KR102066405B1 - Liquid crystal display device and Method for manufacturing the same - Google Patents

Abstract

The present invention, the first substrate and the second substrate facing each other; A liquid crystal layer formed between the first substrate and the second substrate; A color filter layer formed on the first substrate; And a light shielding layer formed in a matrix structure on the color filter layer, wherein the light shielding layer comprises a light shielding agent and a dispersant covering the surface of the particle of the light shielding agent, and the dispersing agent particles of the light shielding agent. 1. A liquid crystal display and a method of manufacturing the same, comprising a first dispersant which first coats a surface and a second dispersant which secondly coats a particle surface of the light shielding agent.
According to the present invention, since the dispersant covers the particle surface of the light shielding agent, the functional groups on the surface of the light shielding agent are prevented from binding to the color filter layer, whereby a precise light shielding layer pattern can be obtained.

Description

Liquid crystal display device and method for manufacturing the same

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device in which a light shielding layer is formed on a color filter layer.

Liquid crystal display devices have a wide range of applications ranging from notebook computers, monitors, spacecrafts, aircrafts, etc. to the advantages of low power consumption and low power consumption.

The liquid crystal display device includes an upper substrate, a lower substrate, and a liquid crystal layer formed between the two substrates, and the arrangement state of the liquid crystal layer is adjusted according to whether an electric field is applied, and accordingly, the light transmittance is adjusted to display an image. to be.

Hereinafter, a conventional liquid crystal display device will be described with reference to the drawings.

1 is a schematic cross-sectional view of a liquid crystal display according to an exemplary embodiment.

As can be seen in FIG. 1, a liquid crystal display according to an exemplary embodiment includes an upper substrate 10, a lower substrate 20, and a liquid crystal layer 30 formed between the substrates 10 and 20. Is done.

A light blocking layer 14 is formed on the upper substrate 10 to prevent light leakage, and color filters of red (R), green (G), and blue (B) are formed on the light blocking layer 14. 12) is formed.

Although not shown, gate lines, data lines, thin film transistors, and pixel electrodes are formed on the lower substrate 20.

In the liquid crystal display according to the conventional exemplary embodiment, an image is displayed while light emitted from a backlight unit (not shown) positioned below the lower substrate 20 is emitted through the upper portion of the upper substrate 10. In this case, since the light blocking layer 14 is located far from the backlight unit which is a light source, there is a disadvantage in that light is mixed between adjacent pixels according to the viewing angle. Therefore, in order to solve such drawbacks, a liquid crystal display device as shown in FIG. 2 is proposed.

2 is a schematic cross-sectional view of a liquid crystal display according to another exemplary embodiment.

As can be seen in FIG. 2, according to another exemplary embodiment, a color filter 12 of red (R), green (G), and blue (B) is first formed on the upper substrate 10, and the color is formed. The light shielding layer 14 is formed on the filter 12.

In the liquid crystal display of FIG. 2, since the light blocking layer 14 is located relatively close to the backlight unit, which is a light source, compared to the liquid crystal display of FIG. The problem of mixing is reduced.

However, the liquid crystal display according to FIG. 2 has a problem in that the light blocking layer 14 remains in the pixel area after the pattern process, thereby deteriorating image quality and decreasing transmittance. This will be described in detail below.

The light blocking layer 14 is coated on the color filter 12, and then patterned in a boundary region between the plurality of pixels through a patterning process. However, in the related art, the light shielding material constituting the light shielding layer 14 and the color filter 12 are bonded to each other, so that the pattern forming process of the light shielding layer 14 may not be precisely performed. That is, in the pattern forming process of the light blocking layer 14, the light blocking material in the pixel area is removed and the light blocking material in the boundary area between the pixels remains to form the light blocking layer 14 pattern. The coupling force between the color filters 12 is good, so that the light blocking material in the pixel area is not completely removed and a problem remains.

