JP5304170B2 - COLOR FILTER, COLOR FILTER MANUFACTURING METHOD, AND LIQUID CRYSTAL DISPLAY DEVICE USING THE SAME - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color filter for compensating a defect without increasing processes in compensating the defect included in a spacer formed by stacking a colored layer, and to provide a method of manufacturing the color filter. <P>SOLUTION: The spacer 4 is formed by stacking a colored layer of at least two of three primary colors, a transparent electrode film 5 and an insulating layer 17 also serving for adjustment of the height of the spacer are disposed on the spacer, and the transparent electrode film on the colored layer has a slit 6 for regulating the alignment of liquid crystal. The insulating layer is made of the same material as that of an etching protection film used for forming the slit in the transparent electrode film. The method of manufacturing the color filter includes a process of forming the etching protection film 15 having an insulating layer and an opening by exposure and development to a photoresist layer 10, forming the slit 6, and peeling the etching protection film. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a color filter for a liquid crystal display device, and in particular, a color filter capable of compensating for a defect without increasing the number of steps when compensating for the defect of a spacer formed by laminating colored layers. The present invention also relates to a method for manufacturing a color filter, and a liquid crystal display device using the color filter.

  FIG. 1 is a cross-sectional view of an example of a color filter for a liquid crystal display device in which a spacer formed by laminating colored layers is provided, and a transparent electrode film on the colored layer is provided with a slit for regulating the alignment of liquid crystal. FIG. 1 shows an enlarged view of a space between a red colored layer and a green colored layer of a color filter in which the colored layers are formed in the order of red, green, and blue.

  As shown in FIG. 1, this color filter (CF1) is formed on a transparent substrate (1) on a black matrix layer (2), three colored layers (3R, 3G, (3B)), a spacer (4), Transparent electrode films (5) are sequentially formed. The spacer (4) is formed by laminating a red colored layer (3R '), a green colored layer (3G'), and a blue colored layer (3B '). The slit (6) regulates the orientation of the liquid crystal, and is formed by photoetching the transparent electrode film (5).

  The transparent electrode film (5) is once provided on the entire surface of the transparent substrate (1) on which the black matrix layer (2), the three colored layers (3R, 3G, 3B) and the spacer (4) are formed. In addition, the slit (6) is formed in the transparent electrode film (5) on the three colored layers (3R, 3G, 3B), and the transparent electrode films (on the upper and side portions of the spacer (4) ( 5) is removed during the photoetching to prevent short circuit with the counter substrate (not shown).

Conventionally, a spacer that holds a gap between substrates of a liquid crystal panel has a suitable elastic property as a spacer, and uses a material that does not contain impurities that are eluted in liquid crystal, and forms a three-color colored layer at a desired height. A spacer is provided in a single layer on the transparent substrate (1) on which the black matrix layer (2), the three colored layers (3R, 3G, 3B) and the transparent electrode film (5) are formed. It was.
The spacer (4) shown in FIG. 1 is replaced with three colored layers (3R ′, 3G ′, 3B ′) in order to reduce the number of steps when manufacturing a color filter.

  Therefore, the spacer (4) formed by laminating the colored layers as shown in FIG. 1 has a drawback that the height cannot be arbitrarily adjusted. As a method of adjusting the height of the spacer formed by stacking, for example, a method of changing the film thickness of the three colored layers (3R, 3G, 3B) can be given. However, when the film thickness of the three colored layers is simply changed with colored photoresists of the same material, there is a problem that the color density of the obtained three colored layers changes.

  In order to eliminate this adverse effect, that is, in order not to change the color density of the colored layer even if the thickness of the colored layer is changed, for example, the pigment concentration of the colored photoresist is changed. In other words, in order to obtain a spacer having a desired height, it is complicated to prepare a colored photoresist having a specific pigment concentration.

Moreover, the spacer formed by laminating the colored layers has a drawback that it cannot sufficiently satisfy the elastic characteristics required for the spacer.
The spacer sets a gap between the substrates, and is required to have an elastic characteristic that deforms when a load is applied to the panel and restores when the load is removed. Further, there is a demand for a characteristic that deforms following the thermal expansion and contraction of liquid crystal depending on temperature.

  If this elastic characteristic is not appropriate, all the members constituting the liquid crystal cell tend to contract under the environment where the liquid crystal display device is used, for example, at a low temperature such as −20 ° C. Among the constituent members, the contraction rate of the liquid crystal is the largest, so it tends to shrink in the direction of reducing the gap between the substrates. At this time, if the deformation of the photo spacer cannot follow the amount of change that the gap between the substrates tends to shrink, a negative pressure is generated inside the panel, resulting in the generation of vacuum bubbles (cold bubbles) in the panel. become.

  In the spacer (4) shown in FIG. 1, the three colored layers (3R ′, 3G ′, 3B ′) are in contact with the liquid crystal, and impurities (ions, pigments) from the colored layer are eluted into the liquid crystal. This easily causes alignment failure of the liquid crystal and causes display failure. When the colored layer is photocured, the side of the spacer (4) is less likely to reach the inside than the surface of the colored layer, and the photocuring is weak.

FIG. 2 is a cross-sectional view of an example of a color filter using a technique that can be easily considered as a technique for compensating for the drawbacks of a spacer formed by laminating colored layers. The transparent electrode film provided on the entire surface of the transparent substrate (1) on which the black matrix layer (2), the three colored layers (3R, 3G, (3B)) and the spacer (4) are formed as shown in FIG. As for (5), slits (6) are formed in the transparent electrode film (5) on the colored layers of three colors, and the transparent electrode films (5) on the upper and side portions of the spacer (4) are Left unremoved.
On the spacer (4), an adjustment layer (7) for arbitrarily increasing the height of the spacer via the transparent electrode film (5) is provided. This adjustment layer (7) also serves as an insulating layer for preventing a short circuit with the counter substrate.

  Certainly, according to the color filter (CF2) shown in FIG. 2, the height of the spacer can be arbitrarily adjusted to a desired height, and the elution of impurities from the colored layer is improved. However, in this color filter, as compared with the color filter (CF1) shown in FIG. 1, the number of steps for forming the adjustment layer (7) is increased.

