TW201947028A - Liquid crystal alignment agent, liquid crystal aligned film and liquid crystal display device - Google Patents

Abstract

Provided are a liquid crystal alignment agent which makes it possible to obtain a liquid crystal alignment film which has excellent voltage holding ratio, rapid relaxation of accumulated charges, and satisfactory liquid crystal alignment property and transparency, a liquid crystal aligned film, and a liquid crystal display device. The liquid crystal alignment agent includes the following component (A), component (B), and an organic solvent. The component (A) is a polymer of at least one type selected from the group consisting of a polyimide precursor, an imidized polymer of the polyimide precursor, and a photosensitive branched acrylic polymer that exhibits liquid crystallinity in a temperature range of 100 DEG C-300 DEG C. The component (B) is a compound represented by the following formula (1) (Q1, Q2 are each (Q1-1) or the like; either Q1 or Q2 is (Q1-1)) (q1, q2 is 0 or 1; R1 is a hydrogen atom or the like, R2, R3 are each a group having an epoxy moiety, or the like, either R2 or R3 is a group having an epoxy moiety).

Description

Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element

The invention relates to a novel liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element using the same.

Liquid crystal display elements are widely used as display units for computers, mobile phones, smartphones, and televisions. The liquid crystal display element includes, for example, a liquid crystal layer sandwiched between an element substrate and a color filter substrate, a pixel electrode and a common electrode that apply an electric field to the liquid crystal layer, an alignment film that controls the alignment of liquid crystal molecules of the liquid crystal layer, and is provided to pixels. The thin film transistor (TFT) of the electrical signal of the electrode and the like. As a driving method of liquid crystal molecules, a vertical electric field method such as a TN method or a VA method or a lateral electric field method such as an IPS method or an FFS method is known. Compared with the conventional "longitudinal electric field method" in which a voltage is applied to electrodes formed on upper and lower substrates to drive a liquid crystal, the "lateral electric field method" in which an electrode is formed on only one side of a substrate and an electric field is applied in a direction parallel to the substrate has A wide viewing angle characteristic is also known as a liquid crystal display element capable of high-quality display.

Even though the liquid crystal cell of the lateral electric field method has excellent viewing angle characteristics, since there are few electrode portions formed in the substrate, if the voltage retention rate is low, a sufficient voltage is not applied to the liquid crystal. And the contrast of the display will decrease. In addition, if the stability of the liquid crystal alignment is small, when the liquid crystal is driven for a long period of time, the liquid crystal does not return to the initial state and causes a decrease in contrast and image sticking. Therefore, the stability of the liquid crystal alignment is important. Furthermore, static electricity is easily accumulated in the liquid crystal cell. Even if positive and negative asymmetric voltages generated by driving are applied, charges will still be accumulated in the liquid crystal cell, and these accumulated charges will be disordered or residual in the liquid crystal alignment. The form affects the display, and the display quality of the liquid crystal element is significantly reduced.

When used in such a liquid crystal display element with a lateral electric field method, Patent Document 1 discloses a liquid crystal alignment agent having an excellent voltage holding ratio and a reduced charge accumulation, which contains a specific diamine and an aliphatic tetracarboxylic acid. Derivative liquid crystal alignment agent. In addition, as a method for shortening the time until the afterimage disappears, a method using an alignment film having a low volume resistivity such as that of Patent Document 2 or a backlight having a volume resistivity such as that of Patent Document 3 that is not easily received by a liquid crystal display device have been proposed. A method for producing a changing alignment film. However, as the performance of liquid crystal display elements has become higher, the characteristics required for liquid crystal alignment films have become stricter, and it has been difficult for such conventional technologies to fully satisfy all required characteristics.
[Prior technical literature]
[Patent Literature]

[Patent Document 1] International Publication (WO) 2004/021076
[Patent Document 2] International Publication (WO) 2004/053583
[Patent Document 3] International Publication (WO) 2013/008822

[Problems to be Solved by the Invention]

An object of the present invention is to provide a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display device capable of obtaining a liquid crystal alignment film having an excellent voltage holding ratio, rapid relaxation of accumulated charge, and good liquid crystal alignment or transparency.

[Means for solving problems]

The present inventors have completed the present invention in order to solve the above problems as a result of intensive research.
This invention is a liquid crystal aligning agent characterized by containing the following (A) component, (B) component, and an organic solvent.
(A) Ingredient: polymer
(B) component: a compound represented by the following formula (1)

(In the formula, Q ¹ and Q ² are one selected from the following (Q1-1) and a single bond, and at least one of Q ¹ and Q ² is (Q1-1).

q1 and q2 are independently 0 or 1,
R ¹ is a hydrogen atom or a monovalent organic group,
R ² and R ³ are each independently a group having an epoxy site and a hydrogen atom, and at least one of R ² and R ³ is a group having an epoxy site).

[Effect of the invention]

The liquid crystal alignment agent of the present invention can provide a liquid crystal alignment film and a liquid crystal display element having excellent voltage retention, rapid relaxation of accumulated charge, and good liquid crystal alignment or transparency, and excellent display characteristics.
The reason why the above-mentioned problems can be solved by the present invention is not clear, but it can be considered as follows. The structure of the compound represented by said Formula (1) contained in the liquid crystal aligning agent of this invention has a conjugated structure. Therefore, for example, in a liquid crystal alignment film, it is possible to promote the movement of electric charges, and to promote the relaxation of accumulated electric charges.

[Best Mode for Implementing Invention]

＜ (A) component ＞
The component (A) contained in the liquid crystal alignment agent of the present invention is selected from the group consisting of a polyimide precursor, a polyimidized polymer of the polyimide precursor, and a liquid crystal exhibited in a specified temperature range. A polymer of at least one of the group consisting of a photosensitive photosensitive side chain acrylic polymer.

＜ Polyimide precursors ＞
The polyfluorene imide precursor of the component (A) has a structural unit represented by the following formula (A1).

In the formula (A1), X ₁ is a tetravalent organic group, and Y ₁ is a divalent organic group.
R ₁ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and A ₁ and A ₂ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms that may have a substituent, and 2 to 10 carbon atoms that may have a substituent Alkenyl or alkynyl having 2 to 10 carbon atoms which may have a substituent.
Specific examples of the alkyl group in R ₁ include methyl, ethyl, propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, and n- Amyl and others. From the viewpoint that the imidization can be easily performed by heating, R _{1 is} preferably a hydrogen atom or a methyl group.

X ₁ is a tetravalent organic group derived from a tetracarboxylic acid derivative, and the structure is not particularly limited. In the polyimide precursor, two or more kinds of X ₁ may be mixed.
Specific examples of X ₁ include a structure of the following formulae (X-1) to (X-44).

R ₈ to R _{11 in} the formula (X-1) are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, or Phenyl. When R ₈ to R _{11 have} a large-volume structure, the alignment of the liquid crystal may be reduced. Therefore, a hydrogen atom, a methyl group, or an ethyl group is more preferred, and a hydrogen atom or a methyl group is particularly preferred.

X ₁ is preferably a structure selected from the formulae (X-1) to (X-14) from the viewpoint of the availability of the monomer.
As a preferable ratio of the structure selected from the above formulae (X-1) to (X-14), it is 20 mol% or more of X ₁ as a whole, more preferably 60 mol% or more, and more preferably 80 More than%.

A ₁ and A ₂ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbons which may have a substituent, an alkenyl group having 2 to 10 carbons which may have a substituent, or 2 to 10 carbon atoms which may have a substituent. Alkynyl.
Specific examples of the alkyl group include methyl, ethyl, propyl, butyl, t-butyl, hexyl, octyl, decyl, cyclopentyl, cyclohexyl, and dicyclohexyl.

Examples of the alkenyl group include a structure in which one or more CH ₂ -CH ₂ structures existing in the alkyl group are replaced with a CH = CH structure. Specific examples include vinyl, allyl, 1-propenyl, isopropenyl, 2-butenyl, 1,3-butadienyl, 2-pentenyl, 2-hexenyl, and cyclo Propylene, cyclopentenyl, cyclohexenyl and the like.
Examples of the alkynyl group include those in which one or more CH ₂ -CH ₂ structures existing in the aforementioned alkyl group are replaced with a C≡C structure. Specific examples include ethynyl, 1-propynyl, and 2-propynyl.

The above-mentioned alkyl group, alkenyl group, and alkynyl group may have a substituent, and may further form a ring structure by the substituent. However, the term "ring structure formed by a substituent" means that the substituents are bonded to each other or that the substituent and a part of the parent skeleton form a ring structure.
Examples of the substituent include a halogen group, a hydroxyl group, a thiol group, a nitro group, an aryl group, an organic oxy group, an organic thio group, an organic silyl group, a fluorenyl group, an ester group, a thioester group, and a phosphate group , Amido, alkyl, alkenyl, alkynyl, and the like.

Examples of the halogen group as a substituent include a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.
Examples of the aryl group as a substituent include a phenyl group. The aryl group may be further substituted with another substituent described above.

The organic oxy group of the substituent can be represented by a structure represented by -O-R. The R may be the same or different, and examples thereof include the aforementioned alkyl, alkenyl, alkynyl, and aryl groups. Such R may be further substituted with the aforementioned substituent. Specific examples of the organic oxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, and an octyloxy group.

The organic thio group of the substituent can be represented by a structure represented by -S-R. Examples of the R include the aforementioned alkyl, alkenyl, alkynyl, and aryl groups. Such R may be further substituted with the aforementioned substituent. Specific examples of the organic thio group include methylthio, ethylthio, propylthio, butylthio, pentylthio, hexylthio, heptylthio, and octylthio.

The organosilyl group having a substituent can be represented by a structure represented by -Si- (R) ₃ . The R may be the same or different, and examples thereof include the aforementioned alkyl, alkenyl, alkynyl, and aryl groups. Such R may be further substituted with the aforementioned substituent. Specific examples of the organosilyl group include trimethylsilyl, triethylsilyl, tripropylsilyl, tributylsilyl, tripentylsilyl, trihexylsilyl, and the like. Amyldimethylsilyl, hexyldimethylsilyl and the like.

