KR102263638B1 - Liquid crystal alignment composition, method of preparing liquid crystal alignment film, and liquid crystal alignment film, liquid crystal display using the same - Google Patents

Abstract

The present invention relates to a liquid crystal aligning agent composition comprising two types of polymers for liquid crystal aligning agents classified according to types of diamine-derived functional groups, a method for manufacturing a liquid crystal aligning film using the same, and a liquid crystal aligning film and a liquid crystal display device using the same.

Description

Liquid crystal aligning agent composition, manufacturing method of liquid crystal aligning film using same, liquid crystal aligning film and liquid crystal display device using same

The present invention relates to a liquid crystal aligning agent composition having excellent liquid crystal alignment, durability and electrical properties when synthesizing a liquid crystal alignment film, and having excellent shielding power through high film density, a method for manufacturing a liquid crystal alignment film using the same, and a liquid crystal alignment film and liquid crystal display device using the same it's about

In the liquid crystal display device, the liquid crystal alignment layer is responsible for aligning the liquid crystal in a predetermined direction. Specifically, the liquid crystal aligning layer serves as a director for the arrangement of liquid crystal molecules, so that when the liquid crystal moves by an electric field to form an image, the liquid crystal aligns to an appropriate direction. In order to obtain uniform brightness and high contrast ratio in the liquid crystal display device, it is essential to uniformly align the liquid crystal.

As one of the methods for aligning liquid crystals in the prior art, a rubbing method in which a polymer film such as polyimide is applied to a substrate such as glass, and the surface is rubbed in a predetermined direction using fibers such as nylon or polyester was used. However, in the rubbing method, fine dust or electrical discharge (ESD) may be generated when the fibers and the polymer film are rubbed, which may cause serious problems in manufacturing the liquid crystal panel.

In order to solve the problem of the rubbing method, recently, a photo-alignment method in which anisotropy (anisotropy) is induced in a polymer film by light irradiation rather than friction, and aligning liquid crystals using this is being studied.

Various materials have been introduced as materials that can be used for the photo-alignment method, and among them, polyimide is mainly used for good overall performance of the liquid crystal alignment layer. Accordingly, after coating in the form of a precursor such as polyamic acid or polyamic acid ester, the polyimide is formed through a heat treatment process at a temperature of 200 ° C. to 230 ° C., and the orientation treatment is performed by performing light irradiation.

However, in order to obtain sufficient liquid crystal alignment by irradiating the polyimide film with light, a lot of energy is required, which makes it difficult to secure actual productivity, and an additional heat treatment process is also required to ensure alignment stability after light irradiation, and the panel Due to the enlargement of the panel, abrasion of the column space (CS) occurred during the manufacturing process, and haze was generated on the surface of the liquid crystal alignment layer, which caused the milky way defect, and there was a limitation in that the performance of the panel could not be sufficiently realized.

In addition, for high-quality driving of the liquid crystal display device, a high voltage holding ratio (VHR) must be exhibited, and polyimide alone has a limit in representing this. In particular, as the demand for low-power displays increases in recent years, liquid crystal aligning agents may affect not only the basic characteristics of liquid crystal alignment, but also electrical characteristics such as afterimages and voltage retention caused by DC/AC voltage. was found

Accordingly, there is a demand for the development of a liquid crystal aligning agent composition capable of implementing improved alignment, durability, and electrical properties.

An object of the present invention is to provide a liquid crystal aligning agent composition having excellent liquid crystal alignment property, durability and electrical properties when synthesizing a liquid crystal alignment film, and having excellent shielding power through a high film density.

Moreover, this invention is for providing the manufacturing method of the liquid crystal aligning film using said liquid crystal aligning agent composition.

The present specification also provides a liquid crystal aligning film using the liquid crystal aligning agent composition and a liquid crystal display device including the same.

In the present specification, a first polymer for a liquid crystal aligning agent comprising at least one repeating unit selected from the group consisting of a repeating unit represented by the following Chemical Formula 1, a repeating unit represented by the following Chemical Formula 2, and a repeating unit represented by the following Chemical Formula 3; And a first repeating unit comprising at least one selected from the group consisting of a repeating unit represented by the following formula (4), a repeating unit represented by the following formula (5), and a repeating unit represented by the following formula (6), and a first repeating unit represented by the following formula (7) a second polymer for a liquid crystal aligning agent comprising a second repeating unit comprising at least one selected from the group consisting of a repeating unit, a repeating unit represented by the following Chemical Formula 8, and a repeating unit represented by the following Chemical Formula 9; A liquid crystal aligning agent composition comprising:

[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

In Formulas 1 to 9, _{at least one of R 1} and R ₂ is an alkyl group having 1 to 10 carbon atoms, the rest is hydrogen, _{and at least one of R 3} and R ₄ is an alkyl group having 1 to 10 carbon atoms, and the rest is hydrogen. , _{at least one of R 5} and R ₆ is an alkyl group having 1 to 10 carbon atoms, the rest is hydrogen,

X ₁ to X ₉ are each independently a tetravalent organic group represented by the following formula (10),

[Formula 10]

In Formula 10, R ₇ to R ₁₂ are each independently hydrogen or an alkyl group having 1 to 6 carbon atoms, L ₁ is a single bond, -O-, -CO-, -COO-, -S-, -SO-, -SO ₂ -, -CR ₁₃ R ₁₄ -, -(CH ₂ ) _Z -, -O(CH ₂ ) _Z O-, -COO(CH ₂ ) _Z OCO-, -CONH-, phenylene or a combination thereof It is any one selected from the group consisting of, wherein in L ₁ R ₁₃ and R ₁₄ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or a haloalkyl group having 1 to 10 carbon atoms, wherein in L ₁ z is 1 to 10 is an integer,

wherein Y ₁ to Y ₃ are each independently a divalent organic group represented by the following Chemical Formula 11,

[Formula 11]

In Formula 11, T is a tetravalent organic group represented by Formula 10, D ₁ and D ₂ are each independently an alkylene group having 1 to 20 carbon atoms, a heteroalkylene group having 1 to 10 carbon atoms, and 3 to 20 carbon atoms. Any one selected from a cycloalkylene group, an arylene group having 6 to 20 carbon atoms, or a heteroarylene group having 2 to 20 carbon atoms,

The Y ₄ to Y ₆ are each independently a divalent organic group represented by the following formula (12),

[Formula 12]

In Formula 12, A is a group 15 element, R ^′ is hydrogen or an alkyl having 1 to 10 carbon atoms, a is an integer from 1 to 3 _{, at least one of Z 1} to Z ₄ is nitrogen, and the remainder is carbon ego,

wherein Y ₇ to Y ₉ are each independently a divalent organic group represented by the following Chemical Formula 13,

[Formula 13]

In Formula 13, Q ₁ to Q ₈ are each independently carbon or nitrogen, L ₂ and L ₄ are each independently one of -CON(R ₁₅ )-, -N(R ₁₆ )CO-, and L ₃ is a single bond, -O-, -CO-, -S-, -SO ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -CONH-, -COO-, -(CH ₂ ) _b -, -O(CH ₂ ) _b O-, -O(CH ₂ ) _b -, -OCH ₂ -C(CH ₃ ) ₂ -CH ₂ O-, -COO-(CH ₂ ) _b -OCO -, or -OCO-(CH ₂ ) _b -COO-, R ₁₅ to R ₁₆ are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms, b is an integer of 1 to 10 each, n is 0 to 8 is the integer of

In the present specification, also, forming a coating film by applying the liquid crystal aligning agent composition to a substrate; drying the coating film; alignment treatment by irradiating light to the coating film immediately after the drying step; and curing the alignment-treated coating film by heat treatment.

In the present specification, there is also provided a liquid crystal aligning film and a liquid crystal display including the same, including an alignment cured product of the liquid crystal aligning composition.

Hereinafter, a liquid crystal aligning agent composition according to a specific embodiment of the present invention, a method of manufacturing a liquid crystal aligning film using the same, a liquid crystal aligning film and a liquid crystal display device using the same will be described in more detail.

In the present specification, when a part "includes" a certain component, this means that other components may be further included rather than excluding other components unless otherwise stated.

In the present specification, the term "substituted" means that another functional group is bonded instead of a hydrogen atom in the compound, and the position to be substituted is not limited as long as the position at which the hydrogen atom is substituted, that is, the position where the substituent is substituted, is not limited, and when two or more substituted , two or more substituents may be the same as or different from each other.

As used herein, the term "substituted or unsubstituted" refers to deuterium; halogen group; cyano group; nitro group; hydroxyl group; carbonyl group; ester group; imid; amide group; amino group; carboxyl group; sulfonic acid group; sulfonamide group; phosphine oxide group; alkoxy group; aryloxy group; alkyl thiooxy group; arylthioxy group; an alkyl sulfoxy group; arylsulfoxy group; silyl group; boron group; an alkyl group; cycloalkyl group; alkenyl group; aryl group; aralkyl group; aralkenyl group; an alkylaryl group; an arylphosphine group; Or N, O, and S atom means that it is substituted or unsubstituted with one or more substituents selected from the group consisting of a heterocyclic group including one or more, or substituted or unsubstituted, in which two or more substituents of the above-exemplified substituents are connected. . For example, "a substituent in which two or more substituents are connected" may be a biphenyl group. That is, the biphenyl group may be an aryl group or may be interpreted as a substituent in which two phenyl groups are connected.

