JPWO2013115228A1 - Novel diamine, polymer, liquid crystal aligning agent, liquid crystal aligning film, and liquid crystal display device using the same - Google Patents

Abstract

A polymer comprising a polyamide obtained by using a diamine represented by the following general formula [1], a polyamic acid, a polyamic acid ester, or a polyimide obtained by dehydrating and ring-closing (imidizing) the polyamic acid and / or the polyamic acid ester . [In the formula, A represents an organic group that can be removed by heat. There are n (n = 1 or 2) NHA groups, and they are located in the ortho position with respect to the amino group (NH2 group). The amino groups are present at the meta position or the para position.)

Description

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

  In the liquid crystal display element, the liquid crystal alignment film plays a role of aligning the liquid crystal in a certain direction. Currently, the main liquid crystal alignment films used industrially are formed by applying a polyimide liquid crystal aligning agent made of a polyimide precursor, polyamic acid (also called polyamic acid) or a polyimide solution, onto a substrate. It is produced by doing. When the liquid crystal is aligned in parallel or inclined with respect to the substrate surface, a surface stretching process is further performed by rubbing after film formation. As an alternative to the rubbing treatment, a method using an anisotropic photochemical reaction by irradiation with polarized ultraviolet rays has been proposed, and in recent years, studies for industrialization have been performed.

  In order to improve the display characteristics of liquid crystal display elements, the structure of the polyamic acid and polyimide is changed and optimized, blending resins with different characteristics, and adding additives to improve liquid crystal alignment. Many technologies have been proposed for improving the display characteristics by controlling the pretilt angle and improving the electrical characteristics. For example, in order to obtain a high voltage holding ratio, it has been proposed to use a polyimide resin having a specific repeating structure (see Patent Document 1). Further, it has been proposed to shorten the time until the afterimage is erased by using soluble polyimide having a nitrogen atom in addition to the imide group for the afterimage phenomenon (see Patent Document 2 and the like).

  However, the performance of liquid crystal display elements has increased, the area has been increased, and the power consumption of display devices has progressed. In addition, the liquid crystal display elements can be used in various environments, and the characteristics required for liquid crystal alignment films are severe. It has become a thing. In particular, when a liquid crystal aligning agent is applied to a substrate, printing failure due to deposition and separation due to a long tact time, increase in ion density due to long-term use of liquid crystal display elements, burn-in due to accumulated charges, etc. This problem is a problem, and it is difficult to solve both of these problems simultaneously with the conventional technology.

  Therefore, a liquid crystal aligning agent using a diamine containing an alkylamine protected with a t-butoxycarbonyl group (hereinafter referred to as a Boc group) has been proposed (see Patent Document 3). In this technique, a polyimide precursor or a polyimide coating film having a primary or secondary aliphatic amine protected with a Boc group is formed, and then a primary or secondary aliphatic amine having high reactivity during firing. To generate a polyimide film having excellent mechanical strength.

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

JP-A-2-287324 JP-A-10-104633 WO2006-126555

  In view of the above circumstances, the present invention provides a liquid crystal aligning agent having good printability on a substrate, is excellent in rubbing resistance and liquid crystal orientation, does not accumulate RDC, and has a long-term high-temperature / high-humidity test. An object of the present invention is to provide a liquid crystal alignment film in which the characteristics of the liquid crystal display element are hardly deteriorated even in backlight irradiation. That is, the present invention provides a polyamide, a polyimide precursor, and a diamine capable of obtaining a polyimide having such characteristics, and further provides a liquid crystal aligning agent using the same, and a liquid crystal display element that hardly causes a decrease in contrast and image sticking. For the purpose.

  The present invention has been made in view of the above circumstances, and the problem is that the liquid crystal aligning agent has good printability (solubility of the polymer in a solvent), excellent rubbing resistance, and good liquid crystal alignment. A liquid crystal display element having the liquid crystal alignment film, in which RDC is difficult to accumulate and the voltage holding ratio is not easily lowered even under light irradiation conditions such as a high temperature environment or a backlight for a long time, and the liquid crystal alignment film. It is in providing the liquid crystal aligning agent for forming.

  As a result of diligent research, the inventor of the present invention has used polyamide, polyamic acid, and / or the diamine component containing a diamine compound containing a functional group that generates an amino group by heating (hereinafter also referred to as a specific diamine compound) as the diamine component. The present inventors have found that a liquid crystal aligning agent containing a polyimide obtained by imidizing a polyamic acid is extremely effective for achieving the above object, and has completed the present invention. In addition, the said specific diamine compound contains the novel compound which literature has not been described.

That is, the present invention has the following gist.
1. A polymer comprising a polyamide, a polyamic acid, a polyamic acid ester obtained by using the diamine represented by the following formula [1], or a polyimide obtained by dehydrating and ring-closing (imidizing) the polyamic acid and / or the polyamic acid ester.

（式中Ａは熱によって脱離し得る有機基を表す。ＮＨＡ基はｎ個（ｎ＝１又は２）具備し、アミノ基（ＮＨ_２基）に対してオルト位に存在する。また、アミノ基同士はメタ位又はパラ位に存在する。）
好ましくは、ＮＨＡ基は１個であり、この場合には下記式１ａで表される。

(In the formula, A represents an organic group that can be removed by heat. The NHA group has n (n = 1 or 2), and exists in the ortho position with respect to the amino group (NH ₂ group). They are in meta or para position.)
Preferably, there is one NHA group, and in this case, it is represented by the following formula 1a.

2. In the formula [1], the organic group A is preferably a tert-butoxycarbonyl group.

3. Polyamide, polyamic acid, polyamic acid ester, or polyamic acid and / or polyamic acid ester containing the diamine of the general formula [1] or [1a] described in 5-95 mol% The polymer which consists of a polyimide obtained by this.

4). The polyamide, the polyamic acid, the polyamic acid ester, or the polyamic acid according to any one of 1 to 3, which contains 5 to 50 mol% of a diamine containing a side chain represented by the following formula [2] And / or a polymer comprising a polyimide obtained by dehydrating and ring-closing (imidizing) a polyamic acid ester.

（式中、Ｒ^１は単結合、二価の有機基を表し、Ｘ^１、Ｘ^２、Ｘ^３はそれぞれ独立してベンゼン環又はシクロヘキサン環を表し、ｐ，ｑ，ｒはそれぞれ独立して０又は１の整数を表し、Ｒ^２は、水素原子、炭素数１〜２２のアルキル基又はステロイド骨格を有する炭素数１２〜２５である２価の有機基を表す。）

(In the formula, R ¹ represents a single bond or a divalent organic group, X ¹ , X ² , and X ³ each independently represent a benzene ring or a cyclohexane ring, and p, q, and r each independently represents 0. Or an integer of 1 and R ² represents a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or a divalent organic group having 12 to 25 carbon atoms having a steroid skeleton.)

5. A liquid crystal aligning agent comprising the polymer (polymer) described in any one of 5.1 to 4.

A liquid crystal alignment film using the liquid crystal aligning agent according to 6.5.

A liquid crystal display device comprising the liquid crystal alignment film according to 7.6.

8). A diamine compound represented by the following general formula [1-5] or [1-6].

  Since the liquid crystal aligning agent of this invention contains the polymer using the diamine compound of a specific structure, printability (solubility to a solvent of a polymer) is favorable. In addition, the liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention is rubbed because an amino group from which a protective group derived from a diamine compound having a specific structure has been reacted reacts to form a cyclized structure during coating baking. Excellent resistance and liquid crystal orientation, RDC is difficult to accumulate, and voltage retention is not likely to decrease even under light irradiation conditions such as a high temperature environment or a backlight for a long time. A liquid crystal display element having a liquid crystal alignment film can be provided.

  In the present invention, the polyamic acid obtained by the reaction of a diamine component containing a specific diamine compound and tetracarboxylic dianhydride and the polyimide obtained by dehydrating and ring-closing the polyamic acid are collectively referred to as a polymer. is there.

  The polymer of the present invention is obtained using a diamine compound represented by the following formula [1].

（式中Ａは熱によって脱離し得る有機基を表す。ＮＨＡ基はｎ個（ｎ＝１又は２）具備し、アミノ基（ＮＨ_２基）に対してオルト位に存在する。また、アミノ基同士はメタ位又はパラ位に存在する。）
好ましくは、ＮＨＡ基は１個であり、この場合には下記式１ａで表される。

(In the formula, A represents an organic group that can be removed by heat. The NHA group has n (n = 1 or 2), and exists in the ortho position with respect to the amino group (NH ₂ group). They are in meta or para position.)
Preferably, there is one NHA group, and in this case, it is represented by the following formula 1a.

式[１]におけるアミノ基の位置は特に限定されず、ジアミンであれば特に限定されず、例えば、下記式［１−１］〜［１−４］などが例示できるが、液晶配向性や合成のし易さの観点から、式[１−２]、［１−３］で表される構造になるような位置が好ましい。

The position of the amino group in the formula [1] is not particularly limited, and is not particularly limited as long as it is a diamine. For example, the following formulas [1-1] to [1-4] can be exemplified, but liquid crystal alignment and synthesis From the viewpoint of ease of handling, a position where a structure represented by Formulas [1-2] and [1-3] is obtained is preferable.

（式中Ａは熱によって脱離し得る有機基を表す。）
式[１]中、アミノ基が置換されるベンゼン環には有機基が置換されていてもよく、試薬の入手性などにより種々選択されるが、特に好ましくは未置換のものが好ましい。

(In the formula, A represents an organic group that can be removed by heat.)
In the formula [1], the benzene ring in which the amino group is substituted may be substituted with an organic group, and various selections are made depending on the availability of reagents, but an unsubstituted one is particularly preferable.

  The organic group A that can be eliminated by heat in the formula [1] is not particularly limited as long as it is an organic group that decomposes by heat and is eliminated and converted into an amino group. Of course, in the state of having A, the reactivity of the amino group is lowered. Examples of the structure of A that can be removed by heat include carbamate-based organic groups represented by benzyloxycarbonyl group, 9-fluorenylmethyloxycarbonyl group, allyloxycarbonyl group, tertiary butoxycarbonyl group, and the like. The tertiary butoxycarbonyl group is particularly preferred from the viewpoint of good heat desorption efficiency, desorption at a relatively low temperature, and discharge as a harmless gas upon desorption.

<Diamine compound>
A particularly preferred structure is a diamine compound represented by the following formula, which is a novel compound.

  Hereinafter, the effects of the novel diamine compound of the present invention will be described as examples. However, since it is clear that the diamine compound used in the present invention represented by the above formula [1] also exhibits the same effects, the overlapping description Is omitted.

  The diamine compound of the present invention is characterized by having an aromatic amino group protected with a tertiary butoxycarbonyl group (hereinafter referred to as a Boc group) adjacent to (in the ortho position) other amino groups. Usually, an amino group is a highly reactive organic group, so it is difficult to apply as it is as a part of the side chain of a diamine, but by protecting with a Boc group, the reactivity of the amino group may be reduced. In addition, when the amino group protected with the Boc group is heated at about 150 ° C. or higher, the Boc group is deprotected and can be converted into an amino group. In addition, since the Boc group has a bulky tertiary butyl group, the solubility of the monomer can be improved, and in addition, the polymer produced by using the monomer can also improve the solubility. .

  An 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, if a Boc-protected amino group is placed close to a carbonyl-containing linking group such as an amide bond or an ester bond as shown in the figure below, the reaction is likely to occur within the molecule rather than between the molecules. For example, by applying the diamine of the present invention to polyamide, polybenzimidazole can be derived [scheme-1], and by applying to polyamic acid or polyimide, for example, polybenzimidazole derivatives having a carboxylic acid moiety And a polyimide having an amino group, and a polymer [scheme-2] having a ring structure such as (1H-benzo [d] pyrrolo [1,2-a] imidazol-1-one) through further dehydration reaction therefrom. You will be able to guide.

