Light absorption anisotropic film, laminate, composite lens, goggle type display device, and method for manufacturing light absorption anisotropic film

Abstract

The present invention addresses the problem of providing a light absorption anisotropic film excellent in crack resistance and having a curved surface part. The light absorption anisotropic film according to the present invention is a light absorption anisotropic film having a curved surface part, wherein the haze on the transmission axis side calculated from formula (1) is 0.40% or less.　Formula (1): (1-T2 / T1) × 100. In formula (1), T1 represents the transmittance on the transmission axis side measured using an integrating sphere for the light absorption anisotropic film, and T2 represents the transmittance on the transmission axis side measured without using an integrating sphere for the light absorption anisotropic film.

Description

Optically absorbing anisotropic film, laminate, composite lens, goggle-type display device, and method for manufacturing optically absorbing anisotropic film

[0001] The present invention relates to an optically absorptive anisotropic film, a laminate, a composite lens, a goggle-type display device, and a method for producing an optically absorptive anisotropic film.

[0002] In recent years, as the uses of polarizing plates have become more diverse, there has been a demand for providing polarizing plates on articles with curved surfaces rather than flat surfaces, depending on the application.

[0003] For example, Patent Document 1 describes a polarizing plate having a curved shape, which comprises, in this order, a curved substrate, a photo-alignment film, and a polarizer, wherein the polarizer is made of a cured product of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound having at least one polymerizable group and a dichroic dye, and the polymerizable liquid crystal compound is oriented so that the absorption axis of the polarizer faces in one direction relative to the surface direction of the curved surface of the curved substrate on which the polarizer is laminated.

[0004] Furthermore, Patent Document 2 describes a "polarizing plate including a polarizer and a protective layer disposed on at least one of the polarizers, which is curved, and in which the breaking elongation E per unit thickness of the polarizer is 0.25 (% / μm) or more."

[0005] JP 2021-135503 A JP 2022-75143 A

[0006] The present inventors have examined the polarizing plates described in Patent Documents 1 and 2 and have found that, depending on the shape of the curved surface portion, cracks may occur in the polarizer (optically absorptive anisotropic film), i.e., the polarizing plates may have poor crack resistance.

[0007] Therefore, an object of the present invention is to provide an optically absorptive anisotropic film having a curved surface portion and excellent crack resistance.An object of the present invention is also to provide a laminate, a composite lens, a goggle-type display device, and a method for manufacturing an optically absorptive anisotropic film.

[0008] As a result of intensive research aimed at achieving the above object, the present inventors have found that an optically absorptive anisotropic film having a haze of 0.40% or less on the transmission axis side has good crack resistance, and have completed the present invention. That is, the present inventors have found that the above object can be achieved by the following configuration.

[0009] [1] An optically absorptive anisotropic film having a curved surface portion, wherein the haze on the transmission axis side calculated from the following formula (1) is 0.40% or less: (1-T2 / T1) x 100 (1) where, in formula (1), T1 refers to the transmittance of the optically absorptive anisotropic film on the transmission axis side measured using an integrating sphere, and T2 refers to the transmittance of the optically absorptive anisotropic film on the transmission axis side measured without using an integrating sphere. [2] The optically absorptive anisotropic film according to [1], wherein the curved surface portion has a non-developable curved surface. [3] The optically absorptive anisotropic film according to [1] or [2], wherein the optically absorptive anisotropic film is a film obtained by fixing the alignment state of an optically absorptive anisotropic film-forming composition containing a liquid crystal compound and a dichroic substance. [4] The optically absorptive anisotropic film according to [3], wherein the optically absorptive anisotropic film-forming composition contains three or more liquid crystal compounds satisfying the following condition: Condition: The mass X of the liquid crystal compound having the largest content and the mass Y of the liquid crystal compound having the smallest content satisfy the following formula (2): X × 0.1 ≦ Y < X (2) [5] The optically absorptive anisotropic film according to [4], wherein the Log P values ​​of the three or more liquid crystal compounds are all 5 or less. [6] The optically absorptive anisotropic film according to [4] or [5], wherein the three or more liquid crystal compounds all have a biphenyl skeleton. [7] The optically absorptive anisotropic film according to any one of [4] to [6], wherein at least one of the three or more liquid crystal compounds is a polymeric liquid crystal compound. [8] The optically absorptive anisotropic film according to any one of [1] to [7], wherein the thickness of the optically absorptive anisotropic film is 8 μm or less. [9] A laminate comprising the optically absorptive anisotropic film according to any one of [1] to [8].

[10] The laminate according to [9], comprising an optically absorptive anisotropic film, a retardation layer, and a reflective polarizer layer.

[11] A compound lens having the laminate according to [9] or

[10] , a lens, and a half mirror in this order.

[12] A goggle-type display device having the laminate according to [9] or

[10] .

[13] A method for producing the optically absorbing anisotropic film according to [1], comprising: a coating film formation step of applying a composition for forming an optically absorbing anisotropic film, the composition containing a liquid crystal compound and a dichroic substance, to form a coating film; and an alignment step of subjecting the coating film to a heat treatment of heating the coating film to a temperature above 70°C and not lower than the melting point of the liquid crystal compound, and a cooling treatment of cooling the coating film to less than 40°C after the heat treatment, wherein the time required for cooling from 70°C to 40°C in the cooling treatment is 2 seconds or less.

[14] A method for producing the optically absorbing anisotropic film according to [1], comprising: an underwater stretching step of stretching a polyvinyl alcohol-based resin layer in water, wherein the temperature in the underwater stretching step is 90°C or higher.

[0010] According to the present invention, it is possible to provide an optically absorptive anisotropic film having a curved surface portion and excellent crack resistance. According to the present invention, it is possible to provide a laminate, a composite lens, a goggle-type display device, and a method for manufacturing an optically absorptive anisotropic film.

[0011] FIG. 1 is a top view showing an example of an optically absorptive anisotropic film of the present invention. FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 3 is a diagram illustrating the procedure for molding a film using a mold having a concave molding surface. FIG. 4 is a diagram illustrating the procedure for molding a film using a mold having a concave molding surface. FIG. 5 is a top view of a film used for molding. FIG. 6 is a diagram illustrating the procedure for molding a film using a mold having a convex molding surface. FIG. 7 is a diagram illustrating the procedure for molding a film using a mold having a convex molding surface. FIG. 8 is a cross-sectional view showing an example of a laminate of the present invention. FIG. 9 is a cross-sectional view showing another example of a laminate of the present invention. FIG. 10 is a cross-sectional view showing an example of a composite lens of the present invention. FIG. 11 is a diagram illustrating an example of a goggle-type display device of the present invention, showing an example of light rays of a main image.

[0012] The present invention will be described in detail below. The following description of the constituent elements may be based on representative embodiments and specific examples, but the present invention is not limited to such embodiments. 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 stages may be replaced with the upper or lower limit of another numerical range described in stages. In this specification, the upper or lower limit of a numerical range described in stages 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 this specification, "(meth)acrylic" refers to "acrylic" or "methacrylic."

[0013] In this specification, the term "transmittance" refers to the average transmittance in the wavelength range of 380 to 780 nm.

[0014] In this specification, "absorption axis" refers to the polarization direction in which absorbance is maximized in a plane when linearly polarized light is incident. "Reflection axis" refers to the polarization direction in which reflectance is maximized in a plane when linearly polarized light is incident. "Transmission axis" refers to the direction perpendicular to the absorption axis or reflection axis in a plane. "Slow axis" refers to the direction in which refractive index is maximized in a plane.

[0015] In this specification, Re(λ) and Rth(λ) represent the in-plane retardation and the thickness retardation, respectively, at a wavelength λ. Unless otherwise specified, the wavelength λ is 550 nm. In the present invention, Re(λ) and Rth(λ) are values ​​measured at a wavelength λ using an AxoScan (manufactured by Axometrics). By inputting the average refractive index ((nx + ny + nz) / 3) and film thickness (d) into AxoScan, the following slow axis direction (°) is calculated: Re(λ) = R0(λ) Rth(λ) = ((nx + ny) / 2 - nz) × d. Note that R0(λ) is displayed as a numerical value calculated by AxoScan, but it means Re(λ).

[0016] In this specification, the refractive indices nx, ny, and nz are measured using an Abbe refractometer (NAR-4T, manufactured by Atago Co., Ltd.) with a sodium lamp (λ = 589 nm) as a light source. When measuring wavelength dependency, measurements can be made using a multi-wavelength Abbe refractometer DR-M2 (manufactured by Atago Co., Ltd.) in combination with an interference filter. Values ​​from the Polymer Handbook (John Wiley & Sons, Inc.) and catalogs of various optical films can also be used. Examples of average refractive index values ​​for major optical films are listed below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59).

[0017] In this specification, A plates and C plates are defined as follows. There are two types of A plates: positive A plates (positive A plates) and negative A plates (negative A plates). When the refractive index in the in-plane slow axis direction (the direction in which the in-plane refractive index is maximum) of the film is nx, the refractive index in the in-plane direction perpendicular to the in-plane slow axis is ny, and the refractive index in the thickness direction is nz, the positive A plates satisfy the relationship of formula (A1), and the negative A plates satisfy the relationship of formula (A2). Note that the positive A plates have a positive Rth value, and the negative A plates have a negative Rth value. Formula (A1) nx>ny≒nz Formula (A2) ny<nx≒nz Note that the above "≒" includes not only the case where the two are completely identical, but also the case where the two are substantially identical. "Substantially the same" means, for example, that "ny ≒ nz" also includes cases where (ny - nz) x d (where d is the film thickness) is -10 to 10 nm, preferably -5 to 5 nm, and "nx ≒ nz" also includes cases where (nx - nz) x d is -10 to 10 nm, preferably -5 to 5 nm. There are two types of C plates: positive C plates (positive C plates) and negative C plates (negative C plates). Positive C plates satisfy the relationship of formula (C1), while negative C plates satisfy the relationship of formula (C2). Note that positive C plates have a negative Rth value, and negative C plates have a positive Rth value. Formula (C1) nz > nx ≒ ny Formula (C2) nz < nx ≒ ny Note that the above "≒" includes not only cases where the two are completely identical, but also cases where the two are substantially identical. The term "substantially the same" includes, for example, the case where (nx-ny) x d (where d is the thickness of the film) is 0 to 10 nm, preferably 0 to 5 nm, in "nx≈ny".

[0018] [Light-absorption anisotropic film] The light-absorption anisotropic film of the present invention has a curved surface portion, and the haze on the transmission axis side calculated from the formula (1) described below is 0.40% or less. Furthermore, the light-absorption anisotropic film of the present invention is a film having absorption anisotropy, and it is preferable that the absorption anisotropy is in the in-plane direction of the light-absorption anisotropic film. In particular, it is preferable that the light-absorption anisotropic film functions as an absorbing linear polarizer.

