KR20220079530A - Liquid crystal aligning agent, liquid crystal aligning film, and liquid crystal display element using same - Google Patents

Abstract

(식 (3) 중, n1 과 n2 는 각각 독립적으로 1 ∼ 3 의 정수를 나타낸다.)
중합체 (B) : 상기 식 (1) 로 나타내는 제 1 디아민, 상기 식 (2) 로 나타내는 제 2 디아민, 및 상기 식 (3) 으로 나타내는 제 3 디아민을 동시에는 포함하지 않는 디아민 성분과, 테트라카르복실산 2 무수물과의 중축합으로 얻어지는 폴리아믹산.The liquid crystal aligning agent containing a following polymer (A) and a polymer (B).
Polymer (A): The diamine component containing the 1st diamine represented by following formula (1), the 2nd diamine represented by Formula (2), and the 3rd diamine represented by Formula (3), and tetracarboxyl which has an alicyclic structure The polyamic acid obtained by polycondensation with acid dianhydride.

(In Formula (3), n1 and n2 each independently represent the integer of 1-3.)
Polymer (B): The diamine component which does not contain simultaneously the 1st diamine represented by the said Formula (1), the 2nd diamine represented by the said Formula (2), and the 3rd diamine represented by the said Formula (3), and tetracar The polyamic acid obtained by polycondensation with acid dianhydride.

Description

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

This invention relates to a liquid crystal display element provided with a liquid crystal aligning agent, the liquid crystal aligning film obtained by this liquid crystal aligning agent, and the obtained liquid crystal aligning film.

DESCRIPTION OF RELATED ART Liquid crystal display elements are widely used as display parts, such as a personal computer, a mobile phone, a smart phone, and a television. The liquid crystal display element includes, for example, a liquid crystal layer sandwiched between the element substrate and the color filter substrate, a pixel electrode and a common electrode that apply an electric field to the liquid crystal layer, an alignment film that controls the alignment of liquid crystal molecules in the liquid crystal layer, A thin film transistor (TFT) or the like for switching an electric signal supplied to the pixel electrode is provided. As a driving method of liquid crystal molecules, a longitudinal electric field system, such as a TN system and a VA system, and a transverse electric field system, such as an IPS system and an FFS system, are known. In the transverse electric field method in which electrodes are formed only on one side of the substrate and an electric field is applied in a direction parallel to the substrate, compared to the conventional vertical electric field method in which a voltage is applied to the electrodes formed on the upper and lower substrates to drive the liquid crystal, wide viewing angle characteristics are improved. It has and is known as a liquid crystal display element capable of high-quality display.

Although the transverse electric field type liquid crystal cell has excellent viewing angle characteristics, since there are few electrode portions formed in the substrate, if the voltage retention is low, sufficient voltage is not applied to the liquid crystal and display contrast is lowered. Moreover, when stability of a liquid-crystal orientation is small, when a liquid crystal is driven for a long time, since a liquid crystal will not return to an initial state and it will become a cause of a contrast fall and an afterimage, stability of a liquid-crystal orientation is important. In addition, static electricity is easy to accumulate in the liquid crystal cell, and even by application of a positive and negative asymmetric voltage generated by driving, electric charges are accumulated in the liquid crystal cell, and these accumulated charges affect the display as disturbance of liquid crystal alignment or an afterimage. This significantly reduces the display quality of the liquid crystal element. In addition, even when the backlight light is irradiated to the liquid crystal cell immediately after driving, electric charges are accumulated, which causes problems such as afterimages and flickering during driving even for a short period of time.

When it is used for such a liquid crystal display element of a transverse electric field system, it is excellent in voltage retention, and as a liquid crystal aligning agent which reduced electric charge accumulation, in patent document 1, the polymer obtained by polycondensing specific diamine and an aliphatic tetracarboxylic acid derivative. A liquid crystal aligning agent containing is disclosed. However, with performance improvement of a liquid crystal display element, the characteristic calculated|required of a liquid crystal aligning film is also becoming strict, and it is difficult to fully satisfy|fill all the requested|required characteristics by these conventional techniques.

