JP6249182B2 - Polyimide precursor, polyimide, liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Description

  The present invention relates to a novel diamine, a polyimide precursor and polyimide, a liquid crystal alignment 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. At present, the main liquid crystal alignment films that are industrially used are polyimide precursors such as polyamic acid (also called polyamic acid), polyamic acid esters, and polyimide-based liquid crystal aligning agents composed of polyimide solutions. It is manufactured by applying and forming a film. 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 such liquid crystal display elements, methods such as changing the structure of polyamic acid, polyamic acid ester and polyimide, polyamic acid with different characteristics, blend of polyamic acid ester and polyimide, adding additives, etc. As a result, improvements in liquid crystal alignment and electrical characteristics, control of the pretilt angle, and the like are performed. For example, in order to obtain a high voltage holding ratio, an afterimage is erased by using a polyimide resin having a specific repeating structure (see Patent Document 1) or using a soluble polyimide having a nitrogen atom in addition to an imide group. (Refer to Patent Document 2), and by introducing a 1-phenylindole structure into diamine, which is a raw material of polyamic acid, to reduce residual DC while maintaining a high voltage holding ratio (Patent Various techniques have been proposed, such as Document 3).

  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, problems such as occurrence of printing failure due to deposition and separation due to a long tact time, and burn-in due to accumulated charge (RDC) are problems. It is difficult to solve both of these simultaneously.

JP-A-2-287324 JP-A-10-104633 JP 2010-70537 A

  An object of the present invention is to solve the above-mentioned problems of the prior art, whereby a liquid crystal aligning agent having good printability can be obtained, and the accumulated charge can be reduced and the accumulated charge can be relaxed quickly. It is to provide a diamine, a polyimide precursor and a polyimide, a liquid crystal aligning agent using them, a liquid crystal alignment film, and a liquid crystal display element.

  As a result of intensive studies, the present inventors have achieved that the polyimide precursor and the liquid crystal aligning agent containing polyimide using the specific diamine represented by the following formula [1] as the diamine component achieve the above object. It has been found that it is extremely effective, and the present invention has been completed. In addition, the diamine compound represented by the following formula [1] is a novel compound not described in any literature.

  The novel diamine of the present invention that solves the above problems is represented by the following formula [1].

（式［１］中、Ｒ_１〜Ｒ_９のうち二つは１級アミノ基、残りは水素原子またはアミノ基以外の一価の有機基であり、それぞれ同一でも異なっていてもよい。ｎは１又は２であり、環を形成している飽和炭化水素部の水素原子はハロゲン原子又はアミノ基以外の一価の有機基で置換されていてもよい。）

(In the formula [1], two of R _{1 to} R ₉ are primary amino groups, and the remainder are hydrogen atoms or monovalent organic groups other than amino groups, which may be the same or different. 1 or 2 and the hydrogen atom of the saturated hydrocarbon part forming the ring may be substituted with a monovalent organic group other than a halogen atom or an amino group.)

  The diamine is preferably represented by the following formula [2].

（式［２］中、ｐは０〜３の整数を表し、Ｒ_１０はアミノ基以外の一価の有機基を表し、−（Ｒ_１０）_ｐは置換基Ｒ_１０がｐ個あることを表しそれぞれ同一でも異なっていてもよい。ｑは０〜４の整数を表し、Ｒ_１１はアミノ基以外の一価の有機基を表し、−（Ｒ_１１）_ｑは置換基Ｒ_１１がｑ個あることを表しそれぞれ同一でも異なっていてもよい。ｎは１又は２であり、環を形成している飽和炭化水素部の水素原子はハロゲン原子又はアミノ基以外の有機基で置換されていてもよい。）

(In formula [2], p represents an integer of 0 to 3, R ₁₀ represents a monovalent organic group other than an amino group, and-(R ₁₀ ) _p represents _p substituents R _10. Each may be the same or different, q represents an integer of 0 to 4, R ₁₁ represents a monovalent organic group other than an amino group, and — (R ₁₁ ) _q has _q substituents R _11. And n may be the same or different, and n is 1 or 2, and the hydrogen atom of the saturated hydrocarbon portion forming the ring may be substituted with an organic group other than a halogen atom or an amino group. )

  Furthermore, the diamine is preferably represented by the following formula [3].

（式［３］中、ｎは１又は２であり、ｍは０〜２(ｎ＋１)の整数であり、Ｒ_１２はフッ素原子又はアミノ基以外の１価の有機基を表し、−（Ｒ_１２）_ｍは置換基Ｒ_１２がｍ個あることを表しそれぞれ同一でも異なっていてもよい。）

(In Formula [3], n is 1 or 2, m is an integer of 0 to 2 (n + 1), R ₁₂ represents a monovalent organic group other than a fluorine atom or an amino group, and — (R ₁₂ ) _m may be the same as or different from each other indicates that the substituent R ₁₂ is m-number.)

It is preferable that the _{R 12} is a hydrocarbon group having 1 to 6 carbon atoms, more _{preferably, R 12} is a methyl group.

  And it is preferable that it is n = 1.

  Moreover, the diamine represented by following formula [4-a]-[4-d] may be sufficient.

  The polyimide precursor of the present invention is obtained by reacting at least one selected from tetracarboxylic acids and derivatives thereof with a diamine component containing the diamine.

  In the polyimide precursor, the diamine is preferably 5 to 95 mol% when the total molar amount of the tetracarboxylic acid and its derivative is 100 mol%.

  In addition, the polyimide of the present invention is obtained by imidizing the polyimide precursor.

  And the liquid crystal aligning agent of this invention contains the said polyimide precursor and at least 1 type selected from the said polyimide, It is characterized by the above-mentioned.

  The liquid crystal alignment film of the present invention is obtained by applying the above liquid crystal aligning agent to a substrate and baking it.

  The liquid crystal display element of this invention comprises the said liquid crystal aligning film, It is characterized by the above-mentioned.

  ADVANTAGE OF THE INVENTION According to this invention, the novel diamine which can obtain the liquid crystal aligning agent with favorable printability, and can obtain the liquid crystal aligning film with few accumulation charges and quick relaxation of the accumulation | storage charge can be provided. . And it becomes a liquid crystal aligning agent with favorable printability by using this diamine. Also, by using this liquid crystal aligning agent, a liquid crystal alignment film with less accumulated charge and quick relaxation of the accumulated charge can be obtained. Therefore, the liquid crystal display element having the liquid crystal alignment film is less likely to cause a decrease in contrast or burn-in. The display characteristics are excellent.

Hereinafter, the present invention will be described in detail.
The diamine of the present invention is represented by the following formula [1].

（式［１］中、Ｒ_１〜Ｒ_９のうち二つは１級アミノ基、残りは水素原子またはアミノ基以外の一価の有機基であり、それぞれ同一でも異なっていてもよい。ｎは１又は２であり、環を形成している飽和炭化水素部の水素原子はハロゲン原子又はアミノ基以外の一価の有機基で置換されていてもよい。）

(In the formula [1], two of R _{1 to} R ₉ are primary amino groups, and the remainder are hydrogen atoms or monovalent organic groups other than amino groups, which may be the same or different. 1 or 2 and the hydrogen atom of the saturated hydrocarbon part forming the ring may be substituted with a monovalent organic group other than a halogen atom or an amino group.)

  In the formula [1], examples of the halogen atom include a fluorine atom. In the formula [1], the monovalent organic group other than the amino group includes a hydrocarbon group, a hydroxyl group, a carboxyl group, a hydroxyl group, a thiol group, or a hydrocarbon group containing a carboxyl group, an ether bond, and an ester bond. A hydrocarbon group linked by a linking group such as an amide bond, a hydrocarbon group containing a silicon atom, and a halogenated hydrocarbon group. In addition, examples of the monovalent organic group other than the amino group include an inactive group in which the amino group is protected by a carbamate-based protecting group such as a t-butoxycarbonyl group.

  Further, in the formula [1], the position of the amino group is not particularly limited, and is not particularly limited as long as it is a diamine, but is represented by the following formula [2] from the viewpoint of liquid crystal alignment and ease of synthesis. Position is preferred.

（式［２］中、ｐは０〜３の整数を表し、Ｒ_１０はアミノ基以外の一価の有機基を表し、−（Ｒ_１０）_ｐは置換基Ｒ_１０がｐ個あることを表しそれぞれ同一でも異なっていてもよい。ｑは０〜４の整数を表し、Ｒ_１１はアミノ基以外の一価の有機基を表し、−（Ｒ_１１）_ｑは置換基Ｒ_１１がｑ個あることを表しそれぞれ同一でも異なっていてもよい。ｎは１又は２であり、環を形成している飽和炭化水素部の水素原子はハロゲン原子又はアミノ基以外の有機基で置換されていてもよい。）

(In formula [2], p represents an integer of 0 to 3, R ₁₀ represents a monovalent organic group other than an amino group, and-(R ₁₀ ) _p represents _p substituents R _10. Each may be the same or different, q represents an integer of 0 to 4, R ₁₁ represents a monovalent organic group other than an amino group, and — (R ₁₁ ) _q has _q substituents R _11. And n may be the same or different, and n is 1 or 2, and the hydrogen atom of the saturated hydrocarbon portion forming the ring may be substituted with an organic group other than a halogen atom or an amino group. )

Further, as shown in the above formula [2], the hydrogen atom of the benzene ring having an amino group may be substituted with R ₁₀ or R ₁₁ which is a monovalent organic group other than the amino group. Various selections can be made depending on the sex. In the formula [2], the monovalent organic groups R ₁₀ and R ₁₁ other than the amino group include a hydrocarbon group, a carboxyl group, a hydroxyl group, a thiol group, or a hydrocarbon group having them, an ether bond, and an ester. Examples thereof include a hydrocarbon group linked by a bonding group such as a bond or an amide bond, a hydrocarbon group containing a silicon atom, or a halogenated hydrocarbon group. In addition, examples of R ₁₀ and R ₁₁ include an inert group in which an amino group is protected by a carbamate-based protecting group such as a t-butoxycarbonyl group. However, from the viewpoint of reagent availability and ease of synthesis, the hydrogen atom of the benzene ring having an amino group is preferably unsubstituted. A more specific structural example is shown in the following formula [3].

（式［３］中、ｎは１又は２であり、ｍは０〜２(ｎ＋１)の整数であり、Ｒ_１２はフッ素原子又はアミノ基以外の１価の有機基を表し、−（Ｒ_１２）_ｍは置換基Ｒ_１２がｍ個あることを表しそれぞれ同一でも異なっていてもよい。）

(In Formula [3], n is 1 or 2, m is an integer of 0 to 2 (n + 1), R ₁₂ represents a monovalent organic group other than a fluorine atom or an amino group, and — (R ₁₂ ) _m may be the same as or different from each other indicates that the substituent R ₁₂ is m-number.)