[0019] As described above, the optically absorptive anisotropic film of the present invention has a haze of 0.40% or less on the transmission axis side, calculated using the formula (1) described below, and therefore exhibits good crack resistance. The mechanism behind this is unclear, but is presumed to be roughly as follows. First, the inventors discovered that appropriately changing the materials and preparation procedures of the optically absorptive anisotropic film significantly changes the haze on the transmission axis side of the film, and demonstrated that this is related to crack resistance. The inventors further discovered that when the haze on the transmission axis side of the optically absorptive anisotropic film is 0.40% or less, fewer crystalline portions (e.g., liquid crystal compounds or polyvinyl alcohol-based resins oriented and partially crystallized) may be present on the transmission axis side. As a result, the boundary between the amorphous portion (i.e., matrix) and the crystalline portion on the transmission axis side, i.e., the portion where stress concentrates and cracks occur, is reduced, which is thought to result in good crack resistance.

[0020] [Curved Surface Portion] The optically absorptive anisotropic film of the present invention has a curved surface portion. Here, the term "curved surface portion" refers to a portion having a curved shape. The term "curved surface shape" refers to a shape having a curvature greater than zero, and includes a developable curved surface shape and a three-dimensional curved surface shape. The radius of curvature of a shape having a curvature is preferably 10 mm to 120 mm, more preferably 15 to 90 mm. A developable surface refers to a surface that can be developed into a plane without expanding or contracting each part of the surface. Examples of developable curved surfaces include surfaces corresponding to the circumferential surfaces of a cylinder, an elliptical cylinder, a cone, and an elliptical cone, and may be either a convex or concave curved surface. A three-dimensional curved surface refers to a curved surface that cannot be formed by deformation of a plane, i.e., a curved surface that is not developable. Examples of three-dimensional curved surfaces include surfaces corresponding to a sphere or a spheroid, and surfaces corresponding to a curved surface whose cross section is a parabola or hyperbola (e.g., a paraboloid of revolution), and may be either a convex or concave curved surface.

[0021] In the present invention, the curved surface portion preferably has a curved surface that is not a developable surface, because this makes the effect of improving crack resistance more apparent.

[0022] In the present invention, the curved surface shape of the curved surface portion is preferably a lens shape. Examples of the lens shape include a spherical shape and a spheroidal shape, and the shape may be a convex lens shape or a concave lens shape.

[0023] FIG. 1 shows an example of an optically absorptive anisotropic film of the present invention. FIG. 1 is a top view of the optically absorptive anisotropic film, and FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1. As shown in FIGS. 1 and 2, the optically absorptive anisotropic film 10 has a curved shape. More specifically, as shown in FIG. 2, the optically absorptive anisotropic film 10 has a shape (convex shape) that is convexly curved toward the upper side of the paper. In other words, the optically absorptive anisotropic film 10 has a convex shape that protrudes toward one surface. It can also be said that the optically absorptive anisotropic film 10 has a concave shape that is concave toward the other surface. While FIG. 1 shows an embodiment in which the shape of the optically absorptive anisotropic film when viewed in plan is pentagonal, the present invention is not limited to this embodiment, and the shape of the optically absorptive anisotropic film when viewed in plan may be rectangular, circular, or another shape.

[0024] [Haze and Transmittance] The optically absorptive anisotropic film of the present invention has a haze on the transmission axis side of 0.40% or less, calculated from the following formula (1): (1-T2 / T1) x 100 (1) In the formula (1), T1 refers to the transmittance on the transmission axis side of the optically absorptive anisotropic film measured using an integrating sphere, and T2 refers to the transmittance on the transmission axis side of the optically absorptive anisotropic film measured without using an integrating sphere. The transmittance is measured by the following method.

[0025] <Method for Measuring Transmittance> The transmittance is measured using the following procedure. First, a 2 cm square sample is cut from a curved optically absorptive anisotropic film and attached to a flat glass substrate to prepare a sample. The sample may also contain other layers that have been found not to affect the haze on the transmittance side. Next, using a polarizing film measuring device (e.g., the VAP-7070 automatic polarizing film measuring device manufactured by JASCO Corporation), the transmission axis is determined using the following procedure for both cases with and without an integrating sphere installed. The average transmittance on the transmission axis side in the wavelength range of 380 to 780 nm is measured and used as the transmittance on the transmission axis side. (Procedure) The sample is rotated ±7.5 degrees (in 2.5-degree increments) around the set angle, and measurement light is incident at an angle perpendicular to the sample surface at each angle, and the absorbance at 610 nm is measured. The absorbance is fitted using a quadratic approximation equation to make a first-order prediction of the angle at which the absorbance is maximized. The sample is rotated ±1.8 degrees (in 0.6 degree steps) around the primary predicted angle, and measurement light is incident at an angle perpendicular to the sample surface at each angle to measure absorbance at 610 nm. The angle at which the absorbance is maximized is predicted secondary, and this angle is set as the absorption axis. The angle rotated 90 degrees from the absorption axis is set as the transmission axis.

[0026] In the present invention, the haze on the transmission axis side calculated from the above formula (1) is preferably 0.35% or less, more preferably 0.30% or less, and even more preferably 0.25% or less, because this improves crack resistance. Furthermore, the lower limit of the haze on the transmission axis side calculated from the above formula (1) is not particularly limited, but is preferably 0.01% or more, more preferably 0.05% or more, and even more preferably 0.10% or more.

[0027] The thickness (average film thickness) of the optically absorptive anisotropic film is not particularly limited, but from the viewpoint of thinning the device, it is preferably 8 μm or less, more preferably 0.3 to 5.0 μm, and even more preferably 0.5 to 3.0 μm.

[0028] [Composition for forming an optically absorptive anisotropic film] The optically absorptive anisotropic film of the present invention may be a conventionally known polarizer composed of a resin film (e.g., a polyvinyl alcohol (PVA)-based resin film) containing a dichroic substance (e.g., iodine, a dichroic dye, or the like, which are components of the composition for forming an optically absorptive anisotropic film described below). However, in order to obtain better crack resistance, it is preferable that the film be formed by fixing the orientation state of a composition for forming an optically absorptive anisotropic film containing a liquid crystal compound and a dichroic substance. Hereinafter, the components contained in the composition for forming an optically absorptive anisotropic film will be described in detail.

[0029] <Liquid Crystal Compound> The optically absorptive anisotropic film-forming 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 the polymer liquid crystal compound being preferred due to its ability to achieve a higher degree of orientation. Furthermore, the liquid crystal compound may be a combination of a polymer liquid crystal compound and a low molecular weight liquid crystal compound. Here, "polymer liquid crystal compound" refers to a liquid crystal compound having a repeating unit in its chemical structure. Furthermore, "low molecular weight liquid crystal compound" refers to a liquid crystal compound having no repeating unit 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. It should be noted that the liquid crystal compound is preferably a liquid crystal compound that does not exhibit dichroism in the visible light region.

[0030] The optically absorptive anisotropic film-forming composition may contain one or two liquid crystal compounds. However, because this makes it easier to adjust the haze on the transmittance side of the optically absorptive anisotropic film to 0.40% or less, it preferably contains three or more liquid crystal compounds that satisfy the following condition. Condition: The mass X of the liquid crystal compound with the largest content and the mass Y of the liquid crystal compound with the smallest content satisfy the following formula (2): X × 0.1 ≦ Y < X (2). In the present invention, the above condition is satisfied when the contents (mass) of three or more liquid crystal compounds are the same and represent the maximum values. Furthermore, when the contents (mass) of three or more liquid crystal compounds are the same and represent the minimum values, the above condition is satisfied when the mass of any one liquid crystal compound is designated Y and a liquid crystal compound with a mass X that satisfies the above formula (2) is further contained. Furthermore, when the contents (mass) of two liquid crystal compounds are the same and represent the maximum values, the above condition is satisfied when the mass of any one liquid crystal compound is designated X and a liquid crystal compound with a mass Y that satisfies the above formula (2) is further contained. Furthermore, when the contents (mass) of two types of liquid crystal compounds are the same and are the minimum value, the mass of any one of the liquid crystal compounds is defined as Y, and when the composition further contains a liquid crystal compound having a mass X that satisfies the above formula (2), the composition is deemed to satisfy the above condition.

[0031] In the present invention, the Log P values ​​of the three or more liquid crystal compounds that satisfy the above conditions are preferably 5 or less, because this makes it easier to adjust the haze on the transmittance side of the optically absorptive anisotropic film to 0.40% or less and improves crack resistance. Here, the log P value is an index that expresses the hydrophilic and hydrophobic properties of a chemical structure and is sometimes called the hydrophilic-hydrophobic parameter. The log P value can be calculated using software such as ChemBioDraw Ultra or HSPiP (Ver. 4.1.07). It can also be experimentally determined using the method of OECD Guidelines for the Testing of Chemicals, Section 1, Test No. 117, etc. In the present invention, unless otherwise specified, the value calculated by inputting the structural formula of the compound into HSPiP (Ver. 4.1.07) is used as the log P value.

[0032] In the present invention, it is preferable that the three or more liquid crystal compounds satisfying the above conditions all have a biphenyl skeleton, because this makes it easier to adjust the haze on the transmittance side of the optically absorptive anisotropic film to 0.40% or less. Here, the biphenyl skeleton refers to a skeleton formed by two single-bonded phenyl groups (Ph), such as a biphenyldiyl group (-Ph-Ph-).

[0033] Furthermore, in the present invention, it is preferable that at least one of the three or more liquid crystal compounds satisfying the above conditions is a polymer liquid crystal compound, since this makes it easier to adjust the haze on the transmittance side of the optically absorptive anisotropic film to 0.40% or less.

[0034] 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. When two or more liquid crystal compounds are contained, the content of the liquid crystal compound refers to the total content of the liquid crystal compounds.

[0035] <Dichroic Substance> The optically absorptive anisotropic film-forming composition contains a dichroic substance. Here, the dichroic substance refers to a dye whose absorbance varies depending on the direction. The dichroic substance may or may not exhibit liquid crystallinity.

[0036] The dichroic substance is not particularly limited, and examples thereof include iodine, 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 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.

[0037] 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.

[0038] 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.

[0039] In the present invention, the dichroic substance preferably has a crosslinkable group, such as a cationically polymerizable group such as an epoxy group, an epoxycyclohexyl group, or an oxetanyl group; or a radically polymerizable group such as an acryloyl group, a methacryloyl group, a vinyl group, a styryl group, or an allyl group.

