Fine Techno Co., Ltd.), TEXAPHOR-UV21, TEXAPHOR-UV61 (manufactured by Cognis Japan Co., Ltd.), DisperBYK101, DisperBYK102, DisperBYK106, DisperBYK108, DisperBYK111 DisperBYK116, DisperBYK130, DisperBYK140, DisperBYK142, DisperBYK145, DisperBYK161, DisperBYK162, DisperBYK163, DisperBYK164, DisperBYK166, DisperBYK167, DisperBYK168, DisperBYK170, DisperBYK171, DisperBYK174, DisperBYK180, DisperBYK182, DisperBYK192, DisperBYK193, DisperBYK2000, DisperBYK2001, DisperBYK2020, DisperBYK2025, DisperBYK2050, DisperBYK2070, Di SuperBYK2155, DisperBYK2164, BYK220S, BYK300, BYK306, BYK320, BYK322, BYK325, BYK330, BYK340, BYK350, BYK377, BYK378, BYK380N, BYK410, BYK410, BYK410, BYK410, BYK410 , Disparon 1860, Disparon 1934, Disparon DA-400N, Disparon DA-703-50, Disparon DA-725, Disparon DA-705, Disparon DA-7301, Disparon DN-900, Disparon NS-5210, Disparon NVI-8514L, Hip LARD ED-152, Plard ED-216, Hiplard ED-251, Hiplard ED-360 (Enomoto Kasei Co., Ltd.), FTX-207S, FTX-212P, FTX-220P, FTX-220S, FTX-228P, FTX-710LL, FTX-750LL , Aftergent 212P, aftergent 220P, aftergent 222F, aftergent 228P, aftergent 245F, aftergent 245P, aftergent 250, aftergent 251, aftergent 710FM, aftergent 730FM, aftergent 730LL, aftergent 730LS, after Gento 750DM, Aftergent 750FM (manufactured by Neos Co., Ltd.), AS-1100, AS-1800, AS-2000 (manufactured by Toagosei Co., Ltd.), Kao Sera 2000, Kaosela 2100, KDH-154, MX-2045L, Homogenol L-18, Homogenol L-95, Rheodor SP-010V, Rheodor SP-030V, Rheodor SP-L10, Rheodor SP-P10 (manufactured by Kao Corporation), Evan U103, Cyanol DC902B, Neugen EA-167, Blysurf A219B, Blysurf AL (Daiichi Kogyo Seiyaku Co., Ltd.), MegaFuck F-477, MegaFuck 480SF, MegaFuck F-482 (Dic Corporation) , Sylface SAG503A, Dinol 604 (Nisshin Chemical Co., Ltd.), SN Spurs 2180, SN Spurs 2190, SN Leveler S-906 (San Nopco), S-386, S-420 (AGC Seimi Chemical Co., Ltd.) (Made by company).

The resin binder used in the present invention is not particularly limited as long as it can disperse and maintain fine particles, and examples thereof include thermoplastic resins, thermosetting resins, and photocurable resins.

The thermoplastic resins include high density polyethylene resin, low density polyethylene resin, linear low density polyethylene resin, ultra low density polyethylene resin, polypropylene resin, polybutadiene resin, cyclic olefin resin, polymethylpentene resin, polystyrene resin, ethylene acetate Vinyl copolymer, ionomer resin, ethylene vinyl alcohol copolymer resin, ethylene ethyl acrylate copolymer, acrylonitrile / styrene resin, acrylonitrile / chlorinated polystyrene / styrene copolymer resin, acrylonitrile / acrylic rubber / styrene copolymer resin, acrylonitrile / butadiene・ Styrene copolymer resin, acrylonitrile, EPDM, styrene copolymer resin, silicone rubber, acrylonitrile, styrene copolymer resin, cellulose, acetate, Rate resin, cellulose acetate resin, methacrylic resin, ethylene / methyl methacrylate copolymer resin, ethylene / ethyl acrylate resin, vinyl chloride resin, chlorinated polyethylene resin, polytetrafluoroethylene resin, tetrafluoroethylene / hexafluoropropylene copolymer Resin, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin, tetrafluoroethylene / ethylene copolymer resin, polytrifluorinated ethylene chloride resin, polyvinylidene fluoride resin, nylon 4, 6, nylon 6, nylon 6, 6 , Nylon 6, 10, nylon 6, 12, nylon 12, nylon 6, T, nylon 9, T, aromatic nylon resin, polyacetal resin, ultrahigh molecular weight polyethylene resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyester Lena naphthalate resin, amorphous copolyester resin, polycarbonate resin, modified polyphenylene ether resin, thermoplastic polyurethane elastomer, polyphenylene sulfide resin, polyether ether ketone resin, liquid crystal polymer, polytetrafluoroethylene resin, polyfluoroalkoxy resin, polyether Examples include, but are not limited to, imide resins, polysulfone resins, polyketone resins, thermoplastic polyimide resins, polyamideimide resins, polyarylate resins, polysulfone resins, polyethersulfone resins, biodegradable resins, and biomass resins. . Also, a mixture of two or more of these resins may be used.

The thermosetting resin is not particularly limited as long as it has a functional group curable by heating, and examples thereof include a curable compound having a cyclic ether such as an epoxy group or an oxetanyl group. The photocurable resin is not particularly limited as long as it is a compound having a functional group that can be cured by light irradiation. For example, a vinyl group, vinyl ether group, allyl group, maleimide group, (meth) acryl group, etc. Examples thereof include resins having a curable compound having a saturated double bond.

It does not specifically limit as a thermosetting resin which has the said cyclic ether, For example, an epoxy resin, an alicyclic epoxy resin, an oxetane resin, a furan resin etc. are mentioned. Of these, epoxy resins, alicyclic epoxy resins, and oxetane resins are preferred from the viewpoint of reaction rate and versatility. The epoxy resin is not particularly limited, and examples thereof include novolak types such as phenol novolak type, cresol novolak type, biphenyl novolak type, trisphenol novolak type, dicyclopentadiene novolak type; bisphenol A type, bisphenol F type, 2, 2 Examples thereof include bisphenol types such as' -diallyl bisphenol A type, hydrogenated bisphenol type, and polyoxypropylene bisphenol A type. Other examples include glycidylamine.

As a commercially available product of the above epoxy resin, for example, as a phenol novolak type epoxy resin, Epicron N-740, N-770, N-775 (all of which are manufactured by Dainippon Ink and Chemicals), Epicoat 152, Epicoat 154 ( As mentioned above, all are Japan Epoxy Resin Co., Ltd.). Examples of the cresol novolac type include epiclone N-660, N-665, N-670, N-673, N-680, N-695, N-665-EXP, N-672-EXP (all of which are large. As a biphenyl novolak type, for example, NC-3000P (manufactured by Nippon Kayaku Co., Ltd.); As a trisphenol novolak type, for example, EP1032S50, EP1032H60 (all of these are manufactured by Japan Epoxy Resin); Examples of the dicyclopentadiene novolak type include XD-1000-L (manufactured by Nippon Kayaku Co., Ltd.), HP-7200 (manufactured by Dainippon Ink and Chemicals); Epicoat 1001, Epicoat 1004 (above, Izu Are manufactured by Japan Epoxy Resin Co., Ltd.), Epicron 850, Epicron 860, Epicron 4055 (all of which are manufactured by Dainippon Ink & Chemicals, Inc.); Commercially available bisphenol F type epoxy compounds include, for example, Epicoat 807 (Japan Epoxy Resin Co., Ltd.) ), Epicron 830 (Dainippon Ink Chemical Co., Ltd.); 2,2′-diallyl bisphenol A type, for example, RE-810NM (Nippon Kayaku Co., Ltd.); Hydrogenated bisphenol type, for example, ST -5080 (manufactured by Tohto Kasei Co., Ltd.); Examples of the polyoxypropylene bisphenol A type include EP-4000 and EP-4005 (all of which are manufactured by Asahi Denka Kogyo Co., Ltd.).

