Optical films, optical laminates and image display devices

Abstract

The objective of this invention is to provide an optical film capable of producing a neutral hue when viewed from the direction of the transmittance central axis and when viewed from a direction tilted from the transmittance central axis, and to provide an optical laminate and an image display device using the optical film. The optical film of this invention comprises: a light-absorbing anisotropic layer with an angle θ of 0 to 45° between the transmittance central axis and the normal direction of the layer surface; and a hue-adjusting layer comprising at least one organic pigment compound.

Description

Technical Field

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

[0002] A technique is known for using an anisotropic light-absorbing layer having an absorption axis in the thickness direction to prevent peeping into a liquid crystal display device or to control the viewing angle. For example, Patent Document 1 proposes a polarizing element related to a viewing angle control system using a thin film containing a dichroic material, wherein the angle between the absorption axis and the normal to the surface of the thin film is 0° to 45°.

[0003] Previous technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2009-145776 Summary of the Invention

[0006] The technical problem to be solved by the invention

[0007] The inventors have studied an optical film having a light absorption anisotropic layer containing a dichroic substance, and the results show that: since the thickness of the optical film can be reduced, its processing applicability is excellent; on the other hand, since the orientation of the dichroic substance in the visible region is not uniform, it is difficult to control the hue of the optical film when viewed from the transmittance central axis of the light absorption anisotropic layer, and the hue when viewed from the direction tilted from the transmittance central axis, to be neutral.

[0008] Therefore, the objective of this invention is to provide an optical film that is neutral in hue when viewed from the transmissivity center axis and in hue when viewed from a direction tilted from the transmissivity center axis, as well as an optical laminate and an image display device using the optical film.

[0009] means for solving technical problems

[0010] As a result of in-depth research in order to solve the above-mentioned problems, the inventors discovered that an optical film comprising a defined light absorption anisotropic layer and a hue adjustment layer having at least one organic pigment compound can make the hue neutral when viewed from the direction of the central axis of transmittance and when viewed from the direction tilted from the central axis of transmittance. Thus, the present invention was completed.

[0011] That is, it was discovered that the above-mentioned problem can be achieved through the following configuration.

[0012] [1] An optical film having: a light absorption anisotropic layer with an angle θ of 0 to 45° between the central axis of transmittance and the normal direction of the layer surface, and a hue adjustment layer containing at least one organic pigment compound.

[0013] [2] According to the optical film described in [1], wherein,

[0014] The aforementioned light-absorbing anisotropic layer comprises a liquid crystal compound and at least one dichroic pigment compound.

[0015] [3] The optical film according to [1] or [2], wherein,

[0016] The aforementioned light-absorbing anisotropic layer satisfies equations (1) and (2) described later.

[0017] [4] The optical film according to [2] or [3], wherein,

[0018] At least one of the dichroic pigment compounds contained in the aforementioned light-absorbing anisotropic layer is represented by formula (3) described later.

[0019] [5] The optical film according to any one of [1] to [4], wherein,

[0020] The aforementioned tone adjustment layer satisfies any one of the requirements 1 to 3 described below.

[0021] [6] The optical film according to any one of [1] to [5], wherein,

[0022] The absorption peak wavelength of the organic pigment compounds contained in the above-mentioned tone adjustment layer is 500-650 nm.

[0023] [7] The optical film according to any one of [1] to [6], wherein,

[0024] The organic pigment compounds contained in the aforementioned hue adjustment layer have at least one structure of benzene ring and heterocycle in their molecules.

[0025] [8] The optical film according to any one of [1] to [7], wherein,

[0026] The organic pigment compounds contained in the aforementioned tone adjustment layer have anthraquinone structures.

[0027] [9] An optical film according to any one of [1] to [8], which satisfies formula (7) described below.

[0028]

[10] The optical film according to any one of [1] to [9], wherein,

[0029] The transmittance of light with a wavelength of 550 nm along the direction of the aforementioned transmittance central axis is 65% or more.

[0030]

[11] An optical laminate comprising: an optical film as described in any one of [1] to

[10] and a polarizer layer of dichroic material oriented horizontally relative to the film surface.

[0031]

[12] An optical laminate having: an optical film as described in any one of [1] to

[10] and an uneven layer having an arithmetic mean roughness Ra of 35 to 125 nm.

[0032]

[13] An image display device having: an optical film as described in any one of [1] to

[10] or an optical laminate as described in

[11] or

[12] .

[0033] Invention Effects

[0034] According to the present invention, an optical film capable of making the hue neutral when viewed from the transmissivity center axis direction and when viewed from a direction tilted from the transmissivity center axis, as well as an optical laminate and an image display device using the optical film, are provided. Detailed Implementation

[0035] The present invention will now be described in detail.

[0036] The description of the constituent elements described below is sometimes made according to representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0037] In this specification, the numerical range indicated by “~” represents the range included by the values ​​recorded before and after “~” as the lower and upper limits.

[0038] In this specification, parallel and orthogonal do not refer to parallel and orthogonal in the strict sense, but rather to the range of parallel ±5° and orthogonal ±5°, respectively.

[0039] Unless otherwise specified, visible light in this specification refers to electromagnetic waves with wavelengths of 380–800 nm.

[0040] Unless otherwise specified, room temperature in this instruction manual refers to 20–28°C.

[0041] In this specification, the concepts of liquid crystal compositions and liquid crystal compounds also include liquid crystal compositions and liquid crystal compounds that no longer exhibit liquid crystal properties due to curing or other processes.

[0042] In this specification, each component may be used alone with one corresponding substance, or with two or more substances used together. Here, regarding each component, when two or more substances are used together, the content of that component, unless otherwise specified, refers to the total content of the substances used together.

[0043] In this specification, "(meth)acrylate" is the designation for "acrylate" or "methacrylate", "(meth)acrylic acid" is the designation for "acrylic acid" or "methacrylic acid", and "(meth)acryloyl" is the designation for "acryloyl" or "methacryloyl".

[0044] The substituent W in this specification will be explained.

[0045] As substituent W, examples include alkyl groups (preferably alkyl groups with 1 to 20 carbon atoms, more preferably alkyl groups with 1 to 12 carbon atoms, and especially preferably alkyl groups with 1 to 8 carbon atoms, such as methyl, ethyl, isopropyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, and cyclohexyl), alkenyl groups (preferably alkenyl groups with 2 to 20 carbon atoms, more preferably alkenyl groups with 2 to 12 carbon atoms, and especially preferably alkenyl groups with 2 to 8 carbon atoms, such as vinyl, aryl, 2-butenyl, and 3-pentenyl), alkynyl groups (preferably alkenyl groups with 2 to 20 carbon atoms, more preferably alkenyl groups with 2 to 12 carbon atoms, and especially preferably alynyl groups with 2 to 8 carbon atoms, such as propynyl and 3-pentynyl), aryl groups (preferably... The aryl group has 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and especially preferably 6 to 12 carbon atoms. Examples include phenyl, 2,6-diethylphenyl, 3,5-ditrifluoromethylphenyl, styryl, naphthyl, and biphenyl, etc.); substituted or unsubstituted amino groups (preferably 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, and especially preferably 0 to 6 carbon atoms, examples include unsubstituted amino, methylamino, dimethylamino, diethylamino, and aniline, etc.); alkoxy groups (preferably 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, examples include methoxy, ethoxy, and butoxy, etc.); and oxycarbonyl groups (preferably 2 to 20 carbon atoms, more preferably carbon...). The number of carbon atoms is 2 to 15, particularly preferably 2 to 10, for example, methoxycarbonyl, ethoxycarbonyl and phenoxycarbonyl, etc.); acyloxy (preferably 2 to 20 carbon atoms, more preferably 2 to 10 carbon atoms, especially preferably 2 to 6, for example, acetoxy, benzoyloxy, acryloyl and methacryloyl, etc.); amide (preferably 2 to 20 carbon atoms, more preferably 2 to 10 carbon atoms, especially preferably 2 to 6 carbon atoms, for example, acetamino and benzoylamino, etc.); alkoxycarbonylamino (preferably 2 to 20 carbon atoms, more preferably 2 to 10 carbon atoms, especially preferably 2 to 6 carbon atoms, for example, methoxycarbonylamino, etc.); aryloxycarbonylamino. (Preferably 7-20 carbon atoms, more preferably 7-16 carbon atoms, especially preferably 7-12 carbon atoms, for example, phenoxycarbonylamino, etc.), sulfonylamino (preferably 1-20 carbon atoms, more preferably 1-10 carbon atoms, especially preferably 1-6 carbon atoms, for example, methanesulfonylamino and benzenesulfonylamino, etc.), aminosulfonyl (preferably 0-20 carbon atoms, more preferably 0-10 carbon atoms, especially preferably 0-6 carbon atoms, for example, aminosulfonyl, methylaminosulfonyl, dimethylaminosulfonyl and phenylaminosulfonyl, etc.), carbamoyl (preferably 1-20 carbon atoms, more preferably 1-10 carbon atoms, especially preferably 1-6 carbon atoms, for example,Examples of suitable carbonyl groups include unsubstituted carbamoyl, methylcarbamoyl, diethylcarbamoyl, and phenylcarbamoyl, etc.; alkylthio (preferably with 1 to 20 carbon atoms, more preferably with 1 to 10 carbon atoms, and especially preferably with 1 to 6 carbon atoms, for example, methylthio and ethylthio, etc.); arylthio (preferably with 6 to 20 carbon atoms, more preferably with 6 to 16 carbon atoms, and especially preferably with 6 to 12 carbon atoms, for example, phenylthio, etc.); sulfonyl (preferably with 1 to 20 carbon atoms, more preferably...). The carbon number is selected as 1 to 10, especially preferably 1 to 6, for example, methanesulfonyl and toluenesulfonyl, etc.); sulfinyl (preferably 1 to 20, more preferably 1 to 10, especially preferably 1 to 6, for example, methanesulfinyl and benzenesulfinyl, etc.); urea (preferably 1 to 20, more preferably 1 to 10, especially preferably 1 to 6, for example, unsubstituted urea, methylurea and phenylurea, etc.). Phosphoramide group (preferably with 1 to 20 carbon atoms, more preferably with 1 to 10 carbon atoms, especially preferably with 1 to 6 carbon atoms, for example, diethylphosphoramide group and phenylphosphoramide group, etc.), hydroxyl group, mercapto group, halogen atom (e.g., fluorine atom, chlorine atom, bromine atom and iodine atom), cyano group, nitro group, hydroxamic acid group, sulfinyl group, hydrazine group, imino group, azo group, heteroatom-containing cyclic group (preferably with 1 to 30 carbon atoms, more preferably with 1 to 12 carbon atoms, for example, a cyclic group having a nitrogen atom). Heteroatom-containing cyclic groups, such as those containing oxygen atoms, sulfur atoms, etc., include, for example, epoxy, oxacyclobutyl, imidazolyl, pyridinyl, quinolinyl, furanyl, piperidinyl, morpholinyl, maleimide, benzoxazolyl, benzimidazolyl, and benzothiazolyl. Silyyl groups (preferably silyl groups with 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, and especially preferably silyl groups with 3 to 24 carbon atoms, for example, trimethylsilyl, triphenylsilyl, etc.), carboxyl groups, sulfonic acid groups, phosphate groups, etc.

[0046] The optical film, optical laminate, and image display device will be described below.

[0047] In addition, the state in which "the hue when viewed from the center axis of transmittance and the hue when viewed from the direction of the tilt of the center axis of transmittance are both neutral" will also be referred to as "excellent hue suppression across a wide range of colors".

[0048] <Optical film>

[0049] The optical film of the present invention comprises: a light absorption anisotropic layer in which the angle θ between the central axis of transmittance and the normal direction of the layer surface is 0 to 45°; and a hue adjustment layer comprising at least one organic pigment compound.

[0050] Here, the mechanism by which the optical film of the present invention can make the hue neutral when viewed from the direction of the central axis of transmittance and when viewed from the direction of the tilt of the central axis of transmittance is not yet clear, but the inventors speculate as follows.

[0051] Hypothesis: The reason why the hue is not neutral when viewed from the above two directions in the anisotropic light absorption layer of the optical film is due to the orientation of the substances contained in the anisotropic light absorption layer. It is believed that the hue can be reduced by using a hue adjustment layer containing at least one organic pigment compound, thus making the hue neutral when viewed from the above two directions.

[0052] In addition to the light absorption anisotropic layer and the color adjustment layer, the optical film of the present invention may also have a transparent substrate film, an alignment film, a barrier layer, an adhesive layer and a bonding layer.

[0053] The following is a detailed description of the light absorption anisotropic layer, the tone adjustment layer, the transparent substrate film, the alignment film, and the barrier layer.

[0054] Furthermore, the manufacturing method of the optical film will be described in detail below. The adhesive layer and bonding layer will be explained in the manufacturing method of the optical film.

[0055] [Light Absorption Anisotropic Layer]

[0056] In the optical film of the present invention, the angle between the transmittance central axis and the normal direction of the layer surface in the light absorption anisotropic layer is 0° to 45°.

[0057] Here, the transmittance center axis refers to the direction representing the highest transmittance when measuring transmittance by changing the tilt angle (polar angle) and tilt direction (azimuth angle) relative to the normal direction of the light-absorbing anisotropic layer surface. Specifically, the Mueller matrix at a wavelength of 550 nm is measured using an AxoScan OPMF-1 (manufactured by Opto Science, Inc.). More specifically, during the measurement, the azimuth angle of the transmittance center axis tilt is first searched. Then, within a plane including the normal direction of the light-absorbing anisotropic layer along that azimuth angle (including the transmittance center axis, a plane orthogonal to the layer surface), the angle (polar angle) of the light-absorbing anisotropic layer surface relative to the normal direction is changed in 5° increments within the range of 0–90°, while simultaneously measuring the Mueller matrix at a wavelength of 550 nm, thus deriving the transmittance of the light-absorbing anisotropic layer. As a result, the direction with the highest transmittance is designated as the transmittance center axis.

[0058] By adjusting the angle between the central axis of the light-absorbing anisotropic layer and the normal direction of the layer surface, the viewing angle center of the liquid crystal display device can be moved not only from the front, up, down, left, and right, but also in the tilt direction.

[0059] To control the central axis of the transmission axis of the light-absorbing anisotropic layer, it is preferable to orient the dichroic material, and even more preferable to orient the dichroic material by orienting it using a liquid crystal compound. Therefore, the light-absorbing anisotropic layer preferably comprises a liquid crystal compound and a dichroic material.

[0060] As an example, one could cite an anisotropic layer that causes at least one organic dichroic pigment to absorb light relative to its in-plane vertical orientation.

[0061] The light-absorbing anisotropic layer is preferably manufactured using the light-absorbing anisotropic layer forming composition described later. The light-absorbing anisotropic layer forming composition preferably contains a liquid crystal compound and a dichroic substance.

[0062] The composition for forming anisotropic light-absorbing layers and the method for forming the composition for forming anisotropic light-absorbing layers will be described in detail later.

[0063] (Liquid crystal compounds)

[0064] The optical film of the present invention preferably contains a liquid crystal compound in its light-absorbing anisotropic layer. When the light-absorbing anisotropic layer is formed, by containing a liquid crystal compound, it is possible to suppress the precipitation of dichroic substances while improving the orientation degree of the dichroic substances in the light-absorbing anisotropic layer.

[0065] Liquid crystal compounds are liquid crystal compounds that do not exhibit dichroism at least with respect to visible light.

[0066] As a liquid crystal compound, either a low-molecular-weight liquid crystal compound or a high-molecular-weight liquid crystal compound can be used, and preferably both. Here, "low-molecular-weight liquid crystal compound" refers to a liquid crystal compound that does not have repeating units in its chemical structure. Here, "high-molecular-weight liquid crystal compound" refers to a liquid crystal compound that has repeating units in its chemical structure.

[0067] -Low molecular weight liquid crystal compounds-

[0068] As a low-molecular-weight liquid crystal compound, for example, the liquid crystal compound described in Japanese Patent Application Publication No. 2013-228706 can be cited.

[0069] -Polymer liquid crystal compounds-

[0070] As a polymeric liquid crystal compound, for example, the thermotropic liquid crystal polymer described in Japanese Patent Application Publication No. 2011-237513 can be cited. Furthermore, from the viewpoint of excellent strength (especially bending resistance) of the light absorption anisotropic film, the polymeric liquid crystal compound preferably has repeating units with crosslinking groups at the ends. As a crosslinking group, for example, the polymerizable groups described in paragraphs

[0040] to

[0050] of Japanese Patent Application Publication No. 2010-244038 can be cited. Among these, from the viewpoint of improved reactivity and synthetic applicability, acryloyl, methacryl, epoxy, oxetyl, and styrene groups are preferred, and acryloyl and methacryl are more preferred.

[0071] In the case where the light-absorbing anisotropic layer of the present invention comprises a polymeric liquid crystal compound, the polymeric liquid crystal compound preferably forms a nematic liquid crystal phase.

[0072] The preferred temperature range for displaying the nematic liquid crystal phase is above room temperature and below 450°C, and from the viewpoint of operability and / or manufacturing suitability, it is preferably 50 to 400°C.

[0073] Relative to 100 parts by mass of the dichroic substance, the content of the liquid crystal compound is preferably 25 to 2000 parts by mass, more preferably 100 to 1300 parts by mass, and even more preferably 200 to 900 parts by mass. By keeping the content of the liquid crystal compound within the above range, the orientation degree of the dichroic substance in the light-absorbing anisotropic layer is further improved.

[0074] The liquid crystal compound may contain one or more liquid crystal compounds. When there are two or more liquid crystal compounds, the content of the liquid crystal compound mentioned above refers to the total content of the liquid crystal compounds.

[0075] From the viewpoint that the orientation degree of the dichroic material in the light-absorbing anisotropic layer is superior, the liquid crystal compound is preferably a polymeric liquid crystal compound containing a repeating unit (hereinafter also referred to as "repeating unit (1L)") represented by the following formula (1L).

[0076] [Chemical Formula 1]

[0077]

[0078] In the above formula (1L), P1 represents the main chain of the repeating unit, L1 represents a single bond or a divalent linking group, SP1 represents a spacer group, M1 represents a mesocrystalline group, and T1 represents a terminal group.

