Infrared shielding structure

Abstract

To provide an infrared shielding structure excellent in high heat ray shielding performance by achieving both heat shielding and heat insulation properties and having bluish designability, and a laminate excellent in heat ray shielding performance and having high adhesion with a layer in post-processing.SOLUTION: The infrared shielding structure includes a base material layer, a resin layer 1 and a resin layer 2 in this order. The resin layer 1 contains infrared absorption particles 1. The resin layer 2 contains infrared absorption particles 2. One of the infrared absorption particle 1 and the infrared absorption particle 2 contains tin element while the other contains tungsten element. The laminate includes the resin layer 1 on at least one surface of the base material layer, and the resin layer 1 contains the infrared absorption particles 1. In the resin layer 1, when detection sensitivity of the infrared absorption particles 1 at positions of 20% of depth from the base material layer toward the opposite is denoted by X20, and detection sensitivity of the infrared absorption particles 1 at positions of 90% of depth is denoted by X90, X20≥2×X90 is satisfied.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an infrared shielding structure and a laminate. [Background technology]

[0002] Transparent materials with excellent heat ray shielding properties have been developed as one of the energy-saving measures for buildings such as buildings and houses, and transportation such as trains and automobiles. Heat ray shielding properties are generally classified into heat shielding properties and heat insulating properties. Heat shielding properties refer to high shielding properties for the near-infrared portion of infrared rays, while heat insulating properties refer to high shielding properties for the mid-infrared to far-infrared portions. Generally, there are few materials that have both excellent shielding and heat insulating properties, and when only one type of material with heat ray shielding properties is contained, only either the heat shielding properties or the heat insulating properties are improved, and the heat ray shielding performance is often insufficient.

[0003] In recent years, as an energy-saving measure, attempts have been made to suppress temperature rises inside rooms and cars, for example by attaching heat-shielding sheets (films) that can block heat rays from sunlight to window glass in buildings and transportation facilities, or by placing an intermediate layer with heat-shielding properties between two pieces of glass.

[0004] Methods of imparting heat ray shielding properties to window glass include providing a heat ray absorbing layer by incorporating inorganic oxides or dyes. For example, proposed methods include forming a heat ray absorbing film containing inorganic oxides or dyes (Patent Document 1), forming a heat ray shielding layer having fine particles with an average particle size of 100 nm or less and a binder (Patent Document 2), and laminating a heat ray absorbing layer having cesium-containing tungsten oxide (Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-132454 [Patent Document 2] International Publication No. 2014 / 061279 [Patent Document 3] Japanese Patent Application Publication No. 2018-116069 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the methods described in the above patent documents all incorporate only one type of material with heat ray shielding function, and only improve either the shielding or the heat insulating properties, resulting in insufficient heat ray shielding performance. Furthermore, in the method described in Patent Document 3, cesium-containing tungsten oxide is uniformly dispersed in the heat ray absorbing layer, but cesium-containing tungsten oxide generally tends to have a bluish tint. Therefore, if the amount of cesium-containing tungsten oxide in the heat ray absorbing layer is increased to improve the heat ray shielding properties, the blue tint of the glass itself will also become stronger, which may impair the design aesthetics when applied to windows. Thus, the conventional methods described in Patent Documents 1 to 3 have difficulty imparting high heat ray shielding performance that combines heat shielding and heat insulating properties while maintaining design aesthetics.

[0007] Furthermore, the method of Patent Document 1 uses a specific dispersant to form a heat-absorbing film in which inorganic oxides or dyes are uniformly dispersed throughout the film, and although the heat-shielding properties are good, there is also the problem that the adhesion is insufficient when further processing the heat-absorbing film with a hard coat or the like. The methods of Patent Documents 2 and 3 also have similar problems because they involve uniformly dispersing fine particles or cesium-containing tungsten oxide. Thus, the conventional methods listed in Patent Documents 1 to 3 have the problem of insufficient adhesion to layers formed by post-processing.

[0008] In order to solve these problems, the present invention aims to provide a laminated structure that has excellent heat ray shielding performance by combining heat shielding and heat insulating properties, and also has a design that suppresses blue tinge, and in providing such a laminated structure, to provide a laminated structure that has excellent heat ray shielding performance and excellent adhesion to layers formed by post-processing. [Means for solving the problem]

[0009] The present inventors have conducted extensive research in light of the above-mentioned problems and have found that the above-mentioned problems can be solved by providing an infrared-shielding structure including resin layers each containing two types of infrared-shielding particles having different shielding properties, thereby completing the present invention. Furthermore, the present inventors have found that by using a laminate including a resin layer in which the infrared-shielding particles are unevenly distributed, a laminate having excellent adhesion between the resin layer and a functional material provided on the resin layer can be obtained, thereby completing the present invention.

[0010] That is, the present invention provides an infrared shielding structure comprising a base layer, a resin layer 1, and a resin layer 2 in this order, the resin layer 1 containing infrared absorbing particles 1, the resin layer 2 containing infrared absorbing particles 2, one of the infrared absorbing particles 1 and the infrared absorbing particles 2 containing elemental tin, and the other containing elemental tungsten; or an infrared shielding structure having a resin layer 1 on at least one surface of a base layer, the resin layer 1 containing infrared absorbing particles 1, and a detection sensitivity of the infrared absorbing particles 1 at a position 20% of the thickness of the resin layer 1 from the base layer side toward the opposite side is X 20 The detection sensitivity of the infrared absorbing particle 1 at the 90% thickness position is X 90 When X 20 ≧2×X 90 The laminate is characterized by satisfying the following:

[0011] Furthermore, from the viewpoint of solving the above-mentioned problems, the infrared shielding structure of the present invention can be configured as follows, and furthermore, the infrared shielding structure of the present invention can be used to form a window. (1) An infrared shielding structure comprising a substrate layer, a resin layer 1, and a resin layer 2 in this order, wherein the resin layer 1 contains infrared absorbing particles 1, the resin layer 2 contains infrared absorbing particles 2, and one of the infrared absorbing particles 1 and the infrared absorbing particles 2 contains elemental tin, and the other contains elemental tungsten. (2) In the resin layer 1, the detection sensitivity of the infrared absorbing particles 1 at a position of 20% of the thickness from the base layer side toward the resin layer 2 side is X20 When the detection sensitivity of the infrared absorption particles 1 at the 90% thickness position is X 90 and X 20 ≥ 2 × X 90 is satisfied, the infrared shielding structure according to (1). (3) The infrared shielding structure according to (1) or (2), wherein the infrared absorption particles 1 contain tin elements and the infrared absorption particles 2 contain tungsten elements. (4) The infrared shielding structure according to any one of (1) to (3), wherein when the thickness of the resin layer 1 is D1 and the thickness of the resin layer 2 is D2, D1 < D2 is satisfied. (5) The infrared shielding structure according to any one of (1) to (4), wherein the resin layer 1 contains an acrylic resin and a polyester resin, and the ratio of the acrylic resin increases and the ratio of the polyester resin decreases from the base material layer side toward the resin layer 2 side. (6) The infrared shielding structure according to any one of (1) to (5), wherein the maximum value of the reflectance at a wavelength of 800 to 1000 nm measured from the base material layer side is 50% or more and 110% or less. (7) The infrared shielding structure according to any one of (1) to (6), wherein an adhesive layer is provided on the surface of the base material layer opposite to the resin layer 1, and the adhesive layer contains a UV absorber. (8) A window comprising glass, the adhesive layer, and the infrared shielding structure according to any one of (1) to (7) in this order, wherein the base material layer is located on the glass side rather than the resin layer 2.

[0012] In addition, the laminate of the present invention can also be in the following aspects, and can also be used as a window. (9) A resin layer 1 is provided on at least one surface of a base material layer, the resin layer 1 contains infrared absorption particles 1, and in the resin layer 1, when the detection sensitivity of the infrared absorption particles 1 at the 20% thickness position from the base material layer side toward the opposite side is X 20 and the detection sensitivity of the infrared absorption particles 1 at the 90% thickness position is X 90 and X 20 ≥ 2 × X 90 is satisfied, the laminate is characterized by this. (10) The laminate according to (9), wherein the resin layer 1 contains an acrylic resin and a polyester resin, and the ratio of the acrylic resin increases and the ratio of the polyester resin decreases from the base layer side to the opposite side. (11) The laminate according to (9) or (10), wherein the infrared absorbing particles 1 contain tin element. (12) The laminate according to any one of (9) to (11), wherein the maximum value of reflectance at a wavelength of 800 to 1000 nm measured from the substrate layer side is 50% or more and 110% or less. (13) The laminate according to any one of (9) to (12), further comprising a resin layer 2 on the surface of the resin layer 1 opposite to the base layer, the resin layer 2 containing infrared absorbing particles 2 different from the infrared absorbing particles 1. (14) The laminate according to (13), wherein the infrared absorbing particles 2 contain elemental tungsten. (15) The laminate according to (13) or (14), wherein the substrate layer has an adhesive layer on the surface opposite to the resin layer 1, and the adhesive layer contains a UV absorber. (16) A window having the laminate according to (15) and provided with glass on the surface of the adhesive layer opposite the substrate layer. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide an infrared shielding structure that has excellent heat ray shielding performance due to its combination of heat shielding and heat insulating properties, and has a design with reduced blue tinge, or a laminate that has excellent heat ray shielding performance and excellent adhesion to a layer formed by post-processing. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic diagram showing an example of an infrared shielding structure of the present invention, and a position at 20% thickness and a position at 90% thickness in a resin layer 1 from a substrate layer side to a resin layer 2 side. [Figure 2] 1 is a schematic diagram showing an example of the laminate of the present invention, and a position at 20% thickness and a position at 90% thickness from the substrate layer side toward the opposite side. DETAILED DESCRIPTION OF THE INVENTION

[0015] The infrared shielding structure of the present invention comprises a substrate layer, a resin layer 1, and a resin layer 2 in this order, the resin layer 1 containing infrared absorbing particles 1, the resin layer 2 containing infrared absorbing particles 2, one of the infrared absorbing particles 1 and the infrared absorbing particles 2 containing elemental tin and the other containing elemental tungsten. Also, the laminate of the present invention has a resin layer 1 on at least one surface of the substrate layer, the resin layer 1 containing infrared absorbing particles 1, and the detection sensitivity of the infrared absorbing particles 1 at a position 20% of the thickness of the resin layer 1 from the substrate layer side toward the opposite side is X 20 The detection sensitivity of the infrared absorbing particle 1 at the 90% thickness position is X 90 When X 20 ≧2×X 90 The infrared shielding structure and laminate of the present invention will be described in detail below, but the present invention should not be construed as being limited to the embodiments including the following examples, and various embodiments that can achieve the object of the invention and do not deviate from the gist of the invention are naturally included in the scope of the present invention.

[0016] The infrared shielding structure of the present invention has a substrate layer, a resin layer 1, and a resin layer 2 in this order, from the viewpoint of combining heat-shielding properties and heat insulation properties and reducing a blue tint. Here, "having a substrate layer, a resin layer 1, and a resin layer 2 in this order" refers to a general embodiment in which the substrate layer, the resin layer 1, and the resin layer 2 are arranged in this order, regardless of the presence or absence of other layers. Furthermore, the laminate of the present invention has a resin layer 1 on at least one surface of the substrate layer. Each layer will be described in detail below.

[0017] The substrate layer in the infrared shielding structure of the present invention is not particularly limited as long as the resin layer 1 can be formed on its surface directly or via another layer, and examples of the components that can be used include glass, thermoplastic resins, thermosetting resins, and photocurable resins. From a manufacturing standpoint, it is preferable for the substrate layer of the infrared shielding structure of the present invention to be primarily composed of a thermoplastic resin. The term "primary component" refers to a component that accounts for more than 50% by mass and not more than 100% by mass of all the components of the target layer. Hereinafter, unless otherwise specified, the term "primary component" can be interpreted in the same way regardless of the target. Furthermore, "at least one side" refers to both one side and both sides.

[0018] The thermoplastic resin used in the base layer is not particularly limited, and examples thereof include linear polyolefin resins such as polyethylene, polypropylene, poly(4-methylpentene-1), and polyacetal; alicyclic polyolefin resins which are ring-opening metathesis polymers of norbornenes, addition polymers, and addition copolymers with other olefins; biodegradable polymers such as polylactic acid and polybutyl succinate; polyamide resins such as nylon 6, nylon 11, nylon 12, and nylon 66; aramid, polymethyl methacrylate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, ethylene vinyl acetate copolymer, and polyacetal. Examples of resins that can be used include polyester resins such as tar, polyglycolic acid, polystyrene, styrene copolymerized polymethyl methacrylate, polycarbonate, polypropylene terephthalate, polyethylene terephthalate, polybutylene terephthalate, and polyethylene-2,6-naphthalate, as well as polyethersulfone, polyetheretherketone, modified polyphenylene ether, polyphenylene sulfide, polyetherimide, polyimide, polyarylate, tetrafluoroethylene resin, trifluoroethylene resin, trifluorochloroethylene resin, tetrafluoroethylene-hexafluoropropylene copolymer, and polyvinylidene fluoride. Among these, polyester is particularly preferred because of its excellent mechanical properties, electrical properties, dimensional stability, transparency, and chemical resistance. These resins may be copolymers, and may be used alone or as a mixture of two or more resins.

[0019] In the present invention, an infrared-shielding structure refers to a structure in which three or more types of layers are laminated and the overall infrared transmittance is 80% or less. Furthermore, a resin layer refers to a layer containing 10% to 100% by mass of resin components, where 100% by mass is the total mass of all components constituting the layer. By providing such a resin layer on the surface of a substrate layer, it is possible to impart functions such as heat-shielding properties, heat insulation properties, easy adhesion between the substrate and the resin layer or between two resin layers with different functions, scratch resistance, and design properties. Furthermore, a laminate of the present invention refers to a structure consisting only of a substrate layer and a resin layer 1.

[0020] Polyester is a general term for polymers in which ester bonds are the main bonding chains in the main chain. Polyesters containing at least one component selected from ethylene terephthalate, propylene terephthalate, ethylene-2,6-naphthalate, butylene terephthalate, propylene-2,6-naphthalate, ethylene-α,β-bis(2-chlorophenoxy)ethane-4,4'-dicarboxylate, etc. as the main component are preferably used. Herein, the term "main component" refers to a component (structural unit) that accounts for more than 50 mol% but not more than 100 mol%, assuming that all components (structural units) constituting the polymer are 100 mol%. Hereinafter, polyester may be referred to as polyester resin, and a film containing polyester as the main component may be referred to as polyester film.

[0021] In the present invention, it is preferable to use a film as the base layer and form a resin layer 1 on the surface of the film for the base layer. The type of film for the base layer is not particularly limited, but it is preferable to use a polyester film, and more preferable to use a polyethylene terephthalate film. Furthermore, if heat, shrinkage stress, or the like is applied to the infrared shielding structure during the manufacturing process, processing process, or use, it is preferable to use a polyethylene naphthalate film, which has excellent heat resistance and rigidity. Here, polyethylene terephthalate refers to polyester containing ethylene terephthalate as the main constituent, and polyethylene terephthalate film refers to a film containing more than 50% by mass but not more than 100% by mass of polyethylene terephthalate, assuming that all components constituting the film are 100% by mass. Polyethylene naphthalate and polyethylene naphthalate film can also be interpreted in the same way.

[0022] If a film contains multiple components equivalent to polyethylene terephthalate, the film is considered to be a polyethylene terephthalate film if the total amount of these components is more than 50% by mass but not more than 100% by mass. In this respect, polyethylene naphthalate film can also be interpreted in the same way.

[0023] Furthermore, the polyester film for the base layer is preferably a biaxially oriented polyester film. A biaxially oriented polyester film is a polyester film that exhibits a biaxially oriented pattern in wide-angle X-ray diffraction. A biaxially oriented polyester film can generally be obtained by stretching an unstretched polyester sheet or film in two perpendicular directions (e.g., the longitudinal direction and the width direction) and completing the crystal orientation by heat treatment. The stretching ratio is preferably 2 to 15 times in both directions. When the polyester film for the base layer is a biaxially oriented polyester film, the thermal stability, particularly the dimensional stability and mechanical strength, of the infrared shielding structure is improved, and flatness is also improved. The longitudinal direction refers to the direction in which the film runs during the manufacturing process, and in the case of a film roll, this corresponds to the winding direction. The width direction refers to the direction perpendicular to the longitudinal direction within the film plane.

