Interlayer structure for laminated panels, and laminated panel structure

Abstract

An interlayer film structure (11) is used sandwiched between two transparent panels (12), (13), and comprises: a first light modulation film (21) that can switch between transmitting light and scattering light; and a second light modulation film (22) that can adjust visible light transmittance, wherein the first and second light modulation films (21), (22) are arranged in the thickness direction.

Description

Technical Field

[0001] The present invention relates to an intermediate film structure for a laminated panel used by being sandwiched between two transparent panels, and a laminated panel structure including the intermediate film structure for a laminated panel.

Background Art

[0002] In autonomous vehicles and EVs, in terms of functionality, active functionalization has become a trend in automotive components, regardless of the interior and exterior of the vehicle. As one of the active functionalizations, conventionally, a windshield equipped with an electrically controllable visor has been studied. For example, as described in Patent Document 1, it has been studied to apply a dimming film such as a polymer-dispersed liquid crystal (PDLC) film to the visor. When no voltage is applied, the liquid crystal in the PDLC film is randomly oriented, resulting in strong light scattering. When a voltage is applied, the liquid crystal aligns and has high light transmittance. Therefore, by arranging it at the upper part of the windshield, it can be used as an alternative to a mechanical visor.

[0003] Conventionally, light-transmitting members such as windows having a dimming film have been variously improved. For example, in Patent Document 2, a dimming device provided with two dimming layers having a liquid crystal layer is disclosed from the viewpoint of further enhancing the light-shielding property. Further, as the dimming film, in addition to those having a liquid crystal such as PDLC, an SPD (Suspended Particle Device) film provided with a dimming layer in which a light-adjusting suspension is dispersed in a resin matrix, as shown in Patent Document 3, is also known.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

[0005] Incidentally, in the design of autonomous vehicles and electric vehicles, there is growing interest in full-glass top designs, where the roof is covered in glass, and seamless designs, where the joint between the glass and the body is eliminated. Roof designs, in particular, are attracting attention. However, in a full-glass top design structure, where the glass area of ​​the roof is large, it is difficult to implement in practice because there is no space to install mechanical shades such as window opening and closing units. Therefore, in large-area roof structures, there is a risk of more sunlight and heat rays entering from above. While the introduction of dark-tinted laminated glass to block external light is being considered, using dark-tinted laminated glass makes it difficult to obtain the benefit of roof glass, such as the sense of openness it provides, and thus does not adequately meet the needs of users.

[0006] Therefore, the application of dimmable films such as PDLC as an alternative to mechanical shades is being considered for roof glass. However, PDLC does not adequately control the amount of heat entering the vehicle, and when combined with clear or light-colored glass or laminated glass, it is not possible to sufficiently enhance heat shielding. On the other hand, heat shielding can be ensured by combining PDLC with dark-colored glass or dark-colored laminated glass, but as mentioned above, sufficient openness cannot be obtained, or sufficient light transmission cannot be obtained even when the PDLC is in light transmission mode.

[0007] Therefore, the object of the present invention is to provide an interlayer film structure for laminated panels that provides sufficient openness while appropriately preventing the inflow of heat rays, and also provides sufficient light transmission in light transmission mode. [Means for solving the problem]

[0008] As a result of diligent research, the inventors have found that the above problems can be solved by using a combination of two or more specific types of dimming films, and have completed the present invention as described below. The present invention provides the following [1] to

[35] . [1] An interlayer structure for laminated panels, which is used sandwiched between two transparent panels, comprising a first dimmable film capable of switching between light transmission and light scattering, and a second dimmable film capable of adjusting the visible light transmittance, wherein the first and second dimmable films are arranged in the thickness direction. [2] The interlayer film structure for a laminated panel according to [1] above, wherein the second dimming film is positioned on the outdoor side of the first dimming film. [3] The interlayer film structure for a laminated panel according to [1] or [2] above, comprising an internal transparent adhesive layer disposed between the first light-adjusting film and the second light-adjusting film to bond the light-adjusting films together. [4] The interlayer film structure for a laminated panel according to [3], wherein the first and second dimming films are heat-pressed together via the internal transparent adhesive layer. [5] The interlayer structure for laminated panels according to any one of the above [1] to [4], comprising a transparent surface adhesive layer on the outermost surface of the interlayer structure for laminated panels. [6] A laminated panel structure obtained by bonding two 2.5 mm thick clear glass sheets via the laminated panel interlayer structure, wherein the visible light transmittance measured with the first light-adjusting film as the light transmission mode can be adjusted by the second light-adjusting film to 1% or less and 10% or more, as described in any one of the above [1] to [5]. [7] A laminated panel structure obtained by bonding two 2.5 mm thick clear glass sheets via the laminated panel interlayer structure, wherein the Tds (Solar direct transmittance) measured with the first light-adjusting film as the light transmission mode can be adjusted to 55% or less, as described in any one of the above [1] to [6]. [8] A laminated panel structure obtained by bonding two 2.5 mm thick clear glass sheets via the laminated panel interlayer structure, wherein the haze value measured with the first dimming film as the light transmission mode can be adjusted to 40% or less, as described in any one of the above [1] to [7]. [9] The first and second dimming films are interlayer film structures for laminated panels according to any one of the above [1] to [8], wherein the respective peripheral edges are positioned at least 10 mm inward from the peripheral edge of the transparent panel.

[10] The interlayer film structure for a laminated panel according to [9] above, comprising a sealing material provided on the outer periphery of the first and second dimming films.

[11] The interlayer structure for a laminated panel according to any one of the above [1] to

[10] , further comprising a touch sensor inside the interlayer structure for the laminated panel for controlling at least one of the first and second dimming films.

[12] The interlayer film structure for a laminated panel according to any one of the above [1] to

[11] , wherein the first dimming film is divided into a plurality of independently controllable segments.

[13] The interlayer film structure for a laminated panel according to any one of the above [1] to

[12] , wherein the first dimming film is either a polymer dispersed liquid crystal film or a polymer network liquid crystal.

[14] The interlayer film structure for a composite panel according to any one of the above [1] to

[13] , wherein the second light-adjusting film is an electrochromic film, an SPD film, and an electrophoretic film device.

[15] The first dimming film is an interlayer film structure for a laminated panel according to any one of the above [1] to

[14] , wherein in the light transmission mode, the visible light transmittance is 60% or more and 100% or less, and the haze value is 0% or more and 30% or less.

[16] The first dimming film is an interlayer film structure for a laminated panel according to any one of the above [1] to

[15] , wherein the visible light transmittance in the light scattering mode is 0% or more and 40% or less, and the haze value is 70% or more and 100% or less.

[17] The interlayer film for a laminated panel according to any one of the above [1] to

[16] , wherein the second dimming film is switchable between a light transmission mode and a light shielding mode, and in the light transmission mode, the visible light transmittance is 25% or more and 100% or less, and the haze value is 0% or more and 30% or less.

[18] The second dimming film is switchable between a light transmission mode and a light shielding mode, and in the light shielding mode, the visible light transmittance is less than 25% and the haze value is less than 60%, as described in any one of the above [1] to

[17] , as an interlayer film structure for a laminated panel.

[19] The interlayer structure for a laminated panel according to any one of the above [3] to

[18] , wherein the internal transparent adhesive layer is a thermoplastic resin layer.

[20] The interlayer film structure for a laminated panel according to

[19] above, wherein the thermoplastic resin in the internal transparent adhesive layer is one or more selected from the group consisting of ethylene vinyl acetate copolymer, polyurethane thermoplastic elastomer, polyolefin resin, cyclic olefin resin, and polyvinyl acetal resin.

[21] The interlayer structure for a laminated panel according to any one of the above [5] to

[20] , wherein the surface transparent adhesive layer is a thermoplastic resin layer.

[22] The interlayer film structure for a laminated panel according to

[21] , wherein the thermoplastic resin in the surface transparent adhesive layer is one or more selected from the group consisting of ethylene vinyl acetate copolymer, polyurethane thermoplastic elastomer, polyolefin resin, cyclic olefin resin, and polyvinyl acetal resin.

[23] An interlayer structure for a laminated panel according to any one of the above [5] to

[22] , comprising, in order, the surface transparent adhesive layer, the first light-adjusting film, the internal transparent adhesive layer, the second light-adjusting film, and the surface transparent adhesive layer.

[24] The interlayer film structure for a laminated panel according to any one of the above

[10] to

[23] , wherein the sealing material is made of a thermoplastic resin.

[25] The interlayer film structure for a laminated panel according to

[24] , wherein the thermoplastic resin in the sealing material is one or more selected from the group consisting of ethylene vinyl acetate copolymer, polyurethane thermoplastic elastomer, polyolefin resin, cyclic olefin resin, and polyvinyl acetal resin.

[26] A laminated panel structure obtained by bonding two 2.5 mm thick clear glass sheets via the laminated panel interlayer structure, wherein the haze value measured with the first dimming film in light scattering mode is 70% or more, and the visible light transmittance is 20% or less, as described in any one of the above [1] to

[25] .

[27] A laminated panel structure obtained by bonding two 2.5 mm thick clear glass sheets via the laminated panel interlayer structure, wherein the Tds measured with the first light-adjusting film in light scattering mode is less than 10% as described in any one of the above [1] to

[26] .

[28] The interlayer film structure for a laminated panel according to any one of the above [1] to

[27] , wherein the first dimming film comprises two base films and a dimming layer disposed between the two base films.

[29] The interlayer film structure for a laminated panel according to any one of the above [1] to

[28] , wherein the second light-adjusting film comprises two base films and a light-adjusting layer disposed between the two base films.

[30] comprising an interlayer structure for a laminated panel as described in any one of the above items [1] to

[29] , and two transparent panels, A laminated panel structure in which the aforementioned interlayer structure for laminated panels is sandwiched between the two transparent panels.

[31] The composite panel structure described in

[30] above, wherein the thickness is 7 mm or less.