The present invention has been devised to solve the above-mentioned problems, and the present invention provides precise pattern formation, that is, the light shielding material in the pixel area is removed and the light shielding material in the boundary area between the pixels is removed. It is characterized by providing a liquid crystal display device and a method of manufacturing the same.

The present invention, in order to achieve the above object, a first substrate and a second substrate facing each other; A liquid crystal layer formed between the first substrate and the second substrate; A color filter layer formed on the first substrate; And a light shielding layer formed in a matrix structure on the color filter layer, wherein the light shielding layer comprises a light shielding agent and a dispersant covering the surface of the particle of the light shielding agent, and the dispersing agent particles of the light shielding agent. It provides a liquid crystal display device comprising a first dispersant which firstly covers the surface and a second dispersant which secondly covers the particle surface of the light shielding agent.

The present invention provides a process for forming a color filter layer on a first substrate; Forming a light shielding layer in a matrix structure on the color filter layer; And bonding the first substrate and the second substrate with a liquid crystal layer interposed therebetween, wherein the forming of the light blocking layer comprises a light shielding agent, a dispersing agent, a binder, a crosslinking agent, an initiator, a surfactant, and a solvent. A process for producing a light shielding composition comprising a, a process of applying the light shielding composition to the entire surface of the substrate including the color filter layer, and a step of patterning the applied light shielding composition, the process of manufacturing the light shielding composition is the light shielding Preparing a first light-shielding composition by mixing the first and second dispersants and a solvent, and then mixing the binder, the crosslinking agent, an initiator, and a surfactant with the first light-shielding composition and reacting to prepare a second light-shielding composition. Provided is a method of manufacturing a liquid crystal display device.

According to the present invention has the following effects.

According to the present invention, since the dispersant covers the particle surface of the light shielding agent, the functional groups on the surface of the light shielding agent are prevented from binding to the color filter layer, whereby a precise light shielding layer pattern can be obtained.

Therefore, the present invention can solve the problem that the light shielding layer remains in the pixel region after the pattern process, and thus the image quality is lowered and the transmittance is lowered.

Particularly, in the present invention, since the first dispersant having a relatively small molecular weight first coats the particle surface of the light shielding agent, and the second dispersant having a relatively large molecular weight secondly covers the particle surface of the light shielding agent, The functional groups on the surface can more effectively block the binding of the color filter layer.

1 is a schematic cross-sectional view of a liquid crystal display according to an exemplary embodiment.
2 is a schematic cross-sectional view of a liquid crystal display according to another exemplary embodiment.
3 is a schematic cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.
4A to 4D are schematic cross-sectional views illustrating a manufacturing process of a liquid crystal display according to an exemplary embodiment of the present invention.
5 (a) to 5 (c) are photographs of each of the red (R), green (G), and blue (B) color filters formed in the pixel area in the liquid crystal display according to the present invention.

The term " on " as used herein means to include not only when a certain configuration is formed on the immediate surface of another configuration but also when a third configuration is interposed between these configurations.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a schematic cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.

As can be seen in FIG. 3, the liquid crystal display according to the exemplary embodiment of the present invention may include a first substrate 100, a second substrate 200 facing the first substrate 100, and both substrates 100,. It comprises a liquid crystal layer 300 formed between the 200.

The first substrate 100 may constitute an upper substrate of the liquid crystal display and may be made of glass or transparent plastic material. The color filter layers 120a, 120b, and 120c are formed on the first substrate 100, and the light blocking layer 140 is formed on the color filter layers 120a, 120b, and 120c, and the light shielding layer 140 is formed. ), An overcoat layer 160 is formed. That is, the color filter layers 120a, 120b, and 120c are formed between the first substrate 100 and the light blocking layer 140, and the light blocking layer 140 is formed of the color filter layers 120a, 120b, and 120c. It is formed between the overcoat layer 160.

The color filter layers 120a, 120b, and 120c include a first color filter 120a, a second color filter 120b, and a third color filter 120c.

