Azo compound, composition, membrane, laminate and display device

Abstract

To provide an azo compound which suppresses occurrence of irregularity in a polarizing film due to a difference in absorbance in the plane of the polarizing film formed.SOLUTION: Provided is an azo compound represented by the following formula (1), where Ar1, Ar2 and Ar3 each independently represent 1,4-phenylene group, 1,4-naphthylene group or a bivalent heterocyclic group, which may have a substituent; R2 and R3 each independently represent a C1-10 aliphatic hydrocarbon group which may have a substituent, where they may be linked to each other to form an aliphatic ring and a part of methylene groups may be substituted with an oxygen atom or a carbonyl group; RS represents a C4-12 aliphatic hydrocarbon group; RL represents an aliphatic hydrocarbon group having a carbon number which is larger than that of the RS; L represents a linking group formed by at least one selected from the group consisting of -O-, -S-, -C(=O)- and linear or a branched C1-4 linear or branched-chain alkylene group; and k represents 1 or 2.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an azo compound, a composition, a film, a laminate and a display device. [Background technology]

[0002] A polarizing film made of a composition containing a dichroic dye is known as a polarizing film (optical film) used in liquid crystal displays, etc. As such a dichroic dye, 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] Patent Publication No. 2022-88325 Summary of the Invention [Problem to be solved by the invention]

[0005] When a polarizing film prepared using the dichroic dye represented by the above formula was examined after film formation, unevenness due to differences in in-plane absorbance was sometimes visible. The object of the present invention is to provide an azo compound that suppresses the occurrence of unevenness after film formation, a composition containing the azo compound, a film formed from the composition, a laminate including the film, and a display device including the laminate. [Means for solving the problem]

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

[10] . [1] A compound represented by the following formula (1): [ka] In formula (1), Ar 1 , Ar 2 and Ar 3 each independently represents a 1,4-phenylene group, a 1,4-naphthylene group, or a divalent heterocyclic group, each of which may have a substituent; Ar 1 , Ar 2 and Ar 3 At least one of these represents a divalent heterocyclic group formed by condensing two sulfur-containing aromatic rings and which may have a substituent. R 2 and R 3 R each independently represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms which may have a substituent. 2 and R 3 may be linked together to form an aliphatic ring, R 2 or R 3 A part of the methylene groups constituting the aliphatic hydrocarbon group represented by the following formula may be substituted with an oxygen atom or a carbonyl group. R S R represents an aliphatic hydrocarbon group having 4 to 12 carbon atoms which may have a substituent. L may have a substituent, the number of carbon atoms is R S represents an aliphatic hydrocarbon group having more carbon atoms than R 2 , R 3 , R S and R L At least one selected from the group consisting of 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 a linear or branched alkylene group having 1 to 4 carbon atoms. k represents 1 or 2. When k is 2, two Ar 2 may be the same or different. [2] The compound according to [1], wherein in the formula (1), L is represented by the following formula (1a): [ka] In formula (1a), R 4each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. P and Q each independently represent a single bond, -O-, -OC(=O)-, -C(=O)O- or -S-. x and y each independently represent a number from 0 to 4. * represents a bonding position. [3] In the formula (1), Ar 1 and Ar 3 represents an optionally substituted 1,4-phenylene group. [4] In the formula (1), Ar 2 represents an optionally substituted thieno[3,2-d]thiazolediyl group or thieno[3,2-d]thiophenediyl group, and k is 1. [5] A composition comprising the azo compound according to any one of [1] to [4] and a liquid crystal compound comprising at least one of a polymerizable liquid crystal compound and a liquid crystal polymer compound. [6] The composition according to [5], wherein the liquid crystal compound is a smectic liquid crystal compound. [7] A film formed from the composition according to [5] or [6]. [8] A laminate comprising the film according to [7]. [9] A display device comprising the film described in [7] or the laminate described in claim 8. Effect of the Invention

[0007] According to the present invention, it is possible to provide an azo compound that suppresses the occurrence of unevenness after film formation, a composition containing the same, a film formed from the composition, a laminate including the film, and a display device including the laminate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In this specification, the term "step" includes not only an independent step, but also a step that cannot be clearly distinguished from other steps, as long as the intended purpose of the step is achieved. Furthermore, the content of each component in the composition means the total amount of the multiple substances present in the composition when multiple substances corresponding to each component are present in the composition, unless otherwise specified. Furthermore, the upper and lower limits of the numerical ranges described in this specification can be arbitrarily selected and combined from the numerical values ​​exemplified as the numerical ranges. Hereinafter, the embodiments of the present invention will be described in detail. Note that the scope of the present invention is not limited to the embodiments described here, and various modifications can be made within the scope that does not impair the spirit of the present invention.

[0009] Azo compound An 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. In the azo compound represented by formula (1), for example, the aliphatic hydrocarbon group linked to L has a long chain structure, which is considered to strengthen the interaction with the side chains of the liquid crystal molecules constituting the polarizing film. In addition, it is considered that the asymmetric branched chain structure can maintain the liquid crystal state in a good 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 the presence of aliphatic hydrocarbon chains of different lengths helps maintain the liquid crystal state in a good condition during the cooling process of the coating film. These actions are believed to suppress the occurrence of unevenness after the formation of the polarizing film.

[0010] [ka]

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

[0012] Ar 1may preferably represent an optionally substituted 1,4-phenylene group or an optionally substituted divalent heterocyclic group, or may represent an optionally substituted 1,4-phenylene group. 3 may preferably represent a 1,4-phenylene group which may have a substituent.

[0013] Ar 2 may represent a divalent heterocyclic group which may have a substituent, or may represent a divalent heterocyclic group which is formed by condensing two sulfur-containing aromatic rings and which may have a substituent. Ar 2 The heterocyclic group represented by the formula (I) may be formed by removing two hydrogen atoms from an aromatic condensed heterocyclic compound in which two 5-membered sulfur-containing aromatic heterocyclic compounds are condensed. Examples of the 5-membered sulfur-containing aromatic heterocyclic compound include thiophene and thiazole. Specific examples of the heterocyclic group formed by condensing two sulfur-containing aromatic rings include a thieno[3,2-d]thiazolediyl group, a thieno[3,2-d]thiophenediyl group, and a thiazolo[5,4-d]thiazolediyl group, and may contain at least one selected from the group consisting of these. The heterocyclic group formed by condensing two sulfur-containing aromatic rings may preferably contain at least one selected from the group consisting of a thieno[3,2-d]thiazolediyl group and a thieno[3,2-d]thiophenediyl group.