[32] The laminated panel structure described in

[30] or

[31] above, which is for use with automobile roof glass.

[33] The composite panel structure described in

[30] or

[31] above, which is for use in buildings.

[34] Use of the intermediate film structure for a laminated panel according to any one of [1] to

[29] above, or the laminated panel structure according to

[30] or

[31] above, in an automotive roof glass.

[35] Use of the intermediate film structure for a laminated panel according to any one of [1] to

[29] above, or the laminated panel structure according to

[30] or

[31] above, in a building.

Effect of the Invention

[0009] In the present invention, while appropriately preventing the inflow of heat rays, a sufficient sense of openness can be obtained, and in the light transmission mode, sufficient light transmittance can be obtained.

Brief Description of the Drawings

[0010] [Figure 1] It is a schematic cross-sectional view showing a laminated panel structure according to an embodiment of the present invention. [Figure 2] It is a schematic cross-sectional view showing a laminated panel structure according to an embodiment of the present invention. [Figure 3] It is an exploded perspective view showing the laminated panel structure shown in FIG. 2. [Figure 4] It is a schematic cross-sectional view showing a laminated panel structure according to an embodiment of the present invention. [Figure 5] It is a schematic cross-sectional view showing a laminated panel structure according to an embodiment of the present invention. [Figure 6] It is a schematic cross-sectional view showing a laminated panel structure according to an embodiment of the present invention. [Figure 7] It is a schematic cross-sectional view showing a laminated panel structure according to an embodiment of the present invention. [Figure 8] It is a schematic cross-sectional view showing a laminated panel structure according to an embodiment of the present invention.

Mode for Carrying Out the Invention

[0011] <Intermediate Film Structure for Panel> The interlayer structure for laminated panels of the present invention (hereinafter also referred to as the "interlayer structure") is used sandwiched between two transparent panels and comprises first and second light-adjusting films arranged in the thickness direction. In the present invention, the first light-adjusting film is a light-adjusting film that can switch between light transmission and light scattering, and the second light-adjusting film is a light-adjusting film that can adjust the visible light transmittance. The interlayer structure of the present invention can effectively prevent the inflow of heat rays by appropriately combining the modes of the first and second dimming films to block light. Furthermore, even when the first dimming film is in a light-transmitting mode, the second dimming film can be used to adjust the transmittance of visible light according to the external conditions, making it possible to increase light transmittance or suppress light transmittance while achieving a sense of openness. Thus, a composite panel structure that fully meets the needs of the user can be provided.

[0012] [First dimmable film] The first dimmable film is a dimmable element capable of switching between light transmission and light scattering. In light transmission mode, the first dimmable film has a high visible light transmittance. In light scattering mode, it has a high haze value, and the visible light transmittance is lower compared to light transmission mode. Switching between light transmission mode and light scattering mode of the first dimmable film is performed by applying or not applying voltage.

[0013] It is preferable to use a polymer-dispersed liquid crystal (PDLC) film as the first dimming film. Using a PDLC film makes it easier to increase the visible light transmittance in light transmission mode and to obtain high light scattering in light scattering mode, making it easier to increase the haze value in light scattering mode. Polymer network liquid crystal (PNLC) can also be used as the first dimming film.

[0014] The first light-adjusting film comprises, for example, two base films and a light-adjusting layer disposed between the two base films. Examples of base films include resin films using polyester resins such as polyethylene terephthalate and polyethylene naphthalate, acrylic resins, cellulose derivatives such as triacetyl cellulose (TAC), polyethersulfone (PES) resin, and polyimide resin as resin components. Among these, polyester resin films are preferred from the viewpoint of handling and other factors, and polyethylene terephthalate films are more preferred.

[0015] Furthermore, an electrode layer is preferably provided on the side of each of the two base films that faces the light-adjusting layer. The electrode layer can be any conventionally known transparent electrode material without particular limitations, such as indium tin oxide (ITO) conductive film, tin oxide conductive film, zinc oxide conductive film, or polymer conductive film. A lead electrode is preferably connected to the electrode layer, and a voltage is applied between the electrode layers via the lead electrode.

[0016] In the first dimmable film, the dimmable layer is, for example, a liquid crystal layer. If the first dimmable film is a polymer-dispersed liquid crystal (PDLC) film, the liquid crystal layer is composed of polymer-dispersed liquid crystal (PDLC). A polymer-dispersed liquid crystal is a type called a network liquid crystal, in which a network structure is formed by polymers within the liquid crystal layer. The liquid crystal layer may be formed by creating a space for filling the liquid crystal inside using, for example, a spacer, and then filling and sealing that space with liquid crystal, although the spacer is not required. Furthermore, any type of liquid crystal can be used, such as a TN type or an STN type. Additionally, an alignment film may be provided between the dimming layer and the electrode layer as appropriate. By providing an alignment film, the first dimming film can also be a reverse type, as described later.

[0017] The first dimmable film changes the orientation of the liquid crystal layer when a voltage is applied between the electrode layers, switching between light transmission and light scattering. The first dimmable film can be either a normal type or a reverse type. The normal type is a type that transmits light when a voltage is applied (voltage ON) and scatters light when no voltage is applied (voltage OFF). The reverse type is a type that transmits light when no voltage is applied and scatters light when a voltage is applied.

[0018] As described above, the first dimmable film has a high visible light transmittance and a low haze value in light transmission mode. The specific visible light transmittance of the first dimmable film in light transmission mode is, for example, 60% or more, preferably 70% or more, and more preferably 75% or more. Having such a visible light transmittance allows the light transmittance of the laminated panel structure to be sufficiently high in light transmission mode, and when used, for example, on the roof glass of an automobile, a sufficient sense of openness can be obtained. Furthermore, the haze value of the first dimming film in light transmission mode is, for example, 30% or less, preferably 20% or less, and more preferably 10% or less. In addition, the visible light transmittance of the first dimming film in light transmission mode should be 100% or less, but in practice it should be 99% or less, and the haze value should be 0% or more, but in practice it should be, for example, 1% or more.

[0019] On the other hand, in the light scattering mode, the haze value of the first dimming film is, for example, 70% or more, preferably 80% or more, and more preferably 90% or more. When the haze value is this high in the light scattering mode, the light-shielding ability is enhanced, and the inflow of heat rays can be appropriately prevented in the light scattering mode. In addition, it is possible to prevent people from looking into the inside from the outside of the laminated panel structure. Furthermore, in the light scattering mode, the visible light transmittance of the first dimming film is lower than in the light transmission mode, for example, 40% or less, preferably 20% or less, and more preferably 10% or less. As described above, when the light transmittance is low in the light scattering mode, the inflow of heat rays can be appropriately prevented in the light scattering mode. Furthermore, the haze value of the first dimming film in the light scattering mode should be 100% or less, but in practice it is around 99% or less. Also, the visible light transmittance should be 0% or more, but in practice it is, for example, around 1% or more.

[0020] Furthermore, when no voltage is applied, the first dimmable film should be in either the light scattering mode or the light transmission mode, and in that mode, the haze value and visible light transmittance should be within the range described above. Also, when voltage is applied, the first dimmable film should be in the other mode, and in that mode, the haze value and visible light transmittance should be within the range described above. However, the applied voltage value is not limited; the haze value and visible light transmittance should be within the range described above at any voltage value. The same applies to the light transmission mode and light shielding mode of the second dimmable film, which will be described later.

[0021] The thickness of the first dimming film is not particularly limited, but is, for example, 0.05 mm or more and 2 mm or less, preferably 0.1 mm or more and 1 mm or less, and more preferably 0.2 mm or more and 0.8 mm or less. The first dimming film can be a commercially available product. Specifically, examples include the normal type [light transmission mode: haze value 5%, parallel line transmittance 82%, light scattering mode: haze value 98%, parallel line transmittance 1% (catalog value)] and the reverse type [light transmission mode: haze value 10%, parallel line transmittance 80%, light scattering mode: haze value 92%, parallel line transmittance 7% (catalog value)] from Toppan Printing Co., Ltd. Furthermore, examples include the window type of "UMU" from Nippon Sheet Glass UMU Products Co., Ltd. [light transmission mode: haze value 6%, parallel line transmittance 74%, light scattering mode: haze value 86%, parallel line transmittance 5% (catalog value)]. In addition, examples include "LC-W" from Gauzy.

[0022] [Second dimmable film] The second dimmable film is a dimmable element capable of adjusting visible light transmittance. The second dimmable film should ideally be switchable between a light transmission mode with high visible light transmittance and a light shielding mode with low visible light transmittance. The second dimmable film does not produce much light scattering even in light-shielding mode, so the haze value does not become very high, and the haze value is lower than that of the first dimmable film in the light-scattering mode described above.

[0023] Examples of the second type of light-adjusting film include electrochromic films, SPD films, and electrophoretic film devices, with SPD films being preferred among these. Using these films reduces visible light transmittance without causing significant light scattering. Therefore, by using the first light-adjusting film in light-transmitting mode and the second light-adjusting film in light-blocking mode, it is possible to suppress light transmission while minimizing light scattering and preventing complete shading. When used in window glass, this allows for a certain degree of heat transmission prevention while still providing a sense of openness.

[0024] The second light-adjusting film comprises, for example, two base films and a light-adjusting layer placed between the two base films. Examples of base films include resin films, and the resin used in the resin film is as described for the first light-adjusting film, but from the viewpoint of handling and other factors, polyester resin films are preferred, and among them, polyethylene terephthalate films are more preferred. Therefore, it is preferable that the base films of both the first and second light-adjusting films are polyester resin films, and it is even more preferable that they are both polyethylene terephthalate films.

[0025] Furthermore, in the second light-adjusting film, an electrode layer is preferably provided on the light-adjusting layer side of each of the two base films. Any conventionally known transparent electrode material can be used as the electrode layer, such as indium tin oxide (ITO) conductive film, tin oxide conductive film, zinc oxide conductive film, and polymer conductive film. A lead electrode is preferably connected to the electrode layer, and a voltage is preferably applied between the electrode layers via the lead electrode.

