Light-absorbing anisotropic films, optical films, image display devices

Abstract

The present invention addresses the problem of providing a light absorption anisotropic film in which a region of high visibility and a region of low visibility are easily controlled when the film is applied in an image display device, and viewing angle controllability is superior. The present invention also addresses the problem of providing an optical film and an image display device.　This light absorption anisotropic film includes a dichroic substance and a liquid crystal compound, the light absorption anisotropic film having a plurality of regions having different transmittance center axis directions in the in-plane direction of the light absorption anisotropic film, the angle θ formed by the transmittance center axis and the direction normal to the surface of the light absorption anisotropic film being in the range of 0-70° in each of the plurality of regions, and any of specific conditions 1 through 3 being satisfied.

Description

[Technical Field]

[0001] This invention relates to a light-absorbing anisotropic film, an optical film, and an image display device. [Background technology]

[0002] Image display devices are used in a variety of applications, and depending on the application, they may require viewing angle control to prevent peeping and image reflections. For example, Patent Document 1 discloses a visual angle control system having a polarizer (light-absorbing anisotropic film) containing a dichroic substance and having an angle of 0 to 45° between the absorption axis and the normal to the film surface. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2009-145776 [Overview of the project] [Problems that the invention aims to solve]

[0004] In recent years, there has been a growing demand for more precise control of the viewing angle in image display devices. For example, when an image display device is used as an in-car display such as a car navigation system, there is a need to maximize visibility in areas displaying useful information for the driver, while minimizing visibility in areas displaying unhelpful information. Furthermore, there are differing needs: one passenger wants to maximize visibility to accurately and quickly view the screen to obtain information, while the other passengers do not need to view the screen and may even want to reduce its visibility to avoid obstructing their view. Thus, there is a growing need for more sophisticated control of the viewing angle of image display devices.

[0005] The present inventors investigated the viewing angle control system described in Patent Document 1 and found that there is room for further improvement in the viewing angle control capability, which controls the visibility of a displayed image according to the viewing angle.

[0006] In view of the above circumstances, the present invention aims to provide a light-absorbing anisotropic film that, when applied to an image display device, makes it easier to control areas with high visibility and areas with low visibility, and provides superior controllability of the viewing angle. Furthermore, the present invention also aims to provide an optical film and an image display device. [Means for solving the problem]

[0007] The inventors have found that the above problem can be solved by the following configuration.

[0008] [1] A light-absorbing anisotropic film comprising a dichroic substance and a liquid crystal compound, wherein the light-absorbing anisotropic film has a plurality of regions in the in-plane direction of the light-absorbing anisotropic film in which the direction of the transmittance central axis differs, and in the plurality of regions, the angle θ between the transmittance central axis and the normal direction of the surface of the light-absorbing anisotropic film is all within the range of 0 to 70°, and satisfies any of requirements 1 to 3 described below. [2] The light-absorbing anisotropic film described in [1] that satisfies requirement 1 or requirement 2 above. [3] The light-absorbing anisotropic film according to [2], wherein the angle θ increases stepwise or continuously, or decreases stepwise or continuously, as the film moves along the in-plane direction in which the multiple regions are arranged. [4] The light-absorbing anisotropic film according to [2] or [3], wherein, as the angle θ in the light-absorbing anisotropic film progresses in the in-plane direction in which the above-mentioned multiple regions are arranged, the angle θ continuously increases or continuously decreases. [5] The light-absorbing anisotropic film described in [1] that satisfies requirement 3 above. 〔6〕 Along the in-plane direction in which the at least two regions are arranged, as proceeding from the first region included in the at least two regions toward another region other than the first region, the angle φ formed by the direction of the orthographic projection of the transmittance central axis and the in-plane direction increases stepwise or continuously, or decreases stepwise or continuously. The light absorption anisotropic film according to 〔5〕. 〔7〕 Along the in-plane direction in which the at least two regions are arranged, as proceeding from the first region included in the at least two regions toward another region other than the first region, the angle φ formed by the direction of the orthographic projection of the transmittance central axis and the in-plane direction increases continuously, or decreases continuously. The light absorption anisotropic film according to 〔5〕 or 〔6〕. 〔8〕 An optical film having the light absorption anisotropic layer according to any one of 〔1〕 to 〔7〕 and an alignment film. 〔9〕 The optical film according to 〔8〕, further having a resin film containing polyvinyl alcohol or polyimide. 〔10〕 An image display device including a display panel and the optical film according to 〔8〕 or 〔9〕 disposed on one main surface of the display panel.

Advantages of the Invention

[0009] According to the present invention, when applied to an image display device, it is possible to provide a light absorption anisotropic film in which a region with high visibility and a region with low visibility are easily controlled, and the viewing angle controllability is more excellent. Further, according to the present invention, it is possible to provide an optical film and an image display device.

Brief Description of the Drawings

[0010] [Figure 1A] It is a conceptual diagram showing an example of an embodiment of the light absorption anisotropic film. [Figure 1B] It is a conceptual diagram showing an example of an embodiment of the light absorption anisotropic film. [Figure 2A] It is a conceptual diagram showing another example of an embodiment of the light absorption anisotropic film. [Figure 2B] It is a conceptual diagram showing another example of an embodiment of the light absorption anisotropic film. [Figure 3] This is a conceptual diagram showing another example of an embodiment of a light-absorbing anisotropic film. [Figure 4A] This is a conceptual diagram showing another example of an embodiment of a light-absorbing anisotropic film. [Figure 4B] This is a conceptual diagram showing another example of an embodiment of a light-absorbing anisotropic film. [Figure 4C] This is a conceptual diagram showing another example of an embodiment of a light-absorbing anisotropic film. [Figure 5A] This is a conceptual diagram showing an example of a photo-alignment treatment performed in a method for manufacturing an anisotropic light-absorbing film. [Figure 5B] This is a conceptual diagram showing an example of a photo-alignment treatment performed in a method for manufacturing an anisotropic light-absorbing film. [Figure 5C] This is a conceptual diagram showing an example of a photo-alignment treatment performed in a method for manufacturing an anisotropic light-absorbing film. [Figure 6A] This is a conceptual diagram showing another example of the photo-alignment treatment performed in the manufacturing method of light-absorbing anisotropic films. [Figure 6B] This is a conceptual diagram showing another example of the photo-alignment treatment performed in the manufacturing method of light-absorbing anisotropic films. [Figure 6C] This is a conceptual diagram showing another example of the photo-alignment treatment performed in the manufacturing method of light-absorbing anisotropic films. [Figure 7] This is a conceptual diagram showing another example of the photo-alignment treatment performed in the manufacturing method of light-absorbing anisotropic films. [Figure 8A] This is a conceptual diagram showing another example of the photo-alignment treatment performed in the manufacturing method of light-absorbing anisotropic films. [Figure 8B] This is a conceptual diagram showing another example of the photo-alignment treatment performed in the manufacturing method of light-absorbing anisotropic films. [Figure 9] This is a conceptual diagram showing an example of an embodiment of an image display device. [Figure 10] This is a conceptual diagram showing another example of an embodiment of an image display device. [Figure 11A] This is a diagram illustrating a method for evaluating image display devices. [Figure 11B] This is a diagram illustrating a method for evaluating image display devices. [Modes for carrying out the invention]

[0011] The present invention will be described in detail below. The following description of the constituent elements may be based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In this specification, a numerical range represented by "~" means a range that includes the numbers written before and after "~" as the lower and upper limits, respectively. Furthermore, in this specification, "parallel" does not mean parallel in the strict sense, but rather a range of ±5° from parallel. Furthermore, in this specification, "orthogonal" and "perpendicular" do not mean orthogonal and perpendicular in the strict sense, but rather that the angles are within the range of 90 ± 5°.

[0012] In this specification, "(meth)acrylic" is used to mean "either acrylic or methacrylic, or both." "(meth)acryloyl" is used to mean "either acryloyl or methacryloyl, or both." The bonding direction of the divalent group (e.g., -COO-) as expressed herein is not particularly limited. For example, if L in XLY is -COO-, and the position where it is bonded on the X side is *1 and the position where it is bonded on the Y side is *2, then L may be *1-O-CO-*2 or *1-CO-O-*2.

[0013] [Light-absorbing anisotropic film] The light-absorbing anisotropic film according to the present invention comprises a dichroic substance and a liquid crystal compound, and has multiple regions in the in-plane direction of the light-absorbing anisotropic film where the direction of the transmittance central axis differs, the angle θ between the transmittance central axis in the multiple regions and the normal direction of the surface of the light-absorbing anisotropic film is all within the range of 0 to 70°, and satisfies any of the following requirements 1 to 3. Requirement 1: The angle θ in at least one of the multiple regions is 0°. Requirement 2: In at least two of the multiple regions, the directions of the orthogonal projection of the transmittance central axis onto the surface of the light-absorbing anisotropic film are the same, and in at least two of the regions, the angle θ is different. Requirement 3: A light-absorbing anisotropic film in which, among multiple regions, the angle θ is the same in at least two regions, and in at least two regions, the direction of the orthogonal projection of the transmittance central axis onto the surface of the light-absorbing anisotropic film is different from each other.

[0014] Here, the transmittance center axis refers to the direction of highest transmittance when the transmittance is measured while varying the tilt angle and direction of the tilt relative to the normal direction to the surface of the light-absorbing anisotropic film. The transmittance center axis is measured by irradiating the light-absorbing anisotropic film with P-polarized light at a wavelength of 550 nm using an ultraviolet-visible-infrared spectrophotometer (for example, "JASCO V-670 / ARMN-735" (manufactured by JASCO Corporation)). The specific method is as follows. First, we find the direction in which the transmittance center axis is tilted relative to the normal to the surface of the light-absorbing anisotropic film. More specifically, we cut a sample of the light-absorbing anisotropic film into, for example, a 4cm square, and set the obtained sample on the sample stage of an optical microscope (for example, Nikon Corporation, product name "ECLIPSE E600 POL") with a linear polarizer placed on the light source side. Next, using a multi-channel spectrometer (for example, Ocean Optics, product name "QE65000"), we monitor the absorbance of the sample at a wavelength of 550nm while rotating the sample stage clockwise by 1° at a time, and identify the direction in which the absorbance is maximum. Based on this direction in the plane of the sample in which the absorbance is maximum, we determine the angle φ of the light-absorbing anisotropic film. Next, the transmittance of the anisotropic light-absorbing film is measured by irradiating it with P-polarized light at a wavelength of 550 nm while changing the angle θ (polar angle) with respect to the normal of the surface of the anisotropic light-absorbing film from 0 to 70° in 0.5° increments within a plane containing the normal of the anisotropic light-absorbing film along the direction in which the transmittance is maximized (a plane containing the transmittance center axis and perpendicular to the layer surface). The direction with the highest transmittance obtained from this measurement is the transmittance center axis, and the angle θ between the transmittance center axis and the normal of the surface of the anisotropic light-absorbing film is determined. If the direction in which absorbance is maximized cannot be clearly identified by the initial measurement of angle φ, it is assumed that the direction of the transmittance central axis is aligned with the normal direction of the surface of the light-absorbing anisotropic film. Then, the angle θ is measured with respect to an arbitrary plane containing the normal of the light-absorbing anisotropic film, and it is confirmed that the angle θ is 0°.

[0015] The light-absorbing anisotropic film of the present invention will be described below with reference to the drawings, based on specific embodiments. However, the present invention is not limited to the following embodiments.

[0016] [First Embodiment] One embodiment of the light-absorbing anisotropic film according to the present invention is a light-absorbing anisotropic film that satisfies either requirement 1 or requirement 2 above. Figures 1A and 1B (hereinafter collectively referred to as "Figure 1") are conceptual diagrams showing an example of the configuration of a light-absorbing anisotropic film according to this embodiment. The light-absorbing anisotropic film 10 shown in Figure 1 contains a dichroic substance 1 and a liquid crystal compound (not shown), and the light-absorbing anisotropic film 10 has a first region 11 and a second region 12 arranged side by side along the X-axis in the plane. Figure 1A is a plan view of the light-absorbing anisotropic film 10 observed from the direction normal to the surface of the light-absorbing anisotropic film 10. Figure 1B is a cross-sectional view of the light-absorbing anisotropic film 10 along the AA line shown in Figure 1A.

[0017] Here, as shown in Figure 1A, the longitudinal direction of the long, rectangular light-absorbing anisotropic film 10 (left-right direction on the paper) is defined as the X-axis, the direction perpendicular to the X-axis (up-down direction on the paper) is defined as the Y-axis, and the normal direction of the light-absorbing anisotropic film 10 (perpendicular to the paper) is defined as the Z-axis. Furthermore, the direction toward the right on the paper is defined as the positive direction of the X-axis, the direction toward the top of the paper is defined as the positive direction of the Y-axis, and the direction toward the front of the paper is defined as the positive direction of the Z-axis. Furthermore, the angle θ (polar angle) between the direction of the transmittance central axis and the normal direction of the surface of the light-absorbing anisotropic film 10 is defined as increasing as it approaches the light-absorbing anisotropic film 10, with the positive Z-axis as the reference (θ=0°), and becoming θ=90° in the in-plane direction of the light-absorbing anisotropic film 10. Furthermore, regarding the angle φ (azimuth angle) in the direction in which the orthogonal projection of the transmittance center axis extends within the plane of the light-absorbing anisotropic film 10 shown in Figure 1, it is defined that the angle φ increases as the direction extending in the negative direction of the X axis is used as the reference (φ=0°). Note that, as with the inclination of the major axis of the dichroic substance 1 contained in the first region 11 in Figure 1B, if the angle θ in a certain direction is 0°, the angle φ in that direction cannot be determined and is therefore considered nonexistent. In this specification, unless otherwise specified, the X-axis, Y-axis, Z-axis, angle θ, and angle φ shall be in accordance with the above provisions.

[0018] As shown in Figure 1, the orientation of the dichroic material 1 differs within the first region 11 and the second region 12 of the light-absorbing anisotropic film 10. More specifically, in the first region 11, the orientation of the major axis of the dichroic material 1 is parallel to the Z-axis, while in the second region 12, the orientation of the major axis of the dichroic material 1 is tilted at an angle θ from the positive Z-axis toward the negative X-axis. Therefore, the light-absorbing anisotropic film 10 has a first region 11 where the angle θ between the transmittance center axis and the normal direction of the light-absorbing anisotropic film 10 is 0°, and a second region 12 where the angle θ between the transmittance center axis and the normal direction of the light-absorbing anisotropic film 10 is greater than 0°, thus satisfying requirement 1.

[0019] By applying such an anisotropic light-absorbing film 10 to an image display device, it is possible to easily control areas with high visibility and areas with low visibility, thereby further improving the viewing angle controllability of the image display device. For example, when the display image of an image display device with the light-absorbing anisotropic film 10 shown in Figure 1 is observed from position A (see Figure 1B), which is located in front of the first region 11 (normal direction of the first region 11), the transmittance center axis of the first region 11 and the transmittance center axis of the second region 12 are oriented towards position A. As a result, the transmittance in both regions becomes high, improving the visibility of the display image in both regions. On the other hand, when observed from position B (see Figure 1B), which is located in front of the second region 12 (normal direction of the second region 12), the transmittance of the first region 11 and the transmittance of the second region 12 decrease compared to when observed from position A, thus reducing the visibility of the display image in both regions.

[0020] As described above, the light-absorbing anisotropic film 10 shown in Figure 1 has a first region 11 where the angle θ between the transmittance center axis and the positive Z-axis is 0°, and a second region 12 where the angle θ between the transmittance center axis and the positive Z-axis is greater than 0°, thus satisfying requirement 1. The angle θ at this time is not particularly limited as long as it is within the range of greater than 0° and less than or equal to 70°, and is appropriately selected depending on the image display device to which it is applied. However, in terms of having a better practical viewing angle, 1° to 60° is preferred, 5° to 40° is more preferred, and 8° to 45° is even more preferred.

[0021] In the optical absorption anisotropy film 10 shown in Figure 1, an embodiment was described in which there are two regions in which the angle θ between the transmittance central axis and the normal direction of the optical absorption anisotropy film 10 is 0° or greater than 0°. However, the optical absorption anisotropy film according to this embodiment is not limited to this embodiment and may have three or more regions in which the angle θ between the transmittance central axis and the normal direction of the optical absorption anisotropy film is different.

[0022] Figures 2A and 2B (hereinafter collectively referred to as "Figure 2") are conceptual diagrams showing other examples of the configuration of the optical absorption anisotropy film according to this embodiment. The light-absorbing anisotropic film 20 shown in Figure 2 contains a dichroic substance 1 and a liquid crystal compound (not shown), and the light-absorbing anisotropic film 20 has a first region 21, a second region 22, and a third region 23 arranged in line along the X-axis direction in the plane. Figure 2A is a plan view of the light-absorbing anisotropic film 20 observed from the direction normal to the surface of the light-absorbing anisotropic film 20. Figure 2B is a cross-sectional view of the light-absorbing anisotropic film 20 in the AA line shown in Figure 2A.

