KR101976864B1 - Method for manufacturing liquid crystal display device and liquid crystal display device manufactured by using the same - Google Patents

Abstract

The present invention provides a method of manufacturing a liquid crystal display device using a precursor of a liquid crystal precursor and capable of improving the performance and reliability of a liquid crystal display device by inducing and stabilizing the pretilt angle of a liquid crystal without a linear alignment treatment process, Thereby providing a display element.

Description

[0001] The present invention relates to a method of manufacturing a liquid crystal display device, and a liquid crystal display device using the same. BACKGROUND ART < RTI ID = 0.0 > [0002]

The present invention relates to a method for manufacturing a liquid crystal display element and a liquid crystal display element manufactured using the method.

In order to induce the vertical alignment of the liquid crystal on the surface of the substrate in the conventional vertical alignment type liquid crystal display device, a vertically oriented polymer such as polyimide is applied in a solution state and then a solidified film is used. FIG. 1 is a process diagram schematically showing a manufacturing process of a liquid crystal display device using a polyimide thin film for vertical alignment of a liquid crystal. 1, the electrodes 2 and 2 'are patterned as a transparent conductive film for applying an electric field on the first and second substrates 1 and 1', respectively (S1) The alignment agent is applied in the form of a thin film in the form of a solution and then baked at a high temperature to form polymer alignment layers 3 and 3 ' After assembling at intervals, liquid crystal was injected to form a liquid crystal layer 4 to manufacture a liquid crystal display device (S3). At this time, the liquid crystal molecules in the liquid crystal layer 4 are arranged perpendicular to the substrate surface due to the effect of the polymeric alignment agent.

However, when a liquid crystal device is manufactured by the above-described method, since the liquid crystal has no pretilt angle in a specific direction, the direction of the liquid crystal that reacts when an electric field is applied is random, And problems such as a decrease in speed have occurred.

As a method for solving such a problem and inducing the photo-alignment of liquid crystal, a method using a compound containing an azo group has been proposed. Specifically, a polymer material having an azo compound introduced into its main chain or side chain is coated on a substrate to form linearly polarized light, a mono-molecular azo compound layer is formed on the substrate to form a liquid crystal cell after irradiating the linearly polarized light, or A method in which a mono-molecular azo compound is coated on a substrate, a liquid crystal is injected to form a liquid crystal cell, and then linearly polarized light is irradiated to control the vertical alignment of the liquid crystal.

However, these methods are difficult to apply to devices requiring a permanent orientation state due to low heat and light stability of orientation, and are applicable only to devices that require a function to reversibly change the orientation state due to the wavelength of light to be irradiated It is possible. Also, these methods commonly require a pretreatment process for coating the alignment agent on the substrate.

In addition to these methods, a liquid crystal cell is prepared by mixing a dichroic absorption dye on an alignment film and then coating the substrate, or a liquid crystal cell is prepared using a liquid crystal mixture containing a dichroic absorption dye. Methods of controlling homogeneous horizontal alignment of liquid crystal by inducing anisotropy of orientational order of dye molecules by irradiating strong laser linearly polarized light have been proposed.

In order to improve the characteristics of the liquid crystal device such as reaction speed, brightness, contrast ratio, and driving voltage, it is required to induce and stabilize the liquid crystal pretilt angles. In order to improve the viewing angle characteristics of the liquid crystal device, . In order to achieve this object, rubbing of the orientation layer, formation of protrusions, fine patterning of electrodes, and surface stabilization technology using photoreactive liquid crystal have been proposed.

However, these methods do not provide a complete technical solution due to process problems, side effects due to added technology, and the like.

U.S. Patent No. 4,974,941 (registered on December 4, 1990) U.S. Patent 5,032,009 (registered on July 16, 1991)

It is an object of the present invention to improve the stability and stability of temperature and light by inducing and stabilizing the vertical alignment of the liquid crystal having a pretilt angle in a specific direction without a line alignment treatment process to improve the performance and reliability of the liquid crystal display device And to provide a liquid crystal display device using the same, and a liquid crystal display device using the same.

It is still another object of the present invention to provide a linear stabilizer for a liquid crystal which is used in the production of the liquid crystal display device and a method for linearly guiding a liquid crystal using the same.

According to an embodiment of the present invention, there is provided a method of manufacturing a plasma display panel, comprising: forming an electrode on a first substrate and a second substrate, respectively; The first substrate and the second substrate each including the first and second electrodes are bonded to each other with the electrodes facing each other, and then the liquid crystal layer forming composition is injected into the space between the first substrate and the second substrate, A composition for forming a liquid crystal layer was dropped on any one of a first substrate and a second substrate each including a first electrode and a second electrode under vacuum to form a liquid crystal layer and then the remaining substrates were bonded so that the electrodes face each other, Producing; And inducing a preliminary square of the liquid crystal by light irradiation on the assembly,

Wherein the composition for forming a liquid crystal layer comprises a liquid crystal host and a pretilt angle stabilizer for liquid crystal, wherein the pretilt angle stabilizer for liquid crystal comprises at least two cyclic functional groups selected from the group consisting of an aromatic group, an alicyclic group and a heterocyclic group, - the cis-light has a structure including a rigid-core portion including a plasticizer and a flexible group bonded to the end or side of the rigid-core portion, and having a molecular weight of 380 to 1,000 g / mol and a solubility in a liquid crystal host 0.01 to 3% by weight based on the total weight of the liquid crystal display device.

In the above-mentioned production method, the linear stabilizer for linear stabilization of the liquid crystal may be contained in an amount of 0.05 to 2% by weight based on the total weight of the composition for forming a liquid crystal layer.

In the linear quadrangle stabilizer of the liquid crystal, the trans-cis photochromic group may be at least one member selected from the group consisting of azo, azo, and imine groups.

Also, the above-mentioned rigid-core portion includes 4 to 6 cyclic functional groups selected from the group consisting of an aromatic group, an alicyclic group and a heterocyclic group, and a trans-cis photochromic group, wherein the cyclic functional groups are directly connected to each other, An alkylene group having 1 to 20 carbon atoms, an alkenyl-diyl group having 2 to 20 carbon atoms, an alkyne-diyl group having 2 to 30 carbon atoms, a fluoroalkylene group having 1 to 20 carbon atoms, a hetero atom and a heteroalkyl group having 1 to 20 carbon atoms And a molecular weight of the rigid-core portion may be 320 to 800 g / mol.

The above-mentioned rigid-core portion may contain, as a substituent for a hydrogen atom in the rigid-core portion, 1 to 6 functional groups selected from the group consisting of a halogen group, an alkyl group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, .

The flexible group is a hydrocarbon group of 1 to 20 carbon atoms substituted or unsubstituted with a halogen group; A heteroalkyl group having 1 to 20 carbon atoms which contains at least one heteroatom selected from the group consisting of N, O, P, S and Si in the functional group and is substituted or unsubstituted with a halogen group; And a combination thereof.

The linear quadrangle stabilizer of the liquid crystal may comprise a compound of the following formula:

[Chemical Formula 1]

In this formula,

A and B are each independently a trans-cis-optic transition group selected from the group consisting of an azo group, an azooxy group and an imine group,

R ₁ and R ₂ are each independently a hydrocarbon group of 1 to 20 carbon atoms substituted or unsubstituted with a halogen group; A heteroalkyl group having 1 to 20 carbon atoms which contains at least one heteroatom selected from the group consisting of N, O, P, S and Si in the functional group and is substituted or unsubstituted with a halogen group; And combinations thereof,

Ra to Rc are each independently selected from the group consisting of a halogen group, an alkyl group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, and a combination thereof,

X is a functional group of formula (I)

[Formula 1a]

(Wherein X ₁ represents an alkylene group having 1 to 20 carbon atoms, an alkenyl-diyl group having 2 to 20 carbon atoms, an alkyne-diyl group having 2 to 20 carbon atoms, a fluoroalkylene group having 1 to 20 carbon atoms, a carbonyl group, Wherein R _d is selected from the group consisting of a halogen group, an alkyl group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, and an alkyl group having 1 to 10 carbon atoms; P is an integer of 0 to 4, and x is an integer of 0 or 1,

Y is a functional group of the following formula (1b)

[Chemical Formula 1b]

Y ₁ represents an alkylene group having 1 to 20 carbon atoms, an alkene-diyl group having 2 to 20 carbon atoms, an alkyne-diyl group having 2 to 20 carbon atoms, a fluoroalkylene group having 1 to 20 carbon atoms, a carbonyl group, Re is a group selected from the group consisting of a halogen group, an alkyl group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, and an alkyl group having 1 to 10 carbon atoms, Q is an integer of 1 to 4, and y is an integer of 0 or 1,

a to c are each independently an integer of 0 or 1, and

l to n are each independently an integer of 0 to 4;

The linear quadrangle stabilizer of the liquid crystal may be selected from the group consisting of an azo compound represented by the following formula (2), a diazo or triazo compound represented by the following formula (3), an azooximide compound represented by the following formula (4) Lt; RTI ID = 0.0 > of: < / RTI >

(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

In this formula,

A and B are each independently a trans-cis-optic transition group selected from the group consisting of an azo group, an azooxy group and an imine group,

R ₁ and R ₂ each independently represent an alkyl group having 1 to 20 carbon atoms, which is substituted or unsubstituted with a fluoro group; Containing a functional group having a heteroatom selected from the group consisting of a carbonyl group, an ether group, a thioether group, an ester group, a thioester group, an amine group, an imine group, an azooxy group and an azo group, To 20 heteroalkyl groups; And combinations thereof. ≪ RTI ID = 0.0 >

Each of R _a to R _e is independently selected from the group consisting of a halogen group, an alkyl group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms,

X ₁₁ and Y ₁₁ each independently represent an alkylene group having 1 to 20 carbon atoms, an alkene-diyl group having 2 to 20 carbon atoms, an alkyne-diyl group having 2 to 20 carbon atoms, a fluoroalkylene group having 1 to 20 carbon atoms, An ester group, an amine group and an imine group,

X ₁₂ and Y ₁₂ are both an azo group or one of them is an azo group and the other is an alkylene group having 1 to 20 carbon atoms, an alkenyl-diyl group having 2 to 20 carbon atoms, an alkyne-diyl group having 2 to 20 carbon atoms , A fluoroalkylene group having 1 to 20 carbon atoms, an ether group, an ester group, an amine group and an imine group,

X ₁₃ and Y ₁₃ are both imine groups or one of them is an imine group and the other is an alkylene group having 1 to 20 carbon atoms, an alkene-diyl group having 2 to 20 carbon atoms, an alkyne-diyl group having 2 to 20 carbon atoms , A fluoroalkylene group having 1 to 20 carbon atoms, an ether group, an ester group, an amine group, and an azo group,

1 to n, p and q are each independently an integer of 0 to 4, and

x and y are each independently an integer of 0 or 1;

In addition, the linear quadrangle stabilizer of the liquid crystal may include a rigid-core portion including two or more cyclic functional groups selected from the group consisting of an aromatic group, an alicyclic group and a heterocyclic group, and a trans- A compound having a structure comprising a flexible group bonded to the end or side of the core moiety and having a molecular weight of 380 to 1,000 g / mol and a solubility in the liquid crystal host of 0.01 to 3% by weight, said compound having a chiral group It can be more inclusive.

In addition, the pretilt angle stabilizer may include a compound of the following formula (6): < EMI ID =

[Chemical Formula 6]

In this formula,

R is an alkyl group having 1 to 20 carbon atoms,

X ₁₄ and Y ₁₄ each independently represent a single bond, an alkenyl-diyl group having 2 to 20 carbon atoms, an alkynyl-diyl group having 2 to 20 carbon atoms, a carbonyl group, an ether group, a thioether group, an ester group, a thioester group, , An imino group, an azooxy group, and an azo group, and

n is an integer of 1 to 20;

Further, the pre-shaping square induction can be carried out by any one of the following methods:

1) a method of irradiating light using oblique incident light whose incidence direction of light is inclined at an angle of less than 90 DEG with respect to the substrate surface

2) irradiating the substrate with light in the vertical direction to induce vertical alignment of the liquid crystal, and then performing secondary light irradiation for irradiating obliquely incident light whose incidence direction of light is inclined at an angle of less than 90 DEG with respect to the substrate surface Way

3) a method of irradiating light in the vertical direction of the substrate to induce the vertical alignment of the liquid crystal, then applying an electric field to the assembly in the vertical alignment state of the liquid crystal, and performing second light irradiation

4) A method of irradiating oblique incidence light in which the direction of incidence of light is inclined at an angle of less than 90 ° with respect to the substrate surface by using a vertically aligned substrate having no pre-scan angle formed as the first and second substrates in the manufacture of the assembly

5) A vertically aligned substrate and a liquid crystal having a negative dielectric constant anisotropy were used as the first and second substrates in the manufacture of the assembly, and light irradiation was performed under the application of a vertical electric field when the linearly polarized light was guided How to induce a square box

6) A method in which a substrate having a horizontally oriented film rubbed as a first and a second substrate during manufacture of the assembly is used and light irradiation is performed to induce a pretilt angle

7) A method of inducing pre-warping square by irradiating light with the rubbed horizontally oriented film in the production of assembly and controlling the arrangement of liquid crystal by applying electric field

After the injection of the composition for forming a liquid crystal layer, the liquid crystal display element is manufactured at a temperature higher by 1 to 20 DEG C than the nematic-isotropic phase transition temperature of the mixture containing the liquid crystal host and the liquid crystal precursor square stabilizer And a step of inducing homogenization of the composition for forming a liquid crystal layer in which the assembly is heated and then cooled.

In the method of manufacturing a liquid crystal display device, at least one of the first and second electrodes may have a multi-domain fine pattern.

In the method of manufacturing a liquid crystal display element, the concave or convex lens may be used to irradiate the linearly polarized light so that the incidence direction of the light becomes oblique incident light inclined at an angle of less than 90 degrees with respect to the substrate surface, The second directional light is irradiated with light in the vertical direction of the substrate to induce the vertical alignment of the liquid crystal, and then a concave or convex lens is applied to irradiate the oblique incident light inclined at an angle of less than 90 deg. Can be carried out by inspection.

In addition, the above-mentioned pretilt angle guidance may be performed by irradiating light using a lens array of a pixel shape.

According to another embodiment of the present invention, there is provided a liquid crystal display device manufactured by the above manufacturing method.