[0026] <<SPDフィルム> > If the light-adjusting film is an SPD (Suspended Particle Device) film, the light-adjusting layer is a layer comprising a resin matrix and a light-adjusting suspension dispersed within the resin matrix. The resin matrix consists of a polymer medium, and the photo-modified suspension is a dispersion medium in which photo-modified particles are dispersed in a fluid state. The polymer medium and dispersion medium (dispersion medium in the photo-modified suspension) should be such that the polymer medium and its cured product and the dispersion medium can separate from each other at least when they form a film. It is preferable to use a combination of a polymer medium and a dispersion medium that are incompatible or partially compatible with each other.

[0027] The polymer medium includes a resin having substituents with ethylenically unsaturated bonds and a photopolymerization initiator, and is cured by irradiation with energy rays such as ultraviolet light, visible light, or electron beams. Preferred resins having ethylenically unsaturated bonds include silicone resins, acrylic resins, and polyester resins. In addition to the resins having substituents with ethylenically unsaturated bonds as described above, organic solvent-soluble resins or thermoplastic resins, such as polyacrylic acid and polymethacrylic acid, can also be used as constituent materials for the polymer medium. Furthermore, additives such as color inhibitors like dibutyltin dilaurate may be added to the polymer medium as needed. In addition, the polymer medium may contain a solvent.

[0028] As the dispersion medium in the photo-conditioned suspension, it is preferable to use a liquid copolymer that acts as a dispersion medium in the photo-conditioned suspension, selectively adheres to and coats the photo-conditioned particles, acts to cause the photo-conditioned particles to move to the droplet phase after phase separation from the polymer medium, has no electrical conductivity, and has no affinity for the polymer medium. As the liquid copolymer, for example, (meth)acrylic acid ester oligomers having fluoro groups and / or hydroxyl groups are preferred, and (meth)acrylic acid ester oligomers having fluoro groups and hydroxyl groups are more preferred. The photo-modified suspension used in the present invention is a suspension in which photo-modified particles are fluidly dispersed in a dispersion medium. As the photo-modified particles, for example, polyiodide crystals are used, and needle-shaped polyiodide microcrystals are preferably used. When a voltage is applied between the two electrode layers of an SPD film, the light-tuning particles orient themselves in the thickness direction, which is desirable to increase the light transmittance, for example, the transmittance in a specific wavelength range. Furthermore, in the SPD film, a primer layer may be appropriately provided between the light-adjusting layer and the electrode layer.

[0029] When no voltage is applied between the electrode layers of an SPD film (voltage OFF), it exhibits low light transmittance and enters a light-shielding mode. Conversely, by applying a voltage between the electrode layers (voltage ON), the transmittance in a specific wavelength range increases, thereby switching from the light-shielding mode to the light-transmitting mode. The SPD film may also change its color tone when irradiated with visible light, along with the change in visible light transmittance. For example, it can be colorless and transparent when voltage is applied, while having a blue or other color tone when no voltage is applied. Furthermore, changing the magnitude of the voltage applied between the electrodes of the SPD film also changes the magnitude of the visible light transmittance in the light-transmitting mode.

[0030] <<Electrochromic film>> If the second light-adjusting film is an electrochromic film, the light-adjusting layer may contain an electrochromic material. The electrochromic material is not limited to any compound that has electrochromic properties, and may be an inorganic compound, an organic compound, or a mixed-valence complex. Examples of inorganic compounds include Mo2O3, Ir2O3, NiO, V2O5, WO3, and TiO2, with WO3 being preferred. Examples of organic compounds include polypyrrole compounds, polythiophene compounds, poly(p-phenylene)vinylene compounds, polyaniline compounds, polyacetylene compounds, polyethylenedioxythiophene compounds, metal phthalocyanine compounds, viologen compounds, viologen salt compounds, ferrocene compounds, dimethyl terephthalate compounds, and diethyl terephthalate compounds, with polyacetylene compounds being preferred. Examples of mixed-valence complexes include Prussian blue type complexes (such as KFe[Fe(CN)6]).

[0031] Electrochromic films change their transmittance in a specific wavelength range, for example, when a voltage is applied between the electrode layers. This causes the photochromic material to change from a state of high visible light transmittance (light transmission mode) to a state of low visible light transmittance (light shielding mode). In addition, the color tone may also change when irradiated with visible light. For example, it is possible to make the film colorless and transparent when no voltage is applied, while exhibiting colors such as blue, yellow, green, or red when a voltage is applied.

[0032] <<Electrophoretic Film Devices>> An electrophoretic film device, for example, has an electrophoretic section between two electrode layers on a substrate. The electrophoretic section comprises, for example, electrophoretic particles and a dispersant for dispersing the electrophoretic particles. In an electrophoretic film device, it is possible to switch between a state with high visible light transmittance (light transmission mode) and a state with low visible light transmittance (light shielding mode) by changing whether or not a voltage is applied between the electrode layers. Specific examples of electrophoretic film devices are described in detail in U.S. Patent Publication No. 2016 / 0124284, among others.

[0033] The second dimmable film has a visible light transmittance above a certain value and a low haze value in the light transmission mode. The specific visible light transmittance of the second dimmable film in the light transmission mode is, for example, 25% or more, preferably 30% or more, and more preferably 40% or more. By having such a visible light transmittance, both the first and second dimmable films are set to the light transmission mode, which increases the light transmittance of the laminated panel structure. For example, when used in car windows, especially roof windows, it is possible to obtain a sufficient sense of openness and observe the outside with high visibility. Furthermore, the haze value of the second dimming film in light transmission mode is, for example, 30% or less, preferably 20% or less, and more preferably 10% or less. The visible light transmittance of the second dimming film in light transmission mode may be 100% or less, but practically it may be 70% or less, and the haze value may be 0% or more, but practically it may be 1% or more.

[0034] On the other hand, in the light-shielding mode, the haze value of the second dimming film is, for example, less than 60%, preferably less than 50%, and more preferably less than 40%. In the light-shielding mode, being able to lower the haze value in this way ensures that the directivity of transmitted light is maintained while maintaining high light-shielding performance. Therefore, by setting the first dimming film to the light-transmitting mode and the second dimming film to the light-shielding mode, it is possible to ensure a certain sense of openness while appropriately preventing the inflow of heat rays. On the other hand, the haze value of the second dimming film in the light-shielding mode is not particularly limited, but is generally higher than the haze value of the second dimming film in the light-transmitting mode.

[0035] Furthermore, in light-shielding mode, the visible light transmittance of the second dimming film is lower than in light-transmitting mode, for example, less than 25%, preferably 20% or less, and more preferably 10% or less. As described above, when the light transmittance is low in light-shielding mode, the inflow of heat rays can be appropriately prevented in light-shielding mode. Furthermore, in the light-shielding mode, the visible light transmittance of the second dimming film is preferably 5% or less, from the viewpoint of ensuring a sense of openness to the outside while avoiding the glare of sunlight during the day, by setting the second dimming film to light-shielding mode and the first dimming film to light-transmitting mode. Furthermore, the visible light transmittance of the second dimming film in the light shielding mode is not particularly limited, but may be, for example, 0.5% or more, or 1% or more.

[0036] The thickness of the second dimming film is not particularly limited, but is, for example, 0.05 mm or more and 2 mm or less, preferably 0.1 mm or more and 1 mm or less, and more preferably 0.2 mm or more and 0.8 mm or less.

[0037] Commercially available products can be used as the second type of dimming film. Specifically, examples of SPD films include Hitachi Chemical Co., Ltd.'s "LCF-1103DHA" Light type [light transmission mode: visible light transmittance 45-65% (50-100V), haze value 6%, light shielding mode: visible light transmittance 3% (catalog value)], and Dark type [light transmission mode: visible light transmittance 30-53% (50-100V), haze value 6%, light shielding mode: visible light transmittance 1% (catalog value)]. Furthermore, Gauzy's "SPD" is an example of an SPD film. Other examples include Ynvisible's electrochromic films and Signify's "E-Skin" as an electrophoresis film device.

[0038] The laminated panel structure of the present invention can be used, for example, in various types of window glass, as described later, and is preferably used as a component to separate the indoors from the outdoors. It is preferable that the second light-adjusting film is positioned on the outdoor side of the first light-adjusting film. When the second light-adjusting film is positioned on the outdoor side, external light such as sunlight entering the room from the outdoors is blocked by the second light-adjusting film, reducing the amount of light that irradiates the PDLC film and other components that make up the first light-adjusting film. As a result, the durability of the first light-adjusting film, such as a PDLC film with low light resistance, is improved, and the durability of the entire interlayer structure is also improved.

[0039] [switch] The interlayer structure may include a switch member. The switch member is a member for controlling the first and second dimming films. The switch member may control whether or not to apply a voltage between the electrode layers of the first dimming film via a switch input. This allows the switch member to switch between the light transmission mode and the light scattering mode of the first dimming film.

[0040] Furthermore, the switch member may control whether or not a voltage is applied between the electrode layers of the second dimming film. This allows the switch member to switch between the light transmission mode and the light shielding mode of the second dimming film. The switch member for controlling the second dimming film may be the same as, or different from, the switch member for controlling the first dimming film. Furthermore, it is preferable that the switch member can also change the voltage value applied between the electrode layers of the second dimming film. In such a configuration, for example, when an SPD film is used as the second dimming film, the magnitude of the visible light transmittance in the light transmission mode can be adjusted by changing the magnitude of the voltage value applied between the electrodes using the switch member. The switch component may be located outside the interlayer structure, but it is preferable that it be composed of a touch sensor located inside the interlayer structure. Therefore, it is preferable that at least one of the first and second dimming films is controlled by a touch sensor. Details of the touch sensor will be described later.

