Optical anisotropic films, optical films, and display devices

Abstract

The present invention addresses the problem of providing: an optically anisotropic film which has a high contrast and excellent light resistance; an optical film; and a display device. An optically anisotropic film according to the present invention contains a liquid crystalline compound and a dichroic substance; the liquid crystalline compound is vertically aligned; the dichroic substance forms an array structure; and if a cross-section of this optically anisotropic film is observed with a scanning transmission electronic microscope, 16 or more array structures satisfying L ≥ 30 nm, wherein L represents the length of the major axis of an array structure and D represents the length of the minor axis of the array structure, are seen per an area of 40 μm2.

Description

[Technical Field]

[0001] This invention relates to optically anisotropic films, optical films, and display devices. [Background technology]

[0002] A technique is known that uses an optically anisotropic film with an absorption axis in the thickness direction to prevent people from looking into image display devices and to control the viewing angle. For example, Patent Document 1 discloses a viewing angle control system having a polarizer (optically anisotropic film) containing a dichroic substance in which the angle between the absorption axis and the normal to the film surface is 0° to 45°. [Prior art documents] [Patent Documents]

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

[0004] The present inventors investigated the viewing angle control system described in Patent Document 1 and found that there is room for improvement in the difference between the transmittance from the front direction and the transmittance from the oblique direction (hereinafter referred to as "contrast") of the film, and that it has poor light resistance, and in particular the transmittance from the oblique direction, which contributes to preventing peeping, changes significantly.

[0005] Therefore, the object of the present invention is to provide an optically anisotropic film, an optical film, and a display device that have high contrast and excellent light resistance. [Means for solving the problem]

[0006] As a result of intensive studies to achieve the above problems, the inventors have found that the liquid crystal compound is vertically aligned and the dichroic substance forms a specific number of array structures of a predetermined size, resulting in a high contrast and good light resistance of the optically anisotropic film, and completed the present invention. That is, it has been found that the above problems can be achieved by the following configuration.

[0007] [1] An optically anisotropic film containing a liquid crystal compound and a dichroic substance, where the liquid crystal compound is vertically aligned, the dichroic substance forms an array structure, and in a cross-section observed by a scanning transmission electron microscope, when the length of the long axis of the array structure is L and the length of the short axis is D, an array structure satisfying L≧30 nm is observed at 16 or more per 40 μm , , , , 2 , , ,

[0008] , , , , of the optically anisotropic film. [2] The optically anisotropic film according to [1], wherein the ratio of the number of array structures in which the angle formed by the long axis of the array structure and the normal direction of the optically anisotropic film is 20° or more is 28.0% or more. [3] The optically anisotropic film according to [1], wherein less than 3 array structures satisfying L≧240 nm are observed per 40 μm 2 . [4] An optical film having a transparent film substrate and an optically anisotropic film according to any one of [1] to [3] disposed on the transparent film substrate. [5] The optical film according to [4], further having an alignment film between the transparent film substrate and the optically anisotropic film. [6] Further having a polarizer having an absorption axis in the plane, and used for controlling the viewing angle, the optical film according to [4] or [5]. [7] A display device having the optical film according to [6] and a display element. [Advantages of the Invention]

[0008] According to the present invention, it is possible to provide an optically anisotropic film, an optical film, and a display device having high contrast and excellent light resistance. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a conceptual diagram showing an example of a state in which a first dichroic substance and a second dichroic substance form an arrangement structure. [Figure 2] Figure 2 is a conceptual diagram showing an example of the arrangement structure of the first dichroic substance and the second dichroic substance. [Figure 3] Figure 3 is a conceptual diagram showing a cross-section of an example of the optically anisotropic film of the present invention. [Figure 4] Figure 4 is a scanning transmission electron microscope image of a cross-section of the optically anisotropic film fabricated in Example 1. [Figure 5] Figure 5 is an image obtained by binarizing the brightness of the scanning transmission electron microscope image from Figure 4 using a predetermined threshold. [Modes for carrying out the invention]

[0010] The present invention will be described in detail below. The following description of the constituent elements may be based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In this specification, a numerical range represented by "~" means a range that includes the numbers written before and after "~" as the lower and upper limits, respectively. Furthermore, in this specification, parallel, orthogonal, horizontal, and vertical do not mean parallel, orthogonal, horizontal, and vertical in the strict sense, but rather mean a range of ±10° for parallel, ±10° for orthogonal, ±10° for horizontal, and ±10° for vertical, respectively. Furthermore, in this specification, each component may be represented by a single substance or by a combination of two or more substances. When two or more substances are used in combination for each component, the content of that component refers to the total content of the combined substances, unless otherwise specified. Furthermore, in this specification, "(meth)acrylate" refers to "acrylate" or "methacrylate," "(meth)acrylic" refers to "acrylic" or "methacrylic," and "(meth)acryloyl" refers to "acryloyl" or "methacryloyl."

[0011] [Optical anisotropy film] The optically anisotropic film of the present invention is an optically anisotropic film containing a liquid crystalline compound and a dichroic substance, wherein the liquid crystalline compound is vertically oriented and the dichroic substance forms an arranged structure. Furthermore, in the optically anisotropic film of the present invention, when observed in cross-section with a scanning transmission electron microscope, the arrangement structure satisfying L ≥ 30 nm is found to be 40 μm long, where L is the length of the long axis and D is the length of the short axis. 2 More than 16 are observed per unit.

[0012] In this invention, as described above, the liquid crystalline compound is vertically oriented, and the dichroic material has an arrangement structure satisfying L≧30nm, with a length of 40μm. 2 By forming 16 or more particles per unit area, the contrast of the optically anisotropic film is increased, resulting in good light resistance. Although this is not entirely clear, the inventors speculate the following: First, the contrast and lightfastness of optically anisotropic films are influenced by the presence of dichroic substances, and it is thought that lightfastness improves when dichroic substances form an arranged structure. Furthermore, if the size of the dichroic material's arrangement structure is too large (or there are too many of them), light is scattered and contrast decreases. Conversely, if the size of the dichroic material's arrangement structure is too small (or they are not formed or there are too few of them), lightfastness is thought to be low. Therefore, the inventors speculate that by having the arrangement structure within the above range, an optically anisotropic film with high contrast and good light resistance was obtained.

[0013] [Vertical orientation] As described above, the optically anisotropic film of the present invention has crystalline compounds that are vertically oriented. Furthermore, in the optical anisotropic film of the present invention, it is preferable that the dichroic material is also vertically oriented along the liquid crystalline compound. Here, vertical orientation refers to the fact that the molecular axis of the liquid crystalline compound (for example, the long axis in the case of a rod-shaped liquid crystalline compound) is perpendicular to the main plane of the optically anisotropic film. However, it does not require strict perpendicularity, but rather means that the inclination angle between the average molecular axis of the liquid crystalline compound in the optically anisotropic film and the main plane of the optically anisotropic film is less than 90 ± 10 degrees. The above tilt angle can be measured using the AxoScan OPMF-1 (manufactured by OptoScience Co., Ltd.). Specifically, using an AxoScan OPMF-1 (OptoScience Co., Ltd.), the Mueller matrix of an optically anisotropic film at wavelength λ is measured at room temperature at 10-degree intervals from -50° to 50° pole angles. After removing the effects of surface reflection, the extinction coefficients ko[λ] (in-plane direction) and ke[λ] (thickness direction) are calculated by fitting the data to the following theoretical formulas that consider Snell's and Fresnel's equations. Unless otherwise specified, the wavelength λ is assumed to be 550 nm. k = -log(T) × λ / (4πd) Here, T represents the transmittance and d represents the thickness of the optically anisotropic film. By calculating the absorbance and dichromatic ratio in the in-plane and thickness directions from the calculated ko[λ] and ke[λ], it is possible to confirm whether or not the elements are vertically oriented.

[0014] [Sequence structure] As described above, the optically anisotropic film of the present invention has a dichroic material that forms an arranged structure. Here, the term "arrangement structure" refers to a state in which dichroic substances gather together to form aggregates within an optically anisotropic film, and within these aggregates, the molecules of the dichroic substances are arranged periodically. Furthermore, the arrangement structure may be formed solely of dichroic materials, or it may be formed of a liquid crystalline compound and a dichroic material. Furthermore, the arrangement structure may be formed from one type of dichroic substance, or it may be formed from multiple types of dichroic substances. Furthermore, the arrangement structure may consist of a mixture of materials formed from one type of dichroic substance and materials formed from other types of dichroic substances within the optically anisotropic film. Furthermore, if the optically anisotropic film contains multiple types of dichroic substances, all of the multiple types of dichroic substances contained in the optically anisotropic film may form an arranged structure, or some of the dichroic substances may form an arranged structure.

[0015] Figure 1 is a conceptual diagram showing an example of a state in which a first dichroic substance and a second dichroic substance form an arrangement structure. The optically anisotropic film P has molecules M of the first dichroic substance, molecules O of the second dichroic substance, and molecules L of a liquid crystalline compound. As shown in Figure 1, an aggregate G containing molecules M and O is formed, in which the long axes of molecules M and O are aligned in the same direction, and molecules M and O are arranged to be shifted by a period of width w. The arrangement structure formed from the first dichroic substance and the second dichroic substance is not limited to the arrangement structure shown in Figure 1. For example, as shown in Figure 2, molecules M and O may be arranged so that they are shifted by an angle a period.

[0016] Furthermore, as described above, in the optically anisotropic film of the present invention, when observed in cross-section with a scanning transmission electron microscope, the arrangement structure satisfying L ≥ 30 nm is found to be 40 μm long, where L is the length of the long axis and D is the length of the short axis. 2 More than 16 are observed per unit.

[0017] Figure 3 is a conceptual diagram showing a cross-section of an example of the optically anisotropic film of the present invention. In Figure 3, the areas shown in white represent the array structure. In the example shown in Figure 3, the array structure denoted by N is an example of an array structure that satisfies the condition L ≥ 30 nm.

[0018] In this invention, the observation of the cross-section using a scanning transmission electron microscope (hereinafter also abbreviated as "STEM") is specifically performed as follows. First, using an ultramicrotome, ultrathin sections with a thickness of 100 nm in the film thickness direction are prepared from the optically anisotropic film. Next, the ultrathin section is placed on a grid with a carbon support film for STEM observation. Subsequently, the grid is placed inside a scanning transmission electron microscope, and the cross-section is observed using an electron beam acceleration voltage of 30kV.

[0019] Furthermore, the length L of the major axis and the length D of the minor axis of the array structure are measured specifically as follows. First, as described above, the cross-section of the optically anisotropic film is observed using STEM, and the captured images are analyzed to create a frequency histogram. The frequency at which the frequency is maximized and the standard deviation of the frequency distribution are determined. Next, a threshold is set at a frequency that is 1.3 times the standard deviation on the darker side from the frequency at which the frequency is maximized. Then, an image is created by binarizing the brightness using this threshold, and the portion of the binarized dark region with a major axis of 30 nm or more is extracted as the array structure. Furthermore, each extracted sequence structure is approximated by an ellipse, and the length of the major axis of the approximated ellipse is defined as the major axis length L of the sequence structure, and the length of the minor axis of the approximated ellipse is defined as the minor axis length D of the sequence structure. In addition, the angle between the axis perpendicular to the film surface (normal direction of the optically anisotropic film) and the major axis of the approximated ellipse is defined as the angle between the major axis of the sequence structure and the normal direction of the optically anisotropic film. The length L of the long axis and the length D of the short axis of such an array structure can be measured using known image processing software. For example, the image processing software "ImageJ" can be used.

