TW201940677A - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display element - Google Patents

Abstract

Provided are: a liquid crystal aligning agent which enables the achievement of a liquid crystal alignment film that has excellent voltage holding ratio and exhibits rapid reduction of accumulated charges, while having good liquid crystal aligning properties and transparency; a liquid crystal alignment film; and a liquid crystal display element. A liquid crystal aligning agent which is characterized by containing an organic solvent and the component (A) and the component (B) described below. Component (A): At least one polymer selected from the group consisting of polyimide precursors having a structure of formula (2) and imidized polymers of the polyimide precursors. (In the formula, R5 represents a single bond or the like; R6 represents a structure -(CH2)n-; n represents a number of 2-20; and R7 represents a single bond or the like.) Component (B): A compound represented by formula (1). (In the formula, each of Q1 and Q2 represents (Q1-1), (Q1-2) or the like.) (In the formulae, each of q1 and q2 represents or 1; R1 represents a hydrogen atom or the like; each of L1 and L2 represents a hydrogen atom or the like; and each of S1 and S2 represents a group represented by formula (S).) (In the formula, R2 represents a hydrogen atom or the like; L represents an alkylene group having 2-20 carbon atoms, or the like; each of R3 and R4 represents an alkyl group having 1-4 carbon atoms, or the like; q represents a number of 1-3; and * represents the bonding position to formula (1).).

Description

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

The present 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 personal computers, mobile phones, smartphones, and televisions. The liquid crystal display element includes, for example, a liquid crystal layer held 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 regulates the alignment of liquid crystal molecules in the liquid crystal layer, and a switching pixel. Thin film transistors (TFTs), etc., for the electrical signals supplied by the electrodes. As a driving method of the 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. An electrode is formed only on one side of the substrate, and a horizontal electric field method in which an electric field is applied in a direction parallel to the substrate is compared with a conventional vertical electric field method in which a liquid crystal is driven by applying a voltage to an electrode formed on a substrate above and below. Characteristics, and high-quality liquid crystal display elements.

Although the liquid crystal lattice of the transverse electric field method has excellent viewing angle characteristics, since there are few electrode parts formed in the substrate, and the voltage retention rate is low, there is insufficient voltage to the liquid crystal, and the display contrast is reduced. In addition, when the stability of the liquid crystal alignment is small, when the liquid crystal is driven for a long period of time, the liquid crystal cannot return to the initial state, and the stability of the liquid crystal alignment is important because it becomes a cause of reduced contrast or afterimage. Furthermore, static electricity is easily accumulated in the liquid crystal lattice, and even if the positive and negative asymmetric voltages generated by the driving are applied, electric charges are accumulated in the liquid crystal lattice, and these accumulated electric charges are displayed as disorder or afterimage pairs of liquid crystal alignment. Bring impact, significantly reduce the display quality of liquid crystal elements.

When a liquid crystal display element using such a transverse electric field method is used, as a liquid crystal alignment agent that has excellent voltage retention and reduces charge accumulation, Patent Document 1 discloses a liquid crystal alignment agent containing a specific diamine and an aliphatic tetracarboxylic acid derivative. . In addition, as a method for shortening the time until afterimages disappear, it has been proposed to use an alignment film having a low volume resistivity such as that of Patent Document 2 or to use a volume resistivity such as that of Patent Document 3 even when the backlight of a liquid crystal display element is used. Method of difficult to change alignment film. However, with the increase in the performance of liquid crystal display elements, the characteristics required for liquid crystal alignment films have become stricter, and it is difficult for these 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

[Questions to be Solved by the Invention]

The present invention is to provide a liquid crystal alignment film with excellent voltage holding ratio, rapid relaxation of accumulated charge, and good liquid crystal alignment or transparency, and particularly has excellent characteristics of display elements such as IPS and FFS lateral electric field systems. Liquid crystal alignment agents, liquid crystal alignment films, and liquid crystal display elements are the subject.

[Means to solve the problem]

As a result of intensive studies by the present inventors to solve the above-mentioned problems, the present invention has finally been completed.
That is, the present invention is based on a liquid crystal alignment agent containing the following (A) component, (B) component, and an organic solvent as features.
(A) Component: Polymerization of at least one polyimide precursor having a structure of the following formula (2) and at least one selected from the group consisting of a polyimide polymer of the polyimide precursor Thing

However, in formula (2), R ⁵ is a single bond or a divalent organic group, R ⁶ is a structure represented by-(CH ₂ ) _n- , n is an integer of 2 to 20, and any -CH ₂ -may not be separately Adjacent conditions are substituted with a bond selected from ether, ester, and amidine. R ⁷ is a single bond or a divalent organic group. Any hydrogen atom on the benzene ring may be substituted by a monovalent organic group.
(B) component: a compound represented by the following formula (1)

However, in Formula (1), Q ¹ and Q ² are each independently selected from one of the following (Q1-1), (Q1-2), and single bond, but in Formula (1), Q ¹ and Q ² of a medium is at least one selected from (Q1-1) and (Q1-2); R ¹ is a hydrogen atom or a monovalent organic group;

q1 and q2 are independently 0 or 1,
L ¹ and L ² are hydrogen atoms. However, when Q ¹ is (Q1-1), L ¹ and L ² may form a single bond together;
S ¹ and S ² are each independently a base represented by the following formula (S);

In the formula, R ² represents a hydrogen atom or an alkyl group, L represents an alkylene group having 2 to 20 carbon atoms, and R ³ and R ⁴ are each independently an alkyl group having 1 to 4 carbon atoms or an alkenyl group having 2 to 4 carbon atoms or An alkynyl group having 2 to 4 carbon atoms, and q represents a natural number of 1 to 3. * Indicates a bond of the formula (1).

[Inventive effect]

By using the liquid crystal alignment agent of the present invention, it is possible to provide a liquid crystal alignment film capable of obtaining a liquid crystal alignment film having excellent voltage retention, rapid relaxation of charge accumulation, and good liquid crystal alignment or transparency, especially in the IPS method and the FFS method. A liquid crystal display element having excellent characteristics such as a lateral electric field type display element. It is not clear why the above-mentioned problems can be solved by the present invention, but it is probably considered as follows. In the liquid crystal alignment agent of the present invention, the structure of the compound represented by the formula (1), which is the component (B), which is contained together with the component (A), has a conjugated structure, for example, in a liquid crystal alignment film. The movement of electric charge can promote the relaxation of the accumulated electric charge.

＜ (A) component ＞
The component (A) contained in the liquid crystal alignment agent of the present invention is selected from a polyimide precursor having a structure represented by the following formula (2) and a polyimide polymer of the polyimide precursor. At least one polymer in the group (hereinafter, also referred to as a specific polymer (A)).

