JP2018045180A - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal alignment film for a lateral electric field drive type liquid crystal display that has high performance, is provided with alignment controllability, and is excellent in burn-in resistance.SOLUTION: A liquid crystal alignment agent contains a polymer obtained from diamine having a structure represented by the following formula and an organic solvent.SELECTED DRAWING: None

Description

  The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display element for producing a liquid crystal display element having excellent image sticking characteristics.

  The liquid crystal display element is known as a light, thin and low power consumption display device, and has been remarkably developed in recent years. The liquid crystal display element is configured, for example, by sandwiching a liquid crystal layer between a pair of transparent substrates provided with electrodes. In the liquid crystal display element, an organic film made of an organic material is used as the liquid crystal alignment film so that the liquid crystal is in a desired alignment state between the substrates.

  That is, the liquid crystal alignment film is a constituent member of the liquid crystal display element, and is formed on a surface of the substrate that holds the liquid crystal in contact with the liquid crystal, and plays a role of aligning the liquid crystal in a certain direction between the substrates. The liquid crystal alignment film may be required to play a role of controlling the pretilt angle of the liquid crystal in addition to the role of aligning the liquid crystal in a certain direction such as a direction parallel to the substrate. In such a liquid crystal alignment film, the ability to control the alignment of liquid crystal (hereinafter referred to as alignment control ability) is given by performing an alignment treatment on the organic film constituting the liquid crystal alignment film.

  A rubbing method is conventionally known as an alignment treatment method for a liquid crystal alignment film for imparting alignment control ability. The rubbing method is a method of rubbing (rubbing) the surface of an organic film such as polyvinyl alcohol, polyamide or polyimide on a substrate with a cloth such as cotton, nylon or polyester in the rubbing direction (rubbing direction). This is a method of aligning liquid crystals. Since this rubbing method can easily realize a relatively stable alignment state of liquid crystals, it has been used in the manufacturing process of conventional liquid crystal display elements. As an organic film used for the liquid crystal alignment film, a polyimide-based organic film excellent in reliability such as heat resistance and electrical characteristics has been mainly selected.

  However, in the rubbing method of rubbing the surface of the liquid crystal alignment film made of polyimide or the like, generation of dust or static electricity may be a problem. In addition, due to the high definition of the liquid crystal surface element in recent years and the unevenness caused by the corresponding electrodes on the substrate and the switching active element for driving the liquid crystal, the surface of the liquid crystal alignment film cannot be uniformly rubbed with a cloth. In some cases, alignment of the liquid crystal could not be realized.

  Therefore, a photo-alignment method has been actively studied as another alignment treatment method for a liquid crystal alignment film that is not rubbed.

  There are various photo alignment methods. Anisotropy is formed in the organic film constituting the liquid crystal alignment film by linearly polarized light or collimated light, and the liquid crystal is aligned according to the anisotropy.

  A decomposition type photo-alignment method is known as a main photo-alignment method. For example, the polyimide film is irradiated with polarized ultraviolet rays, and anisotropic decomposition is caused by utilizing the polarization direction dependence of the ultraviolet absorption of the molecular structure. Then, the liquid crystal is aligned by the polyimide remaining without being decomposed (see, for example, Patent Document 1).

  In addition, photocrosslinking type and photoisomerization type photo-alignment methods are also known. For example, polyvinyl cinnamate is used and irradiated with polarized ultraviolet rays to cause a dimerization reaction (crosslinking reaction) at the double bond portion of two side chains parallel to the polarized light. Then, the liquid crystal is aligned in a direction perpendicular to the polarization direction (see, for example, Non-Patent Document 1). In addition, when a side chain polymer having azobenzene in the side chain is used, irradiation with polarized ultraviolet light causes an isomerization reaction at the azobenzene portion of the side chain parallel to the polarized light, and the liquid crystal is aligned in a direction perpendicular to the polarization direction. Align (for example, see Non-Patent Document 2).

  As in the above example, the liquid crystal alignment film alignment treatment method by the photo alignment method eliminates the need for rubbing, and there is no fear of generation of dust or static electricity. An alignment process can be performed even on a substrate of a liquid crystal display element having an uneven surface, which is a method for aligning a liquid crystal alignment film suitable for an industrial production process.

Japanese Patent No. 3893659

M. Shadt et al., Jpn. J. Appl. Phys. 31, 2155 (1992). K. Ichimura et al., Chem. Rev. 100, 1847 (2000).

  As described above, the photo-alignment method does not require a rubbing process as compared with a rubbing method that has been industrially used as an alignment treatment method for liquid crystal display elements, and thus has a great advantage. And compared with the rubbing method in which the alignment control ability becomes almost constant by rubbing, the photo alignment method can control the alignment control ability by changing the irradiation amount of polarized light. However, in the photo-alignment method, in order to achieve the same degree of alignment control ability as in the rubbing method, a large amount of polarized light irradiation may be required or stable liquid crystal alignment may not be realized. .

  For example, in the decomposition type photo-alignment method described in Patent Document 1, it is necessary to irradiate the polyimide film with ultraviolet light from a high-pressure mercury lamp with an output of 500 W for 60 minutes. Become. Even in the case of a dimerization type or photoisomerization type photo-alignment method, a large amount of ultraviolet irradiation of about several J (joule) to several tens of J may be required. Furthermore, in the case of the photo-crosslinking type or photoisomerization type photo-alignment method, since the thermal stability and light stability of the liquid crystal alignment are inferior, there is a problem that alignment failure or display burn-in occurs when a liquid crystal display element is used. was there. In particular, in a horizontal electric field drive type liquid crystal display element, since liquid crystal molecules are switched in a plane, alignment misalignment of liquid crystal after liquid crystal driving is likely to occur, and display burn-in caused by AC driving is a major issue.

  Therefore, in the photo-alignment method, there is a demand for higher efficiency of alignment treatment and realization of stable liquid crystal alignment, and liquid crystal alignment films and liquid crystals that can impart high alignment control ability to the liquid crystal alignment film with high efficiency. There is a need for aligning agents.

  The present invention provides a substrate having a liquid crystal alignment film for a horizontal electric field drive type liquid crystal display element which is provided with high efficiency and orientation control ability and has excellent image sticking characteristics, and a horizontal electric field drive type liquid crystal display element having the substrate. With the goal.

（式（１）中、Ｒ_１は１価の有機基であり、Ｒ_２〜Ｒ_５はそれぞれ独立に水素原子または１価の有機基であり、但しＲ_２およびＲ_３のうち少なくともひとつは１価の有機基であり、Ｒ_６は１価の有機基であり、ｍは０〜２の整数であり、ｎは０〜４の整数である。）
２．上記ジアミンとテトラカルボン酸二無水物との重合物であるポリイミド前駆体及びそのイミド化物であるポイミドからなる群から選ばれる少なくとも１種の重合体と、有機溶媒と、を含有する液晶配向剤。
３．上記ジアミンが、以下の式（２）で表される、上記１又は２に記載の液晶配向剤。

（式（２）中、Ｒ_１〜Ｒ_６、ｍおよびｎの定義は、上記式（１）と同様である。）
４．前記ポリイミド前駆体が、下記式（６）で表される上記１〜３のいずれかに記載の液晶配向剤。

（式（６）において、Ｘ_１はテトラカルボン酸誘導体に由来する４価の有機基であり、Ｙ_１は式（１）の構造を含むジアミンに由来する２価の有機基であり、Ｒ_１１は水素原子又は炭素数１〜５のアルキル基である。）
５．前記式（６）中、Ｘ_１の構造が下記構造中からなる群から選ばれる少なくとも１種である、上記４に記載の液晶配向剤。

６．前記式（６）で表される構造単位を有する重合体が、液晶配向剤に含有される全重合体に対して１０モル％以上含有される上記４又は５に記載の液晶配向剤。
７．上記有機溶媒中に、４−ヒドロキシ−４−メチル−２−ペンタノン及びジエチレングリコールジエチルエーテルからなる群から選ばれる少なくとも１種を含有する、上記４〜６のいずれかに記載の液晶配向剤。
８．［Ｉ］上記１乃至７のいずれかに記載の組成物を、横電界駆動用の導電膜を有する基板上に塗布して塗膜を形成する工程；
［ＩＩ］ ［Ｉ］で得られた塗膜に偏光した紫外線を照射する工程；及び
［ＩＩＩ］ ［ＩＩ］で得られた塗膜を加熱する工程；
を有することによって配向制御能が付与された横電界駆動型液晶表示素子用液晶配向膜を得る、前記液晶配向膜を有する基板の製造方法。
９．上記８に記載の方法により製造された横電界駆動型液晶表示素子用液晶配向膜を有する基板。
１０．上記９に記載の基板を有する横電界駆動型液晶表示素子。
１１．上記９記載の基板（第１の基板）を準備する工程；
［Ｉ’］ 第２の基板上に請求項１乃至７記載の組成物を、塗布して塗膜を形成する工程；
［ＩＩ’］ ［Ｉ’］で得られた塗膜に偏光した紫外線を照射する工程；
［ＩＩＩ’］ ［ＩＩ’］で得られた塗膜を加熱する工程；を有することによって配向制御能が付与された液晶配向膜を得る、前記液晶配向膜を有する第２の基板を得る工程；及び
［ＩＶ］ 液晶を介して前記第１及び第２の基板の液晶配向膜が相対するように、前記第１及び第２の基板を対向配置して液晶表示素子を得る工程；を有することにより、横電界駆動型液晶表示素子を得る、該液晶表示素子の製造方法。
１２．上記１１記載の方法により製造された横電界駆動型液晶表示素子。
１３．下記式（１）で表される構造を有するジアミンとテトラカルボン酸二無水物との重合物であるポリイミド前駆体及びそのイミド化物であるポリイミドからなる群から選ばれる少なくとも１種の重合体。

