Method for manufacturing a liquid crystal alignment film, a radical generating film, and a horizontal electric field liquid crystal cell

Abstract

The present invention provides a liquid crystal alignment agent for a horizontal electric field liquid crystal display element that simultaneously achieves non-contact alignment, low drive voltage, and accelerated response speed when the voltage is off, by applying a polymer stabilization technology capable of producing a weak anchoring film. The liquid crystal alignment agent comprises a polymer having a structural unit represented by the following formula (1) in its main chain: #imgabs0# (in formula (1), A represents an organic group that initiates free radical polymerization).

Description

Technical Field

[0001] The present invention relates to a liquid crystal aligning agent and a radical-generating film that can be suitably used in a PSA-type liquid crystal display element or a weak anchor liquid crystal display element, etc., which are produced by irradiating liquid crystal molecules with ultraviolet light while applying a voltage.

[0002] Moreover, the present invention relates to a method for producing a horizontal electric field liquid crystal cell using the liquid crystal alignment agent or the radical generating film. Background Art

[0003] In recent years, liquid crystal display elements have been widely used in mobile phones, computers, and television displays. Liquid crystal display elements have the characteristics of being thin, lightweight, and having low power consumption. In the future, they are expected to be used in more fields such as VR (Virtual Reality) and ultra-high-definition displays. Regarding the display method of liquid crystal displays, various display modes such as TN (Twisted Nematic), IPS (In-Plane Switching), and VA (Vertical Alignment) have been proposed. However, all modes use a film (liquid crystal alignment film) to induce the liquid crystal into the desired orientation state.

[0004] In particular, in products with touch panels such as tablet PCs, smartphones, and smart TVs, the IPS mode is preferred, in which the display is less likely to be disturbed even when touched. In recent years, technologies such as liquid crystal display elements using FFS (Fringe Field Switching) and non-contact technology using optical orientation have been gradually adopted to improve contrast and viewing angle characteristics.

[0005] In recent years, with the goal of achieving even higher resolutions and higher contrast, such as 4K and 8K, there has been a trend toward higher backlight brightness. This has led to increased transmittance and lower drive voltages for LCDs. In particular, with the FFS mode being used not only in TVs but also in tablets and smartphones, increasing transmittance and reducing drive voltages have become crucial technical challenges.

[0006] Regarding improving the transmittance of liquid crystal display elements, the use of negative liquid crystals is recommended for FFS mode, and practical application is progressing. On the other hand, while negative liquid crystals significantly improve transmittance, they also come with issues such as decreased response time and increased drive voltage, resulting in poor power consumption reduction. Furthermore, negative liquid crystals themselves are prone to dissolving contaminants, which can lead to undesirable effects such as unevenness and ghosting.

[0007] Recently, weak-anchor IPS technology, which uses a film with very low anchoring energy as a liquid crystal alignment film, has attracted attention as a technology for improving the transmittance of liquid crystal display elements and reducing driving voltage. Even when using an IPS substrate with a relatively wide comb-tooth electrode width, weak-anchor IPS technology can significantly improve transmittance and reduce driving voltage. Therefore, if it can be put into practical use, it will have significant advantages in terms of substrate cost and can suppress the occurrence of flicker, a problem unique to the FFS mode (see Patent Document 1).

[0008] In recent years, the use of dense polymer brushes to create a zero-plane state has led to the proposal of a zero-plane anchored IPS mode (also known as a weakly anchored IPS mode) (see Patent Document 2). This technology has significantly improved contrast and reduced driving voltage.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: Japanese Patent No. 4053530

[0012] Patent Document 2: Japanese Patent Application Laid-Open No. 2013-231757 Summary of the Invention

[0013] Technical problem to be solved by the invention

[0014] However, this technology has problems in principle. First, in order to stably produce polymer brushes on the substrate, it needs to be done under very delicate conditions, which is unrealistic from the perspective of mass production. Second, although the orientation film plays an important role in suppressing ghosting, it is difficult to control the required electrical properties when using polymer brushes. Third, in terms of the driving principle, the response speed is very slow when the voltage is off. It can be expected that by making the orientation control force zero, the resistance applied to the liquid crystal during driving will be eliminated, thereby significantly reducing the threshold voltage. It can also be expected that the brightness will be improved due to the reduction of poorly oriented areas during driving. However, as for the recovery of the liquid crystal, it can be considered that since the power of the liquid crystal recovery depends on the elastic force of the liquid crystal, the speed will be significantly reduced compared to the case with an orientation film.

[0015] Considering that if such technical problems can be solved, it will have great cost advantages for panel manufacturers, and will also have advantages in suppressing battery consumption, improving image quality, etc.

[0016] The present invention is made to solve the above-mentioned technical problems. Its purpose is to apply polymer stabilization technology that can produce weak anchor films to provide a horizontal electric field liquid crystal display element that can simultaneously achieve non-contact orientation, low driving voltage and accelerated response speed when the voltage is off at room temperature in a simple and inexpensive way.

[0017] In particular, an object of the present invention is to provide a horizontal electric field liquid crystal display element having excellent black display quality, high transmittance, and suppressed response time delay, which is a technical problem of weak anchor display elements.

[0018] Furthermore, in order to obtain such an excellent horizontal electric field liquid crystal display element, an object of the present invention is to provide a liquid crystal aligning agent used for the horizontal electric field liquid crystal display element.

[0019] Means for solving technical problems

[0020] The present inventors have conducted intensive studies to solve the above-mentioned technical problems, and as a result, have found that the above-mentioned technical problems can be solved, and have completed the present invention having the following gist.

[0021] That is, the present invention includes the following technical solutions.

[0022] [1] A liquid crystal aligning agent comprising a polymer having a structural unit represented by the following formula (1) in its main chain,

[0023] [Chemistry 1]

[0024]

[0025] (In formula (1), A represents an organic group that initiates radical polymerization).

[0026] [2] The liquid crystal aligning agent according to [1], wherein the polymer is at least one polymer selected from a polyimide precursor, polyimide, polyurea, and polyamide obtained using a diamine component, and the diamine component contains a diamine containing an organic group that initiates free radical polymerization.

[0027] [3] The liquid crystal aligning agent according to [2], wherein the diamine containing an organic group that initiates radical polymerization is a diamine represented by the following formula (2):

[0028] [Chemistry 2]

[0029]

[0030] (In formula (2), A 1 and A 2 Respectively represent a hydrogen atom or the organic group that initiates free radical polymerization, wherein A 1 and A2 At least one of represents the organic group that initiates free radical polymerization,

[0031] E represents a single bond, -O-, -C(CH3)2-, -NH-, -CO-, -NHCO-, -COO-, -(CH2) m -, -SO2-, or a divalent organic group composed of any combination thereof, m represents an integer of 1 to 8,

[0032] p represents an integer from 0 to 2; when p is 2, multiple A 2 have the above definitions independently; in addition, when p is 0, A 1 Composed of organic groups that initiate free radical polymerization. ).

[0033] [4] The liquid crystal aligning agent according to any one of [1] to [3], wherein the organic group that initiates radical polymerization is a group represented by formula (3):

[0034] [Chemistry 3]

[0035]

[0036] (In formula (3), the dotted line represents the bond to the benzene ring, R 6 represents a single bond, -CH2-, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH2O-, -N(CH3)-, -CON(CH3)-, or -N(CH3)CO-,

[0037] R 7 represents a single bond, or an unsubstituted or fluorine-substituted alkylene group having 1 to 20 carbon atoms, wherein one or more of any -CH2- or -CF2- in the alkylene group may be independently replaced by a group selected from -CH=CH-, a divalent carbocycle and a divalent heterocycle, and further, may be replaced by any of the following groups, i.e., -O-, -COO-, -OCO-, -NHCO-, -CONH-, or -NH-, provided that they are not adjacent to each other.

[0038] R 8 represents an organic group selected from formulae [X-1] to [X-18], [W], [Y], and [Z] that initiates radical polymerization:

[0039] [Chemistry 4]

[0040]

[0041] In formulas [X-1] to [X-18], * represents a bond to R 7, S1 and S2 each independently represent -O-, -NR-, or -S-, R represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, R1 and R2 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms,

[0042] [Chemistry 5]

[0043]

[0044] In the formulas [W], [Y], and [Z], * indicates a bond to R 7 The part, S 3 represents a single bond, -O-, -S-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH2O-, -N(CH3)-, -CON(CH3)-, or -N(CH3)CO-, Ar represents an aromatic hydrocarbon group selected from phenylene, naphthylene, and biphenylene groups which may have an organic group and / or a halogen atom as a substituent, and R 9 and R 10 Each independently represents an alkyl group, an alkoxy group, a benzyl group, or a phenethyl group having 1 to 10 carbon atoms. In the case of an alkyl group or an alkoxy group, R 9 and R 10 Form a ring,

[0045] Q represents any of the following structures,

[0046] [Chemistry 6]

[0047]

[0048] Where R 11 represents -CH2-, -NR-, -O-, or -S-, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, * represents a bond position,

[0049] R 12 represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. ).

[0050] [5] A radical generating film obtained by using the liquid crystal aligning agent according to any one of [1] to [4].

[0051] [6] A method for manufacturing a horizontal electric field liquid crystal unit, comprising:

[0052] A step of preparing a first substrate having a liquid crystal alignment film and a second substrate having the radical generating film described in [5];

[0053] a step of fabricating a unit in such a manner that the radical generating film on the second substrate faces the first substrate; and

[0054] a step of filling a liquid crystal composition containing a liquid crystal and a radical polymerizable compound between the first substrate and the second substrate;

[0055] One of the first substrate and the second substrate is a comb-teeth electrode substrate, and the other is a counter substrate.

[0056] [7] The method for manufacturing a horizontal electric field liquid crystal cell according to [6], wherein the first substrate is a substrate covered with a liquid crystal alignment film having uniaxial alignment properties.

[0057] [8] The method for manufacturing a horizontal electric field liquid crystal cell according to [7], wherein the liquid crystal alignment film having uniaxial alignment properties is a liquid crystal alignment film for horizontal alignment.

[0058] [9] The method for manufacturing a horizontal electric field liquid crystal unit according to any one of [6] to [8], wherein the comb-tooth electrode substrate is an IPS substrate or an FFS substrate.

[0059] Effects of the Invention

[0060] According to the present invention, in order to obtain a horizontal electric field liquid crystal display element with excellent black display quality, high transmittance, and suppressed response time delay as a technical problem of weak anchoring display elements, a liquid crystal alignment agent that can be effectively used in the horizontal electric field liquid crystal display element can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is a schematic cross-sectional view showing an example of the liquid crystal display element of the present invention.

[0062] Figure 2 It is a schematic cross-sectional view showing another example of the liquid crystal display element of the present invention. DETAILED DESCRIPTION

[0063] (Liquid Crystal Alignment Agent)

[0064] The present invention relates to a liquid crystal alignment agent comprising a polymer having a structural unit represented by the above formula (1) in its main chain. Consequently, the liquid crystal alignment agent of the present invention contains an organic group that initiates free radical polymerization. By applying such a composition and curing it to form a film, a liquid crystal alignment film having various functions and fixed therein with groups capable of generating free radicals can be obtained.

[0065] Examples of such an organic group that initiates radical polymerization include a group represented by the above-mentioned formula (3).

[0066] As the organic group represented by a formula selected from the group consisting of [W], [Y] and [Z], the following organic groups are specifically preferred: (b) and (c) are particularly preferred from the viewpoint of reliability of the resulting liquid crystal display element.

[0067] [Chemistry 7]

[0068]

[0069] When using a polymer having an organic group that initiates free radical polymerization, in order to obtain a polymer having a group capable of generating free radicals, it is preferable to use a monomer having a photoreactive side chain, or a monomer having a free radical-generating site on the side chain that decomposes upon ultraviolet irradiation, as a monomer component. The photoreactive side chain comprises at least one selected from methacryloyl, acryloyl, vinyl, allyl, coumarin, styryl, and cinnamoyl groups. On the other hand, it is recognized that free radical-generating monomers themselves may spontaneously polymerize, forming unstable compounds. Therefore, in terms of ease of synthesis, polymers derived from diamines having a free radical-generating site are preferred, and polyimide precursors such as polyamic acid and polyamic acid esters, polyimides, polyureas, and polyamides are more preferred.

[0070] Specifically, such a diamine containing a radical generating site is, for example, a diamine having a side chain capable of generating radicals and polymerizing, and an example thereof includes a diamine represented by the above formula (2).