According to another embodiment of the present invention, there is provided a polymer electrolyte fuel cell comprising a rigid-core portion comprising at least two cyclic functional groups selected from the group consisting of an aromatic group, an alicyclic group and a heterocyclic group, and a trans- A liquid crystal precursor square stabilizer having a structure comprising a flexible group bonded to the end or side of the core and having a molecular weight of from 380 to 1,000 g / mol and a solubility in the liquid crystal host of from 0.01 to 3% by weight, to provide.

According to another embodiment of the present invention, there is provided a method for inducing a pretilt angle of a liquid crystal by irradiating a composition for forming a liquid crystal layer including a pretilt angle stabilizer of a liquid crystal and a liquid crystal host.

Other details of the embodiments of the present invention are included in the following detailed description.

The vertical alignment liquid crystal display device according to the present invention is able to simplify the manufacturing process of the vertical alignment liquid crystal display device by inducing and stabilizing the vertical alignment and the pre-alignment angle of the liquid crystal having stability to temperature and light, The performance and reliability of the display element can be improved.

FIG. 1 is a process diagram schematically showing a manufacturing process of a conventional liquid crystal display device.
2 is a schematic view illustrating a process of manufacturing a liquid crystal display device according to an embodiment of the present invention.
FIG. 3 is a conceptual view schematically showing the formation of a pre-scan square by the irradiation of oblique light.
4A and 4B are conceptual diagrams showing a liquid crystal pre-scan square multi-domain which can be manufactured by multiple oblique light irradiation, respectively.
5A to 5C are schematic diagrams schematically showing the path of the irradiation light when the circular convex lens 1 is placed on the liquid crystal cell as a mask and incident light perpendicular to the substrate surface of the cell is irradiated.
6A to 6C are schematic views schematically showing the path of the irradiation light when the circular concave lens 1 is placed on the liquid crystal cell as a mask and the incident light perpendicular to the substrate surface of the cell is irradiated.
7A and 7B are diagrams showing a case where the light irradiation is performed by placing the liquid crystal cell in the region (B) by using the convex lens of FIG. 5 or when the light irradiation is performed using the concave lens of FIG. 5, Fig. 7A shows the direction of the vertical cross section of the lens, and Fig. 7B shows the direction of the liquid crystal pretilt angle observed in the direction perpendicular to the substrate surface. In Figs. 7A and 7B, the arrow indicates the direction in which the liquid crystal direct is inclined.
FIGS. 8A and 8B show the direction of the linear polarization of the liquid crystal when the liquid crystal cell is placed in the region (A) by using the convex lens of FIG. 5 and light irradiation is performed. FIG. 8B shows the direction of the liquid crystal pretilt angle observed in the direction perpendicular to the substrate surface. 8A and 8B, the arrow indicates the direction in which the liquid crystal direct is inclined.
9A to 9C are photographs showing the result of observing the liquid crystal alignment before, after and immediately after the irradiation of the liquid crystal display device of Comparative Example 2-2 with a polarization microscope, and Fig. 9D shows the alignment of the liquid crystal molecules This is a photograph showing the results observed through a conoscopic image.
10A and 10B are photographs showing the results of observing the liquid crystal alignment before and after irradiation of ultraviolet rays in the liquid crystal display element of Example 1 with a polarizing microscope.
11A and 11B are polarization microscopic photographs microscopically and macroscopically observing the switching behavior of the liquid crystal upon application of an electric field after inducing vertical orientation of the liquid crystal in the liquid crystal display element of Example 1. Fig.
12A shows a state in which the composition for forming a liquid crystal layer is injected into the cell fabricated in Example 1 in order to realize multi-domainization of the pre-scan square, and then the liquid crystal vertical alignment state on the surface of the substrate immediately after the vertical alignment of the liquid crystal 12B is a polarimetric microscope photograph showing a result of observing the state of alignment of liquid crystals after a part of the liquid crystal cell is covered with a photomask and then light is irradiated using oblique incident light of 10 DEG, 12c is a polarizing microscope observation image (black square: photomask) showing the result of observing the alignment state of the liquid crystal after irradiating obliquely incident light of 10 DEG in the opposite direction by changing the position of the portion covered with the photomask.
FIG. 13A is a photograph of a polarized light microscope in which the liquid crystal alignment state of the liquid crystal display device of Example 2 is observed after the vertical alignment of the liquid crystal is induced, and FIG. 13B is a polarized light microscopic image of the liquid crystal alignment state after application of a vertical electric field to the vertically aligned liquid crystal FIG. 13C is a photograph of a polarized microscope observing defect removal with time after application of a vertical electric field. FIG.
Figs. 14A to 14C are photographs of polarization-on-off switching characteristics of a device according to application of an electric field after linear polarization induction in the liquid crystal display device of Example 2. Fig.
15A is a photograph of a polarizing microscope observed immediately after the liquid crystal vertical alignment in the liquid crystal display element of Example 3, and Figs. 15B and 15C are photographs showing the switching behavior of the liquid crystal when the electric field in the vertical direction is applied to the vertically aligned liquid crystal cell to be.
Figs. 16A to 16C are photographs of a device for observing the on-off switching characteristics of a liquid crystal display element according to Embodiment 3 after application of an electric field after polarization-guiding the front end thereof with a polarization microscope. Fig.
FIG. 17A is a photograph of a polarizing microscope observed immediately after the liquid crystal vertical alignment in the liquid crystal display element of Example 4, and FIGS. 17B and 17C are photographs showing the switching behavior of the liquid crystal when the electric field is applied to the vertically aligned liquid crystal cell to be.
FIGS. 18A to 18C are photographs of a device for observing the on-off switching characteristics of a liquid crystal display element according to Embodiment 4 after application of an electric field after polarization-induced straightening, using a polarization microscope.
19A is a photograph of a polarizing microscope observed immediately after the liquid crystal vertical alignment in the liquid crystal display element of Example 5. Figs. 19B and 19C are photographs showing the switching behavior of the liquid crystal when the electric field in the vertical direction is applied to the vertically aligned liquid crystal cell to be.
FIGS. 20A to 20C are photographs of polarization characteristics of the on-off switching device according to application of an electric field after the linear polarization induction in the liquid crystal display device of Example 5 is observed. FIG.
Figs. 21A and 21B are polarization micrographs respectively showing a state in which the liquid crystal display element of Embodiment 6 is horizontally aligned before light irradiation and a state of vertically aligned after light irradiation, respectively. Fig.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited thereto, and the present invention is only defined by the scope of the following claims.

Unless otherwise specified herein, the term "aromatic group" means an aromatic group that does not contain a hetero atom such as a benzene group, a naphthalene group, an anthracene group, or contains a hetero atom such as a pyridine group, a thiophene group and the like.

In the present specification, unless otherwise specified, all the compounds or substituents may be substituted or unsubstituted. Herein, the term "substituted" means that hydrogen is substituted with at least one substituent selected from the group consisting of a halogen group, a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an amino group, a thio group, a methylthio group, an alkoxy group, an aldehyde group, Substituted with any one selected from the group consisting of an alkyl group, a ketone group, an alkyl group, a perfluoroalkyl group, a cycloalkyl group, a heterocycloalkyl group, an allyl group, a benzyl group, an aryl group, a heteroaryl group, it means.

In the present specification, unless otherwise specified, the term "a combination thereof" means a compound wherein at least two functional groups are a single bond, a double bond (ethylene group), a triple bond (acetylene group), an alkylene group having 1 to 20 carbon atoms -CH ₂ -), ethylene (-CH ₂ CH ₂ -), and the like), fluoro-alkylene group having 1 to 20 carbon atoms (e.g., methylene fluoro (-CF ₂ -), ethylene (-CF ₂ fluoro CF ₂ -), etc.), a hetero atom such as N, O, P, S, or Si or a functional group containing the same (specifically, a carbonyl group (-C═O-) , An ester group (--COO-), --S--, an amine group (--NH--) or --N.dbd.N--), or two or more functional groups are condensed , It means that they are connected.

Also, in this specification, when a portion of a layer, a film, a region, a substrate, or the like is referred to as being "on" another portion, it includes not only the portion directly above another portion but also another portion in between. On the other hand, when a part is referred to as being "directly on" another part, it means that there is no other part in the middle. On the contrary, when a portion such as a layer, a film, an area, a substrate, or the like is referred to as being 'under' another portion, this includes not only a portion directly under another portion but also another portion in between. On the other hand, when a part is "directly underneath" another part, it means that there is no other part in the middle.

Since the orientation stability of the liquid crystal may vary depending on the molecular weight of the linear quadrangle stabilizer of the liquid crystal used and the solubility in the host liquid crystal, the molecular weight of the linear quadratic stabilizer of the liquid crystal, Solubility control in liquid crystals is necessary.

As a result of experiment of induction and stability of vertical orientation of liquid crystal according to the molecular weight and solubility of the liquid crystal precursor square stabilizer, in the case of the orientation-inducing agent having a small molecular weight and high solubility to the host liquid crystal, And the stability to light is low, and as a result, it is easily returned to the state before the light irradiation, so that it is difficult to apply to a device which requires maintenance of a specific orientation state permanently. On the other hand, when the orientation inducing agent having a relatively large molecular weight and a low solubility to the host liquid crystal is used, the alignment state of the liquid crystal formed after the optical treatment exhibits excellent stability to temperature and light.

Accordingly, in the present invention, a liquid crystal preliminary square stabilizer having an optimized molecular weight and solubility in a liquid crystal host is used in the present invention, in which a light-modifiable group capable of forming a fine aggregate by trans- Thus, it is possible to induce the vertical alignment of the liquid crystal by light irradiation without the alignment film formation step of the substrate, and to control the orientation of the liquid crystal permanently by multi-patterning of the pretilt angle, And the like.

That is, a method of manufacturing a liquid crystal display device according to an embodiment of the present invention includes: an electrode forming step of forming first and second electrodes respectively on a first substrate and a second substrate; The first substrate and the second substrate each including the first and second electrodes are bonded to each other with the electrodes facing each other, and then the liquid crystal layer forming composition is injected into the space between the first substrate and the second substrate, A composition for forming a liquid crystal layer was dropped on any one of a first substrate and a second substrate each including a first electrode and a second electrode under vacuum to form a liquid crystal layer and then the remaining substrates were bonded so that the electrodes face each other, Producing; And inducing a pre-scan square of the liquid crystal by light irradiation on the assembly.

In the above manufacturing method, the composition for forming a liquid crystal layer includes a liquid crystal host and a pretilt angle stabilizer for liquid crystal, wherein the pretilt angle stabilizer for liquid crystal is at least two selected from the group consisting of an aromatic group, an alicyclic group, and a heterocyclic group A rigid-core portion comprising at least one cyclic functional group, and a trans-cis photochromic group; And a compound having a structure including a flexible group bonded to the terminal or side of the rigid-core portion and having a molecular weight (Mw) of 380 to 1,000 g / mol and a solubility in a liquid crystal host of 0.01 to 3% Compound for linear stabilizer for liquid crystals "). In this case, the solubility should be clearly distinguished from the concentration used in the experiment by mixing with the host liquid crystal, and it means the maximum amount of dissolution of the added compound for the liquid crystal precursor square stabilizer in the host liquid crystal. In this specification, the solubility means the solubility at 25 ° C unless otherwise specified.

In the compound for a linear quadrangle stabilizer for a liquid crystal described above, the trans-cis photochromic group is a functional group capable of forming a fine molecular aggregate by allowing the compound to form a light-curable compound by light irradiation. The azo group, N = N), an azoxy group (-N (O) = N-), and an imine group (-C = N-). The linear stabilizer of the liquid crystal according to the present invention may include one or more of the above-mentioned trans-cis light stabilizers, and the trans-cis light in one molecule of the linear quadratic stabilizer of the liquid crystal It may contain one or two or more properties.

The cyclic group is an annular functional group selected from the group consisting of an aromatic group, a cycloaliphatic group and a heterocyclic group.

Specifically, the aromatic group may be a monocyclic or polycyclic aromatic group having 6 to 30 carbon atoms, and more specifically, a phenyl group, a naphthalene group, and the like may be cited, but the present invention is not limited thereto. The alicyclic group may specifically be a monocyclic or polycyclic cycloalkyl group or cycloalkenyl group having 6 to 30 carbon atoms, and more specifically, a cyclobutyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, a cyclopropenyl group , A cyclobutenyl group, a cyclopentenyl group, and the like, but are not limited thereto. The heterocyclic group is specifically a saturated or unsaturated heterocyclic group having 6 to 30 carbon atoms containing at least one heteroatom selected from the group consisting of oxygen (O), nitrogen (N), sulfur (S) and phosphorus (P) Specific examples of the unsaturated ring group include pyrrolidine, oxolane, thiolane, piperidine, azepane, pyrrole, furan, thiophene, pyridine, pyran, But is not limited thereto.

The above-mentioned cyclic functional group is directly or indirectly connected with the trans-cis light to form the central skeleton of the rigid-core of the liquid crystal precursor square stabilizer. Further, the cyclic functional group affects the formation of an effective and stable molecular micro-aggregate in association with the vertical alignment of the liquid crystal and the linear square stabilization, and it is preferable that the cyclic functional group has 2 or more, preferably 4 or more Preferably 4 to 6, and even more preferably 4 or 5 in number. When the number of the cyclic functional groups is less than 2, the vertical alignment is not induced or the vertical orientation of the derived liquid crystal and the stability of the linear square of heat and light are low, which is not preferable for application to a device requiring a permanent alignment state.

The two or more cyclic functional groups contained in the central skeleton of the rigid-core may be directly connected to each other, or may be an alkylene group having 1 to 20 carbon atoms (e.g., a methylene group (-CH ₂ -), an ethylene group (-CH ₂ CH ₂ -, and the like), an alkenyl-diyl group having 2 to 20 carbon atoms including a carbon-carbon double bond (e.g., an ethene-diyl group (-C═C-)), (For example, an ethyne-diyl group (-C≡C-)), a fluoroalkylene group having 1 to 20 carbon atoms (for example, a fluoromethylene group (-CF ₂ -), (-CF ₂ CF ₂ -)), a hetero atom such as N, O, P, S, or Si, or a functional group containing the hetero atom (specifically, a carbonyl group (-C (= , Ether, -O-, thioether, -S-, ester, -COO-, thioester, -COS-, amine group (-NH-) , An imine group (-CH = N-), an azooxy group, or an azo group (-N = N-) It may be connected by a linking group such as a hetero-alkylene group) having 1 to 20 carbon atoms.

Also, one or more, preferably 1 to 6, hydrogen atoms in the cyclic functional group may be substituted with an alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, etc.), a halogen group, a fluoroalkyl group having 1 to 10 carbon atoms A trifluoromethyl group, etc.), and a combination of these groups.

