Azo compounds, compositions, films, laminates, and display devices.

Abstract

Provided are a dichroic dye with improved filtration and stability over time, a composition containing the same, a film formed from the composition, a laminate including the film, and a display device including the laminate. 【Solution means】A dichroic dye containing at least two or more azo compounds represented by the following formula (1), and satisfying the following formulas (2), (3), and (4) simultaneously. TIFF2026058670000017.tif26136δD d =(δD max -δD min ) / δD max ≧ 0.04 (2) δP d =(δP max -δP min ) / δP max ≧ 0.20 (3) δH d =(δH max -δH min ) / δH max ≧ 0.20 (4)

Description

[Technical Field]

[0001] The present invention relates to azo compounds, compositions, films, laminates, and display devices. [Background technology]

[0002] Polarizing films (optical films) used in liquid crystal display devices and the like are known to consist of compositions containing dichroic dyes. As such dichroic dyes, for example, Patent Document 1 describes an azo dye having a branched alkyl group represented by the following formula.

[0003] [ka] [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-88325 [Overview of the project] [Problems that the invention aims to solve]

[0005] To produce a polarizing film consisting of a composition containing a dichroic dye represented by the above formula, a composition containing a solvent is prepared and the solvent is removed after coating. However, there have been problems with the filterability before coating and the stability over time after coating. The object of the present invention is to provide a dichroic dye with improved filterability and stability over time, a composition containing the same, a film formed from the composition, a laminate comprising the film, and a display device comprising the laminate. [Means for solving the problem]

[0006] The present invention provides the following [1] to

[11] . [1] A dichroic dye containing at least two or more azo compounds represented by the following formula (1). Among the azo compounds contained in the dichroic dye, the dispersion term in the Hansen solubility parameter (HSP) of the azo compound having the largest dispersion term is δD max , the dispersion term of the azo compound having the smallest dispersion term is δD min , the polar term of the azo compound having the largest polar term is δP max , the polar term of the azo compound having the smallest polar term is δP min , the hydrogen bond term of the azo compound having the largest hydrogen bond term is δH max , the hydrogen bond term of the azo compound having the smallest hydrogen bond term is δH min . When defined as such, the difference rate δD of the dispersion term d , the difference rate δP of the polar term d , the difference rate δH of the hydrogen bond term d are dichroic dyes that simultaneously satisfy the following formulas (2), (3), and (4).

Chemical formula

[10] [9]. A display device comprising the film described in

[11] [9] or the laminate described in

[10] . [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a dichroic dye that has improved filterability and stability over time, a composition containing the same, a film formed from the composition, a laminate comprising the film, and a display device comprising the laminate. [Modes for carrying out the invention]

[0008] In this specification, the term "process" includes not only independent processes but also processes that cannot be clearly distinguished from other processes, as long as their intended purpose is achieved. Furthermore, the content of each component in a composition refers to the total amount of multiple substances present in the composition, unless otherwise specified, if multiple substances corresponding to each component exist in the composition. In addition, the upper and lower limits of the numerical ranges described herein can be arbitrarily selected and combined from the numerical values ​​exemplified as numerical ranges. Embodiments of the present invention will now be described in detail. It should be noted that the scope of the present invention is not limited to the embodiments described herein, and various modifications can be made without impairing the spirit of the invention.

[0009] Azo compound The azo compound according to one embodiment of the present invention is represented by the following formula (1). The azo compound may be, for example, a dichroic dye compound and may be used as a material for forming a polarizing film. The azo compound represented by formula (1) is thought to have a long-chain structure in which the aliphatic hydrocarbon group linked to L has a strong interaction with the side chains of the liquid crystal molecules constituting the polarizing film. Furthermore, it is thought that having an asymmetric branched chain structure can maintain a good liquid crystal state during the cooling process of the coating film. Furthermore, for example, R constituting the branched chain L and R S It is believed that having aliphatic hydrocarbon chains of varying lengths helps maintain a good liquid crystal state during the cooling process of the coating film. These effects are thought to suppress the occurrence of unevenness after the polarizing film is formed.

[0010] [ka]

[0011] In formula (1), Ar 1 Ar 2 and Ar 3 Each of these independently represents an optionally substituted 1,4-phenylene group, an optionally substituted 1,4-naphthylene group, or an optionally substituted divalent heterocyclic group. The heterocyclic group may be an aromatic heterocyclic group, and may be an aromatic condensed heterocyclic group formed by the condensation of two 5-membered aromatic condensed heterocyclic rings. 1 Ar 2 and Ar 3 At least one of these represents a divalent heterocyclic group formed by the condensation of two sulfur-containing aromatic rings, which may have substituents. 1 Ar 2 or Ar 3 The divalent heterocyclic group represented by is formed by removing two hydrogen atoms from a heterocyclic compound. Examples of heterocyclic compounds include five-membered aromatic heterocyclic compounds such as thiophene, thiazole, and furan, and aromatic condensed heterocyclic compounds formed by the condensation of such aromatic heterocyclic compounds with other aromatic heterocyclic compounds or aromatic hydrocarbon compounds. Specific examples of heterocyclic compounds include thiophene, thiazole, furan, thienothiophene, dithienothiophene, thienothiazole, thiazolothiazole, furanothiazole, and benzothiazole. 1 Ar 2 or Ar 3 Specifically, examples of the divalent heterocyclic group represented by include thiophenediyl group, thiazolediyl group, dithieno[3,2-b;2',3'-d]thiophenediyl group, thieno[3,2-d]thiazolediyl group, thieno[3,2-d]thiophenediyl group, thiazolo[5,4-d]thiazolediyl group, furano[3,2-d]thiazolediyl group, benzothiazolediyl group, etc., and may include at least one selected from the group consisting of these. The heterocyclic group preferably includes at least one selected from the group consisting of thieno[3,2-d]thiazolediyl group and thieno[3,2-d]thiophenediyl group.

[0012] Ar 1Preferably, may represent a substituted 1,4-phenylene group or a substituted divalent heterocyclic group, or may represent a substituted 1,4-phenylene group. 3 Preferably, this represents a 1,4-phenylene group which may have a substituent.

[0013] Ar 2 This may represent a divalent heterocyclic group which may have substituents, and is a heterocyclic group formed by the condensation of two sulfur-containing aromatic rings, which may represent a divalent heterocyclic group which may have substituents. 2 The heterocyclic group represented by may be formed, for example, by removing two hydrogen atoms from an aromatic condensed heterocyclic compound obtained by condensing two 5-membered sulfur-containing aromatic heterocyclic compounds. Examples of 5-membered sulfur-containing aromatic heterocyclic compounds include thiophene and thiazole. Specific examples of heterocyclic groups formed by the condensation of two sulfur-containing aromatic rings include thieno[3,2-d]thiazolediyl group, thieno[3,2-d]thiophenediyl group, and thiazolo[5,4-d]thiazolediyl group, and may include at least one selected from the group consisting of these. The heterocyclic group formed by the condensation of two sulfur-containing aromatic rings preferably includes at least one selected from the group consisting of thieno[3,2-d]thiazolediyl group and thieno[3,2-d]thiophenediyl group.

[0014] Ar 1 Ar 2 and Ar 3 The substituents in may include at least one selected from the group consisting of a halogen atom, a hydroxyl group, a C1 to C3 alkyl group, and a C1 to C3 alkoxy group, preferably at least one selected from the group consisting of a halogen atom, a hydroxyl group, a methyl group, and a methoxy group, and more preferably at least one selected from the group consisting of a fluorine atom, a chlorine atom, a hydroxyl group, a methyl group, and a methoxy group. 1 Ar 2 and Ar 3The substitution base numbers may each independently be, for example, 0, 1 or 2, and preferably may be 0 or 1.

[0015] k is 1 or 2, and preferably may be 1. When k is 2, the two Ars 2 may be the same or different from each other.

[0016] R 2 and R 3 each independently represent an aliphatic hydrocarbon group having 1 to 10 carbon atoms which may have a substituent. The number of carbon atoms of the aliphatic hydrocarbon group may preferably be 1 to 8, or 1 to 6. The aliphatic hydrocarbon group may be branched or linear. Examples of the aliphatic hydrocarbon group include an alkyl group, an alkenyl group, and an alkynyl group, and preferably an alkyl group. Specific examples of the alkyl group include a methyl group, an ethyl group, and a propyl group. R 2 and R 3 may be linked to each other to form an aliphatic ring, and a part of the methylene group constituting the aliphatic hydrocarbon group represented by R 2 or R 3 may be substituted with an oxygen atom or a carbonyl group. The formed ring may be a nitrogen-containing aliphatic ring, and the number of its members may be, for example, 5 or 6. Rings formed by R 2 and R 3 bonding to each other include, for example, a pyrrolidyl group, a piperidyl group, an oxazolidinyl group, a morpholyl group, and the like.

[0017] R S represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 12 carbon atoms which may have a substituent. The number of carbon atoms of the aliphatic hydrocarbon group represented by R S may preferably be 4 or more and 8 or less, and more preferably 4 or more and 6 or less. R L represents a hydrogen atom or an aliphatic hydrocarbon group which may have a substituent, and the number of carbon atoms of R L is the same as or more than the number of carbon atoms of R S R LThe number of carbon atoms of the aliphatic hydrocarbon group represented by may preferably be 6 or more and 14 or less, and more preferably 6 or more and 8 or less. R L The difference in the number of carbon atoms between R S and R L may be, for example, 1 or more and 10 or less, and preferably 2 or more and 6 or less. The sum of the number of carbon atoms of R S and R

[0018] R S or R L The aliphatic hydrocarbon group represented by may be either branched or linear, and preferably linear. Examples of the aliphatic hydrocarbon group include an alkyl group, an alkenyl group, and an alkynyl group, and preferably an alkyl group.