[0071] In the above formula (2), E represents a single bond, -O-, -C(CH3)2-, -NH-, -CO-, -NHCO-, -COO-, -(CH2) m -, -SO2-, or a divalent organic group composed of any combination thereof, wherein "any combination thereof" includes: -O-(CH2) m -O-, -OC(CH3)2-, -CO-(CH2) m -、-NH-(CH2) m -, -SO2-(CH2) m -、-CONH-(CH2) m -、-CONH-(CH2) m -NHCO-, -COO-(CH2) m -OCO- etc., but not limited to.

[0072] Specific examples of the diamine having a photoreactive group include, but are not limited to, the following compounds. The photoreactive group includes at least one selected from the group consisting of a methacryloyl group, an acryloyl group, a vinyl group, an allyl group, a coumarin group, a styryl group, and a cinnamoyl group.

[0073] [Chemistry 8]

[0074]

[0075] (Where J 1 represents a single bond, -O-, -COO-, -NHCO-, or -NH-, J 2 represents a single bond, or an unsubstituted or fluorine-substituted alkylene group having 1 to 20 carbon atoms.

[0076] The diamine having an organic group represented by a formula selected from the above-mentioned [W], [Y], and [Z] is most preferably a structure represented by the following formula in view of ease of synthesis, versatility, properties, etc., but is not limited thereto.

[0077] [Chemistry 9]

[0078]

[0079] (wherein n is an integer from 2 to 8, and E is a single bond, -O-, -C(CH3)2-, -NH-, -CO-, -NHCO-, -COO-, -(CH2) m -、-SO2-、-O-(CH2) m -O-, -OC(CH3)2-, -CO-(CH2) m -、-NH-(CH2) m -, -SO2-(CH2) m -、-CONH-(CH2) m -、-CONH-(CH2) m -NHCO-, or -COO-(CH2) m -OCO-, m is an integer from 1 to 8. ).

[0080] The above-mentioned diamine can be synthesized by selecting an appropriate synthesis method. The main synthesis methods of the diamine of the present invention are described below. In addition, the method described below is a synthesis example and is not limited to this.

[0081] Basically, it can be synthesized according to the following route.

[0082] [Chemistry 10]

[0083]

[0084] The compound [A] as a precursor can be produced by reacting the compound A' with the compound [C] to introduce a radical-generating group as described below.

[0085] [Chemistry 11]

[0086]

[0087] Here, as a method for obtaining compound [C], for example, compound [D] is reacted with compound [E] to obtain X 1 With X 2 Same, V 1 With V 2 a method for reacting compound [D] with compound [F]; and the like.

[0088] [Chemistry 12]

[0089]

[0090] [Chemistry 13]

[0091]

[0092] Alternatively, as described below, a radical-generating group may be introduced into compound [D] to synthesize compound [G], which may then be reacted with compound [E] to obtain compound [A].

[0093] [Chemistry 14]

[0094]

[0095] In the above formula, X 1 、X 2 、X 3 、X 4 and X 5 Each independently represents a leaving group or a reactive group that causes an addition reaction, a substitution reaction, or a condensation reaction, and R 7 and R 8 In the above formula, A 1 、A 2 The description of formula (2) shown in the claims is synonymous with that of formula (2). 1 and V 2Each independently represents an amino group or an organic group that can be converted into an amino group. Examples of organic groups that can be converted into amino groups include: amino groups with nitro groups or protective groups, isocyanate groups or blocked isocyanate groups, carboxyl groups, amide groups, etc., but are not limited to these. Amino groups with nitro groups or a portion of protective groups, benzophenone imine, and phthalimide can be converted into amino groups by hydrogenation reduction using palladium carbon or iron. Regarding protected amino groups, they can be induced into amino groups by selecting appropriate deprotection conditions. As protected amino groups, Boc (tert-butoxycarbonyl) protected amines, Fmoc (9-fluorenylmethoxycarbonyl) protected amines, benzyl protected amines, benzyloxycarbonyl protected amines, etc. In addition, isocyanates, blocked isocyanates, etc. can be induced into amino groups by heating in the presence of water, and carboxylic acids and amides can be converted into amino groups using Curtius rearrangement and Hofmann rearrangement via isocyanate. On the other hand, according to different A 1 、A 2 Sometimes, there is a change in the step of converting to an amino group, and it is important to appropriately select these methods. The diamine of the present invention can be obtained by synthesizing according to the above method, but this is only an example and is not limited to this.

[0096] The diamines used in the present invention may be used alone or in combination of two or more depending on the liquid crystal orientation when forming a liquid crystal alignment film, the sensitivity in the polymerization reaction when energy is applied, the liquid crystal orientation, the voltage holding property, the stored charge and other properties.

[0097] The amount of the diamine having such a site for undergoing free radical polymerization is not particularly limited, and all of the above-mentioned diamines having a free radical generating site may be used, but it is preferably used in an amount of 5 to 80 mol %, more preferably 10 to 50 mol %, of the total diamine component used when synthesizing the polymer contained in the liquid crystal aligning agent.

[0098] Moreover, when obtaining the polymer used for the liquid crystal aligning agent of this invention from a diamine, you may use together other diamine as a diamine component except the diamine which has the site|part which generates a radical mentioned above. Specific examples include p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, and 3,3'-dicarboxy-4,4'-diaminobiphenyl. Bis(amino)phenyl, 3,3'-difluoro-4,4'-biphenyl, 3,3'-bis(trifluoromethyl)-4,4'-biphenyl, 3,4'-biphenyl, 3,3'-biphenyl, 2,2'-biphenyl, 2,3'-biphenyl, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-diaminodiphenylmethane, 2,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'-sulfonyldiphenyl Aniline, 3,3'-sulfonyldiphenylamine, bis(4-aminophenyl)silane, bis(3-aminophenyl)silane, dimethyl-bis(4-aminophenyl)silane, dimethyl-bis(3-aminophenyl)silane, 4,4'-sulfur diphenylamine, 3,3'-sulfur diphenylamine, 4,4'-diaminodiphenylamine, 3,3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-diaminodiphenylamine, N-methyl(4,4'-diaminodiphenyl)amine, N-methyl(3,3'-diaminodiphenyl)amine, N-methyl(3,4'-diaminodiphenyl)amine, N-methyl(2,2'-diaminodiphenyl)amine, N-methyl( 2,3'-diaminodiphenyl)amine, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 2,2'-diaminobenzophenone, 2,3'-diaminobenzophenone, 1,4-diaminonaphthalene, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 1,8-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 1,2-bis(4-aminophenyl)ethane, 1,2-bis(3-aminophenyl)ethane, 1,3-bis(4-aminophenyl)propane, 1,3-bis(3-aminophenyl)propane, 1,4-bis(4-aminophenyl)butane, 1,4-bis(3-aminophenyl)butane, bis(3,5-diethyl-4-aminophenyl)methane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4'-[1,4-phenylenebis(methylene)]diphenylamine, 4,4'-[1,3-phenylenebis(methylene)]diphenylamine, 3,4'-[1,4-phenylenebis(methylene)]diphenylamine, 3,4'-[1,3-phenylenebis(methylene)]diphenylamine, 3,3'-[1,4-phenylenebis(methylene)]diphenylamine, ,3'-[1,3-phenylenebis(methylene)]diphenylamine, 1,4-phenylenebis[(4-aminophenyl)methanone], 1,4-phenylenebis[(3-aminophenyl)methanone], 1,3-phenylenebis[(4-aminophenyl)methanone], 1,3-phenylenebis[(3-aminophenyl)methanone], 1,4-phenylenebis(4-aminobenzoate), 1,4-phenylenebis(3-aminobenzoate), 1,3-phenylenebis(4-aminobenzoate), 1,3-phenylenebis(3-aminobenzoate), bis(4-aminophenyl)terephthalate, bis(3-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate, N, N'-(1,4-phenylene)bis(4-aminobenzamide), N,N'-(1,3-phenylene)bis(4-aminobenzamide), N,N'-(1,4-phenylene)bis(3-aminobenzamide), N,N'-(1,3-phenylene)bis(3-aminobenzamide), N,N'-bis(4-aminophenyl)terephthalamide, N,N'-bis(3-aminophenyl)terephthalamide, N,N'-bis(4-aminophenyl)isophthalamide, N,N'-bis(3-aminophenyl)isophthalamide, 9,10-bis(4-aminophenyl)anthracene, 4,4'-bis(4-aminophenoxy)diphenyl sulfone, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, 2,2 '-Bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(4-aminophenyl)hexafluoropropane, 2,2'-bis(3-aminophenyl)hexafluoropropane, 2,2'-bis(3-aminophenyl)hexafluoropropane, 2,2'-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2'-bis(4-aminophenyl)propane, 2,2'-bis(3-aminophenyl)propane, 2,2'-bis(3-aminophenyl)propane, trans-1,4-bis(4-aminophenyl)cyclohexane, 3,5-diaminobenzoic acid, 2,5-diaminobenzoic acid, bis(4-aminophenoxy)methane, 1,2-bis(4-aminophenoxy)ethane, 1,3-bis(4-aminophenoxy)propane, 1,3-bis(3-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,4-bis(3-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane, 1,5-bis(3-aminophenoxy)pentane, 1,6-bis(4-aminophenoxy)hexane, 1,6-bis(3-aminophenoxy)hexane, 1,7-bis(4-aminophenoxy)heptane, 1,7-bis(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,8-bis(3-aminophenoxy)octane Aromatic hydrocarbons such as 1,1-bis(4-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1,9-bis(3-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, 1,10-bis(3-aminophenoxy)decane, 1,11-bis(4-aminophenoxy)undecane, 1,11-bis(3-aminophenoxy)undecane, 1,12-bis(4-aminophenoxy)dodecane, 1,12-bis(3-aminophenoxy)dodecane Diamines; aliphatic diamines such as bis(4-aminocyclohexyl)methane and bis(4-amino-3-methylcyclohexyl)methane; aliphatic diamines such as 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane and 1,12-diaminododecane; 1,3-bis[2- Diamines having a urea structure such as [(p-aminophenyl)ethyl]urea, 1,3-bis[2-(p-aminophenyl)ethyl]-1-tert-butoxycarbonylurea; diamines having a nitrogen-containing unsaturated heterocyclic structure such as N-p-aminophenyl-4-p-aminophenyl(tert-butoxycarbonyl)aminomethylpiperidine; diamines having an N-Boc group (Boc represents a tert-butoxycarbonyl group) such as N-tert-butoxycarbonyl-N-(2-(4-aminophenyl)ethyl)-N-(4-aminobenzyl)amine.

[0099] These other diamines can be used alone or in combination of two or more depending on the liquid crystal orientation when forming a liquid crystal alignment film, sensitivity in a polymerization reaction, voltage holding characteristics, stored charge, and other characteristics.

[0100] In the synthesis when the polymer is a polyamic acid, the tetracarboxylic dianhydride reacted with the above-mentioned diamine component is not particularly limited. Specifically, pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7-anthracenetetracarboxylic acid, 1,2,5,6-anthracenetetracarboxylic acid, 3,3',4,4-biphenyltetracarboxylic acid, 2,3,3',4'-biphenyltetracarboxylic acid, bis(3,4-dicarboxyphenyl)ether, 3,3',4,4'-benzophenonetetracarboxylic acid, bis(3,4-dicarboxyphenyl)sulfone, bis(3,4-dicarboxyphenyl)methane, 2,2-bis(3,4-dicarboxyphenyl)propane, 1,1,1,3,3,3-hexafluoro-2,2-bis(3,4-dicarboxyphenyl)propane, bis( 3,4-dicarboxyphenyl)dimethylsilane, bis(3,4-dicarboxyphenyl)diphenylsilane, 2,3,4,5-pyridinetetracarboxylic acid, 2,6-bis(3,4-dicarboxyphenyl)pyridine, 3,3',4,4'-diphenylsulfonetetracarboxylic acid, 3,4,9,10-perylenetetracarboxylic acid, 1,3-diphenyl-1,2,3,4-cyclobutanetetracarboxylic acid, oxybis(o-phthalic acid), 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid , 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cycloheptanetetracarboxylic acid, 2,3,4,5-tetrahydrofurantetracarboxylic acid, 3,4-dicarboxy-1-cyclohexylsuccinic acid, 2,3,5-tricarboxycyclopentylacetic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic acid, bicyclo[4.3.0]nonane-2,4,7,9-tetracarboxylic acid, bicyclo[4.4.0]decane-2,4,7,9-tetracarboxylic acid, bicyclo[4.4.0]decane-2,4,8,10-tetracarboxylic acid, tricyclo[6.3.0]octane-2,4,6,8-tetracarboxylic acid, Dianhydrides of tetracarboxylic acids such as undecane-3,5,9,11-tetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid, 5-(2,5-dioxotetrahydrofuranyl)-3-methyl-3-cyclohexane-1,2-dicarboxylic acid, tetracyclo[6.2.1.1<3,6>.0<2,7>]dodecane-4,5,9,10-tetracarboxylic acid, 3,5,6-tricarboxynorbornane-2:3,5:6-dicarboxylic acid, and 1,2,4,5-cyclohexanetetracarboxylic acid.