  That is, the transparent electrode film is formed in a separate process from the formation of the three-colored colored layer at a desired height by using a material having an appropriate elastic property as a spacer and containing no impurities that are eluted in the liquid crystal. The color filter (CF2) having the spacer shown in FIG. 2 cannot be said to be superior to the one-layer spacer provided on the transparent substrate on which is formed.

Japanese Patent Application Laid-Open No. 2002-6132 discloses another technique that compensates for a defect of a spacer formed by stacking colored layers. FIG. 3 is a cross-sectional view of an example of the disclosed color filter. As shown in FIG. 3, the color filter (CF3) includes a transparent substrate (1) on which a black matrix layer (2), three colored layers (3R, 3G, (3B)), and a spacer (4) are formed. A transparent protective layer (8) is provided on the entire upper surface, and then a transparent electrode film (5) is provided on the entire upper surface of the transparent protective layer (8), followed by a transparent electrode above the three colored layers. The slit (6) is formed in the film (5), and the transparent electrode film (5) on the upper and side portions of the transparent protective layer (8) on the spacer (4) is removed.
This transparent protective layer (8) makes it possible to control the height of the spacer (4).

Certainly, according to the color filter (CF3) shown in FIG. 3, the height of the spacer can be arbitrarily adjusted to a desired height, and the elution of impurities from the colored layer is suppressed. However, in this color filter, the number of steps for forming the transparent protective layer (8) is increased compared to the color filter (CF1) shown in FIG.

That is, the transparent electrode film is formed in a separate process from the formation of the three-colored colored layer at a desired height by using a material having an appropriate elastic property as a spacer and containing no impurities that are eluted in the liquid crystal. In contrast to the single layer spacer provided on the transparent substrate on which the color filter is formed, the color filter having the spacer shown in FIG. 3 cannot be said to be advantageous.
JP 2002-6132 A JP 2001-75103 A Japanese Patent No. 3255107 Japanese Patent No. 3651874

The present invention has been made in order to solve the above-described problem, and a spacer formed by laminating a colored layer is provided, and a slit for regulating the alignment of liquid crystal is provided in the transparent electrode film on the colored layer. In a color filter for a liquid crystal display device, it is possible to compensate for a defect without increasing the step of providing an adjustment layer or the step of providing a transparent protective layer when the defect of a spacer formed by stacking colored layers is compensated. It is an object of the present invention to provide a color filter and a method for manufacturing the color filter.
It is another object of the present invention to provide a liquid crystal display device using the color filter.

The present invention relates to a color filter for a liquid crystal display device comprising a black matrix layer, three primary color layers, a spacer, and a transparent electrode film on a transparent substrate, wherein the spacer is a color layer of at least two primary colors of the three primary colors. The transparent electrode film and the insulating layer that also adjusts the height of the spacer are formed on the spacer , and the insulating layer on the spacer covers the spacer from the top to the bottom. And the insulating layer on the spacer is formed of the same material as the etching protective film used when forming the slit in the transparent electrode film, and the material is an alkali-soluble positive photosensitive resin, The transparent electrode film on the colored layers of the three primary colors is a color filter having a slit for regulating the alignment of liquid crystal.

  The present invention also provides the color filter according to the above invention, wherein the spacer is formed on a black matrix layer.

  Further, the present invention is the color filter according to the above-described invention, wherein the number of layers for stacking the three primary color layers is changed and two or more kinds of spacers having different heights are provided.

Further, the present invention is a manufacturing method for manufacturing a color filter according to any one of claims 1 to 3, at least,
1) A step of forming a photoresist layer for forming an insulating layer and an etching protective film on a transparent substrate on which a black matrix layer, three colored layers, a spacer, and a transparent electrode film are formed,
2) An etching protective film having an opening corresponding to the formation of an insulating layer and a slit by exposing and developing the photoresist layer through a photomask which is a multi-tone mask using an ITO film in a semi-transparent portion. Forming step,
3) forming a slit in the transparent electrode film by etching,
4) A step of peeling off the etching protective film on the transparent electrode film above the colored layer.

In addition, the present invention is a manufacturing method for manufacturing the color filter according to claim 3 , and has a pattern according to the number of layers to be stacked as a pattern corresponding to the formation of the three primary color layers constituting the spacer. A color filter manufacturing method using a photomask for each of the three primary colors.

In addition, the present invention is a liquid crystal display device using the color filter according to any one of claims 1 to 3 .

  The present invention relates to a color filter for a liquid crystal display device comprising a black matrix layer, three primary color layers, a spacer, and a transparent electrode film on a transparent substrate, wherein the spacer is a color layer of at least two primary colors of the three primary colors. On the spacer, and formed of the same material as the transparent electrode film and the etching protective film, and having an insulating layer that also adjusts the height of the spacer, on the colored layer of the three primary colors Since the transparent electrode film has slits that regulate the alignment of the liquid crystal, it becomes a color filter that can compensate for the defects without increasing the number of steps when compensating for the defects of the spacer formed by stacking the colored layers. .

Further, since the insulating layer on the spacer is formed so as to cover from the upper part to the lower part of the spacer, the elution of impurities from the colored layer to the liquid crystal can be prevented.
Thereby, disorder of the alignment of the liquid crystal is suppressed, the contrast of the liquid crystal display device is improved, and the display quality is improved.

