Photo-oriented copolymers, photo-oriented films and optical laminates

Abstract

The objective of this invention is to provide a photo-alignment copolymer capable of producing a photo-alignment film with excellent solvent resistance and liquid crystal alignment, and a photo-alignment film and optical laminate made using the photo-alignment copolymer. The photo-alignment copolymer of this invention is a photo-alignment copolymer having repeating unit A comprising a photo-alignment group represented by the following formula (A) and repeating unit B comprising a crosslinking group represented by the following formula (B).

Description

Technical Field

[0001] This invention relates to a photo-oriented copolymer, a photo-oriented film, and an optical laminate. Background Technology

[0002] From the perspective of eliminating image color distortion and magnifying viewing angle, optical films such as optical compensation sheets and phase difference films are used in various image display devices.

[0003] Stretched birefringent films are used as optical films, but in recent years, optical anisotropic layers have been proposed as an alternative to stretched birefringent films. These optical anisotropic layers use liquid crystal compounds.

[0004] Regarding such an optically anisotropic layer, it is known that an alignment film is provided on the support on which the optically anisotropic layer is formed in order to orient the liquid crystal compound, and as such an alignment film, an optically aligned film that has undergone optical alignment treatment instead of rubbing treatment is known.

[0005] For example, Patent Document 1 describes a composition for photo-aligning film containing a polymer A having a constituent unit a1 containing a cinnamic acid ester group and a low molecular weight compound B having a cinnamic acid ester group and a molecular weight smaller than that of polymer A ([Claim 1]), and describes that polymer A has a constituent unit a2 containing crosslinking groups such as epoxy group and oxetyl group (

[0024] to

[0028] ).

[0006] Previous technical documents

[0007] Patent documents

[0008] Patent Document 1: International Publication No. 2017 / 069252 Summary of the Invention

[0009] The technical problem to be solved by the invention

[0010] As for polymer A described in Patent Document 1, the inventors studied a copolymer having both a constituent unit a1 containing a cinnamic acid ester group and a constituent unit a2 containing a crosslinking group. The results showed that when an optically anisotropic layer is formed on the obtained optically aligned film, the orientation of the optically aligned film can sometimes be interfered with depending on the type of solvent used, and the orientation of the liquid crystal compound (hereinafter also referred to as "liquid crystal orientation") can sometimes deteriorate depending on the timing of forming the optically anisotropic layer.

[0011] Therefore, the objective of this invention is to provide a photo-alignment copolymer capable of producing a photo-alignment film with excellent solvent resistance and liquid crystal alignment, and a photo-alignment film and optical laminate made using the photo-alignment copolymer.

[0012] means for solving technical problems

[0013] As a result of in-depth research conducted by the inventors to achieve the above-mentioned problem, they discovered that the photo-alignment film obtained by using a copolymer having repeating units containing specific photo-alignment groups and repeating units containing crosslinking groups has improved solvent resistance and liquid crystal alignment, thus completing the present invention.

[0014] That is, the inventors have discovered that the above-mentioned problem can be achieved by the following configuration.

[0015] [1] A photooriented copolymer having a repeating unit A comprising a photooriented group represented by the following formula (A) and a repeating unit B comprising a crosslinking group represented by the following formula (B).

[0016] [Chemical Formula 1]

[0017]

[0018] In the above formula (A), R 1 This indicates a hydrogen atom or a methyl group. L 1 R represents a divalent linker containing a nitrogen atom and a cycloalkane ring, wherein a portion of the carbon atom constituting the cycloalkane ring can be substituted by a heteroatom selected from the group consisting of nitrogen, oxygen, and sulfur. 2 R 3 R 4 R 5 and R 6 Each can independently represent a hydrogen atom or a substituent, R 2 R 3 R 4 R 5 and R 6 Two adjacent groups can bond together to form a ring.

[0019] In equation (B) above, R 7 L represents a hydrogen atom or a methyl group. 2 This indicates a divalent linker, and X indicates a crosslinking group.

[0020] [2] According to the photo-oriented copolymer of [1], wherein X in the above formula (B) is at least one crosslinking group selected from the group consisting of the following formulas (X1) to (X4).

[0021] [Chemical Formula 2]

[0022]

[0023] In the above equations (X1) to (X4), * indicates L in equation (B) above. 2 The bonding position, R 8S represents any one of hydrogen atom, methyl, and ethyl. In the above formula (X4), S represents a functional group having an alkene unsaturated double bond.

[0024] [3] According to the photo-oriented copolymer described in [2], wherein the repeating unit B comprises repeating units in which X in the above formula (B) is a crosslinking group represented by any one of the above formulas (X1) to (X3) and repeating units in which X in the above formula (B) is a crosslinking group represented by the above formula (X4).

[0025] [4] The photo-oriented copolymer according to any one of [1] to [3], wherein L in the above formula (B) 2 Each is independently a divalent linker composed of at least two groups selected from the group consisting of straight-chain, branched, or cyclic alkylene groups having 1 to 18 carbon atoms that may have substituents, aryl, ether, or carbonyl groups having 6 to 12 carbon atoms that may have substituents, and imino groups that may have substituents.

[0026] [5] A photooriented copolymer according to any one of [1] to [4], wherein L in the above formula (A) 1 Let be a divalent linker represented by any one of the following equations (1) to (10).

[0027] [Chemical Formula 3]

[0028]

[0029] In the above formulas (1) to (10), *1 represents the bonding position with the carbon atom constituting the main chain in formula (A) above, and *2 represents the bonding position with the carbon atom constituting the carbonyl group in formula (A) above.

[0030] [6] According to the photo-oriented copolymer described in [5], wherein L in the above formula (A) 1 Let be a 2-valent linker base represented by any one of the above equations (2), (3), (7) and (8).

[0031] [7] A photooriented copolymer according to any one of [1] to [6], wherein R in the above formula (A) 2 R 3 R 4 R 5 and R 6 In, at least R 4 Indicates a substituent.

[0032] [8] According to the photo-oriented copolymer described in [7], wherein R in the above formula (A) is... 2 R 3 R 5 and R6 Both represent hydrogen atoms.

[0033] [9] According to the photo-oriented copolymer described in [7] or [8], wherein R in the above formula (A) 4 It is an electron-donating substituent.

[0034]

[10] According to the photo-oriented copolymer described in [9], wherein R in the above formula (A) is... 4 It is an alkoxy group with 6 to 16 carbon atoms.

[0035]

[11] The photo-oriented copolymer according to any one of [1] to

[10] , wherein R in the above formula (A) 2 R 3 R 4 R 5 and R 6 The substituents represented are, independently, halogen atoms, straight-chain, branched or cyclic alkyl groups having 1 to 20 carbon atoms, straight-chain haloalkyl groups having 1 to 20 carbon atoms, alkoxy groups having 1 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, aryloxy groups having 6 to 20 carbon atoms, cyano, amino, or groups represented by the following formula (11).

[0036] [Chemical Formula 4]

[0037]

[0038] In equation (11) above, * indicates the bonding position with the benzene ring in equation (A) above, R 9 It represents a monovalent organic group.

[0039]

[12] The photooriented copolymer according to any one of [1] to

[11] , wherein the content a of repeating unit A and the content b of repeating unit B satisfy the following formula (12) by mass ratio.

[0040] 0.03≤a / (a+b)≤0.5…(12)

[0041]

[13] According to the photo-oriented copolymer of

[12] , the content a of repeating unit A and the content b of repeating unit B satisfy the following formula (13) by mass ratio.

[0042] 0.03≤a / (a+b)≤0.3…(13)

[0043]

[14] According to the photo-oriented copolymer of

[12] , the content a of repeating unit A and the content b of repeating unit B satisfy the following formula (14) by mass ratio.

[0044] 0.03≤a / (a+b)≤0.2…(14)

[0045]

[15] The photooriented copolymer according to any one of [1] to

[14] , wherein the weight-average molecular weight is 10,000 to 500,000.

[0046]

[16] The photo-oriented copolymer according to

[15] , wherein the weight-average molecular weight is 30,000 to 300,000.

[0047]

[17] A photo-alignment film formed using a photo-alignment film composition containing any one of the photo-alignment copolymers described in [1] to

[16] .

[0048]

[18] An optical laminate having the optical alignment film described in

[17] and an optical anisotropy layer formed using a liquid crystal composition containing a liquid crystal compound.

[0049] Invention Effects

[0050] According to the present invention, a photo-alignment copolymer capable of producing a photo-alignment film with excellent solvent resistance and liquid crystal alignment is provided, as well as a photo-alignment film and an optical laminate made using the photo-alignment copolymer. Detailed Implementation

[0051] The present invention will now be described in detail.

[0052] The following description of the constituent elements is sometimes based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0053] In addition, in this specification, the numerical range indicated by “~” refers to the range included by taking the values ​​recorded before and after “~” as the lower limit and upper limit values.

[0054] [Photooriented copolymer]

[0055] The photooriented copolymer of the present invention is a photooriented copolymer having a repeating unit A comprising a photooriented group represented by the following formula (A) and a repeating unit B comprising a crosslinking group represented by the following formula (B).

[0056] [Chemical Formula 5]

[0057]

[0058] In the above formula (A), R 1 This indicates a hydrogen atom or a methyl group. L 1 R represents a divalent linker containing a nitrogen atom and a cycloalkane ring, wherein a portion of the carbon atom constituting the cycloalkane ring can be substituted by a heteroatom selected from the group consisting of nitrogen, oxygen, and sulfur. 2 R 3 R4 R 5 and R 6 Each can independently represent a hydrogen atom or a substituent, R 2 R 3 R 4 R 5 and R 6 Two adjacent groups can bond together to form a ring.

[0059] In equation (B) above, R 7 L represents a hydrogen atom or a methyl group. 2 This indicates a divalent linker, and X indicates a crosslinking group.

[0060] In this invention, the solvent resistance and liquid crystal alignment of the photo-aligned film obtained by using a photo-aligned copolymer having a repeating unit A containing a photo-aligning group represented by the above formula (A) and a repeating unit B containing a crosslinking group represented by the above formula (B) are improved.

[0061] The exact reasons are unclear, but the inventors speculate as follows.

[0062] That is, it is assumed that L in the above formula (A) 1 The divalent linker represents a nitrogen atom and a cycloalkane ring, which increases hydrogen bonding and molecular rigidity, thereby suppressing molecular motion and improving solvent resistance.

[0063] Similarly, it is believed that L in the above equation (A) 1 The divalent linker represents nitrogen atoms and cycloalkane rings, thereby increasing the glass transition temperature of the copolymer and improving the time stability of the resulting optically aligned film. As a result, the liquid crystal alignment becomes better regardless of the timing of forming the optically anisotropic layer.

[0064] Next, regarding L in the above formula (A) 1 The divalent linker containing a nitrogen atom and a cycloalkane ring is described. Furthermore, in this invention, as described above, a portion of the carbon atom constituting the cycloalkane ring can be substituted with a heteroatom selected from the group consisting of nitrogen, oxygen, and sulfur. Moreover, when a portion of the carbon atom constituting the cycloalkane ring is substituted with a nitrogen atom, a nitrogen atom may be present in addition to the cycloalkane ring.