[0024] Furthermore, various additives such as antioxidants, heat stabilizers, weather stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or inorganic fine particles, fillers, antistatic agents, nucleating agents, etc. may be added to the polyester film for the base layer to the extent that they do not deteriorate the properties of the film. These components may also be used in combination.

[0025] The thickness of the polyester film for the base layer is not particularly limited and is appropriately selected depending on the application and type, but is usually preferably 10 to 500 μm, more preferably 20 to 250 μm, and most preferably 30 to 150 μm in terms of mechanical strength, handleability, etc. The polyester film for the base layer may be a composite film obtained by coextrusion, or may be a film obtained by laminating obtained films by various methods.

[0026] From the viewpoint of providing the infrared shielding structure of the present invention with both heat-shielding properties and heat insulation properties and reducing blue tinge, it is important that the resin layer 1 contains infrared absorbing particles 1, the resin layer 2 contains infrared absorbing particles 2, one of the infrared absorbing particles 1 and the infrared absorbing particles 2 contains elemental tin and the other contains elemental tungsten.

[0027] Here, we briefly explain heat-shielding and heat-insulating properties. High heat-shielding properties refer to high shielding performance in the near-infrared region of infrared rays, while high heat-insulating properties refer to high shielding performance in the mid-infrared to far-infrared region. Heat-shielding properties are measured using the total energy transmittance (Tts) measured in accordance with ISO 13837:2008, "Road vehicles - Safety glazing materials - Measurement method for solar transmittance." Tts is an index that emphasizes the ability to shield solar energy, particularly in the wavelength range of 700 to 1500 nm. On the other hand, heat-insulating properties are measured using the heat transmission coefficient measured in accordance with JIS-R3107:2019. Heat transmission coefficient is an index that emphasizes the ability to shield energy in the wavelength range exceeding 1500 nm. Therefore, for an infrared-shielding structure to block solar energy over a wide wavelength range and have high heat-shielding performance, it is important that it possess both heat-shielding and heat-insulating properties. Details of the methods for measuring Tts and heat transmission coefficient will be described later.

[0028] In the present invention, infrared-absorbing particles refer to particles that have light absorbing properties mainly in the near-infrared to far-infrared wavelength range of 700 nm or more. Examples include lanthanum-based particles, antimony-based particles, indium-based particles, tin-based particles, and tungsten-based particles. These particles have low light absorption in the visible light range, making them suitable for use in infrared-shielding structures and laminates that require colorless transparency. Furthermore, lanthanum-based particles and tungsten particles generally have high light absorption properties, particularly in the wavelength range of 700 to 1500 nm, while antimony-based particles, indium-based particles, and tin-based particles have high light absorption properties, particularly in the wavelength range of wavelengths exceeding 1500 nm. That is, lanthanum-based particles and tungsten particles have high heat-shielding properties, while antimony-based particles, indium-based particles, and tin-based particles have high heat-insulating properties.

[0029] In general, infrared-absorbing particles are preferably doped with a third component to achieve both chemical stability and infrared absorption. For example, dopants such as Sb, V, Nb, and Ta are preferred for tin-based particles; Zn, Al, Sn, Sb, Ga, and Ge are preferred for indium-based particles; and Cs, Rb, K, Tl, In, Ca, Sr, Fe, Sn, and Al are preferred for tungsten-based particles. Furthermore, lanthanum hexaboride is preferred for lanthanum-based particles. The dopant content is not particularly limited, but is preferably 1 to 20 mass% and more preferably 5 to 15 mass% based on 100 mass% of the total amount of the doped infrared-absorbing particles. The same applies to the tin content in tin-containing indium oxide (ITO). A dopant content within the above range is preferred because it not only improves chemical stability and infrared absorption performance, but also maintains transparency when used in an infrared-shielding structure or laminate.

[0030] In the infrared shielding structure and laminate of the present invention, it is preferable to use tungsten-based particles or lanthanum-based particles doped with the third component described above to improve heat shielding properties. However, of the two, tungsten-based particles have better absorption performance in the wavelength range of 700 to 1500 nm. Therefore, it is important that one of the infrared absorbing particles contained in the infrared shielding structure of the present invention contains elemental tungsten. Furthermore, it is preferable to use antimony-based particles, indium-based particles, or tin-based particles to improve heat insulation properties. However, it is more effective to use these as tin-containing indium oxide (ITO) or antimony-containing tin oxide (ATO), and tin-containing indium oxide (ITO) is even more effective. Therefore, it is important that the other infrared absorbing particle contained in the infrared shielding structure of the present invention contains elemental tin.

[0031] The resin layer 1 and the resin layer 2 of the infrared shielding structure of the present invention each contain different infrared-absorbing particles. To achieve both heat-shielding and heat-insulating properties for the infrared shielding structure, it is possible to use the two types of infrared-absorbing particles described above in combination in one of the layers. However, when incorporating infrared-absorbing particles into the resin layer, the infrared-absorbing particles may be dispersed in a solvent using a modified resin, as described below. However, different modified resins are required for each layer, and mixing two types of the same modified resin can cause the dispersion to become unstable and lead to aggregation. Therefore, it is difficult to incorporate the desired amount of infrared-absorbing particles into one resin layer. If the amount of infrared-absorbing particles in the resin layer is insufficient, the heat-shielding performance of the infrared shielding structure will be insufficient. Conversely, if more infrared-absorbing particles than necessary must be added due to aggregation, the infrared shielding structure will have a strong blue tinge, resulting in poor transparency and a loss of design appeal.

[0032] Therefore, as a result of intensive research, the inventors have invented an infrared shielding structure in which the resin layer 1 contains infrared absorbing particles 1, the resin layer 2 contains infrared absorbing particles 2, one of the infrared absorbing particles 1 and the infrared absorbing particles 2 contains elemental tin and the other contains elemental tungsten, thereby providing both heat-shielding properties and heat insulation, thereby providing excellent heat ray shielding performance, and also having a design with reduced blue tint.

[0033] Furthermore, in the infrared shielding structure of the present invention, it is more preferable that the infrared absorbing particles 1 contain elemental tin and the infrared absorbing particles 2 contain elemental tungsten. In general, infrared particles containing elemental tin are often more thermally, optically, and chemically stable than infrared particles containing elemental tungsten, and an aqueous dispersion thereof can be easily prepared. Therefore, for example, when the base layer is a thermoplastic resin film, the resin layer 1 can be formed by a coating method using an aqueous dispersion simultaneously with film formation, and the infrared shielding structure of the present invention can be obtained more inexpensively.

[0034] The resin layer 1 in the infrared shielding structure and laminate of the present invention is not particularly limited in terms of its constituent components as long as it contains infrared absorbing particles 1. However, from the viewpoint of ease of forming a phase-separated structure described later, it is preferable that the resin layer 1 be a layer using a resin composition containing a binder resin.

[0035] In the infrared shielding structure and laminate of the present invention, the detection sensitivity of the infrared absorbing particles 1 at a position of 20% of the thickness from the base layer side to the resin layer 2 side in the resin layer 1 is X 20 , the detection sensitivity of infrared absorbing particle 1 at the 90% thickness position is X 90 When X 20 ≧2×X 90 It is preferable that the following condition is satisfied. Hereinafter, the positions at 20% thickness and 90% thickness will be described with reference to the drawings from the base layer side toward the resin layer 2 side.

[0036] Fig. 1 is a schematic diagram showing an example of an infrared shielding structure of the present invention, and the positions at 20% and 90% thickness from the substrate layer side toward the resin layer 2 side. In Fig. 1, reference numeral 1 denotes the resin layer 2, reference numeral 2 denotes the resin layer 1, reference numeral 3 denotes the substrate layer, and reference numerals 4 and 5 denote the positions at 20% and 90% thickness (reference numeral 4 and reference numeral 5) in the resin layer 1 from the substrate layer side toward the resin layer 2 side, respectively. 20 ≧2×X 90 By satisfying the above, it is possible to easily improve the adhesion between resin layer 1 and resin layer 2 in addition to the heat-shielding and heat-insulating properties. FIG. 2 is a schematic diagram showing an example of the laminate of the present invention and each position in resin layer 1. In FIG. 2, the reference numerals 6 to 9 respectively represent "resin layer 1," "substrate layer," "position at 20% of the thickness in resin layer 1 from the substrate layer side toward the opposite side," and "position at 90% of the thickness in resin layer 1 from the substrate layer side toward the opposite side."

[0037] X 20 , X 90can be measured by X-ray photoelectron spectroscopy (XPS), and the specific measurement method and conditions will be described later. Furthermore, "a position at 20% of the thickness from the substrate layer side toward the resin layer 2 side of resin layer 1" refers to a position at 20% of the thickness when the interface of resin layer 1 with the substrate layer is 0% and the surface of resin layer 1 on the resin layer 2 side is 100%. "A position at 90% of the thickness" can be interpreted in the same way.

[0038] In the infrared shielding structure and laminate of the present invention, the resin layer 1 is X 20 ≧2×X 90 Satisfying this condition means that the infrared absorbing particles 1 are unevenly distributed toward the base layer side in the thickness direction of the resin layer 1. The resin layer 1 preferably contains a binder resin that forms the resin layer in addition to the infrared absorbing particles 1. By unevenly distributing the infrared absorbing particles 1 toward the base layer side of the resin layer 1, the binder resin can be concentrated on the side of the resin layer 1 opposite the base layer, and adhesiveness with other resin layers can be exhibited in post-processing. Furthermore, by not dispersing the infrared absorbing particles 1 throughout the resin layer 1, the heat-shielding or heat-insulating performance of the infrared absorbing particles 1 can be more efficiently exhibited.

[0039] The resin layer 1 of the present invention is X 20 ≧2×X 90 There is no particular limitation on the means for satisfying this condition, and for example, it is possible to use a method of appropriately selecting a modifying resin for the infrared absorbing particles 1 and a binder resin for forming the resin layer 1. More specifically, this method is a method of selecting, as the modifying resin for the infrared absorbing particles 1, a resin that is likely to separate to the base layer side during phase separation, which will be described later, from among the binder resins for forming the resin layer 1.

[0040] The infrared absorbing particles 1 are preferably modified with a resin on a part or all of their surfaces. Here, modification refers to a resin component being bonded by a covalent bond or the like, or being physically adsorbed by a non-covalent bond. By modifying a part or all of the surface of the infrared absorbing particles 1 with a resin, it is possible to disperse the infrared absorbing particles 1 in a solvent, to suppress aggregation of the infrared absorbing particles during the drying process when forming a resin layer 1 by applying a coating material, and to form a phase separation structure described later to prevent X 20≧2×X 90 Furthermore, the type of resin used for modification is not particularly limited, but it is more preferable that the resin is the same as the binder resin described below, from the viewpoint of forming a phase-separated structure.

[0041] The method for modifying the infrared absorbing particles is not particularly limited, but examples thereof include a method of surface treating the infrared absorbing particles with a resin. Specifically, the method can be appropriately selected from the following methods (i) to (iv). In the present invention, the surface treatment refers to a treatment in which a resin is adsorbed or attached to all or part of the surface of the infrared absorbing particles. (i) A method in which a mixture of infrared absorbing particles and a resin is mixed in advance, added to a solvent, and then dispersed. (ii) A method of adding infrared absorbing particles and a resin in that order to a solvent and dispersing them. (iii) A method in which infrared absorbing particles and a resin are dispersed in a solvent in advance, and the resulting dispersion is mixed. (iv) A method in which infrared absorbing particles are dispersed in a solvent, and then a resin is added to the resulting dispersion.

[0042] Devices that can be used to disperse the components include dissolvers, high-speed mixers, homomixers, meaders, ball mills, roll mills, sand mills, paint shakers, SC mills, annular mills, and pin mills. To disperse the components, it is preferable to use any of the above devices, rotate the rotating shaft at a peripheral speed of 5 to 15 m / s, and set the rotation time to 5 to 10 hours. To improve dispersibility, it is more preferable to use dispersion beads such as glass beads. The particle size of the dispersion beads is preferably 0.05 to 0.5 mm, more preferably 0.08 to 0.5 mm, and even more preferably 0.08 to 0.2 mm. Methods for mixing and stirring can be appropriately selected from shaking the container by hand, using a magnetic stirrer or stirring blade, ultrasonic irradiation, vibration dispersion, etc.

[0043] In the present invention, the infrared ray absorbing particles 1 contained in the resin layer 1 preferably account for 10 to 90 mass % in terms of metal components when the entire resin layer 1 is taken as 100 mass %. By setting the amount of the infrared ray absorbing particles 1 contained in the resin layer 1 within the above range, the heat ray shielding property is improved.

[0044] The resin layer 1 in the infrared shielding structure and laminate of the present invention preferably contains a binder resin to form the layer, and may also contain a reactive compound that reacts with the binder resin to form a stronger resin layer. Examples of binder resins include polyester resins, acrylic resins, urethane resins, and epoxy resins, which can be used alone or in combination. The reactive compound can also be any compound, such as an oxazoline compound, a carbodiimide compound, a melamine compound, an isocyanate compound, or a combination thereof. Note that even if the reactive compound forms a separate chemical structure derived from the compound with the binder resin component or the like through a crosslinking reaction or the like, and the reactive compound is not present in the resin layer 1 as a single component, the resin layer 1 can still be considered to contain the reactive compound.

[0045] The polyester resin, acrylic resin, urethane resin, and epoxy resin suitable as the binder resin of the resin layer 1 and the modifying resin of the infrared absorbing particles 1 in the infrared shielding structure of the present invention will be described in more detail. The modifying resin and the binder resin may be the same or different. They may be one type or a mixture of multiple types.

[0046] The dicarboxylic acid component used as the raw material for the polyester resin can be an aromatic, aliphatic, or alicyclic dicarboxylic acid. Examples of aromatic dicarboxylic acids that can be used include terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 2,5-dimethylterephthalic acid, 1,4-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2-bisphenoxyethane-p-p'-dicarboxylic acid, and phenylindanedicarboxylic acid. Examples of aliphatic and alicyclic dicarboxylic acids that can be used include succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, dimer acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid, as well as ester-forming derivatives thereof, which can be used alone or in combination.

[0047] Diol components used as raw materials for polyester resins include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, neopentyl glycol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 3-methyl-1,5-pentanediol, and 2,2,4-trimethyl-1,6-hexanone. Sandiol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 4,4'-thiodiphenol, bisphenol A, 4,4'-methylenediphenol, 4,4'-(2-norbornylidene)diphenol, 4,4'-dihydroxybiphenol, o-, m-, and p-dihydroxybenzene, 4,4'-isopropylidenephenol, 4,4'-isopropylidenebindiol, cyclopentane-1,2-diol, cyclohexane-1,2'-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, and the like can be used alone or in combination.

[0048] As the polyester resin, it is also possible to use modified polyester copolymers, such as block copolymers and graft copolymers modified with acrylic, urethane, epoxy, or the like.

[0049] The acrylic resin is not particularly limited, but is preferably composed of alkyl methacrylate and / or alkyl acrylate. Examples of alkyl methacrylate and / or alkyl acrylate include methacrylic acid, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, acrylic acid, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, maleic acid, itaconic acid, acrylamide, N-methylolacrylamide, and diacetone acrylamide. These may be used alone or in combination.

[0050] The urethane resin is preferably a resin obtained by reacting a polyhydroxy compound with a polyisocyanate compound by a known urethane resin polymerization method such as emulsion polymerization or suspension polymerization. Examples of polyhydroxy compounds include polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene glycol, hexamethylene glycol, tetramethylene glycol, 1,5-pentanediol, diethylene glycol, triethylene glycol, polycaprolactone, polyhexamethylene adipate, polyhexamethylene sebacate, polytetramethylene adipate, polytetramethylene sebacate, trimethylolpropane, trimethylolethane, pentaerythritol, polycarbonate diol, and glycerin. Examples of polyisocyanate compounds that can be used include hexamethylene diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, isophorone diisocyanate, an adduct of tolylene diisocyanate and trimethylenepropane, and an adduct of hexamethylene diisocyanate and trimethylolethane.

