KR20190057141A - Diamine, polymer, liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display element - Google Patents

Abstract

(식 [1] 중, Y¹ 및 Y² 는, 각각 독립적으로 단결합, -O-, -S-, -COO- 또는 -OCO- 이고, R¹ 및 R² 는, 각각 독립적으로 -H, -OH, =O 또는 1 가의 유기기이고, R³ 및 R⁴ 는, 각각 독립적으로 탄소 원자수 1 ∼ 3 의 알킬렌기이다. 또, 벤젠 고리의 임의의 수소 원자는, 1 가의 유기기로 치환되어 있어도 된다.)Is a diamine having a structure represented by the following formula [1].

(1), Y ¹ and Y ² are each independently a single bond, -O-, -S-, -COO- or -OCO-, R ¹ and R ² are each independently -H, -OH, = O or a monovalent organic group, and R ³ and R ⁴ are each independently an alkylene group having 1 to 3 carbon atoms, and any hydrogen atom of the benzene ring is substituted with a monovalent organic group It may be.)

Description

Diamine, polymer, liquid crystal aligning agent, liquid crystal alignment 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 alignment film, and a liquid crystal display element.

Currently, liquid crystal display elements are widely used as display portions of personal computers, mobile phones, television sets, and the like. The liquid crystal display element includes, for example, a liquid crystal layer sandwiched between an element substrate and a color filter substrate, a pixel electrode and a common electrode for applying an electric field to the liquid crystal layer, a liquid crystal alignment film for controlling the orientation of liquid crystal molecules in the liquid crystal layer, And a thin film transistor (TFT) for switching an electric signal to be supplied. Of these, the liquid crystal alignment film is formed by coating a substrate with a polyimide-based liquid crystal aligning agent comprising a polyamic acid (also referred to as " polyamic acid ") which is a polyimide precursor and a solution of polyimide as an imide .

In recent years, the performance of a liquid crystal display device has been increased, the size of the liquid crystal display device has been increased, the power consumption of a display device has been reduced, and furthermore, the liquid crystal display device has been used under various circumstances. Therefore, in addition to the improvement of the liquid crystal alignability and the electrical characteristics, various pretreatments such as control of the pretilt angle and the like can be carried out by various methods such as changing the structure of polyamic acid or polyimide, blending of polyamic acid or polyimide having different characteristics, And so on.

As an example of a technique for improving the properties of a liquid crystal alignment film, application of a diamine having a novel structure, which is a raw material of polyamic acid, has been proposed. For example, Patent Document 1 discloses a liquid crystal aligning agent containing a diamine having a novel structure and an aliphatic tetracarboxylic acid derivative. By using this liquid crystal aligning agent, it is possible to provide a liquid crystal aligning agent which is excellent in voltage retention rate, A liquid crystal display element can be provided.

However, with the increase in the performance of the liquid crystal display device, the characteristics required for the liquid crystal alignment film have become stricter, and it is difficult to satisfy all the required characteristics by the conventional technology alone.

International Publication No. 2010/053128

In view of the above circumstances, it is an object of the present invention to provide a novel diamine, a polymer for use in a liquid crystal display element, a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display element for improving the properties of the liquid crystal display element .

As a result of intensive studies, the inventors of the present invention have found out that, when a polymer obtained by using a specific diamine is applied to a liquid crystal display device, the present invention is particularly effective for reducing flicker at the initial stage of driving. It came to the following. The diamine of the present invention to be described later is a novel compound not listed in the literature.

The diamine of the present invention for achieving the above object is characterized by the following formula [1].

[Chemical Formula 1]

(1), Y ¹ and Y ² are each independently a single bond, -O-, -S-, -COO- or -OCO-, R ¹ and R ² are each independently -H, -OH, = O or a monovalent organic group, and R ³ and R ⁴ are each independently an alkylene group having 1 to 3 carbon atoms, and any hydrogen atom of the benzene ring is substituted with a monovalent organic group It may be.)

The polymer of the present invention which achieves the above object is characterized by being obtained from a diamine component containing a diamine having a structure represented by the following formula [2].

(2)

(Wherein Y ¹ is a single bond, -O-, -S-, -COO- or -OCO-, R ¹ and R ² are each independently -H, -OH, = O or R ³ is an alkylene group having 1 to 3 carbon atoms, and * indicates a site bonded to another group. Further, any hydrogen atom of the benzene ring may be substituted with a monovalent organic group do.)

The polymer is preferably obtained from a diamine component containing a diamine having a structure represented by the following formula [3].

(3)

(Wherein, Y ¹ and Y ² are each independently a single bond, -O-, -S-, -COO- or -OCO-, R ¹ and R ² are each independently -H, R ³ and R ⁴ are each independently an alkylene group having 1 to 3 carbon atoms and * indicates a site bonded to another group. In addition, an arbitrary number of benzene rings May be substituted with a monovalent organic group.)

The polymer is preferably at least one member selected from a polyimide precursor containing a structural unit represented by the following formula [4] and a polyimide which is an imide compound thereof.

[Chemical Formula 4]

(In the 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 a diamine having a structure represented by the formula [2] or [3] R ⁵ and R ^{6 each} represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; A ¹ and A ² each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, An alkenyl group having 5 to 5 carbon atoms or an alkynyl group having 2 to 5 carbon atoms.

The liquid crystal aligning agent of the present invention for achieving the above object is characterized by containing a polymer and an organic solvent.

The liquid crystal alignment film of the present invention for achieving the above object is characterized by being obtained from the liquid crystal aligning agent.

The liquid crystal display element of the present invention for achieving the above object is characterized by including the liquid crystal alignment layer.

According to the present invention, it is possible to provide a novel diamine, a polymer used for a liquid crystal display element, a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display element for improving the characteristics of the liquid crystal display element.

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

<Diamine>

The diamine of the present invention is represented by the following formula [1].

[Chemical Formula 5]

(1), Y ¹ and Y ² are each independently a single bond, -O-, -S-, -COO- or -OCO-, R ¹ and R ² are each independently -H, -OH, = O or a monovalent organic group, and R ³ and R ⁴ are each independently an alkylene group having 1 to 3 carbon atoms, and any hydrogen atom of the benzene ring is substituted with a monovalent organic group It may be.)