Examples of commercially available oxetane compounds include etanacol EHO, etanacol OXBP, etanacol OXTP, etanacol OXMA (all of which are manufactured by Ube Industries, Ltd.). Moreover, it does not specifically limit as said alicyclic epoxy compound, For example, Celoxide 2021, Celoxide 2080, Celoxide 3000 (all are the Daicel UCB company make) etc. are mentioned. These curable compounds having a cyclic ether group may be used alone or in combination of two or more.

The photocurable resin having an unsaturated double bond is not particularly limited, and examples thereof include resins having a vinyl group, a vinyl ether group, an allyl group, a maleimide group, a (meth) acryl group, and the like. From the viewpoint of versatility, a resin having a (meth) acryl group is preferred. In addition, in this specification, a (meth) acryl group means an acryl group or a methacryl group.

Examples of the resin having a (meth) acryl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 1,4-butanediol mono (meth) acrylate, carbitol (meth) acrylate, and acryloyl. Morpholine, half ester which is a reaction product of hydroxyl group-containing (meth) acrylate and acid anhydride of polycarboxylic acid compound, polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate , Di (meth) acrylate of ε-caprolactone adduct of trimethylolpropane polyethoxytri (meth) acrylate, glycerin polypropoxytri (meth) acrylate, and neopentyl glycol hydroxypivalate (For example, KAYARAD HX-220, HX-620, etc., manufactured by Nippon Kayaku Co., Ltd.), pentaerythritol tetra (meth) acrylate, poly (meth) acrylate, dipentaerythritol and ε-caprolactone reaction product, dipenta Examples include erythritol poly (meth) acrylate (for example, KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd.), epoxy (meth) acrylate that is a reaction product of a mono- or polyglycidyl compound and (meth) acrylic acid, and the like.

There is no restriction | limiting in particular as a glycidyl compound used for the epoxy (meth) acrylate which is a reaction material of a mono- or polyglycidyl compound and (meth) acrylic acid, For example, bisphenol A, bisphenol F, bisphenol S, 4, 4'- Biphenylphenol, tetramethylbisphenol A, dimethylbisphenol A, tetramethylbisphenol F, dimethylbisphenol F, tetramethylbisphenol S, dimethylbisphenol S, tetramethyl-4,4'-biphenol, dimethyl-4,4'-biphenylphenol, 1- (4-hydroxyphenyl) -2- [4- (1,1-bis- (4-hydroxyphenyl) ethyl) phenyl] propane, 2,2′-methylene-bis (4-methyl-6-tert- Butylphenol 4,4'-butylidene-bis (3-methyl-6-tert-butylphenol), trishydroxyphenylmethane, resorcinol, hydroquinone, pyrogallol, phenols having a diisopropylidene skeleton, 1,1-di-4-hydroxy Phenols having a fluorene skeleton such as phenylfluorene, phenolized polybutadiene, brominated bisphenol A, brominated bisphenol F, brominated bisphenol S, brominated phenol novolac, brominated cresol novolac, chlorinated bisphenol S, chlorinated bisphenol A, etc. And glycidyl etherified products of polyphenols.

The epoxy (meth) acrylate which is a reaction product of these mono- or polyglycidyl compounds and (meth) acrylic acid can be obtained by esterifying an equivalent amount of (meth) acrylic acid to the epoxy group. This synthesis reaction can be performed by a generally known method. For example, resorcin diglycidyl ether with an equivalent amount of (meth) acrylic acid, a catalyst (for example, benzyldimethylamine, triethylamine, benzyltrimethylammonium chloride, triphenylphosphine, triphenylstibine, etc.) and a polymerization inhibitor (for example, methoquinone, Hydroquinone, methylhydroquinone, phenothiazine, dibutylhydroxytoluene and the like) and, for example, an esterification reaction is performed at 80 ° C to 110 ° C. The (meth) acrylated resorcin diglycidyl ether thus obtained is a resin having a radically polymerizable (meth) acryloyl group.

Moreover, the resin binder of the infrared shielding sheet of this invention can add a photoreaction initiator and a thermosetting agent as needed. The photoinitiator is not particularly limited as long as it is for polymerizing an unsaturated double bond or an epoxy group in the curable resin by light irradiation. For example, a cationic polymerization type photoinitiator or a radical is used. A polymerization type photoinitiator is mentioned. The thermosetting agent is not particularly limited as long as it is for reacting and crosslinking the unsaturated double bond or epoxy group in the curable resin by heating. For example, acid anhydride, amines, phenol Imidazoles, dihydrazines, Lewis acids, Bronsted acid salts, polymercaptons, isocyanates, blocked isocyanates and the like.

The content of fine particles in each layer in the infrared shielding sheet is 40% to 95% by weight, preferably 50% to 90% by weight, more preferably 60% to 90% by weight. If it exceeds 95% by weight, the binder component decreases, so that the film is not cured and it becomes difficult to laminate. Furthermore, in the case of electrically conductive fine particles, the fine particles are connected to each other, so that radio wave transmission performance cannot be imparted. On the other hand, when the amount is less than 40% by weight, the refractive index of the resin binder is dominant and the infrared reflection performance cannot be imparted.

In the present invention, the surface resistance of the high refractive index resin layer and the low refractive index resin layer is 10 ³ Ω / □ or more, preferably 10 ⁴ Ω / □ or more, more preferably 10 ⁶ Ω / □ or more. If it is lower than 10 ³ Ω / □, radio waves cannot be transmitted, which is not preferable.

Further, the maximum height difference of the surface of each layer is 70 nm or less, preferably 60 nm or less, more preferably 50 nm or less. When thin film coating is performed after dispersing until the aggregated fine particles disappear, a preferable maximum height difference on the surface of the fine particle layer can be obtained. On the other hand, if there is a surface roughness of 70 nm or more, near-infrared light incident on the film surface will scatter, and good reflection performance cannot be imparted.

The infrared shielding sheet of the present invention is preferably produced by appropriately selecting a high refractive index resin layer and a low refractive index resin layer from known coating methods and applying and drying on a support. Although it does not specifically limit about a coating system, A comma coater, a spray coater, a roll coater, a knife coater, etc. are mentioned, but thin film production such as a bar coater, a spin coater, a die coater, a micro gravure coater is preferable for the smoothness of each layer. Use a coating device suitable for

Moreover, various additives, such as a ultraviolet absorber, antioxidant, a light stabilizer, can be added to an infrared shielding sheet or a new layer as needed, for example. Furthermore, depending on the purpose, functional sheets such as an adhesive layer and a hard coat layer may be laminated on the infrared shielding sheet to form an infrared shielding laminated sheet.

