JP2002363280A - Polyamide, liquid crystal aligning agent varnish using the same, and liquid crystal display device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide electric characteristics of a liquid crystal display element such as orientation, current consumption value, voltage holding ratio and residual charge of a liquid crystal, or reliability of these characteristics for long-term use, and furthermore, to improve a liquid crystal display element. For display quality such as afterimage phenomenon and display unevenness, corresponding to the demand for higher performance, especially for liquid crystal alignment agents that greatly affect the characteristics of liquid crystal display elements, It is an object of the present invention to improve characteristics by focusing on a voltage holding ratio, a pretilt angle, and the like. A polyamide having a structural unit represented by the formula (1) and a liquid crystal aligning agent varnish containing the same. R ¹ in the formula (1) is 2 derived from a diamino compound.
R ² and R ³ are H or a monovalent organic group, Y ¹ and Y ² are alkylene having 1 to 5 carbon atoms, R ⁴
And R ⁵ is F or alkyl having 1 to 12 carbons. Embedded image

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel polyamide and a liquid crystal aligning agent varnish containing the same. More specifically, polyamides capable of further improving properties by being used in combination with other polymer compounds such as polyamic acid and soluble polyimide, and an excellent voltage holding ratio and a liquid crystal display element manufactured using the same. The present invention relates to a varnish that provides an appropriate pretilt angle.

[0002]

2. Description of the Related Art At present, a display device using a nematic liquid crystal is mainly used, and a TN type liquid crystal display device in which the liquid crystal is twisted by 90 °, usually a S liquid crystal device having a twist of 180 ° or more.
Using a TN type liquid crystal display element and a thin film transistor,
There is a so-called TFT type liquid crystal display element. Furthermore, in recent years, various types of displays such as a lateral electric field type IPS type liquid crystal display device having improved viewing angle characteristics, a VA type liquid crystal display device using a vertical alignment state, and an OCB type liquid crystal display element using a bend alignment state are used. Elements have also been put to practical use. The progress of the liquid crystal display element is not only advanced in these systems, but also the improvement of the peripheral materials is being actively performed to improve the characteristics of the liquid crystal display element. Also, the liquid crystal alignment agent is one of the important factors related to the display quality of the liquid crystal display element,
With the demand for higher quality display devices, the role of the liquid crystal alignment agent has been increasing.

At present, liquid crystal aligning agents mainly used are polyamic acid and polyimide-based aligning agents such as soluble polyimides which are used by imidizing polyamic acid. In addition to the polyimide-based aligning agent, a polyamide or a polyamide in which a hydrogen atom of an amide bond (CONH) of the polyamide is substituted with another group are also being studied. In addition, there are liquid crystal aligning agents that use a polymer compound that is obtained by blending a plurality of polymer compounds or by block copolymerization. However, at present, there are difficulties in electrical properties such as voltage holding ratio or liquid crystal alignment properties. is there. In the prior literature, various other polymer-based aligning agents have been studied. However, heat resistance, chemical resistance (liquid crystal resistance), coating properties, electrical properties, display characteristics, alignment stability of liquid crystals, and the like have been studied. They do not have well-balanced characteristics and are hardly practically used.

As liquid crystal display devices are widely used,
The electrical characteristics of the liquid crystal display device, such as the orientation of the liquid crystal represented by the pretilt angle of the liquid crystal, the current consumption value, the voltage holding ratio, the residual charge, etc. Higher performance is required for display quality such as phenomena and display unevenness. Among these characteristics, the required range of the pretilt angle of the liquid crystal differs depending on the driving method of the liquid crystal display element. For example, a pre-tilt angle of about 1 to 6 degrees is required for a TN type liquid crystal display element or a TFT type liquid crystal display element in which liquid crystal is twisted 90 degrees, and a pretilt angle of about 3 to 8 degrees is required for an STN type liquid crystal display element having a large twist angle. . However, the required value of the pretilt angle slightly varies depending on the application, and recently, the STN type liquid crystal display element may be required to have an angle of 2 to 3 degrees or 8 degrees or more. On the other hand, in the IPS type liquid crystal display element, since the liquid crystal moves in the horizontal direction with respect to the substrate, it is not necessary to increase the pretilt angle, and the pretilt angle may be about 1 to 3 degrees. Conversely, in a VA liquid crystal display element, 90
A pretilt angle near the degree is required, and a large pretilt angle of 5 to 20 degrees is required in the OCB type liquid crystal display element to stabilize the bend alignment state.

In addition to the pretilt angle, characteristics related to the alignment of the liquid crystal, such as alignment uniformity, alignment stability, and anchoring energy at the liquid crystal-alignment film interface, are also important because they greatly affect the performance of the liquid crystal display device. It is. Furthermore, the process margin of these characteristics in the manufacturing process of the liquid crystal display element is also important, and the pretilt angle and the orientation of the liquid crystal may vary depending on the drying conditions of the solvent after the application of the alignment agent or the annealing conditions after the injection of the liquid crystal. Being changed is a big problem.

[0006] With respect to STN-type liquid crystal display elements, particularly those of low voltage type used in the field of portable equipment, the driving voltage of the liquid crystal display element is low, so that the demand for current consumption is important. That is, when the current consumption value of the liquid crystal display element increases, the voltage applied to the liquid crystal relatively decreases, so that the rise of the liquid crystal becomes insufficient and the contrast decreases. In a low-voltage type liquid crystal display device, a change (reliability) in a current consumption value occurring during long-term use of the liquid crystal display device is also important. Display ON for STN type display element
Since -OFF is performed with a slight potential difference, if the current consumption value of the element changes, the voltage applied to the liquid crystal also changes, and normal driving cannot be performed. In an extreme case, even a phenomenon in which an image on the liquid crystal display element is not displayed at all may occur due to long-time driving.

On the other hand, for a TFT type liquid crystal display element,
In particular, characteristics regarding the voltage holding ratio and the residual charge are important.
If the voltage holding ratio is low, the voltage applied to the liquid crystal during the frame period decreases, and a problem occurs in that the contrast decreases. If the residual charge is large, turn off the voltage after applying the voltage.
However, the charge remains, and the image to be erased remains as an afterimage. In a TFT type liquid crystal display device, this afterimage phenomenon is one of quite important problems.

Further, as liquid crystal having a large dielectric anisotropy has been used in recent years as the driving voltage of the liquid crystal has been lowered, the fine Vth generated in the plane of the display has been reduced.
Irregularities have been regarded as a problem. In particular, if water washing is performed to remove shavings generated when the alignment film is rubbed, a phenomenon occurs in which traces of water washing remain as Vth unevenness (water washing unevenness), which is a serious problem.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display element having an appropriate pretilt angle and an excellent voltage holding ratio among various characteristics required for the above liquid crystal display element. It is an object of the present invention to provide a liquid crystal aligning agent varnish, and a novel polyamide for use in the varnish.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, a liquid crystal aligning agent varnish used for a liquid crystal display device contains a polyamide having the following structure. It has been found that the use thereof makes it possible to achieve a particularly suitable pretilt angle and a further improvement in the voltage holding ratio, and the present invention has been achieved based on these findings. That is, the present invention has the following configuration. (1) A polyamide having at least one structural unit represented by the formula (1).