[0065] Furthermore, L in the above formula (A) 1 The cycloalkane ring contained in the divalent linker is preferably a cycloalkane ring with 6 or more carbon atoms. Specific examples include cyclohexane ring, cycloheptane ring, cyclooctane ring, cyclododecane ring, and cyclododecane ring.

[0066] In this invention, considering the good change in liquid crystal alignment, L in the above formula (A) is preferred.1 Let be a divalent linker represented by any one of the following equations (1) to (10).

[0067] [Chemical Formula 6]

[0068]

[0069] In the above formulas (1) to (10), *1 represents the bonding position with the carbon atom constituting the main chain in formula (A) above, and *2 represents the bonding position with the carbon atom constituting the carbonyl group in formula (A) above.

[0070] Among the divalent linkers represented by any one of the above formulas (1) to (10), from the perspective of achieving a better balance between the solubility of the solvent used in forming the photo-alignment film and the solvent resistance of the resulting photo-alignment film, the divalent linker represented by any one of the above formulas (2), (3), (7) and (8) is preferred.

[0071] Next, regarding R in the above formula (A) 2 R 3 R 4 R 5 and R 6 The substituents represented in one manner will be explained. Furthermore, R in the above formula (A) will be... 2 R 3 R 4 R 5 and R 6 The case where it can be a hydrogen atom instead of a substituent is as described above.

[0072] Considering the ease with which photo-orientation groups interact with liquid crystal compounds and the favorable alteration of liquid crystal orientation, R in the above formula (A) 2 R 3 R 4 R 5 and R 6 The substituents represented in one manner are preferably, independently, a halogen atom, a straight-chain, branched or cyclic alkyl group having 1 to 20 carbon atoms, a straight-chain haloalkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, a cyano group, an amino group or a group represented by the following formula (11).

[0073] [Chemical Formula 7]

[0074]

[0075] In equation (11) above, * represents the bonding position with the benzene ring in equation (A) above, R 9 It represents a monovalent organic group.

[0076] Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms, with fluorine and chlorine atoms being preferred.

[0077] Regarding straight-chain, branched, or cyclic alkyl groups having 1 to 20 carbon atoms, alkyl groups having 1 to 6 carbon atoms are preferred as straight-chain alkyl groups. Specifically, examples include methyl, ethyl, and n-propyl.

[0078] As a branched alkyl group, an alkyl group having 3 to 6 carbon atoms is preferred; specifically, isopropyl, tert-butyl, etc. are examples.

[0079] As a cyclic alkyl group, alkyl groups with 3 to 6 carbon atoms are preferred, and examples include cyclopropyl, cyclopentyl, and cyclohexyl.

[0080] As a straight-chain halogenated alkyl group having 1 to 20 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms is preferred. Specifically, examples include trifluoromethyl, perfluoroethyl, perfluoropropyl, and perfluorobutyl, among which trifluoromethyl is preferred.

[0081] As an alkoxy group having 1 to 20 carbon atoms, an alkoxy group having 1 to 18 carbon atoms is preferred, an alkoxy group having 6 to 18 carbon atoms is more preferred, and an alkoxy group having 6 to 14 carbon atoms is even more preferred. Specifically, examples of methoxy, ethoxy, n-butoxy, methoxyethoxy, n-hexyloxy, n-octyloxy, n-decyloxy, n-dodecyloxy, and n-tetradecyloxy are preferred, among which n-hexyloxy, n-octyloxy, n-decyloxy, n-dodecyloxy, and n-tetradecyloxy are more preferred.

[0082] As an aryl group having 6 to 20 carbon atoms, an aryl group having 6 to 12 carbon atoms is preferred. Specifically, examples include phenyl, α-methylphenyl, and naphthyl, among which phenyl is preferred.

[0083] As an aryloxy group with 6 to 20 carbon atoms, an aryloxy group with 6 to 12 carbon atoms is preferred. Specifically, examples include phenoxy and 2-naphthoxy, among which phenoxy is preferred.

[0084] Examples of amino groups include primary amino groups (-NH2); secondary amino groups such as methylamino groups; and tertiary amino groups such as dimethylamino, diethylamino, dibenzylamino, and groups in which the nitrogen atom of a nitrogen-containing heterocyclic compound (e.g., pyrrolidine, piperidine, piperazine, etc.) is used as a bonding bond.

[0085] Regarding the group represented by the above formula (11), as R in the above formula (11) 9 The monovalent organic group represented can be, for example, a straight-chain or cyclic alkyl group having 1 to 20 carbon atoms.

[0086] As a straight-chain alkyl group, an alkyl group having 1 to 6 carbon atoms is preferred. Specifically, examples include methyl, ethyl, and n-propyl, among which methyl or ethyl is preferred.

[0087] As a cyclic alkyl group, an alkyl group having 3 to 6 carbon atoms is preferred. Specifically, examples include cyclopropyl, cyclopentyl, and cyclohexyl, among which cyclohexyl is preferred.

[0088] Additionally, R in the above equation (11) 9 The monovalent organic group represented can be a group formed by directly or through the combination of multiple straight-chain alkyl and cyclic alkyl groups via single bonds.

[0089] In this invention, considering that the photo-orientation group readily interacts with the liquid crystal compound and that the liquid crystal orientation is well modified, R in the above formula (A) is preferred. 2 R 3 R 4 R 5 and R 6 In, at least R 4 Considering the above-mentioned substituents, and the fact that the linearity of the resulting photo-oriented copolymer is improved, it readily interacts with liquid crystal compounds, and the liquid crystal orientation is well modified, R is more preferred. 2 R 3 R 5 and R 6 Both represent hydrogen atoms.

[0090] In this invention, considering the improved reaction efficiency when the obtained photo-alignment film is irradiated with light, R in the above formula (A) is preferred. 4 It is an electron-donating substituent.

[0091] Among them, electron-donating substituents (electron-donating groups) refer to substituents with a Hammett value (Hammett substituent constant σp) of 0 or less, such as alkyl, halogenated alkyl, alkoxy, etc.

[0092] Among these, alkoxy groups are preferred, and from the perspective of good liquid crystal orientation change, alkoxy groups with 6 to 16 carbon atoms are more preferred, and alkoxy groups with 7 to 10 carbon atoms are even more preferred.

[0093] Next, regarding L in the above formula (B) 2 The divalent linker is explained.

[0094] As a divalent linker, considering that the photo-orientation group can easily interact with the liquid crystal compound and the liquid crystal orientation is well modified, it is preferable to form a divalent linker composed of at least two groups selected from the group consisting of linear, branched or cyclic alkylene groups having 1 to 18 carbon atoms that may have substituents, arylene groups having 6 to 12 carbon atoms that may have substituents, ether groups (-O-), carbonyl groups (-C(=O)-), and imino groups (-NH-) that may have substituents.

[0095] Among them, substituents that can be present in alkylene, arylene and imino groups include, for example, halogen atoms, alkyl, alkoxy, aryl, aryloxy, cyano, carboxyl, alkoxycarbonyl and hydroxyl groups.

[0096] Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms, with fluorine and chlorine atoms being preferred.

[0097] As an alkyl group, linear, branched, or cyclic alkyl groups having 1 to 18 carbon atoms are preferred, alkyl groups having 1 to 8 carbon atoms (e.g., methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclohexyl, etc.) are more preferred, alkyl groups having 1 to 4 carbon atoms are even more preferred, and methyl or ethyl groups are particularly preferred.

[0098] As an alkoxy group, an alkoxy group having 1 to 18 carbon atoms is preferred, an alkoxy group having 1 to 8 carbon atoms (e.g., methoxy, ethoxy, n-butoxy, methoxyethoxy, etc.) is more preferred, an alkoxy group having 1 to 4 carbon atoms is even more preferred, and methoxy or ethoxy is particularly preferred.

[0099] Examples of aryl groups include those with 6 to 12 carbon atoms, specifically phenyl, α-methylphenyl, naphthyl, etc., with phenyl being preferred.

[0100] Examples of aryloxy groups include phenoxy, naphthoxy, imidazoleoxy, benzimidazoleoxy, pyridin-4-yloxy, pyrimidinyloxy, quinazolinyloxy, purinyloxy, thiophene-3-yloxy, etc.

[0101] Examples of alkoxycarbonyl groups include methoxycarbonyl and ethoxycarbonyl.

[0102] Regarding linear, branched, or cyclic alkylene groups having 1 to 18 carbon atoms, examples of linear alkylene groups include, for instance, methylene, ethylene, propylene, butylene, pentylene, hexylene, decylene, undecylene, dodecylene, tridecylene, tetradecylene, pentadecylene, hexadecylene, heptadecanylene, octadecylene, etc.

[0103] Furthermore, as branched alkylene compounds, examples include dimethylmethylene, methylethylene, 2,2-dimethylpropylene, and 2-ethyl-2-methylpropylene.

[0104] Furthermore, examples of cyclic alkylene compounds include cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, cyclooctylene, cyclodecylene, adamantane-diyl, norcamphene-diyl, and tetrahydrodicyclopentadiene-diyl, with cyclohexylene being preferred.

[0105] As an arylene group having 6 to 12 carbon atoms, examples include phenylene, xylene, biphenylene, naphthylene, 2,2'-methylenebisphenyl, etc., with phenylene being preferred.

[0106] Next, the crosslinking group represented by X in the above formula (B) will be explained.

[0107] As X (crosslinking group) in the above formula (B), examples include epoxy group, epoxycyclohexyl group, oxocyclobutyl group and functional groups having olefinic unsaturated double bonds, wherein at least one crosslinking group selected from the group consisting of the following formulas (X1) to (X4) is preferred.

[0108] [Chemical Formula 8]

[0109]

[0110] In the above equations (X1) to (X4), * indicates L in equation (B) above. 2 The bonding position, R 8 S represents any one of hydrogen atom, methyl, and ethyl. In the above formula (X4), S represents a functional group having an alkene unsaturated double bond.

[0111] Among them, the functional group having an olefinic unsaturated double bond can be, for example, vinyl, allyl, styryl, acryloyl, methacryloyl, preferably acryloyl or methacryloyl.

[0112] In this invention, considering the increased strength of the optical laminate described later and the improved operability when forming other layers using the optical laminate described later, it is preferable that the repeating unit B includes a repeating unit (hereinafter also simply referred to as "repeating unit B1") in which X in the above formula (B) is a crosslinking group represented by any one of the above formulas (X1) to (X3) and a repeating unit (hereinafter also simply referred to as "repeating unit B2") in which X in the above formula (B) is a crosslinking group represented by the above formula (X4).

[0113] As a repeating unit A comprising a photo-orienting group represented by the above formula (A), examples of repeating units A-1 to A-44 shown below can be cited. Furthermore, in the following formulas, Me represents methyl and Et represents ethyl. Additionally, in the following specific examples, the "1,4-cyclohexyl" contained in the divalent linker of repeating units A-1 to A-10 can be either cis or trans, but trans is preferred.

