KR101748928B1 - Composition for liquid crystal alignment and liquid crystal alignment layer - Google Patents

Abstract

상기 식에 있어서, Z는 방향족기를 포함하는 2가 유기기이다.The present invention provides a liquid crystal alignment layer prepared using a liquid crystal alignment layer composition prepared by mixing a first polyamic acid and a second polyamic acid solution prepared using a diamine represented by the following Formula 3, It is possible to provide a liquid crystal display in which the voltage retention rate and the after-image problem due to AC driving are improved.
(3)

In the above formula, Z is a divalent organic group containing an aromatic group.

Description

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal alignment film composition and a liquid crystal alignment film,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device to which an alignment control function is imparted to an alignment film by irradiation of light.

In recent years, as the society has become a full-fledged information age, the display field for processing and displaying a large amount of information has been rapidly developed, and as a flat panel display device having excellent performance of thinning, light weighting and low power consumption, Is replacing a conventional cathode ray tube (CRT).

Generally, the driving principle of a liquid crystal display device utilizes the optical anisotropy and polarization properties of a liquid crystal. Since the liquid crystal has a long structure, it has a directionality in the arrangement of molecules, and the direction of the molecular arrangement can be controlled by artificially applying an electric field to the liquid crystal.

Therefore, when the molecular alignment direction of the liquid crystal is arbitrarily adjusted, the molecular arrangement of the liquid crystal is changed, and light is refracted in the molecular alignment direction of the liquid crystal by optical anisotropy, so that image information can be expressed.

In order to drive the liquid crystal as described above, an alignment film for arranging the initial liquid crystal is required. In general, the alignment film is a polymeric resin for aligning the liquid crystal in a predetermined direction, and is positioned in contact with the liquid crystal as the uppermost layer of the array substrate and the color filter substrate constituting the liquid crystal display device.

The alignment process of the alignment layer may be classified into a contact method using a rubbing cloth or a non-contact method using light (ultraviolet rays).

The physical process using the rubbing cloth can form a fine groove on the surface through friction, and the non-contact method using the light irradiates the surface of the alignment film with light such as UV.

The contact type alignment process using the rubbing cloth has various problems in consideration of the size of the rubbing device used and the cost due to replacement of the rubbing cloth. Recently, a non-contact type process in which the alignment process can be completed only by the step of irradiating light In particular, in the alignment process for forming a plurality of regions having different alignment directions of liquid crystals in a single pixel, an alignment process using light as described above is usefully used.

Various alignment methods have been proposed to solve the above problems. For example, a method using a Langmuir-Blodgett film, a method using UV irradiation, a method using a quadruple deposition of silicon dioxide, a method using a micro-groove formed by photolithography, And a method using an ion beam irradiation.

Among them, the alignment method using ultraviolet (UV) is a method of determining the alignment direction of the polymer by irradiating polarized ultraviolet rays to the polymer film forming the alignment film to cut, create or change the binding of the polymer film in a certain direction.

However, when the AC voltage is continuously applied during the driving of the liquid crystal layer after the ultraviolet ray alignment, an AC after-image may appear in a part of the area, thereby causing a problem that the brightness of the area is increased. Most of these alternating afterimages are recovered over a long period of time even if they remain permanently or are restored.

Such alternating afterimage may appear due to the stress applied to the alignment axis due to the voltage applied to drive the liquid crystal layer.

The change of the orientation axis can be two kinds. First, the direction of the entire director is partially changed. Second, the uniformity of each director is decreased even if the overall sum of the orientation axis directors is the same . There is a problem that a residual image appears or brightness increases due to a decrease in orientation power.

An object of the present invention is to provide an alignment film in which polyimide having excellent optical alignment properties and polyimide having various physical properties are mixed, And to provide a liquid crystal alignment film having improved alignment properties and electrical characteristics by mixing the characteristics of different types of polyimide.

A further object of the present invention is to provide a liquid crystal alignment film having improved afterimage and orientation by alternating-current driving using the above liquid crystal light directing composition.

A further object of the present invention is to provide a liquid crystal display using the liquid crystal alignment film.

A first polyamic acid solution comprising a polyamic acid having a repeating unit represented by the following general formula (1); And

And a second polyamic acid solution containing a polyamic acid having a repeating unit represented by the following formula (2).

 [Chemical Formula 1]

(2)

In the above formula,

X ₁ and X ₂ are each a divalent organic group containing an aromatic, alicyclic or aliphatic group derived from an acid anhydride,

Y ₁ is a divalent organic group derived from a diamine having a structure represented by the following formula (3)

Y ₂ is a divalent organic group derived from a diamine including an aromatic, alicyclic or aliphatic group,

n and m are integers of 1 or more,

(3)

In Formula 3,

       Z is a divalent organic group containing an aromatic group.

According to one embodiment, the first polyamic acid may have an imidization degree of 50% or less in the molecular structure.

According to one embodiment, the blending ratio of the first polyamic acid and the second polyamic acid in the liquid crystal alignment film composition may be 20-80: 80-20, based on the weight of the solid content of the polyamic acid.

According to one embodiment, X ₁ of the first polyamic acid may be a tetravalent organic group derived from at least one tetracarboxylic dianhydride selected from the group consisting of compounds represented by the following formulas (6a) to (6c).

[Chemical Formula 6a]

[Formula 6b]

[Chemical Formula 6c]

In this formula, A represents a single bond, -O-, -CR ₄₆ R ₄₇ -, -C (= O) -, -C (= O) NH-, -S-, -SO ₂ - , And R < ₄₆ > and R < ₄₆ > R ₄₇ are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and a fluoroalkyl group having 1 to 10 carbon atoms.

In one embodiment, Z in Formula 3 may be an aromatic divalent organic group selected from the group consisting of the following Formulas 5a to 5d:

 [Formula 7a]

[Formula 7b]

 [Formula 7c]

 [Formula 7d]

In the _{formula, L 1, L 2, L} 3, L 4, L 5 and L ₆ may be the same or different from each other, and respectively a single bond, -O-, -CO-, -S-, -SO 2 - _{, -C (CH 3) 2 -} , -C (CF 3) 2 -, -CONH-, -COO-, - (CH 2) n 1 -, -O (CH 2) n 2 O-, -OCH 2 - (CH ₃ ) ₂ -CH ₂ O- or COO (CH ₂ ) n ₃ OCO-, and n ₁ , n ₂ and n ₃ are each an integer of 1 to 10.