[0014] Ar 1 , Ar 2 and Ar 3 The substituent in may include at least one selected from the group consisting of a halogen atom, a hydroxy group, an alkyl group having 1 to 3 carbon atoms, and an alkoxy group having 1 to 3 carbon atoms, preferably at least one selected from the group consisting of a halogen atom, a hydroxy group, a methyl group, and a methoxy group, more preferably at least one selected from the group consisting of a fluorine atom, a chlorine atom, a hydroxy group, a methyl group, and a methoxy group. 1 , Ar 2 and Ar 3The number of substituents in each may be independently, for example, 0, 1 or 2, and preferably 0 or 1.

[0015] k may be 1 or 2, preferably 1. When k is 2, two Ar 2 may be the same or different.

[0016] R 2 and R 3 R each independently represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms which may have a substituent. The number of carbon atoms in the aliphatic hydrocarbon group may be preferably 1 to 8, or 1 to 6. The aliphatic hydrocarbon group may be either 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 together to form an aliphatic ring, R 2 or R 3 A part of the methylene groups constituting the aliphatic hydrocarbon group represented by the formula (I) may be substituted with an oxygen atom or a carbonyl group. The ring formed may be a nitrogen-containing aliphatic ring, and the number of members may be, for example, 5 or 6. 2 and R 3 Examples of the ring formed by bonding with each other include a pyrrolidyl group, a piperidyl group, an oxazolidinyl group, and a morpholyl group.

[0017] R S R represents an aliphatic hydrocarbon group having 4 to 12 carbon atoms which may have a substituent. S The number of carbon atoms in the aliphatic hydrocarbon group represented by the formula (I) may be preferably 4 or more and 8 or less, more preferably 4 or more and 6 or less. L represents an aliphatic hydrocarbon group which may have a substituent, R L The number of carbon atoms in R S The number of carbon atoms is greater than that of R. LThe number of carbon atoms in the aliphatic hydrocarbon group represented by the formula (I) may be preferably 6 or more and 14 or less, and more preferably 6 or more and 8 or less. L The number of carbon atoms and R S The difference in the number of carbon atoms between R and R may be, for example, 1 or more and 10 or less, and preferably 2 or more and 6 or less. L The number of carbon atoms and R S The sum of the carbon numbers of R may be, for example, 10 or more and 26 or less, and preferably 10 or more and 14 or less. L The number of carbon atoms and R S The difference in the number of carbon atoms between R S When the number of carbon atoms is within the above range, the disorder of the alignment of the liquid crystal is more effectively suppressed, and thus the occurrence of unevenness after film formation is more effectively suppressed, and a better dichroic ratio can be achieved.

[0018] R S or R L The aliphatic hydrocarbon group represented by the formula (I) may be either branched or linear, preferably linear. Examples of the aliphatic hydrocarbon group include an alkyl group, an alkenyl group, and an alkynyl group, 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, and an epoxy group. The polymerizable group may be, for example, a radical polymerizable group, and may preferably be a (meth)acrylate group. R 2 , R 3 , R S and R L The total number of polymerizable groups contained in may be, for example, 1 or 2, and preferably 1.

[0020] L represents a linking group formed of at least one selected from the group consisting of -O-, -S-, -C(=O)-, and a linear or branched alkylene group having 1 to 4 carbon atoms. From the viewpoint of the stability of the compound, it is preferable that the linking group represented by L is selected so as not to contain an oxygen-oxygen bond, a sulfur-sulfur bond, or an oxygen-sulfur bond. When L contains multiple alkylene groups, they may be different from each other or the same. Specific examples of the divalent group represented by L include an alkylene group, an alkyleneoxy group, an alkyleneoxycarbonyl group, an alkylenecarbonyloxy group, an alkylenecarbonyl group, an oxyalkylene group, an oxycarbonylalkylene group, a carbonyloxyalkylene group, a carbonylalkylene group, a carbonylalkyleneoxy group, an alkyleneoxyalkylene group, a carbonyloxyalkyleneoxy group, a carbonyloxyalkyleneoxyalkylene group, a carbonylalkyleneoxy group, a carbonylalkyleneoxyalkylene group, an alkylenesulfanyl group, a sulfanylalkylene group, an alkylenesulfanylalkylene group, and a carbonyloxyalkylenesulfanyl group. Of the carbon atoms constituting L, the total number of carbon atoms other than the carbonyl carbon may be, for example, 1 to 8, and 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 R each 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 the formula (I) is preferably 1 to 2, or may be 1. Two R 4At least one of them may be a hydrogen atom, or both may be hydrogen atoms. P and Q each independently represent a single bond, -O-, -OC(=O)-, -C(=O)O-, or -S-. x and y each 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, and preferably 1 to 6, 1 to 4, or 1 to 3. * represents a bonding position.

[0023] Specific examples of the azo compound represented by formula (1) include azo compounds represented by the following formulas (1-1) to (1-32), but the present invention is not limited to these.

[0024] [ka]

[0025] From the viewpoint of suppressing unevenness during coating film formation, the azo compound represented by formula (1) preferably contains at least one selected from the group consisting of azo compounds represented by any one of formulas (1-1) to (1-32).

[0026] Method for producing azo compounds The azo compound represented by formula (1) can be produced by appropriately applying a conventionally known synthesis method. Specifically, for example, the production method described in JP-A-2022-088325 can be referred to.

[0027] Dichroic dyes The dichroic dye contains an azo compound represented by formula (1) as an active ingredient. The dichroic dye contains an azo compound represented by formula (1), and thus the formation of a polarizing film can suppress the occurrence of unevenness due to an in-plane absorbance difference. The dichroic dye may contain a combination of two or more azo compounds represented by formula (1) having different structures. When the dichroic dye contains two or more azo compounds represented by formula (1), they may have different maximum absorption wavelengths. Furthermore, the dichroic dye may contain other dye compounds in addition to the azo compound represented by formula (1).

[0028] composition The composition of the present embodiment includes at least one azo compound represented by formula (1) and a liquid crystal compound including at least one of a polymerizable liquid crystal compound and a liquid crystal 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 by using the composition as a material for forming the polarizing film is a high-quality polarizing film that suppresses the occurrence of unevenness caused by an in-plane absorbance difference and exhibits a good dichroic ratio.

[0029] The content of the azo compound represented by formula (1) in the composition may be, for example, 50 parts by mass or less, preferably 0.1 parts by mass or more and 10 parts by mass or less, or 0.1 parts by mass or more and 5 parts by mass or less, relative to 100 parts by mass of the solid content of the composition. If it is within the above range, the azo compound represented by formula (1) can be sufficiently dispersed. In this specification, the solid content refers to the total amount of components excluding volatile components such as solvents from the composition. The composition may contain only one type of azo compound represented by formula (1), or may contain two or more types of azo compounds having different structures in combination. When the composition contains two or more types of azo compounds, they may have different maximum absorption wavelengths.