The first color filter 120a is formed of any one of red (R), green (G), and blue (B), and the second color filter 120b is red (R), green ( G) and the other one of the blue (B) color filters, and the third color filter 120c includes the other one of the red (R), green (G), and blue (B) color filters. Can be.

An area in which the first color filter 120a, the second color filter 120b, and the third color filter 120c are formed corresponds to an area displaying an image.

The first color filter 120a, the second color filter 120b, and the third color filter 120c may be formed to overlap each other as illustrated, but may be formed to be spaced apart from each other in some cases.

The position at which the first color filter 120a, the second color filter 120b, and the third color filter 120c are formed may be changed in various forms known in the art. In addition, a fourth color filter may be additionally formed in addition to the first color filter 120a, the second color filter 120b, and the third color filter 120c.

The light blocking layer 140 is formed in a boundary area between a plurality of pixels in the display area to block light leakage from the boundary area. Therefore, the light blocking layer 140 includes a light blocking material formed in a matrix structure.

Specifically, the light blocking layer 140 includes a light blocking agent, a dispersant, a binder, a crosslinking agent, an initiator, and a surfactant.

The additive light shielding agent may be formed of carbon black as a core component for performing the light leakage blocking function of the light blocking layer 140.

The light blocking agent may be included in an amount of 45 wt% to 50 wt% in the entire light blocking layer 140. When the light shielding agent is included in less than 45% by weight, the light leakage blocking function of the light shielding layer 140 may be reduced, and when the light shielding agent is included in more than 55% by weight may reduce the dispersibility of the light blocking agent.

The dispersant may be formed of an epoxy compound as a function of dispersing the light blocking agent. In particular, as can be seen in the enlarged view drawn by the arrow of FIG. 3, the dispersant 142 covers the surface of the light blocking agent 141, for example, carbon black, so that the carbon black and the color filter layers 120a and 120b. By blocking the coupling between the layers 120c, the pattern precision of the light blocking layer 140 may be improved.

In detail, the light blocking layer 140 is coated on the color filter layers 120a, 120b, and 120c to form a pattern in a boundary region between a plurality of pixels through a patterning process. do. However, if the coupling is made between the light blocking agent 141 constituting the light blocking layer 140 and the color filter layers 120a, 120b, and 120c, the pattern of the light blocking layer 140 may not be obtained after the patterning process. I can't. In particular, since the carbon black has various functional groups such as H, O, CO, OH, and COOH, the carbon black may be easily combined with the color filter layers 120a, 120b, and 120c, and in this case, after the patterning process, the light blocking layer ( The pattern may remain not only in the boundary region between the plurality of pixels but also in the plurality of pixel regions, thereby causing a problem of deterioration of image quality and a problem of decreasing transmittance.

According to the present invention, since the dispersant 142 covers the surface of the particles of the light blocking agent 141, the functional groups on the surface of the light blocking agent 141 are blocked from binding to the color filter layers 120a, 120b, and 120c. As a result, an accurate light shielding layer 140 pattern may be obtained.

In particular, in order to cover the particle surface of the light blocking agent 141, the dispersant 142 is composed of a first dispersant having a relatively small molecular weight and a second dispersant having a relatively large molecular weight. That is, since the first dispersant having a relatively small molecular weight first coats the particle surface of the light shielding agent 141, and the second dispersant having a relatively large molecular weight secondly covers the surface of the particle of the light shielding agent 141. In addition, the functional groups on the surface of the particles of the light blocking agent 141 may block the color filter layers 120a, 120b, and 120c more effectively.

The first dispersant may be composed of an epoxy compound having a molecular weight of less than 8,000, for example, a molecular weight of 5,000, and the second dispersant may be composed of an epoxy compound having a molecular weight of 8,000 or more, for example, a molecular weight of 10,000.

Such a dispersant 142 may be included in an amount of 5 to 10% by weight in the entire light shielding layer 140. When the dispersant 142 is included in less than 5% by weight, the coating function of the surface of the particle of the light blocking agent 141 may be deteriorated, and when the dispersant 142 is included in more than 10% by weight of the light blocking layer 140 The light shielding function may be degraded. The first and second dispersants may be included in a weight ratio of 1: 9 to 9: 1.

