JP5282573B2 - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element using the same - Google Patents

Description

  The present invention relates to a liquid crystal alignment agent for producing a liquid crystal alignment film, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element having the liquid crystal alignment film.

  Liquid crystal display elements used in mobile phones, personal computer monitors, TVs, etc. have a structure in which liquid crystal molecules are sandwiched between liquid crystal alignment films. The display element utilizes the change of the orientation state depending on the voltage. Currently, the liquid crystal alignment film is mainly produced by applying and baking a solution of polyamic acid or polyimide. The liquid crystal alignment film plays a major role in the liquid crystal display element because it determines the alignment uniformity of the liquid crystal molecules and the pretilt angle with respect to the substrate and has a great influence on the electrical characteristics of the display element.

  Of these, the pretilt angle of the liquid crystal is one of the important parameters that influence the display characteristics, and is required to be controlled to an appropriate value according to the mode of the liquid crystal display element. For example, in a mode called IPS or FFS, the lower the pretilt angle, the wider the viewing angle and the better the color reproducibility. As a liquid crystal alignment film characterized in that a low pretilt angle can be obtained, one having an alkylene structure in a polyimide main chain is known (see Patent Documents 1 and 2).

  On the other hand, when paying attention to the side chain structure of the polymer, for example, if the hydrogen atom at the amide bond site of polyamic acid is replaced with a monovalent organic group, the pretilt angle of the liquid crystal is said to increase (see Patent Document 3).

  In addition, ion density is known as one of the parameters representing the electrical characteristics of a liquid crystal display element (see Patent Document 4). When the liquid crystal of the liquid crystal display element contains a large amount of ionic impurities, the value of ion density increases. When the value of the ion density is increased, the display quality of the liquid crystal display element is deteriorated, and there is a problem that display defects are likely to occur. Accordingly, development of a liquid crystal alignment film that reduces the ion density of the liquid crystal display element is required.

JP-A-10-123532 JP 2000-80164 A JP-A-2-250033 JP 2001-4971 A

  An object of the present invention is to provide a liquid crystal alignment film having a low pretilt angle and a low ion density, and a liquid crystal alignment agent for obtaining the liquid crystal alignment film.

As a result of intensive studies to achieve the above object, the present inventors have completed the present invention. That is, the gist of the present invention is as follows.
[1] A polymer obtained by reacting a diamine component containing an N-substituted diamine represented by the following formula (1) with tetracarboxylic dianhydride, and a polymer obtained by imidizing this polymer. A liquid crystal aligning agent, which is a solution containing at least one polymer selected from the group.

但し、式（１）中、Ｒ_１は２価の有機基であって、炭素数１〜５の２価の直鎖状炭化水素基、この炭化水素基の任意の水素原子がメチル基で置換されている有機基、又は下記式（２）で表される有機基であり；Ｒ_２及びＲ_３は水素原子又は炭素数が１〜４の炭化水素基であり、かつＲ_２及びＲ_３の少なくとも一方は炭素数が１〜４の炭化水素基である。）

However, substitution in the formula (1), R ₁ is a divalent organic group, a divalent linear hydrocarbon group having 1 to 5 carbon atoms, optional hydrogen atom of the hydrocarbon group is a methyl group Or an organic group represented by the following formula (2); R ₂ and R ₃ are a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, and R ₂ and R ₃ At least one is a hydrocarbon group having 1 to 4 carbon atoms. )

（式（２）中、Ａ_１〜Ａ_４は、それぞれ独立して、水素原子、メチル基、メトキシ基、イソプロピル基、カルボキシル基、Ｎ，Ｎ’−ジプロピルアミノ基、又はＮ，Ｎ’−ジアリルアミノ基であり、Ｙ_１〜Ｙ_４は、それぞれ独立して、単結合、メチレン基、カルボニル結合、エーテル結合、エステル結合、アミノ結合、又はアミド結合であり、
Ｒ_４は炭素数１〜５の２価の直鎖状炭化水素基、又はこの炭化水素基の任意の水素原子がメチル基で置換されている有機基であり、
ｍ_１〜ｍ_４はそれぞれ０又は１であり、
ｍ_１〜ｍ_４が全て０であるときは、
Ｘ_１はシクロヘキシル環、ベンゼン環、ナフタレン環、フルオレン環、カルバゾール環、ピリジン環、ピペリジン環、トラン骨格、又はスチルベン骨格であり、
ｍ_１〜ｍ_４のいずれか１つでも１であるときは、
Ｘ_１〜Ｘ_４は、それぞれ独立して、シクロヘキシル環、ベンゼン環、又はピペリジン環である。）
［２］式（１）におけるＲ_１が、式（２）で表される有機基であって、式（２）中のＡ₁が水素原子であり、Ｘ_１がベンゼン環であり、Ｒ_４が炭素数１〜５を有する２価の直鎖状炭化水素基であり、Ｙ_２が単結合であり、ｍ_２が１であり、ｍ_１、ｍ_３及びｍ_４が０である有機基である前記［１］に記載の液晶配向剤。
［３］式（１）におけるＲ_１が、下記式（３）、式（４）、式（５）、式（７）、又は式（８）の構造である、前記［１］に記載の液晶配向剤。

(In formula (2), A _{1 to} A ₄ are each independently a hydrogen atom, a methyl group, a methoxy group, an isopropyl group, a carboxyl group, an N, N′-dipropylamino group, or an N, N′— A diallylamino group, Y _{1 to} Y ₄ are each independently a single bond, a methylene group, a carbonyl bond, an ether bond, an ester bond, an amino bond, or an amide bond;
R ₄ is a divalent linear hydrocarbon group having 1 to 5 carbon atoms, or an organic group in which any hydrogen atom of this hydrocarbon group is substituted with a methyl group,
m _{1 to} m ₄ are each 0 or 1,
When m _{1 to} m ₄ are all 0,
X ₁ is a cyclohexyl ring, benzene ring, naphthalene ring, fluorene ring, carbazole ring, pyridine ring, piperidine ring, tolan skeleton, or stilbene skeleton,
When any one of m _{1 to} m ₄ is 1,
X _{1 to} X ₄ each independently represent a cyclohexyl ring, a benzene ring, or a piperidine ring. )
[2] R ₁ in Formula (1) is an organic group represented by Formula (2), A ₁ in Formula (2) is a hydrogen atom, X ₁ is a benzene ring, R ₄ Is a divalent linear hydrocarbon group having 1 to 5 carbon atoms, Y ₂ is a single bond, m ₂ is 1, and m ₁ , m ₃ and m ₄ are 0. The liquid crystal aligning agent as described in [1] above.
_{R 1} is in the [3] Equation (1), the following equation (3) is a structure of formula (4), Equation (5), equation (7), or Formula (8), according to [1] Liquid crystal aligning agent.

（式（３）中、ｎは１又は２である。）

(In Formula (3), n is 1 or 2.)

（式（４）中、Ａ_１は水素原子、メチル基、メトキシ基、イソプロピル基、カルボキシル基、Ｎ，Ｎ’−ジプロピルアミノ基、又はＮ，Ｎ’−ジアリルアミノ基である。）

(In the formula (4), _{A 1} is a hydrogen atom, a methyl group, a methoxy group, an isopropyl group, a carboxyl group, N, N'- di-propylamino group, or N, N'- diallylamino group.)

（式（５）中、Ｒ_５は単結合、エーテル結合、エステル結合、アミド結合、アミノ結合、カルボニル結合、エテニレン、エチニレン、又は下記式（６）で表される有機基であり、Ｒ_６及びＲ_７は水素原子又はメチル基である。）

(In the formula (5), R ₅ represents a single bond, an ether bond, an ester bond, an amide bond, amino bond, a carbonyl bond, ethenylene, an organic group represented by ethynylene, or the following formula (6), R ₆ and R ₇ is a hydrogen atom or a methyl group.)

（式（６）中、Ｙ_５及びＹ_６は、それぞれ独立して、単結合、エーテル結合、エステル結合、アミド結合、アミノ結合、又はカルボニル結合であり、Ｒ_８は炭素数１〜５の２価の直鎖状炭化水素基、又はこの炭化水素基の任意の水素原子がメチル基で置換されている有機基である。）

(In Formula (6), Y ₅ and Y ₆ are each independently a single bond, an ether bond, an ester bond, an amide bond, an amino bond, or a carbonyl bond, and R ₈ is a C 1-5 carbon atom. A valent linear hydrocarbon group or an organic group in which any hydrogen atom of this hydrocarbon group is substituted with a methyl group.)

（式（７）中、Ｙ_７及びＹ_８は単結合又はエーテル結合である）

(In Formula (7), Y ₇ and Y ₈ are a single bond or an ether bond)

（式（８）中、Ｙ_９及びＹ_１０は、それぞれ独立して、単結合又はエーテル結合であり、Ｒ_９は単結合、エーテル結合、又は下記式（９）で表される有機基である。）

(In Formula (8), Y ₉ and Y ₁₀ are each independently a single bond or an ether bond, and R ₉ is a single bond, an ether bond, or an organic group represented by the following formula (9). .)