[0051] Examples of epoxy resins that can be used include sorbitol polyglycidyl ether crosslinkers, polyglycerol polyglycidyl ether crosslinkers, diglycerol polyglycidyl ether crosslinkers, and polyethylene glycol diglycidyl ether crosslinkers. Commercially available epoxy resins may be used, such as the epoxy compounds "Denacol" (registered trademark) EX-611, EX-614, EX-614B, EX-512, EX-521, EX-421, EX-313, EX-810, EX-830, and EX-850 manufactured by Nagase Chemtec Corporation, diepoxy and polyepoxy compounds (SR-EG, SR-8EG, and SR-GLG manufactured by Sakamoto Pharmaceutical Co., Ltd.), and epoxy crosslinkers "EPICLON" (registered trademark) EM-85-75W and CR-5L manufactured by Dainippon Ink Mfg. Co., Ltd., among others. Among these, water-soluble epoxy resins are preferred.

[0052] Next, a description will be given of reactive compounds suitable for the resin layer 1 of the present invention. The reactive compounds may be used alone or in combination of two or more types.

[0053] The oxazoline compound is preferably an oxazoline group-containing copolymer obtained by copolymerizing at least one monomer containing an oxazoline group and at least one other monomer, and has an oxazoline group as a functional group therein.

[0054] In the oxazoline compound, at least one other monomer used for the monomer containing an oxazoline group is a monomer copolymerizable with the monomer containing an oxazoline group, and examples thereof include acrylic acid esters or methacrylic acid esters such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, and 2-ethylhexyl methacrylate, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, and maleic acid, acrylonitrile, and methacrylonitrile. unsaturated nitriles such as those mentioned above, unsaturated amides such as acrylamide, methacrylamide, N-methylolacrylamide, and N-methylolmethacrylamide, vinyl esters such as vinyl acetate and vinyl propionate, vinyl ethers such as methyl vinyl ether and ethyl vinyl ether, olefins such as ethylene and propylene, halogen-containing α,β-unsaturated monomers such as vinyl chloride, vinylidene chloride, and vinyl fluoride, and α,β-unsaturated aromatic monomers such as styrene and α-methylstyrene, and the like can be used alone or in combination.

[0055] Specific oxazoline compounds are not particularly limited, but addition-polymerizable oxazoline group-containing monomers are preferred, such as 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline. These may be used alone or in combination.

[0056] A carbodiimide compound is a compound having at least one carbodiimide group or a cyanamide group, which is a tautomeric form of the carbodiimide group, as a functional group in the molecule. Specific examples of such carbodiimide compounds include dicyclohexylmethanecarbodiimide, dicyclohexylcarbodiimide, tetramethylxylylenecarbodiimide, and urea-modified carbodiimide, and these may be used alone or in combination.

[0057] The melamine compound that can be suitably used in the laminated polyester film of the present invention is a melamine compound having one or more triazine rings and one or more methylol groups in one molecule, and by using such a melamine compound, a crosslinked structure between methylol groups can be formed in the resin layer.

[0058] Examples of melamine compounds that can be used include melamine, methylolated melamine derivatives obtained by condensing melamine with formaldehyde, compounds obtained by reacting methylolated melamine with a lower alcohol to partially or completely etherify the melamine, and mixtures thereof. The melamine compound may be a condensate of a monomer or a dimer or higher polymer, or a mixture thereof. Examples of lower alcohols used for etherification include methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, and isobutanol. The functional group may be an imino group, a methylol group, or an alkoxymethyl group such as a methoxymethyl group or a butoxymethyl group per molecule. Examples of such functional groups include imino-type methylated melamine compounds, methylol-type melamine compounds, methylol-type methylated melamine compounds, and fully alkylated methylated melamine compounds. In particular, examples of methylol melamine compounds include monomethylol melamine, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, and hexamethylol melamine. These may be used alone or in combination.

[0059] Examples of isocyanate compounds that can be used include tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, meta-xylylene diisocyanate, hexamethylene-1,6-diisocyanate, 1,6-diisocyanatehexane, an adduct of tolylene diisocyanate and hexanetriol, an adduct of tolylene diisocyanate and trimethylolpropane, polyol-modified diphenylmethane-4,4'-diisocyanate, carbodiimide-modified diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, 3,3'-bitrylene-4,4' diisocyanate, 3,3'dimethyldiphenylmethane-4,4'-diisocyanate, and meta-phenylene diisocyanate. In particular, it is preferable to use a polymeric isocyanate compound having a plurality of isocyanate groups at the terminals or side chains of a polymer such as a polyester resin or an acrylic resin, since this increases the flexibility and toughness of the resin layer 1 .

[0060] Furthermore, when using a coating composition, the tendency of the isocyanate group to react with water can become a problem. In such cases, blocked isocyanate compounds in which the isocyanate group is masked with a blocking agent or the like can be preferably used in terms of the pot life of the coating material. Typical examples of such blocked isocyanate compounds are those in which the blocking agent volatilizes due to the heat generated during heating and drying processes after application, thereby exposing the isocyanate group and causing a crosslinking reaction. Furthermore, the isocyanate group may be monofunctional or polyfunctional, but polyfunctional blocked polyisocyanate compounds are preferred in that they are easier to increase the crosslink density. Suitable examples of low-molecular-weight or high-molecular-weight compounds having two or more blocked isocyanate groups include tolylene diisocyanate, hexamethylene diisocyanate, a 3-mol adduct of trimethylolpropane with tolylene diisocyanate, polyvinyl isocyanate, vinyl isocyanate copolymers, polyurethane-terminated diisocyanate, a methyl ethyl ketone oxime-blocked compound of tolylene diisocyanate, sodium hyposulfite-blocked compound of hexamethylene diisocyanate, a methyl ethyl ketone oxime-blocked compound of polyurethane-terminated diisocyanate, and a phenol-blocked compound of a 3-mol adduct of trimethylolpropane with tolylene diisocyanate.

[0061] In the infrared shielding structure of the present invention, it is preferable that the resin layer 1 contains an acrylic resin and a polyester resin, and the proportion of the acrylic resin increases and the proportion of the polyester resin decreases from the substrate layer side toward the resin layer 2 side. One method for evaluating whether this requirement is met is to determine the density of the dye in a cross-sectional TEM image of the resin layer 1 in which only the acrylic resin is dyed. When the resin layer 1 contains an acrylic resin and a polyester resin, in the cross-sectional TEM image obtained by this method, a darker dyed area can be determined to have a higher acrylic resin proportion, i.e., a lower polyester resin proportion. On the other hand, a lighter dyed area can be determined to have a lower acrylic resin proportion, i.e., a higher polyester resin proportion. The cross-sectional TEM evaluation method will be described in detail later. In addition to the above method, a method can also be used in which GCIB-TOF-SIMS (GCIB: gas cluster ion beam, TOF-SIMS: time-of-flight secondary ion mass spectrometry) is used to analyze the composition distribution in the depth direction from the resin layer 2 side of the resin layer 1 of the infrared shielding structure toward the substrate layer. In this method, the normalized positive secondary ion intensities of the acrylic resin and polyester resin are measured in the depth direction by GCIB-TOF-SIMS from the surface of the resin layer 1, and areas with high normalized positive secondary ion intensities can be determined to have a high proportion of each resin. The specific measurement method and conditions for GCIB-TOF-SIMS will be described later.

[0062] The increase in the ratio of acrylic resin and the decrease in the ratio of polyester resin from the substrate layer side to the opposite side in resin layer 1 means that the acrylic resin is unevenly distributed on the opposite side of the substrate layer and the polyester resin is unevenly distributed on the substrate layer side in the thickness direction of resin layer 1. Because acrylic resin has excellent adhesion to a resin layer that is laminated in a post-processing step, this embodiment can improve adhesion to another resin layer (resin layer 2 in the embodiment of Figure 1) in a post-processing step. Furthermore, when the substrate layer is a polyester film and the substrate layer and resin layer 1 are in contact with each other, uneven distribution of the polyester resin on the substrate layer side can also improve adhesion between the substrate layer and resin layer 1.

[0063] When the base layer is a polyester film and the base layer is in contact with the resin layer 1, the infrared absorbing particles 1 contained in the resin layer 1 are modified with a polyester resin, and the polyester resin is unevenly distributed on the base layer side, so that the infrared absorbing particles 1 can be easily unevenly distributed on the base layer side. 20 ≧2×X 90 It becomes easy to satisfy the above.

[0064] Regarding the uneven distribution of the acrylic resin and polyester resin in the resin layer 1, it is preferable that the phase with a high acrylic resin content and the phase with a high polyester resin content do not form a clear interface, and that a mixed phase region in which both the acrylic resin and the polyester resin are present exists. The presence of a mixed phase region in the resin layer 1 makes it less likely that peeling will occur between the phase with a high acrylic resin content and the phase with a high polyester resin content.

[0065] The method for forming the resin layer 1 in the infrared shielding structure and laminate of the present invention in such a manner that the proportion of acrylic resin increases and the proportion of polyester resin decreases from the substrate layer side to the opposite side is not limited. For example, when forming the resin layer 1 on the substrate layer by coating a resin composition, the following method can be used. First, a resin composition containing an acrylic resin and a polyester resin is prepared and applied in one step to the film that will serve as the substrate layer. Next, heat treatment is performed under two or more different temperature conditions to dry the coating composition. By forming the resin layer 1 in this manner, the acrylic resin and polyester resin can be unevenly distributed within the resin layer 1 without forming a clear interface. Detailed conditions are described below.

[0066] Generally, acrylic resin and polyester resin have a large difference in surface energy, with acrylic resin having a relatively low surface energy. Normally, phase separation caused by the difference in surface energy can cause the acrylic resin to be unevenly distributed on the side of the resin layer 1 opposite the substrate layer, and the polyester resin to be unevenly distributed on the substrate layer side. However, the thermal energy used in heat treatment is important for the occurrence of phase separation. For example, insufficient thermal energy can result in incomplete phase separation or no phase separation at all. Furthermore, even if sufficient thermal energy is applied, applying too much energy all at once can result in complete phase separation, forming a clear interface between the acrylic resin and the polyester resin.

[0067] The method of performing the heat treatment under different temperature conditions in two or more stages as described above is not particularly limited, but for example, the following method can be used. The first stage is performed at a temperature close to the drying temperature of the solvent, with the main purpose of drying the applied resin composition, and the second stage is performed at a higher temperature than in the first stage with the purpose of promoting phase separation. In this way, by setting the temperature in the second stage higher than that in the first stage, the structure of the resin layer 1 suitable for the present invention can be more significantly expressed.

[0068] In this case, the set temperature for the second stage is preferably 180°C or higher, more preferably 200°C or higher, from the viewpoint of forming a phase-separated structure without a clear interface. The upper limit of the set temperature for the second stage is preferably 300°C, from the viewpoint of the stability of the binder resin used in the resin layer 1. Furthermore, when the set temperature is increased from the first stage to the second stage, it is preferable to increase the ambient temperature at a rate of 5°C / sec or higher, more preferably 10°C / sec or higher, and even more preferably 15°C / sec or higher. The upper limit of the temperature increase rate is preferably 50°C / sec, from the viewpoint of appropriately reducing the thickness of the mixed phase region forming the phase-separated structure, while also suppressing the formation of a two-layer structure in which there is no mixed phase region and a clear interface is formed.

[0069] Furthermore, the heat treatment time in the second heat treatment step is preferably 10 to 40 seconds, more preferably 10 to 20 seconds. When the heat treatment time is within this preferred range, the thickness of the mixed phase region forming the phase-separated structure can be appropriately reduced, while also suppressing the formation of a two-layer structure in which no mixed phase region exists and a clear interface is formed.

[0070] In the infrared shielding structure of the present invention, when the thickness of the resin layer 1 is designated as D1, D1 is not particularly limited, but is preferably 0.01 μm or more and 5.0 μm or less, more preferably 0.05 μm or more and 2.0 μm or less, and even more preferably 0.1 μm or more and 1.0 μm or less. By setting D1 to 0.01 μm or more, it becomes easy to provide a stable resin layer 1 on the film for the base layer. Furthermore, by setting D1 within the above range, it is possible to achieve both heat ray shielding properties and adhesiveness.

[0071] In the resin layer 1 of the infrared shielding structure and laminate of the present invention, when the thickness of the phase mainly composed of an acrylic resin is Da, the thickness of the mixed phase region is Dab, and the thickness of the phase mainly composed of a polyester resin is Db, it is preferable that 0.02D1≦Da+Dab≦0.3D1. By setting Da+Dab in this range, it becomes easy to control the content of the infrared absorbing particles 1 that are unevenly distributed on the base layer side, and it is possible to achieve both improved heat insulation and improved adhesion.

[0072] There are no particular limitations on the method for setting Da+Dab in resin layer 1 within the above-mentioned range. For example, when resin layer 1 is formed by coating a resin composition, the mass ratio of acrylic resin to polyester resin in the resin composition (acrylic resin content (parts by mass) / polyester resin content (parts by mass)), or the mass ratio of acrylic resin component to polyester resin component in the acrylic-modified polyester resin (acrylic resin component content (parts by mass) / polyester resin component content (parts by mass)) can be set to 2 / 98 to 30 / 70.

[0073] The thickness D1 of the resin layer 1 can be measured using a cross-sectional image taken by a transmission electron microscope (TEM), the details of which will be described later. The thickness (Da, Dab, Db) of the resin layer 1 can be calculated by measuring the normalized positive secondary ion intensity of GCIB-TOF-SIMS in the thickness direction, the details of which will be described later. In the laminate of the present invention, the method for adjusting the thickness of the resin layer is not particularly limited and can be appropriately selected from known methods. For example, when the resin layer 1 is formed by coating, a method of adjusting the concentration of solids in a resin composition can be mentioned. More specific methods will be described later.

[0074] The resin layer may also contain various additives, such as lubricants, inorganic particles, organic particles, surfactants, and surface treatment agents, as needed. The content of the reactive compound contained in the resin layer is preferably 70 parts by mass or less, and more preferably 40 parts by mass or less, when the total amount of binder resins in the resin composition used to form the resin layer is 100 parts by mass. By containing the reactive compound in an amount of 70 parts by mass or less, the flexibility, toughness, and other properties of the resin layer can be improved without impairing the heat-shielding properties. This is also preferred because it can be expected to reduce blocking when the laminate is wound up into a roll.

[0075] In the infrared shielding structure of the present invention, it is important that the resin layer 2 contains infrared absorbing particles 2. The infrared absorbing particles 2 in the present invention are different from the infrared absorbing particles 1. The resin layer 2 has shielding properties because it contains the infrared absorbing particles 2, but may also have other functions such as designability, durability, weather resistance, impact resistance, scratch resistance, easy adhesion, and adhesiveness.

[0076] In the infrared shielding structure of the present invention, the infrared absorbing particles 2 preferably contain elemental tungsten, and are more preferably tungsten oxide compounds. The tungsten oxide compounds referred to here may include not only simple tungsten oxides but also tungsten oxides containing metals other than tungsten. The metals other than tungsten referred to here are not particularly limited, and suitable examples include cesium, thallium, indium, and magnesium. In particular, in the present invention, the tungsten oxide compound is preferably cesium tungsten oxide from the viewpoints of a high infrared blocking rate (high heat ray absorption efficiency), low visible light absorption, and stable optical properties.

[0077] The content of the tungsten oxide compound in the resin layer 2 is not particularly limited, but is preferably 1% by mass or more and 80% by mass or less, when the total mass of all components of the resin layer 2 is taken as 100% by mass. When the content of the tungsten oxide compound in the resin layer 2 is 1% by mass or more, the transmittance of light with wavelengths of 900 to 1200 nm can be reduced without increasing the resin layer 2 excessively, thereby improving the handleability of the infrared shielding structure and reducing manufacturing costs. On the other hand, when the content of the tungsten oxide compound in the resin layer 2 is 80% by mass or less, it becomes easier to control the light transmittance by controlling the film thickness, and it is also possible to reduce the shedding of the tungsten oxide compound (heat ray absorbing particles). From the above viewpoints, the content of the tungsten oxide compound in the resin layer 2 is more preferably 10% by mass or more and 75% by mass or less, and even more preferably 20% by mass or more and 70% by mass or less.

