Reflective films, laminated glass, and image display systems

Abstract

The objective is to provide a reflective film for a head-up display, laminated glass using the same, and an image display system using the same, which can ensure visible light transmittance in the transparent area of ​​a windshield and also have excellent visibility of the projected image in the light-shielding area. [Solution] The problem is solved by a reflective film having a visible light reflective layer that reflects visible light, and having a first region and a second region in the in-plane direction, wherein the total thickness of the visible light reflective layer in the first region is greater than the total thickness of the visible light reflective layer in the second region.

Description

[Technical Field]

[0001] The present invention relates to a reflective film, laminated glass having the reflective film, and an image display system using the laminated glass. [Background technology]

[0002] A well-known example is the head-up display (or head-up display system), which projects images onto the windshield of a vehicle to provide information to the driver. In the following explanation, the head-up display will also be referred to as "HUD." HUD is an abbreviation for "Head up Display." According to the HUD, drivers can obtain various information such as maps, driving speed, and vehicle status without significantly shifting their gaze while looking at the outside world in front of them. This is expected to allow for safer driving by providing access to various pieces of information.

[0003] The windshield glass onto which the HUD projects the image has a black, frame-like light-blocking area around its periphery. This light-blocking area is commonly called the black ceramic section and is provided for purposes such as preventing deterioration of the adhesive used to fix the windshield glass. In windshield glass, the area inside this light-blocking region is a transparent area that allows the driver or other personnel to see ahead (outside the vehicle). HUDs typically display projected images in the transparent area. However, in recent years, there has been consideration of displaying HUD projected images not only in the transparent area of ​​the windshield glass, but also in the light-blocking area.

[0004] For example, Patent Document 1 contains: A windshield glass (laminated glass) having a first HUD (head-up display) area with a visible light transmittance of approximately 60% or more, and a second HUD area with a visible light transmittance of approximately 30%, It has a projection device capable of generating first and second polarizations containing more than 70% P polarization, The first polarized light is incident on the first HUD region at an incident angle of about 45 to 70°, and the first HUD region has a first reflectance of at least about 15% for P-polarized light incident at 65°, and is used for displaying a first HUD image, The second polarized light is incident on the second HUD region at an incident angle of about 60 to 85°, and the second HUD region has a second reflectance of at least about 10% for P-polarized light incident at 65°, and is used for displaying a second HUD image, A HUD system is described. Prior Art Literature Patent Documents

[0005] Patent Document 1 Japanese National Publication of International Patent Application No. 2024-514777 Summary of the Invention Problem to be Solved by the Invention

[0006] In the HUD system of Patent Document 1, the first HUD region corresponds to a transmission region in windshield glass, the second HUD region corresponds to a light-shielding region in windshield glass, and P-polarized light is projected onto both the transmission region and the light-shielding region to display a projected image.

[0007] Here, in a HUD, in order to improve the visibility of a projected image, a reflective film such as a half mirror may be provided on windshield glass. Also in the windshield glass of the HUD system of Patent Document 1, a first reflective film and a second reflective film are provided corresponding to the first HUD region and the second HUD region. The higher the reflectance of the reflective film, the higher the visibility of the projected image by the HUD. On the other hand, the higher the reflectance of the reflective film, the lower the transmittance. That is, the higher the reflectance of the reflective film, the worse the forward visibility in the transmission region of the windshield glass.

[0008] For example, in the case of automobiles, the transparent area of ​​the windshield glass is required to have a visible light transmittance of 70% or more. Therefore, there were limitations to improving the visibility of the projected image in the transparent area by increasing the reflectivity of the reflective film. On the other hand, in the light-blocking area of ​​the windshield glass, it is not necessary to ensure visible light transmission. Therefore, when displaying a HUD projection image in the light-blocking area, it is possible to improve the visibility of the projection image by increasing the reflectivity of the reflective film.

[0009] However, a reflective film for HUDs that ensures visible light transmittance in the transparent area of ​​the windshield glass while providing excellent visibility of the projected image in the light-blocking area has not yet been realized.

[0010] The object of the present invention is to provide a reflective film for a HUD that can ensure visible light transmittance in the transparent region of a windshield glass with a single film, and also has excellent visibility of the projected image in the light-shielding region, laminated glass using this reflective film, and an image display system using this laminated glass. [Means for solving the problem]

[0011] To achieve the above objective, the present invention has the following configuration. [1] A reflective film for a head-up display system, The reflective film has a functional layer that includes a visible light reflective layer that reflects visible light. The reflective film has a first region and a second region in the in-plane direction, A reflective film in which the total thickness of the visible light reflective layer in the first region is greater than the total thickness of the visible light reflective layer in the second region. [2] The reflective film according to [1], wherein the ratio A / B of the total thickness A of the visible light reflective layer in the first region to the total thickness B of the visible light reflective layer in the second region is 1.5 or greater. [3] The reflective film according to [1] or [2], wherein the visible light reflective layer is a cholesteric liquid crystal layer in which a cholesteric liquid crystal phase is fixed. [4] A reflective film according to any one of [1] to [3], wherein the functional layer has an ultraviolet reflective layer or an isotropic layer in the second region. [5] A reflective film according to any one of [1] to [4], having a first phase difference layer, a functional layer, and a second phase difference layer in this order. [6] The reflective film according to [5], having an adhesive layer on the side opposite to the functional layer of the second phase difference layer. [7] The reflective film according to [5] or [6], having a surface anti-reflective layer on the side opposite to the functional layer of the first phase difference layer. [8] A reflective film according to any one of [1] to [7], wherein the reflective film has two or more visible light reflective layers having the same selective reflection center wavelength, and further has an adhesive layer between the visible light reflective layers having the same selective reflection center wavelength. [9] The functional layer has a visible light reflective layer in the first region, and in the second region, a visible light reflective layer and an ultraviolet reflective layer or an isotropic layer are laminated in the thickness direction, and A reflective film according to any one of [1] to [7], wherein the selective reflection center wavelength of the visible light reflective layer in the first region and the selective reflection center wavelength of the visible light reflective layer in the second region are the same.

[10] Laminated glass comprising, in this order, an outer glass panel, an interlayer, an inner glass panel, and a reflective film as described in any of [1] to [9].

[11] An image display system comprising laminated glass as described in

[10] and a projector that projects an image onto a reflective film of the laminated glass. [Effects of the Invention]

[0012] According to the present invention, a reflective film for a HUD can ensure visible light transmittance in the transparent region of the windshield glass with a single film, and provide excellent visibility of the projected image in the light-blocking region of the windshield glass. [Brief explanation of the drawing]

[0013] [Figure 1] This figure conceptually illustrates an example of the image display system of the present invention. [Figure 2] This figure conceptually illustrates an example of the reflective film of the present invention. [Figure 3] Figure 2 is a schematic, partially enlarged view of the reflective film shown. [Figure 4] This is a conceptual diagram illustrating one example of a method for forming a visible light reflective layer. [Figure 5] This is a conceptual diagram illustrating another example of a method for forming a visible light reflective layer. [Figure 6] This figure conceptually illustrates an example of the reflective film of the present invention. [Figure 7] This is a conceptual diagram illustrating a method for evaluating the visibility of a projected image in an embodiment of the present invention. [Modes for carrying out the invention]

[0014] The reflective film, laminated glass, and image display system of the present invention will be described in detail below based on preferred embodiments shown in the attached drawings.

[0015] In this specification, "~" is used to mean that the numbers before and after it include the lower and upper limits, respectively.

[0016] In this specification, visible light refers to electromagnetic waves with wavelengths visible to the human eye, specifically light in the wavelength range of 380 to 780 nm. Invisible light refers to light with wavelengths less than 380 nm or greater than 780 nm. While not limited to these, within visible light, light in the wavelength range of 420 to 490 nm is blue light (B light), light in the wavelength range of 495 to 570 nm is green light (G light), and light in the wavelength range of 620 to 750 nm is red light (R light). Furthermore, while not limited to these, infrared light refers to non-visible light with wavelengths greater than 780 nm and less than or equal to 2000 nm.

[0017] Furthermore, in this specification, the terms "liquid crystal composition" and "liquid crystal compound" also include, conceptually, materials that no longer exhibit liquid crystal properties due to curing or other reasons.

[0018] In this specification, Re(λ) and Rth(λ) represent the in-plane retardation and thickness-direction retardation at wavelength λ, respectively. Unless otherwise specified, wavelength λ is assumed to be 550 nm. Furthermore, in this specification, Re(λ) and Rth(λ) are values ​​measured at wavelength λ using an AxoScan OPMF-1 (manufactured by OptoScience Co., Ltd.). Specifically, by inputting the average refractive index ((nx+ny+nz) / 3) and film thickness (d) into AxoScan OPMF-1, Slow axis direction (°) Re(λ)=R0(λ) Rth(λ)=((nx+ny) / 2-nz)×d This is calculated. Note that R0(λ) is a value displayed by the AxoScan OPMF-1, and it means Re(λ).

[0019] Figure 1 conceptually shows an example of a HUD (Head-Up Display) system using the image display system of the present invention. The HUD system 10 shown in Figure 1 includes a projector 12 and a windshield glass 14. The windshield glass 14 is a laminated glass according to the present invention and comprises an outer glass plate 16, an inner glass plate 18, an interlayer 20 sandwiched between the outer glass plate 16 and the inner glass plate 18, and a reflective film 30 according to the present invention. Furthermore, the windshield glass 14 has a black light-blocking area 26 framed around the inner side of the outer glass panel 16. In the windshield glass 14, the area inside this light-blocking area 26 is a transparent area for the driver to see ahead (outside the vehicle). As shown in Figure 1, in the windshield glass 14, the reflective film 30 of the present invention is provided on the surface of the interior glass plate 18, that is, on the interior surface of the windshield glass 14.

[0020] Similar to known HUD systems, the HUD system 10 allows the driver U to observe the projected image by directing the projected image emitted by the projector 12 onto the reflective film 30 of the present invention, which is provided on the surface of the glass panel 18 on the inside of the vehicle, and reflecting it. Here, the HUD system 10, which is an image display system of the present invention, displays a projected image by incidenting a projected image onto both the region of the reflective film 30 corresponding to the light-shielding region 26 of the windshield glass 14 (first region) and the region of the reflective film 30 corresponding to the transparent region of the windshield glass 14 (second region), and reflecting the projected image. In other words, the HUD system 10 is an image display system that displays a projected image (picture) on both the light-blocking and light-transmitting areas of the windshield glass 14.

[0021] In the HUD system 10, there are no restrictions on the projector. Therefore, various known projectors (imagers) used in known HUD systems can be used, such as projectors that emit an image (projected light) displayed by a liquid crystal display device, and projectors that emit an image as a projected image displayed by an organic electroluminescent display device. Furthermore, in the HUD system 10, as shown in Figure 1, a single projector 12 may be used to display projected images in both the light-blocking and transparent areas of the windshield glass 14. Alternatively, the HUD system 10 may have multiple projectors, such as a projector for displaying projected images in the light-blocking area of ​​the windshield glass 14 and a projector for displaying projected images in the transparent area of ​​the windshield glass 14.

[0022] Furthermore, in the HUD system 10, it is preferable that the projector 12 emits P-polarized light as the projected image. The projector 12 is preferable in that it emits P-polarized light as the projected image, allowing the driver to observe the projected image of the HUD system 10 even when wearing polarized sunglasses, and preventing double images.

[0023] As described above, the windshield glass 14 is a laminated glass according to the present invention, and comprises an outer glass plate 16, an interlayer 20, an inner glass plate 18, and a reflective film 30 according to the present invention, in that order. In addition, a frame-shaped light-shielding region 26 is formed on the inner peripheral portion of the outer glass plate 16.

[0024] In the windshield glass 14, the outer glass plate 16 and the inner glass plate 18 can be made of known glass plates commonly used for windshield glass, such as green glass. The interlayer 20 sandwiched between the outer glass plate 16 and the inner glass plate 18 is also a known interlayer used in laminated glass used as a windshield glass. Examples of the interlayer 20 include polyvinyl butyral (PVB), ethylene-vinyl acetate copolymer, and resin films containing resins such as chlorine-containing resins.

[0025] In the windshield glass 14, the black light-shielding region 26 provided in a frame shape around the periphery can be any of the known light-shielding regions (black ceramic portion) provided in a frame shape around the periphery of an automobile's windshield glass, such as a light-shielding region (low visible light transmission region) formed by printing black ceramic onto the inner surface of the outer glass plate 16.

[0026] In the windshield glass 14, the reflective film 30 of the present invention is attached to the surface of the inner glass plate 18, that is, the inner surface. The reflective film of the present invention is a reflective film for HUDs and has a functional layer including a visible light reflective layer that reflects visible light. Furthermore, the reflective film of the present invention has a first region and a second region in the in-plane direction, and the total thickness of the visible light reflective layer in the first region is greater than the total thickness of the visible light reflective layer in the second region. Here, the first region is provided to correspond to the light-shielding region 26 of the windshield glass 14 described above. On the other hand, the second region is provided to correspond to the light-transmitting region of the windshield glass 14 described above. The reflective film of the present invention, having such a configuration, ensures visible light transmittance in the transparent region and, in a HUD that displays a projected image in both the transparent and shading regions of a windshield glass, achieves excellent visibility of the projected image (displayed image) in the shading region.

[0027] Figure 2 conceptually shows an example of the reflective film 30 of the present invention. The reflective film 30 shown in Figure 2 has, from bottom to top in the figure, a surface anti-reflective layer 32, a first support 34, a first phase difference layer 36, a first functional layer 38IR, a second functional layer 40R, a third functional layer 42BG, a first adhesive layer 50, a fourth functional layer 52IR, a fifth functional layer 54R, a sixth functional layer 56BG, a second phase difference layer 58, a second support 60, and a second adhesive layer 62.

[0028] In the reflective film shown in Figure 2, the region indicated by arrow F is the first region in the in-plane direction and corresponds to the light-shielding region 26 of the windshield glass 14. Furthermore, the region indicated by arrow S in Figure 2 is the second region in the in-plane direction, and corresponds to the transmission region of the windshield glass 14. For convenience, in the following explanation, and following the arrows in the diagram, the first region will also be referred to as "First Region F" and the second region as "Second Region S".

[0029] In the reflective film 30, the projected image (projected light) emitted by the projector 12 is incident from the side of the surface anti-reflective layer 32. In this configuration, all functional layers of the reflective film 30 have visible light reflective layers in the first region F, while in the second region S, the fourth functional layer 52IR, the fifth functional layer 54R, and the sixth functional layer 56BG do not have visible light reflective layers. In other words, the total thickness of the visible light reflective layers in the first region is greater than the total thickness of the visible light reflective layers in the second region.

[0030] Therefore, in the first region F, i.e., the light-shielding region 26, the projected image incident on the reflective film 30 is partially reflected by the first functional layer 38IR, the second functional layer 40R, and the third functional layer 42BG, depending on the wavelength, and further partially reflected by the fourth functional layer 52IR, the fifth functional layer 54R, and the sixth functional layer 56BG. In contrast, in the second region S, or the transmission region, the projected image incident on the reflective film 30 is partially reflected by the first functional layer 38IR, the second functional layer 40R, and the third functional layer 42BG, depending on the wavelength, but is transmitted through the fourth functional layer 52IR, the fifth functional layer 54R, and the sixth functional layer 56BG.

[0031] In other words, in the reflective film 30 of the present invention, the first region F corresponding to the light-shielding region 26 has a higher reflectivity of the projected image than the second region S corresponding to the light-transmitting region. Therefore, in the reflective film 30 of the present invention, the second region S corresponding to the light-transmitting region has a higher visible light transmittance than the first region F corresponding to the light-shielding region 26. The reflective film 30 of the present invention, having this configuration, ensures sufficient visible light transmittance in the transmission region and achieves excellent visibility of the projected image in the light-shielding region. This point will be described in detail later.

[0032] In a preferred embodiment, the reflective film 30 has a surface anti-reflective layer 32 on the incident surface of the projected image from the projector 12. As described above, the reflective film 30 of the present invention has a high reflectivity in the first region F corresponding to the light-shielding region 26. When the reflective film 30 of the present invention having such a configuration is used in a HUD, the dashboard of the car may be reflected in the first region F. In contrast, by having a surface anti-reflective layer 32 on the surface of the reflective film 30, it is possible to suppress the reflection of the dashboard on the reflective film 30.