Embedded image (Wherein, R ¹ is a divalent organic residue derived from a diamino compound, R ² and R ³ are each independently H or a monovalent organic group, and Y ¹ and Y ² are each independently A linear or branched alkylene having 1 to 5 carbon atoms;
⁴ and R ⁵ are each independently F or a group having 1 to 1 carbon atoms.
2, Y ¹ , Y ² ,
The bonding positions of R ⁴ and R ⁵ are arbitrary positions. The monovalent organic group is a linear or branched alkyl having 1 to 20 carbon atoms, or a substituted or unsubstituted alicyclic group, aromatic group or heterocyclic group, and these groups are O or It may be bonded to N through CO, and Si
Or any of H in these groups may be halogen, OH, NH ₂ , CN, a substituted or unsubstituted alicyclic group, an aromatic group or a heterocyclic group containing N. Or when the monovalent organic group is alkyl, the non-adjacent CH ₂ in the alkyl may be substituted with O, CH = CH or C≡C. When the alkyl is bonded to N via O, O is not continuous. (2) R ¹ in the structural unit represented by the formula (1) is a group selected from the group consisting of a group represented by the formula (2) and a group represented by the formula (3) The polyamide according to the above (1).

Embedded image (Wherein, R ⁶ is H or alkyl having 1 to 12 carbons, ring A is a benzene ring or cyclohexane ring, Z is a single bond,
CH ₂ , CH ₂ CH ₂ or O, r is 0 to 3, s
Is an integer of 0 to 5 and t is an integer of 0 to 3;
In the case of to 3, a plurality of Z may be the same or different from each other. Further, H on any benzene ring or cyclohexane ring may be substituted with alkyl having 1 to 4 carbon atoms. )

Embedded image (Wherein X ¹ and X ² are each independently a single bond,
O, COO, OCO, NH, CONH or carbon number 1
12 is an alkylene, B ¹ and B ² each independently represent a single bond or a divalent group containing 1 to 3 rings selected from an aromatic ring and an alicyclic ring, and R ⁷ is H ,
It represents F, CN, OH or alkyl, fluoroalkyl or alkoxy having 1 to 12 carbon atoms. The position of the substituent and the position of the two free radicals on the benzene ring are arbitrary positions. (3) The method according to the above (2), wherein R ¹ in the structural unit represented by the formula (1) is a group selected from the group consisting of groups represented by the formula (2). polyamide. (4) The polyamide according to the above (2), wherein R ¹ in the structural unit represented by the formula (1) is a group selected from the group consisting of groups represented by the formula (3). . (5) A liquid crystal aligning agent varnish comprising at least one polyamide having at least one structural unit represented by the formula (11).

Embedded image (Wherein, R ¹ is a divalent organic residue derived from a diamino compound, R ² and R ³ are each independently H or a monovalent organic group, and Y ¹ and Y ² are each independently A linear or branched alkylene having 1 to 5 carbon atoms;
⁴ and R ⁵ are each independently F or a group having 1 to 1 carbon atoms.
2, Y ¹ , Y ² ,
The bonding positions of R ⁴ and R ⁵ are arbitrary positions. The monovalent organic group is a linear or branched alkyl having 1 to 20 carbon atoms, or a substituted or unsubstituted alicyclic group, aromatic group or heterocyclic group, and these groups are O or It may be bonded to N through CO, and Si
Or any of H in these groups may be halogen, OH, NH ₂ , CN, a substituted or unsubstituted alicyclic group, an aromatic group or a heterocyclic group containing N. Or when the monovalent organic group is alkyl, the non-adjacent CH ₂ in the alkyl may be substituted with O, CH = CH or C≡C. When the alkyl is bonded to N via O, O is not continuous. (6) R ¹ in the structural unit represented by the formula (11) is
The liquid crystal aligning agent varnish according to the above item (5), which is a group selected from the group consisting of a group represented by the formula (2) and a group represented by the formula (3).

Embedded image (Wherein, R ⁶ is H or alkyl having 1 to 12 carbons, ring A is a benzene ring or cyclohexane ring, Z is a single bond,
CH ₂ , CH ₂ CH ₂ or O, r is 0 to 3, s
Is an integer of 0 to 5 and t is an integer of 0 to 3;
In the case of to 3, a plurality of Z may be the same or different from each other. Further, H on any benzene ring or cyclohexane ring may be substituted with alkyl having 1 to 4 carbon atoms. )

Embedded image (Wherein X ¹ and X ² are each independently a single bond,
O, COO, OCO, NH, CONH or carbon number 1
12 is an alkylene, B ¹ and B ² each independently represent a single bond or a divalent group containing 1 to 3 rings selected from an aromatic ring and an alicyclic ring, and R ⁷ is H ,
It represents F, CN, OH or alkyl, fluoroalkyl or alkoxy having 1 to 12 carbon atoms. The position of the substituent and the position of the two free radicals on the benzene ring are arbitrary positions. (7) R ¹ in the structural unit represented by the formula (11) is
The liquid crystal aligning agent varnish according to the above (6), which is a group selected from the group consisting of groups represented by the formula (2). (8) R ¹ in the structural unit represented by the formula (11) is
The liquid crystal aligning agent varnish according to the above (6), which is a group selected from the group consisting of groups represented by the formula (3). (9) The above (5) for all amide groups in the polyamide.
(5) to (8), wherein the ratio of the amide group in which H is substituted by at least one of the monovalent organic groups described in the above item is from 0.3 to 1 in molar ratio. The liquid crystal aligning agent varnish according to any one of the above. (10) Polyamic acid, soluble polyimide and the formula (1)
The liquid crystal according to any one of the above items (5) to (9), comprising at least one polymer compound selected from polyamides containing no structural unit shown in 1). Alignment agent varnish. (11) The concentration of the polymer compound component is 0.1 to 40% by weight.
The liquid crystal aligning agent varnish according to any one of the above items (5) to (10), wherein: (12) A liquid crystal display device comprising the liquid crystal aligning agent varnish according to any one of the above (5) to (11).

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The polyamide having a structural unit represented by the formula (1) of the present invention is a dicarboxylic acid represented by the formula (4) or an acid dihalide thereof (hereinafter, these are collectively referred to as dicarboxylic acids). Is used as a raw material component.

Embedded image (The meaning of Y ¹ , Y ² , R ⁴ and R ⁵ in the formula, and the bonding position of these groups to the benzene ring are the same as those in the above formula (1).)

The dicarboxylic acids represented by the formula (4) include benzene diacetate, 1- (carboxymethylphenyl) propionic acid, 2- (carboxymethylphenyl) propionic acid, 1- (carboxymethylphenyl) butyric acid, and 2- (carboxymethylphenyl) butyric acid. Carboxymethylphenyl) butyric acid, 1- (carboxymethylphenyl) valeric acid, 2- (carboxymethylphenyl) valeric acid, 1- (carboxymethylphenyl) hexanoic acid, 2- (carboxymethylphenyl) hexanoic acid,
3- (carboxymethylphenyl) hexanoic acid, benzenedipropionic acid, 2- (carboxyethylphenyl)
Propionic acid, 1- (carboxyethylphenyl) butyric acid, 2- (carboxyethylphenyl) butyric acid, 1- (carboxyethylphenyl) valeric acid, 2- (carboxyethylphenyl) valeric acid, 1- (carboxyethylphenyl) hexanoic acid 2- (carboxyethylphenyl) hexanoic acid, 3- (carboxyethylphenyl) hexanoic acid, benzenediisopropionic acid, 1- (carboxy (methyl) methyl-phenyl) butyric acid, 2- (carboxy (methyl) methyl-phenyl) ) Butyric acid, 1- (carboxy (methyl) methyl-phenyl) valeric acid, 2- (carboxy (methyl) methyl-phenyl) valeric acid, 1- (carboxy (methyl) methyl-phenyl) hexanoic acid, 2-
(Carboxy (methyl) methyl-phenyl) hexanoic acid, 3- (carboxy (methyl) methyl-phenyl) hexanoic acid,