International Publication No. WO2004/021076 pamphlet

Liquid crystal provided with the liquid crystal aligning agent which is excellent in stability of a liquid-crystal orientation, and can obtain the liquid crystal aligning film which flicker (flicker) hardly occurs during drive, the liquid crystal aligning film obtained by the said liquid crystal aligning agent, and the obtained liquid crystal aligning film It is an object to provide a display element.

As a result of these inventors earnestly examining in order to solve the said subject, they found out that said subject was improved by introduce|transducing some specific structure in the polymer contained in a liquid crystal aligning agent, and completed this invention.

This invention is based on this knowledge, and makes the following summary.

The liquid crystal aligning agent containing a following polymer (A) and a polymer (B).

Polymer (A): The diamine component containing the 1st diamine represented by following formula (1), the 2nd diamine represented by Formula (2), and the 3rd diamine represented by Formula (3), and tetracarboxyl which has an alicyclic structure The polyamic acid obtained by polycondensation with acid dianhydride.

[Formula 1]

(In Formula (3), n1 and n2 each independently represent the integer of 1-3.)

Polymer (B): The diamine component which does not contain simultaneously the 1st diamine represented by the said Formula (1), the 2nd diamine represented by the said Formula (2), and the 3rd diamine represented by the said Formula (3), and tetracar The polyamic acid obtained by polycondensation with acid dianhydride.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows an example of a transverse electric field liquid crystal display element.
It is a schematic sectional drawing which shows the other example of a transverse electric field liquid crystal display element.

The liquid crystal aligning agent of this invention contains the polymer (A) and polymer (B) which are described below.

<Polymer (A)>

The polymer (A) used for this invention is a diamine component containing the 1st diamine represented by following formula (1), the 2nd diamine represented by Formula (2), and the 3rd diamine represented by Formula (3), and an alicyclic It is a polyamic acid obtained by polycondensation with tetracarboxylic dianhydride which has a structure.

[Formula 2]

In formula (3), n1 and n2 each independently represent the integer of 1-3.

Although the content rate of the diamine of said Formula (1)-(3) in a polymer (A) is not specifically limited, Diamine of Formula (1) is 10-70 with respect to all the diamine components which comprise a polymer (A). It is preferable in mol%, 10-70 mol% of diamine of Formula (2), and 5-50 mol% of diamine of Formula (3).

Moreover, the diamine component of a polymer (A) may contain diamine other than said Formula (1)-(3). As a content rate of diamine other than Formula (1) - (3), it is preferable that it is 50 mol% or less with respect to all the diamine components which comprise a polymer (A), More preferably, it is 30 mol% or less.

In a polymer (A), the structure in particular of tetracarboxylic dianhydride which has an alicyclic structure is not limited. Moreover, the number of structures of tetracarboxylic dianhydride which has an alicyclic structure in a polymer (A) may be one, and two or more types may be mixed.

Although the preferable structure of tetracarboxylic dianhydride which has an alicyclic structure in a polymer (A) is shown below, this invention is not limited to these.

[Formula 3]

The polymer (A) used for this invention may be the polymer which modified the principal chain terminal using the compound which is monofunctional with respect to a tetracarboxylic-acid derivative component and/or a diamine component. As the monofunctional compound, a monoamine, a monoisocyanate, the compound which has one acid anhydride group, the compound which has one acid chloride group, etc. are mentioned.

Although the molecular weight of a polymer (A) is not specifically limited as long as a favorable coating film can be formed, For example, 2,000-500,000 are preferable in a weight average molecular weight, More preferably, it is 5,000-300,000, More preferably 10,000 to 100,000. Moreover, the number average molecular weight becomes like this. Preferably it is 1,000-250,000, More preferably, it is 2,500-150,000, More preferably, it is 5,000-50,000.

<Polymer (B)>

Polymer (B) used for this invention is a diamine component which does not contain the 1st diamine represented by said Formula (1), the 2nd diamine represented by Formula (2), and 3rd diamine represented by Formula (3) simultaneously And it is a polyamic acid obtained by polycondensation with tetracarboxylic dianhydride.

The polymer (B) is a polymer different from the polymer (A). Then, the polymer (B) is obtained using the diamine component which does not contain the 1st diamine represented by Formula (1), the 2nd diamine represented by Formula (2), and the 3rd diamine represented by Formula (3) simultaneously It is prescribed that it is a polyamic acid.