[0114] [Chemical Formula 9]

[0115]

[0116]

[0117] [Chemical Formula 10]

[0118]

[0119]

[0120] On the other hand, as a repeating unit B (repeating unit B1) containing a crosslinking group represented by the above formula (B), for example, repeating units B-1 to B-17 shown below can be cited.

[0121] [Chemical Formula 11]

[0122]

[0123]

[0124] Furthermore, as a repeating unit B (repeating unit B2) containing a crosslinking group represented by the above formula (B), for example, repeating units B-18 to B-47 shown below can be cited.

[0125] [Chemical Formula 12]

[0126]

[0127] In the photooriented copolymer of the present invention, it is preferable that the content a of the repeating unit A and the content b of the repeating unit B satisfy the following formula (12) by mass ratio, more preferably the following formula (13), even more preferably the following formula (14), and especially preferably the following formula (15).

[0128] 0.03≤a / (a+b)≤0.5…(12)

[0129] 0.03≤a / (a+b)≤0.3…(13)

[0130] 0.03≤a / (a+b)≤0.2…(14)

[0131] 0.05≤a / (a+b)≤0.2…(15)

[0132] Furthermore, when the photo-oriented copolymer of the present invention has the above-mentioned repeating unit B1 and repeating unit B2, while maintaining good liquid crystal orientation and adhesion, the strength of the optical anisotropy layer containing the photo-oriented film is further improved. For this reason, it is preferable that the content a of the above-mentioned repeating unit A, the content b1 of the above-mentioned repeating unit B1 and the content b2 of the above-mentioned repeating unit B2 satisfy the following formula (16) in mass ratio, and more preferably satisfy the following formula (17).

[0133] 0.05≤b2 / (a+b1+b2)≤0.7…(16)

[0134] 0.10≤b2 / (a+b1+b2)≤0.5…(17)

[0135] In addition to the repeating units A and B described above, the photo-oriented copolymer of the present invention may have other repeating units, provided that they do not hinder the effect of the present invention.

[0136] Examples of monomers (free radical polymerizable monomers) that form these other repeating units include acrylate compounds, methacrylate compounds, maleimide compounds, acrylamide compounds, acrylonitrile, maleic anhydride, styrene compounds, vinyl compounds, etc.

[0137] The synthesis method of the photooriented copolymer of the present invention is not particularly limited. For example, it can be synthesized by mixing the monomer that forms the repeating unit A, the monomer that forms the repeating unit B, and the monomer that forms any other repeating unit, and then polymerizing them in an organic solvent using a free radical polymerization initiator.

[0138] Considering the need to further improve the liquid crystal orientation, the weight-average molecular weight (Mw) of the photo-oriented copolymer of the present invention is preferably 10,000 to 500,000, more preferably 30,000 to 300,000.

[0139] In this invention, the weight-average molecular weight and number-average molecular weight are values ​​determined by gel permeation chromatography (GPC) under the conditions shown below.

[0140] • Solvent (eluent): THF (tetrahydrofuran)

[0141] • Device Name: TOSOH HLC-8320GPC

[0142] • String: Connect three TOSOH TSKgel Super HZM-H (4.6mm × 15cm) tubes for use.

[0143] • Column temperature: 40℃

[0144] • Sample concentration: 0.1% by mass

[0145] • Flow rate: 1.0 ml / min

[0146] • Calibration curves: Calibration curves were obtained using seven samples based on TOSOH-prepared TSK standard polystyrene with Mw values ​​ranging from 2,800,000 to 1,050 (Mw / Mn = 1.03 to 1.06).

[0147] [Photoalignment film]

[0148] The photo-alignment film of the present invention is a photo-alignment film formed using a photo-alignment film composition containing the photo-alignment copolymer of the present invention (hereinafter, also referred to in the formal sense as "the photo-alignment film composition of the present invention").

[0149] The thickness of the photo-alignment film is not particularly limited and can be appropriately selected according to the purpose. It is preferably 10 to 1000 nm, and more preferably 10 to 700 nm.

[0150] The content of the photo-oriented copolymer of the present invention in the photo-oriented film composition of the present invention is not particularly limited, but when it contains the organic solvent described later, it is preferably 0.1 to 50 parts by weight, more preferably 0.5 to 10 parts by weight, relative to 100 parts by weight of the organic solvent.

[0151] From the viewpoint of operability in manufacturing photo-alignment films, the photo-alignment film composition of the present invention preferably contains an organic solvent.

[0152] As organic solvents, examples include ketones (e.g., acetone, 2-butanone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, etc.), ethers (e.g., dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (e.g., hexane, etc.), alicyclic hydrocarbons (e.g., cyclohexane, etc.), aromatic hydrocarbons (e.g., toluene, xylene, trimethylbenzene, etc.), carbon halides (e.g., dichloromethane, dichloroethane, dichlorobenzene, chlorotoluene, etc.), esters (e.g., methyl acetate, ethyl acetate, butyl acetate, etc.), water, alcohols (e.g., ethanol, isopropanol, butanol, cyclohexanol, etc.), cellosols (e.g., methyl cellosol, ethyl cellosol, etc.), cellosol acetates, sulfoxides (e.g., dimethyl sulfoxide, etc.), and amides (e.g., dimethylformamide, dimethylacetamide, etc.). One of these solvents can be used alone, or two or more can be used simultaneously.

[0153] The composition for photo-aligned films of the present invention may contain other components besides those described above, such as crosslinking catalysts, adhesion modifiers, leveling agents, surfactants, plasticizers, etc.

[0154] [Manufacturing method of photo-alignment film]

[0155] In addition to using the photoalignment film composition of the present invention described above, the photoalignment film of the present invention can also be manufactured by conventional manufacturing methods, for example, by a manufacturing method comprising a coating step of coating the photoalignment film composition of the present invention onto the surface of a support; and a light irradiation step of irradiating the coating of the photoalignment film composition with polarized light or irradiating the surface of the coating with unpolarized light from an inclined direction.

[0156] Furthermore, the support will be described later in the section on the optical laminate of the present invention.

[0157] <Coating Process>

[0158] There are no particular limitations on the coating method in the coating process; it can be selected appropriately according to the purpose. Examples include spin coating, die coating, gravure coating, flexographic printing, and inkjet printing.

[0159] <Light Irradiation Process>

[0160] In the light irradiation process, there are no particular restrictions on the polarized light irradiating the coating of the composition for photo-alignment film. Examples include linearly polarized light, circularly polarized light, and elliptically polarized light, with linearly polarized light being preferred.

[0161] Furthermore, the “tilt direction” for irradiating unpolarized light refers to any direction that is tilted at a polar angle θ (0 < θ < 90°) relative to the normal direction of the coating surface. There are no particular restrictions, and it can be appropriately selected according to the purpose. Preferably, θ is 20 to 80°.

[0162] The wavelength can be either polarized or unpolarized light, as long as it can impart orientation control over the liquid crystal molecules to the coating of the composition for photoalignment film. Examples include ultraviolet light, near-ultraviolet light, and visible light. Among these, near-ultraviolet light in the range of 250 nm to 450 nm is particularly preferred.

[0163] Furthermore, examples of light sources for irradiating polarized or unpolarized light include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halide lamps. The wavelength range of the irradiated light can be limited by using interference filters or color filters on the ultraviolet or visible light obtained from such light sources. Moreover, linearly polarized light can be obtained by using polarizing films or polarizing prisms on the light from these light sources.

[0164] The cumulative amount of polarized or unpolarized light is not particularly limited as long as it can impart the ability to control the orientation of liquid crystal molecules to the coating of the composition for photoalignment film; preferably, it is 1 to 300 mJ / cm. 2 More preferably 5–100 mJ / cm 2 .

[0165] The illuminance of polarized or unpolarized light is not particularly limited as long as it can impart the ability to control the orientation of liquid crystal molecules to the coating of the composition for photoalignment film; preferably, it is 0.1 to 300 mW / cm. 2 More preferably 1–100 mW / cm 2 .

[0166] [Optical laminate]

[0167] The optical laminate of the present invention is an optical laminate having the optical alignment film of the present invention described above and an optical anisotropy layer formed using a liquid crystal composition containing a liquid crystal compound.

[0168] Furthermore, the optical laminate of the present invention preferably also has a support, specifically, it preferably has a support, an optical alignment film and an optical anisotropy layer in sequence.

[0169] [Optical Anisotropy Layer]

[0170] The optical anisotropic layer of the optical laminate of the present invention is not particularly limited as long as it is an optical anisotropic layer containing a liquid crystal compound, and conventionally known optical anisotropic layers can be appropriately used.

[0171] This optically anisotropic layer is preferably obtained by curing a composition containing a liquid crystal compound with polymerizable groups (hereinafter also referred to as "composition for forming an optically anisotropic layer"), and can be a single-layer structure or a structure with multiple layers (laminated body).

[0172] The following describes the liquid crystal compounds and any additives contained in the composition for forming optical anisotropic layers.

[0173] <Liquid Crystal Compounds>

[0174] The liquid crystal compound contained in the composition for forming an anisotropic optical layer is a liquid crystal compound having polymerizable groups.

[0175] Liquid crystal compounds are generally classified into rod-shaped and disc-shaped types based on their shape. Furthermore, they are categorized into low-molecular-weight and high-molecular-weight types. High-molecular-weight compounds typically refer to substances with a degree of polymerization of 100 or higher (Polymer Physics / Phase Transfer Kinetics, Masao Doi, ed., p. 2, Iwanami Shoten, 1992).

[0176] In this invention, any liquid crystal compound can be used, but rod-shaped or disc-shaped liquid crystal compounds are preferred, and rod-shaped liquid crystal compounds are even more preferred.

[0177] In this invention, a liquid crystal compound having polymerizable groups is used for immobilization of the aforementioned liquid crystal compound; however, it is further preferred that the liquid crystal compound has two or more polymerizable groups per molecule. Furthermore, when the liquid crystal compound is a mixture of two or more types, it is preferable that at least one type of liquid crystal compound has two or more polymerizable groups per molecule. Additionally, after the liquid crystal compound is immobilized by polymerization, it is no longer necessary to exhibit liquid crystal properties.

[0178] Furthermore, there are no particular limitations on the type of polymerizable group, but functional groups capable of undergoing addition polymerization are preferred, and polymerizable olefinic unsaturated groups or ring-opening polymerizable groups are more preferred. More specifically, (meth)acryloyl, vinyl, styrene, allyl, etc., are preferred, and (meth)acryloyl is more preferred. In addition, (meth)acryloyl refers to a designation that represents methacryloyl or acryloyl.

