Azo compound, composition, film, laminate, and display device

Abstract

The invention relates to an azo compound, a composition, a film, a laminate, and a display device. The present invention addresses the problem of providing an azo compound capable of suppressing the occurrence of unevenness due to a difference in in-plane absorbance of a formed polarizing film. [Solution] An azo compound represented by formula (1). Ar1, Ar2, and Ar3 each independently represent a 1, 4-phenylene group, a 1, 4-naphthylene group, or a divalent heterocyclic group which may have a substituent. R2 and R3 each independently represent a C1-10 aliphatic hydrocarbon group which may have a substituent, and may be linked to each other to form an aliphatic ring, and a portion of the methylene group may be substituted by an oxygen atom or a carbonyl group. And RS represents an aliphatic hydrocarbon group having 4 to 12 carbon atoms. RL represents an aliphatic hydrocarbon group having more carbon atoms than RS. L represents a linking group comprising at least one selected from the group consisting of-O-,-S-,-C (= O)-and a C1-4 linear or branched alkylene group. And k represents 1 or 2. # imgabs0 #

Description

Technical Field

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

[0002] As a polarizing film (optical film) used in a liquid crystal display device, etc., a polarizing film formed of a composition containing a dichroic dye is known. 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] [Chemical formula 1]

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2022-88325 Summary of the invention

[0007] Problems to be solved by the invention

[0008] For polarizing films made using the dichroic dye represented by the above formula, when the sample after film formation is checked, unevenness due to the difference in absorbance within the surface is sometimes observed. The object of the present invention is to provide an azo compound capable of suppressing the generation of unevenness after film formation, a composition containing the azo compound, a film formed from the composition, a laminate having the film, and a display device having the laminate.

[0009] Means for solving problems

[0010] The present invention provides the following [1] to

[10] .

[0011] [1] A compound represented by the following formula (1).

[0012] [Chemical formula 2]

[0013]

[0014]

[0015] 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 which may have a substituent, Ar 1 ,Ar 2 and Ar 3 At least one of them represents a divalent heterocyclic group which is formed by condensing two sulfur-containing aromatic rings and which may have a substituent.

[0016] R 2 and R3 Each independently represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms which may have a substituent. 2 With R 3 They can also be connected to form an aliphatic ring, forming R 2 or R 3 A part of the methylene groups of the aliphatic hydrocarbon groups represented by may be replaced by oxygen atoms or carbonyl groups.

[0017] R S represents an aliphatic hydrocarbon group having 4 to 12 carbon atoms which may have a substituent. L represents a carbon atom number ratio R S An aliphatic hydrocarbon group having a large number of carbon atoms.

[0018] Choose from R 2 , R 3 , R S and R L At least one of the constituent groups may have a polymerizable group.

[0019] L represents a linking group consisting 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.

[0020] k represents 1 or 2. When k is 2, two Ar 2 Each may be the same or different.

[0021] [2] The compound according to [1], wherein in the above formula (1), L is represented by the following formula (1a).

[0022] [Chemical formula 3]

[0023]

[0024] In formula (1a), R 4 Each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0025] P and Q each independently represent a single bond, -O-, -OC(=O)-, -C(=O)O- or -S-.

[0026] x and y each independently represent a number from 0 to 4. * represents a bonding position.

[0027] [3] The compound according to [1] or [2], wherein in the above formula (1), Ar 1 and Ar 3 It represents a 1,4-phenylene group which may have a substituent.

[0028] [4] The compound according to any one of [1] to [3], wherein in the formula (1), Ar 2 represents a thieno[3,2-d]thiazoldiyl group or a thieno[3,2-d]thiophenediyl group which may have a substituent, and k is 1.

[0029] [5] A composition comprising the azo compound according to any one of [1] to [4], and a liquid crystal compound, wherein the liquid crystal compound comprises at least one of a polymerizable liquid crystal compound and a liquid crystal polymer compound.

[0030] [6] The composition according to [5], wherein the liquid crystal compound is a smectic liquid crystal compound.

[0031] [7] A film formed from the composition described in [5] or [6] as a material.

[0032] [8] A laminate comprising the film according to [7].

[0033] [9] A display device comprising the film described in [7] or the laminate described in [8].

[0034] Effects of the Invention

[0035] According to the present invention, it is possible to provide an azo compound capable of suppressing generation 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. DETAILED DESCRIPTION

[0036] 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 the desired purpose of the process can be achieved. In addition, for the content of each component in the composition, when there are multiple substances belonging to each component in the composition, unless otherwise specified, it refers to the total amount of the multiple substances present in the composition. In addition, for the upper and lower limits of the numerical ranges recorded in this specification, the numerical values ​​​​exemplified as numerical ranges can be arbitrarily selected and combined. Below, the embodiments of the present invention are described in detail. It should be noted that the scope of the present invention is not limited to the embodiments described herein, and various changes can be made within the scope of not damaging the main purpose of the present invention.

[0037] Azo compounds

[0038] The azo compound involved in one embodiment of the present invention is represented by the following formula (1). The azo compound can be, for example, a dichroic pigment compound, and can be used as a material for forming a polarizing film. With respect to the azo compound represented by formula (1), it is believed that, for example, since the aliphatic hydrocarbon group connected to L has a long chain structure, the interaction with the side chain of the liquid crystal molecule constituting the polarizing film becomes stronger. In addition, it is believed that, since it has an asymmetric branched structure, the liquid crystal state during the cooling process of the coating film can be maintained in a good state. It is further believed that, for example, since R constituting the branched chain L With R S Since the aliphatic hydrocarbon chains have different lengths, the liquid crystal state of the coating film can be kept in a good state during the cooling process. It is considered that these effects can suppress the occurrence of unevenness after the polarizing film is formed.

[0039] [Chemical formula 4]

[0040]

[0041] In formula (1), Ar 1 ,Ar 2 and Ar 3 Each 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. 1 ,Ar 2 and Ar 3 At least one of them represents a divalent heterocyclic group which is 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 heterocyclic compounds include 5-membered aromatic heterocyclic compounds such as thiophene, thiazole, and furan, and aromatic condensed heterocyclic compounds formed by condensing the aromatic heterocyclic compounds with other aromatic heterocyclic compounds or aromatic hydrocarbon compounds. Specifically, examples of heterocyclic compounds include thiophene, thiazole, furan, thienothiophene, dithienothiophene, thienothiazole, thiazolothiazole, furothiazole, and benzothiazole. 1 ,Ar 2 or Ar 3The divalent heterocyclic group represented by , specifically, includes thiophenediyl, thiazoldiyl, dithieno[3,2-b;2',3'-d]thiophenediyl, thieno[3,2-d]thiazoldiyl, thieno[3,2-d]thiazoldiyl, thiazol[5,4-d]thiazoldiyl, furano[3,2-d]thiazoldiyl, benzothiazoldiyl, etc., and may contain at least one selected from the group consisting of these. The heterocyclic group may preferably contain at least one selected from the group consisting of thieno[3,2-d]thiazoldiyl and thieno[3,2-d]thiophenediyl.