As diamine contained in the diamine component of a polymer (B), the compound represented by following formula (4) is mentioned.

[Formula 4]

In Formula (4), Y< ₁ > represents a divalent organic group, and two R represents a hydrogen atom or a C1-C5 alkyl group each independently.

Although one type of diamine may be sufficient as the diamine component in a polymer (B), and two or more types of diamines may be mixed, the 1st diamine represented by Formula (1), the 2nd diamine represented by Formula (2), and Formula ( 3) The tertiary diamine represented by is not included at the same time. It is preferable not to contain any diamine represented by said Formula (1)-(3) as a diamine component of a polymer (B).

About the compound represented by said Formula (4), although the structure of Y< ₁ > in a compound especially preferable as a diamine component of a polymer (B) is shown below, this invention is not limited to these.

[Formula 5]

One type may be sufficient as the compound of Formula (4) whose Y< ₁ > is a structure of any of said above, and 2 or more types may be mixed in the diamine component of a polymer (B).

Moreover, it is preferable that Y< ₁ > further contains the compound of Formula (4) whose structure is any of the following.

[Formula 6]

In the above, Boc represents a group represented by the following.

[Formula 7]

In the polymer (B), the structure of tetracarboxylic dianhydride is not particularly limited. Moreover, the number of structures of tetracarboxylic dianhydride in a polymer (B) may be one, and two or more types may be mixed.

Although the preferable structure of tetracarboxylic dianhydride in a polymer (B) is shown below, this invention is not limited to these.

[Formula 8]

The polymer (B) used for this invention may be the polymer which modified the principal chain terminal using the compound which is monofunctional with respect to a tetracarboxylic-acid derivative component and/or a diamine component. As the monofunctional compound, a monoamine, a monoisocyanate, the compound which has one acid anhydride group, the compound which has one acid chloride group, etc. are mentioned.

Although the molecular weight of a polymer (B) is not specifically limited as long as a favorable coating film can be formed, For example, 2,000-500,000 are preferable in a weight average molecular weight, More preferably, it is 5,000-300,000, More preferably 10,000 to 100,000. Moreover, the number average molecular weight becomes like this. Preferably it is 1,000-250,000, More preferably, it is 2,500-150,000, More preferably, it is 5,000-50,000.

<Liquid crystal aligning agent>

Liquid crystal aligning agent of this invention WHEREIN: Although the compounding ratio of a polymer (A) and a polymer (B) is not specifically limited, Content of a polymer (A) is 50- with respect to the sum total of a polymer (A) and a polymer (B) It is preferable in it being 90 mass %, More preferably, it is 60-80 mass %.

The liquid crystal aligning agent of this invention may contain other polymers other than a polymer (A) and a polymer (B). The main skeleton of the other polymer is not particularly limited, and for example, polyamic acid, polyamic acid ester, polyimide, polysiloxane, polyester, cellulose derivative, polyacetal, polystyrene derivative, poly(styrene-maleimide) derivative, poly and polymers containing (meth)acrylate as a main skeleton.

The liquid crystal aligning agent of this invention may contain components other than a polymer. As components other than the polymer, a dielectric or conductive material for the purpose of changing electrical properties such as dielectric constant and conductivity of the liquid crystal aligning film, a silane coupling agent for the purpose of improving the adhesion between the liquid crystal aligning film and the substrate, the hardness of the film when the liquid crystal aligning film is used or the crosslinkable compound for the purpose of increasing the density, and an imidation accelerator for the purpose of efficiently advancing imidization of a polyamic acid when baking a coating film by extension, etc. are mentioned.

The liquid crystal aligning agent of this invention is used in order to manufacture a liquid crystal aligning film, It is preferable that it is the coating liquid which melt|dissolved said component in the organic solvent from a viewpoint of forming a uniform thin film. The density|concentration of the polymer in a liquid crystal aligning agent is changed suitably with the thickness of the coating device to be used, and the liquid crystal aligning film to be obtained. It is preferable that it is 1 mass % or more from the point of forming a uniform and defect-free coating film, and it is preferable to set it as 10 mass % or less from the point of storage stability of a solution. A particularly preferable concentration of the polymer is 2 to 8% by mass.

