JP5660160B2 - Diamine compound - Google Patents

Description

  The present invention relates to a diamine compound which is a raw material such as a liquid crystal alignment treatment agent used in a liquid crystal display element.

Currently, as a liquid crystal alignment film of a liquid crystal display element, a so-called polyimide-based liquid crystal alignment film obtained by applying and baking a liquid crystal alignment treatment agent mainly composed of a polyimide precursor such as polyamic acid or a soluble polyimide solution is mainly used. ing.
The liquid crystal alignment film not only controls the alignment state of the liquid crystal but also affects the characteristics of the liquid crystal display element. In particular, as the definition of a liquid crystal display element becomes higher, characteristics such as suppression of a decrease in contrast of the liquid crystal display element and reduction of an afterimage phenomenon have become important.
In a polyimide-based liquid crystal alignment film, a liquid crystal aligning agent containing a tertiary amine with a specific structure in addition to polyamic acid or imide group-containing polyamic acid is used as a short time until the afterimage generated by direct current voltage disappears (For example, refer to Patent Document 1), and those using a liquid crystal alignment treatment agent containing a soluble polyimide using a specific diamine having a pyridine skeleton as a raw material (for example, refer to Patent Document 2).
In addition, in the polyimide-based liquid crystal alignment film, it is assumed that the voltage holding ratio is high and the time until the afterimage generated by the DC voltage disappears is short, and in addition to polyamic acid and its imidized polymer, 1 in the molecule. Contains a very small amount of a compound selected from a compound containing one carboxylic acid group, a compound containing one carboxylic anhydride group in the molecule, and a compound containing one tertiary amino group in the molecule. One using a liquid crystal aligning agent (for example, see Patent Document 3) is known.

JP 9-316200 A JP-A-10-104633 JP-A-8-76128

Until now, as a method for dealing with the afterimage phenomenon of the liquid crystal panel, the time until the afterimage disappears has been shortened, but that alone has not been sufficient.
In view of the above situation, the present invention provides 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 to the liquid crystal cell. It aims at providing the diamine compound used as the raw material of the liquid-crystal aligning agent which can be obtained.

As a result of intensive studies to achieve the above object, the present inventors have completed the present invention. That is, the present invention has the following gist .

( 1) A diamine compound represented by the following formula [2].

（フラン環の任意の水素原子は、炭素数１〜５のアルキル基で置換されていてもよく、ベンゼン環上の２つのアミノ基の位置関係はメタまたはパラである。）
（２）フラン環の任意の水素原子が、メチル基で置換されていてもよい上記（１）に記載のジアミン化合物。
（３）上記（１）又は（２）に記載のジアミン化合物を含有するジアミン成分と、テトラカルボン酸二無水物成分とを反応させて得られるポリアミック酸、又は該ポリアミック酸をイミド化して得られるポリイミド。

(Optional hydrogen atom of the furan ring, rather it may also be substituted with an alkyl group having 1 to 5 carbon atoms, positional relationship between the two amino groups on the benzene ring is meta or para.)
( 2 ) The diamine compound according to ( 1 ), wherein any hydrogen atom of the furan ring may be substituted with a methyl group.
( 3 ) A polyamic acid obtained by reacting the diamine component containing the diamine compound according to ( 1 ) or ( 2 ) above and a tetracarboxylic dianhydride component, or obtained by imidizing the polyamic acid. Polyimide.

The treating agent for liquid crystal alignment using a diamine compound of the present invention is strong against peeling and chipping during rubbing, high voltage holding ratio, and unlikely to occur accumulation of initial charge even DC voltage is applied to the liquid crystal cell liquid crystal An alignment film can be obtained, and by using this liquid crystal alignment film, a liquid crystal panel with good characteristics can be manufactured.

The liquid crystal aligning agent using the diamine compound of the present invention is a polyamic acid obtained by reacting a diamine component containing a diamine represented by the following formula [1] with a tetracarboxylic dianhydride component, and the polyamic acid. It is a liquid-crystal aligning agent containing the at least 1 type polymer of the polyimide which imidated the acid. By using this diamine, even in the rubbing treatment required for the liquid crystal alignment treatment, film peeling and scraping during rubbing can be reduced, and the obtained liquid crystal alignment film has a high voltage holding ratio, and liquid crystal Even when a DC voltage is applied to the cell, it is possible to prevent the initial charge accumulation.

<Diamine of Formula [1]>
The method for synthesizing the diamine represented by the formula [1] is not particularly limited. For example, a dinitro compound represented by the following formula [S1] is synthesized, and the nitro group is reduced by a usual method. It can be synthesized by a method of converting to an amino group.

X in the above formula [1] and the formula [S1] represents -NHCO-.
Further, Y in the formula [1] and formula [S1] represents SansoHara child.
Furthermore, an arbitrary hydrogen atom of a five-membered ring (hereinafter also referred to as a furan ring ) in which Y is an oxygen atom may be substituted with an alkyl group having 1 to 5 carbon atoms. The number of substituents on the furan ring is preferably 0 to 2, more preferably unsubstituted. Thereby, better rubbing resistance can be obtained.
In the above formula [1] and formula [S1], the position at which the furan ring is bonded to X is not particularly limited, but is preferably the 2nd or 3rd position.
In a liquid crystal alignment film obtained using a diamine in which X is —NHCO—, the voltage holding ratio when a liquid crystal panel is obtained is increased .
In diamine represented by the formula [1], the positional relationship between the two amino groups on the benzene ring, from the viewpoint of the liquid crystal orientation when the liquid crystal alignment film, it is meta or para. Further, in view of increasing the solubility in an organic solvent in the polymerization reactivity and the resulting polyamic acid or polyimide, meta virtuous preferable. When the positional relationship between the two amino groups is the meta position, that is, in the case of a 1,3-diaminobenzene structure, the X position is preferably the 4 or 5 position, and particularly the effect of increasing the nucleophilicity of the amino group From the viewpoint of easy synthesis, the position of 5 is more preferable.
In the diamine represented by the formula [1], the position of X in the cis-diene ring (hereinafter also referred to as furan ring ) is not particularly limited. From the viewpoint of availability of raw materials, reactivity, and the like, The combination is appropriately selected according to the purpose.
Specific examples in the case where Y is an oxygen atom (in the case of a furan ring) are shown below, but are not limited thereto.

(上記式中のＸは、−ＮＨＣＯ−を表し、Ｒは炭素原子数１〜５のアルキル基を表し、ｎは０〜３の整数を表す。)

(X in the above formula represents -NHCO-, R represents an alkyl group having 1 to 5 carbon atoms, n represents an integer of 0 to 3.)

In the above formula [T1] ~ formula [T6], X is -NHCO-, R is preferably an alkyl group having 1 to 3 carbon atoms, n represents an integer of 0 or 1 is preferred. In addition, in the above formula, the structure of the formula [T2] or the formula [T5] is preferable from the viewpoints of solvent solubility of polyamic acid and polyimide, liquid crystal orientation, rubbing resistance, and accumulated charge (hereinafter also referred to as RDC).
Especially, it has the structure of Formula [T2] or Formula [T5], X is -NHCO-, R is a C1-C3 alkyl group, and n is an integer of 0 or 1. preferable. Linking group X is used diamine is -NHCO- when high voltage holding ratio, preferably.

< Synthesis of diamine>
The specific diamine compound of the present invention can be obtained by synthesizing a dinitro compound represented by the formula [S1], further reducing the nitro group and converting it to an amino group. The method for reducing the dinitro compound is not particularly limited, and palladium-carbon, platinum oxide, Raney nickel, platinum black, rhodium-alumina, platinum sulfide carbon, etc. are used as a catalyst. Ethyl acetate, toluene, tetrahydrofuran, dioxane, alcohol system In a solvent such as hydrogen gas, hydrazine, or hydrogen chloride. X of formula [S1] represents -NHCO-, Y represents an oxygen atom, any hydrogen atom of the five-membered ring may be substituted with an alkyl group having 1 to 5 carbon atoms.

ジニトロ体の合成法は、結合基により種々異なる。

The synthesis method of the dinitro compound varies depending on the bonding group .

When X is -NHCO-, for example, a dinitro body can be obtained by condensation reaction of dinitroaniline and furancarboxylic acid or thiophenecarboxylic acid. Although the condensation method is not particularly limited, dinitro form [S7] can be obtained by reacting dinitroaniline [S5] with carboxylic acid chloride [S6] in the presence of a base. In addition, a method of reacting an amine and a carboxylic acid in the presence of a dehydrating condensing agent can be mentioned.

By using a reagent in which an alkyl group is added to the furan ring , or by adding an alkyl group in advance, a furan ring having a side chain can be obtained.

<Diamine component>
The diamine represented by the formula [1] can be obtained by reacting with tetracarboxylic dianhydride to obtain a polyamic acid, and imidating the polyamic acid to obtain a polyimide. In the liquid crystal aligning agent using the diamine compound of the present invention, the diamine component used when synthesizing the polyamic acid may be only the diamine represented by the formula [1], or one selected from other diamines. Or you may combine 2 or more types.
By containing the diamine represented by the formula [1] as the diamine component, the solubility of the resulting polyamic acid and the polyimide imidized with this polyamic acid in an organic solvent can be increased. Furthermore, the liquid crystal alignment film obtained from the liquid crystal aligning agent containing this polyamic acid or polyimide has excellent rubbing resistance, high voltage holding ratio, and initial charge even when a DC voltage is applied to the liquid crystal cell. Accumulation is unlikely to occur. In order to obtain such characteristics, the diamine represented by the formula [1] is preferably 10 to 100 mol%, more preferably 20 to 100 mol% of the total diamine component used for the synthesis of the polyamic acid. Especially preferably, it is 30-100 mol%.
In said diamine component, the diamine used in combination with the diamine represented by Formula [1] is not specifically limited. Specific examples of such diamines are shown below.

