KR102222792B1 - Novel diamine, polymer, liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element using same - Google Patents

Abstract

(식 중, A 는 열에 의해 탈리될 수 있는 유기기를 나타낸다. B 는 -CH₂-, -O-, -S- 또는 -NH- 를 나타낸다. X 는 단결합 또는 2 가의 유기기를 나타낸다. Y 는 단결합, -O-, -CONH-, -NHCO-, -OCO-, -COO-, -HN-CO-NH-, -NHCOO- 또는 -OCONH- 를 나타낸다. Z 는 단결합 또는 탄소수 1 ∼ 2 의 알킬렌기를 나타낸다. R¹ 은 수소 원자 또는 탄소수 1 ∼ 3 의 알킬기를 나타낸다. R² 는 Y 가 -CONH- 또는 -OCO- 인 경우는 -NH-A 기를 나타내고, 그 이외의 경우에는 수소 원자, 할로겐 원자 또는 탄소수 1 ∼ 5 의 알킬기를 나타낸다. k1 은 0 ∼ 3 의 정수를 나타내고, R³ 은 할로겐 원자 또는 탄소수 1 ∼ 5 의 알킬기를 나타내고, -(R³)_k1 은 치환기 R³ 이 k1 개 있는 것을 나타내고, 단, k1 이 2 이상의 경우, 2 이상의 R³ 은 각각 동일하거나 상이해도 된다. k2 는 0 ∼ 3 의 정수를 나타내고, R⁴ 는 할로겐 원자 또는 알킬기이며, -(R⁴)_k2 는 치환기 R⁴ 가 k2 개 있는 것을 나타내고, 단, k2 가 2 이상의 경우, 2 이상의 R⁴ 는 각각 동일하거나 상이해도 된다.)Diamine represented by the following formula (1).

(In the formula, A represents an organic group that can be desorbed by heat. B represents -CH ₂ -, -O-, -S- or -NH-. X represents a single bond or a divalent organic group. Y is Represents a single bond, -O-, -CONH-, -NHCO-, -OCO-, -COO-, -HN-CO-NH-, -NHCOO-, or -OCONH- Z is a single bond or 1 to 2 carbon atoms R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms R ² represents a -NH-A group when Y is -CONH- or -OCO-, and in other cases, a hydrogen atom , Represents a halogen atom or an alkyl group having 1 to 5 carbon atoms, k1 represents an integer of 0 to 3, R ³ represents a halogen atom or an alkyl group having 1 to 5 carbon atoms, and -(R ³ ) _k1 represents a substituent R ³ is k1 However, when k1 is 2 or more, two or more R ³ may be the same or different, respectively, k2 represents an integer of 0 to 3, R ⁴ represents a halogen atom or an alkyl group, -(R ⁴ ) _k2 Represents that there are k2 substituents R ⁴ , provided that when k2 is 2 or more, two or more R ⁴ may be the same or different, respectively.)

Description

New diamine, polymer, liquid crystal aligning agent, liquid crystal aligning film, and liquid crystal display device using the same {NOVEL DIAMINE, POLYMER, LIQUID CRYSTAL ALIGNMENT AGENT, LIQUID CRYSTAL ALIGNMENT FILM, AND LIQUID CRYSTAL DISPLAY ELEMENT USING SAME}

The present invention relates to a novel diamine, a polymer, a liquid crystal aligning agent used in a liquid crystal display element, a liquid crystal aligning film, and a liquid crystal display element.

In a liquid crystal display device, the liquid crystal alignment layer plays a role of aligning the liquid crystal in a certain direction. Currently, the main liquid crystal aligning film used industrially is formed by applying a polyimide liquid crystal aligning agent composed of a polyimide precursor polyamic acid (also referred to as polyamic acid) or a polyimide solution on a substrate to form a film. do. In addition, when the liquid crystal is parallel or obliquely aligned with respect to the substrate surface, after film formation, a surface stretching treatment by rubbing is further performed. In addition, as an alternative to the rubbing treatment, a method of using an anisotropic photochemical reaction by irradiation with polarized ultraviolet rays or the like has also been proposed, and in recent years, investigations toward industrialization have been conducted.

In order to improve the display characteristics of the liquid crystal display device, various changes in the structure of polyamic acid or polyimide are performed to optimize, blend resins with different characteristics, or add additives to improve liquid crystal alignment or A number of techniques have been proposed because it is possible to control the tilt angle, to improve electrical characteristics, and the like, and to further improve the display characteristics. For example, in order to obtain a high voltage retention rate, it is proposed to use a polyimide resin having a specific repeating structure (refer to Patent Document 1, etc.). In addition, for the afterimage phenomenon, by using a soluble polyimide having a nitrogen atom other than the imide group, it has been proposed to shorten the time until the afterimage is erased (refer to Patent Document 2, etc.). Further, a polyamic acid obtained from a specific diamine and tetracarboxylic dianhydride containing an oxazole or imidazole skeleton and a derivative thereof have been proposed (refer to Patent Document 3).

However, the high performance of the liquid crystal display element, the increase in the area, and the power saving of the display device have progressed, and in addition to this, it is used in various environments, and the characteristics required for the liquid crystal aligning film have also become strict. Particularly, when a liquid crystal aligning agent is applied to a substrate, printing defects due to precipitation or whitening due to a prolonged tact time, increase in ion density due to long-term use of a liquid crystal display element, or accumulated charge Problems such as exposure have become a problem, and in the conventional technology, it is becoming difficult to solve both of them at the same time.

Here, a liquid crystal aligning agent using a diamine containing an alkylamine protected by a tert-butoxycarbonyl group (hereinafter, also referred to as a Boc group) is proposed (see Patent Document 4). In this technique, a polyimide precursor having a primary or secondary aliphatic amine protected with a Boc group or a coating film of polyimide is formed, and then, when firing, a highly reactive primary or secondary aliphatic amine is produced. The crosslinking reaction between molecules proceeds to produce a polyimide film having excellent mechanical strength.

However, such a polyimide film has a problem in that the rubbing resistance is improved, but the liquid crystal orientation is conversely decreased, and RDC (residual DC voltage) is also easily accumulated.

In addition, with the recent increase in the performance of liquid crystal display devices, liquid crystal display devices have been used in applications such as large screen and high-precision liquid crystal televisions, automotive applications, for example, car navigation systems and meter panels. In such applications, in order to obtain high luminance, a backlight having a large calorific value is sometimes used. For this reason, high reliability from another viewpoint, that is, high stability against light from the backlight is required for the liquid crystal alignment film. In particular, if the voltage retention rate, which is one of the electrical characteristics, decreases due to light irradiation from the backlight, exposure failure (line exposure), which is one of the display failures of the liquid crystal display element, tends to occur, resulting in a highly reliable liquid crystal display element. You will not be able to get it. Therefore, in the liquid crystal alignment film, in addition to having good initial characteristics, for example, even after exposure to light irradiation for a long time, it is also required that the voltage retention is less likely to decrease.

Japanese Laid-Open Patent Publication No. Hei 2-287324 Japanese Laid-Open Patent Publication No. Hei 10-104633 Japanese Patent Laid-Open Publication No. 2010-54872 WO 2006-126555 publication

The present invention has been made in view of the above circumstances, is excellent in rubbing resistance and liquid crystal alignment, it is difficult to accumulate RDC (residual DC voltage), and it is possible to manufacture a liquid crystal alignment film excellent in backlight resistance and high temperature and high humidity resistance. It aims at providing the diamine which can obtain a liquid crystal aligning agent excellent in printability (solubility in a solvent of a polymer). That is, it aims at providing the diamine which can obtain polyamide, polyamic acid, polyamic acid ester, and polyimide which have these characteristics, and to provide a liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element using the same.

As a result of intensive research, the present inventors found that polyamide, polyamic acid, polyamic acid ester, and liquid crystal aligning agent containing polyimide using a specific diamine represented by the following formula (1) as the diamine component were very Having found out what is effective, the present invention has been completed. In addition, the diamine represented by formula (1) is a novel compound which is not documented.

That is, the present invention has the following summary.

1. Diamine characterized by represented by the following formula (1).

[Formula 1]

(In the formula, A represents an organic group that can be desorbed by heat. B represents -CH ₂ -, -O-, -S- or -NH-. X represents a single bond or a divalent organic group. Y is Represents a single bond, -O-, -CONH-, -NHCO-, -OCO-, -COO-, -HN-CO-NH-, -NHCOO-, or -OCONH- Z is a single bond or 1 to 2 carbon atoms R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms R ² represents a -NH-A group when Y is -CONH- or -OCO-, and in other cases, a hydrogen atom , Represents a halogen atom or an alkyl group having 1 to 5 carbon atoms, k1 represents an integer of 0 to 3, R ³ represents a halogen atom or an alkyl group having 1 to 5 carbon atoms, and -(R ³ ) _k1 represents a substituent R ³ is k1 However, when k1 is 2 or more, two or more R ³ may be the same or different, respectively, k2 represents an integer of 0 to 3, R ⁴ represents a halogen atom or an alkyl group, -(R ⁴ ) _k2 Represents that there are k2 substituents R ⁴ , provided that when k2 is 2 or more, two or more R ⁴ may be the same or different, respectively.)

2. The diamine according to 1., wherein A is a tert-butoxycarbonyl group.

3. The diamine according to 1. or 2. wherein B is -NH-.

4. X represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, an unsaturated hydrocarbon group, an aromatic hydrocarbon group or a heterocycle, and Y represents a single bond, -O-, -OCO- or -COO- The diamine according to any one of 1. to 3. characterized.

5. X represents a divalent C1-C20 saturated hydrocarbon group, an unsaturated hydrocarbon group, an aromatic hydrocarbon group or a heterocycle, Y represents -CONH- (however, C=O is bonded to X), and R ^The diamine according to any one of 1. to 3. wherein divalent is an -NH-A group.

6. By imidizing polyamide, polyamic acid, polyamic acid ester, or the polyamic acid and/or polyamic acid ester obtained by using the diamine component containing the diamine represented by formula (1) described in 1. to 5. A polymer comprising the obtained polyimide.

7. The polymer according to 6., wherein the diamine component contains 5 to 100 mol% of the diamine represented by formula (1).

8. The polymer according to 6. or 7. wherein the diamine component contains 5 to 50 mol% of a diamine represented by the following formula (2).

[Formula 2]

(In the formula, P ¹ is a single bond, -O-, -CH ₂ O-, -CONH-, -NHCO-, -OCO-, -COO-, -HN-CO-NH-, -NHCOO- or OCONH- , Q ¹ , Q ² , Q ³ each independently represent a divalent benzene ring or a cyclohexane ring, p, q, and r each independently represent an integer of 0 or 1, and P ² is a hydrogen atom, carbon number It represents an alkyl group of 1 to 22 or a divalent organic group having 12 to 25 carbon atoms having a steroid skeleton.)

A liquid crystal aligning agent containing the polymer according to any one of 9. 6. to 8.

A liquid crystal aligning film characterized by using the liquid crystal aligning agent of 10. 9.

11. A liquid crystal display device comprising the liquid crystal alignment film described in 10.

Since the liquid crystal aligning agent of this invention contains a polymer using the diamine of the specific structure represented by said Formula (1), printability is favorable. In addition, the liquid crystal aligning film obtained from the liquid crystal aligning agent of the present invention reacts with the amino group from which the protecting group derived from the diamine of the specific structure represented by the formula (1) is removed at the time of firing the coating film to form a cyclized structure. As a result, it is excellent in rubbing resistance and has good liquid crystal orientation, and RDC is difficult to accumulate, and a decrease in voltage retention is unlikely to occur even in a high-temperature, high-humidity environment over a long period of time, or under light irradiation conditions such as a backlight. Therefore, a liquid crystal display device having such a liquid crystal alignment film is excellent in reliability.

Hereinafter, the present invention will be described in detail.

<Diamine represented by formula (1)>

The diamine of this invention is a diamine represented by said formula (1). The organic group A that can be desorbed by heat in the formula (1) is not particularly limited as long as it is an organic group in which -NHA is converted into an amino group by decomposing and desorbing by heat. Of course, in the state where A is provided, the reactivity of the amino group is reduced. As the structure of A, which is an organic group that can be desorbed by heat, a carbamate type represented by a benzyloxycarbonyl group, a 9-fluorenylmethyloxycarbonyl group, an allyloxycarbonyl group, a tertiary butoxycarbonyl group (tert-butoxycarbonyl group), etc. Although an organic group of is mentioned, a tertiary butoxycarbonyl group is particularly preferable from the viewpoint of good efficiency of desorption by heat, desorption at a relatively low temperature, and discharge as a harmless gas when desorbed. In addition, in this specification, an organic group is a hydrocarbon group which may have N or O, for example.

A more preferable specific structure of the diamine represented by formula (1) is shown in the following formula (3) and the following formula (4).

[Formula 3]

In formula (3), D represents a divalent C1-C20 saturated hydrocarbon group, an unsaturated hydrocarbon group, an aromatic hydrocarbon group, or a heterocycle, and D may have various substituents. In addition, E is a single bond, or a divalent C1-C20 saturated hydrocarbon group, an unsaturated hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic ring, and F is a single bond or an ether bond (-O-), an ester bond (-OCO -, -COO-). m is 1 or 0.