[0020] As described above, the optical anisotropic film of the present invention has an array structure where L ≥ 30 nm, with L being the length of the long axis and D being the length of the short axis, and the array structure satisfying L ≥ 30 nm is 40 μm. 2 Each unit has 16 or more units, preferably 20 to 100 units, and more preferably 30 to 80 units. Specifically, by performing the image analysis described above, we selected arbitrary, non-overlapping 13.58 μm areas. 2 Three locations in this area (total 40 μm) 2In , an array structure satisfying L≥30 nm is extracted and counted. The counting of such an array structure is performed at 10 arbitrarily selected non-overlapping regions of 40 μm 2 (13.58 μm 2 ×3). Then, the average value of the number of array structures at the 10 measured locations is calculated, and this average value is taken as the number per 40 μm of the array structure satisfying L≥30 nm. 2 In actuality, the measurement is performed in a region of 13.58 μm 2 ×3 = 40.74 μm 2 However, in the present invention, for convenience, the fractional part is truncated and it is referred to as "per 40 μm" 2 .

[0021] In the present invention, due to the reason that the contrast of the optically anisotropic film becomes higher, it is preferable that less than 3 array structures satisfying L≥240 nm are observed per 40 μm, more preferably less than 1 is observed, and still more preferably none is observed. 2

[0022] Further, in the present invention, due to the reason that the contrast of the optically anisotropic film becomes higher and the light resistance is further improved, the ratio of the number of array structures in which the angle formed by the major axis of the array structure and the normal direction of the optically anisotropic film is 20° or more is preferably 28.0% or more, more preferably 50.0% or more, and still more preferably 70.0% or more.

[0023] <Aggregate> In the present invention, in the array structure, it is preferable that the dichroic substance forms an aggregate. By forming an aggregate, there is an advantage that the contrast of the optically anisotropic film becomes higher and the light resistance is further improved.

[0024] As a method for verifying that the dichroic substance forms an aggregate, for example, a method of comparing the maximum absorption wavelength measured using the formed film with the maximum absorption wavelength of the solution can be mentioned.

[0025] A specific method for measuring the maximum absorption wavelength using the formed film is to create a thick (10 μm or more) vertically oriented film, cut this film, and measure the absorption spectrum of its cross-section using an instrument such as the MSV-5200 (manufactured by JASCO Corporation). Another method for measuring the maximum absorption wavelength using the formed film is to create a film using the composition for forming the optically anisotropic film of the present invention, in the same manner as the optically anisotropic film of the present invention except that the film is not oriented, and then measure the absorption spectrum of that film. Methods for not oriented the composition for forming the optically anisotropic film include controlling the orientation by adjusting the presence and amount of the aligning agent or interface modifier described later, or by adding or changing the aligning film described later. Here, the maximum absorption wavelength of the solution can be considered to be the maximum absorption wavelength of the dichroic substance alone (without interaction between dichroic substances) when the solution is sufficiently diluted. On the other hand, if the maximum absorption wavelength measured using a film differs from the maximum absorption wavelength of the solution, it is considered that the dichroic substance is interacting with other substances (i.e., forming aggregates).

[0026] Specifically, the maximum absorption wavelength λs in the absorption spectrum of a solution containing a dichroic substance is determined. In this case, the concentration of the diluted solution is preferably 3.0% or less, and more preferably 2.0% or less. Next, a liquid crystal composition containing at least a liquid crystalline compound and a dichroic substance is cast onto a substrate (e.g., blue glass plate), and a film F for measuring the maximum absorption wavelength is formed by heating, curing, and ultraviolet irradiation in the same manner as for the optically anisotropic film of the present invention. The absorption spectrum of film F is then measured at 0.5 nm intervals in the wavelength range of 380 to 800 nm to determine the maximum absorption wavelength λf. Since the above-mentioned λs and λf satisfy the following equation (D), it can be seen that the dichroic substances form aggregates in the arrangement structure for the following reasons. |λs-λf| ≥ 2.0nm (D) In other words, the absorption spectrum of a solution containing a dichroic substance is understood to be the absorption spectrum of a single molecule of the dichroic substance. Therefore, if the maximum absorption wavelength λs of this absorption spectrum and the maximum absorption wavelength λf of the absorption spectrum of film F satisfy equation (D) above, it can be said that the maximum absorption wavelength is shifted due to the association of the dichroic substance within film F.

[0027] <Crystal structure> In the present invention, it is preferable that the dichroic material forms a crystalline structure in the arrangement structure. The formation of a crystalline structure has the advantage of increasing the contrast of the optically anisotropic film and improving its light resistance.

[0028] One method for verifying that dichroic materials form a crystalline structure is, for example, a method based on X-ray diffraction (XRD) spectra measured using optically anisotropic films. In the following explanation, when manufacturing each film (optically anisotropic film) whose XRD spectrum is compared, care should be taken to ensure that the film area and film thickness are the same, except for changing the type of dichroic substance contained in each film, by keeping the type of underlying layer (e.g., substrate), the concentration of the composition, and the coating conditions the same.

[0029] Specifically, X-ray diffraction analysis of optically anisotropic films is performed using the in-plane method. In the following, X-ray diffraction analysis performed using the in-plane method will also be referred to as "in-plane XRD." In-plane XRD shall be performed by irradiating the polarizer layer surface with X-rays using a thin-film X-ray diffractometer. Using a suitable in-plane direction as a reference, in-plane XRD is performed in all directions at 15° intervals, and the orientation in the substrate plane where the peak intensity is maximized is determined by a φ scan performed on the observed peaks. Using the in-plane measurement spectrum at the obtained orientation, it is possible to verify that the dichroic material forms a crystalline structure by comparing the XRD spectra of a film with the alignment film described later and a film with the optical anisotropy film of the present invention laminated on the alignment film, and by comparing the XRD spectra of a film with the dichroic material described later removed from the optical anisotropy film of the present invention and a film with the optical anisotropy film of the present invention laminated on it.

[0030] The optical anisotropic film of the present invention preferably has a front-facing transmittance of 65% or more, more preferably 70% or more, and even more preferably 75% or more. This increases the illumination of the image display device, thereby improving visibility.

[0031] Furthermore, in order to achieve a neutral color in the front direction, it is preferable that the optical anisotropic film of the present invention satisfies a degree of orientation of 0.93 or higher at 420 nm. The color control of optical films containing dichroic substances is usually achieved by adjusting the amount of dichroic substance added to the film. However, it was found that achieving a neutral color in both the frontal and oblique directions cannot be done by adjusting the amount of dichroic substance added alone. It was discovered that the reason why the color in both the frontal and oblique directions could not be made neutral was the low degree of orientation at 420 nm, and that by increasing the degree of orientation at 420 nm, the color in both the frontal and oblique directions could be made neutral.

[0032] [Liquid crystal composition] The optically anisotropic film of the present invention can be formed using a liquid crystal composition containing a liquid crystal compound and a dichroic substance. Furthermore, the liquid crystal composition may contain a solvent, a polymerization initiator, an interface modifier, an alignment agent, and other components. The following explains each component.

[0033] <Liquid crystal compounds> The liquid crystal composition contains a liquid crystalline compound. By including a liquid crystalline compound, the precipitation of dichroic substances can be suppressed while the dichroic substances can be oriented with a high degree of orientation. Liquid crystalline compounds are liquid crystalline compounds that do not exhibit dichroism. Both low-molecular-weight liquid crystalline compounds and high-molecular-weight liquid crystalline compounds can be used as liquid crystalline compounds, but high-molecular-weight liquid crystalline compounds are more preferable for obtaining a high degree of orientation. Here, "low-molecular-weight liquid crystalline compound" refers to a liquid crystalline compound that does not have repeating units in its chemical structure. "High-molecular-weight liquid crystalline compound" refers to a liquid crystalline compound that has repeating units in its chemical structure. Examples of low-molecular-weight liquid crystalline compounds include the liquid crystalline compounds described in Japanese Patent Publication No. 2013-228706. Examples of polymeric liquid crystalline compounds include the thermotropic liquid crystalline polymer described in Japanese Patent Publication No. 2011-237513. Furthermore, the polymeric liquid crystalline compound may have crosslinkable groups (e.g., acryloyl groups and methacryloyl groups) at its terminals. Liquid crystalline compounds may be used individually or in combination of two or more. The liquid crystalline compound preferably includes a polymer liquid crystalline compound because it exhibits a superior degree of orientation of the optically anisotropic film.

[0034] The liquid crystalline compound is preferably a polymer liquid crystalline compound containing a repeating unit represented by the following formula (3-1) (hereinafter also referred to as "repeating unit (3-1)"), because it exhibits a superior degree of orientation of the dichroic substance.

[0035] [ka]

[0036] In formula (3-1) above, P1 represents the repeating main chain, L1 represents a single bond or a divalent linking group, SP1 represents a spacer group, M1 represents a mesogenic group, and T1 represents a terminal group.

[0037] In the repeating unit (3-1), it is preferable that the difference between the logP values ​​of P1, L1, and SP1 and the logP value of M1 is 4 or more. More preferably, it is 4.5 or more. Since the logP values ​​of the main chain, L1, and spacer groups and the log value of the mesogenic group are separated by a predetermined value or more, the compatibility between the structure from the main chain to the spacer group and the mesogenic group is low. This is presumed to increase the crystallinity of the polymeric liquid crystalline compound and increase the degree of orientation of the polymeric liquid crystalline compound. Thus, it is presumed that a high degree of orientation of the polymeric liquid crystalline compound reduces the compatibility between the polymeric liquid crystalline compound and the dichroic substance (i.e., the crystallinity of the dichroic substance improves), and the degree of orientation of the dichroic substance improves. As a result, it is thought that the degree of orientation of the resulting optically anisotropic film will be high.

[0038] Specifically, the main chain of the repeating unit represented by P1 can be, for example, a group represented by the following formulas (P1-A) to (P1-D), and among these, the group represented by the following formula (P1-A) is preferred from the viewpoint of the diversity of monomers used as raw materials and ease of handling.

