Heat ray shielding film and agricultural greenhouse

Abstract

The heat-ray-shielding film comprises a thermoplastic resin base material A, a heat-ray-shielding layer containing a binder resin and inorganic particles, and a thermoplastic resin base material B in this order.

Description

Technical Field

[0001] The present invention relates to a heat ray shielding film and an agricultural greenhouse. Background Art

[0002] Conventionally, resin films have been widely used for applications such as building and vehicle window materials and agricultural greenhouses. However, during periods of intense sunlight, such as summer, sunlight penetrates through the resin films and enters indoor spaces, raising indoor temperatures.

[0003] Patent Document 1 discloses a fluororesin film that combines indium tin oxide (ITO) with a specific particle size and a cyan pigment with a specific particle size. The respective contents of ITO and cyan pigment have a specific relationship with film thickness. This fluororesin film controls the transmittance of harmful light without compromising transparency, mechanical properties, weather resistance, and other properties. It also exhibits excellent colorless transparency and heat-shielding properties, without the yellowing associated with the addition of ITO.

[0004] Patent Document 2 also discloses a heat-shielding film comprising a metal-doped indium oxide film of a specific thickness formed on the surface of a transparent substrate. The metal-doped indium oxide film of the specific thickness is formed by sputtering. This heat-shielding film exhibits excellent visible light transmittance and heat ray reflectivity. Prior art literature Patent Literature

[0005] Patent Document 1: International Publication No. 2013 / 125548 Patent Document 2: Japanese Patent Application Laid-Open No. 2008-105297 Summary of the Invention Technical problem to be solved by the invention

[0006] However, considering the current situation of global warming in recent years, people are looking for a better heat shielding effect. In addition, people are seeking a heat ray shielding film with excellent durability. Therefore, the technical problem addressed by the present disclosure is to provide a heat ray shielding film having excellent long-term heat ray shielding properties and an agricultural greenhouse including the heat ray shielding film. Technical solutions used to solve technical problems

[0007] In order to overcome the above technical problems, the following specific measures are adopted. <1> A heat ray shielding film comprising a thermoplastic resin substrate A, a heat ray shielding layer containing a binder resin and inorganic particles, and a thermoplastic resin substrate B in this order. <2> The heat ray shielding film according to <1>, wherein the heat ray shielding layer has an average thickness of 1 μm or less. <3> The heat ray shielding film according to <1> or <2>, wherein the inorganic particles include indium tin oxide. <4> The heat ray shielding film according to any one of <1> to <3>, wherein at least one of the heat ray shielding layer and the thermoplastic resin substrate A and the heat ray shielding layer and the thermoplastic resin substrate B comprises an adhesive layer or a bonding layer. <5> The heat ray shielding film according to <4>, wherein at least one of the cling layer or the adhesive layer contains a UV absorber. <6> The heat ray shielding film according to any one of <1> to <5>, wherein the thermoplastic resin substrate A and the thermoplastic resin substrate B each independently comprise at least one thermoplastic resin selected from polyolefin resins, polyvinyl chloride resins, polyethylene terephthalate resins, and fluororesins. <7> The heat ray shielding film according to any one of <1> to <6>, wherein at least one of the thermoplastic resin substrate A and the thermoplastic resin substrate B contains a fluororesin, and the fluororesin is a thermoplastic resin. <8> The heat ray shielding film according to <1> to <7>, wherein the value of (visible light transmittance - solar light transmittance) / visible light transmittance × 100 is 10% or more, and the ratio of the solar light transmittance after the following exposure treatment to the solar light transmittance before the exposure treatment is 1.05 or less. Exposure treatment: According to JIS K7350-4:2008, exposure was performed under an open carbon arc lamp for 5000 hours. <9> The heat ray shielding film according to any one of <1> to <8>, wherein at least one of the thermoplastic resin substrate A and the thermoplastic resin substrate B has a dripping layer on an outer side surface. <10> The heat ray shielding film according to any one of <1> to <9>, which is for agricultural use. <11> An agricultural greenhouse comprising the heat ray shielding film according to any one of <1> to <10>. Effects of the Invention

[0008] According to the present disclosure, a heat ray shielding film having excellent long-term heat ray shielding properties and an agricultural greenhouse including the heat ray shielding film can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a schematic cross-sectional view illustrating the layer structure of an example of the heat ray shielding film of the present disclosure. DETAILED DESCRIPTION

[0010] The following describes the embodiments of the present disclosure in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps, etc.) are not required unless otherwise specified. The numerical values ​​and their ranges are also not limiting to the present disclosure. In the present disclosure, a numerical range represented by “to” includes the numerical values ​​described before and after “to” as a minimum value and a maximum value, respectively. In the numerical ranges described in this disclosure, the upper limit or lower limit of one numerical range may be replaced by the upper limit or lower limit of another numerical range described in the disclosure. In addition, in the numerical ranges described in this disclosure, the upper limit or lower limit of the numerical range may be replaced by the value shown in the Examples. In the present disclosure, each component may contain multiple corresponding substances. When multiple substances corresponding to each component are present in the composition, the content rate or amount of each component refers to the total content rate or total amount of the multiple substances present in the composition, unless otherwise specified. In the present disclosure, particles corresponding to each component may include multiple types of particles. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component refers to the value of the mixture of the multiple types of particles present in the composition, unless otherwise specified. In the present disclosure, the term "layer" includes not only a case where the layer is formed in the entire region when the region where the layer exists is observed, but also a case where the layer is formed in only a part of the region.

[0011] Heat ray shielding film The heat ray-shielding film of the present disclosure includes a thermoplastic resin substrate A, a heat ray-shielding layer containing a binder resin and inorganic particles, and a thermoplastic resin substrate B in this order. The above-mentioned configuration provides excellent long-term heat ray shielding properties. The reason for this is presumably as follows, but the present invention is not limited to the following presumption.

[0012] In Patent Document 1, a fluororesin film is kneaded with indium tin oxide and a cyan pigment, and particles of indium tin oxide and the cyan pigment are dispersed in the fluororesin. Therefore, the fluororesin is present between these particles, separating them from each other. Sunlight (infrared rays) enter through these separated areas, reducing heat shielding properties. Furthermore, increasing the particle content to minimize the distance between particles can make the fluororesin film brittle, making film formation difficult. The heat-shielding film disclosed herein separates the substrate, which functions as a self-supporting film, from the layer that performs the heat-shielding function into separate layers, resulting in a film with excellent heat-shielding properties. Since the heat-shielding layer is a separate layer, the amount of inorganic particles in the heat-shielding layer and the thickness of the heat-shielding layer can be freely designed, resulting in an increased inorganic particle content per unit area, thereby achieving a film with excellent heat-shielding properties.

[0013] Although the metal-doped indium oxide film in Patent Document 2 is formed as a separate layer from the transparent substrate, it is formed by sputtering, which easily increases manufacturing costs. Furthermore, since the metal-doped indium oxide film in Patent Document 2 is a sputtered film, despite the dense presence of the metal-doped indium oxide and excellent heat-shielding properties, heat-shielding films that can withstand longer-term use are still sought. The term "long-term" in this disclosure refers to approximately 5,000 hours, as described in the accelerated weathering test shown in the Examples.

[0014] The heat-ray shielding film of the present invention is provided with a thermoplastic resin substrate on both sides of the heat-ray shielding layer, so that the falling off, deterioration, damage etc. of the inorganic particles contained in the heat-ray shielding layer are suppressed, and long-term heat-ray shielding is maintained. In addition, it is clear that if a thermoplastic resin substrate is configured on a sputtered film of metal-doped indium oxide, the adhesion at its interface is easy to decrease, and the heat-ray shielding is easy to decrease during long-term use. In the present invention, the heat-ray shielding layer contains an adhesive resin, thereby improving the adhesion of the heat-ray shielding layer and the thermoplastic resin substrate, and becoming a heat-ray shielding film with excellent long-term heat-ray shielding. In addition, since the amount of the adhesive resin in the heat-ray shielding layer can be suitably designed, even if the heat-ray shielding layer contains an adhesive resin, a heat-ray shielding film with excellent heat-ray shielding can be obtained.

[0015] Figure 1 This is a schematic cross-sectional view illustrating the layer structure of an example of the heat ray shielding film of the present disclosure. Figure 1 The heat ray shielding film (10) is provided with a thermoplastic resin substrate A (2), a heat ray shielding layer (4), and a thermoplastic resin substrate B (6) in this order. An adhesive layer or bonding layer (not shown) can be provided between the thermoplastic resin substrate A (2) and the heat ray shielding layer (4), and between the heat ray shielding layer (4) and the thermoplastic resin substrate B (6), respectively. In addition, a dripping layer (not shown) can be provided on the outer side surface of at least one of the thermoplastic resin substrates (2, 6). Other layers such as a primer layer (not shown) can also be provided.

[0016] (Thermoplastic resin base materials A and B) Thermoplastic resin substrates A and B (collectively referred to as "thermoplastic resin substrates") are not particularly limited as long as they are substrates composed of thermoplastic resins. Thermoplastic resin substrates A and B preferably have high transparency, and their visible light transmittance is preferably 70% or higher, more preferably 85% or higher, and even more preferably 87% or higher, with high visible light transmittance being preferred.

