JP2006243207A - Liquid crystal display device, color filter for liquid crystal display device and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a PVA mode liquid crystal display device excellent in display quality, a color filter capable of manufacturing such a liquid crystal display device, and a method for manufacturing the color filter.
SOLUTION: A plurality of colored layers arranged in a predetermined pattern on a transparent substrate, and a common transparent electrode covering these colored layers, wherein the common transparent electrode is arranged in an orientation direction of liquid crystal molecules. The color filter used in the PVA mode liquid crystal display device by having a slit for controlling the liquid crystal in a plurality of directions, and in the manufacture of such a color filter, the slit formation planned portion of the common transparent electrode on the colored layer After forming the resin pattern on the substrate and forming the common transparent electrode so as to cover the colored layer and the resin pattern, the resin pattern is removed, and at the same time, the common transparent electrode on the resin pattern is also removed (lifted off) and aligned. A common transparent electrode having a control slit was formed.
[Selection] Figure 2

Description

  The present invention relates to a liquid crystal display device excellent in display quality, in particular, a liquid crystal display device of a multi-alignment division type vertical alignment mode, a color filter capable of manufacturing such a liquid crystal display device, and a method of manufacturing the color filter.

In recent years, liquid crystal display devices (LCDs) have attracted attention as flat displays, and due to their features such as thinness, light weight, and low power consumption, the market from personal computers (PCs), mobile phones, video cameras, etc. to large screen televisions is rapidly growing. Has expanded to.
When an LCD, particularly a large LCD, is considered, uniform brightness, contrast, etc. are required regardless of the viewing angle over the entire screen. However, in the twisted alignment mode (TN-LCD) that has been widely used in the past, the narrow viewing angle has been a big problem. Thus, in recent years, many viewing angle improvement modes such as an In Plane Switching mode (IPS mode) and an optical compensation TN mode have been developed.

As one of such viewing angle improvement modes, the multi-domain vertical alignment mode (MVA mode) is (1) wide viewing angle, (2) high contrast, and (3) high speed. Currently, it is attracting widespread attention because of its superior response.
In order to realize the above-mentioned multiple alignment division (the alignment direction of liquid crystal molecules is a plurality of directions), so-called multi-domaining, a method of repeating mask rubbing a plurality of times at first was considered. There were many problems such as generation of static electricity due to the rubbing process, a decrease in yield due to dust generation, and a decrease in productivity due to complicated processes.

  In view of this, a technique has been developed in which protrusions are provided in the liquid crystal panel to control the tilt direction of liquid crystal molecules without using a rubbing technique (Patent Document 1). The protrusions for controlling the alignment of the liquid crystal molecules can be formed in, for example, a 45 ° zigzag stripe shape having a bent portion so that the alignment direction in one pixel is divided into four and the divided areas are equal. Designed to. Further, the protrusions can be provided on both the color filter side and the TFT (Thin Film Transistor) substrate side. In this case, when the two substrates are made to face each other, both protrusions are alternately arranged. Configured as follows. Such protrusions have a role of imparting a pretilt angle to the liquid crystal molecules and distorting the lines of electric force. Due to these two effects, the liquid crystal molecules are aligned in a plurality of different directions when a voltage is applied. .

However, in the MVA mode liquid crystal display device having the above-described protrusions, a process for forming the protrusions is newly required, resulting in an increase in manufacturing processes. In order to solve this problem, recently, instead of providing the above protrusion on the TFT substrate side, a patterned-domain vertical alignment (PVA) mode liquid crystal in which a slit is provided in a transparent electrode as a virtual alignment control protrusion A display device has been developed (Patent Document 2).
Japanese Patent Laid-Open No. 11-242225 Japanese Patent Laid-Open No. 10-104645

In the conventional color filter used for the liquid crystal display device of PVA mode, in order to protect the colored layer from the acidic etching solution in the step of forming the common transparent electrode having a desired slit on the colored layer, the transparent layer and the common transparent electrode are used. A transparent protective layer is disposed between the electrodes. However, this transparent protective layer has a low light transmittance on the short wavelength side, which causes a problem that yellowing occurs on the screen.
In addition, in the production of conventional color filters, as described above, the number of processes for forming a transparent protective layer for protecting the colored layer from the acidic etching solution used in the etching process has increased, which hindered the improvement of manufacturing efficiency. It was.

Moreover, it is possible to eliminate the need for the transparent protective layer by forming the colored layer using a material having resistance to the acidic etching solution, but there is also a problem that the material that can be used for the colored layer is limited. .
The present invention has been made in view of the above circumstances, and has a PVA mode liquid crystal display device excellent in display quality, a color filter capable of manufacturing such a liquid crystal display device, and the color filter. An object is to provide a manufacturing method.