Benzenedibutyric acid, 2- (carboxypropylphenyl) butyric acid, 1- (carboxypropylphenyl) valeric acid, 2- (carboxypropylphenyl) valeric acid, 1- (carboxypropylphenyl) hexanoic acid,
2- (carboxypropylphenyl) hexanoic acid, 3-
(Carboxypropylphenyl) hexanoic acid, benzenediisobutyric acid, 1-((2-carboxy-1-methyl) ethylphenyl) valeric acid, 2-((2-carboxy-1-
Methyl) ethylphenyl) valeric acid, 1-((2-carboxy-1-methyl) ethylphenyl) hexanoic acid, 2-
((2-carboxy-1-methyl) ethylphenyl) hexanoic acid, 3-((2-carboxy-1-methyl) ethylphenyl) hexanoic acid, benzenedivalic acid, 2- (carboxybutylphenyl) valeric acid, -(Carboxybutylphenyl) hexanoic acid, 2- (carboxybutylphenyl) hexanoic acid, 3- (carboxybutylphenyl) hexanoic acid, benzenediisovaleric acid, 1-((3-
Carboxy-1-methyl) propylphenyl) hexanoic acid, 2-((3-carboxy-1-methyl) propylphenyl) hexanoic acid, 3-((3-carboxy-1-methyl) propylphenyl) hexanoic acid, benzene Hexanoic acid, 2- (carboxypentylphenyl) hexanoic acid, 3- (carboxypentylphenyl) hexanoic acid,
Bis- (4-carboxy-1-methyl) benzene, 3-
For each of dicarboxylic acids such as (4-carboxy-1-methyl) butylphenylhexanoic acid and bis- (3-carboxy-1-ethyl) benzene, alkyl substituents having F or / and 1 to 12 carbon atoms are exemplified. be able to. The bonding positions of carboxyalkyl, F and alkyl to the benzene ring are arbitrary positions and are not particularly limited.

The above dicarboxylic acids and acid dihalides thereof may be used alone or in combination of two or more. Further, the dicarboxylic acids represented by the formula (4) can be used in combination with other dicarboxylic acids. Other dicarboxylic acids that can be used in the present invention may be those belonging to any of aromatic (including heterocyclic), alicyclic (including heterocyclic) and aliphatic groups. Although it is good, those having a ring structure are preferable in order to keep the orientation of the liquid crystal favorable. Therefore, when using an aliphatic dicarboxylic acid, it is preferable to use it in combination with an alicyclic and / or aromatic one.
In addition, the amount should be within a range that does not adversely affect the orientation. In addition, ether, ester, thioether,
It is preferable to use a dicarboxylic acid having no group such as a thioester in its structure, but there is no problem in using such a compound as long as the effect of the present invention is not affected.

Specific examples of the dicarboxylic acids which can be used in combination with the dicarboxylic acids of the formula (4) are shown below. As the aliphatic dicarboxylic acid, malonic acid, oxalic acid, dimethylmalonic acid, succinic acid, fumaric acid, glutaric acid, adipic acid, muconic acid, 2
-Methyladipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, 3,3-diethylsuccinic acid, azelaic acid, sebacic acid, suberic acid and the like.

Examples of the alicyclic dicarboxylic acid include cyclopropanedicarboxylic acid, cyclobutanedicarboxylic acid, diphenyl-cyclobutanedicarboxylic acid, bis (2-hydroxyphenyl) -cyclobutanedicarboxylic acid, cyclobutene-dicarboxylic acid, cyclopentanedicarboxylic acid, and cyclohexanedicarboxylic acid. , Norbornene-dicarboxylic acid,
Bicyclo [2.2.2] octanedicarboxylic acid, dioxo-bicyclo [2.2.2] octanedicarboxylic acid, adamantanedicarboxylic acid, dioxo-adamantandicarboxylic acid, spiro [3.3] heptanedicarboxylic acid, adamantanediacetic acid and Camphoric acid and the like can be mentioned.

As the aromatic dicarboxylic acid, phthalic acid,
Isophthalic acid and isophthalic acid in which any hydrogen on the benzene ring is substituted with alkyl, terephthalic acid and terephthalic acid in which any hydrogen on the benzene ring is substituted with alkyl, naphthalenedicarboxylic acid, anthracenedicarboxylic acid, anthraquinonedicarboxylic acid, Biphenyl dicarboxylic acid, ta-phenyl dicarboxylic acid, diphenyl methane dicarboxylic acid, diphenyl ethane dicarboxylic acid, diphenyl propane dicarboxylic acid, diphenyl hexafluoropropane dicarboxylic acid, diphenyl ether dicarboxylic acid, bibenzyl dicarboxylic acid, stilbene dicarboxylic acid, transdicarboxylic acid, benzophenone dicarboxylic acid Acid, carboxycinnamic acid, p-phenylenediacrylic acid,
Diphenylmethane dipropionic acid, diphenyl ether dibutyric acid, (isopropylidene di-p-phenylenedioxy) dibutyric acid, bis (p-carboxyphenyl) dimethylsilane, 9-oxofluorenedicarboxylic acid, furandicarboxylic acid, thiazoledicarboxylic acid, 2- Phenylthiazole dicarboxylic acid, furazane dicarboxylic acid, pyridine dicarboxylic acid and the like can be mentioned, and these dicarboxylic acids may be in the form of acid dihalide.

Among the above-mentioned dicarboxylic acids or their acid dihalides, considering the influence on the orientation of the liquid crystal,
Particularly preferred are dicarboxylic acids capable of giving a polyamide having a linear structure. And among such dicarboxylic acids, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, pyridinedicarboxylic acid, naphthalenedicarboxylic acid, 1,4-anthracenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, ,
4 "-tert-phenyldicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,4'-diphenylethanedicarboxylic acid, 4,4'-diphenylpropanedicarboxylic acid, 4,4'-diphenylhexafluoropropanedicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, or an acid dihalide thereof is preferably used.

For the purpose of improving the adhesion to the substrate and the like, the formula (5)

Embedded image Wherein R ¹¹ and R ¹² are each independently methyl, ethyl, phenyl or cyclohexyl;
u, v and w are each independently an integer of 1 to 5. ) Or a dihalide thereof.

Further, in order to increase the pretilt angle of the liquid crystal, a dicarboxylic acid or an acid dihalide thereof represented by the formula (6) or (7) may be used in combination.

Embedded image

Embedded image X ^{11 in} these formulas is a single bond, O, COO, OCO,
NH, NHCO, CONH, S or alkylene having 1 to 6 carbon atoms, R ¹³ is alkyl or fluoroalkyl having 3 to 20 carbon atoms, or a steroid group which may have a substituent, and R ¹⁴ and R ¹⁵ is each independently alkyl having 1 to 12 carbons, the total of which is 4 or more, and the bonding position of the carboxyl group to the benzene ring is an arbitrary position. And, as the steroid group, cholesteryl, androsteryl, β-cholesteryl, epiandrosteryl, ergosteryl, estrol, 11α-hydroxymethylsteryl, 11α-progesteryl, lanosteryl, melatranil, methyltestosterosteryl, norretosteryl, pregnenonyl, β-sitosteryl, stigmasteryl, testosteryl, cholesterol acetate and the like can be mentioned. The dicarboxylic acids that can be used in combination with the dicarboxylic acids represented by the formula (4) are not limited to these, and two or more of these can be used in combination.