[0019] R 2 R 3 R S and R L At least one selected from the group consisting of may have a polymerizable group as a substituent. Specific examples of the polymerizable group include a (meth)acrylate group ((meth)acryloyloxy group), a (meth)acryloyl group, a vinylphenyl group, a vinyl group, an epoxy group, and the like. The polymerizable group may be, for example, a radically polymerizable group, and preferably a (meth)acrylate group. The total number of polymerizable groups possessed by R 2 R 3 R S and R L may be, for example, 1 or 2, and preferably 1.

[0020] L represents a linking group formed from at least one selected from the group consisting of -O-, -S-, -C(=O)-, and linear or branched alkylene groups having 1 to 4 carbon atoms. From the viewpoint of compound stability, the linking group represented by L is preferably selected so as not to contain oxygen-oxygen bonds, sulfur-sulfur bonds, or oxygen-sulfur bonds. If L contains multiple alkylene groups, they may be different from each other or may be the same. Specific examples of the divalent group represented by L include alkylene groups, alkylene oxy groups, alkylene oxycarbonyl groups, alkylene carbonyl oxy groups, alkylene carbonyl groups, oxyalkylene groups, oxycarbonylalkylene groups, carbonyl oxyalkylene groups, carbonylalkylene groups, carbonylalkylene oxy groups, alkylene oxyalkylene groups, carbonyl oxyalkylene oxy groups, carbonyl oxyalkylene oxyalkylene groups, carbonylalkylene oxy groups, carbonylalkylene oxyalkylene groups, alkylene sulfanyl groups, sulfanylalkylene groups, alkylene sulfanylalkylene groups, and carbonyl oxyalkylene sulfanyl groups. The total number of carbon atoms other than carbonyl carbons among the carbon atoms constituting L may be, for example, 1 to 8, preferably 1 to 6, 1 to 4, or 1 to 3. In one embodiment, L may be represented by the following formula (1a).

[0021] [ka]

[0022] In formula (1a), R 4 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. 4 The number of carbon atoms in the alkyl group represented by is preferably 1 to 2, or may be 1. Two R groups bonded to the same carbon atom 4Of these, at least one may be a hydrogen atom, and both may be hydrogen atoms. P and Q independently represent a single bond, -O-, -OC(=O)-, -C(=O)O-, or -S-. x and y independently represent a number from 0 to 4. The total number of carbon atoms other than the carbonyl carbon in the linking group represented by formula (1a) may be, for example, 1 to 8, preferably 1 to 6, 1 to 4, or 1 to 3. * represents a bond position.

[0023] Specific examples of azo compounds represented by formula (1) include the azo compounds represented by formulas (1-1) to (1-39) below, but the present invention is not limited to these.

[0024] [ka]

[0025] From the viewpoint of improving filterability and stability over time, the azo compound represented by formula (1) preferably includes at least two selected from the group consisting of azo compounds represented by any of formulas (1-1) to (1-39).

[0026] Method for producing azo compounds The azo compound represented by formula (1) can be produced by appropriately applying conventionally known synthesis methods. Specifically, for example, the production method described in Japanese Patent Application Publication No. 2022-088325 can be referred to.

[0027] Dichroic pigments A dichroic dye contains two or more azo compounds represented by formula (1) with different structures as active ingredients. The two or more azo compounds represented by formula (1) may have different maximum absorption wavelengths. In addition, the dichroic dye may contain other dye compounds in addition to the azo compounds represented by formula (1).

[0028] When the Hansen solubility parameter (HSP) of an azo compound represented by formula (1) included in dichroic dyes is denoted by δD for the dispersion term, δP for the polar term, and δH for the hydrogen bonding term, these can be calculated using, for example, the book: "Hansen Solubility Parameters: A user's handbook, Second Edition", Hansen, Charles (2007) or software: HSPiP, etc.

[0029] Among the azo compounds represented by formula (1) included in dichroic dyes, the dispersion term of the azo compound whose dispersion term in the Hansen solubility parameter (HSP) is maximized is δD. max The dispersion term of the azo compound that minimizes the dispersion term is δD min The polar term of the azo compound that maximizes the polar term is δP max The polarity term of the azo compound that minimizes the polarity term is δP min The hydrogen bonding term of the azo compound with the maximum hydrogen bonding term is δHmax, and the hydrogen bonding term of the azo compound with the minimum hydrogen bonding term is δH min In this case, the difference in the variance term δD d , polarity difference rate δP d , difference in hydrogen bonding term δH d These can be calculated using the following formulas (7), (8), and (9). δD d =(δD max -δD min ) / δD max (7) Erotica P d =(δP max -δP min ) / δP max (8) δH d =(δH max -δH min ) / δH max (9) To obtain the pre-coating filterability and post-coating stability of the composition described later, the difference in the dispersion term δD d The difference ratio δP of the polarity term is 0.04 or greater. d is 0.20 or greater, the difference rate δH of the hydrogen bonding term. dIt is preferable that the difference rate δD of the variance term is 0.20 or higher. d The difference ratio δP of the polarity term is 0.05 or greater. d is 0.25 or greater, the difference rate δH of the hydrogen bonding term. d It is more preferable that the value is 0.30 or higher. In order to suppress the occurrence of unevenness caused by differences in absorbance within the plane, the difference rate δD of the dispersion term is d is 0.10 or less, the difference ratio δP of the polarity term d is 0.50 or less, the difference rate δH of the hydrogen bonding term. d It is preferable that the difference rate δD of the variance term is 0.50 or less. d is 0.08 or less, the difference ratio δP of the polarity term d is 0.35 or less, the difference rate δH of the hydrogen bonding term. d It is more preferable that the value be 0.40 or less.

[0030] The dispersion term of the azo compound (1-A) represented by formula (1) contained in the dichroic dye is δD 1-A , the polarity term is δP 1-A , the hydrogen bond term is δH 1-A The dispersion term of the azo compound (1-B) is δD 1-B , the polarity term is δP 1-B , the hydrogen bond term is δH 1-B The dispersion term for the azo compound (1-C) is δD 1-C , the polarity term is δP 1-C , the hydrogen bond term is δH 1-C The ratio of azo compound (1-A) to the total mass of azo compounds represented by formula (1) contained in the dichroic dye is R 1-A The ratio of azo compounds (1-B) is R 1-B The ratio of azo compounds (1-C) is R 1-C In this case, the weighted average of the variance terms δD a , weighted average of polarity terms δP a , weighted average δH of hydrogen bonding terms a These can be calculated using the following formulas (10), (11), and (12). δD a = δD 1-A ×R 1-A +δD 1-B ×R 1-B +δD 1-C ×R1-C (10) Erotica P a = δP 1-A ×R 1-A +δP 1-B ×R 1-B +δP 1-C ×R 1-C (11) δH a = δH 1-A ×R 1-A +δH 1-B ×R 1-B +δH 1-C ×R 1-C (12)

[0031] The CLogP of azo compounds represented by formula (1) included in dichroic dyes can be calculated, for example, using ChemDraw ver.22 (software from PerkinElmer).

[0032] Among the azo compounds represented by formula (1) included in dichroic dyes, the CLogP of the azo compound with the highest CLogP is defined as CLogP. max The CLogP of the azo compound that minimizes CLogP is determined by CLogP. min In that case, the difference rate of CLogP (CLogP d ) can be calculated using the following formula (13). CLogP d =(CLogP max -CLogP min ) / CLogP max (13)

[0033] The CLogP of the azo compound (1-A) represented by formula (1) contained in the dichroic dye is CLogP 1-A , CLogP of azo compound (1-B) CLogP 1-B , CLogP of azo compound (1-C) 1-C The ratio of azo compound (1-A) to the total mass of azo compounds represented by formula (1) contained in the dichroic dye is R 1-A The ratio of azo compounds (1-B) is R 1-B The ratio of azo compounds (1-C) is R1-C In this case, the weighted average of CLogP in a dichroic dye consisting of azo compounds (1-A), (1-B), and (1-C) is (CLogP a ) can be calculated using the following formula (14). CLogP a = CLogP 1-A ×R 1-A +CLogP 1-B ×R 1-B +CLogP 1-C ×R 1-C (14) In order to obtain the filterability of the composition described later before coating, it is preferable that the weighted average of CLogP (CLogPa) be 11 or higher.