However, the definitions of the symbols in the formula (2) are as described above.
R ⁵ is a single bond or a divalent organic group, R ⁶ is a structure represented by-(CH ₂ ) _n- , n is an integer of 2 to 20, and any of -CH ₂ -may be substituted with non-adjacent conditions to be selected from ethers, esters and amines of the acyl bond, R ⁷ is a single bond or a divalent organic radical, any of the hydrogen atom of the benzene ring may be substituted with a monovalent organic group.
Examples of the divalent organic group constituting R ⁵ include a phenyl group (hereinafter referred to as -Ph-), -Ph- (CH ₂ ) _m- (m is an integer from 1 to 10), -Ph-O-, -Ph-OC (= O)-, -Ph-C (= O) -O-, -Ph-C = CO-, etc. R ^{6 is} preferably a single bond or a phenyl group.
Examples of the divalent organic group constituting R ⁷ include-(Ph) _k- (k is an integer of 1 to 3), -Ph- (CH ₂ ) _m -Ph- (m is an integer of 1 to 10) , -Ph- (CH ₂ ) _l -Ph- (CH ₂ ) _m -Ph- (l and m are each independently an integer of 1-10), -Ph-O-Ph-, -Ph-OC (= O) -Ph-, -Ph-C (= O) -O-Ph-, -Ph-C = CO-Ph-, etc. R ^{7 is} preferably phenyl or -Ph- (CH ₂ ) _m -Ph- (m is an integer of 1 to 10).
It is preferable that n in Formula (2) is an integer of 1-10. The monovalent organic group of the hydrogen atom of the benzene ring is preferably a group selected from a fluorine atom and a methyl group.

As the structure represented by Formula (2), although the following are specifically mentioned, it is not limited to these. In the following formula, Me represents a methyl group.

The specific polymer (A) in the present invention is preferably a polymer obtained by using a diamine having a structure represented by the formula (2). Specific examples of the specific polymer (A) include polyamic acid, polyamidate, and polyimide. From the viewpoint of being a liquid crystal alignment agent, the specific polymer (A) is preferably a polymer selected from the group consisting of a polyimide precursor comprising a structural unit represented by the following formula (3) and a polyimide compound thereof. At least one of sulfonium imines.

However, in formula (3), X ³ is a tetravalent organic group derived from a tetracarboxylic acid derivative. Specifically, it is preferably at least one selected from the group consisting of structures represented by the following formulae (X1-1) to (X1-45).

In formula (X1-1), R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ 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, or a benzene group. base. From the viewpoint of liquid crystal alignment, R ⁸ , R ⁹ , R ¹⁰ and R ^{11 are} preferably a hydrogen atom, a halogen atom, a methyl group or an ethyl group, and more preferably a hydrogen atom or a methyl group.

Among these, X ³ is (X1-10), (X1-11), or (X1-29), and (X1-10) or ( X1-11).

In formula (3), Y ₃ is a divalent organic group derived from a diamine containing a structure of formula (2), and from the viewpoint of alignment, in formula (2), R ^{7 is} preferably derived from a single bond Or a divalent organic group of a benzene ring diamine. R ¹³ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and is particularly preferably a hydrogen atom or a methyl group from the viewpoint of easy progress of imidization by heating.

The ratio of the specific polymer (A) of the present invention to the structural unit selected from at least one structural unit selected from the structural unit represented by the above formula (3) and the structural unit obtained by imidating it, relative to the specific polymer The total structural unit in (A) preferably contains 20 to 100 mol%, and from the viewpoint of both liquid crystal alignment and reliability, more preferably contains 30 to 70 mol%, and even more preferably contains 50 to 70 mole%.

The specific polymer (A) of the present invention may further have a structural unit represented by the following formula (4) in addition to the structural unit represented by the above formula (3) and / or a structural unit in which the fluorene is imidized.

However, in formula (4), R ^{14 has the} same definition as R ^{13 in} formula (3). X ₄ is a tetravalent organic group derived from a tetracarboxylic acid derivative, and its structure is not particularly limited. Specific examples include the structures of the formulae (X1-1) to (X-45).

In the formula (4), Y ₄ is a divalent organic group derived from a diamine, and its structure is not particularly limited. Specific examples of Y ₄ include structures of the following formulae (Y-1) to (Y-140).

When the specific polymer (A) contains polyimide of fluorene imidized polyfluorene imide precursor, the ratio of the structural unit of fluorene imine (also referred to as fluorene imine ratio) can be adapted to the liquid crystal alignment agent. The characteristics can be adjusted arbitrarily. From the viewpoint of the voltage holding ratio, although the fluorene imidization ratio of the specific polymer (A) is high, it is preferable that the fluorene imidization ratio is 40 when the solubility is excessively high because the solubility is deteriorated. ~ 95%, more preferably 55 ~ 90%.

The polyfluorene imide precursor system used in the present invention is obtained by a reaction between a diamine component and a tetracarboxylic acid derivative, and examples thereof include polyamic acid or polyamic acid esters.

＜ Polyimide precursor (Polyamido acid) ＞
The polyamidoacid precursor of the polyamidoimide precursor used in the present invention is produced by the following method. Specifically, by reacting tetracarboxylic dianhydride and diamine in an organic solvent at a temperature of -20 to 150 ° C, preferably 0 to 50 ° C, the reaction can be performed for 30 minutes to 24 hours, preferably 1 to 12 hours to make.

The reaction of the diamine component and the tetracarboxylic acid component is usually performed in an organic solvent. The organic solvent used at this time is not particularly limited as long as it dissolves the produced polyimide precursor. Although specific examples of the organic solvent used in the reaction are listed below, they are not limited to these examples. Examples include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone, N, N-dimethylformamide, N, N-dimethylacetamide, Methyl sulfene or 1,3-dimethyl-tetrahydroimidazolone.
When the polyimide precursor has high solubility, 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 Represents an alkyl group having 1 to 4 carbon atoms.

These organic solvents can 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 does not precipitate the generated polyfluorene imide precursor. In addition, since the water in the organic solvent hinders the polymerization reaction and becomes the cause of the hydrolyzed polyfluorene imide precursor, it is preferable to use a dehydrated organic solvent.

The concentration of the polyamic acid polymer in the reaction system is preferably from 1 to 30% by mass, and more preferably 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. .

The polyamic acid obtained as described above can be recovered by injecting a poor solvent while sufficiently stirring the reaction solution to precipitate a polymer. Furthermore, after carrying out precipitation several times, washing with a poor solvent, and drying at room temperature or heating, a purified polyamic acid powder can be obtained. The poor solvent is not particularly limited, but examples thereof include water, methanol, ethanol, hexane, butyl cellosolve, acetone, and toluene.

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

(1) When produced from polyamic acid, polyamic acid esters can be produced by esterifying polyamino acids. Specifically, the reaction can be performed at a temperature of -20 to 150 ° C, preferably 0 to 50 ° C for 30 minutes to 24 hours, preferably 1 in the presence of a polyamic acid and an esterifying agent in an organic solvent. ~ 4 hours reaction to make.

The esterifying agent is preferably one which can be easily removed by purification. Examples include N, N-dimethylformamide dimethyl acetal, 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-tolyl Triazene, 1-ethyl-3-p-tolyltriazene, 1-propyl-3-p-tolyltriazene, 4- (4,6-dimethoxy-1,3, 5-triazinehydrazone 2-yl) -4-methylmorpholinium chloride and the like. The amount of the esterifying agent to be added is 1 mol, and preferably 2 to 6 mol equivalents relative to the repeating unit of the polyamic acid.