[0040] The content of the dichroic substance 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, based on the total mass of the solid content of the composition for forming an optically absorptive anisotropic film, because this increases the degree of orientation of the optically absorptive anisotropic film that is formed. When multiple dichroic substances are used in combination, the total amount of the multiple dichroic substances is preferably within the above-mentioned range. Furthermore, the content of the dichroic substance is preferably 20 to 650 mg / cm, because this increases the degree of orientation of the optically absorptive anisotropic film 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 ) can be obtained by measuring a solution in which a laminate having an optically absorptive anisotropic film is dissolved, or an extract obtained by immersing the laminate in a solvent, by high-performance liquid chromatography (HPLC), but the above method is not limited to this. Quantification can be performed by using the dichroic substance contained in the optically absorptive anisotropic film 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 film obtained from a microscopic image of the cross section of the laminate by the area of ​​the optical laminate used to measure the amount of dye, and then dividing the volume by the amount of dye measured by HPLC to calculate the dye content.

[0041] <Solvent> The optically absorptive anisotropic film-forming 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.

[0042] When the composition for forming an optically absorptive anisotropic film contains a solvent, the content of the solvent is preferably 60 to 99.5 mass %, more preferably 70 to 99 mass %, and particularly preferably 75 to 98 mass %, relative to the total mass (100 mass %) of the composition for forming an optically absorptive anisotropic film.

[0043] <Polymerization initiator> The optically absorptive anisotropic film-forming composition may contain a polymerization initiator. The polymerization initiator is not particularly limited, but is preferably a photosensitive compound, i.e., a photopolymerization initiator. As the photopolymerization initiator, various compounds can be used without particular limitation. Examples of photopolymerization initiators include α-carbonyl compounds (see U.S. Pat. Nos. 2,367,661 and 2,367,670), acyloin ethers (see U.S. Pat. No. 2,448,828), α-hydrocarbon-substituted aromatic acyloin compounds (see U.S. Pat. No. 2,722,512), polynuclear quinone compounds (see U.S. Pat. Nos. 3,046,127 and 2,951,758), and combinations of triarylimidazole dimers and p-aminophenyl ketones (see 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.

[0044] When the optically absorptive anisotropic film-forming composition contains a polymerization initiator, the content of the polymerization initiator is preferably 0.01 to 30 mass %, more preferably 0.1 to 15 mass %, based on the total solid mass of the optically absorptive anisotropic film-forming composition.

[0045] <Surfactant> The optically absorptive anisotropic film-forming composition preferably contains a surfactant. It is preferable to use a compound having a leveling function that flattens the coated film. For example, a silicon atom-containing compound, a polyacrylate compound, or a fluorine atom-containing compound can be used. In particular, from the viewpoint of reducing environmental pollution, the surfactant is preferably a silicon atom-containing compound or a polyacrylate compound, and a compound having a branched siloxane structure is preferred. The copolymer described in WO 2023 / 054164 is particularly preferred. The content of the surfactant in the optically absorptive anisotropic film is preferably 0.01% to 10%, more preferably 0.01% to 6.0%, and even more preferably 0.05% to 3.0%, relative to the total mass of the solids in the optically absorptive anisotropic film-forming composition (i.e., the mass of the optically absorptive anisotropic film).

[0046] <Other Components> In addition to the components described above, the optically absorptive anisotropic film-forming composition may contain an adhesion improver, a plasticizer, a polymer, etc. Here, examples of the adhesion improver include the reactive additives listed in paragraphs

[0123] to

[0129] of JP 2019-91088 A and the boronic acid monomers listed in paragraphs

[0015] to

[0028] of WO 2015 / 053359 A.

[0047] [Method for Producing Optically Absorbent Anisotropic Film] The method for producing the optically absorbing anisotropic film of the present invention is not particularly limited as long as it can produce an optically absorbing anisotropic film having the above-mentioned properties. For example, a method can be used in which a planar optically absorbing anisotropic film is produced by the methods described below in Production Methods A and B, and then the planar optically absorbing anisotropic film is molded to produce an optically absorbing anisotropic film having a non-planar portion. Examples of methods for producing an optically absorbing anisotropic film by molding a planar optically absorbing anisotropic film to produce an optically absorbing anisotropic film having a non-planar portion include a method using a mold having a convex molding surface and a mold having a concave molding surface (Method 1), and a method for molding the planar optically absorbing anisotropic film by heating the film with a heating temperature distribution in the in-plane direction (Method 2). Below, we will first describe Production Methods A and B for producing a planar optically absorbing anisotropic film, and then we will describe Methods 1 and 2 in detail. In the following explanation of Methods 1 and 2, we will describe in detail the procedure for obtaining the optically absorbing anisotropic film 10 shown in Figures 1 and 2 as an example.

[0048] <Method A for manufacturing a planar optically absorptive anisotropic film> Method A for manufacturing a planar optically absorptive anisotropic film comprises, in this order: a coating film formation step of forming a coating film by applying a composition for forming an optically absorptive anisotropic film containing a liquid crystal compound and a dichroic substance; and an orientation step of subjecting the formed coating film to a heat treatment in which the coating film is heated to a temperature above 70°C but not lower than the melting point of the liquid crystal compound, and a cooling treatment in which the coating film is cooled to less than 40°C after the heat treatment, wherein the time required for cooling from 70°C to 40°C in the cooling treatment is 2 seconds or less. Note that the orientation step is a step in which the liquid crystalline component contained in the coating film is oriented, and the liquid crystalline component is a component that includes not only the liquid crystal compound but also the dichroic substance having liquid crystallinity when the dichroic substance has liquid crystallinity.

[0049] -Coating film forming process- The coating film forming process is a process of forming a coating film by applying a composition for forming an optically absorptive anisotropic film onto a planar substrate. Here, the composition for forming an optically absorptive anisotropic film contains the dichroic substance and liquid crystal compound described above, but may also contain the solvent, polymerization initiator, surfactant, and other components described above. The substrate used in this process is not particularly limited, and any known planar substrate can be used. An alignment film may also be provided on the substrate, if necessary. By providing an alignment film, the liquid crystalline component can be aligned. Examples of the alignment film include a photo-alignment film.

[0050] Examples of methods for applying the composition for forming an optically absorptive anisotropic film 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.

[0051] - Orientation step - The orientation step is a step of subjecting the coating film to a heat treatment in which the coating film is heated to a temperature above 70°C and equal to or higher than the melting point of the liquid crystal compound, and a cooling treatment in which the coating film is cooled to less than 40°C after the heat treatment, wherein the time required for cooling from 70°C to 40°C in the cooling treatment is 2 seconds or less. This allows the liquid crystalline component contained in the coating film to be aligned, resulting in a planar optically absorptive anisotropic film, and makes it possible to suppress the occurrence of cracks when forming curved surfaces.

[0052] The heating temperature in the heat treatment is not particularly limited as long as it is above 70° C. and equal to or higher than the melting point of the liquid crystal compound, but from the viewpoint of manufacturability, it is preferably 100 to 200° C., more preferably 110 to 170° C. The heating time in the heat treatment is preferably 1 to 300 seconds, more preferably 1 to 60 seconds.

[0053] The cooling temperature in the cooling treatment is not particularly limited as long as it is less than 40° C., but it is preferable to cool the coating film after the heat treatment to about room temperature (20 to 25° C.). The cooling time in the cooling treatment is also not particularly limited as long as the time required to cool from 70° C. to 40° C. is 2 seconds or less, and is preferably 0.1 seconds or more and 1.5 seconds or less.

[0054] Other Steps The method for forming a planar optically absorptive anisotropic film may include a step of curing the optically absorptive anisotropic film (hereinafter also referred to as a "curing step") after the above-described alignment step. For example, when the compound contained in the optically absorptive anisotropic film has a 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 from the viewpoint of productivity. Various light sources, such as infrared, visible light, and 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. Furthermore, exposure may be performed under a nitrogen atmosphere. When the 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.

[0055] <Method B for producing a planar optically absorbing anisotropic film> Method B for producing a planar optically absorbing anisotropic film includes an underwater stretching step in which a polyvinyl alcohol-based resin layer is stretched in water, and the temperature during the underwater stretching step is 90°C or higher. The temperature during the underwater stretching step is preferably 90 to 120°C, more preferably 90 to 110°C. Here, in addition to the underwater stretching step described above, the method B for producing a planar optically absorbing anisotropic film described above may include, for example, steps such as an air-assisted stretching treatment, an insolubilization treatment, a dyeing treatment, a crosslinking treatment, a washing treatment, and a drying shrinkage treatment. For each of these steps, known methods such as the method described in Example 1 of the above-mentioned Patent Document 2 (JP 2022-75143 A) can be appropriately adopted, and the dyeing treatment and crosslinking treatment may be performed during the underwater stretching treatment step.

[0056] <Method 1> Method 1 uses a mold having a convex molding surface and a mold having a concave molding surface. First, the phenomenon that occurs when a film is molded using a mold having a concave molding surface will be described with reference to Figures 3 to 5. Figures 3 and 4 show the procedure for molding a film using a mold having a concave molding surface, and Figure 5 shows the film used for molding. As shown in Figure 3, a circular film 22 is placed on a mold 20 having a concave molding surface, and as shown in Figure 4, the film 22 is deformed so as to fit the molding surface of the mold 20, thereby obtaining a film 24 with the concave shape transferred thereto.

[0057] Next, the phenomenon that occurs when a film is molded using a mold having a convex molding surface will be explained using Figures 5 to 7. Figures 6 and 7 show the procedure for molding a film using a mold having a convex molding surface, and Figure 5 shows the film used for molding. As shown in Figure 6, a circular film 22 is placed on a mold 26 having a convex molding surface, and as shown in Figure 7, film 22 is deformed so as to fit the molding surface of mold 26, thereby obtaining a film 28 with the convex shape transferred thereto.

[0058] <Method 2> Method 2 is a method of molding a planar optically absorbing anisotropic film by heating it with a heating temperature distribution in the in-plane direction during molding. A first embodiment of Method 2 includes a manufacturing method comprising the steps of heating a planar optically absorbing anisotropic film so that the heating temperature of the peripheral portion surrounding the central portion of the planar optically absorbing anisotropic film is higher than the heating temperature of the central portion of the planar optically absorbing anisotropic film, and then deforming the heated planar optically absorbing anisotropic film along the molding surface using a mold having a concave molding surface. A second embodiment of Method 2 includes a manufacturing method comprising the steps of heating a planar optically absorbing anisotropic film so that the heating temperature of the peripheral portion surrounding the central portion is lower than the heating temperature of the central portion of the planar optically absorbing anisotropic film, and then deforming the heated planar optically absorbing anisotropic film along the molding surface using a mold having a convex molding surface.

[0059] The first embodiment of Method 2 will be representatively described below with reference to the drawings.

[0060] The heating conditions for the optically absorbing anisotropic film in Method 2 are appropriately selected optimally depending on the type of material of the optically absorbing anisotropic film used and the shape of the non-planar portion. In particular, the heating temperature is preferably equal to or higher than the glass transition temperature of the optically absorbing anisotropic film. There is no particular upper limit to the heating temperature, but it is preferably within (the glass transition temperature of the optically absorbing anisotropic film + 100°C). While the above description has been given of heating the optically absorbing anisotropic film itself, the laminate described below may also be applied to Method 2. In this case, if the laminate includes a support, it is preferable to heat the laminate to a temperature equal to or higher than the glass transition temperature of the support during the heat treatment.