[0101] Of course, the tetracarboxylic dianhydride may be used alone or in combination of two or more depending on the liquid crystal orientation when forming a radical generating film, sensitivity in polymerization reaction, voltage holding characteristics, stored charge and other characteristics.

[0102] In the synthesis when the polymer is polyamic acid ester, the structure of the tetracarboxylic acid dialkyl ester to be reacted with the above-mentioned diamine component is not particularly limited, and specific examples thereof are given below.

[0103] Specific examples of the aliphatic tetracarboxylic acid diester include 1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,2,3,4-cyclopentanetetracarboxylic acid dialkyl ester, 2,3,4,5-tetrahydrofurantetracarboxylic acid dialkyl ester, 1,2,4,5-cyclohexanetetracarboxylic acid dialkyl ester, 3,4-dicarboxy-1-cyclohexylsuccinic acid dialkyl ester, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid dialkyl ester, 1,2,3,4-butanetetracarboxylic acid dialkyl ester, bicyclo[3.3.0] ] octane-2,4,6,8-tetracarboxylic acid dialkyl ester, 3,3,'4,4'-dicyclohexyltetracarboxylic acid dialkyl ester, 2,3,5-tricarboxycyclopentyl acetic acid dialkyl ester, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic acid dialkyl ester, tricyclo[4.2.1.0<2,5>]nonane-3,4,7,8-tetracarboxylic acid-3,4:7,8-dialkyl ester, hexacyclo[6.6.0.1<2,7>.0<3,6>.1<9,14>.0<10,13>]hexadecane-4,5,11,12-tetracarboxylic acid 4,5:11,12-dialkyl ester, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid dialkyl ester, etc.

[0104] Examples of the aromatic tetracarboxylic acid dialkyl esters include pyromellitic acid dialkyl esters, 3,3',4,4'-biphenyltetracarboxylic acid dialkyl esters, 2,2',3,3'-biphenyltetracarboxylic acid dialkyl esters, 2,3,3',4-biphenyltetracarboxylic acid dialkyl esters, 3,3',4,4'-benzophenonetetracarboxylic acid dialkyl esters, 2,3,3',4'-benzophenonetetracarboxylic acid dialkyl esters, bis(3,4-dicarboxyphenyl)ether dialkyl esters, bis(3,4-dicarboxyphenyl)sulfone dialkyl esters, 1,2,5,6-naphthalenetetracarboxylic acid dialkyl esters, and 2,3,6,7-naphthalenetetracarboxylic acid dialkyl esters.

[0105] In the synthesis of a polymer of polyurea, the diisocyanate to be reacted with the diamine component is not particularly limited, and any diisocyanate can be used depending on availability, etc. The specific structure of the diisocyanate is shown below.

[0106] [Chemistry 15]

[0107]

[0108] Where R 22 and R 23 It represents an aliphatic hydrocarbon having 1 to 10 carbon atoms.

[0109] Aliphatic diisocyanates represented by K-1 to K-5 have poor reactivity but offer the advantage of improved solvent solubility. Aromatic diisocyanates represented by K-6 and K-7 have high reactivity and improved heat resistance, but have disadvantages such as reduced solvent solubility. In terms of versatility and properties, K-1, K-7, K-8, K-9, and K-10 are particularly preferred. From the perspective of electrical properties, K-12 is preferred, and from the perspective of liquid crystal orientation, K-13 is preferred. More than one diisocyanate may be used simultaneously, preferably depending on the desired properties for various applications.

[0110] Alternatively, a portion of the diisocyanate may be replaced with the above-described tetracarboxylic dianhydride, and the polyamide may be used as a copolymer of polyamic acid and polyurea. Alternatively, the polyamide may be used as a copolymer of polyimide and polyurea by chemical imidization.

[0111] In the synthesis of a polyamide polymer, the structure of the dicarboxylic acid to be reacted is not particularly limited, but specific examples are as follows. Specific examples of aliphatic dicarboxylic acids include malonic acid, oxalic acid, dimethylmalonic acid, succinic acid, fumaric acid, glutaric acid, adipic acid, hexanedioic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, 3,3-diethylsuccinic acid, azelaic acid, sebacic acid, and suberic acid.

[0112] Examples of the alicyclic dicarboxylic acid include 1,1-cyclopropanedicarboxylic acid, 1,2-cyclopropanedicarboxylic acid, 1,1-cyclobutanedicarboxylic acid, 1,2-cyclobutanedicarboxylic acid, 1,3-cyclobutanedicarboxylic acid, 3,4-diphenyl-1,2-cyclobutanedicarboxylic acid, 2,4-diphenyl-1,3-cyclobutanedicarboxylic acid, 1-cyclobutene-1,2-dicarboxylic acid, 1-cyclobutene-3,4-dicarboxylic acid, 1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,1-cyclohexanedicarboxylic acid, and 1,2-cyclohexanedicarboxylic acid. dicarboxylic acids, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,4-(2-norbornene)dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid, bicyclo[2.2.2]octane-1,4-dicarboxylic acid, bicyclo[2.2.2]octane-2,3-dicarboxylic acid, 2,5-dioxo-1,4-bicyclo[2.2.2]octanedicarboxylic acid, 1,3-adamantanedicarboxylic acid, 4,8-dioxo-1,3-adamantanedicarboxylic acid, 2,6-spiro[3.3]heptanedicarboxylic acid, 1,3-adamantanedicarboxylic acid, camphoric acid, and the like.

[0113] Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, 5-methylisophthalic acid, 5-tert-butylisophthalic acid, 5-aminoisophthalic acid, 5-hydroxyisophthalic acid, 2,5-dimethylterephthalic acid, tetramethylterephthalic acid, 1,4-naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 1,4-anthracene dicarboxylic acid, 1,4-anthraquinone dicarboxylic acid, 2,5-biphenyl dicarboxylic acid, 4,4'-biphenyl dicarboxylic acid, 1,5-biphenylene dicarboxylic acid, 4,4'-terphenyl dicarboxylic acid, 4,4'-diphenylmethane dicarboxylic acid, 4,4'-diphenylethane dicarboxylic acid, 4,4'-diphenylpropane dicarboxylic acid, 4,4'-diphenylhexacarboxylic acid, Dicarboxylic acids such as fluoropropane dicarboxylic acid, 4,4'-diphenylether dicarboxylic acid, 4,4'-bibenzyl dicarboxylic acid, 4,4'-stilbene dicarboxylic acid, 4,4'-tolane dicarboxylic acid, 4,4'-carbonyl dibenzoic acid, 4,4'-sulfonyl dibenzoic acid, 4,4'-dithiodibenzoic acid, p-phenylenedicarboxylic acid, 3,3'-p-phenylenedipropionic acid, 4-carboxycinnamic acid, p-phenylenedicarboxylic acid, 3,3'-[4,4'-(methylenedi-p-phenylene)]dipropionic acid, 4,4'-[4,4'-(oxydi-p-phenylene)]dipropionic acid, 4,4'-[4,4'-(oxydi-p-phenylene)]dibutyric acid, (isopropylidenedi-p-phenylenedioxy)dibutyric acid, and bis(p-carboxyphenyl)dimethylsilane.

[0114] Examples of the dicarboxylic acid containing a heterocyclic ring include 1,5-(9-oxofluorene)dicarboxylic acid, 3,4-furandicarboxylic acid, 4,5-thiazoledicarboxylic acid, 2-phenyl-4,5-thiazoledicarboxylic acid, 1,2,5-thiadiazole-3,4-dicarboxylic acid, 1,2,5-oxadiazole-3,4-dicarboxylic acid, 2,3-pyridinedicarboxylic acid, 2,4-pyridinedicarboxylic acid, 2,5-pyridinedicarboxylic acid, 2,6-pyridinedicarboxylic acid, 3,4-pyridinedicarboxylic acid, and 3,5-pyridinedicarboxylic acid.

[0115] The above-mentioned various dicarboxylic acids can be dicarboxylic acids with acid dihalides or acid anhydride structures. From the viewpoint of maintaining the orientation of liquid crystal molecules, these dicarboxylic acids are particularly preferably dicarboxylic acids that can form polyamides of linear structures. Among them, it is preferred to use terephthalic acid, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,4'-diphenylethanedicarboxylic acid, 4,4'-diphenylpropanedicarboxylic acid, 4,4'-diphenylhexafluoropropanedicarboxylic acid, 2,2-bis(phenyl)propanedicarboxylic acid, 4,4-terphenyldicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 2,5-pyridinedicarboxylic acid or acid dihalides of these substances. These compounds sometimes have isomers or mixtures containing them. In addition, two or more compounds can also be used in combination. In addition, the dicarboxylic acids used in the present invention are not limited to the above-mentioned exemplified compounds.

[0116] When a polyamic acid, polyamic acid ester, polyurea, or polyamide is obtained by reacting a diamine (also referred to as a "diamine component") as a raw material with a component selected from tetracarboxylic dianhydride (also referred to as a "tetracarboxylic dianhydride component"), a tetracarboxylic diester, a diisocyanate, and a dicarboxylic acid as a raw material, a known synthesis method can be used. Generally, a diamine component and one or more components selected from tetracarboxylic dianhydride components, tetracarboxylic diesters, diisocyanates, and dicarboxylic acids are reacted in an organic solvent.

[0117] The reaction of the diamine component and the tetracarboxylic dianhydride component is advantageous in that it proceeds relatively easily in an organic solvent and no by-products are generated.

[0118] The organic solvent used in the above reaction is not particularly limited as long as it dissolves the generated polymer. Furthermore, even an organic solvent that does not dissolve the polymer can be mixed with the above solvent to the extent that the generated polymer does not precipitate. In addition, since the water content in the organic solvent hinders the polymerization reaction and further causes hydrolysis of the generated polymer, it is preferred to use a dehydrated organic solvent.

[0119] Examples of the organic solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylformamide, N-methylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropionamide, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethylphosphoric triamide, γ-butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, and the like. , ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol tert-butyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol, diethylene glycol monoacetic acid Ester, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, dioxane, n-hexane, n- Pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diethylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, 2-ethyl-1-hexanol, etc. These organic solvents may be used alone or in combination.

[0120] When reacting a diamine component and a tetracarboxylic dianhydride component in an organic solvent, the following methods can be used: stirring a solution obtained by dispersing or dissolving the diamine component in an organic solvent and then adding the tetracarboxylic dianhydride component directly, or adding the tetracarboxylic dianhydride component by dispersing or dissolving the diamine component in an organic solvent; conversely, adding the diamine component to a solution obtained by dispersing or dissolving the tetracarboxylic dianhydride component in an organic solvent; or alternating the addition of the tetracarboxylic dianhydride component and the diamine component. Any of these methods can be used. Furthermore, when the diamine component or the tetracarboxylic dianhydride component is composed of multiple compounds, the compounds can be reacted in a premixed state, reacted separately in sequence, or low molecular weight compounds obtained by the separate reactions can be mixed and reacted to produce a high molecular weight compound.

[0121] The temperature for reacting the diamine component and the tetracarboxylic dianhydride component can be selected at any temperature, for example, within the range of -20 to 100° C., preferably -5 to 80° C. The reaction can be carried out at any concentration, for example, the total amount of the diamine component and the tetracarboxylic dianhydride component relative to the reaction solution is 1 to 50% by mass, preferably 5 to 30% by mass.

[0122] The ratio of the total molar number of the tetracarboxylic dianhydride components to the total molar number of the diamine components in the above-mentioned polymerization reaction can be selected as an arbitrary value according to the molecular weight of the polyamic acid to be obtained. As in a conventional polycondensation reaction, the closer this molar ratio is to 1.0, the greater the molecular weight of the polyamic acid produced. As a preferred range, it is 0.8 to 1.2.

[0123] The method for synthesizing the polymer used in the present invention is not limited to the above-mentioned method, and in the case of synthesizing polyamic acid, it is the same as the synthetic method of common polyamic acid, instead of the above-mentioned tetracarboxylic dianhydride, tetracarboxylic acid derivatives such as tetracarboxylic acid or tetracarboxylic acid dihalide of corresponding structure are used, and known methods are utilized to react, and corresponding polyamic acid can also be obtained. In addition, in the case of synthesizing polyurea, diamine is reacted with diisocyanate. When manufacturing polyamic acid ester or polyamide, diamine and the component selected from tetracarboxylic acid diester and dicarboxylic acid are made to react with diamine in the presence of a known condensing agent or after being derived as an acid halide using a known method, and then reacted with diamine.