[0030] The composition may further contain at least one other dye compound, such as a dichroic dye, other than the azo compound represented by formula (1). Examples of the other dye compounds include azo dyes such as monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, and stilbene azo dyes, and at least one selected from the group consisting of these is preferable. The composition may contain one other dye compound alone, or may contain two or more in combination. For example, when used as a coating-type polarizing plate material, it is preferable that the other dye compound contained in the composition has a maximum absorption wavelength in a wavelength range different from that of the compound represented by formula (1). For example, when used as a coating-type polarizing plate material, the composition preferably contains three or more dichroic dyes in combination, including the compound represented by formula (1), and more preferably contains three or more azo dyes in combination. When the composition contains three or more dye compounds in combination with different maximum absorption wavelengths, for example, absorption can be obtained in the entire visible light range by a film formed from the composition.

[0031] When the composition contains other dye compounds, the content thereof may be, for example, 50 parts by mass or less, and preferably 0.1 parts by mass or more and 10 parts by mass or less, or 0.1 parts by mass or more and 5 parts by mass or less, relative to 100 parts by mass of the solid content of the composition. If it is within the above range, the other dye compounds can be sufficiently dispersed.

[0032] The composition contains a liquid crystal compound including at least one of a polymerizable liquid crystal compound and a liquid crystal polymer compound in addition to the azo compound represented by formula (1). The composition may contain both a polymerizable liquid crystal compound and a liquid crystal polymer compound, and the polymerizable liquid crystal compound and the liquid crystal polymer compound contained in the composition may each be two or more kinds. By containing at least one of a polymerizable liquid crystal compound and a liquid crystal polymer compound, a composition in which the compound represented by formula (1) is dispersed in the liquid crystal compound can be formed.

[0033] The liquid crystalline polymer compound may be a thermotropic liquid crystal polymer or a lyotropic liquid crystal polymer. The liquid crystalline polymer compound is preferably a thermotropic liquid crystal polymer, since it allows precise control of the film thickness.

[0034] Liquid crystals are classified into smectic liquid crystals, nematic liquid crystals, and cholesteric liquid crystals according to the molecular arrangement structure in the liquid crystal state. Among them, smectic liquid crystals are preferably used for polarizing film applications. Therefore, the polymerizable liquid crystal compound is preferably a polymerizable smectic liquid crystal compound, and the liquid crystalline polymer compound is preferably a smectic liquid crystalline polymer compound.

[0035] By using a polymerizable liquid crystal compound exhibiting smectic liquid crystallinity and a polymer compound exhibiting smectic liquid crystallinity, a polarizing film with a high degree of orientation order can be formed. The liquid crystal state exhibited by the polymerizable liquid crystal compound and the liquid crystal polymer compound is preferably a smectic phase (smectic liquid crystal state), and more preferably a high-order smectic phase (high-order smectic liquid crystal state) from the viewpoint of realizing a higher degree of orientation order. Here, the high-order smectic phase means a smectic B phase, a smectic D phase, a smectic E phase, a smectic F phase, a smectic G phase, a smectic H phase, a smectic I phase, a smectic J phase, a smectic K phase, and a smectic L phase, and among these, the smectic B phase, the smectic F phase, and the smectic I phase are more preferable. A polarizing film with a high degree of orientation order can obtain Bragg peaks derived from a high-order structure such as a hexatic phase and a crystal phase in X-ray diffraction measurement. The Bragg peak means 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 crystal polymer compound may be a polymerizable smectic liquid crystal compound or a smectic liquid crystal polymer compound that shows a Bragg peak derived from a higher order structure in X-ray diffraction measurement.

[0036] The compound represented by formula (1) can exhibit high dichroism even when dispersed among dense molecular chains formed from at least one compound of a smectic liquid crystal polymerizable liquid crystal compound and a smectic liquid crystal polymer compound. Therefore, a liquid crystal compound containing at least one of a polymerizable liquid crystal compound and a liquid crystal polymer compound, particularly a liquid crystal compound containing at least one of a smectic liquid crystal polymerizable liquid crystal compound and a smectic liquid crystal polymer compound, and a composition containing the compound represented by formula (1) can provide a polarizing film having a high dichroic ratio in which the occurrence of unevenness due to an in-plane absorbance difference is suppressed in the formed polarizing film.

[0037] The polymerizable liquid crystal compound is a compound that has at least one polymerizable group in the molecule and can show a liquid crystal phase by being aligned. The polymerizable liquid crystal compound is preferably a compound that can show a liquid crystal phase by being aligned alone. The polymerizable group means a functional group that can be involved in a polymerization reaction, and is preferably a radical polymerizable group.

[0038] Specific examples of the polymerizable liquid crystal compound include compounds 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)

[0039] In formula (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 may be the same or different. X 1 , X 2 and X3 At least three selected from the group consisting of Y represent a divalent 6-membered hydrocarbon ring group. 1 , Y 2 , W 1 and W 2 each independently represents a single bond or a divalent linking group. When m is 2 or 3, Y 1 may be the same or different. 1 and V 2 each independently represents an alkanediyl group having 1 to 20 carbon atoms which may have a substituent. At least one of -CH2- constituting the alkanediyl group may be substituted with -O-, -CO-, -S- or -NH-. 1 and U 2 each independently represents a polymerizable group or a hydrogen atom, and at least one of them represents a polymerizable group.

[0040] X 1 , X 2 and X 3 In the above, examples of the divalent aromatic group include a 1,4-phenylene group and a 1,4-naphthylene group. Examples of the divalent alicyclic hydrocarbon group include a cyclohexane-1,4-diyl group. 1 , X 2 and X 3 At least one of the divalent aromatic group and the divalent alicyclic hydrocarbon group in the formula (I) may have a substituent. Examples of the substituent include an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, or an n-butyl group, a cyano group, or a halogen atom. At least one of the -CH2- groups constituting the divalent alicyclic hydrocarbon group may be substituted with -O-, -S-, or -NR-. Here, R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group.

[0041] X 1 , X 2 and X 3 Examples of the divalent 6-membered hydrocarbon ring group in include an optionally substituted 1,4-phenylene group and an optionally substituted cyclohexane-1,4-diyl group.

[0042] X 1 , X 2 and X 3 The divalent aromatic group in is preferably a 1,4-phenylene group which may have a substituent, more preferably an unsubstituted 1,4-phenylene group, and the divalent alicyclic hydrocarbon group is preferably a cyclohexane-1,4-diyl group which may have a substituent, more preferably a trans-cyclohexane-1,4-diyl group which may have a substituent, and even more preferably an unsubstituted trans-cyclohexane-1,4-diyl group.

