JP2009204840A - Color filter for liquid crystal display and liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color filter for a liquid crystal display, wherein display irregularities are not caused even when force is locally added, and color mixing, color unevenness and the like due to alignment failure are hardly caused upon forming a spacer, and to provide a liquid crystal display. <P>SOLUTION: The color filter for a liquid crystal display includes: a black matrix layer formed on a transparent substrate; color pixels in a plurality of colors formed in pixel regions on the transparent substrate segmented by the black matrix layer; and a spacer formed on the black matrix layer, wherein the spacer includes a laminate comprising a red layer, a blue layer and an insulating layer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a color filter for a liquid crystal display device, and more particularly to a color filter for a liquid crystal display device including a photo spacer and a liquid crystal display device.

  There are two types of color liquid crystal display devices, the simple matrix method and the active matrix method, depending on the liquid crystal driving method. Recently, for display devices such as personal computers, the image quality is excellent and each pixel can be controlled reliably. In addition, the adoption of an active matrix method with a high operating speed is being promoted.

  In an active matrix liquid crystal display device, in general, a TFT substrate in which a thin film transistor (TFT) element is formed for each pixel on a glass substrate, a color filter substrate in which a color filter and a uniform transparent electrode are formed on the glass substrate, However, they are arranged opposite to each other with a liquid crystal in between. The shutter action of the liquid crystal of each pixel is controlled by the switching action of each TFT element on the TFT substrate.

  In recent years, along with higher image quality such as larger size, higher definition, wide viewing angle and higher contrast of liquid crystal display devices, VA liquid crystal called vertical alignment, and electric field for driving liquid crystal in the horizontal direction of pixels An IPS (In Plane Switching) type liquid crystal display device to which is applied has been adopted. In the latter IPS liquid crystal display device, it is not necessary to form a transparent electrode on the color filter substrate. As a technique for forming a spacer on a color filter substrate of such an IPS liquid crystal display device, for example, there is one proposed in Patent Document 1.

  For the transparent electrode, tin oxide, indium oxide, or a composite oxide called ITO is used. As a method for forming a transparent electrode, there are various methods such as vapor deposition, ion plating, and sputtering. Sputtering is widely used. A technique for forming ITO is proposed in Patent Document 2.

A liquid crystal display device using TFTs is configured by arranging a TFT substrate and a color filter substrate facing each other with a predetermined gap, and bonding these substrates together with a sealing agent in which reinforcing fibers are mixed with epoxy resin or the like. Is done. Liquid crystal is sealed between the color filter substrate and the TFT substrate, but if the distance between the color filter substrate and the TFT substrate is not accurately maintained, the thickness of the liquid crystal layer will differ, resulting in a difference in the optical rotation characteristics of the liquid crystal. This causes a phenomenon in which coloring is caused by or a partial color unevenness occurs and the image is not displayed correctly. Therefore, a large number of particles or rods made of resin, glass, alumina, or the like having a diameter of 2 μm to 10 μm, which are called spacers, are mixed in the liquid crystal to maintain the liquid crystal sandwiching interval.
Japanese Patent Laid-Open No. 10-48636 JP-A-8-262484

In a normal liquid crystal display device, a large amount of particles of about 100 particles / mm ² are mixed with the liquid crystal as a spacer, so it is mixed with a highly viscous liquid crystal and injected within the interval between the color filter substrate and the TFT substrate. In such a case, a phenomenon may occur in which the spacers are not uniformly dispersed and the spacers are partially biased. When such a phenomenon occurs, the display quality of the portion where the spacers are gathered deteriorates, and there is a problem in terms of accurately maintaining the interval.

  On the other hand, in a color filter for a liquid crystal display device using, as a spacer (photospacer), a color layer constituting a color filter, for example, a structure in which three colors, for example, a red layer, a green layer, and a blue layer are overlaid, is used. In some cases, display failure occurred when subjected to force or impact. In particular, when force is applied locally, it is recognized as display unevenness, and the display quality may be lowered.