The present invention relates to a polyamide having a structural unit represented by the above formula (1), and a polyamide having a structural unit represented by the formula (11) produced in exactly the same manner as this polyamide. It is a liquid crystal aligning agent varnish contained as a component. As the diamino compound which is a raw material of the polyamide, those having a side chain group are preferable in order to obtain a high pretilt angle. As the side chain group, an aliphatic hydrocarbon group, a hydrocarbon group containing an alicyclic structure, or an aromatic group And a diamino compound having a siloxane skeleton, a steroid skeleton-containing group, a side chain group in which these are combined, and the like. These hydrocarbon groups may have a part of their structure substituted by another atom such as oxygen, and alicyclic hydrocarbon groups and aromatic hydrocarbon groups include alkyl, alkoxy, halogen, OH And the like. In general, it is preferable to use a diamino compound that does not contain a group such as ether, ester, thioether, or thioester, which easily causes a decrease in the electrical properties of a liquid crystal display element. There is no problem in using such a diamino compound unless otherwise given.

The polyamide of the present invention has the formula (1)
Wherein R ¹ is a polyamide containing at least one structural unit which is a group selected from the group consisting of a group represented by the above formula (2) and a group represented by the above formula (3). Preferably, the liquid crystal aligning agent varnish of the present invention has the formula (1)
A polyamide containing at least one structural unit in which R ^{1 in} 1) is a group selected from the group consisting of a group represented by the above formula (2) and a group represented by the above formula (3),
It is a varnish containing one or more types. In the present invention,
A polyamide in which part or all of H in the amide group (in the structural unit represented by the formula (11), part or all of R ² and R ³ ) is a monovalent organic group (hereinafter, referred to as such Is sometimes referred to as an N-substituted polyamide.). However, as long as the object of the present invention is achieved, even a polyamide in which H in the amide group is not substituted at all can be used as a component of the liquid crystal aligning agent varnish of the present invention. In addition, other polymer compounds may be used in combination with the liquid crystal aligning agent varnish of the present invention, and in particular, a polyamic acid, a soluble polyimide, or a polyamide containing no structural unit represented by the formula (11) is used in combination. In some cases, the characteristics can be further improved, which is preferable. Of course, there is no problem even if the polyamide of the present invention is used alone.

A diamino compound giving a polyamide having a structural unit in which R ¹ in the formula (1) or (11) is a group represented by the above formula (2) is represented by the formula (8).

Embedded image (Wherein R ⁶ , ring A, s, r, Z and t are represented by formula (2)
Has the same meaning as in. )

Specific examples of the diamino compound represented by the formula (8) are shown in Tables 1 to 6 below as combinations of R ⁶ , rings A, Z, r, s and t. In the table, "B" indicates 1,4-phenylene, and "Ch" indicates 1,4-cyclohexylene.

[Table 1]

[0025]

[Table 2]

[0026]

[Table 3]

[0027]

[Table 4]

[0028]

[Table 5]

[0029]

[Table 6]

The above example is a part of the diamino compound represented by the formula (8), and does not mean that the diamino compound represented by the formula (8) is not limited to these examples.
For example, a compound in which Z is CH ₂ CH ₂ can be used,
Further, in the above example, only those having a so-called symmetrical structure in which two Zs are the same bonding group when t = 1 are shown. However, when t = 1 to 3, a plurality of Zs are different bonding groups. A group, a compound having an asymmetric structure can also be used. Also,
The diamino compound represented by the formula (8) can be used in combination of two or more. In these diamino compounds, in the case of an alignment film using a polyamide obtained from a material in which r is 0 and R ⁶ is H or short-chain alkyl, the pretilt angle is small, and r is 1 to 3. In the case of, the pretilt angle increases even when R ⁶ is H.

Further, R ¹ in the formula (1) is the same as the formula (3)
A diamino compound which gives a polyamide having a structural unit which is a group represented by the following formula is represented by the formula (9).

Embedded image (Wherein X ¹ , X ² , B ¹ , B ² and R ⁷ have the same meanings as in the above formula (3), and the bonding positions of the substituent and the two amino groups on the benzene ring are arbitrary. Specific examples of the diamino compound represented by the formula (9) include X ¹ ,
Tables 7 to 15 below show combinations of X ² , B ¹ , B ² and R ⁷ . "B" in the table is 1,4-
Phenylene, “Ch” is 1,4-cyclohexylene,
"-" Indicates a single bond, the bonding position of the two amino groups is the ^{1- and} 3-positions of benzene, and the bonding position of X1 is the 5-position of diaminobenzene. Further, for example, the column of ^{B 1} and ^{B 2} 'B
-Ch "and" Ch-B "are described.
It indicates that they are connected in the order of description.

[0032]

[Table 7]

[0033]

[Table 8]

[0034]

[Table 9]

[0035]

[Table 10]

[0036]

[Table 11]

[0037]

[Table 12]

[0038]

[Table 13]

[0039]

[Table 14]

[0040]

[Table 15]

The above example is a part of the diamino compound represented by the formula (9), and does not mean that the diamino compound represented by the formula (9) is limited to these examples. The diamino compound represented by the formula (9) can be used in combination of two or more. In these diamino compounds, when the number of rings contained in the substituent of diaminobenzene is large, or when X ¹ and X ² are long-chain alkylene and R ⁷ is long-chain alkyl, fluoroalkyl or alkoxy Has the effect of increasing the pretilt angle of the liquid crystal on an alignment film using a polyamide obtained using the same as a raw material.

The liquid crystal aligning agent varnish of the present invention uses, as a raw material, one or more diamino compounds selected from the group consisting of the diamino compound represented by the above formula (8) and the diamino compound represented by the above formula (9). It is preferable to use the polyamide of the present invention, and two or more of these polyamides may be used in combination. However, other than the diamino compounds represented by the formulas (8) and (9), any diamino compound having a side chain group can be suitably used. As an example of such a compound,
Examples thereof include diamino compounds having a steroidal substituent on the benzene ring of phenylenediamine.

Usually, an alignment film which gives a small pretilt angle to liquid crystal is suitable for an IPS type liquid crystal display device, and when the pretilt angle is about 3 to 8 °, it is suitable for a TN type liquid crystal display device. In the case of an STN liquid crystal display element, a VA liquid crystal display element, and an OCB liquid crystal display element, a larger pretilt angle may be required. In this case, a component having a longer side chain group may be used. The liquid crystal aligning agent varnish of the present invention may be referred to as a diamino compound represented by each of the formulas (8) and (9) and a diamino compound having another side chain group (hereinafter, may be referred to as a first diamino compound). The present invention uses the polyamide of the present invention obtained by using at least one selected from the above) as a preferable raw material. In the present invention, in order to adjust the pretilt angle to a required value, in addition to the first diamino compound, a diamino compound having no side chain group (hereinafter, may be referred to as a second diamino compound). ) May be used in combination. Examples of diamino compounds having no side chain group include
You can refer to what is described in many known documents,
As an example, WO 19/00732 A1
-20 pages and 34-37 pages. In addition, in connection with the diamino compounds described in this publication, those having a different bonding position of the amino group, those having a different number of carbon atoms of alkyl and / or alkylene in the structure, and those wherein arbitrary H is substituted by F And those in which the aromatic ring is substituted with a different number of alkyls. Furthermore, in addition to the above-mentioned diamino compounds, diamino compounds having a structure having an oxygen atom in alkylene can also be mentioned.

As described above, the second diamino compound used in the present invention can be arbitrarily selected from a large number of compounds and used, and two or more compounds can be used in combination. However, the aliphatic diamino compound among the second diamino compounds is preferably used within a range in which the orientation of the liquid crystal is kept good. Further, in order to keep the electrical properties of the liquid crystal display element high, it is preferable that the second diamino compound also has a structure not containing an ester group, an ether group, or a sulfur-containing group.

In the diamino compound which can be used in the present invention, the ratio between the first diamino compound and the second diamino compound is not uniform depending on the kind and the required pretilt angle, but (the first diamino compound / second diamino compound) Compound) (100/0) to (1/9)
9), and preferably (100/0) to (10/9).
0), more preferably (100/0) to (20/8)
0).