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

  Examples of aromatic diamines include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, 3,5-diaminotoluene, 3,5-diamino- N, N-diallylaniline, 2,4-diamino-N, N-diallylaniline, 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′-dimethylbi Benzyl, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diamidine -3,3'-dimethyldiphenylmethane, 2,2'-diaminostilbene, 4,4'-diaminostilbene, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 4,4′-diaminodiphenylsulfone, 3,3′-diaminodiphenylsulfone, 4,4′-diaminobenzophenone, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-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] hex Fluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, 1 , 1-bis (4-aminophenyl) 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, -Diaminopyrene, 2,7-diaminofluorene, 1,3-bis (4-aminophenyl) tetramethyldisiloxane, benzidine, 2,2'-dimethylbenzidine, 1,2-bis (4-aminophenyl) ethane, 1,3-bis (4-aminophenyl) propane, 1,4-bis (4-aminophenyl) butane, 1,5-bis (4-aminophenyl) pentane, 1,6-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-amino) Phenyl) decane, 1,3-bis (4-aminophenoxy) propane, 1,4-bis (4-aminophenoxy) butane, 1,5-bis (4-aminophenoxy) Nthane, 1,6-bis (4-aminophenoxy) hexane, 1,7-bis (4-aminophenoxy) heptane, 1,8-bis (4-aminophenoxy) octane, 1,9-bis (4-amino) Phenoxy) 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-bis [4- (4-aminophenoxy) phenoxy] butane, 1,5-bis [4- (4-aminophenoxy) phenoxy ] Pentane, 1,6-bis [4- (4-aminophenoxy) phenoxy] hexane, 1,7-bis [4- (4-aminophenoxy) phenoxy] heptane, 1,8-bis [4- (4- Aminophenoxy) phenoxy] octane, 1,9-bis [4- (4-aminophenoxy) phenoxy] nonane, 1,10-bis [4- (4-aminophenoxy) phenoxy] decane and the like.

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

Examples of aliphatic diamines include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,3-diamino-2,2-dimethylpropane, 1,6-diamino-2,5-dimethylhexane, 1,7- Diamino-2,5-dimethylheptane, 1,7-diamino-4,4-dimethylheptane, 1,7-diamino-3-methylheptane, 1,9-diamino-5-methylheptane, 1,12-diaminododecane 1,18-diaminooctadecane, 1,2-bis (3-aminopropoxy) ethane and the like.
Examples of the aromatic-aliphatic diamine include a diamine represented by the formula [11].

Here, Ar in the formula is phenylene or naphthylene, R ₁ is an alkylene group having 1 to 5 carbon atoms, and R ₂ is a hydrogen atom or a methyl group.
Specific examples of the diamine represented by the formula [11] include 3-aminobenzylamine, 4-aminobenzylamine, 3-amino-N-methylbenzylamine, 4-amino-N-methylbenzylamine, and 3-amino. Phenethylamine, 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-Methylaminobutyl) aniline, 3- (5-aminopentyl) aniline, 4- (5-aminopen) L) aniline, 3- (5-methylaminopentyl) aniline, 4- (5-methylaminopentyl) aniline, 2- (6-aminonaphthyl) methylamine, 3- (6-aminonaphthyl) methylamine, 2- (6-Aminonaphthyl) ethylamine, 3- (6-aminonaphthyl) ethylamine and the like can be mentioned.

When the diamine represented by the formula [11] is used in combination with the diamine represented by the formula [1], the solubility of the resulting polyamic acid or polyimide (hereinafter referred to as a polymer) in an organic solvent is further improved. Moreover, since it is excellent in liquid crystal orientation, when using as a liquid crystal aligning film, it is preferable. Furthermore, when a diamine that increases the pretilt angle of the liquid crystal described later (hereinafter also referred to as tilt diamine) is used in combination, the effect of further increasing the pretilt angle of the liquid crystal is obtained. Therefore, when trying to obtain the same pretilt angle, a large tilt angle can be obtained even if the amount of tilt diamine used is small. In addition, an improvement in the printability of the liquid crystal aligning agent can be expected.
The preferable content of the diamine represented by the formula [11] is 10 to 80 mol%, preferably 20 to 70 mol% of the entire diamine component.

Examples of the diamine that can increase the pretilt angle of the liquid crystal (tilt diamine) include a long-chain alkyl group, a perfluoroalkyl group, an aromatic cyclic group, an aliphatic cyclic group, a combination of these, and a steroid skeleton group. A diamine having These diamines can be used in combination with the diamine represented by the formula [1].
Hereinafter, such a concrete example of the diamine having a substituent is not limited to these. In addition, in formula [13]-formula [38] illustrated below, j represents the integer of 5-20 and k represents the integer of 1-20.

Among the above diamines, the diamine of the formula [12] is preferable because of excellent liquid crystal alignment. Since the diamines of the formulas [19] to [26] have a very high pretilt angle development ability, they are OCB (Optically Compensated Bend) liquid crystal alignment films (hereinafter referred to as OCB alignment films) and vertical alignment mode liquid crystal applications. It is suitably used for an alignment film (hereinafter referred to as VA alignment film).
For example, in the alignment film for TN liquid crystal (pretilt angle is 3 to 5 °), the content of the diamine of the formula [12] is preferably 10 to 30 mol% of the total diamine component, and the alignment film for OCB or the alignment film for VA ( When the pretilt angle is 10 to 90 °, the diamine content of the formula [19] to the formula [26] is preferably 5 to 40 mol% of the total diamine component, but is not limited thereto.
In consideration of the balance of each characteristic such as solubility of polyamic acid or polyimide used in the liquid crystal alignment treatment agent using the diamine compound of the present invention, alignment property of liquid crystal, tilt angle, voltage holding ratio, accumulated charge, etc. When polymerizing using the diamine components represented by [1], formula [11], and formula [12], the preferred ratio of each diamine component is 10 to 50% (formula [1]) / 20 to 80% (formula [11]) / 10 to 30% (formula [12]) is preferable, more preferably 20 to 40% / 30 to 50% / 10 to 30%, but it is necessary to limit to this. There is no.

<Tetracarboxylic dianhydride component>
In the polyamic acid or polyimide required for the liquid crystal aligning agent using the diamine compound of the present invention, the tetracarboxylic dianhydride component to be reacted with the diamine component is not particularly limited. That is, one type of tetracarboxylic dianhydride may be used, or two or more types of tetracarboxylic dianhydrides may be used in combination.
In the liquid crystal aligning agent using the diamine compound of the present invention, as a tetracarboxylic dianhydride to be reacted with the diamine component, an alicyclic structure or a fat is used from the viewpoint that the voltage holding ratio of the liquid crystal cell can be further improved. It is preferable to use a tetracarboxylic dianhydride having a group structure.
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-cyclohexylsuccinic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, [4 (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride], 1,2,3,4-butanetetracarboxylic dianhydride , Bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5- Tricarboxycyclopentylacetic 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-tetracarbo Acid -4,5: 11,12-dianhydride, and the like. Among these, it is particularly preferable to use 1,2,3,4-cyclobutanetetracarboxylic dianhydride because an alignment film having excellent liquid crystal alignment can be obtained.

Furthermore, when an aromatic tetracarboxylic dianhydride is used in combination, the liquid crystal alignment can be improved and the stored charge in the liquid crystal cell can be released quickly. 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. Of these, pyromellitic dianhydride is particularly preferable.
The tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure is considered in consideration of the balance of each characteristic such as solubility of the obtained polyamic acid or polyimide, orientation of liquid crystal, voltage holding ratio, accumulated charge, etc. And the use ratio of the aromatic tetracarboxylic dianhydride is preferably 90/10 to 50/50, more preferably 80/20 to 60/40 in terms of the former / the latter molar ratio.

<Polymerization reaction>
In the liquid crystal aligning agent using the diamine compound of the present invention, the polymerization reaction method of the tetracarboxylic dianhydride component and the diamine component is not particularly limited. Generally, by mixing in an organic solvent, a polymerization reaction can be performed to obtain a polyamic acid, and a polyimide can be obtained by dehydrating and ring-closing this polyamic acid.
As a method of mixing the tetracarboxylic dianhydride component and the diamine component in an organic solvent, a solution in which the diamine component is dispersed or dissolved in the organic solvent is stirred, and the tetracarboxylic dianhydride component is used as it is or in an organic solvent. A method of adding by dispersing or dissolving in a solvent, a method of adding a diamine component to a solution in which a tetracarboxylic dianhydride component is dispersed or dissolved in an organic solvent, and a tetracarboxylic dianhydride component and a diamine component. The method of adding alternately etc. are mentioned. Moreover, when a tetracarboxylic dianhydride component or a diamine component consists of multiple types of compounds, the polymerization reaction may be performed in a state where these multiple types of components are mixed in advance, or the polymerization reaction may be sequentially performed individually.
The temperature at which the tetracarboxylic dianhydride component and the diamine component are subjected to a polymerization reaction in an organic solvent is usually 0 to 150 ° C, preferably 5 to 100 ° C, more preferably 10 to 80 ° C. When the temperature is higher, the polymerization reaction is completed earlier, but when it is too high, a high molecular weight polymer may not be obtained.
In addition, the polymerization reaction can be performed at any concentration, but if the total concentration of the tetracarboxylic dianhydride component and the diamine component is too low, it becomes difficult to obtain a high molecular weight polymer, and if the concentration is too high, Since the viscosity of the reaction solution becomes too high and uniform stirring becomes difficult, the total concentration is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The initial stage of the polymerization reaction may be performed at a high concentration, and then an organic solvent may be added.