[0041] [Internal transparent adhesive layer] The interlayer structure of the present invention comprises a first light-adjusting film and a transparent adhesive layer (hereinafter also referred to as an internal transparent adhesive layer) disposed between the first and second light-adjusting films, and it is preferable that the first and second light-adjusting films are bonded via the internal transparent adhesive layer. That is, it is preferable that the interlayer structure comprises the first light-adjusting film, the internal transparent adhesive layer, and the second light-adjusting film in this order.

[0042] If an internal transparent adhesive layer is provided, the base film of the first light-adjusting film and the base film of the second light-adjusting film should be bonded together via the internal transparent adhesive layer. The base film of the light-adjusting film has a relatively high melting point, making it difficult to directly bond the first and second light-adjusting films by methods such as thermocompression. However, by using an internal transparent adhesive layer, they can be easily integrated and incorporated into the multilayer structure of the interlayer. Furthermore, from the viewpoint of ease of manufacturing, it is preferable that the first and second light-adjusting films are bonded by thermocompression via the internal transparent adhesive layer. Furthermore, the internal transparent adhesive layer is transparent and has a high visible light transmittance. Therefore, the presence of the internal transparent adhesive layer does not impair the optical properties of the interlayer structure, such as light transmittance.

[0043] The first and second dimming films are preferably heat-pressed together via an internal transparent adhesive layer at a temperature of 100°C or lower to form a single unit, and more preferably heat-pressed together via an internal transparent adhesive layer at a temperature of 100°C or lower to form a single unit before joining the two transparent panels together via an interlayer structure to form a single panel structure. The first and second light-adjusting films can be heat-pressed together under conditions of 100°C or less, thereby integrating them without thermal degradation of the light-adjusting layer. Furthermore, by heat-pressing while reducing pressure, integration can be achieved with even fewer air pockets between the layers. The heat-pressing temperature is, for example, 30°C to 120°C, but preferably 40°C to 100°C.

[0044] The internal transparent adhesive layer is preferably a thermoplastic resin layer. When the internal transparent adhesive layer is a thermoplastic resin layer, the first and second light-adjusting films can be easily bonded to each other via the internal transparent adhesive layer by the heat-pressure bonding process. The thermoplastic resin used in the internal transparent adhesive layer is not particularly limited, but examples include polyolefin resins (PO) such as ethylene vinyl acetate copolymer (EVA), polyurethane thermoplastic elastomer (TPU), polyethylene resin, and polypropylene resin, cyclic olefin resins (COP) such as cyclic olefin copolymer (COC), and polyvinyl acetal resins (PVAc) such as polyvinyl butyral resin (PVB). By using these resins, the first and second light-adjusting films can be bonded even at relatively low temperatures during heat bonding, and furthermore, the adhesion of the light-adjusting film to the base film tends to be good. Among these, polyvinyl acetal resin is preferred, and polyvinyl butyral resin is more preferred. Using polyvinyl acetal resin tends to result in good adhesion to the light-adjusting film, and also improves the penetration resistance of the laminated panel structure.

[0045] In the internal transparent adhesive layer, the thermoplastic resin is often the main component, and its content is often 50% by mass or more, preferably 70% by mass or more, and more preferably 80% by mass or more, based on the total amount of the internal transparent adhesive layer.

[0046] Furthermore, the internal transparent adhesive layer may contain a plasticizer. When the internal transparent adhesive layer contains a plasticizer, it becomes more flexible, thereby improving the flexibility of the laminated panel structure and making it easier to improve puncture resistance. It also improves adhesion to each dimming film. Examples of plasticizers include organic ester plasticizers such as monobasic organic acid esters and polybasic organic acid esters. Furthermore, the internal transparent adhesive layer may contain additives other than plasticizers, such as fillers, infrared absorbers, ultraviolet absorbers, antioxidants, light stabilizers, fluorescent whitening agents, crystal nucleating agents, dispersants, dyes, pigments, metal carboxylate salts, and heat-shielding materials, as needed.

[0047] The thickness of the internal transparent adhesive layer is preferably 0.05 mm to 1.5 mm, more preferably 0.1 mm to 1.0 mm, and even more preferably 0.2 mm to 0.5 mm, from the viewpoint of ensuring good adhesion while preventing the interlayer structure from becoming unnecessarily thick.

[0048] [Surface transparent adhesive layer] Preferably, a transparent adhesive layer (hereinafter also referred to as the "surface transparent adhesive layer") is provided on the outermost surface of the interlayer structure. The interlayer structure can be easily adhered to the transparent panel by having a surface transparent adhesive layer. Preferably, the surface transparent adhesive layer is provided on the outermost surfaces of both interlayer structures. In this specification, the surface transparent adhesive layer located on the outside of the first light-adjusting film is referred to as the first surface transparent adhesive layer, and the surface transparent adhesive layer located on the outside of the second light-adjusting film is referred to as the second surface transparent adhesive layer. Therefore, it is preferable that the interlayer structure has a laminate comprising a first surface transparent adhesive layer, a first light-adjusting film, a transparent adhesive layer, a second light-adjusting film, and a second surface transparent adhesive layer in this order.

[0049] As described above, the first dimming film is difficult to directly adhere to the transparent panel by methods such as heat bonding. However, by having the first transparent surface adhesive layer, the interlayer structure can be easily integrated with the transparent panel by heat bonding or other methods. Furthermore, the first and second transparent surface adhesive layers are transparent and have high visible light transmittance. Therefore, the first and second transparent surface adhesive layers do not impair various optical properties of the interlayer structure, such as light transmittance.

[0050] The surface transparent adhesive layer is preferably a thermoplastic resin layer. Furthermore, if the interlayer structure has a first and a second surface transparent adhesive layer, it is more preferable that both of these are thermoplastic resin layers. When the surface transparent adhesive layer is a thermoplastic resin layer, the interlayer structure can be easily bonded to the transparent panel by thermocompression bonding.

[0051] The thermoplastic resin used in the surface transparent adhesive layer (i.e., the first or second surface transparent adhesive layer, or both) is not particularly limited, but any of the resins listed as usable for the transparent adhesive layer can be appropriately selected and used. By using the above resin, the interlayer structure can be bonded to the transparent panel even with relatively low-temperature thermocompression bonding. This prevents thermal damage to the light-adjusting film. Furthermore, the thermoplastic resin used in the surface transparent adhesive layer is preferably a polyvinyl acetal resin, and among these, polyvinyl butyral resin is more preferable. By using a polyvinyl acetal resin, adhesion to transparent panels, especially transparent panels made of inorganic glass, tends to be improved. In addition, the puncture resistance of the laminated panel structure is also improved. Therefore, when the laminated panel structure has an internal transparent adhesive layer and first and second surface transparent adhesive layers, the thermoplastic resins used in the internal transparent adhesive layer and the first and second surface transparent adhesive layers are preferably polyvinyl acetal resins, and among these, polyvinyl butyral resins are more preferably used. In each transparent surface adhesive layer, the thermoplastic resin is often the main component, and its content is often 50% by mass or more, preferably 70% by mass or more, and more preferably 80% by mass or more, based on the total amount of each transparent surface adhesive layer.

[0052] The surface transparent adhesive layer (i.e., the first or second surface transparent adhesive layer, or both) may contain a coloring agent and be a colored layer. When a colored layer is used, it is preferable that both the first and second surface transparent adhesive layers be colored layers. By making the surface transparent adhesive layer a colored layer, the visible light transmittance of the interlayer structure can be adjusted as appropriate. Therefore, the degree of openness and the amount of heat radiation incident can be adjusted as appropriate according to the user's needs. Furthermore, the color of the interlayer structure and the laminated panel structure can be adjusted as appropriate.

[0053] The colorants used are not particularly limited, and dyes conventionally incorporated into interlayers for laminated glass can be used, including blue, yellow, red, green, purple, black, and white. The dyes can be pigments, dyes, etc. Furthermore, from the viewpoint of heat shielding and design, black pigments and black dyes are preferred as colorants, with carbon black being more preferred among them. When the transparent adhesive layer on the surface is to be used as a colored layer, any known transparent colored film can be used as appropriate. As a transparent colored film, for example, one with a visible light transmittance of, for example, 70% or more, preferably 75-90%, should be used. Commercially available transparent colored films can be used, for example, the colored films of the "S-LEC Film" series manufactured by Sekisui Chemical Co., Ltd.

[0054] Furthermore, each transparent surface adhesive layer may contain a plasticizer. When a transparent surface adhesive layer contains a plasticizer, it becomes more flexible, which in turn improves the flexibility of the composite panel structure and makes it easier to improve puncture resistance. It also makes it easier to improve adhesion to the dimming film and the transparent panel. Examples of plasticizers include organic ester plasticizers such as monobasic organic acid esters and polybasic organic acid esters. Furthermore, each transparent adhesive layer on the surface may contain additives other than plasticizers and colorants, such as fillers, infrared absorbers, ultraviolet absorbers, antioxidants, light stabilizers, fluorescent whitening agents, crystal nucleating agents, dispersants, metal carboxylate salts, and heat-shielding materials, as needed.

[0055] From the viewpoint of ensuring good adhesion while preventing the interlayer structure from becoming unnecessarily thick, the thickness of each surface transparent adhesive layer is preferably 0.05 mm to 1.5 mm, more preferably 0.1 mm to 1.0 mm, and even more preferably 0.2 mm to 0.5 mm.

[0056] <Combined panel structure> The laminated panel structure of the present invention comprises the above-described laminated panel interlayer structure and two transparent panels, wherein the laminated panel interlayer structure is sandwiched between the two transparent panels. In the laminated panel structure, the two transparent panels are bonded together via the above-described laminated panel interlayer structure.