[0033] In the reflective film 30 of the present invention, there are no restrictions on the surface anti-reflective layer 32, and various known surface anti-reflective layers (anti-reflective layers) can be used. Examples of surface anti-reflective coatings 32 include inorganic films such as titanium, titanium dioxide, titanium nitride, chromium oxide, silicon oxide, carbon, and amorphous silicon; laminated films formed by stacking two or more of these inorganic films; organic films consisting of a light absorber and polymer material; and moth-eye films. There are no restrictions on the thickness of the surface anti-reflective layer 32; the thickness that provides the necessary anti-reflective performance can be appropriately set according to the forming material, etc.

[0034] A first support 34 is provided on the upper surface of the surface anti-reflective layer 32 in the figure. As an example, the reflective film 30 shown in Figure 2 is produced by creating a laminate having a surface anti-reflective layer 32, a first support 34, a first phase difference layer 36, a first functional layer 38IR, a second functional layer 40R, and a third functional layer 42BG, and a laminate having a fourth functional layer 52IR, a fifth functional layer 54R, a sixth functional layer 56BG, a second phase difference layer 58, and a second support 60, and then bonding the two with a first adhesive layer 50. The first support 34 is primarily for supporting the surface anti-reflective layer 32, the first phase difference layer 36, the first functional layer 38IR, the second functional layer 40R, and the third functional layer 42BG in the former laminate.

[0035] The first support 34 preferably has a high visible light transmittance. Specifically, the visible light transmittance of the first support 34 is preferably 80% or higher, more preferably 85% or higher, even more preferably 87% or higher, and particularly preferably 90% or higher. Furthermore, the upper limit of the visible light transmittance of the first support 34 is preferably 100% or less. Furthermore, it is preferable that the first support 34 has a low in-plane retardation Re. The in-plane retardation Re of the first support 34 is preferably 10 nm or less, more preferably 5 nm or less, and even more preferably 2 nm or less. In addition, it is preferable that the lower limit of the in-plane retardation Re of the first support 34 is 0 nm or more.

[0036] There are no restrictions on the material used to form the first support 34; preferably, any resin material can be used as long as it satisfies the above-mentioned visible light transmittance and in-plane retardation Re. Examples include TAC (triacetylcellulose), PMMA (polymethyl methacrylate), COP (cycloolefin polymer), PC (polycarbonate), and PET (polyethylene terephthalate).

[0037] There are no restrictions on the thickness of the first support 34; a thickness that can support the functional layer and the first phase difference layer 36, etc., can be appropriately set depending on the material used to form the first support 34.

[0038] In the reflective film 30, a first phase difference layer 36 is provided on the upper surface of the first support 34 in the figure, as a preferred embodiment. The first phase difference layer 36 converts the projected image from the projector 12 into circularly polarized light in a direction that can be reflected by the visible light reflection layer described later, when the projected image is linearly polarized. As described above, in the HUD system 10, it is preferable for the projector 12 to emit P-polarized light as the projected image. Therefore, in this case, the first phase difference layer 36 converts the incident P-polarized light into circularly polarized light in the direction of rotation that the visible light reflective layer can reflect. That is, when the visible light reflective layer selectively reflects right-circularly polarized light, the first phase difference layer 36 converts the incident P-polarized light into right-circularly polarized light. Also, when the visible light reflective layer selectively reflects left-circularly polarized light, the first phase difference layer 36 converts the incident P-polarized light into left-circularly polarized light.

[0039] There are no restrictions on the first phase difference layer 36; any known phase difference layer (λ / 4 phase difference layer) that can convert incident linearly polarized light into circularly polarized light can be used. Examples include stretched polycarbonate films, stretched norbornene-based polymer films, transparent films containing and oriented inorganic particles with birefringence such as strontium carbonate, thin films in which an inorganic dielectric is obliquely deposited on a support, films in which polymerizable liquid crystal compounds are uniaxially oriented (especially horizontally oriented) and their orientation fixed, and films in which liquid crystal compounds are uniaxially oriented (especially horizontally oriented) and their orientation fixed. Here, regarding horizontal orientation, when the liquid crystal compound is a rod-shaped liquid crystal compound, horizontal orientation is also called homogeneous orientation, and it means an orientation in which the angle between the surface (main surface) of the phase difference layer and the director of the rod-shaped liquid crystal compound is in the range of 0° to 20°, with an orientation in the range of 0° to 10° being preferred, and an orientation in the range of 0° to 5° being more preferred. Furthermore, when the liquid crystal compound is a disc-shaped liquid crystal compound, horizontal orientation means an orientation in which the angle between the surface (main surface) of the phase difference layer and the disc surface of the disc-shaped liquid crystal compound is within the range of 0° to 20°, with orientations within the range of 0° to 10° being preferred, and orientations within the range of 0° to 5° being more preferred. The first phase difference layer is preferably an A plate, and more preferably a positive A plate.

[0040] In this specification, a positive A plate is defined as follows: In other words, a positive A plate is one that satisfies the relationship in equation (A1), where nx is the refractive index in the slow axis direction (the direction in which the refractive index is maximum in the plane) within the film (phase difference layer), ny is the refractive index in the direction perpendicular to the slow axis in the plane, and nz is the refractive index in the thickness direction. Note that a positive A plate exhibits a positive value for Rth. Formula (A1) nx>ny≒nz Furthermore, the above "≒" includes not only cases where the two are completely identical, but also cases where they are substantially identical. "Substantially identical" means, for example, that (ny-nz) × d (where d is the thickness of the film (phase difference layer)) is -10 to 10 nm, preferably -5 to 5 nm, which is also included in "ny≒nz".

[0041] There are no restrictions on the in-plane retardation Re(550) of the first phase difference layer 36; it can be set appropriately according to the phase difference required for the first phase difference layer 36. Specifically, the in-plane retardation Re(550) of the first phase difference layer 36 is preferably 100 to 170 nm, more preferably 110 to 160 nm, and even more preferably 120 to 150 nm.

[0042] On the upper surface of the first phase difference layer 36 in the figure, the first functional layer 38IR, the second functional layer 40R, and the third functional layer 42BG are provided in this order. The first functional layer 38IR, the second functional layer 40R, and the third functional layer 42BG are all visible light reflective layers in the present invention. In the present invention, the visible light reflective layer is a reflective layer having a selective reflection center wavelength in the range of 380 to 850 nm.

[0043] As long as the visible light reflective layer has a selective reflection center wavelength within the above range, various known reflective layers that selectively reflect light in a specific wavelength range can be used. Among these, a cholesteric liquid crystal layer with a fixed cholesteric liquid crystal phase is preferably used. The first functional layer 38IR, the second functional layer 40R, and the third functional layer 42BG shown in Figure 2 are, as an example, all cholesteric liquid crystal layers. In the illustrated example, the first functional layer 38IR is, for example, a cholesteric liquid crystal layer having a selective reflection center wavelength in the infrared wavelength range. The second functional layer 40R is, for example, a cholesteric liquid crystal layer having a selective reflection center wavelength in the red light wavelength range. Furthermore, the third functional layer 42BG is a cholesteric liquid crystal layer having a selective reflection center wavelength in the green light or blue light wavelength range.

[0044] As is well known, cholesteric liquid crystal layers selectively reflect right-circularly polarized or left-circularly polarized light in a specific wavelength range. In this preferred embodiment, when the projector 12 emits P-polarized light as projected light and the first phase difference layer 36 converts the P-polarized light to right-circularly polarized light, the cholesteric liquid crystal layer, which is the visible light reflective layer, selectively reflects the right-circularly polarized light. On the other hand, in a preferred embodiment, when the projector 12 emits P-polarized light as projected light and the first phase difference layer 36 converts the P-polarized light to left-circularly polarized light, the cholesteric liquid crystal layer, which is the visible light reflective layer, selectively reflects the left-circularly polarized light.

[0045] Furthermore, as is well known, the cholesteric liquid crystal layer has a helical structure in which liquid crystal compounds are stacked in a spiral. The structure is such that multiple helical pitches (spiral pitch P) are stacked, with each layer consisting of one spiral rotation (360° rotation) of liquid crystal compounds. The longer the length of this helical pitch P, the more selectively it reflects long-wavelength light.

[0046] In this case, the cholesteric liquid crystal layer exhibits a so-called short-wave shift (blue shift), where the selectively reflected wavelength becomes shorter when light is incident from an oblique direction. Furthermore, in many cases, the projected image emitted by the projector 12 of the HUD passes through a window formed in the vehicle's dashboard and enters the windshield glass 14, i.e., the reflective film 30. Therefore, the direction of incidence of light to the reflective film 30 is not from the front (normal direction), but from an oblique direction, for example, from a direction with an incidence angle of about 65°. Furthermore, the direction in which the driver observes the projected image from the HUD is often not directly in front of the reflective film 30 (normal direction), and it is also highly likely to vary from driver to driver.

[0047] In other words, in the illustrated example of the reflective film 30, the first functional layer 38IR, which has a selective reflection center wavelength in the infrared wavelength range, is provided to reflect red light on the long wavelength side, corresponding to the incident direction of the projected image from the projector 12 and the short-wave shift of the cholesteric liquid crystal layer due to observation by the driver from an oblique direction. In other words, in the reflective film of the present invention, the helical pitch P of each visible light reflective layer is set appropriately to reflect light in the corresponding wavelength range, taking into account the short-wave shift of the cholesteric liquid crystal layer according to the incident direction of the projected image from the projector 12 and the observation direction by the driver.

[0048] The reflective film 30 in the illustrated example reflects red, green, and blue light and corresponds to a full-color projected image, but the present invention is not limited thereto. In other words, the reflective film of the present invention may reflect only one color of light from red, green, and blue, or it may reflect two colors selected from red, green, and blue. Furthermore, the reflective film of the present invention may also have a visible light reflective layer that selectively reflects blue light and a visible light reflective layer that selectively reflects green light, provided separately.

[0049] [Cholesteric liquid crystal layer] A cholesteric liquid crystal layer is a layer in which the orientation of the liquid crystal compound in the cholesteric liquid crystal phase is maintained. Typically, a cholesteric liquid crystal layer is formed by polymerizing and curing a polymerizable liquid crystal compound in the orientation of the cholesteric liquid crystal phase by ultraviolet irradiation and heating, thereby forming a non-fluid layer that simultaneously changes in orientation to a state that does not change due to external fields or external forces. In addition, it is sufficient that the optical properties of the cholesteric liquid crystal phase are maintained within the layer, and the liquid crystal compound in the layer does not need to exhibit liquid crystalline properties anymore. For example, a polymerizable liquid crystal compound may have its molecular weight increased by the curing reaction and may no longer have liquid crystalline properties.

[0050] Cholesteric liquid crystal phases are known to exhibit selective circular polarization reflection, which selectively reflects circularly polarized light of either right-circularly polarized or left-circularly polarized light, while transmitting circularly polarized light of the other sense. Many films formed from compositions containing polymerizable liquid crystal compounds have been conventionally known as films containing a layer on which a cholesteric liquid crystal phase exhibiting selective circular polarization reflectivity is fixed, and prior art can be referenced for the cholesteric liquid crystal layer.

[0051] The center wavelength λ of selective reflection by the cholesteric liquid crystal layer depends on the pitch P (=period of the helix) of the helical structure (helical orientation structure) in the cholesteric liquid crystal phase, and follows the relationship between the average refractive index n of the cholesteric liquid crystal layer and λ = n × P. As can be seen from this equation, the center wavelength of selective reflection can be adjusted by adjusting the n value and / or the P value. The pitch P of a helical structure (one helical pitch) is, in other words, the length in the helical axis direction corresponding to one turn of the helix. That is, pitch P is the length in the helical axis direction over which the director (long axis direction in the case of a rod-shaped liquid crystal) of the liquid crystal compound constituting the cholesteric liquid crystal phase rotates 360°. The helical axis direction of a typical cholesteric liquid crystal layer coincides with the thickness direction of the cholesteric liquid crystal layer.

[0052] The helical pitch of the cholesteric liquid crystal phase depends on the type of chiral agent used with the polymerizable liquid crystal compound and its concentration; therefore, the desired pitch can be obtained by adjusting these factors. For methods of measuring the helical sense and pitch, the methods described in "Introduction to Liquid Crystal Chemistry Experiments" edited by the Japanese Liquid Crystal Society, Sigma Publishing, 2007, p. 46, and "Liquid Crystal Handbook" edited by the Liquid Crystal Handbook Editorial Committee, Maruzen, p. 196, can be used.

[0053] Each cholesteric liquid crystal layer used is one in which the helical sense is either right-handed or left-handed. The sense of circularly polarized light reflected by the cholesteric liquid crystal layer (the optical rotation direction of the circularly polarized light) coincides with the helical sense. Furthermore, it is preferable that the multiple cholesteric liquid crystal layers, each with a different selective reflection center wavelength, all have the same helical sense, that is, the same optical rotation direction of the reflected circularly polarized light.

[0054] The half-width Δλ (nm) of the selective reflection band exhibiting selective reflection depends on the birefringence Δn of the liquid crystal compound and the pitch P described above, following the relationship Δλ = Δn × P. Therefore, the width of the selective reflection band can be controlled by adjusting Δn. Δn can be adjusted by changing the type or mixing ratio of the polymerizable liquid crystal compound, or by controlling the temperature during orientation fixation. To form a single type of cholesteric liquid crystal layer with the same central wavelength for selective reflection, multiple cholesteric liquid crystal layers with the same pitch P and the same helical sense may be stacked. By stacking cholesteric liquid crystal layers with the same pitch P and the same helical sense, circular polarization selectivity can be increased at a specific wavelength.

[0055] The selective reflection center wavelength and full width at half maximum (FWHM) of a cholesteric liquid crystal layer can be determined, for example, as follows. When the reflection spectrum of the cholesteric liquid crystal layer is measured from the normal direction using a spectrophotometer (JASCO Corporation, V-670), a peak in transmittance decrease is observed in the selective reflection region. Of the two wavelengths that result in the midpoint (average) transmittance between the minimum transmittance at this peak and the transmittance before the decrease, the value of the shorter wavelength is λ. l (nm), the wavelength value on the longer wavelength side is λ h If (nm), the selective reflection center wavelength λ and the full width at half maximum Δλ can be expressed by the following equations. λ=(λ l +λ h ) / 2Δλ=(λ h -λ l ) As described above, the selective reflection center wavelength obtained is approximately the same as the wavelength at the centroid of the reflection peak in the circularly polarized reflection spectrum measured from the normal direction of the cholesteric liquid crystal layer.

[0056] As shown in the illustrated example, when there are multiple functional layers having cholesteric liquid crystal layers with different selective reflection center wavelengths, the functional layers may be laminated using an adhesive or the like after separately manufactured functional layers, or a liquid crystal composition (coating solution) containing a polymerizable liquid crystal compound or the like may be directly applied to the surface of the previously formed functional layer using the method described later, and the orientation and fixing steps may be repeated, but the latter is preferred.

[0057] (Method for fabricating a cholesteric liquid crystal layer) The following describes the materials and methods for fabricating the cholesteric liquid crystal layer. Materials used to form the cholesteric liquid crystal layer described above include liquid crystal compositions containing polymerizable liquid crystal compounds and chiral agents (optically active compounds). If necessary, the above-mentioned liquid crystal composition, which has been mixed with a surfactant and a polymerization initiator and dissolved in a solvent, can be applied to a support, an alignment film, or a lower cholesteric liquid crystal layer. After cholesteric alignment maturation, the liquid crystal composition can be fixed by curing to form the cholesteric liquid crystal layer.

[0058] (Polymerizable liquid crystal compound) The polymerizable liquid crystal compound may be a rod-shaped liquid crystal compound or a disc-shaped liquid crystal compound, but a rod-shaped liquid crystal compound is preferred. Examples of rod-shaped polymerizable liquid crystal compounds that form a cholesteric liquid crystal layer include rod-shaped nematic liquid crystal compounds. Preferred rod-shaped nematic liquid crystal compounds include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyanosubstituted phenylpyrimidines, alkoxysubstituted phenylpyrimidines, phenyldioxanes, trans, and alkenylcyclohexylbenzonitriles. Not only low molecular weight liquid crystal compounds but also high molecular weight liquid crystal compounds can be used.