In order to achieve the above object, the present invention provides a color filter used in a liquid crystal display device of a multi-orientation division type vertical alignment mode, a transparent substrate, and a plurality of substrates arranged in a predetermined pattern on the transparent substrate. A colored colored layer and a common transparent electrode covering the colored layer are provided, and the common transparent electrode has a slit for controlling the alignment direction of liquid crystal molecules in a plurality of directions.
As another aspect of the present invention, the slit has a stripe shape having a bent portion.
As another aspect of the present invention, the slit has a width in the range of 5 to 15 μm.
As another aspect of the present invention, a configuration is provided in which a black matrix is provided at a boundary portion of each pixel.

  The present invention provides a liquid crystal display device of a multi-orientation division type vertical alignment mode, comprising a TFT substrate and a color filter which are opposed to form cells having a predetermined interval, and a liquid crystal layer filled in the cells, The filter is any one of the color filters described above, and the TFT substrate includes a transparent electrode having a slit for controlling the alignment direction of liquid crystal molecules in a plurality of directions.

  The present invention relates to a method for producing a color filter for use in a liquid crystal display device of a multi-orientation division type vertical alignment mode, and a color layer formation in which a color layer of a predetermined color is formed in a predetermined pattern on the surface of a transparent substrate is repeated for a plurality of colors. Applying a photosensitive resin composition so as to cover the colored layers of a plurality of steps, exposing the photosensitive resin composition coating film through a mask, developing, and forming a slit-forming portion of a common transparent electrode Forming a resin pattern on the resin pattern; forming a common transparent electrode so as to cover the colored layers of the plurality of colors and the resin pattern; removing the resin pattern; A lift-off step for removing the common transparent electrode at the same time and forming slits in the common transparent electrode for controlling the alignment direction of the liquid crystal molecules in a plurality of directions. It was.

As another aspect of the present invention, in the pattern forming step, the cross-sectional shape of the resin pattern is set to have a reverse taper shape in which the colored layer side is narrower than the surface side.
As another aspect of the present invention, a positive photosensitive resin composition is used as the photosensitive resin composition in the pattern forming step, and the resin pattern is exposed and removed in the lift-off step. Alternatively, in the pattern forming step, a negative photosensitive resin composition containing a polymerization initiator is used as the photosensitive resin composition, and in the lift-off step, the resin pattern is removed using an alkaline aqueous solution. The configuration.
As another aspect of the present invention, a configuration in which a black matrix is formed on the surface of the transparent substrate before the colored layer forming step, or a black matrix at a boundary portion of each pixel after the colored layer forming step. It was set as the structure which forms.

In the present invention, a common transparent electrode having a slit for orientation control is provided on the colored layer of the color filter without interposing a transparent protective layer, thereby preventing yellowing of the screen caused by the conventional transparent protective layer. A liquid crystal display device of a multi-orientation division type vertical alignment (PVA) mode using this color filter can have a wide viewing angle, high brightness, and a display screen with good color purity.
In the color filter manufacturing method of the present invention, since the common transparent electrode having the alignment control slit is formed in the lift-off process, an etching process using an acidic etchant becomes unnecessary, and the number of processes can be reduced. In addition, a wide range of materials can be selected for the color layer to be used, and the produced color filter has a wide viewing angle of the display screen, high brightness, and good color purity. ) Mode liquid crystal display device.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the drawings.
[Color filter]
FIG. 1 is a partial plan view showing an embodiment of a color filter for a liquid crystal display device of the present invention, FIG. 2 is an enlarged longitudinal sectional view taken along line AA of FIG. 1, and FIG. It is an expanded longitudinal cross-sectional view in the BB line. 1 to 3, the color filter 1 of the present invention includes a transparent substrate 2, a black matrix 3 and a colored layer 4 formed on the transparent substrate 2, and covers the black matrix 3 and the colored layer 4. The common transparent electrode 5 has a slit 6 for controlling the alignment direction of the liquid crystal molecules of the liquid crystal layer in a plurality of directions, and the alignment film 7 covers the common transparent electrode 5. have.

As the transparent substrate 2 constituting the color filter 1 of the present invention, an inflexible transparent rigid material such as quartz glass, pyrex glass and synthetic quartz plate, a transparent resin film, an optical resin plate, etc. A transparent flexible material having flexibility can be used. Among them, 1737 glass manufactured by Corning, in particular, is a material having a small coefficient of thermal expansion, excellent in dimensional stability and workability in high-temperature heat treatment, and is an alkali-free glass containing no alkali component in the glass. Suitable for color filters for color liquid crystal display devices.
The colored layer 4 constituting the color filter 1 has a red pattern 4R, a green pattern 4G, and a blue pattern 4B arranged in a stripe pattern. The black matrix 3 is a pattern 4R of each color of the colored layer 4. , 4G, and 4B (one pixel is a region surrounded by a thick line in FIG. 1) and outside the colored layer 4 formation region.