[0078] When a tungsten oxide compound is used in the resin layer 2 of the present invention, the resin layer 2 may contain an alkali metal element in an amount of 0.01% by mass to 4% by mass, where the total components forming the resin layer 2 are taken as 100% by mass, in order to improve the light resistance of the resin layer 2. In the present invention, the alkali metal element refers to lithium, sodium, potassium, or rubidium. As long as the alkali metal element is in a form that can be detected by ICP emission spectroscopy, which will be described later, it is not limited to whether the alkali metal element is a simple substance or a compound. However, it is more preferable that the alkali metal element be contained in the resin layer 2 as an alkali metal alkoxide, as this improves the light resistance of the resin layer 2.

[0079] An alkali metal alkoxide is a compound in which the hydrogen of the hydroxyl group of an alcohol is substituted with an alkali metal. For example, potassium alkoxides include potassium tert-butoxide, potassium methoxide, potassium ethoxide, potassium pentoxide, and potassium phenoxide. Among these, potassium tert-butoxide is preferred from the viewpoint of film stability. Furthermore, the organic group possessed by the alkali metal alkoxide preferably has 4 to 20 carbon atoms. Specific examples include potassium tert-butoxide, potassium pentoxide, and potassium phenoxide. A carbon atom number of 4 or more improves stability against moisture and heat, while a carbon atom number of 20 or less improves solubility and dispersibility in solvents. From the above viewpoints, the carbon atom number is more preferably 4 to 10, and even more preferably 4 to 6.

[0080] The resin forming the resin layer 2 is preferably selected from acrylic resin, urethane resin, polyester resin, silanol, etc., and the type is not particularly limited, and these can be used alone or in combination. Taking acrylic resins as an example, it is preferable to use acrylic resins obtained using, as monomers, for example, methacrylic acid, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, acrylic acid, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, glycidyl acrylate, glycidyl methacrylate, 4-hydroxybutyl acrylate glycidyl ether, 4-hydroxybutyl methacrylate glycidyl ether, phenylglycidyl acrylate, epoxy acrylate, epoxy methacrylate, dipentaerythritol hexaacrylate, or the like (monomers may be used alone or in combination).

[0081] Furthermore, the resin forming the resin layer 2 and the mixture serving as its precursor preferably use an initiator, curing agent, or catalyst, as this further accelerates curing. The initiator is preferably one that can initiate or accelerate polymerization, condensation, or crosslinking reactions through anionic, cationic, or radical reactions. The initiator, curing agent, and catalyst are not particularly limited and can be appropriately selected from known initiators and catalysts. The initiator, curing agent, and catalyst may be used alone, or multiple initiators, curing agents, and catalysts may be used in combination. Furthermore, an acidic catalyst, a thermal polymerization initiator, a photopolymerization initiator, etc. may be used in combination, with the use of a photopolymerization initiator being preferred. Examples of acidic catalysts include aqueous hydrochloric acid, formic acid, and acetic acid. Examples of thermal polymerization initiators include peroxides and azo compounds. Examples of photopolymerization initiators include alkylphenone compounds, sulfur-containing compounds, acylphosphine oxide compounds, and amine compounds. As the photopolymerization initiator, alkylphenone compounds are preferred in terms of curability. Specific examples of alkylphenone compounds include 1-hydroxycyclohexylphenylketone, 2.2-dimethoxy-1.2-diphenylethan-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-phenyl)-1-butane, and 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-(4-phenyl)-1-butane. , 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butane, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butane, 1-cyclohexyl-phenyl ketone, 2-methyl-1-phenylpropan-1-one, 1-[4-(2-ethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, etc. These may be used alone or in combination of two or more kinds.

[0082] The thickness D2 of the resin layer 2 of the present invention is not particularly limited, but is preferably 1.0 μm or more and 20 μm or less, more preferably 2.0 μm or more and 10 μm or less, and particularly preferably 2.0 μm or more and less than 5.0 μm. When the thickness D2 of the resin layer 2 is within the above range, it is easy to control the thickness with high precision, which makes it possible to more uniformly achieve the heat-shielding performance and heat-insulating performance provided by the infrared-absorbing particles 2 and to reduce defects such as thermal cracking when attached to glass. Furthermore, by not making D2 excessively large, it is possible to reduce deterioration in color due to the presence of D2. Like D1, D2 can be measured by observing a cross section of the infrared shielding structure in the thickness direction using a TEM (transmission electron microscope) with a length measurement function; the measurement method will be described in detail below.

[0083] As a method for making D2 1.0 μm or more and 20 μm or less, or within the above preferred range, for example, when the resin layer 2 is formed by coating, a method of adjusting the concentration of the solid content in the resin composition can be mentioned. More specific methods will be described later.

[0084] In the infrared shielding structure of the present invention, it is preferable that the thickness D1 of the resin layer 1 and the thickness D2 of the resin layer 2 satisfy D1 < D2. The base material layer, the resin layer 1, and the resin layer 2 are each formed of resins having different compositions. Generally, when the resins constituting each layer are different, the refractive indices of each layer are also different. Generally, in the case of a structure in which layers having different refractive indices are laminated, an iridescent pattern (interference fringes) due to light interference is likely to occur, deteriorating the appearance. By setting D1 and D2 in the above form, it is possible to make it difficult to generate such interference fringes, and it becomes easy to obtain an infrared shielding structure with a good appearance.

[0085] Further, in the form where the infrared shielding structure of the present invention satisfies D1 < D2, it is more preferable that the infrared absorption particles 1 contain tungsten elements and the infrared shielding particles 2 contain tin elements. As described above, cesium-containing tungsten oxide generally tends to have a bluish tint, and the bluish tint becomes stronger as the amount of cesium-containing tungsten oxide in the resin layer and the thickness of the resin layer increase. By forming the infrared shielding structure in the above form, that is, in the form where the thinner layer contains tungsten elements, in addition to making it difficult to generate interference fringes, the bluish tint can also be suppressed, and it becomes easy to obtain an infrared shielding structure with an even better appearance.

[0086] The substrate layer of the infrared shielding structure of the present invention preferably has a laminated structure having at least a layer (A layer) primarily composed of a polyester resin (resin A) and a layer (B layer) primarily composed of a thermoplastic resin (resin B) different from resin A, and the laminated structure has 51 or more layers. Here, the laminated structure refers to a region in which layers A and B, including layers A and B, are alternately stacked in a regular arrangement in the thickness direction. For example, if the laminated structure is composed of layers A and B, the structure is one in which layers A and B are alternately stacked, such as A(BA)n or B(AB)n (n is a natural number representing the number of repeating units). Furthermore, if the laminated structure includes, in addition to layers A and B, a layer (C layer) primarily composed of a third thermoplastic resin different from resin A and resin B, specific examples of the laminated structure include structures in which the layers are stacked in order with a certain regularity, such as C(BA)nC, C(ABC)n, or C(ACBC)n (n is a natural number representing the number of repeating units). Furthermore, 51 or more layers means that the total number of layers repeated in the laminated structure, for example, layers A and B, or layers A, B, and C in the above example, is 51 or more.

[0087] To obtain an infrared shielding structure having a laminated component of this type, it is preferable to use a film having the above-mentioned laminated component as a film for a base layer. Hereinafter, for the purpose of simplifying the explanation, some of the explanations will be given taking as an example a laminated film having a configuration in which layers A and B are alternately laminated, which is one of the preferred embodiments of the present invention, but the same should be understood when three or more thermoplastic resins are used. Hereinafter, a film for a base layer having a laminated component of this type may be referred to as a multilayer film.

[0088] For example, by using such a multilayer film as a film for the base layer, the relationship between the difference in refractive index and the layer thickness of each layer constituting the laminated structure makes it easy to realize functions such as selectively reflecting light in a specific wavelength band through interference reflection or reflecting light of a specific polarization. As a result, in addition to the heat ray shielding, heat insulating properties, and easy adhesion of the resin layer 1, the infrared shielding structure can be endowed with functions such as heat shielding by reflecting infrared rays and deterioration prevention by reflecting ultraviolet rays. In particular, improving the heat shielding properties of the infrared shielding structure reduces temperature increases due to direct sunlight and light reflected from the ground, which leads to energy conservation measures by suppressing temperature increases inside buildings and automobiles when applied to windows.

[0089] Other applications to which an infrared-shielding structure having such a multilayer film as a base layer can be applied include the following examples: By sandwiching an infrared-shielding structure having functions such as heat-shielding properties by reflecting infrared rays and deterioration prevention functions by reflecting ultraviolet rays between two sheets of glass, a laminated glass capable of maintaining high heat-shielding performance for a long period of time can be produced.

[0090] Here, "resin A and resin B are different" means that resin A and resin B have different melting points or crystallization temperatures. "Different melting points or crystallization temperatures" means that either the melting point or the crystallization temperature determined by the measurement method described below differs by 3°C or more. Note that cases where one resin has a melting point and the other does not, or where one resin has a crystallization temperature and the other does not, are also considered to have different melting points or crystallization temperatures. It is more preferable that resin A and resin B be combined to have different melting points and different crystallization temperatures.

[0091] In the multilayer film used in the infrared shielding structure and laminate of the present invention, the difference in the in-plane average refractive index between Layer A and Layer B is preferably 0.03 or more. It is more preferably 0.05 or more, and even more preferably 0.10 or more. When the difference in the in-plane average refractive index between Layer A and Layer B is greater than 0.03, sufficient reflectance is obtained, resulting in improved heat ray blocking performance, for example. One method for achieving the difference in the in-plane average refractive index between Layer A and Layer B within the above range is to use an embodiment in which one of Resins A and B is crystalline and the other is amorphous. Crystallinity here refers to a melting enthalpy of 10 J / g or more measured by differential scanning calorimetry (DSC). On the other hand, amorphousness refers to a melting enthalpy of less than 10 J / g, measured in the same manner. Such a resin combination facilitates the creation of a refractive index difference between Layer A and Layer B during the stretching and heat treatment steps in the production of the multilayer film.

[0092] The combination of resin A and resin B constituting the multilayer film used in the infrared shielding structure and laminate of the present invention is preferably a combination having the same basic skeleton. The basic skeleton here refers to the repeating unit that is most abundant among the repeating units constituting the resin. For example, when polyethylene terephthalate is used as one of the thermoplastic resins, it is preferable that the basic skeleton of the other thermoplastic resin is also an ethylene terephthalate unit, from the viewpoint of easily realizing a highly accurate laminate structure. When resins A and B have the same basic skeleton, the lamination accuracy is high and peeling at the layer interface is less likely to occur.

[0093] Furthermore, a preferred combination of resin A and resin B in the multilayer film used in the infrared shielding structure and laminate of the present invention is one in which the difference in glass transition temperature between them is 20°C or less. If the difference in glass transition temperature between them is greater than 20°C, the thickness of the multilayer film may become less uniform during film formation, leading to poor appearance of the final multilayer film. Furthermore, problems such as overstretching may occur during molding of the multilayer film. It is also preferable that the glass transition temperature of the crystalline resin between resins A and B is lower than that of the amorphous resin. In this case, when the multilayer film is stretched at a stretching temperature appropriate for orienting and crystallizing the crystalline resin, the orientation of the amorphous resin can be suppressed compared to the crystalline resin, making it easier to achieve a difference in the in-plane average refractive index.

[0094] In the multilayer film used in the infrared-shielding construction and laminate of the present invention, examples of dicarboxylic acid units in the polyester resin used as resin A, resin B, and resin C, which is the main component of layer C that can be provided as needed, include structural units such as terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acids (1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,3-naphthalenedicarboxylic acid), 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, adipic acid, suberic acid, sebacic acid, dimer acid, dodecanedioic acid, and cyclohexanedicarboxylic acid, as well as ester-forming derivatives thereof. The acid components from which these structural units are derived may be used alone or in combination, and two or more may also be used, and hydroxy acids such as hydroxybenzoic acid may also be partially copolymerized.

[0095] Examples of diol units that can be used in these resins include ethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, diethylene glycol, polyalkylene glycol, 2,2-bis(4'-β-hydroxyethoxyphenyl)propane, isosorbate, 1,4-cyclohexanedimethanol, spiroglycol, neopentyl glycol, polyethylene glycol, polypropylene glycol, polybutylene glycol, triethylene glycol, tetraethylene glycol, polytetramethylene ether glycol, and ester-forming derivatives thereof. The diol components from which these structural units are derived may be used alone or in combination of two or more.

[0096] More preferred examples of the dicarboxylic acid units constituting these resins include structural units such as terephthalic acid, 2,6-naphthalenedicarboxylic acid, and isophthalic acid, and more preferred examples of the diol units include structural units such as ethylene glycol, 1,4-cyclohexanedimethanol, polyalkylene glycol, polyethylene glycol, tetraethylene glycol, and polytetramethylene ether glycol. These diol components may be used alone or in combination of two or more.

[0097] As mentioned above, resins with different melting points and crystallization temperatures usually have different optical properties. Therefore, by regularly stacking such resins, it becomes easier to reflect light in a specific wavelength band due to the relationship between the difference in the average in-plane refractive index of each layer and the layer thickness. Furthermore, the more layers are stacked, the higher the reflectivity can be obtained over a wider band. From this perspective, the number of layers in the laminated structure is preferably 51 or more, more preferably 201 or more, and even more preferably 401 or more. In such reflection (interference reflection), the greater the total number of A and B layers, the wider the wavelength band and the higher the reflectivity, resulting in a laminated structure with high light-blocking performance. Therefore, although there is no upper limit to the number of layers in the laminated structure from the above perspective, increasing the number of layers in the laminated structure increases the manufacturing cost due to the larger manufacturing equipment and the thicker the film, resulting in poorer handling. Therefore, in reality, the practical range is a total of 1001 layers or less.

[0098] From the viewpoint of further enhancing the heat shielding properties, the infrared shielding structure and laminate of the present invention preferably have a maximum reflectance of 50% or more and 110% or less at wavelengths of 800 to 1000 nm measured from the substrate layer side, and more preferably 80% or more and 110% or less. The higher the maximum reflectance, the higher the heat shielding properties, which is preferable, but from the viewpoint of feasibility, 110% is the upper limit. The reflectance at each wavelength can be measured as a relative reflectance with respect to a white aluminum oxide plate, and details will be described later. The reason why the upper limit of the maximum reflectance exceeds 100% is because this is a relative reflectance with respect to a white aluminum oxide plate.

[0099] Such properties can be achieved by using a multilayer film as a base layer and increasing the difference in the in-plane average refractive index between Layer A and Layer B. Therefore, when the multilayer film is to be a biaxially stretched film, it is preferable to use a multilayer film in which layers containing a crystalline polyester resin as the main component are alternately laminated with layers containing a low refractive index copolymer polyester as the main component that maintains its amorphous nature during stretching or is melted during heat treatment.

[0100] The infrared shielding structure and laminate of the present invention preferably have, on at least one surface, an average reflectance of 15% or less in a wavelength band of 400 nm to 700 nm and an average reflectance of 70% or more in a wavelength band of 850 nm to 1200 nm when light is incident at an incident angle of 10°. This configuration suppresses reflection in the visible range, thereby reducing coloring and glare, and also enables reflection of infrared rays. Therefore, such an infrared shielding structure has excellent transparency and heat-shielding properties.

[0101] An infrared shielding structure having a maximum reflectance of 50% or more and 110% or less in the wavelength range of 800 to 1000 nm can be obtained, for example, by using the above-mentioned multilayer film as a film for the base layer of the infrared shielding structure and increasing the total number of layers A and B and / or the in-plane average refractive index difference between layers A and B. The total number of layers depends on the in-plane average refractive index difference between layers A and B (or the resins A and B that are the main components of these layers), but it is preferable that the total number of layers A and B be 201 or more. By making the total number of layers A and B 201 or more, it becomes easy to achieve a maximum reflectance of 50% or more and 110% or less in the wavelength range of 800 to 1000 nm. Furthermore, when the maximum reflectance in the wavelength range of 800 to 1000 nm is to be 80% or more and 110% or less, it is preferable that the total number of layers A and B be 401 or more.