[0059] Polymerizable liquid crystal compounds are obtained by introducing polymerizable groups into liquid crystal compounds. Examples of polymerizable groups include unsaturated polymerizable groups, epoxy groups, and aziridinyl groups, with unsaturated polymerizable groups being preferred and ethylenically unsaturated polymerizable groups being particularly preferred. Polymerizable groups can be introduced into the molecules of liquid crystal compounds by various methods. The number of polymerizable groups in a polymerizable liquid crystal compound is preferably 1 to 6 per molecule, more preferably 1 to 3. Examples of polymerizable liquid crystal compounds can be found in Makromol. Chem., Vol. 190, p. 2255 (1989), Advanced Materials. This includes compounds described in sections

[0014] to

[0057] of Volume 5, page 107 (1993), U.S. Patent No. 4,683,327, U.S. Patent No. 5,622,648, U.S. Patent No. 5,770,107, International Publication No. 1995 / 22586, International Publication No. 1995 / 24455, International Publication No. 1997 / 00600, International Publication No. 1998 / 23580, International Publication No. 98 / 52905, Japanese Patent Publication No. 1-272551, Japanese Patent Publication No. 6-16616, Japanese Patent Publication No. 7-110469, Japanese Patent Publication No. 11-80081, Japanese Patent Publication No. 2001-328973, and Japanese Patent Publication No. 2014-198814. Two or more polymerizable liquid crystal compounds may be used in combination. Using two or more polymerizable liquid crystal compounds in combination can lower the orientation temperature.

[0060] Furthermore, the amount of polymerizable liquid crystal compound added to the liquid crystal composition is preferably 80 to 99.9% by mass, more preferably 85 to 99.5% by mass, and particularly preferably 90 to 99% by mass, relative to the solid content mass (mass excluding solvent) of the liquid crystal composition.

[0061] To improve visible light transmittance, the cholesteric liquid crystal layer may have a low Δn. A low Δn cholesteric liquid crystal layer can be formed using a low Δn polymerizable liquid crystal compound. The following describes low Δn polymerizable liquid crystal compounds in detail.

[0062] (Low Δn polymerizable liquid crystal compound) A cholesteric liquid crystal phase can be formed using a low-Δn polymerizable liquid crystal compound, and a film on which this phase is fixed can be obtained to acquire a narrow-band selective reflective layer. Examples of low-Δn polymerizable liquid crystal compounds include those described in International Publication Nos. 2015 / 115390, 2015 / 147243, 2016 / 035873, Japanese Patent Publication Nos. 2015-163596 and 2016-53149. For liquid crystal compositions that provide a selective reflective layer with a small full width at half maximum, please also refer to the description in International Publication No. 2016 / 047648.

[0063] The liquid crystal compound is also preferably a polymerizable compound represented by the following formula (I) described in International Publication No. WO 2016 / 047648.

[0064]

Chemical Formula

[0065] In formula (I), A represents an optionally substituted phenylene group or an optionally substituted trans-1,4-cyclohexylene group; L represents a linking group selected from the group consisting of a single bond, -CH2O-, -OCH2-, -(CH2)2OC(=O)-, -C(=O)O(CH2)2-, -C(=O)O-, -OC(=O)-, -OC(=O)O-, -CH=CH-C(=O)O-, and -OC(=O)-CH=CH-; m represents an integer of 3 to 12; Sp 1 and Sp 2 each independently represent a linking group selected from the group consisting of: a single bond; a linear or branched alkylene group having 1 to 20 carbon atoms; and a group obtained by substituting one or more -CH2- groups in a linear or branched alkylene group having 1 to 20 carbon atoms with -O-, -S-, -NH-, -N(CH3)-, -C(=O)-, -OC(=O)-, or -C(=O)O-; Q 1 and Q 2 each independently represent a hydrogen atom or a polymerizable group selected from the group consisting of groups represented by the following formulas Q-1 to Q-5, provided that either one of Q 1 and Q 2 represents a polymerizable group.

[0066]

Chemical Formula

[0067] Examples of polymerizable compounds represented by formula (I) include, in addition to the compounds described in paragraphs 0051 to 0058 of International Publication No. 2016 / 047648, the compounds described in Japanese Patent Publication No. 2013-112631, Japanese Patent Publication No. 2010-70543, Japanese Patent No. 4725516, International Publication No. 2015 / 115390, International Publication No. 2015 / 147243, International Publication No. 2016 / 035873, Japanese Patent Publication No. 2015-163596, and Japanese Patent Publication No. 2016-53149.

[0068] (Chiral agents: optically active compounds) Chiral agents have the function of inducing a helical structure in the cholesteric liquid crystal phase. Since different chiral compounds induce different helical senses or helical pitches, they should be selected according to the purpose. There are no particular restrictions on the chiral agent, and known compounds can be used. Examples of chiral agents include compounds described in the Liquid Crystal Device Handbook (Chapter 3, Section 4-3, Chiral Agents for TN and STN, p. 199, edited by the 142nd Committee of the Japan Society for the Promotion of Science, 1989), Japanese Patent Publication Nos. 2003-287623, 2002-302487, 2002-80478, 2002-80851, 2010-181852, and 2014-034581.

[0069] Chiral agents generally contain an asymmetric carbon atom, but axially asymmetric or planar asymmetric compounds that do not contain an asymmetric carbon atom can also be used as chiral agents. Examples of axially asymmetric or planar asymmetric compounds include binaphthyl, helicene, paracyclophane, and their derivatives. The chiral agent may have polymerizable groups. When both the chiral agent and the liquid crystal compound have polymerizable groups, a polymerization reaction between the polymerizable chiral agent and the polymerizable liquid crystal compound can form a polymer having repeating units derived from the polymerizable liquid crystal compound and repeating units derived from the chiral agent. In this embodiment, it is preferable that the polymerizable groups of the polymerizable chiral agent are of the same type as the polymerizable groups of the polymerizable liquid crystal compound. Therefore, the polymerizable groups of the chiral agent are preferably unsaturated polymerizable groups, epoxy groups, or aziridinyl groups, more preferably unsaturated polymerizable groups, and particularly preferably ethylenically unsaturated polymerizable groups. Furthermore, the chiral agent may be a liquid crystal compound.

[0070] As chiral agents, isosorbide derivatives, isomannide derivatives, and binaphthyl derivatives can be preferably used. As isosorbide derivatives, commercially available products such as LC756 manufactured by BASF may be used. In the liquid crystal composition, the chiral agent content is preferably 0.01 to 200 mol%, and more preferably 1 to 30 mol%, relative to the amount of polymerizable liquid crystal compound. The chiral agent content in the liquid crystal composition refers to the concentration (mass%) of the chiral agent relative to the total solid content in the composition.

[0071] (Polymerization initiator) The liquid crystal composition preferably contains a polymerization initiator. In the embodiment in which the polymerization reaction is carried out by ultraviolet irradiation, the polymerization initiator used is preferably a photopolymerization initiator that can initiate the polymerization reaction by ultraviolet irradiation. Examples of photopolymerization initiators include α-carbonyl compounds (described in U.S. Patent Nos. 2,367,661 and 2,367,670), acyloin ethers (described in U.S. Patent No. 2,448,828), α-hydrocarbon-substituted aromatic acyloin compounds (described in U.S. Patent No. 2,722,512), polynuclear quinone compounds (described in U.S. Patent Nos. 3,046,127 and 2,951,758), combinations of triarylimidazole dimers and p-aminophenyl ketones (described in U.S. Patent No. 3,549,367), acridine and phenazine compounds (described in Japanese Patent Publication No. 60-105,667 and U.S. Patent No. 4,239,850), and acyl phosphates. Sphinx oxide compounds (Japanese Patent Publication No. 63-40799, Japanese Patent Publication No. 5-29234, Japanese Patent Publication No. 10-95788, Japanese Patent Publication No. 10-29997, Japanese Patent Publication No. 2001-233842, Japanese Patent Publication No. 2000-80068, Japanese Patent Publication No. 2006-342166, Japanese Patent Publication No. 2013-114249, Japanese Patent Publication No. 2014 Examples include (as described in Japanese Patent Publication No. 137466, Japanese Patent No. 4223071, Japanese Unexamined Patent Publication No. 2010-262028, and Japanese Patent Publication No. 2014-500852), oxime compounds (as described in Japanese Unexamined Patent Publication No. 2000-66385 and Japanese Patent No. 4454067), and oxadiazole compounds (as described in U.S. Patent No. 4,212,970). For example, paragraphs 0500 to 0547 of Japanese Unexamined Patent Publication No. 2012-208494 can also be considered.

[0072] It is also preferable to use acylphosphine oxide compounds or oxime compounds as polymerization initiators. As an acylphosphine oxide compound, for example, the commercially available IRGACURE 810 (compound name: bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide) manufactured by BASF Japan Ltd. can be used. As an oxime compound, commercially available products such as IRGACURE OXE01 (manufactured by BASF), IRGACURE OXE02 (manufactured by BASF), TR-PBG-304 (manufactured by Changzhou Strong Electronic New Materials Co., Ltd.), ADEKA Arculus NCI-831, ADEKA Arculus NCI-930 (manufactured by ADEKA), and ADEKA Arculus NCI-831 (manufactured by ADEKA) can be used. A single polymerization initiator may be used, or two or more may be used in combination. The content of the photopolymerization initiator in the liquid crystal composition is preferably 0.1 to 20% by mass, and more preferably 0.5 to 5% by mass, relative to the content of the polymerizable liquid crystal compound.

[0073] (Crosslinking agent) The liquid crystal composition may optionally contain a crosslinking agent to improve the film strength and durability after curing. Suitable crosslinking agents include those that cure with ultraviolet light, heat, or moisture. There are no particular restrictions on the crosslinking agent, and it can be appropriately selected depending on the purpose. Examples of crosslinking agents include polyfunctional acrylate compounds such as trimethylolpropane tri(meth)acrylate and pentaerythritol tri(meth)acrylate; epoxy compounds such as glycidyl(meth)acrylate and ethylene glycol diglycidyl ether; aziridine compounds such as 2,2-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate] and 4,4-bis(ethyleneiminocarbonylamino)diphenylmethane; isocyanate compounds such as hexamethylene diisocyanate and biuret-type isocyanate; polyoxazoline compounds having an oxazoline group in the side chain; and alkoxysilane compounds such as vinyltrimethoxysilane and N-(2-aminoethyl)3-aminopropyltrimethoxysilane. In addition, known catalysts can be used depending on the reactivity of the crosslinking agent, which can improve productivity in addition to improving film strength and durability. These may be used individually or in combination of two or more. The crosslinking agent content is preferably 3 to 20% by mass, and more preferably 5 to 15% by mass. By setting the crosslinking agent content to 3% by mass or more, the effect of improving crosslink density can be obtained, and by setting the crosslinking agent content to 20% by mass or less, a decrease in the stability of the cholesteric liquid crystal layer can be prevented. Note that "(meth)acrylate" is used to mean "either acrylate or methacrylate, or both."

[0074] (Orientation control agent) An orientation control agent may be added to the liquid crystal composition to contribute to the stable or rapid formation of a planar-oriented cholesteric liquid crystal layer. Examples of orientation control agents include fluorine (meth)acrylate polymers described in paragraphs

[0018] to

[0043] of Japanese Patent Application Publication No. 2007-272185, compounds represented by formulas (I) to (IV) described in paragraphs

[0031] to

[0034] of Japanese Patent Application Publication No. 2012-203237, and compounds described in Japanese Patent Application Publication No. 2013-113913. Furthermore, one type of orientation control agent may be used alone, or two or more types may be used in combination.

[0075] The amount of orientation control agent added to the liquid crystal composition is preferably 0.01 to 10% by mass, more preferably 0.01 to 5% by mass, and particularly preferably 0.02 to 1% by mass, relative to the total mass of the polymerizable liquid crystal compound.

[0076] (Other additives) In addition, the liquid crystal composition may contain at least one additive selected from various additives such as surfactants for adjusting the surface tension and uniform thickness of the coating film, and polymerizable monomers. Furthermore, polymerization inhibitors, antioxidants, ultraviolet absorbers, light stabilizers, colorants, and metal oxide fine particles may be added to the liquid crystal composition as needed, within limits that do not degrade the optical performance.

[0077] A cholesteric liquid crystal layer can be formed by applying a liquid crystal composition, obtained by dissolving a polymerizable liquid crystal compound, a polymerization initiator, and optionally added chiral agents, surfactants, etc., in a solvent to the surface on which the cholesteric liquid crystal layer is formed, drying it to obtain a coating film, and then irradiating this coating film with active light to polymerize the cholesteric liquid crystal composition, thereby forming a cholesteric liquid crystal layer with fixed cholesteric regularity. Furthermore, a laminated film consisting of multiple cholesteric liquid crystal layers can be formed by repeatedly performing the above-described manufacturing process for the cholesteric liquid crystal layer.

[0078] (solvent) There are no particular restrictions on the solvent used in preparing the liquid crystal composition, and it can be appropriately selected depending on the purpose, but organic solvents are preferably used. There are no particular restrictions on the organic solvent, and it can be appropriately selected depending on the purpose. Examples include ketones, alkyl halides, amides, sulfoxides, heterocyclic compounds, hydrocarbons, esters, and ethers. These may be used individually or in combination of two or more. Among these, ketones are particularly preferred when considering the environmental impact.

[0079] (Coating, orientation, polymerization) There are no particular restrictions on the coating method for the liquid crystal composition, and it can be appropriately selected depending on the purpose. Examples of coating methods include wire bar coating, curtain coating, extrusion coating, direct gravure coating, reverse gravure coating, die coating, spin coating, dip coating, spray coating, and slide coating. Alternatively, the coating can be applied to a support separately and then transferred. The liquid crystal molecules are oriented by heating the coated liquid crystal composition. The heating temperature is preferably 200°C or lower, and more preferably 130°C or lower. This orientation treatment yields an optical thin film in which the polymerizable liquid crystal compound is twisted and oriented so that it has a helical axis substantially perpendicular to the film surface.

[0080] The liquid crystal composition can be cured by further polymerizing the oriented liquid crystal compound. Polymerization may be carried out by thermal polymerization or photopolymerization using light irradiation, but photopolymerization is preferred. For light irradiation, ultraviolet light is preferred.

[0081] A first adhesive layer 50 is provided on the upper surface of the third functional layer 42BG in the diagram. As described above, as an example of a method for manufacturing the reflective film 30 shown in Figure 1, a laminate having a surface anti-reflective layer 32, a first support 34, a first phase difference layer 36, a first functional layer 38IR, a second functional layer 40R, and a third functional layer 42BG, and a laminate having a fourth functional layer 52IR, a fifth functional layer 54R, a sixth functional layer 56BG, a second phase difference layer 58, and a second support 60 are fabricated, and after bonding the two with a first adhesive layer 50, a second adhesive layer 62 is provided on the second support 60. The first adhesive layer 50 is a layer for bonding the two laminates in this manufacturing method.

[0082] There are no restrictions on the first adhesive layer 50; any known adhesive (bonding agent, tack) can be used as long as it has sufficient transparency (visible light transmittance) to visible light.

[0083] As an example, a heat-seal layer is preferably exemplified as the first adhesive layer 50. The heat seal layer contains a thermoplastic resin. Preferably, the thermoplastic resin is an amorphous resin. Such thermoplastic resins can be selected from the group consisting of polyvinyl acetal resins, such as polyvinyl butyral (PVB) resin, ethylene-vinyl acetate copolymers, and chlorine-containing resins. The main component of the heat seal layer is preferably one of the above-mentioned resins. The main component refers to a component that accounts for 50% or more by mass of the total mass of the heat seal layer. Among the resins mentioned above, polyvinyl acetal resins, such as polyvinyl butyral resin, and ethylene-vinyl acetate copolymers are preferred examples, with polyvinyl acetal resins (also called alkylacetalized polyvinyl alcohol), such as polyvinyl butyral resin, being more preferred. The resin is preferably a synthetic resin.

