KR102601623B1 - Liquid crystal alignment film and liquid crystal display using the same - Google Patents

Abstract

The present invention relates to a liquid crystal alignment film including a polyimide-based polymer matrix and having a residual film ratio before and after exposure that satisfies a specific range, and a liquid crystal display device including the same.

Description

Liquid crystal alignment film and liquid crystal display device using the same {LIQUID CRYSTAL ALIGNMENT FILM AND LIQUID CRYSTAL DISPLAY USING THE SAME}

The present invention relates to a liquid crystal alignment film that can realize excellent liquid crystal alignment characteristics and at the same time, excellent electrical characteristics with high voltage retention and low residual DC voltage, and a liquid crystal display device using the same.

In a liquid crystal display device, the liquid crystal alignment film plays the role of aligning the liquid crystal in a certain direction. Specifically, the liquid crystal alignment film acts as a director in the arrangement of liquid crystal molecules and ensures proper orientation when the liquid crystal moves by an electric field to form an image. In order to obtain uniform brightness and high contrast ratio in a liquid crystal display device, it is essential to orient the liquid crystals uniformly.

As one of the conventional methods for aligning liquid crystals, a rubbing method was used in which a polymer film such as polyimide was applied to a substrate such as glass and the surface was rubbed in a certain direction using fibers such as nylon or polyester. However, the rubbing method can generate fine dust or electrostatic discharge (ESD) when the fiber and polymer film rub, which can cause serious problems when manufacturing liquid crystal panels.

In order to solve the problems of the rubbing method, a photo-alignment method that induces anisotropy in a polymer film by irradiation of light rather than friction and uses this to align liquid crystals has been studied.

A variety of materials that can be used in the photo-alignment method have been introduced, and among them, polyimide is mainly used for good overall performance of the liquid crystal alignment film. For this purpose, the polyimide is coated with a precursor such as polyamic acid or polyamic acid ester and then subjected to a heat treatment process at a temperature of 200°C to 230°C to form polyimide, which is then irradiated with light to perform orientation treatment.

However, in order to achieve sufficient liquid crystal orientation by irradiating the polyimide film with light, a lot of energy is required, which not only makes it difficult to secure actual productivity, but also requires an additional heat treatment process to ensure orientation stability after light irradiation, and the panel Due to the increase in size, chafing of the column space (CS) occurred during the manufacturing process, haze was generated on the surface of the liquid crystal alignment film, which caused defects in the Milky Way, which limited the panel's performance from being fully realized.

In particular, as the demand for low-power displays has increased recently, liquid crystal alignment agents can affect not only the basic characteristics of liquid crystal orientation, but also electrical characteristics such as afterimages generated by direct current/alternating voltage and voltage retention rate. was discovered, and the need for the development of liquid crystal alignment materials that can simultaneously realize excellent liquid crystal alignment and electrical properties is increasing.

The present invention is to provide a liquid crystal alignment film that can realize excellent liquid crystal alignment characteristics and at the same time, has a high voltage retention rate and low residual DC voltage, thereby realizing excellent electrical properties.

The present invention is also intended to provide a liquid crystal display device including the liquid crystal alignment film.

In this specification, a liquid crystal alignment film is provided that includes a polyimide-based polymer matrix and has a residual film rate of -20% or more and -5% or less according to Equation 1 below for a specimen with a pre-exposure thickness of 590 Å or more and 610 Å or less. .

[Equation 1]

Residual film rate = (A0 - A1) / A0 * 100

In Equation 1, A0 is the thickness (Å) of the specimen of the liquid crystal alignment film before exposure, and A1 is the thickness (Å) of the specimen of the liquid crystal alignment film after exposure.

Also provided in this specification is a liquid crystal display device including the liquid crystal alignment layer.

In this specification, also, DC stress, the residual DC voltage after applying +DC in the range of 0.5V to 1V for 1 minute at 60 ℃ and leaving the voltage unapplied for 2 minutes is 30 mV or less, 1Hz, 60 ℃ A liquid crystal display device having a voltage retention rate of 80% or more, measured using TOYO corporation's 6254C equipment, is provided.

Hereinafter, a liquid crystal alignment film and a liquid crystal display device including the same according to specific embodiments of the invention will be described in more detail.

In this specification, unless there is a special limitation, the following terms may be defined as follows.

In this specification, when a part “includes” a certain component, this means that it may further include other components rather than excluding other components unless specifically stated to the contrary.

In this specification, the term "substitution" means bonding with another functional group in place of a hydrogen atom in a compound, and the position to be substituted is not limited as long as it is the position where the hydrogen atom is substituted, that is, a position where the substituent can be substituted, and if two or more substitutions are made, , two or more substituents may be the same 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; imide group; amide group; amino group; carboxyl group; sulfonic acid group; sulfonamide group; Phosphine oxide group; Alkoxy group; Aryloxy group; Alkylthioxy group; Arylthioxy group; Alkyl sulphoxy group; Aryl sulfoxy group; silyl group; boron group; Alkyl group; Cycloalkyl group; alkenyl group; Aryl group; Aralkyl group; Aralkenyl group; Alkylaryl group; Arylphosphine group; or substituted or unsubstituted with one or more substituents selected from the group consisting of heterocyclic groups containing one or more of N, O and S atoms, or substituted or unsubstituted with two or more of the above-exemplified substituents linked. . For example, “a substituent group in which two or more substituents are connected” may be a biphenyl group. That is, the biphenyl group may be an aryl group, or it may be interpreted as a substituent in which two phenyl groups are connected.

In this specification, , or means a bond connected to another substituent, and a direct bond means a case where no separate atom exists in the part indicated by L.

In this specification, the alkyl group may be straight chain or branched, and the number of carbon atoms is not particularly limited, but is preferably 1 to 10. According to another embodiment, the carbon number of the alkyl group is 1 to 6. Specific examples of alkyl groups 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, etc., but is not limited to these.

In this specification, a halo alkyl group refers to a functional group in which a halogen group is substituted for the above-mentioned 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 is not particularly limited, but preferably has 6 to 20 carbon atoms, and may be a monocyclic aryl group or a polycyclic aryl group. The aryl group may be a monocyclic aryl group, such as a phenyl group, biphenyl group, or terphenyl group, but is not limited thereto. The polycyclic aryl group may be a naphthyl group, anthracenyl group, phenanthryl group, pyrenyl group, perylenyl group, chrysenyl group, fluorenyl group, etc., but is not limited thereto. The aryl group may be substituted or unsubstituted.

In the present specification, the arylene group is a divalent functional group derived from arene, and the description of the aryl group described above can be applied, except that it is a divalent functional group.

In the present specification, the multivalent functional group is a residue in which a plurality of hydrogen atoms bonded to any compound have been removed, and examples include a divalent functional group, a trivalent functional group, and a tetravalent functional group. For example, a tetravalent functional group derived from cyclobutane refers to a residue in which any four hydrogen atoms bonded to cyclobutane have been removed.

In this specification, a direct bond or single bond means that no atom or atomic group exists at the corresponding position and is connected by a bond line. Specifically, it refers to the case where no separate atom exists in the part represented by R _a or L _b (a and b are each integers of 1 to 20) in the chemical formula.

In this specification, the weight average molecular weight means the weight average molecular weight in terms of polystyrene measured by GPC method. In the process of measuring the weight average molecular weight of polystyrene equivalent measured by the GPC method, commonly known analysis devices, detectors such as differential refractive index detectors, and analytical columns can be used, and the commonly applied temperature Conditions, solvent, and flow rate can be applied. For a specific example of the above measurement conditions, a Waters PL-GPC220 instrument was used using a Polymer Laboratories PLgel MIX-B 300 mm long column, the evaluation temperature was 160°C, and 1,2,4-trichlorobenzene was used as a solvent. The flow rate is 1 mL/min, the sample is prepared at a concentration of 10 mg/10 mL, and then supplied in an amount of 200 μL. The value of Mw can be obtained using a calibration curve formed using a polystyrene standard. Nine types of molecular weights of polystyrene standards were used: 2,000 / 10,000 / 30,000 / 70,000 / 200,000 / 700,000 / 2,000,000 / 4,000,000 / 10,000,000.

1. Liquid crystal alignment film

According to one embodiment of the invention, a liquid crystal alignment film comprising a polyimide-based polymer matrix and having a residual film rate of -20% or more and -5% or less according to Equation 1 for a specimen with a pre-exposure thickness of 590 Å or more and 610 Å or less. This can be provided.

In the case of existing liquid crystal alignment films, the liquid crystal alignment properties are deteriorated, or when the liquid crystal alignment properties are excellent, the electrical properties are poor, making it difficult to implement excellent liquid crystal alignment properties and electrical properties at the same time.

Accordingly, the present inventors have found that by using a liquid crystal alignment film whose residual film ratio calculated by Equation 1 satisfies a specific range as described above, a liquid crystal display device that can implement not only liquid crystal alignment characteristics but also excellent electrical characteristics can be manufactured. was confirmed through experiment, and the invention was completed.