[0124] As the method for making the above-mentioned polyamic acid imidization to make polyimide, the thermal imidization with the solution of polyamic acid directly heated, the catalyst imidization of adding a catalyst in the solution of polyamic acid can be enumerated. In addition, from the viewpoint of being able to improve voltage holding ratio, the imidization rate of polyamic acid to polyimide is preferably more than 30%, more preferably 30~99%. On the other hand, from the viewpoint of suppressing whitening characteristic, i.e., the precipitation of polymer in varnish, it is preferably below 70%. Taking two kinds of characteristics into consideration, it is more preferably 40~80%.

[0125] The temperature when thermally imidizing the polyamic acid in the solution is usually 100 to 400° C., preferably 120 to 250° C., and the imidization reaction is preferably carried out while removing water generated by the imidization reaction to the outside of the system.

[0126] The catalytic imidization of polyamic acid can be carried out by adding a basic catalyst and an acid anhydride to a solution of polyamic acid and stirring at -20 to 250°C, preferably 0 to 180°C. The amount of the basic catalyst is usually 0.5 to 30 times the molar amount of the amic acid group, preferably 2 to 20 times; the amount of the acid anhydride is usually 1 to 50 times the molar amount of the amic acid group, preferably 3 to 30 times. As the basic catalyst, pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, etc. can be mentioned. Among them, pyridine has a moderate alkalinity for the reaction to proceed, so it is preferred. As the acid anhydride, acetic anhydride, trimellitic anhydride, pyromellitic anhydride, etc. can be mentioned. Among them, if acetic anhydride is used, purification after the reaction is easier, so it is preferred. The imidization rate based on catalytic imidization can be controlled by adjusting the amount of catalyst, reaction temperature, reaction time, etc.

[0127] When the polymer produced is recovered from the reaction solution of the polymer, the reaction solution is put into a poor solvent to precipitate it. Examples of the poor solvent for generating the precipitate include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, water, and the like. The polymer put into the poor solvent to precipitate it can be dried at room temperature or under normal pressure or reduced pressure, or by heating, after being recovered by filtration. In addition, if the operation of redissolving the polymer recovered by precipitation in an organic solvent and then reprecipitating and recovering it is repeated 2 to 10 times, the impurities in the polymer can be reduced. Examples of the poor solvent at this time include alcohols, ketones, hydrocarbons, and the like. If three or more poor solvents selected from these are used, the efficiency of the purification can be further improved, and therefore it is preferred.

[0128] As the polymer of the present invention, from the viewpoint of use as a liquid crystal aligning agent, at least one selected from a polyimide precursor containing a structural unit represented by the following formula (6) and a polyimide which is an imide product thereof is more preferable.

[0129] [Chemistry 16]

[0130]

[0131] In the above formula (6), X1 is a tetravalent organic group derived from a tetracarboxylic acid derivative, Y1 is a divalent organic group derived from a diamine of formula (2), and R4 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. From the viewpoint of ease of imidization by heating, R4 is preferably a hydrogen atom, a methyl group, or an ethyl group.

[0132] <Tetracarboxylic Dianhydride>

[0133] X1 is a tetravalent organic group derived from a tetracarboxylic acid derivative, and its structure is not particularly limited. Furthermore, X1 in the polyimide precursor is appropriately selected based on the solubility of the polymer in the solvent, the coating properties of the liquid crystal alignment agent, the orientation of the liquid crystal when formed into a liquid crystal alignment film, the voltage holding ratio, the degree of stored charge, and other required properties. X1 may be present as a single species or as a mixture of two or more species in the same polymer.

[0134] Specific examples of X1 include the structures of formulae (X-1) to (X-46) described in items 13 and 14 of International Publication No. 2015 / 119168.

[0135] Preferred structures of X1 are shown below, but the present invention is not limited thereto.

[0136] [Chemistry 17]

[0137]

[0138] [Chemistry 18]

[0139]

[0140] Among the above structures, (A-1) and (A-2) are particularly preferred from the perspective of photo-orientation; (A-4) is particularly preferred from the perspective of further improving the relaxation rate of accumulated charges; and (A-15) to (A-17) are particularly preferred from the perspective of further improving the liquid crystal orientation and the relaxation rate of accumulated charges.

[0141] <Polymer (Other Structural Units)>

[0142] The polyimide precursor containing the structural unit represented by formula (6) may contain at least one selected from the structural unit represented by the following formula (7) and polyimides which are imide products thereof, within a range not impairing the effects of the present invention.

[0143] [Chemistry 19]

[0144]

[0145] In formula (7), X2 is a tetravalent organic group derived from a tetracarboxylic acid derivative; Y2 is a divalent organic group derived from a diamine that does not contain the structure of formula (1); R5 has the same definition as R4 in formula (6) above and represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; and R6 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Preferably, at least one of the two R6s is a hydrogen atom.

[0146] Specific examples of X2, including preferred examples, include structures identical to those exemplified by X1 in formula (6). Furthermore, Y2 in the polyimide precursor is a divalent organic group derived from a diamine that does not contain a structure of formula (1), and its structure is not particularly limited. Furthermore, Y2 is appropriately selected based on the degree of desired characteristics such as the solubility of the polymer in a solvent, the coating properties of a liquid crystal alignment agent, the orientation of the liquid crystal when forming a liquid crystal alignment film, the voltage holding rate, and the accumulated charge, and may be one or more in the same polymer.

[0147] Specific examples of Y2 include: the structure of formula (2) described in item 4 of International Publication No. 2015 / 119168, and the structures of formulas (Y-1) to (Y-97) and (Y-101) to (Y-118) described in items 8 to 12; the divalent organic group obtained by removing two amino groups from formula (2) described in item 6 of International Publication No. 2013 / 008906; The divalent organic group obtained by removing two amino groups from formula (1) as described in item 8; the structure of formula (3) as described in item 8 of International Publication No. 2015 / 060360; the divalent organic group obtained by removing two amino groups from formula (1) as described in item 8 of Japanese Patent Publication No. 2012-173514; the divalent organic group obtained by removing two amino groups from formulas (A) to (F) as described in item 9 of International Publication No. 2010-050523, etc.

[0148] Preferred structures of Y2 are shown below, but the present invention is not limited thereto.

[0149] [Chemistry 20]

[0150]

[0151] [Chemistry 21]

[0152]

[0153] [Chemistry 22]

[0154]

[0155] [Chemistry 23]

[0156]

[0157] Among the above structures, from the viewpoint of further improving the film hardness, (B-28), (B-29), etc. are particularly preferred; from the viewpoint of further improving the liquid crystal orientation, (B-1) to (B-3), etc. are particularly preferred; from the viewpoint of further improving the relaxation rate of the accumulated charge, (B-14) to (B-18) and (B-27), etc. are particularly preferred; from the viewpoint of further improving the voltage holding rate, (B-26), etc. are particularly preferred.

[0158] When the polyimide precursor containing the structural unit represented by formula (6) also contains the structural unit represented by formula (7), the structural unit represented by formula (6) is preferably 5 mol% to 100 mol%, more preferably 10 mol% to 50 mol%, based on the total of formula (6) and formula (7).

[0159] Examples of polyimides having a bivalent group represented by formula (1) in the main chain include polyimides obtained by ring-closing the above-mentioned polyimide precursor. In such polyimides, the ring-closure ratio of the amic acid group (also referred to as the imidization ratio) does not necessarily need to be 100% and can be arbitrarily adjusted according to the application or purpose.

[0160] Examples of a method for imidating a polyimide precursor include thermal imidation in which a solution of a polyimide precursor is directly heated, and catalytic imidation in which a catalyst is added to a solution of a polyimide precursor.

[0161] In addition, when the liquid crystal alignment film is composed of a polymer containing an organic group that initiates free radical polymerization, the liquid crystal alignment agent used in the present invention may contain other polymers in addition to the polymer containing an organic group that initiates free radical polymerization. In this case, the content of the other polymer in the total polymer components is preferably 5 to 95% by mass, more preferably 30 to 70% by mass.

[0162] Taking into account the strength of the liquid crystal alignment film obtained by applying the liquid crystal alignment agent, the workability during coating formation, the uniformity of the coating, etc., the molecular weight of the polymer contained in the liquid crystal alignment agent is preferably 5,000 to 1,000,000, and more preferably 10,000 to 150,000, as measured by the weight average molecular weight measured by GPC (Gel Permeation Chromatography).

[0163] The liquid crystal alignment agent may contain an organic solvent that dissolves or disperses the polymer component and other components used when necessary. Such an organic solvent is not particularly limited, and for example, the organic solvents exemplified in the synthesis of the above-mentioned polyamic acid can be cited. Among them, from the viewpoint of solubility, preferably N- methyl -2- pyrrolidone, γ- butyrolactone, N- ethyl -2- pyrrolidone, 1,3- dimethyl -2- imidazolidinone, 3- methoxy -N, N- dimethylpropionamide, etc. are preferred. Particularly preferably, N- methyl -2- pyrrolidone or N- ethyl -2- pyrrolidone, a mixed solvent of two or more can also be used.

[0164] Moreover, it is preferable to mix and use the solvent which improves the uniformity or smoothness of a coating film and the organic solvent which has high solubility with respect to the component contained in a liquid crystal aligning agent.

[0165] Examples of the solvent that improves the uniformity or smoothness of the coating film include isopropyl alcohol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, butyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethyl carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether ... tert-Butyl alcohol ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl Isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, n-hexane, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isopentyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3- Ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxypropionic acid propyl ester, 3-methoxypropionic acid butyl ester, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy) propanol, 2-ethyl-1-hexanol, etc. These solvents can be mixed with multiple. When using these solvents, it is preferably 5 to 80% by mass of the total solvent contained in the liquid crystal aligning agent, and more preferably 20 to 60% by mass.

[0166] The liquid crystal aligning agent may contain components other than those mentioned above. Examples thereof include compounds that improve film thickness uniformity or surface smoothness when the liquid crystal aligning agent is applied, compounds that improve adhesion between the liquid crystal aligning film and the substrate, and compounds that further improve film strength of the liquid crystal aligning film.

[0167] As compounds for improving the uniformity of film thickness or surface smoothness, fluorine-based surfactants, silicone-based surfactants, nonionic surfactants, etc. can be mentioned. More specifically, for example, Eftop EF301, EF303, EF352 (Mitsubishi Materials Electronic Chemicals Co., Ltd.), MEGAFAC F171, F173, R-30 (DIC Corporation), FLUORAD FC430, FC431 (3M Company), Asahi Guard AG710, SURFLON S-382, SC101, SC102, SC103, SC104, SC105, SC106 (AGC Corporation) etc. can be mentioned. When using these surfactants, the usage ratio is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, relative to 100 parts by mass of the total amount of the polymer contained in the liquid crystal aligning agent.

[0168] Specific examples of compounds that improve the adhesion between the liquid crystal alignment film and the substrate include compounds containing functional silanes and compounds containing epoxy groups. For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, Triethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl- 3-Aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(oxyethylene)-3-aminopropyltrimethoxysilane, N-bis(oxyethylene)-3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol diglycidyl ether, 2,2 -Dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N,N,N',N'-tetraglycidyl-m-phenylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, 3-(N-allyl-N-glycidyl)aminopropyltrimethoxysilane, 3-(N,N-diglycidyl)aminopropyltrimethoxysilane, etc.

[0169] In order to further improve the film strength of the liquid crystal alignment film, a phenol compound such as 2,2'-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane or tetrakis(methoxymethyl)bisphenol may be added. When such a compound is used, the amount thereof is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, relative to 100 parts by mass of the total amount of the polymer contained in the radical-generating film-forming composition.

[0170] Furthermore, in addition to the above, a dielectric or conductive substance may be added to the liquid crystal aligning agent for the purpose of changing electrical properties such as the dielectric constant and conductivity of the liquid crystal aligning film.

[0171] Furthermore, the liquid crystal aligning agent of the present invention contains an organic group that initiates free radical polymerization and has the ability to generate free radicals. Therefore, in this specification, the liquid crystal aligning agent of the present invention is also referred to as a free radical generating film-forming composition. In addition, a film obtained from the liquid crystal aligning agent of the present invention is also referred to as a free radical generating film.

[0172] (Radical Generating Film and Liquid Crystal Alignment Film)

[0173] The radical-generating film of this embodiment is obtained using the above-mentioned radical-generating film-forming composition. For example, the radical-generating film-forming composition used in the present invention can be applied to a substrate, dried, and sintered, and the resulting cured film can be used directly as the radical-generating film. Alternatively, the cured film can be rubbed, irradiated with polarized light or light of a specific wavelength, or treated with an ion beam, or used as an alignment film for a PSA and then irradiated with UV light in a liquid crystal display element filled with liquid crystal.