  The organic solvent used in the polymerization reaction is not particularly limited as long as the generated polyamic acid is soluble. Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, Examples include pyridine, dimethyl sulfone, hexamethyl sulfoxide, γ-butyrolactone, 1,3-dimethylimidazolidinone. These may be used alone or in combination. Furthermore, even if the solvent does not dissolve the polyamic acid, it 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 generated polyamic acid, it is preferable to use a dehydrated and dried organic solvent as much as possible.

The ratio of the tetracarboxylic dianhydride component to the diamine component used for the polymerization reaction of the polyamic acid is preferably 1: 0.8 to 1: 1.2 in terms of molar ratio, and this molar ratio is close to 1: 1. As the molecular weight of the polyamic acid obtained increases. By controlling the molecular weight of this polyamic acid, the molecular weight of the polyimide obtained after imidation can be adjusted.
The molecular weight of the Po polyamic acid or the polyimide is not particularly limited, if to be contained in the liquid crystal alignment treating agent, from the viewpoint of ease of handling as strength and the liquid crystal alignment treating agent of the resulting coating film, a weight average molecular weight 2,000 to 200,000 is preferable, and more preferably 5,000 to 50,000.

<Synthesis of polyimide>
The polyimide used for the liquid crystal aligning agent using the diamine compound of the present invention is a polyimide obtained by imidizing the above polyamic acid. The imidization of the polyamic acid can be performed by stirring in an organic solvent for 1 to 100 hours in the presence of a basic catalyst and an acid anhydride.
Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Of these, pyridine is preferable because it has an appropriate basicity for proceeding with the reaction.
Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like. Among them, acetic anhydride is preferable because the obtained polyimide can be easily purified after imidization.
As an organic solvent, the solvent used at the time of the polyamic acid polymerization reaction mentioned above can be used.
The imidation ratio of polyimide can be controlled by adjusting the amount of catalyst, reaction temperature, reaction time, and the like. The amount of the basic catalyst at this time is preferably 0.2 to 10 times mol, more preferably 0.5 to 5 times mol of the amic acid group. Moreover, 1-30 times mole of an acid anhydride group is preferable, More preferably, the amount of an acid anhydride is 1-10 times mole. The reaction temperature is preferably -20 to 250 ° C, more preferably 0 to 180 ° C.
Although the imidation ratio of the polyimide used for the liquid crystal aligning agent using the diamine compound of the present invention is not particularly limited, the imidation ratio is 40% or more because a liquid crystal alignment film having a higher voltage holding ratio is obtained. It is preferably 60% or more, particularly preferably 80% or more.

Since the added catalyst or the like remains in the polyimide solution thus obtained, when used as a liquid crystal alignment treatment agent, it is preferable to recover and wash the polyimide before use.
The polyimide can be recovered by adding the solution after imidization with stirring with a poor solvent, and precipitating the polyimide, followed by filtration. Examples of the poor solvent at this time include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, and benzene. The recovered polyimide can also be washed with this poor solvent. The polyimide recovered and washed in this way can be powdered by drying at normal temperature or under reduced pressure at room temperature or by heating.
Such an operation can also be performed on the polyamic acid. For example, when it is not desired to include the solvent used for the polymerization of polyamic acid in the liquid crystal aligning agent, or when it is desired to remove unreacted monomer components and impurities in the reaction solution, the above precipitation recovery and purification are performed. Just do it.

<Liquid crystal alignment agent>
The liquid-crystal aligning agent using the diamine compound of this invention is a coating liquid containing at least 1 type of polymer of the polyamic acid and polyimide obtained as mentioned above.
When the production example is given, the reaction solution of the polyamic acid or polyimide described above may be used as it is or diluted, and the precipitate recovered from the reaction solution may be redissolved in an organic solvent. In the dilution and re-dissolution process, adjustment of the solvent composition for controlling the coating property to the substrate, addition of an additive for improving the properties of the coating film, and the like can be performed. Furthermore, you may mix with the solution of the polyimide of the structure different from the above, the solution of a polyamic acid, and you may add another resin component.
The organic solvent used in the dilution and re-dissolution process is not particularly limited as long as it can dissolve the polymer contained therein. Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethyl-2-pyrrolidone, N-vinylpyrrolidone. Dimethyl sulfoxide, tetramethyl urea, dimethyl sulfone, hexamethyl sulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, and the like. Of these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, and γ-butyrolactone are preferably used. You may use these 1 type or in mixture of 2 or more types.

Solvents added to control the coating property of the liquid crystal aligning agent on the substrate include ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1 -Ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, diethylene glycol diethyl ether, propylene glycol monoacetate, propylene glycol diacetate, dipropylene glycol monomethyl ether, propylene glycol-1-monomethyl ether -2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, milk Methyl ester, ethyl lactate esters, lactate n- propyl ester, lactate n- butyl ester, and the like lactic isoamyl ester. These solvents include solvents that cannot dissolve polyamic acid or polyimide by themselves, but they can be mixed with the liquid crystal aligning agent using the diamine compound of the present invention as long as the polymer does not precipitate. Can do. In particular, by properly mixing a solvent having a low surface tension, the uniformity of the coating film can be improved at the time of application to the substrate, and it is also suitably used in the liquid crystal alignment treatment agent using the diamine compound of the present invention. Among these, butyl cellosolve, ethyl carbitol, dipropylene glycol monomethyl ether, and diethylene glycol diethyl ether are particularly preferable from the viewpoint of solubility of polyimide.

  Additives for improving the properties of the coating include 3-aminopropylmethyldiethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, (aminoethylaminomethyl) phenethyltrimethoxysilane And silane coupling agents such as The addition of these silane coupling agents can improve the adhesion of the coating film to the substrate. However, when the addition amount is excessive, polyamic acid, polyimide, and the like tend to aggregate. Therefore, content of a silane coupling agent becomes like this. Preferably it is 0.5-10 mass% with respect to the total mass of a polyamic acid and a polyimide, More preferably, it is 1-5 mass%.

Although the solid content concentration of the liquid-crystal aligning agent using the diamine compound of this invention can be suitably changed with the setting of the thickness of the liquid crystal aligning film to form, it is preferable to set it as 1-10 mass%. If it is less than 1% by mass, it is difficult to form a uniform and defect-free coating film, and if it exceeds 10% by mass, the storage stability of the solution may be deteriorated. The term “solid content” as used herein refers to a product obtained by removing the solvent from the liquid crystal aligning agent. Further, the concentration of the polyamic acid or polyimide used in the liquid crystal alignment treatment agent using the diamine compound of the present invention is not particularly limited, but is preferably 1% by mass or more from the viewpoint of the characteristics of the obtained liquid crystal alignment film, More preferably, it is 3 mass% or more, and especially 5 mass% or more.
The liquid crystal alignment treatment agent obtained as described above is preferably filtered before being applied to the substrate.

<Liquid crystal display element>
The liquid crystal aligning agent using the diamine compound of the present invention can be applied to a substrate, dried and fired to form a coating film. By rubbing this coating surface, a liquid crystal alignment film for rubbing Used as. It is also used as a liquid crystal alignment film for VA (for vertical alignment) and a photo-alignment film that are not rubbed.
In this case, the substrate to be used is not particularly limited as long as it is a highly transparent substrate. A glass substrate, an acrylic substrate, a plastic substrate such as a polycarbonate substrate, or the like can be used, and an ITO electrode for driving a liquid crystal is formed. It is preferable to use a new substrate from the viewpoint of simplification of 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.
Examples of the method for applying the liquid crystal aligning agent include spin coating, printing, and ink jet methods. From the viewpoint of productivity, the flexographic printing method is widely used industrially, and the diamine compound of the present invention is used. The liquid crystal aligning agent used is also preferably used.
The drying process after applying the liquid crystal alignment treatment agent is not necessarily required, but if the time from application to baking is not constant for each substrate, or if baking is not performed immediately after application, the drying process is performed. It is preferable to include. The drying is not particularly limited as long as the solvent is evaporated to such an extent that the shape of the coating film is not deformed by transporting the substrate or the like. For example, a method of drying on a hot plate at 50 to 150 ° C., preferably 80 to 120 ° C. for 0.5 to 30 minutes, preferably 1 to 5 minutes can be mentioned.

The substrate coated with the liquid crystal aligning agent is preferably baked at an arbitrary temperature of 100 to 350 ° C, more preferably 150 to 300 ° C, and further preferably 180 to 250 ° C. When an amic acid group is present in the liquid crystal aligning agent, the conversion rate from the amic acid to the imide varies depending on the firing temperature, but the liquid crystal aligning agent using the diamine compound of the present invention is not necessarily 100% imide. It is not necessary to make it.
The thickness of the coating film after baking is disadvantageous in terms of power consumption of the liquid crystal display element if it is too thick, and if it is too thin, the reliability of the liquid crystal display element may be lowered, so it is preferably 10 to 200 nm, more preferably 50-100 nm.
An existing rubbing apparatus can be used for rubbing the coating surface formed on the substrate as described above. Examples of the material of the rubbing cloth at this time include cotton, rayon, and nylon.
A substrate with a liquid crystal alignment film obtained by the above method can be used as a liquid crystal display element by preparing a liquid crystal cell by a known method. To give an example of liquid crystal cell production, a pair of substrates on which a liquid crystal alignment film is formed is preferably an arbitrary rubbing direction of 0 to 270 ° with a spacer of preferably 1 to 30 μm, more preferably 2 to 10 μm. A method is generally used in which the angle is set to be fixed, the periphery is fixed with a sealant, and liquid crystal is injected and sealed. The method for encapsulating liquid crystal is not particularly limited, and examples thereof include a vacuum method in which liquid crystal is injected after reducing the pressure inside the produced liquid crystal cell, and an dropping (ODF) method in which liquid crystal is dropped and then sealed.
The liquid crystal display element thus obtained includes a TN liquid crystal display element, an STN liquid crystal display element, a TFT liquid crystal display element, an OCB liquid crystal display element, a lateral electric field type (IPS) liquid crystal display element, a VA liquid crystal display element, and the like. It is suitably used for display elements by various methods.