[0034] The transition dipole moment ratio (D) of the azo compound represented by equation (1) included in dichroic dyes can be calculated, for example, using Gaussian16 (software from Gaussian, Inc.), by selecting B3LYP as the functional and 6-31g(d) as the basis set, and then calculating the transition dipole moment by TD-DFT calculation after structural optimization. Furthermore, the Ar of the azo compound represented by equation (1) after structural optimization can be calculated. 1 The atoms in L that are directly bonded, and Ar 3 If we define the straight line connecting the nitrogen atoms, excluding the azo group directly bonded to the molecule, as the long axis of the molecule, the transition dipole moment ratio (D) can be calculated from the angle θ between the long axis of the molecule and the transition dipole moment of the transition at which the oscillator strength is maximum, using the following equation (15). D = |1 / tanθ| (15)

[0035] Among the azo compounds represented by formula (1) included in dichroic dyes, the transition dipole moment ratio (D) of the azo compound with the maximum transition dipole moment ratio (D) is defined as D. max The transition dipole moment ratio of the azo compound that minimizes the transition dipole moment ratio is D. min In this case, the difference in the transition dipole moment ratio (D d ) can be calculated using the following formula (16). Dd =(D max -D min ) / D max (16) In order to obtain the time-dependent stability of the composition described later after coating, the difference ratio (D) of the transition dipole moment ratio is used. d ) preferably satisfies 0.05 or more, and the difference rate of the transition dipole moment ratio (D d It is more preferable that the difference rate of the transition dipole moment ratio (D) is 0.06 or higher. In order to suppress the occurrence of unevenness caused by differences in absorbance within the plane, d ) preferably satisfies 0.20 or less, and the difference rate of the transition dipole moment ratio (D d It is more preferable that the value is 0.10 or less.

[0036] The transition dipole moment ratio of the azo compound (1-A) represented by formula (1) in the dichroic dye is D. 1-A The transition dipole moment ratio of the azo compound (1-B) is D 1-B The transition dipole moment ratio of the azo compound (1-C) is D 1-C The ratio of azo compound (1-A) to the total mass of azo compounds represented by formula (1) contained in the dichroic dye is R 1-A The ratio of azo compounds (1-B) is R 1-B The ratio of azo compounds (1-C) is R 1-C In this case, the weighted average of the transition dipole moment ratios (D a ) can be calculated using the following formula (17). D a = D 1-A ×R 1-A +D 1-B ×R 1-B +D 1-C ×R 1-C (17)

[0037] composition The composition of this embodiment comprises a dichroic dye and a liquid crystalline compound comprising at least one polymerizable liquid crystal compound and a liquid crystalline polymer compound. The composition is used, for example, as a material for forming a polarizing film. That is, the composition may be a composition for forming a polarizing film. A polarizing film obtained using the composition as a forming material is a high-quality polarizing film that exhibits a good dichroic ratio and suppresses the occurrence of unevenness caused by differences in absorbance within the plane.

[0038] The content of the azo compound represented by formula (1) in the composition may be, for example, 50 parts by mass or less per 100 parts by mass of solids in the composition, preferably 0.1 parts by mass or more and 10 parts by mass or 0.1 parts by mass or more and 5 parts by mass. Within the above range, sufficient dispersion of the azo compound represented by formula (1) is possible. In this specification, solids refer to the total amount of components excluding volatile components such as solvents from the composition. The composition contains a combination of two or more azo compounds represented by formula (1). The two or more azo compounds represented by formula (1) may have different maximum absorption wavelengths.

[0039] The composition may further contain at least one other dye compound other than the azo compound represented by formula (1), such as a dichroic dye. Examples of other dye compounds include azo dyes such as monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, and stilbeneazo dyes, and at least one selected from the group consisting of these is preferred. The composition may contain one other dye compound alone or two or more in combination. For example, when used as a coated polarizing plate material, it is preferable that the other dye compounds included in the composition have a maximum absorption wavelength in a different wavelength range than the compound represented by formula (1). For example, when used as a coated polarizing plate material, it is preferable that the composition includes the compound represented by formula (1) in combination with three or more dichroic dyes, and more preferably three or more azo dyes. By including three or more dye compounds with different maximum absorption wavelengths in the composition, absorption across the entire visible light spectrum can be obtained, for example, by a film formed from the composition.

[0040] If the composition contains other dye compounds, their content may be, for example, 50 parts by mass or less per 100 parts by mass of the solid content of the composition, preferably 0.1 parts by mass or more and 10 parts by mass or 0.1 parts by mass or more and 5 parts by mass. Within the above range, sufficient dispersion of the other dye compounds is possible.

[0041] The composition contains a crystalline compound comprising, in addition to the azo compound represented by formula (1), at least one polymerizable liquid crystal compound and a crystalline polymer compound. The composition may contain both the polymerizable liquid crystal compound and the crystalline polymer compound, and there may be two or more polymerizable liquid crystal compounds and crystalline polymer compounds included in the composition. By containing at least one polymerizable liquid crystal compound and a crystalline polymer compound, the composition can be made in which the compound represented by formula (1) is dispersed in the crystalline compound.

[0042] The liquid crystalline polymer compound may constitute a thermotropic liquid crystal polymer or a lyotropic liquid crystal polymer. It is preferable that the liquid crystalline polymer compound constitutes a thermotropic liquid crystal polymer because it allows for precise control of film thickness.

[0043] Liquid crystals are classified into smectic liquid crystals, nematic liquid crystals, and cholesteric liquid crystals based on the molecular arrangement structure in the liquid crystal state. Among these, smectic liquid crystals are preferred for polarizing film applications. Therefore, polymerizable liquid crystal compounds are preferably polymerizable smectic liquid crystal compounds, and liquid crystalline polymer compounds are preferably smectic liquid crystal polymer compounds.

[0044] By using polymerizable liquid crystal compounds exhibiting smectic liquid crystal properties and polymer compounds exhibiting smectic liquid crystal properties, a polarizing film with a high degree of orientational order can be formed. The liquid crystal state exhibited by the polymerizable liquid crystal compound and the liquid crystal polymer compound is preferably the smectic phase (smectic liquid crystal state), and more preferably the higher-order smectic phase (higher-order smectic liquid crystal state) from the viewpoint of achieving a higher degree of orientational order. Here, the higher-order smectic phase refers to the smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase, smectic I phase, smectic J phase, smectic K phase, and smectic L phase, and among these, the smectic B phase, smectic F phase, and smectic I phase are more preferred. A polarizing film with a high degree of orientational order yields Bragg peaks derived from higher-order structures such as the hexatic phase and crystal phase in X-ray diffraction measurements. A Bragg peak refers to a peak derived from the planar periodic structure of molecular orientation. The periodic interval (order period) of the polarizing film obtained from the composition is preferably 0.3 nm or more and 0.6 nm or less. The polymerizable liquid crystal compound or liquid crystalline polymer compound may be a polymerizable smectic liquid crystal compound or a smectic liquid crystalline polymer compound that exhibits a Bragg peak derived from a higher-order structure in X-ray diffraction measurements.

[0045] The compound represented by formula (1) can exhibit high dichroism even when dispersed between dense molecular chains, formed from at least one polymerizable smectic liquid crystal compound and a smectic liquid crystal polymer compound. Therefore, a composition containing a liquid crystalline compound comprising at least one polymerizable liquid crystal compound and a liquid crystalline polymer compound, particularly a liquid crystalline compound comprising at least one polymerizable smectic liquid crystal compound and a smectic liquid crystal polymer compound, and the compound represented by formula (1), can provide a polarizing film with a high dichroism ratio in which the occurrence of unevenness due to differences in absorbance within the plane is suppressed.

[0046] A polymerizable liquid crystal compound is a compound that has at least one polymerizable group in its molecule and can exhibit a liquid crystal phase by orientation. Preferably, a polymerizable liquid crystal compound is a compound that can exhibit a liquid crystal phase by orientation alone. A polymerizable group refers to a functional group that can participate in polymerization reactions, and is preferably a radical polymerizable group.

[0047] Specifically, preferred polymerizable liquid crystal compounds include, for example, the compound represented by the following formula (A) (hereinafter also referred to as "polymerizable liquid crystal compound (A)"). U 1 -V 1 -W 1 -(X 1 -Y 1 ) m -X 2 -Y 2 -X 3 -W 2 -V 2 -U 2 (A)

[0048] In equation (A), m is an integer from 1 to 3. 1 , X 2 and X 3 Each independently represents a divalent aromatic group or a divalent alicyclic hydrocarbon group. When m is 2 or 3, X 1 X may be identical or different from each other. 1 , X 2 and X 3 At least three selected from the group consisting of represent a six-membered ring group of a divalent hydrocarbon. 1 , Y 2 , W 1 and W 2 Each of these independently represents a single bond or a divalent linking group. When m is 2 or 3, Y 1 They may be identical or different from one another. 1 and V 2 Each of these independently represents an alkanediyl group having 1 to 20 carbon atoms, which may have substituents. At least one of the -CH2- groups constituting the alkanediyl group may be substituted with -O-, -CO-, -S-, or -NH-. 1and U 2 Each of these independently represents either a polymerizable group or a hydrogen atom, with at least one representing a polymerizable group.

[0049] X 1 , X 2 and X 3 Examples of divalent aromatic groups in this context include 1,4-phenylene groups and 1,4-naphthylene groups. Examples of divalent alicyclic hydrocarbon groups include cyclohexane-1,4-diyl groups. 1 , X 2 and X 3 At least one of the divalent aromatic group and the divalent alicyclic hydrocarbon group in the compound may have substituents. Examples of substituents include C1 to C4 alkyl groups such as methyl, ethyl, and n-butyl groups, cyano groups, and halogen atoms. At least one of the -CH2- groups constituting the divalent alicyclic hydrocarbon group may be substituted with -O-, -S-, or -NR-, where R represents a C1 to C6 alkyl group or a phenyl group.

[0050] X 1 , X 2 and X 3 Examples of the divalent hydrocarbon 6-membered ring group in this compound include a substituted 1,4-phenylene group and a substituted cyclohexane-1,4-diyl group.