[0023] As shown in Figure 2, the orientation of the dichroic material 1 differs within each of the three regions of the light-absorbing anisotropic film 20: the first region 21, the second region 22, and the third region 23. More specifically, in the first region 21, the major axis of the dichroic material 1 is parallel to the Z-axis, while in the second region 22 and the third region 23, the major axis of the dichroic material 1 is tilted from the positive Z-axis toward the negative X-axis by angles θ1 and θ2, respectively. In this case, angle θ1 < angle θ2. Therefore, the light-absorbing anisotropic film 20 has a first region 21 in which the angle θ between the transmittance central axis and the normal direction of the light-absorbing anisotropic film 20 is 0°, and a second region 22 and a third region 23 in which the angle θ between the transmittance central axis and the normal direction of the light-absorbing anisotropic film 10 is greater than 0°, thus satisfying requirement 1 above. Furthermore, in the second region 22 and the third region 23 of the light-absorbing anisotropic film 20, the direction of the orthogonal projection of the transmittance central axis is the same negative direction of the X axis, and the angle θ between the transmittance central axis and the normal direction of the light-absorbing anisotropic film 20 is different, so the light-absorbing anisotropic film 20 satisfies requirement 2 above.

[0024] By applying such an anisotropic light-absorbing film 20 to an image display device, it is possible to easily control areas with high visibility and areas with low visibility, thereby further improving the viewing angle controllability of the image display device. For example, when the display image of an image display device with the light-absorbing anisotropic film 20 shown in Figure 2 is observed from position A (see Figure 2B), which is located in front of the first region 21 (normal direction of the first region 21), the transmittance center axis of the first region 21, the transmittance center axis of the second region 22, and the transmittance center axis of the third region 23 are all oriented towards position A. As a result, the transmittance in these regions is high, improving the visibility of the display image in these regions. On the other hand, when observed from position B (see Figure 2B), which is located in front of the third region 23 (normal direction of the third region 23), the transmittance of the first region 21, the second region 22, and the third region 23 is lower compared to when observed from position A. As a result, the visibility of the display image in all regions is low.

[0025] Furthermore, in the light-absorbing anisotropic film 20 shown in Figure 2, the angle θ between the transmittance center axis and the normal direction of the light-absorbing anisotropic film 20 increases stepwise as you move in the positive direction of the X-axis where the first region 21, the second region 22, and the third region 23 are aligned. Thus, in a light-absorbing anisotropic film, it is preferable that the angle θ increases gradually or continuously, or decreases gradually or continuously, as one moves along the in-plane direction where multiple regions with different angles θ are arranged, because this improves the visibility of the image display device. In this specification, "continuously increasing" or "continuously decreasing" means that, in one direction within a plane, the increase or decrease in angle θ or angle φ per centimeter is continuously 2° or less.

[0026] As described above, the light-absorbing anisotropic film 20 shown in Figure 2 satisfies requirement 2. In such a light-absorbing anisotropic film that satisfies requirement 2, the angle θ between the transmittance center axis and the normal direction of the light-absorbing anisotropic film (angles θ1 and θ2 in the light-absorbing anisotropic film 20 shown in Figure 2) is not particularly limited as long as it is within the range of greater than 0° and 70° or less. However, in terms of better visibility of the image display device, 1° to 60° is preferred, 5° to 40° is more preferred, and 8° to 45° is even more preferred.

[0027] In the optical absorption anisotropic film 10 shown in Figure 1 and the optical absorption anisotropic film 20 shown in Figure 2, an embodiment was described in which the angle θ between the transmittance central axis and the normal direction of the optical absorption anisotropic film in each region changes in steps. However, the optical absorption anisotropic film according to this embodiment is not limited to this embodiment, and the angle θ between the transmittance central axis and the normal direction of the optical absorption anisotropic film may change continuously.

[0028] Figure 3 is a conceptual diagram showing another example of the configuration of the optically absorbing anisotropic film according to this embodiment. The light-absorbing anisotropic film 30 shown in Figure 3 contains a dichroic substance 1 and a liquid crystal compound (not shown). Here, Figure 3 is a cross-sectional view of the light-absorbing anisotropic film 30 in a plane that includes the normal to the surface of the light-absorbing anisotropic film 30 and the direction of the X-axis, in which the inclination of the major axis of the dichroic substance 1 changes. As shown in Figure 3, the long axis of the dichroic substance 1 contained in the light-absorbing anisotropic film 30 is tilted at different angles with respect to the normal direction of the light-absorbing anisotropic film 30 depending on its position in the X-axis direction within the plane. Although not shown in the figure, the tilt of the long axis of the dichroic substance 1 contained in the light-absorbing anisotropic film 30 does not change in the Y-axis direction within the plane.

[0029] As shown in Figure 3, the orientation of the dichroic material 1 differs depending on the position in the X-axis direction of the light-absorbing anisotropic film 30. More specifically, in the central part 30a of the light-absorbing anisotropic film 30 in the X-axis direction, the orientation of the major axis of the dichroic material 1 is parallel to the Z-axis, but as you move from the central part 30a toward the end 30b of the light-absorbing anisotropic film 30 in the X-axis direction, the inclination of the major axis of the dichroic material 1 increases continuously. Here, the light-absorbing anisotropic film 30 satisfies requirement 1 above because, in the central portion 30a, the angle θ between the transmittance central axis and the normal direction of the light-absorbing anisotropic film 30 is 0°. Furthermore, in regions of the light-absorbing anisotropic film 30 other than the central part 30a, the direction of the orthogonal projection of the transmittance central axis is the X-axis direction, and the angle θ between the transmittance central axis and the normal direction of the light-absorbing anisotropic film 30 is different, so the light-absorbing anisotropic film 30 satisfies requirement 2 above.

[0030] By applying such an anisotropic light-absorbing film 30 to an image display device, it is possible to easily control areas with high visibility and areas with low visibility, similar to the anisotropic light-absorbing films 10 and 20 described above, thereby further improving the viewing angle controllability of the image display device.

[0031] Furthermore, in the light-absorbing anisotropic film 30 shown in Figure 3, the angle θ between the transmittance center axis and the normal direction of the light-absorbing anisotropic film 30 continuously increases as you move from the central part 30a in the longitudinal direction towards the end 30b in the positive or negative direction of the X-axis. Thus, a light-absorbing anisotropic film in which the angle θ continuously increases or decreases as the in-plane direction, where multiple regions with different angles θ are arranged, is more preferable in that it provides better visibility for image display devices.

[0032] In the light-absorbing anisotropic film according to this embodiment, there may be multiple (two or more) regions in the plane having transmittance center axes with different angles θ with respect to the normal direction of the surface of the light-absorbing anisotropic film, and the number is not particularly limited. That is, the number of such regions may be two or more, and three or more is preferable. Furthermore, as described above, it is also preferable that the angle θ between the transmittance center axis and the normal direction of the surface of the light-absorbing anisotropic film changes continuously along the in-plane direction. In the light-absorbing anisotropic film according to this embodiment, the in-plane difference of the angle θ in the light-absorbing anisotropic film is not particularly limited, but the difference between the minimum and maximum values ​​of the angle θ in the plane of the light-absorbing anisotropic film is preferably 3 to 140°, and more preferably 5 to 120°.

[0033] In the light-absorbing anisotropic film of the first embodiment shown in Figures 1 to 3, the direction of the orthogonal projection of the transmittance central axis (the orientation of the transmittance central axis in the in-plane direction) was the same in each region. However, the light-absorbing anisotropic film according to this embodiment may further have regions with different directions of orthogonal projection of the transmittance central axis, as long as it has multiple regions that satisfy requirement 1 or requirement 2.

[0034] [Second Embodiment] Another embodiment of the light-absorbing anisotropic film according to the present invention is a light-absorbing anisotropic film that satisfies requirement 3 above. Figures 4A and 4B (hereinafter collectively referred to as "Figure 4") are conceptual diagrams showing an example of the configuration of a light-absorbing anisotropic film according to the second embodiment. The light-absorbing anisotropic film 40 shown in Figure 4 contains a dichroic substance 1 and a liquid crystal compound (not shown), and in the light-absorbing anisotropic film 40, the first region 41 and the second region 42 are arranged side by side along the Y-axis direction in the plane. Figure 4A is a plan view of the light-absorbing anisotropic film 40 observed from the direction normal to the surface of the light-absorbing anisotropic film 40. Figure 4B is a cross-sectional view of the light-absorbing anisotropic film 40 along line AA shown in Figure 4A, and Figure 4C is a cross-sectional view of the light-absorbing anisotropic film 40 along line BB shown in Figure 4A. Furthermore, for the light-absorbing anisotropic film 40 shown in Figure 4, as shown in Figure 4A, the X-axis is defined as the short-side direction of the elongated light-absorbing anisotropic film 40 (left-right direction on the paper), the Y-axis is defined as the direction perpendicular to the X-axis in the plane of the light-absorbing anisotropic film 40 (up-down direction on the paper), and the Z-axis is defined as the normal direction of the light-absorbing anisotropic film 40 (perpendicular to the paper). Also, as shown in Figure 4A, the positive direction of the X-axis is defined as the direction toward the right on the paper, the positive direction of the Y-axis is defined as the direction toward the top of the paper, and the positive direction of the Z-axis is defined as the direction toward the front of the paper.

[0035] As shown in Figure 4, the orientation of the dichroic material 1 differs within the first region 41 and the second region 42 of the light-absorbing anisotropic film 40. More specifically, in both the first region 41 and the second region 42, the long axis of the dichroic material 1 is tilted at an angle θ with respect to the positive Z-axis. However, in the first region 41, the direction of the orthogonal projection of the long axis of the dichroic material 1 onto the surface of the light-absorbing anisotropic film 40 (XY plane) is parallel to the negative X-axis, whereas in the second region 42, the direction of the orthogonal projection of the long axis of the dichroic material 1 onto the surface of the light-absorbing anisotropic film 40 (XY plane) is the direction rotated clockwise by an angle φ from the negative X-axis in the XY plane. Therefore, the light-absorbing anisotropic film 40 satisfies requirement 3 because the angle θ between the transmittance center axis and the normal direction of the light-absorbing anisotropic film 40 is the same, and the directions of the orthogonal projection of the transmittance center axis onto the surface of the light-absorbing anisotropic film 40 are different from each other.

[0036] By applying the light-absorbing anisotropic film 40 according to the second embodiment, as shown in Figure 4, to an image display device, it is possible to easily control areas with high visibility and areas with low visibility, similar to the light-absorbing anisotropic film according to the first embodiment, thereby further improving the viewing angle controllability of the image display device. The angle φ at this time is not particularly limited and is not appropriately selected depending on the image display device to which it is applied, however, it is preferable that the maximum difference in angle φ between two regions with different angles φ is 5 to 120°.

[0037] One application scenario for the image display device equipped with the light-absorbing anisotropic film according to the second embodiment is to install an in-vehicle display, such as a car navigation system, in the interior of an automobile, between the center of the dashboard (or center cluster) and the center console located between the driver's seat and the passenger seat. In this case, it is conceivable to install the image display device as an in-vehicle display in an area 30 to 40 cm forward of the vehicle, 30 to 40 cm horizontally, and 10 to 45 cm vertically downward from the driver's eye level. A preferred embodiment of the light-absorbing anisotropic film according to the second embodiment used in such an image display device is one in which the angle φ in the upper region of the light-absorbing anisotropic film laminated on the image display device is 0 to 30° (or 150 to 180°), and the angle φ in the lower region of the light-absorbing anisotropic film is 40 to 70° (or 110 to 140°). The above embodiment is merely one example of a specific example, and the directions of angles θ and φ in each region of the light-absorbing anisotropic film can be appropriately changed depending on the actual application of the image display device.

[0038] In the optical absorption anisotropy film 40 shown in Figure 4, an embodiment was described in which there are two regions in which the direction of the orthogonal projection of the transmittance central axis is different. However, the optical absorption anisotropy film according to this embodiment is not limited to this embodiment and may have three or more regions in which the direction of the orthogonal projection of the transmittance central axis is different.

[0039] Furthermore, in the light-absorbing anisotropic film 40 shown in Figure 4, if the direction of the orthogonal projection of the transmittance center axis in the first region 41 is taken as the reference direction (φ=0°), the angle φ between the direction of the orthogonal projection of the transmittance center axis and the reference direction increases stepwise as you move in the negative direction of the Y-axis where the first region 41 and the second region 42 are aligned. Thus, it is preferable for the light-absorbing anisotropic film to have an angle φ that increases stepwise or continuously, or decreases stepwise or continuously, as it progresses from a first region toward other regions, along an in-plane direction in which at least two regions with the same angle θ and different directions of orthogonal projection of the transmittance central axis are arranged, because this improves the visibility of the image display device. Furthermore, the light-absorbing anisotropic film according to this embodiment is not limited to the configuration in which the angle φ changes in steps, as shown in Figure 4. The angle φ may change continuously as the film moves along the in-plane direction in which multiple regions with different angles φ are arranged.

[0040] Furthermore, in the light-absorbing anisotropic film 40 shown in Figure 4, the angle θ of the transmittance center axis with respect to the normal direction of the light-absorbing anisotropic film is the same in each region. However, the light-absorbing anisotropic film according to this embodiment may have further regions where the angle θ is not the same, as long as it has multiple regions that satisfy requirement 3.

[0041] In the light-absorbing anisotropic films shown in Figures 1 to 4, multiple regions with different transmittance center axes are arranged side by side in only one direction within the plane. However, the light-absorbing anisotropic film of the present invention is not limited to this configuration. For example, the light-absorbing anisotropic film of the present invention may have multiple regions with different transmittance center axes arranged side by side in one direction within the plane, and multiple regions with different transmittance center axes arranged side by side in other directions within the plane.

[0042] In the light-absorbing anisotropic films shown in Figures 1 to 4, multiple dichroic materials 1 are arranged in a single direction within the plane. This is illustrated to illustrate the orientation of the dichroic materials 1, and is not intended to limit the light-absorbing anisotropic films of the present invention to this configuration.

[0043] To produce the light-absorbing anisotropic films according to the first and second embodiments described above, techniques for oriented dichroic materials to a desired orientation include techniques for producing polarizers using dichroic materials and techniques for producing guest-host liquid crystal cells. For example, techniques used in the methods for producing dichroic polarizing elements described in Japanese Patent Publication No. 11-305036 and Japanese Patent Publication No. 2002-090526, and the methods for producing guest-host type liquid crystal display devices described in Japanese Patent Publication No. 2002-099388 and Japanese Patent Publication No. 2016-027387 can be applied.

[0044] To prevent variations in the light absorption properties of anisotropic light-absorbing films due to environmental conditions, it is preferable to fix the orientation of the dichroic material by forming chemical bonds. For example, the orientation of the dichroic material can be fixed by promoting polymerization of a host liquid crystal, a dichroic material, or a polymerizable component added as desired. More specific manufacturing methods for the above-mentioned light-absorbing anisotropic film will be described later.

[0045] The composition and physical properties of the light-absorbing anisotropic film according to the present invention (hereinafter also referred to as "this light-absorbing anisotropic film") will be described in detail below.

[0046] [Composition of light-absorbing anisotropic film] This light-absorbing anisotropic film contains a dichroic material and a liquid crystal compound, and has multiple regions along at least one direction in the plane in which the direction of the transmittance central axis differs. The composition of the light-absorbing anisotropic film is not particularly limited as long as it exhibits the characteristics described above, and known components included in the light-absorbing anisotropic film can be used.

[0047] (dichroic substance) In this specification, a dichroic substance refers to a dye whose absorbance differs depending on the direction. In a light-absorbing anisotropic film, the dichroic substance may be polymerized.