  In addition, there may be a problem when the height of the formed spacer varies. That is, when assembling the cell (panel), a certain amount of force is applied to attach the two substrates for the liquid crystal display element, but when the force that pressed the substrate is removed, the spacer returns to the original height, There may be a problem that the height of the spacer becomes uneven. In the case of a spacer having a three-color laminated structure, since the flexibility is poor and it is too hard, the liquid crystal is not uniformly injected when the color filter substrate and the TFT substrate are bonded together, or the liquid crystal cell changes over time, and the display device surface Bubbles may be generated inside. In addition, when the color filter layer is formed by stacking three colors (blue layer, red layer, and green layer) on the black matrix, alignment control becomes difficult. That is, when the color filter layer deviates from the black matrix, color misregistration occurs, causing problems such as color mixing, and there is a problem that image display quality is degraded. When three color filter layers are stacked on a black matrix, there is a probability of occurrence of color misregistration due to poor alignment three times, which is accompanied by defect expansion such as color mixture and color unevenness.

  The present invention has been made under the circumstances as described above, and even when a force is applied locally, display unevenness does not occur, and liquid crystal display and color unevenness due to poor alignment are unlikely to occur during spacer formation. An object is to provide a color filter for a device and a liquid crystal display device.

  In order to solve the above problems, a first aspect of the present invention is a black matrix layer formed on a transparent substrate, and a plurality of colors formed in a pixel region on the transparent substrate defined by the black matrix layer. A color filter for a liquid crystal display device comprising a pixel and a spacer formed on the black matrix layer, wherein the spacer includes a laminate composed of a red layer, a blue layer, and an insulating layer. A color filter for an apparatus is provided.

  In the color filter for a liquid crystal display device, the thickness of the insulating layer of the spacer may be in the range of 0.5 μm to 3 μm. In addition, the spacer may include a laminate composed of two layers and an insulating layer in which a red layer and a blue layer are stacked in this order on a black matrix layer.

  The hardness of the layer constituting the spacer may be such that the hardness of the black matrix layer ≧ the hardness of the red layer ≧ the hardness of the blue layer ≧ the hardness of the insulating layer. The colored pixels of the plurality of colors may include a plurality of pixel units each including a red pixel, a green pixel, and a blue pixel, and one spacer may exist for each pixel unit. I can do it. Further, the spacer can be disposed adjacent to the red pixel and the blue pixel.

  In the color filter for a liquid crystal display device of the present invention, the insulating layer has a total deformation amount of 0.2 μm to 0.5 μm when a compressive load of 20 mN / piece is applied from the height direction thereof, and The amount of plastic deformation when a compressive load of 60 mN / piece is applied and the load is removed can be 0.01 μm to 0.1 μm. The spacer has a total deformation amount of 0.22 μm to 0.53 μm when a compression load of 20 mN / piece is applied in the height direction, and a load of 60 mN / piece is applied to remove the load. The amount of plastic deformation at this time can be 0.01 μm to 0.1 μm.

  Further, a liquid crystal alignment control protrusion may be provided on the colored pixel formed in the pixel region, and the height of the insulating layer may be the same as or lower than the height of the liquid crystal alignment control protrusion. Further, a transparent electrode may be provided on the colored pixels and the colored layer, and the insulating layer may be formed on the transparent electrode. Furthermore, it can be set as the structure provided with the transparent electrode which has an opening part in a pixel center part on the coloring pixel except the said spacer part.

  According to a second aspect of the present invention, there is provided a liquid crystal display device comprising the above color filter for a liquid crystal display device.

  According to the first aspect of the present invention, since the colored layers constituting the spacer are two layers of the red layer and the blue layer, the number of alignments is reduced as compared with the spacer constituted by the three colored layers. As a result, a color filter for a liquid crystal display device having the effect of reducing the amount of color shift can be obtained.

  In addition, the spacer of the constituent element according to the first aspect of the present invention has two colored layers constituting the spacer, and can form a thicker insulating layer rich in elastic deformation than the three-layer laminated structure. Since the spacer of the present invention has an elastic recovery rate of a predetermined value or more, it is easy to maintain and restore the liquid crystal cell gap uniformly even when an external force or impact is applied, and the display characteristics of the liquid crystal display device are hardly deteriorated. Thus, a color filter for a liquid crystal display device can be obtained.