[0102] To obtain such infrared shielding structures and laminates, it is also preferable that the sum of the optical thicknesses of adjacent layers in the laminated structure of the multilayer film used as the base layer of the infrared shielding structure and laminate be 400 to 700 nm for the majority of the layers. The optical thickness here refers to the product of the layer thickness of each layer and the refractive index of the resin constituting the layer, and the sum of the optical thicknesses of adjacent layers is a factor that determines the wavelength at which interference reflection occurs in the laminated film. Interference reflection from a laminated structure in which the sum of the optical thicknesses of adjacent layers is 400 to 700 nm typically occurs in the wavelength range of approximately 800 to 1400 nm. Therefore, by satisfying these conditions, it becomes easy to achieve a maximum reflectance of 50% or more and 110% or less in the wavelength range of 800 to 1000 nm. Furthermore, the magnitude of the reflectance due to interference reflection increases as the number of layers and the difference in the in-plane average refractive index between adjacent layers increases. In a multilayer film having a stacked structure in which the sum of the optical thicknesses of adjacent layers for the majority of layers is 400 to 700 nm, the maximum reflectance in the wavelength range of 800 to 1000 nm can be more efficiently improved.

[0103] For example, when polyethylene terephthalate with a refractive index of 1.66 and polyethylene terephthalate copolymerized with spiroglycol and cyclohexanedicarboxylic acid with a refractive index of 1.55 are used as resins A and B, the number of layers where the sum of the optical thicknesses of adjacent layers is 400 to 700 nm is approximately 201 or more, depending on conditions such as the stretching ratio, in order to achieve a maximum reflectance of 50% to 110% in the 800 to 1000 nm wavelength band. As the difference in the average in-plane refractive index between resins A and B increases, the number of layers where the sum of the optical thicknesses of adjacent layers is 400 to 700 nm required to achieve a maximum reflectance of 50% to 110% in the 800 to 1000 nm wavelength band decreases. If the difference in the average in-plane refractive index between layers A and B is 0.3 or more, sufficient reflectance can be achieved even with a total of 51 layers where the sum of the optical thicknesses of adjacent layers is 400 to 700 nm, depending on conditions such as the stretching ratio. Furthermore, when polyethylene terephthalate with a refractive index of 1.66 and polyethylene terephthalate copolymerized with spiroglycol and cyclohexanedicarboxylic acid with a refractive index of 1.55 are used as the thermoplastic resin, the range of layer thickness required to make the sum of the optical thicknesses of adjacent layers 400 to 700 nm is approximately 120 to 220 nm.

[0104] Another example of a laminated film having a maximum reflectance of 50% or more and 110% or less in the wavelength band of 800 to 1000 nm is one in which the optical thicknesses of adjacent layers A and B simultaneously satisfy the following formulas (1) and (2): λ=2(n α d α +n β d β ) (1) n α d α =n β d β (2) where λ is the reflected wavelength, n α is the in-plane refractive index of layer A, d α is the thickness of layer A, n β is the in-plane refractive index of layer B, d βis the thickness of layer B. Having a layer thickness distribution that simultaneously satisfies both formulas (1) and (2) can eliminate even-order reflections. Therefore, with such a layer thickness distribution, the maximum reflectance in the 800-1000 nm wavelength band can be increased while the average reflectance in the visible light wavelength range of 400-700 nm can be reduced. As a result, the multilayer film has excellent transparency and heat-ray blocking properties. Generally, the refractive index of a film formed from a thermoplastic resin in a sheet form after stretching is approximately 1.4-1.9. Therefore, a film that suppresses even-order reflections can be obtained by setting the thickness ratio of adjacent layers A and B (layer A thickness / layer B thickness) to 0.7 or more and 1.4 or less. Therefore, it is preferable that the thickness ratio of adjacent layers A and B (layer A thickness / layer B thickness) be 0.7 or more and 1.4 or less. From the above viewpoint, the thickness ratio is more preferably 0.8 or more and 1.2 or less.

[0105] In one embodiment of the multilayer film used in the infrared shielding structure and laminate of the present invention, the in-plane average refractive index of at least one surface is 1.68 or more and 1.80 or less. When the in-plane average refractive index of at least one surface is 1.68 or more, it becomes easy to set the maximum reflectance in the wavelength band of 800 to 1000 nm to 50% or more and 110% or less. On the other hand, when the in-plane average refractive index of at least one surface is 1.80 or less, differences in chemical structure are suppressed, resulting in good lamination between resin A and resin B, and reducing clouding of the multilayer film and peeling at the interface between layer A and layer B.

[0106] An example of a method for achieving an in-plane average refractive index of 1.68 to 1.80 on at least one surface of a multilayer film is a method in which the main dicarboxylic acid unit of resin A is a naphthalenedicarboxylic acid unit. This embodiment makes it easy to achieve a refractive index difference between layer A and layer B, making it easier to obtain a laminated polyester film with better reflective performance. Furthermore, in order to increase the in-plane average refractive index difference between layer A and layer B, it is also preferable that resin B be an amorphous resin. To incorporate naphthalenedicarboxylic acid into the dicarboxylic acid constituents of resin A of the multilayer film used in the infrared shielding structure and laminate of the present invention, a method can be used in which naphthalenedicarboxylic acid is included in the dicarboxylic acid constituents as a raw material for the polyester resin that constitutes resin A.

[0107] The layer thickness distribution of the multilayer film used in the infrared shielding structure and laminate of the present invention is preferably a constant layer thickness distribution from one side of the multilayer film to the opposite side, a layer thickness distribution that increases or decreases from one side of the multilayer film to the opposite side, a layer thickness distribution in which the layer thickness increases from one side of the multilayer film toward the center of the film and then decreases, a layer thickness distribution in which the layer thickness decreases from one side of the multilayer film toward the center of the film and then increases, or a combination of these distributions. The preferred way in which the layer thickness distribution changes is a continuous change such as a linear, geometric, or difference progression, or a stepwise change in layer thickness where approximately 10 to 50 layers have approximately the same layer thickness.

[0108] The multilayer film used in the infrared shielding structure and laminate of the present invention can preferably have protective layers on both surface layers, each having a thickness of 1% or more of the thickness of the multilayer film itself, and each protective layer preferably has a thickness of 4% or more of the total thickness of the multilayer film. Increasing the thickness of the protective layers leads to the suppression of flow marks during film formation, improved accuracy of the actual layer thickness relative to the design, suppression of deformation of thin layers in the multilayer film during and after lamination with other films or molded articles, and improved pressure resistance. The upper limit of the thickness of the protective layer is 20% from the viewpoint of ensuring the laminated components necessary for the generation of interference reflection while suppressing an increase in the thickness of the multilayer film. The thickness of the multilayer film is not particularly limited, but is preferably 20 μm to 300 μm, for example. A thickness of 20 μm or more increases the rigidity of the multilayer film, ensuring ease of handling. A thickness of 300 μm or less prevents the multilayer film from becoming excessively rigid, improving formability.

[0109] Hereinafter, preferred methods for producing infrared-shielding structures and laminates will be described using as an example a multilayer film in which polyethylene terephthalate is used as the resin A constituting layer A and a polyethylene terephthalate copolymer (polyethylene terephthalate copolymerized with 20 to 40 mol % of a cyclohexanedimethanol component) is used as the resin B constituting layer B, as the base layer film. Of course, the infrared-shielding structure of the present invention should not be construed as being limited to this example. Furthermore, the laminated structure of this multilayer film can be easily realized by a method similar to that described in paragraphs

[0053] to

[0063] of JP-A-2007-307893.

[0110] Each resin is prepared in the form of pellets or the like. The pellets are dried in hot air or under vacuum, as necessary, and then fed to separate extruders. The resins are heated and melted in the extruder at 280 to 300°C. The resin extrusion rate is uniformed using a gear pump or the like, and foreign matter and denatured resins are removed through a filter or the like. These resins are molded into the desired shape through a die and then discharged. The multilayered sheet discharged from the die is then extruded onto a cooling body such as a casting drum, where it is cooled and solidified to form a cast film. In this case, it is preferable to use a wire-, tape-, needle-, or knife-shaped electrode to apply electrostatic force to the cooling body such as a casting drum for rapid solidification. Other preferable methods include blowing air from a slit-, spot-, or planar-shaped device to rapidly solidify the resin by contacting it with a cooling body such as a casting drum, or using a nip roll to rapidly solidify the resin by contacting it with a cooling body.

[0111] In this process, resins A and B are melt-kneaded in separate extruders and fed into a multi-layer lamination device through separate channels. While multi-manifold dies, feed blocks, static mixers, and the like can be used as multi-layer lamination devices, it is particularly preferable to use a feed block with 51 to 1001 fine slits to efficiently achieve the configuration of the present invention. The use of such a feed block prevents the device from becoming excessively large, reduces the amount of foreign matter caused by thermal degradation, and enables high-precision lamination when the number of layers is 51 to 1001. Furthermore, the lamination precision in the width direction is significantly improved compared to conventional techniques. Furthermore, with such a feed block, the thickness of each layer can be adjusted by the shape (length and width) of the slits, making it easy to achieve any desired layer thickness. The molten multi-layer laminate thus formed into the desired layer configuration is introduced into a die, and a cast film is obtained as described above.

[0112] The cast film thus obtained is preferably biaxially stretched. Here, biaxial stretching refers to stretching in the longitudinal direction and the width direction. Stretching may be performed in the two directions sequentially or simultaneously. Furthermore, re-stretching may be performed in the longitudinal direction and / or the width direction.

[0113] First, we will explain the case of sequential biaxial stretching. In the case of sequential biaxial stretching, stretching in the longitudinal direction (longitudinal stretching) is usually performed followed by stretching in the width direction (transverse stretching). Here, stretching in the longitudinal direction refers to stretching to impart molecular orientation to the film in the longitudinal direction, and is usually performed by varying the peripheral speed of rolls. This stretching can be performed in one stage or in multiple stages using multiple pairs of rolls. The stretching ratio varies depending on the type of resin, but is usually preferably 2 to 15 times, and when polyethylene terephthalate is used as resin A, 2 to 7 times is particularly preferred. In addition, the stretching temperature is preferably the glass transition temperature of the resin with the highest glass transition temperature that constitutes the film to that glass transition temperature + 100°C. Note that, hereinafter, the glass transition temperature of the resin with the highest glass transition temperature that constitutes the film may be referred to as the "maximum glass transition temperature."

[0114] The uniaxially stretched film thus obtained is subjected to a surface treatment such as corona treatment, flame treatment, or plasma treatment as required, and then subjected to a step of applying a resin composition to form the resin layer 1. The method for forming the resin layer 1 will be described in detail later.

[0115] Next, widthwise stretching refers to stretching to impart widthwise orientation to the film. Typically, a uniaxially stretched film obtained by longitudinal stretching is conveyed using a tenter while holding both widthwise ends with multiple clips, and the film is stretched widthwise by widening the distance between the opposing clips. The stretching ratio varies depending on the type of resin, but is typically preferably 2 to 15 times. When polyethylene terephthalate is used as Resin A, a ratio of 2 to 7 times is particularly preferred. In particular, for multilayer films used in the infrared shielding structure of the present invention, the widthwise stretching ratio is preferably 4 times or more, and increasing the widthwise stretching ratio is effective in improving the uniformity of the reflection band and the uniformity of the average reflectance. Furthermore, the stretching temperature is preferably between the maximum glass transition temperature and the maximum glass transition temperature + 120°C.

[0116] The biaxially stretched film is preferably heat-treated in a tenter at a temperature equal to or higher than the stretching temperature and equal to or lower than the melting point of thermoplastic resin A to impart flatness and dimensional stability. Heat treatment improves the dimensional stability of the film. After heat treatment, the film is uniformly and slowly cooled to room temperature and wound up. If necessary, a relaxation treatment or the like may be performed during the heat treatment and slow cooling process.

[0117] Next, simultaneous biaxial stretching will be described. In the case of simultaneous biaxial stretching, the obtained cast film is subjected to a surface treatment such as corona treatment, flame treatment, or plasma treatment as necessary, and then a resin layer is formed by in-line coating.

[0118] The cast film is then introduced into a simultaneous biaxial tenter, where it is conveyed while its widthwise ends are held with clips and stretched simultaneously and / or stepwise in the longitudinal and width directions. Tenter types that can be used as simultaneous biaxial stretching machines include pantograph, screw, drive motor, and linear motor types. Drive motor and linear motor types are preferred, as they allow for arbitrary stretching ratios and relaxation treatment at any desired location. The stretching ratio varies depending on the type of resin, but an area ratio of 6 to 50 times is generally preferred. When polyethylene terephthalate is used as thermoplastic resin A, an area ratio of 8 to 30 times is particularly preferred. In particular, in the case of simultaneous biaxial stretching, it is preferable to maintain the same stretching ratio in the longitudinal and width directions and to ensure that the stretching speeds are approximately the same in order to suppress in-plane orientation differences. Furthermore, the stretching temperature is preferably between the maximum glass transition temperature and the maximum glass transition temperature + 120°C.

[0119] The biaxially stretched film is preferably subsequently heat-treated in a tenter at a temperature equal to or higher than the stretching temperature and lower than the melting point to impart flatness and dimensional stability. During this heat treatment, it is preferable to instantly relax the film in the longitudinal direction immediately before and / or after entering the heat treatment zone to suppress the distribution of the main orientation axis in the width direction. After the heat treatment, the film is uniformly and slowly cooled, cooled to room temperature, and wound up. If necessary, relaxation treatment may be performed in the longitudinal and / or width directions during the slow cooling period following the heat treatment. Preferably, the film may be instantly relaxed by 1 to 5% in the longitudinal direction immediately before and / or after entering the heat treatment zone.

[0120] A method for forming the resin layer 1 on the multilayer film thus obtained can be a method of applying a resin composition to at least one surface of the multilayer film to form the resin layer 1. In this method, the resin composition contains at least infrared-absorbing particles 1 and a binder resin. The infrared-absorbing particles 1 contained in the resin composition preferably contain tin, and more preferably contain an acrylic resin and a polyester resin. When applying such a resin composition to a thermoplastic resin film, the resin composition may contain a solvent. That is, each resin component may be dissolved or dispersed in a solvent to form a coating liquid, which may then be applied to the multilayer film. After application, the solvent is dried and the resulting film is heated to obtain a laminate in which the resin layer 1 is laminated on the multilayer film. In the present invention, an aqueous solvent is preferably used as the solvent. The use of an aqueous solvent not only prevents rapid evaporation of the solvent during the heating process, allowing for the formation of a stable resin layer 1, but also provides an advantage in terms of environmental impact.

[0121] Here, the aqueous solvent refers to water or a mixture of water and a water-soluble organic solvent, such as an alcohol such as methanol, ethanol, isopropyl alcohol, or butanol, a ketone such as acetone or methyl ethyl ketone, or a glycol such as ethylene glycol, diethylene glycol, or propylene glycol, in any ratio.

[0122] The resin composition can be applied to a multilayer film by either an in-line coating method or an off-coating method, with the in-line coating method being preferred. The in-line coating method is a method in which coating is performed within the film production process. Specifically, it refers to a method in which coating is performed at any stage between melt extrusion of a thermoplastic resin and winding up. Typically, coating is performed on either an unstretched (unoriented) polyester film (A film) in a substantially amorphous state obtained by melt extrusion and quenching, a uniaxially stretched (uniaxially oriented) polyester film (B film) that has been subsequently stretched in the longitudinal direction, or a biaxially stretched (biaxially oriented) polyester film (C film) that has been further stretched in the width direction and has not yet been heat-treated.

[0123] In the present invention, a preferred method is to apply a resin composition to either the A film or the B film of a polyester film before the crystal orientation is complete, evaporate the solvent, and then stretch the polyester film uniaxially or biaxially and heat it to complete the crystal orientation of the polyester film and provide the resin layer 1. This method has the advantage of reducing production costs because it allows the production of a film for the base layer, the application of the resin composition, the drying of the solvent, and heating (i.e., the formation of the resin layer) to be carried out simultaneously. Furthermore, it is easy to treat the resin layer 1 at a high temperature of, for example, 200°C or higher for 10 to 40 seconds to form an optimal phase-separated structure. Furthermore, it is also easy to reduce the thickness of the resin layer 1 by stretching it after coating.