The hydrogen atom of the benzene ring having an amino group in the above formula (3) may be substituted with an organic group, specifically, for example, R ³ or R ⁴ in the formula (1). Although selected, it is preferable that it is unsubstituted. In addition, the position of substitution of the amino group is not particularly limited, but from the viewpoint of the difficulty of synthesis and availability of reagents, the position of meta or para is preferable based on the amide bond, and the position of para is particularly preferable from the viewpoint of liquid crystal orientation. . Also in the aminobenzene not having a protected amino group (i.e. -NHA), the meta or para position is preferred, and the meta position is preferred from the viewpoint of solubility, and the liquid crystal orientation is similarly based on the amide bond. From a viewpoint, the position of para is preferable.

In addition, D in the formula (3) is not limited, and various structures can be selected depending on structures such as dicarboxylic acid and tetracarboxylic dianhydride used as a raw material for diamine represented by formula (3). As D, a divalent hydrocarbon group or the like is preferable from the viewpoint of solubility, and preferable examples thereof include a linear alkylene group and a cyclic alkylene group, and this hydrocarbon group may have an unsaturated bond. Moreover, from the viewpoint of liquid crystal orientation and electrical properties, a divalent aromatic hydrocarbon group or a heterocyclic ring is preferable. From the viewpoint of liquid crystal orientation, it is preferable that D does not have a substituent, but from the viewpoint of solubility, it is preferable that a hydrogen atom is substituted with a carboxylic acid group or a fluorine atom.

The diamine represented by formula (3) and the diamine represented by formula (4) when m is 0 are diamines having an asymmetric structure, but preferred D is the same as above, and preferred E is also the same as preferred D described above. Moreover, regarding the diamine represented by Formula (4), a compound in which both E and F are single bonds is also preferable.

The diamine represented by formula (1) of the present invention is characterized by containing an aromatic amino group protected by an organic group A capable of being desorbed by heat such as a tertiary butoxycarbonyl group (hereinafter also referred to as a Boc group). Usually, since the amino group is a reactive organic group, it is difficult to apply it as a part of the side chain of the diamine as it is, but by protecting an organic group that can be desorbed by heat such as a Boc group, the reactivity of the amino group can be reduced. In addition, if the amino group protected by the organic group A that can be desorbed by heat such as Boc group is heated above about 150°C, the organic group A that can be desorbed by heat such as Boc group is deprotected and can be changed to an amino group. . In addition, the side chain of a diamine is a structure branched from the structure which connects two amino groups of a diamine. In addition to it, since the Boc group has a bulky tertiary butyl group, the solubility of the monomer (diamine represented by formula (1)) can be improved, and in addition, produced by using the monomer (diamine represented by formula (1)) The polymer can also improve solubility in the same way. Therefore, the liquid crystal aligning agent containing the polymer (polyamic acid, polyamic acid ester, polyimide) obtained using this monomer (diamine represented by formula (1)) is good in printability.

In addition, in the case of using the diamine described in Patent Document 3, since the solubility of the obtained polymer is remarkably low compared to the polymer obtained using the diamine represented by the formula (1) of the present invention, γ- used as a liquid crystal aligning agent Polyimide (solvent-soluble polyimide) or polyamide soluble in a solvent such as butyrolactone could not be obtained.

The amino group is a highly reactive organic group and is known to react with various sites such as unsaturated bonds, carboxylic acids, carboxylic anhydrides, epoxy compounds, and carbonyls. On the other hand, as shown in the figure below, if an amino group protected by an organic group A that can be desorbed by heat is placed so as to be close to a linking group containing a carbonyl group such as an amide bond or an ester bond, the reaction is not intermolecular, but within the molecule. It becomes more likely to occur, and can be induced with, for example, benzoimidazole [scheme-1]. The diamine of the present invention aims to form a heterocycle by reacting an amino group generated by firing in a molecule.

[Formula 4]

In addition, it is thought that not all of the amino groups from which the organic group A, which can be desorbed by heat, has fallen, are consumed in the cyclization reaction, and some of them are also consumed in the intermolecular reaction (i.e., crosslinking reaction). It is thought that it contributes to the improvement of reliability by crosslinking with a component. Based on this, the liquid crystal aligning film obtained from polyamic acid, polyamic acid ester, polyimide or polyamide using the diamine represented by the formula (1) of the present invention is less likely to be filmed during the rubbing treatment, and thus has excellent rubbing resistance, and for a long period of time. It has been demonstrated by this study that even if exposed to high temperature and high humidity, the voltage retention rate is less likely to decrease even when exposed to the backlight.

In addition, since the bulky Boc group is inferior at a relatively low temperature, the liquid crystal alignment property also changes to a good structure, so that both rubbing resistance and liquid crystal alignment property can be achieved.

In addition, since the structure such as benzimidazole produced by firing obtains aromaticity, it becomes an electrochemically active structure, thus contributing to lowering RDC and making it possible to obtain a liquid crystal alignment film in which RDC is difficult to accumulate. Particularly, if both the aromatic tetracarboxylic dianhydride and the diamine represented by the formula (1) of the present invention are used as raw materials, it is considered that they strongly interact with each other, and a liquid crystal alignment film in which RDC is very hard to accumulate can be obtained.

<Synthesis of diamine represented by formula (1)>

Hereinafter, the main synthesis method of the diamine represented by the formula (1) of the present invention will be described. Incidentally, the method described below is a synthesis example, and is not limited thereto.

Formula (1) diamine of the present invention synthesizes a dinitro form or a mononitro form with a protecting group that can be removed in the reduction step through each step described below, and converts the nitro group to an amino group in a commonly used reduction reaction. It can be obtained by doing.

The method for synthesizing dinitro or mononitro, which is a precursor of the diamine represented by formula (1), is not particularly limited, but for example, heat such as tertiary butyl bicarbonate to a diaminobenzene derivative adjacent to two amino groups. And a method of reacting a protective reagent capable of deprotection. For example, in 4-nitro-o-phenylenediamine, the method represented by the following reaction formula is mentioned.

[Formula 5]

In the above reaction, if necessary, it can be carried out in the presence of a base. The base used is not particularly limited as long as it can be synthesized, but inorganic bases such as potassium carbonate, sodium carbonate, cesium carbonate, sodium alkoxide, potassium alkoxide, sodium hydroxide, potassium hydroxide and sodium hydride, pyridine, dimethylaminopyridine, trimethylamine And organic bases such as triethylamine and tributylamine. On the other hand, depending on the base to be used, since two protecting groups may be substituted with one amino group, it is necessary to appropriately select a base. A base such as sodium hydride is preferred because it can efficiently extract hydrogen from the amino group, but since it can be synthesized other than this method, the synthesis method is not particularly limited.

After obtaining the protected diaminobenzene derivative represented by the above reaction formula, this protection against 1 equivalent of dicarboxylic acid halide or tetracarboxylic dianhydride derived using thionyl chloride or oxalyl chloride, etc. By reacting the resulting diaminobenzene derivative in an amount of 2 equivalents, the precursor (dinitro form) of the diamine represented by the above formula (3) can be synthesized. Further, by reacting a dicarboxylic acid, a condensing agent, and a base with a protected diaminobenzene derivative, a precursor (dinitro form) of a diamine represented by the above formula (3) can be synthesized. As the dicarboxylic acid, tetracarboxylic dianhydride and the like that can be used in these reactions, those exemplified by polyamide, polyamic acid, polyamic acid ester, and polyimide described later can be used as they are.

[Formula 6]

(In the formula, D is the same as D in the formula (3), and D'is a tetravalent group in which two hydrogen atoms have been removed from D.)

In addition, the compound in which m is 0 in the formula (3) or the compound represented by the formula (4) contains 1 equivalent or less of the diaminobenzene derivative protected by the above method to obtain a monocarboxylic acid or dicarboxylic anhydride. Thereafter, it can be obtained by reacting a mononitrobenzene derivative having a group capable of reacting with a carboxylic acid. Alternatively, it can be obtained by reacting a nitrobenzene-containing carboxylic acid or dicarboxylic anhydride with a protected diaminobenzene derivative, but various synthesis methods can be selected depending on the type of compound to be obtained.

The method of reducing the dinitro compound, which is a precursor of the diamine represented by the formula (1) of the present invention, is not particularly limited, and usually, palladium-carbon, platinum oxide, Raney nickel, platinum black, rhodium-alumina, platinum carbon sulfide, etc. As a catalyst, there is a method of performing reduction with hydrogen gas, hydrazine, hydrogen chloride, or the like in a solvent such as ethyl acetate, toluene, tetrahydrofuran, dioxane, and alcohol. If necessary, an autoclave or the like may be used. On the other hand, when an unsaturated bond site is included in the structure, the use of palladium carbon or platinum carbon may reduce the unsaturated bond site and become a saturated bond. Therefore, preferred conditions include reduced iron, tin, and tin chloride. Reduction conditions using a transition metal as a catalyst are preferred.

Further, the diamine represented by the formula (1) of the present invention can be obtained by deprotecting in the reduction step in the same manner from a diaminobenzene derivative protected with a benzyl group or the like.

<Polymer obtained using diamine represented by formula (1)>

In the polyamide of the present invention, a diamine component containing a diamine represented by formula (1) and a dicarboxylic acid halide are reacted in the presence of a base, or a dicarboxylic acid and a diamine component are reacted in the presence of a suitable condensing agent or base. It is a polyamide obtained by Moreover, the polyamic acid of this invention is a polyamic acid obtained by reaction of a diamine component containing a diamine represented by Formula (1) and tetracarboxylic dianhydride. In the polyamic acid ester of the present invention, a diamine component containing a diamine represented by formula (1) and a tetracarboxylic acid diester dichloride are reacted in the presence of a base, or a tetracarboxylic acid diester and a diamine component are combined with a suitable condensing agent or a base. It is a polyamic acid ester obtained by reacting in the presence of. In addition, polyamic acid ester is also obtained by the method of converting the carboxyl group of polyamic acid into ester. The polyimide of the present invention is a polyimide obtained by subjecting this polyamic acid to dehydration ring closure (imidization), or by heating a polyamic acid ester to ring closure (imidation). These polyamides, polyamic acids, polyamic acid esters, and polyimides are all useful as polymers for obtaining a liquid crystal aligning film. In addition, the diamine represented by formula (1) contained in the diamine component may be one or two or more, and the diamine component contains one or two or more diamines other than the diamine represented by formula (1). You may have it. The diamine represented by the above formula (1) is preferably 5 to 100 mol%, and more preferably 20 to 100 mol% with respect to the total amount of the diamine component. In addition, in the present specification, unless otherwise specified, the ratio is based on the number of moles.

As other diamines other than the diamine represented by formula (1) which may be contained in the diamine component, the diamine represented by the above formula (2) can be mentioned. The diamine represented by the above formula (2) contributes to increasing the pretilt angle of the liquid crystal, and as these diamines, a long-chain alkyl group, a perfluoroalkyl group, an aromatic cyclic group, an aliphatic cyclic group, or a combination of these diamines , It is preferably a diamine having a steroid skeleton group or the like.

The preferred size of the pretilt angle varies depending on the mode, but a preferred pretilt angle can be obtained by selecting various structures and amounts of the diamine introduced.

In the diamine represented by formula (2), in the TN mode requiring a relatively low pretilt angle of 3 to 5° or the OCB mode requiring a pretilt of 8 to 20°, the side chain having a relatively low tilt expression ( Diamines having -P ¹ -(Q ¹ ) _p -(Q ² ) _q -(Q ³ ) _r -P ² ) are preferred.

As a structure having a relatively small tilt expression ability, P ¹ is preferably -O-, -NHCO-, or -CONH-, in the formula, p is 0 to 1, q is 0 to 1, r is preferably 0, and p And/or when q is 1, P ² is preferably a linear alkyl having 1 to 12 carbon atoms, and when p = q = r = 0, P ² has a linear alkyl group having 10 to 22 carbons or a steroid skeleton. A divalent organic group selected from organic groups having 12 to 25 carbon atoms is preferable. Although the specific structure of the side chain diamine with small tilt expression ability is shown in Table 1, it is not limited to this.

[Table 1]

From the viewpoint of electrical properties, long-chain alkyl side chains such as [2-1] to [2-3] in Table 1 are preferable, and [2-25] to Table 1 from the viewpoint of stability of liquid crystal orientation and pretilt. The diamine represented by [2-27] is preferable.

On the other hand, in the VA mode (vertical alignment method, Vertical Alignment) or the like, vertical alignment can be obtained by using a side chain having a high tilt expression capability. As a preferable structure of formula (2) in VA mode, in the formula, P ¹ is preferably -O-, -COO-, or -CH ₂ O-, p is 0 to 1, q is 0 to 1, r is preferably 0 to 1, and P ² is preferably 2 to 22. When p = q = r = 0, P ² is preferably a C 18 to C 22 linear alkyl group or a divalent organic group which is a C 12 to C 25 organic group having a steroid skeleton. The specific structures of the side chain diamine having a high tilt expression ability are shown in Tables 2-1 and 2-2.