[0079] As the main chain of the repeating unit represented by P1, specifically, for example, the groups represented by the following formulas (P1-A) to (P1-D) can be cited, of which, from the viewpoint of the diversity of monomers as raw materials and ease of processing, the group represented by the following formula (P1-A) is preferred.

[0080] [Chemical Formula 2]

[0081]

[0082] In equations (P1-A) to (P1-D), "*" indicates the bonding position with L1 in equation (1L). In equations (P1-A) to (P1-D), R... 1 R 2 R 3 and R 4 Each of the above-mentioned alkyl groups independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. The alkyl group can be a straight-chain or branched alkyl group, or an alkyl group having a cyclic structure (cycloalkyl). Furthermore, the number of carbon atoms in the alkyl group is preferably 1 to 5.

[0083] The group represented by formula (P1-A) is preferably a unit of a partial structure of poly(meth)acrylate obtained by polymerization of (meth)acrylate.

[0084] The group represented by 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.

[0085] The group represented by formula (P1-C) is preferably a propylene glycol unit formed by ring-opening polymerization of an oxetane compound having an oxetane.

[0086] The group represented by formula (P1-D) is preferably a siloxane unit of a polysiloxane obtained by polycondensation of a compound having at least one of alkoxysilyl and silanol groups. Here, as a compound having at least one of alkoxysilyl and silanol groups, an example can be a compound having the formula SiR. 4 (OR 5 Compounds containing the group represented by )2-. Where R 4 The meaning of R in (P1-D) 4 The meanings are the same, multiple R 5 Alkyl groups, which can be independently represented by 1 to 10 hydrogen or carbon atoms respectively.

[0087] L1 represents a single bond or a divalent linker group.

[0088] Examples of 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 - etc. In the formula, R 3 and R 4 Each can independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms and a substituent W.

[0089] When P1 is a group represented by formula (P1-A), from the viewpoint that the orientation degree of the dichroic material in the anisotropic light absorption layer is better, L1 is preferably a group represented by -C(O)O-.

[0090] When P1 is a group represented by formulas (P1-B) to (P1-D), from the viewpoint that the orientation degree of the dichroic material in the anisotropic layer of light absorption is more superior, L1 is preferably a single bond.

[0091] From the viewpoint of easy liquid crystal properties and / or availability of raw materials, the spacer group represented by SP1 preferably includes at least one structure selected from the group consisting of ethylene oxide structure, propylene oxide structure, polysiloxane structure and fluorinated alkylene structure.

[0092] Here, when SP1 represents the ethylene oxide structure, it is preferably *-(CH2-CH2O). n1 -* represents the group. In the formula, n1 represents an integer from 1 to 20, and * represents the bonding position with L1 or M1 in the above formula (1L). From the viewpoint that the orientation degree of the dichroic material in the light-absorbing anisotropic layer is more superior, n1 is preferably an integer from 2 to 10, more preferably an integer from 2 to 4, and most preferably 3.

[0093] Furthermore, when SP1 represents the propylene oxide structure, from the viewpoint that the orientation degree of the dichroic material in the anisotropic light absorption layer is superior, *-(CH(CH3)-CH2O) is preferred. n2 -* represents the group. In the formula, n2 represents an integer from 1 to 3, and * represents the bonding position with L1 or M1.

[0094] Furthermore, when SP1 represents polysiloxane, from the viewpoint that the orientation degree of the dichroic material in the light absorption anisotropic layer is superior, *-(Si(CH3)2-O) is preferred. n3 -* represents the group. In the formula, n3 represents an integer from 6 to 10, and * represents the bonding position with L1 or M1.

[0095] Furthermore, from the viewpoint that the orientation degree of the dichroic material in the anisotropic light absorption layer is superior, the fluorinated alkylene structure represented by SP1 is preferably *-(CF2-CF2). n4 -* represents the group. In the formula, n4 represents an integer from 6 to 10, and * represents the bonding position with L1 or M1.

[0096] The mesocrystalline group represented by M1 is a group that represents the main framework of liquid crystal molecules that contribute to the formation of liquid crystals. Liquid crystal molecules exhibit liquid crystal properties in an intermediate state (intermediate phase) between the crystalline state and the isotropic liquid state. There are no particular limitations regarding the mesocrystalline group; for example, one can refer to the description on pages 7-16 of "Flussige Kristalle in Tabellen II" (VEB Deutsche Verlag fur Grundstoff Industrie, Leipzig, 1984) and the description in Chapter 3 of "Liquid Crystal Handbook" edited by the Liquid Crystal Handbook Editorial Committee (Maruzen, 2000).

[0097] As a mesocrystalline group, it is preferably a group having at least one cyclic structure selected from the group consisting of aromatic hydrocarbon groups, heterocyclic groups and alicyclic groups.

[0098] From the viewpoint that the orientation degree of the dichroic material in the anisotropic light absorption layer is more superior, the mesocrystalline group preferably has an aromatic hydrocarbon group, more preferably has 2 to 4 aromatic hydrocarbon groups, and even more preferably has 3 aromatic hydrocarbon groups.

[0099] From the perspectives of liquid crystal properties, liquid crystal phase transition temperature adjustment, raw material availability and synthetic applicability, and superior orientation of dichroic substances in the light-absorbing anisotropic layer, the group represented by the following formula (M1-A) or the following formula (M1-B) is preferred as a mesocrystalline group, and more preferably the group represented by formula (M1-B).

[0100] [Chemical Formula 3]

[0101]

[0102] In formula (M1-A), A1 is a divalent group selected from the group consisting of aromatic hydrocarbon groups, heterocyclic groups, and alicyclic groups. These groups may be substituted with alkyl, fluorinated alkyl, alkoxy, or substituents W.

[0103] The divalent group represented by A1 is preferably a 4- to 6-membered ring. Furthermore, the divalent group represented by A1 can be a monocyclic ring or a fused ring.

[0104] * indicates the bonding position with SP1 or T1.

[0105] As the divalent aromatic hydrocarbon group represented by A1, examples include phenylene, naphthylene, fluorene-diyl, anthracene-diyl, and tetraphenyl-diyl. From the viewpoint of the diversity of mesocrystalline framework design and / or the availability of raw materials, phenylene or naphthylene is preferred, and phenylene is more preferred.

[0106] The divalent heterocyclic group represented by A1 can be either aromatic or non-aromatic, but from the viewpoint of further improving the orientation degree of the dichroic material in the light absorption anisotropic layer, a divalent aromatic heterocyclic group is preferred.

[0107] Examples of atoms other than carbon that constitute a divalent aromatic heterocyclic group include nitrogen, sulfur, and oxygen atoms. When an aromatic heterocyclic group has multiple atoms that form the ring besides carbon, these atoms may be the same or different.

[0108] Specific examples of divalent aromatic heterocyclic groups include, for example, pyridinyl (pyridin-diyl), pyridazin-diyl, imidazole-diyl, thiophenyl (thiophen-diyl), quinolineyl (quinoline-diyl), isoquinolineyl (isoquinoline-diyl), oxazole-diyl, thiazole-diyl, oxadiazole-diyl, benzothiazole-diyl, benzothiadiazole-diyl, phthalimide-diyl, thienothiazole-diyl, thiazonothiazole-diyl, thienothiphene-diyl, and thienooxazole-diyl.

[0109] Specific examples of the divalent alicyclic group represented by A1 include cyclopentylene and cyclohexylene.

[0110] In formula (M1-A), a1 represents an integer from 1 to 10. When a1 is 2 or higher, multiple A1 values ​​can be the same or different.

[0111] In formula (M1-B), A2 and A3 are each independently a divalent group selected from the group consisting of aromatic hydrocarbon groups, heterocyclic groups, and alicyclic groups. Specific examples and preferred embodiments of A2 and A3 are the same as A1 in formula (M1-A), therefore their description is omitted.

[0112] In formula (M1-B), a2 represents an integer from 1 to 10. When a2 is 2 or more, multiple A2s can be the same or different, multiple A3s can be the same or different, and multiple LA1s can be the same or different. From the viewpoint that the orientation degree of dichroic material in the anisotropic light absorption layer is superior, a2 is preferably an integer of 2 or more, and more preferably 2.

[0113] 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 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, from the viewpoint of having a better orientation degree of the dichroic material in the anisotropic light absorption layer, it is preferable that one of the two LA1s is a divalent linking group and the other is a single bond.

[0114] In formula (M1-B), examples of divalent linking groups represented by LA1 include -O- and -(CH2). g -、-(CF2) g -、-Si(CH3)2-、-(Si(CH3)2O) g -、-(OSi(CH3)2) g -(g represents an integer from 1 to 10.), -N(Z)-, -C(Z)=C(Z')-, -C(Z)=N-, -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)-C(Z)=C(Z′)-, -C(Z)=C (Z')-C(O)-S-, -SC(O)-C(Z)=C(Z')-, -C(Z)=NN=C(Z')- (Z, Z', Z” independently represent hydrogen atoms, alkyl, cycloalkyl, aryl, cyano, or halogen atoms with 1 to 4 carbon atoms, etc.), -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-, etc. Among these, -C(O)O- is preferred from the viewpoint that the orientation degree of the dichroic material in the anisotropic layer of light absorption is superior. LA1 can also be a group composed of two or more of these groups.

[0115] Specific examples of M1 include the following structures. Additionally, in the following examples, "Ac" represents an acetyl group.

[0116] [Chemical Formula 4]

[0117]

[0118] [Chemical Formula 5]

[0119]

[0120] Examples of terminal groups represented by T1 include hydrogen atoms, halogen atoms, cyano groups, nitro groups, hydroxyl groups, alkyl groups with 1 to 10 carbon atoms, alkoxy groups with 1 to 10 carbon atoms, alkylthio groups with 1 to 10 carbon atoms, alkoxycarbonyloxy groups with 1 to 10 carbon atoms, alkoxycarbonyl groups with 1 to 10 carbon atoms (ROC(O)-: R is alkyl), acyloxy groups with 1 to 10 carbon atoms, acylamino groups with 1 to 10 carbon atoms, alkoxycarbonylamino groups with 1 to 10 carbon atoms, sulfonylamino groups with 1 to 10 carbon atoms, aminosulfonyl groups with 1 to 10 carbon atoms, carbamoyl groups with 1 to 10 carbon atoms, sulfinyl groups with 1 to 10 carbon atoms, urea groups with 1 to 10 carbon atoms, and groups containing (meth)acryloyloxy groups. As an example of the group containing (meth)acryloyloxy, one can cite the group represented by -LA (L represents a single bond or a linking group. Specific examples of linking groups are the same as L1 and SP1 above. A represents (meth)acryloyloxy).

[0121] From the viewpoint of superior orientation of the dichroic material in the anisotropic light absorption layer, T1 is preferably an alkoxy group with 1 to 10 carbon atoms, more preferably an alkoxy group with 1 to 5 carbon atoms, and even more preferably a methoxy group. These terminal groups can be further replaced by these groups or the aforementioned crosslinking groups.

[0122] From the viewpoint of achieving superior orientation of the dichroic material in the anisotropic layer for light absorption, 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. By having the number of atoms in the main chain of T1 be 20 or less, the orientation of the dichroic material in the anisotropic layer for light absorption is further improved. Here, "main chain" in T1 refers to the longest molecular chain bonded to M1, and hydrogen atoms are not included in the number of atoms in the main chain of T1. For example, when T1 is n-butyl, the number of atoms in the main chain is 4; when T1 is sec-butyl, the number of atoms in the main chain is 3.

[0123] From the viewpoint that the orientation degree of the dichroic material in the light-absorbing anisotropic layer is better, the content of repeating unit (1L) is preferably 20 to 100% by mass relative to the total repeating unit 100% by mass of the polymeric liquid crystal compound.

[0124] In this invention, the content of each repeating unit contained in the polymeric liquid crystal compound is calculated based on the loading amount (mass) of each monomer used to obtain each repeating unit.

[0125] The polymeric liquid crystal compound may contain only one repeating unit (1L) or two or more. From the viewpoint that the orientation degree of the dichroic material in the light absorption anisotropic layer is superior, it is preferable to include two repeating units (1L) in the polymeric liquid crystal compound.

[0126] In the case of a polymeric liquid crystal compound containing two repeating units (1L), from the viewpoint that the orientation degree of the dichroic material in the light absorption anisotropic layer is better, in one of them (repeating unit A), the terminal group represented by T1 is an alkoxy group, and in the other (repeating unit B), the terminal group represented by T1 is a group other than an alkoxy group.

[0127] From the viewpoint that the orientation degree of the dichroic material in the anisotropic light absorption layer is superior, in the above repeating unit B, the terminal group represented by T1 is preferably alkoxycarbonyl, cyano or a group containing (meth)acryloyloxy, more preferably alkoxycarbonyl or cyano.

[0128] From the viewpoint that the orientation degree of the dichroic material in the light-absorbing anisotropic layer is superior, the ratio (A / B) of the content of the repeating unit A in the polymeric liquid crystal compound to the content of the repeating unit B in the polymeric liquid crystal compound is preferably 50 / 50 to 95 / 5, more preferably 60 / 40 to 93 / 7, and even more preferably 70 / 30 to 90 / 10.

[0129] Furthermore, the polymeric liquid crystal compound can have repeating units (1L) as well as repeating units that do not contain mesocrystalline groups. As a repeating unit that does not contain mesocrystalline groups, M1 in formula (1L) is a repeating unit with a single bond.

[0130] In the case where the polymeric liquid crystal compound has repeating units that do not contain mesocrystalline groups, from the viewpoint that the orientation degree of the dichroic material in the light-absorbing anisotropic layer is better, the percentage of repeating units is preferably more than 0% and less than 30% by mass relative to 100% by mass of the total repeating units of the polymeric liquid crystal compound, more preferably more than 10% and less than 20% by mass.

[0131] -weight-average molecular weight-

[0132] From the viewpoint that the orientation degree of the dichroic material in the anisotropic light absorption layer is superior, the weight-average molecular weight (Mw) of the polymeric liquid crystal compound is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. If the Mw of the polymeric liquid crystal compound is within the above range, the processing of the polymeric liquid crystal compound becomes easier.

[0133] In particular, from the viewpoint of suppressing cracks during coating, the weight-average molecular weight (Mw) of the polymeric liquid crystal compound is preferably 10,000 or more, and more preferably 10,000 to 300,000.

[0134] Furthermore, from the viewpoint of temperature tolerance of orientation, the weight-average molecular weight (Mw) of the polymeric liquid crystal compound is preferably less than 10,000, and more preferably 2,000 or more but less than 10,000.

[0135] In this invention, the weight-average molecular weight and number-average molecular weight are values ​​determined by gel permeation chromatography (GPC).

[0136] • Solvent (eluent): N-methylpyrrolidone

[0137] • Device Name: TOSOH HLC-8220GPC

[0138] • String: Connect 3 TOSOH TSKgelSuperAWM-H (6mm×15cm) tubes for use.

[0139] • Column temperature: 25℃

[0140] • Sample concentration: 0.1% by mass

[0141] • Flow rate: 0.35 mL / min

[0142] • Calibration curve: The calibration curve was obtained using seven samples of TSK standard polystyrene prepared by TOSOH CORPORATION with Mw = 2,800,000 to 1,050 (Mw / Mn = 1.03 to 1.06).

[0143] (Dichroic substances)

[0144] The light-absorbing anisotropic layer of the present invention preferably contains a dichroic material.

[0145] Dichroic substances are substances whose absorbance varies depending on the direction of light. There are no particular limitations on dichroic substances; for example, visible light absorbing substances (e.g., dichroic pigment compounds and dichroic azo pigment compounds), luminescent substances (e.g., fluorescent substances and phosphorescent substances), ultraviolet light absorbing substances, infrared light absorbing substances, nonlinear optical substances, carbon nanotubes, and inorganic substances (e.g., quantum rods) can be used. Conventionally known dichroic substances (dichroic pigment compounds) can also be used.

[0146] Among them, dichroic pigment compounds are preferred, and dichroic azo pigment compounds are more preferred.

[0147] There are no particular limitations on the dichroic azo dye compounds; conventionally known dichroic azo dye compounds can be used, but compounds described later are preferred.

[0148] The following describes dichroic azo dye compounds.

[0149] Dichroic azo dye compounds may or may not exhibit liquid crystal properties.

[0150] When a dichroic azo dye compound exhibits liquid crystal properties, it can exhibit either nematic or smectic properties. The temperature range for displaying the liquid crystal phase is preferably above room temperature and below 300°C, and more preferably 50 to 200°C from the viewpoint of operability and manufacturing suitability.

[0151] In the dichroic azo pigment compound, from the viewpoint of adjusting the hue, the light absorption anisotropy layer preferably has at least one pigment compound (hereinafter also referred to as "first dichroic azo pigment compound") having a maximum absorption wavelength in the wavelength range of 560 to 700 nm and at least one pigment compound (hereinafter also referred to as "second dichroic azo pigment compound") having a maximum absorption wavelength in the wavelength range of 455 nm or more and less than 560 nm. More preferably, it has at least the dichroic azo pigment compound represented by formula (3) described later and the dichroic azo pigment compound represented by formula (4) described later.

[0152] Furthermore, three or more dichroic azo pigment compounds may be used together. For example, from the viewpoint of making the light absorption anisotropic layer close to black, it is preferable to use a first dichroic azo pigment compound, a second dichroic azo pigment compound, and at least one pigment compound having a maximum absorption wavelength in the range of 380 nm or more and less than 455 nm (hereinafter also referred to as "third dichroic azo pigment compound").

[0153] Furthermore, from the viewpoint of improving compressive strength, dichroic azo dye compounds preferably have crosslinking groups.

[0154] Examples of crosslinking groups include (meth)acryloyl, epoxy, oxocyclobutyl, and styryl, with (meth)acryloyl being preferred.

[0155] -First dichroic azo pigment compound-

[0156] As described above, the first dichroic azo dye compound is a dichroic azo dye compound with a large absorption wavelength in the wavelength range of 560 to 700 nm.

