TWI791614B - Diamine, polymer, liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element - Google Patents

Abstract

The present invention provides a liquid crystal alignment film that is less prone to film peeling or scratches during rubbing, has a high voltage retention rate, has good aging resistance under high temperature and high humidity conditions, and has excellent adhesion to a sealant. The liquid crystal alignment agent for obtaining the liquid crystal alignment film, the polymer from which the liquid crystal alignment agent can be obtained, and the novel diamine compound used as a raw material for the polymer.

It is characterized in that the liquid crystal alignment agent contains a polymer having an oxazoline skeleton represented by formula (1).

(R ¹ represents hydrogen or a monovalent organic group, and * represents a bonding site with other groups.)

Description

Diamine, polymer, liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film obtained from the liquid crystal alignment agent, a liquid crystal display element with the liquid crystal alignment film, and novel diamines and polymers suitable for them.

Liquid crystal display devices are widely used in personal computers, mobile phones, smart phones, televisions, etc. In recent years, there are more and more opportunities to use liquid crystal display elements in high temperature and high humidity conditions such as car navigation or gauges mounted on vehicles, industrial equipment installed outdoors, or display parts of measuring equipment.

This type of liquid crystal display element generally has a liquid crystal layer sandwiched between the element substrate and the color filter substrate, pixel electrodes and common electrodes that apply an electric field to the liquid crystal layer, a liquid crystal alignment film that controls the alignment of liquid crystal molecules in the liquid crystal layer, and switching Thin film transistor (TFT) etc. for electrical signals supplied to pixel electrodes.

In the liquid crystal display element, the pixel electrode and the common electrode sandwich the liquid crystal layer and act as a liquid crystal unit. When the voltage holding ratio (VHR: Voltage Holding Ratio) of the liquid crystal cell is low, it becomes difficult to apply a sufficient voltage to the liquid crystal molecules even if a voltage is applied. Therefore, due to the high If the voltage retention rate is lowered under high temperature and high humidity or long-term use, the display contrast will decrease, or the display will flicker, etc., making the display difficult to see.

In particular, in TVs or car displays, these liquid crystal display elements use backlights that generate a lot of heat in order to achieve high brightness. Also, car navigation systems or meter panels used in car applications may be exposed to high temperatures for a long time. The following conditions of use or storage. Under such harsh conditions, the gradual change of the pretilt angle may cause the problem that the initial display characteristics cannot be obtained, resulting in unevenness in the display. In addition, the voltage retention characteristics and charge accumulation characteristics when driving liquid crystals are also affected by the liquid crystal alignment film. When the voltage retention rate is low, the contrast of the display screen will be reduced. When the charge accumulation for DC voltage is large, A phenomenon called burn-in occurs on the display screen.

One of the driving methods of such a liquid crystal display element is a method in which liquid crystal molecules that are vertically aligned with respect to the substrate respond to an electric field (also called a vertical alignment (VA) method). The liquid crystal display element of the vertical alignment method is known to add a photopolymerizable compound to the liquid crystal composition in advance and use a vertical alignment film such as a polyimide system to accelerate the liquid crystal by applying a voltage to the liquid crystal cell and irradiating ultraviolet rays at the same time. Response speed technology (polymer stabilized alignment, PSA (Polymer Sustained Alignment) type device, for example, refer to Patent Document 1 and Non-Patent Document 1).

Also, one of the driving methods of the liquid crystal display element is the method of making the liquid crystal molecules aligned horizontally to the substrate respond to the electric field (also known as the horizontal alignment (IPS: In-Plane Swiching) method). In the liquid crystal display element of the horizontal alignment mode, a method of controlling the alignment direction of the liquid crystal is generally known by using a horizontal alignment film such as polyimide, and rubbing the liquid crystal alignment film with a cloth (so-called rubbing treatment), and It is also widely used in industry now. This rubbing treatment is known to have a problem that the display quality of the display element is lowered due to dust or scratches generated by the abrasion of the liquid crystal alignment film. Therefore, the liquid crystal alignment film is required to have high rubbing resistance with little dust generated during rubbing or damage to the liquid crystal alignment film.

Patent Documents 2 and 3 disclose a liquid crystal alignment agent for the purpose of providing a liquid crystal alignment film that is unlikely to cause abrasion or damage to the coating film due to rubbing treatment. Furthermore, Patent Document 4 discloses a liquid crystal alignment agent aimed at providing a highly reliable liquid crystal alignment film with low ion density and high voltage retention even at high temperatures, in addition to the rubbing resistance of the liquid crystal alignment film. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Unexamined Patent Publication No. 2003-307720 [Patent Document 2] Japanese Patent Laid-Open No. 2008-203332 [Patent Document 3] International Publication 2010/053128 [Patent Document 4] International Publication 2010/050523 [Non-patent literature]

[Non-Patent Document 1] K. Hanaoka, SID 04 DIGEST, P1200-1202

[Problem to be Solved by the Invention]

In addition to the above, with the high performance of liquid crystal display elements in recent years, the expected characteristics of liquid crystal alignment films have gradually become more stringent. Therefore, it becomes more difficult for the conventional technology to respond to the expectation of the properties of the liquid crystal alignment film or the liquid crystal display element due to the high performance in recent years. In addition, in recent liquid crystal display devices, in order to enlarge the effective pixel area, the frame area where pixels are not formed is reduced on the peripheral frame portion of the substrate, which requires so-called thinner frame. With the thinner frame of the panel, it becomes necessary to coat the polyimide-based liquid crystal alignment film with a sealant used to make two substrates and then manufacture the liquid crystal display element, but since there is no Since there are few polar groups or polar groups, a covalent bond is not formed on the surface of the sealing agent and the liquid crystal alignment film, and there is a problem that the bonding between the substrates becomes insufficient. Therefore, it becomes a subject to improve the adhesion (adhesion) between the polyimide-based liquid crystal alignment film and the sealant or the substrate. In addition, the improvement of the adhesion between the liquid crystal alignment film and the sealant or the substrate must be achieved without reducing the liquid crystal alignment or electrical properties of the liquid crystal alignment film.

The problem to be solved by the present invention is to provide a liquid crystal that is less prone to film peeling or damage during rubbing, has a high voltage retention rate, has good aging resistance under high temperature and high humidity conditions, and has excellent adhesion to the sealant Alignment film, providing a liquid crystal alignment agent from which the liquid crystal alignment film can be obtained, providing a polymer from which the liquid crystal alignment agent can be obtained, and providing a novel diamine compound as a raw material of the polymer. [Means to solve the problem]

(R¹ 表示氫或一價有機基，＊表示與其他基之鍵結部位。) (2)如上述(1)之液晶配向劑，其中前述式(1)所示之噁唑啉骨架為源自二胺。 (3)如上述(1)之液晶配向劑，其中具有前述式(1)所示之噁唑啉骨架之聚合物為源自選自後述之式(2-1)、(2-2)及(2-4)之二胺之聚合物。 (4)如上述(1)之液晶配向劑，其中具有前述噁唑啉骨架之聚合物為源自由包含下述式(6)所示之構造單位之聚醯亞胺前驅物，及其醯亞胺化物之聚醯亞胺所成群之至少1種。

(式(6)中，X₁ 表示源自四羧酸衍生物之4價有機基。Y₁ 表示源自包含式(1)之構造之二胺之2價有機基。R₄ 表示氫原子或碳數1～5之烷基。) (5)如請求項4之液晶配向劑，其中前述式(6)中，X₁ 之構造為選自後述之式(A-1)～(A-21)之構造之至少1種。 (6)如上述(4)或(5)之液晶配向劑，其中相對於前述聚合物之全部構造單位，前述式(6)所示之構造單位為10莫耳%以上。 (7)一種液晶配向膜，其係由如上述(1)～(6)中任一項之液晶配向劑所得。 (8)一種液晶顯示元件，其係具備如上述(7)之液晶配向膜。 (9)一種二胺，其係具有如下述式(2-1)、(2-2)或(2-3)所示之噁唑啉骨架。

(各記號之定義係如後述所示。) (10)一種聚合物，其係具有源自如上述(9)之二胺之噁唑啉骨架。 (11)如上述(10)之聚合物，其中前述具有噁唑啉骨架之聚合物為包含下述式(6)所示之構造單位之聚醯亞胺前驅物，及其醯亞胺化物之聚醯亞胺。

(式(6)中之各記號之定義係與上述(4)中之記載相同。) (12)如上述(11)之聚合物，其中前述式(6)中，X₁ 之構造為選自後述之式(A-1)～(A-21)之構造之至少1種。 (13)如上述(11)或(12)之聚合物，其中相對於前述聚合物之全部構造單位，前述式(6)所示之構造單位為10莫耳%以上。 [發明之效果]As a result of intensive studies by the present inventors in order to solve the above-mentioned problems, the present invention has the following aspects. (1) A liquid crystal alignment agent characterized by containing: a polymer having an oxazoline skeleton represented by the following formula (1).

(R ¹ represents hydrogen or a monovalent organic group, and * represents a bonding site with other groups.) (2) The liquid crystal alignment agent as described in (1) above, wherein the oxazoline skeleton represented by the above formula (1) is the source from diamines. (3) The liquid crystal alignment agent as in the above (1), wherein the polymer having the oxazoline skeleton represented by the aforementioned formula (1) is derived from the following formula (2-1), (2-2) and (2-4) Polymer of diamine. (4) The liquid crystal alignment agent as in the above (1), wherein the polymer having the aforementioned oxazoline skeleton is derived from a polyimide precursor comprising a structural unit represented by the following formula (6), and its imide At least one type of polyimide group of aminated compounds.

(In formula (6), X ₁ represents a 4-valent organic group derived from a tetracarboxylic acid derivative. Y ₁ represents a divalent organic group derived from a diamine comprising a structure of formula (1). R ₄ represents a hydrogen atom or An alkyl group with 1 to 5 carbon atoms.) (5) The liquid crystal alignment agent according to claim 4, wherein in the aforementioned formula (6), the structure of _X1 is selected from the following formulas (A-1) to (A-21 ) of at least one structure. (6) The liquid crystal alignment agent according to (4) or (5) above, wherein the structural unit represented by the aforementioned formula (6) is 10 mol% or more relative to all structural units of the aforementioned polymer. (7) A liquid crystal alignment film obtained from the liquid crystal alignment agent according to any one of the above (1) to (6). (8) A liquid crystal display element comprising the liquid crystal alignment film as described in (7) above. (9) A diamine having an oxazoline skeleton represented by the following formula (2-1), (2-2) or (2-3).

(Definitions of each symbol are as follows.) (10) A polymer having an oxazoline skeleton derived from the diamine as described in (9) above. (11) The polymer as in the above (10), wherein the aforementioned polymer having an oxazoline skeleton is a polyimide precursor comprising a structural unit represented by the following formula (6), and an imide compound thereof Polyimide.

(The definition of each symbol in the formula (6) is the same as that described in the above (4).) (12) The polymer as in the above (11), wherein in the above formula (6), the structure of _X1 is selected from At least one structure of formulas (A-1) to (A-21) described below. (13) The polymer according to (11) or (12) above, wherein the structural unit represented by the aforementioned formula (6) is 10 mol% or more relative to all structural units of the aforementioned polymer. [Effect of Invention]

According to the present invention, it is possible to obtain a liquid crystal alignment film with improved rubbing resistance and voltage retention characteristics, good aging resistance under high temperature and high humidity conditions, and excellent adhesion with a sealant. In other words, by using a polymer with an oxazoline skeleton as a component of the liquid crystal alignment agent, it is difficult to cause peeling or damage of the film during friction, and the voltage retention rate and high temperature and high humidity aging resistance are high. Liquid crystal alignment film with excellent adhesiveness of sealant. The liquid crystal display element equipped with the liquid crystal alignment film obtained by the liquid crystal alignment agent of the present invention has few display defects due to damage or scratches of the liquid crystal alignment film, has high reliability, and has excellent adhesion to the sealant. element.

上述式(1)中，R¹ 表示氫、或一價有機基，＊表示與其他基之鍵結部位。本發明中之特定聚合物係以由具有上述式(1)之構造之二胺所得之聚合物為佳。The liquid crystal alignment agent of the present invention is a liquid crystal alignment agent containing: a polymer having a structure represented by the following formula (1) (hereinafter also referred to as a specific polymer). ＜specific structure＞

In the above formula (1), R ¹ represents hydrogen or a monovalent organic group, and * represents a bonding site with other groups. The specific polymer in the present invention is preferably a polymer obtained from a diamine having the structure of the above formula (1).

＜Specific diamines＞ Examples of diamines having an oxazoline skeleton represented by the above formula (1) (hereinafter also referred to as specific diamines) include those selected from the group represented by the following formulas (2-1) to (2-3). of diamines.

In the above formula (2-1) to formula (2-3), the definition of R ¹ is the same as that described in the above formula (1). R ² is selected from single bond, -O-, -COO-, -OCO-, -(CH ₂ ) _l -, -O(CH ₂ ) _l O-, -CONR ¹¹ -, -NR ¹¹ CO- and - A bond of NR ¹¹ -, or a divalent organic group composed of these combinations, W ¹ represents a structure selected from the following group (3-1), W ² represents a structure selected from the following group (3-2) W ³ represents a structure selected from the following group (3-3), and W ⁴ represents a structure selected from the following group (3-4). Here, R ¹¹ represents hydrogen or a monovalent organic group, l represents an integer of 1-12, and a represents an integer of 0 or 1.

In the above-mentioned group (3-1), * ₁ represents the site bonded to the amino group in formulas (2-1) to (2-3), and * ₂ represents the site bonded to the oxazoline ring. In the group (3-2), * ₁ represents the site bonded to the amine group in formulas (2-1) to (2-3), and * ₃ represents the site bonded to R ² . In the group (3-3), * ₃ represents a bonding site to R ² . In the group (3-4), * ₂ represents a bonding site to the oxazoline ring. X represents a substituent, a hydrogen atom; a halogen atom; an alkyl group with 1 to 6 carbons such as methyl, ethyl, and propyl; a halogenated alkyl group with 1 to 6 carbons such as trifluoromethyl; dimethylamine Substituted amino groups such as methoxy and ethoxy groups; alkoxy groups with 1 to 6 carbon atoms such as methoxy and ethoxy groups; amido groups such as NHCOCH ₃ or NHCOCH ₂ CH ₃ , NHCOOtBu, etc. tBu represents the tertiary butyl group.

Specific examples of the diamines of the above formulas (2-1) to (2-3) are illustrated below.

In the above formula, the definition of R ¹ is the same as that described in the above formula (1), especially a hydrogen atom, a methyl group (Me) or an ethyl group (Et). The definition of R ¹¹ is the same as that described in the above formula (1), especially hydrogen atom, Me group or Et group is preferred. n represents an integer of 1-6, and m represents an integer of 1-12.

上述式(4-1)～(4-3)中，R¹ 、R² 、W¹ 、W² 、W³ 、W⁴ 及a之定義係與上述式(2-1)～(2-3)中記載者相同。<Synthesis method of specific diamine> The method for synthesizing the specific diamine of the present invention includes, for example, synthesizing dinitro compounds represented by the following formulas (4-1) to (4-3), and then adding nitro A method of converting it into an amine group by reduction.

In the above formulas (4-1) to (4-3), the definitions of R ¹ , R ² , W ¹ , W ² , W ³ , W ⁴ and a are the same as those in the above formulas (2-1) to (2-3) ) are the same.