  The present invention also includes 1) a step of forming a photoresist layer for forming an insulating layer and an etching protective film on a transparent substrate on which a black matrix layer, a three-color colored layer, a spacer, and a transparent electrode film are formed. 2) A step of forming an etching protective film having an opening corresponding to the formation of the insulating layer and the slit by exposing and developing the photoresist layer through a photomask, and 3) slitting the transparent electrode film by the etching process. 4) The step of peeling off the etching protective film on the transparent electrode film above the colored layer is provided, so that the number of steps can be increased without making up for the disadvantages of the spacer formed by laminating the colored layer. This is a method of manufacturing a color filter that can compensate for the drawbacks.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 4 is a cross-sectional view of an embodiment of a color filter for a liquid crystal display device according to the present invention. FIG. 4 shows an enlarged view between the red colored layer and the green colored layer of the color filter in which the colored layers are formed in the order of red, green, and blue.
As shown in FIG. 4, the color filter (CF4) is formed on the transparent substrate (1) on the black matrix layer (2), the three colored layers (3R, 3G, (3B)), the spacer (4), Transparent electrode films (5) are sequentially formed. The spacer (4) is formed by laminating a red colored layer (3R ′), a green colored layer (3G ′), and a blue colored layer (3B ′). The slit (6) regulates the orientation of the liquid crystal, and is formed by photoetching the transparent electrode film (5).

  The transparent electrode film (5) is once provided on the entire surface of the transparent substrate (1) on which the black matrix layer (2), the three colored layers (3R, 3G, 3B) and the spacer (4) are formed. In addition, the slit (6) is formed in the transparent electrode film (5) on the three colored layers (3R, 3G, 3B), and the transparent electrode film (5) is formed on the spacer (4). Is left.

  An insulating layer (17) is provided on the transparent electrode film (5) above the spacer (4). The insulating layer (17) is a layer for adjusting the height of the spacer, and is provided to prevent a short circuit with the counter substrate. This insulating layer (17) is formed of the same material as the etching protective film used when the slit (6) is formed in the transparent electrode film (5) on the three colored layers (3R, 3G, 3B). It is.

  The black matrix layer (2) has a thickness (t1) of about 0.5 to 3 μm and a width (W) of about 3 to 30 μm. The thickness (t2) of the red colored layer (3R), the green colored layer (3G), and the blue colored layer (3B) is about 0.5 to 3 μm. The thickness of the red colored layer (3R ′), the green colored layer (3G ′), and the blue colored layer (3B ′) constituting the spacer (4) is the thickness of the three colored layers (3R, 3G, 3B). Is approximately 1.8 μm, the red colored layer (3R ′) formed on the black matrix layer (2) has a thickness of about 0.95 μm, and the green colored layer (3G ′) has a thickness of 0. The thickness (t3) of the blue colored layer (3B ′) is about 0.88 μm and tends to be formed thinly in order.

  The slit (6) can be circular, oval, square, stripe, etc. For example, a small panel such as a cellular phone is often provided with a circular slit having a size of about 8 to 15 μm, and a small panel such as a liquid crystal television is often provided with a striped slit of about 10 to 30 μm. The former emphasizes visibility from the front rather than diagonal visibility, and the latter often emphasizes visibility when viewed from an angle, but this is limited because it depends on the panel design and usage environment. Absent.

The thickness (t4) of the insulating layer (17) is set by an amount for adjusting the height of the spacer, and is about 0.5 to 2 μm. In consideration of optical formation by the photolithographic method, a more preferable thickness of the insulating layer (17) is 1 to 2 μm.
Further, the gap between the substrates of the panel as the liquid crystal display device is in the range applicable to the present invention of 2 to 5 μm.

FIGS. 5A to 5D are cross-sectional views for explaining an outline of an example of a method for forming the insulating layer (17) in the present invention. FIG. 5A shows the stage of exposure of the photoresist layer (10) through the photomask (20).
As shown in FIG. 5 (a), a black matrix layer (2), a three-color colored layer (3R, 3G, (3B)), a spacer (4), and a transparent electrode film (5) are sequentially formed. A photoresist layer (10) is formed on the substrate (1).

This photoresist layer (10) is a photoresist layer for forming an insulating layer (17) and an etching protective film (15). The insulating layer (17) and the etching protective film (15) are formed using a photoresist layer (10) made of the same material. FIG. 5A shows an example in which a positive photoresist is used as a photoresist for forming the insulating layer (17) and the etching protective film (15).
The thickness of the photoresist layer (10) is a thickness required when adjusting the height of the spacer (4) on the spacer (4), and is usually an etching protective film (15 suitable as an etching protective film). ) Thicker than

  In FIG. 5A, a proximity exposure gap (G) is provided above the photoresist layer (10), and a photomask (20) is disposed with its film surface facing the photoresist layer (10). ing. As shown in FIG. 5A, the photomask (20) is provided with a light shielding portion (21) corresponding to the formation of the insulating layer (17), and a half corresponding to the formation of the etching protective film (15). The multi-tone mask is provided with a translucent part (22) and a translucent part (23) corresponding to the formation of the opening (16) of the etching protective film (15).

As shown in FIG. 5A, the photoresist layer (10) is exposed (E) through a photomask (20), and the thickness is lower than the thickness (t4) of the insulating layer (17) ( t5) An etching protective film (15) is formed simultaneously with the formation of the insulating layer (17).
In FIG. 5A, a state in which the development processing has already been completed and the etching protective film (15) is formed is shown by a dotted line.
The etching protective film (15) is peeled off after the slit (6) is formed in the transparent electrode film (5) by etching, but the insulating layer (17) remains, so the thickness of the etching protective film (15) is reduced. In order to make the peeling easier, the thinner one is preferable.

The semi-transparent portion (22) of the photomask (20) shown in FIG. 5A is an example in which a semi-transparent film is used. A semi-transparent film is a thin film that attenuates ultraviolet rays, for example, a halftone film made of a metal oxide film such as ITO, or a chromium film formed when manufacturing a photomask, and further thinned by photoetching. For example, a halftone film.
For example, when the photoresist layer (10) is properly exposed through the light transmitting portion (23) so that the opening (16) of the etching protective film (15) is well formed. Then, the transmittance of the semi-transparent film is set so that the exposure to the etching protective film (15) through the semi-transparent portion (22) is also appropriately performed.

  FIG. 5B shows a stage where exposure development processing is performed. As shown in FIG. 5B, by using a multi-tone mask as the photomask (20), the thickness (t4) of the insulating layer (17) is maintained, and the thickness of the etching protective film (15). (T5) has an appropriate thickness as the etching protective film (15), and the opening (16) of the etching protective film (15) is well formed.