[0048] Dichroic materials are not particularly limited and include visible light absorbing materials (dichroic dyes), luminescent materials (fluorescent materials, phosphorescent materials), ultraviolet absorbing materials, infrared absorbing materials, nonlinear optical materials, carbon nanotubes, and inorganic materials (e.g., quantum rods), and known dichroic materials (dichroic dyes) can be used. Specifically, paragraphs

[0067] to

[0071] of JP 2013-228706, paragraphs

[0008] to

[0026] of JP 2013-227532, paragraphs

[0008] to

[0015] of JP 2013-209367, paragraphs

[0045] to

[0058] of JP 2013-014883, paragraphs

[0012] to

[0029] of JP 2013-109090, paragraphs

[0009] to

[0017] of JP 2013-101328, paragraphs

[0051] to

[0065] of JP 2013-037353, and JP 2012-063387

[0049] ~

[0073] paragraph, paragraphs

[0016] ~

[0018] of JP A-11-305036, paragraphs

[0009] ~

[0011] of JP A-2001-133630, paragraphs

[0030] ~

[0169] of JP A-2011-215337, paragraphs

[0021] ~[0 Paragraph 075, paragraphs

[0011] to

[0025] of JP 2010-215846, paragraphs

[0017] to

[0069] of JP 2011-048311, paragraphs

[0013] to

[0133] of JP 2011-213610, paragraphs

[0074] to [0] of JP 2011-237513 Examples of dichroic substances include those described in paragraph 246, paragraphs

[0005] to

[0051] of Japanese Patent Publication No. 2016-006502, paragraphs

[0005] to

[0041] of International Publication No. 2016 / 060173, paragraphs

[0008] to

[0062] of International Publication No. 2016 / 136561, paragraphs

[0014] to

[0033] of International Publication No. 2017 / 154835, paragraphs

[0014] to

[0033] of International Publication No. 2017 / 154695, paragraphs

[0013] to

[0037] of International Publication No. 2017 / 195833, and paragraphs

[0014] to

[0034] of International Publication No. 2018 / 164252.

[0049] In a light-absorbing anisotropic film, two or more dichroic materials may be used in combination. For example, to make the resulting light-absorbing anisotropic film appear closer to black, it is preferable to use at least one dichroic material having a maximum absorption wavelength in the range of 370 nm to less than 500 nm and at least one dichroic material having a maximum absorption wavelength in the range of 500 nm to less than 700 nm.

[0050] As described later, a light-absorbing anisotropic film can be formed using a light-absorbing anisotropic film-forming composition. In the light-absorbing anisotropic film-forming composition, the dichroic substance may have crosslinking groups. When the dichroic substance has crosslinking groups, the dichroic substance can be immobilized in a predetermined orientation state when forming a light-absorbing anisotropic film using the light-absorbing anisotropic film-forming composition. Examples of crosslinkable groups include (meth)acryloyl groups, epoxy groups, oxetanyl groups, and styryl groups, with (meth)acryloyl groups being preferred.

[0051] The content of dichroic substances in the light-absorbing anisotropic film is not particularly limited, but when applied to an image display device, it is preferable that the content be 1 to 50% by mass, and more preferably 10 to 25% by mass, relative to the total mass of the light-absorbing anisotropic film, in that it is easier to control the areas with high visibility and areas with low visibility, and the viewing angle control is superior (hereinafter also referred to as "the advantage of the present invention").

[0052] (liquid crystal compound) This light-absorbing anisotropic film contains a liquid crystal compound. This allows for the orientation of dichroic substances to a higher degree while suppressing the deposition of dichroic substances. Both polymeric and low-molecular-weight liquid crystal compounds can be used as the liquid crystal compound, but polymeric liquid crystal compounds are preferred because they allow for a higher degree of orientation. Furthermore, polymeric and low-molecular-weight liquid crystal compounds may be used in combination. Here, "polymeric liquid crystal compound" refers to a liquid crystal compound that has repeating units in its chemical structure. Furthermore, "low molecular weight liquid crystal compounds" refer to liquid crystal compounds that do not have repeating units in their chemical structure. Examples of polymeric liquid crystal compounds include the thermotropic liquid crystal polymer described in Japanese Patent Publication No. 2011-237513, and the polymeric liquid crystal compounds described in paragraphs

[0012] to

[0042] of International Publication No. 2018 / 199096. Examples of low-molecular-weight liquid crystal compounds include the liquid crystal compounds described in paragraphs

[0072] to

[0088] of Japanese Patent Publication No. 2013-228706, and among these, liquid crystal compounds exhibiting smectic properties are preferred.

[0053] As for the liquid crystal compound, a polymer liquid crystal compound containing a repeating unit represented by the following formula (1) (hereinafter also abbreviated as "repeating unit (1)") is preferred because it results in a higher degree of orientation of the resulting light-absorbing anisotropic film.

[0054] [ka]

[0055] In formula (1) above, P1 represents a repeating main chain, L1 represents a single bond or a divalent linking group, SP1 represents a spacer group, M1 represents a mesogenic group, and T1 represents a terminal group.

[0056] Examples of the main chain of the repeating unit represented by P1 include the groups represented by the following formulas (P1-A) to (P1-D), and among these, the group represented by the following formula (P1-A) is preferred due to the diversity of monomers used as raw materials and the ease of handling.

[0057] [ka]

[0058] In the above equations (P1-A) to (P1-D), "*" represents the bond position with L1 in equation (1). In the above equations (P1-A) to (P1-D), R 1 , R 2 , R 3 and R 4 Each of these independently represents a hydrogen atom, a halogen atom, a cyano group, a C1-C10 alkyl group, or a C1-C10 alkoxy group. The alkyl group may be a linear or branched alkyl group, or a cyclic alkyl group (cycloalkyl group). The number of carbon atoms in the alkyl group is preferably 1 to 5. The group represented by the above formula (P1-A) is preferably a unit of the partial structure of a poly(meth)acrylic acid ester obtained by polymerization of (meth)acrylic acid esters. The group represented by the above formula (P1-B) is preferably an ethylene glycol unit formed by ring-opening polymerization of an epoxy group of a compound having an epoxy group. The group represented by the above formula (P1-C) is preferably a propylene glycol unit formed by ring-opening polymerization of an oxetane group of a compound having an oxetane group. The group represented by the above formula (P1-D) is preferably a siloxane unit of polysiloxane obtained by polycondensation of a compound having at least one of an alkoxysilyl group and a silanol group. Here, as the compound having at least one of an alkoxysilyl group and a silanol group, there is a compound having a group represented by the formula SiR 14 (OR 15 )2-. In the formula, R 14 is synonymous with R 14 in (P1-D), and a plurality of R 15 each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

[0059] In the above formula (1), L1 is a single bond or a divalent linking group. Examples of the divalent linking group represented by L1 include -C(O)O-, -O-, -S-, -C(O)NR 3 -, -SO2-, and -NR 3 R 4 -. In the formula, R 3 and R 4 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent. When P1 is a group represented by the formula (P1-A), from the viewpoint that the degree of orientation of the light absorption anisotropic film becomes higher, L1 is preferably a group represented by -C(O)O-. When P1 is a group represented by the formulas (P1-B) to (P1-D), from the viewpoint that the degree of orientation of the light absorption anisotropic film becomes higher, L1 is preferably a single bond.

[0060] In the above formula (1), the spacer group represented by SP1 preferably includes at least one structure selected from the group consisting of an oxyethylene structure, an oxypropylene structure, a polysiloxane structure, and a fluorinated alkylene structure, due to its ease of exhibiting liquid crystalline properties and the availability of raw materials. Here, the oxyethylene structure represented by SP1 is *-(CH2-CH2O) n1 A group represented by -* is preferred. In the formula, n1 represents an integer from 1 to 20, and * represents the bonding position with L1 or M1 in formula (1) above. n1 is preferably an integer from 2 to 10, more preferably an integer from 2 to 4, and even more preferably 3, from the viewpoint of increasing the degree of orientation of the light-absorbing anisotropic film. Furthermore, the oxypropylene structure represented by SP1 is *-(CH(CH3)-CH2O) because it results in a higher degree of orientation of the light-absorbing anisotropic film. n2 A base represented by -* is preferred. In the formula, n2 represents an integer from 1 to 3, and * represents the bonding position with L1 or M1. Furthermore, the polysiloxane structure represented by SP1 is *-(Si(CH3)2-O) because it has a higher degree of orientation of the light-absorbing anisotropic film. n3 A base represented by -* is preferred. In the formula, n3 represents an integer between 6 and 10, and * represents the bonding position with L1 or M1. Furthermore, the alkylene fluoride structure represented by SP1 has a higher degree of orientation of the light-absorbing anisotropic film, hence *-(CF2-CF2) n4 A base represented by -* is preferred. In the formula, n4 represents an integer between 6 and 10, and * represents the bonding position with L1 or M1.

[0061] In formula (1) above, the mesogenic group represented by M1 is the group that represents the main skeleton of the liquid crystal molecule that contributes to liquid crystal formation. Liquid crystal molecules exhibit liquid crystalline properties, which is an intermediate state (mesophase) between the crystalline state and the isotropic liquid state. There are no particular restrictions on the mesogenic group; for example, refer to "Flussige Kristalle in Tabellen II" (VEB Deutsche Verlag fur Grundstoff Industrie, Leipzig, 1984) (especially the description on pages 7 to 16) and the Liquid Crystal Handbook (Maruzen, 2000), edited by the Liquid Crystal Handbook Editorial Committee (especially the description in Chapter 3). As the mesogenic group, a group having at least one cyclic structure selected from the group consisting of aromatic hydrocarbon groups, heterocyclic groups, and alicyclic groups is preferred. The mesogenic group preferably has aromatic hydrocarbon groups, more preferably has 2 to 4 aromatic hydrocarbon groups, and even more preferably has 3 aromatic hydrocarbon groups, in order to increase the degree of orientation of the light-absorbing anisotropic film.

[0062] As for the mesogenic group, a group represented by the following formula (M1-A) or formula (M1-B) is preferred, and the group represented by formula (M1-B) is more preferred, in terms of the emergence of liquid crystalline properties, adjustment of the liquid crystalline phase transition temperature, availability of raw materials and suitability for synthesis, and the degree of orientation of the light-absorbing anisotropic film being higher.

[0063] [ka]

[0064] In formula (M1-A), A1 is a divalent group selected from the group consisting of aromatic hydrocarbon groups, heterocyclic groups, and alicyclic groups. These groups may be substituted with alkyl groups, alkyl fluoride groups, alkoxy groups, or substituents. The divalent group represented by A1 is preferably a 4- to 6-membered ring. Furthermore, the divalent group represented by A1 may be a monoring or a fused ring. * indicates the binding site with SP1 or T1.

[0065] Examples of the divalent aromatic hydrocarbon group represented by A1 include phenylene, naphthylene, fluorene-diyl, anthracene-diyl, and tetracene-diyl groups. From the standpoint of versatility in designing the mesogenic skeleton and the availability of raw materials, the phenylene or naphthylene group is preferred, with the phenylene group being more preferred.

[0066] The divalent heterocyclic group represented by A1 may be either aromatic or non-aromatic, but it is preferable that it be a divalent aromatic heterocyclic group because it provides a higher degree of orientation. Atoms other than carbon that constitute a divalent aromatic heterocyclic group include nitrogen, sulfur, and oxygen atoms. If an aromatic heterocyclic group has multiple atoms other than carbon that constitute the ring, these may be the same or different. Specific examples of divalent aromatic heterocyclic groups include, for example, pyridylene (pyridine-diyl group), pyridazine-diyl group, imidazole-diyl group, thienylene (thiophene-diyl group), quinolylene (quinoline-diyl group), isoquinolylene (isoquinoline-diyl group), oxazole-diyl group, thiazole-diyl group, oxadiazole-diyl group, benzothiazole-diyl group, benzothiadiazole-diyl group, phthalimide-diyl group, thienothiazole-diyl group, thiazolothiazole-diyl group, thienothiophene-diyl group, and thienoxazole-diyl group.

[0067] Specific examples of the divalent alicyclic group represented by A1 include the cyclopentylene group and the cyclohexylene group.

[0068] In equation (M1-A), a1 represents an integer between 1 and 10. If a1 is 2 or greater, multiple A1s may be the same or different.

[0069] In formula (M1-B), A2 and A3 are each independently divalent groups selected from the group consisting of aromatic hydrocarbon groups, heterocyclic groups, and alicyclic groups. Specific examples and preferred embodiments of A2 and A3 are the same as those for A1 in formula (M1-A), so their explanation is omitted. In formula (M1-B), a2 represents an integer from 1 to 10. When a2 is 2 or greater, multiple A2s may be the same or different, multiple A3s may be the same or different, and multiple LA1s may be the same or different. a2 is preferably an integer of 2 or greater, and more preferably 2, from the viewpoint of increasing the degree of orientation of the light-absorbing anisotropic film. In formula (M1-B), when a2 is 1, LA1 is a divalent linking group. When a2 is 2 or more, each of the multiple LA1s is independently either a single bond or a divalent linking group, and at least one of the multiple LA1s is a divalent linking group. When a2 is 2, it is preferable that one of the two LA1s is a divalent linking group and the other is a single bond, as this results in a higher degree of orientation of the light-absorbing anisotropic film.

[0070] In formula (M1-B), the divalent linking group represented by LA1 is -O-, -(CH2) g -,-(CF2) g -, -Si(CH3)2-, -(Si(CH3)2O) g -,-(OSi(CH3)2) g-(g represents an integer from 1 to 10.), -N(Z)-, -C(Z)=C(Z')-, -C(Z)=N-, -C(Z)2-C(Z')2-, -C(O)-, -OC(O)-, -OC(O )O-, -N(Z)C(O)-, -C(Z)=C(Z')-C(O)O-, -C(Z)=N-, -C(Z)=C(Z')-C(O)N(Z")-, -C(Z)=C(Z')-C(O) Examples include -S-, -C(Z)=NN=C(Z')- (where Z, Z', and Z'' independently represent a hydrogen atom, a C1-C4 alkyl group, a cycloalkyl group, an aryl group, a cyano group, or a halogen atom), -C≡C-, -N=N-, -S-, -S(O)-, -S(O)(O)-, -(O)S(O)O-, -O(O)S(O)O-, and -SC(O). Among these, -C(O)O- is preferred because it results in a higher degree of orientation of the light-absorbing anisotropic film. LA1 may be a group formed by combining two or more of these groups.

[0071] In formula (1) above, the terminal group represented by T1 can be a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxyl group, a C1-C10 alkyl group, a C1-C10 alkoxy group, a C1-C10 alkylthio group, a C1-C10 alkoxycarbonyloxy group, a C1-C10 alkoxycarbonyl group (ROC(O)-: R is an alkyl group), a C1-C10 acyloxy group, a C1-C10 acylamino group, a C1-C10 alkoxycarbonylamino group, a C1-C10 sulfonylamino group, a C1-C10 sulfamoyl group, a C1-C10 carbamoyl group, a C1-C10 sulfinyl group, a C1-C10 ureido group, and a (meth)acryloyloxy group-containing group. Examples of the (meth)acryloyloxy group-containing groups mentioned above include the group represented by -LA (where L is a single bond or a linking group; specific examples of linking groups are the same as those for L1 and SP1 above; A represents the (meth)acryloyloxy group).

[0072] T1 is preferably an alkoxy group having 1 to 10 carbon atoms, more preferably an alkoxy group having 1 to 5 carbon atoms, and even more preferably a methoxy group, as this results in a higher degree of orientation of the light-absorbing anisotropic film. These terminal groups may be further substituted with these groups or with polymerizable groups described in Japanese Patent Application Publication No. 2010-244038.

[0073] T1 is preferably a polymerizable group because it allows for better adhesion to adjacent layers and improves the cohesive strength of the film. The polymerizable group is not particularly limited, but a polymerizable group capable of radical polymerization or cationic polymerization is preferred. As the radical polymerizable group, known polymerizable groups can be used, with acryloyl or methacryloyl groups being preferred. In this case, the polymerization rate is known to be faster with the acryloyl group, and from the viewpoint of improving productivity, the acryloyl group is preferred, but the methacryloyl group can also be used as a polymerizable group in the same way. Known cationic polymerizable groups can be used as the cationic polymerizable group, including, for example, alicyclic ether groups, cyclic acetal groups, cyclic lactone groups, cyclic thioether groups, spiroorthoester groups, and vinyloxy groups. Among these, alicyclic ether groups or vinyloxy groups are preferred, and epoxy groups, oxetanyl groups, or vinyloxy groups are preferred.

[0074] The weight-average molecular weight (Mw) of the polymer liquid crystal compound containing the repeating unit represented by formula (1) above is preferably 1,000 to 500,000, and more preferably 2,000 to 300,000, from the viewpoint of achieving a higher degree of orientation of the light-absorbing anisotropic film. If the Mw of the polymer liquid crystal compound is within the above range, the polymer liquid crystal compound becomes easier to handle. In particular, from the viewpoint of suppressing cracks during coating, the weight-average molecular weight (Mw) of the polymer liquid crystal compound is preferably 10,000 or more, and more preferably between 10,000 and 300,000. Furthermore, from the viewpoint of the temperature latitude of the degree of orientation, the weight-average molecular weight (Mw) of the polymer liquid crystal compound is preferably less than 10,000, and preferably between 2,000 and 10,000. Here, the weight-average molecular weight and number-average molecular weight used herein are values ​​measured by gel permeation chromatography (GPC). • Solvent (eluent): N-methylpyrrolidone ·Device name: TOSOH HLC-8220GPC • Column: Three TOSOH TSKgelSuperAWM-H (6mm x 15cm) columns connected together are used. • Column temperature: 25℃ • Sample concentration: 0.1% by mass ·Flow rate: 0.35mL / min • Calibration curve: A calibration curve was used based on 7 samples of TOSOH TSK standard polystyrene with Mw=2,800,000 to 1,050 (Mw / Mn=1.03 to 1.06).