[0174] Examples of the method for applying the radical-generating film-forming composition include spin coating, printing, inkjet, spray coating, and roll coating. However, transfer printing is widely used industrially from the perspective of productivity and can also be preferably used in the present invention.

[0175] The substrate on which the radical-generating film-forming composition is applied is not particularly limited as long as it is a highly transparent substrate. Specific examples include glass plates and plastic plates such as polycarbonate, poly(meth)acrylate, polyethersulfone, polyarylate, polyurethane, polysulfone, polyether, polyetherketone, trimethylpentene, polyolefin, polyethylene terephthalate, (meth)acrylonitrile, triacetyl cellulose, diacetyl cellulose, and cellulose acetate butyrate.

[0176] A drying step after applying the radical-generating film-forming composition is not necessarily required, but it is preferably included if the time from application to sintering varies for each substrate, or if sintering is not performed immediately after application. Drying is not particularly limited as long as the solvent is removed to a degree that prevents deformation of the coating film due to transport of the substrate, etc. For example, drying on a hot plate at a temperature of 40°C to 150°C, preferably 60°C to 100°C, for 0.5 to 30 minutes, preferably 1 to 5 minutes, can be used.

[0177] The coating film formed by applying the free radical generating film-forming composition by the above method can be fired to form a cured film. At this time, the sintering temperature can usually be carried out at any temperature of 100 to 350°C, preferably 140 to 300°C, more preferably 150 to 230°C, and further preferably 160 to 220°C. Regarding the sintering time, it can usually be fired within any time of 5 to 240 minutes. It is preferably 10 to 90 minutes, more preferably 20 to 90 minutes. Heating can usually be carried out using known methods, such as a hot plate, a hot air circulation oven, an IR (infrared) oven, a belt furnace, etc.

[0178] The thickness of the cured film can be selected as needed, but is preferably 5 nm or more, more preferably 10 nm or more. In this case, the reliability of the liquid crystal display element is easily achieved, which is therefore preferred. Furthermore, the thickness of the cured film is preferably 300 nm or less, more preferably 150 nm or less. In this case, the power consumption of the liquid crystal display element does not become particularly high, which is therefore preferred.

[0179] The substrate having the radical-generating film can be obtained in the above manner, but the radical-generating film can also be subjected to a uniaxial orientation treatment. Examples of methods for the uniaxial orientation treatment include photo-alignment, oblique deposition, friction, and magnetic field-induced uniaxial orientation treatment.

[0180] When the orientation treatment is performed by rubbing treatment in one direction, for example, the substrate is moved so that the rubbing cloth comes into contact with the film while a rubbing roller around which the rubbing cloth is wound is rotated.

[0181] When imparting liquid crystal alignment ability to the coating film through photo-alignment treatment, the radiation irradiated to the coating film can be, for example, ultraviolet light or visible light having a wavelength of 150 to 800 nm. When the radiation is polarized light, it can be linearly polarized light or partially polarized light. Furthermore, when the radiation used is linearly polarized light or partially polarized light, irradiation can be performed perpendicular to the substrate surface, obliquely, or in combination thereof. When irradiating with unpolarized radiation, the irradiation direction is oblique.

[0182] As the light source used, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, etc. can be used. Ultraviolet rays in a preferred wavelength range can be obtained by using a light source in combination with, for example, a filter or a diffraction grating. The radiation dose is preferably 10 to 2000 mJ / cm 2 , more preferably 30 to 1000 mJ / cm 2 .

[0183] In order to improve reactivity, the coating film may be irradiated with light while being heated. The temperature during heating is usually 30 to 250°C, preferably 40 to 200°C, and more preferably 50 to 150°C.

[0184] In addition, when ultraviolet rays containing light with a wavelength of 150 to 800 nm are used, the light-irradiated film obtained in the above process can be used directly as a liquid crystal alignment film, or the light-irradiated film can be subjected to calcination, washing with water or an organic solvent, or a combination thereof. The calcination temperature at this time is preferably 80 to 300°C, more preferably 80 to 250°C. The calcination time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. In addition, the number of calcinations can be performed once or twice or more. The photo-alignment treatment here is equivalent to a treatment of light irradiation in a state not in contact with the liquid crystal layer.

[0185] The organic solvent used in the above-mentioned washing is not particularly limited. Specific examples include methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, and cyclohexyl acetate.

[0186] The liquid crystal unit involved in the present invention can use the free radical generating film of the present invention as the liquid crystal alignment film arranged on one side of the substrate; and can use a commonly used liquid crystal alignment film as the liquid crystal alignment film arranged on the other side of the substrate.

[0187] The liquid crystal aligning film of this embodiment arranged on the other substrate side is obtained by the same method as that of the radical generating film except that a generally used liquid crystal aligning agent is used instead of the above-mentioned radical generating film-forming composition.

[0188] In addition, the substrate to which the radical-generating film-forming composition is applied and the substrate to which the liquid crystal alignment agent is applied are preferably any of the above-mentioned substrates on which a transparent electrode for driving the liquid crystal is formed. For substrates that can be used for IPS-type liquid crystal display elements, electrode patterns such as standard IPS comb-tooth electrodes, PSA herringbone electrodes, and protrusion patterns such as MVA can also be used.

[0189] In addition, in a high-performance element such as a TFT type element, a structure in which an element such as a transistor is formed between an electrode for driving liquid crystal and a substrate can be used.

[0190] When a transmissive liquid crystal display element is desired, the substrate described above is generally used. However, when a reflective liquid crystal display element is desired, an opaque substrate such as a silicon wafer can also be used as long as only one side of the substrate is used. In this case, the electrodes formed on the substrate can also be made of a material such as aluminum that reflects light.

[0191] In addition, when rubbing the liquid crystal orientation film on the substrate having comb-tooth electrodes, the rubbing direction can be selected according to the electrical properties of the liquid crystal, but when using liquid crystal with positive dielectric anisotropy, the rubbing direction is preferably roughly the same as the extension direction of the comb-tooth electrodes.

[0192] (Liquid Crystal Cell)

[0193] A substrate (first substrate) having a liquid crystal alignment film and a substrate (second substrate) having a free radical generating film formed on the substrate by the above method are arranged in a manner such that the free radical generating film and the liquid crystal alignment film are facing each other, and a spacer is clamped and fixed with a sealant. A liquid crystal composition containing a liquid crystal and a free radical polymerizable compound is injected and sealed to obtain a liquid crystal cell of the present invention. At this time, the size of the spacer used is generally 1 to 30 μm, preferably 2 to 10 μm. In addition, by making the orientation direction of the first substrate parallel to the orientation direction of the second substrate, it can be used in IPS mode or FFS mode. If it is arranged in a manner perpendicular to the rubbing direction, it can be used in twisted nematic mode.

[0194] Preferably, any one of the first substrate and the second substrate is a comb-teeth electrode substrate.

[0195] The alignment film formed on the first substrate may be a known liquid crystal alignment film or the radical generating film of the present invention, and may be appropriately selected depending on the intended purpose.

[0196] The alignment film formed on the first substrate may be subjected to a uniaxial alignment treatment.

[0197] In addition, it is preferable to form a liquid crystal alignment film for horizontal alignment that has been subjected to a uniaxial alignment treatment on the first substrate.

[0198] The method of injecting a liquid crystal composition containing a liquid crystal and a free radical polymerizable compound is not particularly limited, and examples thereof include: a vacuum method in which the interior of the prepared liquid crystal unit is depressurized and then a mixture containing a liquid crystal and a polymerizable compound is injected; a dropwise method in which a mixture containing a liquid crystal and a polymerizable compound is added dropwise and then sealed.

[0199] <Liquid Crystal Composition Containing Liquid Crystal and Radically Polymerizable Compound>

[0200] In the preparation of the liquid crystal display element of the present invention, the polymerizable compound used with the liquid crystal is not particularly limited as long as it is a free radical polymerizable compound, for example, a compound having one or more polymerizable reactive groups in one molecule. Preferably, it is a compound having one polymerizable reactive group in one molecule (hereinafter sometimes referred to as "a compound having a polymerizable group with monofunctionality", "a compound having a monofunctional polymerizable group", etc.). The polymerizable reactive group is preferably a free radical polymerizable reactive group, such as a vinyl bond.

[0201] At least one of the radical polymerizable compounds is preferably a compound having compatibility with liquid crystals and having one polymerizable reactive group in one molecule, that is, a compound having a monofunctional radical polymerizable group.

[0202] Furthermore, the polymerizable group of the radical polymerizable compound is preferably a polymerizable group selected from the following structures.

[0203] [Chemistry 24]

[0204]

[0205] (wherein, * represents a site bonded to a portion of the compound molecule other than the polymerizable reactive group; R b represents a straight-chain alkyl group having 2 to 8 carbon atoms, and E represents a single bond, -O-, -NR c -, -S-, ester bond and amide bond. c represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms).

[0206] In the liquid crystal composition containing a liquid crystal and a radically polymerizable compound, it is preferred that the radically polymerizable compound contained therein satisfies the requirement that the Tg of a polymer obtained by polymerization of the radically polymerizable compound is 100° C. or lower.

[0207] The compound having a monofunctional free radical polymerizable group is a compound having a reactive group capable of undergoing free radical polymerization in the presence of an organic free radical, and examples thereof include: methacrylate monomers such as tert-butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, lauryl methacrylate, and n-octyl methacrylate; acrylate monomers such as tert-butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, benzyl acrylate, lauryl acrylate, and n-octyl acrylate; styrene, styrene derivatives (e.g., o-, m-, p-methoxystyrene, o-, m-, p-tert-butoxystyrene, o-, m-, p-tert-butoxystyrene, o-, m- , p-chloromethylstyrene, etc.), vinyl esters (for example, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl acetate, etc.), vinyl ketones (for example, vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone, etc.), N-vinyl compounds (for example, N-vinyl pyrrolidone, N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, etc.), (meth) acrylic acid derivatives (for example, acrylonitrile, methacrylonitrile, acrylamide, isopropyl acrylamide, methacrylamide, etc.), vinyl halides (for example, vinyl chloride, vinylidene chloride, tetrachloroethylene, hexachloropropylene, vinyl fluoride, etc.), and other vinyl monomers, but are not limited to these. These various free radical polymerizable monomers may be used alone or in combination of two or more. In addition, these preferably have compatibility with liquid crystals.

[0208] Furthermore, as the radical polymerizable compound, a compound represented by the following formula (A) is also preferred.

[0209] [Chemistry 25]

[0210]

[0211] (In formula (A), R a and R b Each independently represents a linear alkyl group having 2 to 8 carbon atoms, and E represents a single bond, -O-, -NR c -, -S-, ester bond, amide bond. c represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms).

[0212] At least one of the radical polymerizable compounds is preferably a compound having compatibility with liquid crystals and having one polymerizable reactive group in one molecule, that is, a compound having a monofunctional radical polymerizable group.

[0213] Moreover, as the free radical polymerizable compound represented by the above formula (A), from the viewpoint of ease of synthesis, compatibility with liquid crystals, and polymerization reactivity, a compound in which E is an ester bond (a bond represented by -C(=O)-O- or -OC(=O)-) is preferred, and a compound having the following structure is specifically preferred, but there are no particular restrictions.

[0214] [Chemistry 26]

[0215]

[0216] (In formulas (A-1) and (A-2), R a and R b (each independently represents a linear alkyl group having 2 to 8 carbon atoms).

[0217] The content of the radically polymerizable compound in the liquid crystal composition is preferably 3% by mass or more, more preferably 5% by mass or more, and preferably 50% by mass or less, more preferably 20% by mass or less, based on the total mass of the liquid crystal and the radically polymerizable compound.

[0218] The Tg of the polymer obtained by polymerizing the radically polymerizable compound is preferably 100° C. or lower.

[0219] Liquid crystal generally refers to a substance that exhibits both solid and liquid properties. Representative liquid crystal phases include nematic liquid crystal and smectic liquid crystal. The liquid crystals that can be used in the present invention are not particularly limited. For example, 4-pentyl-4'-cyanobiphenyl can be cited.

[0220] Next, the liquid crystal cell into which the mixture of liquid crystal and radically polymerizable compound (liquid crystal composition) has been introduced is subjected to energy sufficient to cause the radically polymerizable compound to undergo a polymerization reaction. This can be achieved, for example, by heating or UV irradiation, at which point the radically polymerizable compound polymerizes, thereby exhibiting the desired properties. The use of UV light enables patterning of orientation, and UV irradiation is preferred for enabling polymerization reactions in a shorter time. Furthermore, when used in a twisted nematic mode, in addition to the liquid crystal composition described above, a chiral dopant may be introduced into the liquid crystal cell as needed.