In the formulas [1] to [3], when n = 1, the diamine has an indoline structure, and when n = 2, the diamine has a tetrahydroquinoline structure. Each of them has a saturated hydrocarbon moiety that forms a ring, and the hydrogen atom of the carbon of the saturated hydrocarbon portion may be substituted with a halogen atom such as a fluorine atom or a monovalent organic group other than an amino group. . In the formula [3], the substituent that replaces the hydrogen atom of the saturated hydrocarbon portion is R ₁₂ . Examples of the monovalent organic group other than the amino group that replaces the hydrogen atom of the saturated hydrocarbon portion include a hydrocarbon group, a hydroxyl group, and a carboxyl group. The hydrocarbon group herein may be linear, branched or cyclic, and may be a saturated hydrocarbon or an unsaturated hydrocarbon, and some of the hydrogen atoms of the hydrocarbon group may be a carboxyl group, a hydroxyl group or a thiol group. Alternatively, it may be replaced by a silicon atom, a halogen atom, or the like, and may be linked by a bonding group such as an ether bond, an ester bond, or an amide bond. On the other hand, from the viewpoint of ease of synthesis and availability of reagents, R ₁₂ is preferably a hydrocarbon group composed of only carbon atoms and hydrogen atoms.

  It is preferable that the substituent which substitutes the hydrogen atom of carbon of a saturated hydrocarbon part is a C1-C6 hydrocarbon group. Polyimide precursors such as polyamic acid using the diamine of the present invention and polyimide have high solubility in a solvent, so the printability is good, but the hydrogen atom of the saturated hydrocarbon portion is a hydrocarbon group having 1 to 6 carbon atoms. This is because the solubility of the polyimide precursor such as polyamic acid and the polyimide in the organic solvent is further improved and the printability is further improved. In addition, since the solubility of the polyimide precursor such as polyamic acid and the polyimide in the solvent is high, the compatibility with other polymers is excellent, and the polyimide precursor and polyimide and other polymers using the diamine of the present invention. Even in the case of using a mixture, separation and precipitation are less likely to occur, and the printability is excellent. Specific examples of the hydrocarbon group having 1 to 6 carbon atoms include methyl group, ethyl group, propyl group, butyl group, t-butyl group, hexyl group, cyclopentyl group, cyclohexyl group, vinyl group, allyl group, 1 -A propenyl group, a 2-propenyl group, an isopropenyl group, a 1-methyl-2-propenyl group, a 1 or 2 or 3-butenyl group, a hexenyl group, a phenyl group and the like can be mentioned, but the invention is not limited thereto.

  When the hydrogen atom of the saturated hydrocarbon moiety is substituted with these substituents, the substitution position and number are not particularly limited, and various selections can be made depending on the ease of synthesis and the availability of reagents. A particularly preferred structure is one in which a hydrogen atom in the saturated hydrocarbon portion is substituted with a methyl group. From the viewpoint of ease of synthesis, those in which the hydrogen atom of the saturated hydrocarbon portion is not substituted are preferred. Although the specific example of the diamine of this invention preferable below is shown, it is not limited to this.

  Particularly preferred diamines of the present invention are:

  Polyimide precursors and polyimides such as polyamic acid and polyamic acid ester made from the diamine of the present invention represented by the above formula [1] as a raw material have good solubility in organic solvents, and thus form a liquid crystal alignment film. In this case, it is possible to obtain a liquid crystal aligning agent having good printability without forming pinholes or unevenness in the film thickness of the edge portion or the like. Further, when this liquid crystal aligning agent is used, it is possible to obtain a liquid crystal alignment film in which charge accumulation is unlikely to occur and the accumulated charge is quickly discharged. There is an effect that image sticking hardly occurs and display characteristics are excellent. In addition, an increase in ion density due to long-term use can be suppressed. Furthermore, the liquid crystal orientation is also good.

  This is because the diamine of the present invention has a diphenylamine structure having a site that acts as a steric hindrance and a saturated hydrocarbon moiety, so that it is possible to improve solubility and polymer compatibility while maintaining the electrical properties of diphenylamine. Thus, it is presumed that the above characteristics can be expressed. On the other hand, the diamine of Patent Document 3 has a structure that has a double bond at the position of the saturated hydrocarbon portion in the diamine of the present invention and does not have a saturated hydrocarbon portion. As shown in Comparative Examples described later, as in the case of using the diamine of the present invention, it is impossible to obtain a liquid crystal alignment film with a small amount of accumulated charges and a quick relaxation of accumulated charges, and the liquid crystal alignment properties are also poor. As a result, poor solubility and compatibility of polyimide with an organic solvent are obtained. This is presumably because the diamine of Patent Document 3 is rich in planarity and has a phenylindole skeleton that takes an electronic state different from that of diphenylamine.

  The main synthesis method of such a diamine of the present invention will be described. The method described below is a synthesis example and is not limited thereto.

  The diamine of the present invention can be obtained by reducing a dinitro compound and converting a nitro group to an amino group as shown in the following reaction formula. In the following reaction formula, a diamine in which the hydrogen atom of the benzene ring and the saturated hydrocarbon portion is not substituted with a halogen atom such as a fluorine atom or a monovalent organic group other than an amino group is described as an example.

  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. Examples of the method include reduction with hydrogen gas, hydrazine, hydrogen chloride and the like in a solvent. You may carry out under pressure using an autoclave etc. as needed. On the other hand, if the structure of the substituent that replaces the hydrogen atom in the benzene ring or saturated hydrocarbon part contains an unsaturated bond site, the use of palladium carbon, platinum carbon, etc. will reduce the unsaturated bond site and cause saturation. Since there exists a possibility that it may become a coupling | bonding, the reduction conditions using transition metals, such as reduced iron, tin, and tin chloride, as a catalyst are preferable.

  In the synthesis of a dinitro compound, as shown in the following reaction formula, a commercially available nitroindoline derivative or nitrotetrahydroquinoline derivative is reacted with nitrobenzene substituted with a leaving group X such as a halogen to thereby convert the dinitro compound. Can be obtained. Preferred leaving groups X include fluorine atom, chlorine atom, bromine atom, iodine atom, tosylate (-OTs), mesylate (-OMs) and the like.

  The above reaction can be carried out in the presence of a base. The base to be used is not particularly limited as long as it can be synthesized, but inorganic bases such as potassium carbonate, sodium carbonate, cesium carbonate, sodium alkoxide, potassium alkoxide, sodium hydroxide, potassium hydroxide, sodium hydride, pyridine, dimethylaminopyridine , Organic bases such as trimethylamine, triethylamine, and tributylamine. In some cases, when a palladium catalyst such as dibenzylideneacetone palladium or diphenylphosphinoferrocene palladium or a copper catalyst is used in combination, the yield can be improved. From the viewpoint of ease of synthesis, as shown in the following reaction formula, hydrogen of —NH— present in a nitroindoline derivative or nitrotetrahydroquinoline derivative is extracted using a base such as sodium hydride, and 4-nitro Although a method of reacting fluorobenzene is preferred, synthesis is not particularly limited because synthesis is possible by methods other than this method.

  By reacting the diamine of the present invention with at least one selected from a tetracarboxylic acid and a tetracarboxylic acid derivative, a polyimide precursor such as the polyamic acid or polyamic acid ester of the present invention can be obtained. In order to obtain this polyimide precursor, the ratio of reacting the diamine of the present invention with tetracarboxylic acid and its derivative is not particularly limited. For example, the total molar amount of tetracarboxylic acid and its derivative is 100 mol%. When it does, it is preferable that the diamine of this invention is 5-95 mol%.

  Examples of the tetracarboxylic acid derivative include tetracarboxylic acid dihalide, tetracarboxylic dianhydride, tetracarboxylic acid diester dichloride, and tetracarboxylic acid diester. For example, a polyamic acid can be obtained by reacting a tetracarboxylic acid or a derivative thereof such as tetracarboxylic acid dihalide or tetracarboxylic dianhydride with a diamine component containing the diamine of the present invention. Also, the reaction of tetracarboxylic acid diester dichloride with the diamine component containing the diamine of the present invention, the tetracarboxylic acid diester and the diamine component containing the diamine of the present invention in the presence of a suitable condensing agent, base, etc. By reacting, a polyamic acid ester can be obtained. In the present specification, the diamine component is a diamine that is reacted with at least one selected from tetracarboxylic acid and a tetracarboxylic acid derivative in order to obtain a polyimide precursor or a polyimide. The diamine of the present invention may be used in combination with other diamines.

  The polyimide precursor of the present invention is obtained by imidizing this polyimide precursor, specifically, dehydrating and ring-closing the polyamic acid, or heating the polyamic acid ester at a high temperature to promote dealcoholization and ring-closing. Can do.

  The polyimide precursor and polyimide such as polyamic acid and polyamic acid ester of the present invention will be described in further detail below. In the diamine component for obtaining a polyimide precursor such as polyamic acid by reaction with at least one selected from tetracarboxylic acid and tetracarboxylic acid derivatives such as tetracarboxylic dianhydride, the content of the diamine of the present invention There is no limit. The liquid crystal alignment film obtained by using the polyimide precursor of the present invention or a polyimide obtained by imidizing the same is a liquid crystal with less accumulated charge and faster relaxation of the accumulated charge as the diamine content ratio of the present invention increases. An alignment film can be obtained.

  For the purpose of speeding up the relaxation of the accumulated charge, it is preferable that 1 mol% or more of the diamine component is the diamine of the present invention. On the other hand, in consideration of other characteristics such as liquid crystal orientation and pretilt angle characteristics, the content of the diamine component of the present invention in the diamine component used for polymerization is preferably 20 to 90 mol%, particularly preferably 30 to 80 mol. %.

  In the said diamine component, other diamines other than the diamine represented by Formula [1] used when the diamine represented by Formula [1] is less than 100 mol% are not specifically limited. A specific example is as follows.

  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, 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 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.

  Examples of other diamines include diamine compounds having an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a heterocyclic ring, and a macrocyclic substituent composed of them in the side chain. Specifically, diamines represented by the following formulas [DA-1] to [DA-30] can be exemplified.

（式中、Ｒ_１３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表し、Ｓ_５は、−ＣＯＯ−、−ＯＣＯ−、−ＣＯＮＨ−、−ＮＨＣＯ−、−ＣＨ_２−、−Ｏ−、−ＣＯ−、又は−ＮＨ−を表す。）

(In the formula, R ₁₃ represents an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group, and S ₅ represents —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, — Represents O-, -CO-, or -NH-.)

（式中、Ｓ_６は、−Ｏ−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＣＯＯＣＨ_２−、又は−ＣＨ_２ＯＣＯ−を表し、Ｒ_１４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を表す。）

(In the formula, S ₆ represents —O—, —OCH ₂ —, —CH ₂ O—, —COOCH ₂ —, or —CH ₂ OCO—, and R ₁₄ represents an alkyl group having 1 to 22 carbon atoms, alkoxy Group, a fluorine-containing alkyl group or a fluorine-containing alkoxy group.)