The black matrix 3 is formed by forming a metal thin film such as chromium having a thickness of about 1000 to 2000 mm by sputtering, vacuum deposition or the like, and patterning this thin film, and contains light-shielding particles such as carbon fine particles. A polyimide resin, acrylic resin, epoxy resin, or other resin layer is formed and patterned, and a photosensitive resin layer containing light-shielding particles such as carbon fine particles and metal oxide is formed. Any of those formed by patterning this photosensitive resin layer may be used. The color filter of the present invention may not have a black matrix.
The colored layer 4 in which the red pattern 4R, the green pattern 4G, and the blue pattern 4B are arranged in a stripe pattern can be formed by a pigment dispersion method using a photosensitive resin containing a desired colorant. It can be formed by a known method such as a printing method, an electrodeposition method, or a transfer method.

The common transparent electrode 5 constituting the color filter 1 is made of indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO), etc., and alloys thereof, using a sputtering method, a vacuum evaporation method, It can be formed by a general film forming method such as a CVD method. The thickness of such a common transparent electrode 5 can be about 200 to 5000 mm, for example.
The slit 6 included in the common transparent electrode 5 has a function of giving a pretilt angle to nearby liquid crystal molecules and a function of distorting electric lines of force in a desired direction, for example, in a liquid crystal display device described later, in a TFT substrate. The alignment direction of the liquid crystal molecules in the liquid crystal layer can be controlled in a plurality of directions in cooperation with the slits of the transparent pixel electrode.

The slit 6 has a stripe shape (zigzag shape) formed along each colored pattern (red pattern 4R, green pattern 4G, and blue pattern 4B) while being bent at the bent portions 6a and 6b. The bent portion 6a of the slit 6 is located at a boundary portion (on the black matrix 3) with an adjacent coloring pattern and at a boundary portion of one pixel region. Moreover, the bending part 6b is located in the approximate center part of the coloring pattern adjacent on the opposite side. In this case, the common transparent electrodes 5 divided by the stripe-shaped (zigzag-shaped) slits 6 are connected to each other outside the formation region of the colored layer 4.
The width W1 of the slit 6 can be about 5 to 15 μm, preferably about 5 to 10 μm. When the width W1 of the slit 6 is less than 5 μm, the orientation control action may be reduced. On the other hand, when the width W1 exceeds 15 μm, the non-formation area of the common transparent electrode 5 increases and the brightness of the display image is impaired. It is not preferable.
In addition, the shape of the slit 6 and the colored pattern shape are not limited to the shapes in the illustrated example.

The alignment film 7 constituting the color filter 1 can be formed of an organic compound such as soluble polyimide, polyamic acid type polyimide, and modified polyimide, and can have a thickness of about 100 to 1000 mm. Such an alignment film 7 is formed by baking after applying by various printing methods and known coating methods, but does not require alignment treatment (rubbing).
The color filter of the present invention is not limited to the above-described embodiment. For example, the slits of the common transparent electrode constituting the color filter for the liquid crystal display device of the present invention have a discontinuous stripe shape having fine discontinuous portions in addition to the continuous stripe shape as in the above embodiment. There may be. However, even if the slit has a discontinuous stripe shape, the width of the slit can be the same as the width W1 of the slit 6 described above. The color filter of the present invention may include a photo spacer (a spacer for setting the liquid crystal cell at a predetermined interval).

[Liquid Crystal Display]
Next, the liquid crystal display device of the present invention will be described.
FIG. 4 is a schematic partial sectional view showing an embodiment of the liquid crystal display device of the present invention. In FIG. 4, the liquid crystal display device 11 has the color filter 21 of the present invention and the TFT substrate 31 facing each other at a predetermined interval, the peripheral portion is sealed with a seal member (not shown), and the liquid crystal layer 12 is formed in the gap portion. A transmissive liquid crystal display device in a patterned-domain vertical alignment (PVA) mode. A polarizing plate (not shown) is disposed outside the color filter 21 and the TFT substrate 31.

The color filter 21 of the present invention constituting the liquid crystal display device 11 of the present invention includes a transparent substrate 22, a black matrix 23 and a colored layer 24 formed on the transparent substrate 22, and the black matrix 23 and the colored layer 24. A common transparent electrode 25 having a slit 26 for controlling the alignment direction of the liquid crystal molecules in the liquid crystal layer in a plurality of directions is provided, and an alignment film 27 is provided so as to cover the common transparent electrode 25.
In the colored layer 24, a red pattern 24R, a green pattern 24G, and a blue pattern 24B are arranged in a stripe pattern. The slit 26 has a stripe shape (zigzag shape) formed along each colored pattern (red pattern 24R, green pattern 24G, blue pattern 24B) while being bent at the bent portion. The color filter 21 of the present invention that constitutes the liquid crystal display device 11 is the same as the color filter 1 of the present invention described above, and a description thereof is omitted here.