R ² and R ³ in the structural unit represented by the formula (1) or (11) are each independently H or a monovalent organic group. Amide groups other than the structural unit represented by 1) (-CO-
Also for NH-), its H may be substituted with a monovalent organic group. In the present invention, a polyamide having an amide group in which H is substituted with a monovalent organic group, that is, an N-substituted amide group is referred to as an N-substituted polyamide as described above. This one
Examples of the valent organic group include linear or branched alkyl having 1 to 20 carbon atoms, or a substituted or unsubstituted alicyclic group,
An aromatic group or a heterocyclic group can be mentioned. These organic groups may be linked to N via O or CO, and any H in these organic groups may be halogen, NH
_It may be substituted with ₂ , CN, or a substituted or unsubstituted alicyclic group, an aromatic group or a heterocyclic group containing N, or a steroid group. Non-adjacent CH ₂ in the alkyl may be substituted with O, CH ＝ CH or C≡C, but when this organic group is bonded to N via O, O is continuous. Never. Further, these organic groups may include Si or P. By introducing such a monovalent organic group into the polyamide to form an N-substituted polyamide, there is a great effect on the improvement of the electrical properties when used as a liquid crystal aligning agent varnish. For use in a liquid crystal aligning agent varnish, the ratio of N-substituted amide groups to all amide groups in the polyamide is preferably 0.3 to 1 in molar ratio. This ratio is more preferably 0.5 to 1, and 0.7
-1 is most preferred. However, as described above, a polyamide in which H in all amide groups is not substituted with a monovalent organic group may be used as long as the object of the present invention is achieved.

More specific examples of the above-mentioned monovalent organic group include methyl, ethyl, n-propyl, n-butyl, and n-butyl.
Pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-
Octadecyl, n-nonadecyl, n-eicosyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, Isohexyl, 1
Linear or branched alkyl such as -ethylpentyl, 2-ethylpentyl, 3-ethylpentyl, 4-ethylpentyl, 2,4-dimethylhexyl, 2,3,5-triethylheptyl,

Vinyl, ethynyl, 1-propenyl, 2-
Propenyl, isopropenyl, 2-butenyl, 1,3-
Butadienyl, 2-pentenyl, 2-penten-4-ynyl, 2-nonyl-2-butenyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, bicyclohexyl, cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl, cyclohexylmethyl, bicyclohexyl A group having an unsaturated bond or cycloalkane such as methyl, 2-cyclopenten-1-yl and 2,4-cyclopentadien-1-yl;

Phenyl, 2,6-dimethylphenyl,
2,6-diisopropylphenyl, biphenyl, triphenyl, terphenyl, benzyl, biphenylmethyl,
Triphenylmethyl, terphenylmethyl, 4-methylbenzyl, 4- (tert-butyl) benzyl, α-methylbenzyl, 1-naphthyl, 2-naphthyl, 9-anthrylmethyl, 5-phenyl-2,4-pentadiynyl Such as an aromatic group or a group having an aromatic ring,

Cholesteryl, androsteryl, β-cholesteryl, epiandrosteryl, erygosteryl,
Estoril, 11α-hydroxymethylsteryl, 11
groups having a steroid skeleton such as α-progesteryl, lanosteryl, melatranyl, methyltestosteryl, norethisteryl, pregnenonyl, β-sitosteryl, stigmasteryl, testosteryl, and cholesterol acetate;

Methoxy, ethoxy, propyloxy, butyloxy, pentyloxy, hexyloxy, methoxymethyl, methoxyethyl, methoxypropyl, methoxybutyl, methoxypentyl, methoxyhexyl, ethoxymethyl, ethoxyethyl, ethoxypropyl, ethoxybutyl, ethoxypentyl , Ethoxyhexyl, hexyloxymethyl, hexyloxyethyl, hexyloxypropyl, hexyloxybutyl, hexyloxypentyl, hexyloxyhexyl, phenoxy, benzyloxy, 4-methoxybenzyl, biphenyloxy, naphthyloxy, phenoxymethyl, benzyloxymethyl , Biphenyloxymethyl, naphthyloxymethyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, hydr Kishibuchiru, hydroxypentyl,
Hydroxyhexyl, furfuryl, (3-furyl) methyl, oxiranylmethyl, 2-methyloxiranylmethyl, 2-oxetanylmethyl, 3-oxetanylmethyl, oxolanylmethyl, dioxolanylmethyl, formyl, acetyl, benzoyl , Methoxycarbonyl, oxygen-containing groups such as phenylmethoxycarbonyl,

Trifluoromethyl, perfluoroethyl, n-perfluoropropyl, n-perfluorobutyl, n-perfluoropentyl, n-perfluorohexyl, n-perfluoroheptyl, n-perfluorooctyl, n-per Fluorononyl, n-perfluorodecyl, n-perfluoroundecyl, n-perfluorododecyl, n-perfluorotridecyl, n-perfluorotetradecyl, n-perfluoropentadecyl, n
Halogen-containing groups such as -perfluorohexadecyl, n-perfluoroheptadecyl, n-perfluorooctadecyl, n-perfluorononadecyl, n-perfluoroeicosyl, 4-trifluoromethylbenzyl,

Aminomethyl, aminoethyl, aminopropyl, aminobutyl, aminopentyl, aminohexyl, aminoheptyl, aminooctyl, aminononyl,
Aminodecyl, aminoundecyl, aminododecyl, aminotridecyl, aminotetradecyl, aminopentadecyl, aminohexadecyl, aminoheptadecyl, aminooctadecyl, aminononadecyl, aminoeicosyl, 2-aminoisopropyl, 3-aminoisobutyl,
2-pyridylmethyl, 3-pyridylmethyl, 4-pyridylmethyl, 2,2,6,6-tetramethyl-4-piperidinyl, 1,2,2,6,6-pentamethyl-4-piperidinyl, 2,2,2 6,6-tetramethyl-1- (2-
Propenyl) -4-piperidinyl, 1-methyl-2,5
-Dioxo-3-pyrrolidinyl, (1,2,3,6-tetrahydro-1,3-dimethyl-2,6-dioxo-7
H-purin-7-yl) methyl, cyano, cyanomethyl, cyanoethyl, cyanopropyl, cyanophenyl,
Cyanobiphenyl, cyanoterphenyl, cyanobenzyl, cyanophenylmethyl, cyanobiphenylmethyl,
Examples of the group include N, Si, or P-containing groups such as cyanoterphenylmethyl, trimethylsilyl, triethylsilyl, triphenylsilyl, 4-trimethylsilylbenzyl, dimethoxyphosphinylmethyl, and diethoxyphosphinylmethyl.

However, in order to keep the orientation of the liquid crystal particularly good, an organic group having a low flexibility and having 5 or less carbon atoms is preferable.
Ethyl, n-propyl, n-butyl, n-pentyl, isopropyl, isobutyl, sec-butyl, tert-
Butyl, isopentyl, neopentyl, tert-pentyl, vinyl, ethynyl, 1-propenyl, 2-propenyl, isopropenyl, 2-butenyl, 1,3-butadienyl, 2-pentenyl, 2-penten-4-yl, cyclopropyl, Cyclobutyl, cyclopentyl, cyclopropylmethyl, cyclobutylmethyl, 2-cyclopenten-1-yl, 2,4-cyclopentadien-1-yl, trifluoromethyl, perfluoroethyl, methoxy, ethoxy, propyloxy, butyloxy, pentyloxy , Methoxymethyl, methoxyethyl, methoxypropyl, methoxybutyl, ethoxymethyl, ethoxyethyl, ethoxypropyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl,
Hydroxypentyl, furfuryl, (3-furyl) methyl, oxiranylmethyl, 2-methyloxiranylmethyl, 2-oxetanylmethyl, 3-oxetanylmethyl, oxolanylmethyl, dioxolanylmethyl, formyl, acetyl, etc. preferable. These N substituents may be used in combination of two or more.