[0017] Thermoplastic resin substrates A and B each independently preferably comprise at least one thermoplastic resin selected from polyolefin resins, polyvinyl chloride resins, polyethylene terephthalate resins, and fluororesins. From the perspective of improving the durability of the heat ray-shielding film, it is more preferable that at least one of the thermoplastic resin substrates A and B comprises a fluororesin. Both thermoplastic resin substrates A and B may comprise a fluororesin, or one of the thermoplastic resin substrates A or B may comprise a fluororesin while the other comprises a resin other than a fluororesin. From the perspective of further improving the durability of the heat ray-shielding film, it is preferable that both thermoplastic resin substrates A and B comprise a fluororesin. The fluororesin is preferably a thermoplastic resin.

[0018] The fluororesin is not particularly limited as long as it contains fluorine in its molecular structure, and known fluororesins can be used. For example, thermoplastic resins such as tetrafluoroethylene resins, chlorotrifluoroethylene resins, vinylidene fluoride resins, and vinyl fluoride resins can be mentioned. Among them, tetrafluoroethylene resins are preferred due to their excellent weather resistance and anti-fouling properties.

[0019] Examples of the tetrafluoroethylene-based resin include tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymers, tetrafluoroethylene-hexafluoropropylene-perfluoro(alkyl vinyl ether) copolymers, tetrafluoroethylene-hexafluoropropylene copolymers, tetrafluoroethylene-ethylene copolymers, and ethylene-trichlorofluoroethylene copolymers. Among them, tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymers, tetrafluoroethylene-hexafluoropropylene copolymers, tetrafluoroethylene-ethylene copolymers, and ethylene-trichlorofluoroethylene copolymers are preferred. Among them, tetrafluoroethylene-ethylene copolymers (hereinafter also referred to as "ETFE") are particularly preferred from the viewpoints of cost, mechanical strength, sputtering film-forming properties, etc.

[0020] ETFE is a copolymer having constituent units derived from ethylene (hereinafter also referred to as "E") (hereinafter also referred to as "E units") and constituent units derived from tetrafluoroethylene (hereinafter also referred to as "TFE") (hereinafter also referred to as "TFE units"). ETFE may further have constituent units derived from monomers other than E and TFE, as needed. The molar ratio of E unit / TFE unit in ETFE is preferably 40 / 60 to 70 / 30, more preferably 40 / 60 to 60 / 40. The total content of the E unit and the TFE unit in 100 mol % of all units constituting ETFE is preferably 90 mol % or more, more preferably 95 mol % or more, and may be 100 mol %.

[0021] As other monomers of ETFE, any monomer that can be copolymerized with E and TFE may be used. Examples include: fluorinated ethylenes such as CF2=CFCl and CF2=CH2; fluorinated propylenes such as CF2=CFCF3 and CF2=CHCF3; CH2=CHC2F5, CH2=CHC3F7, CH2=CHC4F9(PFBE), CH2=CFC4F9, CH2=CF(CF2)3H, CH2=CHC6F 13 Fluoroalkylethylene having a fluoroalkyl group with 2 to 10 carbon atoms; CF2=CFO(CF2CFXO) m R f (Where R f represents a perfluoroalkyl group having 1 to 6 carbon atoms, X represents a fluorine atom or a trifluoromethyl group, and m represents an integer from 1 to 5), etc. perfluoro(alkyl vinyl ether); and vinyl ethers having a group that can be converted into a carboxylic acid group or a sulfonic acid group, such as CF2=CFOCF2CF2CF2COOCH3, CF2=CFOCF2CF(CF3)OCF2CF2SO2F. As other monomers of ETFE, fluoroalkylethylene having a fluoroalkyl group of 2 to 10 carbon atoms or perfluoro(alkyl vinyl ether) are preferred, fluoroalkylethylene having a fluoroalkyl group of 2 to 10 carbon atoms are more preferred, and CH2=CHC3F7, CH2=CHC4F9, or CH2=CHC6F are further preferred. 13 , CH2=CHC4F9 is particularly preferred.

[0022] When ETFE has other monomer units, the content of the other monomer units in 100 mol % of all units constituting ETFE is preferably 0.01 to 10 mol %, more preferably 0.05 to 5 mol %, and even more preferably 0.1 to 4 mol %.

[0023] The melting point of ETFE is preferably 200° C. or higher, more preferably 210° C. or higher, further preferably 225° C. or higher, and particularly preferably 240° C. or higher. When the melting point of ETFE is within this range, the heat ray shielding film of the present disclosure tends to have excellent durability. The upper limit of the melting point of ETFE is not particularly limited, but is, for example, 270°C. The "melting point" refers to the temperature corresponding to the maximum of the melting peak measured by differential scanning calorimetry (DSC).

[0024] The melt flow rate (MFR) of ETFE is preferably 2 to 40 g / 10 minutes, more preferably 5 to 30 g / 10 minutes, and further preferably 10 to 20 g / 10 minutes. When the MFR of ETFE is within this range, the heat ray-shielding film of the present disclosure tends to be excellent in durability. The MFR of ETFE is a value measured under conditions of a load of 49 N and 297° C. in accordance with ASTM D3159.

[0025] Thermoplastic resin substrates A and B may each independently contain an ultraviolet absorber. Examples of the ultraviolet absorber include the ultraviolet absorbers described for the adhesive layer and the bonding agent layer. When the thermoplastic resin substrate contains an ultraviolet absorber, the ultraviolet absorber can be mixed with the thermoplastic resin to obtain the thermoplastic resin substrate A or B. When the thermoplastic resin substrate contains an ultraviolet absorber, the content of the ultraviolet absorber in the thermoplastic resin substrate is preferably 0.1 to 1.5% by mass, and more preferably 0.3 to 0.8% by mass.

[0026] From the perspective of easily improving the durability of the heat ray shielding film, the content of the thermoplastic resin contained in the thermoplastic resin substrates A and B is preferably 60% by mass or more, more preferably 80% by mass or more, and even more preferably 95% by mass or more. The content of the thermoplastic resin contained in the thermoplastic resin substrates A and B may be 100% by mass. From the perspective of easily improving the durability of the heat ray shielding film, the content of the fluororesin contained in the thermoplastic resin substrates A and B is preferably 60% by mass or more, more preferably 80% by mass or more, and even more preferably 95% by mass or more. The content of the fluororesin contained in the thermoplastic resin substrates A and B may be 100% by mass. From the viewpoint of easily improving the durability of the heat ray shielding film, the content of ETFE contained in the thermoplastic resin substrates A and B is preferably 60% by mass or more, more preferably 80% by mass or more, and further preferably 95% by mass or more, respectively. The content of ETFE contained in the thermoplastic resin substrates A and B may be 100% by mass.

[0027] The shapes of the thermoplastic resin substrates A and B are not particularly limited, and each may independently be in any shape such as a plate, a sheet, or a film.

[0028] The thickness of thermoplastic resin substrates A and B is not particularly limited and can be appropriately selected depending on the material, application, shape, etc. For example, in the case of a plate-like thermoplastic resin substrate, the average thickness is preferably 2 mm to 50 mm, more preferably 2 mm to 20 mm. Furthermore, in the case of a film-like or sheet-like thermoplastic resin substrate, the average thickness is preferably 10 μm to 1 mm, more preferably 12 μm to 300 μm, and even more preferably 20 μm to 200 μm. The average thickness of the thermoplastic resin substrate is the average of values ​​measured at five locations using a micrometer. The thickness of the thermoplastic resin substrate A and the thickness of the thermoplastic resin substrate B may be the same as or different from each other.

[0029] (Heat ray shielding layer) The heat ray shielding layer contains a binder resin and inorganic particles. Examples of the inorganic component contained in the inorganic particles include indium tin oxide, antimony tin oxide, indium zinc oxide, and composite tungsten oxide, with indium tin oxide being preferred. Indium tin oxide is a composite oxide (inorganic mixture) containing a small amount of tin oxide (SnO2) in indium oxide (In2O3). In addition, as an inorganic component, transition metal-doped indium oxide is preferred. Examples include tin-doped indium oxide (ITO), zinc-doped indium oxide (IZO), tungsten-doped indium oxide, and tantalum-doped indium oxide. As inorganic components, tin-doped indium oxide and tungsten-doped indium oxide are preferred, with tin-doped indium oxide being more preferred. Tin-doped indium oxide and tungsten-doped indium oxide have relatively high refractive indices and are therefore effective in reducing solar transmittance.

[0030] The molar ratio of tin in indium tin oxide to the total amount of tin and indium [Sn / (Sn+In)] is preferably 0.01 to 0.15, more preferably 0.04 to 0.12.

[0031] From the viewpoint of improving the transparency (transmittance of visible light) of the heat ray shielding film, the average primary particle size of the inorganic particles is preferably 0.2 μm or less, and more preferably 0.1 μm or less. The average primary particle size of the inorganic particles can be calculated from the measured value of the specific surface area (BET) based on the following particle size formula. a(μm)=6 / (ρ×B) [a: average primary particle size, ρ: true specific gravity, B: specific surface area (m 2 / g)] The average primary particle size determined from the specific surface area was confirmed to be substantially the same as the average particle size observed directly by transmission electron microscopy. The specific surface area by the BET method was measured using an automatic specific surface area measuring apparatus (eg, BELSORP manufactured by Microtrac BEL).

[0032] The content of inorganic particles in the heat ray shielding layer is preferably 50% by mass or more, more preferably 60% by mass or more, and further preferably 70% by mass or more. Furthermore, the content of inorganic particles in the heat ray shielding layer is preferably 95% by mass or less, and more preferably 90% by mass or less.