The fluorenyl group of a substituent can be represented by the structure represented by -C (O) -R. Examples of the R include the aforementioned alkyl, alkenyl, and aryl groups. Such R may be further substituted with the aforementioned substituent. Specific examples of the fluorenyl group include methyl fluorenyl, ethyl fluorenyl, propyl fluorenyl, butyl fluorenyl, isobutyl fluorenyl, pentyl fluorenyl, isopentyl fluorenyl, and benzyl fluorenyl.

The ester group of a substituent can be represented by the structure represented by -C (O) O-R or -OC (O) -R. Examples of the R include the aforementioned alkyl, alkenyl, alkynyl, and aryl groups. Such R may be further substituted with the aforementioned substituent.

The thioester group of the substituent may be -C (S) OR, or
-OC (S) -R. Examples of the R include the aforementioned alkyl, alkenyl, alkynyl, and aryl groups. Such R may be further substituted with the aforementioned substituent.

The phosphate group of the substituent can be represented by a structure represented by -OP (O)-(OR) ₂ . The R may be the same or different, and examples thereof include the aforementioned alkyl, alkenyl, alkynyl, and aryl groups. Such R may be further substituted with the aforementioned substituent.

The amido group of the substituent may be -C (O) NH ₂ or
Structures represented by -C (O) NHR, -NHC (O) R, -C (O) N (R) ₂ , and -NRC (O) R are shown. The R may be the same or different, and examples thereof include the aforementioned alkyl, alkenyl, alkynyl, and aryl groups. Such R may be further substituted with the aforementioned substituent.

Examples of the aryl group of the substituent include the same as the aryl group. The aryl group may be further substituted with another substituent described above.
Examples of the alkyl group as the substituent are the same as those described above. This alkyl group may be further substituted with the other substituent mentioned above.
Examples of the alkenyl group as the substituent are the same as the aforementioned alkenyl group. The alkenyl group may be further substituted with the other substituents described above.
Examples of the alkynyl group as the substituent are the same as those described above. The alkynyl group may be further substituted with another substituent described above.

In general, when a large-sized structure is introduced, the reactivity of the amine group or the alignment of the liquid crystal may be reduced. Therefore, as the A ₁ and A ₂ , a hydrogen atom or a carbon number of 1 to 4 may be substituted. A 5 alkyl group is more preferable, and a hydrogen atom, a methyl group or an ethyl group is particularly preferable.

Y ₁ is a divalent organic group derived from a diamine, and the structure is not particularly limited. Specific examples of Y ₁ include the following formulae (Y-1) to (Y-119).

In the formula (Y-109), m and n are each an integer of 1 to 11, and m + n is an integer of 2 to 12.
In formula (Y-114), h is an integer of 1 to 3, and in formulas (Y-111) and (Y-117), j is an integer of 0 to 3.
From the viewpoint of liquid crystal alignment or pretilt angle of the obtained liquid crystal alignment film, Y ₁ is preferably at least one selected from the group consisting of the structures represented by the following formulae (5) and (6).

In formula (5), R ₁₂ is a single bond or a divalent organic group having 1 to 30 carbon atoms, R ₁₃ is a hydrogen atom, a halogen atom, or a monovalent organic group having 1 to 30 carbon atoms, and a is an integer of 1 to 4 . When a is 2 or more, R ₁₂ and R ₁₃ may be the same or different from each other.
In formula (6), R ₁₄ is a single bond, -O-, -S-, -NR _15- , amine bond, ester bond, urea bond, or a divalent organic group having 1 to 40 carbon atoms, and R ₁₅ is hydrogen Atom or methyl.

Specific examples of Y ₁ represented by the formulae (5) and (6) include the following structures among the formulae (Y-1) to (Y-119).
Y ₁ with a highly linear structure can improve the alignment of the liquid crystal when it is made into a liquid crystal alignment film. Therefore, the formula (Y-7), (Y-21), (Y-22), (Y-23), (Y-25), (Y-43), (Y-44), (Y-45), (Y-46), (Y-48), (Y-63), (Y-71), (Y -72), (Y-73), (Y-74), (Y-75), (Y-98), (Y-99), (Y-100), or (Y-118) are preferred.
Ratio can be improved configuration of the liquid crystal alignment property of Y _1, Y ₁ in more than 20 mole% of the entire preferred, and preferably less than 60 mole%, more preferably at least 80 mole%.

In order to increase the pretilt angle of the liquid crystal when forming a liquid crystal alignment film, Y _{1 is} preferably a structure having a long-chain alkyl group, an aromatic ring, an aliphatic ring, a steroid skeleton, or a combination of these in the side chain. As such Y ₁ , the formulae (Y-76) to (Y-97) are preferred. When the pre-tilt angle is to be increased, the ratio of the structure of Y ₁ described above is preferably 1-30 mol% of Y ₁ as a whole, and 1-20 mol% is more preferable.
When a polyfluorene imide precursor or a polyfluorene imine having a photo-alignment side chain is used as the polymer of the component (A), the polyfluorene imide precursor or the polyfluorene imide is as follows: The photoreactive side chain is preferred.

(In formula (c), R ⁶ represents -CH _2- , -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -CH ₂ O-, -N (CH ₃ )-, -CON (CH ₃ ) -or
-N (CH ₃ ) CO-. R ⁷ represents a cyclic, unsubstituted or fluorine-substituted alkylene group having 1 to 20 carbon atoms (arbitrary -CH _2- , which may be replaced by -CF ₂ -or
-CH = CH-, or may be substituted by any of the groups listed below (not as a group: -O-, -COO-, -OCO-
, -NHCO-, -CONH-, -NH-, carbocyclic or heterocyclic))). R ⁸ means
-CH _2- , -O-, -COO-, -OCO-, -NHCO-, -NH-, -N (CH ₃ )-
, -CON (CH ₃ )-, -N (CH ₃ ) CO-, a carbocyclic or heterocyclic ring. R ⁹ represents a vinylphenyl group, -CR ¹⁰ = CH ₂ group, -CR ¹⁰ (OH) -CH ₃ group, a carbocyclic ring, a heterocyclic ring, or a structure represented by the following formula, and R ¹⁰ represents a structure capable of being represented by a hydrogen atom or Fluorine atom substituted methyl).

When manufacturing the said polyfluorene imide precursor, as a diamine, it is convenient to use the diamine substituted by the side chain represented by said Formula (c).
A polyimide precursor having a photo-alignment group in the main chain may also be used. In this case, it is convenient to use a diamine having a bond containing a photo-alignment group between the amine and the amine, as represented by the following formula (2).

In formula (2), X ¹ is a single bond or an alkylene group having 1 to 5 carbon atoms, X ² is -OCO-CH = CH- or -CH = CH-COO-, and X ³ is a single bond and carbon number 1 ~ 10 alkylene or divalent benzene ring, X ⁴ is a single bond, -OCO-CH = CH- or -CH = CH-COO-, and X ⁵ is a single bond or an alkylene having 1 to 5 carbon atoms. However, it has more than 1 cassia hydrazone.

Examples of the diamine represented by the formula (2) include the following formulae (2-a) to (2-d).

In the formula, X is a bonding group selected from a single bond or an ether (-O-), an ester (-COO- or OCO-), and an amine (-CONH- or NHCO-), and Y is a single bond or a carbon number 1 to 5 alkylene, Z is an alkylene or phenylene having 1 to 10 carbon atoms. The bonding position of the amine group on the benzene ring or the position of the bonding group with respect to the central benzene ring is not particularly limited.

Moreover, as a specific example of the diamine represented by Formula (2), the following diamine is mentioned.

Liquid crystal alignment using a polyimide precursor such as a polyamic acid or a polyamic acid ester of the present invention containing a diamine represented by the above formula (2) as a raw material, a polyimide, or a polyamine The liquid crystal alignment film formed by the agent can reduce a change in alignment performance of the liquid crystal (for example, a change in alignment orientation of the liquid crystal) caused by AC (Alternating Current) driving. Therefore, in a liquid crystal display element having the liquid crystal alignment film, the liquid crystal alignment performance of the liquid crystal alignment film under AC driving is stable, so that an afterimage caused by AC driving is unlikely to occur. That is, an effect such that the afterimage characteristics caused by the AC driving is extremely good can be exhibited.
In addition, the liquid crystal alignment film formed using the diamine represented by the above formula (2) has excellent liquid crystal alignment performance itself, and can realize a liquid crystal alignment film having substantially no alignment defects.
The polyfluorene imide precursor used in the present invention is obtained by reacting a diamine component and a tetracarboxylic acid derivative, and examples thereof include polyamic acid or polyamic acid esters.

＜ Production of Polyimide Precursor (Polyamidate) ＞
The polyamidic acid which is a polyamido precursor used in the present invention can be produced by the following method. Specifically, it can be obtained by mixing tetracarboxylic dianhydride and diamine in the presence of an organic solvent at -20 to 150 ° C (preferably 0 to 50 ° C) for 30 minutes to 24 hours (preferably 1 to 12 hours).

The reaction of the diamine component and the tetracarboxylic acid component is generally performed in an organic solvent. The organic solvent used at this time is not particularly limited as long as it can dissolve the produced polyimide precursor. Specific examples of the organic solvent used in the reaction are given below, but they are not limited to these examples. Examples include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone, N, N-dimethylformamidine, N, N-dimethyl Acetamide, dimethylarsine or 1,3-dimethyl-imidazolidone.
When the solubility of the polyimide precursor is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or the following formula [ D-1] to an organic solvent represented by the formula [D-3].

In formula [D-1], D ¹ represents an alkyl group having 1 to 3 carbon atoms, in formula [D-2], D ² represents an alkyl group having 1 to 3 carbon atoms, and in formula [D-3], D ³ C1-C4 alkyl group.
These organic solvents may be used alone or in combination. Furthermore, even if it is a solvent which does not dissolve a polyfluorene imide precursor, it can mix and use in the said solvent within the range which the produced | generated polyfluorene imide precursor does not precipitate. In addition, since the water in the organic solvent may hinder the polymerization reaction and cause hydrolysis of the produced polyimide precursor, the organic solvent is preferably one that has been dehydrated and dried.

The concentration of the polyamic acid polymer in the reaction system is from 1 to 30% by mass, and from 5 to 20% by mass, from the viewpoint that it is difficult to cause precipitation of the polymer and it is easy to obtain a high molecular weight body. Better.