Examples of the organic solvent include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or γ-butyrolactone, N, N-dimethylformamide, and N, N-dimethylethyl Amidine, dimethylsulfinium, or 1,3-dimethyl-tetrahydroimidazolone. In addition, when the solvent solubility of the polyfluorene imide precursor is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or the aforementioned formula [D- 1] to an organic solvent represented by the formula [D-3].

These organic solvents can be used alone or in combination. Furthermore, even if it is a solvent which cannot dissolve the polyfluorene imide precursor, it can be used by mixing with the said solvent in the range which does not precipitate the generated polyfluorene imide precursor. In addition, since the water in the organic solvent hinders the polymerization reaction and becomes the cause of the hydrolyzed polyfluorene imide precursor, it is preferable to use a dehydrated organic solvent.
From the viewpoint of the solubility of the polymer, the solvent used in the above reaction is preferably N, N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone. Or mix two 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 the polymer and it is easy to obtain a high molecular weight body.

(2) Polyamines can be produced from tetracarboxylic acid diester dichloride and diamine when produced by the reaction of tetracarboxylic acid diester dichloride and diamine. Specifically, the tetracarboxylic acid diester dichloride and diamine can be carried out 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, although pyridine, triethylamine, 4-dimethylaminopyridine, and the like can be used, since the reaction proceeds slowly, pyridine is preferred. The amount of the alkali added is preferably from 2 to 4 times moles relative to the tetracarboxylic acid diester dichloride in terms of an amount that can be easily removed and a high molecular weight body is easily obtained.

As said organic solvent, from the solubility of a monomer and a polymer, N-methyl-2-pyrrolidone or γ-butyrolactone is preferable, and these can be used by mixing 1 type or 2 or more types.
The polymer concentration at the time of production is preferably from 1 to 30% by mass, and more preferably from 5 to 20% by mass, from the viewpoint that it is difficult to cause precipitation of a polymer and a high-molecular-weight body is easily obtained. In addition, in order to prevent the hydrolysis of the tetracarboxylic acid diester dichloride, the organic solvent used in the production of polyamidate is preferably dehydrated as much as possible, and preferably in a nitrogen environment to prevent outside air from being mixed.

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

As the aforementioned condensing agent, 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'-tetramethylurenium tetrafluoroborate, O- (benzotriazol-1-yl) -N, N, N ', N'-tetramethylurenium hexafluorophosphate, (2,3 -Dihydro-2-thio (Thioxo) -3-benzoxazolyl) phosphonic acid diphenyl and the like. The addition amount of the condensing agent is preferably 2 to 3 times moles relative to the tetracarboxylic acid diester.

Examples of the base include tertiary amines such as pyridine and triethylamine. The addition amount of the alkali is preferably from 2 to 4 times moles relative to the diamine component in terms of an amount that can be easily removed and a high molecular weight body can be easily obtained.
In the above reaction, the reaction is efficiently performed by adding a Lewis acid as an additive. The Lewis acid is preferably a lithium halide such as lithium chloride or lithium bromide. The addition amount of the Lewis acid is preferably 0 to 1.0 times mole with respect to the diamine component.

Among the three methods for producing polyamic acid esters, in order to obtain high molecular weight polyamic acid esters, it is particularly preferable to use the above-mentioned method (1) or (2).
The solution of the obtained polyamic acid ester is carried out as described above, and a polymer can be precipitated by injecting a poor solvent while sufficiently stirring. After carrying out precipitation several 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, but examples thereof include water, methanol, ethanol, hexane, butyl cellosolve, acetone, and toluene.

＜ Polyimide ＞
The polyimide (the imidized polymer of the component (A)) used in the present invention can be produced by the imidization of the aforementioned polyimide or polyamic acid.

When a polyfluorene imide is produced from a polyfluorinated acid, the chemical fluorinated imine is easily added to the solution of the polyfluorinated acid obtained by the reaction of a diamine component and a tetracarboxylic dianhydride by adding a catalyst. In this chemical fluorene imidization, the fluorene imidization reaction is performed at a relatively low temperature. In the fluorene imidization process, it is preferable because it is difficult to cause the molecular weight of the polymer to decrease.
Chemical ammonium imidization can be performed by stirring polyimide acid to be imidized 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 in order to proceed with the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like. When acetic anhydride is used, it is preferable because purification after the reaction is easy.

The temperature for carrying out the above fluorene imidization reaction may be -20 to 140 ° C, preferably 0 to 100 ° C, and the reaction time is 0.5 to 100 hours, preferably 1 to 80 hours. The amount of alkaline catalyst is 0.5 to 30 mol times of Amic acid, preferably 2 to 20 mol times, and the amount of acid anhydride is 1 to 50 mol times of amine acid, preferably 3 to 30 mole times. The fluorenimidization rate of the obtained polymer can be adjusted by adjusting the amount of catalyst, temperature, and reaction time.

In the solution after the polyimide or polyimide acid imidization reaction, since the added catalyst and the like remain, the obtained imidimide polymer is recovered by means of the following methods, and organically The solvent is re-dissolved, and it is preferably used as the component (A) of the liquid crystal alignment agent of the present invention.
The polyimide solution obtained as described above can be poured into a poor solvent while sufficiently stirring to precipitate a polymer. After carrying out precipitation several times, washing with a poor solvent, and then drying at room temperature or heating, a purified polyimide powder can be obtained.
Although the said poor solvent is not specifically limited, Methanol, acetone, hexane, a butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, etc. are mentioned.

＜ (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).

However, the definitions of the symbols in the formula (1) are as described above.
The monovalent organic group in the formula (Q1-1) and the formula (Q1-2) is preferably an alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group.
L ¹ and L ² are hydrogen atoms. However, when Q ¹ is (Q1-1), for example, a compound represented by formula B-5-1 described later, L ¹ and L ² may form a single bond together.
S ¹ and S ² are each independently a base represented by the following formula (S).

In the formula, R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, L represents an alkylene group having 2 to 20 carbon atoms, and R ³ and R ⁴ are each independently an alkyl group having 1 to 4 carbon atoms and 2 carbon atoms. Alkenyl group of ∼4 or alkynyl group of 2-4 carbon, and q represents a natural number of 1-3. * Indicates a bond of the formula (1).

As the R ¹ monovalent organic group, a methyl group, a phenyl group, or a thermally decomposable leaving group is more preferred.

The so-called thermally decomposable leaving group is a substituent which is detached and replaced with a hydrogen atom by heating. Such a thermally decomposable leaving group is a protective group of an amine group, and the structure is not particularly limited as long as it is a functional group substituted with a hydrogen atom by heat. From the standpoint of storage stability of the liquid crystal alignment agent, the protective group D is preferably not detached at room temperature, preferably a protective group detached by heat above 80 ° C, and more preferably by heat above 100 ° C. Breakaway protection. D is particularly preferably a tert-butoxycarbonyl group or a 9-fluorenylmethoxycarbonyl group from the viewpoint of the temperature of the dissociation.