[0179] As a rod-shaped liquid crystal compound, the compound described in claim 1 of Japanese Patent Application Publication No. 11-513019 or in paragraphs

[0026] to

[0098] of Japanese Patent Application Publication No. 2005-289980 is preferred, for example, as a disc-shaped liquid crystal compound, the compound described in paragraphs

[0020] to

[0067] of Japanese Patent Application Publication No. 2007-108732 or in paragraphs

[0013] to

[0108] of Japanese Patent Application Publication No. 2010-244038 is preferred, but it is not limited to these.

[0180] Furthermore, in this invention, a reverse wavelength dispersible liquid crystal compound can be used as the aforementioned liquid crystal compound.

[0181] In this specification, "reverse wavelength dispersibility" liquid crystal compound refers to a liquid crystal compound that, when measuring the in-plane retardation (Re) value of a phase retardation film made using this liquid crystal compound at a specific wavelength (visible light range), has a Re value that is equal to or increases as the measurement wavelength increases.

[0182] Furthermore, as long as a reverse wavelength dispersible film can be formed as described above, the reverse wavelength dispersible liquid crystal compound is not particularly limited. For example, compounds represented by general formula (I) as described in Japanese Patent Application Publication No. 2008-297210 (especially the compounds described in paragraphs

[0034] to

[0039] ), compounds represented by general formula (1) as described in Japanese Patent Application Publication No. 2010-084032 (especially the compounds described in paragraphs

[0067] to

[0073] ), compounds represented by general formula (II) as described in Japanese Patent Application Publication No. 2016-053709 (especially the compounds described in paragraphs

[0036] to

[0043] ), and compounds represented by general formula (1) as described in Japanese Patent Application Publication No. 2016-081035 (especially the compounds described in paragraphs

[0043] to

[0055] ) can be used.

[0183] In particular, as a liquid crystal compound with reverse wavelength dispersion, compounds represented by the following formulas (21) to (32) are preferably cited, and specifically, as K (side chain structure) in the following formulas (21) to (32), compounds having the side chain structures shown in Table 1 and Table 2 are cited respectively.

[0184] Additionally, in Tables 1 and 2 below, the "*" in the side chain structure of K indicates the bonding position with the aromatic ring.

[0185] Furthermore, in the side chain structures represented by 1-2 in Table 1 and 2-2 in Table 2 below, the groups adjacent to acryloyloxy and methacryloyl groups respectively represent propylene groups (groups in which methyl is substituted with ethylidene), and represent a mixture of positional isomers of methyl with different positions.

[0186] [Chemical Formula 13]

[0187]

[0188] [Table 1]

[0189]

[0190] [Table 2]

[0191]

[0192] <Additives>

[0193] The composition for forming an optical anisotropic layer may contain components other than the liquid crystal compound mentioned above.

[0194] For example, compositions for forming optical anisotropic layers may contain polymerization initiators. The polymerization initiator used is selected according to the form of polymerization reaction, and examples include thermal polymerization initiators and photopolymerization initiators. Examples of photopolymerization initiators include α-carbonyl compounds, azo dyes, α-hydrocarbon-substituted aromatic azo dyes, polynuclear quinone compounds, and combinations of triarylimidazolium dimers and p-aminophenyl ketones.

[0195] The amount of polymerization initiator used is preferably 0.01 to 20% by mass relative to the total solids content of the composition, more preferably 0.5 to 5% by mass.

[0196] Furthermore, considering the uniformity and strength of the coating, the composition for forming an optical anisotropic layer may contain polymerizable monomers.

[0197] Examples of polymerizable monomers include free radical polymerizable or cationic polymerizable compounds. Multifunctional free radical polymerizable monomers are preferred, and compounds copolymerized with the aforementioned liquid crystal compounds containing polymerizable groups are more preferred. For example, compounds described in paragraphs

[0018] to

[0020] of Japanese Patent Application Publication No. 2002-296423 can be cited.

[0198] The content of the polymerizable monomer is preferably 1 to 50% by mass relative to the total mass of the liquid crystal compound, more preferably 2 to 30% by mass.

[0199] Furthermore, considering the uniformity and strength of the coating, the composition for forming an optical anisotropic layer may contain a surfactant.

[0200] As surfactants, conventionally known compounds can be cited, with fluorinated compounds being particularly preferred. Specifically, for example, compounds described in paragraphs

[0028] to

[0056] of Japanese Patent Application Publication No. 2001-330725 and compounds described in paragraphs

[0069] to

[0126] of Japanese Patent Application Publication No. 2005-062673 can be cited.

[0201] Furthermore, from the viewpoint of using the optical anisotropic layer as a polarizer, the composition for forming the optical anisotropic layer may contain a dichroic substance.

[0202] The dichroic substances mentioned above are not particularly limited, and examples include visible light absorbing substances (dichroic pigments), luminescent substances (fluorescent substances, phosphorescent substances), ultraviolet light absorbing substances, infrared light absorbing substances, nonlinear optical substances, carbon nanotubes, inorganic substances (such as quantum rods), etc., and conventionally known dichroic substances (dichroic pigments) can be used.

[0203] Specifically, examples include paragraphs

[0067] to

[0071] of Japanese Patent Application Publication No. 2013-228706, paragraphs

[0008] to

[0026] of Japanese Patent Application Publication No. 2013-227532, paragraphs

[0008] to

[0015] of Japanese Patent Application Publication No. 2013-209367, paragraphs

[0045] to

[0058] of Japanese Patent Application Publication No. 2013-014883, paragraphs

[0012] to

[0029] of Japanese Patent Application Publication No. 2013-109090, and Japanese Patent Application Publication No. 2013-1 Paragraphs

[0009] to

[0017] of Japanese Patent Application Publication No. 01328, paragraphs

[0051] to

[0065] of Japanese Patent Application Publication No. 2013-037353, paragraphs

[0049] to

[0073] of Japanese Patent Application Publication No. 2012-063387, paragraphs

[0016] to

[0018] of Japanese Patent Application Publication No. Hei 11-305036, paragraphs

[0009] to

[0011] of Japanese Patent Application Publication No. 2001-133630, and paragraphs

[0030] to

[0169] of Japanese Patent Application Publication No. 2011-215337. Japanese Patent Application Publication No. 2010-106242, paragraphs

[0021] to

[0075] ; Japanese Patent Application Publication No. 2010-215846, paragraphs

[0011] to

[0025] ; Japanese Patent Application Publication No. 2011-048311, paragraphs

[0017] to

[0069] ; Japanese Patent Application Publication No. 2011-213610, paragraphs

[0013] to

[0133] ; Japanese Patent Application Publication No. 2011-237513, paragraphs

[0074] to

[0246] ; Japanese Patent Application Publication No. 2016-006502, paragraphs

[0021] to

[0075] ; ...215846, paragraphs

[0011] to

[0025] ; Japanese Patent Application Publication No. 2011-048311, paragraphs

[0017] to

[0069] ; Japanese Patent Application Publication No. The dichroic substances described in paragraphs

[0005] to

[0051] , paragraphs

[0005] to

[0041] of International Publication No. 2016 / 060173, paragraphs

[0008] to

[0062] of International Publication No. 2016 / 136561, paragraphs

[0014] to

[0033] of International Publication No. 2017 / 154835, paragraphs

[0014] to

[0033] of International Publication No. 2017 / 154695, and paragraphs

[0013] to

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

[0204] In this invention, two or more dichroic materials can be used simultaneously. For example, from the viewpoint of making the light absorption anisotropic layer close to black, it is preferable to use at least one dichroic material with a maximum absorption wavelength in the wavelength range of 370 to 550 nm and at least one dichroic material with a maximum absorption wavelength in the wavelength range of 500 to 700 nm.

[0205] Furthermore, the composition for forming the optical anisotropic layer may contain an organic solvent. Examples of organic solvents include those described in the optical alignment film composition of the present invention.

[0206] Furthermore, the composition for forming an optical anisotropic layer may contain various orientation agents such as vertical orientation promoters such as polarizer interface-side vertical orientation agents and air interface-side vertical orientation agents, and horizontal orientation promoters such as polarizer interface-side horizontal orientation agents and air interface-side horizontal orientation agents.

[0207] In addition to the above-mentioned components, the composition for forming optical anisotropic layers may also contain adhesion modifiers, plasticizers, polymers, etc.

[0208] There are no particular limitations on the method for forming an optical anisotropic layer using an optical anisotropic layer forming composition having such components. For example, a coating film can be formed by coating the optical anisotropic layer forming composition on the optical alignment film of the present invention described above, and then curing the obtained coating film (ultraviolet irradiation (light irradiation treatment) or heat treatment).

[0209] The coating of the composition for forming an optical anisotropic layer can be carried out by known methods (e.g., wire rod coating, extrusion coating, direct gravure coating, reverse gravure coating, and die coating).

[0210] In this invention, there is no particular limitation on the thickness of the optical anisotropy layer, which is preferably 0.1 to 10 μm, and more preferably 0.5 to 5 μm.

[0211] [Support]

[0212] As described above, the optical laminate of the present invention may have a support as a substrate for forming an optical anisotropic layer.

[0213] Examples of such supports include polarizers, polymer films, and combinations thereof, such as a stack of polarizers and polymer films, or a stack of polymer films, polarizers, and polymer films.

[0214] Furthermore, the support can be a dummy support that can be peeled off after the optical anisotropic layer is formed (hereinafter, sometimes simply referred to as "dummy support"). Specifically, it can be a support that provides the optical anisotropic layer by peeling off a polymer film that functions as a dummy support from the optical laminate. For example, an optical laminate including an optical anisotropic layer and a dummy support is prepared, and after the optical anisotropic layer side of the optical laminate is attached to a support including a polarizer using a bonding agent or adhesive, the dummy support contained in the optical anisotropic layer is peeled off, thereby providing a laminate including a support for a polarizer and an optical anisotropic layer.

[0215] <Polarizer>

[0216] In this invention, when the optical laminate of this invention is used in an image display device, it is preferable to use a polarizer as a support.

[0217] There are no particular limitations on a polarizer as long as it is a component that has the function of converting light into specific linearly polarized light. It can utilize conventionally known absorption polarizers and reflection polarizers.

[0218] As absorption-type polarizers, iodine-based polarizers, dye-based polarizers utilizing dichroic dyes, and polyene-based polarizers are used. Regarding iodine-based and dye-based polarizers, there are coated polarizers and extended polarizers, and they can be used in any way. However, polarizers made by adsorbing iodine or dichroic dyes onto polyvinyl alcohol and then extending it are preferred.

[0219] Furthermore, as a method for obtaining a polarizer by stretching and dyeing in a laminated film having a polyvinyl alcohol layer formed on a substrate, examples include Japanese Patent No. 5048120, Japanese Patent No. 5143918, Japanese Patent No. 4691205, Japanese Patent No. 4751481, and Japanese Patent No. 4751486, and known techniques related to these polarizers can be preferred.

[0220] As a reflective polarizer, polarizers can be made of different layers of birefringent films, wire grid polarizers, polarizers that combine cholesteric liquid crystal with a selective reflection region and a 1 / 4 wavelength plate, etc.