（式（９）中、Ｙ_１１及びＹ_１２は単結合又はエーテル結合であり、Ｒ_１０は炭素数１〜５の２価の直鎖状炭化水素基、又はこの炭化水素基の任意の水素原子がメチル基で置換されている有機基である。）
［４］テトカラカルボン酸二無水物が、下記式(a)〜(g)から選ばれる構造である、前記［１］〜［３］のいずれかに記載の液晶配向剤。

(In formula (9), Y ₁₁ and Y ₁₂ are single bonds or ether bonds, and R ₁₀ is a divalent linear hydrocarbon group having 1 to 5 carbon atoms, or any hydrogen atom of this hydrocarbon group. Is an organic group substituted with a methyl group.)
[4] The liquid crystal aligning agent according to any one of [1] to [3], wherein the tetkaracarboxylic dianhydride has a structure selected from the following formulas (a) to (g).

［５］式（１）で表されるＮ−置換ジアミンが、ジアミン成分の５〜８０モル％である、前記［１］〜［４］のいずれかに記載の液晶配向剤。
［６］前記［１］〜［５］のいずれかに記載の液晶配向剤を用いて得られる液晶配向膜。
［７］前記［６］に記載の液晶配向膜を有する液晶表示素子。

[5] The liquid crystal aligning agent according to any one of [1] to [4], wherein the N-substituted diamine represented by the formula (1) is 5 to 80 mol% of the diamine component.
[6] A liquid crystal alignment film obtained using the liquid crystal aligning agent according to any one of [1] to [5].
[7] A liquid crystal display device having the liquid crystal alignment film according to [6].

  According to the liquid crystal aligning agent of the present invention, it is possible to obtain a liquid crystal aligning film in which the pretilt angle of the liquid crystal is low and stable and the ion density is small. Accordingly, a liquid crystal display element in a mode such as IPS or FFS using the liquid crystal alignment film of the present invention has a wide viewing angle, good color reproducibility, and is unlikely to cause display defects.

  The liquid crystal aligning agent of the present invention comprises a polymer obtained by reacting a diamine component containing an N-substituted diamine represented by the following formula (1) and tetracarboxylic dianhydride, and imidizing the polymer. The liquid crystal aligning agent is a solution containing at least one polymer selected from the group consisting of polymers.

（式（１）中、Ｒ_１、Ｒ_２及びＲ_３の定義は前記したとおりである。）
上記のＮ−置換ジアミンを含有するジアミン成分とテトラカルボン酸二無水物とを反応させて得られる重合体は、炭素数が１〜４の炭化水素基でＮ−置換されたアミック酸の構造を有している。このＮ−置換されたアミック酸のアミド部位はイミド化が起こりにくくなる。また、Ｎ−置換されていることで、分子間水素結合が抑制される。即ち、イミド化の抑制及び重合体鎖間の水素結合の抑制という２つの作用により、重合体鎖の配向自由度が確保される。更に、アミック酸のアミド部位がN−置換されることで、窒素原子に結合している水素原子が炭素原子に置き換わる。これらのことにより、本発明の液晶配向剤から得られた液晶配向膜は、液晶のプレチルト角を低く抑えることができ、かつイオン密度を小さくすることができる。

(In formula (1), the definitions of R ₁ , R ₂ and R ₃ are as described above.)
The polymer obtained by reacting the diamine component containing the N-substituted diamine with tetracarboxylic dianhydride has a structure of an amic acid that is N-substituted with a hydrocarbon group having 1 to 4 carbon atoms. Have. The amide site of this N-substituted amic acid is less likely to imidize. Moreover, intermolecular hydrogen bonding is suppressed by being N-substituted. That is, the degree of freedom of orientation of the polymer chain is ensured by two actions of suppression of imidization and suppression of hydrogen bond between the polymer chains. Furthermore, the amide moiety of the amic acid is N-substituted, whereby the hydrogen atom bonded to the nitrogen atom is replaced with a carbon atom. By these things, the liquid crystal aligning film obtained from the liquid crystal aligning agent of this invention can suppress the pretilt angle of a liquid crystal low, and can make an ion density small.

  In the present invention, the above-described liquid crystal alignment film containing a polymer using a diamine component containing an N-substituted diamine represented by the above formula (1) and / or a polymer polyimide obtained by imidizing this polymer is loaded. Although it is not necessarily clear whether it has such an excellent effect, it is considered as follows. That is, the liquid crystal alignment film is produced by applying a polyimide precursor such as polyamic acid or a polyimide solution to a substrate, baking it, and performing an alignment treatment such as rubbing. Polyamic acid has an advantage that it can be easily obtained by reacting diamine with tetracarboxylic dianhydride. This polyamic acid can be dehydrated and closed by heating to obtain a polyimide. In general, when the heating temperature of the polyamic acid film having the same structure is changed to produce polyimide films having different imidization rates, and this is rubbed into a liquid crystal alignment film, the higher the imidization rate, the higher the pretilt of the liquid crystal. The corner increases and the ion density decreases. Since the change from polyamic acid to polyimide makes the polymer main chain rigid, the degree of freedom of orientation of the polymer chain is constrained, and the polymer chain becomes difficult to be stretched when rubbing. In the chemical structure, a hydrogen atom bonded to a nitrogen atom is replaced with a carbon atom due to a change from an amide to an imide.

A polymer using a diamine component containing an N-substituted diamine represented by the above formula (1) and / or a polymer polyimide obtained by imidizing this polymer is a degree of freedom of alignment of a polymer used for a liquid crystal alignment film. The pretilt angle of the liquid crystal can be lowered by increasing the stretchability with respect to the rubbing treatment, and the ion density can be reduced by replacing the hydrogen atom bonded to the nitrogen atom of the amide site with a carbon atom. It seems to be.
In the present invention, in the structure of the formula (1), if the N-substituent of R ₂ or R ₃ is sterically bulky, on the contrary, the degree of freedom of orientation of the polymer chain is hindered. 1-4 hydrocarbon groups are suitable, a methyl group or an ethyl group is preferred, and a methyl group is particularly preferred.

R ₁ in the structure of the formula (1) is a divalent organic group, and a divalent linear hydrocarbon group having 1 to 5 carbon atoms, and any hydrogen atom of this hydrocarbon group is a methyl group Or a group represented by the following formula (2). The divalent organic group represented by R ₁ is a linear hydrocarbon group having 6 or more carbon atoms, a perfluoro group, a monovalent organic group having an aromatic substituent, or a monovalent organic group having an aliphatic cyclic substituent. Those having no group capable of increasing the pretilt angle of the liquid crystal when a liquid crystal alignment film is formed, such as a steroid group, are preferable.

In the above formula (2), A _{1 to} A ₄ are each independently a hydrogen atom, methyl group, methoxy group, isopropyl group, carboxyl group, N, N′-dipropylamino group, or N, N′—. A diallylamino group, preferably a hydrogen atom, a methyl group, a methoxy group, or a carboxyl group. Y _{1 to} Y ₄ are each independently a single bond, a methylene group, a carbonyl bond, an ether bond, an ester bond, an amino bond, or an amide bond, preferably a single bond, a methylene group, an ether bond, or an amino bond. It is. R ₄ is a divalent linear hydrocarbon group having 1 to 5 carbon atoms, or an organic group in which any hydrogen atom of this hydrocarbon group is substituted with a methyl group, preferably 1 to 5 carbon atoms. It is a divalent linear hydrocarbon group. m _{1 to} m ₄ are each 0 or 1, and when m _{1 to} m ₄ are all 0, X ₁ is a cyclohexyl ring, a benzene ring, a naphthalene ring, a fluorene ring, a carbazole ring, a pyridine ring, a piperidine ring, a tolan skeleton or a stilbene _skeleton, when it is either even one 1 _{m 1 ~m 4, X 1 ~X} 4 is a cyclohexyl ring, benzene ring, or a piperidine ring. In a preferable combination of m _{1 to} m ₄ , m ₁ is 0, and m _{2 to} m ₄ are each independently 0 or 1. More preferably, m ₁ and m ₃ are 0, and m ₂ and m ₄ are each independently 0 or 1, or m ₁ and m ₂ are 0 and m ₃ and m ₄ are each independently 0 or 1. is there. Preferred X _{1 to} X ₄ are a benzene ring or a naphthalene ring, and more preferably a benzene ring.

  Specific examples of the divalent linear hydrocarbon group having 1 to 5 carbon atoms and the organic group in which any hydrogen atom of the hydrocarbon group is substituted with a methyl group include a methylene group, an ethylene group, Examples include trimethylene group, ethylidene group, isopropylidene group, propylene group, 2,2′-dimethyltrimethylene group, tetramethylene group, pentamethylene group and the like.

