Light-absorbing anisotropic film, optical film, image display device

Abstract

To provide a light-absorbing anisotropic film in which a region having high visual recognition and a region having low visual recognition are easily controlled and viewing angle control is more excellent when applied to an image display device. Also, to provide an optical film and an image display device. The light-absorbing anisotropic film of the present application is a light-absorbing anisotropic film containing a dichroic substance and a liquid crystal compound, the light-absorbing anisotropic film having a plurality of regions in which the direction of a transmittance center axis differs in the in-plane direction of the light-absorbing anisotropic film, in the plurality of regions, the angle θ formed by the transmittance center axis and the normal direction of the surface of the light-absorbing anisotropic film is in the range of 0 to 70°, and any one of specific necessary conditions 1 to 3 is satisfied.

Description

Technical Field

[0001] This invention relates to an anisotropic light absorption film, an optical film, and an image display device. Background Technology

[0002] Image display devices are used in various situations, and depending on their purpose, viewing angle control is sometimes required to prevent peeping and glare from reflected images.

[0003] For example, Patent Document 1 discloses a viewing angle control system containing a dichroic material and having a polarizer (light absorption anisotropic film) with an angle of 0 to 45° between the absorption axis and the normal to the film surface.

[0004] Previous technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-145776 Summary of the Invention

[0007] The technical problem to be solved by the invention

[0008] In recent years, more stringent viewing angle control has been required in image display devices. For example, when using image display devices as in-vehicle displays such as car navigation systems, there are requirements to improve visual clarity in areas displaying information useful to the driver, while reducing visual clarity in areas displaying information not useful to the driver. Furthermore, there are requirements to improve visual clarity for the driver and passengers (other than the driver) to obtain information, while reducing visual clarity for those who do not need visual clarity and wish to obstruct their view. Thus, a higher degree of control over the viewing angle of the image display device is required.

[0009] The inventors' research on the viewing angle control system described in Patent Document 1 has clarified that there is still room for further improvement in the viewing angle controllability of visual recognition when observing a displayed image based on the viewing angle control.

[0010] In view of the above, the objective of the present invention is to provide a light absorption anisotropic film that, when applied to an image display device, allows for easy control of areas with high visual recognition and areas with low visual recognition, and provides superior viewing angle control.

[0011] Furthermore, the present invention also provides an optical film and an image display device.

[0012] means for solving technical problems

[0013] The inventors have discovered that the above-mentioned problems can be solved by the following structure.

[0014] [1] A light-absorbing anisotropic film, comprising a dichroic substance and a liquid crystal compound, wherein the light-absorbing anisotropic film has multiple regions in the in-plane direction of the light-absorbing anisotropic film with different directions of the central axis of transmittance, and in the multiple regions, the angle θ formed by the central axis of transmittance and the normal direction of the surface of the light-absorbing anisotropic film is in the range of 0 to 70°, satisfying any one of the necessary conditions 1 to 3 described below.

[0015] [2] The light-absorbing anisotropic film according to [1] satisfies the above-mentioned necessary condition 1 or the above-mentioned necessary condition 2.

[0016] [3] According to the light absorption anisotropic film described in [2], wherein,

[0017] As the plane moves along the in-plane direction where the aforementioned multiple regions are configured, the aforementioned angle θ increases either in stages or continuously, or decreases either in stages or continuously.

[0018] [4] The light-absorbing anisotropic film according to [2] or [3], wherein,

[0019] As the film moves along the in-plane direction where the aforementioned multiple regions are configured, the aforementioned angle θ in the light-absorbing anisotropic film continuously increases or continuously decreases.

[0020] [5] The light-absorbing anisotropic film according to [1] satisfies the above-mentioned necessary condition 3.

[0021] [6] According to the light absorption anisotropic film described in [5], wherein,

[0022] As the plane moves from the first region included in the at least two regions toward other regions along the in-plane direction where the at least two regions are configured, the angle φ between the orthogonal projection direction of the transmittance center axis and the in-plane direction increases or decreases in stages or continuously.

[0023] [7] The light-absorbing anisotropic film according to [5] or [6], wherein,

[0024] As the plane moves from the first region included in the at least two regions toward other regions along the in-plane direction where the at least two regions are configured, the angle φ between the orthogonal projection direction of the transmittance center axis and the in-plane direction continuously increases or continuously decreases.

[0025] [8] An optical film having a light-absorbing anisotropic layer and an orientation film as described in any one of [1] to [7].

[0026] [9] The optical film according to [8] further comprises a resin film containing polyvinyl alcohol or polyimide.

[0027]

[10] An image display device comprising a display panel and an optical film as described in [8] or [9] disposed on a main surface of the display panel.

[0028] Invention Effects

[0029] According to the present invention, a light absorption anisotropic film can be provided that, when applied to an image display device, allows for easy control of areas with high visual recognition and areas with low visual recognition, and provides superior viewing angle control.

[0030] Furthermore, according to the present invention, an optical film and an image display device can be provided. Attached Figure Description

[0031] Figure 1A This is a conceptual diagram illustrating one embodiment of an anisotropic light-absorbing film.

[0032] Figure 1B This is a conceptual diagram illustrating one embodiment of an anisotropic light-absorbing film.

[0033] Figure 2A This is a conceptual diagram illustrating another example of an implementation of an anisotropic light-absorbing film.

[0034] Figure 2B This is a conceptual diagram illustrating another example of an implementation of an anisotropic light-absorbing film.

[0035] Figure 3 This is a conceptual diagram illustrating another example of an implementation of an anisotropic light-absorbing film.

[0036] Figure 4A This is a conceptual diagram illustrating another example of an implementation of an anisotropic light-absorbing film.

[0037] Figure 4B This is a conceptual diagram illustrating another example of an implementation of an anisotropic light-absorbing film.

[0038] Figure 4C This is a conceptual diagram illustrating another example of an implementation of an anisotropic light-absorbing film.

[0039] Figure 5A This is a conceptual diagram illustrating an example of a photoorientation process performed in a method for manufacturing anisotropic light-absorbing films.

[0040] Figure 5BThis is a conceptual diagram illustrating an example of a photoorientation process performed in a method for manufacturing anisotropic light-absorbing films.

[0041] Figure 5C This is a conceptual diagram illustrating an example of a photoorientation process performed in a method for manufacturing anisotropic light-absorbing films.

[0042] Figure 6A This is a conceptual diagram illustrating another example of the photoorientation process performed in a method for manufacturing anisotropic light-absorbing films.

[0043] Figure 6B This is a conceptual diagram illustrating another example of the photoorientation process performed in a method for manufacturing anisotropic light-absorbing films.

[0044] Figure 6C This is a conceptual diagram illustrating another example of the photoorientation process performed in a method for manufacturing anisotropic light-absorbing films.

[0045] Figure 7 This is a conceptual diagram illustrating another example of the photoorientation process performed in a method for manufacturing anisotropic light-absorbing films.

[0046] Figure 8A This is a conceptual diagram illustrating another example of the photoorientation process performed in a method for manufacturing anisotropic light-absorbing films.

[0047] Figure 8B This is a conceptual diagram illustrating another example of the photoorientation process performed in a method for manufacturing anisotropic light-absorbing films.

[0048] Figure 9 This is a conceptual diagram illustrating one embodiment of an image display device.

[0049] Figure 10 This is a conceptual diagram illustrating another example of an implementation of an image display device.

[0050] Figure 11A This is an accompanying drawing illustrating an evaluation method for an image display device.

[0051] Figure 11B This is an accompanying drawing illustrating an evaluation method for an image display device. Detailed Implementation

[0052] The present invention will now be described in detail.

[0053] The following description of the constituent elements is based on a representative embodiment of the present invention, but the present invention is not limited to this embodiment.

[0054] In addition, in this specification, the numerical range indicated by “~” refers to the range including the values ​​recorded before and after “~” as the lower limit and upper limit.

[0055] Furthermore, in this specification, "parallel" does not refer to parallel in the strict sense, but rather to a range of ±5° from parallel.

[0056] Furthermore, in this specification, "orthogonal" and "perpendicular" do not refer to orthogonal and perpendicular in the strict sense, but rather to angles within the range of 90±5°.

[0057] In this specification, "(meth)acrylic acid" means "either or both of acrylic acid and methacrylic acid". "(meth)acryloyl" means "either or both of acryloyl and methacryloyl".

[0058] The bonding direction of the divalent group (e.g., -COO-) described in this specification is not particularly limited. For example, if L in XLY is -COO-, and the position bonded to the X side is set as *1 and the position bonded to the Y side is set as *2, then L can be *1-O-CO-*2 or *1-CO-O-*2.

[0059] [Anisotropic light absorption film]

[0060] The light-absorbing anisotropic film involved in this invention comprises a dichroic material and a liquid crystal compound, and has multiple regions with different directions of the transmittance central axis in the in-plane direction of the light-absorbing anisotropic film. 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 in the range of 0 to 70°, and satisfies any one of the following necessary conditions 1 to 3.

[0061] Necessary condition 1: Angle θ is 0° in at least one of the multiple regions.

[0062] Necessary condition 2: In at least two of the multiple regions, the orthogonal projection directions of the transmittance central axis onto the surface of the light-absorbing anisotropic film are the same, and in at least two regions, the angle θ is different.

[0063] Necessary condition 3: In at least two of the multiple regions, the angle θ is the same, and in at least two 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.

[0064] The transmittance center axis refers to the direction of highest transmittance when measuring transmittance by changing the tilt angle and tilt direction relative to the normal direction of the light-absorbing anisotropic film surface. The transmittance center axis is measured by irradiating the light-absorbing anisotropic film with P-polarized light at a wavelength of 550 nm using a UV-Vis-IR spectrophotometer (e.g., "JASCO V-670 / ARMN-735" (manufactured by JASCO Corporation)). The specific method is described below.

[0065] First, the direction in which the transmittance central axis is tilted relative to the normal to the surface of the anisotropic light absorption film is explored. More specifically, a sample of the anisotropic light absorption film is cut into a square, for example, 4 cm², and the resulting sample is placed on the stage of an optical microscope (e.g., Nikon Corporation, product name "ECLIPSE E600 POL") equipped with a linear polarizer on the light source side. Next, using a multichannel spectrometer (e.g., Ocean Optics, product name "QE65000"), the absorbance of the sample at a wavelength of 550 nm is monitored while the sample stage is rotated 1° clockwise, confirming the direction in which the absorbance is maximum. Based on this direction in which the absorbance is maximum within the sample surface, the angle θ of the anisotropic light absorption film is determined.

[0066] Next, in a plane containing the normal of the anisotropic light-absorbing film along the direction where its transmittance is maximum (including the transmittance central axis, a plane perpendicular to the layer surface), the angle θ (polar angle) relative to the normal of the surface of the anisotropic light-absorbing film is varied in 0.5° increments until 0–70°, while simultaneously irradiating with P-polarized light at a wavelength of 550 nm, and the transmittance of the anisotropic light-absorbing film is measured. The direction of highest transmittance obtained through this measurement is the transmittance central axis, and the angle θ between the transmittance central axis and the normal of the surface of the anisotropic light-absorbing film can be calculated.

[0067] Furthermore, since it was not possible to definitively confirm the direction in which absorbance is at its maximum during the initial measurement of angle φ, it was deduced that the direction of the transmittance central axis is along the normal direction of the surface of the anisotropic light absorption film. The aforementioned angle θ was measured on any surface containing the normal of the anisotropic light absorption film, and it was confirmed that angle θ is 0°.

[0068] Hereinafter, with reference to the accompanying drawings, the light absorption anisotropic film of the present invention will be described according to specific embodiments. However, the present invention is not limited to the following embodiments.

[0069] [First Embodiment]

[0070] As one embodiment of the light absorption anisotropic film involved in the present invention, a light absorption anisotropic film that satisfies the above-mentioned necessary condition 1 or the above-mentioned necessary condition 2 can be cited.

[0071] Figure 1A and Figure 1B (Hereinafter referred to as "Figure 1") is a conceptual diagram showing an example of the structure of the light-absorbing anisotropic film according to this embodiment.

[0072] The light-absorbing anisotropic film 10 shown in Figure 1 includes a dichroic material 1 and a liquid crystal compound (not shown). In the light-absorbing anisotropic film 10, a first region 11 and a second region 12 are arranged along the in-plane X-axis direction.

[0073] Figure 1A This is a top view of the anisotropic light absorption film 10, viewed from the normal direction of its surface. Furthermore, Figure 1B It is along Figure 1A The image shows a cross-sectional view of the light-absorbing anisotropic film 10 cut along line AA.

[0074] Among them, such as Figure 1A As shown, the long side direction (left-right direction of the paper) of the rectangular anisotropic light-absorbing film 10 in the in-plane direction is defined as the X-axis; the direction perpendicular to the X-axis (vertical direction of 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, in the X-axis, the direction towards the right side of the paper is defined as the positive direction; in the Y-axis, the direction towards the top of the paper is defined as the positive direction; and in the Z-axis, the direction from the paper towards the front is defined as the positive direction.

[0075] Furthermore, the angle θ (polar angle) between the direction of the transmittance central axis and the normal direction of the surface of the light absorption anisotropic film 10 is defined as follows: with the positive direction of the Z-axis as the reference (θ = 0°), it increases as it approaches the light absorption anisotropic film 10, and the angle θ = 90° in the in-plane direction of the light absorption anisotropic film 10.

[0076] Furthermore, the angle φ (azimuth angle) for the direction extending from the positive projection of the transmittance center axis within the plane of the anisotropic light absorption film 10 shown in Figure 1 is defined as follows: taking the direction extending in the negative direction of the X-axis as a reference (φ = 0°), the angle φ increases with clockwise rotation. Additionally, when... Figure 1B The inclination of the major axis of the dichroic substance 1 contained in the first region 11 of the structure is such that when the angle θ in a certain direction is 0°, the angle φ in that direction cannot be determined, and therefore does not exist.

[0077] In this specification, unless otherwise stated, the X-axis, Y-axis, Z-axis, angle θ, and angle φ shall be as specified above.

[0078] As shown in Figure 1, in the first region 11 and the second region 12 of the light absorption anisotropic film 10, the orientation direction of the dichroic material 1 is different in each region. More specifically, in the first region 11, the direction of the long axis of the dichroic material 1 is parallel to the Z-axis, and in the second region 12, the direction of the long axis of the dichroic material 1 is inclined at an angle θ from the positive direction of the Z-axis to the negative direction of the X-axis. Therefore, the light absorption anisotropic film 10 has a first region 11 where the angle θ between the transmittance central axis and the normal direction of the light absorption anisotropic film 10 is 0°, and a second region 12 where the angle θ between the transmittance central axis and the normal direction of the light absorption anisotropic film 10 exceeds 0°, thus satisfying necessary condition 1.

[0079] By applying this light-absorbing anisotropic film 10 to an image display device, it is easy to control areas with high visual recognition and areas with low visual recognition, thereby further improving the viewing angle controllability of the image display device.

[0080] For example, when from position A (reference) located on the front side of region 11 (normal direction of region 11) Figure 1B When observing the displayed image of an image display device with the light absorption anisotropic film 10 shown in Figure 1 attached, the transmittance center axis of the first region 11 and the transmittance center axis of the second region 12 are oriented towards position A. Therefore, the transmittance in both regions increases, and the visual recognizability of the displayed image in both regions is improved. On the other hand, when viewed from position B (reference position) located on the front of the second region 12 (normal direction of the second region 12), the transmittance in both regions increases. Figure 1B When observing the image displayed by the image display device with the light absorption anisotropic film 10 shown in Figure 1 attached, the transmittance of the first region 11 and the second region 12 is lower than the transmittance when observed from position A. Therefore, the visual recognizability of the displayed images in the two regions is also reduced.

[0081] Furthermore, as described above, the light absorption anisotropic film 10 shown in FIG1 has a first region 11 in which the angle θ between the transmittance central axis and the positive direction of the Z-axis is 0° and a second region 12 in which the angle θ between the transmittance central axis and the positive direction of the Z-axis exceeds 0°, thus satisfying the necessary condition 1.

[0082] As long as the angle θ is within the range of more than 0° and less than 70°, it is not particularly restricted and can be appropriately selected according to the applicable image display device. However, considering the superior field of view in practical use, it is preferred to be 1° to 60°, more preferably 5° to 40°, and even more preferably 8° to 45°.

[0083] In the light absorption anisotropic film 10 shown in FIG1, a method has been described in which there are two regions where the angle θ between the transmittance central axis and the normal direction of the light absorption anisotropic film 10 is 0° or greater than 0°. However, the light absorption anisotropic film involved in this embodiment is not limited to this method, and may also have three or more regions where the angle θ between the transmittance central axis and the normal direction of the light absorption anisotropic film is different.