The polyamino acid obtained in the manner described above can be precipitated and recovered by pouring a polymer into a poor solvent while sufficiently stirring the reaction solution. Furthermore, after carrying out precipitation multiple times, washing with a poor solvent, and drying at normal temperature or heating, a purified polyamic acid powder can be obtained. The poor solvent is not particularly limited, and examples thereof include water, methanol, ethanol, hexane, butylcellulose, acetone, and toluene.

＜ Production of Polyimide Precursor (Polyamidate) ＞
The polyamidate which is a polyamidate precursor used in the present invention can be produced by the production method (1), (2), or (3) shown below.

(1) In the case of production from polyamic acid, a polyamic acid ester can be produced by esterifying the polyamino acid produced as described above. Specifically, the polyamidic acid and the esterifying agent can be used in the presence of an organic solvent at -20 to 150 ° C, preferably 0 to 50 ° C, for 30 minutes to 24 hours, preferably 1 to It was made by reacting for 4 hours.

The esterifying agent is preferably one which can be easily removed by purification, and examples thereof include N, N-dimethylformamide dimethyl acetal, and N, N-dimethylformamide diethyl Acetal, N, N-dimethylformamide dipropyl acetal, N, N-dimethylformamide dineopentylbutyl acetal, N, N-dimethylformamide di- t-butyl acetal, 1-methyl-3-p-toluene triazene, 1-ethyl-3-p-toluene triazene, 1-propyl-3-p-toluene triazene, 4 -(4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium chloride and the like. The addition amount of the esterifying agent is preferably 2 to 6 mol equivalents relative to 1 mol of the repeating unit of polyamic acid.

Examples of the organic solvent include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone, N, N-dimethylformamide, N, N -Dimethylacetamide, dimethylarsine or 1,3-dimethyl-imidazolidone. When the solvent solubility of the polyfluorene imide precursor is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or the formula [D -1] to the organic solvent represented by the formula [D-3].

These organic solvents may be used alone or in combination. Furthermore, even if it is a solvent which does not dissolve a polyfluorene imide precursor, it can mix and use in the said solvent within the range which the produced | generated polyfluorene imide precursor does not precipitate. In addition, since the water in the organic solvent may hinder the polymerization reaction and cause hydrolysis of the produced polyimide precursor, the organic solvent is preferably one that has been dehydrated and dried.
The solvent used in the above reaction is preferably N, N-dimethylformamide, N-methyl-2-pyrrolidone or γ-butyrolactone in terms of the solubility of the polymer. Etc. can be used by mixing 1 type or 2 or more types. The concentration at the time of production is preferably 1 to 30% by mass, and more preferably 5 to 20% by mass, from the viewpoint that it is difficult to cause precipitation of a polymer and it is easy to obtain a high molecular weight body.

(2) When produced by the reaction of a tetracarboxylic acid diester dichloride and a diamine, a polyamidate system can be produced from a tetracarboxylic acid diester dichloride and a diamine. Specifically, the tetracarboxylic acid diester dichloride and diamine can be used in the presence of a base and an organic solvent at -20 to 150 ° C, preferably 0 to 50 ° C, for 30 minutes to 24 hours. It is preferably produced by reacting for 1 to 4 hours.

As the base system, pyridine, triethylamine, 4-dimethylaminopyridine, or the like can be used, but in order to stabilize the reaction, pyridine is preferred. The amount of the alkali added is preferably 2 to 4 times the mole of the tetracarboxylic acid diester dichloride in terms of an amount that can be easily removed and a high molecular weight body can be easily obtained.

As the organic solvent, in terms of the solubility of the monomer and the polymer, N-methyl-2-pyrrolidone or γ-butyrolactone is preferred, and one or two or more of them may be mixed. use.
The polymer concentration at the time of production is preferably 1 to 30% by mass, and more preferably 5 to 20% by mass, from the viewpoint that it is difficult to cause precipitation of a polymer and it is easy to obtain a high molecular weight body. In addition, in order to prevent the hydrolysis of the tetracarboxylic acid diester dichloride, it is preferable that the organic solvent used in the production of the polyamic acid ester is dehydrated as much as possible, and in a nitrogen environment to prevent the mixing of outside air Is better.

(3) When it is produced from a tetracarboxylic acid diester and a diamine, a polyamidate system can be produced by polycondensation of a tetracarboxylic acid diester and a diamine. Specifically, it is possible to use a tetracarboxylic diester and a diamine in the presence of a condensing agent, a base, and an organic solvent at 0 to 150 ° C, preferably 0 to 100 ° C, for 30 minutes to 24 minutes. It is preferably produced by reacting for 3 to 15 hours.

As the aforementioned condensing agent system, triphenylphosphite, dicyclohexylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, N, N'-carbonyldiimidazole, dimethoxy-1,3,5-triazinylmethylmorpholinium, O- (benzotriazol-1-yl) -N, N, N ', N' -Tetramethylurea tetrafluoroborate, O- (benzotriazol-1-yl) -N, N, N ', N'-tetramethylurea hexafluorophosphate, (2,3-dihydro- 2-thioketo-3-benzoxazolyl) phosphonic acid diphenyl ester and the like. The addition amount of the condensing agent is preferably 2 to 3 times the mole of the tetracarboxylic acid diester.

Examples of the base include tertiary amines such as pyridine and triethylamine. The amount of the alkali added is preferably 2 to 4 times the mole of the diamine component in terms of the amount that can be easily removed and the high-molecular-weight body can be easily obtained.
In the above reaction, the reaction can be efficiently performed by adding a Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferred. The amount of the Lewis acid to be added is preferably 0 to 1.0 times mole compared to the diamine component.

In order to obtain a high molecular weight polyamidate in the manufacturing method of the said 3 types of polyamidates, the manufacturing method of said (1) or (2) is especially preferable.
The polymer solution obtained in the manner described above can be precipitated by pouring the polymer into a poor solvent while stirring it sufficiently. After carrying out precipitation many times, washing with a poor solvent, and then drying at room temperature or heating, a purified polyurethane powder can be obtained. The poor solvent is not particularly limited, and examples thereof include water, methanol, ethanol, hexane, butylcellulose, acetone, and toluene.

＜ Polyimide ＞
The polyfluorene imine (fluorene imidized polymer in the component (A)) used in the present invention can be produced by fluorinating the aforementioned polyfluorene ester or polyamic acid.

In the case of producing polyimide from polyacrylic acid, a chemical diamine that reacts by adding a catalyst to a solution of the polyamidic acid obtained by reacting a diamine component with a tetracarboxylic dianhydride is added. Amination is simple. The chemical fluorene imidization is preferred because the fluorene imidization reaction is performed at a relatively low temperature, so that the molecular weight of the polymer is unlikely to decrease during the fluorene imidization.
The chemical fluorene imidization can be performed by stirring a polyfluorine acid to be fluorinated in an organic solvent in the presence of a basic catalyst and an acid anhydride. As the organic solvent, the organic solvent used in the aforementioned polymerization reaction can be used. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Among them, pyridine is preferred because it has a moderate basicity for the reaction to proceed. In addition, examples of the acid anhydride include acetic anhydride, trimellitic anhydride, and pyromellitic dianhydride. Among them, when acetic anhydride is used, purification after the reaction is facilitated, which is preferable.

The temperature at which the arsine imidization reaction is performed is -20 to 140 ° C, preferably 0 to 100 ° C, and the reaction time may be 0.5 to 100 hours, preferably 1 to 80 hours. The amount of alkaline catalyst is 0.5 to 30 mol times, preferably 2 to 20 mol times, and the amount of acid anhydride is 1 to 50 mol times, preferably 3 to 30 mol times. Ear times. The hydrazone imidization rate of the obtained polymer can be controlled by adjusting the amount of catalyst, temperature, and reaction time.

Since the added catalyst and the like remain in the solution after the polyimidation reaction of the polyimide or polyamic acid, the obtained imidized polymer is recovered by the method described below. After redissolving with an organic solvent, it is preferably used as the component (A) of the liquid crystal alignment agent of the present invention.
The solution of the polyimide obtained in the manner described above can be poured into a poor solvent while being sufficiently stirred to precipitate a polymer. After carrying out precipitation many times, washing with a poor solvent, and drying at normal temperature or heating, a purified polyimide powder can be obtained.
The poor solvent is not particularly limited, and examples thereof include methanol, acetone, hexane, butyl cyperidine, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, and benzene.

＜ Side-chain acrylic polymer ＞
The side chain type acrylic polymer, which is one aspect of the component (A) of the present invention, exhibits liquid crystallinity and has photosensitivity in a specified temperature range.
The side chain acrylic polymer preferably reacts with light in a wavelength range of 200 to 450 nm, and preferably exhibits liquid crystallinity in a temperature range of 100 to 300 ° C.
As the side chain type acrylic polymer, it is preferable to have a photosensitive side chain having a photosensitive side chain that reacts with light in a wavelength range of preferably 200 to 450 nm (and more preferably 250 to 400 nm). .
As the side chain type acrylic polymer, it is preferable to have a mesogenic group as follows: for exhibiting liquid crystal in a temperature range of preferably 100 to 350 ° C (also preferably 120 to 300 ° C) Liquid crystal based.

The side chain type acrylic polymer is bonded to a side chain having a photosensitive main chain. Therefore, it can cause a crosslinking reaction, an isomerization reaction, or a light Fries rearrangement by light induction. The structure of the photosensitive side chain is preferably one that causes a cross-linking reaction or photo-Fries rearrangement by light induction, and more preferably one that causes a cross-linking reaction. At this time, even if it is exposed to external stress such as heat, the achieved alignment control ability can be stably maintained for a long time.
The structure of the photosensitive side-chain acrylic polymer film capable of exhibiting liquid crystallinity is not particularly limited as long as it satisfies such characteristics, but it is preferable that the side-chain structure has a rigid liquid crystal-based component. In this case, when the side-chain acrylic polymer is made into a liquid crystal alignment film, stable liquid crystal alignment can be obtained.