In the formula [1], examples of the monovalent organic group include a hydrocarbon group; A hydrocarbon group containing a hydroxyl group, a carboxyl group, a hydroxyl group, a thiol group or a carboxyl group; A hydrocarbon group connected by a bonding group such as an ether bond, an ester bond or an amide bond; A hydrocarbon group containing a silicon atom; Halogenated hydrocarbon groups; An amino group; And an inert group in which the amino group is protected by a carbamate-based protecting group such as a t-butoxycarbonyl group. The hydrocarbon group may be any of a linear chain, a branched chain and a cyclic chain, and may be a saturated hydrocarbon or an unsaturated hydrocarbon. A part 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 may be connected by a bonding group such as an ether bond, an ester bond or an amide bond.

The alkylene group having 1 to 3 carbon atoms may be any of a linear chain, a branched chain and a cyclic chain. Specific examples thereof include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, a cyclopropylene group, a 1-methyl-cyclopropylene group, a 2-methyl- Propylene group, a 1-ethyl-n-propylene group, a 1,2-dimethyl-cyclopropylene group, a 2,3-dimethyl-cyclopropylene group , 1-ethyl-cyclopropylene group, 2-ethyl-cyclopropylene group, 1,1,2-trimethyl-n-propylene group, 1,2,2- propylene group, a 2-isopropyl-cyclopropylene group, a 2-isopropyl-cyclopropylene group, a 1,2-propylene group, , 2-trimethyl-cyclopropylene group, 1,2,3-trimethyl-cyclopropylene group, 2,2,3-trimethyl-cyclopropylene group, Methyl-cyclopropylene group, 2-ethyl-2-methyl-cyclopropyl And 2-ethyl-3-methyl-cyclopropylene group.

In addition, monovalent organic groups and alkylene groups having 1 to 3 carbon atoms can be selected in various ways depending on the use.

Specific examples of the diamine represented by the formula [1] include, but are not limited to, diamines represented by the following formulas [5-1] to [5-13].

[Chemical Formula 6]

In the formula [5-3], Boc represents a group (tert-butoxycarbonyl group) shown below.

(7)

<Synthesis method of diamine>

Next, the main synthesis method of the diamine of the present invention will be described. In addition, the method described below is a synthetic example and is not limited thereto.

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

[Chemical Formula 8]

(Wherein Y ¹ and Y ² are each independently a single bond, -O-, -S-, -COO- or -OCO-, R ¹ and R ² are each independently -H, -OH , = O or a monovalent organic group, and R ³ and R ⁴ each independently represent an alkylene group having 1 to 3 carbon atoms, and any hydrogen atom of the benzene ring may be substituted with a monovalent organic group .)

The method for reducing the dinitro compound is not particularly limited and may be carried out by using palladium-carbon, platinum oxide, Raney nickel, platinum black, rhodium-alumina, platinum sulfide carbon or the like as a catalyst and using ethyl acetate, toluene, tetrahydrofuran, Oxalic acid, or an alcoholic solvent, hydrogen gas, hydrazine, hydrogen chloride, or the like. And may be carried out under pressure using an autoclave or the like as occasion demands. On the other hand, when the substituent substituting the hydrogen atom of the benzene ring or the saturated hydrocarbon moiety includes an unsaturated bond moiety in the structure, if the palladium carbon or the platinum carbon is used, the unsaturated bond moiety may be reduced and become saturated bond Therefore, a reducing condition using a transition metal such as reduced iron, tin or tin chloride as a catalyst is preferable.

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 is capable of being synthesized, and examples thereof include inorganic bases such as potassium carbonate, sodium carbonate, cesium carbonate, sodium alkoxide, potassium alkoxide, sodium hydroxide, potassium hydroxide and sodium hydride, pyridine, dimethylaminopyridine, And organic bases such as triethylamine, tributylamine and the like. In some cases, a palladium catalyst such as dibenzylidene acetone palladium or diphenylphosphinoferrocene palladium or a copper catalyst may be used in combination to improve the yield.

The thus obtained diamine of the present invention can be used as a raw material for a polyimide precursor such as polyamic acid or polyamic acid ester, a polyimide, a polyurea, a polyamide, etc. (collectively referred to as &quot; polymer &quot;). The polymer can be used, for example, as a liquid crystal aligning agent by dissolving in a predetermined organic solvent, but is not limited thereto. Hereinafter, a polymer containing a diamine represented by the formula [1] will be described in the structure.

<Polymer>

The polymer of the present invention is obtained by using the above-described diamine of the present invention or a derivative thereof (to be described later), and has a structure represented by the following formula [2] derived from a diamine component.

[Chemical Formula 9]

(Wherein Y ¹ is a single bond, -O-, -S-, -COO- or -OCO-, R ¹ and R ² are each independently -H, -OH, = O or R ³ is an alkylene group having 1 to 3 carbon atoms, and * indicates a site bonded to another group. Further, any hydrogen atom of the benzene ring may be substituted with a monovalent organic group do.)

The structure represented by the formula [2] derived from the diamine component of such a polymer preferably has a structure represented by the following formula [3].

[Chemical formula 10]

(Wherein, Y ¹ and Y ² are each independently a single bond, -O-, -S-, -COO- or -OCO-, R ¹ and R ² are each independently -H, R ³ and R ⁴ are each independently an alkylene group having 1 to 3 carbon atoms and * indicates a site bonded to another group. In addition, an arbitrary number of benzene rings May be substituted with a monovalent organic group.)

The derivative of the diamine of the present invention may be a structure in which two or more diamines are linked to each other or a diamine having a structure in which the diamine is linked via Y ¹ or Y ² . The structure derived from the diamine component may contain a structure derived from another diamine (described later) in addition to the structure represented by the formula [2].

Examples of the monovalent organic group and the alkylene group having 1 to 3 carbon atoms in the formulas [2] and [3] include the same ones as the formula [1].

From the viewpoint of use as a liquid crystal aligning agent, the polymer of the present invention is preferably at least one selected from a polyimide precursor containing a structural unit represented by the following formula [4] and a polyimide which is an imide compound thereof.

(11)

(In the 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 a diamine having a structure represented by the formula [2] or [3] R ⁵ and R ^{6 each} represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; A ¹ and A ² each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, An alkenyl group having 5 to 5 carbon atoms or an alkynyl group having 2 to 5 carbon atoms.

