Compound

Abstract

To provide a liquid crystal-aligning agent employing an additive with a novel structure capable of enhancing functions of the liquid crystal-aligning agent.SOLUTION: The liquid crystal-aligning agent has a compound represented by the formula (1), where Z represents formula (Z-1) or (Z-2), and the symbol * represents bonding to X1.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a compound. [Background technology]

[0002] Liquid crystal display elements are known as lightweight, thin, and low-power display devices. In recent years, they have made remarkable progress in high-definition liquid crystal display elements for mobile phones and tablet devices, which have been rapidly expanding their market share, and high display quality is now required. In liquid crystal display elements, the liquid crystal alignment film plays the role of aligning liquid crystals in a certain direction. Liquid crystal alignment films are produced by applying a liquid crystal alignment agent, the main component of which is a solution of a polymer such as polyimide precursors, such as polyamic acid (also called polyamide acid), polyamic acid ester, or soluble polyimide, to a substrate and baking it to form a film. For the purpose of improving the display characteristics of liquid crystal display elements and increasing production efficiency during manufacturing, liquid crystal alignment agents are being developed by methods such as modifying the structure of the above-mentioned polymers, blending polymers with different characteristics, and using additives.

[0003] There are various purposes for adding additives to liquid crystal alignment agents, such as imparting a pretilt angle to liquid crystals (see, for example, Patent Document 1) and improving the mechanical strength of the resulting liquid crystal alignment film by a crosslinking reaction of the additive (see, for example, Patent Document 2), and additives having structures and properties according to the purposes are used. On the other hand, the use of additives also brings about issues such as a decrease in liquid crystal alignment and contamination of the liquid crystal, and new additives that can resolve these trade-offs are required. Furthermore, with the rapid decline in the price of liquid crystal display devices, there is a demand for improvements in ease of synthesis and cost. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] WO2010 / 035719 [Patent Document 2] WO2010 / 074269 Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved by the present invention is to provide a liquid crystal aligning agent using an additive having a novel structure that can enhance the functionality of the liquid crystal aligning agent. [Means for solving the problem]

[0006] Thus, the present invention is based on the above findings and has the following gist. A liquid crystal aligning agent comprising at least one polymer selected from a polyimide precursor and an imidized product thereof, that is, a polyimide, and a compound represented by the following formula (1) (hereinafter also referred to as a specific compound).

[0007] [ka]

[0008] [ka]

[0009] In the formula, X 1 and X 2 are each independently a single bond, -(CH2) a -(a is an integer of 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -COO-, -OCO- or -((CH2) a1 -A1) m1 In this, a1's each independently represent an integer of 1 to 15, a1's each independently represent an oxygen atom or -COO-, and m1 is 1 to 2.

[0010] G 1 and G 2each independently represents a divalent cyclic group selected from a divalent aromatic group having 6 to 12 carbon atoms or a divalent alicyclic group having 3 to 8 carbon atoms. Any hydrogen atom on the cyclic group may be substituted with an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxy group having 1 to 3 carbon atoms, or a fluorine atom. each independently represents an integer of 0 to 3, and the sum of m and n is 1 to 4. q is an integer of 1 or 2.

[0011] R 1 represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms. 1 Any hydrogen in the formula may be replaced by fluorine.

[0012] Z represents the above formula (Z-1) or (Z-2), when Z is (Z-1), q is 1, and when Z is (Z-2), q is 2, Y1 and Y2 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxyalkyl group having 1 to 4 carbon atoms, * represents X 1 Represents a bond with. Effect of the Invention

[0013] By using the liquid crystal aligning agent of the present invention, it is possible to impart and control a pretilt angle to liquid crystal, and further, it is possible to suppress the decrease in alignment, which is a disadvantage of using an additive, and it is possible to obtain a liquid crystal display element with high display quality.

[0014] The mechanism by which the liquid crystal aligning agent of the present invention exerts the above-mentioned effects is not clear, but is generally believed to be as follows.

[0015] Conventional additives are low molecular weight, so they tend to be unevenly distributed on the surface of the liquid crystal alignment film during the preparation of the film. In addition, these additives do not have the ability to align liquid crystals or impart a pretilt, so if they are present on the surface, the side chain structure of the polymer may inhibit the alignment of liquid crystals or the impartation of a pretilt angle.

[0016] In contrast, the specific compound of the present invention has a side chain structure that imparts a pretilt angle to the liquid crystal. As a result, even if the specific compound is unevenly distributed on the surface layer of the liquid crystal alignment film during preparation of the liquid crystal alignment film, it does not hinder the vertical alignment of the liquid crystal, but rather acts in a direction that supports the pretilt angle imparting ability of the side chain structure of the polymer. When a polymer without a side chain structure is used in the liquid crystal alignment film, the specific compound itself imparts a pretilt angle to the liquid crystal.

[0017] Furthermore, since the specific compound of the present invention also has a crosslinkable structure, the hardness of the film is increased, and as a result, a liquid crystal display device with high display quality can be obtained. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The liquid crystal aligning agent of the present invention comprises at least one polymer selected from polyimide precursors and polyimides which are imidized products thereof, and the specific compound of the above formula (1). Each of the constituent elements will be described in detail below. <Specific compound> The specific compound of the present invention is represented by the following formula (1).

[0019] [ka]

[0020] [ka]

[0021] In the formula, X 1 and X 2 are each independently a single bond, -(CH2) a -(a is an integer of 1 to 15), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -COO-, -OCO- or -((CH2) a1 -A1) m1In this, each of the multiple a1's is independently an integer of 1 to 15, each of the multiple A1's is independently an oxygen atom or -COO-, and m1 is 1 to 2. From the viewpoint of availability of raw materials and ease of synthesis, each of X1 and X2 is independently a single bond, -(CH2) a -(a is an integer of 1 to 15), -O-, -CH2O- or -COO- is preferred, and a single bond, -(CH2) a -(a is an integer of 1 to 10), -O-, -CH2O- or -COO- is more preferred.

[0022] G 1 and G 2 each independently represents a divalent cyclic group selected from a divalent aromatic group having 6 to 12 carbon atoms or a divalent alicyclic group having 3 to 8 carbon atoms. Any hydrogen atom on the cyclic group may be substituted with an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxy group having 1 to 3 carbon atoms, or a fluorine atom. each independently represents an integer of 0 to 3, and the sum of m and n is 1 to 4. q is an integer of 1 or 2.

[0023] R 1 represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms. 1 Any hydrogen atom forming the group may be substituted with fluorine. Examples of the divalent aromatic group having 6 to 12 carbon atoms include phenylene, biphenylene, and naphthalene. Examples of the divalent alicyclic group having 3 to 8 carbon atoms include cyclopropylene and cyclohexylene. Z represents the above formula (Z-1) or (Z-2), when Z is (Z-1), q is 1, and when Z is (Z-2), q is 2, Y1 and Y2 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxyalkyl group having 1 to 4 carbon atoms, * represents X 1 Represents a bond with. Therefore, preferred specific examples of the above formula (1) include, but are not limited to, the following formulae (S1-x1) to (S1-x8). More preferred examples include the following formulae (S1-x1), (S1-x2), (S1-x4), and (S1-x5) when Z is (Z-1), and the following formulae (S1-x1) to (S1-x5) when Z is (Z-2).

[0024] [ka]

[0025] In the formula, R 1 is an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms; p is a single bond, -(CH2) a A1 represents an oxygen atom or -COO-* (wherein the bond marked with "*" is (CH2)), -CONH-, -NHCO-, -CON(CH3)-, -NH-, -O-, -CHO-, -CHOCO-, -COO-, or -OCO-; A1 represents an oxygen atom or -COO-* (wherein the bond marked with "*" is (CH2) a2 A2 is an oxygen atom or *-COO- (where the bond marked with "*" is (CH2) a2 wherein a1 and a3 each independently represent an integer of 0 or 1, a2 represents an integer of 1 to 10, and Cy represents a 1,4-cyclohexylene group or a 1,4-phenylene group.