[0039] [ka]

[0040] In equations (P1-A) to (P1-D), "*" represents the bonding position with L1 in equation (3-1). In the above equations (P1-A) to (P1-D), R 1 , R 2 , R 3 and R 4 Each of these independently represents a hydrogen atom, a halogen atom, a cyano group, or a C1-C10 alkyl group, or a C1-C10 alkoxy group. The alkyl group may be a linear or branched alkyl group, or a cyclic alkyl group (cycloalkyl group). The number of carbon atoms in the alkyl group is preferably 1 to 5. The group represented by the above formula (P1-A) is preferably a unit of the partial structure of a poly(meth)acrylic acid ester obtained by polymerization of (meth)acrylic acid esters. The group represented by the above formula (P1-B) is preferably an ethylene glycol unit formed by ring-opening polymerization of the epoxy group of a compound having an epoxy group. The group represented by the above formula (P1-C) is preferably a propylene glycol unit formed by ring-opening polymerization of the oxetane group of a compound having an oxetane group. The group represented by the above formula (P1-D) is preferably a siloxane unit of a polysiloxane obtained by condensation polymerization of a compound having at least one of an alkoxysilyl group and a silanol group. Here, the compound having at least one of an alkoxysilyl group and a silanol group is a compound of the formula SiR 14 (OR 15 Examples include compounds having a group represented by )2-. In the formula, R 14 R in (P1-D) 14 It is synonymous with multiple R 15 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

[0041] L1 is a single bond or a divalent linking group. The divalent linking groups represented by L1 include -C(O)O-, -OC(O)-, -O-, -S-, and -C(O)NR 3 -, -NR 3 C(O)-, -SO2-, and -NR 3 R 4 - are some examples. In the formula, R 3 and R 4 Each of these independently represents a hydrogen atom or a C1-C6 alkyl group which may have substituents (described later). When P1 is a group represented by formula (P1-A), L1 is preferably a group represented by -C(O)O- because it results in a better degree of orientation of the optically anisotropic film. When P1 is a group represented by formulas (P1-B) to (P1-D), L1 is preferably a single bond because it results in a better degree of orientation of the optically anisotropic film.

[0042] The spacer group represented by SP1 preferably includes at least one structure selected from the group consisting of oxyethylene structure, oxypropylene structure, polysiloxane structure, and fluorinated alkylene structure, due to reasons such as its tendency to exhibit liquid crystalline properties and the availability of raw materials. Here, the oxyethylene structure represented by SP1 is *-(CH2-CH2O) n1 A group represented by -* is preferred. In the formula, n1 represents an integer from 1 to 20, and * represents the bonding position with L1 or M1 in formula (3-1) above. n1 is preferably an integer from 2 to 10, more preferably an integer from 2 to 4, and most preferably 3, because it provides a better degree of orientation of the optically anisotropic film. Furthermore, the oxypropylene structure represented by SP1 is *-(CH(CH3)-CH2O) because it provides a superior degree of orientation for optically anisotropic films. n2 A base represented by -* is preferred. In the formula, n2 represents an integer from 1 to 3, and * represents the bonding position with L1 or M1. Furthermore, the polysiloxane structure represented by SP1 is *-(Si(CH3)2-O) because it provides a superior degree of optical anisotropy in the orientation of the film. n3 A base represented by -* is preferred. In the formula, n3 represents an integer between 6 and 10, and * represents the bonding position with L1 or M1. Furthermore, the alkylene fluoride structure represented by SP1 is *-(CF2-CF2) because it provides a superior degree of orientation for optically anisotropic films. n4 A base represented by -* is preferred. In the formula, n4 represents an integer between 6 and 10, and * represents the bonding position with L1 or M1.

[0043] The mesogenic group represented by M1 is the group that represents the main skeleton of liquid crystal molecules that contribute to liquid crystal formation. Liquid crystal molecules exhibit liquid crystalline properties, which is an intermediate state (mesophase) between the crystalline state and the isotropic liquid state. There are no particular restrictions on the mesogenic group; for example, refer to the description in "Flussige Kristalle in Tabellen II" (VEB Deutsche Verlag fur Grundstoff Industrie, Leipzig, 1984), especially pages 7 to 16, and the description in the Liquid Crystal Handbook (Maruzen, 2000), edited by the Liquid Crystal Handbook Editorial Committee, especially Chapter 3. As the mesogenic group, a group having at least one cyclic structure selected from the group consisting of aromatic hydrocarbon groups, heterocyclic groups, and alicyclic groups is preferred. The mesogenic group preferably has aromatic hydrocarbon groups, more preferably has 2 to 4 aromatic hydrocarbon groups, and even more preferably has 3 aromatic hydrocarbon groups, because it provides a better degree of orientation of the optically anisotropic film.

[0044] As for the mesogenic group, a group represented by the following formula (M1-A) or (M1-B) is preferred, and the group represented by formula (M1-B) is more preferred, from the viewpoint of exhibiting liquid crystalline properties, adjusting the liquid crystal phase transition temperature, availability of raw materials, and suitability for synthesis, as well as because it provides a superior degree of orientation of the optically anisotropic film.

[0045] [ka]

[0046] In formula (M1-A), A1 is a divalent group selected from the group consisting of aromatic hydrocarbon groups, heterocyclic groups, and alicyclic groups. These groups may be substituted with alkyl groups, alkyl fluoride groups, alkoxy groups, or substituents. The divalent group represented by A1 is preferably a 4- to 6-membered ring. Furthermore, the divalent group represented by A1 may be a monoring or a fused ring. * indicates the binding site with SP1 or T1.

[0047] Examples of the divalent aromatic hydrocarbon group represented by A1 include phenylene, naphthylene, fluorene-diyl, anthracene-diyl, and tetracene-diyl groups. From the viewpoint of the diversity of mesogenic skeleton design and the availability of raw materials, a phenylene or naphthylene group is preferred, with a phenylene group being more preferred.

[0048] The divalent heterocyclic group represented by A1 may be either aromatic or non-aromatic, but from the viewpoint of improving the degree of orientation, it is preferable that it be a divalent aromatic heterocyclic group. Atoms other than carbon that constitute a divalent aromatic heterocyclic group include nitrogen, sulfur, and oxygen atoms. If an aromatic heterocyclic group has multiple atoms other than carbon that constitute the ring, these may be the same or different. Specific examples of divalent aromatic heterocyclic groups include, for example, pyridylene (pyridine-diyl group), pyridazine-diyl group, imidazole-diyl group, thienylene (thiophene-diyl group), quinolylene (quinoline-diyl group), isoquinolylene (isoquinoline-diyl group), oxazole-diyl group, thiazole-diyl group, oxadiazole-diyl group, benzothiazole-diyl group, benzothiadiazole-diyl group, phthalimide-diyl group, thienothiazole-diyl group, thiazolothiazole-diyl group, thienothiophene-diyl group, and thienoxazole-diyl group.

[0049] Specific examples of the divalent alicyclic group represented by A1 include the cyclopentylene group and the cyclohexylene group.

[0050] In equation (M1-A), a1 represents an integer between 1 and 10. If a1 is 2 or greater, multiple A1s may be the same or different.

[0051] In formula (M1-B), A2 and A3 are each independently divalent groups selected from the group consisting of aromatic hydrocarbon groups, heterocyclic groups, and alicyclic groups. Specific examples and preferred embodiments of A2 and A3 are the same as those for A1 in formula (M1-A), so their explanation is omitted. In formula (M1-B), a2 represents an integer from 1 to 10. When a2 is 2 or greater, multiple A2s may be the same or different, multiple A3s may be the same or different, and multiple LA1s may be the same or different. a2 is preferably an integer of 2 or greater, and more preferably 2, because it results in a better degree of orientation of the optically anisotropic film. In formula (M1-B), when a2 is 1, LA1 is a divalent linking group. When a2 is 2 or more, each of the multiple LA1s is independently either a single bond or a divalent linking group, and at least one of the multiple LA1s is a divalent linking group. When a2 is 2, it is preferable that one of the two LA1s is a divalent linking group and the other is a single bond, for a better degree of orientation of the optically anisotropic film.

[0052] In formula (M1-B), the divalent linking group represented by LA1 is -O-, -(CH2) g -,-(CF2) g -, -Si(CH3)2-, -(Si(CH3)2O) g -,-(OSi(CH3)2) g -(g represents an integer from 1 to 10.), -N(Z)-, -C(Z)=C(Z')-, -C(Z)=N-, -N=C(Z)-, -C(Z)2-C(Z')2-, -C(O)-, -OC(O)-, -C(O)O-, -OC(O)O-, -N(Z) C(O)-, -C(O)N(Z)-, -C(Z)=C(Z')-C(O)O-, -OC(O)-C(Z)=C(Z')-, -C(Z)=N-, -N=C(Z)-, -C(Z)=C(Z')-C(O)N(Z'')-, -N(Z'')-C(O Examples include -C(Z)=C(Z')-, -C(Z)=C(Z')-C(O)-S-, -SC(O)-C(Z)=C(Z')-, -C(Z)=NN=C(Z')- (where Z, Z', and Z'' independently represent hydrogen, a C1-C4 alkyl group, a cycloalkyl group, an aryl group, a cyano group, or a halogen atom), -C≡C-, -N=N-, -S-, -S(O)-, -S(O)(O)-, -(O)S(O)O-, -O(O)S(O)O-, -SC(O)-, and -C(O)S-. Among these, -C(O)O- is preferred because it provides a superior degree of orientation for the optically anisotropic film. LA1 may be a group formed by combining two or more of these groups.

[0053] An example of M1 is the following structure. In the example below, "Ac" represents an acetyl group.

[0054] [ka] [ka] [ka]

[0055] [ka] [ka] [ka] [ka]

[0056] Examples of terminal groups represented by T1 include hydrogen atoms, halogen atoms, cyano groups, nitro groups, hydroxyl groups, C1-C10 alkyl groups, C1-C10 alkoxy groups, C1-C10 alkylthio groups, C1-C10 alkoxycarbonyloxy groups, C1-C10 alkoxycarbonyl groups (ROC(O)-: R is an alkyl group), C1-C10 acyloxy groups, C1-C10 acylamino groups, C1-C10 alkoxycarbonylamino groups, C1-C10 sulfonylamino groups, C1-C10 sulfamoyl groups, C1-C10 carbamoyl groups, C1-C10 sulfinyl groups, and C1-C10 ureido groups and (meth)acryloyloxy group-containing groups. Examples of the (meth)acryloyloxy group-containing groups mentioned above include the group represented by -LA (where L represents a single bond or a linking group; specific examples of linking groups are the same as those for L1 and SP1 above; A represents a (meth)acryloyloxy group). T1 is preferably an alkoxy group having 1 to 10 carbon atoms, more preferably an alkoxy group having 1 to 5 carbon atoms, and even more preferably a methoxy group, because it provides a better degree of orientation of the optically anisotropic film. These terminal groups may be further substituted with these groups or with polymerizable groups described in Japanese Patent Application Publication No. 2010-244038. The number of atoms in the main chain of T1 is preferably 1 to 20, more preferably 1 to 15, even more preferably 1 to 10, and particularly preferably 1 to 7, for the reason that it results in a better degree of orientation of the optically anisotropic film. The degree of orientation of the optically anisotropic film is further improved when the number of atoms in the main chain of T1 is 20 or less. Here, "main chain" in T1 refers to the longest molecular chain bonded to M1, and hydrogen atoms are not counted in the number of atoms in the main chain of T1. For example, if T1 is an n-butyl group, the number of atoms in the main chain is 4, and if T1 is a sec-butyl group, the number of atoms in the main chain is 3.