Preferable examples of the compound represented by (B) component include the following compounds (B-1) to (B-9).
(B-1): In the formula-based (1), q1 and q2 is 0, Q ¹ is (Q1-1), a hydrogen atom of L ¹ and L ² are,
(B-2): In the formula-based (1), q1 and q2 is 0, Q ¹ is (Q1-1), L ¹ and L ² together as a single bond, the
(B-3): In the formula-based (1), q1 and q2 is ^1, Q 1 is (Q1-1), Q ² is (Q1-1), a hydrogen atom of L ¹ and L ² are,
(B-4): In the formula-based (1), q1 and q2 is ^1, Q 1 is (Q1-1), Q ² is a single bond, a hydrogen atom of L ¹ and L ² are,
(B-5): In the formula-based (1), q1 and q2 is ^1, Q 1 is (Q1-1), Q ² is (Q1-1), L ¹ and L ² together as a single bond, the
(B-6): In the formula-based (1), q1 and q2 is ^1, Q 1 is a single bond, Q ² is (Q1-1), a hydrogen atom of L ¹ and L ² are,
(B-7): In the formula-based (1), q1 and q2 is ^1, Q 1 is (Q1-1), Q ² is a single bond, L ¹ and L ² together as a single bond, the
(B-8): In the formula-based (1), q1 and q2 is 0, Q ¹ is (Q1-2), L ¹ and L ² is the hydrogen atom.
(B-9): In the formula-based (1), q1 and q2 is ^1, Q 1 is (Q1-2), L ¹ and L ² is the hydrogen atom.

As a preferable specific example of the compound represented by (B) component, at least 1 sort (s) chosen from the group which consists of the compound represented by following formula B-1-1-formula B-9-1 is mentioned.

The compound of the component (B) of the present invention is obtained by reacting a diamine represented by the following formula (0) with a trialkoxysilylpropyl isocyanate by a known method.

Q in formula (0) of ^{1, Q 2, L 1,} L 2, q1 and q2 is the same system as defined above in formula (1) of. As the diamine represented by the equation (0), a known one can be used.

In the reaction between the diamine and the isocyanate, the amount of the isocyanate compound used is preferably 0.98 to 1.2 equivalent times, and more preferably 1.0 to 1.05 equivalent times relative to the amino group 1 group.

The reaction solvent is not particularly limited as long as it is inert to the reaction. Examples include hydrocarbons such as hexane, cyclohexane, benzene, toluene; halogen-based hydrocarbons such as carbon tetrachloride, chloroform, and 1,2-dichloroethane; diethyl ether, diisopropyl ether , 1,4-dioxane, tetrahydrofuran and other ethers; acetone, methyl ethyl ketone, methyl isobutyl ketone and other ketones; acetonitrile, propionitrile and other nitriles; ethyl acetate, ethyl propionate Carboxylic esters such as esters; N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-tetramethylene Nitrogen-containing aprotic polar solvents such as dihydroimidazolone; Sulfur-containing aprotic polar solvents such as dimethylsulfinium and cyclobutane; pyridines such as pyridine and methylpyridine. These solvents may be used alone or as a mixture of two or more of them. Toluene, acetonitrile, ethyl acetate, and tetrahydrofuran are preferred, and acetonitrile and tetrahydrofuran are even more preferred.

Although the amount of the solvent (reaction concentration) is not particularly limited, the reaction can be performed without using a solvent. When a solvent is used, the solvent can be used in an amount of 0.1 to 100 times by mass relative to the isocyanate compound. It is preferably 0.5 to 30 times by mass, and even more preferably 1 to 10 times by mass.

The reaction temperature is not particularly limited, but is, for example, -90 ° C to 150 ° C, preferably -30 ° C to 100 ° C, and even more preferably 0 ° C to 80 ° C. The reaction time is usually 1 minute to 200 hours, and preferably 30 minutes to 100 hours.

(B) When there are too many components, liquid crystal alignment will be affected, and when too few, the effect of this invention will not be acquired. Therefore, the addition amount of the component (B) is preferably 0.1 to 20% by mass, and more preferably 1 to 10% by mass, with respect to the component (A) (100% by mass).

＜ Liquid crystal alignment agent ＞
The liquid crystal alignment agent used in the present invention is in the form of a solution in which the compound represented by the formula (1) having the aforementioned (A) component, that is, the specific polymer (A) and (B) component, is dissolved in an organic solvent. The molecular weight of the specific structural polymer (A) is preferably 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.

Although the concentration of the specific polymer (A) of the liquid crystal alignment agent of the present invention can be appropriately changed by setting the thickness of the coating film to be formed, from the viewpoint of forming a uniform and defect-free coating film, it is preferably 1% by weight or more, and from the viewpoint of storage stability of the solution, 10% by weight or less is preferable, and 1 to 5% by weight is preferable.
The organic solvent contained in the liquid crystal alignment agent used in the present invention is preferably a good solvent that uniformly dissolves the specific polymer (A).
Examples of the organic solvent include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and dimethyl Sulfur, γ-butyrolactone, 1,3-dimethyl-tetrahydroimidazolone, methyl ethyl ketone, cyclohexanone, cyclopentanone or 4-hydroxy-4-methyl-2-pentanone, etc. .

Among the organic solvents, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and γ-butyrolactone are preferably used.
Furthermore, when the solubility in the solvent of the polymer of the present invention is high, it is preferable to use a solvent represented by the above formula [D-1] to [D-3].
The good solvent of 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 these, it is preferably 20 to 90% by mass. More preferably, it is 30 to 80% by mass.
The proposal was removed from the integration with paragraph 0077 and so on.

As the liquid crystal alignment agent of the present invention, a solvent (also referred to as a poor solvent) that improves the coating property or surface smoothness of the liquid crystal alignment film when the liquid crystal alignment agent is applied can be used. Although specific examples of the poor solvent are listed below, 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. 1-butanol, isoamyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl 2-Ethyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol Alcohol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 1,2-ethanediol, 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-pentanediol, 2-ethyl-1,3-hexanediol, dipropyl ether, dibutyl ether, dihexyl ether, dioxane, ethylene glycol di Methyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethyl ether Glycol methyl ethyl ether, diethylene glycol dibutyl ether, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 3-ethoxybutyl ethyl Ester, 1-methylpentyl Acid ester, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, 2- (formaldehyde) (Oxymethoxy) ethanol, ethylene 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 di Methyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetic acid Ester, ethylene glycol diacetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2- (2-ethoxyethoxy) ethyl acetate Ester, diethylene glycol acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, acetic acid n-butyl ester, propylene glycol monoethyl ether, methyl pyruvate , Ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxy Propionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, isoamyl lactate or the foregoing Solvents represented by Formula [D-1] to Formula [D-3], and the like.

Of these, 1-hexanol, cyclohexanol, 1,2-ethanediol, 1,2-propanediol, propylene glycol monobutyl ether, ethylene glycol monobutyl ether, or dipropylene glycol dimethyl is preferred. ether.
These poor solvents are preferably 1 to 80% by mass of the entire solvent contained in the liquid crystal alignment agent. Among these, 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 be added with a polymer other than the polymer described in the present invention, a dielectric or conductive for the purpose of changing the electrical properties such as the dielectric constant and conductivity of the liquid crystal alignment film. Substances, silane coupling agents for the purpose of improving the adhesion between the liquid crystal alignment film and the substrate, cross-linking compounds for the purpose of improving the hardness or density of the film when the liquid crystal alignment film is used, and further efficiently firing the coating film A perylene imidation accelerator and the like for the purpose of perylene imidization by heating of a polyimide precursor.