  The diamine compound of the present invention is generated, for example, by reacting with tetracarboxylic dianhydride to form a polyimide precursor or a polyimide coating film having an amine protected with a Boc group, and the Boc group is eliminated by firing. It is characterized in that a heterocyclic ring is formed by reacting an amino group in the molecule. It should be noted that not all of the amino groups from which the Boc group is removed are consumed for the cyclization reaction, and a part of the amino group is also consumed for the intermolecular reaction (that is, the crosslinking reaction).

  It is considered that the reaction of the amino group generated by the elimination of the Boc group contributes to the improvement of the film strength and the reliability by crosslinking with the low molecular component in the polymer. Based on that, polyamic acid or polyimide using the diamine of the present invention is less likely to be scraped during rubbing treatment, and it is possible to obtain an effect that the voltage holding ratio is less likely to be lowered even when exposed to a high temperature or backlight for a long period of time. I know.

  In addition, since the bulky Boc group is removed at a relatively low temperature, the liquid crystal orientation also changes to a favorable structure, so that both rubbing resistance and liquid crystal orientation can be achieved. In addition, since the structure (heterocycle) generated by firing becomes an electrochemically active structure, it is considered that it contributes to the reduction of RDC. In particular, when an aromatic tetracarboxylic dianhydride and the diamine of the present invention are combined, it is considered that the mutual interaction strongly occurs, whereby an alignment film that is very difficult to accumulate RDC can be obtained.

<Synthesis Method of Diamine Compound>
Below, the main synthesis methods of the diamine of this invention are demonstrated. The method described below is a synthesis example and is not limited to this.

  The diamine of the present invention can be obtained by synthesizing a dinitro compound through each step and converting the nitro group into an amino group by a commonly used reduction reaction.

  In the synthesis of dinitro compounds, specific synthesis methods are shown in the examples, but dinitroaminobenzene derivatives in which the nitro group and amino group are close to each other and mononitrodiaminobenzene in which amino groups are close to each other Examples include a method of reacting a protective reagent capable of thermal deprotection such as tertiary butyl.

  The above reaction can be carried out in the presence of a base as necessary. The base to be used is not particularly limited as long as it can be synthesized. However, potassium carbonate, sodium carbonate, cesium carbonate, sodium alkoxide, potassium alkoxide, sodium hydroxide, potassium hydroxide, sodium hydride and other inorganic bases, pyridine, dimethylamino Examples thereof include organic bases such as pyridine, trimethylamine, triethylamine, and tributylamine. On the other hand, depending on the base used, two protecting groups may be substituted for one amino group, so it is necessary to select a base as appropriate. A base such as sodium hydride is preferable because it can efficiently extract hydrogen of the amino group, but synthesis is not particularly limited because synthesis is possible by other methods.

  The method for reducing the dinitro compound is not particularly limited. Usually, palladium-carbon, platinum oxide, Raney nickel, platinum black, rhodium-alumina, platinum sulfide carbon, etc. are used as a catalyst, ethyl acetate, toluene, tetrahydrofuran, dioxane, There is a method of performing reduction with hydrogen gas, hydrazine, hydrogen chloride, or the like in an alcohol-based solvent. You may use an autoclave etc. as needed. On the other hand, when an unsaturated bond site is included in the structure, if palladium carbon or platinum carbon is used, the unsaturated bond site may be reduced, resulting in a saturated bond. Reduction conditions using a transition metal such as tin or tin chloride as a catalyst are preferred.

<Diamine Represented by Formula [2]>
The polymer of the present invention can use a diamine represented by the following formula [2] in addition to the diamine compound represented by the above formula [1].

In the above formula [2], R ¹ , X ¹ , X ² , X ³ , p, q, r and R ² are as defined above. The diamine of the above formula [2] contributes to increasing the pretilt angle of the liquid crystal (the tilt angle of the liquid crystal with respect to the liquid crystal alignment film). Examples of these diamines include long-chain alkyl groups, perfluoroalkyl groups, A diamine having an aromatic cyclic group, an aliphatic cyclic group, a substituent combining these, a steroid skeleton group, or the like is preferable.

  Although the preferred magnitude of the pretilt angle varies depending on the mode, a preferred pretilt angle can be obtained by variously selecting the structure and amount of the diamine.

  In the side chain diamine represented by the formula [2], the tilting ability is compared in the TN mode in which a relatively low pretilt angle of 3 to 5 ° is required and the OCB mode in which a pretilt of 8 to 20 ° is required. Low side chain-containing diamines are preferred.

As a structure having a relatively small ability to develop tilt, R ¹ is preferably —O— or —NHCO— (—CONH—), wherein p is 0 to 1, q is 0 to 1, and r is preferably 0. When p and / or q is 1, R ² is preferably a linear alkyl having 1 to 12 carbon atoms, and when p = q = r = 0, R ² is a linear alkyl group having 10 to 22 carbon atoms or a steroid. A divalent organic group selected from organic groups having 12 to 25 carbon atoms having a skeleton is preferable. Specific structures of the side chain diamine having a small tilting ability are shown in Table 1, but are not limited thereto.

  From the viewpoint of electrical characteristics, long-chain alkyl side chains such as [2-1] to [2-3] in Table 1 are preferable, and [2-25] in Table 1 from the viewpoint of liquid crystal orientation and pretilt stability. The diamine represented by-[2-27] is preferable. In particular, the diamine represented by [2-25] is preferably used in combination with the diamine represented by the formula [A] because a liquid crystal aligning agent having excellent in-plane uniformity of the pretilt angle can be obtained.

On the other hand, in the VA mode and the like, vertical alignment can be obtained by using a side chain having a large tilting ability. As a preferable structure of the formula [2] in the VA mode, in the formula, R ¹ is preferably —O—, —COO—, or —CH ₂ O—, p is 0 to 1, q is 0 to 1, and r is 0-1 are preferred, ^{R 2} is preferably 2 to 22. In the case of p = q = r = 0, R ² is preferably a linear alkyl group having 18 to 22 carbon atoms or a divalent organic group that is an organic group having 12 to 25 carbon atoms having a steroid skeleton. Specific structures of side chain diamines having a large tilting ability are shown in Tables 2-1 and 2-2.

  These diamines have high tilting ability and are preferred when used in the VA mode. In particular, diamines such as [2-43] and [2-92] are preferable because they have a high ability to develop a tilt and exhibit vertical alignment with a relatively small amount of side chains, and particularly [2-52] and [2-101]. This diamine is preferable in terms of the printability of the aligning agent because it has a very high ability to develop tilt and can obtain vertical alignment with a very small amount of side chain.

On the other hand, in the diamine represented by the formula [2], R ¹ is preferably —NHCO—, and R ² is preferably an alkyl group having 1 to 16 carbon atoms, preferably 3 to 10 carbon atoms. In addition, X ¹ , X ² , X ³ and p, q, and r are appropriately combined. In such a diamine structure, 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.

  Examples of the diamine represented by the above formula [2] include a diamine represented by the following formula [3].

（式［３］中、ｎは０〜２１の整数であり、好ましくは０〜１５の整数である。）
上記式［３］で表されるジアミンの好ましい具体例を挙げるが、これに限定されるものではない。

(In Formula [3], n is an integer of 0-21, Preferably it is an integer of 0-15.)
Although the preferable specific example of the diamine represented by the said Formula [3] is given, it is not limited to this.

  Here, n is an integer of 0-19. When n is small, the pretilt angle does not appear, and when n is large, the solubility of the soluble polyimide decreases. Therefore, a preferable n range is 2-15, More preferably, it is 4-10.

  The content of the diamine represented by the above [2] is preferably 5 to 60 mol% in the total amine 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 diamine represented by Formula [1], More preferably, the diamine represented by Formula [2] is 0.3-1. 0.0 mole. When the diamine of the formula [2] is within this range, an appropriate pretilt angle can be obtained and good orientation can be obtained.

  In the diamine component, the formulas [1] and [2] may be only these, but other diamines may be used in combination. Although it does not specifically limit as another diamine in that case, The diamine used for manufacture of the polyamic acid used in mixture with the soluble polyimide mentioned later is mentioned.

  In addition, the tetracarboxylic dianhydride component used for producing a soluble polyimide by reacting with a diamine is also used for producing a polyamic acid used by mixing with a soluble polyimide described later. Anhydrides are mentioned.

  Although the molecular weight of the soluble polyimide contained in the liquid crystal aligning agent of the present invention is not particularly limited, from the viewpoint of the strength of the coating film and the ease of handling as the liquid crystal aligning agent, the weight average molecular weight is 2,000 to 200,000. Is more preferable, and it is 5,000 to 50,000.

[Polyamide, polyamic acid, polyamic acid ester, polyimide]
In the polyamide of the present invention, the diamine component containing the diamine compound represented by the formula [1] is reacted with a dicarboxylic acid halide in the presence of a base, or the dicarboxylic acid and the diamine are reacted in the presence of a suitable condensing agent and a base. It is a polyamide obtained by making it react. A polyamic acid is a polyamic acid obtained by reaction of a diamine component containing a diamine compound represented by the formula [1] and tetracarboxylic dianhydride. The polyamic acid ester of the present invention is obtained by reacting a diamine component containing the diamine represented by the formula [1] with a tetracarboxylic acid diester dichloride in the presence of a base, or reacting a tetracarboxylic acid diester and a diamine with a suitable condensing agent or base. It is a polyamic acid ester obtained by reacting in the presence. The polyimide of the present invention is a polyimide obtained by dehydrating and ring-closing this polyamic acid or by heating and ring-closing the polyamic acid ester. Any of such polyamide, polyamic acid, polyamic acid ester, and polyimide is useful as a polymer for obtaining a liquid crystal alignment film.

  In the diamine component (hereinafter also referred to as diamine component) for obtaining the polyamide, polyamic acid, polyamic acid ester, and polyimide, there is no limitation on the content ratio of the diamine represented by the formula [1].

  In the diamine component, when the diamine represented by the formula [1] is less than 100 mol%, the diamine other than the diamine represented by the formula [1] used is not particularly limited. The following is a specific example.

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

  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'-diamy Stilbene, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfone, 3,3′-diaminodiphenyl sulfone, 4,4′- Diaminobenzophenone, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 3,5-bis (4- Aminophenoxy) benzoic acid, 4,4′-bis (4-aminophenoxy) bibenzyl, 2,2-bis [(4-aminophenoxy) methyl] propane, 2,2-bis [4- (4-aminophenoxy) Phenyl] hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, [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) hexafluoropropane, 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-amino Enyl) tetramethyldisiloxane, benzidine, 2,2′-dimethylbenzidine, 1,2-bis (4-aminophenyl) ethane, 1,3-bis (4-aminophenyl) propane, 1,4-bis (4 -Aminophenyl) butane, 1,5-bis (4-aminophenyl) pentane, 1,6-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-dioate, 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-bi [4- (4-aminophenoxy) phenoxy] butane, 1,5-bis [4- (4-aminophenoxy) phenoxy] pentane, 1,6-bis [4- (4-aminophenoxy) phenoxy] hexane, , 7-bis [4- (4-aminophenoxy) phenoxy] heptane, 1,8-bis [4- (4-aminophenoxy) phenoxy] octane, 1,9-bis [4- (4-aminophenoxy) phenoxy Nonane, 1,10-bis [4- (4-aminophenoxy) phenoxy] decane, and the like.