The catalyst used for the reduction reaction of the nitro group is preferably a commercially available metal supported on activated carbon, for example, palladium-activated carbon, platinum-activated carbon, rhodium-activated carbon and the like. Also, palladium hydroxide, platinum oxide, Raney nickel, etc. do not need to be activated carbon-supported metal catalysts. Among them, palladium-activated carbon is preferred.

In order to make the reduction reaction described above proceed more efficiently, the reaction may be carried out in the coexistence of activated carbon. At this time, the amount of activated carbon to be used is preferably 1 to 30% by mass, more preferably 10 to 20% by mass relative to the dinitro compound. For the same reason, the reaction may be carried out under pressure. In this case, in order to avoid the reduction of benzene nuclei, it is preferable to carry out the reaction under 20 atmospheres, more preferably up to 10 atmospheres.

The solvent in the above reduction reaction can be used without limitation as long as it does not react with each raw material. For example, aprotic polar organic solvents (DMF, DMSO, DMAc, NMP, etc.); ethers (Et ₂ O, i-Pr ₂ O, TBME, CPME, THF, dioxane, etc.); aliphatic hydrocarbons can be used (pentane, hexane, heptane, petroleum ether, etc.); aromatic hydrocarbons (benzene, toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene, nitrobenzene, tetrahydronaphthalene, etc.); halogen series Hydrocarbons (chloroform, dichloromethane, carbon tetrachloride, dichloroethane, etc.); lower fatty acid esters (methyl acetate, ethyl acetate, butyl acetate, methyl propionate, etc.); nitriles (acetonitrile, propionitrile, butyronitrile, etc.), etc. These solvents may be appropriately selected in consideration of the easiness of inducing a reaction, and may be used in combination of two or more. If necessary, a suitable dehydrating agent or desiccant can also be used to dry the solvent and use it as a non-aqueous solvent. The usage amount (reaction concentration) of the solvent is 0.1 to 100 times by mass, preferably 0.5 to 30 times by mass, more preferably 1 to 10 times by mass relative to the dinitro compound. The reaction temperature ranges from -100°C to the boiling point of the solvent used, preferably -50 to 150°C. The reaction time is usually 0.05 to 350 hours, preferably 0.5 to 100 hours.

[Methods for preparing dinitro compounds of formula (4-1), formula (4-3)] The method of synthesizing the compounds of formula (4-1) and (4-3) is as shown in the following reaction formula, by (4-1-1) or (4-3-1) can be obtained by reacting the compound represented by formula (5-1) or (5-2) with halonitrobenzene in the presence of a base.

The above reaction is preferably carried out in the presence of a base. As the base, for example, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal carbonates such as sodium carbonate and potassium carbonate, alkali metal bicarbonates such as sodium hydrogencarbonate and potassium hydrogencarbonate, potassium phosphate , 1,8-diacribicyclo[5,4,0]-7-undecene or organic bases such as triethylamine, etc., preferably relative to (5-1) or (5-2) 1 to 4 equivalents are used.

As the reaction solvent, an aprotic polar organic solvent (DMF, DMSO, DMAc, NMP, etc.) is preferable. The usage amount (reaction concentration) of the solvent is preferably 0.1 to 100 times by mass, more preferably 0.5 to 30 times by mass relative to (5-1) or (5-2). The reaction temperature is preferably in the range from -10°C to the boiling point of the solvent used, preferably 0 to 150°C. The reaction time is usually 0.05 to 350 hours, preferably 0.5 to 100 hours.

As another method for producing the above-mentioned dinitro compounds, (5-1-1a) or (5 - After 2-1a), the formula (4-1-2) or (4-3-2) can be obtained by reacting it with a phenol compound or an amine compound in the presence of a base.

The above-mentioned leaving group (LG) can be reacted with methanesulfonyl chloride, ethanesulfonyl chloride, or p-toluenesulfonyl chloride in the presence of a base such as triethylamine or pyridine. import.

The reaction of (5-1-1a) or (5-2-1a) with a phenolic compound or an amine compound is preferably carried out in the presence of a base. As the base, for example, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal carbonates such as sodium carbonate and potassium carbonate can be used relative to (5-1-1a) or (5-2-1a ) using 1 to 4 equivalents.

(4-1-2) or (4 -3-3).

[Method for producing formula (4-2)] The method for synthesizing the compound of formula (4-2) is not particularly limited. For example, as shown in the following reaction formula, (4-2-1) can be obtained by reacting a compound represented by formula (5-1) with an acid chloride in the presence of a base such as triethylamine or pyridine. or (4-2-2).

[Methods for preparing formulas (5-1) and (5-2)] The methods for synthesizing formulas (5-1) and (5-2) are not particularly limited. For example, the reference (J. Org. Chem. 2014, 79, 8668-8677) can be obtained by reacting a cyano compound with an aminoethanol compound in the presence of a base as shown in the following reaction formula (5-1 -1) or (5-2-1).

The above reaction is preferably carried out in the presence of a base. As the base, for example, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal carbonates such as sodium carbonate and potassium carbonate, inorganic compounds such as sodium phosphate and potassium phosphate, 1,8-diazene bicyclo Organic bases such as [5,4,0]-7-undecene and the like are used in an amount of 1 to 4 equivalents to the cyano compound. Among them, alkali metal carbonates such as sodium carbonate and potassium carbonate are preferred.

As the reaction solvent, for example, aprotic polar organic solvents (DMF, DMSO, DMAc, NMP, etc.); ethers (Et ₂ O, i-Pr ₂ O, TBME, CPME, THF, dioxane, etc.); aliphatic Aromatic hydrocarbons (pentane, hexane, heptane, petroleum ether, etc.); Aromatic hydrocarbons (benzene, toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene, nitrobenzene, tetrahydronaphthalene, etc.) ; Halogenated hydrocarbons (chloroform, methylene chloride, carbon tetrachloride, ethylene dichloride, etc.); lower fatty acid esters (methyl acetate, ethyl acetate, butyl acetate, methyl propionate, etc.); nitriles (acetonitrile, propionitrile, butyronitrile, etc.); alcohols (methanol, ethanol, 2-propanol, etc.), etc. These solvents can be appropriately selected in consideration of the easiness of causing the reaction, and may be used alone or in combination of two or more. If necessary, a suitable dehydrating agent or desiccant can also be used to dry the solvent and use it as a non-aqueous solvent. In particular, alcohols (methanol, ethanol, 2-propanol, etc.) are preferred.

After making the following (5-1-1a) or (5-2-1a) react with phthalimide potassium (Phthalimide potassium) to obtain (5-1-1b) or (5-2-1b), by Deprotection using hydrazine monohydrate affords (5-1-2) or (5-2-2). Also, (5-1-3) or (5-2-3) can be obtained by reacting an excess amount of the secondary amine compound with (5-1-1a) or (5-2-1a).

Also, in the formulas of the manufacturing process so far, the definitions of R ¹ , W ¹ , W ² , W ³ , and W ⁴ are the same as those in the above formulas (2-1) to (2-3), but R ¹ It is preferably a hydrogen atom or a Me group or an Et group. Y represents OH, NH ₂ or NHR ¹¹ , Y ¹ represents O, NH or NR ¹¹ , the definition of R ¹¹ is the same as that in the above formula (1), but hydrogen atom, Me group and Et group are preferred. Z represents F, Cl, Br, I, n represents an integer of 1-6, and m represents an integer of 1-12.

上述式(6)中，X₁ 為源自四羧酸衍生物之4價有機基，Y₁ 為源自包含式(1)之構造之二胺之2價有機基，R₄ 為氫原子或碳數1～5之烷基。R₄ 在從由加熱所成之醯亞胺化之容易度之觀點，以氫原子、甲基或乙基為佳。<Polymer> The polymer having an oxazoline skeleton of the present invention has a structure represented by the above formula (1). Specific examples include polyamic acid, polyamic acid ester, polyimide, polyurea, and polyamide. From the viewpoint of being used as a liquid crystal alignment agent, at least one selected from a polyimide precursor containing a structural unit represented by the following formula (6) and a polyimide of the imide compound is preferred. .

In the above formula (6), X ₁ is a quaternary organic group derived from a tetracarboxylic acid derivative, Y ₁ is a divalent organic group derived from a diamine comprising the structure of formula (1), R ₄ is a hydrogen atom or An alkyl group with 1 to 5 carbon atoms. R ₄ is preferably a hydrogen atom, a methyl group or an ethyl group from the viewpoint of easiness of imidization by heating.

<Tetracarboxylic dianhydride> _X1 in the polyimide precursor of the above formula (6) can be used in accordance with the solubility of the polymer to the solvent or the coating property of the liquid crystal alignment agent, and the liquid crystal when it is made into a liquid crystal alignment film. Alignment, voltage retention, charge storage, and other necessary characteristics are appropriately selected, and one type may be used in the same polymer, or two or more types may be mixed. Specific examples of _X1 include the structures of formulas (X-1) to (X-46) disclosed in Items 13 to 14 of International Publication No. 2015/119168.

The structure of the preferred _X1 is shown below.

Among the above, (A-1) and (A-2) are particularly preferable from the viewpoint of further improving the friction resistance, and (A-4) is particularly preferable from the viewpoint of further improving the relaxation speed of accumulated electric charges. From the viewpoint of alignment and relaxation speed of accumulated charge, (A-15) to (A-17) and the like are particularly preferable. Also, among the above, (A-1), (A-4), (A-5), and (A-7) are preferable from the viewpoint of further improving the voltage retention ratio.

<Diamine> In the above formula (6), specific examples of Y ₁ include removing two amino groups from the diamine of the above formula (2-1), (2-2) or (2-3). subsequent structure.

式(7)中，X₂ 為源自四羧酸衍生物之4價有機基，Y₂ 為源自不包含式(1)之構造之二胺之2價有機基，R₄ 係與前述式(6)之定義相同，R₅ 表示氫原子或碳數1～4之烷基。又，2個R₄ 之至少一者係以氫原子為佳。<Polymer (other structural unit)> The polyimide precursor containing the structural unit represented by the formula (6) may also contain the structure represented by the following formula (7) within the scope not to impair the effect of the present invention unit.

In formula (7), X ₂ is a quaternary organic group derived from tetracarboxylic acid derivatives, Y ₂ is a divalent organic group derived from a diamine that does not contain the structure of formula (1), R ₄ is the same as the aforementioned formula The definition of (6) is the same, and R ₅ represents a hydrogen atom or an alkyl group having 1 to 4 carbons. Also, at least one of the two R ₄ is preferably a hydrogen atom.

Specific examples of _X2 , including preferred examples, include the same structures as those exemplified for _X1 in formula (6). In addition, Y ₂ in the polyimide precursor is a divalent organic group derived from a diamine that does not contain the structure of formula (1), and its structure is not particularly limited. In addition, _Y2 can be appropriately selected according to the solubility of the polymer to the solvent or the coating property of the liquid crystal alignment agent, the alignment of the liquid crystal when the liquid crystal alignment film is made, the voltage retention rate, and the accumulated charge. Two or more types may be mixed in the same polymer.

If a specific example of _Y2 is illustrated, the structure of formula (2) disclosed in item 4 of International Publication No. 2015/119168, and the formulas (Y-1)～( The structure of Y-97), (Y-101)～(Y-118); the divalent organic group after removing two amine groups from formula (2) disclosed in item 6 of International Publication 2013/008906; from The structure of formula (3) disclosed in item 8 of International Publication 2015/122413 after removing two amine groups from formula (1) disclosed in International Publication 2015/122413; the structure of formula (3) disclosed in International Publication 2015/060360; The divalent organic group obtained by removing two amine groups from the formula (1) described in Item 8 of the Publication No. 2012-173514; the formula (A)-(F) disclosed in Item 9 of the International Publication No. 2010-050523 removes 2 A divalent organic group after an amine group, etc.

<Other diamines> In addition to the above-mentioned diamine components, the diamine components shown below can also be used as other diamines. <Other diamine: the diamine which has the structure of formula (0)> Other diamine has the structure of following formula (0).

In the above formula (0), A ¹ and A ⁵ each independently represent a single bond or an alkylene group having 1 to 5 carbon atoms. From the viewpoint of reactivity with the functional group in the sealing material for laminating the upper and lower substrates, a single bond or a methylene group is preferable.

Also, in the above formula (0), A ² and A ⁴ each independently represent an alkylene group having 1 to 5 carbon atoms, preferably a methylene group or an ethylene group. A ³ represents an alkylene or cycloalkylene group having 1 to 6 carbon atoms, preferably a methylene group or an ethylene group from the viewpoint of reactivity with functional groups in the sealing material.

In addition, in the above formula (0), B ¹ and B ² each independently represent a single bond, -O-, -NH-, -N(CH ₃ )-, -CO-, -COO-, -OCO-, - CONH-, -NHCO-, -CON( _CH3 )- or -N( _CH3 )CO. From the viewpoint of the alignment of the obtained liquid crystal alignment film, a single bond or -O- is preferable.

Also, in the above formula (0), D ₁ represents a protecting group substituted with a hydrogen atom due to heat. _D1 is a functional group that functions as a protecting group for an amine group, and is a functional group that is substituted with a hydrogen atom due to heat. From the perspective of storage stability of the liquid crystal alignment agent, _D1 is preferably a protecting group that will not detach at room temperature, and is preferably a protecting group that detaches due to heat above 80°C, especially when it is above 120°C. The protective group detached from the above heat is even more. The detachment temperature is preferably below 250°C, more preferably below 230°C. Excessively high release temperature may lead to the possibility of polymer decomposition. Examples of such _D1 include tert-butoxycarbonyl (t-Boc) group, 9-tertilylmethoxycarbonyl group and the like. Among them, the t-Boc group is preferable from the viewpoint of detachability due to temperature.

In addition, in the above formula (0), a is 0 or 1. A ² and A ³ (when a is 1), A ³ and A ⁴ (when a is 1), or A ² and A ⁴ (when a is 0) do not combine with each other. That is, when a is 1, a ring will not be formed by A ² and A ³ , A ³ and A ⁴ , and the N atom bonded to D ₁ will not constitute a part of the ring. Similarly, when a is 0, a ring will not be formed by ^A2 and ^A4 , and the N atom bonded to _D1 will not constitute a part of the ring.

上述式(0’)及上述式(0”)中，A¹ ～A⁵ 、B¹ 、B² 、D₁ 、a以及＊係與上述式(0)之情況相同。Moreover, in said formula (0), * represents the bonding site with another group. From the perspective of *, the bonding position of ^A1 and/or ^A5 relative to the benzene ring can be any of the ortho, meta, and para positions, but from the perspective of the liquid crystal alignment of the liquid crystal alignment film, Counterpoint is good. That is, the above-mentioned formula (0) is preferably the following formula (0') or the following formula (0").

In the above formula (0') and the above formula (0"), A ¹ to A ⁵ , B ¹ , B ² , D ₁ , a, and * are the same as those in the above formula (0).

As a specific example of such specific diamine, the diamine shown by following formula (0-1)-(0-21), for example is mentioned.

＜Other diamines: Diamines having a specific side chain structure exhibiting vertical alignment＞ When using a liquid crystal alignment agent in a VA-type liquid crystal display element, it is preferable to prepare a specific polymer using a diamine having a specific side chain structure exhibiting vertical alignment capability. This diamine having a specific side chain structure has at least one side chain structure selected from the group represented by the following formulas [S1] to [S3]. Hereinafter, the example about the diamine which has this specific side chain structure, ie, the diamine represented by formula [S1]-[S3] is demonstrated sequentially.