[0221] The heating temperature during UV irradiation is preferably within the temperature range where the introduced liquid crystal exhibits liquid crystallinity, usually 40°C or higher, and preferably below the temperature at which the liquid crystal enters the isotropic phase.

[0222] Here, the UV irradiation wavelength is preferably selected so as to maximize the reaction quantum yield of the polymerizable compound to be reacted. The UV irradiation dose is usually 0.5 to 30 J / cm 2, preferably 1 to 10 J / cm 2 The lower the UV irradiation amount, the more it can suppress the reduction in reliability caused by damage to the components constituting the liquid crystal display, and the manufacturing rhythm can be improved by reducing the UV irradiation time, so it is preferred.

[0223] When polymerization is performed by heating alone without UV irradiation, heating is preferably performed within a temperature range of the reaction temperature of the polymerizable compound and below the decomposition temperature of the liquid crystal, specifically, 100°C to 150°C.

[0224] When energy sufficient to cause a polymerization reaction of the radical polymerizable compound is applied, a no-electric-field state in which no voltage is applied is preferred.

[0225] (Liquid Crystal Display Element)

[0226] The liquid crystal cell obtained in the above manner can be used to produce a liquid crystal display element.

[0227] For example, a reflective electrode, a transparent electrode, a λ / 4 plate, a polarizing film, a color filter layer, etc. can be provided on the liquid crystal cell according to conventional methods as needed to produce a reflective liquid crystal display element.

[0228] Furthermore, a backlight, polarizing plate, λ / 4 plate, transparent electrode, polarizing film, color filter layer, etc. can be provided on the liquid crystal cell according to conventional methods as needed to produce a transmissive liquid crystal display element.

[0229] Figure 1 1 is a schematic cross-sectional view showing an example of the liquid crystal display element of the present invention, which is an example of an IPS mode liquid crystal display element.

[0230] exist Figure 1 In the illustrated liquid crystal display element 1, a liquid crystal composition 3 is sandwiched between a comb-tooth electrode substrate 2 having a radical-generating film 2c and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-tooth electrode substrate 2 includes a substrate 2a, a plurality of linear electrodes 2b formed on the substrate 2a and arranged in a comb-tooth pattern, and a radical-generating film 2c formed on the substrate 2a to cover the linear electrodes 2b. The counter substrate 4 includes a substrate 4b and a liquid crystal alignment film 4a formed on the substrate 4b.

[0231] In this liquid crystal display element 1 , when a voltage is applied to the linear electrodes 2 b , an electric field is generated between the linear electrodes 2 b as indicated by lines of electric force L.

[0232] Figure 2 It is a schematic cross-sectional view showing another example of the liquid crystal display element of the present invention, which is an example of an FFS mode liquid crystal display element.

[0233] exist Figure 2 In the illustrated liquid crystal display element 1, a liquid crystal composition 3 is sandwiched between a comb-shaped electrode substrate 2 having a radical-generating film 2h and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-shaped electrode substrate 2 comprises a substrate 2d, a surface electrode 2e formed on the substrate 2d, an insulating film 2f formed on the surface electrode 2e, a plurality of linear electrodes 2g formed on the insulating film 2f and arranged in a comb-shaped pattern, and a radical-generating film 2h formed on the insulating film 2f so as to cover the linear electrodes 2g. The counter substrate 4 comprises a substrate 4b and a liquid crystal alignment film 4a formed on the substrate 4b.

[0234] In this liquid crystal display element 1 , when a voltage is applied to the surface electrode 2 e and the linear electrode 2 g , an electric field is generated between the surface electrode 2 e and the linear electrode 2 g as indicated by lines of electric force L.

[0235] Example

[0236] The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these Examples. The methods for labeling and evaluating the properties of the compounds used in the polymerization of the polymer and the preparation of the film-forming composition are as follows.

[0237] [Chemistry 27]

[0238]

[0239] [Chemistry 28]

[0240]

[0241] NMP: N-methyl-2-pyrrolidone,

[0242] BCS: Butyl Cellosolve

[0243] <Viscosity Measurement>

[0244] The viscosity of the polyamic acid solution at 25° C. was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample amount of 1.1 mL and a cone rotor TE-1 (1°34′, R24).

[0245] <Determination of Molecular Weight>

[0246] The molecular weight was measured using a room-temperature GPC (gel permeation chromatography) apparatus, and the number average molecular weight (Mn) and the weight average molecular weight (Mw) were calculated as polyethylene glycol and polyethylene oxide equivalents.

[0247] GPC apparatus: GPC-101 (manufactured by Showa Denko K.K.), columns: GPC KD-803 and GPC KD-805 (manufactured by Showa Denko K.K.) connected in series, column temperature: 50°C, eluent: N,N-dimethylformamide (additives: lithium bromide monohydrate (LiBr·H2O) at 30 mmol / L, anhydrous phosphoric acid (orthophosphoric acid) at 30 mmol / L, and tetrahydrofuran (THF) at 10 mL / L), flow rate: 1.0 mL / min

[0248] Standard samples for preparing the calibration curve: TSK standard polyethylene oxide (molecular weight: approximately 900,000, 150,000, 100,000, and 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight: approximately 12,000, 4,000, and 1,000) (manufactured by Polymer Laboratories).

[0249] <Measurement of Imidization Ratio>

[0250] 20 mg of polyimide powder was placed in an NMR sample tube (manufactured by Kusano Scientific Co., Ltd., NMR sampling tube standard). ), 0.53 mL of deuterated dimethyl sulfoxide (DMSO-d6, 0.05% by mass TMS (tetramethylsilane) mixture) was added, and ultrasonic waves were applied to completely dissolve the mixture. The solution was measured for 500 MHz proton NMR using a measuring device (JNW-ECA500, manufactured by JEOL DATUM Co., Ltd.).

[0251] The imidization rate was determined by the following formula using the peak integration value of a proton derived from a structure that does not change before and after imidization as a reference proton and the peak integration value of a proton derived from NH of an amide group appearing around 9.5 to 10.0 ppm.

[0252] Imidization rate (%) = (1-α·x / y) × 100

[0253] Wherein, x is the peak integral value of the protons derived from the NH of the amide group, y is the peak integral value of the reference protons, and α is the number ratio of the reference protons to the NH protons of one amide group in the case of polyamic acid (imidization rate 0%).

[0254] <Example>

[0255] DA-4, DA-5, and DA-6 are novel compounds not disclosed in the literature, and their synthesis methods are described in detail below.

[0256] The products described in the following synthesis examples were characterized by 1H-NMR analysis (analysis conditions are as follows).

[0257] Device: BRUKER ADVANCE III-500MHz

[0258] Determination solvent: DMSO-d6

[0259] Reference material: Tetramethylsilane (TMS) (for 1 H, δ 0.0ppm)

[0260] The abbreviations in the present invention have the following meanings.

[0261] THF: Tetrahydrofuran

[0262] EDC: 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide

[0263] DMAP: 4-dimethylaminopyridine

[0264] <Synthesis Example 1 Synthesis of DA-4>

[0265] [Chemistry 29]

[0266]

[0267] (First process)

[0268] Tetrahydrofuran (120 g), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (28.4 g, 126 mmol), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (28.0 g, 181 mmol), and N,N-dimethylaminopyridine (0.735 g, 6.02 mmol) were added to 4,4'-dinitro-[1,1'-biphenyl]-2,2'-dicarboxylic acid (20.0 g, 60.2 mmol) and stirred overnight at room temperature. After completion of the reaction, the mixture was extracted twice with water and chloroform, and the resulting organic phase was concentrated to yield a syrupy, brown oil. This oil was purified by column chromatography in a mixed solvent of ethyl acetate and hexane = 3 / 1 (volume ratio). Concentration of the resulting fractions yielded a transparent yellow oil, which, upon further stabilization, precipitated white crystals. The precipitated crystals were slurry-washed with a mixed solvent of ethyl acetate / hexane = 3 / 1 (volume ratio), filtered, and dried to obtain compound [0] (yield: 29.8 g, 40.0 mmol, yield 67%).

[0269] 1H-NMR(500MHz)in DMSO-d6: 8.57 (d, J=2.5Hz, 2H), 8.37 (dd, J=8.5Hz, 2.5Hz, 2H), 8.18 (d, J=9.0Hz, 4H), 7.55 (d, J=8.5Hz, 2H), 6.85 (d, J=9.0Hz, 4H), 5.631 (s, 2H), 4.39-4.35 (m, 4H), 4.02-3.99 (m, 2H), 3.96-3.94 (m, 2H), 1.40 (s, 12H).

[0270] (Second process)

[0271] Compound [0] (29.8 g, 40.0 mmol) obtained in the first step was added with tetrahydrofuran (240 g), and the mixture was purged with nitrogen. 3% platinum on carbon (water-containing) (2.38 g) was then added and further purged with nitrogen. A Tedlar bag was placed in the reaction mixture and the mixture was stirred at room temperature for approximately 17 hours. After the reaction was completed, the platinum on carbon was removed by membrane filtration, and the mixture was concentrated and dried to obtain DA-4 (yield: 27.4 g, 40.0 mmol, quant. yield).

[0272] 1 H-NMR(500MHz)in DMSO-d6: 8.20 (dd, J=7.1Hz, 1.9Hz, 4H), 6.99 (d, J=2.5Hz, 2H), 6.92 (dd, J=7.3Hz, 1.9Hz, 4H), 6.80 (d, J=8.2Hz, 2H), 6.67 (dd, J=8.2Hz, 2.5Hz, 2H), 5.64 (s, 2H), 5.24 (s, 4H), 4.22 (t, J=4.5Hz, 4H), 4.00 (br, 4H), 1.39 (s, 12H).

[0273] <Synthesis Example 2: Synthesis of DA-5>

[0274] [Chemistry 30]

[0275]

[0276] (First process)

[0277] Tetrahydrofuran (150 g) and potassium hydroxide (9.71 g, 0.173 mol) were added to 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (36.0 g, 0.161 mol), cooled in an ice bath and stirred. A solution of p-toluenesulfonyl chloride (30.0 g, 0.157 mol) in tetrahydrofuran (150 g) was added dropwise using a dropping funnel. The mixture was stirred at room temperature for 18 hours. After the reaction, the reaction solution was concentrated, ethyl acetate (300 g) was added, and the mixture was washed twice with water (250 g). The organic phase was concentrated and dried to obtain compound [1] (yield: 58.6 g, 0.155 mol, yield 98%).

[0278] 1 H-NMR(500MHz)in DMSO-d6: 8.17 (dd, J=7.0Hz, 2.0Hz, 2H), 7.80 (d, J=8.5Hz, 2H), 7.48 (d, J=8.0Hz, 2H), 6.90 (dd, J =7.0Hz, 2.0Hz, 2H), 5.65(s, 1H), 4.37-4.36(m, 2H), 4.25-4.24(m, 2H), 2.42(s, 3H), 1.38(s, 6H).

[0279] (Second process)

[0280] To 2-amino-5-nitrophenol (19.5 g, 0.127 mol) was added N,N-dimethylformamide (80 g) and potassium carbonate (21.0 g, 0.152 mol), and the mixture was heated and stirred at 80°C. A solution of compound [1] (58.5 g, 0.155 mol) in N,N-dimethylformamide (80 g) was added dropwise using a dropping funnel. After the addition was complete, the mixture was heated and stirred at 80°C for 17 hours. After the reaction was completed, the reaction solution was filtered and potassium carbonate was removed. The filtrate was added to water (1000 g) and crystallized. The crystals were filtered and dried (55.9 g of crude crystals). Acetonitrile (165 g) was added to the crude crystals, and the mixture was heated and stirred at 80°C. After the crystals were completely dissolved, the mixture was cooled to room temperature for recrystallization. The crystals were filtered and dried to obtain compound [2]. The filtrate was concentrated and recovered by the same operation until secondary crystallization to obtain compound [2] (yield: 30.0 g, 0.0832 mol, yield rate 66%).

[0281] 1H-NMR(500MHz)in DMSO-d6: 8.22 (dd, J=7.0Hz, 2.0Hz, 2H), 7.76 (dd, J=9.0Hz, 2.5Hz, 1H), 7.69 (d, J=2.5Hz, 1H), 7. 07 (d, J=9.0Hz, 2H), 6.68 (d, J=9.0Hz, 1H), 6.37 (br, 2H), 5.65 (s, 1H), 4.46 (s, 4H), 1.39 (s, 6H).