[0221] From an operability perspective, a polarizer comprising a polyvinyl alcohol-based resin (a polymer containing -CH2-CHOH- as a repeating unit; particularly preferably selected from at least one of the group consisting of polyvinyl alcohol and ethylene-vinyl alcohol copolymers) is preferred.

[0222] In the optical laminate of the present invention, which includes a peelable support, the polarizer can be manufactured, for example, as follows.

[0223] Peel the support from the aforementioned optical laminate and stack the layer containing the optical anisotropic layer onto the support containing the polarizer. Alternatively, stack the aforementioned optical laminate onto the support containing the polarizer, and then peel off the peelable support contained in the optical laminate. During lamination, the two layers can be bonded together using an adhesive or the like. There are no particular limitations on the adhesives used. Examples include curable adhesives that do not contain aromatic rings in the molecule, such as those shown in Japanese Patent Application Publication No. 2004-245925; active energy ray-curable adhesives that use a photopolymerization initiator with a molar absorptivity of 400 or more at wavelengths of 360 to 450 nm and an ultraviolet curable compound as essential components, as described in Japanese Patent Application Publication No. 2008-174667; and active energy ray-curable adhesives that contain (a) (meth)acrylic acid compounds having two or more (meth)acryloyl groups in the molecule, (b) (meth)acrylic acid compounds having a hydroxyl group in the molecule and only one polymerizable double bond, and (c) phenol-ethylene oxide modified acrylate or nonylphenol-ethylene oxide modified acrylate, etc.

[0224] The thickness of the polarizer is not particularly limited, but is preferably 1 to 60 μm, more preferably 1 to 30 μm, and even more preferably 2 to 20 μm.

[0225] <Polymer Membrane>

[0226] There are no particular restrictions on polymer films; commonly used polymer films (e.g., polarizer protective films, etc.) can be used.

[0227] Specifically, examples of polymers constituting polymer films include, for example, cellulose-based polymers; acrylic polymers such as polymethyl methacrylate and polymers containing lactone rings; thermoplastic norbornene-based polymers; polycarbonate-based polymers; polyester-based polymers such as polyethylene terephthalate and polyethylene naphthalate; styrene-based polymers such as polystyrene and acrylonitrile-styrene copolymer (AS resin); polyolefin-based polymers such as polyethylene, polypropylene, and ethylene-propylene copolymer; vinyl chloride-based polymers; amide-based polymers such as nylon and aromatic polyamides; imide-based polymers; sulfone-based polymers; polyethersulfone-based polymers; polyetheretherketone-based polymers; polyphenylene sulfide-based polymers; vinylidene chloride-based polymers; vinyl alcohol-based polymers; vinyl butyral-based polymers; aromatic ester-based polymers; polyoxymethylene-based polymers; epoxy-based polymers; or polymers composed of mixtures thereof.

[0228] Among these, cellulose polymers, represented by triacetylcellulose (hereinafter also referred to as "cellulose acylates"), are preferred.

[0229] Furthermore, from the viewpoint of processability and optical performance, acrylic polymers are preferred.

[0230] Examples of acrylic polymers include polymethyl methacrylate or polymers containing lactone rings as described in paragraphs

[0017] to

[0107] of Japanese Patent Application Publication No. 2009-098605.

[0231] The thickness of the polymer film used in polarizer protective films, etc., is not particularly limited, but it is preferably 40 μm or less, considering reasons such as the ability to thin the optical laminate. The lower limit is not particularly limited, but is typically 5 μm or more.

[0232] Furthermore, in this invention, the thickness of the aforementioned support is not particularly limited, but is preferably 1 to 100 μm, more preferably 5 to 50 μm, and even more preferably 5 to 20 μm. Additionally, the thickness of the aforementioned support refers to the total thickness of the polarizer and polymer film when both are present.

[0233] When using a polymer film as a support that can be peeled off from an optical laminate, cellulose-based polymers or polyester-based polymers are preferred. The thickness of the polymer film is not particularly limited, but from the perspective of manufacturing processes, it is preferably 5 μm to 100 μm, more preferably 20 μm to 90 μm. Furthermore, the peeled-off interface can be between the support and the photo-alignment film, between the photo-alignment film and the optical anisotropic layer, or other interfaces.

[0234] [Image Display Device]

[0235] The optical laminate of the present invention can be thinned by peeling off the support, and therefore can be preferably used in the manufacture of image display devices.

[0236] There are no particular limitations on the display elements used in image display devices; examples include liquid crystal cells, organic electroluminescent (hereinafter referred to as "EL") display panels, and plasma display panels.

[0237] Among these, liquid crystal cells and organic EL display panels are preferred, and liquid crystal cells are more preferred. That is, as an image display device, a liquid crystal display device that uses a liquid crystal cell as a display element, an organic EL display device that uses an organic EL display panel as a display element, and a liquid crystal display device are more preferred.

[0238] [Liquid Crystal Display Device]

[0239] One example of an image display device is a liquid crystal display device having the optical laminate and liquid crystal unit described above.

[0240] Furthermore, in this invention, the optical laminate of this invention is preferably used as the polarizer on the front side of the polarizer disposed on both sides of the liquid crystal cell.

[0241] The liquid crystal unit that constitutes a liquid crystal display device will be described in detail below.

[0242] <Liquid Crystal Unit>

[0243] The liquid crystal cells used in the liquid crystal display device are preferably VA (Vertical Alignment) mode, OCB (Optically Compensated Bend) mode, IPS (In-Plane-Switching) mode, or TN (Twisted Nematic) mode, but are not limited to these.

[0244] In TN-mode liquid crystal cells, when no voltage is applied, the rod-shaped liquid crystal molecules (rod-shaped liquid crystal compounds) are actually horizontally aligned and twisted by 60–120°. TN-mode liquid crystal cells are the most widely used in color TFT liquid crystal display devices and are described in numerous documents.

[0245] In VA mode liquid crystal cells, when no voltage is applied, the rod-shaped liquid crystal molecules are substantially vertically oriented. In addition to the VA mode liquid crystal cell, (1) the narrow definition of the VA mode liquid crystal cell in which the rod-shaped liquid crystal molecules are substantially vertically aligned when no voltage is applied and substantially horizontally aligned when a voltage is applied (as described in Japanese Patent Application Publication No. 2-176625), there are also (2) liquid crystal cells in which the VA mode is multi-domained (MVA (Multi-domain Vertical Alignment) mode) to expand the viewing angle (SID97, described in Digest of Tech. Papers 28 (1997) 845), (3) liquid crystal cells in which the rod-shaped liquid crystal molecules are substantially vertically aligned when a voltage is applied and twisted and multi-domain aligned when a voltage is applied (n-ASM mode (Axially Symmetric Aligned Microcell)) (described in the proceedings of the Japan Liquid Crystal Conference 58-59 (1998)), and (4) SURVIVAL (SuperRanged Viewing by Vertical) liquid crystal cells. Alignment: A liquid crystal cell in a vertical nematic mode (disclosed in International Journal of LCD (liquid crystal display) 98). Furthermore, it can be any of PVA (patterned vertical alignment), optical alignment, or PSA (polymer-sustained alignment). Detailed information regarding these modes is described in Japanese Patent Application Publication Nos. 2006-215326 and 2008-538819.

[0246] In IPS-mode liquid crystal cells, rod-shaped liquid crystal molecules are substantially parallel to the substrate, and the liquid crystal molecules respond planarly by applying a parallel electric field to the substrate surface. IPS mode displays black when an electric field is applied, and the absorption axes of the upper and lower polarizers are orthogonal. Methods for reducing light leakage and improving viewing angles when displaying black in the tilt direction using optical compensation sheets are disclosed in Japanese Patent Application Publications Nos. 10-054982, 11-202323, 9-292522, 11-133408, 11-305217, and 10-307291.

[0247] Example

[0248] The present invention will now be described in further detail with reference to embodiments. The materials, amounts, proportions, processing contents, and processing steps shown in the following embodiments can be appropriately modified without departing from the spirit of the invention. Therefore, the scope of the present invention should not be interpreted as limiting the scope of the embodiments shown below.

[0249] Synthesis of monomer mA-7

[0250] 50.0 g of 4-aminocyclohexanol, 48.3 g of triethylamine, and 800 g of N,N-dimethylacetamide were weighed into a 2 L three-necked flask equipped with a stirring blade, thermometer, dropping funnel, and reflux tube, and stirred under ice-cold conditions.

[0251] Next, 47.5 g of methacryloyl chloride was added dropwise over 40 minutes using a dropping funnel. After the addition was completed, the mixture was stirred at 40°C for 2 hours.

[0252] After cooling the reaction solution to room temperature (23°C), the precipitated salt was removed by suction filtration. The resulting organic layer was transferred to a 2L three-necked flask equipped with a stirrer, thermometer, dropping funnel, and reflux tube, and stirred under water cooling.

[0253] Next, 10.6 g of N,N-dimethylaminopyridine and 65.9 g of triethylamine were added, followed by the addition of 127.9 g of 4-methoxycinnamate chloride, pre-dissolved in 125 g of tetrahydrofuran, over a dropping funnel over 30 minutes. After the addition was complete, the mixture was stirred at 50 °C for 6 hours. The reaction solution was cooled to room temperature, washed with water, dried with anhydrous magnesium sulfate, and concentrated to obtain a yellowish-white solid.

[0254] The obtained yellowish-white solid was dissolved by heating in 400g of methyl ethyl ketone and recrystallized to obtain 76g (yield 40%) of the monomer mA-7 as a white solid.

[0255] In addition, the following monomer mA-7 is equivalent to the monomer that forms the above repeating unit A-7.

[0256] [Chemical Formula 14]

[0257]

[0258] Synthesis of monomers such as mA-8

[0259] The raw material 4-aminocyclohexanol was replaced with the corresponding amino alcohol and the corresponding cinnamic acid chloride. Otherwise, monomers mA-8, mA-9, mA-10, mA-12, mA-14, mA-20, mA-21, mA-43 and mA-44 were synthesized by the same method as monomer mA-7.

[0260] In addition, the following monomers mA-8, etc., are respectively equivalent to the monomers that form the above-mentioned repeating unit A-8, etc.

[0261] [Chemical Formula 15]

[0262]

[0263] [Synthesis of monomer mA-2]

[0264] <Synthesis of mA-2 intermediate>

[0265] 12.3 g of 1,4-cyclohexanediamine, 24.7 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, 5.4 g of triethylamine, 6.57 g of N,N-dimethyl-4-aminopyridine, and 140 mL of dichloromethane were added to a 300 mL three-necked flask equipped with a stirring blade, thermometer, dropping funnel, and reflux tube, and stirred at room temperature (23 °C).

[0266] Next, at room temperature, 11.1 g of methacrylic acid was added dropwise over 30 minutes using a dropping funnel. After the addition was complete, the mixture was stirred at 50°C for 5 hours.

[0267] After cooling the reaction solution to room temperature, it was separated and washed with water. The resulting organic layer was dried with anhydrous magnesium sulfate and then concentrated to obtain a yellowish-white solid.