上述式[S1]中，X¹ 及X² 係各自獨立表示單鍵、-(CH₂ )_a -(a為1～15之整數)、-CONH-、-NHCO-、-CON(CH₃ )-、 -NH-、-O-、-COO-、-OCO-或-((CH₂ )_a1 -A₁ )_m1 -。其中，複數之a1係各自獨立為1～15之整數，複數之A₁ 係各自獨立表示氧原子或-COO-，m1為1～2。[A]: Diamine having a specific side chain structure represented by the following formula [S1]

In the above formula [S1], X ¹ and X ² each independently represent a single bond, -(CH ₂ ) _a - (a is an integer from 1 to 15), -CONH-, -NHCO-, -CON(CH ₃ ) -, -NH-, -O-, -COO-, -OCO-, or -((CH ₂ ) _a1 -A ₁ ) _m1 -. Among them, a1 in plural is independently an integer of 1-15, _A1 in plural is independently an oxygen atom or -COO-, and m1 is 1-2.

Among them, from the viewpoint of availability of raw materials or ease of synthesis, X ¹ and X ² are each independently a single bond, -(CH ₂ ) _a - (a is an integer of 1 to 15), -O-, -CH ₂ O- or -COO- is preferred, and a single bond, -(CH ₂ ) _a - (a is an integer of 1 to 10), -O-, -CH ₂ O- or -COO- is preferred.

Also, in the above formula [S1], ^G1 and ^G2 each independently represent a divalent cyclic group selected from a divalent aromatic group having 6 to 12 carbons or a divalent alicyclic group having 3 to 8 carbons. . Any hydrogen atom on the cyclic group can be replaced by an alkyl group with 1 to 3 carbons, an alkoxy group with 1 to 3 carbons, a fluorine-containing alkyl group with 1 to 3 carbons, or a fluoroalkane with 1 to 3 carbons. Oxygen or fluorine atoms are substituted. m and n are each independently an integer of 0-3, and the total of m and n is 1-4.

In addition, in the above formula [S1], R ¹ represents an alkyl group having 1 to 20 carbons, an alkoxy group having 1 to 20 carbons, or an alkoxyalkyl group having 2 to 20 carbons. Any hydrogen forming ^R1 may also be replaced by fluorine. Among these, examples of divalent aromatic groups having 6 to 12 carbon atoms include phenylene, biphenylene, and naphthalene. Moreover, examples of the divalent alicyclic group having 3 to 8 carbon atoms include a cyclopropyl group, a cyclohexylene group, and the like.

Therefore, as a preferable specific example of said formula [S1], following formula [S1-x1]-[S1-x7] can be mentioned.

In the above formulas [S1-x1] to [S1-x7], R ¹ is the same as in the case of the above formula [S1]. X ^p represents -(CH ₂ ) _a - (a is an integer from 1 to 15), -CONH-, -NHCO-, -CON(CH ₃ )-, -NH-, -O-, -CH ₂ O-, -COO- or -OCO-. A ₁ represents an oxygen atom or -COO-* (the bond with "*" is bonded to (CH ₂ ) _a2 ). A ₂ represents an oxygen atom or *-COO- (the bond with "*" is bonded with (CH ₂ ) _a2 ). a ₁ is an integer of 0 or 1, and a ₂ is an integer of 2-10. Cy represents 1,4-cyclohexylene or 1,4-phenylene.

上述式[S2]中，X³ 表示單鍵、-CONH-、-NHCO-、 -CON(CH₃ )-、-NH-、-O-、-CH₂ O-、-COO-或-OCO-。其中，從液晶配向劑之液晶配向性之觀點，X³ 係以-CONH-、 -NHCO-、-O-、-CH₂ O-、-COO-或-OCO-為佳。[B]: Diamine having a specific side chain structure represented by the following formula [S2]

In the above formula [S2], X ³ represents a single bond, -CONH-, -NHCO-, -CON(CH ₃ )-, -NH-, -O-, -CH ₂ O-, -COO- or -OCO- . Among them, from the viewpoint of the liquid crystal alignment of the liquid crystal alignment agent, X ³ is preferably -CONH-, -NHCO-, -O-, -CH ₂ O-, -COO- or -OCO-.

Also, in the above formula [S2], R ² represents an alkyl group having 1 to 20 carbons or an alkoxyalkyl group having 2 to 20 carbons. Any hydrogens forming ^R2 may also be substituted with fluorine. Among them, from the viewpoint of liquid crystal alignment of the liquid crystal alignment agent, R ² is preferably an alkyl group with 3 to 20 carbons or an alkoxyalkyl group with 2 to 20 carbons.

上述式[S3]中，X⁴ 表示-CONH-、-NHCO-、-O-、 -COO-或-OCO-。R³ 表示具有類固醇骨架之構造。在此之類固醇骨架係具有3個六員環及1個五員環結合而成之下述式(st)所示之骨架。

[C]: Diamine having a specific side chain structure represented by the following formula [S3]

In the above formula [S3], X ⁴ represents -CONH-, -NHCO-, -O-, -COO- or -OCO-. R ³ represents a structure having a steroid skeleton. The steroid skeleton here has a skeleton represented by the following formula (st) in which three six-membered rings and one five-membered ring are combined.

As an example of said formula [S3], following formula [S3-x] is mentioned.

In said formula [S3-x], X represents said formula [X1] or [X2]. Moreover, Col represents at least 1 sort(s) selected from the group which consists of said formula [Col1]-[Col4], and G represents said formula [G1] or [G2]. *Indicates the bonding site with other groups.

As an example of the preferable combination of X, Col, and G in said formula [S3-x], the following combination is mentioned, for example. That is, [X1] and [Col1] and [G1], [X1] and [Col1] and [G2], [X1] and [Col2] and [G1], [X1] and [Col2] and [G2], [X1] and [Col3] and [G2], [X1] and [Col4] and [G2], [X1] and [Col3] and [G1], [X1] and [Col4] and [G1], [X2] ] and [Col1] and [G2], [X2] and [Col2] and [G2], [X2] and [Col2] and [G1], [X2] and [Col3] and [G2], [X2] and [Col4] and [G2], [X2] and [Col1] and [G1], [X2] and [Col4] and [G1].

Also, as a specific example of the above-mentioned formula [S3], a structure in which a hydroxyl group (hydroxyl group) has been removed from a steroid compound as described in paragraph [0024] of JP-A-4-281427, from paragraph [0030] of the same publication The structure of the steroid compound described in ] after removing the acid chlorine group, the structure after removing the amino group from the steroid compound described in paragraph [0038] of the same publication, and the structure after removing the halogen group from the steroid compound described in paragraph [0042] of the same publication , and the structures described in paragraphs [0018] to [0022] of Japanese Patent Application Laid-Open No. 8-146421, etc.

Furthermore, as a representative example of the steroid skeleton, cholesterol (combination of [Col1] and [G2] in the above formula [S3-x]) is mentioned, but a steroid skeleton not including this cholesterol can also be used. That is, examples of the diamine having a steroid skeleton include cholesteryl 3,5-diaminobenzoate and the like, but diamine components that do not contain the diamine having the cholesterol skeleton can also be used. Moreover, as a diamine which has a specific side chain structure, the thing which does not contain an amide can also be utilized in the linking position of a diamine and a side chain. Even if such a diamine is used, in this embodiment, even if a diamine component that does not contain a diamine having a cholesterol skeleton is used, it is possible to provide a liquid crystal alignment film or a liquid crystal display that can secure a high voltage retention rate over a long period of time. Liquid crystal alignment agent for components.

上述式[1-S1]中，X¹ 、X² 、G¹ 、G² 、R¹ 、m及n係與上述式[S1]中之情況相同。上述式[1-S2]中，X³ 及R² 係與上述式[S2]中之情況相同。上述式[1-S3]中，X⁴ 及R³ 係與上述式[S3]中之情況相同。Furthermore, diamines having a side chain structure represented by the above formulas [S1] to [S3] are represented by structures of the following formulas [1-S1] to [1-S3], respectively.

In the above formula [1-S1], X ¹ , X ² , G ¹ , G ² , R ¹ , m and n are the same as those in the above formula [S1]. In the above formula [1-S2], X ³ and R ² are the same as those in the above formula [S2]. In the above formula [1-S3], X ⁴ and R ³ are the same as those in the above formula [S3].

<Other diamines: diamines having a characteristic side chain structure of a double side chain type exhibiting vertical alignment> When using as a liquid crystal alignment agent in a VA liquid crystal display element, one having two vertical alignment properties can also be used Two side chain type diamines with specific side chain structure can be used to prepare specific polymers. The two side chain diamine which can be contained as this diamine component is represented by following formula [1], for example.

In the above formula [1], X represents a single bond, -O-, -C(CH ₃ ) ₂ -, -NH-, -CO-, -NHCO-, -COO-, -(CH ₂ ) _m -, - SO ₂ -or a divalent organic group formed by any combination of these. Among them, X is preferably a single bond, -O-, -NH-, -O-(CH ₂ ) _m -O-. Examples of "any combination of these" include -O-(CH ₂ ) _m -O-, -OC(CH ₃ ) ₂ -, -CO-(CH ₂ ) _m -, -NH-( CH ₂ ) _m -, -SO ₂ -(CH ₂ ) _m -, -CONH-(CH ₂ ) _m -, -CONH-(CH ₂ ) _m -NHCO-, -COO-(CH ₂ ) _m -OCO- wait. m is an integer of 1-8. Moreover, in the said formula [1], two Ys represent the structure of following formula [1-1] each independently.

In the above formula [1-1], Y ¹ and Y ³ each independently represent a single bond, -(CH ₂ ) _a - (a is an integer from 1 to 15), -O-, -CH ₂ O-, -COO -or-OCO-. Y ² represents a single bond or -(CH ₂ ) _b - (b is an integer of 1 to 15). However, when Y ¹ or Y ³ is a single bond or -(CH ₂ ) _a -, Y ² is a single bond. Also, when Y ¹ is -O-, -CH ₂ O-, -COO- or -OCO-, and/or Y ³ is -O-, -CH ₂ O-, -COO- or -OCO-, Y ² is a single bond or -(CH ₂ ) _b -. In addition, in the formula [1-1], Y ⁴ represents at least one divalent cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring, and a heterocycle, or 2 of 17 to 51 carbons having a steroid skeleton. Valence organic base. Any hydrogen atom forming the cyclic group can also be replaced by an alkyl group with 1 to 3 carbons, an alkoxy group with 1 to 3 carbons, a fluorine-containing alkyl group with 1 to 3 carbons, or a fluorine-containing alkyl group with 1 to 3 carbons. substituted by fluoroalkoxy or fluorine atoms.

In addition, in the above formula [1-1], Y ⁵ represents at least one cyclic group selected from the group consisting of a benzene ring, a cyclohexane ring, and a heterocycle. Any hydrogen atom forming the cyclic group can also be replaced by an alkyl group with 1 to 3 carbons, an alkoxy group with 1 to 3 carbons, a fluorine-containing alkyl group with 1 to 3 carbons, or a fluorine-containing alkyl group with 1 to 3 carbons. substituted by fluoroalkoxy or fluorine atoms. In addition, in the above formula [1-1], Y ⁶ represents an alkyl group selected from an alkyl group having 1 to 18 carbons, an alkenyl group having 2 to 18 carbons, a fluorine-containing alkyl group having 1 to 18 carbons, an alkyl group having 1 to 18 carbons at least one of the group consisting of an alkoxy group having 1 to 18 carbon atoms and a fluorine-containing alkoxy group. n is an integer of 0-4.

Also, in the above formula [1], Y can be in the meta position or in the ortho position when viewed from the position of X, preferably in the ortho position. That is, the above-mentioned formula [1] is preferably the following formula [1'].

Also, in the above formula [1], the positions of the two amino groups (-NH ₂ ) can be any position on the benzene ring, and the positions shown in the following formulas [1]-a1 to [1]-a3 are preferred , the following formula [1]-a1 is preferred. In the following formula, X is the same as in the above formula [1]. Furthermore, the following formulas [1]-a1 to [1]-a3 are for explaining the positions of two amino groups, so the symbol of Y shown in the above-mentioned formula [1] is omitted.

Therefore, if based on the above-mentioned formula [1'] and [1]-a1～[1]-a3, the above-mentioned formula [1] is selected from the following formulas [1]-a1-1～[1]-a3-2 Any one of the structures is preferable, and the structure represented by the following formula [1]-a1-1 is more preferable. In the following formula, X and Y are respectively the same as those in the formula [1].

Moreover, as an example of said formula [1-1], following formula [1-1]-1-[1-1]-22 is mentioned. Among them, the following formulas [1-1]-1 to [1-1]-4, [1-1]-8, or [1-1]-10 are preferable as examples of the formula [1-1]. In addition, in the following formula, * represents the bonding position with the phenyl group in said formula [1], [1'] and [1]-a1-[1]-a3.

The diamine component contains diamines having two side chains having a predetermined structure, thereby forming a liquid crystal alignment film in which the ability to vertically align liquid crystals does not easily decrease even when overheated. Moreover, when a diamine component contains this diamine of two side chains, even if a film contacts with any foreign matter and is damaged, it becomes a liquid crystal alignment film which does not reduce the vertical alignment ability of a liquid crystal so easily. That is, a diamine component can provide the liquid crystal aligning agent which can acquire the liquid crystal aligning film excellent in various said characteristics by containing this diamine of two side chains.

＜Other diamines: diamines with photoreactive side chains＞ When using it as a liquid crystal alignment agent in a PSA type liquid crystal display element, for the purpose of improving the reactivity of a polymerizable compound, a specific polymer may be prepared using a diamine having a photoreactive side chain. This diamine component may contain the diamine which has a photoreactive side chain as another diamine. The diamine component can introduce a photoreactive side chain into a specific polymer or other polymers by containing the diamine which has a photoreactive side chain.

As a diamine which has a photoreactive side chain, what is represented by following formula [VIII] or [IX] is mentioned, for example.

In the above formulas [VIII] and [IX], the positions of the two amino groups (-NH ₂ ) can be any position on the benzene ring, for example, with respect to the bonding group of the side chain, on the benzene ring The 2,3 position, 2,4 position, 2,5 position, 2,6 position, 3,4 position or 3,5 position. The 2,4 position, the 2,5 position, or the 3,5 position are preferable from the viewpoint of the reactivity at the time of polyamide acid synthesis. From the viewpoint of the ease of synthesizing diamine, the 2,4 position or the 3,5 position is preferable.

In addition, in the above formula [VIII], R ⁸ represents a single bond, -CH ₂ -, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O-, -N(CH ₃ )-, -CON(CH ₃ )- or -N(CH ₃ )CO-. In particular, R ⁸ is preferably a single bond, -O-, -COO-, -NHCO- or -CONH-.

Also, in the above formula [VIII], R ⁹ represents a single bond or an alkylene group having 1 to 20 carbon atoms which may be substituted by a fluorine atom. The -CH ₂ - of the alkylene group here can be optionally substituted by -CF ₂ - or -CH=CH-, and when it is not adjacent to any of the following groups, it can also be replaced by these groups Substituted; -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, divalent carbocycle or heterocycle. Furthermore, the divalent carbocyclic or heterocyclic ring system can specifically be exemplified by the following formula (1a).

Also, in the above formula [VIII], R ⁹ can be formed by common organic synthesis techniques, and from the viewpoint of ease of synthesis, a single bond or an alkylene group having 1 to 12 carbons is preferable.