（式中、Ｓ_７は、−ＣＯＯ−、−ＯＣＯ−、−ＣＯＮＨ−、−ＮＨＣＯ−、−ＣＯＯＣＨ_２−、−ＣＨ_２ＯＣＯ−、−ＣＨ_２Ｏ−、−ＯＣＨ_２−、又は−ＣＨ_２−を表し、Ｒ_１５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を表す。）

(In the formula, S ₇ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, —OCH ₂ —, or —CH _2. R ₁₅ represents an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group or a fluorine-containing alkoxy group.

（式中、Ｓ_８は、−ＣＯＯ−、−ＯＣＯ−、−ＣＯＮＨ−、−ＮＨＣＯ−、−ＣＯＯＣＨ_２−、−ＣＨ_２ＯＣＯ−、−ＣＨ_２Ｏ−、−ＯＣＨ_２−、−ＣＨ_２−、−Ｏ−、又は−ＮＨ−を表し、Ｒ_１６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、又は水酸基を表す。）

(In the formula, S ₈ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, —OCH ₂ —, —CH ₂ — , -O-, or -NH-, and R ₁₆ represents a fluorine group, a cyano group, a trifluoromethane group, a nitro group, an azo group, a formyl group, an acetyl group, an acetoxy group, or a hydroxyl group.

（式中、Ｒ_１７は炭素数３〜１２のアルキル基を表し、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 formula, R ₁₇ represents 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, a more stable pretilt can be obtained by using the diamine of the above formula [1] and the diamines of [DA-1] to [DA-30] in combination. The diamine used in combination is preferably a formula [DA-10] to [DA-30], more preferably a diamine of [DA-10] to [DA-16]. Although preferable content of these diamines is not particularly limited, 5 to 50 mol% is preferable with respect to the total amount of the diamine component, and 5 to 30 mol% is preferable from the viewpoint of printability.

  Other diamines include the following diamines.

（式中、ｉは０〜３の整数であり、ｊは１〜５の整数である。）

(In the formula, i is an integer of 0 to 3, and j is an integer of 1 to 5.)

  The voltage holding ratio (VHR) can be improved by introducing [DA-31] and [DA-32], and [DA-33] to [DA-38] can reduce the accumulated charge. it can.

  Moreover, diaminosiloxane etc. which are shown by the following formula [DA-39] can also be mentioned.

（式中、ｋは、１〜１０の整数である。）

(In the formula, k is an integer of 1 to 10.)

  Such other diamine compounds may be used alone or in combination of two or more depending on the liquid crystal alignment properties, voltage holding characteristics, accumulated charge, and the like when the liquid crystal alignment film is formed.

  Tetracarboxylic acid such as tetracarboxylic dianhydride and a derivative thereof to be reacted with a diamine component to obtain a polyimide precursor such as polyamic acid of the present invention are 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 [4.2.1.0 ^2,5 ] nonane-3,4,7,8-tetracarboxylic acid-3,4: 7,8-dianhydride, hexacyclo [6.6.0.1 ^{2 , 7} . 0 ^3,6 . 1 ^9,14 . 0 ^10,13] hexadecane -4,5,11,12- tetracarboxylic acid-4,5: 11,12-dianhydride, 4- (2,5-di-oxo-tetrahydrofuran-3-yl) -1,2 3,4-tetrahydronaphthalene-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 that is 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 [4.2.1.0 ^2,5 ] nonane-3,4,7,8-tetracarboxylic acid-3, 4: 7,8 A dialkyl ester, hexacyclo [6.6.0.1 ^2,7 . 0 ^3,6 . 1 ^9,14 . 0 ^10,13] hexadecane -4,5,11,12- tetracarboxylic acid-4,5: 11,12-dialkyl ester, 4- (2,5-di-oxo-tetrahydrofuran-3-yl) -1,2, Examples include 3,4-tetrahydronaphthalene-1,2-dicarboxylic dialkyl ester.

  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.

  In addition, polyamide can also be synthesize | combined by making diamine components, such as diamine of this invention, react with dicarboxylic acid. The dicarboxylic acid to be reacted with the diamine component in order to obtain polyamide is not particularly limited. Specific examples are given below.

  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 capable of giving a polyamide having a linear structure in order to maintain 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 preferred. 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 acid such as tetracarboxylic dianhydride and derivatives thereof may be used alone or in combination of two or more depending on properties such as liquid crystal alignment properties, voltage holding characteristics, and accumulated charges when formed into a liquid crystal alignment film. be able to.

  As a method of obtaining a polyimide precursor such as polyamic acid by reacting a diamine component with at least one selected from tetracarboxylic acid and tetracarboxylic acid derivatives, a known synthesis method can be used.

  For example, as a method of obtaining the polyamic acid of the present invention by reaction of tetracarboxylic dianhydride and a diamine component, a method of reacting tetracarboxylic dianhydride and diamine component in an organic solvent can be mentioned. 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 include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl Sulfone, hexamethylsulfoxide, 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, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, Dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate , Tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, 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, pyruvine Acid methyl, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, Xylpropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N, N-dimethylpropanamide, Examples include 3-ethoxy-N, N-dimethylpropanamide, 3-butoxy-N, N-dimethylpropanamide and the like. 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.

  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 to form a high molecular weight product.

  In this case, the polycondensation temperature can be selected from an arbitrary temperature of -20 ° C to 150 ° C, preferably in the range of -5 ° C to 100 ° C. Also, the polycondensation reaction can be carried out at any concentration, but if the concentration is too low, it will be difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution will become too high and uniform stirring will occur. 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 may be performed at a high concentration, and then an organic solvent may be added.

  In the polymerization reaction of polyamic acid, the ratio of the total number of moles of tetracarboxylic dianhydride and the total number of moles of diamine component (total number of moles of tetracarboxylic dianhydride / total number of moles of diamine component) is 0. .8 to 1.2 is preferable. 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 polyamic acid ester can be obtained by reacting the tetracarboxylic acid diester dichloride with the diamine component as described above, or reacting the tetracarboxylic acid diester with the diamine component in the presence of an appropriate condensing agent or base. it can. Alternatively, it can also be obtained by previously synthesizing a polyamic acid by the above method and esterifying the carboxylic acid in the amic acid using a polymer reaction.

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

  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.

  Further, when polycondensation of a tetracarboxylic acid diester and a diamine component in the presence of a condensing agent, as a base, 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- (benzotriazol-1-yl) -N, N, N ′, N′-tetramethyluronium hexafluorophosphate, (2,3-dihydro-2-thioxo-3-benzoxa Zolyl) phosphonic acid diphenyl, 4- (4,6-dimethoxy-1,3,5-triazin-2-yl And 4-methoxy mol ho potassium chloride n- hydrate can be used.

  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 of the diamine or tetracarboxylic acid diester to be reacted.

  The solvent used in the above reaction can be the same solvent as that used in the synthesis of the polyamic acid shown above. However, N-methyl-2-pyrrolidone, γ -Butyrolactone is preferable, and these may be used alone or in combination. The concentration at the time of synthesis is such that in the reaction solution of a tetracarboxylic acid derivative such as tetracarboxylic acid diester dichloride or tetracarboxylic acid diester and a diamine component, from the viewpoint that polymer precipitation is difficult to occur and a high molecular weight product is easily obtained. The total concentration is preferably 1 to 30% by mass, and more preferably 5 to 20% by mass. 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.

  The polyimide of the present invention can be obtained by dehydrating and ring-closing the polyamic acid. 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.

  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 is preferably performed while removing water generated by the imidation reaction from the system.

  The catalytic imidation of the polyamic acid can be performed by adding a basic catalyst and an acid anhydride to the 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 amidic 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.

  Further, as described above, the polyimide can also be obtained by heating the polyamic acid ester at a high temperature to promote dealcoholization and causing ring closure.

  In addition, when recovering the generated polyamic acid, polyamic acid ester, and polyimide from a polyimide precursor such as polyamic acid or polyamic acid ester, or a reaction solution of polyimide, the reaction solution is poured into a poor solvent and precipitated. That's fine. 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. After the polyimide precursor and polyimide which have been deposited in a poor solvent and precipitated are collected by filtration, they can be dried at room temperature or under normal pressure or reduced pressure. Moreover, the process of re-dissolving the precipitated and recovered polyimide precursor or polyimide in an organic solvent and repeating the reprecipitation and recovery can be repeated 2 to 10 times to reduce impurities in the polymer. 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 polyimide precursor and polyimide such as polyamic acid and polyamic acid ester to be contained in the liquid crystal aligning agent of the present invention takes into consideration the strength of the obtained coating film, workability at the time of coating film formation, and uniformity of the coating film. In this case, the weight average molecular weight measured by GPC (Gel Permeation Chromatography) method is preferably 5,000 to 1,000,000, and more preferably 10,000 to 150,000.

  The polyimide precursor and polyimide such as the polyamic acid and polyamic acid ester of the present invention can be used together with a solvent to form a liquid crystal aligning agent. A liquid crystal aligning agent is a solution for forming a liquid crystal aligning film, and is a solution in which a polymer component for forming a liquid crystal aligning film is dispersed or dissolved in an organic solvent. The liquid crystal alignment film is a film for aligning liquid crystals in a predetermined direction. In the present invention, the polymer component contains at least one selected from polyimide precursors such as the polyamic acid and polyamic acid ester of the present invention and polyimide.

  In the liquid crystal aligning agent of the present invention, all of the polymer components contained may be polyimide precursors or polyimides such as the polyamic acid or polyamic acid ester of the present invention, or the polyamic acid or polyamic of the present invention. Other polymers may be mixed with a polyimide precursor such as acid ester or polyimide. When another polymer is contained as the polymer component, the content of the other polymer in the total amount of the polymer component is 0.5% by mass to 50% by mass, preferably 1% by mass to 30% by mass. By using a mixture of plural kinds of polymers, the properties of the liquid crystal aligning agent and the liquid crystal aligning film can be improved.

  Examples of such other polymers include polyamic acid obtained by using a diamine other than the diamine represented by the above formula [1] of the present invention as a diamine component to be reacted with a tetracarboxylic dianhydride component. And polyamic acid ester and polyimide.

  In the liquid crystal aligning agent, at least one selected from polyimide precursors such as the polyamic acid and polyamic acid ester of the present invention and polyimide, and the content of other polymers mixed as necessary is the total amount of polymer components 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.