In one embodiment, the second polyamic acid is a quaternary organic group wherein X < ₂ > is selected from the group consisting of the following 9a to 9k:

According to one embodiment, the Y ₂ of the second polyamic acid is selected from the group consisting of the following 10a to 10k and may be a divalent organic group having a rigid structure:

At least one hydrogen atom in the divalent groups of the general formulas (10a) to (10k) is an alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, isopropyl group, t- butyl group, pentyl group, (For example, a phenyl group, a naphthalenyl group and the like) having 6 to 12 carbon atoms, a sulfonic acid group such as a sulfonic acid group And a carboxylic acid group.

In order to solve the other problems of the present invention,

Applying the liquid crystal alignment film composition to the substrate;

Drying and imidizing the applied liquid crystal alignment film composition;

Irradiating the alignment film composition with light; And

And a step of heat treating the alignment film composition.

In order to solve still another problem of the present invention, there is provided a liquid crystal alignment film produced by the above-described production method.

According to an embodiment, the fluctuation rate of the AC afterglow at room temperature of the liquid crystal alignment layer may be 10 or less.

According to one embodiment, the variation of the high-temperature AC afterimage luminance of the liquid crystal alignment film may be 40 or less.

According to one embodiment, the resistivity of the alignment layer may have a value of 10 ¹⁴ ? · Cm or more.

The present invention can provide a liquid crystal display including the liquid crystal alignment film.

According to the present invention, the liquid crystal display may be IPS or FFS.

The liquid crystal alignment film composition according to the present invention can produce a liquid crystal alignment film in which not only orientation but also various physical properties are improved by mixing a polyamic acid having a structure with improved orientation and the polyamic acid and a different polyamic acid, It is possible to solve the afterimage problem caused by AC driving and to provide a liquid crystal display having a high specific resistance value.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1A is a cross-sectional view showing an orientation film according to Example 1 of the present invention. FIG.
1B is a cross-sectional view showing an orientation film according to Example 2 of the present invention.
1C is a cross-sectional view showing a cross section of an alignment film according to Embodiment 3 of the present invention.
2A is a cross-sectional view showing a cross section of an alignment film according to Embodiment 4 of the present invention.
FIG. 2B is a cross-sectional view showing an orientation film according to Example 5 of the present invention. FIG.
2C is a cross-sectional view showing a cross section of an alignment film according to Embodiment 6 of the present invention.

Hereinafter, the present invention will be described in detail.

The present invention relates to a first polyamic acid solution comprising a polyamic acid having a repeating unit represented by the following formula (1); And

And a second polyamic acid solution containing a polyamic acid having a repeating unit represented by the following formula (2).

 [Chemical Formula 1]

(2)

 In the above formula,

X ₁ and X ₂ are each a divalent organic group containing an aromatic, alicyclic or aliphatic group derived from an acid anhydride,

Y ₁ is a divalent organic group derived from a diamine having a structure represented by the following formula (3)

Y ₂ is a divalent organic group derived from a diamine including an aromatic, alicyclic or aliphatic group,

n and m are integers of 1 or more,

(3)

In Formula 3, Z is a divalent organic group containing an aromatic group.

According to one embodiment, by using the diamine compound of the formula (3) having two imide groups in the structure in the production of polyamic acid and polyimide, the polyamic acid prepared from the polymerization of the diamine and the acid dianhydride of the formula (3) The liquid crystal alignment layer made of the alignment layer composition containing the polyamic acid or the soluble polyimide imidized with the polyamic acid has an imidization degree of 60% or more, preferably 70% or more, Or higher, and the polyimide having an improved alignment property of the alignment film can be provided.

According to the present invention, in Formula 1, X ₁ represents a substituted or unsubstituted C4 to C20 carbon ring group derived from an acid anhydride; A substituted or unsubstituted C4 to C20 condensed polycyclic carbon ring group; And a C6 to C30 non-condensed polycyclic carbon ring group linked to each other by a substituted or unsubstituted linker; and specifically, one of 4-membered organic groups selected from the group consisting of the following formulas (4a) to (4k) Can be an organic group.

[Chemical Formula 4a]

(4b)

[Chemical Formula 4c]

[Chemical formula 4d]

Wherein, L ₁₁ and L ₁₆ is a single _{bond, -O-, -CR 40 R 41 -} , -C (= O) -, -C (= O) NH-, -S-, -SO 2 -, phenyl Halogen, or a combination thereof, wherein R ₄₀ and R ₄₁ are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, an iso (For example, methyl, ethyl, propyl, t-butyl, pentyl and hexyl) and a fluoroalkyl group having 1 to 10 carbon atoms (for example, fluoromethyl, fluoroethyl and trifluoromethyl groups) R ₂₁ to R ₂₇ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms (for example, methyl, ethyl, propyl, isopropyl, t-butyl, pentyl or hexyl) Or a fluoroalkyl group having 1 to 10 carbon atoms (e.g., a fluoromethyl group, a perfluoroethyl group, a trifluoromethyl group ) It can be.

 [Chemical Formula 4e]

[Formula 4f]

[Chemical Formula 4g]

[Chemical Formula 4h]

[Formula 4i]

[Chemical formula 4j]

[Chemical Formula 4k]

In the above formulas (4a) to (4k)

R ₂₁ to R ₃₃ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms (for example, methyl, ethyl, propyl, isopropyl, t-butyl, pentyl or hexyl) To 10 fluoroalkyl groups (e.g., fluoromethyl, perfluoroethyl, trifluoromethyl, etc.).

Preferably, X ₁ is independently selected from the group consisting of tetravalent organic groups represented by the following formulas (5a) to (5t).

In Formula 5t, x is an integer of 1 to 3.

The aromatic, alicyclic and aliphatic tetravalent organic groups represented by the above general formulas (5a) to (5n) may be prepared by subjecting one or more hydrogen atoms present in a tetravalent organic group to an alkyl group having 1 to 10 carbon atoms (e.g., methyl, ethyl, Or a fluoroalkyl group having 1 to 10 carbon atoms (for example, a fluoromethyl group, a perfluoroethyl group, a trifluoromethyl group, etc.) .

According to the present invention, it is more preferable that X ₁ in the formula ( ₁₎ is at least one tetravalent organic group derived from an anhydride selected from the group consisting of the following formulas (6a) to (6c).