[0084] Figure 2A and Figure 2B (Hereinafter referred to as "Figure 2") is a conceptual diagram showing another example of the structure of the light-absorbing anisotropic film involved in this embodiment.

[0085] The light-absorbing anisotropic film 20 shown in Figure 2 includes a dichroic material 1 and a liquid crystal compound (not shown). In the light-absorbing anisotropic film 20, a first region 21, a second region 22 and a third region 23 are arranged along the in-plane X-axis direction.

[0086] Figure 2A This is a top view of the anisotropic light absorption film 20, viewed from the normal direction of its surface. Furthermore, Figure 2B yes Figure 2A A cross-sectional view of the light-absorbing anisotropic film 20 in the AA line shown.

[0087] As shown in Figure 2, the orientation of the dichroic material 1 differs in each of the three regions (region 21, region 22, and region 23) of the anisotropic light-absorbing film 20. More specifically, in region 21, the major axis of the dichroic material 1 is parallel to the Z-axis, but in regions 22 and 23, the major axis of the dichroic material 1 tilts from the positive direction of the Z-axis towards the negative direction of the X-axis with angles θ1 and θ2, respectively. In this case, there exists a relationship where angle θ1 < angle θ2.

[0088] Therefore, the light absorption anisotropic film 20 has a first region 21 where the angle θ between the central axis of transmittance and the normal direction of the light absorption anisotropic film 20 is 0°, and a second region 22 and a third region 23 where the angle θ between the central axis of transmittance and the normal direction of the light absorption anisotropic film 10 exceeds 0°, thus satisfying the above-mentioned necessary condition 1.

[0089] Furthermore, in the second region 22 and the third region 23 of the light absorption anisotropic film 20, the positive projection direction of the transmittance center axis is the same negative direction of the X-axis, and the angle θ formed by the transmittance center axis and the normal direction of the light absorption anisotropic film 20 is different. Therefore, the light absorption anisotropic film 20 satisfies the above-mentioned necessary condition 2.

[0090] By applying this light-absorbing anisotropic film 20 to an image display device, it is easy to control areas with high visual recognition and areas with low visual recognition, thereby further improving the viewing angle controllability of the image display device.

[0091] For example, when from position A (reference) located on the front side of region 21 (normal direction of region 21) Figure 2B When observing the displayed image of an image display device with the light absorption anisotropic film 20 shown in Figure 2 attached, the transmittance center axes of the first region 21, the second region 22, and the third region 23 are oriented towards position A. Therefore, the transmittance in these regions is increased, and the visual recognizability of the displayed image in these regions is improved. On the other hand, when viewed from position B (reference point) located on the front side of the third region 23 (normal direction of the third region 23), the transmittance in these regions is increased. Figure 2B When observing the image displayed by the image display device with the light absorption anisotropic film 20 shown in Figure 2 attached, the transmittance of the first region 21, the second region 22 and the third region 23 are all lower than the transmittance when observed from position A. Therefore, the visual recognizability of the displayed image is lower in any region.

[0092] Furthermore, in the light absorption anisotropic film 20 shown in Figure 2, as it moves along the positive direction of the X-axis where the first region 21, the second region 22, and the third region 23 are arranged, the angle θ between the transmittance center axis and the normal direction of the light absorption anisotropic film 20 increases in stages.

[0093] Thus, in the light-absorbing anisotropic film, when the angle θ increases or decreases in stages or continuously as the film moves along the in-plane direction where multiple regions with different angles θ are arranged, the visual recognition of the image display device is superior and therefore preferred.

[0094] In addition, in this specification, "continuous increase" or "continuous decrease" means that in direction 1 within the plane, the increase or decrease in angle θ or angle φ per 1 cm continues within a range of 2°.

[0095] As described above, the light absorption anisotropic film 20 shown in FIG2 satisfies necessary condition 2. In a light absorption anisotropic film satisfying this necessary condition 2, there is no particular limitation as long as the angle θ formed by the transmittance central axis and the normal direction of the light absorption anisotropic film (angles θ1 and θ2 in the light absorption anisotropic film 20 shown in FIG2) is in the range of more than 0° and less than 70°. However, from the perspective of better visual recognition of the image display device, 1° to 60° is preferred, more preferably 5° to 40°. Even more preferably, 8° to 45° is preferred.

[0096] In the light absorption anisotropic film 10 shown in FIG1 and the light absorption anisotropic film 20 shown in FIG2, the method of the angle θ between the central axis of transmittance in each region and the normal direction of the light absorption anisotropic film is described in stages. However, the light absorption anisotropic film involved in this embodiment is not limited to this method, and the angle θ between the central axis of transmittance and the normal direction of the light absorption anisotropic film can be continuously varied.

[0097] Figure 3 This is a conceptual diagram illustrating another example of the structure of the light-absorbing anisotropic film involved in this embodiment.

[0098] Figure 3 The light-absorbing anisotropic film 30 shown comprises a dichroic material 1 and a liquid crystal compound (not shown). Among them, Figure 3 It is a cross-sectional view of the light-absorbing anisotropic film 30, taken along a plane that varies in inclination along the X-axis direction, which is the normal to the surface containing the light-absorbing anisotropic film 30 and the in-plane direction of the major axis of the dichroic material 1.

[0099] like Figure 3 As shown, the major axis of the dichroic substance 1 contained in the light-absorbing anisotropic film 30 is tilted at different angles relative to the normal direction of the light-absorbing anisotropic film 30, depending on its position in the X-axis direction within the plane. Furthermore, although not shown, the tilt of the major 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.

[0100] like Figure 3 As shown, the orientation of the dichroic material 1 varies depending on the position of the light-absorbing anisotropic film 30 along the X-axis. More specifically, in the central portion 30a of the light-absorbing anisotropic film 30 along the X-axis, the long axis of the dichroic material 1 is parallel to the Z-axis, but the inclination of the long axis of the dichroic material 1 continuously increases from the central portion 30a toward the end portion 30b of the light-absorbing anisotropic film 30 along the X-axis.

[0101] In the central part 30a of the light absorption anisotropic film 30, the angle θ between the central axis of transmittance and the normal direction of the light absorption anisotropic film 30 is 0°, thus satisfying the above-mentioned necessary condition 1.

[0102] Furthermore, in the region of the light absorption anisotropic film 30 other than the central portion 30a, the orthogonal projection direction of the transmittance central axis is the X-axis direction, and the angle θ formed by the transmittance central axis and the normal direction of the light absorption anisotropic film 30 is different. Therefore, the light absorption anisotropic film 30 satisfies the above-mentioned necessary condition 2.

[0103] By applying this light-absorbing anisotropic film 30 to an image display device, similar to the light-absorbing anisotropic films 10 and 20 described above, it is easy to control areas with high visual recognition and areas with low visual recognition, thereby further improving the viewing angle controllability of the image display device.

[0104] Moreover, in Figure 3 In the light absorption anisotropic film 30 shown, as the central portion 30a in the long side direction approaches the end portion 30b in the positive or negative direction of the X-axis, the angle θ between the central axis of transmittance and the normal direction of the light absorption anisotropic film 30 continuously increases.

[0105] Thus, from the perspective of better visual recognition of the image display device, it is more preferable to have a light absorption anisotropic film in which the angle θ continuously increases or decreases as the device moves along the in-plane direction where multiple regions with different angles θ are arranged.

[0106] In the light-absorbing anisotropic film according to this embodiment, multiple (more than two) regions with transmittance central axes having different angles θ relative to the normal direction of the surface of the light-absorbing anisotropic film can exist in the plane, and their number is not particularly limited. That is, the number of the above-mentioned regions can be more than two, preferably more than three. Moreover, as described above, the angle θ between the transmittance central axis and the normal direction of the surface of the light-absorbing anisotropic film is preferably a manner that changes continuously along the in-plane direction.

[0107] In the light-absorbing anisotropic film of this embodiment, the in-plane difference of the light-absorbing anisotropic film at the aforementioned angle θ is not particularly limited, but the difference between the minimum and maximum values ​​of the aforementioned angle θ in the in-plane of the light-absorbing anisotropic film is preferably 3 to 140°, more preferably 5 to 120°.

[0108] In Figure 1~ Figure 3 In the light absorption anisotropic film of the first embodiment shown, the orthogonal projection direction of the transmittance center axis (the orientation of the transmittance center axis in the in-plane direction) of each region is the same. However, as long as the light absorption anisotropic film involved in this embodiment has multiple regions that satisfy necessary condition 1 or necessary condition 2, it can further have regions with different orthogonal projection directions of the transmittance center axis.

[0109] [Second Implementation]

[0110] As another embodiment of the light-absorbing anisotropic film involved in the present invention, a light-absorbing anisotropic film that satisfies the above-mentioned necessary condition 3 can be cited.

[0111] Figure 4A and Figure 4B (Hereinafter referred to as "Figure 4") is a conceptual diagram showing an example of the structure of the light-absorbing anisotropic film according to the second embodiment.

[0112] The light-absorbing anisotropic film 40 shown in Figure 4 includes a dichroic material 1 and a liquid crystal compound (not shown). In the light-absorbing anisotropic film 40, a first region 41 and a second region 42 are arranged along the in-plane Y-axis direction.

[0113] Figure 4A This is a top view of the anisotropic light absorption film 40, viewed from the normal direction of its surface. Furthermore, Figure 4B yes Figure 4A The cross-sectional view of the light absorption anisotropic film 40 in the AA line shown. Figure 4C yes Figure 4A A cross-sectional view of the light-absorbing anisotropic film 40 in the BB line shown.

[0114] In addition, regarding the light absorption anisotropic film 40 shown in Figure 4, as... Figure 4A As shown, the direction of the shorter side of the rectangular anisotropic light-absorbing film 40 (the left-right direction of the paper) in the in-plane direction is defined as the X-axis; the direction perpendicular to the X-axis (the up-down direction of the paper) is defined as the Y-axis; and the normal direction of the light-absorbing anisotropic film 40 (the direction perpendicular to the paper) is defined as the Z-axis. Furthermore, as... Figure 4A As shown, in the X-axis, the direction towards the right side of the paper is set as the positive direction of the X-axis; in the Y-axis, the direction towards the top of the paper is set as the positive direction of the Y-axis; and in the Z-axis, the direction from the paper towards the front is set as the positive direction of the Z-axis.

[0115] As shown in Figure 4, in the first region 41 and the second region 42 of the light-absorbing anisotropic film 40, the orientation direction of the dichroic material 1 is different in each region. More specifically, in both the first region 41 and the second region 42, the major axis of the dichroic material 1 is tilted at an angle θ relative to the positive direction of the Z-axis. However, in the first region 41, the direction in which the major axis of the dichroic material 1 is projected onto the surface (XY plane) of the light-absorbing anisotropic film 40 is parallel to the negative direction of the X-axis. In contrast, in the second region 42, the direction in which the major axis of the dichroic material 1 is projected onto the surface (XY plane) of the light-absorbing anisotropic film 40 becomes a direction rotated clockwise at an angle φ from the negative direction of the X-axis in the XY plane.

[0116] Therefore, regarding the light absorption anisotropic film 40, the angle θ between the central axis of transmittance and the normal direction of the light absorption anisotropic film 40 is the same, and the orthogonal projection directions of the central axis of transmittance onto the surface of the light absorption anisotropic film 40 are different from each other, thus satisfying necessary condition 3.

[0117] By applying the light absorption anisotropic film 40 of the second embodiment shown in FIG4 to an image display device, similar to the light absorption anisotropic film of the first embodiment, it is possible to easily control areas with high visual recognition and areas with low visual recognition, and further improve the viewing angle controllability of the image display device.

[0118] At this time, the angle φ is not particularly limited and can be appropriately selected according to the applicable image display device. The maximum value of the difference in angle φ between the two regions with different angle φ is preferably 5 to 120°.

[0119] As an example of the applicability of an image display device equipped with the light-absorbing anisotropic film according to the second embodiment, a vehicle-mounted display such as a car navigation system can be installed in the interior components of a car, from the center of the dashboard (or central instrument cluster) to the center console located between the driver's seat and the passenger seat. In this case, it is possible to install the aforementioned image display device as a vehicle-mounted display in an area 30 to 40 cm in front of the vehicle, 30 to 40 cm horizontally, and 10 to 45 cm vertically below the driver's eye level. As a preferred embodiment of the light-absorbing anisotropic film according to the second embodiment for such an image display device, an angle φ of 0 to 30° (or 150 to 180°) is provided in the upper region of the light-absorbing anisotropic film of the image display device, and an angle φ of 40 to 70° (or 110 to 140°) is provided in the lower region of the light-absorbing anisotropic film.

[0120] Furthermore, the above method is merely one specific example, and the directions of angles θ and φ in each region of the light-absorbing anisotropic film can be appropriately changed according to the applicable conditions of the actual image display device.

[0121] In the light absorption anisotropic film 40 shown in FIG4, the method of having two regions with different orthogonal projection directions of the transmittance central axis has been described. However, the light absorption anisotropic film involved in this embodiment is not limited to this method, and may have three or more regions with different orthogonal projection directions of the transmittance central axis.

[0122] Furthermore, in the light absorption anisotropic film 40 shown in Figure 4, when the positive projection direction of the transmittance center axis in the first region 41 is set as the reference direction (φ = 0°), as the film moves along the negative direction of the Y-axis where the first region 41 and the second region 42 are arranged, the angle φ between the positive projection direction of the transmittance center axis and the reference direction increases in stages.

[0123] Thus, in the case where the angle θ of the light absorption anisotropic film is the same and the in-plane directions of at least two regions with different orthogonal projection directions along the central axis of transmittance are different, the visual recognition of the image display device is better when the angle φ increases or decreases in stages or continuously as it moves from the first region toward other regions besides the first region. Therefore, it is preferred.

[0124] Furthermore, the light-absorbing anisotropic film involved in this embodiment is not limited to the stepwise change of angle φ as shown in FIG4. As it moves along the in-plane direction with multiple regions having different angles φ, the angle φ can change continuously.

[0125] Furthermore, in the light absorption anisotropic film 40 shown in FIG4, the angle θ of the normal direction of the light absorption anisotropic film relative to the transmittance central axis in each region is the same. However, as long as the light absorption anisotropic film involved in this embodiment has multiple regions that satisfy the necessary condition 3, it can further have regions with different angles θ.

[0126] In the various anisotropic light-absorbing films shown in Figures 1 to 4, multiple regions with different directions of the transmittance central axis are arranged only in the in-plane direction 1. However, the anisotropic light-absorbing film of the present invention is not limited to this arrangement. For example, the anisotropic light-absorbing film of the present invention can be arranged in such a way that multiple regions with different directions of the transmittance central axis are arranged in the in-plane direction 1, and multiple regions with different directions of the transmittance central axis are also arranged in other in-plane directions.

[0127] Furthermore, in each of the light-absorbing anisotropic films shown in Figures 1 to 4, a plurality of dichroic materials 1 are arranged along the in-plane direction 1. However, this is a diagram used to illustrate the orientation state of the dichroic materials 1 and is not intended to limit the light-absorbing anisotropic film of the present invention to this manner.

[0128] To fabricate the light-absorbing anisotropic film according to the first and second embodiments described above, techniques for aligning the dichroic material to the desired orientation can be cited as methods for fabricating a polarizer using the dichroic material and techniques for fabricating a host-guest type liquid crystal cell. For example, the techniques used in the fabrication methods of the dichroic polarizing element described in Japanese Patent Application Publication No. 11-305036 and Japanese Patent Application Publication No. 2002-090526, and the methods for fabricating a host-guest type liquid crystal display device described in Japanese Patent Application Publication No. 2002-099388 and Japanese Patent Application Publication No. 2016-027387, are applicable.

[0129] To prevent changes in the light absorption characteristics of the anisotropic light absorption film caused by the operating environment, it is preferable to fix the orientation of the dichroic material through the formation of chemical bonds. For example, the orientation of the dichroic material can be fixed by polymerizing the host liquid crystal, the dichroic material, or polymerizable components added as needed.

[0130] A more specific method for manufacturing the aforementioned anisotropic light-absorbing film will be described later.

[0131] The composition and physical properties of the light-absorbing anisotropic film (hereinafter also referred to as "this light-absorbing anisotropic film") involved in the present invention will be described in detail below.

[0132] [Composition of anisotropic light-absorbing films]

[0133] This light-absorbing anisotropic film contains a dichroic material and a liquid crystal compound, and has multiple regions with different directions along at least one in-plane direction of the transmittance central axis.

[0134] There are no particular restrictions as long as the composition of the light-absorbing anisotropic film exhibits the above-mentioned characteristics, and any known components contained in the light-absorbing anisotropic film can be used.