  In addition, according to the second aspect of the present invention, a liquid crystal display device with a small amount of color misregistration and a display characteristic that hardly deteriorates can be obtained.

  The color filter for a liquid crystal display device having a spacer according to the present invention is advantageous in that the display characteristics are hardly deteriorated even when an external force or impact is applied. Since the color filter having the spacer according to the present invention is flexible, it can provide a liquid crystal display device free from display defects or defects such as bubble generation.

  Hereinafter, a color filter for a liquid crystal display device according to an embodiment of the present invention will be described in detail.

  The color filter for a liquid crystal display device according to the first embodiment of the present invention includes a spacer including a laminate including a red layer, a blue layer, and an insulating layer on a black matrix layer. That is, as the colored layer constituting the spacer, two colors are used instead of three colors, and a red layer and a blue layer are selected. The reason is as follows.

  FIG. 1 shows the change in transmittance with the wavelength of the red layer, FIG. 2 shows the change in transmittance with the wavelength of the blue layer, and FIG. 3 shows the change in transmittance with the wavelength of the green layer. Further, FIG. 4 shows a change in transmittance depending on the wavelength when the red layer and the blue layer are overlapped, FIG. 5 shows a change in transmittance due to the wavelength when the red layer and the green layer are overlapped, and FIG. 6 shows a green layer and a blue layer. The change of the transmittance | permeability by the wavelength when each is piled up is shown, respectively.

  When two colors are superimposed, the wavelength when the red layer and the blue layer shown in FIG. In other words, when two colors of the red layer and the blue layer are superimposed on the black matrix, the color becomes black with no color leakage, and color mixing due to misalignment (misalignment) is the least likely to occur, so image display quality is unlikely to deteriorate. . In addition, since the number of alignments is smaller in the spacer formed by superimposing two colors than the spacer formed by superimposing the three colors of the color filter layer, the amount of deviation is small.

  Usually, the alignment accuracy related to the formation of one colored layer is about ± 3 μm, and therefore it is better that the number of alignments is smaller. In particular, the spacers arranged on the black matrix are liable to adversely affect the occurrence of defects such as pixel aperture ratio and color mixture, and therefore it is preferable that the number of color layers to be superimposed is small.

  In the color filter according to the present embodiment, the insulating layer as a spacer satisfies the mechanical properties such as the elastic recovery rate described in detail below, and retains electrical insulation that does not hinder the driving of the liquid crystal. If you do.

  With the color filter according to the present embodiment, the amount of misalignment is substantially 2/3, so that the pixel aperture ratio can be prevented from lowering than the conventional one, and at the same time, the image display quality due to color mixing is less likely to deteriorate.

  According to the color filter of the present invention, it is possible to obtain an effect that display characteristics are hardly deteriorated even when an external force or impact is applied. Since the color filter according to the present embodiment has flexibility, it can provide a liquid crystal display device free from display defects or defects such as bubble generation.

  When a compression load of 60 mN / piece is applied in the height direction of the spacer and the elastic recovery rate is less than 93% when the load is removed, the display characteristics deteriorate when an external force or impact is applied. The problem arises.

  In the color filters according to the first and second embodiments described above, in particular, the total deformation amount when a compressive load of 20 mN / piece is applied in the height direction of the spacer is 0.22 μm to 0.53 μm, and The amount of plastic deformation when a compressive load of 60 mN / piece is applied and the load is removed is preferably 0.01 μm to 0.1 μm. The color filter showing such total deformation amount and plastic deformation amount has an effect that the liquid crystal cell gap is easily maintained and restored even when an external force or impact is applied, so that display characteristics are hardly deteriorated.