（式（１）中、Ｒ_１は１価の有機基であり、Ｒ_２〜Ｒ_５はそれぞれ独立に水素原子または１価の有機基であり、但しＲ_２およびＲ_３のうち少なくともひとつは１価の有機基であり、Ｒ_６は１価の有機基であり、ｍは０〜２の整数であり、ｎは０〜４の整数である。）
１４．上記ジアミンが、以下の式（２）で表される、上記１３に記載の重合体。

（式（２）中、Ｒ_１〜Ｒ_６、ｍおよびｎの定義は、上記式（１）と同様である。）
１５．前記ポリイミド前駆体が、下記式（６）で表される上記１３又は１４に記載の重合体。

（式（６）において、Ｘ_１はテトラカルボン酸誘導体に由来する４価の有機基であり、Ｙ_１は式（１）の構造を含むジアミンに由来する２価の有機基であり、Ｒ_１１は水素原子又は炭素数１〜５のアルキル基である。）
１６．前記式（６）中、Ｘ_１の構造が下記構造中からなる群から選ばれる少なくとも１種である、上記１５に記載の重合体。

１７．上記式（２）で表されるジアミン。 As a result of intensive studies to achieve the above problems, the present inventors have found the following invention.
1. The liquid crystal aligning agent containing the polymer obtained from the diamine which has a structure represented by following formula (1), and an organic solvent.

(In Formula (1), R ₁ is a monovalent organic group, R _{2 to} R ₅ are each independently a hydrogen atom or a monovalent organic group, provided that at least one of R ₂ and R ₃ is 1 R ₆ is a monovalent organic group, m is an integer of 0 to 2, and n is an integer of 0 to 4.)
2. A liquid crystal aligning agent comprising at least one polymer selected from the group consisting of a polyimide precursor that is a polymer of the diamine and tetracarboxylic dianhydride and a poimide that is an imidized product thereof, and an organic solvent.
3. 3. The liquid crystal aligning agent according to 1 or 2 above, wherein the diamine is represented by the following formula (2).

(In formula (2), the definitions of R _{1 to} R ₆ , m and n are the same as in formula (1) above.)
4). The liquid crystal aligning agent in any one of said 1-3 whose said polyimide precursor is represented by following formula (6).

(In Formula (6), X ₁ is a tetravalent organic group derived from a tetracarboxylic acid derivative, Y ₁ is a divalent organic group derived from a diamine containing the structure of Formula (1), and R ₁₁ Is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.)
5. 5. The liquid crystal aligning agent according to 4 above, wherein in formula (6), the structure of X ₁ is at least one selected from the group consisting of the following structures.

6). 6. The liquid crystal aligning agent according to 4 or 5 above, wherein the polymer having the structural unit represented by the formula (6) is contained in an amount of 10 mol% or more based on the total polymer contained in the liquid crystal aligning agent.
7). The liquid crystal aligning agent in any one of said 4-6 which contains at least 1 sort (s) chosen from the group which consists of 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether in the said organic solvent.
8). [I] A step of coating the composition according to any one of 1 to 7 above on a substrate having a conductive film for driving a lateral electric field to form a coating film;
[II] a step of irradiating the coating film obtained in [I] with polarized ultraviolet rays; and [III] a step of heating the coating film obtained in [II];
The manufacturing method of the board | substrate which has the said liquid crystal aligning film which obtains the liquid crystal aligning film for horizontal electric field drive type liquid crystal display elements by which orientation control ability was provided by having.
9. 9. A substrate having a liquid crystal alignment film for a lateral electric field drive type liquid crystal display device produced by the method described in 8 above.
10. 10. A lateral electric field drive type liquid crystal display device comprising the substrate according to 9 above.
11. Preparing a substrate (first substrate) according to 9 above;
[I ′] A step of coating the composition according to claim 1 on a second substrate to form a coating film;
[II ′] A step of irradiating the coating film obtained in [I ′] with polarized ultraviolet rays;
[III ′] a step of heating the coating film obtained in [II ′]; obtaining a liquid crystal alignment film having an alignment control ability by obtaining a second substrate having the liquid crystal alignment film; And [IV] obtaining a liquid crystal display element by disposing the first and second substrates so that the liquid crystal alignment films of the first and second substrates face each other through the liquid crystal. A method of manufacturing a liquid crystal display element, which obtains a horizontal electric field drive type liquid crystal display element.
12 12. A lateral electric field drive type liquid crystal display device manufactured by the method according to 11 above.
13. The at least 1 sort (s) of polymer chosen from the group which consists of the polyimide precursor which is a polymer of the diamine which has a structure represented by following formula (1), and tetracarboxylic dianhydride, and the imidized compound.

(In Formula (1), R ₁ is a monovalent organic group, R _{2 to} R ₅ are each independently a hydrogen atom or a monovalent organic group, provided that at least one of R ₂ and R ₃ is 1 R ₆ is a monovalent organic group, m is an integer of 0 to 2, and n is an integer of 0 to 4.)
14 14. The polymer according to 13, wherein the diamine is represented by the following formula (2).

(In formula (2), the definitions of R _{1 to} R ₆ , m and n are the same as in formula (1) above.)
15. The polymer according to the above 13 or 14, wherein the polyimide precursor is represented by the following formula (6).

(In Formula (6), X ₁ is a tetravalent organic group derived from a tetracarboxylic acid derivative, Y ₁ is a divalent organic group derived from a diamine containing the structure of Formula (1), and R ₁₁ Is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.)
16. 16. The polymer according to 15 above, wherein in the formula (6), the structure of X ₁ is at least one selected from the group consisting of the following structures.

17. Diamine represented by the above formula (2).

According to the present invention, there are provided a substrate having a liquid crystal alignment film for a horizontal electric field drive type liquid crystal display element which is provided with high efficiency and orientation control ability and has excellent image sticking characteristics, and a horizontal electric field drive type liquid crystal display element having the substrate. Can do.
Since the lateral electric field drive type liquid crystal display device manufactured by the method of the present invention is provided with the alignment control ability with high efficiency, the display characteristics are not impaired even when continuously driven for a long time.

  The polymer composition used in the production method of the present invention has a photosensitive main chain polymer (hereinafter, also simply referred to as main chain polymer) capable of expressing self-organization ability, and the polymer The coating film obtained by using the composition is a film having a photosensitive main chain type polymer that can exhibit self-organization ability. This coating film is subjected to orientation treatment by irradiation with polarized light without being rubbed. And after polarized light irradiation, it passes through the process of heating the main chain type polymer film, and becomes a coating film (hereinafter also referred to as a liquid crystal alignment film) to which alignment control ability is imparted. At this time, the slight anisotropy developed by the irradiation of polarized light becomes a driving force, and the main chain polymer itself is efficiently reoriented by self-organization. As a result, a highly efficient alignment process can be realized as a liquid crystal alignment film, and a liquid crystal alignment film with high alignment control ability can be obtained.

Hereinafter, embodiments of the present invention will be described in detail.
The liquid crystal aligning agent of the present invention is a liquid crystal aligning agent containing a polymer obtained from a diamine having a structure represented by the following formula (1) (hereinafter also referred to as a specific polymer or a main chain polymer). . Hereinafter, each condition will be described in detail.

上記式（１）中、Ｒ_１は１価の有機基であり、Ｒ_２〜Ｒ_５はそれぞれ独立に水素原子または１価の有機基であり、但しＲ_２およびＲ_３のうち少なくともひとつは１価の有機基であり、Ｒ_６は１価の有機基であり、ｍは０〜２の整数であり、ｎは０〜４の整数である。ここにおける１価の有機基としては、炭素数が１〜１０、好ましくは１〜３を有する、アルキル基、アルケニル基、アルコキシ基、フルオロアルキル基、フルオロアルケニル基、若しくはフルオロアルコキシ基が挙げられる。なかでも、１価の有機基としては、メチル基が好ましい。 <Diamine having a specific structure>
The liquid crystal aligning agent of the present invention is a liquid crystal aligning agent containing a polymer obtained from a diamine having the structure of the following formula (1) (also referred to as a specific diamine in the present invention) and an organic solvent.