[0043] Y 1 and Y 2 each independently represents a single bond or a divalent linking group. Examples of the divalent linking group include -CH2CH2-, -CHO-, -(C=O)O-, -O(C=O)O-, -N=N-, -CR a =CR b -, -C≡C- and -CR a ═N-, where R a and R b Each of Y independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. 1 is preferably -CH2CH2-, -(C=O)O- or a single bond. 2 is preferably -CH2CH2- or -CH2O-.

[0044] W 1 and W 2 Each of W independently represents a single bond or a divalent linking group. The 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 are each independently preferably a single bond or -O-.

[0045] V 1 and V 2each independently represents an alkanediyl group having 1 to 20 carbon atoms which may have a substituent. At least one of -CH2- constituting the alkanediyl group may be replaced by -O-, -CO-, -S- or -NH-.

[0046] V 1 and V 2 Examples of the alkanediyl group represented by the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a decane-1,10-diyl group, a tetradecane-1,1-diyl group, and an icosane-1,20-diyl group. 1 and V 2 is preferably an alkanediyl group having 2 to 12 carbon atoms, and more preferably an alkanediyl group having 6 to 12 carbon atoms.

[0047] Examples of the substituent that the optionally substituted alkanediyl group having 1 to 20 carbon atoms may have include a cyano group and a halogen atom. The alkanediyl group is preferably an alkanediyl group having no substituent, and more preferably an alkanediyl group having no substituent and being linear.

[0048] U 1 and U 2 each independently represents a polymerizable group or a hydrogen atom, and at least one of them represents a polymerizable group. 1 and U 2 is preferably a polymerizable group. 1 and U 2 Preferably, both of U are polymerizable groups, and preferably both are radically polymerizable groups. 1 and a polymerizable group represented by U 2 The polymerizable groups represented by U may be different from each other, but are preferably the same type of group. 1 and U 2Examples of the polymerizable group in the polymerizable liquid crystal compound include the same polymerizable groups as those exemplified above. 1 and U 2 The polymerizable group represented by the formula (I) is preferably at least one selected from the group consisting of a vinyloxy group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, and an oxetanyl group, and more preferably an acryloyloxy group.

[0049] Specific examples of the polymerizable liquid crystal compound (A) include compounds represented by the following formulae (A-1) to (A-17). When the polymerizable liquid crystal compound (A) has a cyclohexane-1,4-diyl group, the cyclohexane-1,4-diyl group is preferably a trans type.

[0050] [ka]

[0051] [ka]

[0052] [ka]

[0053] Among them, the polymerizable liquid crystal compound (A) is preferably at least one selected from the group consisting of compounds represented by any of 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.

[0054] The polymerizable liquid crystal compound (A) can be produced by the method described in the known documents such as Lub et al. Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996) and Japanese Patent No. 4719156.

[0055] 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 may be another liquid crystalline polymer compound, and is preferably a polymer of the polymerizable liquid crystal compound.

[0056] The polymer of the polymerizable liquid crystal compound may use two or more of the polymerizable liquid crystal compounds as raw material monomers. The polymer of the polymerizable liquid crystal compound may also contain a monomer other than the polymerizable liquid crystal compound as a raw material monomer.

[0057] The content of the polymerizable liquid crystal compound in the polymer of the polymerizable liquid crystal compound is usually 1 mol % or more and 100 mol % or less, based on the total amount of structural 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 polymer of the polymerizable liquid crystal compound, the content is preferably 30 mol % or more and 100 mol % or less, more preferably 50 mol % or more and 100 mol %, and even more preferably 80 mol % or more and 100 mol % or less.

[0058] The other liquid crystal polymer compounds include polymer compounds having liquid crystal groups.For example, the polymer compounds that become the backbone include polyolefins such as polyethylene and polypropylene; cyclic olefin resins such as norbornene polymers; polyalkylene ethers, polyvinyl alcohols; polymethacrylic acid esters; polyacrylic acid esters; and the like, and these polymer compounds have liquid crystal groups.Among them, polymethacrylic acid esters and polyacrylic acid esters having liquid crystal groups are preferred.

[0059] The other liquid crystal polymer compound may contain two or more kinds of liquid crystal groups. The liquid crystal group may be contained in the main chain of the polymer compound which is the mother skeleton, may be contained in the side chain of the polymer compound which is the mother skeleton, or may be contained in both the main chain and the side chain of the polymer compound which is the mother skeleton. The liquid crystal group may be a group formed by removing one hydrogen atom from a compound having at least two 6-membered hydrocarbon ring structures, or a group formed by removing two hydrogen atoms from the compound.

[0060] The content of the liquid crystalline group in the other liquid crystalline polymer compound is usually 1 mol % or more and 100 mol % or less, based on the total amount of the structural units constituting the polymer compound that is the parent skeleton of the other liquid crystalline polymer compound. From the viewpoint of increasing the orientation of the other liquid crystalline polymer compound, the content is preferably 30 mol % or more and 100 mol % or less, more preferably 50 mol % or more and 100 mol % or less, and even more preferably 80 mol % or more and 100 mol % or less.

[0061] In the case where two or more kinds of polymerizable liquid crystal compounds are combined in the composition, it is preferable that at least one of them is a polymerizable liquid crystal compound (A), and more preferable that two or more of them are polymerizable liquid crystal compounds (A). By combining two or more kinds of polymerizable liquid crystal compounds, the liquid crystal phase may be temporarily maintained even at a temperature below the liquid crystal-crystal phase transition temperature. The content of the polymerizable liquid crystal compound (A) contained in the composition is preferably 40 mass% or more, more preferably 60 mass% or more, in total, based on the total mass of all polymerizable liquid crystal compounds in the composition, and all of the polymerizable liquid crystal compounds may be polymerizable liquid crystal compounds (A). When the content of the polymerizable liquid crystal compound (A) is within the above range, the polymerizable liquid crystal compounds are easily aligned with a high degree of orientation order, and the azo compound represented by formula (1) is aligned along the alignment, thereby making it possible to obtain a polarizing film with excellent polarization performance.

[0062] From the viewpoint of increasing the orientation of the polymerizable liquid crystal compound and the liquid crystalline polymer compound, the total content ratio of the polymerizable liquid crystal compound and the liquid crystalline polymer compound in the composition is, 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, relative to 100 parts by mass of the solid content of the composition.

[0063] 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, relative to 100 parts by mass of the total amount of the polymerizable liquid crystal compound and the liquid crystal polymer compound. When the content of the azo compound represented by formula (1) relative to the total amount of the polymerizable liquid crystal compound and the liquid crystal polymer compound is 50 parts by mass or less, the orientation disorder of the polymerizable liquid crystal compound, the liquid crystal polymer compound, and the azo compound represented by formula (1) is small, and a polarizing film having a high degree of orientation order tends to be obtained.