The structure of the side chain acrylic polymer is preferably, for example, a structure having a main chain and a side chain bonded to the main chain, and the side chain having biphenyl, terphenyl, and phenylcyclohexyl Structures of liquid crystal-based components such as phenylbenzoate group and azophenyl group, and a photosensitive group that is bonded to the tip and undergoes a crosslinking reaction or an isomerization reaction to light; or And a side chain bonded to the main chain, the side chain being a liquid crystal-based component and having a structure of a phenylbenzoate group that undergoes a photo-Fries rearrangement reaction.

As a specific example of the structure of the side chain type acrylic polymer, a structure having the following main chain and side chain is preferred: the main chain is derived from a hydrocarbon selected from (meth) acrylate, econate, Compounds of at least one of the group consisting of fumarate, maleate, α-methylene-γ-butyrolactone, styrene, vinyl, maleimide, and norbornene The freely polymerizable group has a side chain composed of at least one of the following formulae (i) to (v).

In the formula, Ar ₁ represents a divalent substituent obtained by removing two hydrogen atoms from a benzene ring, a naphthalene ring, a pyrrole ring, a furan ring, a thiophene ring, or a pyridine ring.
Ar ₂ and Ar ₃ are each independently a divalent substituent obtained by removing two hydrogen atoms from a benzene ring, a naphthalene ring, a pyrrole ring, a furan ring, a thiophene ring, or a pyridine ring. One of q1 and q2 is 1 and the other is 0.
Ar ₄ and Ar ₅ each independently represent a divalent substituent obtained by removing two hydrogen atoms from a benzene ring, a naphthalene ring, a pyrrole ring, a furan ring, a thiophene ring, or a pyridine ring. Y ₁ -Y ₂ represents -CH = CH-, -CH = N-, -N = CH-, or -C≡C-.

S ₁ , S ₂ and S ₃ each independently represent a single bond, a straight or branched alkylene group having 1 to 18 carbon atoms, a cycloalkylene group having 5 to 8 carbon atoms, a phenylene group or a phenylene group, Or represents one or more types of bonds selected from single bonds, ether bonds, ester bonds, amido bonds, urea bonds, urethane bonds, amine bonds, carbonyl groups, or combinations thereof, or It means that a linear or branched alkylene group having 1 to 18 carbon atoms, a cycloalkylene group having 5 to 8 carbon atoms, a phenylene group, a biphenylene group, or a combination thereof is selected through the aforementioned bond. In the structure, 2 to 10 parts are connected. The divalent substituent may have a structure in which a plurality of the divalent substituents are connected to each other through the bond.

R ₁₁ represents a hydrogen atom, a hydroxyl group, a mercapto group, an amine group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylamino group having 1 to 8 carbon atoms, or a two to 16 carbon atom. Alkylamino.
The benzene ring and / or naphthalene ring system may be substituted with the same or different 1 or more groups selected from a halogen atom, a cyano group, a nitro group, a carboxyl group, and an alkoxycarbonyl group having 2 to 11 carbon atoms. At this time, the alkyl group having 1 to 10 carbon atoms may be linear, branched, or cyclic, may have a combination of these structures, or may be substituted with a halogen atom.

The side chain type acrylic polymer of the present invention preferably contains a liquid crystal side chain.
The liquid crystal group in the liquid crystal side chain may be a group that has a liquid crystal group structure alone such as biphenyl or phenylbenzoate, or may be formed by hydrogen bonding of side chains such as benzoic acid and the like. Liquid crystal based structure. The liquid crystal group possessed as a side chain preferably has the following structure.

＜ Side-chain acrylic polymer ＞
The side chain type acrylic polymer of the present invention can be obtained by polymerizing a photoreactive side chain monomer and a liquid crystal side chain monomer having the above-mentioned photosensitive side chain.

[Photoreactive side chain monomer]
The photo-reactive side chain monomer refers to a polymer having a photosensitive side chain at a side chain site where the monomer can form a polymer when the monomer is formed into a polymer.
The photoreactive group having a side chain is preferably a structure represented by the formulae (i) to (v).
More specific examples of the photoreactive side chain monomer are preferably those having a material selected from the group consisting of hydrocarbons, (meth) acrylates, econate, fumarate, maleate, and α-methylene-γ. -A freely polymerizable group of at least one compound in the group consisting of butyrolactone, styrene, vinyl, maleimide, and norbornene, and selected from the group consisting of the formulae (i) to (v) Structure made of at least one type of photosensitive side chain in the group.

[Liquid crystal side chain monomer]
The so-called liquid crystal side chain single system means a polymer derived from the monomer is a monomer that exhibits liquid crystallinity, and the polymer can form a liquid crystal group at a side chain portion.
More specific examples of the liquid crystalline side chain monomer preferably have a material selected from the group consisting of hydrocarbons, (meth) acrylates, econate, fumarate, maleate, α-methylene-γ- A freely polymerizable group of at least one compound from the group consisting of butyrolactone, styrene, vinyl, maleimide, and norbornene, and having a group selected from the group consisting of the aforementioned liquid crystal groups Structure of at least one type of liquid crystal side chain.

The side chain type acrylic polymer of the present invention can be obtained by the above-mentioned polymerization reaction of a photoreactive side chain monomer exhibiting liquid crystallinity. In addition, it is also possible to copolymerize a photoreactive side chain monomer and a liquid crystal side chain monomer that do not exhibit liquid crystallinity, or a photoreactive side chain monomer and a liquid crystal side chain monomer that exhibit liquid crystallinity. Copolymerization. Furthermore, it can be copolymerized with other monomers within a range that does not impair the ability to exhibit liquid crystallinity.

Examples of other monomers include monomers that are commercially available and can undergo a free polymerization reaction.
Specific examples of other monomers include unsaturated carboxylic acid, acrylate, methacrylate, maleimide, acrylonitrile, maleic anhydride, styrene compound, vinyl compound, and the like.

Specific examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, maleic acid, and fumaric acid.
Examples of the acrylate include methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, anthryl acrylate, anthryl methyl acrylate, phenyl acrylate, and acrylic acid 2,2, 2-trifluoroethyl, tert-butyl acrylate, cyclohexyl acrylate, isoamyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, 2-ethoxyethyl acrylate Ester, tetrahydrofurfuryl acrylate, 3-methoxybutyl acrylate, 2-methyl-2-adamantyl acrylate, 2-propyl-2-adamantyl acrylate, 8-methyl-8 acrylate -Tricyclodecyl ester, 8-ethyl-8-tricyclodecyl acrylate and the like.

Examples of the methacrylate include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, benzyl methacrylate, naphthyl methacrylate, anthryl methacrylate, Anthryl methyl methacrylate, phenyl methacrylate, 2,2,2-trifluoroethyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, isofluorenyl methacrylate Ester, 2-methoxyethyl methacrylate, methoxytriethylene glycol methacrylate, 2-ethoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 3-methyl methacrylate Oxybutyl, 2-methyl-2-adamantyl methacrylate, 2-propyl-2--adamantyl methacrylate, 8-methyl-8-tricyclodecyl methacrylate , And 8-ethyl-8-tricyclodecyl methacrylate. Furthermore, glycidyl (meth) acrylate, (3-methyl-3-oxetanyl) methyl (meth) acrylate, and (3-ethyl-3- (Meth) acrylate compounds having a cyclic ether group such as oxetanyl) methyl ester.

Examples of the vinyl compound include vinyl ether, methyl vinyl ether, benzyl vinyl ether, 2-hydroxyethyl vinyl ether, phenyl vinyl ether, and propyl vinyl ether.
Examples of the styrene compound include styrene, methylstyrene, chlorostyrene, and bromostyrene.
Examples of the maleimide compound include maleimide, N-methylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide, and the like.

The manufacturing method of the side chain type acrylic polymer of this invention is not specifically limited, The general method used industrially can be utilized. Specifically, it can be manufactured by cation polymerization, free polymerization, anion polymerization, and the like using a vinyl group of a liquid crystalline side chain monomer or a photoreactive side chain monomer. Among these, from the viewpoints of ease of reaction control and the like, free polymerization is particularly preferable.

As the free-polymerization polymerization initiator, a well-known free polymerization initiator such as AIBN (azobisisobutyronitrile) or a well-known compound such as a reversible addition-cracking type chain transfer (RAFT) polymerization reagent can be used.
The free polymerization method is not particularly limited, and an emulsion polymerization method, a suspension polymerization method, a dispersion polymerization method, a precipitation polymerization method, a block polymerization method, a solution polymerization method, and the like can be used.

The organic solvent used in the polymerization reaction of the side-chain acrylic polymer is not particularly limited as long as the polymer produced is a solvent. Specific examples are given below.
N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactone Phenylamine, dimethyl sulfene, tetramethyl urea, pyridine, dimethyl fluorene, hexamethyl fluorene, γ-butyrolactone, isopropyl alcohol, methoxymethylpentanol, dipentene, ethyl Pentyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cyperidine, ethyl cyperidine, methyl cellosolve acetic acid Ester, ethyl cellosolve acetate, butylcarbitol, ethylcarbitol, 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 diethylene glycol Methyl 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 mono Acetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropyl Glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, sesquibutene, pentyl acetate, butyl butyrate, butyl ether, diiso Butyl ketone, methyl cyclohexene, propyl ether, dihexyl ether, dioxane, tetrahydrofuran, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, carbonic acid Ethyl acetate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, 3-methyl Methyl propionate, methyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxy Propyl propionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N, N-dimethylpropane Ammonium amine, 3-ethoxy-N, N-dimethylpropylamine, 3-butoxy-N, N-dimethylpropylamine and the like.

These organic solvents may be used alone or in combination. Furthermore, even if it is a solvent which does not melt | dissolve the produced | generated polymer, as long as the produced | generated polymer does not precipitate, it can mix and use with the said organic solvent.
In the free polymerization, since the oxygen in the organic solvent is a factor that hinders the polymerization reaction, the organic solvent is preferably one that is degassed as much as possible.
The polymerization temperature during free polymerization can be selected at any temperature from 30 to 150 ° C, and is preferably in the range of 50 to 100 ° C.