[0135] (Dichroic substances)

[0136] In this specification, dichroic substances refer to pigments whose absorbance varies with direction. Dichroic substances can polymerize in anisotropic light absorption films.

[0137] Dichroic substances are not particularly limited. Examples include visible light absorbing substances (dichroic pigments), luminescent substances (fluorescent substances, phosphorescent substances), ultraviolet light absorbing substances, infrared light absorbing substances, nonlinear optical substances, carbon nanotubes, and inorganic substances (such as quantum rods). Known dichroic substances (dichroic pigments) can be used.

[0138] Specifically, examples include paragraphs

[0067] to

[0071] of Japanese Patent Application Publication No. 2013-228706, paragraphs

[0008] to

[0026] of Japanese Patent Application Publication No. 2013-227532, paragraphs

[0008] to

[0015] of Japanese Patent Application Publication No. 2013-209367, paragraphs

[0045] to

[0058] of Japanese Patent Application Publication No. 2013-014883, paragraphs

[0012] to

[0029] of Japanese Patent Application Publication No. 2013-109090, and Japanese Patent Application Publication No. 2013-101328. Paragraphs

[0009] to

[0017] of Japanese Patent Application Publication No. 2013-037353, paragraphs

[0051] to

[0065] of Japanese Patent Application Publication No. 2012-063387, paragraphs

[0049] to

[0073] of Japanese Patent Application Publication No. Hei 11-305036, paragraphs

[0016] to

[0018] of Japanese Patent Application Publication No. 2001-133630, paragraphs

[0009] to

[0011] of Japanese Patent Application Publication No. 2011-215337, paragraphs

[0030] to

[0169] of Japanese Patent Application Publication No. 2010-10624, and Japanese Patent Application Publication No. 2010-10624. Paragraphs

[0021] to

[0075] of Japanese Announcement No. 2, paragraphs

[0011] to

[0025] of Japanese Announcement No. 2010-215846, paragraphs

[0017] to

[0069] of Japanese Announcement No. 2011-048311, paragraphs

[0013] to

[0133] of Japanese Announcement No. 2011-213610, paragraphs

[0074] to

[0246] of Japanese Announcement No. 2011-237513, paragraphs

[0005] to

[0051] of Japanese Announcement No. 201, and International Publication No. 201 The dichroic substances described in paragraphs

[0005] to

[0041] of Publication No. 6 / 060173, paragraphs

[0008] to

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

[0014] to

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

[0014] to

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

[0013] to

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

[0014] to

[0034] of Publication No. 2018 / 164252.

[0139] In anisotropic light absorption films, two or more dichroic materials can be used simultaneously. For example, from the perspective of making the obtained anisotropic light absorption film close to black, it is preferable to use at least one dichroic material with a maximum absorption wavelength in the range of wavelengths above 370 nm and below 500 nm, and at least one dichroic material with a maximum absorption wavelength in the range of wavelengths above 500 nm and below 700 nm.

[0140] As described below, anisotropic light-absorbing films can be formed using a composition for forming anisotropic light-absorbing films. In the composition for forming anisotropic light-absorbing films, the dichroic material may have cross-linking groups. When the dichroic material has cross-linking groups, when forming anisotropic light-absorbing films using the composition for forming anisotropic light-absorbing films, the dichroic material in a predetermined orientation state can be immobilized.

[0141] Examples of crosslinking groups include (meth)acryloyl, epoxy, oxetyl, and styryl, with (meth)acryloyl being the most preferred.

[0142] The content of dichroic material in the light-absorbing anisotropic film is not particularly limited. When applied to an image display device, it is easy to control areas with high visual recognition and areas with low visual recognition. From the viewpoint of superior viewing angle control (hereinafter also referred to as "aspects of the invention with superior effects"), it is preferably 1 to 50% by mass relative to the total mass of the light-absorbing anisotropic film, more preferably 10 to 25% by mass.

[0143] (Liquid crystal compound)

[0144] This light-absorbing anisotropic film contains a liquid crystal compound. Therefore, it is possible to suppress the precipitation of dichroic substances and to orient the dichroic substances with a higher degree of orientation.

[0145] As the liquid crystal compound, either a high-molecular-weight liquid crystal compound or a low-molecular-weight liquid crystal compound can be used, but from the perspective of improving the degree of orientation, a high-molecular-weight liquid crystal compound is more preferred. Furthermore, both high-molecular-weight liquid crystal compounds and low-molecular-weight liquid crystal compounds can be used simultaneously as the liquid crystal compound.

[0146] "Polymer liquid crystal compound" refers to a liquid crystal compound that has repeating units in its chemical structure.

[0147] Here, "low molecular weight liquid crystal compound" refers to a liquid crystal compound that does not have repeating units in its chemical structure.

[0148] Examples of polymeric liquid crystal compounds include, for example, the thermotropic liquid crystal polymer described in Japanese Patent Application Publication No. 2011-237513 and the polymeric liquid crystal compounds described in paragraphs

[0012] to

[0042] of International Publication No. 2018 / 199096.

[0149] As a low-molecular-weight liquid crystal compound, examples include the liquid crystal compounds described in paragraphs

[0072] to

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

[0150] From the perspective of achieving a higher degree of orientation in the obtained anisotropic light absorption film, a polymeric liquid crystal compound comprising a repeating unit (hereinafter also simply referred to as "repeating unit (1)") represented by the following formula (1) is preferred as a liquid crystal compound.

[0151] [Chemical Formula 1]

[0152]

[0153] In the above formula (1), P1 represents the main chain of the repeating unit, L1 represents the single bond or divalent linking group, SP1 represents the spacer group, M1 represents the mesocrystalline group, and T1 represents the terminal group.

[0154] As the main chain of the repeating unit represented by P1, for example, groups represented by the following formulas (P1-A) to (P1-D) can be cited. Among them, from the perspective of the diversity of monomers that can be used as raw materials and ease of handling, groups represented by the following formula (P1-A) are preferred.

[0155] [Chemical Formula 2]

[0156]

[0157] In the above formulas (P1-A) to (P1-D), "*" indicates the bonding position with L1 in the above formula (1).

[0158] In the above equations (P1-A) to (P1-D), R 1 R 2 R 3 and R 4 Each of the above-mentioned alkyl groups independently represents a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. The alkyl group can be a straight-chain or branched alkyl group, or an alkyl group having a cyclic structure (cycloalkyl). Furthermore, the number of carbon atoms in the alkyl group is preferably 1 to 5.

[0159] The group represented by the above formula (P1-A) is preferably a unit of a partial structure of poly(meth)acrylate obtained by polymerization of (meth)acrylate.

[0160] The group represented by the above formula (P1-B) is preferably an ethylene glycol unit formed by ring-opening polymerization of the epoxy group of a compound having an epoxy group.

[0161] The group represented by the above formula (P1-C) is preferably a propylene glycol unit formed by ring-opening polymerization of an oxetane compound having an oxetane.

[0162] The group represented by the above formula (P1-D) is preferably a siloxane unit of a polysiloxane obtained by polycondensation of a compound having at least one of alkoxysilyl or silanol groups. Examples of compounds having at least one of alkoxysilyl or silanol groups include those having the formula SiR. 14 (OR 15 Compounds containing a group represented by )2-. In the formula, R 14 The meaning of R in (P1-D) 14 The meanings are the same, multiple R 15 Alkyl groups, which can be independently represented by 1 to 10 hydrogen or carbon atoms respectively.

[0163] In the above formula (1), L1 is a single bond or a divalent linking group.

[0164] Examples of divalent linking groups represented by L1 include -C(O)O-, -O-, -S-, and -C(O)NR. 3 -, -SO2- and -NR 3 R 4 -. In the formula, R 3 and R 4 Each can be independently represented by a hydrogen atom or an alkyl group having 1 to 6 carbon atoms that may have substituents.

[0165] When P1 is a group represented by formula (P1-A), from the perspective of increasing the orientation degree of the light absorption anisotropic film, L1 is preferably a group represented by -C(O)O-.

[0166] When P1 is a group represented by formulas (P1-B) to (P1-D), from the perspective of increasing the orientation degree of the light absorption anisotropic film, L1 is preferably a single bond.

[0167] In the above formula (1), from the perspective of easy liquid crystal properties or availability of raw materials, the spacer group represented by SP1 preferably includes at least one structure selected from the group consisting of ethylene oxide structure, propylene oxide structure, polysiloxane structure and fluorinated alkylene structure.

[0168] Among them, the oxyethylene structure represented by SP1 is preferably composed of *-(CH2-CH2O). n1 -* indicates a group. In the formula, n1 represents an integer from 1 to 20, and * represents the bonding position with L1 or M1 in the above formula (1). From the viewpoint of increasing the orientation degree of the light absorption anisotropic film, n1 is preferably an integer from 2 to 10, more preferably an integer from 2 to 4, and even more preferably 3.

[0169] Furthermore, considering the increased orientation degree of the light absorption anisotropic film, the oxypropylene structure represented by SP1 is preferably composed of *-(CH(CH3)-CH2O). n2 -* indicates a group. In the formula, n2 represents an integer from 1 to 3, and * indicates the bonding position with L1 or M1.

[0170] Furthermore, considering the increased orientation degree of the light absorption anisotropic film, the polysiloxane structure represented by SP1 is preferably composed of *-(Si(CH3)2-O). n3 -* indicates a group. In the formula, n3 represents an integer from 6 to 10, and * indicates the bonding position with L1 or M1.

[0171] Furthermore, considering the increased orientation degree of the light absorption anisotropic film, the fluorinated alkylene structure represented by SP1 is preferably composed of *-(CF2-CF2). n4 -* indicates a group. In the formula, n4 represents an integer from 6 to 10, and * indicates the bonding position with L1 or M1.

[0172] In the above formula (1), the mesocrystalline group represented by M1 is a group that represents the main framework of liquid crystal molecules that contribute to the formation of liquid crystals. Liquid crystal molecules exhibit liquid crystal properties in an intermediate state (intermediate phase) between the crystalline state and the isotropic liquid state. There are no particular limitations regarding the mesocrystalline group; for example, one can refer to "Flussige Kristalle in Tabellen II" (VEB Deutsche Verlag fur Grund stoff Industrie, Leipzig, 1984) (especially the records on pages 7 to 16) and the Liquid Crystal Handbook Editorial Committee, Liquid Crystal Handbook (Maruzen, 2000) (especially the records in Chapter 3).

[0173] As a mesocrystalline group, it is preferably a group having at least one cyclic structure selected from the group consisting of aromatic hydrocarbon groups, heterocyclic groups and alicyclic groups.

[0174] From the perspective of increasing the orientation degree of the light absorption anisotropic film, the mesocrystalline group preferably has aromatic hydrocarbon groups, more preferably has 2 to 4 aromatic hydrocarbon groups, and even more preferably has 3 aromatic hydrocarbon groups.

[0175] As a mesocrystalline group, considering aspects such as the manifestation of liquid crystal properties, adjustment of liquid crystal phase transition temperature, availability of raw materials and suitability for synthesis, as well as the increased orientation degree of light absorption anisotropic films, it is preferable to use a group represented by the following formula (M1-A) or the following formula (M1-B), and more preferably a group represented by formula (M1-B).

[0176] [Chemical Formula 3]

[0177]

[0178] 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, fluorinated alkyl, alkoxy, or substituents.

[0179] The divalent group represented by A1 is preferably a 4- to 6-membered ring. Furthermore, the divalent group represented by A1 can be a monocyclic ring or a fused ring.

[0180] * indicates the bonding position with SP1 or T1.

[0181] Examples of divalent aromatic hydrocarbon groups represented by A1 include phenylene, naphthylene, fluorene-diyl, anthracene-diyl, and tetraphenyl-diyl. Considering the diversity of mesocrystalline framework design or the availability of raw materials, phenylene or naphthylene is preferred, and phenylene is more preferred.

[0182] The divalent heterocyclic group represented by A1 can be either aromatic or non-aromatic, but from the perspective of further improving the degree of orientation, a divalent aromatic heterocyclic group is preferred.

[0183] Examples of atoms other than carbon that constitute a divalent aromatic heterocyclic group include nitrogen, sulfur, and oxygen atoms. In cases where an aromatic heterocyclic group has multiple atoms other than carbon forming the ring, these atoms can be the same or different.

[0184] Specific examples of divalent aromatic heterocyclic groups include, for example, pyridinyl (pyridin-diyl), pyridazinyl (pyridinyl), imidazole-diyl, thiophene (thiophene-diyl), quinolineyl (quinoline-diyl), isoquinolineyl (isoquinoline-diyl), oxazole-diyl, thiazole-diyl, oxadiazole-diyl, benzothiazole-diyl, benzothiadiazole-diyl, phthalimide-diyl, thienothiazole-diyl, thiazonothiazole-diyl, thienothiphene-diyl, and thienooxazole-diyl.

[0185] Specific examples of the divalent alicyclic group represented by A1 include cyclopentylene and cyclohexylene.

[0186] In the formula (M1-A), a1 represents an integer from 1 to 10. When a1 is 2 or higher, multiple A1 values ​​can be the same or different.

[0187] In formula (M1-B), A2 and A3 are each independently a divalent group 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 A1 in formula (M1-A), therefore their description is omitted.

[0188] In formula (M1-B), a2 represents an integer from 1 to 10. When a2 is 2 or more, multiple A2s can be the same or different, multiple A3s can be the same or different, and multiple LA1s can be the same or different. Considering that the orientation degree of the light absorption anisotropic film becomes higher, a2 is preferably an integer of 2 or more, and more preferably 2.

[0189] In formula (M1-B), when a2 is 1, LA1 is a divalent linking group. When a2 is 2 or more, each of the plurality of LA1s is independently a single bond or a divalent linking group, and at least one of the plurality of LA1s is a divalent linking group. When a2 is 2, considering that the orientation degree of the light absorption anisotropic film becomes higher, it is preferable that one of the two LA1s is a divalent linking group and the other is a single bond.

[0190] In formula (M1-B), examples of divalent linking groups represented by LA1 include -O- and -(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)-S-, -C(Z)=NN=C(Z')- (Z, Z', Z” independently represent a hydrogen atom, C1-C4 alkyl, cycloalkyl, aryl, cyano, or halogen atom, respectively.), -C≡C-, -N=N-, -S-, -S(O)-, -S(O)(O)-, -(O)S(O)O-, -O(O)S(O)O-, and -SC(O), etc. Among these, -C(O)O- is preferred from the perspective of increasing the orientation degree of the light absorption anisotropic film. LA1 can also be a group composed of two or more of these groups.

[0191] In the above formula (1), examples of terminal groups represented by T1 include hydrogen atoms, halogen atoms, cyano groups, nitro groups, hydroxyl groups, alkyl groups with 1 to 10 carbon atoms, alkoxy groups with 1 to 10 carbon atoms, alkylthio groups with 1 to 10 carbon atoms, alkoxycarbonyloxy groups with 1 to 10 carbon atoms, alkoxycarbonyl groups with 1 to 10 carbon atoms (ROC(O)-: R is alkyl), acyloxy groups with 1 to 10 carbon atoms, acylamino groups with 1 to 10 carbon atoms, alkoxycarbonylamino groups with 1 to 10 carbon atoms, sulfonylamino groups with 1 to 10 carbon atoms, aminosulfonyl groups with 1 to 10 carbon atoms, carbamoyl groups with 1 to 10 carbon atoms, thionyl groups with 1 to 10 carbon atoms, urea groups with 1 to 10 carbon atoms, and groups containing (meth)acryloyloxy groups. As an example of the group containing (meth)acryloyloxy, one can cite a group represented by -LA (L can be a single bond or a linking group. Specific examples of linking groups are the same as L1 and SP1 above. A represents (meth)acryloyloxy).

[0192] From the perspective of increasing the orientation degree of the light absorption anisotropic film, T1 is preferably an alkoxy group with 1 to 10 carbon atoms, more preferably an alkoxy group with 1 to 5 carbon atoms, and even more preferably a methoxy group.

[0193] These terminal groups can be further replaced by these groups or polymeric groups as described in Japanese Patent Application Publication No. 2010-244038.

[0194] From the perspective of improving the adhesion to adjacent layers and enhancing the cohesiveness of the membrane, T1 is preferably a polymerizable group.

[0195] There are no particular limitations on the polymerizable groups, but polymerizable groups capable of undergoing free radical polymerization or cationic polymerization are preferred.

[0196] As a free radical polymerizable group, known polymerizable groups can be used. Acryloyl or methacryloyl are examples of preferred polymerizable groups. In this case, acryloyl is known to have a faster polymerization rate, and from the viewpoint of improving productivity, acryloyl is preferred, but methacryloyl can also be used as a polymerizable group.