  The 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 polymer component is dissolved. Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethyl sulfoxide, tetra Methylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, 3-methoxy-N, N-dimethylpropanamide, 3-ethoxy-N, N-dimethylpropanamide, 3-butoxy-N, N-dimethylpropane Amide, 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, - such as hydroxy-4-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 solvents (poor solvents) that improve film thickness uniformity and surface smoothness include, for example, isopropyl alcohol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl Carbitol, ethyl carbitol, ethyl carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether , Dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol Cole 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 mono Propyl 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 acetate, methyl pyruvate, Ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, 3-methoxypropionic acid Butyl, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol 1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, lactate methyl ester, lactate ethyl ester, lactate n- Examples thereof include solvents having a low surface tension such as propyl ester, lactic acid n-butyl ester, and lactic acid isoamyl ester.

  These poor solvents may be used alone or in combination. When using the above solvent, it is preferable that it is 5-80 mass% of the whole solvent contained in a liquid crystal aligning agent, More preferably, it is 20-60 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 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltrimethoxysilane, and the like. Ethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltri Ethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 0-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3 , 6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3- Aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, Propylene glycol di Lysidyl 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-tetraglycidyl-2,4-hexanediol, N, N, N ′, N ′,-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidyl Examples thereof include functional silane-containing compounds such as aminomethyl) cyclohexane, N, N, N ′, N ′,-tetraglycidyl-4,4′-diaminodiphenylmethane, and epoxy group-containing compounds.

  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 the electrical characteristics due to the backlight. Specific phenoplast additives are shown below, but are not limited to this structure.

（式中、Ｍｅはメチル基を表す。）

(In the formula, Me represents a methyl group.)

  When using the compound which improves adhesiveness with a board | substrate, it is preferable that the usage-amount is 0.1-30 mass parts with respect to 100 mass parts of polymer components contained in a liquid crystal aligning agent, More preferably. Is 1-20 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.

  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. Since the liquid crystal alignment film of the present invention contains a polyimide precursor or polyimide formed using the diamine of the present invention, there is no pinhole formation or unevenness in the film thickness of the edge portion, etc. Accumulation of charges is difficult to occur, and the accumulated charges are quickly discharged.

  The substrate is not particularly limited as long as it has high transparency, and a glass substrate or a plastic substrate such as an acrylic substrate or a polycarbonate substrate can be used. In addition, it is preferable 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. In the reflective liquid crystal display element, an opaque material such as a silicon wafer can be used as long as it is only on one side of the substrate. In this case, a material that reflects light such as aluminum can be used as the electrode. As a high-performance element such as a TFT type element, an element in which an element such as a transistor is formed between an electrode for driving a liquid crystal and a substrate is 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 is performed at 50 to 300 ° C., preferably 80 to 250 ° C. by a heating means such as a hot plate, a hot-air circulating furnace, or an infrared furnace, and the solvent is evaporated to form a coating film. Can be formed. 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. Preferably it is 10-100 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. For example, the two substrates disposed so as to face each other, the liquid crystal layer provided between the substrates, and the liquid crystal aligning agent of the present invention provided between the substrate and the liquid crystal layer. A liquid crystal display device comprising a liquid crystal cell having a liquid crystal alignment film.

  The substrate used in the liquid crystal display element of the present invention is not particularly limited as long as it is a highly transparent substrate, but is usually a substrate on which a transparent electrode for driving liquid crystal is formed. As a specific example, the thing similar to the board | substrate described with the said liquid crystal aligning film can be mentioned.

  Further, the liquid crystal alignment film is formed by applying the liquid crystal aligning agent of the present invention on this substrate and baking it, and the details are as described above.

  The liquid crystal material constituting the liquid crystal layer of the liquid crystal display element of the present invention is not particularly limited, and liquid crystal materials used in the conventional vertical alignment method, such as MLC-2003, MLC-6608, MLC-6609 manufactured by Merck Ltd. Can be used.

  For example, a pair of substrates on which a liquid crystal alignment film is formed is prepared, spacers such as beads are dispersed on the liquid crystal alignment film of one substrate, and the liquid crystal alignment film surface is on the inside. In this way, the other substrate is bonded and the liquid crystal is injected under reduced pressure to seal, or the liquid crystal is dropped on the liquid crystal alignment film surface on which the spacers are dispersed and then the substrate is bonded and sealed. Can be illustrated. 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.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to the examples.
[Synthesis of diamine]
Abbreviations used below are as follows.
DMF: N, N-dimethylformamide THF: tetrahydrofuran RT: room temperature (25 ° C.)

  Synthesis Example 1 Synthesis of 1- (4-aminophenyl) -5-aminoindoline [Diamine-1] represented by the following formula

  (First Step) Synthesis of 1- (4-nitrophenyl) -5-nitroindoline

  To a 500 mL two-necked flask, 9.30 g (213 mmol) of sodium hydride (purity 55%) and 100 mL of dehydrated DMF were added and stirred under a nitrogen atmosphere while a DMF solution of 5-nitroindoline (5-nitroindoline: 35.0 g ( 213 mmol), DMF: 100 mL) was added dropwise so as not to exceed 30 ° C. After completion of dropping, the mixture was stirred at room temperature for 2 hours. To this reaction solution, a DMF solution of 4-fluoronitrobenzene (4-fluoronitrobenzene: 33.0 g (234.5 mmol), DMF: 100 mL) was added dropwise and stirred at room temperature for 6 hours under a nitrogen atmosphere.

  After completion of the reaction, 100 mL of pure water was slowly poured while stirring the reaction solution to precipitate a solid, the precipitated solid was filtered, dissolved again in DMF, poured again into 500 mL of pure water, re-precipitated, and the solid was again filtered and collected. . The obtained solid was dispersed and washed with methanol and n-hexane and vacuum dried to obtain 54.7 g (yield 90%) of an orange solid.

  (Second step) Synthesis of Diamine-1

  In a 300 mL four-necked flask, 15.0 g (52.6 mmol) of 1- (4-nitrophenyl) -5-nitroindoline obtained in the first step and 1.50 g of 10 mass% palladium carbon were measured, and 150 mL of ethanol was measured. In addition, after sufficiently purging with nitrogen, a hydrogen gas atmosphere was obtained, and the mixture was vigorously stirred at room temperature.

After completion of the reaction, palladium carbon was filtered using a glass filter, and the solvent was removed from the filtrate using a rotary evaporator. The obtained residue is dissolved in acetone, activated carbon is added and stirred for a while, the activated carbon is filtered, acetone is removed with a rotary evaporator, and then the mixture is re-mixed with a mixed solution of n-hexane and ethyl acetate (2: 3 mass ratio). Crystallization was performed to obtain 10.5 g (yield: 89%) of a light purple solid which is the target diamine (Diamine-1). 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: 6.87-6.23 (Aromatic-H, 7H), 4.77-4.68 (s-br, 2H), 4.39- 4.38 (s-br, 2H), 3,62-3, 58 (t, 2H), 2.89-2.87 (t, 2H)

  (Synthesis Example 2) Synthesis of 1- (4-aminophenyl) -2-methyl-5-aminoindoline [Diamine-2] represented by the following formula (racemic mixture)

  (First Step) Synthesis of 1- (4-nitrophenyl) -2-methyl-5-nitroindoline

  To a 500 mL two-necked flask, 2.45 g (56.1 mmol) of sodium hydride (purity 55%) and 100 mL of dehydrated DMF were added, and a DMF solution of 2-methyl-5-nitroindoline (2-methyl-) was stirred under a nitrogen atmosphere. 5-Nitroindoline: 10.0 g (56.1 mmol), DMF: 50 mL) was added dropwise so as not to exceed 30 ° C. After completion of dropping, the mixture was stirred at room temperature for 2 hours. To this reaction solution, a DMF solution of 4-fluoronitrobenzene (4-fluoronitrobenzene: 8.7 g (61.7 mmol), DMF: 50 mL) was added dropwise and stirred at room temperature for 6 hours under a nitrogen atmosphere.

  After completion of the reaction, 100 mL of pure water was slowly poured while stirring the reaction solution to precipitate a solid, the precipitated solid was filtered, dissolved again in DMF, poured again into 500 mL of pure water, re-precipitated, and the solid was again filtered and collected. . The obtained solid was dispersed and washed with methanol and n-hexane and vacuum dried to obtain 14.4 g (yield: 86%) of an orange solid.

  (Second step) Synthesis of Diamine-2

  In a 300 mL four-necked flask, 10.0 g (56.1 mmol) of 1- (4-nitrophenyl) -2-methyl-5-nitroindoline obtained in the first step and 1.00 g of 10% by mass palladium carbon were measured. After adding 150 mL of ethanol and sufficiently substituting with nitrogen, a hydrogen gas atmosphere was obtained and vigorously stirred at room temperature.

After completion of the reaction, palladium carbon was filtered using a glass filter, and the solvent was removed from the filtrate using a rotary evaporator. The obtained residue is dissolved in acetone, activated carbon is added and stirred for a while, the activated carbon is filtered, acetone is removed with a rotary evaporator, and then the mixture is re-mixed with a mixed solution of n-hexane and ethyl acetate (2: 3 mass ratio). Crystallization was performed to obtain 7.03 g (yield: 89%) of a light pink solid which is the target diamine (Diamine-2). The structure was confirmed by ¹ H-NMR spectrum. The measurement data is shown below.
¹ H NMR (400 MHz, [D ₆ ] -DMSO) δ: 6.86-6.84 (d, 2H), 6.56-6.22 (Aromatic-H, 7H), 4.77-4. 68 (s-br, 2H), 4.39-4.38 (s-br, 2H), 4.83-4.81 (m, 1H), 3,42-3, 38 (dd, 1H), 2.89-2.87 (dd, 1H) 1.48-1.47 (s, 3H)

  (Synthesis Example 3) Synthesis of 1- (4-aminophenyl) -2,3,3-trimethyl-5-aminoindoline [Diamine-3] (racemic mixture)

  (First Step) Synthesis of 1- (4-nitrophenyl) -2,3,3-trimethyl-5-nitroindoline

  To a 500 mL two-necked flask, 2.16 g (48.5 mmol) of sodium hydride (purity 55%) and 100 mL of dehydrated DMF are added, and a DMF solution of 2,3,3-trimethyl-5-nitroindoline with stirring in a nitrogen atmosphere. (2,3,3-trimethyl-5-nitroindoline: 10.0 g (48.5 mmol), DMF: 50 mL) was added dropwise so as not to exceed 30 ° C. After completion of dropping, the mixture was stirred at room temperature for 2 hours. To this reaction solution, a DMF solution of 4-fluoronitrobenzene (4-fluoronitrobenzene: 7.52 g (53.3 mmol), DMF: 50 mL) was added dropwise and stirred at room temperature for 6 hours under a nitrogen atmosphere.

  After completion of the reaction, 100 mL of pure water was slowly poured while stirring the reaction solution to precipitate a solid, the precipitated solid was filtered, dissolved again in DMF, poured again into 500 mL of pure water, re-precipitated, and the solid was again filtered and collected. . The obtained solid was dispersed and washed with methanol and n-hexane and vacuum dried to obtain 13.5 g (yield: 85%) of an orange solid.