[0026] Z represents the above formula (Z-1) or (Z-2), and when Z is (Z-1), q is 1, and when Z is (Z-2), q is 2. Y1 and Y2 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxyalkyl group having 1 to 4 carbon atoms. A hydrogen atom or an alkyl group having 1 to 2 carbon atoms is preferable. * represents X 1 Represents a bond with.

[0027] Here, the specific compound represented by the formula (1), in which Z is the above formula (Z-1), the sum of m and n is 3, and [1] Y1 and Y2 are hydrogen atoms, is specific compound (A); the specific compound represented by the formula (1), in which [2] Y1 is an alkyl group having 1 to 4 carbon atoms or an alkoxyalkyl group having 1 to 4 carbon atoms, and Y2 is a hydrogen atom, is specific compound (D); and the specific compound represented by the formula (1), in which [3] Y1 and Y2 are an alkyl group having 1 to 4 carbon atoms, or an alkoxyalkyl group having 1 to 4 carbon atoms, is specific compound (F). In addition, the specific compound represented by the formula (1) where Z is the above formula (Z-1), the sum of m and n is 2, and [1] Y1 and Y2 are hydrogen atoms is the specific compound (B), the specific compound represented by the formula (1) where [2] Y1 is an alkyl group having 1 to 4 carbon atoms or an alkoxyalkyl group having 1 to 4 carbon atoms and Y2 is a hydrogen atom is the specific compound (E), and the specific compound represented by the formula (1) where [3] Y1 and Y2 are an alkyl group having 1 to 4 carbon atoms or an alkoxyalkyl group having 1 to 4 carbon atoms is the specific compound (G). Furthermore, the specific compound represented by the formula (1) where Z is the above formula (Z-2) is the specific compound (C). Specific compounds of the specific compounds (A) to (G) include the following.

[0028] [ka]

[0029] [ka]

[0030] [ka]

[0031] [ka]

[0032] [ka]

[0033] [ka]

[0034] [ka]

[0035] <Synthesis of specific compounds> (Method of synthesizing specific compound [A] and specific compound [B]) The method for obtaining the above-mentioned specific compounds [A] and [B] will be described below. The method for synthesizing the specific compounds of the present invention is not particularly limited, but the specific compound [A] can be obtained by reacting a phenol [AI] with formaldehyde in the presence of a base. Similarly, the specific compound [B] can be obtained by reacting a phenol [BI] with formaldehyde in the presence of a base.

[0036] [ka] In the formula, R 1 is the same as the above formula (1).

[0037] As the base, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, an alkali metal carbonate such as sodium carbonate, potassium carbonate or cesium carbonate, or the like can be used. Sources of formaldehyde include aqueous formaldehyde solutions (formalin), paraformaldehyde, and the like. Examples of reaction solvents that can be used include pure water, alcohol solvents (methanol, ethanol, 2-propanol, tert-butyl alcohol, etc.), ethers (Et2O, i-Pr2O, TBME, CPME, THF, dioxane, etc.), and aprotic polar organic solvents (DMF, DMSO, DMAc, NMP, etc.). These solvents can be appropriately selected in consideration of the ease of reaction, and can be used alone or in combination of two or more. The reaction temperature is not particularly limited, but is within the range of -20°C to the boiling point of the solvent used, preferably -10 to 100°C. The specific compound [A] or [B] obtained by the above reaction can be purified by recrystallization or column chromatography using silica gel or the like.

[0038] (Method of synthesizing specific compound [C]) The method for obtaining the specific compound [C] described above will be described below. The method for synthesizing the specific compound of the present invention is not particularly limited, but for example, the specific compound [C] can be obtained as shown in the following formula.

[0039] [ka]

[0040] In the formula, R 1 The definition of Y1 is the same as in formula (1). X represents Cl, Br or I, and LG-Cl represents methanesulfonyl chloride, ethanesulfonyl chloride or p-toluenesulfonyl chloride (LG represents a leaving group, and represents a methanesulfonyl group, an ethanesulfonyl group or a p-toluenesulfonyl group). n1 represents 0 to 7.

[0041] (Method of synthesis of compound [CI]) Compound [CI] can be obtained by reacting compound [BI] with a hydroxyl-containing organic halide in the presence of a base. Examples of hydroxy group-containing organic halides include 2-chloroethanol, 2-bromoethanol, 2-iodoethanol, 3-chloro-1-propanol, 3-bromo-1-propanol, 4-chloro-1-butanol, 4-bromo-1-butanol, 5-chloro-1-pentanol, 5-bromo-1-pentanol, 6-chloro-1-hexanol, and 6-bromo-1-hexanol. As the base, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, an alkali metal carbonate such as sodium carbonate, potassium carbonate or cesium carbonate, or the like can be used. The reaction solvent is preferably acetone, acetonitrile, aprotic polar organic solvent (DMF, DMSO, DMAc, NMP, etc.), etc. These solvents can be appropriately selected in consideration of the ease of reaction, etc., and can be used alone or in combination of two or more kinds. This reaction can be accelerated by adding a catalyst, and sodium iodide or potassium iodide can be used as the catalyst. The reaction temperature is not particularly limited, but is within the range of from 0°C to the boiling point of the solvent used, preferably 20 to 140°C.

[0042] The compound [CI] obtained by the above reaction can be purified by recrystallization or column chromatography on silica gel or the like.

[0043] (Method for synthesizing compound [C-II]) Compound [C-II] can be obtained by reacting compound [CI] with methanesulfonyl chloride, ethanesulfonyl chloride, or p-toluenesulfonyl chloride in the presence of a base. Examples of the base that can be used include inorganic bases such as sodium carbonate, potassium carbonate, lithium carbonate, and cesium carbonate; and amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, tripropylamine, isopropylamine, diisopropylamine, triisopropylamine, butylamine, dibutylamine, tributylamine, diisopropylethylamine, pyridine, imidazole, quinoline, collidine, pyrrolidine, piperidine, morpholine, and N-methylmorpholine. Any reaction solvent can be used as long as it is stable, inert, and does not interfere with the reaction under the reaction conditions. Examples of reaction solvents that can be used include aprotic polar organic solvents (DMF (dimethylformamide), DMSO (dimethylsulfoxide), DMAc (dimethylacetamide), NMP (N-methylpyrrolidone), etc.), ethers (Et2O, i-Pr2O, TBME, CPME, THF, dioxane, etc.), aliphatic hydrocarbons (pentane, hexane, heptane, petroleum ether, etc.), aromatic hydrocarbons (benzene, toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene, nitrobenzene, tetralin, etc.), halogenated hydrocarbons (chloroform, dichloromethane, carbon tetrachloride, dichloroethane, etc.), lower fatty acid esters (methyl acetate, ethyl acetate, butyl acetate, methyl propionate, etc.), and nitriles (acetonitrile, propionitrile, butyronitrile, etc.). These solvents can be appropriately selected in consideration of the ease of reaction, etc., and can be used alone or in combination of two or more. In some cases, the above solvents can be used as water-free solvents by using an appropriate dehydrating agent or drying agent.

[0044] The reaction temperature can be selected from the range of preferably -20°C or higher up to the boiling point of the reaction solvent used, and is preferably -10 to 100°C.

[0045] The compound [C-II] obtained by the above reaction can be purified by recrystallization or column chromatography on silica gel or the like.

[0046] (Method of synthesizing compound [C]) The specific compound [C] can be obtained by reacting the compound [C-II] with the compound [C-III] in the presence of a base. Specific examples of the compound [C-III] include [C-III-1] to [C-III-3].

[0047] [ka]

[0048] The base, catalyst, and solvent used are the same as those used in the synthesis of compound [CI].

[0049] (Method of synthesizing specific compound [D] and specific compound [E]) The method for obtaining the above-mentioned specific compounds [D] and [E] will be described below. The method for synthesizing the specific compounds of the present invention is not particularly limited, but the specific compound [D] can be obtained by reacting the specific compound [A] in an alcohol solvent in the presence of an acid catalyst. Similarly, the specific compound [E] can be obtained by reacting the specific compound [B] in an alcohol solvent in the presence of an acid catalyst.

[0050] [ka] In the formula, R 1 is defined as the same as in the above formula (1). Y1 represents an alkyl group having 1 to 4 carbon atoms or an alkoxyalkyl group having 1 to 4 carbon atoms.