[0061] The heating method in Method 2 is not particularly limited, and examples thereof include heating by contact with a heated solid, heating by contact with a heated liquid, heating by contact with a heated gas, heating by infrared radiation, heating by microwave radiation, etc. Among these, heating by infrared radiation, which allows heating remotely just before molding, is preferred.

[0062] The wavelength of the infrared radiation used for heating is preferably 1.0 to 30.0 μm, more preferably 1.5 to 5 μm. Examples of IR (infrared) light sources include near-infrared lamp heaters with a tungsten filament sealed in a quartz tube, and wavelength-controlled heaters with multiple quartz tubes and a mechanism for cooling a portion of the space between the quartz tubes with air. Methods for creating an intensity distribution of infrared radiation include varying the density of IR light sources and placing a filter with a patterned infrared transmittance between the IR light source and the planar optically absorptive anisotropic film. Examples of filters with patterned transmittance include glass with metal vapor deposition, a cholesteric liquid crystal layer with an infrared reflection band, a dielectric multilayer film with an infrared reflection band, and infrared-absorbing ink. The temperature of the planar optically absorptive anisotropic film is controlled by the intensity of the infrared radiation, and by the infrared radiation duration and irradiance. The temperature of the planar optically absorptive anisotropic film can be monitored using a non-contact radiation thermometer and a thermocouple, and molding can be performed at a target temperature.

[0063] [Laminate] The laminate of the present invention includes the above-mentioned optically absorptive anisotropic film. The laminate of the present invention includes other components in addition to the above-mentioned optically absorptive anisotropic film. The other components are not particularly limited, but include, for example, a retardation layer, a reflective polarizer layer (e.g., a cholesteric liquid crystal layer, a linear polarization type reflective polarizer, etc.), a surface antireflection layer, a pressure-sensitive adhesive layer, a support, and an alignment film. Among these, the other components preferably include a retardation layer and a reflective polarizer layer. That is, the laminate of the present invention is preferably a laminate having a optically absorptive anisotropic film, a retardation layer, and a reflective polarizer layer.

[0064] FIG. 8 shows an example of a laminate of the present invention. The laminate 50A shown in FIG. 8 includes, in this order, an optically absorptive anisotropic film 52, a retardation layer 54 having the function of converting linearly polarized light into circularly polarized light, a positive C plate 56, and a cholesteric liquid crystal layer 58. FIG. 9 shows another example of a laminate of the present invention. The laminate 50B shown in FIG. 9 includes, in this order, an optically absorptive anisotropic film 52, a linear polarization type reflective polarizer 60, a retardation layer 54 having the function of converting linearly polarized light into circularly polarized light, and a positive C plate 56. As shown in FIGS. 8 and 9, all components included in the laminates 50A and 50B have the same curved surface shape as the optically absorptive anisotropic film 52. When the retardation layer 54 in the laminates 50A and 50B is a λ / 4 plate, the angle between the slow axis of the retardation layer 54 and the transmission axis of the optically absorptive anisotropic film 52 is preferably within the range of 45°±10°. The laminates 50A and 50B each include two retardation layers: a retardation layer 54 and a positive C plate 56. A retardation layer having the function of converting linearly polarized light into circularly polarized light may be disposed on the side of the optically absorptive anisotropic film 52 of the laminate 50A opposite the retardation layer 54. A retardation layer having the function of converting linearly polarized light into circularly polarized light may be disposed on the side of the optically absorptive anisotropic film 52 of the laminate 50B opposite the linear polarization type reflective polarizer 60. The laminates 50A and 50B are suitable for use in the goggle-type display device described below. The optically absorptive anisotropic film 52 is the optically absorptive anisotropic film described above. The optically absorptive anisotropic film 52 corresponds to the optically absorptive anisotropic film 10 shown in FIGS. 1 and 2. Components other than the optically absorptive anisotropic film included in the laminate will be described in detail below.

[0065] [Retardation Layer Having the Function of Converting Linearly Polarized Light into Circularly Polarized Light] A retardation layer having the function of converting linearly polarized light into circularly polarized light (hereinafter also simply referred to as a "specific retardation layer") is a type of retardation layer. The specific retardation layer is not particularly limited as long as it has the function of converting linearly polarized light into circularly polarized light, and examples thereof include a λ / 4 plate. A λ / 4 plate is a plate having a λ / 4 function, specifically, a plate having the function of converting linearly polarized light of a certain wavelength (preferably visible light) into circularly polarized light (or circularly polarized light into linearly polarized light). The in-plane retardation of the λ / 4 plate at a wavelength of 550 nm is not particularly limited, but is preferably 120 to 150 nm, more preferably 125 to 145 nm, and even more preferably 135 to 140 nm. In addition to the λ / 4 plate, a retardation layer whose in-plane retardation at a wavelength of 550 nm is 3 / 4 or 5 / 4 of the wavelength of any light in visible light is also preferred.

[0066] The specific retardation layer may have reverse wavelength dispersion.The term "reverse wavelength dispersion" means that the retardation value at the wavelength increases as the wavelength increases.The specific retardation layer may also have a multi-layer structure, and a specific embodiment of this case may be a broadband λ / 4 plate formed by laminating a λ / 4 plate and a λ / 2 plate.The angle between the slow axis of the specific retardation layer and the absorption axis of the light absorption anisotropic film is not particularly limited, but is preferably within 45°±10°.

[0067] The specific retardation layer may be the layer that is made by fixing the liquid crystal compound that is twisted and aligned with the thickness direction as the helical axis.For example, as disclosed in Japanese Patent No. 05753922 and Japanese Patent No. 05960743, the retardation layer that has the layer that is made by fixing the rod-shaped liquid crystal compound or discotic liquid crystal compound that is twisted and aligned with the thickness direction as the helical axis can be enumerated.

[0068] The thickness of the specific retardation layer is not particularly limited, but is preferably 0.1 to 8 μm, more preferably 0.3 to 5 μm.

[0069] [Positive C Plate] A positive C plate is a type of retardation layer. A positive C plate is a retardation layer having an in-plane retardation of substantially zero and a negative retardation in the thickness direction. The positive C plate functions as an optical compensation layer for increasing the degree of polarization of transmitted light with respect to obliquely incident light. The in-plane retardation of the positive C plate at a wavelength of 550 nm is preferably 10 nm or less. The retardation of the positive C plate in the thickness direction at a wavelength of 550 nm is preferably −600 to −40 nm.

[0070] The material for forming the positive C plate is not particularly limited, but it is preferably formed from a composition containing a liquid crystal compound. Such a positive C plate can typically be obtained by vertically aligning a rod-shaped polymerizable liquid crystal compound contained in a polymerizable liquid crystal composition and fixing the alignment state by polymerization. Alternatively, the positive C plate can be formed from a composition containing a side-chain polymer liquid crystal compound as the liquid crystal compound.

[0071] The thickness of the positive C plate is not particularly limited, but from the viewpoint of thinning, it is preferably 0.5 to 10 μm, and more preferably 0.5 to 5 μm.

[0072] [Cholesteric Liquid Crystal Layer] A cholesteric liquid crystal layer is an optical component that separates incident light into right-handed circularly polarized light and left-handed circularly polarized light, specularly reflecting one circularly polarized light and transmitting the other circularly polarized light. Examples of cholesteric liquid crystal layers include cholesteric liquid crystal layers formed by fixing a cholesteric liquid crystal phase. Cholesteric liquid crystal layers are preferred as optical films used for curved surface molding because they suppress a decrease in the degree of polarization and distortion of the polarization axis when stretched or molded into a three-dimensional shape. Furthermore, they are less likely to experience a decrease in the degree of polarization due to distortion of the polarization axis.

[0073] The cholesteric liquid crystal layer preferably includes a blue light-reflecting layer having a reflectance of 40% or more at a wavelength of 460 nm, a green light-reflecting layer having a reflectance of 40% or more at a wavelength of 550 nm, a yellow light-reflecting layer having a reflectance of 40% or more at a wavelength of 600 nm, and a red light-reflecting layer having a reflectance of 40% or more at a wavelength of 650 nm. This configuration is preferable because it can exhibit high reflection characteristics over a wide wavelength range in the visible range. The reflectances mentioned above are those when unpolarized light is incident on the cholesteric liquid crystal layer at each wavelength. The cholesteric liquid crystal layer may also have a pitch gradient structure in which the helical pitch of the cholesteric liquid crystal phase is continuously varied in the thickness direction.

[0074] It is also preferable to use, as the cholesteric liquid crystal layer, a cholesteric liquid crystal layer formed by fixing a cholesteric liquid crystal phase containing a rod-shaped liquid crystal compound and a cholesteric liquid crystal layer formed by fixing a cholesteric liquid crystal phase containing a discotic liquid crystal compound in combination. In such a configuration, the cholesteric liquid crystal phase containing the rod-shaped liquid crystal compound has a positive Rth, while the cholesteric liquid crystal phase containing the discotic liquid crystal compound has a negative Rth, so that the Rths of the two phases are offset, thereby suppressing the occurrence of ghosts even when light is incident from an oblique direction, which is preferable.

[0075] The thickness of the cholesteric liquid crystal layer is not particularly limited, but is preferably 30 μm or less, more preferably 15 μm or less, from the viewpoint of thinning. There is no particular lower limit, and it is often 1 μm or more.

[0076] [Linearly Polarized Reflective Polarizer] A linearly polarized reflective polarizer is a polarizer that reflects one of mutually orthogonal linearly polarized light beams and transmits the other linearly polarized light beam. Examples of linearly polarized reflective polarizers include a film obtained by stretching a dielectric multilayer film and a wire grid polarizer. Commercially available products include a reflective polarizer (product name APF) manufactured by 3M and a wire grid polarizer (product name WGF) manufactured by Asahi Kasei Corporation.

[0077] [Surface Antireflection Layer] The laminate of the present invention may have a surface antireflection layer. In the laminate of the present invention, the surface antireflection layer is preferably disposed on the surface-most side. The surface antireflection layer may be disposed on only one surface side of the laminate, or on both surfaces. The type of surface antireflection layer is not particularly limited, but from the viewpoint of further reducing the reflectance, moth-eye films and AR (Anti-Reflection) films are preferred. Furthermore, moth-eye films are preferred because they can maintain high antireflection performance even when the film thickness varies due to stretching and molding. The angle between the transmission axis of the linear polarization type reflective polarizer and the transmission axis of the light absorption anisotropic film is preferably within the range of 0 to 10°.