[0057] The content of repeating units (3-1) is preferably 20 to 100% by mass relative to 100% by mass of the total repeating units of the polymeric liquid crystalline compound, because this results in a superior degree of orientation of the optically anisotropic film. In this invention, the content of each repeating unit in the polymeric liquid crystalline compound is calculated based on the amount (mass) of each monomer used to obtain each repeating unit. The repeating unit (3-1) may be present alone or in combination of two or more types in the polymeric liquid crystalline compound. When the polymeric liquid crystalline compound contains two or more types of repeating units (3-1), there are advantages such as improved solubility of the polymeric liquid crystalline compound in the solvent and easier adjustment of the liquid crystal phase transition temperature. When two or more types of repeating units (3-1) are present, it is preferable that their total amount is within the above range.

[0058] When a polymeric liquid crystalline compound contains two types of repeating units (3-1), it is preferable that the terminal group represented by T1 in one repeating unit (repeating unit A) is an alkoxy group, and the terminal group represented by T1 in the other repeating unit (repeating unit B) is a group other than an alkoxy group, for the reason that the degree of orientation of the optically anisotropic film is superior. In the repeating unit B described above, the terminal group represented by T1 is preferably an alkoxycarbonyl group, a cyano group, or a (meth)acryloyloxy group-containing group, and more preferably an alkoxycarbonyl group or a cyano group, because it provides a better degree of orientation of the optically anisotropic film. The ratio (A / B) of the content of repeating unit A in the polymeric liquid crystalline compound to the content of repeating unit B in the polymeric liquid crystalline compound is preferably 50 / 50 to 95 / 5, more preferably 60 / 40 to 93 / 7, and even more preferably 70 / 30 to 90 / 10, for the reason that it results in a better degree of orientation of the optically anisotropic film.

[0059] <Repeating Unit (3-2)> The polymeric liquid crystalline compound of the present invention may further contain a repeating unit represented by the following formula (3-2) (hereinafter also referred to as "repeating unit (3-2)"). This offers advantages such as improved solubility of the polymeric liquid crystalline compound in solvents and easier adjustment of the liquid crystal phase transition temperature. The repeating unit (3-2) differs from the repeating unit (3-1) in that it does not have at least a mesogenic group. If the polymeric liquid crystalline compound contains repeating units (3-2), the polymeric liquid crystalline compound is a copolymer of repeating units (3-1) and (3-2) (and may also be a copolymer containing repeating units A and B), and may be any polymer such as a block polymer, an alternating polymer, a random polymer, or a graft polymer.

[0060] [ka]

[0061] In formula (3-2), P3 represents the repeating main chain, L3 represents a single bond or a divalent linking group, SP3 represents a spacer group, and T3 represents a terminal group. The specific examples of P3, L3, SP3, and T3 in equation (3-2) are the same as those of P1, L1, SP1, and T1 in equation (3-1) above. Here, in formula (3-2), T3 preferably has a polymerizable group from the viewpoint of improving the strength of the optically anisotropic film.

[0062] When repeating units (3-2) are present, the content is preferably 0.5 to 40% by mass, and more preferably 1 to 30% by mass, relative to 100% by mass of the total repeating units of the polymeric liquid crystalline compound. The repeating unit (3-2) may be present alone or in combination of two or more types in the polymeric liquid crystalline compound. When two or more types of repeating units (3-2) are present, it is preferable that their total amount is within the above range.

[0063] (Weight average molecular weight) The weight-average molecular weight (Mw) of the polymeric liquid crystalline compound is preferably between 1,000 and 500,000, and more preferably between 2,000 and 300,000, because it results in a superior degree of orientation of the optically anisotropic film. If the Mw of the polymeric liquid crystalline compound is within the above range, the polymeric liquid crystalline compound becomes easier to handle. In particular, from the viewpoint of suppressing cracks during coating, the weight-average molecular weight (Mw) of the polymeric liquid crystalline compound is preferably 10,000 or more, and more preferably between 10,000 and 300,000. Furthermore, from the viewpoint of the temperature latitude of the degree of orientation, the weight-average molecular weight (Mw) of the polymeric liquid crystalline compound is preferably less than 10,000, and preferably between 2,000 and less than 10,000. Here, the weight-average molecular weight and number-average molecular weight in this invention are values ​​measured by gel permeation chromatography (GPC). • Solvent (eluent): N-methylpyrrolidone ·Device name: TOSOH HLC-8220GPC • Column: Three TOSOH TSKgelSuperAWM-H (6mm x 15cm) columns connected together are used. • Column temperature: 25℃ • Sample concentration: 0.1% by mass ·Flow rate: 0.35mL / min • Calibration curve: A calibration curve was used based on 7 samples of TOSOH TSK standard polystyrene with Mw=2,800,000 to 1,050 (Mw / Mn=1.03 to 1.06).

[0064] (Content of liquid crystalline compounds) The content of the liquid crystalline compound is preferably 30 to 99% by mass, more preferably 50 to 98% by mass, and particularly preferably 60 to 95% by mass, based on the total solid content mass of the liquid crystal composition. Having the liquid crystalline compound content within the above range further improves the degree of orientation of the optically anisotropic film. Preferably, the content of the liquid crystalline compound in the optical anisotropic film relative to the total mass of the optical anisotropic film is the same as the content of the liquid crystalline compound relative to the total solid content mass of the liquid crystal composition described above.

[0065] <Dichroic substances> The liquid crystal composition further contains a dichroic substance. In this invention, a dichroic substance refers to a dye whose absorbance differs depending on the direction. The dichroic substance may or may not exhibit liquid crystalline properties.

[0066] Dichroic materials are not particularly limited and include visible light absorbing materials (dichroic dyes), luminescent materials (fluorescent materials, phosphorescent materials), ultraviolet absorbing materials, infrared absorbing materials, nonlinear optical materials, carbon nanotubes, and inorganic materials (e.g., quantum rods). Conventionally known dichroic materials (dichroic dyes) can be used. Specifically, for example, Japanese Patent Publication No. 2013-228706

[0067] ~

[0071] paragraph, paragraphs

[0008] ~

[0026] of JP 2013-227532, paragraphs

[0008] ~

[0015] of JP 2013-209367, paragraphs

[0045] ~

[0058] of JP 2013-14883, paragraphs

[0012] ~

[0029] of JP 2013-109090, paragraphs

[0009] ~

[0017] of JP 2013-101328, paragraphs

[0051] ~

[0065] of JP 2013-37353, paragraphs

[0049] ~

[0073] of JP 2012-63387, Paragraphs

[0016] to

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

[0009] to

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

[0030] to

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

[0021] to

[0075] of JP-A-2010-106242, paragraphs

[0011] to

[0025] of JP-A-2010-215846, paragraphs

[0017] to

[0069] of JP-A-2011-048311, paragraphs

[0013] to

[0133] of JP-A-2011-213610, and JP-A-2011-2375 Paragraphs

[0074] to

[0246] of Japanese Patent Publication No. 13, paragraphs

[0005] to

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

[0014] to

[0032] of Japanese Patent Publication No. 2018-053167, paragraphs

[0014] to

[0033] of Japanese Patent Publication No. 2020-11716, 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, and International Publication No. 2017 / 15469 Examples include paragraphs

[0014] to

[0033] of Issue 5, paragraphs

[0013] to

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

[0014] to

[0034] of International Publication No. 2018 / 164252, 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, and paragraphs

[0050] to

[0074] of International Publication No. 2020 / 004106.

[0067] Furthermore, the following are specific examples of dichroic substances.

[0068] [ka]

[0069] [ka]

[0070] [ka]

[0071] In the present invention, two or more dichroic materials may be used in combination. For example, from the viewpoint of making the formed optically anisotropic film closer to black, it is preferable to use in combination at least one dichroic material having a maximum absorption wavelength in the range of 370 to 550 nm and at least one dichroic material having a maximum absorption wavelength in the range of 500 to 700 nm.

[0072] The content of the dichroic substance is preferably 7 to 70% by mass, more preferably 10 to 60% by mass, and even more preferably 13 to 50% by mass, relative to the total solid content (100% by mass) of the liquid crystal composition, in order to achieve the best effect of the present invention. When multiple dichroic substances are used in combination, it is preferable that the total amount of the multiple dichroic substances is within the above range.

[0073] <Solvent> From the viewpoint of workability and other factors, the liquid crystal composition preferably contains a solvent. As solvents, for example, 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 acetoethyl acetate, n-pentyl acetate, ethyl benzoate, benzyl benzoate, butyl carbitol acetate, diethylene glycol monoethyl ether acetate) Organic solvents such as ethanol (e.g., isoamyl acetate), alcohols (e.g., 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, etc.), phenols (e.g., phenol, cresol, etc.), cellosolves (e.g., methyl cellosolve, ethyl cellosolve, and 1,2-dimethoxyethane, etc.), cellosolve acetates, sulfoxides (e.g., dimethyl sulfoxide, etc.), amides (e.g., dimethylformamide and 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 individually or in combination of two or more.

[0074] Furthermore, as a solvent, it is preferable that the boiling point is 70°C or higher, more preferably 125°C or higher, and even more preferably 180°C or higher, because this facilitates the formation of an arranged structure of the two-color substances, resulting in higher contrast in the formed optically anisotropic film and improved lightfastness. Furthermore, when two or more solvents are used in combination, it is preferable to include a solvent with a boiling point of 70°C or higher, more preferably a solvent with a boiling point of 125°C or higher, and particularly preferable a solvent with a boiling point of 180°C or higher. Furthermore, when using two or more solvents in combination, it is preferable to use a solvent with a boiling point below 180°C and a solvent with a boiling point of 180°C or higher. The mass ratio of the total amount of the solvent with a boiling point below 180°C and the solvent with a boiling point of 180°C or higher is preferably 1:1 to 30:1, more preferably 2:1 to 20:1, and even more preferably 3:1 to 15:1. Although the reason why using the above boiling point makes it easier for the dichroic substance to form an arranged structure is not clear, the inventors of this invention speculate as follows. First, the arrangement structure of dichroic substances is thought to be formed when crystalline compounds become liquid crystals and align within an optically anisotropic film, with the dichroic substances moving within the film. Therefore, it is hypothesized that if a solvent with a high boiling point is included, the solvent is more likely to remain, making it easier for the dichroic substances to move within the film, and as a result, easier formation of the arrangement structure.

