KR102482055B1 - Liquid crystal aligning agent, liquid crystal aligning film, and liquid crystal display element - Google Patents

Abstract

(식 [1] 중, Y¹ 은 S 원자 또는 O 원자를 나타내고, * 는, 다른 기에 결합하는 부위를 나타낸다. 또, 벤젠 고리의 임의의 수소 원자는, 1 가의 유기기로 치환되어 있어도 된다.)The polymer obtained from the diamine component containing the diamine which has a structure represented by following formula [1], and an organic solvent are included.
[Formula 1]

(In formula [1], Y ¹ represents an S atom or an O atom, and * represents a site bonded to another group. In addition, an arbitrary hydrogen atom in the benzene ring may be substituted with a monovalent organic group.)

Description

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

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

BACKGROUND OF THE INVENTION A liquid crystal display element is currently widely used as a display device that realizes a thin shape and a light weight. It is known that the display properties of a liquid crystal display device are greatly influenced by the orientation of liquid crystal, the size of the pretilt angle of the liquid crystal, the stability of the pretilt angle, and the electrical properties. , The liquid crystal aligning film which directly contacts the liquid crystal and determines the alignment state becomes important, as well as the liquid crystal material to be used.

Currently, the liquid crystal alignment film mainly uses a polyamic acid or a polyimide resin solution as a liquid crystal alignment agent, and after applying them to a substrate, firing is performed, and the surface of the coating film is applied with pressure with rayon or nylon cloth and rubbed, It is formed by performing a so-called rubbing process.

The method of obtaining a liquid crystal alignment film from polyimide or polyamic acid as a precursor thereof is a simple process of applying and firing a resin solution to produce a coating film excellent in heat resistance and solvent resistance, and the liquid crystal can be easily oriented by rubbing In , it has been widely spread industrially and has reached the present.

In addition, in order to improve the display characteristics of the liquid crystal display element, by selecting various structures of polyamic acid or polyimide or blending resins having different characteristics, further improvement of liquid crystal orientation, control of pretilt angle, and Numerous techniques have been proposed, such as improvement in stability, improvement in voltage retention, difficulty in accumulating accumulated charges with respect to DC voltage, and improvement in ease of detachment of accumulated charges. For example, Patent Literature 1 proposes using a polyimide resin having a specific repeating unit in order to obtain a high voltage holding ratio. Further, Patent Literature 2 proposes using a soluble polyimide having a nitrogen atom in addition to an imide group to shorten the time until the afterimage is eliminated with respect to the afterimage phenomenon.

However, as the performance of liquid crystal display elements, power saving of display devices, improvement of durability in various environments, etc. progress, there is a problem that the voltage retention in a high-temperature environment is low and the contrast is lowered, and the problem of long-term continuous driving The problem of display burn-in due to charge accumulation at the time of application has become significant, and it is becoming difficult to simultaneously solve both of these issues only with conventionally proposed techniques.

Japanese Unexamined Patent Publication No. Hei 2-287324 Japanese Unexamined Patent Publication No. 10-104633

In view of such circumstances, an object of the present invention is to provide a liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element in which the relaxation of the accumulated electric charge is quick and the transparency, solubility, and orientation are improved.

As a result of intensive research, the inventors of the present invention have found that using a specific diamine is very effective for shortening the relaxation time of accumulated electric charges, and has completed the present invention.

The liquid crystal aligning agent of this invention which achieves the said objective is characterized by including the polymer obtained from the diamine component containing the diamine which has a structure represented by following formula [1], and an organic solvent.

[Formula 1]

(In formula [1], Y ¹ represents an S atom or an O atom, and * represents a site bonded to another group. In addition, an arbitrary hydrogen atom in the benzene ring may be substituted with a monovalent organic group.)

It is preferable that the said polymer is at least 1 sort(s) of polymer chosen from the group which consists of a polyimide precursor which is a polycondensate of the diamine and tetracarboxylic dianhydride which have the structure shown by the said Formula [1], and the polyimide which is an imide product. Do.

Moreover, the said diamine is characterized by being represented by following formula [2].

[Formula 2]

(In formula [2], the definition of Y ¹ is the same as in formula [1], R ² each independently represents a single bond or a structure of formula [3] below, and n represents an integer of 1 to 3 Arbitrary hydrogen atoms of the benzene ring may be substituted with monovalent organic groups.)

[Formula 3]

(In formula [3], R ³ is a single bond, -O-, -COO-, -OCO-, -(CH ₂ ) _l -, -O(CH ₂ ) _m O-, -CONH- and -NHCO - Represents a divalent organic group selected from (l and m represent an integer of 1 to 5), * ₁ represents a site bonding to a benzene ring in formula [2], * ₂ represents an amino group in formula [2] Indicates the binding site.)

Moreover, it is preferable that the said polymer is at least 1 sort(s) chosen from the polyimide which is the polyimide precursor containing the structural unit represented by following formula [4], and its imide compound.

[Formula 4]

(In formula [4], X ¹ is a tetravalent organic group derived from a tetracarboxylic acid derivative, and W ¹ is a divalent organic group derived from diamine having a structure represented by formula [2] or formula [3] R ⁴ and R ⁵ represent 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 5 carbon atoms, and an alkyl group having 2 to 5 carbon atoms. represents an alkenyl group of 5 or an alkynyl group of 2 to 5 carbon atoms.)

The liquid crystal aligning film of this invention which achieves the said objective is obtained from the said liquid crystal aligning agent, It is characterized by the above.

The liquid crystal display element of this invention which achieves the said object is characterized by being provided with the said liquid crystal aligning film.

ADVANTAGE OF THE INVENTION According to this invention, the relief|moderation of accumulated electric charge is quick, and the liquid crystal aligning agent and liquid crystal aligning film and liquid crystal display element with improved transparency, solubility, or orientation can be provided.

Hereinafter, the present invention will be described in more detail.

<diamine>

Although the liquid crystal aligning agent of this invention contains the polymer obtained from the diamine component containing the diamine which has a structure shown by following formula [1], and an organic solvent, a diamine is demonstrated first.

[Formula 5]

(In formula [1], Y ¹ represents an S atom or an O atom, and * represents a site bonded to another group. In addition, an arbitrary hydrogen atom in the benzene ring may be substituted with a monovalent organic group.)

In formula [1], as a monovalent organic group, it is a hydrocarbon group; a hydrocarbon group containing a hydroxyl group, a carboxyl group, a hydroxyl group, a thiol group or a carboxyl group; Hydrocarbon groups linked by bonding groups such as ether bonds, ester bonds, and amide bonds; Hydrocarbon group containing a silicon atom; Halogenated hydrocarbon group; amino group; and an inactive group in which an amino group is protected by a carbamate-based protecting group such as a t-butoxycarbonyl group. Further, the hydrocarbon group may be a straight chain, branched chain, or cyclic chain, and may be either a saturated hydrocarbon or an unsaturated hydrocarbon. In addition, some of the hydrogen atoms of the hydrocarbon group may be substituted with a carboxyl group, a hydroxyl group, a thiol group, a silicon atom, a halogen atom, or the like, or linked by a bonding group such as an ether bond, an ester bond, or an amide bond.