[0057] Examples of transparent panels include glass plates. The glass plate may be either inorganic glass or organic glass, but inorganic glass is preferred. Examples of inorganic glass are not particularly limited, but include clear glass, clear float glass, float plate glass, tempered glass, colored glass, polished plate glass, patterned glass, wired plate glass, reinforced plate glass, ultraviolet absorbing plate glass, infrared reflective plate glass, infrared absorbing plate glass, green glass, etc. Furthermore, as organic glass, what is generally called resin glass is used, and in particular limited Although not explicitly mentioned, examples of organic glass include those composed of polycarbonate sheets, polymethyl methacrylate sheets, and polyester sheets. The two transparent panels may be made of the same material or different materials. For example, one may be inorganic glass and the other organic glass, but it is preferable that both transparent panels be inorganic glass or organic glass, and more preferably that both be inorganic glass.

[0058] The thickness of each of the transparent panels is not particularly limited, but is preferably 0.5 mm to 3.2 mm, more preferably 0.7 mm to 2.7 mm, and even more preferably 1.0 mm to 2.6 mm. By keeping the thickness within this range, it is possible to impart a certain level of mechanical strength to the laminated panel structure while keeping the overall thickness of the laminated panel structure below a certain level.

[0059] The laminated panel structure of the present invention preferably has a thickness of 7 mm or less. A thickness of 7 mm or less makes it suitable for use in automotive window glass, particularly automotive roof glass. Furthermore, while the thickness of the laminated panel structure is not particularly limited to a lower limit, it is, for example, 4 mm or more, preferably 5 mm or more.

[0060] [Layer composition] Next, the laminated structure of the interlayer structure and the laminated panel structure comprising the interlayer structure will be described in more detail with reference to the drawings. Figures 1 to 8 show laminated panel structures having an interlayer structure according to each embodiment of the present invention. As shown in Figure 1, the laminated panel structure 10 comprises an interlayer structure 11 and two transparent panels 12 and 13. The interlayer structure 11 is sandwiched between the two transparent panels 12 and 13, and the two transparent panels 12 and 13 are bonded together via the interlayer structure 11. Furthermore, in a preferred embodiment of the present invention, the interlayer structure 11 comprises, as shown in Figure 1, a first surface transparent adhesive layer 31, a first light-adjusting film 21, an internal transparent adhesive layer 30, a second light-adjusting film 22, and a second surface transparent adhesive layer 32 in that order. The first surface transparent adhesive layer 31 and the second surface transparent adhesive layer 32 are then bonded to the respective transparent panels 12 and 13.

[0061] Here, as described above, it is preferable that the second dimming film 22 be positioned on the outdoor side of the first dimming film 21. That is, it is preferable that the transparent panel 13 be positioned on the outdoor side and the transparent panel 12 be positioned on the indoor side. The same applies to each embodiment described below. However, the first dimming film 21 may be positioned on the outdoor side of the second dimming film 22.

[0062] In the interlayer structure 11 shown in Figure 1, the peripheral edges 21A and 22A of each dimming film 21 and 22 are positioned to coincide with the peripheral edges 12A and 13A of the two transparent panels 12 and 13 when viewed in plan in the thickness direction; however, they do not necessarily need to be positioned to coincide. Specifically, as shown in the embodiments in Figures 2 and 3, the peripheral edges 21A and 22A of the dimming films 21 and 22 may be positioned on the inner circumference side of the peripheral edges 12A and 13A of the transparent panels 12 and 13. In this case, it is preferable that the peripheral edges 21A and 22A of the dimming films 21 and 22 are positioned on the inner circumference side at a distance L of 10 mm or more from the peripheral edges 12A and 13A of the two panels 12 and 13.

[0063] While a portion of each peripheral edge 21A, 22A may be positioned on the inner circumference side of both peripheral edges 12A, 13A, it is preferable that each peripheral edge 21A, 22B be positioned on the inner circumference side of both peripheral edges 12A, 13A over its entire circumference, and more preferably that it be positioned on the inner circumference side of both peripheral edges 12A, 13A at a distance L of 10 mm or more over its entire circumference.

[0064] Furthermore, the distance L between each peripheral edge 21A, 22A and peripheral edges 12A, 13A is 10 mm or more, as described above, and there is no particular upper limit, but for example it should be 150 mm or less. The peripheral edges 12A and 13A of the transparent panels 12 and 13 are usually positioned to coincide with each other when viewed from above in the thickness direction, but they may be misaligned. Similarly, the peripheral edges 21A and 22B of the dimming films 21 and 22 are usually positioned to coincide with each other when viewed from above in the thickness direction, but they may be misaligned. Therefore, if they are misaligned, the distance L should be the distance between the closest peripheral edges of the transparent panel and the dimming film, but it is more preferable that the distance L is within the above range around the entire circumference.

[0065] Furthermore, as shown in Figures 2 and 3, when the peripheral edges 21A and 22A of the dimming films 21 and 22 are positioned on the inner side of the peripheral edges 12A and 13A of the transparent panels 12 and 13, it is preferable that the interlayer structure 10 includes a sealing material 35 positioned on the outer periphery of the first and second dimming films 21 and 22. When the peripheral edges 21A and 22A of the dimming films 21 and 22 are positioned on the inner side, a gap is created on the outer periphery of the dimming films 21 and 22 by the amount they are positioned on the inner side, but this gap can be filled by placing the sealing material 35.

[0066] The sealing material 35 may be placed on the outer periphery of the light-adjusting films 21 and 22, but as shown in Figure 3, it is preferable to place it on the outer periphery around the entire circumference of the light-adjusting films 21 and 22. Therefore, as shown in Figure 3, it is preferable that the sealing material 35 be formed in a frame shape when viewed in plan in the thickness direction. The sealing material 35 will then be placed between the transparent panels 21 and 22. The width of the frame-shaped sealing material 35 should be the same as the distance L.

[0067] Furthermore, in the embodiment shown in Figure 2, the interlayer structure 11 is preferably positioned so that not only the peripheral edges 21A and 22A of the light-adjusting films 21 and 22, but also the peripheral edges 30A, 31A and 32A of the transparent adhesive layers 30, 31 and 32 are located on the inner circumference side of the peripheral edges 12A and 13A of the transparent panels 12 and 13. With the interlayer structure 11 having such a structure, the sealing material 35 is positioned not only on the light-adjusting films 21 and 22, but also on the outer circumference side of the adhesive layers 30, 31 and 32. The thickness of the sealing material 35 is the same as the thickness of the interlayer structure 11, and the sealing material 35 only needs to be bonded to the transparent panels 12 and 13 on both sides in the thickness direction. As a result, the sealing material 35 in the embodiment shown in Figure 3 can more easily ensure high sealing performance.

[0068] Furthermore, the sealing material 35 is preferably bonded to the peripheral edges 30A, 31A, and 32A of each transparent adhesive layer 30, 31, and 32, forming a single unit. By bonding the sealing material 35 to each adhesive layer 30, 31, and 32, the first and second light-adjusting films 21 and 22 become a sealed structure formed by the adhesive layers 30, 31, and 32 and the sealing material 35. As a result, the first and second light-adjusting films 21 and 22 are protected from the intrusion of water, oxygen, etc. from the outside, and their durability is enhanced. In addition, the sealing material 35 is preferably bonded to the peripheral edges 21A and 22A of the light-adjusting films 21 and 22 as appropriate.

[0069] However, as shown in Figure 4, the sealing material 35 may be arranged only on the outside of the light-adjusting films 21 and 22, and the peripheral edges 30A, 31A, and 32A of each transparent adhesive layer 30, 31, and 32 may be arranged outside the peripheral edges 21A and 21B of the light-adjusting films 21 and 22. In this case, two sealing materials 35 are provided on the outside of each light-adjusting film 21 and 22 as the first and second sealing materials 35A and 35B. In the outer peripheral region of the light-adjusting films 21 and 22, there is a laminated structure consisting of the first surface transparent adhesive layer 31, the first sealing material 35A, the internal transparent adhesive layer 30, the second sealing material 35B, and the second surface transparent adhesive layer 32.

[0070] Furthermore, as shown in Figure 5, the sealing material 35 may be positioned on the outer periphery of the light-adjusting films 21, 22 and the internal transparent adhesive layer 30 between them, and the peripheral edges 31A, 32A of the surface transparent adhesive layers 31, 32 may be positioned further outward than the peripheral edges 21A, 21B of the light-adjusting films 21, 22. With this configuration, the outer periphery of the light-adjusting films 21, 22 will have a laminated structure consisting of the first surface transparent adhesive layer 31, the sealing material 35, and the second surface transparent adhesive layer 32. The sealing material 35 may have the same thickness as the total thickness of the light-adjusting films 21, 22 and the transparent adhesive layer 30, and both sides of the sealing material 35 in the thickness direction may be bonded to the surface transparent adhesive layers 31, 32.

[0071] Furthermore, when a sealing material 35 is provided as in the embodiments shown in Figures 2, 4, and 5, the lead electrodes (not shown) of each dimming film 21 and 22 may extend to the outside through the space between the sealing material 35 and the transparent panel 21 or transparent panel 22 in the configuration of Figure 2, and may extend to the outside through the space between the sealing material 35 and the adhesive layer in the configurations of Figures 4 and 5.

[0072] (Sealing material) The sealing material is preferably made of a resin, and more preferably a thermoplastic resin. When the sealing material is made of a thermoplastic resin, it is easier to adhere to the transparent panel or other transparent adhesive layers by thermocompression bonding. The thermoplastic resin used in the encapsulant can be appropriately selected from the list of thermoplastic resins that can be used in the transparent adhesive layer. By using the above resins, the encapsulant can be bonded to the transparent panel or other transparent adhesive layer even at relatively low temperatures during heat bonding, and damage to the light-adjusting film during heat bonding can be prevented. Furthermore, polyvinyl acetal resins are preferred as the thermoplastic resin used in the encapsulant, and polyvinyl butyral resins are more preferred among them. Using polyvinyl acetal resins results in excellent adhesion to transparent panels, especially transparent panels made of inorganic glass. It also provides excellent adhesion to the transparent adhesive layer, light-adjusting film, etc.