For the infrared region that cannot be shielded by the infrared shielding sheet of the present invention, known materials such as an infrared absorbing dye, a cholesteric liquid crystal film, and a birefringent multilayer film may be combined.

The infrared absorbing dye to be combined with the infrared shielding sheet of the present invention is not particularly limited, but specifically, an infrared absorbing dye having an absorption maximum at 700 nm to 2500 nm, preferably an infrared having an absorption maximum at 750 to 1500 nm. Absorbing dyes, more preferably infrared absorbing dyes having an absorption maximum at 780 to 1100 nm. For example, phthalocyanine dyes, anthraquinone dyes, dithiol dyes, diimonium dyes, anthraquinone dyes, dithiol metal complex dyes, squarylium dyes, naphthalocyanine dyes, aminium dyes, organometallic complex dyes, cyanine dyes Dyes, azo dyes, polymethine dyes, quinone dyes, diphenylmethane dyes, triphenylmethane dyes, and mercaptonaphthol dyes can be used.

Among these, phthalocyanine dyes, naphthalocyanine dyes, and anthraquinone dyes are preferably used.

The infrared absorbing dye may be contained in each of the high refractive index resin layer and the low refractive index resin layer, or a layer containing the infrared absorbing dye may be newly provided.

In the cholesteric liquid crystal film combined with the infrared shielding sheet of the present invention, the molecular axes are aligned in a certain direction on one plane, but the molecular axes are shifted slightly from each other on the next plane, and further on the next plane. In this structure, the angles of the molecular axes are shifted one after another in the normal direction of the plane such that the angles are shifted. Such a structure in which the direction of the molecular axis is twisted is called a chiral structure. The normal line (chiral axis) of the plane is preferably substantially parallel to the thickness direction of the cholesteric liquid crystal layer.

When light is incident on the cholesteric liquid crystal material, one of the circularly polarized light in the left-handed and right-handed directions in the specific wavelength region is reflected. When the helical axis representing the rotation axis when the molecular axis is twisted in the chiral structure and the normal line of the cholesteric liquid crystal material are parallel, the pitch length p of the chiral structure and the wavelength λ _{c of the} circularly polarized light reflected are as follows: It has the relationship of (2) and Formula (3).
Formula (2)
Formula (3)
In the formula (2) and (3), lambda _c is the center wavelength of the wavelength region to be reflected, n _o is the minor axis direction of the refractive index of the liquid crystal compounds, n _e is the refractive index of the long axis of the liquid crystal compounds, n (N _o + n _e ) / 2, θ represents the incident angle of light (angle from the surface normal).

Thus, the center wavelength of the wavelength region to be reflected depends on the pitch length of the chiral structure in the cholesteric liquid crystal material. The central wavelength to be reflected can be changed by changing the pitch length of the chiral structure.

The number of layers of the cholesteric liquid crystal material may be one or two or more. It is preferable that the number of layers is two or more because the wavelength band of infrared rays that can be reflected can be expanded.

When two or more cholesteric liquid crystal materials are used, it is preferable to combine cholesteric liquid crystal layers having different molecular axis twist directions in order to more efficiently reflect the central wavelength region to be reflected. That is, both right circularly polarized light and left circularly polarized light can be reflected, and an effective reflectance can be realized. In addition, when two or more cholesteric liquid crystal materials are used, it is preferable to combine cholesteric liquid crystal layers having different pitch lengths when combining a wide range of reflected wavelengths. A wider range of near-infrared wavelength regions can be reflected with high efficiency. As the combination of the number of layers, the right circularly polarized light, the left circularly polarized cholesteric liquid crystal layer, and the like, an appropriate combination can be used in view of manufacturing cost, visible light transmittance, and the like.

As the cholesteric liquid crystal material, a curable liquid crystal composition is preferably used. An example of the liquid crystal composition contains at least a rod-like liquid crystal compound, an optically active compound (chiral compound), and a polymerization initiator. Two or more of each component may be included. For example, a polymerizable liquid crystal compound and a non-polymerizable liquid crystal compound can be used in combination. Also, a combination of a low-molecular liquid crystal compound and a high-molecular liquid crystal compound is possible. Furthermore, in order to improve the uniformity of alignment, applicability, and film strength, it contains at least one selected from various additives such as horizontal alignment, unevenness inhibitor, repellency inhibitor, and polymerizable monomer. Also good. Further, in the liquid crystal composition, a polymerization inhibitor, an antioxidant, an ultraviolet absorber, a light stabilizer, a colorant, metal oxide fine particles, and the like are further added as necessary so as not to deteriorate the optical performance. can do.

(1) Rod-like liquid crystal compound The rod-like liquid crystal compound is a rod-like nematic liquid crystal compound. Examples of the rod-like nematic liquid crystal compound include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, phenyldioxane. Low molecular liquid crystal compounds and high molecular liquid crystal compounds such as alkenyl, tolanes and alkenylcyclohexylbenzonitriles are preferably used.

The rod-like liquid crystal compound used in the present invention may be polymerizable or non-polymerizable. The rod-like liquid crystal compound having no polymerizable group is described in various documents (for example, Y. Goto et.al., Mol. Cryst. Liq. Cryst. 1995, Vol. 260, pp. 23-28). .
The polymerizable rod-like liquid crystal compound can be obtained by introducing a polymerizable group into the rod-like liquid crystal compound. Examples of the polymerizable group include an unsaturated polymerizable group, an epoxy group, and an aziridinyl group, preferably an unsaturated polymerizable group, and particularly preferably an ethylenically unsaturated polymerizable group. The polymerizable group can be introduced into the molecule of the rod-like liquid crystal compound by various methods. The number of polymerizable groups possessed by the polymerizable rod-like liquid crystal compound is preferably 1 to 6, and more preferably 1 to 3. Examples of the polymerizable rod-like liquid crystal compound are described in Makromol. Chem. 190, 2255 (1989), Advanced Materials 5, 107 (1993), US Pat. Nos. 4,683,327, 5,622,648, and 5,770,107, International Publication WO95 / 22586. No. 95/24455, No. 97/00600, No. 98/23580, No. 98/52905, JP-A-1-272551, No. 6-16616, and No. 7-110469. 11-80081 and JP-A 2001-328773, and the like. Two or more kinds of polymerizable rod-like liquid crystal compounds may be used in combination. When two or more kinds of polymerizable rod-like liquid crystal compounds are used in combination, the alignment temperature can be lowered.

(2) Optically active compound (chiral agent)
The liquid crystal composition exhibits a cholesteric liquid crystal phase, and for that purpose, it preferably contains an optically active compound. However, when the rod-like liquid crystal compound is a molecule having an asymmetric carbon atom, the cholesteric liquid crystal layer may be formed stably without adding an optically active compound. The optically active compound is known in various known chiral agents (for example, liquid crystal device handbook, Chapter 3-4-3, TN, chiral agent for STN, 199 pages, edited by Japan Society for the Promotion of Science, 142nd Committee, 1989). ) Can be selected. The optically active compound generally contains an asymmetric carbon atom, but an axially asymmetric compound or a planar asymmetric compound that does not contain an asymmetric carbon atom can also be used as a chiral agent. Examples of the axial asymmetric compound or the planar asymmetric compound include binaphthyl, helicene, paracyclophane, and derivatives thereof. The optically active compound (chiral agent) may have a polymerizable group. When the optically active compound has a polymerizable group and the rod-shaped liquid crystal compound used in combination also has a polymerizable group, the repetition is derived from the rod-shaped liquid crystal compound by a polymerization reaction between the polymerizable optically active compound and the polymerizable rod-shaped liquid crystal compound. Polymers having units and repeating units derived from optically active compounds can be formed. In this embodiment, the polymerizable group possessed by the polymerizable optically active compound is preferably the same group as the polymerizable group possessed by the polymerizable rod-like liquid crystal compound. Therefore, the polymerizable group of the optically active compound is also preferably an unsaturated polymerizable group, an epoxy group or an aziridinyl group, more preferably an unsaturated polymerizable group, and an ethylenically unsaturated polymerizable group. Is particularly preferred. The optically active compound may be a liquid crystal compound.