  The present inventors applied a large load of 10 mN to 30 mN, a large load of 50 mN to 200 mN, and a plastic deformation amount after removing the load is an index for improving the uniformity of liquid crystal panel formation. I have found out from experience. The amount of plastic deformation remaining after removal of the load is desirably ¼ or less, preferably ８ or less of the wavelength of light, from the viewpoint of a liquid crystal display device using light. If the amount of plastic deformation close to the wavelength of the light remains, the display color will change, or partial color unevenness will occur. For example, assuming a wavelength of light in the blue region of 0.43 μm, it is desirable to suppress the plastic deformation amount of the spacer within 0.1 μm. For example, assuming a wavelength of light in the blue region of 0.54 μm, it is desirable to suppress the plastic deformation amount of the spacer to within 0.14 μm.

  Recently, the cell gap of the liquid crystal display device is narrowed to 2 to 4 μm for the purpose of high-speed response of the liquid crystal. On the premise of this, the height of the spacer is 2 to 4 μm.

In the liquid crystal display device having a cell gap of 2 μm, the present inventors have an elastic recovery rate of 95% or more based on the necessity of the amount of plastic deformation of the spacer being 0.1 μm or less, and the plasticity of the spacer. Based on the necessity of a deformation amount of 0.14 μm or less, it was found that 93% or more is required. In addition, in the case of a configuration having a liquid crystal alignment control protrusion on the pixel of the color filter, a part of the spacer is used. The height of the insulating layer to be formed is desirably the same as or lower than the height of the liquid crystal alignment control protrusion of the liquid crystal molecules. In this case, the liquid crystal alignment control protrusion and the insulating layer are formed in the same process by setting the thickness of the insulating layer to 0.5 μm to 2.0 μm, which is a general height (thickness) of the liquid crystal alignment control protrusion. It can be manufactured and has the effect of improving productivity.

  The spacers in the color filters according to the first and second embodiments described above may be used as sub-spacers by changing the height of half of the total number to be formed or by reducing the height. Alternatively, a new sub-spacer may be formed at another position of the spacer. A larger number of sub-spacers may be formed than the number of spacers. The role of the sub-spacer is to protect the liquid crystal display device by avoiding large deformation of the TFT substrate and the color filter substrate when a strong load is applied to the liquid crystal cell.

  As a method for forming a color filter layer or a black matrix layer on a transparent substrate, a pigment dispersion method has become the mainstream. The pigment dispersion method is a method of forming a color filter layer in a pixel shape by patterning a coating layer of a colored photosensitive resin in which a color material such as an organic pigment is dispersed by a photolithography method.

  The thickness of the black matrix layer is in the range of 0.5 to 3 μm, the width is in the range of 3 to 30 μm, and the film thickness (thickness) of the red, green and blue pixels is 0.5 to 3 μm (colored photosensitive resin However, when the film thickness of each pixel is about 1.8 μm, the thickness of the red layer formed on the black matrix is about 0.95 μm, and the thickness of the blue layer The thickness of the insulating layer tends to be as thin as about 0.88 μm), the thickness of the insulating layer is 0.5 to 3 μm, or the more preferable thickness of the insulating layer is 1-2 μm in consideration of optical formation by photolithography The liquid crystal cell gap of the liquid crystal display device is in the range of 2 μm to 6 μm applicable to the present invention.

  The black matrix layer is a thin light-shielding pattern formed between pixels to increase the contrast of the liquid crystal display device, which is formed using a black resin. As a method of forming the black matrix layer, there are a method of forming a matrix by a photolithography method using a black non-photosensitive resin, and a method of forming a matrix by a photolithography method using a black photosensitive resin. Carbon black and a plurality of organic pigments can be used as the black color material.

  The black photosensitive resin and the colored photosensitive resin used for forming the black matrix layer and the color filter layer are, for example, a pigment dispersed in a resin binder using a dispersant, and a monomer, an initiator, a sensitizer, It is prepared by adding a solvent or the like.