[0042] Ar 1 Preferably, it may represent a 1,4-phenylene group which may have a substituent or a divalent heterocyclic group which may have a substituent, or it may represent a 1,4-phenylene group which may have a substituent. 3 Preferably, it can represent 1,4-phenylene which may have a substituent.

[0043] Ar 2 Ar may represent a divalent heterocyclic group which may have a substituent, or may represent a divalent heterocyclic group which may have a substituent and is formed by condensing two sulfur-containing aromatic rings. 2 The heterocyclic group represented by may be, for example, a group formed by removing two hydrogen atoms from an aromatic condensed heterocyclic compound formed by condensing two 5-membered sulfur-containing aromatic heterocyclic compounds. Examples of the 5-membered sulfur-containing aromatic heterocyclic compound include thiophene and thiazole. Specifically, examples of the heterocyclic group formed by condensing two sulfur-containing aromatic rings include thieno[3,2-d]thiazoldiyl, thieno[3,2-d]thienyl, thiazol[5,4-d]thiazoldiyl, and the like, and may include at least one selected from the group consisting of these. The heterocyclic group formed by condensing two sulfur-containing aromatic rings may preferably include at least one selected from the group consisting of thieno[3,2-d]thiazoldiyl and thieno[3,2-d]thienyl.

[0044] 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 hydroxyl 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 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 3 The number of substituents in each independently may be, for example, 0, 1 or 2, preferably 0 or 1.

[0045] k is 1 or 2, and may be preferably 1. In the case where k is 2, two Ar2 Each may be the same or different.

[0046] R 2 and R 3 Each independently represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms which may have a substituent. The carbon number 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 alkyl, alkenyl, and alkynyl groups, preferably alkyl. Specifically, examples of the alkyl group include methyl, ethyl, and propyl. R 2 With R 3 They can also be connected to form an aliphatic ring, forming R 2 or R 3 A portion of the methylene groups of the aliphatic hydrocarbon group represented by may be replaced by oxygen atoms or carbonyl groups. The ring formed may be a nitrogen-containing aliphatic ring, and the number of members thereof may be, for example, 5 or 6. 2 With R 3 Examples of the ring formed by bonding together include pyrrolidinyl, piperidinyl, oxazolidinyl, and morpholinyl.

[0047] R S represents an aliphatic hydrocarbon group having 4 to 12 carbon atoms which may have a substituent. S The carbon number of the aliphatic hydrocarbon group represented by may be preferably 4 or more and 8 or less, and more preferably 4 or more and 6 or less. L represents an aliphatic hydrocarbon group which may have a substituent, R L The carbon number of R S The number of carbon atoms is large. L The carbon number of the aliphatic hydrocarbon group represented by 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 may be, for example, 1 to 10, and preferably 2 to 6. L The number of carbon atoms and R S The sum of the number of carbon atoms of can be, for example, 10 to 26, preferably 10 to 14. L The number of carbon atoms and R S The difference in the number of carbon atoms is within the aforementioned range and R S When the number of carbon atoms is within the aforementioned range, the disorder of the orientation of the liquid crystal can be more effectively suppressed, thereby more effectively suppressing the generation of unevenness after film formation and achieving a better dichroic ratio.

[0048] R S or R LThe aliphatic hydrocarbon group represented by may be branched or linear, and preferably may be linear. Examples of the aliphatic hydrocarbon group include an alkyl group, an alkenyl group, and an alkynyl group, and preferably may be an alkyl group.

[0049] Choose from R 2 , R 3 , R S and R L At least one of the groups may have a polymerizable group as a substituent. Specifically, the polymerizable group includes 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 free radical polymerizable group, and preferably a (meth)acrylate group. 2 , R 3 , R S and R L The total number of the polymerizable groups may be, for example, 1 or 2, and preferably 1.

[0050] L represents a linking group formed by 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, the linking group represented by L is preferably selected in a manner that does not 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. As a divalent group represented by L, specifically, alkylene, alkyleneoxy, alkyleneoxycarbonyl, alkylenecarbonyloxy, alkylenecarbonyl, oxyalkylene, oxycarbonylalkylene, carbonyloxyalkylene, carbonylalkylene, carbonylalkyleneoxy, alkyleneoxyalkylene, carbonyloxyalkyleneoxy, carbonyloxyalkyleneoxyalkylene, carbonylalkyleneoxy, carbonylalkyleneoxy, alkylenesulfanyl (alkylene sulfanyl group), sulfanylalkylene, alkylenesulfanylalkylene, carbonyloxyalkylenesulfanylalkylene, etc. can be cited. The total number of carbon atoms excluding carbonyl carbon atoms in 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).

[0051] [Chemical formula 5]

[0052]

[0053] In formula (1a), R 4 Each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. 4 The number of carbon atoms of the alkyl group represented by may preferably be 1 to 2, or 1. The two R groups bonded to the same carbon atom 4In the formula (1a), at least one or both of them 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, preferably 1 to 6, 1 to 4, or 1 to 3. * represents a bonding position.

[0054] Specific examples of the azo compound represented by the formula (1) include azo compounds represented by the following formulae (1-1) to (1-32), but the present invention is not limited thereto.

[0055] [Chemical formula 6]

[0056]

[0057] From the viewpoint of suppressing unevenness in 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).

[0058] Method for producing azo compounds

[0059] The azo compound represented by formula (1) can be produced by appropriately applying a conventionally known synthesis method. Specifically, for example, reference can be made to the production method described in Japanese Unexamined Patent Publication No. 2022-088325.

[0060] Dichroic Pigments

[0061] The dichroic pigment comprises the azo compound represented by formula (1) as an effective ingredient. Because the dichroic pigment comprises the azo compound represented by formula (1), therefore, in the polarizing film formed, it is possible to suppress the uneven generation caused by the absorbance difference in the plane. The dichroic pigment can be combined to comprise two or more compounds with different structures in the azo compound represented by formula (1). In the case where the dichroic pigment comprises the azo compound represented by more than two formulas (1), they can have maximum absorption wavelengths different from each other. In addition, the dichroic pigment can also comprise other pigment compounds other than the azo compound represented by formula (1).