[0268] The obtained yellowish-white solid was purified by silica gel column chromatography (developing solvent hexane / ethyl acetate = 2 / 1) to obtain 14.0 g (70% yield) of 4-methacryloylaminocyclohexylamine, the intermediate of target mA-2, as an amorphous solid.

[0269] <Synthesis of monomer mA-2>

[0270] The starting material 2-hydroxyethyl methacrylate (HEMA) was replaced with the mA-2 intermediate (4-methacryloylaminocyclohexylamine), and cinnamate chloride was replaced with the corresponding cinnamate chloride derivative. Otherwise, the monomer mA-2 shown below was synthesized in the same manner as the monomer mA-7.

[0271] In addition, the following monomer mA-2 is equivalent to the monomer that forms the repeating unit A-2 mentioned above.

[0272] [Chemical Formula 16]

[0273]

[0274] Synthesis of monomers such as mA-16

[0275] By replacing the 1,4-cyclohexanediamine with the corresponding diamine and the corresponding cinnamic acid chloride, monomers mA-16, mA-18 and mA-19 were synthesized using the same method as monomer mA-2.

[0276] Furthermore, the following monomers, such as mA-16, are respectively equivalent to the monomers that form the aforementioned repeating unit A-16, etc.

[0277] [Chemical Formula 17]

[0278]

[0279] Synthesis of monomer mA-38

[0280] 43.9 g of 4-hydroxypiperidine, 48.3 g of triethylamine, and 800 g of N,N-dimethylacetamide were weighed into a 2 L three-necked flask equipped with a stirring blade, thermometer, dropping funnel, and reflux tube, and stirred under ice-cold conditions.

[0281] Next, 134.4 g of 4-octyloxycinnamate chloride, which was pre-dissolved in 150 g of tetrahydrofuran, was added dropwise over 30 minutes using a dropping funnel. After the addition was completed, the mixture was stirred at 40 °C for 1 hour.

[0282] After cooling the reaction solution to room temperature (23°C), the precipitated salt was removed by suction filtration. The resulting organic layer was transferred to a 2L three-necked flask equipped with a stirrer, thermometer, dropping funnel, and reflux tube, and stirred under water cooling.

[0283] Next, 10.6 g of N,N-dimethylaminopyridine and 65.9 g of triethylamine were added, and 47.5 g of methacryloyl chloride was added dropwise over 30 minutes using a dropping funnel. After the addition was complete, the mixture was stirred at 40°C for 1 hour. After cooling the reaction solution to room temperature, it was separated and washed with water. The resulting organic layer was dried with anhydrous magnesium sulfate and concentrated to obtain a yellowish-white solid.

[0284] The obtained yellowish-white solid was dissolved by heating in 400g of methanol and recrystallized to obtain 92g (yield 50%) of the monomer mA-8 as a white solid.

[0285] In addition, the following monomer mA-38 is equivalent to the monomer that forms the above repeating unit A-38.

[0286] [Chemical Formula 18]

[0287]

[0288] Synthesis of monomer mH-1

[0289] The monomer mH-1 shown below was synthesized using 2-hydroxyethyl methacrylate (HEMA) (TOKYO CHEMICAL INDUSTRY CO.,LTD.) and chlorinated cinnamate (TOKYO CHEMICAL INDUSTRY CO.,LTD.) according to the method described in Langmuir, 32(36), 9245-9253, (2016).

[0290] In addition, the following monomer mH-1 is equivalent to the monomer that forms the repeating unit H-1 shown below.

[0291] [Chemical Formula 19]

[0292]

[0293] Synthesis of monomer mH-2

[0294] The raw material 2-hydroxyethyl methacrylate (HEMA) was changed to 2-hydroxyethyl acrylamide (TOKYOCHEMICAL INDUSTRY CO.,LTD.) and the corresponding cinnamic acid chloride derivative was changed. Otherwise, the monomer mH-2 shown below was synthesized by the same method as monomer mH-1.

[0295] In addition, the following monomer mH-2 is equivalent to the monomer that forms the repeating unit H-2 shown below.

[0296] [Chemical Formula 20]

[0297]

[0298] Synthesis of monomer mB-18

[0299] The raw material, cinnamate chloride, was replaced with 3-chloropropionyl chloride (TOKYO CHEMICAL INDUSTRY CO.,LTD.). Otherwise, monomer mB-18, as shown below, was synthesized using the same method as monomer mH-1. Furthermore, monomer mB-18 is a monomer equivalent to the precursor that forms the repeating unit B-18 described above (i.e., the unit before being changed to an acryloyl group through deprotection).

[0300] [Chemical Formula 21]

[0301]

[0302] [Other monomers]

[0303] The monomer mB-1 forming the repeating unit B-1 uses commercially available glycidyl methacrylate (TOKYO CHEMICAL INDUSTRY CO.,LTD.), the monomer mB-2 forming the repeating unit B-2 uses CYCLOMER M-100 (manufactured by Daicel Chemical Industries Ltd.), and the monomer mB-3 forming the repeating unit B-3 uses OXE-30 (manufactured by Osaka Organic Chemical Industry Co.,Ltd.).

[0304] [Chemical Formula 22]

[0305]

[0306] [Example 1]

[0307] Five parts by mass of 2-butanone were added to a flask equipped with a cooling tube, thermometer, and stirrer as a solvent. The mixture was refluxed by heating in a water bath while nitrogen flowed at a rate of 5 mL / min. A solution containing five parts by mass of monomer mA-2, five parts by mass of monomer mB-15, one part by mass of 2,2'-azobis(isobutyronitrile) as a polymerization initiator, and five parts by mass of 2-butanone as a solvent was added dropwise over 3 hours. The mixture was further stirred under reflux for another 3 hours. After the reaction was complete, the mixture was allowed to cool naturally to room temperature and diluted with 30 parts by mass of 2-butanone to obtain a polymer solution of approximately 20% by mass. The obtained polymer solution was precipitated by adding a large amount of excess methanol. The recovered precipitate was filtered, washed with a large amount of methanol, and then dried under air at 50°C for 12 hours to obtain polymer P-1 with photooriented groups.

[0308] [Examples 2 to 34 and Comparative Examples 1 to 4]

[0309] As monomers forming the repeating units shown in Table 3 below, each of the synthesized monomers was used, and the amount of polymerization initiator added was varied in such a way as to become the weight-average molecular weight shown in Table 3 below. Otherwise, the polymer was synthesized in the same manner as polymer P-1 synthesized in Example 1.

[0310] [Example 35]

[0311] Five parts by mass of 2-butanone were added to a flask equipped with a cooling tube, thermometer, and stirrer as a solvent. The mixture was refluxed by heating in a water bath while nitrogen flowed at a rate of 5 mL / min. A solution containing 10 parts by mass of monomer mA-9, 75 parts by mass of monomer mB-2, 15 parts by mass of monomer mB-18, 0.8 parts by mass of 2,2'-azobis(isobutyronitrile) as a polymerization initiator, and 5 parts by mass of 2-butanone as a solvent was added dropwise over 3 hours. The mixture was then stirred for another 12 hours under reflux. Next, the mixture was cooled to 60°C, and 0.01 parts by mass of 4-methoxyphenol and 15 parts by mass of diazabicycloundecene were added. The reaction was further carried out at 60°C for 6 hours. After the reaction was complete, the mixture was allowed to cool naturally to room temperature, and then diluted with 30 parts by mass of 2-butanone to obtain a polymer solution of approximately 20% by mass. The obtained polymer solution was added to a large amount of excess methanol to precipitate the polymer. The recovered precipitate was filtered and washed with a large amount of methanol, and then dried at 50°C for 12 hours to obtain polymer P-35.

[0312] [Example 36]

[0313] Five parts by mass of 2-butanone were added to a flask equipped with a cooling tube, thermometer, and stirrer as a solvent. Nitrogen was introduced into the flask at a flow rate of 5 mL / min while the mixture was refluxed via a water bath. A solution containing 10 parts by mass of monomer mA-9, 75 parts by mass of monomer mB-2, 15 parts by mass of 2-hydroxyethyl methacrylate (HEMA) (TOKYOCHEMICAL INDUSTRY CO.,LTD.), 0.8 parts by mass of 2,2'-azobis(isobutyronitrile) as a polymerization initiator, and 5 parts by mass of 2-butanone as a solvent was added dropwise over 3 hours. The mixture was then stirred for another 3 hours under reflux. Next, the mixture was cooled to room temperature, and 20 parts by mass of KARENZ MOI (manufactured by SHOWA DENKO KK) and 0.1 parts by mass of NEOSTANNU-830 (manufactured by NITTOH CHEMICAL CO.,LTD.) were added. The reaction was then carried out at room temperature for 4 hours. After the reaction was complete, the mixture was allowed to cool naturally to room temperature and diluted with 30 parts by mass of 2-butanone to obtain a polymer solution of approximately 20% by mass. The obtained polymer solution was then added to a large amount of excess methanol to precipitate the polymer. The recovered precipitate was filtered, washed with a large amount of methanol, and then dried under blast air at 50°C for 12 hours to obtain polymer P-36.

[0314] [Examples 37 to 47]

[0315] Polymers P-37 to P-47 were synthesized using the same method as polymer P-35 described in Example 35, except that the raw material monomer mB-18 was changed to 2-(2-bromoisobutoxy)ethyl methacrylate and the loading amount was changed to correspond to the content of repeating unit B2 shown in Table 3 below.

[0316] The weight-average molecular weight of each synthesized polymer was determined using the method described above. The results are shown in Table 3 below.

[0317] [Table 3]

[0318]

[0319] ※ Set the content of the repeating units recorded in the column "Repeating Unit A, etc." to 'a'.

[0320] Set the content of the repeating units recorded in the "Repeating Unit B1" column to b1.

[0321] Set the content of the repeating units recorded in the "Repeat Unit B2" column to b2.

[0322] Next, the polymers synthesized in Examples 1 to 4, 6, 8, 10, 13, 14, 16, 19 to 42 and 47 and Comparative Examples 1 to 4 were evaluated as follows.

[0323] [Preparation of compositions for photo-alignment films]

[0324] A composition for photo-aligning film was prepared by adding 8.8 parts by weight of copolymer P-1 synthesized in Example 1 to butyl acetate / methyl ethyl ketone (80 parts by weight / 20 parts by weight) and 0.07 parts by weight of a thermally generated acid agent represented by the following structural formula.

[0325] Using the same method, compositions for photo-alignment films were also prepared by adding 8.8 parts by weight of butyl acetate / methyl ethyl ketone (80 parts by weight / 20 parts by weight) to each copolymer synthesized in other examples and comparative examples.

[0326] [Chemical Formula 23]

[0327]

[0328] [Fabrication of Optical Laminates]

[0329] As a cellulose acylated membrane, the same membrane as Comparative Example 1 of Japanese Patent Application Publication No. 2014-164169 was used.