＜ Liquid crystal alignment film ＞
The liquid crystal alignment film of the present invention is a film obtained by applying the above-mentioned liquid crystal alignment agent to a substrate, followed by drying and firing. 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 or the like for driving the liquid crystal from the viewpoint of simplification of the manufacturing process. Moreover, in a reflective liquid crystal display element, not only a substrate on one side, but also an opaque object such as a silicon wafer can be used. In this case, an electrode that reflects 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 to 120 ° C for 1 to 10 minutes, and then fired at 150 to 300 ° C for 5 to 120 minutes. Although the thickness of the coating film after firing is not particularly limited, when it is too thin, the reliability of the liquid crystal display element may be reduced, so it is 5 to 300 nm, preferably 10 to 200 nm.

Examples of the method of the liquid crystal alignment film obtained by the alignment treatment include a rubbing method and a photo-alignment treatment method.
The rubbing treatment can be performed using an existing rubbing device. Examples of the material of the friction cloth at this time include cotton, nylon, and rayon. As conditions for the rubbing treatment, generally, conditions of 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 used. Then, it is washed with pure water or alcohol by ultrasonic waves and rubbed to remove the generated residue.

As a specific example of the photo-alignment treatment method, a method in which the surface of the coating film described above is irradiated with radiation deflected in a certain direction and further subjected to a heat treatment at a temperature of 150 to 250 ° C. to give the liquid crystal alignment energy can be mentioned. As the radiation, 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 order to improve the alignment of the liquid crystal, the coating film substrate may be heated at 50 to 250 ° C and irradiated with radiation. The radiation dose is preferably 1 to 10,000 mJ / cm ² , and particularly preferably 100 to 5,000 mJ / cm ² . The liquid crystal alignment film produced as described above can stably align liquid crystal molecules in a certain direction.
Since the higher the extinction ratio of polarized ultraviolet rays, the higher the anisotropy can be imparted, the better. Specifically, the extinction of the linearly polarized ultraviolet rays is preferably 10: 1 or more, and more preferably 20: 1 or more.

The film irradiated with the polarized radiation is then subjected to a contact treatment with a solvent containing at least one selected from the group consisting of water and an organic solvent.
The solvent used for the contact treatment is not particularly limited as long as it is a solvent that dissolves the resulting decomposed product by light irradiation. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, Butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, and cyclohexyl acetate. These solvents may be used in combination of two or more.
From the standpoint of versatility or safety, it is more preferable to be at least one selected from the group consisting of water, 2-propanol, 1-methoxy-2-propanol, and ethyl lactate. Particularly preferred are water, 2-propanol and a mixed solvent of water and 2-propanol.

In the present invention, the contact treatment with a solution containing a film irradiated with polarized radiation and an organic solvent is preferably performed by a sufficient contact treatment with a film and a liquid such as an immersion treatment, a spray treatment, and the like. Among them, a method of performing a dipping treatment in a solution containing an organic solvent for 10 seconds to 1 hour, more preferably 1 to 30 minutes is preferable. Although the contact treatment may be performed at normal temperature or heating, it is preferably performed at 10 to 80 ° C, and more preferably 20 to 50 ° C. Further, if necessary, means for improving the contact with ultrasound and the like can be implemented.
After the above contact treatment, in order to remove the organic solvent in the used solution, water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, etc. can be rinsed with a low boiling point solvent (Rinse) Or dry either or both.

Furthermore, in the film subjected to the contact treatment with the solvent, the solvent can be dried and the molecular chains in the film can be re-oriented at 150 ° C. or higher for the purpose.
The heating temperature is preferably 150 to 300 ° C. The higher the temperature, the more the realignment of the molecular chains is promoted. However, when the temperature is too high, the molecular chains may be decomposed. Therefore, the heating temperature is more preferably 180 to 250 ° C, and particularly preferably 200 to 230 ° C.
When the heating time is too short, the effect of realignment of the molecular chain may not be obtained. When the heating time is too long, the molecular chain may be decomposed. Therefore, it is preferably 10 seconds to 30 minutes, and more preferably 1 minute. ~ 10 minutes.

<Liquid crystal display element>
The liquid crystal display element of the present invention is characterized by including a liquid crystal alignment film obtained by the aforementioned 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.

As an example of a liquid crystal lattice manufacturing method, a liquid crystal display element having a passive array structure will be described as an example. A liquid crystal display element having an active array structure in which a switching element such as a TFT (Thin Film Transistor) is provided in each pixel portion constituting an image display.
First, a transparent glass substrate is prepared, and a common electrode is provided on a substrate on one side on a substrate on the other side. These electrodes can be ITO electrodes, for example, and can be patterned in such a manner that a desired image can be displayed. 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, for example, a film composed of SiO ₂ -TiO ₂ formed by 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 overlap the substrates on the other side so that the alignment film surfaces thereof face each other, and the periphery is adhered with a sealing material. In order to regulate the substrate gap, a sealing material is usually mixed with a spacer. Further, it is preferable that a spacer for regulating the gap of the substrate is also distributed on the in-plane portion where the sealing material is not provided. An opening portion capable of filling the liquid crystal from the outside is provided in a part of the sealing material.
Next, a liquid crystal material is injected into a space surrounded by the sealing material through the opening provided in the sealing material. Then, this opening is sealed with an adhesive. For the injection, a vacuum injection method can be used, and a method using capillary phenomenon in the atmosphere can also be used. Next, set the polarizer. Specifically, a pair of polarizing plates are attached to the surface opposite to the liquid crystal layer of two substrates. By going through the above steps, the liquid crystal display element of the present invention is obtained.

In the present invention, as the sealant, for example, hardening is performed by irradiation or heating with ultraviolet rays 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 or the like. Resin. Particularly preferred is a hardened resin system having reactive groups of both epoxy groups and (meth) acrylfluorenyl groups.
The sealing agent of the present invention may be blended with an inorganic filler for the purpose of improving adhesion and moisture resistance. It does not specifically limit as an inorganic filler which can be used. Specific examples include spherical silica, fused silica, crystalline silica, titanium oxide, titanium black, silicon carbide, silicon nitride, boron nitride, calcium carbonate, magnesium carbonate, barium sulfate, and calcium sulfate. , Mica, talc, clay, alumina, magnesia, zirconia, aluminum hydroxide, calcium silicate, aluminum silicate, lithium aluminum silicate, zirconium silicate, barium titanate, glass fiber, carbon fiber, molybdenum disulfide, Asbestos, etc. Among them, spherical silica, fused silica, crystalline silica, titanium oxide, titanium black, silicon nitride, boron nitride, calcium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, Alumina, aluminum hydroxide, calcium silicate, or aluminum silicate. The inorganic filler can be used in combination of two or more.