Moreover, any of a linear chain, branched chain, and cyclic chain may be sufficient as a C1-C3 alkylene group. Specifically, a methylene group, an ethylene group, an n-propylene group, an isopropylene group, a cyclopropylene group, a 1-methyl-cyclopropylene group, a 2-methyl-cyclopropylene group, a 1,1-dimethyl-n-propylene group, 1,2-dimethyl-n-propylene group, 2,2-dimethyl-n-propylene group, 1-ethyl-n-propylene group, 1,2-dimethyl-cyclopropylene group, 2,3-dimethyl-cyclopropylene group , 1-ethyl-cyclopropylene group, 2-ethyl-cyclopropylene group, 1,1,2-trimethyl-n-propylene group, 1,2,2-trimethyl-n-propylene group, 1-ethyl-1-methyl -n-propylene group, 1-ethyl-2-methyl-n-propylene group, 2-n-propyl-cyclopropylene group, 1-isopropyl-cyclopropylene group, 2-isopropyl-cyclopropylene group, 1,2 ,2-trimethyl-cyclopropylene group, 1,2,3-trimethyl-cyclopropylene group, 2,2,3-trimethyl-cyclopropylene group, 1-ethyl-2-methyl-cyclopropylene group, 2-ethyl-1 -Methyl-cyclopropylene group, 2-ethyl-2-methyl-cyclopropylene group, 2-ethyl-3-methyl-cyclopropylene group, etc. are mentioned.

In addition, various types of monovalent organic groups and alkylene groups having 1 to 3 carbon atoms can be selected depending on the application.

In the structure of the above formula [1], the bonding position of the benzene ring to the 5-membered ring is the carbon atom next to Y ¹ on the 5-membered ring, as represented by the following formula [1-1] in terms of charge transfer It is preferable to be

[Formula 6]

The said specific diamine can be represented by following formula [1-2], for example, Diamine represented by following formula [1-3] is preferable especially, Furthermore, diamine represented by formula [1-4] more preferable

[Formula 7]

[Formula 8]

[Formula 9]

In the formulas [1-2] to [1-4], the definition of Y ¹ is the same as in the case of the formula [1], and Q ¹ and Q ² are each independently a single bond or a divalent organic group , that is, Q ¹ and Q ² may have mutually different structures. Moreover, the two _Q2 in formula [1-4] may have mutually different structures. In addition, the arbitrary hydrogen atoms of a benzene ring may be substituted by the monovalent organic group similarly to the case of said formula [1].

As a preferable example of the said specific diamine, the diamine represented by following formula [2] is mentioned, More preferably, it is diamine represented by formula [2-1].

[Formula 10]

[Formula 11]

The definition of Y ¹ in the formula [2] and formula [2-1] is the same as in formula [1]. Two R< ² > represents the structure of a single bond or the following formula [3] each independently. In addition, as in the case of the above formula [1], the arbitrary hydrogen atoms of the benzene ring may be substituted with a monovalent organic group.

[Formula 12]

In the formula (3), R ³ is a single bond, -O-, -COO-, -OCO-, -(CH ₂ ) _l -, -O(CH ₂ ) _m O- , -CONH-, and - Represents a divalent organic group selected from the group consisting of NHCO-, wherein l and m represent integers of 1 to 5. Especially, from the point of alleviation|relaxation of accumulated charge, R< ₃ > has a single bond, -O-, -COO-, -OCO-, -CONH-, or -NHCO- is preferable. Moreover, * ₁ represents the site|part couple|bonded with the benzene ring in Formula [2], and * ₂ represents the site|part couple|bonded with the amino group in Formula [2].

n in said formula [2] and formula [2-1] represents the integer of 1-3. Preferably it is 1 or 2.

As a specific example of diamine represented by formula [2], although diamine represented by following formula [4-1-1] - [4-1-12] can be illustrated, it is not limited to these. Among them, [4-1-1], [4-1-2], [4-1-4] to [4-1-12] are preferable from the viewpoint of the relaxation of the accumulated electric charge and the orientation, and [4-1-12] is preferred. -1-1], [4-1-2], [4-1-8] to [4-1-12] are particularly preferred.

[Formula 13]

<Method for synthesizing diamine>

Next, the main synthesis method of the diamine of this invention is demonstrated. In addition, the method demonstrated below is a synthesis example, and is not limited to this.

The diamine of the present invention can be obtained by reducing a dinitro compound to convert a nitro group into an amino group, as shown in the following reaction formula. In the reaction formulas below, diamines in which hydrogen atoms in the benzene ring and saturated hydrocarbon moieties are not substituted with halogen atoms such as fluorine atoms or monovalent organic groups other than amino groups are described as examples.

[Formula 14]

The method for reducing the dinitro compound is not particularly limited, and palladium-carbon, platinum oxide, Raney nickel, platinum black, rhodium-alumina, platinum sulfide carbon, etc. are used as catalysts, and ethyl acetate, toluene, tetrahydrofuran, dioxane , a method of performing reduction with hydrogen gas, hydrazine, hydrogen chloride or the like in a solvent such as alcohol can be exemplified. You may carry out under pressure using an autoclave etc. as needed. On the other hand, when an unsaturated bond site is included in the structure of a substituent substituting a hydrogen atom in a benzene ring or a saturated hydrocarbon moiety, when palladium carbon or platinum carbon is used, the unsaturated bond site is reduced and becomes a saturated bond. Since there is a concern, reduction conditions using reduced iron, tin, or a transition metal such as tin chloride as a catalyst are preferred.

The reaction can be carried out in the presence of a base. The base to be used is not particularly limited as long as it can be synthesized, but inorganic bases such as potassium carbonate, sodium carbonate, cesium carbonate, sodium alkoxide, potassium alkoxide, sodium hydroxide, potassium hydroxide, sodium hydride, pyridine, dimethylaminopyridine, trimethylamine, triethyl Organic bases, such as an amine and a tributylamine, etc. are mentioned. In some cases, the yield can be improved by using a palladium catalyst such as dibenzylideneacetone palladium or diphenylphosphinoferrocene palladium or a copper catalyst in combination.

The diamine of the present invention obtained in this way can be used as a raw material for polyimide precursors such as polyamic acid and polyamic acid ester, polyimide, polyurea, polyamide, etc. (these are collectively referred to as "polymer"). Although this polymer can be used as a liquid crystal aligning agent by dissolving in a predetermined organic solvent, for example, it is not limited to the use. Hereinafter, the polymer containing the diamine represented by Formula [1] in the structure is demonstrated.

<Polymer>

The polymer of this invention is obtained using the above-mentioned diamine of this invention or its derivative(s) (mentioned later), and has a structure represented by following formula [1] derived from a diamine component.

[Formula 15]

(In formula [1], Y ¹ represents an S atom or an O atom, and * represents a site bonded to another group. In addition, an arbitrary hydrogen atom in the benzene ring may be substituted with a monovalent organic group.)

As a structure represented by said formula [1] derived from the diamine component of such a polymer, what has a structure represented by following formula [2-2] is preferable.

[Formula 16]

(In the formula [2-2], the definition of Y ¹ is the same as in the formula [1], R ² each independently represents a single bond or a structure of the following formula [3], and n is 1 to 3 Indicates an integer, and * ₂ indicates a site bonded to another group. Any hydrogen atom in the benzene ring may be substituted with a monovalent organic group.)

[Formula 17]

(In formula [3], R ³ is a single bond, -O-, -COO-, -OCO-, -(CH ₂ ) _l -, -O(CH ₂ ) _m O-, -CONH- and -NHCO - represents a divalent organic group selected from (l and m represent integers from 1 to 5), * ₁ represents a site bonding to the benzene ring in formula [2], and * ₂ represents a site bonding to another group .)

Here, as a derivative of the diamine of the present invention, diamine having a structure in which two or more of the above structures are linked, or a structure in which the above structures are linked through -O-, -S-, -COO- or -OCO- can be heard Moreover, the structure derived from a diamine component may also contain the structure (mentioned later) derived from another diamine other than the structure of Formula [2].

Moreover, as a monovalent organic group in Formula [2] and a C1-C3 alkylene group, the thing similar to Formula [1] is mentioned.