  Examples of aromatic-aliphatic diamines include 3-aminobenzylamine, 4-aminobenzylamine, 3-amino-N-methylbenzylamine, 4-amino-N-methylbenzylamine, 3-aminophenethylamine, 4- Aminophenethylamine, 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-methyl) Aminobutyl) aniline, 3- (5-aminopentyl) aniline, 4- (5-aminopentyl) Niline, 3- (5-methylaminopentyl) aniline, 4- (5-methylaminopentyl) aniline, 2- (6-aminonaphthyl) methylamine, 3- (6-aminonaphthyl) methylamine, 2- (6 -Aminonaphthyl) ethylamine, 3- (6-aminonaphthyl) ethylamine and the like.

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

  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-diamino Examples include dodecane, 1,18-diaminooctadecane, and 1,2-bis (3-aminopropoxy) ethane.

  You may use together the diamine compound which has an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a heterocyclic ring, and the macrocyclic substituent which consists of them in a side chain. Specifically, the diamine compound shown by the following formula [DA-1]-a formula [DA-30] can be illustrated.

（式［ＤＡ-１］から式［ＤＡ-５］中、Ｒ_６は、炭素数１〜２２のアルキル基又はフッ素含有アルキル基である。）

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

（式［ＤＡ-６］から式［ＤＡ-９］中、Ｓ_５は、−ＣＯＯ−、−ＯＣＯ−、−ＣＯＮＨ−、−ＮＨＣＯ−、−ＣＨ_２−、−Ｏ−、−ＣＯ−、又は−ＮＨ−を示し、Ｒ_６は炭素数１〜２２のアルキル基又はフッ素含有アルキル基を示す。）

(In formula [DA-6] to formula [DA-9], S ₅ represents —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, —O—, —CO—, or —NH— represents R ₆ represents an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group.

（式［ＤＡ-１０］及び式［ＤＡ-１１］中、Ｓ_６は、−Ｏ−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＣＯＯＣＨ_２−、又は−ＣＨ_２ＯＣＯ−を示し、Ｒ_７は炭素数１〜２２のアルキル基、アルコキシ基、フッ素含有アルキル基又はフッ素含有アルコキシ基である。）

(In Formula [DA-10] and Formula [DA-11], S ₆ represents —O—, —OCH ₂ —, —CH ₂ O—, —COOCH ₂ —, or —CH ₂ OCO—, and R ₇ is an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group or a fluorine-containing alkoxy group.

（式［ＤＡ-１２］から式［ＤＡ-１４］中、Ｓ_７は、−ＣＯＯ−、−ＯＣＯ−、−ＣＯＮＨ−、−ＮＨＣＯ−、−ＣＯＯＣＨ_２−、−ＣＨ_２ＯＣＯ−、−ＣＨ_２Ｏ−、−ＯＣＨ_２−、又は−ＣＨ_２−を示し、Ｒ_８は炭素数１〜２２のアルキル基、アルコキシ基、フッ素含有アルキル基又はフッ素含有アルコキシ基である。）

(In the formulas [DA-12] to [DA-14], S ₇ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH _2. O—, —OCH ₂ —, or —CH ₂ — is represented, and R ₈ represents an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group, or a fluorine-containing alkoxy group.

（式［ＤＡ-１５］及び式［ＤＡ-１６］中、Ｓ_８は、−ＣＯＯ−、−ＯＣＯ−、−ＣＯＮＨ−、−ＮＨＣＯ−、−ＣＯＯＣＨ_２−、−ＣＨ_２ＯＣＯ−、−ＣＨ_２Ｏ−、−ＯＣＨ_２−、−ＣＨ_２−、−Ｏ−、又は−ＮＨ−を示し、Ｒ_９はフッ素基、シアノ基、トリフルオロメタン基、ニトロ基、アゾ基、ホルミル基、アセチル基、アセトキシ基、又は水酸基である。）

(In Formula [DA-15] and Formula [DA-16], S ₈ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH _2. O—, —OCH ₂ —, —CH ₂ —, —O—, or —NH—, wherein R ₉ is a fluorine group, cyano group, trifluoromethane group, nitro group, azo group, formyl group, acetyl group, acetoxy Group or hydroxyl group.)

（式［ＤＡ-１７］〜［ＤＡ-２０］中、Ｒ_１０は炭素数３〜１２のアルキル基であり、１，４−シクロへキシレンのシス−トランス異性は、それぞれトランス体である。）

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

  In the case of performing alignment treatment with light, it is preferable to use a diamine of the general formula [1] and a diamine of the above [DA-1] to [DA-30] in order to obtain a more stable pretilt. More preferable diamines that can be used in combination are those represented by the formulas [DA-10] to [DA-30], more preferably diamines of [DA-10] to [DA-16]. Although preferable content of these diamines is not particularly limited, 5 to 50 mol% is preferable, and 5 to 30 mol% is preferable from the viewpoint of printability.

  Moreover, you may use the following diamine together.

  In the formula [DA-35], m is an integer of 0 to 3, and in the formula [DA-38], n is an integer of 1 to 5. [DA-31] and [DA-32] are preferable because VHR can be improved by introducing them, and [DA-33] to [DA-38] are preferable because they are effective in reducing the storage charge.

  In addition, diaminosiloxanes represented by the following formula [DA-39] can also be exemplified.

（式［ＤＡ−３９］中、ｍは、１から１０の整数である。）

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

  Other diamine compounds may be used alone or in combination of two or more depending on properties such as liquid crystal alignment properties, voltage holding properties, and accumulated charges when the liquid crystal alignment film is formed.

  The tetracarboxylic dianhydride reacted with the diamine component to obtain the polyamic acid of the present invention is not particularly limited. Specific examples are given below.

  Examples of the tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutane. Tetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetra Carboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic Acid dianhydride, 3,4-dicarboxy-1-cyclohexyl succinic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, 1, , 3,4-Butanetetracarboxylic dianhydride, bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetra Carboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic dianhydride , Tricyclo [4.2.1.02,5] nonane-3,4,7,8-tetracarboxylic acid-3,4: 7,8-dianhydride, hexacyclo [6.6.0.12,7 .03, 6.19, 14.010, 13] hexadecane-4,5,11,12-tetracarboxylic acid-4,5: 11,12-dianhydride, 4- (2,5-dioxotetrahydrofuran- 3-yl) -1,2,3,4-tetrahydro Futaren 1,2-dicarboxylic anhydride and the like.

  Furthermore, when an aromatic tetracarboxylic dianhydride is used in addition to the tetracyclic dianhydride having the alicyclic structure or aliphatic structure, the liquid crystal alignment is improved and the accumulated charge of the liquid crystal cell is reduced. Since it can reduce, it is preferable. 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-benzophenonetetra Carboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride Products, 2,3,6,7-naphthalenetetracarboxylic dianhydride and the like.

  The tetracarboxylic acid dialkyl ester reacted with the diamine component to obtain the polyamic acid ester of the present invention is not particularly limited. Specific examples are given below.

  Specific examples of the 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-tetrahydrofurantetracarboxylic acid dialkyl ester, 1,2,4,5-cyclohexanetetracarboxylic acid dialkyl ester, 3,4-dicarboxy-1 -Cyclohexyl succinic acid dialkyl ester, 3,4-dicarboxy- , 2,3,4-Tetrahydro-1-naphthalene succinic 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′-dicyclohexyltetracarboxylic acid dialkyl ester, 2,3,5-tricarboxycyclopentylacetic acid dialkyl ester, cis-3,7-dibutylcycloocta-1,5- Diene-1,2,5,6-tetracarboxylic acid dialkyl ester, tricyclo [4.2.1.02,5] nonane-3,4,7,8-tetracarboxylic acid-3,4: 7,8- Dialkyl ester, hexacyclo [6.6.0.12,7.03,6.19,14.010,13] hexadecane-4,5,11, 2-tetracarboxylic acid-4,5: 11,12-dialkyl ester, 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic dialkyl Examples include esters.

  As the aromatic tetracarboxylic acid dialkyl ester, pyromellitic acid dialkyl ester, 3,3 ′, 4,4′-biphenyltetracarboxylic acid dialkyl ester, 2,2 ′, 3,3′-biphenyltetracarboxylic acid dialkyl ester, 2,3,3 ′, 4-biphenyltetracarboxylic acid dialkyl ester, 3,3 ′, 4,4′-benzophenone tetracarboxylic acid dialkyl ester, 2,3,3 ′, 4-benzophenone tetracarboxylic acid dialkyl ester, bis (3,4-dicarboxyphenyl) ether dialkyl ester, bis (3,4-dicarboxyphenyl) sulfone dialkyl ester, 1,2,5,6-naphthalene tetracarboxylic acid dialkyl ester, 2,3,6,7- Naphthalene tetracarboxylic acid dialkyl ester And the like.

  The dicarboxylic acid reacted with the diamine component to obtain the polyamide of the present invention is not particularly limited. Specific examples of the aliphatic dicarboxylic acid of dicarboxylic acid or its derivative include malonic acid, succinic acid, dimethylmalonic acid, succinic acid, fumaric acid, glutaric acid, adipic acid, muconic acid, 2-methyladipic acid, trimethyladipic acid, pimelin Mention may be made of dicarboxylic acids such as acids, 2,2-dimethylglutaric acid, 3,3-diethylsuccinic acid, azelaic acid, sebacic acid and suberic acid.

  Examples of the alicyclic dicarboxylic acid include 1,1-cyclopropanedicarboxylic acid, 1,2-cyclopropanedicarboxylic acid, 1,1-cyclobutanedicarboxylic acid, 1,2-cyclobutanedicarboxylic acid, and 1,3-cyclobutanedicarboxylic acid. 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 Acid, 1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,1-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexane Dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,4- (2-norbo Nene) dicarboxylic acid, norbornene-2,3-dicarboxylic acid, bicyclo [2.2.2] octane-1,4-dicarboxylic acid, bicyclo [2.2.2] octane-2,3-dicarboxylic acid, 2, 5-dioxo-1,4-bicyclo [2.2.2] octanedicarboxylic acid, 1,3-adamantane dicarboxylic acid, 4,8-dioxo-1,3-adamantane dicarboxylic acid, 2,6-spiro [3. 3] Heptanedicarboxylic acid, 1,3-adamantanediacetic acid, camphoric acid and the like.

  As aromatic dicarboxylic acids, o-phthalic acid, isophthalic acid, terephthalic acid, 5-methylisophthalic acid, 5-tert-butylisophthalic acid, 5-aminoisophthalic acid, 5-hydroxyisophthalic acid, 2,5-dimethylterephthalic acid Acid, tetramethylterephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-anthracenedicarboxylic acid, 1,4 -Anthraquinone dicarboxylic acid, 2,5-biphenyl dicarboxylic acid, 4,4'-biphenyl dicarboxylic acid, 1,5-biphenylene dicarboxylic acid, 4,4 "-terphenyl dicarboxylic acid, 4,4'-diphenylmethane dicarboxylic acid, 4,4'-diphenylethanedicarboxylic acid, 4,4'-diphenyl Rupropanedicarboxylic acid, 4,4'-diphenylhexafluoropropanedicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-bibenzyldicarboxylic acid, 4,4'-stilbene dicarboxylic acid, 4,4'- Transdicarboxylic acid, 4,4′-carbonyldibenzoic acid, 4,4′-sulfonyldibenzoic acid, 4,4′-dithiodibenzoic acid, p-phenylenediacetic acid, 3,3′-p-phenylenedipropion Acid, 4-carboxycinnamic acid, p-phenylenediacrylic acid, 3,3 ′-[4,4 ′-(methylenedi-p-phenylene)] dipropionic acid, 4,4 ′-[4,4 ′-( Oxydi-p-phenylene)] dipropionic acid, 4,4 ′-[4,4 ′-(oxydi-p-phenylene)] butyric acid, (isopropylidenedi-p-phenylenedioxy) Can be exemplified a two-butyric acid, bis (p- carboxyphenyl) dicarboxylic acids such as dimethyl silane.