  In the present embodiment, the black photosensitive resin and the colored photosensitive resin used for forming the black matrix layer and the color filter 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 color filter layer, it is possible to suppress the thickness of the black matrix layer and the color filter layer from being reduced by a load in the panel assembly 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 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 of Rohm & Haas Co., Ltd. or AZMir701 of AZ Electric Materials Co., Ltd., having a height (thickness) of 1 to 2 μm. An insulating layer can be formed.
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 acetophenone, 2,2′-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, p-tert-butylacetophenone, and the like. Acetophenones, benzophenone, 2-chlorobenzophenone, benzophenones such as p, p'-bisdimethylaminobenzophenone, benzoin ethers such as benzyl, benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyldimethyl ketal, Sulfuration of thioxanthone, 2-chlorothiosanson, 2,4-diethylthioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, etc. , Anthraquinones such as 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-diphenylanthraquinone, 2,4-trichloromethyl- (4′-methoxyphenyl) -6-triazine, 2, 4-trichloromethyl- (4′-methoxynaphthyl) -6-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, 2,4-trichloromethyl- (4′-methoxystyryl) -6-triazine Triazines such as azobisisobutyronitrile, organic peroxides such as benzoyl peroxide, cumene peroxide, thiol compounds such as 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, etc. α- 2- is an aminoketone photopolymerization initiator Methyl-1 [4- (methylthio) phenylto2] -morpholinopropan-1-one (Irgacure 907: Ciba Specialty Chemicals, Inc .: trade name), 2-benzyl-2-dimethylaminoate (4-morpholine) Nophenyltobunone-1 (Irgacure 369: manufactured by Ciba Specialty Chemicals, Inc .: trade name), etc. The α-aminoketone photopolymerization initiator is strong against the spacer, that is, per unit area of the spacer itself. The mechanical strength of is given.

  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 in the range of ± 0.08 μm when small and ± 0.2 μm when large. Small variation However, the amount of deformation at the time of panel fabrication must be at least 0.16 μm (the variation between the +0.1 μm height spacer and the −0.1 μm height spacer is the load at the time of bonding. (If the variation is large, a deformation amount of 0.4 μm is necessary.) Considering a large screen of the liquid crystal display device, a deformation amount of at least 0.5 μm is necessary.

Further, according to the results of the study by the present inventors, the amount of deformation of the resin material that can be suitably used for the spacer under a weak load (20 mN / μm ² , which will be described later in the following examples) is the thickness direction of the resin spacer. About 10 to 20%. For example, in the acrylic resin used in the examples described below, the deformation amount at a load of 20 mN / μm ² is about 16%. The height of the insulating layer necessary to cover the above-described deformation amount of 0.16 μm to 0.5 μm is 1 μm to 3 μm. The height of the insulating layer can be adjusted as appropriate according to variations in the formation of spacers and the cell formation conditions of the liquid crystal panel (for example, a liquid crystal cell gap, a liquid crystal display screen size, etc.). Since the color layer to which the organic pigment is added is hard and flexible, it is desirable to ensure the flexibility of the spacer by using an insulating layer that does not contain the organic pigment.

  In the color filter according to this embodiment, the spacer having the laminated structure of the two colored layers and the insulating layer absorbs a margin of about 0.1 to 0.3 μm deformation amount in the liquid crystal cell forming step in the spacer height direction. be able to.

  For the red pixel, for example, C.I. I. Pigment Red 7, 14, 41, 48: 2, 48: 3, 48: 4, 81: 1, 81: 2, 81: 3, 81: 4, 146, 168, 177, 178, 179, 184, 185, Red pigments such as 187, 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, 59, 61, 71, 73 and the like.

  When the red pixel contains one or more of diketopyrrolopyrrole red pigments and anthraquinone red pigments among these pigments, it is preferable because any Rth can be easily obtained.

  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. From the viewpoint of 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.

  For example, 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 used for the red pixel can be used.