[0084] Furthermore, OCA (Optical Clear Adhesive) can also be suitably used as the first adhesive layer 50. For OCA, commercially available products for image display devices, especially those for the surface of the image display unit of an image display device, can be used. Examples of commercially available OCAs include adhesive sheets from Panac Corporation (such as PD-S1) and adhesive sheets from Nichiei Kako Co., Ltd.'s MHM series.

[0085] There are no restrictions on the thickness of the first adhesive layer 50; the thickness that provides the required adhesive strength can be appropriately set according to the material used to form the first adhesive layer 50.

[0086] On the upper surface of the first adhesive layer 50 in the figure, the fourth functional layer 52IR, the fifth functional layer 54R, and the sixth functional layer 56BG are provided in this order. Figure 3 shows enlarged views of the fourth functional layer 52IR, the fifth functional layer 54R, and the sixth functional layer 56BG. In the illustrated example of the reflective film 30, the fourth functional layer 52IR has a visible light reflective layer 52h and a visible light transmitting layer 52t. The fifth functional layer 54R has a visible light reflective layer 54h and a visible light transmitting layer 54t. Furthermore, the sixth functional layer 56BG has a visible light reflective layer 56h and a visible light transmitting layer 56t.

[0087] The visible light reflective layer 52h of the fourth functional layer 52IR is similar to the first functional layer 38IR described above, and as an example, it is a cholesteric liquid crystal layer having a selective reflection center wavelength in the infrared wavelength range. The visible light reflective layer 54h of the fifth functional layer 54R is similar to the second functional layer 40R described above, and as an example, it is a cholesteric liquid crystal layer having a selective reflection center wavelength in the red light wavelength range. Furthermore, the visible light reflective layer 56h of the sixth functional layer 56BG is similar to the third functional layer 42BG described above, and is, for example, a cholesteric liquid crystal layer having a selective reflection center wavelength in the wavelength range of green or blue light. The visible light reflective layers 52h, 54h, and 56h are all visible light reflective layers in the present invention. Furthermore, the visible light reflective layers 52h, 54h, and 56h are provided in the first region F of the reflective film 30.

[0088] It is preferable that the visible light reflective layers 52h of the first functional layer 38IR and the fourth functional layer 52IR have the same selective reflection center wavelength. It is preferable that the visible light reflective layers 54h of the second functional layer 40R and the fifth functional layer 54R have the same selective reflection center wavelength. Furthermore, it is preferable that the visible light reflective layers 56h of the third functional layer 42BG and the sixth functional layer 56BG have the same selective reflection center wavelength. In this invention, the same selective reflection center wavelength does not need to be exactly the same wavelength, and includes an unavoidable error range. Specifically, the same selective reflection center wavelength means that the difference in selective reflection center wavelengths is ±20 nm or less, preferably ±10 nm or less, and more preferably ±5 nm or less. In this regard, the reflective film shown in Figure 6, which will be discussed later, is also similar.

[0089] On the other hand, the visible light transmitting layer 52t of the fourth functional layer 52IR, the visible light transmitting layer 54t of the fifth functional layer 54R, and the visible light transmitting layer 56t of the sixth functional layer 56BG are all cholesteric liquid crystal layers or isotropic layers that selectively reflect ultraviolet light. Therefore, the visible light transmitting layer 52t, the visible light transmitting layer 54t, and the visible light transmitting layer 56t all transmit visible light. Furthermore, the visible light transmitting layer 52t, the visible light transmitting layer 54t, and the visible light transmitting layer 56t are all provided in the second region S of the reflective film 30.

[0090] Therefore, in the reflective film 30, the total thickness of the visible light reflective layer in the first region F is greater than the total thickness of the visible light reflective layer in the second region S. As a result, the reflective film 30 of the present invention provides excellent visibility of the projected image of the HUD displayed in the light-shielding region 26 of the windshield glass 14, while ensuring sufficient transmission of visible light in the transparent region of the windshield glass 14, as described above.

[0091] Figure 4 conceptually shows an example of a method for forming the fourth functional layer 52IR, the fifth functional layer 54R, and the sixth functional layer 56BG. This example describes a method for forming the fourth functional layer 52IR, the fifth functional layer 54R, and the sixth functional layer 56BG when the visible light transmitting layer 52t, the visible light transmitting layer 54t, and the visible light transmitting layer 56t are cholesteric liquid crystal layers that selectively reflect ultraviolet light. First, as shown on the left side of Figure 4, a laminate 70 is prepared in which a second phase difference layer 58 is formed on the surface of a second support 60, and a mask film 72 is prepared in which a mask 76 (area indicated by hatching) that blocks ultraviolet light in the area corresponding to the second region S is provided on the substrate 74. Next, as shown second from the left in Figure 4, the second support 60 and the substrate 74 are placed facing each other, and the laminate 70 and the mask film 72 are laminated. A liquid crystal composition 80 that forms a cholesteric liquid crystal layer that selectively reflects ultraviolet light is applied to the second phase difference layer 58 and dried. In this state, the liquid crystal composition 80 is exposed to ultraviolet light through the mask film 72 in air. As a result, as shown in the third image from the left in Figure 4, in the region exposed to ultraviolet light indicated by the thick line, the chiral agent contained in the liquid crystal composition isomerizes, and this portion of the liquid crystal composition 80 becomes a liquid crystal composition that forms a cholesteric liquid crystal layer that selectively reflects visible light. Finally, as shown on the right side of Figure 4, the liquid crystal composition 80 is cured by irradiating it with ultraviolet light in a low-oxygen atmosphere such as a nitrogen atmosphere. This forms a functional layer having a visible light reflective layer 82 and a visible light transmitting layer 84 consisting of a cholesteric liquid crystal layer that selectively reflects ultraviolet light. By repeating this process, multiple visible light reflective layers and visible light transmitting layers can be provided, as shown in Figure 3.

[0092] Figure 5 conceptually shows another example of a method for forming the fourth functional layer 52IR, the fifth functional layer 54R, and the sixth functional layer 56BG. This example describes a method for forming the fourth functional layer 52IR, the fifth functional layer 54R, and the sixth functional layer 56BG when the visible light transmitting layer 52t, the visible light transmitting layer 54t, and the visible light transmitting layer 56t are isotropic layers. First, similar to the example shown in Figure 4, a laminate 70 is prepared in which a second phase difference layer 58 is formed on the surface of a second support 60, and a mask film 72 is prepared in which a mask 76 (area indicated by hatching) that blocks ultraviolet light is provided in the area corresponding to the second area S of the substrate 74. Next, as shown second from the left in Figure 5, the second support 60 and the substrate 74 are placed facing each other, the laminate 70 and the mask film 72 are laminated, and a liquid crystal composition 86 that forms a cholesteric liquid crystal layer having a desired selective reflection center wavelength is applied to the second phase difference layer 58 and dried. In this state, the liquid crystal composition 86 is exposed to ultraviolet light through the mask film 72 in the air. As a result, as shown in the third image from the left in Figure 5, the liquid crystal composition 86 hardens in the areas exposed to ultraviolet light, indicated by the thick lines, while the areas shielded from ultraviolet light remain as liquid crystal composition. Finally, as shown on the right side of Figure 5, the liquid crystal composition 86 is heated to a temperature above the iso point where the liquid crystal compound becomes isotropic in a low-oxygen atmosphere such as a nitrogen atmosphere, and cured by irradiating the liquid crystal composition 86 with ultraviolet light. This makes it possible to form a functional layer having a visible light reflective layer 82 and a visible light transmitting layer 84 made of an isotropic layer. By repeating this process, multiple visible light reflective layers and visible light transmitting layers can be provided, as shown in Figure 3.

[0093] In the reflective film of the present invention, there are no restrictions on the thickness of the functional layer, and it may be set appropriately according to the desired selective reflection center wavelength, etc.

[0094] A second phase difference layer 58 is provided on the upper surface of the sixth functional layer 56BG in the diagram. The second phase difference layer 58 is similar to the first phase difference layer 36, but it allows S-polarized light that penetrates through the windshield glass 14 to pass through as S-polarized light, thereby enabling proper blocking of S-polarized light by polarized sunglasses.

[0095] Of the light that enters through the windshield when driving a car, the light that drivers find most dazzling is often S-polarized light. Therefore, polarized sunglasses are designed to block S-polarized light. Here, the reflective film of the present invention has a visible light reflective layer that selectively reflects light in a specific wavelength range. In the illustrated example, the reflective film 30 uses a cholesteric liquid crystal layer as the visible light reflective layer in a preferred embodiment. However, when S-polarized light that has entered from the outside through the windshield glass passes through the cholesteric liquid crystal layer, its polarization state changes, and the S-polarized light becomes, for example, elliptical polarization and / or linear polarization with a different polarization direction. Even if such elliptical polarization passes through the first phase difference layer 36, it does not revert to S polarization; in other words, it becomes polarization that cannot be blocked by polarized sunglasses.

[0096] In contrast, the reflective film 30 in the illustrated example, in a preferred embodiment, has a second phase difference layer 58 on the upper surface of the sixth functional layer 56BG in the figure, that is, on the side opposite to the first phase difference layer 36 of the functional layer. The second phase difference layer 58 exhibits the following effects. For example, if the HUD projector emits P-polarized projection light, by providing such a second phase difference layer 58, the S-polarized light incident from the outside through the windshield glass is converted into circularly polarized light in a direction that is not selectively reflected by the cholesteric liquid crystal layer acting as a visible light reflecting layer. This allows the circularly polarized light to pass through the cholesteric liquid crystal layer acting as a visible light reflecting layer. As a result, the circularly polarized light converted from S-polarized light can be converted back to S-polarized light by the first phase difference layer 36. As a result, S-polarized light incident from the outside can be properly blocked by polarized sunglasses worn by the driver. In other words, by having a second phase difference layer 58 in the reflective film 30, the reflective film 30 can be made into a reflective film for HUDs that is suitable for use with polarized sunglasses.

[0097] Various types of the second phase difference layer 58 can be used, similar to the first phase difference layer 36 described above. Furthermore, as the second phase difference layer 58, a liquid crystal layer in which a helical orientation structure of a liquid crystal compound that is twisted along a helical axis extending in the thickness direction is also suitably used. Hereinafter, this liquid crystal layer will also be referred to as the "twist layer" for convenience. Preferably, the twisted layer has a helical pitch P equivalent to that of a cholesteric liquid crystal layer whose selective reflection center wavelength is in the infrared region, and a small number of helical orientation structure pitches. Such a twisted layer exhibits optical activity and birefringence with respect to visible light, which has a shorter wavelength than infrared light, and thus more favorably exhibits the effects on S-polarization described above. Specifically, when the number of helical orientation structure pitches of the twisted layer is x and the thickness of the twisted layer is y [μm], it is preferable that the conditions '0.1 ≤ x ≤ 1.0' and '0.5 ≤ y ≤ 3.0' are satisfied.

[0098] There are no restrictions on the in-plane retardation Re(550) of the second phase difference layer 58; it can be set appropriately according to the phase difference required for the second phase difference layer 58. Specifically, the in-plane retardation Re(550) of the second phase difference layer 58 is preferably 150 to 400 nm, more preferably 200 to 340 nm, and even more preferably 220 to 300 nm.

[0099] A second support 60 is provided on the upper surface of the second phase difference layer 58 in the figure. As described above, the reflective film 30 shown in Figure 2 is, for example, produced by creating a laminate having a surface anti-reflective layer 32, a first support 34, a first phase difference layer 36, a first functional layer 38IR, a second functional layer 40R, and a third functional layer 42BG, and a laminate having a fourth functional layer 52IR, a fifth functional layer 54R, a sixth functional layer 56BG, a second phase difference layer 58, and a second support 60, and then bonding the two together with a first adhesive layer 50. The second support 60 is primarily for supporting the fourth functional layer 52IR, the fifth functional layer 54R, the sixth functional layer 56BG, and the second phase difference layer 58 in the latter laminate. The second support 60 can be the same as the first support 34 described above.

[0100] A second adhesive layer 62 is provided on the upper surface of the second support 60 in the figure. The second adhesive layer 62 is for attaching the reflective film 30 to the inner glass panel 18 of the windshield glass. The second adhesive layer 62 can be the same as the first adhesive layer 50 described above.

[0101] The reflective film of the present invention will be described in more detail below by explaining the function of the reflective film 30 shown in Figure 2. As an example, the projector 12 emits a P-polarized projection image (projected light). The projection image (P-polarized light) emitted by the projector passes through the surface anti-reflective layer 32 and the first support 34 and is converted by the first phase difference layer 36 into circularly polarized light that is selectively reflected by the cholesteric liquid crystal layers constituting the first functional layer 38IR, the second functional layer 40R and the third functional layer 42BG, as well as the fourth functional layer 52IR, the fifth functional layer 54R and the sixth functional layer 56BG.

[0102] The projected image, converted to circular polarization, is sequentially incident on the first functional layer 38IR, the second functional layer 40R, and the third functional layer 42BG. A portion of the light in the wavelength range reflected by the visible light reflective layer of each functional layer is reflected and observed by the driver U as a projected image.

[0103] Meanwhile, the circularly polarized projected light that has passed through the first functional layer 38IR, the second functional layer 40R, and the third functional layer 42BG further passes through the first adhesive layer 50 and is sequentially incident on the fourth functional layer 52IR, the fifth functional layer 54R, and the sixth functional layer 56BG. Here, circularly polarized light incident on the first region F corresponding to the light-shielding region 26 of the windshield glass is sequentially incident on the visible light reflective layer 52h of the fourth functional layer 52IR, the visible light reflective layer 54h of the fifth functional layer 54R, and the visible light reflective layer 56h of the sixth functional layer 56BG. A portion of the light in the wavelength range reflected by the visible light reflective layer of each functional layer is reflected and observed by the driver U as a projected image. On the other hand, circularly polarized light incident on the second region S, which corresponds to the transmission region of the windshield glass, sequentially passes through the visible light transmission layer 52t of the fourth functional layer 52IR, the visible light transmission layer 54t of the fifth functional layer 54R, and the visible light transmission layer 56t of the sixth functional layer 56BG, and then passes through the reflective film 30.

[0104] The circularly polarized light reflected by the visible light reflective layers of the first functional layer 38IR, the second functional layer 40R, and the third functional layer 42BG, as well as the fourth functional layer 52IR, the fifth functional layer 54R, and the sixth functional layer 56BG, is again incident on the first phase difference layer 36, converted back into the original linearly polarized light, such as P-polarized light, and emitted, and observed by the driver or others as the projected light of the HUD.

[0105] As described above, in the reflective film 30, in the first region F, the incident projected light is reflected by the visible light reflective layers, namely the first functional layer 38IR, the second functional layer 40R, and the third functional layer 42BG, and further reflected by the visible light reflective layers of the fourth functional layer 52IR, the fifth functional layer 54R, and the sixth functional layer 56BG. On the other hand, in the second region S, the incident projected light is reflected only by the visible light reflective layers: the first functional layer 38IR, the second functional layer 40R, and the third functional layer 42BG. In other words, in the reflective film of the present invention, the total thickness of the visible light reflective layer in the first region F is greater than the total thickness of the visible light reflective layer in the second region. Therefore, in the reflective film of the present invention, the visible light reflectance in the first region F is higher than that in the second region S.

[0106] As described above, the first region F corresponds to the light-blocking region 26 of the windshield glass, and the second region S corresponds to the light-transmitting region of the windshield glass. In automobiles, the outside of the vehicle is not observed through the light-blocking region 26 of the windshield glass, so there is no need to transmit visible light. On the other hand, the light-transmitting region of the windshield glass needs to transmit enough visible light in order to ensure forward visibility. In contrast, the reflective film 30 of the present invention allows for the projection of a highly visible HUD image by increasing the total thickness of the visible light reflective layer in the first region F, which corresponds to the light-shielding region 26 of the windshield glass, thereby increasing the reflectivity. Furthermore, in the second region S, which corresponds to the transmission region where visible light transmittance is required, the total thickness of the visible light reflective layer is thinner than in the first region, thus ensuring good visible light transmittance.