[Example]

Although specific examples of the present invention are listed below, the present invention is not limited to these examples. The meanings of the abbreviations of compounds and solvents are as follows. Here, Boc represents a third butoxycarbonyl group.

＜ Organic solvents ＞
NMP: N-methyl-2-pyrrolidone, BCS: butyl cellosolve
GBL: γ-butyrolactone, THF: tetrahydrofuran

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

<Synthesis of Additive S1>

In tetrahydrofuran (300 g), 4,4'-diamino-N-methyldiphenylamine (10.0 g, 43.2 mmol) was placed, and 3-triethoxysilylpropyl isocyanate (23.5 g) The solution diluted with tetrahydrofuran (50 g) was dropped over 1 hour. After completion of the dropping, the mixture was stirred at room temperature for 24 hours. The reaction solution was concentrated under reduced pressure to set the content to 128 g. After heating and dissolving at 60 ° C., acetonitrile (300 g) was added and the mixture was stirred at room temperature to precipitate crystals. The precipitated crystals were filtered, and the filtrate was dried to obtain the compound [S1] (yield: 22.8 g, yield: 75%, gray crystals).
1H-NMR (400MHz, DMSO-d6, δppm): 8.20 (s, 2H), 7.25 (d, 4H, J = 6.8 Hz), 6.81 (d, 4H, J = 6.8 Hz), 6.06 (t, 2H, J = 5.8 Hz), 3.75 (q, 12H, J = 7.5 Hz), 3.14 (s, 3H), 3.06-3.01 (m, 4H), 1.48-1.44 (m, 4H), 1.15 (t, 18H, J = 7.5 Hz), 0.57-0.53 (m, 4H).

<Synthesis of Additive S2>

Put [DA-4] (10.0g, 23.7mmol) in tetrahydrofuran (150g), and dilute the solution of 3-triethoxysilylpropylisocyanate (12.3g) with tetrahydrofuran (50g) under ice-cooling for 1 hour. dropping. After completion of the dropping, the mixture was stirred at room temperature for 24 hours. The reaction solution was concentrated under reduced pressure, and the content was adjusted to 50 g. Then, acetonitrile (100 g) was added and stirred at room temperature to precipitate crystals. The precipitated crystals were filtered, and the filtrate was dried to obtain a compound [S2] (yield: 16.9 g, yield: 78%, light brown crystals).
1H-NMR (400MHz, DMSO-d6, δppm): 8.11 (s, 2H), 7.83 (s, 2H), 7.50 (d, 2H, J = 8.8 Hz), 7.17 (d, 4H, J = 7.0 Hz) , 7.15 (d, 2H, J = 8.8 Hz), 6.72 (d, 4H, J = 7.0 Hz), 6.03-6.00 (m, 2H), 3.84 (s, 3H), 3.75 (q, 12H, J = 7.0 Hz), 3.25 (s, 6H), 3.05-2.99 (m, 4H), 1.48-1.43 (m, 4H), 1.14 (t, 18H, J = 7.0 Hz), 0.57-0.52 (m, 4H).

<Synthesis of Additive S3>

[DA-5] (1.50 g, 3.80 mmol) was placed in tetrahydrofuran (23 g), and a solution of 3-triethoxysilylpropyl isocyanate (1.98 g) diluted with tetrahydrofuran (7 g) under ice cooling took 5 minutes. dropping. After completion of the dropping, the mixture was stirred at room temperature for 18 hours, and then stirred at 50 ° C for 3 hours. Since intermediates remained, 3-triethoxysilylpropyl isocyanate (0.38 g) was added thereto, and the mixture was stirred at 50 ° C for 21 hours. Then, 3-triethoxysilylpropyl isocyanate (0.09 g) was further added, and it stirred at 50 degreeC for 6 hours. The reaction solution was concentrated under reduced pressure, and the content was adjusted to 10 g. Then, acetonitrile (15 g) was added and the mixture was stirred at room temperature to precipitate crystals. The precipitated crystal was filtered, and the filtrate was dried to obtain the compound [S3] (yield: 3.0 g, yield: 89%, thin purple crystal).
1H-NMR (400MHz, DMSO-d6, δppm): 8.36 (s, 2H), 7.41 (d, 4H, J = 6.8 Hz), 7.36 (d, 4H, J = 6.8 Hz), 7.02 (d, 4H, J = 6.8 Hz), 6.81 (d, 4H, J = 6.8 Hz), 6.13 (t, 2H, J = 5.8 Hz), 3.76 (q, 12H, J = 7.0 Hz), 3.22 (s, 6H), 3.08 -3.03 (m, 4H), 1.50-1.46 (m, 4H), 1.14 (t, 18H, J = 7.0 Hz), 0.58-0.54 (m, 4H).

<Synthesis of Additive S4>

1,4-phenylene diisocyanate (1.98 g, 12.3 mmol) was placed in acetonitrile (30 g), and 3-aminopropyltriethoxysilane (4.82 g) was diluted with acetonitrile (10 g) at room temperature. The solution took 1 hour to drip. After completion of the dropping, the mixture was stirred at room temperature for 18 hours. During this period, acetonitrile (90 g) was added due to poor stirring. After confirming the completion of the reaction by NMR, the precipitated crystals were filtered and the filtrate was dried to obtain the compound [S4] (yield: 6.3 g, yield: 94%, white crystals).
1H-NMR (400MHz, DMSO-d6, δppm): 8.16 (s, 2H), 7.20 (s, 4H), 6.04 (t, 2H, J = 5.6 Hz), 3.69 (q, 8H, J = 7.0 Hz) , 3.05-2.99 (m, 4H), 1.46-1.41 (m, 4H), 1.13 (t, 12H, J = 7.0 Hz), 0.55-0.50 (m, 4H), 0.06 (s, 6H).

＜ viscosity ＞
The viscosity of the polymer solution used in the following synthesis example 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 ℃.

(Synthesis example 1)
In a 200 mL four-necked flask with a stirring device and a nitrogen introduction tube, DA-1 (4.03 g, 16.5 mmol), DA-2 (3.59 g, 9.0 mmol) and DA-3 (2.51 g, 4.5 mmol) were added. Further, NMP (74.0 g) was added, and the solution was stirred and dissolved while being transported with nitrogen. While stirring this solution, CA-1 (4.37 g, 19.5 mmol) and 9.0 g of NMP were added, and stirred at 40 ° C for 3 hours. Then, CA-2 (1.71 g, 8.7 mmol) and 9.0 g of NMP were added at 25 ° C, and the mixture was further stirred for 12 hours to obtain a polyamic acid solution (viscosity: 480 mPa ･ s). The molecular weight of this polyamic acid is Mn = 10,660 and Mw = 20,512.

80.0 g of this polyamic acid solution was fractionated, 20.0 g of NMP was added, 6.8 g of acetic anhydride and 1.8 g of pyridine were added, and the mixture was reacted at 50 ° C. for 3 hours. While stirring this reaction solution in 434.4 g of methanol, the precipitate was separated by filtration. This precipitate was washed with methanol and dried under reduced pressure at 60 ° C to obtain a polyimide powder. The polyimide has an imidization rate of 75%. 20.0 g of the obtained polyfluorene imide powder was added with 80.0 g of NMP and stirred at 70 ° C. for 20 hr to dissolve to obtain a polyfluorene imine solution (SPI-A1).