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

  When the blue pixel 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. It is preferable from a point, Furthermore, it is more preferable to make a metal phthalocyanine blue pigment 50 to 98 weight% and a dioxazine purple pigment 2 to 25 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. Pigment Violet 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 a colorant,
Organic pigments, inorganic pigments, dyes, and the like can be suitably used, and various additives such as ultraviolet absorbers, dispersants, and leveling agents 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 light shielding property and the insulating property are required for the insulating layer, insulating inorganic compound fine particles such as aluminum oxide, titanium oxide, and iron oxide, or carbon black whose surface is coated with a resin 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 obtained in this manner is used as it is after the photo-colored composition film is formed thereon when the resin is a non-photosensitive resin, and when the resin is a photosensitive resin. Alternatively, exposure and development are performed after the oxygen blocking film is formed. If necessary, heat-dry (harden). Curing conditions vary slightly depending on the type of resin and the coating amount, but in the case of acrylic resins, the curing conditions are generally heated 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.

  An insulating layer may be formed by a transfer method. That is, a transfer substrate on which a resin layer having photosensitivity is formed in advance on a base material is prepared, and this is superimposed on the substrate while applying heat and pressure as necessary, exposed and developed, and then the base material The insulation layer is formed on the transfer substrate by photolithography or the like in advance, and this is overlapped with the transparent substrate, and heat and pressure are applied to the transfer substrate for insulation. A method for transferring a layer.

  To the insulating layer, a filler or a coloring material may be added within a range that does not affect the mechanical properties such as flexibility 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 extenders 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 have no color and can make the protrusions transparent. When the light-shielding property is required for the protrusion, carbon black, titanium black (TiNxOy: where 0 ≦ x <1.5, 0.1 <y <1.8), manganese oxide, iron tetroxide, 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 light-shielding property and the insulating property are required for the protrusion, 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.

  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 black matrix between all pixels, but in order to ensure flexibility in the process of bonding the color filter substrate and the TFT substrate, the red pixel, the green pixel, and the blue pixel are arranged. It is desirable to form one pixel per set. The spacers are arranged on the black matrix between the pixels that make up the above three colors as a set, and the spacers are arranged so as to maintain a constant interval.

  In addition, the spacer may be disposed in an adjacent portion between the red pixel and the blue pixel. The adjacent portion may be arranged at the corner 40 of the pixel as shown in FIG. 10 on the black matrix 12 between the red pixel 13R and the blue pixel 13B. As shown in FIG. It may be arranged at a position 50 between the sides. In either case, the spacers are arranged so as to maintain a constant interval.

  By disposing the spacer only in the adjacent portion of the red pixel and the blue pixel without arranging the spacer in all the color pixels, the number of the spacers can be reduced, thereby increasing the flexibility, and the liquid crystal cell This has the effect of making the cell gap uniform in the process.

  The transparent electrode is formed by vacuum film formation such as sputtering using a plurality of metal oxides selected from indium oxide, tin oxide, zinc oxide, gallium oxide, antimony oxide, and the like.

  Next, the structure of the color filter for liquid crystal display devices according to the first and second embodiments of the present invention will be described with reference to FIGS.

  As shown in FIG. 7, the color filter for a liquid crystal display device includes a black matrix layer 12, a color filter layer 13 (a red layer 13R, a blue layer 13B, and a green layer 13G), a transparent electrode 14, and an insulating layer on a transparent substrate 11. 15 is formed sequentially. On the black matrix layer 12, an extension portion 16R of the red layer 13R and an extension portion 16B of the blue layer 13B are stacked, and constitute a spacer together with the insulating layer 15. A liquid crystal alignment control protrusion 17 is formed on the transparent electrode 14 corresponding to the red layer 13R, the blue layer 13B, and the green layer 13G.

  The color filter for a liquid crystal display device shown in FIG. 7 is manufactured as follows.

  First, the black matrix 12 is formed on the transparent substrate 11. Thereafter, the color filter layer 13 of each color of the red layer 13R, the blue layer 13B, and the green layer 13G is formed. In a liquid crystal display device such as a reflective liquid crystal display device in which a difference in the optical path length of light occurs, the chromaticity of the color filter layer at this time is different from the chromaticity required in the transmission portion and the reflection portion. It is necessary to adjust the film thickness and chromaticity. There are methods for adjusting the chromaticity, such as forming a pattern separately, reducing the thickness of the reflective part, or making holes in the color filter pixels of the reflective part to make it thin. It is not limited to this method.