[Table 2-1]

[Table 2-2]

These diamines have high tilt expression ability, and are preferable when used in VA mode. In particular, diamines such as [2-43] and [2-92] are preferable because they have high tilt expression ability and exhibit vertical orientation with a relatively small amount of side chains. In particular, diamines of [2-52] or [2-101] Is preferable from the viewpoint of printability of a liquid crystal aligning agent because it has a very high tilt expression ability and can obtain a vertical alignment with a very small amount of side chains.

On the other hand, in the diamine represented by formula (2), P ¹ is preferably -NHCO-, and P ² is preferably an alkyl group having 1 to 16 carbon atoms, preferably 3 to 10 carbon atoms. In addition, Q ¹ , Q ² , Q ³ and p, q, r are selected from an appropriate combination. In the structure of such a diamine, the position of each substituent on the benzene ring is not particularly limited, but the positional relationship between the two amino groups is preferably meta or para.

As an example of the diamine represented by the said formula (2), the diamine represented by the following formula (5) is mentioned.

[Formula 7]

(In formula (5), n1 is an integer of 0-21, Preferably it is an integer of 0-15.)

Although a preferable specific example of the diamine represented by said formula (5) is given, it is not limited to this.

[Formula 8]

Here, n2 is an integer of 0-19. When n2 is small, the pretilt angle is not expressed, and when it is large, the vertical alignment property is easily expressed, but the coating property of the liquid crystal aligning agent is deteriorated. Therefore, the preferable range of n2 is 2 to 15, more preferably 4 to 10.

The content of the diamine represented by the above formula (2) is preferably 5 to 50 mol% with respect to the total amount of the diamine component, and particularly preferably 5 to 30 mol% from the viewpoint of pretilt uniformity and printability. Moreover, it is preferable to contain 0.1-1.2 mol with respect to 1 mol of the diamine represented by formula (1), and, as for the diamine represented by formula (2), it is more preferably 0.3-1.0 mol. When the diamine of formula (2) is in this range, an appropriate pretilt angle is obtained, and more favorable liquid crystal orientation is obtained.

As other diamines other than the diamine represented by formula (1), which may be contained in the diamine component, the following diamines may be mentioned in addition to the diamine represented by formula (2).

Examples of alicyclic diamines include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, 4,4'-diamino-3,3'- Dimethyldicyclohexylamine, isophoronediamine, and the like.

Examples of aromatic diamines include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, 3,5-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'- Diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminobenzophenone, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-amino Phenoxy)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]hexafluoropropane, 2,2-bis[4-(4-amino Phenoxy)phenyl]propane, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy)phenyl]sulfone, 1,1-bis(4-aminophenyl)cyclohexane , α,α'-bis(4-aminophenyl)-1,4-diisopropylbenzene, 9,9-bis(4-aminophenyl)fluorene, 2,2-bis(3-aminophenyl)hexafluoro Lopropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 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-bi S(4-aminophenyl)pentane, 1,6-bis(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-dio 8, di(4-aminophenyl)butane-1,4-dioate, 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 Si]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-(4-aminophenoxy)phenoxy]octane, 1,9-bis[4-(4-aminophenoxy)phenoxy Cy]nonane, 1,10-bis[4-(4-aminophenoxy)phenoxy]decane, and the like.

Examples of the aromatic-aliphatic diamine include 3-aminobenzylamine, 4-aminobenzylamine, 3-amino-N-methylbenzylamine, 4-amino-N-methylbenzylamine, 3-aminophenethylamine, and 4-aminophen Netylamine, 3-amino-N-methylphenethylamine, 4-amino-N-methylphenethylamine, 3-(3-aminopropyl)aniline, 4-(3-aminopropyl)aniline, 3-(3- Methylaminopropyl)aniline, 4-(3-methylaminopropyl)aniline, 3-(4-aminobutyl)aniline, 4-(4-aminobutyl)aniline, 3-(4-methylaminobutyl)aniline, 4- (4-methylaminobutyl)aniline, 3-(5-aminopentyl)aniline, 4-(5-aminopentyl)aniline, 3-(5-methylaminopentyl)aniline, 4-(5-methylaminopentyl)aniline , 2-(6-aminonaphthyl)methylamine, 3-(6-aminonaphthyl)methylamine, 2-(6-aminonaphthyl)ethylamine, 3-(6-aminonaphthyl)ethylamine, etc. Can be lifted.

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-oxadia Sol, etc. are mentioned.

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, 1,18-diaminooctadecane, 1,2-bis(3-aminopropoxy)ethane, and the like.

Further, the diamine component may contain, in the side chain, a diamine having an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a heterocycle, and a large cyclic substituent composed of them. Specifically, the diamine represented by the following formula [DA-1]-formula [DA-30] can be illustrated.

[Formula 9]

(In formulas [DA-1] to [DA-5], R ₆ is an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group.)

[Formula 10]

(In formulas [DA-6] to [DA-9], S ₅ is -COO-, -OCO-, -CONH-, -NHCO-, -CH ₂ -, -O-, -CO-, or- Represents NH-, and R ₆ represents a C1-C22 alkyl group or a fluorine-containing alkyl group.)

[Formula 11]

(In formulas [DA-10] and [DA-11], S ₆ represents -O-, -OCH ₂ -, -CH ₂ O-, -COOCH ₂ -, or -CH ₂ OCO-, and R ₇ Is a C1-C22 alkyl group, an alkoxy group, a fluorine-containing alkyl group, or a fluorine-containing alkoxy group.)

[Formula 12]

(In formulas [DA-12] to [DA-14], S ₇ is -COO-, -OCO-, -CONH-, -NHCO-, -COOCH ₂ -, -CH ₂ OCO-, -CH ₂ O -, -OCH ₂ -, or -CH ₂ -, and R ₈ is an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group, or a fluorine-containing alkoxy group.)

[Formula 13]

(In formulas [DA-15] and [DA-16], S ₈ is -COO-, -OCO-, -CONH-, -NHCO-, -COOCH ₂ -, -CH ₂ OCO-, -CH ₂ O -, -OCH ₂ -, -CH ₂ -, -O-, or -NH-, and R ₉ is a fluorine group, cyano group, trifluoromethane group, nitro group, azo group, formyl group, acetyl group, ace It is a oxy group or a hydroxyl group.)

[Formula 14]

(In formulas [DA-17] to [DA-20], R ₁₀ is an alkyl group having 3 to 12 carbon atoms, and the cis-trans isomers of 1,4-cyclohexylene are respectively trans forms.)

[Formula 15]

[Formula 16]

In the case of performing orientation treatment by light, a more stable pretilt can be obtained by using a diamine represented by General Formula (1) and a diamine of [DA-1] to [DA-26] together, so it is preferable. As more preferable diamine which can be used together, formulas [DA-10]-[DA-26] are preferable, More preferably, they are diamines of [DA-10]-[DA-16]. Although the preferable content of these diamines is not particularly limited, 5 to 50 mol% is preferable with respect to the total amount of the diamine component, and 5 to 30 mol% is preferable from the viewpoint of printability.

Moreover, the diamine component may contain the following diamine.

[Formula 17]

In formula [DA-35], m is an integer of 0 to 3, and in formula [DA-38], n is an integer of 1 to 5. By introducing [DA-31] or [DA-32], VHR (voltage retention) can be further improved, and [DA-33] to [DA-38] are more effective in reducing the accumulated charge. , desirable.

In addition, the diamine component may contain diaminosiloxane etc. represented by the following formula [DA-39].

[Formula 18]

(In formula [DA-39], m is an integer of 1-10.)

Other diamines may be used singly or in combination of two or more depending on characteristics such as liquid crystal alignment, voltage retention characteristics, and accumulated charge when used as a liquid crystal alignment film.

In order to obtain the polyamic acid of the present invention, the diamine component and the tetracarboxylic dianhydride reacted are not particularly limited. The specific example is given below.

As tetracarboxylic dianhydride 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-cyclobutane tetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutane Tetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,2,4,5- Cyclohexanetetracarboxylic dianhydride, 3,4-dicarboxy-1-cyclohexylsuccinic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic dianhydride, 1 ,2,3,4-butanetetracarboxylic dianhydride, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic dianhydride, 3,3',4,4'-dish Chlohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracar Acid dianhydride, tricyclo[4.2.1.0 ^2,5 ]nonane-3,4,7,8-tetracarboxylic acid-3,4:7,8-2 anhydride, hexacyclo[6.6.0.1 ^2,7 .0 ^3,6 .1 ^9,14 . 0 ^10,13] hexadecane -4,5,11,12- tetracarboxylic acid 4,5: 11,12-2 anhydride, 4- (2,5-dioxo-tetrahydrofuran-3-yl) - 1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride, etc. are mentioned.

Furthermore, when aromatic tetracarboxylic dianhydride is used in addition to the above alicyclic structure or aliphatic structure-containing tetracarboxylic dianhydride, the liquid crystal orientation is further improved and the accumulated charge of the liquid crystal cell can be reduced. desirable. As aromatic tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic acid Dianhydride, 2,3,3',4-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,3,3',4-benzo Phenonetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid 2 Anhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, etc. are mentioned.

In order to obtain the polyamic acid ester of the present invention, the diamine component and the tetracarboxylic acid diester to be reacted are not particularly limited. The specific example is given below.

Specific examples of aliphatic tetracarboxylic acid diester include 1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1 ,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dialkyl ester, 1,2,3,4-cyclopentanetetracarboxylic acid dialkyl ester, 2,3,4,5-tetrahydrofuran tetracarboxylic acid dialkyl ester, 1,2,4,5-cyclohexanetetracarboxylic acid dialkyl Ester, 3,4-dicarboxy-1-cyclohexylsuccinic acid dialkyl ester, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid dialkyl ester, 1,2,3, 4-butanetetracarboxylic acid dialkyl ester, bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic acid dialkyl ester, 3,3',4,4'-dicyclohexyltetra Carboxylic acid dialkyl ester, 2,3,5-tricarboxycyclopentyl acetate dialkyl ester, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic acid di Alkyl ester, tricyclo[4.2.1.0 ^2,5 ]nonane-3,4,7,8-tetracarboxylic acid-3,4:7,8-dialkyl ester, hexacyclo[6.6.0.1 ^2,7 . 0 ^3,6 .1 ^9,14 .0 ^10,13] hexadecane -4,5,11,12- tetracarboxylic acid 4,5: 11,12- di-alkyl ester, 4- (2,5 Dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic dialkyl ester, etc. are mentioned.

As aromatic tetracarboxylic acid diester, pyromellitic acid dialkyl ester, 3,3',4,4'-biphenyltetracarboxylic acid dialkyl ester, 2,2',3,3'-biphenyltetracarboxylic acid di Alkyl ester, 2,3,3',4-biphenyltetracarboxylic acid dialkyl ester, 3,3',4,4'-benzophenonetetracarboxylic acid dialkyl ester, 2,3,3',4-benzo Phenone tetracarboxylic acid dialkyl ester, bis (3,4-dicarboxyphenyl) ether dialkyl ester, bis (3,4-dicarboxyphenyl) sulfone dialkyl ester, 1,2,5,6-naphthalene tetracarboxyl An acid dialkyl ester, a 2,3,6,7-naphthalene tetracarboxylic acid dialkyl ester, etc. are mentioned.

In order to obtain the polyamide of the present invention, the diamine component and the dicarboxylic acid to be reacted are not particularly limited. As specific examples of aliphatic dicarboxylic acids of dicarboxylic acids or derivatives thereof, malonic acid, oxalic acid, dimethylmalonic acid, succinic acid, fumaric acid, glutaric acid, adipic acid, muconic acid, 2-methyladipic acid, trimethyl And dicarboxylic acids such as adipic acid, pimelic acid, 2,2-dimethylglutaric acid, 3,3-diethylsuccinic acid, azelaic acid, sebacic acid, and suberic acid.

As alicyclic dicarboxylic acid, 1,1-cyclopropanedicarboxylic acid, 1,2-cyclopropanedicarboxylic acid, 1,1-cyclobutanedicarboxylic acid, 1,2-cyclobutanedicarboxylic acid Acid, 1,3-cyclobutanedicarboxylic acid, 3,4-diphenyl-1,2-cyclobutanedicarboxylic acid, 2,4-diphenyl-1,3-cyclobutanedicarboxylic acid, 1-cyclobutene-1,2-dicarboxylic acid, 1-cyclobutene-3,4-dicarboxylic acid, 1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,1-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexane Dicarboxylic acid, 1,4-(2-norbornene)dicarboxylic acid, norbornene-2,3-dicarboxylic acid, bicyclo[2.2.2]octane-1,4-dicarboxyl Acid, bicyclo[2.2.2]octane-2,3-dicarboxylic acid, 2,5-dioxo-1,4-bicyclo[2.2.2]octanedicarboxylic acid, 1,3-adaman Tanedicarboxylic acid, 4,8-dioxo-1,3-adamantanedicarboxylic acid, 2,6-spiro[3.3]heptanedicarboxylic acid, 1,3-adamantane 2 acetic acid, campha And mountains.