The TFT substrate 31 constituting the liquid crystal display device 11 of the present invention includes a thin film transistor (TFT) 33 for driving liquid crystal and a transparent pixel electrode 34 on a transparent substrate 32, and a slit 35 is formed in the transparent pixel electrode 34. An alignment film 36 is formed so as to cover the transparent pixel electrode 34.
The TFT substrate 31 constituting the liquid crystal display device 11 of the present invention includes a gate line group (not shown) for opening and closing a thin film transistor (TFT) 33, a signal line group (not shown) for supplying a video signal, and a color. A voltage supply line (not shown) to the common transparent electrode 25 of the filter 21 is disposed. These lead wires are usually made of a metal such as aluminum formed in a lump in the manufacturing process of the thin film transistor (TFT) 33.

  As the transparent substrate 32 constituting the TFT substrate 31, the same substrate as the transparent substrate 22 of the color filter 21 described above (listed as the transparent substrate 2 of the color filter 1) can be used. Moreover, the transparent pixel electrode 34 provided with the slit 35 is sputtered through a mask provided with a slit pattern using indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO), or an alloy thereof. The film can be formed by a general film forming method such as a method, a vacuum evaporation method, or a CVD method. Alternatively, it can be formed by combining a known photolithography technique and an etching technique.

As shown in FIG. 5, the slits 35 formed in the transparent pixel electrode 34 are formed at a pitch shifted by a half pitch with respect to the arrangement pitch of the slits 26 of the color filter 21. The shape of the slit 35 shown in FIG. 5 is a stripe shape (zigzag shape) having a bent portion corresponding to the shape of the slit 26. In addition, the shape of the slit 26 and the slit 35 is not limited to the shape of the example of illustration, The number of bending parts etc. can be set suitably. Moreover, the slit 26 and the slit 35 may have a discontinuous stripe shape (zigzag shape) having a bent portion.
Further, the alignment film 36 constituting the TFT substrate 31 is soluble polyimide, polyamic acid type polyimide, modified polyimide, etc., like the alignment film 27 constituting the color filter 21 (the alignment film 7 constituting the color filter 1). The thickness of the organic compound can be about 100 to 1000 mm. Such an alignment film 36 is formed by applying various printing methods or known coating methods and then baking, but does not require alignment treatment (rubbing).

[Color filter manufacturing method]
Next, the manufacturing method of the color filter of this invention is demonstrated.
6 to 7 are process diagrams (cross-sectional views corresponding to FIG. 2) for explaining an embodiment of the method for producing the color filter of the present invention, taking the above-described color filter 1 of the present invention as an example.
In the method for producing a color filter of the present invention, first, in the colored layer forming step, the black matrix 3 is formed on the surface 2a of the transparent substrate 2 (FIG. 6A), and the red pattern 4R is formed in a stripe pattern. Then, the same operation is repeated to form the green pattern 4G and the blue pattern 4B with a predetermined pixel pattern, thereby forming the colored layer 4 (FIG. 6B).

  The black matrix 3 can be formed, for example, by forming a metal thin film of chromium or the like having a thickness of about 1000 to 2000 mm by sputtering or vacuum deposition and patterning the thin film. Alternatively, the black matrix 3 may be formed by forming a resin layer such as a polyimide resin, an acrylic resin, or an epoxy resin containing light-shielding particles such as carbon fine particles, and patterning the resin layer. Further, the black matrix 3 can be formed by forming a photosensitive resin layer containing light-shielding particles such as carbon fine particles and metal oxide, and patterning the photosensitive resin layer.

The red pattern 4R, the green pattern 4G, and the blue pattern 4B constituting the colored layer 4 can be formed by, for example, a pigment dispersion method using a photosensitive resin containing a desired colorant, and further, printing method, It can be formed by a known method such as a deposition method or a transfer method. The order of forming the colored patterns 4R, 4G, 4B is not limited to the above example.
Before the next pattern formation step, a planarizing layer may be provided on the colored layer 4 in order to planarize the colored layer 4 composed of the colored patterns 4R, 4G, 4B.

  Next, in the pattern forming step, a photosensitive resin composition is applied so as to cover the colored layers 4 (colored patterns 4R, 4G, 4B) of multiple colors, and the photosensitive resin composition coating film is exposed through a mask. Then, development is performed to form a resin pattern 8 in the slit formation scheduled portion of the common transparent electrode (FIG. 6C). In the example of the color filter 1, the slit formation scheduled portion is a stripe-shaped (zigzag) portion that is formed along each colored pattern (red pattern 4R, green pattern 4G, and blue pattern 4B) while being bent at a bent portion. It is. The resin pattern 8 to be formed preferably has a reverse taper shape in which the cross-sectional shape is narrower on the colored layer side 8a than on the surface side 8b. The width (maximum width) of the resin pattern 8 determines the width of the slit 6 formed in the common transparent electrode 5, and is set in the range of, for example, 5 to 15 μm, preferably 5 to 10 μm. Can do.