[0107] Figure 6 shows an example of another embodiment of the reflective film of the present invention. Note that the reflective film 90 shown in Figure 6 uses many of the same components as the reflective film 30 shown in Figure 2, so the same components are given the same reference numerals, and the following explanation will mainly focus on the different parts.

[0108] As shown in Figure 6, the reflective film 90 has, from the bottom in the figure, a surface anti-reflective layer 32, a first support 34, a first phase difference layer 36, a first functional layer 92IR, a second functional layer 94R, a third functional layer 96BG, a second phase difference layer 58, and a second adhesive layer 62. Here, the surface anti-reflective layer 32, the first support 34, the first phase difference layer 36, the second phase difference layer 58, and the second adhesive layer 62 are the same as those of the reflective film 30 shown in Figure 2 above. However, as shown in Figure 6, the reflective film 90 does not have the first adhesive layer 50 and the second support 60.

[0109] In the reflective film 90, the first functional layer 92IR has a different layer structure in the first region F, which corresponds to the light-shielding region 26 of the windshield glass, and the second region S, which corresponds to the light-transmitting region of the windshield glass. Specifically, the first region F is composed of a single visible light reflective layer 92a, and the second region S has a structure in which a visible light reflective layer 92h and a visible light transmitting layer 92t are laminated. The thickness of the first functional layer 92IR is the same in the first and second regions. Therefore, the visible light reflective layer 92a of the first region F is thicker than the visible light reflective layer 92h of the second region S. The visible light reflective layer 92a and the visible light reflective layer 92h are integrally formed and, like the first functional layer 38IR in the reflective film 30, are visible light reflective layers consisting of a cholesteric liquid crystal layer having a selective reflection center wavelength in the infrared wavelength range. The visible light reflective layer 92a and the visible light reflective layer 92h have the same selective reflection center wavelength. On the other hand, the visible light transmitting layer 92t is the same as the visible light transmitting layer 52t of the fourth functional layer 52IR in the reflective film 30, and is a cholesteric liquid crystal layer or isotropic layer that selectively reflects ultraviolet light.

[0110] Similarly, the second functional layer 94R also has a different layer structure in the first region F, which corresponds to the light-shielding region 26 of the windshield glass, and the second region S, which corresponds to the light-transmitting region of the windshield glass. Specifically, the first region F is composed of a single visible light reflective layer 94a, and the second region S has a structure in which a visible light reflective layer 94h and a visible light transmitting layer 94t are laminated. The thickness of the second functional layer 94R is the same in the first and second regions. Therefore, the visible light reflective layer 94a of the first region F is thicker than the visible light reflective layer 94h of the second region S. The visible light reflective layer 94a and the visible light reflective layer 94h are integrally formed and, like the second functional layer 40R in the reflective film 30, are visible light reflective layers consisting of a cholesteric liquid crystal layer having a selective reflection center wavelength in the red light wavelength range. The visible light reflective layer 94a and the visible light reflective layer 94h have the same selective reflection center wavelength. On the other hand, the visible light transmitting layer 94t is the same as the visible light transmitting layer 54t of the fifth functional layer 54R in the reflective film 30, and is a cholesteric liquid crystal layer or isotropic layer that selectively reflects ultraviolet light.

[0111] Furthermore, the third functional layer 96BG also has a different layer structure in the first region F, which corresponds to the light-shielding region 26 of the windshield glass, and the second region S, which corresponds to the light-transmitting region of the windshield glass. Specifically, the first region F is composed of a single visible light reflective layer 96a, and the second region S has a structure in which a visible light reflective layer 96h and a visible light transmitting layer 96t are laminated. The thickness of the third functional layer 96BG is the same in the first and second regions. Therefore, the visible light reflective layer 96a of the first region F is thicker than the visible light reflective layer 96h of the second region S. The visible light reflective layers 96a and 96h are integrally formed and, like the third functional layer 42BG in the reflective film 30, are visible light reflective layers consisting of a cholesteric liquid crystal layer having a selective reflection center wavelength in the blue or green light wavelength range. The visible light reflective layers 96a and 96h have the same selective reflection center wavelength. On the other hand, the visible light transmitting layer 96t is the same as the visible light transmitting layer 56t of the sixth functional layer 56BG in the reflective film 30, and is a cholesteric liquid crystal layer or isotropic layer that selectively reflects ultraviolet light.

[0112] As described above, in the reflective film 90 as well, the total thickness of the visible light reflective layer in the first region F, which corresponds to the light-shielding region 26 of the windshield glass, is greater than that of the second region S, which corresponds to the light-transmitting region of the windshield glass. In other words, of the projected light incident on the reflective film 90, the projected light incident on the first region F is reflected with high reflectivity by the thicker visible light reflective layers 92a, 94a, and 96a, with a portion of the light having wavelengths corresponding to the selective reflection wavelengths of each reflective layer. In contrast, when projected light is incident on the second region S, a portion of the light corresponding to the selective reflection wavelength of each reflective layer is reflected with a lower reflectivity than in the first region F by the thin visible light reflective layers 92h, 94h, and 96h. Therefore, the reflective film 90 shown in Figure 6 exhibits the same effects as the reflective film 30 described above. Specifically, in the reflective film 90, the first region F corresponding to the light-shielding region 26 of the windshield glass has a thicker total thickness of the visible light reflective layer, thereby increasing the reflectivity and allowing for the projection of a highly visible HUD image. Furthermore, in the second region S corresponding to the transmission region where visible light transmittance is required, the total thickness of the visible light reflective layer is thinner than in the first region, ensuring good visible light transmittance.

[0113] The first functional layer 92IR, the second functional layer 94R, and the third functional layer 96BG can be formed as follows, for example. This example describes a method for forming the first functional layer 92IR, the second functional layer 94R, and the third functional layer 96BG when the visible light transmitting layer 92t, the visible light transmitting layer 94t, and the visible light transmitting layer 96t are cholesteric liquid crystal layers that selectively reflect ultraviolet light.

[0114] A mask that blocks ultraviolet light in the region corresponding to the first region F is provided on one surface of the substrate forming the functional layer. Furthermore, a liquid crystal composition that forms a cholesteric liquid crystal layer that selectively reflects visible light in the target wavelength range is applied to the opposite surface of the substrate and dried. The coated liquid crystal composition is irradiated with ultraviolet light through a mask in the air. As a result of this ultraviolet irradiation, the area covered by the mask (first region F) remains unchanged, but in the area not covered by the mask (second region S), the side of the substrate not in contact with air partially hardens and becomes a cholesteric liquid crystal layer that reflects visible light, while the liquid crystal composition on the side in contact with air undergoes isomerization of the chiral agent, transforming into a liquid crystal composition that forms a cholesteric liquid crystal layer having a selective reflection center wavelength in the ultraviolet wavelength range. Next, without using a mask, the entire surface of the liquid crystal composition is irradiated with ultraviolet light in a low-oxygen atmosphere such as a nitrogen atmosphere to cure the liquid crystal composition. As a result, the first region corresponding to the light-shielding region 26 is a single cholesteric liquid crystal layer that selectively reflects visible light, and the second region corresponding to the transmission region is a reflective layer in which a cholesteric liquid crystal layer that selectively reflects visible light and a cholesteric liquid crystal layer that selectively reflects ultraviolet light are laminated. By repeating this process, multiple reflective layers with the above configuration, as shown in Figure 6, can be provided.

[0115] The visible light transmitting layers 92t, 94t, and 96t, and the first functional layer 92IR, second functional layer 94R, and third functional layer 96BG, which are isotropic layers, may be formed as follows, for example.

[0116] A mask that semi-transmits ultraviolet light in a region corresponding to the second region S is provided on one surface of the substrate forming the functional layer. Furthermore, a liquid crystal composition that forms a cholesteric liquid crystal layer selectively reflecting visible light in the target wavelength range is applied to the opposite surface of the substrate and dried. The coated liquid crystal composition is irradiated with ultraviolet light through a mask in the air. This ultraviolet irradiation causes the liquid crystal composition in the first region F, which is not covered by the mask, to harden and become a cholesteric liquid crystal layer that reflects visible light. On the other hand, in the region covered by the mask (second region S), due to the partial transmission of ultraviolet light, the side of the substrate not in contact with the air partially hardens and becomes a cholesteric liquid crystal layer that reflects visible light, but the liquid crystal composition on the side in contact with the air remains unchanged. Subsequently, the liquid crystal composition is heated to a temperature above the iso point where the liquid crystal compound becomes isotropic, while the entire surface (or only the second region S) is irradiated with ultraviolet light to cure the second region S. As a result, the first region F corresponding to the light-shielding region 26 is a single cholesteric liquid crystal layer that selectively reflects visible light, and the second region S corresponding to the transmission region is a reflective layer with a cholesteric liquid crystal layer that selectively reflects visible light and an isotropic layer stacked on top of each other. By repeating this process, multiple reflective layers with the above configuration, as shown in Figure 6, can be provided.

[0117] As described above, the reflective film of the present invention has a functional layer including a visible light reflective layer, and has a first region and a second region in the in-plane direction. In this case, it is preferable that the reflective film of the present invention has a constant luminous efficiency correction reflectance in the first and second regions, and a constant thickness of the visible light reflective layer (total thickness) in the first and second regions. Having such a configuration is preferable in that it reduces the likelihood of display inconsistencies.

[0118] Here, a constant luminous efficiency-corrected reflectance means that the variation in the luminous efficiency-corrected reflectance in the first and second regions is within ±1%. The variation in the luminous efficiency-corrected reflectance is confirmed by measuring the reflectance at 10 or more arbitrary points in a plane with an aperture size of 1 mm or larger in diameter. The method for measuring the luminous efficiency-corrected reflectance is shown below. Furthermore, a constant visible light reflective layer thickness means that the variation in the total thickness of all visible light reflective layers in the first and second regions is within ±5%. The variation in the visible light reflective layer thickness is confirmed by measuring the thickness at 20 or more arbitrary points in a plane with an aperture size of 1 mm or larger in diameter. The measurement of the visible light reflective layer thickness can be performed in the same manner as in the examples described later.

[0119] [Measurement of luminous efficiency-corrected reflectance] Laminated glass is prepared by attaching the reflective film of the present invention to its surface. Natural light is incident on this laminated glass from the reflective film side at a direction of 5° with respect to the normal direction of the laminated glass, and the reflection spectrum is measured using a spectrophotometer (JASCO Corporation, V-670). In accordance with JIS R3106, the reflectance is calculated by multiplying the reflectance by a coefficient corresponding to the luminous efficiency and the emission spectrum of the D65 light source at wavelengths of 10 nm increments from 380 to 780 nm, and this is defined as the luminous efficiency-corrected reflectance.

[0120] In the examples shown in Figures 2 and 6, although not shown, the reflective film of the present invention may have an alignment film for aligning the cholesteric liquid crystal layer which becomes the visible light reflective layer. Various known alignment films used in the formation of liquid crystal layers can be used as alignment films. For example, alignment films can be formed by rubbing a layer made of organic compounds such as polymers (resins such as polyimide, polyvinyl alcohol, polyester, polyarylate, polyamideimide, polyetherimide, polyamide, and modified polyamide), oblique deposition of inorganic compounds, formation of a layer having microgrooves, and accumulation of organic compounds (e.g., ω-tricosanoic acid, dioctadecylmethylammonium chloride, and methyl stearylate) using the Langmuir-Bludget method (LB film). Furthermore, an orientation film may be used in which the orientation function is generated by applying an electric field, a magnetic field, or light irradiation. In particular, an orientation film in which the polymer layer that forms the orientation film has been subjected to a rubbing treatment is a preferred example. The rubbing treatment can be carried out using known methods, and as an example, it can be performed by rubbing the surface of the polymer layer in a certain direction with paper or cloth.

[0121] Although the reflective film, laminated glass, and image display system of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and various improvements and modifications may be made without departing from the spirit of the present invention. [Examples]

[0122] The present invention will be described in more detail below with reference to examples. The materials, reagents, amounts and proportions of substances, and procedures shown in the following examples, comparative examples, and preparation examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following examples and reference examples.

[0123] <Preparation of cellulose acylate film with orientation film> (Preparation of cellulose acylate film (resin substrate)) As the resin substrate, a 40 μm cellulose acylate film (TAC film) was prepared using the same manufacturing method as in Example 20 of International Publication No. 2014 / 112575.

[0124] (Saponification of cellulose acylate film) The prepared cellulose acylate film was passed through a dielectric heating roll at a temperature of 60°C to raise the film surface temperature to 40°C. Then, an alkaline solution with the composition shown below was applied to one side of the film using a bar coater at a rate of 14 mL / m². 2 The sample was applied and then left under a steam-type far-infrared heater (manufactured by Noritake Co., Limited) heated to 110°C for 10 seconds. Next, using the same bar coater, 3 mL / m² of pure water is applied to the film coated with the alkaline solution. 2 It was applied. Next, the film coated with pure water was subjected to three repeated rinses using a fountain coater and dewatering with an air knife. After that, the film was left in a 70°C drying zone for 5 seconds to dry, thereby producing saponified cellulose acylate film 1.

[0125] -------------------------------------------------- Composition of alkaline solution -------------------------------------------------- • Potassium hydroxide 4.7 parts by mass ·Water 15.7 parts by mass Isopropanol 64.8 parts by mass • Surfactants (C 16 H 33 O(CH2CH2O) 10 H) 1.0 parts by mass • Propylene glycol 14.9 parts by mass --------------------------------------------------

[0126] (Formation of orientation film) On the saponified surface of the saponified cellulose acylate film 1 obtained above, apply the orientation film-forming coating solution with the composition shown below using a wire bar coater at a rate of 24 mL / m². 2 The coating was applied and dried with 100°C hot air for 120 seconds to form a film. The prepared coating film was subjected to a rubbing treatment (rayon cloth, pressure: 0.1 kgf (0.98 N), rotation speed: 1000 rpm (revolutions per minute), transport speed: 10 m / min, number of passes: 1 back and forth) in a direction rotated 45° counterclockwise from the short side direction to form an oriented film. In this way, a cellulose acylate film with an orientation film was prepared.

[0127] -------------------------------------------------- Composition of coating solution for aligning film formation -------------------------------------------------- • 28 parts by mass of the modified polyvinyl alcohol shown below • Citrate ester (AS3, manufactured by Sankyo Chemical Co., Ltd.) 1.2 parts by mass • Photoinitiator (Irgacure 2959, manufactured by BASF) 0.84 parts by mass Glutaraldehyde 2.8 parts by mass ·Water 699 parts by mass • Methanol 226 parts by mass --------------------------------------------------

[0128] (Modified polyvinyl alcohol) The polymer has the following structure (in the formula, the numerical value listed for each repeating unit represents the content (mass %) of each repeat relative to the total number of repeating units). [ka]

[0129] <Preparation of various coating solutions used in the manufacture of reflective films> The components were mixed according to the formulations shown in Table 1 below, and the mixture was filtered through a polypropylene filter with a pore size of 10 μm to prepare various coating solutions used for the production of reflective films. The amounts of each component shown in Table 1 are expressed in parts by mass.

[0130] [Table 1]

[0131] In Table 1, the rod-shaped liquid crystal compound (A), monomer (A), chiral agent (A), chiral agent (B), and chiral agent (C), polymer (A), and orientation control agent 1 and orientation control agent 2 are the compounds shown below.

[0132] <Rod-shaped liquid crystal compound (A)> The rod-shaped liquid crystal compound (A) is a mixture of the following liquid crystal compounds. [ka]

[0133] <Monomer (A)> [ka]

[0134] <Chiral agent (A)> [ka] <Chiral agent (B)> [ka] <Chiral agent (C)> [ka]

[0135] <Polymer (A)> The polymer has the following structure (in the formula, the numerical values ​​listed for each repeating unit represent the content (mass %) of each repeating unit relative to the total number of repeating units).