The optically active compound in the liquid crystal composition is preferably 0.1 mol% to 30 mol% with respect to the liquid crystal compound used in combination. A smaller amount of the optically active compound is preferred because it often does not affect the liquid crystallinity. Therefore, the optically active compound used as the chiral agent is preferably a compound having a strong twisting power so that a twisted orientation with a desired helical pitch can be achieved even with a small amount. As such a chiral agent exhibiting a strong twisting force, for example, a chiral agent described in JP-A No. 2003-287623 can be mentioned and can be preferably used in the present invention.

(3) Polymerization initiator The liquid crystal composition used for forming the light reflecting layer is preferably a polymerizable liquid crystal composition, and for that purpose, it preferably contains a polymerization initiator. In the present invention, since the curing reaction is advanced by irradiation with ultraviolet rays, the polymerization initiator to be used is preferably a photopolymerization initiator capable of starting the polymerization reaction by irradiation with ultraviolet rays. The photopolymerization initiator is not particularly limited. For example, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (“Irgacure 907” manufactured by Ciba Specialty Chemicals), 1-hydroxycyclohexyl phenyl ketone ("Irgacure 184" manufactured by Ciba Specialty Chemicals), 4- (2-hydroxyethoxy) -phenyl (2-hydroxy-2-propyl) ketone ("Irgacure" manufactured by Ciba Specialty Chemicals) 2959 "), 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one (" Darocur 953 "manufactured by Merck & Co.), 1- (4-isopropylphenyl) -2-hydroxy-2- Methylpropan-1-one (Merck "Darocur 1116"), -Hydroxy-2-methyl-1-phenylpropan-1-one ("Irgacure 1173" manufactured by Ciba Specialty Chemicals), acetophenone compounds such as diethoxyacetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether Benzoin compounds such as benzoin isobutyl ether, 2,2-dimethoxy-2-phenylacetophenone (“Irgacure 651” manufactured by Ciba Specialty Chemicals), benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, 3,3′-dimethyl-4-methoxybenzophenone (“Kayacure MBP” manufactured by Nippon Kayaku Co., Ltd.), etc. Benzophenone compound, thioxanthone, 2-chlorothioxanthone (“Kayacure CTX” manufactured by Nippon Kayaku Co., Ltd.), 2-methylthioxanthone, 2,4-dimethylthioxanthone (“Kayacure RTX” manufactured by Nippon Kayaku Co., Ltd.), isopropylthioxanthone, 2, 4 -Diclothiothioxanthone (“Kayacure CTX” manufactured by Nippon Kayaku Co., Ltd.), 2,4-diethylthioxanthone (“Kayacure DETX” manufactured by Nippon Kayaku Co., Ltd.), 2,4-Diisopropylthioxanthone (“Kayacure DITX” manufactured by Nippon Kayaku Co., Ltd.) ) And the like. These photoinitiators may be used independently and 2 or more types may be used together.

The content of the photopolymerization initiator in the composition is not particularly limited, but the preferred lower limit is preferably 0.5 parts by weight, preferably 100 parts by weight of the polymerizable liquid crystal compound or the (meth) acrylate monomer composition. The upper limit is 10 parts by weight or less, the more preferable lower limit is 2 parts by weight, and the more preferable upper limit is 8 parts by weight.

When the benzophenone compound or the thioxanthone compound is used as the photopolymerization initiator, it is preferable to use a reaction aid together in order to promote the photopolymerization reaction. The reaction aid is not particularly limited, and examples thereof include triethanolamine, methyldiethanolamine, triisopropanolamine, n-butylamine, N-methyldiethanolamine, diethylaminoethyl methacrylate, Michler's ketone, 4,4′-diethylaminophenone, 4- Examples include amine compounds such as ethyl dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate (n-butoxy), and isoamyl 4-dimethylaminobenzoate.

The content of the reaction aid in the polymerizable liquid crystal composition is not particularly limited, but is preferably used in a range that does not affect the liquid crystal properties of the polymerizable liquid crystal composition. A preferred lower limit is 0.5 parts by weight, a preferred upper limit is 10 parts by weight or less, a more preferred lower limit is 2 parts by weight, and a more preferred upper limit is 8 parts by weight with respect to a total of 100 parts by weight of the curable polymerizable compound. is there. Moreover, it is preferable that content of the said reaction adjuvant is 0.5 to 2 times amount with respect to content of the said photoinitiator.

Furthermore, a leveling agent, an antifoaming agent, an ultraviolet absorber, a light stabilizer, an antioxidant, a polymerization inhibitor, a crosslinking agent, a plasticizer, inorganic fine particles, a filler, and the like are added to the above composition as necessary. It is also possible to impart the desired functionality. Examples of the leveling agent include fluorine compounds, silicone compounds, acrylic compounds, and the like. Examples of ultraviolet absorbers include benzotriazole compounds, benzophenone compounds, and triazine compounds. Examples of light stabilizers include hindered amine compounds and benzoate compounds. Examples of antioxidants include phenol compounds. Is mentioned.
Examples of the polymerization inhibitor include methoquinone, methylhydroquinone, hydroquinone and the like, and examples of the crosslinking agent include the polyisocyanates and melamine compounds.
Plasticizers include phthalates such as dimethyl phthalate and diethyl phthalate, trimellitic esters such as tris (2-ethylhexyl) trimellitate, aliphatic dibasic esters such as dimethyl adipate and dibutyl adipate, tributyl phosphate and triphenyl. Examples thereof include orthophosphate esters such as phosphate and acetate esters such as glyceryl triacetate and 2-ethylhexyl acetate.

The method for applying the cholesteric liquid crystal layer is not particularly limited, and examples thereof include a comma coater, a spray coater, a roll coater, a knife coater, and the like, but preferably a bar coater, a spin coater, It is preferable to use a coating apparatus suitable for thin film production such as a die coater or a micro gravure coater. Further, in order to more precisely define the alignment direction of the liquid crystal compound in the cholesteric liquid crystal layer, the surface of the layer (fine particle layer, substrate, etc.) to which the cholesteric liquid crystal layer is applied may be aligned. In order to align, it is preferable to form an alignment surface by rubbing the surface of the substrate.

The birefringent multilayer film combined with the infrared shielding sheet of the present invention includes a layer having birefringence (preferably positive birefringence) (hereinafter, birefringent layer) and a layer having isotropic refraction or negative birefringence (hereinafter, etc.). Birefringent layers), and is based on the coherent interference caused by the refractive index difference between the birefringent layer and the isotropic refractive layer and the respective geometric film thicknesses. When the in-plane refractive index is different between the birefringent layer and the isotropic refractive layer, the interface between the two layers forms a reflective surface.