[0157] The first dichroic azo dye compound is preferably a dichroic azo dye compound having a maximum absorption wavelength in the wavelength range of 560 to 700 nm. From the viewpoint of adjusting the hue of the polarizer, it is more preferably a dichroic azo dye compound having a maximum absorption wavelength in the wavelength range of 560 to 650 nm, and even more preferably a dichroic azo dye compound having a maximum absorption wavelength in the wavelength range of 560 to 640 nm.

[0158] The maximum absorption wavelength (nm) of the dichroic azo dye compound in this specification is determined based on the ultraviolet-visible spectrum in the wavelength range of 380–800 nm obtained by using a spectrophotometer to measure a solution of the dichroic azo dye compound dissolved in a good solvent.

[0159] The first dichroic azo dye compound is preferably a compound having a chromophore and a side chain bonded to the end of the chromophore.

[0160] Specific examples of chromophores include aromatic cyclic groups (e.g., aromatic hydrocarbon groups, aromatic heterocyclic groups), azo groups, etc., preferably having both aromatic cyclic groups and azo groups, and more preferably having a bisazo structure having an aromatic heterocyclic group (preferably thienothiazolyl) and two azo groups.

[0161] As a side chain, there are no particular limitations; for example, L in equation (3) discussed later. 3 R 2 or L 4 The group represented.

[0162] From the viewpoint of further improving the orientation degree of the dichroic azo dye compound in the formed light-absorbing anisotropic layer, the first dichroic azo dye compound is preferably the compound represented by the following formula (3).

[0163] [Chemical Formula 6]

[0164]

[0165] In equation (3), A 4 This indicates a divalent aromatic group that can have substituents.

[0166] In equation (3), L 3 and L 4 Substituents are represented independently.

[0167] In equation (3), E represents any one of the nitrogen, oxygen and sulfur atoms.

[0168] In equation (3), R 1It represents a hydrogen atom, a halogen atom, an alkyl group that may have substituents, or an alkoxy group that may have substituents.

[0169] In equation (3), R 2 It represents a hydrogen atom or an alkyl group that may have substituents.

[0170] In equation (3), R 3 It represents a hydrogen atom or a substituent.

[0171] In equation (3), n represents 0 or 1. Specifically, n is 1 when E is a nitrogen atom, and n is 0 when E is an oxygen atom or a sulfur atom.

[0172] Furthermore, the aforementioned substituent is preferably substituent W.

[0173] In equation (3), for A 4 The term "a divalent aromatic group that may have substituents" is explained.

[0174] As the aforementioned substituents, examples include the substituent group G described in paragraphs

[0237] to

[0240] of Japanese Patent Application Publication No. 2011-237513. Among them, halogen atoms, alkyl groups, alkoxy groups, alkoxy carbonyl groups (e.g., methoxy carbonyl, ethoxy carbonyl, etc.), aryloxy carbonyl groups (e.g., phenoxy carbonyl, 4-methylphenoxy carbonyl, 4-methoxyphenyl carbonyl, etc.) are preferred, alkyl groups are more preferred, and alkyl groups having 1 to 5 carbon atoms are even more preferred.

[0175] On the other hand, examples of divalent aromatic groups include divalent aromatic hydrocarbon groups and divalent aromatic heterocyclic groups.

[0176] Examples of divalent aromatic hydrocarbon groups include arylene groups with 6 to 12 carbon atoms, specifically phenylene, cumenylene group, mesitylene, tolylene group, and xylene group. Among these, phenylene is preferred.

[0177] In equation (3), L is used as 3 and L 4The substituent represented can be exemplified by substituent W. The substituent is preferably an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an oxycarbonyl group, an acyloxy group, an amide group, an amino group, an alkoxycarbonylamino group, a sulfonylamino group, an aminosulfonyl group, a carbamoyl group, an alkylthio group, a sulfonyl group, a ureyl group, a nitro group, a hydroxyl group, a cyano group, an imino group, an azo group, a halogen atom, or a heteroatom-containing cyclic group. More preferably, it is an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an oxycarbonyl group, an acyloxy group, an amino group, a nitro group, an imino group, or an azo group.

[0178] Preferred L 3 and L 4 At least one of them contains a crosslinking group (polymerizing group), more preferably L 3 and L 4 Both of these contain cross-linking groups.

[0179] As a crosslinking group, specifically, the polymerizable groups described in paragraphs

[0040] to

[0050] of Japanese Patent Application Publication No. 2010-244038 are preferred. From the viewpoint of reactivity and suitability for synthesis, acryloyl, methacryloyl, epoxy, oxetyl or styryl are preferred, with acryloyl or methacryloyl being more preferred.

[0180] In formula (3), E represents any one of nitrogen, oxygen and sulfur atoms, and from the viewpoint of suitability for synthesis, nitrogen atom is preferred.

[0181] In equation (3), R 1 It represents any one of the following groups or atoms: hydrogen atom, halogen atom, alkyl group that may have substituents, and alkoxy group that may have substituents, preferably hydrogen atom or alkyl group that may have substituents.

[0182] Examples of substituents mentioned above include halogen atoms.

[0183] Examples of alkyl groups include straight-chain, branched, or cyclic alkyl groups having 1 to 8 carbon atoms. Among these, straight-chain alkyl groups having 1 to 6 carbon atoms are preferred, straight-chain alkyl groups having 1 to 3 carbon atoms are more preferred, and methyl or ethyl groups are even more preferred.

[0184] Examples of alkoxy groups include those with 1 to 8 carbon atoms. Among these, alkoxy groups with 1 to 6 carbon atoms are preferred, alkoxy groups with 1 to 3 carbon atoms are more preferred, and methoxy or ethoxy groups are even more preferred.

[0185] In equation (3), R 2 The alkyl group represents a hydrogen atom or may have substituents, preferably an alkyl group that may have substituents.

[0186] R 2 The specific examples and preferred embodiments of "alkyl groups that may have substituents" are the same as R in formula (3) above. 1 The phrase "can have alkyl groups" is the same as the one in the text, so its description is omitted.

[0187] In equation (3), R 3 It represents a hydrogen atom or a substituent.

[0188] R 3 The specific examples and preferred methods of the "substituents" referred to are the same as those of the substituents in the above-mentioned "divalent aromatic groups that may have substituents", and the preferred methods are also the same, so their descriptions are omitted.

[0189] From the point of view of lightfastness, L 3 Preferably, it has an electron-withdrawing group, R 2 and L 4 Preferably, the group has low electron-donating ability.

[0190] As a specific example of such a group, as L 3 Examples of R groups include alkylsulfonyl, alkylcarbonyl, alkoxycarbonyl, acyloxy, alkylsulfonylamino, alkylaminosulfonyl, alkylsulfinyl, and alkylurea. 2 and L 4 Examples of such groups include those with the following structures. Furthermore, groups with the following structures in formula (3) above contain R. 2 and L 4 The morphological representation of the bonded nitrogen atoms.

[0191] [Chemical Formula 7]

[0192]

[0193] The following are specific examples of first dichroic azo dye compounds, but are not limited to these.

[0194] [Chemical Formula 8]

[0195]

[0196]

[0197] -Second dichroic azo pigment compound-

[0198] The second dichroic azo dye compound is a different compound from the first dichroic azo dye compound; specifically, it has a different chemical structure.

[0199] Furthermore, as described above, the second dichroic azo dye compound is a dichroic azo dye compound having a large absorption wavelength in the range of wavelengths above 455 nm and below 560 nm.

[0200] From the viewpoint of adjusting the hue of the polarizer, the second dichroic azo dye compound is preferably a dichroic azo dye compound having a maximum absorption wavelength in the range of wavelengths above 455 nm and below 560 nm, more preferably a dichroic azo dye compound having a maximum absorption wavelength in the range of wavelengths from 455 to 555 nm, and even more preferably a dichroic azo dye compound having a maximum absorption wavelength in the range of wavelengths from 455 to 550 nm.

[0201] In particular, it is easier to adjust the hue of the polarizer by using a first dichroic azo dye compound with a maximum absorption wavelength of 560–700 nm and a second dichroic azo dye compound with a maximum absorption wavelength of 455 nm or more but less than 560 nm.

[0202] The second dichroic azo pigment compound is preferably a compound having a chromophore as the core of the dichroic azo pigment compound and a side chain bonded to the end of the chromophore.

[0203] Specific examples of chromophores include aromatic cyclic groups (e.g., aromatic hydrocarbon groups, aromatic heterocyclic groups), azo groups, etc., preferably having both aromatic hydrocarbon groups and azo groups, and more preferably having diazo or triazo structures having aromatic hydrocarbon groups and two or three azo groups.

[0204] As a side chain, it is not particularly limited, and examples can be the groups represented by R4, R5 or R6 in formula (4) described later.

[0205] From the viewpoint of further improving the orientation degree of the polarizer, the second dichroic azo dye compound is preferably the compound represented by formula (4).

[0206] Equation (4)

[0207] [Chemical Formula 9]

[0208]

[0209] In equation (4), n represents 1 or 2.

[0210] In formula (4), Ar3, Ar4, and Ar5 independently represent either a phenylene group that may have substituents or a heterocyclic group that may have substituents. There are no particular restrictions on the substituents; for example, substituent W can be cited.

[0211] As a heterocyclic group, it can be either aromatic or non-aromatic.

[0212] Examples of atoms other than carbon that constitute an aromatic heterocyclic group include nitrogen, sulfur, and oxygen atoms. When an aromatic heterocyclic group has multiple atoms that form the ring besides carbon, these atoms may be the same or different.

[0213] Specific examples of aromatic heterocyclic groups include, for instance, pyridinyl (pyridine-diyl), pyridazinyl (pyridinyl), imidazole-diyl, thiophenyl (thiophene-diyl), quinolineyl (quinoline-diyl), isoquinolineyl (isoquinoline-diyl), oxazole-diyl, thiazole-diyl, oxadiazole-diyl, benzothiazole-diyl, benzothiadiazole-diyl, phthalimide-diyl, thienothiazole-diyl, thiazonothiazole-diyl, thienothiphene-diyl, and thienooxazole-diyl.

[0214] In equation (4), R4 is defined the same as L in equation (3). 3 same.

[0215] In equation (4), the definitions of R5 and R6 are the same as those of R in equation (3). 2 and L 4 same.

[0216] From the viewpoint of lightfastness, R4 is preferably an electron-withdrawing group, and R5 and R6 are preferably groups with low electron-donating properties.

[0217] In this type of group, specific examples of R4 being an electron-withdrawing group are similar to L. 3 The specific examples are the same when R5 and R6 are electron-withdrawing groups; the specific examples are the same when R5 and R6 are groups with low electron-donating properties. 2 and L 4 The specific examples are the same when the group has low electron-donating ability.

[0218] The following are specific examples of dichroic azo dye compounds, but are not limited to them.

[0219] [Chemical Formula 10]

[0220]

[0221]

[0222]

[0223]

[0224] -Difference in logP values-

[0225] The logP value is one of the indicators that reflects the hydrophilic and hydrophobic properties of a chemical structure.

[0226] The absolute value of the difference between the logP value of the side chain of the first dichroic azo dye compound and the logP value of the side chain of the second dichroic azo dye compound (hereinafter also referred to as "logP difference") is preferably 2.30 or less, more preferably 2.0 or less, even more preferably 1.5 or less, and particularly preferably 1.0 or less. If the logP difference is 2.30 or less, the affinity between the first dichroic azo dye compound and the second dichroic azo dye compound is improved, making it easier to form an arrangement structure, and thus the orientation degree of the dichroic azo dye compound is further improved.

[0227] Furthermore, in the presence of side chains of multiple first dichroic azo dye compounds or second dichroic azo dye compounds, it is preferable that at least one logP difference satisfies the above value.

[0228] Here, the side chains of the first and second dichroic azo dye compounds refer to the groups bonded to the ends of the chromophores. For example, when the first dichroic azo dye compound is a compound represented by formula (3), L in formula (3) 3 L 4 and R 2 As side chains, when the second dichroic azo dye compound is a compound represented by formula (4), R4, R5, and R6 in formula (4) are side chains. In particular, when the first dichroic azo dye compound is a compound represented by formula (3) and the second dichroic azo dye compound is a compound represented by formula (4), L is preferred. 3 The difference between the logP value and R4, L 3 The difference between the logP value and R5, L 4 The difference between the logP value and R4 and L 4 At least one of the logP differences between R5 and R5 satisfies the above value.

[0229] Furthermore, the logP value is sometimes referred to as the hydrophilicity / hydrophobicity parameter. The logP value can be calculated using software such as ChemBioDraw Ultra or HSPiP (Ver. 4.1.07). It can also be experimentally determined using methods such as those outlined in OECD Guidelines for the Testing of Chemicals, Section 1, Test No. 117. In this specification, unless otherwise specified, the logP value is the value calculated by inputting the structural formula of the compound into HSPiP (Ver. 4.1.07).

[0230] -Third dichroic azo pigment compound-

[0231] The third dichroic azo pigment compound is a dichroic azo pigment compound other than the first and second dichroic azo pigment compounds. Specifically, its chemical structure differs from that of the first and second dichroic azo pigment compounds. The presence of the third dichroic azo pigment compound in the light-absorbing anisotropic layer offers the advantage of easily adjusting the hue of the light-absorbing anisotropic layer.

[0232] Furthermore, as described above, the third dichroic azo dye compound is a dichroic azo dye compound that has a very large absorption wavelength in the range of wavelengths above 380 nm and below 455 nm.

[0233] From the viewpoint of polarizer hue adjustment, the third dichroic azo dye compound is preferably a dichroic azo dye compound having a maximum absorption wavelength in the range of wavelengths above 380 nm and below 455 nm, more preferably a dichroic azo dye compound having a maximum absorption wavelength in the range of wavelengths from 400 to 455 nm, and even more preferably a dichroic azo dye compound having a maximum absorption wavelength in the range of wavelengths from 410 to 455 nm.

[0234] The third dichroic azo dye compound preferably contains the dichroic azo dye compound represented by the following formula (6).

[0235] [Chemical Formula 11]

[0236]

[0237] In formula (6), A and B independently represent crosslinking groups or monovalent substituents, respectively.

[0238] In equation (6), a and b represent 0 or 1 independently, respectively. Considering the excellent orientation at 420 nm, it is preferable that both a and b are 0.

[0239] In equation (6), when a = 0, L1 represents a monovalent substituent, and when a = 1, L1 represents a single bond or a divalent linking group. Furthermore, when b = 0, L2 represents a monovalent substituent, and when b = 1, L2 represents a single bond or a divalent linking group.

[0240] In formula (6), Ar1 represents an aromatic hydrocarbon group or heterocyclic group with a valence of (n1+2), Ar2 represents an aromatic hydrocarbon group or heterocyclic group with a valence of (n2+2), and Ar3 represents an aromatic hydrocarbon group or heterocyclic group with a valence of (n3+2).

[0241] In equation (6), R1, R2, and R3 independently represent monovalent substituents. When n1≥2, multiple R1s can be the same or different from each other; when n2≥2, multiple R2s can be the same or different from each other; and when n3≥2, multiple R3s can be the same or different from each other.

[0242] In equation (6), k represents an integer from 1 to 4. When k ≥ 2, multiple Ar2 can be the same or different from each other, and multiple R2 can be the same or different from each other.

[0243] In equation (6), n1, n2, and n3 independently represent integers from 0 to 4. Specifically, when k = 1, n1 + n2 + n3 ≥ 0, and when k ≥ 2, n1 + n2 + n3 ≥ 1.

[0244] In formula (6), the crosslinking groups represented by A and B can be, for example, the polymerizable groups described in paragraphs

[0040] to

[0050] of Japanese Patent Application Publication No. 2010-244038. Among these, from the viewpoint of improving reactivity and synthetic applicability, acryloyl, methacryloyl, epoxy, oxetyl, and styrene are preferred, and from the viewpoint of further improving solubility, acryloyl and methacryloyl are more preferred.

[0245] In equation (6), substituents represented by A and B with a 1 valence, such as substituent W, can be used as an example.

[0246] The monovalent substituents represented by L1 and L2 are preferably groups introduced to improve the solubility of dichroic substances or groups with electron-donating or electron-withdrawing properties introduced to adjust the hue of the pigment. For example, substituent W can be cited as a substituent.

[0247] Substituent W can be further replaced by substituent W. Furthermore, when there are two or more substituents, they can be the same or different. And, where possible, they can bond together to form a ring.

[0248] As a group in which the above-mentioned substituent W is further replaced by the above-mentioned substituent W, for example, a group in which an alkoxy group is replaced by an alkyl group, i.e., R. B -(OR A ) na -Groups in which the carboxyl group is replaced by an alkyl group are called R groups. B -OCO-R A -Base. Wherein, R A R represents an alkylene group having 1 to 5 carbon atoms. B The alkyl group represents 1 to 5 carbon atoms, and na represents an integer from 1 to 10 (preferably 1 to 5, more preferably 1 to 3).

[0249] Among them, the substituents with a monovalent valence represented by L1 and L2 are preferably alkyl, alkenyl, alkoxy, and groups in which these groups are further substituted (e.g., R mentioned above). B -(OR A ) na -Base and R B -OCO-R A - group), more preferably alkyl, alkoxy, and groups further substituted by these groups (e.g., the R group mentioned above). B -(OR A ) na -Base and R B -OCO-R A -base).

[0250] Examples of divalent linking groups represented by L1 and L2 include -O-, -S-, -CO-, -COO-, -OCO-, -O-CO-O-, and -CO-NR. N -、-O-CO-NR N -、-NR N -CO-NR N -, -SO2-, -SO-, alkylene, cycloalkylene and alkenyl groups, and groups formed by combining two or more of these groups.

[0251] Preferably, the group is formed by combining an alkylene group with one or more groups selected from the group consisting of -O-, -COO-, -OCO- and -O-CO-O-, and more preferably, the group is formed by combining an alkylene group with -OCO-.

[0252] Among them, R N Represents a hydrogen atom or an alkyl group. In the presence of multiple R... N In the case of multiple R N They can be the same or different.

[0253] From the viewpoint of further improving the solubility of dichroic substances, the number of atoms in the main chain of at least one of L1 and L2 is preferably 3 or more, more preferably 5 or more, even more preferably 7 or more, and particularly preferably 10 or more. Furthermore, the upper limit of the number of atoms in the main chain is preferably 20 or less, more preferably 12 or less.