  FIG. 5 (c) shows the stage where the transparent electrode film (5) is etched, and FIG. 5 (d) shows the stage where the etching protective film (15) is peeled off. It is. As shown in FIGS. 5 (c) and 5 (d), the transparent electrode film (5) is etched with the slit (6) well formed and the thickness (t4) of the insulating layer (17) maintained. The protective film (15) is peeled off.

  5 shows a positive photoresist as an example of the photoresist used for forming the insulating layer (17) and the etching protective film (15). However, the insulating layer (17) and the etching protective film ( As the photoresist as the same material used for the formation of 15), a negative photoresist can also be suitably used.

  Moreover, in said one Example, the red colored layer (3R '), the green colored layer (3G'), and the blue colored layer (3B ') constituting the spacer (4) are the three colored layers (3R, It is formed simultaneously with the formation of 3G and 3B), but is an independent form as a pattern. The red colored layer (3R ′), the green colored layer (3G ′), and the blue colored layer (3B ′) constituting the spacer (4) are not limited to independent forms as a pattern. For example, the red colored layer (3R) and the red colored layer (3R ′) may be continuous, that is, the red colored layer (3R) may be extended to become the red colored layer (3R ′).

  In the above embodiment, the bottom areas of the red colored layer (3R ′), the green colored layer (3G ′), and the blue colored layer (3B ′) are the same, but from the lower layer to the upper layer. When the bottom area of the colored layer is reduced, there is an effect of preventing misalignment in actual work.

The shape of the spacer, that is, the shape of the cross section when the spacer is cut along a plane parallel to the substrate is not particularly limited, but a circle, an ellipse, a polygon with rounded corners, a rectangle, a rectangle, and the like are preferable. In the case where the spacer is formed by lamination, the shape of the spacer is not particularly limited, but a circle, an ellipse, a polygon with rounded corners, a quadrangle, a rectangle, or the like is preferable, and these are arbitrarily laminated to form the spacer. It's okay.
The spacer may be formed in the above shape on the entire black matrix layer between the colored layers, but in order to ensure elasticity in the process of bonding the color filter substrate and the TFT substrate, the red colored layer, the green colored layer In addition, it is desirable to form one per colored layer including a blue colored layer.

Table 1 sets the thicknesses of the black matrix layer (2), the three color layers (3R, 3G, (3B)), and the insulating layer (17) constituting the color filter (CF4) shown in FIG. This shows the result of a specific attempt to adjust the height of the spacer.
As shown in Table 1, when the insulating layer (17) is provided as compared with the condition 1, as shown in the conditions 2 to 4, the entire height of the spacer includes the spacer (4). A significant effect is obtained in that the thickness (t15) of the insulating layer (17) for adjusting the height is added to the thickness as it is.

That is, by adjusting the thickness (t15) of the insulating layer (17), the height of the whole functioning as the spacer (the spacer (4) and the insulating layer (17)) can be arbitrarily set. It is.
FIG. 6 shows each part of the thickness shown in Table 1.

また、表２は、着色層の構成を２層とした際の結果を表したものである。表２に示すように、条件１１に比較して、絶縁層（１７）を設けた際には、条件１２に表わされるように、スペーサの高さ全体には、スペーサ（４）の厚さに、高さを調整する絶縁層（１７）の厚さ（ｔ１５）がそのまま加算されるといった著しい効果が得られている。
すなわち、表１に示す結果と、表２に示す結果とを合わせると、スペーサとして機能する全体（スペーサ（４）及び絶縁層（１７））の高さは、例えば、１．８μｍ〜４．５μｍといった広範囲の間で任意の高さにすることが可能である。

Table 2 shows the results when the colored layer has two layers. As shown in Table 2, when the insulating layer (17) is provided in comparison with the condition 11, as shown in the condition 12, the entire height of the spacer is equal to the thickness of the spacer (4). A remarkable effect is obtained in that the thickness (t15) of the insulating layer (17) for adjusting the height is added as it is.
That is, when the results shown in Table 1 and the results shown in Table 2 are combined, the total height (spacer (4) and insulating layer (17)) functioning as a spacer is, for example, 1.8 μm to 4.5 μm. It is possible to set the height arbitrarily within a wide range.

  As a method of forming a black matrix layer or a colored layer on a transparent substrate, a photolithography method using a pigment dispersion method resist has become the mainstream. In this method, a colored layer is formed in a pixel shape by patterning a coating layer of a colored photosensitive resin (colored photoresist) in which a coloring material such as an organic pigment is dispersed by a photolithography method.

  The black matrix layer is formed using a black resin. It is a thin light-shielding pattern formed between colored layers in order to improve the contrast of a liquid crystal display device. As a method of forming the black matrix layer, a method of forming a protective resist by a photolithography method using a black non-photosensitive resin and forming a matrix by etching, or a photolithography method using a black photosensitive resin (black photoresist) There is a method of forming a matrix. As the black color material, carbon black, titanium oxide, or the like can be used.

The black photosensitive resin and the colored photosensitive resin used for forming the black matrix layer and the colored layer are, for example, a pigment dispersed in a resin binder using a dispersant, and a monomer, an initiator, a sensitizer, a solvent in the dispersion. Etc. are added.
In the present embodiment, the black photosensitive resin and the colored photosensitive resin used for forming the black matrix layer and the colored layer are mainly composed of a resin binder and an initiator, and the resin binder is photopolymerized, thermally polymerized, or photopolymerized. It undergoes three-dimensional crosslinking through polymerization and thermal polymerization.

By three-dimensionally crosslinking the resin binder of the black matrix layer and the colored layer, it is possible to suppress the thickness of the black matrix layer and the colored layer from being reduced by the load in the panel assembling process.
Examples of resin binders suitable for photopolymerization include acrylate resins, examples of resin binders suitable for thermal polymerization include epoxy resins, and examples of resin binders suitable for photopolymerization and thermal polymerization include epoxy acrylate resins. It is done.

