Optical film

Abstract

The present invention addresses the problem of providing an optical film having excellent adhesion between a light absorption anisotropic layer and a protective layer without performing a corona treatment on the surface of the light absorption anisotropic layer. The optical film according to the present invention comprises: a light absorption anisotropic layer containing a surfactant, a dichroic substance, and a liquid crystal compound; and a protective layer adjacent to the light absorption anisotropic layer, wherein the angle θ between the transmittance central axis of the light absorption anisotropic layer and the direction normal to the surface of the light absorption anisotropic layer is 0-45°, the surfactant has both a hydrophobic portion having a ClogP value of 3.5 or more and a hydrophilic portion having a ClogP value of 1.0 or less and having a molecular weight of less than 1000, and the peak intensities of ion fragments derived from the hydrophobic portion, detected at surface X, interface Y, and the center position Z in the film thickness direction between the surface X and the interface Y satisfy a predetermined relationship.

Description

Optical Film

[0001] The present invention relates to an optical film.

[0002] A technique for preventing viewing of an image display device and controlling the viewing angle by using a light-absorbing anisotropic layer having an absorption axis in the thickness direction is known. For example, Patent Document 1 describes "an optical film having a light-absorbing anisotropic layer containing a liquid crystal compound and a dichroic substance, wherein the angle θ between the transmittance central axis of the light-absorbing anisotropic layer and the normal direction to the surface of the light-absorbing anisotropic layer is 0° or more and 45° or less, and the haze value of the optical film is more than 1% and 20% or less" ([Claim 1]), and also describes a specific embodiment in which a protective layer is provided on the light-absorbing anisotropic layer (

[0238] , etc.).

[0003] International Publication No. 2022 / 270466

[0004] The present inventors have studied the optical film having an optically absorbing anisotropic layer and a protective layer adjacent to each other, as described in Patent Document 1, and have found that, depending on the compositions of the optically absorbing anisotropic layer-forming composition and the protective layer-forming composition, when a protective layer is formed on the optically absorbing anisotropic layer, cissing may occur in the protective layer-forming composition (coating liquid), resulting in poor adhesion between the optically absorbing anisotropic layer and the protective layer. The present inventors have decided not to consider a method of improving the adhesion between the optically absorbing anisotropic layer and the protective layer by subjecting the surface of the optically absorbing anisotropic layer to corona treatment, from the standpoint of production costs.

[0005] Therefore, an object of the present invention is to provide an optical film that has excellent adhesion between an optically absorptive anisotropic layer and a protective layer without subjecting the surface of the optically absorptive anisotropic layer to corona treatment.

[0006] As a result of extensive research to achieve the above object, the present inventors have found that by providing a surfactant at both the surface X of the protective layer opposite the optically absorbing anisotropic layer and the interface Y between the optically absorbing anisotropic layer and the protective layer with both a hydrophobic moiety with a ClogP value of 3.5 or more and a hydrophilic moiety with a ClogP value of 1.0 or less and a molecular weight of less than 1,000, and by satisfying a predetermined relationship between the peak intensities of ion fragments derived from the hydrophobic moiety at the surface X, the interface Y, and the central position Z in the film thickness direction of these, the optically absorbing anisotropic layer can have good adhesion to the protective layer even when an optical film is produced without subjecting the surface of the optically absorbing anisotropic layer to corona treatment.

[0007] [1] A light-absorbing anisotropic layer containing a surfactant, a dichroic material, and a liquid crystal compound, and a protective layer provided adjacent to the light-absorbing anisotropic layer, wherein the angle θ between the transmittance central axis of the light-absorbing anisotropic layer and the normal direction to the surface of the light-absorbing anisotropic layer is 0° or more and 45° or less, the surfactant has both a hydrophobic moiety having a ClogP value of 3.5 or more and a hydrophilic moiety having a ClogP value of 1.0 or less and a molecular weight of less than 1,000, and both the hydrophobic moiety and the hydrophilic moiety are present on a surface X of the protective layer opposite to the light-absorbing anisotropic layer, and on an interface Y between the light-absorbing anisotropic layer and the protective layer, An optical film that satisfies all of the following formulas (1) to (3) when the peak intensities of ion fragments derived from a hydrophobic portion detected at the surface X, the interface Y, and a central position Z in the film thickness direction between the interfaces X and Y are Ix, Iy, and Iz, respectively, when secondary ion intensity is measured by time-of-flight secondary ion mass spectrometry while irradiating an ion beam from the surface X toward the interface Y. Formula (1) Ix / Iz ≧ 2 Formula (2) Iy / Iz ≧ 2 Formula (3) 0.05 ≦ Ix / Iy ≦ 1.5 [2] The optical film according to [1], wherein the hydrophobic portion is a repeating unit having a siloxane bond in a side chain. [3] The optical film according to [1] or [2], wherein the hydrophobic portion present at the surface X and the interface Y has the same partial structure, and the hydrophilic portion present at the surface X and the interface Y has the same partial structure. [4] When the secondary ion intensity is measured by time-of-flight secondary ion mass spectrometry while irradiating an ion beam from the surface X toward the interface Y, the ion fragments derived from the hydrophobic portion are detected as Si ３ C ５ H １５ O ３ ＋[5] The optical film according to any one of [1] to [4], wherein the hydrophilic portion is a repeating unit corresponding to at least one monomer selected from the group consisting of methacrylic acid, N-(2-hydroxyethyl)acrylamide, and 2-methacryloyloxyethylphosphorylcholine. [6] The optical film according to any one of [1] to [5], wherein, when secondary ion intensity is measured by time-of-flight secondary ion mass spectrometry while irradiating an ion beam from surface X toward interface Y, the ratio of the peak intensity of ion fragments derived from the hydrophilic portion to the peak intensity of ion fragments derived from the hydrophobic portion detected at interface Y is 0.2 to 0.5.

[0008] According to the present invention, an optical film having excellent adhesion between the optically absorptive anisotropic layer and the protective layer can be provided without subjecting the surface of the optically absorptive anisotropic layer to corona treatment.

[0009] Fig. 1 is a schematic cross-sectional view showing an example of the optical film of the present invention. Fig. 2 is a schematic view showing an example of a head-mounted display having the optical film of the present invention. Fig. 3 is a schematic view showing an example of the configuration of a light guide plate for AR (Augmented Reality) glasses.

[0010] The present invention will be described in detail below. The following description of the constituent elements may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the upper and lower limits. In this specification, the upper or lower limit of a numerical range described in a stepwise manner may be replaced with the upper or lower limit of another stepwise manner. In this specification, the upper or lower limit of a numerical range described in a stepwise manner may be replaced with a value shown in the Examples. In this specification, each component may be a single substance corresponding to the component, or two or more substances may be used in combination. When two or more substances are used in combination for each component, the content of that component refers to the total content of the substances used in combination, unless otherwise specified. In addition, in this specification, "(meth)acrylate" is a notation representing "acrylate" or "methacrylate", "(meth)acrylic" is a notation representing "acrylic" or "methacrylic", and "(meth)acryloyl" is a notation representing "acryloyl" or "methacryloyl".

[0011] [Optical Film] The optical film of the present invention has a light-absorbing anisotropic layer containing a surfactant, a dichroic material, and a liquid crystal compound, and a protective layer provided adjacent to the light-absorbing anisotropic layer. Furthermore, in the optical film of the present invention, the angle θ between the transmittance central axis of the light-absorbing anisotropic layer and the normal direction to the surface of the light-absorbing anisotropic layer is 0° or more and 45° or less. Furthermore, in the optical film of the present invention, the surfactant contained in the light-absorbing anisotropic layer has both a hydrophobic moiety with a ClogP value of 3.5 or more and a hydrophilic moiety with a ClogP value of 1.0 or less and a molecular weight of less than 1,000. Furthermore, in the optical film of the present invention, both the hydrophobic moiety and the hydrophilic moiety are present on a surface X of the protective layer opposite to the optically absorptive anisotropic layer and on an interface Y between the optically absorptive anisotropic layer and the protective layer, and when secondary ion intensity is measured by time-of-flight secondary ion mass spectrometry (TOF-SIMS) while irradiating an ion beam from the surface X toward the interface Y, the peak intensities of ion fragments derived from the hydrophobic moiety detected at the surface X, the interface Y, and the central position Z in the film thickness direction between the interfaces X and Y are Ix, Iy, and Iz, respectively, and satisfy all of the following formulas (1) to (3): Formula (1) Ix / Iz≧2 Formula (2) Iy / Iz≧2 Formula (3) 0.05≦Ix / Iy≦1.5

[0012] Fig. 1 is a schematic cross-sectional view showing an example of the optical film of the present invention. The optical film 14 shown in Fig. 1 has an optically absorptive anisotropic layer 1 and a protective layer 2 adjacent to each other. The angle θ between the central axis of transmittance of the optically absorptive anisotropic layer 1 and the normal to the surface of the optically absorptive anisotropic layer 1 (i.e., the main surface of the optically absorptive anisotropic layer 1) is 0° or more and 45° or less. Furthermore, the optical film 14 shown in Fig. 1 has a surfactant (not shown) that contains both a hydrophobic moiety with a ClogP value of 3.5 or more and a hydrophilic moiety with a ClogP value of 1.0 or less and a molecular weight of less than 1,000 on the surface X of the protective layer 2 opposite the optically absorptive anisotropic layer 1 and on the interface Y between the optically absorptive anisotropic layer 1 and the protective layer 2. Furthermore, when the secondary ion intensity of the optical film 14 shown in FIG. 1 is measured by TOF-SIMS while irradiating the optical film 14 with an ion beam from the surface X toward the interface Y, the peak intensities of ion fragments derived from the hydrophobic portion detected at the surface X, the interface Y, and the central position Z in the film thickness (d) direction between the interfaces X and Y are Ix, Iy, and Iz, respectively, and satisfy all of the above formulas (1) to (3).

[0013] <Transmittance Central Axis> The transmittance central axis of the optically absorbing anisotropic layer refers to the direction showing the highest transmittance when the transmittance is measured by changing the tilt angle (polar angle) and tilt direction (azimuth angle) relative to the normal direction of the optically absorbing anisotropic layer surface. Specifically, the Mueller matrix at a wavelength of 550 nm is measured using an AxoScan (OPMF-2, manufactured by Axometrics). More specifically, during measurement, the azimuth angle at which the transmittance central axis is tilted is first found, and then, within a plane containing the normal direction of the optically absorbing anisotropic layer along that azimuth angle (a plane containing the transmittance central axis and perpendicular to the film surface), the polar angle, which is the angle relative to the normal direction of the optically absorbing anisotropic layer surface, is changed in 1° increments from -70 to 70°, and the Mueller matrix at a wavelength of 550 nm is measured, thereby deriving the transmittance of the optically absorbing anisotropic layer. As a result, the direction with the highest transmittance is determined to be the transmittance central axis. The transmittance central axis means the direction of the absorption axis (the direction of the long axis of the molecule) of the dichroic material contained in the light absorption anisotropic layer.