[0064] The composition may further contain a polymer compound in addition to the azo compound represented by formula (1), the polymerizable liquid crystal compound, and the liquid crystal polymer compound. When the composition contains a polymer compound, the azo compound represented by formula (1) may be easily dispersed in the composition. The polymer compound that the composition may contain is not particularly limited as long as it can disperse the azo compound represented by formula (1). In terms of easiness in uniformly dispersing the azo compound represented by formula (1), an acrylic polymer such as polymethyl methacrylate (PMMA) is preferred. The polymer compound may also be a polymer compound obtained by polymerizing the above-mentioned polymerizable liquid crystal compound. The weight average molecular weight of the polymer compound in terms of polystyrene is, for example, 10,000 to 200,000, preferably 20,000 to 150,000.

[0065] When the composition contains a polymer compound, the content thereof can be appropriately selected depending on the purpose, etc. 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, relative to 100 parts by mass of the solid content of the composition.

[0066] The composition preferably further contains a liquid medium such as a solvent and a polymerization initiator, and may further contain a photosensitizer, a polymerization inhibitor, a leveling agent, etc., as necessary.

[0067] The solvent is preferably a solvent capable of completely dissolving the azo compound represented by formula (1), the polymerizable liquid crystal compound, the liquid crystalline polymer compound, and the polymer compound, and is preferably a solvent inactive to the polymerization reaction of the polymerizable liquid crystal compound.

[0068] Examples of the solvent include alcohol solvents, ester solvents, ketone solvents, aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, nitrile solvents, ether solvents, chlorine-containing solvents, etc. These solvents may be used alone or in combination of two or more.

[0069] When the composition contains a solvent, the content of the solvent is preferably 50% by mass or more and 98% by mass or less with respect to the total amount of the composition. In other words, the content of 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 is low, and the thickness of the film obtained from the composition, for example, the film, tends to be approximately uniform, and the film tends to be less likely to have unevenness. The content of the solid content can be determined in consideration of the thickness of the film to be produced.

[0070] The polymerization initiator is a compound capable of initiating the polymerization reaction of the polymerizable liquid crystal compound. The polymerization initiator is preferably a photopolymerization initiator, since it can initiate the polymerization reaction under lower temperature conditions. Specifically, a photopolymerization initiator capable of generating active radicals or acids by the action of light is exemplified, and among them, a photopolymerization initiator capable of generating radicals by the action of light is preferred.

[0071] Examples of the polymerization initiator 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 according to the purpose. The polymerization initiator can be used alone or in combination of two or more.

[0072] When the composition contains a polymerization initiator, the content of the polymerization initiator may be appropriately determined according to the type and amount of the 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, and is, for example, 30% by mass or less, 10% by mass or less, or 8% by mass or less, relative to 100 parts by mass of the polymerizable liquid crystal compound. The content of the polymerization initiator is preferably 0.001 parts by mass or more and 30 parts by mass or less, 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, relative to 100 parts by mass of the polymerizable liquid crystal compound. When the content of the polymerization initiator is within the above range, the polymerizable liquid crystal compound can be polymerized without disturbing the orientation.

[0073] When the composition contains a photopolymerization initiator, the composition may preferably contain at least one type of photosensitizer. The composition contains a photopolymerization initiator and a photosensitizer, which tends to promote the polymerization reaction of the polymerizable liquid crystal compound. Examples of the photosensitizer include xanthone compounds such as xanthone and thioxanthone; anthracene compounds such as anthracene and alkoxy-substituted anthracene; phenothiazine and rubrene; and the like. The photosensitizer can be used alone or in combination of two or more types.

[0074] When the composition contains a photosensitizer, the content of the photosensitizer in the composition may be appropriately determined according to the type and amount of the photopolymerization initiator and the polymerizable liquid crystal compound. The content of the 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, relative to 100 parts by mass of the polymerizable liquid crystal compound.

[0075] The composition may contain at least one type of polymerization inhibitor. Examples of the polymerization inhibitor include radical scavengers such as hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (e.g., butylcatechol), pyrogallol, and 2,2,6,6-tetramethyl-1-piperidinyloxy radical; thiophenols; β-naphthylamines and β-naphthols; and the like. The composition contains a polymerization inhibitor, so that the degree of progress of the polymerization reaction of the polymerizable liquid crystal compound can be controlled.

[0076] When the composition contains a polymerization inhibitor, the content of the 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, relative to 100 parts by mass of the polymerizable liquid crystal compound.

[0077] 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 includes a surfactant. As the leveling agent, at least one selected from the group consisting of leveling agents mainly composed of a polyacrylate compound and leveling agents mainly composed of a fluorine atom-containing compound is preferable. The leveling agent may be used alone or in combination of two or more kinds.

[0078] 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, more preferably 0.05 parts by mass or more and 3 parts by mass or less, relative to 100 parts by mass of the total amount of the polymerizable liquid crystal compound and the liquid crystal polymer compound. When the content of the leveling agent is within the above range, the polymerizable liquid crystal compound and the liquid crystal polymer compound are easily horizontally aligned, and unevenness is unlikely to occur, and a smoother film, such as a polarizing film, tends to be obtained.

[0079] When the content of the leveling agent is within the above range, the polymerizable liquid crystal compound and the liquid crystalline polymer compound are easily horizontally aligned, and the obtained film tends to be smoother. When the content of the leveling agent relative to the polymerizable liquid crystal compound and the liquid crystalline polymer compound exceeds the above range, the obtained film tends to be easily uneven.

[0080] 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 against photodegradation of the azo compound (1), the antioxidant is preferably a so-called primary antioxidant that has an action of preventing autoxidation by capturing radicals. Therefore, it is more preferable that the antioxidant contained in the composition is 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 kinds.

[0081] The content of the antioxidant in the composition is preferably 0.1 parts by mass or more and 15 parts by mass or less, more preferably 0.3 parts by mass or more, even more preferably 0.5 parts by mass or more, more preferably 12 parts by mass or less, and even more preferably 10 parts by mass or less, based on 100 parts by mass of the composition. When the content of the antioxidant is equal to or more than the lower limit, the photodegradation of the azo compound (1) can be more effectively suppressed. When the content of the antioxidant is equal to or less than the upper limit, the alignment of the polymerizable liquid crystal compound is less likely to be disturbed, and a higher effect of suppressing the photodegradation of the azo compound (1) can be expected.

[0082] The composition may contain additives other than those described above. Examples of the additives include a release agent, a stabilizer, a colorant such as a bluing agent, a flame retardant, and a lubricant. When the composition contains other additives, the content of the other additives is preferably more than 0% and not more than 20% by mass, more preferably more than 0% and not more than 10% by mass, based on the solid content of the composition.