[Chemical Formula 6a]

[Formula 6b]

[Chemical Formula 6c]

In this formula, A represents a single bond, -O-, -CR ₄₆ R ₄₇ -, -C (= O) -, -C (= O) NH-, -S-, -SO ₂ - , And R < ₄₆ > and R < ₄₆ > R ₄₇ are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and a fluoroalkyl group having 1 to 10 carbon atoms.

More specifically, the tetravalent organic group derived from the acid anhydride is selected from butanetetracarboxylic dianhydride, pentanetetracarboxylic dianhydride, hexanetetracarboxylic dianhydride, cyclopentane tetracarboxylic dianhydride, Bicyclo-pentane tetracarboxylic dianhydride, cyclopropane tetracarboxylic dianhydride, methylcyclohexane tetracarboxylic dianhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride Rid, 3,4,9,10-perylene tetracarboxylic dianhydride, 4,4'-sulfonyldiphthalic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, Hydride, 1,2,5,6-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 1,4,5,8- Tetracarboxylic dianhydride, 2,3,5,6-pyridine tetracarboxylic dianhydride, m-terphenyl-3,3 ', 4,4'-tetracarboxylic dianhydride, p-terphenyl-3,3 ', 4,4'-tetracarboxylic dianhydride, 4,4'-oxydiphthalic dianhydride, 1,1,1,3,3,3-hexafluoro -2,2-bis [(2,3 or 3,4-dicarboxyphenoxy) phenylpropanedione hydride, 2,2-bis [4- (2,3- or 3,4- dicarboxyphenoxy) Phenyl] propanedialdehyde, 1,1,1,3,3,3-hexafluoro-2,2-bis [4- (2,3- or 4-dicarboxyphenoxy) phenyl] And mixtures thereof.

According to the present invention, the divalent organic group of Y ₁ in Formula 1 may be a divalent organic group derived from the diamine of Formula 3, and in Formula 3, Z may be a divalent organic group containing an aromatic group , A substituted or unsubstituted C6 to C40 arylene group, respectively. Specifically, Z may be a single divalent organic group selected from the group consisting of the following formulas (7a) to (7d).

[Formula 7a]

[Formula 7b]

 [Formula 7c]

 [Formula 7d]

L ₁ , L ₂ , L ₃ , L ₄ , L ₅ and L ₆ may be the same or different and each represents a single bond, -O-, -CO-, -S-, -SO _{2 -, -C (CH 3)} 2 -, -C (CF 3) 2 -, -CONH-, -COO-, - (CH 2) n 1 -, -O (CH 2) n 2 O-, - _{OCH 2 -C (CH 3) 2} -CH 2 O- or a COO (CH ₂₎ n ₃ OCO-, wherein n _1, n ₂ and n ₃ is an integer from 1 to 10, respectively.

Specifically, Z may be selected from the group consisting of divalent organic groups represented by the following formulas (8a) to (8q).

In the general formulas (8a) to (8q), A ₂ represents a single bond, -O-, -C (= O) -, -C (= O) NH-, -S-, -SO ₂ - , And v is an integer of 0 or 1.

In addition, at least one hydrogen atom in the divalent groups of the general formulas (8a) to (8q) may be an alkyl group having 1 to 10 carbon atoms (e.g., a methyl group, an ethyl group, a propyl group, an isopropyl group, a t- butyl group, a pentyl group, , A fluoroalkyl group having 1 to 10 carbon atoms (e.g., a fluoromethyl group, a perfluoroethyl group or a trifluoromethyl group), an aryl group having 6 to 12 carbon atoms (e.g., a phenyl group or a naphthalenyl group) A sulfonic acid group and a carboxylic acid group.

In Formula 2, X ₂ and Y ₂ may be a divalent organic group and a tetravalent organic group selected from the same group as X ₁ and Y _1, and more preferably a group having a rigid structure such as 2 May be an organic group and a quaternary organic group, and may be used to modify various properties such as hardness, imidization rate, and resistivity of the oriented film through mixing with the polyamic acid of formula (1).

According to one embodiment, X ₂ may be a tetravalent organic group selected from the group consisting of the following formulas (9a) to (9k).

In addition, at least one hydrogen atom in the tetravalent groups of the general formulas (9a) to (9k) is an alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, isopropyl group, t-butyl group, pentyl group, , A fluoroalkyl group having 1 to 10 carbon atoms (e.g., a fluoromethyl group, a perfluoroethyl group or a trifluoromethyl group), an aryl group having 6 to 12 carbon atoms (e.g., a phenyl group or a naphthalenyl group) A sulfonic acid group and a carboxylic acid group.

The Y ₂ may be a divalent organic group selected from the group consisting of the following formulas (10a) to (10k).

In addition, at least one hydrogen atom in the divalent groups of the general formulas (10a) to (10k) is an alkyl group having 1 to 10 carbon atoms (e.g., methyl, ethyl, , A fluoroalkyl group having 1 to 10 carbon atoms (e.g., a fluoromethyl group, a perfluoroethyl group or a trifluoromethyl group), an aryl group having 6 to 12 carbon atoms (e.g., a phenyl group or a naphthalenyl group) A sulfonic acid group and a carboxylic acid group.

The dual phase polyimide liquid crystal alignment layer prepared by physically mixing the first polyamic acid and the second polyamic acid produced from the acid dianhydride and the diamine having the above structure has a high first imidation ratio, It is possible to form a liquid crystal alignment layer in which various physical properties that can be derived from the structural characteristics of each polyamic acid are expressed in a complex manner by mixing a second polyamic acid capable of controlling physical properties such as hardness and non- By including the first polyamic acid having a high imidization rate, the problem with afterimage due to AC driving is improved, and the resistivity of the alignment layer can be increased by mixing the first polyamic acid and the second polyamic acid, It is possible to provide an alignment film having improved alignment regulating power by exhibiting a high VHR (voltage holding ratio), and a liquid crystal display It can provide them.

In addition, the liquid crystal alignment layer comprising the above-mentioned double-phase polyimide can easily realize various physical properties because it can modify the physical properties of the liquid crystal alignment layer merely by physical mixing without copolymerization process of each monomer, There is an advantage in that the cost efficiency and economic efficiency according to the process time can be further improved.

The production of the polyamic acid through the polymerization of the acid dianhydride and the diamine can be carried out according to a conventional method for producing a polyamic acid such as solution polymerization. Specifically, it can be produced by dissolving the above-mentioned diamine in an organic solvent, and then adding an acid anhydride to the resultant mixed solution to effect polymerization reaction. At this time, it is preferable to mix the acid dianhydride and the diamine in a molar ratio of 1: 0.1 to 1: 1.1 to obtain the desired molecular weight, mechanical properties and viscosity.