In the above formula (1), R ₁ is a monovalent organic group, and R _{2 to} R ₅ are each independently a hydrogen atom or a monovalent organic group, provided that at least one of R ₂ and R ₃ is 1 R ₆ is a monovalent organic group, m is an integer of 0 to 2, and n is an integer of 0 to 4. Examples of the monovalent organic group include an alkyl group, an alkenyl group, an alkoxy group, a fluoroalkyl group, a fluoroalkenyl group, or a fluoroalkoxy group having 1 to 10, preferably 1 to 3 carbon atoms. Especially, as a monovalent organic group, a methyl group is preferable.

（式（２）中、Ｒ_１〜Ｒ_６、ｍおよびｎの定義は、上記式（１）と同様である。） As said diamine, the diamine represented by the following formula | equation (2) is preferable.

(In formula (2), the definitions of R _{1 to} R ₆ , m and n are the same as in formula (1) above.)

Although the following can be illustrated as a specific example of the diamine which has a structure of the said Formula (2), it is not limited to these.

式（３）中、Ｒ_１〜Ｒ_６、ｍおよびｎの定義は、上記式（１）と同様である <Method for synthesizing specific diamine>
The method for synthesizing the specific diamine is not particularly limited. For example, the method of using the dinitro compound represented by following formula (3), and converting the nitro group which it has into an amino group by a reductive reaction is mentioned.

In the formula (3), the definitions of R _{1 to} R ₆ , m and n are the same as those in the above formula (1).

The catalyst used for the reduction reaction is preferably an activated carbon-supported metal available as a commercial product, and examples thereof include palladium-activated carbon, platinum-activated carbon, and rhodium-activated carbon. Further, palladium catalyst, platinum oxide, Raney nickel, iron, zinc, tin, and the like are not necessarily activated carbon-supporting metal catalysts. In general, iron, zinc, and tin that are widely used are preferable because good results can be obtained.

In order to make the reduction reaction proceed more effectively, the reaction may be carried out in the presence of activated carbon. At this time, the amount of the activated carbon to be used is not particularly limited, but is preferably in the range of 1 to 30% by mass and more preferably 10 to 20% by mass with respect to the dinitro compound X1. For the same reason, the reaction may be carried out under pressure. In this case, in order to avoid reduction of benzene nuclei, it is carried out in a pressure range up to 20 atm. The reaction is preferably carried out in the range up to 10 atm. If necessary, an acid catalyst may be added to shorten the time.

If a solvent does not react with each raw material, it can be used without a restriction | limiting. 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 (pentane, Hexane, heptane, petroleum ether, etc.); aromatic hydrocarbons (benzene, toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene, nitrobenzene, tetralin, etc.); halogenated hydrocarbons (chloroform, dichloromethane, carbon tetrachloride, dichloroethane) Lower fatty acid esters (methyl acetate, ethyl acetate, butyl acetate, methyl propionate, etc.); nitriles (acetonitrile, propionitrile, butyronitrile, etc.); protic solvent polar organic solvent (methanol, ethanol, H ₂ O, etc.) Etc.) can be used. These solvents can be appropriately selected in consideration of the ease of reaction and the like, and can be used singly or in combination of two or more. If necessary, the solvent can be dried using a suitable dehydrating agent or desiccant and used as a non-aqueous solvent.

Although the usage-amount (reaction concentration) of a solvent is not specifically limited, It is 0.1-100 mass times with respect to a dinitro compound. Preferably it is 0.5-30 mass times, More preferably, it is 1-10 mass times.
Although reaction temperature is not specifically limited, It is the range from -100 degreeC to the boiling point of the solvent to be used, Preferably, it is -50-150 degreeC. The reaction time is usually 0.05 to 350 hours, preferably 0.5 to 100 hours.

[Production method of formula (3)]
The method for synthesizing the compound of the formula (3) is not particularly limited. For example, a cinnamic acid derivative represented by the following formula (4) is converted into a chloride with thionyl chloride or the like, and then represented by the formula (5). Or a cinnamic acid derivative represented by the following formula (4) is reacted with a nitrophenol compound represented by the following formula (5) in the presence of a condensing agent. The method of doing is mentioned.

The amount of the reaction substrate may be 1 to 10 equivalents of the compound represented by the general formula (5) or 1 equivalent to the chloride represented by the compound represented by the general formula (4).

  The condensing agent is not particularly limited as long as it is used for ordinary ester synthesis. For example, Mukaiyama reagent (2-chloro-N-methylpyridinium iodide), DCC (1,3-dicyclohexylcarbodiimide), EDC ( 1-ethyl-3- (3-dimethylaminopropyl) -carbodiimide hydrochloride), CDI (carbonyldiimidazole), dimethylpropynylsulfonium bromide, propargyltriphenylphosphonium bromide, DEPC (diethyl cyanophosphate), etc. 1 to 4 equivalents relative to the compound represented by

  In the case of using a solvent, the solvent to be used is not particularly limited as long as it does not inhibit the progress of the reaction. For example, aromatic hydrocarbons such as benzene, toluene and xylene, and aliphatic hydrocarbons such as hexane and heptane. , Cycloaliphatic alicyclic hydrocarbons, chlorobenzene, dichlorobenzene and other aromatic halogenated hydrocarbons, dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene Aliphatic halogenated hydrocarbons such as diethyl ether, t-butyl methyl ether, ethers such as 1,2-dimethoxyethane, tetrahydrofuran and 1,4-dioxane, esters such as ethyl acetate and ethyl propionate, N , N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pi Examples include amides such as loridone, amines such as triethylamine, tributylamine and N, N-dimethylaniline, pyridines such as pyridine and picoline, acetonitrile and dimethyl sulfoxide. These solvents may be used alone or as a mixture of two or more thereof.

  It is not always necessary to add a base, but when a base is used, for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, an alkali metal carbonate such as sodium carbonate or potassium carbonate, sodium hydrogen carbonate, or potassium hydrogen carbonate. Alkali metal bicarbonates such as triethylamine, tributylamine, N, N-dimethylaniline, pyridine, 4- (dimethylamino) pyridine, imidazole, 1,8-diazabicyclo [5,4,0] -7-undecene, etc. An organic base etc. can be used for 1-4 equivalent with respect to the compound represented by General formula (4).

  The reaction temperature can be set to an arbitrary temperature from −60 ° C. to the reflux temperature of the reaction mixture, and the reaction time varies depending on the concentration of the reaction substrate and the reaction temperature, but is usually arbitrarily within the range of 5 minutes to 100 hours. Can be set.

  In general, for example, 1 to 10 equivalents of the compound represented by the general formula (5) and 1 to 4 equivalents of WSC (1-ethyl-3-ethyl) with respect to 1 equivalent of the compound represented by the general formula (4). (3-dimethylaminopropyl) -carbodiimide hydrochloride), CDI (carbonyldiimidazole) and other condensing agents. If necessary, 1-4 equivalents of potassium carbonate, triethylamine, pyridine, 4- (dimethylamino) pyridine, etc. In the presence of a base, the reaction is carried out for 10 minutes to 24 hours using no solvent or a solvent such as dichloromethane, chloroform, diethyl ether, tetrahydrofuran, 1,4-dioxane, etc., in the range of 0 ° C. to the reflux temperature of these solvents. Is preferred.

上記式（６）において、Ｘ_１はテトラカルボン酸誘導体に由来する４価の有機基であり、Ｙ_１は式（１）の構造を含むジアミンに由来する２価の有機基であり、Ｒ_１１は水素原子又は炭素数１〜５のアルキル基である。Ｒ_１１は、加熱によるイミド化のしやすさの点から、水素原子、メチル基又はエチル基が好ましい。 <Polymer>
The polymer of the present invention is a polymer obtained using the diamine. Specific examples include polyamic acid, polyamic acid ester, polyimide, polyurea, polyamide and the like. From the viewpoint of use as a liquid crystal aligning agent, a polyimide precursor containing a structural unit represented by the following formula (6), And at least one selected from polyimides as imidized products thereof.

In the above formula (6), X ₁ is a tetravalent organic group derived from a tetracarboxylic acid derivative, Y ₁ is a divalent organic group derived from a diamine containing the structure of formula (1), and R ₁₁ Is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R ₁₁ is preferably a hydrogen atom, a methyl group or an ethyl group from the viewpoint of ease of imidization by heating.