[0124] Among these, the method of applying the resin composition to a film (film B) uniaxially stretched in the longitudinal direction, drying the solvent, and then stretching the film in the width direction and heating is excellent. This is because, compared to the method of applying the resin composition to an unstretched film and then biaxially stretching it, this method requires one less stretching step after coating, making it less likely for defects or cracks to occur in the resin layer 1 due to stretching, and making it possible to form a resin layer 1 with excellent transparency and smoothness.

[0125] On the other hand, the offline coating method is a method in which the above-mentioned A film is uniaxially or biaxially stretched and heat-treated to complete the crystal orientation of the polyester film, or the A film is coated with a resin composition in a step separate from the film production process. In the present invention, from the viewpoints of the flatness of the laminate in which the resin layer 1 is laminated on the multilayer film and the adhesion between the multilayer film and the resin layer 1, it is preferable to form the resin composition by the inline coating method.

[0126] The best method for forming resin layer 1 in the present invention is to apply a resin composition using an aqueous solvent to a polyester film using an in-line coating method, followed by heat treatment under two or more different set conditions. As described above in more detail, for example, the first stage is performed at a temperature near the drying temperature of the solvent, primarily for the purpose of drying the applied resin composition, and the second stage is performed at a higher temperature than the first stage to promote phase separation. More specifically, the resin composition is applied to film B, and the first stage is performed at a temperature near the drying temperature of the aqueous solvent, primarily for the purpose of drying the applied resin composition. The second stage is performed at a high temperature of 180°C or higher, preferably 200°C or higher, which is preferred for forming an optimal phase-separated structure in resin layer 1. The second stage is preferably performed for 10 to 40 seconds.

[0127] When preparing a resin composition for forming a resin layer, it is preferable to use an aqueous solvent. The resin composition can be prepared by mixing and stirring infrared-absorbing particles, optionally dispersed in water, a binder resin or reactive compound, optionally dispersed or solubilized in water, and an aqueous solvent in any order at a desired weight ratio. Next, various additives, such as lubricants, inorganic particles, organic particles, surfactants, antioxidants, and thermal initiators, can be added as needed and mixed and stirred in any order to the extent that they do not deteriorate the properties of the resin layer 1 formed from the resin composition. Mixing and stirring can be performed by shaking the container by hand, using a magnetic stirrer or stirring blade, ultrasonic irradiation, vibration dispersion, etc.

[0128] The resin composition can be applied to the base layer film by any known coating method, such as bar coating, reverse coating, gravure coating, die coating, or blade coating. From the viewpoint of appropriate coating thickness and viscosity, bar coating and gravure coating are preferred. In the infrared shielding structure of the present invention, the method for adjusting the thickness of the resin layer is not particularly limited and can be appropriately selected from known methods. For example, in the case of a bar coating method, the groove depth of the bar is adjusted; in the case of a gravure coating method, the amount of coating liquid supplied is adjusted; or, regardless of the coating method, the concentration of solids in the resin composition is adjusted.

[0129] The method for forming the resin layer 2 on the laminate in which the base layer and the resin layer 1 are laminated is not particularly limited, and examples thereof include a method of forming the resin layer 2 by applying a resin composition to the surface layer of the resin layer 1, and a method of transferring a resin layer 2 that has been formed separately in advance onto the resin layer 1. In the method of forming the resin layer by applying a resin composition, the method for applying the resin composition and the method for adjusting the thickness are as described above.

[0130] The infrared shielding structure of the present invention preferably has an adhesive layer on the surface of the substrate layer opposite to the resin layer 1, and the adhesive layer contains an ultraviolet (UV) absorber. The infrared shielding structure of the present invention is suitably used as a glass laminate in which it is bonded to one surface of glass, and the glass and the infrared shielding structure can be bonded via an adhesive layer. It is preferable that the adhesive layer contains a UV absorber, because this can prevent the infrared shielding structure from being deteriorated by ultraviolet rays when sunlight is incident from the glass side.

[0131] The adhesive layer used in the glass laminate of the present invention is not particularly limited, and commonly used adhesive layers such as acrylic, silicone, urethane, rubber, etc. can be used. The UV absorber contained in the adhesive layer of the present invention is not particularly limited as long as it absorbs light in the wavelength range of 300 to 400 nm, and examples include general-purpose UV absorbers that absorb ultraviolet light in the wavelength range of 380 nm or less, and visible light absorbing dyes that can cut light near the boundary between the ultraviolet range and the visible light range (around 380 to 430 nm).

[0132] General-purpose UV absorbers are generally specialized in absorbing UV rays in the wavelength range below 380 nm, and are characterized by poor absorption of light near the boundary between the UV and visible light ranges (around 380 to 430 nm). However, by incorporating them at high concentrations, or by using absorbers with absorption capabilities up to the visible light range (described below), it is possible to achieve wavelength blocking near the boundary between the UV and visible light ranges (380 to 430 nm). Commercially available general-purpose UV absorbers that can independently block wavelengths in the UV range and near the boundary between the UV and visible light ranges (380 to 430 nm) include, for example, compounds represented by the structure 2-(5-chloro-2H-benzotriazol-2-yl)-6-tert-butyl-4-methylphenol and 2,4,6-tris(2-hydroxy-4-hexyloxy-3-methylphenyl)-1,3,5-triazine. In addition, UV absorbers with a variety of skeletal structures, including benzotriazoles, benzophenones, benzoates, triazines, benzoxazinones, salicylic acids, and benzoxazines, can also be used.

[0133] Visible light-absorbing dyes generally excel at blocking short-wavelength visible light, but lack the ability to block ultraviolet light below 380 nm. To block light in the general ultraviolet range simply by incorporating a visible light-absorbing dye, a high concentration is required, with the exception of some visible light-absorbing dyes described below. Furthermore, most visible light-absorbing dyes generally have the property of broadly blocking a wide wavelength range. When incorporated at high concentrations, they absorb visible light at wavelengths longer than the desired wavelength range, which can prevent excellent transparency. Furthermore, there are few visible light-absorbing dyes that have the property of blocking a narrow band near the boundary between the ultraviolet and visible light ranges, particularly in the wavelength range of 380 to 440 nm. Therefore, it is desirable to select and use a visible light-absorbing dye with a specific structure. Examples of visible light absorbing dyes that can achieve wavelength cutoff in the ultraviolet region and near the border between the ultraviolet and visible light regions (380 nm to 430 nm) by adding them alone include "Lumogen" (registered trademark) F Violet 570 manufactured by BASF Ltd. Since general-purpose UV absorbers and / or visible light absorbing dyes each have their own areas of expertise, in order to prevent bleed-out due to high concentration addition and the associated process contamination, it is more preferable to effectively combine one or more general-purpose UV absorbers and one or more visible light absorbing dyes within a range that does not cause unnecessary coloring. When two or more general-purpose UV absorbers and / or visible light absorbing dyes are used in combination, the UV absorbers may have the same skeletal structure, or UV absorbers with different skeletal structures may be combined.

[0134] The infrared shielding structure and laminate of the present invention are suitably used as glass laminates in which the structure and laminate are bonded to one surface of glass, and as laminated glass in which the laminate is inserted between two pieces of glass and two other resin layers, but are most suitable as windows in which glass is provided on the surface of the pressure-sensitive adhesive layer opposite the substrate layer. The window of the present invention is characterized by comprising glass, a pressure-sensitive adhesive layer, and the infrared shielding structure of the present invention in this order, with the substrate layer being located closer to the glass than the resin layer 2. This embodiment is further suitable for windows in which the glass side is the sunlight incident side.

[0135] The glass used in the window of the present invention is not particularly limited, and commonly used transparent plate glass can be used, such as clear glass, float plate glass, polished plate glass, patterned plate glass, wired plate glass, lined plate glass, infrared absorbing plate glass, infrared reflecting plate glass, and green glass.

[0136] A window using the infrared shielding structure of the present invention has excellent heat shielding performance and transparency on the inside, and is therefore particularly suitable as heat shielding glass for use in automobiles, building windows, and the like. [Example]

[0137] The infrared shielding structure of the present invention will be described in more detail below using examples, but the infrared shielding structure of the present invention is not limited to these examples.

[0138] [Methods for measuring physical properties and evaluating effects] The methods for evaluating the physical properties and the effects are as follows.

[0139] (1) Identification of the base layer The composition of the resin constituting the base layer was confirmed by the following method. First, the presence or absence of peaks derived from the bonds between the atoms in the resin structure was confirmed by Fourier transform infrared spectroscopy (FT-IR or ATR). Furthermore, proton nuclear magnetic resonance spectroscopy ( 1 Using H-NMR, the chemical shift position, which is derived from the position of hydrogen atoms in the resin structure, and the proton absorption line area, which is derived from the number of hydrogen atoms, were confirmed. These results were combined and comprehensively confirmed to identify the resin that constitutes the base layer. Furthermore, mass peaks were confirmed using gas chromatography-mass spectrometry (GC-MS) as needed. The above analyses were performed on samples scraped from the infrared shielding structure and laminate with a blade knife.

[0140] (2) Thickness of Resin Layer 1 and Resin Layer 2 The infrared shielding structure and laminate were stained with RuO4 and / or OsO4. The infrared shielding structure and laminate were then frozen and cut in the thickness direction (perpendicular to the infrared shielding structure and laminate surfaces) to obtain 10 ultrathin section samples for cross-sectional observation. The cross-sections of each sample were observed at 10,000 to 1,000,000 magnifications using a TEM (transmission electron microscope: Model H7100FA, manufactured by Hitachi, Ltd.) to obtain cross-sectional photographs. The thicknesses of resin layer 1 and resin layer 2 for each sample were measured using the microscope's length measurement function. The measured values ​​for resin layer 1 and resin layer 2 for the 10 samples were averaged to obtain the thickness D1 of resin layer 1 and the thickness D2 of resin layer 2.

[0141] (3) Confirmation of the phase separation state of resin layer 1 First, the composition distribution in the depth direction was analyzed from the side opposite to the substrate layer (resin layer 2 side) of resin layer 1 of the infrared shielding structure using the analytical method GCIB-TOF-SIMS (GCIB: gas cluster ion beam, TOF-SIMS: time-of-flight secondary ion mass spectrometry). The measurement conditions were as follows: <Sputtering conditions> Ion source: Argon gas cluster ion beam (Ar-GCIB) <Detection conditions> Primary ion: Bi 3++ (25kV) Secondary ion polarity: positive Mass range: m / z 0~1500 Measurement range: 300 x 300 μm 2 Measurement vacuum degree: 4×10 -7 Pa or less Using the above measurement conditions, a profile of the absolute positive secondary ion intensity of each component versus sputtering time was obtained using GCIB-TOF-SIMS. An approximate straight line was calculated for 100 consecutive points in the profile of the absolute positive secondary ion intensity corresponding to the main component of the substrate layer identified in (1). Of the 100 points with a slope of ±15 or less, the average of the 100 points located closest to the inner layer (substrate side) was defined as the "absolute substrate intensity." The sputtering time at which the intensity was half the calculated "absolute substrate intensity" was calculated, designated the "half-intensity sputtering time," and this point was defined as the boundary between resin layer 1 and the substrate layer. In other words, the sputtering time from 0 to the half-intensity sputtering time represents the component distribution of the resin layer, while the period after the half-intensity sputtering time represents the component distribution of the substrate layer.

[0142] Next, we will describe a method for converting the sputtering time in the GCIB-TOF-SIMS profile of absolute positive secondary ion intensity into the thickness D1 of the resin layer 1. The thickness D1 of the resin layer 1 obtained by the measurement in (2) above was divided by the 1 / 2 intensity sputtering time calculated above to obtain the etching rate, and the sputtering time was converted into the thickness D1 of the resin layer 1 based on this etching rate, thereby obtaining a profile of absolute positive secondary ion intensity of each component relative to the thickness D1 of the resin layer 1 in GCIB-TOF-SIMS.

[0143] Next, a method for converting the absolute positive secondary ion intensity of each component into the normalized positive secondary ion intensity of each component will be described. The substrate absolute intensity calculated by the above method is normalized as 1, and the normalized positive secondary ion intensity of each component is obtained from the absolute positive secondary ion intensity of each component. Of the normalized positive secondary ion intensities of each component, the normalized intensity at a position 20% of the thickness from the substrate layer side of the resin layer 1 is defined as A. 20 , the normalized strength at the position of 90% of the thickness from the base layer side of the resin layer 1 is A 90 It was decided.

[0144] In addition, the positive secondary ions of acrylic resin are, for example, 69 C4H5O + , the positive secondary ions of polyester resin are, for example, 104 C7H4O +Here, "a position 20% in thickness from the base layer side of the resin layer 1" refers to a thickness position closest to the thickness D1×20 / 100 of the resin layer 1 when viewed from the base layer side of the resin layer 1. Similarly, "a position 90% in thickness from the base layer side of the resin layer 1" refers to a thickness position closest to the thickness D1×90 / 100 of the resin layer 1 when viewed from the base layer side of the resin layer 1.

[0145] From the profile of the absolute positive secondary ion intensity of each component with respect to the thickness D1 of the resin layer 1 by GCIB-TOF-SIMS obtained above, the phase separation state of the resin layer, whether it existed or not, and the thickness of each phase (Da, Dab, Db) were confirmed and measured. Note that in the profile of the absolute positive secondary ion intensity of each component with respect to the thickness D1 of the resin layer 1 by GCIB-TOF-SIMS, 0.0≦A 90 / A 20 <0.5 or 2.0 90 / A 20 When the above condition is satisfied, it is determined that each resin is phase-separated. In addition, in the GCIB-TOF-SIMS profile of the absolute positive secondary ion intensity of each component against the thickness D1 of the resin layer 1, the region of thickness ±1% from the point where the profiles of each component intersect is defined as the mixed phase region.

[0146] (4) X of resin layer 1 20 , X 90 The cross section of the resin layer 1 obtained by cutting the infrared shielding structure parallel to the film thickness direction was analyzed using X-ray photoelectron spectroscopy (XPS). 20 , and the detection sensitivity at the 90% thickness position X 90 was calculated.

[0147] (5) Melting point, crystallization temperature, enthalpy of fusion ​A 5 mg sample was collected by scraping with a cutter or blade knife, and measured and calculated using a differential scanning calorimeter (DSC) robot DSC-RDC220 manufactured by Seiko Electronics Co., Ltd., in accordance with JIS-K-7122 (1987). More specifically, the sample was heated from 25°C to 300°C at a rate of 5°C / min, and the integrated value from the baseline within a range of ±20°C from the melting point was taken as the enthalpy of fusion. The melting point here was defined as the point at which the difference from the baseline on the DSC chart was minimal. The crystallization temperature was defined as the point at which the difference from the baseline on the DSC chart was maximal at the exothermic peak lower than the melting point.

[0148] (6) Layer thickness, number of layers, and layer structure The layer structure of the base layer of the infrared shielding structure and laminate was confirmed by observation with a transmission electron microscope (TEM) of samples cut out in cross sections parallel to the thickness direction (thickness cross section) using a microtome. More specifically, a transmission electron microscope H-7100FA (manufactured by Hitachi, Ltd.) was used to observe the thickness cross section of the film at 10,000 to 40,000 times magnification at an accelerating voltage of 75 kV, and photographs were taken. The layer structure was confirmed using the obtained image and the TEM's scale function, and the thickness of each layer was measured. In some cases, staining techniques using known substances such as RuO4 and OsO4 were used to obtain high contrast.

[0149] (7) Integrity of infrared shielding structures and laminates The quality of the infrared shielding structure and laminate was evaluated by visually inspecting the flatness (presence or absence of deformation) of the infrared shielding structure and laminate, and the evaluation was based on the following criteria. A: No deformation was observed in the infrared shielding structure and the laminate. B: Deformation was observed in the infrared shielding structure and the laminate.