Generally, through the exposure step, the free volume of the liquid crystal alignment layer increases, thereby increasing the thickness of the liquid crystal alignment layer. At this time, if the residual film ratio calculated by Equation 1 above is less than a certain range, the free volume of the liquid crystal alignment layer increases excessively. , the liquid crystal alignment characteristics of the finally manufactured liquid crystal display device deteriorate. On the other hand, if the residual film ratio calculated by Equation 1 above exceeds a certain range, the free volume of the liquid crystal alignment layer may not increase sufficiently, and the electrical characteristics of the finally manufactured liquid crystal display device may be poor.

Therefore, when the residual film ratio according to Equation 1 of the liquid crystal alignment layer of the embodiment satisfies the above-mentioned range, not only are the physical properties of the liquid crystal alignment layer improved, but the physical properties of the final produced liquid crystal display device are also significantly improved. It can be implemented.

In Equation 1, A0 is the thickness (Å) of the liquid crystal alignment film specimen before exposure, and A1 is the thickness (Å) of the liquid crystal alignment film specimen after exposure.

The specimen of the liquid crystal alignment film may refer to a liquid crystal alignment film that undergoes processing and is subject to physical property measurement.

The thickness of the liquid crystal alignment layer is not greatly limited, but can be freely adjusted, for example, within the range of 590 Å to 1 ㎛.

In other words, the specimen of the liquid crystal alignment film may mean a liquid crystal alignment film having a thickness in the range of 590 Å to 1 ㎛ processed to a thickness of 590 Å or more and 610 Å or less for measuring physical properties. The processing method of the specimen can be broadly divided into Not limited.

In Equation 1, the thickness (A1) of the specimen of the liquid crystal alignment film after exposure is the thickness after exposing the specimen to ultraviolet rays with a wavelength of 150 nm to 450 nm using an ushio exposure machine at an exposure amount of 200 mJ/cm2 to 500 mJ/cm2. it means.

In Equation 1 above, thickness refers to the width between one surface that is subject to light irradiation or exhibits alignment characteristics by being irradiated with light and one surface of the liquid crystal alignment film that opposes it.

In Equation 1 above, exposure refers to an exposure step during the manufacturing process of a liquid crystal alignment film, and is specifically a step of alignment treatment by irradiating light.

Examples of methods for manufacturing a liquid crystal alignment film are not greatly limited, but include, for example, applying a liquid crystal alignment agent composition to a substrate to form a coating film (step 1); Drying the coating film (step 2); Orienting the coating film by irradiating light (step 3); and curing the alignment-treated coating film by heat treatment (step 4).

That is, in Equation 1, the liquid crystal alignment layer before exposure refers to the steps of forming a coating film by applying a liquid crystal alignment agent composition to a substrate in the method of manufacturing the liquid crystal alignment layer (step 1); It refers to a liquid crystal alignment layer after going through the step of drying the coating film (step 2), and the liquid crystal alignment layer after exposure refers to the liquid crystal alignment layer after going through the step of aligning the coating film by irradiating light (step 3).

In Equation 1, exposure may mean irradiating polarized ultraviolet rays with a wavelength of 150 nm to 450 nm, 310 nm to 390 nm, or 330 nm to 390 nm. At this time, the intensity of exposure varies depending on the type of polymer for the liquid crystal alignment agent, with an energy of 200 mJ/cm2 or more and 500 mJ/cm2 or less, or 250 mJ/cm2 or more and 450 mJ/cm2 or less, or 300 mJ/cm2 or more. Energy of 400 mJ/㎠ or less can be irradiated.

The ultraviolet rays include a polarizing device using a substrate coated with a dielectric anisotropic material on the surface of a transparent substrate such as quartz glass, soda-lime glass, and soda-lime-free glass, a polarizing plate with finely deposited aluminum or metal wire, or quartz glass. Orientation treatment is performed by irradiating polarized ultraviolet rays selected from among polarized ultraviolet rays by passing through or reflecting through a Brewster polarization device or the like. At this time, polarized ultraviolet rays may be irradiated perpendicularly to the substrate surface, or may be irradiated at an incident angle inclined at a specific angle. Through this method, the ability to align liquid crystal molecules is imparted to the coating film.

The method of measuring the thickness of the specimen of the liquid crystal alignment film in Equation 1 is not greatly limited, and can be used by thickness measurement methods generally used for synthetic resin films, sheets, screen masks, paper, fabrics, etc. . For example, the thickness of a liquid crystal alignment film specimen can be measured using a micrometer that inserts the object to be measured between two upper and lower disks and measures it by applying a pressure of 50 kpa (0.5 kg/cm2).

Specifically, in Equation 1, the thickness of the specimen of the liquid crystal alignment film can be measured under room temperature and pressure conditions using a thickness meter (KLA TENCOR, D600).

The room temperature condition refers to the normal temperature, which is not greatly limited, but ranges from 15°C to 35°C, 20°C to 35°C, or 20°C to 30°C, which is the average temperature throughout the year. In addition, the normal pressure condition is not limited to normal atmospheric pressure, but may mean a pressure of 1 atmosphere.

The residual film rate according to Equation 1 may be -20% or more and -5% or less, or -17% or more and -7% or less, -17% or more and -10% or less, or -16% or more and -12% or less.

As described above, by using a liquid crystal alignment film whose residual film ratio calculated by Equation 1 is -20% or more and -5% or less, a liquid crystal display device that can implement not only liquid crystal alignment characteristics but also excellent electrical characteristics can be provided.

Specifically, when the residual film ratio calculated by Equation 1 above is less than -20%, the free volume of the liquid crystal alignment layer increases excessively, and the uniaxial alignment of the alignment layer significantly decreases, ultimately weakening the azimuthal anchoring E of the alignment layer. Technical problems may occur in which the liquid crystal alignment characteristics of the manufactured liquid crystal display device deteriorate.

On the other hand, when the residual film ratio calculated by Equation 1 above exceeds -5, the free volume of the liquid crystal alignment layer is not sufficiently increased, and the resistance characteristics of the liquid crystal alignment layer are not improved. Therefore, the finally manufactured liquid crystal display device Technical problems may occur where the electrical characteristics of the device deteriorate.

Accordingly, when the residual film ratio of the liquid crystal alignment layer of the above embodiment according to Equation 1 is -20% or more and -5% or less, a liquid crystal alignment layer that implements excellent liquid crystal alignment characteristics and also has excellent electrical properties can be provided.

In Equation 1, A0 is the thickness (Å) of the specimen of the liquid crystal alignment film before exposure, and may be 590 Å or more and 610 Å or less, 594 Å or more and 605 Å or less, and 594 Å or more and 603 Å or less.

The specimen of the liquid crystal alignment film before exposure may be a specimen in which the liquid crystal alignment film is processed to measure physical properties. That is, in Equation 1, A0 refers to the thickness (Å) of a sample of the liquid crystal alignment film before exposure. Specifically, it may be the thickness of a sample manufactured by forming a film on a glass substrate based on 600 Å. If the thickness of the liquid crystal alignment film specimen increases or decreases by a certain amount, the physical properties measured from the liquid crystal alignment film may also change by a certain amount.

In Equation 1, A1 is the thickness (Å) of the specimen of the liquid crystal alignment film after exposure, and is 500 Å or more and 800 Å or less, 550 Å or more and 750 Å or less, or 600 Å or more and 720 Å or less, or 630 Å or more and 720 Å or less, or It may be 650 Å or more and 720 Å or less.

The specimen of the liquid crystal alignment layer after exposure may be an exposed specimen prepared for measuring physical properties. That is, in Equation 1, A1 is the thickness (Å) of the specimen of the liquid crystal alignment film after exposure. Specifically, for specimens with a thickness of 590 Å or more and 610 Å or less, polarized ultraviolet rays with a wavelength of 150 ㎚ to 450 ㎚ are applied at 200 mJ/ It may be the thickness of a specimen of the liquid crystal alignment film after irradiation with an energy of ㎠ or more and 500 mJ/㎠ or less.

In Equation 1, when A1 exceeds 800 Å, the free volume of the liquid crystal alignment layer excessively increases, the uniaxial alignment of the alignment layer is significantly lowered, and the azimutal anchoring E of the alignment layer becomes weak, resulting in the final manufactured liquid crystal display. Technical problems may occur where the liquid crystal alignment characteristics of the device deteriorate.

On the other hand, in Equation 1, when A1 is less than 500 Å, the free volume of the liquid crystal alignment layer is not sufficiently increased, and the resistance characteristics of the liquid crystal alignment layer are not improved, and thus the electrical properties of the finally manufactured liquid crystal display device deteriorate. Technical problems may occur.

In A0 of Equation 1, the liquid crystal alignment layer before exposure may further include an epoxy additive dispersed in the polyimide-based polymer matrix. The polyimide-based polymer matrix includes polyimide-based polymer or a cured product of polyimide-based polymer. The polyimide-based polymer refers to polyimide or its precursor, and may specifically include polyimide, polyamic acid, polyamic acid ester, or mixtures or copolymers thereof.

That is, the liquid crystal alignment layer before exposure may contain the polyimide-based polymer matrix and the epoxy additive in a dispersed state without being bonded to each other.

The epoxy additive is a compound containing an epoxy group in the molecule, and may include, for example, a compound containing 1 or more, 2 or more, or 4 or more epoxy groups in the molecule.