[0136] [ka]

[0137] [ka] [ka]

[0138] [Example 1] As described above, the orientation film of the cellulose acylate film with the orientation film was subjected to a rubbing treatment (rayon cloth, pressure: 0.1 kgf (0.98 N), rotation speed: 1000 rpm, conveying speed: 10 m / min, number of passes: 1 back and forth) in a direction rotated 45° clockwise with respect to the long side direction of the resin substrate (cellulose acylate film). A coating solution, AIR, was applied to the rubbed orientation film surface using a wire bar at room temperature to form a coating film with a dry film thickness of 1.28 μm after drying. The film with the coating was heated at 60°C for 80 seconds. Subsequently, under air (oxygen concentration: approximately 20 vol%) at 40°C, the coating was irradiated with light from a 365nm LED lamp (manufactured by Acroedge Co., Ltd.) at a dose of 60 mJ / cm². 2 The light was irradiated using [a specific method / tool]. A 365nm LED lamp is an LED lamp that emits light with a central wavelength of 365nm. Furthermore, the resulting composition layer was heated at 60°C for 10 seconds. Subsequently, under a nitrogen atmosphere at 50°C, the composition layer was irradiated with light from a metal halide lamp (manufactured by iGraphics Co., Ltd.) (irradiation dose: 300 mJ / cm²). 2 By doing so, the orientation of the liquid crystal compound was fixed, and a liquid crystal layer AIR, consisting of a phase difference layer A1 and a cholesteric liquid crystal layer IR1, was formed on the alignment film in that order from the alignment film side. In other words, a cholesteric liquid crystal layer-equipped film AIR was formed by simultaneously forming a phase difference layer A1 (Re(550): 126 nm, film thickness: 0.85 μm) and a cholesteric liquid crystal layer IR1 (first functional layer, selective reflection center wavelength: 798 nm, film thickness: 0.43 μm) as a visible light reflective layer on an alignment film using the coating solution AIR.

[0139] Next, the coating solution RBG was applied to the surface of the cholesteric liquid crystal layer IR1 of the fabricated cholesteric liquid crystal layer-attached film AIR using a wire bar at room temperature so that the dry film thickness after drying was 0.84 μm, thereby forming a coating film. The film with the coating applied was heated at 60°C for 80 seconds. Subsequently, under air (oxygen concentration: approximately 20 vol%) at 40°C, the coating was irradiated with light from a 365nm LED lamp (manufactured by Acroedge Co., Ltd.) at a dose of 60 mJ / cm². 2 It was irradiated using [a specific method / tool]. Furthermore, the resulting composition layer was heated at 60°C for 10 seconds. Subsequently, under a nitrogen atmosphere at 50°C, the composition layer was irradiated with light from a metal halide lamp (manufactured by iGraphics Co., Ltd.) (irradiation dose: 300 mJ / cm²). 2 This fixed the orientation of the liquid crystal compound, and formed a liquid crystal layer RBG consisting of a cholesteric liquid crystal layer 2 and a cholesteric liquid crystal layer 3 on the liquid crystal layer AIR. In other words, a cholesteric liquid crystal layer-equipped film RBG was formed by simultaneously forming a cholesteric liquid crystal layer R1 (second functional layer, selective reflection center wavelength: 676 nm, film thickness: 0.54 μm) as a visible light reflective layer and a cholesteric liquid crystal layer BG1 (third functional layer, selective reflection center wavelength: 458 nm, film thickness: 0.30 μm) as a visible light reflective layer on the liquid crystal layer AIR using the coating solution RBG. In this way, a cholesteric liquid crystal layer film RBG was fabricated, which has a cholesteric liquid crystal layer having multiple regions with different helical pitches (selective reflection center wavelengths) along the thickness direction, namely a cholesteric liquid crystal layer IR1 in the liquid crystal layer AIR, and a cholesteric liquid crystal layer consisting of cholesteric liquid crystal layers R1 and BG1 in the liquid crystal layer RBG, forming a three-layer cholesteric liquid crystal layer.

[0140] As described above, the resin substrate with an orientation film (cellulose acylate film with orientation film) was cut to 400 mm in length and 300 mm in width, and the orientation film side of the resin substrate was rubbed (rayon cloth, pressure: 0.1 kgf (0.98 N), rotation speed: 1000 rpm, conveying speed: 10 m / min, number of times: 1 back and forth) in a direction rotated 15° clockwise from the long side of the resin substrate.

[0141] Coating solution A1 was applied to the rubbed orientation film surface using a wire bar at room temperature so that the dry film thickness after drying was 1.5 μm, thereby forming a coating film. The coating was dried at room temperature for 30 seconds, and then heated in a 60°C atmosphere for 1 minute. Subsequently, in an environment with an oxygen concentration of 1000 ppm or less, the coating film was irradiated with light from a metal halide lamp (manufactured by iGraphics Co., Ltd.) at 50°C (irradiation dose: 300 mJ / cm²). 2 By doing so, a phase difference layer A2 (Re(550): 265 nm, film thickness: 1.5 μm) was formed.

[0142] Next, coating solution BG1 was applied to the surface of the obtained phase difference layer A2 using a wire bar at room temperature to form a coating film with a dry film thickness of 0.30 μm after drying. After drying the coating film at room temperature for 30 seconds, it was heated in a 60°C atmosphere for 1 minute. Subsequently, under air (oxygen concentration: approximately 20 vol%) at 40°C, a 365nm LED lamp (manufactured by Acroedge Co., Ltd.) was used to illuminate the coating at an illuminance of 50 mW / cm². 2 , irradiation amount 60mJ / cm 2 The LED lamp was irradiated using black PET in a 400mm x 300mm resin substrate. Furthermore, the resulting composition layer was heated at 60°C for 10 seconds. Subsequently, in an environment with an oxygen concentration of 1000 ppm or less, the composition layer was irradiated with light from a metal halide lamp (manufactured by iGraphics Co., Ltd.) at 50°C (irradiation dose: 300 mJ / cm²). 2 )did. As a result, a cholesteric liquid crystal layer-attached film BGUV1 (sixth functional layer) was formed, having a reflective layer BG2 (visible light reflective layer (cholesteric liquid crystal layer), selective reflection center wavelength: 458 nm, film thickness: 0.30 μm, LED lamp transmission area) in a 400 mm x 300 mm area (first area), and an ultraviolet reflective layer UV1 (visible light transmission layer (cholesteric liquid crystal layer), selective reflection center wavelength: 320 nm, film thickness: 0.30 μm, LED lamp light shielding area).

[0143] Next, coating solution R1 was applied to the cholesteric liquid crystal layer side of the cholesteric liquid crystal layer-equipped film BGUV1 using a wire bar at room temperature to form a coating film such that the dry film thickness after drying was 0.54 μm. The coating was dried at room temperature for 30 seconds, and then heated in a 60°C atmosphere for 1 minute. Subsequently, under air (oxygen concentration: approximately 20 vol%) at 40°C, the coating was exposed to light from a 365nm LED lamp (manufactured by Acroedge Co., Ltd.) at an illuminance of 50 mWJ / cm². 2 , irradiation amount 60mJ / cm 2 The sample was irradiated using black PET. At this time, 400mm x 200mm of the 400mm x 300mm substrate was used to shield the LED lamp. In this case, the area shielded by the black PET overlapped with the UV1 ultraviolet reflective layer. Furthermore, the resulting composition layer was heated at 60°C for 10 seconds. Subsequently, in an environment with an oxygen concentration of 1000 ppm or less, the composition layer was irradiated with light from a metal halide lamp (manufactured by iGraphics Co., Ltd.) at 50°C (irradiation dose: 300 mJ / cm²). 2 )did. As a result, a cholesteric liquid crystal layer-attached film RUV1 (fifth functional layer) was formed, having a reflective layer R2 (visible light reflective layer (cholesteric liquid crystal layer), selective reflection center wavelength: 676 nm, film thickness: 0.54 μm, LED lamp transmission area) in a 400 mm x 300 mm area (first area), and an ultraviolet reflective layer UV2 (visible light transmission layer (cholesteric liquid crystal layer), selective reflection center wavelength: 320 nm, film thickness: 0.54 μm, LED lamp light shielding area).

[0144] Next, coating solution IR1 was applied to the cholesteric liquid crystal layer side of the cholesteric liquid crystal layer-equipped film RUV1 using a wire bar at room temperature to form a coating film such that the dry film thickness after drying was 0.43 μm. The coating was dried at room temperature for 30 seconds, and then heated in a 60°C atmosphere for 1 minute. Subsequently, under air (oxygen concentration: approximately 20 vol%) at 40°C, the coating was exposed to light from a 365nm LED lamp (manufactured by Acroedge Co., Ltd.) at an illuminance of 50 mWJ / cm². 2 , irradiation amount 60mJ / cm 2 The sample was irradiated using black PET. At this time, 400mm x 200mm of the 400mm x 300mm substrate was used to shield the LED lamp. In this case, the area shielded by the black PET overlapped with the UV2 ultraviolet reflective layer. Furthermore, the resulting composition layer was heated at 60°C for 10 seconds. Subsequently, in an environment with an oxygen concentration of 1000 ppm or less, the composition layer was irradiated with light from a metal halide lamp (manufactured by iGraphics Co., Ltd.) at 50°C (irradiation dose: 300 mJ / cm²). 2 )did. As a result, a cholesteric liquid crystal layer-attached film IRUV1 (fourth functional layer) was formed, having a reflective layer IR2 (visible light reflective layer (cholesteric liquid crystal layer), selective reflection center wavelength: 798 nm, film thickness: 0.43 μm, LED lamp transmission area) in a 400 mm x 300 mm area (first area), and an ultraviolet reflective layer UV3 (visible light transmission layer (cholesteric liquid crystal layer), selective reflection center wavelength: 320 nm, film thickness: 0.43 μm, LED lamp light shielding area).

[0145] As described above, an adhesive layer 1 (first adhesive layer) was formed on the reflective layer side of the cholesteric liquid crystal layer-attached film RGB. NCF-D692 (adhesive layer thickness 15 μm, manufactured by Lintec Corporation) was used for the adhesive layer. After peeling off the release film from the adhesive layer (NCF-D692), the exposed adhesive layer and the reflective layer of the cholesteric liquid crystal layer-equipped film RBG were brought into contact and bonded together with a rubber roller under a load of 2 kg, thereby producing a reflective film 1 having the following configuration: alignment film-equipped cellulose acylate film 1 / phase difference layer A1 / reflective layer 1 / adhesive layer 1 / protective film 1. Furthermore, the NCF-D692 mentioned above has a light release film, an adhesive layer, and a heavy release film, and the protective film in the reflective film corresponds to the heavy release film of the NCF-D692. Furthermore, after peeling off the protective film of the fabricated reflective film 1, the exposed adhesive layer and the reflective layer of the cholesteric liquid crystal layer-equipped film IRUV1 were brought into contact and bonded together with a rubber roller under a load of 2 kg, thereby producing a reflective film 2 having the following configuration: alignment-equipped cellulose acylate film 1 / phase difference layer A1 / reflective layer 1 / adhesive layer 1 / reflective layer 2 + ultraviolet reflective layer / phase difference layer A2 / alignment-equipped cellulose acylate film 2.

[0146] An adhesive layer (second adhesive layer) was formed on the cellulose acylate film 2 side of the reflective film 2 prepared as described above, with the orientation film attached. NCF-D692 (adhesive layer thickness 15 μm, manufactured by Lintec Corporation) was used for the adhesive layer. After peeling off the light release film of the adhesive layer (NCF-D692), the exposed adhesive layer and the cellulose acylate film 2 with alignment film of the reflective film 2 were brought into contact and bonded together with a rubber roller under a load of 2 kg, thereby producing a reflective film 3 having the following structure: cellulose acylate film 1 with alignment film / phase difference layer A1 / reflective layer 1 / adhesive layer 1 / reflective layer 2 + ultraviolet reflective layer / cellulose acylate film 2 with alignment film / phase difference layer A2 / adhesive layer 2 / protective film 2 (heavy release film).

[0147] <Fabrication of glass with a light-blocking layer> A flat glass substrate (first glass substrate) measuring 300 mm in length x 300 mm in width and 2 mm in thickness was screen printed with the following light-shielding layer-forming composition onto a 100 mm x 300 mm area on the lower side. The substrate was dried at 120°C for 15 minutes, and then fired at 600°C for 5 minutes to form a light-shielding layer (light-shielding area), thereby producing glass with a light-shielding layer. The visible light transmittance of the light-shielding layer was 0.2%.

[0148] -------------------------------------------------- Composition of light-shielding layer-forming composition -------------------------------------------------- • Borosilicate glass powder (SiO2-ZnO-B2O3) 70 parts by mass • Black inorganic pigment (Cr2O3-CuO-MnO) 15 parts by mass Pine oil 10 parts by mass ·Rosin 5 parts by mass --------------------------------------------------

[0149] <Fabrication of laminated glass> The reflective film 3, prepared as described above, was cut to a size of 300mm x 300mm. The area of ​​300mm x 200mm was designed to contain the ultraviolet reflective layer. As described above, a PVB film (interlayer) manufactured by Sekisui Chemical Co., Ltd., measuring 300 mm in length, 300 mm in width, and 0.76 mm in thickness, was placed on the side of the light-shielding glass with the light-shielding layer that was provided. Furthermore, a flat glass substrate (second glass substrate) measuring 300mm x 300mm with a thickness of 2mm was placed on top of the PVB film. This was held at 115°C and 10kPa (0.1 atmospheres) for 1 hour, and then heated in an autoclave (manufactured by Kurihara Seisakusho) at 140°C and 1.2MPa (12 atmospheres) for 45 minutes to remove air bubbles and form laminated glass 1.

[0150] Afterward, the protective film 2 was peeled off the reflective film 3 measuring 300mm x 300mm cut out as described above. Then, the exposed adhesive layer was brought into contact with the flat glass substrate side of the prepared laminated glass 1 that did not have a light-shielding layer, and a 2kg load was applied with a rubber roller to create the laminated glass 2 with the reflective film attached. At this time, the portion of the laminated glass 1 that does not contain the light-shielding layer (transmitting region) and the ultraviolet reflective layer of the reflective film 3 were arranged to overlap. In other words, this laminated glass 2 is The region from 0mm to 200mm from the upper edge of the laminated glass is the second region in the present invention, and has the following configuration: first glass substrate / interlayer / second glass substrate / adhesive layer 2 / cellulose acylate film 2 with alignment layer / phase difference layer A2 / ultraviolet reflection layer (visible light transmission layer) / adhesive layer 1 / reflection layer 1 / phase difference layer A1 / cellulose acylate film 1 with alignment layer. The region 200mm to 300mm from the upper edge of the laminated glass is the first region in the present invention, and has the following configuration: first glass substrate / light shielding layer / interlayer / second glass substrate / adhesive layer 2 / cellulose acylate film 2 with alignment layer / phase difference layer A2 / reflective layer 2 / adhesive layer 1 / reflective layer 1 / phase difference layer A1 / cellulose acylate film 1 with alignment layer. In this laminated glass 2, The reflective layer 1 is a cholesteric liquid crystal layer consisting of three layers: cholesteric liquid crystal layer IR1, cholesteric liquid crystal layer R1, and cholesteric liquid crystal layer BG1. The reflective layer 2 is a cholesteric liquid crystal layer consisting of three layers: reflective layer IR2, reflective layer R2, and reflective layer BG2. The ultraviolet reflective layer is a cholesteric liquid crystal layer consisting of three layers: ultraviolet reflective layer UV3, ultraviolet reflective layer UV2, and ultraviolet reflective layer UV1. Furthermore, in reflective layer 1, reflective layer 2, and the ultraviolet reflective layer, the layering order of each layer is from the side of the cellulose acylate film 1 with the alignment film (assuming the interior side (light incident side)). This is also the case for the laminated glass examples described later.

[0151] [Example 2] A cholesteric liquid crystal layer-equipped film RGB was prepared in the same manner as in Example 1.