  The present invention will be described in more detail with reference to the following examples, but the present invention should not be construed as being limited thereto.

Synthesis Example 1 Synthesis of 3,5-diaminobenzylfuran-2-carboxylate In a 500 mL (milliliter) three-necked flask, 25.0 g of 1,3-dinitrobenzyl alcohol, 10.5 mL of 2-furoyl chloride, and tetrahydrofuran 300 mL was added. Furthermore, 9.0 mL of pyridine was added dropwise and stirred at room temperature for 25 hours. After completion of the reaction, 50 mL of pure water was added and stirred for 1 hour. Ethyl acetate was added to extract the organic layer, and the organic layer was washed with 1N hydrochloric acid, saturated aqueous sodium hydrogen carbonate, and saturated brine. Subsequently, anhydrous magnesium sulfate was added to the organic layer, dehydrated and dried, filtered, and then the solvent was distilled off using a rotary evaporator. The residue was recrystallized using tetrahydrofuran / hexane = 1/3 (volume ratio, hereinafter the same) to obtain 27.5 g of milky white solid (yield 93%). The measurement result of ¹ H-NMR of this milky white solid is shown below. From this result, it was confirmed that the obtained solid was the target dinitro compound. ¹ H-NMR means a nuclear magnetic resonance spectrum of an intramolecular hydrogen atom.
¹ H NMR (400 MHz, CDCl ₃ ): δ 9.04 (t, 1H), 8.66-8.63 (m, 2H), 7.65 (dd, 1H), 7.32 (dd, 1H) , 6.58 (dd, 1H), 5.53 (s, 2H)

Next, 23.8 g of a dinitro compound, 2.4 g of platinum / carbon (mass ratio is 1/10, hereinafter the same) and 239 g of methanol were added to a 500 mL four-necked flask and stirred for 43 hours in a hydrogen atmosphere. After completion of the reaction, celite filtration was performed, and the solvent was distilled off using a rotary evaporator. The residue was recrystallized from isopropyl alcohol to obtain 16.1 g of a light orange solid (yield 85%).
The measurement result of ¹ H-NMR of this light brown solid is shown below. From this result, it was confirmed that the obtained light orange solid was the target diamine.
¹ H NMR (400 MHz, CDCl ₃ ): δ 7.58 (dd, 1H), 7.21 (dd, 1H), 6.51 (dd, 1H), 6.18 (dt, 2H), 6.00 (T, 1H), 5.16 (s, 2H), 3.62 (br, 4H)

(Synthesis Example 2) Synthesis of furan-2-ylmethyl 3,5-diaminobenzoate To a 500 mL four-necked flask, 25.3 g of 3,5-dinitrobenzoyl chloride, 10.0 mL of furfuryl alcohol, and 200 mL of tetrahydrofuran were added. Further, 9.7 mL of pyridine was added dropwise and stirred at room temperature for 16 hours. After completion of the reaction, 50 mL of pure water was added and stirred for 1 hour. Ethyl acetate was added to extract the organic layer, and the organic layer was washed with 1N hydrochloric acid, saturated aqueous sodium hydrogen carbonate, and saturated brine. Anhydrous magnesium sulfate was added to the organic layer, dehydrated and dried, filtered, and then the solvent was distilled off using a rotary evaporator. The residue was purified by silica gel column chromatography (distillation solvent was a mixed solvent of hexane: ethyl acetate = 3: 1) to obtain 30.3 g of a dinitro compound (yield 95%). The result of ¹ H-NMR measurement of the obtained solid is shown below. From this result, it was confirmed that the obtained solid was the target dinitro compound.
¹ H NMR (400 MHz, CDCl ₃ ): δ 9.23 (t, 1H), 9.17 (d, 2H), 7.49 (dd, 1H), 6.57 (dd, 1H), 6.43 (Dd, 1H), 5.44 (s, 2H)

To a 500 mL four-necked flask, 30.3 g of a dinitro compound, 3.1 g of platinum / carbon, and 400 mL of methanol were added and stirred at room temperature in a hydrogen atmosphere. After completion of the reaction, celite filtration was performed, and the solvent was distilled off using a rotary evaporator. The residue was recrystallized using isopropyl alcohol / hexane = 1/1 to obtain 11.6 g of a light brown solid (yield 48%).
The measurement result of ¹ H NMR of this light brown solid is shown below. From this result, it was confirmed that the obtained light brown solid was the target diamine.
¹ H NMR (400 MHz, DMSO-d ₆ ): δ 7.71 (dd, 1H), 6.57 (dd, 1H), 6.48 (dd, 2H), 6.41 (d, 2H), 6 .01 (t, 1H), 5.20 (s, 2H), 5.02 (br, 4H)

(Synthesis Example 3) Synthesis of N- (3,5-diaminophenyl) furan-2-carboxamide To a 500 mL three-necked flask, 24.1 g of 3,5-dinitroaniline, 11.7 mL of pyridine, and 300 mL of tetrahydrofuran were added. -13.8 mL of furoyl chloride was added dropwise and stirred at room temperature for 18 hours. After completion of the reaction, 50 mL of pure water was added and stirred for 1 hour. Ethyl acetate was added to extract the organic layer, and the organic layer was washed with 1N hydrochloric acid, saturated aqueous sodium hydrogen carbonate, and saturated brine. Anhydrous magnesium sulfate was added to the organic layer, dehydrated and dried, filtered, and then the solvent was distilled off using a rotary evaporator. The residue was recrystallized using tetrahydrofuran / hexane = 1/3 to obtain 31.1 g of a dinitro compound (yield 85%). The measurement result of ¹ H-NMR of the obtained solid is shown below. From this result, it was confirmed that the obtained solid was the target dinitro compound.
¹ H NMR (400 MHz, DMSO-d ₆ ): δ 11.1 (s, 1H), 9.11 (d, 2H), 8.54 (t, 1H), 8.05 (dd, 1H), 7 .46 (dd, 1H), 6.78 (dd, 1H)

To a 1 L four-necked flask were added 30.9 g of a dinitro compound, 4.2 g of platinum / carbon, 300 g of 1,4-dioxane, and 800 g of tetrahydrofuran, and the mixture was stirred at room temperature in a hydrogen atmosphere. After completion of the reaction, celite filtration was performed, and the solvent was distilled off using a rotary evaporator. The residue was recrystallized from isopropyl alcohol to obtain 21.4 g of a light brown solid (yield 89%).
The measurement result of ¹ H NMR of this light brown solid is shown below. From this result, it was confirmed that the obtained light brown solid was the target diamine.
¹ H NMR (400 MHz, DMSO-d ₆ ): δ9.51 (s, 1H), 7.87 (dd, 1H), 7.28 (dd, 1H), 6.65 (dd, 1H), 6 .23 (d, 2H), 5.60 (t, 1H), 4.73 (br, 4H)

（合成例４）３,５−ジアミノベンジルチオフェン−２−カルボキシレート（ＤＡＢＴｈ）の合成
５００ｍＬ三口フラスコに、３，５−ジニトロベンジルアルコール２１．５ｇ、２−テノイルクロリド１２．１ｍＬ、及びテトラヒドロフラン２００ｍＬを加えた。ピリジン９．６ｍＬを滴下し、室温で４８時間攪拌した。反応終了後、純水５０ｍＬを加え１時間攪拌した。酢酸エチルを加えて有機層を抽出し、有機層を１Ｎ塩酸、飽和重曹水、飽和食塩水で洗浄した。有機層に無水硫酸マグネシウムを加えて脱水乾燥し、ろ過した後に、ロータリーエバポレーターを用いて溶媒留去を行った。酢酸エチルとヘキサンを用いて残渣の再結晶を行い、２７．５ｇのジニトロ化合物を得た（収率８２％）。以下に得られた固体の^１Ｈ ＮＭＲの測定結果を示す。
^１Ｈ ＮＭＲ (４００ ＭＨｚ, ＣＤＣｌ_３):δ９．０３(ｔ, １Ｈ), ８．６６-８．６３ (ｍ, ２Ｈ), ７．９０(ｄｄ, １Ｈ), ７．６６ (ｄｄ, １Ｈ), ７．１７ (ｄｄ, １Ｈ), ５．５２ (ｓ, ２Ｈ)

(Synthesis Example 4) Synthesis of 3,5-diaminobenzylthiophene-2-carboxylate (DABTh) In a 500 mL three-necked flask, 21.5 g of 3,5-dinitrobenzyl alcohol, 12.1 mL of 2-thenoyl chloride, and 200 mL of tetrahydrofuran Was added. 9.6 mL of pyridine was added dropwise and stirred at room temperature for 48 hours. After completion of the reaction, 50 mL of pure water was added and stirred for 1 hour. Ethyl acetate was added to extract the organic layer, and the organic layer was washed with 1N hydrochloric acid, saturated aqueous sodium hydrogen carbonate, and saturated brine. Anhydrous magnesium sulfate was added to the organic layer, dehydrated and dried, filtered, and then the solvent was distilled off using a rotary evaporator. The residue was recrystallized using ethyl acetate and hexane to obtain 27.5 g of a dinitro compound (yield 82%). The measurement results of ¹ H NMR of the obtained solid are shown below.
¹ H NMR (400 MHz, CDCl ₃ ): δ 9.03 (t, 1H), 8.66-8.63 (m, 2H), 7.90 (dd, 1H), 7.66 (dd, 1H) , 7.17 (dd, 1H), 5.52 (s, 2H)