The epoxy additive may be a glycidyl-based hetero compound.

The glycidyl-based hetero compound may be a glycidyl amine-based compound, a glycidyl ether-based compound, or a glycidyl ester-based compound, and specifically contains one or more, two or more, or four or more glycidyl groups in the molecule. It may contain one compound.

As a specific example, the epoxy additives include MY0500, MY0510, MY720, MY721, MY0600, MY9512, MY9663, TGDDM, TGMDA, DGEBA, YD-128, ELM434, YH434L, Jer604, Jer630, TETRAD-X, TETRAD-C, ELM100, ELM120. , YDF-2001, YDF-2004, YDPN638, YDPN638P, YDCN-701, YDCN-702, YDCN-703, YDCN-704, DEN431, DEN438, DEN439, PY307, EPN1179, EPN1180, ECN9511, ECN1273, ECN1280, ECN1285, ECN1299 , HP7200L, HP7200, HP7200H, HP7200HH, HP7200HHH, etc. can be used.

The epoxy additive may be dispersed in an amount of 1% to 10% by weight, 3% to 10% by weight, or 5% to 10% by weight relative to the polyimide polymer matrix.

If the epoxy additive is dispersed in an amount exceeding 10% by weight relative to the polyimide-based polymer matrix, the alignment of the liquid crystal alignment film chains may decrease due to overpolymerization with the epoxy additive, thereby deteriorating the liquid crystal alignment characteristics of the liquid crystal alignment film.

Additionally, if the epoxy additive is dispersed in an amount of less than 1% by weight relative to the polyimide-based polymer matrix, the electrical properties of the liquid crystal alignment layer may deteriorate.

Therefore, as described above, the liquid crystal alignment layer according to the embodiment includes a polyimide-based polymer matrix and an epoxy additive dispersed in the liquid crystal alignment layer before exposure without being combined with each other, and the epoxy additive is lower than that of the polyimide-based polymer matrix. As it is contained in an amount of 1% by weight or more and 10% by weight or less, it is possible to exhibit excellent liquid crystal alignment characteristics and at the same time, realize excellent electrical properties.

In A1 of Equation 1, the liquid crystal alignment layer after exposure may further include an epoxy additive bonded to the polyimide-based polymer matrix. The polyimide-based polymer matrix includes polyimide-based polymer or a cured product of polyimide-based polymer. The polyimide-based polymer refers to polyimide or its precursor, and may specifically include polyimide, polyamic acid, polyamic acid ester, or mixtures or copolymers thereof.

That is, as the liquid crystal alignment film before exposure contains a polyimide-based polymer matrix and an epoxy additive dispersed therein, during the exposure process, the polyimide-based polymer matrix and an epoxy additive dispersed therein react to form a combined form of liquid crystal after exposure. It may be included in the alignment film.

In A1 of Equation 1, as the liquid crystal alignment layer after exposure includes an epoxy additive bonded to the polyimide-based polymer matrix, the free volume of the liquid crystal alignment layer after exposure may increase compared to the liquid crystal alignment layer before exposure. .

The free volume refers to a space that can be formed around the ends or middle of a polymer chain so that the polymer chain can move freely with respect to other polymer chains surrounding it.

As the polyimide-based polymer matrix undergoes an exposure process and a curing process, it is rearranged to obtain a polymer matrix with fine pores, and thus has an increased free volume compared to the liquid crystal alignment layer before exposure.

In the liquid crystal alignment film of one embodiment of the invention, the polyimide-based polymer matrix may include one or more repeating units selected from the group consisting of polyimide repeating units, polyamic acid ester repeating units, and polyamic acid repeating units. As described above, as the polyimide-based polymer matrix includes a polymer of polyimide, polyamic acid, or polyamic acid ester or a cured product thereof, the polyimide-based polymer matrix includes a polyimide repeating unit and a polyamic acid ester repeating unit. , and it may include one or more types of repeating units selected from the group consisting of polyamic acid repeating units.

Specifically, the polyimide-based polymer matrix may include one or more repeating units selected from the group consisting of Formulas 4 to 6 below.

[Formula 4]

[Formula 5]

[Formula 6]

In the above formulas 4 to 6, at least one of R ⁹ and R ¹⁰ is an alkyl group having 1 to 10 carbon atoms, the remainder is hydrogen, and X ³ to X ⁵ are each independently a tetravalent organic group represented by the following formula 3,

[Formula 3]

In Formula 3, R ¹ to R ⁶ are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms, and L ¹ is a direct bond, -O-, -CO-, -COO-, -S-, -SO-, -SO ₂ -, -CR ⁷ R ⁸ -, -(CH ₂ ) _Z -, -O(CH ₂ ) _Z O-, -COO(CH ₂ ) _Z OCO-, -CONH-, phenylene or a combination thereof is any one selected from the group consisting of, wherein R ⁷ and R ⁸ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or a fluoroalkyl group, and Z is an integer of 1 to 10,

Y ³ to Y ⁵ are each independently a divalent organic group represented by the following formula (7),

[Formula 7]

In Formula 7, A is a tetravalent organic group represented by Formula 3, and D ¹ and D ² are each independently an arylene group having 6 to 20 carbon atoms.

The formulas 4 to 6 may be repeating units derived through polymerization of a diamine compound of a specific structure containing tetracarboxylic acid or its anhydride and an imide group.

The X ³ to X ⁵ may be a functional group derived from polyamic acid, polyamic acid ester, or tetracarboxylic dianhydride compound used in polyimide synthesis.

Preferably, ^the above X ³ to , an organic group of the following formula 3-2 derived from 2,3,4-tetracarboxylic dianhydride, from tetrahydro-[3,3'-bifuran]-2,2',5,5'-tetraone An organic group of the following formula 3-3 derived from 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, an organic group of the following formula 3-4 derived from pyromellitic acid dianhydride, and an organic group of the following formula 3-5 derived from pyromellitic acid dianhydride. It may be an organic group of, or an organic group of the following formula 3-6 derived from 3,3',4,4'-biphenyltetracarboxylic acid dianhydride.

[Formula 3-1]

[Formula 3-2]

[Formula 3-3]

[Formula 3-4]

[Formula 3-5]

[Formula 3-6]

The above formula (7) corresponds to a portion of repeating units derived from a diamine of a specific structure containing an imide group, which is a precursor used to form a polymer for a liquid crystal aligning agent.

More specifically, in Formula 7, D ¹ and D ² may each independently be the following Formula 7-1 or Formula 7-2.

[Formula 7-1]

[Formula 7-2]

In Formula 7-2, L ₅ is a single bond, -O-, -SO ₂ -, or -CR ₂₀ R ₂₁ -, where R ₂₀ and R ₂₁ are each independently hydrogen or a group of 1 to 10 carbon atoms. It is alkyl.

Preferably, Formula 7-1 may be Formula 7-a below.

[Formula 7-a]

Additionally, the above Chemical Formula 7-2 may be the following Chemical Formula 7-b.

[Formula 7-b]

In Formula 7-b, L ₅ is O or CH ₂ .

More specifically, examples of the organic group represented by Formula 7 are not greatly limited, but may be, for example, a functional group represented by Formula 7-c or Formula 7-d below.

[Formula 7-c]

[Formula 7-d]

Also, specifically, in Formula 7, A may be a functional group represented by Formula 3-1 or a functional group represented by Formula 3-2.

In addition, the polyimide-based polymer matrix includes a repeating unit represented by Formula 4, which is an imide repeating unit, among the repeating units represented by Formula 4, Formula 5, and Formula 6. It may contain 5 to 74 mol%, preferably 10 to 60 mol%, based on the repeating unit.

As described above, when a polymer containing a certain amount of imide repeating units represented by Formula 4 is used, since it contains a certain amount of already imidized imide repeating units, the high-temperature heat treatment process is omitted and the polymer is directly exposed to light. Even with irradiation, a liquid crystal alignment film with excellent liquid crystal orientation and stability can be manufactured.

If the repeating unit represented by Formula 4 is included in less than the above 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 Formula 4 exceeds the above range, the coating is stable. Problems may arise that make it difficult to manufacture the alignment solution. Accordingly, it is preferable to include the repeating unit represented by Formula 4 in the above-described content range because it can provide a liquid crystal alignment film with excellent electrical properties and alignment properties.

Additionally, the repeating unit represented by Formula 5 or the repeating unit represented by Formula 6 may be included in an appropriate amount depending on the desired characteristics.

Specifically, the repeating unit represented by Formula 5 may be included in an amount of 0 to 40 mol%, preferably 0 to 30 mol%, based on the total repeating units represented by Formulas 4 to 6. Since the repeating unit represented by Formula 5 has a low conversion rate to imide during a high-temperature heat treatment process after light irradiation, if it exceeds the above range, the overall imidization rate may be insufficient and orientation stability may be reduced.

In addition, the repeating unit represented by Formula 6 may be included in an amount of 0 to 95 mol%, preferably 10 to 90 mol%, based on the total repeating units represented by Formulas 4 to 6.

In addition, the polyimide-based polymer matrix includes a repeating unit including at least one member selected from the group consisting of Formulas 10 to 12 below; It may further include.