, 또는

는 다른 치환기에 연결되는 결합을 의미한다. In this specification,

, or

means a bond connected to another substituent.

In the present specification, the alkyl group may be linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 1 to 10. According to another exemplary embodiment, the alkyl group has 1 to 6 carbon atoms. Specific examples of the alkyl group include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n -pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl , n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2 -Dimethylheptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl and the like, but are not limited thereto. The alkyl group may be substituted or unsubstituted.

In the present specification, the haloalkyl group refers to a functional group in which a halogen group is substituted with the above-described alkyl group, and examples of the halogen group include fluorine, chlorine, bromine or iodine. The haloalkyl group may be substituted or unsubstituted.

In the present specification, the aryl group is a monovalent functional group derived from arene, and may be, for example, monocyclic or polycyclic. Specifically, the monocyclic aryl group may be a phenyl group, a biphenyl group, a terphenyl group, a stilbenyl group, and the like, but is not limited thereto. The polycyclic aryl group may be a naphthyl group, an anthryl group, a phenanthryl group, a pyrenyl group, a perylenyl group, a chrysenyl group, a fluorenyl group, and the like, but is not limited thereto. The aryl group may be substituted or unsubstituted.

The halogen may be fluorine (F), chlorine (Cl), bromine (Br) or iodine (I).

The group 15 element may be nitrogen (N), phosphorus (P), arsenic (As), tin (Sn), or bismuth (Bi).

Nitrogen oxide is a compound in which a nitrogen atom and an oxygen atom are bonded, and the nitrogen oxide functional group means a functional group including nitrogen oxide in the functional group. As an example of the nitrogen oxide functional group, a nitro group (-NO ₂ ) and the like may be used.

In the present specification, the alkylene group is a divalent functional group derived from an alkane, and has 1 to 20, or 1 to 10, or 1 to 5 carbon atoms. For example, as a linear, branched or cyclic type, it may be a methylene group, an ethylene group, a propylene group, an isobutylene group, a sec-butylene group, a tert-butylene group, a pentylene group, a hexylene group, and the like. One or more hydrogen atoms included in the alkylene group may be substituted with the same substituents as in the case of the alkyl group.

In the present specification, the heteroalkylene group is an alkylene group containing oxygen (O), nitrogen (N) or sulfur (S) as a heteroatom, and has 1 to 10, or 1 to 5 carbon atoms. For example, it may be oxyalkylene or the like. One or more hydrogen atoms included in the heteroalkylene group may be substituted with the same substituents as in the case of the alkyl group.

In the present specification, the cycloalkylene group is a divalent functional group derived from cycloalkane, and has 3 to 20, or 3 to 10 carbon atoms. For example, cyclopropylene, cyclobutylene, cyclopentylene, 3-methylcyclopentylene, 2,3-dimethylcyclopentylene, cyclohexylene, 3-methylcyclohexylene, 4-methylcyclohexylene, 2 ,3-dimethylcyclohexylene, 3,4,5-trimethylcyclohexylene, 4-tert-butylcyclohexylene, cycloheptylene, cyclooctylene, and the like, but is not limited thereto. The cycloalkylene group may be substituted or unsubstituted.

In the present specification, the arylene group is a divalent functional group derived from arene, and may be monocyclic or polycyclic, and may have 6 to 20, or 6 to 10 carbon atoms. For example, it may be a phenylene group, a biphenylene group, a terphenylene group, a stilbenylene group, a naphthylenyl group, but is not limited thereto. One or more hydrogen atoms included in the arylene group may be substituted with the same substituents as in the case of the alkyl group.

In the present specification, the hetero arylene group has 2 to 20, or 2 to 10, or 6 to 20 carbon atoms. As an arylene group containing O, N or S as a heteroatom, one or more hydrogen atoms included in the hetero arylene group may be substituted with the same substituents as in the case of the alkyl group, respectively.

In this specification, the weight average molecular weight means the weight average molecular weight in terms of polystyrene measured by the GPC method. In the process of measuring the weight average molecular weight in terms of polystyrene measured by the GPC method, a commonly known analyzer and a detector such as a differential refraction detector and a column for analysis may be used, and the temperature at which it is normally applied Conditions, solvents, and flow rates can be applied. As a specific example of the measurement conditions, using a Waters PL-GPC220 instrument using a Polymer Laboratories PLgel MIX-B 300 mm length column, the evaluation temperature is 160 ° C., dimethylformamide (DMF) and tetrahydrofuran (THF) was used as a solvent by mixing in a weight ratio of 50wt%:50wt%, the flow rate was 1mL/min, the sample was prepared at a concentration of 10mg/10mL, and then supplied in an amount of 200μL, an assay formed using a polystyrene standard The value of Mw can be calculated using the curve. The molecular weight of the polystyrene standard was 2,000 / 10,000 / 30,000 / 70,000 / 200,000 / 700,000 / 2,000,000 / 4,000,000 / 10,000,000.

In the present specification, a multivalent functional group is a residue in a form in which a plurality of hydrogen atoms bonded to an arbitrary compound are removed, and may include, for example, a divalent functional group, a trivalent functional group, and a tetravalent functional group. For example, the tetravalent functional group derived from cyclobutane refers to a residue in which 4 hydrogen atoms bonded to cyclobutane are removed.

In the present specification, a direct bond or a single bond means that no atom or group of atoms is present at the corresponding position, and thus is connected by a bonding line. Specifically, it means a case in which a separate atom does not exist in the portion represented by _{L 1} , L _{2 in the formula.}

The liquid crystal aligning agent composition according to the present invention is a polyimide precursor derived from a diamine having a specific structure containing a diamine having an asymmetric pyridine structure, a hydrazide group, etc. together with the first liquid crystal aligning agent polymer which is a partially imidized polyimide precursor. It is characterized in that it contains a polymer for a second liquid crystal aligning agent which is phosphorus.

That is, the liquid crystal aligning agent composition according to the present invention, together with the first polymer for liquid crystal aligning agent, which is a partially imidized polyimide precursor, a diamine compound having a specific structure containing a nitrogen atom, etc. A polymer for a second liquid crystal aligning agent, which is a polymer comprising the second repeating unit of Chemical Formulas 7 to 9, prepared from a reactant including the first repeating unit of 6 and a diamine compound having a specific structure containing a hydrazide group, etc. Its main feature is that

When using a conventional polyimide as a liquid crystal aligning film, a polyimide precursor, polyamic acid or polyamic acid ester is applied and dried to form a coating film, then converted to polyimide through a high-temperature heat treatment process, and light irradiation is performed here and orientation treatment was performed. However, in order to obtain sufficient liquid crystal alignment by irradiating the polyimide film with light, a lot of light irradiation energy is required, and an additional heat treatment process is also performed to secure alignment stability after light irradiation. Such a lot of light irradiation energy and additional high-temperature heat treatment process are very disadvantageous in terms of process cost and process time, so there is a limit to be applied to actual mass production process.

In the present invention, by using the first polymer for liquid crystal aligning agent containing a partially imidized polyimide structure in the molecular structure, the light irradiation energy can be greatly reduced, and a simple process including one heat treatment process A liquid crystal aligning film excellent in degree orientation and stability can be manufactured.

In addition, in the present invention, when the first repeating units of Chemical Formulas 4 to 6 prepared from a diamine compound having an asymmetric pyridine structure containing a nitrogen atom are included in the polymer for liquid crystal aligning agents, the liquid crystal aligning film prepared from such a polymer is formed from a high voltage at high temperature The invention has been completed by confirming that it can have a retention rate, improve the reduction of the contrast ratio or the afterimage phenomenon, as well as improve the orientation stability and mechanical strength of the alignment film due to thermal stress.

The present inventors, together with the first repeating unit of Chemical Formulas 4 to 6, provide a second repeat of Chemical Formulas 7 to 9 prepared from a diamine compound having a specific structure containing a hydrazide group as described above in the polymer for liquid crystal aligning agent. When the unit is included, the technical effect of increasing the film density is obtained because hydrogen bonds are formed between the repeating units as the amide bond is present in the repeating unit, and the invention was completed.

1. Liquid crystal aligning agent composition

According to an embodiment of the present invention, a first liquid crystal alignment comprising at least one repeating unit selected from the group consisting of a repeating unit represented by Chemical Formula 1, a repeating unit represented by Chemical Formula 2, and a repeating unit represented by Chemical Formula 3 dissolving polymers; And a first comprising at least one selected from the group consisting of one or more repeating units selected from the group consisting of the repeating unit represented by Chemical Formula 4, the repeating unit represented by Chemical Formula 5, and the repeating unit represented by Chemical Formula 6 a second repeating unit comprising a repeating unit, and a second repeating unit comprising at least one selected from the group consisting of a repeating unit represented by Chemical Formula 7, a repeating unit represented by Chemical Formula 8, and a repeating unit represented by Chemical Formula 9 polymers for liquid crystal aligning agents; A liquid crystal aligning agent composition comprising a may be provided.