<Tetracarboxylic dianhydride>
X ₁ is a tetravalent organic group derived from a tetracarboxylic acid derivative, and its structure is not particularly limited. X ₁ in the polyimide precursor is required for the solubility of the polymer in the solvent, the coating property of the liquid crystal aligning agent, the orientation of the liquid crystal when it is used as the liquid crystal alignment film, the voltage holding ratio, the accumulated charge, etc. Depending on the degree of the properties to be selected, one type may be used in the same polymer, or two or more types may be mixed.
If Specific examples of X ₁ dare shown, it is published in paragraph 13 to 14, wherein the WO 2015/119168, such as the structure of formula (X-1) ~ (X -46) are mentioned.

Below, shows the structure of a preferred X _1, the present invention is not limited thereto.

Of the above structures, (A-1) and (A-2) are particularly preferable from the viewpoint of further improving rubbing resistance, and (A-4) is particularly preferable from the viewpoint of further improving the relaxation rate of accumulated charge. , (A-15) to (A-17) are particularly preferred from the standpoint of further improving the liquid crystal orientation and the rate of relaxation of accumulated charges.

<Diamine>
In Formula (6), specific examples of Y ₁ include a structure in which two amino groups are removed from the diamine of Formula (1). Among these, Y ₁ is particularly preferably a structure obtained by removing two amino groups from the structures of the above formulas (1-1) and (1-2).

式（７）において、Ｘ_２はテトラカルボン酸誘導体に由来する４価の有機基であり、Ｙ_２は式（１）の構造を主鎖方向に含まないジアミンに由来する２価の有機基であり、Ｒ_１２は、前記式（６）のＲ_１１の定義と同じであり、Ｒ_２２は水素原子又は炭素数１〜４のアルキル基を表す。また、２つあるＲ_２２の少なくとも一方は水素原子であることが好ましい。 <Polymer (other structural units)>
The polyimide precursor containing the structural unit represented by the formula (6) is at least selected from the structural unit represented by the following formula (7) and a polyimide that is an imidized product thereof, as long as the effects of the present invention are not impaired. One kind may be included.

In Formula (7), X ₂ is a tetravalent organic group derived from a tetracarboxylic acid derivative, and Y ₂ is a divalent organic group derived from a diamine that does not include the structure of Formula (1) in the main chain direction. Yes, R ₁₂ is the same as the definition of R _{11 in} the formula (6), and R ₂₂ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Moreover, it is preferable that at least one of two R < ₂₂ > is a hydrogen atom.

Specific examples of X ₂ include the same structures as those exemplified for X ₁ in formula (6), including preferred examples. Y ₂ in the polyimide precursor is a divalent organic group derived from a diamine that does not include the structure of formula (1) in the main chain direction, and the structure is not particularly limited. Y ₂ depends on the degree of required properties such as the solubility of the polymer in the solvent, the coating property of the liquid crystal aligning agent, the orientation of the liquid crystal when it is used as the liquid crystal alignment film, the voltage holding ratio, and the accumulated charge. 1 type may be selected in the same polymer, and 2 or more types may be mixed.

If you dare Specific examples of Y _2, the structure of the formulas listed in item 4 of WO 2015/119168 (2), and is published in 12 paragraphs 8 wherein the formula (Y-1) ~ Structures of (Y-97) and (Y-101) to (Y-118); a divalent organic compound obtained by removing two amino groups from formula (2), which is described in paragraph 6 of International Publication No. 2013/008906 Group: a divalent organic group obtained by removing two amino groups from formula (1) published in paragraph 8 of International Publication No. 2015/122413; formula (3) published in paragraph 8 of International Publication No. 2015/060360 A divalent organic group obtained by removing two amino groups from formula (1) described in paragraph 8 of Japanese Patent Application Publication No. 2012-173514; a formula published in paragraph 9 of International Publication No. 2010-050523 (A)-(F) is a divalent product obtained by removing two amino groups Organic groups, and the like.

Are shown below, but the preferred Y ₂ structure, the present invention is not limited thereto.

Among the above structures, (B-28), (B-29) and the like are particularly preferable from the viewpoint of further improving rubbing resistance, and (B-1) to (B-3) and the like are liquid crystal alignment properties. From the viewpoint of further improvement, (B-14) to (B-18), (B-27), (B-31), (B-32) and the like are further improved in the rate of relaxation of accumulated charges. (B-26) and the like are particularly preferable from the viewpoint of further improving the voltage holding ratio.
When the polyimide precursor containing the structural unit represented by Formula (6) includes the structural unit represented by Formula (7) at the same time, the structural unit represented by Formula (6) is represented by Formula (6) and Formula It is preferable that it is 10 mol% or more with respect to the sum total of (7), More preferably, it is 20 mol% or more, Most preferably, it is 30 mol% or more.

The molecular weight of the polyimide precursor used in the present invention is preferably 2,000 to 500,000 in terms of weight average molecular weight, more preferably 5,000 to 300,000, and still more preferably 10,000 to 100,000. is there.
Examples of the polyimide having a divalent group represented by the formula (1) in the main chain include a polyimide obtained by ring-closing the polyimide precursor. In this polyimide, the ring closure rate (also referred to as imidation rate) of the amic acid group is not necessarily 100%, and can be arbitrarily adjusted according to the use and purpose.
Examples of the method for imidizing the polyimide precursor include thermal imidization in which the polyimide precursor solution is heated as it is, or catalytic imidization in which a catalyst is added to the polyimide precursor solution.

<Liquid crystal aligning agent>
Although the liquid crystal aligning agent of this invention contains the polymer (specific polymer) obtained from the diamine which has a structure represented by Formula (1), it differs in the limit which has an effect as described in this invention. Two or more specific polymers having a structure may be contained. Moreover, in addition to a specific polymer, you may contain the other polymer, ie, the polymer which does not have a bivalent group represented by Formula (1). Other polymer types include polyamic acid, polyimide, polyamic acid ester, polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivative, polyacetal, polystyrene or derivatives thereof, poly (styrene-phenylmaleimide) derivative, poly (meta ) Acrylate and the like. When the liquid crystal aligning agent of this invention contains another polymer, it is preferable that the ratio of the specific polymer with respect to all the polymer components is 5 mass% or more, and 5-95 mass% is mentioned as the example.

The liquid crystal aligning agent is used for producing a liquid crystal aligning film, and generally takes the form of a coating liquid from the viewpoint of forming a uniform thin film. Also in the liquid crystal aligning agent of this invention, it is preferable that it is a coating liquid containing an above-described polymer component and the organic solvent in which this polymer component is dissolved. At that time, the concentration of the polymer in the liquid crystal aligning agent can be appropriately changed by setting the thickness of the coating film to be formed. From the viewpoint of forming a uniform and defect-free coating film, the content is preferably 1% by mass or more, and from the viewpoint of storage stability of the solution, it is preferably 10% by mass or less. A particularly preferable concentration of the polymer is 2 to 8% by mass.

  The organic solvent contained in the liquid crystal aligning agent is not particularly limited as long as the polymer component is uniformly dissolved. Specific examples include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, 1,3-dimethyl. -Imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone and the like can be mentioned. Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, or γ-butyrolactone is preferably used.

  Moreover, the organic solvent contained in the liquid crystal aligning agent uses a mixed solvent that is used in combination with a solvent that improves the coating properties and the surface smoothness of the coating film when the liquid crystal aligning agent is applied in addition to the above-described solvents. Such a mixed solvent is also preferably used in the liquid crystal aligning agent of the present invention. Specific examples of the organic solvent to be used in combination are given below, but the organic solvent is not limited to these examples.

式［Ｄ−１］中、Ｄ^１は炭素数１〜３のアルキル基を示し、式［Ｄ−２］中、Ｄ^２は炭素数１〜３のアルキル基を示し、式［Ｄ−３］中、Ｄ^３は炭素数１〜４のアルキル基を示す。 For example, 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, 1,2- Etanji 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentane Diol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 2-pe Thanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate , Ethylene glycol diacetate, propylene carbonate, ethylene carbonate, 2- (methoxymethoxy) ethanol, 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, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono Butyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2- (2-ethoxyethoxy) ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene glycol Ethylene glycol monomethyl ether, Liethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, 3-ethoxypropionic acid Methyl ethyl, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl lactate, ethyl lactate, n-propyl lactate, Examples thereof include lactic acid n-butyl ester, lactic acid isoamyl ester, and solvents represented by the following formulas [D-1] to [D-3].

In the formula [D-1], D ¹ represents an alkyl group having 1 to 3 carbon atoms. In the formula [D-2], D ² represents an alkyl group having 1 to 3 carbon atoms. The formula [D-3] Among them, D ³ represents an alkyl group having 1 to 4 carbon atoms.

Among them, 1-hexanol, cyclohexanol, 1,2-ethanediol, 1,2-propanediol, propylene glycol monobutyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monobutyl ether or It is preferable to use dipropylene glycol dimethyl ether. The kind and content of such a solvent are appropriately selected according to the application device, application conditions, application environment, and the like of the liquid crystal aligning agent.