[0152] On the other hand, a resin substrate with an orientation film (cellulose acylate film with orientation film) was prepared in the same manner as in Example 1, and a phase difference layer (phase difference layer A2) was formed and a rubbing treatment was performed. On the surface of the formed 400mm x 300mm phase difference layer A2, coating solution BG2 was further applied using a wire bar at room temperature to form a coating film so that the dry film thickness after drying was 0.30 μm. The coating was dried at room temperature for 30 seconds, and then heated in a 60°C atmosphere for 1 minute. Subsequently, under air (oxygen concentration: approximately 20 vol%) at 40°C, the coating was exposed to light from a 365nm LED lamp (manufactured by Acroedge Co., Ltd.) at an illuminance of 300 mW / cm². 2 , irradiation amount 60mJ / cm 2 The LED lamp was irradiated using the following method. At this time, of the substrate measuring 400mm in height and 300mm in width, 400mm in height and 200mm in width was covered with black PET to shield the LED lamp. Furthermore, the resulting composition layer was heated at 60°C for 10 seconds. Subsequently, in an environment with an oxygen concentration of 1000 ppm or less, the composition layer was irradiated with light from a metal halide lamp (manufactured by iGraphics Co., Ltd.) at 120°C (irradiation dose: 300 mJ / cm²). 2 )did. Thus, a cholesteric liquid crystal layer-attached film BGISO1 (sixth functional layer) was formed, which has a reflective layer BG3 (visible light reflective layer (cholesteric liquid crystal layer), selective reflection center wavelength: 458 nm, film thickness: 0.30 μm, LED lamp transmission part) in a region of 400 mm length × 100 mm width (first region) within a 400 mm length × 300 mm width area, and has an ISO layer (isotropic layer) ISO1 (visible light transmission layer, film thickness: 0.30 μm, LED lamp light blocking part) in a region of 400 mm length × 200 mm width (second region).

[0153] Next, coating liquid R2 was further applied onto the cholesteric liquid crystal layer-side surface of the obtained cholesteric liquid crystal layer-attached film BGISO1 at room temperature using a wire bar such that the dry film thickness after drying was 0.54 μm, thereby forming a coating film. After drying the coating film at room temperature for 30 seconds, it was heated in an atmosphere at 60°C for 1 minute. Thereafter, under air (oxygen concentration: about 20% by volume), light from a 365 nm LED lamp (manufactured by Acro Edge Co., Ltd.) was applied to the coating film at an illuminance of 300 mW / cm 2 and an irradiation dose of 60 mJ / cm 2 At this time, among a base material of 400 mm length × 300 mm width, the 400 mm length × 200 mm width region blocked the light from the LED lamp with black PET. In this process, the portion blocked by the black PET was arranged to overlap with the ISO layer ISO1. Furthermore, the obtained composition layer was heated at 60°C for 10 seconds. Thereafter, in an environment with an oxygen concentration of 1000 ppm or less, the composition layer was irradiated with light from a metal halide lamp (manufactured by Eye Graphics Co., Ltd.) at 120°C (irradiation dose: 300 mJ / cm 2 ). Thus, a cholesteric liquid crystal layer-attached film RISO1 (fifth functional layer) was formed, which has a reflective layer R3 (visible light reflective layer (cholesteric liquid crystal layer), selective reflection center wavelength: 676 nm, film thickness: 0.54 μm, LED lamp transmission part) in a region of 400 mm length × 100 mm width (first region) within a 400 mm length × 300 mm width area, and has an ISO layer ISO2 (visible light transmission layer, film thickness: 0.54 μm, LED lamp light blocking part) in a region of 400 mm length × 200 mm width (second region).

[0154] Next, the coating liquid IR2 was further applied onto the cholesteric liquid crystal layer side surface of the film RISO1 with a cholesteric liquid crystal layer at room temperature using a wire bar so that the thickness of the dried film after drying was 0.43 µm, thereby forming a coating film. After drying the coating film at room temperature for 30 seconds, it was heated in an atmosphere of 60°C for 1 minute. Then, under air (oxygen concentration: about 20% by volume), light from a 365 nm LED lamp (manufactured by Acro Edge Co., Ltd.) was applied to the coating film at an illuminance of 300 mW / cm 2 at an irradiation dose of 60 mJ / cm 2 for irradiation. At this time, among a substrate of 400 mm length × 300 mm width, an area of 400 mm length × 200 mm width was shielded from the light of the LED lamp with black PET. At this time, the portion shielded by the black PET was made to overlap with the ISO layer ISO2. Further, the obtained composition layer was heated at 60°C for 10 seconds. Then, in an environment with an oxygen concentration of 1000 ppm or less, the composition layer was irradiated with light from a metal halide lamp (manufactured by Eye Graphics Co., Ltd.) at 120°C (irradiation dose: 300 mJ / cm 2 ). As a result, a reflection layer IR3 (visible light reflection layer (cholesteric liquid crystal layer), selective reflection center wavelength: 798 nm, film thickness: 0.43 µm, LED lamp transmission portion) was formed in a region (first region) of 400 mm length × 100 mm width among 400 mm length × 300 mm width, and an ISO layer ISO3 (visible light transmission layer, film thickness: 0.43 µm, LED lamp light shielding portion) was formed in a region (second region) of 400 mm length × 200 mm width among 400 mm length × 300 mm width, thereby obtaining film IRISO1 (fourth functional layer) with a cholesteric liquid crystal layer.

[0155] Using the prepared cholesteric liquid crystal layer-attached film RBG, the cholesteric liquid crystal layer-attached film BGISO1, the cholesteric liquid crystal layer-attached film RISO1, and the laminated film having the cholesteric liquid crystal layer-attached film IRISO1, a reflective film was produced in the same manner as in Example 1, and further a laminated glass with the reflective film was produced. That is, this laminated glass is The region from 0mm to 200mm from the upper edge of the laminated glass is the second region in the present invention, and has the following configuration: first glass substrate / interlayer / second glass substrate / adhesive layer 2 / cellulose acylate film 2 with alignment layer / phase difference layer A2 / isotropic layer / adhesive layer 1 / reflective layer 1 / phase difference layer A1 / cellulose acylate film 1 with alignment layer. The region from 200mm to 300mm from the top edge of the glass is the first region in the present invention, and has the following configuration: first glass substrate / light shielding layer / interlayer / second glass substrate / adhesive layer 2 / cellulose acylate film 2 with alignment layer / phase difference layer A2 / reflective layer 2 / adhesive layer 1 / reflective layer 1 / phase difference layer A1 / cellulose acylate film 1 with alignment layer. In this laminated glass, The reflective layer 1 is a cholesteric liquid crystal layer consisting of three layers: cholesteric liquid crystal layer IR1, cholesteric liquid crystal layer R1, and cholesteric liquid crystal layer BG1. The reflective layer 2 is a three-layer cholesteric liquid crystal layer composed of reflective layer IR3, reflective layer R3, and reflective layer BG3. An isotropic layer is a three-layer isotropic layer composed of ISO layer ISO3, ISO layer ISO2, and ISO layer ISO1.

[0156] [Example 3] A resin substrate with an orientation film (cellulose acylate film with orientation film) was prepared in the same manner as in Example 1. This resin substrate with an orientation film was cut to 400 mm in length and 300 mm in width, and a rubbing process (rayon cloth, pressure: 0.1 kgf (0.98 N), rotation speed: 1000 rpm, conveying speed: 10 m / min, number of passes: 1 back and forth) was applied to the orientation film side of the resin substrate in a direction rotated 45° counterclockwise from the long side of the resin substrate. A coating solution A2 was applied to the rubbed orientation film surface using a wire bar at room temperature so that the dry film thickness after drying was 0.71 μm, thereby forming a coating film. The coating was dried at room temperature for 30 seconds, and then heated in a 60°C atmosphere for 1 minute. Subsequently, in an environment with an oxygen concentration of 1000 ppm or less, the coating film was irradiated with light from a metal halide lamp (manufactured by iGraphics Co., Ltd.) at 50°C (irradiation dose: 300 mJ / cm²). 2 By doing so, a phase difference layer A3 (Re(550): 126 nm, film thickness: 0.71 μm) was formed.

[0157] Next, coating solution IR3 was applied to the surface of the formed phase difference layer A3 using a wire bar at room temperature so that the dry film thickness after drying was 0.86 μm. After drying the coating film at room temperature for 30 seconds, it was heated in a 60°C atmosphere for 1 minute. Subsequently, under air (oxygen concentration: approximately 20 vol%) at 40°C, the coating was exposed to light from a 365nm LED lamp (manufactured by Acroedge Co., Ltd.) at an illuminance of 250 mW / cm². 2 , irradiation amount 60mJ / cm 2 The LED lamp was irradiated using the following method. At this time, of the 400mm x 300mm resin substrate, 400mm x 100mm was black PET to shield the LED lamp. Furthermore, the resulting composition layer was heated at 60°C for 10 seconds. Subsequently, in an environment with an oxygen concentration of 1000 ppm or less, the composition layer was irradiated with light from a metal halide lamp (manufactured by iGraphics Co., Ltd.) at 50°C (irradiation dose: 300 mJ / cm²). 2 )did. As a result, a cholesteric liquid crystal layer-equipped film IRUV2 (first functional layer) was formed, having a reflective layer IR4 (visible light reflective layer (cholesteric liquid crystal layer), selective reflection center wavelength: 798 nm, film thickness: 0.43 μm) and an ultraviolet reflective layer UV4 (visible light transmitting layer (cholesteric liquid crystal layer), selective reflection center wavelength: 320 nm, film thickness: 0.43 μm) (LED lamp transmitting portion) laminated from the alignment film side in a 400 mm x 300 mm region (second region), and a reflective layer IR5 (visible light reflective layer (cholesteric liquid crystal layer), selective reflection center wavelength: 798 nm, film thickness: 0.86 μm, LED lamp light shielding portion).

[0158] Next, coating solution R3 was applied to the cholesteric liquid crystal layer side of the cholesteric liquid crystal layer-equipped film IRUV2 using a wire bar at room temperature to form a coating film such that the dry film thickness after drying was 1.08 μm. The coating was dried at room temperature for 30 seconds, and then heated in a 60°C atmosphere for 1 minute. Subsequently, under air (oxygen concentration: approximately 20 vol%) at 40°C, the coating was exposed to light from a 365nm LED lamp (manufactured by Acroedge Co., Ltd.) at an illuminance of 250 mWJ / cm². 2 , irradiation amount 60mJ / cm 2 The LED lamp was irradiated using the following method. At this time, 400mm x 100mm of the 400mm x 300mm substrate was covered with black PET to shield the LED lamp. In this case, the area shielded by the black PET overlapped with the reflective layer IR5. Furthermore, the resulting composition layer was heated at 60°C for 10 seconds. Subsequently, in an environment with an oxygen concentration of 1000 ppm or less, the composition layer was irradiated with light from a metal halide lamp (manufactured by iGraphics Co., Ltd.) at 50°C (irradiation dose: 300 mJ / cm²). 2 )did. As a result, a 400mm x 300mm area (second region) has a reflective layer R4 (visible light reflective layer (cholesteric liquid crystal layer), selective reflection center wavelength: 676nm, film thickness: 0.54μm) and an ultraviolet reflective layer UV5 (visible light transmitting layer, selective reflection center wavelength: 320nm, film thickness: 0.54μm) (LED lamp transmitting portion) laminated from the alignment film side, and a cholesteric liquid crystal layer film RUV2 (second functional layer) has a reflective layer R5 (visible light reflective layer (cholesteric liquid crystal layer), selective reflection center wavelength: 676nm, film thickness: 1.08μm, LED lamp light shielding portion) in a 400mm x 100mm area (first region).

[0159] Next, coating solution BG3 was applied to the cholesteric liquid crystal layer side of the cholesteric liquid crystal layer-equipped film RUV2 using a wire bar at room temperature to form a coating film such that the dry film thickness after drying was 0.60 μm. The coating was dried at room temperature for 30 seconds, and then heated in a 60°C atmosphere for 1 minute. Subsequently, under air conditions (oxygen concentration: approximately 20 vol%), the coating was exposed to light from a 365nm LED lamp (manufactured by Acroedge Co., Ltd.) at 40°C, at a temperature of 250 mWJ / cm². 2 , irradiation amount 60mJ / cm 2 The LED lamp was irradiated using the following method. At this time, 400mm x 100mm of the 400mm x 300mm substrate was covered with black PET to shield the LED lamp. In this case, the area shielded by the black PET overlapped with the reflective layer R5. Furthermore, the resulting composition layer was heated at 60°C for 10 seconds. Subsequently, in an environment with an oxygen concentration of 1000 ppm or less, the composition layer was irradiated with light from a metal halide lamp (manufactured by iGraphics Co., Ltd.) at 50°C (irradiation dose: 300 mJ / cm²). 2 )did. As a result, in a region of 400mm x 300mm (vertical x horizontal), a 400mm x 200mm area (second region) has a reflective layer BG4 (visible light reflective layer (cholesteric liquid crystal layer), selective reflection center wavelength: 458nm, film thickness: 0.30μm) and an ultraviolet reflective layer UV6 (visible light transmitting layer (cholesteric liquid crystal layer), selective reflection center wavelength: 320nm, film thickness: 0.30μm) (LED lamp transmitting portion) laminated from the alignment film side, and in a region of 400mm x 100mm (vertical x horizontal), a cholesteric liquid crystal layer film BUV2 (third functional layer) has a reflective layer BG5 (visible light reflective layer (cholesteric liquid crystal layer), selective reflection center wavelength: 458nm, film thickness: 0.60μm, LED lamp light shielding portion).

[0160] Next, coating solution TW1 was applied to the cholesteric liquid crystal layer side of the cholesteric liquid crystal layer-equipped film BUV2 using a wire bar at room temperature to form a coating film such that the dry film thickness after drying was 2.1 μm. The coating was dried at room temperature for 30 seconds, and then heated in a 60°C atmosphere for 1 minute. Subsequently, in an environment with an oxygen concentration of 1000 ppm or less, the coating film was irradiated with light from a metal halide lamp (manufactured by iGraphics Co., Ltd.) at 75°C (irradiation dose: 300 mJ / cm²). 2By this, TW (twist layer) 1 (second retardation layer, number of pitches x: 0.3, film thickness y: 2.1 μm), which is a liquid crystal layer in which a liquid crystal compound is helically twisted and aligned in the thickness direction, was formed.

[0161] The following components were mixed to prepare a composition (H) for forming a heat seal layer. ―――――――――――――――――――――――――――――――― Composition of heat seal layer forming composition (H) ―――――――――――――――――――――――――――――――― - Photopolymerization initiator (Omnirad 127, manufactured by IGM Resins B.V.) 2 parts by mass - Particles (MX-180TA) (manufactured by Soken Chemical & Engineering Co., Ltd.) 1 part by mass - Binder (Clarity LA4285, manufactured by Kuraray Co., Ltd.) 97 parts by mass - Mixed solvent (MEK / butyl acetate (including butyl acetate used in the dispersion) prepared to have a mass ratio of 50 / 50)) Amount to give a solid content concentration of 10% by mass ――――――――――――――――――――――――――――――――

[0162] (Formation of heat seal layer) On the surface on the TW1 side, the heat seal layer forming composition H was applied such that the film thickness after drying was 0.7 μm. After application, the cover was sealed at room temperature to create a solvent atmosphere, and the mixture was allowed to stand for 15 seconds. Thereafter, the coating was heated at 120° C. for 60 seconds, and in a room temperature environment with an oxygen concentration of 100 ppm by volume or less, 300 mJ / cm 2 was exposed to an integrated light amount to form a heat seal layer (second adhesive layer), and the reflective film 1 with a heat seal layer was produced.

[0163] <Production of laminated glass> The heat-sealed reflective film 1, prepared as described above, was cut to a size of 300 mm (vertical) x 300 mm (horizontal). The area of ​​300 mm (vertical) x 200 mm (horizontal) was designed to have the ultraviolet reflective layer. Using the cut heat-sealed reflective film 1, laminated glass with a reflective film was fabricated in the same manner as in Example 1. In other words, this laminated glass is The region from 0mm to 200mm from the top edge of the laminated glass is the second region in this invention, and has the following structure: first glass substrate / interlayer / second glass substrate / heat seal layer / twist layer / ultraviolet reflective layer (visible light transmitting layer) / visible light reflective layer / phase difference layer A3 / cellulose acylate film with alignment film. The region from 200mm to 300mm from the top edge of the glass is the first region in this invention, and has the following structure: first glass substrate / light shielding layer / interlayer / second glass substrate / heat seal layer / twist layer / visible light reflective layer / phase difference layer A3 / cellulose acylate film with alignment layer. In this laminated glass, The visible light reflective layer in the second region is a cholesteric liquid crystal layer consisting of three layers: reflective layer IR4, reflective layer R4, and reflective layer BG4. The ultraviolet reflective layer in the second region is a three-layer cholesteric liquid crystal layer consisting of ultraviolet reflective layer UV4, ultraviolet reflective layer UV5, and ultraviolet reflective layer UV6. The visible light reflective layer of the first region is a cholesteric liquid crystal layer consisting of three layers: reflective layer IR5, reflective layer R5, and reflective layer BG5.