  Examples of the dicarboxylic acid containing a heterocyclic ring include 1,5- (9-oxofluorene) dicarboxylic acid, 3,4-furandicarboxylic acid, 4,5-thiazole dicarboxylic acid, 2-phenyl-4,5-thiazole dicarboxylic 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, Examples thereof include 5-pyridinedicarboxylic acid, 2,6-pyridinedicarboxylic acid, 3,4-pyridinedicarboxylic acid, and 3,5-pyridinedicarboxylic acid.

  The various dicarboxylic acids may be acid dihalides or those having an anhydrous structure. These dicarboxylic acids are preferably dicarboxylic acids that can give a polyamide having a linear structure, from the viewpoint of maintaining the orientation of liquid crystal molecules. Among these, terephthalic acid, isoterephthalic acid, 1,4-cyclohexanedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, 4,4′-diphenylmethanedicarboxylic acid, 4,4′-diphenylethanedicarboxylic acid, 4,4 '-Diphenylpropanedicarboxylic acid, 4,4'-diphenylhexafluoropropanedicarboxylic acid, 2,2-bis (phenyl) propanedicarboxylic acid, 4,4 cast tert-phenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2 , 5-pyridinedicarboxylic acid or these acid dihalides are preferably used. Some of these compounds have isomers, but may be a mixture containing them. Two or more compounds may be used in combination. The dicarboxylic acids used in the present invention are not limited to the above exemplary compounds.

  Tetracarboxylic dianhydride can be used singly or in combination of two or more according to properties such as liquid crystal alignment properties, voltage holding properties, and accumulated charges when formed into a liquid crystal alignment film.

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

  The organic solvent used for the reaction between tetracarboxylic dianhydride and diamine is not particularly limited as long as the produced polyamic acid can be dissolved. Specific examples are given below.

  N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, tetramethyl urea, pyridine, dimethyl sulfone, hexamethyl sulfoxide , Γ-butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl Carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethyl 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, 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-ethoxypropion , 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 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 can be mentioned. These may be used alone or in combination. Further, even a solvent that does not dissolve the polyamic acid may be used by mixing with the above solvent as long as the produced polyamic acid does not precipitate.

  In addition, since water in the organic solvent inhibits the polymerization reaction and further causes hydrolysis of the produced polyamic acid, it is preferable to use a dehydrated and dried organic solvent as much as possible.

  When the tetracarboxylic dianhydride and the diamine component are reacted in an organic solvent, the solution in which the diamine component is dispersed or dissolved in the organic solvent is stirred, and the tetracarboxylic dianhydride is used as it is or in an organic solvent. A method of adding by dispersing or dissolving, a method of adding a diamine component to a solution in which tetracarboxylic dianhydride is dispersed or dissolved in an organic solvent, and alternately adding a tetracarboxylic dianhydride and a diamine component. Any of these methods may be used. In addition, when the tetracarboxylic dianhydride or diamine component is composed of a plurality of types of compounds, they may be reacted in a premixed state, may be individually reacted sequentially, or may be further reacted individually. May be mixed and reacted to form a high molecular weight product.

  The polymerization temperature at that time can be selected from an arbitrary temperature of -20 ° C to 150 ° C, preferably in the range of -5 ° C to 100 ° C. The reaction can be carried out at any concentration, but if the concentration is too low, it is 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 is difficult. Therefore, the total concentration of the tetracarboxylic dianhydride and the diamine component in the reaction solution is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The initial stage of the reaction is carried out at a high concentration, and then an organic solvent can be added.

  In the polyamic acid polymerization reaction, the ratio of the total number of moles of tetracarboxylic dianhydride to the total number of moles of the diamine component is preferably 0.8 to 1.2. Similar to the normal polycondensation reaction, the closer the molar ratio is to 1.0, the higher the molecular weight of the polyamic acid produced.

  The polyimide of the present invention is a polyimide obtained by dehydrating and ring-closing the above polyamic acid, and is useful as a polymer for obtaining a liquid crystal alignment film.

  In the polyimide of the present invention, the dehydration cyclization rate (imidation rate) of the amic acid group is not necessarily 100%, and can be arbitrarily adjusted according to the application and purpose.

[Polyimide]
Examples of the method for imidizing the polyamic acid include thermal imidization in which the polyamic acid solution is heated as it is, and catalytic imidization in which a catalyst is added to the polyamic acid solution.

  The temperature at which the polyamic acid is thermally imidized in the solution 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 from the system.

  Catalytic imidation of polyamic acid can be performed by adding a basic catalyst and an acid anhydride to a polyamic acid solution and stirring at -20 to 250 ° C, preferably 0 to 180 ° C. The amount of the basic catalyst is 0.5 to 30 mol times, preferably 2 to 20 mol times of the amic acid group, and the amount of the acid anhydride is 1 to 50 mol times, preferably 3 to 30 mol of the amido acid group. Is double. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Among them, pyridine is preferable because it has an appropriate basicity for proceeding with the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like. Among them, use of acetic anhydride is preferable because purification after completion of the reaction is facilitated. The imidization rate by catalytic imidation can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

[Polyamic acid ester]
As a method of synthesizing a polyamic acid ester, a reaction between a tetracarboxylic acid diester dichloride and a diamine, or a reaction between a tetracarboxylic acid diester and a diamine in the presence of an appropriate condensing agent and a base, a kind of polyimide precursor. The polyamic acid ester which is can be obtained. Alternatively, it can also be obtained by polymerizing a polyamic acid in advance and esterifying the carboxylic acid in the amic acid using a polymer reaction.

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

  As the base, pyridine, triethylamine, and 4-dimethylaminopyridine can be used, but pyridine is preferable because the reaction proceeds gently. The addition amount of the base is preferably 2 to 4 times the molar amount of the tetracarboxylic acid diester dichloride from the viewpoint of easy removal and high molecular weight.

  When performing condensation polymerization in the presence of a condensing agent, triphenyl phosphite, dicyclohexylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, N, N′-carbonyldiimidazole, dimethoxy-1, 3,5-triazinylmethylmorpholinium, O- (benzotriazol-1-yl) -N, N, N ′, N′-tetramethyluronium tetrafluoroborate, O- (benzotriazole-1- Yl) -N, N, N ′, N′-tetramethyluronium hexafluorophosphate, (2,3-dihydro-2-thioxo-3-benzoxazolyl) phosphonate diphenyl, 4- (4,6 -Dimethoxy-1,3,5-triazin-2-yl) 4-methoxymorpholium chloride n-hydrate can be used The

  In the method 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 addition amount of the Lewis acid is preferably 0.1 to 1.0 times the molar amount relative to (C1).

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

[polyamide]
Polyamide can also be synthesized in the same manner as the polyamic acid ester.

[Recovery of polymer]
When recovering the produced polyamic acid, polyamic acid ester, and polyimide from the reaction solution of polyamic acid, polyamic acid ester, and polyimide, the reaction solution may be poured into a poor solvent and precipitated. Examples of the poor solvent used for precipitation include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, and water. The polymer precipitated in a poor solvent and collected by filtration can be dried by normal temperature or reduced pressure at room temperature or by heating. In addition, when the polymer recovered by precipitation is redissolved in an organic solvent and the operation of reprecipitation recovery 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 it is preferable to use three or more kinds of poor solvents selected from these because purification efficiency is further improved.

  The molecular weight of the polyamic acid and polyimide contained in the liquid crystal aligning agent of the present invention is determined by considering the strength of the coating film obtained therefrom, the workability during coating film formation, and the uniformity of the coating film. The weight average molecular weight measured by the Chromatography method is preferably 5,000 to 1,000,000, more preferably 10,000 to 150,000.

<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 which the resin component for forming a resin film melt | dissolved in the organic solvent. Here, the said resin component is a resin component containing at least 1 type of polymer chosen from the polymer of this invention mentioned above. In that case, the content of the resin component 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, the resin component may be a copolymer used in the present invention, or other polymer may be mixed with the polymer of the present invention. At that time, the content of the polymer other than the polymer of the present invention in the resin component is 0.5% by mass to 15% by mass, preferably 1% by mass to 10% by mass.

  Examples of such other polymers include polyamic acid or polyimide obtained by using a diamine compound other than the specific diamine compound as a diamine component to be reacted with the tetracarboxylic dianhydride component.

  The organic solvent used for the liquid crystal aligning agent of this invention will not be specifically limited if it is an organic solvent in which a resin component is dissolved. Specific examples are given below.

  N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethylsulfoxide, tetramethylurea, pyridine, Dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, 3-methoxy-N, N-dimethylpropanamide, 3-ethoxy-N, N-dimethylpropanamide, 3-butoxy-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, 4-hydroxy-4 Such as methyl-2-pentanone and the like. These may be used alone or in combination.

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

  Specific examples of the solvent (poor solvent) that improves the uniformity of the film thickness and the surface smoothness include the following.

  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 monoacetate Isopropyl 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, dipro Lenglycol 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 ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, Ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 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- Low 1-monoethyl 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 Examples include solvents having surface tension.

  These poor solvents may be used alone or in combination. When using the above 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%.

  Examples of compounds that improve film thickness uniformity and surface smoothness include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants.

  More specifically, for example, F-top EF301, EF303, EF352 (manufactured by Tochem Products), MegaFuck F171, F173, R-30 (manufactured by Dainippon Ink), Florard FC430, FC431 (manufactured by Sumitomo 3M) Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.). The use ratio 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.

  Specific examples of the compound that improves the adhesion between the liquid crystal alignment film and the substrate include the following functional silane-containing compounds and epoxy group-containing compounds.

  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-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxy Carbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-to Ethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltri Methoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-amino Propyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether , Polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetra Glycidyl-2,4-hexanediol, N, N, N ′, N ′,-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N Examples include ', N',-tetraglycidyl-4,4'-diaminodiphenylmethane.

  Furthermore, in addition to improving the adhesion between the substrate and the film, the following phenoplast type additives may be introduced for the purpose of preventing the deterioration of electrical characteristics due to the backlight. Specific phenoplast additives are shown below, but are not limited to this structure.

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

  In addition to the above, the liquid crystal aligning agent of the present invention has a dielectric or conductive material for the purpose of changing the electrical properties such as the dielectric constant and conductivity of the liquid crystal aligning film, as long as the effects of the present invention are not impaired. Further, a crosslinkable compound for the purpose of increasing the hardness and density of the liquid crystal alignment film may be added.

<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal aligning agent of the present invention can be used as a liquid crystal alignment film after being applied and baked on a substrate and then subjected to alignment treatment by rubbing treatment, light irradiation or the like, or without alignment treatment in vertical alignment applications. In this case, the substrate to be used is not particularly limited as long as it is a highly transparent substrate, 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 to use a substrate on which an ITO electrode or the like for driving liquid crystal is formed from the viewpoint of simplifying the process. Further, in the reflection type liquid crystal display element, an opaque material such as a silicon wafer can be used as long as the substrate is only on one side, and in this case, a material that reflects light such as aluminum can be used.

  The application method of the liquid crystal aligning agent is not particularly limited, but industrially, a method of screen printing, offset printing, flexographic printing, ink jet, or the like is common. Other coating methods include dip, roll coater, slit coater, spinner and the like, and these may be used depending on the purpose.