[0014] <ClogP Value> The ClogP value is the value obtained by calculating the common logarithm logP of the partition coefficient P between 1-octanol and water. Known methods and software can be used to calculate the ClogP value; however, unless otherwise specified, the present invention uses the ClogP program incorporated into PerkinElmer's ChemDraw Professional (version 22.2). Furthermore, the hydrophobic and hydrophilic moieties used to calculate the ClogP value refer to the monomers that form the repeating units contained in the polymer surfactant when the surfactant contained in the optically absorptive anisotropic layer is a polymer surfactant. That is, when the surfactant contained in the optically absorptive anisotropic layer is a polymer surfactant, this polymer surfactant is a copolymer of a monomer having a ClogP value of 3.5 or more and a monomer having a ClogP value of 1.0 or less and a molecular weight of less than 1,000. On the other hand, when the surfactant contained in the optically absorptive anisotropic layer is a low-molecular-weight surfactant, the hydrophobic portion and hydrophilic portion that are the objects of calculation of the ClogP value refer to functional groups with a ClogP value of 3.5 or more (so-called hydrophobic groups) and functional groups with a ClogP value of 1.0 or less and a molecular weight of less than 1,000 (so-called hydrophilic groups), respectively.

[0015] <TOF-SIMS> Ion fragment detection by time-of-flight secondary ion mass spectrometry, i.e., TOF-SIMS, is performed as follows. The presence of hydrophobic portions with a ClogP value of 3.5 or more and hydrophilic portions with a ClogP value of 1.0 or less and a molecular weight of less than 1,000 at the surface X and interface Y is determined by the presence or absence of ion fragment detection. (1) Apparatus and Conditions: Apparatus: TOF-SIMS 5 (manufactured by ION-TOF Inc.); Depth (film thickness) direction analysis: Combined with Ar ion sputtering; Measurement range: Raster scan of 128 points in one direction and in the direction perpendicular thereto; Polarity: Positive, Negative. (2) Peak Intensity: For the object to be measured, i.e., an optical film having an optically absorptive anisotropic layer and a protective layer adjacent to each other, the cross section from the surface X of the protective layer on the side opposite the optically absorptive anisotropic layer to the interface Y between the optically absorptive anisotropic layer and the protective layer is measured at a constant speed in the film thickness direction, and the peak intensities are measured at the following positions: (Surface X) Measure the average value of the mass spectrometry intensity (average value of the intensity from the baseline) of ion fragments derived from the hydrophobic or hydrophilic portion in a region 1% from the surface X in the film thickness direction. (Interface Y) Measure the average value of the mass spectrometry intensity (average value of the intensity from the baseline) of ion fragments derived from the hydrophobic or hydrophilic portion in a region 1% from the interface Y in the film thickness direction. (Center position Z) Measure the mass spectrometry intensity of ion fragments derived from the hydrophobic or hydrophilic portion at a position half the film thickness of the protective layer (i.e., measured at half the measurement time from the surface X to the interface Y).

[0016] In the present invention, as described above, it has been found that when both surface X and interface Y contain hydrophobic moieties with a ClogP value of 3.5 or more and hydrophilic moieties with a ClogP value of 1.0 or less and a molecular weight of less than 1,000, and the peak intensities of ion fragments derived from the hydrophobic moieties at surface X, interface Y, and central position Z in the film thickness direction of these satisfy all of the above formulas (1) to (3), the adhesion between the optically absorbing anisotropic layer and the protective layer is improved even when an optical film is produced without subjecting the surface of the optically absorbing anisotropic layer to corona treatment. The reason for this effect is not clear in detail, but the inventors speculate as follows. First, the inventors have found that the above formulas (1) to (3) can be adjusted by the types and combinations of components (e.g., matrix components, surfactants, etc.) of the optically absorbing anisotropic layer-forming composition and the protective layer-forming composition. Furthermore, the protective layer-forming composition used in Example 1, described below, does not contain surfactants that are unevenly distributed at surface X or interface Y. Therefore, in Example 1 described below, by using a specific surfactant having both a hydrophobic moiety with a ClogP value of 3.5 or more and a hydrophilic moiety with a ClogP value of 1.0 or less and a molecular weight of less than 1,000 as a component of the composition for forming an optically absorbing anisotropic layer, a portion of the specific surfactant unevenly distributed on the surface of the formed optically absorbing anisotropic layer migrated into the composition for forming a protective layer during the formation of the protective layer (when the composition for forming a protective layer was applied), and was further unevenly distributed on the surface of the protective layer, which is thought to have satisfied all of the above formulas (1) to (3). That is, in at least one embodiment of the present invention, the migration of a portion of the specific surfactant unevenly distributed on the surface of the optically absorbing anisotropic layer prevented repelling during the application of the composition for forming a protective layer, which is thought to have improved the adhesion between the optically absorbing anisotropic layer and the protective layer.

[0017] [Light-Absorption Anisotropic Layer] The optically anisotropic layer of the optical film of the present invention is a film containing a surfactant, a liquid crystal compound, and a dichroic substance, and is preferably a film formed by fixing the alignment state of a liquid crystal composition containing a surfactant, a liquid crystal compound, and a dichroic substance. The components contained in the liquid crystal composition will be described in detail below. Note that each component described below is basically also contained in the light-absorption anisotropic layer, but components having a crosslinkable group (including a polymerizable group) are contained in the light-absorption anisotropic layer as a crosslinked (polymerized) component for reasons such as fixing the alignment state.

[0018] <Surfactant> The liquid crystal composition contains a surfactant (specific surfactant) having both a hydrophobic portion with a ClogP value of 3.5 or more and a hydrophilic portion with a ClogP value of 1.0 or less and a molecular weight of less than 1,000. Here, the specific surfactant may be either a polymeric surfactant or a low-molecular-weight surfactant. However, from the viewpoint of improving adhesion, coating surface condition, and ease of designing each function, such as the hydrophobic portion and the hydrophilic portion, according to the intended purpose, a polymeric surfactant is preferred. Note that the term "polymeric surfactant" refers to a surfactant having a repeating unit in its chemical structure, and the term "low-molecular-weight surfactant" refers to a surfactant having no repeating unit in its chemical structure.

[0019] In the present invention, when a polymer surfactant is used as the specific surfactant, in order to simultaneously achieve multiple required functions, a polymer surfactant can be synthesized by appropriately combining a hydrophobic copolymer component, a hydrophilic copolymer component, a copolymer component with intermediate hydrophilicity and hydrophobicity, etc. As a specific function, the hydrophobic copolymer component is used to exhibit surface activity in the coating liquid by unevenly distributing the surfactant at the surface or interface. In practice, commonly used structures include a perfluoroalkyl group and a heteroatom such as an oxygen or sulfur atom in the vicinity thereof, or a structure in which an alkyl group such as a methyl group is attached to a siloxane bond (—Si—O—). Furthermore, when a low-molecular-weight surfactant is used as the specific surfactant, its molecular structure will have a hydrophobic portion (hydrophobic group) for exhibiting surface activity and a hydrophilic portion (hydrophilic group) for imparting other functions. In the present invention, among hydrophilic portions with a ClogP value of 1.0 or less, those with a molecular weight of 1,000 or more are excluded because they do not contribute to the hydrophilicity of the interface or surface. The molecular weight of the surfactant is preferably 5,000 to 100,000, more preferably 8,000 to 50,000, and even more preferably 10,000 to 20,000.

[0020] In the present invention, for the reason that the adhesion between the optical absorption anisotropic layer and the protective layer is improved, when the secondary ion intensity is measured by TOF-SIMS while irradiating an ion beam from the surface X toward the interface Y, the ratio of the peak intensity of ion fragments derived from hydrophilic portions having a ClogP value of 1.0 or less to the peak intensity of ion fragments derived from hydrophobic portions having a ClogP value of 3.5 or more detected at the interface Y is preferably 0.2 to 0.5, and more preferably 0.2 to 0.4.

[0021] In addition, in the present invention, the angle θ between the central axis of transmittance of the optically absorptive anisotropic layer and the normal direction to the surface of the optically absorptive anisotropic layer (hereinafter also abbreviated as "transmittance central axis angle θ") is preferably 0° or more and less than 45°, more preferably 0° or more and 35° or less, and even more preferably 0° or more and less than 35°.

[0022] Furthermore, in the present invention, when secondary ion intensity is measured by TOF-SIMS while irradiating an ion beam from the surface X toward the interface Y, the peak intensities Ix, Iy, and Iz of ion fragments derived from the hydrophobic portion detected at the surface X, the interface Y, and the central position Z in the film thickness direction between the interfaces X and Y preferably satisfy all of the following formulas (1-1) to (3-1), and more preferably satisfy all of the following formulas (1-2) to (3-2): Formula (1-1) Ix / Iz≧3.0 Formula (2-1) Iy / Iz≧3.0 Formula (3-1) 0.1≦Ix / Iy≦1.2 Formula (1-2) Ix / Iz≧5.0 Formula (2-2) Iy / Iz≧5.0 Formula (3-2) 0.3≦Ix / Iy≦1.1

[0023] In the present invention, in order to improve the adhesion between the optically absorptive anisotropic layer and the protective layer, it is preferable that the hydrophobic portion of the specific surfactant having a ClogP value of 3.5 or more is a repeating unit having a siloxane bond in the side chain. Here, the siloxane bond refers to a molecular structure (—Si—O—) in which silicon (Si) and oxygen (O) are bonded alternately.

[0024] In the present invention, for the reason that the adhesion between the light absorption anisotropic layer and the protective layer is improved, it is preferable that the hydrophobic moieties present on the surface X and the interface Y have the same partial structure, and that the hydrophilic moieties present on the surface X and the interface Y have the same partial structure.

[0025] Furthermore, in the present invention, in order to improve the adhesion between the optical absorption anisotropic layer and the protective layer, when the secondary ion intensity is measured by TOF-SIMS while irradiating an ion beam from the surface X toward the interface Y, the ion fragments derived from the hydrophobic portion detected are Si ３ C ５ H １５ O ３ ＋ It is preferable that:

[0026] In the present invention, for reasons such as better adhesion between the optically absorptive anisotropic layer and the protective layer and less likelihood of cissing when the protective layer is applied onto the optically absorptive anisotropic layer, it is preferred that the hydrophilic moiety having a ClogP value of 1.0 or less is a repeating unit corresponding to at least one monomer selected from the group consisting of methacrylic acid, N-(2-hydroxyethyl)acrylamide, and 2-methacryloyloxyethylphosphorylcholine.