[0150] (8) Adhesion test 1 mm on the resin layer 1 side of the laminate and on the resin layer 2 side of the infrared shielding structure 2100 pieces of cross-cut paper were placed in the box, and "Sellotape" (registered trademark) (Nichiban Co., Ltd., CT405AP) was attached. Then, a hand roller was used to apply 1.5 kg / cm 2 After pressing with a load of 1000, the laminate and the infrared shielding structure rapidly peeled off in a direction 90 degrees. The adhesion was evaluated based on the number of remaining gratings and rated on a three-level scale according to the following criteria. The evaluation was based on the average value of 10 runs. A and B were practically acceptable levels, and C was deemed problematic in practical use. A: 80 to 100 lattices remained. B: 50 to 79 lattices remained. C: 0 to 49 lattices remained.

[0151] (9) Visibility (interference patterns) A sample measuring 8 cm x 8 cm was cut out from the infrared shielding structure, and black glossy tape was attached to the surface of the base layer opposite resin layer 1, taking care not to trap air bubbles. This sample was placed 30 cm directly below a three-wavelength fluorescent lamp (three-wavelength daylight white (F·L 15EX-N 15W) manufactured by Matsushita Electric Industrial Co., Ltd.) in a dark room, and the degree of interference fringes was visually observed while changing the viewing angle, and evaluated according to the following criteria. A rating of B or higher was considered good. A: No interference patterns were visible or almost no interference patterns were visible. B: Weak interference patterns were visible. C: Strong interference patterns were observed.

[0152] (10) Preparation of glass laminate A glass laminate was produced by stacking transparent plate glass, an adhesive layer, and the infrared shielding structures of Examples 1 and 13 and Comparative Example 1 in the order shown in Table 3 using a LAMINATOR 0303S manufactured by Nisshinbo Co., Ltd. The transparent plate glass used was 100 mm wide and 100 mm long. The adhesive layers used were the following adhesive layer 1 and adhesive layer 2. Adhesive layer 1: "Finetack" (registered trademark) CT-6030 manufactured by DIC Corporation, "Finetack" (registered trademark) curing agent DN manufactured by DIC Corporation, and "Tinuvin" (registered trademark) manufactured by BASF Japan Ltd. ) 477 in a mass ratio of 100:1:2 to the solid content of the general-purpose UV absorber. Adhesive layer 2: An acrylic adhesive layer containing no UV absorber, made by mixing DIC Corporation's "Finetack" (registered trademark) CT-6030 and DIC Corporation's "Finetack" (registered trademark) hardener DN at a solids mass ratio of 100:1.

[0153] (11)Reflectance The reflectance of the samples was measured using a Hitachi spectrophotometer (U-4100 Spectrophotometer) with an integrating sphere attached to the basic configuration. The laminate and infrared shielding structure were cut into 5cm x 5cm pieces and measured. In this measurement, the aluminum oxide secondary white plate attached to the device was used as a reference, and the device was placed behind the integrating sphere with the substrate layer side as the incident surface. Measurement was performed under the following conditions, and the maximum reflectance in the wavelength range of 800nm ​​to 1000nm was calculated. <Measurement conditions> Slit: 2nm (visible) / Automatic control (infrared) Gain: 2 Scanning speed: 600 nm / min Starting wavelength: 2600nm End wavelength: 240nm Sampling interval: 1 nm Incident angle: 10°.

[0154] (12) Heat insulation The total energy transmittance (Tts) of the samples was measured in accordance with ISO 13837:2008 "Road vehicles - Safety glazing materials - Measurement method for solar transmittance" and evaluated on the following six-point scale, with C or higher being considered good. <Incidence plane> Infrared shielding structure: substrate side Glass laminate: Glass side SS: The total energy transmittance (Tts) of the sample was 45% or less. S: The total energy transmittance (Tts) of the sample was greater than 45% and less than or equal to 50%. A: The total energy transmittance (Tts) of the sample was greater than 50% and less than 60%. B: The total energy transmittance (Tts) of the sample was greater than 60% and less than or equal to 70%. C: The total energy transmittance (Tts) of the sample was greater than 70% and less than or equal to 80%. D: The total energy transmittance (Tts) of the sample was greater than 80%.

[0155] (13) Thermal insulation To evaluate the heat insulation, the heat transmission coefficient of the sample was measured in accordance with JIS-R3107:2019 and rated on the following five-point scale, with B or above being considered good. S: The sample's heat transfer coefficient is 5.2 W / m 2 It was less than K. A: The sample's heat transfer coefficient is 5.2 W / m 2 K or more 5.6W / m 2 It was less than K. B: The sample has a thermal conductivity of 5.6 W / m 2 K or more 5.9W / m 2 It was less than K. C: The sample had a heat transmission coefficient of 5.9 or more.

[0156] (14) Transparency Measurements were taken under the following conditions using a Hitachi, Ltd. spectrophotometer (U-4100 Spectrophotometer) with the standard configuration (solid measurement system) to determine the average transmittance in the wavelength range of 400 nm to 700 nm, which was taken as the visible light transmittance. Transparency was evaluated based on the visible light transmittance using a two-level rating system according to the following criteria, with A being a pass. A: Visible light transmittance was 70% or more. B: Visible light transmittance was less than 70%. <Measurement conditions> Slit: 2nm (visible) / Automatic control (infrared) Gain: 2 Scanning speed: 600 nm / min Starting wavelength: 700nm End wavelength: 400nm Sampling interval: 1 nm Incident angle: 0°.

[0157] (15) Color The b-value of the transmittance of the sample was measured and calculated according to JIS Z8701:1999. Light source C was selected as the light source. Color was evaluated on a four-point scale based on the b-value according to the following criteria, with D or above being considered a pass. A: The b value was between -2.0 and 2.0. B: The b value was -4.0 or more and less than -2.0, or greater than 2.0 and less than 4.0. C: The b value was -5.0 or more and less than -4.0, or greater than 4.0 and less than 5.0. D: The b value was greater than -6.0 and less than -5.0, or greater than 5.0 and less than 6.0. The E:b value was less than -6.0 or greater than 6.0.

[0158] (16)Durability For the glass bonded body produced in (10), first, in the initial state, the b value of transmission was measured and calculated in the same manner as in (15) Color, and designated as b0. Then, the same glass bonded body was treated for 200 hours under the conditions shown below using "Eye Super UV Tester" (registered trademark) SUV-W151 manufactured by Iwasaki Electric Co., Ltd., and the b value of the glass bonded body after the treatment was measured and calculated in the same manner, and designated as b a Next, b a The value obtained by subtracting b0 (the b value in the initial state) from the b value after treatment was taken as Δb. Durability was evaluated using Δb in two stages according to the following criteria. A: Δb was less than 3. B: Δb was 3 or more. <Measurement conditions> Temperature:50% Humidity: 60%RH Illuminance: 100mW / cm 2 Irradiation surface: Glass side.

[0159] (17) In-plane average refractive index of layer A of multilayer film The refractive index was measured at a laser wavelength of 633 nm using a Prism Coupler SPA-400 manufactured by Cylon Technology Co., Ltd. The refractive index was measured in the direction of the main orientation axis in the plane of the multilayer film and in the direction perpendicular to the main orientation axis, and the average value was taken as the in-plane average refractive index.

[0160] (18) In-plane average refractive index of layer B of multilayer film Because Layer B is an internal layer of the multilayer film, the refractive index was measured not on the multilayer film itself, but on a film of Layer B resin alone produced under the same stretching and heat treatment conditions as the multilayer film, using a Prism Coupler SPA-400 manufactured by Cylon Technology Co., Ltd. with a measurement laser wavelength of 633 nm. The refractive index was measured in the direction of the main orientation axis in the film plane of Layer B resin alone, and in the direction perpendicular to the main orientation axis, and the average of these measurements was taken as the in-plane average refractive index.

[0161] [Resin used in multilayer film] Resin 1: A crystalline polyethylene terephthalate resin exhibiting a glass transition temperature of 78°C, a melting point of 254°C, a crystallization temperature of 180°C, and a melting enthalpy of 40 J / g. Resin 2: Amorphous polyethylene terephthalate resin blend obtained by blending Resin 1 with polyethylene terephthalate resin copolymerized with 29 mol% spiroglycol and 21 mol% cyclohexanedicarboxylic acid, which has a glass transition temperature of 80°C, in a ratio of 70:30 (mass ratio). Resin 3: A crystalline polyethylene naphthalate resin exhibiting a glass transition temperature of 124°C, a melting point of 262°C, a crystallization temperature of 200°C, and a melting enthalpy of 48 J / g. Resin 4: Amorphous polyethylene terephthalate resin copolymerized with 33 mol% cyclohexanedimethanol, exhibiting a glass transition temperature of 80°C.

[0162] Example 1 [Coating liquid containing acrylic resin] An aqueous dispersion (so-called emulsion coating liquid) in which acrylic resin having the copolymer composition below is dispersed in water in the form of particles. ·Copolymerization component Methyl methacrylate 63% by mass Ethyl acrylate 35% by mass Acrylic acid 1% by mass N-methylolacrylamide 1% by weight.

[0163] [Coating liquid containing polyester resin] An ammonium salt-type aqueous dispersion in which polyester resin having the following copolymer composition is dispersed in water in the form of particles. ·Acid component Terephthalic acid 28 mol% Isophthalic acid 9 mol% Trimellitic acid 10 mol% Sebacic acid 3 mol% Glycol ingredients Ethylene glycol 15 mol% Neopentyl glycol 18 mol% 1,4-butanediol 17 mol %.

[0164] [Coating liquid containing infrared absorbing particles 1] A 50 mL plastic container was charged with 0.3 g of PGFE1 as an aqueous dispersant and 11.7 g of ion-exchanged water. Then, 3 g of indium tin oxide powder (E-ITO, primary particle size 50 nm, manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.) and 30 g of zirconia beads (φ1 mm) were added. This mixture was dispersed at 600 rpm for 15 hours using a rocking mill (RM-05, manufactured by Seiwa Giken Co., Ltd.). The zirconia beads were then removed by filtration to obtain an indium tin oxide dispersion. The resulting indium tin oxide dispersion was mixed with polyester resin in a 50 / 50 mass ratio and dispersed by rotating the mixture at a peripheral speed of 10 m / s for 5 hours using a homomixer to obtain an indium tin oxide dispersion modified with polyester resin. The resulting dispersion was then diluted with ion-exchanged water to a concentration of indium tin oxide of 25% by mass, resulting in coating solution 1 containing infrared-absorbing particles 1.

[0165] [Resin composition] The obtained coating liquid containing acrylic resin, coating liquid containing polyester resin, and coating liquid containing infrared absorbing particles 1 were mixed so that the solid mass ratio was acrylic resin / polyester resin / infrared absorbing particles 1 = 7.5 / 17.5 / 75, and the concentration was adjusted with a mixed solvent of isopropyl alcohol and water (20 / 80 (mass ratio)) so that the total solid content was 30 mass%. Furthermore, in order to improve the coatability onto the polyester film for the base layer, a fluorine-based surfactant ("PLASCOAT" (registered trademark) RY-2 manufactured by GOO Chemical Co., Ltd.) was added in an amount of 0.03 mass% relative to 100 mass% of the total resin composition to obtain a resin composition (listed as coating agent 1 in Table 1).

[0166] [Laminate] Resin 1 was used as the thermoplastic resin. Resin A was melted at 280 ° C in an extruder, and after removing foreign matter through five FSS-type leaf disc filters, it was fed into a T-die and formed into a sheet. After that, an electrostatic voltage of 8 kV was applied with a wire, and the sheet was rapidly cooled and solidified on a casting drum maintained at a surface temperature of 25 ° C to obtain an unstretched film. This unstretched film was longitudinally stretched by the difference in peripheral speed of the rolls at a temperature of 90 ° C and a magnification of 3.5 times, and then cooled to obtain a uniaxially stretched film. Subsequently, one side of this uniaxially stretched film was subjected to a corona discharge treatment in air, and the resin composition, coating agent 1, was applied to the treated surface using a bar coater to a coating thickness of approximately 6 μm. The uniaxially stretched film was then guided into a tenter while holding both widthwise ends with clips, and stretched laterally at a temperature of 110°C and a stretching ratio of 4.3 times. It was then heat-treated at 220°C for 20 seconds, and further relaxed in the widthwise direction by 1.6% to obtain an 80 μm thick laminate in which resin layer 1 was laminated on a substrate layer.

[0167] [Coating liquid containing infrared shielding particles 2] DPHA (dipentaerythritol hexaacrylate), potassium tert-butoxide, and a photoinitiator (BASF Japan "IRGACURE" (registered trademark) 184) were mixed in a mass ratio of 99:1:1, and the solid content was adjusted to a concentration of 40% with MEK (methyl ethyl ketone) (Coating A). Coating A and cesium tungsten oxide particles (Cs) 0.33A slurry with a WO3 solid content concentration of 20 mass % was mixed at a mass ratio of solids of 80:18.5 to prepare a coating liquid (coating agent B) containing infrared shielding particles 2.

[0168] [Infrared shielding structure] The surface of the resin layer 1 of the laminate obtained above was coated with the coating agent B using a wire bar coater, and then dried in a hot air oven at 80°C for 2 minutes. Thereafter, ultraviolet rays of 300 mJ / cm were applied using a UV irradiation device. 2 The coating was irradiated and cured to form a resin layer 2, thereby obtaining an infrared shielding structure. The amount of coating was adjusted so that the thickness of the resin layer 2 would be 3 μm. The evaluation results of the obtained infrared shielding structure are shown in Table 1.

[0169] Example 2 An infrared shielding structure was produced under the same conditions as in Example 1, except that the infrared absorbing particles 1 in the resin composition were changed to antimony-doped tin oxide powder to form coating material 2. The evaluation results of the obtained infrared shielding structure are shown in Table 1.

[0170] Example 3 An infrared shielding structure was produced under the same conditions as in Example 1, except that the resin composition was changed to Coating Agent 3 described below. The evaluation results of the obtained infrared shielding structure are shown in Table 1.

[0171] [Resin composition] A coating liquid containing a polyester resin and a coating liquid 1 containing infrared-absorbing particles 1 were mixed so that the solids mass ratio was polyester resin / infrared-absorbing particles 1 = 25 / 75, and the concentration was adjusted with a mixed solvent of isopropyl alcohol and water (20 / 80 (mass ratio)) so that the total solids content was 30 mass%. Furthermore, to improve the coatability onto the polyester film for the base layer, a fluorine-based surfactant ("PLASCOAT" (registered trademark) RY-2 manufactured by GOO Chemical Co., Ltd.) was added in an amount of 0.03 mass% relative to 100 mass% of the total resin composition, to obtain a resin composition (shown as Coating Agent 3 in Table 1).

[0172] Example 4 An infrared shielding structure was produced under the same conditions as in Example 1, except that the laminate was produced using the off-coating method as follows. The evaluation results of the obtained infrared shielding structure are shown in Table 1.

[0173] [Infrared shielding structure] Resin 1 was used as the thermoplastic resin. Resin A was melted at 280 ° C in an extruder, and after removing foreign matter through five FSS-type leaf disc filters, it was fed into a T-die and formed into a sheet. An electrostatic voltage of 8 kV was applied with a wire, and the sheet was rapidly cooled and solidified on a casting drum maintained at a surface temperature of 25 ° C to obtain an unstretched film. This unstretched film was longitudinally stretched at a temperature of 90 ° C and a stretching ratio of 3.5 times by the difference in peripheral speed of the rolls, and then cooled to obtain a uniaxially stretched film. Next, this uniaxially stretched film was clamped at both widthwise ends with clips and introduced into a tenter, where it was transversely stretched at a temperature of 110 ° C and a stretching ratio of 4.3 times, then heat-treated at 220 ° C for 20 seconds, and further relaxed in the widthwise direction by 1.6% to obtain a substrate layer with a thickness of 80 μm. The resin composition was then applied to the obtained substrate layer using a bar coater to a coating thickness of approximately 1.4 μm, and then the layer was placed in a drying oven and dried at a temperature of 110°C, after which it was heat-treated at 220°C for 20 seconds to obtain a laminate.