It is preferred that the rigid-core portion of the linear quadrangle stabilizer of the liquid crystal comprising the light modifying group, the cyclic functional group and optionally the linking group has a molecular weight (Mw) of 320 to 800 g / mol. When the molecular weight of the rigid-core portion is less than 320 g / mol, the stability of the liquid crystal alignment induced by light irradiation may be significantly deteriorated due to the high solubility in the liquid crystal host. When the molecular weight exceeds 800 g / mol, Which is undesirable.

In addition, a flexible group which is easily dissolved in the liquid crystal host and controls the solubility with the liquid crystal can be bonded to the terminal or side of the rigid-core part.

Specifically, the flexible group is a hydrocarbon group having 1 to 20 carbon atoms which is substituted or unsubstituted with a halogen group, or contains at least one heteroatom selected from the group consisting of N, O, P, S and Si in a functional group, A substituted or unsubstituted C1 to C20 heteroalkyl group, or a combination group consisting of a combination of the hydrocarbon group and the hetero atom-containing groups. Preferably an alkyl group having 1 to 20 carbon atoms which is unsubstituted or substituted with a fluorine atom; Containing a functional group having a heteroatom selected from the group consisting of a carbonyl group, an ether group, a thioether group, an ester group, a thioester group, an amine group, an imine group, an azooxy group and an azo group, To 20 heteroalkyl groups; And a combination thereof. More preferably, the flexible group is an alkyl group having 1 to 20 carbon atoms, a fluoroalkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a carboxy group, a (carboxyalkyl group) having 1 to 20 carbon atoms, May be selected from the group consisting of an oxygen group (e.g., ethylene oxide group, propylene oxide group, etc.), (amino group having 1 to 20 carbon atoms), a thioalkyl group having 1 to 20 carbon atoms, and a thioester group, May be an alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms.

It is preferable that the flexibility group is contained in an amount that satisfies the conditions of the solubility of the compound for the linear quadratic stabilizer of liquid crystal in the liquid crystal host in the range of 0.01 to 3 wt%.

The compound for the linear quadrangle stabilizer of the liquid crystal may further include a functional group capable of controlling the solubility by lowering packing of molecules as a substituent for the rigid-core portion together with the flexible group. Specifically, the functional group is composed of an alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group and the like), a halogen group, a fluoroalkyl group having 1 to 10 carbon atoms (e.g., trifluoromethyl group) Group, and the functional group is preferably contained in the content of 1 to 6 in the rigid-core portion.

The compound for the linear quadratic stabilizer of the liquid crystal may further include a chiral group together with the flexible group. Since introduction of the chiral group is not limited to the vertical orientation induction and the pretilt angle stabilization which are the object of the present invention, it can be usefully used when the chiral property is required for the additional purpose. It is preferable that the chiral group is contained in such an amount that the solubility of the liquid crystal precursor square stabilizer in the liquid crystal host is 0.01 to 3% by weight.

The compound for a linear quadrangle stabilizer of the liquid crystal as described above does not always have to exhibit liquid crystallinity, and it is preferable that the rigid-core portion is linear and the symmetry is high in order to improve the stability of the induced liquid crystal alignment.

It is preferable that the compound for linear stabilizer of the liquid crystal having the above-mentioned structural characteristics has a molecular weight (Mw) of 380 to 1,000 g / mol and a solubility in a liquid crystal host of 0.01 to 3% by weight. The linear stabilizer of the liquid crystal precursor satisfies both the molecular weight and solubility conditions described above and can induce a good liquid crystal alignment and can improve the stability of the liquid crystal alignment to heat and light to maintain the permanent alignment state. More preferably, it has a molecular weight of 390 to 900 g / mol, a solubility in a liquid crystal host at room temperature of 0.1 to 2% by weight, more preferably a molecular weight of 400 to 800 g / mol and a solubility in a liquid crystal host of 0.1 To 1.5% by weight.

More specifically, the liquid crystal precursor square stabilizer usable in the present invention may comprise a compound having the structure of the following formula (1) under conditions that satisfy the above-mentioned molecular weight and solubility conditions for the liquid crystal host:

[Chemical Formula 1]

In this formula,

A and B are the same as defined above as trans-cis photochromic groups. Specifically, A and B are each independently selected from the group consisting of an azo group, an azooxy group and an imine group.

R ₁ and R ₂ are the same as defined above as a flexible group. Specifically, R ₁ and R ₂ each independently represent a hydrocarbon group of 1 to 20 carbon atoms which is substituted or unsubstituted with a halogen group; A heteroalkyl group having 1 to 20 carbon atoms which contains at least one heteroatom selected from the group consisting of N, O, P, S and Si in the functional group and is substituted or unsubstituted with a halogen group; And a combination thereof, preferably an alkyl group having 1 to 20 carbon atoms which is unsubstituted or substituted with a fluorine atom; Containing a functional group having a heteroatom selected from the group consisting of a carbonyl group, an ether group, a thioether group, an ester group, a thioester group, an amine group, an imine group, an azooxy group and an azo group, To 20 heteroalkyl groups; And a combination thereof. More preferably an alkyl group having 1 to 20 carbon atoms, a fluoroalkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a carboxy group, a (carboxyalkyl group) having 1 to 20 carbon atoms, an alkylene oxide group having 2 to 10 carbon atoms (Alkyl group having 1 to 20 carbon atoms) amino group, a thioalkyl group having 1 to 20 carbon atoms, and a thioester group, and still more preferably 1 to 20 carbon atoms Or an alkoxy group having 1 to 20 carbon atoms.

Ra to Rc are substituents for an aromatic group which is a cyclic functional group constituting the rigid-core portion. Specifically, Ra to Rc each independently represent a halogen group, an alkyl group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, ≪ / RTI >

X may be a functional group of formula (I)

[Formula 1a]

(Wherein X ₁ represents an alkylene group having 1 to 20 carbon atoms, an alkenyl-diyl group having 2 to 20 carbon atoms, an alkyne-diyl group having 2 to 20 carbon atoms, a fluoroalkylene group having 1 to 20 carbon atoms, a carbonyl group, An ether group, an ester group, a thioester group, an amine group, an imine group, an azooxy group and an azo group, preferably a methylene group, an ethylene group, an ethene-diyl group, an ethyne-diyl group, , A fluoroethylene group, an ether group, an ester group, an amine group, an imine group and an azo group,

R _d is selected from the group consisting of a halogen group, an alkyl group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms,

p is an integer of 0 to 4, and x is an integer of 0 or 1)

Y may be a functional group of the following formula (1b).

[Chemical Formula 1b]

Y ₁ represents an alkylene group having 1 to 20 carbon atoms, an alkene-diyl group having 2 to 20 carbon atoms, an alkyne-diyl group having 2 to 20 carbon atoms, a fluoroalkylene group having 1 to 20 carbon atoms, a carbonyl group, An ether group, an ester group, a thioester group, an amine group, an imine group, an azooxy group and an azo group, preferably a methylene group, an ethylene group, an ethene-diyl group, an ethyne-diyl group, , A fluoroethylene group, an ether group, an ester group, an amine group, an imine group and an azo group,

Re is selected from the group consisting of a halogen group, an alkyl group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, and a combination thereof,

q is an integer of 1 to 4, and y is an integer of 0 or 1,

a to c are each independently an integer of 0 or 1, and

l to n are each independently an integer of 0 to 4;

As a more preferred example, the linear quadratic stabilizer of the liquid crystal may include an azo compound represented by the following formula (2)

(2)

Wherein R, R _1, R _2, Ra, Rc, Rd, Re, l, p, q, n, x and y are the same as defined above,

X ₁₁ and Y ₁₁ each independently represent an alkylene group having 1 to 20 carbon atoms, an alkene-diyl group having 2 to 20 carbon atoms, an alkyne-diyl group having 2 to 20 carbon atoms, a fluoroalkylene group having 1 to 20 carbon atoms, An ether group, an ester group, an ester group, an ester group, an ester group, an amine group, and an imine group, preferably a methylene group, an ethylene group, an ethene-diyl group, an ethyne-diyl group, a fluoromethylene group, An amine group, and an imine group.

More specifically, the azo-based compound may be a compound having a structure represented by the following general formulas (2a) to (2d):

(2a)

(Wherein n is an integer of 1 to 20)

- Aromatics: 4

- Molecular weight of the rigid-core part: 420 g / mol

- Total molecular weight of the compound: 482 to 982 g / mol (depending on the value of n)

Solubility in liquid crystal host: 0.1 to 1.0 wt%

(2b)

(Wherein n is an integer of 1 to 20)

- Aromatics: 4

- Molecular weight of the rigid-core part: 332 g / mol

- Total molecular weight of the compound: 394 to 894 g / mol (depending on the value of n)

Solubility in liquid crystal host: 0.1 to 2 wt%

[Chemical Formula 2c]

(Wherein n is an integer of 1 to 20)

- Aromatics: 4

- Molecular weight of the rigid-core part: 384 g / mol

- Total molecular weight of compound: 446 to 946 g / mol (depending on n value)

Solubility in liquid crystal host: 0.1 to 2.0 wt%

(2d)

(Wherein n is an integer of 1 to 20)

- Aromatics: 4

- Molecular weight of the rigid-core part: 360 g / mol

- Compound total molecular weight: 422 to 922 g / mol (depending on n value)

Solubility in liquid crystal host: 0.1 to 3.0 wt%

When the liquid crystal layer is formed by mixing the pretilt angle stabilizer of the liquid crystal of the azo type with the liquid crystal and then the light irradiation is performed, specifically, the trans-to- cis isomerization), it is possible to induce the vertical alignment of the liquid crystal.

At this time, the wavelength of light enabling photoisomerization of the liquid crystal precursor square stabilizer varies depending on the structure of the added compound. In the present invention, light having a wavelength of 200 nm to 800 nm, preferably 300 nm to 800 nm, .

The irradiation light need not necessarily be linearly polarized light, but may be non-polarized light, circularly polarized light, elliptically polarized light, or linearly polarized light incident perpendicularly to the substrate surface. In addition, It is also possible to irradiate incident light inclined with respect to the surface of the substrate.

Appropriate intensity of light, irradiation time and temperature for the induction of vertical orientation of the liquid crystal are determined by the chemical structure and concentration of the liquid crystal precursor compound to be added, the solubility to the liquid crystal host, and the dipole moment induced by the cis- It depends on the magnitude of the moment. Concretely, it is possible to induce vertical alignment of liquid crystal when light irradiation is performed at a concentration of 0.5 wt% at an intensity of several 500 mW / cm ² to several tens of W / cm ² for 10 minutes to 2 hours. However, the effective light irradiation time may vary depending on the kind, concentration, and intensity of the pretilt angle stabilizer of the liquid crystal, so that the range is not limited to the above range.

The light irradiation may be performed under the condition that the liquid crystal layer positioned between the two substrates exhibits a liquid crystal phase or an isotropic phase, and may be performed sequentially as in the first order isotropic phase and the second liquid crystal phase as described below.

The vertical orientation of the liquid crystal derived as described above is very stable for heat, light, and chemical treatments, and therefore is useful for devices that are not affected by them and require maintenance of a stable alignment state. For example, the vertical orientation of the liquid crystal derived as described above was stably maintained even after heat treatment at 120 ° C for 3 days or irradiation of strong visible light for 5 hours. In addition, the liquid crystal host was maintained in the orientation power even after treatment with a common organic solvent such as chloroform, dichloromethane, hexane, or toluene.

In yet another more preferred embodiment, the linear quadrangle stabilizer of the liquid crystal may comprise a diazo- or triazo-

(3)

Wherein R, R _1, R _2, Ra, Rc, Rd, Re, l, p, q, n, x and y are the same as defined above,

X ₁₂ and Y ₁₂ are both an azo group (-N═N-), or one of them is an azo group and the other is an alkylene group (for example, a methylene group or an ethylene group) having 1 to 20 carbon atoms, An alkyne-diyl group having 2 to 20 carbon atoms (e.g., an ethyne-diyl group and the like), an alkyne-diyl group having a carbon number of 2 to 20 (For example, a fluoromethylene group, a fluoroethylene group, etc.), an ether group, an ester group, an amine group, and an imine group.

The diazo compound may more specifically be a compound of the following formula (3a): < EMI ID =

[Chemical Formula 3]

In the above formula, R ₁ and R ₂ are each independently an alkyl group having 1 to 20 carbon atoms.

- Aromatics: 4

- Molecular weight of the rigid-core part: 376 g / mol

- Total molecular weight of the compound: 438 to 938 g / mol (depending on the value of n)

Solubility in liquid crystal host: 0.1 to 3.0 wt%

More specifically, the triazo-based compound may be a compound of the following formula 3b:

(3b)

In the above formula, R ₁ and R ₂ are each independently an alkyl group having 1 to 20 carbon atoms.

- Aromatics: 4

- Molecular weight of the rigid-core part: 388 g / mol

- Total molecular weight of compound: 450 to 950 g / mol (depending on n value)

Solubility in liquid crystal host: 0.1 to 2.0 wt%

As another more preferred example, the linear quadrangle stabilizer of the liquid crystal may be an azoxazine clock compound of the following formula:

[Chemical Formula 4]

Wherein R, R _1, R _2, Ra, Rc, Rd, Re, l, p, q, n, x and y are the same as defined above,

X ₁₁ and Y ₁₁ each independently represent an alkylene group having 1 to 20 carbon atoms, an alkene-diyl group having 2 to 20 carbon atoms, an alkyne-diyl group having 2 to 20 carbon atoms, a fluoroalkylene group having 1 to 20 carbon atoms, An ether group, an ester group, an ester group, an ester group, an ester group, an amine group, and an imine group, preferably a methylene group, an ethylene group, an ethene-diyl group, an ethyne-diyl group, a fluoromethylene group, An amine group, and an imine group.