[0027] The content of the surfactant is preferably 0.005 to 15% by mass, more preferably 0.01 to 5% by mass, and even more preferably 0.015 to 3% by mass, based on the total mass of the solid content of the liquid crystal composition. When multiple surfactants are used in combination, the total amount of the multiple surfactants is preferably in the above-mentioned range.

[0028] <Liquid Crystal Compound> The liquid crystal composition contains a liquid crystal compound. This allows the dichroic material to be aligned with a higher degree of orientation while suppressing precipitation of the dichroic material. As the liquid crystal compound, either a polymer liquid crystal compound or a low molecular weight liquid crystal compound can be used, with a polymer liquid crystal compound being preferred because it allows for a higher degree of orientation. Furthermore, as the liquid crystal compound, a polymer liquid crystal compound and a low molecular weight liquid crystal compound may be used in combination. Here, the term "polymer liquid crystal compound" refers to a liquid crystal compound having a repeating unit in its chemical structure. The term "low molecular weight liquid crystal compound" refers to a liquid crystal compound having no repeating units in its chemical structure. Examples of polymer liquid crystal compounds include the thermotropic liquid crystal polymers described in JP 2011-237513 A and the polymer liquid crystal compounds described in paragraphs

[0012] to

[0042] of WO 2018 / 199096 A. Examples of low molecular weight liquid crystal compounds include those described in paragraphs

[0072] to

[0088] of JP 2013-228706 A, and among them, liquid crystal compounds exhibiting smectic properties are preferred. Examples of such liquid crystal compounds include those described in paragraphs

[0019] to

[0140] of WO 2022 / 014340 A, the disclosures of which are incorporated herein by reference.

[0029] The content of the liquid crystal compound is preferably 25 to 2000 parts by mass, more preferably 100 to 1300 parts by mass, and even more preferably 200 to 900 parts by mass, relative to 100 parts by mass of the content of the dichroic material described below. When the content of the liquid crystal compound is within the above range, the degree of orientation of the dichroic material is further improved. The liquid crystal compound may be contained alone, or two or more types may be contained. When two or more types of liquid crystal compounds are contained, the content of the liquid crystal compound refers to the total content of the liquid crystal compounds.

[0030] <Dichroic Material> The liquid crystal composition contains a dichroic material. Here, the dichroic material refers to a dye whose absorbance varies depending on the direction. The dichroic material may or may not exhibit liquid crystallinity.

[0031] The dichroic substance is not particularly limited, and examples thereof include visible light absorbing substances (dichroic dyes), luminescent substances (fluorescent substances, phosphorescent substances), ultraviolet absorbing substances, infrared absorbing substances, nonlinear optical substances, carbon nanotubes, and inorganic substances (e.g., quantum rods), and any conventionally known dichroic substance (dichroic dye) can be used. Specifically, for example, paragraphs

[0067] to

[0071] of JP 2013-228706 A, paragraphs

[0008] to

[0026] of JP 2013-227532 A, paragraphs

[0008] to

[0015] of JP 2013-209367 A, paragraphs

[0045] to

[0058] of JP 2013-14883 A, paragraphs

[0012] to

[0029] of JP 2013-109090 A, paragraphs

[0009] to

[0017] of JP 2013-101328 A, Paragraphs

[0051] to

[0065] of JP 2013-37353 A, paragraphs

[0049] to

[0073] of JP 2012-63387 A, paragraphs

[0016] to

[0018] of JP 11-305036 A, paragraphs

[0009] to

[0011] of JP 2001-133630 A, paragraphs

[0030] to

[0169] of JP 2011-215337 A, paragraphs

[0021] to

[0075] of JP 2010-106242 A, paragraphs

[0016] to

[0018] of JP 2010-215846 A

[0011] to

[0025] paragraphs,

[0017] to

[0069] paragraphs of JP 2011-048311 A,

[0013] to

[0133] paragraphs of JP 2011-213610 A,

[0074] to

[0246] paragraphs of JP 2011-237513 A,

[0005] to

[0051] paragraphs of JP 2016-006502 A,

[0014] to

[0032] paragraphs of JP 2018-053167 A, and

[0014] to

[0033] paragraphs of JP 2020-11716 A paragraphs

[0005] to

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

[0008] to

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

[0014] to

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

[0014] to

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

[0013] to

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

[0014] to

[0034] of International Publication No. 2018 / 164252,Examples include those described in paragraphs

[0021] to

[0030] of International Publication No. 2018 / 186503, paragraphs

[0043] to

[0063] of International Publication No. 2019 / 189345, paragraphs

[0043] to

[0085] of International Publication No. 2019 / 225468, paragraphs

[0050] to

[0074] of International Publication No. 2020 / 004106, and paragraphs

[0015] to

[0038] of International Publication No. 2021 / 044843.

[0032] As the dichroic substance, a dichroic azo dye compound is preferred. A dichroic azo dye compound refers to an azo dye compound whose absorbance varies depending on the direction. A dichroic azo dye compound may or may not exhibit liquid crystallinity. When a dichroic azo dye compound exhibits liquid crystallinity, it may exhibit either nematic or smectic properties. The temperature range in which the liquid crystal phase is exhibited is preferably room temperature (approximately 20 to 28°C) to 300°C, and more preferably 50 to 200°C from the viewpoints of handleability and manufacturing suitability.

[0033] In the present invention, from the viewpoint of adjusting color hue, it is preferable to use, as the dichroic substance, a mixture containing at least a dye compound (particularly, a dichroic azo dye compound) having an absorption maximum in a wavelength range of 380 nm or more and less than 455 nm, a dye compound (particularly, a dichroic azo dye compound) having an absorption maximum in a wavelength range of 455 nm or more and less than 560 nm, and a dye compound (particularly, a dichroic azo dye compound) having an absorption maximum in a wavelength range of 560 nm or more and less than 700 nm.

[0034] In particular, in the present invention, it is preferable that the dye compound having a maximum absorption wavelength in the wavelength range of 380 nm or more and less than 455 nm contains a dichroic azo dye compound represented by the following formula (1).

[0035]

[0036] In the formula (1), A and B each independently represent a crosslinkable group. In the formula (1), a and b each independently represent 0 or 1, provided that a+b≧1. In the formula (1), when a=0, L １ represents a monovalent substituent, and when a=1, L １represents a single bond or a divalent linking group. ２ represents a monovalent substituent, and when b=1, L ２ represents a single bond or a divalent linking group. １ represents an (n1+2)-valent aromatic hydrocarbon group or heterocyclic group, Ar ２ represents an (n2+2)-valent aromatic hydrocarbon group or heterocyclic group, Ar ３ represents an (n3+2)-valent aromatic hydrocarbon group or heterocyclic group. １ , R ２ and R ３ each independently represents a monovalent substituent. When n1≧2, a plurality of R １ may be the same or different, and when n2≧2, a plurality of R ２ may be the same or different, and when n3≧2, a plurality of R ３ In the above formula (1), k represents an integer of 1 to 4. When k is 2 or more, a plurality of Ar ２ may be the same or different, and multiple R ２ may be the same or different. In the above formula (1), n1, n2, and n3 each independently represent an integer of 0 to 4. However, when k = 1, n1 + n2 + n3 ≧ 0, and when k ≧ 2, n1 + n2 + n3 ≧ 1. Explanations and examples of each symbol in the above formula (1) include those described in paragraphs

[0013] to

[0038] of WO 2017 / 195833, and these descriptions are incorporated herein by reference.

[0037] In the present invention, the dichroic azo dye compound represented by the above formula (1) is preferably a dichroic azo dye compound having a dichroic substance-derived endothermic peak at an endothermic onset temperature of 105° C. or higher, and ... １ ~Ar ３ Each of these represents a phenylene group, and R １ and R ３represents a halogen atom (especially chlorine) located at the ortho position of the azo bond (-N=N-), and when n2 is 1, R ２ represents an alkyl group (especially a methyl group), and L １ and L ２ Preferably, each of A and B represents an alkylene group having 2 to 6 carbon atoms, and A and B represent a (meth)acryloyloxy group.

[0038] The content of the dichroic material contained in the optically absorptive anisotropic layer is not particularly limited, but is preferably 3% by mass or more, more preferably 8% by mass or more, even more preferably 10% by mass or more, and particularly preferably 10 to 30% by mass, relative to the total mass of the optically absorptive anisotropic layer, because this increases the degree of orientation of the optically absorptive anisotropic layer that is formed. When multiple dichroic materials are used in combination, the total amount of the multiple dichroic materials is preferably within the above-mentioned range. Furthermore, the content of the dichroic material contained in the optically absorptive anisotropic layer is preferably 20 to 650 mg / cm, because this increases the degree of orientation of the optically absorptive anisotropic layer that is formed. ３ is preferably 25 to 500 mg / cm ３ is preferably 30 to 200 mg / cm ３ More preferably, it is 40 to 150 mg / cm ３ When a plurality of dichroic substances are used in combination, the total amount of the dichroic substances is preferably in the above-mentioned range. ３ The dichroic substance content can be obtained by measuring a solution in which a laminate having an optically absorptive anisotropic layer is dissolved or an extract obtained by immersing the laminate in a solvent using high-performance liquid chromatography (HPLC), but is not limited to the above method. Quantification can be performed using the dichroic substance contained in the optically absorptive anisotropic layer as a standard sample. One example of a method for calculating the content of the dichroic substance is to calculate the volume by multiplying the thickness of the optically absorptive anisotropic layer obtained from a microscopic image of the cross section of the laminate by the area of ​​the optical laminate used to measure the dye amount, and then dividing the volume by the amount of dye measured by HPLC to calculate the dye content.

[0039] <Vertical Alignment Agent> The liquid crystal composition preferably contains a vertical alignment agent. Here, the vertical alignment agent refers to an additive that has the function of aligning the liquid crystal compound in a direction perpendicular to the main plane of the light-absorption anisotropic layer. Note that "vertical alignment" does not require alignment at a strict 90° angle, but means alignment at an angle of 70 to 110°.

[0040] Examples of the vertical alignment agent include an ionic vertical alignment agent and a vertical alignment agent having a boronic acid group, and it is preferable to use an ionic vertical alignment agent and a vertical alignment agent having a boronic acid group in combination.

[0041] Suitable examples of the ionic vertical alignment agent include onium compounds represented by the following formula (B1).

[0042] In the formula (B1), ring A represents a quaternary ammonium ion consisting of a nitrogen-containing heterocycle, and X represents an anion. １ represents a divalent linking group. ２ represents a single bond or a divalent linking group. １ represents a divalent linking group having a 5-membered or 6-membered ring as a partial structure. Z represents a divalent linking group having an alkylene group having 2 to 20 carbon atoms as a partial structure. P １ and P ２ each independently represents a monovalent substituent having a polymerizable ethylenically unsaturated bond.