[Examples 1 to 3] and [Comparative Examples 1 to 2]
The polyamino acid solution obtained in Synthesis Example 1 was stirred so as to have the composition shown in Table 1 of the solvent in the obtained liquid crystal alignment agent, while the solvent and additives S1, S2, or S3 were added, and further stirred at room temperature. 2 hours, and the liquid crystal aligning agent was 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.

Hereinafter, a manufacturing method of a liquid crystal lattice for evaluating the relaxation characteristics, flicker characteristics, and liquid crystal alignment of the accumulated charge is shown.
A liquid crystal lattice having a structure of a liquid crystal display element of the FFS method was produced. Initially prepare the substrate with electrodes. The substrate was a glass substrate having a length of 30 mm, a width of 35 mm, and a thickness of 0.7 mm. As the first layer on the substrate, the IZO electrode constituting the counter electrode is formed on the entire surface. 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 had a thickness of 500 nm and was used as an interlayer insulating film. On the second layer of the SiN film, as the third layer, comb-shaped pixel electrodes formed by the patterned IZO film are arranged to form two pixels of the first pixel and the second pixel. The size of each pixel is 10 mm in length and about 5 mm 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-like shape formed by a plurality of electrode elements arranged in a “く” shape with a curved central portion. The width in the lateral direction of each electrode element is 3 μm, and the interval between the electrode elements is 6 μm. Since the pixel electrode forming each pixel is composed of a plurality of electrode elements with a “く” shape that is curved at the central portion, the shape of each pixel is not rectangular, but is the same as the electrode element. The central portion is provided with a similar curved bold. "く 字" shape. In addition, each pixel divides the central curved portion into upper and lower portions as a boundary line, and has a first region on the upper side of the curved portion 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 element constituting the pixel electrode is different. That is, when the rubbing direction of the liquid crystal alignment film described later is used as a reference, it is formed in the first region of the pixel so that the electrode element of the pixel electrode becomes an angle (clockwise) of + 10 °, and in the second region of the pixel, The pixel element is formed so that the electrode element has an angle (clockwise) of -10 °. That is, in the first region and the second region of each pixel, the direction of the liquid crystal's turning action (on the plane ･ switch) in the substrate surface induced by the voltage application between the pixel electrode and the counter electrode is in the direction of each other. It is configured in a reverse direction.

Next, the liquid crystal alignment agents obtained in the examples and comparative examples were filtered by a filter having a pore diameter of 1.0 μm, and then applied to the prepared substrate with electrodes by spin coating. 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 rayon cloth (roller diameter: 120mm, roll revolution: 500rpm, moving speed: 30mm / sec, press-in length: 0.3mm, rubbing direction: IZO comb with respect to the third layer After the tooth electrode is tilted in a direction of 10 °), ultrasonic waves are irradiated in pure water for 1 minute and washed to remove water droplets by blowing air. 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 glass substrate having a columnar spacer having a height of 4 μm on which an ITO electrode was formed on the back surface was also carried out in the same manner as described above, and a polyimide film was formed, and alignment processing was performed in the same procedure as above. A substrate with a liquid crystal alignment film. Take these two substrates with a liquid crystal alignment film as a group, and print a sealant on the substrate in the form of a residual liquid crystal injection port. The other substrate faces the liquid crystal alignment film surface and is bonded in such a way that the rubbing direction becomes antiparallel. . Then, the sealant was hardened to produce an empty lattice having a lattice gap of 4 μm. A liquid crystal MLC-3019 (manufactured by Merck) was injected into the empty lattice by a reduced pressure injection method, and the injection port was sealed to obtain an FFS liquid crystal lattice. Then, the obtained liquid crystal lattice was heated at 120 ° C. for 1 hour, and left at 23 ° C. for a while to evaluate the alignment of the liquid crystal.

<Mitigation characteristics of accumulated charge>
The above-mentioned liquid crystal lattice is arranged between two polarizing plates arranged such that the polarizing axes are orthogonal to each other, and the short-circuited pixel electrode and the counter electrode are at the same potential. The LED backlight is illuminated from under the two polarizing plates, and two The angle of the liquid crystal lattice is adjusted in such a way that the brightness of the transmitted light of the LED backlight measured on the polarizing plate is minimized.
Next, while applying a rectangular wave with a frequency of 30 Hz to this liquid crystal lattice, the VT characteristic (voltage-transmittance characteristic) at a temperature of 23 ° C. was measured, and an AC voltage having a relative transmittance of 23% was calculated. Since this AC voltage corresponds to a region where the brightness of the voltage changes greatly, it is convenient to pass the accumulated charge through the brightness evaluation.
Secondly, at a temperature of 23 ° C, an AC voltage having a relative transmittance of 23%, and after applying a rectangular wave with a frequency of 30 Hz for 5 minutes, a DC voltage of +1.0 V was superimposed for 30 minutes. Then, the DC voltage was turned off, and the AC voltage having a relative transmittance of 23% was applied again, and a rectangular wave having a frequency of only 30 Hz was applied for 15 minutes.
The faster the accumulated charge is relaxed, the faster the charge accumulation of the liquid crystal lattice when the DC voltage is superimposed. Therefore, the easing characteristics of the accumulated electric charge are reduced from the relative transmittance immediately after the superimposed DC voltage is reduced to more than 2% Take time to evaluate. That is, a case where the relative transmittance is reduced by 2% or more within 30 minutes is defined as "good", and a case where the relative reduction rate cannot be reduced by 2% or more even after 30 minutes is defined as "bad" for evaluation.

<Evaluation of liquid crystal alignment>
Using this liquid crystal lattice, an AC voltage of 9VPP was applied at a frequency of 30 Hz in a constant temperature environment at 60 ° C for 190 hours. Then, it is in a state between the pixel electrode and the counter electrode of the short-circuited liquid crystal lattice, and is left to stand at room temperature for one day.
After being placed, the liquid crystal lattice is set between two polarizing plates arranged orthogonally to the polarization axis, and the backlight is turned on with no applied voltage, and the arrangement angle of the liquid crystal lattice is adjusted so that the brightness of transmitted light becomes the smallest. . Then, from the angle at which the second region of the first pixel becomes darkest to the angle at which the first region becomes darkest, the rotation angle when the liquid crystal lattice is rotated is calculated as the angle Δ. The same is applied to the second pixel, and the second region and the first region are compared to calculate the same angle Δ. Then, 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 lattice. A case where the value of the angle Δ of the liquid crystal lattice is less than 0.2 degrees is defined as "good", and a case where the value of the angle Δ is 0.2 degrees or more is defined as "bad" and evaluated.

<Evaluation of voltage holding ratio (VHR)>
A voltage of 1 V was applied to the obtained liquid crystal lattice at a temperature of 60 ° C. for 60 μs, the voltage after 50 ms was measured, and how long the voltage could be maintained was calculated as the voltage retention rate. The measurement of the voltage holding ratio is a voltage holding ratio measuring device VHR-1 manufactured by Toyo Technica.