５００mＬ四口フラスコに、ジニトロ化合物１７．５ｇ、白金／カーボン４．３ｇ、及びテトラヒドロフラン２００ｇを加え、水素雰囲気下４８時間攪拌した。反応終了後、セライトろ過を行い、ロータリーエバポレーターを用いて溶媒留去を行った。テトラヒドロフランとイソプロピルアルコールを用いて残渣の再結晶を行い、薄茶色固体を１２．９ｇ得た（収率９２％）。
この薄茶色固体の^１Ｈ ＮＭＲの測定結果を以下に示す。この結果から、得られた薄茶色固体が、目的のジアミンであることを確認した。
^１Ｈ ＮＭＲ (４００ ＭＨｚ, ＣＤＣｌ_３):δ７．８３(ｄｄ, １Ｈ), ７．５６ (ｄｄ, １Ｈ), ７．１０ (ｄｄ, １Ｈ), ６．１９-６．１７ (ｍ, ２Ｈ), ６．００ (ｔ, １Ｈ), ５．１６ (ｓ, ２Ｈ), ３．６１ (ｂｒ, ４Ｈ)

To a 500 mL four-necked flask, 17.5 g of a dinitro compound, 4.3 g of platinum / carbon, and 200 g of tetrahydrofuran were added and stirred for 48 hours in a hydrogen atmosphere. After completion of the reaction, the mixture was filtered through Celite, and the solvent was distilled off using a rotary evaporator. The residue was recrystallized using tetrahydrofuran and isopropyl alcohol to obtain 12.9 g of a light brown solid (yield 92%).
The measurement result of ¹ H NMR of this light brown solid is shown below. From this result, it was confirmed that the obtained light brown solid was the target diamine.
¹ H NMR (400 MHz, CDCl ₃ ): δ 7.83 (dd, 1H), 7.56 (dd, 1H), 7.10 (dd, 1H), 6.19-6.17 (m, 2H) , 6.00 (t, 1H), 5.16 (s, 2H), 3.61 (br, 4H)

(合成例５) ３,５-ジアミノベンジル−５−メチルフラン−２−カルボキシレート（ＭｅＤＡＢＦｒ）の合成
５００ｍＬ四口フラスコに５−メチル−２−フランカルボン酸８．５ｇ、及びジクロロメタン１７０ｍLを加え、室温から０℃に冷却した。次いで、二塩化オキラリル５．９ｍL、及びＤＭＦ０．５ｇを加え、室温で２時間攪拌した。攪拌後、３，５−ジニトロベンジルアルコール１３．４ｇ、及びピリジン６ｍLを加え、室温で１６時間攪拌した。反応終了後、純水５０ｍＬを加え１時間攪拌した。次いで、酢酸エチルを加えて有機層を抽出し、有機層を１Ｎ塩酸、飽和重曹水、飽和食塩水で洗浄した。有機層に無水硫酸マグネシウムを加えて脱水乾燥し、セライトでろ過した後に、ロータリーエバポレーターを用いて溶媒留去を行った。イソプロピルアルコールを用いて残渣を洗浄し、１７．１ｇのジニトロ化合物を得た（収率８６％）。以下に得られた固体の^１Ｈ ＮＭＲの測定結果を示す。
^１Ｈ ＮＭＲ (４００ ＭＨｚ, ＣＤＣｌ_３):δ９．０２ (ｔ, １Ｈ), ８．６５-８．６２ (ｍ, ２Ｈ), ７．２３-７．２１ (ｍ, １Ｈ), ６．２０-６．１８ (ｍ, １Ｈ), ５．５２-５．５０ (ｍ, ２Ｈ), ２．４３-２．４１ (ｍ, ３Ｈ)

Synthesis Example 5 Synthesis of 3,5-diaminobenzyl-5-methylfuran-2-carboxylate (MeDABFr) 8.5 g of 5-methyl-2-furancarboxylic acid and 170 mL of dichloromethane were added to a 500 mL four-necked flask. Cooled from room temperature to 0 ° C. Next, 5.9 mL of oxalyl dichloride and 0.5 g of DMF were added, and the mixture was stirred at room temperature for 2 hours. After stirring, 13.4 g of 3,5-dinitrobenzyl alcohol and 6 mL of pyridine were added and stirred at room temperature for 16 hours. After completion of the reaction, 50 mL of pure water was added and stirred for 1 hour. Next, ethyl acetate was added to extract the organic layer, and the organic layer was washed with 1N hydrochloric acid, saturated aqueous sodium hydrogen carbonate, and saturated brine. Anhydrous magnesium sulfate was added to the organic layer, dehydrated and dried, filtered through celite, and then the solvent was distilled off using a rotary evaporator. The residue was washed with isopropyl alcohol to obtain 17.1 g of a dinitro compound (yield 86%). The measurement results of ¹ H NMR of the obtained solid are shown below.
¹ H NMR (400 MHz, CDCl ₃ ): δ 9.02 (t, 1H), 8.65-8.62 (m, 2H), 7.23-7.21 (m, 1H), 6.20- 6.18 (m, 1H), 5.52-5.50 (m, 2H), 2.44-2.41 (m, 3H)

５００mＬ四口フラスコに、ジニトロ化合物１６．７ｇ、白金／カーボン１．７ｇ、及びテトラヒドロフラン１７０ｇを加え、水素雰囲気下２１時間攪拌した。反応終了後、セライトろ過を行い、ロータリーエバポレーターを用いて溶媒留去を行った。イソプロピルアルコールを用いて残渣の再結晶を行い、薄茶色固体を９．１ｇ得た（収率６８％）。
この薄茶色固体の^１Ｈ ＮＭＲの測定結果を以下に示す。この結果から、得られた薄茶色固体が、目的とするジアミンであることを確認した。
^１Ｈ ＮＭＲ (４００ ＭＨｚ, ＣＤＣｌ_３):δ７．１５ (ｄ, ２Ｈ),７．１０ (ｄ, １Ｈ), ６．１１-６．０９ (ｍ, １Ｈ), ５．９７ (ｔ, １Ｈ), ５．１３ (ｓ, ２Ｈ), ３．５７ (ｂｒ, ４Ｈ), ２．３７ (ｓ, ３Ｈ)

To a 500 mL four-necked flask, 16.7 g of a dinitro compound, 1.7 g of platinum / carbon, and 170 g of tetrahydrofuran were added and stirred for 21 hours in a hydrogen atmosphere. After completion of the reaction, the mixture was filtered through Celite, and the solvent was distilled off using a rotary evaporator. The residue was recrystallized using isopropyl alcohol to obtain 9.1 g of a light brown solid (68% yield).
The measurement result of ¹ H NMR of this light brown solid is shown below. From this result, it was confirmed that the obtained light brown solid was the target diamine.
¹ H NMR (400 MHz, CDCl ₃ ): δ 7.15 (d, 2H), 7.10 (d, 1H), 6.11-6.09 (m, 1H), 5.97 (t, 1H) , 5.13 (s, 2H), 3.57 (br, 4H), 2.37 (s, 3H)

（合成例６）３,５−ジアミノベンジル フラン−３−カルボキシレート（３−ＤＡＢＦｒ）の合成
５００ｍＬ四口フラスコに３−フランカルボン酸８．２ｇ、及びジクロロメタン２４０ｍLを加え、室温から０℃に冷却した。次いで、二塩化オキラリル６．４ｍL、及びＤＭＦ０．５ｇを加え、室温で２時間攪拌した。攪拌後、３，５−ジニトロベンジルアルコール１５．０ｇ、及びピリジン９．７ｍLを加え、室温で４７時間攪拌した。反応終了後、純水５０ｍＬを加え１時間攪拌した。次いで、酢酸エチルを加えて有機層を抽出し、有機層を１Ｎ塩酸、飽和重曹水、飽和食塩水で洗浄した。有機層に無水硫酸マグネシウムを加えて脱水乾燥し、ろ過した後に、ロータリーエバポレーターを用いて溶媒留去を行った。酢酸エチルを用いて残渣の再結晶を行い、１６．８ｇのジニトロ化合物を得た（収率７８％）。以下に得られた固体の^１Ｈ ＮＭＲの測定結果を示す。
^１Ｈ ＮＭＲ (４００ ＭＨｚ, ＣＤＣｌ_３):δ９．０３(ｔ, １Ｈ), ８．６３-８．６１ (ｍ, ２Ｈ), ８．１２ (ｄｄ, １Ｈ), ７．４１ (ｄｄ, １Ｈ), ６．７９ (ｄｄ, １Ｈ), ５．４８(ｄ, ２Ｈ)

(Synthesis Example 6) Synthesis of 3,5-diaminobenzyl furan-3-carboxylate (3-DABFr) To a 500 mL four-necked flask, 8.2 g of 3-furancarboxylic acid and 240 mL of dichloromethane were added, and cooled from room temperature to 0 ° C. did. Next, 6.4 mL of oxalyl dichloride and 0.5 g of DMF were added, and the mixture was stirred at room temperature for 2 hours. After stirring, 15.0 g of 3,5-dinitrobenzyl alcohol and 9.7 mL of pyridine were added, and the mixture was stirred at room temperature for 47 hours. After completion of the reaction, 50 mL of pure water was added and stirred for 1 hour. Next, ethyl acetate was added to extract the organic layer, and the organic layer was washed with 1N hydrochloric acid, saturated aqueous sodium hydrogen carbonate, and saturated brine. Anhydrous magnesium sulfate was added to the organic layer, dehydrated and dried, filtered, and then the solvent was distilled off using a rotary evaporator. The residue was recrystallized using ethyl acetate to obtain 16.8 g of a dinitro compound (yield 78%). The measurement results of ¹ H NMR of the obtained solid are shown below.
¹ H NMR (400 MHz, CDCl ₃ ): δ 9.03 (t, 1H), 8.63-8.61 (m, 2H), 8.12 (dd, 1H), 7.41 (dd, 1H) , 6.79 (dd, 1H), 5.48 (d, 2H)