Specifically, the first polymer for a liquid crystal aligning agent may include one of the repeating unit represented by Chemical Formula 1, the repeating unit represented by Chemical Formula 2, the repeating unit represented by Chemical Formula 3, or a mixture of two thereof, or Mixtures of all three of these may be included.

The first repeating unit included in the second polymer for liquid crystal aligning agent is a polyimide repeating unit represented by Chemical Formula 4, a polyamic acid ester repeating unit represented by Chemical Formula 5, and a polyamic acid repeating unit represented by Chemical Formula 6 and at least one selected from the group consisting of, the second repeating unit is a polyimide repeating unit represented by Chemical Formula 7, a polyamic acid ester repeating unit represented by Chemical Formula 8, and a polyamic acid repeating unit represented by Chemical Formula 9 It may include one or more selected from the group consisting of.

Specifically, the first repeating unit may include one or a mixture of two or three of the repeating unit represented by Chemical Formula 4, the repeating unit represented by Chemical Formula 5, and the repeating unit represented by Chemical Formula 6 Mixtures of both may be included.

In addition, the second repeating unit may include one or a mixture of two or all of the repeating unit represented by Chemical Formula 7, the repeating unit represented by Chemical Formula 8, and the repeating unit represented by Chemical Formula 9. may include a mixture of

Specifically, in the first polymer for the liquid crystal aligning agent, and the second polymer for the liquid crystal aligning agent in the liquid crystal aligning agent composition according to the embodiment, X ₁ to X ₉ are each independently a tetravalent organic group represented by Formula 10 can Wherein X ₁ to X ₉ may be a functional group derived from polyamic acid, polyamic acid ester, or tetracarboxylic acid dianhydride compound used in synthesizing polyimide.

In Formula 10, R ₇ to R ₁₂ are each independently hydrogen or an alkyl group having 1 to 6 carbon atoms, L ₁ is a single bond, -O-, -CO-, -COO-, -S-, -SO-, -SO ₂ -, -CR ₁₃ R ₁₄ -, -(CH ₂ ) _Z -, -O(CH ₂ ) _Z O-, -COO(CH ₂ ) _Z OCO-, -CONH-, or any one selected from phenylene one, and in L ₁ , R ₁₃ and R ₁₄ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or a haloalkyl group having 1 to 10 carbon atoms, and in L ₁ , z is an integer of 1 to 10.

More preferably, X ₁ to X ₉ are each independently an organic group of the following formula 10-1 derived from cyclobutane-1,2,3,4-tetracarboxylic dianhydride, 1,3-dimethylcyclobutane- An organic group of the following formula 10-2 derived from 1,2,3,4-tetracarboxylic dianhydride, tetrahydro-[3,3'-bifuran]-2,2',5,5'-tetraone The organic group of the following formula 10-3 derived from, the organic group of the following formula 10-4 derived from 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, the following formula 10-derived from pyromellitic acid dianhydride 5, or an organic group of Formula 10-6 derived from 3,3',4,4'-biphenyltetracarboxylic acid dianhydride.

[Formula 10-1]

[Formula 10-2]

[Formula 10-3]

[Formula 10-4]

[Formula 10-5]

[Formula 10-6]

Meanwhile, in the liquid crystal aligning agent composition according to the exemplary embodiment, the first polymer for liquid crystal aligning agent _{may be a divalent organic group in which Y 1} to Y ₃ in the repeating units of Formulas 1 to 3 are each independently represented by Formula 11 above. . Since the first polymer for liquid crystal aligning agent is synthesized from diamine containing an already imidized imide repeating unit, it is immediately irradiated with light without a high temperature heat treatment process after forming the coating film to generate anisotropy, and then heat treatment is performed to proceed with the alignment film Because it can be completed, not only can the light irradiation energy be greatly reduced, but also with a simple process including one heat treatment process, it is possible to manufacture a liquid crystal alignment film with excellent alignment and stability, as well as excellent voltage retention and electrical properties. can

Specifically, in Formula 11, T may be a functional group represented by the following Formula 10-1 or a functional group represented by the following Formula 10-2.

[Formula 10-1]

[Formula 10-2]

More specifically, examples of the organic group represented by Formula 11 are not particularly limited, but may be, for example, a functional group represented by Formula 11-1 or Formula 11-2.

[Formula 11-1]

[Formula 11-2]

In the first polymer for liquid crystal aligning agent, among the repeating units represented by Chemical Formula 1, Chemical Formula 2 and Chemical Formula 3, the repeating unit represented by Chemical Formula 1 is used in an amount of 5 mol% to 74 mol%, or 10 mol% to the total repeating unit. It may contain 60 mol%.

As described above, when the polymer including a specific content of the imide repeating unit represented by Formula 1 is used, the first liquid crystal aligning agent polymer contains a certain amount of the imidized imide repeating unit, and thus a high-temperature heat treatment The liquid crystal aligning film excellent in orientation and stability can be manufactured even if a process is omitted and light is irradiated immediately.

If the amount of the repeating unit represented by Chemical Formula 1 is less than the content range, sufficient orientation characteristics may not be exhibited, and orientation stability may be reduced, and if the content of the repeating unit represented by Chemical Formula 1 exceeds the above range, coating is stable A problem in that it is difficult to prepare an aligning solution may appear. Accordingly, it is preferable to include the repeating unit represented by Chemical Formula 1 in the above-described content range because it is possible to provide a polymer for liquid crystal aligning agent excellent in storage stability, electrical properties, orientation properties, and orientation stability.

In addition, the repeating unit represented by Formula 2 or the repeating unit represented by Formula 3 may be included in an appropriate amount according to desired properties.

Specifically, the repeating unit represented by Chemical Formula 2 may be included in an amount of 1 mol% to 60 mol%, preferably 5 mol% to 50 mol%, based on the total repeating unit represented by Chemical Formulas 1 to 3. Since the repeating unit represented by Formula 2 has a low conversion rate to imide during the high-temperature heat treatment process after light irradiation, when it exceeds the above range, the region interacting with the liquid crystal may be lowered, and thus alignment may be relatively reduced. Accordingly, the repeating unit represented by Chemical Formula 2 may provide a polymer for a liquid crystal aligning agent capable of implementing a high imidization rate while having excellent process characteristics within the above-described range.

In addition, the repeating unit represented by Chemical Formula 3 may be included in an amount of 0 mol% to 95 mol%, preferably 10 mol% to 80 mol%, based on the total repeating unit represented by Chemical Formulas 1 to 3. It is possible to provide a polymer for a liquid crystal aligning agent that exhibits excellent coating properties within this range and can implement a high imidization rate while having excellent process characteristics.

On the other hand, the first repeating unit included in the second liquid crystal aligning polymer in the liquid crystal aligning agent composition according to an embodiment is Y ₄ to Y ₆ in the repeating units of Chemical Formulas 4 to 6 are each independently represented by Chemical Formula 12 It may be a divalent organic group. The Y ₄ , Y ₅ , and Y ₆ may be defined as a divalent organic group represented by Chemical Formula 12 to provide a polymer for a liquid crystal aligning agent having various structures capable of expressing the above-described effects.

As such, as the first repeating unit included in the second polymer for liquid crystal aligning agent is synthesized from diamine containing a specific organic functional group represented by Chemical Formula 12, it can have a high voltage retention even in a high-temperature environment, and a low contrast ratio However, there is a feature of improving the electrical characteristics by improving the afterimage phenomenon.

In Formula 12, A is a group 15 element, and the group 15 element may be nitrogen (N), phosphorus (P), arsenic (As), tin (Sn), or bismuth (Bi). The R'^' is a functional group bonded to A, and may be bonded to the element A as many as the number of numbers represented by a. Preferably, in Formula 12, A may be nitrogen, R' may be hydrogen, and a may be 1.

On the other hand, in Formula 12, _{at least one of Z 1} to Z ₄ is nitrogen, and the rest is carbon, so that by the nitrogen atom, Formula 12 forms an asymmetric structure that is not symmetric with respect to a center point or a center line. can Formula 12 is an organic group derived from a diamine having a specific structure containing a nitrogen atom, which is a precursor used for forming a polymer for a liquid crystal aligning agent, and appears to be due to the use of an asymmetric diamine as described below.

The organic group represented by Chemical Formula 12 has a structural feature in which two aromatic ring compounds, preferably a heteroaromatic ring compound and an aromatic ring compound, are bonded via a secondary amine group or a tertiary amine group. Accordingly, the alignment and afterimage characteristics as a liquid crystal aligning agent satisfy the same level or higher, and the voltage retention rate is improved to realize excellent electrical characteristics.

On the other hand, when the two aromatic cyclic compounds are combined with a single bond without a secondary amine group or a tertiary amine group, there may be technical problems in that the alignment characteristics of the liquid crystal aligning agent are poor and the voltage holding ratio is significantly reduced.