The binder may be formed of a cardo-based compound, which serves to enhance the bonding force of the components constituting the light blocking layer 140.

The binder may be included in 30 to 40% by weight of the entire light shielding layer 140. When the binder is included in less than 30% by weight, the bonding strength of the components constituting the light shielding layer 140 may be reduced, and when the binder is included in excess of 40% by weight, the light blocking function of the light shielding layer 140 may be reduced. have.

The crosslinking agent serves as a crosslinking role when the components constituting the light shielding layer 140 are combined, and the crosslinking agent is made of a multifunctional monomer (MM). The multifunctional monomer may include a compound represented by Chemical Formula 1 having four functional groups or a compound represented by Chemical Formula 2 having six functional groups.

Formula 1

Formula 2

The crosslinking agent may be included in an amount of 4 to 14 wt% in the light shielding layer 140. When the crosslinking agent is included in less than 4% by weight, the crosslinking role may be reduced, and when the crosslinking agent is included in excess of 14% by weight, the line width (CD) of the light shielding layer 140 may be increased, thereby making it difficult to implement a fine pattern.

The initiator serves to initiate a reaction of the light blocking layer 140 and may be made of an oxime A type or an oxime B type compound.

The initiator may be included in 5 to 15% by weight of the entire light shielding layer 140. When the initiator is included in less than 5% by weight, the initiation role may be reduced, and when the initiator is included in an amount of more than 15% by weight, the line width (CD) of the light shielding layer 140 may be increased, thereby making it difficult to implement a fine pattern.

The surfactant may be made of a fluorine-based surfactant. Such a surfactant may be included in 0.3 ~ 1% by weight in the entire light shielding layer 140. If the surfactant is contained in less than 0.3% by weight, the function of the surfactant is not made smoothly, when the surfactant is contained in more than 1% by weight may cause staining.

The overcoat layer 160 is formed on the entire surface of the substrate including the light blocking layer 140 to planarize the substrate. Although not shown, a column spacer for maintaining a cell gap may be further formed on the overcoat layer 160.

The second substrate 200 may constitute a lower substrate of the liquid crystal display and may be made of glass or transparent plastic material. Although not shown on the second substrate 200, a thin film transistor functioning as a switching element is formed in a region where the gate line and the data line are arranged to cross each other to define a pixel region, and the gate line and the data line cross each other. A pixel electrode is formed in the pixel region, and a common electrode for driving the liquid crystal layer 300 is formed together with the pixel electrode.

Specific configurations of the first substrate 100 and the second substrate 200 as described above may include a driving mode of a liquid crystal display device, for example, a twisted nematic (TN) mode, a vertical alignment (VA) mode, and an in plane (IPS). According to the switching mode, the FFS (Fringe field switching) mode, and the like, various modifications may be made in the form known in the art.

4A to 4D are schematic cross-sectional views illustrating a manufacturing process of a liquid crystal display according to an exemplary embodiment of the present invention.

First, as shown in FIG. 4A, the color filter layer 120a including the first color filter 120a, the second color filter 120b, and the third color filter 120c on the first substrate 100 may be formed. 120b and 120c are formed.

The color filter layers 120a, 120b, and 120c may be patterned in the order of a blue (B) color filter, a red (R) color filter, and a green (G) color filter, but are not necessarily limited thereto.

The first color filter 120a, the second color filter 120b, and the third color filter 120c may be formed to overlap each other as illustrated, but may be formed to be spaced apart from each other in some cases.

In addition to the first color filter 120a, the second color filter 120b, and the third color filter 120c, a fourth color filter may be further formed.

Next, as shown in FIG. 4B, the light blocking layer 140 is formed on the color filter layers 120a, 120b, and 120c in a matrix structure.