  Firing after applying the liquid crystal aligning agent on the substrate can be performed at 50 to 300 ° C., preferably 80 to 250 ° C. by a heating means such as a hot plate, and the solvent can be evaporated to form a coating film. If the thickness of the coating film formed after baking is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may be lowered. It is preferably 10 to 100 nm. When the liquid crystal is horizontally or tilted, the fired coating film is treated by rubbing or irradiation with polarized ultraviolet rays.

  The liquid crystal display element of the present invention is a liquid crystal display element obtained by obtaining a substrate with a liquid crystal alignment film from the liquid crystal aligning agent of the present invention by the method described above, and then preparing a liquid crystal cell by a known method.

  To give an example of liquid crystal cell production, prepare a pair of substrates on which a liquid crystal alignment film is formed, spray spacers on the liquid crystal alignment film of one substrate, and make the liquid crystal alignment film surface inside. Examples include a method of bonding the other substrate and injecting the liquid crystal under reduced pressure, or a method of sealing the liquid crystal after dropping the liquid crystal on the liquid crystal alignment film surface on which the spacers are dispersed, and the like. . The thickness of the spacer at this time is preferably 1 to 30 μm, more preferably 2 to 10 μm.

  As described above, the liquid crystal display element manufactured using the liquid crystal aligning agent of the present invention has excellent reliability and can be suitably used for a large-screen high-definition liquid crystal television.

<Example>
Hereinafter, the present invention will be described with reference to examples, but the present invention is of course not limited to these examples.

  The abbreviations of the compounds used in Examples and Comparative Examples are as follows.

  Table 3 shows a list of polyamic acids (PAA) synthesized in Examples and Comparative Examples, Table 4 shows a list of soluble polyimides (SPI) synthesized in Examples and Comparative Examples, and Table 5 shows The lists of polyamic acid esters (PAE) and polyamides synthesized in Examples and Comparative Examples are shown respectively.

  Further, Tables 6 and 7 show lists of liquid crystal alignment agents (AL) prepared in Examples and Comparative Examples, respectively, and Table 8 shows alignment agent printability of liquid crystal alignment agents in Examples and Comparative Examples. The evaluation results of rubbing resistance and cell display characteristics are shown, and Table 9 shows the evaluation results of liquid crystal cells using the liquid crystal aligning agents of Examples and Comparative Examples.

<Tetracarboxylic dianhydride>
A-1: 1,2,3,4-cyclobutanetetracarboxylic acid dihydrate A-2: pyromellitic acid dihydrate A-3: bicyclo [3,3,0] octane-2,4,6,8- Tetracarboxylic dianhydride A-4: 2,3,5-tricarboxycyclopentylacetic acid-1,4: 2,3-dianhydride A-5: 1,2,3,4-cyclobutanetetracarboxylic acid dimethyl ester A-6: Adipyl chloride A-7: Terephthaloyl chloride

<Diamine>
B-1: 1,4-phenylenediamine B-2: 3-aminobenzylamine B-3: 1,3-phenylenediamine

B-4: 4-Hexadecyloxy-1,3-diaminobenzene B-5: 4- (trans-4-pentylcyclohexyl) benzamide-2 ′, 4′-phenylenediamine B-6: 4- (trans-4 -Pentylcyclohexyl) phenoxy-2 ', 4'-phenylenediamine

B-7: 2,5-diamino tert-butoxycarbonylaminobenzene B-8: 2,4-diamino tert-butoxycarbonylaminobenzene

<Condensation agent>
DMT-MM: 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) 4-methoxymorpholium chloride n-hydrate

<Organic solvent>
NMP: N-methyl-2-pyrrolidone GBL: γ-butyrolactone BC: Butyl cellosolve THF: Tetrahydrofuran DMF: N, N-dimethylformamide

  Below, it shows about the evaluation method performed in the present Example.

<Measurement of molecular weight>
The molecular weight of the polyamic acid and the polyimide was measured with a GPC (normal temperature gel permeation chromatography) apparatus, and the number average molecular weight and the weight average molecular weight were calculated as polyethylene glycol and polyethylene oxide equivalent values.

GPC device: manufactured by Shodex (GPC-101)
Column: manufactured by Shodex (series of KD803 and KD805)
Column temperature: 50 ° C
Eluent: N, N-dimethylformamide (as additive, lithium bromide-hydrate (LiBr · H ₂ O) is 30 mmol / L, phosphoric acid / anhydrous crystal (o-phosphoric acid) is 30 mmol / L , Tetrahydrofuran (THF) at 10 ml / L)
Flow rate: 1.0 ml / min Standard sample for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight: about 900,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation, and polyethylene glycol manufactured by Polymer Laboratories ( Molecular weight about 12,000, 4,000, 1,000).

<Measurement of imidization ratio>
The imidation ratio of polyimide was measured as follows. 20 mg of the polyimide powder was put in an NMR sample tube, and 0.53 ml of deuterated dimethyl sulfoxide (DMSO-d ₆ , 0.05% TMS mixed product) was added and completely dissolved. 500 MHz proton NMR was measured for this solution with the NMR measuring device by the JEOL datum company (JNM-ECA500).

  The imidization rate was calculated by the following formula. In addition, the imidation ratio of the polyimide which does not use the diamine represented by the formula [1] was calculated by setting the value of “formula [1] diamine introduction amount during polyamic acid polymerization” in the following formula to zero.

Imidation rate (%) = (100-Polyamic acid polymerization formula [1] Amount of diamine introduced (mol%) × 1/2) × α

  In the formula, α represents a proton derived from a structure that does not change before and after imidation as a reference proton, and a peak integrated value of this proton and a proton peak derived from the NH group of an amic acid that appears in the vicinity of 9.5 to 10.0 ppm. It calculated | required by following Formula using the integrated value.

    α = (1−α · x / y)

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

<Production of liquid crystal cell>
A liquid crystal aligning agent is 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. The coating film was formed. This coating film surface is rubbed with a rubbing apparatus having a roll diameter of 120 mm using a cotton cloth (YA-25C, manufactured by Yoshikawa) under the conditions of a roll rotation speed of 1000 rpm, a roll traveling speed of 50 mm / sec, and an indentation amount of 0.4 mm. A substrate with a film was obtained.

  Two substrates are prepared, a 6 μm spacer is sprayed on the surface of the liquid crystal alignment film, and a sealant (NX-1500T manufactured by Sumitomo Chemical Co., Ltd.) is printed thereon with a seal dispenser. After the substrates were bonded so that the liquid crystal alignment film faces each other and the rubbing direction was perpendicular, the sealing agent was cured (temporary curing: 80 ° C. for 30 minutes, main curing: 150 ° C. for 1 hour) to produce an empty cell. . Liquid crystal MLC-2003 (Merck Japan Co., Ltd.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain a twisted nematic liquid crystal cell.

  Further, for evaluation of the liquid crystal alignment material for vertical alignment (VA mode), an empty cell was prepared by the above method without going through the rubbing process, and the liquid crystal was evaluated using MLC-6608.

<Varnish printability test>
The prepared liquid crystal aligning agent was subjected to flexographic printing on a cleaned Cr plate using an alignment film printing machine (“Nongstromer” manufactured by Nissha Printing Co., Ltd.), thereby performing an applicability test. About 1.0 mL of the liquid crystal aligning agent was dropped onto the anilox roll, and the blanking operation was performed 10 times. Then, 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, the coating film was temporarily dried, and the film state was observed. The observation was performed by visual observation and an optical microscope (“ECLIPSE ME600” manufactured by Nikon Corporation) at 50 times, and mainly the film thickness unevenness and the film thickness unevenness of the edge portion were observed.

<Measurement of pretilt angle>
A liquid crystal cell obtained in the same manner as in the above <Production of liquid crystal cell> was heated at 105 ° C. for 10 minutes and then used to measure the pretilt angle. For the measurement, an Axo Scan Mueller matrix polarimeter manufactured by Optometrics was used.

<Measurement of initial VHR (voltage holding ratio)>
A voltage of 1V is applied for 60 μs at a temperature of 60 ° C. to the twisted nematic liquid crystal cell manufactured by the method described in <Preparation of liquid crystal cell> above, and the voltage after 166.7 ms is measured. It was calculated as voltage holding ratio. For measuring the voltage holding ratio, a VHR-1 voltage holding ratio measuring device manufactured by Toyo Corporation was used.

<Backlight aging resistance>
The sample was left on a 40 inch liquid crystal TV backlight module for 240 hours and measured according to the same method as the above <Measurement of initial VHR (voltage holding ratio)>.

<High temperature and high humidity test>
Furthermore, it was left in a high-temperature and high-humidity device at a temperature of 70 ° C. and a humidity of 70% for 240 hours, and the measurement was performed according to the same method as the above <Measurement of initial VHR (voltage holding ratio)>.

<Measurement of RDC (residual DC voltage)>
A flicker at each voltage is applied to the twisted nematic liquid crystal cell manufactured by the method described in <Preparation of liquid crystal cell> by applying a DC voltage from 0 V to 1.0 V at a temperature of 23 ° C. Measurement was performed using an amplitude level photoelectric conversion device, and a calibration curve was created for the flicker amplitude level and applied voltage. After grounding the cell for 5 minutes and leaving it to stand, measure the flicker amplitude level immediately after applying the AC voltage to V50 (the voltage at which the luminance is halved), the DC voltage of 5.0 V for 1 hour, and the DC voltage only to 0 V, RDC was estimated by comparing with a calibration curve prepared in advance. (This RDC estimation method is called a flicker reference method.)

<Synthesis of diamine>
Example 1
Synthesis of 2,5-diamino tert-butoxycarbonylaminobenzene [B-7]

Step 1 Synthesis of 4-nitro 2-tert-butoxycarbonylaminoaniline Weigh 50.0 g (326.5 mmol) of 4-nitro-1,2-phenylenediamine in a 1 L four-necked flask, dissolve 500 ml of THF, and dissolve in a nitrogen atmosphere. To about 60 ° C., and 71.3 g (326.5 mmol) of tert-butyl dicarbonate was slowly added dropwise over 1 hour using a dropping funnel and refluxed for 4 hours.

  After completion of the reaction, the reaction solution was concentrated with a rotary evaporator and recrystallized with a mixed solvent of ethyl acetate: n-hexane (volume ratio 7: 3) to obtain 62.0 g (yield 75%) of an orange solid. It was.

Synthesis of Step 2 [B-7] In a 1 L four-necked flask, 60.0 g (236.9 mmol) of 2-tertbutoxycarbonylamino-5-nitroaniline and 6.0 g of 10 wt% palladium carbon were weighed, and 500 ml of THF was added. Vacuum degassing and hydrogen substitution were performed, and the reaction was allowed to proceed at room temperature for 24 hours.

After completion of the reaction, palladium carbon was removed with a PTFE membrane filter, the filtrate was concentrated with a rotary evaporator, and recrystallized with a mixed solvent of ethyl acetate and n-hexane (volume ratio 5: 5) to obtain the target diamine. As a result, 50.2 g (yield: 95%) of a light pink solid was obtained. The structure was confirmed by ¹ H-NMR spectrum which is a nuclear magnetic resonance spectrum of an intramolecular hydrogen atom. The measurement data is shown below.
¹ H NMR (400 MHz, [D ₆ ] -DMSO) δ: 6.91-6.89 (d, 1H), 6.12-6.09 (dd, 2H), 5.95 (s- br, 1H), 3.75 (s-br, 2H), 3.53 (s-br, 2H), 1.49 (s, 9H)

Example 2
Synthesis of 2,4-diamino-2-tert-butoxycarbonylaminobenzene [B-8]

Step 1 Synthesis of 2,4-dinitro tert-butoxycarbonylaminobenzene In a 1 L four-necked flask, 22.8 g (about 273.0 mmol) of sodium hydride (Pure: 50%) was measured, 500 ml of DMF was added, and nitrogen atmosphere was added. The solution was cooled to about 0 ° C., a DMF solution of 2,4-dinitroaniline 50.0 g (273.0 mmol) was slowly added dropwise and reacted for 1 hour, and 59.6 g (273.0 mmol) of tertbutyl dicarbonate was added to the dropping funnel. Was slowly added dropwise over 1 hour and reacted at room temperature for 2 hours.