[0073] From the viewpoint of adhesion with other transparent adhesive layers, it is preferable to use the same type of resin for the sealing material as for the transparent adhesive layer provided on the interlayer structure. Therefore, when the interlayer structure comprises a encapsulant, first and second surface transparent adhesive layers, and an internal transparent adhesive layer, the thermoplastic resins used in the encapsulant, the first and second surface transparent adhesive layers, and the internal transparent adhesive layer are all preferably polyvinyl acetal resins, and more preferably polyvinyl butyral resins. In the sealing material, the thermoplastic resin is often the main component, and its content is often 50% by mass or more, preferably 70% by mass or more, and more preferably 80% by mass or more, based on the total amount of the sealing material.

[0074] Furthermore, the encapsulant may contain a plasticizer. When a plasticizer is included in the encapsulant, it becomes more flexible, and its adhesion to transparent panels and other transparent adhesive layers is also improved. Examples of plasticizers include organic ester plasticizers such as monobasic organic acid esters and polybasic organic acid esters. Furthermore, the encapsulant may contain additives other than plasticizers, such as fillers, infrared absorbers, ultraviolet absorbers, antioxidants, light stabilizers, fluorescent whitening agents, crystal nucleating agents, dispersants, dyes, pigments, metal carboxylate salts, and heat-shielding materials, as needed.

[0075] Furthermore, as shown in the embodiment of Figure 6, it is also preferable that a touch sensor 37 is provided inside the interlayer structure 11. The touch sensor 37 may be placed, for example, in a space 37A provided inside the interlayer structure 11. As shown in Figure 6, space 37A may be provided, for example, by making a notch in a part of the first dimming film 21, and a touch sensor 37 in the notched portion (space 37A). However, the space 37A in which the touch sensor 37 is provided is not limited to a notch in the first dimming film 21, and may be composed of notches, hollow portions, etc., provided in at least one of the first and second dimming films 21, 22, adhesive layers 30, 31, 32, or sealing material 35.

[0076] The touch sensor 37 comprises at least a conductive layer, and when a finger, stylus, or other object approaches or comes into contact with any of the transparent panels, an electrical change such as capacitance, current, or voltage occurs, resulting in touch input. In this specification, touch input does not necessarily require the finger, stylus, or other object to be in strict contact with the panel components; it broadly includes cases where a finger or other object approaches and causes an electrical change in the conductive layer. The type of touch sensor is not particularly limited, but examples include capacitive and resistive types. A lead-out electrode (not shown) is connected to the touch sensor 37, and it is preferable that the lead-out electrode be led out to the outside by passing between each layer constituting the interlayer structure, between the sealing material and the transparent panel, etc.

[0077] Figure 7 shows a composite panel structure having an interlayer structure according to another embodiment. In the embodiment shown in Figure 7, the first dimmable film 21 is divided into a plurality of independently controllable segments (segments 26A, 26B, 26C, and 26D in Figure 7), and each segment 26A to 26D can be switched between light transmission and light scattering separately. For example, in the first dimmable film 21, the conductive layer is divided into a plurality corresponding to each segment 26A to 26D, and the application and non-application of voltage can be switched for each segment, thereby allowing independent switching between light transmission mode and light scattering mode for each segment. With this configuration, in this embodiment, it becomes possible to partially shade the composite panel structure, thereby improving usability.

[0078] In the embodiment shown in Figure 7, the first light-adjusting film is divided into segments in an embodiment where the sealing material 35 is not provided. However, as shown in Figures 2 to 5, the film may be divided into multiple segments in an embodiment where the sealing material 35 is provided. Furthermore, in the embodiment shown in Figure 6, the touch sensor 37 is provided in the embodiment in which the sealing material 35 is provided, but for example, the touch sensor may be provided in the embodiment shown in Figure 1 in which the sealing material 35 is not provided. Also, the form of the sealing material 35 when the touch sensor is provided is not limited to the form shown in Figure 6 and may be any form.

[0079] In each embodiment shown with reference to Figures 1 to 7 above, the interlayer structure had a structure comprising first and second light-adjusting films 21 and 22 and transparent adhesive layers 30, 31, and 32, but one or more of the transparent adhesive layers 30, 31, and 32 may be omitted as appropriate. Figure 8 shows an embodiment in which the transparent adhesive layer 30 is omitted. As shown in Figure 8, in the configuration in which the transparent adhesive layer 30 is omitted, the first and second light-adjusting films 21 and 22 may be directly laminated. In this case, the base films of the light-adjusting films 21 and 22 may be bonded to each other by heat pressing or the like, but they may not be bonded. Furthermore, a sealing material 35 is provided on the outer periphery of the first and second light-adjusting films 21 and 22, and the sealing material 35 is preferably bonded to and integrated with the surface transparent adhesive layers 31 and 32. The integrated surface transparent adhesive layers 31 and 32 and the sealing material 35 then support the first and second light-adjusting films 21 and 22, which are positioned to be embedded inside them.

[0080] Furthermore, in the interlayer structure, one or both of the surface transparent adhesive layers 31 and 32 may be omitted instead of the internal transparent adhesive layer 30. In that case, for example, the base films of the first and second light-adjusting films 21 and 22 may be directly bonded to the transparent panels 12 and 13 by heat bonding or the like. Alternatively, all of the transparent adhesive layers 30, 31, and 32 may be omitted.

[0081] The composite panel structure may have three or more dimming films; for example, it may have two or more of the first dimming films described above, or two or more of the second dimming films. The three or more dimming films are preferably arranged along the thickness direction. Furthermore, the dimming film may consist of three or more different types of dimming films arranged in the thickness direction.

[0082] [Optical characteristics when the first dimmable film is in light transmission mode] (Visible light transmittance) In the interlayer structure of the present invention, in a laminated panel structure manufactured using the interlayer structure under predetermined conditions, it is preferable that the visible light transmittance measured with the first light-modulating film in light transmission mode can be adjusted to 1% or less by the second light-modulating film. Furthermore, it is preferable that the visible light transmittance can be adjusted to between 0.1% and 1%, and more preferably between 0.2% and 1%. In this case, the visible light transmittance can be adjusted to the above range by setting the second light-modulating film to light-shielding mode. As mentioned above, adjusting the visible light transmittance to 1% or less allows the interlayer structure to sufficiently block heat rays, preventing the interior of the car from becoming hot due to sunlight when used, for example, in automotive windows, especially roof glass. Furthermore, setting it to 0.1% or higher allows a certain amount of light to pass through, preventing complete shading by the interlayer structure and providing a certain degree of openness. Furthermore, a laminated panel structure manufactured under specified conditions refers to a laminated panel structure obtained by bonding two 2.5 mm thick clear glass sheets (visible light transmittance: 90.4%) via a laminated panel interlayer structure. The same applies hereafter.

[0083] In the present invention, in a composite panel structure manufactured using the interlayer structure under predetermined conditions, it is preferable that the visible light transmittance measured with the first light-transmitting film in light transmission mode can be adjusted by the second light-transmitting film not only to 1% or less as described above, but also to 10% or more. Furthermore, it is more preferable that the visible light transmittance can be adjusted to 20% or more, even more preferably to 30% or more, and also to 10% to 60%, even more preferably to 20% to 50%, and even more preferably to 30% to 50%. In this case, the second light-transmitting film is set to light transmission mode to adjust the visible light transmittance to fall within the above range. When the first dimming film is in light transmission mode, if the second dimming film can be used to adjust the visible light transmittance to 10% or more, the outside becomes easily visible through the composite panel structure. In addition, since a large amount of ambient light can be taken into the interior through the composite panel structure, it becomes possible to take in a certain amount of ambient light even in bad weather or at night, providing a sense of openness even in such environments.

[0084] Furthermore, as mentioned above, if the second dimming film allows the visible light transmittance to be adjusted not only to 1% or less, but also to 10% or more, then when the first dimming film is in light transmission mode, it becomes possible to significantly change the visible light transmittance of the interlayer structure. As a result, it becomes possible to take in more or less ambient light depending on external conditions (for example, weather or time of day), making it easier to achieve a sense of openness regardless of external conditions.

[0085] (Tds) In the present invention, it is preferable that the interlayer structure, in a laminated panel structure manufactured using the interlayer structure under predetermined conditions, allows the Tds (Solar direct transmittance) measured with the first light-modulating film in light-transmission mode to be adjusted to 55% or less. If the Tds measured with the first light-modulating film in light-transmission mode can be adjusted to 55% or less, the interlayer structure can ensure a certain level of heat shielding even when the first light-modulating film is in light-transmission mode, and effectively prevent the inflow of heat rays. To ensure a certain level of heat shielding, it is preferable that the above Tds be adjusted to 55% or less even when the second dimming film is in light transmission mode, but it is even more preferable that it be adjusted to 50% or less when the second dimming film is in light transmission mode. When the first dimming film is in light transmission mode and the second dimming film is in light transmission mode, from the viewpoint of ensuring a certain level of light transmittance, it is preferable that the above Tds be adjusted to, for example, 30% or more.

[0086] Furthermore, from the viewpoint of ensuring sufficient heat shielding even in sunny conditions, for example, when the first light-transmitting film is in light-transmitting mode and the second light-blocking film is in light-blocking mode, the lower the Tds should be, for example, less than 30%, preferably 20% or less, more preferably 15% or less, and practically, for example, 1% or more, but it may also be 10% or more.

[0087] (Haze value) In the interlayer structure of the present invention, it is preferable that the haze value measured when the first light-transmitting film is in light-transmitting mode can be adjusted to 40% or less in a laminated panel structure manufactured using the interlayer structure under predetermined conditions. Adjusting the haze value to 40% or less prevents light scattering when the first light-transmitting film is in light-transmitting mode, making it easier to obtain a sense of openness. The haze value should be 40% or less when the second light-transmitting film is in light-transmitting mode, but it is more preferable that the second light-transmitting film can be adjusted to 40% or less in both light-transmitting mode and light-shielding mode in order to obtain a sufficient sense of openness.