[0062] Composition

[0063] The composition of the present embodiment comprises at least one of the azo compounds represented by formula (1) and a liquid crystal compound, wherein the liquid crystal compound comprises at least one of a polymerizable liquid crystal compound and a liquid crystal polymer compound. The composition can be used as a forming material for a polarizing film, for example. That is, the composition can be a composition for forming a polarizing film. The polarizing film obtained by using the composition as a forming material is a high-quality polarizing film that suppresses the generation of unevenness caused by the difference in absorbance within the plane and shows a good dichroic ratio.

[0064] Relative to 100 parts by mass of the solid content of the composition, the content of the azo compound represented by formula (1) in the composition can 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. If it is within the above range, the dispersion of the azo compound represented by formula (1) can be fully achieved. It should be noted that, in this specification, the so-called solid content refers to the total amount of components after removing volatile components such as solvents from the composition. The composition may contain only one azo compound represented by formula (1), or a combination of two or more azo compounds represented by formula (1) having different structures. When the composition contains two or more azo compounds, they may have different maximum absorption wavelengths from each other.

[0065] The composition may further include other pigment compounds other than the azo compound represented by formula (1), such as at least one of the dichroic pigments. As other pigment compounds, for example, azo pigments such as monoazo pigments, disazo pigments, triazo pigments, tetrazo pigments, stilbene azo pigments can be cited, preferably at least one selected from the group consisting of them. The composition may contain one other pigment compound alone, or may contain two or more in combination. For example, when used as a coating type polarizing plate material, the other pigment compounds contained in the composition preferably have a maximum absorption wavelength in a wavelength range different from the compound represented by formula (1). For example, when used as a coating type polarizing plate material, the composition preferably includes a compound represented by formula (1) and a combination of more than three dichroic pigments, more preferably a combination of more than three azo pigments. By making the composition combination contain more than three pigment compounds with different maximum absorption wavelengths, for example, it is possible to obtain absorption in the entire visible light domain using a film formed by the composition.

[0066] When composition comprises other pigment compounds, its content can be, for example, below 50 mass parts relative to 100 mass parts of the solid component of composition, and can preferably be below 10 mass parts or above 5 mass parts of 0.1 mass parts. If within the above-mentioned scope, the dispersion of other pigment compounds can be fully carried out.

[0067] The composition includes a liquid crystal compound in addition to the azo compound represented by formula (1), and the liquid crystal compound includes at least one of a polymerizable liquid crystal compound and a liquid crystal polymer compound. The composition may also include both a polymerizable liquid crystal compound and a liquid crystal polymer compound, and the polymerizable liquid crystal compound and the liquid crystal polymer compound included in the composition may each be two or more. By making the composition include 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 a liquid crystal compound can be formed.

[0068] The liquid crystalline polymer compound may be a polymer compound constituting a thermotropic liquid crystalline polymer or a polymer compound constituting a lyotropic liquid crystalline polymer. From the viewpoint of enabling precise film thickness control, the liquid crystalline polymer compound is preferably a polymer compound constituting a thermotropic liquid crystalline polymer.

[0069] As a classification of liquid crystal, according to the structure of molecular arrangement in the liquid crystal state, it can be divided into smectic liquid crystal, nematic liquid crystal, and cholesteric liquid crystal. Among them, in the use of polarizing film, smectic liquid crystal is preferably used. Therefore, the polymerizable liquid crystal compound is preferably a polymerizable smectic liquid crystal compound, and the liquid crystal polymer compound is preferably a smectic liquid crystal polymer compound.

[0070] By using a polymerizable liquid crystal compound showing smectic liquid crystal properties and a polymer compound showing smectic liquid crystal properties, a polarizing film with a high degree of orientation order can be formed. The liquid crystal state displayed by the polymerizable liquid crystal compound and the liquid crystal polymer compound is preferably a smectic phase (smectic liquid crystal state), and from the viewpoint of being able to achieve a higher degree of orientation order, it is more preferably a high-order smectic phase (high-order smectic liquid crystal state). Here, the so-called high-order smectic phase refers to 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, among which smectic B phase, smectic F phase and smectic I phase are more preferably used. The polarizing film with a high degree of orientation order can obtain Bragg peaks derived from higher-order structures such as hexagonal phases and crystalline phases in X-ray diffraction measurements. The so-called Bragg peak refers to the peak of the planar periodic structure derived from molecular orientation. The period interval (ordered period) possessed by the polarizing film obtained by the composition is preferably 0.3nm or more and 0.6nm or less. The polymerizable liquid crystal compound or liquid crystalline high molecular compound may be a polymerizable smectic liquid crystal compound or a smectic liquid crystalline high molecular compound which shows a Bragg peak derived from a higher order structure in X-ray diffraction measurement.

[0071] The compound represented by formula (1) can show high dichroism even in a dense molecular chain dispersion state formed by at least one of a polymerizable liquid crystal compound of smectic liquid crystal and a polymer compound of smectic liquid crystal. Therefore, a composition containing at least one liquid crystal compound including a polymerizable liquid crystal compound and a liquid crystal polymer compound (especially a liquid crystal compound including a polymerizable liquid crystal compound of smectic liquid crystal and at least one liquid crystal compound of smectic liquid crystal polymer compound) and a compound represented by formula (1) can provide a polarizing film with a high dichroic ratio in which the unevenness caused by the absorbance difference within the plane is suppressed in the formed polarizing film.

[0072] The so-called polymerizable liquid crystal compound is a compound having at least one polymerizable group in the molecule and capable of presenting a liquid crystal phase by orientation. The polymerizable liquid crystal compound is preferably a compound capable of presenting a liquid crystal phase by orientation alone. The so-called polymerizable group refers to a functional group that can participate in a polymerization reaction, preferably a free radical polymerizable group.

[0073] Specifically, as the polymerizable liquid crystal compound, for example, preferably, there is mentioned a compound represented by the following formula (A) (hereinafter, also referred to as “polymerizable liquid crystal compound (A)”).

[0074] U 1 -V 1 -W 1 -(X 1 -Y 1 ) m -X 2 -Y 2 -X 3 -W 2 -V 2 -U 2 (A)

[0075] 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 They may be the same or different from each other. 1 , X 2 and X 3 At least three of 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 They may be the same or different from each other.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 the -CH2- groups constituting the alkanediyl group may be replaced by -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.

[0076] As X 1 , X 2 and X 3 Examples of the divalent aromatic group in X include 1,4-phenylene and 1,4-naphthylene. Examples of the divalent alicyclic hydrocarbon group include cyclohexane-1,4-diyl and the like. 1 , X 2 and X 3 At least one of the divalent aromatic group and the divalent alicyclic hydrocarbon group may have a substituent. As the substituent, alkyl groups having 1 to 4 carbon atoms such as methyl, ethyl, and n-butyl, cyano, and halogen atoms may be cited. At least one of -CH2- constituting the divalent alicyclic hydrocarbon group may be replaced by -O-, -S-, or -NR-. Here, R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group.