[0051] X 1 , X 2 and X 3 The divalent aromatic group in is preferably a substituted 1,4-phenylene group, and more preferably an unsubstituted 1,4-phenylene group. The divalent alicyclic hydrocarbon group is preferably a substituted cyclohexane-1,4-diyl group, more preferably a substituted trans-cyclohexane-1,4-diyl group, and even more preferably an unsubstituted trans-cyclohexane-1,4-diyl group.

[0052] Y 1 and Y 2Each of these independently represents a single bond or a divalent linking group. Examples of divalent linking groups include -CH2CH2-, -CH2O-, -(C=O)O-, -O(C=O)O-, -N=N-, and -CR a =CR b -, -C≡C- and -CR a It is at least one selected from the group consisting of =N-. Here R a and R b Each of these independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. 1 The bond is preferably -CH2CH2-, -(C=O)O-, or a single bond. 2 The group is preferably -CH2CH2- or -CH2O-.

[0053] W 1 and W 2 Each of these independently represents a single bond or a divalent linking group. A divalent linking group is, for example, at least one selected from the group consisting of -O-, -S-, -(C=O)O-, and -O(C=O)O-. 1 and W 2 Each of these is independently and preferably a single bond or an -O-.

[0054] V 1 and V 2 Each of these independently represents an alkanediyl group having 1 to 20 carbon atoms, which may have substituents. At least one of the -CH2- groups constituting the alkanediyl group may be replaced with -O-, -CO-, -S-, or -NH-.

[0055] V 1 and V 2 Examples of alkanediyl groups represented by include methylene, ethylene, propane-1,3-diyl, butane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, decane-1,10-diyl, tetradecane-1,1-diyl, and eicosane-1,20-diyl. 1 and V 2The group is preferably an alkanediyl group having 2 to 12 carbon atoms, and more preferably an alkanediyl group having 6 to 12 carbon atoms.

[0056] Examples of substituents that may be optionally present on an alkanediyl group having 1 to 20 carbon atoms include cyano groups and halogen atoms. Preferably, the alkanediyl group is an unsubstituted alkanediyl group, and more preferably, it is an unsubstituted and linear alkanediyl group.

[0057] U 1 and U 2 Each of these independently represents either a polymerizable group or a hydrogen atom, and at least one of them represents a polymerizable group. 1 and U 2 The group is preferably a polymerizable group. 1 and U 2 It is preferable that both are polymerizable groups, and it is preferable that both are radical polymerizable groups. 1 Polymerizable group shown and U 2 The polymerizable groups indicated by may be different from each other, but it is preferable that they be of the same type. 1 and U 2 The polymerizable groups in this include those similar to the polymerizable groups previously exemplified as polymerizable liquid crystal compounds. Among them, U 1 and U 2 The polymerizable group represented by is preferably at least one selected from the group consisting of vinyloxy group, acryloyloxy group, methacryloyloxy group, oxyranyl group, and oxetanyl group, with acryloyloxy group being more preferred.

[0058] Specific examples of polymerizable liquid crystal compounds (A) include compounds represented by formulas (A-1) to (A-17) below. When polymerizable liquid crystal compound (A) has a cyclohexane-1,4-diyl group, it is preferable that the cyclohexane-1,4-diyl group is in the trans form.

[0059] [ka]

[0060] [ka]

[0061] [ka]

[0062] In particular, the polymerizable liquid crystal compound (A) is preferably at least one selected from the group consisting of compounds represented by any of the following formulas: (A-2), (A-3), (A-4), (A-5), (A-6), (A-7), (A-8), (A-13), (A-14), (A-15), (A-16), and (A-17). The polymerizable liquid crystal compound (A) may be used alone or in combination of two or more.

[0063] Polymerizable liquid crystal compound (A) can be produced by methods described in prior art, such as Lub et al. Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996) and Japanese Patent Publication No. 4719156.

[0064] The liquid crystalline polymer compound may be a compound obtained by polymerizing the polymerizable liquid crystal compound (hereinafter also referred to as a polymer of the polymerizable liquid crystal compound), or it may be any other liquid crystalline polymer compound, and preferably it is a polymer of the polymerizable liquid crystal compound.

[0065] The polymer of the polymerizable liquid crystal compound may use two or more of the polymerizable liquid crystal compounds as raw material monomers. Furthermore, the polymer of the polymerizable liquid crystal compound may also contain other monomers besides the polymerizable liquid crystal compound as raw material monomers.

[0066] The content of the polymerizable liquid crystal compound in the polymer of the polymerizable liquid crystal compound is usually 1 mol% to 100 mol% with respect to the total amount of constituent units derived from the polymerizable liquid crystal compound that constitute the polymer of the polymerizable liquid crystal compound. From the viewpoint of increasing the orientation of the polymerizable liquid crystal compound polymer, it is preferably 30 mol% to 100 mol%, more preferably 50 mol% to 100 mol%, and even more preferably 80 mol% to 100 mol%.

[0067] Other liquid crystalline polymer compounds include polymer compounds having liquid crystalline groups. For example, polymer compounds that form the base structure include polyolefins such as polyethylene and polypropylene; cyclic olefin resins such as norbornene polymers; polyalkylene ethers, polyvinyl alcohol; polymethacrylate esters; polyacrylic acid esters; and these polymer compounds have liquid crystalline groups. Among these, polymethacrylate esters and polyacrylic acid esters having liquid crystalline groups are preferred.

[0068] The aforementioned other liquid crystalline polymer compounds may contain two or more liquid crystalline groups. The liquid crystalline groups may be included in the main chain of the polymer compound forming the parent skeleton, in the side chain of the polymer compound forming the parent skeleton, or in both the main chain and side chain of the polymer compound forming the parent skeleton. Examples of liquid crystalline groups include groups formed by removing one hydrogen atom from a compound having at least two hydrocarbon six-membered ring structures, or groups formed by removing two hydrogen atoms from the same compound.

[0069] The content of liquid crystalline groups in the aforementioned other liquid crystalline polymer compounds is usually 1 mol% to 100 mol% relative to the total amount of constituent units that make up the polymer compound that forms the parent skeleton of the aforementioned other liquid crystalline polymer compounds. From the viewpoint of increasing the orientation of the aforementioned other liquid crystalline polymer compounds, it is preferably 30 mol% to 100 mol%, more preferably 50 mol% to 100 mol%, and even more preferably 80 mol% to 100 mol%.

[0070] In a composition, when two or more polymerizable liquid crystal compounds are combined, it is preferable that at least one of them is polymerizable liquid crystal compound (A), and more preferably that two or more of them are polymerizable liquid crystal compound (A). By combining two or more polymerizable liquid crystal compounds, it may be possible to temporarily maintain the liquid crystal phase even at temperatures below the liquid crystal-crystal phase transition temperature. The content of polymerizable liquid crystal compound (A) in the composition is preferably 40% by mass or more, more preferably 60% by mass or more, based on the total mass of all polymerizable liquid crystal compounds in the composition, and all polymerizable liquid crystal compounds may be polymerizable liquid crystal compound (A). When the content of polymerizable liquid crystal compound (A) is within the above range, the polymerizable liquid crystal compounds tend to align with a high degree of orientational order, and the azo compound represented by formula (1) aligns along this order, thereby obtaining a polarizing film with excellent polarization performance.

[0071] The total content ratio of polymerizable liquid crystal compounds and liquid crystalline polymer compounds in the composition is, from the viewpoint of increasing the orientation of polymerizable liquid crystal compounds and liquid crystalline polymer compounds, for example, 50 parts by mass or more, preferably 70 parts by mass or more and 99.9 parts by mass or less, more preferably 70 parts by mass or more and 99.5 parts by mass or less, even more preferably 80 parts by mass or more and 99 parts by mass or less, particularly preferably 80 parts by mass or more and 94 parts by mass or less, and even more preferably 80 parts by mass or more and 90 parts by mass or less.

[0072] The content of the azo compound represented by formula (1) in the composition is usually 0.1 parts by mass or more and 50 parts by mass or less, preferably 0.1 parts by mass or more and 20 parts by mass or less, more preferably 0.1 parts by mass or more and 10 parts by mass or less, and even more preferably 0.1 parts by mass or more and 5 parts by mass or less, based on 100 parts by mass of the total amount of polymerizable liquid crystal compound and liquid crystalline polymer compound. When the content of the azo compound represented by formula (1) relative to the total amount of polymerizable liquid crystal compound and liquid crystalline polymer compound is 50 parts by mass or less, there is a tendency to obtain a polarizing film with less disorder in the orientation of the polymerizable liquid crystal compound, liquid crystalline polymer compound and the azo compound represented by formula (1), and a high degree of orientation order.

[0073] The composition may further contain a polymer compound in addition to the azo compound represented by formula (1), a polymerizable liquid crystal compound, and a liquid crystalline polymer compound. The inclusion of a polymer compound in the composition may facilitate the dispersion of the azo compound represented by formula (1) within the composition. There are no particular restrictions on the polymer compound that the composition may contain, as long as it can disperse the azo compound represented by formula (1). Acrylic polymers such as polymethyl methacrylate (PMMA) are preferred because they facilitate the uniform dispersion of the azo compound represented by formula (1). The polymer compound may also be a polymer compound obtained by polymerizing the polymerizable liquid crystal compound described above. The weight-average molecular weight of the polymer compound in terms of polystyrene is, for example, 10,000 to 200,000, and preferably 20,000 to 150,000.