Moreover, it is preferable that the polymer of this invention is at least 1 sort(s) chosen from the polyimide which is the polyimide precursor containing the structural unit represented by following formula [4] from a viewpoint of use as a liquid crystal aligning agent, and its imide compound.

[Formula 18]

(In formula [4], X ¹ is a tetravalent organic group derived from a tetracarboxylic acid derivative, and W ¹ is a divalent organic group derived from diamine having a structure represented by formula [2] or formula [3] R ⁴ and R ⁵ represent 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 5 carbon atoms, and an alkyl group having 2 to 5 carbon atoms. represents an alkenyl group of 5 or an alkynyl group of 2 to 5 carbon atoms.)

In Formula [4], as a C1-C5 alkyl group, for example, a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, n -A pentyl group, an isopentyl group, a s-pentyl group, a t-pentyl group, etc. are mentioned. Examples of the alkenyl group having 2 to 5 carbon atoms include a vinyl group, an allyl group, a 1-propenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 1-pentenyl group, 2-pentenyl group, 3-pentenyl group, 4-pentenyl group, etc., and an alkynyl group having 2 to 5 carbon atoms. Examples of the group include ethynyl group, 1-propynyl group, 2-propynyl (propargyl) group, 3-butynyl group, and pentynyl group. Among these, from the viewpoint of the ease of progress of the imidation reaction during heating, R ¹ and R ² are preferably a hydrogen atom, a methyl group, or an ethyl group, more preferably a hydrogen atom or a methyl group, and from the viewpoint of liquid crystal orientation, A ¹ and A ² is preferably a hydrogen atom or a methyl group.

As long as X ¹ is a tetravalent organic group derived from a tetracarboxylic acid derivative, the structure thereof is not particularly limited. In addition, X ¹ is appropriately selected depending on the degree of properties required, such as solubility in a solvent of a polymer, applicability of a liquid crystal aligning agent, orientation of a liquid crystal when used as a liquid crystal aligning film, voltage retention, and stored electric charge. , One type may be sufficient in the same polymer, and two or more types may be mixed.

X ¹ is tetracarboxylic acid dianhydride, as well as tetracarboxylic acid derivatives such as tetracarboxylic acid, tetracarboxylic acid dihalide compound, tetracarboxylic acid dialkyl ester compound or tetracarboxylic acid dialkyl ester dihalide compound. can also be used As tetracarboxylic dianhydride or its derivative, it is more preferable to use at least 1 selected from the tetracarboxylic dianhydride represented by following formula [5] or its derivative(s).

[Formula 19]

In Formula [5], V ¹ is a tetravalent organic group having an alicyclic structure, and the structure is not particularly limited. As a specific example, following formula [V ^1-1 ] - formula [V ^1-44 ] are mentioned.

[Formula 20]

[Formula 21]

[Formula 22]

[Formula 23]

[Formula 24]

[Formula 25]

In the formula [V ^1-1 ] to the formula [V ^1-4 ], R ⁷ to R ²⁷ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or a carbon atom having 2 to 6 carbon atoms. an alkenyl group, an alkynyl group of 2 to 6 carbon atoms, a monovalent organic group of 1 to 6 carbon atoms containing a fluorine atom, or a phenyl group, which may be the same or different. From the viewpoint of liquid crystal orientation, R ⁷ to R ²⁷ preferably have a hydrogen atom, a halogen atom, a methyl group or an ethyl group, and more preferably a hydrogen atom or a methyl group.

As a specific structure of formula [V ^1-1 ], the structure shown by the following formula [V 1-1-1 ^] - formula [V 1-1-6 ^] is mentioned. A structure represented by the following formula [V 1-1-1 ^] from the viewpoint of liquid-crystal alignment and photoreaction sensitivity is particularly preferred.

[Formula 26]

In Formula [4], as long as W ¹ is a divalent organic group derived from diamine having a structure represented by Formula [1] or Formula [2], the structure is not particularly limited, even if two or more types are mixed. do. In addition, W ¹ corresponds to the structure of the diamine component used in the present invention, and has a specific structure having a structure represented by formula [1] (for example, the following formula [W ^1-1 ] to formula [W ^1-12 ] at least one structure selected from the group consisting of compounds represented by).

[Formula 27]

However, it is not necessarily necessary for all of W ¹ to have a structure corresponding to the above diamine. A part of W ¹ may contain a structure corresponding to diamines other than the above diamines (other diamines). As the structure corresponding to other diamines (hereinafter referred to as “structure W ² ”), it can be generalized as shown by the following formula [6]. Moreover, as A1 and A2 in following formula [ ⁶ ], the same thing as Formula [ ⁴ ] is mentioned.

[Formula 28]

Moreover, if the structure W2 represented by formula [6] is illustrated, it is as showing by the following formula [W ^2-1 ] - formula [W ^{2-173 ]} .

[Formula 29]

[Formula 30]

[Formula 31]

[Formula 32]

[Formula 33]

[Formula 34]

[Formula 35]

[Formula 36]

[Formula 37]

[Formula 38]

[Formula 39]

[Formula 40]

[Formula 41]

[Formula 42]

[Formula 43]

[Formula 44]

[Formula 45]

[Formula 46]

[Formula 47]

[Formula 48]

In addition, the Boc group in the formula [W ² -168], the formula [W ² -169], the formula [W ² -172] and the formula [W ² -173] represents a tert-butoxycarbonyl group shown below. Hereinafter, in the specification, the tert-butoxycarbonyl group is also referred to as a Boc group.

[Formula 49]

When the polyimide precursor containing the structural unit represented by Formula [4] simultaneously contains the structural unit represented by Formula [6], the structural unit represented by Formula [4] is Formula [4] and Formula [6] It is preferably 10 mol% or more relative to the total, more preferably 20 mol% or more, and particularly preferably 30 mol% or more.

When a liquid crystal aligning film is obtained from the liquid crystal aligning agent containing the said polymer, the molecular weight of the polyimide precursor or polyimide which is a polymer contained in the liquid crystal aligning agent of this invention, the intensity|strength of the coating film (liquid crystal alignment film), at the time of coating film formation Considering workability and uniformity of the coating film, the weight average molecular weight measured by GPC (Gel Permeation Chromatography) is preferably 2,000 to 500,000, more preferably 5,000 to 300,000, and still more preferably 10,000 to 100,000 Do.

<Method for producing polymer>

Next, the main manufacturing method of the polymer contained in the liquid crystal aligning agent of this invention is demonstrated. In addition, the method demonstrated below is a manufacturing example, and is not limited to this.

For example, when the polymer containing the structural unit represented by Formula [4] is a polyamic acid which is a polyimide precursor, this polymer reacts tetracarboxylic dianhydride which is a tetracarboxylic acid derivative, and a diamine component. is obtained by When obtaining a polyamic acid by this reaction, a well-known synthetic method can be used. The synthesis method is a method of reacting tetracarboxylic dianhydride and a diamine component in an organic solvent. This method is advantageous in that it proceeds relatively easily in an organic solvent and does not generate by-products.

The organic solvent used in the reaction is not particularly limited as long as it dissolves the polyamic acid (polymer) produced, and examples thereof include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl- 2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, isopropyl alcohol, Methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cell Rosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol- tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether , Dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methyl Toxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butylate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, dioxane, n-hexane , n-pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, Ethyl pyruvate, 3-methoxymethylpropionate, 3-ethoxymethylethylpropionate, 3-methoxyethylpropionate, 3-ethoxypropionate, 3-methoxypropionate, 3-methoxypropylpropionate, 3-methoxybutylpropionate , diglyme, 4-hydroxy- 4-methyl-2-pentanone, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, etc. can These may be used individually or may be mixed and used. Moreover, even if it is a solvent which does not dissolve polyamic acid (polymer), you may mix with the said organic solvent and use it in the range in which the polyamic acid produced|generated does not precipitate. In particular, moisture in the organic solvent inhibits the polymerization reaction and consequently causes the produced polyamic acid to hydrolyze. Therefore, it is preferable to use a dehydrated organic solvent as much as possible.