  After completion of the reaction, 500 ml of ion-exchanged water is added and stirred for a while, so that a solid precipitates. The solid is collected by filtration, washed several times with methanol, and a mixed solvent of ethyl acetate and n-hexane (volume ratio 5: 5). ) To obtain 60.3 g (yield 78%) of a pale yellow solid.

Synthesis of Step 2 [B-8] In a 1 L four-necked flask, 60.0 g (211.8 mmol) of 2,4-dinitro tertbutoxycarbonylaminobenzene and 6.0 g of 10 wt% palladium carbon were weighed, 500 ml of THF was added, and the pressure was reduced. Deaeration and hydrogen replacement were performed, and the reaction was allowed to proceed at room temperature for 24 hours.

After completion of the reaction, palladium carbon was removed with a PTFE membrane filter, the filtrate was concentrated with a rotary evaporator, and recrystallized with a mixed solvent of ethyl acetate and n-hexane (volume ratio 3: 7) to obtain the desired diamine. As a result, 45.9 g (yield: 97%) of a milky white solid was obtained. The structure was confirmed by ¹ H-NMR spectrum which is a nuclear magnetic resonance spectrum of an intramolecular hydrogen atom. The measurement data is shown below.
¹ H NMR (400 MHz, [D ₆ ] -DMSO) δ: 7.07 (s-br, 1H), 6.68 (d, 1H), 6.67-6.63 (dd, 1H) 6.35-6.32 (dd, 1H), 3.42 (s-br, 2H), 3.12 (s-br, 2H), 1.50 (s, 9H)

Example 3
Polymerization of polyamic acid [PAA-1: A-1 / B-7] and preparation of alignment agent [AL-1] In a 50 ml four-necked flask equipped with a nitrogen introduction tube and a mechanical stirrer, 3.35 g of B-7 ( 15.00 mmol), 34.8 g of NMP was added and dissolved, cooled to about 10 ° C. under a nitrogen atmosphere, 2.85 g (14.60 mmol) of A-1 was added little by little, returned to room temperature, and reacted for 6 hours. And a 15% by mass polyamic acid solution [PAA-1] was obtained.
The obtained PAA-1 had a number average molecular weight of 11,300 and a weight average molecular weight of 24,500.

  10.0 g of this polyamic acid solution was weighed into a 50 ml Erlenmeyer flask equipped with a stir bar, 7.5 g of NMP and 7.5 g of BCS were added, and the mixture was stirred at room temperature for 30 minutes. %, 64% by mass of NMP and 30% by mass of BCS were obtained [AL-1].

Example 4
Synthesis of Soluble Polyimide [SPI-1: A-1 / B-7] and Preparation of Orientation Agent [AL-2] The polyamic acid solution [PAA-] obtained in Example 3 was added to a 100 ml Erlenmeyer flask equipped with a stirrer. 1] was measured, 34.3 g of NMP was added, 3.32 g of acetic anhydride and 1.37 g of pyridine were added, and the mixture was stirred at room temperature for 30 minutes and then stirred at 50 ° C. for 3 hours for reaction. After the completion of the reaction, the polymer was precipitated slowly into 240 ml of methanol, stirred for 30 minutes, and then a solid was collected by filtration. The obtained solid was sufficiently washed with methanol, and then vacuum-dried at 100 ° C. to obtain polyimide [SPI-1]. The number average molecular weight of this polyimide was 10,300, the weight average molecular weight was 22,600, and the imidation ratio was 82%.

  Measure 2.00 g of SPI-1 in a 50 ml Erlenmeyer flask equipped with a stir bar, add 18.0 g of GBL, stir at 50 ° C. for 24 hours to dissolve it, and confirm that it is completely dissolved. .33 g BCS 10.0 g was added and stirred at room temperature for 30 minutes to obtain an aligning agent [AL-2] having SPI-1 of 6.0% by mass, GBL of 64% by mass, and BCS of 30% by mass.

Example 5
Polymerization of polyamic acid [PAA-2: A-1 / B-8] and preparation of alignment agent [AL-3] In a 50 ml four-necked flask equipped with a nitrogen introduction tube and a mechanical stirrer, 3.35 g of B-8 ( 15.00 mmol), 34.8 g of NMP was added and dissolved, cooled to about 10 ° C. under a nitrogen atmosphere, 2.85 g (14.60 mmol) of A-1 was added little by little, returned to room temperature, and allowed to react for 6 hours. A 15% by mass polyamic acid solution [PAA-2] was obtained.
The obtained PAA-2 had a number average molecular weight of 13,900 and a weight average molecular weight of 28,300.

  10.0 g of this polyamic acid solution was weighed into a 50 ml Erlenmeyer flask equipped with a stir bar, 7.5 g of NMP and 7.5 g of BCS were added, and the mixture was stirred at room temperature for 30 minutes. %, 64% by mass of NMP and 30% by mass of BCS were obtained [AL-3].

Example 6
Synthesis of Soluble Polyimide [SPI-2: A-1 / B-8] and Preparation of Orientation Agent [AL-4] In a 100 ml Erlenmeyer flask equipped with a stirrer, the polyamic acid solution [PAA-] obtained in Example 5 was used. 2] was measured, 34.3 g of NMP was added, 3.32 g of acetic anhydride and 1.37 g of pyridine were added, and the mixture was stirred at room temperature for 30 minutes and then stirred at 50 ° C. for 3 hours for reaction. After the completion of the reaction, the polymer was precipitated slowly into 240 ml of methanol, stirred for 30 minutes, and then a solid was collected by filtration. The obtained solid was sufficiently washed with methanol and then vacuum-dried at 100 ° C. to obtain polyimide [SPI-2]. The number average molecular weight of this polyimide was 12,800, the weight average molecular weight was 26,600, and the imidation ratio was 85%.

  Measure 2.00 g of SPI-2 in a 50 ml Erlenmeyer flask equipped with a stir bar, add 18.0 g of GBL, stir at 50 ° C. for 24 hours to dissolve, and confirm that GBL is completely dissolved. .33 g BCS 10.0 g was added and stirred at room temperature for 30 minutes to obtain an aligning agent [AL-4] having SPI-1 of 6.0% by mass, GBL of 64% by mass, and BCS of 30% by mass.

Example 7
Polymerization of polyamic acid [PAA-3: A-2 / B-7] and preparation of alignment agent [AL-5] In a 50 ml four-necked flask equipped with a nitrogen introduction tube and a mechanical stirrer, 2.33 g of B-7 ( 6.00 mmol), 14.5 g of NMP was added and dissolved, cooled to about 10 ° C. under a nitrogen atmosphere, 1.22 g (5.58 mmol) of A-2 was added little by little, returned to room temperature, and reacted for 6 hours. And a 15% by mass polyamic acid solution [PAA-3] was obtained.
The obtained PAA-3 had a number average molecular weight of 9,600 and a weight average molecular weight of 20,100.

  In a 50 ml Erlenmeyer flask equipped with a stirrer, 15.0 g of this polyamic acid solution was weighed, 11.3 g of NMP and 11.3 g of BCS were added, and the mixture was stirred at room temperature for 30 minutes. %, 64% by mass of NMP and 30% by mass of BCS were obtained [AL-5].

Example 8
Polymerization of polyamic acid [PAA-4: A-2 / B-8] and preparation of alignment agent [AL-6] In a 50 ml four-necked flask equipped with a nitrogen introduction tube and a mechanical stirrer, 2.33 g of B-8 ( 6.00 mmol), 14.5 g of NMP was added and dissolved, cooled to about 10 ° C. under a nitrogen atmosphere, 1.22 g (5.58 mmol) of A-2 was added little by little, returned to room temperature, and reacted for 6 hours. And a 15% by mass polyamic acid solution [PAA-4] was obtained.
The obtained PAA-4 had a number average molecular weight of 9,200 and a weight average molecular weight of 19,900.

  In a 50 ml Erlenmeyer flask equipped with a stirrer, 15.0 g of this polyamic acid solution was weighed, 11.3 g of NMP and 11.3 g of BCS were added, and the mixture was stirred at room temperature for 30 minutes. %, 64% by mass of NMP and 30% by mass of BCS were obtained [AL-6].

Example 9
Synthesis of soluble polyimide [SPI-3: A-1, A-2 (30) / B-2, B-7 (40), B-4 (20)] and preparation of alignment agent [AL-7] Introduction of nitrogen In a 50 ml four-necked flask equipped with a tube and a mechanical stirrer, 0.92 g (7.50 mmol) of B-2, 2.23 g (10.00 mmol) of B-7, 1.74 g (5.00 mmol) of B-4 ) Weighed and dissolved 39.5 g of NMP, cooled to about 10 ° C. under nitrogen atmosphere, added 1.64 g (7.50 mmol) of A-2 little by little, returned to room temperature, reacted for 30 minutes, 3.36 g (17.13 mmol) of A-1 was added and reacted at room temperature for 16 hours to obtain a 20% by mass polyamic acid solution [PAA-6].
The obtained PAA-6 had a number average molecular weight of 12,800 and a weight average molecular weight of 29,600.

  In a 100 ml Erlenmeyer flask equipped with a stir bar, 30.0 g of the polyamic acid solution obtained above was measured, 45.0 g of NMP, 4.39 g (43.00 mmol) of acetic anhydride, and 1.87 g (23.23 mmol) of pyridine. 65 mmol) was added, and the mixture was stirred at room temperature for 30 minutes, and then stirred at 50 ° C. for 3 hours to be reacted. After completion of the reaction, the polymer was slowly poured into 200 ml of methanol to precipitate a polymer, stirred for 30 minutes, and then a solid was collected by filtration. The obtained solid was sufficiently washed with methanol and then vacuum-dried at 100 ° C. to obtain polyimide [SPI-3]. The number average molecular weight of this polyimide was 11,200, the weight average molecular weight was 24,300, and the imidation ratio was 92%.

  Measure 2.00 g of SPI-3 in a 50 ml Erlenmeyer flask equipped with a stir bar, add 18.0 g of GBL, stir at 50 ° C. for 24 hours to dissolve, and confirm that GBL is completely dissolved. .33 g and 10.0 g of BCS were added and stirred at room temperature for 30 minutes to obtain an aligning agent [AL-7] having SPI-3 of 6.0% by mass, GBL of 64% by mass, and BCS of 30% by mass. .

Example 10
Synthesis of Soluble Polyimide [SPI-4: A-1, A-2 (30) / B-2, B-8 (40), B-4 (20)] and Preparation of Orientation Agent [AL-8] 9 B-7 was replaced with B-8 as it was, and the same operation was performed to obtain a 20% by mass polyamic acid solution.
The resulting polyamic acid had a number average molecular weight of 10,600 and a weight average molecular weight of 26,600.

  The same operation as in Example 10 was performed using PAA-6, and an alignment agent [AL-8 containing 6.0% by mass of polyimide [SPI-4] and SPI-4, 64% by mass of GBL, and 30% by mass of BCS was used. ] Was obtained. The number average molecular weight of this polyimide was 9,900, the weight average molecular weight was 21,300, and the imidation ratio was 90%.