In addition, the reaction system can be carried out at any concentration, but when the concentration is too low, it becomes difficult to obtain a polymer with a high molecular weight. When the concentration is too high, the viscosity of the reaction solution becomes too high and uniform stirring becomes possible. Difficult, the monomer concentration is preferably 1 to 50% by mass, and more preferably 5 to 30% by mass. The reaction is performed at a high concentration in the initial stage, and thereafter, it is preferable to add an organic solvent.
In the above-mentioned free polymerization reaction, when the ratio of the free polymerization initiator to the monomer is large, the molecular weight of the obtained polymer becomes small, and when it is small, the molecular weight of the obtained polymer becomes large. The ratio of the initiator to the polymerized monomer is preferably 0.05 to 15 mol%, and more preferably 0.1 to 10 mol%. In addition, various monomer components, organic solvents, free polymerization initiators, and the like may be added during polymerization.

When recovering a polymer produced from a reaction solution containing a side chain-type acrylic polymer obtained by the above-mentioned polymerization reaction, it is preferable that the reaction solution is put into a poor solvent to precipitate the polymer produced. Examples of poor solvents used during precipitation include methanol, acetone, hexane, heptane, butylcythrene, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, and Ethyl ether, methyl ethyl ether, water, etc. The polymer system which is put into a poor solvent and precipitated is filtered and recovered, and then it is preferably dried at normal temperature or heating under normal pressure or reduced pressure. In addition, when the polymer precipitated and recovered is redissolved in an organic solvent, and the operation of reprecipitation and recovery is repeated 2 to 10 times, impurities in the polymer can be reduced. Examples of the poor solvent at the time of reprecipitation include alcohols, ketones, ethers, and hydrocarbons. When three or more kinds of poor solvents selected from these are used, the efficiency of purification is further improved. Better.

The molecular weight of the side chain acrylic polymer of the present invention is measured by GPC (Gel Permeation Chromatography) method when considering the strength of the obtained coating film, workability during coating film formation, and uniformity of the coating film. The average molecular weight is preferably 2,000 to 500,000, and more preferably 5,000 to 100,000.
The content of the polymer of the component (A) in the liquid crystal alignment agent of the present invention can be appropriately changed depending on the thickness setting of the coating film to be formed, but from the viewpoint of forming a uniform and defect-free coating film, 1% by weight or more is preferable, and from the viewpoint of storage stability of the solution, 10% by weight or less is preferable, and 3 to 7% by weight is more preferable.

＜ (B) component ＞
The component (B) contained in the liquid crystal alignment agent of the present invention is a compound represented by the following formula (1).

(In the formula, Q ¹ and Q ² are one selected from the following formula (Q1-1) and a single bond, at least one of Q ¹ and Q ² is a formula (Q1-1), and q1 and q2 are independent of each other. Is 0 or 1, R ² and R ³ are each independently a group having an epoxy site and a hydrogen atom, and at least one of R ² and R ³ is a group having an epoxy site)

(In the formula (Q1-1), R ¹ is a hydrogen atom or a monovalent organic group. The monovalent organic group of R ¹ is preferably a methyl group, a phenyl group, a group having an epoxy site, or a thermally decomposable leaving group. .

The thermally decomposable leaving group refers to a substituent which is removed by heating and is substituted with a hydrogen atom. The thermally decomposable protecting group-based amine group may be a functional group substituted with a hydrogen atom by heat, and the structure is not particularly limited. From the standpoint of the storage stability of the liquid crystal alignment agent, the protective group D is preferably a protective group that does not detach at room temperature, and is preferably a protective group that detaches with heat of 80 ° C or higher, more preferably 100. Protective group for delamination by heat above ℃. From the viewpoint of the temperature at which the separation is performed, D is particularly preferably a tert-butoxycarbonyl group or a 9-fluorenylmethoxycarbonyl group.

Examples of the group having an epoxy site in the definitions of R ¹ , R ^2, and R ³ include glycidyl, 3,4-epoxycyclohexyl, and the like. In terms of ease of synthesis, glycidyl is used as Better.

Preferable examples of the compound represented by the (B) component include the following compounds (B-1) to (B-6).
(B-1): the above formula (1), q1 and q2 is 0, Q ¹ is (Q1-1), R ² and R ³ groups of the compound having an epoxy group is formed;
(B-2): In the above formula (1), q1 and q2 is 0, Q ¹ is (Q1-1), R ² is a hydrogen atom, R ³ compound having an epoxy group is formed;
(B-3): In the above formula (1), q1 and q2 is ^1, Q 1 is a single bond or (Q1-1), Q ² is (Q1-1), R ² and R ³ having an epoxy group Based compounds;
(B-4): In the above formula (1), q1 and q2 are 1, Q ¹ is a single bond or (Q1-1), Q ² is (Q1-1), R ² is a hydrogen atom, and R ³ is An epoxy-based compound;
(B-5): the above formula (1), q1 and q2 is 1, Q ¹ is (Q1-1), Q ² is a single bond, a compound having an epoxy group formed by R ² and R ³ ;
(B-6): In the above formula (1), q1 and q2 is ^1, Q 1 is (Q1-1), Q ² is a single bond, R ² is a hydrogen atom, R ³ is a group having an epoxy group and Into a compound.

Among the above, examples of preferred (B) components include compounds represented by any of the following formulae B-1-1 to B-5-1.

The compound of the component (B) is a cyclization reaction in which an epihalohydrin is reacted with a diamine represented by the following formula (0), and then the obtained addition reaction product is treated with an alkali. And available.

A well-known kind can also be used as a diamine represented by Formula (0).

In order to produce a compound in which both R ² and R ³ in the formula (1) are a group having an epoxy site, it is preferable to use an epoxy halopropane of 4 equivalents or more relative to the diamine represented by the formula (0). In order to use more than 8 equivalents, it can be treated with alkali afterwards. However, in order to produce a compound in which R ¹ is also a group having an epoxy site, the epoxy halopropane may be used in a large amount. When one of R ² and R ³ is to be a compound having an epoxy site and the other is a hydrogen atom, use 2 to 2.2 equivalents of epoxyhalopropane with respect to the diamine represented by formula (0), and then Then, it can be treated with alkali.

When there are too many (B) components, liquid crystal alignment will be affected, and when too few, the effect of this invention cannot fully be acquired. Therefore, the content of the component (B) in the liquid crystal alignment agent is preferably 0.1 to 20% by mass, and more preferably 1 to 10% by mass relative to the component (A) (100% by mass).

＜ Liquid crystal alignment agent ＞
The liquid crystal alignment agent used in the present invention has at least one selected from the group consisting of the polyfluorene imide precursor of the component (A) and the fluorinated polymer of the polyfluorene imide precursor. One type of polymer (hereinafter referred to as a specific structural polymer) and the form of a solution in which the compound of the component (B) is dissolved in an organic solvent. The molecular weight of the specific structural polymer is preferably a weight average molecular weight of 2,000 to 500,000, more preferably 5,000 to 300,000, and still more preferably 10,000 to 100,000. The number average molecular weight is preferably 1,000 to 250,000, more preferably 2,500 to 150,000, and even more preferably 5,000 to 50,000.

The concentration of the polymer of the liquid crystal alignment agent used in the present invention can be appropriately changed depending on the thickness setting of the coating film to be formed, but from the viewpoint of forming a uniform and defect-free coating film, it is 1% by weight. The above is preferred, and from the standpoint of storage stability of the solution, it is preferably 10% by weight or less.
The organic solvent (good solvent) contained in the liquid crystal alignment agent used in the present invention is not particularly limited as long as the polymer having a specific structure can be uniformly dissolved.
Examples include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl Sulfur, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, and the like.
Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and γ-butyrolactone are preferably used.
Furthermore, when the solubility of the polymer of the present invention in a solvent is high, it is preferable to use a solvent represented by the aforementioned formulas [D-1] to [D-3].
The good solvent in the liquid crystal alignment agent of the present invention is preferably 20 to 99% by mass of the entire solvent contained in the liquid crystal alignment agent. Among them, 20 to 90% by mass is preferable. It is more preferably 30 to 80% by mass.

In the liquid crystal alignment agent of the present invention, a solvent (also referred to as a poor solvent) for improving the coating property or surface smoothness of the liquid crystal alignment film when the liquid crystal alignment agent is applied can be used. The following are specific examples of poor solvents, but they are not limited to these examples.
Examples include ethanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, and 2-methyl alcohol. 1-butanol, iso-pentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2- Methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1- Hexanol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 1,2-ethylene glycol, 1,2-propanediol, 1,3-propanediol , 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 2-methyl-2,4- Pentylene glycol, 2-ethyl-1,3-hexanediol, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether , Ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol Alcohol dibutyl ether, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 3-ethoxybutyl acetate, 1-methylpentylacetic acid Esters, 2-ethylbutylethyl Esters, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethyl acetate, 2- (methoxymethoxy) ethanol, ethyl Glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, 2- (hexyloxy) ethanol, furfuryl alcohol, diethylene glycol, propylene glycol, propylene glycol monobutyl ether, 1- ( (Butoxyethoxy) propanol, propylene glycol monomethyl ether acetate, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, Ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, two Ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2- (2-ethoxyethoxy) ethyl acetate, diethylene glycol acetate, triethylene glycol Ethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether , Methyl pyruvate, ethyl pyruvate, 3-methoxy Methyl propionate, methyl ethyl 3-ethoxypropionate, ethyl ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxypropionic acid Propyl ester, butyl 3-methoxypropionate, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate or the aforementioned formula [D-1] ~ Solvent represented by Formula [D-3].
Among them, 1-hexanol, cyclohexanol, 1,2-ethylene glycol, 1,2-propylene glycol, propylene glycol monobutyl ether, ethylene glycol monobutyl ether, or dipropylene glycol dimethyl ether is preferred. .
These poor solvents are preferably 1 to 80% by mass of the entire solvent contained in the liquid crystal alignment agent. Among them, 10 to 80% by mass is preferable. It is more preferably 20 to 70% by mass.

In addition to the above, the liquid crystal alignment agent of the present invention may include: a polymer other than the polymer described in the present invention; a dielectric substance for the purpose of changing the electrical properties such as the dielectric constant and conductivity of the liquid crystal alignment film, A conductive substance; a silane coupling agent for the purpose of improving the adhesion between the liquid crystal alignment film and the substrate; a crosslinkable compound for the purpose of improving the hardness or the density of the film when the liquid crystal alignment film is made; When an amine precursor is fired, a sulfonium imidation accelerator for the purpose of sulfonation imidation by heating can be efficiently performed when the coating film is fired.