In addition, in the above-mentioned formula [VIII], R ¹⁰ represents a photoreactive group selected from the group consisting of the following formula (1b). Among them, R ¹⁰ is preferably methacryl, acryl or vinyl from the viewpoint of photoreactivity.

In addition, in the above formula [IX], Y ₁ represents -CH ₂ -, -O-, -CONH-, -NHCO-, -COO-, -OCO-, -NH- or -CO-. Y ₂ represents an alkylene group having 1 to 30 carbon atoms, a divalent carbocyclic ring or a heterocyclic ring. One or more hydrogen atoms in the alkylene group, divalent carbocyclic ring or heterocyclic ring may be substituted by fluorine atoms or organic groups. When Y ₂ is not adjacent to each other, -CH ₂ - can also be substituted by these groups; -O-, -NHCO-, -CONH-, -COO-, -OCO-, -NH- , -NHCONH-, -CO-.

In addition, in the above formula [IX], Y ₃ represents -CH ₂ -, -O-, -CONH-, -NHCO-, -COO-, -OCO-, -NH-, -CO- or a single bond. Y ₄ represents a cinnamyl group. Y ₅ represents a single bond, an alkylene group having 1 to 30 carbon atoms, or a divalent carbocyclic or heterocyclic ring. One or more hydrogen atoms in the alkylene group, divalent carbocyclic ring or heterocyclic ring may be substituted by a fluorine atom or an organic group. When Y ₅ is not adjacent to each other, -CH ₂ - can also be substituted by these groups; -O-, -NHCO-, -CONH-, -COO-, -OCO-, -NH- , -NHCONH-, -CO-. _Y6 represents a photopolymerizable group such as an acryl group or a methacryl group.

上述式(1c)中，X⁹ 及X¹⁰ 係各自獨立表示單鍵、-O-、 -COO-、-NHCO-或-NH-之鍵結基。Y表示可經氟原子取代之碳數1～20之伸烷基。As a specific example of the diamine which has the photoreactive side chain represented by the said formula [VIII] or [IX], the following formula (1c) is mentioned.

In the above formula (1c), X ⁹ and X ¹⁰ each independently represent a single bond, -O-, -COO-, -NHCO- or -NH-bonding group. Y represents an alkylene group having 1 to 20 carbons which may be substituted by a fluorine atom.

上述式[VII]中，Ar表示選自由伸苯基、伸萘基及伸聯苯基所成群之至少1種芳香族烴基，該等環之氫原子亦可被鹵素原子所取代。羰基所鍵結之Ar由於參與紫外線之吸收波長，故在長波長化之情況，以伸萘基或伸聯苯基般之共軛長度為長之構造為佳。另一方面，Ar在成為伸萘基或伸聯苯基般之構造時，有溶解性變差之情況，於此情況下，合成難易度變高。紫外線之波長若在250nm～380nm之範圍，即便為苯基仍能取得充分特性，故Ar係以苯基為最佳。As diamine which has a photoreactive side chain, the diamine of following formula [VII] is also mentioned. The diamine of the formula [VII] has a radical generating structure in the side chain. The free radical generating structure is decomposed by ultraviolet irradiation to generate free radicals.

In the above formula [VII], Ar represents at least one aromatic hydrocarbon group selected from the group consisting of phenylene, naphthylene and biphenylene, and the hydrogen atoms of these rings may be replaced by halogen atoms. Since the Ar bonded by the carbonyl group participates in the absorption wavelength of ultraviolet rays, in the case of a longer wavelength, a structure with a long conjugation length such as naphthyl or biphenyl is preferable. On the other hand, when Ar has a structure such as naphthyl or biphenyl, the solubility may deteriorate, and in this case, the difficulty of synthesis becomes high. If the wavelength of ultraviolet light is in the range of 250nm to 380nm, sufficient characteristics can be obtained even if it is phenyl, so phenyl is the best Ar system.

In the above-mentioned Ar, a substituent may be provided on the aromatic hydrocarbon group. Examples of the substituent here are preferably electron-donating organic groups such as alkyl groups, hydroxyl groups, alkoxy groups, and amino groups.

In addition, in the above formula [VII], R ₁ and R ₂ each independently represent an alkyl group having 1 to 10 carbon atoms, an alkoxy group, a benzyl group or a phenethyl group. In the case of an alkyl or alkoxy group, a ring may also be formed by R ₁ and R ₂ .

In addition, in the above formula [VII], _T1 and _T2 each independently represent a single bond, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O- , -N(CH ₃ )-, -CON(CH ₃ )- or -N(CH ₃ )CO- bonding group.

Also, in formula [VII], S represents a single bond, unsubstituted or fluorine atom-substituted C1-C20 alkylene group. The -CH ₂ - or -CF ₂ - of the alkylene group here can also be optionally substituted by -CH=CH-, any of the groups listed below can also be substituted by these groups when they are not adjacent to each other; -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, divalent carbocycle, and divalent heterocycle.

上述式(1d)中，R表示氫原子或碳原子數1～4之烷基。R₃ 表示-CH₂ -、-NR-、-O-、或-S-。In addition, in formula [VII], Q represents a structure selected from the following formula (1d).

In the above formula (1d), R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ₃ represents -CH ₂ -, -NR-, -O-, or -S-.

In addition, in the above formula [VII], Q is preferably an electron-donating organic group, preferably an alkyl group, a hydroxyl group, an alkoxy group, an amino group, etc. as mentioned above as examples of Ar. When Q is an amino derivative, when the polyimide precursor, that is, polyamic acid, is polymerized, due to the possibility of undesirable situations such as the formation of a salt between the carboxylic acid group and the amine group, the hydroxyl group Or alkoxy is preferred.

Also, in the above formula [VII], the positions of the two amine groups (-NH ₂ ) may be any of o-phenylenediamine, m-phenylenediamine, or p-phenylenediamine, From the viewpoint of reactivity with acid dianhydride, m-phenylenediamine or p-phenylenediamine is preferable.

Therefore, as a preferable specific example of the said formula [VII], the following formula can be mentioned from viewpoints, such as synthesis|combination easiness, the height of versatility, and a characteristic. In addition, in the following formulae, n is an integer of 2-8.

The diamines which have the photoreactive side chain represented by the said formula [VII], [VIII] or [IX] can be used individually by 1 type or in mixture of 2 or more types. According to the characteristics of liquid crystal alignment, pre-tilt angle, voltage retention characteristics, accumulated charge, etc. when making liquid crystal alignment films, and the response speed of liquid crystals when making liquid crystal display elements, etc., use alone or in combination of two or more types, and when mixed Two or more kinds are used, and the ratio thereof may be adjusted as appropriate.

<Other diamines: diamines other than those mentioned above> Diamines other than those mentioned above that may be included in the diamine component for obtaining a specific polymer are not limited to diamines having the above-mentioned specific structure. What is shown by following formula [2] is mentioned as an example of these diamines other than the above.

In the above formula [2], A ₁ and A ₂ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbons, an alkenyl group having 2 to 5 carbons, or an alkynyl group having 2 to 5 carbons. Among them, from the viewpoint of monomer reactivity, _A1 and _A2 are preferably hydrogen atoms or methyl groups. Also, if the structure of ^Y11 is exemplified, the following formulas (Y-1) to (Y-178) can be mentioned.

上述式中，對於n之範圍無特別記載者，則n為1～6之整數。又，上述式中，Me表示甲基。

In the above formula, n is an integer of 1-6, unless there is a particular description about the range of n. In addition, in the above formula, Me represents a methyl group.

上述式中，Boc表示tert-丁氧基羰基。

In the above formula, Boc represents tert-butoxycarbonyl.

The diamines other than those described above can be used in combination of two or more. When the diamine component contains diamines other than the above, the specific diamine in the specific polymer relative to other diamines is 5 to 70 mol% of the specific diamine, preferably 10 to 50 mol%, more preferably 10 to 50 mol%. The amount of 40mol% is advisable.

The polyimide precursor used in the present invention is obtained from the reaction of diamine components and tetracarboxylic acid derivatives, such as polyamic acid or polyamic acid ester. When the polyimide precursor comprising the structural unit shown in formula (6) contains the structural unit shown in formula (7) at the same time, with respect to the total of formula (6) and formula (7), the formula ( 6) The structural unit shown is preferably at least 10 mol%, more preferably at least 20 mol%, and most preferably at least 30 mol%. The molecular weight of the polyimide precursor used in the present invention is preferably 2,000-500,000, more preferably 5,000-300,000, more preferably 10,000-100,000.

Examples of polyimides having a divalent group represented by the formula (1) in the main chain include polyimides obtained by ring-closing the aforementioned polyimide precursor. In this polyimide, the ring-closing rate of the amide acid group (also referred to as the imidization rate) does not have to be 100%, and can be adjusted arbitrarily according to the application or purpose. As a method for imidizing the polyimide precursor, thermal imidization by directly heating the polyimide precursor solution, or adding a catalyst to the polyimide precursor solution can be mentioned. imidization.

＜Liquid crystal alignment agent＞ The liquid crystal alignment agent of the present invention contains the above-mentioned specific polymers, but may also contain two or more specific polymers with different structures. Moreover, other polymers may be contained other than a specific polymer, ie, the polymer which does not have the divalent group represented by formula (1) may be contained. Examples of polymer forms include polyamic acid, polyimide, polyamic acid ester, polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivatives, polyacetal , polystyrene or its derivatives, poly(styrene-phenylmaleimide) derivatives, poly(meth)acrylate, etc. When the liquid crystal alignment agent of the present invention contains other polymers, the ratio of the specific polymer to the total polymer component is preferably 5% by mass or more, for example, 5 to 95% by mass.

From the viewpoint of forming a uniform thin film, the liquid crystal alignment agent is generally in the form of a coating solution. The liquid crystal alignment agent of the present invention is also preferably a coating liquid containing the above-mentioned polymer component and an organic solvent for dissolving the polymer component. At this time, the concentration of the polymer in the liquid crystal alignment agent can be appropriately changed according to the setting of the thickness of the coating film to be formed. From the viewpoint of forming a uniform and defect-free coating film, it is preferably at least 1% by mass, and from the viewpoint of solution storage stability, it is preferably at most 10% by mass. The concentration of the particularly preferred polymer is 2 to 8% by mass.

The organic solvent contained in the liquid crystal alignment agent is not particularly limited as long as it dissolves the polymer component uniformly. If specific examples are given, such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone , Dimethylsulfone, γ-butyrolactone, 1,3-dimethyl-imidazolinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, etc. Among them, it is also preferable to use N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, or γ-butyrolactone.

In addition, the organic solvent contained in the liquid crystal alignment agent of the present invention can be used in addition to the above-mentioned solvents, and can also be used to improve the applicability of the liquid crystal alignment agent or the surface smoothness of the coating film. Specific examples of the organic solvent are listed below.

Examples include 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, 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, 2,6-dimethyl-4-heptanol, 1,2-ethyl Alkanediol, 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, diisopropyl ether, 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, di Ethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 2-pentanone, 3-pentanone , 2-hexanone, 2-heptanone, 4-heptanone, 2,6-dimethyl-4-heptanone, 4,6-dimethyl-2-heptanone, 3-ethoxybutyl ethyl ester, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, biscarbonate Propyl ester, ethyl carbonate, 2-(methoxymethoxy)ethanol, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2-(hexyloxy ) ethanol, furfuryl alcohol, diethylene glycol, propylene glycol, propylene glycol monobutyl ether, 1-(butoxyethoxy) propanol, propylene glycol monomethyl ether acetate, dipropylene glycol, diethylene glycol mono Ethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetic acid Esters, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene glycol monoethyl ether acetate ester, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy) ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene glycol mono Methyl ether, triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, pyruvate ethyl ester, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methylethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxy Propionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate Lactate, isoamyl lactate, solvents represented by the above formulas [D-1] to [D-3], etc.

Among them, the organic solvent is based on the use of 1-hexanol, cyclohexanol, 1,2-ethanediol, 1,2-propylene glycol, propylene glycol monobutyl ether, diethylene glycol diethyl ether, 4-hydroxy- 4-Methyl-2-pentanone, ethylene glycol monobutyl ether or dipropylene glycol dimethyl ether are preferred. The type and content of the solvent are appropriately selected according to the coating device, coating conditions, and coating environment of the liquid crystal alignment agent.

The liquid crystal alignment agent of the present invention may additionally contain components other than the polymer component and the organic solvent. Such additional components include, for example, adhesion aids for improving the adhesion between the liquid crystal alignment film and the substrate or the adhesion between the liquid crystal alignment film and the sealing material, crosslinking agents for improving the strength of the liquid crystal alignment film, adjusting Dielectric or conductive substances for dielectric rate or resistance of liquid crystal alignment film. Specific examples of these additional components include poor solvents or cross-linking compounds as disclosed in paragraph [0104] on page 53 to paragraph [0116] on page 60 of International Publication No. 2015/060357.

As the compound that enhances the adhesion between the liquid crystal alignment film and the substrate, compounds containing functional silanes or compounds containing epoxy groups can be mentioned, for example, 3-aminopropyltrimethoxysilane, 3- Aminopropyltriethoxysilane, 3-Glycidoxypropyltriethoxysilane, 3-Glycidoxypropyltrimethoxysilane, 3-Glycidoxypropylmethyl Diethoxysilane, 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-aminopropyltriethoxysilane, N-triethoxysilylpropyltrienylethyl Triamine, 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 ethyl Ester, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxy Silane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(oxyethylene)-3-aminopropyltrimethoxysilane, N-bis(oxyethylene)-3-amino Propyltriethoxysilane, Ethylene Glycol Diglycidyl Ether, Polyethylene Glycol Diglycidyl Ether, Propylene Glycol Diglycidyl Ether, Tripropylene Glycol Diglycidyl Ether, Polypropylene Glycol Diglycidyl Ether Oxypropyl 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-xylene Diamine, 1,3-bis(N,N-diepoxypropylaminomethyl)cyclohexane or N,N,N',N',-tetraepoxypropyl-4,4'-di Aminodiphenylmethane, etc.

Moreover, in order to improve the mechanical strength of the liquid crystal alignment film, the liquid crystal alignment agent of the present invention may also contain the following additives.

The amount of the above-mentioned additives is preferably 0.1-30 parts by mass relative to 100 parts by mass of the polymer component contained in the liquid crystal alignment agent. Since the effect cannot be expected when it is less than 0.1 mass parts, and since the alignment property of a liquid crystal will fall when it exceeds 30 mass parts, it is preferable that it is 0.5-20 mass parts.

In addition to the above, the liquid crystal alignment agent of the present invention may also contain polymers other than the specific polymers described in the present invention, dielectrics for the purpose of changing the electrical characteristics such as the dielectric constant or conductivity of the liquid crystal alignment film, A silane coupling agent for the purpose of improving the adhesion between the liquid crystal alignment film and the substrate, a cross-linking compound for the purpose of increasing the film hardness or density when making a liquid crystal alignment film, and a polyamide compound used for kneading the coating film Accelerators for imidization of imine precursors for the purpose of efficient imidization by heating.

＜Liquid crystal alignment film＞ The liquid crystal alignment film of the present invention is obtained from the aforementioned liquid crystal alignment agent. If one example of the method of obtaining a liquid crystal alignment film from a liquid crystal alignment agent is given, for example, for a film obtained by applying a liquid crystal alignment agent in the form of a coating liquid to a substrate, drying, and sintering, rubbing treatment or Photo-alignment treatment method A method of applying alignment treatment. In addition, in the VA system, it can also be used as it is without applying an alignment treatment.