As the photosensitive resin (photoresist) used for the material of the insulating layer, for example, a photosensitive resin mainly composed of an alkali-soluble resin, a photopolymerizable monomer, and a photopolymerization initiator can be used. A novolac resin may be used as the positive resin material. For example, as a commercially available positive-type resin material, LC100 or LC120 manufactured by Rohm and Haas Co., Ltd., or AZMir701 manufactured by AZ Electric Materials Co., Ltd. is used. (Thickness) insulating layer.
Examples of the alkali-soluble resin include (meth) acrylic resins containing maleic acid, maleic resins, rosin resins, and novolac resins.

  As the polymerizable monomer, for example, the following monomers can be mixed or used alone. For example, monomers containing a hydroxyl group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, Triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tetramethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaerythritol di (meth) ) Acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate , (Meth) acrylic esters such as dipentaerythritol hexa (meth) acrylate, glycerol (meth) acrylate, or pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanyl Examples include (meth) acrylates, hexa (meth) acrylates of caprolactone adducts of dipentaerystol hexa (meth) acrylate, and melamine (meth) acrylates.

  It is preferable that a part of the polymerizable monomer is a polymerizable monomer containing a carboxyl group-containing polyfunctional monomer. For example, pentaerythritol or a derivative thereof may be used. These monomers can increase the mixing ratio of the polymerizable monomers while maintaining the photolithographic suitability such as developability without increasing the other resin solids, and further maintaining the elastic recovery rate of the photo spacer. .

Examples of the photopolymerization initiator include acetophenones such as acetophenone, 2,2′-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, and p-tert-butylacetophenone. Benzophenones such as benzophenone, 2-chlorobenzophenone, p, p'-bisdimethylaminobenzophenone, benzoin ethers such as benzyl, benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyldimethyl ketal, thioxanthone, Sulfur compounds such as 2-chlorothiosanson, 2,4-diethylthioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, 2- Anthraquinones such as tilanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-diphenylanthraquinone, 2,4-trichloromethyl- (4′-methoxyphenyl) -6-triazine, 2,4-trichloromethyl Triazines such as-(4'-methoxynaphthyl) -6-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, 2,4-trichloromethyl- (4'-methoxystyryl) -6-triazine , Organic peroxides such as azobisisobutyronitrile, benzoyl peroxide, cumene peroxide, thiol compounds such as 2-mercaptobenzoimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, etc. α-aminoketone photopolymerization Initiator 2-methyl-1 [4 (Methylthio) phenylto2] -morpholinopropan-1-one (Irgacure 907: manufactured by Ciba Specialty Chemicals: trade name), 2-benzyl-2-dimethylaminoate (4-morpholinophenyltobunon-1) (Irgacure 369: Ciba Specialty Chemicals, Inc .: trade name), etc. The α-aminoketone photopolymerization initiator gives the spacer strength of the waist, that is, mechanical strength per unit area of the spacer itself. Is.

  Within the display surface of a 40 "class size liquid crystal display device, the variation in the height of the spacer formed by photolithography is within a range of ± 0.05 μm when small and ± 0.2 μm when large. Even when variation is assumed, the amount of deformation at the time of manufacturing the panel must be at least 0.16 μm (the variation between the spacer having a height of +0.1 μm and the spacer having a height of −0.1 μm is (It is necessary to absorb the load and the deformation of the spacer.) If the variation is large, a deformation amount of 0.2 μm or more is required.

  In addition, since only the colored layer to which the organic pigment is added is rigidly elastic, it is desirable to secure the elasticity of the spacer by using an insulating layer that does not contain the organic pigment. By providing the insulating layer, it is possible to absorb a margin of about 0.2 μm deformation amount in the liquid crystal cell forming step in the spacer height direction.

  For the red colored layer, for example, C.I. I. PigmentRed 7, 14, 41, 48: 2, 48: 3, 48: 4, 81: 1, 81: 2, 81: 3, 81: 4, 146, 168, 177, 178, 179, 184, 185, 187, Red pigments such as 200, 202, 208, 210, 246, 254, 255, 264, 270, 272, and 279 can be used, and a yellow pigment and an orange pigment can also be used in combination.

  Examples of yellow pigments include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 24, 31, 32, 34, 35, 35: 1, 36, 36: 1, 37 37: 1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 93, 94, 95, 97, 98, 100, 101, 104 , 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 126, 127, 128, 129, 138, 139, 147, 150, 151, 152, 153, 154 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 179, 180 181,182,187,188,193,194,199,198,213,214, and the like.

Examples of the orange pigment include C.I. I. Pigment Orange 36, 43, 51, 55, 5
9, 61, 71, 73 and the like.

When the red colored layer contains one or more of diketopyrrolopyrrole red pigment and anthraquinone red pigment among these pigments, it is easy to obtain any Rth, which is preferable.
This is because the diketopyrrolopyrrole red pigment can be made either positive or negative by devising the finer treatment, its absolute value can be controlled to some extent, and the anthraquinone red pigment This is because it is easy to obtain Rth close to 0 regardless of the miniaturization process.

  The amount used is 10 to 90% by weight of the diketopyrrolopyrrole red pigment and 5 to 70% by weight of the anthraquinone red pigment based on the total weight of the pigment. It is preferable from the viewpoints of thickness, contrast, and the like. In particular, when focusing on the contrast, it is more preferable that the diketopyrrolopyrrole red pigment is 25 to 75% by weight and the anthraquinone red pigment is 30 to 60% by weight.

  Examples of the green colored layer include C.I. I. Green pigments such as Pigment Green 7, 10, 36, 37, and 58 can be used, and a yellow pigment can be used in combination. As the yellow pigment, the same pigments as those mentioned for the pigment used in the red colored layer can be used.

  For the blue colored layer, for example, C.I. I. Blue pigments such as Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60, and 64 can be used, and a purple pigment can be used in combination. Examples of purple pigments include C.I. I. PigmentViolet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50 and the like.