  The liquid crystal aligning agent of this invention may contain additionally components other than a polymer component and an organic solvent in the range which does not impair the effect of this invention. Examples of such additional components include an adhesion aid for increasing the adhesion between the liquid crystal alignment film and the substrate and the adhesion between the liquid crystal alignment film and the sealing material, a crosslinking agent for increasing the strength of the liquid crystal alignment film, and the liquid crystal alignment. Examples thereof include dielectrics and conductive materials for adjusting the dielectric constant and electric resistance of the film. Specific examples of these additional components are as disclosed in various known literatures relating to liquid crystal aligning agents. However, if an example is given, pages 53 [0105] to 55 of the pamphlet of Japanese Unexamined Patent Publication No. 2015/060357. And the like as disclosed in [0116].

<Manufacturing method of substrate having liquid crystal alignment film> and <Manufacturing method of liquid crystal display element>
The method for producing a substrate having the liquid crystal alignment film of the present invention is as follows.
[I] (A) A polymer composition containing a photosensitive main chain polymer and (B) an organic solvent is applied onto a substrate having a conductive film for driving a lateral electric field to form a coating film. Process;
[II] a step of irradiating the coating film obtained in [I] with polarized ultraviolet rays; and [III] a step of heating the coating film obtained in [II];
Have
Through the above steps, a liquid crystal alignment film for a lateral electric field drive type liquid crystal display element to which alignment control ability is imparted can be obtained, and a substrate having the liquid crystal alignment film can be obtained.

Further, by preparing a second substrate in addition to the obtained substrate (first substrate), a lateral electric field drive type liquid crystal display element can be obtained.
The second substrate is replaced with a substrate having no lateral electric field driving conductive film instead of a substrate having no lateral electric field driving conductive film, except that the above steps [I] to [III] (lateral electric field driving For the sake of convenience, the substrate having no conductive film is sometimes referred to as processes [I ′] to [III ′] in some cases for the sake of convenience. Two substrates can be obtained.

The manufacturing method of the horizontal electric field drive type liquid crystal display element is:
[IV] A step of obtaining a liquid crystal display element by arranging the first and second substrates obtained above so that the liquid crystal alignment films of the first and second substrates face each other with liquid crystal interposed therebetween;
Have Thereby, a horizontal electric field drive type liquid crystal display element can be obtained.

Hereinafter, each step [I] to [III] and [IV] of the production method of the present invention will be described.
<Process [I]>
In step [I], a polymer composition containing a photosensitive main polymer and an organic solvent is applied to a substrate having a conductive film for driving a lateral electric field to form a coating film.

<Board>
Although it does not specifically limit about a board | substrate, When the liquid crystal display element manufactured is a transmission type, it is preferable that a highly transparent board | substrate is used. In that case, there is no particular limitation, and a glass substrate or a plastic substrate such as an acrylic substrate or a polycarbonate substrate can be used.
In consideration of application to a reflective liquid crystal display element, an opaque substrate such as a silicon wafer can also be used.

<Conductive film for driving lateral electric field>
The substrate has a conductive film for driving a lateral electric field.
Examples of the conductive film include, but are not limited to, ITO (Indium Tin Oxide) and IZO (Indium Zinc Oxide) when the liquid crystal display element is a transmission type.
In the case of a reflective liquid crystal display element, examples of the conductive film include, but are not limited to, a material that reflects light such as aluminum.
As a method for forming a conductive film on a substrate, a conventionally known method can be used.

The method for applying the polymer composition described above onto a substrate having a conductive film for driving a lateral electric field is not particularly limited.
In general, the application method is generally performed by screen printing, offset printing, flexographic printing, an inkjet method, or the like. Other coating methods include a dipping method, a roll coater method, a slit coater method, a spinner method (rotary coating method), or a spray method, and these may be used depending on the purpose.

After the polymer composition is applied on the substrate having the conductive film for driving the transverse electric field, it is 50 to 300 ° C., preferably 50 to 300 ° C. by a heating means such as a hot plate, a thermal circulation oven or an IR (infrared) oven. The film can be obtained by evaporating the solvent at 180 ° C. The drying temperature at this time is preferably lower than that in the step [III] from the viewpoint of liquid crystal alignment stability.
If the thickness of the coating film is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may be lowered. It is.
In addition, it is also possible to provide the process of cooling the board | substrate with which the coating film was formed to room temperature after the [I] process and before the following [II] process.

<Process [II]>
In step [II], the coating film obtained in step [I] is irradiated with polarized ultraviolet rays. When irradiating the surface of the coating film with polarized ultraviolet rays, the substrate is irradiated with polarized ultraviolet rays through a polarizing plate from a certain direction. As the ultraviolet rays to be used, ultraviolet rays having a wavelength in the range of 100 nm to 400 nm can be used. Preferably, the optimum wavelength is selected through a filter or the like depending on the type of coating film to be used. For example, ultraviolet rays having a wavelength in the range of 290 nm to 400 nm can be selected and used so that a photocrosslinking reaction or a photoisomerization reaction can be selectively induced. As the ultraviolet light, for example, light emitted from a high-pressure mercury lamp or a metal halide lamp can be used.

  The irradiation amount of polarized ultraviolet rays depends on the coating film used. The amount of irradiation is polarized ultraviolet light that realizes the maximum value of ΔA (hereinafter also referred to as ΔAmax), which is the difference between the ultraviolet light absorbance in a direction parallel to the polarization direction of polarized ultraviolet light and the ultraviolet light absorbance in a direction perpendicular to the polarization direction of the polarized ultraviolet light. The amount is preferably in the range of 1% to 70%, more preferably in the range of 1% to 50%.

<Step [III]>
In step [III], the ultraviolet-irradiated coating film polarized in step [II] is heated. An orientation control ability can be imparted to the coating film by heating.
For heating, a heating means such as a hot plate, a heat circulation type oven, or an IR (infrared) type oven can be used. The heating temperature can be determined in consideration of the temperature at which good liquid crystal alignment stability and electrical characteristics are exhibited in the coating film used.

  The heating temperature is preferably within a temperature range in which the main chain polymer exhibits good liquid crystal alignment stability. If the heating temperature is too low, the anisotropy effect due to heat tends to be insufficient, and if the heating temperature is too higher than the temperature range, the anisotropy imparted by polarization exposure will disappear. In this case, it may be difficult to reorient in one direction due to self-organization.

  The thickness of the coating film formed after heating is preferably 5 nm to 300 nm, more preferably 50 nm to 150 nm, for the same reason described in the step [I].

  By having the above steps, the production method of the present invention can realize highly efficient introduction of anisotropy into the coating film. And a board | substrate with a liquid crystal aligning film can be manufactured highly efficiently.

<Process [IV]>
The [IV] step is the same as [I ′] to [III ′] in the same manner as the substrate (first substrate) obtained in [III] and having a liquid crystal alignment film on the conductive film for driving a lateral electric field. The liquid crystal cell is obtained by a known method by arranging the liquid crystal alignment film-provided substrate (second substrate) obtained in the above step so that both liquid crystal alignment films face each other through the liquid crystal. To produce a lateral electric field drive type liquid crystal display element. The steps [I ′] to [III ′] are the same as the steps [I] except that a substrate having no lateral electric field driving conductive film is used instead of the substrate having the lateral electric field driving conductive film. It can carry out similarly to process [I]-[III]. Since the difference between the steps [I] to [III] and the steps [I ′] to [III ′] is only the presence or absence of the conductive film, the description of the steps [I ′] to [III ′] is omitted. To do.

  To give an example of the production of a liquid crystal cell or a liquid crystal display element, the first and second substrates described above are prepared, spacers are dispersed on the liquid crystal alignment film of one substrate, and the liquid crystal alignment film surface is on the inside. In this way, the other substrate is bonded and the liquid crystal is injected under reduced pressure, or the liquid crystal is dropped on the liquid crystal alignment film surface on which the spacers are dispersed, and then the substrate is bonded and sealed. , Etc. can be illustrated. At this time, it is preferable to use a substrate having an electrode having a structure like a comb for driving a horizontal electric field as the substrate on one side. The spacer diameter at this time is preferably 1 μm to 30 μm, more preferably 2 μm to 10 μm. This spacer diameter determines the distance between the pair of substrates that sandwich the liquid crystal layer, that is, the thickness of the liquid crystal layer.

The manufacturing method of the board | substrate with a coating film of this invention irradiates the polarized ultraviolet-ray, after apply | coating a polymer composition on a board | substrate and forming a coating film. Next, by heating, high-efficiency anisotropy is introduced into the main chain polymer film, and a substrate with a liquid crystal alignment film having a liquid crystal alignment control ability is manufactured.
In the coating film used in the present invention, the introduction of highly efficient anisotropy into the coating film is realized by utilizing the principle of molecular reorientation induced by self-assembly based on the photoreaction of the main chain. In the production method of the present invention, in the case of a structure having a photocrosslinkable group as a photoreactive group in the main chain type polymer, after forming a coating film on the substrate using the main chain type polymer, After irradiation and then heating, a liquid crystal display element is formed.