[0077] As X 1 , X 2 and X 3 Examples of the divalent 6-membered hydrocarbon ring group include 1,4-phenylene which may have a substituent, and cyclohexane-1,4-diyl which may have a substituent.

[0078] X 1 , X 2 and X 3 The divalent aromatic group in is preferably a 1,4-phenylene group which may have a substituent, and more preferably an unsubstituted 1,4-phenylene group. In addition, the divalent alicyclic hydrocarbon group is preferably a cyclohexane-1,4-diyl group which may have a substituent, and more preferably a trans-cyclohexane-1,4-diyl group which may have a substituent, and further preferably an unsubstituted trans-cyclohexane-1,4-diyl group.

[0079] Y 1 and Y 2 Each independently represents a single bond or a divalent linking group. For example, a divalent linking group is selected from -CH2CH2-, -CH2O-, -(C=O)O-, -O(C=O)O-, -N=N-, -CR a =CR b -, -C≡C- and -CR a = At least one of the group consisting of N-. Here, R a and R bEach independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. 1 Preferably, Y is -CH2CH2-, -(C=O)O- or a single bond. 2 Preferred is -CH2CH2- or -CH2O-.

[0080] W 1 and W 2 Each independently represents a single bond or a divalent linking group. For example, the divalent linking group is at least one selected from the group consisting of -O-, -S-, -(C=O)O-, and -O(C=O)O-. 1 and W 2 Each independently is preferably a single bond or -O-.

[0081] V 1 and V 2 Each independently represents an alkanediyl group having 1 to 20 carbon atoms and which may have a substituent. At least one of the -CH2- groups constituting the alkanediyl group may be replaced by -O-, -CO-, -S- or -NH-.

[0082] As V 1 and V 2 Examples of the alkane diyl represented by V 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 2 It is preferably an alkanediyl group having 2 to 12 carbon atoms, and more preferably an alkanediyl group having 6 to 12 carbon atoms.

[0083] 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.

[0084] 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 Preferably, it is a polymerizable group. Preferably, U 1 and U 2 All of them are polymerizable groups, preferably all of them are free radical polymerizable groups. 1 The polymerizable group represented by U 2 The polymerizable groups represented by may be different from each other, but are preferably groups of the same type. 1 and U2 The polymerizable groups in U can be the same as those exemplified above as the polymerizable groups possessed by the polymerizable liquid crystal compound. 1 and U 2 The polymerizable group represented by is preferably at least one selected from the group consisting of a vinyloxy group, an acryloyloxy group, a methacryloyloxy group, an oxirane group, and an oxetanyl group, and more preferably an acryloyloxy group.

[0085] 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.

[0086] [Chemical formula 7]

[0087]

[0088] [Chemical formula 8]

[0089]

[0090] [Chemical formula 9]

[0091]

[0092] Among them, the polymerizable liquid crystal compound (A) is preferably at least one selected from the group consisting of compounds represented by any one of formula (A-2), formula (A-3), formula (A-4), formula (A-5), formula (A-6), formula (A-7), formula (A-8), formula (A-13), formula (A-14), formula (A-15), formula (A-16) and formula (A-17). The polymerizable liquid crystal compound (A) can be used alone or in combination of two or more.

[0093] The polymerizable liquid crystal compound (A) can be produced by the method described in known documents such as Lub et al. Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996) and Japanese Patent No. 4719156.

[0094] The so-called liquid crystalline polymer compound may be a compound obtained by polymerizing the aforementioned polymerizable liquid crystal compound (hereinafter also referred to as a polymer of the polymerizable liquid crystal compound), or may be other liquid crystalline polymer compounds, and is preferably a polymer of the aforementioned polymerizable liquid crystal compound.

[0095] The polymer of the polymerizable liquid crystal compound may contain two or more of the polymerizable liquid crystal compounds as raw material monomers. In addition, the polymer of the polymerizable liquid crystal compound may contain other monomers other than the polymerizable liquid crystal compound as raw material monomers.

[0096] The content ratio of the aforementioned polymerizable liquid crystal compound in the polymer of the aforementioned polymerizable liquid crystal compound is generally from 1 mol % to 100 mol % relative to the total amount of structural units derived from the aforementioned polymerizable liquid crystal compound constituting the polymer of the aforementioned polymerizable liquid crystal compound. From the viewpoint of improving the orientation of the polymer of the aforementioned polymerizable liquid crystal compound, it is preferably from 30 mol % to 100 mol %, more preferably from 50 mol % to 100 mol %, and further preferably from 80 mol % to 100 mol %.

[0097] As the aforementioned other liquid crystal polymer compounds, polymer compounds having liquid crystal groups can be cited. For example, as polymer compounds forming the mother skeleton, polyolefins such as polyethylene and polypropylene; cyclic olefin resins such as norbornene polymers; polyalkylene ethers, polyvinyl alcohols; polymethacrylates; polyacrylates; etc., these polymer compounds have liquid crystal groups. Among them, polymethacrylates and polyacrylates having liquid crystal groups are preferred.

[0098] The aforementioned other liquid crystal polymer compounds may include more than two liquid crystal groups. The liquid crystal group may be included in the main chain of the polymer compound forming the mother skeleton, may be included in the side chain of the polymer compound forming the mother skeleton, or may be included in both the main chain and the side chain of the polymer compound forming the mother skeleton. As the liquid crystal group, a group formed by removing one hydrogen atom from a compound having at least two 6-membered cyclic hydrocarbon structures or a group formed by removing two hydrogen atoms from the compound may be cited.

[0099] The content ratio of the liquid crystal groups in the aforementioned other liquid crystal polymer compounds is generally from 1 mol % to 100 mol % relative to the total amount of the structural units of the polymer compounds constituting the mother skeleton of the aforementioned other liquid crystal polymer compounds. From the viewpoint of improving the orientation of the aforementioned other liquid crystal polymer compounds, it is preferably from 30 mol % to 100 mol %, more preferably from 50 mol % to 100 mol %, and further preferably from 80 mol % to 100 mol %.