[0074] If the composition contains a polymer compound, its content can be appropriately selected depending on the purpose. The content of the polymer compound is preferably 10 parts by mass or less, more preferably 5.0 parts by mass or less, and even more preferably 3.0 parts by mass or less, per 100 parts by mass of the solid content of the composition.

[0075] The composition preferably further comprises a liquid medium such as a solvent and a polymerization initiator, and may optionally further comprise a photosensitizer, polymerization inhibitor, leveling agent, etc.

[0076] The solvent is preferably one that can completely dissolve the azo compound represented by formula (1), the polymerizable liquid crystal compound, the liquid crystalline polymer compound, and the polymer compound. It is also preferable that the solvent is inert to the polymerization reaction of the polymerizable liquid crystal compound.

[0077] Examples of solvents include alcohol solvents, ester solvents, ketone solvents, aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, nitrile solvents, ether solvents, and chlorine-containing solvents. These solvents may be used individually or in combination of two or more types.

[0078] When the composition contains a solvent, the solvent content is preferably 50% by mass or more and 98% by mass or less of the total amount of the composition. In other words, the solid content in the composition is preferably 2% by mass or more and 50% by mass or less. When the solid content is 50% by mass or less, the viscosity of the composition becomes low, and the thickness of the film obtained from the composition, for example, the film becomes substantially uniform, and unevenness tends to occur in the film. The solid content can be determined considering the thickness of the film to be manufactured.

[0079] A polymerization initiator is a compound that can initiate the polymerization reaction of a polymerizable liquid crystal compound. Photopolymerization initiators are preferred because they can initiate the polymerization reaction under lower temperature conditions. Specifically, photopolymerization initiators that can generate active radicals or acids upon the action of light are preferred, and among these, photopolymerization initiators that generate radicals upon the action of light are preferred.

[0080] Examples of polymerization initiators include benzoin compounds, benzophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, triazine compounds, iodonium salts, and sulfonium salts. The polymerization initiator can be appropriately selected from known polymerization initiators depending on the purpose. Furthermore, the polymerization initiator can be used individually or in combination of two or more.

[0081] If the composition contains a polymerization initiator, its content may be appropriately determined according to the type and amount of polymerizable liquid crystal compound contained in the composition. The content of the polymerization initiator is, for example, 0.001 parts by mass or more, 0.01 parts by mass or more, 0.1 parts by mass or more, or 0.5 parts by mass or more per 100 parts by mass of the polymerizable liquid crystal compound, for example, 30% by mass or less, 10% by mass or less, or 8% by mass or less. Furthermore, the content of the polymerization initiator is preferably 0.001 parts by mass or more and 30 parts by mass or less per 100 parts by mass of the polymerizable liquid crystal compound, more preferably 0.01 parts by mass or more and 10 parts by mass or less, and even more preferably 0.1 parts by mass or more and 8 parts by mass or less. When the content of the polymerization initiator is within the above range, polymerization can be carried out without disrupting the orientation of the polymerizable liquid crystal compound.

[0082] If the composition contains a photopolymerization initiator, it may preferably also contain at least one photosensitizer. The inclusion of both a photopolymerization initiator and a photosensitizer tends to further accelerate the polymerization reaction of polymerizable liquid crystal compounds. Examples of such photosensitizers include xanthone compounds such as xanthones and thioxanthones; anthracene compounds such as anthracenes and alkoxy-substituted anthracenes; phenothiazines and rubrenes; and the like. Photosensitizers can be used individually or in combination of two or more.

[0083] If the composition contains a photosensitizer, the amount of photosensitizer in the composition may be appropriately determined according to the type and amount of the photopolymerization initiator and polymerizable liquid crystal compound. The amount of photosensitizer in the composition is preferably 0.1 parts by mass or more and 30 parts by mass or less, more preferably 0.5 parts by mass or more and 10 parts by mass or less, and even more preferably 0.5 parts by mass or more and 8 parts by mass or less, per 100 parts by mass of the polymerizable liquid crystal compound.

[0084] The composition may contain at least one polymerization inhibitor. Examples of polymerization inhibitors include hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (e.g., butylcatechol), pyrogallol, radical scavengers such as 2,2,6,6-tetramethyl-1-piperidinyloxy radical; thiophenols; β-naphthylamines and β-naphthols; and the like. By including a polymerization inhibitor in the composition, the degree of polymerization of the polymerizable liquid crystal compound can be controlled.

[0085] If the composition contains a polymerization inhibitor, the amount of polymerization inhibitor in the composition is preferably 0.1 parts by mass or more and 30 parts by mass or less, more preferably 0.5 parts by mass or more and 10 parts by mass or less, and even more preferably 0.5 parts by mass or more and 8 parts by mass or less, per 100 parts by mass of the polymerizable liquid crystal compound.

[0086] The composition may contain at least one leveling agent. The leveling agent has the function of adjusting the fluidity of the composition and making the coating film obtained by applying the composition flatter, and specifically, surfactants are examples. Preferably, the leveling agent is at least one selected from the group consisting of leveling agents mainly composed of polyacrylate compounds and leveling agents mainly composed of fluorine atom-containing compounds. The leveling agent can be used alone or in combination of two or more types.

[0087] When the composition contains a leveling agent, the content of the leveling agent is preferably 0.05 parts by mass or more and 5 parts by mass or less, and more preferably 0.05 parts by mass or more and 3 parts by mass or less, based on 100 parts by mass of the total amount of the polymerizable liquid crystal compound and the liquid crystalline polymer compound. When the content of the leveling agent is within the above range, the polymerizable liquid crystal compound and the liquid crystalline polymer compound are more easily aligned horizontally, and unevenness is less likely to occur, resulting in a tendency to obtain a smoother film, such as a polarizing film.

[0088] When the leveling agent content is within the above range, it is easy to horizontally orient the polymerizable liquid crystal compound and the liquid crystalline polymer compound, and the resulting film tends to be smoother. When the leveling agent content relative to the polymerizable liquid crystal compound and the liquid crystalline polymer compound exceeds the above range, the resulting film tends to be uneven.

[0089] The composition may contain an antioxidant. The antioxidant is not particularly limited as long as the composition can exhibit the effects of the present invention, and known antioxidants can be used. From the viewpoint of having a high inhibitory effect on the photodegradation of the azo compound (1), so-called primary antioxidants that scavenge radicals and have an effect of preventing auto-oxidation are preferred. Therefore, it is more preferable that the antioxidant contained in the composition be at least one selected from the group consisting of phenolic compounds, alicyclic alcohol compounds, and amine compounds. The antioxidant may be used alone or in combination of two or more.

[0090] The content of the antioxidant in the composition is preferably 0.1 parts by mass to 15 parts by mass, more preferably 0.3 parts by mass or more, even more preferably 0.5 parts by mass or more, even more preferably 12 parts by mass or less, and even more preferably 10 parts by mass or less, per 100 parts by mass of the composition. If the content of the antioxidant is above the lower limit, the photodegradation of the azo compound (1) can be suppressed more effectively. Furthermore, if the content of the antioxidant is below the upper limit, the orientation of the polymerizable liquid crystal compound is less likely to be disrupted, and a higher inhibitory effect on the photodegradation of the azo compound (1) can be expected.

[0091] The composition may contain other additives not listed above. Examples of other additives include mold release agents, stabilizers, colorants such as bluing agents, flame retardants, and lubricants. If the composition contains other additives, the content of the other additives is preferably more than 0% and 20% by mass or less, and more preferably more than 0% and 10% by mass or less, relative to the solid content of the composition.

[0092] The composition can be prepared by conventionally known methods for preparing compositions. For example, it can be prepared by mixing and stirring an azo compound represented by formula (1), a liquid crystalline compound, and, if necessary, additives such as antioxidants and leveling agents.

[0093] film The film according to this embodiment may be a film containing an azo compound represented by formula (1) as a forming material, or it may be a film obtained using a composition containing an azo compound represented by formula (1) and a liquid crystalline compound as a forming material. A film made of a composition may be formed by applying the composition to a substrate and forming a film. Furthermore, if the composition contains a polymerizable liquid crystal compound, a film containing a cured product obtained by polymerizing the polymerizable liquid crystal compound may be formed by applying the composition to a substrate, forming a film, then polymerizing the polymerizable liquid crystal compound and curing it.

[0094] The composition can form a film, such as a polarizing film, that has a high degree of orientational order and suppresses the occurrence of unevenness caused by differences in absorbance within the plane. Therefore, the film according to this embodiment includes a polarizing film formed from a composition comprising an azo compound represented by formula (1) and a liquid crystalline compound, which has a high degree of orientational order and suppresses the occurrence of unevenness caused by differences in absorbance within the plane.

[0095] In polarizing films with a high degree of orientational order, Bragg peaks originating from higher-order structures such as the hexatic phase and the crystalline phase are obtained in X-ray diffraction measurements. Therefore, it is preferable that the polarizing film formed from the composition is oriented such that the polymerizable liquid crystal compound or liquid crystalline polymer compound exhibits a Bragg peak in X-ray diffraction measurements, and it is more preferable that the molecules of the polymerizable liquid crystal compound or liquid crystalline polymer compound are oriented in the direction that absorbs light, resulting in a "horizontal orientation." A high degree of orientational order that exhibits a Bragg peak can be achieved by controlling the type of polymerizable liquid crystal compound or liquid crystalline polymer compound used, the amount of the azo compound represented by formula (1), etc.

[0096] The azo compound and liquid crystalline compound represented by formula (1) that constitute the composition used to form the film are as previously described.