The organic solvent used for the said coating liquid will not be specifically limited if a polymer component melt|dissolves uniformly. Specific examples thereof include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethylsulfoxide, γ-buty Lolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, etc. are mentioned. Among them, it is preferable to use N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, or γ-butyrolactone. These solvents may use 2 or more types together.

Moreover, in the composition aimed at coating-film formation, it is common to use the mixed solvent which added the solvent which improves applicability|paintability improvement and the smoothness of the coating-film surface in addition to the above solvents, Also in the liquid crystal aligning agent of this invention Such a mixed solvent is suitably used. Although the specific example of the organic solvent to mix 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, 1,4 -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-pentanone, 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 monomethyl ether acetate, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl Ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol dia Cetate, ditylene 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 monoethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, 3-methoxymethyl propionate, 3-ethoxy methyl propionate, 3 -Ethyl methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, 3-methoxypropionic acid propyl, 3-methoxypropionate butyl, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, lactic acid Somamil, the solvent shown by the following formula [D-1] - [D-3], etc. are mentioned.

[Formula 9]

(R in formula [D-1] and formula [D-2] represents a C1-C3 alkyl group, R in formula [D-3] represents a C1-C4 alkyl group.)

Among the above, 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 preferable. The kind and content of such a solvent are suitably selected according to the coating apparatus of a liquid crystal aligning agent, application|coating conditions, application|coating environment, etc. Moreover, these solvents may use 2 or more types together.

<Liquid crystal alignment film>

The liquid crystal aligning film of this invention is obtained from the said liquid crystal aligning agent of this invention. If an example of the method of obtaining a liquid crystal aligning film from a liquid crystal aligning agent is given, the liquid crystal aligning agent in the form of a coating liquid is apply|coated to a board|substrate, dried, and the method of orientation-processing by the rubbing treatment method or the photo-alignment method with respect to the film|membrane obtained by baking. can be heard

It does not specifically limit as a board|substrate which apply|coats a liquid crystal aligning agent, Plastic substrates, such as a glass substrate, a silicon nitride board|substrate, an acryl board|substrate, and a polycarbonate board|substrate, etc. can also be used. In that case, it is preferable from the point of process simplification to use the board|substrate with which the ITO electrode etc. for driving a liquid crystal were formed. In the reflective liquid crystal display element, an opaque material such as a silicon wafer can be used as long as it is only a one-side substrate, and a material that reflects light such as aluminum can also be used for the electrode in this case.

Although the application method of a liquid crystal aligning agent is not specifically limited, Industrially, screen printing, offset printing, flexographic printing, the inkjet method, etc. are common. As another coating method, there exist a dip method, the roll coater method, the slit coater method, the spinner method, the spray method, etc., You may use these according to the objective.

After apply|coating a liquid crystal aligning agent on a board|substrate, with heating means, such as a hotplate, a heat circulation type oven, and IR (infrared) type|mold oven, a solvent is evaporated and it bakes. Drying after apply|coating a liquid crystal aligning agent, and a baking process can select arbitrary temperature and time. Usually, in order to fully remove the solvent to contain, it bakes at 50-120 degreeC for 1 to 10 minutes, and then, conditions to bake at 150-300 degreeC for 5 to 120 minutes are mentioned.

Although the thickness of the liquid crystal aligning film after baking is not specifically limited, Since reliability of a liquid crystal display element may fall when too thin, it is preferable that it is 5-300 nm, and 10-200 nm is more preferable.

The liquid crystal aligning film of this invention is suitable as a liquid crystal aligning film of the liquid crystal display element of transverse electric field systems, such as an IPS system and an FFS system, Especially useful as a liquid crystal aligning film of the liquid crystal display element of an FFS system.

<Liquid crystal display element>

After obtaining the board|substrate with a liquid crystal aligning film obtained from the said liquid crystal aligning agent, the liquid crystal display element of this invention manufactures a liquid crystal cell by a known method, and sets it as an element using the liquid crystal cell.

Although an example of the manufacturing method of a liquid crystal cell is given below, this invention is not limited to this.