[0043] Ring A represents a quaternary ammonium ion consisting of a nitrogen-containing heterocycle. Examples of ring A include a pyridine ring, a picoline ring, a 2,2'-bipyridyl ring, a 4,4'-bipyridyl ring, a 1,10-phenanthroline ring, a quinoline ring, an oxazole ring, a thiazole ring, an imidazole ring, a pyrazine ring, a triazole ring, and a tetrazole ring, and are preferably a quaternary imidazolium ion or a quaternary pyridinium ion.

[0044] X represents an anion. Examples of X include halogen anions (e.g., fluorine ion, chloride ion, bromide ion, iodide ion, etc.), sulfonate ions (e.g., methanesulfonate ion, trifluoromethanesulfonate ion, methyl sulfate ion, vinyl sulfonate ion, allyl sulfonate ion, p-toluenesulfonate ion, p-chlorobenzenesulfonate ion, p-vinylbenzenesulfonate ion, 1,3-benzenedisulfonate ion, 1,5-naphthalenedisulfonate ion, 2,6-naphthalenedisulfonate ion, etc.), sulfate ion, carbonate ion, nitrate ion, thiocyanate ion, perchlorate ion, tetrafluoroborate ion, picrate ion, acetate ion, benzoate ion, p-vinylbenzoate ion, formate ion, trifluoroacetate ion, phosphate ion (e.g., hexafluorophosphate ion), hydroxide ion, etc. Preferred are halogen anions, sulfonate ions, and hydroxide ions. Particularly preferred are chloride ions, bromide ions, iodide ions, methanesulfonate ions, vinylsulfonate ions, p-toluenesulfonate ions, and p-vinylbenzenesulfonate ions.

[0045] L １ represents a divalent linking group. １ Examples of the group include an alkylene group, —O—, —S—, —CO—, and —SO ２ -, -NRa- (wherein Ra is an alkyl group having 1 to 5 carbon atoms or a hydrogen atom), an alkenylene group, an alkynylene group, or a divalent linking group having 1 to 20 carbon atoms formed in combination with an arylene group. １ is preferably -AL-, -O-AL-, -CO-O-AL-, or -O-CO-AL- having 1 to 10 carbon atoms, more preferably -AL- or -O-AL- having 1 to 10 carbon atoms, and most preferably -AL- or -O-AL- having 1 to 5 carbon atoms. AL represents an alkylene group.

[0046] L2 represents a single bond or a divalent linking group. ２ Examples of the group include an alkylene group, —O—, —S—, —CO—, and —SO ２-, -NRa- (wherein Ra is an alkyl group having 1 to 5 carbon atoms or a hydrogen atom), an alkenylene group, a divalent linking group having 1 to 10 carbon atoms formed in combination with an alkynylene group or an arylene group, a single bond, -O-, -O-CO-, -CO-O-, -O-AL-O-, -O-AL-O-CO-, -O-AL-CO-O-, -CO-O-AL-O-, -CO-O-AL-O-CO-, -CO-O-AL-CO-O-, -O-CO-AL-O-, -O-CO-AL-O-CO-, -O-CO-AL-CO-O-, and the like. AL represents an alkylene group. L2 is preferably a single bond, -AL-, -O-AL-, or -NRa-AL-O- having 1 to 10 carbon atoms, more preferably a single bond, -AL-, -O-AL-, or -NRa-AL-O- having 1 to 5 carbon atoms, and most preferably a single bond, or -O-AL- or -NRa-AL-O- having 1 to 5 carbon atoms.

[0047] Y １ represents a divalent linking group having a 5- or 6-membered ring as a partial structure. １ Examples of the aromatic ring include a cyclohexyl ring, an aromatic ring, a heterocyclic ring, etc. Examples of the aromatic ring include a benzene ring, an indene ring, a naphthalene ring, a fluorene ring, a phenanthrene ring, an anthracene ring, a biphenyl ring, and a pyrene ring, with a benzene ring, a biphenyl ring, and a naphthalene ring being particularly preferred. The heteroatom constituting the heterocycle is preferably a nitrogen atom, an oxygen atom, or a sulfur atom, and examples thereof include a furan ring, a thiophene ring, a pyrrole ring, a pyrroline ring, a pyrrolidine ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an imidazoline ring, an imidazolidine ring, a pyrazole ring, a pyrazoline ring, a pyrazolidine ring, a triazole ring, a furazan ring, a tetrazole ring, a pyran ring, a dioxane ring, a dithiane ring, a thiine ring, a pyridine ring, a piperidine ring, an oxazine ring, a morpholine ring, a thiazine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a piperazine ring, and a triazine ring. The heterocycle is preferably a 6-membered ring. Y １ The divalent linking group having a 5- or 6-membered ring as a partial structure, represented by the following formula (I), may further have a substituent (for example, the above-mentioned substituent W).

[0048] Y １ The divalent linking group represented by the formula (I) is preferably a divalent linking group having two or more 5- or 6-membered rings, and more preferably has a structure in which two or more rings are linked by a linking group. Examples of the linking group include L １ and L ２ Examples of the linking group include -C≡C-, -CH=CH-, -CH=N-, -N=CH-, and -N=N-.

[0049] Z represents a divalent linking group having an alkylene group having 2 to 20 carbon atoms as a partial structure and formed by combining -O-, -S-, -CO-, or -SO2-, and the alkylene group may have a substituent. Examples of the divalent linking group include an alkyleneoxy group and a polyalkyleneoxy group. The alkylene group represented by Z preferably has 2 to 16 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably 2 to 8 carbon atoms.

[0050] P1 and P2 each independently represent a monovalent substituent having a polymerizable ethylenically unsaturated group. Examples of the monovalent substituent having a polymerizable ethylenically unsaturated group include the following formulae (M-1) to (M-8). That is, the monovalent substituent having a polymerizable ethylenically unsaturated group may be a substituent consisting only of an ethenyl group, as in (M-8).

[0051]

[0052] In formulas (M-3) and (M-4), R represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group. Among the formulas (M-1) to (M-8), (M-1), (M-2), and (M-8) are preferred, with (M-1) or (M-8) being more preferred. In particular, (M-1) is preferred as P1. Furthermore, (M-1) or (M-8) is preferred as P2. In compounds in which ring A is a quaternary imidazolium ion, P2 is preferably (M-8) or (M-1), and in compounds in which ring A is a quaternary pyridinium ion, P2 is preferably (M-1).

[0053] Examples of the onium compound represented by formula (B1) include the onium salts described in paragraphs

[0052] to

[0058] of JP-A No. 2012-208397, the onium salts described in paragraphs

[0024] to

[0055] of JP-A No. 2008-026730, and the onium salts described in JP-A No. 2002-37777.

[0054] As the ionic vertical alignment agent, in addition to the onium compound represented by the above formula (B1), for example, those described in paragraphs

[0017] to

[0029] of JP-A-2020-181150 can be mentioned.

[0055] A preferred example of the vertical alignment agent having a boronic acid group is a boronic acid compound represented by the following formula (B2).

[0056] In (B2) above, R １ and R ２ each independently represents a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aryl group which may have a substituent, or a heterocyclic group which may have a substituent. ３ represents a substituent.

[0057] R １ and R ２ Examples of the aliphatic hydrocarbon group represented by one embodiment of the formula include substituted or unsubstituted linear or branched alkyl groups having 1 to 20 carbon atoms (e.g., methyl, ethyl, isopropyl, etc.), substituted or unsubstituted cyclic alkyl groups having 3 to 20 carbon atoms (e.g., cyclohexyl, etc.), and alkenyl groups having 2 to 20 carbon atoms (e.g., vinyl, etc.). １ and R ２ Examples of the aryl group represented by one embodiment of R include a substituted or unsubstituted phenyl group having 6 to 20 carbon atoms (for example, a phenyl group, a tolyl group, etc.), and a substituted or unsubstituted naphthyl group having 10 to 20 carbon atoms. １ and R ２Examples of the heterocyclic group represented by one embodiment of R include substituted or unsubstituted 5- or 6-membered ring groups containing at least one heteroatom (e.g., nitrogen atom, oxygen atom, sulfur atom, etc.), and specific examples include a pyridyl group, an imidazolyl group, a furyl group, a piperidyl group, and a morpholino group. １ and R ２ may be linked together to form a ring, for example, R １ and R ２ The isopropyl groups may be linked to form a 4,4,5,5-tetramethyl-1,3,2-dioxaborolane ring.

[0058] R １ and R ２ is preferably a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, or a ring formed by linking these groups, and more preferably a hydrogen atom.

[0059] R ３ is preferably a substituent containing a functional group capable of bonding to a (meth)acrylic group. Here, examples of the functional group capable of bonding to a (meth)acrylic group include a vinyl group, an acrylate group, a methacrylate group, an acrylamide group, a styryl group, a vinyl ketone group, a butadiene group, a vinyl ether group, an oxiranyl group, an aziridinyl group, and an oxetane group. Among these, a vinyl group, an acrylate group, a methacrylate group, a styryl group, an oxiranyl group, or an oxetane group is preferred, and a vinyl group, an acrylate group, an acrylamide group, or a styryl group is more preferred.

[0060] R ３is preferably a substituted or unsubstituted aliphatic hydrocarbon group, an aryl group, or a heterocyclic group having a functional group capable of bonding to a (meth)acrylic group. Examples of the aliphatic hydrocarbon group include a substituted or unsubstituted linear or branched alkyl group having 1 to 30 carbon atoms (e.g., methyl group, ethyl group, isopropyl group, n-propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, hexadecyl group, octadecyl group, eicosyl group, isopropyl group, isobutyl group, sec-butyl group, tert Examples of the aryl group include substituted or unsubstituted phenyl groups having 6 to 50 carbon atoms (e.g., phenyl, tolyl, styryl, 4-benzoyloxyphenyl, 4-phenoxycarbonylphenyl, 4-biphenyl, 4-(4-octyloxybenzoyloxy)phenoxycarbonylphenyl), and substituted or unsubstituted naphthyl groups having 10 to 50 carbon atoms (e.g., unsubstituted naphthyl).Examples of heterocyclic groups include substituted or unsubstituted 5- or 6-membered ring groups containing at least one heteroatom (e.g., nitrogen atom, oxygen atom, sulfur atom, etc.), and examples thereof include pyrrole, furan, thiophene, pyrazole, imidazole, triazole, oxazole, isoxazole, oxadiazole, thiazole, thiadiazole, indole, carbazole, benzofuran, dibenzofuran, thianaphthene, dibenzothiophene, indazole, benzimidazole, anthranil, benzisoxazole, benzoxazole, benzothiazole, purine, pyridine, pyridazine, pyrimidine, pyrazine, triazine, quinoline, acridine, isoquinoline, phthalazine, quinazoline, quinoxaline, naphthyridine, phenanthroline, pteridine, morpholine, and piperidine groups.