[Formula 10]

[Formula 11]

[Formula 12]

In Formulas 10 to 12, at least one of R ¹³ and R ¹⁴ is an alkyl group having 1 to 10 carbon atoms, the remainder is hydrogen, and X ⁸ to X ¹⁰ are each independently a tetravalent organic group represented by Formula 3, Y ⁸ to Y ¹⁰ are each independently a divalent organic group represented by the following formula (13),

[Formula 13]

In Formula 13, R ¹⁵ and R ¹⁶ are each independently selected from hydrogen, halogen, cyano, nitrile, alkyl with 1 to 10 carbon atoms, alkenyl with 1 to 10 carbon atoms, alkoxy with 1 to 10 carbon atoms, and 1 to 10 carbon atoms. is fluoroalkyl, or fluoroalkoxy having 1 to 10 carbon atoms, p and q are each independently an integer of 0 to 4, and L ² is a direct bond, -O-, -CO-, -S-, -SO ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -CONH-, -COO-, -(CH ₂ ) _y -, -O(CH ₂ ) _y O-, -O( CH ₂ ) _y -, -NH-, -NH(CH ₂ ) _y -NH-, -NH(CH ₂ ) _y O-, -OCH ₂ -C(CH ₃ ) ₂ -CH ₂ O-, -COO- (CH ₂ ) _y -OCO-, or -OCO-(CH ₂ ) _y -COO-, y is an integer from 1 to 10, k and m are each independently an integer from 0 to 3, and n is 0 to 3. It is an integer of 3.

The above formulas 10 to 12 may be repeating units derived through the polymerization reaction of tetracarboxylic acid or its anhydride and a diamine compound.

More specifically, Formula 13 may each independently be Formula 13-1 or Formula 13-2 below.

[Formula 13-1]

[Formula 13-2]

In Formula 13-2, L ₆ is a single bond, -O-, -SO ₂ -, or -CR ₂₆ R ₂₇ -, where R ₂₆ and R ₂₇ are each independently hydrogen or a group of 1 to 10 carbon atoms. It is alkyl.

Preferably, Formula 13-1 may be Formula 13-a below.

[Formula 13-a]

Additionally, Formula 13-2 may be Formula 13-b below.

[Formula 13-b]

In Formula 13-b, L ₆ is O or CH ₂ .

More preferably, Formula 13 is represented by Formula 13-b, and in Formula 13-b, L ₆ may be -O-.

Meanwhile, in A1 of Equation 1, the liquid crystal alignment layer after exposure may include a complex in which the carbonyl functional group of the polyimide-based polymer matrix and the ethylene group of the epoxy additive are bonded through an ether bond. That is, during the exposure process, the polyimide-based polymer matrix and the epoxy additive dispersed therein may react to form a complex in which the carbonyl functional group of the polyimide-based polymer matrix and the ethylene group of the epoxy additive are bonded through an ether bond.

As described above, the polyimide-based polymer matrix may include a polyimide-based polymer such as polyimide, polyamic acid, or polyamic acid ester, and a cured product thereof.

Specifically, the liquid crystal alignment film before exposure may contain a polyamic acid or polyamic acid ester containing a carboxyl group or an ester group in the repeating unit, and the epoxy additive dispersed therein is very reactive, and is combined with the carboxyl group or ester group of the polyamic acid or polyamic acid ester. can react

Accordingly, in A1 of Equation 1, the liquid crystal alignment layer after exposure may include a complex obtained by reacting the carboxyl group or ester group of the polyimide-based polymer matrix with the epoxy group of the epoxy additive. Through the above reaction, the carbonyl functional group of the polyimide-based polymer matrix and the ethylene group of the epoxy additive can be bonded, and the bond between the carbonyl functional group of the polyimide-based polymer matrix and the ethylene group of the epoxy additive can be mediated by an ether bond.

According to one embodiment of the invention, the complex may include one or more repeating units selected from the group consisting of Formula 1 and Formula 2 below.

[Formula 1]

[Formula 2]

In Formulas 1 and 2, X ¹ to X ² are each independently a tetravalent organic group, Y ¹ to Y ² are each independently a divalent organic group, and R' and R" are each independently hydrogen or It is a tetravalent organic group.

The above formulas 1 and 2 may be repeating units derived through the polymerization reaction of a polyimide-based repeating unit and an epoxy additive.

In Formulas 1 and 2, the monovalent to tetravalent organic group may be one of an organic group containing one or more epoxy groups, an organic group containing one or more hydroxy groups, or an organic group containing one or more epoxy groups and one or more hydroxy groups, respectively. .

R' and R" are organic groups derived from epoxy additives. Specifically, when the organic group of the monovalent to tetravalent organic group is an organic group containing one or more epoxy groups, the added epoxy additive contains two or more epoxy groups. As a compound, only one epoxy group among two or more epoxy groups contained in an epoxy additive may be a functional group formed by combining with the polyimide-based polymer matrix.

Alternatively, when the monovalent to tetravalent organic group is an organic group containing one or more hydroxy groups, the added epoxy additive is a compound containing two or more epoxy groups, and two or more epoxy groups among the two or more epoxy groups contained in the epoxy additive are polyi. It may be a functional group formed by combining with a mid-based polymer matrix.

Alternatively, when the monovalent to tetravalent organic groups are organic groups containing one or more epoxy groups and one or more hydroxy groups, the added epoxy additive is a compound containing three or more epoxy groups, and two or more epoxy groups among the three or more epoxy groups contained in the epoxy additive It may be a functional group formed by bonding to the polyimide-based polymer matrix and one or more epoxy groups not bonding with the polyimide-based polymer matrix.

More specifically, the epoxy additive may be a glycidyl-based hetero compound. That is, R' and R" may be organic groups derived from a glycidyl-based hetero compound.

The composite is formed in the group consisting of Formula 1 and Formula 2, as the polyimide-based polymer matrix includes one or more repeating units selected from the group consisting of polyimide repeating units, polyamic acid ester repeating units, and polyamic acid repeating units. It may contain one or more selected repeating units.

The complex may further include one or more repeating units selected from the group consisting of Formulas 4 to 6. That is, the epoxy additive dispersed in the polyimide-based polymer matrix combines with some of the repeating units included in the polyimide-based polymer matrix through exposure, forming one or more repeating units selected from the group consisting of Formula 1 and Formula 2. The repeating unit included in the polyimide-based polymer matrix to which no epoxy additive is bound may include one or more repeating units selected from the group consisting of Formulas 4 to 6.

In this way, in Equation 1, as the liquid crystal alignment layer after exposure includes a complex containing one or more repeating units selected from the group consisting of Formula 1 and Formula 2, the free volume will increase compared to the liquid crystal alignment layer before exposure. Accordingly, Equation 1 satisfies the above-mentioned range, so that a liquid crystal alignment film having excellent liquid crystal alignment properties and electrical properties can be provided.

In Formulas 1 and 2, X ¹ to X ² may be a tetravalent organic group represented by Formula 3.

In addition, the complex may further include a functional group represented by Formula 8 or Formula 9 at least at one end.

[Formula 8]

In Formula 8, X ⁶ is a tetravalent organic group represented by Formula 3, Y ⁶ is a divalent organic group represented by Formula 7, and R' and R" are each independently hydrogen or a monovalent organic group. ego,

[Formula 9]

In ^{Formula 9} , and R ¹¹ and R ¹² are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms.

In Formulas 8 and 9, the monovalent organic group may be one of an organic group containing one or more epoxy groups, an organic group containing one or more hydroxy groups, or an organic group containing one or more epoxy groups and one or more hydroxy groups.

R' and R" are organic groups derived from epoxy additives. Specifically, when the monovalent organic group is an organic group containing one or more epoxy groups, the added epoxy additive is a compound containing two or more epoxy groups, and is added to the epoxy additive. Among the two or more epoxy groups contained, only one epoxy group may be a functional group formed by combining with the polyimide-based polymer matrix.

Alternatively, when the monovalent organic group is an organic group containing one or more hydroxy groups, the added epoxy additive is a compound containing two or more epoxy groups, and two or more epoxy groups among the two or more epoxy groups contained in the epoxy additive are used in the polyimide polymer. It may be a functional group formed by combining with a matrix.

Alternatively, when the monovalent organic group is an organic group containing one or more epoxy groups and one or more hydroxy groups, the added epoxy additive is a compound containing three or more epoxy groups, and two or more epoxy groups among the three or more epoxy groups contained in the epoxy additive are It may be a functional group that is bonded to a mid-based polymer matrix and formed when one or more epoxy groups are not bonded to the polyimide-based polymer matrix.

Meanwhile, the complex may further include a repeating unit including one or more selected from the group consisting of Formula 14 and Formula 15 below.