[0051] The acid catalyst used here may be, for example, an acidic compound such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonic acid, salicylic acid, 5-sulfosalicylic acid, 4-phenolsulfonic acid, camphorsulfonic acid, 4-chlorobenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, hydroxybenzoic acid, or naphthalenecarboxylic acid. However, in order not to leave unreacted acid in the reaction system, a catalytic ion exchange resin may be used. For example, a sulfonic acid type strong acid ion exchange resin may be used as the catalytic ion exchange resin.

[0052] The alcohol solvent acts as both a reactant and a solvent, and examples of the alcohol solvent that can be used include methanol, ethanol, 1-propanol, isopropyl alcohol, 1-butanol, 2-methyl-1-propanol, 2-methyl-1-propanol, 2-methoxyethanol, 1-methoxy-2-propanol, and 2-ethoxyethanol.

[0053] The reaction temperature can be selected from the range of from 20°C or higher to the boiling point of the reaction solvent used, and is preferably 30 to 150°C.

[0054] The specific compound [D] and the specific compound [E] obtained by the above reaction can be purified by recrystallization or column chromatography using silica gel or the like.

[0055] (Method of synthesizing specific compound [F] and specific compound [G]) The method for obtaining the above-mentioned specific compounds [F] and [G] will be described below. The method for synthesizing the specific compounds of the present invention is not particularly limited, but the specific compound [F] can be obtained by reacting an organic halide with a specific compound [D] in the presence of a base. Similarly, the specific compound [G] can be obtained by reacting an organic halide with a specific compound [E] in the presence of a base.

[0056] [ka] In the formula, R 1 are defined as in formula (1) above. Y1 and Y2 each represent an alkyl group having 1 to 4 carbon atoms or an alkoxyalkyl group having 1 to 4 carbon atoms. X represents Cl, Br, or I.

[0057] Examples of the organic halide include iodomethane, iodoethane, 1-chloropropane, 1-bromopropane, 1-iodopropane, 1-chlorobutane, 1-bromobutane, 1-iodobutane, 2-chloroethyl methyl ether, and 2-chloroethyl ethyl ether. The base, catalyst, and solvent used are the same as those used in the synthesis of compound [CI].

[0058] <Tetracarboxylic acid derivatives> The polyimide precursor contained in the liquid crystal aligning agent of the present invention is obtained by reacting a tetracarboxylic acid derivative with a diamine, and the polyimide is obtained by imidizing the polyimide precursor. Specific examples of the materials used and the production method are described in detail below.

[0059] Examples of the tetracarboxylic acid derivatives used in the production of the polyimide precursor include not only tetracarboxylic acid dianhydrides but also their derivatives, such as tetracarboxylic acids, tetracarboxylic acid dihalide compounds, tetracarboxylic acid dialkyl esters, and tetracarboxylic acid dialkyl ester dihalides.

[0060] Of the tetracarboxylic dianhydrides and derivatives thereof, those represented by the following formula (3) are preferred.

[0061] [ka]

[0062] In the formula (3), the structure of X1 is not particularly limited as long as it is a tetravalent organic group. More preferred specific examples include (X1-1) to (X1-10) and (X1-27) to (X1-43).

[0063] [ka]

[0064] [ka]

[0065] [ka]

[0066] [ka]

[0067] [ka]

[0068] [ka]

[0069] In formulae (X1-1) to (X1-4), R 23 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, or a phenyl group. 23 is preferably a hydrogen atom, a halogen atom, a methyl group, or an ethyl group, and more preferably a hydrogen atom or a methyl group.

[0070] Specific examples of formula (X1-1) include the following formulae (X1-1-1) to (X1-1-6): In terms of liquid crystal alignment properties, (X1-1-1) is particularly preferred.

[0071] [ka]

[0072] <Diamine> The diamine used in the production of the polyimide precursor is represented by the following formula (2).

[0073] [ka]

[0074] In the above formula (2), A1 and A2 each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an alkynyl group having 2 to 5 carbon atoms.

[0075] The structure of Y1 is not particularly limited. Preferred structures include the following (Y-1) to (Y-181).

[0076] [ka]

[0077] [ka]

[0078] [ka]

[0079] [ka]

[0080] [ka]

[0081] [ka]

[0082] [ka]

[0083]

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[0084]

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[0085]

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[0086]

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[0087]

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[0088]

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[0089]

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[0090]

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[0091]

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[0092]

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[0093] [ka]

[0094] [ka]

[0095] In the above formula, Me represents a methyl group, R 1 represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms.

[0096] [ka]

[0097] Among them, the structure of Y1 is (Y-7), (Y-8), (Y-16), (Y-17), (Y-18), (Y-20), (Y-21), (Y-22), (Y-28), (Y-35), (Y-38), (Y-43), (Y-48), (Y-64), (Y- 66), (Y-71), (Y-72), (Y-76), (Y-77), (Y-80), (Y-81), (Y-82), (Y-83), (Y-155), (Y-158), (Y-159), (Y-160), (Y-161), (Y-167), (Y-168) , (Y-169), (Y-170), (Y-172), and (Y-174) are preferred, particularly (Y-7), (Y-8), (Y-16), (Y-17), (Y-18), (Y-21), (Y-22), (Y-28), (Y-38), (Y-64), and (Y-66). ), (Y-72), (Y-76), (Y-81), (Y-155), (Y-158), (Y-159), (Y-160), (Y-161) (Y-167), (Y-168), (Y-169), (Y-170), (Y-172), and (Y-174) are preferred.

[0098] <Polyamic acid> The polyamic acid, which is a polyimide precursor used in the present invention, can be produced by the following method. Specifically, it can be synthesized by reacting a tetracarboxylic dianhydride with a diamine in the presence of an organic solvent at -20°C to 150°C, preferably 0°C to 50°C, for 30 minutes to 24 hours, preferably 1 to 12 hours.

[0099] The organic solvent used in the above reaction is preferably N,N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone in terms of the solubility of the monomer and polymer, and these may be used alone or in combination of two or more. The concentration of the polymer is preferably 1 to 30% by mass, more preferably 5 to 20% by mass, from the viewpoints that the polymer is less likely to precipitate and a high molecular weight product is easily obtained.

[0100] The polyamic acid obtained as described above can be recovered by injecting the reaction solution into a poor solvent while thoroughly stirring it to precipitate the polymer. In addition, the precipitation can be carried out several times, washed with a poor solvent, and then dried at room temperature or by heating to obtain a purified polyamic acid powder. The poor solvent is not particularly limited, but examples thereof include water, methanol, ethanol, hexane, butyl cellosolve, acetone, and toluene.

[0101] <Polyamic acid ester> The polyamic acid ester, which is one of the polyimide precursors used in the present invention, can be produced by the following method (1), (2) or (3).

[0102] (1) Manufacturing from polyamic acid The polyamic acid ester can be synthesized by esterifying a polyamic acid obtained from a tetracarboxylic dianhydride and a diamine, specifically by reacting a polyamic acid with an esterifying agent in the presence of an organic solvent at −20° C. to 150° C., preferably 0° C. to 50° C., for 30 minutes to 24 hours, preferably 1 to 4 hours.

[0103] The esterification agent is preferably one that can be easily removed by purification, and examples of the esterification agent include N,N-dimethylformamide dimethyl acetal, N,N-dimethylformamide diethyl acetal, N,N-dimethylformamide dipropyl acetal, N,N-dimethylformamide dineopentyl butyl acetal, N,N-dimethylformamide di-t-butyl acetal, 1-methyl-3-p-tolyltriazene, 1-ethyl-3-p-tolyltriazene, 1-propyl-3-p-tolyltriazene, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride, etc. The amount of the esterification agent used is preferably 2 to 6 molar equivalents per mole of the repeating unit of the polyamic acid.

[0104] The solvent used in the above reaction is preferably N,N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone in terms of the solubility of the polymer, and these may be used alone or in combination of two or more. The concentration of the polymer in the reaction solution is preferably 1 to 30% by mass, more preferably 5 to 20% by mass, from the viewpoints that the polymer is unlikely to precipitate and a high molecular weight product is easily obtained.