The azoxazine clock compound may more specifically be a compound of formula 4a or 4b:

[Chemical Formula 4a]

(Wherein n is an integer of 1 to 20)

- Aromatics: 4

- Molecular weight of the rigid-core part: 436 g / mol

- Compound total molecular weight: 498 to 998 g / mol (depending on n value)

Solubility in liquid crystal host: 0.1 to 1.5 wt%

(4b)

(Wherein n is an integer of 1 to 20)

- Aromatics: 4

- Molecular weight of the rigid-core part: 348 g / mol

- Total molecular weight of the compound: 410 to 910 g / mol (depending on the value of n)

Solubility in liquid crystal host: 0.1 to 2.0 wt%

In yet another more preferred embodiment, the linear quadrangle stabilizer of the liquid crystal may comprise an immune (Schiff base) compound of formula 5:

[Chemical Formula 5]

Wherein R, A, B, R _1, R _2, Ra to Re, a to c, 1 to n, p, q, x and y are the same as defined above,

X ₁₃ and Y ₁₃ are both an imine group (-CH = N-), or one of them is an imine group and the other is an alkylene group having 1 to 20 carbon atoms (e.g., a methylene group or an ethylene group) An alkyne-diyl group having 2 to 20 carbon atoms (e.g., an ethyne-diyl group and the like), an alkyne-diyl group having a carbon number of 2 to 20 (For example, a fluoromethylene group, a fluoroethylene group, etc.), an ether group, an ester group, an amine group, and an azo group.

The imine compound may be more specifically selected from the group consisting of compounds represented by the following formulas (5a) to (5b):

[Chemical Formula 5a]

Wherein R ₁ and R ₂ are each independently an alkyl group having 1 to 20 carbon atoms, and X ₁₃ and Y ₁₃ are the same as defined above.

[Chemical Formula 5b]

(Wherein n is an integer of 1 to 20)

- Aromatics: 4

- Molecular weight of the rigid-core part: 418 g / mol

- Total molecular weight of the compound: 480 to 980 g / mol (depending on the value of n)

Solubility in liquid crystal host: 0.1 to 1.5 wt%

When the compound for linear quadrangle stabilizer of liquid crystal according to the present invention further contains a chiral group in the molecule, specifically, the flexible group connected to the core portion of the linear quadrangle stabilizer of the liquid crystal may be a hydrocarbon group containing a chiral group, More specifically, the chiral group may be a cholesteryl group. When the flexible group connected to the core of the compound for linear quadrangle stabilizer of the liquid crystal is a hydrocarbon group containing a chiral group, it is preferable that the number of cyclic functional groups constituting the core-rigid portion is two or more.

For example, when the chiral group is a cholesterol group, the linear quadratic stabilizer of the liquid crystal may be a chiral azo group compound represented by the following Formula 6:

[Chemical Formula 6]

In this formula,

R is the same as defined above as a flexible group, preferably an alkyl group having 1 to 20 carbon atoms,

X ₁₄ and Y ₁₄ each independently represent a single bond, an alkenyl-diyl group having 2 to 20 carbon atoms, an alkynyl-diyl group having 2 to 20 carbon atoms, a carbonyl group, an ether group, a thioether group, an ester group, a thioester group, An ethoxy group, an ester group, an amine group, an imino group, and an azo group, and is preferably selected from the group consisting of an amino group, an amino group, an amino group, And

Wherein n is an integer of 1 to 20;

In another embodiment, in Formula 6, X ₁₄ = O, Y ₁₄ = - (OC) O-, R = -CH ₂ CH ₃ and n = 10 have the following characteristics:

- aromatic and cyclic alkyl groups: 2 + 4 = 6

- Molecular weight of the rigid-core part: 406 g / mol

Compound Total molecular weight: 792 g / mol

Solubility in liquid crystal host: 0.1 to 3 wt%

When the liquid crystal preliminary square stabilizer as described above is injected into a liquid crystal cell which has not been subjected to the preliminary incompression treatment and light contained in the liquid crystal preliminary square stabilizer is irradiated with the light corresponding to the absorption wavelength of the polymerizer, The stabilizer is isomerized to a cis isomer by absorption of light in a stable trans-isomer state. At this time, there is a strong dipole-dipole interaction between the cis isomer molecules due to the physical changes occurring in the liquid crystal precursor square stabilizer, that is, the greatly improved dipole moment. As a result, the cis isomer molecules aggregate to form aggregates, and the fine aggregates formed are attached to the surface of the substrate to convert the liquid crystal alignment state of the surface from the initial random horizontal alignment state to the uniform vertical alignment state, Control becomes possible. At this time, the structure and the arrangement state of the fine aggregate formed on the substrate surface vary depending on the condition of irradiating the light, so that various types of liquid crystal alignment control can be performed. This is because the transition of the liquid crystal alignment state induced by the anisotropic arrangement of the dye molecules attributable to the trans-cis light of the azo compound existing in the surface monolayer of the conventional polymer or monomolecular azo compound compound film or the strong dichroic absorption The temperature of the liquid crystal alignment induced by such a different mechanism and the stability to light are also greatly changed. Since the change in the liquid crystal alignment due to the trans-cis light property of the azo compound present in the surface monolayer of the conventional polymer or monomolecular azo compound compound film is reversibly converted by irradiation and heating of light having a different wavelength, And the stability of orientation to temperature is greatly reduced. Further, the transition of the liquid crystal alignment state induced by the anisotropic arrangement of dye molecules due to dichroic absorption is a technique for controlling uniform horizontal alignment of liquid crystal using a strong linearly polarized light laser, The results of the mechanism and orientation are different from the present invention.

In the present invention, not only the insoluble micro molecular aggregate formation of the cis isomer induces a new orientation but also the insoluble micro aggregates form a solid solid film on the surface of the substrate, thereby forming a highly stable alignment film which is not changed by heat and light .

In addition, the present invention provides a method of inducing vertical alignment of a liquid crystal by a linear stabilizer of the liquid crystal and forming a stabilized square of the liquid crystal.

In addition, the alignment state of the liquid crystal obtained regardless of the polarization state of the irradiated light shows a vertical orientation in which the long axis of the liquid crystal molecule is oriented perpendicularly to the substrate surface, which is different from the conventional horizontal orientation technique using linearly polarized light. Further, since the orientation of the liquid crystal exhibits a very stable orientation state that is not changed with respect to heat and light, it is useful for a device that requires permanent alignment stability, not a device that reverses the orientation by light.

Accordingly, it is possible to manufacture a liquid crystal device having excellent performance and reliability by forming a passivation layer on the electrode layer by inducing and stabilizing the pretilt angles of the liquid crystal without using the linear alignment treatment process using the liquid crystal precursor square stabilizer according to the present invention.

According to another embodiment of the present invention, there is provided a composition for forming a liquid crystal layer, which comprises the liquid crystal precursor of a precursor square.

Specifically, the composition for forming a liquid crystal layer includes a linear stabilizer of the above-mentioned liquid crystal together with a liquid crystal host.

The liquid crystal host can be used without any particular limitation as long as it is usually used in a liquid crystal display device. Specifically, a nematic liquid crystal having negative dielectric anisotropy or a liquid crystal mixture having positive dielectric anisotropy can be used.

The linear stabilizer of the liquid crystal is the same as that described above.

The pretilt angle stabilizer of the liquid crystal may be included in an amount of 0.05 to 2% by weight based on the total weight of the composition for forming a liquid crystal layer. When the content of the linear stabilizer of the liquid crystal is out of the above range and less than 0.05% by weight, the effect of the pretilt angle induction and surface stabilization on the liquid crystal host is insignificant. When the content exceeds 2% by weight, The performance of the liquid crystal display element may deteriorate due to occurrence of photostabilization. More preferably from 0.1 to 1.5% by weight.

FIG. 2 is a process diagram schematically illustrating a manufacturing process of a liquid crystal display device according to an embodiment of the present invention using the above-described liquid crystal pretilt angle stabilizer. 2 is only one example for explaining the present invention, but the present invention is not limited thereto.

Hereinafter, each step will be described in detail with reference to FIG.

Step 1 is a step of forming the electrodes 12 and 22 on the first substrate 11 and the second substrate 21, respectively (S11).

The first and second substrates can be used without particular limitation as long as they are used in liquid crystal display devices. Specifically, glass or plastic substrates can be used. In addition, the substrate does not require the formation of an orientation film or orientation treatment process for inducing the vertical orientation of the liquid crystal, and the inner surface of the substrate in contact with the liquid crystal layer is formed of a conductive film, an insulating film, an organic material layer, an organic material layer, It is possible to use.

A common electrode (or a transparent electrode) is formed as a first electrode 12 on one surface of the first substrate 11 and a pixel electrode is formed as a second electrode 22 on a surface of the second substrate 21 . In this case, the first substrate and the second substrate, and the common electrode and the pixel electrode are classified according to their positions and functions, and a common electrode may be formed on the second substrate, or a pixel electrode may be formed on the first substrate.

The first and second electrodes 12 and 22 may be manufactured according to a conventional method of forming an electrode and the first and second electrode forming materials may be typically used for forming electrodes of a liquid crystal display element, Can be used without.

Specifically, the first and second electrodes 12 and 22 may include a material selected from the group consisting of a metal oxide, a carbon-based electroconductive material, and a mixture thereof. Preferably, indium tin oxide (ITO), zinc oxide (ZO), indium zinc oxide (IZO), tin oxide (TO), indium oxide (ITO) IO), aluminum oxide (Al ₂ O ₃ , AO), silver oxide (AgO), titanium oxide (TiO ₂ ), fluorine-doped tin oxide (FTO), aluminum doped zinc zinc oxide (AZO), zinc indium tin oxide (ZITO), nickel oxide (NiO), nickel zinc tin oxide (NZTO), nickel titanium oxide (NTO) , Nickel tin oxide, graphene, graphene oxide (GO), and mixtures thereof. ≪ RTI ID = 0.0 >

The first and second electrodes 12 and 22 may be formed over the entire surface of the substrate or may be patterned (not shown) in a predetermined shape such as an island, a sprite, or a fishbone through a separate patterning process It is possible. Accordingly, according to another embodiment of the present invention, at least one of the first and second electrodes 12 and 22 is patterned.

At least any one of the first and second substrates 11 and 21 may be formed on at least one of the first and second electrodes 12 and 22 after the electrode formation, A step of forming an electrically insulating compound layer (not shown) may be further performed on the electrode forming step or both of the electrode forming step and the electrode forming step.

As a result of the above process, an electrically insulating compound layer serving as a passivation layer or an insulating layer may be formed on the upper portion or the lower portion of the electrodes 12 and 22. Also, An electrically insulating compound layer may be formed on both the top and bottom of the electrode. According to another embodiment of the present invention, there is provided a liquid crystal display device having an electric insulating compound layer formed on at least one of the first and second electrodes 12 and 22, do.

The electrically insulating compound layer may include an organic insulating material, a nonmetal oxide, or a nonmetal nitride. Specifically, the electrically insulating compound layer may be a single film composed of silicon oxide (SiOx) or silicon nitride (SiNx), or a bilayer or multilayer structure composed of a silicon oxide film and a silicon nitride film.

Alternatively, water may be selectively applied to the substrate (11 or 21) on which the electrode (12 or 22) is formed. Organic solvents such as acetone and isopropyl alcohol; ozone; Or a process of washing impurities and water on the surface of the electrode by washing with a plasma or the like.

In addition, the manufacturing method according to the present invention may further include an orientation film formation step in which a vertical orientation or a horizontal alignment process is performed after the electrode formation step.

In step 2, the first substrate and the second substrate 11, 21 each including the first and second electrodes 12, 22 are bonded to each other with the electrodes facing each other, and then the first substrate and the second substrate 11, A composition for forming a liquid crystal layer is injected into a space or a composition for forming a liquid crystal layer is dropped onto any one of a first substrate and a second substrate including the first and second electrodes 11 and 21 under vacuum After the liquid crystal layer 13a is formed, the remaining substrates are bonded to each other so that the electrodes face each other (S12).

The liquid crystal layer-forming composition is the same as that described above.

The step of bonding the first substrate and the second substrate and the step of injecting or dropping the composition for forming a liquid crystal layer can be carried out according to a conventional method.

When the composition for forming a liquid crystal layer is injected into a cell prepared by using a substrate not subjected to a linear alignment treatment, the initial alignment state of the cell after the liquid crystal injection shows a random horizontal alignment characteristic due to the surface property of the substrate not subjected to the alignment treatment See the liquid crystal layer 13a in S12 of Fig. 2).

After the injection of the composition for forming a liquid crystal layer, the assembly is heated at a temperature 1 to 20 DEG C higher than the nematic-isotropic phase transition temperature of the mixture of the liquid crystal host and the liquid crystal precursor square stabilizer, A homogenization process may optionally be further carried out.

Step 3 is a step of inducing a preliminary square of the liquid crystal by light irradiation on the assembly manufactured in Step 2 above.

The linearly guiding of the liquid crystal can be performed by various methods as described below. The vertical direction inducing step S13 for guiding the liquid crystal, , Or a method of directly inducing a pretilt angle to an assembly manufactured in the step 2 without a vertical orientation induction step for the liquid crystal.

Upon irradiation of light for linear guide of the liquid crystal, light of a wavelength enabling trans-cis isomerization of the added liquid crystal precursor square stabilizer compound is irradiated. At this time, the wavelength of light enabling the photo-isomerization varies depending on the structure of the added compound. Generally, since the light appears in the range of 200 nm to 800 nm, the present invention can irradiate light having a wavelength of 300 nm to 800 nm. At this time, since the light to be irradiated does not necessarily have to be linearly polarized light, unpolarized light, circularly polarized light, elliptically polarized light, and linearly polarized light incident perpendicularly to the substrate surface can be used respectively.

Appropriate light intensity, irradiation time, and temperature for liquid crystal vertical orientation and linear orientation induce the chemical structure and concentration of the added liquid crystal precursor square stabilizer, solubility in liquid crystal host, and cis-isomerization The linear quadrangle stabilizer of the liquid crystal according to the present invention is characterized by a light irradiation of 1 minute to 2 hours at a concentration of 0.05 to 2% by weight and an intensity of several mW / cm ² to several tens of W / cm ² It is possible to induce the vertical alignment and to stabilize the pretilt angle. However, since the effective light irradiation time may vary depending on the concentration of the linear stabilizer of the liquid crystal and the intensity of the light, it is not limited to the above range.

The light irradiation may be performed under the condition that the liquid crystal layer located between the two substrates exhibits a liquid crystal phase or an isotropic phase, and may be sequentially performed as described above on the first order isotropic phase and the second liquid crystal phase .