[0033] As binder resin, there is no particular limitation, and conventional organic resins for clear coatings can be used, preferably resins with excellent transparency. As binder resin, acrylic resin, polycarbonate resin, polyvinyl chloride resin, polyurethane resin, melamine resin, alkyd resin, polyester resin, epoxy resin etc. can be listed. Binder resin can be used alone or in combination of two or more. Wherein, as binder resin, preferably the cured product of ultraviolet curable resin, more preferably the cured product of acrylic ultraviolet curable resin.

[0034] The content of the binder resin is preferably 2 to 200 parts by mass, more preferably 12 to 100 parts by mass, and even more preferably 15 to 80 parts by mass, based on 100 parts by mass of the inorganic particles.

[0035] The heat ray shielding layer may further comprise other components. Examples of such other components include solvents, dispersants, UV curing initiators, and leveling agents. When a coating liquid is used to form the heat ray shielding layer, the solvent used in the coating liquid is removed by drying, but may remain in the heat ray shielding layer. Furthermore, a resin binder precursor such as a UV curable resin may also remain.

[0036] The solvent may be any solvent capable of dissolving or dispersing the resin binder or resin binder precursor, and includes aromatic hydrocarbons such as benzene, toluene, and xylene; alicyclic hydrocarbons such as cyclohexane; aliphatic hydrocarbons such as hexane and octane; ethers, ketones, or esters such as diacetone alcohol, diethylene glycol, butyl carbitol, isophorone, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, and ethyl acetate; halogenated hydrocarbons such as dimethylformamide, butyl carbitol acetate, and diethanolamine; and monohydric or polyhydric alcohols such as methanol, ethanol, propanol, 2-propanol, butanol, 2-methyl-1-propanol, and ethylene glycol. These solvents may be used alone or in combination.

[0037] The total amount of the binder resin and the inorganic particles in the heat ray shielding layer is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 98% by mass or more. The total amount of the binder resin and the inorganic particles in the heat ray shielding layer may be 100% by mass.

[0038] The average thickness of the heat ray shielding layer is preferably 1 μm or less, more preferably 0.9 μm or less, and further preferably 0.8 μm or less. The average thickness of the heat ray shielding layer is measured by the same method as the average thickness of the substrate.

[0039] The heat ray shielding layer can be formed by applying a coating liquid containing inorganic particles, a binder resin (or a binder resin precursor), a solvent, and any other components contained therein. The coating liquid may be a dispersion or a solution. The content of the solvent in the coating liquid is set so that a viscosity suitable for a layer formation method applicable to coating, printing, etc. can be obtained. Typically, 10 to 100 parts by mass of the solvent is contained relative to 100 parts by mass of the inorganic particles, but this is not limited thereto. The content of any other components contained therein is also appropriately adjusted.

[0040] As a coating method for the coating liquid, a wet coating method can be mentioned. Examples of wet coating methods include spin coating, rod coating, and relief coating. Among them, spin coating and micro relief coating, which can apply a small amount of coating, are preferred.

[0041] After the coating liquid is applied, the solvent is removed by drying. When an ultraviolet curable resin is used as the binder resin precursor, the ultraviolet curable resin is cured by irradiation with ultraviolet rays to form a heat ray shielding layer.

[0042] (Adhesive layer and bonding layer) The heat ray shielding film may have an adhesive layer or a bonding layer between at least one of the heat ray shielding layer and the thermoplastic resin substrate A and between the heat ray shielding layer and the thermoplastic resin substrate B.

[0043] The adhesive layer can be formed with a known adhesive, preferably an acrylic adhesive. The adhesive layer preferably contains an acrylic resin. The acrylic resin is a polymer obtained by polymerizing a monomer containing at least one acrylic monomer selected from acrylic acid, methacrylic acid, and derivatives thereof. As the acrylic resin, those known as pressure-sensitive adhesives and pressure-sensitive adhesives can be used. The acrylic resin preferably has a glass transition temperature (Tg) in the range of -100 to +50° C. When an acrylic resin having a Tg in the above range is used, excellent adhesion is achieved in a conventional temperature range. From the viewpoint of adhesiveness, the acrylic adhesive preferably contains at least one acrylic resin having a number average molecular weight of 500,000 or greater, and more preferably contains at least one acrylic resin having a number average molecular weight of 800,000 or greater.

[0044] The acrylic adhesive may contain an acrylic monomer in addition to the acrylic resin. Examples of the acrylic monomer include those mentioned above. Alternatively, the acrylic adhesive may be a two-component acrylic adhesive composed of a base component containing an acrylic resin having functional groups that serve as crosslinking points, and a crosslinking agent that reacts with the crosslinking points.

[0045] The main acrylic resin is preferably a copolymer obtained by copolymerizing monomers A and B in a ratio such that the Tg falls within the above range, wherein monomer A is composed of at least one alkyl acrylate (alkyl group having 2 to 12 carbon atoms) such as ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-pentyl acrylate, 2-methylbutyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, n-nonyl acrylate, and isononyl acrylate, and monomer B is composed of at least one functional group-containing acrylic monomer such as acrylic acid, methacrylic acid, acrylamide, N-hydroxymethyl acrylamide, 2-hydroxyethyl acrylate, and 2-hydroxyethyl methacrylate. The copolymerization ratio of monomers A to B is preferably 99.1 / 0.9 to 70 / 30, more preferably 99.5 / 0.5 to 70 / 30, further preferably 99 / 1 to 75 / 25, and can be 99.5 / 0.5 to 80 / 20, based on the mass ratio of monomers A to B.

[0046] Particularly preferred examples of acrylic resins composed of a copolymer of monomer A and monomer B include copolymers obtained by copolymerizing butyl acrylate (BA) and acrylic acid (AA) at a BA / AA mass ratio within a range of 99.1 / 0.9 to 70 / 30, preferably 99.5 / 0.5 to 80 / 20.

[0047] The main agent composed of such a copolymer is commercially available, for example, SK-2094, SK-1310, and SK-1386 (all manufactured by Soken Chemical Co., Ltd.) are listed below. SK-2094 (solids content 25% by mass) is a mixture of an acrylate copolymer (BA / AA = 96 / 4 (mass ratio)) and a methacrylate copolymer. This mixture has a number-average molecular weight of 800,000 and a Tg of -30 to -25°C. It is known to contain 20 to 30% by mass of this mixture, 60 to 70% by mass of ethyl acetate, 1 to 10% by mass of toluene, 1 to 10% by mass of methyl ethyl ketone, 1 to 10% by mass of butyl acrylate, and less than 1% by mass of methyl acrylate. It is known that SK-1310 (solid content 33% by mass) contains 30-40% by mass of an acrylic acid ester copolymer (BA / AA = 90 / 10 (mass ratio), number average molecular weight: 500,000, Tg: -50 to -45°C), 40-50% by mass of ethyl acetate, and 20-30% by mass of toluene. It is known that SK-1386 (solid content 35% by mass) contains 30-40% by mass of an acrylic acid ester copolymer (BA / AA = 92 / 8 (mass ratio), number average molecular weight: 500,000, Tg: -50 to -45°C), 30-40% by mass of ethyl acetate, and 20-30% by mass of toluene.

[0048] Examples of cross-linking agents include: epoxy cross-linking agents having two or more epoxy groups (for example, manufactured by Soken Chemical Co., Ltd., trade name: E-AX); metal chelate cross-linking agents such as aluminum chelates (for example, manufactured by Soken Chemical Co., Ltd., trade name: M-5A); polyisocyanate cross-linking agents having two or more isocyanate groups (for example, manufactured by Soken Chemical Co., Ltd., trade name: L-45), etc. The cross-linking agent is appropriately selected according to the type of functional group that will become a cross-linking point. Among them, epoxy cross-linking agents and metal chelate cross-linking agents are preferred. Epoxy cross-linking agents and metal chelate cross-linking agents have a long pot life and a slow increase in adhesion after bonding. Therefore, the fluororesin adhesive film has excellent operability such as re-adhesiveness and is not easy to discolor in a weather resistance test.

[0049] The adhesive layer can be formed with a known adhesive, preferably a polyurethane adhesive. The adhesive layer preferably contains a polyurethane resin. The polyurethane resin is preferably a polyurethane resin made from a polycarbonate polyol (a1). The polyurethane resin is preferably a polyurethane resin (A1) obtained by reacting a polycarbonate polyol (a1), an alkylene glycol chain extender (a2) (hereinafter sometimes referred to as "chain extender (a2)"), and an organic diisocyanate (a3), or a polyurethane resin (A2) obtained by reacting a polycarbonate polyol (a1) with an organic diisocyanate (a3).

[0050] Examples of the polycarbonate polyol (a1) include polycarbonate polyols obtained by reacting a diol with a short-chain dialkyl carbonate. Examples of short-chain dialkyl carbonates include dialkyl carbonates having an alkyl group having 1 to 4 carbon atoms, such as dimethyl carbonate and diethyl carbonate. The alkyl group of the dialkyl carbonate may be a linear or branched structure. The short-chain dialkyl carbonates may be used alone or in combination of two or more. As a diol, from the point of improving the adhesive strength, a diol with a branched alkyl side chain is preferably used. As a diol with a branched alkyl side chain, for example, 2-methyl-1,3-propylene glycol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propylene glycol, etc. can be mentioned. In addition to the diol with a branched alkyl side chain, diols without a branched alkyl side chain such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol can also be used. One diol can be used alone or in combination of two or more.