R ₁ in Formula (1) is an organic group represented by Formula (2), A ₁ in Formula (2) is a hydrogen atom, X ₁ is a benzene ring, and R ₄ is It is a divalent linear hydrocarbon group having 1 to 5 carbon atoms, Y ₂ is a single bond, m ₂ is 1, and m ₁ , m ₃ and m ₄ are 0. Is preferred.
More preferable examples of R ₁ include structures of the following formula (3), formula (4), formula (5), formula (7), or formula (8).

（式（３）中、ｎは１又は２である。）

(In Formula (3), n is 1 or 2.)

（式（４）中、Ａ_１は水素原子、メチル基、メトキシ基、イソプロピル基、カルボキシル基、Ｎ，Ｎ’−ジプロピルアミノ基、又はＮ，Ｎ’−ジアリルアミノ基である。）

(In the formula (4), _{A 1} is a hydrogen atom, a methyl group, a methoxy group, an isopropyl group, a carboxyl group, N, N'- di-propylamino group, or N, N'- diallylamino group.)

（式（５）中、Ｒ_５は単結合、エーテル結合、エステル結合、アミド結合、アミノ結合、カルボニル結合、エテニレン、エチニレン、又は下記式（６）で表される基であり、Ｒ_６及びＲ_７は水素原子又はメチル基である。）

(In the formula (5), R ₅ is a single bond, an ether bond, an ester bond, an amide bond, an amino bond, a carbonyl bond, ethenylene, ethynylene, or a group represented by the following formula (6), and R ₆ and R ₇ is a hydrogen atom or a methyl group.)

（式（６）中、Ｙ_５及びＹ_６は、それぞれ独立して、単結合、エーテル結合、エステル結合、アミド結合、アミノ結合、又はカルボニル結合であり、Ｒ_８は炭素数１〜５の２価の直鎖状炭化水素基、又はこの炭化水素基の任意の水素原子がメチル基で置換されている有機基である。）

(In Formula (6), Y ₅ and Y ₆ are each independently a single bond, an ether bond, an ester bond, an amide bond, an amino bond, or a carbonyl bond, and R ₈ is a C 1-5 carbon atom. A valent linear hydrocarbon group or an organic group in which any hydrogen atom of this hydrocarbon group is substituted with a methyl group.)

（式（７）中、Ｙ_７及びＹ_８は単結合又はエーテル結合である）

(In Formula (7), Y ₇ and Y ₈ are a single bond or an ether bond)

（式（８）中、Ｙ_９及びＹ_１０は単結合又はエーテル結合であり、Ｒ_９は単結合、エーテル結合、又は下記式（９）で表される有機基である。）

(In Formula (8), Y ₉ and Y ₁₀ are a single bond or an ether bond, and R ₉ is a single bond, an ether bond, or an organic group represented by the following Formula (9).)

（式（９）中、Ｙ_１１及びＹ_１２は単結合又はエーテル結合であり、Ｒ_１０は炭素数１〜５の２価の直鎖状炭化水素基、又はこの炭化水素基の任意の水素原子がメチル基で置換されている有機基である。）
上記式（６）のＲ_８又は式（９）のＲ_１０において、炭素数１〜５の２価の直鎖状炭化水素基、又はこの炭化水素基の任意の水素原子がメチル基で置換されている有機基の具体例としては、メチレン基、エチレン基、トリメチレン基、エチリデン基、イソプロピリデン基、プロピレン基、２，２’−ジメチルトリメチレン基、テトラメチレン基、ペンタメチレン基等を挙げることができる。

(In formula (9), Y ₁₁ and Y ₁₂ are single bonds or ether bonds, and R ₁₀ is a divalent linear hydrocarbon group having 1 to 5 carbon atoms, or any hydrogen atom of this hydrocarbon group. Is an organic group substituted with a methyl group.)
In R ₈ of the above formula (6) or R ₁₀ of the formula (9), a divalent linear hydrocarbon group having 1 to 5 carbon atoms or an arbitrary hydrogen atom of this hydrocarbon group is substituted with a methyl group. Specific examples of the organic group include a methylene group, an ethylene group, a trimethylene group, an ethylidene group, an isopropylidene group, a propylene group, a 2,2′-dimethyltrimethylene group, a tetramethylene group, and a pentamethylene group. Can do.

Above, it is shown in the table below a specific example of R ₁ is not limited thereto.

上記の構造の中でも、No.7、No.8、No.16、No.17、No.18、No.20、No.22、No.28、No.29、No.30、No.31、No.35、No.36、No.37、No.40、No.42、No.52、No.53、No.56、No.57、No.58、No.59、No.61、No.62、No.63等は特に好ましい。

Among the above structures, No. 7, No. 8, No. 16, No. 17, No. 18, No. 20, No. 22, No. 28, No. 29, No. 30, No. 31, No.35, No.36, No.37, No.40, No.42, No.52, No.53, No.56, No.57, No.58, No.59, No.61, No. 62, No. 63 and the like are particularly preferable.

  The polymer used for the liquid crystal aligning agent of the present invention is a polymer obtained by reacting a diamine component containing the N-substituted diamine represented by the above formula (1) with tetracarboxylic dianhydride, and this polymer. It is at least one kind of polymer selected from the group consisting of polymers obtained by imidizing polymers. This diamine component may consist only of the N-substituted diamine represented by the formula (1), and at least one of the N-substituted diamines represented by the formula (1) and other diamines. One or a combination of two or more selected from may be used.

  When a diamine other than the N-substituted diamine represented by the formula (1) is combined as the diamine component, the diamine component preferably contains 5 to 80 mol% of the diamine represented by the formula (1), more preferably. Is from 10 to 60 mol%, more preferably from 15 to 40 mol%. If it is such a range, when it is set as a liquid crystal aligning film, while being able to obtain a low pretilt angle, the characteristic given by the diamine used in combination can also be obtained.

  In addition, the diamine used in combination is a liquid crystal alignment film such as a long-chain alkyl group, a perfluoro group, an organic group having an aromatic substituent, an organic group having an aliphatic cyclic substituent, or a steroid skeleton group. Those having no side chain bonded to increase the pretilt angle are preferred. Examples of such diamines are given below, but are not limited thereto.

  Examples of alicyclic diamines include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4′-diaminodicyclohexylmethane, 4,4′-diamino-3,3′-dimethyldicyclohexylamine, isophorone diamine, etc. Is mentioned.

  Examples of aromatic diamines include o-, m-, p-phenylenediamine, diaminotoluenes (eg 2,4-diaminotoluene), 1,4-diamino-2-methoxybenzene, 2,5-diamino- p-xylene, 1,3-diamino-4-chlorobenzene, 3,5-diaminobenzoic acid, 1,4-diamino-2,5-dichlorobenzene, 4,4′-diamino-1,2-diphenylethane, 4 , 4′-diamino-2,2′-dimethylbibenzyl, 4,4′-diaminodiphenylmethane, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diamino-3,3 ′ -Dimethyldiphenylmethane, 2,2'-diaminostilbene, 4,4'-diaminostilbene, 4,4'-diaminodiphenyl ether, 3,4'- Diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfone, 3,3′-diaminodiphenyl sulfone, 4,4′-diaminobenzophenone, 1,3-bis (3-aminophenoxy) benzene 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 3,5-bis (4-aminophenoxy) benzoic acid, 4,4′-bis (4- Aminophenoxy) bibenzyl, 2,2-bis [(4-aminophenoxy) methyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, bis [4- (3-aminophenoxy) phenyl ] Sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, 1,1-bis (4-aminophenyl) cycl Hexane, α, α′-bis (4-aminophenyl) -1,4-diisopropylbenzene, 9,9-bis (4-aminophenyl) fluorene, 4,4′-diaminodiphenylamine, 2,4-diaminodiphenylamine, 1,8-diaminonaphthalene, 1,5-diaminonaphthalene, 1,5-diaminoanthraquinone, 1,3-diaminopyrene, 1,6-diaminopyrene, 1,8-diaminopyrene, 2,7-diaminofluorene, 1 , 3-bis (4-aminophenyl) tetramethyldisiloxane, benzidine, 2,2'-dimethylbenzidine, 1,2-bis (4-aminophenyl) ethane, 1,3-bis (4-aminophenyl) propane 1,4-bis (4-aminophenyl) butane, 1,5-bis (4-aminophenyl) pentane, 1,6- (4-aminophenyl) hexane, 1,7-bis (4-aminophenyl) heptane, 1,8-bis (4-aminophenyl) octane, 1,9-bis (4-aminophenyl) nonane, 1, 10-bis (4-aminophenyl) decane, 1,3-bis (4-aminophenoxy) propane, 1,4-bis (4-aminophenoxy) butane, 1,5-bis (4-aminophenoxy) pentane, 1,6-bis (4-aminophenoxy) hexane, 1,7-bis (4-aminophenoxy) heptane, 1,8-bis (4-aminophenoxy) octane, 1,9-bis (4-aminophenoxy) Nonane, 1,10-bis (4-aminophenoxy) decane, di (4-aminophenyl) propane-1,3-dioate, di (4-aminophenyl) butane-1,4- Diate, di (4-aminophenyl) pentane-1,5-dioate, di (4-aminophenyl) hexane-1,6-dioate, di (4-aminophenyl) heptane-1,7-dioate, di (4 -Aminophenyl) octane-1,8-dioate, di (4-aminophenyl) nonane-1,9-dioate, di (4-aminophenyl) decane-1,10-dioate, 1,3-bis [4- (4-aminophenoxy) phenoxy] propane, 1,4-bis [4- (4-aminophenoxy) phenoxy] butane, 1,5-bis [4- (4-aminophenoxy) phenoxy] pentane, 1,6- Bis [4- (4-aminophenoxy) phenoxy] hexane, 1,7-bis [4- (4-aminophenoxy) phenoxy] heptane, 1,8-bis [ -(4-aminophenoxy) phenoxy] octane, 1,9-bis [4- (4-aminophenoxy) phenoxy] nonane, 1,10-bis [4- (4-aminophenoxy) phenoxy] decane and the like. .