＜ Liquid crystal alignment film ＞
The liquid crystal alignment film of the present invention is a film obtained by applying the liquid crystal alignment agent to a substrate, and drying and firing the substrate. The substrate to which the liquid crystal alignment agent of the present invention is applied is not particularly limited as long as it is a substrate having high transparency, and a plastic substrate such as a glass substrate, a silicon nitride substrate, an acrylic substrate, or a polycarbonate substrate can be used. It is preferable to use a substrate formed with an ITO electrode for driving the liquid crystal from the viewpoint of simplification of the manufacturing process. In addition, since the reflective liquid crystal display element is only on one side of the substrate, an opaque material such as a silicon wafer can also be used. In this case, an electrode that can reflect light such as aluminum can also be used.

Examples of the method for applying the liquid crystal alignment agent of the present invention include a spin coating method, a printing method, and an inkjet method. The steps of drying and firing after applying the liquid crystal alignment agent of the present invention can be selected at any temperature and time. Generally, in order to sufficiently remove the organic solvent contained, it is dried at 50 ° C to 120 ° C for 1 minute to 10 minutes, and then fired at 150 ° C to 300 ° C for 5 minutes to 120 minutes. The thickness of the coating film after firing is not particularly limited. If the thickness is too thin, the reliability of the liquid crystal display element may be reduced. Therefore, the thickness is 5 to 300 nm, preferably 10 to 200 nm.

Examples of a method for subjecting the obtained liquid crystal alignment film to an alignment treatment include a rubbing method, a photo-alignment treatment method, and the like.
The friction treatment system can be performed using an existing friction device. Examples of the material of the friction cloth at this time include cotton, nylon, and rayon. As the conditions for the friction treatment, conditions such as a rotation speed of 300 to 2000 rpm, a feed speed of 5 to 100 mm / s, and a press-in amount of 0.1 to 1.0 mm are generally used. After that, it is washed with pure water or alcohol by ultrasonic waves to remove residues caused by friction.

As a specific example of the photo-alignment treatment method, a method of irradiating the surface of the coating film with radiation deviating in a certain direction, and performing a heat treatment at a temperature of 150 to 250 ° C. in accordance with various situations, thereby giving the liquid crystal alignment energy. As the radiation system, ultraviolet rays and visible rays having a wavelength of 100 to 800 nm can be used. Among them, ultraviolet rays having a wavelength of 100 to 400 nm are preferred, and those having a wavelength of 200 to 400 nm are particularly preferred. In addition, in order to improve the alignment of the liquid crystal, the coating film substrate may be irradiated with radiation while being heated at 50 to 250 ° C. The radiation dose is 1 ~ 10,000mJ /
cm ² is preferable, and 100 to 5,000 mJ / cm ² is particularly preferable. The liquid crystal alignment film produced in the above manner can stably align liquid crystal molecules in a certain direction.
The higher the extinction ratio of polarized ultraviolet rays, the higher anisotropy can be imparted, which is preferable. Specifically, the extinction ratio of linearly polarized ultraviolet rays is preferably 10: 1 or more, and more preferably 20: 1 or more.

As described above, the film irradiated with the polarized radiation may be subsequently subjected to a contact treatment with a solvent containing at least one selected from water and an organic solvent.
The solvent used in the contact treatment is not particularly limited as long as it is a solvent capable of dissolving a decomposed product generated by light irradiation. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, and 1-methoxy-2-propanol acetate. , Butylcellulose, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, and acetic acid ring Hexyl ester and so on. These solvents may be used in combination of two or more.
From the viewpoint of versatility or safety, at least one selected from the group consisting of water, 2-propanol, 1-methoxy-2-propanol, and ethyl lactate is more preferable. . Water, 2-propanol, and a mixed solvent of water and 2-propanol are particularly preferred.

In the present invention, the contact treatment of a film irradiated with polarized radiation and a solution containing an organic solvent can be performed by a treatment such as a dipping treatment, a spray treatment, or the like, in which the film and the solution can be brought into sufficient and sufficient contact. Among them, in a solution containing an organic solvent, a method of dipping the film for 10 seconds to 1 hour, and more preferably 1 to 30 minutes is more preferable. The contact treatment may be performed at normal temperature or under heating, and is preferably performed at 10 to 80 ° C, and more preferably at 20 to 50 ° C. In addition, if necessary, a means for increasing contact such as ultrasound can be applied.
After the above-mentioned contact treatment, in order to remove the organic solvent in the solution used, water washing with a low boiling point solvent such as water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, etc. Washing) or drying, or both.

Furthermore, for the film subjected to the above-mentioned contact treatment with a solvent, the solvent can be dried and the molecular chains in the film can be realigned for the purpose of heating the film at 150 ° C. or higher.
The heating temperature is preferably 150 to 300 ° C. Although the higher the temperature is, it will promote the re-alignment of the molecular chains. However, if the temperature is too high, the molecular chains may be decomposed. Therefore, the heating temperature is preferably 180 to 250 ° C, and particularly preferably 200 to 230 ° C.
When the heating time is shorter, the effect of realignment of the molecular chain may not be obtained. However, when the heating time is too long, the molecular chain may be decomposed. Therefore, it is better to use 10 seconds to 30 minutes. 1 ~ 10 minutes is better.

<Liquid crystal display element>
The liquid crystal display element of the present invention includes a liquid crystal alignment film obtained by the method for producing a liquid crystal alignment film.
The liquid crystal display element of the present invention is obtained by using the liquid crystal alignment agent of the present invention through the aforementioned method for manufacturing a liquid crystal alignment film to obtain a substrate with a liquid crystal alignment film. Display element.

As an example of a method for manufacturing a liquid crystal cell, a liquid crystal display element having a passive matrix structure will be described as an example. Each pixel portion constituting the screen display may be a liquid crystal display element having an active matrix structure provided with a switching element such as a TFT (Thin Film Transistor).
First, a transparent glass substrate is prepared. A common electrode is provided on one substrate and a segment electrode is provided on the other substrate. Such an electrode system can be, for example, an ITO electrode, and a desired screen display can be formed by patterning. Next, an insulating film is provided on each substrate so as to cover the common electrode and the segment electrode. The insulating film may be a film made of SiO ₂ -TiO ₂ formed by, for example, a sol-gel method.
Next, a liquid crystal alignment film of the present invention is formed on each substrate. Next, the substrates on one side and the substrates on the other side are overlapped so that the alignment films face each other, and the periphery is adhered with a sealing material. In order to control the substrate gap, a spacer is usually mixed into the sealing material. Moreover, it is also preferable to use a spacer for controlling the gap of the substrate in the in-plane portion where no sealing material is provided. A part of the sealing material is an opening provided with a liquid crystal that can be filled from the outside.
Next, a liquid crystal material is injected into a space surrounded by the two substrates and the sealing material by providing an opening portion in the sealing material. After that, the opening is sealed with an adhesive. For the injection, a vacuum injection method may be used, or a method using a capillary phenomenon in the atmosphere may be used. Next, set the polarizing plate. Specifically, a pair of polarizing plates are affixed on the surface opposite to the liquid crystal layer of two substrates. The liquid crystal display element of the present invention can be obtained through the above steps.

In the present invention, as the sealant, a resin having a reactive group such as an epoxy group, an acrylic fluorenyl group, a methacryl fluorenyl group, a hydroxyl group, an allyl group, an ethyl fluorenyl group, and the like, which is hardened by ultraviolet irradiation or heating, can be used . In particular, a hardened resin system using a reactive group having both an epoxy group and a (meth) acrylfluorenyl group is preferred.
The sealing agent of the present invention may be formulated with an inorganic filler for the purpose of improving adhesion and moisture resistance. The inorganic filler that can be used is not particularly limited, and specific examples include spherical silica, fused silica, crystalline silica, titanium oxide, titanium black, silicon carbide, silicon nitride, and boron nitride. , Calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, alumina, magnesia, zirconia, aluminum hydroxide, calcium silicate, aluminum silicate, lithium aluminum silicate, zirconium silicate, titanium Barium acid, nitrate fiber, carbon fiber, molybdenum disulfide, asbestos, etc., preferably spherical silica, fused silica, crystalline silica, titanium oxide, titanium black, silicon nitride, boron nitride, calcium carbonate , Barium sulfate, calcium sulfate, mica, talc, clay, aluminum oxide, aluminum hydroxide, calcium silicate, aluminum silicate. The aforementioned inorganic fillers may be used in combination of two or more.

[Example]

Hereinafter, the present invention will be specifically described with examples and the like, but the present invention is not limited to these examples. The meanings of the abbreviations of the compounds are as follows.

NMP: N-methyl-2-pyrrolidone
BCS: butyl cellosolve
THF: tetrahydrofuran
AIBN: 2,2'-Azobisisobutyronitrile

( ¹ H-NMR measurement)
Equipment: Varian NMR system 400NB (400MHz) (made by Varian) and JMTC-500 / 54 / SS (500MHz) (made by JEOL)
Measurement solvents: CDCl ₃ (deuterated chloroform), DMSO-d ₆ (deuterated dimethyl sulfene)
Reference materials: TMS (tetramethylsilane) (δ: 0.0 ppm, ¹ H) and CDCl ₃ (δ: 77.0 ppm, ¹³ C)

＜ Synthesis of Additive E1 ＞

To toluene (25 g) and pure water (2.5 g), epichlorohydrin (52.1 g) and 4,4'-diamino-N-methyldiphenylamine (10.0 g, 46.9 mmol) were added, and Stir at 80 ° C for 4 hours. After cooling to room temperature, tetrabutylammonium hydrogen sulfate (0.48 g) and a 48% aqueous sodium hydroxide solution (23.5 g) were added, and the mixture was stirred at 35 ° C for 3 hours, and then stirred at room temperature for 16 hours. Pure water (50 g) was added and a liquid separation operation was performed. The oil layer was washed with pure water (50 g), dehydrated with magnesium sulfate, and the filtrate was concentrated to obtain a crude product. After the crude product was dissolved with toluene (150 g), filtration was performed using a Hirsch funnel having a filter surface filled with silica gel (20 g). After the toluene (50 g) was washed away, the combined filtrate was concentrated to obtain a compound [E1] (yield: 13.2 g, yield: 64%, brown sticky substance).
1H-NMR (400MHz, DMSO-d6, δppm): 6.78-6.73 (m,
8H), 3.59 (t, 4H, J = 16 Hz), 3.38-3.26 (m, 4H), 3.13-3.04 (m, 7H), 2.75-2.71 (m, 4H), 2.58-2.55 (m, 4H) .