The N-substituted polyamide of the present invention can be obtained by one of the following two methods. One of them is
This is a method in which a diamino compound containing at least one of the above diamino compounds in which H of the amino group is substituted with one of the above organic groups and a dicarboxylic acid are polymerized (hereinafter, sometimes referred to as a pre-substitution method). The other one is a method in which after a diamino compound and a dicarboxylic acid are polymerized, H of an amide bond of the obtained polyamide is substituted with at least one of the above organic groups (hereinafter, referred to as a post-substitution method). There is.). Although any of the above methods can be applied, a diamino compound which is not substituted with N is superior in reactivity, so that the molecular weight of the produced polymer can be increased. As a result, it is preferable to use a liquid crystal alignment film because the film itself has good mechanical properties and can avoid defects such as abrasion or a disorder of the film in a rubbing step for imparting alignment. That is, the post-substitution method is more preferable.

The N-substituted diamino compound used in the pre-substitution method can be obtained by a known organic synthesis method, for example, by dehydration-condensing a diamino compound with an aldehyde such as propyl aldehyde or benzaldehyde or a ketone such as methyl ethyl ketone or cyclohexanone. A diamine compound, a method of reducing an amide group obtained by reacting a diamino compound with an acid halide such as acetyl chloride or benzoic acid chloride with lithium aluminum hydride or the like, and a method of reducing N-methyl See, for example, a method of reacting N-substituted anilines such as aniline, N, N-diphenylamine or N-methyl-3-aminotoluene with formaldehyde in the presence of an acid catalyst to obtain N, N'-substituted diaminodiphenylmethanes. Can be easily obtained.

On the other hand, in the post-substitution method, for example, a polyamide dissolved in a solvent such as dimethylsulfoxide, N-methylpyrrolidone, N, N-dimethylformamide or N, N-dimethylacetamide is treated with sodium methoxide, sodium hydride, hydrogen hydride, or the like. Potassium hydroxide, sodium hydroxide,
The reaction is carried out by reacting with a base such as potassium hydroxide, butyllithium or triethylamine, and then reacting with a halide of the above organic group.

In the production of polyamide, a diamino compound or an N-substituted diamino compound and a dicarboxylic acid are optionally added to (PhO) ₃ P, (PhO) PCl ₂ and PhPOC.
l ₂ or _{(C 3 H 7) 3 P} (O) a condensing agent of O, etc., pyridine, dimethyl sulfoxide, if necessary, N- methylpyrrolidone, N, N- dimethylformamide or N, the presence of a solvent such as N- dimethylacetamide Below, 2
The reaction can be carried out in the range of 0 to 300 ° C. When the reactivity is low, dicarboxylic acid dihalide is used instead of dicarboxylic acid, or N, N'-diacetyldiamine or N, N'- is used instead of diamino compound.
Bis (trimethylsilyl) diamine may be used.

The liquid crystal aligning agent varnish of the present invention essentially contains the above-mentioned polyamide, but it does not cause any problem even if other polymer compounds are used in combination as long as the effects of the present invention are not impaired. In particular, the use of another polymer compound may further improve the properties in some cases. Examples of such a polymer compound include materials such as polyamic acid, soluble polyimide, and polyamide which are generally used as a liquid crystal aligning agent varnish.

The liquid crystal aligning agent varnish of the present invention has the formula (11)
It is a varnish composition obtained by dissolving in a solvent a polymer compound containing a polyamide having a structural unit represented by the following formula as a main component, and is preferably used in combination with another polymer compound component. The other polymer compound component is preferably at least one polymer compound selected from a polyamic acid, a soluble polyimide, and a polyamide containing no structural unit represented by the formula (11). The concentration of the polymer compound in the liquid crystal aligning agent varnish is preferably 0.1 to 40% by weight. When applying the liquid crystal aligning agent varnish to the substrate, it may be necessary to dilute the varnish in advance with a solvent for film thickness adjustment, but the solvent can be uniformly mixed with the varnish, and In order to be able to dilute, it is necessary to keep the concentration of the polymer compound within a range not exceeding 40% by weight.

In order to maintain a good film thickness in the spinner method or the printing method, the content is usually set to 10% by weight or less. In other coating methods such as dipping, 1
The concentration may be even lower than 0% by weight. On the other hand, when the concentration of the polymer compound is less than 0.1% by weight, a problem that the thickness of the obtained liquid crystal alignment film becomes too thin tends to occur. Accordingly, the concentration of the polymer compound is 0.1% by weight or more, preferably 0.1% by a usual spinner method or printing method.
About 5 to 10% by weight is appropriate. However, depending on the method of applying the varnish, a lower concentration may be used.

The solvent used in the liquid crystal aligning agent varnish of the present invention may be any solvent having the ability to dissolve the high molecular compound, and there is no particular limitation. Therefore, it may be appropriately selected from solvents commonly used in the production process and application of polyamide, polyamic acid, and soluble polyimide according to the purpose of use. Examples of these solvents include aprotic polar organic solvents which are lipophilic to polyamide, polyamic acid, and soluble polyimide, such as N-methyl-2-pyrrolidone, dimethylimidozolidinone, N-methylcaprolactam, and N-methylpropion. Amide,
N, N-dimethylacetamide, dimethylsulfoxide, N, N-dimethylformamide, N, N-diethylformamide, diethylacetamide, γ-butyllactone, and the like can be used. Solvents such as alkyl lactate, 3-methyl-
3-methoxybutanol, tetralin, isophorone, ethylene glycol monoalkyl ether such as ethylene glycol monobutyl ether, diethylene glycol monoalkyl ether such as diethylene glycol monoethyl ether, ethylene glycol monoalkyl or phenyl acetate, triethylene glycol monoalkyl ether, propylene glycol mono Examples thereof include propylene glycol monoalkyl ethers such as butyl ether, dialkyl malonates such as diethyl malonate, dipropylene glycol monoalkyl ethers such as dipropylene glycol monomethyl ether, and ester compounds such as acetates thereof.

The liquid crystal aligning agent varnish of the present invention can contain various additives as necessary. For example, if it is desired to improve coatability, a surfactant for such purpose is used, if antistatic improvement is required, an antistatic agent is used, and if improvement in adhesion to a substrate is desired, a silane cup is used. A ring agent or a titanium-based coupling agent may be blended.

The liquid crystal aligning agent varnish obtained in this manner is suitable mainly for forming a liquid crystal aligning film for TFT, but can provide an appropriate pretilt, so that it can be used for ordinary TN type liquid crystal display devices. When forming a liquid crystal alignment film for an STN type liquid crystal display element, an IPS type liquid crystal display element, a VA type liquid crystal display element, an OCB type liquid crystal display element, a ferroelectric liquid crystal or an antiferroelectric liquid crystal display element Is also useful, and since it has excellent electrical characteristics as a liquid crystal display element, it can be used as a protective film, an insulating film, and the like.

A substrate on which a liquid crystal alignment film is formed using the liquid crystal alignment agent varnish of the present invention and a substrate on which a liquid crystal alignment film, which may be the same as or different from the substrate, are disposed so as to face each other. A liquid crystal display device can be formed by a known method by sandwiching a liquid crystal between the substrates. In the case of forming a liquid crystal alignment film, a step of applying a liquid crystal alignment agent varnish on a substrate, a subsequent drying step, and a step of performing a heat treatment required for a dehydration / ring closing reaction are performed. As a coating method, a spinner method, a printing method, a dipping method, a dropping method, and the like are generally known, and these methods can be similarly applied to the present invention. Further, as a method of a drying step and a step of performing a heat treatment required for a dehydration / ring closure reaction, a method of performing a heat treatment in an oven or an infrared furnace, a method of performing a heat treatment on a hot plate, and the like are generally known. These methods are equally applicable in the present invention.