[0100] In the case of combining more than two polymerizable liquid crystal compounds in the composition, it is preferred that at least one of them is a polymerizable liquid crystal compound (A), and more preferably more than two of them are polymerizable liquid crystal compounds (A). By combining more than two polymerizable liquid crystal compounds, the liquid crystal phase can sometimes be temporarily maintained even at a temperature below the liquid crystal-crystallization phase transition temperature. Relative to the total mass of all polymerizable liquid crystal compounds in the composition, the content of the polymerizable liquid crystal compound (A) contained in the composition is preferably more than 40% by mass, more preferably more than 60% by mass, and all polymerizable liquid crystal compounds can be polymerizable liquid crystal compounds (A). If the content of the polymerizable liquid crystal compound (A) is within the above range, the polymerizable liquid crystal compound is easily arranged with a high degree of orientation order, and the azo compound represented by formula (1) is oriented along it, thereby being able to obtain a polarizing film with excellent polarization performance.

[0101] From the viewpoint of improving the orientation of polymerizable liquid crystal compounds and liquid crystalline polymer compounds, the total content ratio of the polymerizable liquid crystal compounds and liquid crystalline polymer compounds in the composition relative to 100 parts by mass of the solid content of 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, further 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 further preferably 80 parts by mass or more and 90 parts by mass or less.

[0102] Relative to the total amount of 100 parts by mass of the polymerizable liquid crystal compound and the liquid crystalline polymer compound, 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 further preferably 0.1 parts by mass or more and 5 parts by mass or less. If the content of the azo compound represented by formula (1) relative to the total amount of the polymerizable liquid crystal compound and the liquid crystalline polymer compound is 50 parts by mass or less, the orientation disorder of the polymerizable liquid crystal compound, the liquid crystalline polymer compound and the azo compound represented by formula (1) is small, and there is a tendency to obtain a polarizing film with a high degree of orientation order.

[0103] The composition may include a polymer compound in addition to the azo compound represented by formula (1), a polymerizable liquid crystal compound and a liquid crystal polymer compound. By making the composition include a polymer compound, the azo compound represented by formula (1) is sometimes easily dispersed in the composition. There is no particular limitation on the polymer compound that can be included in the composition as long as the azo compound represented by formula (1) can be dispersed. From the perspective of making it easy to evenly disperse the azo compound represented by formula (1), acrylic polymers such as polymethyl methacrylate (PMMA) are preferred. In addition, 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 converted to polystyrene is, for example, more than 10,000 and less than 200,000, preferably more than 20,000 and less than 150,000.

[0104] When the composition contains a polymer compound, its content can be appropriately selected according to 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 further preferably 3.0 parts by mass or less relative to 100 parts by mass of the solid content of the composition.

[0105] 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, and the like as necessary.

[0106] The solvent is preferably a solvent that can completely dissolve the azo compound represented by formula (1), the polymerizable liquid crystal compound, the liquid crystal polymer compound, and the polymer compound. In addition, the solvent is preferably inactive to the polymerization reaction of the polymerizable liquid crystal compound.

[0107] 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.

[0108] When the composition includes a solvent, the content of the solvent is preferably 50% by mass or more and 98% by mass or less relative to the total amount of the composition. In other words, the content of the solid component in the composition is preferably 2% by mass or more and 50% by mass or less. If the solid component is 50% by mass or less, the viscosity of the composition decreases, and the film obtained by the composition, such as the thickness of the film, becomes roughly uniform, and there is a tendency that it is not easy to produce unevenness in the film. The content of the solid component can be determined by considering the thickness of the film to be manufactured.

[0109] The polymerization initiator is a compound that can initiate the polymerization reaction of the polymerizable liquid crystal compound. From the aspect of being able to initiate the polymerization reaction under lower temperature conditions, the polymerization initiator is preferably a photopolymerization initiator. Specifically, a photopolymerization initiator that can generate active free radicals or acids by the action of light can be cited, among which a photopolymerization initiator that generates free radicals by the action of light is preferred.

[0110] As the polymerization initiator, benzoin compounds, benzophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, triazine compounds, iodonium salts, and sulfonium salts can be mentioned. The polymerization initiator can be appropriately selected from known polymerization initiators according to the purpose, etc. In addition, the polymerization initiator can be used alone or in combination of two or more.

[0111] When the composition contains a polymerization initiator, its content can be appropriately determined according to the type and amount of the polymerizable liquid crystal compound contained in the composition. Relative to 100 parts by mass of the polymerizable liquid crystal compound, 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, for example, 30% by mass or less, 10% by mass or less, or 8% by mass or less. In addition, 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 less and 30 parts by mass or less, more preferably 0.01 parts by mass or less and 10 parts by mass or less, and further preferably 0.1 parts by mass or less and 8 parts by mass or less. If the content of the polymerization initiator is within the above range, polymerization can be performed without disturbing the orientation of the polymerizable liquid crystal compound.

[0112] When the composition contains a photopolymerization initiator, the composition may preferably contain at least one of the photosensitizers. By making the composition contain a photopolymerization initiator and a photosensitizer, there is a tendency that the polymerization reaction of the polymerizable liquid crystal compound is further promoted. 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 may be used alone or in combination of two or more.

[0113] When the composition includes a photosensitizer, the content of the photosensitizer in the composition can 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 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and further preferably 0.5 to 8 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound.

[0114] The composition may contain at least one of the polymerization inhibitors. As the polymerization inhibitor, for example, free radical scavengers such as hydroquinone, hydroquinone containing an alkoxy group, catechol containing an alkoxy group (such as butyl catechol), pyrogallol, and 2,2,6,6-tetramethylpiperidin-1-oxyl free radicals; thiophenols; β-naphthylamines and β-naphthols; and the like can be cited. By making the composition contain a polymerization inhibitor, the degree of the polymerization reaction of the polymerizable liquid crystal compound can be controlled.

[0115] When the composition contains a polymerization inhibitor, the content of the polymerization inhibitor in the composition is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 0.5 to 8 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound.

[0116] The composition may contain at least one of the leveling agents. The leveling agent has the function of adjusting the fluidity of the composition and making the coating obtained by applying the composition flatter. Specifically, a surfactant may be mentioned. As the leveling agent, at least one selected from the group consisting of a leveling agent with a polyacrylate compound as a main component and a leveling agent with a compound containing a fluorine atom as a main component is preferred. The leveling agent may be used alone or in combination of two or more.

[0117] When the composition includes a leveling agent, the content of the leveling agent is preferably 0.05 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, relative to the total amount of 100 parts by mass of the polymerizable liquid crystal compound and the liquid crystal polymer compound. If the content of the leveling agent is within the above range, it is easy to horizontally align the polymerizable liquid crystal compound and the liquid crystal polymer compound, and there is a tendency that unevenness is not easy to occur and a smoother film (such as a polarizing film) can be obtained.

[0118] If the content of the leveling agent is within the above range, it is easy to horizontally align the polymerizable liquid crystal compound and the liquid crystal polymer compound, and there is a tendency for the obtained film to become smoother. If the content of the leveling agent relative to the polymerizable liquid crystal compound and the liquid crystal polymer compound exceeds the above range, there is a tendency to easily produce unevenness in the obtained film.