First, a set of substrates on which electrodes for driving liquid crystals are formed are prepared. This electrode can be, for example, an ITO electrode, and is patterned so that a desired image display can be performed. Moreover, switching elements, such as TFT(Thin Film Transistor), may be formed in each pixel part which comprises image display. A liquid crystal aligning film is formed on this board|substrate as mentioned above.

Next, after arranging, for example, an ultraviolet curable sealing compound in a predetermined place on one substrate among the two substrates on which the liquid crystal aligning film was formed, and further arranging the liquid crystal at several predetermined points on the surface of the liquid crystal aligning film, A liquid crystal cell is obtained by irradiating an ultraviolet-ray to the whole surface of a board|substrate and hardening a sealing compound, after spreading a liquid crystal on the liquid crystal aligning film whole surface by bonding and crimping|bonding the other board|substrate so that a liquid crystal aligning film may oppose.

Or, as a process after forming a liquid crystal aligning film on a board|substrate, when arranging a sealing compound in a predetermined place on one board|substrate, after forming the opening part which can be filled with a liquid crystal from the outside, and bonding a board|substrate together without arranging a liquid crystal A liquid crystal material is inject|poured in the liquid crystal cell through the opening part provided in , sealing compound, then, this opening part is sealed with an adhesive agent, and a liquid crystal cell is obtained. A vacuum injection method may be sufficient for injection|pouring of a liquid crystal material, and the method using capillary phenomenon in air|atmosphere may be sufficient.

In any of said methods, in order to ensure the space with which the liquid crystal material is filled in a liquid crystal cell, a columnar projection is formed on one board|substrate, a spacer is spread|dispersed on one board|substrate, or a spacer is mixed in a sealing compound. Or, it is preferable to take measures such as a combination of these.

Examples of the liquid crystal material include a nematic liquid crystal and a smectic liquid crystal, and among them, a nematic liquid crystal is preferable, and either a positive liquid crystal material or a negative liquid crystal material may be used. Next, a polarizing plate is installed. Specifically, it is preferable to affix a pair of polarizing plates to the surface on the opposite side to the liquid crystal layer of two board|substrates.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows an example of a transverse electric field liquid crystal display element, and is an example of an IPS mode liquid crystal display element.

In the transverse electric field liquid crystal display element 1 illustrated in FIG. 1, between the comb-tooth electrode substrate 2 provided with the liquid crystal aligning film 2c, and the counter substrate 4 provided with the liquid crystal aligning film 4a, liquid crystal ( 3) is pinched. The comb-tooth electrode substrate 2 includes a substrate 2a, a plurality of linear electrodes 2b formed on the substrate 2a and arranged in a comb-tooth shape, and a linear electrode ( It has the liquid crystal aligning film 2c formed so that 2b) might be covered. The counter substrate 4 has the base material 4b and the liquid crystal aligning film 4a formed on the base material 4b. At least any of the liquid crystal aligning film (2c) and the liquid crystal aligning film (4a) is the liquid crystal aligning film of this invention.

In this transverse electric field liquid crystal display element 1, when a voltage is applied to the linear electrode 2b, as shown by the electric force line L, an electric field will generate|occur|produce between the linear electrodes 2b.

2 : is a schematic sectional drawing which shows the other example of a transverse electric field liquid crystal display element, and is an example of an FFS mode liquid crystal display element.

In the transverse electric field liquid crystal display element 1 illustrated in FIG. 2, between the comb-tooth electrode substrate 2 provided with the liquid crystal aligning film 2h, and the counter substrate 4 provided with the liquid crystal aligning film 4a, liquid crystal ( 3) is pinched. The comb electrode substrate 2 is formed on a substrate 2d, a surface electrode 2e formed on the substrate 2d, an insulating film 2f formed on the surface electrode 2e, and an insulating film 2f, It has the some linear electrode 2g arrange|positioned in , comb-tooth shape, and the liquid crystal aligning film 2h formed so that the linear electrode 2g might be covered on the insulating film 2f. The counter substrate 4 has the base material 4b and the liquid crystal aligning film 4a formed on the base material 4b. At least any of the liquid crystal aligning film (2h) and the liquid crystal aligning film (4a) is the liquid crystal aligning film of this invention.

In this transverse electric field liquid crystal display element 1, when a voltage is applied to the surface electrode 2e and the linear electrode 2g, as shown by the electric force line L, between the surface electrode 2e and the linear electrode 2g An electric field is generated.