[0105] (2) When produced by reacting a tetracarboxylic acid diester dichloride with a diamine The polyamic acid ester can be produced from a tetracarboxylic acid diester dichloride and a diamine. Specifically, the polyamic acid ester can be synthesized by reacting the tetracarboxylic acid diester dichloride and the diamine in the presence of a base and an organic solvent at −20° C. to 150° C., preferably 0° C. to 50° C., for 30 minutes to 24 hours, preferably 1 to 4 hours.

[0106] The base may be pyridine, triethylamine, 4-dimethylaminopyridine, etc., but pyridine is preferred because the reaction proceeds mildly. The amount of the base used is preferably 2 to 4 times the molar amount of the tetracarboxylic acid diester dichloride, from the viewpoints of easy removal and easy production of a high molecular weight compound.

[0107] The solvent used in the above reaction is preferably N-methyl-2-pyrrolidone or γ-butyrolactone in terms of the solubility of the monomer and polymer, and these may be used alone or in combination of two or more. The polymer concentration in the reaction solution is preferably 1 to 30% by mass, more preferably 5 to 20% by mass, from the viewpoint of preventing precipitation of the polymer and facilitating the production of a high molecular weight polymer. In addition, in order to prevent hydrolysis of the tetracarboxylic acid diester dichloride, it is preferable that the solvent used in the synthesis of the polyamic acid ester is as dehydrated as possible, and it is preferable to use a nitrogen atmosphere to prevent the inclusion of outside air.

[0108] (3) Production by reacting a tetracarboxylic acid diester with a diamine The polyamic acid ester can be produced by polycondensing a tetracarboxylic acid diester and a diamine, specifically, by reacting a tetracarboxylic acid diester and a diamine in the presence of a condensing agent, a base, and an organic solvent at 0° C. to 150° C., preferably 0° C. to 100° C., for 30 minutes to 24 hours, preferably 3 to 15 hours.

[0109] The condensing agent may be triphenyl phosphite, dicyclohexylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, N,N'-carbonyldiimidazole, dimethoxy-1,3,5-triazinylmethylmorpholinium, O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate, O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, (2,3-dihydro-2-thioxo-3-benzoxazolyl)diphenylphosphonate, etc. The amount of the condensing agent added is preferably 2 to 3 times the molar amount of the tetracarboxylic acid diester.

[0110] The base may be a tertiary amine such as pyridine, triethylamine, etc. The amount of the base used is preferably 2 to 4 times the molar amount of the diamine component, from the viewpoints of easy removal and easy production of a high molecular weight substance.

[0111] In the above reaction, the reaction can be efficiently carried out by adding a Lewis acid as an additive. The Lewis acid is preferably a lithium halide such as lithium chloride or lithium bromide. The amount of Lewis acid added is preferably 0 to 1.0 times the molar amount of the diamine component.

[0112] Among the above three methods for producing a polyamic acid ester, the above production method (1) or (2) is particularly preferred since it gives a high molecular weight polyamic acid ester.

[0113] The polyamic acid ester solution obtained as described above can be poured into a poor solvent while being thoroughly stirred to precipitate the polymer. Precipitation can be carried out several times, washed with a poor solvent, and then dried at room temperature or by heating to obtain a purified polyamic acid ester powder. The poor solvent is not particularly limited, but examples thereof include water, methanol, ethanol, hexane, butyl cellosolve, acetone, and toluene.

[0114] <Polyimide> The polyimide used in the present invention can be produced by imidizing the polyamic acid or polyamic acid ester. The imidization rate of the polyimide used in the present invention is not limited to 100%. From the viewpoint of electrical properties, it is preferably 20 to 99%. When producing a polyimide from a polyamic acid ester, chemical imidization is simple, in which a basic catalyst is added to the polyamic acid ester solution or a polyamic acid solution obtained by dissolving a polyamic acid ester resin powder in an organic solvent. Chemical imidization is preferable because the imidization reaction proceeds at a relatively low temperature and the molecular weight of the polymer is less likely to decrease during the imidization process.

[0115] Chemical imidization can be carried out by stirring the polyamic acid or polyamic acid ester to be imidized in an organic solvent in the presence of a basic catalyst and an acid anhydride. In addition, by reacting the compounds shown in (R-1) to (R-2) above, a polyimide precursor having a specific structure introduced at the end can be obtained. The organic solvent can be the solvent used in the polymerization reaction described above. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Among these, pyridine is preferred because it has a suitable basicity for promoting the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride, and among these, the use of acetic anhydride is preferred because it makes purification after the reaction easy. Usually, in the case of conventional polyimides, when acetic anhydride is used, an acetyl group is generated as the main chain end, whereas the present invention can suppress acetylation.

[0116] [ka]

[0117] R 22 , R 22 ' represents a monovalent organic group, specific examples of which include a methyl group, an ethyl group, a propyl group, a 2,2,2-trichloroethyl group, a 2-trimethylsilylethyl group, a 1,1-dimethylpropynyl group, a 1-methyl-1-phenylethyl group, a 1-methyl-1-(4-biphenylyl)ethyl group, a 1,1-dimethyl-2-haloethyl group, a 1,1-dimethyl-2-cyanoethyl group, a tert-butyl group, a cyclobutyl group, a 1-methylcyclobutyl group, a 1-adamantyl group, a vinyl group, an allyl group, a cinnamyl group, an 8-quinolyl group, an N-hydroxypiperidinyl group, a benzyl group, a p-nitrobenzyl group, a 3,4-dimethoxy-6-nitrobenzyl group, a 2,4-dichlorobenzyl group, and a 9-fluorenylmethyl group.

[0118] The temperature when carrying out the imidization reaction is, for example, -20°C to 120°C, preferably 0°C to 100°C, and the reaction time can be 1 to 100 hours. The amount of the basic catalyst is 0.5 to 30 times by mole, preferably 2 to 20 times by mole, the amic acid group, and the amount of the acid anhydride is 1 to 50 times by mole, preferably 3 to 30 times by mole, the amic acid group. The imidization rate of the obtained polymer can be controlled by adjusting the amount of the catalyst, the temperature, and the reaction time.

[0119] Since the added catalyst and the like remain in the solution after the imidization reaction of the polyamic acid ester or polyamic acid, it is preferable to recover the obtained imidized polymer by the means described below and re-dissolve it in an organic solvent to obtain the liquid crystal aligning agent of the present invention.

[0120] The polyimide solution obtained as described above can be poured into a poor solvent while being thoroughly stirred to precipitate the polymer. The precipitation is carried out several times, washed with a poor solvent, and then dried at room temperature or by heating to obtain a purified powder of polyamic acid ester.

[0121] The poor solvent is not particularly limited, but examples thereof include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, and benzene.

[0122] <Liquid crystal alignment agent> The liquid crystal aligning agent of the present invention has the form of a solution in which a polymer containing a specific polymer is dissolved in an organic solvent containing a specific solvent. The molecular weight of the polyimide precursor and polyimide described in the present invention is preferably 2,000 to 500,000, more preferably 5,000 to 300,000, and even more preferably 10,000 to 100,000, in terms of weight average molecular weight. The number average molecular weight is preferably 1,000 to 250,000, more preferably 2,500 to 150,000, and even more preferably 5,000 to 50,000.

[0123] The concentration of the polymer of the liquid crystal alignment agent used in the present invention can be appropriately changed depending on the thickness of the coating film to be formed, but it is preferably 1% by weight or more from the viewpoint of forming a uniform and defect-free coating film, and is preferably 10% by weight or less from the viewpoint of storage stability of the solution.

[0124] The solvent in the liquid crystal alignment agent of the present invention is preferably a solvent that dissolves the polyimide precursor and polyimide (also called a good solvent), or a solvent that improves the coating property and surface smoothness of the liquid crystal alignment film when the liquid crystal alignment agent is applied (also called a poor solvent). Specific examples of other solvents are listed below, but are not limited to these examples.

[0125] Specific examples of good solvents include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-butyl-2-pyrrolidone, γ-butyrolactone, γ-valerolactone, 1,3-dimethylimidazolidinone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropanamide, and 4-hydroxy-4-methyl-2-pentanone.