Examples of the alkyl group having 1 to 5 carbon atoms in the formula [4] include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n- butyl group, an isobutyl group, Pentyl group, and t-pentyl group. Examples of the alkenyl group having 2 to 5 carbon atoms include a vinyl group, an allyl group, a 1-propenyl group, a 1- Butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl and 4-pentenyl. Examples of the alkynyl group having 2 to 5 carbon atoms include, For example, an ethynyl group, a 1-propynyl group, a 2-propynyl (propargyl) group, a 3-butynyl group and a pentynyl group. In view of the progress ease of imidization reaction during Among these, heating, R ⁵ and R ⁶ are in terms of a hydrogen atom, a methyl group or an ethyl group is preferable, and a hydrogen atom or a methyl group, more preferred, and the liquid crystal alignment property, A ¹ and A ² is preferably a hydrogen atom or a methyl group.

When X ¹ is a tetravalent organic group derived from a tetracarboxylic acid derivative, its structure is not particularly limited. X ¹ is suitably selected according to the degree of the required properties such as the solubility of the polymer in a solvent, the application of the liquid crystal aligning agent, the orientation of the liquid crystal in the case of a liquid crystal alignment film, the voltage retention rate, , One type of the same polymer or two types or more of them may be mixed.

X ¹ represents a tetracarboxylic acid dihalide compound, a tetracarboxylic acid dialkyl ester compound, or a tetracarboxylic acid dialkyl ester dihalide compound, which is a tetracarboxylic acid derivative, as well as a tetracarboxylic acid dianhydride, It can also be used. As the tetracarboxylic acid dianhydride or derivative thereof, it is more preferable to use at least one selected from a tetracarboxylic acid dianhydride represented by the following formula [6] or a derivative thereof.

[Chemical Formula 12]

In the formula [6], V ¹ is a tetravalent organic group having an alicyclic structure, and its structure is not particularly limited. Specific examples include the following formulas [V ¹ -1] to [V ¹ -44].

[Chemical Formula 13]

[Chemical Formula 14]

[Chemical Formula 15]

[Chemical Formula 16]

[Chemical Formula 17]

[Chemical Formula 18]

In the formulas [V ¹ -1] to [V ¹ -4], each of R ⁷ to R ²⁷ independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, An alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 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 alignability, R ⁷ to R ²⁷ are preferably a hydrogen atom, a halogen atom, a methyl group or an ethyl group, more preferably a hydrogen atom or a methyl group.

Specific structures of the formula [V ¹ -1] include structures represented by the following formulas [V ¹ -1-1] to [V ¹ -1-6]. From the viewpoint of the liquid crystal alignability and the sensitivity of the photoreaction, the structure represented by the following formula [V ¹ -1-1] is particularly preferable.

[Chemical Formula 19]

In the formula [4], W ¹ is not particularly limited as long as it is a divalent organic group derived from a diamine having a structure represented by the formula [2] or [3] do. W ¹ is a specific diamine corresponding to the structure of the diamine component used in the present invention and having a structure represented by the formula [1] (for example, the following formulas [W ¹ -1] to [W ¹ -13 And at least one kind of diamine selected from the group consisting of compounds represented by the following general formula (1).

[Chemical Formula 20]

In the formula [W ¹ -3], Boc represents a group (tert-butoxycarbonyl group) shown below.

[Chemical Formula 21]

However, it is not always necessary that all of W ¹ have a structure corresponding to the diamine. A structure corresponding to a diamine other than the diamine (other diamine) may be included in a part of W ¹ . (Hereinafter referred to as &quot; structure W ² &quot;) corresponding to other diamines can be generalized as shown by the following formula [7]. Examples of A ¹ and A ² in the following formula [7] include the same ones as in formula [4].

[Chemical Formula 22]

The structure W ² represented by the formula [7] is exemplified by the following formulas [W ² -1] to [W ² -173].

(23)

&Lt; EMI ID =

(25)

(26)

(27)

(28)

[Chemical Formula 29]

(30)

(31)

(32)

(33)

(34)

(35)

(36)

(37)

(38)

[Chemical Formula 39]

(40)

(41)

(42)

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.

(43)

When the polyimide precursor containing the structural unit represented by the formula [4] simultaneously contains the structural unit represented by the formula [7], the structural unit represented by the formula [4] Is preferably 10 mol% or more, more preferably 20 mol% or more, and particularly preferably 30 mol% or more based on the total amount.

The molecular weight of the polyimide precursor or polyimide as the polymer of the present invention is such that when a liquid crystal alignment film is obtained from a liquid crystal aligning agent containing the polymer, the strength of the film (liquid crystal alignment film), the workability at the time of film formation, The weight average molecular weight measured by gel permeation chromatography (GPC) is preferably 2,000 to 500,000, more preferably 5,000 to 300,000, and even more preferably 10,000 to 100,000 in consideration of uniformity.

&Lt; Process for producing polymer &

Next, the main production method of the polymer of the present invention will be described. In addition, the method described below is an example of production and is not limited thereto.

For example, in the case where the polymer containing a structural unit represented by the formula [4] is a polyamic acid as a polyimide precursor, such a polymer is obtained by reacting a tetracarboxylic acid dianhydride, a tetracarboxylic acid derivative, with a diamine component Lt; / RTI &gt; By the reaction, polyamic acid can be obtained by a known synthesis method. The synthesis method is a method of reacting a tetracarboxylic acid dianhydride and a diamine component in an organic solvent. Such a method is advantageous in that it proceeds relatively easily in an organic solvent and does not generate any by-products.

The organic solvent used in the above reaction is not particularly limited as long as the resulting polyamic acid (polymer) dissolves, and examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, Methyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide,? -Butyrolactone, isopropyl alcohol, Methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, ethyl cellosolve, ethyl cellosolve, Propylene glycol monoacetate, propylene glycol monoacetate, ethyleneglycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monoacetate, Diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether, Dipropylene glycol monoethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3 Methyl-3-methoxybutanol, diisopropylether, ethylisobutylether, diisobutylene, amyl acetate, butylbutyrate, butylether, diisobutylketone, methylcyclohexene, propylether, dihexylether, di Octane, n-hexane, n-pentane, n-octane, diethyl ether, cyclohexanone, Propyleneglycol monoethyl ether, methyl pyruvate, methyl pyruvate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate methyl ethyl ketone, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, , 3-methoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy- , 3-methoxy-N, N-dimethylpropanamide, 3-ethoxy-N, N-dimethylpropanamide and 3-butoxy-N, N-dimethylpropanamide. These may be used alone or in combination. In addition, a solvent which does not dissolve the polyamic acid (polymer) may be mixed with the above-mentioned organic solvent within the range in which the produced polyamic acid is not precipitated. Particularly, water in the organic solvent inhibits the polymerization reaction and further causes hydrolysis of the produced polyamic acid. Therefore, it is preferable to use an organic solvent which is dehydrated and dried as much as possible.