Example

Hereinafter, although an Example etc. are given and demonstrated concretely about this invention, this invention is not limited to these Examples. In addition, the abbreviation of a compound and a solvent and the characteristic evaluation method are as follows.

NMP: N-methyl-2-pyrrolidone

GBL: γ-butyrolactone

BCS : Butyl Cellosolve

DA-1 to DA-9: a compound of the following structural formula

CA-1, CA-2: a compound of the following structural formula

AD-1, AD-2: a compound of the following structural formula

[Formula 10]

[Formula 11]

[Formula 12]

[Viscosity Measurement]

In the following synthesis examples, the viscosity of the polymer solution was determined using an E-type viscometer TVE-22H (manufactured by Toki Industries, Ltd.), sample amount 1.1 mL, cone rotor TE-1 (1°34', R24), temperature 25°C was measured in

<Synthesis of polymer>

(Synthesis Example 1)

In a 5000 mL separable flask equipped with a stirring device and a nitrogen inlet tube, DA-1 (99.63 g, 500 mmol), DA-2 (106.64 g, 500 mol), and DA-3 (74.60 g, 250 mmol), then NMP (3663.6 g) was added and stirred while sending nitrogen to dissolve. After adding CA-1 (228g, 1163mmol) and NMP (915.8g), stirring this solution, it stirred at 23 degreeC for 2 hours, and the NMP solution of the polyamic acid (PAA-A1) was obtained. The viscosity of this polyamic-acid solution was 91 mPa*s.

(Synthesis Example 2)

To a 100 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, DA-4 (0.54 g, 4.99 mmol), DA-5 (1.83 g, 7.49 mmol), DA-6 (2.40 g, 7.49) mmol) and DA-7 (1.99 g, 4.99 mmol) were added, followed by addition of NMP (68.43 g), followed by stirring while sending nitrogen to dissolve. After adding CA-2 (5.31 g, 23.7 mmol) and NMP (20.12 g) while stirring this solution, the solution of polyamic acid (PAA-B1) was obtained by stirring on 50 degreeC conditions for 12 hours further. The viscosity of this polyamic-acid solution was 402 mPa*s.

(Synthesis Example 3)

In a 3000 mL separable flask equipped with a stirring device and a nitrogen inlet tube, DA-4 (17.3 g, 160 mmol), DA-5 (58.6 g, 240 mmol), DA-6 (76.9 g, 240) mmol), and DA-8 (54.6 g, 160 mmol) were added, followed by addition of NMP (1944 g) and stirred to dissolve while sending nitrogen. After adding CA-2 (171 g, 764 mmol) and NMP (833 g) while stirring this solution, the solution of polyamic acid (PAA-B2) was obtained by stirring on 50 degreeC conditions for 12 hours further. The viscosity of this polyamic-acid solution was 426 mPa*s.

(Comparative Synthesis Example 1)

DA-1 (4.14 g, 20.78 mmol), and DA-9 (1.03 g, 5.20 mmol) were added to a 100 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, and then NMP (71.22 g) was added and stirred while sending nitrogen to dissolve. After adding CA-1 (4.72 g, 24.1 mmol) and NMP (10 g) while stirring this solution, it stirred at 23 degreeC for 2 hours, and obtained the solution of polyamic acid (PAA-C1). The viscosity of this polyamic-acid solution was 130 mPa*s.

(Comparative Synthesis Example 2)

DA-1 (3.99 g, 20.03 mmol) and DA-3 (1.49 g, 4.99 mmol) were added to a 100 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, followed by NMP (71.91) g) was added and stirred while sending nitrogen to dissolve. After adding CA-1 (4.51 g, 23.00 mmol) and NMP (10 g), stirring this solution, it stirred at 23 degreeC for 2 hours, and obtained the solution of polyamic acid (PAA-C2). The viscosity of this polyamic-acid solution was 134 mPa*s.