Specifically, it can be produced by dissolving the above-mentioned diamine in an organic solvent, and then adding an acid anhydride to the resultant mixed solution to effect polymerization reaction. At this time, the reaction may be carried out under anhydrous conditions, and the temperature during the polymerization reaction may be -10 to 50 ° C, preferably 0 to 40 ° C. Specific examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; Aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; Ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether , Glycol ethers (cellosolve) such as dipropylene glycol diethyl ether and triethylene glycol monoethyl ether; Examples of the solvent include ethyl acetate, butyl acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether acetate, ethanol, propanol, ethylene glycol, propylene glycol, N-dimethylacetamide (DMAc), N, N-diethylacetamide, dimethylformamide (DMF), diethylformamide (DEF) , N-ethylpyrrolidone (NEP), 1,3-dimethyl-2-imidazolidinone, N, N-dimethylmethoxyacetamide, dimethylsulfoxide, pyridine, dimethylsulfone, hexamethylphosphoramide, tetra (2-methoxyethyl) ether, 1,2-bis (2-methoxyethyl) ether, 1,2-dimethoxyethane, Methoxyethoxy) ethane, bis [2- (2-methoxyethoxy)] ether and Mixture to be used is selected from the group consisting of.

In the case of synthesizing the polyamic acid or polyimide of the present invention, in order to inactivate the excess polyamino group or acid anhydride group, a terminal endblock which encapsulates the end of the polyimide by reacting the molecular end with a dicarboxylic anhydride or a monoamine Can be added.

Examples of the dicarboxylic anhydride used for sealing the ends of the polyimide or polyamic acid include phthalic anhydride, 2,3-benzophenone dicarboxylic anhydride, 3,4-benzophenone dicarboxylic anhydride, 2,3-dicarboxyphenylphenyl Biphenyldicarboxylic anhydride, 3,4-biphenyldicarboxylic anhydride, 2,3-dicarboxyphenylphenylsulfonic anhydride, 3,4-dicarboxyphenylphenylsulfonic anhydride, 2,3-di Carboxyphenylphenylsulfide anhydride, 1,2-naphthalenedicarboxylic anhydride, 2,3-naphthalenedicarboxylic anhydride, 1,8-naphthalenedicarboxylic anhydride, 1,2-anthracenedicarboxylic anhydride, 2,3-anthracenedicarboxylic anhydride, Anhydride, 1,9-anthracenedicarboxylic anhydride, and the like. These dicarboxylic anhydrides may be those having a group which is not reactive with an amine or a dicarboxylic anhydride in the molecule.

Examples of the monoamines include aniline, o-toluidine, m-toluidine, p-toluidine, 2,3-xylidine, 2,4-xylidine, 2,5- Chloro-aniline, p-chloroaniline, o-nitroaniline, o-bromoaniline, m-bromoaniline, Aniline, o-nitroaniline, m-nitroaniline, p-nitroaniline, o-aminophenol, m-aminophenol, p-aminophenol, o-anilidine, m- Aminobenzonitrile, p-aminobenzonitrile, 2-aminobenzonitrile, p-aminobenzonitrile, p-aminobenzonitrile, Aminophenoxyphenyl ether, 4-aminophenolphenyl ether, 2-aminobenzophenone, 3-aminobenzophenone, 4-aminobenzophenone, - aminobenzophenone, 2-aminophene Aminophenolphenylsulfone, 4-aminophenolphenylsulfone,? -Naphthylamine,? -Naphthylphenylsulfone, 3-aminophenolphenylsulfone, Amino-1-naphthol, 5-amino-1-naphthol, 5-amino-1-naphthol, Naphthol, 7-amino-2-naphthol, 8-amino-2-naphthol, 1-aminoanthracene, 2-aminoanthracene and 9-aminoanthracene. These monoamines may have a group which is not reactive with an amine or a dicarboxylic anhydride in the molecule.

Examples of the isocyanate include monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate.

As a method for further encapsulating the aromatic diamine compound and the tetracarboxylic acid dianhydride and the terminal of the obtained polyimide by using the terminal sealing agent, the tetracarboxylic acid dianhydride and the diamine are reacted and then the terminal sealing agent is added to continue the reaction A method in which a diamine adduct is reacted with a dicarboxylic anhydride end capping agent followed by addition of a tetracarboxylic acid dianhydride and the reaction is further continued, a method in which a monoamine end-capping agent is added to a tetracarboxylic acid dianhydride, A method in which the reaction is further continued, a method in which a tetracarboxylic acid dianhydride, a diamine, and the terminal sealing agent are simultaneously added and reacted.

The end-capping agent may be added in an amount of 20 parts by weight or less, preferably 1 to 10 parts by weight, more preferably 1 to 5 parts by weight based on 100 parts by weight of the tetracarboxylic dianhydride and the diamine.

The polyamic acid contained in the liquid crystal aligning composition of the present invention may have a weight average molecular weight of 10,000 to 500,000, respectively. In addition, when the imidization proceeds, the glass transition temperature of the soluble polyimide may be in the range of 200 to 350 占 폚. If the weight average molecular weight of the polyamic acid or polyimide is less than 50,000, the thermal stability, chemical resistance, etc. of the alignment film may be reduced. When the weight average molecular weight of the polyamic acid or the polyimide exceeds 500,000, the viscosity of the polyamic acid or the polyimide may be too high to form a uniform film due to poor printability.

As the solvent included in the liquid crystal aligning composition according to one embodiment of the present invention, any solvent that can dissolve the polyamic acid and / or polyimide according to one embodiment of the present invention may be used.

The solvent is selected from the group consisting of 1,3-dimethyl-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy- N-ethylpyrrolidone (NEP) gamma-butyrolactone (GBL), dimethylformamide (DMF), diethylformamide (DEF), dimethylacetamide (DMAc), dimethylacetamide (DEAc), tetrahydrofuran (THF), 2-butyl cellusolve and the like, or metacresol, phenol, halogenated phenol and the like can be used.

The solvent may further include alcohols, ketones, esters, ethers, hydrocarbons, or halogenated hydrocarbons, which are poor solvents, in an appropriate ratio within the range in which the soluble polyimide polymer is not precipitated. The poor solvent may lower the surface energy of the liquid crystal aligning agent and improve the spreadability and flatness upon application to a substrate.