[0119] The composition may contain an antioxidant. As long as the composition can exert the effect of the present invention, there is no particular limitation on the antioxidant, and known antioxidants can be used. From the viewpoint of having a high inhibitory effect on the photodegradation of the azo compound (1), the antioxidant is preferably a so-called primary antioxidant that captures free radicals and thus has the effect of preventing auto-oxidation. Therefore, the antioxidant contained in the composition is more preferably 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.

[0120] The content of the antioxidant in the composition is preferably 0.1 to 15 parts by mass, more preferably 0.3 to 0.5 parts by mass, more preferably 12 parts by mass or less, and more preferably 10 parts by mass or less, relative to 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 more effectively suppressed. In addition, if the content of the antioxidant is below the upper limit, the orientation of the polymerizable liquid crystal compound is less likely to be disturbed, and a higher inhibitory effect on the photodegradation of the azo compound (1) can be expected.

[0121] The composition may contain other additives other than those mentioned above. Examples of other additives include mold release agents, stabilizers, colorants such as bluing agents, flame retardants, and lubricants. When the composition contains other additives, the content of the other additives is preferably greater than 0% and less than 20% by mass, more preferably greater than 0% and less than 10% by mass, relative to the solid content of the composition.

[0122] The composition can be produced by a conventionally known method for producing a composition, for example, by mixing and stirring the azo compound represented by formula (1), a liquid crystal compound, and additives such as an antioxidant and a leveling agent as needed.

[0123] membrane

[0124] The film involved in this 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. The film formed by the composition can be formed by imparting the composition to a substrate and forming a film. In addition, in the case where the composition includes a polymerizable liquid crystal compound, a film containing a cured product obtained by polymerizing the polymerizable liquid crystal compound can be formed by imparting the composition to a substrate, forming a film, and then polymerizing the polymerizable liquid crystal compound to cure it.

[0125] The composition can form a film, such as a polarizing film, which has a high degree of orientation order and suppresses the generation of unevenness due to the difference in absorbance within the plane. Therefore, the film involved in this embodiment includes a polarizing film, which is a polarizing film formed from a composition comprising an azo compound represented by formula (1) and a liquid crystal compound, and the polarizing film has a high degree of orientation order and suppresses the generation of unevenness due to the difference in absorbance within the plane.

[0126] Here, for a polarizing film with a high degree of orientation order, a Bragg peak derived from a higher-order structure such as a hexagonal phase or a crystalline phase can be obtained in an X-ray diffraction measurement. Therefore, for a polarizing film formed by a composition, it is preferred that a polymerizable liquid crystal compound or a liquid crystal polymer compound is oriented in a manner that shows a Bragg peak in an X-ray diffraction measurement, and more preferably a "horizontal orientation" in which the molecules of a polymerizable liquid crystal compound or a liquid crystal polymer compound are oriented in the direction of absorbing light. The orientation order that shows a high degree of 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.

[0127] The azo compound represented by formula (1) and the liquid crystal compound constituting the film-forming composition are as described above.

[0128] The film can be produced, for example, by a method including the following steps.

[0129] Step 1: forming a coating film of a composition comprising an azo compound represented by formula (1), a liquid crystal compound and a solvent;

[0130] Step 2: removing at least a portion of the solvent from the coating film;

[0131] Step 3: raising the temperature to a temperature above the temperature at which the liquid crystal compound undergoes phase transition to a liquid phase, and then lowering the temperature to allow the liquid crystal compound to undergo phase transition to a smectic phase (smectic liquid crystal state); and

[0132] Step 4: If necessary, polymerize the polymerizable liquid crystal compound while maintaining the smectic phase (smectic liquid crystal state).

[0133] The coating film of the composition can be formed by, for example, applying the composition on a substrate, an alignment film described later, etc. Alternatively, the composition may be directly applied on a retardation film or other layers constituting a polarizing plate.

[0134] The substrate is usually a transparent substrate. It should be noted that when the substrate is not disposed on the display surface of the display element, for example, when a laminate obtained by removing the substrate from the film is disposed on the display surface of the display element, the substrate may not be transparent. The so-called transparent substrate refers to a substrate having transparency that allows light, especially visible light, to pass through, and the so-called transparency refers to a property of having a transmittance of 80% or more relative to light within a wavelength range of 380 nm to 780 nm. As a specific transparent substrate, a translucent resin substrate can be cited.

[0135] Examples of the resin constituting the light-transmitting resin substrate include polyolefins, cyclic olefin resins, polyvinyl alcohol, polyethylene terephthalate, polymethacrylate, polyacrylate, cellulose ester, polyethylene naphthalate, polycarbonate, polysulfone, polyether sulfone, polyether ketone, polyphenylene sulfide, and polyphenylene ether. From the viewpoint of availability and transparency, polyethylene terephthalate, polymethacrylate, cellulose ester, cyclic olefin resin, or polycarbonate is preferred.

[0136] The characteristics required for the substrate vary depending on the composition of the film, but it is generally preferred to use a substrate with as little phase difference as possible. As a substrate with as little phase difference as possible, cellulose ester films such as Zero tack (Konica Minolta Opto Co., Ltd.) and Ztack (Fujifilm Corporation) that do not have a phase difference can be cited. In addition, unstretched cyclic olefin resin substrates are also preferred. Hard coating treatment, anti-reflection treatment, antistatic treatment, etc. can be applied to the surface of the substrate without laminated film.

[0137] The thickness of the substrate is usually 5 μm to 300 μm, preferably 20 μm to 200 μm, and more preferably 20 μm to 100 μm. When it is at least the lower limit, a decrease in strength is suppressed and workability tends to be good.

[0138] Examples of a method for applying the composition to a substrate include known methods such as spin coating, extrusion, gravure coating, die coating, bar coating, and applicator coating, and printing methods such as flexographic printing.

[0139] Next, at least a portion of the solvent contained in the coating film obtained by the composition is removed by drying, etc., thereby forming a dried coating film. In addition, when a polymerizable liquid crystal compound is included in the coating film, a dried coating film is formed by drying under conditions where the polymerizable liquid crystal compound does not polymerize. As the drying method of the aforementioned coating film, natural drying, ventilation drying, heating drying, reduced pressure drying, etc. can be cited.

[0140] In addition, in order to make the liquid crystal compound phase transition to the liquid phase, the temperature is raised to a temperature above the temperature at which the liquid crystal compound phase transitions to the liquid phase, and then the temperature is lowered to make the liquid crystal compound phase transition to the smectic phase (smectic liquid crystal state). The phase transition can be performed after removing the solvent in the coating film, or it can be performed simultaneously with the removal of the solvent.