[0126] Specific examples of poor solvents include 1-butoxy-2-propanol, 2-butoxy-1-propanol, 2-propoxyethanol, 2-(2-propoxyethoxy)ethanol, 1-propoxy-2-propanol ethanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, and neopentyl alcohol. , 1-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3 -Butanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 2-pentanone, 3-pentanone, 2-hexanone, 2- Heptanone, 4-heptanone, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, 2-(methoxymethoxy)ethanol, butyl cellosolve, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2-(hexyloxy)ethanol, furfuryl alcohol, diethylene glycol, propylene glycol,1-(butoxyethoxy)propanol, propylene glycol monomethyl ether acetate, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene glycol monoethyl ether acetate, propylene glycol diacetate, diisopentyl ether, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene Examples of the lactic acid monomer include propylene glycol acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether 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, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate, diisobutyl ketone, and ethyl carbitol.

[0127] As the poor solvent, a solvent represented by the following formula is also preferably used.

[0128] [ka] R 24、 R 25 are each independently a linear or branched alkyl group having 1 to 8 carbon atoms. 24 +R 25 is an integer greater than 3.

[0129] As the poor solvent, when the polyimide precursor and polyimide contained in the liquid crystal alignment agent have high solubility in the solvent, the solvents represented by the following formulas [D-1] to [D-3] are preferable.

[0130] [ka]

[0131] In formula [D-1], D 1 represents an alkyl group having 1 to 3 carbon atoms, and in formula [D-2], D 2 represents an alkyl group having 1 to 3 carbon atoms, and in formula [D-3], D 3 represents an alkyl group having 1 to 4 carbon atoms.

[0132] In addition, the liquid crystal aligning agent of the present invention may contain a crosslinkable compound having an epoxy group, an isocyanate group, an oxetane group or a cyclocarbonate group, a crosslinkable compound having at least one substituent selected from the group consisting of a hydroxyl group, a hydroxyalkyl group and a lower alkoxyalkyl group, or a crosslinkable compound having a polymerizable unsaturated bond.

[0133] As such a crosslinking compound, various known compounds can be used depending on the purpose. The following compounds are preferably used:

[0134] [ka]

[0135] The content of the crosslinkable compound is preferably 0.1 to 150 parts by mass relative to 100 parts by mass of all polymer components. In particular, in order to allow the crosslinking reaction to proceed and to exhibit the intended effect, the content is preferably 0.1 to 100 parts by mass, and more preferably 1 to 50 parts by mass.

[0136] The liquid crystal aligning agent of the present invention may contain a compound that improves the uniformity of the film thickness and the surface smoothness of the liquid crystal alignment film when the liquid crystal aligning agent is applied.

[0137] Examples of compounds that improve the uniformity of the thickness and surface smoothness of the liquid crystal alignment film include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants.

[0138] The amount of the surfactant used is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, based on 100 parts by mass of all polymer components contained in the liquid crystal aligning agent.

[0139] <Liquid crystal alignment film / Liquid crystal display element> The liquid crystal alignment agent of the present invention can be used as a liquid crystal alignment film by applying it to a substrate, baking it, and then performing an alignment treatment such as rubbing treatment or light irradiation. In addition, in the case of vertical alignment, it can be used as a liquid crystal alignment film without performing the alignment treatment.

[0140] The liquid crystal alignment film of the present invention can be used as a horizontal alignment type or vertical alignment type (VA mode, PSA mode, SC-PVA mode, etc.) liquid crystal alignment film, and is particularly suitable for vertical alignment type liquid crystal display elements such as PSA mode and SC-PVA mode, and can control the pretilt with a small amount of light irradiation.

[0141] The substrate used in this case is not particularly limited as long as it is a highly transparent substrate, and in addition to a glass substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate can also be used. From the viewpoint of simplifying the process, it is preferable to use a substrate on which an ITO electrode for driving the liquid crystal is formed. In addition, in a reflective liquid crystal display element, an opaque substrate such as a silicon wafer can be used for only one substrate, and in this case, a light-reflecting material such as aluminum can also be used for the electrode.

[0142] The method of applying the liquid crystal alignment agent is not particularly limited, but in industry, it is generally performed by screen printing, offset printing, flexographic printing, inkjet printing, etc. Other application methods include a dip method, a roll coater method, a slit coater method, a spinner method, a spray method, etc., and these may be used depending on the purpose.

[0143] After the liquid crystal alignment agent is applied onto the substrate, the solvent can be evaporated at a temperature of 30 to 300°C, preferably 30 to 250°C, depending on the solvent used in the liquid crystal alignment agent, by a heating means such as a hot plate, a heat circulation type oven, or an IR (infrared) type oven, to obtain a liquid crystal alignment film. If the liquid crystal alignment film after baking is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may decrease, so the thickness is preferably 5 to 300 nm, more preferably 10 to 100 nm. When the liquid crystal is to be horizontally aligned or tilted aligned, the liquid crystal alignment film after baking is treated by rubbing or irradiation with polarized ultraviolet light, or the like.

[0144] The liquid crystal display element of the present invention is obtained by obtaining a substrate with a liquid crystal alignment film from the liquid crystal aligning agent of the present invention by the above-mentioned method, and then producing a liquid crystal cell by a known method to obtain a liquid crystal display element.

[0145] Examples of methods for producing a liquid crystal cell include a method of preparing a pair of substrates each having a liquid crystal alignment film formed thereon, spraying spacers onto the liquid crystal alignment film of one of the substrates, bonding the other substrate to the other substrate with the liquid crystal alignment film surface facing inward, and injecting liquid crystal under reduced pressure to seal the cell, or a method of dropping liquid crystal onto the liquid crystal alignment film surface on which the spacers have been sprayed, and then bonding the substrates together to seal the cell.

[0146] Furthermore, the liquid crystal aligning agent of the present invention is also preferably used for a liquid crystal display element which has a liquid crystal layer between a pair of substrates equipped with electrodes, and is manufactured by disposing a liquid crystal composition containing a polymerizable compound which is polymerized by at least one of active energy rays and heat between the pair of substrates, and polymerizing the polymerizable compound by at least one of irradiation with active energy rays and heating while applying a voltage between the electrodes. Here, ultraviolet rays are suitable as the active energy rays. The ultraviolet rays have a wavelength of 300 to 400 nm, preferably 310 to 360 nm. In the case of polymerization by heating, the heating temperature is 40 to 120° C., preferably 60 to 80° C. Moreover, ultraviolet rays and heating may be performed simultaneously.

[0147] The above liquid crystal display element controls the pretilt of liquid crystal molecules by the PSA (Polymer Sustained Alignment) method. In the PSA method, a small amount of photopolymerizable compound, for example, photopolymerizable monomer, is mixed into the liquid crystal material, and after assembling a liquid crystal cell, the photopolymerizable compound is irradiated with ultraviolet light or the like while a predetermined voltage is applied to the liquid crystal layer, and the pretilt of the liquid crystal molecules is controlled by the generated polymer. Since the alignment state of the liquid crystal molecules when the polymer is generated is stored even after the voltage is removed, the pretilt of the liquid crystal molecules can be adjusted by controlling the electric field formed in the liquid crystal layer. In addition, the PSA method does not require a rubbing process, so it is suitable for forming a vertical alignment type liquid crystal layer in which it is difficult to control the pretilt by a rubbing process.

[0148] That is, the liquid crystal display element of the present invention can be produced by obtaining a substrate with a liquid crystal alignment film from the liquid crystal alignment agent of the present invention by the above-mentioned method, producing a liquid crystal cell, and polymerizing the polymerizable compound by at least one of irradiation with ultraviolet light and heating, thereby controlling the alignment of the liquid crystal molecules.

[0149] An example of a method for producing a liquid crystal cell using the PSA method is to prepare a pair of substrates each having a liquid crystal alignment film formed thereon, spray spacers onto the liquid crystal alignment film of one substrate, attach the other substrate to the substrate with the liquid crystal alignment film surface facing inward, and then inject liquid crystal under reduced pressure to seal the cell. Alternatively, there is a method in which liquid crystal is dropped onto the liquid crystal alignment film surface on which the spacers have been sprayed, and then the substrates are attached to seal the cell.