Birefringence means that the refractive indices in the orthogonal x, y and z directions are not all the same. In the case of an oriented polymer, the x-axis and y-axis are in the plane of the layer, the z-axis is perpendicular to the plane of the layer, and for oriented polymers, the x-axis is chosen to be the in-plane direction with the highest refractive index, The direction corresponds to one of the directions in which the optical body is oriented (eg, stretched).

The in-plane refractive indexes of both the birefringent layer and the isotropic refractive layer are different between the layers (ie, n _1x ≠ n _2x , n _1y ≠ n _2y , where n _1x and n _1y are the in-plane refractive indices of the birefringent layer And n _2x and n _2y are the in-plane refractive indices of the isotropic refractive layer). Further, it is preferable that the z-axis refractive indexes of the birefringent layer and the isotropic refractive layer are equal, since the reflection of p-polarized light does not depend on the incident angle of light, and the reflectance becomes uniform over the range of viewing angles.

In order to increase the in-plane refractive index of the birefringent layer, a birefringent polymer (preferably a polymer having positive birefringence) that is uniaxially or preferably biaxially oriented is used, and isotropically refracted with the birefringent layer. Increase the refractive index difference of the layer.

The optical film thickness of each layer is controlled to be λ _c / 4 where λ _c is the center wavelength of the wavelength region to be reflected. As the birefringent layer material, a material that is oriented by stretching (positive birefringence) is used. For example, PEN (polyethylene naphthalate), PET, or the like is used. As the isotropic refractive material, a material that is not oriented by stretching (or a material that is negatively birefringent by stretching) is used. For example, PMMA (polymethyl methacrylate) or the like is used. In addition, the birefringent multilayer structure material can be produced by forming a multilayer film and stretching it by, for example, a co-extrusion method described in JP-T-2008-528313. Since the refractive index difference between the birefringent layer and the isotropic refractive layer is small, a large number of layers must be laminated. The number of stacked layers is preferably 3 or more and 1000 or less in view of the reflection region to be reflected, the manufacturing cost, and the like.

"Interlayer film for laminated glass"
The interlayer film for laminated glass of the present invention is formed using the infrared shielding sheet of the present invention, and has an interlayer film on one outermost layer of the infrared shielding sheet. The intermediate film for laminated glass of the present invention preferably includes an intermediate film on both outermost layers of the infrared shielding sheet of the present invention, from the viewpoint of facilitating laminated glass formation.

It is preferable that the interlayer film for laminated glass of the present invention further includes a second interlayer film. In ordinary laminated glass, the film thicknesses of the first and second intermediate films on both sides of the infrared shielding sheet are the same, but the present invention is not limited to the method for producing an interlayer film for laminated glass in such an aspect. The laminate can also be manufactured so that the first and second intermediate films have different thicknesses. Further, the compositions of the first and second intermediate films may be the same or different.

The heat shrinkage rate before and after the step of pressure bonding the intermediate film for laminated glass of the first and second intermediate films while heating is preferably 1 to 20% in the range of the heating temperature at that time, and 2 to 15 % Is more preferable, and 2 to 10% is particularly preferable. The thickness of the first and second interlayer films is preferably 100 to 1000 μm, more preferably 200 to 800 μm, and particularly preferably 300 to 500 μm. The first and second intermediate films may be thickened by overlapping a plurality of sheets.

Further, as a criterion for brittleness of the first and second interlayer films, the elongation at break by a tensile test is preferably 100 to 800%, more preferably 100 to 600%, and more preferably 200 to 500%. It is particularly preferred.

The first and second intermediate films are preferably resin intermediate films. The resin interlayer is preferably a polyvinyl acetal-based resin film as a main component. There is no restriction | limiting in particular as said polyvinyl acetal type-resin film, For example, what is described in Unexamined-Japanese-Patent No. 6-000926, Unexamined-Japanese-Patent No. 2007-008797 etc. can be used preferably. Among the polyvinyl acetal resin films, a polyvinyl butyral resin film is preferably used in the present invention. The polyvinyl butyral resin film is not particularly defined as long as it is a resin film mainly composed of polyvinyl butyral, and a widely known polyvinyl butyral resin film as an interlayer film for laminated glass can be employed. Among them, in the present invention, the intermediate film is preferably a resin intermediate film mainly composed of polyvinyl butyral or a resin intermediate film mainly composed of ethylene vinyl acetate, and a resin intermediate film mainly composed of polyvinyl butyral. It is particularly preferred that In addition, resin which is a main component means resin which occupies the ratio of 50 mass% or more of the said resin intermediate film.

The first and second interlayer films may contain an additive within a range not departing from the gist of the present invention. Examples of the additive include fine particles for heat ray shielding, fine particles for sound insulation, and a plasticizer. Examples of the heat ray shielding fine particles and the sound insulation fine particles include inorganic fine particles and metal fine particles. By dispersing and mixing such fine particles in an elastic body such as the first or second intermediate film, a heat shielding effect can be obtained. At the same time, with such a configuration, it is preferable to inhibit the propagation of sound waves and obtain a vibration damping effect. The structure of the fine particles is preferably spherical, but may not be true. The shape may be changed. The fine particles are desirably dispersed in an intermediate film (preferably polyvinyl butyral “hereinafter PVB”), and may be added in an appropriate capsule or added together with a dispersant. The addition amount in this case is not particularly limited, but is preferably 0.1 to 10% by mass of the resin component.

Inorganic fine particles include calcium carbonate, alumina, kaolin clay, calcium silicate, magnesium oxide, magnesium hydroxide, aluminum hydroxide, magnesium carbonate, talc, feldspar powder, mica, barite, barium carbonate, titanium oxide, silica, glass beads. Etc. These may be used alone or in combination.

Further, as the heat ray shielding fine particles, tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide (AZO), indium-doped zinc oxide (IZO), tin-doped zinc oxide, silicon-doped zinc oxide, Examples thereof include zinc antimonate, lanthanum hexaboride, cerium hexaboride, fine gold powder, fine silver powder, fine platinum powder, fine aluminum powder, iron, nickel, copper, stainless steel, tin, cobalt, and alloy powders containing these. Examples of the light shielding agent include carbon black and red iron oxide. The pigment is a dark reddish-brown mixture formed by mixing four types of pigments: black pigment carbon black, red pigment (CI Pigmentred), blue pigment (CI Pigmentblue), and yellow pigment (CI Pigmentyellow). And pigments.

It does not specifically limit as a plasticizer, The well-known plasticizer generally used as a plasticizer for this kind of intermediate film can be used. For example, triethylene glycol-di-2-ethylbutyrate (3GH), triethylene glycol-di-2-ethylhexanoate (3GO), triethylene glycol-di-n-heptanoate (3G7), tetraethylene glycol- Di-2-ethylhexanoate (4GO), tetraethylene glycol-di-n-heptanoate (4G7), oligoethylene glycol-di-2-ethylhexanoate (NGO) and the like are preferably used. These plasticizers are generally used in a range of 25 to 70 parts by mass with respect to 100 parts by mass of a resin (preferably polyvinyl acetal resin) that is a main component of the resin interlayer.