As aromatic dicarboxylic acid, o-phthalic acid, isophthalic acid, terephthalic acid, 5-methylisophthalic acid, 5-tert-butylisophthalic acid, 5-aminoisophthalic acid, 5-hydroxyisophthalic acid, 2,5-dimethyl terephthalic acid, Tetramethylterephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-anthracendica Carboxylic acid, 1,4-anthraquinonedicarboxylic acid, 2,5-biphenyldicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 1,5-biphenylenedicarboxylic acid, 4,4''-terphenyldicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,4'-diphenylethanedicarboxylic acid, 4,4'-diphenylpropanedicarboxyl Acid, 2,2-diphenylhexafluoropropane-4,4'-dicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-bibenzyldicarboxylic acid, 4, 4'-Stylbendicarboxylic acid, 4,4'-trandicarboxylic acid, 4,4'-carbonyl 2 benzoic acid, 4,4'-diphenylsulfonedicarboxylic acid, 4,4'-di Phenylsulfidedicarboxylic acid, p-phenylene 2 acetic acid, 3,3'-p-phenylenedipropionic acid, 4-carboxylic acid, p-phenylenediacrylic acid, 3,3'-[4,4'-(methylene Di-p-phenylene)]dipropionic acid, 4,4'-[4,4'-(oxydi-p-phenylene)]dipropionic acid, 4,4'-[4,4'-(oxydi- p-phenylene)] 2 butyric acid, (isopropylidenedi-p-phenylenedioxy) 2 butyric acid, and dicarboxylic acids such as bis(p-carboxyphenyl)dimethylsilane.

Examples of the dicarboxylic acid containing a heterocycle include 1,5-(9-oxofluorene)dicarboxylic acid, 3,4-furandicarboxylic acid, 4,5-thiazoledicarboxylic acid, and 2- Phenyl-4,5-thiazoledicarboxylic acid, 1,2,5-thiadiazole-3,4-dicarboxylic acid, 1,2,5-oxadiazole-3,4-dicarboxylic acid , 2,3-pyridinedicarboxylic acid, 2,4-pyridinedicarboxylic acid, 2,5-pyridinedicarboxylic acid, 2,6-pyridinedicarboxylic acid, 3,4-pyridinedicarboxylic acid And 3,5-pyridine dicarboxylic acid.

The various dicarboxylic acids described above may have an acid dihalide or an anhydrous structure. These dicarboxylic acids are particularly preferably dicarboxylic acids capable of imparting a polyamide having a linear structure in order to maintain the orientation of the liquid crystal molecules. Among these, terephthalic acid, isoterephthalic acid, 1,4-cyclohexanedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,4'-di Phenylethanedicarboxylic acid, 4,4'-diphenylpropanedicarboxylic acid, 4,4'-diphenylhexafluoropropanedicarboxylic acid, 2,2-bis(phenyl)propanedicarboxylic acid, 4,4-terphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,5-pyridinedicarboxylic acid, or acid dihalides thereof, and the like are preferably used. Although isomers exist in some of these compounds, a mixture containing them may be sufficient. Moreover, you may use 2 or more types of compounds together. In addition, the dicarboxylic acids used in the present invention are not limited to the above exemplary compounds.

These tetracarboxylic dianhydrides, tetracarboxylic acid diesters, tetracarboxylic acid diester dichlorides, dicarboxylic acids and dicarboxylic acid halides, etc. are used as liquid crystal alignment properties, voltage retention characteristics, and accumulated charge when used as a liquid crystal alignment film. Depending on the characteristics, such as, one type or two or more types can be used in combination, respectively.

In obtaining the polyamic acid of the present invention by reaction of a tetracarboxylic dianhydride and a diamine component, a known synthesis method can be used. In general, it is a method of reacting a tetracarboxylic dianhydride and a diamine component in an organic solvent. The reaction of the tetracarboxylic dianhydride and the diamine component is advantageous in that it proceeds relatively easily in an organic solvent and no by-products are generated.

The organic solvent used for the reaction of the tetracarboxylic dianhydride and the diamine component is not particularly limited as long as the resulting polyamic acid is dissolved. The specific example is given below.

N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, Pyridine, dimethyl sulfone, γ-butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cello Solve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol , Propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl Ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl Acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclo Hexene, propyl ether, dihexyl ether, dioxane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, N-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxy Propionic acid, 3-methoxypropionic acid propyl, 3-methoxypropionate butyl, diglyme, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy -N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, and the like. have. These may be used individually or may be mixed and used. Moreover, even if it is a solvent which does not dissolve the polyamic acid, you may use it by mixing with the said solvent in the range in which the produced|generated polyamic acid does not precipitate.

Moreover, since moisture in an organic solvent inhibits a polymerization reaction and furthermore causes hydrolysis of the produced polyamic acid, it is preferable to use a dehydration-dried organic solvent as much as possible.

When reacting tetracarboxylic dianhydride and diamine component in an organic solvent, a solution in which the 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. And, on the contrary, a method of adding a diamine component to a solution in which tetracarboxylic dianhydride is dispersed or dissolved in an organic solvent, and a method of alternately adding tetracarboxylic dianhydride and diamine component. Either method may be used. In addition, when the tetracarboxylic dianhydride or diamine component is made of a plurality of compounds, the reaction may be carried out in a premixed state, or may be individually sequentially reacted, or the individually reacted low molecular weight compounds are mixed and reacted to produce a high molecular weight compound. You may do it.

The polymerization temperature in that case can be selected from -20°C to 150°C, but is preferably in the range of -5°C to 100°C. In addition, the reaction can be carried out at any concentration, but if the concentration is too low, it becomes difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution becomes too high and uniform stirring becomes difficult. The total concentration in the reaction solution of the acid dianhydride and the diamine component is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The initial reaction is carried out at a high concentration, and after that, an organic solvent can be added.

In the polymerization reaction of the polyamic acid, the ratio of the total number of moles of the tetracarboxylic dianhydride and the total number of moles of the diamine component is preferably from 0.8 to 1.2. As in a typical polycondensation reaction, the closer this molar ratio is to 1.0, the greater the molecular weight of the resulting polyamic acid.

The polyimide of the present invention can be obtained by dehydrating and cyclizing the polyamic acid. In the polyimide of the present invention, the dehydration cyclization rate (imidation rate) of the amic acid group does not necessarily need to be 100%, and can be arbitrarily adjusted in the range of 0% to 100% according to the use or purpose.

As a method of imidizing the polyamic acid, thermal imidation in which the solution of polyamic acid is heated as it is, and catalytic imidization in which a catalyst is added to the solution of polyamic acid are exemplified.

When the polyamic acid is thermally imidized in a solution, the temperature is 100°C to 400°C, preferably 120°C to 250°C, and it is preferable to carry out while removing water generated by the imidation reaction out of the system.

The catalytic imidization of the polyamic acid can be carried out by adding a basic catalyst and an acid anhydride to a solution of the polyamic acid and stirring at -20 to 250°C, preferably 0 to 180°C. The amount of the basic catalyst is 0.5 to 30 mole times, preferably 2 to 20 mole times of the amic acid group, and the amount of the acid anhydride is 1 to 50 mole times, preferably 3 to 30 mole times of the amic acid group. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, and the like. Among them, pyridine is preferable because it has a suitable basicity for advancing the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like, and among them, acetic anhydride is preferable because purification after completion of the reaction becomes easy. The imidation rate by catalytic imidization can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

As a method of synthesizing the polyamic acid ester, as described above, a reaction of a tetracarboxylic acid diester dichloride and a diamine component, or a method of reacting a tetracarboxylic acid diester and a diamine component in the presence of a suitable condensing agent and a base. Can be lifted. Alternatively, it can also be obtained by polymerizing a polyamic acid in advance and esterifying a carboxylic acid in the amic acid using a polymer reaction.

Specifically, tetracarboxylic acid diester dichloride and diamine are mixed in the presence of a base and an organic solvent at -20°C to 150°C, preferably 0°C to 50°C, for 30 minutes to 24 hours, preferably 1 to It can be synthesized by reacting for 4 hours.

As the base, pyridine, triethylamine, and 4-dimethylaminopyridine can be used, but pyridine is preferred in order for the reaction to proceed gently. The addition amount of the base is an amount that is easy to remove, and from the viewpoint of easy to obtain a high molecular weight substance, it is preferably 2 to 4 times the mole relative to the tetracarboxylic acid diester dichloride.

When carrying out the polycondensation reaction in the presence of a condensing agent, triphenylphosphite, dicyclohexylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, N,N'-carbonyldi Imidazole, dimethoxy-1,3,5-triazinylmethylmorpholinium, O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate, O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluroniumhexafluorophosphite, (2,3-dihydro-2-thioxo-3-benzooxazolyl ) Phosphonic acid diphenyl, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)4-methoxymorpholinium chloride n-hydrate, etc. can be used.

Further, in the method of using the condensing agent, the reaction proceeds efficiently by adding Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferable. The amount of Lewis acid added is preferably 0.1 to 1.0 times the molar amount with respect to the tetracarboxylic acid diester.

The solvent used for the above reaction can be carried out as a solvent used when polymerizing the polyamic acid shown above, but from the solubility of the monomer and polymer, N-methyl-2-pyrrolidone and γ-butyrolactone are preferred. , These may be used alone or in combination of two or more. The concentration at the time of synthesis is preferably from 1 to 30% by mass, more preferably from 5 to 20% by mass, from the viewpoint that precipitation of the polymer is unlikely to occur and the high molecular weight is easily obtained. Further, in order to prevent hydrolysis of tetracarboxylic acid diester dichloride, the solvent used for synthesis of the polyamic acid ester is preferably dehydrated as much as possible, and it is preferable to prevent mixing of outside air in a nitrogen atmosphere.

Synthesis of polyamide can also be carried out in the same manner as polyamic acid ester.

When recovering the resulting polyamic acid, polyamic acid ester, polyimide, or polyamide from the reaction solution of polyamic acid, polyamic acid ester, polyimide, and polyamide, the reaction solution may be added to a poor solvent to precipitate. Examples of poor solvents used for precipitation include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, and water. The polymer injected into the poor solvent and precipitated can be collected by filtration and then dried at room temperature or heated under normal pressure or reduced pressure. Moreover, if the polymer recovered by precipitation is re-dissolved in an organic solvent and the operation of reprecipitating and recovering is repeated 2 to 10 times, impurities in the polymer can be reduced. Examples of the poor solvent at this time include alcohols, ketones, hydrocarbons, and the like, and when three or more types of poor solvents selected from these are used, the purification efficiency is further increased, so it is preferable.

The molecular weight of the polyamic acid, polyamic acid ester, polyimide or polyamide of the present invention is GPC (Gel It is preferable to set it as 5,000 to 1,000,000, and more preferably, it is 10,000 to 150,000 with the weight average molecular weight measured by the Permeation Chromatography) method.

<Liquid crystal aligning agent>

The liquid crystal aligning agent of this invention is a coating liquid for forming a liquid crystal aligning film, and is a solution in which a polymer component for forming a polymer film is dissolved in an organic solvent. Here, the polymer component contains at least one polymer selected from polyamic acid, polyamic acid ester, polyimide, and polyamide obtained by using the diamine represented by formula (1) which is the polymer of the present invention described above. The content of the polymer component contained in the liquid crystal aligning agent is preferably 1% by mass to 20% by mass, more preferably 3% by mass to 15% by mass, and particularly preferably 3% by mass to 10% by mass.

In the present invention, all of the polymer components may be the polymer of the present invention, or other polymers may be mixed with the polymer of the present invention. In that case, the content of other polymers other than the polymer of the present invention in the polymer component is 0.5% by mass to 15% by mass, preferably 1% by mass to 10% by mass.

Such other polymers are, for example, polyamic acids, polyamic acid esters, polyimides or polyamides obtained by using diamines other than the diamines represented by formula (1) as diamine components to be reacted with the tetracarboxylic dianhydride component. Can be mentioned.

The organic solvent (solvent) used for the liquid crystal aligning agent of this invention is not specifically limited if it is an organic solvent which dissolves a polymer component. The specific example is given below.

N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrroli Don, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, γ-butyrolactone, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, 3-part Toxic-N,N-dimethylpropanamide, 1,3-dimethyl-imidazolidinone, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethylene carbonate , Propylene carbonate, diglyme, and 4-hydroxy-4-methyl-2-pentanone. These may be used individually or may be mixed and used.

The liquid crystal aligning agent of this invention may contain components other than the said polymer component. Examples thereof include solvents and compounds that improve film thickness uniformity and surface smoothness when a liquid crystal aligning agent is applied, and compounds that improve adhesion between a liquid crystal aligning film and a substrate.

The following are mentioned as a specific example of the solvent (poor solvent) which improves the uniformity of the film thickness and surface smoothness.

For example, isopropyl alcohol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethyl Carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol Monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl Ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, Ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, 1-hexanol, n-hexane, n-pentane, n -Octane, diethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate Ethyl, 3-methoxy ethylpropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxypropionic acid propyl, 3-methoxy butyl propionate, 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-mono Ethyl ether-2-acetate, dipropylene glycol, 2-(2-ethoxypropoxy)propanol, lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester, lactate isoamyl ester, etc. Solvents with low surface tension, etc. Can be lifted.

These poor solvents may be used alone or in combination of plural types. When using such a solvent, it is preferable that it is 5 to 80 mass% of the whole solvent contained in a liquid crystal aligning agent, More preferably, it is 20 to 60 mass %.

As a compound which improves the uniformity of film thickness and surface smoothness, a fluorine-based surfactant, a silicone-based surfactant, a nonionic surfactant, etc. are mentioned.