[0075] Of these solvents, organic solvents are preferred because they facilitate the adjustment of the length L of the long axis of the arrangement structure, resulting in higher contrast of the formed optically anisotropic film and improved light resistance. It is more preferable to use at least one organic solvent with a boiling point of 140°C or higher (high-boiling point solvent). There is no particular upper limit to the boiling point of the high-boiling point solvent, but it is usually 300°C or lower, and preferably 250°C or lower. As high-boiling point solvents, it is preferable to use the ketones, aromatic hydrocarbons, halogenated carbons, esters, alcohols, cellosolves, sulfoxides, heterocyclic compounds, and amides mentioned above, and more preferably xylene, tetralin, 1,1,2,2-tetrachloroethane, ethyl acetoacetate, n-pentyl acetate, isoamyl acetate, benzyl alcohol, acetylacetone, hexanol, octanol, furfuryl alcohol, 2-ethylhexanol, ethanolamine, ethylene glycol, propylene glycol, butylcarbitol acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether acetate, cyclohexanol, diethylene glycol, diethylene glycol monobutyl ether, ethyl benzoate, benzyl benzoate, dibutyl ether, phenol, cresol, dimethylacetamide, dimethylformamide, N-ethylpyrrolidone, dimethyl sulfoxide, pyridine, and 2,6-lutidine.

[0076] When the liquid crystal composition contains a solvent, the solvent content is preferably 60 to 99.5% by mass, more preferably 70 to 99% by mass, and particularly preferably 75 to 98% by mass, relative to the total mass (100% by mass) of the liquid crystal composition, because this results in a higher degree of orientation of the formed optically anisotropic film and improved heat resistance.

[0077] <Polymerization initiator> The liquid crystal composition may contain a polymerization initiator. There are no particular restrictions on the polymerization initiator, but it is preferable that it be a photosensitive compound, i.e., a photopolymerization initiator. Various compounds can be used as photopolymerization initiators without particular limitations. Examples of photopolymerization initiators include α-carbonyl compounds (US Patent Nos. 2,367,661 and 2,367,670), acyloin ethers (US Patent No. 2,448,828), α-hydrocarbon-substituted aromatic acyloin compounds (US Patent No. 2,722,512), polynuclear quinone compounds (US Patent Nos. 3,046,127 and 2,951,758), and combinations of triarylimidazole dimers and p-aminophenyl ketones (US Patent No. 3,549,367). Examples include acridine and phenazine compounds (Japanese Patent Publication No. 60-105667 and U.S. Patent No. 4239850), oxadiazole compounds (U.S. Patent No. 4212970), o-acyloxime compounds (Japanese Patent Publication No. 2016-27384

[0065] ), and acylphosphine oxide compounds (Japanese Patent Publication No. 63-40799, Japanese Patent Publication No. 5-29234, Japanese Patent Publication No. 10-95788 and Japanese Patent Publication No. 10-29997). Commercially available photopolymerization initiators can also be used, including BASF's Irgacure-184, Irgacure-907, Irgacure-369, Irgacure-651, Irgacure-819, Irgacure-OXE-01, and Irgacure-OXE-02.

[0078] When a liquid crystal composition contains a polymerization initiator, the amount of polymerization initiator is preferably 0.01 to 30% by mass, and more preferably 0.1 to 15% by mass, relative to the total solid content (100% by mass) of the liquid crystal composition, because this results in a higher degree of orientation of the formed optically anisotropic film and improved heat resistance.

[0079] <Polymerizable compound> The liquid crystal composition may contain polymerizable compounds. Examples of polymerizable compounds include compounds containing acrylates (for example, (meth)acrylate monomers).

[0080] When the liquid crystal composition contains a polymerizable compound, the polymerizable compound content is preferably 0.5 to 50% by mass, and more preferably 1.0 to 40% by mass, relative to the total solid content (100% by mass) of the liquid crystal composition, from the viewpoint of achieving superior effects of the present invention.

[0081] <Interface modifier> The liquid crystal composition preferably contains an interface modifier. By including an interface modifier, the smoothness of the coated surface is improved, the degree of orientation is enhanced, and repellency and unevenness are suppressed, resulting in improved uniformity within the surface. As the interface modifier, fluorine (meth)acrylate polymers described in sections

[0018] to

[0043] of Japanese Patent Publication No. 2007-272185 can be used. Other compounds may also be used as interface modifiers. The interface modifier may be used alone or in combination of two or more types. When the liquid crystal composition contains an interface modifier, the content of the interface modifier in the liquid crystal composition is preferably 0.1 to 2.0% by mass, and more preferably 0.1 to 1.0% by mass, based on the total solid content mass of the liquid crystal composition. When the optically anisotropic film contains an interface modifier, it is preferable that the content of the interface modifier relative to the total mass of the optically anisotropic film is the same as the content of the interface modifier relative to the total solid content mass of the liquid crystal composition.

[0082] <Orienting agent> The liquid crystal composition may contain an alignment agent. Specific examples of orientation agents include vertical orientation agents such as boronic acid compounds and onium salts.

[0083] As the boronic acid compound, the compound represented by formula (30) is preferred.

[0084] Formula (30) [ka]

[0085] In formula (30), R 1 and R 2Each of these independently represents a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group. R 3 This represents a substituent containing a (meth)acrylic group. Specific examples of boronic acid compounds include the boronic acid compounds represented by general formula (I) described in paragraphs 0023 to 0032 of Japanese Patent Publication No. 2008-225281. The following compounds are also preferred as boronic acid compounds.

[0086] [ka]

[0087] As the onium salt, the compound represented by formula (31) is preferred.

[0088] Formula (31) [ka]

[0089] In formula (31), ring A represents a quaternary ammonium ion consisting of a nitrogen-containing heterocycle. X represents an anion. 1 This represents a divalent linking group. 2 This represents a single bond or a divalent linking group. 1 represents a divalent linking group having a 5 or 6-membered ring as a substructure. Z represents a divalent linking group having 2 to 20 alkylene groups as a substructure. P 1 and P 2 Each of these independently represents a monovalent substituent having a polymerizable ethylenically unsaturated bond. Specific examples of onium salts include the onium salts described in paragraphs 0052 to 0058 of Japanese Patent Publication No. 2012-208397, the onium salts described in paragraphs 0024 to 0055 of Japanese Patent Publication No. 2008-026730, and the onium salts described in Japanese Patent Publication No. 2002-37777.

[0090] When the liquid crystal composition contains an alignment agent, the content of the alignment agent in the liquid crystal composition is preferably 0.1 to 40% by mass, and more preferably 0.3 to 20% by mass, based on the total solid content (100% by mass) of the liquid crystal composition. The orientation agent may be used alone or in combination of two or more types. When two or more orientation agents are used, it is preferable that their total amount is within the above range.

[0091] [Method for manufacturing optically anisotropic films] The method for producing the optically anisotropic film of the present invention is not particularly limited, but a method comprising the steps of applying the above-mentioned liquid crystal composition onto an alignment film to form a coating film (hereinafter also referred to as the "coating film formation step") and aligning the liquid crystal components contained in the above-mentioned coating film (hereinafter also referred to as the "alignment step") in this order (hereinafter also referred to as the "present production method") is preferred for the reason that the degree of orientation of the resulting optically anisotropic film is higher. Furthermore, liquid crystal components include not only the liquid crystalline compounds mentioned above, but also dichroic substances that possess liquid crystalline properties. The following describes each step.

[0092] <Coating film formation process> The coating film formation step is a step of forming a coating film by applying the above-mentioned liquid crystal composition onto the alignment film. The liquid crystal compounds in the coating film are vertically aligned through interaction with the alignment film and (if the liquid crystal composition contains a vertical alignment agent) with the vertical alignment agent. By using a liquid crystal composition containing the aforementioned solvent, or by using a liquid crystal composition that has been heated to a molten state, it becomes easier to coat the alignment film with the liquid crystal composition. Known methods for coating liquid crystal compositions include roll coating, gravure printing, spin coating, wire bar coating, extrusion coating, direct gravure coating, reverse gravure coating, die coating, spray coating, and inkjet coating.

[0093] (Orientation film) The alignment film can be any film that vertically aligns the liquid crystalline compounds contained in the liquid crystal composition. The orientation can be provided by means such as rubbing treatment of an organic compound (preferably a polymer) onto the film surface, oblique deposition of an inorganic compound, formation of a layer having microgrooves, or accumulation of an organic compound (e.g., ω-tricosanoic acid, dioctadecylmethylammonium chloride, methyl stearylate, etc.) by the Langmuir-Bludget method (LB film). Furthermore, orientation films that exhibit orientation function by applying an electric field, a magnetic field, or light irradiation are also known. Among these, in the present invention, orientation films formed by rubbing treatment are preferred in terms of ease of controlling the pre-tilt angle of the orientation film, and photo-alignment films formed by light irradiation are also preferred in terms of uniformity of orientation.

[0094] (1) Rubbing-treated orientation film Numerous polymer materials are described in various publications and many commercially available products can be used for the orientation film formed by the rubbing process. In this invention, polyvinyl alcohol or polyimide, and their derivatives, are preferably used. For the orientation film, refer to the description on pages 43, line 24 to 49, line 8 of International Publication No. 2001 / 88574A1. The thickness of the orientation film is preferably 0.01 to 10 μm, and more preferably 0.01 to 1 μm.

[0095] (2) Photoalignment film Numerous publications describe photo-alignment materials used in alignment films formed by light irradiation. In this invention, for example, azo compounds described in Japanese Patent Publication No. 2006-285197, Japanese Patent Publication No. 2007-76839, Japanese Patent Publication No. 2007-138138, Japanese Patent Publication No. 2007-94071, Japanese Patent Publication No. 2007-121721, Japanese Patent Publication No. 2007-140465, Japanese Patent Publication No. 2007-156439, Japanese Patent Publication No. 2007-133184, Japanese Patent Publication No. 2009-109831, Japanese Patent No. 3883848, Japanese Patent No. 4151746, and Japanese Patent Publication No. 2002-229039 are used. Preferred examples include aromatic ester compounds, maleimide and / or alkenyl-substituted nadiimide compounds having photo-orienting units as described in Japanese Patent Publication No. 2002-265541 and Japanese Patent Publication No. 2002-317013, photocrosslinkable silane derivatives as described in Japanese Patent No. 4205195 and Japanese Patent No. 4205198, Japanese Patent Publication No. 2003-520878 and Japanese Patent Publication No. 2004-529220, or photocrosslinkable polyimide, polyamide, or ester as described in Japanese Patent No. 4162850. More preferably are azo compounds, photocrosslinkable polyimide, polyamide, or ester.

[0096] A photo-alignment film is manufactured by irradiating a photo-alignment film formed from the above materials with linearly polarized or unpolarized light. In this specification, "linearly polarized irradiation" and "unpolarized irradiation" refer to operations for causing a photoreaction in a photo-oriented material. The wavelength of light used varies depending on the photo-oriented material used and is not particularly limited as long as it is the wavelength necessary for the photoreaction. The peak wavelength of the light used for irradiation is preferably 200 nm to 700 nm, and ultraviolet light with a peak wavelength of 400 nm or less is more preferred.

[0097] Light sources used for light irradiation include commonly used light sources such as lamps like tungsten lamps, halogen lamps, xenon lamps, xenon flash lamps, mercury lamps, mercury xenon lamps, and carbon arc lamps; various lasers [e.g., semiconductor lasers, helium-neon lasers, argon ion lasers, helium-cadmium lasers, and YAG (yttrium-aluminum-garnet) lasers]; light-emitting diodes; and cathode ray tubes.