(Comparative Synthesis Example 3)

Acetic anhydride and pyridine were added to the solution of the polyamic acid (PAA-B2) obtained by carrying out similarly to the synthesis example 3, and it was made to react at 55 degreeC for 3 hours. The reaction solution was poured into methanol, and the resulting precipitate was separated by filtration. Methanol wash|cleaned this deposit, it dried under reduced pressure at 60 degreeC, and the powder of polyimide (SPI-1) was obtained. The imidation rate of this polyimide was 66%. NMP and GBL were added to the powder of the obtained polyimide (SPI-1), it stirred at 70 degreeC for 20 hr, and it was made to melt|dissolve, and the solution of the polyimide (SPI-1) was obtained.

(Examples and Comparative Examples)

The liquid crystal aligning agent of the composition shown below by mixing the solution of the polymer obtained by Synthesis Examples 1-3 and Comparative Synthesis Examples 1-3, AD-1, AD-2, and the solvent shown in Table 1, and stirring at room temperature for 2 hours was obtained (the number at the bottom indicates mass%).

The FFS drive liquid crystal cell was manufactured in the procedure shown below using the liquid crystal aligning agent obtained by making it above, and characteristic evaluation was performed.

[Configuration of FFS-driven liquid crystal cell]

The liquid crystal cell for the fringe field switching (FFS) mode is a first glass substrate on which a FOP (Finger on Plate) electrode layer comprising a planar common electrode - an insulating layer - a comb-shaped pixel electrode is formed on the surface. And the 2nd glass substrate in which the ITO film|membrane for antistatic is formed in the back surface and the columnar spacer of 4 micrometers in height was made into 1 set. The pixel electrode has a comb-tooth shape in which a plurality of electrode elements with a width of 3 μm in which the central portion is bent at an inner angle of 160° are arranged parallel to each other with an interval of 6 μm, and one pixel has a shape of a plurality of electrode elements. It has a 1st area|region and a 2nd area|region with the line connecting a bending part as a boundary.

Moreover, the liquid crystal aligning film formed in a 1st glass substrate orientation-processes so that the direction which divides the inner angle of a pixel bending part into equal parts, and the orientation direction of a liquid crystal may be orthogonal, When the liquid crystal aligning film formed in a 2nd glass substrate manufactures a liquid crystal cell It orientation-processes so that the orientation direction of the liquid crystal on a 1st glass substrate and the orientation direction of the liquid crystal on a 2nd glass substrate may correspond.

[Production of liquid crystal cell]

After filtering a liquid crystal aligning agent with the filter with a hole diameter of 1.0 micrometer, it spin-coated to each of the said board|substrate with an electrode (1st glass substrate), and a counter board|substrate (2nd glass substrate). Subsequently, after drying for 5 minutes on an 80 degreeC hotplate, it baked at 230 degreeC for 20 minutes, and obtained the polyimide film|membrane on each board|substrate as a 100-nm-thick coating film. 300 mJ/cm 2 of ultraviolet rays having a wavelength of 254 nm linearly polarized with an extinction ratio of 26:1 were irradiated to this coating film surface through a polarizing plate. Moreover, this board|substrate was baked at 230 degreeC for 20 minute(s), and the board|substrate with a liquid crystal aligning film was obtained.

Next, the sealing compound was printed on one side of the board|substrate with a liquid crystal aligning film of the said set, and the other board|substrate was bonded so that a liquid crystal aligning film surface might face, and the sealing compound was hardened and the empty cell was manufactured. A liquid crystal (Merck Corporation make, MLC-3019) was vacuum-injected into this empty cell at normal temperature by the reduced pressure injection method, the injection port was sealed, and the FFS drive liquid crystal cell was obtained. Then, after heating the obtained liquid crystal cell at 120 degreeC for 1 hour and leaving it to stand overnight, it was used for each evaluation.

<Stability evaluation of liquid crystal orientation>

About the FFS drive liquid crystal cell manufactured above, the alternating voltage of +/-5V was applied at 60 Hz in a 60 degreeC constant temperature environment for 120 hours. Then, it was set as the state made short between the pixel electrode of a liquid crystal cell, and a counter electrode, and it was left to stand at room temperature as it is for one day.

About the liquid crystal cell which performed the said process, the shift|offset|difference of the orientation direction of the liquid crystal of the 1st area|region of a pixel, and the orientation direction of the liquid crystal of a 2nd area|region in a voltage unapplied state was computed as an angle.