The drying step is preferably performed at a relatively low temperature within a range in which the solvent can be evaporated, and the heat treatment step is generally performed at a temperature of about 150 to 300 ° C.

The liquid crystal composition used in the liquid crystal display device of the present invention is disclosed in, for example, JP-A-8-157828 and JP-A-8-231 for STN type liquid crystal display devices.
Liquid crystal compositions disclosed in JP-A-960-960, JP-A-9-241644, JP-A-9-302346 and the like are preferable, and are preferably used for TFT-type liquid crystal display devices (TN type, IPS type).
Type, VA type and OCB type) are described in JP-A-8-1991.
No. 68, JP-A-9-235552, JP-A-9-235552
JP-A-241643, JP-A-10-204016, JP-A-10-204436, JP-A-10-2
Liquid crystal compositions disclosed in JP-A-31482, JP-A-2000-087040 and the like are preferable, and it is preferable that the liquid crystal compositions are mainly composed of components used in these liquid crystal compositions. Further, the liquid crystal composition may contain at least one optically active compound for use.

[0068]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. Further, in the present embodiment, an example in which the polyamide of the present invention and a polyamic acid are used in combination for the purpose of further improving the properties is given, but as long as the effects of the present invention are not impaired, the polyamide is used alone. It doesn't matter at all. The raw material components and their abbreviations used in each example are shown below. <Dicarboxylic acid component> 1,4-phenylene diacetate: DAP 2,5-dimethyl-1,4-phenylene diacetate: MDAP 2,5-difluoro-1,4-phenylene diacetate: FDAP 1,4-phenylene Propionic acid: DPP Terephthalic acid: TPA <Tetracarboxylic dianhydride component> Pyromellitic dianhydride: PMDA Cyclobutanetetracarboxylic dianhydride: CBDA <Diamino compound component without side chain>4,4'-diaminodiphenylmethane : DPM 4,4'-diaminodiphenylethane: DPEt <Diamino compound component having a side chain group> 1,1-bis (4-((4-aminophenyl) methyl) phenyl) -4-butyl cyclohexane: 4CB1B1, 1-bis (4- (4-aminophenoxy) phenyl) -4- (4-pentyl Cyclohexyl) cyclohexane: 5CCBOB 5- (4- (4- (4-pentylcyclohexyl) cyclohexyl) phenyl) methyl-1,3-diaminobenzene: 5CCB1B <Solvent component> N-methyl-2-pyrrolidone: NMP butyl cellosolve: BC

Synthesis Example 1 (Synthesis of Polyamide) In a 300 ml four-necked flask equipped with a thermometer, a stirrer, a raw material charging port and a nitrogen gas inlet, 3.007 g of DAP, 1.933 g of DPM and 2.793 g 4CB1B, and put NM in this
102.7 g of P and 25.7 g of pyridine were added and stirred to form a uniform solution. To this, 10.24 g of triphenyl phosphite and 3 g of lithium chloride were sequentially added, and reacted at 90 ° C. for 2 hours. The reaction solution obtained was reprecipitated with methanol and pure water, and then dried under reduced pressure to obtain 6.1 g of polyamide. This polyamide is indicated by the symbol PA1. Table 1
The polyamides PA2 to PA10 were synthesized in exactly the same manner except that the raw materials were changed as shown in FIG.

Table 16 shows the raw material composition of the synthesized polyamide by mole fraction.

[Table 16]

Synthesis Example 2 (Synthesis of N-substituted polyamide) 1.0 g of polyamide PA1 and 1.0 g of dehydrated NMP were placed in a 100 ml four-necked flask equipped with a thermometer, a stirrer, a raw material charging port and a nitrogen gas inlet.
After adding 19.0 g and stirring at room temperature for a while, 0.376 g of sodium methoxide was added and stirring was further continued for 16 hours. 1.13 g of methyl iodide was added to this solution.
In addition, the reaction was further performed for 4 hours. From the obtained reaction solution, a polymer was obtained by reprecipitation in the same manner as in the case of the above-mentioned polyamide (PA1), and dried under reduced pressure to obtain 0.74 g of N-substituted polyamide. This is indicated by the symbol NPA1. Further, N-substituted polyamides NPA2 to NPA9 were prepared in exactly the same manner except that the raw material polyamide was changed as shown in Table 17.
And NPA14 were synthesized. The N-substituted polyamides NPA10 to NPA13 were synthesized using ethyl bromide, n-heptyl bromide, benzyl bromide, and anthryl methyl bromide instead of methyl iodide.
Table 17 also shows the weight average molecular weight of the obtained N-substituted polyamide.

[0072]

[Table 17]

Example 1 (1) Preparation of Varnish for Liquid Crystal Alignment Agent Varnish of N-substituted polyamide NPA1 obtained in Synthesis Example 2 was added to 18.0 g of the polyamic acid synthesized in Synthesis Example 3 (polymer concentration: 5% by weight). After adding and dissolving 10 g, the mixture was diluted with a diluting solvent to prepare a liquid crystal aligning agent varnish having a polymer concentration of 3%.

(2) Preparation of Cell for Evaluating Voltage Holding Ratio A liquid crystal aligning agent varnish using NPA1 was applied on a glass substrate with a transparent electrode ITO by a spinner, and the coating was performed at 80 ° C. for about 5 hours.
Preliminary baking for 250 minutes and heat treatment at 250 ° C. for 30 minutes. Next, an alignment process was performed by rubbing the surface of the substrate on which the alignment film was formed with a rubbing device. In the same process, another substrate is prepared, a gap material for 7 μ is scattered on the alignment film surface of one of the substrates, and the remaining substrates are overlapped with the surface on which the alignment film is formed being inward. The periphery was sealed with an epoxy curing agent except for the injection hole to produce an anti-parallel cell with a gap of 7 μm. The following liquid crystal composition as a liquid crystal material was injected into this cell, the injection port was sealed with a photocuring agent, and UV irradiation was performed to cure the liquid crystal injection hole.
Next, heat treatment was performed at 110 ° C. for 30 minutes to obtain a cell for evaluating residual charge and voltage holding ratio.

The composition of the liquid crystal composition used is shown below.
The NI point of this composition was 100.0 ° C., and the birefringence was 0.093.

Embedded image

(3) Preparation of Cell for Pretilt Angle Measurement In the above (2) Preparation of Cell for Voltage Holding Ratio,
Replace the gap material for μ with the gap material for 20μ,
A pretilt angle measurement cell was produced in the same manner as described above, except that an antiparallel cell having a cell thickness of 0 μm was produced. The same liquid crystal material as used in the measurement of the voltage holding ratio was used for the pretilt angle measurement.

(4) Evaluation of Liquid Crystal Cell The voltage holding ratio of the liquid crystal cell obtained above was measured by a known method (for example, described in “Mizushima et al., Proceedings of the 14th Liquid Crystal Discussion Group, p78”). . The measurement conditions were a gate width of 69 μs, a frequency of 60 HZ, and a wave height of ± 4.5 V.
The measurement temperature is 60 ° C. Also, the pretilt angle of the liquid crystal was measured by a crystal rotation method. Then, the cell at the time of measuring the pretilt angle was observed under a polarizing microscope, and the orientation was evaluated by examining the presence or absence of defective orientation. Table 18 shows the results.