  Examples of heterocyclic diamines include 2,6-diaminopyridine, 2,4-diaminopyridine, 2,4-diamino-1,3,5-triazine, 2,7-diaminodibenzofuran, 3,6-diaminocarbazole 2,4-diamino-6-isopropyl-1,3,5-triazine, 2,5-bis (4-aminophenyl) -1,3,4-oxadiazole and the like.

  Examples of aliphatic diamines include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1 , 8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,3-diamino-2,2-dimethylpropane, 1,6-diamino-2,5-dimethylhexane, 1,7-diamino -2,5-dimethylheptane, 1,7-diamino-4,4-dimethylheptane, 1,7-diamino-3-methylheptane, 1,9-diamino-5-methylheptane, 1,12-diaminododecane, Examples include 1,18-diaminooctadecane and 1,2-bis (3-aminopropoxy) ethane.

  The tetracarboxylic dianhydride to be reacted with the diamine component containing the N-substituted diamine represented by the formula (1) is a long chain alkyl group, a perfluoro group, an organic group having an aromatic substituent, an aliphatic group. An organic group having a cyclic substituent, a steroid skeleton group, or the like, which does not have a side chain bonded to increase the pretilt angle of the liquid crystal when the liquid crystal alignment film is formed, is preferable. Examples of such tetracarboxylic dianhydrides are shown below, but are not limited thereto.

As tetracarboxylic dianhydrides having an alicyclic structure or an aliphatic structure, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetra Carboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic Acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride , 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 4- (2,5-dioxotetrahydro-3-furanyl) -cyclohexane-1,2-dicarboxylic anhydride 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, bicyclo [2,2,2] oct-7-ene-2,3 , 5,6-tetracarboxylic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, 3,4-dicarboxy-1,2,3 , 4-Tetrahydro-6-methyl-1-naphthalene succinic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, bicyclo [3,3,0] octane-2,4,6 8-tetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5,6-tetocarboxoxynorbornane dianhydride, 3,5,6- Tricarboxynorbornane-2-acetic acid dianhydride , Tricyclo [4.2.1.0 ^{2, 5]} nonane 3,4,7,8-tetracarboxylic acid dianhydride, tetracyclo [4.4.1.0 ^2,5 .0 ^7,10] undecane -3,4,8,9-tetracarboxylic dianhydride, hexacyclo [6.6.0.1 ^2,7 . 0 ^3,6 . 1 ^9,14 . 0 ^10,13] hexadecane -4,5,11,12- tetracarboxylic dianhydride, 1,4-bis (2,5-di-oxo-3-furanyl) hexane, 1,4-bis (2, 6-dioxotetrahydro-4-pyranyl) hexane and the like.

  As aromatic tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride Anhydride, 2,3,3 ′, 4-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 2,3,3 ′, 4-benzophenonetetracarboxylic Acid dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2, , 6,7-anthracenetetracarboxylic dianhydride, 4- (2,5-dioxotetrahydro-3-furanyl) phthalic anhydride, 2,5-dicarboxymethylterephthalic dianhydride, 4,6- And dicarboxymethylisophthalic dianhydride.

  In addition, 1,4-bis (2,5-dioxotetrahydro-3-furanyl) benzene, 1,4-bis (2,6-dioxotetrahydro-4-pyranyl) benzene, 1,4-bis (2 , 5-dioxotetrahydro-3-methyl-3-furanyl) benzene, 1,4-bis (2,6-dioxotetrahydro-4-methyl-4-pyranyl) benzene and the like.

  Two or more of the above tetracarboxylic dianhydrides may be mixed and used. When the tetracarboxylic dianhydride component is preferably a tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure, preferably 5 to 50 mol%, more preferably 15 to 50 mol%, the voltage holding of the liquid crystal display device This is preferable because the rate is improved. Among tetracarboxylic dianhydrides having an alicyclic structure or an aliphatic structure, 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 2,3,5-tricarboxycyclopentylacetic acid dianhydride are particularly preferable. , Bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene -1,2-dicarboxylic anhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, and the like. Further, when 20 to 90 mol%, more preferably 50 to 90 mol% of the tetracarboxylic dianhydride component is an aromatic tetracarboxylic dianhydride, the liquid crystal orientation is improved and the liquid crystal display element is accumulated. This is preferable because the charge is reduced. Particularly preferred among aromatic tetracarboxylic dianhydrides are pyromellitic dianhydride and 2,3,6,7-naphthalenetetracarboxylic dianhydride.

  The polymerization reaction of the diamine component containing the N-substituted diamine represented by the formula (1) and the tetracarboxylic dianhydride is performed by mixing the raw materials to be used in an organic solvent in the same manner as a normal polyamic acid. It can be carried out. Specifically, a solution in which a diamine component is dispersed or dissolved in an organic solvent is stirred, and tetracarboxylic dianhydride is added as it is or dispersed or dissolved in an organic solvent. Conversely, tetracarboxylic dianhydride is added. Examples thereof include a method of adding a diamine component to a solution in which the product is dispersed or dissolved in an organic solvent, and a method of alternately adding a tetracarboxylic dianhydride component and a diamine component. In addition, when at least one of the tetracarboxylic dianhydride component and the diamine component is composed of a plurality of types of compounds, the plurality of types of components may be preliminarily mixed and may be polymerized separately or sequentially. May be.

  The temperature during the polymerization reaction is usually 0 to 150 ° C, preferably 5 to 100 ° C, more preferably 10 to 80 ° C. When the temperature is higher, the polymerization reaction is completed earlier, but when it is too high, a high molecular weight polymer may not be obtained. The polymerization reaction can be carried out at any concentration, but if the concentration is too low, it will be difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution will become too high and uniform stirring will occur. Since it becomes difficult, Preferably it is 1-50 mass%, More preferably, it is 5-30 mass%. The initial stage of the polymerization reaction may be performed at a high concentration, and then an organic solvent may be added.

  The organic solvent used in the above reaction is not particularly limited as long as the produced polymer is soluble. Specific examples include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, dimethyl sulfone, hexamethyl sulfoxide, γ-butyrolactone, and the like. Can be mentioned. These may be used alone or in combination. Furthermore, even if it is a solvent that does not dissolve the polymer alone, it may be used by mixing with the above solvent as long as the produced polymer does not precipitate. Moreover, since water in the organic solvent inhibits the polymerization reaction and further causes hydrolysis of the produced polymer, it is preferable to use a dehydrated and dried organic solvent as much as possible.

The ratio of the diamine component and tetracarboxylic dianhydride used in the polymerization reaction is preferably 1: 0.8 to 1: 1.2 in molar ratio. The closer the molar ratio is to 1: 1, the greater the molecular weight of the polymer obtained. The molecular weight of the polymer affects the viscosity of the liquid crystal aligning agent and the physical strength of the liquid crystal aligning film. If the molecular weight of the polymer is too large, the coating workability and coating film uniformity of the liquid crystal aligning agent will deteriorate. If the molecular weight is too small, the strength of the coating film obtained from the liquid crystal aligning agent may be insufficient. Accordingly, the molecular weight of the polymer used in the liquid crystal aligning agent of the present invention is preferably 2,000 to 500,000, more preferably 5,000 to 300,000, and still more preferably 10,000 in terms of weight average molecular weight. ~ 100,000.
The polymer obtained as described above can use the reaction solution as the liquid crystal aligning agent of the present invention, but will be described later when the solvent used for the polymerization is not desired to be contained in the liquid crystal aligning agent. The polymer may be recovered by means and redissolved with an organic solvent to obtain a liquid crystal aligning agent.