＜ Synthesis of Additive E2 ＞

Toluene (25g) and pure water (2.5g) were added epichlorohydrin (55.4g) and 4,4'-diaminodiphenyl ether (10.0g, 49.9mmol), and stirred at 80 ° C for 23 hour. After cooling to room temperature, tetrabutylammonium hydrogen sulfate (0.51 g) and a 48% aqueous sodium hydroxide solution (25.0 g) were added and stirred at 35 ° C for 5 hours. Pure water (50 g) was added and a liquid separation operation was performed. The oil layer was washed with pure water (50 g), dehydrated with magnesium sulfate, and the filtrate was concentrated to obtain a crude product. After dissolving the crude product with toluene (150 g), filtration was performed using a Tongshan funnel having a filter surface filled with silica gel (20 g). After the toluene (50 g) was washed away, the combined filtrate was concentrated to obtain a compound [E2] (yield: 15.3 g, yield: 72%, orange sticky substance).
1H-NMR (400MHz, DMSO-d6, δppm): 6.84-6.80 (m, 8H), 3.64 (t, 4H, J = 16 Hz), 3.40-3.28 (m, 4H), 3.14-3.08 (m, 4H ), 2.76-2.72 (m, 4H), 2.59-2.56 (m, 4H).

＜ viscosity ＞
In the synthesis example, the viscosity of the polymer solution was an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample volume of 1.1 mL, a tapered rotor TE-1 (1 ° 34 ', R24), and a temperature of 25 ° C. To measure.

(Synthesis example 1)
In a 5L four-necked flask equipped with a stirring device and a nitrogen introduction tube, 57.3 g of DA-1 (200 mmol) was weighed, 1147 g of NMP was added, and the nitrogen was stirred to dissolve it. While stirring the diamine solution under water cooling, 29.4 g of CA-1 (150 mmol) was added, 191 g of NMP was added, and the mixture was stirred at 23 ° C. for 1 hour under a nitrogen atmosphere. After that, 119.3 g of DA-2 (400 mmol) and 60.1 g of DA-3 (400 mmol) were weighed, and 1721 g of NMP was added, and dissolved while sending nitrogen while stirring. 158.8 g of CA-1 (810 mmol) was added to this diamine solution while stirring under water cooling, 765 g of NMP was added, and the mixture was stirred at 23 ° C. for 6 hours under a nitrogen environment to obtain a polyamic acid solution (viscosity 180 mPa・ S).

(Synthesis example 2)
MA1 (5.3g) and MA2 (19.6g) were dissolved in THF (102.6g), and after degassing by a diaphragm pump, AIBN (0.39g) was added and degassed again. Then, it was made to react at 60 degreeC for 8 hours, and the methacrylate polymer solution was obtained. This polymer solution was dropped into methanol (600 ml), and the obtained precipitate was filtered. This deposit was wash | cleaned with methanol, and it dried under reduced pressure in the 40 degreeC oven, and obtained methacrylate polymer powder MP1.

[Example 1] and [Comparative Examples 1, 2]
So that the composition of the obtained liquid crystal alignment agent became the composition shown in Table 1, while stirring the polyamic acid solution obtained in Synthesis Example 1, a solvent and an additive were added, and the mixture was further stirred at room temperature for 2 hours. Thus, a liquid crystal alignment agent is obtained.

* 1: The content (parts by weight) of each polymer relative to 100 parts by weight of the total polymer in the liquid crystal alignment agent.
* 2: The content (parts by weight) of each additive relative to 100 parts by weight of the total polymer in the liquid crystal alignment agent.
* 3: The content (parts by weight) of each solvent relative to 100 parts by mass of the liquid crystal alignment agent.

[Example 2] and [Comparative Examples 3 and 4]
NMP was added to the methacrylate powder obtained in Synthesis Example 2, and the mixture was stirred for 30 minutes to obtain a methacrylate polymer solution. The liquid crystal alignment agent was obtained so that the composition of the obtained liquid crystal aligning agent might become a composition shown in Table 2, and a solvent and an additive were added, and it stirred at room temperature for 2 hours.

* 1: The content (parts by weight) of each polymer relative to 100 parts by weight of the total polymer in the liquid crystal alignment agent.
* 2: The content (parts by weight) of each additive relative to 100 parts by weight of the total polymer in the liquid crystal alignment agent.
* 3: The content (parts by weight) of each solvent relative to 100 parts by mass of the liquid crystal alignment agent.

The following is a method for fabricating a liquid crystal cell for evaluating the relaxation characteristics, flicker characteristics, and liquid crystal alignment of accumulated charges.
A liquid crystal cell having a configuration of a liquid crystal display element of the FFS method was produced. First, a substrate with electrodes is prepared. The substrate is a glass substrate having a length of 30 mm, a width of 35 mm, and a thickness of 0.7 mm. On the substrate, an IZO electrode constituting a counter electrode is formed on the entire surface as the first layer. On the counter electrode of the first layer, as a second layer, a SiN (silicon nitride) film formed by a CVD method is formed. The SiN film of the second layer has a film thickness of 500 nm, and functions as an interlayer insulating film. On the SiN film of the second layer, as the third layer, comb-shaped pixel electrodes formed by patterning the IZO film are arranged to form two pixels of the first pixel and the second pixel. The size of each pixel is 10mm in length and about 5mm in width. At this time, the counter electrode of the first layer and the pixel electrode of the third layer are electrically insulated by the action of the SiN film of the second layer.

The pixel electrode of the third layer has a comb-tooth shape formed by arranging a plurality of “く” -shaped electrode elements having a curved central portion. The width in the short-side direction of each electrode element was 3 μm, and the interval between the electrode elements was 6 μm. The pixel electrode forming each pixel is formed by arranging a plurality of electrode elements with a curved “く” shape at the central portion. Therefore, the shape of each pixel is not a rectangular shape, but has a similar bold shape with the central portion curved like the electrode element. The shape of the "く 字" of the character. In addition, each pixel is divided up and down with its central curved portion as a boundary, and each pixel has a first region on the upper side and a second region on the lower side.
When the first region and the second region of each pixel are compared, the formation direction of the electrode elements constituting such pixel electrodes will be different. That is, when the rubbing direction of the liquid crystal alignment film described later is used as a reference, the electrode element of the pixel electrode is formed at an angle (clockwise) of + 10 ° in the first region of the pixel, and The electrode elements of the pixel electrode are formed at an angle (clockwise) of -10 °. That is, in the first region and the second region of each pixel, the directions of the rotation motion (in-plane turning) of the liquid crystal in the substrate plane induced by the voltage application between the pixel electrode and the counter electrode are opposite to each other. Direction way to construct.

Next, the liquid crystal alignment agents obtained in the examples and comparative examples were filtered using a filter having a pore size of 1.0 μm, and then applied by a spin coater to a substrate on which the electrodes were prepared. After drying on a hot plate at 80 ° C. for 2 minutes, firing was performed in a hot air circulation oven at 230 ° C. for 20 minutes to obtain a polyimide film having a film thickness of 60 nm. This polyimide film was rubbed with a cloth (roller diameter: 120 mm, roller rotation number: 500 rpm, moving speed: 30 mm / sec, press-in length: 0.3 mm, rubbing direction: relative to the third-layer IZO comb-teeth electrode After it was tilted in a direction of 10 °), it was washed with ultrasonic wave in pure water for 1 minute, and water droplets were removed by blast. Then, it dried at 80 degreeC for 15 minutes, and obtained the board | substrate with a liquid crystal alignment film. In addition, as a counter substrate, a polyimide film was also formed on the glass substrate having a columnar spacer having a height of 4 μm on the inside in the same manner as described above, according to the same process as above, A substrate with a liquid crystal alignment film subjected to an alignment treatment was obtained. The two substrates with a liquid crystal alignment film are used as a group. A sealant is printed on the substrate with a liquid crystal injection port left. The liquid crystal alignment film is face to face and the friction direction is antiparallel. 1 substrate. After that, the sealant was hardened to produce an empty cell with a cell spacing of 4 μm. Liquid crystal MLC-3019 (manufactured by Merck) was injected into the empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an FFS-type liquid crystal cell. After that, the obtained liquid crystal cell was heated at 120 ° C for 1 hour, and left at 23 ° C for a while, and then used to evaluate the alignment of the liquid crystal.

＜ Reduction characteristics of accumulated charge ＞
The above-mentioned liquid crystal cell is disposed between two polarizing plates having a polarizing axis arranged vertically, and the LED backlight is irradiated from below the two polarizing plates while the pixel electrode and the opposite electrode are short-circuited and at the same potential. The angle of the liquid crystal cell is adjusted so that the brightness of the transmitted light of the LED backlight measured above the two polarizing plates is minimized.
Next, while applying a rectangular wave having a frequency of 30 Hz to the liquid crystal cell, the VT characteristic (voltage-transmittance characteristic) at a temperature of 23 ° C. was measured to calculate an AC voltage at a relative transmittance of 23%. Since this AC voltage corresponds to a region where the brightness of the voltage changes greatly, it is convenient to evaluate the accumulated charge by the brightness.
Next, at a temperature of 23 ° C. and an AC voltage with a relative transmittance of 23%, a rectangular wave having a frequency of 30 Hz was applied for 5 minutes, and a DC voltage of +1.0 V was superimposed and driven for 30 minutes. After that, the DC voltage was cut off, and again under the AC voltage with a relative transmittance of 23%, only a rectangular wave having a frequency of 30 Hz was applied for 15 minutes.
The faster the accumulated charge is relaxed, the faster the charge accumulation of the liquid crystal cell when the DC voltage is superimposed. Therefore, the relaxation characteristic of the accumulated charge is reduced from the relative transmittance shortly after the superimposed DC voltage to 2% or more. The time needed to evaluate. That is, when the relative transmittance is reduced to 2% or more within 30 minutes, it is defined as "good"; when the relative decrease does not decrease to more than 2% even after 30 minutes, it is defined as " Bad "to evaluate.