When the blue colored layer contains at least one of a metal phthalocyanine blue pigment and a dioxazine purple pigment among these pigments, it is easy to obtain a phase difference close to zero. The amount used is 40 to 100% by weight of the metal phthalocyanine blue pigment and 1 to 50% by weight of the dioxazine violet pigment based on the total weight of the pigment. From the above point, it is preferable that the metal phthalocyanine blue pigment is 50 to 98% by weight, and the dioxazine purple pigment is 2 to 25% by weight.
In the above, examples of the metal phthalocyanine blue pigment include C.I. I. Pigment Blue 15: 6, and dioxazine-based purple pigments include C.I. I. PigmentViolet 23 is preferable in terms of excellent light resistance, heat resistance, transparency, coloring power, and the like.

  If necessary, a colorant may be added to the resin constituting the insulating layer. As the colorant, organic pigments, inorganic pigments, dyes, and the like can be suitably used, and various additives such as an ultraviolet absorber, a dispersant, and a leveling agent may be added. When light shielding properties are required for the insulating layer, in addition to light shielding agents such as metal oxide powders such as carbon black, titanium oxide, and iron tetroxide, metal sulfide powders, and metal powders, red, blue, green, etc. A mixture of pigments or the like can be used. Among these, carbon black is particularly preferable because of its excellent light shielding properties. When the insulating layer is required to have light shielding properties and insulating properties, fine particles of insulating inorganic compounds such as aluminum oxide, titanium oxide, and iron oxide, and carbon black with a resin coated on the surface may be used.

  As a method for forming the insulating layer, a method of patterning after applying an uncured resin on the substrate and drying it is preferably used from the viewpoint that the insulating layer can be formed with high accuracy. As a method for applying the uncured resin, a dip method, a roll coater method, a spinner method, a die coating method, a wire bar coating method, etc. are preferably used, and then pre-dried (prebaked using an oven or a hot plate). )I do. Although prebaking conditions change with resin to be used, a solvent, and resin application quantity, it is preferable to heat at 60-200 degreeC normally for 1 to 60 minutes.

  The resin film thus obtained is exposed and developed as it is or after an oxygen barrier film is formed. For example, when a positive type photoresist is used, a light-shielding portion arranged at a position corresponding to the stack and a position corresponding to the etching protection film on the colored layer at a distance of 100 μm from the photoresist layer. A multi-tone mask having a light-transmitting portion is arranged and irradiated with ultraviolet rays for 10 seconds by a proximity aligner using a 2 kW ultra-high pressure mercury lamp.

  Next, it is immersed in a 0.05 wt% potassium hydroxide aqueous solution for 1 minute to perform alkali development, to remove only the solubilized portion of the photoresist, and to provide an insulating layer on the spacer and a slit for liquid crystal alignment on the colored layer. An etching protective film is formed. Next, the transparent electrode is etched with a hydrochloric acid / ferric chloride mixed aqueous solution to form slits for liquid crystal alignment. Further, the protective film on the colored layer that has become unnecessary is peeled off with a 10% aqueous sodium hydroxide solution. At this time, the insulating film on the spacer remains without being peeled off because it is not exposed to the light shielding portion of the mask, but the etching protective film on the colored layer is exposed to the semi-transparent portion of the mask, so that the concentration is high. Stripped with an aqueous alkali solution.

  As a method for adjusting the transmittance of exposure light used for the multi-tone mask, a conventionally known method can be used. Such a multi-tone mask has a light-shielding film that substantially shields the exposure light and a semi-transparent film that transmits the exposure light at a desired transmittance. There is a halftone mask method that produces gradation by having a light-shielding portion that does not transmit light and a semi-transparent portion that adjusts the amount of transmitted light, and an ITO film, a chromium oxide film, or the like is used for the semi-transparent portion I can do things.

After peeling off the etching protective film on the colored layer, if necessary, it is heat-dried (hardened). As for the hardening conditions, heating is usually performed at 150 to 300 ° C. for 1 to 60 minutes.
Through the above process, an insulating layer is formed on the transparent substrate. When it is difficult to obtain a sufficient height by one patterning, a plurality of resin layers can be laminated.

  Table 3 shows the results of concrete measurement and evaluation of the elastic characteristics of the color filter (CF4) of one example shown in FIG. 4 and the color filter (CF1) shown in FIG. 1 as a comparative example. Is. The insulating layer (17) of the color filter (CF4) is formed using a positive photoresist that does not contain a pigment. The spacer heights of the color filter (CF4) and the color filter (CF1) were both 3.5 μm.

  As shown in Table 3, the elastic recovery rate of the comparative example is 80%, whereas the elastic recovery rate of one example provided with the insulating layer (17) is 84%, and the elastic recovery rate is improved. Is obtained.

弾性特性の評価方法は、以下の通りである。
［スペーサの弾性測定］
弾性特性を微小膜硬度計ＨＭ２０００（フィッシャー・インストルメンツ社製）によって評価する。弾性特性は、５０μｍ×５０μｍの平坦圧子を用い、２．２ｍＮ／ｓｅｃの速度で２０ｍＮの荷重を負荷し、５秒間保持した後、２．２ｍＮ／ｓｅｃの速度で０．４ｍＮまで荷重を除去したときの総変形量、塑性変形量を測定する。総変形量、塑性変形量、弾性復元率は、以下の式で表される値である。まとめたものを表３に示した。なお、スペーサの大きさは、平面視で径およそ１６μｍの円形状とする。
Ａ:スペーサの初期高さ
Ｂ:所定荷重を付加時における高さ
Ｃ：所定荷重を付加した後、荷重を除去した後の高さ
総変形量：Ａ−Ｂで表される変形量。
塑性変形量：Ａ−Ｃで表される変形量
弾性復元率：［（Ｃ−Ｂ）／（Ａ−Ｂ）］×１００で表される変形率
また、弾性特性の評価として、真空気泡（低温気泡）の発生について測定を行った。
上記比較例としてのカラーフィルタ（ＣＦ１）にては低温気泡が発生したが、一実施例のカラーフィルタ（ＣＦ４）では低温気泡の発生はみられないといった結果が得られている。