  Moreover, when the polymer obtained above contains the unsubstituted amic acid group, you may use the polymer which imidated this for a liquid crystal aligning agent. The imidization reaction for dehydrating and ring-closing the amic acid group is simple by chemical imidization in which a catalyst is added to the polymer solution obtained by the reaction between the diamine component and tetracarboxylic dianhydride. The imidization is preferable because the imidization reaction proceeds at a relatively low temperature and the molecular weight of the polymer is hardly lowered during the imidization process.

  Chemical imidation can be performed by stirring a polymer to be imidized in an organic solvent in the presence of a basic catalyst and an acid anhydride. As an organic solvent, the solvent used at the time of the polymerization reaction mentioned above can be used. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Of these, pyridine is preferable because it has an appropriate basicity for proceeding with the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride and the like. Among them, use of acetic anhydride is preferable because purification after completion of the reaction is facilitated.

  The temperature for carrying out the imidization reaction is -20 to 200 ° C, preferably 0 to 180 ° C, and the reaction time can be 1 to 100 hours. The amount of the basic catalyst is 0.5 to 30 mol times, preferably 2 to 20 mol times of the amic acid group, and the amount of the acid anhydride is 1 to 50 mol times, preferably 3 to 30 mol of the amic acid group. Is double. The imidation ratio of the resulting polymer can be controlled by adjusting the amount of catalyst, temperature, and reaction time. Since the added catalyst or the like remains in the solution after the imidation reaction, the obtained imidized polymer is recovered by the means described below, redissolved in an organic solvent, and the liquid crystal alignment according to the present invention. It is preferable to use an agent.

  To recover the polymer from the reaction solution, whether it is an imidized polymer or a non-imidated polymer, the reaction solution is poured into a stirring poor solvent and precipitated. The polymer may be filtered off. Although it does not specifically limit as a poor solvent used for collection | recovery of a polymer, Methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene etc. can be illustrated. The recovered polymer is preferably washed with the above poor solvent and then dried. The recovered polymer can be redissolved with an organic solvent to obtain the liquid crystal aligning agent of the present invention.

  The organic solvent used for redissolving the polymer, that is, the solvent used for the liquid crystal aligning agent of the present invention is not particularly limited as long as it dissolves the polymer contained in the liquid crystal aligning agent. Specific examples are N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone. Dimethyl sulfoxide, dimethyl sulfone, hexamethyl sulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolidinone and the like. Among them, N-methyl-2-pyrrolidone and γ-butyrolactone are preferable as the solvent for dissolving the polymer contained in the liquid crystal aligning agent. You may use these 1 type or in mixture of 2 or more types. Even if the solvent alone does not dissolve the polymer, it may be mixed as long as the polymer does not precipitate.

  Furthermore, you may add the solvent for improving the coating-film uniformity at the time of apply | coating a liquid crystal aligning agent to a board | substrate. Such solvents include ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2- Propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, di Propylene glycol monomethyl ether, 2- (2-ethoxypropoxy) propanol, lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester Ether, and the like lactic isoamyl ester. Among them, butyl cellosolve and dipropylene glycol monomethyl ether are preferable as the solvent for improving the coating film uniformity. Two types of these solvents may be used in combination.

  The liquid crystal aligning agent of the present invention preferably contains a solvent for dissolving the polymer contained in the liquid crystal aligning agent and a solvent for improving the uniformity of the coating film, specifically, N-methyl-2-pyrrolidone. And a mixed solvent composed of butyl cellosolve or a mixed solvent composed of γ-butyrolactone and dipropylene glycol monomethyl ether.

  In addition, an additive such as a silane coupling agent may be added to the liquid crystal aligning agent of the present invention in order to improve the adhesion of the coating film to the substrate. The silane coupling agent is preferably 3-aminopropyltriethoxysilane or 3-diapropylpropylethoxymethylsilane, and the additive is 0.1 to 10 parts by mass with respect to 100 parts by mass of the polymer. Is preferred. Moreover, the polymer contained in the liquid crystal aligning agent of this invention may be 2 or more types.

  The density | concentration of the polymer in the liquid crystal aligning agent of this invention can be suitably changed with the setting of the thickness of the liquid crystal aligning film to form. Usually, the content (concentration) of the polymer is preferably 1 to 10% by mass, particularly preferably 2 to 7% by mass in view of the thickness of the liquid crystal alignment film to be used.

  The liquid crystal aligning agent of the present invention obtained as described above is filtered, applied to a substrate, dried and baked to form a coating film, and this coating film surface is subjected to alignment treatment such as rubbing and light irradiation. Therefore, it can be used as a liquid crystal alignment film.

  When this liquid crystal alignment film is used for a liquid crystal display element, the substrate on which the liquid crystal aligning agent is applied is not particularly limited as long as it is a highly transparent substrate, and a glass substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate, or the like is used. In view of the simplification of the process, it is preferable to use a substrate on which an ITO electrode or the like for driving the liquid crystal is formed. Further, in the reflection type liquid crystal display element, an opaque material such as a silicon wafer can be used as long as the substrate is only on one side, and in this case, a material that reflects light such as aluminum can be used.

Examples of the method for applying the liquid crystal aligning agent include a spin coating method, a printing method, an ink jet method, and the like, but from the viewpoint of productivity, the transfer printing method is widely used industrially, and in the liquid crystal aligning agent of the present invention. Are also preferably used.
The drying process after applying the liquid crystal aligning agent is not necessarily required, but if the time from application to baking is not constant for each substrate, or if baking is not performed immediately after application, a drying process is included. Is preferred. The drying is not particularly limited as long as the solvent is evaporated to such an extent that the shape of the coating film is not deformed by transporting the substrate or the like. If a specific example is given, the method of drying on the hotplate of temperature 50-150 degreeC, Preferably temperature 80-120 degreeC for 0.5 to 30 minutes, Preferably it is 1 to 5 minutes is taken.

The substrate coated with the liquid crystal aligning agent can be baked at an arbitrary temperature of 100 to 350 ° C., preferably 150 to 300 ° C., more preferably 180 to 250 ° C.
If the thickness of the coating film after baking is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may be lowered, so it is preferably 5 to 300 nm, more preferably 10-100 nm.

The liquid crystal display element of the present invention is a liquid crystal display element obtained by obtaining a substrate with a liquid crystal alignment film from the liquid crystal aligning agent of the present invention by the method described above, and then preparing a liquid crystal cell by a known method.
The manufacturing method of the liquid crystal cell is not particularly limited. For example, a pair of substrates on which a liquid crystal alignment film is formed are placed with a liquid crystal alignment film surface inside and a spacer interposed therebetween, and then the surroundings are sealed. A method of sealing by injecting liquid crystal under reduced pressure, a method of installing a spacer on one substrate, surrounding the periphery of the substrate with a sealing agent, dropping the liquid crystal in this enclosure, and then bonding the substrates together Etc. In that case, the spacer to be used is preferably 1 to 30 μm, more preferably 2 to 10 μm.

Thus, since the liquid crystal display element produced using the liquid crystal aligning agent of the present invention has a low and stable liquid crystal pretilt angle, the liquid crystal display element is suitably used for a liquid crystal display element of a mode such as IPS or FFS. .
The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples.

The abbreviations and structures of the compounds used in the examples and comparative examples are shown below.
CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride PMDA: pyromellitic dianhydride Me-4APhA: 4- (2- (methylamino) ethyl) aniline Me-DDM: N-methyl-4 , 4′-Diaminodiphenylmethane 4APhA: 4- (2-aminoethyl) aniline DDM: 4,4′-diaminodiphenylmethane DA-5MG: 1,5-bis (4-aminophenoxy) pentane

以下に、粘度、分子量、プレチルト角、電圧保持率、イオン密度の各測定方法を示す。

The measurement methods for viscosity, molecular weight, pretilt angle, voltage holding ratio, and ion density are shown below.

[viscosity]
In the synthesis example, the viscosity of the polyamic acid solution is an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.). Measured with
[Molecular weight]
The molecular weight of the polyamic acid is measured by a GPC (room temperature gel permeation chromatography) apparatus, and is a number average molecular weight (hereinafter also referred to as Mn) and a weight average molecular weight (hereinafter also referred to as Mw) in terms of polyethylene glycol and polyethylene oxide. ) Was calculated.
GPC device: manufactured by Shodex (GPC-101)
Column: manufactured by Shodex (series of KD803 and KD805)
Column temperature: 50 ° C
Eluent: N, N-dimethylformamide (as additives, lithium bromide-hydrate (LiBr · H ₂ O) 30 mmol / L, phosphoric acid / anhydrous crystal (o-phosphoric acid) 30 mmol / L, tetrahydrofuran) (THF) is 10 ml / L)
Flow rate: 1.0 ml / standard curve preparation standard sample: Tosoh TSK standard polyethylene oxide (weight average molecular weight (Mw) about 900,000, 150,000, 100,000, 30,000) and Polymer Laboratories polyethylene glycol (peak top molecular weight) (Mp) about 12,000, 4,000, 1,000).