＜ Evaluation of liquid crystal alignment ＞
Using this liquid crystal cell, an AC voltage at a frequency of 30 Hz and 9 VPP was applied for 190 hours in a constant temperature environment of 60 ° C. After that, in a state where a short circuit occurs between the pixel electrode and the counter electrode of the liquid crystal cell, it is left to stand at room temperature for one day.
After being placed, the liquid crystal cell is placed between two polarizing plates with the polarizing axis arranged vertically, and the backlight is turned on under no voltage application, and the liquid crystal cell is adjusted so that the brightness of transmitted light is minimized. Configuration angle. When the liquid crystal cell is rotated from the second region of the first pixel to the darkest angle and rotated to the first region as the darkest angle, the rotation angle is calculated by the angle Δ. Similarly, the second pixel is compared with the second region to calculate the same angle Δ. The average value of the angle Δ values of the first pixel and the second pixel is calculated as the angle Δ of the liquid crystal cell. If the value of the angle Δ of the liquid crystal cell is less than 0.2 degrees, it is defined as "good"; if the value of the angle Δ is 0.2 degrees or more, it is defined as "bad" for evaluation.

＜ Evaluation of voltage holding ratio (VHR) ＞
A voltage of 1 V was applied to the obtained liquid crystal cell at a temperature of 60 ° C. for 60 μs, and the voltage after 50 ms was measured to calculate how much the voltage can be maintained as the voltage retention rate. The measurement of the voltage holding ratio was performed using a voltage holding ratio measuring device VHR-1 manufactured by TOYO Corporation.

<Evaluation of optical characteristics (transparency)>
A quartz substrate having a length of 40 mm, a width of 40 mm, and a thickness of 1.0 mm was prepared. Next, the liquid crystal alignment agent was filtered by a 1.0 μm filter, and then spin-coated on the quartz substrate. Next, after drying on a hot plate at 80 ° C. for 2 minutes and firing at 230 ° C. for 20 minutes, a polyimide film having a film thickness of 100 nm was obtained on each substrate.
The evaluation of the transparency is performed by measuring the transmittance of the substrate obtained by the method described above. Specifically, the measurement device uses UV-3600 (manufactured by Shimadzu Corporation) and measures transmittance under conditions of a temperature of 25 ° C. and a scanning wavelength of 300 to 800 nm. At this time, a reference (reference example) was performed using an uncoated quartz substrate. The evaluation system calculates an average transmittance at a wavelength of 400 to 800 nm. The higher the transmittance, the better the transparency is considered.

＜ Evaluation results ＞
For the liquid crystal display elements using the liquid crystal alignment agents of Examples 1 to 4 and Comparative Examples 1 to 3 described above, the evaluation of the afterimage disappearance time, the evaluation of the stability of the liquid crystal alignment, and the evaluation of the transparency were performed. The results are shown in Table 3.

* 1: The content (parts by weight) of each polymer relative to 100 parts by weight of the total polymer in the liquid crystal alignment agent.
* 2: The content (parts by weight) of each additive relative to 100 parts by weight of the total polymer in the liquid crystal alignment agent.

As shown in Table 3, it can be seen that the liquid crystal display element system using the liquid crystal alignment agent of Example 1 has an excellent voltage retention rate, rapid relaxation of accumulated charges, and good liquid crystal alignment or transparency.

[Industrial availability]

The liquid crystal alignment agent system of the present invention is widely used in a liquid crystal display element having a longitudinal electric field method such as a TN method or a VA method, and particularly a transverse electric field method such as an IPS method or an FFS method.
The entire contents of the specification, scope of patent application, and abstract of Japanese Patent Application No. 2018-51092 filed for a patent application on March 19, 2018 are incorporated herein for the disclosure of the specification of the present invention.

Claims (12)

A liquid crystal alignment agent, comprising the following components (A), (B) and an organic solvent, (A) component: selected from the group consisting of a polyimide precursor and a polyimide precursor of the polyimide A polymer and a polymer of at least one of the group consisting of a photosensitive side-chain acrylic polymer exhibiting liquid crystallinity in a temperature range of 100 to 300 ° C; (B) component: the following formula (1) Represented compound, (In formula (1), Q ¹ and Q ² are one selected from the following formula (Q1-1) and a single bond, and at least one of Q ¹ and Q ² is formula (Q1-1), q1 and q2 is independently 0 or 1, R ² and R ³ are each independently a group having an epoxy site or a hydrogen atom, and at least one of R ² and R ³ is a group having an epoxy site) (In formula (1), R ¹ is a hydrogen atom or a monovalent organic group). The liquid crystal alignment agent according to claim 1, wherein the polyimide precursor of the component (A) has a structural unit represented by the following formula (A1), (In formula (A1), X ₁ is a tetravalent organic group, Y ₁ is a divalent organic group, R ₁ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and A ₁ and A ₂ are each independently a hydrogen atom. An alkyl group having 1 to 10 carbon atoms having a substituent, an alkenyl group having 2 to 10 carbon atoms having a substituent, or an alkynyl group having 2 to 10 carbon atoms having a substituent). The liquid crystal alignment agent according to claim 2, wherein in the formula (A1), Y ₁ is at least _one selected from the structure represented by the following formula (5) and the structure represented by the formula (6), (In formula (5), R ₁₂ is a single bond or a divalent organic group having 1 to 30 carbon atoms, R ₁₃ is a hydrogen atom, a halogen atom, or a monovalent organic group having 1 to 30 carbon atoms, and a is 1 to 4 Integer, when a is 2 or more, two or more R ₁₂ and two or more R ₁₂ R ₁₃ may be the same or different; in formula (6), R ₁₄ is a single bond, -O-, -S- , -NR _15- , amine bond, ester bond, urea bond, or divalent organic group having 1 to 40 carbon atoms). The liquid crystal alignment agent according to claim 1, wherein the photosensitive side-chain acrylic polymer exhibiting liquid crystallinity in the temperature range of 100 to 300 ° C. of the component (A) has the following formulae (i) to (v) ) Of at least one type of side chain structure, (In the formulae (i) to (v), Ar ₁ is a divalent substituent obtained by removing two hydrogen atoms from a benzene ring, a naphthalene ring, a pyrrole ring, a furan ring, a thiophene ring, or a pyridine ring, and Ar ₂ and Ar _{3 is} independently a divalent substituent obtained by removing two hydrogen atoms from a benzene ring, a naphthalene ring, a pyrrole ring, a furan ring, a thiophene ring, or a pyridine ring. One of q1 and q2 is 1, and the other is 0. Ar ₄ and Ar ₅ each independently represent a divalent substituent obtained by removing two hydrogen atoms from a benzene ring, a naphthalene ring, a pyrrole ring, a furan ring, a thiophene ring, or a pyridine ring, and Y ₁ and Y ₂ are each independently -CH = CH-, -CH = N-, -N = CH-, or -C≡C-, S ₁ , S ₂ and S ₃ each independently represent a single bond, a linear or branched carbon having 1 to 18 carbon atoms Divalent alkylene groups, cycloalkylene groups with 5 to 8 carbon atoms, phenylene groups, biphenylene groups, or divalent substituents composed of these 2 to 10 combinations. However, the aforementioned divalent substituents may also be used. R is a structure in which a plurality of divalent substituents are connected through a single bond, an ether bond, an ester bond, a amine bond, a urea bond, a urethane bond, an amine bond, and a carbonyl bond, respectively. R ₁₁ is a hydrogen atom, a hydroxyl group, a mercapto group, amino group, having 1 to 10 carbon atoms Group, alkoxy having 1 to 10 carbon atoms or an alkyl group having 1 to 8 carbon atoms, dialkylamino of 2 to 16). The liquid crystal alignment agent according to any one of claims 1 to 4, wherein the compound represented by the component (B) is at least one selected from the following formulae (B-1) to (B-6), (B-1): in the formula (1), q1 and q2 is 0, Q ¹ is (Q1-1), a compound having an epoxy group formed by R ² and R ^3; (B-2) : A compound in which q1 and q2 are 0, Q ¹ is (Q1-1), R ² is a hydrogen atom, and R ³ is a group having an epoxy group in the formula (1); (B-3): formula (1), q1 and q2 ^1, Q 1 is a single bond or (Q1-1), Q ² is (Q1-1), R ² and R ³ is a group of compounds having an epoxy group is formed; (B-4): in the formula (1), q1 and q2 is ^1, Q 1 is a single bond or (Q1-1), Q ² is (Q1-1), R ² is a hydrogen atom, R ³ is having compounds formed by epoxy group; (B-5): the formula (1), q1 and q2 is ^1, Q 1 is (Q1-1), Q ² is a single bond, R ² and R ³ group formed by compounds having an epoxy group; (B-6): the formula (1), q1 and q2 is ^1, Q 1 is (Q1-1), Q ² is a single bond, R ² is a hydrogen atom R ³ is a compound having an epoxy group. The liquid crystal alignment agent according to any one of claims 1 to 5, wherein the compound of the component (B) is at least one selected from the following formulae Q1-1-1 to Q1-1-7, . The liquid crystal alignment agent according to any one of claims 1 to 6, wherein the organic solvent is N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2- Pyrrolidone, N-ethyl-2-pyrrolidone, dimethylarsine, γ-butyrolactone, 1,3-dimethyl-imidazolidone, methyl ethyl ketone, cyclohexanone, cyclopentyl Ketone or 4-hydroxy-4-methyl-2-pentanone. The liquid crystal alignment agent according to claim 7, wherein the organic solvent further includes a solvent for improving a coating property or a surface smoothness of the liquid crystal alignment film. The liquid crystal alignment agent according to any one of claims 1 to 8, wherein the liquid crystal alignment agent contains 1 to 10% by mass of a polymer containing the component (A). The liquid crystal alignment agent according to claim 9, wherein the liquid crystal alignment agent contains the component (B) in an amount of 0.1 to 20% by mass based on the component (A). A liquid crystal alignment film obtained from the liquid crystal alignment agent according to any one of claims 1 to 10. A liquid crystal display element including the liquid crystal alignment film of claim 11.