In addition, when each of the two aromatic ring compounds bonded through a secondary amine group or a tertiary amine group does not contain a nitrogen atom, the imidation reaction is performed with respect to the polyamic acid or polyamic acid ester formed by the reaction of the amine with the acid anhydride. Even if it proceeds, there is a limit in that the imidization rate in the final liquid crystal alignment layer decreases as the imidization reaction does not proceed sufficiently (eg, through heat treatment at 230° C.).

In addition, the organic group represented by Formula 12 is characterized in that only an amine group and hydrogen are bonded to two aromatic ring compounds, preferably a heteroaromatic ring compound and an aromatic ring compound, respectively, and no other substituents are introduced. and, when a substituent, for example, a fluoroalkyl group is introduced into the heteroaromatic ring compound or the aromatic ring compound, the alignment characteristics of the liquid crystal aligning agent are poor, and technical problems in which the voltage retention rate is significantly reduced may occur.

More specifically, in Formula 12, one of Z ₁ to Z ₄ may be nitrogen and the rest may be carbon, or in Formula 12, one of Z ₁ or Z ₃ is nitrogen and the rest is carbon, and Z ₂ and Z ₄ may be carbon. That is, in Formula 12, _{the aromatic ring including Z 1} to Z ₄ may have a pyridine structure. Accordingly, the liquid crystal display device to which the polymer for liquid crystal aligning agent of the embodiment is applied can implement high voltage retention and liquid crystal alignment.

In addition, Formula 12 may include at least one functional group selected from the group consisting of Formula 12-1, Formula 12-2, and Formula 12-3.

[Formula 12-1]

[Formula 12-2]

[Formula 12-3]

In Formulas 12-1 to 12-3, _{the contents of A, Z 1} to Z ₄ , R ^' and a include the contents described above in Formula 12 above.

As such, since the organic group represented by Chemical Formula 12 includes one or more functional groups selected from the group consisting of Chemical Formulas 12-1, 12-2, and 12-3, superior liquid crystal alignment may be realized.

More specifically, examples of the organic group represented by Chemical Formula 12 are not particularly limited, but may be, for example, one or more functional groups selected from the group consisting of Chemical Formulas 12-4, 12-5, and 12-6 below. .

[Formula 12-4]

[Formula 12-5]

[Formula 12-6]

On the other hand, in the liquid crystal aligning agent composition according to the embodiment, the second repeating unit included in the second liquid crystal aligning agent polymer is 2 in Formulas 7 to 9, wherein Y ₇ to Y ₉ are each independently represented by Formula 13. It may be an organic group of By including the second repeating unit containing the organic group represented by the above formula (13) in the second liquid crystal aligning agent polymer, the alignment and afterimage characteristics as a liquid crystal aligning agent satisfy the equivalent level or more, and the voltage retention is highly improved, and DC It is possible to realize excellent electrical characteristics such as a low amount of residual DC due to a fast charging speed.

In addition, as the second repeating unit containing an organic group represented by Formula 13 is included in the polymer for a second liquid crystal aligning agent and has a chemical structural feature including an amide bond derived from a hydrazide group, The amide bond is maintained without being decomposed or deformed even by high-temperature heat treatment during the coating, drying, alignment, and firing processes of the composition containing the polymer for liquid crystal aligning agent, so that the above-described electrical property-related effects are stable even in the alignment film and alignment cell can be implemented as In addition, by forming hydrogen bonds between repeating units, excellent shielding power can be realized as the film density is improved.

In Formula 13, Q ₁ to Q ₈ are each independently carbon or nitrogen, L ₂ and L ₄ are each independently one of -CON(R ₁₅ )-, -N(R ₁₆ )CO-, and L ₃ is a single bond, -O-, -CO-, -S-, -SO ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -CONH-, -COO-, -(CH ₂ ) _b -, -O(CH ₂ ) _b O-, -O(CH ₂ ) _b -, -OCH ₂ -C(CH ₃ ) ₂ -CH ₂ O-, -COO-(CH ₂ ) _b -OCO -, or -OCO-(CH ₂ ) _b -COO-, R ₁₅ to R ₁₆ are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms, b is an integer of 1 to 10 each, n is 0 to 8 is the integer of

Specifically, examples of the organic group represented by the formula (13) are not particularly limited, but may be, for example, a functional group represented by the following formula (13-1).

[Formula 13-1]

In Formula 13-1, Q ₉ to Q ₁₂ may each independently be carbon or nitrogen, and R ₁₉ and R ₂₀ may each independently be hydrogen or an alkyl group having 1 to 10 carbon atoms.

More specifically, in Formula 13-1, Q ₉ to Q ₁₂ may all be carbon, and R ₁₉ and R ₂₀ may both be hydrogen.

Alternatively, in Formula 13-1, _{one of Q 9} to Q ₁₂ may be nitrogen, all others may be carbon, and both R ₁₉ and R ₂₀ may be hydrogen.

More specifically, Formula 13 may include a functional group represented by Formula 13-a or Formula 13-b.

[Formula 13-a]

[Formula 13-b]

On the other hand, in the field of polymers for liquid crystal aligning agents known in the prior art, the composition including the asymmetric diamine or a repeating unit derived therefrom together with the diamine of a specific structure containing a hydrazide group as described above and the effect thereof are not recognized at all In that it cannot do so, it can be said that the polymer including the repeating unit of Chemical Formulas 7 to 9 together with the repeating unit of Chemical Formulas 4 to 6 is novel. Accordingly, it is possible to provide a polymer for a liquid crystal aligning agent that exhibits excellent coating properties and can realize a high imidization rate while exhibiting excellent process characteristics, and also has excellent electrical properties such as residual images and voltage retention caused by DC/AC voltage. can

In particular, the second polymer for a liquid crystal aligning agent among the polymers for the liquid crystal aligning agent of the embodiment may include one or more repeating units selected from the group consisting of repeating units represented by the following Chemical Formulas 17 to 25.

[Formula 17]

[Formula 18]

[Formula 19]

[Formula 20]

[Formula 21]

[Formula 22]

[Formula 23]

[Formula 24]

[Formula 25]

In Formulas 17 to 25, _{the contents of R 3} to R ₆ , X ₄ to X ₉ , and Y ₄ to Y ₉ include those described above in Formulas 4 to 9 above. In addition, each of m ¹ to m ¹⁸ is the number of repetitions of the corresponding repeating unit, and each independently represents an integer between 1 and 500. At this time, each of m ¹ to m ¹⁸ may be adjusted according to the composition ratio of the two types of diamine compounds, that is, the mole % of the diamine having a specific structure containing an asymmetric diamine and a hydrazide group.

In this case, a first repeating unit comprising at least one selected from the group consisting of a repeating unit represented by Chemical Formula 4, a repeating unit represented by Chemical Formula 5, and a repeating unit represented by Chemical Formula 6, and represented by Chemical Formula 7 The molar ratio between the repeating unit, the repeating unit represented by Formula 8, and the second repeating unit comprising at least one selected from the group consisting of the repeating unit represented by Formula 9 is 1:99 to 99:1, 5: 95 to 95:5, or 10:90 to 90:10.

For example, when the molar ratio of the number of repeating units derived from the asymmetric diamine m ¹ , m ³ , m ⁵ , m ⁷ , m ⁹ , m ¹¹ , m ¹³ , m ¹⁵ , or m ^{17 is m odd} , m ^odd is from 1 mol% to 99 mol%, from 5 mol% to 99 mol%, or from 5 mol% to 95 mol%, or from 10 mol% to 95 mol%, alternatively from 10 mol% to 90 mol%, thus amide When the molar ratio of m ² , m ⁴ , m ⁶ , m ⁸ , m ¹⁰ , m ¹² , m ¹⁴ , m ¹⁶ , or m ¹⁸ derived from a diamine of a specific structure containing a group ^{is m even} , m ^even is 1-m ^odd , that is, from 99 mol% to 1 mol%, from 95 mol% to 1 mol%, or from 95 mol% to 5 mol%, or from 90 mol% to 5 mol%, or from 90 mol% to 10 mol% can be

More specifically, one selected from the group consisting of the repeating unit represented by Formula 4, the repeating unit represented by Formula 5, and the repeating unit represented by Formula 6, based on the number of moles of the second polymer repeating unit for liquid crystal aligning agent The molar content of the first repeating unit including more than one species may be calculated through the following [Equation 1].

[Equation 1]

Number of moles of the first repeating unit represented by Chemical Formulas 4 to 6 / Number of moles of the total repeating unit of the polymer for the second liquid crystal aligning agent * 100

Examples of the method for preparing the second polymer for the liquid crystal aligning agent are not particularly limited, and for example, a step of reacting a mixture comprising a diamine of the following Chemical Formula 26 and a diamine of the following Chemical Formula 27 with tetracarboxylic acid or an anhydride thereof; and imidizing the reaction product with the following tetracarboxylic acid or anhydride thereof may be used for preparing a polymer for a liquid crystal aligning agent.