When the tetracarboxylic acid dianhydride and the diamine component are reacted in the organic solvent, the solution in which the diamine component is dispersed or dissolved in the organic solvent is stirred, and the tetracarboxylic acid dianhydride is dispersed or dissolved in the organic solvent , A method of adding a diamine component to a solution in which a tetracarboxylic acid dianhydride is dispersed or dissolved in an organic solvent, a method of alternately adding a tetracarboxylic acid dianhydride and a diamine component, and the like. Method may be used. When the tetracarboxylic acid dianhydride or diamine component is composed of a plurality of compounds, they may be reacted in a preliminarily mixed state, or they may be sequentially reacted individually. Further, the separately reacted low molecular weight compounds are mixed and reacted, May be used.

The polycondensation temperature at that time may be any temperature between -20 ° C and 150 ° C, preferably between -5 ° C and 100 ° C. When the concentration is too low, it becomes difficult to obtain a polymer having a high molecular weight. When the concentration is too high, the viscosity of the reaction liquid becomes excessively high and it becomes difficult to perform uniform stirring. Therefore, 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, and more preferably 5% by mass to 30% by mass. The initial stage of the reaction may be carried out 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 molar number of the tetracarboxylic acid dianhydrides to the total molar number of the diamine components (the total molar number of the tetracarboxylic acid dianhydrides / the total molar number of the diamine components) is 0.8 to 1.2 desirable. As in the case of the usual polycondensation reaction, the closer the molar ratio is to 1.0, the larger the molecular weight of the produced polyamic acid.

When the polymer containing the structural unit represented by the formula [4] is a polyamic acid ester, the reaction of the tetracarboxylic acid diester dichloride with the diamine component or the reaction of the tetracarboxylic acid diester and the diamine component with a suitable condensing agent or base In the presence of a base. Alternatively, a polyamic acid may be synthesized in advance by the above-mentioned method, and the carboxylic acid in the amic acid may be esterified using a polymer reaction.

Specifically, for example, tetracarboxylic acid diester dichloride and diamine are reacted in the presence of a base and an organic solvent at -20 ° C to 150 ° C, preferably 0 ° C to 50 ° C for 30 minutes to 24 hours, , It is possible to synthesize a polyamic acid ester by reacting it for 1 hour to 4 hours.

As the base, pyridine, triethylamine, 4-dimethylaminopyridine and the like can be used, but pyridine is preferable for the reaction to proceed mildly. The amount of the base to be added is preferably from 2 to 4 moles per mole of the tetracarboxylic acid diester dichloride from the viewpoint of easy removal and high molecular weight.

When the tetracarboxylic acid diester and the diamine component are polycondensed in the presence of a condensing agent, it is preferable to use, as the base, triphenylphosphite, dicyclohexylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) N, N ', N ', N ' -carbodiimidazole, dimethoxy-1,3,5-triazinylmethylmorphuronium, O- (benzotriazol- -Tetramethyluronium tetrafluoroborate, O- (benzotriazol-1-yl) -N, N, N ', N'-tetramethyluronium hexafluorophosphite, (2,3-dihydro 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methoxymorpholinium chloride n- Hydrates and the like can be used.

Further, in the method using the condensing agent, the reaction proceeds efficiently by adding Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferable. The addition amount of the Lewis acid is preferably 0.1 to 1.0 mole per mole of the diamine or tetracarboxylic acid diester to be reacted.

The solvent used in the above reaction may be the same solvent as the solvent used in the synthesis of the polyamic acid shown above. From the solubility of the monomer and the polymer, it is preferable to use N-methyl-2-pyrrolidone, And they may be used alone or in combination of two or more. From the viewpoint that precipitation of the polymer is difficult to occur and that a high molecular weight material can be easily obtained, the concentration at the time of the synthesis is preferably in the range of from 1 to 100 parts by weight per 100 parts by weight of the tetracarboxylic acid derivative in the reaction solution of the tetracarboxylic acid derivative such as tetracarboxylic acid diester dichloride or tetracarboxylic acid diester and diamine component Is preferably 1% by mass to 30% by mass, and more preferably 5% by mass to 20% by mass. In order to prevent the hydrolysis of the tetracarboxylic acid diester dichloride, the solvent used for the synthesis of the polyamic acid ester is preferably dehydrated as much as possible, and it is preferable to prevent the introduction of outside air in a nitrogen atmosphere.

In the case where the polymer containing the structural unit represented by the formula [4] is a polyimide, the polymer has a divalent group represented by the formula [2] or the formula [3] in the main chain and is obtained by dehydrocondylating the polyamic acid . In this polyimide, the dehydration / removal rate (imidization rate) of the amidic acid group does not necessarily have to be 100%, and can be arbitrarily adjusted depending on the purpose and purpose.

Examples of the method for imidizing polyamic acid include thermal imidization in which a solution of polyamic acid is heated as it is, and catalyst imidization in which a catalyst is added to a solution of polyamic acid.

The temperature at which the polyamic acid is thermally imidized in the solution is 100 ° C to 400 ° C, preferably 120 ° C to 250 ° C, and it is preferable to carry out the removal while removing the water generated by the imidization reaction out of the system.

The catalyst imidation of polyamic acid can be carried out by adding a basic catalyst and an acid anhydride to a solution of polyamic acid and stirring at -20 캜 to 250 캜, preferably 0 캜 to 180 캜. The amount of the basic catalyst is 0.5 to 30 times, preferably 2 to 20 times the amount of the amide group, and the amount of the acid anhydride is 1 to 50 times, preferably 3 to 30 times the amount of the amide group. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, etc. Among them, pyridine is preferred because it has a basicity suitable for proceeding the reaction. As the acid anhydride, acetic anhydride, trimellitic anhydride, pyromellitic anhydride and the like can be given. Of these, use of acetic anhydride is preferable since the purification after completion of the reaction becomes easy. The imidization rate by the catalyst imidization can be controlled by adjusting the catalyst amount, the reaction temperature, and the reaction time.