When the tetracarboxylic dianhydride and the diamine component are reacted in an organic solvent, a solution in which the diamine component is dispersed or dissolved in the organic solvent is stirred, and the tetracarboxylic dianhydride is added as it is or after being dispersed or dissolved in the organic solvent. method, a method of adding a diamine component to a solution obtained by dispersing or dissolving tetracarboxylic dianhydride in an organic solvent, a method of adding tetracarboxylic dianhydride and a diamine component alternately, and the like, any of which method can be used. Moreover, when the tetracarboxylic dianhydride or diamine component consists of plural kinds of compounds, they may be reacted in a state of mixing beforehand, or they may be reacted sequentially individually, or a mixture reaction of low molecular weight substances reacted separately and high molecular weight substances may be performed. can be done with

The polycondensation temperature at that time can be selected from an arbitrary temperature of -20°C to 150°C, but is preferably in the range of -5°C to 100°C. Further, the polycondensation reaction can be carried out at any concentration. However, if the concentration is too low, it becomes difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution becomes too high and uniform stirring becomes difficult. The total concentration of the carboxylic acid dianhydride and the diamine component in the reaction solution is preferably 1% by mass to 50% by mass, more preferably 5% by mass to 30% by mass. The initial stage of the reaction may be performed at a high concentration, and then an organic solvent may be added.

In the polymerization reaction of the polyamic acid, the ratio of the total number of moles of the tetracarboxylic dianhydride to the total number of moles of the diamine component (the total number of moles of the tetracarboxylic dianhydride/the total number of moles of the diamine component) is preferably from 0.8 to 1.2. . Similar to a typical polycondensation reaction, the closer this molar ratio is to 1.0, the higher the molecular weight of the polyamic acid produced.

In the case where the polymer containing the structural unit represented by formula [4] is a polyamic acid ester, the reaction between the tetracarboxylic acid diester dichloride and the diamine component, and the appropriate condensing agent and base for the tetracarboxylic acid diester and the diamine component. It can be obtained by reacting in the presence. Alternatively, it can also be obtained by synthesizing a polyamic acid in advance by the above method and esterifying the carboxylic acid in the amic acid using a polymer reaction.

Specifically, for example, tetracarboxylic diester dichloride and diamine are -20°C to 150°C, preferably 0°C to 50°C, in the presence of a base and an organic solvent for 30 minutes to 24 hours, Polyamic acid ester is synthesize|combined by making it react preferably for 1 hour - 4 hours.

As the base, pyridine, triethylamine, 4-dimethylaminopyridine and the like can be used, but pyridine is preferred because the reaction proceeds mildly. It is preferable that the addition amount of a base is 2-4 times mole with respect to tetracarboxylic-acid diester dichloride from a viewpoint that removal is easy and a high molecular weight body is easy to obtain.

In the case of polycondensation of a tetracarboxylic diester and a diamine component in the presence of a condensing agent, triphenylphosphite, dicyclohexylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodii as a base are used. Mead hydrochloride, N,N'-carbonyldiimidazole, dimethoxy-1,3,5-triazinylmethylmorpholinium, O-(benzotriazol-1-yl)-N,N,N',N '-Tetramethyluronium tetrafluoroborate, O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, (2,3-dihydro- 2-thioxo-3-benzooxazolyl)phosphonic acid diphenyl, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)4-methoxymorpholinium chloride n-hydrate etc. can be used.

Moreover, in the method using the said condensing agent, reaction advances efficiently by adding a Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferable. It is preferable that the addition amount of Lewis acid is 0.1 times mole amount - 1.0 times mole amount with respect to the diamine or tetracarboxylic diester to be reacted.

The solvent used in the reaction can be the same solvent as the solvent used when synthesizing the polyamic acid shown above, but from the solubility of the monomer and polymer, N-methyl-2-pyrrolidone and γ-butyrolactone These are preferable, and you may use these 1 type or in mixture of 2 or more types. The concentration at the time of synthesis is determined in a reaction solution of a tetracarboxylic acid derivative such as tetracarboxylic acid diester dichloride or tetracarboxylic acid diester and a diamine component from the viewpoint that precipitation of a polymer is difficult to occur and a high molecular weight material is easy to obtain. The total concentration of is preferably from 1% by mass to 30% by mass, and more preferably from 5% by mass to 20% by mass. In addition, in order to prevent hydrolysis of tetracarboxylic acid diester dichloride, it is preferable that the solvent used for the synthesis of polyamic acid ester is dehydrated as much as possible, and it is preferable to prevent mixing of outside air in a nitrogen atmosphere.

In the case where the polymer containing the structural unit represented by formula [4] is a polyimide, it has a divalent group represented by formula [1] or formula [2] in its main chain, and is obtained by subjecting the polyamic acid to dehydration ring closure . In this polyimide, the dehydration ring closure rate (imidization rate) of the amide acid group does not necessarily need to be 100%, and can be arbitrarily adjusted depending on the use or purpose.

As a method of imidating a polyamic acid, thermal imidation in which a solution of a polyamic acid is heated as it is, catalyst imidation in which a catalyst is added to a solution of a polyamic acid, and the like are exemplified.

The temperature in the case of thermal imidation of the polyamic acid in the solution is 100 ° C. to 400 ° C., preferably 120 ° C. to 250 ° C., and it is preferable to carry out while removing water generated by the imidation reaction to the outside of the system.

The catalyst imidation of the polyamic acid can be performed by adding a basic catalyst and an acid anhydride to a solution of the polyamic acid and stirring at -20°C to 250°C, preferably 0°C to 180°C. The amount of the basic catalyst is 0.5 to 30 times by mole, preferably 2 to 20 times by mole of the amide acid group, and the amount of the acid anhydride is 1 to 50 times by mole, preferably 3 to 30 times by mole of the amide acid group. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like, and among these, pyridine is preferable because it has appropriate basicity for advancing the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like, and among these, acetic anhydride is preferable because purification after completion of the reaction becomes easy. The imidation rate by catalyst imidation is controllable by adjusting the catalyst amount, reaction temperature, and reaction time.

Moreover, as mentioned above, a polyimide can be obtained also by heating polyamic acid ester at high temperature, promoting dealcoholization, and making ring closure.

In addition, when recovering the produced polyamic acid, polyamic acid ester, or polyimide from a polyimide precursor such as polyamic acid or polyamic acid ester or a polyimide reaction solution, the reaction solution may be put into a poor solvent to precipitate. . Methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, water etc. are mentioned as a poor solvent used for precipitation. The polyimide precursor or polyimide precipitated by being injected into a poor solvent can be collected by filtration and then dried by heating or at room temperature under normal pressure or reduced pressure. In addition, when the polyimide precursor or polyimide recovered by precipitation 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 this time include alcohols, ketones, hydrocarbons, and the like, and it is preferable to use three or more types of poor solvents selected from among these because the efficiency of purification is further increased.

The polymer of the present invention obtained in this way can be dissolved in a predetermined organic solvent and used as a liquid crystal aligning agent. This liquid crystal aligning agent is used for the liquid crystal aligning film which controls the orientation of the liquid crystal molecules of a liquid crystal layer in a liquid crystal display element. Hereinafter, the liquid crystal aligning agent containing the polymer of this invention is demonstrated.