[Formula 26]

In Formula 26, A is a group 15 element, R' is hydrogen or an alkyl having 1 to 10 carbon atoms, a is an integer of 1 to 3 _{, at least one of Z 1} to Z ₄ is nitrogen, and the remainder is carbon. can be

Also, preferably, in Formula 26, A is a nitrogen element, _one of Z 1 to Z ₄ is nitrogen and the rest is carbon, and Z ₂ and Z ₄ may be carbon.

[Formula 27]

In Formula 27, Q ₁ to Q ₈ are each independently carbon or nitrogen, L ₂ and L ₄ are each independently one of -CON(R ₁₅ )-, -N(R ₁₆ )CO-, and L ₃ is a single bond, -O-, -CO-, -S-, -SO ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -CONH-, -COO-, -(CH ₂ ) _b -, -O(CH ₂ ) _b O-, -O(CH ₂ ) _b -, -OCH ₂ -C(CH ₃ ) ₂ -CH ₂ O-, -COO-(CH ₂ ) _b -OCO -, or -OCO-(CH ₂ ) _b -COO-, R ₁₅ to R ₁₆ are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms, b is an integer of 1 to 10 each, n is 0 to 8 may be an integer of .

Here, the diamine of Formula 26 and the diamine of Formula 27 may be mixed in a molar ratio of 1:99 to 99:1, 5:95 to 95:5, or 10:90 to 90:10.

The mixture containing the diamines of Chemical Formulas 26 and 27 is a tetracarboxylic acid or anhydride thereof commonly used in the preparation of polyamic acids, for example, pyromellitic acid dianhydride, 3,3',4,4'-bi A polymer composed of amic acid, amic acid ester, or a mixture thereof may be prepared by reacting with phenyltetracarboxylic acid dianhydride or 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride.

Or, as needed, in addition to the diamines of Chemical Formulas 26 and 27, various types of diamine compounds widely known in the field related to liquid crystal aligning agents, for example, p-phenylenediamine, 4,4-oxydianiline, 4, 4'-methylenedianiline may be further mixed to prepare an amic acid, an amic acid ester, or a mixture thereof.

The reaction conditions may be appropriately adjusted with reference to the production conditions of polyamic acid known in the art to which the present invention pertains. And, the obtained amic acid, amic acid ester, or a mixture thereof is imidized to be selected from the group consisting of the repeating unit represented by the above formula 4, the repeating unit represented by the formula 5, and the repeating unit represented by the formula 6 A first repeating unit including one or more, and a second repeat including one or more selected from the group consisting of a repeating unit represented by Formula 7, a repeating unit represented by Formula 8, and a repeating unit represented by Formula 9 The polymer for liquid crystal aligning agents containing a unit simultaneously can be manufactured.

On the other hand, in the liquid crystal aligning agent composition according to an embodiment, the content of the second liquid crystal aligning agent may be 10 parts by weight to 1000 parts by weight, or 15 parts by weight to 800 parts by weight based on 100 parts by weight of the first polymer for the liquid crystal aligning agent. have.

When the polymer for the first liquid crystal aligning agent and the polymer for the second liquid crystal aligning agent having such characteristics are mixed and used in the above weight ratio range, the second liquid crystal has excellent photoreaction properties and liquid crystal alignment properties of the first liquid crystal aligning agent polymer. Because the excellent electrical properties of the polymer for alignment agent can be complemented with each other, it can exhibit excellent coating properties and realize high imidization rate while having excellent process characteristics, as well as problems such as afterimages caused by DC/AC voltage and voltage retention. It is possible to manufacture a liquid crystal aligning film having excellent electrical properties and a liquid crystal aligning film having better alignment and electrical properties at the same time.

The weight average molecular weight (GPC measurement) of each of the first polymer for liquid crystal aligning agent and the second polymer for liquid crystal aligning agent is not particularly limited, but may be, for example, 10000 g/mol to 200000 g/mol.

2. Manufacturing method of liquid crystal aligning film

According to another embodiment of the invention, forming a coating film by applying the liquid crystal aligning agent composition to a substrate (step 1); drying the coating film (step 2); Orienting the coating film by irradiating light or rubbing treatment (step 3); And it provides a method for producing a liquid crystal alignment film comprising the step of curing (step 4) by heat treating the alignment-treated coating film.

Step 1 is a step of forming a coating film by applying the above-described liquid crystal aligning agent composition to a substrate. The content regarding the liquid crystal aligning agent composition includes all of the content described above in the embodiment.

A method of applying the liquid crystal aligning agent composition to the substrate is not particularly limited, and for example, methods such as screen printing, offset printing, flexographic printing, and inkjet printing may be used.

In addition, the liquid crystal aligning agent composition may be dissolved or dispersed in an organic solvent. Specific examples of the organic solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone Don, N-vinylpyrrolidone, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy -N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, 1,3-dimethyl-imidazolidinone, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone , methyl isopropyl ketone, cyclohexanone, ethylene carbonate, propylene carbonate, diglyme, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl Ethers, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether, ethylene glycol monopropyl ether acetate, ethylene glycol monoisopropyl ether, ethylene glycol monoisopropyl ether acetate, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, etc. can be heard These may be used alone or may be used in combination.

In addition, the liquid crystal aligning agent composition may further include other components in addition to the organic solvent. As a non-limiting example, when the liquid crystal aligning agent composition is applied, the uniformity or surface smoothness of the film thickness is improved, or the adhesion between the liquid crystal aligning film and the substrate is improved, or the dielectric constant or conductivity of the liquid crystal aligning film is changed. Or, an additive capable of increasing the compactness of the liquid crystal alignment layer may be additionally included. Examples of such additives include various solvents, surfactants, silane-based compounds, dielectrics or crosslinking compounds.

Step 2 is a step of drying the coating film formed by applying the liquid crystal aligning agent composition to the substrate.

The drying of the coating film may use methods such as heating of the coating film, vacuum evaporation, etc., and is preferably performed at 50 °C to 150 °C, or 60 °C to 140 °C.

Step 3 is a step of alignment treatment by irradiating light to the coating film.

The coating film in the orientation treatment step may mean a coating film immediately after the drying step, or may be a coating film after heat treatment after the drying step. The "coating film immediately after the drying step" means directly irradiating light after the drying step without proceeding with the step of heat treatment at a temperature higher than the drying step, and steps other than heat treatment can be added.

More specifically, in the case of manufacturing a liquid crystal aligning film using a liquid crystal aligning agent containing polyamic acid or polyamic acid ester in the prior art, in order to imidize the polyamic acid, it is necessary to perform a high-temperature heat treatment and then irradiate light. However, in the case of manufacturing a liquid crystal aligning film using the liquid crystal aligning agent of the above-described embodiment, the alignment film is not included in the heat treatment step, and the alignment film is cured by heat treatment after alignment treatment by irradiating light immediately can be manufactured.

In addition, the light irradiation in the alignment treatment step may be to irradiate polarized ultraviolet rays with a wavelength of 150 nm to 450 nm. At this time, the intensity of exposure varies depending on the type of polymer for liquid crystal aligning agent, and energy of 10 mJ/cm 2 to 10 J/cm 2 , preferably 30 mJ/cm 2 to 2 J/cm 2 may be irradiated.

As the ultraviolet rays, a polarizing device using a substrate coated with a dielectric anisotropy material on the surface of a transparent substrate such as quartz glass, soda lime glass, soda lime free glass, a polarizing plate on which aluminum or metal wire is finely deposited, or quartz glass The alignment treatment is performed by irradiating polarized ultraviolet rays selected from among the polarized ultraviolet rays through a method of passing or reflecting a Brewster polarizing device by reflection. In this case, the polarized ultraviolet rays may be irradiated perpendicular to the substrate surface, or may be irradiated by inclining the incident angle to a specific angle. By this method, the alignment ability of the liquid crystal molecules is imparted to the coating film.

In addition, the rubbing treatment in the alignment treatment step may use a method using a rubbing cloth. More specifically, in the rubbing treatment, the surface of the coating film after the heat treatment step may be rubbed in one direction while rotating the rubbing roller with the cloth of the rubbing cloth attached to the metal roller.

Step 4 is a step of curing the alignment-treated coating film by heat treatment.

The step of curing the alignment-treated coating film by heat treatment is a step performed after light irradiation in the method of manufacturing a liquid crystal alignment film using a conventional polymer for liquid crystal aligning agent including polyamic acid or polyamic acid ester, and the liquid crystal aligning agent is It is distinguished from the heat treatment step performed to imidize the liquid crystal aligning agent before applying to the substrate and irradiating light or while irradiating light.

In this case, the heat treatment may be performed by a heating means such as a hot plate, a hot air circulation furnace, an infrared furnace, and is preferably performed at 150 °C to 300 °C, or 200 °C to 250 °C.

On the other hand, after the drying of the coating film (step 2), if necessary, may further include the step of heat-treating the coating film immediately after the drying step at a temperature higher than the drying step. The heat treatment may be carried out by a heating means such as a hot plate, a hot air circulation furnace, an infrared furnace, and is preferably performed at 150 °C to 250 °C. In this process, the liquid crystal aligning agent may be imidized.