[0098] Methods for obtaining linearly polarized light include using polarizers (e.g., iodine polarizers, dichroic polarizers, and wire grid polarizers), using prism-type elements (e.g., Grant-Thomson prisms) or reflective polarizers utilizing the Brewster angle, or using light emitted from a polarized laser light source. Alternatively, filters or wavelength conversion elements may be used to selectively irradiate only the light of the required wavelength.

[0099] When linearly polarized light is used, the light is irradiated from the top or back surface of the alignment film, perpendicular or oblique to the surface of the alignment film. The angle of incidence of the light varies depending on the photo-alignment material, but is preferably 0 to 90° (perpendicular), and preferably 40 to 90°. In the case of non-polarized light, the orientation film is irradiated with non-polarized light from an oblique angle. The incident angle is preferably 10 to 80°, more preferably 20 to 60°, and particularly preferably 30 to 50°. The irradiation time is preferably 1 to 60 minutes, and more preferably 1 to 10 minutes.

[0100] If patterning is required, a method can be employed in which light irradiation using a photomask is performed the number of times necessary to create the pattern, or a method can be employed in which the pattern is written by laser scanning.

[0101] <Orientation Process> The orientation step is a process of aligning the dichroic substance contained in the coated film. This yields the optically anisotropic film of the present invention. In the orientation step, it is believed that the dichroic substance is oriented along the liquid crystalline compound that has been oriented by the orientation film. The orientation step may include a drying process. The drying process can remove components such as solvents from the coating film. The drying process may be carried out by leaving the coating film at room temperature for a predetermined time (e.g., natural drying), or by heating and / or blowing air. Here, the dichroic substances contained in the liquid crystal composition may be oriented by the coating film formation process or drying process described above. For example, in embodiments in which the liquid crystal composition is prepared as a coating solution containing a solvent, drying the coating film to remove the solvent from the coating film may cause the dichroic substances contained in the coating film to be oriented, thereby obtaining the optical anisotropic film of the present invention.

[0102] The orientation step preferably includes a heat treatment. This further orientations the dichroic substances contained in the coating film, resulting in a higher degree of orientation of the resulting optically anisotropic film. The heat treatment is preferably performed at 10 to 250°C, and more preferably at 25 to 190°C, from the standpoint of suitability for manufacturing. The heating time is preferably 1 to 300 seconds, and more preferably 1 to 60 seconds.

[0103] The orientation step may include a cooling process performed after the heat treatment. The cooling process involves cooling the heated coating film to room temperature (approximately 20-25°C). This further fixes the orientation of the dichroic substances contained in the coating film, resulting in a higher degree of orientation of the resulting optically anisotropic film. The cooling method is not particularly limited and can be carried out by known methods. The optically anisotropic film of the present invention can be obtained through the above steps.

[0104] In the present invention, the technique for orienting a dichroic material in a desired direction can be based on techniques for fabricating polarizers using dichroic materials, or techniques for fabricating guest-host liquid crystal cells. For example, the techniques used in the method for fabricating a dichroic polarizing element described in Japanese Patent Publication No. 11-305036 and Japanese Patent Publication No. 2002-90526, and the techniques used in the method for fabricating a guest-host type liquid crystal display device described in Japanese Patent Publication No. 2002-99388 and Japanese Patent Publication No. 2016-27387 can also be used in the fabrication of the optically anisotropic film of the present invention. For example, by utilizing the technology of a guest-host liquid crystal cell, the dichroic material can be oriented to the desired orientation as described above in conjunction with the orientation of the host liquid crystal. Specifically, by mixing a guest dichroic material with a rod-shaped liquid crystalline compound that will serve as the host liquid crystal, oriented the host liquid crystal, and oriented the molecules of the dichroic material in accordance with the orientation of its liquid crystal molecules, thereby fixing the orientation state, the optical anisotropic film of the present invention can be fabricated.

[0105] In the present invention, in order to prevent variations in the light absorption properties of the optically anisotropic film depending on the usage environment, it is preferable to fix the orientation of the dichroic substance by forming chemical bonds. For example, the orientation can be fixed by promoting polymerization of the host liquid crystal, the dichroic substance, or a polymerizable component added as desired. Furthermore, by impregnating a polymer film with a dichroic substance and orienting the dichroic substance along the orientation of the polymer molecules in the polymer film, a polymer film that satisfies the light absorption characteristics required for the optically anisotropic film used in the present invention can be produced. Specifically, this can be done by coating a solution of the dichroic substance onto the surface of the polymer film and allowing it to penetrate the film. The orientation of the dichroic substance can be adjusted by the orientation of the polymer chains in the polymer film, their properties (chemical and physical properties of the polymer chains or the functional groups they possess), the coating method, etc. Details of this method are described in Japanese Patent Application Publication No. 2002-90526.

[0106] <Other processes> This manufacturing method may include a step of curing the optically anisotropic film (hereinafter also referred to as the "curing step") after the orientation step described above. The curing process is carried out, for example, by heating and / or light irradiation (exposure). Among these, it is preferable that the curing process be carried out by light irradiation. Various light sources can be used for curing, such as infrared light, visible light, or ultraviolet light, 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. Furthermore, exposure may be performed under a nitrogen atmosphere. When the curing of the optically anisotropic film proceeds by radical polymerization, exposure under a nitrogen atmosphere is preferable because it reduces the inhibition of polymerization by oxygen.

[0107] [Optical film] The optical film of the present invention comprises a transparent film substrate and the optically anisotropic film described above disposed on the transparent film substrate. Furthermore, the optical film of the present invention may have an alignment film between the transparent film substrate and the optically anisotropic film. Furthermore, the optical film of the present invention may also have a polarizer having an absorption axis in its plane. Preferably, the polarizer is positioned on the side opposite to the transparent substrate film of the optically anisotropic film. The polarizer may be positioned in contact with the surface of the optically anisotropic film, or it may be positioned on the surface of the optically anisotropic film via another layer (for example, a known adhesive layer or bonding layer). When the optical film of the present invention has the polarizer, it is preferable that the optical film of the present invention is a viewing angle control film used for controlling the viewing angle. The following describes each component that constitutes the optical film of the present invention.

[0108] [Transparent film substrate] As the transparent film substrate, known transparent resin films, transparent resin plates, transparent resin sheets, etc., can be used, and there are no particular limitations. As the transparent resin film, cellulose acylate film (e.g., cellulose triacetate film (refractive index 1.48), cellulose diacetate film, cellulose acetate butyrate film, cellulose acetate propionate film), polyethylene terephthalate film, polyethersulfone film, polyacrylic resin film, polyurethane resin film, polyester film, polycarbonate film, polysulfone film, polyether film, polymethylpentene film, polyetherketone film, (meth)acrylonitrile film, etc. can be used.

[0109] Among these, cellulose acylate film is preferred because it has high transparency, low optical birefringence, is easy to manufacture, and is commonly used as a protective film for polarizing plates, and cellulose triacetate film is particularly preferred. The thickness of the transparent film substrate is typically between 20 μm and 100 μm. In the present invention, it is particularly preferable that the transparent film substrate is a cellulose ester film and that its film thickness is 20 to 70 μm.

[0110] [Optical anisotropic film] As described above, the optical anisotropic film of the present invention will be omitted from further explanation.

[0111] [Orientation film] As explained above, the orientation layer will be omitted from this explanation.

[0112] [Barrier layer] The optical film of the present invention preferably has a barrier layer along with a transparent film substrate and a light-absorbing anisotropic layer. Here, the barrier layer is also called a gas barrier layer (oxygen barrier layer) and has the function of protecting the polarizing element of the present invention from gases such as oxygen in the atmosphere, moisture, or compounds contained in adjacent layers. For information regarding the barrier layer, see, for example, paragraphs

[0014] to

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

[0042] to

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

[0045] to

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

[0010] to

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

[0021] to

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

[0113] [Color adjustment layer] The optical film of the present invention preferably includes a color adjustment layer having at least one dye compound. The dye compound included in the color adjustment layer is preferably in an unoriented state. When the amount of dye in the light absorption anisotropy layer is adjusted, the change in color when viewed from oblique directions relative to the transmittance center axis becomes larger. However, by adjusting the color using a color adjustment layer, the change in color when viewed from oblique directions relative to the change in color along the transmittance center axis can be suppressed. This color adjustment layer may have only the function of a color adjustment layer on its own, or it may have functions integrated with other layers.

[0114] The absorption peak wavelength of the dye compound contained in the color adjustment layer used in the present invention is preferably 500 nm to 650 nm, and more preferably 550 nm to 600 nm. By setting the absorption of the dye compound within this range, the color of the optical film in the present invention can be adjusted to be more neutral.

[0115] Examples of dye compounds included in the color adjustment layer include azo, methine, anthraquinone, triarylmethane, oxazine, azomethine, phthalocyanine, porphyrin, perylene, pyrrolopyrrole, and squarylium. However, azo, phthalocyanine, and anthraquinone are preferred from the viewpoint of excellent absorption waveform, heat resistance, and light resistance, with anthraquinone being particularly preferred. Examples include the dye compounds described in "Functional Dyes" by Shin Okawara, Ken Matsuoka, Tsuneaki Hirashima, and Teijiro Kitao, Kodansha, 1992, and "Electronics-Related Materials" supervised by Sumio Tokita, CMC Co., Ltd., 1998.

[0116] The following are specific examples of dye compounds used in the present invention, but the present invention is not limited to these.