[0061] Examples of the boronic acid compound represented by formula (B2) include the boronic acid compounds represented by general formula (I) described in paragraphs 0023 to 0032 of JP-A No. 2008-225281. Preferred examples of the compound represented by formula (B2) include the compounds exemplified below.

[0062]

[0063] When the liquid crystal composition contains a vertical alignment agent, the content of the vertical alignment agent is preferably 1.0 to 7.0 parts by mass, more preferably 1.5 to 8.0 parts by mass, and even more preferably 2.5 to 6.0 parts by mass, relative to 100 parts by mass of the liquid crystal compound. The vertical alignment agent may be contained alone or in combination of two or more types. When two or more types of liquid crystal compounds are contained, the content of the vertical alignment agent refers to the total content of the vertical alignment agents.

[0064] <Solvent> The liquid crystal composition preferably contains a solvent from the viewpoint of workability and the like. Examples of the solvent include ketones (e.g., acetone, 2-butanone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, acetylacetone, etc.), ethers (e.g., dioxane, tetrahydrofuran, tetrahydropyran, dioxolane, tetrahydrofurfuryl alcohol, cyclopentyl methyl ether, dibutyl ether, etc.), aliphatic hydrocarbons (e.g., hexane, etc.), alicyclic hydrocarbons (e.g., cyclohexane, etc.), aromatic hydrocarbons (e.g., benzene, toluene, xylene, tetralin, trimethylbenzene, etc.), halogenated carbons (e.g., dichloromethane, trichloromethane (chloroform), dichloroethane, dichlorobenzene, 1,1,2,2-tetrachloroethane, chlorotoluene, etc.), esters (e.g., methyl acetate, ethyl acetate, butyl acetate, diethyl carbonate, ethyl acetoacetate, n-pentyl acetate, ethyl benzoate, benzyl benzoate, butyl carbitol acetate, diethylene glycol monoethyl ether acetate, Examples of suitable solvents include organic solvents such as ethanol, isopropanol, butanol, cyclohexanol, furfuryl alcohol, 2-ethylhexanol, octanol, benzyl alcohol, ethanolamine, ethylene glycol, propylene glycol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, phenols (e.g., phenol, cresol, etc.), cellosolves (e.g., methyl cellosolve, ethyl cellosolve, 1,2-dimethoxyethane, etc.), cellosolve acetates, sulfoxides (e.g., dimethyl sulfoxide, etc.), amides (e.g., dimethylformamide, dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, etc.), and heterocyclic compounds (e.g., pyridine, 2,6-lutidine, etc.), as well as water. These solvents may be used alone or in combination of two or more.

[0065] When the liquid crystal composition contains a solvent, the content of the solvent is preferably 60 to 99.5% by mass, more preferably 70 to 99% by mass, and particularly preferably 75 to 98% by mass, relative to the total mass (100% by mass) of the liquid crystal composition.

[0066] <Polymerization initiator> The liquid crystal composition may contain a polymerization initiator. There are no particular limitations on the polymerization initiator, but it is preferably a photosensitive compound, i.e., a photopolymerization initiator. As the photopolymerization initiator, various compounds can be used without particular limitations. Examples of photopolymerization initiators include α-carbonyl compounds (U.S. Pat. Nos. 2,367,661 and 2,367,670), acyloin ethers (U.S. Pat. No. 2,448,828), α-hydrocarbon-substituted aromatic acyloin compounds (U.S. Pat. No. 2,722,512), polynuclear quinone compounds (U.S. Pat. Nos. 3,046,127 and 2,951,758), and combinations of triarylimidazole dimers and p-aminophenyl ketones (U.S. Pat. No. 3,549,367). ), acridine and phenazine compounds (JP 60-105667 A and U.S. Pat. No. 4,239,850 A), oxadiazole compounds (U.S. Pat. No. 4,212,970 A), o-acyloxime compounds (JP 2016-27384 A

[0065] ), and acylphosphine oxide compounds (JP 63-40799 A, JP 5-29234 A, JP 10-95788 A, and JP 10-29997 A). Commercially available photopolymerization initiators can also be used, including Irgacure-184, Irgacure-907, Irgacure-369, Irgacure-651, Irgacure-819, Irgacure-OXE-01, and Irgacure-OXE-02 manufactured by BASF.

[0067] When the liquid crystal composition contains a polymerization initiator, the content of the polymerization initiator is preferably 0.01 to 30% by mass, more preferably 0.1 to 15% by mass, based on the total solid mass of the liquid crystal composition.

[0068] [Method for Producing Optically Absorbent Anisotropic Layer] The method for producing the optically absorptive anisotropic layer of the present invention is not particularly limited, and examples thereof include a method comprising, in this order, a step of applying the above-described liquid crystal composition (hereinafter also referred to as "optically absorptive anisotropic layer-forming composition") to form a coating film (hereinafter also referred to as "coating film formation step"), and a step of orienting the liquid crystalline component and dichroic substance contained in the coating film (hereinafter also referred to as "orientation step"). Note that the liquid crystalline component refers to a component that includes not only the above-described liquid crystal compound, but also the dichroic substance having liquid crystallinity, if the above-described dichroic substance has liquid crystallinity.

[0069] <Coating Film Forming Step> The coating film forming step is a step of forming a coating film by applying a composition for forming an optically absorbing anisotropic layer. The composition for forming an optically absorbing anisotropic layer can be easily applied by using a composition for forming an optically absorbing anisotropic layer containing the above-mentioned solvent, or by using a composition for forming an optically absorbing anisotropic layer that has been converted into a liquid such as a molten liquid by heating or the like. Specific examples of methods for applying the composition for forming an optically absorbing anisotropic layer include known methods such as roll coating, gravure printing, spin coating, wire bar coating, extrusion coating, direct gravure coating, reverse gravure coating, die coating, spraying, and inkjet printing.

[0070] In the present invention, the coating amount of the dichroic material in the coating film forming step is set to 15 mg / m because the optical effect (for example, viewing angle control) is enhanced. ２ It is preferable that the concentration is 50 to 1000 mg / m or more. ２ More preferably, it is 200 to 800 mg / m ２ It is more preferable that:

[0071] <Orientation Step> The orientation step is a step of orienting the liquid crystalline component contained in the coating film. This results in an optically absorptive anisotropic layer. The orientation step may include a drying treatment. Components such as the solvent can be removed from the coating film by the drying treatment. The drying treatment may be performed by leaving the coating film at room temperature for a predetermined time (e.g., natural drying), or by heating and / or blowing air. Here, the liquid crystalline component contained in the composition for forming an optically absorptive anisotropic layer may be aligned by the above-described coating film formation step or drying treatment. For example, in an embodiment in which the composition for forming an optically absorptive anisotropic layer is prepared as a coating liquid containing a solvent, the coating film is dried to remove the solvent from the coating film, thereby obtaining a coating film with optical absorptive anisotropy (i.e., an optically absorptive anisotropic layer). When the drying treatment is performed at a temperature equal to or higher than the transition temperature of the liquid crystalline component contained in the coating film to a liquid crystal phase, the heat treatment described below may not be performed.

[0072] The transition temperature of the liquid crystalline component contained in the coating film to the liquid crystal phase is preferably 10 to 250°C, more preferably 25 to 190°C, from the viewpoint of manufacturability and the like. When the transition temperature is 10°C or higher, no cooling treatment or the like is required to lower the temperature to the temperature range in which the liquid crystal phase is exhibited, and this is preferable. Furthermore, when the transition temperature is 250°C or lower, high temperatures are not required even when the film is once converted to an isotropic liquid state at a temperature higher than the temperature range in which the liquid crystal phase is exhibited, and this is preferable because waste of thermal energy and deformation and deterioration of the substrate can be reduced.

[0073] The orientation step preferably includes a heat treatment. This allows the liquid crystalline component contained in the coating film to be oriented, and the heat-treated coating film can be suitably used as a light absorption anisotropic layer. From the viewpoint of manufacturability, the heat treatment is preferably performed at a temperature of 10 to 250°C, more preferably 25 to 190°C. The heating time is preferably 1 to 300 seconds, more preferably 1 to 60 seconds.

[0074] The alignment step may include a cooling treatment carried out after the heating treatment. The cooling treatment is a treatment in which the coated film after heating is cooled to about room temperature (20 to 25°C). This allows the alignment of the liquid crystalline component contained in the coated film to be fixed. The cooling method is not particularly limited and can be carried out by a known method. A light absorption anisotropic layer can be obtained by the above steps. In this embodiment, drying treatment and heating treatment are mentioned as methods for aligning the liquid crystalline component contained in the coated film, but the method is not limited thereto and can be carried out by a known alignment treatment.

[0075] <Other Steps> The method for forming the optically absorbing anisotropic layer may include a step of curing the optically absorbing anisotropic layer (hereinafter also referred to as a "curing step") after the alignment step. For example, when the optically absorbing anisotropic layer has a crosslinkable group (polymerizable group), the curing step is performed by heating and / or light irradiation (exposure). Among these, the curing step is preferably performed by light irradiation. Various light sources, such as infrared, visible light, or ultraviolet light, can be used as the light source for curing, but ultraviolet light is preferred. Furthermore, ultraviolet light may be irradiated while heating during curing, or ultraviolet light may be irradiated through a filter that transmits only specific wavelengths. When exposure is performed while heating, the heating temperature during exposure is preferably 25 to 140°C, although this depends on the transition temperature of the liquid crystal component contained in the liquid crystal film to the liquid crystal phase. Furthermore, exposure may be performed under a nitrogen atmosphere. When curing of the liquid crystal film proceeds by radical polymerization, exposure under a nitrogen atmosphere is preferred because inhibition of polymerization by oxygen is reduced.

[0076] The thickness of the optically absorptive anisotropic layer is not particularly limited, but is preferably 1.5 μm or more, more preferably 2 to 10 μm, and even more preferably 2 to 8 μm. Here, the thickness of the optically absorptive anisotropic layer is measured by cutting the layer with a microtome to prepare a cross-section of the layer, and then observing the cross-section with a scanning electron microscope from the normal direction to the cross-section.

[0077] [Protective Layer] The protective layer of the optical film of the present invention is a layer provided adjacent to the above-mentioned light absorption anisotropic layer. The protective layer may be made of any known material, but a resin film is preferred. Examples of the resin film include polyvinyl alcohol (PVA) resin film, acrylic resin film, cellulose ester resin film, polyethylene terephthalate resin film, and polycarbonate resin film. Among these, a PVA resin film is preferred because it allows the effects of the present invention to be more clearly demonstrated.

[0078] The protective layer is preferably optically isotropic. Here, "optically isotropic" means that the in-plane retardation at a wavelength of 550 nm is 0 to 10 nm and the retardation in the thickness direction at a wavelength of 550 nm is -10 to 10 nm. The thickness of the protective layer is not particularly limited, but is preferably 0.1 to 50 μm.