It is preferable that the manufacturing method of the intermediate film for laminated glasses of this invention includes the process of heat-bonding the said intermediate film and the said infrared shielding sheet after laminating | stacking in order of the infrared shielding sheet / intermediate film of this invention. There is no restriction | limiting in particular as the method of thermal bonding, The thermocompression bonding which presses a heating body, the heat sealing | fusion by the heating by laser irradiation, etc. are employable. Among them, in the method for producing a laminate of the present invention, it is preferable that the step of thermally bonding the infrared shielding sheet to the intermediate film is thermocompression bonding.
Although there is no restriction | limiting in particular as the method of thermocompression bonding, For example, the method of pressing a 80-140 degreeC heating body is preferable. The heating body may be a flat surface, a curved surface, or a roller. For thermocompression bonding, a plurality of heating rollers, a heatable flat pressing surface, or the like can be used, and these may be used in combination. Further, the thermocompression bonding may be performed on both surfaces of the infrared shielding sheet / interlayer laminate, or only on one surface. In that case, one of the rollers used for thermocompression bonding is not heated. It may be a roller or a pressing surface. Among these, the method for producing a laminate of the present invention preferably uses a heating roller in the thermocompression bonding step, and more preferably uses a combination of a heating roller and a non-heating roller.

Usually, the surface of the intermediate film is roughened by embossing or the like so that air can easily escape during sticking. The bonded surface becomes smooth following the adherend surface, and the optical performance is improved. However, the other surface needs to be maintained in a rough state in order to be bonded to a glass plate or the like. Therefore, it is preferable that the surface of the roller on the side in contact with the intermediate film in the thermocompression-bonding roller is roughened so as to keep the roughened state of the intermediate film. That is, it is preferable to laminate so that at least one surface of the intermediate film is embossed and the embossed surface is in contact with the sheet of the present invention. Moreover, you may actively emboss the surface which is not in contact with the infrared shielding sheet of an intermediate film after thermocompression bonding.

In addition, the transparent support body used at the time of infrared shielding sheet preparation may peel before and after the said heat bonding process, and is good also as a part of intermediate film for laminated glasses, without peeling.

It is preferable that the manufacturing method of the intermediate film for laminated glasses of this invention includes the process of laminating | stacking a 2nd intermediate film on the opposite surface of the infrared shielding sheet with which the 1st intermediate film was laminated | stacked. That is, the interlayer film for laminated glass of the present invention preferably has a second interlayer film. The infrared shielding sheet 2 and the second intermediate film 3 ′ may be adjacent to each other and may include other constituent layers therebetween, but the infrared shielding sheet 2 and the second intermediate film 3 ′ are It is preferable that it adjoins.
These laminates are preferably thermocompression bonded by the same method as in the thermocompression bonding process of the first intermediate film and the infrared shielding sheet.

The interlayer film for laminated glass including the infrared shielding sheet and the interlayer film may be cut with a blade during processing, or may be cut with a laser, a water jet or heat.

Although the use of the laminated glass of this invention does not have a restriction | limiting in particular, It is preferable for window glass, such as a house and a motor vehicle. The laminated glass of the present invention has the interlayer film for laminated glass of the present invention obtained as described above and at least two glass plates, and the interlayer film for laminated glass is inserted into the two glasses. It is characterized by. Moreover, the laminated glass of this invention can be preferably cut | judged to arbitrary sizes.

There is no restriction | limiting in particular in the method of laminating | stacking the intermediate film for laminated glasses with 1st glass or 2nd glass, It can insert and laminate | stack between two glass plates by a well-known method.

The laminate sandwiched between the glass plates has a configuration in which the glass plate / intermediate film / infrared shielding sheet / intermediate film / glass plate are laminated in this order.

FIG. 4 is a schematic view showing an example of the structure of a laminated glass including an interlayer film for laminated glass sandwiched between glass plates, which is obtained by the production method of the present invention. The edge part of the infrared shielding sheet 2 may exist inside the glass plate 5 and 5 'edge part and the edge part of 1st intermediate film 3 and 2nd intermediate film 3'. Moreover, even if the edge part of glass plate 5 and 5 'and the 1st intermediate film 3 and 2nd intermediate film 3' end are the same positions, either may protrude.
Moreover, as shown in FIG. 4, as for the laminated body pinched | interposed into the glass plate, the edge part of the infrared shielding sheet 2 may exist in the same position as the edge part of a glass plate, and the edge part of an intermediate film. On the other hand, the edge part of the infrared shielding sheet 2 may be configured to protrude beyond the end parts of the glass plates 5 and 5 ′ and the end parts of the first intermediate film 3 and the second intermediate film 3 ′.

In the laminate sandwiched between the glass plates, the infrared shielding sheet 2 and the first intermediate film 3, and the infrared shielding sheet 2 and the second intermediate film 3 ′ may be adjacent to each other, or other constituent layers. You may have.

In the method for producing a laminated glass of the present invention, it is preferable that the glass plate is a curved glass even if the glass plate has no curvature. The two glass plates sandwiching the interlayer film for laminated glass may have different thicknesses or may be colored. In particular, when used for a windshield of an automobile for the purpose of heat insulation, a coloring component such as a metal is added to the glass so that the visible light transmittance in a laminated glass state does not fall below 70% defined in JIS-R3211. The heat shielding property can be effectively improved by using green glass in general. About the color density of green glass, it is preferable to adjust to the density | concentration suitable for the objective by adjusting the quantity of the metal component to add or adjusting thickness.

It is preferable that the manufacturing method of the laminated glass of this invention includes the process of crimping | bonding, heating the intermediate film for laminated glasses of this invention pinched | interposed into the glass plate.
The lamination of the laminate of the present invention sandwiched between glass plates and the glass plate is, for example, pre-pressed at a temperature of 80 to 120 ° C. for 30 to 60 minutes under reduced pressure with a vacuum bag or the like, and then in an autoclave. Lamination can be performed at a temperature of 120 to 150 ° C. under a pressure of 1.0 to 1.5 MPa, and a laminated glass in which a laminate is sandwiched between two glasses can be obtained.
After the thermocompression bonding, there is no particular limitation on the method of cooling, and the laminated glass body may be obtained by cooling while releasing the pressure as appropriate. In the present invention, it is preferable to lower the temperature while maintaining the pressure after completion of the thermocompression bonding from the viewpoint of further improving the wrinkles and cracks of the obtained laminated glass body.
In the present invention, it is preferable to include a step of releasing the pressure after the temperature is lowered while the pressure is maintained. Specifically, it is preferable to lower the temperature by releasing the pressure after the temperature in the autoclave becomes 40 ° C. or lower after the temperature is lowered while the pressure is maintained.

  Hereinafter, the present invention will be described in more detail with reference to examples. In Examples, “part” means “part by weight” and “%” means “% by weight”.

(Measurement of surface resistance)
The surface resistance was measured using a surface resistance meter (High Lester UP, Lorestar GP, manufactured by Mitsubishi Chemical Analytech Co., Ltd.).
(Measurement of refractive index and extinction coefficient)
The refractive index and the extinction coefficient with respect to the wavelength of each layer were prepared on a PET substrate and measured with a spectroscopic ellipsometer (M-2000, manufactured by JA Woollam).