  (Second step) Synthesis of Diamine-3

  In a 300 mL four-necked flask, 10.0 g (30.5 mmol) of 1- (4-nitrophenyl) -2,3,3-dimethyl-5-nitroindoline obtained in the first step and 10% by mass of palladium carbon 00 g was weighed, 150 mL of ethanol was added, and the atmosphere was sufficiently purged with nitrogen. Then, a hydrogen gas atmosphere was obtained, and the mixture was vigorously stirred at room temperature.

After completion of the reaction, palladium carbon was filtered using a glass filter, and the solvent was removed from the filtrate using a rotary evaporator. The obtained residue is dissolved in acetone, activated carbon is added and stirred for a while, the activated carbon is filtered, acetone is removed with a rotary evaporator, and then the mixture is re-mixed with a mixed solution of n-hexane and ethyl acetate (2: 3 mass ratio). Crystallization was performed to obtain 7.50 g (yield: 92%) of a light purple solid which is the target diamine (Diamine-3). The structure was confirmed by ¹ H-NMR spectrum. The measurement data is shown below.
¹ H NMR (400 MHz, [D ₆ ] -DMSO) δ: 6.86-6.22 (Aromatic-H, 7H), 4.74-4.66 (s-br, 2H), 4.41- 4.39 (s-br, 2H), 4.23-4.21 (m, 1H), 1.48-1.14 (s, 9H)

  Synthesis Example 4 Synthesis of 1- (4-aminophenyl) -6-amino-1,2,3,4-tetrahydroquinoline [Diamine-4] represented by the following formula

  (First Step) Synthesis of 6- (tert-butoxycarbonyl) aminoquinoline

  In a 200 mL four-necked flask, 5.00 g (34.7 mmol) of 6-aminoquinoline was dissolved in 100 mL of THF, 7.57 g (34.7 mmol) of tertbutyl dicarbonate was added, and the mixture was refluxed for 20 hours under a nitrogen atmosphere.

  After completion of the reaction, THF was removed by a rotary evaporator, ethyl acetate was added, washed with pure water and saturated brine, and dried over anhydrous magnesium sulfate. After removing anhydrous magnesium sulfate by filtration, the solvent was removed with a rotary evaporator, and the residue was recrystallized with a mixed solvent of ethyl acetate and n-hexane (1: 4 volume ratio) to obtain a white solid. 29 g (86%) were obtained.

  (Second Step) Synthesis of 6- (tert-butoxycarbonyl) amino-1,2,3,4-tetrahydroquinoline

  In a 100 mL two-necked flask, weigh 5.00 g (20.4 mmol) of 6- (tert-butoxycarbonyl) aminoquinoline obtained in the first step and 0.50 g of 10% by mass palladium carbon, add 50 mL of methanol, After the replacement, a hydrogen gas atmosphere was used, and the mixture was vigorously stirred at 60 ° C.

  After completion of the reaction, palladium carbon was filtered using a glass filter, and the solvent was removed from the filtrate using a rotary evaporator. The obtained residue is dissolved in acetone, activated carbon is added and stirred for a while, the activated carbon is filtered, acetone is removed with a rotary evaporator, and then the mixture is re-mixed with a mixed solution of n-hexane and ethyl acetate (2: 3 mass ratio). Crystallization was performed to obtain 3.65 g (yield: 72%) of a white glassy solid.

  (Third step) Synthesis of 1- (4-nitrophenyl) -6-amino-1,2,3,4-tetrahydroquinoline

  To a 100 mL two-necked flask, 0.615 g (14.1 mmol) of sodium hydride (purity 55%) and 20 mL of dehydrated DMF were added, and 6- (tert-butoxycarbonyl) obtained in the second step while stirring under a nitrogen atmosphere. DMF solution of amino-1,2,3,4-tetrahydroquinoline (6- (tert-butoxycarbonyl) amino-1,2,3,4-tetrahydroquinoline: 3.50 g (14.1 mmol), DMF: 20 mL) Was added dropwise so as not to exceed 30 ° C. After completion of the dropwise addition, the mixture was stirred for 2 hours. To this reaction solution, a DMF solution of 4-fluoronitrobenzene (4-fluoronitrobenzene: 2.19 g (15.5 mmol), DMF: 20 mL) was added dropwise and stirred at room temperature for 20 hours under a nitrogen atmosphere.

  After completion of the reaction, 30 mL of pure water was slowly poured while stirring the reaction solution to precipitate a solid, the precipitated solid was filtered, dissolved again in DMF, poured into 100 mL of pure water and reprecipitated, and the solid was filtered and collected again. . A yellow solid was obtained by dispersing and washing with n-hexane and vacuum drying. To this solid was added 4N hydrochloric acid-ethyl acetate solution, and the mixture was stirred at 40 ° C. for 2 hours. Pure water was added to the reaction solution, and the aqueous layer was collected, neutralized with sodium bicarbonate, extracted with ethyl acetate, washed with water and saturated brine, and dried over anhydrous magnesium sulfate. After removing anhydrous magnesium sulfate by filtration, the solvent was removed by a rotary evaporator, and the residue was subjected to column chromatography (mixed solvent of ethyl acetate and dichloroethane in a 1: 1 volume ratio) to obtain 2.20 g of a yellow solid. (Yield: 58%) was obtained.

  (Fourth Step) Synthesis of 1- (4-aminophenyl) -6-amino-1,2,3,4-tetrahydroquinoline [Diamine-4]

  In a 500 mL four-necked flask, 1- (4-nitrophenyl) -6-amino-1,2,3,4-tetrahydroquinoline obtained in the third step was 10.0 (37.1 mmol), 10% by mass palladium carbon. 1.00 g was weighed out, 300 mL of ethanol was added, and the atmosphere was sufficiently purged with nitrogen. Then, the atmosphere was hydrogen gas and vigorously stirred at room temperature.

After completion of the reaction, palladium carbon was filtered using a glass filter, and the solvent was removed from the filtrate using a rotary evaporator. The obtained residue is dissolved in acetone, activated carbon is added and stirred for a while, the activated carbon is filtered, acetone is removed with a rotary evaporator, and then the mixture is re-mixed with a mixed solution of n-hexane and ethyl acetate (5: 1 mass ratio). Crystallization was performed to obtain 7.30 g (yield: 82%) of a light purple solid which is the target diamine (Diamine-4). The structure was confirmed by ¹ H-NMR spectrum. The measurement data is shown below.
¹ H NMR (400 MHz, [D ₆ ] -DMSO) δ: 6.85-6.35 (Aromatic-H, 7H), 5.00-4.98 (s-br, 2H), 4.59- 4.58 (s-br, 2H), 3,94-3, 93 (m, 2H), 2.89-2.87 (m, 2H), 2.66-2.64 (m, 2H)

  (Synthesis Comparative Example 1) Synthesis of 1- (4-aminophenyl) -5-aminoindole [Diamine-5]

  (First Step) Synthesis of 1- (4-nitrophenyl) -5-nitroindole

  To a 500 mL two-necked flask, 4.48 g (101.8 mmol) of sodium hydride (purity 55%) and 50 mL of dehydrated DMF were added, and a DMF solution of 5-nitroindole (5-nitroindole: 15. 0 g (92.5 mmol), DMF: 100 mL) was added dropwise so as not to exceed 30 ° C. After completion of dropping, the mixture was stirred at room temperature for 2 hours. To this reaction solution, a DMF solution of 4-fluoronitrobenzene (4-fluoronitrobenzene: 13.1 g (92.5 mmol), DMF: 100 mL) was added dropwise and stirred at room temperature for 6 hours under a nitrogen atmosphere.

  After completion of the reaction, 100 mL of pure water was slowly poured while stirring the reaction solution to precipitate a solid, the precipitated solid was filtered, dissolved again in DMF, poured again into 500 mL of pure water, re-precipitated, and the solid was again filtered and collected. . The obtained solid was dispersed and washed with methanol and n-hexane and vacuum dried to obtain 25.0 g (yield 95%) of a yellow solid.

  (Second Step) Synthesis of 1- (4-aminophenyl) -5-aminoindole [Diamine-5]

  In a 500 mL four-necked flask, weigh 20.0 g (70.6 mmol) of 1- (4-nitrophenyl) -5-nitroindole obtained in the first step and 2.00 g of 10% by mass palladium carbon, and add 300 mL of ethanol. In addition, after sufficiently purging with nitrogen, the atmosphere was changed to a hydrogen gas atmosphere and refluxed for 42 hours.

After completion of the reaction, palladium carbon was filtered using a glass filter, and the solvent was removed from the filtrate using a rotary evaporator. The obtained residue was dissolved in acetone, activated carbon was added and stirred for a while, the activated carbon was filtered, acetone was removed with a rotary evaporator, and the residue was washed with n-hexane to obtain the target diamine (Diamine-5. 15.0 g (yield: 95%) of a light pink solid was obtained. The structure was confirmed by ¹ H-NMR spectrum. The measurement data is shown below.
¹ H NMR (400 MHz, [D ₆ ] -DMSO) δ: 7.25-6.28 (Aromatic-H, 9H), 5.20 (s-br, 2H), 4.56 (s-br, 2H)

[Synthesis of polyamic acid and polyimide and preparation of liquid crystal aligning agent]
The abbreviations of the compounds used below are as follows. In addition, Table 1 and Table 2 show the raw materials of the polymers synthesized in the respective Examples and Comparative Examples and the composition of the liquid crystal aligning agent.

<Tetracarboxylic dianhydride>
CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride TDA: 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride CBDE: 1,2, 3,4-Cyclobutanetetracarboxylic acid dimethyl ester

<Diamine>
p-PDA: 1,4-phenylenediamine DDM: 4,4-diaminodiphenylmethane C16DAB: 4-hexadecyloxy-1,3-diaminobenzene

<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 γ-BL: γ-butyrolactone BC: butyl cellosolve DPM: dipropylene glycol monomethyl ether

<Measurement of molecular weight>
The molecular weight of the polymer 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 · H ₂ O) 30 mmol / L, phosphoric acid / anhydrous crystal (o-phosphoric acid) 30 mmol / L, tetrahydrofuran) (THF) is 10 mL / L)
Flow rate: 1.0 mL / 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. Add 20 mg of polyimide powder to an NMR sample tube (NMR sampling tube standard manufactured by Kusano Kagaku), add 0.53 mL of deuterated dimethyl sulfoxide (DMSO-d6, 0.05% TMS mixture), and apply ultrasonic waves. It was completely dissolved. 500 MHz proton NMR was measured for this solution with the NMR measuring device (JNW-ECA500) by JEOL datum. The imidation rate is determined based on protons derived from structures that do not change before and after imidation as reference protons, and the peak integrated value of these protons and proton peaks derived from NH groups of amic acid appearing in the vicinity of 9.5 to 10.0 ppm. It calculated | required by the following formula | equation using the integrated value. 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 the NH group proton of the amic acid in the case of polyamic acid (imidation rate is 0%). This is the ratio of the number of reference protons to one.
Imidation ratio (%) = (1−α · x / y) × 100

(Example 1) Synthesis of polyamic acid using CBDA / Diamine-1 As a diamine component in a 50 mL four-necked flask, 1.50 g (6.65 mmol) of Diamin-1 obtained in Synthesis Example 1 and 15 NMP were obtained. .3 g, cooled to about 10 ° C., added 1.22 g (6.20 mmol) of CBDA, returned to room temperature, allowed to react for 6 hours under a nitrogen atmosphere, and a polyamic acid (PAA-1) solution having a concentration of 15% by mass was obtained. Obtained.