[0079] The optical film of the present invention may have at least one of a polarizer layer, an antireflection layer and a retardation layer, which will be described later, in addition to the light absorption anisotropic layer and the protective layer described above.

[0080] [Polarizer Layer] The polarizer layer is not particularly limited as long as it is a member capable of converting light into specific linearly polarized light, and conventionally known absorptive polarizers and reflective polarizers can be used. Examples of absorptive polarizers include iodine-based polarizers, dye-based polarizers using dichroic dyes, and polyene-based polarizers. Iodine-based polarizers and dye-based polarizers include coated polarizers and stretched polarizers, and either can be used. However, coated polarizers are preferred. In addition, methods for obtaining a polarizer by stretching and dyeing a laminated film having a polyvinyl alcohol layer formed on a substrate are described in Japanese Patent Nos. 5048120, 5143918, 4691205, 4751481, and 4751486. ​​These known techniques related to polarizers can also be preferably used. Examples of coated polarizers include those disclosed in WO2018 / 124198, WO2018 / 186503, WO2019 / 132020, WO2019 / 132018, WO2019 / 189345, JP2019-197168A, JP2019-194685A, and JP2019-139222A, and known techniques relating to these polarizers can also be preferably utilized. Examples of reflective polarizers that can be used include polarizers in which thin films with different birefringences are laminated, wire grid polarizers, and polarizers in which a cholesteric liquid crystal having a selective reflection region is combined with a quarter-wave plate. Among these, polyvinyl alcohol-based resins (-CH ２A polymer containing -CHOH- as a repeating unit. In particular, a polarizer containing at least one selected from the group consisting of polyvinyl alcohol and an ethylene-vinyl alcohol copolymer is preferred. Furthermore, from the viewpoint of imparting crack resistance, the polarizer may have depolarizing portions formed along opposing edges. Examples of depolarizing portions include those described in JP 2014-240970 A. The polarizer may also have non-polarizing portions arranged at predetermined intervals in the longitudinal direction and / or width direction. The non-polarizing portions are partially bleached portions. The arrangement pattern of the non-polarizing portions can be appropriately set depending on the purpose. For example, when the polarizer is cut (cut, punched, etc.) to a predetermined size for installation in an image display device of a predetermined size, the non-polarizing portions are arranged in positions corresponding to the camera portion of the image display device. Examples of arrangement patterns of non-polarizing portions include those described in JP 2016-27392 A.

[0081] [Antireflection Layer] The antireflection layer is not particularly limited, and a known antireflection layer can be used. Examples of the antireflection layer include the antireflection layers described in paragraphs 0108 to 0121 of WO 2016 / 047648, the contents of which are incorporated herein by reference.

[0082] [Retardation layer] There is no particular limitation on retardation layer, and known retardation layer can be used.For example, retardation layer can be stretched polycarbonate film, stretched norbornene polymer film, transparent film containing and oriented inorganic particles having birefringence such as strontium carbonate, thin film obtained by obliquely depositing inorganic dielectric on support, film that uniaxially oriented and fixed orientation of liquid crystal compound, etc.In addition, as retardation layer, film that uniaxially oriented and fixed orientation of the above-mentioned liquid crystal compound is preferred.

[0083] [Image display device] The image display device is an image display device having the optical film of the present invention (hereinafter also referred to as "the image display device of the present invention"). The display element used in the image display device of the present invention is not particularly limited, and examples thereof include a liquid crystal cell, an organic electroluminescence (hereinafter abbreviated as "EL") display panel, an inorganic EL display panel, and a plasma display panel.

[0084] [Viewing Angle Switching Device] The image display device of the present invention may be an image display device having the optical film of the present invention and an electronically controlled viewing angle switching cell, i.e., an image display device (viewing angle switching device) capable of switching the viewing angle. By using the optical film of the present invention, it is possible to narrow the light exit angle. Various types of image display devices capable of switching the viewing angle are known, and the optical film of the present invention can be used for the purpose of generating light with a narrow exit angle. For example, after generating light with a narrow exit angle using the optical film of the present invention, the light can be passed through an element that controls the diffusion of the light, as described in JP-A-9-105907, thereby switching between a narrow viewing angle and a wide viewing angle. Alternatively, as described in JP 2017-098246 A, the optical film of the present invention can be used as the optical filter element in a narrow / wide viewing angle switchable backlight system including, from the viewing side, an inverted prism sheet, a first light guide plate that introduces light into the inverted prism sheet at a relatively large incident angle (light exiting from the inverted prism sheet has a narrow viewing angle), an optical filter element that absorbs obliquely incident light and transmits light with a narrow exit angle to the inverted prism sheet at a relatively small incident angle, and a second light guide plate (light exiting from the inverted prism sheet has a narrow viewing angle). The optical film of the present invention can also be used as the optical filter in a backlight system including, from the viewing side, a first light guide plate, an optical filter that absorbs obliquely incident light and emits light at a narrow angle, and a second light guide plate, wherein the first and second light guide plates have a wide viewing angle when light exits from the first light guide plate and a narrow viewing angle when light exits only from the second light guide plate. Furthermore, a retardation modulation element such as a liquid crystal cell can be disposed between the optical film of the present invention and the horizontally aligned polarizer to switch between a narrow viewing angle and a wide viewing angle. For example, when a VA-mode or ECB-mode liquid crystal cell is used as the retardation modulation cell, the viewing angle becomes narrow when the liquid crystal in the liquid crystal cell is vertically aligned, and becomes wide viewing angle mode when the liquid crystal in the liquid crystal cell is tilted, and the narrow viewing angle / wide viewing angle can be controlled by applying or not applying a voltage to the cell. Furthermore, an IPS-mode liquid crystal cell can also be used as the retardation modulation cell.The alignment direction of the liquid crystal cell when no voltage is applied and the absorption axis direction of the horizontally aligned polarizer are set parallel or perpendicular to each other, and by applying a voltage to change the alignment direction of the liquid crystal cell, the viewing angle can be switched from a narrow viewing angle to a wide viewing angle. Furthermore, a TN-mode liquid crystal cell can also be used as the retardation modulation cell. A cell in which the twist angle of the alignment can be switched between 0° and 90° or between 0° and 270° by turning the voltage on and off is preferred. Additionally, the image display device of the present invention may be configured to be capable of independently switching the viewing angles of multiple regions within the display screen.

[0085] [Optical Device / Head-Mounted Display] The optical film of the present invention can be used in an optical device (head-mounted display) having a light guide plate on the surface of which a diffractive element is arranged.

[0086] Fig. 2 is a schematic diagram of an example of a head-mounted display of the present invention. The head-mounted display 80 shown in Fig. 2 is, as an example, an AR glass, and includes a light guide plate 82, an incident diffraction element 90 and an exit diffraction element 92 arranged on one surface of the light guide plate 82, an optical filter 10, and an image display element 86. The light guide plate 82, the incident diffraction element 90 and the exit diffraction element 92, and the optical filter 10 constitute a polarizer 12 and an optical film 14 of the present invention.

[0087] 2, an incident diffraction element 90 is disposed on the surface (principal surface) on one end side of the light guide plate 82. An output diffraction element 92 is disposed on the surface on the other end side of the light guide plate 82. The position of the incident diffraction element 90 is determined by the angle at which the image light I from the image display element 86 to the light guide plate 82 is incident. １ On the other hand, the position of the output diffraction element 92 corresponds to the incident position of the image light I from the light guide plate 82. １ The exit position of the image light I １2 corresponds to the observation position of the light guide plate 82. The incident diffraction element 90 and the exit diffraction element 92 are disposed on the same surface of the light guide plate 82. The optical filter 10 is disposed on the surface of the light guide plate 82 opposite to the surface on which the exit diffraction element 92 is disposed, facing the exit diffraction element 92. As shown in FIG. 2, the optical filter 10 has a shape similar to that of the exit diffraction element 92. An intermediate diffraction element 94 may be provided on the light guide plate 82 (see FIG. 3). The positions of the diffraction elements are not limited to the ends of the light guide plate, and various positions can be used depending on the shape of the light guide plate, etc.

[0088] In the head-mounted display 80 (AR glasses) configured as described above, the image light I displayed by the image display element 86 is １ As shown by the arrow, the image light I is diffracted by the incident diffraction element 90 and enters the light guide plate 82 at an angle at which it is totally reflected at the interface between the light guide plate 82 and the air. １ is totally reflected by both surfaces of the light guide plate 82, is guided through the light guide plate 82, and is incident on the output diffraction element 92. １ is diffracted by the output diffraction element 92 in a direction perpendicular to the surface of the output diffraction element 92. １ is emitted to a viewing position outside the light guide plate 82 for viewing by the user. It is preferable to have an air gap between the optical filter 10 and the light guide plate 82. If there is no air gap, the image light I １ is incident on the optical filter 10, and the image light I １ However, when the image light I propagates through the optical filter 10, is totally reflected by the surface of the optical filter 10 opposite to the light guide plate 82, and then propagates again through the optical filter 10, it is attenuated by absorption. By providing an air gap between the optical filter 10 and the light guide plate 82, the image light I propagates from the light guide plate to the optical filter. １ is not incident, and the above problem can be solved

[0089] As shown in FIG. 2, external light I entering the head-mounted display 80 from the front direction ０That is, the background light passes through the optical filter 10, enters the light guide plate 82, passes through the output diffraction element 92, and reaches the observation position of the user. In the following description, external light that enters the head-mounted display 80 from the front direction is referred to as front external light I. ０ As a result, the head mounted display 80 causes the image displayed by the image display element 86 to enter one end of the light guide plate 82, propagate therethrough, and exit from the other end, thereby superimposing a virtual image on the view that the user is actually seeing.

[0090] The shape of the optical filter 10 is not limited to the same as the shape of the diffraction element, and may be different in shape and size. ｓ and the background, i.e., the front external light I ０ In order to prevent unnecessary light blocking, it is preferable that the diffraction element and the optical filter have the same shape, including the same size.

[0091] There are no particular limitations on the light guide plate 82, and any conventional light guide plate used in image display devices, etc., such as light guide plates used in various types of AR glasses and light guide plates used in backlight units of liquid crystal display devices, can be used.

[0092] There are no limitations on the image display element 86, and various known image display elements (displays) used in various image display devices such as AR glasses can be used. Examples of the image display element 86 include a liquid crystal display (including LCOS (Liquid Crystal On Silicon)), an organic electroluminescence display, an inorganic electroluminescence display, a DLP (Digital Light Processing), a MEMS (Micro-Electro-Mechanical Systems) display, and a micro LED (Light-Emitting Diode) display. Note that the image display element 86 may be one that displays monochrome images, two-color images, or color images.