[0117] Anthraquinon [ka]

[0118] Azo [ka]

[0119] Triarylmethane [ka]

[0120] Oxazine [ka]

[0121] Phthalocyanine [ka]

[0122] [Polarizer] The polarizer used in this invention is not particularly limited as long as it is a material that has an absorption axis in its plane and has the function of converting light into a specific linear polarization; conventionally known polarizers can be used. Examples of polarizers include iodine-based polarizers, dye-based polarizers using dichroic dyes, and polyene-based polarizers. Iodine-based polarizers and dye-based polarizers include coated polarizers and stretched polarizers, both of which can be applied. As polarizers, polarizers in which dichroic organic dyes are oriented using the orientation of liquid crystalline compounds are preferred, and as stretched polarizers, polarizers made by adsorbing iodine or a dichroic dye onto polyvinyl alcohol and stretching it are preferred. Examples include a light-absorbing anisotropic layer containing a dichroic dye compound that is horizontally oriented (in a direction intersecting the thickness direction of the optically anisotropic film) and does not contain the liquid crystalline compound described in Japanese Patent Publication No. 2010-152351, and a light-absorbing anisotropic layer containing a liquid crystalline compound and a horizontally oriented dichroic dye compound described in International Publication No. 2017 / 154907. Furthermore, as a method for obtaining a polarizer by stretching and dyeing a laminated film in which a polyvinyl alcohol layer is formed on a substrate, examples include those described in Japanese Patent Publication No. 5048120, Japanese Patent Publication No. 5143918, Japanese Patent Publication No. 5048120, Japanese Patent Publication No. 4691205, Japanese Patent Publication No. 4751481, and Japanese Patent Publication No. 4751486, and these known technologies related to polarizers can also be preferably utilized. Here, horizontal orientation refers to the fact that the molecular axis of the liquid crystalline compound or dichroic dye compound (for example, the long axis in the case of a rod-shaped liquid crystalline compound) is parallel to the principal plane of the polarizer. However, it does not require strict parallelism; rather, it means that the inclination angle between the average molecular axis of the liquid crystalline compound or dichroic dye compound in the polarizer and the principal plane of the polarizer is less than ±10 degrees. This inclination angle can be measured using AxoScan OPMF-1 (OptoScience Co., Ltd.). Specifically, using an AxoScan OPMF-1 (OptoScience Co., Ltd.), the Mueller matrix of a polarizer at wavelength λ is measured at room temperature at 10-degree intervals from -50° to 50° pole angles. After removing the effects of surface reflection, the extinction coefficients ko[λ] (in-plane direction) and ke[λ] (thickness direction) are calculated by fitting the data to the following theoretical formulas that consider Snell's and Fresnel's equations. Unless otherwise specified, the wavelength λ is assumed to be 550 nm. k = -log(T) × λ / (4πd) Here, T represents the transmittance and d represents the thickness of the polarizer. By calculating the absorbance in the in-plane direction and thickness direction, as well as the dichromatic ratio, from the calculated ko[λ] and ke[λ], it is possible to confirm whether or not the material is horizontally oriented.

[0123] [Application] The optical film of the present invention is not limited to this, but is preferably used for preventing unauthorized viewing of a display device and for controlling the viewing angle range.

[0124] [Display device] The present invention provides a display device (image display device) comprising an optical film having the polarizer described above, and a display element. The display element is preferably positioned on the polarizer side of the optical film (i.e., the side opposite to the transparent film substrate). The polarizer and the liquid crystal cell may be laminated via a known adhesive or bonding layer. The display elements used in the display device of the present invention are not particularly limited, and examples include liquid crystal cells, organic electroluminescent (hereinafter abbreviated as "EL") display panels, and plasma display panels. Of these, liquid crystal cells or organic EL display panels are preferred. In other words, the display device of the present invention is preferably a liquid crystal display device using liquid crystal cells as the display element, or an organic EL display device using an organic EL display panel as the display element. Some image display devices are thin and can be molded to curved surfaces. The optical anisotropic absorption film used in this invention is thin and easily bendable, making it suitable for use in image display devices with curved display surfaces. Furthermore, some image display devices have a pixel density exceeding 250 ppi, enabling high-definition display. The optical anisotropic absorption film used in this invention can be suitably applied to such high-definition image display devices without causing moiré patterns.

[0125] [Liquid crystal display device] A preferred example of a liquid crystal display device of the present invention is one having an optical film having the polarizer described above and a liquid crystal cell. Specific configurations include placing the optical film of the present invention on either the front or rear polarizing plate. In these configurations, it becomes possible to control the viewing angle by blocking light in the vertical or horizontal direction. Alternatively, the optical film of the present invention may be placed on both the front and rear polarizing plates. This configuration allows for omnidirectional light shielding and field of view control where light is transmitted only in the forward direction. Furthermore, multiple optical films of the present invention may be laminated with a phase difference layer in between. By controlling the phase difference value and the optical axis direction, the transmission performance and light-shielding performance can be controlled. For example, by arranging a polarizer, optical film, λ / 2 wave plate (with an axis angle shifted by 45° from the orientation direction of the polarizer), and optical film, it becomes possible to control the viewing angle so that light is shielded in all directions and transmitted only in the front direction. As the phase difference layer, a positive A plate, a negative A plate, a positive C plate, a negative C plate, a B plate, an O plate, etc., can be used. The thickness of the phase difference layer is preferably as thin as possible from the viewpoint of thinning the viewing angle control system, as long as it does not impair the optical properties, mechanical properties, and manufacturability. Specifically, 1 to 150 μm is preferred, 1 to 70 μm is more preferred, and 1 to 30 μm is even more preferred. The following provides a detailed description of the liquid crystal cells that make up a liquid crystal display device.

[0126] <Liquid crystal cell> The liquid crystal cells used in liquid crystal display devices are preferably in VA (Vertical Alignment) mode, OCB (Optically Compensated Bend) mode, IPS (In-Plane-Switching) mode, or TN (Twisted Nematic) mode, but are not limited to these. In TN mode liquid crystal cells, when no voltage is applied, the rod-shaped liquid crystal molecules are substantially horizontally oriented and further twisted to a 60-120° angle. TN mode liquid crystal cells are the most widely used in color TFT liquid crystal display devices and are described in numerous publications. In VA mode liquid crystal cells, rod-shaped liquid crystalline molecules are substantially oriented vertically when no voltage is applied. VA mode liquid crystal cells include (1) narrowly defined VA mode liquid crystal cells in which rod-shaped liquid crystalline molecules are substantially oriented vertically when no voltage is applied and substantially oriented horizontally when voltage is applied (described in Japanese Patent Publication No. 2-176625), (2) multi-domain liquid crystal cells (MVA mode) in which the VA mode is multi-domain to expand the viewing angle (described in SID97, Digest of tech.Papers (Proceedings) 28 (1997) 845), (3) liquid crystal cells in a mode (n-ASM mode) in which rod-shaped liquid crystalline molecules are substantially oriented vertically when no voltage is applied and twisted multi-domain orientation when voltage is applied (described in the Proceedings of the Japan Liquid Crystal Symposium 58-59 (1998)), and (4) SURVIVAL mode liquid crystal cells (presented at LCD International 98). Furthermore, it may be any of the following types: PVA (Patterned Vertical Alignment), Optical Alignment, or PSA (Polymer-Sustained Alignment). Details of these modes are described in detail in Japanese Patent Publication No. 2006-215326 and Japanese Patent Publication No. 2008-538819.

[0127] In IPS mode liquid crystal cells, the liquid crystalline compound is oriented substantially parallel to the substrate, and when an electric field parallel to the substrate surface is applied, the liquid crystal molecules respond in a planar manner. That is, in the absence of an applied electric field, the liquid crystalline compound is oriented in-plane. In IPS mode, black is displayed in the absence of an applied electric field, and the absorption axes of the pair of upper and lower polarizers are orthogonal. Methods for reducing light leakage during black display in oblique directions and improving the viewing angle using an optical compensation sheet are disclosed in Japanese Patent Publication No. 10-54982, Japanese Patent Publication No. 11-202323, Japanese Patent Publication No. 9-292522, Japanese Patent Publication No. 11-133408, Japanese Patent Publication No. 11-305217, and Japanese Patent Publication No. 10-307291, among others.

[0128] [Organic EL display device] As an example of the display device of the present invention, an organic EL display device is preferably configured to have, in this order from the viewing side, an optical film having the polarizer described above, a λ / 4 plate, and an organic EL display panel. Furthermore, similar to the liquid crystal display device described above, multiple optical films of the present invention may be stacked with a phase difference layer in between and arranged on an organic EL display panel. By controlling the phase difference value and the optical axis direction, the transmission performance and light-shielding performance can be controlled. Furthermore, an organic EL display panel is a display panel constructed using an organic EL element in which an organic light-emitting layer (organic electroluminescent layer) is sandwiched between electrodes (between the cathode and the anode). The configuration of the organic EL display panel is not particularly limited, and known configurations can be adopted. [Examples]

[0129] The present invention will be described in more detail below based on the following examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the following examples.

[0130] [Example 1] Optical film A of Example 1 was manufactured as follows.

[0131] [Formation of orientation film 1] The following alignment film-forming composition 1 was continuously applied to a cellulose acylate film (TAC substrate with a thickness of 40 μm; TG40, Fujifilm Corporation) using a wire bar. The coated support was dried with 140°C hot air for 120 seconds to form an alignment film 1, obtaining an alignment film-coated TAC film 1. The thickness of the alignment film 1 was 0.5 μm.

[0132] ------------------------------------------------------------------ (Composition for forming alignment film 1) ------------------------------------------------------------------ • 100.00 parts by mass of the polymer PA1 listed below • Acid generator PAG-1: 8.25 parts by mass • Stabilizer DIPEA 0.6 parts by mass Methyl ethyl ketone 250.36 parts Butyl acetate 1001.42 parts by mass ------------------------------------------------------------------

[0133] [ka]

[0134] [Fabrication of optically anisotropic film 1] The following liquid crystal composition 1 was continuously applied onto the obtained alignment film 1 using a wire bar, heated at 120°C for 60 seconds, and then cooled to room temperature (23°C). Next, it was heated at 85°C for 60 seconds and then cooled again to room temperature. Subsequently, an illuminance of 200 mW / cm was achieved using an LED (light-emitting diode) lamp (center wavelength 365 nm). 2 An optically anisotropic film 1 was fabricated on the alignment film 1 by irradiating it for 2 seconds under the specified irradiation conditions. The thickness of the optically anisotropic film 1 was 3.5 μm. ------------------------------------------------------------------ Composition of liquid crystal composition 1 ------------------------------------------------------------------ • 6.069 parts by mass of the following polymeric liquid crystalline compound L1 ·Low molecular weight liquid crystal compound L2 3.843 parts by mass • The following dichroic substance Y1: 0.659 parts by mass • The following dichroic substance M1: 0.162 parts by mass • The following dichroic substance C1: 1.629 parts by mass • 0.004 parts by mass of the following interface modifier B1 • 0.224 parts by mass of the following orientation agent B2 • Orientation agent B3: 0.224 parts by mass • Polymerization initiator (IRGACUREOXE-02, manufactured by BASF) 0.187 parts by mass Cyclopentanone 78,300 parts by mass • Benzyl alcohol 8,700 parts by mass ------------------------------------------------------------------

[0135] [ka]

[0136] [ka]

[0137] [ka]

[0138] [Formation of barrier layer B1] The following color adjustment layer-forming composition B1 was continuously applied to the obtained optical anisotropic film 1 using a wire bar to form a coating film. Next, the support on which the coating film was formed was dried with 60°C hot air for 60 seconds, and then with 100°C hot air for 120 seconds to form a color adjustment layer G1, which was then used to form optical film 1. The thickness of the barrier layer was 0.5 μm. ------------------------------------------------------------------ (Composition B1 for forming a color adjustment layer) ------------------------------------------------------------------ • 3.80 parts by mass of the following modified polyvinyl alcohol PVA-1 ·IRGACURE2959 0.20 parts by mass ·Water 70 parts by mass • Methanol 30 parts by mass ------------------------------------------------------------------

[0139] Modified polyvinyl alcohol PVA-1 [ka]