[0075] The liquid crystal compound may be used alone or in combination of two or more. Preferably, this light-absorbing anisotropic film contains two or more liquid crystal compounds. The content of the liquid crystal compound in the light-absorbing anisotropic film is preferably 50 to 99% by mass, and more preferably 75 to 90% by mass, relative to the total mass of the light-absorbing anisotropic film, in terms of achieving superior effects of the present invention.

[0076] (Other ingredients) The light-absorbing anisotropic film may contain other components besides those described above. Examples of other components include interface modifiers, vertical alignment agents, and leveling agents.

[0077] -Interface modifier- The interface modifier included in the light-absorbing anisotropic film is not particularly limited, and known polymer-based interface modifiers and low-molecular-weight interface modifiers can be used. As an interface modifier, compounds described in paragraphs

[0253] to

[0293] of Japanese Patent Publication No. 2011-237513 can be used. Furthermore, as an interface modifier, fluorine (meth)acrylate polymers described in paragraphs

[0018] to

[0043] of Japanese Patent Application Publication No. 2007-272185 can also be used. Furthermore, as interface modifiers, the compounds described in paragraphs

[0079] to

[0102] of Japanese Patent Publication No. 2007-069471, polymerizable liquid crystalline compounds represented by formula (4) described in Japanese Patent Publication No. 2013-047204 (particularly the compounds described in paragraphs

[0020] to

[0032] ), polymerizable liquid crystalline compounds represented by formula (4) described in Japanese Patent Publication No. 2012-211306 (particularly the compounds described in paragraphs

[0022] to

[0029] ), and liquid crystal alignment promoters represented by formula (4) described in Japanese Patent Publication No. 2002-129162 (particularly

[0076] to

[0032] ) are also used.

[0078] Compounds described in paragraphs

[0082] to

[0084] , compounds represented by formulas (4), (II), and (III) described in Japanese Patent Publication No. 2005-099248 (particularly the compounds described in paragraphs

[0092] to

[0096] ), compounds described in paragraphs

[0013] to

[0059] of Japanese Patent No. 4385997, compounds described in paragraphs

[0018] to

[0044] of Japanese Patent No. 5034200, and compounds described in paragraphs

[0019] to

[0038] of Japanese Patent No. 4895088 can also be used.

[0078] The interface modifier may be used alone or in combination of two or more types. When the light-absorbing anisotropic film contains an interface modifier, the content of the interface modifier is preferably 0.001 to 5 parts by mass per 100 parts by mass of the total of the dichroic substance and the liquid crystalline compound. When multiple interface modifiers are used in combination, it is preferable that the total amount of the multiple interface modifiers is within the above range.

[0079] -Vertical alignment agent- Examples of vertical orientation agents include boronic acid compounds and onium salts. As the boronic acid compound, the compound represented by formula (A) is preferred.

[0080] Formula (A) [ka]

[0081] In formula (A), R 1 and R 2Each of these independently represents a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group. R 3 This represents a substituent containing a (meth)acrylic group. Specific examples of boronic acid compounds include the boronic acid compounds represented by general formula (I) described in paragraphs

[0023] to

[0032] of Japanese Patent Publication No. 2008-225281. The following compounds are also preferred as boronic acid compounds.

[0082] [ka]

[0083] As the onium salt, the compound represented by formula (B) is preferred. Formula (B) [ka]

[0084] In formula (B), ring A represents a quaternary ammonium ion consisting of a nitrogen-containing heterocycle. - L represents an anion. 1 This represents a divalent linking group. 2 This represents a single bond or a divalent linking group. 1 represents a divalent linking group having a 5 or 6-membered ring as a substructure. Z represents a divalent linking group having 2 to 20 alkylene groups as a substructure. P 1 and P 2 Each of these independently represents a monovalent substituent having a polymerizable ethylenically unsaturated bond. Specific examples of onium salts include the onium salt described in paragraphs

[0052] to

[0058] of Japanese Patent Publication No. 2012-208397, the onium salt described in paragraphs

[0024] to

[0055] of Japanese Patent Publication No. 2008-026730, and the onium salt described in Japanese Patent Publication No. 2002-037777.

[0085] When the light-absorbing anisotropic film contains a liquid crystal compound and a vertical alignment agent, the content of the vertical alignment agent is preferably 0.1 to 400% by mass, and more preferably 0.5 to 350% by mass, relative to the total mass of the liquid crystal compound. Vertical alignment agents may be used individually or in combination of two or more types. When two or more vertical alignment agents are used, it is preferable that their total amount is within the above range.

[0086] - Leveling agent - The light-absorbing anisotropic film may contain a leveling agent. When the light-absorbing anisotropic film-forming composition (light-absorbing anisotropic film) described later contains a leveling agent, surface roughness caused by drying air on the surface of the light-absorbing anisotropic film is suppressed, and the dichroic substances are oriented more uniformly. The leveling agent is not particularly limited, but a leveling agent containing a fluorine atom (fluorine-based leveling agent) or a leveling agent containing a silicon atom (silicon-based leveling agent) is preferred, and a fluorine-based leveling agent is more preferred.

[0087] Examples of fluorine-based leveling agents include fatty acid esters of polycarboxylic acids in which a portion of the fatty acid is substituted with a fluoroalkyl group, and polyacrylates having fluoro substituents. Specific examples of leveling agents include the compounds exemplified in paragraphs

[0046] to

[0052] of Japanese Patent Publication No. 2004-331812, and the compounds described in paragraphs

[0038] to

[0052] of Japanese Patent Publication No. 2008-257205.

[0088] When the light-absorbing anisotropic film contains a liquid crystal compound and a leveling agent, the content of the leveling agent is preferably 0.001 to 10% by mass, and more preferably 0.01 to 5% by mass, relative to the total mass of the liquid crystal compound. Leveling agents may be used individually or in combination of two or more types. When using two or more types of leveling agents, it is preferable that their total amount is within the above range.

[0089] (Composition for forming light-absorbing anisotropic films) The light-absorbing anisotropic film is preferably formed using a light-absorbing anisotropic film-forming composition containing a dichroic substance and a liquid crystal compound. The composition for forming a light-absorbing anisotropic film preferably contains a dichroic substance and a liquid crystal compound, in addition to a solvent described later. The composition for forming a light-absorbing anisotropic film may further contain other components. Other components include, for example, the above-mentioned interface modifier, vertical orientation agent, leveling agent, polymerization initiator described later, and polymerizable component described later.

[0090] Examples of dichroic substances included in compositions for forming light-absorbing anisotropic films include dichroic substances included in light-absorbing anisotropic films. The content of dichroic substances relative to the total solid content mass of the light-absorbing anisotropic film-forming composition is preferably the same as the content of dichroic substances relative to the total mass of the light-absorbing anisotropic film. Here, "total solid content in a light-absorbing anisotropic film-forming composition" refers to the components excluding the solvent. Specific examples of solid content include dichroic substances, liquid crystal compounds, and the other components mentioned above.

[0091] The liquid crystal compounds, interface modifiers, vertical alignment agents, and leveling agents contained in the light-absorbing anisotropic film-forming composition are the same as those contained in the light-absorbing anisotropic film. Preferably, the content of the liquid crystal compound, interface modifier, vertical alignment agent, and leveling agent relative to the total solid content mass of the light-absorbing anisotropic film-forming composition is the same as the content of the liquid crystal compound, interface modifier, vertical alignment agent, and leveling agent relative to the total mass of the light-absorbing anisotropic film.

[0092] Compositions for forming light-absorbing anisotropic films preferably contain a solvent from the viewpoint of workability. Examples of solvents include organic solvents such as ketones, ethers, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, carbon halides, esters, alcohols, cellosolves, cellosolve acetates, sulfoxides, amides, and heterocyclic compounds, as well as water. These solvents may be used individually or in combination of two or more. Of these solvents, organic solvents are preferred, and carbon halides or ketones are more preferred.

[0093] If the light-absorbing anisotropic film-forming composition contains a solvent, the solvent content is preferably 80 to 99% by mass, more preferably 83 to 97% by mass, and even more preferably 85 to 95% by mass, based on the total mass of the light-absorbing anisotropic film-forming composition.

[0094] The light-absorbing anisotropic film-forming composition may contain a polymerization initiator. There are no particular restrictions on the polymerization initiator, but it is preferable that it be a photosensitive compound, i.e., a photopolymerization initiator. Commercially available photopolymerization initiators can also be used, including BASF's Irgacure® 184, Irgacure 907, Irgacure 369, Irgacure 651, Irgacure 819, Irgacure OXE-01, and Irgacure OXE-02. Polymerization initiators may be used individually or in combination of two or more. When the light-absorbing anisotropic film-forming composition contains a polymerization initiator, the content of the polymerization initiator is preferably 0.01 to 30% by mass, and more preferably 0.1 to 15% by mass, relative to the total solid content of the light-absorbing anisotropic film-forming composition.

[0095] The light-absorbing anisotropic film-forming composition may contain polymerizable components. Examples of polymerizable components include compounds containing acrylates (e.g., acrylate monomers). When using compounds containing acrylates, the light-absorbing anisotropic film contains polyacrylate obtained by polymerizing the above-mentioned acrylate-containing compounds. Furthermore, examples of polymerizable components include the compounds described in paragraph

[0058] of Japanese Patent Publication No. 2017-122776. When the light-absorbing anisotropic film-forming composition contains polymerizable components, the amount of polymerizable components is preferably 3 to 20 parts by mass per 100 parts by mass of the total of the dichroic substance and the liquid crystalline compound in the light-absorbing anisotropic film-forming composition.

[0096] [Method for manufacturing light-absorbing anisotropic films] The method for manufacturing a light-absorbing anisotropic film is not particularly limited as long as it is a method that can form a light-absorbing anisotropic film that satisfies the above requirements 1 to 3, by arranging multiple regions in the in-plane direction in which the direction of the transmittance central axis differs, and known manufacturing methods can be applied. A method for manufacturing a light-absorbing anisotropic film includes, in this order, a step of forming an alignment film having multiple regions with different orientation-regulating forces in the in-plane direction (hereinafter also referred to as a "specific alignment film") (hereinafter also referred to as a "specific alignment film formation step"), a step of applying the above-mentioned light-absorbing anisotropic film forming composition onto the obtained specific alignment film to form a coated film (hereinafter also referred to as a "coated film formation step"), and a step of aligning the liquid crystalline components contained in the coated film (hereinafter also referred to as an "alignment step"). Furthermore, liquid crystalline components include not only the liquid crystal compounds mentioned above, but also dichroic substances that possess liquid crystalline properties. The method for manufacturing a light-absorbing anisotropic film will be described below using the above-described method comprising the specific orientation film formation step, coating film formation step, and orientation step as an example, but the method for manufacturing a light-absorbing anisotropic film is not limited to the method described below.

[0097] <Specific alignment film formation process> The specific orientation film formation step is a step in which a specific orientation film is formed having an orientation restricting force that aligns liquid crystalline components that may be contained in a light-absorbing anisotropic film formation composition, and in which multiple regions with different directions of orientation restricting force are arranged in the plane. Methods for forming a specific orientation film include, for example, rubbing the film surface with an organic compound (preferably a polymer), forming a layer having microgrooves, and imparting an orientation function by applying an electric field, a magnetic field, or light irradiation. As for the specific orientation film formation process, it is preferable to form the orientation film by rubbing treatment from the viewpoint of ease of controlling the pre-tilt angle of the orientation film, and it is preferable to form the photo-alignment film by light irradiation from the viewpoint of uniformity of orientation and ease of forming multiple regions with different directions of orientation restricting force, and it is more preferable to form the photo-alignment film.

[0098] The photo-alignment film formed by light irradiation is not particularly limited as long as it is an alignment film to which an alignment restricting force in a predetermined direction is applied. The material for forming the photo-alignment film is not particularly limited, but the photo-alignment film is formed using, for example, a photo-alignment film forming composition containing a photo-alignment agent.

[0099] The photo-orienting agent is a compound having a photo-orienting group, and is not particularly limited as long as it is a material to which orientation-regulating force is imparted by the orientation treatment described later. Examples of photo-orienting groups include groups that have a photo-orienting function in which rearrangement or anisotropic chemical reactions are induced by irradiation with anisotropic light (e.g., plane-polarized light). In other words, a photo-orienting group is a group in which at least one photoreaction selected from photoisomerization, photodimerization, and photodecomposition reactions is triggered by irradiation with light (e.g., linearly polarized light), and a change occurs in the molecular structure within the group. Among these, groups that undergo photoisomerization (groups having a photoisomerizing structure) or groups that undergo photodimerization (groups having a photodimerizing structure) are preferred because they exhibit excellent orientation uniformity and good thermal and chemical stability.

[0100] Photoisomerization is a reaction that causes stereoisomerization or structural isomerization through the action of light. Examples of photo-orienting agents having groups that cause photoisomerization reactions include substances with an azobenzene structure (K. Ichimura et al., Mol.Cryst.Liq.Cryst., 298, page 221 (1997)), substances with a hydrazono-β-ketoester structure (S. Yamamura et al., Liquid Crystals, vol. 13, No. 2, page 189 (1993)), substances with a stilbene structure (JGVictor and JMTorkelson, Macromolecules, 20, page 2241 (1987)), groups with a cinnamic acid (cinnamoyl) structure (skeleton), and substances with a spiropyran structure (K. Ichimura et al., Chemistry Letters, page 1063 (1992); K.Ichimura et al., Thin Solid Films, vol. 235, page 101) (1993)) is a well-known example. The groups that undergo photoisomerization reactions are preferably those that contain a C=C bond or an N=N bond. Examples of such groups include groups having an azobenzene structure (skeleton), a hydrazono-β-ketoester structure (skeleton), a stilbene structure (skeleton), a cinnamic acid (cinnamoyl) structure (skeleton), and a spiropyran structure (skeleton). Among these, groups having an azobenzene structure, a cinnamoyl structure, or a coumarin structure are preferred, and groups having an azobenzene structure or a cinnamoyl structure are more preferred.

[0101] The above-mentioned photodimerization reaction refers to a reaction in which an addition reaction occurs between two groups due to the action of light, typically forming a ring structure. Examples of photo-orienting agents that have groups that cause photodimerization include substances with a cinnamic acid structure (M. Schadt et al., J. Appl. Phys., vol. 31, No. 7, page 2155 (1992)), substances with a coumarin structure (M. Schadt et al., Nature., vol. 381, page 212 (1996)), substances with a chalcone structure (Toshihiro Ogawa et al., Proceedings of the Liquid Crystal Symposium, 2AB03 (1997)), and substances with a benzophenone structure (YK Jang et al., SID Int. Symposium Digest, P-53 (1997)). Groups that undergo photodimerization reactions include, for example, groups having a cinnamic acid (cinnamoyl) structure (skeleton), a coumarin structure (skeleton), a chalcone structure (skeleton), a benzophenone structure (skeleton), and an anthracene structure (skeleton). Among these, groups having a cinnamoyl structure or a coumarin structure are preferred, and groups having a cinnamoyl structure are more preferred.

[0102] The photo-orienting agent preferably further has a crosslinking group. Preferred crosslinkable groups include thermally crosslinkable groups that undergo a curing reaction upon the action of heat, and photocrosslinkable groups that undergo a curing reaction upon the action of light. Crosslinkable groups may also include those having both thermal and photocrosslinkable properties. More specifically, examples of crosslinkable groups include hydroxyl groups, carboxyl groups, amino groups, radical polymerizable groups (e.g., acryloyl groups, methacryloyl groups, vinyl groups, styryl groups, and allyl groups), and cationic polymerizable groups (e.g., epoxy groups, epoxycyclohexyl groups, and oxetanyl groups).

[0103] As a photo-aligning agent, polymers having photo-aligning groups can also be preferably used, and from the viewpoint of ensuring close adhesion between the photo-aligning film and the light-absorbing anisotropic film, polymers having photo-aligning groups that have hydrophobicity similar to that of the light-absorbing anisotropic film are more preferable. Examples of polymers having photo-orienting groups include photo-orienting acrylate polymers described in Japanese Patent Publication No. 6-289374, Japanese Patent Publication No. 10-506420, Japanese Patent Publication No. 2009-501238, Japanese Patent Publication No. 2012-078421, Japanese Patent Publication No. 2015-106062, Japanese Patent Publication No. 2016-079189, and Japanese Patent Publication No. 2012-037868 and Japanese Patent Publication No. 2014-026261. Examples include photo-oriented polysiloxanes described in Japanese Patent Publication No. 2015-026050, photo-oriented polystyrene-acrylate copolymers described in Japanese Patent Publication Nos. 2015-151548, 2015-151549, and 2016-098249, and photo-oriented polynorbornene polymers described in Japanese Patent Publication No. 2012-027471 and Japanese Patent Publication No. 2015-533883.