<liquid crystal aligning agent>

The liquid crystal aligning agent of this invention contains the polymer obtained from the diamine component containing the diamine which has a structure shown by Formula [1] derived from the said diamine component. Moreover, it is preferable that this liquid crystal aligning agent contains the polymer which has a structure represented by Formula [2] derived from the said diamine component. Moreover, it is preferable that this polymer is at least 1 sort(s) chosen from the polyimide which is the polyimide precursor containing the structural unit represented by said Formula [4], and its imide compound.

However, the polymer contained in the liquid crystal aligning agent of the present invention may be all polymers of the present invention, and two or more types of different structures among the polymers of the present invention are exhibited to the extent of exhibiting the effect described in the present invention. may contain Or in addition to the polymer of this invention, you may contain the polymer which does not have a bivalent group represented by another polymer, ie, formula [1] or formula [2]. Examples of other polymers include polyamic acid, polyimide, polyamic acid ester, polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivative, polyacetal, polystyrene or its derivative, poly(styrene-phenylmaleimide) Derivatives, poly(meth)acrylate, etc. are mentioned.

When the liquid crystal aligning agent of this invention contains other polymers, it is preferable that the ratio of the polymer of this invention with respect to all polymer components is 5 mass % or more, and 5 mass % - 95 mass % are mentioned as the example. The ratio of the polymer of this invention can be selected suitably according to the characteristic of a liquid crystal aligning agent or a liquid crystal aligning film.

The liquid crystal aligning agent of this invention is used in order to produce a liquid crystal aligning film, and generally takes the form of a coating liquid from a viewpoint of forming a uniform thin film. Also in the liquid crystal aligning agent of this invention, it is preferable that it is a coating liquid containing said polymer component and the organic solvent which dissolves this polymer component. In that case, the concentration of the polymer in the liquid crystal aligning agent can be appropriately changed according to the setting of the thickness of the coating film to be formed. It is preferably 1% by mass or more from the point of forming a uniform and defect-free coating film, and from the point of storage stability of the solution, it is preferably set to 10% by mass or less. A particularly preferable concentration of the polymer is 2% by mass to 8% by mass.

The organic solvent contained in the liquid crystal aligning agent of this invention is not specifically limited if it is an organic solvent which dissolves a polymer. Specific examples thereof include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethylsulfoxide, and γ-butyrolactone. , 1,3-dimethyl-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, and the like. Especially, it is preferable to use N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and (gamma)-butyrolactone. In addition, the organic solvent illustrated here may be used independently or may be used in mixture. In addition, even if it is a solvent that does not dissolve the polymer, you may mix it with an organic solvent and use it to the extent that the produced|generated polymer does not precipitate.

In addition, as the organic solvent contained in the liquid crystal aligning agent, in addition to the above solvents, it is common to use a mixed solvent in which a solvent that improves the coatability at the time of applying the liquid crystal aligning agent or the surface smoothness of the coating film is used in combination, Also in the liquid crystal aligning agent of this invention, such a mixed solvent is used preferably. Although the specific example of the organic solvent used together is given below, it is not limited to these examples.

For example, ethanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, Isopentyl 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-methyl Cyclohexanol, 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 dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentane one, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, 3-ethoxybutyl acetate, 1- Methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, 2-(methoxymethoxy)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 mono Methyl 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 , diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol mono Ethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, 3-methoxymethyl propionate, 3-ethoxymethyl ethylpropionate, 3- Ethyl methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxypropylpropionate, 3-methoxybutylpropionate, methyl lactate ester, ethyl lactate ester, n-propyl lactate ester, n-butyl lactate ester , Solvents, such as isoamyl lactate, are mentioned.

Moreover, other than the solvent mentioned above, the solvent represented by following formula [S-1] - formula [S-3], for example can be used.

[Formula 50]

In the formula [S-1] and the formula [S-2], R ²⁸ and R ²⁹ represent an alkyl group having 1 to 3 carbon atoms. As a C1-C3 alkyl group, a methyl group, an ethyl group, n-propyl group, an isopropyl group etc. are mentioned, for example. Moreover, in formula [S-3], R< ³⁰ > represents a C1-C4 alkyl group. Examples of the alkyl group having 1 to 4 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl and the like. there is.

Among organic solvents used in combination, 1-hexanol, cyclohexanol, 1,2-ethanediol, 1,2-propanediol, propylene glycol monobutyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl -2-pentanone, ethylene glycol monobutyl ether or dipropylene glycol dimethyl ether is preferably used. The type and content of such a solvent are appropriately selected depending on the application device, application conditions, and application environment of the liquid crystal aligning agent.

Moreover, it is preferable that these solvents are 20 mass % - 99 mass % of the whole solvent contained in a liquid crystal aligning agent. Especially, 20 mass % - 90 mass % are preferable. More preferably, they are 20 mass % - 70 mass %.

The liquid crystal aligning agent of this invention may further contain components other than a polymer component and an organic solvent in the range which does not impair the effect of this invention. As such additional components, an adhesion auxiliary agent for enhancing the adhesion between the liquid crystal alignment film and the substrate or the adhesion between the liquid crystal alignment film and the sealing material, a crosslinking agent for increasing the strength of the liquid crystal alignment film, and a dielectric or conductive material for adjusting the dielectric constant or electrical resistance of the liquid crystal alignment film. etc. can be mentioned. Specific examples of these additional components are as disclosed in various known literatures related to liquid crystal aligning agents, but if the example is shown, it is disclosed in International Publication No. 2015/060357, paragraphs [0105] to [0116]. Ingredients and the like can be mentioned.

<Liquid crystal alignment film>

The liquid crystal aligning film of this invention is obtained from the liquid crystal aligning agent mentioned above. As an example of a method of obtaining a liquid crystal aligning film from a liquid crystal aligning agent, a method in which a liquid crystal aligning agent in the form of a coating liquid is applied to a substrate, dried, and fired, and the resulting film is subjected to alignment treatment by a rubbing treatment method or a photo-alignment treatment method. can be heard

The substrate to which the liquid crystal aligning agent of the present invention is coated is not particularly limited as long as it is a substrate having high transparency, and plastic substrates such as acrylic substrates and polycarbonate substrates may be used together with glass substrates and silicon nitride substrates. At that time, it is preferable to use a substrate having an ITO electrode or the like for driving the liquid crystal in view of simplifying the process. In addition, as for the reflective liquid crystal display element, an opaque one such as a silicon wafer can be used as long as it is only a substrate on one side, and a material that reflects light such as aluminum can also be used for the electrode in this case.

Although the application|coating method of a liquid crystal aligning agent is not specifically limited, Industrially, screen printing, offset printing, flexographic printing, an inkjet method, etc. are common. Other coating methods include a dip method, a roll coater method, a slit coater method, a spinner method, and a spray method, and these may be used depending on the purpose.

Baking after applying the liquid crystal aligning agent on the substrate is carried out at 50 ° C. to 300 ° C., preferably 80 ° C. to 250 ° C. by heating means such as a hot plate, a hot air circulation furnace, an infrared furnace, and the solvent is evaporated, A coating film (liquid crystal alignment film) can be formed. If the thickness of the coating film formed after firing is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may decrease. Therefore, it is preferably 5 nm to 300 nm, more preferably Preferably, it is 10 nm to 100 nm. When horizontally aligning or tilting a liquid crystal, the coating film after baking is treated by rubbing or polarized light ultraviolet irradiation.