[0150] A polymerizable compound that polymerizes by heat or ultraviolet irradiation is mixed into the liquid crystal. Examples of the polymerizable compound include compounds having one or more polymerizable unsaturated groups in the molecule, such as an acrylate group or a methacrylate group. In this case, the polymerizable compound is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the liquid crystal component. If the polymerizable compound is less than 0.01 part by mass, the polymerizable compound does not polymerize, making it impossible to control the alignment of the liquid crystal, and if it is more than 10 parts by mass, the amount of unreacted polymerizable compound increases, resulting in a deterioration in the burn-in characteristics of the liquid crystal display element.

[0151] After the liquid crystal cell is prepared, the polymerizable compound is polymerized by irradiating the liquid crystal cell with heat or ultraviolet light while applying an AC or DC voltage to the liquid crystal cell, thereby controlling the alignment of the liquid crystal molecules.

[0152] In addition, the liquid crystal alignment agent of the present invention is preferably used for a liquid crystal display element, i.e., an SC-PVA mode, which is manufactured by a process of having a liquid crystal layer between a pair of substrates equipped with electrodes, disposing a liquid crystal alignment film containing a polymerizable group that is polymerized by at least one of active energy rays and heat between the pair of substrates, and applying a voltage between the electrodes. Here, ultraviolet rays are suitable as the active energy rays. The ultraviolet rays have a wavelength of 300 to 400 nm, preferably 310 to 360 nm. In the case of polymerization by heating, the heating temperature is 40 to 120°C, preferably 60 to 80°C. Moreover, ultraviolet rays and heating may be performed simultaneously.

[0153] In order to obtain a liquid crystal alignment film containing a polymerizable group that is polymerized by at least one of active energy rays and heat, a method of adding a compound containing this polymerizable group to a liquid crystal alignment agent, or a method of using a polymer component containing a polymerizable group can be mentioned. Specific examples of polymers containing polymerizable groups are not particularly limited as long as they are polymers having the above-mentioned photoreactive group, and include polymers obtained by using diamines having the above-mentioned photoreactive group.

[0154] An example of a method for producing a liquid crystal cell in SC-PVA mode includes a method of preparing a pair of substrates on which the liquid crystal alignment film of the present invention is formed, spraying spacers onto the liquid crystal alignment film of one substrate, bonding the other substrate with the liquid crystal alignment film surface facing inward, and injecting liquid crystal under reduced pressure to seal the cell, or a method of dropping liquid crystal onto the liquid crystal alignment film surface on which the spacers have been sprayed, and then bonding the substrates together to seal the cell.

[0155] After the liquid crystal cell is prepared, the orientation of the liquid crystal molecules can be controlled by applying an AC or DC voltage to the liquid crystal cell while irradiating it with heat or ultraviolet light. EXAMPLES

[0156] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0157] The abbreviations of the compounds used in the examples and comparative examples and the methods of evaluating the characteristics are as follows. (solvent) NMP: N-methyl-2-pyrrolidone, BCS: Butyl cellosolve (acid dianhydride) DC-1: 1,2,3,4-cyclobutanetetracarboxylic dianhydride DC-2: Bicyclo[3,3,0]octane-2,4,6,8-tetrachloride carboxylic acid dianhydride, (Diamine) DA-1: 1,3-bis(4-aminophenethyl)urea DA-2: 4-(2-methylaminoethyl)aniline DA-3: 1,5-bis(4-aminophenoxy)pentane DA-4: 3,5-diaminobenzoic acid DA-5: Diamine compound represented by the following formula DA-5

[0158] [ka]

[0159] (Specific compound) [ka]

[0160] (Comparative Compound) [ka]

[0161] AD-1 to AD-5 are novel compounds not yet disclosed in the literature, and their synthesis methods are described in detail in the following Synthesis Examples 1 to 5.

[0162] < 1 HNMR Measurement> Equipment: Fourier transform superconducting nuclear magnetic resonance spectrometer (FT-NMR) "AVANCE III" (BRUKER) 500MHz. Solvent: deuterated chloroform (CDCl3) or deuterated dimethylsulfoxide ([D6]-DMSO). Standard substance: tetramethylsilane (TMS).

[0163] <Synthesis Example 1: Synthesis of [AD-1]>

[0164] [ka]

[0165] 4-[(trans, trans)-4'-pentyl[1,1'-bicyclohexyl]-4-yl]phenol (25.9g, 78.8mmol), 20wt% potassium hydroxide aqueous solution (79.8g), tert-butyl alcohol (77.8g), tetrahydrofuran (40.1g), and formaldehyde aqueous solution (37%, 64.1g) were charged into a 500mL four-neck flask and reacted for about 3 days at room temperature. After the reaction was completed, the reaction solution was poured into a two-phase solution of ethyl acetate (390g) and 2.0mol / L hydrochloric acid aqueous solution (222g), and the target substance was extracted into the organic phase. The organic phase was then washed three times with pure water (150g). The organic phase was dehydrated with sodium sulfate and concentrated under reduced pressure to remove the solvent. The concentrate was dissolved in tetrahydrofuran (88.0 g) by heating at 40°C, and toluene (153 g) was added to precipitate crystals. After stirring under ice-cooling conditions, the crystals were filtered, washed with hexane, and dried to obtain [AD-1] as white crystals (yield: 14.1 g, 46%). 1 H NMR (500 MHz, [D6]-DMSO):δ8.32 (br,1H), 6.96 (s,2H), 5.17 (br,2H), 4.52(s,4H), 2.29-2.34(m,1H), 1.70-1.79(m,8H), 0.95-1.36(m,22H)

[0166] <Synthesis Example 2: Synthesis of [AD-2]>

[0167] [ka]

[0168] In a 500mL four-neck flask, p-(trans-4-heptylcyclohexyl)phenol (30.2g, 110mmol), 20wt% potassium hydroxide aqueous solution (114g), tert-butyl alcohol (90.5g), and formaldehyde aqueous solution (37%, 108g) were charged and reacted at room temperature for about 3 days. After the reaction was completed, the reaction solution was poured into a two-phase solution of ethyl acetate (450g) and 2.0mol / L hydrochloric acid aqueous solution (184g), and the target substance was extracted into the organic phase. The organic phase was then washed three times with pure water (150g). After the organic phase was dehydrated with sodium sulfate, it was concentrated under reduced pressure to an internal weight of 120g. Hexane (360g) was added to the concentrated solution, and crystals were precipitated under ice-cooling conditions. The solution was filtered, washed with hexane, and dried to obtain [AD-2] as white crystals (yield: 11.3g, yield: 31%). 1 H NMR (500 MHz,CDCl3):δ7.92(br,1H), 6.89 (s,2H), 4.76 (s,4H), 2.70(br,2H), 2.32-2.39 (m,1H), 1.80-1.85(m, 4H), 1.18-1.43(m, 15H), 0.87-1.05(m,5H)

[0169] <Synthesis Example 3: Synthesis of [AD-3]>

[0170] [ka]

[0171] (Synthesis of [AD-3-1] and [AD-3-2]) A 1L four-neck flask was charged with p-(trans-4-heptylcyclohexyl)phenol (50.1g, 183mmol), N,N-dimethylacetamide (150g), and potassium carbonate (30.4g, 220mmol), and 2-bromoethanol (25.4g, 203mmol) was added dropwise under heating at 80°C. The reaction was tracked, and potassium carbonate (total amount added: 91.1g, 659mmol) and 2-bromoethanol (total amount added: 77.3g, 619mmol) were added as appropriate to eliminate the raw materials. After the reaction was completed, the reaction solution was diluted with ethyl acetate (1000g), and the organic phase was washed three times with pure water (500g). The organic phase was concentrated under reduced pressure to obtain [AD-3-1] as an oil compound (crude yield: 75.1g).