[Formula 14]

[Formula 15]

In Formulas ¹⁴ and ¹⁵ , X ^{11 and} ' and R" are each independently hydrogen or a monovalent organic group,

[Formula 13]

In Formula 13, R ¹⁵ and R ¹⁶ are each independently selected from hydrogen, halogen, cyano, nitrile, alkyl with 1 to 10 carbon atoms, alkenyl with 1 to 10 carbon atoms, alkoxy with 1 to 10 carbon atoms, and 1 to 10 carbon atoms. is fluoroalkyl, or fluoroalkoxy having 1 to 10 carbon atoms, p and q are each independently an integer of 0 to 4, and L ² is a direct bond, -O-, -CO-, -S-, -SO ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -CONH-, -COO-, -(CH ₂ ) _y -, -O(CH ₂ ) _y O-, -O( CH ₂ ) _y -, -NH-, -NH(CH ₂ ) _y -NH-, -NH(CH ₂ ) _y O-, -OCH ₂ -C(CH ₃ ) ₂ -CH ₂ O-, -COO- (CH ₂ ) _y -OCO-, or -OCO-(CH ₂ ) _y -COO-, y is an integer from 1 to 10, k and m are each independently an integer from 0 to 3, and n is 0 to 3. It is an integer of 3.

Formulas 14 and 15 may be repeating units derived through the polymerization reaction of a polyimide-based repeating unit and an epoxy additive.

In Formulas 14 and 15, the monovalent organic group may be one of an organic group containing one or more epoxy groups, an organic group containing one or more hydroxy groups, or an organic group containing one or more epoxy groups and one or more hydroxy groups.

R' and R" are organic groups derived from epoxy additives. Specifically, when the monovalent organic group is an organic group containing one or more epoxy groups, the added epoxy additive is a compound containing two or more epoxy groups, and is added to the epoxy additive. Among the two or more epoxy groups contained, only one epoxy group may be a functional group formed by combining with the polyimide-based polymer matrix.

Alternatively, when the monovalent organic group is an organic group containing one or more hydroxy groups, the added epoxy additive is a compound containing two or more epoxy groups, and two or more epoxy groups among the two or more epoxy groups contained in the epoxy additive are used in the polyimide polymer. It may be a functional group formed by combining with a matrix.

Alternatively, when the monovalent organic group is an organic group containing one or more epoxy groups and one or more hydroxy groups, the added epoxy additive is a compound containing three or more epoxy groups, and two or more epoxy groups among the three or more epoxy groups contained in the epoxy additive are It may be a functional group that is bonded to a mid-based polymer matrix and formed when one or more epoxy groups are not bonded to the polyimide-based polymer matrix.

Meanwhile, the complex containing one or more repeating units selected from the group consisting of Formulas 14 and 15 is mixed with the complex containing one or more repeating units selected from the group consisting of Formulas 1 and 2, forming a liquid crystal. By being used in an alignment layer, the electrical properties of the alignment layer, such as voltage holding ratio, can be greatly improved.

The liquid crystal alignment film according to the above embodiment includes at least one repeating unit selected from the group consisting of Formula 1 and Formula 2 and at least one repeating unit selected from the group consisting of Formula 14 and Formula 15 in an overall polyimide-based polymer matrix. It may include 1wt% or more and 15wt% or less, 3wt% or more and 10wt% or less, and 4wt% or more and 7wt% or less.

A composite comprising at least one repeating unit selected from the group consisting of Formulas 1 and 2 and at least one repeating unit selected from the group consisting of Formulas 14 and 15 in an amount exceeding 15 wt% based on the total polyimide polymer matrix. When included, the liquid crystal alignment characteristics of the liquid crystal alignment film may deteriorate.

In addition, at least one repeating unit selected from the group consisting of Formula 1 and Formula 2 and at least one repeating unit selected from the group consisting of Formula 13 and Formula 14 are contained in an amount of less than 1 wt% based on the entire polyimide polymer matrix. When a composite is included, the electrical properties of the liquid crystal alignment layer may be deteriorated.

Therefore, as described above, the liquid crystal alignment film according to the embodiment has a repeating unit in which the carbonyl functional group of the polyimide polymer matrix and the ethylene group of the epoxy additive are bonded through an ether bond in an amount of 1 wt% or more and 15 wt% or less based on the total repeating units. By including it, it is possible to exhibit excellent liquid crystal alignment characteristics and at the same time realize excellent electrical properties.

In addition, the weight average molecular weight (GPC measurement) of the polyimide-based polymer matrix may be 5000 g/mol to 100000 g/mol, 5000 g/mol to 80000 g/mol, or 5000 g/mol to 50000 g/mol. .

Meanwhile, examples of the method for manufacturing the liquid crystal alignment layer are not greatly limited, but include, for example, applying a liquid crystal alignment agent composition to a substrate to form a coating film (step 1); Drying the coating film (step 2); Orienting the coating film by irradiating light or rubbing it (step 3); and curing the alignment-treated coating film by heat treatment (step 4).

Step 1 is a step of forming a coating film by applying the above-described liquid crystal alignment agent composition to a substrate.

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

Additionally, 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, and N-ethylpyrroli. Don, N-vinylpyrrolidone, dimethyl sulfoxide, tetramethyl urea, pyridine, dimethyl sulfone, hexamethyl sulfoxide, 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. Ether, ethylene glycol monoethyl ether acetate, ethylene glycol mono profile ether, ethylene glycol monoopyl ether acetate, ethylene glycol monoisopyl ether Back can be mentioned. These may be used individually or in combination.

Additionally, 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 alignment agent composition is applied, it improves the uniformity of film thickness or surface smoothness, improves the adhesion between the liquid crystal alignment layer and the substrate, or changes the dielectric constant or conductivity of the liquid crystal alignment layer. Alternatively, additives that can increase the density of the liquid crystal alignment layer may be additionally included. Examples of such additives may 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 alignment agent composition to the substrate.

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

Step 3 is a step of aligning the coating film by irradiating light.

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 “coat film immediately after the drying step” refers to light irradiation immediately after the drying step without proceeding with heat treatment at a temperature higher than the drying step, and other steps other than heat treatment can be added.

More specifically, in the case of manufacturing a liquid crystal alignment film using a liquid crystal alignment agent containing polyamic acid or polyamic acid ester, the step of performing high temperature heat treatment and then irradiating light to imidize the polyamic acid is essential. However, when manufacturing the liquid crystal alignment film of the above-described embodiment, the heat treatment step is not included, and the alignment film can be manufactured by directly irradiating light for alignment treatment, and then heat-treating and curing the alignment-treated coating film.

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

The step of curing the alignment-treated coating film by heat treatment is different from the heat treatment step of applying the liquid crystal alignment agent to the substrate and imidizing the liquid crystal alignment agent before or while irradiating light.

At this time, the heat treatment may be performed by a heating means such as a hot plate, hot air circulation furnace, or infrared furnace, and is preferably performed at 150 ℃ to 300 ℃, or 200 ℃ to 250 ℃.

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

That is, the method of manufacturing the liquid crystal alignment film includes forming a coating film by applying the above-described liquid crystal alignment agent 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 the step of aligning the heat-treated coating film by irradiating light or rubbing it (step 4) and curing the aligned coating film by heat treatment (step 5).

2. Liquid crystal display device

According to another embodiment of the invention, a liquid crystal display device including the above-described liquid crystal alignment layer is provided.

The liquid crystal alignment film can be introduced into a liquid crystal cell by a known method, and the liquid crystal cell can likewise be introduced into a liquid crystal display device by a known method. The example of the manufacturing method of the liquid crystal display device including the liquid crystal alignment film is not greatly limited, and various existing liquid crystal display device manufacturing processes can be applied, preferably a sealing agent impregnated with a ball spacer of 3 ㎛ size. ) is applied to the edge of the upper plate excluding the liquid crystal inlet, and the liquid crystal alignment films of the present invention formed on the upper and lower plates are aligned so that they face each other and their orientation directions are parallel to each other, and then the upper and lower plates are bonded and the sealing agent is cured to create an empty cell. A horizontal alignment mode liquid crystal display device can be manufactured by manufacturing and injecting liquid crystal into the empty cell.

On the other hand, the liquid crystal display device has a residual DC voltage of 30 mV or less after applying DC stress, +DC in the range of 0.5V to 1V for 1 minute at 60°C and leaving the voltage unapplied for 2 minutes, 1Hz, The voltage retention rate measured using TOYO corporation's 6254C equipment at 60°C may be more than 80%.

Specifically, DC stress at 60°C, after applying +DC in the range of 0.5V to 1V for 1 minute and leaving the voltage unapplied for 2 minutes, the residual DC voltage is 30 mV or less, 1 mV or more and 30 mV or less, Alternatively, it may be 1 mV or more and 25 mV or less, or 10 mV or more and 23 mV or less. In addition, the voltage retention rate measured using TOYO corporation's 6254C equipment at 1Hz and 60°C may be 80% or more, 80% or more and 99% or less, or 85% or more and 99% or less, or 85% or more and 95% or less.

If the voltage retention rate of the liquid crystal display device measured at 1V, 1Hz, and 60°C temperature using TOYO Corporation's 6254C equipment decreases to less than 80%, it will become difficult to implement a liquid crystal display device with high-quality driving characteristics at low power. You can.

In addition, if the residual DC voltage after applying DC stress, +DC in the range of 0.5V to 1V for 1 minute at 60 ℃ of the liquid crystal and leaving the voltage unapplied for 2 minutes, is more than 30 mV, the DC charging speed Because the temperature is slow, the content of DC remaining in the alignment film may be excessive, resulting in deterioration of electrical properties.