That is, the manufacturing method of the liquid crystal aligning film includes the steps of forming a coating film by applying the liquid crystal aligning agent described above to a substrate (step 1); drying the coating film (step 2); heat-treating the coating film immediately after the drying step at a temperature higher than the drying step (step 3); It may include irradiating light to the heat-treated coating film or performing alignment treatment by rubbing treatment (step 4) and curing the alignment-treated coating film by heat treatment (step 5).

3. Liquid crystal alignment film

In addition, the present invention provides a liquid crystal aligning film prepared according to the manufacturing method of the above-described liquid crystal aligning film. Specifically, the liquid crystal aligning layer may include an alignment cured product of the liquid crystal aligning agent composition of the embodiment. The alignment cured product means a material obtained through an alignment process and a curing process of the liquid crystal aligning agent composition of the embodiment.

As described above, the first polymer for the liquid crystal aligning agent, and the second polymer for the liquid crystal aligning agent; using a liquid crystal aligning agent composition comprising, the stability is enhanced, it is possible to prepare a liquid crystal aligning film exhibiting excellent electrical properties .

The thickness of the liquid crystal alignment layer is not particularly limited, but can be freely adjusted within the range of, for example, 0.01 μm to 1000 μm. When the thickness of the liquid crystal alignment layer increases or decreases by a specific value, physical properties measured in the liquid crystal alignment layer may also change by a predetermined value.

Specifically, the liquid crystal alignment layer has a film strength of 0.10% or less, or 0.01% to 0.10%, 0.01% to 0.05%, or 0.01% to 0.04%, or 0.01% to 0.03%, or 0.02, calculated by the following Equation 2 % to 0.03%.

[Equation 2]

Film strength = haze of liquid crystal alignment film after rubbing treatment - haze of liquid crystal alignment film before rubbing treatment.

For the rubbing treatment of the liquid crystal alignment layer, a rubbing treatment method may be used while rotating the surface of the alignment layer at 1000 rpm using a rubbing machine manufactured by Sindo Engineering, and the haze value may be measured using a hazemeter.

^{In addition, the liquid crystal alignment layer has a film density of 1.25 g/cm 3} or more, or 1.25 g/cm ³ or more, measured by PANalytical X'Pert PRO MRD XRD under 45 kV, 40 mA Cu Kα radiation (wavelength: 1.54 Å) conditions. 1.50g / cm ^3, or 1.30 g / cm ³ to 1.40g / cm ^3, or 1.31 g / cm ³ to 1.40g / cm ^3, or 1.31 g / cm ³ to 1.35g / cm ^3, or 1.31 g / cm ^It may be 3 to 1.33 g/cm ^{3 .}

^{The liquid crystal alignment layer of the embodiment has a film density of 1.25 g/cm 3} or more measured by PANalytical X'Pert PRO MRD XRD under the conditions of 45 kV and 40 mA Cu Kα radiation (wavelength: 1.54 Å), which satisfies the above-mentioned range. When this is done, the film strength is increased and the shielding power by the eluted gas of the lower film is improved, so that the effect of maintaining the orientation reliability for a long time can be realized.

4. Liquid crystal display element

In addition, the present invention provides a liquid crystal display device including the above-described liquid crystal alignment layer.

The liquid crystal alignment layer may be introduced into a liquid crystal cell by a known method, and the liquid crystal cell may be introduced into a liquid crystal display device by a known method as well. The liquid crystal aligning layer is prepared from the liquid crystal aligning agent composition of the one embodiment to implement excellent stability with excellent overall physical properties. Specifically, it can have high voltage retention at high temperature and low frequency, so it has excellent electrical characteristics, reduces contrast ratio performance degradation or image sticking (afterimage), and has excellent film strength. can provide

Specifically, the liquid crystal display device has a voltage retention rate of 90% or more, or 93% to 99%, or 94% to 99%, or 94% measured using TOYO corporation's 6254C equipment at 1V, 1Hz, and 60 ℃ temperature. to 98%. When the voltage retention measured using TOYO Corporation's 6254C equipment at 1V, 1Hz, and 60 ℃ temperature of the liquid crystal alignment display device decreases to less than 90%, it is difficult to implement a liquid crystal display device with high quality driving characteristics at low power. can get

In addition, in the liquid crystal display, after attaching the polarizing plates to the upper and lower plates so as to be perpendicular to each other, attaching them on a backlight of 7,000 cd/m2, the initial luminance (L0), which is the luminance in the black state measured using the PR-880 equipment, and room temperature The luminance fluctuation rate, which is a value obtained by dividing the difference between the later luminance L1, which is the luminance in the black state, by the initial luminance L0 value, and multiplied by 100 after driving for 120 hours at an AC voltage of 7 V in the liquid crystal display, is 10 % may be less.

According to the present invention, a liquid crystal aligning agent composition having excellent liquid crystal alignment, durability and electrical properties when synthesizing a liquid crystal alignment film, and having excellent shielding power through high film density, a method for manufacturing a liquid crystal alignment film using the same, and a liquid crystal alignment film and liquid crystal using the same A display element is provided.

The invention is described in more detail in the following examples. However, the following examples only illustrate the present invention, and the content of the present invention is not limited by the following examples.

<Production Example>

Preparation Example 1: Preparation of diamine DA1-1

It was prepared according to the following reaction scheme.

Specifically, CBDA (cyclobutane-1,2,3,4-tetracarboxylic acid dianhydride, compound 1 ) and 4-nitroaniline were dissolved in DMF (dimethylformamide) to prepare a mixture. Then, the mixture was reacted at about 80° C. for about 12 hours to prepare the amic acid of compound 2. Then, the amic acid was dissolved in DMF, and acetic anhydride and sodium acetate were added to prepare a mixture. Then, the amic acid contained in the mixture was imidized at about 90 ℃ for about 4 hours to obtain compound 3. The imide of Compound 3 thus obtained was dissolved in DMAc (dimethylacetamide), and then Pd/C was added to prepare a mixture. Diamine DA1-1 was prepared by reducing this at about 45° C. and hydrogen pressure of about 6 bar for about 20 hours.

Preparation Example 2: Preparation of diamine DA1-2

The above except that DMCBDA (1,3-dimethylcyclobutane-1,2,3,4-tetracarboxylic acid dianhydride) was used instead of CBDA (cyclobutane-1,2,3,4-tetracarboxylic acid dianhydride). DA1-2 having the above structure was prepared in the same manner as in Preparation Example 1.

Preparation Example 3: Synthesis of diamine DA2-1

18.3 g (100 mmol) of 2-Chloro-5-nitropyridine (compound 4) and 12.5 g (98.6 mmol) of paraphenylenediamine (p-PDA, compound 5) were completely dissolved in about 200 mL of dimethylsulfoxide (DMSO). Then, 23.4 g (200 mmol) of triethylamine (Trimethylamine, TEA) was added and stirred at room temperature for about 12 hours. When the reaction was completed, the reactant was put into a container containing about 500 mL of water and stirred for about 1 hour. The solid obtained by filtration was washed with about 200 mL of water and about 200 mL of ethanol to synthesize 16 g (61.3 mmol) of compound 6 (yield: 60%).

After dissolving the compound 6 in about 200 mL of a 1:1 mixture of ethyl acetate (EA) and THF, 0.8 g of palladium (Pd)/carbon (C) was added, and under a hydrogen environment for about 12 hours. stirred for a while. After completion of the reaction, the filtrate filtered through a celite pad was concentrated to prepare 11 g of diamine DA2-1 (yield: 89%).

Preparation Example 4: Synthesis of diamine DA2-2

Diamine DA2-2 of Preparation Example 4 was prepared in the same manner as in Preparation Example 3 except that metaphenylenediamine (m-PDA, Compound 7) was used instead of the para-phenylenediamine (p-PDA, compound 5). prepared.

Preparation Example 5: Synthesis of diamine DA2-3

Except for using 2-chloro-4-nitropyridine (compound 8) instead of the 2-chloro-5-nitropyridine (2-chloro-5-nitropyridine, compound 4), Diamine DA2-3 of Preparation Example 5 was prepared in the same manner as in Preparation Example 3.

Preparation Example 6: Synthesis of diamine DA3-1

19.4 g (0.1 mol) of Dimethyl terephthalate (Compound 9) and 8.0125 g (0.25 mol) of Hydrazine monohydrate (Compound 10) were completely dissolved in about 10 mL of ethanol, followed by circulating stirring at 90° C. for 5 hours. When the reaction was completed, the solid obtained by filtering the reaction product was washed with about 200 mL of ethanol to synthesize 17.5 g of a diamine compound DA3-1 (Terephthalohydrazide, TPDH) (yield: 90.01%).

Preparation Example 7: Synthesis of diamine DA3-2

After completely dissolving 19.41 g (0.1 mol) of Dimethyl pyridine-2,5-dicarboxylate (Compound 11) and 8.0125 g (2.5 mol) of Hydrazine monohydrate (Compound 10) in about 10 mL of ethanol, circulate at 90 ° C for 5 hours. stirred. When the reaction was completed, the solid obtained by filtering the reaction product was washed with about 200 mL of ethanol to synthesize 16.24 g of a diamine compound DA3-2 (Pyridine-2,5-dicarbohydrazide) (yield: 83.23%).