More specifically, for example, FTOP EF301, EF303, EF352 (manufactured by Tochem Products), Megapack F171, F173, R-30 (manufactured by Diniphone Ink), Florade FC430, FC431 (manufactured by Sumitomo 3M) ), Asahigard AG710, Suflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Corporation), and the like. The ratio of use of these surfactants is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass with respect to 100 parts by mass of the resin component contained in the liquid crystal aligning agent.

As a specific example of the compound which improves the adhesiveness of a liquid crystal aligning film and a board|substrate, the functional silane containing compound, the epoxy group containing compound etc. shown below are mentioned.

For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3 -Aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxy Carbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetri Amine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl Acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3- Aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis(oxyethylene)-3-aminopropyltrimethoxysilane, N-bis(oxyethylene)-3-aminopropyltri Ethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol di Glycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetragly Cidyl-2,4-hexanediol, N,N,N',N'-tetraglycidyl-m-xylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane , N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, and the like.

Further, in addition to improving the adhesion between the substrate and the film, the following phenoplast additives may be introduced for the purpose of further preventing a decrease in electrical properties due to the backlight. Although specific phenoplast additives are shown below, it is not limited to this structure.

[Formula 19]

In the case of using a compound that improves adhesion to a substrate, the amount used is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass per 100 parts by mass of the polymer component contained in the liquid crystal aligning agent. If the amount is less than 0.1 parts by mass, the effect of improving the adhesion cannot be expected, and if the amount is more than 30 parts by mass, the liquid crystal orientation may deteriorate.

In the liquid crystal aligning agent of the present invention, in addition to the above, as long as the effect of the present invention is not impaired, for the purpose of changing electrical properties such as dielectric constant and conductivity of the liquid crystal aligning film, a dielectric material, a conductive material, and furthermore, a liquid crystal aligning film should be used. You may add a crosslinkable compound for the purpose of increasing the hardness and density of the film at the time.

<Liquid crystal alignment film/liquid crystal display element>

The liquid crystal aligning agent of the present invention can be used as a liquid crystal aligning film without alignment treatment in a vertical alignment application or the like after coating and firing on a substrate or the like and performing alignment treatment by rubbing treatment or light irradiation. In this case, the substrate to be used is not particularly limited as long as it is a substrate having high transparency, and a glass substrate or a plastic substrate such as an acrylic substrate or a polycarbonate substrate can be used. In addition, it is preferable from the viewpoint of simplification of the process to use a substrate on which an ITO (Indium Tin Oxide) electrode or the like for driving the liquid crystal is formed. In addition, in a reflective liquid crystal display device, an opaque material such as a silicon wafer may be used as long as it is only a substrate on one side, and a material that reflects light such as aluminum may be used as the electrode in this case.

The method of applying the liquid crystal aligning agent is not particularly limited, but industrially, a method of performing by screen printing, offset printing, flexo printing, ink jet or the like is common. Other coating methods include dip, roll coater, slit coater, spinner, and the like, and may be used depending on the purpose. Since the solubility in the solvent of the polymer obtained by using the diamine represented by the contained formula (1) is good, the liquid crystal aligning agent of this invention is excellent in printability. Therefore, when applied to a substrate or the like, precipitation and whitening (that is, generation of aggregates) are suppressed, and coating/film-forming properties are improved. Moreover, even if the standing time after application|coating to a board|substrate etc. is lengthened, a liquid crystal aligning film excellent in uniformity and transparency can be manufactured.

The firing after applying the liquid crystal aligning agent on the substrate is carried out at 50 to 300°C, preferably 80 to 250°C by a heating means such as a hot plate, and the solvent is evaporated to form a coating film. By this firing, the organic group A that can be desorbed by heat derived from diamine represented by formula (1) is desorbed from polyamic acid, polyamic acid ester, polyimide or polyamide, and the cyclization reaction or intermolecular reaction described above. Is spent on. Accordingly, the obtained liquid crystal alignment film has excellent rubbing resistance because it is difficult to be cut off during the rubbing treatment, and even when exposed to high temperature and high humidity for a long period of time, it is difficult to reduce the voltage retention even when exposed to a backlight. Moreover, since the structure of the polymer after firing becomes an electrochemically active structure, a liquid crystal alignment film in which RDC is difficult to accumulate can be obtained. If the thickness of the coating film formed after firing 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. Therefore, it is preferably 5 to 300 nm, more preferably Is 10 to 100 nm. When the liquid crystal is horizontally aligned or obliquely aligned, the coated film after firing is subjected to rubbing or polarized ultraviolet irradiation or the like.

In the liquid crystal display device of the present invention, after obtaining the substrate on which the liquid crystal aligning film was formed from the liquid crystal aligning agent of the present invention by the above-described method, a liquid crystal cell was produced by a known method to obtain a liquid crystal display device. To give an example, a liquid crystal cell comprising two substrates arranged to face each other, a liquid crystal layer formed between the substrates, and the liquid crystal alignment film formed between the substrate and the liquid crystal layer and formed by the liquid crystal aligning agent of the present invention. It is a liquid crystal display device. Examples of the liquid crystal display device of the present invention include a twisted nematic (TN: Twisted Nematic) method, a vertical alignment (VA: Vertical Alignment) method, a horizontal alignment (IPS: In-Plane Switching) method, and an OCB alignment (OCB: Optically). Compensated Bend), etc. are mentioned.

As a liquid crystal cell manufacturing method, a pair of substrates on which a liquid crystal alignment film was formed is prepared, spacers are scattered on the liquid crystal alignment film of one substrate, so that the liquid crystal alignment film surface is inside, and the other substrate is bonded together. Then, a method of sealing by injecting a liquid crystal under reduced pressure, or a method of attaching a substrate to seal the liquid crystal after dropping the liquid crystal on the surface of the liquid crystal alignment film on which the spacers are scattered can be exemplified. The thickness of the spacer at this time is preferably 1 to 30 µm, more preferably 2 to 10 µm.

As the liquid crystal, a positive liquid crystal having positive dielectric anisotropy or a negative liquid crystal having negative dielectric anisotropy, specifically, for example, Merck's MLC-2003, MLC-6608, MLC-6609, and the like can be used.

As described above, the liquid crystal display device produced by using the liquid crystal aligning agent of the present invention is excellent in reliability, and can be preferably used for a high-precision liquid crystal television with a large screen.

Example

Hereinafter, although an Example is given and this invention is demonstrated, it goes without saying that this invention is limited to these and is not interpreted.

The abbreviations of the compounds used in Examples and Comparative Examples are as follows. MW represents a molecular weight, and Boc represents a tert-butoxycarbonyl group (-COO-C(CH ₃ )).

In addition, Table 3 shows a list of polyamic acids (PAA) synthesized in Examples and Comparative Examples, and Table 4 shows a list of solvent-soluble polyimides (SPI) synthesized in Examples and Comparative Examples, respectively.

In addition, Table 5 shows a list of the liquid crystal aligning agents (AL) prepared in Examples and Comparative Examples, and Table 6 shows the printability, rubbing resistance, and cell display characteristics evaluation results of the liquid crystal aligning agents of Examples and Comparative Examples. , Table 7 shows the results of evaluation of characteristics of a liquid crystal cell using the liquid crystal aligning agent of Examples and Comparative Examples.

<Tetracarboxylic dianhydride>

A-1: 1,2,3,4-cyclobutanetetracarboxylic dianhydride (MW196)

A-2: 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid dianhydride (MW300)

A-3: Pyromellitic dianhydride (MW218)

A-4: Adipoyl chloride (MW183)

A-5: Terephthaloyl chloride (MW203)

[Formula 20]

<Diamine>

B-1: 1,4-phenylenediamine (MW108)

B-2: 3-aminobenzylamine (MW122)

B-3: 4,4-diaminodiphenylmethane (MW198)

[Formula 21]

B-4: 4-hexadecyloxy-1,3-diaminobenzene (MW348)

B-5: 4-(trans-4-heptylcyclohexyl)benzamide-2',4'-phenylenediamine (MW407)

[Formula 22]

B-6: N1,N4-bis(2-tert-butoxycarbonylamino-4-aminophenyl)succinamide (MW528)

B-7: N1,N4-bis(2-tert-butoxycarbonylamino-4-aminophenyl)adipamide (MW556)

B-8: N1,N4-bis(2-tert-butoxycarbonylamino-4-aminophenyl)terephthalamide (MW576)

B-9: 4-amino-N-(2-tert-butoxycarbonylamino-4-aminophenyl)benzamide (MW342)

[Formula 23]

<Organic solvent>

NMP: N-methyl-2-pyrrolidone

GBL: γ-butyrolactone

BCS ： Butyl Cellosolve

THF ： Tetrahydrofuran

DMF: N,N-dimethylformamide

Below, it shows about the evaluation method implemented in this Example.

<Measurement of molecular weight>

The molecular weight of a polymer (polyamic acid, polyamic acid ester, polyimide, polyamide) is determined by measuring the polymer by a GPC (room temperature gel permeation chromatography) device, and the number average molecular weight and weight average molecular weight in terms of polyethylene glycol and polyethylene oxide. Was calculated.

GPC device: manufactured by Shodex (GPC-101)

Column: Shodex company make (series of KD803, KD805)

Column temperature: 50 °C

Eluent: N,N-dimethylformamide (lithium bromide-hydrate (LiBr H ₂ O) as an additive is 30 mmol/L, phosphoric acid anhydrous crystal (o-phosphoric acid) is 30 mmol/L, tetrahydrofuran (THF) 10ml/l)

Flow rate: 1.0 ml/min

Standard samples for calibration curve preparation: TSK standard polyethylene oxide (molecular weight: about 900,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation, and polyethylene glycol (molecular weight: about 12,000, 4,000, 1,000) manufactured by Polymer Laboratories.

<Measurement of imidation rate>

The imidation ratio of the polyimide was measured as follows. 20 mg of the polyimide powder was put into an NMR sample tube, _{0.53 ml of deuterated dimethyl sulfoxide (DMSO-d 6} , 0.05% TMS mixture) was added and completely dissolved. A 500 MHz proton NMR was measured for this solution with an NMR analyzer (JNM-ECA500) manufactured by Nippon Electronics Datum.

The imidation ratio was calculated by the following formula. In addition, the imidation ratio of the polyimide which does not use the diamine represented by formula (1) calculated the value of "the amount of introduction of the formula (1) diamine at the time of polyamic acid polymerization" in the following formula as zero.

Imidation rate (%) =

(100-Formula (1) amount of diamine introduced during polymerization of polyamic acid (mol%)/2) × α

In the formula, α is a proton derived from a structure that does not change before and after imidation, as a reference proton, and the integrated peak value of this proton and the integrated value of the proton peak derived from the NH group of the amic acid appearing around 9.5 to 10.0 ppm are used. Then, it was calculated by the following equation.

α = (1-α·x/y)

In the above formula, x is the integrated value of the proton peak derived from the NH group of the amic acid, y is the integrated value of the peak of the reference proton, and α is the NH group of the amic acid in the case of polyamic acid (imidation ratio is 0%) It is the ratio of the number of reference protons to one proton.

<Production of liquid crystal cell>

The liquid crystal aligning agent was spin-coated on a glass substrate with a transparent electrode, dried on a hot plate at a temperature of 80° C. for 70 seconds, and then baked for 10 minutes in a nitrogen atmosphere using an IR oven at 220° C., and a film thickness of 100 nm A coating film of was formed. Using a cotton cloth (Yoshikawa YA-25C) with a rubbing device having a roll diameter of 120 mm, the coated surface was rubbed under conditions of a roll rotation speed of 1000 rpm, a roll advance speed of 50 mm/sec, and a press fit amount of 0.4 mm, and liquid crystal A substrate on which an alignment film was formed was obtained.

Two of these substrates were prepared, a 6 µm spacer was dispersed on the surface of the liquid crystal alignment film, and a sealing agent (Sumitomo Chemical Co., Ltd. NX-1500T) was printed from the top with a seal dispenser, and another one After bonding the substrate of the liquid crystal aligning film face to each other so that the rubbing direction goes straight, the sealing agent was cured (temporary curing: 80°C for 30 minutes, main curing: 150°C for 1 hour) to prepare an empty cell. Liquid crystal MLC-2003 (manufactured by Merck Japan) was injected into this empty cell by a vacuum injection method, and the injection port was sealed to obtain a twisted nematic liquid crystal cell.

In addition, for the production of a liquid crystal cell used for the evaluation of liquid crystal orientation described below, the rubbing conditions described above were at a roll rotation speed of 700 rpm, a roll advance speed of 50 mm/s, and a press fit amount of 0.2 mm, and rubbing when adhering. A rubbing treatment was performed so that the direction was opposite to the horizontal, to obtain a substrate on which a liquid crystal alignment film was formed. Using this, cell production was performed under the same conditions as described above, and an anti-parallel liquid crystal cell for evaluation of liquid crystal orientation was obtained.