[0104] The content of the orientation agent in the photo-alignment film-forming composition is not particularly limited, but is preferably 0.1 to 50 parts by mass, and more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the solvent described later.

[0105] From the viewpoint of ease of production of the photo-alignment film, the composition for forming the photo-alignment film preferably contains a solvent. Examples of solvents include water and organic solvents. Examples of organic solvents include organic solvents that may be included in the above-mentioned composition for forming a light-absorbing anisotropic layer. The solvent may be used alone or in combination of two or more types.

[0106] The photo-alignment film-forming composition may contain other components besides those mentioned above. Examples of other components include acid generators, crosslinking catalysts, adhesion improvers, leveling agents, surfactants, and plasticizers.

[0107] The following describes a method for forming a specific orientation film by light irradiation, with reference to the drawings. The method for forming a specific orientation film by light irradiation is not particularly limited. For example, a method may be described as comprising a coating process in which the above-mentioned photo-alignment film-forming composition is applied to the surface of a substrate to form a coating film, and a photo-alignment process in which the formed coating film is irradiated with polarized or unpolarized light to form a specific orientation film.

[0108] (Coating treatment) The coating process is a step in which a photo-alignment film-forming composition is applied to the surface of a substrate to form a coated film. The method for applying the photo-alignment film-forming composition is not limited and includes, for example, roll coating, gravure printing, spin coating, wire bar coating, extrusion coating, direct gravure coating, reverse gravure coating, die coating, spray, and inkjet methods. In the coating process, a transparent resin film, described later, can be used as a substrate to which the photo-alignment film-forming composition is applied.

[0109] (Photo-alignment treatment) A specific orientation film is formed by applying a photo-orientation treatment to a coated film formed by a coating process, which involves irradiating it with polarized or unpolarized light. Various light sources can be used for the photo-alignment process, including infrared, visible light, or ultraviolet light, but ultraviolet light is preferred. When polarized light is irradiated during the photo-alignment treatment, the irradiation direction may be normal to the surface of the coated film, or it may be oblique to the surface of the coated film. When unpolarized light is irradiated during the photo-alignment treatment, the irradiation direction is oblique to the surface of the coated film.

[0110] The photo-alignment treatment is a process that forms an oriented film having multiple regions with different orientation-regulating forces by irradiating the above-mentioned coated film with polarized or unpolarized light whose incident direction on the coated film differs depending on the position within the plane. In photo-alignment treatment, it is preferable to use polarized light, and more preferable to use polarized ultraviolet light.

[0111] The photo-alignment process will be explained in more detail with reference to Figures 5A, 5B, and 5C (hereinafter collectively referred to as "Figure 5"). Figure 5 is a conceptual diagram showing one embodiment of the photo-alignment treatment of a coated film with an alignment film-forming composition. The X, Y, Z axes, angles θ and φ shown in Figures 5 to 7 are as already described in the explanation of Figure 1.

[0112] Figure 5 is a perspective view of the coated film 50 of the orientation film-forming composition formed by the above coating process, observed from an oblique angle above. The coated film 50 is formed on the surface of a substrate (not shown). As shown in Figure 5A, the coated film 50 is divided into two regions by boundary lines L that are equidistant from both ends in the X-axis direction: a first region 51 on the negative X-axis side (left side of the paper) and a second region 52 on the positive X-axis side (right side of the paper). As part of the photo-alignment process, first, as shown in Figure 5B, a mask M is placed so as to cover the upper part of the second region 52 of the coated film 50, thereby shielding only the second region 52 from light and exposing the first region 51. Polarized light is then shone onto the exposed first region 51 from a first direction. In Figure 5B, the first direction is the positive direction of the Z axis (direction with angle θ = 0°). Next, as shown in Figure 5C, the mask M is moved to a position that covers the upper part of the first region 51, thereby shielding only the first region 51 and exposing the second region 52. Polarized light is then shone onto the exposed second region 52 from a second direction. In Figure 5C, the second direction is tilted 35° from the positive Z-axis toward the negative X-axis (angle θ=35° and angle φ=0°). After irradiating the second region 52, the mask M is removed, thereby forming a specific orientation film in the first region 51 and the second region 52, each with different orientation restricting force directions. By performing a coating film formation step and an orientation step on the specific orientation film formed by the above photo-orientation treatment, the light-absorbing anisotropic film 10 shown in Figure 1 is obtained.

[0113] In the photo-alignment process shown in Figure 5, light from different incident directions is irradiated onto each of the two regions formed by dividing the coated film 50 in the X-axis direction. However, the photo-alignment process is not limited to this configuration, and the coated film may be divided into three or more regions in plane, and light from different incident directions may be irradiated onto each region.

[0114] Figures 6A, 6B, and 6C (hereinafter collectively referred to as "Figure 6") are conceptual diagrams illustrating other examples of photo-alignment processing. Figure 6 is a perspective view of the coated film 60 of the orientation film-forming composition formed by the above coating process, observed from an oblique angle above. The coated film 60 is formed on the surface of a substrate (not shown). The coated film 60 shown in Figure 6 is divided into three regions in the X-axis direction, from the negative X-axis side: a first region 61, a second region 62, and a third region 63. As part of the photo-alignment process, first, as shown in Figure 6A, a mask M is placed so as to cover the second region 62 and the third region 63 of the coated film 60, thereby shielding the second region 62 and the third region 63 from light and exposing the first region 61. Polarized light is then shone onto the exposed first region 61 from a first direction. In Figure 6A, the first direction is the positive direction of the Z axis (direction with angle θ = 0°). Next, as shown in Figure 6B, two masks M are placed to cover the top of the first region 61 and the third region 63, respectively, thereby shielding the first region 61 and the third region 63 from light and exposing the second region 62. Polarized light is then shone onto the exposed second region 62 from a second direction. In Figure 6B, the second direction is tilted 15° from the positive Z-axis toward the negative X-axis (angle θ=15° and angle φ=0°). Next, as shown in Figure 6C, the mask M is positioned to cover the first region 61 and the second region 62, thereby shielding the first region 61 and the second region 62 from light and exposing the third region 63. Polarized light is then shone onto the exposed third region 63 from a third direction. In Figure 6C, the third direction is tilted 30° from the positive Z-axis toward the negative X-axis (angle θ=35° and angle φ=0°). After irradiating the third region 63, the mask M is removed, thereby forming a specific orientation film in each of the first region 61, second region 62, and third region 63, where the direction of the orientation restricting force is different. By performing a coating film formation step and an orientation step on the specific orientation film formed by the above photo-orientation treatment, the light-absorbing anisotropic film 20 shown in Figure 2 is obtained.

[0115] The photo-alignment treatment is not limited to a method for forming a specific alignment film in which the direction of the alignment restricting force changes stepwise depending on the position in the plane, as described above, but may also be a method for forming a specific alignment film in which the direction of the alignment restricting force changes continuously.

[0116] Another embodiment of the photo-alignment treatment will be described with reference to Figure 7. Figure 7 is a conceptual diagram showing another embodiment of the photo-alignment treatment, and is a front view of the coated film 70 of the alignment film-forming composition formed by the above coating treatment, observed from the negative direction of the Y-axis. The coated film 70 is formed on the surface of a substrate (not shown). As shown in Figure 7, the coated film 70 is bent into an inverted U-shape. Polarized light is irradiated onto the coated film 70, which has a convex surface on the positive Z-axis side (angle θ = 0°), from the positive Z-axis direction. As a result, the angle of incidence of the polarized light on the curved surface of the coated film 70 changes continuously depending on the position of the coated film 70 in the X-axis direction. After orientation, by returning the coated film 70 to a planar state, a specific orientation film is formed in which the direction of the orientation restricting force (angle θ) changes continuously along the X-axis direction. By performing a coating film formation step and an orientation step on the specific orientation film obtained above, the light-absorbing anisotropic film 30 shown in Figure 3 is obtained.

[0117] Other embodiments of the photo-alignment process will be described with reference to Figures 8A and 8B (hereinafter collectively referred to as "Figure 8"). The X-axis, Y-axis, Z-axis, angle θ, and angle φ shown in Figure 8 are as already described in the explanation of Figure 4.

[0118] Figure 8 is a conceptual diagram showing another embodiment of the photo-alignment process, and is a perspective view of the coated film 80 of the alignment film-forming composition formed by the above coating process, observed from an oblique angle above. The coated film 80 is formed on the surface of a substrate (not shown). The coated film 80 is divided into two regions by boundary lines equidistant from both ends in the Y-axis direction: a first region 81 on the positive Y-axis side (upper side of the paper) and a second region 82 on the negative Y-axis side (lower side of the paper). As part of the optical alignment process, first, as shown in Figure 8A, a mask M is placed so as to cover the upper part of the second region 82, thereby shielding only the second region 82 from light and exposing the first region 81. Polarized light is then shone onto the exposed first region 81 from a first direction. In Figure 8A, the first direction is the direction tilted 30° from the positive Z-axis toward the negative X-axis (the direction with angle θ=30° and angle φ=0°). Next, as shown in Figure 8B, the mask M is moved to a position that covers the upper part of the first region 81 of the coated film 80, thereby shielding only the first region 81 and exposing the second region 82. Polarized light is then shone onto the exposed second region 82 from a second direction. In Figure 8B, the second direction is the direction tilted 30° from the positive Z-axis toward the direction where the angle φ is 50° in the XY plane (the direction where the angle θ = 30°). After irradiating the second region 82, the mask M is removed, thereby forming a specific orientation film in the first region 81 and the second region 82, each with different orientation restricting force directions. By performing a coating film formation step and an orientation step on the specific orientation film formed by the above photo-orientation treatment, the light-absorbing anisotropic film 40 shown in Figure 4 is obtained.

[0119] The photo-alignment treatment is not limited to the embodiments shown in Figures 5 to 8 above, and can be appropriately selected depending on the arrangement of multiple regions with different transmittance center axes in the desired photo-absorbing anisotropic film.

[0120] The thickness of the specific orientation film formed by the specific orientation film formation process is not particularly limited, but is preferably 0.01 to 10 μm, and more preferably 0.01 to 1 μm.

[0121] <Coating film formation process> The coating film formation process involves applying a light-absorbing anisotropic film-forming composition to the surface of a specific orientation film to form a coated film. In this process, it is preferable to use a light-absorbing anisotropic film-forming composition containing the above-mentioned solvent, or a liquid such as a heated melt of the light-absorbing anisotropic film-forming composition. This is because it facilitates the application of the light-absorbing anisotropic film-forming composition onto the specific orientation film. Known methods for applying compositions for forming light-absorbing anisotropic films include roll coating, gravure printing, spin coating, wire bar coating, extrusion coating, direct gravure coating, reverse gravure coating, die coating, spray coating, and inkjet coating.

[0122] <Orientation Process> The orientation process is a process that aligns the liquid crystalline components (especially dichroic substances) contained in the coated film. In the orientation process, it is thought that the dichroic substances are oriented along the liquid crystalline compounds that have been oriented by the orientation-regulating force of the specific orientation film. The orientation step may include a drying process. The drying process can remove components such as solvents from the coating film. The drying process may be carried out by leaving the coating film at room temperature for a predetermined time (e.g., natural drying), or by heating and / or blowing air.

[0123] The orientation step preferably includes a heat treatment. This improves the orientation of the dichroic substances contained in the coating film, resulting in a higher degree of orientation of the resulting light-absorbing anisotropic film. From the standpoint of suitability for manufacturing, the heat treatment is preferably performed at 10 to 250°C, and more preferably at 25 to 190°C. The heating time is preferably 1 to 300 seconds, and more preferably 1 to 60 seconds.

[0124] The orientation step may include a cooling process performed after the heat treatment. The cooling process involves cooling the heated coating film to room temperature (approximately 20-25°C). This further fixes the orientation of the dichroic substances contained in the coating film, thereby increasing the degree of orientation of the light-absorbing anisotropic film. The cooling method is not particularly limited and can be carried out by known methods. The above process can be used to obtain this light-absorbing anisotropic film.

[0125] <Other processes> The method for manufacturing a light-absorbing anisotropic film may include a step of curing the light-absorbing anisotropic film (hereinafter also referred to as the "curing step") after the orientation step described above. The curing process is carried out, for example, by heating and / or light irradiation (exposure). In particular, it is preferable to carry out the curing process by light irradiation. Various light sources can be used for curing, such as infrared light, visible light, and ultraviolet light, with ultraviolet light being preferred. Furthermore, ultraviolet light may be irradiated while heating during curing, or ultraviolet light may be irradiated through a filter that transmits only specific wavelengths. Furthermore, exposure may be performed under a nitrogen atmosphere. When the curing of the light-absorbing anisotropic film proceeds by radical polymerization, exposure under a nitrogen atmosphere is preferable because it reduces the inhibition of polymerization by oxygen.

[0126] [Optical film] The optical film is a component having at least a light-absorbing anisotropic film according to the present invention. The optical film is preferably a laminated film in which an alignment film and a light-absorbing anisotropic film are laminated, and more preferably a laminated film in which a transparent substrate film, an alignment film, and a light-absorbing anisotropic film are laminated in this order.

[0127] (Transparent base film) The optical film may have a transparent substrate film. The transparent substrate film may be used as a substrate for forming a light-absorbing anisotropic film, or as a film to protect the light-absorbing anisotropic film. The transparent substrate film may also serve as a phase difference layer. The transparent substrate film is not particularly limited, and known transparent resin films, transparent resin plates, and transparent resin sheets can be used.

[0128] Preferred transparent resin films include cellulose acylate films (e.g., cellulose triacetate film (refractive index 1.48), cellulose diacetate film, cellulose acetate butyrate film, cellulose acetate propionate film), polyethylene terephthalate film, polyethersulfone film, polyurethane resin film, polyester film, polycarbonate film, polysulfone film, polyether film, polymethylpentene film, polyetherketone film, (meth)acrylonitrile film, cycloolefin polymer film (polymer film using cycloolefin polymers), polycarbonate polymer film, polystyrene polymer film, or acrylic polymer film. The acrylic polymer film preferably contains an acrylic polymer that includes at least one unit selected from lactone ring units, maleic anhydride units, and glutaric acid anhydride units. The thickness of the transparent substrate film is preferably 20 to 100 μm.

[0129] (Orientation film) The optical film may have an alignment film, and it is preferable that it has the above-mentioned specific alignment film. The specific form of the orientation film is as previously described as a specific orientation film.

[0130] The optical film may have layers other than the light-absorbing anisotropic film, the transparent substrate film, and the alignment film, and preferably further has a resin film containing polyvinyl alcohol or polyimide. The resin film may be disposed on one surface of the light-absorbing anisotropic layer, or on both surfaces of the light-absorbing anisotropic layer. A resin film containing polyvinyl alcohol or polyimide functions as a primer layer that improves the adhesion between two layers selected from the group consisting of a light-absorbing anisotropic film, a transparent substrate film, and an alignment film. Furthermore, the resin film also functions as a barrier layer, as described later. Examples of polyvinyl alcohol or polyimide contained in the resin film include polyvinyl alcohol, polyimide, or derivatives thereof known as polymer materials for orientation films, with modified or unmodified polyvinyl alcohol being preferred. The thickness of the resin film is not particularly limited, but is preferably 0.01 to 10 μm, and more preferably 0.01 to 1 μm.

[0131] The method for forming the resin film is not particularly limited. For example, a method may be used in which a resin composition containing polyvinyl alcohol or polyimide is applied to the surface of a light-absorbing anisotropic layer to form a coating film, and the formed coating film is cured to obtain a resin film. The method for forming the coating film is not particularly limited, and the method described as the coating treatment in the specific orientation film formation step above is an example. Furthermore, as a method for curing the coating film, for example, a method may be used in which the solvent contained in the coating film is removed by heating and / or drying the coating film to form a resin film.

[0132] [Visual Angle Control System] The viewing angle control system comprises a polarizer having an absorption axis in the in-plane direction and the above-mentioned light-absorbing anisotropic film or the above-mentioned optical film. In particular, if this light-absorbing anisotropic film satisfies requirement 3, it is preferable to use it in combination with a polarizer in an image display device, as this allows for a greater controllability of the viewing angle.