When the liquid crystal cell is irradiated with light under the above-described conditions, the added light absorbs the light and is isomerized to the cis-isomer, so that the concentration of the cis-isomer increases and the symmetry of the cis- As a result, the dipole moment greatly increases, and insoluble solid fine aggregates are generated by strong dipole-dipole interactions between these cis-isomers. These fine aggregates are adsorbed on the surface of the substrate to form a liquid crystal precursor square inductive layer 14, 24 as a solid solid film, leading to the formation of a square of the liquid crystal. At this time, when the irradiation light is incident perpendicularly to the substrate surface, the liquid crystal is aligned perpendicular to the substrate, and a vertical alignment state in which the average director and the optical axis of the liquid crystal are aligned perpendicular to the substrate is obtained (S13 (See the liquid crystal layer 13b in Fig. However, when the incident light, which is inclined with respect to the vertical direction of the substrate surface, is irradiated, the average director and the optical axis of the liquid crystal form a square line in a direction inclined with respect to the vertical direction of the substrate surface (See 13c). The liquid crystal pre-emergence quadrangular inductive layers 14 and 24 formed by the adsorption of the fine aggregates are liquid crystal pre-emergence quadrature stabilization layers 15 and 25 for stabilizing the liquid crystal pretilt angle in the finally manufactured liquid crystal display device.

When the molecular weight of the linear stabilizer of the liquid crystal is large and the solubility to the liquid crystal host is low, it is possible to induce the vertical alignment of the liquid crystal even with a small amount of the inducer, and the orientation state of the derived liquid crystal is very It is stable and can be maintained permanently.

When the liquid crystal cell subjected to the light irradiation treatment is observed using a polarization microscope, the vertical alignment of the liquid crystal is uniformly induced and the quenched state is exhibited under the orthogonal polarizer. Also, it can be confirmed that the optical axis of the liquid crystal layer is arranged in a direction perpendicular or slightly inclined to the substrate using conoscopic. Then, by applying an electric field to the liquid crystal cell in which the vertical alignment is induced, it is possible to evaluate the electrooptical switching characteristics depending on the presence or absence of the pretilt angle.

The manufacturing method according to the present invention can also induce and stabilize the pretilt angle of the liquid crystal by performing light irradiation after manufacturing a liquid crystal device by using a substrate on which a vertically aligned or horizontally oriented alignment layer is formed. In addition, the manufacturing method according to the present invention also includes the steps of applying an electric field through the fine patterned electrode to induce a multi-patterned liquid crystal array, then stabilizing the multi-patterned pre- It is possible to stabilize the pattern of the multiple divided pretilt angles by performing the multi-stage light irradiation in the inclined direction using the photomask without using the patterned electrode. In addition, since the pretilt angle of the liquid crystal direct can be induced by the tilted light irradiation, the light irradiation is performed using the photomask in which the lens array is formed, so that the multi-domain vertically aligned prearranged square Lt; / RTI >

Specifically, the above-mentioned preliminary quadrangle formation and stabilization process may be carried out by the following five methods, and these methods may be respectively carried out or combined with each other.

1) Light irradiation using oblique incident light

It is possible to induce the angle of incidence of the liquid crystal direct in a specific direction by making the incidence direction of the light to be irradiated at the time of light irradiation be inclined at an angle of less than 90 degrees with respect to the substrate surface of the liquid crystal cell.

FIG. 3 is a conceptual diagram of forming a pre-scan square by guiding the oblique light. The direction perpendicular to the surface a substrate in FIG. 3, b is that the irradiation light incident direction, c is the orientation of the liquid crystal director, θ ₁ is angle (the oblique incident angle) if a and b forms and θ ₂ is a and c (Liquid crystal pretilt angle), respectively.

Referring to FIG. 3, when the light is irradiated with the oblique incident light, the direction of the liquid crystal pretilt angle is in a plane defined by the incident light irradiated as shown in FIG. 3 and the vertical line of the substrate surface. θ ₁₎ and the liquid crystal pretilt angle (θ ₂₎ it is not always consistent. The polarization state of the irradiation light used at this time does not necessarily have to be linearly polarized light but can be used irrespective of the polarization state such as unpolarized light, circularly polarized light, and elliptically polarized light. Also, in the case of forming a square of the liquid crystal using such a method, it is possible to form multi domains in which the linear axes of the liquid crystals are different from each other by performing multistage light irradiation that is tilted in a specific direction for each domain by using a photomask . Examples that can be produced using this method are shown in FIGS. 4A and 4B.

FIGS. 4A and 4B show examples of four domains in which pixels are divided into quadrants. In FIG. 4, 31 denotes a pixel, 32 denotes a liquid crystal tilt domain, and arrow denotes a direction in which the liquid crystal direct is inclined in the tilt domain.

Further, in order to induce a more efficient vertical alignment and to form a square of the liquid crystal, the vertical alignment of the liquid crystal is induced by the light treatment using the first-order vertical incident light, and then the incident direction of the second- The light processing may be performed in two or more steps of forming a square of the liquid crystal by performing light treatment using oblique incident light inclined at an angle of less than 1 mm. Therefore, when a pixel is divided into multiple parts to form a square of the liquid crystal to improve the viewing angle of the device, multilevel tilted light irradiation is performed using a photomask without a fine pattern of the electrode, which is very useful . In addition, it is possible to improve the characteristics such as the reaction speed, the luminance, and the driving voltage of the device by suppressing the occurrence of defects in the switching of the liquid crystal device by securing the stability of the alignment due to the formation of the square-

At this time, various types of lenses can be used for the linear guidance of the liquid crystal by the light irradiation using the 1) oblique incident light. Figures 5 and 6 are diagrammatic representations of some examples of applicable lenses. FIGS. 5A to 5C show the progress path of the irradiation light when the circular convex lens 1 is placed on the liquid crystal cell as a mask and incident light perpendicular to the substrate surface of the cell is irradiated. 6A to 6C show the progress path of the irradiated light when the circular concave lens 1 is placed on the liquid crystal cell as a mask and the incident light perpendicular to the substrate surface of the cell is irradiated. As can be seen from Figs. 5A to 5C and 6A to 6C, the irradiation light is regularly refracted by the lens located above the cell, and the light incident on the liquid crystal cell advances in an oblique direction to the substrate surface. In the case of the convex lens, incident light is converged in the region (a) and incident light is emitted in the region (b). However, in the case of the concave lens, it can be seen that the incident light always diverges. Therefore, when the light irradiation is performed under these conditions, the liquid crystal alignment is inclined in a plane formed by the inclined direction of the light incident on the liquid crystal cell and the central axis of the lens in the area corresponding to the cross sectional area of the lens.

FIGS. 7A and 7B are diagrams showing the square-line direction of the liquid crystal when the concave lens of FIG. 6 is applied or the convex lens of FIG. 5 is used and the liquid crystal cell is placed in the region (B) , And arrows indicate directions in which the liquid crystal direct is inclined. The inclination of the liquid crystal molecules observed in the vertical section direction of the lens (FIG. 7A) and the vertical direction of the substrate surface (FIG. 7B) is gradually increased toward the edge from the central axis of the lens toward the edge .

Figs. 8A and 8B are diagrams showing the direction of the square of the liquid crystal in the case where the convex lens of Fig. 5 is used and the liquid crystal cell is placed in the region (A) and light irradiation is performed. The inclination of the liquid crystal molecules in the vertical axis direction of the lens (FIG. 8A) and the inclined direction of the liquid crystal molecules observed in the vertical direction of the substrate surface (FIG. 8B) And it gradually increases in the opposite direction. This is because the angle of the light emitted or converged by the lens changes depending on the position, which can be controlled by controlling the characteristics of the lens.

5A to 8B, the pre-scan square control of a liquid crystal using a lens is performed by applying various types of lenses such as a cylindrical lens and a square lens in addition to a spherical lens to irradiate the liquid crystal cell in a specific pattern It can be changed.

In addition, the above-described technique is useful for producing a multi-domain device in which a lens is formed into an array shape and applied as a photomask, and light irradiation is performed once to induce vertical alignment and patterned with a square pixel on a pixel basis. 4A and 4B), and the pixel division of the octuple domain or the infinite domain is very useful because it can be realized by one light irradiation by applying a lens array of a specific design. In this case, there is an advantage in that the process is very simple and efficient as compared with the fine patterning of the electrodes or the multi-light irradiation technique which are used in the prior art for wide viewing angle of the device.

Further, in the case of forming a pattern of a square-circle by using a lens, light irradiation may be carried out twice. The preliminary alignment of the liquid crystal may be induced first by irradiating light without a lens mask, and then a secondary light irradiation may be performed by applying a lens mask to form a preliminary angle.

2) Light irradiation under an electric field

The vertical orientation of the liquid crystal is induced by the first light irradiation in the vertical direction of the substrate and then the electric field is applied to the assembly in the vertical alignment state of the liquid crystal before the addition of the preliminary square stabilizer of the liquid crystal is consumed, The alignment of the liquid crystal director can be induced and then the secondary light irradiation can be performed to simultaneously achieve the vertical alignment of the liquid crystal and the square-angle induction in a specific direction.

In this case, the application of the electric field and the irradiation of the second light are preferably performed in a temperature range in which the liquid crystal is not isotropic but in a liquid crystal phase, and the intensity of the applied voltage can be changed in various stages during light irradiation. Under such a process, the micro molecular aggregate generated by the light-induced crystallization first adheres to the surface of the substrate to induce the vertical alignment. Secondly, the microcrystallization is not formed in the first step, The quadratic stabilizer forms a fine aggregate in a specific alignment state of the host liquid crystal by the secondary light irradiation and adheres to the surface of the substrate in a state in which the liquid crystal director is inclined in a specific direction to form a square of the liquid crystal at the surface.

The light used for the secondary light irradiation is not particularly limited. Specifically, it is preferable that the direction of incidence on the substrate surface is perpendicular to the substrate surface, or that the direction of incidence of light is less than 90 degrees with respect to the substrate surface It may be an oblique incidence light.

In addition, when the conductive film of one substrate or both substrates is patterned into multiple domains for switching the wide viewing angle of the liquid crystal, a state in which the direction of the square of the liquid crystal is patterned into multiple domains can be derived. Therefore, the present invention can be applied to a liquid crystal device such as a vertically aligned liquid crystal (VALC-mode) in which a vertical alignment and a pre-alignment angle are simultaneously required. In particular, the present invention can be advantageously used for manufacturing a liquid crystal device for a wide viewing angle using a multi-domain division of a liquid crystal frontal quadrangle in a pixel. In addition, it is possible to improve the characteristics such as the reaction speed, the luminance, and the driving voltage of the device by suppressing the occurrence of defects in the switching of the liquid crystal device by securing the stability of the alignment due to the formation of the square-

3) When the vertical alignment film and the light processing using the oblique incident light are performed concurrently

A liquid crystal cell is fabricated using a vertically aligned substrate on which a pre-alignment angle is not formed, and a direction in which the direction of incidence of light is less than 90 degrees with respect to the substrate surface in order to induce a pre- By irradiating incident light, it is possible to induce a pretilt angle of the liquid crystal. At this time, the inclination angle may vary depending on the inclination of the incident light, the concentration of the linear stabilizer of the liquid crystal, and the light irradiation time.

At this time, the direction of the pretilt angle exists in a plane formed by the incident light to be irradiated and the vertical line of the substrate surface (see FIG. 3), and the tilted angle of the irradiated light and the liquid crystal pretilt angle do not always coincide with each other. The polarization state of the irradiation light used at this time is not necessarily linearly polarized. In the case of forming the pretilt angle of the liquid crystal by using this method, it is possible to form multi domains in which the linear angles of the liquid crystals are different from each other by performing multistage light irradiation that is tilted in a specific direction for each domain by using a photomask. Therefore, when a pixel is divided into multiple parts to form a square of the liquid crystal to improve the viewing angle of the device, multilevel tilted light irradiation is performed using a photomask without a fine pattern of the electrode, which is very useful . This method is similar to the light irradiation method using the above-mentioned 1) oblique incident light, but it does not induce the vertical alignment of the liquid crystal by the light irradiation but induces the vertical alignment by the formation of the vertical alignment film, and the light irradiation using the oblique incident light But it is only involved in the process of forming the pre-scan square of the liquid crystal direct.

In addition, it is possible to improve the characteristics such as the reaction speed, the luminance, and the driving voltage of the device by suppressing the occurrence of defects in the switching of the liquid crystal device by securing the stability of the alignment due to the formation of the square-

4) In the case of parallel processing of vertical alignment film with electric field application

A liquid crystal cell is fabricated using a vertically aligned substrate having no linearly arranged square and a liquid crystal having a negative dielectric constant anisotropy and light irradiation is performed under the application of a vertical electric field to induce the linear polarization of the liquid crystal. When an electric field in a direction perpendicular to the substrate surface is applied to the manufactured liquid crystal cell, the liquid crystal molecules are tilted toward the substrate surface due to negative dielectric anisotropy of the liquid crystal. When the light is irradiated in such a state that an electric field capable of maintaining a state in which the liquid crystal direct is inclined in a specific direction is applied, the pretilt angle of the liquid crystal can be induced in a specific direction. At this time, the light used for light irradiation may be light perpendicular to the surface of the substrate or inclined toward the liquid crystal director at an arbitrary angle within a plane defined by the liquid crystal direct and a direction perpendicular to the substrate surface. In this case, when the incident direction of the light used for the light treatment is perpendicular to the substrate surface, the application of the electric field and the light treatment are preferably performed at a temperature at which the host liquid crystal exhibits the liquid crystal phase. In addition, an un-patterned electrode layer may be used to apply an electric field in a direction perpendicular to the substrate surface, or a patterned electrode may be used on at least one substrate among the upper and lower substrates. This case is similar to the light irradiation method under the application of the electric field 2) described above, but the vertical orientation is induced by the coating of the vertical alignment film, not by inducing the vertical alignment by the primary light irradiation, But it contributes only to the process of forming the pre-curved rectangle.

In this case, the pixel unit multi-division of the square of the liquid crystal pretilt angle for improving the viewing angle of the device is basically induced by the fine pattern of the electrode, and can be stabilized permanently through the one-step light irradiation. Therefore, there is an advantage in that a pattern of a multi-divided pre-scan square can be achieved without using a photomask. In addition, it is possible to improve the characteristics such as the reaction speed, the luminance, and the driving voltage of the device by suppressing the occurrence of defects in the switching of the liquid crystal device by securing the stability of the alignment due to the formation of the square-

5) Concurrent with the rubbed horizontal alignment film and light treatment

It is also possible to use a substrate having a horizontal alignment film rubbed as the first and second substrates to form a pre-scan square of liquid crystal. When the liquid crystal cell is manufactured using the rubbed horizontal alignment film, liquid crystal molecules exhibit uniform horizontal alignment at the initial stage after the liquid crystal layer forming composition containing the liquid crystal precursor square stabilizer compound is injected. However, when the liquid crystal cell is irradiated with light according to the above-described vertical orientation inducing method, the liquid crystal director may induce a skewed angle that is inclined in the rubbing direction with respect to the vertical direction of the substrate.