[0197] As the cationic polymerizable group, known cationic polymerizable groups can be used, such as alicyclic ether groups, cyclic acetal groups, cyclic lactone groups, cyclic thioether groups, spiroacetate groups, and ethyleneoxy groups. Among these, alicyclic ether groups or ethyleneoxy groups are preferred, and epoxy groups, oxetyl groups, or ethyleneoxy groups are even more preferred.

[0198] From the perspective of increasing the orientation degree of the light absorption anisotropic film, the weight-average molecular weight (Mw) of the polymer liquid crystal compound containing the repeating unit represented by the above formula (1) is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. If the Mw of the polymer liquid crystal compound is within the above range, the polymer liquid crystal compound is easier to process.

[0199] In particular, from the perspective 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 10,000 to 300,000.

[0200] Furthermore, considering the temperature tolerance of orientation, the weight-average molecular weight (Mw) of the polymer liquid crystal compound is preferably less than 10,000, and more preferably 2,000 or more but less than 10,000.

[0201] The weight-average molecular weight and number-average molecular weight in this specification are values ​​determined by gel permeation chromatography (GPC).

[0202] • Solvent (eluent): N-methylpyrrolidone

[0203] • Device Name: TOSOH HLC-8220GPC

[0204] • String: Connect 3 TOSOH TSKgelSuperAWM-H (6mm×15cm) tubes for use.

[0205] • Column temperature: 25℃

[0206] • Sample concentration: 0.1% by mass

[0207] • Flow rate: 0.35 mL / min

[0208] • Calibration curves: Calibration curves for seven samples of TSK standard polystyrene manufactured by TOSOH CORPORATION, with Mw values ​​ranging from 2,800,000 to 1,050 (Mw / Mn = 1.03 to 1.06).

[0209] The liquid crystal compound can be used alone or in combination with two or more. This anisotropic light-absorbing film preferably contains two or more liquid crystal compounds.

[0210] From the perspective of further improving the effect of the present invention, the content of liquid crystal compound contained in the light-absorbing anisotropic film is preferably 50 to 99% by mass relative to the total mass of the light-absorbing anisotropic film, more preferably 75 to 90% by mass.

[0211] (Other ingredients)

[0212] Anisotropic light-absorbing films may also contain other components besides those mentioned above. Examples of such other components include surface modifiers, vertical alignment agents, and leveling agents.

[0213] -Surface Modifier-

[0214] As a surface modifier contained in anisotropic light-absorbing films, there are no particular restrictions, and known polymeric and low-molecular-weight surface modifiers can be used.

[0215] As a surface modifier, the compounds described in paragraphs

[0253] to

[0293] of Japanese Patent Application Publication No. 2011-237513 can be used.

[0216] Furthermore, as a surface modifier, fluoro(meth)acrylate polymers described in paragraphs

[0018] to

[0043] of Japanese Patent Application Publication No. 2007-272185 can also be used.

[0217] Furthermore, as a surface modifier, compounds described in paragraphs

[0079] to

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

[0020] to

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

[0022] to

[0029] ), and liquid crystal orientation promoters represented by formula (4) described in Japanese Patent Application Publication No. 2002-129162 can also be used. The compounds described in the

[0076] to

[0078] and

[0082] to

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

[0092] to

[0096] sections), the compounds described in the

[0013] to

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

[0018] to

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

[0019] to

[0038] sections of Japanese Patent No. 4895088.

[0218] A single surface modifier can be used alone, or two or more can be used simultaneously.

[0219] When the light-absorbing anisotropic film contains a surface modifier, the content of the surface modifier is preferably 0.001 to 5 parts by mass relative to the total of 100 parts by mass of the dichroic substance and the liquid crystal compound. When multiple surface modifiers are used simultaneously, the total amount of the multiple surface modifiers is preferably within the above range.

[0220] -Vertical Orientation Agent-

[0221] Boric acid compounds and onium salts can be cited as vertical orientation agents.

[0222] As a boric acid compound, the compound represented by formula (A) is preferred.

[0223] Formula (A)

[0224] [Chemical Formula 4]

[0225]

[0226] In equation (A), R 1 and R 2 Each of these can be independently represented as a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroatom-containing cyclic group.

[0227] R 3 This indicates a substituent containing a (meth)acrylic acid group.

[0228] As a specific example of a boric acid compound, one can cite the boric acid compound represented by general formula (I) described in paragraphs

[0023] to

[0032] of Japanese Patent Application Publication No. 2008-225281.

[0229] The following compounds are also preferred as boric acid compounds.

[0230] [Chemical Formula 5]

[0231]

[0232] As an onium salt, the preferred option is a compound represented by formula (B).

[0233] Formula (B)

[0234] [Chemical Formula 6]

[0235]

[0236] In formula (B), ring A represents a quaternary ammonium ion composed of a nitrogen-containing heterocycle. X - Indicates anion. L 1 This indicates a divalent linker group. L 2 Indicates a single bond or a divalent linking group. Y1 The symbol indicates a divalent linking group having a 5- or 6-membered ring as part of the structure. Z indicates a divalent linking group having a 2-20 alkylene group as part of the structure. P 1 and P 2 Each of these represents a monovalent substituent having a polymerizable olefinic unsaturated bond.

[0237] Specific examples of onium salts include those described in paragraphs

[0052] to

[0058] of Japanese Patent Application Publication No. 2012-208397, those described in paragraphs

[0024] to

[0055] of Japanese Patent Application Publication No. 2008-026730, and those described in Japanese Patent Application Publication No. 2002-037777.

[0238] When the light-absorbing anisotropic film contains a liquid crystal compound and a vertical alignment agent, the content of the vertical alignment agent relative to the total mass of the liquid crystal compound is preferably 0.1 to 400% by mass, more preferably 0.5 to 350% by mass.

[0239] Vertical alignment agents can be used alone or in combination of two or more. When using two or more vertical alignment agents, it is preferable that their combined dosage is within the range described above.

[0240] -Leveling agent-

[0241] The light-absorbing anisotropic film may also contain a leveling agent. When the light-absorbing anisotropic film forming composition (light-absorbing anisotropic film) described later contains a leveling agent, the roughness of the surface caused by the drying wind applied to the surface of the light-absorbing anisotropic film is suppressed, thereby allowing the dichroic material to be oriented more uniformly.

[0242] The leveling agent is not particularly limited, but is preferably a leveling agent containing fluorine atoms (fluorine-based leveling agent) or a leveling agent containing silicon atoms (silicone-based leveling agent), and more preferably a fluorine-based leveling agent.

[0243] Examples of fluorinated leveling agents include fatty acid esters of polycarboxylic acids in which a portion of the fatty acid is replaced by a fluorinated alkyl group, and polyacrylates with fluorinated substituents.

[0244] Specific examples of leveling agents include the compounds illustrated in paragraphs

[0046] to

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

[0038] to

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

[0245] When the light-absorbing anisotropic film contains a liquid crystal compound and a leveling agent, the content of the leveling agent relative to the total mass of the liquid crystal compound is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass.

[0246] Leveling agents can be used alone or in combination of two or more. When using two or more leveling agents, it is preferable that their combined dosage is within the range described above.

[0247] (Composition for forming anisotropic light absorption films)

[0248] The light-absorbing anisotropic film is preferably formed using a composition for forming a light-absorbing anisotropic film containing a dichroic substance and a liquid crystal compound.

[0249] The composition for forming anisotropic light absorption films preferably includes, in addition to a dichroic substance and a liquid crystal compound, a solvent described later. The composition for forming anisotropic light absorption films may further include other components.

[0250] Other components include, for example, the surface modifiers, vertical orientation agents, leveling agents, polymerization initiators, and polymerizable components described below.

[0251] Examples of dichroic substances included in compositions for forming anisotropic light-absorbing films include dichroic substances included in anisotropic light-absorbing films.

[0252] The content of the dichroic substance relative to the total solid content of the composition for forming anisotropic light absorption films is preferably the same as the content of the dichroic substance relative to the total mass of the anisotropic light absorption film.

[0253] The term "total solids content in the composition for forming anisotropic light-absorbing films" refers to components other than solvents. Specific examples of solids include dichroic substances, liquid crystal compounds, and the other components mentioned above.

[0254] The liquid crystal compound, surface modifier, vertical alignment agent, and leveling agent contained in the composition for forming anisotropic light-absorbing films are the same as those contained in the anisotropic light-absorbing films.

[0255] The contents of the liquid crystal compound, surface modifier, vertical alignment agent, and leveling agent relative to the total solid content of the composition for forming anisotropic light absorption films are preferably the same as the contents of the liquid crystal compound, surface modifier, vertical alignment agent, and leveling agent relative to the total mass of the anisotropic light absorption film.

[0256] From an operational perspective, the composition for forming anisotropic light-absorbing films preferably contains a solvent.

[0257] Examples of solvents include ketones, ethers, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, carbon halides, esters, alcohols, cellosols, cellosol acetates, sulfoxides, amides, and heteroatom-containing cyclic compounds, as well as water.

[0258] These solvents can be used individually or in combination with two or more solvents.

[0259] Among these solvents, organic solvents are preferred, and carbon halogens or ketones are more preferred.

[0260] When the composition for forming anisotropic light absorption films contains a solvent, the solvent content relative to the total mass of the composition for forming anisotropic light absorption films is preferably 80 to 99% by mass, more preferably 83 to 97% by mass, and even more preferably 85 to 95% by mass.

[0261] Compositions for forming anisotropic light-absorbing films may contain a polymerization initiator.

[0262] There are no particular restrictions on the polymerization initiator, but photosensitive compounds, i.e., photopolymerization initiators, are preferred.

[0263] Commercially available products can also be used as photopolymerization initiators, such as IR GACURE (registered trademark) 184, IRGACURE 907, IRGACURE 369, IRGACURE 651, IRGACURE 819, IRGACUREOXE-01 and IRGACURE OXE-02 manufactured by BASF.

[0264] Polymerization initiators can be used alone or in combination with two or more.

[0265] When the composition for forming anisotropic light-absorbing films contains a polymerization initiator, the content of the polymerization initiator relative to the total solid content of the composition for forming anisotropic light-absorbing films is preferably 0.01 to 30% by mass, more preferably 0.1 to 15% by mass.

[0266] Compositions for forming anisotropic light-absorbing films may contain polymerizable components.

[0267] Examples of polymerizable components include compounds containing acrylates (e.g., acrylate monomers). When using compounds containing acrylates, the light-absorbing anisotropic film comprises a polyacrylate obtained by polymerizing the aforementioned acrylate-containing compound.

[0268] Furthermore, as a polymerizable component, the compound described in paragraph

[0058] of Japanese Patent Application Publication No. 2017-122776 can also be cited.

[0269] When the composition for forming anisotropic light-absorbing films contains a polymerizable component, the content of the polymerizable component is preferably 3 to 20 parts by mass relative to the total of 100 parts by mass of the dichroic substance and the liquid crystal compound in the composition for forming anisotropic light-absorbing films.

[0270] [Method for manufacturing anisotropic light-absorbing films]

[0271] As long as the method for manufacturing anisotropic light absorption films is capable of forming multiple regions with different directions of the transmittance central axis arranged in the in-plane direction, the method for manufacturing anisotropic light absorption films that satisfies the above-mentioned necessary conditions 1 to 3 is not particularly limited and can be manufactured using known methods.

[0272] A method for manufacturing anisotropic light-absorbing films may include, in sequence, a step (hereinafter also referred to as a "specifically oriented film") of forming an oriented film (hereinafter also referred to as a "specifically oriented film forming step") of forming an oriented film with multiple regions having different orientation limiting forces in the in-plane direction; a step (hereinafter also referred to as a "coating film forming step") of coating the aforementioned anisotropic light-absorbing film forming composition onto the obtained specificly oriented film; and a step (hereinafter also referred to as a "alignment step") of orienting the liquid crystal components contained in the coating film.

[0273] In addition, liquid crystal components refer to components that not only contain the aforementioned liquid crystal compounds but also contain dichroic substances with liquid crystal properties.

[0274] The following describes a method for manufacturing anisotropic light absorption films, using examples including the aforementioned specific orientation film formation process, coating film formation process, and orientation process. However, the method for manufacturing anisotropic light absorption films is not limited to the methods described below.

[0275] <Specific Orientation Film Formation Process>

[0276] The specific orientation film forming process is a process of forming a specific orientation film having an orientation restraining force that orients the liquid crystal components that can be included in the light absorption anisotropic film forming composition, and having multiple regions with different directions of the orientation restraining force disposed in the plane.

[0277] Methods for forming a specific orientation film include, for example, rubbing the film surface with an organic compound (preferably a polymer), forming a layer with microgrooves, and imparting an electric field, a magnetic field, or imparting orientation functionality through light irradiation.

[0278] As a specific alignment film forming process, considering the ease of controlling the pretilt angle of the alignment film, it is preferable to form the alignment film by friction treatment. Considering the uniformity of the alignment and the ease of forming multiple regions with different directions of the alignment restraint force, it is preferable to form a photo-alignment film by light irradiation, and more preferably, a photo-alignment film is formed.

[0279] As a photoalignment film formed by light irradiation, there are no particular restrictions as long as it is an alignment film that imparts an alignment constraint force in a specified direction. The materials used to form the photoalignment film are not particularly limited; for example, a photoalignment film forming composition containing a photoalignment agent can be used to form the photoalignment film.

[0280] Photoalignment agents are compounds with photoalignment groups, and there are no particular restrictions as long as the material is given orientation constraint force through the orientation treatment described later.

[0281] Examples of photoorientation groups include those that induce rearrangement or anisotropic chemical reactions by irradiation with anisotropic light (e.g., plane-polarized light). Specifically, a photoorientation group is a group that, by irradiation with light (e.g., linearly polarized light), induces at least one photoreaction selected from photoisomerization, photodimerization, and photodecomposition, thereby changing the molecular structure of the group. Among these, groups that induce photoisomerization (groups with photoisomerization structures) or groups that induce photodimerization (groups with photodimerization structures) are preferred, considering excellent orientation uniformity, thermal stability, and chemical stability.

[0282] Photoisomerization is a reaction that uses light to induce stereoisomerization or structural isomerization. As photo-orienting agents with groups that induce photoisomerization reactions, for example, there are substances with an azobenzene structure (K. Ichimura et al., Mol. Cryst. Liq. Cryst., 298, p. 221 (1997)), substances with a hydrazine-β-ketoester structure (S. Yamamura et al., Liquid Crystals, Vol. 13, No. 2, p. 189 (1993)), substances with a stilbene structure (JGVictor and JMTorkelson, Macromolecules, 20, p. 2241 (1987)), groups with a cinnamic acid (cinnamyl) structure (skeleton), and substances with a spiropyran structure (K. Ichimura et al., Chemistry Letters, p. 1063 (1992); K. Ichimura et al., Thin Solid Films, Vol. 235, p. 101 (1993)).

[0283] The group that initiates the photoisomerization reaction is preferably a group containing a C=C bond or an N=N bond. Examples of such groups include those with an azobenzene structure (skeleton), a hydrazine-β-ketoester structure (skeleton), a stilbene structure (skeleton), a cinnamic acid (cinnamoyl) structure (skeleton), and a spiropyran structure (skeleton). Preferably, the group has an azobenzene structure, a cinnamoyl structure, or a coumarin structure; more preferably, it has an azobenzene structure or a cinnamoyl structure.

[0284] The aforementioned photodimerization reaction refers to the addition reaction between two groups caused by the action of light, typically referring to the reaction that forms a ring structure. Examples of photo-aligning agents containing groups that induce photodimerization include substances with a cinnamic acid structure (M. Schadt et al., J. Appl. Phys., Vol. 31, No. 7, p. 2155 (1992)), substances with a coumarin structure (M. Schadt et al., Nature., Vol. 381, p. 212 (1996)), substances with a chalcone structure (Ogawa et al., Proceedings of the Liquid Crystal Symposium, 2AB03 (1997)), and substances with a benzophenone structure (YKJang et al., SID Int. Symposium Digest, p. 53 (1997)).

[0285] Examples of groups that can initiate photodimerization include 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). Preferably, groups having a cinnamoyl structure or a coumarin structure are used, and more preferably, groups having a cinnamoyl structure are used.

[0286] The photoaligning agent preferably has crosslinking groups.

[0287] As the crosslinking group, preferably it is a thermal crosslinking group that causes a curing reaction by heat or a photocrosslinking group that causes a curing reaction by light. It can also be a crosslinking group having either a thermal crosslinking group or a photocrosslinking group. More specifically, examples of crosslinking groups include hydroxyl, carboxyl, amino, free radical polymerizable groups (e.g., acryloyl, methacryloyl, vinyl, styryl, and allyl) and cationic polymerizable groups (e.g., epoxy, epoxycyclohexyl, and oxetane).