[0083] The composition can be produced by a conventionally known method for preparing a composition, for example, by mixing and stirring the azo compound represented by formula (1), a liquid crystal compound, and, if necessary, additives such as an antioxidant and a leveling agent.

[0084] film The film according to the present embodiment may be a film containing an azo compound represented by formula (1) as a forming material, or may be a film obtained by using a composition containing an azo compound represented by formula (1) and a liquid crystal 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. In addition, when 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, and then polymerizing and curing the polymerizable liquid crystal compound.

[0085] The composition can form a film having a high degree of orientation order and suppressing the occurrence of unevenness caused by an in-plane absorbance difference, such as a polarizing film. Therefore, the film according to the present embodiment includes a polarizing film formed from a composition containing an azo compound represented by formula (1) and a liquid crystal compound, which has a high degree of orientation order and suppresses the occurrence of unevenness caused by an in-plane absorbance difference.

[0086] Here, in a polarizing film with a high degree of orientational order, a Bragg peak derived from a higher-order structure such as a hexatic phase or a crystalline phase is obtained in an X-ray diffraction measurement. Therefore, in a polarizing film formed from a composition, it is preferable that the polymerizable liquid crystal compound or the liquid crystal polymer compound is oriented so as to show a Bragg peak in an X-ray diffraction measurement, and it is more preferable that the polymerizable liquid crystal compound or the liquid crystal polymer compound is oriented in a "horizontal orientation" in which the molecules of the polymerizable liquid crystal compound or the liquid crystal polymer compound are oriented in the direction in which light is absorbed. A high degree of orientational order that shows a Bragg peak can be achieved by controlling the type of the polymerizable liquid crystal compound or the liquid crystal polymer compound used, the amount of the azo compound represented by formula (1), etc.

[0087] The azo compound represented by formula (1) and the liquid crystal compound constituting the composition used to form the film are as described above.

[0088] The membrane can be produced, for example, by a method comprising the following steps. The first step is to form a coating film of a composition containing an azo compound represented by formula (1), a liquid crystal compound, and a solvent; A second step: removing at least a portion of the solvent from the coating; A third step: heating the liquid crystal compound to a temperature at which the liquid crystal compound undergoes a phase transition to a liquid phase or higher, and then lowering the temperature to cause the liquid crystal compound to undergo a phase transition to a smectic phase (smectic liquid crystal state); and A fourth step: if necessary, polymerizing the polymerizable liquid crystal compound while maintaining the smectic phase (smectic liquid crystal state).

[0089] The coating film of the composition can be formed, for example, by applying the composition onto a substrate, an alignment film described later, etc. Alternatively, the composition may be directly applied onto a retardation film or other layer constituting a polarizing plate.

[0090] The substrate is usually a transparent substrate. When the substrate is not placed on the display surface of a display element, for example, when a laminate obtained by removing the substrate from the film is placed on the display surface of a display element, the substrate does not have to be transparent. The transparent substrate means a substrate having transparency capable of transmitting light, particularly visible light, and the transparency means a property in which the transmittance of light in the wavelength range of 380 nm to 780 nm is 80% or more. A specific example of a transparent substrate is a translucent resin substrate.

[0091] Examples of resins constituting the light-transmitting resin substrate include polyolefins, cyclic olefin resins, polyvinyl alcohol, polyethylene terephthalate, polymethacrylic acid esters, polyacrylic acid esters, cellulose esters, polyethylene naphthalate, polycarbonates, polysulfones, polyethersulfones, polyether ketones, polyphenylene sulfide, and polyphenylene oxide. From the viewpoints of availability and transparency, polyethylene terephthalate, polymethacrylic acid esters, cellulose esters, cyclic olefin resins, and polycarbonates are preferred.

[0092] The properties required for the substrate vary depending on the film configuration, but generally, a substrate with as small a retardation as possible is preferred. Examples of substrates with as small a retardation as possible include cellulose ester films with no retardation, such as Zerotack (Konica Minolta Opto, Inc.) and Z-tack (FUJIFILM Corporation). Unstretched cyclic olefin resin substrates are also preferred. The surface of the substrate on which the film is not laminated may be subjected to hard coat treatment, antireflection treatment, antistatic treatment, etc.

[0093] The thickness of the substrate is usually 5 μm or more and 300 μm or less, preferably 20 μm or more and 200 μm or less, and more preferably 20 μm or more and 100 μm or less. If the thickness is equal to or more than the lower limit, the decrease in strength is suppressed and the processability tends to be good.

[0094] Examples of a method for applying the composition to a substrate or the like include known methods such as coating methods such as spin coating, extrusion, gravure coating, die coating, bar coating, and applicator methods, and printing methods such as flexography.

[0095] Next, at least a part of the solvent contained in the coating film obtained from the composition is removed by drying or the like to form a dry coating film. When the coating film contains a polymerizable liquid crystal compound, the coating film is dried under conditions in which the polymerizable liquid crystal compound does not polymerize to form a dry coating film. Examples of the drying method for the coating film include natural drying, ventilation drying, heat drying, and reduced pressure drying.

[0096] Furthermore, in order to cause the liquid crystal compound to undergo a phase transition to a liquid phase, the temperature is raised to a temperature at which the liquid crystal compound undergoes a phase transition to a liquid phase or higher, and then the temperature is lowered to cause the liquid crystal compound to undergo a phase transition to a smectic phase (smectic liquid crystal state). Such a phase transition may be performed after the solvent in the coating film is removed, or may be performed simultaneously with the removal of the solvent.

[0097] When the composition contains a polymerizable liquid crystal compound, the polymerizable liquid crystal compound is polymerized while maintaining the smectic liquid crystal state of the polymerizable liquid crystal compound, thereby forming a film containing a cured product of the polymerizable liquid crystal compound. The polymerization method is preferably a photopolymerization method. In photopolymerization, the light to be irradiated to the dried coating film is appropriately selected according to the type of photopolymerization initiator contained in the dried coating film, the type of polymerizable liquid crystal compound (particularly, the type of polymerizable group possessed by the polymerizable liquid crystal compound) and the amount thereof. Specific examples thereof include one or more types of light selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays and γ-rays, active electron beams, etc. Among them, ultraviolet light is preferred in that the progress of the polymerization reaction is easily controlled and that photopolymerization devices 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 by ultraviolet light. In addition, the polymerization temperature can also be controlled by irradiating light while cooling the dried coating film with an appropriate cooling means during polymerization. By adopting such a cooling means, the polymerization of the polymerizable liquid crystal compound can be performed at a lower temperature, and even if a substrate having a relatively low heat resistance is used, a film can be appropriately formed. During photopolymerization, a patterned film can be obtained by performing masking and development.