[0141] In the case where the composition includes 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 of a cured product containing the polymerizable liquid crystal compound. As a polymerization method, photopolymerization is preferably used. In photopolymerization, as the light irradiated to the dry coating, it can be appropriately selected according to the type of photopolymerization initiator contained in the dry coating, the type of polymerizable liquid crystal compound (especially the type of polymerizable group possessed by the polymerizable liquid crystal compound) and its amount. As a specific example thereof, one or more light selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α rays, β rays and γ rays, active electron rays, etc. can be cited. Among them, from the aspect of easily controlling the progress of the polymerization reaction, it is possible to use a device that is widely used in this field as a photopolymerization device, preferably ultraviolet light, preferably in a way that can be photopolymerized using ultraviolet light, the type of polymerizable liquid crystal compound and photopolymerization initiator contained in the composition, etc. are selected in advance. In addition, during polymerization, light irradiation can also be performed while the dry coating is cooled using a suitable cooling means, thereby controlling the polymerization temperature. If the polymerizable liquid crystal compound is polymerized at a lower temperature by using such cooling means, a film can be suitably formed even when a substrate with low heat resistance is used. During photopolymerization, a patterned film can also be obtained by performing masking, development, etc.

[0142] As the light source of the aforementioned active energy rays, for example, there can be mentioned 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 that emits light in a wavelength range of not less than 380 nm and not more than 440 nm, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, a metal halide lamp, and the like.

[0143] The UV radiation intensity can usually be 10mW / cm 2 Above 3,000mW / cm 2 The ultraviolet irradiation intensity is preferably an intensity in a wavelength region effective for activating the photopolymerization initiator. The irradiation time can generally be 0.1 second to 10 minutes, preferably 0.1 second to 5 minutes, more preferably 0.1 second to 3 minutes, and further preferably 0.1 second to 1 minute. When irradiating once or more times with such an ultraviolet irradiation intensity, the cumulative light amount is preferably 10 mJ / cm 2Above 3,000mJ / cm 2 the following.

[0144] By photopolymerization, the polymerizable liquid crystal compound is polymerized while maintaining a liquid crystal state of a smectic phase, preferably a higher-order smectic phase, to form a film. The film obtained by polymerizing the polymerizable liquid crystal compound while maintaining a liquid crystal state of a smectic phase is also accompanied by the effect of a dichroic pigment, and thus has the advantage of high polarization performance compared to a conventional guest-host polarizing film, that is, a film formed by a liquid crystal state of a nematic phase. In addition, it also has the advantage of excellent strength compared to a film coated only with a dichroic pigment or a lyotropic liquid crystal.

[0145] The thickness of the film can be appropriately selected depending on the display device etc. to which it is applied, and is preferably 0.5 μm to 10 μm, more preferably 1 μm to 5 μm, and further preferably 1 μm to 3 μm.

[0146] When the film is used as a polarizing film, it is preferably formed on an alignment film. An alignment film is a film with an alignment control force that allows a polymerizable liquid crystal compound and a liquid crystal polymer compound to be oriented in a desired direction. As an alignment film, it is preferably a film having solvent resistance that does not dissolve due to the coating of a composition containing at least one liquid crystal compound of a polymerizable liquid crystal compound and a liquid crystal polymer compound, and having heat resistance in a heating treatment for the removal of a solvent and the orientation of a polymerizable liquid crystal compound. As the alignment film, an alignment film containing an oriented polymer, a photo-aligned film, and a groove-aligned film having a concave-convex pattern and a plurality of grooves on the surface can be cited. From the perspective of the accuracy and quality of the orientation angle, a photo-aligned film is preferably used.

[0147] Laminated body

[0148] The laminate involved in this embodiment may have a film containing an azo compound represented by formula (1) as a forming material, or may have a film containing an azo compound represented by formula (1) and a liquid crystal compound as a forming material. The laminate may have a substrate, and a film containing an azo compound represented by formula (1) as a forming material disposed on the substrate, or may have a substrate, an oriented film disposed on the substrate, and a film containing an azo compound represented by formula (1) as a forming material disposed on the oriented film. The film containing an azo compound represented by formula (1) as a forming material may constitute a polarizing film. In addition, the substrate may also be a phase difference film. The laminate may, for example, constitute a polarizing plate. The laminate may, for example, be manufactured by forming a film on a substrate according to the above-mentioned film manufacturing method.

[0149] From the viewpoint of the bendability 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 further preferably 25 μm to 100 μm.

[0150] When the laminated body includes a retardation film as a substrate, the thickness of the retardation film can be appropriately selected according to the display device to be applied.

[0151] Display device

[0152] The display device of the present embodiment has the aforementioned laminate, and the laminate can be a polarizing plate. The display device can be obtained, for example, by attaching the laminate as a polarizing plate to the surface of the display device via an adhesive layer. The so-called display device is a device having a display element, and is a device comprising a light-emitting element or a light-emitting device as a light source. As a display device, for example, a liquid crystal display device, an organic electroluminescent (EL) display device, an inorganic electroluminescent (EL) display device, an electron emission display device (for example, a field emission display device (FED), a surface field emission display device (SED)), an electronic paper (a display device using electronic ink, an electrophoretic element, etc.), a plasma display device, a projection type display device (for example, a grating light valve (GLV) display device, a display device having a digital micromirror device (D MD)), and a piezoelectric ceramic display, etc. The liquid crystal display device includes any device in 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 type liquid crystal display device. These display devices may be display devices that display two-dimensional images or stereoscopic display devices that display three-dimensional images. In particular, as the display device, an organic EL display device and a touch panel display device are preferred, and an organic EL display device is particularly preferred.

[0153] Example

[0154] Hereinafter, the present invention will be specifically described by way of Examples, but the present invention is not limited to these Examples.

[0155] First, compound (1-1-a) is synthesized by a known diazo coupling method.

[0156] Synthesis Example 1: Synthesis of Compound (1-1)

[0157] 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. Saturated sodium bicarbonate aqueous solution was added to the reaction container, and the precipitated solid was separated by filtration and washed with methanol. The obtained solid was purified by silica gel column chromatography using chloroform as the developing solvent to obtain compound (1-1) (0.171 g, yield of 43%).

[0158] [Chemical formula 10]

[0159]

[0160] 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)

[0161] Synthesis Example 2: Synthesis of Compound (1-2)

[0162] 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. Saturated sodium bicarbonate aqueous solution was added to the reaction container, and the precipitated solid was separated by filtration and washed with methanol. The obtained solid was purified by silica gel column chromatography using chloroform as the developing solvent to obtain compound (1-2) (0.256 g, yield of 61%).