[0093] The optical device of the present invention has an optical filter including the laminate of the present invention covering the diffraction element, preferably an optical filter including an optical film 14 and a polarizer 12 as in the illustrated example. By having such an optical filter 10 (10m), the optical device of the present invention can reduce the amount of light emitted from the front direction (front external light I) when used in a head-mounted display such as AR glasses. ０ ) has a high light transmittance, i.e., the visibility of the background is excellent, and external light (oblique external light I) incident from above the observer's head (diagonally above and in front of the observer's head) is also excellent. ｓ Furthermore, the optical device of the present invention can preferably suppress rainbow unevenness caused by external light incident not only from above and in front of the viewer's head, but also from diagonally ahead of the viewer's head (above and in a diagonal direction from above).

[0094] In the optical device of the present invention, the angle between the absorption axis (the alignment direction of the liquid crystal compound) of the optical film 14 constituting the optical filter 10 and the normal direction of the optical film 14 is 0 to 45°. That is, the optical film 14 has an absorption axis extending in the normal direction to the principal surface of the optical film 14 and the principal surface of the light guide plate 82. On the other hand, the polarizer 12 constituting the optical filter 10 is a polarizer having an absorption axis in the principal surface. That is, the polarizer has an absorption axis parallel to the principal surface of the optical film 14 and the principal surface of the light guide plate 82. Note that in the present invention, when the optical filter includes the optical film 14 and the polarizer 12, it is preferable to place the optical film 14 on the light guide plate 82 side from the viewpoint of improving light resistance.

[0095] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment details, and treatment procedures shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0096] Example 1 Preparation of Optical Film Temporary Support A cellulose acylate film 1 (TAC substrate having a thickness of 40 μm; TG40, manufactured by Fujifilm Corporation) was used as a temporary support after its surface was saponified with an alkaline solution.

[0097] <Preparation of Alignment Film> The following composition 1 for forming an alignment film was applied onto a cellulose acylate film 1. The support on which the coating film had been formed was dried for 120 seconds with hot air at 100°C to form an alignment film 1. The thickness of the alignment film 1 was 1.0 μm. ---------------------------------------------------------------- Composition 1 for forming an alignment film ---------------------------------------------------------------- Modified polyvinyl alcohol PVA-1 (shown below) 3.80 parts by mass Water 70 parts by mass Methanol 30 parts by mass

[0098] Modified polyvinyl alcohol PVA-1

[0099] <Preparation of Optically Absorbent Anisotropic Layer> The following composition for forming an optically absorbent anisotropic layer was applied to the obtained TAC film with an alignment layer using a wire bar, heated at 120°C for 60 seconds, and then cooled to 35°C. The layer was then heated at 75°C for 60 seconds and cooled again to room temperature. Thereafter, under nitrogen purging conditions (oxygen concentration 100 ppm or less), an LED (Light Emitting Diode) lamp (center wavelength 365 nm) was used to illuminate the layer from the direction normal to the film at an illuminance of 200 mW / cm. ２ The optically absorptive anisotropic layer was formed on the alignment film by irradiating the film with light for 2 seconds under the irradiation conditions of 1. The thickness of the optically absorptive anisotropic layer was 4.5 μm.

[0100] 0.16 parts by mass of alignment agent E-1 below; 0.16 parts by mass of alignment agent E-2 below; 0.007 parts by mass of surfactant F-1 below; 78.17 parts by mass of cyclopentanone; 8.69 parts by mass of benzyl alcohol ------------------------------------------------

[0101] Dichroic substance D-1

[0102] Dichroic substance D-2

[0103] Dichroic substance D-3

[0104] Polymer liquid crystal compound P-1

[0105] Liquid crystal compound L-1 (a mixture of the following liquid crystal compounds (RA), (RB), and (RC) in a mass ratio of 84:14:2)

[0106] Orientation agent E-1

[0107] Orientation agent E-2

[0108] Surfactant F-1 (In the formula below, the numerical value of each repeating unit represents the content (% by mass) of each repeating unit. In addition, in the formula below, repeating unit A corresponds to the hydrophobic portion, and repeating unit B corresponds to the hydrophilic portion. In addition, in the formula below, repeating unit C corresponds to a monomer whose molecular weight is 1,000 or more.)

[0109] <Preparation of Protective Layer> The following protective layer-forming composition was applied to the surface of the obtained light absorption anisotropic layer using a wire bar to form a coating film. The support on which the coating film had been formed was then dried with hot air at 60°C for 60 seconds and then with hot air at 100°C for 120 seconds to form a protective layer. Thereafter, under nitrogen purging conditions (oxygen concentration 100 ppm or less), an LED lamp (center wavelength 365 nm) was used to illuminate the film normal direction at an illuminance of 200 mW / cm. ２ A protective layer was formed by irradiating the film for 2 seconds under the irradiation conditions of 1.5 μm to 1.7 μm, and a laminate was produced. The protective layer had a thickness of 0.5 μm. Optical film 1 was produced by the above-mentioned operations.

[0110] Protective layer-forming composition 1 ------------------------------------------------ 3.80 parts by mass of modified polyvinyl alcohol PVA-1 shown below 0.20 parts by mass IRGACURE 2959 (manufactured by BASF) 0.08 parts by mass of dye compound G-1 shown below 70 parts by mass of water 30 parts by mass of methanol

[0111] Modified polyvinyl alcohol PVA-1 (in the formula below, the numbers indicate the content (% by mass) of each repeating unit relative to the total repeating units.) (Degree of polymerization: 1700)

[0112] Dye compound G-1

[0113] Example 2 An optical film of Example 2 was produced in the same manner as in Example 1, except that the composition 1 for forming an optically absorptive anisotropic layer was changed to the composition 2 for forming an optically absorptive anisotropic layer described below. 0.16 parts by mass of the alignment agent E-1; 0.16 parts by mass of the alignment agent E-2; 0.007 parts by mass of the following surfactant F-2; 78.17 parts by mass of cyclopentanone; 8.69 parts by mass of benzyl alcohol.

[0114] Surfactant F-2 (In the formula below, the numerical value of each repeating unit represents the content (% by mass) of each repeating unit. In addition, in the formula below, repeating unit A corresponds to the hydrophobic portion, and repeating unit B corresponds to the hydrophilic portion. In addition, in the formula below, repeating unit C corresponds to a monomer whose molecular weight is 1,000 or more.)

[0115] Example 3 An optical film of Example 3 was produced in the same manner as in Example 1, except that the composition 1 for forming an optically absorptive anisotropic layer was changed to the composition 3 for forming an optically absorptive anisotropic layer described below. 0.16 parts by mass of the alignment agent E-1; 0.16 parts by mass of the alignment agent E-2; 0.007 parts by mass of the following surfactant F-3; 78.17 parts by mass of cyclopentanone; 8.69 parts by mass of benzyl alcohol.

[0116] Surfactant F-3 (In the formula below, the numerical value of each repeating unit represents the content (% by mass) of each repeating unit. In addition, in the formula below, repeating unit A corresponds to the hydrophobic portion, and repeating unit C corresponds to the hydrophilic portion. In addition, in the formula below, repeating unit B corresponds to a monomer whose molecular weight is 1,000 or more.)

[0117] Example 4 An optical film of Example 4 was produced in the same manner as in Example 1, except that the composition 1 for forming an optically absorptive anisotropic layer was changed to the composition 4 for forming an optically absorptive anisotropic layer described below. 0.16 parts by mass of the alignment agent E-1; 0.16 parts by mass of the alignment agent E-2; 0.007 parts by mass of the surfactant F-4 below; 78.17 parts by mass of cyclopentanone; 8.69 parts by mass of benzyl alcohol.

[0118] Surfactant F-4 (In the formula below, the numerical value of each repeating unit represents the content (% by mass) of each repeating unit. In addition, in the formula below, repeating unit A corresponds to the hydrophobic portion, and repeating unit B corresponds to the hydrophilic portion. In addition, in the formula below, repeating unit C corresponds to a monomer whose molecular weight is 1,000 or more.)

[0119] Example 5 An optical film of Example 5 was produced in the same manner as in Example 1, except that the composition 1 for forming an optically absorptive anisotropic layer was changed to the composition 5 for forming an optically absorptive anisotropic layer described below. 0.16 parts by mass of the alignment agent E-1; 0.16 parts by mass of the alignment agent E-2; 0.007 parts by mass of the surfactant F-5 described below; 78.17 parts by mass of cyclopentanone; 8.69 parts by mass of benzyl alcohol.

[0120] Surfactant F-5 (In the formula below, the numerical value of each repeating unit represents the content (% by mass) of each repeating unit. In addition, in the formula below, repeating unit A corresponds to the hydrophobic portion, and repeating unit B corresponds to the hydrophilic portion. In addition, in the formula below, repeating unit C corresponds to a monomer whose molecular weight is 1,000 or more.)

[0121] Example 6 An optical film of Example 6 was produced in the same manner as in Example 1, except that the composition 1 for forming an optically absorptive anisotropic layer was changed to the composition 6 for forming an optically absorptive anisotropic layer described below. 0.16 parts by mass of the alignment agent E-1; 0.16 parts by mass of the alignment agent E-2; 0.007 parts by mass of the surfactant F-6 below; 78.17 parts by mass of cyclopentanone; 8.69 parts by mass of benzyl alcohol.

[0122] Surfactant F-6 (In the formula below, the numerical value of each repeating unit represents the content (% by mass) of each repeating unit. In addition, in the formula below, repeating unit A corresponds to the hydrophobic portion, and repeating unit B corresponds to the hydrophilic portion. In addition, in the formula below, repeating unit C corresponds to a monomer whose molecular weight is 1,000 or more.)

[0123] Example 7 An optical film of Example 7 was produced in the same manner as in Example 1, except that the composition 1 for forming an optically absorptive anisotropic layer was changed to the composition 7 for forming an optically absorptive anisotropic layer described below. 0.16 parts by mass of the alignment agent E-1; 0.16 parts by mass of the alignment agent E-2; 0.007 parts by mass of the surfactant F-7 below; 78.17 parts by mass of cyclopentanone; 8.69 parts by mass of benzyl alcohol.

[0124] Surfactant F-7 (In the formula below, the numerical value of each repeating unit represents the content (% by mass) of each repeating unit. In addition, in the formula below, repeating unit A corresponds to the hydrophobic portion, and repeating unit B corresponds to the hydrophilic portion. In addition, in the formula below, repeating unit C corresponds to a monomer whose molecular weight is 1,000 or more.)

[0125] [Example 8] An optical film of Example 8 was produced in the same manner as in Example 1, except that the optically absorptive anisotropic layer-forming composition 1 and the protective layer-forming composition 1 were changed to the optically absorptive anisotropic layer-forming composition 8 and the protective layer-forming composition 2 described below, respectively. 0.05 parts by mass of the alignment agent E-1; 0.28 parts by mass of the alignment agent E-3 described below; 0.008 parts by mass of the surfactant F-7; 82.11 parts by mass of cyclopentanone; 9.12 parts by mass of benzyl alcohol.