The poor solvent may be used in an amount of 1 to 80 parts by weight, preferably 10 to 60 parts by weight, and more preferably 10 to 40 parts by weight based on 100 parts by weight of the total solvent.

Specific examples of the poor solvent include methanol, ethanol, 2-butoxyethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, acetone, methyl ethyl ketone, cyclohexanone, And examples thereof include methyl, ethyl acetate, butyl acetate, diethyl carbonate, butyl cellulosic, malonic acid ester, diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol phenyl ether, ethylene glycol phenyl methyl ether, Ethyl ether, ethylene glycol dimethylethyl, diethylene glycol dimethylethyl, diethylene glycol ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethylene Glycol methyl ether acetate, Hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2- (2-hydroxypropyl) Methyl propionate, methyl 3-ethoxypropionate, methyl methoxybutanol, ethyl methoxybutanol, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, Dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, toluene, , Xylene, and combinations thereof.

The solvent is not affected by the surface of the substrate during the coating process of the liquid crystal wide-angle light spreading composition, so that uniformity of the film can be appropriately maintained, an appropriate viscosity can be maintained, and uniformity of the film formed during the coating process due to high viscosity can be prevented And can exhibit an appropriate transmittance.

The temperature for dissolving the polyamic acid and the polyamic acid salt in the solvent is 0 to 100 캜, more preferably 15 to 50 캜.

The total concentration of the polyamic acid salt and the polyamic acid solid content may be in the range of 1 to 20 parts by weight based on 100 parts by weight of the liquid crystal alignment film composition, and may be in a range for proper liquid crystal alignment effect, application property and viscosity property of the composition.

Further, according to the present invention, the blending ratio of the solution containing the polyamic acid salt and the solution containing the polyamic acid is adjusted to a composition ratio of 20 to 80: 80 to 20 based on the mass of the solid content of the polyamic acid salt and the polyamic acid And it may be preferable that the polyamic acid salt and the polyamic acid are mixed in the respective solution states.

The liquid crystal aligning agent according to an embodiment of the present invention may further include an epoxy compound, a silane coupling agent, a surfactant, or the like.

Examples of the functional silane-containing compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- 2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3- Ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-tri Methoxysilylpropyl triethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl- 3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate , N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl- N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, and the like.

The silane coupling agent or the surfactant can improve the adhesion to the substrate and improve the flatness and the film coatability.

Examples of the epoxy crosslinking agent include polyethylene glycol diglycidyl ether, diglycidylorthotoluidine, 1,3-bis (N, N'-diglycidylaminomethyl) cyclohexane, N, N, N ', N Tetraglycidyl-4,4'-diaminodiphenylmethane (TGDDM), N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylethane, N, N , N ', N'-tetraglycidyl-4,4'-diaminodiphenyl propane, N, N, N', N'-tetraglycidyl- , N, N ', N'-tetraglycidyl-4,4'-diaminobenzene, and the like, but are not limited thereto.

The epoxy compound is used for improving reliability and electro-optical property, and this epoxy compound can use one or more epoxy compounds having 2 to 4 epoxy functional groups.

The epoxy compound may be included in an amount of 0.01 to 50 parts by weight based on 100 parts by weight of the liquid crystal aligning agent, and may be included in an amount of 1 to 30 parts by weight. When the content of the epoxy compound is within the above range, reliability and electro-optical characteristics can be improved while exhibiting appropriate printing property and flatness upon application to a substrate.

The liquid crystal alignment film of the present invention is produced using the liquid crystal alignment film composition.

The liquid crystal alignment layer according to the present invention comprises the steps of: applying the liquid crystal alignment layer composition on a substrate;

Drying and imidizing the applied liquid crystal alignment film composition;

Irradiating the liquid crystal alignment film composition with light;

And then heat-treating the liquid crystal alignment layer composition. However, the present invention is not limited to the above-described sequence and method, and may include a step of applying heat to the applied photo-dispersing composition according to a manufacturing method, May be performed simultaneously. That is, ultraviolet rays may be irradiated after heat is applied to the photo-dispersing agent formed on the substrate, but ultraviolet rays may be irradiated while applying heat, and may further include a post-heat treatment step after the photo-alignment.

Among the methods of orienting the alignment film of the liquid crystal display device, the photo alignment method using ultraviolet rays may be a method of determining the alignment direction of the polymer by irradiating part of the bonds of the polymer film forming the alignment film with polarized ultraviolet rays.

The photo-alignment method using ultraviolet light is largely divided into cis and trans isomers, photo isomerization in which the direction of alignment is determined, and alignment of 2,2-monomers with a dimer, Photo dimerization to determine the orientation, photodecomposition to determine the direction of orientation by decomposing molecules with certain bonds, photo rearrangement to determine the orientation direction by changing the arrangement position of molecules, etc. For example. In particular, by irradiating polarized ultraviolet rays, a molecular reaction can be chemically reacted with an orienting agent by cutting, isomerizing, dimerizing or rearranging the molecule, so that the orienting agent can have anisotropic property. As the photo alignment method according to the present invention, a photolytic method may be preferable.

The method of forming an alignment film according to the present invention will be described below in order.

In order to form an alignment film, the above-mentioned photo-dispersing composition is applied onto a substrate.

The method of applying the photo-dispersing composition on the substrate is not particularly limited. For example, a spray method, a roll coating method, a spin coating method, a slit coating method, an extrusion coating method, a curtain coating method, Method or knife coating method may be used, but the method is not limited thereto.

The substrate is not particularly limited as long as it is a substrate having high transparency. Examples of the substrate include polyethylene terephthalate, polyethylene naphthalate, polypropylene, polyethylene, cellulose triacetate, cellulose diacetate, alkyl (meth) acrylate, Acrylic acid ester copolymer, polyvinyl chloride, polyvinyl alcohol, polycarbonate, polystyrene, cellophane, polyvinylidene chloride copolymer, polyamide, polyimide, vinyl chloride vinyl acetate copolymer, polytetrafluoroethylene, Various plastic films such as polyethylene, polypropylene, and fluoroethylene, a glass substrate, and an ITO substrate. The polyimide film is excellent in heat and chemical stability during the curing process and can be easily A separable glass substrate may be preferred.