The residual DC voltage after applying DC stress, +DC in the range of 0.5V to 1V for 1 minute at 60 ℃ and leaving the voltage unapplied for 2 minutes is 30 mV or less, and at 1Hz, 60 ℃, TOYO corporation's A liquid crystal display device having a voltage retention ratio of 80% or more measured using a 6254C device may include a liquid crystal alignment layer according to the above-described embodiment.

The present invention can provide a liquid crystal alignment film and a liquid crystal display device using the same, which can implement excellent liquid crystal alignment characteristics and at the same time have high voltage retention and low residual DC voltage, thereby realizing excellent electrical characteristics.

The invention is explained 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.

<Manufacturing example and comparative manufacturing example>

Preparation Example 1: Preparation of diamine DA1-1

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

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 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 added to about 200 mL. After completely dissolving in dimethylsulfoxide (DMSO), 23.4 g (200 mmol) of triethylamine (TEA) was added and stirred at room temperature for about 12 hours. When the reaction was completed, the reactant was placed in a container containing about 500 mL of water and stirred for about 1 hour. The solid obtained by filtering this 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%).

Compound 6 was dissolved in about 200 mL of a 1:1 mixture of ethyl acetate (EA) and THF, then 0.8 g of palladium (Pd)/carbon (C) was added and incubated in a hydrogen environment for about 12 hours. It was stirred for a while. After completion of the reaction, the filtrate was concentrated through a Celite pad 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 Preparation Example 3, except that metaphenylenediamine (m-PDA, Compound 7) was used instead of paraphenylenediamine (p-PDA, Compound 5). Manufactured.

Preparation Example 5: Synthesis of diamine DA2-3

The above except that 2-chloro-4-nitropyridine (compound 8) was used instead of 2-chloro-5-nitropyridine (compound 4). Diamine DA2-3 of Preparation Example 5 was prepared in the same manner as Preparation Example 3.

Preparation Example 6: Synthesis of diamine DA3-1

17.1 g (100 mmol) of 2-chloro-5-nitropyridine (Compound 4 ) and 12.5 g (98.6 mmol) of 4-nitrophenol (Compound 5 ) were mixed with 200 mL of dimethyl After completely dissolving in sulfoxide (Dimethylsulfoxide, DMSO), 27.2 g (200 mmol) of potassium carbonate (K ₂ CO ₃ ) was added and stirred at room temperature for about 16 hours. When the reaction was completed, the reactant was placed in a container containing about 500 mL of water and stirred for about 1 hour. The solid obtained by filtering this was washed with about 200 mL of water and about 200 mL of ethanol to synthesize 16 g (61.3 mmol) of a diamine compound (yield: 57%).

The above compound was dissolved in about 200 mL of a 1:1 mixture of ethyl acetate (EA) and THF, then 0.8 g of palladium (Pd)/carbon (C) was added and incubated in a hydrogen environment for about 12 hours. It was stirred. After completion of the reaction, the filtrate was concentrated on a Celite pad to prepare 11 g of diamine compound DA3-1 (yield: 89%).

Preparation Example 7: Synthesis of diamine DA3-2

Diamine compound DA2-2 was prepared in the same manner as in Preparation Example 6, except that 3-nitrophenol was used instead of 4-nitrophenol (Compound 5 ).

Preparation Example 8: Synthesis of diamine DA3-3

The above preparation example, except that 2-chloro-4-nitropyridine (2-chloro-4-nitropyridine) was used instead of 2-chloro-5-nitropyridine (Compound 4 ). Diamine compound DA3-3 was prepared in the same manner as in 6.

<Synthesis example>

The first polymer and the second polymer were synthesized using the reactants listed in Table 1 below. Specific synthesis conditions for each Synthesis Examples 1 to 8 are listed in Table 1 below.

Synthesis example diamine acid anhydride first polymer Synthesis Example 1 (P-1) Production Example 1 (DA1-1) DMCBDA Synthesis Example 2 (P-2) Production Example 2 (DA1-2) DMCBDA second polymer Synthesis Example 3 (Q-1) Production Example 3 (DA2-1) BT-100 Synthesis Example 4 (Q-2) Production Example 3 (DA2-1) CHDA Synthesis Example 5 (Q-3) Production Example 3 (DA2-1) PMDA Synthesis Example 6 (Q-4) Production Example 6 (DA3-1) PMDA Synthesis Example 7 (Q-5) Production Example 6 (DA3-1) BPDA Synthesis Example 8 (Q-6) Production Example 6 (DA3-1) HPMDA

< Synthesis example 1 to 2: First polymer synthesis>

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 acid dianhydride (DMCBDA) was added to the solution under an ice bath and stirred at room temperature for about 16 hours to form liquid crystals. Polymer P-1 for orientation 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. In addition, the monomer structure of polymer P-1 was determined by the equivalence ratio of the monomers used, and the ratio of the imide structure in the molecule 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 then 2.92 g of 1,3-dimethyl-cyclobutane-1,2,3,4-tetracarboxylic acid dianhydride (DMCBDA) was added. It was stirred at room temperature for about 16 hours. Afterwards, 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. In addition, polymer P-2 had an imide structure ratio of 50.5% and an amic acid structure ratio of 49.5% within the molecule.

<Synthesis Examples 3 to 8: Second polymer synthesis>

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

21.735 g (0.109 mmol) of diamine DA2-1 prepared in Preparation Example 3 was completely dissolved in 236.501 g of anhydrous N-methyl pyrrolidone (NMP).

And, under the ice bath, tetrahydro-[3,3'-bifuran]-2,2',5,5'-tetraone (tetrahydro-[3,3'-bifuran]-2,2',5,5 20.0 g (0.101 mmol) of '-tetraone, BT100) was added to the solution and stirred at room temperature for about 16 hours to prepare polymer Q-1 for a liquid crystal alignment agent. As a result of confirming the molecular weight of polymer Q-1 through GPC, the weight average molecular weight (Mw) was 26,400 g/mol.

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

Diamine DA2-1 prepared in Preparation Example 3 above 19.211 g (0.096 mmol) was completely dissolved in 222.194 g of anhydrous N-methyl pyrrolidone (NMP).

Then, 20.0 g (0.089 mmol) of 1,2,4,5-Cyclohexanetetracarboxylic Dianhydride (CHDA) was added to the solution under an ice bath and incubated at room temperature for about 16 hours. By stirring for a while, polymer Q-2 for a liquid crystal aligning agent was prepared. As a result of confirming the molecular weight of polymer Q-2 through GPC, the weight average molecular weight (Mw) was 24,000 g/mol.

Synthesis Example 5: Preparation of polymer Q-3 for liquid crystal aligning agent

19.743 g (0.099 mmol) of diamine DA2-1 prepared in Preparation Example 3 was completely dissolved in 225.213 g of anhydrous N-methyl pyrrolidone (NMP).

Then, 20.0 g (0.092 mmol) of pyromellitic dianhydride (PMDA) was added to the solution under an ice bath and stirred at room temperature for about 16 hours to prepare polymer Q-3 for a liquid crystal alignment agent. As a result of confirming the molecular weight of polymer Q-3 through GPC, the weight average molecular weight (Mw) was 27,000 g/mol.

Synthesis Example 6: Polymer Q-4 for liquid crystal aligning agent

19.840 g (0.099 mmol) of diamine DA3-1 prepared in Preparation Example 6 was completely dissolved in 225.761 g of anhydrous N-methyl pyrrolidone (NMP).

Then, 20.0 g (0.092 mmol) of pyromellitic dianhydride (PMDA) was added to the solution under an ice bath and stirred at room temperature for about 16 hours to prepare polymer Q-4 for a liquid crystal aligning agent. As a result of confirming the molecular weight of the polymer Q-4 through GPC, the weight average molecular weight (Mw) was 27,000 g/mol.

Synthesis Example 7: Polymer Q-5 for liquid crystal aligning agent

14.708 g (0.073 mmol) of diamine DA3-1 prepared in Preparation Example 6 was completely dissolved in 196.681 g of anhydrous N-methyl pyrrolidone (NMP).

Then, 20.0 g (0.068 mmol) of 3,3',4,4'-Biphenyl Tetracarboxylic Acid Dianhydride (BPDA) was added to the solution under an ice bath. Then, the mixture was stirred at room temperature for about 16 hours to prepare polymer Q-5 for a liquid crystal aligning agent. As a result of confirming the molecular weight of polymer Q-5 through GPC, the weight average molecular weight (Mw) was 23,000 g/mol.

Synthesis Example 8: Polymer Q-6 for liquid crystal aligning agent

19.305 g (0.096 mmol) of diamine DA3-1 prepared in Preparation Example 6 was completely dissolved in 222.726 g of anhydrous N-methyl pyrrolidone (NMP).

Then, 20.0 g (0.089 mmol) of 1,2,4,5-Cyclohexanetetracarboxylic Dianhydride (HPMDA) was added to the solution under an ice bath and incubated at room temperature for about 16 hours. By stirring for a while, polymer Q-6 for a liquid crystal aligning agent was prepared. As a result of confirming the molecular weight of polymer Q-6 through GPC, the weight average molecular weight (Mw) was 26,500 g/mol.