[0288] As a photoorientation agent, a polymer having photoorientation groups can be preferred. From the viewpoint of achieving close bonding between the photoorientation film and the photoabsorption anisotropic film, a polymer having photoorientation groups with hydrophobicity close to that of the photoabsorption anisotropic film is more preferred.

[0289] Examples of polymers having photooriented groups include, for instance, Japanese Patent Application Publication Nos. 6-289374, 10-506420, 2009-501238, 2012-078421, 2015-106062, and 2016-079189, as well as Japanese Patent Application Publication Nos. 2012-037868 and 2014. The photooriented polysiloxanes described in Japanese Patent Application Publication No. 026261, Japanese Patent Application Publication No. 2015-026050, the photooriented polystyrene-acrylate copolymers described in Japanese Patent Application Publication No. 2015-151548, Japanese Patent Application Publication No. 2015-151549, Japanese Patent Application Publication No. 2016-098249, and the photooriented polynorbornene polymers described in Japanese Patent Application Publication No. 2012-027471 and Japanese Patent Application Publication No. 2015-533883, etc.

[0290] There is no particular limitation on the content of the alignment agent contained in the composition for forming photo-aligned films, but it is preferably 0.1 to 50 parts by mass relative to 100 parts by mass of the solvent described later, and more preferably 0.5 to 10 parts by mass.

[0291] From the viewpoint of operability in fabricating photo-aligned films, the composition for forming photo-aligned films preferably includes a solvent. Examples of solvents include water and organic solvents. Examples of organic solvents include those that can be included in the aforementioned composition for forming anisotropic light-absorbing layers.

[0292] One solvent can be used alone, or two or more solvents can be used at the same time.

[0293] The composition for forming photo-aligned films may contain other components besides those described above. Examples of such other components include, for instance, acid-generating agents, crosslinking catalysts, adhesion modifiers, leveling agents, surfactants, and plasticizers.

[0294] The method for forming a specific orientation film by light irradiation will be described below with reference to the accompanying drawings.

[0295] The method of forming an alignment film by light irradiation is not particularly limited. For example, methods with the following processing can be described: coating processing, in which the above-mentioned composition for forming an alignment film is coated on the surface of a substrate to form a coating film; and light alignment processing, in which the formed coating film is irradiated with polarized light or unpolarized light to form a specific alignment film.

[0296] (Coating treatment)

[0297] Coating is a process of applying a composition for photo-aligned film formation onto the surface of a substrate to form a coated film.

[0298] The coating method for the composition for photo-aligned film formation is not limited, and examples include roller coating, gravure printing, spin coating, wire rod coating, extrusion coating, direct gravure coating, reverse gravure coating, mold coating, spray coating, and inkjet coating.

[0299] In the coating process, transparent resin films, which will be described later, can be used as substrates for compositions used to form photo-aligned films.

[0300] (Optical alignment process)

[0301] A coated film formed by coating process is subjected to photo-orientation treatment by irradiating it with polarized or unpolarized light, thereby forming a film with a specific orientation.

[0302] The light source used for light orientation processing can be various light sources such as infrared, visible light or ultraviolet light, but ultraviolet light is preferred.

[0303] Furthermore, when polarized light is irradiated during the photoalignment process, the irradiation direction can be either the normal direction to the coating film surface or a direction inclined relative to the coating film surface. When unpolarized light is irradiated during the photoalignment process, the irradiation direction is an inclined direction relative to the coating film surface.

[0304] The photo-alignment process involves irradiating the above-mentioned coating film with polarized or unpolarized light, which has different incident directions relative to the coating film depending on its position in the plane, thereby forming an alignment film with multiple regions of different orientations and orientation limiting forces.

[0305] In optical orientation processing, polarized light is preferred, and polarized ultraviolet light is even more preferred.

[0306] refer to Figure 5A , Figure 5B and Figure 5C (Hereinafter referred to as "Figure 5") The light orientation process will be explained in more detail.

[0307] Figure 5 is a conceptual diagram showing one embodiment of the photo-alignment treatment of the coating film of the composition for forming an alignment film. Additionally, regarding Figure 5... Figure 7The X-axis, Y-axis, Z-axis, angle θ, and angle φ are represented as described in the explanation of Figure 1.

[0308] Figure 5 is a perspective view of the coating film 50 of the alignment film forming composition formed in the above-described coating process, viewed from an oblique top. Furthermore, the coating film 50 is formed on the surface of a substrate (not shown). Figure 5A As shown, the coated film 50 is divided into two regions by boundary lines L that are equidistant from both ends in the X-axis direction: the first region 51 on the negative X-axis direction side (left side of the paper) and the second region 52 on the positive X-axis direction side (right side of the paper).

[0309] As a light orientation process, firstly, such as Figure 5B As shown, the mask M is positioned above the second region 52 of the coating film 50, thereby shielding only the second region 52 and exposing the first region 51. Polarized light is irradiated onto the exposed first region 51 from a first direction. Figure 5B In the diagram, the first direction is the positive direction of the Z-axis (the direction with angle θ = 0°).

[0310] Next, as Figure 5C As shown, the mask M is moved above the first region 51, thereby shielding only the first region 51 and exposing the second region 52. Polarized light is then irradiated onto the exposed second region 52 from the second direction. Figure 5C In the diagram, the second direction is the direction that is inclined at 35° from the positive direction of the Z-axis toward the negative direction of the X-axis (angle θ = 35° and angle φ = 0°).

[0311] After irradiating the second region 52, the mask M is removed, thereby forming specific orientation films with different orientation constraint directions in the first region 51 and the second region 52, respectively.

[0312] The specific orientation film formed by the above photo-orientation treatment is subjected to a coating film formation process and an orientation process, thereby obtaining the light absorption anisotropic film 10 shown in FIG1.

[0313] In the photo-alignment process shown in Figure 5, the two regions formed by dividing the coating film 50 into two equal parts in the X-axis direction are irradiated with light from different incident directions. However, the photo-alignment process is not limited to this method. The coating film can be divided into three or more regions in the plane, and each region can be irradiated with light from different incident directions.

[0314] Figure 6A , Figure 6B and Figure 6C (Hereinafter referred to as “Figure 6”.) is a conceptual diagram illustrating another example of light orientation processing.

[0315] Figure 6 is a perspective view of the coating film 60 of the alignment film forming composition formed in the above coating process, viewed from an oblique top. The coating film 60 is formed on the surface of a substrate (not shown). The coating film 60 shown in Figure 6 is divided into three regions along the X-axis, from the negative X-axis direction: region 61, region 62, and region 63.

[0316] As a light orientation process, firstly, such as Figure 6A As shown, the first region 61 is exposed by shading the second region 62 and the third region 63 by arranging the mask M above the second region 62 and the third region 63 covering the coating film 60. Polarized light is then irradiated onto the exposed first region 61 from a first direction. Figure 6A In the diagram, the first direction is the positive direction of the Z-axis (the direction with angle θ = 0°).

[0317] Next, as Figure 6B As shown, by placing two masks M above regions 61 and 63 respectively, regions 61 and 63 are shielded from light, thus exposing region 62. Polarized light is then irradiated onto the exposed region 62 from a second direction. Figure 6B In the diagram, the second direction is the direction that is inclined at 15° from the positive direction of the Z-axis toward the negative direction of the X-axis (angle θ = 15° and angle φ = 0°).

[0318] Next, as Figure 6C As shown, by positioning the mask M above the first region 61 and the second region 62 respectively, the first region 61 and the second region 62 are shielded from light, thus exposing the third region 63. Polarized light is then irradiated onto the exposed third region 63 from a third direction. Figure 6C In the diagram, the third direction is the direction that is inclined at 30° from the positive direction of the Z-axis toward the negative direction of the X-axis (angle θ = 35° and angle φ = 0°).

[0319] After irradiating the third region 63, the mask M is removed, thereby forming specific orientation films with different orientation constraint directions in the first region 61, the second region 62 and the third region 63 respectively.

[0320] The specific orientation film formed by the above photo-orientation treatment is subjected to a coating film formation process and an orientation process, thereby obtaining the light absorption anisotropic film 20 shown in Figure 2.

[0321] The optical orientation process is not limited to the method of forming a specific orientation film in which the direction of the orientation constraint force changes in stages according to the position in the plane, as described above, but can also be a method of forming a specific orientation film in which the direction of the orientation constraint force changes continuously.

[0322] refer to Figure 7Other embodiments of the optical orientation process will be described. Figure 7 This is a conceptual diagram illustrating another embodiment of the photo-alignment process, and is a front view of the coating film 70 of the alignment film forming composition formed in the above-described coating process, viewed from the negative Y-axis direction. The coating film 70 is formed on the surface of a substrate (not shown).

[0323] like Figure 7 As shown, the coating film 70 is bent into an inverted U-shape. Thus, polarized light is irradiated onto the coating film 70, whose surface is convex from the positive Z-axis direction (the direction with angle θ = 0°). Consequently, the angle of incidence of the polarized light relative to the surface of the bent coating film 70 continuously varies depending on the position of the coating film 70 along the X-axis. After alignment, by restoring the coating film 70 to a planar shape, a specific alignment film is formed in which the direction (angle θ) of the alignment constraint force continuously varies along the X-axis direction.

[0324] By performing a coating film formation process and an orientation process on the specifically oriented film obtained above, one can obtain... Figure 3 The light-absorbing anisotropic film 30 shown is an example.

[0325] refer to Figure 8A and Figure 8B (Hereinafter referred to as "Fig. 8"), other embodiments of the light orientation process will be described. Furthermore, the X-axis, Y-axis, Z-axis, angle θ, and angle φ shown in Fig. 8 are as described in the explanation of Fig. 4.

[0326] Figure 8 is a conceptual diagram illustrating another embodiment of the photo-alignment process, and is a perspective view of the coating film 80 of the alignment film forming composition formed in the above-described coating process, viewed from an obliquely upward angle. The coating film 80 is formed on the surface of a substrate (not shown). The coating film 80 is divided into two regions by boundary lines spaced equidistant from both ends in the Y-axis direction: a first region 81 on the positive Y-axis direction side (upper side of the paper) and a second region 82 on the negative Y-axis direction side (lower side of the paper).

[0327] As a light orientation process, firstly, such as Figure 8A As shown, the mask M is configured to cover the second region 82, thereby shielding only the second region 82 and exposing the first region 81. Polarized light is then irradiated onto the exposed first region 81 from a first direction. Figure 8A In the diagram, the first direction is the direction that is inclined at 30° from the positive direction of the Z-axis toward the negative direction of the X-axis (angle θ = 30° and angle φ = 0°).

[0328] Next, as Figure 8BAs shown, by moving the mask M above the first region 81 covering the coating film 80, only the first region 81 is shaded, thus exposing the second region 82. Polarized light is then irradiated onto the exposed second region 82 from the second direction. Figure 8B In the middle, the second direction is the direction that is inclined by 30° from the positive direction of the Z-axis toward the direction with an angle φ of 50° in the XY plane (the direction with angle θ = 30°).

[0329] After irradiating the second region 82, the mask M is removed, thereby forming specific orientation films with different orientation constraint forces in the first region 81 and the second region 82, respectively.

[0330] The specific orientation film formed by the above photo-orientation treatment is subjected to a coating film formation process and an orientation process to obtain the light absorption anisotropic film 40 shown in Figure 4.

[0331] The light orientation processing is not limited to the embodiments shown in Figures 5 to 8 above, and can be appropriately selected according to the configuration of multiple regions with different directions of the central axis of transmittance in the target light absorption anisotropic film.

[0332] The thickness of the specific orientation film formed by the specific orientation film forming process is not particularly limited, but is preferably 0.01 to 10 μm, more preferably 0.01 to 1 μm.

[0333] <Coating film formation process>

[0334] The coating film formation process is a process of coating a light-absorbing anisotropic film forming composition onto the surface of a specifically oriented film to form a coating film.

[0335] In this process, it is preferable to use the above-mentioned solvent-containing light-absorbing anisotropic film forming composition or a heated melt of the light-absorbing anisotropic film forming composition. This is because it makes it easier to coat the light-absorbing anisotropic film forming composition onto a film with a specific orientation.

[0336] Coating methods for compositions used in the formation of anisotropic light-absorbing films include known methods such as roller coating, gravure printing, spin coating, wire-wound bar coating, extrusion coating, direct gravure coating, reverse gravure coating, die coating, spray coating, and inkjet coating.

[0337] <Orientation Process>

[0338] The alignment process is a process of aligning the liquid crystal components (especially dichroic substances) contained in the coated film. It can be considered that in the alignment process, the dichroic substance is aligned along the liquid crystal compound oriented by the alignment constraint force of a specific alignment film.

[0339] The orientation process may include a drying process. This drying process removes components such as solvents from the coated film. The drying process can be performed by placing the coated film at room temperature for a specified time (e.g., natural drying), or by heating and / or air supply.

[0340] The orientation process preferably includes heat treatment. As a result, the orientation of the dichroic substances contained in the coated film is improved, and the degree of orientation of the obtained light absorption anisotropic film is higher.

[0341] From the perspective of manufacturing applicability, the heat treatment is preferably 10 to 250°C, more preferably 25 to 190°C. Furthermore, the heating time is preferably 1 to 300 seconds, more preferably 1 to 60 seconds.

[0342] The orientation process can include a cooling process performed after the heat treatment. The cooling process involves cooling the heated coated film to approximately room temperature (20–25°C). This further fixes the orientation of the dichroic substances contained in the coated film, and increases the degree of orientation of the light-absorbing anisotropic film. The cooling method is not particularly limited and can be implemented using known methods.

[0343] Through the above processes, this light-absorbing anisotropic film can be obtained.

[0344] <Other Processes>

[0345] The manufacturing method of the light-absorbing anisotropic film may also include a step of curing the light-absorbing anisotropic film after the above-mentioned orientation step (hereinafter also referred to as the "curing step").

[0346] The curing process is carried out, for example, by heating and / or light irradiation (exposure). Preferably, the curing process is carried out by light irradiation.

[0347] As a light source that can be used in curing, various light sources such as infrared, visible light, and ultraviolet light can be cited, with ultraviolet light being preferred. Furthermore, during curing, ultraviolet light can be irradiated while heating is being performed, or ultraviolet light can be irradiated through a filter that transmits only a specific wavelength.

[0348] Furthermore, exposure can be performed under a nitrogen atmosphere. In the case of curing anisotropic films with light absorption via free radical polymerization, the polymerization hindrance caused by oxygen can be reduced, therefore exposure under a nitrogen atmosphere is preferred.

[0349] [Optical film]

[0350] The optical film is a component having at least the light-absorbing anisotropic film involved in this invention. As an optical film, a laminated film formed by stacking an alignment film and a light-absorbing anisotropic film is preferred, and a laminated film formed by sequentially stacking a transparent substrate film, an alignment film and a light-absorbing anisotropic film is more preferred.

[0351] (Transparent substrate film)

[0352] Optical films can have a transparent substrate film.

[0353] Transparent substrate films can be used as substrates for forming anisotropic light absorption films, or as films to protect anisotropic light absorption films. Transparent substrate films can also serve as phase retardation layers.

[0354] As a transparent substrate film, it is not particularly restricted and can use known transparent resin films, transparent resin sheets, and transparent resin plates.

[0355] As a transparent resin film, preferably a cellulose acylated film (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, cyclic olefin polymer film (polymer film using cyclic olefin polymers), polycarbonate polymer film, polystyrene polymer film, or acrylic polymer film.

[0356] As an acrylic polymer film, it is preferred to include an acrylic polymer containing at least one unit selected from lactone ring units, maleic anhydride units and glutaric anhydride units.

[0357] The thickness of the transparent substrate film is preferably 20–100 μm.

[0358] (Orientation film)

[0359] The optical film may have an orientation film, preferably having the specific orientation film described above.

[0360] Regarding the specific method of the orientation film, as has been explained as a particular orientation film.

[0361] The optical film may have layers other than the light-absorbing anisotropic film, the transparent substrate film, and the alignment film, and preferably further includes a resin film comprising 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.

[0362] A resin film containing polyvinyl alcohol or polyimide functions as a primer layer to improve the adhesion between two layers by being formed between two layers selected from the group consisting of anisotropic light-absorbing films, transparent substrate films, and oriented films. Furthermore, the resin film also functions as a barrier layer, as described later.