[0254] On the other hand, from the viewpoint that the orientation degree of the dichroic material in the light-absorbing anisotropic layer is further improved, the number of atoms in the main chain of at least one of L1 and L2 is preferably 1 to 5.

[0255] Here, in the case of A in equation (6), the "main chain" in L1 refers to the portion required to directly link the "O" atom connected to L1 and "A", and the "number of atoms in the main chain" refers to the number of atoms constituting the aforementioned portion. Similarly, in the case of B in equation (6), the "main chain" in L2 refers to the portion required to directly link the "O" atom connected to L2 and "B", and the "number of atoms in the main chain" refers to the number of atoms constituting the aforementioned portion. In addition, the "number of atoms in the main chain" does not include the number of atoms in the side chains, which will be described later.

[0256] Furthermore, in the absence of A, the "number of atoms in the main chain" in L1 refers to the number of atoms in L1 without branches. In the absence of B, the "number of atoms in the main chain" in L2 refers to the number of atoms in L2 without branches.

[0257] Specifically, in equation (D1) below, the main chain of L1 has 5 atoms (the number of atoms in the dashed box on the left side of equation (D1) below), and the main chain of L2 has 5 atoms (the number of atoms in the dashed box on the right side of equation (D1) below). Furthermore, in equation (D10) below, the main chain of L1 has 7 atoms (the number of atoms in the dashed box on the left side of equation (D10) below), and the main chain of L2 has 5 atoms (the number of atoms in the dashed box on the right side of equation (D10) below).

[0258] [Chemical Formula 12]

[0259]

[0260] L1 and L2 can have branches.

[0261] Here, when A is present in equation (6), the “branch” in L1 refers to the portion other than the portion required for directly connecting the “O” atom and “A” connected to L1 in equation (6). Similarly, when B is present in equation (6), the “branch” in L2 refers to the portion other than the portion required for directly connecting the “O” atom and “B” connected to L2 in equation (6).

[0262] Furthermore, in the absence of A in equation (6), the “branch” in L1 refers to the portion other than the longest atomic chain (i.e., the main chain) stretched from the “O” atom connected to L1 in equation (6). Similarly, in the absence of B in equation (6), the “branch” in L2 refers to the portion other than the longest atomic chain (i.e., the main chain) stretched from the “O” atom connected to L2 in equation (6).

[0263] The number of atoms in the branched chain is preferably 3 or less. Having 3 or less of atoms in the branched chain offers advantages such as further improving the orientation of dichroic substances in the anisotropic light absorption layer. Furthermore, the number of atoms in the branched chain does not include hydrogen atoms.

[0264] In formula (6), Ar1 represents an aromatic hydrocarbon group or a heterocyclic group with a valence of (n1+2) (e.g., a valence of 3 when n1 is 1), Ar2 represents an aromatic hydrocarbon group or a heterocyclic group with a valence of (n2+2) (e.g., a valence of 3 when n2 is 1), and Ar3 represents an aromatic hydrocarbon group or a heterocyclic group with a valence of (n3+2) (e.g., a valence of 3 when n3 is 1). In other words, Ar1 to Ar3 are respectively divalent aromatic hydrocarbon groups or divalent heterocyclic groups substituted by n1 to n3 substituents (R1 to R3 described later).

[0265] The divalent aromatic hydrocarbon group represented by Ar1 to Ar3 can be a monocyclic ring or a fused ring structure with more than two rings. From the viewpoint of further improving solubility, the number of rings of the divalent aromatic hydrocarbon group is preferably 1 to 4, more preferably 1 to 2, and even more preferably 1 (i.e., phenylene).

[0266] Specific examples of divalent aromatic hydrocarbon groups include phenylene, azulene-diyl, naphthylene, fluorene-diyl, anthracene-diyl, and tetraphenyl-diyl. From the viewpoint of further improving solubility, phenylene and naphthylene are preferred, and phenylene is more preferred.

[0267] The following are specific examples of trichromatic pigment compounds, but the present invention is not limited thereto. Furthermore, in the following specific examples, n represents an integer from 1 to 10.

[0268] [Chemical Formula 13]

[0269]

[0270] [Chemical Formula 14]

[0271]

[0272] Furthermore, it is preferable that the third pigment has a structure without free radical polymerizable groups. In the case of a structure without free radical polymerizable groups, the orientation degree is excellent when the wavelength for measuring the orientation degree, as described later, is 420 nm.

[0273] Regarding structures that do not have free radical polymerizable groups, the following structures can be cited as examples.

[0274] [Chemical Formula 15]

[0275]

[0276] From the viewpoint that orientation is particularly superior at a wavelength of 420 nm for the orientation measurement described later, the third dichroic azo dye compound is more preferably a dichroic azo dye compound having the structure represented by the following formula (1-1).

[0277] [Chemical Formula 16]

[0278]

[0279] In equation (1-1), the definitions of R1, R3, n1, n3, L1 and L2 are the same as those of R1, R3, n1, n3, L1 and L2 in equation (6).

[0280] In equation (1-1), R4 and R5 are defined in the same way as substituent W.

[0281] In equation (1-1), R 21 and R 22 The definition of each is independently the same as R2 in equation (6).

[0282] In equation (1-1), the definitions of n21 and n22 are independently the same as n2 in equation (6).

[0283] n1+n21+n22+n3≥1, n1+n21+n22+n3 is preferably 1 to 9, and more preferably 1 to 5.

[0284] The following are specific examples of third dichroic azo dye compounds, but the invention is not limited thereto.

[0285] [Chemical Formula 17]

[0286]

[0287] [Chemical Formula 18]

[0288]

[0289] [Chemical Formula 19]

[0290]

[0291] [Composition for forming anisotropic light-absorbing layers]

[0292] The optical film of the present invention has an anisotropic light absorption layer, which is preferably made by using a composition for forming an anisotropic light absorption layer containing a liquid crystal compound and a dichroic substance.

[0293] The composition for forming a light-absorbing anisotropic layer may contain components other than liquid crystal compounds and dichroic substances, such as solvents, surface modifiers, vertical alignment agents, polymerizable components, polymerization initiators (e.g., free radical polymerization initiators), leveling agents suitable for vertical alignment, etc. In this case, the light-absorbing anisotropic layer of the present invention includes solid components other than liquid components (solvents, etc.).

[0294] The composition of the composition for forming anisotropic light-absorbing layers will be described below.

[0295] Furthermore, the liquid crystal compound and dichroic material described above can be used, and the preferred method is also as described above.

[0296] (solvent)

[0297] The composition for forming anisotropic light-absorbing layers preferably contains a solvent.

[0298] Examples of solvents include ketones (e.g., acetone, 2-butanone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone), ethers (e.g., dioxane, tetrahydrofuran, 2-methyltetrahydrofuran, cyclopentyl methyl ether, tetrahydropyran, and dioxolane), aliphatic hydrocarbons (e.g., hexane), alicyclic hydrocarbons (e.g., cyclohexane), aromatic hydrocarbons (e.g., benzene, toluene, xylene, and trimethylbenzene), halogenated carbons (e.g., dichloromethane, trichloromethane, dichloroethane, dichlorobenzene, and chlorotoluene), and esters (e.g., acetic acid). Organic solvents such as methyl esters, ethyl acetate, butyl acetate, and ethyl lactate, alcohols (e.g., ethanol, isopropanol, butanol, cyclohexanol, isoamyl alcohol, neopentyl alcohol, diacetone alcohol, and benzyl alcohol), cellosols (e.g., methyl cellosol, ethyl cellosol, and 1,2-dimethoxyethane), cellosol acetates, sulfoxides (e.g., dimethyl sulfoxide), amides (e.g., dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and N-ethylpyrrolidone), and heteroatom-containing cyclic compounds (e.g., pyridine), as well as water. One of these solvents may be used alone, or two or more may be used simultaneously.

[0299] Among these solvents, ketones (especially cyclopentanone and cyclohexanone), ethers (especially tetrahydrofuran, cyclopentyl methyl ether, tetrahydropyran and dioxolane), alcohols (especially benzyl alcohol), and amides (especially dimethylformamide, dimethylacetamide, N-methylpyrrolidone and N-ethylpyrrolidone) are preferred.

[0300] When the liquid crystal composition contains a solvent, the solvent content is preferably 80-99% by mass, more preferably 83-98% by mass, and even more preferably 85-96% by mass, relative to the total mass of the liquid crystal composition.

[0301] When two or more solvents are involved, the solvent content mentioned above refers to the total content of the solvents.

[0302] (Surface modifier)

[0303] The composition for forming anisotropic light-absorbing layers preferably contains a surface modifier.

[0304] As a surface modifier, the surface modifier described in the Examples section below can be used.

[0305] When the coloring composition contains a surface modifier, the content of the surface modifier is preferably 0.001 to 5 parts by mass relative to the total of 100 parts by mass of the dichroic pigment compound and the liquid crystal compound in the coloring composition.

[0306] (Vertical Orientation Agent)

[0307] The composition for forming anisotropic light-absorbing layers preferably contains a vertical alignment agent.

[0308] Vertical orientation agent refers to a substance that can cause dichroic substances to be vertically oriented.

[0309] Examples of vertical orientation agents include boric acid compounds and onium salts.

[0310] As a boric acid compound, the compound represented by formula (30) is preferred.

[0311] Equation (30)

[0312] [Chemical Formula 20]

[0313]

[0314] In equation (30), R 1 and R 2 Each of these can be independently represented as a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroatom-containing cyclic group.

[0315] R3 This indicates a substituent containing a functional group bonded to a (meth)acrylate group. Wherein, R... 3 Preferably, it is a substituted or unsubstituted aliphatic hydrocarbon group, aryl group, or heteroatom-containing cyclic group having a functional group bonded to (meth)acrylic acid group.

[0316] Examples of functional groups obtained by bonding with an acrylate group include polymerizable groups such as vinyl, acrylate, methacrylate, acrylamide, styrene, vinyl ketone, butadiene, vinyl ether, ethylene oxide, aziridinyl, and oxetane. Preferably, vinyl, acrylate, methacrylate, styrene, ethylene oxide, or oxetane are used; more preferably, vinyl, acrylate, acrylamide, or styrene are used.

[0317] As a specific example of boric acid compounds, one can cite the boric acid compounds represented by general formula (I) as described in paragraphs 0023 to 0032 of Japanese Patent Application Publication No. 2008-225281.

[0318] The following compounds are also preferred as boric acid compounds.

[0319] [Chemical Formula 21]

[0320]

[0321] As an onium salt, the compound represented by formula (31) is preferred.

[0322] Equation (31)

[0323] [Chemical Formula 22]

[0324]

[0325] In formula (31), ring A represents a quaternary ammonium ion composed of a nitrogen-containing heterocycle. X represents an anion. L 1 This indicates a divalent linker group. L 2 Indicates a single bond or a divalent linking group. Y 1 The symbol indicates a divalent linking group having a 5- or 6-membered ring as part of the structure. Z indicates a divalent linking group having 2 to 20 alkylene groups as part of the structure. P 1 and P 2 Each of these represents a monovalent substituent that has a polymerizable alkene unsaturated bond.

[0326] Specific examples of onium salts include those described in paragraphs 0052 to 0058 of Japanese Patent Application Publication No. 2012-208397, those described in paragraphs 0024 to 0055 of Japanese Patent Application Publication No. 2008-026730, and those described in Japanese Patent Application Publication No. 2002-37777.

[0327] The content of the vertical alignment agent in the composition for forming the light-absorbing anisotropic layer is preferably 0.1 to 400% by mass, more preferably 0.5 to 350% by mass, relative to the total mass of the liquid crystal compound.

[0328] Vertical alignment agents can be used alone or in combination of two or more. When using two or more vertical alignment agents, their combined dosage is preferably within the range described above.

[0329] -Leveling agents suitable for vertical orientation-

[0330] When a dichroic substance is vertically oriented using a light-absorbing anisotropic layer forming composition containing a vertical alignment agent, it is preferable that the light-absorbing anisotropic layer forming composition contains a leveling agent. If the light-absorbing anisotropic layer forming composition contains a leveling agent, surface roughness caused by drying air applied to the surface of the anisotropic light-absorbing layer is suppressed, thereby further homogenizing the dichroic substance.

[0331] There are no particular restrictions on leveling agents, but leveling agents containing fluorine atoms (fluorine-based leveling agents) or leveling agents containing silicon atoms (silicone-based leveling agents) are preferred, and fluorine-based leveling agents are more preferred.

[0332] Examples of fluorinated leveling agents include fatty acid esters of polycarboxylic acids in which a portion of the fatty acid is replaced by a fluorinated alkyl group, and polyacrylates having fluorinated substituents. In particular, when rod-shaped compounds are used as dichroic substances and liquid crystal compounds, leveling agents containing repeating units derived from compounds represented by formula (40) are preferred from the viewpoint of promoting the vertical orientation of dichroic substances and liquid crystal compounds.

[0333] Equation (40)

[0334] [Chemical Formula 23]

[0335]

[0336] R 0 It represents a hydrogen atom, a halogen atom, or a methyl group.

[0337] L represents a divalent linking group. Preferably, L is an alkylene group having 2 to 16 carbon atoms, and any non-adjacent -CH2- in the above alkylene group can be replaced by -O-, -COO-, -CO- or -CONH-.

[0338] n represents an integer from 1 to 18.

[0339] Leveling agents having repeating units derived from compounds represented by formula (40) may also contain other repeating units.

[0340] Other repeating units can be cited from repeating units derived from compounds represented by formula (41).

[0341] Equation (41)

[0342] [Chemical Formula 24]

[0343]

[0344] R 11 It represents a hydrogen atom, a halogen atom, or a methyl group.

[0345] X represents an oxygen atom, a sulfur atom, or -N(R) 13 )-. R 13 It represents an alkyl group having 1 to 8 hydrogen atoms or carbon atoms.

[0346] R 12 The alkyl group represents a hydrogen atom, and may have substituents, such as an alkyl group or an aromatic group. Furthermore, the alkyl group preferably has 1 to 20 carbon atoms. The alkyl group can be linear, branched, or cyclic.

[0347] Furthermore, examples of substituents that the aforementioned alkyl groups may have include poly(alkoxide) groups and polymerizable groups. Examples of polymerizable groups are as described above.

[0348] When the leveling agent contains repeating units derived from the compound represented by formula (40) and repeating units derived from the compound represented by formula (41), the content of repeating units derived from the compound represented by formula (40) is preferably 10 to 95 mol% relative to the total repeating units included in the leveling agent, and more preferably 15 to 90 mol%.

[0349] When the leveling agent contains repeating units derived from the compound represented by formula (40) and repeating units derived from the compound represented by formula (41), the content of repeating units derived from the compound represented by formula (41) is preferably 10 to 90 mol% relative to the total repeating units included in the leveling agent, and more preferably 20 to 80 mol%.

[0350] Furthermore, as a leveling agent, one can also be an example of a leveling agent that replaces the repeating unit of the compound represented by formula (40) and contains the repeating unit of the compound represented by formula (42).

[0351] Equation (42)

[0352] [Chemical Formula 25]

[0353]

[0354] R 2 It represents a hydrogen atom, a halogen atom, or a methyl group.

[0355] L 2 This indicates a divalent linker group.

[0356] n represents an integer from 1 to 18.

[0357] Specific examples of leveling agents include the compounds illustrated in paragraphs 0046 to 0052 of Japanese Patent Application Publication No. 2004-331812 and the compounds described in paragraphs 0038 to 0052 of Japanese Patent Application Publication No. 2008-257205.

[0358] The leveling agent content in the composition is preferably 0.001 to 10% by mass relative to the total mass of the liquid crystal compound, more preferably 0.01 to 5% by mass.

[0359] Leveling agents can be used alone or in combination of two or more. When using two or more leveling agents, their combined dosage is preferably within the range mentioned above.

[0360] (polymeric components)

[0361] The composition for forming anisotropic light-absorbing layers preferably contains overlapping components.

[0362] As a polymerizable component, examples include compounds containing acrylates (e.g., acrylate monomers). In this case, the light-absorbing anisotropic layer of the present invention comprises a polyacrylate obtained by polymerizing a compound containing the aforementioned acrylate. Specifically, examples include the compound described in paragraph 0058 of Japanese Patent Application Publication No. 2017-122776.

[0363] When the composition for forming anisotropic light-absorbing layers contains a polymerizable component, the content of the polymerizable component is preferably 3 to 20 parts by mass relative to the total of 100 parts by mass of the dichroic substance and the liquid crystal compound in the composition for forming anisotropic light-absorbing layers.

[0364] (Polymerization initiator)

[0365] The composition for forming anisotropic light-absorbing layers preferably contains a superimposed initiator.

[0366] There are no particular restrictions on the type of polymerization initiator, but photosensitive compounds, i.e., photopolymerization initiators, are preferred.

[0367] As photopolymerization initiators, a wide variety of compounds can be used without particular limitations. Examples of photopolymerization initiators include α-carbonyl compounds (as described in U.S. Patent Nos. 2,367,661 and 2,367,670), azobinyl ethers (as described in U.S. Patent No. 2,448,828), α-hydrocarbon-substituted aromatic azobinyl compounds (as described in U.S. Patent No. 2,722,512), polynuclear quinone compounds (as described in U.S. Patent Nos. 3,046,127 and 2,951,758), and combinations of triarylimidazolium dimers and p-aminophenyl ketones (as described in U.S. Patent No. 3,549,367). Acridine and phenazine compounds (Japanese Patent Application Publication No. 60-105667 and US Patent No. 4239850), oxadiazole compounds (US Patent No. 4212970), o-acyl oxime compounds (paragraph

[0065] of Japanese Patent Application Publication No. 2016-27384), and acylphosphine oxide compounds (Japanese Patent Application Publication No. 63-40799, Japanese Patent Application Publication No. 5-29234, Japanese Patent Application Publication No. 10-95788, and Japanese Patent Application Publication No. 10-29997), etc.

[0368] Commercially available products can also be used as photopolymerization initiators, such as BASF's IRGACURE 184, IRGACURE 907, IRGACURE 369, IRGACURE 651, IRGACURE 819, IRGACURE 2959, IRGACURE OXE-01, and IRGACURE OXE-02.