<varnish (liquid crystal aligning agent) printability test>

The prepared liquid crystal aligning agent was applied on the washed Cr plate by performing flexographic printing using an alignment film printer ("Angstrom" manufactured by Nippon Photographic Printing Co., Ltd.) to perform a coating property test. About 1.0 ml of a liquid crystal aligning agent was dripped on an anilox roll, and after carrying out empty operation 10 times, the printing machine was stopped for 10 minutes, and the printing plate was dried. Thereafter, printing was performed on one Cr substrate, and the printed substrate was left on a hot plate at 70° C. for 5 minutes to pre-dry the coating film, and the film state was observed. Observation was observed with the naked eye and an optical microscope ("ECLIPSE ME600" manufactured by Nikon Corporation) 50 times, and mainly observed the film thickness unevenness and the film thickness unevenness of the edge portion.

<Evaluation of rubbing tolerance>

In the step of obtaining the substrate on which the liquid crystal alignment film was formed in <Preparation of the liquid crystal cell>, the surface of the liquid crystal alignment film was observed with a confocal laser microscope (real-time scanning laser microscope 1LM21D manufactured by Laser Tech Co., Ltd.), and evaluation was performed according to the following criteria. did. Table 6 shows the results.

Good: No scraping or rubbing damage was observed.

Poor: The film is peeled off or rubbing damage is observed with the naked eye.

<Liquid crystal orientation evaluation>

The initial alignment state of the anti-parallel liquid crystal cell for evaluation of liquid crystal orientation was visually observed through a polarizing plate. The evaluation criteria are shown below. Table 6 shows the results.

Good: It is well oriented.

Defect: Many spots of light leakage or misalignment are observed.

<Measurement of pretilt angle>

After heating the liquid crystal cell obtained by carrying out similarly to said <production of a liquid crystal cell> at 105 degreeC for 10 minutes, the pretilt angle was measured. For the measurement, an Axo Scan Mura Matrix Polarimeter manufactured by Opt Matrix Co., Ltd. was used.

<Measurement of VHR (voltage retention)>

A voltage of 1 V was applied for 60 μs at a temperature of 60° C. for 60 μs to the twisted nematic liquid crystal cell produced by the method described in <Preparation of a liquid crystal cell>, and the voltage was maintained to some extent by measuring the voltage after 166.7 ms. It was calculated as a voltage retention rate (initial VHR). The results are shown in the "initial" column of Table 7. In addition, for the measurement of the voltage retention rate, a VHR-1 voltage retention measurement device manufactured by Toyo Technica was used.

Moreover, after exposing the liquid crystal cell which performed initial VHR measurement to a backlight (a backlight for LCD used for a notebook PC) for 240 hours, VHR was measured by the method similar to the initial VHR (VHR after backlight aging exposure). The results are shown in the column of "Backlight Aging" in Table 7.

And after leaving the liquid crystal cell which measured VHR after exposure to backlight aging for 240 hours in an environment of 70° C. and 70% relative humidity, VHR was measured in the same manner as the initial VHR (VHR after high temperature and high humidity aging). The results are shown in the column of "high temperature and high humidity aging" in Table 7.

<Measurement of RDC (residual DC voltage)>

To the twisted nematic liquid crystal cell produced by the method described in the above <production of a liquid crystal cell>, a DC voltage was applied from 0 V to 1.0 V at intervals of 0.1 V at a temperature of 23°C, and the flicker amplitude level at each voltage was photoelectric. Measurement was performed using a conversion device, and a calibration curve for the flicker amplitude level and the applied voltage was created. After the cell was earthed for 5 minutes and left to stand, the flicker amplitude level immediately after the AC voltage was applied to V50 (the voltage at which the luminance would be halved) and the DC voltage 5.0 V was applied for 1 hour, and only the DC voltage was set to 0 V, was measured. RDC was estimated by comparing it with a calibration curve prepared in advance. This RDC estimation method is called the flicker reference method.

<Synthesis of diamine>

(Example 1) Synthesis of N1,N4-bis[(2-tert-butoxycarbonylamino)-4-aminophenyl]succinamide [B-6]

[Formula 24]

Step-1 Synthesis of 4-nitro 2-tertbutoxycarbonylaminoaniline [NB-NA]

In a 3 L 4 necked flask equipped with a stirrer and a nitrogen inlet tube, 200.0 g (1.31 mol) of 4-nitro-1,2-phenylenediamine was measured, 1 L of THF and 300 ml of DMF were added, and nitrogen It dissolved by heating at about 60 degreeC in an atmosphere, and 285.2 g (1.44 mol) of tertbutyl bicarbonate was slowly added dropwise over 2 hours using a dropping funnel, and refluxed for 4 hours.

After the reaction was completed, the reaction solution was concentrated with a rotary evaporator, and the obtained residue was dissolved in THF, poured into a mixed solvent of ethyl acetate:n-hexane (volume ratio 7:3), and recrystallized to 248 g of a yellow solid ( Yield about 75%) was obtained. The obtained solid was 4-nitro-2-tert butoxycarbonylaminoaniline. ^{The structure was confirmed by 1} H-NMR spectrum, which is the nuclear magnetic resonance spectrum of hydrogen atoms in the molecule. Measurement data are shown below.

Step-2 Synthesis of N1,N4-bis[(2-tert-butoxycarbonylamino)-4-nitrophenyl]succinamide

20.0 g (78.97 mmol) of 4-nitro-2-tertbutoxycarbonylaminoaniline and 15.6 g (197.43 mmol) of pyridine (also referred to as “Py”) were measured in a 500 ml four-neck flask, and dehydrated THF 300 Dissolved in ml, while maintaining 10°C or less in an ice bath, 5.51 g (35.54 mmol) of THF solution (20 wt%) of succinic acid dichloride was slowly added dropwise using a dropping funnel under a nitrogen atmosphere, followed by stirring at room temperature for 24 hours. Made it. As the reaction proceeds, a solid has been deposited. After completion of the reaction, 300 ml of pure water was added to the reaction solution and stirred for a while, and the reaction solution was poured into 1 L of methanol and stirred for a while. The solid was filtered and further washed several times with 500 ml of methanol to obtain 19.5 g of a pale yellow solid (yield: 92%). The obtained solid was N1,N4-bis[(2-tert-butoxycarbonylamino)-4-nitrophenyl]succinamide.

Step-3 Synthesis of [B-6]

3 To a 300 ml 4-neck flask equipped with a bangkok and a stirrer, 10.0 g of N1,N4-bis[(2-tert-butoxycarbonylamino)-4-nitrophenyl]succinamide and palladium carbon (10 wt%) were added. 1.0 g was measured, 200 ml of DMF was added, degassing under reduced pressure and hydrogen substitution were performed, and the reaction was carried out at room temperature for 48 hours.

After completion of the reaction, palladium carbon was removed with a PTFE membrane filter, and the filtrate was poured into 500 ml of methanol cooled to 10°C or less, and stirred for a while to precipitate a solid. The obtained solid was recovered, washed with methanol, washed with a mixed solvent of ethyl acetate and n-hexane, and dried in vacuo at 60°C, whereby 7.84 g of a white solid as the target diamine ([B-6]) ( Yield: 87%) was obtained. ^{Its structure was confirmed by 1} H-NMR spectrum, which is the nuclear magnetic resonance spectrum of hydrogen atoms in the molecule. Measurement data are shown below.

(Example 2) Synthesis of N1,N4-bis[(2-tert-butoxycarbonylamino)-4-aminophenyl]adipamide [B-7]

[Formula 25]

STEP-1 Synthesis of N1,N4-bis[(2-tert-butoxycarbonylamino)-4-nitrophenyl]adipamide

20.0 g (78.97 mmol) of 2-tertbutoxycarbonylamino-4-nitroaniline and 15.6 g (197.43 mmol) of pyridine were measured in a 500 ml four-neck flask, and a mixed solvent of 300 ml of dehydrated THF and 100 ml of DMF In an ice bath, while maintaining 10°C or less in an ice bath, 6.5 g (35.54 mmol) THF solution (20 wt%) of adipoyl chloride was slowly added dropwise using a dropping funnel, and stirred at room temperature for 24 hours . As the reaction proceeds, a solid has been deposited. After completion of the reaction, 300 ml of pure water was added to the reaction solution and stirred for a while, and the reaction solution was poured into 1 L of methanol and stirred for a while. The solid was filtered and further washed several times with 500 ml of methanol to obtain 19.5 g of a white gray solid (yield: 89%). The obtained solid was N1,N4-bis[(2-tert-butoxycarbonylamino)-4-nitrophenyl]adipamide.

STEP-2 Synthesis of N1,N4-bis[(2-tert-butoxycarbonylamino)-4-aminophenyl]adipamide [B-7]

3 In a 300 ml 4-neck flask equipped with a bangkok and a stirrer, 15.0 g of N1,N4-bis[(2-tert-butoxycarbonylamino)-4-nitrophenyl]adipamide and palladium carbon (5 wt%) 1.5 g of was measured, 250 ml of DMF was added, degassing under reduced pressure and hydrogen substitution were performed, and the reaction was carried out at room temperature for 48 hours.

After completion of the reaction, palladium carbon was removed with a membrane filter made of PTFE (polytetrafluoroethylene), and the filtrate was poured into 500 ml of methanol cooled to 10°C or less, and stirred for a while to precipitate a solid. The obtained solid was recovered, washed with methanol, washed with a mixed solvent of ethyl acetate and n-hexane, and dried under vacuum at 60°C to obtain 12.2 g of a light gray solid as the target diamine (yield: 90%). Got it. The obtained solid was [B-7]. ^{Its structure was confirmed by 1} H-NMR spectrum, which is the nuclear magnetic resonance spectrum of hydrogen atoms in the molecule. Measurement data are shown below.

(Example 3) Synthesis of N1,N4-bis[(2-tert-butoxycarbonylamino)-4-aminophenyl]terephthalamide [B-8]

[Formula 26]

STEP-1 Synthesis of N1,N4-bis[(2-tert-butoxycarbonylamino)-4-nitrophenyl]terephthalamide

20.0 g (78.97 mmol) of 2-tertbutoxycarbonylamino-5-nitroaniline and 15.6 g (197.43 mmol) of pyridine were measured in a 500 ml four-neck flask, and a mixed solvent of 300 ml of dehydrated THF and 100 ml of DMF In an ice bath, while maintaining 10° C. or less in an ice bath, a THF solution (20 wt%) of 7.2 g (35.54 mmol) of terephthaloyl chloride was slowly added dropwise using a dropping funnel, and stirred at room temperature for 24 hours. Made it. As the reaction proceeds, a solid has been deposited. After completion of the reaction, 300 ml of pure water was added to the reaction solution and stirred for a while, and the reaction solution was poured into 1 L of methanol and stirred for a while. The solid was filtered and further washed several times with 500 ml of methanol to obtain 21.5 g of a pale yellow solid (yield: 95%). The obtained solid was N1,N4-bis[(2-tert-butoxycarbonylamino)-4-nitrophenyl]terephthalamide.

STEP-2 Synthesis of N1,N4-bis[(2-tert-butoxycarbonylamino)-4-aminophenyl]terephthalamide [B-8]

3 To a 300 ml four-neck flask equipped with a bangkok and a stirrer, 15.0 g of N1,N4-bis[(2-tert-butoxycarbonylamino)-4-nitrophenyl]terephthalamide and palladium carbon (5 wt%) were added. After measuring 1.5 g, 250 ml of DMF was added, degassing under reduced pressure and hydrogen substitution were performed, and the reaction was carried out at room temperature for 48 hours.

After completion of the reaction, palladium carbon was removed with a PTFE membrane filter, and the filtrate was poured into 500 ml of methanol cooled to 10°C or less, and stirred for a while to precipitate a solid. The obtained solid was recovered, washed with methanol, washed with a mixed solvent of ethyl acetate and n-hexane, and dried under vacuum at 60°C to obtain 12.5 g of a light gray solid as the target diamine (yield: 92%). Got it. The obtained solid was [B-8]. ^{Its structure was confirmed by 1} H-NMR spectrum, which is the nuclear magnetic resonance spectrum of hydrogen atoms in the molecule. Measurement data are shown below.

(Example 4) Synthesis of 4-amino-N-[(2-tert-butoxycarbonylamino)-4-aminophenyl]benzamide [B-9]

[Formula 27]

STEP-1 Synthesis of 4-nitro-N-[(2-tert-butoxycarbonylamino)-4-nitrophenyl]benzamide

15.0 g (59.23 mmol) of 2-tertbutoxycarbonylamino-4-nitroaniline and 7.0 g (88.85 mmol) of pyridine were measured in a 500 ml four-neck flask, and a mixed solvent of 300 ml of dehydrated THF and 100 ml of DMF In an ice bath, while maintaining 10°C or less in an ice bath, 12.1 g (65.15 mmol) of 4-nitrobenzoyl chloride was slowly added thereto, followed by stirring at room temperature for 24 hours. As the reaction proceeds, a solid has been deposited. After completion of the reaction, 300 ml of pure water was added to the reaction solution and stirred for a while, and the reaction solution was poured into 1 L of methanol and stirred for a while. The solid was filtered and further washed several times with 500 ml of methanol to obtain 22.2 g of a white solid (yield: 93%). The obtained solid was 4-nitro-N-[(2-tert-butoxycarbonylamino)-4-nitrophenyl]benzamide.