[0051] From the viewpoint of adhesive strength, the proportion of the structural units derived from the diol having a branched alkyl side chain in the polycarbonate polyol (a1) is preferably 20 mol% or more, more preferably 30 mol% or more, based on the total amount of structural units derived from the diol.

[0052] The weight-average molecular weight of the polycarbonate polyol (a1) is preferably 400 to 8,000, more preferably 700 to 5,000. When the weight-average molecular weight is above the lower limit, solubility in practical synthetic solvents is improved. When the weight-average molecular weight is below the upper limit, sufficient adhesive strength is easily obtained, thereby improving practicality.

[0053] The hydroxyl value of the polycarbonate polyol (a1) is preferably 14 to 280 mg / KOH, more preferably 22 to 160 mg / KOH. When the hydroxyl value of the polycarbonate polyol (a1) is at least the lower limit, the crosslinking reaction proceeds readily, the molecular weight distribution of the product becomes narrower, and the hydrolysis resistance after crosslinking becomes better. Furthermore, when the hydroxyl value of the polycarbonate polyol (a1) is at most the upper limit, a flexible adhesive layer is readily obtained.

[0054] Examples of the chain extender (a2) include the same diols as those exemplified as the diols for forming the polycarbonate polyol (a1). From the viewpoint of improving the adhesive strength, diols having a branched alkyl side chain are preferred. The molecular weight of the chain extender (a2) is preferably 62 to 400. Preferred examples of the chain extender (a2) include ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-pentanediol, 1,6-hexanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, and 2-butyl-2-ethyl-1,3-propanediol.

[0055] From the viewpoint of adhesive strength, the proportion of the structural units derived from the diol having a branched alkyl side chain in the chain extender (a2) relative to the total amount of the structural units derived from the diol is preferably 5 mol% or more, more preferably 20 mol% or more.

[0056] Examples of the organic diisocyanate (a3) ​​include aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and mixtures of two or more thereof. Examples of the aromatic diisocyanate include diphenylmethane diisocyanate, tetramethylxylylene diisocyanate, xylylene diisocyanate, toluene diisocyanate, and prepolymers of these aromatic diisocyanates with small molecular weight diols. Examples of the aliphatic diisocyanate include 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, and prepolymers of these aliphatic diisocyanates with small molecule diols such as ethylene glycol and propylene glycol. Examples of the alicyclic diisocyanate include isophorone diisocyanate, hydrogenated 4,4′-diphenylmethane diisocyanate, methylcyclohexyl diisocyanate, isopropylidene dicyclohexyl-4,4′-diisocyanate, and prepolymers of these alicyclic diisocyanates with small molecule diols.

[0057] As the organic diisocyanate (a3), aliphatic or alicyclic diisocyanates such as hydrogenated 4,4′-diphenylmethane diisocyanate, isophorone diisocyanate, and 2,2,4-trimethylhexamethylene diisocyanate are preferred because of their excellent weather resistance.

[0058] The polyurethane resin preferably has a hydroxyl group at the terminal. In the polyurethane resin (A1), the equivalent ratio (NCO / OH) of the hydroxyl groups of the polycarbonate polyol (a1) and the chain extender (a2) to the isocyanate groups of the organic diisocyanate (a3) ​​is preferably 0.7 to 0.99, more preferably 0.8 to 0.97. When the NCO / OH ratio is above the lower limit, the adhesive strength and heat resistance are improved, while when it is below the upper limit, a main agent having a sufficient number of terminal hydroxyl groups is easily obtained.

[0059] In the case of the polyurethane resin (A1), the amount of the chain extender (a2) used is preferably 0.5 to 50 parts by mass per 100 parts by mass of the polycarbonate polyol (a1). When the amount of the chain extender (a2) used is at least the lower limit, the adhesive strength is improved, while when it is at most the upper limit, the solubility in the synthetic solvent described below is improved.

[0060] In the polyurethane resin (A2), the equivalent ratio of the hydroxyl groups of the polycarbonate polyol (a1) to the isocyanate groups of the organic diisocyanate (a3): NCO / OH, is preferably 0.7 to 0.99. When the NCO / OH ratio is above the lower limit, adhesive strength and heat resistance are improved, while when it is below the upper limit, a base resin having a sufficient number of terminal hydroxyl groups is easily obtained.

[0061] The hydroxyl value of the polyurethane resin is preferably 3 to 20 mg / KOH, more preferably 5 to 10 mg / KOH. When the hydroxyl value of the polyurethane resin is above the lower limit, a cross-linking reaction with the isocyanate used as a two-component curing agent is expected. When the hydroxyl value is below the upper limit, the cross-linking reaction with the isocyanate used as a two-component curing agent tends to occur uniformly in a relatively short period of time.

[0062] The weight average molecular weight of the polyurethane resin is preferably 4,000 to 50,000, more preferably 8,000 to 15,000. When the weight average molecular weight of the polyurethane resin is at least the lower limit, the adhesive strength is improved, while when it is at most the upper limit, the solubility in the synthetic solvent described below is improved, resulting in excellent processability.

[0063] The reaction of polycarbonate polyol (a1), chain extender (a2), and organic diisocyanate (a3) ​​can be carried out without a solvent or in a synthetic solvent that is non-reactive with isocyanate groups. Alternatively, the reaction can be carried out in the presence of a catalyst, if desired. The reaction temperature is preferably 60 to 150°C, and the reaction time is preferably 2 to 15 hours.

[0064] Examples of the above-mentioned synthesis solvents that are non-reactive with isocyanate groups include esters such as ethyl acetate, butyl acetate, and cellosolve acetate; ketones such as acetone, methyl ethyl ketone, isobutyl ketone, and cyclohexanone; ethers such as tetrahydrofuran and dioxane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methyl chloride and ethyl chloride; and sulfur-containing compounds such as dimethyl sulfoxide and dimethylsulfonamide. These synthesis solvents can also be used as dilution solvents after the synthesis of the main agent. The polyurethane resin may be used alone or in combination of two or more.

[0065] Examples of the curing agent for the polyurethane resin include polyisocyanates. Examples of the polyisocyanates include adducts of the diisocyanates listed for the organic diisocyanate (a3) ​​and polyols, isocyanurates, biuret forms, allophanates, and polyisocyanates having two or more isocyanate groups in one molecule. Specific examples include polyfunctional organic polyisocyanates such as an adduct obtained by adding 3 mol of diisocyanate to 1 mol of trimethylolpropane, a biuret obtained by reacting 3 mol of diisocyanate with 1 mol of water, and an isocyanurate obtained by polymerizing 3 mol of diisocyanate. The curing agent is preferably an isocyanurate containing an isocyanurate ring structure and having an isocyanate group content of 10% to 28% by mass. The curing agent is particularly preferably an urea ester of isophorone diisocyanate (IPDI) and / or hexamethylene diisocyanate (HDI).

[0066] The curing agent may be a blocked isocyanate in which isocyanate groups are blocked. Isocyanate groups can be blocked using ε-caprolactam (E-CAP), methyl ethyl ketone oxime (MEK-OX), methyl isobutyl ketone oxime (MIBK-OX), pyrazine, triazine (TA), and the like. The curing agent may be used alone or in combination of two or more.

[0067] The adhesive layer and the bonding layer may contain a UV absorber. By including a UV absorber in the adhesive layer or the bonding layer, degradation of the adhesive layer or the bonding layer during long-term use can be suppressed. Furthermore, by positioning the adhesive layer or the bonding layer containing a UV absorber closer to the sunlight side than the heat ray shielding layer, the amount of UV rays incident on the heat ray shielding layer can be reduced, thereby suppressing degradation of the heat ray shielding layer during long-term use.

[0068] When the adhesive layer or the bonding layer contains a UV absorber, at least one of the adhesive layer or the bonding layer between the heat ray shielding layer and the thermoplastic resin substrate A and between the heat ray shielding layer and the thermoplastic resin substrate B may contain a UV absorber. Only one or both may contain a UV absorber.

[0069] The UV absorber is not particularly limited, but preferably contains a triazine-based UV absorber. One UV absorber may be used alone or in combination of two or more. The content of the triazine-based UV absorber in the total amount of the UV absorber is preferably 80% by mass or greater, more preferably 90% by mass or greater, further preferably 95% by mass or greater, and particularly preferably 99% by mass or greater.

[0070] As the triazine-based ultraviolet absorber, a triazine derivative known as an ultraviolet absorber can be used, or a commercially available product can be purchased. Preferred triazine-based ultraviolet absorbers include the following hydroxyphenyltriazine-based ultraviolet absorbers. 2-(2-Hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine (commercially available product: TINUVIN 479, manufactured by BASF Japan Ltd.) 2,4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3,5-triazine (chemical formula (1) below, commercially available under the trade name TINUVIN 460 manufactured by BASF Japan Ltd.) 2-[4-[(2-hydroxy-3-(2'-ethyl)hexyloxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine (chemical formula (2) below, commercially available product: TINUVIN 405 manufactured by BASF Japan Ltd.) TINUVIN 477, manufactured by BASF Japan Co., Ltd., is a product described on page 10 of BASF Japan Co., Ltd.'s "Paint Additives Handbook" (Pub. No. CJ-005, published in March 2008). It is a mixture of approximately 80% of a hydroxyphenyltriazine-based UV absorber (of an undisclosed structure) and approximately 20% of 1-methoxy-2-propyl acetate (of an undisclosed structure). TINUVIN 400, a trade name manufactured by BASF Japan. This product is described on page 7 of the "Handbook of Coating Additives" and is known to be a reaction product of 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl)-5-hydroxyphenyl and [(C10-C16, mainly C12-C13 alkyloxy)methyl]ethylene oxide (chemical formula (3) below).