  15.0 g of this polyamic acid (PAA-1) solution was transferred to a 50 mL Erlenmeyer flask, diluted by adding 15.0 g of NMP and 7.50 g of BC, and 6% by mass of polyamic acid (PAA-1) and NMP The liquid crystal aligning agent-1 of this invention was obtained by making it into a 74 mass% and BC 20 mass% solution. The number average molecular weight of this polyamic acid was 12,300, and the weight average molecular weight was 33,100.

(Example 2) Synthesis of polyamic acid using CBDA / Diamine-2 As a diamine component in a 50 mL four-necked flask, 1.50 g (6.25 mmol) of Diamin-2 obtained in Synthesis Example 2 and 15 of NMP were obtained. Add 1.0 g, cool to about 10 ° C., add 1.14 g (5.80 mmol) of CBDA, return to room temperature, react for 6 hours in a nitrogen atmosphere, and add a polyamic acid (PAA-2) solution with a concentration of 15% by mass. Obtained.

  15.0 g of this polyamic acid (PAA-2) solution was transferred to a 50 mL Erlenmeyer flask, diluted by adding 15.0 g of NMP and 7.50 g of BC, and 6% by mass of polyamic acid (PAA-2) and NMP A liquid crystal aligning agent-2 of the present invention was obtained by using a 74% by mass and 20% by mass BC solution. The number average molecular weight of this polyamic acid was 13,700, and the weight average molecular weight was 35,600.

(Example 3) Synthesis of polyamic acid using CBDA / Diamine-3 As a diamine component in a 50 mL four-necked flask, 1.50 g (5.80 mmol) of Diamin-3 obtained in Synthesis Example 3 and 14 of NMP were obtained. .3 g, cooled to about 10 ° C., added 1.02 g (5.20 mmol) of CBDA, returned to room temperature, allowed to react for 6 hours under a nitrogen atmosphere, and a polyamic acid (PAA-3) solution having a concentration of 15% by mass was obtained. Obtained.

  15.0 g of this polyamic acid (PAA-3) solution was transferred to a 50 mL Erlenmeyer flask, diluted by adding 15.0 g of NMP and 7.50 g of BC, and 6% by mass of polyamic acid (PAA-3) and NMP The liquid crystal aligning agent-3 of this invention was obtained by making it into a 74 mass% and BC 20 mass% solution. The number average molecular weight of this polyamic acid was 11,000, and the weight average molecular weight was 31,300.

(Example 4) Synthesis of polyamic acid using CBDA / Diamine-4 As a diamine component in a 50 mL four-necked flask, 1.50 g (6.25 mmol) of Diamine-4 obtained in Synthesis Example 4 and 15 of NMP were obtained. Add 1.0 g, cool to about 10 ° C., add 1.14 g (5.80 mmol) of CBDA, return to room temperature, react for 6 hours in a nitrogen atmosphere, and add a polyamic acid (PAA-4) solution with a concentration of 15% by mass. Obtained.

  15.0 g of this polyamic acid (PAA-4) solution was transferred to a 50 mL Erlenmeyer flask, diluted by adding 15.0 g of NMP and 7.50 g of BC, and 6% by mass of polyamic acid (PAA-4) and NMP The liquid crystal aligning agent-4 of this invention was obtained by making it into a 74 mass% and BC 20 mass% solution. The number average molecular weight of this polyamic acid was 14,200, and the weight average molecular weight was 36,700.

(Comparative Example 1) Synthesis of polyamic acid using CBDA / Diamine-5 As a diamine component in a 50 mL four-necked flask, 1.50 g (6.75 mmol) of Diamin-5 obtained in Synthesis Comparative Example 1 and 15 NMP were obtained. .4 g was added, cooled to about 10 ° C., 1.23 g (6.25 mmol) of CBDA was added, and the mixture was returned to room temperature and reacted for 6 hours under a nitrogen atmosphere, and a polyamic acid (PAA-5) solution having a concentration of 15% by mass was obtained. Obtained.

  15.0 g of this polyamic acid (PAA-5) solution was transferred to a 50 mL Erlenmeyer flask, diluted by adding 15.0 g of NMP and 7.50 g of BC, and 6% by mass of polyamic acid (PAA-5) and NMP The liquid crystal aligning agent-5 used as a comparison object was obtained by using a 74% by mass and 20% by mass BC solution. The number average molecular weight of this polyamic acid was 12,300, and the weight average molecular weight was 32,100.

(Example 5) Synthesis of soluble polyimide using CBDA / Diamine-1 and C16DAB As a diamine component in a 50 mL four-neck flask, 2.00 g (8.88 mmol) of Diamine obtained in Synthesis Example 1 was obtained. 0.774 g (2.22 mmol) and 27.2 g of NMP were added, cooled to about 10 ° C., 1.81 g (10.3 mmol) of CBDA was added, returned to room temperature, reacted for 6 hours under a nitrogen atmosphere, and polyamic acid was added. A solution having a concentration of 15% by mass of (PAA-6) was obtained.

  To 20 g of the polyamic acid (PAA-6) solution, 30.0 g of NMP was added for dilution, 2.19 g of acetic anhydride and 0.90 g of pyridine were added, and the mixture was reacted at 40 ° C. for 3 hours. The reaction solution was cooled to about room temperature and then slowly poured into 180 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 100 mL of methanol, and dried under reduced pressure at 100 ° C. to obtain a light purple powder of polyimide (SPI-1). The number average molecular weight of this polyimide was 9,200, and the weight average molecular weight was 23,500. The imidation ratio was 81%.

  Γ-BL 18.0 g was added to 2.00 g of polyimide (SPI-1), and the mixture was stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Further, γ-BL 8.0 g and BC 12.0 g were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours. A liquid crystal containing 5% by mass of polyimide (SPI-1), 65% by mass of γ-BL, and 30% by mass of BC. An aligning agent-6 was obtained.

(Example 6) Synthesis of soluble polyimide using CBDA / Diamine-2 and C16DAB As a diamine component in a 50 mL four-necked flask, 2.00 g (8.36 mmol) of Diamine-2 obtained in Synthesis Example 2 and C16DAB 0.728 g (2.09 mmol) and 6.3 g of NMP were added, cooled to about 10 ° C., 1.90 g (9.71 mmol) of CBDA was added, returned to room temperature, reacted for 6 hours under a nitrogen atmosphere, and polyamic acid was added. A solution having a concentration of 15% by mass of (PAA-7) was obtained.

  To 20 g of the polyamic acid (PAA-7) solution, 30.0 g of NMP was added for dilution, and 2.12 g of acetic anhydride and 0.88 g of pyridine were added and reacted at 40 ° C. for 3 hours. The reaction solution was cooled to about room temperature and then slowly poured into 160 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 100 mL of methanol, and dried under reduced pressure at 100 ° C. to obtain a light purple powder of polyimide (SPI-2). The number average molecular weight of this polyimide was 9,800, and the weight average molecular weight was 24,200. The imidation ratio was 80%.

  12.0 g of γ-BL was added to 2.00 g of polyimide (SPI-2), and the mixture was stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Further, γ-BL 8.0 g and BC 12.0 g were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours. A liquid crystal containing 5% by mass of polyimide (SPI-2), 65% by mass of γ-BL, and 30% by mass of BC. An aligning agent-7 was obtained.

(Example 7) Synthesis of soluble polyimide using CBDA / Diamine-3, C16DAB As a diamine component in a 50 mL four-necked flask, 2.00 g (7.47 mmol) of Diamine-3 obtained in Synthesis Example 3 was obtained. 0.651 g (1.87 mmol) and 24.7 g of NMP were added, cooled to about 10 ° C., 1.51 g (8.68 mmol) of CBDA was added, and the mixture was returned to room temperature and allowed to react for 6 hours under a nitrogen atmosphere. A solution having a concentration of 15% by mass of (PAA-8) was obtained.

  To 20 g of the polyamic acid (PAA-8) solution, 30.0 g of NMP was added for dilution, and 2.00 g of acetic anhydride and 0.83 g of pyridine were added and reacted at 40 ° C. for 3 hours. The reaction solution was cooled to about room temperature and then slowly poured into 160 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 100 mL of methanol, and dried under reduced pressure at 100 ° C. to obtain a light purple powder of polyimide (SPI-3). The number average molecular weight of this polyimide was 9,500, and the weight average molecular weight was 22,200. The imidation ratio was 81%.

  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. Further, γ-BL 8.0 g and BC 12.0 g were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours. A liquid crystal containing 5% by mass of polyimide (SPI-3), 65% by mass of γ-BL, and 30% by mass of BC. An aligning agent-8 was obtained.

(Example 8) Synthesis of soluble polyimide using CBDA / Diamine-4, C16DAB As a diamine component in a 50 mL four-necked flask, 2.00 g (8.36 mmol) of Diamine-4 obtained in Synthesis Example 4 was obtained. 0.728 g (2.09 mmol) and 6.3 g of NMP were added, cooled to about 10 ° C., 1.90 g (9.71 mmol) of CBDA was added, returned to room temperature, reacted for 6 hours under a nitrogen atmosphere, and polyamic acid was added. A solution having a concentration of 15% by mass of (PAA-8) was obtained.

  To 20 g of the polyamic acid (PAA-8) solution, 30.0 g of NMP was added for dilution, and 2.12 g of acetic anhydride and 0.88 g of pyridine were added and reacted at 40 ° C. for 3 hours. The reaction solution was cooled to about room temperature and then slowly poured into 180 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 100 mL of methanol, and dried under reduced pressure at 100 ° C. to obtain a light purple powder of polyimide (SPI-4). The number average molecular weight of this polyimide was 10,200, and the weight average molecular weight was 28,900. The imidation ratio was 82%.

  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. Further, γ-BL 8.0 g and BC 12.0 g were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours. A liquid crystal containing 5% by mass of polyimide (SPI-4), 65% by mass of γ-BL, and 30% by mass of BC. An aligning agent-9 was obtained.