Next, the drying step of the composition applied on the substrate may vary depending on the amount of ultraviolet irradiation or the monomer constituting the alignment film composition, but it is possible to dry the solvent contained in the alignment film composition by applying heat of about 50 ° C to 100 ° C, Thereafter, the polyamic acid can be imidized by heating at 170 to 300 ° C for 10 to 60 minutes. Alternatively, the polyamic acid may be imidized and dried at 170 to 300 ° C without drying.

Then, light is applied to the photo-dispersion composition applied on the substrate.

Here, the light to be irradiated is polarized ultraviolet light. Ultraviolet rays may be irradiated with light having an appropriate wavelength as necessary, but ultraviolet rays are preferable because ultraviolet rays can supply energy suitable for the reaction related to the photolysis of the precursor having the molecular structure of Formula 8 above. And it may be desirable to irradiate polarized ultraviolet radiation to induce bonding or cutting to have a constant directionality.

After irradiating ultraviolet rays under the above-described irradiation conditions, post-baking may be performed on the alignment agent to form an alignment film.

The post-heat treatment step may vary depending on the ultraviolet irradiation amount or the monomers constituting the photo-dispersing agent, but it is preferable to apply heat of about 100 ° C to 240 ° C.

The post heat treatment process stabilizes the remaining maleimide after heat treatment and irradiation with ultraviolet rays, and stabilizes the energy state by applying energy to other unstable molecular bonds, thereby reducing the fluidity and increasing the heat resistance.

According to an embodiment of the present invention, the resistivity of the alignment layer including the double-phase polyimide may have a value of 10 < ¹⁴ > OMEGA .cm or more, and the alignment layer may have a high specific resistance, : Voltage holding ratio) value, which can improve the display performance of the liquid crystal display by improving the alignment restraining force of the liquid crystal by more effectively maintaining the voltage for driving the liquid crystal.

From the above characteristics, it can be seen that the liquid crystal alignment layer according to the present invention has a structure having a high orientation property of the first polyamic acid, so that the structure in which the second polyamic acid induces a polyimide having a high imidization ratio , It is possible to manufacture a liquid crystal alignment layer having a high imidization ratio and an improved alignment property by mixing the two polyamic acids. From this characteristic, it is possible to obtain a liquid crystal alignment layer in which the afterimage problem due to AC driving is effectively improved .

According to one embodiment, the liquid crystal alignment layer according to the present invention may have a fluctuation rate of AC after-image luminance at room temperature of 10% or less and a fluctuation rate of high-temperature AC after-image luminance of 40% or less, preferably 20% or less.

In addition, the present invention can provide a liquid crystal display including the liquid crystal alignment layer. For example, one of the two photoreaction-induced glass substrates having a liquid crystal alignment layer according to the present invention may be provided with a photoreactive adhesive containing a ball spacer After coating the other glass substrate on the end of the glass substrate, the cell is bonded by irradiating only ultraviolet rays to the portion where the adhesive is applied. Then, the liquid crystal is injected into the completed cell, Can be manufactured.

The liquid crystal display of the present invention including the liquid crystal alignment layer according to the present invention exhibits excellent orientation and can also have excellent electrical characteristics such as a voltage holding ratio (VHR) and a residual accumulated charge amount.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

<Production Example>

Production Example 1: Preparation of CBDA-CBDT polyamic acid

A 250 mL three-necked flask was equipped with a mechanical stirrer and filled with water and ice. Then, 12.96 g (0.034454 mol) of CBDT was dissolved in 180 g of N-methylpyrrolidone (NMP) as a reaction solvent in a nitrogen atmosphere, Lt; / RTI &gt; The temperature of the reactor was adjusted to 0

Lt; 0 &gt; C. 6.223 g (0.031697 mol) of CBDA and 0.817 g (0.005513 mol) of PA as an endcapper reagent were added dropwise while passing nitrogen gas and polymerized at 0 캜 for 24 hours to obtain polyamic acid (CBDA + CBDT + PA). The 10 wt% polyamic acid solution at 30 ° C was measured using a Bruker field viscometer and found to have a viscosity of 730 cP and a weight average molecular weight (Mw) of 41,000 g / mol.

Preparation Example 2: Preparation of BPDA-PDA polyamic acid

A mechanical stirrer was installed in a 250 mL three-necked flask, and water and ice were filled. After 5.37 g (0.049697 mol) of PDA was dissolved in 180 g of N-methylpyrrolidone (NMP) as a reaction solvent in a nitrogen atmosphere, Lt; / RTI &gt; The temperature of the reactor was maintained at 0-10 ° C using ice. (0.047709 mol) of BPDA and 0.59 g (0.003976 mol) of PA as an endcapper reagent were added dropwise while passing nitrogen gas, and polymerization was carried out at 0 캜 for 24 hours to obtain polyamic acid (BPDA + PDA + PA). The 10 wt% polyamic acid solution at 30 ° C was measured using a Bruker field viscometer and found to have a viscosity of 500 cP and a weight average molecular weight (Mw) of 23,000 g / mol.

Preparation Example 3: Preparation of BPDA-CBDT polyamic acid

A mechanical stirring device was installed in a 250 mL three-necked flask, and water and ice were filled. Then, 11.22 g (0.029817 mol) of CBDT was dissolved in 180 g of N-methylpyrrolidone (NMP) as a reaction solvent in a nitrogen atmosphere, Lt; / RTI &gt; The temperature of the reactor was maintained at 0-10 ° C using ice. (0.027432 mol) of BPDA and 0.71 g (0.004771 mol) of PA as an endcapper reagent were added dropwise while passing nitrogen gas, and the mixture was polymerized at 0 캜 for 24 hours to obtain polyamic acid (BPDA + CBDT + PA). The 10 wt% polyamic acid solution at 30 ° C was measured using a Bruker field viscometer and found to have a viscosity of 610 cP and a weight average molecular weight (Mw) of 35,000 g / mol.

Production Example 4: Preparation of CBDA-PDA polyamic acid

6.33 g (0.058583 mol) of paraphenylenediamine (p-PDA) was dissolved in N-methylpyrrolidone (NMP) as a reaction solvent in a nitrogen atmosphere, followed by stirring in a 250 mL three-necked flask equipped with a mechanical stirring apparatus. And the mixture was stirred for 1 hour. The temperature of the reactor was cooled to 0 ° C using ice. (0.003515 mol) of phthalic anhydride (PA) as an endcapper reagent was dropwise added with 11.14 g (0.056826 mol) of cyclobutanetetracarboxylic dianhydride (CBDA) while passing nitrogen gas, and the mixture was stirred at 0 ° C. Polymeric acid (CBDA + PDA + PA) was obtained by polymerization. The 10 wt% polyamic acid solution at 30 ° C was measured using a Bruker field viscometer and found to have a viscosity of 250 cP and a weight average molecular weight (Mw) of 28,000 g / mol.