<Evaluation of optical characteristics (transparency)>
A quartz substrate with a length of 40 mm, a width of 40 m, and a thickness of 1.0 mm was prepared. Next, the liquid crystal alignment agent was filtered through 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 then 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 was performed by measuring the transmittance of the substrate obtained by the aforementioned method. Specifically, UV-3600 (manufactured by Shimadzu Corporation) was used in the measurement device, and the transmittance was measured under conditions of a temperature of 25 ° C. and a scanning wavelength of 300 to 800 nm. At this time, the reference (reference example) was used without any coated quartz substrate. The average transmittance at a wavelength of 400 to 800 nm was calculated by evaluation. The higher the transmittance, the better the transparency.

＜ Evaluation results ＞
For the liquid crystal display elements using the liquid crystal alignment agents of Examples 1 to 3 and Comparative Examples 1 to 2, the results of the evaluation of the afterimage erasing time, the stability evaluation of the liquid crystal alignment, and the evaluation of the transparency, as described above, are shown于 表 2。 In Table 2.

* 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 can be seen from Table 2, the liquid crystal display elements using the liquid crystal alignment agents of Examples 1 to 3 were judged to have excellent voltage retention, rapid relaxation of accumulated charge, and good liquid crystal alignment or transparency.

[Industrial availability]

The liquid crystal alignment agent of the present invention is widely used in a liquid crystal display element having a vertical electric field method such as a TN method or a VA method, and a lateral electric field method such as an IPS method or an FFS method.
The entire contents of the specification, scope and abstract of Japanese Patent Application No. 2018-51091 filed on March 19, 2018, are incorporated herein by reference for the disclosure of the specification of the present invention.

Claims (12)

A liquid crystal alignment agent characterized by containing the following components (A), (B), and an organic solvent, (A) component: selected from a polyimide precursor having a structure represented by the following formula (2), and A polymer of at least one of the group consisting of a polyimide polymer of the polyimide precursor However, in formula (1), R ⁵ is a single bond or a divalent organic group; R ⁶ is a structure represented by-(CH ₂ ) _n- , and any of -CH ₂ -may be substituted with non-adjacent conditions. Bonding of ether, ester and amidine; R ⁷ is a single bond or a divalent organic group; any hydrogen atom on the benzene ring may be substituted by a monovalent organic group; n is an integer from 2 to 20; (B) Ingredients: Compound represented by the following formula (1) However, in Formula (1), Q ¹ and Q ² are each independently selected from one of the following (Q1-1), (Q1-2), and single bond, but in Formula (1), Q ¹ and Q ² of a medium is at least one selected from (Q1-1) and (Q1-2); R ¹ is a hydrogen atom or a monovalent organic group; q1 and q2 are independently 0 or 1; L ¹ and L ² are hydrogen atoms; however, when Q ¹ is (Q1-1), L ¹ and L ² may form a single bond together; S ¹ and S ² are independently A base represented by the following formula (S); However, in formula (S), R ² is a hydrogen atom or an alkyl group; L is an alkylene group having 2 to 20 carbon atoms; R ³ and R ⁴ are each independently an alkyl group having 1 to 4 carbon atoms and 2 to 2 carbon atoms. Alkenyl group of 4 or alkynyl group of 2 to 4 carbons; q represents a natural number of 1 to 3; * represents a bond to formula (1). The liquid crystal alignment agent according to claim 1, wherein the component (A) contains a polyimide precursor selected from the group consisting of a structural unit represented by the following formula (3) and a polyimide of the polyimide precursor Polymers of at least one of the polymers; However, in formula (3), X ³ is a tetravalent organic group derived from a tetracarboxylic acid derivative; Y ³ is a divalent organic group derived from a diamine containing a structure of formula (2); R ¹³ is a hydrogen atom Or an alkyl group having 1 to 5 carbon atoms. For example, the liquid crystal alignment agent of claim 2, wherein the aforementioned polyfluorene imide precursor system contains 20 to 100 mol% of the structural unit represented by the aforementioned formula (3) with respect to the full structural unit it has. The liquid crystal alignment agent according to any one of claims 1 to 3, wherein the component (B) is at least one compound selected from the group consisting of the following (B-1) to (B-9); (B-1): Compounds based on the aforementioned formula (1), q1 and q2 being 0, Q ¹ being (Q1-1), L ¹ and L ² being hydrogen atoms, and (B-2): based on the aforementioned formula (1), q1, q2 is 0, Q ¹ is ^{(Q1-1), L 1, L} 2 together into the single bond compound, (B-3): based on the formula (1), q1, q2 is 1 , Q ¹ is (Q1-1), Q ² is (Q1-1), L ¹ and L ² are compounds of a hydrogen atom, (B-4): is in the aforementioned formula (1), q1 and q2 are 1, Q ¹ is (Q1-1), Q ² is a single bond, L ¹ and L ² are compounds of a hydrogen atom, and (B-5): is in the aforementioned formula (1), q1 and q2 are 1, and Q ¹ is ( Q1-1), Q ² is (Q1-1), a compound in which L ¹ and L ² together form a single bond, (B-6): is in the aforementioned formula (1), q1 and q2 are 1, and Q ¹ is single Bond, Q ² is (Q1-1), L ¹ and L ² are compounds of hydrogen atom, (B-7): It is in the above formula (1), q1 and q2 are 1, Q ¹ is (Q1-1) , Q ² is a single bond, and L ¹ and L ² together form a single bond compound, (B-8): It is in the aforementioned formula (1), q1 and q2 are 0, Q ¹ is (Q1-2), and L ¹ , L ² is a hydrogen atom The compound, (B-9): based on the Formula (1), q1, q2 is ^1, Q 1 is ^{(Q1-2), L 1, L} 2 is the hydrogen atom. The liquid crystal alignment agent according to any one of claims 1 to 3, wherein the component (B) is at least one selected from the group consisting of the following formulas B-1-1 to B-9-1 compound of; . The liquid crystal alignment agent according to any one of claims 1 to 5, wherein the organic solvent is N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2- Pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfene, γ-butyrolactone, 1,3-dimethyl-tetrahydroimidazolone, methyl ethyl ketone, cyclohexanone, cyclopentanone or 4-hydroxy-4-methyl-2-pentanone. The liquid crystal alignment agent according to claim 6, wherein the organic solvent includes a solvent that improves the coating property or surface smoothness of the liquid crystal alignment film when the liquid crystal alignment agent is applied. The liquid crystal alignment agent according to any one of claims 1 to 7, which contains the polymer containing the component (A) in the liquid crystal alignment agent, and contains 1 to 10% by mass. In the liquid crystal alignment agent according to any one of claims 1 to 8, the component (B) contains 0.1 to 20% by mass with respect to the component (A). A liquid crystal alignment film is obtained from the liquid crystal alignment agent according to any one of claims 1 to 9. A liquid crystal display element is provided with the liquid crystal alignment film according to claim 10. The liquid crystal display device according to claim 11, wherein the display device is a transverse electric field method.