[0078] [Adhesive Layer] The laminate of the present invention may or may not have an adhesive layer. When the laminate has an adhesive layer, the number of adhesive layers is preferably one or two. Examples of adhesives constituting the adhesive layer include pressure-sensitive adhesives and adhesives. Examples of adhesives include rubber-based adhesives, acrylic-based adhesives, silicone-based adhesives, urethane-based adhesives, vinyl alkyl ether-based adhesives, polyvinyl alcohol-based adhesives, polyvinylpyrrolidone-based adhesives, polyacrylamide-based adhesives, and cellulose-based adhesives, with acrylic-based adhesives (pressure-sensitive adhesives) being preferred. Examples of adhesives include aqueous adhesives, solvent-based adhesives, emulsion-based adhesives, solventless adhesives, active energy ray-curable adhesives, and heat-curable adhesives. Examples of active energy ray-curable adhesives include electron beam-curable adhesives, ultraviolet-curable adhesives, and visible light-curable adhesives, with ultraviolet-curable adhesives being preferred.

[0079] The thickness of the pressure-sensitive adhesive layer is not particularly limited, but from the viewpoint of thinning, it is preferably 25 μm or less, more preferably 15 μm or less, and even more preferably 5 μm or less. The lower limit is not particularly limited, and it is often 0.1 μm or more.

[0080] [Support] The laminate of the present invention may have a support. The support can be placed in any location. For example, when the cholesteric liquid crystal layer and the retardation layer are films to be transferred from a temporary support, the support can be used as the transfer destination. The type of support is not particularly limited, but a transparent support is preferred. Examples include films such as cellulose acylate, polycarbonate, polysulfone, polyethersulfone, polyacrylate, polymethacrylate, cyclic polyolefin, polyolefin, polyamide, polystyrene, and polyester. Among these, cellulose acylate film, cyclic polyolefin film, polyacrylate film, or polymethacrylate film is preferred as the support. Commercially available cellulose acetate films (e.g., "TD80U" and "Z-TAC" manufactured by Fujifilm Corporation) can also be used. Furthermore, it is preferable that the support have a small retardation. Specifically, the in-plane retardation at a wavelength of 550 nm is preferably 10 nm or less, and the absolute value of the retardation in the thickness direction at a wavelength of 550 nm is preferably 50 nm or less.

[0081] From the viewpoint of stretching and forming treatments, the support preferably has a tan δ peak temperature of 170° C. or less. From the viewpoint of enabling forming at low temperatures, the tan δ peak temperature is preferably 150° C. or less, more preferably 130° C. or less.

[0082] Here, the method for measuring tan δ will be described. Using a dynamic viscoelasticity measuring device (DVA-200 manufactured by IT Measurement Control Co., Ltd.), E" (loss modulus) and E' (storage modulus) are measured under the following conditions for a film sample that has been conditioned in advance in an atmosphere at a temperature of 25°C and a humidity of 60% Rh for at least 2 hours, and the value obtained from this is tan δ (= E" / E'). Device: DVA-200 manufactured by IT Measurement Control Co., Ltd. Sample: 5 mm, length 50 mm (gap 20 mm) Measurement conditions: tension mode Measurement temperature: -150 to 220°C Heating condition: 5°C / min Frequency: 1 Hz

[0083] The thickness of the support is not particularly limited, but is preferably from 5 to 300 μm, more preferably from 5 to 100 μm, and even more preferably from 5 to 30 μm.

[0084] The thickness of the laminate is not particularly limited, but when the laminate does not include a pressure-sensitive adhesive layer or a support, the thickness of the laminate is preferably 30 μm or less, more preferably 25 μm or less. The lower limit is not particularly limited, but is often 10 μm or more. When the laminate includes one of a pressure-sensitive adhesive layer and a support, but does not include the other, the value obtained by subtracting the thickness of one of the layers from the thickness of the laminate is preferably 30 μm or less, more preferably 25 μm or less. The lower limit is not particularly limited, but is often 10 μm or more. When the laminate includes both a pressure-sensitive adhesive layer and a support, the value obtained by subtracting the thickness of the pressure-sensitive adhesive layer and the thickness of the support from the thickness of the laminate is preferably 30 μm or less, more preferably 25 μm or less. The lower limit is not particularly limited, but is often 10 μm or more.

[0085] [Method for producing laminate] The method for producing the laminate of the present invention is not particularly limited, and known methods can be used. For example, a laminate may be produced by laminating another member onto the surface of an optically absorptive anisotropic film having a non-planar shaped portion via a pressure-sensitive adhesive layer, or a moldable laminate may be produced by laminating another member onto the surface of a planar optically absorptive anisotropic film via a pressure-sensitive adhesive layer, and then the moldable laminate may be used to carry out the optically absorptive anisotropic film molding method described in Methods 1 and 2 above, thereby molding the moldable laminate into a predetermined shape, thereby producing a laminate including an optically absorptive anisotropic film having a non-planar shaped portion.

[0086] [Composite Lens] The composite lens of the present invention comprises the above-described laminate of the present invention, a lens, and a half mirror, in this order. FIG. 10 shows an example of the composite lens of the present invention. A composite lens 70 comprises a laminate 72, a lens 74, and a half mirror 76, in this order. As shown in FIG. 10, all of the components included in the composite lens 70 have the same curved surface shape as the optically absorptive anisotropic film. The configuration of the laminate 72 is as described above. The components other than the laminate included in the composite lens will be described in detail below.

[0087] [Lens] A compound lens has a lens. Examples of lenses include convex lenses and concave lenses. Examples of convex lenses include biconvex lenses, plano-convex lenses, and convex meniscus lenses. Examples of concave lenses include biconcave lenses, plano-concave lenses, and concave meniscus lenses. As lenses used in virtual reality display devices, convex meniscus lenses or concave meniscus lenses are preferred in terms of expanding the viewing angle, and concave meniscus lenses are more preferred in terms of minimizing chromatic aberration. Lens materials that are transparent to visible light, such as glass, crystal, and plastic, can be used. Since birefringence in lenses can cause rainbow unevenness and light leakage, the smaller the birefringence, the more preferable, and materials with zero birefringence are more preferred.

[0088] [Half Mirror] The composite lens of the present invention has a half mirror. The half mirror is a conventionally known half mirror that transmits approximately half of incident light and reflects the remaining approximately half. The transmittance of the half mirror is preferably 50±30%, more preferably 50±10%. The type of half mirror is not particularly limited, but examples include a reflective layer made of a metal. Examples of metals include silver and aluminum. The thickness of the reflective layer is preferably 1 to 20 nm, more preferably 2 to 10 nm, and even more preferably 3 to 6 nm.

[0089] [Goggle-Type Display Device] The goggle-type display device of the present invention has the optically absorptive anisotropic film, laminate, or composite lens of the present invention described above. Examples of goggle-type display devices include head-mounted displays, and more specifically, virtual reality display devices. FIG. 11 is a schematic diagram showing an example of the configuration of a goggle-type display device. The goggle-type display device 80 shown in FIG. 11 has, from the right side of the figure, an image display panel 82, a circular polarizer 84, a half mirror 86, a lens 88, and a laminate 90 of the present invention. Note that the laminate 90 used in FIG. 11 has a configuration similar to the laminate 50A described above, with the optically absorptive anisotropic film 52 positioned on the eye side. The laminate 90, lens 88, and half mirror 86 shown in FIG. 11 constitute the composite lens described above. In the goggle-type display device 80 shown in FIG. 11, light ray 92 emitted from the image display panel 82 passes through the circular polarizer 84 to become circularly polarized light, and then passes through the half mirror 86. The light ray 92 then passes through the lens 88, enters the reflective polarizer layer (e.g., a cholesteric liquid crystal layer) included in the laminate 90 of the present invention, is reflected, passes through the lens 88 again, is reflected again by the half mirror 86, passes through the lens 88 again, and enters the laminate 90. At this time, the circular polarization state of the light ray 92 does not change when reflected by the laminate 90, but when reflected by the half mirror 86, it changes to circular polarization with a direction of rotation opposite to that of the circular polarization when it entered the laminate 90. Therefore, the light ray 92 passes through the laminate 90 and is visually recognized by the user. Furthermore, when the light ray 92 is reflected by the half mirror 86, the image is magnified because the half mirror is shaped like a concave mirror, allowing the user to view the magnified virtual image. The above-mentioned mechanism is called a round-trip optical system or a folded optical system.

[0090] The image display panel 82 is a known image display panel (display panel) such as an organic electroluminescence display panel. In the illustrated example, the image display panel 82 emits an unpolarized image (image light). The unpolarized image emitted by the image display panel 82 passes through the circular polarizer 84 and is converted into circularly polarized light.

[0091] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. 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.

[0092] [Example 1] [Preparation of Absorptive Anisotropic Film A1 Having an Optically Absorbent Anisotropic Layer] <Preparation of Support> The following composition was charged into a mixing tank, stirred, and further heated at 90°C for 10 minutes. The resulting composition was then filtered through filter paper with an average pore size of 34 μm and a sintered metal filter with an average pore size of 10 μm to prepare a dope. The solid content of the dope was 23.5% by mass, the amount of plasticizer added was the ratio relative to the cellulose acylate, and the solvent for the dope was methylene chloride / methanol / butanol = 81 / 18 / 1 (mass ratio).

[0093] ------------------------------------------------ Cellulose acylate dope ---------------------------------------------------------------- Cellulose acylate (acetyl substitution degree 2.86, viscosity average degree of polymerization 310) 100 parts by mass Sugar ester compound 1 (formula (S4) below) 6.0 parts by mass Sugar ester compound 2 (formula (S5) below) 2.0 parts by mass Silica particle dispersion (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.) 0.1 part by mass Solvent (methylene chloride / methanol / butanol) 351.9 parts by mass

[0094]

[0095]

[0096] The dope prepared above was cast using a drum film-forming machine. The dope was cast from a die onto a metal support cooled to 0°C, and the resulting web (film) was then peeled off from the drum. The drum was made of SUS (stainless steel).

[0097] The web (film) obtained by casting was peeled from the drum and then dried for 20 minutes in a tenter apparatus, in which both ends of the web were clipped with clips while the film was being transported at 30 to 40°C. Subsequently, the web was post-dried by zone heating while being transported with a roll. The obtained web was knurled and then wound up to give cellulose acylate film A1. The obtained cellulose acylate film A1 had a thickness of 60 μm, an in-plane retardation Re(550) of 1 nm at a wavelength of 550 nm, and a thickness direction retardation Rth(550) of 35 nm at a wavelength of 550 nm.

[0098] <Formation of Photo-Alignment Film B1> A composition B1 for forming a photo-alignment film, which will be described later, was continuously applied onto the cellulose acylate film A1 using a wire bar. The cellulose acylate film A1 on which the coating film was formed was dried with hot air at 140°C for 120 seconds, and then the coating film was irradiated with polarized ultraviolet light (10 mJ / cm ２ A photo-alignment film B1 was formed by irradiating the substrate with a TAC (triacetyl cellulose) film having a photo-alignment film B1. The photo-alignment film B1 had a thickness of 1.5 μm.