[Pretilt angle]
In Examples and Comparative Examples, the pretilt angle of the liquid crystal was measured using a measuring apparatus TBA107 (manufactured by autronic-MELCHERS GmbH) based on a crystal rotation method.
[Voltage holding ratio]
The voltage holding ratio of the liquid crystal cell was measured as follows.
By applying a voltage of 4 V for 60 μs and measuring the voltage after 16.67 ms, the fluctuation from the initial value was calculated as the voltage holding ratio. At the time of measurement, the temperature of the liquid crystal cell was set to 23 ° C., 60 ° C., and 90 ° C., and the measurement was performed at each temperature.
[Ion density]
The ion density of the liquid crystal cell was measured as follows.
Measurement was performed using a 6254 type liquid crystal property evaluation apparatus manufactured by Toyo Technica. A triangular wave of 10 V and 0.01 Hz was applied, and an area corresponding to the ion density of the obtained waveform was calculated by a triangle approximation method to obtain an ion density.

Synthesis Example 1 Synthesis of 4- (2- (methylamino) ethyl) aniline In a 300 mL four-necked flask, 100.0 g (461.6 mmol) of N-methyl-2- (4-nitrophenyl) ethylamine hydrochloride, pure 200 g (11.1 mol) of water and 2.31 g (46.16 mmol) of hydrazine hydrate were charged and the hydrochloride was dissolved at 80 ° C. in a nitrogen atmosphere, and then 35.08 g (877.0 mmol) of 3N aqueous sodium hydroxide solution was dissolved. ) And stirred at 80 ° C. for 9 hours. Subsequently, the reaction solution separated into two layers was extracted with ethyl acetate, water was removed with anhydrous magnesium sulfate, and filtration and concentration by an evaporator gave 80.31 g of a red-orange liquid (yield 94.0). %).

  Subsequently, 78.52 g (435.7 mmol) of the reddish orange liquid obtained in a 2 L four-necked flask, 1099 g (34.30 mol) of methanol, and 7.85 g of 5 mass% palladium-carbon (hydrated product) were charged, and hydrogen was added. While feeding, the mixture was stirred at room temperature for 1 week. The reaction was monitored by thin layer chromatography TLC (ethyl acetate, before reaction: Rf = 0.2, after reaction: Rf = 0). After completion of the reaction, the mixture was filtered through Celite and concentrated with an evaporator to obtain a red solid. When the obtained solid was purified by distillation under reduced pressure (boiling point: 120 Pa, 104 ° C.), 42.27 g of white crystals were obtained (yield 64.6%).

The obtained white crystals were subjected to ¹ H-NMR measurement to confirm that the target diamine was produced.
¹ H-NMR data
1.2ppm 1H (br), 2.4ppm 3H (s), 2.7-2.8ppm 4H (m), 3.6ppm 2H (br), 6.6, 7.0ppm 4H (dd)
In addition, said measuring apparatus and measurement conditions are as follows.
Apparatus: Fourier transform type superconducting nuclear magnetic resonance apparatus (FT-NMR) INOVA-400 (manufactured by Varian) 400 MHz
Solvent: deuterated chloroform (CDCl ₃ )
Standard substance: Tetramethylsilane (TMS)
Integration count: 8

(Synthesis Example 2) CBDA / Me-4APhA
4- (2- (methylamino) ethyl) aniline (2.40 g, 16.0 mmol) is taken into a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, and 20 g of N-methyl-2-pyrrolidone is added. Was dissolved by stirring while feeding. While stirring the diamine solution, 3.07 g (15.7 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride was added, and N-methyl- was added so that the solid content concentration became 12% by mass. 2-Pyrrolidone was added and stirred at room temperature for 2 hours under a nitrogen atmosphere to obtain a solution of polyamic acid (A-1). The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 258 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 17,700 and Mw = 43,900.

(Synthesis Example 3) CBDA / Me-DDM
In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 4.03 g (19.0 mmol) of N-methyl-4,4′-diaminodiphenylmethane was added, 20 g of N-methyl-2-pyrrolidone was added, and nitrogen was added. While feeding, the mixture was dissolved by stirring. While stirring the diamine solution, 3.69 g (18.8 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride was added, and N-methyl- was added so that the solid concentration was 15% by mass. 2-Pyrrolidone was added and stirred at room temperature for 24 hours under a nitrogen atmosphere to obtain a solution of polyamic acid (A-2). The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 413 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 21,300 and Mw = 50,900.

(Synthesis Example 4) CBDA / 4APhA
While taking 5.45 g (40.0 mmol) of 4- (2-aminoethyl) aniline in a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, add 42 g of N-methyl-2-pyrrolidone and feed nitrogen. Stir to dissolve. While stirring this diamine solution, 7.53 g (38.4 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride was added, and N-methyl- was added so that the solid content concentration became 15% by mass. 2-Pyrrolidone was added and stirred at room temperature for 2 hours to obtain a solution of polyamic acid (B-1). The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 493 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 13,200 and Mw = 30,700.

(Synthesis Example 5) CBDA / DDM
To a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, take 4.77 g (19.0 mmol) of 4,4′-diaminodiphenylmethane, add 20 g of N-methyl-2-pyrrolidone, and stir while feeding nitrogen. And dissolved. While stirring the diamine solution, 3.61 g (18.4 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride was added, and N-methyl- was added so that the solid concentration was 15% by mass. 2-Pyrrolidone was added and stirred at room temperature for 24 hours to obtain a solution of polyamic acid (B-2). The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 398 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 15,900 and Mw = 34,400.

(Synthesis Example 6) CBDA / Me-4APhA, DDM (50)
1.50 g (10.0 mmol) of 4- (2- (methylamino) ethyl) aniline and 1.98 g (10.0 mmol) of 4,4′-diaminodiphenylmethane in a 50 mL four-necked flask with a stirrer and a nitrogen inlet tube ), 20 g of N-methyl-2-pyrrolidone was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution, 3.82 g (19.5 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride was added, and N-methyl- was added so that the solid content concentration became 15% by mass. 2-Pyrrolidone was added and stirred for 2 hours at room temperature under a nitrogen atmosphere to obtain a solution of polyamic acid (A-3). The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 414 mPa · s.

(Synthesis Example 7) CBDA (50), PMDA / Me-4APhA, DDM (50)
1.50 g (10.0 mmol) of 4- (2- (methylamino) ethyl) aniline and 1.98 g (10.0 mmol) of 4,4′-diaminodiphenylmethane in a 50 mL four-necked flask with a stirrer and a nitrogen inlet tube ), 18 g of N-methyl-2-pyrrolidone was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution, 1.96 g (10.0 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 12 g of N-methyl-2-pyrrolidone were added. One hour later, pyromellitic acid was added. 2.07 g (9.5 mmol) of dianhydride was added, N-methyl-2-pyrrolidone was further added so that the solid content concentration was 15% by mass, and the mixture was stirred at room temperature for 1 hour in a nitrogen atmosphere to polyamic acid. A solution of (A-4) was obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 447 mPa · s.

(Synthesis Example 8) CBDA (70), PMDA / Me-4APhA, DDM (50)
1.50 g (10.0 mmol) of 4- (2- (methylamino) ethyl) aniline and 1.98 g (10.0 mmol) of 4,4′-diaminodiphenylmethane in a 50 mL four-necked flask with a stirrer and a nitrogen inlet tube ), 18 g of N-methyl-2-pyrrolidone was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution, 2.75 g (14.0 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 12 g of N-methyl-2-pyrrolidone were added. One hour later, pyromellitic acid was added. 1.21 g (5.5 mmol) of dianhydride was added, N-methyl-2-pyrrolidone was further added so that the solid content concentration was 15% by mass, and the mixture was stirred at room temperature for 1 hour in a nitrogen atmosphere to be polyamic acid. (A-5) A solution was obtained. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 459 mPa · s.

(Synthesis Example 9) CBDA / DA-5MG
To a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, take 2.86 g (10.0 mmol) of 1,5-bis (4-aminophenoxy) pentane, add 20 g of N-methyl-2-pyrrolidone, and add nitrogen. Was dissolved by stirring while feeding. While stirring the diamine solution, 1.86 g (9.5 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride was added, and N-methyl- was added so that the solid content concentration became 10% by mass. 2-Pyrrolidone was added and stirred at room temperature for 2 hours under a nitrogen atmosphere to obtain a solution of polyamic acid (B-3). The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 140 mPa · s. Moreover, the molecular weight of this polyamic acid was Mn = 16,800 and Mw = 44,200.