  When a positive photosensitive resin composition is used as the photosensitive resin composition for forming the resin pattern 8, the photosensitive resin composition is coated using a mask having a light-shielding portion corresponding to the resin pattern 8. By exposing and developing the film, it is possible to form a resin pattern having a reverse tapered shape in cross section. Examples of the positive photosensitive resin composition used include commercially available positive photosensitive resin compositions such as OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.

  Moreover, when using a negative photosensitive resin composition for formation of the resin pattern 8, a well-known negative photosensitive resin composition can be used. For example, as an acrylic negative photosensitive resin composition, at least a photopolymerization initiator that generates a radical component by ultraviolet irradiation and a polymerization reaction caused by the generated radical having an acrylic group of C = C in the molecule. And a functional group that can dissolve the unexposed portion by subsequent development (for example, a component having an acidic group in the case of development with an alkaline solution) can be used. Thus, when a negative photosensitive resin composition containing a polymerization initiator is used and the photosensitive resin composition coating film is exposed through a mask having a translucent portion corresponding to the resin pattern 8, Since the amount of exposure gradually decreases in the depth direction and the degree of the polymerization reaction decreases, the resin pattern 8 having a reverse tapered shape in cross section is formed by subsequent development.

Among the above-mentioned components having an acrylic group, examples of relatively low molecular weight polyfunctional acrylic molecules include dipentaerythritol hexaacrylate (DPHA), dipentaerythritol pentaacrylate (DPPA), and tetramethylpentatriacrylate (TMPTA). Can be mentioned. Moreover, as a high molecular weight polyfunctional acrylic molecule, the polymer etc. which introduce | transduced the acrylic group through the spacer to the one part carboxylic acid group part of the styrene-acrylic acid-benzyl methacrylate copolymer are mentioned.
Next, in the electrode formation step, the common transparent electrode 5 is formed so as to cover the colored layer 4 composed of a plurality of colored patterns 4R, 4G, and 4B and the resin pattern 8 (FIG. 7A). The common transparent electrode 5 is formed by a film forming method such as a sputtering method or a vacuum evaporation method using indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO), or an alloy thereof. be able to.

  Next, in the lift-off process, by removing the resin pattern 8, the common transparent electrode 5 on the resin pattern 8 is also removed at the same time, and the slit 6 for controlling the alignment direction of the liquid crystal molecules in the liquid crystal layer in a plurality of directions. A common transparent electrode 5 having the following structure is formed (FIG. 7B). When the resin pattern 8 is formed using a positive photosensitive resin composition, the resin pattern 8 can be removed by exposing the resin pattern 8 and then washing it. Moreover, when a negative photosensitive resin composition is used for formation of the resin pattern 8, the resin pattern 8 can be removed using alkaline aqueous solution.

Next, an alignment film 7 is formed so as to cover the common transparent electrode 5 (FIG. 7C). The alignment film 7 can be formed, for example, by applying an organic compound such as soluble polyimide, polyamic acid type polyimide, or modified polyimide by various printing methods or known coating methods, and then baking. The thickness of the alignment film 7 can be about 100 to 1000 mm. The alignment film 7 does not require alignment processing (rubbing).
In the method for producing a color filter of the present invention, it is not necessary to use an acidic etching solution, and the common transparent electrode 5 having the alignment control slit 6 can be formed without damaging the colored layer. In addition, the etching process is unnecessary, the number of processes can be reduced, and the range of materials for the colored layer that can be used is wide.

Next, an Example is shown and this invention is demonstrated further in detail.
[Example 1]
As a transparent substrate for a color filter, a glass substrate (Corning 1737 glass) having a size of 300 mm × 400 mm and a thickness of 0.7 mm was prepared. After this substrate was washed according to a conventional method, a chromium thin film (thickness 2000 mm) was formed on the entire surface of one side of the substrate by sputtering. A positive-type photosensitive resist (OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied onto the chromium thin film, and exposed and developed through a predetermined mask to form a resist pattern. Next, using this resist pattern as a mask, the chromium thin film was etched with an aqueous solution of ceric ammonium nitrate and perchloric acid to form a black matrix having a line width of 20 μm and a pitch of 100 μm.