[0098] Examples of the light source of the active energy rays include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a halogen lamp, a carbon arc lamp, a tungsten lamp, a gallium lamp, an excimer laser, an LED light source emitting light in the wavelength range of 380 nm or more and 440 nm or less, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, and a metal halide lamp.

[0099] The UV irradiation intensity is usually 10mW / cm 2 More than 3,000mW / cm 2The ultraviolet irradiation intensity is preferably an intensity in a wavelength region effective for activating a photopolymerization initiator. The time for irradiating light may be usually 0.1 seconds or more and 10 minutes or less, preferably 0.1 seconds or more and 5 minutes or less, more preferably 0.1 seconds or more and 3 minutes or less, and further preferably 0.1 seconds or more and 1 minute or less. When irradiating once or multiple times with such ultraviolet irradiation intensity, the integrated light amount is 10 mJ / cm 2 More than 3,000mJ / cm 2 It is preferable that:

[0100] By carrying out photopolymerization, the polymerizable liquid crystal compound is polymerized while maintaining the liquid crystal state of the smectic phase, preferably the high-order smectic phase, to form 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 having higher polarization performance due to the action of the dichroic dye, compared to conventional host-guest type polarizing films, that is, films made of a liquid crystal state of a nematic phase. Furthermore, it has the advantage of being superior in strength compared to films coated with only a dichroic dye or a lyotropic liquid crystal.

[0101] The thickness of the film can be appropriately selected depending on the display device to which it is applied, and is preferably 0.5 μm or more and 10 μm or less, more preferably 1 μm or more and 5 μm or less, and further preferably 1 μm or more and 3 μm or less.

[0102] When the film is used as a polarizing film, it is preferable that the film is formed on an alignment film. The alignment film has an alignment regulating force that aligns the polymerizable liquid crystal compound and the liquid crystal polymer compound in a desired direction. The alignment film is preferably one that has solvent resistance that does not dissolve when a composition containing a liquid crystal compound including at least one of a polymerizable liquid crystal compound and a liquid crystal polymer compound is applied, and also has heat resistance in a heat treatment for removing the solvent or orienting the polymerizable liquid crystal compound. Examples of such alignment films include alignment films containing an alignment polymer, photo-alignment films, and groove alignment films having a concave-convex pattern or a plurality of grooves on the surface, and photo-alignment films are preferable from the viewpoint of the accuracy and quality of the alignment angle.

[0103] Laminate The laminate according to the present embodiment may comprise a film containing an azo compound represented by formula (1) as a forming material, or may comprise a film made of a composition containing an azo compound represented by formula (1) and a liquid crystal compound. The laminate may comprise a substrate and a film containing an azo compound represented by formula (1) as a forming material arranged on the substrate, or may comprise a substrate, an alignment film arranged on the substrate, and a film made of an azo compound represented by formula (1) as a forming material arranged 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 be a retardation film. The laminate may constitute, for example, a polarizing plate. The laminate may be manufactured, for example, by forming a film on the substrate in accordance with the above-mentioned method for manufacturing the film.

[0104] From the viewpoint of flexibility and visibility of the display device, the thickness of the laminate is preferably from 10 μm to 300 μm, more preferably from 20 μm to 200 μm, and further preferably from 25 μm to 100 μm.

[0105] When the laminate includes a retardation film as the substrate, the thickness of the retardation film can be appropriately selected depending on the display device to which it is applied.

[0106] display device The display device of the present embodiment includes the laminate, and the laminate 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 a pressure-sensitive adhesive layer. The display device is a device having a display element, and is a device including a light-emitting element or a light-emitting device as a light-emitting source. Examples of the display device include a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, an electron emission display device (e.g., a field emission display device (FED), a surface field emission display device (SED)), electronic paper (a display device using electronic ink, an electrophoretic element, etc.), a plasma display device, a projection display device (e.g., a display device having a grating light valve (GLV) display device, a digital micromirror device (DMD)), and a piezoelectric ceramic display. The liquid crystal display device includes any of a transmissive liquid crystal display device, a semi-transmissive liquid crystal display device, a reflective liquid crystal display device, a direct-view liquid crystal display device, and a projection liquid crystal display device. These display devices may be a display device that displays a two-dimensional image, or a stereoscopic display device that displays a three-dimensional image. In particular, as the display device, an organic EL display device and a touch panel display device are preferable, and an organic EL display device is particularly preferable. EXAMPLES

[0107] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0108] First, compound (1-1-a) was synthesized by a known diazo coupling method.

[0109] Synthesis Example 1: Synthesis of 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. A saturated aqueous solution of sodium bicarbonate was added to the reaction vessel, and the precipitated solid was filtered and washed with methanol. The obtained solid was purified by silica gel column chromatography using chloroform as a developing solvent to obtain compound (1-1) (0.171 g, yield 43%).

[0110] [ka]

[0111] 1 H-NMR (400MHz, CDCl3): δ(ppm)=7.93(d, 2H), 7.90(s, 1H), 7.81(d, 2H), 7.34(d, 2H), 6.74(d, 2H), 4.34(t, 2H), 3.50(q, 4H), 3.01(t,2H), 2.28(quin, 1H), 1.60(m, 2H), 1.39(m, 2H), 1.38-1.10(m, 26H), 0.84(t, 6H)

[0112] Synthesis Example 2: Synthesis of Compound (1-2) 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 isostearic acid (0.270 g, 0.949 mmol) were mixed, dissolved in 5 mL of THF, and stirred at room temperature for 26 hours. A saturated aqueous solution of sodium bicarbonate was added to the reaction vessel, and the precipitated solid was filtered and washed with methanol. The obtained solid was purified by silica gel column chromatography using chloroform as a developing solvent to obtain compound (1-2) (0.256 g, yield 61%).

[0113] [ka]

[0114] 1 H-NMR (400MHz, CDCl3): δ(ppm)=7.93(d, 2H), 7.90(s, 1H), 7.81(d, 2H), 7.35(d, 2H), 6.73(d, 2H), 4.32(m, 2H), 3.50(q, 4H) ), 3.01(t,2H), 2.28(quin, 1H), 1.76(m, 1H), 1.68(m, 1H) 1.39(m, 2H), 1.27(t, 6H), 1.15(m, 2H), 0.98(m, 4H), 0.85(m, 24H)

[0115] Comparative Synthesis Example 1: Synthesis of Compound (2-1) 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. A saturated aqueous solution of sodium bicarbonate was added to the reaction vessel, and the precipitated solid was filtered and washed with methanol. The obtained solid was purified by silica gel column chromatography using chloroform as a developing solvent to obtain compound (2-1) (0.049 g, 21% yield).