[0071]

Chemical Formula 1

[0072]

Chemical Formula 2

[0073]

Chemical Formula 3

[0074] Furthermore, as preferred triazine-based ultraviolet absorbers other than the hydroxyphenyltriazine-based ultraviolet absorbers, the following compounds can be mentioned. 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl]-5-(octyloxy)phenol (commercially available product: CYASORB UV-1164, manufactured by San Chemical Co., Ltd.) 2-[2,6-Bis(2,4-xylyl)-1,3,5-triazin-2-yl]-5-octyloxyphenol (commercially available under the trade name KEMISORB 102, manufactured by Chemipro Chemicals Co., Ltd.)

[0075] The content of the ultraviolet absorber in the adhesive layer or the bonding layer is preferably appropriately set. For example, although the content varies depending on the thickness of the adhesive layer or the bonding layer, for example, an adhesive layer using an acrylic adhesive or a bonding layer using a polyurethane adhesive may contain 3 to 10 parts by mass of the ultraviolet absorber per 100 parts by mass of the solid content of the acrylic adhesive or the polyurethane adhesive.

[0076] The adhesion layer or adhesive layer may further contain a light stabilizer. Preferred light stabilizers include hindered amine light stabilizers and hindered phenol light stabilizers. Light stabilizers may be used alone or in combination of two or more. These may be known or commercially available.

[0077] As examples of hindered amine light stabilizers, the following ones can be cited. Bis(1,2,2,6,6-pentamethyl-4-piperidinyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butyl malonate (chemical formula (4) below, commercially available under the trade name TINUVIN 144 manufactured by BASF Japan Ltd.) · Trade name: TINUVIN 123, manufactured by BASF Japan. This product is described on page 16 of the "Handbook of Coating Additives" and is known to be a reaction product of bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl) sebacate (1,1-dimethylethyl peroxide) and octane (chemical formula (5) below).

[0078]

Chemical Formula 4

[0079]

Chemical Formula 5

[0080] Examples of hindered phenolic light stabilizers include pentaerythritol tetrakis-[3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate] (chemical formula (6) below, commercially available under the trade name IRGANOX 1010 manufactured by BASF Japan Ltd.).

[0081]

Chemical Formula 6

[0082] When the adhesive layer or the pressure-sensitive adhesive layer contains a light stabilizer, the content of the light stabilizer is appropriately set. For example, in an adhesive layer using an acrylic pressure-sensitive adhesive or a pressure-sensitive adhesive layer using a polyurethane pressure-sensitive adhesive, the content is preferably 0.1 to 4.0 parts by mass, and more preferably 0.5 to 2.0 parts by mass, relative to 100 parts by mass of the solid content of the acrylic pressure-sensitive adhesive or the polyurethane pressure-sensitive adhesive.

[0083] (Drip layer) The heat ray shielding film preferably has a dripping layer on the outer side of at least one of the thermoplastic resin substrate A and the thermoplastic resin substrate B. When the heat ray shielding film is used in an agricultural greenhouse, it is preferred that the dripping layer be provided on the surface of at least the thermoplastic resin substrate disposed on the layer inside the agricultural greenhouse.

[0084] The drip layer is used to prevent water vapor generated by plants, animals, and soil from condensing on the membrane surface and forming large water droplets. The drip layer prevents condensed water vapor from forming jade-like droplets on the membrane surface. As the water film disperses, it less likely blocks sunlight transmission. In greenhouses constructed with agricultural film equipped with a dripping agent, the film's surface temperature rises during sunny and cloudy winter days, reducing condensation and eliminating it quickly. Therefore, when agricultural film equipped with a dripping agent is deployed in greenhouses, it also achieves high visible light transmittance, which is necessary for photosynthesis. Furthermore, agricultural film equipped with a dripping agent prevents condensation not only during the day but also at night when the surface temperature drops.

[0085] The dripping layer can be formed by a dripping agent. There is no particular limitation on the dripping agent, and known ones can be used. As the dripping agent, for example, hydrophilic inorganic particles such as silicon oxide particles and aluminum oxide particles (average particle size of about 0.01 μm) are preferably included, and a mixture of silicon oxide particles and boehmite particles is more preferably used. As the dripping agent, a dripping agent formed by dispersing inorganic particles in a silane coupling agent or a binder such as polyvinyl alcohol (PVA) is generally used. The dripping agent can contain a solvent such as ion exchange water. In addition, a pH regulator such as nitric acid can be included. Examples of the dripping agent include the composition described in Japanese Patent Application Laid-Open No. 2007-099884.

[0086] The amount of dripping agent applied is preferably such that the solid content of the film reaches 0.2 to 1.0 g / m 2 About the amount. The water contact angle of the dripping layer surface is preferably 40 degrees or less, more preferably 5 to 20 degrees.

[0087] When a dripping layer is provided, in order to improve the coating property of the dripping agent, the thermoplastic resin substrate to which the dripping agent is applied is preferably subjected to a surface treatment. The surface treatment is not particularly limited, and examples thereof include corona discharge treatment, plasma discharge treatment, ozone treatment, flame treatment, chemical conversion treatment, and primer treatment. As the surface treatment, corona discharge treatment is more preferably used. The primer treatment can also be performed using a primer treatment liquid. The primer treatment liquid preferably contains aminosilane. The primer treatment liquid may further contain a leveling agent, a solvent, etc.

[0088] (Physical properties of heat ray shielding film, etc.) The heat ray-shielding film of the present disclosure preferably has a visible light transmittance of 85% or greater, more preferably 87% or greater. While a higher visible light transmittance is preferred, a visible light transmittance of 85% or greater provides excellent transparency, effectively promoting the growth of cultivated plants when used in agricultural greenhouses, for example. The heat ray shielding film of the present disclosure has a visible light transmittance of 100% or less. The visible light transmittance disclosed herein refers to the ratio of the transmitted light beam to the incident light beam in a daylight beam perpendicularly incident on the surface of a substrate such as glass. Daylight refers to the CIE daylight specified by the International Commission on Illumination (CIE for short). CIE daylight is expressed as the relative value of the spectral illuminance distribution of daylight with a color temperature identical to that of blackbody radiation relative to a wavelength of 560 nm based on observation data. In addition, the light beam is obtained by integrating the value of the product of the radiation beam of each wavelength radiated and the value of visual sensitivity over the wavelength (refer to Japanese Industrial Standards JIS Z 8113: 1998 and JIS Z 8120: 2001). The visible light transmittance is measured in accordance with DIN EN410 1998.

[0089] The solar transmittance of the heat ray-shielding film of the present disclosure is preferably 82% or less, more preferably 80% or less. While a lower solar transmittance is preferred, a solar transmittance of 82% or less can shield sunlight and suppress increases in indoor temperature. To prevent excessive drops in indoor temperature during winter, the solar transmittance of the heat ray-shielding film is preferably 70% or more, more preferably 72% or more. The solar transmittance in this disclosure refers to the ratio of the transmitted radiation beam to the incident radiation beam, measured perpendicularly to the surface of a substrate such as glass. Furthermore, solar transmittance refers to direct sunlight, meaning radiation in the near-ultraviolet, visible, and near-infrared wavelengths (300-2500 nm) that passes through the atmosphere and directly reaches the Earth's surface. Solar transmittance is measured in accordance with DIN EN 410:1998.

[0090] The heat-ray-shielding film disclosed herein preferably has a solar transmittance of 80% or less, more preferably 75% or less, after exposure. While a lower solar transmittance after exposure is preferred, a solar transmittance of 82% or less can shield sunlight and suppress increases in indoor temperatures during long-term use. To prevent excessive drops in indoor temperatures during wintertime during long-term use, the heat-ray-shielding film preferably has a solar transmittance of 70% or more, more preferably 72% or more, after exposure. The exposure treatment in the present disclosure refers to exposure for 5000 hours under an open carbon arc lamp in accordance with JIS K7350-4:2008.

[0091] The heat-shielding film disclosed herein preferably has a solar transmittance after exposure to a solar transmittance before exposure of 1.05 or less, and more preferably has a solar transmittance before exposure of 1.01 or less. When the ratio of the solar transmittance after exposure to the solar transmittance before exposure is low, the increase in solar transmittance is suppressed, and the heat-shielding film disclosed herein exhibits excellent long-term heat-shielding properties. From the perspective of suppressing an excessive drop in indoor temperature during winter use over a long period of time, the ratio of the solar transmittance after exposure to the solar transmittance before exposure is preferably 0.95 or greater.

[0092] The heat ray shielding film of the present disclosure preferably has a value of (visible light transmittance−solar light transmittance) / visible light transmittance×100 of 10% or more, more preferably 15% or more, and still more preferably 17.5% or more. Although it is preferable that the visible light transmittance value is large and the difference between the visible light transmittance value and the solar light transmittance value is large, when the value is 10% or more, the visible light transmittance and the heat ray shielding property are excellent. The heat ray shielding film of the present disclosure preferably has a value of (visible light transmittance−solar light transmittance) / visible light transmittance×100 of 25% or less, more preferably 20% or less.