Next, a negative photosensitive resin composition for a red pattern, a negative photosensitive resin composition for a green pattern, and a negative photosensitive resin composition for a blue pattern having the following compositions were prepared.
(Negative photosensitive resin composition for red pattern)
・ Red pigment: 4.8 parts by weight (Chromophthalic Red A2B, manufactured by Ciba Specialty Chemicals)
・ Yellow pigment: 1.2 parts by weight (PASFOL Yellow D1819, manufactured by BASF)
-Dispersant (Disperbic 161 manufactured by Big Chemie) ... 3.0 parts by weight-Monomer (SR399, manufactured by Sartomer) ... 4.0 parts by weight-Polymer I ... 5.0 parts by weight-Initiator ... 1.4 parts by weight ( (Irgacure 907, manufactured by Ciba Specialty Chemicals)
Initiator: 0.6 parts by weight (2,2′-bis (o-chlorophenyl) -4,5,4 ′, 5′-
Tetraphenyl-1,2'-biimidazole)
・ Solvent: 80.0 parts by weight (propylene glycol monomethyl ether acetate)

(Negative photosensitive resin composition for green pattern)
Green pigment: 4.2 parts by weight (Avisia Monastral Green 9Y-C)
・ Yellow pigment: 1.8 parts by weight (manufactured by BASF Paliotor Yellow D1819)
-Dispersant (Disperbic 161 manufactured by Big Chemie) ... 3.0 parts by weight-Monomer (SR399, manufactured by Sartomer) ... 4.0 parts by weight-Polymer I ... 5.0 parts by weight-Initiator ... 1.4 parts by weight ( (Irgacure 907, manufactured by Ciba Specialty Chemicals)
Initiator: 0.6 parts by weight (2,2′-bis (o-chlorophenyl) -4,5,4 ′, 5′-
Tetraphenyl-1,2'-biimidazole)
・ Solvent: 80.0 parts by weight (propylene glycol monomethyl ether acetate)

(Negative photosensitive resin composition for blue pattern)
・ Blue pigment: 6.0 parts by weight (Heliogen Blue L6700F manufactured by BASF)
Pigment derivative (Solsperse 5000 manufactured by Avicia) ... 0.6 parts by weight Dispersant (Disperbic 161 manufactured by Big Chemie) ... 2.4 parts by weight Monomer (SR399 manufactured by Sartomer) 4.0 parts by weight Polymer I … 5.0 parts by weight • Initiator… 1.4 parts by weight (Irgacure 907 manufactured by Ciba Specialty Chemicals)
Initiator: 0.6 parts by weight (2,2′-bis (o-chlorophenyl) -4,5,4 ′, 5′-
Tetraphenyl-1,2'-biimidazole)
・ Solvent: 80.0 parts by weight (propylene glycol monomethyl ether acetate)

  The polymer I is based on 100 mol% of a copolymer of benzyl methacrylate: styrene: acrylic acid: 2-hydroxyethyl methacrylate = 15.6: 37.0: 30.5: 16.9 (molar ratio). 2-methacryloyloxyethyl isocyanate was added at 16.9 mol%, and the weight average molecular weight was 42500.

Next, a negative photosensitive resin composition for red pattern is applied by spin coating so as to cover the black matrix on the glass substrate, exposed and developed through a photomask for red pattern, and the red pattern is formed. Formed. This red pattern had a stripe shape in which pixels (rectangular shape of 100 μm × 300 μm) as shown in FIG. 1 were continuous.
Then, the green pattern and the blue pattern were formed by the same operation using the negative photosensitive resin composition for the green pattern and the negative photosensitive resin composition for the blue pattern. Thus, a colored layer in which the red pattern, the green pattern, and the blue pattern are arranged in a stripe pattern as shown in FIG. 1 was formed. (End of colored layer formation process)

Next, a positive photosensitive resin composition (OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied by a spin coating method so as to cover the black matrix and the colored layer, and the following conditions are applied through a mask having the following specifications. And then developed with an aqueous potassium hydroxide solution. As a result, a resin pattern having a stripe shape (zigzag shape) having bent portions in the same direction at a pitch of 300 μm and along each colored pattern (red pattern, green pattern, blue pattern) was formed. The cross-sectional shape of this resin pattern was an inversely tapered shape with the colored layer side being 8 μm and the surface side being 10 μm. (End of pattern formation process)
(Mask specifications)
-Light-shielding part: 150m pitch and reverse bending
Stripe shape (zigzag shape)
-Width of stripe shape of light shielding part: 12μm
・ An angle of the stripe shape of the bent part: 90 °
(Exposure conditions)
・ Exposure: 60 mJ / cm ²
・ Exposure gap: 75μm