[0369] When the composition for forming an anisotropic light-absorbing layer contains a polymerization initiator, the content of the polymerization initiator is preferably 0.01 to 30 parts by mass, more preferably 0.1 to 15 parts by mass, relative to the total of 100 parts by mass of the dichroic substance and the polymeric liquid crystal compound in the composition for forming anisotropic light-absorbing layer. When the content of the polymerization initiator is 0.01 parts by mass or more, the durability of the anisotropic light-absorbing film becomes better; when it is 30 parts by mass or less, the orientation degree of the dichroic substance in the anisotropic light-absorbing layer becomes better.

[0370] A polymerization initiator can be used alone or in combination with two or more. When two or more polymerization initiators are used, it is preferable that their total amount is within the range described above.

[0371] (Content of dichroic substances)

[0372] The content of the dichroic substance relative to the total solid content of the light-absorbing anisotropic layer is preferably 10 to 30% by mass, more preferably 15 to 30% by mass, even more preferably 18 to 28% by mass, and particularly preferably 20 to 26% by mass. The total solid content refers to the mass of the composition for forming the light-absorbing anisotropic layer after removing the solvent component.

[0373] If the content of the dichroic substance is within the above range, a highly oriented anisotropic light absorption layer can be obtained even when the light absorption anisotropic layer is a thin film. Therefore, it is easy to obtain a flexible anisotropic light absorption layer.

[0374] The content of the first dichroic azo dye compound is preferably 40 to 90 parts by mass relative to 100 parts by mass of the total dichroic substance, and more preferably 45 to 75 parts by mass.

[0375] The content of the second dichroic azo dye compound is preferably 6 to 50 parts by mass relative to 100 parts by mass of the total dichroic substance, and more preferably 8 to 35 parts by mass.

[0376] The content of the third dichroic azo dye compound is preferably 3 to 50 parts by mass relative to 100 parts by mass of the dichroic azo dye compound content, more preferably 5 to 40 parts by mass.

[0377] To adjust the hue of the light-absorbing anisotropic layer, the content ratios of the first dichroic azo pigment compound, the second dichroic azo pigment compound, and the third dichroic azo pigment compound (if used as needed) can be arbitrarily set. However, the content ratio of the second dichroic azo pigment compound to the first dichroic azo pigment compound (second dichroic azo pigment compound / first dichroic azo pigment compound) is preferably 0.1 to 10 in molar terms, more preferably 0.2 to 5, and even more preferably 0.3 to 0.8. If the content ratio of the second dichroic azo pigment compound to the first dichroic azo pigment compound is within the above range, the orientation degree can be improved.

[0378] [Characteristics of the anisotropic light absorption layer]

[0379] The transmittance (hereinafter, unless otherwise specified, refers to the transmittance at a wavelength of 550 nm) of the light-absorbing anisotropic layer of the present invention, tilted at 30° from the transmittance center axis, is preferably 60% or less, more preferably 40% or less, and even more preferably 20% or less. This improves the contrast between the illuminance at the transmittance center and in directions deviating from the transmittance center, thereby sufficiently reducing the viewing angle.

[0380] In this invention, the transmittance of the central axis of the light-absorbing anisotropic layer is preferably 65% ​​or more, more preferably 75% or more, and even more preferably 85% or more. There is no particular upper limit, and less than 100% can be cited as an example. If the transmittance is within the above range, the illuminance at the viewing angle center of the image display device using the light-absorbing anisotropic layer can be improved, and visual recognition can be good.

[0381] In the liquid crystal display device of the present invention, in order to minimize the illuminance at the center of the field of view while minimizing the illuminance at the surrounding area, the orientation degree measured at a wavelength of 550 nm of the light-absorbing anisotropic layer is preferably 0.80 or more, more preferably 0.90 or more, and even more preferably 0.95 or more.

[0382] Furthermore, the degree of orientation measured at a wavelength of λnm is defined in this specification as follows.

[0383] When using an AxoScan OPMF-1 (manufactured by Opto Science, Inc.) for measurement, the Miller matrix at a wavelength of 550 nm was measured at each polar angle, changing the angle of the anisotropic absorption layer relative to the normal direction (i.e., the polar angle) from 0 to 90° in 5° increments, to derive the minimum transmittance (Tmin). Then, after removing the influence of surface reflection, Tmin at the highest polar angle was designated as Tm(0), and Tmin at the direction where the polar angle increases by 40° from the highest Tmin was designated as Tm(40). Based on the obtained Tm(0) and Tm(40), the absorbance was calculated using the following formula, and A(0) and A(40) were calculated.

[0384] A = -log(Tm)

[0385] Here, Tm represents transmittance and A represents absorbance.

[0386] The orientation degree S at a wavelength of 550 nm, as defined by the following formula, was calculated using A(0) and A(40).

[0387] S=(4.6×A(40)-A(0)) / (4.6×A(40)+2×A(0))

[0388] By changing the wavelength from 550nm to 420nm or 650nm, the orientation degree S at wavelengths of 420nm and 650nm is calculated.

[0389] The optical film using the light-absorbing anisotropic layer of the present invention has high transmittance along its central axis, and can reduce transmittance in directions deviating from the central axis. This is presumably due to the following reasons.

[0390] To reduce transmittance in directions deviating from the transmittance central axis, this can be achieved by increasing the thickness of the light-absorbing anisotropic layer, but this simultaneously reduces the transmittance along the transmittance central axis. Here, if the orientation degree measured at 550 nm is set to 0.95 or higher, it is assumed that the dichroic material primarily influences the orientation degree measured at 550 nm. Therefore, it is assumed that the absorption axis of the dichroic material deviates from the transmittance central axis, but with a decrease in frequency. Thus, absorption based on the dichroic material when observed from the transmittance central axis can be suppressed, and the result can be inferred to be an increase in transmittance along the transmittance central axis direction.

[0391] Furthermore, the preferred light-absorbing anisotropic layer simultaneously satisfies the following equations (1) and (2).

[0392] S P (420nm)<S P (550nm) Equation (1)

[0393] S P (420nm) P (650nm) Equation (2)

[0394] Here, the aforementioned S P (λ) represents the orientation degree of the light-absorbing anisotropic layer measured at a wavelength of λnm.

[0395] There is no particular limitation on the thickness of the light-absorbing anisotropic layer, but from the viewpoint of the flexibility of using the optical laminate of the present invention, described later, in a polarizing element, it is preferably 100 to 8000 nm, more preferably 300 to 5000 nm.

[0396] [Methods for forming anisotropic light absorption layers]

[0397] There is no particular limitation on the method for forming the light-absorbing anisotropic layer. A method that includes the following steps in sequence is as follows: a step of forming a coating film by coating the above-mentioned light-absorbing anisotropic layer forming composition (hereinafter also referred to as the "coating film forming step"); and a step of aligning the liquid crystal component or dichroic substance contained in the coating film (hereinafter also referred to as the "alignment step").

[0398] In addition, the liquid crystal component is as follows: it not only includes the liquid crystal compound mentioned above, but also, in the case that the dichroic substance mentioned above has liquid crystal properties, it includes a dichroic substance that has liquid crystal properties.

[0399] ​Furthermore, the technique for achieving the desired orientation of organic dichroic pigments can refer to the fabrication techniques for polarizers utilizing organic dichroic pigments or the fabrication techniques for guest-host liquid crystal cells. For example, the techniques used in the fabrication methods of dichroic polarizing elements described in Japanese Patent Application Publication No. 11-305036 or Japanese Patent Application Publication No. 2002-90526, and the fabrication methods of guest-host type liquid crystal display devices described in Japanese Patent Application Publication No. 2002-99388 or Japanese Patent Application Publication No. 2016-27387, can also be used in the fabrication of the light absorption anisotropic layer used in this invention.

[0400] For example, using guest-host type liquid crystal cell technology, the molecules of organic dichroic pigments can be oriented in the desired manner as described above, along with the orientation of the host liquid crystal. Specifically, the organic dichroic pigment, which will become the guest, is mixed with a rod-shaped liquid crystal compound, which becomes the host liquid crystal, so that the host liquid crystal is oriented, and the molecules of the organic dichroic pigment are oriented along with the orientation of the liquid crystal molecules, and this orientation state is fixed, thereby enabling the fabrication of the light-absorbing anisotropic layer used in this invention.

[0401] To prevent the light absorption characteristics of the anisotropic light absorption layer used in this invention from changing due to the usage environment, it is preferable to fix the orientation of the organic dichroic pigment by forming chemical bonds. For example, the orientation can be fixed by polymerizing the host liquid crystal, the organic dichroic pigment, or polymerizable components added as needed.

[0402] Furthermore, a guest-host type liquid crystal cell having a liquid crystal layer comprising at least an organic dichroic pigment and a host liquid crystal on a pair of substrates can be used itself as the light absorption anisotropic layer used in this invention. The orientation of the host liquid crystal (and the orientation of the accompanying organic dichroic pigment molecules) can be controlled by an alignment film formed on the inner surface of the substrate. As long as no external stimulus such as an electric field is applied, its orientation state can be maintained, thereby enabling the light absorption characteristics of the light absorption anisotropic layer used in this invention to remain constant.

[0403] Furthermore, by permeating an organic dichroic pigment into a polymer film, the organic dichroic pigment is oriented along with the orientation of the polymer molecules in the polymer film, thereby enabling the fabrication of a polymer film that meets the light absorption characteristics required by the anisotropic light absorption layer used in this invention. Specifically, the fabrication is performed by coating a solution of the organic dichroic pigment onto the surface of the polymer film and allowing it to permeate into the film. The orientation of the organic dichroic pigment 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. Detailed information about this method is described in Japanese Patent Application Publication No. 2002-90526.

[0404] The coating film formation process, orientation process, and other processes will be explained below.

[0405] (Coating film formation process)

[0406] The coating film forming process is a process of forming a coating film by coating a light-absorbing anisotropic layer composition.

[0407] By using a light-absorbing anisotropic layer forming composition containing the above-mentioned solvent, or by using a light-absorbing anisotropic layer forming composition that has been molten or made into a liquid by heating, etc., the light-absorbing anisotropic layer forming composition can be easily coated.

[0408] Coating methods for compositions used to form anisotropic light-absorbing layers include, for example, known methods such as roller coating, gravure printing, spin coating, wire-wound bar coating, extrusion coating, direct gravure coating, reverse gravure coating, die coating, spray coating, and inkjet coating.

[0409] (Orientation process)

[0410] The alignment process is a process that orients the liquid crystal components contained in the coated film. This yields a light-absorbing anisotropic layer. The alignment process can include drying, heating, and cooling processes. These processes will be described below.

[0411] The orientation process may include a drying process. This drying process removes components such as solvents from the coated film. The drying process can be performed by placing the coated film at room temperature for a specified time (e.g., natural drying), or by heating and / or air supply.

[0412] Here, the liquid crystal components contained in the composition for forming anisotropic light absorption layers are sometimes oriented through the above-described coating film forming process or drying process. For example, in the case where the composition for forming anisotropic light absorption layers is prepared as a coating liquid containing a solvent, the solvent can be removed from the coating film by drying the coating film, thereby obtaining a coating film with anisotropic light absorption (i.e., anisotropic light absorption film).

[0413] If the drying process is performed at a temperature above the transition temperature at which the liquid crystal components contained in the coated film transform into the liquid crystal phase, the heating process described later may not be necessary.

[0414] From the perspective of manufacturing applicability, the transition temperature of the liquid crystal component contained in the coating film to the liquid crystal phase is preferably 10 to 250°C, more preferably 25 to 190°C. If the transition temperature is 10°C or higher, cooling treatment to lower the temperature to the liquid crystal phase temperature range is not required, which is therefore preferable. Furthermore, if the transition temperature is 250°C or lower, high temperatures are not required when setting the isotropic liquid state to a temperature higher than the temporary liquid crystal phase temperature range, thereby reducing heat waste, substrate deformation, and deterioration, which is also preferable.

[0415] The alignment process preferably includes a heat treatment. This allows the liquid crystal components contained in the coated film to be aligned, thus enabling the heat-treated coated film to be preferably used as a light-absorbing anisotropic film.

[0416] From the perspective of manufacturing applicability, the heat treatment is preferably 10 to 250°C, more preferably 25 to 190°C. Furthermore, the heating time is preferably 1 to 300 seconds, more preferably 1 to 60 seconds.

[0417] The alignment process can include a cooling process performed after the heat treatment. The cooling process involves cooling the heated coating film to approximately room temperature (20–25°C). This helps to fix the alignment of the liquid crystal components contained in the coating film. There are no particular limitations on the cooling method; known methods can be used.

[0418] Through the above processes, an anisotropic light-absorbing film can be obtained.

[0419] Furthermore, in this method, drying treatment and heat treatment are cited as methods for aligning the liquid crystal components contained in the coating film, but it is not limited to these, and can be implemented by known alignment treatments.

[0420] (Other processes)

[0421] The method for forming the light-absorbing anisotropic layer may include a step (hereinafter also referred to as the "curing step") after the above-mentioned orientation step to cure the light-absorbing anisotropic layer.

[0422] For example, when the light-absorbing anisotropic layer has cross-linking groups (polymeric groups), the curing process is carried out by heating and / or light irradiation (exposure). The curing process is preferably carried out by light irradiation.

[0423] The light source used for curing can be various light sources such as infrared, visible light, or ultraviolet light, but ultraviolet light is preferred. Furthermore, during curing, ultraviolet light can be irradiated while heating is being performed, or ultraviolet light can be irradiated through a filter that transmits only a specific wavelength.

[0424] When exposure is performed while heating, although the heating temperature during exposure also depends on the transition temperature of the liquid crystal components contained in the liquid crystal film into the liquid crystal phase, it is preferably 25 to 140°C.

[0425] Furthermore, exposure can also be performed in a nitrogen environment. When curing liquid crystal films via free radical polymerization, the polymerization hindrance caused by oxygen is reduced, therefore exposure in a nitrogen environment is preferred.

[0426] There is no particular limitation on the thickness of the light-absorbing anisotropic layer, but from the viewpoint of the flexibility of using the laminate of the present invention described later in a polarization element, it is preferably 100 to 8000 nm, more preferably 300 to 5000 nm.

[0427] (Patterning of anisotropic light absorption layers)

[0428] Furthermore, the light absorption anisotropic layer of the present invention can be a light absorption anisotropic layer having regions A and B in the plane, and having different tilt transmittance (hereinafter referred to as 30° polar angle transmittance) when viewed from the polar angle of 30° between regions A and B. In this case, it is preferable to have a light absorption anisotropic layer with a 30° polar angle transmittance of region A of 10% or less and a 30° polar angle transmittance of region B of 80% or more.

[0429] In the areas described above, viewing angle dependence can be strengthened or weakened by patterning. This allows for the display of high-density information only in areas where viewing angle dependence is increased. Furthermore, as a display device, the ability to freely control viewing angle dependence enables the design of an aesthetically pleasing appearance. In display devices such as μLEDs, to prevent light leakage from the light-emitting portion to the surrounding areas, the contrast between light and dark areas in the image can be improved by patterning areas other than the light-emitting portion as areas with high transmittance at a 30° polar angle and the light-emitting portion as areas with low transmittance at a 30° polar angle.

[0430] -Pattern Formation Method-

[0431] Therefore, there are no particular limitations on the method for forming a patterned light absorption anisotropic layer with two or more different regions in the plane, and various known methods described in WO2019 / 176918 can be used. As examples, methods for controlling the thickness of the patterned light absorption anisotropic layer in the plane, methods for unevenly distributing dichroic pigment compounds in the patterned light absorption anisotropic layer, and methods for post-processing an optically uniform patterned light absorption anisotropic layer are also mentioned.

[0432] Methods for controlling the thickness of an in-plane patterned anisotropic light absorption layer include photolithography, imprinting, and forming the patterned anisotropic light absorption layer on a substrate with an uneven structure. Methods for unevenly distributing dichroic pigment compounds in the patterned anisotropic light absorption layer include extracting the dichroic pigment compounds by solvent impregnation (breaching). Furthermore, methods for post-processing an optically uniform patterned anisotropic light absorption layer include cutting a portion of the light absorption anisotropic layer flat using laser processing or similar methods.

[0433] [Tone Adjustment Layer]

[0434] The optical film of the present invention has a hue adjustment layer comprising at least one organic pigment compound.

[0435] The following is a detailed description of the optical film with excellent tone suppression across a wide range of colors obtained through the tone adjustment layer (the principle of tone adjustment), the organic pigment compounds contained in the tone adjustment layer, and the properties of the tone adjustment layer.

[0436] (The principle of color tone adjustment)

[0437] The hue control of optical films containing dichroic substances is usually achieved by adjusting the amount and / or ratio of dichroic substances added to the film. However, when the degree of orientation calculated by wavelength changes, it is difficult to obtain an optical film with excellent wide-range tone suppression simply by adjusting the amount and / or ratio of dichroic substances added.

[0438] For example, when using a dichroic substance having the above-mentioned thienothiazole skeleton, it sometimes has different absorption wavelengths relative to multiple directions, which can cause a decrease in the degree of orientation measured at wavelengths outside the main absorption wavelength range of the dichroic substance.

[0439] Specifically, for example, when a dichroic pigment compound with a thienothiazole skeleton is used in a light-absorbing anisotropic layer, the degree of orientation measured in the short wavelength region is reduced. When the degree of orientation measured at each wavelength is set as S(λ), the relationship between the above equations (1) and (2) is easily satisfied.

[0440] When the relationship between equations (1) and (2) is satisfied, S P (420nm) is less than S P (550nm) and S P(650nm), therefore, from the appearance, only the orientation degree in the short wavelength region becomes low. At this time, for example, even if multiple dichroic materials are combined and the hue is neutralized when viewed from the transmittance central axis direction, the hue is difficult to neutralize when viewed from the tilt direction. That is, when the relationship of equations (1) and (2) is satisfied, it is difficult to obtain an optical film with excellent wide-range tone suppression by simply adjusting the amount and / or the ratio of dichroic materials added to the optical film.