[0363] Polyvinyl alcohol or polyimide contained in the above-mentioned resin film, for example, polyvinyl alcohol, polyimide or any derivative thereof known as polymer materials for orientation films, are preferred, modified or unmodified polyvinyl alcohol.

[0364] 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.

[0365] The method for forming the resin film is not particularly limited. For example, a method can be described as forming a coated film by coating a resin composition containing polyvinyl alcohol or polyimide onto the surface of a light-absorbing anisotropic layer, and then curing the formed coated film to obtain a resin film. The method for forming the coated film is not particularly limited, and the method described as a coating treatment in the above-described specific orientation film forming process can be cited as an example. Furthermore, as a method for curing the coated film, a method can be described as forming a resin film by removing the solvent contained in the coated film through heating and / or drying.

[0366] [View Control System]

[0367] The viewing angle control system has a polarizer with an absorption axis in the in-plane direction and the aforementioned light absorption anisotropic film or the aforementioned optical film.

[0368] In particular, considering that the anisotropic light absorption film can better exert the effect of viewing angle control when the necessary condition 3 is met, it is preferable to use it in combination with a polarizer for an image display device.

[0369] (Polarizer)

[0370] The polarizer used in the viewing angle control system is not particularly restricted as long as it is a component that has an absorption axis in the in-plane direction and has the function of converting light into specific linearly polarized light, and conventionally known polarizers can be used.

[0371] Examples of polarizers include iodine-based polarizers, dye-based polarizers utilizing dichroic dyes, and polyene-based polarizers. Iodine-based and dye-based polarizers include both coating-type and stretching-type polarizers, both of which are applicable. As a coating-type polarizer, a polarizer that orients dichroic organic pigments by utilizing the orientation of a liquid crystal compound is preferred. As a stretching-type polarizer, a polarizer made by adsorbing iodine or a dichroic dye onto polyvinyl alcohol and then stretching it is preferred.

[0372] Furthermore, as a method for obtaining a polarizer by stretching and dyeing a laminated film in which a polyvinyl alcohol layer is formed on a substrate, examples can be found in Japanese Patent Nos. 5048120, 5143918, 5048120, 4691205, 4751481, and 4751486. ​​It is also preferable to utilize known technologies related to these polarizers.

[0373] From the perspective of easy availability and excellent polarization, a polarizer comprising a polyvinyl alcohol resin (a polymer containing -CH2-CHOH- as repeating units. In particular, a polarizer selected from at least one of the group consisting of polyvinyl alcohol and ethylene-vinyl alcohol copolymers) is preferred.

[0374] The thickness of the polarizer is not particularly limited, but it is preferably 3 to 60 μm, more preferably 5 to 20 μm, and even more preferably 5 to 10 μm.

[0375] (Other components)

[0376] In addition to the components mentioned above, the viewing angle control system may also include other components such as adhesive layers, bonding layers, optical anisotropic films, refractive index adjustment layers, and blocking layers.

[0377] The viewing angle control system can be manufactured by laminating the aforementioned anisotropic light absorption film or optical film and the aforementioned polarizer using an adhesive layer or bonding layer described later. Alternatively, the viewing angle control system can be manufactured by directly laminating the aforementioned alignment film and the aforementioned anisotropic light absorption film onto the aforementioned polarizer.

[0378] (Adhesive layer)

[0379] The adhesive layer is preferably the same transparent and optically isotropic adhesive used in typical image display devices, and pressure-sensitive adhesives are typically used.

[0380] The adhesive layer may include, for example, a matrix material (adhesive), conductive particles, and thermally expandable particles as needed. In addition to the above components, the adhesive layer may also contain additives such as crosslinking agents (e.g., isocyanate crosslinking agents, epoxy crosslinking agents, etc.), tackifiers (e.g., rosin derivative resins, polyterpene resins, petroleum resins, oil-soluble phenolic resins, etc.), plasticizers, fillers, anti-aging agents, surfactants, ultraviolet absorbers, light stabilizers, and antioxidants.

[0381] The thickness of the adhesive layer is, for example, 20 to 500 μm, preferably 20 to 250 μm. If it is 20 μm or more, the adhesive strength and suitability for reprocessing are excellent, and if it is 500 μm or less, the adhesive can be further suppressed from overflowing or seeping from the peripheral end of the image display device.

[0382] As a method for forming the adhesive layer, examples include directly applying a coating liquid containing the above-mentioned components and solvent to a support for the protective component and pressing it by peeling off a backing paper, and applying a coating liquid to a suitable backing paper (such as a release liner) to form a thermally expandable adhesive layer and pressing and transferring it to the support for the protective component.

[0383] In addition, as a protective component, for example, a structure made by adding conductive particles to a heat-peelable adhesive sheet as described in Japanese Patent Application Publication No. 2003-292916 can be used.

[0384] Furthermore, as a protective component, it can also be used on the surface of the adhesive layer in commercially available products such as "REVALPHA" manufactured by NITTO DENKO CORPORATION., where conductive particles are dispersed.

[0385] [Adhesive layer]

[0386] The adhesive layer contains at least an adhesive. The adhesive properties are achieved through drying or reaction after bonding.

[0387] Polyvinyl alcohol adhesives (PVA adhesives) exhibit adhesive properties upon drying, enabling them to bond components together.

[0388] Specific examples of curing adhesives that exhibit adhesion through reaction include reactive energy-curing adhesives such as (meth)acrylate adhesives and cationic polymerization-curing adhesives. Furthermore, (meth)acrylate refers to acrylates and / or methacrylates. As curing components in (meth)acrylate adhesives, for example, compounds having (meth)acryloyl groups and compounds having vinyl groups can be used. Moreover, as cationic polymerization-curing adhesives, compounds having epoxy groups or oxetane groups can also be used. Compounds having epoxy groups are not particularly limited as long as they have at least two epoxy groups within the molecule; various commonly known curing epoxy compounds can be used. Preferred epoxy compounds include, for example, compounds having at least two epoxy groups and at least one aromatic ring within the molecule (aromatic epoxy compounds), and compounds having at least two epoxy groups within the molecule, with at least one of them formed between two adjacent carbon atoms constituting an alicyclic ring (alicyclic epoxy compounds).

[0389] From the viewpoint of resistance to heat deformation, UV-curable adhesives that are cured by UV irradiation are preferred.

[0390] The adhesive layer and its individual layers can possess ultraviolet (UV) absorption capabilities. These layers can be endowed with UV absorption capabilities through known methods such as treatment with UV absorbers including salicylates, benzophenols, benzotriazoles, cyanoacrylates, and nickel complex salts.

[0391] The application of the adhesive layer and bonding layer can be carried out in a suitable manner. For example, one can prepare an adhesive solution with a concentration of about 10 to 40% by weight, which is formed by dissolving or dispersing the base polymer or its composition in a solvent consisting of a single substance or mixture of solvents such as toluene and ethyl acetate, and directly apply it to the film by a casting or coating method, or transfer it by forming an adhesive layer on the separator as described above.

[0392] It is also possible to overlap layers of different compositions or types, and to place adhesive layers and bonding layers on one or both sides of the membrane. Moreover, when adhesive layers are placed on both sides, the composition, type, and thickness of the adhesive layers can be the same or different on the front and back sides of the membrane.

[0393] (Other optically anisotropic films)

[0394] The viewing angle control system can further combine other optical anisotropic films or polarizers with light-absorbing anisotropic films or optical films. By incorporating other optical anisotropic films, the viewing angle control system further improves viewing angle controllability.

[0395] Other optically anisotropic films, like the light-absorbing anisotropic films described above, preferably contain a dichroic material. The types of dichroic materials are as described above.

[0396] Furthermore, other optically anisotropic films, like the light-absorbing anisotropic films described above, preferably contain liquid crystal compounds. The types of liquid crystal compounds are as described above.

[0397] As a preferred embodiment of other optically anisotropic films, a layer in which the dichroic material is oriented along the thickness direction or in-plane direction is preferred. The above-described preferred embodiment can be formed by adding a dichroic material to a liquid crystal compound and oriented it in the desired direction.

[0398] Other methods for forming optically anisotropic films are not particularly limited, and known methods can be cited. Among these, a method using a composition comprising a dichroic substance and a liquid crystal compound is preferred.

[0399] As other optically anisotropic films, resin films that include polymers comprising carbonates, cycloolefins, cellulose acylates, methyl methacrylate, styrene, or maleic anhydride and have optical anisotropy are also preferred.

[0400] (Barrier layer)

[0401] View control systems may have a barrier layer. The barrier layer is also called an oxygen barrier layer and has the function of protecting the light-absorbing anisotropic film or polarizer from the influence of gases such as oxygen, moisture, light, or compounds contained in adjacent layers in the atmosphere.

[0402] Regarding the barrier layer, for example, reference can be made to paragraphs

[0014] to

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

[0042] to

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

[0045] to

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

[0010] to

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

[0021] to

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

[0403] (Refractive index adjustment layer)

[0404] The viewing angle control system can 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.

[0405] The refractive index adjustment layer is configured to be 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. The refractive index adjustment layer is preferably a layer used for so-called refractive index matching.

[0406] [Image display device]

[0407] The aforementioned anisotropic light absorption film, the aforementioned optical film, and the aforementioned viewing angle control system can all be used in any image display device.

[0408] As an image display device, it is not particularly limited. For example, liquid crystal display devices, self-emissive display devices (organic EL (electroluminescence) display devices and micro LED (light emitting diode) display devices) can be cited.

[0409] As an image display device, examples include devices that have a display panel and the aforementioned optical film or viewing angle control system disposed on a main surface of the display panel. Examples of display panels included in an image display device include display panels comprising liquid crystal cells and display panels of self-emissive display devices, on which the optical film or viewing angle control system is disposed.

[0410] A liquid crystal display device, for example, includes a liquid crystal cell and a backlight. Polarizers are provided on two sides of the liquid crystal cell, one on the visual recognition side and the other on the backlight side. The viewing angle control system can be applied to either the visual recognition side or the backlight side of the liquid crystal display device, or it can be applied to both sides. Application to the liquid crystal display device can be achieved by replacing the polarizers on either side or both sides of the liquid crystal display device with the viewing angle control system. That is, the polarizers included in the viewing angle control system can be used as polarizers provided on both sides of the liquid crystal cell.

[0411] When applying a viewing angle control system to an organic EL display device, it is preferable to configure the viewing angle control system on the visual recognition side of the organic EL display device, and the polarizer in the viewing angle control system is configured closer to the organic EL display device than the light absorption anisotropic film. Furthermore, it is preferable to configure a λ / 4 plate between the polarizer and the organic EL display device.

[0412] Furthermore, in the viewing angle control system of the image display device, it is preferable that the light-absorbing anisotropic film is disposed on the visual recognition side relative to the polarizer.

[0413] The liquid crystal unit that constitutes a liquid crystal display device will be described in detail below.

[0414] (Liquid Crystal Unit)

[0415] 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 modes.

[0416] In TN mode liquid crystal cells, the rod-shaped liquid crystal molecules are substantially horizontally oriented when no voltage is applied, and then twisted to an orientation of 60–120°. TN mode liquid crystal cells are most commonly used in color TFT (Thin Film Transistor) liquid crystal display devices, as documented in numerous publications.

[0417] In a VA-mode liquid crystal cell, the rod-shaped liquid crystal molecules are substantially vertically oriented when no voltage is applied. In addition to the narrow definition of a VA-mode liquid crystal cell, which includes (1) a VA-mode liquid crystal cell in which the rod-shaped liquid crystal molecules are substantially vertically oriented when no voltage is applied and substantially horizontally oriented when a voltage is applied (described in Japanese Patent Application Publication No. 2-176625), there are also (2) a liquid crystal cell in which the VA mode is multi-domained in order to expand the field of view (MVA mode) (described in SID97, Digest of tech. Papers 28 (1997) 845), (3) a liquid crystal cell in which the rod-shaped liquid crystal molecules are substantially vertically oriented when no voltage is applied and twisted multi-domain oriented when a voltage is applied (n-ASM mode) (described in the proceedings of the Japan Liquid Crystal Conference 58-59 (1998)) and (4) a SURVIVAL mode liquid crystal cell (published in LCDInternational 98). Furthermore, it can be any of the following: PVA (Patterned Vertical Alignment), Optical Alignment, and PSA (Polymer-Sustained Alignment). Details regarding these modes are described in Japanese Patent Application Publication Nos. 2006-215326 and 2008-538819.

[0418] In an IPS-mode liquid crystal cell, rod-shaped liquid crystal molecules are substantially parallel to the substrate. By applying an electric field parallel to the substrate surface, the liquid crystal molecules respond in a planar manner. In the IPS mode, black is displayed without an applied electric field, and the absorption axes of the upper and lower polarizers are orthogonal to each other. Methods for reducing light leakage and improving the field of view when displaying black in the tilt direction using optical compensation sheets are disclosed in Japanese Patent Application Publication Nos. 10-054982, 11-202323, 9-292522, 11-133408, 11-305217, and 10-307291.

[0419] Example

[0420] The following examples and comparative examples further illustrate the features of the present invention. The materials, amounts, proportions, processing contents, and processing steps shown in the following examples can be appropriately modified without departing from the spirit of the present invention. However, the scope of the present invention should not be interpreted as limited by the specific examples shown below.

[0421] [Example 1]

[0422] The light-absorbing anisotropic film of the present invention is manufactured by a method comprising, in sequence, a specific orientation film forming step, a coating film forming step, a light-absorbing anisotropic film forming composition being coated onto the specific orientation film to form a coating film, and an orientation step, a method for orienting the liquid crystal components contained in the coating film.

[0423] <Fabrication of anisotropic light-absorbing films>

[0424] (Specific orientation film formation process)

[0425] A transparent support (transparent substrate film) was obtained by cutting a cellulose acylated membrane (40 μm thick TAC substrate; manufactured by FUJIFILM Corporation, “TG40”) into dimensions of 40 cm wide and 120 cm long. One surface of the cut support was saponified with an alkali solution, and the following oriented film forming coating solution 1 was applied to the saponified surface using a wire rod, thereby forming a first coated film. The first coated film formed on the support was dried in warm air at 60°C for 60 seconds, and further dried in warm air at 100°C for 120 seconds, thereby forming a resin film. The thickness of the resin film was 0.5 μm.

[0426]

[0427] Modified polyvinyl alcohol (PVA-1)

[0428] [Chemical Formula 7]

[0429]

[0430] The above-mentioned photo-aligned film forming composition F1 was coated onto the obtained resin film and dried at 60°C for 2 minutes to form a second coated film with a thickness of 0.03 μm.

[0431] The coating solution F1 for photo-aligned film formation was prepared by mixing the components shown below, stirring the mixture for 1 hour, and then filtering it using a 0.45 μm filter.

[0432]

[0433] [Chemical Formula 8]

[0434]

[0435] like Figure 5AAs shown, the coating film of the photo-alignment film forming composition formed on the support is divided into two regions on the boundary lines L, which are equidistant from both ends in the long side direction (X-axis direction): a first region 51 on the negative X-axis side and a second region 52 on the positive X-axis side. Furthermore, in both the first region 51 and the second region 52, the length of the short side (width) along the Y-axis is 40 cm, and the length of the long side along the X-axis is 60 cm.

[0436] As a photo-orientation process, polarized ultraviolet light was irradiated onto the first region 51 and the second region 52 of the coated film 50 from different directions.

[0437] First, such as Figure 5B As shown, a mask M is positioned above the second region 52 of the coating film 50 to block light from reaching the second region 52. A UV exposure device is used to irradiate the exposed first region 51 with polarized ultraviolet light (irradiation dose 2000 mJ / cm²) from the positive Z-axis direction (angle θ = 0°). 2 ).

[0438] Next, as Figure 5C As shown, the first region 51 was shielded by moving the mask M above it, and the exposed second region 52 was irradiated with polarized ultraviolet light (irradiation dose 2000 mJ / cm²) from an angle θ = 35° and an angle φ = 0° using an ultraviolet exposure device. 2 ).

[0439] Thus, in region 1 51 and region 2 52, orientation films F with different orientation restraint forces are formed.

[0440] (Coating film formation process)

[0441] The following light-absorbing anisotropic film forming composition P1 is applied to the surface of the orientation film F formed in the above-mentioned specific orientation film forming process using a wire rod, thereby forming a coated film P1.

[0442]

[0443]

[0444] Liquid crystal compound L1

[0445] Liquid crystal compound L2

[0446] [Chemical Formula 9]

[0447]

[0448] Dichroic substance Y1

[0449] [Chemical Formula 10]

[0450]

[0451] Dichroic substance M1

[0452] [Chemical Formula 11]

[0453]

[0454] dichroic substance C1

[0455] [Chemical Formula 12]

[0456]

[0457] Surface Modifier B1

[0458] [Chemical Formula 13]

[0459]

[0460] (Orientation process)

[0461] Next, the coating film P1 formed in the coating film forming process is heated at 120°C for 30 seconds, and then the coating film P1 is cooled to 100°C.