[0172] [AD-3-1] (75.1 g), tetrahydrofuran (402 g), 4-dimethylaminopyridine (2.22 g, 18.2 mmol), and triethylamine (28.1 g, 278 mmol) were charged into a 1 L four-neck flask, and p-toluenesulfonyl chloride (40.4 g, 237 mmol) was added little by little under ice-cooled conditions in a nitrogen atmosphere. After the addition, the reaction was carried out at room temperature to cause the raw materials to disappear. After the reaction was completed, the reaction solution was filtered to remove the precipitate. The filtrate was then concentrated under reduced pressure to remove the solvent. The concentrate was dissolved in ethyl acetate, and the organic phase was washed with pure water. The organic phase was dehydrated with magnesium sulfate, and then concentrated under reduced pressure to obtain a crude product. The crude product was dissolved in a mixed solution of ethyl acetate (92.0 g) and methanol (377 g) by heating at 60°C, and crystals were precipitated under ice-cooling conditions. The crystals were filtered and dried to obtain [AD-3-2] as white crystals (yield: 54.4 g, 63%).

[0173] (Synthesis of AD-3) 3,3',5,5'-Tetrakis(methoxymethyl)-[1,1'-biphenyl]-4,4'-diol (9.56g, 26.4mmol), N,N-dimethylacetamide (95.6g), potassium carbonate (8.80g, 63.7mmol) were charged into a 500mL four-neck flask, and [AD-3-2] (26.2g, 55.4mmol) was added under heating conditions at 70℃, and the reaction was carried out at the same temperature for about 1 day. After the reaction was completed, the reaction solution was diluted with ethyl acetate (500g), and the organic phase was washed three times with pure water (200g). The organic phase was dehydrated with magnesium sulfate and concentrated under reduced pressure to an internal weight of 109g. Methanol (220g) was added to the obtained solution to precipitate crystals, and crude crystals were obtained by filtration. The crude crystals were dissolved in ethyl acetate (122 g) at 70° C. by heating, and the crystals were precipitated at room temperature. The crystals were filtered and dried to obtain AD-3 as pale yellow crystals (yield: 15.2 g, 60%). 1 H NMR (500 MHz, CDCl3):δ7.59 (s,4H), 7.14 (d,4H,J=10Hz), 6.91 (d,4H,J=8.6Hz), 4.59 (s,8H), 4.27-4.29(m,8H), 3.41(s,12H), 2.39-2.45(m,2H), 1.85-1.88(m,8H), 0.90-1.45(m, 40H)

[0174] <Synthesis Example 4: Synthesis of [AD-4]>

[0175] [ka]

[0176] AD-2 (28.6 g, 85.5 mmol), methanol (1143 g), potassium carbonate (8.80 g, 63.7 mmol), and concentrated sulfuric acid (0.839 g, 8.55 mmol) were charged into a 300 mL four-neck flask and reacted for 24 hours under nitrogen atmosphere methanol reflux conditions. After the reaction was completed, the reaction solution was diluted with ethyl acetate (573 g), and the organic phase was washed once with saturated sodium bicarbonate aqueous solution (229 g) and twice with pure water (229 g). The organic phase was collected and concentrated under reduced pressure to remove the solvent. The concentrate was dissolved in hexane (345 g), and crystals were precipitated using ethanol / dry ice as a refrigerant, followed by filtration and drying to obtain AD-4 as white crystals (yield: 17.4 g, yield: 56%). 1 H NMR (500 MHz, CDCl3):δ7.58 (s,1H), 6.95 (s,2H), 4.57(s,4H), 3.43(s,6H), 2.34-2.39(m, 1H), 1.83-1.85(m,4H), 1.20-1.40 (m,15H), 0.87-1.02(m,5H)

[0177] <Synthesis Example 5: Synthesis of [AD-5]>

[0178] [ka]

[0179] AD-4 (5.00 g, 13.8 mmol) and potassium carbonate (2.67 g, 19.3 mmol) were charged into a 100 mL four-neck flask, and methyl iodide (2.35 g, 16.6 mmol) was added dropwise under heating at 80°C in a nitrogen atmosphere. The reaction was allowed to proceed for 22 hours at the same temperature to allow the raw materials to disappear. After the reaction was completed, the reaction solution was diluted with ethyl acetate (75.0 g), washed three times with pure water (40.0 g), and the organic phase was dehydrated with magnesium sulfate. After the dehydration, activated carbon (brand: Tokusei Shirasagi, 0.250 g) was added to the organic phase, and the mixture was stirred at room temperature for 1 hour. After removing the activated carbon by filtration, the mixture was concentrated under reduced pressure to obtain AD-5 as a pale yellow oily compound (yield: 5.00 g, yield: 95%). 1H NMR (500 MHz, CDCl3):δ7.18(s,2H), 4.48(s,4H), 3.78 (s,3H), 3.42(s,6H), 2.41-2.47(m, 1H), 1.83-1.89(m,4H), 1.20-1.40 (m,15H), 0.87-1.06(m,5H)

[0180] The methods for measuring the various characteristics and the methods for preparing the measurement samples therefor are as follows.

[0181] "viscosity" The viscosity of the polyamic acid solution was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample amount of 1.1 mL (milliliters), a cone rotor TE-1 (1°34', R24), and a temperature of 25°C.

[0182] "Synthesis of polyamic acid (PAA-1)" 2.63g (8.80mmol) of DA-1, 1.32g (8.80mmol) of DA-2, and 1.26g (4.40mmol) of DA-3 were weighed out into a 100mL four-neck flask equipped with a stirrer, and 61.5g of NMP was added and stirred to dissolve. While stirring this diamine solution, 4.10g (20.9mmol) of DC-1 was added, and then 22.3g of NMP was added. The mixture was stirred at 40℃ for 15 hours to obtain a polyamic acid solution (PAA-1, viscosity: 140mPa s). 84 g of this polyamic acid (PAA-1) solution was transferred to a 200 mL Erlenmeyer flask and diluted with 21.0 g of NMP and 35.0 g of BCS to prepare a polyamic acid (PAA-1) solution (liquid crystal alignment agent [PAA-0]) containing 6 mass % polyamic acid (PAA-1), 69 mass % NMP, and 25 mass % BCS.

[0183] "Synthesis of soluble polyimide (SPI-1)" 3.04g (20.0mmol) of DA-4 and 7.61g (20.0mmol) of DA-5 were weighed out into a 100mL four-neck flask equipped with a stirrer, and 58.6g of NMP was added and stirred to dissolve. 7.51g (30.0mmol) of DC-2 was added while stirring this diamine solution, and then 17.1g of NMP was added and stirred at 60℃ for 3 hours. Next, 1.80g (9.20mmol) of DC-1 was added while stirring this solution, and then 4.15g of NMP was added and stirred at 40℃ for 15 hours to obtain a polyamic acid solution (viscosity: 680mPa·s). NMP was added to this polyamic acid solution (80 g) to dilute it to 6.5% by mass, and then acetic anhydride (16.3 g) and pyridine (5.07 g) were added as imidization catalysts and reacted at 100 ° C. for 3 hours. This reaction solution was poured into methanol (1.0 L) and the resulting precipitate was filtered off. This precipitate was washed with methanol and dried under reduced pressure at 100 ° C. to obtain polyimide powder (SPI-1). The imidization rate of this polyimide was 57%. NMP (108 g) was added to the polyimide powder (SPI-1) (12.0 g) obtained above, and the mixture was stirred at 80 ° C. for 20 hours to dissolve it, and then BCS (80 g) was added and stirred at room temperature for 10 hours to prepare a soluble polyimide (SPI-1) solution (liquid crystal alignment agent [SPI-0]) containing 6% by mass of polyimide (SPI-1), 54% by mass of NMP, and 40% by mass of BCS.

[0184] "Preparation of liquid crystal alignment agent" <Examples 1 to 13 and Comparative Example 1> To the polyamic acid (PAA-1) solution (10.0 g) prepared above, the compounds AD-1 to AD-5 synthesized above as specific compounds were added in the ratios shown in Table 1 below relative to the solid content of the polyamic acid (PAA-1) solution (i.e., polyamic acid (PAA-1)), and the mixture was stirred at room temperature until a uniform solution was obtained, thereby preparing the liquid crystal alignment agents [PAA-1] to [PAA-13] and [PAA-0].