[0330] On one side of the film, pre-prepared photo-alignment film compositions were coated by rod coating. After coating, the solvent was removed by drying on a hot plate at 80°C for 5 minutes to form a photoisomerization composition layer with a thickness of 0.2 μm. The obtained photoisomerization composition layer was then subjected to polarized ultraviolet irradiation (10 mJ / cm²). 2 The photo-alignment film was formed by using an ultra-high pressure mercury lamp.

[0331] Next, a nematic liquid crystal compound (ZLI-4792, manufactured by Merck) was applied to the photoalignment film by rod coating to form a composite layer. The formed composite layer was temporarily heated to 90°C on a hot plate and then cooled to 60°C to stabilize the alignment.

[0332] Then, maintaining the temperature at 60°C, the mixture was subjected to ultraviolet irradiation (500 mJ / cm²) under a nitrogen atmosphere (oxygen concentration 100 ppm). 2 An optical laminate was fabricated by using an ultra-high pressure mercury lamp to fix the orientation and form an optical anisotropic layer with a thickness of 2.0 μm.

[0333] [Example 48]

[0334] Instead of the nematic liquid crystal compound coated on the photo-alignment film, an optical anisotropic layer coating liquid (liquid crystal 101) as shown below was used. Otherwise, an optical laminate was fabricated using the same method as in Example 24. This optical laminate was used as the optical laminate of Example 48.

[0335]

[0336] [Chemical Formula 24]

[0337]

[0338] [Example 49]

[0339] Instead of the nematic liquid crystal compound coated on the photo-alignment film, an optical anisotropic layer coating liquid (liquid crystal 102) as shown below was used, and the alignment of the liquid crystal compound was fixed by the fabrication method shown below. Otherwise, an optical laminate was fabricated in the same manner as in Example 24. This optical laminate was used as the optical laminate of Example 49.

[0340]

[0341] In addition, the group adjacent to the acryloxy group in the following liquid crystal compounds L-3 and L-4 represents a propenyl group (a group in which the methyl group is replaced by a vinyl group), and the following liquid crystal compounds L-3 and L-4 represent a mixture of positional isomers of the methyl group in different positions.

[0342] [Chemical Formula 25]

[0343]

[0344]

[0345] [Production Method]

[0346] Liquid crystal 102 was coated on the photo-aligned surface using a bar coater. The coating formed on the alignment film was heated to 120°C under warm air, then cooled to 60°C, and subsequently irradiated with a high-pressure mercury lamp at a wavelength of 365 nm in a nitrogen atmosphere at 10 mJ / cm². 2 The coating was then exposed to ultraviolet light, followed by heating to 120°C while being irradiated with 500 mJ / cm² of ultraviolet light. 2 The optical laminate of Example 49 was fabricated by using ultraviolet light to fix the orientation of the liquid crystal compound.

[0347] [Example 50]

[0348] Instead of the nematic liquid crystal compound coated on the photo-alignment film, a coating liquid (liquid crystal 103) for the optical anisotropic layer as shown below was used. Otherwise, the optical laminate was fabricated using the same method as in Example 24. This optical laminate was used as the optical laminate of Example 50.

[0349]

[0350] [Chemical Formula 26]

[0351]

[0352] [Example 51]

[0353] Instead of the nematic liquid crystal compound coated on the photo-alignment film, a coating liquid (liquid crystal 104) for the optical anisotropic layer as shown below was used. Otherwise, the optical laminate was fabricated using the same method as in Example 39. This optical laminate was used as the optical laminate of Example 51.

[0354]

[0355] [Chemical Formula 27]

[0356]

[0357] [Example 52]

[0358] In the preparation of the composition for the photo-alignment film, 0.26 parts by weight of a thermally generated acid agent represented by the following structural formula were added. Otherwise, an optical laminate was prepared using the same method as in Example 50. This optical laminate was used as the optical laminate of Example 52.

[0359] [Chemical Formula 28]

[0360]

[0361] [Example 53]

[0362] The amount of thermally generated acid agent added was changed to 0.53 parts by weight. Otherwise, an optical laminate was prepared using the same method as in Example 52. This optical laminate was used as the optical laminate of Example 53.

[0363] [Example 54]

[0364] The amount of thermally generated acid agent added was changed to 0.79 parts by weight. Otherwise, the optical laminate was prepared using the same method as in Example 52. This optical laminate was used as the optical laminate of Example 54.

[0365] [Example 55]

[0366] In the preparation of the composition for the photo-alignment film, copolymer P-37 of the present invention was used, and the optical laminate was otherwise prepared using the same method as in Example 50. This optical laminate was used as the optical laminate of Example 55.

[0367] [Example 56]

[0368] In the preparation of the composition for photo-alignment film, the copolymer P-42 of the present invention was used, and a photoinitiator represented by the following structural formula was used instead of a thermally generated acid agent. Otherwise, the composition for photo-alignment film was prepared in the same manner as in Example 52.

[0369] [Chemical Formula 29]

[0370]

[0371] [Fabrication of Optical Laminates]

[0372] As a cellulose acylated membrane, the same membrane as Comparative Example 1 of Japanese Patent Application Publication No. 2014-164169 was used.

[0373] A pre-prepared composition for photo-alignment film was coated onto one side of the film using a bar coater. After coating, the solvent was removed by drying on a hot plate at 123°C for 62 seconds, and then irradiated (300 mJ / cm²). 2 A photoisomerization composition layer with a thickness of 0.3 μm was formed using an ultra-high pressure mercury lamp and a 365 nm bandpass filter. The resulting photoisomerization composition layer was then irradiated with polarized ultraviolet light (7.9 mJ / cm²). 2 The photo-alignment film was formed by using an ultra-high pressure mercury lamp.

[0374] Next, the aforementioned coating liquid for the optical anisotropic layer (liquid crystal 103) was used on the optical alignment film, and an optical laminate was fabricated using the same method as in Example 50. This optical laminate was used as the optical laminate of Example 56.

[0375] [Example 57]

[0376] In the preparation of the composition for photo-alignment film, copolymer P-47 of the present invention was used, and the optical laminate was otherwise prepared using the same method as in Example 56. This optical laminate was used as the optical laminate of Example 57.

[0377] [Solubility]

[0378] For each synthesized polymer, its solubility relative to the butyl acetate / methyl ethyl ketone (80 / 20) mixed solvent used as a coating solvent was observed visually at room temperature and evaluated using the following criteria. The results are shown in Table 4 below.

[0379] A: Dissolves 10wt% or more

[0380] B: Dissolves 5wt% or more but less than 10wt%

[0381] C: Dissolves 1 wt% or more but less than 5 wt%

[0382] D: Only dissolves less than 1 wt%.

[0383] [Soluble resistance]

[0384] The dichroism ratio of the photoalignment film itself was evaluated after coating with methyl ethyl ketone, and the evaluation was performed according to the following criteria. The results are shown in Table 4 below. In addition, the solvent resistance of Comparative Example 1, which was rated as D for solubility, was not evaluated, and therefore it is marked as "-" in Table 4 below.

[0385] AA: The difference in dichroism ratio before and after coating is greater than 0% and less than 30%.

[0386] A: The difference in dichroism ratio before and after coating is greater than 30% but less than 40%.

[0387] B: The difference in dichroism ratio before and after coating is greater than 40% and less than 50%.

[0388] C: The difference in dichroism ratio before and after coating is greater than 50% and less than 60%.

[0389] D: The difference in dichroism ratio before and after coating is over 60%.

[0390] [Liquid Crystal Orientation (Fr)]

[0391] The fabricated optical laminate was observed using a polarizing microscope at a position 2 degrees below the extinction point. The results were evaluated according to the following criteria. The results are shown in Table 4 below. Furthermore, Comparative Example 1, which received a solubility rating of D, was not evaluated for solvent resistance; therefore, it is marked "-" in Table 4 below.

[0392] AAA: The liquid crystal polarizers are uniformly aligned and oriented, and the surface appearance and display performance are excellent.

[0393] AA: The liquid crystal polarizers are uniformly aligned and oriented, resulting in excellent display performance.

[0394] A: No disorder in the liquid crystal pointing vector, and stable surface structure.

[0395] B: Slight disturbance in the liquid crystal pointing vector, but stable surface structure.

[0396] C: Localized disturbances exist in the liquid crystal pointing vector, but the surface is stable.

[0397] D: The liquid crystal pointing vector is highly disordered and the surface is unstable, resulting in very poor display performance.

[0398] In addition, in this application specification, a stable planar shape refers to a state in which an optical laminate is placed between two polarizers arranged in an orthogonal Nicol configuration, and there are no defects such as unevenness or poor orientation when observed.

[0399] Furthermore, in this application specification, the liquid crystal pointer vector refers to the vector of the orientation direction (orientation principal axis) of the long axis of the liquid crystal molecules.

[0400] [Liquid Crystal Orientation (over time)]

[0401] For the optical alignment film produced, after 1.5 hours at 40°C and 60% relative humidity before coating with the nematic liquid crystal compound, an optical laminate was produced using the same method as the optical laminate described above. The alignment properties were observed and evaluated according to the following criteria. The results are shown in Table 4 below. Furthermore, the solvent resistance of Comparative Example 1 (which received a solubility rating of D) and Comparative Example 2 (which received a liquid crystal alignment (Fr) rating of D) was not evaluated, and therefore are marked as "-" in Table 4 below.

[0402] AA: The liquid crystal polarizers are uniformly aligned and oriented, resulting in excellent display performance.

[0403] A: No disorder in the liquid crystal pointing vector, and stable surface structure.

[0404] B: Slight disturbance in the liquid crystal pointing vector, but stable surface structure.

[0405] C: Localized disturbances exist in the liquid crystal pointing vector, and the surface appearance is poor.

[0406] D: The liquid crystal pointing vector is highly disordered and the surface is unstable, resulting in very poor display performance.

[0407] [Table 4]

[0408]

[0409] ※ Set the content of the repeating units recorded in the column "Repeating Unit A, etc." to 'a'.

[0410] Set the content of the repeating units recorded in the "Repeating Unit B1" column to b1.

[0411] Set the content of the repeating units recorded in the "Repeat Unit B2" column to b2.

[0412] The results shown in Table 4 indicate that when the repeating unit B does not contain a crosslinking group represented by the above formula (B), the solubility is poor, or even when the solubility is not a problem, the solvent resistance and liquid crystal alignment of the photo-alignment film are poor (Comparative Example 1 and Comparative Example 2).

[0413] Furthermore, it was found that when the repeating unit containing the cinnamic acid ester group does not contain a divalent linker containing a nitrogen atom and a cycloalkane ring, even if the repeating unit B contains a crosslinking group represented by the above formula (B), the liquid crystal orientation of the photo-alignment film is poor (over time) (Comparative Examples 3 and 4).

[0414] In contrast, it has been found that when a photo-oriented copolymer containing repeating unit A, which includes a photo-oriented group represented by the above formula (A), and repeating unit B, which includes a crosslinking group represented by the above formula (B), is used, the solvent resistance of the photo-oriented film becomes better, and the liquid crystal orientation is excellent regardless of the timing of forming the optical anisotropic layer (Examples 1 to 4, Examples 6, 8, 10, 13, 14, 16, 19 to 41, and 48 to 57).