[0174] Example 5 An infrared shielding structure was produced under the same conditions as in Example 4, except that the infrared absorbing particles 1 in the resin composition were changed to cesium tungsten oxide powder to produce coating agent 4, and the coating liquid containing the infrared shielding particles 2 was changed to coating agent C described below. The evaluation results of the obtained infrared shielding structure are shown in Table 1. Coating agent C: Coating agent A and a slurry containing indium tin oxide powder with a solid content concentration of 20 mass % were mixed at a solid content mass ratio of 80:18.5.

[0175] Example 6 An infrared shielding structure was produced under the same conditions as in Example 5, except that the coating liquid containing the infrared shielding particles 2 was changed to Coating Agent D described below. The evaluation results of the obtained infrared shielding structure are shown in Table 1. Coating agent D: Coating agent A and a slurry of antimony-doped tin oxide powder with a solids concentration of 20 mass % were mixed at a solids mass ratio of 80:18.5.

[0176] Example 7 An infrared shielding structure was produced under the same conditions as in Example 5, except that the resin composition was changed to Coating Agent 5 described below. The evaluation results of the obtained infrared shielding structure are shown in Table 1. Coating agent 5: Coating agent 5 was prepared by preparing a resin composition in the same manner as coating agent 3, except that the infrared absorbing particles 1 were changed to cesium tungsten oxide powder.

[0177] Example 8 An infrared shielding structure was produced under the same conditions as in Example 1, except that the resin composition was applied so that the thickness of resin layer 1 was about 15 μm to obtain a laminate, and the thickness of resin layer 2 was adjusted to 1.0 μm. The evaluation results of the obtained infrared shielding structure are shown in Table 1.

[0178] Example 9 An infrared shielding structure was produced under the same conditions as in Example 1, except that the temperature of the heat treatment when forming the resin layer 1 was changed to 150° C. Table 1 shows the evaluation results of the obtained infrared shielding structure.

[0179] Example 10 An infrared shielding structure was produced under the same conditions as in Example 4, except that the temperature of the heat treatment when forming the resin layer 1 was changed to 150° C. Table 1 shows the evaluation results of the obtained infrared shielding structure.

[0180] Example 11 An infrared shielding structure was produced under the same conditions as in Example 1, except that the heat treatment temperature during formation of the resin layer 1 was changed to 110°C. The evaluation results of the obtained infrared shielding structure are shown in Table 1. Note that the heat treatment temperature of 110°C is the same as the temperature during transverse stretching, and therefore this indicates that the heat treatment was essentially carried out in one stage.

[0181] Example 12 Except for changing the laminate as follows, an infrared shielding structure was produced under the same conditions as in Example 1. Table 1 shows the evaluation results of the obtained infrared shielding structure.

[0182] [Laminate] Resin 1 was used as the crystalline thermoplastic resin (hereinafter also referred to as Resin A) constituting Layer A, and Resin 2 was used as the thermoplastic resin (hereinafter also referred to as Resin B) constituting Layer B. Resins A and B were melted at 280°C in separate extruders and then passed through five FSS-type leaf disc filters to remove any impurities. The two resins were then merged in a 201-layer feed block while being metered using a gear pump to achieve a resin A / resin B ratio of 1 / 1.07. A total of 201 layers of resins A and B were laminated alternately in the thickness direction, with resin A forming the outermost layer on both sides. The layer thicknesses of layers A and B were designed to provide a flat reflectance spectrum in the wavelength range from 380 nm to 780 nm. The resulting molten laminate was then fed into a T-die to be formed into a sheet. It was then quenched and solidified on a casting drum maintained at a surface temperature of 25°C while an electrostatic voltage of 8 kV was applied using a wire, yielding an unstretched film. This unstretched film was longitudinally stretched by differential roll speed at a temperature of 90°C and a stretching ratio of 3.5x, then cooled to obtain a uniaxially stretched film. Subsequently, one side of this uniaxially stretched film was subjected to a corona discharge treatment in air, and the treated surface was coated with Coating Agent 1, a resin composition, using a bar coater to a coating thickness of approximately 6 μm. The uniaxially stretched film was then guided into a tenter, gripped at both widthwise ends with clips, and transversely stretched at a temperature of 110°C and a stretching ratio of 4.3x. It was then heat-treated at 220°C for 20 seconds and further relaxed in the width direction by 1.6% to obtain an 80 μm-thick laminate. The resulting laminate reflected infrared light in the wavelength range of 800 to 1000 nm, while possessing a flat reflectance distribution with almost no reflection in the visible light range of 400 to 700 nm. In addition, the average in-plane refractive index of layer A of the obtained laminate was 1.66, and the average in-plane refractive index of layer B was 1.55, and the difference in the average in-plane refractive index was 0.11.

[0183] Example 13 An infrared shielding structure was produced under the same conditions as in Example 11, except that resin 3 was used as resin A and resin 4 was used as resin B, and the number of laminated layers was changed to 401. The evaluation results of the obtained infrared shielding structure are shown in Table 1. The number of laminated layers was adjusted by the number of layers (number of slits) in the feed block. The in-plane average refractive index of layer A of the obtained laminate was 1.75, and the in-plane average refractive index of layer B was 1.56, resulting in a difference in the in-plane average refractive index of 0.19.

[0184] Example 14 An infrared shielding structure was produced under the same conditions as in Example 1, except that the resin composition was applied so that the thickness of the resin layer 1 was about 1.5 μm. The evaluation results of the obtained infrared shielding structure are shown in Table 1.

[0185] Example 15 Except for adjusting the thickness of the resin layer 2 to 5.0 μm, an infrared shielding structure was produced under the same conditions as in Example 1. Table 1 shows the evaluation results of the obtained infrared shielding structure.

[0186] (Comparative Example 1) An infrared shielding structure was produced under the same conditions as in Example 1, except that the resin composition was changed to Coating Agent 6 described below. The evaluation results of the obtained infrared shielding structure are shown in Table 1.

[0187] [Resin composition] A coating liquid containing an acrylic resin and a coating liquid containing a polyester resin were mixed so that the solid mass ratio was acrylic resin / polyester resin = 30 / 70, and the concentration was adjusted with a mixed solvent of isopropyl alcohol and water (20 / 80 (mass ratio)) so that the total solid content was 30 mass%. Furthermore, to improve the coatability onto the polyester film for the base layer, a fluorine-based surfactant ("PLASCOAT" (registered trademark) RY-2 manufactured by GOO Chemical Co., Ltd.) was added in an amount of 0.03 mass% relative to 100 mass% of the total resin composition to obtain a resin composition (listed as Coating Agent 6 in Table 1).

[0188] (Comparative Example 2) An infrared shielding structure was produced under the same conditions as in Comparative Example 1, except that the coating liquid containing the infrared shielding particles 2 was changed to Coating Agent E described below. The evaluation results of the obtained infrared shielding structure are shown in Table 1. Coating E: Coating A and cesium tungsten oxide particles Cs 0.33 A slurry with a solid content concentration of WO3 of 20 mass % and a slurry with a solid content concentration of indium tin oxide powder of 20 mass % were mixed in a solid content mass ratio of 80:18:18.

[0189] (Comparative Example 3) An infrared shielding structure was produced under the same conditions as in Example 1, except that the coating material for forming the resin layer 2 was changed to Coating material A. Table 1 shows the evaluation results of the obtained infrared shielding structure.

[0190] Comparative Example 4 An infrared shielding structure was produced under the same conditions as in Comparative Example 3, except that the resin composition was changed to Coating Agent 7 described below. The evaluation results of the obtained infrared shielding structure are shown in Table 1.

[0191] [Coating liquid containing infrared absorbing particles 1] A 50 mL plastic container was charged with 0.3 g of PGFE1 as an aqueous dispersant and 11.7 g of ion-exchanged water. Then, 3 g of indium tin oxide powder (E-ITO, primary particle size 50 nm, manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.) and 30 g of zirconia beads (φ1 mm) were added. This mixture was dispersed at 600 rpm for 15 hours using a rocking mill (RM-05, manufactured by Seiwa Giken Co., Ltd.), and the zirconia beads were removed by filtration to obtain an indium tin oxide dispersion. The resulting indium tin oxide dispersion was mixed with polyester resin in a 50 / 50 mass ratio and dispersed by rotating the mixture at a peripheral speed of 10 m / s using a homomixer for 5 hours to obtain an indium tin oxide dispersion modified with polyester resin. The resulting dispersion was then diluted with ion-exchanged water to a concentration of indium tin oxide of 25% by mass, resulting in coating solution 2 containing infrared-absorbing particles 1. Furthermore, cesium tungsten oxide (Cs) was prepared by the same procedure as above, except that the indium tin oxide powder was replaced with cesium tungsten oxide powder. 0.33The coating liquid was diluted with ion-exchanged water to a WO3 concentration of 25 mass %, to obtain coating liquid 3 containing infrared absorbing particles 1. The obtained coating liquids 2 and 3 were mixed in a volume ratio of 1:1 to obtain coating liquid 4 containing infrared absorbing particles 1 with a total concentration of the indium tin oxide dispersion and the cesium tungsten oxide dispersion of 25 mass %.

[0192] [Resin composition] The obtained acrylic resin-containing coating liquid, polyester resin-containing coating liquid, and coating liquid 4 were mixed so that the solid mass ratio was acrylic resin / polyester resin / infrared absorbing particle 1 = 7.5 / 17.5 / 75, and the concentration was adjusted with a mixed solvent of isopropyl alcohol and water (20 / 80 (mass ratio)) so that the total solid content was 30 mass%. Furthermore, to improve the coatability onto polyester film, a fluorine-based surfactant (Goo Chemical Co., Ltd. "Pluscoat" (registered trademark) RY-2) was added in an amount of 0.03 mass% relative to 100 mass% of the total resin composition to obtain a resin composition (listed as coating agent 7 in Table 1).

[0193] [Table 1]

[0194] (Examples 16 to 18) Using the same infrared shielding structure as in Example 1, a glass bonded body was produced so as to have the configuration shown in Table 2. Table 2 shows the evaluation results of the obtained glass bonded body.

[0195] (Examples 19 to 21) Using the same infrared shielding structure as in Example 12, a glass bonded structure was produced so as to have the configuration shown in Table 2. Table 2 shows the evaluation results of the obtained glass bonded structure.

[0196] (Comparative Examples 5 to 7) Using the same infrared shielding structure as in Comparative Example 1, a glass bonded body was produced so as to have the structure shown in Table 2. Table 2 shows the evaluation results of the obtained glass bonded body.

[0197] [Table 2]

[0198] Examples 22 to 34 The laminates obtained in Examples 1 to 5 and 7 to 14 were designated, respectively, as Examples 22 to 34. Table 3 shows the evaluation results.

[0199] (Reference examples 1 and 2) The laminates obtained in Comparative Examples 1 and 4 were designated as Reference Examples 1 and 2, respectively. Table 3 shows the evaluation results.

[0200] [Table 3]

[0201] Examples 35 to 44 Laminates were produced in the same manner as in Example 1 (an example of in-line coating) and Example 4 (an example of off-coating), except that the type of resin layer 1, the layer structure of the substrate layer, the production method, and the thickness of the resin layer 1 were as shown in Table 4. The evaluation results of the obtained laminates are shown in Table 4.

[0202] [Coating 8] A resin composition was prepared in the same manner as in Coating 3, except that the infrared absorbing particles 1 were changed to antimony-doped tin oxide powder.

[0203] [Table 4]

[0204] (Examples 45 to 55) An infrared shielding structure was obtained in the same manner as in Example 1 (an example of in-line coating) and Example 4 (an example of off-coating), except that the type and thickness of resin layer 2, the type of resin layer 1, the layer structure of the base layer, the production method, and the thickness of resin layer 1 were as shown in Table 5. The evaluation results of the obtained infrared shielding structure are shown in Table 5.

[0205] [Painting material F] Coating agent A and a slurry containing lanthanum hexaboride particles LaB6 with a solid content of 20% by mass were mixed in a solids mass ratio of 80:18.5.

[0206] [Table 5] [Industrial Applicability]

[0207] According to the present invention, it is possible to provide an infrared shielding structure that has excellent heat ray shielding performance due to its combination of heat shielding and heat insulating properties, and also has a design that suppresses blue tinge. Because the infrared shielding structure of the present invention has the above-mentioned excellent properties, it can be suitably used for windows of buildings, automobiles, etc. [Explanation of symbols]

[0208] 1 Resin layer 2 2 Resin layer 1 3 Base material layer 4. From the base layer side to the resin layer 2 side, at a position of 20% of the thickness 5. From the base layer side to the resin layer 2 side, at the 90% thickness position 6 Resin layer 1 7 Base material layer 8 In the resin layer 1, from the base material layer side to the opposite side, at a position of 20% of the thickness 9 In the resin layer 1, from the base material layer side to the opposite side, at the position of 90% of the thickness

Claims

1. A substrate layer, a resin layer 1, and a resin layer 2 are provided in this order, an infrared absorbing structure, characterized in that the resin layer 1 contains infrared absorbing particles 1, the resin layer 2 contains infrared absorbing particles 2, one of the infrared absorbing particles 1 and the infrared absorbing particles 2 contains tin element, and the other contains tungsten element.

2. In the resin layer 1, the detection sensitivity of the infrared absorbing particles 1 at a position of 20% of the thickness from the base layer side toward the resin layer 2 side is defined as X ２０ , the detection sensitivity of the infrared absorbing particle 1 at the position of 90% of the thickness is X ９０ When this is done, X ２０ ≧2×X ９０ The infrared shielding structure according to claim 1 , wherein

3. 3. The infrared shielding structure according to claim 1, wherein the first infrared absorbing particle contains elemental tin, and the second infrared absorbing particle contains elemental tungsten.

4. 3. The infrared shielding structure according to claim 1, wherein when the thickness of said resin layer 1 is D1 and the thickness of said resin layer 2 is D2, D1<D2 is satisfied.

5. 3. The infrared shielding structure according to claim 1, wherein the resin layer 1 contains an acrylic resin and a polyester resin, and the ratio of the acrylic resin increases and the ratio of the polyester resin decreases from the base material layer side to the resin layer 2 side.

6. 3. The infrared shielding structure according to claim 1, wherein the maximum value of reflectance at wavelengths of 800 to 1000 nm measured from the substrate layer side is 50% or more and 110% or less.

7. 3. The infrared shielding structure according to claim 1, wherein the substrate layer has an adhesive layer on a surface opposite to the resin layer, the adhesive layer containing a UV absorber.

8. A window comprising a glass, the adhesive layer, and the infrared shielding structure according to claim 1 in this order, wherein the base material layer is located closer to the glass than the resin layer.

9. A resin layer 1 is provided on at least one surface of a base material layer, and the resin layer 1 contains infrared absorbing particles 1. In the resin layer 1, the detection sensitivity of the infrared absorbing particles 1 at a position 20% of the thickness from the base material layer side to the opposite side is defined as X ２０ , the detection sensitivity of the infrared absorbing particle 1 at the position of 90% of the thickness is X ９０ When this is done, X ２０ ≧2×X ９０ A laminate characterized by satisfying the above.

10. The laminate according to claim 9 , wherein the resin layer 1 contains an acrylic resin and a polyester resin, and the ratio of the acrylic resin increases and the ratio of the polyester resin decreases from the base layer side to the opposite side.

11. The laminate according to claim 9 or 10, wherein the infrared absorbing particles 1 contain tin element.

12. The laminate according to claim 9 or 10, wherein the maximum value of reflectance at a wavelength of 800 to 1000 nm measured from the substrate layer side is 50% or more and 110% or less.

13. The laminate according to claim 9 or 10, further comprising a resin layer 2 on a surface of the resin layer 1 opposite to the base layer, the resin layer 2 containing infrared absorbing particles 2 different from the infrared absorbing particles 1.

14. The laminate according to claim 13, wherein the infrared absorbing particles 2 contain elemental tungsten.

15. The laminate according to claim 9 or 10, wherein the substrate layer has an adhesive layer on a surface opposite to the resin layer 1, the adhesive layer containing a UV absorber.

16. A window comprising the laminate according to claim 15 and a glass on the surface of the adhesive layer opposite to the substrate layer.

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