[0116] [ka]

[0117] 1 H-NMR (400MHz, CDCl3): δ(ppm)=7.95(d, 2H), 7.92(s, 1H), 7.82(d, 2H), 7.36(d, 2H), 6.75(d, 2H), 4.36(t, 2H), 3.5 2(q, 4H), 3.03(t, 2H), 2.19(quin, 1H), 1.60(m, 2H) 1.56(m, 2H), 1.54(m, 2H) 1.50(m, 2H), 1.28(t, 6H), 0.84(t, 6H)

[0118] Example 1: Preparation of composition E1 containing compound (1-1) The following components were mixed and stirred at 90° C. for 1 hour to obtain composition E1. ·Compound (1-1) 4.0 parts 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 weight 2-Dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369; BASF Japan) Leveling agent 1.2 parts by weight Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie) Solvent: toluene 250 parts by weight

[0119] The structures of the polymerizable liquid crystal compounds are as follows: The polymerizable liquid crystal compounds (A-6) and (A-8) were synthesized by the method described in Lub et al. Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996).

[0120] [ka]

[0121] A polarizing film was formed as follows using the composition E1 obtained above to obtain a laminate.

[0122] Formation of polarizing film The composition for forming a photo-alignment film was applied onto a glass substrate and dried at 120°C to obtain a dried coating film. The dried coating film was irradiated with polarized UV light to form a photo-alignment film, and glass with a photo-alignment film was obtained. The polarized UV light was irradiated using a UV irradiation device (SPOT CURE SP-7; Ushio Inc.) under the condition of an intensity of 100 mJ measured at a wavelength of 365 nm.

[0123] Composition E1 was applied onto glass with a photo-alignment film by spin coating, and then heated and dried on a hot plate at 120°C for 1 minute, and then quickly cooled to room temperature to form a dry coating film on the alignment film. Next, ultraviolet light was irradiated at an exposure dose of 2000 mJ / cm using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Inc.). 2 The polymerizable liquid crystal compound contained in the dried coating film was polymerized by irradiating the film with a wavelength of 313 nm (reference wavelength), and a polarizing film was formed from the dried coating film to obtain a laminate. The thickness of the polarizing film was measured with a laser microscope (OLS3000 manufactured by Olympus Corporation) and found to be 1.8 μm.

[0124] Example 2: Preparation of composition E2 containing compound (1-2) Except for using the compound (1-2) instead of the compound (1-1), the composition E2 was obtained in the same manner as in Example 1. The obtained composition E2 was used to form a polarizing film in the same manner as described above to obtain a laminate.

[0125] Comparative Example 1: Preparation of composition C1 containing compound (2-1) Except for using the compound (2-1) instead of the compound (1-1), the composition C1 was obtained in the same manner as in Example 1. The obtained composition C1 was used to form a polarizing film in the same manner as described above to obtain a laminate.

[0126] evaluation 1. Evaluation of unevenness The laminate obtained above was evaluated for unevenness of the polarizing film as follows. The absorbance (A1) in the absorption direction at the maximum absorption wavelength (λmax) of the polarizing film of the laminate was measured by the double beam method using a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation) with a folder containing the laminate set. Using the same measurement method as above, the position of the laminate was randomly changed and the absorbance (A1) in the absorption direction at the maximum absorption wavelength (λmax) was measured at a total of four points. The absorbance difference was determined by subtracting the minimum value from the maximum absorbance measured. The results are shown in Table 1. Note that an absorbance difference of 0.05 or less is considered to be a good polarizing plate with improved unevenness.

[0127] 2. Evaluation of dichroic ratio The dichroic ratio of the laminate obtained above was measured as follows. The absorbance (A1) in the transmission axis direction and the absorbance (A2) in the absorption axis direction at the maximum absorption wavelength (λmax) of the polarizing film of the laminate were measured by the double beam method using a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation) in which a folder with the laminate was set. A mesh that cuts the amount of light by 50% was placed on the reference side of the folder. The ratio (A2 / A1) of the absorbance (A2) in the absorption axis direction to the measured absorbance (A1) in the transmission axis direction was calculated and used as the dichroic ratio (DR). The results are shown in Table 1. In the table, - indicates that the value was not evaluated.

[0128] [Table 1]

[0129] From Table 1, it can be seen that the polarizing plate having a film made of a composition containing compound (1-1) or compound (1-2) had no in-plane absorbance difference and was able to form a high-quality film with little unevenness. It can also be seen that compound (1-1), which has a shorter branched chain length, has better characteristics when used as a polarizing plate.

Claims

1. An azo compound represented by the following formula (1): 【Chemistry 1】 In formula (1), Ar １ , Ar ２ and Ar ３ each independently represents a 1,4-phenylene group, a 1,4-naphthylene group or a divalent heterocyclic group, each of which may have a substituent; Ar １ , Ar ２ and Ar ３ At least one of these represents a divalent heterocyclic group formed by condensing two sulfur-containing aromatic rings and which may have a substituent. R ２ and R ３ R each independently represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms which may have a substituent. ２ and R ３ may be linked together to form an aliphatic ring, R ２ Or R ３ A part of the methylene groups constituting the aliphatic hydrocarbon group represented by the following formula may be substituted with an oxygen atom or a carbonyl group. R Ｓ R represents an aliphatic hydrocarbon group having 4 to 12 carbon atoms which may have a substituent. Ｌ may have a substituent, the number of carbon atoms is R Ｓ represents an aliphatic hydrocarbon group having more carbon atoms than R ２ , R ３ , R Ｓ and R Ｌ At least one selected from the group consisting of 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 a straight-chain or branched-chain alkylene group having 1 to 4 carbon atoms. k represents 1 or 2, and when k is 2, two Ar ２ may be the same or different.

2. The compound according to claim 1 , wherein in the formula (1), L is represented by the following formula (1a): 【Chemistry 2】 In formula (1a), R ４ each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. P and Q each independently represent a single bond, --O--, --OC(.dbd.O)--, --C(.dbd.O)O--, or --S--. x and y each independently represent a number from 0 to 4. * represents a bonding position.

3. In the formula (1), Ar １ and Ar ３ The compound according to claim 1, wherein represents an optionally substituted 1,4-phenylene group.

4. In the formula (1), Ar ２ represents an optionally substituted thieno[3,2-d]thiazolediyl group or thieno[3,2-d]thiophenediyl group, and k is 1.

5. A composition comprising the azo compound according to claim 1 and a liquid crystal compound comprising at least one of a polymerizable liquid crystal compound and a liquid crystal polymer compound.

6. The composition according to claim 5, wherein the liquid crystal compound is a smectic liquid crystal compound.

7. A film formed from the composition according to claim 5 or 6.

8. A laminate comprising the film according to claim 7.

9. A display device comprising the film according to claim 7 or the laminate according to claim 8.

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