&Lt; Production of liquid crystal alignment film composition >

Example 1: CBDA-CBDT / BPDA-PDA = 2: 8

1 g of N-methylpyrrolidone (NMP), 14.25 g of gamma-butylolactone (GBL) and 2.75 g of 2-butoxyethanol (2-BE) were added to 20 g of the 10 wt% polyamic acid solution obtained in Production Example 1 obtained in the above- g to prepare a first polyamic acid solution. 1 g of N-methylpyrrolidone (NMP), 14.25 g of gamma-butylolactone (GBL) and 4.75 g of 2-butoxyethanol (2-BE) were added to 20 g of the 10 wt% polyamic acid solution of the obtained Production Example 2, To prepare a second polyamic acid solution. The liquid crystal alignment layer composition was prepared by mixing the polyamic acid solutions at a weight ratio of 20:80 based on the weight of the polyamic acid resin contained in the first polyamic acid solution and the second polyamic acid solution.

Example 2: CBDA-CBDT / BPDA-PDA = 5: 5

A first polyamic acid solution and a second polyamic acid solution were prepared in the same manner as in Example 1. The polyamic acid solution was mixed with the first polyamic acid solution and the second polyamic acid solution at a weight ratio of 50:50 based on the weight of the solid content of the polyamic acid resin to prepare a liquid crystal alignment layer composition.

Example 3: CBDA-CBDT / BPDA-PDA = 8: 2

A first polyamic acid solution and a second polyamic acid solution were prepared in the same manner as in Example 1. The polyamic acid solution was mixed with the first polyamic acid solution and the second polyamic acid solution at a weight ratio of 80:20 based on the weight of the solid content contained in the first polyamic acid solution and the second polyamic acid solution to prepare a liquid crystal alignment layer composition.

Example 4: BPDA-CBDT / CBDA-PDA = 2: 8

1 g of N-methylpyrrolidone (NMP), 14.25 g of gamma-butylolactone (GBL) and 2-butoxyethanol (2-BE) were added to 20 g of the 10 wt% polyamic acid solution prepared in Production Example 3, 4.75 g was added thereto to dilute the first polyamic acid solution. To 20 g of the 10 wt% polyamic acid solution prepared in Production Example 4, 1 g of N-methylpyrrolidone (NMP), 14.25 g of gamma-butylolactone (GBL) and 4.75 g of 2-butoxyethanol To prepare a second polyamic acid solution. The polyamic acid solution was mixed with the first polyamic acid solution and the second polyamic acid solution at a weight ratio of 20:80 based on the weight of the solid content of the polyamic acid resin to prepare a liquid crystal alignment layer composition.

Example 5: BPDA-CBDT / CBDA-PDA = 5: 5

A first polyamic acid solution and a second polyamic acid solution were prepared in the same manner as in Example 4. The polyamic acid solution was mixed with the first polyamic acid solution and the second polyamic acid solution at a weight ratio of 50:50 based on the weight of the solid content of the polyamic acid resin to prepare a liquid crystal alignment layer composition.

Example 6: BPDA-CBDT / CBDA-PDA = 8: 2

A first polyamic acid solution and a second polyamic acid solution were prepared in the same manner as in Example 4. The polyamic acid solution was mixed at a weight ratio of 80:20 based on the weight of the solid content of the polyamic acid resin contained in the first polyamic acid solution and the second polyamic acid solution to prepare a liquid crystal alignment film composition.

Comparative Example 1

1 g of N-methylpyrrolidone (NMP), 14.25 g of gamma-butylolactone (GBL) and 4.75 g of 2-butoxyethanol (2-BE) were added to 20 g of the 10 wt% polyamic acid solution prepared in Preparation Example 1 To prepare a liquid crystal alignment film composition.

Comparative Example 2

1 g of N-methylpyrrolidone (NMP), 14.25 g of gamma-butylolactone (GBL) and 4.75 g of 2-butoxyethanol (2-BE) were added to 20 g of the 10 wt% polyamic acid solution prepared in Preparation Example 2 To prepare a liquid crystal alignment film composition.

Comparative Example 3

To 20 g of the polyamic acid resin prepared in Preparation Example 3 were added 1 g of N-methylpyrrolidone (NMP), 14.25 g of gamma-butylolactone (GBL) and 4.75 g of 2-butoxyethanol (2-BE) To prepare a liquid crystal alignment film composition.

Comparative Example 4

1 g of N-methylpyrrolidone (NMP), 14.25 g of gamma-butylolactone (GBL) and 4.75 g of 2-butoxyethanol (2-BE) were added to 20 g of the 10 wt% polyamic acid solution prepared in Preparation Example 4 To prepare a liquid crystal alignment film solution.

In the above embodiment, each abbreviation represents the following.

CBDA: Cyclobutane tetracarboxylic acid dianhydride

CBDT: Cyclobutadipyrrol tetran

(Cyclobuta [1,2-c: 3,4-c '] dipyrrole-1,3,4,6 (2H, 5H) -tetrahydro-

PDA: phenylenediamine

BPDA: biphenyl dianhydride

<Experimental Example>

Evaluation of Liquid Crystal Orientation Film

A liquid crystal cell was prepared and used for evaluating the liquid crystal alignment property of the liquid crystal alignment film. The manufacture of the liquid crystal cell is as follows.

On the ITO glass substrate of the standardized size, the square ITO shape of 2.0 cm x 2.5 cm and the electrode for the voltage application were patterned by using the photolithography process in order to leave only ITO shape and remove ITO of the other part.

A liquid crystal alignment film including the polyamic acid solution prepared in Example 1 and Comparative Example 1 was applied to the patterned ITO substrate, spin-coated, applied at 2500 rpm for 20 seconds, and cured at 70 ° C and 230 ° C, .

 The ITO substrate having undergone the curing process was exposed to two substrates exposed at a constant angle and a constant energy using an aligner (UIS-S2021J7-YD01, Ushio LPUV), and a square ITO shape Using a UV sealant. A 2 kW deep UV ramp (UXM-2000) was used as the light source during the exposure.