[0441] Furthermore, when an optical film contains multiple dichroic substances, even if the orientation ease of each dichroic substance in the optical film is different, the orientation degree calculated by measuring the wavelength of orientation degree may sometimes change. It is difficult to obtain an optical film with excellent wide-range modulation suppression by simply adjusting the amount and / or ratio of dichroic substances added to the optical film.

[0442] In this invention, when the hue along the transmittance central axis is made neutral by adjusting the amount and / or ratio of dichroic material added to the light absorption anisotropy layer, the hue variation when viewed from the tilted direction of the transmittance central axis may increase. Here, it is believed that by adjusting the amount and / or ratio of dichroic material added while using a hue adjustment layer that satisfies any one of conditions 1 to 3 below, the hue variation when viewed from both the transmittance central axis and tilted directions can be easily suppressed; that is, an optical film with further improved hue suppression across a wide range of angles can be obtained.

[0443] At this point, it is assumed that the hue adjustment layer satisfies any one of the following conditions 1 to 3, and that the hue adjustment layer has small hue changes when viewed from the transmissivity central axis direction and the tilt direction, and cancels the hue changes of the light absorption anisotropic layer. As a result, an optical film with further good hue modulation suppression can be obtained.

[0444] Requirement 1: S C (420nm) < 0.1

[0445] Requirement 2: S C (550nm) < 0.1

[0446] Requirement 3: S C (650nm) < 0.1

[0447] Among them, S C (λnm) represents the orientation degree of the tone adjustment layer as measured at a wavelength of λnm.

[0448] (The organic pigment compounds contained in the tone adjustment layer)

[0449] The hue adjustment layer contains at least one organic pigment compound.

[0450] Examples of structures that can be found in the pigment compounds included in the hue adjustment layer include azo, methine, anthraquinone, triarylmethane, oxazine, azomethyl, phthalocyanine, porphyrin, perylene, pyrrolopyrrole, and squaric acid cyanine structures. From the viewpoint of excellent absorption waveform, heat resistance, and lightfastness, compounds with methine, azomethyl, azo, phthalocyanine, and anthraquinone structures are preferred, compounds with azo, phthalocyanine, and anthraquinone structures are more preferred, and compounds with anthraquinone structures are even more preferred.

[0451] Specific examples of compounds having the above-mentioned structure include, for instance, the pigment compounds described in the book *Functional Pigments*, co-authored by Nobuoshi Okawahara, Ken Matsuoka, Tsuneaki Hirashima, and Teijiro Kitao, published by Kodansha Ltd., edited by Sumio Tokita in 1992, and *Materials Related to Electronic Processing*, published by CMC Publishing Co., Ltd. in 1998.

[0452] Furthermore, it is preferred that the pigment compound contained in the hue adjustment layer has at least one structure of benzene ring and heterocycle in its molecule.

[0453] As a structure containing a benzene ring, it is sufficient to include a benzene ring in a part of the structure. Examples of structures containing a benzene ring include benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, fluorene rings, pyrene rings, as well as anthraquinone structures, oxazine structures, phthalocyanine structures, porphyrin structures, and perylene structures.

[0454] Examples of heterocyclic structures include cyclic structures containing heteroatoms other than carbon. Heterocyclic structures may or may not be aromatic, but are preferably aromatic. Examples of heterocyclic structures include pyrrole rings, furan rings, thiophene rings, imidazole rings, pyrazole rings, oxazole rings, benzimidazole rings, indole rings, purine rings, and benzotriazole rings, as well as oxazine structures, phthalocyanine structures, and porphyrin structures.

[0455] The absorption peak wavelength of the pigment compound contained in the hue adjustment layer used in this invention is preferably 500–650 nm, more preferably 550–600 nm. By setting the absorption peak wavelength of the pigment compound within this range, the hue of the optical film in this invention can be further adjusted to neutral.

[0456] In this specification, the absorption peak wavelength of the pigment compound refers to the maximum absorption wavelength in the absorption spectrum determined by the following methods.

[0457] Prepare a solution by dissolving 1.0 mg of the pigment compound to be tested in 100 ml of chloroform or 100 ml of water.

[0458] Next, the prepared solution was added to a quartz cuvette (1 cm rectangular cuvette), and the absorbance of the solution in the wavelength range of 200–800 nm was measured using a U-3150 ultraviolet-visible-infrared spectrophotometer (manufactured by Shimadzu Corporation).

[0459] Next, the wavelength of maximum absorption is determined from the obtained absorption spectrum.

[0460] The following are specific examples of pigment compounds used in this invention, but the invention is not limited thereto.

[0461] -Compounds with anthraquinone structure-

[0462] [Chemical Formula 26]

[0463]

[0464] -Compounds with an azo structure-

[0465] [Chemical Formula 27]

[0466]

[0467] -Compounds with a triarylmethane structure-

[0468] [Chemical Formula 28]

[0469]

[0470] -Compounds with oxazine structures-

[0471] [Chemical Formula 29]

[0472]

[0473] -Compounds with phthalocyanine structure-

[0474] [Chemical Formula 30]

[0475]

[0476] (Properties of the color adjustment layer)

[0477] Furthermore, the tone adjustment layer preferably satisfies any one of the following requirements 1 to 3, more preferably satisfies two of the following requirements 1 to 3, and even more preferably satisfies all of the following requirements 1 to 3.

[0478] Requirement 1: S C (420nm) < 0.1

[0479] Requirement 2: S C (550nm) < 0.1

[0480] Requirement 3: S C (650nm) < 0.1

[0481] In addition, S C (λnm) represents the orientation degree of the tone adjustment layer measured at a wavelength of λnm. The orientation degree measured at a wavelength of λnm can be obtained by the same method as the method for measuring the orientation degree of the light absorption anisotropic layer described above, when the object of the measurement is set as a tone adjustment layer.

[0482] When an optical film is obtained by laminating a tone adjustment layer, the tone adjustment layer before transfer lamination can be used for measurement, or the tone adjustment layer can be formed on another substrate for measurement, or the tone adjustment layer can be separated from the laminated optical film for measurement. In this specification, the orientation degree of the material from which the tone adjustment layer has been separated from the laminated optical film is described as the object under test.

[0483] The color adjustment layer satisfies any one of the above requirements 1 to 3, but also satisfies all of requirements 1 to 3, or can satisfy two of the requirements selected from requirements 1 to 3.

[0484] Furthermore, it is preferable to appropriately select the aforementioned requirements for the tone adjustment layer by means of the orientation degree of the dichroic material contained in the light absorption anisotropic layer. Hereinafter, the relationship of the orientation degree of the light absorption anisotropic layer and the combination of preferred requirements satisfied by the tone adjustment layer under the relationship of the orientation degree are shown.

[0485] For example, the following "Combination 1: S P (420nm)<S P (650nm): Requirement 3" refers to the fact that the light-absorbing anisotropic layer contains the aforementioned first dichroic azo dye compound and the aforementioned third dichroic azo dye compound, in the aforementioned S P (420nm) is smaller than the above S P In the case of (650nm), the tone adjustment layer preferably satisfies requirement 3.

[0486] Combination 1: S P (420nm)<S P (650nm): Requirement 3

[0487] Combination 2: S P (420nm)<S P (550nm): Requirement 2

[0488] Combination 3: S P (550nm)<S P (420nm): Requirement 1

[0489] Combination 4: SP (550nm)<S P (650nm): Requirement 3

[0490] Combination 5: S P (650nm)<S P (420nm): Requirement 1

[0491] Combination 6: S P (650nm)<S P (550nm): Requirement 2

[0492] Among the above combinations, combinations 1, 2, 5 or 6 are preferred, and combinations 1 or 5 are more preferred.

[0493] Furthermore, the hue adjustment layer preferably satisfies the following formula (7).

[0494] 0.005≤(c(C)×d(C)) / (c(P)×d(P))≤0.06 (Equation 7)

[0495] In equation (7), c(C) represents the mass ratio of the organic pigment compound in the tone adjustment layer relative to the total mass of the tone adjustment layer.

[0496] In equation (7), d(C) represents the film thickness (μm) of the tone adjustment layer.

[0497] In equation (7), c(P) represents the mass ratio of the dichroic pigment compound in the light-absorbing anisotropic layer relative to the total mass of the light-absorbing anisotropic layer.

[0498] In equation (7), d(P) represents the film thickness (μm) of the light-absorbing anisotropic layer.

[0499] In the above formula (7), the lower limit is more preferably 0.01 or more, and the upper limit is more preferably 0.03 or less. If the hue adjustment layer satisfies formula (7), the hue when viewed from the center axis of transmittance can be neutral, and the transmittance in the center axis direction can be improved.

[0500] Furthermore, in this specification, the thickness of the optical film can be determined by observing and measuring the length of the cross-section of the optical film obtained by cutting it using a slicing machine, and by using a scanning electron microscope (SEM).

[0501] A tone adjustment layer can function as a tone adjustment layer on its own, or it can be combined with other layers. That is, anisotropic light absorption layers, transparent substrate films, alignment films, and barrier layers can all function as tone adjustment layers.

[0502] When the tone adjustment layer of the optical film is a different layer from the light absorption anisotropic layer, there is no particular restriction on the stacking position of the tone adjustment layer in the optical film, but it is preferable to have it in direct contact with the light absorption anisotropic layer and to place it on the visual recognition side, which is closer to the light absorption anisotropic layer than the light absorption anisotropic layer.

[0503] [Transparent Substrate Film]

[0504] There are no particular limitations on the transparent substrate film. For example, known transparent resin films, known transparent resin sheets, and known transparent resin films can be cited.

[0505] Examples of transparent resin films include, for example, cellulose acylated films (e.g., cellulose triacetate film (refractive index 1.48), cellulose diacetate film, cellulose acetate butyrate film, cellulose acetate propionate film), polyethylene terephthalate film, polyethersulfone film, polyacrylic resin film, polyurethane resin film, polyester film, polycarbonate film, polysulfone film, polyether film, polymethylpentene film, polyetherketone film, and (meth)acrylonitrile film, etc.

[0506] From the viewpoints of high transparency, low optical birefringence, and ease of manufacture, cellulose acylated films, which are commonly used as protective films for polarizers, are preferred, and cellulose triacetate films are more preferred.

[0507] The thickness of transparent substrate films is typically 20μm to 100μm.

[0508] [Orientation film]

[0509] The optical film of the present invention may have an alignment film between the transparent substrate film and the light-absorbing anisotropic layer.

[0510] Regarding orientation films, there are no particular limitations as long as the dichroic pigment compound can be oriented in the desired state on the orientation film. Examples include films formed from polyfunctional acrylate compounds and polyvinyl alcohol films, with polyvinyl alcohol films being preferred. The polyvinyl alcohol used for polyvinyl alcohol films is preferably modified polyvinyl alcohol.

[0511] [Blocking Layer]

[0512] The optical laminate of the present invention can have a light-absorbing anisotropic layer while also having a blocking layer.

[0513] Here, the barrier layer is also referred to as the gas barrier layer (oxygen barrier layer), which has the function of protecting the polarization element of the present invention from the influence of gases such as oxygen in the atmosphere, moisture, or compounds contained in adjacent layers.

[0514] Regarding the barrier layer, for example, reference can be made to paragraphs

[0014] to

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

[0042] to

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

[0045] to

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

[0010] to

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

[0021] to

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

[0515] [Refractive index adjustment layer]

[0516] In the optical laminate of the present invention, the aforementioned light-absorbing anisotropic layer has a dichroic material, and internal reflection caused by the high refractive index of the light-absorbing anisotropic layer can sometimes become a problem. In this case, a refractive index adjustment layer is preferably present. The refractive index adjustment layer is a layer disposed in contact with the light-absorbing anisotropic layer, and preferably has an in-plane average refractive index of 1.55 or higher and 1.70 or lower at a wavelength of 550 nm. The refractive index adjustment layer is preferably a refractive index adjustment layer used for so-called refractive index matching.

[0517] [Properties of optical films]

[0518] The transmittance of the optical film of the present invention, in the direction of the central axis, is preferably 65% ​​or more, more preferably 75% or more, and even more preferably 85% or more. There is no particular limitation on the upper limit; examples of less than 100% are possible.

[0519] The thickness of the optical film of the present invention is preferably 30-90 μm, more preferably 35-70 μm, and even more preferably 40-50 μm.

[0520] <Methods for manufacturing optical films>

[0521] The optical film of the present invention can be manufactured using known methods, and there are no particular limitations. Similarly, known methods can also be used for each step in the manufacturing process, and there are no particular limitations.

[0522] As an example of the method for manufacturing the optical film of the present invention, a method comprising the following steps in sequence is given: a step of coating an alignment film forming composition onto the above-mentioned transparent substrate film to form an alignment film; a step of coating the above-mentioned light absorption anisotropic layer forming composition onto the alignment film and aligning the dichroic pigment compound contained in the above-mentioned coating film to obtain the above-mentioned light absorption anisotropic layer; and a step of forming the above-mentioned tone adjustment layer in a manner adjacent to the above-mentioned light absorption anisotropic layer.

[0523] The following describes the layers that can be incorporated into the manufacture of optical films. Specifically, adhesive layers and bonding layers will be described.

[0524] [Adhesive layer]

[0525] An adhesive layer can be incorporated into the manufacture of optical films.

[0526] The adhesive layer in this invention is preferably a transparent and optically isotropic adhesive, the same as that used in conventional liquid crystal display devices, and pressure-sensitive adhesives are typically used.

[0527] In addition to the base material (adhesive), conductive particles, and thermally expandable particles used as needed, the adhesive layer of this invention may also contain additives such as crosslinking agents (e.g., isocyanate-based crosslinking agents, epoxy-based crosslinking agents, etc.), tackifiers (e.g., rosin derivative resins, polyterpene resins, petroleum resins, oil-soluble phenolic resins, etc.), plasticizers, fillers, anti-aging agents, surfactants, ultraviolet absorbers, light stabilizers, and antioxidants.

[0528] The thickness of the adhesive layer is typically 20–500 μm, preferably 20–250 μm. If it is less than 20 μm, the required adhesive strength and / or reprocessing suitability may not be achieved; if it exceeds 500 μm, the adhesive may protrude or seep out from the periphery of the image display device.

[0529] The adhesive layer can be formed by appropriate methods, such as directly applying a coating liquid containing a base material, conductive particles, and thermally expandable particles, additives, solvents, etc., to the support 110 for the protective component and then pressing it through a release liner; or applying a coating liquid to a suitable release liner (release paper, etc.) to form a thermally expandable adhesive layer and then pressing and transferring it onto the support 110 for the protective component.

[0530] Furthermore, as a protective component, a structure in which conductive particles can be added can be applied to the structure of the heat-peelable adhesive sheet described in Japanese Patent Application Publication No. 2003-292916, for example.

[0531] Furthermore, as a protective component, it can also be used on the surface of the adhesive layer of commercially available products such as NITTO DENKO CORPORATION's "REVALPHA" to disperse conductive particles.

[0532] There are no particular restrictions on the method for forming the adhesive layer. Detailed information will be provided in the later section on adhesive layer formation.

[0533] [Adhesive layer]

[0534] In the manufacture of optical films, an adhesive layer can be incorporated. The adhesive layer is a layer formed by an adhesive. The adhesive exhibits its adhesive properties through drying or reaction after bonding.

[0535] Polyvinyl alcohol (PVA) adhesives are an example of adhesives that exhibit adhesion through drying.

[0536] Examples of curing adhesives that exhibit adhesion through reaction include reactive energy-curing adhesives such as (meth)acrylate adhesives and cationic polymerization-curing adhesives. Furthermore, (meth)acrylates refer to acrylates and / or methacrylates.

[0537] Examples of curing components in (meth)acrylate adhesives include compounds having (meth)acryloyl groups and compounds having vinyl groups.

[0538] Furthermore, compounds having epoxy groups and / or oxobutyl groups can also be used as cationic polymerization curing adhesives. There are no particular limitations on the epoxy group composition, provided that the compound has at least two epoxy groups within the molecule; various commonly known curable epoxy compounds can be used. Examples of preferred epoxy compounds include compounds having at least two epoxy groups and at least one aromatic ring within the molecule (aromatic epoxy compounds), and compounds having at least two epoxy groups within the molecule, with at least one of them formed between two adjacent carbon atoms constituting an alicyclic ring (alicyclic epoxy compounds).

[0539] From the perspective of resistance to heat deformation, UV-curing adhesives that are cured by UV irradiation are preferred.

[0540] [Formation Method]

[0541] The method for forming the adhesive layer and / or bonding layer is described.

[0542] The adhesive layer and / or each layer of the bonding layer may contain compounds with ultraviolet absorption energy, such as salicylate compounds, phenolic compounds, benzotriazole compounds, cyanoacrylate compounds, and nickel complex salt compounds. Furthermore, the adhesive layer and / or bonding layer can be treated by irradiating them with ultraviolet light.

[0543] It is possible to attach adhesive layers and / or bonding layers to optical films using appropriate methods. For example, an adhesive solution of approximately 10 to 40% by mass can be prepared by dispersing or dissolving the base polymer or polymer composition of the adhesive layer or bonding layer in a solvent containing suitable solvents such as toluene and ethyl acetate. Examples include methods of directly attaching the prepared solution to a film using appropriate spreading methods such as casting and coating, and methods of forming and transferring adhesive layers or bonding layers on a substrate other than an optical film.

[0544] It is possible to stack layers of different compositions and types to form adhesive layers and / or bonding layers.

[0545] Furthermore, the adhesive layer and / or bonding layer can be disposed on one side or both sides of the optical film. When the adhesive layer and / or bonding layer are disposed on both sides of the optical film, the composition, type, and thickness of the adhesive layer and / or bonding layer can be different on both sides of the film.

[0546] Furthermore, the optical film can have a protective film, which can undergo surface modification treatment before the application of adhesives or binders to improve adhesion. Specific surface modification treatments include, for example, corona treatment, plasma treatment, primer treatment, and saponification treatment.

[0547] <Optical laminate>

[0548] The optical laminate of the present invention is an optical laminate consisting of an optical film of the present invention with an angle θ between the transmittance central axis and the film normal of 0° to 45°, and a polarizer layer in which a dichroic material is horizontally oriented relative to the film surface. This reduces the transmittance of light in the direction tilted relative to the transmittance central axis, and by narrowing the field of view, it can be used in applications such as privacy films.