The light blocking layer 140 may be formed by manufacturing a light blocking composition, applying the light blocking composition to the entire surface of the substrate including the color filter layers 120a, 120b, and 120c, and then patterning the applied light blocking composition. . The patterning process may use a photolithography method.

The light shielding composition comprises a light shielding agent, a dispersing agent, a binder, a crosslinking agent, an initiator, a surfactant, and a solvent.

Since specific configurations of the light-shielding agent, dispersant, binder, crosslinking agent, initiator, and surfactant are the same as described above, repeated description will be omitted.

The solvent is an organic solvent, such as 3-Methoxy butyl acetate, Tetra methyl urea, Propylene glycol mono methyl ether acetate, and butane diol It may be composed of at least one solvent selected from the group consisting of diacetate (Butane diol di-acetate).

The solvent is included in 75 to 85% by weight of the total light-shielding composition, the total of the remaining components, that is, the total of the light-shielding agent, dispersant, binder, cross-linking agent, initiator, and surfactant from 15 to 25 throughout the light-shielding composition It may be included in weight percent.

The solvent is removed by a drying process or the like and is not finally included in the light blocking layer 140.

According to an embodiment of the present invention, the light shielding composition is prepared by first mixing the light shielding agent, the dispersing agent and the solvent, and then preparing a binder, a crosslinking agent, an initiator, and an interface to the first light shielding composition. The active agent may be mixed and then reacted to prepare a second light blocking composition.

The process of preparing the first light-shielding composition includes coating the dispersant on the surface of the light-shielding agent, and the particle surface of the light-shielding agent is first coated with the first dispersant by the coating process, Secondary coating.

This coating process may include milling, since heat may occur when the milling process is performed, so that the components react during the milling process when the binder, the crosslinking agent, and the initiator are mixed together from the beginning. The coating process of the surface of the light shielding agent may not be performed smoothly.

Therefore, according to one embodiment of the present invention, the first light-shielding composition is prepared by first coating the light-shielding agent surface with a dispersant, and then mixing the binder, the crosslinking agent, the initiator, and the like, thereby dispersing the surface of the light-shielding agent. Can increase the coverage.

Next, as shown in FIG. 4C, an overcoat layer 160 is formed on the light blocking layer 140. The overcoat layer 160 may be formed on the entire surface of the substrate including the light blocking layer 140.

Although not shown, a column spacer for maintaining a cell gap may be further formed on the overcoat layer 160.

Next, as shown in FIG. 4D, the first substrate 100 and the second substrate 200 are bonded to each other with the liquid crystal layer 300 interposed therebetween.

The gate line and the data line, the thin film transistor, the pixel electrode, and the common electrode may be formed on the second substrate 200 as described above in various ways known in the art.

The process of bonding the first substrate 100 and the second substrate 200 with the liquid crystal layer 300 therebetween may be performed using a vacuum injection method or a liquid crystal drop method known in the art.

That is, a vacuum injection method may be used in which a liquid crystal is injected through an injection hole provided in the sealant after bonding the first substrate 100 and the second substrate 200 using a sealant. And dropping the liquid crystal onto any one of the first substrate 100 and the second substrate 200 and then bonding the two substrates 100 and 200 using a sealant. Can also be used.

5 (a) to 5 (c) are photographs of each of the red (R), green (G), and blue (B) color filters formed in the pixel region in the liquid crystal display according to the present invention.

As can be seen from Figs. 5 (a) to 5 (c), it can be seen that no light shielding layer material remains on each color filter.