[0282] (Third Process)

[0283] Compound [2] (22.5 g, 0.0624 mol) was added to N,N-dimethylformamide (180 g), and after nitrogen substitution, 3% platinum carbon (water-containing) (0.90 g) was added and further nitrogen substitution was performed. A Tedlar hydrogen sampling bag was installed and heated and stirred at 60°C for about 3 days. After the reaction was completed, the platinum carbon was removed by a membrane filter, and the solution was concentrated and dried to obtain DA-5 crude crystals (yield: 23 g). N,N-dimethylformamide was added to the crude crystals and heated and stirred at 80°C. After complete dissolution, the solution was cooled in an ice bath for recrystallization. The resulting crystals were dried to obtain DA-5. The filtrate was concentrated and recovered by the same operation until secondary crystals were obtained to obtain DA-5 (yield: 11.5 g, 0.0348 mol, yield 56%).

[0284] 1 H-NMR(500MHz)in DMSO-d6: 8.22 (d, J=9.0Hz, 2H), 7.06 (d, J=9.0Hz, 2H), 6.40 (d, J=8.5Hz, 1H), 6.25 (d, J=2.5Hz, 1H), 6.03 (dd, J= 8.0Hz, 2.5Hz, 1H), 5.65(s, 1H), 4.41-4.39(m, 2H), 4.28(br, 2H), 4.20-4.18(m, 2H), 3.85(br, 2H), 1.39(s, 6H).

[0285] <Synthesis Example 3: Synthesis of DA-6>

[0286] [Chemistry 31]

[0287]

[0288] (First process)

[0289] Compound [2] (20.5 g, 0.0569 mol) was added with tetrahydrofuran (100 g) and pyridine (4.54 g, 0.0574 mol), cooled in an ice bath and stirred. A solution of adipoyl chloride (5.00 g, 0.0273 mol) in tetrahydrofuran (20 g) was added dropwise using a dropping funnel, and stirred at room temperature after the addition was completed. Since the stirring property deteriorated halfway through the addition, tetrahydrofuran (30 g) was added and stirred for a further 3.5 hours. After the reaction was completed, the reaction solution was added to water (1000 g) and crystallized. It was filtered and the resulting crystals were dried (43 g of crude crystals). Tetrahydrofuran (646 g) was added to the crude crystals, heated and stirred at 80°C. After the crystals were completely dissolved, they were cooled in an ice bath for recrystallization. It was filtered and the resulting crystals were dried to obtain compound [3]. The filtrate was concentrated and recovered by the same operation until secondary crystallization to obtain compound [3] (yield: 16.0 g, 0.0193 mol, yield 70%).

[0290] 1 H-NMR(500MHz)in DMSO-d6: 9.29 (s, 2H), 8.37 (d, J=9.0Hz, 2H), 8.21-8.20 (m, 4H), 7.96 (d, J=2.5Hz, 2H), 7.89 (dd, J=9.0Hz, 2.5Hz, 2H), 7 .05(d, J=8.0Hz, 4H), 5.63(s, 2H), 4.60-4.58(m, 4H), 4.52-4.50(m, 4H), 2.50-4.46(m, 4H), 1.59(s, 4H), 1.37(s, 12H).

[0291] (Second process)

[0292] Compound [3] (15.9 g, 0.0191 mol) was added to N,N-dimethylformamide (159 g), and after nitrogen substitution, 3% platinum carbon (water-containing) (1.27 g) was added and nitrogen substitution was performed. A Tedlar hydrogen sampling bag was installed and heated and stirred overnight at room temperature. The next day, crystals precipitated and the reaction stopped, so the mixture was heated to 75°C to dissolve all the crystals and stirred for another 3 hours. After the reaction was completed, the platinum carbon was removed by a membrane filter, and the filtrate was added to water (900 g) and crystallized. The crystals were filtered and dried to obtain DA-6 (yield: 14.4 g, 0.0187 mol, yield 98%).

[0293] 1H-NMR(500MHz)in DMSO-d6: 8.52 (s, 2H), 8.21 (d, J = 9.0Hz, 2H), 7.27 (d, J = 8.5Hz, 4H), 7.04 (d, J = 9.0Hz, 4H), 6.32 (d, J = 2.0Hz, 2H), 6.13- 6.11(m, 2H), 5.64(s, 2H), 5.17(br, 4H), 4.39-4.38(m, 4H), 4.23-4.21(m, 4H), 2.17(s, 4H), 1.50(s, 4H), 1.38(s, 12H).

[0294] <Synthesis of Polyamic Acid and Polyimide>

[0295] <Synthesis Example 4> Polymerization of TC-1 / DA-1, DA-2 (50) polyamic acid (PAA-1)

[0296] In a 50 mL four-necked flask equipped with a mechanical stirrer and a nitrogen inlet tube, DA-1 (1.62 g, 15.00 mmol), DA-2 (3.66 g, 15.00 mmol), and NMP (55.4 g) were weighed and dissolved under stirring. TC-1 (6.25 g, 27.90 mmol) and NMP (10.0 g) were then added and reacted at 40°C under a nitrogen atmosphere for 6 hours to obtain a polyamic acid solution (PAA-1) having a solids concentration of 15% by mass. The viscosity was 410 mPa·s, and the weight-average molecular weight was approximately 30,500.

[0297] <Synthesis Example 5> Polymerization of TC-1 / DA-2, DA-3 (50) polyamic acid (PAA-2)

[0298] In a 50 mL four-necked flask equipped with a mechanical stirrer and a nitrogen inlet tube, DA-2 (2.44 g, 10.00 mmol), DA-3 (3.30 g, 10.00 mmol), and NMP (47.2 g) were weighed and dissolved under stirring. TC-1 (4.35 g, 19.4 mmol) and NMP (10.0 g) were then added and reacted at 40°C under a nitrogen atmosphere for 6 hours to obtain a polyamic acid solution (PAA-2) having a solids concentration of 15% by mass. The viscosity was 360 mPa·s, and the weight-average molecular weight was approximately 31,900.

[0299] <Synthesis Example 6> Synthesis of TC-1 / DA-2, DA-3 (50) Soluble Polyimide (PI-1)

[0300] In a 100 mL eggplant-shaped flask equipped with a nitrogen inlet, air cooling tube, and stirrer, the polyamic acid solution (PAA-2) obtained in Synthesis Example 5 (30.0 g) was weighed. NMP (45.0 g), acetic anhydride (2.79 g: 27.3 mmol), and pyridine (1.44 g: 18.2 mmol) were added. Under a nitrogen atmosphere, the mixture was stirred at room temperature for 30 minutes and then at 50°C for 3 hours. After the reaction was completed, the reaction solution was returned to room temperature and slowly poured into methanol (300 mL) cooled to 10°C to precipitate a solid. The mixture was stirred for 10 minutes. The resulting solid was recovered by filtration and then washed twice with methanol (100 mL) for 10 minutes with stirring. The solid was then dried in a vacuum drying oven at 80°C for 6 hours to obtain the desired polyimide powder (PI-1). The imidization rate was 66%.

[0301] <Synthesis Example 7> Polymerization of TC-1 / DA-2, DA-4 (50) polyamic acid (PAA-3)

[0302] In a 50 mL four-necked flask equipped with a mechanical stirrer and a nitrogen inlet tube, DA-2 (1.71 g, 7.00 mmol), DA-4 (4.79 g, 7.00 mmol), and NMP (42.60 g) were weighed and dissolved under stirring. TC-1 (2.92 g, 13.02 mmol) and NMP (10.0 g) were then added and reacted at 40°C under a nitrogen atmosphere for 6 hours to obtain a polyamic acid solution (PAA-3). The viscosity was 440 mPa·s, and the weight-average molecular weight was approximately 32,600.

[0303] <Synthesis Example 8> Synthesis of TC-1 / DA-2, DA-4 (50) Soluble Polyimide (PI-2)

[0304] In a 100 mL eggplant-shaped flask equipped with a nitrogen inlet tube, an air cooler, and a stirrer, 30.0 g of the polyamic acid solution (PAA-3) obtained in Synthesis Example 7 above was weighed, and NMP (45.0 g), acetic anhydride (1.85 g: 18.0 mmol), and pyridine (0.95 g: 12.0 mmol) were added. Under a nitrogen atmosphere, the mixture was stirred at room temperature for 30 minutes and then at 50°C for 3 hours. After the reaction was completed, the reaction solution was returned to room temperature and slowly poured into methanol (300 mL) cooled to 10°C to precipitate a solid. The mixture was stirred for 10 minutes. The solid was recovered by filtration and then further washed with methanol (100 mL) for 10 minutes with stirring twice. The solid was then dried in a vacuum drying oven at 80°C for 6 hours to obtain the desired polyimide powder (PI-2). The imidization rate was 72%.

[0305] <Synthesis Example 9> Polymerization of TC-1 / DA-2, DA-5 (50) polyamic acid (PAA-4)

[0306] In a 50 mL four-necked flask equipped with a mechanical stirrer and a nitrogen inlet tube, DA-2 (2.44 g, 10.00 mmol), DA-5 (3.30 g, 10.00 mmol), and NMP (44.8 g) were weighed and dissolved under stirring. TC-1 (4.17 g, 18.60 mmol) and NMP (10.0 g) were then added and reacted at 40°C under a nitrogen atmosphere for 6 hours to obtain a polyamic acid solution (PAA-4) having a solids concentration of 15% by mass. The viscosity was 380 mPa·s, and the weight-average molecular weight was approximately 29,600.

[0307] <Synthesis Example 10> Synthesis of TC-1 / DA-2, DA-5 (50) Soluble Polyimide (PI-3)

[0308] In a 100 mL eggplant-shaped flask equipped with a nitrogen inlet, air cooling tube, and stirrer, the polyamic acid solution (PAA-4) obtained in Synthesis Example 9 (30.0 g) was weighed, and NMP (45.0 g), acetic anhydride (2.42 g: 23.7 mmol), and pyridine (1.25 g: 15.8 mmol) were added. Under a nitrogen atmosphere, the mixture was stirred at room temperature for 30 minutes and then at 50°C for 3 hours. After the reaction was completed, the reaction solution was returned to room temperature and slowly poured into methanol (300 mL) cooled to 10°C to precipitate a solid. The mixture was stirred for 10 minutes. The resulting solid was recovered by filtration and further washed with methanol (100 mL) for 10 minutes with stirring twice. The solid was then dried in a vacuum drying oven at 80°C for 6 hours to obtain the desired polyimide powder (SPI-3). The imidization rate was 68%.

[0309] <Synthesis Example 11> Polymerization of TC-1 / DA-2, DA-6 (50) Polyamic Acid (PAA-5) In a 50 mL four-necked flask equipped with a mechanical stirrer and a nitrogen inlet tube, DA-2 (1.22 g: 5.00 mmol), DA-6 (3.85 g: 5.00 mmol), and NMP (30.8 g) were weighed and stirred for a period of time to dissolve. TC-1 (2.13 g: 9.50 mmol) and NMP (10.0 g) were then added and reacted at 40°C under a nitrogen atmosphere for 6 hours to obtain a polyamic acid solution (PAA-5) having a solid content concentration of 15% by mass. The viscosity was 430 mPa·s, and the weight-average molecular weight was approximately 33,400.

[0310] <Synthesis Example 12> Synthesis of TC-1 / DA-2, DA-6 (50) Soluble Polyimide (PI-4)

[0311] In a 100 mL eggplant-shaped flask equipped with a nitrogen inlet, air cooler, and stirrer, the polyamic acid solution (PAA-5) obtained in Synthesis Example 11 (30.0 g) was weighed. NMP (45.0 g), acetic anhydride (1.94 g: 18.9 mmol), and pyridine (1.00 g: 12.6 mmol) were added. Under a nitrogen atmosphere, the mixture was stirred at room temperature for 30 minutes and then at 50°C for 3 hours. After the reaction was completed, the reaction solution was returned to room temperature and slowly poured into methanol (300 mL) cooled to 10°C to precipitate a solid. The mixture was stirred for 10 minutes. The resulting solid was recovered by filtration and then further washed with methanol (100 mL) for 10 minutes with stirring twice. The solid was then dried in a vacuum drying oven at 80°C for 6 hours to obtain the desired polyimide powder (SPI-4). The imidization rate was 71%.

[0312] (Examples 1 to 5)

[0313] Preparation of liquid crystal alignment agents AL-1 to AL-5

[0314] The polyamic acid solution (PAA-1) (10.0 g) obtained in Synthesis Example 4 was weighed into a 50 mL Erlenmeyer flask equipped with a stirrer, and NMP (7.5 g) and BCS (7.5 g) were added. The mixture was stirred at room temperature for 30 minutes to prepare a liquid crystal aligning agent AL-1.

[0315] Radical-generating film-forming compositions AL-2 to AL-5 were obtained by the same preparation as for AL-1 except that PAA-2 to PAA-5 were used instead of PAA-1.