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

Examples 1 to 3

(1) Preparation of liquid crystal aligning agent composition

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

Next, a liquid crystal alignment agent composition was prepared by pressure filtration using a filter made of poly(tetrafluorene ethylene) with a pore size of 0.2 ㎛.

(2) Preparation of liquid crystal alignment film

A comb-shaped IPS (in-plane switching) mode type ITO electrode pattern is formed on a square glass substrate measuring 2.5 cm The liquid crystal aligning agent composition prepared in Example 1 was applied to a (lower plate) and a glass substrate (upper plate) without an electrode pattern, respectively, using spin coating.

Next, the substrate coated with the liquid crystal alignment agent composition was placed on a hot plate at about 80° C. and dried for 1 minute to evaporate the solvent. In order to orientate the coating film obtained in this way, the coating film of each of the upper and lower plates was irradiated with ultraviolet rays of approximately 254 nm at an exposure dose of approximately 400 mJ/cm2 using an exposure machine equipped with a linear polarizer.

Next, the coating film was subjected to low-temperature heat treatment by placing it on a hot plate at 130°C for 500 seconds. Afterwards, the coating film was baked (cured) in an oven at about 230° C. for 20 minutes to prepare a liquid crystal alignment film.

(3) Manufacturing of liquid crystal alignment cells

A sealing agent impregnated with a 3 ㎛ ball spacer was applied to the edge of the top plate excluding the liquid crystal inlet. Then, the alignment films of the examples and comparative examples formed on the upper and lower plates were aligned so that they faced each other and their orientation directions were parallel to each other, and then the upper and lower plates were bonded and the sealant was cured to manufacture an empty cell. Then, liquid crystal was injected into the empty cell to manufacture a liquid crystal cell in horizontal alignment mode.

Comparative Example 1

With the composition shown in Table 2 below, a liquid crystal alignment agent composition, a liquid crystal alignment film, and a liquid crystal alignment cell were prepared in the same manner as in the above example, except that the glycidyl amine-based epoxy additive compound was not added.

Comparative Example 2

With the composition shown in Table 2 below, a liquid crystal alignment agent composition, a liquid crystal alignment film, and A liquid crystal alignment cell was manufactured.

Comparative Example 3

With the composition shown in Table 2 below, a liquid crystal alignment agent composition, a liquid crystal alignment film, and A liquid crystal alignment cell was manufactured.

Comparative Example 4

With the composition shown in Table 2 below, the liquid crystal alignment agent composition, liquid crystal alignment film, and liquid crystal were prepared in the same manner as in the above example, except that XD-1000 (Nippon Kayaku) was added instead of the glycidyl amine-based epoxy additive. An orientation cell was manufactured.

first polymer second polymer Weight ratio of first polymer:second polymer Additive content (%) Example 1 P-1 Q-1 1:1 5 Example 2 P-1 Q-1 1:1 8 Example 3 P-1 Q-1 1:1 10 Comparative Example 1 P-1 Q-1 1:1 0 Comparative Example 2 P-1 Q-1 1:1 5 Comparative Example 3 P-1 Q-1 1:1 5 Comparative Example 4 P-1 Q-1 1:1 5

< Experiment example >

1) Residual film rate

In the above examples and comparative examples, specimens were manufactured by forming a liquid crystal alignment film on a glass substrate with a thickness of 600 Å after drying was completed and before exposure was performed.

The specimen was irradiated with ultraviolet rays of 254 nm at an exposure dose of 300 mJ/cm2 to 500 mJ/cm2 using an exposure machine equipped with a linear polarizer, and the thickness (A1) of the specimen of the liquid crystal alignment film after exposure was measured using a thickness meter (KLA TENCOR). Using (D600, Co., Ltd.), measurements were made at 25°C and 1 atm, and the residual film rate was calculated using Equation 1 below.

[Equation 1]

Residual film rate = (A0 - A1) / A0 * 100

In Equation 1 above,

A0 is the thickness (Å) of the specimen of the liquid crystal alignment film before exposure,

A1 is the thickness (Å) of a specimen of the liquid crystal alignment film after irradiating ultraviolet rays of about 254 nm at an exposure dose of 300 mJ/cm2 to 500 mJ/cm2 using an exposure machine equipped with a linear polarizer.

2) Evaluation of liquid crystal orientation characteristics

Polarizing plates were attached to the upper and lower plates of the liquid crystal alignment cells manufactured in the examples and comparative examples so as to be perpendicular to each other. The liquid crystal cell with the polarizer attached was attached on a backlight of 7,000 cd/m2, and the luminance in the black state was measured using PR-788, a luminance brightness measurement equipment. Then, the liquid crystal cell was driven at room temperature with an alternating voltage of 7 V for 120 hours. Afterwards, with the voltage of the liquid crystal cell turned off, the luminance in the black state was measured in the same manner as described above. The difference between the initial luminance (L0) measured before driving 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 fluctuation rate. The closer the luminance variation rate calculated in this way is to 0%, the better the orientation stability.

3) RDC (residual DC voltage, residual DC)

For the liquid crystal alignment cells manufactured in the above examples and comparative examples, DC stress, +DC in the range of 0.5 to 1 V, was applied at 60°C for 1 minute, then left without applying voltage for 2 minutes, and then the remaining The amount of DC was measured as residual DC. The measurement results for the residual DC voltage (RDC) of the liquid crystal alignment cell are shown in Table 3 below.

4) Voltage holding ratio (VHR)

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

residual film rate Liquid crystal orientation characteristics (%) RDC(mV) Voltage retention rate (%) A0(Å) A1(Å) Remaining film rate (%) Example 1 602 683 -13.4 0.1 19 86 Example 2 594 688 -15.8 0.2 21 88 Example 3 601 675 -12.3 0.2 18 92 Comparative Example 1 599 589 1.66 0.1 34 66 Comparative Example 2 600 602 -0.33 0.4 110 70 Comparative Example 3 603 591 1.99 0.3 56 76 Comparative Example 4 596 589 1.2 0.5 100 72

As shown in Table 3, the liquid crystal alignment film of the example containing a polyimide polymer and an epoxy additive of a specific structure in the composition showed a residual film rate of -15.8% to -12.3%, and a luminance fluctuation rate of 0.2% or less. It was confirmed that it exhibited excellent liquid crystal orientation characteristics. In addition, it was confirmed that the voltage retention ratio was very high, ranging from 86% to 92%, and the RDC was 21 mV or less, showing excellent electrical characteristics. As a result, it was confirmed that the liquid crystal alignment film prepared from the liquid crystal alignment agent composition of the above example had excellent alignment properties and at the same time realized excellent electrical properties as the residual film ratio satisfied the range of -20% to -5%.

On the other hand, the alignment film obtained from the liquid crystal alignment agent composition of Comparative Example 1, which does not contain an epoxy additive of a specific structure, had a residual film rate of 1.66% and did not satisfy the range of 20% to -5%, resulting in a voltage retention rate of 66%. and RDC was measured to be 34 mV, confirming that the electrical characteristics were significantly inferior to those of the above example.

On the other hand, the alignment films obtained from the liquid crystal alignment agent compositions of Comparative Examples 2 to 4 using an epoxy additive having a structure different from the examples of the present application showed a residual film rate of -0.33% to 1.99%, satisfying the range of -20% to -5%. As this was not possible, the voltage retention was measured to be between 70% and 72% and the RDC was measured to be over 56 mV, confirming that the electrical characteristics were significantly inferior to those of the above example. In addition, the alignment film obtained from the liquid crystal aligning agent composition of Comparative Examples 2 to 4 showed a brightness variation rate of 0.3% or more, confirming that the liquid crystal alignment characteristics were inferior to those of the above examples.

In addition, the liquid crystal alignment film obtained from the liquid crystal alignment agent composition of Comparative Example 5 using an excessive amount of an epoxy additive having the same structure as the Examples herein exhibits electrical properties at the same level as the Examples herein, but has a luminance variation rate of 0.6%, which is similar to the Examples herein. It was confirmed that it exhibited inferior liquid crystal orientation characteristics compared to .