<Synthesis example>

A first polymer, a second polymer, and a comparative polymer were synthesized using the reactants shown in Table 1 below. Specific synthesis conditions of each Synthesis Example and Comparative Synthesis Example are described in Table 1 below.

Synthesis example Primary diamine (mol%) secondary diamine (mol%) acid anhydride first polymer Synthesis Example 1 (P-1) Preparation Example 1 (100) DMCBDA Synthesis Example 2 (P-2) Preparation Example 2 (100) DMCBDA second polymer Synthesis Example 3 (Q-1) Preparation 3 (50) Preparation 6 (50) BPDA Synthesis Example 4 (Q-2) Preparation 3 (50) Preparation 7 (50) BPDA Comparative polymer Comparative Synthesis Example 1 (R-1) Preparation 6 (100) BPDA Comparative Synthesis Example 2 (R-2) Preparation 7 (100) BPDA

< Synthesis example 1 to 2: Synthesis of first polymer>

Synthesis Example 1: Preparation of polymer P-1 for liquid crystal aligning agent

5.0 g (13.3 mmol) of DA1-1 prepared in Preparation Example 1 was completely dissolved in 71.27 g of anhydrous N-methyl pyrrolidone (NMP). Then, 2.92 g (13.03 mmol) of 1,3-dimethyl-cyclobutane-1,2,3,4-tetracarboxylic dianhydride (DMCBDA) was added to the solution under an ice bath, and the liquid crystal was stirred at room temperature for about 16 hours. Polymer P-1 for an alignment agent was prepared.

As a result of confirming the molecular weight of the polymer P-1 through GPC, the number average molecular weight (Mn) was 15,500 g/mol, and the weight average molecular weight (Mw) was 31,000/mol. And the monomer structure of the polymer P-1 was determined by the equivalent ratio of the monomer used, and the ratio of the imide structure in a molecule|numerator was 50.5 %, and the ratio of the amic acid structure was 49.5 %.

Synthesis Example 2: Preparation of polymer P-2 for liquid crystal aligning agent

5.376 g of DA1-2 prepared in Preparation Example 2 was first dissolved in 74.66 g of NMP, and 2.92 g of 1,3-dimethyl-cyclobutane-1,2,3,4-tetracarboxylic acid dianhydride (DMCBDA) was added. The mixture was stirred at room temperature for about 16 hours. Thereafter, polymer P-2 was prepared in the same manner as in Synthesis Example 1.

As a result of confirming the molecular weight of the polymer P-2 through GPC, the number average molecular weight (Mn) was 17,300 g/mol, and the weight average molecular weight (Mw) was 34,000 g/mol. And the ratio of the imide structure in a molecule|numerator was 50.5 %, and the ratio of the amic-acid structure was 49.5 % of polymer P-2.

<Synthesis Examples 3 to 4: Second Polymer Synthesis>

Synthesis Example 3: Polymer Q-1 for liquid crystal aligning agents

After dissolving 38 mmol of the diamine DA2-1 prepared in Preparation Example 3 and 38 mmol of the diamine DA3-1 prepared in Preparation Example 6 in anhydrous N-methyl pyrrolidone (NMP), 3, 72.2 mmol of 3',4,4'-Biphenyltetracarboxylic acid dianhydride was added and stirred at 25° C. for 24 hours to prepare a polyamic acid polymer Q-1 for liquid crystal aligning agent.

Synthesis Example 4: Preparation of polymer Q-2 for liquid crystal aligning agent

Polymer Q-2 for a liquid crystal aligning agent was prepared in the same manner as in Synthesis Example 3, except that diamine DA3-2 obtained in Preparation Example 7 was used instead of the diamine DA3-1 prepared in Preparation Example 6.

<Comparative Synthesis Examples 1 to 2>

Comparative Synthesis Example 1: Preparation of polymer R-1 for liquid crystal aligning agent

The above Synthesis Example except that 38 mmol of the diamine DA2-1 prepared in Preparation Example 3 and 76 mmol of the diamine DA3-1 obtained in Preparation Example 6 were used instead of 38 mmol of the diamine DA3-1 prepared in Preparation Example 6 Polymer R-1 for liquid crystal aligning agents was manufactured by the method similar to 3.

Comparative Synthesis Example 2: Preparation of polymer R-2 for liquid crystal aligning agent

The above Synthesis Example except that 38 mmol of the diamine DA2-1 prepared in Preparation Example 3 and 76 mmol of the diamine DA3-2 obtained in Preparation Example 7 were used instead of 38 mmol of the diamine DA3-2 prepared in Preparation Example 7 Polymer R-2 for liquid crystal aligning agents was manufactured by the same method as 4.

<Examples and Comparative Examples: Preparation of liquid crystal aligning agent composition, liquid crystal alignment film, liquid crystal alignment cell>

Examples 1 to 4

(1) Preparation of liquid crystal aligning agent composition

A solution obtained by dissolving the first polymer and the second polymer in a mixed solvent of NMP, GBL, and 2-butoxyethanol to the composition shown in Table 2 below was stirred at 25° C. for 16 hours. A liquid crystal aligning agent composition was prepared by pressure filtration with a filter having a pore size of 0.1 μm made of poly (tetrafluorene ethylene) material.

(2) Preparation of liquid crystal alignment film

A liquid crystal aligning agent by spin coating on each of the upper and lower substrates for voltage maintenance ratio (VHR) in which an ITO electrode having a thickness of 60 nm and an area of 1 cm X 1 cm is patterned on a rectangular glass substrate having a size of 2.5 cm X 2.7 cm. The composition was applied. Then, the substrate coated with the liquid crystal aligning agent was placed on a hot plate at about 70° C. and dried for 3 minutes to evaporate the solvent.

In order to orient the obtained coating film, 254 nm ultraviolet rays were irradiated with an exposure amount of about 0.1 to 1 J/cm 2 using an exposure machine with a linear polarizer attached to each coating film of the upper and lower plates. Thereafter, the alignment-treated upper/lower plates were baked (cured) in an oven at about 230° C. for 30 minutes to obtain a liquid crystal alignment film having a thickness of 0.1 μm.

(3) Preparation of liquid crystal alignment cell

A sealing agent impregnated with a 4.5 μm ball spacer was applied to the edge of the upper plate except for the liquid crystal injection hole. And, after aligning the liquid crystal alignment layers formed on the upper and lower plates so that they face each other and the alignment directions are parallel to each other, the upper and lower plates are bonded and the sealing agent is UV and thermally cured to prepare an empty cell. Then, liquid crystal was injected into the empty cell and the injection hole was sealed with a sealing agent, thereby manufacturing a liquid crystal alignment cell.

Comparative Examples 1 to 2

Liquid crystal alignment in the same manner as in Example 1, except that a solution obtained by dissolving the first polymer and the second polymer in a mixed solvent of NMP, GBL, and 2-butoxyethanol to the composition shown in Table 2 below was used. A composition, a liquid crystal alignment film, and a liquid crystal alignment cell were prepared.

division first polymer second polymer Interpolymer weight ratio
(First Polymer: Second Polymer) Example 1 P-1 Q-1 5:5 Example 2 P-1 Q-2 5:5 Example 3 P-2 Q-1 5:5 Example 4 P-2 Q-2 5:5 Comparative Example 1 P-1 R-1 5:5 Comparative Example 2 P-1 R-2 5:5

< Experimental example >

1) Evaluation of liquid crystal alignment

Polarizing plates were attached to the upper and lower plates of the prepared liquid crystal alignment cell so as to be perpendicular to each other. Then, a liquid crystal alignment cell with a polarizer attached thereto was placed on a backlight having a brightness of 7,000 cd/m 2 and light leakage was observed with the naked eye. At this time, if the liquid crystal aligning film has excellent alignment characteristics and is well arranged, the light does not pass by the vertically attached upper and lower polarizing plates, and it is observed darkly without defects. In this case, the alignment characteristics were evaluated as 'good', and when light leakage such as liquid crystal flow marks or bright spots was observed, it was evaluated as 'poor', and the results are shown in Table 3 below.

2) Voltage holding ratio (VHR) measurement

Voltage holding ratio (VHR), which is an electrical characteristic of the prepared liquid crystal alignment cell, was measured using TOYO Corporation's 6254C equipment. Voltage retention (VHR) was measured at 1 Hz and 60 °C (VHR 60 ° 1 Hz p-LC conditions). The measurement results for the voltage retention (VHR) of the liquid crystal alignment cell are shown in Table 3 below.