Table 1 shows the results of liquid crystal alignability obtained by visually observing the presence or absence of display defects by driving the IPS liquid crystal cell with a square wave of 5 V and 60 Hz for 24 hours after filling the cells made by such a method with liquid crystal.

The fluctuation rate and specific resistance of the AC after-image of the liquid crystal cell were measured and are shown in Table 1 below.

Good: Fair: Fair: Fair: X: Bad

division Imidization rate (%) Liquid crystal orientation AC residual image at room temperature
Luminance variation
(%) High temperature AC afterimage
Luminance variation
(%) Resistivity
(Ω · cm) Example 1 94 ○ 5 or less below 10 1.7X10 ¹⁵ Example 2 83 ○ 3 or less 9 or less 9.5X10 ¹⁴ Example 3 77 ○ 3 or less 9 or less 5.3X10 ¹⁴ Example 4 55 ○ 4 or less below 10 4.4X10 ¹⁴ Example 5 69 ○ 2 or less 8 or less 5.5X10 ¹⁴ Example 6 86 ○ 2 or less 8 or less 9.3X10 ¹⁴ Comparative Example 1 73 △ 12 or less Less than 50 9.0 X10 ¹³ Comparative Example 2 96 X - - 8.2X10 ¹³ Comparative Example 3 93 △ 15 or less 60 or less 9.2X10 ¹³ Comparative Example 4 49 ○ below 10 Less than 50 2.3 X10 ¹³

As shown in Table 1, the liquid crystal alignment layer comprising the dual phase polyimide according to the present invention can control the imidization ratio of the polyimide by mixing the polyimide having different imidization ratios, When the polyimide having the rate of increase and the rate of the imidization of the polyimide having the low imidation rate are mixed, the variation of the luminance due to the afterimage due to the AC is improved due to the interaction between the polyimides, It is possible to produce a liquid crystal alignment film having a resistivity value significantly higher than that of the liquid crystal alignment film including the polyimide as the component. Therefore, it is possible to more effectively control the afterimage problem and the VHR value by AC driving from the liquid crystal alignment film composition comprising the dual phase polyimide according to the present invention, and thereby, a liquid crystal display having improved performance can be manufactured.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby. something to do. It is therefore intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

Claims (15)

A first polyamic acid solution comprising a polyamic acid having a repeating unit represented by the following formula (1); And
A second polyamic acid solution comprising a polyamic acid having a repeating unit represented by the following formula (2): &lt; EMI ID =
[Chemical Formula 1]

(2)

In the above formula,
X ₁ and X ₂ are a tetravalent organic group containing an aromatic, alicyclic or aliphatic group derived from an acid anhydride, one of X ₁ and X ₂ is derived from the following formula (6a)
[Chemical Formula 6a]

Y ₁ and Y ₂ is an aromatic, alicyclic or being a divalent strange organic derived from a diamine containing an aliphatic, Y ₁ and Y 2 is an organic group derived from a diamine having the _second one to the structures of general formula (3),
(3)

Z is a divalent organic group containing an aromatic group,
n and m are an integer of 1 or more.
delete The method according to claim 1,
Wherein a blending ratio of the first polyamic acid and the second polyamic acid in the liquid crystal alignment film composition is 20 to 80: 80 to 20. The method according to claim 1,
The first to the polyamic acid of the formula X ₁ light to 4 characterized in that the organic group is derived from at least one tetracarboxylic dianhydride selected from the group consisting of compounds represented by the orientation of the liquid crystal alignment layers 6a to 6c composition:
[Chemical Formula 6a]

[Formula 6b]

[Chemical Formula 6c]

In this formula, A represents a single bond, -O-, -CR ₄₆ R ₄₇ -, -C (= O) -, -C (= O) NH-, -S-, -SO ₂ - And R &lt; ₄₆ &gt; and R &lt; ₄₆ &gt; R ₄₇ are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and a fluoroalkyl group having 1 to 10 carbon atoms. The method according to claim 1,
Wherein Z in the formula (3) is an aromatic divalent organic group selected from the group consisting of the following formulas (7a) to (7d): &lt; EMI ID =
[Formula 7a]

[Formula 7b]

[Formula 7c]

[Formula 7d]

In the _{formula, L 1, L 2, L} 3, L 4, L 5 and L ₆ may be the same or different from each other, and respectively a single bond, -O-, -CO-, -S-, -SO 2 - _{, -C (CH 3) 2 -} , -C (CF 3) 2 -, -CONH-, -COO-, - (CH 2) n 1 -, -O (CH 2) n 2 O-, -OCH 2 - (CH ₃ ) ₂ -CH ₂ O- or COO (CH ₂ ) n ₃ OCO-, and n ₁ , n ₂ and n ₃ are each an integer of 1 to 10. The method according to claim 1,
And X ₂ of the second polyamic acid is a tetravalent organic group having a rigid structure selected from the group consisting of the following 9a to 9k:

At least one hydrogen atom in the tetravalent groups of the general formulas (9a) to (9k) is selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, a sulfonic acid group and a carboxylic acid group Lt; / RTI &gt; The method according to claim 1,
Wherein the Y ₂ of the second polyamic acid is selected from the group consisting of the following 10a to 10k and is a divalent organic group having a rigid structure:

At least one hydrogen atom in the divalent groups of formulas (10a) to (10k) is selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, a sulfonic acid group, and a carboxylic acid group Lt; / RTI &gt; The method according to claim 1,
Wherein the solid concentration of the first polyamic acid and the second polyamic acid is 1 to 20 parts by weight based on 100 parts by weight of the total composition of the liquid crystal alignment film composition. Applying the liquid crystal alignment film composition of claim 1;
Drying and imidizing the applied liquid crystal alignment film composition;
Irradiating the alignment film composition with light; And
And heat treating the alignment film composition. A liquid crystal alignment film produced by the method of claim 9. 11. The method of claim 10,
Wherein the liquid crystal alignment layer has a fluctuation rate of AC after-image at room temperature of 10% or less. 11. The method of claim 10,
Wherein the liquid crystal alignment layer has a fluctuation rate of high-temperature AC after-image luminance of 40% or less. 11. The method of claim 10,
Wherein the liquid crystal alignment layer has a specific resistance of 10 &lt; ¹⁴ &gt; [Omega] -cm or more. A liquid crystal display comprising the liquid crystal alignment film according to any one of claims 10 to 13. 15. The method of claim 14,
Wherein the liquid crystal display is an IPS or FFS system.

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