[0164] [Example 4] A resin substrate with an orientation film (cellulose acylate film with orientation film) was prepared in the same manner as in Example 3, and then a phase difference layer A3 was formed. Next, coating solution IR4 was applied to the surface of the formed phase difference layer A3 using a wire bar at room temperature so that the dry film thickness after drying was 0.86 μm, thereby forming a coating film. The coating was dried at room temperature for 30 seconds, and then heated in a 60°C atmosphere for 1 minute. Subsequently, under air (oxygen concentration: approximately 20 vol%) at 40°C, the coating was exposed to light from a 365nm LED lamp (manufactured by Acroedge Co., Ltd.) at an illuminance of 300 mW / cm². 2 , irradiation amount 60mJ / cm 2 The LED lamp was irradiated using the following method. At this time, of the 400mm x 300mm resin substrate, 400mm x 200mm was made semi-transparent by a polarizing plate. Furthermore, the resulting composition layer was heated at 60°C for 10 seconds. Subsequently, in an environment with an oxygen concentration of 1000 ppm or less, the composition layer was irradiated with light from a metal halide lamp (manufactured by iGraphics Co., Ltd.) at 120°C (irradiation dose: 300 mJ / cm²). 2 )did. As a result, a cholesteric liquid crystal layer-attached film IRISO2 (first functional layer) was formed, having a reflective layer IR6 (visible light reflective layer (cholesteric liquid crystal layer), selective reflection center wavelength: 798 nm, film thickness: 0.43 μm) and an ISO layer 4 (visible light transmitting layer, film thickness: 0.43 μm) (LED lamp semi-transparent portion) laminated from the alignment film side in a 400 mm x 300 mm region (second region), and a reflective layer IR7 (visible light reflective layer (cholesteric liquid crystal layer), selective reflection center wavelength: 798 nm, film thickness: 0.86 μm, LED lamp transmitting portion).

[0165] Next, coating solution R4 was applied to the cholesteric liquid crystal layer side of the cholesteric liquid crystal layer-equipped film IRISO2 using a wire bar at room temperature to form a coating film such that the dry film thickness after drying was 1.08 μm. The coating was dried at room temperature for 30 seconds, and then heated in a 60°C atmosphere for 1 minute. Subsequently, under air (oxygen concentration: approximately 20 vol%) at 40°C, the coating was exposed to light from a 365nm LED lamp (manufactured by Acroedge Co., Ltd.) at an illuminance of 300 mWJ / cm². 2 , irradiation amount 60mJ / cm 2 The sample was irradiated using the following method. Of the 400mm x 300mm resin substrate, 400mm x 200mm was made a polarizing plate to semi-transmit the LED lamp light. In this configuration, the transmissive portion and the reflective layer IR7 were made to overlap. Furthermore, the resulting composition layer was heated at 60°C for 10 seconds. Subsequently, in an environment with an oxygen concentration of 1000 ppm or less, the composition layer was irradiated with light from a metal halide lamp (manufactured by iGraphics Co., Ltd.) at 120°C (irradiation dose: 300 mJ / cm²). 2 )did. As a result, a cholesteric liquid crystal layer-equipped film RISO2 (second functional layer) was formed, having a reflective layer R6 (visible light reflective layer (cholesteric liquid crystal layer), selective reflection center wavelength: 676 nm, film thickness: 0.54 μm) and an ISO layer 5 (visible light transmitting layer, film thickness: 0.54 μm) (LED lamp semi-transparent portion) laminated from the alignment film side in a 400 mm x 300 mm region (second region), and a reflective layer R7 (visible light reflective layer (cholesteric liquid crystal layer), selective reflection center wavelength: 676 nm, film thickness: 1.08 μm, LED lamp transmitting portion).

[0166] Next, coating solution BG4 was applied to the cholesteric liquid crystal layer side of the cholesteric liquid crystal layer-equipped film RISO2 using a wire bar at room temperature to form a coating film such that the dry film thickness after drying was 0.60 μm. The coating was dried at room temperature for 30 seconds, and then heated in a 60°C atmosphere for 1 minute. Subsequently, under air (oxygen concentration: approximately 20 vol%) at 40°C, the coating was exposed to light from a 365nm LED lamp (manufactured by Acroedge Co., Ltd.) at an illuminance of 300 mWJ / cm². 2 , irradiation amount 60mJ / cm 2 The sample was irradiated using the following method. At this time, a 400mm x 300mm resin substrate was used, with 400mm x 200mm of the substrate being polarized to allow the LED lamp to pass through semi-transmittently. In this configuration, the transmissive portion and the reflective layer R7 were made to overlap. Furthermore, the resulting composition layer was heated at 60°C for 10 seconds. Subsequently, in an environment with an oxygen concentration of 1000 ppm or less, the composition layer was irradiated with light from a metal halide lamp (manufactured by iGraphics Co., Ltd.) at 120°C (irradiation dose: 300 mJ / cm²). 2By doing so, a cholesteric liquid crystal layer film BISO2 (third functional layer) was formed, having a reflective layer BG6 (visible light reflective layer (cholesteric liquid crystal layer), selective reflection center wavelength: 458 nm, film thickness: 0.30 μm) and an ISO layer 6 (film thickness: 0.30 μm) (LED lamp semi-transparent portion) laminated from the alignment film side in a 400 mm x 300 mm region (second region), and a reflective layer BG7 (visible light reflective layer (cholesteric liquid crystal layer), selective reflection center wavelength: 458 nm, film thickness: 0.60 μm, LED lamp transparent portion).

[0167] A TW layer (second phase difference layer) was formed on the surface of the cholesteric liquid crystal layer-equipped film BISO2 in the same manner as in Example 3. Furthermore, a heat-seal layer (second adhesive layer) was formed on the surface of this TW layer in the same manner as in Example 3. This allowed us to fabricate a reflective film 2 with a heat-sealed layer.

[0168] <Fabrication of laminated glass> The heat-sealed reflective film 2 prepared in this manner was cut to a size of 300mm x 300mm. It was ensured that the 300mm x 200mm area contained the ISO layer (isotropic layer). Using the cut heat-sealed reflective film 2, laminated glass with a reflective film was fabricated in the same manner as in Example 1. In other words, this laminated glass is The region from 0mm to 200mm from the upper edge of the laminated glass is the second region in the present invention, and has the following configuration: first glass substrate / interlayer / second glass substrate / heat seal layer / twist layer / ISO layer / visible light reflective layer / phase difference layer A3 / cellulose acylate film with alignment film. The region from 200mm to 300mm from the top edge of the glass is the first region in this invention, and has the following structure: first glass substrate / light shielding layer / interlayer / second glass substrate / heat seal layer / twist layer / visible light reflective layer / phase difference layer A3 / cellulose acylate film with alignment layer. In this laminated glass, The visible light reflective layer in the second region is a cholesteric liquid crystal layer consisting of three layers: reflective layer IR6, reflective layer R6, and reflective layer BG6. The ISO layer in the second region is a three-layer isotropic layer consisting of ISO layer 4, ISO layer 5, and ISO layer 6. The visible light reflective layer of the first region is a cholesteric liquid crystal layer consisting of three layers: reflective layer IR7, reflective layer R7, and reflective layer BG7.

[0169] [Example 5] In Example 1, the rotation angle clockwise in the rubbing process of the orientation film forming the phase difference layer A2 was changed from 15° to 20°. The thickness of the phase difference layer A2 was changed from 1.5 μm to 1.3 μm, and Re(550) was changed from 265 nm to 230 nm. Except for reducing the thickness of each functional layer formed on top of this phase difference layer to 3 / 4, Laminated glass with a reflective film was prepared in the same manner as in Example 1.

[0170] [Comparative Example 1] Laminated glass with reflective films was fabricated in the same manner as in Example 1, except that the reflective films BGUV1 (6th functional layer), RUV1 (5th functional layer), and IRUV (4th functional layer) were not formed.

[0171] [Comparative Example 2] In Example 1, laminated glass with reflective films was manufactured in the same manner as in Example 1, except that black PET was not used to shield the LED lamps during the formation of the reflective film BGUV1 (6th functional layer), cholesteric liquid crystal film RUV1 (5th functional layer), and cholesteric liquid crystal film IRUV (4th functional layer).

[0172] [Measurement of film thickness] For the fabricated laminated glass with a reflective film, the total film thickness of the cholesteric liquid crystal layer (visible light reflective layer) in the first and second regions was measured using the following method. Using an ultramicrotome (Leica, UltracutUCT), a cross-section perpendicular to one of the main surfaces of each cholesteric liquid crystal layer was cut. Cross-sectional images (no pre-processing, acceleration voltage: 2kV, magnification: 15Kx) were obtained from these cross-sectional images using a high-resolution field emission scanning electron microscope (FE-SEM, Hitachi High-Technologies Corporation, S-4800). The film thickness of the cholesteric liquid crystal layer in the first and second regions was measured from the obtained cross-sectional images, and the total film thickness of the cholesteric liquid crystal layer (visible light reflective layer) in the first and second regions was measured. The film thickness of each cholesteric liquid crystal layer was measured at five arbitrary points, and the arithmetic mean of these measurements was used to determine the film thickness of the cholesteric liquid crystal layer. Table 2 below shows the total film thickness dA of the cholesteric liquid crystal layer (visible light reflective layer) in the first region, the total film thickness dB of the cholesteric liquid crystal layer in the second region, and the ratio dA / dB of the total film thicknesses.

[0173] [Evaluation of visible light transmittance] For the fabricated laminated glass (with reflective film), natural light was incident from the opposite side of the reflective film in the transmission region, at a direction of 0° to the normal direction of the laminated glass, and the transmittance spectrum was measured using a spectrophotometer (JASCO Corporation, V-670). In accordance with JIS R3106, transmittance was calculated and evaluated at wavelengths of 380 to 780 nm in 10 nm increments by multiplying the transmittance by a coefficient corresponding to the luminous sensitivity and the emission spectrum of light source A. The transmittance was evaluated according to the following evaluation criteria. Criteria for evaluating transmittance A: 82% or more (When laminated glass is formed with green glass, the transmittance will well exceed 70%) • B: Less than 82% (When laminated glass is formed with green glass, the transmittance will be less than 70%. This does not meet legal regulations.)

[0174] [Evaluation of visibility] As conceptually shown in Figure 7, an image display device (Apple Inc., iPad®) as a light source was fixed and installed on a horizontal floor surface with the image projection angle adjusted. The laminated glass was then positioned using a base so that the distance between the center of the fabricated (reflective film-coated) laminated glass light-shielding section (image display section) and the image display device was 0.5 m. At this time, the laminated glass was tilted so that the angle between the floor surface and the laminated glass surface was 30°. The optical path of the light emitted from the image display device and the optical path of its specularly reflected light are in a plane perpendicular to the floor (within the plane of the paper in Figure 7), and the P-polarized projected light is set to incident on the laminated glass at an incident angle of 73°. The visibility of the projected image in the light-shielding area was visually evaluated from a position where the projected image could be observed after displaying the image on an image display device and projecting it onto laminated glass. The criteria for evaluating visibility are as follows: A: The image appears clear. B: The image appears blurry. The results are shown in Table 2 below.

[0175] [Table 2]

[0176] As shown in Table 2, the reflective film of the present invention, in which the total thickness of the visible light reflective layer is thicker in the first region corresponding to the light-shielding region than in the second region corresponding to the transmission region, provides excellent visibility of the projected image of the HUD when displayed in the light-shielding region of the windshield glass (laminated glass), and also provides good transmittance in the transmission region of the windshield glass. Furthermore, in the laminated glass of the present invention (Examples 1 to 5), the variation in the film thickness (total film thickness) of the cholesteric liquid crystal layer (visible light reflective layer) in the first and second regions was within 5%, meaning that the film thickness of the visible light reflective layer was constant. Furthermore, the laminated glass of the present invention (Examples 1-5) exhibited a variation of luminous efficiency-corrected reflectance of the first and second regions within 1%, meaning that the luminous efficiency-corrected reflectance was constant. In contrast, in conventional windshield glass where the total thickness of the visible light reflective layer in the first and second regions is the same, when the total thickness of the visible light reflective layer is thin (Comparative Example 1), the visibility of the projected image of the HUD is poor when displayed in the light-shielding region, and when the total thickness of the visible light reflective layer is thick (Comparative Example 2), the transmittance in the transparent region of the windshield glass is poor. Based on the above results, the effects of the present invention are clear. [Industrial applicability]

[0177] It is suitable for use in automotive HUDs and the like. [Explanation of Symbols]

[0178] 10. HUD (Head-Up Display System) 12 Projectors 14 Windshield glass 16. Exterior glass panel of the vehicle 18. Inner window pane 20 Interlayer 26 Shading area 30 Reflective film 32 Surface anti-reflection layer 34 First support 36 1st retardation layer 38IR 1st functional layer 40R 2nd functional layer 42BG 3rd functional layer 50 1st adhesive layer 52IR 4th functional layer 54R 5th functional layer 56BG 6th functional layer 52h, 54h, 56h, visible light reflective layer 52t, 54t, 56t visible light transmission layer 58 Second retardation layer 60 Second support 62 2nd adhesive layer 70-layer structure 72 Mask Film 74 Base material 80 Liquid crystal composition 82 Visible light reflective layer 84 Visible light transmission layer 90 Reflective film 92IR First Functional Layer 94R Second Functional Layer 96BG 3rd functional layer 92a, 94a, 96a, 92h, 94h, 96h Visible light reflective layer 92t, 94t, 96t visible light transmission layer U Driver

Claims

1. A reflective film for a head-up display system, The reflective film has a functional layer including a visible light reflective layer that reflects visible light, The reflective film has a first region and a second region in the in-plane direction, A reflective film in which the total thickness of the visible light reflective layer in the first region is greater than the total thickness of the visible light reflective layer in the second region.

2. The reflective film according to claim 1, wherein the ratio A / B of the total thickness A of the visible light reflective layer in the first region to the total thickness B of the visible light reflective layer in the second region is 1.5 or more.

3. The reflective film according to claim 1, wherein the visible light reflective layer is a cholesteric liquid crystal layer formed by fixing a cholesteric liquid crystal phase.

4. The reflective film according to claim 1, wherein the functional layer has an ultraviolet reflective layer or an isotropic layer in the second region.

5. The reflective film according to claim 1, having a first phase difference layer, the functional layer, and a second phase difference layer in this order.

6. The reflective film according to claim 5, wherein the second phase difference layer has an adhesive layer on the side opposite to the functional layer.

7. The reflective film according to claim 5, wherein the first phase difference layer has a surface anti-reflective layer on the side opposite to the functional layer.

8. The reflective film according to claim 1, wherein the reflective film has two or more visible light reflective layers having the same selective reflection center wavelength, and further has an adhesive layer between the visible light reflective layers having the same selective reflection center wavelength.

9. The functional layer has the visible light reflective layer in the first region, and in the second region, the visible light reflective layer and an ultraviolet reflective layer or an isotropic layer are laminated in the thickness direction, and The reflective film according to claim 1, wherein the selective reflection center wavelength of the visible light reflective layer in the first region and the selective reflection center wavelength of the visible light reflective layer in the second region are the same.

10. Laminated glass comprising, in this order, an outer glass panel, an interlayer, an inner glass panel, and a reflective film according to any one of claims 1 to 9.

11. An image display system comprising laminated glass as described in claim 10, and a projector that projects an image onto the reflective film of the laminated glass.

Images