[0163] [Chemical formula 11]

[0164]

[0165] 1H-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)

[0166] Comparative Synthesis Example 1: Synthesis of Compound (2-1)

[0167] 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. Saturated sodium bicarbonate aqueous solution was added to the reaction container, and the precipitated solid was separated by filtration and washed with methanol. The obtained solid was purified by silica gel column chromatography using chloroform as the developing solvent to obtain compound (2-1) (0.049 g, yield was 21%).

[0168] [Chemical formula 12]

[0169]

[0170] 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)

[0171] Example 1: Preparation of composition E1 containing compound (1-1)

[0172] The following components were mixed and stirred at 90° C. for 1 hour to obtain composition E1.

[0173]

[0174] Dipentaerythritol hexaacrylate

[0175] (Manufactured by DAICEL-CYTEC COMPANY, LTD.)

[0176] ·6 parts by mass of polymerization initiator

[0177] 2-Dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (IRGAC URE 369; manufactured by BASF Japan Ltd.)

[0178] · Leveling agent 1.2 parts by mass

[0179] Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)

[0180] Solvent: 250 parts by mass of toluene

[0181] The structures of the polymerizable liquid crystal compounds are as follows: It should be noted that 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).

[0182] [Chemical formula 13]

[0183]

[0184] Using the composition E1 obtained above, a polarizing film was prepared as follows to obtain a laminate.

[0185] Formation of polarizing film

[0186] The composition for forming a photo-alignment film was applied to a glass substrate and dried at 120°C to obtain a dry coating film. The dry coating film was irradiated with polarized UV light to form a photo-alignment film, thereby obtaining glass with a photo-alignment film. The irradiation with polarized UV light was performed using a UV irradiation device (SPOT CURE SP-7; USHIO Inc.) under the condition that the intensity measured at a wavelength of 365 nm was 100 mJ.

[0187] Composition E1 was applied to a glass with a photo-alignment film by spin coating, dried on a hot plate at 120°C for 1 minute, and then rapidly cooled to room temperature to form a dry coating on the alignment film. Next, a UV irradiation device (SPOTCURE SP-7; manufactured by USHIO Inc.) was used at an exposure dose of 2000 mJ / cm 2The film was irradiated with ultraviolet light at 313 nm (based on 313 nm) to polymerize the polymerizable liquid crystal compound contained in the dry film, and a polarizing film was formed from the dry 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.

[0188] Example 2: Preparation of composition E2 containing compound (1-2)

[0189] Composition E2 was obtained in the same manner as in Example 1 except that compound (1-2) was used instead of compound (1-1). Using the obtained composition E2, a polarizing film was prepared in the same manner as above to obtain a laminate.

[0190] Comparative Example 1: Preparation of Composition C1 Containing Compound (2-1)

[0191] Composition C1 was obtained in the same manner as in Example 1 except that compound (2-1) was used instead of compound (1-1). Using the obtained composition C1, a polarizing film was prepared in the same manner as above to obtain a laminate.

[0192] evaluate

[0193] 1. Uneven evaluation

[0194] For the laminate obtained above, the unevenness of the polarizing film is evaluated as described below. Using a device formed by installing a bracket with a laminate on a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation), the absorbance (A1) in the absorption direction at the maximum absorption wavelength (λmax) of the polarizing film of the laminate is measured by a double beam method. Using the same measurement method as the above method, the position of the laminate is randomly changed, and the absorbance (A1) in the absorption direction at the maximum absorption wavelength (λmax) of a total of 4 points is measured. The minimum value is subtracted from the maximum value of the measured absorbance and the resulting value is taken as the absorbance difference. The results are shown in Table 1. It should be noted that when the absorbance difference is less than 0.05, it is judged that it improves the unevenness as a polarizing plate and is good.

[0195] 2. Evaluation of dichroic ratio

[0196] For the laminate obtained above, the dichroic ratio was measured as described below. Using a device in which a bracket equipped with a laminate was installed on a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation), the absorbance in the transmission axis direction (A1) and the absorbance in the absorption axis direction (A2) of the polarizing film of the laminate at the maximum absorption wavelength (λmax) were measured by a double-beam method. On the bracket, a screen that cuts off 50% of the light is set on the reference side. The ratio (A2 / A1) of the measured absorbance in the absorption axis direction (A2) to the absorbance in the transmission axis direction (A1) is calculated as the dichroic ratio (DR). The results are shown in Table 1. It should be noted that - in the table means not evaluated.

[0197] [Table 1]

[0198] Compound Absorbance difference Dichroic Ratio Example 1 1-1 0.005 55 Example 2 1-2 0.026 48 Comparative Example 1 2-1 0.059 -

[0199] According to Table 1, the polarizing plate having a film formed of a composition containing compound (1-1) or compound (1-2) has no absorbance difference within the plane and can form a high-quality film with less unevenness. In addition, it can be seen that in the case of compound (1-1) having a shorter side chain length, the characteristics are better when used as a polarizing plate.

Claims

1. An azo compound represented by the following formula (1), [Chemical formula 14] 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 which may have a substituent, Ar 1 ,Ar 2 and Ar 3 At least one of them represents a divalent heterocyclic group which is formed by condensing two sulfur-containing aromatic rings and which may have a substituent; R 2 and R 3 Each independently represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms which may have a substituent; R 2 With R 3 They can also be connected to form an aliphatic ring, forming R 2 or R 3 A portion of the methylene groups of the aliphatic hydrocarbon groups represented by may be replaced by oxygen atoms or carbonyl groups; R S represents an aliphatic hydrocarbon group having 4 to 12 carbon atoms which may have a substituent; R L represents a carbon atom number ratio R S An aliphatic hydrocarbon group having a large number of carbon atoms; Choose from R 2 , R 3 , R S and R L At least one of the groups may have a polymerizable group; L represents a linking group consisting 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; k represents 1 or 2. When k is 2, two Ar 2 Each may be the same or different.

2. The compound according to claim 1, wherein In the above formula (1), L is represented by the following formula (1a): [Chemical formula 15] 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(=O)-, -C(=O)O- or -S-; x and y each independently represent a number from 0 to 4; * represents a bonding position.

3. The compound according to claim 1, wherein In the formula (1), Ar 1 and Ar 3 It represents a 1,4-phenylene group which may have a substituent.

4. The compound according to claim 1, wherein In the formula (1), Ar 2 represents a thieno[3,2-d]thiazoldiyl group or a thieno[3,2-d]thiophenediyl group which may have a substituent, and k is 1. 5 . A composition comprising the azo compound according to claim 1 , and a liquid crystal compound, wherein the liquid crystal compound comprises 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 of 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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