[0316] (Examples 6 to 9) Preparation of AL-6 to AL-9

[0317] In a two-necked eggplant flask equipped with a nitrogen inlet tube and a stirrer, the polyimide powder (PI-1) (2.0 g) obtained in Synthesis Example 6 was weighed, NMP (18.0 g) was added, and the mixture was stirred at 40°C for 6 hours to dissolve. After confirming complete dissolution, NMP (3.3 g) and BCS (10.0 g) were added, and the mixture was stirred at room temperature for 30 minutes to prepare a radical-generating film-forming composition AL-6.

[0318] Radical-generating film-forming compositions AL-7 to AL-9 were obtained by preparing the same method as AL-6 except that PI-2 to PI-4 were used instead of PI-1.

[0319] <Fabrication of Liquid Crystal Cell>

[0320] The method for producing a liquid crystal cell for evaluating the liquid crystal orientation is shown below.

[0321] First, prepare a substrate with electrodes. The substrate is a glass substrate with a size of 30mm×35mm and a thickness of 0.7mm. An IZO electrode with a full-surface (Japanese: ベタ) pattern constituting a counter electrode is formed on the substrate as the first layer. A SiN (silicon nitride) film formed by CVD (chemical vapor deposition) is formed as the second layer on the counter electrode of the first layer. The second layer of SiN film has a thickness of 500nm and functions as an interlayer insulating film. A comb-shaped pixel electrode formed by patterning the IZO film is arranged on the second layer of SiN film as the third layer to form two pixels, the first pixel and the second pixel. The size of each pixel is 10mm long and about 5mm wide. At this time, the counter electrode of the first layer and the pixel electrode of the third layer are electrically insulated by the action of the second layer of SiN film.

[0322] The pixel electrode of the third layer has a comb-tooth shape consisting of multiple electrode elements with a width of 3 μm, which are bent at an internal angle of 160° at the central part and arranged in parallel at intervals of 6 μm. A pixel has a first area and a second area with the line connecting the bent parts of the multiple electrode elements as the boundary.

[0323] If the first area and the second area of each pixel are compared, it can be found that the formation directions of the electrode elements of the pixel electrodes constituting them are different. That is, with the orientation direction of the liquid crystal alignment film described later as a reference, the electrode elements of the pixel electrode in the first area of the pixel are formed in a manner to become an angle of +80° (clockwise), and the electrode elements of the pixel electrode in the second area of the pixel are formed in a manner to become an angle of -80° (counterclockwise). That is, in the first area and the second area of each pixel, the directions of the rotational movement (in-plane switching) of the liquid crystal in the substrate surface induced by applying a voltage between the pixel electrode and the counter electrode are opposite to each other. Hereinafter referred to as the FFS substrate (first substrate).

[0324] Then, the radical-generating film-forming compositions AL-2 to AL-9 or the liquid crystal alignment agent AL-1 obtained by the above method were filtered through a filter with a pore size of 1.0 μm and then applied by spin coating to the prepared first substrate and a glass substrate (hereinafter referred to as the second substrate) having an ITO film formed on the back surface and a columnar spacer with a height of 4.0 μm as the counter substrate. Then, after drying on a hot plate at 80°C for 80 minutes, the film was calcined at 230°C for 20 minutes to obtain a coating film with a thickness of 100 nm. The polyimide film on the first substrate was oriented in the direction along the comb teeth, and the polyimide film on the second substrate side was oriented in the direction perpendicular to the comb teeth electrode. In addition, during the orientation treatment, a UV exposure device manufactured by Ushio Electric Co., Ltd. was used to expose linearly polarized UV light with an extinction ratio of approximately 26:1 at a wavelength of 254 nm at a rate of 50 to 500 mJ / cm 2 Polarized UV was irradiated with a dose between the two, and the samples were heated at 230°C for 30 minutes. The conditions for the best orientation quality were used for comparison.

[0325] Thereafter, using the above two substrates, for the display elements used as the subject of the embodiment, a display element was used in which AL-1 was provided on the first substrate side and a free radical generating film was provided on the second substrate side; for the display elements used as the comparison objects, a display element was used in which AL-1 was used for both substrates, and a display element was used in which a free radical generating film AL-1 was used on the first substrate side and AL-2 or AL-6 was used on the second substrate side. They were combined in such a way that their respective orientation directions were parallel (antiparallel in the case of friction), the liquid crystal injection port was retained and the surrounding area was sealed to produce an empty cell with a cell gap of approximately 4μm. Into this empty cell, liquid crystal (made by adding 3% by mass of the additive IC6 to MLC-3019 manufactured by Merck) was vacuum injected at room temperature, and the injection port was sealed to produce a liquid crystal cell with antiparallel orientation. The resulting liquid crystal cell constituted an FFS mode liquid crystal display element. Thereafter, the obtained liquid crystal cell was heat-treated at 120° C. for 10 minutes and irradiated with UV (UV lamp: FLR40SUV32 / A-1) for 30 minutes using a UV-FL irradiation apparatus manufactured by TOSHIBA LIGHTING & TECHNOLOGY Co., Ltd. with no voltage applied, to obtain a liquid crystal display element.

[0326] <Evaluation of Liquid Crystal Orientation>

[0327] Using a polarizing microscope, with the polarizing plate set as a crossed Nicol prism, the liquid crystal cell was fixed at its minimum brightness. From this position, the liquid crystal cell was rotated 1° to observe the alignment of the liquid crystal. If no unevenness or surface roughness was observed, or only very slight, the result was rated "good." If such unevenness or surface roughness was clearly observed, the result was rated "poor."

[0328] In addition, a photodiode was mounted on the same polarizing microscope and connected to an electrometer via a current-voltage conversion amplifier. The voltage under the condition where the brightness was minimum was measured under crossed Nicol prisms to measure the black brightness.

[0329] <VT curve measurement and evaluation of driving threshold voltage and maximum brightness voltage>

[0330] A white LED backlight and a luminance meter were set up with their optical axes aligned. A liquid crystal cell (liquid crystal display element) with a polarizer attached was placed between them to minimize brightness. Voltage was applied in increments of 1V up to 8V, and the brightness at each voltage was measured to measure the VT curve. The resulting VT curve was used to estimate the driving threshold voltage and the voltage at maximum brightness. Furthermore, the maximum transmittance was estimated by comparing the maximum transmitted brightness in the VT curve, assuming the luminance transmitted through the liquid crystal cell with no voltage applied when using a parallel Nicol prism to 100%.

[0331] <Measurement of response time (Ton, Toff)>

[0332] Using the device used for measuring the VT curve, a luminance meter was connected to an oscilloscope to measure the response speed (Ton) when a voltage reaching maximum luminance was applied and the response speed (Toff) when the voltage returned to 0 V.

[0333] <Contents of polymer>

[0334] [Table 1]

[0335]

[0336] <Contents of Liquid Crystal Alignment Agent or Radical-Generation Film-Forming Composition>

[0337] [Table 2]

[0338]

[0339] (Examples 10 to 16 and Comparative Examples 1 to 4)

[0340] <Example Liquid Crystal Cell Contents>

[0341] The composition of the liquid crystal cell is shown in Table 3 below.

[0342] [Table 3]

[0343]

[0344] <Results>

[0345] [Table 4]

[0346]

[0347] It is shown that the radical-generating films using the diamine compounds DA-4 to DA-6 of the present invention have better photo-alignment properties and tend to have higher black brightness than the radical-generating film using the zigzag structure DA-3. Furthermore, the liquid crystal cells using any of the radical-generating films exhibit lower Vmax and improved maximum transmittance compared to the strongly anchored cell of Comparative Example 1. The liquid crystal cells using DA-4 to DA-6 achieve even greater improvements than the liquid crystal cell using DA-3. Meanwhile, the liquid crystal cell of Comparative Example 4, which did not undergo photo-alignment treatment, exhibited a higher Vmax, lower voltage, and significantly improved maximum transmittance. However, its response time was significantly worse than that of Comparative Example 1. In contrast, the liquid crystal cells using DA-4 to DA-6, which underwent photo-alignment treatment, exhibited less delay in response time.

[0348] Industrial applicability

[0349] By using the liquid crystal alignment agent of the present invention, a horizontal electric field liquid crystal display element can be provided that can achieve an excellent black display, high backlight transmittance, and high response speed. In addition, the liquid crystal display element obtained by the method of the present invention can be used as a liquid crystal display element using a horizontal electric field drive mode.

[0350] Description of Reference Numerals

[0351] 1 Liquid crystal display element

[0352] 2 Comb-tooth electrode substrate

[0353] 2a Substrate

[0354] 2b Linear electrode

[0355] 2c Free radical generating membrane

[0356] 2D substrate

[0357] 2e surface electrode

[0358] 2f insulating film

[0359] 2g wire electrode

[0360] 2h free radical generation film

[0361] 3 Liquid crystal composition

[0362] 4 Opposite substrate

[0363] 4a Liquid crystal alignment film

[0364] 4b Base material

Claims

1. A liquid crystal aligning agent comprising a polymer having a structural unit represented by the following formula (1) in its main chain: ， In formula (1), A represents an organic group that initiates free radical polymerization, and the organic group that initiates free radical polymerization is a group represented by the following formula (3): ， In formula (3), the dotted line represents the bond connecting the benzene ring, R 6 represents a single bond, -CH2-, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH2O-, -N(CH3)-, -CON(CH3)-, or -N(CH3)CO-, R 7 represents a single bond, or an unsubstituted or fluorine-substituted alkylene group having 1 to 20 carbon atoms, wherein one or more of any -CH2- or -CF2- in the alkylene group are independently substituted by or are not substituted by a group selected from -CH=CH-, a divalent carbocycle, and a divalent heterocycle, and further, under the condition that any of the following groups, i.e., -O-, -COO-, -OCO-, -NHCO-, -CONH-, or -NH-, are not adjacent to each other, R 8 represents an organic group that initiates radical polymerization represented by formula [Y], ， In formula [Y], Represents R 7 The bonding site of S 3 represents a single bond, -O-, -S-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH2O-, -N(CH3)-, -CON(CH3)-, or -N(CH3)CO-; Ar represents an aromatic hydrocarbon group selected from phenylene, naphthylene, and biphenylene, which may have an organic group and / or a halogen atom as a substituent; R 9 and R 10 Each independently represents an alkyl group, an alkoxy group, a benzyl group, or a phenethyl group having 1 to 10 carbon atoms. In the case of an alkyl group or an alkoxy group, R 9 and R 10 Ring formation or no ring formation; Q is a hydroxyl group.

2. The liquid crystal aligning agent according to claim 1, wherein The polymer is at least one polymer selected from a polyimide precursor, polyimide, polyurea, and polyamide obtained using a diamine component, and the diamine component includes a diamine having an organic group that initiates radical polymerization.

3. The liquid crystal aligning agent according to claim 2, wherein The diamine containing an organic group that initiates radical polymerization is a diamine represented by the following formula (2), ， In formula (2), A 1 and A 2 Respectively represent a hydrogen atom or the organic group that initiates free radical polymerization, wherein A 1 and A 2 At least one of represents the organic group that initiates free radical polymerization, E represents a single bond, -O-, -C(CH3)2-, -NH-, -CO-, -NHCO-, -COO-, -(CH2) m -, -SO2-, or a divalent organic group containing any combination thereof, m represents an integer of 1 to 8, p represents an integer from 0 to 2; when p is 2, multiple A 2 have the above definitions independently; in addition, when p is 0, A 1 Contains organic groups that initiate free radical polymerization. A radical-generating film obtained using the liquid crystal aligning agent according to claim 1 .

5. A method for manufacturing a horizontal electric field liquid crystal unit, comprising: a step of preparing a first substrate having the radical generating film according to claim 4 and a second substrate having a liquid crystal alignment film; a step of forming a unit in such a manner that the radical generating film on the second substrate faces the first substrate; as well as a step of filling a liquid crystal composition containing a liquid crystal and a radical polymerizable compound between the first substrate and the second substrate; One of the first substrate and the second substrate is a comb-teeth electrode substrate, and the other is a counter substrate.

6. The method for manufacturing a horizontal electric field liquid crystal unit according to claim 5, wherein: The first substrate is a substrate covered with a liquid crystal alignment film having uniaxial alignment properties.

7. The method for manufacturing a horizontal electric field liquid crystal unit according to claim 6, wherein: The liquid crystal alignment film having uniaxial alignment properties is a liquid crystal alignment film for horizontal alignment.

8. The method for manufacturing a horizontal electric field liquid crystal cell according to any one of claims 5 to 7, wherein: The comb-tooth electrode substrate is an IPS substrate or an FFS substrate.

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