[0126] Orientation agent E-3

[0127] -------------------------------------------------- Protective layer-forming composition 2 -------------------------------------------------- 3.19 parts by mass of the above-mentioned modified polyvinyl alcohol PVA-1, 0.17 parts by mass of IRGACURE 2959 (manufactured by BASF), 0.02 parts by mass of BYK 348 (manufactured by BYK), 2.26 parts by mass of the following mixed solution 1, 70 parts by mass of water, 30 parts by mass of methanol ------------------------------------------------------------------ Note that the following mixed solution 1 was heated and stirred at 40°C for 4 hours, and then added to the above-mentioned modified polyvinyl alcohol PVA-1, etc., to prepare protective layer-forming composition 2.

[0128] ------------------------------------------------------------------ Mixture 1 -------------------------------------------------- 2,5-Dimethoxytetrahydrofuran 0.80 parts by mass, pyridinium paratoluenesulfonate 0.24 parts by mass, water 8.96 parts by mass ------------------------------------------------------------------

[0129] Comparative Example 1 An optical film of Comparative Example 1 was produced in the same manner as in Example 1, except that the composition 1 for forming an optically absorptive anisotropic layer was changed to the composition 7 for forming an optically absorptive anisotropic layer described below. 0.16 parts by mass of the alignment agent E-1; 0.16 parts by mass of the alignment agent E-2; 0.007 parts by mass of the surfactant F-8 described below; 78.17 parts by mass of cyclopentanone; 8.69 parts by mass of benzyl alcohol.

[0130] Surfactant F-8 (In the formula below, the numerical value of each repeating unit represents the content (% by mass) of each repeating unit. In addition, in the formula below, repeating unit A corresponds to the hydrophobic portion, and repeating unit B corresponds to the hydrophilic portion.)

[0131] Comparative Example 2 An optical film of Comparative Example 2 was produced in the same manner as in Example 1, except that the composition 1 for forming an optically absorptive anisotropic layer was changed to the composition 8 for forming an optically absorptive anisotropic layer described below. 0.16 parts by mass of the alignment agent E-1; 0.16 parts by mass of the alignment agent E-2; 0.007 parts by mass of the surfactant F-9 below; 78.17 parts by mass of cyclopentanone; 8.69 parts by mass of benzyl alcohol.

[0132] Surfactant F-9 (In the formula below, the numerical value of each repeating unit represents the content (% by mass) of each repeating unit. In addition, in the formula below, repeating unit A corresponds to the hydrophobic portion, and repeating unit B corresponds to the hydrophilic portion. In addition, in the formula below, repeating unit C corresponds to a monomer whose molecular weight is 1,000 or more.)

[0133] Comparative Example 3 An optical film of Comparative Example 3 was produced in the same manner as in Example 1, except that the composition 1 for forming an optically absorptive anisotropic layer was changed to the composition 9 for forming an optically absorptive anisotropic layer described below. 0.16 parts by mass of the alignment agent E-1; 0.16 parts by mass of the alignment agent E-2; 0.007 parts by mass of the surfactant F-10 shown below; 78.17 parts by mass of cyclopentanone; 8.69 parts by mass of benzyl alcohol.

[0134] Surfactant F-10 (In the formula below, the numerical value of each repeating unit represents the content (% by mass) of each repeating unit. In addition, in the formula below, repeating unit A corresponds to the hydrophobic portion, and repeating unit B corresponds to the hydrophilic portion. In addition, in the formula below, repeating unit C corresponds to a monomer whose molecular weight is 1,000 or more.)

[0135] Comparative Example 4 An optical film of Comparative Example 4 was produced in the same manner as in Example 1, except that the composition 1 for forming an optically absorptive anisotropic layer was changed to the composition 10 for forming an optically absorptive anisotropic layer described below. 0.16 parts by mass of the alignment agent E-1; 0.16 parts by mass of the alignment agent E-2; 0.007 parts by mass of the surfactant F-11 described below; 78.17 parts by mass of cyclopentanone; 8.69 parts by mass of benzyl alcohol.

[0136] Surfactant F-11 (In the formula below, the numerical value of each repeating unit represents the content (% by mass) of each repeating unit. In addition, in the formula below, the top and middle repeating units correspond to the hydrophobic portion, and the bottom repeating unit corresponds to the hydrophilic portion.)

[0137] [Comparative Example 5] An optical film of Comparative Example 5 was produced in the same manner as in Comparative Example 4, except that the surface of the optically absorptive anisotropic layer was subjected to a corona treatment under the following conditions before coating the protective layer. <Conditions for corona treatment> The surface of the optically absorptive anisotropic layer 1 was subjected to a corona treatment under conditions of 4.0 m / min, 440 W, and a clearance of 2.0 mm.

[0138] [Evaluation] The transmittance central axis angle θ of the light absorption anisotropic layer of the produced optical film was measured by the method described above, and was found to be 0° in all cases.

[0139] (1) Repelling during protective layer formation After the protective layer-forming composition was applied to the light-absorption anisotropic layer, the sample was visually inspected and evaluated according to the following criteria. The results are shown in Table 1 below. <Criteria> C: Repelling was observed on the front surface. B: Minor repelling was observed in some areas, but not in most areas. A: No repelling occurred.

[0140] (2) Adhesion: 11 cuts were made in each of the vertical and horizontal directions on the prepared optical film from the protective layer side down to the alignment film, creating 100 grids (squares). A cutter guide was used, and the cuts were spaced 1 mm apart. Cellotape CT-24 (registered trademark) (manufactured by Nichiban Co., Ltd.) was firmly pressed onto the squares, and the edge of the tape was quickly peeled off at a 45° angle. Film peeling was visually observed and evaluated according to the following criteria. The results are shown in Table 1 below. <Criteria> D: 10 or more squares where peeling occurred C: 3 to 9 squares where peeling occurred B: 1 to 2 squares where peeling occurred A: 0 squares where peeling occurred

[0141] (3) Coating Surface Condition (Unevenness in Optically Absorbent Anisotropic Layer) The surface condition of the optically absorbent anisotropic layer was visually observed and evaluated according to the following criteria. The results are shown in Table 1 below. <Criteria> C: Unevenness visible to the naked eye is noticeable B: Unevenness visible to the naked eye is not so noticeable A: Unevenness is barely visible to the naked eye

[0142]

[0143] In Table 1 above, AA, MAA, NIPAM, AA-GMA, ACMO, MPC, and HEAA respectively represent the following abbreviations: AA: acrylic acid MAA: methacrylic acid NIPAM: N-isopropylacrylamide AA-GMA: glycidyl methacrylate adduct to acrylic acid ACMO: acryloylmorpholine MPC: 2-methacryloyloxyethylphosphorylcholine HEAA: N-(2-hydroxyethyl)acrylamide

[0144] The results shown in Table 1 indicate that when the peak intensity of the ion fragments derived from the hydrophobic moiety detected by TOF-SIMS does not satisfy one or more of the above formulas (1) to (3), the adhesion between the optically absorbing anisotropic layer and the protective layer is poor unless corona treatment is performed (Comparative Examples 1 to 5). In contrast, when the peak intensity of the ion fragments derived from the hydrophobic moiety detected by TOF-SIMS satisfies all of the above formulas (1) to (3), the adhesion between the optically absorbing anisotropic layer and the protective layer is good even without corona treatment (Examples 1 to 8). Furthermore, comparison of Example 1 with Examples 4 and 6 to 8 indicates that the adhesion between the optically absorbing anisotropic layer and the protective layer is better when the hydrophilic moiety having a ClogP value of 1.0 or less is a repeating unit corresponding to at least one monomer selected from the group consisting of methacrylic acid, N-(2-hydroxyethyl)acrylamide, and 2-methacryloyloxyethylphosphorylcholine.

[0145] REFERENCE SIGNS LIST 1 optically absorptive anisotropic layer 2 protective layer X surface Y interface Z center position Z in film thickness direction between interface X and interface Y 10 optical filter 12 polarizer 14 optical film 80 head-mounted display 82 light guide plate 90 incident diffraction element 92 output diffraction element 94 intermediate diffraction element I ０ Front external light I １ Video Light I ｓ Oblique external light

Claims

1. A light-absorbing anisotropic layer containing a surfactant, a dichroic material, and a liquid crystal compound, and a protective layer provided adjacent to the light-absorbing anisotropic layer, wherein the angle θ between the transmittance central axis of the light-absorbing anisotropic layer and the normal direction to the surface of the light-absorbing anisotropic layer is 0° or more and 45° or less, the surfactant has both a hydrophobic moiety with a ClogP value of 3.5 or more and a hydrophilic moiety with a ClogP value of 1.0 or less and a molecular weight of less than 1,000, and both the hydrophobic moiety and the hydrophilic moiety are present on a surface X of the protective layer opposite to the light-absorbing anisotropic layer, and on an interface Y between the light-absorbing anisotropic layer and the protective layer, An optical film, wherein when secondary ion intensity is measured by time-of-flight secondary ion mass spectrometry while irradiating an ion beam from the surface X toward the interface Y, peak intensities of ion fragments derived from the hydrophobic portion detected at the surface X, the interface Y, and a central position Z in the film thickness direction between the interface X and the interface Y are Ix, Iy, and Iz, respectively, the optical film satisfies all of the following formulas (1) to (3): Formula (1) Ix / Iz≧2 Formula (2) Iy / Iz≧2 Formula (3) 0.05≦Ix / Iy≦1.5 2. The optical film according to claim 1, wherein the hydrophobic portion is a repeating unit having a siloxane bond in a side chain.

3. The optical film according to claim 1 or 2, wherein the hydrophobic moieties present on the surface X and the interface Y have the same partial structure, and the hydrophilic moieties present on the surface X and the interface Y have the same partial structure.

4. When the secondary ion intensity is measured by time-of-flight secondary ion mass spectrometry while irradiating an ion beam from the surface X toward the interface Y, the ion fragments derived from the hydrophobic portion are detected as Si ３ C ５ H １５ O ３ ＋ The optical film according to claim 1 or 2, 5. The optical film according to claim 1 or 2, wherein the hydrophilic portion is a repeating unit corresponding to at least one monomer selected from the group consisting of methacrylic acid, N-(2-hydroxyethyl)acrylamide, and 2-methacryloyloxyethylphosphorylcholine.

6. The optical film according to claim 1 or 2, wherein, when secondary ion intensity is measured by time-of-flight secondary ion mass spectrometry while irradiating an ion beam from the surface X toward the interface Y, the ratio of the peak intensity of ion fragments derived from the hydrophilic portion detected at the interface Y to the peak intensity of ion fragments derived from the hydrophobic portion is 0.2 to 0.5.

Images