As described above, the polyimide can be obtained also by heating the polyamic acid ester at a high temperature and promoting the elimination of alcohol to cause the polyimide ester to be ring-closed.

In the case of recovering polyamic acid, polyamic acid ester and polyimide produced from a polyimide precursor such as polyamic acid or polyamic acid ester or a reaction solution of polyimide, the reaction solution may be put into a poor solvent and precipitated . Examples of poor solvents to be used in the precipitation include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene and water. The polyimide precursor or polyimide precipitated by charging in a poor solvent can be recovered by filtration and then dried at normal temperature or under reduced pressure or by heating. Further, by repeating the operation of redissolving the polyimide precursor or polyimide precipitated and recovered in the organic solvent and re-precipitating and recovering the solution 2 to 10 times, impurities in the polymer can be reduced. As the poor solvent at this time, for example, alcohols, ketones, hydrocarbons and the like can be exemplified, and when three or more poor solvents selected from these are used, the purification efficiency is further increased, which is preferable.

The thus obtained polymer of the present invention can be used as a liquid crystal aligning agent by dissolving in a predetermined organic solvent. This liquid crystal aligning agent is used in a liquid crystal alignment film for controlling the orientation properties of liquid crystal molecules in the liquid crystal layer in a liquid crystal display element. Hereinafter, the liquid crystal aligning agent containing the polymer of the present invention will be described.

<Liquid Crystal Aligner>

The liquid crystal aligning agent of the present invention contains a polymer obtained from a diamine component containing a diamine having a structure represented by the formula [2] derived from the diamine component. It is preferable that the liquid crystal aligning agent contains a polymer having the structure represented by the formula [3] derived from the diamine component. The polymer is preferably at least one selected from a polyimide precursor containing a structural unit represented by the formula [4] and a polyimide which is an imide compound thereof.

However, all of the polymers contained in the liquid crystal aligning agent of the present invention may be polymers of the present invention. In addition, in order to exert the effects described in the present invention, among the polymers of the present invention, . Alternatively, in addition to the polymer of the present invention, other polymer, that is, a polymer having no bivalent group represented by formula [2] or formula [3] may be contained. Examples of the other polymer include polyamic acid, polyimide, polyamic acid ester, polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivative, polyacetal, polystyrene or a derivative thereof, poly (styrene-phenylmaleimide ) Derivatives, and poly (meth) acrylates.

When the liquid crystal aligning agent of the present invention contains other polymer, the proportion of the polymer of the present invention to the whole polymer component is preferably 5% by mass or more, and for example, 5% by mass to 95% by mass is exemplified. The proportion of the polymer of the present invention can be appropriately selected depending on the properties of the liquid crystal aligning agent and the liquid crystal alignment film.

The liquid crystal aligning agent of the present invention is used for producing a liquid crystal alignment film and generally takes the form of a coating liquid from the viewpoint of forming a uniform thin film. The liquid crystal aligning agent of the present invention is also preferably a coating liquid containing the above polymer component and an organic solvent for dissolving the polymer component. At that time, 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. In view of forming a uniform and defect-free coating film, it is preferably 1% by mass or more, and from the viewpoint of the storage stability of the solution, 10% by mass or less is preferable. 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 the present invention is not particularly limited as long as it is an organic solvent capable of dissolving the polymer. Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N- , 1,3-dimethyl-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, and 4-hydroxy-4-methyl-2-pentanone. Among them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone and? -Butyrolactone are preferably used. The organic solvents exemplified herein may be used alone or in combination. The solvent may be a solvent that does not dissolve the polymer, or may be mixed with an organic solvent within the range in which the resulting polymer is not precipitated.

As the organic solvent contained in the liquid crystal aligning agent, in addition to the above-mentioned solvents, a mixed solvent in which a solvent for improving the coating property and the surface smoothness of the coating film when the liquid crystal aligning agent is applied is generally used, Also in the liquid crystal aligning agent of the present invention, such a mixed solvent is preferably used. Specific examples of the organic solvent used in combination include, but are not limited to, the following examples.

Butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, Butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 2-methyl- Butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, cyclohexanol, 1-methylcyclohexanol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,3-propanediol, 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, ethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, Ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monoacetate, ethylene glycol monoacetate, ethylene glycol monoacetate, (Methoxymethoxy) ethanol, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, ethylene glycol monohexyl ether, 2- (hexyloxy) ethanol, furfuryl alcohol, diethylene glycol, propylene glycol, propylene Propanol, propylene glycol monomethyl ether acetate, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether, Propylene 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 mono Ethyl ether acetate, diethylene glycol monobutyl ether acetate, 2- (2-ethoxyethoxy) ethyl acetate, diethylene glycol acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methyl lactate , Ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, 3-ethoxypropionic acid, 3 A solvent such as methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, lactic acid methyl ester, lactic acid ethyl ester, n-propyl lactate, n-butyl lactate and isoamyl lactate have.

In addition to the above-mentioned solvents, for example, solvents represented by the following formulas [S-1] to [S-3] can be used.

(44)

In the formulas [S-1] and [S-2], R ²⁸ and R ²⁹ represent an alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. In the formula [S-3], R ³⁰ represents an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert- .

Among the organic solvents used in combination, preferred are organic solvents such as 1-hexanol, cyclohexanol, 1,2-ethanediol, 1,2-propanediol, propylene glycol monobutyl ether, diethylene glycol diethyl ether, -2-pentanone, ethylene glycol monobutyl ether or dipropylene glycol dimethyl ether. The kind and content of the solvent are appropriately selected according to the application device of the liquid crystal aligning agent, application conditions, application environment, and the like.

These solvents are preferably 20% by mass to 99% by mass of the total solvent contained in the liquid crystal aligning agent. Among them, 20% by mass to 90% by mass is preferable. More preferred is 20 mass% to 70 mass%.