Examples 2 to 13 and Comparative Example 1 Preparation of a liquid crystal aligning agent varnish, preparation of a liquid crystal cell for evaluation, and evaluation of the obtained cell were carried out in exactly the same manner as in Example 1 except that the N-substituted polyamide was changed. Was. Table 18 shows the results.

[Table 18]

From the above results, the voltage holding ratio of the liquid crystal aligning agent varnish of the present invention is all 98% or more, which is higher than the voltage holding ratio of the terephthalic acid-based polyamide of Comparative Example 1 when used. Understand. Further, it can be seen that the liquid crystal is given an appropriate pretilt angle, has good alignment characteristics, and is excellent in overall balance.

[0080]

By using the liquid crystal aligning agent varnish of the present invention, it is possible to obtain a liquid crystal display device having good alignment and coating properties, a pretilt angle that can be arbitrarily adjusted, and a high voltage holding ratio. The liquid crystal aligning agent varnish of the present invention is particularly preferably used in a TFT type liquid crystal display device (TN type, IPS type, VA type, OCB type), but has excellent electric characteristics and can optionally adjust the pretilt angle. Therefore, it can be used as an alignment agent for STN-type liquid crystal display devices, ferroelectric liquid crystals, and antiferroelectric liquid crystal display devices. In addition, a thin film of the present liquid crystal aligning agent varnish may be used as a protective film or an insulating film because of its excellent electrical properties.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H090 HB07Y HB08Y HB09Y KA05 KA08 LA04 MA11 4J001 DA01 DB01 DC05 DC12 DC15 EB34 EB35 EB36 EB37 EC24 EC44 EC74 EE18A JA07 JA17 JA20 4J038 DH021 DJ022 GA03 GA01 GA03 GA08

Claims (12)

[Claims] 1. A polyamide having at least one structural unit represented by the formula (1). Embedded image (Wherein, R ¹ is a divalent organic residue derived from a diamino compound, R ² and R ³ are each independently H or a monovalent organic group, and Y ¹ and Y ² are each independently A linear or branched alkylene having 1 to 5 carbon atoms;
⁴ and R ⁵ are each independently F or a group having 1 to 1 carbon atoms.
2, Y ¹ , Y ² ,
The bonding positions of R ⁴ and R ⁵ are arbitrary positions. The monovalent organic group is a linear or branched alkyl having 1 to 20 carbon atoms, or a substituted or unsubstituted alicyclic group, aromatic group or heterocyclic group, and these groups are O or It may be bonded to N through CO, and Si
Or any of H in these groups may be halogen, OH, NH ₂ , CN, a substituted or unsubstituted alicyclic group, an aromatic group or a heterocyclic group containing N. Or when the monovalent organic group is alkyl, the non-adjacent CH ₂ in the alkyl may be substituted with O, CH = CH or C≡C. When the alkyl is bonded to N via O, O is not continuous. ) (2) R ¹ in the structural unit represented by the formula (1):
Is a group selected from the group consisting of a group represented by the formula (2) and a group represented by the formula (3),
The polyamide according to claim 1. Embedded image (Wherein, R ⁶ is H or alkyl having 1 to 12 carbons, ring A is a benzene ring or cyclohexane ring, Z is a single bond,
CH ₂ , CH ₂ CH ₂ or O, r is 0 to 3, s
Is an integer of 0 to 5 and t is an integer of 0 to 3;
In the case of to 3, a plurality of Z may be the same or different from each other. Further, H on any benzene ring or cyclohexane ring may be substituted with alkyl having 1 to 4 carbon atoms. ) (Wherein X ¹ and X ² are each independently a single bond,
O, COO, OCO, NH, CONH or carbon number 1
12 is an alkylene, B ¹ and B ² each independently represent a single bond or a divalent group containing 1 to 3 rings selected from an aromatic ring and an alicyclic ring, and R ⁷ is H ,
It represents F, CN, OH or alkyl, fluoroalkyl or alkoxy having 1 to 12 carbon atoms. The position of the substituent and the position of the two free radicals on the benzene ring are arbitrary positions. ) 3. R ¹ in the structural unit represented by the formula (1)
Is a group selected from the group consisting of groups represented by the formula (2). 4. R ¹ in the structural unit represented by the formula (1)
Is a group selected from the group consisting of groups represented by the formula (3). 5. A liquid crystal aligning agent varnish comprising at least one polyamide having at least one structural unit represented by the formula (11). Embedded image (Wherein, R ¹ is a divalent organic residue derived from a diamino compound, R ² and R ³ are each independently H or a monovalent organic group, and Y ¹ and Y ² are each independently A linear or branched alkylene having 1 to 5 carbon atoms;
⁴ and R ⁵ are each independently F or a group having 1 to 1 carbon atoms.
2, Y ¹ , Y ² ,
The bonding positions of R ⁴ and R ⁵ are arbitrary positions. The monovalent organic group is a linear or branched alkyl having 1 to 20 carbon atoms, or a substituted or unsubstituted alicyclic group, aromatic group or heterocyclic group, and these groups are O or It may be bonded to N through CO, and Si
Or any of H in these groups may be halogen, OH, NH ₂ , CN, a substituted or unsubstituted alicyclic group, an aromatic group or a heterocyclic group containing N. Or when the monovalent organic group is alkyl, the non-adjacent CH ₂ in the alkyl may be substituted with O, CH = CH or C≡C. When the alkyl is bonded to N via O, O is not continuous. ) 6. A compound represented by the formula (11):
^1, characterized in that it is a group selected from the group consisting of groups represented by the formula group and the formula represented by (2) (3), the liquid crystal alignment agent varnish of claim 5. Embedded image (Wherein, R ⁶ is H or alkyl having 1 to 12 carbons, ring A is a benzene ring or cyclohexane ring, Z is a single bond,
CH ₂ , CH ₂ CH ₂ or O, r is 0 to 3, s
Is an integer of 0 to 5 and t is an integer of 0 to 3;
In the case of to 3, a plurality of Z may be the same or different from each other. Further, H on any benzene ring or cyclohexane ring may be substituted with alkyl having 1 to 4 carbon atoms. ) (Wherein X ¹ and X ² are each independently a single bond,
O, COO, OCO, NH, CONH or carbon number 1
12 is an alkylene, B ¹ and B ² each independently represent a single bond or a divalent group containing 1 to 3 rings selected from an aromatic ring and an alicyclic ring, and R ⁷ is H ,
It represents F, CN, OH or alkyl, fluoroalkyl or alkoxy having 1 to 12 carbon atoms. The position of the substituent and the position of the two free radicals on the benzene ring are arbitrary positions. ) 7. R in the structural unit represented by the formula (11)
^1, characterized in that it is a group selected from the group consisting of groups represented by the formula (2), a liquid crystal alignment agent varnish of claim 6. 8. R in the structural unit represented by the formula (11)
^1, characterized in that it is a group selected from the group consisting of groups represented by the formula (3), the liquid crystal alignment agent varnish of claim 6. 9. The method according to claim 5, wherein at least one of the monovalent organic groups according to claim 5 relates to all amide groups in the polyamide.
The liquid crystal aligning agent varnish according to any one of claims 5 to 8, wherein a ratio of the amide group substituted with is from 0.3 to 1 in a molar ratio. 10. The method according to claim 5, wherein the composition contains at least one polymer compound selected from a polyamic acid, a soluble polyimide and a polyamide not containing the structural unit represented by the formula (11). The liquid crystal aligning agent varnish according to any one of the above. 11. The concentration of the polymer compound component is 0.1 to 40.
The liquid crystal aligning agent varnish according to any one of claims 5 to 10, wherein the varnish is in a percentage by weight. 12. A liquid crystal display device comprising the liquid crystal aligning agent varnish according to claim 5.