５００mＬ四口フラスコに、ジニトロ化合物１６．５ｇ、白金／カーボン１．７ｇ、及びテトラヒドロフラン１６５ｇを加え、水素雰囲気下２９時間攪拌した。反応終了後、セライトろ過を行い、ロータリーエバポレーターを用いて溶媒留去を行った。テトラヒドロフランとイソプロピルアルコールを用いて残渣の再結晶を行い、薄茶色固体を７．４ｇ得た（収率５７％）。
この薄茶色固体の^１Ｈ ＮＭＲの測定結果を以下に示す。この結果から、得られた薄茶色固体が目的のジアミンであることを確認した。
^１Ｈ ＮＭＲ (４００ ＭＨｚ, ＣＤＣｌ_３):δ８．０４ (ｄｄ, １Ｈ), ７．４２ (ｄｄ, １Ｈ), ６．７７ (ｄｄ, １Ｈ), ６．１４ (ｄ, ２Ｈ), ５．９８ (ｔ, １Ｈ), ５．１０ (ｓ, ２Ｈ), ３．５７ (ｂｒ, ４Ｈ)

To a 500 mL four-necked flask, 16.5 g of a dinitro compound, 1.7 g of platinum / carbon, and 165 g of tetrahydrofuran were added and stirred for 29 hours in a hydrogen atmosphere. After completion of the reaction, the mixture was filtered through Celite, and the solvent was distilled off using a rotary evaporator. The residue was recrystallized using tetrahydrofuran and isopropyl alcohol to obtain 7.4 g of a light brown solid (yield 57%).
The measurement result of ¹ H NMR of this light brown solid is shown below. From this result, it was confirmed that the obtained light brown solid was the target diamine.
¹ H NMR (400 MHz, CDCl ₃ ): δ 8.04 (dd, 1H), 7.42 (dd, 1H), 6.77 (dd, 1H), 6.14 (d, 2H), 5.98 (t, 1H), 5.10 (s, 2H), 3.57 (br, 4H)

The abbreviations of the compounds used for the synthesis of polyamic acid and polyimide are as follows.
<Tetracarboxylic dianhydride>
CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride TDA: 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride <diamine>
2-DABFr: 3,5-diaminobenzylfuran-2-carboxylate FrDAB: furan-2-ylmethyl 3,5-diaminobenzoate DAAFr: N- (3,5-diaminophenyl) furan-2-carboxamide DABTh: 3, 5-Diaminobenzyl thiophene-2-carboxylate MeDABFr: 3,5-diaminobenzyl-5-methylfuran-2-carboxylate 3-DABFr: 3,5-diaminobenzyl furan-3-carboxylate Me4APhA: 4-amino- N-methylphenethylamine p-PDA: p-phenylenediamine DDM: 4,4′-diaminodiphenylmethane C14DAB: 4-tetradecyloxy-1,3-diaminobenzene C16DAB: 4-hexadecyloxy-1,3-diaminobenzene 3 − BA: 3- aminobenzyl amine <Organic solvent>
NMP: N-methyl-2-pyrrolidone γ-BL: γ-butyrolactone BC: butyl cellosolve DPM: dipropylene glycol monomethyl ether DMF: dimethylformamide

<Measurement of molecular weight>
The molecular weight of the polyamic acid or polyimide obtained by the polymerization reaction was measured with a GPC (room temperature gel permeation chromatography) apparatus, and the number average molecular weight and 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 additives, lithium bromide-hydrate (LiBr.H2O) is 30 mmol / L, phosphoric acid / anhydrous crystal (o-phosphoric acid) is 30 mmol / L, tetrahydrofuran (THF ) Is 10ml / L)
Flow rate: 1.0 ml / min Standard sample for preparing calibration curve: TSK standard polyethylene oxide (molecular weight: about 900,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation and polyethylene glycol (molecular weight: about 12,000, 4,000, 1,000) manufactured by Polymer Laboratories .

<Measurement of imidization ratio>
The imidation ratio of the polyimide obtained by chemical imidation was determined by dissolving the polyimide in d6-DMSO (dimethyl sulfoxide-d6), measuring ¹ H-NMR, and remaining the amic acid group without imidization. The ratio was calculated from the ratio of the integrated values of proton peaks.

<Production of liquid crystal cell>
About the liquid-crystal aligning agent prepared by the Example, the reference example, and the comparative example, the liquid crystal cell was produced as follows.
A liquid crystal alignment treatment agent is spin-coated on a glass substrate with a transparent electrode, dried on a 70 ° C. hot plate for 70 seconds, and then baked on a 210 ° C. hot plate for 10 minutes to form a coating film having a thickness of 100 nm. I let you. This coating film surface was rubbed with a rubbing apparatus having a roll diameter of 120 mm using a rayon cloth under the conditions of a roll rotation speed of 1000 rpm, a roll traveling speed of 50 mm / sec, and an indentation amount of 0.3 mm to obtain a substrate with a liquid crystal alignment film. Prepare two substrates with a liquid crystal alignment film, spray a 6μm spacer on the surface of one liquid crystal alignment film, print a sealant on it, and face the other substrate with the liquid crystal alignment film surface After the lamination so that the rubbing direction was orthogonal, the sealing agent was cured to produce an empty cell. Liquid crystal MLC-2003 (manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain a twist nematic liquid crystal cell.
A method for measuring physical properties and evaluating characteristics of each liquid crystal cell produced was described below.
The results of the composition of each liquid crystal alignment treatment agent in Examples 1 and 2, Reference Examples 1 to 14 and Comparative Examples 1 to 3, measurement of physical properties of each liquid crystal alignment film, and evaluation of characteristics are shown in Table 2. The results are shown in Table 3.

<Rubbing resistance evaluation>
A substrate with a liquid crystal alignment film was prepared by the method described in <Preparation of Liquid Crystal Cell> above. At that time, the pressing amount of rubbing conditions was changed to 0.5 mm. The obtained liquid crystal alignment film surface was observed with the confocal laser microscope, and the following evaluation was performed.
○: Scraping and rubbing scratches are not observed.
Δ: Scraping and rubbing scratches are observed.
X: A film | membrane peels or a rubbing damage | wound is observed visually.

<Liquid crystal orientation evaluation>
In order to highlight the superiority or inferiority of the liquid crystal orientation, the following liquid crystal cell was produced. A liquid crystal alignment treatment agent is spin-coated on a glass substrate with a transparent electrode, dried on a 70 ° C. hot plate for 70 seconds, and then baked on a 210 ° C. hot plate for 10 minutes to form a coating film having a thickness of 100 nm. I let you. The surface of the coating film was rubbed with a rubbing apparatus having a roll diameter of 120 mm using a rayon cloth under the conditions of a roll rotation speed of 1000 rpm, a roll traveling speed of 50 mm / sec, and an indentation amount of 0.2 mm to obtain a substrate with a liquid crystal alignment film. Prepare two substrates with the above-mentioned liquid crystal alignment film, spray a spacer of 6 μm on the surface of one liquid crystal alignment film, print a sealant on the surface, and attach the other substrate to the liquid crystal alignment film surface. Were bonded so that the rubbing direction was 180 °, and then the sealing agent was cured to produce an empty cell. Liquid crystal MLC-2003 (manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method, and the inlet was sealed to obtain an antiparallel liquid crystal cell. The initial alignment of the liquid crystal cell was visually observed. Evaluation was performed as follows. The results are shown in Table 2 described later.
○: Oriented well.
X: Many light omissions and poor alignment positions are observed.

<Pretilt angle measurement>
The twisted nematic liquid crystal cell produced by the method described in <Preparation of liquid crystal cell> was heated at 105 ° C. for 5 minutes, and then the pretilt angle and the voltage holding ratio were measured. The pretilt angle was measured using a crystal rotation method.

<Measurement of voltage holding ratio>
The voltage holding ratio of the twisted nematic liquid crystal cell manufactured by the method described in <Preparation of liquid crystal cell> is measured by applying a voltage of 4 V for 60 μs at a temperature of 90 ° C., and measuring the voltage after 16.67 ms. Then, how much voltage can be held was calculated as a voltage holding ratio. For measuring the voltage holding ratio, a VHR-1 voltage holding ratio measuring device manufactured by Toyo Corporation was used.

<Measurement of accumulated charge (RDC)>
A DC voltage is applied to the twisted nematic liquid crystal cell produced by the method described in <Preparation of liquid crystal cell> at a temperature of 23 ° C. up to 1.0 V at intervals of 0 V to 0.1 V, and the flicker amplitude level at each voltage is applied. And a calibration curve was created. After grounding for 5 minutes, after applying AC voltage 3.0V and DC voltage 5.0V for 1 hour, measure the flicker amplitude level immediately after setting only DC voltage to 0V, and estimate RDC by comparing with the calibration curve prepared in advance. It was. (This RDC estimation method is called a flicker reference method.)

( Reference Example 1)
Using 5.00 g (0.025 mol) of CBDA as the tetracarboxylic dianhydride component and 6.03 g (0.026 mol) of 2-DABFr as the diamine component, the reaction was allowed to react in NMP 44.14 g at room temperature for 16 hours. A solution having a concentration of 20% by mass of acid (PAA-1) was obtained. The polyamic acid (PAA-1) solution 10.0g was diluted using NMP23.3g and BC10.0g, and the liquid crystal aligning agent whose polyamic acid (PAA-1) is 4.6 mass% was obtained. Using this liquid crystal aligning agent, rubbing resistance, pretilt angle, voltage holding ratio (VHR), and RDC were evaluated. The results are shown in Table 2.