  Therefore, the coating film used in the method of the present invention is a liquid crystal alignment film having anisotropy introduced with high efficiency and excellent alignment control ability by sequentially performing irradiation of polarized ultraviolet rays on the coating film and heat treatment. can do.

  And in the coating film used for the method of this invention, the irradiation amount of the polarized ultraviolet-ray to a coating film, and the heating temperature in heat processing are optimized. Thereby, introduction of anisotropy into the coating film with high efficiency can be realized.

  The optimum irradiation amount of polarized ultraviolet rays for introducing highly efficient anisotropy into the coating film used in the present invention is such that the photosensitive group undergoes photocrosslinking reaction, photoisomerization reaction, or photofries rearrangement reaction in the coating film. Corresponds to the irradiation amount of polarized ultraviolet rays to optimize the amount. As a result of irradiating the coating film used in the present invention with polarized ultraviolet rays, if the number of photosensitive groups that undergo photocrosslinking reaction, photoisomerization reaction, or photofries rearrangement reaction is small, a sufficient photoreaction amount cannot be obtained. In that case, sufficient self-organization does not proceed even after heating. On the other hand, as a result of irradiating polarized ultraviolet light to the structure having a photocrosslinkable group in the coating film used in the present invention, the crosslinking reaction between the reactive groups proceeds when an excess of the photosensitive group that undergoes a crosslinking reaction occurs. It will be too much. In that case, the resulting film may become rigid and hinder the progress of self-assembly by subsequent heating. In addition, when the coating film used in the present invention is irradiated with polarized ultraviolet rays to a structure having a light fleece rearrangement group, the anisotropy obtained by polarized ultraviolet rays is increased when there are a large number of light fleece transition groups in the polymer film. It becomes smaller, and the stability of the liquid crystal alignment is lowered due to the hindrance to the progress of self-organization by subsequent heating, and if the amount of UV irradiation is too large, the photosensitivity is photodegraded and the self-organization by subsequent heating The quality of the liquid crystal display element may be deteriorated due to the hindrance to the progress or the deterioration of the electrical characteristics of the obtained liquid crystal alignment film.

  Therefore, in the coating film used in the present invention, the optimum amount of the photosensitive group that undergoes photocrosslinking reaction, photoisomerization reaction, or photofries rearrangement reaction by irradiation with polarized ultraviolet rays is 0.1 mol% of the polymer film. It is preferable to make it -90 mol%, and it is more preferable to set it as 0.1 mol%-80 mol%. By setting the amount of the photoreactive photosensitive group within such a range, the self-organization in the subsequent heat treatment proceeds efficiently, and it becomes possible to form highly efficient anisotropy in the film.

  In the coating film used in the method of the present invention, by optimizing the irradiation amount of polarized ultraviolet rays, the amount of photocrosslinking reaction, photoisomerization reaction, or photofleece rearrangement reaction of the photosensitive group in the main chain of the polymer film is reduced. Optimize. Then, in combination with the subsequent heat treatment, highly efficient introduction of anisotropy into the coating film used in the present invention is realized. In that case, a suitable amount of polarized ultraviolet rays can be determined based on the evaluation of ultraviolet absorption of the coating film used in the present invention.

  That is, the ultraviolet absorption in the direction parallel to the polarization direction of polarized ultraviolet light and the ultraviolet absorption in the vertical direction after irradiation with polarized ultraviolet light are measured for the coating film used in the present invention. From the measurement result of ultraviolet absorption, ΔA, which is the difference between the ultraviolet absorbance in the direction parallel to the polarization direction of polarized ultraviolet rays and the ultraviolet absorbance in the direction perpendicular to the polarization direction of the polarized ultraviolet rays, is evaluated. Then, the maximum value of ΔA (ΔAmax) realized in the coating film used in the present invention and the irradiation amount of polarized ultraviolet light that realizes it are obtained. In the production method of the present invention, a preferable amount of polarized ultraviolet rays to be irradiated in the production of the liquid crystal alignment film can be determined on the basis of the amount of polarized ultraviolet rays to realize this ΔAmax.

  As described above, in the production method of the present invention, in order to achieve highly efficient anisotropy introduction into the coating film, the above-described main chain type polymer provides liquid crystal alignment stability as a reference, as described above. A suitable heating temperature should be determined. Therefore, for example, the temperature range in which the main chain polymer used in the present invention provides liquid crystal alignment stability is determined in consideration of the temperature at which good liquid crystal alignment stability and electrical characteristics are exhibited in the coating film used. And can be set in a temperature range according to a liquid crystal alignment film made of a conventional polyimide or the like. That is, the heating temperature after irradiation with polarized ultraviolet rays is preferably 100 ° C to 300 ° C, and more preferably 150 ° C to 250 ° C. By doing so, greater anisotropy is imparted to the coating film used in the present invention.

  By doing so, the liquid crystal display element provided by the present invention exhibits high reliability against external stresses such as light and heat.

  As described above, the lateral electric field drive type liquid crystal display element substrate manufactured using the polymer of the present invention or the lateral electric field drive type liquid crystal display element having the substrate has excellent reliability and a large screen. And can be suitably used for high-definition liquid crystal televisions. In addition, since the liquid crystal alignment film manufactured by the method of the present invention has excellent liquid crystal alignment stability and reliability, it can be used for a variable phase shifter using liquid crystal. For example, it can be suitably used for an antenna that can vary the resonance frequency.

Abbreviations and structures of diamine compounds used in the examples are shown below.
<Diamine compound>
DA-1 is a novel compound that has not been disclosed yet, and its synthesis method will be described in detail in Synthesis Example 1 below.
Since DA-2 is a known compound in the literature, the target compound was synthesized by a known synthesis method such as JP-T 2009-517716.

The abbreviations of organic solvents used in Examples and the like are as follows.
THF: tetrahydrofuran.
DMF: N, N-dimethylformamide.
EtOH: ethanol.
MeOH: methanol.
AcOEt: ethyl acetate.
Hexane: hexane.
NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve

<Measurement of ¹ HNMR>
Apparatus: Fourier transform type superconducting nuclear magnetic resonance apparatus (FT-NMR) “INOVA-400” (manufactured by Varian) 400 MHz.
Solvent: deuterated N, N-dimethyl sulfoxide ([D ₆ ] -DMSO).
Standard substance: Tetramethylsilane (TMS).
<Measurement of viscosity>
In the synthesis example, the viscosity of the polymer solution was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.), a sample amount of 1.1 mL, cone rotor TE-1 (1 ° 34 ′, R24), temperature 25 Measured at ° C.

(Synthesis Example 1)
Synthesis of [DA-1]:

A 1 L four-necked flask was charged with 4-nitrocinnamic acid (50.0 g, 259 mmol), 4-nitro-o-cresol (39.6 g, 259 mmol) and THF (500 g), purged with nitrogen, and at room temperature. Stir. Subsequently, EDC (74.4 g, 388 mmol) and DMAP (3.2 g, 26 mmol) were charged, purged with nitrogen, and stirred at room temperature. After completion of the reaction, the reaction solution was poured into pure water (1500 mL), the precipitate was filtered off, and the resulting crude product was repulp washed with MeOH (1500 g) at room temperature and dried under reduced pressure [DA-1- 1] was obtained (yield 92%).

In a 2 L four-necked flask, [DA-1-1] (78.2 g, 259 mmol), DMF (900 g), EtOH (450 g), Fe (66.5 g, 1191 mmol), 10 wt% NH ₄ Cl aqueous solution (382. 2 g, 714 mmol) and 35% HCl (12.4 g, 119 mmol) were charged, purged with nitrogen, and stirred at 60 ° C. After completion of the reaction, Fe was filtered off with a Buchner funnel and washed with DMF. The filtrate was made weakly basic with saturated aqueous NaHCO ₃ and then poured into AcOEt (1000 g) to remove the aqueous layer. The obtained organic layer was washed with pure water, dried over sodium sulfate, and concentrated. The obtained crude product was isolated by silica gel column chromatography (AcOEt: Hexane = 2: 1 volume ratio) to obtain 40.26 g (yield 63%) of [DA-1].
The results of 1H-NMR of the target product are shown below. From this result, it was confirmed that the obtained solid was the target [DA-1].
1H NMR (400 MHz, [D ₆ ] -DMSO): δ7.60-7.64 (d, 1H), 7.43-7.45 (d, 2H), 6.67-6.69 (d, 1H), 6.56-6.58 (d, 2H ), 6.37-6.44 (m, 3H), 5.85 (s, 2H), 4.93 (s, 2H), 1.96 (s, 3H),

Polymerization example, alignment agent preparation example <Polyamic acid synthesis example 1>
NMP (164 g) and DA-1 (50.0 mmol, 13.4 g) were added to a 300 mL four-necked flask equipped with a stirrer and a nitrogen introduction tube, and stirred at room temperature until completely dissolved. C-1 (45 0.5 mmol, 8.9 g) was added and stirred at room temperature for 6 hours to obtain a polyamic acid solution. The viscosity of the polyamic acid solution at a temperature of 25 ° C. was 940 mPa · s. 26 g of the obtained polyamic acid solution was collected, 28.6 g of NMP and 23.4 g of BCS were added and stirred at room temperature for 2 hours to obtain a liquid crystal aligning agent (A1).