Example 1
(Preparation of high refractive index resin coating solution 1)
1.4 parts of titanium oxide (TTO-51A, manufactured by Ishihara Sangyo) having an average particle diameter of 35 nm, 0.4 parts of KAYARAD DPHA, 0.05 parts of Irgacure 907, 0.3 parts of aminoalkyl methacrylate copolymer dispersant are added to toluene. In addition to 7 parts, it was dispersed at a peripheral speed of 10 m / s using a bead mill to prepare a high refractive index resin layer coating solution (high flexure solution 1).

(Preparation of low refractive index resin coating solution 1)
1.4 parts of tin-doped indium oxide (hereinafter referred to as ITO) having an average particle diameter of 25.6 nm and a powder resistance of 0.8 Ω · cm, 0.4 parts of KAYARAD DPHA, 0.05 parts of Irgacure 184, aminoalkyl methacrylate 0.3 part of the coalesced dispersant was added to 7 parts of toluene and dispersed at a peripheral speed of 10 m / s using a bead mill to prepare a low refractive index resin layer coating liquid (low bending liquid 1).

(Preparation of low refractive index resin coating solution 2)
KAYARAD DPHA (trade name, dipentaerythritol hexaacrylate, Nippon Kayaku) 0.4 parts, Irgacure 184 (photopolymerization initiator, BASF Japan) 0.05 parts dissolved in methyl ethyl ketone (hereinafter MEK) 4 parts In this process, 3 parts of hollow silica (V8216, average particle size 50 nm, solid content concentration 20% by weight, manufactured by JGC Catalysts & Chemicals) was dispersed to prepare a low refractive index resin layer coating solution (low bending solution 2).

(Production of laminated film)
The reflection wavelength was set to 1000 nm, and the coating liquid was appropriately diluted on the PET substrate so that the QWOT coefficient was the value shown in Table 1, and each layer was laminated to produce an infrared shielding sheet of the present invention having 8 layers. . Each layer was applied by a wire bar, dried at 100 ° C. for 2 minutes to evaporate the solvent, and then produced by UV irradiation.

Example 2
An infrared shielding sheet of the present invention having 8 layers was produced in the same manner as in Example 1 except that the wavelength to be reflected was set to 1000 nm and the QWOT coefficient was laminated so as to have the value shown in Table 2.

Example 3
The infrared shielding sheet of the present invention having 12 layers was prepared in the same manner as in Example 1 except that the wavelength to be reflected was set to 1000 nm and the QWOT coefficient was laminated so as to have the values shown in Table 3.

Example 4
(Preparation of low refractive index resin coating solution 3)
1.1 parts of tin-doped indium oxide (hereinafter referred to as ITO) having an average particle diameter of 25.6 nm and a powder resistance of 0.8 Ω · cm, 0.4 parts of KAYARAD DPHA, 0.05 parts of Irgacure 184, co-polymerized with aminoalkyl methacrylate 0.3 part of the coalesced dispersant was added to 7 parts of toluene and dispersed at a peripheral speed of 10 m / s using a bead mill. 1.5 parts of hollow silica (V8216, average particle size 50 nm, solid content concentration 20% by weight, manufactured by JGC Catalysts & Chemicals) is dispersed in the prepared ITO dispersion liquid, and a low refractive index resin layer coating liquid (low bending liquid 3). Was prepared.

(Production of laminated film)
An infrared shielding sheet of the present invention having 6 layers was produced in the same manner as in Example 1 except that the wavelength to be reflected was set to 1000 nm and the QWOT coefficient was laminated so as to be the value shown in Table 4.

Example 5
(Infrared absorbing dye synthesis example)
To 120 parts of sulfolane, 15.9 parts of naphthalic anhydride, 29 parts of urea, 0.40 part of ammonium molybdate and 3.5 parts of vanadyl chloride (V) were added, and the temperature was raised to 200 ° C. and reacted at the same temperature for 11 hours. It was. After completion of the reaction, the reaction mixture was cooled to 65 ° C., 100 parts of N, N-dimethylformamide (DMF) was added, and the precipitated solid was separated by filtration. The obtained solid was washed with 50 parts of DMF to obtain 20.3 parts of a wet cake. The obtained wet cake was added to 100 parts of DMF, heated to 80 ° C., and stirred at the same temperature for 2 hours. The precipitated solid was separated by filtration and washed with 200 parts of water to obtain 18.9 parts of a wet cake. The obtained wet cake was added to 150 parts of water, heated to 90, and stirred at the same temperature for 2 hours. The precipitated solid was separated by filtration and washed with 200 parts of water to obtain 16.1 parts of a wet cake. The obtained wet cake was dried at 80 ° C. to obtain 12.3 parts of an infrared absorbing dye.

(Preparation of infrared absorbing dye layer)
0.02 part of the synthesized infrared absorbing dye, 1 part of KAYARAD DPHA, 0.05 part of Irgacure 184 and 0.01 part of an aminoalkyl methacrylate copolymer dispersant are added to 7 parts of toluene, and the peripheral speed is measured using a bead mill. An infrared absorbing dye layer coating solution was prepared by dispersing at 10 m / s.

The infrared absorbing dye coating solution is applied to a PET substrate with a wire bar so that the geometric film thickness is 4 μm, dried at 100 ° C. for 2 minutes to evaporate the solvent, and then the infrared absorbing dye layer is formed by UV irradiation. Produced.

(Production of laminated film)
It laminated | stacked on the produced infrared absorption pigment | dye layer like Example 1, and the infrared shielding sheet of this invention was produced.

Example 6
(Cholesteric liquid crystal film production)
10 parts of LC-242 (rod-like liquid crystal compound, manufactured by BASF), 0.25 part of LC-756 (manufactured by BASF), 0.5 part of lucillin TPO (polymerization initiator, BASF) in 26 parts of cyclopentanone In addition, a liquid crystal film coating solution 1 was prepared.
Moreover, LC-756 in the liquid crystal film coating solution 1 was changed to 0.3 part to prepare a liquid crystal coating solution 2.

The liquid crystal film coating solutions 1 and 2 are applied to a PET substrate with a wire bar so that the geometric film thickness is 4 μm respectively, dried at 130 ° C. for 2 minutes to evaporate the solvent, and then UV-irradiated to form a cholesteric liquid crystal layer. Produced.

(Production of laminated film)
The number of layers is 6 as in Example 1 except that the wavelength reflected on the PET substrate surface opposite to the prepared cholesteric liquid crystal layer is set to 1000 nm and laminated so that the QWOT coefficient becomes the value shown in Table 5. An infrared shielding sheet of the invention was produced.

Comparative Example 1
(Preparation of low refractive index layer)
While dissolving 1 part of KAYARAD DPHA (trade name, dipentaerythritol hexaacrylate, Nippon Kayaku) and 0.01 part of Irgacure 184 (photopolymerization initiator, manufactured by BASF Japan) in 10 parts of methyl ethyl ketone (hereinafter MEK) Then, 3.8 parts of silicon oxide (MEK-ST, average particle size 15 nm, manufactured by Nissan Chemical Industries, Ltd.) was dispersed to prepare a low refractive index layer coating solution (low flexion solution 4).

(Production of laminated film)
A comparative infrared shielding sheet having 8 layers was prepared in the same manner as in Example 1 except that the wavelength to be reflected was set to 1000 nm and the QWOT coefficient was laminated so as to have the values shown in Table 6.