(Comparative Example 2) Synthesis of soluble polyimide using CBDA / Diamine-5 and C16DAB As a diamine component in a 50 mL four-necked flask, 2.00 g (8.96 mmol) of Diamine-5 obtained in Synthesis Comparative Example 1 was obtained. 0.781 g (2.24 mmol) and 27.3 g of NMP were added, cooled to about 10 ° C., 2.04 g (10.4 mmol) of CBDA was added, and the mixture was returned to room temperature and allowed to react for 6 hours under a nitrogen atmosphere. A solution having a concentration of 15% by mass of (PAA-9) was obtained.

  To 20 g of polyamic acid (PAA-9) solution, 30.0 g of NMP was added for dilution, and 2.20 g of acetic anhydride and 0.91 g of pyridine were added and reacted at 40 ° C. It became impossible. Soluble polyimide (SPI-5) could not be prepared. Therefore, the liquid crystal aligning agent-10 used as a comparison object was not able to be prepared.

Example 9
<Synthesis of polyamic acid using CBDA / Diamine-1, DDM>
As a diamine component in a 50 mL four-neck flask, Diamin-1 obtained in Synthesis Example 1 was 2.50 g (11.1 mmol), DDM was 0.943 g (4.77 mmol), NMP was 17.9 g, and γ-BL. 18.9 g, cooled to about 10 ° C., added 2.89 g (14.8 mmol) of CBDA, returned to room temperature, reacted for 6 hours in a nitrogen atmosphere, and a polyamic acid (PAA-10) solution having a concentration of 15% by mass Got.

  30.0 g of this polyamic acid (PAA-10) solution was transferred to a 100 mL Erlenmeyer flask, diluted with 28.0 g of NMP, 2.20 g of γ-BL, and 15.0 g of BC, and diluted with polyamic acid (PAA-10). ) Is 6% by mass, NMP is 54% by mass, γ-BL is 20% by mass, and BC is 20% by mass to obtain a polyamic acid solution for blending (BL-PAA1). The number average molecular weight of this polyamic acid was 10,400, and the weight average molecular weight was 29,100.

<Synthesis of soluble polyimide using TDA / p-PDA, C16DAB>
As a diamine component, add 2.00 g (18.5 mmol) of p-PDA, 0.718 g (2.06 mmol) of C16DAB, and 35.4 g of NMP to a 50 mL four-necked flask, and cool to about 10 ° C. 6.12 g (20.4 mmol) was added, and the mixture was reacted at 40 ° C. for 20 hours under a nitrogen atmosphere to obtain a 20% by mass solution of polyamic acid (PAA-15).

  To 40.0 g of a polyamic acid (PAA-15) solution, 93.3 g of NMP was added for dilution, and 9.51 g of acetic anhydride and 7.36 g of pyridine were added and reacted at 40 ° C. for 3 hours. The reaction solution was cooled to about room temperature and then 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 300 mL of methanol, and 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 9,500, and the weight average molecular weight was 20,900. Moreover, the imidation ratio was 85%.

  80.5 g of γ-BL was added to 7.00 g of polyimide (SPI-6), and the mixture was stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Further, 29.2 g of γ-BL was added to this solution, and the mixture was stirred at 50 ° C. for 20 hours to prepare a solution containing 6% by mass of polyimide (SPI-6) and 94% by mass of γ-BL, and a polyimide solution for blending (BL-SPI )

<Preparation of blend type liquid crystal aligning agent>
40 g of the prepared polyamic acid solution for blending (BL-PAA1) is weighed into a 200 mL Erlenmeyer flask, 10.0 g of the prepared polyimide solution for blending (BL-SPI) is added, and the mixture is stirred for 20 hours under a nitrogen atmosphere, and blended liquid crystal An alignment agent BL-1 was obtained.

(Example 10)
<Synthesis of polyamic acid using CBDA / Diamine-2, DDM>
As a diamine component in a 50 mL four-necked flask, 2.50 g (10.4 mmol) of Diamine-2 obtained in Synthesis Example 2, 0.887 g (4.47 mmol) of DDM, 17.3 g of NMP, γ-BL 17.3 g, cooled to about 10 ° C., added 2.72 g (13.9 mmol) of CBDA, returned to room temperature, reacted for 6 hours in a nitrogen atmosphere, and a polyamic acid (PAA-11) solution having a concentration of 15% by mass Got.

  30.0 g of this polyamic acid (PAA-11) solution was transferred to a 100 mL Erlenmeyer flask, diluted with 28.0 g of NMP, 2.20 g of γ-BL, and 15.0 g of BC, and diluted with polyamic acid (PAA-11). ) Is 6% by mass, NMP is 54% by mass, γ-BL is 20% by mass, and BC is 20% by mass to obtain a polyamic acid solution for blending (BL-PAA2). The number average molecular weight of this polyamic acid was 11,200, and the weight average molecular weight was 31,000.

<Preparation of blend type liquid crystal aligning agent>
40 g of the prepared polyamic acid solution for blending (BL-PAA2) was weighed into a 200 mL Erlenmeyer flask, 10.0 g of the polyimide solution for blending prepared in the same manner as in Example 9 (BL-SPI) was added, and under a nitrogen atmosphere For 20 hours to obtain a blend type liquid crystal aligning agent BL-2.

(Example 11)
<Synthesis of polyamic acid using CBDA / Diamine-3, DDM>
As a diamine component in a 50 mL four-necked flask, Diamin-3 obtained in Synthesis Example 3 was 2.50 g (9.35 mmol), DDM was 0.794 g (4.01 mmol), NMP was 16.2 g, and γ-BL. 16.2 g was added, cooled to about 10 ° C., 2.43 g (12.4 mmol) of CBDA was added, returned to room temperature, reacted for 6 hours in a nitrogen atmosphere, and a solution of polyamic acid (PAA-12) having a concentration of 15% by mass Got.

  30.0 g of this polyamic acid (PAA-12) solution was transferred to a 100 mL Erlenmeyer flask, diluted with 28.0 g of NMP, 2.20 g of γ-BL, and 15.0 g of BC, and diluted with polyamic acid (PAA-12). ) Is 6% by mass, NMP is 54% by mass, γ-BL is 20% by mass, BC is 20% by mass, and the polyamic acid solution for blending (BL-PAA3) was obtained. The weight average molecular weight was 13,600 and the weight average molecular weight was 36,000.

<Preparation of blend type liquid crystal aligning agent>
40 g of the prepared polyamic acid solution for blending (BL-PAA3) was weighed into a 200 mL Erlenmeyer flask, 10.0 g of the blending polyimide solution (BL-SPI) prepared in the same manner as in Example 9 was added, and under a nitrogen atmosphere For 20 hours to obtain a blend liquid crystal aligning agent BL-3.

(Example 12)
<Synthesis of polyamic acid using CBDA / Diamine-4, DDM>
As a diamine component in a 50 mL four-necked flask, 2.45 g (10.4 mmol) of Diamine-4 obtained in Synthesis Example 4, 0.887 g (4.47 mmol) of DDM, 17.3 g of NMP, γ-BL 17.3 g, cooled to about 10 ° C., added 2.72 g (13.9 mmol) of CBDA, returned to room temperature, reacted for 6 hours in a nitrogen atmosphere, and a polyamic acid (PAA-13) solution having a concentration of 15% by mass Got.

  30.0 g of this polyamic acid (PAA-13) solution was transferred to a 100 mL Erlenmeyer flask, diluted with 28.0 g of NMP, 2.20 g of γ-BL, and 15.0 g of BC, and diluted with polyamic acid (PAA-13). ) Is 6% by mass, NMP is 54% by mass, γ-BL is 20% by mass, and BC is 20% by mass to obtain a polyamic acid solution for blending (BL-PAA4). The number average molecular weight of this polyamic acid was 12,500, and the weight average molecular weight was 30,800.

<Preparation of blend type liquid crystal aligning agent>
40 g of the prepared polyamic acid solution for blending (BL-PAA4) was weighed in each 200 mL Erlenmeyer flask, 10.0 g of the polyimide solution for blending prepared in the same manner as in Example 9 (BL-SPI) was added, and under a nitrogen atmosphere For 20 hours to obtain a blend liquid crystal aligning agent BL-4.

(Comparative Example 3)
<Synthesis of polyamic acid using CBDA / Diamine-5, DDM>
As a diamine component in a 50 mL four-neck flask, Diamin-5 obtained in Synthesis Comparative Example 1 was 2.50 g (11.2 mmol), DDM was 0.952 g (4.80 mmol), NMP was 18.1 g, and γ-BL. 18.1 g of the mixture, cooled to about 10 ° C., added 2.92 g (14.9 mmol) of CBDA, returned to room temperature, reacted for 6 hours in a nitrogen atmosphere, and a polyamic acid (PAA-14) solution having a concentration of 15% by mass. Got.

  30.0 g of this polyamic acid (PAA-14) solution was transferred to a 100 mL Erlenmeyer flask, diluted with 28.0 g of NMP, 2.20 g of γ-BL, and 15.0 g of BC, and diluted with polyamic acid (PAA-14). ) Was 6 mass%, NMP was 54 mass%, γ-BL was 20 mass%, and BC was 20 mass% to obtain a polyamic acid solution for blending (BL-PAA5). The number average molecular weight of this polyamic acid was 13,600, and the weight average molecular weight was 37,700.

<Preparation of blend type liquid crystal aligning agent>
40 g of the prepared polyamic acid solution for blending (BL-PAA4) was weighed in each 200 mL Erlenmeyer flask, 10.0 g of the polyimide solution for blending prepared in the same manner as in Example 9 (BL-SPI) was added, and under a nitrogen atmosphere For 20 hours to obtain a blend type liquid crystal aligning agent BL-5.

(Example 13)
<PAE for blending>
In a 100 mL four-necked flask, 6.35 g (24.4 mmol) of CBDE, 250 g (23.1 mmol) of p-PDA, 0.896 g (2.57 mmol) of C16DAB, 71.5 g of NMP, triethylamine 0 .60 g (5.90 mmol) was added, and the mixture was cooled to about 10 ° C., 21.3 g (77.1 mmol) of DMT-MM was added, and the mixture was allowed to return to room temperature and reacted for 24 hours under a nitrogen atmosphere to give polyamic acid ester (PAE-1) A solution having a concentration of 12% by mass was obtained.

  81.2 g of NMP was added to this polyamic acid (PAE-1) solution, and slowly poured into 1.0 L of methanol cooled to about 10 ° C. with stirring to precipitate a solid. The precipitated solid was collected, further dispersed and washed twice with 500 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 12,300, and the weight average molecular weight was 27,000.