[0099] ------------------------------------------------ Composition of composition B1 for forming photo-alignment film------------------------------------------------ - 100.00 parts by mass of photo-alignment compound PA-1 below - 55.74 parts by mass of EPICLON N-695 (manufactured by DIC Corporation) - 18.75 parts by mass of jER YX7400 (manufactured by Mitsubishi Chemical Corporation) - 8.01 parts by mass of polymerizable polymer PA-2 below - 16.75 parts by mass of thermal cationic polymerization initiator PAG-1 below - 1.06 parts by mass of stabilizer DIPEA below - 1230.49 parts by mass of butyl acetate------------------------------------------------

[0100] Photoalignment compound PA-1 (in the formula below, the numerical value for each repeating unit represents the content (mass%) of each repeating unit relative to all repeating units; weight average molecular weight: 32,000)

[0101] Polymerizable polymer PA-2 (in the following formula, the values ​​a, b, and c represent the content (mass%) of each repeating unit relative to the total repeating units; weight average molecular weight: 40,500)

[0102] Thermal cationic polymerization initiator PAG-1

[0103] Stabilizer DIPEA

[0104] <Formation of Optically Absorbent Anisotropic Film C1> A composition for forming an optically absorbent anisotropic film C1 having the following composition was applied to the obtained photo-alignment film B1 using a wire bar to form a coating film. Next, the coating film was heated at 140°C for 15 seconds (first heating step), and then cooled to room temperature (25°C). At this time, the time required for cooling from 70°C to 40°C was 2.2 seconds. Next, the coating film was heated at 80°C for 15 seconds (second heating step), and then cooled to room temperature again. Thereafter, an LED (light emitting diode) lamp (center wavelength 365 nm) was used to illuminate the coating film at an illuminance of 200 mW / cm. ２ The optically absorptive anisotropic film C1 (polarizer) having a thickness of 1.0 μm was prepared on the photo-alignment film B1 by irradiating the film with light for 2 seconds under the irradiation conditions of (1) to (7). The transmittance of the optically absorptive anisotropic film C1 in the wavelength range of 380 to 780 nm was measured using a spectrophotometer, and the average visible light transmittance was 43%. The absorption axis of the optically absorptive anisotropic film C1 was in the plane of the optically absorptive anisotropic film C1 and perpendicular to the width direction of the cellulose acylate film A1.

[0105] 0.04 parts by mass of the following adhesion improver A-1; 0.07 parts by mass of polymerization initiator IRGACUREOXE-02 (manufactured by BASF); 0.007 parts by mass of the following surfactant F-1; 94.97 parts by mass of cyclopentanone; benzyl alcohol 2.44 parts by mass ――――――――――――――――――――――――――――――

[0106] Dichroic substance Dye-Y1

[0107] Dichroic substance Dye-M1

[0108] Dichroic substance Dye-C1

[0109] Dichroic substance Dye-C2

[0110] Liquid crystal compound L-1 (in the formula below, the numerical values ​​("59", "15", "26") shown for each repeating unit represent the content (% by mass) of each repeating unit relative to all repeating units; weight average molecular weight: 18,000)

[0111] Liquid crystal compound L-2

[0112] Liquid crystal compound L-3

[0113] Adhesion improver A-1

[0114] Surfactant F-1 (wherein the numerical value for each repeating unit represents the content (% by mass) of each repeating unit relative to all repeating units; weight average molecular weight: 16,000)

[0115] <Formation of Protective Layer D1> A protective layer-forming coating solution D1 having the following composition was continuously applied onto the optically absorptive anisotropic film C1 using a wire bar. Thereafter, the coating was dried with hot air at 80°C for 5 minutes, and then irradiated with an LED lamp (center wavelength 365 nm) at an irradiation condition of 300 mJ to obtain a laminate having a 0.5 μm-thick protective layer D1 made of polyvinyl alcohol (PVA), i.e., an absorptive anisotropic film A1 having a cellulose acylate film A1 (support), a photo-alignment film B1, an optically absorptive anisotropic film C1, and a protective layer D1 adjacent to each other in this order.

[0116] -------------------------------------------------- Composition of coating liquid D1 for forming protective layer -------------------------------------------------- 3.31 parts by mass of modified polyvinyl alcohol shown below; 0.17 parts by mass of initiator IRGACURE 2959 (manufactured by BASF); 0.07 parts by mass of glutaraldehyde; 0.05 parts by mass of pyridinium paratoluenesulfonate; 0.0018 parts by mass of surfactant F-9 shown below; 74.0 parts by mass of water; 22.4 parts by mass of ethanol.

[0117] Modified polyvinyl alcohol (in the formula below, the numerical value for each repeating unit represents the content (% by mass) of each repeating unit relative to all repeating units; weight average molecular weight: 14,000)

[0118] Surfactant F-9

[0119] [Example 2] An absorptive polarizing film A2 was produced in the same manner as in Example 1, except that the following composition C2 for forming an optically absorptive anisotropic film was used instead of composition C1 for forming an optically absorptive anisotropic film, and the time required for cooling from 70°C to 40°C in the cooling treatment after the first heating step was changed to 1.3 seconds. 0.04 parts by mass of the adhesion improver A-1; 0.07 parts by mass of polymerization initiator IRGACUREOXE-02 (manufactured by BASF); 0.007 parts by mass of the surfactant F-1; 94.97 parts by mass of cyclopentanone; 2.44 parts by mass of benzyl alcohol. ----------------------------------------------------------------------------------

[0120] Example 3 An absorptive polarizing film A3 was produced in the same manner as in Example 1, except that the time required for cooling from 70° C. to 40° C. in the cooling treatment after the first heating step was changed to 1.1 seconds.

[0121] [Example 4] An absorptive polarizing film A4 was produced in the same manner as in Example 1, except that the following composition C4 for forming an optically absorptive anisotropic film was used instead of composition C1 for forming an optically absorptive anisotropic film, and the time required for cooling from 70°C to 40°C in the cooling treatment after the first heating step was changed to 2.3 seconds. 0.04 parts by mass of the adhesion improver A-1; 0.07 parts by mass of polymerization initiator IRGACUREOXE-02 (manufactured by BASF); 0.007 parts by mass of the surfactant F-1; 94.97 parts by mass of cyclopentanone; and 0.22 parts by mass of the liquid crystal compound L-4. 2.44 parts by mass ――――――――――――――――――――――――――――――

[0122] Liquid crystal compound L-4

[0123] Example 5 An absorptive polarizing film A5 was produced in the same manner as in Example 1, except that the following composition C5 for forming an optically absorptive anisotropic film was used instead of composition C1 for forming an optically absorptive anisotropic film. 0.04 parts by mass of the adhesion improver A-1; 0.07 parts by mass of polymerization initiator IRGACUREOXE-02 (manufactured by BASF); 0.007 parts by mass of the surfactant F-1; 94.97 parts by mass of cyclopentanone; and 0.22 parts by mass of the liquid crystal compound L-5. 2.44 parts by mass ――――――――――――――――――――――――――――――

[0124] Liquid crystal compound L-5

[0125] [Example 6] An absorptive polarizing film A6 was produced in the same manner as in Example 1, except that the following composition C6 for forming an optically absorptive anisotropic film was used instead of composition C1 for forming an optically absorptive anisotropic film, and the time required for cooling from 70°C to 40°C in the cooling treatment after the first heating step was changed to 2.4 seconds. ------------------------------------------------ Optically absorptive anisotropic film-forming composition C6 ------------------------------------------------ 0.77 parts by mass of dichroic substance Dye-Y2 below; 0.77 parts by mass of dichroic substance Dye-M2 below; 0.77 parts by mass of dichroic substance Dye-C2 below; 13.68 parts by mass of liquid crystal compound L-6 below; 6.84 parts by mass of liquid crystal compound L-7 below; 6.84 parts by mass of liquid crystal compound L-8 below; 1.64 parts by mass of polymerization initiator Omnirad 369 (manufactured by IGM Resins BV); 0.33 parts by mass of polyacrylate compound (BYK-361N, manufactured by BYK-Chemie); 68.38 parts by mass of cyclopentanone ------------------------------------------------

[0126] Dichroic substance Dye-Y2

[0127] Dichroic substance Dye-M2

[0128] Dichroic substance Dye-C2

[0129] Liquid crystal compound L-6

[0130] Liquid crystal compound L-7

[0131] Liquid crystal compound L-8

[0132] [Comparative Example 1] An absorptive polarizing film H1 was produced in the same manner as in Example 1, except that the optically absorptive anisotropic film-forming composition H1 described below was used instead of the optically absorptive anisotropic film-forming composition C1, and the time required for cooling from 70°C to 40°C in the cooling treatment after the first heating step was changed to 2.3 seconds. 0.04 parts by mass of the adhesion improver A-1; 0.07 parts by mass of polymerization initiator IRGACUREOXE-02 (manufactured by BASF); 0.007 parts by mass of the surfactant F-1; 94.97 parts by mass of cyclopentanone; 2.44 parts by mass of benzyl alcohol. ----------------------------------------------------------------------------------

[0133] Liquid crystal compound L-9 (a mixture of the following liquid crystal compounds (RA), (RB), and (RC) in a mass ratio of 84:14:2)

[0134] Comparative Example 2 Absorptive polarizing film H2 was produced in the same manner as in Example 2, except that the time required for cooling from 70° C. to 40° C. in the cooling treatment after the first heating step was changed to 2.2 seconds.