[0093] The heat ray shielding film of the present disclosure preferably has a value of (visible light transmittance - solar light transmittance) / visible light transmittance × 100 of 10% or more, and a ratio of solar light transmittance after exposure to solar light transmittance before exposure of 1.05 or less. Since the heat ray shielding film of the present disclosure is excellent in visible light transmittance, heat ray shielding properties, and weather resistance, the value of (visible light transmittance - solar light transmittance) / visible light transmittance × 100 and the ratio of the solar light transmittance after exposure treatment to the solar light transmittance before exposure treatment are easily within the above ranges.

[0094] The lower limit of the haze of the heat ray shielding film of the present disclosure is 0%. The haze of the heat ray shielding film of the present disclosure is preferably 15% or less, more preferably 10% or less. The lower the haze, the better the appearance. In the present disclosure, haze is measured in accordance with DIN EN 410:1998.

[0095] The lower limit of the haze of the heat ray shielding film of the present disclosure after the exposure treatment is 0%. The haze of the heat ray shielding film of the present disclosure after the exposure treatment is preferably 25% or less, more preferably 15% or less, and further preferably 10% or less. In this case, the heat ray shielding film of the present disclosure has excellent long-term durability.

[0096] The heat-ray-shielding film of the present disclosure preferably has a haze ratio of 4.00 or less after exposure to the haze before exposure, more preferably 1.20 or less, and even more preferably 1.15 or less. When the haze ratio after exposure to the haze before exposure is low, the increase in fogging is suppressed, and the heat-ray-shielding film of the present disclosure exhibits excellent long-term durability. The haze ratio after exposure to the haze before exposure is preferably 0.90 or greater.

[0097] At least one surface of the heat-ray-shielding film disclosed herein may be provided with a concave-convex structure. This structure allows sufficient light to reach crops near the ground surface. This heat-ray-shielding film is particularly useful in winter, where morning sunshine is short and weak, leading to insufficient light.

[0098] The arithmetic mean roughness Ra of the surface having a concavo-convex structure is preferably 0.3 to 3.0 μm, more preferably 0.8 to 3.0 μm, and even more preferably 1.0 to 2.5 μm. Furthermore, the depth of the concavo-convex structure may be set shallower, in which case the Ra is preferably 0.3 to 2.0 μm, more preferably 0.8 to 1.8 μm, and even more preferably 1.0 to 1.6 μm. Alternatively, the depth of the concavo-convex structure may be set deeper, in which case the Ra is preferably 0.6 to 3 μm, more preferably 1.7 to 3 μm, and even more preferably 1.8 to 2.5 μm.

[0099] The maximum height roughness Rz of the surface having a concavo-convex structure is preferably 1 to 25 μm, more preferably 4 to 25 μm, and even more preferably 4 to 22 μm. When the depth of the concavo-convex structure is set to be shallow, Rz is preferably 1 to 8 μm, more preferably 4 to 7 μm, and even more preferably 4 to 6 μm. Furthermore, when the depth of the concavo-convex structure is set to be deep, Rz is preferably 13 to 25 μm, more preferably 15 to 25 μm, and even more preferably 18 to 22 μm.

[0100] The arithmetic mean roughness Ra and the maximum height roughness Rz are values ​​measured according to the method described in JIS B0601: 2013 (ISO 4287: 1997, Amd. 1: 2009).

[0101] Examples of the layer configuration of the heat ray-shielding film of the present disclosure are listed below, but the layer configuration of the heat ray-shielding film of the present disclosure is not limited thereto. (1) Thermoplastic resin base material A / heat ray shielding layer / thermoplastic resin base material B (2) Thermoplastic resin base material A / heat ray shielding layer / thermoplastic resin base material B / dripping layer (3) Thermoplastic resin base material A / adhesive layer or adhesive layer / heat ray shielding layer / thermoplastic resin base material B (4) Thermoplastic resin base material A / adhesive layer or adhesive layer / heat ray shielding layer / thermoplastic resin base material B / dripping layer (5) Thermoplastic resin base material A / heat ray shielding layer / adhesive layer or bonding layer / thermoplastic resin base material B / dripping layer

[0102] When a dripping layer is provided on the thermoplastic resin substrate B as in the layer configurations (2), (4) and (5), a primer layer (primer treatment layer) is preferably provided between the thermoplastic resin substrate B and the dripping layer.

[0103] When the heat ray shielding film having a dripping layer is applied to an agricultural greenhouse as in the layer configurations (2), (4), and (5), the dripping layer may be arranged on either the indoor side or the sunlight side. When an adhesive layer or bonding layer is provided as in layer configurations (3) to (5) and the adhesive layer or bonding layer contains an ultraviolet absorber, the adhesive layer or bonding layer may be arranged on either the indoor side or the sunlight side relative to the heat ray shielding layer. If the heat ray shielding film is provided so that the adhesive layer or bonding layer is closer to the sunlight side than the heat ray shielding layer, that is, the thermoplastic resin substrate A side is the sunlight side, damage to the heat ray shielding layer due to ultraviolet rays is suppressed. If the heat ray shielding film is provided so that the adhesive layer or bonding layer is closer to the indoor side than the heat ray shielding layer, that is, the thermoplastic resin substrate B side is the sunlight side, damage to the adhesive layer or bonding layer due to ultraviolet rays is suppressed. When one of the thermoplastic resin substrates A or B contains a fluororesin and the other contains a resin other than a fluororesin, the thermoplastic resin substrate containing the fluororesin may be disposed on either the indoor side or the sunlight side, preferably the sunlight side.

[0104] The heat ray shielding film of the present disclosure is suitable for use in agricultural applications such as building window materials, roofing materials, ship window materials, aircraft window materials, vehicle window materials, and agricultural greenhouses.

[0105] <Method for producing heat ray shielding film> The method for producing the heat ray-shielding film of the present disclosure is not particularly limited as long as the heat ray-shielding film can be obtained. The surface facing the heat ray shielding layer in the thermoplastic resin substrate can be surface treated in advance. Surface treatment is not particularly limited, and examples thereof include corona discharge treatment, plasma discharge treatment, ozone treatment, flame treatment, chemical conversion treatment, and primer treatment. As surface treatment, corona discharge treatment is more preferably used.

[0106] When the coating liquid for forming the heat ray shielding layer contains an ultraviolet curable resin as a binder resin precursor, it is preferred that after applying the coating liquid to the thermoplastic resin substrate, the obtained coating film is dried to remove the solvent, and then irradiated with ultraviolet light to cure the ultraviolet curable resin to form the heat ray shielding layer. The timing for curing the ultraviolet curable resin can be exemplified by the following (1) and (2).

[0107] (1) After the ultraviolet curable resin is cured to form a heat ray shielding layer, another thermoplastic resin substrate is placed on the heat ray shielding layer. (2) Before curing the ultraviolet curable resin, another thermoplastic resin substrate is placed on the coating film formed with the heat ray shielding layer coating liquid to form a laminate, and then ultraviolet rays are irradiated from the outside of the laminate to cure the ultraviolet curable resin.

[0108] In the case of the manufacturing method of (1), it is preferred to provide an adhesive layer or a pressure-sensitive adhesive layer between the heat ray shielding layer and the other thermoplastic resin substrate. In this case, an adhesive layer or a pressure-sensitive adhesive layer may be formed by applying an adhesive layer or a pressure-sensitive adhesive to the other thermoplastic resin substrate, and the heat ray shielding layer on the thermoplastic resin substrate and the adhesive layer or the pressure-sensitive adhesive layer on the other thermoplastic resin substrate may be overlapped so as to contact each other.

[0109] In the case of the manufacturing method (2), an adhesive layer or a pressure-sensitive adhesive layer may or may not be provided between the heat ray shielding layer and the other thermoplastic resin substrate. In view of operability, manufacturing cost, etc., in the case of the manufacturing method (2), it is preferred not to provide an adhesive layer or a pressure-sensitive adhesive layer. In the production method (2), when a thermoplastic resin substrate containing a UV absorber and a thermoplastic resin substrate not containing a UV absorber are used, it is preferred to cure the UV curable resin by irradiating the substrate with UV rays from the side of the thermoplastic resin substrate not containing a UV absorber.

[0110] Agricultural greenhouses The agricultural greenhouse disclosed herein includes the heat-ray-shielding film disclosed herein. Examples of agricultural greenhouses include, for example, a film-like heat-ray-shielding film, such as a pipe greenhouse in which the heat-ray-shielding film is spread to cover the entire surface or top of an agricultural greenhouse frame. Furthermore, examples of agricultural greenhouses include a sheet-like or plate-like heat-ray-shielding film, such as an agricultural greenhouse in which the heat-ray-shielding film is surrounded by a frame or the like and attached to the top or side of the agricultural greenhouse.

[0111] Because agricultural greenhouses equipped with the heat-ray-shielding film of the present disclosure maintain their heat-ray reflectivity over a long period of time, they can particularly suppress room temperature increases during long summer days, reducing air conditioning loads. When cultivating plants in agricultural greenhouses, even during summer daytime, plant leaf temperatures are unlikely to reach high temperatures, thus preventing growth stunting. This film is suitable for forcing the growth of, for example, Solanaceae fruits and vegetables such as eggplant, tomato, green pepper, and capsicum; Cucurbitaceae fruits and vegetables such as cucumber, pumpkin, loofah, zucchini, cantaloupe, and watermelon; and Malvaceae fruits and vegetables such as okra. Therefore, it is particularly suitable for use in agricultural greenhouses for plant cultivation. Example

[0112] The present invention will be described in detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

[0113] [Example 1] One surface of a 100 μm thick ETFE film (ETFE composition: TFE unit / E unit / PFBE unit = 54 / 46 / 1.3 (molar ratio), melting point 260°C, MFR 11.5 g / 10 min) was corona-discharge treated. An ITO dispersion was then applied to the corona-discharge-treated surface by micro-gravure coating at a line speed of 5 m / min and dried at 80°C to obtain a dried film serving as a heat-ray shielding layer precursor. The ITO dispersion used was PI-3 (trade name: ITO:acrylic resin mass ratio = 74:46) manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.