Table 7 shows the results of measuring the visible light transmittance, haze, and total solar radiation energy of the infrared shielding sheets of Examples 1 to 6 and Comparative Example 1.
(Measurement of visible light transmittance)
The visible light transmittance at a wavelength of 380 nm to 780 nm of the obtained infrared shielding sheet was measured using a spectrophotometer (UV-3100 manufactured by Shimadzu Corporation) in accordance with JIS R3106.
(Measurement of total solar energy (Tts))
Total solar energy (Tts) is a measure of how much of the thermal energy from the sun is transmitted through the target material, and was calculated using a formula defined in ISO13837. The smaller the calculated numerical value, the smaller the total solar radiation energy, and the higher the heat ray shielding property.
(Measurement of haze value)
Using a haze meter (TC-HIIIDPK manufactured by Tokyo Denshoku Co., Ltd.), the haze value of the obtained infrared shielding sheet was measured according to JIS K6714.

1, FIG. 2 and Table 7 show that the infrared shielding sheet of the present invention absorbs the wavelength of 1500 nm to 2500 nm in addition to efficiently reflecting the wavelength of 780 nm to 1500 nm compared to the comparative example. Thus, Tts was greatly improved.

In Examples 5 and 6, when combined with the infrared shielding sheet of the present invention, infrared rays could be shielded more effectively while maintaining the transmittance.

Since Comparative Example 1 has no near-infrared absorption by fine particles, Tts is insufficient, and heat rays after 1500 nm at which a person feels irritating is not shielded, so that it may feel uncomfortable. Concerned.

Example 7
"Preparation of interlayer film for laminated glass"
A laminate was obtained by overlaying PVB, which is an intermediate film, on the infrared shielding sheet of each example produced. A position of 1 mm or less from the end of the infrared shielding sheet on the entire circumference (4 sides) is sandwiched between two laminating heating rollers arranged on the front side and the back side of the obtained laminate, and the infrared shielding sheet and the intermediate film Were bonded by thermocompression bonding. At this time, the laminating heating roller is set to 25 ° C. so that the embossing on the back surface of the intermediate film is not crushed, and conversely, the embossing on the infrared shielding sheet side surface of the intermediate film is sufficiently crushed. The heating roller for laminating on the transparent support (PET) side was set to 120 ° C. so as to enhance the adhesion between the infrared shielding sheet 2 and the infrared shielding sheet 2. Then, PVB which is a 2nd intermediate film was laminated | stacked, and the intermediate film for laminated glasses of each Example was produced.

“Laminated glass”
The produced laminated film was laminated and sandwiched between glass plates so that the intermediate film for laminated glass was glass / intermediate film / infrared shielding sheet / second intermediate film / glass. Here, the edge part of the glass plate and the edge part of the intermediate film were the same positions. The glass plate having a thickness of 2 mm was used. The laminate sandwiched between the obtained glass plates was pre-pressed under vacuum at 95 ° C. for 30 minutes. After preliminary pressure bonding, the laminate sandwiched between the glass plates was pressure-bonded while being heated in an autoclave at 1.3 MPa and 120 ° C. to produce a laminated glass.

When the performance of the laminated glass including the infrared shielding sheet of each example, which was prepared in Example 7, was evaluated, it works as a transparent heat-shielding glass that is free from significant defects and streaks and has a haze of 0.5 or less. It was confirmed

According to the present invention, it has been found that, by providing infrared reflectivity utilizing a difference in refractive index in addition to the infrared absorption capability of fine particles, temperature increase due to infrared rays is suppressed as compared with conventional infrared shielding sheets. As a result, the temperature rise in the space of houses and cars can be suppressed, the load on the air conditioning equipment can be reduced, and energy saving and global environmental problems can be contributed. Furthermore, since the infrared region can be selectively shielded, it can be used for building window members, vehicle window members, refrigeration, frozen showcase window glass, IR cut filters, forgery prevention, and the like.

DESCRIPTION OF SYMBOLS 1 ... Intermediate film for laminated glass 2 ... Infrared shielding sheet (a transparent support may be included)
3, 3 '... intermediate film 4 ... laminated glass 5, 5' ... glass plate

Claims (13)

A high refractive index resin layer (A) containing fine particles on a transparent support and a low refractive index resin layer (B) containing fine particles and exhibiting a lower refractive index than the layer (A) in the infrared region of 780 nm to 2500 nm. In the laminated film alternately laminated, at least one layer of the low refractive index resin layer (B) has a value obtained by subtracting the refractive index at an arbitrary wavelength at 780 nm or more from the refractive index at 550 nm, and An infrared shielding sheet, wherein the QWOT coefficient of the optical film thickness of at least one layer of the high refractive index resin layer (A) and / or at least one layer of the low refractive index resin layer is 1.5 or more. 2. The infrared shielding sheet according to claim 1, wherein (A) and (B) each layer has a surface resistance of 1 kΩ / □ or more, and the total number of layers of (A) and (B) is 4 or more. The infrared shielding sheet according to claim 1 or 2, wherein the visible light transmittance is 50% or more and the haze is 8% or less. Fine particles contained in the high refractive index resin layer (A) are titanium oxide, zirconium oxide, hafnium oxide, tantalum oxide, tungsten oxide, niobium oxide, cerium oxide, lead oxide, diamond, zinc oxide, boride and nitride. The infrared shielding sheet according to any one of claims 1 to 3, wherein the infrared shielding sheet is at least one kind of fine particles selected from the group consisting of: The fine particles contained in the low refractive index resin layer (B) are at least one kind of fine particles selected from the group consisting of tin oxide, indium oxide, zinc oxide, tungsten oxide, and silica. The infrared shielding sheet according to 1. Fine particles contained in the low refractive index resin layer (B) are Sb-doped tin oxide (ATO), Sn-doped indium oxide (ITO), Ga-doped zinc oxide (GZO), oxygen-deficient tungsten oxide, Cs-doped tungsten oxide, hollow The infrared shielding sheet according to claim 1, which is at least one selected from the group of silica. The infrared shielding sheet according to any one of claims 1 to 6, wherein the content of fine particles contained in the high refractive index resin layer (A) or the low refractive index resin layer (B) is 90% by weight or less. The infrared shielding sheet according to any one of claims 1 to 7, wherein the high refractive index resin layer and the low refractive index resin layer are formed by coating . An infrared shielding sheet according to any one of claims 1 to 8, a cholesteric liquid crystal film that selectively reflects 780 nm to 2000 nm, a birefringent multilayer film, or an infrared absorbing dye that selectively absorbs 780 nm to 2500 nm. An infrared shielding sheet formed by combining at least one kind. The intermediate film for laminated glasses which has an intermediate film on the outermost layer of any one of the infrared shielding sheets as described in any one of Claims 1 thru | or 9. The interlayer film for laminated glass according to claim 10 , comprising polyvinyl butyral in the interlayer film. Laminated glass obtained by inserting the interlayer film for laminated glass according to claim 10 or 11 between a plurality of glass plates. The member for windows obtained by laminating | stacking the infrared shielding sheet as described in any one of Claims 1 thru | or 9, the intermediate film for laminated glasses of Claim 10 or 11, or the laminated glass of Claim 12.