[0549] There are no particular limitations on the polarizer layer used to horizontally align the dichroic material. The polarizer layer can be a polarizer that aligns the dichroic material horizontally by dyeing it with polyvinyl alcohol or other polymer resins and stretching it, or it can be a polarizer that utilizes the orientation of the liquid crystal compound to horizontally align the dichroic material, as in the light-absorbing anisotropic layer of the present invention. Preferably, a polarizer that utilizes the orientation of the liquid crystal compound to horizontally align the dichroic material is preferred.

[0550] Polarizers that align dichroic materials by utilizing the orientation properties of liquid crystals have several advantages, including: a thickness of approximately 0.1 to 5 μm, allowing for very thin layers; minimal cracking or thermal deformation during bending, as described in Japanese Patent Application Publication No. 2019-194685; and excellent durability even for polarizers with high transmittance exceeding 50%, as described in Japanese Patent Application Publication No. 6483486.

[0551] Taking advantage of these advantages, the optical laminate of the present invention is suitable for applications requiring high brightness and / or small and lightweight, for precision optical systems, for molding to curved parts, and for flexible applications.

[0552] From the viewpoint of being suitable for molding curved parts and for flexible applications, the film thickness of the optical laminate of the present invention is preferably 40 to 150 μm, more preferably 45 to 100 μm, and even more preferably 50 to 70 μm.

[0553] [Optical laminates with textured surfaces]

[0554] From the viewpoint of suppressing adhesion caused by the contact between smooth surfaces, it is preferable to impart an arithmetic surface roughness Ra of 35 to 125 nm to the optical laminate of the present invention.

[0555] The arithmetic surface roughness Ra of the uneven surface is more preferably 50-110 nm, and even more preferably 65-95 nm. By setting the arithmetic surface roughness Ra to 35 nm or more, adhesion between the films can be prevented when overlapping optical films, and adhesion marks are less likely to remain. Furthermore, by setting the arithmetic surface roughness Ra to 125 nm or less, a narrower field of view can be maintained, particularly in applications involving privacy films.

[0556] Furthermore, the arithmetic mean roughness Ra refers to the arithmetic mean roughness conforming to JIS B0601:2001. The arithmetic mean roughness Ra can be measured using a stylus-type surface roughness meter (e.g., the Mitutoyo Corporation SJ-401 surface roughness measuring machine). This specification describes the arithmetic surface roughness Ra measured using a stylus-type surface roughness meter (the Mitutoyo Corporation SJ-401 surface roughness measuring machine).

[0557] As a method for imparting the aforementioned surface roughness, it can be bonded to other optical films with surface irregularities, or a surface irregularity layer can be further laminated, or the irregularity can be directly imparted to the barrier layer or the like on the outermost surface of the optical laminate of the present invention. For example, as other optical films with surface irregularities, examples include (A) styrene-methyl methacrylate copolymer resin particles with an average particle size of 1.0 to 3.0 μm and a refractive index of 1.50 to 1.54 as described in Japanese Patent No. 5909454, (B) a curable compound having two or more curable groups in the molecule, (C) a montmorillonite-type clay organic composite formed by inserting a quaternary ammonium salt represented by the following general formula (1R) into montmorillonite-type clay, and (D) an anti-glare film formed from a compound containing a volatile organic solvent.

[0558] General formula (1R)[(R) 1 )3(R 2 )N] + ·X - (1R)

[0559] (where R is in the formula) 1 and R 2 They are not the same, R 1R represents an alkyl, alkenyl, or ynyl group with 4 to 24 carbon atoms. 2 X represents an alkyl, alkenyl, or ynyl group having 1 to 10 carbon atoms. - (representing anion)

[0560] Other optical films with the above-mentioned surface irregularities can be bonded using an adhesive, or the surface irregularity layer described in Japanese Patent No. 5909454 can be applied to the outermost layer of the optical film of the present invention.

[0561] Furthermore, as an optical film with other surface irregularities, an example can be the thin film described in Japanese Patent No. 6093153, which is formed from a cured product of a polymer, a curable resin precursor, and a curable composition and includes a surface irregularity layer with a phase-separated structure. The polymer is composed of a (meth)acrylic resin having polymerizable groups and a fiber derivative, and the cured product of the curable composition includes a fluorinated leveling agent composed of a resin having free radical polymerizable groups and branched fluoroaliphatic hydrocarbon groups. An adhesive can be used to bond the aforementioned optical film, or the surface irregularity layer with a phase-separated structure can be further coated onto the optical film of the present invention.

[0562] In the aforementioned surface-uneven film, low internal scattering is preferred, and internal haze is preferably 5% or less, more preferably 3% or less, and even more preferably 1% or less. By setting the internal haze to 5% or less, a narrower field of view can be maintained, particularly in applications involving privacy films.

[0563] <Image display device>

[0564] The image display device of the present invention has the optical film of the present invention described above or the optical laminate of the present invention described above.

[0565] There is no particular limitation on the display element used in the image display device of the present invention. For example, liquid crystal cells, organic electroluminescent (hereinafter referred to as "EL") display panels and plasma display panels can be cited.

[0566] Among these, liquid crystal cells or organic EL display panels are preferred, and liquid crystal cells are more preferred. That is, as the image display device of the present invention, a liquid crystal display device that uses a liquid crystal cell as a display element, an organic EL display device that uses an organic EL display panel as a display element, and a liquid crystal display device are more preferred.

[0567] Liquid crystal display device

[0568] As an example of the image display device of the present invention, a liquid crystal display device preferably has the optical film and liquid crystal cell described above. A liquid crystal display device having the optical laminate (excluding the λ / 4 plate) and liquid crystal cell described above is even more preferred.

[0569] Furthermore, in this invention, it is preferable to use the optical laminate of this invention as the front polarizing element among the polarizing elements disposed on both sides of the liquid crystal cell, and more preferably, the optical laminate of this invention is used as both the front and rear polarizing elements.

[0570] The liquid crystal unit that constitutes a liquid crystal display device will be described in detail below.

[0571] (Liquid Crystal Unit)

[0572] The liquid crystal cells used in the liquid crystal display device 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.

[0573] In TN mode liquid crystal cells, bar-shaped liquid crystal molecules are substantially horizontally aligned when no voltage is applied, and then twisted at 60–120°. TN mode liquid crystal cells are most commonly used in color TFT (Thin Film Transistor) liquid crystal display devices and are documented in many publications.

[0574] In a VA-mode liquid crystal cell, the rod-shaped liquid crystal molecules are substantially vertically oriented when no voltage is applied. In addition to (1) a narrow VA-mode liquid crystal cell in which the rod-shaped liquid crystal molecules are substantially vertically oriented when no voltage is applied and substantially horizontally oriented when a voltage is applied (as described in Japanese Patent Application Publication No. 2-176625), the VA-mode liquid crystal cell also includes: (2) a liquid crystal cell in which the VA mode is multi-domained (MVA mode) to expand the viewing angle (as described in SID97, Digest oftech.Papers 28 (1997) 845), (3) a liquid crystal cell in which the rod-shaped liquid crystal molecules are substantially vertically oriented when no voltage is applied and twisted and multi-domain oriented when a voltage is applied (n-ASM mode) (as described in the proceedings of the Japan Liquid Crystal Conference 58-59 (1998)), and (4) a SURVIVAL mode liquid crystal cell (published in LCD International 98). Furthermore, the liquid crystal cell in VA mode can be any of PVA (Patterned Vertical Alignment), Optical Alignment, or PSA (Polymer-Sustained Alignment). Detailed information about these modes can be found in Japanese Patent Application Publication Nos. 2006-215326 and 2008-538819.

[0575] In IPS-mode liquid crystal cells, rod-shaped liquid crystal molecules are substantially parallel to the substrate. By applying an electric field parallel to the substrate surface, the liquid crystal molecules exhibit planar response. In IPS mode, the display becomes black when no electric field is applied, and the absorption axes of the upper and lower polarizers are orthogonal. Methods for improving the field of view by using optical compensation sheets to reduce light leakage during black display in the tilt direction are disclosed in Japanese Patent Application Publications Nos. 10-54982, 11-202323, 9-292522, 11-133408, 11-305217, and 10-307291.

[0576] [Organic EL Display Device]

[0577] As an example of the image display device of the present invention, namely an organic EL display device, a preferred embodiment may be a device having, for example, the polarizer, λ / 4 plate, and organic EL display panel of the present invention in sequence from the visual recognition side.

[0578] More preferably, the optical laminate of the present invention, having a λ / 4 plate, and the organic FL display panel are arranged sequentially from the visual recognition side. In this case, the optical laminate includes, from the visual recognition side, a substrate, an alignment film, the polarizer of the present invention, a blocking layer provided as needed, and a λ / 4 plate.

[0579] Furthermore, the organic FL display panel is a display panel constructed using organic FL elements formed by sandwiching an organic light-emitting layer (organic electroluminescent layer) between electrodes (between the cathode and the anode). There are no particular limitations on the structure of the organic FL display panel; known structures can be used.

[0580] [Curved surface image display device]

[0581] Examples of curved image display devices of the present invention are disclosed in Japanese Patent Application Publication Nos. 2017-181821, 2017-181819, 2017-102456 and 2014-95901.

[0582] [Example]

[0583] The present invention will now be specifically described based on embodiments. The materials, reagents, quantities, proportions, and operations shown in the following embodiments may be appropriately modified without departing from the spirit of the invention. Therefore, the present invention is not limited to the following embodiments.

[0584] <Example 1>

[0585] [Formation of Orientation Film]

[0586] The surface of a cellulose acylated film (40 μm thick TAC substrate; TG40 FUJIFILM Corporation) was saponified in an alkaline solution, and the following composition 1 for forming an alignment film was coated onto it using a winding bar. The support with the coating was dried with warm air at 60°C for 60 seconds, and then dried with warm air at 100°C for 120 seconds to form an alignment film AL1, thereby obtaining a TAC film 1 with an alignment film. The thickness of the alignment film AL1 is 1 μm.

[0587]

[0588]

[0589] Modified polyvinyl alcohol PVA-1

[0590] [Chemical Formula 31]

[0591]

[0592] [Formation of the light-absorbing anisotropic layer P1]

[0593] On the obtained TAC thin film 1 with an oriented film, the following light-absorbing anisotropic layer forming composition P1 is continuously coated by a winding bar, and after heating at 120°C for 60 seconds, it is cooled to room temperature (23°C).

[0594] Next, heat at 80°C for 60 seconds and then cool to room temperature again.

[0595] Then, using an LED light (center wavelength 365nm) at an illuminance of 200mW / cm² 2 Irradiate for 2 seconds under the irradiation conditions, thereby creating a light-absorbing anisotropic layer P1 on the alignment film AL1.

[0596] The thickness of the light-absorbing anisotropic layer P1 is 3.5 μm.

[0597]

[0598]

[0599] Dichroic substance D-1

[0600] [Chemical Formula 32]

[0601]

[0602] Dichroic substance D-2

[0603] [Chemical Formula 33]

[0604]

[0605] Dichroic substance D-3

[0606] [Chemical Formula 34]

[0607]

[0608] P-1, a polymeric liquid crystal compound

[0609] [Chemical Formula 35]

[0610]

[0611] Compound E-1

[0612] [Chemical Formula 36]

[0613]

[0614] Compound E-2

[0615] [Chemical Formula 37]

[0616]

[0617] Surfactant F-1

[0618] [Chemical Formula 38]

[0619]

[0620] [The formation of the hue adjustment layer C1]

[0621] A coating film is formed by continuously coating the following color-adjusting layer forming composition C1 onto the obtained light-absorbing anisotropic layer P1 using a wire rod.

[0622] Next, the support with the coating is dried in warm air at 60°C for 60 seconds, and then dried in warm air at 100°C for 120 seconds to form a tone adjustment layer C1, which is then designated as optical film 1. The thickness of the tone adjustment layer is 0.5 μm.

[0623]

[0624] Pigment compound G-1

[0625] [Chemical Formula 39]

[0626]

[0627] [Fabrication of optical laminate A1]

[0628] A polarizer 1 with a thickness of 8 μm and one side of the polarizer exposed was fabricated using the same method as that described in International Publication No. 2015 / 166991 for a polarizer 02 with a single-sided protective film.

[0629] The polarizer exposed surface of the polarizer 1 and the surface of the light absorption anisotropic layer of the optical film 1 are subjected to corona treatment and then bonded together using the PVA adhesive 1 described below, thereby fabricating an optical laminate A1.

[0630] (Preparation of PVA adhesive 1)

[0631] To prepare an aqueous solution with a solid content of 3.7%, 20 parts of hydroxymethyl melamine were dissolved in pure water at a temperature of 30°C, relative to 100 parts of polyvinyl alcohol resin containing acetylacetyl groups (average degree of polymerization: 1200, degree of saponification: 98.5 mol%, degree of acetylacetylation: 5 mol%).

[0632] [The creation of image display device I1]

[0633] An iPad Air (registered trademark) Wi-Fi model 16GB (manufactured by Apple Inc.), an IPS-type liquid crystal display device, was disassembled, and the liquid crystal cell was removed. The visual recognition side polarizer was peeled off from the liquid crystal cell, and the optical laminate A1 fabricated above was bonded to the surface where the visual recognition side polarizer was peeled off using adhesive sheet 1, so that the polarizer 1 side became the liquid crystal cell side. At this time, the direction of the absorption axis of the bonded polarizer 1 was the same as the absorption axis of the visual recognition side polarizer bonded to the product. After bonding, it was reassembled to manufacture the image display device I1.

[0634] (Making of Adhesive Sheet 1)

[0635] An acrylate polymer was prepared by following these steps.

[0636] In a reaction vessel equipped with a cooling pipe, a nitrogen inlet pipe, a thermometer, and a stirring device, 95 parts by mass of butyl acrylate and 5 parts by mass of acrylic acid were mixed and polymerized by solution polymerization to obtain an acrylate polymer PL1 with an average molecular weight of 2 million and a molecular weight distribution (Mw / Mn) of 3.0.

[0637] Next, in addition to the obtained acrylate polymer PL1 (100 parts by mass), CORONATE L (a 75% by mass ethyl acetate solution of toluene diisocyanate trimethylolpropane admixture, 3 isocyanate groups per molecule, manufactured by Nippon Polyurethane Industry Co., Ltd.) (1.0 parts by mass) and silane coupling agent KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.) (0.2 parts by mass) were mixed. Finally, ethyl acetate was added to a total solids concentration of 10% by mass, thereby preparing an adhesive forming composition. The composition was coated onto a release film that had been surface-treated with a silicone-based release agent using a die coater and dried at 90°C for 1 minute to obtain an acrylate adhesive sheet. The adhesive sheet had a film thickness of 25 μm and a storage modulus of 0.1 MPa.

[0638] <Example 2>

[0639] In the optical film 1 of Example 1, the composition C1 for forming the tone adjustment layer was changed to the composition C2 for forming the tone adjustment layer. Otherwise, the optical film 2 of Example 2 was produced in the same manner as in Example 1.

[0640]

[0641] Pigment compound G-2

[0642] [Chemical Formula 40]

[0643]

[0644] <Example 3>

[0645] In the light absorption anisotropic layer forming composition P1 of Example 1, the light absorption anisotropic layer forming composition P2, which changed the dichroic material D-3 to the dichroic material D-4, was used. Otherwise, the optical film 3 was made in the same manner as in Example 1.

[0646] Pigment compound D-4

[0647] [Chemical Formula 41]

[0648]

[0649] <Example 4>

[0650] Instead of the light absorption anisotropic layer forming composition P1 of Example 1, the light absorption anisotropic layer forming composition P3 was used. Otherwise, the optical film 4 was fabricated in the same manner as in Example 1.

[0651]

[0652] Dichroic substance D-5

[0653] [Chemical Formula 42]

[0654]

[0655] Liquid crystal compound L-1

[0656] [Chemical Formula 43]

[0657]

[0658] Liquid crystal compound L-2

[0659] [Chemical Formula 44]

[0660]

[0661] <Example 5>

[0662] In the optical film 1 of Example 1, the composition C1 for forming the tone adjustment layer was changed to the composition C3 for forming the tone adjustment layer. Otherwise, the optical film 5 was made in the same manner as in Example 1.

[0663]

[0664] Pigment compound G-3

[0665] [Chemical Formula 45]

[0666]

[0667] <Comparative Example 1>

[0668] In the optical film 1 of Example 1, no hue adjustment layer was provided. Otherwise, the optical film 6 was fabricated in the same manner as in Example 1.

[0669] <Comparative Example 2>

[0670] In the optical film 6 of Comparative Example 1, the composition for forming the light absorption anisotropic layer was set as P4 as described below. Otherwise, the optical film 7 was manufactured in the same manner as in Comparative Example 1.

[0671]

[0672]

[0673] <Comparative Example 3>

[0674] In the optical film 3 of Example 3, no hue adjustment layer was provided; otherwise, the optical film 8 was fabricated in the same manner as in Example 3.

[0675] <Example 6>

[0676] [Formation of the photo-alignment layer]

[0677] In the same manner as in Example 1, a TAC film 1 with an alignment film was prepared. The following photo-alignment layer forming solution E1 was coated onto the alignment film AL1 and dried at 60°C for 2 minutes. Then, the resulting coated film was irradiated with ultraviolet light (2000 mJ / cm²) from a polar angle of 15° with reference to the film normal direction using an ultraviolet exposure apparatus. 2 Thus, a photo-alignment layer E1 with a thickness of 0.03 μm was fabricated.

[0678] [Preparation of the composition solution E1 for photo-alignment layer formation]

[0679] Prepare a photo-alignment layer forming solution E1 with the following composition, and dissolve it while stirring for 1 hour.

[0680] After dissolution, the solution was filtered using a 0.45μm filter to obtain the composition solution F1 for photo-alignment layer formation.

[0681]

[0682]

[0683] Photo-alignment material E-3

[0684] [Chemical Formula 46]

[0685]

[0686] [Formation of the light-absorbing anisotropic layer P9]

[0687] On the obtained light-aligned layer E1, a light-absorbing anisotropic layer forming composition P1 is continuously coated using a winding bar, and after heating at 120°C for 60 seconds, it is cooled to room temperature (23°C).