( Reference Example 2)
To the polyamic acid (PAA-1) solution (PAA-1 concentration 20 mass%) 40 g obtained in the same manner as in Reference Example 1, 93.33 g of NMP was added for dilution, and 5.77 g of acetic anhydride and 2. 39 g was added and reacted at 40 ° C. for 3 hours to imidize. The reaction solution was cooled to about room temperature and then poured into 500 ml of methanol, and the precipitated solid was recovered. Further, this solid was washed twice with methanol and then dried under reduced pressure at 100 ° C. to obtain a white powder of polyimide (SPI-1). The number average molecular weight of this polyimide was 13,204, and the weight average molecular weight was 30,700. The imidation ratio was 87%.
To 2.00 g of the obtained polyimide (SPI-1), 18.0 g of γ-BL was added and stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Furthermore, γ-BL 8.0 g, BC 6.00 g, and DPM 6.00 g were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours to obtain a liquid crystal aligning agent having a polyimide (SPI-1) content of 5 mass%. Evaluation similar to the reference example 1 was performed using this liquid-crystal aligning agent. The results are shown in Table 2.

( Reference Example 3)
As a tetracarboxylic dianhydride component, 5.52 g (0.028 mol) of CBDA, as a diamine component, 2.00 g (0.009 mol) of 2-DABFr, 1.40 g (0.011 mol) of 3-ABA, Then, 2.76 g (0.009 mol) of C14DAB was used and reacted for 16 hours at room temperature in 46.7 g of NMP to obtain a solution having a concentration of 20% by mass of polyamic acid (PAA-2). This polyamic acid (PAA-2) solution 10.0g was diluted using NMP23.3g and BC10.0g, and the liquid crystal aligning agent whose polyamic acid (PAA-2) is 4.6 mass% was obtained. Evaluation similar to the reference example 1 was performed using this liquid-crystal aligning agent. The results are shown in Table 2.

( Reference Example 4)
93.3 g of NMP was added to 40.0 g of the polyamic acid (PAA-2) solution (PAA-2 concentration: 20% by mass) obtained in the same manner as in Reference Example 3 and diluted, and then 6.02 g of acetic anhydride and pyridine were added. 2.49 g was added and reacted at 60 ° C. for 3 hours to imidize. The reaction solution was cooled to about room temperature and then poured into 500 ml of methanol, and the precipitated solid was recovered. Further, this solid was washed twice with methanol and then dried under reduced pressure at 100 ° C. to obtain a white brown powder of polyimide (SPI-2). The number average molecular weight of this polyimide was 15,850, and the weight average molecular weight was 42,234. The imidation ratio was 92%.
Γ-BL18.0g was added to 2.00g of this polyimide (SPI-2), and it stirred at 50 degreeC for 20 hours. The polyimide was completely dissolved at the end of stirring. Furthermore, γ-BL 8.00 g, BC 6.00 g, and DPM 6.00 g were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours to obtain a liquid crystal aligning agent having a polyimide (SPI-2) content of 5 mass%. Evaluation similar to the reference example 1 was performed using this liquid-crystal aligning agent. The results are shown in Table 2.

( Reference Example 5)
As the tetracarboxylic dianhydride component, 5.57 g (0.029 mol) of CBDA, as the diamine component, 2.02 g (0.009 mol) of FrDAB, 1.42 g (0.012 mol) of 3-ABA, and C14DAB Was used in NMP46.7g at room temperature for 16 hours to obtain a polyamic acid (PAA-3) solution having a concentration of 20% by mass.
The polyamic acid (PAA-3) A solution 10.0 g NMP23.3G, and diluted with BC10.0G, polyamic acid (PAA-3) is 4.6 wt% solution, the liquid crystal alignment treating agent Obtained. Evaluation similar to the reference example 1 was performed using this coating liquid. The results are shown in Table 2.

( Reference Example 6)
93.3 g of NMP was added to 40.0 g of the polyamic acid (PAA-3) solution (PAA-3 concentration: 20% by mass) obtained in the same manner as in Reference Example 5 and diluted, and then 6.06 g of acetic anhydride and pyridine were added. 2.53 g was added and reacted at 60 ° C. for 3 hours to imidize. The reaction solution was cooled to about room temperature and then poured into 500 ml of methanol, and the precipitated solid was recovered. Further, this solid was washed twice with methanol and then dried under reduced pressure at 100 ° C. to obtain a white brown powder of polyimide (SPI-3). The number average molecular weight of this polyimide was 17,920, and the weight average molecular weight was 41,290. Further, the imidization ratio was 89%.
Γ-BL 18.0 g was added to 2.00 g of polyimide (SPI-3), and the mixture was stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Furthermore, γ-BL 8.00 g, BC 6.00 g, and DPM 6.00 g were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours to obtain a liquid crystal aligning agent having a polyimide (SPI-3) content of 5 mass%. Evaluation similar to the reference example 1 was performed using this liquid-crystal aligning agent. The results are shown in Table 2.

(Example 1 )
As the tetracarboxylic dianhydride component, 5.57 g (0.029 mol) of CBDA, as the diamine component, 1.89 g (0.009 mol) of DAAFr, 1.42 g (0.012 mol) of 3-ABA, and C14DAB Was used in NMP46.7g at room temperature for 16 hours to obtain a polyamic acid (PAA-4) solution having a concentration of 20% by mass.
Dilute 10.0 g of polyamic acid solution (PAA-4) with 23.3 g of NMP and 10.0 g of BC to make a solution containing 4.6% by mass of polyamic acid (PAA-4) , and use the diamine compound of the present invention . A liquid crystal aligning agent was obtained. Evaluation similar to the reference example 1 was performed using this coating liquid. The results are shown in Table 2.

(Example 2 )
93.3 g of NMP was added to 40.0 g of the polyamic acid (PAA-4) solution (PAA-4 concentration: 20% by mass) obtained in the same manner as in Example 1 and diluted, and then 6.06 g of acetic anhydride and pyridine were added. 2.53 g was added and reacted at 60 ° C. for 3 hours to imidize. The reaction solution was cooled to about room temperature and then poured into 500 ml of methanol, and the precipitated solid was recovered. Further, the solid was washed twice with methanol and then dried under reduced pressure at 100 ° C. to obtain a white brown powder of polyimide (SPI-4). The number average molecular weight of this polyimide was 15,367, and the weight average molecular weight was 39,880. Moreover, the imidation ratio was 90%.
12.0 g of γ-BL was added to 2.00 g of polyimide (SPI-4), and the mixture was stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Furthermore, γ-BL 8.00 g, BC 6.00 g, and DPM 6.00 g were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours to obtain a liquid crystal aligning agent having a polyimide (SPI-4) content of 5 mass%. Evaluation similar to the reference example 1 was performed using this liquid-crystal aligning agent. The results are shown in Table 2.

( Reference Example 7 )
TDA 12.0 g (0.040 mol) as the tetracarboxylic dianhydride component, p-PDA 2.59 g (0.024 mol), 2-DABFr 2.79 g (0.012 mol), and C16DAB 1.39 g (0.004 mol) as the diamine component ) In NMP75.7 g for 24 hours at 50 ° C. to obtain a 20% polyamic acid solution.
To 90.0 g of this polyamic acid solution, 187 g of NMP was added for dilution, and 39.6 g of acetic anhydride and 18.4 g of pyridine were further added and reacted at 40 ° C. for 3 hours to imidize.
The reaction solution was cooled to about room temperature and then poured into 1.17 L of methanol to recover the precipitated solid. Further, the solid was washed twice with methanol and then dried under reduced pressure at 100 ° C. to obtain a white powder of polyimide (SPI-5). The number average molecular weight of this polyimide was 15,322, and the weight average molecular weight was 28,239. The imidation ratio was 81%.
62.5 g of γ-BL was added to 5.00 g of polyimide (SPI-5), and the mixture was stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Further, 20.8 g of γ-BL was added to this solution and stirred at 50 ° C. for 20 hours to prepare a solution having a polyimide (SPI-5) of 5.7% by mass.
On the other hand, 9.80 g (0.050 mol) of CBDA, 9.60 g (0.044 mol) of PMDA, 19.8 g (0.10 mol) of DDM, and a mixed solvent of 111 g of NMP and 111 g of γ-BL, The reaction was carried out at room temperature for 5 hours to prepare a 15% by mass solution of polyamic acid (PAA-5). This polyamic acid had a number average molecular weight of 10,925 and a weight average molecular weight of 27,314.
To 200 g of this polyamic acid (PAA-5) solution, 225 g of γ-BL and 75.0 g of BC were added and stirred at room temperature for 2 hours to obtain a solution containing 6% by mass of polyamic acid (PAA-5). After stirring 200 g of this 6% by weight solution of polyamic acid (PAA-5) and 50.0 g of the 6% by weight solution of polyimide (SPI-5) obtained above at room temperature for 20 hours, solid content (PAA-5 the total mass concentration) was adjusted to be 5.9 wt% of the SPI-5, to obtain liquid crystal alignment treating agent of (BL-1). Evaluation similar to the reference example 1 was performed using this liquid-crystal aligning agent. The results are shown in Table 2.

( Reference Example 8 )
As tetracarboxylic dianhydride component, 5.78 g (0.029 mol) of CBDA, as a diamine component, 2.24 g (0.009 mol) of DABTh, 1.47 g (0.012 mol) of 3-ABA, and C14DAB Was used in NMP 44.96 g at room temperature for 16 hours to obtain a 20% by mass polyamic acid solution (PAA-6).
Polyamic acid solution (PAA-6) NMP23.3g the 10.0 g, diluted with BC10.0G, solids and 4.6 wt% of the solution, to obtain a liquid crystal aligning agent. Evaluation similar to the reference example 1 was performed using this coating liquid. The results are shown in Table 2.