STEP-2 Synthesis of 4-amino-N-[(2-tert-butoxycarbonylamino)-4-aminophenyl]benzamide [B-9]

3 In a 300 ml 4-neck flask equipped with a bangkok and a stirrer, 20.0 g of 4-nitro-N-[(2-tert-butoxycarbonylamino)-4-nitrophenyl]benzamide and palladium carbon (5 wt%) 2.0 g of was measured, 400 ml of DMF was added, degassing under reduced pressure and hydrogen substitution were performed, and the reaction was carried out at room temperature for 48 hours.

After completion of the reaction, palladium carbon was removed with a PTFE membrane filter, and the filtrate was poured into 1 L of methanol cooled to 10°C or less to precipitate a solid, followed by stirring for a while. The obtained solid was recovered, washed with methanol, washed with a mixed solvent of ethyl acetate and n-hexane, and dried in vacuo at 60°C to obtain 15.3 g (yield: 90%) of a white solid as the target diamine. . The obtained solid was [B-9]. ^{Its structure was confirmed by 1} H-NMR spectrum, which is the nuclear magnetic resonance spectrum of hydrogen atoms in the molecule. Measurement data are shown below.

<Preparation of liquid crystal aligning agent>

(Example 5) Polymerization of polyamic acid [PAA-1: A-1/B-6] and preparation of liquid crystal aligning agent [AL-1]

2.64 g (5.00 mmol) of B-6 was measured in a 50 ml four-necked flask equipped with a nitrogen introduction tube and a mechanical stirrer, 20.3 g of NMP was added to dissolve it, and cooled to about 10° C. in a nitrogen atmosphere, 0.93 g (4.75 mmol) of A-1 was added little by little, it returned to room temperature, and it reacted for 6 hours, and the 15 mass% solution of polyamic acid (PAA-1) was obtained. The number average molecular weight of obtained PAA-1 was 11,300, and the weight average molecular weight was 24,500.

10.0 g of this polyamic acid solution was measured in a 50 ml Erlenmeyer flask equipped with a stirrer, 7.5 g of NMP and 7.5 g of BCS were added, followed by stirring at room temperature for 30 minutes, and PAA-1 was 6.0% by mass, The liquid crystal aligning agent [AL-1] of 64 mass% of NMP and 30 mass% of BCS was obtained.

(Example 6) Polymerization of polyamic acid [PAA-2: A-1/B-7] and preparation of liquid crystal aligning agent [AL-2]

2.78 g (5.00 mmol) of B-7 was measured in a 50 ml four-necked flask equipped with a nitrogen introduction tube and a mechanical stirrer, 21.1 g of NMP was added and dissolved, and cooled to about 10° C. in a nitrogen atmosphere, 0.93 g (4.75 mmol) of A-1 was added little by little, and it returned to room temperature, and it reacted for 6 hours, and the 15 mass% solution of polyamic acid (PAA-2) was obtained. The number average molecular weight of obtained PAA-2 was 13,400, and the weight average molecular weight was 30,100.

10.0 g of this polyamic acid solution was measured in a 50 ml Erlenmeyer flask equipped with a stirrer, 7.5 g of NMP and 7.5 g of BCS were added, followed by stirring at room temperature for 30 minutes, and PAA-2 was 6.0% by mass, The liquid crystal aligning agent [AL-2] of 64 mass% of NMP and 30 mass% of BCS was obtained.

(Example 7) Polymerization of polyamic acid [PAA-3: A-1/B-8] and preparation of liquid crystal aligning agent [AL-3]

2.88 g (5.00 mmol) of B-8 was measured in a 50 ml four-necked flask equipped with a nitrogen introduction tube and a mechanical stirrer, 21.1 g of NMP was added and dissolved, and cooled to about 10° C. in a nitrogen atmosphere, 0.93 g (4.75 mmol) of A-1 was added little by little, and it returned to room temperature, and it reacted for 6 hours, and the 15 mass% solution of polyamic acid (PAA-3) was obtained. The number average molecular weight of obtained PAA-3 was 10,700, and the weight average molecular weight was 25,200.

10.0 g of this polyamic acid solution was measured in a 50 ml Erlenmeyer flask equipped with a stirrer, 7.5 g of NMP and 7.5 g of BCS were added, followed by stirring at room temperature for 30 minutes, and PAA-3 was 6.0% by mass, The liquid crystal aligning agent [AL-3] of 64 mass% of NMP and 30 mass% of BCS was obtained.

(Example 8) Polymerization of polyamic acid [PAA-4: A-1/B-9] and preparation of liquid crystal aligning agent [AL-4]

In a 50 ml four-necked flask equipped with a nitrogen introduction tube and a mechanical stirrer, 1.71 g (5.00 mmol) of B-9 was measured, 15.00 g of NMP was added and dissolved, and cooled to about 10° C. in a nitrogen atmosphere, 0.93 g (4.75 mmol) of A-1 was added little by little, and it returned to room temperature, and it reacted for 6 hours, and the 15 mass% solution of polyamic acid (PAA-4) was obtained. The number average molecular weight of obtained PAA-4 was 11,100, and the weight average molecular weight was 23,500.

10.0 g of this polyamic acid solution was measured in a 50 ml Erlenmeyer flask equipped with a stirrer, 7.5 g of NMP and 7.5 g of BCS were added, followed by stirring at room temperature for 30 minutes, and PAA-4 was 6.0% by mass, The liquid crystal aligning agent [AL-4] of 64 mass% of NMP and 30 mass% of BCS was obtained.

(Example 9) Polymerization of polyamic acid [PAA-5: A-3/B-6] and preparation of liquid crystal aligning agent [AL-5]

2.64 g (5.00 mmol) of B-6 was measured in a 50 ml four-necked flask equipped with a nitrogen introduction tube and a mechanical stirrer, 20.7 g of NMP was added and dissolved, and cooled to about 10° C. in a nitrogen atmosphere, 1.01 g (4.65 mmol) of A-3 was added little by little, it returned to room temperature, and it reacted for 6 hours, and the 15 mass% solution of polyamic acid (PAA-5) was obtained. The number average molecular weight of obtained PAA-5 was 10,800, and the weight average molecular weight was 22,300.

10.0 g of a solution of this polyamic acid was measured in a 50 ml Erlenmeyer flask equipped with a stirrer, 7.5 g of NMP and 7.5 g of BCS were added, followed by stirring at room temperature for 30 minutes, and PAA-5 was 6.0% by mass, The liquid crystal aligning agent [AL-5] of 64 mass% of NMP and 30 mass% of BCS was obtained.

(Example 10) Polymerization of polyamic acid [PAA-6: A-3/B-7] and preparation of liquid crystal aligning agent [AL-6]

2.78 g (5.00 mmol) of B-7 was measured in a 50 ml four-necked flask equipped with a nitrogen introduction tube and a mechanical stirrer, 21.5 g of NMP was added to dissolve it, and cooled to about 10° C. in a nitrogen atmosphere, 1.01 g (4.65 mmol) of A-3 was added little by little, returned to room temperature, and it was made to react for 6 hours, and the 15 mass% solution of polyamic acid (PAA-6) was obtained. The number average molecular weight of obtained PAA-6 was 11,900, and the weight average molecular weight was 24,900.

10.0 g of this polyamic acid solution was measured in a 50 ml Erlenmeyer flask equipped with a stirrer, 7.5 g of NMP and 7.5 g of BCS were added, followed by stirring at room temperature for 30 minutes, and PAA-6 was 6.0% by mass, The liquid crystal aligning agent [AL-6] of 64 mass% of NMP and 30 mass% of BCS was obtained.

(Example 11) Polymerization of polyamic acid [PAA-7: A-1/B-1, B-7(30), B-4(10)] and preparation of liquid crystal aligning agent [AL-7]

In a 50 ml four-necked flask equipped with a nitrogen inlet tube and a mechanical stirrer, measure 0.64 g (6.00 mmol) of B-1, 1.67 g (3.00 mmol) of B-7, and 0.35 g (1.00 mmol) of B-4. Then, 25.89 g of NMP was added and dissolved, cooled to about 10° C. in a nitrogen atmosphere, 1.87 g (9.50 mmol) of A-1 was added little by little, returned to room temperature, and reacted for 6 hours, 15% by mass of polyamic acid A solution of (PAA-7) was obtained. The number average molecular weight of obtained PAA-7 was 12,200, and the weight average molecular weight was 26,300.

10.0 g of this polyamic acid solution was measured in a 50 ml Erlenmeyer flask equipped with a stirrer, 7.5 g of NMP and 7.5 g of BCS were added, followed by stirring at room temperature for 30 minutes, and PAA-7 was 6.0% by mass, The liquid crystal aligning agent [AL-7] of 64 mass% of NMP and 30 mass% of BCS was obtained.

(Example 12) Synthesis of soluble polyimide [SPI-1: A-1/B-2, B-7(40), B-5(5)] and preparation of liquid crystal aligning agent [AL-8]

In a 50 ml four-necked flask equipped with a nitrogen introduction tube and a mechanical stirrer, measure 1.34 g (11.00 mmol) of B-2, 4.45 g (8.00 mmol) of B-7, and 0.41 g (1.00 mmol) of B-5. Then, 56.27 g of NMP was added to dissolve it, cooled to about 10°C in a nitrogen atmosphere, and 3.84 g (19.60 mmol) of A-1 was added little by little, returned to room temperature, and reacted for 6 hours, 15% by mass of polyamic acid. A solution of (PAA-8) was obtained.

To a 200 ml Erlenmeyer flask equipped with a stirrer, 50.0 g of the polyamic acid solution obtained above was measured, 56.54 g of NMP, 3.43 g (25.25 mmol) of acetic anhydride, and 1.07 g (13.46 mmol) of pyridine were added. After stirring at room temperature for 30 minutes, it stirred at 50 degreeC for 3 hours, and was made to react. After completion of the reaction, it was slowly poured into 300 ml of methanol to precipitate a polymer, stirred for 30 minutes, and then filtered to recover a solid. After sufficiently washing the obtained solid with methanol, polyimide [SPI-1] was obtained by vacuum drying at 100°C. The number average molecular weight of this polyimide was 12,100, the weight average molecular weight was 25,300, and the imidation ratio was 87%.

2.00 g of SPI-1 was measured in a 50 ml Erlenmeyer flask equipped with a stirrer, 18.0 g of GBL was added, stirred at 50° C. for 24 hours to dissolve, confirming that it was completely dissolved, and 3.33 g of GBL, BCS The liquid crystal aligning agent [AL-8] with 6.0 mass% of SPI-1, 64 mass% of GBL, and 30 mass of BCS was obtained by adding 10.0 g of and stirring at room temperature for 30 minutes.

(Example 13) Synthesis of soluble polyimide [SPI-2: A-2/B-1, B-7(30), B-4(10)]

In a 50 ml four-necked flask equipped with a nitrogen inlet tube and a mechanical stirrer, measure 0.65 g (6.00 mmol) of B-1, 1.67 g (3.00 mmol) of B-7, and 0.35 g (1.00 mmol) of B-4. Then, 31.79 g of NMP was added to dissolve it, cooled to about 10°C in a nitrogen atmosphere, and 3.84 g (19.60 mmol) of A-2 was added little by little, returned to room temperature, and reacted for 6 hours, 15% by mass of polyamic acid. A solution of (PAA-9) was obtained.

To a 100 ml Erlenmeyer flask equipped with a stirrer, 50.0 g of the solution of the polyamic acid obtained above was measured, 56.54 g of NMP and 13.72 g (134.36 mmol) of acetic anhydride and 6.38 g (80.62 mmol) of pyridine were added to room temperature. After stirring at 40 degreeC for 30 minutes, it stirred and made it react at 40 degreeC for 3 hours. After completion of the reaction, it was slowly poured into 400 ml of methanol to precipitate a polymer, stirred for 30 minutes, and then filtered to collect a solid. After sufficiently washing the obtained solid with methanol, polyimide [SPI-2] was obtained by vacuum drying at 100°C. The number average molecular weight of this polyimide was 10,400, the weight average molecular weight was 21,500, and the imidation ratio was 85%.

2.00 g of SPI-2 was measured in a 50 ml Erlenmeyer flask equipped with a stirrer, 18.0 g of GBL was added, stirred at 50° C. for 24 hours to dissolve, confirming that it was completely dissolved, and 13.33 g of GBL was added. By stirring at room temperature for 30 minutes, a polyimide solution [SPI-2S] having 6.0 mass% of SPI-2 and 94 mass% of GBL was obtained.

(Example 14) Polymerization of polyamic acid [PAA-10: A-1, A-3(50)/B-3]

In a 200 ml four-neck flask equipped with a nitrogen introduction tube and a mechanical stirrer, 9.91 g (50.00 mmol) of B-3 was measured, 56.04 g of NMP and 56.04 g of GBL were added and dissolved, and about 10 in a nitrogen atmosphere. It cooled to °C, A-1 was measured 4.41 g (22.50 mmol), added little by little, 5.45 g (25.00 mmol) of A-3 was added little by little, returned to room temperature, and reacted for 6 hours, 15 mass% polya A solution of mixed acid (PAA-10) was obtained. The number average molecular weight of obtained PAA-10 was 10,500, and the weight average molecular weight was 22,400.