Example 11
Synthesis of soluble polyimide [SPI-5: A-1, A-2 (30) / B-2, B-7 (40), B-5 (15)] and preparation of alignment agent [AL-9] Introduction of nitrogen In a 50 ml four-necked flask equipped with a tube and a mechanical stirrer, 1.10 g (9.00 mmol) of B-2, 1.78 g (8.00 mmol) of B-7, 1.22 g (3.00 mmol) of B-5 ) Weigh and add 32.3 g of NMP to dissolve, cool to about 10 ° C. under nitrogen atmosphere, add 1.30 g (6.00 mmol) of A-2 little by little, return to room temperature, react for 30 minutes, 2.67 g (13.60 mmol) of A-1 was added and reacted at room temperature for 16 hours to obtain a 20% by mass polyamic acid solution.
The resulting polyamic acid had a number average molecular weight of 10,900 and a weight average molecular weight of 32,600.

  In a 100 ml Erlenmeyer flask equipped with a stir bar, 30.0 g of the polyamic acid solution [PAA-7] obtained above was weighed, 45.0 g of NMP, 4.39 g (43.00 mmol) of acetic anhydride, and 1 of pyridine. .87 g (23.65 mmol) was added, and the mixture was stirred at room temperature for 30 minutes, and then stirred at 50 ° C. for 3 hours for reaction. After completion of the reaction, the polymer was slowly poured into 200 ml of methanol to precipitate a polymer, stirred for 30 minutes, and then a solid was collected by filtration. The obtained solid was sufficiently washed with methanol and then vacuum-dried at 100 ° C. to obtain polyimide [SPI-5]. The number average molecular weight of this polyimide was 10,200, the weight average molecular weight was 27,300, and the imidation ratio was 94%.

  Measure 2.00 g of SPI-5 in a 50 ml Erlenmeyer flask equipped with a stir bar, add 18.0 g of GBL, and stir at 50 ° C. for 24 hours to confirm that it is completely dissolved. .33 g BCS 10.0 g was added and stirred at room temperature for 30 minutes to obtain an aligning agent [AL-9] having SPI-5 of 6.0% by mass, GBL of 64% by mass and BCS of 30% by mass.

Example 12
Synthesis of soluble polyimide [SPI-6: A-1, A-3 (50) / B-1, B-7 (40), B-6 (20)] and preparation of alignment agent [AL-10] Introduction of nitrogen In a 50 ml four-necked flask equipped with a tube and a mechanical stirrer, 0.65 g (6.00 mmol) of B-1, 1.34 g (6.00 mmol) of B-7, 1.14 g (3.00 mmol) of B-6 ) Weigh and add 25.0 g of NMP to dissolve, add 1.88 g (7.50 mmol) of A-3 at room temperature, react for 4 hours at 80 ° C. in a nitrogen atmosphere, and further add 1.44 g (7 .35 mmol) was added and reacted at room temperature for 16 hours to obtain a 20% by mass polyamic acid solution.
The resulting polyamic acid had a number average molecular weight of 15,900 and a weight average molecular weight of 42,800.

  In a 100 ml Erlenmeyer flask equipped with a stirrer, 30.0 g of the polyamic acid solution obtained above was weighed, 55.7 g of NMP, 6.71 g (65.74 mmol) of acetic anhydride, and 5.20 g (65.74 mmol) of pyridine. 74 mmol) and stirred at room temperature for 30 minutes, and then stirred at 90 ° C. for 2.5 hours for reaction. After completion of the reaction, the polymer was slowly poured into 200 ml of methanol to precipitate a polymer, stirred for 30 minutes, and then a solid was collected by filtration. The obtained solid was sufficiently washed with methanol and then vacuum-dried at 100 ° C. to obtain polyimide [SPI-6]. The number average molecular weight of this polyimide was 14,300, the weight average molecular weight was 33,300, and the imidation ratio was 69%.

  Measure 2.00 g of SPI-6 in a 50 ml Erlenmeyer flask equipped with a stir bar, add 18.0 g of NMP, stir at 50 ° C. for 24 hours to dissolve, and confirm that NMP is completely dissolved. .33 g and 10.0 g of BCS were added and stirred at room temperature for 30 minutes to obtain an aligning agent [AL-10] having SPI-6 of 6.0% by mass, NMP of 64% by mass, and BCS of 30% by mass. .

Example 13
Synthesis of soluble polyimide [SPI-7: A-1, A-4 (50) / B-1, B-7 (40), B-6 (20)] and preparation of alignment agent [AL-11] Introduction of nitrogen In a 50 ml four-necked flask equipped with a tube and a mechanical stirrer, 0.65 g (6.00 mmol) of B-1, 1.34 g (10.00 mmol) of B-7, 1.14 g (5.00 mmol) of B-6 ) Weigh, add 25.0 g of NMP, dissolve, cool to about 10 ° C. under nitrogen atmosphere, add 1.68 g (7.50 mmol) of A-4 little by little, return to room temperature, react for 30 minutes, 1.44 g (7.35 mmol) of A-1 was added and reacted at room temperature for 16 hours to obtain an acid solution.
The resulting polyamic acid had a number average molecular weight of 13,800 and a weight average molecular weight of 39,800.

  In a 100 ml Erlenmeyer flask equipped with a stirrer, 30.0 g of the polyamic acid solution obtained above was weighed, 55.7 g of NMP, 6.71 g (65.74 mmol) of acetic anhydride, and 5.20 g (65.65 mmol) of pyridine. 74 mmol), and the mixture was stirred at room temperature for 30 minutes, and then stirred at 90 ° C. for 3 hours to be reacted. After completion of the reaction, the polymer was slowly poured into 200 ml of methanol to precipitate a polymer, stirred for 30 minutes, and then a solid was collected by filtration. The obtained solid was sufficiently washed with methanol and then vacuum-dried at 100 ° C. to obtain polyimide [SPI-7]. The number average molecular weight of this polyimide was 14,300, the weight average molecular weight was 33,300, and the imidation ratio was 62%.

  Measure 2.00 g of SPI-7 in a 50 ml Erlenmeyer flask equipped with a stir bar, add 18.0 g of NMP, and stir at 50 ° C. for 24 hours to confirm that it is completely dissolved. .33 g and 10.0 g of BCS were added and stirred at room temperature for 30 minutes to obtain an aligning agent [AL-11] having SPI-7 of 6.0% by mass, NMP of 64% by mass, and BCS of 30% by mass. .

Example 14
Synthesis of polyamic acid ester [PAE-1: A-5 / B-1, B-7 (40), B-4 (10)] and preparation of alignment agent [AL-12] A nitrogen introduction tube and a stirrer are provided. In a 100 mL four-necked flask, 2.96 g (11.40 mmol) of A-5, 0.52 g (4.80 mmol) of B-1 as a diamine component, 1.07 g (4.80 mmol) of B-7, B -4 0.41 g (1.20 mmol), NMP 36.5 g and triethylamine 0.60 g (5.90 mmol) were added, cooled to about 10 ° C., and DMT-MM 9.96 g (36.00 mmol) added. The solution was returned to room temperature and reacted for 24 hours in a nitrogen atmosphere to obtain a 12 mass% solution of polyamic acid ester (PAE-1).

  41.4 g of NMP was added to this polyamic acid ester (PAE-1) solution, and the mixture was slowly poured into 500 mL of methanol cooled to about 10 ° C. with stirring to precipitate a solid. The precipitated solid was collected, further dispersed and washed twice with 200 mL of methanol, and dried under reduced pressure at 100 ° C. to obtain a white powder of polyamic acid ester (PAE-1). The number average molecular weight of this polyamic acid ester was 13,500, and the weight average molecular weight was 29,000.

  Measure 2.00 g of polyamic acid ester (PAE-1), add 18.0 g of GBL and stir at 50 ° C. for 24 hours to dissolve, confirm that it is completely dissolved, 3.33 g of GBL and 10 of BCS. 0.0 g was added and stirred at room temperature for 30 minutes to obtain an aligning agent [AL-12] having PAE-1 of 6.0% by mass, GBL of 64% by mass, and BCS of 30% by mass.

Example 15
Synthesis of polyamide [PA-1: A-6, A-7 (50) / B-7] and preparation of orientation agent [AL-13] B-7 was added to a 100 mL four-necked flask equipped with a nitrogen introducing tube and a stirrer. 2.23 g (10.00 mmol), NMP 16.7 g and pyridine 1.98 g (25.00 mmol) were added, cooled to about 10 ° C., A-6 0.91 g (4.80 mmol), A- 7 (1.02 g, 5.00 mmol) was added, and the mixture was returned to room temperature and reacted for 24 hours under a nitrogen atmosphere to obtain a polyamide (PA-1) solution having a concentration of 20% by mass.

  The polyamide (PA-1) solution was added with 32.2 g of NMP to 8.0%, and slowly poured into 500 mL of methanol cooled to about 10 ° C. with stirring to precipitate a solid. The precipitated solid was collected, further dispersed and washed twice with 200 mL of methanol, and dried under reduced pressure at 100 ° C. to obtain a light brown powder of polyamide (PA-1). The number average molecular weight of this polyamic acid ester 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 NMP was added and dissolved by stirring at 50 ° C. for 24 hours, and it was confirmed that it was completely dissolved, and 3.33 g of NMP and 10.0 g of BCS were added. By stirring for 30 minutes at room temperature, an aligning agent [AL-13] having PA-1 of 6.0% by mass, NMP of 64% by mass, and BCS of 30% by mass was obtained.

Comparative Example 1
Polymerization of polyamic acid [PAA-5: A-1 / B-1] and preparation of alignment agent [AL-14] In a 50 ml four-necked flask equipped with a nitrogen introduction tube and a mechanical stirrer, 2.16 g of B-1 ( 20.00 mmol), 32.9 g of NMP was added and dissolved, cooled to about 10 ° C. under a nitrogen atmosphere, 3.64 g (18.60 mmol) of A-1 was added little by little, returned to room temperature, and reacted for 6 hours. And a 15% by mass polyamic acid solution [PAA-5] was obtained.
The obtained PAA-5 had a number average molecular weight of 9,700 and a weight average molecular weight of 19,300.

  10.0 g of this polyamic acid solution was weighed out into a 50 ml Erlenmeyer flask equipped with a stir bar, 7.5 g of NMP and 7.5 g of BCS were added, and the mixture was stirred at room temperature for 30 minutes. %, NMP 64 mass%, BCS 30 mass% orientation agent [AL-14] was obtained, but it was confirmed that the polymer precipitated during refrigerated storage.

Comparative Example 2
Synthesis of Soluble Polyimide [SPI-8: A-1 / B-1] and Preparation of Orientation Agent [AL-15] A polyamic acid solution [PAA-] obtained in Comparative Example 1 was added to a 100 ml Erlenmeyer flask equipped with a stirrer. 5] was measured, 45.0 g of NMP was added, 4.65 g of acetic anhydride and 2.00 g of pyridine were added, and the mixture was stirred at room temperature for 30 minutes and then stirred at 50 ° C. for 3 hours. Gelation occurred and polyimide (SPI-8) could not be prepared. Therefore, alignment agent AL-15 could not be prepared.

Comparative Example 3
Polymerization of polyamic acid [PAA-6: A-1 / B-3] and preparation of alignment agent [AL-16] In a 50 ml four-necked flask equipped with a nitrogen introduction tube and a mechanical stirrer, 2.16 g of B-3 ( 20.00 mmol), 32.9 g of NMP was added and dissolved, cooled to about 10 ° C. under a nitrogen atmosphere, 3.77 g (19.20 mmol) of A-1 was added little by little, returned to room temperature, and reacted for 6 hours. And a 15% by mass polyamic acid solution [PAA-6] was obtained.
The obtained PAA-6 had a number average molecular weight of 11,700 and a weight average molecular weight of 23,200.