The liquid crystal aligning agent of the present invention may further contain components other than the polymer component and the organic solvent within the range not hindering the effect of the present invention. Examples of such additional components include adhesion auxiliary agents for enhancing adhesion between the liquid crystal alignment film and the substrate, adhesion between the liquid crystal alignment film and the sealing material, crosslinking agents for increasing the strength of the liquid crystal alignment film, dielectric materials for adjusting the dielectric constant and electrical resistance of the liquid crystal alignment film, And the like. Specific examples of these additional components include various disclosures in known documents relating to liquid crystal aligning agents. However, examples thereof are disclosed in paragraphs [0105] to [0116] of International Publication No. 2015/060357 And the like.

&Lt; Liquid crystal alignment film &

The liquid crystal alignment film of the present invention is obtained from the above-mentioned liquid crystal aligning agent. An example of a method of obtaining a liquid crystal alignment film from a liquid crystal aligning agent includes a method of applying a liquid crystal aligning agent in the form of a coating liquid to a substrate, drying and firing the obtained film to perform orientation treatment by a rubbing treatment method or a photo alignment treatment method .

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

The application method of the liquid crystal aligning agent is not particularly limited, but industrially, screen printing, offset printing, flexographic printing, inkjet printing, and the like are common. Examples of other coating methods include a dipping method, a roll coater method, a slit coater method, a spinner method, and a spraying method, and they may be used depending on the purpose.

The baking after coating the liquid crystal aligning agent on the substrate is carried out by heating means such as a hot plate, a hot air circulation furnace or an infrared ray furnace at 50 to 300 캜, preferably 80 to 250 캜, A coating film (liquid crystal alignment film) can be formed. When the thickness of the coating film formed after firing is too large, the power consumption of the liquid crystal display element is disadvantageously deteriorated. When the thickness is excessively thin, the reliability of the liquid crystal display element may be deteriorated, and preferably 5 nm to 300 nm Lt; RTI ID = 0.0 &gt; nm. &Lt; / RTI &gt; When the liquid crystal is horizontally oriented or tilted, the coated film after firing is subjected to rubbing, polarized ultraviolet irradiation, or the like.

After the liquid crystal aligning agent is applied onto the substrate, the solvent is evaporated and fired by a heating means such as a hot plate, a heat circulation type oven, or an IR (infrared) type oven. The drying and firing steps after application of the liquid crystal aligning agent can be carried out at arbitrary temperature and time. Usually, conditions for firing at 50 ° C to 120 ° C for 1 minute to 10 minutes and then at 150 ° C to 300 ° C for 5 minutes to 120 minutes are sufficient for sufficiently removing the contained solvent.

The liquid crystal alignment film of the present invention is preferably used as a liquid crystal alignment film of a liquid crystal display element of a transverse electric field system such as an IPS system or an 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>

The liquid crystal display element of the present invention comprises the above-described liquid crystal alignment film. After obtaining a substrate on which the liquid crystal alignment film obtained from the above-described liquid crystal aligning agent is formed, a liquid crystal cell is manufactured by a known method, As shown in Fig. A liquid crystal display element having a liquid crystal cell formed between the substrate and the liquid crystal layer and having a liquid crystal alignment film formed by the liquid crystal aligning agent of the present invention; to be.

The substrate used in the liquid crystal display of the present invention is not particularly limited as long as it is a substrate having high transparency. Usually, it is a substrate on which a transparent electrode for driving liquid crystal is formed. Specific examples include the same substrates as those described in the above-described liquid crystal alignment film.

The liquid crystal alignment film is formed by applying the liquid crystal aligning agent of the present invention on this substrate and then firing, and the details are the same as described above.

The liquid crystal material constituting the liquid crystal layer of the liquid crystal display element of the present invention is not particularly limited and examples thereof include nematic liquid crystal and smectic liquid crystal. Among them, nematic liquid crystal is preferable, and positive liquid crystal material and negative liquid crystal material May be used. Specifically, for example, MLC-2003, MLC-6608, MLC-6609, MLC-3019, MLC-2041 and MLC-7026-100 manufactured by Merck Ltd. can be used.

Specifically, a transparent glass substrate is prepared, 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 to enable desired image display. 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, under the above-described conditions, a liquid crystal alignment film is formed on each substrate.

Subsequently, for example, an ultraviolet ray-curable sealing material is disposed at a predetermined position on one of the two substrates on which the liquid crystal alignment film is formed, the liquid crystal is further arranged at a predetermined number of points on the liquid crystal alignment film surface, The liquid crystal is spread on the entire surface of the liquid crystal alignment film by pressing and adhering the other substrate so as to face the other side of the liquid crystal alignment film and then the ultraviolet rays are irradiated to the entire surface of the substrate to cure the sealant to obtain a liquid crystal cell.

Alternatively, as a step after the liquid crystal alignment film is formed on the substrate, when the sealant is arranged at a predetermined position on one of the substrates, an opening capable of filling the liquid crystal from the outside is formed, , A liquid crystal material is injected into the liquid crystal cell through the opening formed in the sealing material, and then the opening is sealed with an adhesive to obtain a liquid crystal cell. The injection of the liquid crystal material may be a vacuum injection method or a method using capillary phenomenon in the atmosphere.

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 protrusion is formed on one of the substrates, a spacer is scattered on one of the substrates, a spacer is mixed in the sealing material , Or a combination thereof.

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

Further, the liquid crystal alignment film and the liquid crystal display element of the present invention are not limited to the above-described substrates as long as the liquid crystal aligning agent of the present invention is used, and may be those produced by any other known method. The processes from the liquid crystal aligning agent to the liquid crystal display element are disclosed in, for example, Japanese Laid-Open Patent Publication No. 2015-135393, paragraphs [0074] to paragraph [0081] and the like.

As described above, the liquid crystal display device manufactured using the liquid crystal aligning agent of the present invention is excellent in reliability, and can be preferably used for a liquid crystal television having a large screen and a high definition.

Example

Hereinafter, the production method of the present invention will be described with reference to experimental methods and results of examining the composition of raw materials and blending ratios, and examples of typical production methods, but the present invention is not limited to these examples no.

The abbreviations of the compound and the solvent, and the method of evaluating the properties are as follows.