[0140] [Comparative Example 1] An optical film H1 was prepared by forming an optical anisotropic film and a barrier layer on the cellulose acylate film described above in the same manner as in Example 1, except that the following liquid crystal composition H1 was used for the optical anisotropic film. ------------------------------------------------------------------ Composition of liquid crystal composition H1 ------------------------------------------------------------------ • 8.185 parts by mass of the above polymeric liquid crystalline compound L1 ·Low molecular weight liquid crystal compound L2 4.079 parts by mass • The following dichroic substance Y2: 0.189 parts by mass ·0.100 parts by mass of the following dichroic substance M2 • The following dichroic substance C2: 0.127 parts by mass • 0.004 parts by mass of the above-mentioned interface modifier B1 • 0.158 parts by mass of the above-mentioned orientation agent B2 • 0.158 parts by mass of the above-mentioned orientation agent B3 • Polymerization initiator (IRGACUREOXE-02, manufactured by BASF) 0.198 parts by mass Cyclopentanone 58.120 parts by mass Tetrahydrofuran 28.680 parts by mass ------------------------------------------------------------------

[0141] [Example 2] An optical film 2 was prepared by forming an optical anisotropic film and a barrier layer on the cellulose acylate film described above, in the same manner as in Example 1, except that the following liquid crystal composition 2 was used for the optical anisotropic film. ------------------------------------------------------------------ Composition of liquid crystal composition 2 ――――――――――――――――――――――――――――――――― · 4.011 parts by mass of the following polymer liquid crystalline compound L3 · 0.792 parts by mass of the following dichroic substance Y3 · 0.963 parts by mass of the following dichroic substance C3 Y4· 0.087 parts by mass of the above interfacial improver B1 · 0.073 parts by mass of the above alignment agent B2 · 0.073 parts by mass of the above alignment agent B3 · 82.460 parts by mass of cyclopentanone · 4.340 parts by mass of benzyl alcohol ―――――――――――――――――――――――――――――――――

[0142]

Chemical formula

[0143]

Chemical formula

[0144] [Comparative Example 2] An optical anisotropic film and a barrier layer were formed in the same manner as in Example 1 except that the following liquid crystal composition H2 was used for the optical anisotropic film on the above cellulose acylate film, and an optical film H2 was produced. ――――――――――――――――――――――――――――――――― Composition of liquid crystal composition H2 ――――――――――――――――――――――――――――――――― · 5.340 parts by mass of the above polymer liquid crystalline compound L3 · 0.160 parts by mass of the above dichroic substance Y3 · 0.184 parts by mass of the following dichroic substance M3 · 0.340 parts by mass of the following dichroic substance C4 · 0.004 parts by mass of the above interfacial improver B1 · 0.165 parts by mass of the above alignment agent B2 • 0.165 parts by mass of the above-mentioned orientation agent B3 • Polymerization initiator (IRGACUREOXE-02, manufactured by BASF) 0.146 parts by mass Cyclopentanone 59.840 parts by mass • Tetrahydrofuran 33.660 parts by mass ------------------------------------------------------------------

[0145] [ka]

[0146] Figure 4 shows a scanning transmission electron microscope image of the optical anisotropy film contained in the optical film of Example 1 in cross-section, and Figure 5 shows the scanning transmission electron microscope image of Figure 4 with the brightness binarized using the method described above (such as setting a threshold). Furthermore, when the length L of the long axis of the array structure was measured for the optical anisotropic films contained in the optical films of Examples 1-2 and Comparative Examples 1-2 using the method described above, the number of array structures satisfying L ≥ 30 nm and L ≥ 240 nm were observed as shown in Table 1 below. Furthermore, for the optically anisotropic films contained in Examples 1-2 and Comparative Examples 1-2, the angle between the long axis of the arrangement structure and the normal direction of the optically anisotropic film was measured. The results are shown in Table 1 below. Furthermore, when the optical anisotropy films contained in the optical films of Examples 1 and 2 were evaluated according to the vertical orientation evaluation method described above, it was found that in all cases, the crystalline compound and dichroic substance in the optical anisotropy films contained in the optical films were vertically oriented.

[0147] [evaluation] The following evaluations were performed using the optical films of Examples 1-2 and Comparative Examples 1-2.

[0148] [Lightfastness] Using AxoScan OPMF-1 (manufactured by OptoSciences), the front transmittance (Tm0) of each optical film in the examples and comparative examples was measured. Subsequently, a xenon weather meter (Super Xenon Weather Meter SX75; manufactured by Suga Test Instruments Co., Ltd.) was set so that the incident angle of xenon light was 60°, and xenon irradiation was performed at 60° and 50% RH, 150 W / m 2 for 110 hours. The front transmittance (TX0) of the film after light resistance was measured in the same manner, and the light resistance (ΔTxe) was evaluated using the following formula. The results are shown in Table 1 below. ΔTxe = |Tm0 - TX0| A: ΔTxe is 1.0% or less B: ΔTxe is greater than 1.0 and 1.5 or less C: ΔTxe is greater than 1.5 and 3.0 or less D: ΔTxe is greater than 3.0

[0149] <° 〔Durability〕 In the same manner as the light resistance evaluation, the front transmittance (Tm0) of each optical film in the examples and comparative examples was measured. Next, each optical film was set in a heat resistance tester at 95°C and 25% RH (relative humidity), and heated for 110 hours. The front transmittance (TH0) of the film after heating was measured in the same manner, and the light resistance (ΔTH) was evaluated using the following formula. ΔTH = |Tm0 - TH0| A: ΔTxe is 3.0% or less B: ΔTxe is greater than 3.0 and 5.0 or less C: ΔTxe is greater than 5.0 and 10.0 or less D: ΔTxe is greater than 10.0

[0150] 〔Contrast〕 Using each optical film in the examples and comparative examples, the Mueller matrix of the optical film at wavelength λ was measured every 10 degrees from the polar angle -60 degrees to 60 degrees using AxoScan OPMF-1 (manufactured by OptoSciences). After removing the influence of surface reflection, the front transmittance (Tm0) and the transmittance at 30° (Tm30) were calculated, and the contrast (CR) was evaluated using the following formula. CR = Tm0 / Tm30 A: Cr is 2.97 or higher B:Cr is less than 2.97 and greater than or equal to 1.69 C:Cr is less than 1.69 and greater than or equal to 1.27 D:Cr is less than 1.27 and greater than or equal to 1.10 E:Cr is less than 1.10

[0151] [Table 1]

[0152] [Manufacturing of display devices] [Formation of color adjustment layer G1] The following color adjustment layer-forming composition G1 was continuously applied to the optically anisotropic film 1 obtained in Example 1 using a wire bar to form a coating film. Next, the support on which the coating film was formed was dried with 60°C hot air for 60 seconds, and then with 100°C hot air for 120 seconds to form a color adjustment layer G1, which was then used to form optical film 1a. The thickness of the color adjustment layer was 0.5 μm. ------------------------------------------------------------------ (Composition G1 for forming a color adjustment layer) ------------------------------------------------------------------ • 3.80 parts by mass of the above-mentioned modified polyvinyl alcohol PVA-1 ·IRGACURE2959 0.20 parts by mass • 0.08 parts by mass of the following dye compound G-1 ·Water 70 parts by mass • Methanol 30 parts by mass ------------------------------------------------------------------

[0153] [ka]

[0154] [Fabrication of optical laminate A1] A polarizer with a thickness of 8 μm and one side of the polarizer exposed was produced in the same manner as the polarizing plate 02 with a single-sided protective film described in International Publication No. 2015 / 166991. The exposed surface of the polarizer of the polarizing plate 1 and the surface of the color tone adjustment layer of the produced optical film 1a were corona-treated and bonded using the following PVA adhesive 1 to produce an optical laminate A1.

[0155] <Preparation of PVA Adhesive 1> To 100 parts of a polyvinyl alcohol-based resin containing an acetoacetyl group (average degree of polymerization: 1200, saponification degree: 98.5 mol%, acetoacetylation degree: 5 mol%), 20 parts of methylol melamine was dissolved in pure water under temperature conditions of 30 °C to prepare an aqueous solution adjusted to a solid content concentration of 3.7%.

[0156] [Production of Image Display Device A1] An iPad Air Wi-Fi model 16GB (manufactured by APPLE), which is an IPS-mode liquid crystal display device, was disassembled to take out the liquid crystal cell. The viewing-side polarizing plate was peeled off from the liquid crystal cell, and the above-produced laminate A1 was bonded to the surface from which the viewing-side polarizing plate was peeled off using the following adhesive sheet 1 so that the polarizing plate 1 side faced the liquid crystal cell side. At this time, the direction of the absorption axis of the polarizing plate 1 was bonded so as to be the same as that of the absorption axis of the viewing-side polarizing plate attached to the product. After bonding, it was reassembled to produce an image display device A1.

[0157] (Preparation of Adhesive Sheet 1) An acrylate-based polymer was prepared according to the following procedure. In a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer, and a stirring device, 95 parts by weight of butyl acrylate and 5 parts by weight of acrylic acid were polymerized by solution polymerization to obtain an acrylate-based polymer A1 having an average molecular weight of 2 million and a molecular weight distribution (Mw / Mn) of 3.0.

[0158] Next, 100 parts by mass of the obtained acrylate polymer A1 was mixed with 1.0 part by mass of Coronate L (a 75% by mass ethyl acetate solution of trimethylolpropane adduct of tolylene diisocyanate, with 3 isocyanate groups per molecule, manufactured by Nippon Polyurethane Industry Co., Ltd.) and 0.2 parts by mass of silane coupling agent KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.). Finally, ethyl acetate was added to achieve a total solid content concentration of 10% by mass to prepare an adhesive-forming composition. This composition was applied to a separator film surface-treated with a silicone-based release agent using a die coater and dried at 90°C for 1 minute to obtain an acrylate-based adhesive sheet. The film thickness was 25 μm and the storage modulus was 0.1 MPa.

[0159] When the image display device fabricated in Example 1 was used to display white, the color from both the front and oblique angles was neutral. [Explanation of Symbols]

[0160] P optical anisotropic film M (the molecule of the first dichroic substance) O (the second dichroic substance) molecule L (crystalline compound) molecule G aggregate w width a angle

Claims

1. An optically anisotropic film containing a liquid crystalline compound and a dichroic substance, The liquid crystalline compound is vertically oriented, The aforementioned dichroic substance forms an array structure, In a cross-section observed with a scanning transmission electron microscope, when the length of the long axis of the array structure is L and the length of the short axis is D, the array structure satisfying 30 nm ≤ L ≤ 240 nm is 40 μm. ２ More than 16 were observed per unit, An optically anisotropic film in which, among the aforementioned arrangement structures, the proportion of arrangement structures where the angle between the long axis of the arrangement structure and the normal direction of the optically anisotropic film is 20° or more is 28.0% or more.

2. An optical film comprising a transparent film substrate and an optically anisotropic film according to claim 1 disposed on the transparent film substrate.

3. Furthermore, the optical film according to claim 2, further comprising an orientation film between the transparent film substrate and the optically anisotropic film.

4. Furthermore, it has a polarizer with an absorption axis in the plane, An optical film according to claim 2 or 3, used for controlling the field of view.

5. A display device comprising the optical film described in claim 4 and a display element.

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