100: first substrate 120a, 120b, 120c: first, second, third color filters
140: light shielding layer 141: light shielding agent
142: dispersant 160: overcoat layer
200: second substrate 300: liquid crystal layer

Claims (12)

A first substrate and a second substrate facing each other;
A liquid crystal layer formed between the first substrate and the second substrate;
A color filter layer formed on the first substrate; And
It includes a light blocking layer formed in a matrix structure on the color filter layer,
The light shielding layer includes a light shielding agent and a dispersant covering the particle surface of the light shielding agent therein, and the dispersing agent firstly covers the particle surface of the light shielding agent and the particle surface of the light shielding agent. Consisting of a second dispersant coating the secondary
The light blocking layer is in contact with the color filter layer. The method of claim 1,
Wherein the light blocking agent is made of carbon black, the dispersing agent is made of an epoxy compound, and the first dispersing agent is made of an epoxy compound having a lower molecular weight than the second dispersant. The method of claim 1,
The light blocking layer further comprises a binder, a crosslinking agent, an initiator, and a surfactant. The method of claim 3,
The binder is made of a cardo-based compound, the crosslinking agent is made of a multifunctional monomer, the initiator is made of an oxime A type or an oxime B type compound, and the surfactant is a fluorine-based compound. Liquid crystal display device comprising a surfactant. The method of claim 3,
The light shielding agent is included in 45 to 50% by weight in the entire light shielding layer,
The dispersant is included in 5 to 10% by weight in the entire light shielding layer,
The binder is contained in 30 to 40% by weight in the entire light shielding layer,
The crosslinking agent is included in 4 to 14% by weight in the entire light shielding layer,
The initiator is included in 5 to 15% by weight in the entire light shielding layer, And
The surfactant is a liquid crystal display, characterized in that contained in 0.3 to 1% by weight in the entire light shielding layer. Forming a color filter layer on the first substrate;
Forming a light shielding layer in a matrix structure on the color filter layer; And
And bonding the first substrate and the second substrate with a liquid crystal layer interposed therebetween,
The step of forming the light shielding layer is a step of manufacturing a light shielding composition comprising a light shielding agent, a dispersing agent, a binder, a crosslinking agent, an initiator, a surfactant, and a solvent, a step of applying the light shielding composition to the entire surface of the substrate including the color filter layer And patterning the applied light shielding composition,
In the process of preparing the light shielding composition, the light shielding agent, the dispersing agent, and the solvent are mixed to prepare a first light shielding composition, and then the binder, the crosslinking agent, the initiator, and the surfactant are mixed with the first light shielding composition and reacted. A process of preparing a second light shielding composition,
And the light blocking layer is in contact with the color filter layer. The method of claim 6
The process of manufacturing the first light shielding composition includes the step of coating the dispersant on the surface of the light shielding agent. The method of claim 7, wherein
The dispersant comprises a first dispersant and a second dispersant having a molecular weight greater than that of the first dispersant, and the surface of the light-shielding agent is first coated with the first dispersant by the coating process, Method for manufacturing a liquid crystal display device, characterized in that the car is covered. The method of claim 6,
The light shielding agent is made of carbon black,
The dispersant is composed of an epoxy compound,
The binder is made of a cardo-based compound,
The crosslinking agent consists of a multifunctional monomer,
The initiator consists of an oxime A type or an oxime B type compound,
The surfactant consists of a fluorine-based surfactant, and
The solvent is 3-Methoxy butyl acetate, Tetra methyl urea, Propylene glycol mono methyl ether acetate, and Butane diol diacetate. -acetate) manufacturing method of a liquid crystal display device, characterized in that consisting of at least one organic solvent selected from the group consisting of. The method of claim 6,
The light shielding agent is included in 45 to 50% by weight in the entire light shielding layer,
The dispersant is included in 5 to 10% by weight in the entire light shielding layer,
The binder is contained in 30 to 40% by weight in the entire light shielding layer,
The crosslinking agent is included in 4 to 14% by weight in the entire light shielding layer,
The initiator is included in 5 to 15% by weight in the entire light shielding layer, And
The surfactant is a manufacturing method of the liquid crystal display device, characterized in that contained in 0.3 to 1% by weight in the entire light shielding layer. The method of claim 1,
The color filter layer includes a first color filter and a second color filter overlapping each other. The method of claim 11,
And the light blocking layer is formed to overlap a region where the first color filter and the second color filter overlap.

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