At this time, the degree of the pretilt angle can be controlled according to the concentration, light intensity and time of the orientation inducing agent used for the liquid crystal host. As the amount of the fine molecular aggregate adsorbed on the substrate surface increases in the initial homogeneous horizontal alignment state formed by the rubbing, the liquid crystal directors have a larger diameter and become a vertically aligned state. In this process, when the pretilt angle changes, the alignment component on the substrate surface of the liquid crystal direct always coincides with the initial rubbing direction, so that the azimuth of the liquid crystal direct at a specific pretilt angle can be controlled by the initial rubbing direction. In this case, light whose direction of incidence of light used for the light processing is perpendicular to the substrate surface may be used, or light which inclines in a rubbing direction of the horizontal alignment film in a direction perpendicular to the substrate surface may be used. In addition, when the light irradiation is performed in the state that the electric field is applied, there is an advantage that the liquid crystal pretilt angle can be changed according to the intensity of the voltage applied at the time of light irradiation.

The evaluation of the alignment stability of the liquid crystal derived by the above method can evaluate the stability of the vertical alignment induced by heating the liquid crystal cell after the vertical alignment is induced by light irradiation. At this time, the vertical alignment stability of the liquid crystal induced by heating at a temperature 10 ° C higher than the isotropic phase transition temperature of the liquid crystal layer forming composition used for a long time is evaluated. Alternatively, after the vertical orientation is induced by light irradiation, the white light having a wavelength necessary for cis-to-trans isomerization of the white light (320 to 900 nm wavelength) or the linear quadrangle stabilizer of the liquid crystal used The stability of the orientation depending on the irradiation time and the irradiation intensity can be evaluated while irradiating the light.

According to the method for manufacturing a liquid crystal display of the present invention as described above, it is possible to prevent the occurrence of defects of the liquid crystal which occurs during driving the device and improve the reaction speed, thereby improving the performance and reliability of the device. Especially, it is possible to improve the viewing angle characteristics, luminance, contrast ratio, reaction speed, and optical / electro-optical characteristics of the liquid crystal device because the liquid crystal device can squarely guide the surface liquid crystal and stabilize the director. In addition, since the process is performed at room temperature, the process temperature is significantly lower than the firing temperature of the conventional polymer alignment film, and the process is simple. Particularly, a high-quality liquid crystal display device or a flexible substrate ). ≪ / RTI >

The liquid crystal display device can be replaced with a conventional high temperature alignment film coating and firing process at a room temperature process. Therefore, not only a high-quality liquid crystal display element using a glass substrate but also an alignment film baking step at a high temperature is omitted, which is useful for manufacturing a display element which is difficult to perform at high temperature such as a flexible liquid crystal display element.

The liquid crystal display device according to the present invention manufactured by such a manufacturing method can be variously applied to an electro-optical device product using a liquid crystal such as a TV, a 3D-TV, a monitor, a tablet PC, various mobile devices, and particularly, a flat panel display.

According to another embodiment of the present invention, there is provided a liquid crystal display device manufactured by the above manufacturing method.

Specifically, a liquid crystal display according to an embodiment of the present invention includes a first substrate and a second substrate facing each other; A first electrode and a second electrode respectively formed on mutually facing surfaces of the first substrate and the second substrate; And a liquid crystal layer interposed between the first substrate and the second substrate, wherein the liquid crystal layer is made of a composition for forming a liquid crystal layer including a liquid crystal host and a liquid crystal precursor stabilizing agent, And liquid crystal precursor square stabilizing films (15, 25) comprising a micromolecular assembly by cis-isomerization of a precursor square stabilizer of liquid crystal on each surface in contact with the substrate and the second substrate.

The liquid crystal display of the present invention including the liquid crystal layer as described above can be manufactured by using a liquid crystal having a vertical orientation of the liquid crystal alignment and a liquid crystal having negative or positive dielectric anisotropy in a state in which no electric field is applied, It is useful for liquid crystal mode. A preferred example is a liquid crystal device (Vertically Aligned Liquid Crystal Mode, VA LC-mode) in which a liquid crystal having a negative dielectric anisotropy is controlled by applying a vertical electric field in an initial vertical alignment state.

According to another embodiment of the present invention, there is provided a liquid crystal pregelatinized square stabilizer useful for linearly guiding and stabilizing liquid crystals, and a method of precursory rectangle induction of liquid crystal using the same.

The pretilt angle stabilizer of the liquid crystal is the same as described above.

In addition, the method of inducing the pretilt angle of the liquid crystal may be conducted by irradiating light to a composition for forming a liquid crystal layer including a linear stabilizer of a liquid crystal and a liquid crystal host. Details of the light irradiation method are the same as those described above.

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

Comparative Example 1-1

A liquid crystal display device was fabricated according to the manufacturing process of the liquid crystal display device shown in FIG. 2 by using two substrates on which un-patterned transparent electrodes (ITO) were formed as first and second substrates.

2, the first and second substrates 11 and 21 are cleaned by ultrasonic cleaning in distilled water using a detergent, and then washed with acetone and isopropyl alcohol, respectively, and dried. The transparent electrodes 12 and 22 on the first and second substrates are assembled so as to oppose each other without any alignment treatment, and then, as a preliminary quadrangle stabilizer compound of the liquid crystal with respect to the total weight of the liquid crystal host having negative dielectric anisotropy, (4-hydroxy-4'-buthyl azobenzene) represented by the following formula (7) were mixed in a ratio of 1.0 wt% to prepare two uniform compositions for liquid crystal layer formation, And cooled to room temperature to prepare a liquid crystal display device. At this time, the gap between the first substrate and the second substrate was maintained at 10.0 탆, and the injection of the composition for forming the liquid crystal layer was performed at 90 캜, which is the isotropic temperature of the liquid crystal layer forming composition.

(7)

(7)

The liquid crystal precursor square stabilizer compound of formula (7) includes a rigid-core comprising a single azo group and two aromatic groups (i.e., a phenylene group) as a photo-crystallizing group and having a terminal butyl group and a hydroxyl group substituted , The molecular weight of the ligand-core portion is 180 g / mol and the total molecular weight is 254 g / mol. The linear quadrangle stabilizer of the liquid crystal does not show a liquid crystal phase, but exhibits excellent solubility exhibiting a solubility of 8 wt% or more with respect to the liquid crystal host because of its excellent affinity with the liquid crystal host liquid crystal molecules.

Comparative Example 1-2

A liquid crystal display device was fabricated in the same manner as in Comparative Example 1-1 except that 6.0 wt% of 4-hydroxy-4'-butyl azobenzene was used as the linear stabilizer compound of the liquid crystal.

The alignment states of liquid crystals in the liquid crystal display devices manufactured in Comparative Examples 1-1 and 1-2 were observed using a polarization microscope.

As a result, it was confirmed that the liquid crystal was randomly arranged in the horizontal direction with respect to the substrate in the liquid crystal cell.

Then, the alignment state of the liquid crystal layer was observed while irradiating unpolarised ultraviolet ray having a wavelength of 350 nm to 380 nm at a rate of 100 mW / cm ² in the direction perpendicular to the substrate surface.

As a result of observing the change of the alignment state of the liquid crystal layer with the irradiation time of ultraviolet rays, it was found that all the liquid crystal display devices made of the composition for forming the liquid crystal layer each containing 0.5 wt% and 6.0 wt% Orientation was not induced. In addition, the alignment state was observed up to 120 minutes at the interval of 30 minutes in the light irradiation condition, and the initial random horizontal alignment state before the light irradiation remained unchanged.

Comparative Examples 2-1 and 2-2

4,4'-dihexyloxy azobenzene (4,4'-dihexyloxy azobenzene) represented by the following formula (8) as a precursor of a liquid crystal precursor to the total weight of liquid crystal host having a negative dielectric anisotropy was added in an amount of 0.5 wt% and 6.0 wt% %, The liquid crystal display device was manufactured by the same method as in Comparative Example 1-1.

(8)

(8)

The liquid crystal precursor square stabilizer compound of formula (8) includes a rigid-core containing a single azo group as a light-modifying group and formed of two aromatic groups (i.e., a phenylene group), and a hexyloxy group As the substituted compound, the molecular weight of the rigid-core portion is 180 g / mol and the total molecular weight is 382 g / mol. In addition, the compound additive is a compound having excellent solubility in liquid crystal phase, exhibiting excellent affinity with liquid crystal host molecules and exhibiting a solubility of 6 wt% or more with respect to the liquid crystal host.

The alignment states of the liquid crystals in the liquid crystal display devices manufactured in Comparative Examples 2-1 and 2-2 were observed using a polarization microscope.

As a result, it was confirmed that the liquid crystal was randomly arranged in the horizontal direction with respect to the substrate in the liquid crystal cell.

Then, the alignment state of the liquid crystal layer was observed while irradiating unpolarised ultraviolet light having a wavelength of 350 nm to 380 nm at a rate of 10 mW / cm ² in a direction perpendicular to the substrate surface.

As a result of observing the change of the alignment state of the liquid crystal layer according to the ultraviolet irradiation time, the liquid crystal display of Comparative Example 2-1 made of the composition for forming a liquid crystal layer containing 0.5% by weight of the azo compound additive used in the experiment, And the induction of the vertical orientation was not observed even when the intensity of the irradiated nonpolarizing ultraviolet ray was increased by 300 mW / cm ² .

On the other hand, in the liquid crystal display element of Comparative Example 2-2 made of the composition for forming a liquid crystal layer containing the liquid crystal pre-crystallization square stabilizer of 6.0 wt%, the vertical alignment of the liquid crystal was induced.

Figs. 9A, 9B and 9C show the results of observing the liquid crystal alignment of the liquid crystal display device of Comparative Example 2-2 before, after and immediately after the irradiation with a polarizing microscope. The arrangement of the liquid crystal molecules observed through a conoscopic image is shown in Fig. 9D.

As shown in Figs. 9A and 9B, before the ultraviolet light was irradiated, the liquid crystal layer in the manufactured liquid crystal display element exhibited an uneven horizontally aligned state under the orthogonal polarizer, and after the ultraviolet irradiation, the completely quenched state Respectively. Also, it was confirmed that the optical axis formed by the liquid crystal layer was arranged perpendicularly to the substrate surface through the conoscopic image of FIG. 9D. However, the stability of the liquid crystal in the vertical alignment state shown in FIG. 9B is low, and when the ultraviolet light is removed after the light irradiation, the state of slowly returning to the initial random arrangement state is observed. 9C shows that the liquid crystal alignment state after 10 minutes has been removed after ultraviolet light has been removed. As shown in FIG. 9A, the liquid crystal alignment state is restored to a random horizontal alignment state.

From these experimental results, it can be seen that, in the case of the liquid crystal precursor having high solubility in the liquid crystal host, when the concentration of the added precursor square stabilizer is low, the vertical alignment of the liquid crystal is not induced, When the concentration is high, the vertical alignment of the liquid crystal is induced, but the stability of the induced vertical alignment is very low.

Comparative Example 3

The procedure of Comparative Example 1-1 was repeated except that 2.0 mass% of a compound represented by the following formula (9) was used as a precursor of a liquid crystal precursor to the total weight of a liquid crystal host having a negative dielectric anisotropy, A display device was manufactured.

(9)

(9)

The liquid crystal precursor square stabilizer compound of the above formula (9) includes a rigid-core comprising one azo group as a light-modifying group and formed by three aromatic groups (i.e., a phenylene group) and one ester group, As the siloxane-terminated compound, the molecular weight of the rigid-core portion is 300 g / mol and the total molecular weight is 502 g / mol. Further, the compound represents a liquid crystal phase, has excellent affinity with liquid crystal host molecules, and exhibits a relatively high solubility indicating a solubility of 6.0 wt% or more in the liquid crystal host.

The alignment state of the liquid crystal in the liquid crystal display device manufactured in Comparative Example 3 was observed using a polarization microscope.

As a result, it was confirmed that the liquid crystal was randomly arranged in the horizontal direction with respect to the substrate in the liquid crystal cell.

Then, the alignment state of the liquid crystal layer was observed while irradiating unpolarised ultraviolet light having a wavelength of 350 nm to 380 nm at a rate of 10 mW / cm ² in a direction perpendicular to the substrate surface.

As a result of observing the change of the alignment state of the liquid crystal layer with respect to the ultraviolet irradiation time, the vertical alignment of the liquid crystal was observed. However, when the ultraviolet rays were removed after the light irradiation, it was gradually observed to return to the initial random arrangement state. In particular, it was observed that irradiation with visible light under a polarization microscope accelerated the transition to the initial random arrangement. From these results, it can be seen that the liquid crystal precursor of formula (3) can be vertically aligned, but the stability of the induced vertical alignment of visible and visible light is low.

Example 1

The same procedure as in Comparative Example 1-1 was carried out except that 0.5 weight% of a liquid crystal precursor stabilizer compound represented by Formula 10 was used in an amount of 0.5 weight% based on the total weight of the liquid crystal host having negative dielectric anisotropy, .

(10)

(10)

 (Wherein n is 8 in the above formula)

The liquid crystal precursor square stabilizer compound of formula (10) includes a rigid-core comprising one azo group as a light-modifying group and formed by four aromatic groups (i.e., a phenylene group) and two ester groups, And the octyloxy groups are respectively substituted. The molecular weight of the rigid-core portion is 420 g / mol and the total molecular weight is 678 g / mol. In addition, the compound represents a liquid crystal phase and has a high molecular weight, a long linear symmetrical core group, and a symmetrical molecular structure, which results in a low affinity for the liquid crystal host molecules and a comparatively low solubility of 1.2 wt% Exhibit low solubility.

As a result of observing the alignment state of the liquid crystal in the above-prepared liquid crystal display device using a polarization microscope, the liquid crystal was randomly arranged in a direction parallel to the substrate in the liquid crystal cell as shown in FIG. 10A.

Next, the prepared liquid crystal display element is fixed at a temperature 2 캜 higher than the nematic-isotropic phase transition temperature of the host liquid crystal, and then about 10 캜 is applied to the liquid crystal display element in the direction a perpendicular to the substrate surface and the alignment state of the liquid crystal layer was observed while irradiating non-polarized ultraviolet ray having a wavelength of 320 to 400 nm in an inclined direction (? ₁ = 10 °) at 20 mW / cm ² intensity.

As a result, it was confirmed that the vertical alignment of the liquid crystal was induced by the light irradiation for 20 minutes as shown in FIG. 10B.