[0088] Furthermore, in order to obtain a certain sense of openness even in bad weather or at night, the haze value when the first dimming film is set to light transmission mode and the second dimming film is also set to light transmission mode should be as low as possible, preferably 20% or less, more preferably 15% or less, and even more preferably 10% or less. In addition, the haze value should be 0% or more, but in practical terms, for example, 1% or more is acceptable.

[0089] [Optical characteristics when the first dimmable film is in light scattering mode] (Visible light transmittance and haze value) In the present invention, it is preferable that the interlayer structure, in a laminated panel structure manufactured using the interlayer structure under predetermined conditions, has a haze value of 70% or more when the first light-adjusting film is in light-scattering mode, and that the visible light transmittance can be adjusted to 20% or less. The haze value is more preferably 80% or more, even more preferably 90% or more, and the visible light transmittance is more preferably 10% or less, even more preferably 5% or less, and even more preferably 1% or less. In the present invention, when the first light-adjusting film is in light-scattering mode, if the visible light transmittance is lowered while the haze value is increased, the laminated panel structure is sufficiently shaded by the first light-adjusting film in light-scattering mode. Furthermore, the interlayer structure only needs to be able to adjust the visible light transmittance and haze value within the above range when the second light-modulating film is at least in light-shielding mode, but it is preferable that the visible light transmittance and haze value can be adjusted within the above range regardless of whether the second light-modulating film is in light-transmitting mode or light-shielding mode.

[0090] (Tds) In the present invention, in a composite panel structure manufactured using the interlayer structure under predetermined conditions, it is preferable that the Tds measured with the first light-diffusing film in light-scattering mode is lower than the Tds when the first light-diffusing film is in light-transmitting mode and the second light-diffusing film is in light-blocking mode. Furthermore, the Tds is preferably less than 10%, more preferably less than 6%. It is desirable that the Tds can be adjusted within the above range regardless of whether the second light-diffusing film is in light-transmitting mode or light-blocking mode, but when the second light-diffusing film is in light-blocking mode, the Tds can be further reduced, preferably less than 4%, and even more preferably less than 3%. Thus, in the present invention, it is possible to make the value of Tds extremely low, and it is also possible to provide heat shielding at a level comparable to that of mechanical shades. Furthermore, the visible light transmittance, Tds, and haze value can be measured by irradiating the surface facing the outdoors with a beam of light. Therefore, in the above-described composite panel structure 10, it is preferable to irradiate the surface with a beam of light from the transparent panel 13 side (i.e., the second dimming film 22 side) when taking the measurements.

[0091] [How to use] The interlayer and laminated panel structures of the present invention can be used in window glass for various vehicles such as automobiles, aircraft, ships, and buildings, but are preferably used for buildings and automobiles. In automobiles, heat rays can enter the vehicle from outside through the windows, causing the interior to become hot. Similarly, in buildings, heat rays can enter the building through the windows, causing the interior to become hot. However, the interlayer structure of the present invention can effectively prevent the inflow of heat rays into the interior of a vehicle or building by appropriately combining the modes of the dimming film to block light.

[0092] Furthermore, the interlayer structure and laminated panel structure of the present invention are particularly preferable for use in automobiles. When used in automobiles, they may be used in any of the windows, such as side windows, rear windows, or roof windows, but are preferable for use in roof windows. Since sunlight shines on the roof window from above, a large amount of heat rays are irradiated onto it, but in the present invention, the interlayer structure can effectively prevent the inflow of heat rays. Moreover, using the interlayer structure and laminated panel structure of the present invention in roof windows makes it easier to obtain an even greater sense of openness.

[0093] Furthermore, a roof glass only needs to be positioned on the roof in some respects; for example, glass positioned across the roof and rear is also considered roof glass. The roof of an automobile is the top surface of the body, and roof glass is generally positioned horizontally, or slightly tilted relative to the horizontal (for example, within 20°). The tilt refers to the angle of a straight line drawn from one end of the glass positioned on the roof to the other, relative to the horizontal. Furthermore, the roof glass is preferably 1 m2 Above, a more comfortable 1.5m 2 It has the above area.

[0094] The interlayer structure and composite panel structure of the present invention are preferably used by appropriately switching the light transmission mode and light scattering mode of the first dimmable film and appropriately adjusting the visible light transmittance of the second dimmable film. Furthermore, as described above, the second dimmable film is switchable between a light transmission mode and a light shielding mode, and if the second dimmable film is, for example, an SPD film, the magnitude of the visible light transmittance can also be adjusted by adjusting the voltage value in the light transmission mode.

[0095] For example, if you want to completely block out external light, you can set the first dimming film to light scattering mode and the second dimming film to light shielding mode. Selecting these modes makes it difficult to see outside through the laminated panel structure, but it lowers the Tds and sufficiently shields against heat rays. Therefore, in an embodiment applied to a roof glass, for example, if the roof glass is not needed, the first and second dimming films can be used to shade it and provide sufficient heat shielding, preventing the interior of the car from becoming hot due to sunlight.

[0096] On the other hand, if you want to see outside through the composite panel structure or if you want to achieve a sense of openness, the first dimming film should be set to light transmission mode. In this case, depending on the external conditions, the second dimming film may be set to either light shielding mode or light transmission mode. If the first dimming film is set to light transmission mode and the second dimming film is set to light shielding mode, the composite panel structure will have a certain degree of heat shielding while also achieving a certain degree of light transmission. On the other hand, if the second dimming film is set to light transmission mode, high light transmission can be obtained, ensuring high visibility. Therefore, in an embodiment applied to roof glass, it is possible to suppress the heating of the interior of the vehicle due to sunlight to a certain extent, while still providing a sense of openness, and to enable observation of the outside through high visibility, depending on the external conditions. Furthermore, with the second dimmable film, for example, using an SPD film, it is possible to adjust the visible light transmittance by adjusting the voltage value applied in the light transmission mode, thus enabling fine-tuning of light transmittance to suit external conditions.

[0097] [Method for manufacturing interlayer structures and composite panel structures] In the present invention, in the production of the interlayer structure, first, a first and second light-adjusting film and, if necessary, a resin film for forming a transparent adhesive layer are prepared. Furthermore, if a sealing material is required, a resin film for sealing material processed into a shape such as a frame is prepared. Then, the first and second light-adjusting films and the adhesive layer resin film are appropriately overlapped, and a sealing resin film is placed on the outer periphery of the light-adjusting film as needed. These are then pressed together in the thickness direction and heat-compressed to produce an interlayer structure. The temperature during heat-compression bonding is, as described above, for example, 30°C to 120°C, but preferably 40°C to 100°C. The pressure during heat-compression bonding is not particularly limited, but bonding by negative pressure is also possible, for example, a gauge pressure of about -780 mbar may be used.

[0098] Next, a laminated panel structure can be manufactured using the obtained interlayer structure and two transparent panels. Specifically, this can be done using a general method for manufacturing laminated glass, and is not particularly limited. For example, the interlayer structure can be placed between two transparent panels and pressed together using an autoclave or the like at a temperature of, for example, 30°C to 120°C or lower, preferably 40°C to 100°C or higher.

[0099] Furthermore, in this invention, a laminated panel structure may be manufactured while forming an interlayer structure. Specifically, the first and second light-adjusting films and the adhesive layer resin film are appropriately overlapped, and a sealing resin film is placed on the outer circumference of the light-adjusting film as needed. These are then placed between two transparent panels and pressed in the thickness direction to perform heat-compression bonding. This forms an interlayer structure while bonding the outermost surface of the interlayer structure to each transparent panel, allowing the interlayer structure and the laminated panel structure to be manufactured in a single process. The temperature during heat-compression bonding is, for example, 30°C to 120°C or lower, but preferably 40°C to 100°C. The pressure during heat-compression bonding is not particularly limited, but negative pressure bonding is also possible, for example, a gauge pressure of about -780 mbar. In addition, when obtaining a laminated panel structure by heat-compression bonding in this method, temporary bonding may be performed as appropriate before heat-compression bonding under the above conditions. [Examples]

[0100] The present invention will be described in more detail by reference to examples, but the present invention is not limited in any way by these examples.

[0101] The methods for measuring the haze value, visible light transmittance, and Tds of dimmable films and laminated panel structures are as follows. [Visible light transmittance (Tv)] Measurements were taken using a spectrophotometer (Hitachi High-Technologies Corporation "U-4100") in accordance with JIS R3106:2019. [Tds] Using a spectrophotometer (Hitachi High-Technologies Corporation "U-4100"), Tds was measured at wavelengths of 300 to 2500 nm in accordance with ISO 13837. [Haze value] The measurement was performed using a haze meter (TC-HIIIDPK, manufactured by Tokyo Denshoku Co., Ltd.) in accordance with JIS K6714. In addition,

[0102] [Example 1] First, the following materials were prepared. The thickness of each layer is as shown in Table 1. Transparent panel: Clear glass plate with a visible light transmittance of 90.4% in accordance with JIS R 3202:2011. First dimmable film: Polymer-dispersed liquid crystal film, manufactured by Gauzy. Light scattering mode when voltage is OFF, light transmission mode when voltage is ON (70V). Second dimmable film: SPD film, manufactured by Gauzy. Light-blocking mode when voltage is OFF, light-transmitting mode when voltage is ON (70V). First and second surface transparent adhesive layers and internal transparent adhesive layer: Resin film (1) made of plasticizer-containing polyvinyl butyral resin, thickness 0.38 mm

[0103] A resin film (1), a first light-adjusting film, a resin film (1), a second light-adjusting film, and a resin film (1) were stacked in this order and heat-pressed at 70°C and -780 mbar (gauge pressure) to integrate them and obtain an interlayer structure. Next, the obtained interlayer structure and another transparent panel were stacked on top of a transparent panel and integrated using an autoclave at 90°C and 3 bar (gauge pressure) to obtain a laminated panel structure. The laminated panel structure had a laminated structure as shown in Figure 1, with two transparent panels bonded together via the interlayer structure.