Claims (19)

Contains a polyimide-based polymer matrix,
For specimens with a thickness of 590 Å or more and 610 Å or less, the remaining film rate according to Equation 1 below is -20% or more and -5% or less,
The residual film rate was determined by irradiating the specimen with ultraviolet rays of 254 nm at an exposure dose of 300 mJ/cm2 to 500 mJ/cm2 using an exposure machine equipped with a linear polarizer, and measuring the thickness (A1) of the specimen of the liquid crystal alignment film after exposure. Liquid crystal alignment film measured at 25° C. and 1 atm using a measuring instrument:
[Equation 1]
Residual film rate = (A0 - A1) / A0 * 100
In Equation 1 above,
A0 is the thickness (Å) of the specimen of the liquid crystal alignment film before exposure,
A1 is the thickness (Å) of the specimen of the liquid crystal alignment film after exposure.
According to paragraph 1,
In Equation 1, the thickness of the specimen of the liquid crystal alignment film is measured using a thickness meter (KLA TENCOR, D600).
According to paragraph 1,
A liquid crystal alignment film having a residual film ratio of -17% or more and -7% or less according to Equation 1 above.
delete According to paragraph 1,
In A0 of Equation 1, the liquid crystal alignment layer before exposure further includes an epoxy additive dispersed in a polyimide-based polymer matrix.
According to paragraph 1,
In A1 of Equation 1, the liquid crystal alignment layer after exposure further includes an epoxy additive bonded to a polyimide-based polymer matrix.
According to any one of paragraphs 5 or 6,
The epoxy additive is a glycidyl-based hetero compound, a liquid crystal alignment film.
According to paragraph 1,
In A1 of Equation 1, the liquid crystal alignment layer after exposure includes a complex in which the carbonyl functional group of the polyimide-based polymer matrix and the ethylene group of the epoxy additive are bonded through an ether bond.
According to clause 8,
The complex is a liquid crystal alignment film comprising one or more repeating units selected from the group consisting of Formula 1 and Formula 2:
[Formula 1]

[Formula 2]

In Formulas 1 and 2,
X ¹ to X ² are each independently a tetravalent organic group,
Y ¹ to Y ² are each independently a divalent organic group,
R' and R" are each independently hydrogen or a monovalent to tetravalent organic group.
According to clause 9,
A liquid crystal alignment film wherein the monovalent to tetravalent organic group is derived from a glycidyl-based hetero compound.
According to clause 9,
In Formulas 1 and 2,
A liquid crystal alignment film where X ¹ to X ² are tetravalent organic groups represented by the following formula (3):
[Formula 3]

In Formula 3 above,
R ¹ to R ⁶ are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms,
L ¹ is a direct bond, -O-, -CO-, -COO-, -S-, -SO-, -SO ₂ -, -CR ⁷ R ⁸ -, -(CH ₂ ) _Z -, -O(CH ₂ ) _Z O-, -COO(CH ₂ ) _Z OCO-, -CONH-, phenylene, or any one selected from the group consisting of a combination thereof,
In the above, R ⁷ and R ⁸ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or a fluoroalkyl group,
Z is an integer from 1 to 10.
According to paragraph 1,
The polyimide-based polymer matrix is a liquid crystal alignment film comprising one or more repeating units selected from the group consisting of polyimide repeating units, polyamic acid ester repeating units, and polyamic acid repeating units.
According to paragraph 1,
The polyimide-based polymer matrix is a liquid crystal alignment film comprising one or more repeating units selected from the group consisting of the following formulas 4 to 6:
[Formula 4]

[Formula 5]

[Formula 6]

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

In Formula 3 above,
R ¹ to R ⁶ are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms,
L ¹ is a direct bond, -O-, -CO-, -COO-, -S-, -SO-, -SO ₂ -, -CR ⁷ R ⁸ -, -(CH ₂ ) _Z -, -O(CH ₂ ) _Z O-, -COO(CH ₂ ) _Z OCO-, -CONH-, phenylene, or any one selected from the group consisting of a combination thereof,
In the above, R ⁷ and R ⁸ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or a fluoroalkyl group,
Z is an integer from 1 to 10,
Y ³ to Y ⁵ are each independently a divalent organic group represented by the following formula (7),
[Formula 7]

In Formula 7 above,
A is a tetravalent organic group represented by the above formula (3),
D ¹ and D ² are each independently an arylene group having 6 to 20 carbon atoms.
According to clause 9,
The complex further comprises a functional group represented by the following formula (8) or a functional group represented by the formula (9) at least at one end:
[Formula 8]

In Formula 8 above,
X ⁶ is a tetravalent organic group represented by the following formula (3),
[Formula 3]

In Formula 3 above,
R ¹ to R ⁶ are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms,
L ¹ is a direct bond, -O-, -CO-, -COO-, -S-, -SO-, -SO ₂ -, -CR ⁷ R ⁸ -, -(CH ₂ ) _Z -, -O(CH ₂ ) _Z O-, -COO(CH ₂ ) _Z OCO-, -CONH-, phenylene, or any one selected from the group consisting of a combination thereof,
In the above, R ⁷ and R ⁸ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or a fluoroalkyl group,
Z is an integer from 1 to 10,
Y ⁶ is a divalent organic group represented by the following formula (7),
[Formula 7]

In Formula 7 above,
A is a tetravalent organic group represented by the above formula (3),
D ¹ and D ² are each independently an arylene group having 6 to 20 carbon atoms,
R' and R" are each independently hydrogen or a monovalent to tetravalent organic group,
[Formula 9]

In Formula 9 above,
X ⁷ is a tetravalent organic group represented by the above formula (3),
Y ⁷ is a divalent organic group represented by the above formula (7),
R' and R" are each independently hydrogen or a monovalent to tetravalent organic group,
R ¹¹ and R ¹² are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms.
According to clause 13,
The polyimide-based polymer matrix is
A repeating unit containing at least one member selected from the group consisting of Formulas 10 to 12 below; Liquid crystal alignment film further comprising:
[Formula 10]

[Formula 11]

[Formula 12]

In Formulas 10 to 12,
At least one of R ¹³ and R ¹⁴ is an alkyl group having 1 to 10 carbon atoms, and the remainder is hydrogen,
X ⁸ to X ¹⁰ are each independently a tetravalent organic group represented by the following formula (3),
[Formula 3]

In Formula 3 above,
R ¹ to R ⁶ are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms,
L ¹ is a direct bond, -O-, -CO-, -COO-, -S-, -SO-, -SO ₂ -, -CR ⁷ R ⁸ -, -(CH ₂ ) _Z -, -O(CH ₂ ) _Z O-, -COO(CH ₂ ) _Z OCO-, -CONH-, phenylene, or any one selected from the group consisting of a combination thereof,
In the above, R ⁷ and R ⁸ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or a fluoroalkyl group,
Z is an integer from 1 to 10,
Y ⁸ to Y ¹⁰ are each independently a divalent organic group represented by the following formula (13),
[Formula 13]

In Formula 13 above,
R ¹⁵ and R ¹⁶ are each independently hydrogen, halogen, cyano, nitrile, alkyl with 1 to 10 carbon atoms, alkenyl with 1 to 10 carbon atoms, alkoxy with 1 to 10 carbon atoms, fluoroalkyl with 1 to 10 carbon atoms, or fluoroalkoxy having 1 to 10 carbon atoms,
p and q are each independently integers from 0 to 4,
L ² is a direct bond, -O-, -CO-, -S-, -SO ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -CONH-, -COO-, - (CH ₂ ) _y -, -O(CH ₂ ) _y O-, -O(CH ₂ ) _y -, -NH-, -NH(CH ₂ ) _y -NH-, -NH(CH ₂ ) _y O- , -OCH ₂ -C(CH ₃ ) ₂ -CH ₂ O-, -COO-(CH ₂ ) _y -OCO-, or -OCO-(CH ₂ ) _y -COO-,
y is an integer from 1 to 10,
k and m are each independently integers from 0 to 3,
n is an integer from 0 to 3.
According to clause 9,
The complex further includes a repeating unit including one or more selected from the group consisting of Formula 14 and Formula 15 below:
[Formula 14]

[Formula 15]

In Formulas 14 and 15 above,
X ¹¹ and X ¹² are each independently a tetravalent organic group represented by the following formula (3),
[Formula 3]

In Formula 3 above,
R ¹ to R ⁶ are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms,
L ¹ is a direct bond, -O-, -CO-, -COO-, -S-, -SO-, -SO ₂ -, -CR ⁷ R ⁸ -, -(CH ₂ ) _Z -, -O(CH ₂ ) _Z O-, -COO(CH ₂ ) _Z OCO-, -CONH-, phenylene, or any one selected from the group consisting of a combination thereof,
In the above, R ⁷ and R ⁸ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or a fluoroalkyl group,
Z is an integer from 1 to 10,
Y ¹¹ to Y ¹² are each independently a divalent organic group represented by the following formula (13),
[Formula 13]

In Formula 13 above,
R ¹⁵ and R ¹⁶ are each independently hydrogen, halogen, cyano, nitrile, alkyl with 1 to 10 carbon atoms, alkenyl with 1 to 10 carbon atoms, alkoxy with 1 to 10 carbon atoms, fluoroalkyl with 1 to 10 carbon atoms, or fluoroalkoxy having 1 to 10 carbon atoms,
p and q are each independently integers from 0 to 4,
L ² is a direct bond, -O-, -CO-, -S-, -SO ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -CONH-, -COO-, - (CH ₂ ) _y -, -O(CH ₂ ) _y O-, -O(CH ₂ ) _y -, -NH-, -NH(CH ₂ ) _y -NH-, -NH(CH ₂ ) _y O- , -OCH ₂ -C(CH ₃ ) ₂ -CH ₂ O-, -COO-(CH ₂ ) _y -OCO-, or -OCO-(CH ₂ ) _y -COO-,
y is an integer from 1 to 10,
k and m are each independently integers from 0 to 3,
n is an integer from 0 to 3,
R' and R" are each independently hydrogen or a monovalent to tetravalent organic group.
According to paragraph 1,
A liquid crystal alignment film wherein the polyimide-based polymer matrix has a weight average molecular weight (measured by GPC) of 5000 g/mol to 100000 g/mol.
A liquid crystal display device comprising the liquid crystal alignment layer of claim 1.
delete