Specifically, a liquid crystal cell is installed between two polarizing plates arranged so that the polarization axes are orthogonal to each other, the backlight is turned on, and the arrangement angle of the liquid crystal cell is adjusted so that the transmitted light intensity of the first region of the pixel is the smallest, and then The rotation angle required when the liquid crystal cell is rotated so that the transmitted light intensity of the second region of the pixel is the smallest was obtained.

It can be said that stability of a liquid-crystal orientation is so favorable that the value of this rotation angle is small. When the rotation angle maintained 0.20 degrees or less, stability of the liquid-crystal orientation was evaluated as "favorable", and when it was more than 0.20 degree|times, it defined as "poor" and evaluated.

<Evaluation of flicker occurring during operation>

The liquid crystal cell prepared above was installed between two polarizing plates arranged so that the polarization axes were perpendicular to each other, the LED backlight was turned on in a state where no voltage was applied, and the arrangement angle 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 the alternating voltage with a frequency of 30 Hz to this liquid crystal cell, and the alternating voltage used as 23 % of relative transmittance was computed as a drive voltage.

In the measurement of flicker, after turning off the lighted LED backlight once and leaving it to block for 72 hours, the LED backlight is turned on again, and at the same time as the backlight lighting starts, an alternating voltage of 30 Hz with a frequency at which the relative transmittance becomes 23% is applied, The liquid crystal cell was driven for 60 minutes to track the flicker amplitude. The flicker amplitude is read by a data acquisition/data logger switch unit 34970A (manufactured by Agilent technologies) connected via a photodiode and an I-V conversion amplifier to the transmitted light of the LED backlight passing through two polarizing plates and a liquid crystal cell between them. did The value calculated using the following formula based on this data was made into the flicker level.

Flicker level (%) = {flicker amplitude / (2 × z)} × 100

In the above formula, z is a value read by the data acquisition/data logger switch unit 34970A for the luminance when driven with an AC voltage having a frequency of 30 Hz at which the relative transmittance is 23%.

Flicker was evaluated by defining "○" when the flicker level was maintained at less than 2% until 60 minutes passed from when the LED backlight was turned on and application of the AC voltage was started. In addition, when the flicker level reached 2% or more in 60 minutes, it was defined as "x" and evaluated.

Evaluation of the flicker level by the above-mentioned method was performed on the temperature condition of the state where the temperature of a liquid crystal cell is 23 degreeC.

<Evaluation result>

The evaluation result of the stability of the liquid crystal orientation implemented about the liquid crystal display element using each liquid crystal aligning agent of the said Example and a comparative example, and the flicker which arises during drive is shown in a table|surface.

The liquid crystal aligning agent of this invention is widely used for liquid crystal display elements of vertical electric field systems, such as a TN system and a VA system, especially transverse electric field systems, such as an IPS system and an FFS system.

1: Transverse electric field liquid crystal display element
2: Comb electrode substrate
2a: description
2b: wire electrode
2c: liquid crystal alignment film
2d: substrate
2e: face electrode
2f: insulating film
2g: wire electrode
2h: liquid crystal alignment film
3: liquid crystal
4: Counter substrate
4a: liquid crystal alignment film
4b: description
L: electric field lines

Claims (4)

The liquid crystal aligning agent containing a following polymer (A) and a polymer (B).
Polymer (A): The diamine component containing the 1st diamine represented by following formula (1), the 2nd diamine represented by Formula (2), and the 3rd diamine represented by Formula (3), and tetracarboxyl which has an alicyclic structure The polyamic acid obtained by polycondensation with acid dianhydride.

(In Formula (3), n1 and n2 each independently represent the integer of 1-3.)
Polymer (B): The diamine component which does not contain simultaneously the 1st diamine represented by the said Formula (1), the 2nd diamine represented by the said Formula (2), and the 3rd diamine represented by the said Formula (3), and tetracar The polyamic acid obtained by polycondensation with acid dianhydride. The method of claim 1,
The liquid crystal aligning agent whose tetracarboxylic dianhydride which has an alicyclic structure in the said polymer (A) is at least 1 sort(s) chosen from the following.

The liquid crystal aligning film obtained from the liquid crystal aligning agent of Claim 1 or 2. The liquid crystal display element which has the liquid crystal aligning film of Claim 3.

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