  In a 50 ml Erlenmeyer flask equipped with a stir bar, 10.0 g of this polyamic acid solution was weighed, 7.5 g of NMP and 7.5 g of BCS were added, and the mixture was stirred at room temperature for 30 minutes. PAA-6 was 6.0 mass. %, 64% by mass of NMP and 30% by mass of BCS were obtained [AL-16].

Comparative Example 4
Synthesis of Soluble Polyimide [SPI-9: A-1 / B-3] and Preparation of Orientation Agent [AL-17] The polyamic acid solution [PAA-] obtained in Comparative Example 3 was added to a 100 ml Erlenmeyer flask equipped with a stirrer. 6] was measured, 35.0 g of NMP was added, 45.0 g of NMP, 4.65 g of acetic anhydride and 2.00 g of pyridine were added, and the mixture was stirred at room temperature for 30 minutes and then stirred at 50 ° C. for 3 hours. Gelation occurred and polyimide (SPI-9) could not be prepared. Therefore, alignment agent AL-17 could not be prepared.

Comparative Example 5
Polymerization of polyamic acid [PAA-7: A-1 / B-5, B-4 (10)] and preparation of alignment agent [AL-18] In a 50 ml four-necked flask equipped with a nitrogen introduction tube and a mechanical stirrer, -5 (3.570 g, 18.00 mmol) and B-4 (0.75 g, 2.00 mmol) were weighed, 31.9 g of NMP was added and dissolved, cooled to about 10 ° C. under a nitrogen atmosphere, A-1 3.72 g (19.0 mmol) was added little by little and reacted at room temperature for 16 hours to obtain a 20% by mass polyamic acid solution [PAA-7].
The obtained PAA-7 had a number average molecular weight of 11,800 and a weight average molecular weight of 30,200.

  10.0 g of this polyamic acid solution was weighed into a 50 ml Erlenmeyer flask equipped with a stir bar, 7.5 g of NMP and 7.5 g of BCS were added, and the mixture was stirred at room temperature for 30 minutes. %, 64% by mass of NMP and 30% by mass of BCS were obtained [AL-18].

Comparative Example 6
Synthesis of Soluble Polyimide [SPI-10: A-1 / B-5, B-4 (10)] and Preparation of Orientation Agent [AL-19] Obtained in Comparative Example 5 in a 100 ml Erlenmeyer flask equipped with a stirrer Weighed 30.0 g of the polyamic acid solution [PAA-7], added 55.7 g of NMP, 4.62 g (45.3 mmol) of acetic anhydride, and 1.91 g (24.2 mmol) of pyridine, and stirred at room temperature for 30 minutes. Then, the reaction was carried out at 45 ° C., but gelled. Therefore, orientation agent AL-19 could not be obtained.

Comparative Example 7
Synthesis of Soluble Polyimide [SPI-11: A-1, A-4 (50) / B-1, B-6 (20)] and Preparation of Orientation Agent [AL-20] A nitrogen introduction tube and a mechanical stirrer were provided. In a 50 ml four-necked flask, 1.08 g (10.00 mmol) of B-1 and 1.14 g (5.00 mmol) of B-6 were measured, 25.0 g of NMP was added and dissolved, and the temperature was about 10 ° C. under a nitrogen atmosphere. Then, 1.68 g (7.50 mmol) of A-4 was added little by little, returned to room temperature, allowed to react for 30 minutes, and 1.44 g (7.35 mmol) of A-1 was further added, and reacted at room temperature for 16 hours. A polyamic acid solution was obtained.
The resulting polyamic acid had a number average molecular weight of 13,800 and a weight average molecular weight of 39,800.

  In a 100 ml Erlenmeyer flask equipped with a stirrer, 30.0 g of the polyamic acid solution obtained above was weighed, 55.7 g of NMP, 6.71 g (65.74 mmol) of acetic anhydride, and 5.20 g (65.65 mmol) of pyridine. 74 mmol), and the mixture was stirred at room temperature for 30 minutes, and then stirred at 90 ° C. for 3 hours to be reacted. After completion of the reaction, the polymer was slowly poured into 200 ml of methanol to precipitate a polymer, stirred for 30 minutes, and then a solid was collected by filtration. The obtained solid was sufficiently washed with methanol and then vacuum-dried at 100 ° C. to obtain polyimide [SPI-11]. The number average molecular weight of this polyimide was 13,200, the weight average molecular weight was 30,710, and the imidation ratio was 62%.

  Measure 2.00 g of SPI-11 in a 50 ml Erlenmeyer flask equipped with a stir bar, add 18.0 g of NMP, stir at 50 ° C. for 24 hours to dissolve, and confirm that NMP is completely dissolved. .33 g BCS 10.0 g was added and stirred at room temperature for 30 minutes to obtain an aligning agent [AL-20] having SPI-11 of 6.0% by mass, NMP of 64% by mass, and BCS of 30% by mass.

Comparative Example 8
Synthesis of polyamic acid ester [PAE-2: A-5 / B-1, B-4 (10)] and preparation of alignment agent [AL-21] A in a 100 mL four-necked flask equipped with a nitrogen inlet tube and a stirrer 2.96 g (11.40 mmol) of -5, as a diamine component, 1.16 g (10.80 mmol) of B-1, 0.45 g (1.20 mmol) of B-4, 30.6 g of NMP, triethylamine 0 .60 g (5.90 mmol) was added, cooled to about 10 ° C., 9.96 g (36.00 mmol) of DMT-MM was added, the mixture was returned to room temperature and reacted for 24 hours under a nitrogen atmosphere, and polyamic acid ester (PAE-2) A solution having a concentration of 12% by mass was obtained.

  41.4 g of NMP was added to this polyamic acid ester (PAE-2) solution, and the mixture was slowly poured into 500 mL of methanol cooled to about 10 ° C. with stirring to precipitate a solid. The precipitated solid was collected, further dispersed and washed twice with 200 mL of methanol, and dried under reduced pressure at 100 ° C. to obtain a white powder of polyamic acid ester (PAE-2). The number average molecular weight of this polyamic acid ester was 11,700, and the weight average molecular weight was 26,000.

  2.00 g of polyamic acid ester (PAE-2) was measured, 18.0 g of GBL was added and stirred at 50 ° C. for 24 hours to dissolve, and it was confirmed that it was completely dissolved. 3.33 g of GBL and 10 BCS were obtained. 0.0 g was added and stirred at room temperature for 30 minutes to obtain an aligning agent [AL-21] having PAE-2 of 6.0% by mass, GBL of 64% by mass, and BCS of 30% by mass.

Comparative Example 9
Synthesis of Polyamide [PA-2: A-6, A-7 (50) / A-1] and Preparation of Orientation Agent [AL-22] B-1 was added to a 100 mL four-necked flask equipped with a nitrogen inlet tube and a stirrer. 1.08 g (10.00 mmol), NMP 16.7 g and pyridine 1.98 g (25.00 mmol) were added and cooled to about 10 ° C., A-6 0.91 g (4.80 mmol), A- 7 (1.02 g, 5.00 mmol) was added, and the mixture was returned to room temperature and reacted for 24 hours under a nitrogen atmosphere. However, since a polymer was precipitated during the reaction, the alignment agent AL-22 could not be obtained.

Comparative Example 10
Synthesis of Polyamide [PA-3: A-6, A-7 (50) / B-3] and Preparation of Orientation Agent [AL-23] B-3 was added to a 100 mL four-necked flask equipped with a nitrogen introduction tube and a stirrer. 1.08 g (10.00 mmol), NMP 16.7 g and pyridine 1.98 g (25.00 mmol) were added and cooled to about 10 ° C., A-6 0.91 g (4.80 mmol), A- 7 (1.02 g, 5.00 mmol) was added, and the mixture was returned to room temperature and reacted for 24 hours under a nitrogen atmosphere. However, since a polymer was precipitated during the reaction, it was not possible to obtain alignment agent AL-23.

Comparative Example 11
Synthesis of Polyamide [PA-4: A-6 / B-3] and Preparation of Alignment Agent [AL-24] 1.08 g of B-3 was added to a 100 mL four-necked flask equipped with a nitrogen introducing tube and a stirrer (10. 00 mmol), 16.7 g of NMP and 1.98 g (25.00 mmol) of pyridine were added, cooled to about 10 ° C., 1.50 g (9.70 mmol) of A-6 was added, the temperature was returned to room temperature, and 24 hours under a nitrogen atmosphere. Reacted. After completion of the reaction, the mixture was slowly poured into 300 ml of acetone to precipitate a solid. The precipitated solid was collected, further dispersed and washed twice with 200 mL of methanol, and dried under reduced pressure at 100 ° C. to obtain a light gray powder of polyamide (PA-4). The number average molecular weight of this polyamide was 8,500, and the weight average molecular weight was 17,900.

  2.00 g of polyamide (PA-4) was weighed, 18.0 g of NMP was added and stirred at 50 ° C. for 24 hours to dissolve, and it was confirmed that it was completely dissolved. 3.3 g of NMP and 10.0 g of BCS In addition, by stirring at room temperature for 30 minutes, an aligning agent [AL-24] having PA-4 of 6.0% by mass, NMP of 64% by mass, and BCS of 30% by mass was obtained.

  Since the polymer using the diamine of the present invention has high solubility in a solvent, even if it does not become a soluble polymer as in Comparative Examples 1, 2, 4, 6, 10, and 11, the monomer of the present invention is introduced. It becomes possible to make it a soluble polymer. In other words, since the solubility in a solvent becomes high, it becomes possible to introduce a large amount of a poor solvent having good substrate wettability, and precipitation and whitening are less likely to occur during printing. The liquid crystal aligning agent which can be improved and has favorable printability can be obtained.

  With the liquid crystal aligning agent of the present invention, it is possible to obtain a liquid crystal alignment film that is resistant to film peeling and scraping during rubbing, has a high voltage holding ratio, and does not easily accumulate initial charge even when a DC voltage is applied. Therefore, the liquid crystal display element produced using the liquid crystal aligning agent of the present invention can be a highly reliable liquid crystal display device, and includes a TN liquid crystal display element, an STN liquid crystal display element, a TFT liquid crystal display element, and a VA liquid crystal display. It is suitably used for display elements by various methods such as an element, an IPS liquid crystal display element, and an OCB liquid crystal display element.

Claims (8)

A polymer comprising a polyamide obtained by using a diamine represented by the following general formula [1], a polyamic acid, a polyamic acid ester, or a polyimide obtained by dehydrating and ring-closing (imidizing) the polyamic acid and / or the polyamic acid ester .

(In the formula, A represents an organic group that can be removed by heat. The NHA group has n (n = 1 or 2), and exists in the ortho position with respect to the amino group (NH ₂ group). They are in meta or para position.) 2. The polymer according to claim 1, wherein in the general formula [1], the organic group capable of leaving by the heat of A is a tert-butoxycarbonyl group. The polymer according to claim 1 or 2, comprising 5 to 95 mol% of the diamine represented by the general formula [1]. The polymer according to any one of claims 1 to 3, comprising 5 to 50 mol% of a diamine containing a side chain represented by the following general formula [2].

(In the formula, R ¹ represents a single bond or a divalent organic group, X ¹ , X ² , and X ³ each independently represent a benzene ring or a cyclohexane ring, and p, q, and r each independently represents 0. Or an integer of 1 and R ² represents a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or a divalent organic group having 12 to 25 carbon atoms having a steroid skeleton.) A liquid crystal aligning agent comprising the polymer according to claim 1. The liquid crystal aligning film using the liquid crystal aligning agent of Claim 5. A liquid crystal display device comprising the liquid crystal alignment film according to claim 6. Diamine shown by the following general formula [1-5] or [1-6].