100.00 g of the polyamic acid solution obtained above was measured in a 500 ml Erlenmeyer flask equipped with a stirrer, 23.33 g of GBL, 26.67 g of NMP, and 50.00 g of BCS were added, followed by stirring at room temperature for 30 minutes, and PAA A polyamic acid solution [PAA-10S] having 6.0 mass% of -10, 20 mass% of NMP, and 15 mass% of BCS was obtained.

(Example 15) Preparation of liquid crystal aligning agent [AL-9]

In a 100 ml Erlenmeyer flask equipped with a stirrer, 20.00 g of the polyimide solution [SPI-2S] obtained in Example 13 and 80.00 g of the polyamic acid solution [PAA-10S] obtained in Example 14 were measured, and at room temperature Liquid crystal aligning agent [AL-9] was obtained by stirring for 24 hours.

(Example 16) Polymerization of polyamide [PA-1: A-4, A-1/B-6] and preparation of liquid crystal aligning agent [AL-10]

5.28 g (10.00 mmol) of B-6, 16.7 g of NMP, and 1.98 g (25.00 mmol) of pyridine were added to a 100 ml four-necked flask equipped with a nitrogen introduction tube and a stirrer, and cooled to about 10°C, and A- 0.91 g (4.80 mmol) of 4 and 1.02 g (5.00 mmol) of A-1 were added, and the mixture was returned to room temperature and reacted under a nitrogen atmosphere for 24 hours to obtain a solution having a concentration of 20% by mass of polyamide (PA-1).

To this solution of polyamide (PA-1), 32.2 g of NMP was added to make it 8.0%, and it was slowly poured into 500 ml of methanol cooled to about 10°C while stirring to precipitate a solid. The precipitated solid was recovered, further dispersed and washed twice in total with 200 ml of methanol, and dried under reduced pressure at 100°C to obtain a pale brown powder of polyamide (PA-1). The number average molecular weight of this polyamide was 11,600, and the weight average molecular weight was 23,000.

2.00 g of polyamide (PA-1) was measured, 18.0 g of GBL was added, stirred at 50°C for 24 hours to dissolve, confirming that it was completely dissolved, 3.33 g of GBL, 10.0 g of BCS, and 30 at room temperature. By stirring for minutes, the liquid crystal aligning agent [AL-10] of 6.0 mass% of PA-1, 64 mass% of GBL, and 30 mass% of BCS was obtained.

(Comparative Example 1) Polymerization of polyamic acid [PAA-11: A-1/B-3] and liquid crystal aligning agent

Preparation of [AL-11]

In a 50 ml four-neck flask equipped with a nitrogen introduction tube and a mechanical stirrer, 1.98 g (10.00 mmol) of B-3 was measured, 21.79 g of NMP was added to dissolve it, and cooled to about 10°C in a nitrogen atmosphere. 1.86 g (9.50 mmol) of A-1 was added little by little, returned to room temperature, and it was made to react for 6 hours, and the 15 mass% solution of polyamic acid (PAA-11) was obtained. The number average molecular weight of 11,400 and the weight average molecular weight of obtained PAA-11 were 24,300.

10.0 g of this polyamic acid solution was measured in a 50 ml Erlenmeyer flask equipped with a stirrer, 7.5 g of NMP and 7.5 g of BCS were added, followed by stirring at room temperature for 30 minutes, and PAA-11 was 6.0% by mass, The liquid crystal aligning agent [AL-11] of 64 mass% of NMP and 30 mass% of BCS was obtained.

(Comparative Example 2) Polymerization of polyamic acid [PAA-12: A-1/B-1] and liquid crystal aligning agent

Preparation of [AL-12]

1.96 g (10.00 mmol) of A-1 was measured in a 50 ml four-necked flask equipped with a nitrogen introduction tube and a mechanical stirrer, 16.81 g of NMP was added and stirred, and cooled to about 10° C. in a nitrogen atmosphere. 1.01 g (9.50 mmol) of B-1 was gradually added to the slurry-like solution, returned to room temperature, and reacted for 6 hours to obtain a 15% by mass solution of polyamic acid (PAA-12). The number average molecular weight of 13,500 and the weight average molecular weight of obtained PAA-12 were 28,900.

10.0 g of this polyamic acid solution was measured in a 50 ml Erlenmeyer flask equipped with a stirrer, 7.5 g of NMP and 7.5 g of BCS were added, followed by stirring at room temperature for 30 minutes, and PAA-12 was 6.0% by mass, The liquid crystal aligning agent [AL-12] of 64 mass% of NMP and 30 mass% of BCS was obtained.

(Comparative Example 3) Polymerization of soluble polyimide [SPI-3: A-1/B-2, B-4(10)] and preparation of liquid crystal aligning agent [AL-12]

In a 50 ml four-neck flask equipped with a nitrogen introduction tube and a mechanical stirrer, 1.64 g (13.50 mmol) of B-2 and 0.52 g (1.5 mmol) of B-4 were measured, and 28.48 g of NMP was added, followed by stirring. Then, it cooled to about 10 degreeC in nitrogen atmosphere, 2.85 g (14.55 mmol) of A-1 was added little by little, returned to room temperature, and it reacted for 6 hours, and obtained the 15 mass% solution of polyamic acid (PAA-13).

In a 200 ml Erlenmeyer flask equipped with a stirrer, 30.0 g of the polyamic acid solution obtained above was measured, 45.00 g of NMP, 3.14 g (30.74 mmol) of acetic anhydride and 1.35 g (17.01 mmol) of pyridine were added, and room temperature After stirring for 30 minutes at 50° C., the mixture was stirred at 50° C. for 3 hours to react, but gelation occurred during the reaction, and preparation of a soluble polyimide was not possible. Therefore, it was not possible to prepare AL-13.

(Comparative Example 4) Polymerization of soluble polyimide [SPI-4: A-2/B-1, B-4(10)]

In a 50 ml four-necked flask equipped with a nitrogen introduction tube and a mechanical stirrer, 1.45 g (13.50 mmol) of B-1 and 0.52 g (1.50 mmol) of B-4 were measured, and 36.25 g of NMP was added to dissolve it. Then, it cooled to about 10 degreeC in nitrogen atmosphere, 4.41 g (14.7 mmol) was added little by little to A-2, and it returned to room temperature, and it reacted for 6 hours, and obtained the 15 mass% solution of polyamic acid (PAA-14).

To a 100 ml Erlenmeyer flask equipped with a stirrer, 30.0 g of the solution of the polyamic acid obtained above was measured, 45.00 g of NMP, 10.77 g (105.52 mmol) of acetic anhydride, and 5.01 g (63.31 mmol) of pyridine were added. After stirring at room temperature for 30 minutes, it stirred at 40 degreeC for 3 hours, and was made to react. After completion of the reaction, it was slowly poured into 300 ml of methanol to precipitate a polymer, stirred for 30 minutes, and then filtered to recover a solid. After sufficiently washing the obtained solid with methanol, polyimide [SPI-4] was obtained by vacuum drying at 100°C. The number average molecular weight of this polyimide was 10,700, the weight average molecular weight was 22,500, and the imidation ratio was 88%.

2.00 g of SPI-4 was measured in a 50 ml Erlenmeyer flask equipped with a stirrer, 18.0 g of GBL was added, stirred at 50° C. for 24 hours to dissolve, confirming that it was completely dissolved, and 13.33 g of GBL was added. By stirring at room temperature for 30 minutes, a polyimide solution [SPI-4S] having 6.0 mass% of SPI-4 and 94 mass% of GBL was obtained.

In a 100 ml Erlenmeyer flask equipped with a stirrer, 20.00 g of the polyimide solution SPI-4S obtained by the above method and 80.00 g of the polyamic acid solution [PAA-10S] obtained in Example 14 were measured, and then at room temperature for 24 hours. It stirred and obtained the liquid crystal aligning agent [AL-14].

[Table 3]

[Table 4]

[Table 5]

[Table 6]

[Table 7]

*2 VHR measurement was performed in the order of initial stage, backlight aging, and high-temperature/high-humidity aging.

*3 RDC measurement is performed after initial VHR measurement, AC voltage: V 50 (approximately 4.8 to 5.0 Vp-p), DC voltage: 5.0 V, DC application time: 1 hour, and RDC 1 hour after DC application It was carried out by the Flickr reference method.

As shown in Tables 6 and 7, Examples 1 to 12 and 15 to 16 using a liquid crystal aligning agent containing a polymer obtained using a diamine represented by the formula (1) of the present invention are all excellent in rubbing resistance and liquid crystal alignment. In addition, it was confirmed that RDC was difficult to accumulate, and a liquid crystal alignment film excellent in backlight resistance and high temperature and high humidity resistance could be produced. Moreover, the printability of the liquid crystal aligning agent of these Examples to the board|substrate etc. was also favorable. That is, the polymer obtained by using the diamine represented by the formula (1) of the present invention has high solubility in a solvent and is less likely to cause precipitation or whitening during printing, so that coating and film forming properties can be improved, and good printing An excellent liquid crystal aligning agent can be obtained. Moreover, since solubility in a solvent becomes high, it becomes possible to introduce a large number of poor solvents with good wettability of the substrate, and the printability can be further improved.

On the other hand, in Comparative Examples 1 to 4 in which the diamine represented by Formula (1) of the present invention is not used, all the characteristics of the rubbing resistance, liquid crystal alignment, RDC, backlight resistance and high temperature and high humidity resistance of the liquid crystal aligning film, and the printability of the liquid crystal aligning agent. Could not be satisfied.

Industrial applicability

The liquid crystal aligning film of the present invention is resistant to film peeling or chipping during rubbing, and it is difficult to accumulate initial charge even when a DC voltage is applied, and it is difficult to reduce the voltage retention even when exposed to high temperature and high humidity for a long period of time, but to a backlight. Is obtained. Therefore, the liquid crystal display element produced by using the liquid crystal aligning agent of the present invention can be a highly reliable liquid crystal display element, and a TN liquid crystal display element, a STN liquid crystal display element, a TFT liquid crystal display element, a VA liquid crystal display element, and an IPS It is suitably used for display elements by various methods, such as a liquid crystal display element and an OCB liquid crystal display element.

Claims (11)

The diamine characterized by being represented by the following formula (1).
[Formula 1]

(In the formula, A represents an organic group that can be desorbed by heat selected from benzyloxycarbonyl group, 9-fluorenylmethyloxycarbonyl group, allyloxycarbonyl group and tert-butoxycarbonyl group. B is -CH ₂ -,- Represents O-, -S-, or -NH- X represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, an unsaturated hydrocarbon group, an aromatic hydrocarbon group or a heterocycle Y is a single bond, -O- , -CONH-, -NHCO-, -OCO-, -COO-, -HN-CO-NH-, -NHCOO-, or -OCONH- Z represents a single bond or an alkylene group having 1 to 2 carbon atoms. R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms R ² represents a -NH-A group when Y is -CONH- or -OCO-, and otherwise, a hydrogen atom, a halogen atom or a C 1 Represents an alkyl group of to 5. k1 represents an integer of 0 to 3, R ³ represents a halogen atom or an alkyl group having 1 to 5 carbon atoms, and -(R ³ ) _k1 represents that there are k1 substituents R ^{3, provided that} , when k1 is 2 or more, two or more R ³ may be the same or different, respectively, k2 represents an integer of 0 to 3, R ⁴ is a halogen atom or an alkyl group, and -(R ⁴ ) _k2 is a substituent R ⁴ is k2 However, when k2 is 2 or more, two or more R ⁴ may be the same or different, respectively.) The method of claim 1,
A diamine, characterized in that A is a tert-butoxycarbonyl group. The method of claim 1,
Diamine, characterized in that B is -NH-. The method of claim 1,
X represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, an unsaturated hydrocarbon group, an aromatic hydrocarbon group or a heterocycle, and Y represents a single bond, -O-, -OCO- or -COO-. Diamine. The method of claim 1,
X represents a divalent C1-C20 saturated hydrocarbon group, an unsaturated hydrocarbon group, an aromatic hydrocarbon group or a heterocycle, Y represents -CONH- (however, C=O is bonded to X), and R ^{2 represents} -NH-A group, characterized in that the diamine. Polyamide, polyamic acid, polyamic acid ester, or the polyamic acid and/or polyamic acid ester obtained by using a diamine component containing a diamine represented by formula (1) according to any one of claims 1 to 5 A polymer comprising a polyimide obtained by imidizing The method of claim 6,
A polymer, wherein the diamine component contains 5 to 100 mol% of a diamine represented by formula (1). The method of claim 6,
The polymer characterized in that the diamine component contains 5 to 50 mol% of a diamine represented by the following formula (2).
[Formula 2]

(In the formula, P ¹ is a single bond, -O-, -CH ₂ O-, -CONH-, -NHCO-, -OCO-, -COO-, -HN-CO-NH-, -NHCOO- or OCONH- , Q ¹ , Q ² , Q ³ each independently represent a divalent benzene ring or a cyclohexane ring, p, q, and r each independently represent an integer of 0 or 1, and P ² is a hydrogen atom, carbon number An organic group having 1 to 22 alkyl groups or a substituent consisting of an alkyl group in the steroid skeleton and having a total carbon number of 9 to 25 of the alkyl group is shown.) A liquid crystal aligning agent containing the polymer according to claim 6. A liquid crystal aligning film which uses the liquid crystal aligning agent of Claim 9. A liquid crystal display device comprising the liquid crystal aligning film according to claim 10.