The switching behavior of the liquid crystal was observed while applying a vertical electric field (1 kHz, 5 Vpp) to the liquid crystal display element in which the vertical alignment of the liquid crystal was induced, and the results are shown in Figs. 11A to 11B.

Generally, when the vertically aligned liquid crystal layer does not form a pretilt angle in a specific direction, the direction in which the liquid crystal rotates in response to the electric field is randomly generated in accordance with the region of the liquid crystal cell. In this case, a large number of defects of the liquid crystal array are generated, and these defects are gradually removed with time and transferred to a uniform light state. At this time, the characteristics of the liquid crystal display element deteriorate due to the occurrence of defects. However, in the case of forming a pretilt angle in a specific direction, the above-described defect does not occur, and the transition from the dark state to the bright state is performed quickly.

In the case of the liquid crystal display device manufactured by applying the oblique light as described above, it was observed that the liquid crystal display device quickly transitioned to the bright state (FIG. 11A) without generating defects in the liquid crystal alignment by applying the electric field in the dark state (FIG. 10B). Figs. 11A and 11B show a microscopic polarizing microscope photograph of a light state and a polarizing photograph of a macroscopic liquid crystal cell, respectively. It was confirmed that the direction of the liquid crystal directivity in the bright state coincided with the direction of the arrow in FIGS. 10A and 10B, and the direction of this arrow was in the same plane as the inclined plane of the irradiation incident light. 3, the direction in which the liquid crystal direct is inclined is inclined in the direction (c) opposite to the direction (b) in the plane such as the direction (b) in which the incident light is inclined from the direction (a) Respectively. However, the inclination angle? ₁ of the incident light and the inclination angle? ₂ of the liquid crystal direct do not always coincide with each other. In the case of this embodiment, it was confirmed that about 2 degrees inclined to the incident angle of inclination (θ ₁₎ the rubbing direction from the vertical of about 10 resulting substrate surface done quantitatively measure the inclined lead-angle of the liquid crystal when direct degrees.

Further, in order to realize multi-domainization of the square of the pretilt angle, the composition for forming the liquid crystal layer was injected into the cell fabricated in Example 1 and multi-stage light irradiation was performed.

The non-polarized ultraviolet light having a wavelength of 320 to 400 nm in a direction perpendicular to the substrate surface of the liquid crystal display device was immersed in a solution of 20 mW / cm < 2 > ^And the vertical alignment of the liquid crystal was induced by light irradiation for 20 minutes in the ^second century. At this time. The state of liquid crystal vertical alignment on the substrate surface is simplified and shown in Fig. 12A. Subsequently, a portion of the liquid crystal cell was covered with a photomask as shown in FIG. 12B, and then light was irradiated for 10 minutes using the oblique incident light of 10 DEG as described above. As a result of evaluating the state of the liquid crystal alignment, it was confirmed that a pre-scan square was formed in the region irradiated with tilt as shown in the above example as shown in FIG. 12B. In the next step, the positions of the portions covered with the photomask were changed, and 10-degree oblique incident light was irradiated for 15 minutes in the opposite direction as shown in FIG. 12C. As a result of evaluating the state of the liquid crystal alignment, it was confirmed that a pretilt angle was formed in the opposite direction in which the pretilt angle was formed in the previous light irradiation as shown in Fig. 12C.

Similar results were obtained when the above-mentioned irradiation with oblique light was performed in different directions in two stages without conducting the above-mentioned first vertical light irradiation.

As a result, it can be seen that when the photomask is applied to obliquely irradiate multiple directions in different directions, a pattern of a multi-domain liquid crystal pretilt quadrangle can be obtained. This is very useful for providing a technique capable of producing a liquid crystal display device capable of a wide viewing angle without a line alignment film processing process of a substrate and without fine patterning of an electrode.

Example 2

Except that 0.5% by weight of the liquid crystal precursor square stabilizer compound of the above formula (10) was used as the precursor square stabilizer compound of the liquid crystal with respect to the total weight of the liquid crystal host having the negative dielectric anisotropy. Thereby obtaining a liquid crystal display element.

The alignment state of the liquid crystal in the liquid crystal display device manufactured as described above was observed using a polarization microscope. As a result, the liquid crystal was randomly arranged in the horizontal direction with respect to the substrate in the liquid crystal cell.

The non-polarized ultraviolet ray having a wavelength of 320 to 400 nm in a direction perpendicular to the substrate surface of the liquid crystal display device was immersed in the liquid crystal display device at a rate of 20 mW / cm < 2 > cm < ² > intensity.

As a result, it was confirmed that the vertical alignment of liquid crystal was induced by light irradiation for 20 minutes.

The switching behavior of the liquid crystal was observed while applying a vertical electric field (1 kHz, 10 Vpp) to the liquid crystal cell in which the vertical alignment of the liquid crystal was induced. The results are shown in Figs. 13A to 13C.

In general, a liquid crystal layer having a negative dielectric anisotropy perpendicular to the substrate exhibits a quenching state under an orthogonal polarizer as shown in FIG. 13A. When a vertical electric field is applied thereto, the liquid crystal molecules rotate in a direction perpendicular to the electric field, . However, when the vertically aligned liquid crystal layer does not form a pretilt angle in a specific direction, the direction of rotation of the liquid crystal occurs randomly according to the region of the liquid crystal cell. In this case, as shown in FIG. 13B, a large number of defects of the liquid crystal array are generated. However, such defects are slowly removed as time elapses and transition to a uniform light state as shown in FIG. 13C. At this time, the characteristics of the liquid crystal display element deteriorate due to the occurrence of defects.

In addition, the liquid crystal cell in which the vertical alignment was induced was cooled to room temperature, an electric field of 1 kHz, 10 Vpp intensity was applied, and the second light irradiation was performed again after the liquid crystal alignment was stabilized. At this time, the intensity and wavelength of the light to be irradiated were performed under the same conditions as in the case of the first light irradiation. After irradiation of the secondary light for 30 minutes, the switching characteristics according to the alignment state of the liquid crystal and the application of the electric field were observed using a polarizing microscope.

On-off switching characteristics of the device with application of an electric field were observed with a polarizing microscope, and the results are shown in Figs. 14A to 14C.

When an electric field of 1 kHz, 10 Vpp intensity is applied in the initial dark state (dark, black) as shown in FIG. 14A, the liquid crystal changes its arrangement state in response to the electric field, and thus the optical axis of the liquid crystal changes Axis and a 45-degree angle with respect to the axis, thereby directly transitioning to a light state as shown in FIGS. 14B and 14C without the generation of liquid crystal defects. This is because the precursor square stabilizer of the liquid crystal which has been dissolved in the liquid crystal layer forming composition without forming the fine aggregates by the primary light irradiation forms a fine aggregate in the secondary light irradiation process performed in the specific liquid crystal alignment state, It can be seen that the orientation of the liquid crystal is stabilized by forming a linearly inclined square in a specific direction while the fine aggregate is attached to the substrate, thereby improving the reaction rate of the liquid crystal and improving the brightness and contrast ratio of the device.

13B in which no stabilization treatment by the formation of the pretilt angle is performed and FIG. 14B in which stabilization treatment has been performed is compared with that in FIG. 14B where the stabilization treatment is performed, the occurrence of defects is eliminated and the reaction speed is also increased. It was found that the electrooptic characteristics can be improved.

Example 3

Using the same liquid crystal layer forming composition as in Example 2, except for using a substrate in which electrodes were finely patterned in a fishbone shape by dividing the pixels into four parts in order to obtain a wide viewing angle of the device, A liquid crystal display device was manufactured.

The alignment state of the liquid crystal in the liquid crystal display device manufactured as described above was observed using a polarization microscope. As a result, the liquid crystal was randomly arranged in the horizontal direction with respect to the substrate in the liquid crystal cell.

The non-polarized ultraviolet ray having a wavelength of 320 to 400 nm in a direction perpendicular to the substrate surface of the liquid crystal display device was immersed in the liquid crystal display device at a rate of 30 mW / cm < 2 > cm < ² > intensity.

As a result, it was confirmed that the vertical alignment of liquid crystal was induced by light irradiation for 10 minutes (FIG. 15A).

In addition, the switching behavior of the liquid crystal was observed while applying a vertical electric field to the liquid crystal cell in which the vertical alignment of the liquid crystal was induced. The results are shown in Figs. 15A to 15C.

Generally, a liquid crystal layer having a negative dielectric anisotropy perpendicular to the substrate exhibits a quenching state as shown in FIG. 15A under an orthogonal polarizer. When a vertical electric field is applied to the liquid crystal molecules, the liquid crystal molecules rotate in a direction perpendicular to the electric field, . However, when the vertically aligned liquid crystal layer does not form a pretilt angle in a specific direction, the direction of rotation of the liquid crystal occurs randomly according to the region of the liquid crystal cell. In this case, as shown in FIG. 15B, a large number of defects of the liquid crystal array are generated. However, such defects are slowly removed as time elapses and transition to a uniform light state as shown in FIG. 15C. At this time, the characteristics of the liquid crystal display element deteriorate due to the occurrence of defects.

In addition, an electric field having an intensity corresponding to 1 kHz and 10 Vpp was applied to the vertically aligned liquid crystal cell at room temperature, and the second light irradiation was performed again after the liquid crystal alignment was stabilized. At this time, the light irradiation was carried out at room temperature, which is the liquid crystal phase, and the wavelength of the light to be irradiated was the same as that of the primary light irradiation, and the light intensity was 30 mW / cm ² intensity. After irradiation of the secondary light for 30 minutes, the switching characteristics according to the alignment state of the liquid crystal and the application of the electric field were observed using a polarizing microscope.

On-off switching characteristics of the device with application of an electric field were observed with a polarization microscope, and the results are shown in Figs. 16A to 16C.

When an electric field of an intensity corresponding to 1 kHz and 5 Vpp is applied in the initial dark state (dark, black) as shown in FIG. 16A, the liquid crystal changes its arrangement state in response to the electric field, so that the optical axis of the liquid crystal changes And it is observed that the light is shifted to the light state as shown in FIGS. 16B and 16C without the formation of liquid crystal defects by forming an angle of 45 degrees with the transmission axis. This is because the precursor square stabilizer of the liquid crystal which has been dissolved in the liquid crystal layer forming composition without forming the fine aggregates by the primary light irradiation forms a fine aggregate in the secondary light irradiation process performed in the specific liquid crystal alignment state, It can be seen that the orientation of the liquid crystal is stabilized by forming a linearly inclined square in a specific direction while the fine aggregate is attached to the substrate, thereby improving the reaction rate of the liquid crystal and improving the brightness and contrast ratio of the device.

15B in which no stabilization treatment by the formation of a square was formed and FIG. 16B in which stabilization treatment was performed was compared with FIG. 16B in which stabilization treatment was performed, the occurrence of defects was eliminated and the reaction rate was also increased. It was found that the electrooptic characteristics can be improved.

Example 4

In order to obtain a wide viewing angle of the device, a pixel is divided into four parts to form a fishbone electrode, and a composition for forming a liquid crystal layer is applied to a fine patterned electrode to form a vertical alignment film. The procedure of Comparative Example 1-1 was repeated except that the liquid crystal precursor stabilizer compound of Formula 10 was used in an amount of 0.3% by weight based on the total weight of the liquid crystal host having negative dielectric anisotropy, A display device was manufactured.

The alignment state of the liquid crystal in the liquid crystal display device manufactured as described above was observed using a polarization microscope. As a result, the liquid crystals were uniformly arranged in the direction perpendicular to the substrate in the liquid crystal cell.

The switching behavior of the liquid crystal was observed by applying a vertical electric field to the liquid crystal cell in which the vertical alignment of the liquid crystal was induced by the conventional vertical alignment film. In this case, a large number of defects were observed due to the absence of the liquid crystal pretilt angles. The results are shown in Figs. 17A to 17C.

The vertical alignment liquid crystal cell was irradiated with an electric field having an intensity corresponding to T ₉₀ (transmittance of 90% with respect to the maximum transmittance) at room temperature, and then vertical light irradiation was performed after the liquid crystal alignment was stabilized. The non-polarized ultraviolet light having a wavelength of 320 to 400 nm in a direction perpendicular to the substrate surface of the liquid crystal display device was subjected to 20 mW / cm ² intensity for 30 minutes, and then the switching characteristics according to the alignment state of the liquid crystal and the electric field application were observed.

On-off switching characteristics of the device with application of an electric field were observed with a polarizing microscope, and the results are shown in Figs. 18A to 18C. When an electric field having an intensity corresponding to T ₉₀ (transmittance of 90% with respect to the maximum transmittance) is applied in the initial dark state (dark, black) as shown in FIG. 18A, the liquid crystal reacts to change the alignment state, It is observed that the light is shifted to the light state as shown in FIGS. 18B and 18C without the formation of liquid crystal defects by forming an angle of 45 degrees with the transmission axis of the polarizer on the substrate surface.

The above results indicate that the linear alignment stabilizer of liquid crystal which is dissolved in the composition for forming a liquid crystal layer in the light irradiation process performed in the specific liquid crystal alignment state by inducing vertical alignment by the polymer vertical alignment film pre- The micro-aggregates are formed and the formed micro-aggregates are adhered to the substrate to form a linearly inclined oblique angle, thereby stabilizing the orientation of the liquid crystal. This improves the reaction rate of the liquid crystal and improves the brightness and contrast ratio of the device .

In Fig. 17B, in which the stabilization process is not performed by the pre-scan square formation and Fig. 18B in which the stabilization process is performed, the occurrence of defects is eliminated and the reaction speed is also increased. It was found that the electrooptic characteristics can be improved.

Example 5

Except that 0.3% by weight of the liquid crystal precursor of the liquid crystal of Formula 10 was used as the total weight of the liquid crystal host having a negative dielectric anisotropy and the conventional vertical alignment film was coated on the substrate on which the electrode was formed. -1, a liquid crystal display device was manufactured.

The alignment state of the liquid crystal in the liquid crystal display device manufactured as described above was observed using a polarization microscope. As a result, the liquid crystals were uniformly arranged in the direction perpendicular to the substrate in the liquid crystal cell. The switching behavior of the liquid crystal was observed by applying a vertical electric field to the liquid crystal cell in which the vertical alignment of the liquid crystal was induced by the conventional vertical alignment film. As a result, many defects were observed due to the absence of the liquid crystal pretilt angles. The results are shown in Figs. 19A to 19C.