[0415] In particular, a comparison of the embodiments reveals that if R in the above formula (A) 4 If the alkoxy group has 6 to 16 carbon atoms, the liquid crystal orientation will be well modified.

[0416] Furthermore, a comparison of the embodiments reveals that if L in the above formula (A) 1 If the divalent linker is represented by any one of the above formulas (2) to (4), then the balance between the solubility of the solvent used to form the photo-aligned film and the solvent resistance of the resulting photo-aligned film becomes better.

[0417] [Example 58]

[0418] [Preparation of coating solution]

[0419] Instead of the nematic liquid crystal compound coated on the alignment film, an optically anisotropic layer coating liquid (liquid crystal 105) as shown below was used, and the alignment of the liquid crystal compound was fixed by the fabrication method shown below. Otherwise, an optical laminate was fabricated in the same manner as in Example 24. This optical laminate was used as the optical laminate of Example 58.

[0420]

[0421]

[0422] Liquid crystal compound L-8

[0423] [Chemical Formula 30]

[0424]

[0425] Liquid crystal compound L-9

[0426] [Chemical Formula 31]

[0427]

[0428] Liquid crystal compound L-10

[0429] [Chemical Formula 32]

[0430]

[0431] [Production Method]

[0432] An optical anisotropic layer coating liquid (liquid crystal 105) was applied to the optical alignment surface using a rod coater. The coating formed on the alignment film was heated to 120°C under warm air, then cooled to 60°C, and subsequently irradiated with a high-pressure mercury lamp at a wavelength of 365 nm at 100 mJ / cm² in a nitrogen atmosphere. 2 The coating was then exposed to ultraviolet light, followed by heating to 120°C while being irradiated with 500 mJ / cm² of ultraviolet light. 2 The optical laminate of Example 58 was fabricated by using ultraviolet light to fix the orientation of the liquid crystal compound.

[0433] [Example 59]

[0434] Instead of the nematic liquid crystal compound coated on the alignment film, an optically anisotropic layer coating liquid (liquid crystal 106) as shown below was used, and the alignment of the liquid crystal compound was fixed by the fabrication method shown below. Otherwise, an optical laminate was fabricated in the same manner as in Example 24. This optical laminate was used as the optical laminate of Example 59.

[0435]

[0436] [Chemical Formula 33]

[0437]

[0438] [Production Method]

[0439] An optical anisotropic layer coating liquid (liquid crystal 106) was applied to the photo-alignment surface using a rod coater. After heating and aging at 100°C for 20 seconds and cooling to 90°C, the film was irradiated with 300 mJ / cm² in air using an air-cooled metal halide lamp (manufactured by EYEGRAPHICS Co., Ltd.). 2 The ultraviolet light is used to form the optical laminate of Example 59 by fixing the nematic orientation state.

[0440] [Example 60]

[0441] Instead of the nematic liquid crystal compound coated on the alignment film, an optically anisotropic layer coating liquid (liquid crystal 107) as shown below was used, and the alignment of the liquid crystal compound was fixed by the fabrication method shown below. Otherwise, an optical laminate was fabricated in the same manner as in Example 24. This optical laminate was used as the optical laminate of Example 60.

[0442]

[0443] [Chemical Formula 34]

[0444]

[0445] [Production Method]

[0446] Next, an optical anisotropic layer coating liquid (liquid crystal 107) was applied to the optical alignment surface using a rod coater. The coating formed on the alignment film was heated to 120°C under warm air, then cooled to 60°C, and subsequently irradiated with a high-pressure mercury lamp at a wavelength of 365 nm at a concentration of 10 mJ / cm² in a nitrogen atmosphere. 2 The coating was then exposed to ultraviolet light, followed by heating to 120°C while being irradiated with 500 mJ / cm² of ultraviolet light. 2 The optical laminate of Example 60 was fabricated by using ultraviolet light to fix the orientation of the liquid crystal compound.

[0447] [Examples 61 and 62]

[0448] In Example 24, the cellulose acylated membrane 1 or the cellulose acylated membrane 2 described in Comparative Example 1 of Japanese Patent Application Publication No. 2014-164169 was used instead of the cellulose acylated membrane described in Comparative Example 1. Otherwise, samples obtained in the same manner as in Example 24 were used as Examples 61 and 62, respectively.

[0449] [Preparation of cellulose acylated membrane 1]

[0450] (Preparation of concentrated cellulose acylate solution from the core layer)

[0451] The following composition was added to a mixing tank and stirred to dissolve the components, thereby preparing a cellulose acetate solution for use as a core layer cellulose acylation concentrate.

[0452]

[0453] Compound G

[0454] [Chemical Formula 35]

[0455]

[0456] (Preparation of concentrated outer cellulose acylate solution)

[0457] A cellulose acetate solution for use as an outer layer cellulose acylate was prepared by adding 10 parts by mass of the following matting agent solution to 90 parts by mass of the above core layer cellulose acylate concentrate.

[0458]

[0459] (Casting of cellulose acylated membrane 1)

[0460] After filtering the core layer cellulose acylate concentrate and the outer layer cellulose acylate concentrate using filter paper with an average pore size of 34 μm and a sintered metal filter with an average pore size of 10 μm, the core layer cellulose acylate concentrate and the outer layer cellulose acylate concentrate disposed on both sides thereon are simultaneously cast from the casting port onto a roller (belt casting machine) at 20°C in three layers. The film is peeled off with a solvent content of approximately 20% by mass, and the two ends of the film in the width direction are fixed using a tenter frame clamp. It is then dried while being stretched laterally at an elongation ratio of 1.1. Then, it is further dried by conveying it between the rollers of a heat treatment apparatus to produce an optical film with a thickness of 40 μm, which is used as the optical film of Example 1. The core layer of the optical film of Example 1 has a thickness of 36 μm, and the outer layers disposed on both sides of the core layer have thicknesses of 2 μm each. The resulting cellulose acylate film 1 has an in-plane retardation of 0 nm.

[0461] [Preparation of cellulose acylated membrane 2]

[0462] The same membrane as that used in Example 6 of Japanese Patent Application Publication No. 2012-215689 was used as the cellulose acylated membrane.

[0463] In Examples 58 to 62, the liquid crystal orientation (Fr, time) as an evaluation item in Table 4 was AAA and AA, respectively, which were good results, just like in Example 24.

Claims

1. A photooriented copolymer having repeating unit A comprising a photooriented group represented by formula (A) and repeating unit B comprising a crosslinking group represented by formula (B). In equation (A), R 1 R represents a hydrogen atom or a methyl group. 2 R 3 R 4 R 5 and R 6 Each can independently represent a hydrogen atom or a substituent, R 2 R 3 R 4 R 5 and R 6 Two adjacent groups can also bond together to form a ring. In equation (B), R 7 L represents a hydrogen atom or a methyl group. 2 Indicates a bivalent linker. In formula (B), X is at least one crosslinking group selected from the group consisting of formulas (X1) to (X3) below. In equations (X1) to (X3), * represents L in equation (B). 2 The bonding position, R 8 It represents any one of hydrogen atom, methyl, and ethyl. L in formula (A) 1 Let be a divalent linker represented by any one of the following equations (1) to (10). In formulas (1) to (10), *1 represents the bonding position with the carbon atom constituting the main chain in formula (A), and *2 represents the bonding position with the carbon atom constituting the carbonyl group in formula (A).

2. The photo-oriented copolymer according to claim 1, wherein, The repeating unit B includes repeating unit B1 in which X in formula (B) is a crosslinking group represented by any one of formulas (X1) to (X3), and repeating unit B2 in which X in formula (B) is a crosslinking group represented by the following formula (X4). In formula (X4), S represents any one of vinyl, allyl, styrene, acryloyl, and methacryl. The content a of repeating unit A, the content b1 of repeating unit B1, and the content b2 of repeating unit B2, in mass ratio, satisfy the following equation (17). 0.10≤b2 / (a+b1+b2)≤0.5…(17).

3. The photo-oriented copolymer according to claim 1 or 2, wherein, L in equation (B) 2 Each is independently a divalent linker composed of at least two groups selected from the group consisting of straight-chain, branched, or cyclic alkylene groups having 1 to 18 carbon atoms that may have substituents, aryl, ether, or carbonyl groups having 6 to 12 carbon atoms that may have substituents, and imino groups that may have substituents.

4. The photo-oriented copolymer according to claim 1, wherein, L in formula (A) 1 Let be a divalent linker represented by any one of the equations (2), (3), (7) and (8).

5. The photo-oriented copolymer according to claim 1 or 2, wherein, R in equation (A) 2 R 3 R 4 R 5 and R 6 In, at least R 4 Indicates a substituent.

6. The photo-oriented copolymer according to claim 5, wherein, R in equation (A) 2 R 3 R 5 and R 6 Both represent hydrogen atoms.

7. The photo-oriented copolymer according to claim 5, wherein, R in equation (A) 4 It is an electron-donating substituent.

8. The photo-oriented copolymer according to claim 7, wherein, R in equation (A) 4 It is an alkoxy group with 6 to 16 carbon atoms.

9. The photo-oriented copolymer according to claim 1 or 2, wherein, R in equation (A) 2 R 3 R 4 R 5 and R 6 The substituents represented are, independently, halogen atoms, straight-chain, branched, or cyclic alkyl groups having 1 to 20 carbon atoms, straight-chain haloalkyl groups having 1 to 20 carbon atoms, alkoxy groups having 1 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, aryloxy groups having 6 to 20 carbon atoms, cyano groups, amino groups, or groups represented by the following formula (11). In formula (11), * represents the bonding position with the benzene ring in formula (A), R 9 It represents a monovalent organic group.

10. The photo-oriented copolymer according to claim 1 or 2, wherein, The content a of repeating unit A and the content b of repeating unit B, expressed as a mass ratio, satisfy the following equation (12). 0.03≤a / (a+b)≤0.5 (12).

11. The photo-oriented copolymer according to claim 10, wherein, The content a of repeating unit A and the content b of repeating unit B, expressed as a mass ratio, satisfy the following equation (13). 0.03≤a / (a+b)≤0.3 (13).

12. The photo-oriented copolymer according to claim 10, wherein, The content a of repeating unit A and the content b of repeating unit B, expressed as a mass ratio, satisfy the following equation (14). 0.03≤a / (a+b)≤0.2 (14).

13. The photo-oriented copolymer according to claim 1 or 2, wherein, The weight-average molecular weight of the photooriented copolymer is 10,000 to 500,000.

14. The photo-oriented copolymer according to claim 13, wherein, The weight-average molecular weight of the photooriented copolymer is 30,000 to 300,000.

15. A photo-alignment film formed using a photo-alignment film composition containing any one of claims 1 to 14.

16. An optical laminate having the optical alignment film of claim 15 and an optical anisotropy layer formed using a liquid crystal composition containing a liquid crystal compound.

Images