The evaluation method of the elastic property is as follows.
[Measurement of spacer elasticity]
The elastic characteristics are evaluated by a micro film hardness meter HM2000 (Fischer Instruments). The elastic characteristics were obtained by using a flat indenter of 50 μm × 50 μm, applying a load of 20 mN at a speed of 2.2 mN / sec, holding it for 5 seconds, and then removing the load to 0.4 mN at a speed of 2.2 mN / sec. Measure the total deformation amount and plastic deformation amount. The total deformation amount, the plastic deformation amount, and the elastic recovery rate are values represented by the following expressions. The summary is shown in Table 3. Note that the size of the spacer is a circular shape having a diameter of about 16 μm in plan view.
A: Initial height of the spacer B: Height when a predetermined load is applied C: Total height deformation amount after applying the predetermined load and then removing the load: Deformation amount represented by AB.
Plastic deformation amount: Deformation amount represented by A-C Elastic recovery rate: Deformation rate represented by [(C−B) / (A−B)] × 100 Further, as an evaluation of elastic properties, vacuum bubbles (low temperature The generation of bubbles was measured.
In the color filter (CF1) as the comparative example, low temperature bubbles were generated, but in the color filter (CF4) of one example, the generation of low temperature bubbles was not observed.

[Low temperature impact test]
Whether the liquid crystal panel is allowed to stand at −20 ° C. for 3 hours, and a metal sphere having a diameter of 11 mm and a weight of 5 g is dropped from the height of 10 cm to the panel five times at a low temperature. To check.

FIG. 7 is a cross-sectional view showing an example of a color filter according to a third aspect.
As shown in FIG. 7, the color filter (CF7) is formed on the transparent substrate (1), on the black matrix layer (2), the three colored layers (3R, 3G, (3B)), the spacer (4), A transparent electrode film (5) and an insulating layer (17) are sequentially formed.
The spacer (4) is formed by laminating a red colored layer (3R ′), a green colored layer (3G ′), and a blue colored layer (3R ′). The slit (6) regulates the orientation of the liquid crystal, and is formed by photoetching the transparent electrode film (5).

The insulating layer (17) on the spacer (4) is formed so as to cover from the upper part to the lower part of the spacer. The color filter (CF7) can be easily obtained by adjusting the size of the light shielding portion (21) corresponding to the formation of the insulating layer (17) on the photomask (20) in FIG. As shown in FIG. 7, since the insulating layer (17) is provided so as to cover the upper part to the lower part of the spacer, the elution of impurities from the colored layer to the liquid crystal can be prevented.
Thereby, disorder of the alignment of the liquid crystal is suppressed, the contrast of the liquid crystal display device is improved, and the display quality is improved.

  As a result of actually measuring the contrast between the liquid crystal display device using the color filter (CF7) shown in FIG. 7 and the liquid crystal display device using the color filter (CF1) shown in FIG. 1 as a comparative example, the color filter (CF1) The contrast of the liquid crystal display device using the color filter was 1500: 1, but the contrast of the liquid crystal display device using the color filter (CF7) was improved to 2000: 1.

The method for evaluating the contrast of the liquid crystal display device is as follows.
[Contrast measurement method]
An alignment film of polyimide is formed with 800 mm on the color filter and the counter TFT substrate, and a liquid crystal is dropped by an ODF method (One Drop Fill), a sealing material is applied, and the liquid crystal is bonded in a vacuum and filled with the liquid crystal. Thereafter, the bonded substrates are baked at 120 ° C. for 1 hour to cure the sealing material, thereby creating a liquid crystal panel.
The contrast of the liquid crystal panel is a numerical value represented by (luminance when displaying white) / (luminance when displaying black).
Topcon (made by Topcon): luminance meter BM-5A is used for the measuring machine, and the measurement is performed in a dark room.
A voltage is applied to the liquid crystal panel, and the brightness and voltage when displaying all white are solved to measure the brightness when displaying all black, and the panel contrast is calculated.

  The color filter according to claim 4 is characterized in that a spacer formed by laminating colored layers of three primary colors is formed on the black matrix layer. By forming the spacer on the black matrix layer, it is possible to increase the aperture ratio of the display region as compared with the case of forming the spacer on the colored layer, and to prevent display defects due to poor alignment of the liquid crystal. it can.

FIG. 8 is a sectional view showing an example of a color filter according to claim 5.
This color filter has two types of spacers having different heights by changing the number of layers of the three primary color layers. As shown in FIG. 8, this color filter (CF8) is formed on a transparent substrate (1), a black matrix layer (2), three colored layers (3R, 3G, (3B)), a spacer (4), A second spacer (14), a transparent electrode film (5), and an insulating layer (17) are sequentially formed.

  The spacer (4) is formed by laminating three layers of a red colored layer (3R ′), a green colored layer (3G ′), and a blue colored layer (3R ′). Have The second spacer (14) is formed by laminating two layers of a red colored layer (3R ′) and a green colored layer (3G ′), and the height is higher than the height of the spacer (4). It has a height indicated by a low code (t22) (t21> t22). The slit (6) regulates the orientation of the liquid crystal, and is formed by photoetching the transparent electrode film (5).

  In the process of assembling the liquid crystal panel by attaching the color filter and the counter substrate to each other, a seal portion is provided at the periphery, the gap between the color filter and the counter substrate is made parallel, a load is applied between the upper and lower surface plates, and the seal portion and spacer The spacers are deformed by the load applied at this time, so that the gap between the substrates is set in the deformed state. At this time, if an excessive load is locally applied, the gap between the substrates may be reduced to cause color unevenness.

A color filter for a liquid crystal display device having two types of spacers has been proposed to cope with such a locally excessive load. The color filter shown in FIG. 8 is an example. The two types of spacers are a spacer (4) and a second spacer (14).
The spacer (4) is a spacer corresponding to deformation caused by a load during panel assembly and the low-temperature bubbles. The second spacer (14) is a spacer that prevents the spacer (4) from being broken and maintains a gap between the substrates when receiving an excessive load locally.