[0133] (Polarizer) The polarizer used in the viewing angle control system is not particularly limited as long as it has an absorption axis in the in-plane direction and a function to convert light into a specific linear polarization; conventionally known polarizers can be used. Examples of polarizers include iodine-based polarizers, dye-based polarizers utilizing dichroic dyes, and polyene-based polarizers. Iodine-based and dye-based polarizers include coated polarizers and stretched polarizers, both of which are applicable. For coated polarizers, polarizers in which dichroic organic dyes are oriented using the orientation of liquid crystal compounds are preferred, and for stretched polarizers, polarizers made by adsorbing iodine or a dichroic dye onto polyvinyl alcohol and then stretching it are preferred. Furthermore, methods for obtaining polarizers by stretching and dyeing a laminated film in which a polyvinyl alcohol layer is formed on a substrate include the methods described in Japanese Patent Publication No. 5048120, Japanese Patent Publication No. 5143918, Japanese Patent Publication No. 5048120, Japanese Patent Publication No. 4691205, Japanese Patent Publication No. 4751481, and Japanese Patent Publication No. 4751486, and these known technologies related to polarizers can also be preferably utilized.

[0134] In particular, polarizers containing polyvinyl alcohol-based resin (polymers containing -CH2-CHOH- as repeating units; at least one selected from the group consisting of polyvinyl alcohol and ethylene-vinyl alcohol copolymers) are preferred because they are readily available and have excellent polarization properties.

[0135] The thickness of the polarizer is not particularly limited, but is preferably 3 to 60 μm, more preferably 5 to 20 μm, and even more preferably 5 to 10 μm.

[0136] (Other components) The viewing angle control system may include other components besides those mentioned above, such as an adhesive layer, bonding layer, optical anisotropy film, refractive index adjustment layer, and barrier layer. The viewing angle control system may be manufactured by laminating the above-mentioned light-absorbing anisotropic film or optical film with the polarizer via an adhesive layer or bonding layer described later. Alternatively, the viewing angle control system may be manufactured by directly laminating the above-mentioned alignment film and light-absorbing anisotropic film onto the polarizer.

[0137] (Adhesive layer) The adhesive layer is preferably a transparent, optically isotropic adhesive similar to those used in typical image display devices, and a pressure-sensitive adhesive is usually used.

[0138] The adhesive layer includes, for example, a base material (adhesive), conductive particles, and thermally expandable particles used as needed. In addition to the above components, the adhesive layer may also contain additives such as crosslinking agents (e.g., isocyanate-based crosslinking agents, epoxy-based crosslinking agents, etc.), tackifiers (e.g., rosin derivative resins, polyterpene resins, petroleum resins, oil-soluble phenolic resins, etc.), plasticizers, fillers, antioxidants, surfactants, UV absorbers, light stabilizers, and antioxidants.

[0139] The thickness of the adhesive layer is, for example, 20 to 500 μm, with 20 to 250 μm being preferred. A thickness of 20 μm or more provides excellent adhesive strength and reworkability, while a thickness of 500 μm or less further suppresses the overflow or seepage of the adhesive from the peripheral edges of the image display device. Methods for forming the adhesive layer include, for example, applying a coating liquid containing the above components and solvent directly onto a support for the protective member and pressing it onto the support via a release liner, and applying a coating liquid onto a suitable release liner (such as release paper) to form a thermally expandable adhesive layer, and then pressing and transferring (depositionting) it onto the support for the protective member.

[0140] In addition, as a protective member, for example, a configuration in which conductive particles are added to a heat-removable adhesive sheet as described in Japanese Patent Publication No. 2003-292916 can be applied. Alternatively, as a protective material, a commercially available product such as "Riva Alpha" manufactured by Nitto Denko Corporation, in which conductive particles are scattered on the surface of the adhesive layer, may be used.

[0141] [Adhesive layer] The adhesive layer contains at least an adhesive. The adhesive develops its adhesive properties through drying and reaction after bonding. Polyvinyl alcohol-based adhesives (PVA-based adhesives) develop their adhesive properties upon drying, making it possible to bond materials together. Specific examples of curable adhesives that exhibit adhesive properties through reaction include active energy ray curable adhesives such as (meth)acrylate adhesives and cationic polymerization curable adhesives. (Meth)acrylate refers to acrylate and / or methacrylate. Examples of curable components in (meth)acrylate adhesives include compounds having a (meth)acryloyl group and compounds having a vinyl group. For cationic polymerization curable adhesives, compounds having an epoxy group or an oxetanyl group can also be used. Compounds having epoxy groups are not particularly limited as long as they have at least two epoxy groups in their molecule; various known curable epoxy compounds can be used. Preferred epoxy compounds include, for example, compounds having at least two epoxy groups and at least one aromatic ring in their molecule (aromatic epoxy compounds), and compounds having at least two epoxy groups in their molecule, with at least one of them formed between two adjacent carbon atoms constituting an alicyclic ring (alicyclic epoxy compounds). In particular, from the viewpoint of resistance to heat deformation, UV-curing adhesives that harden with UV irradiation are preferably used.

[0142] Each layer of the adhesive layer and the tack layer may have ultraviolet absorbing properties. These layers can be imparted with ultraviolet absorbing properties by known methods, such as treatment with ultraviolet absorbers such as salicylic acid ester compounds, benzophenol compounds, benzotriazole compounds, cyanoacrylate compounds, and nickel complex salt compounds.

[0143] The adhesive layer and bonding layer can be attached by any suitable method. Examples include preparing an adhesive solution with a concentration of about 10-40% by weight by dissolving or dispersing a base polymer or its composition in a solvent consisting of toluene and ethyl acetate, either individually or as a mixture, and directly attaching it to the film by a casting or coating method, or forming an adhesive layer on a separator and transferring it, similar to the above.

[0144] The adhesive layer and bonding layer may be provided on one or both sides of the film by superimposing layers of different compositions or types. Furthermore, when adhesive layers are provided on both sides, the composition, type, and thickness of the adhesive layers on the front and back of the film may be the same or different.

[0145] (Other optically anisotropic films) The viewing angle control system may use a light-absorbing anisotropic film or optical film in combination with other optical anisotropic films or photorotators. The inclusion of other optical anisotropic films in the viewing angle control system further improves the controllability of the viewing angle.

[0146] Other optically anisotropic films, like the light-absorbing anisotropic films described above, preferably contain a dichroic substance. The types of dichroic substances are as described above. Furthermore, other optically anisotropic films preferably contain liquid crystal compounds, similar to the light-absorbing anisotropic films described above. The types of liquid crystal compounds are as described above. Other preferred embodiments of optically anisotropic films include layers in which dichroic substances are oriented in the thickness direction or in the in-plane direction. The above preferred embodiments can be formed by adding a dichroic substance to a liquid crystal compound and oriented it in a desired direction. Other methods for forming optically anisotropic films are not particularly limited and include known methods. Among these, methods using compositions containing a dichroic substance and a liquid crystal compound are preferred.

[0147] As other optically anisotropic films, it is also preferable to use resin films that contain polymers such as carbonate, cycloolefin, cellulose acylate, methyl methacrylate, styrene, or maleic anhydride, and have optical anisotropy.

[0148] (Barrier layer) The viewing angle control system may have a barrier layer. The barrier layer, also called a gas barrier layer (oxygen barrier layer), has the function of protecting the light-absorbing anisotropic film or polarizer from gases such as oxygen in the atmosphere, moisture, light rays, or compounds contained in adjacent layers. For information regarding the barrier layer, see, for example, paragraphs

[0014] to

[0054] of Japanese Patent Publication No. 2014-159124, paragraphs

[0042] to

[0075] of Japanese Patent Publication No. 2017-121721, paragraphs

[0045] to

[0054] of Japanese Patent Publication No. 2017-115076, paragraphs

[0010] to

[0061] of Japanese Patent Publication No. 2012-213938, and paragraphs

[0021] to

[0031] of Japanese Patent Publication No. 2005-169994.

[0149] (Refractive index adjustment layer) The viewing angle control system may have a refractive index adjustment layer. When the viewing angle control system has a refractive index adjustment layer, the effects of internal reflection caused by the high refractive index of the light-absorbing anisotropic film can be suppressed. The refractive index adjustment layer is positioned in contact with the light-absorbing anisotropic film and has an in-plane average refractive index of 1.55 to 1.70 at a wavelength of 550 nm. Preferably, the refractive index adjustment layer is a layer for performing so-called index matching.

[0150] [Image display device] The above-mentioned light-absorbing anisotropic film, the above-mentioned optical film, and the above-mentioned viewing angle control system can all be used with any image display device. The image display device is not particularly limited and examples include liquid crystal display devices, self-emissive display devices (organic EL (electroluminescence) display devices, and micro-LED (light-emitting diode) display devices). Examples of image display devices include those comprising a display panel and the optical film or viewing angle control system disposed on one main surface of the display panel. Examples of display panels in an image display device include a display panel including a liquid crystal cell and a display panel for a self-emissive display device, and the optical film or viewing angle control system is disposed on these display panels.

[0151] A liquid crystal display device, for example, has liquid crystal cells and a backlight, with polarizers installed on both the viewing side and the backlight side of the liquid crystal cells. The viewing angle control system can be applied to either the viewing side or the backlight side of the liquid crystal display device, or to both sides. Application to a liquid crystal display device can be achieved by replacing the polarizers on either or both sides of the liquid crystal display device with the viewing angle control system. In other words, the polarizers included in the viewing angle control system can be used as polarizers provided on both sides of the liquid crystal cells.

[0152] When applying a viewing angle control system to an organic EL display device, it is preferable to position the viewing angle control system on the viewing side of the organic EL display device, and to position the polarizer in the viewing angle control system closer to the organic EL display device than the light-absorbing anisotropic film. It is also preferable to position a λ / 4 plate between the polarizer and the organic EL display device. Furthermore, in the viewing angle control system within the image display device, it is preferable that the light-absorbing anisotropic film is positioned on the viewing side relative to the polarizer. The following provides a detailed description of the liquid crystal cells that make up a liquid crystal display device.

[0153] (Liquid crystal cell) The liquid crystal cells used in liquid crystal display devices are preferably in VA (Vertical Alignment) mode, OCB (Optically Compensated Bend) mode, IPS (In-Plane-Switching) mode, or TN (Twisted Nematic) mode, but are not limited to these.

[0154] In TN mode liquid crystal cells, when no voltage is applied, the rod-shaped liquid crystal molecules are substantially horizontally oriented and further twisted to a 60-120° angle. TN mode liquid crystal cells are the most widely used in color TFT (Thin Film Transistor) liquid crystal display devices and are described in numerous publications.

[0155] In VA mode liquid crystal cells, rod-shaped liquid crystalline molecules are substantially oriented vertically when no voltage is applied. VA mode liquid crystal cells include (1) narrowly defined VA mode liquid crystal cells in which rod-shaped liquid crystalline molecules are substantially oriented vertically when no voltage is applied and substantially oriented horizontally when voltage is applied (described in Japanese Patent Publication No. 2-176625), (2) multi-domain liquid crystal cells (MVA mode) in which the VA mode is multi-domain to expand the viewing angle (described in SID97, Digest of tech.Papers (Proceedings) 28 (1997) 845), (3) liquid crystal cells in a mode (n-ASM mode) in which rod-shaped liquid crystalline molecules are substantially oriented vertically when no voltage is applied and twisted multi-domain orientation when voltage is applied (described in the Proceedings of the Japan Liquid Crystal Symposium 58-59 (1998)), and (4) SURVIVAL mode liquid crystal cells (presented at LCD International 98). Furthermore, any of the following types may be used: PVA (Patterned Vertical Alignment), Optical Alignment, and PSA (Polymer-Sustained Alignment). Details of these modes are described in Japanese Patent Publication No. 2006-215326 and Japanese Patent Publication No. 2008-538819.

[0156] In IPS mode liquid crystal cells, rod-shaped liquid crystal molecules are oriented substantially parallel to the substrate, and when an electric field parallel to the substrate surface is applied, the liquid crystal molecules respond in a planar manner. In IPS mode, black is displayed when no electric field is applied, and the absorption axes of the upper and lower pair of polarizers are orthogonal. Methods for reducing light leakage when displaying black at an oblique angle and improving the viewing angle using an optical compensation sheet are disclosed in Japanese Patent Publication No. 10-054982, Japanese Patent Publication No. 11-202323, Japanese Patent Publication No. 9-292522, Japanese Patent Publication No. 11-133408, Japanese Patent Publication No. 11-305217, and Japanese Patent Publication No. 10-307291. [Examples]

[0157] The features of the present invention will be further described below with reference to examples and comparative examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted restrictively by the specific examples shown below.

[0158] [Example 1] The light-absorbing anisotropic film according to the present invention was manufactured by a method comprising, in this order, a specific orientation film formation step of forming a specific orientation film, a coating film formation step of applying a light-absorbing anisotropic film formation composition onto the specific orientation film to form a coating film, and an orientation step of aligning the liquid crystalline components contained in the coating film.

[0159] <Fabrication of light-absorbing anisotropic films> (Specific alignment film formation process) A cellulose acylate film (TAC substrate with a thickness of 40 μm; "TG40" manufactured by Fujifilm Corporation) was cut to a size of 40 cm in width and 120 cm in length to obtain a transparent support (transparent substrate film). One surface of the cut support was saponified with an alkaline solution, and the following orientation film forming coating solution 1 was applied to the saponified surface with a wire bar to form a first coating film. The first coating film formed on the support was dried with hot air at 60°C for 60 seconds, and then with hot air at 100°C for 120 seconds to form a resin film. The thickness of the resin film was 0.5 μm.

[0160] -------------------------------------------------- (Coating solution for forming orientation film 1) -------------------------------------------------- • 3.80 parts by mass of the following modified polyvinyl alcohol • Initiator Irg2959 0.20 parts by mass ·Water 70 parts by mass • Methanol 30 parts by mass --------------------------------------------------

[0161] Modified polyvinyl alcohol (PVA-1) [ka]

[0162] The following photo-alignment film-forming composition F1 was applied to the obtained resin film and dried at 60°C for 2 minutes to form a second coating film with a thickness of 0.03 μm. The photo-alignment film forming coating solution F1 was prepared by mixing the components listed below, stirring the mixture for 1 hour, and then filtering it through a 0.45 μm filter.

[0163] -------------------------------------------------- Composition F1 for forming photo-alignment film -------------------------------------------------- • The following photo-aligning material F1: 0.3 parts by mass 2-Butoxyethanol 41.6 parts by mass • Dipropylene glycol monomethyl ether 41.6 parts by mass ·Pure water 16.5 parts by mass --------------------------------------------------

[0164] [ka]

[0165] As shown in Figure 5A, the coated film of the photo-alignment film-forming composition formed on the support was divided into two regions: a first region 51 on the negative X-axis side and a second region 52 on the positive X-axis side, at a boundary line L equidistant from both ends in the longitudinal direction (X-axis direction). Both the first region 51 and the second region 52 had a short side (width) length of 40 cm along the Y-axis direction and a long side length of 60 cm along the X-axis direction.

[0166] As a photo-alignment treatment, polarized ultraviolet light was irradiated from different directions onto the first region 51 and the second region 52 of the coated film 50. First, as shown in FIG. 5B, a mask M is disposed so as to cover the upper part of the second region 52 of the coating film 50 to shield the second region 52 from light, and polarized ultraviolet rays (irradiation dose: 2000 mJ / cm 2 ) are irradiated from the positive direction of the Z axis (direction of angle θ = 0°) onto the exposed first region 51 using an ultraviolet exposure apparatus. Next, as shown in FIG. 5C, the mask M is moved to a position covering the upper part of the first region 51 to shield the first region 51 from light, and polarized ultraviolet rays (irradiation dose: 2000 mJ / cm 2 ) are irradiated from the direction of angle θ = 35° and angle φ = 0° onto the exposed second region 52 using an ultraviolet exposure apparatus. Thereby, an alignment film F having different directions of alignment regulating force is formed in the first region 51 and the second region 52.

[0167] (Coating Film Forming Step) On the surface of the alignment film F formed in the above-described specific alignment film forming step, the following composition P1 for forming a light absorption anisotropic film is applied with a wire bar to form a coating film P1.

[0168] ――――――――――――――――――――――――――――――――― Composition of the Composition P1 for Forming a Light Absorption Anisotropic Film ――――――――――――――――――――――――――――――――― · Liquid crystal compound L1 3.977 parts by mass · Liquid crystal compound L2 2.593 parts by mass · Dichroic substance Y1 0.294 parts by mass · Dichroic substance M1 0.130 parts by mass · Dichroic substance C1 0.873 parts by mass · Polymerization initiator IRGACURE OXE-02 (manufactured by BASF) 0.130 parts by mass · Interface improver B1 0.003 parts by mass · Cyclopentanone 82.800 parts by mass · Tetrahydrofuran 9.200 parts by mass ―――――――――――――――――――――――――――――――――

[0169] Liquid crystalline compound L1 Liquid crystalline compound L2

Chem.

[0170] Dichroic substance Y1

Chem.

[0171] Dichroic substance M1

Chem.

[0172] Dichroic substance C1

Chem.