( Reference Example 9 )
To the polyamic acid (PAA-6) solution (PAA-7 concentration 20 mass%) 40 g obtained in the same manner as in Reference Example 8 , 93.33 g of NMP was added for dilution, and 5.61 g of acetic anhydride and pyridine 2. 32 g was added and reacted at 60 ° C. for 3 hours to imidize. The reaction solution was cooled to about room temperature and then poured into 500 ml of methanol, and the precipitated solid was recovered. Further, the solid was washed several times with methanol and then dried under reduced pressure at 100 ° C. to obtain a white powder of polyimide (SPI-6). The number average molecular weight of this polyimide was 13,163, and the weight average molecular weight was 30,211. Moreover, the imidation ratio was 85%.
12.0 g of γ-BL was added to 2.00 g of polyimide (SPI-7), and the mixture was stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Further, γ-BL8.0g to this solution, BC6.00G, and DPM6.00g was added and stirred for 20 hours at 50 ° C., polyimide (SPI-6) is a 5 wt% solution, the liquid crystal alignment treating agent Obtained. Evaluation similar to the reference example 1 was performed using this coating liquid. The results are shown in Table 2.

( Reference Example 10 )
As a tetracarboxylic dianhydride component, 5.57 g (0.029 mol) of CBDA, 2.14 g (0.009 mol) of MeDABFr, 1.42 g (0.012 mol) of 3-ABA, and C14DAB as a diamine component Was used in NMP46.7g at room temperature for 16 hours to obtain a polyamic acid (PAA-7) solution having a concentration of 20% by mass.
The polyamic acid (PAA-7) A solution 10.0 g NMP23.3G, and diluted with BC10.0G, polyamic acid (PAA-7) is 4.6 wt% solution, the liquid crystal alignment treating agent Obtained. Evaluation similar to the reference example 1 was performed using this coating liquid. The results are shown in Table 2.

( Reference Example 11 )
93.3 g of NMP was added to 40.0 g of a polyamic acid (PAA-7) solution (PAA-7 concentration: 20% by mass) obtained in the same manner as in Reference Example 10 to dilute, and then 6.06 g of acetic anhydride and pyridine were added. 2.53 g was added and reacted at 60 ° C. for 3 hours to imidize. The reaction solution was cooled to about room temperature and then poured into 500 ml of methanol, and the precipitated solid was recovered. Further, the solid was washed twice with methanol and then dried under reduced pressure at 100 ° C. to obtain a white brown powder of polyimide (SPI-7). The number average molecular weight of this polyimide was 15,787, and the weight average molecular weight was 36,433. The imidation ratio was 87%.
12.0 g of γ-BL was added to 2.00 g of polyimide (SPI-7), and the mixture was stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Furthermore, γ-BL 8.00 g, BC 6.00 g, and DPM 6.00 g were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours to obtain a liquid crystal alignment agent having a polyimide (SPI-7) content of 5 mass%. Evaluation similar to the reference example 1 was performed using this liquid-crystal aligning agent. The results are shown in Table 2.

( Reference Example 12 )
As a tetracarboxylic dianhydride component, 5.57 g (0.029 mol) of CBDA, as a diamine component, 2.02 g (0.009 mol) of 3-DABFr, 1.42 g (0.012 mol) of 3-ABA, Then, 2.79 g (0.009 mol) of C14DAB was used and reacted at room temperature for 16 hours in 46.7 g of NMP to obtain a solution having a concentration of 20% by mass of polyamic acid (PAA-8).
The polyamic acid (PAA-8) A solution 10.0 g NMP23.3G, and diluted with BC10.0G, polyamic acid (PAA-8) is 4.6 wt% solution, the liquid crystal alignment treating agent Obtained. Evaluation similar to the reference example 1 was performed using this coating liquid. The results are shown in Table 2.

( Reference Example 13 )
93.3 g of NMP was added to 40.0 g of a polyamic acid (PAA-8) solution (PAA-8 concentration: 20% by mass) obtained in the same manner as in Reference Example 12 to dilute, and then 6.06 g of acetic anhydride and pyridine were added. 2.53 g was added and reacted at 60 ° C. for 3 hours to imidize. The reaction solution was cooled to about room temperature and then poured into 500 ml of methanol, and the precipitated solid was recovered. Further, this solid was washed twice with methanol and then dried under reduced pressure at 100 ° C. to obtain a white brown powder of polyimide (SPI-8). The number average molecular weight of this polyimide was 16,142, and the weight average molecular weight was 38,574. Further, the imidization ratio was 89%.
Γ-BL 18.0 g was added to 2.00 g of polyimide (SPI-8), and the mixture was stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Furthermore, γ-BL 8.00 g, BC 6.00 g, and DPM 6.00 g were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours to obtain a liquid crystal aligning agent containing 5% by mass of polyimide (SPI-8). Evaluation similar to the reference example 1 was performed using this liquid-crystal aligning agent. The results are shown in Table 2.

( Reference Example 14 )
As the tetracarboxylic dianhydride component, 5.57 g (0.029 mol) of CBDA, 2.02 g (0.009 mol) of 2-DABFr, and 3.05 g (0.021 mol) of Me4APhA were used as the diamine component. Reaction was performed in 46.7 g of NMP at room temperature for 16 hours to obtain a 20% by mass solution of polyamic acid (PAA-9). The number average molecular weight of this polyamic acid was 21,329, and the weight average molecular weight was 45,294.
The polyamic acid (PAA-9) A solution 10.0 g NMP23.3G, and diluted with BC10.0G, polyamic acid (PAA-9) is 4.6 wt% solution, the liquid crystal alignment treating agent Obtained. Evaluation similar to the reference example 1 was performed using this coating liquid. The results are shown in Table 2.

(Comparative Example 1)
As the tetracarboxylic dianhydride component, 12.5 g (0.064 mol) of CBDA, 5.56 g (0.046 mol) of 3-ABA and 6.25 g (0.020 mol) of C14DAB were used as the diamine component, The reaction was performed in 97.20 g of NMP at room temperature for 16 hours to obtain a 20% by mass solution of polyamic acid (PAA-10).
Dilute 10.0 g of this polyamic acid (PAA-10) with 23.3 g of NMP and 10.0 g of BC to obtain a solution having a polyamic acid (PAA-10) concentration of 4.6% by mass. A liquid crystal alignment treatment agent was obtained. Using this coating solution, a liquid crystal cell was prepared in the same manner as in Reference Example 1, and physical properties were measured and characteristics were evaluated.

(Comparative Example 2)
116.67 g of NMP was added to 50 g of a polyamic acid (PAA-10) solution (PAA-10 concentration 20 mass%) obtained in the same manner as in Comparative Example 1 to dilute, and 7.39 g of acetic anhydride and pyridine 3. 15 g was added and reacted at 70 ° C. for 3 hours for imidization, but gelation occurred during the reaction.
Again, 116.67 g of NMP was added to 50 g of the polyamic acid (PAA-10) solution (PAA-10 concentration: 20% by mass) obtained in the same manner as in Comparative Example 1, and then diluted with 7.39 g of acetic anhydride and pyridine. 3.15 g was added, and imidization was performed at a reaction temperature of 50 ° C.
The reaction solution was cooled to about room temperature and then poured into 250 ml of methanol to recover the precipitated solid. Further, this solid was washed twice with methanol and then dried under reduced pressure at 100 ° C. to obtain a white powder of polyimide (SPI-9). The number average molecular weight of this polyimide was 16,338, and the weight average molecular weight was 39,865. The imidation ratio was 80%.
9 g of γ-BL was added to 1 g of polyimide (SPI-9) and stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Further, 4.0 g of γ-BL, 3.0 g of BC and 3.0 g of DPM were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours to obtain a 5% by mass polyimide (SPI-9) solution. A treating agent was obtained. Using this liquid crystal aligning agent, a liquid crystal cell was prepared in the same manner as in Reference Example 1, and physical properties were measured and characteristics were evaluated.

(Comparative Example 3)
Using 5.70 g (0.029 mol) of CBDA as the tetracarboxylic dianhydride component and 4.51 g (0.030 mol) of Me4APhA as the diamine component, the reaction was carried out at room temperature in 46.7 g of NMP for 16 hours at a polyamic acid ( A solution with a concentration of 20% by mass of PAA-11) was obtained. The number average molecular weight of this polyamic acid was 19,630, and the weight average molecular weight was 48,201.
This polyamic acid (PAA-11) solution 10.0g is diluted with NMP23.3g and BC10.0g, and a polyamic acid (PAA-11) is made into a 4.6 mass% solution, The liquid crystal alignment used as a comparison object A treating agent was obtained. Using this liquid crystal aligning agent, a liquid crystal cell was prepared in the same manner as in Reference Example 1, and physical properties were measured and characteristics were evaluated.

The liquid crystal aligning agent using the diamine compound of the present invention provides 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. can get. Therefore, the liquid crystal display element produced using the liquid-crystal aligning agent using the diamine compound of this invention can be used as a highly reliable liquid crystal display device, TN liquid crystal display element, STN liquid crystal display element, TFT liquid crystal display. It is suitably used for various types of display elements such as elements, VA liquid crystal display elements, IPS liquid crystal display elements, OCB liquid crystal display elements.

Claims (3)

A diamine compound represented by the following formula [2].

(Optional hydrogen atom of the furan ring, rather it may also be substituted with an alkyl group having 1 to 5 carbon atoms, positional relationship between the two amino groups on the benzene ring is meta or para.)   The diamine compound according to claim 1, wherein any hydrogen atom of the furan ring may be substituted with a methyl group.   The polyamic acid obtained by making the diamine component containing the diamine compound of Claim 1 or 2 and the tetracarboxylic dianhydride component react, or the polyimide obtained by imidating this polyamic acid.