The substrate on which the liquid crystal alignment agent is applied is not particularly limited as long as it is a highly transparent substrate, and plastic substrates such as glass substrates, silicon nitride substrates, acrylic substrates, and polycarbonate substrates can be used. On this occasion, it is preferable from the viewpoint of process simplification to use a substrate on which ITO electrodes and the like for driving liquid crystals have been formed. In addition, in reflective liquid crystal display elements, if only one side of the substrate is used, even opaque objects such as silicon wafers can be used. At this time, light-reflecting materials such as aluminum can also be used for the electrodes.

The coating method of liquid crystal alignment agent is generally screen printing, offset printing, flexo printing, inkjet method, etc. in the industry. As other coating methods, there are a dipping method, a roll coater method, a slit coater method, a spin coater method, a spray method, etc., and these can also be used according to the objective.

After the liquid crystal alignment agent is coated on the substrate, the solvent is evaporated and burned by heating means such as a heating plate, a thermal circulation oven, and an IR (infrared) oven. The drying and sintering steps after coating the liquid crystal alignment agent can choose any temperature and time. The drying step is not necessarily required, but if the entire substrate is not fixed in the time from coating to firing, or if the coating is not followed by firing, it is preferable to perform the drying step. This drying is to remove the solvent to the extent that the shape of the coating film will not be deformed by conveying the substrate. As for the drying means, for example, at a temperature of 40°C to 150°C, preferably at a temperature of 60°C to 100°C On the heating plate, dry for 0.5 minutes to 30 minutes, preferably for 1 minute to 5 minutes.

The firing temperature of the coating film formed by coating the liquid crystal alignment agent is, for example, 100-350°C, preferably 120-300°C, more preferably 150-250°C. The burning time is 5 minutes to 240 minutes, preferably 10 minutes to 90 minutes, more preferably 20 minutes to 90 minutes. Heating can be performed by a generally known method, such as a hot plate, a hot air circulation furnace, an infrared furnace, and the like. If the thickness of the liquid crystal alignment film after firing is too thin, the reliability of the liquid crystal display element may decrease, so it is preferably 5-300nm, more preferably 10-200nm.

When manufacturing TN-type, STN-type, IPS-type or FFS-type liquid crystal display elements, the coating film formed by the above-mentioned steps is subjected to the treatment of imparting liquid crystal alignment ability. Examples of alignment-imparting treatment include rubbing the coating film in a fixed direction with a roller wrapped with a cloth made of fibers such as nylon, rayon, and cotton, and irradiating the coating film with polarized or non-polarized light. Radiation light alignment processing, etc. On the other hand, when manufacturing VA-type liquid crystal display elements, the coating film formed by the above steps can be directly used as a liquid crystal alignment film, and the coating film can also be subjected to alignment ability imparting treatment.

In the photo-alignment treatment, as the radiation irradiated to the coating film, for example, ultraviolet rays and visible rays including wavelength rays of 150 to 800 nm can be used. When the radiation is polarized, it may be linearly polarized or partially polarized. Also, when the radiation used is linearly polarized or partially polarized, irradiation may be performed from a direction perpendicular to the substrate surface, from an oblique direction, or a combination thereof. When irradiating non-polarized radiation, the direction of irradiation is set as the oblique direction. 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, an LED lamp, or the like can be used. Ultraviolet rays in a preferable wavelength region can be obtained by means such as combining a light source with a filter, a diffraction grating, and the like. The radiation dose is preferably 100-50,000 J/m ² , more preferably 300-20,000 J/m ² .

In addition, the light irradiation to the coating film may be carried out simultaneously with heating the coating film in order to increase the reactivity. The temperature during heating is usually 30-250°C, preferably 40-200°C, more preferably 50-150°C. In the photo-alignment treatment system, heat treatment may be performed during light irradiation, or heat treatment may be performed after photo-alignment treatment. The heating temperature at this time is preferably 80-300°C, more preferably 120-250°C. The heating time is preferably 5-200 minutes, more preferably 10-100 minutes. Moreover, instead of the aforementioned heat treatment, washing treatment using an organic solvent or water may be performed, and washing treatment and heat treatment may be combined.

It is also possible to treat the liquid crystal alignment film after the rubbing treatment by irradiating ultraviolet rays to a part of the liquid crystal alignment film to change the pretilt angle of a part of the liquid crystal alignment film, or implement a part of the surface of the liquid crystal alignment film to form After the resist film is removed, the process of removing the resist film after rubbing treatment is carried out in a direction different from the previous rubbing treatment, so that the liquid crystal alignment film has different liquid crystal alignment capabilities according to the field. In this case, the viewing characteristics of the obtained liquid crystal display element can be improved.

The liquid crystal alignment film suitable for VA-type liquid crystal display elements can also be suitably used for PSA (Polymer Sustained Alignment) type liquid crystal display elements.

The liquid crystal alignment film of the present invention is also suitable as the liquid crystal alignment film of the liquid crystal display element of the transverse electric field method such as the IPS method or the fringe field switching (FFS, Fringe Field Switching) method, as the liquid crystal alignment film of the VA method, especially the liquid crystal display element of the PSA mode. Liquid crystal alignment films are also extremely useful.

＜Liquid crystal display elements＞ The liquid crystal display element of the present invention is obtained by obtaining a substrate with a liquid crystal alignment film obtained from the above-mentioned liquid crystal alignment agent, producing a liquid crystal cell by a known method, and using the liquid crystal cell to make a device. As a specific example of a liquid crystal display element that can be manufactured, such as a liquid crystal display element with a liquid crystal unit, the liquid crystal unit has: two substrates arranged in opposite directions, a liquid crystal layer disposed between the substrates, and a liquid crystal layer disposed between the substrates and the liquid crystal layer The liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention. More specifically, if a liquid crystal alignment film is formed by coating the liquid crystal alignment agent of the present invention on two substrates and firing, the two substrates are arranged so that the liquid crystal alignment films are facing each other. A liquid crystal layer made of liquid crystal is sandwiched between two substrates, that is, a liquid crystal display element in which a liquid crystal layer is provided in contact with a liquid crystal alignment film. The liquid crystal display element of the liquid crystal unit produced by irradiating ultraviolet rays at the same time.

As an example of a method of manufacturing a liquid crystal cell, a liquid crystal display element using a passive matrix structure will be described as an example. Specifically, transparent substrates were prepared, and then a liquid crystal alignment film was formed on each substrate under the aforementioned conditions. As mentioned above, the substrate is usually a substrate on which transparent electrodes for driving liquid crystals have been formed. As a specific example, the same thing as the substrate described in the said liquid crystal alignment film can be mentioned.

A common electrode is arranged on one side of the substrate, and a segment electrode is arranged on the other side of the substrate. These electrodes can be made as ITO electrodes, and can be patterned into desired image display. Next, an insulating film is provided on each substrate so as to cover the common electrodes and the segment electrodes. The insulating film can be, for example, a film composed of SiO ₂ -TiO ₂ formed by a sol-gel method.

In the liquid crystal display element of PSA mode, even if a line/slit electrode pattern of 1-10 μm is formed on one side substrate, and no slit pattern or protrusion pattern is formed on the opposite substrate, it can still operate. , the liquid crystal display element with this structure can simplify the manufacturing process and obtain high transmittance.

In the case of manufacturing IPS-type or FFS-type liquid crystal display elements, on the electrode formation surface of the substrate that is provided with electrodes composed of patterned comb-shaped transparent conductive films or metal films, the opposite side of the electrode is not provided. A liquid crystal alignment agent is coated on one surface of the substrate respectively, and then a coating film is formed by heating each coated surface. As the metal film, for example, a film made of metal such as chromium can be used.

Also, among high-performance devices such as TFT devices, devices such as transistors are used between electrodes for driving liquid crystals and a substrate.

In the case of a transmissive liquid crystal display device, the above-mentioned substrate is generally used, but in a reflective liquid crystal display device, if only one side of the substrate is used, an opaque substrate such as a silicon wafer can also be used. On this occasion, the electrodes formed on the substrate may also use materials such as aluminum that reflect light.

The liquid crystal material constituting the liquid crystal layer of the vertical alignment liquid crystal display element is not particularly limited, and the liquid crystal material used in the past vertical alignment method can be used, for example, MLC-6608 or MLC-6609, MLC-3022 manufactured by Merck & Co. Etc. Negative type liquid crystal. In addition, MLC-3023, which is a liquid crystal containing a polymerizable compound, can also be used in the PSA mode. Other liquid crystals containing, for example, a polymerizable compound represented by the following formula can also be used.

On the other hand, the liquid crystal material constituting the liquid crystal layer of the liquid crystal display element of the horizontal alignment method such as IPS or FFS can also use the liquid crystal material used in the past horizontal alignment method, for example, MLC-2003 or MLC- Negative and positive liquid crystals such as 2041 or negative liquid crystals such as MLC-6608.

As a method of pinching a liquid crystal layer between two board|substrates, a well-known method is mentioned. For example, prepare a pair of substrates on which a liquid crystal alignment film has been formed, and spread spacers such as beads on the liquid crystal alignment film of one substrate, so that the surface on which the liquid crystal alignment film has been formed is on the inside and bonded to the other. A method of injecting liquid crystal into one side of the substrate under reduced pressure and sealing it. Also, prepare a pair of substrates on which the liquid crystal alignment film has been formed, spread spacers such as beads on the liquid crystal alignment film of one substrate, drop liquid crystals, and then make the surface on which the liquid crystal alignment film has been formed become the inner side It is also possible to make a liquid crystal cell by attaching and sealing the substrate on the other side. The thickness of the spacer is preferably 1-30 μm, more preferably 2-10 μm.

The PSA mode method is to produce a liquid crystal cell by applying voltage to the liquid crystal alignment film and the liquid crystal layer and irradiating ultraviolet rays at the same time after holding the liquid crystal. As this step, for example, by applying a voltage between electrodes provided on the substrate, an electric field is applied to the liquid crystal alignment film and the liquid crystal layer, and a method of irradiating ultraviolet rays while maintaining the electric field is exemplified. Here, the voltage applied between the electrodes is, for example, 5 to 30 Vp-p or DC2.5 to 15V, preferably 10 to 30Vp-p or DC5 to 15V. In addition, as the light to be irradiated, ultraviolet rays including light having a wavelength of 300 to 400 nm are preferable. As a light source for irradiating light, it is as described above. The amount of irradiation of ultraviolet rays is, for example, 1 to 60J, preferably less than 40J. The lesser amount of ultraviolet irradiation is suitable because it can suppress the decrease in reliability caused by damage to the components constituting the liquid crystal display element, and by reducing the amount of ultraviolet irradiation time, thereby improving manufacturing efficiency.

As mentioned above, when a voltage is applied to the liquid crystal alignment film and the liquid crystal layer and ultraviolet rays are irradiated simultaneously, the polymerizable compound reacts to form a polymer, and the direction in which the liquid crystal molecules are inclined is memorized by the polymer, so that the obtained liquid crystal can be accelerated Displays the response speed of the device. In addition, when a voltage is applied to the liquid crystal alignment film and the liquid crystal layer while ultraviolet rays are irradiated, the polyimide is selected from a polyimide precursor having a side chain and a photoreactive side chain that make the liquid crystal vertically aligned, and the polyimide The photoreactive side chains of at least one polymer of the polyimide obtained by imidizing the precursor react with each other, or the photoreactive side chains of the polymer react with the polymerizable compound, so that Accelerate the response speed of obtained liquid crystal display elements. After the above steps are completed, install polarizing plates on the liquid crystal cell. Specifically, it is better to stick a pair of polarizing plates on the opposite side of the two substrates from the liquid crystal layer.

Furthermore, the liquid crystal alignment film and liquid crystal display element of the present invention are not limited as long as they use the liquid crystal alignment agent of the present invention, and may be produced using other known methods. The steps up to obtaining a liquid crystal display element from a liquid crystal alignment agent are disclosed in, for example, page 17 [0074] to page 19 [0081] of Japanese Patent Laid-Open Publication No. 2015-135393.

The liquid crystal display element of the present invention can be effectively applied to various devices, such as clocks, portable game machines, word processors, notebook personal computers, car navigation systems, video cameras, PDAs, digital cameras, mobile phones, smart phones, etc. Various display devices such as telephones, various screens, LCD TVs, and information displays. [Example]

The following examples are given to describe the present invention in more detail, but the present invention is not limited thereto. The meanings of the abbreviations of the compounds used in the examples are as follows. (acid dianhydride) BODA: Bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride. CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride. PMDA: benzene-1,2,4,5-tetracarboxylic anhydride. TCA: 2,3,5-tricarboxycyclopentylacetic acid-1,4,2,3-dianhydride (diamine) p-PDA: 1,4-phenylene diamine, DDM: 4,4'-methylene diphenylamine DBA: 3,5-diaminobenzoic acid

<Solvent> NMP: N-methyl-2-pyrrolidone, BCS: butyl cellosolve.

<Molecular weight measurement of polyimide> Measuring device: Gel Permeation Chromatography (GPC) (SSC-7200) made by Quanzhou Science Co., Ltd., Column: Shodex Co., Ltd. Column temperature: 50°C, eluent: N,N'-dimethylformamide (as an additive, lithium bromide-hydrate (LiBr・_H2O ) 30mmol/L, phosphoric acid・anhydrous crystal (o-phosphoric acid) 30mmol /L, tetrahydrofuran (THF) 10ml/L), flow rate: 1.0ml/min, standard sample for calibration curve creation: TSK standard polyethylene oxide (molecular weight: about 9000,000, 150,000, 100,000, 30,000), and polyethylene glycol (molecular weight about 12,000, 4,000, 1,000) manufactured by Polymer Laboratory Co., Ltd.