[0688] Next, heat at 80°C for 60 seconds and then cool to room temperature again.

[0689] Then, using an LED light (center wavelength 365nm) at an illuminance of 200mW / cm² 2 Irradiate for 2 seconds under the irradiation conditions, thereby creating a light-absorbing anisotropic layer P9 on the alignment film AL1.

[0690] The thickness of the light-absorbing anisotropic layer P9 is 3.5 μm. The angle between the central axis of the transmittance of the light-absorbing anisotropic layer P9 and the normal to the thin film is 15 degrees.

[0691] [The formation of the C9 hue adjustment layer]

[0692] On the obtained light absorption anisotropic layer P9, a hue adjustment layer forming composition C1 was coated, and an optical film 9 was obtained in the same manner as in Example 1.

[0693] <Examples 7-10>

[0694] In the optical film 1 of Example 1, the film thickness d(C) of the tone adjustment layer was changed, and the value represented by (c(C)×d(C)) / (c(P)×d(P)) in the above formula (7) was adjusted to the value shown in Table 2. Otherwise, the optical films 10 to 13 were made in the same manner as in Example 1.

[0695] <Example 11>

[0696] In the optical film 1 of Example 1, after forming the light absorption anisotropic layer P1, the alignment film was formed again using the alignment film forming composition 1 in the same manner as the alignment film AL1. Then, the hue adjustment layer forming composition C1 was changed to the hue adjustment layer forming composition C4. Otherwise, the optical film 14 of Example 11 was produced in the same manner as in Example 1.

[0697]

[0698]

[0699] <Evaluation>

[0700] [Evaluation of Orientation]

[0701] (Anisotropic light absorption layer)

[0702] The orientation degree of the obtained optically absorbing anisotropic layer at a wavelength of 550 nm was calculated using the following method.

[0703] When using an AxoScan OPMF-1 (manufactured by Opto Science, Inc.) for measurement, the Miller matrix at a wavelength of 550 nm was measured at each polar angle, changing the angle of the anisotropic absorption layer relative to the normal direction (i.e., the polar angle) from 0 to 90° in 5° increments, and the minimum transmittance (Tmin) was derived. Then, after removing the influence of surface reflection, Tmin at the highest polar angle was designated as Tm(0), and Tmin at the direction where the polar angle increases by 40° from the highest Tmin was designated as Tm(40). Based on the obtained Tm(0) and Tm(40), the absorbance (A) was calculated using the following formula, and A(0) and A(40) were calculated.

[0704] A = -log(Tm)

[0705] Here, Tm represents transmittance and A represents absorbance.

[0706] Using the calculated A(0) and A(40), the orientation degree S at a wavelength of 550 nm, as defined by the following formula, was calculated. P .

[0707] S=(4.6×A(40)-A(0)) / (4.6×A(40)+2×A(0))

[0708] By changing the wavelength from 550nm to 420nm or 650nm, the orientation degree S at wavelengths of 420nm and 650nm was calculated. P .

[0709] (Tone Adjustment Layer)

[0710] From the obtained optical film, only the tone adjustment layer was transferred onto a cellulose acylate film (40 μm thick TAC substrate; TG40 FUJIFILM Corporation) via an adhesive. Using this transferred film, the orientation degree S of the tone adjustment layer was determined in the same manner as that of the light absorption anisotropic layer. C .

[0711] [Evaluation of transmittance and hue]

[0712] Using a measuring instrument (EZ-Contrast XL88, ELDIM Company), the following measurements were taken of the image display device T1: the luminance Y(0)A1 of the white display screen along the central axis; the luminance Y(30)A1 of the plane formed by the central axis of transmittance and the normal to the thin film in the direction (tilt direction) deviating 30° from the central axis of transmittance; and the hue a of the central axis of transmittance. * (0)A1、b * (0)A1, Hue a in the direction deviating 30° from the central axis of transmittance in the plane formed by the transmittance center axis and the film normal. * (30)A1、b * (30)A1.

[0713] Furthermore, in the fabrication of image display device I1, an optical laminate without a light-absorbing anisotropic layer was bonded to the liquid crystal cell. Otherwise, image display device B was fabricated in the same manner as in Example 1, and the luminance Y(0)B of the white display screen at an anisotropic angle of 0° (front direction) was measured in the same manner as described above. The front transmittance T(0) was determined by comparing it with the luminance of image display device B without a light-absorbing anisotropic layer.

[0714] Specifically, the following formula is used for calculation.

[0715] T(0)=Y(0)A1 / Y(0)B

[0716] Transmittance and hue were evaluated according to the following evaluation criteria.

[0717] (Evaluation criteria for transmittance)

[0718] A: T(0) is above 75%

[0719] B: T(0) is 65% or more and less than 75%.

[0720] C: T(0) is less than 65%

[0721] (Evaluation criteria for color tone)

[0722] A: |a * (0)| Less than 3

[0723] B:|a * (0)| is 3 or more and less than 5

[0724] C:|a * (0)| is 5 or above

[0725] Furthermore, b was evaluated in the same way. * (0), a * (30), and b* (30)

[0726] Furthermore, the image display devices made by replacing optical films 2 to 8 with optical film 1 were respectively set as I2 to I8, and the transmittance and hue were evaluated in the same way.

[0727] The evaluation results are shown in Table 1.

[0728] In Table 1, "polar angle" represents the angle between the transmittance center axis of the optical film and the normal direction of the optical film.

[0729] In Table 1, the "A" mark in the "Orientation Degree" column indicates the orientation degree S of the tone adjustment layer measured at 450nm, 550nm, and 650nm using the method described above. C All are less than 0.1. That is, the "A" mark in the "Orientation Degree" column indicates that all the above requirements 1 to 3 are met. Furthermore, in Table 1, the "B" mark in the "Orientation Degree of Tone Adjustment Layer" column indicates the orientation degree S of the tone adjustment layer measured at 450nm, 550nm, and 650nm. C Any one of them is greater than 0.1.

[0730] In Table 1, “S” P (450)”S P (550)” and “S” P (650) indicates the orientation degree of the optical film measured at 450nm, 550nm and 650nm respectively.

[0731] In Table 1, “S” P (450) < S P (550)” and “S” P (450) < S P In column (650), the "A" mark indicates that the inequalities are true, and the "B" mark indicates that the inequalities are false. Additionally, "S" P (450) < S P (550)” and “S” P (450) < S P (650)” corresponds to the above formulas (1) and (2) respectively.

[0732]

[0733] Based on Table 1, the results of the embodiments and comparative examples were compared, confirming that the optical film of the embodiments has excellent wide-range modulation suppression.

[0734] According to Table 1, the results of the embodiments were compared and it was confirmed that if the light absorption anisotropic layer satisfies the above formulas (1) and (2), the transmittance of the optical film is better.

[0735] According to Table 1, it is confirmed that if at least one of the dichroic pigment compounds contained in the light absorption anisotropic layer is the dichroic pigment compound represented by the above formula (3), then the transmittance of the optical film is more excellent.

[0736] According to Table 1, it was confirmed that when the tone adjustment layer meets the above requirements 1 to 3, the wide-range tone suppression performance of the optical film is better.

[0737] According to Table 1, it was confirmed that when the absorption peak wavelength of the organic pigment compounds contained in the hue adjustment layer is 500-650 nm, the optical film has better wide-range hue modulation suppression.

[0738] Table 2 shows the results of evaluating the above formula (7) and hue for Examples 1, 7-10 and Comparative Example 1.

[0739] Furthermore, the orientation degree of the tone adjustment layer was 0 at any of the measurements at 420nm, 550nm, and 650nm.

[0740] In Table 2, “(c(C)×d(C)) / (c(P)×d(P))” is marked as the value corresponding to the above formula (7).

[0741] [Table 2]

[0742]

[0743] According to Table 2, it is confirmed that when the optical film satisfies the above formula (7), the wide-range modulation suppression performance of the optical film is better.

[0744] (Confirm the appropriateness of the surface machining)

[0745] [Appropriateness of surface machining]

[0746] On the curved display screen of a smartphone (Galaxy Note9, manufactured by Samsung), the optical laminate A1 prepared in Example 1 was bonded using commercially available adhesive SK2057 (manufactured by Soken Chemical & Engineering Co., Ltd.) with the optical film 1 side as the display screen side. The film thickness of the optical laminate A1 is less than 100 μm, and it is highly flexible, preventing air bubbles from entering even on the curved parts of the display screen, allowing for clean bonding.

[0747] Next, using commercially available adhesive SK2057 (manufactured by Soken Chemical & Engineering Co., Ltd.), a venetian blind-type optical film (3M Security / Privacy Filter PF12 H2 series), which has the same performance as the optical film of the present invention and is widely available in the market, was adhered to the display screen of the aforementioned smartphone. The aforementioned venetian blind-type optical film has a thickness of 500 μm and low flexibility, allowing air bubbles to enter on the curved surfaces of the display screen, resulting in imperfect adhesion.

[0748] [Evaluation of Patterned Items]

[0749] An anisotropic light absorption layer with the patterns of the aforementioned regions A and B was fabricated as described below and evaluated.

[0750] (Formation of anisotropic patterned light absorption layer)

[0751] The above-described light-absorbing anisotropic layer forming composition P1 was continuously coated onto the alignment film AL1 of Example 1 using a winding bar to form a coating layer P1.

[0752] Next, the coating layer P1 was heated at 140°C for 30 seconds and then cooled to room temperature (23°C).

[0753] Next, heat at 80°C for 60 seconds and then cool to room temperature again.

[0754] Then, at an illuminance of 28 mW / cm² 2 Under the irradiation conditions, light emitted from a high-pressure mercury lamp is irradiated through a mask for 60 seconds, thereby creating a light-absorbing anisotropic layer on the alignment film AL1, consisting of a cured region with a liquid crystal compound and an uncured region. Furthermore, the mask is a mask pattern with a rectangular light-transmitting portion of 10mm x 50mm as region A, and a light-blocking portion (region B) and a light-transmitting portion.

[0755] A thin film having a polarizing layer with a cured region (region A) and an uncured region (region B) containing a liquid crystal compound in its in-plane structure is immersed in ethanol for 3 minutes, and then cleaned to remove the unpolymerized liquid crystal compound, thereby forming a patterned optical film 10 with patterned light-absorbing anisotropic layers having different polarization degrees in regions A and B in its in-plane structure. Region A has a transmittance of less than 10% at a polar angle of 30° and a front transmittance of more than 80%. Region B has a transmittance of more than 80% at both a polar angle of 30° and a front transmittance.

[0756] -Fabrication of the optical laminate A10-

[0757] The optical laminate A10 is fabricated by bonding the exposed polarizer surface of the polarizer 1 to the surface of the light absorption anisotropic layer of the patterned optical film 10 using the adhesive sheet 1 described above.

[0758] -The creation of the image display device I10-

[0759] The image display device I10 was manufactured by changing the optical laminate A1 to an optical laminate A10 in the same manner as the image display device I1 described above. Only part of region A has a narrow field of view, and it can only be clearly visually recognized from the front.

[0760] [Evaluation of Surface Textured Products]

[0761] An optical laminate with the aforementioned surface irregularities was fabricated as described below and evaluated.

[0762] (The fabrication of the image display device I11)

[0763] In order to give the surface unevenness Ra90nm, the surface unevenness film described in Example 3 of Japanese Patent No. 6093153 was attached to the exposed surface of the polarizer of the polarizer 1 using the adhesive sheet 1 described above, thereby creating an optical laminate A11.

[0764] The image display device I11 was manufactured by changing the optical laminate A1 to an optical laminate A11 in the same manner as the image display device I1 described above.

[0765] (The fabrication of the image display device I12)

[0766] In order to give the surface unevenness Ra50nm, the surface unevenness film described in Example 101 of Japanese Patent No. 5909454 was attached to the exposed surface of the polarizer of the polarizer 1 using the adhesive sheet 1 described above, thereby creating an optical laminate A12.

[0767] The optical laminate A1 was changed to an optical laminate A12 in the same manner as the image display device I1 described above, thereby creating the image display device I12.

[0768] (The fabrication of the image display device I13)

[0769] In order to give Ra 130nm surface unevenness, the surface unevenness film described in Example 7 of Japanese Patent No. 6093153 was attached to the exposed surface of the polarizer of the polarizer 1 using the adhesive sheet 1 described above, thereby creating an optical laminate A13.

[0770] The image display device I13 was manufactured by changing the optical laminate A1 to the optical laminate A13 in the same manner as the image display device I1 described above.

[0771] (Evaluation: Anti-adhesion)

[0772] For each optical laminate of the embodiment, the adhesion between the outermost surfaces of the optical laminates when they are bonded together was evaluated based on the following criteria. The bonded optical laminates are optical laminates of the same embodiment. For example, two optical laminates A1 are bonded together in optical laminate A1. In this way, by bonding optical laminates of the same embodiment together and evaluating them, compared with evaluating the anti-adhesion by bonding other surfaces, the anti-adhesion of the optical laminate can be evaluated more accurately without being affected by the physical properties of the other surfaces being bonded.

[0773] The anti-adhesion property was evaluated according to the following evaluation criteria.

[0774] -Evaluation Criteria for Anti-Adhesion-

[0775] A: There is absolutely no stickiness.

[0776] B: There is almost no stickiness.

[0777] C: Strong adhesion.

[0778] (Evaluation: Narrow field of view)

[0779] For each image display device in the embodiments, the narrow field of view when visually recognizing from the front and when visually recognizing from a 20-degree lateral tilt were evaluated based on the following criteria.

[0780] -Evaluation Criteria for Narrow Field of View-

[0781] A: There is a clear difference in visual recognition between frontal and tilted views.

[0782] B: There is a difference in visual recognition between frontal and tilted views.

[0783] C: It can also be visually identified from the direction of tilt.

[0784] Table 3 shows the anti-adhesion properties of optical laminates A1, A11, A12 and A13, and the evaluation results of narrow field of view of image display devices I1, I11, I12 and I13, respectively, as Examples 1, 11, 12 and 13.

[0785] [Table 3]

[0786] Ra(nm) Anti-adhesion Narrow field of view Example 1 Optical laminate A1 2 C A Example 11 Optical laminate A11 90 A A Example 12 Optical laminate A12 50 B A Example 13 Optical laminate A13 130 A B

[0787] According to Table 3, it was confirmed that if the arithmetic surface roughness Ra of the surface unevenness of the optical laminate of the present invention is 50 nm or more, the anti-adhesion performance when the films are overlapped is better. On the other hand, if the arithmetic surface roughness Ra of the surface unevenness is less than 130 nm, the narrow field of view performance is better.

Claims

1. An optical film having: A light-absorbing anisotropic layer with an angle θ of 0–45° between the transmittance central axis and the normal direction of the layer surface; and a hue-adjusting layer containing at least one organic pigment compound. The tone adjustment layer satisfies any one of the following requirements 1 to 3. Requirement 1: S C (420nm) < 0.1 Requirement 2: S C (550nm) < 0.1 Requirement 3: S C (650nm) < 0.1 in, S C (λnm) represents the orientation degree of the tone adjustment layer as measured at a wavelength of λnm.

2. The optical film according to claim 1, wherein, The light-absorbing anisotropic layer comprises a liquid crystal compound and at least one dichroic pigment compound.

3. The optical film according to claim 1 or 2, wherein, The light-absorbing anisotropic layer satisfies the following equations (1) and (2). S P (420nm)<S P (550nm) Equation (1) S P (420nm)<S P (650nm) Equation (2) Among them, S P (λnm) represents the degree of orientation of the light-absorbing anisotropic layer as measured at a wavelength of λnm.

4. The optical film according to claim 2, wherein, At least one of the dichroic pigment compounds contained in the light-absorbing anisotropic layer is represented by the following formula (3). In the above formula (3), A 4 This indicates a divalent aromatic group that can have substituents. In the above formula (3), L 3 and L 4 Substituents are represented independently. In formula (3), E represents any one of the nitrogen, oxygen, and sulfur atoms. In equation (3), R 1 This represents a hydrogen atom, a halogen atom, an alkyl group that may have substituents, or an alkoxy group that may have substituents. In equation (3), R 2 This represents a hydrogen atom or an alkyl group that may have substituents. In equation (3), R 3 Represents a hydrogen atom or a substituent. In the formula (3), n represents 0 or 1, where n is 1 when E is a nitrogen atom and n is 0 when E is an oxygen atom or a sulfur atom.

5. The optical film according to claim 1 or 2, wherein, The absorption peak wavelength of the organic pigment compounds contained in the hue adjustment layer is 500–650 nm.

6. The optical film according to claim 1 or 2, wherein, The organic pigment compound contained in the hue adjustment layer has at least one structure of benzene ring and heterocycle in its molecule.

7. The optical film according to claim 1 or 2, wherein, The organic pigment compounds contained in the hue adjustment layer have an anthraquinone structure.

8. The optical film according to claim 2, wherein, Satisfy the following equation (7), 0.005≤(c(C)×d(C)) / (c(P)×d(P))≤0.06 (Equation 7) In equation (7), c(C) represents the mass ratio of the organic pigment compound in the hue adjustment layer to the total mass of the hue adjustment layer. In equation (7), d(C) represents the film thickness of the tone adjustment layer, in μm. In equation (7), c(P) represents the mass ratio of the dichroic pigment compound in the light-absorbing anisotropic layer to the total mass of the light-absorbing anisotropic layer. In equation (7), d(P) represents the film thickness of the light-absorbing anisotropic layer, in μm.

9. The optical film according to claim 1 or 2, wherein, The transmittance of light with a wavelength of 550 nm along the direction of the central axis of transmittance is 65% or more.

10. An optical laminate comprising: an optical film according to any one of claims 1 to 9; and a polarizer layer of dichroic material oriented horizontally relative to the film surface.

11. An optical laminate comprising: an optical film as described in any one of claims 1 to 9; and an uneven layer having an arithmetic mean roughness Ra of 35 to 125 nm.

12. An image display device comprising: an optical film according to any one of claims 1 to 9; or an optical laminate according to claim 10 or 11.

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