[Chemical Formula 45]

(46)

<Organic solvent>

NMP: N-methyl-2-pyrrolidone

NEP: N-ethyl-2-pyrrolidone

GBL:? -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

LS-3150: 3-aminopropyltriethoxysilane

< ¹ H-NMR measurement>

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

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

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

<Molecular Weight Measurement of Polyimide Precursor and Imidized Polymer>

(GPC) apparatus (GPC-101) (manufactured by Showa Denko K.K.) and column (KD-803, KD-805) (manufactured by Shodex) at room temperature were measured under the following conditions.

Column temperature: 50 ° C

Eluent: N, N'- dimethylformamide (as an additive, lithium bromide-hydrate (LiBr · H ₂ O) is 30 mmol / ℓ (L), phosphoric acid anhydrous crystal (o- phosphoric acid) is 30 mmol / ℓ, tetra 10 ml / l of hydrofuran (THF)

Flow rate: 1.0 ml / min

(Standard molecular weight: about 12,000, 4,000, and 1,000, manufactured by Polymer Laboratories), TSK standard polyethylene oxide having a molecular weight of about 900,000, 150,000, 100,000, and 30,000,

<Viscosity Measurement>

The viscosity of the polyamic acid solution was measured by using an E-type viscometer TVE-22H (manufactured by Toki Industries Co., Ltd.) and a sample amount of 1.1 ml, a cone rotor TE-1 (1 ° 34 ', R24 ).

&Lt; Synthesis of diamine compound (DA-1) &gt;

(47)

BNPU (50 g, 140 mmol), potassium carbonate (44.4 g, 320 mmol) and NMP (1000 g) were charged into a 2 L four-necked flask, Aqueous glyoxal solution (46.7 g, 320 mmol) was added dropwise over 10 minutes, and the mixture was stirred for 12 hours. Potassium carbonate (44.4 g, 320 mmol) and a 40% aqueous glyoxal solution (46.7 g, 320 mmol) were further added to the mixture, and the mixture was stirred for 12 hours to obtain a compound [ A]. After confirming the disappearance of the raw material, the salt was filtered, and sulfuric acid (15 g) was added dropwise to make the solution acidic, followed by stirring at 70 ° C for 24 hours. After completion of the reaction was confirmed by HPLC, methanol (1000 g) and pure water (1000 g) were added and the mixture was cooled to 5 캜 and stirred for 1 hour. The precipitated crystals were filtered under reduced pressure, washed with methanol (100 g) and dried to obtain powder crystals (compound [B]) (yield: 41.7 g, yield: 76%).

(48)

A mixture of the obtained compound [B] (35 g, 87.8 mmol), 5 mass% Pd / C (50% aqueous solution), characteristic Shirasai activated carbon (3.5 g), and dioxane (350 g) C &lt; / RTI &gt; for 8 hours. After completion of the reaction, the catalyst was filtered off and concentrated. 2-Propanol (350 g) was added and the mixture was stirred at 5 캜 for 1 hour. The precipitated crystals were filtered under reduced pressure, washed with 2-propanol (70 g) and dried to obtain powder crystal DA-1 (yield 27 g, yield 92%).

[Synthesis Example 1]

DA-1 (3.38 g, 10.0 mmol) was added to a 100-ml four-necked flask equipped with a stirrer and a nitrogen inlet tube, 28.8 g of NMP was added, . To this solution was added 9.6 g of CA-1 (0.87 g, 4.0 mmol), CA-2 (1.08 g, 5.5 mmol) and NMP and further stirred at 50 ° C for 12 hours, A polyamic acid solution (PAA-A1) shown in Fig.

[Synthesis Example 2 to Synthesis Example 5]

Except that a diamine component, a tetracarboxylic acid component, and NMP (N-methyl-2-pyrrolidone) shown in the following Table 1 were used and the reaction temperature was changed, respectively, (PAA-A2) and polyamic acid solutions (PAA-B1) to (PAA-B3) shown in Table 1 were obtained.

[Examples 1 to 10 and Comparative Examples 1 and 2]

The polyamic acid solution obtained in Synthesis Examples 1 to 5 was added with a solvent and an additive while stirring so that the solvent in the resulting liquid crystal aligning agent had the composition shown in Table 2 and Table 3 below. By stirring, liquid crystal aligning agents were obtained.

In addition, * 1 to * 3 in Tables 2 and 3 are as follows.

* 1: Represents the amount (parts by weight) of each polymer introduced into 100 parts by weight of all polymers.

* 2: The amount (parts by weight) of each additive introduced into 100 parts by weight of all polymers.

* 3: represents the amount (parts by weight) of the solvent introduced into 100 parts by mass of the liquid crystal aligning agent.

&Lt; Production of liquid crystal display element by rubbing method &gt;

A glass substrate with a size of 30 mm x 35 mm and an electrode with a thickness of 0.7 mm was prepared. On the substrate, an IZO electrode having a beta-pattern constituting the counter electrode as the first layer is formed. On the first layer counter electrode, a SiN (silicon nitride) film formed by the CVD method is formed as the second layer. The thickness of the second-layer SiN film is 500 nm and functions as an interlayer insulating film. On the second-layer SiN film, pixel electrodes on the combs formed by patterning the IZO film as the third layer are disposed, and two pixels, i.e., the first pixel and the second pixel, are formed. The size of each pixel is 10 mm in length and 5 mm in width. At this time, the first layer counter electrode and the third layer pixel electrode are electrically insulated by the action of the second layer SiN film.

The third layer pixel electrode has a comb-like shape formed by arranging a plurality of elongated electrode elements bent at a central portion as shown in the drawing (Fig. 3) described in Japanese Patent Laid-Open Publication No. 2014-77845. The width of each electrode element in the width direction is 3 mu m, and the interval between the electrode elements is 6 mu m. Since the pixel electrode forming each pixel is constituted by arranging a plurality of elongated electrode elements bent at the center portion, the shape of each pixel is not a rectangular shape, and a thick It has a similar shape. Each pixel is divided into upper and lower portions with the central bent portion as a boundary, and has a first region on the upper side of the bent portion and a second region on the lower side.

When the first region and the second region of each pixel are compared with each other, the formation direction of the electrode elements of the pixel electrodes constituting the first region and the second region is different. In other words, when the rubbing direction of a liquid crystal alignment film to be described later is taken as a reference, the electrode elements of the pixel electrodes are formed so as to form an angle of +10 degrees (clockwise) in the first region of the pixel, The element is formed so as to form an angle of -10 DEG (counterclockwise direction). In the first region and the second region of each pixel, the direction of the rotation operation (in-plane switching) of the liquid crystal caused by the application of the voltage between the pixel electrode and the counter electrode is opposite to each other Consists of.