[0097] The membrane can be manufactured, for example, by a method including the following steps: Step 1: Form a coating film of a composition containing an azo compound represented by formula (1), a liquid crystalline compound, and a solvent. Step 2: Remove at least a portion of the solvent from the coating film. Third step: After raising the temperature to above the temperature at which the liquid crystalline compound undergoes a phase transition to the liquid phase, the temperature is lowered to cause the liquid crystalline compound to undergo a phase transition to the smectic phase (smectic liquid crystal state), and Step 4: If necessary, polymerize the polymerizable liquid crystal compound while maintaining the smectic phase (smectic liquid crystal state).

[0098] The composition can be formed by, for example, applying it to a substrate, an alignment film (described later), or the like. Alternatively, the composition may be directly applied to a phase difference film or other layers that constitute a polarizing plate.

[0099] The substrate is usually a transparent substrate. However, when the substrate is not installed on the display surface of the display element, for example, when a laminate obtained by removing the substrate from a film is installed on the display surface of the display element, the substrate does not have to be transparent. A transparent substrate means a substrate that has transparency that can transmit light, especially visible light, and transparency refers to the characteristic that the transmittance for light rays in the wavelength range of 380 nm to 780 nm is 80% or more. A specific example of a transparent substrate is a light-transmitting resin substrate.

[0100] Examples of resins constituting the translucent resin substrate include polyolefins, cyclic olefin resins, polyvinyl alcohol, polyethylene terephthalate, polymethacrylate, polyacrylic acid esters, cellulose esters, polyethylene naphthalate, polycarbonate, polysulfone, polyethersulfone, polyetherketone, polyphenylene sulfide, and polyphenylene oxide. From the viewpoint of availability and transparency, polyethylene terephthalate, polymethacrylate, cellulose ester, cyclic olefin resins, or polycarbonate are preferred.

[0101] The properties required of the substrate vary depending on the film structure, but generally, a substrate with the smallest possible phase difference is preferred. Examples of substrates with the smallest possible phase difference include cellulose ester films that have no phase difference, such as ZeroTack (Konica Minolta Opto, Inc.) and ZTack (Fujifilm Corporation). Unstretched cyclic olefin resin substrates are also preferred. The surface of the substrate without a laminated film may be treated with a hard coat, anti-reflective coating, anti-static coating, etc.

[0102] The thickness of the substrate is usually between 5 μm and 300 μm, preferably between 20 μm and 200 μm, and more preferably between 20 μm and 100 μm. If the thickness is above the lower limit, the decrease in strength is suppressed and processability tends to improve.

[0103] Methods for applying the composition to a substrate include known methods such as spin coating, extrusion, gravure coating, die coating, bar coating, and applicator coating, as well as printing methods such as flexographic coating.

[0104] Next, a dried coating film is formed by removing at least a portion of the solvent contained in the coating film obtained from the composition by drying or other means. Furthermore, if the coating film contains a polymerizable liquid crystal compound, a dried coating film is formed by drying under conditions in which the polymerizable liquid crystal compound does not polymerize. Examples of drying methods for the coating film include natural drying, forced-air drying, heat drying, and reduced-pressure drying.

[0105] Furthermore, in order to induce a phase transition of the liquid crystalline compound to the liquid phase, the temperature is raised to above the temperature at which the liquid crystalline compound transitions to the liquid phase, and then the temperature is lowered to induce a phase transition of the liquid crystalline compound to the smectic phase (smectic liquid crystal state). This phase transition may be performed after the removal of the solvent in the coating film, or it may be performed simultaneously with the removal of the solvent.

[0106] When the composition contains a polymerizable liquid crystal compound, a film containing a cured product of the polymerizable liquid crystal compound is formed by polymerizing the polymerizable liquid crystal compound while maintaining its smectic liquid crystal state. Photopolymerization is preferred as the polymerization method. In photopolymerization, the light irradiated onto the dry coating film is appropriately selected according to the type of photopolymerization initiator contained in the dry coating film, the type of polymerizable liquid crystal compound (especially the type of polymerizable group possessed by the polymerizable liquid crystal compound), and its amount. Specific examples include one or more types of light selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, alpha rays, beta rays, and gamma rays, and active electron beams. Among these, ultraviolet light is preferred because it is easy to control the progress of the polymerization reaction and because photopolymerization equipment widely used in this field can be used. It is preferable to select the type of polymerizable liquid crystal compound and photopolymerization initiator contained in the composition so that photopolymerization is possible with ultraviolet light. Furthermore, the polymerization temperature can also be controlled by irradiating the dry coating film with light while cooling it with an appropriate cooling means during polymerization. By employing such cooling methods, polymerization of polymerizable liquid crystal compounds can be carried out at lower temperatures, allowing for the formation of suitable films even when using substrates with relatively low heat resistance. Patterned films can also be obtained by performing masking and development during photopolymerization.

[0107] Examples of the light sources for the active energy rays include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, carbon arc lamps, tungsten lamps, gallium lamps, excimer lasers, LED light sources emitting light in the wavelength range of 380 nm to 440 nm, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, and the like.

[0108] The UV irradiation intensity is typically 10 mW / cm². 2 More than 3,000mW / cm 2 The following may apply: The ultraviolet irradiation intensity is preferably in the wavelength range effective for activating the photopolymerization initiator. The irradiation time is usually 0.1 seconds to 10 minutes, preferably 0.1 seconds to 5 minutes, more preferably 0.1 seconds to 3 minutes, and even more preferably 0.1 seconds to 1 minute. When irradiation is performed once or multiple times at such ultraviolet irradiation intensity, the integrated light dose is 10 mJ / cm². 2 More than 3,000mJ / cm 2 The following is preferable:

[0109] By photopolymerization, the polymerizable liquid crystal compound polymerizes while maintaining the liquid crystal state of the smectic phase, preferably a higher-order smectic phase, thereby forming a film. The film obtained by polymerizing the polymerizable liquid crystal compound while maintaining the liquid crystal state of the smectic phase has the advantage of higher polarization performance compared to conventional host-guest type polarizing films, i.e., films consisting of a liquid crystal state of the nematic phase, due to the action of dichroic dyes. Furthermore, it also has the advantage of superior strength compared to films coated only with dichroic dyes or lyotropic liquid crystals.

[0110] The film thickness can be appropriately selected depending on the applicable display device, and is preferably 0.5 μm to 10 μm, more preferably 1 μm to 5 μm, and even more preferably 1 μm to 3 μm.

[0111] When the film is used as a polarizing film, it is preferable that it be formed on an alignment film. The alignment film has an alignment-regulating force that causes polymerizable liquid crystal compounds and liquid crystalline polymer compounds to liquid crystal orientation in a desired direction. Preferably, the alignment film has solvent resistance so as not to dissolve when a composition containing a liquid crystalline compound, which includes at least one polymerizable liquid crystal compound and a liquid crystalline polymer compound, is applied, and also has heat resistance for solvent removal and heat treatment for orientation of the polymerizable liquid crystal compound. Examples of such alignment films include alignment films containing an oriented polymer, photo-alignment films, and groove-alignment films having an uneven pattern or multiple grooves on their surface, and photo-alignment films are preferred from the viewpoint of accuracy of the orientation angle and quality.

[0112] Laminate The laminate according to this embodiment may comprise a film containing an azo compound represented by formula (1) as a forming material, or a film comprising a composition comprising an azo compound represented by formula (1) and a liquid crystalline compound as a forming material. The laminate may comprise a substrate and a film containing an azo compound represented by formula (1) as a forming material disposed on the substrate, or a substrate, an alignment film disposed on the substrate, and a film comprising an azo compound represented by formula (1) as a forming material disposed on the alignment film. The film containing an azo compound represented by formula (1) as a forming material may constitute a polarizing film. The substrate may also be a phase difference film. The laminate can constitute, for example, a polarizing plate. The laminate can be manufactured, for example, by forming a film on a substrate in accordance with the film manufacturing method described above.

[0113] From the viewpoint of the flexibility and visibility of the display device, the thickness of the laminate is preferably 10 μm to 300 μm, more preferably 20 μm to 200 μm, and even more preferably 25 μm to 100 μm.

[0114] When the laminate includes a phase difference film as a base material, the thickness of the phase difference film can be appropriately selected depending on the display device to which it is applied.

[0115] display device The display device of this embodiment comprises the laminate, which may be a polarizing plate. The display device can be obtained, for example, by bonding the laminate as a polarizing plate to the surface of the display device via an adhesive layer. A display device is a device having a display element and including a light-emitting element or a light-emitting device as a light source. Examples of display devices include liquid crystal displays, organic electroluminescent (EL) displays, inorganic electroluminescent (EL) displays, electron emission displays (e.g., electric field emission displays (FEDs), surface field emission displays (SEDs)), electronic paper (display devices using electronic ink, electrophoretic elements, etc.), plasma displays, projection displays (e.g., grating light bulb (GLV) displays, displays having digital micromirror devices (DMDs)), and piezoelectric ceramic displays. Liquid crystal displays include transmissive liquid crystal displays, semi-transmissive liquid crystal displays, reflective liquid crystal displays, direct-view liquid crystal displays, and projection liquid crystal displays. These display devices may be displays that display two-dimensional images or stereoscopic displays that display three-dimensional images. In particular, organic EL displays and touch panel displays are preferred as display devices, with organic EL displays being especially preferred. [Examples]

[0116] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0117] First, compound (1-1-a) was synthesized by a known diazo coupling method.