[0114] The dried film was irradiated with a mercury lamp at 160W to form a heat ray shielding layer with an average thickness of 0.8 μm. After that, the surface of the obtained heat ray shielding layer was subjected to corona discharge treatment, and then a primer treatment liquid was applied to form a primer layer with a thickness of 0.03 μm. As the primer treatment liquid, a solution containing 1 part by mass of aminosilane (product name "KBM903", manufactured by Shin-Etsu Chemical Co., Ltd.), 0.05 part by mass of a leveling agent (product name "Sanfenol (サンフェノール) 420", manufactured by Shin-Etsu Chemical Co., Ltd.), and 98.95 parts by mass of industrial ethanol (product name "SOLMIX AP-1", manufactured by Nippon Alcohol Trading Co., Ltd.) was used. The drip agent 1 was gravure coated on the above-mentioned primer layer so that the coating amount reached 0.45 g / m 2 The mixture was dried at 80° C. to form a dripping layer having a thickness of 0.45 μm. As the dripping agent 1, the following liquid 1 and liquid 2 were mixed at a mass ratio of 27.3:72.7.

[0115] Solution 1: To 16.1 parts by mass of ion-exchanged water was added 1.5 parts by mass of 1N nitric acid. While stirring, 9.7 parts by mass of silica sol (product name "SNOWTEX (registered trademark) S", manufactured by Nissan Chemical Co., Ltd., pH 10, solids concentration: 30% by mass) was added. Stirring was continued for 30 minutes, and the mixture was allowed to stand at room temperature (25°C) for 1 day to complete the preparation. Liquid 2: To 2.7 parts by mass of ion-exchanged water was added 2 parts by mass of 1N nitric acid. With stirring, 50 parts by mass of industrial ethanol (product name "SOLMIX AP-1", manufactured by Nippon Alcohol Trading Co., Ltd.), 17.8 parts by mass of boehmite (product name "KX-1485", manufactured by KI Chemicals, pH 4.0, solid content concentration: 20% by mass), and 0.2 parts by mass of aminosilane (product name "KBM903", manufactured by Shin-Etsu Chemical Co., Ltd.) were added. Stirring was continued for 30 minutes, and the mixture was allowed to stand at room temperature (25°C) for about one day to complete the preparation.

[0116] The test bodies having the layer structure of ETFE layer (thickness 100 μm) / heat ray shielding layer / drip layer were obtained. The following evaluations were performed on the obtained test bodies. The results are shown in Table 1.

[0117] (Visible light transmittance (%), solar light transmittance (%), haze) The visible light transmittance (%), solar light transmittance (%), and haze of the newly produced test piece were measured using a Shimadzu UV-PC3600 tester in accordance with DIN EN 410 1998. Furthermore, from these values, the value (visible light transmittance - solar light transmittance) / visible light transmittance × 100 was calculated.

[0118] The obtained test pieces were cut into 5 cm x 3 cm sizes to prepare evaluation samples. These evaluation samples were exposed to an open carbon arc lamp for 5000 hours using an accelerated weathering tester (product name: "Daylight Weathering Tester S80" manufactured by Suga Test Instruments Co., Ltd.) in accordance with JIS K7350-4:2008. Ultraviolet light was irradiated onto the test pieces from the ETFE layer side. Regarding the evaluation samples after exposure, visible light transmittance (after exposure) (%), solar light transmittance (after exposure) (%), and haze (after exposure) were measured in the same manner as described above.

[0119] Regarding the visible light transmittance, when the ratio of the value after exposure to the initial value was 0.94 or more, it was evaluated as A, and when it was less than 0.94, it was evaluated as B. Regarding the solar transmittance, the evaluation was A when the ratio of the value after exposure to the initial value was 1.05 or less and the solar transmittance was 80% or less, and the evaluation was B when the ratio of the value after exposure to the initial value was greater than 1.05 or the solar transmittance was greater than 80%. Regarding the haze, when the ratio of the value after exposure to the initial value was 1.2 or less, it was rated A, and when it was greater than 1.2, it was rated B.

[0120] (Appearance, friction) The appearance of the test piece after 5000 hours of exposure was visually inspected. Evaluation A was given when there were no cracks, and evaluation B was given when there were cracks. The friction properties of the test specimens after 5000 hours of exposure were visually checked. Evaluation A was given when there was no white turbidity, and evaluation B was given when there was a white turbidity.

[0121] [Example 2] A 100 μm thick ETFE film (hereinafter referred to as "Film 1") and a 50 μm thick ETFE film (hereinafter referred to as "Film 2") were prepared (both ETFEs had a composition of TFE units / E units / PFBE units = 54 / 46 / 1.3 (molar ratio), a melting point of 260°C, and an MFR of 11.5 g / 10 min). Films 1 and 2 were each subjected to a corona discharge surface treatment on one surface to achieve a surface wettability index of 40 mN / m. The surface wettability index disclosed herein is a value measured using a wettability index tester manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. in accordance with JIS K6768:1999.

[0122] On the surface of the film 2 subjected to the surface treatment, the adhesive composition was applied using an applicator to a coating thickness of 25 μm after drying, and dried at 70° C. for 5 minutes to form an adhesive layer. The adhesive composition used contained 100 parts by mass of SK-2094 (manufactured by Soken Chemical Industry Co., Ltd., solid content 25% by mass), 1 part by mass of a crosslinking agent M-5A (manufactured by Soken Chemical Industry Co., Ltd., solid content 100% by mass), 5 parts by mass of a UV absorber (manufactured by BASF Japan, product name "TINUVIN 479"), and 1.5 parts by mass of a light stabilizer (manufactured by BASF Japan, product name "Hals 123"). The surface treated surface of film 1 was stacked on the obtained adhesive layer and adhered using a hand roller to prevent air bubbles from entering. Thus, a test piece having a layer structure of ETFE layer (thickness 100 μm) / adhesive layer / ETFE layer (thickness 50 μm) was obtained. The test body of Example 2 was evaluated in the same manner as the test body of Example 1. The test body was irradiated with ultraviolet rays from the ETFE layer having a thickness of 100 μm. The results are shown in Table 1.

[0123] [Example 3] The method was the same as in Example 1, except that a 50 μm thick ETFE film was used and no drip agent 1 was applied, resulting in an intermediate product 1 having a layered structure of ETFE layer / heat ray shielding layer (surface treated). Separately, an adhesive layer was formed on film 2 using the same method as in Example 2, resulting in an intermediate product 2 having a layered structure of ETFE layer / adhesive layer. Then, the intermediate body 1 and the adhesive layer of the intermediate body 2 were laminated so as to contact each other. Thus, a test body having a layer structure of ETFE layer (50 μm thick) / adhesive layer / heat ray shielding layer / ETFE layer (50 μm thick) was obtained. The test specimens of Example 3 were evaluated in the same manner as the test specimens of Example 1. The test specimens were irradiated with ultraviolet light from the side of the ETFE layer in contact with the adhesive layer. The results are shown in Table 1.

[0124] [Example 4] In Example 3, except that the ETFE film with a thickness of 50 μm used in the preparation of intermediate 1 is changed to an ETFE film with a thickness of 100 μm, a test body with a layer structure of ETFE layer (thickness 50 μm) / adhesion layer / heat ray shielding layer / ETFE layer (thickness 100 μm) is obtained by the same method as in Example 3. The test body of Example 4 was evaluated in the same manner as the test body of Example 1. The test body was irradiated with ultraviolet rays from the side of the ETFE layer (thickness 100 μm) in contact with the heat ray shielding layer. The results are shown in Table 1.

[0125] [Example 5] A test body having a layer structure of ETFE layer (thickness 100 μm) / heat ray shielding layer / adhesive layer / ETFE layer (thickness 50 μm) was prepared in the same manner as in Example 4. The outer surface of the ETFE layer (thickness 50 μm) side of the test body was then subjected to a corona discharge treatment and then to a primer coating. The dripping agent 1 was then gravure-coated thereon in an amount of 0.45 g / m 2 , and dried at 80°C. The primer treatment liquid and dripping agent used were the same as those of Example 1. Thus, a test body having a layer structure of ETFE layer (thickness 100 μm) / heat ray shielding layer / adhesive layer / ETFE layer (thickness 50 μm) / drip layer was obtained. The test body of Example 5 was evaluated in the same manner as the test body of Example 1. The test body was irradiated with ultraviolet rays from the ETFE layer side having a thickness of 100 μm. The results are shown in Table 1.