Subsequently, the prepared liquid crystal display device is fixed at a temperature 2 캜 higher than the nematic-isotropic phase transition temperature of the composition for forming a liquid crystal layer, and then the liquid crystal display device is immersed in the liquid crystal display device in a direction The non - polarized ultraviolet light with 400nm wavelength was irradiated for 30 minutes at 2mW / cm ² intensity, and the switching characteristics according to the arrangement state of the liquid crystal and the electric field application were observed. When an electric field exceeding the threshold voltage is applied in the initial dark state (FIG. 20A), it is observed that the light is transferred to the bright state without generating a crystal defect (FIGS. 20B to 20C). Therefore, when Fig. 19B, in which the stabilization treatment by the formation of the pretilt angle is not performed, is compared with Fig. 20B in which the stabilization treatment has been performed, the occurrence of defects is eliminated and the reaction speed is also increased. Optical characteristics of the organic EL device can be improved.

This is because the liquid crystal precursor of the liquid crystal which has been dissolved in the liquid crystal layer forming composition forms a fine aggregate by the irradiation of the oblique light and forms the preliminary crystal obliquely inclined in the specific direction with respect to the direction of the incident light, Is a phenomenon in which the orientation of the surface is stabilized.

These results demonstrate that a liquid crystal alignment pretilt angle can be imparted to a vertically aligned liquid crystal cell using a conventional alignment film in a specific direction by adding a precursor compound of a liquid crystal precursor used in the present invention and irradiating it with oblique light . That is, the additive compound used in the present invention shows that the induction of vertical orientation of liquid crystal and the formation of pre-square of liquid crystal direct can be performed simultaneously or independently.

As a result of the above, when the photomask is applied to irradiate oblique light in a plurality of different directions as in the first embodiment (FIGS. 12A to 12C), the conventional vertically- It can be seen that a multi-domain liquid crystal pre-scan square pattern can be obtained even in a liquid crystal display device manufactured after pre-processing. This is very useful because it provides a technique for fabricating a liquid crystal display device capable of a wide viewing angle without fine patterns of electrodes.

Example 6

0.3% by weight of the liquid crystal precursor of the liquid crystal of Formula 10 was added to the total weight of the liquid crystal host having a negative dielectric constant anisotropy, and the horizontal orientation film was coated on the substrate on which the electrode was formed and then uniaxial rubbing was performed. A liquid crystal display device was fabricated in the same manner as in Comparative Example 1-1 except that the cells were fabricated so that the rubbing directions of the substrates were parallel to each other.

The arrangement of liquid crystals in the liquid crystal display device manufactured in Example 10 was observed using a polarization microscope. As a result, liquid crystals were uniformly arranged in the direction parallel to the rubbing direction of the substrate surface (Fig. 21A). When a vertical electric field is applied to the liquid crystal cell, the liquid crystal does not switch at all due to negative dielectric constant anisotropy.

Then, the liquid crystal display device was fixed at a temperature two degrees higher than the nematic-isotropic phase transition temperature of the composition for forming a liquid crystal layer, and then the non-polarized ultraviolet light having a wavelength of 320 to 400 nm in a direction perpendicular to the substrate surface of the liquid crystal display device Was observed at 20mW / cm ² intensity and the switching behavior of the liquid crystal according to the irradiation time was investigated. It is observed that the angle formed by the liquid crystal direct with the substrate surface increases as the irradiation time of light is elapsed. Also, in the process of changing the inclination angle of the liquid crystal, it was found that the liquid crystal direct transition from the horizontal orientation to the vertically oriented state depending on the irradiation time in the plane formed by the rubbing axis of the surface and the incidence direction of the irradiation light. A photograph of the polarized microscope after a light irradiation time of 30 minutes has elapsed is shown in Fig. The quenching state shown in the photograph shows that the liquid crystal direct is arranged perpendicular to the substrate surface, and it can be understood that the device manufactured using the horizontal alignment film can be transferred to the vertical alignment by using the principle of the present invention. However, by observing the direction of the optical axis using the conoscopic, it was found that the optical axis of the liquid crystal was slightly inclined toward the rubbing direction with respect to the vertical direction of the substrate surface. Quantitative measurement of the angle of inclination showed that the substrate was tilted about 2.1 degrees from the vertical direction to the rubbing direction.

Then, the switching characteristics of the liquid crystal display device according to the application of the electric field were observed. When an electric field equal to or higher than the threshold voltage is applied in the initial dark state (FIG. 21B), it is observed that the liquid crystal director is uniformly rotated in the direction parallel to the rubbing axis, and transitioned to the bright state (FIG. 21A) without generating liquid crystal defects.

This is because the linear stabilizer of the liquid crystal which is dissolved in the composition for forming a liquid crystal layer forms a fine aggregate by light irradiation and the fine aggregate formed is in competition with the rubbed horizontal alignment film in the course of strengthening the vertical alignment property Indicates that the liquid crystal molecules are shifted in the same azimuth angle from horizontal to vertical. Thus, the degree of tilt varies depending on the degree of competition, but the tilted direction always faces the rubbing axis.

From these results, it can be seen that the oblique direction in the vertical alignment ultimately obtained can be controlled by rubbing the horizontal alignment film. It was also found that the degree of inclination can be controlled differently depending on the concentration of the orientation-inducing additive, the intensity of light irradiation, and the time.

Example 7

The same procedure as in Example 1 was carried out except that 0.3 weight% of the compound of the following formula (11) was used as the linear stabilizer compound of the liquid crystal with respect to the total weight of the liquid crystal host having negative dielectric anisotropy, A liquid crystal display device in which a square was stably induced was prepared.

(11)

(11)

(Wherein n is an integer of 12)

The liquid crystal precursor square stabilizer compound of Formula 11 comprises a rigid-core comprising one azooxy group as a light-modifying group and formed by four aromatic groups (i.e., a phenylene group) and two ester groups, And the dodecaoxy group is respectively substituted. The molecular weight of the rigid-core portion is 436 g / mol and the total molecular weight is 806 g / mol. In addition, the compound additive shows a liquid crystal phase and has a low affinity with a liquid crystal host molecule due to a high molecular weight, a long linear symmetric core group and a symmetrical molecular structure, and exhibits solubility of 1.5 wt% Is a low compound.

Example 8

Except that 1.0 weight% of a Schiff base compound represented by the following formula (12) was used as the linear stabilizer compound of the liquid crystal with respect to the total weight of the liquid crystal host having a negative dielectric constant anisotropy: Thereby producing a liquid crystal display element in which the linear polarization angle of the liquid crystal was stably induced.

(12)

(12)

(Wherein n is an integer of 8)

The liquid crystal precursor square stabilizer compound of formula (12) includes a rigid-core formed by four aromatic groups (i.e., a phenylene group) including one imine group as a light-modifying group, As the substituted compound, the molecular weight of the rigid-core portion is 418 g / mol and the total molecular weight is 676 g / mol. In addition, the compound additive shows a liquid crystal phase and has a low affinity with a liquid crystal host molecule due to a high molecular weight, a long linear symmetric core group and a symmetrical molecular structure, and exhibits solubility of 1.5 wt% Is a low compound.

Example 9

The procedure of Example 1 was repeated except that the cholesterol derivative represented by the following formula (13) was used in an amount of 2.0% by weight based on the total weight of the liquid crystal host having a negative dielectric constant anisotropy as the precursor of the chiral array liquid crystal: To thereby produce a liquid crystal display device in which a linearly arranged square of liquid crystal was stably induced.

(13)

(13)

(Wherein X ₁₄ = O, Y ₁₄ = -O (OC) -, R = -CH ₂ CH ₃ and n = 10)

The liquid crystal precursor square stabilizer compound of the above formula (13) includes a chiral group and an azo group, and two rigid groups (i.e., aromatic group and cycloalkyl group) are connected by a flexible group, and the molecular weight of the rigid- The total molecular weight is 792 g / mol. The compound additive is a compound exhibiting a solubility of 3.0 wt% with respect to the liquid crystal host.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

1, 1 '11, 21 substrate
2, 2 '12, and 22 electrodes
3, 3 'polymer alignment layer
4, 13a, 13b, 13c liquid crystal layer
14, 24 liquid crystal pre-curved rectangular guiding layer
15, 25 liquid crystal pre-curved square stabilization layer

Claims (18)

An electrode forming step of forming first and second electrodes on the first substrate and the second substrate, respectively;
The first substrate and the second substrate each including the first and second electrodes are bonded to each other with the electrodes facing each other, and then the liquid crystal layer forming composition is injected into the space between the first substrate and the second substrate, A composition for forming a liquid crystal layer was dropped on any one of a first substrate and a second substrate each including a first electrode and a second electrode under vacuum to form a liquid crystal layer and then the remaining substrates were bonded so that the electrodes face each other, Producing; And
And inducing a preliminary square of the liquid crystal by light irradiation on the assembly,
Wherein the composition for forming a liquid crystal layer comprises a liquid crystal host and a liquid crystal precursor,
Wherein the linear quadrangular stabilizer of the liquid crystal comprises a rigid-core portion including at least two cyclic functional groups selected from the group consisting of an aromatic group, an alicyclic group and a heterocyclic group, and a trans- A compound having a structure including a flexible group bonded to a terminal or a side,
Wherein the compound has a molecular weight of 380 to 1,000 g / mol and a solubility in a liquid crystal host of 0.01 to 3% by weight. The method according to claim 1,
Wherein the liquid crystal precursor square stabilizer is contained in an amount of 0.05 to 2% by weight based on the total weight of the composition for forming a liquid crystal layer. The method according to claim 1,
Wherein the trans-cis photochromic group is at least one selected from the group consisting of an azo group, an azo group, and an imine group. The method according to claim 1,
Wherein the rigid-core addition comprises from 4 to 6 cyclic functional groups selected from the group consisting of an aromatic group, an alicyclic group and a heterocyclic group, and a trans-cis photochromic group, wherein the cyclic functional groups are directly connected to each other, An alkylene group having 2 to 20 carbon atoms, an alkenyl-diyl group having 2 to 20 carbon atoms, an alkyne-diyl group having 2 to 30 carbon atoms, a fluoroalkylene group having 1 to 20 carbon atoms, a hetero atom and a heteroalkylene having 1 to 20 carbon atoms And a molecular weight of the rigid-core portion is 320 to 800 g / mol. The method according to claim 1,
A hydrocarbon group of 1 to 20 carbon atoms in which the flexible group is substituted or unsubstituted with a halogen group; A heteroalkyl group having 1 to 20 carbon atoms which contains at least one heteroatom selected from the group consisting of N, O, P, S and Si in the functional group and is substituted or unsubstituted with a halogen group; And a combination thereof. ≪ Desc / Clms Page number 24 > The method according to claim 1,
Wherein the linear stabilizer of the liquid crystal comprises a compound of the following formula (1).
[Chemical Formula 1]

In this formula,
A and B are each independently a trans-cis-optic transition group selected from the group consisting of an azo group, an azooxy group and an imine group,
R ₁ and R ₂ each independently represent a hydrocarbon group having 1 to 20 carbon atoms which is substituted or unsubstituted with a halogen group, at least one heteroatom selected from the group consisting of N, O, P, S and Si in a functional group, A substituted or unsubstituted C1 to C20 heteroalkyl group substituted with a halogen group, and a combination thereof,
Ra to Rc are each independently selected from the group consisting of a halogen group, an alkyl group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, and a combination thereof,
X is a functional group of formula (I)
[Formula 1a]

(Wherein X ₁ represents an alkylene group having 1 to 20 carbon atoms, an alkenyl-diyl group having 2 to 20 carbon atoms, an alkyne-diyl group having 2 to 20 carbon atoms, a fluoroalkylene group having 1 to 20 carbon atoms, a carbonyl group, Wherein R _d is selected from the group consisting of a halogen group, an alkyl group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, and an alkyl group having 1 to 10 carbon atoms; P is an integer of 0 to 4, and x is an integer of 0 or 1,
Y is a functional group of the following formula (1b)
[Chemical Formula 1b]

Y ₁ represents an alkylene group having 1 to 20 carbon atoms, an alkene-diyl group having 2 to 20 carbon atoms, an alkyne-diyl group having 2 to 20 carbon atoms, a fluoroalkylene group having 1 to 20 carbon atoms, a carbonyl group, Re is a group selected from the group consisting of a halogen group, an alkyl group having 1 to 10 carbon atoms, a fluoroalkyl group having 1 to 10 carbon atoms, and an alkyl group having 1 to 10 carbon atoms, Q is an integer of 1 to 4, and y is an integer of 0 or 1,
a to c are each independently an integer of 0 or 1, and
l to n are each independently an integer of 0 to 4; The method according to claim 1,
Wherein the linearly guided square guide is carried out by any one of the following methods:
1) a method of irradiating light using oblique incident light whose incidence direction of light is inclined at an angle of less than 90 DEG with respect to the substrate surface
2) irradiating the substrate with light in the vertical direction to induce vertical alignment of the liquid crystal, and then performing secondary light irradiation for irradiating obliquely incident light whose incidence direction of light is inclined at an angle of less than 90 DEG with respect to the substrate surface Way
3) a method of irradiating light in the vertical direction of the substrate to induce the vertical alignment of the liquid crystal, then applying an electric field to the assembly in the vertical alignment state of the liquid crystal, and performing second light irradiation
4) A method of irradiating oblique incidence light in which the direction of incidence of light is inclined at an angle of less than 90 ° with respect to the substrate surface by using a vertically aligned substrate having no pre-scan angle formed as the first and second substrates in the manufacture of the assembly
5) A vertically aligned substrate and a liquid crystal having a negative dielectric constant anisotropy were used as the first and second substrates in the manufacture of the assembly, and light irradiation was performed under the application of a vertical electric field when the linearly polarized light was guided How to induce a square box
6) A method in which a substrate having a horizontally oriented film rubbed as a first and a second substrate during manufacture of the assembly is used and light irradiation is performed to induce a pretilt angle
7) A method of inducing pre-warping square by irradiating light with the rubbed horizontally oriented film in the production of assembly and controlling the arrangement of liquid crystal by applying electric field A liquid crystal display device manufactured by the manufacturing method according to claim 1. A rigid-core portion comprising two or more cyclic functional groups selected from the group consisting of an aromatic group, an alicyclic group and a heterocyclic group, and a trans-cis-photo-modifying group, and a flexible group bonded to the terminal or side of the rigid- And having a molecular weight of 380 to 1,000 g / mol and a solubility in a liquid crystal host of 0.01 to 3% by weight. A method for inducing a pretilt angle of a liquid crystal by irradiating a composition for forming a liquid crystal layer comprising a liquid crystal precursor and a liquid crystal host according to claim 9. delete delete delete delete delete delete delete delete

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