[0462] Subsequently, LED lights (center wavelength 365nm) were used at room temperature (25℃) with an illuminance of 200mW / cm². 2 Under the irradiation conditions, the heated coated film P1 is irradiated for 2 seconds, thereby creating an anisotropic light absorption film P1 on the surface of the alignment film F, and an optical film P1 having a transparent support, an alignment film F and an anisotropic light absorption film P1 in sequence is obtained.

[0463] <Determination of the direction of the central axis of transmittance>

[0464] Samples with dimensions of 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, using a UV-Vis infrared spectrophotometer "JASCO V-670 / ARMN-735" (manufactured by JASCO Corporation), each sample was irradiated with P-polarized light at a wavelength of 550 nm on a sample stage with the film surface horizontal, and the direction of the transmittance central axis of each sample was measured. From this, the angle θ between the direction of the transmittance central axis and the normal to the surface of the light-absorbing anisotropic film P1, and the angle φ relative to the reference direction of the orthogonal projection of the transmittance central axis onto the surface of the light-absorbing anisotropic film P1 were determined. Furthermore, the reference direction of angle φ is taken as the negative direction (long side direction) of the X-axis in the light-absorbing anisotropic film P1.

[0465] The measurement results show that the central axis of transmittance of the optical film P1 sample obtained from region 1 51 is along the normal of the light absorption anisotropic film P1. That is, the angle θ between the central axis of transmittance and the normal of the light absorption anisotropic film P1 is 0°.

[0466] On the other hand, the transmittance central axis of the optical film P1 sample obtained from region 52 is tilted at an angle of 34° relative to the normal of the light absorption anisotropic film P1. In other words, the angle θ between the transmittance central axis of the optical film P1 in region 52 and the normal is 34°. Moreover, in the optical film P1 sample obtained from region 52, the orthographic projection of the transmittance central axis relative to the surface of the light absorption anisotropic film extends in a direction with an angle φ = 0°.

[0467] Therefore, as shown in FIG1, regarding the light absorption anisotropic film P1 obtained in Example 1, it can be confirmed that a first region 51 with an angle θ of 0° representing the direction of the transmittance central axis and a second region 52 with an angle θ and an angle φ of 34° and 0° representing the direction of the transmittance central axis are arranged along the X-axis direction.

[0468] <The Making of an Image Display Device>

[0469] A coating film is formed by continuously applying the following blocking layer forming composition G onto the surface of the light absorption anisotropic film P1 side of the optical film P1 obtained above using a wire rod.

[0470] Next, the coating was dried by blowing warm air at 60°C for 60 seconds and then blowing warm air at 100°C for 120 seconds to form a barrier layer G, thus obtaining an optical film with a barrier layer. The thickness of the barrier layer G is 1.0 μm.

[0471]

[0472] The image display device (“iPad 2 WiFi Model 16GB”, manufactured by Apple Inc.) was disassembled, and the image display panel (14.8 cm wide and 19.7 cm long) was disassembled. The liquid crystal unit was removed, and the visual recognition side polarizer was peeled off from the liquid crystal unit. Next, a glass plate of the same size as the aforementioned optical film with a barrier layer (40 cm wide and 120 cm long) was prepared, and the two aforementioned image display panels were respectively mounted in designated positions on the glass plate. Then, the aforementioned optical film with a barrier layer was adhered to the surface of the glass plate opposite to the image display panel on which the image display panel was mounted, with the barrier layer G facing the glass plate, using the adhesive sheet described below, thus creating the image display device.

[0473] (Preparation of adhesive sheet)

[0474] Acrylate polymers were prepared in the following order.

[0475] 95 parts by mass of butyl acrylate and 5 parts by mass of acrylic acid were mixed in a reaction vessel equipped with a cooling pipe, a nitrogen inlet pipe, a thermometer, and a stirring device. The 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.

[0476] In addition to the obtained acrylate polymer A1 (100 parts by mass), a 75% by mass ethyl acetate solution of toluene diisocyanate trimethylolpropane adduct, with 3 isocyanate groups per molecule, manufactured by Nippon Polyurethane Industry Co., Ltd. (1.0 part by mass) and a 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 obtained mixture to make the total solids concentration of the mixture 10% by mass, thus preparing an adhesive forming composition. The composition was coated onto a release membrane that had been surface-treated with a silicone stripper using a die coater, and the resulting film was dried at 90°C for 1 minute, thereby obtaining an acrylate adhesive sheet. The obtained adhesive sheet had a film thickness of 25 μm and a storage modulus of elasticity of 0.1 MPa.

[0477] exist Figure 9 The structure of the image display device manufactured in Embodiment 1 is shown.

[0478] Figure 9 This is a side view of the rectangular image display device 100 as viewed from its in-plane width direction (the negative direction of the Y-axis). For example... Figure 9 As shown, the image display device 100 includes an optical film 110 with a blocking layer, an adhesive sheet 112, a glass plate 120, a first panel 131, and a second panel 132. In the light absorption anisotropic film (not shown) of the optical film 110 with the blocking layer, the first region with a transmittance central axis angle θ of 0° is disposed on the negative X-axis side, and the second region with a transmittance central axis angle θ of 34° and a transmittance central axis positive projection angle φ of 0° is disposed on the positive X-axis side.

[0479] Furthermore, the first panel 131 is located at a position 20 cm away from the end of the optical film 110 with the blocking layer on the negative X-axis direction (hereinafter also referred to as "position I"), and the second panel 132 is located at a position 100 cm away from the aforementioned end in the X-axis direction (hereinafter also referred to as "position III").

[0480] 〔evaluate〕

[0481] <Visual recognition>

[0482] The image display device 100 manufactured in Embodiment 1 was observed from a viewing position 140 cm away from the first panel 131 along the stacking direction (positive direction of the Z-axis). Based on the following evaluation criteria, the visual recognizability (clarity) of the displayed images was evaluated for the first panel 131 at position I and the second panel 132 at position III, respectively.

[0483] (Visual recognition assessment criteria)

[0484] “A”: The displayed image can be clearly visually recognized.

[0485] “B”: Visually recognizable displayed image.

[0486] “C”: No visually recognized displayed image.

[0487] <Reflected glare>

[0488] An optical film 110 with a blocking layer is tilted at a 30° elevation angle to the horizontal when viewed from the negative Y-axis side towards the positive Y-axis side, and is positioned vertically above the image display device 100. Next, a glass plate R (40 cm wide and 120 cm long) for evaluating reflective glare is placed above the image display device 100, with the long side of the glass plate R aligned horizontally. The glass plate R is positioned such that the plane containing the normal to the display surface of the image display device 100 (the surface of the optical film 110 with the blocking layer) and the normal to the glass plate R includes the vertical direction, and the angle between the normal to the image display device 100 and the normal to the glass plate R is 85°. Furthermore, the glass plate R is positioned at a distance of 50 cm between the center of the surface of the glass plate R opposite to the image display device 100 and the center of the display surface of the image display device 100.

[0489] Using the image display device 100 and glass plate R as described above, the reflected glare (reflected image) of the displayed image on the surface of the glass plate R was observed and evaluated. In the reflected glare evaluation, observations were made from an observation position corresponding to position III of the second panel 132 of the image display device 100. More specifically, an observation position was set on a plane (YZ plane) containing the normal to the display surface of the image display device 100 and the normal to the glass plate R. The distance from the intersection point α of the center line equidistant from the long side of the surface of the glass plate R and the YZ plane to the observation position was 140 cm, and the angle between the line connecting the observation position and the intersection point α and the normal to the glass plate R was 20°. From this observation position, the displayed image on the first panel 131 of the image display device 100 at position I and the displayed image on the second panel 132 at position III, reflected by the glass plate R, were observed. Based on the observation results, the reflected glare of the displayed image was evaluated according to the following evaluation criteria.

[0490] (Reflective Glare Evaluation Criteria)

[0491] “A”: The reflected image can be faintly recognized by visual means.

[0492] “B”: Visually recognizable reflected image.

[0493] “C”: Reflected images can be strongly visually recognized.

[0494] [Example 2]

[0495] In the specific orientation film formation process of Example 1, the coating film of the photo-alignment film forming composition formed on the support is divided into 3 regions with equal lengths along its long side. As a photo-alignment treatment, each region is irradiated with polarized ultraviolet light from different directions. Otherwise, an optical film with a blocking layer is produced according to the method described in Example 1.

[0496] More specifically, in the specific alignment film formation process, the coating film of the photoalignment film forming composition formed on the support is divided into three regions, with their long sides having equal lengths. In these three regions, the length in the Y-axis direction is 40 cm, and the length in the X-axis direction is 40 cm.

[0497] Next, as shown in Figure 6, as a photo-alignment process, polarized ultraviolet light (irradiation dose 2000 mJ / cm²) was used to irradiate the first region 61, the second region 62, and the third region 63 of the coated film 60 from different directions using an ultraviolet exposure device. 2 ).

[0498] First, such as Figure 6AAs shown, mask M is used to block light from regions 62 and 63, and polarized ultraviolet light is irradiated onto the exposed region 61 from the positive Z-axis direction (angle θ = 0°). Then, as... Figure 6B As shown, region 61 and region 63 are shielded by mask M, and polarized ultraviolet light is irradiated onto the exposed region 62 from an angle θ = 15° and an angle φ = 0°. Then, as... Figure 6C As shown, the first region 61 and the second region 62 are shielded by a mask M, and the exposed third region 63 is irradiated with polarized ultraviolet light from an angle θ = 35° and an angle φ = 0°.

[0499] Thus, in regions 1 (61), 2 (62), and 3 (63), orientation films F with different orientation restraint forces are formed.

[0500] In addition to using the alignment film F formed in the above-described specific alignment film forming process, an anisotropic light absorption film P2 is formed on the surface of the alignment film F according to the method described in Example 1, thereby obtaining an optical film P2 having a transparent support, an alignment film F and an anisotropic light absorption film P2 in sequence.

[0501] According to the method described in Example 1, "Determination of the Direction of the Transmittance Central Axis", the angle θ between the direction of the transmittance central axis and the normal to the surface of the light absorption anisotropic film P2, and the angle φ relative to the reference direction of the orthographic projection of the transmittance central axis onto the surface of the light absorption anisotropic film P2 were determined from the sample cut from the region corresponding to the first region, the second region, and the third region of the obtained optical film P2.

[0502] The measurement results are shown in Table 1 below.

[0503] In addition to using the optical film P2 obtained above, an image display device was manufactured according to the method described in Example 1, "Manufacturing of an Image Display Device". In Example 2, three image display panels were mounted at predetermined positions on a glass plate.

[0504] exist Figure 10 The structure of the image display device manufactured in Embodiment 2 is shown.

[0505] Figure 10 This is a side view of the rectangular image display device 200 as viewed from its in-plane width direction (the negative direction of the Y-axis). For example... Figure 10As shown, the image display device 200 includes an optical film 210 with a blocking layer, an adhesive sheet 112, a glass plate 120, a first panel 131, a second panel 132, and a third panel 133. In the light-absorbing anisotropic film (not shown) of the optical film 210 with the blocking layer, from the negative X-axis direction side, there are sequentially arranged the following regions: a first region where the angle θ of the transmittance central axis is 0°; a second region where the angle θ of the transmittance central axis is 15° and the angle φ of the orthogonal projection of the transmittance central axis is 0°; and a third region where the angle θ of the transmittance central axis is 35° and the angle φ of the orthogonal projection of the transmittance central axis is 0°.

[0506] Furthermore, the first panel 131 is disposed at position I in the image display device of Embodiment 1, the second panel 132 is disposed at a position 60 cm away from the end of the optical film 210 with the blocking layer on the negative X-axis direction in the X-axis direction of the center of the second panel 132 (hereinafter also referred to as "position II"), and the third panel 133 is disposed at position III in the image display device of Embodiment 1.

[0507] 〔evaluate〕

[0508] <Visual recognition>

[0509] The image display device 200 manufactured in Embodiment 2 was observed from a viewing position I140cm away from the first panel 131 along the stacking direction (positive direction of the Z axis).

[0510] Based on the observations obtained, the visual recognizability (clarity) of the displayed images was evaluated for 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, respectively, based on the same evaluation criteria as in Example 1.

[0511] <Reflected glare>

[0512] Following the method for evaluating reflected glare in Example 1, the reflected image of the image displayed on the image display device 200 projected onto the glass plate R was observed, and the reflected glare of the displayed image on the glass plate R was evaluated. Specifically, based on the method described in Example 1, the image display device 200 and the glass plate R were set up, and the reflected glare in the glass plate R was observed from the same observation position as in Example 1 (including the position on the YZ plane at position III). Furthermore, in Example 2, the reflected glare of the reflected images was evaluated for the displayed image on the first panel 131 at position I, the displayed image on the second panel 132 at position II, and the displayed image on the third panel 133 at position III, respectively.

[0513] [Example 3]

[0514] In the specific orientation film formation process of Example 2, the irradiation direction of polarized ultraviolet light irradiating the first region 61, the second region 62 and the third region 63 of the coating film 60 is changed as follows. Otherwise, an optical film with a blocking layer is produced according to the method described in Example 2.

[0515] More specifically, polarized ultraviolet light was irradiated onto region 61 from an angle θ = 30° and an angle φ = 180°, polarized ultraviolet light was irradiated onto region 62 from the positive direction of the Z-axis (the direction of angle θ = 0°), and polarized ultraviolet light was irradiated onto region 63 from an angle θ = 30° and an angle φ = 0°.

[0516] Thus, in regions 1, 61, 2, 62 and 3, oriented films F with different orientation restraint forces are formed, and the optical film with a blocking layer of Example 3 is produced.

[0517] An image display device was fabricated using the optical film with a blocking layer, following the method described in Example 2.

[0518] 〔evaluate〕

[0519] <Visual recognition>

[0520] The image display device manufactured in Example 3 was observed from a viewing position 100 cm away from the position II where the second panel is located along the stacking direction (positive direction of the Z-axis).

[0521] Based on the observations obtained, the visual recognizability (clarity) of the displayed images was evaluated for the first panel located at position I, the second panel located at position II, and the second panel located at position III, respectively, based on the same evaluation criteria as in Example 1.

[0522] <Reflected glare>

[0523] According to the evaluation method for reflected glare in Example 2, the reflected image of the image displayed by the image display device projected onto the glass plate R was observed, and the reflected glare of the image displayed on the glass plate R was evaluated.

[0524] [Example 4]

[0525] In Example 1, the photo-alignment process in the specific alignment film formation process was changed as follows. Otherwise, an optical film with a blocking layer was fabricated according to the method described in Example 1.

[0526] That is, a mold with a width of 40cm, a length of 120cm, and a curvature of 0.0131 [1 / cm] is made, and a substrate for forming a coating film of an oriented film-forming composition is disposed along the surface of the mold. Next, as... Figure 7As shown, the normal direction relative to the contact surface of the coating film is located at a position 60 cm away from both ends of the long side of the coating film. Figure 7 The surface of the coated film was irradiated with polarized ultraviolet light (irradiation dose 2000 mJ / cm²) along the positive Z-axis (as shown). 2 After irradiation, the obtained alignment film was peeled off from the mold to form an alignment film F in which the direction (angle θ) of the alignment restraint force continuously changes along the long side. The optical film with a barrier layer of Example 4 was made using the obtained alignment film F.

[0527] An image display device was fabricated using the optical film with a blocking layer, following the method described in Example 2.

[0528] 〔evaluate〕

[0529] The visual recognition and reflected glare of the manufactured image display device were evaluated according to the evaluation method described in Example 3.

[0530] [Comparative Example 1]

[0531] The process of irradiating the entire surface of the coating film of the optical alignment film forming composition formed on the support with polarized ultraviolet light from the positive direction of the Z-axis (the direction of angle θ = 0°) to form an alignment film with the direction of the alignment restraint force parallel to the entire surface was carried out instead of the specific alignment film forming process of Example 1. Otherwise, the optical film with a blocking layer of Comparative Example 1 was formed according to the method described in Example 1.

[0532] An image display device was fabricated using the optical film with a blocking layer, following the method described in Example 2.

[0533] The visual recognition and reflected glare of the manufactured image display device were evaluated according to the evaluation method described in Example 2.

[0534] Table 1 records the characteristics and evaluation results of the light-absorbing anisotropic films prepared in each embodiment and comparative example.