  Γ-BL (80.5 g) was added to 7.00 g of this polyamic acid ester (PAE-1), and the mixture was stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Further, 29.2 g of γ-BL was added to this solution, and the mixture was stirred at 50 ° C. for 20 hours to obtain a polyamic acid ester (PAE-1) 6 mass% and γ-BL 94 mass% solution. (BL-PAE) was obtained.

<Preparation of blend type liquid crystal aligning agent>
40 g of a blending polyamic acid solution (BL-PAA1) prepared in the same manner as in Example 9 was weighed into a 200 mL Erlenmeyer flask, 10.0 g of the prepared polyamic acid ester solution for blending (BL-PAE) was added, and a nitrogen atmosphere was added. Under stirring for 20 hours, a blended liquid crystal aligning agent BL-6 was obtained.

(Example 14)
40 g of a polyamic acid solution for blending (BL-PAA2) prepared in the same manner as in Example 10 was weighed into a 200 mL Erlenmeyer flask, and 10 ml of a polyamic acid ester solution for blending (BL-PAE) prepared in the same manner as in Example 13 was used. 0.0 g was added, and the mixture was stirred for 20 hours under a nitrogen atmosphere to obtain a blended liquid crystal aligning agent BL-7.

(Example 15)
40 g of a polyamic acid solution for blending (BL-PAA3) prepared in the same manner as in Example 11 was weighed into a 200 mL Erlenmeyer flask, and 10 polyamic acid ester solutions for blending (BL-PAE) prepared in the same manner as in Example 13 were used. 0.0 g was added, and the mixture was stirred for 20 hours under a nitrogen atmosphere to obtain a blended liquid crystal aligning agent BL-8.

(Example 16)
40 g of the polyamic acid solution for blending (BL-PAA4) prepared in the same manner as in Example 12 was weighed into a 200 mL Erlenmeyer flask, and 10 ml of the polyamic acid ester solution for blending (BL-PAE) prepared in the same manner as in Example 13 was used. 0.0 g was added, and the mixture was stirred for 20 hours under a nitrogen atmosphere to obtain a blended liquid crystal aligning agent BL-9.

(Comparative Example 4)
40 g of a polyamic acid solution for blending (BL-PAA5) prepared in the same manner as in Comparative Example 3 was weighed into a 200 mL Erlenmeyer flask, and 10 polyamic acid ester solutions for blending (BL-PAE) prepared in the same manner as in Example 13 were used. 0.0 g was added, and the mixture was stirred for 20 hours under a nitrogen atmosphere to obtain a blend liquid crystal aligning agent BL-10 (Comparative Example).

(Test example 1) Varnish (liquid crystal aligning agent) printability test The liquid crystal aligning agent prepared in Examples 1 to 16 and Comparative Examples 1 to 4 was subjected to an alignment film printer (made by Nissha Printing Co., Ltd.). The coating property test was conducted by performing flexographic printing using “Angstromer”). 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 at 50 times with visual observation and an optical microscope ("ECLIPSE ME600" manufactured by Nikon Corporation). Good when no pinholes are observed, poor when pinholes are observed, good if no unevenness in the film thickness at the edge, good if unevenness in the film thickness at the edge Was evaluated as defective. The results are shown in Table 3.

[Production of liquid crystal cell]
About the liquid crystal aligning agent prepared in Examples 1-16 and Comparative Examples 1-4, the liquid crystal cell was produced as follows. A liquid crystal aligning agent is spin-coated on a glass substrate with a transparent electrode, dried on a hot plate at 80 ° C. for 70 seconds, and then baked on a hot plate at 220 ° C. for 10 minutes to form a coating film having a thickness of 100 nm. It was. For the liquid crystal alignment treatment by rubbing, 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. A substrate with a film was obtained.

  After preparing two substrates with a liquid crystal alignment film subjected to the liquid crystal alignment treatment in this manner, a spacer of 6 μm is sprayed on the surface of the one liquid crystal alignment film, and then a sealant is printed thereon, and another sheet is obtained. The substrates were laminated so that the liquid crystal alignment film faces each other and the rubbing direction was orthogonal (twisted nematic liquid crystal cell), and the sealing agent was cured to produce an empty cell. In the twisted nematic cell, liquid crystal MLC-2003 (manufactured by Merck & Co., Inc.) was injected into the empty cell by a reduced pressure injection method, and the injection port was sealed to obtain a twisted nematic liquid crystal cell.

(Test Example 2) Measurement of ion density before and after high-temperature aging test For the liquid crystal cell prepared by the method described in [Preparation of liquid crystal cell] above, the ion density in the initial state was measured and held at 100 ° C. for 30 hours. The ion density was measured after (high temperature aging). In the ion density measurement, the ion density was measured when a triangular wave having a voltage of ± 10 V and a frequency of 0.01 Hz was applied to the liquid crystal cell. The measurement temperature was 80 ° C. As the measuring apparatus, a 6245 type liquid crystal physical property evaluation apparatus manufactured by Toyo Technica Co., Ltd. was used for all measurements. The results are shown in Table 3.

(Test Example 3) Accumulated charge (RDC) measurement before and after the high temperature aging test A DC voltage was applied from 0 V to 1.0 V at a temperature of 23 ° C. to the manufactured liquid crystal cell, and flicker at each voltage was applied. The amplitude level was measured, and a calibration curve for flicker amplitude and applied DC voltage was created. After grounding for 5 minutes, an AC voltage (V ₅₀ ) with half the luminance and a DC voltage of 5.0 V are applied, the flicker amplitude level after 1 hour is measured, and compared with a calibration curve prepared in advance. (Flicker reference method). Thereafter, the DC voltage was set to 0 V, and the RDC relaxation was measured by estimating the RDC after 10 minutes by the same method. The RDC measured in this manner is shown in the column of “RDC after DCon 1h (accumulation) and DCoff 10 min after relaxation” (relaxation) in Table 3. The RDC data shown in Table 3 is the result of RDC after holding the liquid crystal cell at 100 ° C. for 30 hours (high temperature aging).

(Test example 4) Evaluation of orientation The produced liquid crystal cell was observed visually and the orientation state of the liquid crystal was observed. The results are shown in Table 3 with the case where the liquid crystal is aligned without defects being good and the case where the alignment defects are generated is defective.
As a result, Examples 1 to 4 and Comparative Example 1 were evaluated as homopolymers (polyamic acid) of diamine and CBDA, but Examples 1 to 4 using the diamine compound of the present invention were diamines of the present invention. Compared to Comparative Example 1 in which no compound was used, RDC accumulation (RDC value after 1 hour of DCOn) and relaxation (RDC value after 10 minutes of DCoff) were significantly smaller. Moreover, since polyamic acid was used alone, a large difference in printability could not be confirmed, but Examples 1 to 4 had lower ion density than that of Comparative Example 1, both in the initial state and after high-temperature aging, and had practical problems. There was no value. And in Examples 1-4, although the liquid crystal was aligned without a defect, in the comparative example 1, the defect occurred in the liquid crystal and the orientation was bad compared with Examples 1-4.

  Examples 5 to 8 and Comparative Example 2 are evaluated as soluble polyimides, but in Examples 5 to 8 using the diamine of the present invention, soluble polyimides can be produced, and phase separation and precipitation during printing do not occur. There was no pinhole or film unevenness and printability was good. In Examples 5 to 8, the accumulation and relaxation of RDC were also significantly smaller. The ion density was small both in the initial state and after high-temperature aging, and was a value with no practical problem. On the other hand, in Comparative Example 2 using Diamine-5 which is a diamine of Patent Document 3, a soluble polyimide could not be prepared. Moreover, in Examples 5-8, the liquid crystal was aligned without a defect.

  Examples 9-12 and Comparative Example 3 are evaluations of blended materials of soluble polyimide and polyamic acid using the diamine of the present invention, but the diamine of the present invention is excellent in compatibility with soluble polyimide, In the liquid crystal aligning agents of Examples 9 to 12, phase separation and precipitation during printing did not occur, no pinholes and film unevenness, and printability was good. On the other hand, in Comparative Example 3, soluble polyimide and polyamic acid were localized and phase-separated, and separated during the printing test, resulting in poor printability at the edge portion. In Examples 9 to 12, the accumulation and relaxation of RDC were significantly smaller than those in Comparative Example 3. And compared with the comparative example 3, Examples 9-12 had a small ion density after an initial state and high temperature aging, and was a value which is satisfactory practically. In any of Examples 9 to 12, the liquid crystal was aligned without defects.

  In Examples 13 to 16 and Comparative Example 4, the evaluation of blended materials of polyamic acid ester and polyamic acid using the diamine of the present invention, etc., but the diamine of the present invention is compatible with the polyamic acid ester. Therefore, in the liquid crystal aligning agents of Examples 13 to 16, phase separation and precipitation during printing did not occur, pinholes and film unevenness did not occur, and printability was good. On the other hand, the liquid crystal aligning agent of Comparative Example 4 had a poor phase separation property and a tendency to separate during printing as in Comparative Example 3, resulting in poor edge portion printing properties. Further, in Examples 13 to 16, accumulation and relaxation of RDC were significantly smaller than those in Comparative Example 4. In Examples 13 to 16, compared with Comparative Example 4, the ion density was small both in the initial state and after high-temperature aging, and there were no practical problems. In any of Examples 13 to 16, the liquid crystal was aligned without defects.

  From these results, it is confirmed that the liquid crystal aligning agent and the liquid crystal alignment film using the diamine of the present invention can obtain a liquid crystal alignment film having good printability and less accumulated charge and quick relaxation of accumulated charge. It was done.

  The liquid crystal aligning agent using the diamine of the present invention can provide a liquid crystal aligning film having good printability and less accumulated charge and quick relaxation of accumulated charge. 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, such as a TN (Twisted Nematic) liquid crystal display element, an STN liquid crystal display element, a TFT liquid crystal display element, The liquid crystal display device is suitably used for various display devices such as a VA liquid crystal display device, an IPS liquid crystal display device, and an OCB (Optically Self-Compensated Birefringence) liquid crystal display device.

Claims (6)

1,2,3,4-cyclobutanetetracarboxylic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, and 1,2,3,4 -A reaction product of at least one selected from tetracarboxylic acid consisting of dimethyl ester of cyclobutanetetracarboxylic acid and derivatives thereof and a diamine component containing at least one diamine represented by the following formula, polyamic acid or polyamic acid A polyimide precursor comprising an ester.

  2. The polyimide precursor according to claim 1, wherein the diamine is 5 to 95 mol% when the total molar amount of the tetracarboxylic acid and its derivative is 100 mol%.   A polyimide obtained by imidizing the polyimide precursor according to claim 1.   A liquid crystal aligning agent comprising at least one selected from the polyimide precursor according to claim 1 or 2, and the polyimide according to claim 3.   A liquid crystal alignment film comprising a fired product of the liquid crystal alignment agent according to claim 4. A liquid crystal display element comprising the liquid crystal alignment film according to claim 5.