[0173] Interface improver B1

Chem.

[0174] (Alignment process) Next, after heating the coating film P1 formed in the coating film forming process at 120 °C for 30 seconds, the coating film P1 was cooled to 100 °C. Thereafter, the heated coating film P1 was irradiated with an LED lamp (central wavelength 365 nm) at room temperature (25 °C) under irradiation conditions of an illuminance of 200 mW / cm 2 for 2 seconds, thereby producing a light absorption anisotropic film P1 on the surface of the alignment film F, and obtaining an optical film P1 having a transparent support, an alignment film F, and a light absorption anisotropic film P1 in this order. [[ID=6I]]

[0175] <Measurement in the direction of the center axis of transmittance> Samples measuring 4 cm × 4 cm were cut from the regions corresponding to the first region 51 and the second region 52 of the obtained optical film P1. Next, following the method described above, each sample, set on the sample stage with the film surface horizontal, was irradiated with P-polarized light at a wavelength of 550 nm using a UV-Vis-Infrared spectrophotometer "JASCO V-670 / ARMN-735" (manufactured by JASCO Corporation), and the direction of the transmittance center axis of each sample was measured. From this, the angle θ between the direction of the transmittance center axis and the normal to the surface of the optical absorption anisotropy film P1, and the angle φ with respect to the reference direction of the orthogonal projection of the transmittance center axis onto the surface of the optical absorption anisotropy film P1 were determined. The reference direction of angle φ was defined as the negative direction (longitudinal direction) of the X-axis in the optical absorption anisotropy film P1.

[0176] The measurement results showed that the transmittance center axis of the optical film P1 sample obtained from the first region 51 was aligned with the normal to the light-absorbing anisotropic film P1. That is, the angle θ between the transmittance center axis and the normal to the light-absorbing anisotropic film P1 was 0°. On the other hand, the transmittance center axis of the optical film P1 sample obtained from the second region 52 was tilted at an angle of 34° with respect to the normal of the light-absorbing anisotropic film P1. In other words, the angle θ between the transmittance center axis and the normal of the optical film P1 in the second region 52 was 34°. Furthermore, in the optical film P1 sample obtained from the second region 52, the orthogonal projection of the transmittance center axis onto the surface of the light-absorbing anisotropic film extended in the direction of angle φ=0°. Therefore, it was confirmed that the light-absorbing anisotropic film P1 obtained in Example 1 has a first region 51 where the angle θ indicating the direction of the transmittance central axis is 0°, and a second region 52 where the angles θ and φ indicating the direction of the transmittance central axis are 34° and 0°, respectively, arranged side by side in the X-axis direction, as shown in Figure 1.

[0177] <Fabrication of an image display device> The following barrier layer-forming composition G was continuously applied to the surface of the optical film P1 obtained above, on the side with the light-absorbing anisotropic film P1, using a wire bar to form a coating. Next, hot air at 60°C was blown onto the formed coating film for 60 seconds, and then hot air at 100°C was blown for 120 seconds to dry the coating film and form the barrier layer G, obtaining an optical film with a barrier layer. The film thickness of the barrier layer G was 1.0 μm.

[0178] ――――――――――――――――――――――――――――――――― (Composition G for forming barrier layer) ――――――――――――――――――――――――――――――――― · 3.88 parts by mass of the above modified polyvinyl alcohol PVA-1 · 0.20 parts by mass of IRGACURE2959 · 70 parts by mass of water · 30 parts by mass of methanol ―――――――――――――――――――――――――――――――――

[0179] An image display device ("iPad (registered trademark) 2 WiFi model 16GB", manufactured by Apple) was disassembled, the image display panel (width 14.8 cm and length 19.7 cm) was disassembled, the liquid crystal cell was taken out, and the viewing-side polarizing plate was peeled off from the liquid crystal cell. Next, a glass plate of the same size as the above optical film with a barrier layer (width 40 cm and length 120 cm) was prepared, and two of the above image display panels were respectively attached to predetermined positions on the glass plate. Then, the above-prepared optical film with a barrier layer was bonded to the surface of the glass plate to which the image display panel was attached, on the side opposite to the image display panel, using the following adhesive sheet so that the barrier layer G faced the glass plate, thereby manufacturing an image display device.

[0180] (Preparation of adhesive sheet) An acrylate polymer was prepared according to the following procedure. 95 parts by mass of butyl acrylate and 5 parts by mass of acrylic acid were charged into a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer, and a stirring device, and mixed. The obtained mixture was polymerized by solution polymerization to obtain an acrylate polymer A1 with an average molecular weight of 2 million and a molecular weight distribution (Mw / Mn) of 3.0. To the obtained acrylate polymer A1 (100 parts by mass), Coronate L (75% by mass ethyl acetate solution of trimethylolpropane adduct of tolylene diisocyanate, number of isocyanate groups per molecule: 3, manufactured by Nippon Polyurethane Industry Co., Ltd.) (1.0 part by mass) and silane coupling agent KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.) (0.2 parts by mass) were mixed. Ethyl acetate was added to the resulting mixture so that the total solid content concentration of the mixture was 10% by mass to prepare an adhesive-forming composition. This composition was applied to a separator film surface-treated with a silicone-based release agent using a die coater, and the formed coating film was dried at 90°C for 1 minute to obtain an acrylate-based adhesive sheet. The thickness of the obtained adhesive sheet was 25 μm, and the storage modulus was 0.1 MPa.

[0181] Figure 9 shows the configuration of the image display device fabricated in Example 1. Figure 9 is a side view of the elongated image display device 100, observed from the width direction (negative direction of the Y-axis) within the plane of the image display device 100. As shown in Figure 9, the image display device 100 comprises an optical film with a barrier layer 110, an adhesive sheet 112, a glass plate 120, and a first panel 131 and a second panel 132. The light-absorbing anisotropic film (not shown) of the optical film with a barrier layer 110 has a first region on the negative direction side of the X-axis where the angle θ of the transmittance center axis is 0°, and a second region on the positive direction side of the X-axis where the angle θ of the transmittance center axis is 34° and the angle φ of the orthogonal projection of the transmittance center axis is 0°. Furthermore, the first panel 131 is positioned so that its X-axis center is 20 cm away from the negative X-axis end of the barrier layer optical film 110 (hereinafter also referred to as "position I"), and the second panel 132 is positioned so that its X-axis center is 100 cm away from the aforementioned end (hereinafter also referred to as "position III").

[0182] 〔evaluation〕 <Visibility> The image display device 100 fabricated in Example 1 was observed from an observation position 140 cm away in the stacking direction (positive Z-axis direction) from position I where the first panel 131 was installed. The visibility (sharpness) of the displayed image was evaluated for each of the first panel 131 installed at position I and the second panel 132 installed at position III, based on the evaluation criteria described below.

[0183] (Visibility evaluation criteria) "A": The displayed image is clearly visible. "B": The displayed image is visible. "C": The displayed image is not visible.

[0184] <Reflection> An image display device 100, with an optical film 110 with a barrier layer positioned vertically above it, was installed at an angle such that the elevation angle from the horizontal plane when observing from the negative Y-axis side to the positive Y-axis side was 30°. Next, a glass plate R (40 cm wide and 120 cm long) for reflection evaluation was installed above the image display device 100, with the longitudinal direction of the glass plate R aligned with the horizontal direction. At this time, the glass plate R was positioned such that the plane containing the normal of the display surface of the image display device 100 (the surface of the optical film 110 with a barrier layer) and the normal of the glass plate R included the vertical direction, and the angle between the normal of the image display device 100 and the normal of the glass plate R was 85°. Furthermore, the glass plate R was installed at a position where the distance between the center of the surface of the glass plate R facing the image display device 100 and the center of the display surface of the image display device 100 was 50 cm. Using the image display device 100 and glass plate R installed as described above, the reflection (reflected image) of the displayed image on the surface of the glass plate R was observed and evaluated. For the reflection evaluation, observation was made from an observation position corresponding to position III where the second panel 132 of the image display device 100 is located. More specifically, the observation position was set at a position where the distance from the center line equidistant from the long side of the surface of the glass plate R to the YZ plane (the intersection point α) of position III, the normal to the display surface of the image display device 100, and the normal to the glass plate R is 140 cm, and the angle between the straight line connecting the observation position and the intersection point α and the normal to the glass plate R is 20°. From this observation position, the displayed image of the first panel 131 installed at position I of the image display device 100 and the displayed image of the second panel 132 installed at position III, reflected by the glass plate R, were observed, and the reflection of the displayed image was evaluated based on the following evaluation criteria from the observation results.

[0185] (Reflection evaluation criteria) "A": The reflected image is weakly visible. "B": Reflected image is visible. "C": The reflected image is strongly visible.

[0186] [Example 2] In the specific orientation film formation step of Example 1, the coated film of the photo-alignment film formation composition formed on the support was divided into three regions with equal longitudinal lengths, and polarized ultraviolet light was irradiated to each region from different directions as a photo-alignment treatment. Except for these differences, an optical film with a barrier layer was prepared according to the method of Example 1.

[0187] More specifically, in the specific orientation film formation process, the coated film of the photo-alignment film formation composition formed on the support was divided into three regions such that their longitudinal lengths were equal. All three of these regions had a length of 40 cm in the Y-axis direction and a length of 40 cm in the X-axis direction. Next, as a photo-alignment treatment, as shown in Figure 6, polarized ultraviolet light (irradiation dose 2000 mJ / cm²) is applied to the first region 61, second region 62, and third region 63 of the coated film 60 from different directions using an ultraviolet exposure apparatus. 2 ) was irradiated. First, as shown in Figure 6A, the second region 62 and the third region 63 were shielded using a mask M, and polarized ultraviolet light was irradiated onto the exposed first region 61 from the positive Z-axis direction (angle θ=0°). Next, as shown in Figure 6B, the first region 61 and the third region 63 were shielded using a mask M, and polarized ultraviolet light was irradiated onto the exposed second region 62 from the direction of angles θ=15° and φ=0°. Next, as shown in Figure 6C, the first region 61 and the second region 62 were shielded using a mask M, and polarized ultraviolet light was irradiated onto the exposed third region 63 from the direction of angles θ=35° and φ=0°. As a result, an orientation film F was formed in the first region 61, the second region 62, and the third region 63, where the direction of the orientation restricting force was different.

[0188] A light-absorbing anisotropic film P2 was fabricated on the surface of the alignment film F according to the method described in Example 1, except that the alignment film F formed in the above-described specific alignment film formation step was used, and an optical film P2 having a transparent support, alignment film F, and light-absorbing anisotropic film P2 in this order was obtained. Following the method described in Example 1, "Measurement of the Direction of the Transmittance Center Axis," the angle θ between the direction of the transmittance center axis and the normal to the surface of the light-absorbing anisotropic film P2, and the angle φ with respect to the reference direction of the orthogonal projection of the transmittance center axis onto the surface of the light-absorbing anisotropic film P2 were determined for samples cut from the regions corresponding to the first, second, and third regions of the obtained optical film P2. The measurement results are shown in Table 1, which will be described later.

[0189] An image display device was fabricated according to the method described in <Fabrication of Image Display Device> of Example 1, except that the optical film P2 obtained above was used. However, in Example 2, three image display panels were mounted in predetermined positions on the glass plate.

[0190] Figure 10 shows the configuration of the image display device fabricated in Example 2. Figure 10 is a side view of the elongated image display device 200, observed from the width direction (negative direction of the Y-axis) within the plane of the image display device 200. As shown in Figure 10, the image display device 200 comprises an optical film with a barrier layer 210, an adhesive sheet 112, a glass plate 120, and a first panel 131, a second panel 132, and a third panel 133. The light-absorbing anisotropic film (not shown) of the optical film with a barrier layer 210 has the following regions arranged in this order from the negative direction of the X-axis: a first region where the angle θ of the transmittance center axis is 0°, a second region where the angle θ of the transmittance center axis is 15° and the angle φ of the orthogonal projection of the transmittance center axis is 0°, and a third region where the angle θ of the transmittance center axis is 35° and the angle φ of the orthogonal projection of the transmittance center axis is 0°. Furthermore, the first panel 131 is provided at position I in the image display device of Example 1, the second panel 132 is provided at a position (hereinafter also referred to as "position II") where the center of the second panel 132 in the X-axis direction is 60 cm away from the negative X-axis end of the optical film 210 with a barrier layer, and the third panel 133 is provided at position III in the image display device of Example 1.

[0191] 〔evaluation〕 <Visibility> The image display device 200 fabricated in Example 2 was observed from an observation position 140 cm away in the stacking direction (positive Z-axis direction) from position I where the first panel 131 was installed. Based on the observations obtained, the visibility (sharpness) of the displayed image was evaluated for each of the following: the first panel 131 located at position I, the second panel 132 located at position II, and the second panel 133 located at position III, using the same evaluation criteria as in Example 1.

[0192] <Reflection> In Example 2, the reflection of the display image of the image display device 200 onto the glass plate R was observed according to the reflection evaluation method in Example 1, and the reflection of the display image onto the glass plate R was evaluated. Specifically, the image display device 200 and the glass plate R were set up in accordance with the method described in Example 1, and the reflection on the glass plate R was observed from the same observation position as in Example 1 (a position on the YZ plane including position III). In Example 2, the reflection of the reflective image was evaluated for each of the display images: the display image of the first panel 131 located at position I, the display image of the second panel 132 located at position II, and the display image of the third panel 133 located at position III.

[0193] [Example 3] An optical film with a barrier layer was prepared according to the method of Example 2, except that the irradiation direction of polarized ultraviolet light irradiated to the first region 61, second region 62, and third region 63 of the coated film 60 was changed as described below in the specific orientation film formation step of Example 2. More specifically, polarized ultraviolet light was irradiated onto the first region 61 from the direction of angle θ=30° and angle φ=180°, polarized ultraviolet light was irradiated onto the second region 62 from the positive direction of the Z axis (direction of angle θ=0°), and polarized ultraviolet light was irradiated onto the third region 63 from the direction of angle θ=30° and angle φ=0°. This resulted in the formation of alignment films F with different orientation restricting forces in the first region 61, the second region 62, and the third region 63, thereby producing the barrier layer optical film of Example 3. An image display device was fabricated using the prepared barrier layer-equipped optical film according to the method described in Example 2.

[0194] 〔evaluation〕 <Visibility> The image display device fabricated in Example 3 was observed from an observation position 100 cm away in the stacking direction (positive Z-axis direction) from position II where the second panel was installed. Based on the observations obtained, the visibility (sharpness) of the displayed image was evaluated for each of the following: the first panel located at position I, the second panel located at position II, and the second panel located at position III, using the same evaluation criteria as in Example 1.

[0195] <Reflection> According to the reflection evaluation method in Example 2, the reflected image of the display image of the image display device projected onto the glass plate R was observed, and the reflection of the display image onto the glass plate R was evaluated.

[0196] [Example 4] An optical film with a barrier layer was prepared according to the method described in Example 1, except that the photo-alignment treatment in the specific orientation film formation step was modified as described below. Specifically, a mold with a width of 40 cm, a length of 120 cm, and a curvature of 0.0131 [1 / cm] was fabricated, and a substrate on which a coating film of the orientation film-forming composition had been formed was placed along the surface of the fabricated mold. Next, as shown in Figure 7, polarized ultraviolet light (irradiation dose 2000 mJ / cm²) was applied to the surface of the coating film from the direction normal to the contact surface of the coating film (positive Z-axis direction shown in Figure 7) at a position where the length from both ends in the longitudinal direction of the coating film is 60 cm. 2 The film was irradiated with ). After irradiation, the resulting alignment film was peeled off the mold to form an alignment film F in which the direction of the alignment restricting force (angle θ) continuously changes along the longitudinal direction, and the optical film with a barrier layer of Example 4 was fabricated using the resulting alignment film F. An image display device was fabricated using the prepared barrier layer-equipped optical film according to the method described in Example 2.

[0197] 〔evaluation〕 The fabricated image display device was evaluated for visibility and reflections, respectively, according to the evaluation method described in Example 3.

[0198] [Comparative Example 1] A barrier layer-equipped optical film of Comparative Example 1 was prepared according to the method of Example 1, except that, instead of the specific orientation film formation step of Example 1, a step was performed to irradiate the entire surface of the coated film of the photo-alignment film-forming composition formed on the support with polarized ultraviolet light from the positive Z-axis direction (angle θ=0° direction) to produce an orientation film in which the direction of the orientation restricting force is parallel across the entire surface. An image display device was fabricated using the prepared barrier layer-equipped optical film according to the method described in Example 2. The fabricated image display device was evaluated for visibility and reflections, respectively, according to the evaluation method described in Example 2.