[0118] Synthesis Example 1: Synthesis of Azo Compound (1-1) Compound (1-1-a) (0.265 g, 0.570 mmol), N,N-diisopropylcarbodiimide (0.110 g, 8.56 mmol), 4-dimethylaminopyridine (0.011 g, 0.086 mmol), and 2-hexyldecanoic acid (0.220 g, 0.858 mmol) were mixed, dissolved in 5 mL of THF, and stirred at room temperature for 19 hours. An aqueous saturated sodium hydrogen carbonate solution was added to the reaction vessel, and the precipitated solid was filtered off and washed with methanol. The obtained solid was purified by silica gel column chromatography using chloroform as the developing solvent to obtain azo compound (1-1) (0.171 g, yield 43%).

[0119]

Chemical Structure

[0120] Synthesis Example 2: Synthesis of Azo Compound (1-2) Compound (1-1-a) (0.186 g, 0.400 mmol), N,N-diisopropylcarbodiimide (1.01 g, 8.00 mmol), 4-dimethylaminopyridine (0.012 g, 0.098 mmol), and 2-ethylhexanoic acid (0.149 g, 1.03 mmol) were mixed and stirred at room temperature for 15 hours. An aqueous saturated sodium hydrogen carbonate solution was added to the reaction vessel, and the precipitated solid was filtered off and washed with methanol. The obtained solid was purified by silica gel column chromatography using chloroform as the developing solvent to obtain azo compound (1-2) (0.049 g, yield 21%).

[0121]

Chemical Structure

[0122] [ Synthesis Example 3: Synthesis of Compound (1-3) Compound (1-1-a) (3.51 g, 7.55 mmol), pyridine (0.12 g, 1.51 mmol), and acetic anhydride (2.31 g, 22.66 mmol) were mixed and dissolved in 35.1 g of chloroform, and the mixture was stirred at room temperature for 2 days. Saturated sodium bicarbonate aqueous solution was added to the reaction vessel, and the precipitated solid was filtered off and washed with methanol to obtain azo compound (1-3) (1.21 g, yield 32%).

[0123] [ka]

[0124] Example 1: Preparation of Composition E1 Composition E1 was obtained by mixing the following components and stirring at 90°C for 1 hour. ·Azo compound (1-1) 3.96 parts by mass ·Azo compound (1-3) 0.04 part by mass ·Polymerizable liquid crystal compound (A-6) 75 parts by mass ·Polymerizable liquid crystal compound (A-8) 25 parts by mass ·Polymerizable non-liquid crystal compound 5 parts by mass Dipentaerythritol hexaacrylate (Manufactured by Daicel Cytec Co., Ltd.) • Polymerization initiator 6 parts by mass 2-Dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369; manufactured by BASF Japan) • Leveling agent 1.2 parts by mass Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie) • Solvent: Toluene 250 parts by mass

[0125] The structures of the polymerizable liquid crystal compounds are as follows. Polymerizable liquid crystal compounds (A-6) and (A-8) were synthesized using the method described in Lub et al. Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996).

[0126] [ka]

[0127] A polarizing film was formed using the composition E1 obtained above, as described below, to obtain a laminate.

[0128] Formation of polarizing film A photo-alignment film-forming composition was applied to a glass substrate and dried at 120°C to obtain a dried coating. This dried coating was irradiated with polarized UV light to form a photo-alignment film, and a glass with a photo-alignment film was obtained. Polarized UV irradiation was performed using a UV irradiation device (SPOT CURE SP-7; Ushio Inc.) under conditions where the intensity measured at a wavelength of 365 nm was 100 mJ.

[0129] Composition E1 was applied to a photo-aligned glass by spin coating, heated and dried on a 120°C hot plate for 1 minute, and then rapidly cooled to room temperature to form a dry coating on the alignment film. Next, ultraviolet light was applied using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Inc.) at an exposure dose of 2000 mJ / cm². 2 By irradiating with a 313nm wavelength (based on 313nm), polymerizable liquid crystal compounds contained in the dried coating film were polymerized to form a polarizing film from the dried coating film, and a laminate was obtained. The thickness of the polarizing film at this time was measured using a laser microscope (OLS3000 manufactured by Olympus Corporation) and was found to be 1.8 μm.

[0130] Example 2: Preparation of Composition E2 Composition E2 was obtained in the same manner as in Example 1, except that 3.80 parts by mass of azo compound (1-1) and 0.20 parts by mass of azo compound (1-3) were used. A polarizing film was formed using the obtained composition E2 in the same manner as above to obtain a laminate.

[0131] Example 3: Preparation of Composition E3 Composition E3 was obtained in the same manner as in Example 1, except that 3.60 parts by mass of azo compound (1-1) and 0.40 parts by mass of azo compound (1-3) were used. A polarizing film was formed using the obtained composition E3 in the same manner as above to obtain a laminate.

[0132] Example 4: Preparation of Composition E4 Composition E4 was obtained in the same manner as in Example 1, except that 3.10 parts by mass of azo compound (1-1), 0.70 parts by mass of azo compound (1-2), and 0.20 parts by mass of azo compound (1-3) were used. A polarizing film was formed in the same manner as above using the obtained Composition E4 to obtain a laminate.

[0133] Example 5: Preparation of Composition E5 Composition E5 was obtained in the same manner as in Example 1, except that 0.70 parts by mass of azo compound (1-1), 3.10 parts by mass of azo compound (1-2), and 0.20 parts by mass of azo compound (1-3) were used. A polarizing film was formed in the same manner as above using the obtained Composition E5 to obtain a laminate.

[0134] Comparative Example 1: Preparation of Composition C1 Composition C1 was obtained in the same manner as in Example 1, except that 4.00 parts by mass of azo compound (1-1), 0.00 parts by mass of azo compound (1-2), and 0.00 parts by mass of azo compound (1-3) were used. A polarizing film was formed in the same manner as above using the obtained Composition C1 to obtain a laminate.

[0135] Comparative Example 2: Preparation of Composition C2 Composition C2 was obtained in the same manner as in Example 1, except that 0.00 parts by mass of azo compound (1-1), 4.00 parts by mass of azo compound (1-2), and 0.00 parts by mass of azo compound (i-3) were used. A polarizing film was formed in the same manner as above using the obtained Composition C2 to obtain a laminate.

[0136] Comparative Example 3: Preparation of Composition C3 Composition C3 was obtained in the same manner as in Example 1, except that 0.00 parts by mass of azo compound (1-1), 0.00 parts by mass of azo compound (1-2), and 4.00 parts by mass of azo compound (1-3) were used. A polarizing film was formed in the same manner as above using the obtained Composition C3 to obtain a laminate.

[0137] Comparative Example 4: Preparation of Composition C4 Composition C4 was obtained in the same manner as in Example 1, except that 2.00 parts by mass of azo compound (1-1), 2.00 parts by mass of azo compound (1-2), and 0.00 parts by mass of azo compound (1-3) were used. A polarizing film was formed using the obtained composition C4 in the same manner as above to obtain a laminate.

[0138] Comparative Example 5: Preparation of Composition C5 Composition C5 was obtained in the same manner as in Example 1, except that 0.00 parts by mass of azo compound (1-1), 3.80 parts by mass of azo compound (1-2), and 0.20 parts by mass of azo compound (1-3) were used. A polarizing film was formed using the obtained composition C5 in the same manner as above to obtain a laminate.

[0139] Calculation of various parameters 1-1. Calculation of Hansen Solubility Parameter (HSP) The dispersion term (δD), polarity term (δP), and hydrogen bonding term (δH) in the Hansen solubility parameter (HSP) of the azo compound represented by equation (1) were calculated using the Y-MB method with HSP calculation software (HSPiP).

[0140] 1-2. Calculation of the difference in Hansen solubility parameters (HSP) Among the azo compounds contained in dichroic dyes, the dispersion term of the azo compound whose dispersion term in the Hansen solubility parameter (HSP) is maximized is δD. max The dispersion term of the azo compound that minimizes the dispersion term is δD min The polar term of the azo compound that maximizes the polar term is δP max The polarity term of the azo compound that minimizes the polarity term is δP min The hydrogen bonding term of the azo compound with the largest hydrogen bonding term is δH max The hydrogen bonding term of the azo compound that minimizes the hydrogen bonding term is δH min Let the difference in the variance term be δD d , polarity difference rate δP d , difference in hydrogen bonding term δH d These were calculated using the following formulas (7), (8), and (9). δD d =(δD max -δDmin ) / δD max (7) Erotica P d =(δP max -δP min ) / δP max (8) δH d =(δH max -δH min ) / δH max (9)

[0141] 1-3. Calculation of the weighted average of Hansen solubility parameters (HSP) The dispersion term of the azo compound (1-A) represented by formula (1) contained in the dichroic dye is δD 1-A , the polarity term is δP 1-A , the hydrogen bond term is δH 1-A The dispersion term of the azo compound (1-B) is δD 1-B , the polarity term is δP 1-B , the hydrogen bond term is δH 1-B The dispersion term for the azo compound (1-C) is δD 1-C , the polarity term is δP 1-C , the hydrogen bond term is δH 1-C The ratio of azo compound (1-A) to the total mass of azo compounds represented by formula (1) contained in the dichroic dye is R 1-A The ratio of azo compounds (1-B) is R 1-B The ratio of azo compounds (1-C) is R 1-C Let the weighted average of the variance terms be δD a , weighted average of polarity terms δP a , weighted average δH of hydrogen bonding terms a These were calculated using the following formulas (10), (11), and (12), respectively. δD a = δD 1-A ×R 1-A +δD 1-B ×R 1-B +δD 1-C ×R 1-C (10) Erotica P a = δP 1-A ×R 1-A +δP 1-B ×R 1-B +δP 1-C ×R1-C (11) δH a = δH 1-A ×R 1-A +δH 1-B ×R 1-B +δH 1-C ×R 1-C (12)

[0142] 2-1. Calculation of CLogP The CLogP values ​​of the azo compounds represented by equation (1) were calculated using ChemDraw ver.22 (software from PerkinElmer).