Next, a common transparent electrode (thickness 1500 mm) made of indium tin oxide (ITO) was formed by sputtering so as to cover the black matrix, the colored layer, and the resin pattern. (End of electrode formation process)
Next, the resin pattern formation surface side was exposed on the following conditions, and alkaline aqueous solution washing | cleaning and water washing were performed. As a result, the resin pattern was removed, and at the same time, the ITO film on the resin pattern was also removed to form a common transparent electrode having an alignment control slit (line width: 10 μm). (End of lift-off process)
(Exposure conditions)
・ Exposure: 300 mJ / cm ²
・ Exposure area: Full exposure

Next, a coating for alignment film (SE-5300 manufactured by Nissan Chemical Co., Ltd.) is applied by spin coating so as to cover the common transparent electrode, and subjected to a baking treatment at 220 ° C. for 60 minutes to obtain a thickness (common transparent). An alignment film having a thickness of 200 mm on the electrode was formed to obtain the color filter of the present invention.
On the other hand, a 300 mm × 400 mm glass substrate (Corning 1737 glass) was prepared as a transparent substrate for the TFT substrate. After this substrate was washed according to a conventional method, indium tin oxide (ITO) was formed to a thickness of 1500 mm by sputtering on the entire surface of one side of the substrate to form a transparent electrode.

  Next, a positive type photosensitive resist (OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied on the transparent electrode, and exposed and developed through a predetermined mask to form a resist pattern. Next, using this resist pattern as a mask, the transparent electrode was etched to form slits. The slit had a line width of 10 μm, and the shape and the arrangement pitch were the same as the slit shape and the arrangement pitch of the common transparent electrode. Thereafter, in the same manner as in the production of the color filter described above, an alignment film having a thickness of 200 mm was formed on the transparent electrode provided with the slits to obtain a TFT substrate.

The actual TFT substrate includes a transparent pixel electrode patterned in a pixel shape on a substrate including a thin film transistor (TFT) for driving a liquid crystal. In this embodiment, the TFT is omitted for simplification. A slit was formed in a transparent electrode that was not patterned into a pixel shape to obtain a TFT substrate.
Next, the color filter and the TFT substrate were bonded together with a 5 μm gap so that the alignment film forming surface side was opposed. At this time, the slit for controlling the orientation of the color filter and the slit of the TFT substrate were set to be shifted by a half pitch as shown in FIG. Next, liquid crystal was injected into the cell using a vacuum injection method, the injection port was sealed with an ultraviolet curable resin, an annealing treatment was performed, and the flow alignment effect was cancelled. Thereby, a liquid crystal display device for evaluation was produced.

[Example 2]
A liquid crystal display device for evaluation was produced in the same manner as in Example 1 except that in the pattern forming step, a resin pattern was formed using a negative photosensitive resin composition having the following composition.
(Negative photosensitive resin composition)
・ Methyl methacrylate-styrene-acrylic acid copolymer: 42 parts by weight ・ Epicoat 180S70 (Mitsubishi Yuka Shell Co., Ltd.): 18 parts by weight ・ Dipentaerythritol pentaacrylate: 32 parts by weight: Initiator: 8 parts by weight (Irgacure 907 manufactured by Ciba Specialty Chemicals)
・ Solvent: 300 parts by weight (propylene glycol monomethyl ether acetate)

  The formed resin pattern has a bent portion in the same direction at a pitch of 300 μm, and has a stripe shape (zigzag shape) along each colored pattern (red pattern, green pattern, blue pattern). The shape was a reverse taper shape with the colored layer side being 8 μm and the surface side being 10 μm. In the lift-off process, the resin pattern was peeled off using an aqueous potassium hydroxide solution. The slits of the common transparent electrode thus formed had a stripe shape (zigzag shape) (width 10 μm) corresponding to the resin pattern.

[Comparative example]
First, in the same manner as in Example 1, a black matrix and a colored layer were formed on a glass substrate.
Next, a transparent protective layer coating solution (SS6908, manufactured by JSR Corporation) is applied by a spin coating method so as to cover the black matrix and the colored layer, and is subjected to a curing treatment at 230 ° C. for 30 minutes. (Thickness 1.5 μm) was formed.

Next, a common transparent electrode (thickness 1500 mm) made of indium tin oxide (ITO) was formed on the transparent protective layer by a sputtering method.
Next, a positive photosensitive resist (OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied on the common transparent electrode, and exposed and developed through a predetermined mask to form a resist pattern. Next, the ITO film was etched using this resist pattern as a mask, and a slit was formed so as to be positioned on each pixel. The slit of the common transparent electrode formed in this way has a bent portion in the same direction at a pitch of 300 μm, has a stripe shape (zigzag shape) along each colored pattern (red pattern, green pattern, blue pattern), and width Was 10 μm.
Thereafter, an alignment film was formed in the same manner as in Example 1 to obtain a color filter.
A liquid crystal display device for evaluation was produced in the same manner as in Example 1 using the above color filter and the same TFT substrate as in Example 1.