  The spacer (4) and the second spacer (14) of the color filter (CF8) shown in FIG. 8 are, for example, three types of photomasks, that is, a red colored layer (3R) and a red colored layer (3) of the spacer (4). 3R ′) and a red photomask having a pattern corresponding to the formation of the red colored layer (3R ′) of the second spacer (14), the green colored layer (3G), and the green colored layer (3G) of the spacer (4) ') And a green photomask having a pattern corresponding to the formation of the green colored layer (3G') of the second spacer (14), the blue colored layer (3B), and the blue colored layer (3B 'of the spacer (4)) ) And a blue photomask having a pattern corresponding to the formation.

  The ratio of the number of spacers (4) and second spacers (14) formed in the color filter is not particularly limited, but is about [1: 2] to [2: 1].

What has been described above is a color filter in which the insulating layer according to the present invention is directly formed on a transparent substrate of a color filter by a photolithography method such as exposure and development of a photoresist layer through a photomask.
In the present invention, although the number of steps is increased, the insulating layer may be formed by a transfer method in order to compensate for the drawbacks of the spacer formed by laminating the colored layers.

  That is, a transfer substrate having a resin layer with photosensitivity formed on a base material is prepared in advance, and this is overlaid on the substrate while applying heat and pressure as necessary, exposed and developed, and thereafter A method in which the insulating layer is formed on the substrate by peeling the material, or an insulating layer is formed on the transfer substrate in advance by photolithography or the like, and this is overlapped with the transparent substrate, and heat or pressure is applied to the transfer substrate. In this method, the insulating layer is transferred.

A filler or a colorant may be added to the insulating layer within a range that does not affect properties such as elasticity of the insulating layer. The filler refers to inorganic and organic particles that are insoluble in the resin, its solvent, and developer.
Inorganic particles include extender pigments such as silica, barium sulfate, barium carbonate, calcium carbonate and talc, and colored pigments such as white, black, red, blue and green, and alumina, zirconia, magnesia, beryllia, mullite, cordierite. Ceramic powder such as, glass-ceramic composite powder, and the like are used. Of the extender pigments, barite, barium sulfate, barium carbonate, calcium carbonate, silica, and talc are particularly preferable because they are not colored and the insulating layer can be made transparent.

Further, when the insulating layer is required to have light shielding properties, carbon black, titanium black (TiNxOy: where 0 ≦ x <1.5, 0.1 <y <1.8), manganese oxide, iron tetroxide , Etc., metal oxide powder, metal sulfide powder, and metal powder can be used. Among these, carbon black is particularly preferable because of its excellent light shielding properties. When the insulating layer is required to have light shielding properties and insulating properties, insulating inorganic particles such as aluminum oxide, titanium black, and iron oxide, or carbon black whose surface is coated with a resin may be used.
The average primary particle diameter of the filler is preferably 5 to 40 nm, more preferably 6 to 35 nm, and still more preferably 8 to 30 nm.

It is sectional drawing of an example of the color filter in which the slit formed in the spacer formed by laminating | stacking a colored layer and a transparent electrode film. It is sectional drawing of an example of the color filter which compensates the fault which the spacer formed by laminating | stacking a colored layer has. It is sectional drawing of the other example of the color filter which compensates the fault which the spacer formed by laminating | stacking a colored layer has. It is sectional drawing of one Example of the color filter for liquid crystal display devices by this invention. (A)-(d) is sectional drawing explaining an example of the method of forming an insulating layer in this invention. Each part of the thickness shown in Table 1 is represented. It is sectional drawing which shows an example of the color filter concerning Claim 3. It is sectional drawing which shows an example of the color filter concerning Claim 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transparent substrate 2 ... Black matrix layer 3R ... Red colored layer 3G ... Green colored layer 3B ... Blue colored layer 3R ', 3G', 3B '... 3 which comprises a spacer Colored colored layer 4 ... spacer 5 ... transparent electrode film 6 ... slit 7 ... adjustment layer 8 ... transparent protective layer 10 ... photoresist layer 14 ... second spacer 15 .. Etching protective film 16... Opening 17... Insulating layer 20... Photomask 21. Color filter E ... Exposure

Claims (6)

In a color filter for a liquid crystal display device comprising a black matrix layer, three primary color layers, a spacer, and a transparent electrode film on a transparent substrate, the spacer is formed by laminating at least two primary color layers of the three primary colors. Formed and having an insulating layer also serving as adjustment of the height of the transparent electrode film and the spacer on the spacer,
And the insulating layer on the spacer is formed so as to cover from the upper part to the lower part of the spacer,
And the insulating layer on the spacer is formed of the same material as the etching protective film used when forming the slit in the transparent electrode film, and the material is an alkali-soluble positive photosensitive resin,
The transparent electrode film on the colored layers of the three primary colors has a slit for regulating the alignment of liquid crystal. The spacer, the color filter according to claim 1, characterized in that it is formed on the black matrix layer. Changing the number of stacked layers of the colored layers of the three primary colors, according to claim 1 or 2 color filter according to characterized in that it has two or more spacers of different heights. A method of manufacturing a color filter according to any one of claims 1 to 3, at least,
1) A step of forming a photoresist layer for forming an insulating layer and an etching protective film on a transparent substrate on which a black matrix layer, three colored layers, a spacer, and a transparent electrode film are formed,
2) An etching protective film having an opening corresponding to the formation of an insulating layer and a slit by exposing and developing the photoresist layer through a photomask which is a multi-tone mask using an ITO film in a semi-transparent portion. Forming step,
3) forming a slit in the transparent electrode film by etching,
4) A step of peeling off the etching protective film on the transparent electrode film above the colored layer. 4. A manufacturing method for manufacturing a color filter according to claim 3 , wherein each of the three primary colors has a pattern corresponding to the number of layers to be laminated as a pattern corresponding to the formation of the colored layers of the three primary colors constituting the spacer. A method for producing a color filter, comprising using a mask. The liquid crystal display device characterized by using the color filter according to any one of claims 1 to 3.

Images