<Example 1>
12.99 g of the polyamic acid (A-1) solution obtained in Synthesis Example 2 was dispensed into a 50 mL Erlenmeyer flask containing a stirring bar, 7.23 g of N-methyl-2-pyrrolidone, 5.06 g of butyl cellosolve and 3 -Aminopropyltriethoxysilane 0.03g was added, and it stirred for 30 minutes with the magnetic stirrer, and obtained the liquid crystal aligning agent of this invention.
The liquid crystal aligning agent is filtered through a 1.0 μm filter, spin-coated on a glass substrate with a transparent electrode, dried for 5 minutes on a hot plate at a temperature of 80 ° C., and baked at a temperature of 220 ° C. for 30 minutes. A polyimide film having a thickness of 100 nm was obtained. This polyimide film is rubbed with a rayon cloth (roll diameter: 120 mm, rotation speed: 700 rpm, moving speed: 20 mm / sec, pushing amount: 0.4 mm), washed by irradiating with ultrasonic waves in pure water for 1 minute, and air blow After removing the water droplets at, the substrate was dried at 80 ° C. for 10 minutes to obtain a substrate with a liquid crystal alignment film. Two substrates with such a liquid crystal alignment film are prepared, a spacer of 50 μm is set on the liquid crystal alignment film surface of one substrate, and then the rubbing directions of the two substrates are combined so as to be anti-parallel. The periphery was sealed, leaving an empty cell with a cell gap of 50 μm. Liquid crystal (MLC-2003, manufactured by Merck & Co., Inc.) was vacuum-injected into this empty cell at room temperature, and the inlet was sealed to obtain an anti-parallel liquid crystal cell.

  When the alignment state of the liquid crystal cell was observed with a polarizing microscope, it was confirmed that the liquid crystal cell had a uniform alignment without defects. Further, for this liquid crystal cell, the pretilt angle of the liquid crystal was measured immediately after the cell preparation and after heating at a temperature of 105 ° C. for 10 minutes. As a result, the pretilt angle immediately after cell preparation was 1.2 degrees, and the pretilt angle after heating at a temperature of 105 ° C. for 10 minutes was 1.2 degrees.

In addition, two substrates with a liquid crystal alignment film prepared by the same procedure as described above were prepared, and a 6 μm spacer was sprayed on the liquid crystal alignment film surface of one of the substrates, and then the rubbing directions of the two substrates were antiparallel to 85. They were combined so that they were twisted, and the periphery was sealed leaving the liquid crystal injection port, and an empty cell having a cell gap of 6 μm was produced. Liquid crystal (MLC-2003, manufactured by Merck & Co., Inc.) was vacuum-injected into this empty cell at room temperature, and the injection port was sealed to obtain a twisted nematic liquid crystal cell. When the alignment state of the liquid crystal cell was observed with a polarizing microscope, it was confirmed that the liquid crystal cell had a uniform alignment without defects. As a result of measuring the voltage holding ratio of the liquid crystal cell and then measuring the ion density, the voltage holding ratio was 99.5% at a temperature of 23 ° C, 98.9% at a temperature of 60 ° C, and 95.95 at a temperature of 90 ° C. The ion density was 8 pC / cm ² .

<Comparative Example 1>
40.94 g of the solution of polyamic acid (B-1) obtained in Synthesis Example 4 was dispensed into a 100 mL Erlenmeyer flask containing a stirring bar, and 34.82 g of N-methyl-2-pyrrolidone, 18.97 g of butyl cellosolve and 3 -Aminopropyltriethoxysilane 0.11g was added, and it stirred for 30 minutes with the magnetic stirrer, and obtained the liquid crystal aligning agent for a comparison.
An anti-parallel liquid crystal cell and a twisted nematic liquid crystal cell were prepared in the same manner as in Example 1 except that this liquid crystal aligning agent was used. The liquid crystal alignment state was confirmed, and the pretilt angle, voltage holding ratio, and ion density of the liquid crystal were checked. Measurements were made.

  It was confirmed that the liquid crystal was uniformly aligned without defects in both the anti-parallel liquid crystal cell and the twisted nematic liquid crystal cell. The pretilt angle of the anti-parallel liquid crystal cell was 1.9 degrees immediately after the cell was produced, and 2.0 degrees after heating at a temperature of 105 ° C. for 10 minutes. That is, the liquid crystal aligning agent composed of polyamic acid (A-1) using N-methyldiamine has a lower pretilt angle than the liquid crystal aligning agent composed of polyamic acid (B-1) having the same structure except for the N-methyl group. It was confirmed that it was obtained.

Furthermore, the voltage holding ratio of the twisted nematic liquid crystal cell was 99.2% at a temperature of 23 ° C., 95.7% at a temperature of 60 ° C., 84.0% at a temperature of 90 ° C., and the ion density was 119 pC / cm ^2. It was. That is, it was confirmed that the liquid crystal aligning agent made of polyamic acid (A-1) has improved voltage holding ratio and decreased ion density in addition to lowering the pretilt angle.

<Example 2>
14.50 g of the polyamic acid (A-2) solution obtained in Synthesis Example 3 was dispensed into a 50 mL Erlenmeyer flask containing a stirring bar, and 13.72 g of N-methyl-2-pyrrolidone, 7.07 g of butyl cellosolve and 3 -0.05 g of aminopropyltriethoxysilane was added and stirred for 30 minutes with a magnetic stirrer to obtain the liquid crystal aligning agent of the present invention.
This liquid crystal aligning agent is filtered through a 1.0 μm filter, spin-coated on a glass substrate with a transparent electrode, dried for 5 minutes on a hot plate at a temperature of 80 ° C., and baked at a temperature of 230 ° C. for 50 minutes. A polyimide film having a thickness of 100 nm was obtained. This polyimide film is rubbed with a rayon cloth (roll diameter: 120 mm, rotation speed: 300 rpm, moving speed: 20 mm / sec, pushing amount: 0.4 mm), washed by irradiating with ultrasonic waves in pure water for 1 minute, and air blow After removing the water droplets at, the substrate was dried at a temperature of 80 ° C. for 10 minutes to obtain a substrate with a liquid crystal alignment film. Two substrates with such a liquid crystal alignment film were prepared, an anti-parallel liquid crystal cell was prepared in the same procedure as in Example 1, and the alignment state of the liquid crystal was confirmed and the pretilt angle of the liquid crystal was measured. As a result, it was confirmed that the liquid crystal had a uniform alignment with no defects, and the pretilt angle of the liquid crystal was 1.4 degrees immediately after the cell fabrication and 1.5 degrees after heating at a temperature of 105 ° C. for 10 minutes. .

In addition, two substrates with a liquid crystal alignment film prepared by the same procedure as described above were prepared, a twisted nematic liquid crystal cell was prepared by the same procedure as in Example 1, and the confirmation of the alignment state of the liquid crystal and the voltage holding ratio were confirmed. Measurement was performed, and then ion density was measured. As a result, it was confirmed that the liquid crystal had a uniform alignment without defects, and the voltage holding ratio was 99.5% at a temperature of 23 ° C., 98.6% at a temperature of 60 ° C., and 95.0% at a temperature of 90 ° C. And the ion density was 16 pC / cm ² .

<Comparative example 2>
Synthesis Example 5 14.10 g of the obtained polyamic acid (B-2) solution was taken into a 50 mL Erlenmeyer flask containing a stirring bar, and 13.57 g of N-methyl-2-pyrrolidone, 6.93 g of butyl cellosolve and 3- 0.04 g of aminopropyltriethoxysilane was added and stirred for 30 minutes with a magnetic stirrer to obtain the liquid crystal aligning agent of the present invention.
An anti-parallel liquid crystal cell and a twisted nematic liquid crystal cell were prepared in the same manner as in Example 2 except that this liquid crystal aligning agent was used. Confirmation of the alignment state of the liquid crystal and the pretilt angle, voltage holding ratio, and ion density of the liquid crystal were confirmed. Measurements were made.

  It was confirmed that the liquid crystal was uniformly aligned without defects in both the anti-parallel liquid crystal cell and the twisted nematic liquid crystal cell. The pretilt angle of the anti-parallel liquid crystal cell was 1.7 degrees immediately after the cell was produced, and 1.9 degrees after heating at a temperature of 105 ° C. for 10 minutes. That is, the liquid crystal aligning agent made of polyamic acid (A-2) using N-methyldiamine has a lower pretilt angle than the liquid crystal aligning agent made of polyamic acid (B-2) having the same structure except for the N-methyl group. It was confirmed that it was obtained.

Furthermore, the voltage holding ratio of the twisted nematic liquid crystal cell was 99.4% at a temperature of 23 ° C., 98.4% at a temperature of 60 ° C., 94.6% at a temperature of 90 ° C., and the ion density was 43 pC / cm ^2. It was. That is, it was confirmed that the liquid crystal aligning agent made of polyamic acid (A-2) has improved voltage holding ratio and decreased ion density in addition to lowering the pretilt angle.