<Measurement of imidization rate> Put 20 mg of polyimide powder into an NMR sample tube (NMR sampling tube standard φ5 manufactured by Kusano Science Co., Ltd.), add deuterated dimethyl oxide (DMSO-d ₆ , 0.05% TMS Mixture) 1.0ml, apply ultrasonic waves to dissolve completely. This solution was measured for proton NMR at 500 MHz with an NMR measuring device (JNW-ECA500) manufactured by JEOL Ltd. (Chemical) imidization ratio is determined by determining the proton derived from the structure that does not change before and after imidization as a reference proton, and using the peak cumulative value of the proton, and the value that appears near 9.5 to 10.0ppm The calculated value of the proton peak derived from the NH group of amide acid is calculated according to the following formula. Moreover, in the formula, x is the accumulated value of the proton peak derived from the NH group of amide acid, y is the accumulated value of the peak of the reference proton, and α is the reference proton pair in polyamide acid (imidization rate is 0 %) The ratio of the number of 1 proton of the NH group of the amino acid in the case. Imidization rate (%)=(1-α・x/y)×100

Compounds DA-O1 to DA-O4 are novel compounds synthesized by the following operations. Products obtained from Synthesis Examples 1 to 4 of the following monomers were identified by ¹ H-NMR analysis. Analysis conditions are as follows. Device: Varian NMR System 400 NB (400 MHz) Measurement solvent: DMSO-d ₆ , Reference material: Tetramethylsilane (TMS) (δ0.0 ppm for ¹ H)

＜＜Synthesis Example 1: Synthesis of DA-O1＞＞

<Synthesis of Compound [1]> Methanol (320g), p-nitrobenzonitrile (40.0g, 270mmol), 2-amino-2-methyl-1,3-propanediol (142.3g), and sodium carbonate were mixed (28.6g) was put into a flask, and it was made to react for 22 hours under the reflux condition of nitrogen environment. After completion of the reaction, the reaction solution was poured into pure water (960 g) to precipitate crystals, followed by filtration and washing with methanol. Next, the obtained crude product was slurry washed with a mixed solvent of ethyl acetate (260g) and hexane (40g), and compound [1] was obtained as white crystals by filtration and drying (yield: 46.8g, yield : 73%). ¹ H-NMR(400MHz) in DMSO-d ₆ : 8.29-8.33ppm(m,2H), 8.07-8.11ppm(m,2H), 4.97ppm(t, J =6.0Hz,1H), 4.46ppm (d , J =8.4Hz,1H), 4.07ppm(d, J =8.4Hz,1H), 3.36-3.47ppm (m,2H), 1.25ppm(s,3H)

<Synthesis of compound [2]> N-methyl-2-pyrrolidone (380 g), compound [1] (44.7 g, 189 mmol), 4-fluoronitrobenzene (45.9 g), and sodium hydroxide ( 12.6 g) was put into a flask, and it was reacted for about 5 days at room temperature. After completion of the reaction, the reaction solution was poured into pure water (1124 g) to precipitate crystals, and the crude crystals were recovered by filtration. Next, room-temperature slurry washing was performed with methanol (179 g), and then slurry washing was performed with ethyl acetate (560 g). After the slurry was washed, compound [2] was obtained by filtration and drying as pale yellow crystals (amount: 51.4 g, yield: 76%). ¹ H-NMR(400MHz) in DMSO-d ₆ : 8.30-8.32ppm(m,2H), 8.15-8.19ppm(m,2H), 8.09-8.12ppm(m,2H), 7.13-7.18ppm (m, 2H), 4.56ppm(d, J =8.8Hz,1H), 4.27ppm(d, J =8.4Hz,1H), 4.26ppm(d, J =9.6Hz,1H), 4.21ppm(d, J =10.0 Hz,1H), 1.25ppm (s,3H)

<Synthesis of DA-O1> Put tetrahydrofuran (397g), methanol (99g), compound [2] (49.7g, 139mmol), 5% palladium-carbon (approximately 50% water wet product) (3.46g) into a flask , and allowed to react for 24 hours under hydrogen ambient room temperature conditions. After completion of the reaction, 5% palladium-carbon was removed by filtration, and the total internal weight was adjusted to 73.4 g by concentration under reduced pressure. Next, add 2-propanol (250g) and heat to 50°C to dissolve it, precipitate crystals under ice-cooling conditions, and obtain DA-O1 as white crystals by filtration and drying (yield: 30.2g, yield: 73 %). ¹ H-NMR(400MHz) in DMSO-d ₆ : 7.50-7.54ppm(m,2H), 6.62-6.66ppm(m,2H), 6.53-6.56ppm(m,2H), 6.45-6.49ppm (m, 2H), 5.7ppm(s,2H), 4.61ppm(s, 2H), 4.31ppm(d, J = 8.4Hz,1H), 4.00ppm(d, J =8.40Hz,1H), 3.74-3.79ppm( m,2H), 1.30ppm(s,3H)

＜<Synthesis Example 2: Synthesis of DA-O2 Synthesis>>

<Synthesis of compound [3]> Methanol (240g), p-nitrobenzonitrile (30.0g, 203mmol), 2-amino-1,3-propanediol (55.6g), and sodium carbonate (21.6g) were put into into a flask, and reacted for 23 hours under reflux under a nitrogen environment. After completion of the reaction, the reaction solution was poured into pure water (720 g) to precipitate crystals, followed by filtration and washing with methanol. Next, the obtained crude product was slurry washed with a mixed solvent of ethyl acetate (150 g) and hexane (30 g), and compound [3] was obtained as light yellow crystals by filtration and drying (yield: 30.9 g, yield rate: 69%). ¹ H-NMR(400MHz)in DMSO-d ₆ : 8.11-8.33ppm(m,2H), 8.09-8.12ppm(m,2H), 4.90ppm(t, J =5.6Hz,1H), 4.48-4.90ppm (m,1H), 4.33-4.41ppm(m,2H), 3.36-3.64ppm(m,2H)

<Synthesis of compound [4]> N-methyl-2-pyrrolidone (138 g), compound [3] (27.8 g, 126 mmol), 4-fluoronitrobenzene (28.8 g), and sodium hydroxide ( 7.6 g) was put into a flask, and it was reacted for about 4 days at room temperature. After completion of the reaction, ethyl acetate (504 g) and pure water (224 g) were added to the reaction liquid, and crystals were deposited. The crystals were recovered by filtration, and the recovered crystals were subjected to room temperature slurry washing with a mixed solvent of methanol (140 g) and pure water (140 g). After the slurry was washed, the compound product [4] was obtained by filtration, washing with methanol, and drying as light yellow crystals (amount: 31.3 g, yield: 72%). ¹ H-NMR(400MHz)in DMSO-d ₆ : 8.31-8.33ppm(m,2H), 8.17-8.21ppm(m,2H), 8.11-8.14ppm(m,2H), 7.15-7.19ppm (m, 2H), 4.76-4.83ppm(m,1H), 4.66-4.70ppm(m,1H), 4.42-4.46ppm(m,1H), 4.32-4.38ppm(m,1H)

<Synthesis of DA-O2> Tetrahydrofuran (217g), methanol (62.6g), compound [4] (31.3g, 91.2mmol), and 5% palladium-carbon (approximately 50% water wet product) (2.34g) were put into a flask, and reacted for 4 days under a hydrogen environment at 40°C. After the reaction was completed, 5% palladium-carbon was removed by filtration, and the solvent was removed by concentration under reduced pressure to obtain a crude product. Next, room temperature slurry was washed with methanol (243 g), and DA-O2 was obtained as pale pink crystals by filtration and drying (yield: 17.5 g, yield: 68%). ¹ H-NMR(400MHz)in DMSO-d ₆ : 7.53-7.56ppm(m,2H), 6.64-6.68ppm(m,2H), 6.54-6.57ppm(m,2H), 6.47-6.51ppm (m, 2H), 5.73ppm(s,2H), 4.62ppm(s,2H), 4.41-4.47ppm (m,2H), 4.15-4.18ppm(m,1H), 3.96-3.99ppm(m,1H), 3.79 -3.83ppm(m,1H)

＜＜Synthesis Example 3: Synthesis of DA-O3＞＞

<Synthesis of Compound [5]> Methanol (400 g), terephthalonitrile (50.2 g, 392 mmol), 2-amino-2-methyl-1,3-propanediol (165 g), and sodium carbonate (83.9 g ) was put into a flask, and it was reacted for 20 hours under nitrogen ambient reflux conditions. After completion of the reaction, the reaction solution was poured into pure water (1200 g) to precipitate crystals, and the crude product was recovered by filtration. By washing the obtained crude product with pure water (300 g x 6 times) and then with methanol (200 g x 2 times), compound [5] was obtained as white crystals (crude yield: 109.6 g, crude Yield: 100%). ¹ H-NMR(400MHz)in DMSO-d ₆ : 7.92ppm(s,4H), 4.94ppm(t, J =5.2Hz,2H), 4.41ppm(d, J =8.0Hz,2H), 4.01ppm ( d, J =8.0Hz,2H), 3.36-3.44ppm(m,4H), 1.23ppm(s,6H)

<Synthesis of compound [6]> Put N-methyl-2-pyrrolidone (327g), compound [5] (40.8g, 146mmol), and potassium hydroxide (21.2g) into a flask, 4-Fluoronitrobenzene (45.7 g) dissolved in N-methyl-2-pyrrolidone (19.9 g) was added dropwise under water cooling. After completion of the dropping, the dropping funnel was washed with N-methyl-2-pyrrolidone (21.4 g), and reacted at room temperature for 2 hours. After completion of the reaction, the reaction solution was poured into pure water (1200 g) to precipitate crystals, and then filtered, purified water, and methanol were washed. Next, the obtained crude crystals were slurry-washed with methanol (300 g) at room temperature. Thereafter, the crude crystals were heated and dissolved in chloroform (10009 g), methanol (466 g) was added to precipitate crystals, and compound [6] was obtained as pale yellow crystals by filtration and drying (yield: 63.2 g, yield: 79%). ¹ H-NMR(400MHz)in DMSO-d ₆ : 8.16-8.19ppm(m,4H), 7.95ppm(s,4H), 7.13-7.16ppm(m,4H), 4.52ppm (d, J =8.4Hz , 2H), 4.19-4.22ppm(m,6H), 1.42ppm(s,6H)

<Synthesis of DA-O3> Put tetrahydrofuran (509g), methanol (62.3g), compound [6] (62.7g, 115mmol), and 5% palladium-carbon (about 50% water wet product) (3.66g) into In the flask, it was reacted for 4 days under a hydrogen atmosphere at 40°C. After the reaction was complete, 5% palladium-carbon was removed by filtration. Next, the filtrate was washed with excess N,N-dimethylformamide. The obtained filtrate was concentrated under reduced pressure, methanol (660 g) was added to precipitate crystals, and DA-O3 was obtained by filtration as pale pink crystals (yield: 20.9 g, yield: 38%). ¹ H-NMR(400MHz)in DMSO-d ₆ : 7.96ppm(s,4H), 6.62-6.65ppm(m,4H), 6.46-6.49ppm(m,4H), 4.61ppm(s,4H), 4.47 ppm(d, J =8.4Hz,2H), 4.16ppm(d, J =8.4Hz,2H), 3.87ppm (d, J =9.2Hz,2H), 3.60ppm(d, J =9.2Hz,2H) , 1.36ppm(s,6H)

＜＜Synthesis Example 4: Synthesis of DA-O4＞＞

<Synthesis of compound [7]> N-methyl-2-pyrrolidone (400 g), compound [5] (40.0 g, 143 mmol), and triethylamine (38.0 g) were placed in a flask, and 4-Nitrobenzyl chloride (60.7 g) was charged in 4 aliquots under ambient water cooling. After charging, since stirring failure occurred, N-methyl-2-pyrrolidone (160g) was added and stirring property was ensured, and it was made to react at room temperature for about 15 hours. After completion of the reaction, the reaction liquid was poured into pure water (1500 g) to precipitate crystals, followed by filtration and washing with pure water and methanol. Next, the obtained crude product was heated and dissolved in tetrahydrofuran (560 g) at 50°C, and methanol (400 g) was added to precipitate crystals. Then, the obtained crystals were slurry-washed with tetrahydrofuran (160 g), and compound [7] was obtained as white crystals by filtration and drying (amount: 47.4 g, yield: 55%). ¹ H-NMR(400MHz)in DMSO-d ₆ : 8.24-8.30ppm(m,4H), 8.06-8.11ppm(m,4H), 7.93ppm(s,4H), 4.58-4.60ppm(m,2H) , 4.35-4.43ppm(m,4H), 4.19-4.22ppm(m,2H), 1.43ppm(s,6H)

<Synthesis of DA-O4> Tetrahydrofuran (453g), methanol (95.6g), N,N-dimethylformamide (400g), compound [7] (47.4g, 78.6mmol), and 5% palladium- Carbon (approximately 50% water wet product) (2.90g) was put into a flask, and it was reacted for about 3 days under hydrogen ambient room temperature conditions. 5% palladium-carbon was removed by filtration, and the internal weight was adjusted to 130 g by concentration under reduced pressure. Methanol (390 g) was added to the obtained homogeneous solution to precipitate crystals, and DA-O4 was obtained as white crystals by filtration and drying (yield: 17.3 g, yield: 41%). ¹ H-NMR(400MHz)in DMSO-d ₆ : 7.96ppm(s,4H), 7.52-7.55ppm(m,4H), 6.46-6.50ppm(m,4H), 5.96ppm(s,4H), 4.48 ppm(d, J =8.8Hz,2H), 4.16-4.22ppm(m,6H), 1.39ppm(s,6H)

＜Manufacturing example 1＞ BODA (1.25g, 5.00mmol), DA-O1 (2.08g, 7.00mmol) and DA-S1 (1.14g, 3.00mmol) were dissolved in NMP (17.9g), and reacted at 60°C for 3 hours. CBDA (0.92g, 4.70mmol) and NMP (3.70g) were added, it was made to react at 40 degreeC for 4 hours, and the polyamic-acid solution was obtained. The Mn of this polyamic acid is 10200, and the Mw is 25800. The liquid crystal alignment agent PAA-1 was obtained by adding NMP (5.40 g) and BCS (7.20 g) to the polyamic acid solution (5.4 g) and stirring at room temperature for 2 hours.

＜Manufacturing example 2＞ BODA (1.25g, 5.00mmol), DA-O2 (1.98g, 7.00mmol) and DA-S1 (1.14g, 3.00mmol) were dissolved in NMP (17.5g), and reacted at 60°C for 3 hours , CBDA (0.89g, 4.55mmol) and NMP (3.60g) were added, it was made to react at 40 degreeC for 4 hours, and the polyamic-acid solution was obtained. The Mn of this polyamic acid is 9800, and the Mw is 47700. The liquid crystal alignment agent PAA-2 was obtained by adding NMP (5.40 g) and BCS (7.20 g) to the polyamic acid solution (5.4 g) and stirring at room temperature for 2 hours.

＜Manufacturing example 3＞ BODA (3.13g, 12.5mmol), p-PDA (1.89g, 17.5mmol) and DA-S1 (2.85g, 7.50mmol) were dissolved in NMP (31.5g), and reacted at 60°C for 3 hours , CBDA (2.40g, 12.3mmol) and NMP (9.60g) were added, it was made to react at 40 degreeC for 4 hours, and the polyamic-acid solution was acquired. The Mn of this polyamic acid is 10800, and the Mw is 28000. The liquid crystal alignment agent PAA-3 was obtained by adding NMP (5.40 g) and BCS (7.20 g) to the polyamic acid solution (5.4 g) and stirring at room temperature for 2 hours.

＜Manufacturing example 4＞ BODA (1.25g, 5.00mmol), DA-O1 (2.08g, 7.00mmol) and DA-S1 (1.14g, 3.00mmol) were dissolved in NMP (17.9g), and reacted at 60°C for 3 hours , CBDA (0.92g, 4.70mmol) and NMP (3.70g) were added, it was made to react at 40 degreeC for 4 hours, and the polyamic-acid solution was acquired. After adding NMP to this polyamic acid solution (15g) and diluting it to 6.5% by mass, anhydrous acetic acid (2.81g) and pyridine (0.87g) were added as imidization catalysts, and reacted at 50°C for 3 hours . The reaction solution was poured into methanol (170 g), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 60° C. to obtain a polyimide powder. The imidization rate of this polyimide was 51%, Mn was 10100, and Mw was 25000. NMP (18.0 g) was added to the obtained polyimide powder (2.0 g), and it stirred and melt|dissolved at 70 degreeC for 12 hours. Liquid crystal alignment agent SPI-1 was obtained by adding BCS (13.3 g) to this solution and stirring at room temperature for 2 hours.