[0185] [Table 1]

[0186] <Examples 14 to 22 and Comparative Examples 2 to 4> To the soluble polyimide (SPI-1) solution (10.0 g) prepared above, the compounds AD-1 to 5 synthesized above and the comparative compounds AD-6 and 7 were added as specific compounds in the ratios shown in Table 2 below relative to the solid content of the soluble polyimide (SPI-1) solution (i.e., soluble polyimide (SPI-1)), and the mixture was stirred at room temperature until a homogeneous solution was obtained, to prepare [SPI-1] to [SPI-11] and [SPI-0].

[0187] [Table 2]

[0188] "Preparation of liquid crystal alignment film and liquid crystal cell" Using the liquid crystal alignment agents prepared in the above respective Examples, liquid crystal cells were produced as follows.

[0189] The liquid crystal alignment agent prepared in each of the above Examples was spin-coated on the ITO surface of an ITO electrode substrate on which an ITO electrode pattern with a pixel size of 100 μm × 300 μm and a line / space of 5 μm each was formed, and then dried on a hot plate at 70°C for 90 seconds and baked in a hot air circulating oven at 230°C for 30 minutes to form a liquid crystal alignment film with a thickness of 100 nm. In addition, a liquid crystal alignment agent was spin-coated onto the ITO surface on which no electrode pattern was formed, and the surface was dried on a hot plate at 70°C for 90 seconds. After that, the surface was baked in a hot air circulating oven at 230°C for 20 minutes to form a liquid crystal alignment film with a thickness of 100 nm. For the two substrates, 4 μm bead spacers were sprayed on the liquid crystal alignment film of one substrate, and then a sealant (solvent-based thermosetting epoxy resin) was printed on top of the bead spacers. Next, the other substrate was attached to the previous substrate with the side on which the liquid crystal alignment film was formed facing inward, and the sealant was cured to prepare an empty cell. PSA polymerizable compound-containing liquid crystal MLC-3023 (Merck product name) was injected into this empty cell by the reduced pressure injection method to prepare a liquid crystal cell. After that, with a DC voltage of 15 V applied to the liquid crystal cell, UV light of 10 J / cm2 was applied from the outside of the liquid crystal cell through a filter that cuts wavelengths of 325 nm or less. 2 The UV illuminance was measured using a UV-MO3A manufactured by ORC Corp. After that, in order to inactivate the unreacted polymerizable compound remaining in the liquid crystal cell, the cell was irradiated with UV (UV lamp: FLR40SUV32 / A-1) for 30 minutes using a UV-FL irradiation device manufactured by Toshiba Lighting & Technology Corp. in a state where no voltage was applied.

[0190] "Evaluation of Liquid Crystal Cells" The physical properties of each of the prepared liquid crystal cells were measured and the characteristics were evaluated as follows. (Vertical alignment evaluation) The liquid crystal cell was sandwiched between polarizing plates and irradiated from the rear with a backlight. The liquid crystal cell was rotated and visually observed to see whether the liquid crystal was vertically aligned based on changes in brightness and the presence or absence of bright spots. (Measurement of pretilt angle) The LCD analyzer LCA-LUV42A manufactured by Meiryo Technica was used.

[0191] <Examples 23 to 35 and Comparative Example 5> <Vertical Alignment Evaluation> The vertical alignment property was evaluated using the liquid crystal alignment agents prepared in each Example shown in Table 3. The evaluation was based on the following criteria. The results are shown in Table 3.

[0192] As a result, in comparison example 5, in which no specific compound was added, the liquid crystal did not align vertically, bright spots occurred, and alignment was poor, whereas when a liquid crystal alignment agent containing specific compounds AD-1 to AD-5 was used, by adjusting the amount of addition, the occurrence of bright spots and alignment failure were eliminated, and vertical alignment was observed. Evaluation criteria ◎: Vertical alignment of liquid crystals is confirmed, and no bright spots are observed. ○: The liquid crystal is vertically aligned, but some bright spots are observed. ×: Liquid crystals are not aligned vertically, and many bright spots are observed.

[0193] [Table 3]

[0194] <Examples 36 to 40 and Comparative Examples 6 to 8> <Evaluation of Severe Baking Resistance> The pretilt angle of the liquid crystal cell prepared using the liquid crystal alignment agent prepared in each Example shown in Table 4 was measured. The time for baking in a hot air circulation oven at 230°C to form a liquid crystal alignment film was set to 20 minutes and 60 minutes. The change in the tilt angle at that time was taken as Δtilt. The results are shown in Table 4.

[0195] As a result, compared to Comparative Example 8 in which no specific compound was added, when the liquid crystal alignment agent containing the specific compounds AD-1 to AD-5 was used, the Δtilt was smaller in all cases, and it was confirmed that the vertical alignment ability was less likely to decrease due to severe baking and that the vertical alignment ability was high.

[0196] [Table 4]

[0197] "Preparation of liquid crystal alignment film and evaluation of film hardness" The liquid crystal alignment agents prepared in the above examples were used to evaluate the film hardness as follows: The film hardness was evaluated by observing the resistance to scraping with a rubbing cloth. A liquid crystal alignment agent was spin-coated onto the ITO surface on which no electrode pattern was formed, dried on a hot plate at 70°C for 90 seconds, and then baked in a hot air circulating oven at 230°C for 20 minutes to form a liquid crystal alignment film with a thickness of 100 nm.

[0198] The surface of the liquid crystal alignment film was rubbed with a rayon cloth using a rubbing device with a roll diameter of 120 mm under the following rubbing conditions: roll rotation speed 1000 rpm, roll advance speed 20 mm / sec, and push-in amount 0.5 mm, to obtain a rubbed substrate with a liquid crystal alignment film.

[0199] <Examples 41 to 47 and Comparative Example 9> <Evaluation of film hardness> The surface of the liquid crystal alignment film prepared using the liquid crystal alignment agent prepared in each Example shown in Table 5 was rubbed, and then observed with a confocal laser microscope (Keyence, VK-X200) and evaluated according to the following criteria. The results are shown in Table 5.

[0200] As a result, in the case of using the liquid crystal alignment agent containing the specific compounds AD-1 to AD-2 and AD-4, the film hardness was improved and no scraping due to rubbing was observed, compared with Comparative Example 9 in which no specific compound was added. However, the specific compound AD-3 did not show any improvement effect on the resistance to scraping due to rubbing. Evaluation criteria ◯: No scraping residue or rubbing scratches are observed. ×: Scraps or rubbing scratches are observed.

[0201] [Table 5] [Industrial Applicability]

[0202] By using the liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of the present invention, it is possible to impart and control a pretilt angle to the liquid crystal, and furthermore, it is possible to suppress the decrease in alignment, which is a disadvantage of using additives, and a liquid crystal display element with high display quality can be obtained. Therefore, it can be suitably used for liquid crystal display elements such as smartphones and mobile phones.

Claims

1. A compound represented by the following formula (1): Specific compound (A), in which Z is the following formula (Z-1), m is 0, n is 2, and q is 1: Specific compound (B) in which Z is the following formula (Z-1), m is 0, n is 1, and q is 1: Or a specific compound (C) in which Z is the following formula (Z-2), m is 1, n is 1, and q is 2. 【Chemistry 1】 【Chemistry 2】 In the formula (1), X 1 represents -(CH 2 ) a1 -A 1 -; a1 is an integer of 1 to 15, A 1 represents an oxygen atom, and X 2 represents a single bond. G 1 represents phenylene, G 2 represents cyclohexylene, and any hydrogen atom on the cyclic group of G 1 and G 2 may be substituted with an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, a fluorine-containing alkoxy group having 1 to 3 carbon atoms, or a fluorine atom. R 1 represents an alkyl group having 5 to 20 carbon atoms. m represents 0 or 1, n represents 1 or 2, and q represents 1 or 2. In the formula (Z-1) and formula (Z-2), Y 1 and Y 2 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxyalkyl group having 1 to 4 carbon atoms, and * represents a bond to X 1 .

2. The specific compound (A) is selected from the following formulas [A-6] to [A-8]: The specific compound (B) is selected from the following formulae [B-6] to [B-8], the following formulae [E-6] to [E-12], and the following formulae [G-6] to [G-10]: The specific compound (C) is a compound according to claim 1 selected from the following formulas [C-1] to [C-7]: 【Chemistry 3】 【Chemistry 4】 【Chemistry 5】 【Chemistry 6】 【Chemistry 7】

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