After the liquid crystal aligning agent is applied on the substrate, the solvent is evaporated and fired by a heating means such as a hot plate, a heat circulation oven, or an IR (infrared ray) oven. The drying and baking process after apply|coating a liquid crystal aligning agent can select arbitrary temperature and time. Usually, in order to sufficiently remove the contained solvent, the conditions of baking at 50°C to 120°C for 1 minute to 10 minutes, and then baking at 150°C to 300°C for 5 minutes to 120 minutes are exemplified.

The liquid crystal aligning film of the present invention is suitable as a liquid crystal aligning film of a liquid crystal display element of a horizontal electric field system such as an IPS system or a FFS system, and is particularly useful as a liquid crystal alignment film of a liquid crystal display element of an FFS system.

<Liquid crystal display element>

After the liquid crystal display element of this invention is equipped with the above-mentioned liquid crystal aligning film, and obtained the board|substrate with a liquid crystal aligning film obtained from the above-mentioned liquid crystal aligning agent, it produced a liquid crystal cell by a known method, and used the liquid crystal cell. So it was made small. As an example, a liquid crystal display comprising two substrates arranged to face each other, a liquid crystal layer formed between the substrates, and a liquid crystal cell having a liquid crystal alignment film formed between the substrate and the liquid crystal layer and formed of the liquid crystal aligning agent of the present invention. it is small

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

Moreover, a liquid crystal aligning film is formed by baking, after apply|coating the liquid crystal aligning agent of this invention on this board|substrate, and is as having mentioned above in detail.

The liquid crystal material constituting the liquid crystal layer of the liquid crystal display element of the present invention is not particularly limited, and includes nematic liquid crystals and smectic liquid crystals. Among them, nematic liquid crystals are preferable, and positive liquid crystal materials and negative liquid crystal materials are used. Any of these may be used. Specifically, for example, MLC-2003, MLC-6608, MLC-6609, MLC-3019, MLC-2041, MLC-7026-100 manufactured by Merck, etc. can be used.

Specifically, a transparent glass substrate is prepared, and a common electrode is formed on one substrate and a segment electrode is formed on the other substrate. These electrodes can be, for example, ITO electrodes, and are patterned so that desired image display can be performed. Next, an insulating film is formed on each substrate so as to cover the common electrode and the segment electrode. The insulating film can be, for example, a film made of SiO ₂ -TiO ₂ formed by a sol-gel method. Next, a liquid crystal aligning film is formed on each board|substrate on conditions similar to the above.

Then, after arrange|positioning the ultraviolet curable sealing material in the predetermined place on one board|substrate of the two board|substrates on which the liquid crystal aligning film was formed, and arrange|positioning the liquid crystal at the predetermined resin point on the surface of the liquid crystal aligning film, the liquid crystal aligning film opposes After spreading the liquid crystal on the front surface of the liquid crystal aligning film by bonding the other substrate together and crimping so as to do so, the entire surface of the substrate is irradiated with ultraviolet rays and the sealing material is cured to obtain a liquid crystal cell.

Or, as a step after forming a liquid crystal alignment film on a substrate, when arranging a sealant at a predetermined place on one substrate, forming an opening capable of filling liquid crystal from the outside, and bonding the substrate together without disposing the liquid crystal , A liquid crystal material is injected into a liquid crystal cell through an opening formed in a sealing material, and then the opening is sealed with an adhesive to obtain a liquid crystal cell. Injecting the liquid crystal material may be a vacuum injection method or a method using capillarity in the air.

In any of the above methods, in order to secure a space in which the liquid crystal material is filled in the liquid crystal cell, a columnar projection is formed on one substrate, a spacer is spread on one substrate, a spacer is mixed with a sealing material, Alternatively, it is preferable to take measures such as combining them.

Next, the polarizing plate is installed. Specifically, it is preferable to attach a pair of polarizing plates to the surfaces of the two substrates opposite to the liquid crystal layer.

In addition, as long as the liquid crystal aligning film and liquid crystal display element of this invention are using the liquid crystal aligning agent of this invention, it is not limited to the said base material, What was produced by another well-known method may be sufficient as it. Steps from the liquid crystal aligning agent to obtaining the liquid crystal display element are disclosed in, for example, paragraphs [0074] to [0081] of Unexamined-Japanese-Patent No. 2015-135393, as well as numerous literatures.

As mentioned above, the liquid crystal display element produced using the liquid crystal aligning agent of this invention becomes a thing excellent in reliability, and can be used suitably for a large-screen, high-definition liquid crystal television etc.

Example

The present invention will be specifically described below with examples and the like. In addition, this invention is not limited to these Examples.

The symbol of the compound used below and the method of characteristic evaluation are as follows.

[Formula 51]

[Formula 52]

<organic solvent>

NMP: N-methyl-2-pyrrolidone

NEP: N-ethyl-2-pyrrolidone

GBL: γ-butyrolactone

BCS: butyl cellosolve

PB: propylene glycol monobutyl ether

DME: Dipropylene glycol dimethyl ether

DAA: 4-hydroxy-4-methyl-2-pentanone

DEDG: Diethylene glycol diethyl ether

DIBK: 2,6-dimethyl-4-heptanone

DIPE: diisopropyl ether

DIBC: 2,6-dimethyl-4-heptanol

Pd/C: Palladium carbon

DMSO: Dimethylsulfoxide

THF: tetrahydrofuran

＜Additives＞

LS-4668 : 3-glycidoxypropyltriethoxysilane

(Measurement of ¹ H-NMR)

Device: Varian NMR system 400NB (400 MHz) (manufactured by Varian), and JMTC-500/54/SS (500 MHz) (manufactured by JEOL)

Measurement solvent: CDCl ₃ (deuterated chloroform), DMSO-d ₆ (deuterated dimethyl sulfoxide)

Reference materials: TMS (tetramethylsilane) (δ: 0.0 ppm, ¹ H) and CDCl ₃ (δ: 77.0 ppm, ¹³ C)

<Synthesis of diamine compound (DA-1)>

[Formula 53]

In a 2 L (liter) four-necked flask, 2,5-dibromothiophene (50 g, 208 mmol), 4-nitrophenylboronic acid (72.9 g, 436 mmol), sodium carbonate (110 g, 1040 mmol), dimethyl Formamide (500 g) and pure water (100 g) were injected. Thereafter, tetrakistriphenylphosphine palladium (2.5 g) was added at room temperature in a nitrogen atmosphere, the temperature was raised to 100°C, and the mixture was stirred for 48 hours. After confirming completion of the reaction by HPLC (high performance liquid chromatography), the obtained solid was filtered under reduced pressure, and repulp washing was performed with pure water (500 g). The precipitated crystals were filtered under reduced pressure, repulped and washed with acetonitrile (350 g) at 80°C, and then dried to obtain powder crystals (1) (amount 42 g, yield 50%).

The NMR measurement results are as follows.

[Formula 54]

A mixture of compound (1) (20 g, 61.3 mmol), 5 mass% Pt/C (50% water-containing), characteristic white activated carbon (2.0 g), and dioxane (100 g) was heated at 80°C under hydrogen pressure conditions. Stir for 24 hours. After completion of the reaction, the catalyst was filtered and concentrated to dryness. After recrystallizing the obtained solid from ethyl acetate (200 g) and toluene (200 g), the precipitated crystals were filtered under reduced pressure, washed with methanol (50 g), and then dried to obtain powder crystal DA-1 (amount 8 g, yield 50%).

The NMR measurement results are as follows.