<Example 3>
Using the solution of polyamic acid (A-3) obtained in Synthesis Example 6, N-methyl-2-pyrrolidone, butyl cellosolve and 3-aminopropyltriethoxysilane were added and stirred in the same procedure as in Example 2. The liquid crystal aligning agent of this invention was obtained.
This liquid crystal aligning agent is filtered through a 1.0 μm filter, spin-coated on a glass substrate with a transparent electrode, dried for 5 minutes on a hot plate at a temperature of 80 ° C., and baked at a temperature of 230 ° C. for 30 minutes. A polyimide film having a thickness of 100 nm was obtained. This polyimide film is rubbed with a rayon cloth (roll diameter: 120 mm, rotation speed: 1000 rpm, moving speed: 20 mm / sec, pushing amount: 0.4 mm), cleaned by irradiating with ultrasonic waves in pure water for 1 minute, and air blow After removing the water droplets at, the substrate was dried at a temperature of 80 ° C. for 10 minutes to obtain a substrate with a liquid crystal alignment film. Two substrates with such a liquid crystal alignment film are prepared, and a 6 μm spacer is spread on the liquid crystal alignment film surface of one of the substrates, and then combined so that the rubbing directions of the two substrates are antiparallel to each other. The periphery was sealed, and an empty cell with a cell gap of 6 μm was produced. Liquid crystal (MLC-2041, manufactured by Merck & Co., Inc.) was vacuum-injected into this empty cell at room temperature, and the inlet was sealed to obtain an anti-parallel liquid crystal cell.

  When the alignment state of the liquid crystal cell was observed with a polarizing microscope, it was confirmed that the liquid crystal cell had a uniform alignment without defects. With respect to this liquid crystal cell, the pretilt angle of the liquid crystal was measured immediately after the cell preparation and after heating at a temperature of 90 ° C. for 30 minutes. As a result, the pretilt angle immediately after cell preparation was 0.8 degree, and the pretilt angle after heating for 30 minutes at 90 ° C. was 0.9 degree.

Moreover, the voltage holding rate was measured using the antiparallel liquid crystal cell produced in the same procedure as the above, and then the ion density was measured. As a result, the voltage holding ratio was 99.5% at a temperature of 23 ° C., 99.0% at a temperature of 60 ° C., 97.0% at a temperature of 90 ° C., and the ion density was 6 pC / cm ² .

<Example 4>
A liquid crystal aligning agent was prepared in the same manner as in Example 3 except that the polyamic acid (A-4) solution obtained in Synthesis Example 7 was used, and an antiparallel liquid crystal cell was prepared. Confirmation and measurement of the pretilt angle, voltage holding ratio, and ion density of the liquid crystal were performed. As a result, it was confirmed that the liquid crystal had a uniform alignment with no defects, and the pretilt angle of the liquid crystal was 1.1 degrees immediately after the cell preparation and 1.2 degrees after heating at 90 ° C. for 30 minutes. . The voltage holding ratio was 99.5% at a temperature of 23 ° C., 99.1% at a temperature of 60 ° C., 96.5% at a temperature of 90 ° C., and the ion density was 11 pC / cm ² .

<Example 5>
A liquid crystal aligning agent was prepared in the same manner as in Example 3 except that the solution of polyamic acid (A-5) obtained in Synthesis Example 8 was used, and an antiparallel liquid crystal cell was prepared. Confirmation and measurement of the pretilt angle, voltage holding ratio, and ion density of the liquid crystal were performed. As a result, it was confirmed that the liquid crystal had a uniform alignment with no defects, and the pretilt angle of the liquid crystal was 1.0 degree immediately after the cell preparation and 1.2 degree after heating at a temperature of 90 ° C. for 30 minutes. . The voltage holding ratio was 99.5% at a temperature of 23 ° C., 99.0% at a temperature of 60 ° C., 96.7% at a temperature of 90 ° C., and the ion density was 9 pC / cm ² .

<Comparative Example 3>
A liquid crystal aligning agent was prepared in the same manner as in Example 3 except that the polyamic acid (B-3) solution obtained in Synthesis Example 9 was used, and an antiparallel liquid crystal cell was prepared. Confirmation and measurement of the pretilt angle, voltage holding ratio, and ion density of the liquid crystal were performed. As a result, it was confirmed that the liquid crystal had a uniform alignment with no defects, and the pretilt angle of the liquid crystal was 1.5 degrees immediately after the cell preparation and 1.6 degrees after heating at a temperature of 110 ° C. for 60 minutes. . The voltage holding ratio was 97.6% at a temperature of 23 ° C., 96.1% at a temperature of 60 ° C., 93.8% at a temperature of 90 ° C., and the ion density was 858 pC / cm ² .

The liquid crystal aligning agent of the present invention is particularly useful for preparing a liquid crystal aligning film for a liquid crystal display element that requires a low pretilt angle such as an IPS mode or an FFS mode.

The entire contents of the specification, claims and abstract of Japanese Patent Application No. 2006-351448 filed on Dec. 27, 2006 are incorporated herein as the disclosure of the specification of the present invention. It is.

Claims (7)

Selected from the group consisting of a polymer obtained by reacting a diamine component containing an N-substituted diamine represented by the following formula (1) and tetracarboxylic dianhydride and a polymer obtained by imidizing this polymer. A liquid crystal aligning agent, which is a solution containing at least one kind of polymer.

However, substitution in the formula (1), R ₁ is a divalent organic group, a divalent linear hydrocarbon group having 1 to 5 carbon atoms, optional hydrogen atom of the hydrocarbon group is a methyl group Or an organic group represented by the following formula (2); R ₂ and R ₃ are a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, and R ₂ and R ₃ At least one is a hydrocarbon group having 1 to 4 carbon atoms.

(In the formula (2), A _{1 to} A ₄ are a hydrogen atom, a methyl group, a methoxy group, an isopropyl group, a carboxyl group, an N, N′-dipropylamino group, or an N, N′-diallylamino group,
Y _{1 to} Y ₄ are a single bond, a methylene group, a carbonyl bond, an ether bond, an ester bond, an amino bond, or an amide bond,
R ₄ is a divalent linear hydrocarbon group having 1 to 5 carbon atoms, or an organic group in which any hydrogen atom of this hydrocarbon group is substituted with a methyl group,
m _{1 to} m ₄ are each 0 or 1,
When m _{1 to} m ₄ are all 0,
X ₁ is a cyclohexyl ring, benzene ring, naphthalene ring, fluorene ring, carbazole ring, pyridine ring, piperidine ring, tolan skeleton, or stilbene skeleton,
When any one of m _{1 to} m ₄ is 1,
X _{1 to} X ₄ are a cyclohexyl ring, a benzene ring, or a piperidine ring. ) R ₁ in Formula (1) is an organic group represented by Formula (2), A ₁ in Formula (2) is a hydrogen atom, X ₁ is a benzene ring, and R ₄ is carbon number. A divalent linear hydrocarbon group having 1 to 5, Y ₂ is a single bond, m ₂ is 1, and m ₁ , m ₃ and m ₄ are 0. The liquid crystal aligning agent of 1. The liquid crystal aligning agent of Claim ₁ whose R1 in Formula (1) is a structure of following formula (3), Formula (4), Formula (5), Formula (7), or Formula (8).

(In Formula (3), n is 1 or 2.)

(In the formula (4), _{A 1} is a hydrogen atom, a methyl group, a methoxy group, an isopropyl group, a carboxyl group, N, N'- di-propylamino group, or N, N'- diallylamino group.)

(In the formula (5), R ₅ represents a single bond, an ether bond, an ester bond, an amide bond, amino bond, a carbonyl bond, ethenylene, an organic group represented by ethynylene, or the following formula (6), R ₆ and R ₇ is a hydrogen atom or a methyl group.)

(In the formula (6), _{Y 5} and _{Y 6} are each independently a single bond, an ether bond, an ester bond, an amide bond or an amino bond, or a carbonyl bond, _{R 8} is a divalent C1-5 Or an organic group in which any hydrogen atom of this hydrocarbon group is substituted with a methyl group.)

(In Formula (7), Y ₇ and Y ₈ are a single bond or an ether bond)

(In Formula (8), Y ₉ and Y ₁₀ are each independently a single bond or an ether bond, and R ₉ is a single bond, an ether bond, or an organic group represented by the following formula (9). .)

(In formula (9), Y ₁₁ and Y ₁₂ are single bonds or ether bonds, and R ₁₀ is a divalent linear hydrocarbon group having 1 to 5 carbon atoms, or any hydrogen atom of this hydrocarbon group. Is an organic group substituted with a methyl group.) The liquid crystal aligning agent in any one of Claims 1-3 whose structure is chosen from following formula (a)-(g).

  The liquid crystal aligning agent in any one of Claims 1-4 whose N-substituted diamine represented by Formula (1) is 5-80 mol% of a diamine component.   The liquid crystal aligning film obtained using the liquid crystal aligning agent in any one of Claims 1-5.   The liquid crystal display element which has a liquid crystal aligning film of Claim 6.