[0143] 2-2. Difference rate of CLogP (CLogP d Calculation of ) Among the azo compounds represented by formula (1) included in dichroic dyes, the CLogP of the azo compound with the highest CLogP is defined as CLogP. max The CLogP of the azo compound that minimizes CLogP is determined by CLogP. min The difference rate of CLogP (CLogP d ) was calculated using the following formula (13). CLogP d =(CLogP max -CLogP min ) / CLogP max (13)

[0144] 2-3. Weighted average of CLogP (CLogP a Calculation of ) The CLogP of the azo compound (1-A) represented by formula (1) contained in the dichroic dye is CLogP 1-A , CLogP of azo compound (1-B) CLogP 1-B , CLogP of azo compound (1-C) 1-C The ratio of azo compound (1-A) to the total mass of azo compounds represented by formula (1) contained in the dichroic dye is R 1-A The ratio of azo compounds (1-B) is R 1-B The ratio of azo compounds (1-C) is R 1-CLet's use the weighted average of CLogP (CLogP a ) was calculated using the following formula (14). CLogP a = CLogP 1-A ×R 1-A +CLogP 1-B ×R 1-B +CLogP 1-C ×R 1-C (14)

[0145] 3-1. Calculation of the transition dipole moment ratio (D) The transition dipole moment ratio (D) of the azo compound represented by equation (1) was calculated using Gaussian16 (software from Gaussian, Inc.), with B3LYP as the functional and 6-31g(d) as the basis set, followed by TD-DFT calculation after structural optimization. The Ar of the azo compound represented by the structurally optimized formula (1) 1 The atoms in L that are directly bonded, and Ar 3 The long axis of the molecule was defined as the straight line connecting the nitrogen atoms, excluding the azo group directly bonded to it. The transition dipole moment ratio (D) was calculated from the angle θ between the long axis of the molecule and the transition dipole moment of the transition at which the oscillator intensity is maximum, using the following equation (15). D = |1 / tanθ| (15)

[0146] 3-2. Difference ratio of transition dipole moment ratio (D d Calculation of ) Among the azo compounds represented by formula (1) included in dichroic dyes, the transition dipole moment ratio (D) of the azo compound with the maximum transition dipole moment ratio (D) is defined as D. max The transition dipole moment ratio of the azo compound that minimizes the transition dipole moment ratio is D. min Let D be the difference in the transition dipole moment ratio. d ) was calculated using the following formula (16). D d =(D max -D min ) / Dmax (16)

[0147] 3-3. Weighted average of transition dipole moment ratios (D a Calculation of ) The transition dipole moment ratio of the azo compound (1-A) represented by formula (1) in the dichroic dye is D. 1-A The transition dipole moment ratio of the azo compound (1-B) is D 1-B The transition dipole moment ratio of the azo compound (1-C) is D 1-C The ratio of azo compound (1-A) to the total mass of azo compounds represented by formula (1) contained in the dichroic dye is R 1-A The ratio of azo compounds (1-B) is R 1-B The ratio of azo compounds (1-C) is R 1-C Let the weighted average of the transition dipole moment ratios (D a ) was calculated using the following formula (17). D a = D 1-A ×R 1-A +D 1-B ×R 1-B +D 1-C ×R 1-C (17)

[0148] evaluation 1. Filterability of the composition The filtration properties of the compositions prepared as described above were evaluated as follows: A PTFE filter with a mesh size of 0.2 μm and a diameter of 25 mm was placed in a 3 mL disposable syringe, 2 mL of the composition was introduced, and a constant pressure of 300 kPa was applied to the syringe to evaluate the filtration properties of the composition. The results are shown in Table 1. If the filtration time for 2 mL is 10 seconds or less, the composition is judged to have high uniformity and good filtration properties.

[0149] 2. Stability of the composition over time The compositions prepared above were coated onto photo-aligned glass using a spin-coating method, left at room temperature without heating and drying, and their stability over time was evaluated. The results are shown in Table 1. Note that the aggregates formed on the coated surface after 24 hours were measured at 1 cm². 2If the average number of particles per unit is one or less, the composition is judged to have good long-term stability.

[0150] [Table 1]

[0151] Table 1 shows that dichroic dyes containing two or more azo compounds in which the ratio of each HSP component is above a certain value exhibit good filterability before coating and good stability over time after coating, and can improve the productivity and quality of polarizing plates having a film formed from the composition.

Claims

1. A dichroic dye containing at least two or more azo compounds represented by the following formula (1), among the azo compounds contained in the dichroic dye, the dispersion term of the azo compound having the maximum dispersion term in the Hansen solubility parameter (HSP) is δD ｍａｘ , the dispersion term of the azo compound having the minimum dispersion term is δD ｍｉｎ , the polar term of the azo compound having the maximum polar term is δP ｍａｘ , the polar term of the azo compound having the minimum polar term is δP ｍｉｎ , the hydrogen bond term of the azo compound having the maximum hydrogen bond term is δH ｍａｘ , the hydrogen bond term of the azo compound having the minimum hydrogen bond term is δH ｍｉｎ When it is set as such, the difference rate of the dispersion term δD ｄ , the difference rate of the polar term δP ｄ , the difference rate of the hydrogen bond term δH ｄ are dichroic dyes that simultaneously satisfy the following formulas (2), (3), and (4). 【Chemistry 1】 δD ｄ =(δD ｍａｘ -δD ｍｉｎ ) / δD ｍａｘ ≧ 0.04 (2) δP ｄ =(δP ｍａｘ -δP ｍｉｎ ) / δP ｍａｘ ≧ 0.20 (3) δH ｄ =(δH ｍａｘ -δH ｍｉｎ ) / δH ｍａｘ ≧ 0.20 (4) In formula (1), Ar １ Ar ２ and Ar ３ Each independently represents a substituted 1,4-phenylene group, a 1,4-naphthylene group, or a divalent heterocyclic group, and Ar １ Ar ２ and Ar ３ At least one of these represents a divalent heterocyclic group formed by the condensation of two sulfur-containing aromatic rings, which may have substituents. R ２ and R ３ Each of these independently represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms, which may have substituents. ２ and R ３ They may be linked to each other to form an aliphatic ring, R ２ or R ３ A portion of the methylene group constituting the aliphatic hydrocarbon group represented by may be substituted with an oxygen atom or a carbonyl group. R Ｓ R represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, which may have a hydrogen atom or substituents. Ｌ It may have hydrogen atoms or substituents, and has a number of carbon atoms R Ｓ This represents an aliphatic hydrocarbon group with the same or more carbon atoms as the given carbon atom. R ２ , R ３ , R Ｓ and R Ｌ At least one selected from the group consisting of the above may have a polymerizable group. L represents a linking group formed from at least one selected from the group consisting of -O-, -S-, -C(=O)-, and linear or branched alkylene groups having 1 to 4 carbon atoms. k represents 1 or 2, and if k is 2, then two Ar ２ These may be the same or different.

2. The weighted average of the CLogP of the azo compound contained in the aforementioned dichroic dye is CLogP ａ In that case, the dichroic dye according to claim 1 satisfies the following formula (5). CLogP ａ ≧ 11.0 (5)

3. Among the azo compounds included in the aforementioned dichroic dye, the transition dipole moment ratio (D) of the azo compound with the maximum transition dipole moment ratio (D) is determined as D ｍａｘ The transition dipole moment ratio of the azo compound that minimizes the transition dipole moment ratio is D. ｍｉｎ In this case, the difference in the transition dipole moment ratio D ｄ The dichroic dye according to claim 1, wherein the following formula (6) is satisfied. D ｄ =(D ｍａｘ -D ｍｉｎ ) / D ｍａｘ ≧ 0.05 (6)

4. In formula (1) above, L is represented by the following formula (1a), the dichroic dye according to claim 1. 【Chemistry 2】 In formula (1a), R ４ Each of these independently represents either a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. P and Q independently represent a single bond, -O-, -OC(=O)-, -C(=O)O-, or -S-. x and y each represent a number from 0 to 4 independently. * indicates the joining position.

5. In formula (1) above, Ar １ and Ar ３ The dichroic dye according to claim 1, wherein is a 1,4-phenylene group which may have a substituent.

6. In formula (1) above, Ar ２ The dichroic dye according to claim 1, wherein k represents a thieno[3,2-d]thiazolediyl group or thieno[3,2-d]thiophenediyl group which may have substituents, and k is 1.

7. A composition comprising a dichroic dye according to any one of claims 1 to 6, and a liquid crystalline compound comprising at least one polymerizable liquid crystal compound and a liquid crystalline polymer compound.

8. The composition according to claim 7, wherein the liquid crystalline compound is a smectic liquid crystalline compound.

9. A film formed using the composition described in claim 7 as the forming material.

10. A laminate comprising the film described in claim 9.

11. A display device comprising the film described in claim 9.

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