3) Orientation stability evaluation (AC afterimage)

Polarizing plates were attached to the upper and lower plates of the prepared liquid crystal alignment cell so as to be perpendicular to each other. The liquid crystal cell to which the polarizing plate is attached was attached to a backlight of 7,000 cd/m 2 , and the luminance in the black state was measured using a luminance brightness measuring device, PR-788. Then, the liquid crystal cell was driven at room temperature with an AC voltage of 7 V for 12 hours. Then, in a state in which the voltage of the liquid crystal cell was turned off, the luminance of the black state was measured as described above. The difference between the initial luminance (L0) measured before driving of the liquid crystal cell and the later luminance (L1) measured after driving was divided by the initial luminance (L0) value and multiplied by 100 to calculate the luminance change rate. The calculated luminance fluctuation rate is closer to 0%, meaning better orientation stability. Through the measurement result of the luminance change rate, an afterimage level was evaluated under the following criteria. It is desirable to minimize the AC afterimage, and in the measurement result, if the luminance fluctuation rate is less than 10%, it is evaluated as 'excellent', if the luminance fluctuation rate is 10% to 20%, it is 'normal', and if the luminance fluctuation rate exceeds 20%, it is evaluated as 'poor'. , the results are shown in Table 3 below.

4) Membrane strength

For the prepared liquid crystal alignment film, the surface of the liquid crystal alignment film was rubbed while rotating at 1000 rpm using a rubbing machine manufactured by Sindo Engineering, and then the haze value was measured using a hazemeter, as shown in Equation 1 below. The film strength was evaluated by calculating the difference from the haze value before the rubbing treatment. The smaller the haze change value, the better the film strength.

[Equation 1]

Film strength = haze of liquid crystal alignment film after rubbing treatment - haze of liquid crystal alignment film before rubbing treatment.

5) Film density

With respect to the liquid crystal alignment layer, the sample was fixed in the sample holder using a magnet for measurement using PANalytical X'Pert PRO MRD XRD equipment under the conditions of 45 kV, current 40 mA Cu Kα radiation (wavelength: 1.54 Å). It was then mounted on the sample stage. For alignment, z->omega->z alignment was performed, and for XRR measurement, a step size of 0.002° and time per step of 1 second was measured in the range of 0.1°≤ 2θ≤1°. For precise measurement, the sample was rotated 90 degrees after measurement and measured once more.

division liquid crystal orientation orientation stability VHR (%) Film strength (%) film density
(g/cm ³ ) Example 1 Good Great 95 0.02 1.33 Example 2 Good Great 94 0.02 1.33 Example 3 Good Great 98 0.03 1.32 Example 4 Good Great 94 0.02 1.31 Comparative Example 1 Good Great 85 0.04 1.22 Comparative Example 2 Good Great 82 0.04 1.21

As shown in Table 3, in the case of Examples 1 to 4 using a polyimide-based polymer in which both polymers of the first polymer and the second polymer were mixed, 94% to 94% with excellent liquid crystal orientation and orientation stability It was confirmed that it exhibited a high voltage retention rate of 98% and exhibited excellent electrical characteristics. In addition, it was confirmed that, at the same time as the high film density of 1.31 g/cm ³ to 1.33 g/cm ^{3 ,} the haze change value before and after the rubbing treatment was very low, 0.02% to 0.03%, indicating excellent film strength.

On the other hand, instead of the copolymer synthesized by mixing the diamines of DA2-1 to DA2-3 prepared in Preparation Examples 3 to 5 with the diamines of DA3-1 to DA3-2 prepared in Preparation Examples 6 to 7, the above In the case of Comparative Examples 1 and 2 using polymers synthesized using only the diamines of DA3-1 to DA3-2 prepared in Preparation Examples 6 to 7, the voltage holding ratio was 85% or less, which was compared to the above examples. It was confirmed that the characteristics were inferior. In addition, the film density was also 1.22 g/cm ³ or less, and the haze change value before and after the rubbing treatment was 0.04% or more, confirming that it had inferior film density and film strength compared to the above example.

Claims (12)

A polymer for a first liquid crystal aligning agent comprising at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (1), a repeating unit represented by the following formula (2), and a repeating unit represented by the following formula (3); and
A first repeating unit comprising at least one selected from the group consisting of a repeating unit represented by the following formula (4), a repeating unit represented by the following formula (5), and a repeating unit represented by the following formula (6), and a repeating unit represented by the following formula (7) A second polymer for a liquid crystal aligning agent comprising a second repeating unit comprising at least one selected from the group consisting of a unit, a repeating unit represented by the following formula (8) and a repeating unit represented by the following formula (9);
The molar ratio between the first repeating unit and the second repeating unit included in the second polymer for liquid crystal aligning agent is 1:99 to 99:1, liquid crystal aligning agent composition:
[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

In Formulas 1 to 9,
At least one of R ₁ and R ₂ is an alkyl group having 1 to 10 carbon atoms, the rest is hydrogen,
At least one of R ₃ and R ₄ is an alkyl group having 1 to 10 carbon atoms, the rest is hydrogen,
At least one of R ₅ and R ₆ is an alkyl group having 1 to 10 carbon atoms, the rest is hydrogen,
X ₁ to X ₉ are each independently a tetravalent organic group represented by the following formula (10),
[Formula 10]

In the formula (10),
R ₇ to R ₁₂ are each independently hydrogen or an alkyl group having 1 to 6 carbon atoms,
L ₁ is a single bond, -O-, -CO-, -COO-, -S-, -SO-, -SO ₂ -, -CR ₁₃ R ₁₄ -, -(CH ₂ ) _Z -, -O(CH ₂ ) _Z O-, -COO(CH ₂ ) _Z OCO-, -CONH-, or any one selected from phenylene,
In L ₁ , R ₁₃ and R ₁₄ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or a haloalkyl group having 1 to 10 carbon atoms,
In L ₁ , z is an integer of 1 to 10,
wherein Y ₁ to Y ₃ are each independently a divalent organic group represented by the following Chemical Formula 11,
[Formula 11]

In the above formula (11),
T is a tetravalent organic group represented by Formula 10,
D ₁ and D ₂ are each independently an alkylene group having 1 to 20 carbon atoms, a heteroalkylene group having 1 to 10 carbon atoms, a cycloalkylene group having 3 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, or heteroaryl having 2 to 20 carbon atoms. It is one selected from among rengi,
The Y ₄ to Y ₆ are each independently a divalent organic group represented by the following formula (12),
[Formula 12]

In the above formula (12),
A is a group 15 element,
R' is hydrogen or alkyl having 1 to 10 carbon atoms,
a is an integer from 1 to 3,
At least one of Z ₁ to Z ₄ is nitrogen, the rest is carbon,
wherein Y ₇ to Y ₉ are each independently a divalent organic group represented by the following Chemical Formula 13,
[Formula 13]

In the above formula (13),
Q ₁ to Q ₈ are each independently carbon or nitrogen,
L ₂ and L ₄ are each independently one of -CON(R ₁₅ )-, -N(R ₁₆ )CO-,
L ₃ is a single bond, -O-, -CO-, -S-, -SO ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -CONH-, -COO-, - (CH ₂ ) _b -, -O(CH ₂ ) _z O-, -O(CH ₂ ) _b -, -OCH ₂ -C(CH ₃ ) ₂ -CH ₂ O-, -COO-(CH ₂ ) _b -OCO-, or -OCO-(CH ₂ ) _b -COO-,
R ₁₅ to R ₁₆ are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms,
b is an integer from 1 to 10 each,
n is an integer from 0 to 8;
According to claim 1,
In Chemical Formula 12, one of Z ₁ to Z ₄ is nitrogen, and the rest is carbon, the liquid crystal aligning agent composition.
According to claim 1,
In Chemical Formula 12, one of Z ₁ or Z ₃ is nitrogen and the rest is carbon, and Z ₂ and Z ₄ are carbon, the liquid crystal aligning agent composition.
According to claim 1,
In Formula 12, A is nitrogen, R' is hydrogen, and a is 1, the liquid crystal aligning agent composition.
According to claim 1,
Formula 12 is a liquid crystal aligning agent composition comprising at least one functional group selected from the group consisting of Formula 12-1, Formula 12-2, and Formula 12-3:
[Formula 12-1]

[Formula 12-2]

[Formula 12-3]

In Formulas 12-1 to 12-3,
A, Z ₁ to Z ₄ , R', a is as defined in claim 1.
According to claim 1,
In Formula 11, T is a functional group represented by the following formula 10-1 or a functional group represented by the following 10-2, liquid crystal aligning agent composition:
[Formula 10-1]

[Formula 10-2]

.
According to claim 1,
Chemical formula 13 is a liquid crystal aligning agent composition comprising a functional group represented by the following Chemical Formula 13-1:
[Formula 13-1]

In Formula 13-1,
Q ₉ to Q ₁₂ are each independently carbon or nitrogen,
R ₁₉ and R ₂₀ are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms.
According to claim 1,
Based on 100 parts by weight of the polymer for the first liquid crystal aligning agent, the second liquid crystal aligning agent polymer content is 10 parts by weight to 1000 parts by weight, the liquid crystal aligning agent composition.
delete Forming a coating film by applying the liquid crystal aligning agent composition of claim 1 to a substrate;
drying the coating film;
Orienting the coating film by irradiating light or rubbing treatment; and
A method of manufacturing a liquid crystal alignment film, including; curing the alignment-treated coating film by heat treatment.
The liquid crystal aligning film containing the orientation hardened|cured material of the liquid crystal aligning agent composition of Claim 1.
A liquid crystal display device comprising the liquid crystal alignment layer of claim 11 .