＜Manufacturing example 5＞ BODA (3.13g, 12.5mmol), p-PDA (1.89g, 17.5mmol) and DA-S1 (2.85g, 7.50mmol) were dissolved in NMP (31.5g), and reacted at 60°C for 3 hours , CBDA (2.40g, 12.3mmol) and NMP (9.60g) were added, it was made to react at 40 degreeC for 4 hours, and the polyamic-acid solution was acquired. After adding NMP to this polyamic acid solution (20g) and diluting it to 6.5% by mass, anhydrous acetic acid (4.94g) and pyridine (1.53g) were added as imidization catalysts, and reacted at 50°C for 3 hours . The reaction solution was poured into methanol (240 g), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 60° C. to obtain a polyimide powder. The imidization rate of this polyimide was 49%, Mn was 10600, and Mw was 27500. NMP (18.0 g) was added to the obtained polyimide powder (2.0 g), and it stirred and melt|dissolved at 70 degreeC for 12 hours. Liquid crystal alignment agent SPI-2 was obtained by adding BCS (13.3 g) to the solution and stirring at room temperature for 2 hours.

＜Manufacturing example 6＞ Dissolve DA-O1 (1.49g, 5.01mmol) in NMP (13.7g), add CBDA (0.93g, 4.73mmol) and NMP (4.01g), and react at 40°C for 4 hours to obtain polyamide acid solution. The Mn of this polyamic acid is 6500, and the Mw is 13800. The liquid crystal alignment agent PAA-4 was obtained by adding NMP (4.45 g) and BCS (7.67 g) to the polyamic acid solution (12.1 g) and stirring at room temperature for 2 hours.

＜Manufacturing example 7＞ DA-O1 (0.40g, 1.34mmol), p-PDA (0.14g and 1.33mmol) were dissolved in NMP (5.90g), and CBDA (0.50g, 2.55mmol) and NMP (1.71g) were added, at room temperature The reaction was carried out for 18 hours to obtain a polyamic acid solution. The Mn of this polyamic acid is 6000, and the Mw is 13200. The liquid crystal alignment agent PAA-5 was obtained by adding NMP (5.20 g) and BCS (3.46 g) to the polyamic acid solution (8.65 g) and stirring at room temperature for 2 hours.

＜Manufacturing example 8＞ Dissolve p-PDA (2.17g, 20.1mmol) in NMP (41.8g), add CBDA (3.61g, 18.4mmol) and NMP (9.46g), and react at 40°C for 4 hours to obtain polyamide acid solution. The Mn of this polyamic acid is 4800, and the Mw is 11200. NMP (15.2 g) and BCS (16.1 g) were added to the polyamic acid solution (49.1 g), and stirred at room temperature for 2 hours to obtain liquid crystal alignment agent PAA-6.

＜Manufacturing example 9＞ DA-O1 (2.97g, 10.0mmol) was dissolved in NMP (33.1g), PMDA (2.05g, 9.4mmol) and NMP (3.7g) were added, and reacted at room temperature for 15 hours to obtain polyamide acid solution. Liquid crystal alignment agent PAA-7 was obtained by taking out part (15.0 g) from the polyamic acid solution, adding NMP (15.0 g) and BCS (10.0 g) and stirring at room temperature for 2 hours.

＜Manufacturing example 10＞ DA-O2 (2.83g, 10.0mmol) was dissolved in NMP (32.2g), PMDA (2.05g, 9.4mmol) and NMP (3.60g) were added, and reacted at room temperature for 15 hours to obtain polyamide acid solution. Liquid crystal alignment agent PAA-8 was obtained by taking out part (15.0 g) from the polyamic acid solution, adding NMP (15.0 g) and BCS (10.0 g) and stirring at room temperature for 2 hours.

＜Manufacturing example 11＞ DA-P1 (15.7g, 60.0mmol) was dissolved in NMP (159.0g), PMDA (11.39g, 58.8mmol) and NMP (39.8g) were added, and reacted at room temperature for 15 hours to obtain polyamide acid solution. Liquid crystal alignment agent PAA-9 was obtained by taking out part (15.0 g) from the polyamic acid solution, adding NMP (15.0 g) and BCS (10.0 g) and stirring at room temperature for 2 hours.

＜Manufacturing example 12＞ DA-O3 (0.730g, 1.50mmol), p-PDA (0.164g, 1.52mmol) were dissolved in NMP (10.7g), CBDA (0.559g, 2.85mmol) was added and reacted at room temperature for 14 hours And obtain polyamide acid solution. The Mn of this polyamic acid is 7700, and the Mw is 20000. The liquid crystal alignment agent PAA-10 was obtained by adding NMP (7.23 g) and BCS (4.84 g) to the polyamic acid solution and stirring at room temperature for 2 hours.

＜Manufacturing example 13＞ DA-O4 (0.325g, 0.599mmol), p-PDA (0.261g, 2.41mmol) were dissolved in NMP (8.45g), CBDA (0.559g, 2.85mmol) was added, and it was made to react at room temperature for 14 hours And obtain polyamide acid solution. The Mn of this polyamic acid is 8700, and the Mw is 22000. The liquid crystal alignment agent PAA-11 was obtained by adding NMP (5.67 g) and BCS (3.81 g) to the polyamic acid solution and stirring at room temperature for 2 hours.

＜Manufacturing example 14＞ TCA (5.55 g, 25.5 mmol), DA-O1 (5.31 g, 17.90 mmol) and DA-S1 (2.91 g, 7.65 mmol) were dissolved in NMP (55.1 g), and reacted at 60° C. for 6 hours to obtain Obtain a polyamide solution. After adding NMP to this polyamic acid solution (23g) and diluting it to 6.5% by mass, anhydrous acetic acid (8.59g) and pyridine (1.33g) were added as imidization catalysts, and reacted at 80°C for 3 hours . The reaction solution was poured into methanol (320 g), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 60° C. to obtain a polyimide powder. The imidization rate of this polyimide was 59%, Mn was 15900, and Mw was 81000. NMP (37.8g) was added to the obtained polyimide powder (4.2g), and it stirred and melt|dissolved at 70 degreeC for 12 hours. Liquid crystal alignment agent SPI-3 was obtained by adding BCS (28.0 g) to this solution and stirring at room temperature for 2 hours.

＜Manufacturing example 15＞ After adding NMP to the polyamic acid solution (23g) obtained in Production Example 14 and diluting it to 6.5% by mass, anhydrous acetic acid (8.59g) and pyridine (1.33g) were added as imidization catalysts, and at 80°C It was allowed to react for 5 hours. The reaction solution was poured into methanol (320 g), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 60° C. to obtain a polyimide powder. The imidization rate of this polyimide was 70%, Mn was 14100, and Mw was 69200. NMP (37.8g) was added to the obtained polyimide powder (4.2g), and it stirred and melt|dissolved at 70 degreeC for 12 hours. Liquid crystal alignment agent SPI-4 was obtained by adding BCS (28.0 g) to this solution and stirring at room temperature for 2 hours.

＜Manufacturing example 16＞ TCA (3.35g, 15.0mmol), p-PDA (1.14g, 10.5mmol) and DA-S1 (1.71g, 4.50mmol) were dissolved in NMP (24.8g), and reacted at 60°C for 6 hours to obtain Obtain a polyamide solution. After adding NMP to this polyamic acid solution (20g) and diluting it to 6.5% by mass, anhydrous acetic acid (4.93g) and pyridine (1.53g) were added as imidization catalysts and reacted at 110°C for 4 hours . The reaction solution was poured into methanol (238 g), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 60° C. to obtain a polyimide powder. The imidization rate of this polyimide was 80%, Mn was 6660, and Mw was 16300. NMP (32.4g) was added to the obtained polyimide powder (3.6g), and it stirred and melt|dissolved at 70 degreeC for 12 hours. The liquid crystal alignment agent SPI-5 was obtained by adding BCS (24.0 g) to this solution and stirring at room temperature for 2 hours.

＜Manufacturing example 17＞ TCA (2.91g, 13.0mmol), DA-O1 (5.41g, 18.2mmol) and DA-S1 (2.97g, 7.80mmol) were dissolved in NMP (54.9g), and reacted at 60°C for 3 hours , CBDA (2.42g, 12.3mmol) and NMP (9.69g) were added, it was made to react at 40 degreeC for 4 hours, and the polyamic-acid solution was acquired. After adding NMP to this polyamic acid solution (23g) and diluting it to 6.5% by mass, anhydrous acetic acid (4.41g) and pyridine (1.37g) were added as imidization catalysts, and reacted at 75°C for 2.75 hours . The reaction solution was poured into methanol (306 g), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 60° C. to obtain a polyimide powder. The imidization rate of this polyimide was 70%, Mn was 13800, and Mw was 39000. NMP (37.8g) was added to the obtained polyimide powder (4.2g), and it stirred and melt|dissolved at 70 degreeC for 12 hours. Liquid crystal alignment agent SPI-6 was obtained by adding BCS (28.0 g) to this solution and stirring at room temperature for 2 hours.

＜Manufacturing example 18＞ TCA (3.92g, 17.5mmol), p-PDA (2.65g, 24.5mmol) and DA-S1 (4.00g, 10.5mmol) were dissolved in NMP (42.3g), and reacted at 60°C for 3 hours , CBDA (3.26g, 16.6mmol) and NMP (13.0g) were added, it was made to react at 40 degreeC for 4 hours, and the polyamic-acid solution was acquired. After adding NMP to this polyamic acid solution (23g) and diluting it to 6.5% by mass, anhydrous acetic acid (5.87g) and pyridine (1.82g) were added as imidization catalysts, and reacted at 50°C for 3 hours . The reaction solution was poured into methanol (320 g), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 60° C. to obtain a polyimide powder. The imidization rate of this polyimide was 85%, Mn was 12800, and Mw was 19900. NMP (37.8g) was added to the obtained polyimide powder (4.2g), and it stirred and melt|dissolved at 70 degreeC for 12 hours. The liquid crystal alignment agent SPI-7 was obtained by adding BCS (28.0 g) to this solution and stirring at room temperature for 2 hours.

＜Manufacturing example 19＞ BODA (2.63g, 10.5mmol), DA-P2 (1.67g, 8.40mmol), DA-O1 (2.50g, 8.40mmol) and DA-S2 (1.65g, 4.20mmol) were dissolved in NMP (33.8g) , After making it react at 60 degreeC for 3 hours, CBDA (1.96g, 9.98mmol) and NMP (7.82g) were added, it was made to react at 40 degreeC for 4 hours, and the polyamic-acid solution was obtained. The Mn of this polyamic acid is 8500, and the Mw is 20100. The liquid crystal alignment agent PAA-12 was obtained by adding NMP (15 g) and BCS (20 g) to the polyamic acid solution (15 g) and stirring at room temperature for 2 hours.

＜Manufacturing example 20＞ BODA (2.69g, 10.8mmol), DA-P2 (1.71g, 8.60mmol), DA-O1 (1.28g, 4.30mmol), DA-P3 (1.04g, 4.30mmol) and DA-S2 (1.69g, 4.30mmol) was dissolved in NMP (33.7g) and reacted at 60°C for 3 hours, then CBDA (2.00g, 10.2mmol) and NMP (8.01g) were added and reacted at 40°C for 4 hours to obtain polyamide solution. The Mn of this polyamic acid is 9300, and the Mw is 24000. The liquid crystal alignment agent PAA-13 was obtained by adding NMP (15 g) and BCS (20 g) to the polyamic acid solution (15 g) and stirring at room temperature for 2 hours.

＜Manufacturing example 21＞ BODA (2.75g, 11.0mmol), DA-P2 (1.75g, 8.80mmol), DA-P3 (2.13g, 8.80mmol) and DA-S2 (1.67g, 4.40mmol) were dissolved in NMP (33.3g) , After making it react at 60 degreeC for 3 hours, CBDA (2.07g, 10.6mmol) and NMP (8.28g) were added, it was made to react at 40 degreeC for 4 hours, and the polyamic-acid solution was acquired. The Mn of this polyamic acid is 10600, and the Mw is 33000. The liquid crystal alignment agent PAA-14 was obtained by adding NMP (15 g) and BCS (20 g) to the polyamic acid solution (15 g) and stirring at room temperature for 2 hours.

＜Manufacturing example 22＞ BODA (1.15g, 4.6mmol), DBA (0.70g, 4.60mmol), DA-O1 (1.37g, 4.60mmol), DA-P3 (1.67g, 6.90mmol) and DA-S1 (2.63g, 6.90mmol ) was dissolved in NMP (30.1 g), and after reacting at 60°C for 3 hours, CBDA (2.59, 34.2 mmol) and NMP (10.4 g) were added, and after reacting at room temperature for 1 hour, PMDA ( 1.00 g, 4.60 mmol) and NMP (4.01 g) were reacted at room temperature for 3 hours to obtain a polyamic acid solution. After adding NMP to this polyamic acid solution (28g) and diluting it to 6.5% by mass, anhydrous acetic acid (5.86g) and pyridine (1.81g) were added as imidization catalysts, and reacted at 80°C for 3 hours . The reaction solution was poured into methanol (370 g), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 60° C. to obtain a polyimide powder. The imidization rate of this polyimide was 87%, Mn was 12600, and Mw was 33300. NMP (37.8g) was added to the obtained polyimide powder (4.2g), and it stirred and melt|dissolved at 70 degreeC for 12 hours. The liquid crystal alignment agent SPI-8 was obtained by adding BCS (28.0 g) to this solution and stirring at room temperature for 2 hours.

＜Manufacturing example 23＞ BODA (4.88g, 19.5mmol), DDM (1.93g, 9.75mmol), DA-P4 (1.29g, 3.90mmol), DA-P5 (2.78g, 11.7mmol) and DA-S2 (5.39g, 13.7mmol ) was dissolved in NMP (65.3g) and reacted at 60°C for 3 hours, then CBDA (3.63, 18.5mmol) and NMP (14.5g) were added and reacted at 40°C for 4 hours to obtain polyamide acid solution. After adding NMP to this polyamic acid solution (55g) and diluting it to 6.5% by mass, anhydrous acetic acid (10.9g) and pyridine (3.38g) were added as imidization catalysts, and reacted at 80°C for 3 hours . The reaction solution was poured into methanol (730 g), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 60° C. to obtain a polyimide powder. The imidization ratio of this polyimide was 74%, Mn was 13900, and Mw was 40700. NMP (37.8g) was added to the obtained polyimide powder (4.2g), and it stirred and melt|dissolved at 70 degreeC for 12 hours. BCS (28.0g) was added to this solution, and it stirred at room temperature for 2 hours, and obtained liquid crystal aligning agent SPI-9.

＜Manufacturing example 24＞ BODA (1.00g, 4.00mmol), DBA (1.22g, 8.00mmol), DA-P3 (1.45g, 6.00mmol) and DA-S1 (2.28g, 6.00mmol) were dissolved in NMP (23.8g), in After reacting at 60° C. for 3 hours, CBDA (2.27, 11.6 mmol) and NMP (9.01 g) were added, and after reacting at room temperature for 1 hour, PMDA (0.87 g, 4.00 mmol) and NMP (3.49 g ), it was reacted at room temperature for 3 hours to obtain a polyamic acid solution. After adding NMP to this polyamic acid solution (g) and diluting to 6.5% by mass, anhydrous acetic acid (g) and pyridine (g) were added as an imidization catalyst, and it was made to react at 80 degreeC for 3 hours. The reaction solution was poured into methanol (370 g), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 60° C. to obtain a polyimide powder. The imidization rate of this polyimide was 74%, Mn was 11000, and Mw was 27400. NMP (37.8g) was added to the obtained polyimide powder (4.2g), and it stirred and melt|dissolved at 70 degreeC for 12 hours. Liquid crystal alignment agent SPI-10 was obtained by adding BCS (28 g) to this solution and stirring at room temperature for 2 hours.