[0199] Table 1 shows the characteristics of the light-absorbing anisotropic films prepared in each example and comparative example, as well as the evaluation results for each. In Table 1, the "Light Absorption Anisotropic Film" column indicates the direction of the transmittance center axis in the in-plane direction of the light absorption anisotropic film prepared in each example and comparative example. The "Angle θ" column indicates the angle between the transmittance center axis and the normal to the surface of the light absorption anisotropic film, and the "Angle φ" column indicates the angle between the orthogonal projection of the transmittance center axis onto the surface of the light absorption anisotropic film and the longitudinal direction of the light absorption anisotropic film. In Table 1, "Continuous Change" in Example 4 means that the angle θ, which indicates the direction of the transmittance central axis, changes continuously along the longitudinal direction of the light-absorbing anisotropic film. Furthermore, the "Angle θ" column in Example 4 indicates that the angle θ between the transmittance central axis and the normal to the surface of the light-absorbing anisotropic film continuously decreases from both ends in the X-axis direction toward the center, with angle θ being 30° at positions I and III, and angle θ being 0° at position II. Furthermore, the "Angle φ" column in Example 4 indicates that, in the light-absorbing anisotropic film, angle φ was either 0° or 180°, except at position II where angle θ was 0°. In Table 1, "I," "II," and "III" in the "Visibility" and "Reflections" columns indicate the location of the image display panel where the respective evaluation was performed.

[0200] [Table 1]

[0201] As shown in Table 1, the light-absorbing anisotropic films of Examples 1 to 4 according to the present invention exhibited excellent visibility of the displayed image at all positions I to III, confirming the superior effects of the present invention.

[0202] [Example 5] A cellulose acylate film (TAC substrate with a thickness of 40 μm; "TG40" manufactured by Fujifilm Corporation) was cut to a size of 30 cm in width and 60 cm in length to obtain a transparent support (transparent substrate film). One surface of the cut support was saponified with an alkaline solution, and the above-mentioned orientation film forming coating solution 1 was applied to the saponified surface with a wire bar to form a first coating film. The first coating film formed on the support was dried with hot air at 60°C for 60 seconds, and then with hot air at 100°C for 120 seconds to form a resin film. The thickness of the resin film was 0.5 μm.

[0203] The above-mentioned photo-alignment film-forming composition F1 was applied to the obtained resin film and dried at 60°C for 2 minutes to form a second coating film with a thickness of 0.03 μm. The coating film of the photo-alignment film-forming composition formed on the support was divided into two regions at boundary lines equidistant from both ends in the longitudinal direction (Y-axis direction): a first region on the positive Y-axis side and a second region on the negative Y-axis side. Both the first and second regions had a length of 30 cm in the Y-axis direction and a length of 30 cm in the X-axis direction.

[0204] Next, as a photo-alignment treatment, polarized ultraviolet light (irradiation dose 2000 mJ / cm²) is applied to the first and second regions of the coated film from different directions using an ultraviolet exposure apparatus. 2 ) was irradiated. First, as shown in Figure 8A, the second region 82 of the coated film 80 was shielded from light using a mask M, and the exposed first region 81 was irradiated with polarized ultraviolet light from a direction with an angle θ = 30° and an angle φ = 0°. Next, as shown in Figure 8B, the first region 81 of the coated film 80 was shielded from light using a mask M, and the exposed second region 82 was irradiated with polarized ultraviolet light from a direction with an angle θ = 30° and an angle φ = 50°. As a result, an orientation film F was formed in the first region 81 and the second region 82, where the direction of the orientation restricting force was different.

[0205] A light-absorbing anisotropic film P5 was fabricated on the surface of the alignment film F according to the method described in Example 1, except that the alignment film F formed in the specific alignment film formation step described above was used, and an optical film P5 having a transparent support, alignment film F, and light-absorbing anisotropic film P5 in this order was obtained. Following the method described in Example 1, "Measurement of the Direction of the Transmittance Center Axis," the angle θ between the direction of the transmittance center axis and the normal to the surface of the light-absorbing anisotropic film P1, and the angle φ with respect to the reference direction of the orthogonal projection of the transmittance center axis onto the surface of the light-absorbing anisotropic film P1 were determined for samples cut from the regions corresponding to the first and second regions of the obtained optical film P5. The reference direction for angle φ was defined as the negative direction (width direction) of the X-axis in the light-absorbing anisotropic film P5.

[0206] The measurement results showed that the transmittance center axis of the optical film P5 sample obtained from the first region was tilted at an angle of 31° with respect to the normal of the light-absorbing anisotropic film P5. That is, the angle θ between the transmittance center axis and the normal of optical film P5 in the first region was 31°. Furthermore, in the optical film P5 sample obtained from the first region, the orthogonal projection of the transmittance center axis onto the surface of the light-absorbing anisotropic film extended in the direction of angle φ=0°. Furthermore, the angle θ between the transmittance center axis and the normal of the optical film P5 sample obtained from the second region was 31°, and in the optical film P5 sample obtained from the second region, the orthogonal projection of the transmittance center axis onto the surface of the light-absorbing anisotropic film extended in the direction of angle φ = 49°. Therefore, it was confirmed that the light-absorbing anisotropic film P5 obtained in Example 5 has a first region 81 where the angles θ and φ indicating the direction of the transmittance central axis are 31° and 0°, respectively, and a second region 82 where the angles θ and φ indicating the direction of the transmittance central axis are 31° and 49°, respectively, arranged side by side in the Y-axis direction, as shown in Figure 4.

[0207] <Fabrication of an image display device> The above-mentioned barrier layer-forming composition G was continuously applied to the surface of the optical film P5 obtained above, on the side with the light-absorbing anisotropic film P5, using a wire bar to form a coating film. Next, the formed coating was dried by blowing 60°C hot air for 60 seconds, and then 100°C hot air for 120 seconds, thereby forming a barrier layer G and obtaining an optical film with a barrier layer. The thickness of the barrier layer G was 1.0 μm.

[0208] An image display device ("iPad® 2 WiFi model 16GB", manufactured by Apple Inc.) was disassembled, the image display panel (14.8 cm wide and 19.7 cm long) was disassembled, the liquid crystal cell was removed, and the polarizing plate on the viewing side was peeled off from the liquid crystal cell. Next, a glass plate of the same size as the optical film with barrier layer (30 cm wide and 60 cm long) was prepared, and two of the above image display panels were attached to the predetermined positions on the glass plate. Then, the optical film with barrier layer prepared above was bonded to the surface of the glass plate opposite to the image display panels using the above adhesive sheet, so that the barrier layer G faced the glass plate, thereby creating an image display device.

[0209] The fabricated image display device comprises an optical film with a barrier layer, an adhesive sheet, and a glass plate, and further comprises a first panel and a second panel as image display panels. The optical film with a barrier layer has a light-absorbing anisotropic film (not shown) in which a first region is located along the longitudinal direction, where the angle θ of the transmittance center axis is 31° and the angle φ of the orthogonal projection of the transmittance center axis is 0°, and a second region is located along the longitudinal direction, where the angle θ of the transmittance center axis is 31° and the angle φ of the orthogonal projection of the transmittance center axis is 49°. In the fabricated image display device, the first panel is positioned so that its center in the short direction is 10 cm away from the end of the first region in the longitudinal direction of the optical film with a barrier layer (hereinafter also referred to as "position IV"), and the second panel is positioned so that its center in the short direction is 50 cm away from the end of the first region in the longitudinal direction of the optical film with a barrier layer (hereinafter also referred to as "position VI").

[0210] 〔evaluation〕 <Visibility> Figures 11A and 11B are diagrams illustrating the evaluation method for the image display device fabricated in Example 5, and are schematic diagrams showing the observer's position O when evaluating the image display device 300. The image display device 300 is installed such that its longitudinal direction is aligned with the vertical direction (Y-axis direction), and the first region is positioned on the lower side and the second region on the upper side. Figure 11A is a front view of the image display device 300 as it is installed as described above, viewed from the direction normal to the surface, and Figure 11B is a top view of the image display device 300 as viewed from vertically above. Figure 11A shows positions IV, V (see Example 6), and VI in the image display device 300.

[0211] The height Y1 from the lower end of the image display device 300 shown in Figure 11A to the observer's position O is 50 cm, which is the same height as position VI. Furthermore, as shown in Figures 11A and 11B, the distance X1 in the X-axis direction from the center of the image display device 300 in the short direction (X-axis direction) to the observer's position O is 45 cm. Note that, from the observer's perspective, the image display device 300 is located on the positive X-axis side (right side of the paper). Furthermore, as shown in Figure 11B, the distance Z1 from the observer's position O to the plane containing the surface of the image display device 300 (XY plane) is 70 cm. From the observer's position O, the visibility (sharpness) of the displayed image was evaluated for each of the first panel located at position IV and the second panel located at position VI, based on the same evaluation criteria as in Example 1.

[0212] [Example 6] In the specific orientation film formation step of Example 6, the coated film of the photo-alignment film formation composition formed on the support was divided into three regions with equal longitudinal lengths, and the orientation film was prepared in accordance with the method of Example 5, except that polarized ultraviolet light was irradiated to each region from different directions as a photo-alignment treatment.

[0213] More specifically, in the specific orientation film formation process, the coated film of the photo-alignment film formation composition formed on the support was divided into three regions: a first region, a second region, and a third region, all of which had equal longitudinal lengths. In all three of these regions, the longitudinal length of the coated film was 20 cm, and the transverse length of the coated film was 30 cm. Next, as a photo-alignment treatment, polarized ultraviolet light (irradiation dose 2000 mJ / cm²) is applied to the first, second, and third regions of the coated film from different directions using an ultraviolet exposure apparatus. 2 ) was irradiated. First, the second and third regions were shielded using mask M, and polarized ultraviolet light was irradiated onto the exposed first region from a direction with angles θ=30° and φ=0°. Next, the first and third regions were shielded using mask M, and polarized ultraviolet light was irradiated onto the exposed second region from a direction with angles θ=30° and φ=30°. Next, the first and second regions were shielded using mask M, and polarized ultraviolet light was irradiated onto the exposed third region from a direction with angles θ=30° and φ=50°. When observing the coated film of the photo-alignment film-forming composition formed on the support from the front, the direction obtained by rotating the in-plane of the coated film 90° counterclockwise from the direction in which the first, second, and third regions are arranged in that order is used as the reference angle φ (φ=0°) for indicating the direction of polarized ultraviolet light irradiation. As a result, an orientation film F was formed in which the direction of the orientation restricting force differed in each of the first, second, and third regions.

[0214] A light-absorbing anisotropic film P6 was fabricated on the surface of the alignment film F according to the method described in Example 5, except that the alignment film F formed in the above-described specific alignment film formation step was used, and an optical film P6 having a transparent support, alignment film F, and light-absorbing anisotropic film P6 in this order was obtained. For samples cut from the regions corresponding to the first, second, and third regions of the obtained optical film P6 according to the method described in Example 5, the angle θ between the direction of the transmittance central axis and the normal to the surface of the light-absorbing anisotropic film P6, and the angle φ with respect to the reference direction of the orthogonal projection of the transmittance central axis onto the surface of the light-absorbing anisotropic film P6 were determined. The measurement results are shown in Table 2, which will be described later.

[0215] An image display device was fabricated according to the method described in <Fabrication of Image Display Device> of Example 5, except that the optical film P6 obtained above was used. However, in Example 6, three image display panels were mounted in predetermined positions on the glass plate. In the image display device fabricated in Example 6, the first panel is located at position IV in the image display device, the second panel is located at a position (hereinafter also referred to as "position IV") where the center of the first panel in the short direction is 30 cm away from the end of the first region in the longitudinal direction of the optical film with a barrier layer, and the third panel is located at position VI in the image display device.

[0216] 〔evaluation〕 <Visibility> For the obtained image display device, the visibility (sharpness) of the displayed image was evaluated for each of the following, from the observer's position O to position IV: the first panel, position V, and position VI, based on the same evaluation criteria as in Example 1, in accordance with the method described in Example 5.

[0217] [Comparative Example 2] A barrier layer-equipped optical film of Comparative Example 2 was prepared according to the method of Example 5, except that, instead of the specific orientation film formation step of Example 5, a step was performed in which polarized ultraviolet light was irradiated onto the entire surface of the coated film of the photo-alignment film-forming composition formed on the support from a direction with an angle θ=30° and an angle φ=0° to produce an orientation film in which the direction of the orientation restricting force is parallel on the entire surface. An image display device was fabricated using the fabricated barrier layer-equipped optical film according to the method described in Example 5, and the visibility of the fabricated image display device was evaluated according to the evaluation method described in Example 5.

[0218] Table 2 lists the characteristics of the light-absorbing anisotropic films prepared in each example and Comparative Example 2, as well as the evaluation results. In Table 2, the "Light Absorption Anisotropic Film" column indicates the direction of the transmittance center axis in the in-plane direction of the light absorption anisotropic film prepared in each example and comparative example. The "Angle θ" column indicates the angle between the transmittance center axis and the normal to the surface of the light absorption anisotropic film, and the "Angle φ" column indicates the angle between the orthogonal projection of the transmittance center axis onto the surface of the light absorption anisotropic film and the short-side direction of the light absorption anisotropic film. In Table 1, "IV," "V," and "VI" in the "Visibility" column indicate the location of the image display panel where the respective evaluation was performed.

[0219] [Table 2]

[0220] As shown in Table 2, the light-absorbing anisotropic film according to the present invention exhibits excellent visibility of the displayed image at all positions IV to VI, confirming the superior effects of the present invention. [Explanation of Symbols]

[0221] 1 Dichroic substance 10, 20, 30, 40 Light-absorbing anisotropic film 11,21,41,51,61,81 1st area 12,22,42,52,62,82 2nd area 23,63 Third area 30a central part 30b end 50, 60, 70, 80 oriented film 100,200,300 Image Display Device 110,210 Optical film with barrier layer 112 Adhesive Sheet 120 glass plates 131 Panel 1 (Image Display Panel) 132. Second Panel (Image Display Panel) L border M Mask

Claims

1. A light-absorbing anisotropic film containing a dichroic substance and a liquid crystal compound, The light-absorbing anisotropic film has multiple regions in the in-plane direction of the light-absorbing anisotropic film where the direction of the transmittance central axis is different. In the aforementioned multiple regions, the angle θ between the transmittance central axis and the normal direction of the surface of the light-absorbing anisotropic film is all within the range of 0 to 70°. A light-absorbing anisotropic film that satisfies any of requirements 1 to 3. Requirement 1: The angle θ in at least one of the plurality of regions is 0°. Requirement 2: In at least two of the multiple regions, the directions of the orthogonal projection of the transmittance central axis onto the surface of the light-absorbing anisotropic film are the same, and the angle θ is different in at least two of the regions. Requirement 3: In at least two of the multiple regions, the angle θ is the same, and in at least two of the regions, the directions of the orthogonal projection of the transmittance central axis onto the surface of the light-absorbing anisotropic film are different from each other.

2. The light-absorbing anisotropic film according to claim 1, satisfying requirement 1 or requirement 2.

3. The light-absorbing anisotropic film according to claim 2, wherein the angle θ increases stepwise or continuously, or decreases stepwise or continuously, as the film moves along the in-plane direction in which the plurality of regions are arranged.

4. The light-absorbing anisotropic film according to claim 2, wherein as the plurality of regions are arranged in the in-plane direction, the angle θ in the light-absorbing anisotropic film continuously increases or continuously decreases.

5. The light-absorbing anisotropic film according to claim 3, wherein, as the plurality of regions are arranged in the in-plane direction, the angle θ in the light-absorbing anisotropic film continuously increases or continuously decreases.

6. The light-absorbing anisotropic film according to claim 1, satisfying requirement 3 above.

7. The light-absorbing anisotropic film according to claim 6, wherein, along the in-plane direction in which the at least two regions are arranged, the angle φ between the direction of the orthogonal projection of the transmittance center axis and the in-plane direction increases stepwise or continuously, or decreases stepwise or continuously, as one moves from a first region included in the at least two regions toward other regions other than the first region.

8. The light-absorbing anisotropic film according to claim 6, wherein, along the in-plane direction in which the at least two regions are arranged, the angle φ between the direction of the orthogonal projection of the transmittance central axis and the in-plane direction continuously increases or continuously decreases as one moves from a first region included in the at least two regions toward other regions other than the first region.

9. The light-absorbing anisotropic film according to claim 7, wherein, along the in-plane direction in which the at least two regions are arranged, the angle φ between the direction of the orthogonal projection of the transmittance center axis and the in-plane direction continuously increases or continuously decreases as the direction progresses from a first region included in the at least two regions toward other regions other than the first region.

10. An optical film having a light-absorbing anisotropic layer and an alignment film according to any one of claims 1 to 9.

11. The optical film according to claim 10, further comprising a resin film containing polyvinyl alcohol or polyimide.

12. An image display device comprising a display panel and an optical film according to claim 10 disposed on one main surface of the display panel.

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