[Evaluation]
The liquid crystal display devices (Examples 1 and 2 and Comparative Examples) manufactured as described above are displayed based on the brightness when they are placed on the backlight and white / black display is performed by ON / OFF of the voltage. The grade was evaluated. As a result, in the liquid crystal display devices of Examples 1 and 2, the display was good, but in the liquid crystal display device of the comparative example, the display was slightly yellowish.

  It can be used for a liquid crystal display device of a multi-alignment division type vertical alignment mode.

It is a partial top view which shows one Embodiment of the color filter for liquid crystal display devices of this invention. It is an expanded longitudinal cross-sectional view in the AA line of FIG. It is an expanded longitudinal cross-sectional view in the BB line of FIG. 1 is a schematic partial cross-sectional view showing an embodiment of a liquid crystal display device of the present invention. It is a figure for showing the positional relationship of the slit for orientation control in the liquid crystal display device of the present invention, and the slit of a transparent pixel electrode. It is process drawing for demonstrating one Embodiment of the manufacturing method of the color filter of this invention. It is process drawing for demonstrating one Embodiment of the manufacturing method of the color filter of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1 '... Color filter 2 ... Transparent substrate 3 ... Black matrix 4 ... Colored layer 4R, 4G, 4B ... Colored pattern 5 ... Common transparent electrode 6 ... Slit 7 ... Orientation film 8 ... Resin pattern 11 ... Liquid crystal display device 12 ... Liquid crystal layer 21 ... Color filter 22 ... Transparent substrate 23 ... Black matrix 24 ... Colored layer 24R, 24G, 24B ... Colored pattern 25 ... Common transparent electrode 26 ... Slit 27 ... Alignment film 31 ... TFT substrate 32 ... Transparent substrate 33 ... TFT
34 ... Transparent pixel electrode 35 ... Slit 36 ... Alignment film

Claims (11)

In a color filter used in a liquid crystal display device of a multi-alignment division type vertical alignment mode
A transparent substrate, a plurality of colored layers arranged in a predetermined pattern on the transparent substrate, and a common transparent electrode covering the colored layer, the common transparent electrode having a plurality of orientation directions of liquid crystal molecules A color filter for a liquid crystal display device, comprising a slit for controlling the liquid crystal display.   The color filter for a liquid crystal display device according to claim 1, wherein the slit has a stripe shape having a bent portion.   The color filter for a liquid crystal display device according to claim 1 or 2, wherein a width of the slit is in a range of 5 to 15 µm.   The color filter for a liquid crystal display device according to any one of claims 1 to 3, wherein a black matrix is provided at a boundary portion of each pixel. In the liquid crystal display device of the multi-alignment division type vertical alignment mode,
5. The color filter according to claim 1, comprising a TFT substrate and a color filter that are opposed to each other so as to form cells at a predetermined interval, and a liquid crystal layer filled in the cell, wherein the color filter is a color filter according to claim 1. The TFT substrate includes a transparent electrode having a slit for controlling the alignment direction of liquid crystal molecules in a plurality of directions. In the manufacturing method of the color filter used for the liquid crystal display device of a multiple alignment division type vertical alignment mode
A colored layer forming step for repeating the operation of forming a colored layer of a predetermined color in a predetermined pattern on the surface of the transparent substrate for a plurality of colors,
A photosensitive resin composition is applied so as to cover the colored layers of a plurality of colors, the photosensitive resin composition coating film is exposed through a mask, developed, and a resin pattern is formed on a slit formation scheduled portion of the common transparent electrode. Forming a pattern, and
An electrode forming step of forming a common transparent electrode so as to cover the colored layers of a plurality of colors and the resin pattern;
A lift-off process for removing the resin pattern and simultaneously removing the common transparent electrode on the resin pattern and forming slits in the common transparent electrode for controlling the alignment direction of the liquid crystal molecules in a plurality of directions. A method for producing a color filter characterized by the above.   The method for producing a color filter according to claim 6, wherein in the pattern forming step, the cross-sectional shape of the resin pattern is an inversely tapered shape whose color layer side is narrower than the surface side.   The positive pattern type photosensitive resin composition is used as the photosensitive resin composition in the pattern forming step, and the resin pattern is exposed and removed in the lift-off step. The manufacturing method of the color filter of description.   In the pattern forming step, a negative photosensitive resin composition containing a polymerization initiator is used as the photosensitive resin composition, and in the lift-off step, the resin pattern is removed using an alkaline aqueous solution. The manufacturing method of the color filter of Claim 6 or Claim 7.   The method for producing a color filter according to any one of claims 6 to 9, wherein a black matrix is formed on a surface of the transparent substrate before the colored layer forming step.   The method for manufacturing a color filter according to claim 6, wherein a black matrix is formed at a boundary portion of each pixel after the colored layer forming step.

Images