[0135] [Comparative Example 3] An absorptive polarizing film H3 was produced in the same manner as in Example 1, except that the optically absorptive anisotropic film-forming composition H3 described below was used instead of the optically absorptive anisotropic film-forming composition C1, and the time required for cooling from 70°C to 40°C in the cooling treatment after the first heating step was changed to 2.3 seconds. ―――――――――――――――――――――――――――――― Composition H3 for forming a light-absorbing anisotropic film ―――――――――――――――――――――――――――――― ・The above dichroic substance Dye-Y2 0.77 parts by mass ・The above dichroic substance Dye-M2 0.77 parts by mass ・The above dichroic substance Dye-C2 0.77 parts by mass ・The above liquid crystal compound L-6 20.51 parts by mass・Liquid crystal compound L-7 6.84 parts by mass・Polymerization initiator Omnirad369 (manufactured by IGM Resins BV) 1.64 parts by mass・Surfactant F-2 0.33 parts by mass・Cyclopentanone 68.38 parts by mass ――――――――――――――――――――――――――――――

[0136] [Example 7] [Preparation of Absorption-Type Anisotropic Film B1 Having an Optically Absorbent Anisotropic Film] One side of a polyethylene terephthalate (100 μm) resin substrate was subjected to corona treatment. Next, 100 parts by mass of a PVA-based resin prepared by mixing polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOSEFIMER") in a 9:1 ratio was mixed with 13 parts by mass of potassium iodide, and the mixture was dissolved in water to prepare an aqueous PVA solution (coating solution). The PVA aqueous solution was applied to the corona-treated surface of the resin substrate and dried to obtain a laminate, which was then uniaxially stretched 2.4 times in the longitudinal direction of the resin substrate at 130 ° C (in-air auxiliary stretching process). After stretching the laminate, the laminate was immersed in an insolubilizing bath (a boric acid aqueous solution obtained by blending 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40°C for 30 seconds (insolubilization treatment step). Thereafter, the laminate was immersed in a boric acid aqueous solution (boric acid concentration 4% by mass, potassium iodide concentration 5% by mass) at a liquid temperature of 70°C for 2 hours, and then uniaxially stretched in the longitudinal direction (longitudinal direction) to a total stretch ratio of 5.5 times while immersed in a boric acid aqueous solution (boric acid concentration 4% by mass, potassium iodide concentration 5% by mass) at a liquid temperature of 90°C (underwater stretching step). The laminate was then immersed in a washing bath (aqueous solution obtained by blending 3 parts by weight of potassium iodide with 100 parts by weight of water) at a liquid temperature of 20°C (washing treatment step). Furthermore, the laminate was brought into contact with a stainless steel heated roll whose surface temperature was maintained at approximately 75°C while being dried in an oven maintained at approximately 90°C (drying shrinkage treatment step). In this way, an optically absorptive anisotropic film P1 (polarizer P1) was formed on the resin substrate, and an absorptive anisotropic film B1 having a resin substrate / polarizer P1 structure was obtained. The thickness of the polarizer P1 in the absorptive anisotropic film B1 was 5 μm.

[0137] [Comparative Example 4] [Preparation of Absorptive Anisotropic Film H4 Having Optically Absorptive Anisotropic Film] An optically absorptive anisotropic film H4 (polarizer H4) was formed on a resin substrate in the same manner as in Example 7, except that the stretching temperature in the underwater stretching treatment step was 70° C. Absorptive anisotropic film H4 having a resin substrate / polarizer H4 configuration was obtained. The thickness of polarizer H4 in absorptive anisotropic film H4 was 5 μm.

[0138] Example 8 An absorptive polarizing film A8 was produced in the same manner as in Example 1, except that the following protective layer forming coating liquid D2 was used instead of the protective layer forming coating liquid D1.

[0139] -------------------------------- Composition of coating liquid D2 for forming protective layer-------------------------------- 3.19 parts by mass of the above-mentioned modified polyvinyl alcohol; 0.17 part by mass of initiator IRGACURE 2959 (manufactured by BASF); 0.05 part by mass of compound A1 below; 0.18 part by mass of pyridinium paratoluenesulfonate; 0.0054 part by mass of BYK-348 (manufactured by BYK-Chemie); 74.0 parts by mass of water; 22.4 parts by mass of ethanol.

[0140] Compound A1

[0141] [Evaluation] [Preparation of Retardation Layer Film 1 Having Positive A Plate] A coating solution E1 for forming a photo-alignment layer having the following composition was continuously coated on the above-mentioned cellulose acylate film A1 using a wire bar. The cellulose acylate film A1 on which the coating film was formed was dried with hot air at 140°C for 120 seconds, and then the coating film was irradiated with polarized ultraviolet light (10 mJ / cm ２ , using an ultra-high pressure mercury lamp) to form a photo-alignment film E1 with a thickness of 0.2 μm, thereby obtaining a TAC film with a photo-alignment film.

[0142] -------------------------------------------------- Coating liquid E1 for forming photoalignment film -------------------------------------------------- - 100.00 parts by mass of the polymer PA-2 shown below - 5.00 parts by mass of the thermal cationic polymerization initiator PAG-1 shown above - 0.005 parts by mass of the acid generator CPI-110TF shown below - 16.50 parts by mass of isopropyl alcohol - 1072.00 parts by mass of butyl acetate - 268.00 parts by mass of methyl ethyl ketone --------------------------------------------------

[0143] Polymer PA-2 (In the formula below, the numerical value for each repeating unit represents the content (% by mass) of each repeating unit relative to all repeating units; weight average molecular weight: 45,000)

[0144] Acid generator CPI-110TF

[0145] Composition F1 having the following composition was applied onto the photo-alignment film E1 using a bar coater. The coating film formed on the photo-alignment film E1 was heated to 120°C with hot air, then cooled to 60°C, and then irradiated with 100 mJ / cm2 at a wavelength of 365 nm using a high-pressure mercury lamp under a nitrogen atmosphere. ２ The coating film was irradiated with ultraviolet light of 500 mJ / cm 2 while being heated to 120°C. ２ The coating film was irradiated with ultraviolet light of 1000 nm, thereby fixing the alignment of the liquid crystal compound, and a retardation layer film 1 having a positive A plate F1 was produced. The thickness of the positive A plate F1 was 2.5 μm, and Re(550) was 144 nm. The positive A plate also satisfied the relationship Re(450)≦Re(550)≦Re(650). Re(450) / Re(550) was 0.82. The positive A plate corresponds to a so-called λ / 4 plate.

[0146] - 43.50 parts by mass of polymerizable liquid crystal compound LA-1 described below - 43.50 parts by mass of polymerizable liquid crystal compound LA-2 described below - 8.00 parts by mass of polymerizable liquid crystal compound LA-3 described below - 5.00 parts by mass of polymerizable liquid crystal compound LA-4 described below - 0.55 parts by mass of polymerization initiator PI-1 described below - 0.20 parts by mass of leveling agent T-1 described below - 235.00 parts by mass of cyclopentanone

[0147] Polymerizable liquid crystal compound LA-1 (tBu represents a tertiary butyl group)

[0148] Polymerizable liquid crystal compound LA-2

[0149] Polymerizable liquid crystal compound LA-3

[0150] Polymerizable liquid crystal compound LA-4 (Me represents a methyl group)

[0151] Polymerization initiator PI-1

[0152] Leveling agent T-1 (in the formula below, the numerical value for each repeating unit represents the content (mass %) of each repeating unit relative to all repeating units; weight average molecular weight: 25,000)

[0153] [Preparation of Retardation Layer Film 2 Having Positive C Plate] The above-described cellulose acylate film A1 was used as a temporary support. The cellulose acylate film A1 was passed through a dielectric heating roll at a temperature of 60°C to raise the surface temperature of the film to 40°C, and then an alkaline solution having the composition shown below was applied to one side of the film using a bar coater in an amount of 14 ml / m. ２The film was heated to 110°C and transported for 10 seconds under a steam-type far-infrared heater manufactured by Noritake Co., Ltd. Next, pure water was applied to the film at a rate of 3 ml / m using the same bar coater. ２ Next, after repeating washing with water using a fountain coater and draining with an air knife three times, the film was transported to a drying zone at 70° C. for 10 seconds and dried to prepare an alkali-saponified cellulose acylate film A1.

[0154] ---------------------------------------------------------------- (Alkaline solution) ---------------------------------------------------------------- Potassium hydroxide 4.7 parts by mass, water 15.8 parts by mass, isopropanol 63.7 parts by mass, fluorine-containing surfactant SF-1 (C １４ H ２９ O (CH ２ CH ２ O) ２０ H) 1.0 part by mass; Propylene glycol 14.8 parts by mass

[0155] An alignment film-forming coating solution G1 having the following composition was continuously applied onto the above-mentioned alkali-saponified cellulose acylate film A1 using a #8 wire bar, and the resulting film was dried with hot air at 60°C for 60 seconds and then with hot air at 100°C for 120 seconds to form an alignment film G1.

[0156] ------------------------------------------------------------------ Coating liquid G1 for forming alignment film ------------------------------------------------------------------ Polyvinyl alcohol (PVA103, manufactured by Kuraray) 2.4 parts by mass Isopropyl alcohol 1.6 parts by mass Methanol 36 parts by mass Water 60 parts by mass ------------------------------------------------------------------

[0157] A coating solution H1 for forming a positive C plate having the following composition was applied onto the alignment film G1, and the resulting coating film was aged at 60° C. for 60 seconds, and then irradiated with 70 mW / cm 2 ２ An air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) was used, and the light output was 1000 mJ / cm ２ The liquid crystal compound was vertically aligned by irradiating the film with ultraviolet light of 1000 W at 1000 W to fix the alignment state, thereby producing a retardation layer film 2 having a positive C plate H1 with a thickness of 0.5 μm. The Rth(550) of the obtained positive C plate was −60 nm.

[0158] Coating liquid H1 for forming a positive C-plate -------------------------------- 80 parts by mass of the following liquid crystal compound LC-1 20 parts by mass of the following liquid crystal compound LC-2 1 part by mass of the following vertical alignment liquid crystal compound promoter S01 8 parts by mass of ethylene oxide-modified trimethylolpropane triacrylate (V#360, manufactured by Osaka Organic Chemical Industry Co., Ltd.) 3 parts by mass of Irgacure 907 (manufactured by BASF) 1 part by mass of Kayacure DETX (manufactured by Nippon Kayaku Co., Ltd.) 0.4 parts by mass of the following compound B03 170 parts by mass of methyl ethyl ketone 30 parts by mass of cyclohexanone --------------------------------

[0159] Liquid crystal compound LC-1

[0160] Liquid crystal compound LC-2

[0161] Vertical alignment liquid crystal compound promoter S01

[0162] Compound B03 (In the formula below, the numerical value for each repeating unit represents the content (% by mass) of each repeating unit relative to all repeating units; weight average molecular weight: 15,000)

[0163] [Preparation of Optical Laminate B0] The optical laminate B0 was prepared by the following procedure. A broadband dielectric multilayer film (trademark APF, 3M) was used as a linear polarization type reflective polarizer. The positive A plate side of the obtained retardation layer film 1 was attached to one surface of the APF, and the alignment layer and support were peeled off. Furthermore, the alignment film was peeled off, and the positive C plate side of the obtained retardation layer film 2 was attached to the exposed liquid crystal surface with an adhesive, and the support and alignment layer were peeled off. In this way, an optical laminate B0 consisting of a linear polarization type reflective polarizer / adhesive layer / positive A plate / positive C plate was prepared.

[0164] [Formation of Half Mirror Lens] Aluminum was deposited on the convex side of a lens (a convex meniscus lens LE1076-A (diameter 2 inches) manufactured by Thorlab) so that the reflectance was 40%, thereby forming a half mirror lens.