＜Manufacturing example 25＞ The liquid crystal alignment agent SPI-11 was obtained by stirring the liquid crystal alignment agent SPI-8 (7.00 g) obtained in Production Example 22 and the liquid crystal alignment agent SPI-9 (3.00 g) obtained in Production Example 23 at room temperature for 3 hours.

＜Manufacturing example 26＞ By stirring the liquid crystal alignment agent SPI-8 (7.00g) obtained in Production Example 22, the liquid crystal alignment agent SPI-9 (3.00g) and AD-1 (0.06g) obtained in Production Example 23 at room temperature for 3 hours. Obtain liquid crystal alignment agent SPI-12.

＜Manufacturing example 27＞ By stirring the liquid crystal alignment agent SPI-8 (7.00g) obtained in Production Example 22, the liquid crystal alignment agent SPI-9 (3.00g) and AD-2 (0.06g) obtained in Production Example 23 at room temperature for 3 hours Obtain liquid crystal alignment agent SPI-13.

＜Manufacturing example 28＞ BODA (1.25g, 5.00mmol), DA-O3 (3.41g, 7.00mmol), and DA-S1 (1.14g, 3.00mmol) were dissolved in NMP (23.2g), and reacted at 60°C for 3 hours Then, CBDA (0.88g, 4.50mmol) and NMP (3.50g) were added, it was made to react at 40 degreeC for 4 hours, and the polyamic-acid solution was obtained. The number average molecular weight of this polyamide acid is 10500, and the weight average molecular weight is 30700. The liquid crystal alignment agent PAA-15 was obtained by adding NMP (5.40 g) and BCS (7.20 g) to the polyamic acid solution (5.4 g) and stirring at room temperature for 2 hours.

＜Manufacturing example 29＞ BODA (1.88g, 7.50mmol), DA-P4 (2.48g, 7.50mmol), DA-O1 (1.12g, 3.75mmol), and DA-S3 (2.84g, 3.75mmol) were dissolved in NMP (33.2g) In, after making it react at 60 degreeC for 3 hours, CBDA (1.43g, 7.31mmol) and NMP (5.50g) were added, it was made to react at 40 degreeC for 4 hours, and the polyamic-acid solution was obtained. After adding NMP to this polyamic acid solution (25g) and diluting it to 6.5% by mass, anhydrous acetic acid (3.92g) and pyridine (1.21g) were added as imidization catalysts, and reacted at 80°C for 3 hours . The reaction solution was poured into methanol (287 g), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 60° C. to obtain a polyimide powder. The imidization rate of this polyimide was 76%, Mn was 15000, and Mw was 55800. NMP (18.0 g) was added to the obtained polyimide powder (2.0 g), and it stirred and melt|dissolved at 70 degreeC for 12 hours. Liquid crystal alignment agent SPI-14 was obtained by adding BCS (13.3 g) to this solution and stirring at room temperature for 2 hours.

＜Manufacturing example 30＞ BODA (2.13g, 8.50mmol), DA-P4 (2.81g, 8.50mmol), p-PDA (0.46g, 4.25mmol), and DA-S3 (3.22g, 4.25mmol) were dissolved in NMP (34.4g) In, after making it react at 60 degreeC for 3 hours, CBDA (1.59g, 8.11mmol) and NMP (6.40g) were added, it was made to react at 40 degreeC for 4 hours, and the polyamic-acid solution was obtained. After adding NMP to this polyamic acid solution (45.1g) and diluting it to 6.5% by mass, anhydrous acetic acid (7.62g) and pyridine (2.36g) were added as imidization catalysts and reacted at 75°C for 2.5 Hour. The reaction solution was poured into methanol (456 g), and the obtained precipitate was separated by filtration. This precipitate was washed with methanol, and dried under reduced pressure at 60° C. to obtain a polyimide powder. The imidization rate of this polyimide was 75%, Mn was 16500, and Mw was 46600. NMP (18.0 g) was added to the obtained polyimide powder (2.0 g), and it stirred and melt|dissolved at 70 degreeC for 12 hours. The liquid crystal alignment agent SPI-15 was obtained by adding BCS (13.3 g) to this solution and stirring at room temperature for 2 hours.

The specifications of the liquid crystal alignment agents obtained in the above manufacturing examples 1 to 30 are shown in the following Tables 1-1 to 1-3.

<Example 1> Using the liquid crystal alignment agent PAA-1 obtained in Production Example 1, a liquid crystal cell was prepared in the following operation procedure. Spin-coat liquid crystal alignment agent PAA-1 on a glass substrate with ITO electrodes, dry it on a hot plate at 80°C for 90 seconds, and then bake it in a hot air circulation oven at 230°C for 30 minutes to form a film with a thickness of 100nm The liquid crystal alignment film. Two of these substrates with liquid crystal alignment films were prepared, and a thermosetting sealant (XN-1500T manufactured by Kyoritsu Chemical Co., Ltd.) was printed on one of the liquid crystal alignment films. Next, after affixing the other substrate to the previous substrate so that the surface on which the liquid crystal alignment film has been formed faces inward, the sealant is cured to form an empty cell. Liquid crystal MLC-3023 (trade name manufactured by Merck) containing a polymerizable compound for PSA was injected into this empty cell by a reduced-pressure injection method to produce a liquid crystal cell. The voltage holding ratio (VHR) of this liquid crystal cell was measured.

Next, the liquid crystal cell was treated with PSA, and the voltage retention rate after PSA treatment was measured. And, the unit was aged under high-temperature and high-humidity conditions, and the voltage retention rate after aging was measured. [Evaluation of voltage retention rate] In a hot air circulation oven at 60°C, apply a voltage of 1V for 60μs, then measure the voltage after 1667msec, and calculate how long the voltage can be maintained as the voltage retention rate. The measurement of the voltage retention ratio uses VHR-1 manufactured by Dongyang Technology Co., Ltd.

[PSA treatment] In the state where a DC voltage of 15V was applied, 10J/cm ² of UV which passed through a cutoff filter of 325nm or less was irradiated from the outside of the liquid crystal cell. In addition, the UV illuminance was measured using UV-MO3A manufactured by ORC Corporation. Thereafter, for the purpose of deactivating the unreacted polymerizable compound remaining in the liquid crystal cell, UV was irradiated with a UV-FL irradiation device manufactured by Toshiba Lighting Technology Co., Ltd. (UV lamp: FLR40SUV32/A-1) in a state where no voltage was applied. 30 minutes. [Aging] The PSA-treated liquid crystal cell was placed in a constant temperature and humidity chamber set at 85°C and a humidity of 85% for 10 days.

<Examples 2, 3, 10, 11, 12, 13, 14, Comparative Examples 1, 2, 5, 6, 7> In addition to replacing the liquid crystal alignment agent PAA-1, the liquid crystal alignment agent PAA-2, PAA-3, PAA-15, SPI-1, SPI-2, SPI-3, SPI-4, SPI-5, SPI-6 were used instead , SPI-7, SPI-14, and SPI-15, the others were operated in the same manner as in Example 1 to produce individual liquid crystal cells. For each liquid crystal cell obtained, operate in the same manner as in Example 1, and measure the voltage retention rate at the initial stage, after PSA treatment, after aging, and the drop value (Δ(after PSA treatment-after aging) of the voltage retention rate due to aging )). Individual results are shown in Table 2 below.

As shown in Table 2, in Comparative Examples 1, 2, and 5 using liquid crystal alignment agents PAA-3, SPI-2, SPI-5, SPI-7, and SPI-15 that do not contain polymers with an oxazoline skeleton , 6, and 7, when using liquid crystal alignment agents PAA-1, PAA-2, PAA-15, SPI-1, SPI-3, SPI-4, SPI-6, In Examples 1, 2, 10, 3, 11, 12, 13, and 14 of SPI-14, it was found that the decrease in the voltage retention rate due to aging was small. Therefore, it is known that a liquid crystal alignment agent comprising a polymer having an oxazoline skeleton can obtain a liquid crystal alignment film that is less prone to decrease in voltage retention due to aging.

[Friction Resistance] The liquid crystal alignment agent was spin-coated on the ITO surface of the glass substrate with ITO electrodes attached to the entire surface, and temporarily dried on a heating plate at 70°C for 90 seconds. Thereafter, it was baked in an IR oven at 230° C. for 30 minutes to form a coating film with a thickness of 100 nm to obtain a substrate with a liquid crystal alignment film. The liquid crystal alignment film was rubbed with rayon cloth (roll diameter: 120 mm, roll rotation speed: 1000 rpm, moving speed: 20 mm/sec, press-in length: 0.6 mm). The substrate was observed with a microscope, and those on which no streaks due to friction were found on the film surface were rated as "good", and those where streaks were found were rated as "poor".

<Examples 4 to 9, Comparative Examples 3 and 4> For the liquid crystal alignment agents PAA-4, PAA-5, PAA-6, PAA-7, PAA-8, PAA-9, PAA-10, and PAA-11, the above rubbing resistance was evaluated. Individual results are shown in Table 3 below.

As shown in Table 3, examples 4 and 5 of liquid crystal alignment agents PAA-4, PAA-5, PAA-7, PAA-8, PAA-10, and PAA-11 containing polymers with an oxazoline skeleton , 6, 7, 8, and 9, no streaks due to rubbing treatment were found, so it was good. On the other hand, in Comparative Examples 3 and 4 of liquid crystal alignment agents PAA-6 and PAA-9 not containing a polymer having an oxazoline skeleton, many streaks due to rubbing were found, so they were unfavorable. Therefore, it is known that a liquid crystal alignment agent containing a polymer having an oxazoline skeleton can obtain a liquid crystal alignment film that is less prone to film peeling or scratches caused by rubbing treatment.

<Example 15> Using the liquid crystal alignment agent PAA-12 obtained in manufacture example 19, the preparation of the adhesion evaluation sample was performed by the operation procedure shown below. Spin-coat liquid crystal alignment agent PAA-12 on a glass substrate with ITO electrodes, dry it on a heating plate at 80°C for 90 seconds, and then bake it in a hot air circulation oven at 230°C for 30 minutes to form a film Liquid crystal alignment film with a thickness of 100nm.

Two substrates thus obtained were prepared, and after coating 4 μm spacer beads on the liquid crystal alignment film surface of one substrate, a sealant (XN-1500T manufactured by Kyoritsu Chemical Co., Ltd.) was dropped. Next, it bonded so that the liquid crystal alignment film surface of the other board|substrate faced inward, and the overlapping width of a board|substrate became 1 cm. On this occasion, the sealing agent dropping amount was adjusted so that the diameter of the bonding sealing agent may become 3 mm. After fixing the bonded two boards with a jig, they were thermally cured at 150°C for 1 hour to prepare a sample for adhesion evaluation. [Measurement of Adhesion] The above-mentioned sample substrates were placed in a desktop precision universal testing machine (AGS-X 500N manufactured by Shimadzu Corporation), and after fixing the edge portions of the upper and lower substrates, they were pushed in from the upper part of the central part of the substrates, and the force at the time of peeling was measured ( N).

<Examples 16, 17, 18, 19, 20, Comparative Examples 10, 11> Except that the liquid crystal alignment agent PAA-12 is replaced by the liquid crystal alignment agent PAA-13, PAA-14, SPI-8, SPI-10, SPI-11, SPI-12, and SPI-13, the other systems are the same as in Example 15. Do the same and measure the individual adhesion. Individual results are shown in Table 4 below.

As shown in Table 4, compared with Comparative Examples 10 and 11 using liquid crystal alignment agents PAA-14 and SPI-10 that do not contain a polymer with an oxazoline skeleton, when using a polymer with an oxazoline skeleton The liquid crystal alignment agents PAA-12, PAA-13, SPI-8, SPI-11, SPI-12, and SPI-13 in Examples 15, 16, 17, 18, 19, and 20 confirmed that the seal adhesion is strong .

Moreover, the entire content of the Japanese patent application No. 2017-175632 filed on September 13, 2017, including the specification, scope of claims, drawings, and abstract, is hereby cited as the disclosure content of the specification of the present invention and introduced .

Claims (11)

A liquid crystal alignment agent, characterized by containing a polymer with an oxazoline skeleton, and the polymer is derived from a diamine selected from the following formulas (2-1), (2-2) and (2-3) the polymer;

R ¹ represents hydrogen or a monovalent organic group; R ² represents a group consisting of a single bond, -O-, -COO-, -OCO-, -(CH ₂ ) _l -, -O(CH ₂ ) _l O-, - A divalent organic group composed of at least one of CONR ¹¹ -, -NR ¹¹ CO- and -NR ¹¹ -; W ¹ represents a structure selected from the following group (3-1); W ² represents a structure selected from the following The structure of said group (3-2); W ³ represents the structure selected from the following group (3-3); W ⁴ represents the structure selected from the following group (3-4); Here, R ¹¹ represents hydrogen, Or a monovalent organic group, l represents an integer from 1 to 12, and a represents an integer from 0 or 1;

In the group (3-1), * ₁ represents the position bonded to the amino group in the formula (2-1) ~ (2-3), and * ₂ represents the position bonded to the oxazoline ring; the group (3- 2), * ₁ represents the position bonded to the amino group in formula (2-1) ~ (2-3), * ₃ represents the position bonded to R ² ; in group (3-3), * ₃ Represents the site bonded to ^R2 ; in group (3-4), * ₂ represents the site bonded to the oxazoline ring; X represents a hydrogen atom, a halogen atom, an alkyl group with 1 to 6 carbons, and a carbon number 1 ~6 halogenated alkyl groups, substituted amino groups, alkoxy groups with 1~6 carbon atoms, or amido groups. The liquid crystal alignment agent as claimed in item 1, wherein the aforementioned polymer having an oxazoline skeleton is a polyimide precursor selected from a structural unit represented by the following formula (6), and a polyimide compound thereof. At least one type of group of imides;

X ₁ represents a 4-valent organic group derived from a tetracarboxylic acid derivative; Y ₁ represents a 2-valent organic group derived from a diamine, and the diamine comprises the following formula (2-1), (2-2) or ( 2-3) The structure in which two amino groups are removed from the diamine; R ₄ represents a hydrogen atom or an alkyl group with 1 to 5 carbons. The liquid crystal alignment agent according to claim 2, wherein in the aforementioned formula (6), the structure of _X1 is at least one selected from the following structures;

The liquid crystal alignment agent according to claim 2 or 3, wherein the structural unit represented by the aforementioned formula (6) is more than 10 mol % relative to all structural units of the aforementioned polymer. A liquid crystal alignment film obtained from the liquid crystal alignment agent according to any one of claims 1-4. A liquid crystal display element, which is provided with the liquid crystal alignment film according to claim 5. A kind of diamine, it has the oxazoline skeleton shown in following formula (2-1), (2-2) or (2-3)

The definition of each symbol is the same as that described in Claim 1. A polymer having an oxazoline skeleton derived from the diamine as claimed in claim 7. The polymer as claimed in item 8, wherein the aforementioned polymer having an oxazoline skeleton is a polyimide precursor comprising a structural unit shown in the following formula (6), and a polyimide of an imidate thereof

The definition of each symbol is the same as that described in claim 2. The polymer as claimed in item 9, wherein in the aforementioned formula (6), the structure of _X1 is at least one selected from the following structures

The polymer according to claim 9 or 10, wherein the structural unit represented by the aforementioned formula (6) is 10 mol% or more relative to all structural units of the aforementioned polymer.