<Synthesis Example 2 of polyamic acid>
NMP (93.3 g) and DA-1 (50.0 mmol, 13.4 g) were added to a 300 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and stirred at room temperature until completely dissolved. (7.5 mmol, 1.9 g) was added and stirred at 60 ° C. for 2 hours. After cooling to room temperature, C-1 (41.0 mmol, 8.0 g) was added and stirred at room temperature for 6 hours to obtain a polyamic acid solution. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 319 mPa · s.
20 g of the resulting polyamic acid solution was collected, 50.0 g of NMP and 30.0 g of BCS were added, and the mixture was stirred at room temperature for 2 hours to obtain a liquid crystal aligning agent (A2).

<Synthesis Example 3 of polyamic acid>
NMP (93.3 g) and DA-1 (50.0 mmol, 13.4 g) were added to a 300 mL four-necked flask equipped with a stirrer and a nitrogen introduction tube, and stirred at room temperature until completely dissolved. (7.5 mmol, 1.7 g) was added, C-1 (40.0 mmol, 7.8 g) was added, and the mixture was stirred at room temperature for 6 hours to obtain a polyamic acid solution. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 296 mPa · s. 26 g of the obtained polyamic acid solution was collected, 28.6 g of NMP and 23.4 g of BCS were added and stirred at room temperature for 2 hours to obtain a liquid crystal aligning agent (A3).

<Synthesis Example 4 of polyamic acid>
NMP (91.4 g) and DA-1 (50.0 mmol, 13.4 g) were added to a 300 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and stirred at room temperature until completely dissolved. C-4 (7.5 mmol, 1.4 g) was added, and the mixture was stirred at 50 ° C. for 2 hours. After cooling to 23 ° C., C-1 (41.0 mmol, 7.9 g) was added, and at room temperature for 6 hours. The solution was stirred to obtain a polyamic acid solution. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 1296 mPa · s. 20 g of the resulting polyamic acid solution was collected, 50.0 g of NMP and 30.0 g of BCS were added, and the mixture was stirred at room temperature for 2 hours to obtain a liquid crystal aligning agent (A4).

<Synthesis Example 5 of polyamic acid>
NMP (169 g) and DA-1 (50.0 mmol, 13.4 g) were added to a 300 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and stirred at room temperature until completely dissolved. C-1 (41 0.0 mmol, 7.9 g) and C-5 (7.5 mmol, 1.6 g) were added and stirred at 50 ° C. for 15 hours to obtain a polyamic acid solution. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 341 mPa · s. 26 g of the obtained polyamic acid solution was collected, 28.6 g of NMP and 23.4 g of BCS were added and stirred at room temperature for 2 hours to obtain a liquid crystal aligning agent (A5).

<Synthesis Example 6 of polyamic acid>
NMP (179 g) and DA-1 (50.0 mmol, 13.4 g) were added to a 300 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and stirred at room temperature until completely dissolved. 0.0 mmol, 7.8 g) and C-6 (7.5 mmol, 3.1 g) were added and stirred at 50 ° C. for 15 hours to obtain a polyamic acid solution. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 295 mPa · s. 26 g of the obtained polyamic acid solution was collected, 28.6 g of NMP and 23.4 g of BCS were added, and the mixture was stirred at room temperature for 2 hours to obtain a liquid crystal aligning agent (A6).

<Comparative Example Synthesis 1 of Polyamic Acid>
NMP (162 g) and DA-2 (50.0 mmol, 12.7 g) were added to a 300 mL four-necked flask equipped with a stirrer and a nitrogen introduction tube, and stirred at room temperature until completely dissolved. 0.5 mmol, 9.3 g) was added and stirred at room temperature for 6 hours to obtain a polyamic acid solution. The viscosity of the polyamic acid solution at a temperature of 25 ° C. was 340 mPa · s. 26 g of the obtained polyamic acid solution was collected, 28.6 g of NMP and 23.4 g of BCS were added, and the mixture was stirred at room temperature for 2 hours to obtain a liquid crystal aligning agent (B1).

<Preparation of liquid crystal cell for liquid crystal alignment evaluation>
A liquid crystal cell having a configuration of an FFS liquid crystal display element was manufactured. First, a substrate with electrodes was prepared. The substrate is a glass substrate having a size of 30 mm × 35 mm and a thickness of 0.7 mm. On the substrate, an IZO electrode constituting the counter electrode as the first layer was formed on the entire surface. On the counter electrode of the first layer, a SiN (silicon nitride) film formed by the CVD method was formed as the second layer. The second layer SiN film has a thickness of 500 nm and functions as an interlayer insulating film. On the second SiN film, a comb-like pixel electrode formed by patterning an IZO film is arranged as a third layer, and two pixels, a first pixel and a second pixel, are formed. . The size of each pixel is 10 mm long and about 5 mm wide. At this time, the first-layer counter electrode and the third-layer pixel electrode are electrically insulated by the action of the second-layer SiN film.
The pixel electrode of the third layer is a comb-like tooth formed by arranging a plurality of electrode elements having a U-shape with a bent central portion, as in the drawing described in Japanese Patent Application Laid-Open No. 2014-77845 (Japan Published Patent Publication). It has a shape. The width in the short direction of each electrode element is 3 μm, and the distance between the electrode elements is 6 μm. Since the pixel electrode forming each pixel is configured by arranging a plurality of bent-shaped electrode elements having a bent central portion, the shape of each pixel is not rectangular but bent at the central portion in the same manner as the electrode elements. It has a shape that is similar to a bold, Kumon character. Each pixel is divided into upper and lower portions with a central bent portion as a boundary, and has a first region on the upper side of the bent portion and a second region on the lower side.
When the first region and the second region of each pixel are compared, the formation directions of the electrode elements of the pixel electrodes constituting them are different. That is, when the direction of a line segment projected onto the substrate with the polarization plane of polarized ultraviolet rays to be described later is used as a reference, in the first region of the pixel, the electrode element of the pixel electrode forms an angle of + 10 ° (clockwise). In the second region of the pixel, the electrode elements of the pixel electrode are formed so as to form an angle of −10 ° (clockwise). That is, in the first region and the second region of each pixel, the direction of the rotation operation (in-plane switching) of the liquid crystal induced by the voltage application between the pixel electrode and the counter electrode in the substrate plane is It comprised so that it might become a mutually reverse direction.

Next, after filtering the liquid crystal aligning agent obtained by the synthesis example and the comparative synthesis example with a 1.0 micrometer filter, it apply | coated to the prepared said board | substrate with an electrode by spin coat application | coating. Subsequently, it was dried for 90 seconds on a hot plate set to 70 ° C. Next, an exposure apparatus manufactured by Ushio Electric Co., Ltd .:
Using APL-050121S1S-APW01, the substrate was irradiated with linearly polarized ultraviolet light from a vertical direction through a wavelength selection filter and a polarizing plate. At this time, the direction of the polarization plane was set so that the direction of the line segment obtained by projecting the polarization plane of polarized ultraviolet rays onto the substrate was inclined by 10 ° with respect to the third-layer IZO comb-teeth electrode. Subsequently, baking was performed for 30 minutes in an IR (infrared) oven set at 230 ° C., and a substrate with a polyimide liquid crystal alignment film having a film thickness of 100 nm subjected to alignment treatment was obtained. Moreover, the board | substrate with a polyimide liquid crystal aligning film by which the alignment process was performed similarly to the above was also obtained for the glass substrate which has the columnar spacer of 4 micrometers in height with the ITO electrode formed in the back surface as a counter substrate. A set of these two substrates with a liquid crystal alignment film is used as one set, and a sealing agent is printed on the other substrate leaving a liquid crystal injection port. The polarizing planes were bonded and pressure-bonded so that the line segments projected onto the substrate were parallel. Thereafter, the sealing agent was cured to produce an empty cell having a cell gap of 4 μm. Liquid crystal MLC-7026-100 (Merck's negative liquid crystal) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an FFS liquid crystal cell. Thereafter, the obtained liquid crystal cell was heated at 120 ° C. for 60 minutes and allowed to stand at 23 ° C. overnight, and then used for evaluation of liquid crystal alignment.