<Synthesis of diamine compound (DA-2)>

[Formula 55]

Zinc chloride (120.3 g, 882 mmol) was added to a 3 L (liter) four-necked flask, the temperature was raised to 100°C, and vacuum drying was performed with an oil pump for 1 hour. Then, under a nitrogen atmosphere, at room temperature, toluene (460 g), diethylamine (45.0 g, 615 mmol), t-butanol (46.4 g, 626 mmol), 2-bromo-4-nitroacetophenone (100.0 g, 410 mmol) and 4-nitroacetophenone (104.2 g, 631 mmol) were sequentially added, and the mixture was stirred at room temperature for 3 days. After confirming completion of the reaction by HPLC (high performance liquid chromatography), a 5% aqueous solution of sulfuric acid (400 g) was added to neutralize the mixture, and the mixture was stirred at room temperature for 1 hour. The precipitated crystals were filtered under reduced pressure, washed with toluene (200 g), pure water (300 g) and methanol (200 g), then dried to obtain crude crystals. The obtained crude crystal was entirely dissolved in tetrahydrofuran (1340 g) at 60°C, then ethanol (1340 g) was added and the mixture was stirred at 5°C for 1 hour. The precipitated crystals were filtered under reduced pressure, washed with ethanol (200 g), and then dried to obtain powdered crystals (1) (amount 63 g, yield 45%).

The NMR measurement results are as follows.

[Formula 56]

Compound (1) (50 g, 152 mmol) and acetic anhydride (1000 g) were charged into a 2 L (liter) four-necked flask, and sulfuric acid (10 g) and acetic anhydride (200 g) were added dropwise. After completion of the dropwise addition, the temperature was raised to 140°C, and the mixture was stirred for 3 hours. After confirming the completion of the reaction by HPLC (high performance liquid chromatography), the reaction solution was added to cold water (5000 g) and stirred for 1 hour. The precipitated crystals were filtered under reduced pressure, repulped and washed with acetonitrile (500 g) at 80°C, and then dried to obtain powder crystals (2) (amount 42 g, yield 90%).

The NMR measurement results are as follows.

[Formula 57]

A mixture of compound (2) (40 g, 129 mmol), 5 mass% Pt/C (50% functional), characteristic white activated carbon (4.0 g), and tetrahydrofuran (400 g) was heated at 60°C under hydrogen pressure conditions. was stirred for 12 hours. After completion of the reaction, the catalyst was filtered and concentrated to dryness. After recrystallizing the obtained solid from acetonitrile (400 g), the precipitated crystals were filtered under reduced pressure, washed with methanol (50 g), and dried to obtain powder crystal DA-2 (amount 20 g, yield 77%) .

The NMR measurement results are as follows.

[Synthesis Example 1]

After adding DA-1 (1.60 g, 6.0 mmol) and DA-4 (0.79 g, 4.0 mmol) to a 100 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, NMP:GBL = 1:1 mixing 24.0 g of solvent was added, and it was stirred and dissolved while blowing nitrogen. While stirring this solution, CA-1 (0.87 g, 4.0 mmol), CA-2 (1.04 g, 5.3 mmol), and 8 g of NMP:GBL = 1:1 mixed solvent were added, and then 50 A polyamic acid solution (PAA-A1) was obtained by stirring under °C conditions for 12 hours.

[Synthesis Examples 2 to 7]

Polyamic acid solution shown in Table 1 by carrying out in the same manner as in Synthesis Example 1, except that the diamine component, tetracarboxylic acid component, and solvent shown in Table 1 were used and the reaction temperatures shown in Table 1 were respectively used ( PAA-A2) to (PAA-A4) and polyamic acid solution (PAA-B1) to (PAA-B3) were obtained.

[Table 1]

[Synthesis Example 8]

DA-6 (4.03 g, 16.5 mmol), DA-7 (3.59 g, 9.0 mmol), and DA-8 (2.51 g, 4.5 mmol) were placed in a 200 ml four-necked flask equipped with a stirrer and a nitrogen inlet tube. After addition, 74.0 g of NMP was added, and it was stirred and dissolved while blowing nitrogen. While stirring this solution, CA-3 (4.37 g, 19.5 mmol) and 9.0 g of NMP were added, and it stirred under 40 degreeC conditions for 3 hours. Then, after adding CA-2 (1.71g, 8.7mmol) and 9.0g of NMP on 25 degreeC conditions, the polyamic-acid solution was obtained by further stirring for 12 hours. The viscosity in the temperature of 25 degreeC of this polyamic acid solution was 480 mPa*s. Moreover, the molecular weight of this polyamic acid was Mn = 10,660 and Mw = 20,512.

After fractionating 80.0g of this polyamic acid solution and adding 20.0g of NMP, 6.8g of acetic anhydride and 1.8g of pyridine were added, and it was made to react at 50 degreeC for 3 hours. This reaction solution was injected into 434.4 g of methanol while stirring, and the deposited 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 imidation rate of this polyimide was 75%. A polyimide solution (SPI-B4) was obtained by adding 80.0 g of NMP to 20.0 g of the obtained polyimide powder, stirring at 70°C for 20 hr, and dissolving.

[Examples 1 to 19] and [Comparative Examples 1 to 4]

Solvents and additives are stirred so that the polyamic acid solutions obtained in Synthesis Examples 1 to 7 and the polyimide solutions obtained in Synthesis Example 8 may become compositions shown in the solvent Table 2-1 and Table 2-2 in the liquid crystal aligning agent obtained. A liquid crystal aligning agent was obtained by adding and further stirring at room temperature for 2 hours.

[Table 2-1]

[Table 2-2]

<Production of liquid crystal display element by rubbing method>

A glass substrate having a size of 30 mm × 35 mm and having an electrode having a thickness of 0.7 mm was formed. On the substrate, as a first layer, an IZO electrode comprising a counter electrode and having a solid pattern is formed. On the counter electrode of the first layer, as a second layer, a SiN (silicon nitride) film formed by the CVD method is formed. The film thickness of the second layer SiN film is 500 nm, and functions as an interlayer insulating film. A comb-shaped pixel electrode formed by patterning an IZO film as a third layer is disposed on the SiN film of the second layer, forming two pixels, a first pixel and a second pixel. The size of each pixel is 10 mm long and about 5 mm wide. 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 configured by arranging a plurality of ""-shaped electrode elements with curved central portions shown in the drawing (FIG. 3) described in Japanese Unexamined Patent Publication No. 2014-77845. The width of each electrode element in the short direction is 3 μm, and the interval between the electrode elements is 6 μm. Since the pixel electrodes constituting each pixel are constituted by arranging a plurality of z-shaped electrode elements with bent central portions, the shape of each pixel is not rectangular, but is bent at the central portion in the same way as the electrode element. It has a shape similar to the character "く" in . Then, each pixel is divided up and down with the central curved portion as a boundary, and has a first region above the curved portion and a second region below the curved portion.

Comparing the 1st area and the 2nd area|region of each pixel, the formation direction of the electrode element of the pixel electrode which comprises them differs. 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 to form an angle of +10 ° (clockwise direction) in the first area of the pixel, and the electrode of the pixel electrode in the second area of the pixel The elements are formed to form an angle of -10° (clockwise). Further, in the first area and the second area of each pixel, the direction of rotational movement (in-plane switching) within the substrate surface of liquid crystal caused by application of a voltage between the pixel electrode and the counter electrode is opposite to each other. has been

Next, after filtering the liquid crystal aligning agent with a filter of 1.0 μm, the substrate on which the electrode is formed and the glass substrate having an ITO film formed on the back side as a counter substrate and having a columnar spacer with a height of 4 μm are each spin coated did Subsequently, after drying on a hot plate at 80°C for 5 minutes, it was baked at 230°C for 20 minutes to obtain a polyimide film having a film thickness of 60 nm on each substrate. The polyimide film surface was subjected to rubbing treatment with a rayon cloth under the conditions of a roll diameter of 120 mm, a roller rotation speed of 500 rpm, a stage moving speed of 30 mm/sec, and a rubbing cloth press-in pressure of 0.3 mm, followed by ultrasonic waves in pure water for 1 minute. Irradiation was performed and it dried at 80 degreeC for 10 minutes.