[0104] [Example 2] The same materials as in Example 1 were used, except that the following resin film (2) was prepared as the resin film for the first and second transparent surface adhesive layers. First and second transparent surface adhesive layers: "S-LEC Film #7082" (colored film) manufactured by Sekisui Chemical Co., Ltd., thickness 0.38 mm

[0105] The resin film (2), the first light-adjusting film, the resin film (1), the second light-adjusting film, and the resin film (2) were stacked in this order and heat-pressed together under the same conditions as in Example 1 to integrate them and obtain an interlayer structure. Subsequently, a laminated panel structure was fabricated in the same manner as in Example 1. The laminated panel structure had a laminated structure as shown in Figure 1, with two transparent panels bonded together via the interlayer structure.

[0106] [Comparative Example 1] In addition to the above-mentioned resin film (1) with a thickness of 0.76 mm, the following resin film (3) was prepared as a resin film for the transparent adhesive layer. Furthermore, a first dimming film and a transparent panel similar to those in Example 1 were prepared. Transparent adhesive layer (resin film (3)): "S-LEC Film #7018" (colored film) manufactured by Sekisui Chemical Co., Ltd., thickness 0.76 mm

[0107] The resin film (1), the first light-adjusting film, and the resin film (3) were stacked in this order and heat-pressed together under the same conditions as in Example 1 to integrate them and obtain an interlayer structure, after which a laminated panel structure was obtained in the same manner as in Example 1. The laminated panel structure had a laminated structure of transparent panel / transparent adhesive layer / first light-adjusting film / transparent adhesive layer / transparent panel.

[0108] [Comparative Example 2] The procedure was carried out in the same manner as in Comparative Example 1, except that a second light-adjusting film was used instead of the first light-adjusting film to obtain an interlayer structure and a laminated panel structure. The laminated panel structure had a laminated structure of transparent panel / transparent adhesive layer / second light-adjusting film / transparent adhesive layer / transparent panel.

[0109] [Comparative Example 3] In addition to the above-mentioned resin film (1) with a thickness of 0.76 mm, the following resin film (4) was prepared as a resin film for the transparent adhesive layer. Furthermore, a first dimming film and a transparent panel similar to those in Example 1 were prepared. Transparent adhesive layer (resin film (4)): "S-LEC Solar Control Film" manufactured by Sekisui Chemical Co., Ltd., thickness 0.76 mm

[0110] The resin film (1), the first light-adjusting film, and the resin film (4) were stacked in this order and heat-pressed together under the same conditions as in Example 1 to integrate them and obtain an interlayer structure, after which a laminated panel structure was obtained in the same manner as in Example 1. The laminated panel structure had a laminated structure of transparent panel / transparent adhesive layer / first light-adjusting film / transparent adhesive layer / transparent panel.

[0111] [Comparative Example 4] The procedure was carried out in the same manner as in Comparative Example 3, except that a second light-adjusting film was used instead of the first light-adjusting film to obtain an interlayer structure and a laminated panel structure. The laminated panel structure had a laminated structure of transparent panel / transparent adhesive layer / second light-adjusting film / transparent adhesive layer / transparent panel.

[0112] [Comparative Example 5] Two sheets of the above-mentioned resin film (1), with a thickness of 0.76 mm, were prepared as resin films for the transparent adhesive layer. In addition, a first dimming film and a transparent panel similar to those in Example 1 were prepared. The resin film (1), the first light-adjusting film, and the resin film (1) were stacked in this order and heat-pressed together under the same conditions as in Example 1 to integrate them and obtain an interlayer structure. A laminated panel structure was fabricated from the obtained interlayer structure in the same manner as in Example 1. The obtained laminated panel structure had a laminated structure of transparent panel / transparent adhesive layer / first light-adjusting film / transparent adhesive layer / transparent panel.

[0113] [Comparative Example 6] The procedure was carried out in the same manner as in Comparative Example 5, except that a second light-adjusting film was used instead of the first light-adjusting film to obtain an interlayer structure and a laminated panel structure. The laminated panel structure had a laminated structure of transparent panel / transparent adhesive layer / second light-adjusting film / transparent adhesive layer / transparent panel.

[0114] For the composite panel structures obtained in the examples and comparative examples, the visible light transmittance, haze value, and Tds were measured when the voltage of the first and second dimming films was switched ON and OFF, respectively. The results are shown in Table 1.

[0115] [Table 1] *The first dimmable film enters light transmission mode when the voltage is ON and light scattering mode when the voltage is OFF. *The second dimmable film enters light transmission mode when the voltage is ON and light blocking mode when the voltage is OFF.

[0116] As shown in Table 1, in each embodiment, when the first dimming film is turned ON, the light transmittance increases when the second dimming film is turned ON, resulting in high visibility. Furthermore, the Tds value remains below a certain value, ensuring a certain level of heat shielding. Also, when the second dimming film is turned OFF while the first dimming film is ON, the Tds value is further reduced, ensuring good heat shielding, and although the visible light transmittance is low, it remains above a certain value, providing a certain sense of openness. On the other hand, when the first dimming film is turned OFF, the second dimming film is also turned OFF, resulting in a low Tds value and sufficient shielding from sunlight. Therefore, the composite panel configurations of each embodiment can ensure heat shielding while providing a sense of openness by switching modes, and furthermore, high visibility can be ensured depending on the mode. In contrast, in Comparative Examples 1, 3, and 5, since there was no second dimming film, when the first dimming film was turned OFF, a low Tds value was obtained and solar radiation could be sufficiently blocked. However, when the first dimming film was turned ON, the Tds value was high, making it difficult to achieve a sense of openness while ensuring sufficient heat shielding. Also, in Comparative Examples 2, 4, and 6, since there was no first dimming film, the Tds value did not become low enough even in light shielding mode, resulting in insufficient heat shielding. [Explanation of Symbols]

[0117] 10. Combined panel structure 11 Interlayer components 12A, 13A, 21A, 22A, 31A, 32A, 33A Peripheral area 12, 13 Transparent panels 21 First dimming film 22. Second dimming film 26A~26D segments 30 Internal transparent adhesive layer 31. First surface transparent adhesive layer 32 Second surface transparent adhesive layer 35 Sealing material 35A First sealing material 35B Second sealing material 37 Touch Sensor L distance

Claims

1. An interlayer structure for laminated panels, which is used sandwiched between two transparent panels, The device comprises a first dimmable film capable of switching between light transmission and light scattering depending on whether or not a voltage is applied, and a second dimmable film capable of adjusting the visible light transmittance depending on whether or not a voltage is applied, wherein the first and second dimmable films are arranged in the thickness direction. An interlayer structure for a composite panel, wherein the second light-adjusting film is at least one selected from the group consisting of an electrochromic film, an SPD film, and an electrophoretic film device.

2. The interlayer film structure for a laminated panel according to claim 1, wherein the second light-adjusting film is positioned on the outdoor side of the first light-adjusting film.

3. The interlayer structure for a laminated panel according to claim 1 or 2, comprising an internal transparent adhesive layer disposed between the first light-adjusting film and the second light-adjusting film for bonding the light-adjusting films together.

4. The interlayer structure for a laminated panel according to claim 3, wherein the first and second light-adjusting films are heat-pressed together via the internal transparent adhesive layer.

5. The interlayer structure for laminated panels according to any one of claims 1 to 4, comprising a transparent surface adhesive layer on the outermost surface of the interlayer structure for laminated panels.

6. A laminated panel structure obtained by bonding two 2.5 mm thick clear glass sheets via the laminated panel interlayer structure, wherein the visible light transmittance measured with the first light-adjusting film as the light transmission mode can be adjusted by the second light-adjusting film to 1% or less and 10% or more, according to any one of claims 1 to 5.

7. A laminated panel structure obtained by bonding two 2.5 mm thick clear glass sheets via the laminated panel interlayer structure, wherein the Tds (Solar direct transmission) measured with the first light-adjusting film as the light transmission mode can be adjusted to 55% or less, according to any one of claims 1 to 6.

8. A laminated panel structure obtained by bonding two 2.5 mm thick clear glass sheets via the laminated panel interlayer structure, wherein the haze value measured with the first light-adjusting film as the light transmission mode can be adjusted to 40% or less, according to any one of claims 1 to 7.

9. The interlayer film structure for a laminated panel according to any one of claims 1 to 8, wherein the first and second dimming films are positioned at least 10 mm inward from the peripheral edge of the transparent panel.

10. The interlayer film structure for a laminated panel according to claim 9, further comprising a sealing material provided on the outer periphery of the first and second dimming films.

11. The interlayer structure for a laminated panel according to any one of claims 1 to 10, further comprising a touch sensor inside the interlayer structure for the laminated panel for controlling at least one of the first and second dimming films.

12. The interlayer film structure for a laminated panel according to any one of claims 1 to 11, wherein the first dimming film is divided into a plurality of independently controllable segments.

13. The interlayer film structure for a laminated panel according to any one of claims 1 to 12, wherein the first dimming film is either a polymer-dispersed liquid crystal film or a polymer network-type liquid crystal.

14. The present invention comprises an interlayer structure for a laminated panel according to any one of claims 1 to 13, and two transparent panels, A laminated panel structure in which the aforementioned interlayer structure for laminated panels is sandwiched between the two transparent panels.

15. The laminated panel structure according to claim 14, wherein the thickness is 7 mm or less.

16. The laminated panel structure according to claim 14 or 15, which is for use with automobile roof glass.

17. The composite panel structure according to claim 14 or 15, which is for use in buildings.

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