[0165] [Preparation of Absorptive Polarizer Film 1MK5] The protective layer side of the absorptive polarizer film A1 prepared in Example 1 was bonded to a PMMA film via an adhesive sheet, and only the support was peeled off to form absorptive polarizer film 1M, which was then set in a molding device. At this time, the PMMA film side was positioned downward. The molding space within the molding device consisted of box 1 and box 2, separated by absorptive polarizer film 2. Mold 1 (a convex lens with a diameter of 2 inches and a curvature radius of 84 mm) was placed in box 1 below the absorptive polarizer film 1M, with the convex surface (molding surface) facing up. Furthermore, a transparent window was installed on the top of box 2 above the absorptive polarizer film 1M, and an IR light source for heating the absorptive polarizer film 1M was installed outside this window. Next, a vacuum was drawn using a vacuum pump to evacuate box 1 and box 2 to a pressure of 0.1 atmospheres or less. Next, in the step of heating the absorptive polarizer film 1M, infrared rays were irradiated and the absorptive polarizer film 1M was heated until its temperature reached 108 ° C. The glass transition temperature Tg of the PMMA film used as the support was 105 ° C., so the film was made to be easily stretched during molding. Next, in the step of pressing the absorptive polarizer film 1M against the mold 1 and deforming it to conform to the shape of the mold 1, gas was flowed into the box 2 from a gas cylinder to pressurize it to 300 kPa, and the absorptive polarizer film 1M was pressure-bonded to the mold 1. Finally, the absorptive polarizer film 1M was removed from the lens, which was the mold 1. This resulted in an absorptive polarizer film 1M molded into a non-planar shape. Next, the absorptive polarizer film 1M molded into a non-planar shape was set in a molding device, upside down from the initial molding, with the PMMA film side facing up. At this time, the non-planar region of the absorptive polarizer film 1M formed by the initial molding protruded downward. A meniscus lens (diameter 2 inches, radius of curvature of the concave surface 70 mm) with aluminum vapor-deposited on the convex surface was placed with the concave surface facing up just below the region molded into a non-planar shape in the absorptive polarizer film 1M, as the mold 2. Next, the insides of boxes 1 and 2 were each evacuated to a vacuum of 0.1 atmospheres or less using a vacuum pump.Next, in a step of heating the absorptive polarizer film 1M, the absorptive polarizer film 1M was irradiated with infrared rays and heated until its temperature reached 108° C. Next, in a step of pressing the absorptive polarizer film 1M against the mold 2 and deforming it to conform to the shape of the mold 2, gas was flowed into the box 2 from a gas cylinder to pressurize it to 300 kPa, and the absorptive polarizer film 1M was pressure-bonded to the mold 2. Finally, the absorptive polarizer film 1M was removed from the lens, which was the mold 2. In this way, an absorptive polarizer film 1MK5 molded onto a curved surface by molding method 1 was obtained.

[0166] [Preparation of Optical Laminate B0K5] The optical laminate B0 was set in a molding device. At this time, it was arranged so that the positive C plate side was on the bottom. Thereafter, an optical laminate B0K5 molded into a non-planar shape was obtained in the same manner as in the preparation method of the absorptive polarizer film 1MK5.

[0167] [Preparation of Optical Laminate B1K5] The APF (linearly polarized reflective polarizer) side of the optical laminate B0K5 obtained above was bonded to the photo-alignment film side of the absorptive polarizer film 1MK5 with an adhesive. The lamination was performed so that the transmission axis of the APF and the transmission axis of the optically absorptive anisotropic film coincided. This produced an optical laminate B1K5 consisting of a positive C plate / positive A plate / adhesive layer / APF / adhesive layer / absorptive polarizer film.

[0168] [Preparation of a composite lens] The half-mirror lens prepared above was adjusted to the lens diameter and curvature radius of mold 2 and molded into a non-planar shape in the same manner as in the preparation of absorptive polarizer film 1MK5. Next, the prepared optical laminate B1K5 was attached to the concave side of the non-planar molded half-mirror lens with an adhesive to obtain a composite lens. A composite lens was obtained in the same manner as above, except that the absorptive polarizer films prepared in Examples 2 to 8 and Comparative Examples 1 to 4 were used instead of absorptive polarizer film A1.

[0169] [Measurement of haze on the transmission axis side] The protective layer side of the absorptive anisotropic film used in the examples and comparative examples was attached to a PMMA film by UV adhesion, and only the support of the absorptive polarizer film was peeled off to prepare a sample (a sample for measuring the haze on the transmission axis side). This sample was molded under the same conditions as those for molding a non-planar surface used in the production of a composite lens to obtain a curved measurement sample X, and the haze on the transmission axis side was measured using the obtained curved measurement sample X. Note that the obtained curved measurement sample X contained a photo-alignment film, a light-absorption anisotropic film, a protective layer, and a PMMA film, but it was confirmed that the photo-alignment film, the protective layer, and the PMMA film did not affect the haze on the transmission axis side. Furthermore, for the haze on the transmission axis side of the optically absorptive anisotropic film in the obtained curved surface-molded measurement sample X, a 2 cm square was cut out from the center of the measurement sample X and attached to a glass plate, and the haze on the transmission axis side was measured using an automatic polarizing film measuring device VAP-7070 manufactured by JASCO Corporation under the measurement conditions and calculation method described above. The results are shown in Tables 1 to 3 below.

[0170] [Crack Resistance] Forty composite lenses were produced in the examples and comparative examples, and cracks in the laminate on the concave surface of the composite lenses were visually inspected and evaluated according to the following criteria. The results are shown in Tables 1 to 3 below. <Evaluation Criteria> AA: Cracks occurred in 0 to 2 lenses A: Cracks occurred in 3 to 5 lenses B: Cracks occurred in 6 to 10 lenses C: Cracks occurred in 11 to 15 lenses D: Cracks occurred in 16 to 40 lenses

[0171]

[0172]

[0173]

[0174] As shown in Tables 1 to 3, it was found that when the haze on the transmission axis side of the optically absorptive anisotropic film exceeds 0.40%, the crack resistance is poor (Comparative Examples 1 to 4). In contrast, it was found that when the haze on the transmission axis side of the optically absorptive anisotropic film is 0.40% or less, the crack resistance is excellent (Examples 1 to 8). In particular, comparison of Examples 1 to 6 revealed that, in order to achieve better crack resistance, the haze on the transmission axis side of the optically absorptive anisotropic film is preferably 0.35% or less, more preferably 0.30% or less, and even more preferably 0.25% or less. Furthermore, comparison of Example 1 and Comparative Example 2 revealed that when the optically absorptive anisotropic film-forming composition contains three or more liquid crystal compounds that satisfy predetermined conditions, the haze on the transmission axis side of the optically absorptive anisotropic film can be adjusted to 0.40% or less. Furthermore, a comparison between Example 2 and Comparative Example 2 revealed that when the time required for cooling from 70°C to 40°C in the cooling treatment in the orientation step was 2 seconds or less, the haze on the transmission axis side of the optically absorbing anisotropic film could be adjusted to 0.40% or less. A comparison between Example 4 and Example 5 revealed that when the LogP values ​​of three or more liquid crystal compounds were all 5 or less, the haze on the transmittance side of the optically absorbing anisotropic film could be more easily adjusted to 0.40% or less, resulting in better crack resistance. A comparison between Example 7 and Comparative Example 4 revealed that when an optically absorbing anisotropic film was prepared by the above-mentioned method B for producing a planar optically absorbing anisotropic film (a method in which the temperature in the underwater stretching step was 90°C or higher), the haze on the transmission axis side of the optically absorbing anisotropic film could be adjusted to 0.40% or less.

[0175] REFERENCE SIGNS LIST 1 Maximum projected image 2 Circle X 3 Circle Y 4 Center of gravity 10 Light-absorbing anisotropic film Z Any four points on the circle Y 20 Mold having a concave molding surface 22 Film 24 Film to which a concave shape has been transferred 26 Mold having a convex molding surface 28 Film to which a convex shape has been transferred 50A, 50B Laminate 54 Retardation layer having the function of converting linearly polarized light into circularly polarized light 56 ​​Positive C plate 58 Cholesteric liquid crystal layer 60 Linearly polarized reflective polarizer 70 Compound lens 72, 90 Laminate 74, 88 Lens 76, 86 Half mirror 80 Goggle-type display device 82 Image display device 84 Circular polarizer 92 Light ray

Claims

1. An optically absorptive anisotropic film having a curved surface, wherein the haze on the transmission axis side calculated from the following formula (1) is 0.40% or less: (1-T2 / T1) x 100 (1) In formula (1), T1 refers to the transmittance on the transmission axis side of the optically absorptive anisotropic film measured using an integrating sphere, and T2 refers to the transmittance on the transmission axis side of the optically absorptive anisotropic film measured without using an integrating sphere.

2. The optically absorptive anisotropic film according to claim 1, wherein the curved surface portion has a curved surface that is not developable.

3. The optically absorptive anisotropic film according to claim 1, wherein the optically absorptive anisotropic film is a film obtained by fixing the alignment state of a composition for forming an optically absorptive anisotropic film, which contains a liquid crystal compound and a dichroic substance.

4. The optically absorptive anisotropic film according to claim 3, wherein the composition for forming an optically absorptive anisotropic film contains three or more liquid crystal compounds that satisfy the following condition: The mass X of the liquid crystal compound with the maximum content and the mass Y of the liquid crystal compound with the minimum content satisfy the following formula (2): X × 0.1 ≦ Y < X (2) 5. The optically absorptive anisotropic film according to claim 4, wherein the Log P values ​​of the three or more liquid crystal compounds are all 5 or less.

6. The optically absorptive anisotropic film according to claim 4, wherein the three or more liquid crystal compounds all have a biphenyl skeleton.

7. The optically absorptive anisotropic film according to claim 4, wherein at least one of the three or more liquid crystal compounds is a polymer liquid crystal compound.

8. The optically absorptive anisotropic film according to claim 1, wherein the thickness of said optically absorptive anisotropic film is 8 μm or less.

9. A laminate comprising the optically absorptive anisotropic film according to any one of claims 1 to 8.

10. The laminate according to claim 9, comprising the optically absorptive anisotropic film, a retardation layer, and a reflective polarizer layer.

11. A compound lens comprising, in this order, the laminate according to claim 9, a lens, and a half mirror.

12. A goggle-type display device comprising the laminate according to claim 9.

13. A method for producing an optically absorbing anisotropic film, which produces the optically absorbing anisotropic film described in claim 1, comprising: a coating film formation step of forming a coating film by applying a composition for forming an optically absorbing anisotropic film, which contains a liquid crystal compound and a dichroic substance; and an orientation step of subjecting the coating film to a heat treatment in which the coating film is heated to a temperature above 70°C but not lower than the melting point of the liquid crystal compound, and a cooling treatment in which the coating film is cooled to less than 40°C after the heat treatment, wherein the time required for cooling from 70°C to 40°C in the cooling treatment is 2 seconds or less.

14. A method for producing an optically absorbing anisotropic film, which produces the optically absorbing anisotropic film described in claim 1, comprising an underwater stretching step of stretching a polyvinyl alcohol-based resin layer in water, wherein the temperature during the underwater stretching step is 90°C or higher.

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