Using the two types of substrates on which the liquid crystal alignment film was formed, they were combined so that the respective rubbing directions were antiparallel, and the periphery was sealed leaving the liquid crystal injection port, to prepare an empty cell having a cell gap of 3.8 μm. After vacuum injecting a liquid crystal (MLC-3019, manufactured by Merck & Co., Ltd.) into this empty cell at normal temperature, the injection port was sealed to obtain an antiparallel alignment liquid crystal cell. The obtained liquid crystal cell constitutes an FFS mode liquid crystal display element. Then, after heating the liquid crystal cell at 120 degreeC for 1 hour and leaving it to stand overnight, it used for evaluation.

<Evaluation of afterimage erasure time>

The residual image was evaluated using the following optical systems and the like. That is, the prepared liquid crystal cell was installed between two polarizing plates arranged so that the polarization axes were orthogonal, the LED backlight was turned on in a voltage-free state, and the angle of arrangement of the liquid crystal cell was adjusted so that the luminance of the transmitted light was the smallest. Next, the V-T curve (voltage-transmittance curve) was measured, applying an alternating voltage with a frequency of 30 Hz to this liquid crystal cell, and the relative transmittance calculated the alternating voltage used as 23% as a drive voltage.

In residual image evaluation, a 1V direct-current voltage was applied simultaneously and it was driven for 30 minutes, applying the alternating voltage of the frequency 30Hz used as 23 % and driving a liquid crystal cell with a relative transmittance of 23%. After that, the applied DC voltage value was set to 0 V, only the application of the DC voltage was stopped, and it was further driven in that state for 15 minutes.

For evaluation of residual image, the time when the relative transmittance decreased to 30% or less was digitized until 30 minutes had elapsed from the time when application of the DC voltage was started. When the relative transmittance fell to 30% or less within 5 minutes, it was defined as "○", and within 6 to 30 minutes as "Δ" for evaluation. When 30 minutes or more was required until the relative transmittance fell to 30% or less, afterimage removal was impossible, and it was defined as "x" for evaluation. And the residual image evaluation by the method mentioned above was performed on the temperature condition of the state whose temperature of a liquid crystal cell is 23 degreeC.

<Stability evaluation of liquid crystal orientation>

The alternating voltage of 10 VPP was applied to the produced liquid crystal cell on the frequency of 30 Hz in a 60 degreeC constant temperature environment for 168 hours. Then, it was made into the state which short-circuited between the pixel electrode of a liquid crystal cell and the counter electrode, and it was left to stand at room temperature for one day as it was.

After standing, the liquid crystal cell was installed between two polarizing plates arranged so that the polarization axes were orthogonal, the backlight was turned on in a voltage-free state, and the angle of arrangement of the liquid crystal cell was adjusted so that the luminance of the transmitted light was minimized. And the rotation angle at the time of rotating the liquid crystal cell from the angle at which the 2nd area|region of a 1st pixel becomes the darkest to the angle at which 1st area|region becomes the darkest was computed as angle (DELTA). Similarly, also in the second pixel, the second area and the first area were compared, and the same angle Δ was calculated. And the average value of the angle Δ value of the 1st pixel and the 2nd pixel was computed as angle Δ of a liquid crystal cell. It was presupposed that the stability of liquid-crystal orientation was excellent, so that the value of the angle (DELTA) of this liquid crystal cell was small.

<Evaluation of optical properties (transparency)>

A quartz substrate having a size of 40 mm × 40 mm and a thickness of 1.0 mm was prepared. Next, after filtering the liquid crystal aligning agent with a 1.0 μm filter, it was spin-coated on the quartz substrate. Subsequently, after drying on a hot plate at 80°C for 2 minutes, it was baked at 230°C for 20 minutes to obtain a polyimide film having a film thickness of 100 nm on each substrate.

Evaluation of transparency was performed by measuring the transmittance of the substrate obtained by the above method. Specifically, transmittance was measured using UV-3600 (manufactured by Shimadzu Corporation) as a measuring device, under conditions of a temperature of 25°C and a scanning wavelength of 300 nm to 800 nm. At that time, it was carried out using a quartz substrate to which nothing was coated as a reference (reference example). Evaluation computed the average transmittance of the wavelength of 450 nm - 800 nm, and the transparency was so excellent that transmittance was high.

<Evaluation result>

About the liquid crystal display element using each liquid crystal aligning agent of the said Examples 1-4 and 19 and Comparative Examples 1-4, the evaluation of the afterimage erasure time performed above, the stability evaluation of liquid-crystal orientation, and the result of transparency evaluation are shown in Table 3-1, Table 3-2 and Table 3-3.

[Table 3-1]

[Table 3-2]

[Table 3-3]

As shown in Table 3-1, the liquid crystal display element using the liquid crystal aligning agent of Examples 1 to 4 shows that the relaxation of the accumulated electric charge is quick, and the orientation and transparency are improved.

As shown in Table 3-1 and Table 3-3, the liquid crystal display element using the liquid crystal aligning agent of Examples 1 to 4 and 19 is quick to relax the stored charge, and it is found that orientation and transparency are improved. can

Claims (6)

The liquid crystal aligning agent characterized by containing the polymer obtained from the diamine component containing the diamine which has a structure represented by following formula [1], and an organic solvent.

(In formula [1], Y ¹ represents an S atom or an O atom, and * represents a site bonded to another group. In addition, an arbitrary hydrogen atom in the benzene ring may be substituted with a monovalent organic group.) According to claim 1,
A liquid crystal in which the polymer is at least one polymer selected from the group consisting of a polyimide precursor that is a polycondensate of diamine having a structure represented by the formula [1] and tetracarboxylic dianhydride, and a polyimide that is an imide thereof. orientation agent. According to claim 1,
The liquid crystal aligning agent in which the said diamine is represented by the following formula [2].

(In formula [2], the definition of Y ¹ is the same as in formula [1], R ² each independently represents a single bond or a structure of formula [3] below, and n represents an integer of 1 to 3 Arbitrary hydrogen atoms of the benzene ring may be substituted with monovalent organic groups.)

(In formula [3], R ³ is a single bond, -O-, -COO-, -OCO-, -(CH ₂ ) _l -, -O(CH ₂ ) _m O-, -CONH-, and - Represents a divalent organic group selected from NHCO- (l and m represent integers of 1 to 5), * ₁ represents a site bonding to a benzene ring in formula [2], and * ₂ represents an amino group in formula [2] Indicates the site that binds to.) According to claim 3,
The liquid crystal aligning agent characterized by being at least 1 sort(s) chosen from the polyimide whose said polymer is a polyimide precursor and its imide compound containing the structural unit represented by following formula [4], The liquid crystal aligning agent characterized by the above-mentioned.

(In formula [4], X ¹ is a tetravalent organic group derived from a tetracarboxylic acid derivative, and W ¹ is a divalent organic group derived from diamine having a structure represented by formula [2] or formula [3] R ⁴ and R ⁵ represent 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 5 carbon atoms, and an alkyl group having 2 to 5 carbon atoms. represents an alkenyl group of 5 or an alkynyl group of 2 to 5 carbon atoms.) The liquid crystal aligning film characterized by being obtained from the liquid crystal aligning agent in any one of Claims 1-4. The liquid crystal display element characterized by being equipped with the liquid crystal aligning film of Claim 5.