Next, after filtering the liquid crystal aligning agent with a filter having a size of 1.0 mu m, an ITO film was formed on the back surface of the substrate on which the electrode was adhered and the opposite substrate, and a spin- Lt; / RTI &gt; Subsequently, the substrate was dried on a hot plate at 80 DEG C for 5 minutes, and then baked at 230 DEG C for 20 minutes to obtain a polyimide film having a film thickness of 60 nm on each substrate. Rubbing treatment was performed on the polyimide film surface with a rayon bath under 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 pressing pressure of 0.3 mm, And dried at 80 DEG C for 10 minutes.

Using the two kinds of substrates having the liquid crystal alignment layers formed thereon, the rubbing directions were combined so as to be in antiparallel, and the periphery was sealed while leaving the liquid crystal injection ports, and a blank cell having a cell gap of 3.8 mu m was manufactured. A liquid crystal (MLC-3019, manufactured by Merck & Co., Inc.) was vacuum-injected into the empty cell at room temperature, and then the injection port was sealed to obtain an anti-parallel alignment liquid crystal cell. The resulting liquid crystal cell constitutes an FFS mode liquid crystal display element. Thereafter, the liquid crystal cell was heated at 120 DEG C for 1 hour, left standing overnight, and used for evaluation.

&Lt; Evaluation of flicker level immediately after driving &gt;

The prepared liquid crystal cell was placed between two polarizers arranged so that the polarization axes thereof were orthogonal to each other. The LED backlight was turned on in a voltage-unapplied state and the arrangement angle of the liquid crystal cell was adjusted so that the luminance of transmitted light was minimized. Next, a V-T curve (voltage-transmittance curve) was measured while applying an AC voltage with a frequency of 30 Hz to this liquid crystal cell, and an AC voltage having a relative transmittance of 23% was calculated as a drive voltage.

In the measurement of the flicker level, the LED backlight that was turned on was once turned off and left to stand for 72 hours. After that, the LED backlight was turned on again and an alternating voltage of 30 Hz in which the relative transmittance was 23% , And the liquid crystal cell was driven for 60 minutes to track the flicker amplitude. The flicker amplitude was read by a data collecting / data logger switch unit 34970A (manufactured by Agilent Technologies) connected via two photodiodes and an IV conversion amplifier, through the two polarizing plates and the liquid crystal cell between them, and the transmitted light of the LED backlight . The flicker level was calculated by the following equation [8].

Flicker level (%) = {Flicker amplitude / (2 x z)} x 100 ... [8]

In Equation [8], z is a value obtained by reading the data obtained by the data collecting / data logger switch unit 34970A at the time of driving with an AC voltage having a frequency of 30 Hz at which the relative transmittance is 23%.

The evaluation of the flicker level was carried out when the flicker level was maintained at less than 3% until 60 minutes elapsed from the time when the LED backlight was turned on and the application of the AC voltage started, ) Is defined as the following. When the flicker level reached 3% or more in 60 minutes, &quot; x &quot; (flicker shift easily occurs immediately after the start of driving) was evaluated.

The evaluation of the flicker level according to the above-described method was carried out under a temperature condition in which the temperature of the liquid crystal cell was 23 占 폚.

&Lt; Evaluation result &gt;

The results of the after-image-erasing time evaluation and the flicker level evaluation immediately after the above-described operation on the liquid crystal display elements using the respective liquid crystal aligning agents of Examples 1 and 2 and Comparative Examples 1 and 2 were shown in Table 4 Respectively.

As shown in Table 4, the liquid crystal display elements using the liquid crystal aligning agents of Examples 1 and 2 are found to be difficult to cause flicker shift immediately after the start of driving.

Industrial availability

The liquid crystal display device manufactured by using the liquid crystal aligning agent obtained by the diamine of the present invention can be a liquid crystal display device in which the flicker shift immediately after the start of driving is reduced and can be used as a liquid crystal display device such as TN (Twisted Nematic) liquid crystal display device, STN liquid crystal display device , A TFT liquid crystal display device, a VA liquid crystal display device, an IPS liquid crystal display device, and an OCB (Optically Self-Compensated Birefringence) liquid crystal display device.

Claims (7)

A diamine characterized by the following formula [1].

(1), Y ¹ and Y ² are each independently a single bond, -O-, -S-, -COO- or -OCO-, R ¹ and R ² are each independently -H, -OH, = O or a monovalent organic group, and R ³ and R ⁴ are each independently an alkylene group having 1 to 3 carbon atoms, and any hydrogen atom of the benzene ring is substituted with a monovalent organic group It may be.) A polymer obtained from a diamine component containing a diamine having a structure represented by the following formula [2].

(Wherein Y ¹ is a single bond, -O-, -S-, -COO- or -OCO-, R ¹ and R ² are each independently -H, -OH, = O or R ³ is an alkylene group having 1 to 3 carbon atoms, and * indicates a site bonded to another group. Further, any hydrogen atom of the benzene ring may be substituted with a monovalent organic group do.) 3. The method of claim 2,
Is obtained from a diamine component containing a diamine having a structure represented by the following formula [3].

(Wherein, Y ¹ and Y ² are each independently a single bond, -O-, -S-, -COO- or -OCO-, R ¹ and R ² are each independently -H, R ³ and R ⁴ are each independently an alkylene group having 1 to 3 carbon atoms and * indicates a site bonded to another group. In addition, an arbitrary number of benzene rings May be substituted with a monovalent organic group.) The method according to claim 2 or 3,
Is a polyimide precursor containing a structural unit represented by the following formula [4] and a polyimide which is an imide compound thereof.

(In the 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 a diamine having a structure represented by the formula [2] or [3] R ⁵ and R ^{6 each} represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; A ¹ and A ² each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, An alkenyl group having 5 to 5 carbon atoms or an alkynyl group having 2 to 5 carbon atoms. A liquid crystal aligning agent containing the polymer according to any one of claims 2 to 4 and an organic solvent. A liquid crystal alignment film obtained from the liquid crystal alignment agent according to claim 5. A liquid crystal display element comprising the liquid crystal alignment film according to claim 6.