<Evaluation of liquid crystal alignment (afterimage evaluation)>
The FFS liquid crystal cell prepared in Example 1 is installed between two polarizing plates arranged so that the polarization axes are orthogonal to each other, and the backlight is turned on with no voltage applied, and the brightness of the transmitted light. The arrangement angle of the liquid crystal cell was adjusted so as to be the smallest. Then, the rotation angle when the liquid crystal cell was rotated from the angle at which the second region of the pixel was darkest to the angle at which the first region was darkest was calculated as the initial orientation azimuth. Next, an alternating voltage of 16 V _PP was applied in a 70 ° C. oven at a frequency of 30 Hz for 168 hours. Thereafter, the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited and left as it was at room temperature for 1 hour. After standing, the orientation azimuth was measured in the same manner, and the difference in orientation azimuth before and after AC driving was calculated as an angle Δ (deg.).

<Preparation of liquid crystal cell for voltage holding ratio evaluation>
Using a glass substrate with an ITO electrode, and before printing the sealant, the same procedure as the above liquid crystal cell evaluation for liquid crystal alignment evaluation was performed, except that 4 μm bead spacers were scattered on the liquid crystal alignment film surface on one substrate. A liquid crystal cell for measuring voltage holding ratio was produced.

<Evaluation of voltage holding ratio>
Using this liquid crystal cell, the voltage holding ratio was evaluated. Specifically, an AC voltage of 2 VPP is applied to the liquid crystal cell obtained by the above method at a temperature of 70 ° C. for 60 μsec, the voltage after 167 msec is measured, and the voltage is maintained to determine how much voltage is maintained. Calculated as retention (also referred to as VHR). The measurement was performed using a voltage holding ratio measuring device (VHR-1, manufactured by Toyo Technica Co., Ltd.) with settings of Voltage: ± 1 V, Pulse Width: 60 μs, and Frame Period: 167 ms. When the value of the voltage holding ratio of the liquid crystal cell was 90% or more, it was defined as “good” and when the value of the voltage holding ratio was less than 90%, it was defined as “bad”.

Example 1
Using the liquid crystal aligning agent (A-1) obtained in Synthesis Example 1, two types of liquid crystal cells were produced as described above. Irradiation with polarized ultraviolet rays was performed using a high pressure mercury lamp through a wavelength selection filter: 240LCF and a 254 nm type polarizing plate. The irradiation amount of polarized ultraviolet rays is measured by measuring the amount of light using an illuminometer UVD-S254SB manufactured by Ushio Electric Co., Ltd., and changing the wavelength at 254 nm in the range of 200 to 1500 mJ / cm ^2. Four or more liquid crystal cells having different amounts were produced. For the evaluation results, the best results were selected from four or more liquid crystal display elements with different polarized UV irradiation doses, and the results of evaluating the liquid crystal orientation of these liquid crystal cells as the evaluation results of the liquid crystal display elements, The polarized UV irradiation dose with the best angle Δ was 1200 mJ / cm ² , and the angle Δ was 0.7 °, which was good.
Moreover, as a result of evaluating a voltage holding rate about the liquid crystal cell produced with the same polarized ultraviolet irradiation amount, the voltage holding rate was 91.2% and was favorable.

(Examples 2 and 3, Comparative Example 1)
The liquid crystal orientation and the voltage holding ratio were evaluated in the same manner as in Example 1 except that the liquid crystal aligning agents obtained in the synthesis examples and comparative synthesis examples were used, and the results are shown in Table 1.

As shown in Table 1, in Examples 1 to 3, the angle Δ (deg.), Which is the difference between the orientation azimuth angles before and after AC driving, is also very good at 0.7 and the VHR is also good. Therefore, since all have good afterimage characteristics, it is excellent in improving display products of liquid crystal display elements.
On the other hand, in Comparative Example 1, a characteristic in which the angle Δ (deg.) And the voltage holding ratio were highly compatible was not confirmed.
Thus, it was confirmed that the liquid crystal display device manufactured by the method of the present invention exhibits very excellent afterimage characteristics.

A lateral electric field drive type liquid crystal display element substrate manufactured using the polymer of the present invention or a horizontal electric field drive type liquid crystal display element having the substrate has excellent reliability, a large screen and a high definition liquid crystal television. It can utilize suitably for. In addition, since the liquid crystal alignment film manufactured by the method of the present invention has excellent liquid crystal alignment stability and reliability, it can be used for a variable phase shifter using liquid crystal. For example, it can be suitably used for an antenna that can vary the resonance frequency.

Claims (17)

The liquid crystal aligning agent containing the polymer obtained from the diamine which has a structure represented by following formula (1), and an organic solvent.

(In Formula (1), R ₁ is a monovalent organic group, R _{2 to} R ₅ are each independently a hydrogen atom or a monovalent organic group, provided that at least one of R ₂ and R ₃ is 1 R ₆ is a monovalent organic group, m is an integer of 0 to 2, and n is an integer of 0 to 4.)   A liquid crystal aligning agent comprising at least one polymer selected from the group consisting of a polyimide precursor that is a polymer of the diamine and tetracarboxylic dianhydride and a poimide that is an imidized product thereof, and an organic solvent. The liquid crystal aligning agent of Claim 1 or 2 with which the said diamine is represented by the following formula | equation (2).

(In formula (2), the definitions of R _{1 to} R ₆ , m and n are the same as in formula (1) above.) The liquid crystal aligning agent of any one of Claims 1-3 in which the said polyimide precursor is represented by following formula (6).

(In Formula (6), X ₁ is a tetravalent organic group derived from a tetracarboxylic acid derivative, Y ₁ is a divalent organic group derived from a diamine containing the structure of Formula (1), and R ₁₁ Is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.) The formula (6) is at least one structure of X ₁ is selected from the group consisting of the following structures, the liquid crystal aligning agent of claim 4.

The liquid crystal aligning agent of Claim 4 or 5 in which the polymer which has a structural unit represented by the said Formula (6) is contained 10 mol% or more with respect to all the polymers contained in a liquid crystal aligning agent. 7. The liquid crystal aligning agent according to claim 4, wherein the organic solvent contains at least one selected from the group consisting of 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether. . [I] A step of applying the composition according to any one of claims 1 to 7 on a substrate having a conductive film for driving a lateral electric field to form a coating film;
[II] a step of irradiating the coating film obtained in [I] with polarized ultraviolet rays; and [III] a step of heating the coating film obtained in [II];
The manufacturing method of the board | substrate which has the said liquid crystal aligning film which obtains the liquid crystal aligning film for horizontal electric field drive type liquid crystal display elements by which orientation control ability was provided by having.   The board | substrate which has the liquid crystal aligning film for horizontal electric field drive type liquid crystal display elements manufactured by the method of Claim 8.   A lateral electric field drive type liquid crystal display device comprising the substrate according to claim 9. Preparing a substrate (first substrate) according to claim 9;
[I ′] A step of applying the composition according to any one of claims 1 to 7 on a second substrate to form a coating film;
[II ′] a step of irradiating the coating film obtained in [I ′] with polarized ultraviolet rays; and [III ′] a step of heating the coating film obtained in [II ′];
Obtaining a liquid crystal alignment film imparted with alignment control capability by having a second substrate having the liquid crystal alignment film; and [IV] liquid crystal alignment of the first and second substrates via liquid crystal A step of obtaining a liquid crystal display element by arranging the first and second substrates so that the films face each other;
A method for producing a liquid crystal display element, comprising obtaining a lateral electric field drive type liquid crystal display element.   A lateral electric field drive type liquid crystal display device manufactured by the method according to claim 11. The at least 1 sort (s) of polymer chosen from the group which consists of the polyimide precursor which is a polymer of the diamine which has a structure represented by following formula (1), and tetracarboxylic dianhydride, and the imidized compound.

(In Formula (1), R ₁ is a monovalent organic group, R _{2 to} R ₅ are each independently a hydrogen atom or a monovalent organic group, provided that at least one of R ₂ and R ₃ is 1 R ₆ is a monovalent organic group, m is an integer of 0 to 2, and n is an integer of 0 to 4.) The polymer according to claim 13, wherein the diamine is represented by the following formula (2).

(In formula (2), the definitions of R _{1 to} R ₆ , m and n are the same as in formula (1) above.) The polymer according to claim 13 or 14, wherein the polyimide precursor is represented by the following formula (6).

(In Formula (6), X ₁ is a tetravalent organic group derived from a tetracarboxylic acid derivative, Y ₁ is a divalent organic group derived from a diamine containing the structure of Formula (1), and R ₁₁ Is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.) In the formula (6), the structure of X ₁ is at least one selected from the group consisting of the following structures, the polymer of claim 15.

Diamine represented by following formula (2).

(In Formula (1), R ₁ is a monovalent organic group, R _{2 to} R ₅ are each independently a hydrogen atom or a monovalent organic group, provided that at least one of R ₂ and R ₃ is 1 R ₆ is a monovalent organic group, m is an integer of 0 to 2, and n is an integer of 0 to 4.)