[0126] [Example 6] An ETFE film having a thickness of 100 μm (hereinafter referred to as "film 1") and an ETFE film having a thickness of 25 μm (hereinafter referred to as "film 3") were prepared (both ETFE films had a composition of TFE unit / E unit / PFBE unit = 54 / 46 / 1.3 (molar ratio), a melting point of 260°C, and an MFR of 11.5 g / 10 min). Film 1 was surface treated with corona discharge on one surface, while Film 3 was surface treated with corona discharge on both surfaces. The surface treated surface of film 1 was coated with the same ITO dispersion as in Example 1 by micro-gravure coating at a line speed of 5 m / min. After drying at 80°C, the film was immediately overlapped with the coated surface of film 3 and bonded by roller pressing. Then, the laminate was irradiated with a mercury lamp at 160W to cure the precursor layer of the heat ray shielding layer to form a heat ray shielding layer. The average thickness of the heat ray shielding layer was 0.8 μm. Thus, a laminate having a layer structure of ETFE layer (thickness 100 μm) / heat ray shielding layer / ETFE layer (thickness 25 μm) was obtained.

[0127] Then, the outer surface of the laminate on the film 3 side was subjected to the same primer treatment as in Example 1, and the same drip agent 1 as in Example 1 was gravure coated thereon to a coating amount of 0.45 g / m 2 and dried at 80° C. Thus, a test body having a layer structure of ETFE layer (thickness 100 μm) / heat ray shielding layer / ETFE layer (thickness 25 μm) / dripping layer was obtained. The test body of Example 6 was evaluated in the same manner as the test body of Example 1. The test body was irradiated with ultraviolet rays from the ETFE layer having a thickness of 100 μm. The results are shown in Table 1.

[0128] [Example 7] The method was the same as in Example 6, except that the 100 μm thick ETFE film was replaced with a 100 μm thick ETFE film mixed with a UV absorber. The resulting test piece had a layered structure consisting of ETFE layer (100 μm thick, containing a UV absorber) / heat ray shielding layer / ETFE layer (25 μm thick) / drip layer. Amorphous silicon oxide-cerium oxide-silicon oxide composite particles (Seriguard S-3018-02, manufactured by Japan Inorganic Chemical Co., Ltd., with an average particle size of 2.2 μm) were used as the UV absorber. The UV absorber content in the ETFE film was 0.63% by mass. The test body of Example 7 was evaluated in the same manner as that of the test body of Example 1. The results are shown in Table 1.

[0129] [Example 8] The method is the same as in Example 1, but without applying the dripping agent 1, to prepare an intermediate 1 having a layer structure of ETFE layer / heat ray shielding layer (with surface treatment). On the other hand, an adhesive layer is formed on the film 2 to prepare an intermediate 2 having a layer structure of ETFE layer / adhesive layer. Then, the heat ray shielding layer of intermediate 1 and the adhesive layer of intermediate 2 were stacked so that they were in contact with each other, pressed together using laminating rollers maintained at a nip temperature of 70°C, and cured at 40°C for 48 hours. Thus, a test body having a layered structure of ETFE layer (thickness 100 μm) / heat ray shielding layer / adhesive layer (thickness 10 μm) / ETFE layer (thickness 25 μm) was obtained. For the adhesive layer, 100 parts by mass (solid content) of the main polyurethane resin HD-1013 (trade name "HD-1013", solid content 60% by mass, manufactured by ROCKPAINT Co., Ltd.), 18.8 parts by mass (solid content) of the curing agent H-62 (isocyanate content: 10% by mass, solid content 75% by mass, manufactured by ROCKPAINT Co., Ltd.), 7 parts by mass of the ultraviolet absorber TINUVIN479 (hydroxyphenyl triazine ultraviolet absorber, manufactured by BASF Japan Co., Ltd.), and 1.5 parts by mass of the light stabilizer HALS123 (hindered amine light stabilizer, manufactured by BASF Japan Co., Ltd.) are mixed to prepare an adhesive composition. HD-1013 is a polyurethane resin obtained by reacting a polycarbonate diol (a1) made from 3-methyl-1,5-pentanediol as a raw material, 1,6-pentanediol as a chain extender (a2), and isophorone diisocyanate (IPDI) as an organic diisocyanate (a3). The main components of H-62 are the urea ester of IPDI and hexamethylene diisocyanate (HDI).

[0130] [Example 9] A test piece having a layer structure of ETFE layer (thickness 100 μm) / heat ray shielding layer / adhesive layer / ETFE layer (thickness 50 μm) / drip layer was obtained in the same manner as in Example 5, except that the primer treatment was not performed and dripping agent 2 was used instead of dripping agent 1 to form the dripping layer. Dripping agent 2 was prepared as follows. Dripping Agent 2: 4.05 parts by mass of 1N nitric acid were added to 28.35 parts by mass of ion-exchanged water. While stirring, 10.7 parts by mass of silica sol (product name "SNOWTEX (registered trademark) S", manufactured by Nissan Chemical Co., Ltd., pH 10, solids concentration: 30% by mass) was added, and stirring was continued for 60 minutes. Subsequently, 48.1 parts by mass of boehmite (product name "KX-1485", manufactured by KI Chemicals Co., Ltd., pH 4.0, solids concentration: 20% by mass) and 0.2 parts by mass of aminosilane (product name "KBM903", manufactured by Shin-Etsu Chemical Co., Ltd.) were added, and stirring was continued for 60 minutes. Furthermore, 8.6 parts by mass of a 14% aqueous solution of modified polyvinyl alcohol (product name "JMR-10M", manufactured by Nippon VAM & POVAL Co., Ltd., degree of polymerization 220, degree of saponification 220 mol%) was added with stirring, and the mixture was stirred for 60 minutes. Thereafter, 100 parts by mass of industrial ethanol (product name "SOLMIX AP-1", manufactured by Nippon Alcohol Trading Co., Ltd.) was added and stirred to complete the preparation.

[0131] [Table 1]

[0132] The heat-ray-shielding films of Examples 3 to 8 maintained suitably suppressed solar transmittance even after 5,000 hours of accelerated weathering resistance testing. Furthermore, due to their excellent visible light transmittance, the heat-ray-shielding films of Examples 3 to 8 were found to be less likely to hinder plant growth when used in agricultural greenhouses. On the other hand, the heat-ray shielding film of Example 1, which had a thermoplastic resin substrate provided on only one side of the heat-ray shielding layer, had an initial solar transmittance of 73.1%, but after 5000 hours of accelerated weathering resistance testing, the solar transmittance increased to 77.4%. Furthermore, the heat-ray shielding film of Example 1 had a significantly increased haze after 5000 hours of accelerated weathering resistance testing, and its appearance and friction properties declined. The heat ray shielding film of Example 2 in which no heat ray shielding layer was provided had a high solar transmittance from the beginning and low heat ray shielding properties. Possibility of industrial application

[0133] The heat ray shielding film of the present disclosure is suitable for use in agricultural applications such as building window materials, vehicle window materials, and agricultural greenhouses.

[0134] The disclosure of Japanese Patent Application No. 2023-014803 is incorporated herein by reference in its entirety. All publications, patent applications, and technical specifications in this disclosure are hereby incorporated by reference into the present disclosure to the same extent as if each publication, patent application, and technical specification was specifically and individually indicated to be incorporated by reference. Explanation of symbols

[0135] 2: Thermoplastic resin substrate A, 4: Heat ray shielding layer, 6: Thermoplastic resin substrate B, 10: Heat ray shielding film.

Claims

1. A heat ray shielding film comprising a thermoplastic resin substrate A, a heat ray shielding layer containing a binder resin and inorganic particles, and a thermoplastic resin substrate B in this order.

2. The heat ray shielding film according to claim 1, wherein The heat ray shielding layer has an average thickness of 1 μm or less.

3. The heat ray shielding film according to claim 1 or 2, wherein The inorganic particles include indium tin oxide.

4. The heat ray shielding film according to claim 1 or 2, wherein At least one of between the heat ray shielding layer and the thermoplastic resin base material A and between the heat ray shielding layer and the thermoplastic resin base material B has an adhesive layer or a bonding layer.

5. The heat ray shielding film according to claim 4, wherein At least one of the adhesive layer or the bonding layer contains an ultraviolet absorber.

6. The heat ray shielding film according to claim 3, wherein At least one of between the heat ray shielding layer and the thermoplastic resin base material A and between the heat ray shielding layer and the thermoplastic resin base material B has an adhesive layer or a bonding layer.

7. The heat ray shielding film according to claim 6, wherein At least one of the adhesive layer or the bonding layer contains an ultraviolet absorber.

8. The heat ray shielding film according to claim 1 or 2, wherein The thermoplastic resin substrate A and the thermoplastic resin substrate B each independently include at least one thermoplastic resin selected from the group consisting of polyolefin resins, polyvinyl chloride resins, polyethylene terephthalate resins, and fluororesins.

9. The heat ray shielding film according to claim 1 or 2, wherein At least one of the thermoplastic resin substrate A and the thermoplastic resin substrate B includes a fluororesin, which is a thermoplastic resin.

10. The heat ray shielding film according to claim 1 or 2, wherein The value of (visible light transmittance - solar light transmittance) / visible light transmittance × 100 is 10% or more, and the ratio of the solar light transmittance after the following exposure treatment to the solar light transmittance before the exposure treatment is 1.05 or less: Exposure treatment: According to JIS K7350-4:2008, exposure was performed under an open carbon arc lamp for 5000 hours.

11. The heat ray shielding film according to claim 1 or 2, wherein At least one of the thermoplastic resin substrate A and the thermoplastic resin substrate B has a drip layer on its outer side. 12 . The heat ray shielding film according to claim 1 , which is for agricultural use. 13 . An agricultural greenhouse comprising the heat ray shielding film according to claim 1 .

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