[0535] In Table 1, the column "Anisotropic Light Absorption Film" indicates the direction of the transmittance central axis in the in-plane direction of the anisotropic light absorption film fabricated in each embodiment and comparative example. Furthermore, the column "Angle θ" indicates the angle between the transmittance central axis and the normal to the surface of the anisotropic light absorption film, and the column "Angle φ" indicates the angle between the orthographic projection of the transmittance central axis onto the surface of the anisotropic light absorption film and the long side direction of the anisotropic light absorption film.

[0536] In Table 1, "continuous variation" in Example 4 refers to the angle θ, representing the direction of the transmittance central axis, continuously varying along the long side of the light absorption 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 absorption anisotropic film continuously decreases from both ends of the X-axis direction towards the center; in positions I and III, angle θ is 30°, and in position II, angle θ is 0°. Moreover, the "angle φ" column in Example 4 indicates that, except for position II where angle θ is 0°, angle φ in the light absorption anisotropic film is 0° or 180°.

[0537] In Table 1, “I”, “II” and “III” in the “Visual Recognition” and “Reflective Glare” columns indicate the location of the image display panel for each evaluation.

[0538] [Table 1]

[0539]

[0540] As shown in Table 1, it can be confirmed that the light absorption anisotropic films of Examples 1 to 4 involved in the present invention have excellent visual recognition of the displayed images at any position in positions I to III, and the present invention has excellent effects.

[0541] [Example 5]

[0542] A transparent support (transparent substrate film) was obtained by cutting a cellulose acylated membrane (40 μm thick TAC substrate; manufactured by FUJIFILM Corporation, “TG40”) into dimensions of 30 cm wide and 60 cm long. One surface of the cut support was saponified with an alkali solution, and the above-mentioned alignment film forming coating solution 1 was applied to the saponified surface using a wire rod, thereby forming a first coated film. The first coated film formed on the support was dried in warm air at 60°C for 60 seconds, and further dried in warm air at 100°C for 120 seconds, thereby forming a resin film. The thickness of the resin film was 0.5 μm.

[0543] The above-mentioned photo-alignment film forming composition F1 was coated onto the obtained resin film and dried at 60°C for 2 minutes to form a second coated film with a thickness of 0.03 μm.

[0544] The coating film of the photo-alignment film forming composition formed on the support is divided into two regions on the positive Y-axis side and the negative Y-axis side along the boundary lines at equal intervals from both ends in the long side direction (Y-axis direction). Furthermore, in both the first and second regions, the length in the Y-axis direction is 30 cm, and the length in the X-axis direction is 30 cm.

[0545] Next, as a photo-alignment process, polarized ultraviolet light (irradiation dose 2000 mJ / cm²) was used to irradiate the first and second regions of the coated film from different directions using an ultraviolet exposure device. 2 ).

[0546] First, such as Figure 8A As shown, the second region 82 of the coating film 80 is shielded from light using a mask M, and the exposed first region 81 is irradiated with polarized ultraviolet light from a direction with an angle θ = 30° and an angle φ = 0°.

[0547] Next, as Figure 8B As shown, the first region 81 of the coating film 80 is shielded from light using a mask M, and the exposed second region 82 is irradiated with polarized ultraviolet light from an angle θ = 30° and an angle φ = 50°.

[0548] Thus, in region 1 81 and region 2 82, orientation films F with different orientation restraint forces are formed.

[0549] In addition to using the alignment film F formed in the above-described specific alignment film forming process, an anisotropic light absorption film P5 is formed on the surface of the alignment film F according to the method described in Example 1, thereby obtaining an optical film P5 having a transparent support, an alignment film F and an anisotropic light absorption film P5 in sequence.

[0550] Following the method described in Example 1, "Determination of the Direction of the Transmittance Central Axis," the angle θ between the direction of the transmittance central axis and the normal to the surface of the light absorption anisotropic film P1, and the angle φ relative to the reference direction of the orthogonal projection of the transmittance central axis onto the surface of the light absorption anisotropic film P1 were determined from samples cut from the regions corresponding to the first and second regions of the obtained optical film P5. Furthermore, the reference direction of angle φ is taken as the negative direction (width direction) of the X-axis in the light absorption anisotropic film P5.

[0551] The measurement results show that the transmittance central axis of the optical film P5 sample obtained from region 1 is tilted at an angle of 31° relative to the normal of the light absorption anisotropic film P5. That is, the angle θ between the transmittance central axis of the optical film P5 in region 1 and the normal is 31°. Moreover, in the optical film P5 sample obtained from region 1, the orthographic projection of the transmittance central axis relative to the surface of the light absorption anisotropic film extends in the direction of angle φ = 0°.

[0552] Furthermore, the angle θ between the transmittance central axis and the normal of the optical film P5 sample obtained from the second region is 31°. In the optical film P5 sample obtained from the second region, the orthographic projection of the transmittance central axis relative to the surface of the light absorption anisotropic film extends in the direction of angle φ = 49°.

[0553] Therefore, as shown in FIG4, regarding the light absorption anisotropic film P5 obtained in Example 5, it can be confirmed that a first region 81 with an angle θ and an angle φ of 31° and 0° respectively representing the direction of the transmittance central axis and a second region 82 with an angle θ and an angle φ of 31° and 49° respectively representing the direction of the transmittance central axis are arranged along the Y-axis direction.

[0554] <The Making of an Image Display Device>

[0555] A coating film is formed by continuously applying the above-mentioned blocking layer forming composition G onto the surface of the light absorption anisotropic film P5 side of the optical film P5 obtained above using a wire rod.

[0556] Next, the coating was dried by blowing warm air at 60°C for 60 seconds and then blowing warm air at 100°C for 120 seconds to form a barrier layer G, thus obtaining an optical film with a barrier layer. The thickness of the barrier layer G is 1.0 μm.

[0557] The image display device (“iPad 2 WiFi Model 16GB”, manufactured by Apple Inc.) was disassembled, and the image display panel (14.8 cm wide and 19.7 cm long) was disassembled. The liquid crystal unit was removed, and the visual recognition side polarizer was peeled off from the liquid crystal unit. Next, a glass plate of the same size as the aforementioned optical film with a barrier layer (30 cm wide and 60 cm long) was prepared, and the two aforementioned image display panels were respectively mounted in designated positions on the glass plate. Then, the aforementioned optical film with a barrier layer was adhered to the surface of the glass plate opposite to the image display panel with the barrier layer G facing the glass plate using the aforementioned adhesive sheet, thus creating the image display device.

[0558] The manufactured image display device includes an optical film with a blocking layer, an adhesive sheet, and a glass plate, and further includes a first panel and a second panel as image display panels. In the light absorption anisotropic film (not shown) of the optical film with the blocking layer, a first region with a transmittance central axis angle θ of 31° and a transmittance central axis orthogonal projection angle φ of 0° and a second region with a transmittance central axis angle θ of 31° and a transmittance central axis orthogonal projection angle φ of 49° are arranged in the long side direction.

[0559] In the manufactured image display device, the first panel is located at a position 10 cm away from the end of the first region side of the optical film with the blocking layer in the long side direction (hereinafter also referred to as "position IV"), and the second panel is located at a position 50 cm away from the end of the first region side of the optical film with the blocking layer in the long side direction (hereinafter also referred to as "position VI").

[0560] 〔evaluate〕

[0561] <Visual recognition>

[0562] Figure 11A and Figure 11B This is an accompanying drawing illustrating the evaluation method of the image display device manufactured in Embodiment 5, and is a schematic diagram showing the position O of the observer when evaluating the image display device 300.

[0563] The image display device 300 is configured such that the long side of the image display device 300 is along the vertical direction (Y-axis direction), and the first region is arranged on the lower side and the second region is arranged on the upper side.

[0564] Figure 11A This is the front view as viewed from the normal direction of the surface of the image display device 300 configured as described above. Figure 11B This is a top view of the image display device 300 when viewed from a vertical position.

[0565] exist Figure 11A Positions IV, V (refer to Embodiment 6), and VI in the image display device 300 are shown.

[0566] from Figure 11A The height Y1 of the lower end of the image display device 300 to the observer's position O is 50cm, which is the same height as position VI.

[0567] Moreover, such as Figure 11A and Figure 11B As shown, the distance X1 from the center of the image display device 300 in the short side direction (X-axis direction) to the observer's position O in the X-axis direction is 45 cm. Furthermore, from the observer's perspective, the image display device 300 is located on the positive X-axis side (right side of the paper).

[0568] Moreover, such as Figure 11B As shown, the distance Z1 from the observer's position O to the plane (XY plane) containing the surface of the image display device 300 is 70 cm.

[0569] Based on the observer's position O, the visual recognizability (clarity) of the displayed image is evaluated for the first panel located at position IV and the second panel located at position VI, using the same evaluation criteria as in Example 1.

[0570] [Example 6]

[0571] In the specific alignment film formation process of Example 6, the coating film of the photoalignment film forming composition formed on the support is divided into 3 regions with equal lengths along its long side. As a photoalignment treatment, each region is irradiated with polarized ultraviolet light from different directions. Otherwise, the alignment film is prepared according to the method described in Example 5.

[0572] More specifically, in the specific alignment film formation process, the coating film of the photoalignment film forming composition formed on the support is divided into three regions: a first region, a second region, and a third region, all with equal lengths along their long sides. In each of these three regions, the length of the coating film along its long side is 20 cm, and the length of the coating film along its short side is 30 cm.

[0573] Next, as a photo-alignment process, polarized ultraviolet light (irradiation dose 2000 mJ / cm²) was used to irradiate regions 1, 2, and 3 of the coated film from different directions using an ultraviolet exposure device. 2 ).

[0574] First, regions 2 and 3 are shielded using mask M, and polarized ultraviolet light is irradiated onto the exposed region 1 from an angle θ = 30° and an angle φ = 0°. Next, regions 1 and 3 are shielded using mask M, and polarized ultraviolet light is irradiated onto the exposed region 2 from an angle θ = 30° and an angle φ = 30°. Next, regions 1 and 2 are shielded using mask M, and polarized ultraviolet light is irradiated onto the exposed region 3 from an angle θ = 30° and an angle φ = 50°. Furthermore, when viewing the coating film of the photo-alignment film forming composition formed on the support from the front, the angle φ (φ = 0°) representing the irradiation direction of the polarized ultraviolet light is taken from a direction that is rotated 90° counterclockwise relative to the direction in which regions 1, 2, and 3 are arranged in that order.

[0575] Thus, in each of the first, second, and third regions, an orientation film F with different orientation restraint forces is formed.

[0576] In addition to using the alignment film F formed in the above-described specific alignment film forming process, an anisotropic light absorption film P6 is formed on the surface of the alignment film F according to the method described in Example 5, thereby obtaining an optical film P6 having a transparent support, an alignment film F and an anisotropic light absorption film P6 in sequence.

[0577] 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 absorption anisotropic film P6, and the angle φ relative to the reference direction of the orthographic projection of the transmittance central axis onto the surface of the light absorption anisotropic film P6 were determined from the sample cut from the region corresponding to the first region, the second region and the third region.

[0578] The measurement results are shown in Table 2 below.

[0579] In addition to using the optical film P6 obtained above, an image display device was manufactured according to the method described in Example 5, "Manufacturing of an Image Display Device". In Example 6, three image display panels were mounted at predetermined positions on a glass plate.

[0580] In the image display device manufactured in Example 6, the first panel is disposed at position IV in the image display device, the second panel is disposed in the image display device at a position 30 cm away from the end of the first region side of the optical film with the blocking layer in the long side direction of the center of the short side direction of the first panel (hereinafter also referred to as "position IV"), and the third panel is disposed at position VI in the image display device.

[0581] 〔evaluate〕

[0582] <Visual recognition>

[0583] Regarding the obtained image display device, according to the method described in Example 5, the visual recognizability (clarity) of the displayed image was evaluated for each of the first panel located at position IV, the second panel located at position V, and the third panel located at position VI, based on the same evaluation criteria as in Example 1, according to the observer's position O.

[0584] [Comparative Example 2]

[0585] The process of irradiating the entire surface of the coating film of the optical alignment film forming composition formed on the support with polarized ultraviolet light from an angle θ = 30° and an angle φ = 0° to form an alignment film with the direction of the alignment restraint force parallel to the entire surface was carried out instead of the specific alignment film forming process of Example 5. Otherwise, the optical film with a blocking layer of Comparative Example 2 was formed according to the method described in Example 5.

[0586] Using the optical film with the barrier layer that was made, an image display device was made according to the method described in Example 5, and the visual recognizability of the made image display device was evaluated according to the evaluation method described in Example 5.

[0587] Table 2 records the characteristics and evaluation results of the light-absorbing anisotropic films prepared in each embodiment and Comparative Example 2.

[0588] In Table 2, the "Light Absorption Anisotropic Film" column indicates the direction of the transmittance central axis in the in-plane direction of the light absorption anisotropic film fabricated in each embodiment and comparative example. Furthermore, the "Angle θ" column indicates the angle between the transmittance central axis and the normal to the surface of the light absorption anisotropic film, and the "Angle φ" column indicates the angle between the orthographic projection of the transmittance central axis onto the surface of the light absorption anisotropic film and the short side direction of the light absorption anisotropic film.

[0589] In Table 1, “IV”, “V” and “VI” in the “Visual Discrimination” column indicate the location of the image display panel for each evaluation.

[0590] [Table 2]

[0591]

[0592] As shown in Table 2, it can be confirmed that the light absorption anisotropic film involved in this invention has excellent visual recognition of the displayed image at any position from IV to VI, and the effect of this invention is excellent.

[0593] Symbol Explanation

[0594] 1- Dichroic material; 10, 20, 30, 40- Anisotropic light absorption film; 11, 21, 41, 51, 61, 81- Region 1; 12, 22, 42, 52, 62, 82- Region 2; 23, 63- Region 3; 30a- Central part; 30b- End; 50, 60, 70, 80- Orientation film; 100, 200, 300- Image display device; 110, 210- Optical film with blocking layer; 112- Adhesive sheet; 120- Glass plate; 131- First panel (image display panel); 132- Second panel (image display panel); L- Boundary line; M- Mask.

Claims

1. A light-absorbing anisotropic film, comprising a dichroic material and a liquid crystal compound, wherein, The light-absorbing anisotropic film has multiple regions with different directions of the transmittance central axis in the in-plane direction. In all of the aforementioned regions, the angle θ formed by the central axis of transmittance and the normal direction of the surface of the anisotropic light absorption film is within the range of 0 to 70°. The light-absorbing anisotropic film satisfies any one of the necessary conditions 1 to 3. Necessary condition 1: The angle θ in at least one of the plurality of regions is 0°. Necessary condition 2: In at least two of the plurality of regions, the orthogonal projection directions 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. Necessary condition 3: In at least two of the plurality of regions, the angle θ is the same, and in the at least two regions, the orthogonal projection directions of the transmittance center 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, wherein, The light-absorbing anisotropic film satisfies either necessary condition 1 or necessary condition 2. As the plane moves along the in-plane direction where the plurality of regions are configured, the angle θ increases in stages or continuously, or decreases in stages or continuously.

3. The light-absorbing anisotropic film according to claim 1, wherein, The light-absorbing anisotropic film satisfies either necessary condition 1 or necessary condition 2. As the light-absorbing anisotropic film moves along the in-plane direction where the plurality of regions are configured, the angle θ in the film continuously increases or continuously decreases.

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

5. The light-absorbing anisotropic film according to claim 1, wherein, The light-absorbing anisotropic film satisfies the necessary condition 3. As the plane moves along the in-plane direction where the at least two regions are configured, from the first region included in the at least two regions toward other regions besides the first region, the angle between the orthogonal projection direction of the transmittance central axis and the in-plane direction... It increases in stages or continuously, or decreases in stages or continuously.

6. The light-absorbing anisotropic film according to claim 1, wherein, The light-absorbing anisotropic film satisfies the necessary condition 3. As the plane moves along the in-plane direction where the at least two regions are configured, from the first region included in the at least two regions toward other regions besides the first region, the angle between the orthogonal projection direction of the transmittance central axis and the in-plane direction... It increases continuously, or decreases continuously.

7. The light-absorbing anisotropic film according to claim 5, wherein, As the plane moves along the in-plane direction where the at least two regions are configured, from the first region included in the at least two regions toward other regions besides the first region, the angle between the orthogonal projection direction of the transmittance central axis and the in-plane direction... It increases continuously, or decreases continuously.

8. An optical film having a light-absorbing anisotropic layer and an alignment film as described in any one of claims 1 to 7.

9. The optical film according to claim 8, wherein, It further comprises a resin film containing polyvinyl alcohol or polyimide.

10. An image display device comprising a display panel and an optical film of claim 8 disposed on a main surface of the display panel.

Images