  In forming the red layer 13R, the colored layer is patterned so that the red extension 16R is formed not only on the pixel region on the transparent substrate 11 but also on the black matrix layer 12. Similarly, when forming the blue layer 13B, the colored layer is patterned so that the blue extension 16B is laminated not only on the pixel region on the transparent substrate 11, but also on the red extension 16R.

  Next, the transparent electrode 14 is formed on the front surface, the insulating layer 15 is formed on the transparent electrode 14 on the stack of the red extension portion 16R and the blue extension portion 16B, and the red extension portion 16R, the blue extension portion 16B, and the insulating layer 15 are insulated. A spacer made of layer 15 is formed.

  Finally, the liquid crystal alignment control protrusions 17 are formed on the transparent electrodes 14 corresponding to the red layer 13R, the blue layer 13B, and the green layer 13G, thereby completing a color filter for a liquid crystal display device as shown in FIG.

  In the color filter according to this embodiment, a transparent protective layer may be formed before forming the transparent electrode. The formation of such a transparent protective layer is disadvantageous in that it complicates the structure of the color filter and increases the manufacturing cost, but on the other hand, it controls the height of the spacer, prevents impurities from bleeding out, and provides a flat surface. It is advantageous to make.

  The alignment control protrusion for the VA liquid crystal display device is required to have high heat resistance and solvent resistance because a liquid crystal alignment film is formed thereon. Further, since the liquid crystal and the liquid crystal alignment control protrusion are in contact with each other through a thin liquid crystal alignment film of 0.2 μm or less, it is also required that the impurity elution is small.

  For the liquid crystal alignment control protrusion, it is preferable to use a polyimide resin, an acrylic resin, an epoxy resin, or a novolac resin having the above-described conditions. The orientation control protrusion may be formed simultaneously with the insulating layer. The height of the alignment control protrusion is usually 1 to 2 μm. However, in the color filter according to the present embodiment, the insulating layer is formed with a film thickness of 1 μm to 3 μm. Can be formed. The method of adjusting the thickness of the black matrix makes it easier to adjust the height of the insulating layer. There is no need to use a costly exposure method such as adjusting the insulating layer height by partially changing the transmittance such as halftone.

  Hereinafter, the elasticity measurement of the insulating layer, the elasticity measurement of the spacer, and the film hardness measurement used in the examples will be described.

[Measurement of elasticity of insulating layer]
An insulating layer as a measurement sample for elasticity measurement was formed as follows.

  First, the polymerizable monomer pentaerythritol triacrylate, the resin a, and the photopolymerization initiator Irgacure 369 are combined to obtain a solid content, which is diluted with cyclohexanone so that the solid content in the resist is 30% by weight. Photosensitive resin composition A was prepared. In the photosensitive resin composition 1, the ratio of the polymerizable monomer to the total weight of the polymerizable monomer and the resin a is 70%.

  A method for synthesizing Resin a is shown below.

  While adding 686 g of propylene glycol monomethyl ether acetate (PGMAc), 332 g of glycidyl methacrylate (GMA), and 6.6 g of azobisisobutyronitrile (AIBN) into a five-neck reaction vessel with an internal volume of 2 liters, while blowing nitrogen Heating was performed at 80 ° C. for 6 hours to obtain a polymer solution of GMA.

Next, 168 g of acrylic acid (AA), methoquinone (
(MQ) 0.05 g and triphenylphosphine (TPP) 0.5 g were added and heated at 100 ° C. for 24 hours while blowing air to obtain an acrylic acid adduct solution of GMA resin.

Further, tetrahydrophthalic anhydride 1 was added to the resulting GMA resin acrylic acid adduct solution.
86 g was added and heated at 70 ° C. for 10 hours to obtain a resin a solution.

  The insulating layer as a measurement sample was formed by applying the photosensitive resin composition A for an insulating layer to a glass substrate, hardening it, and forming the insulating layer into a circular shape having a thickness of 1.4 μm and a size in plan view of about 25 μm in diameter. What was formed was used.

  The elastic recovery rate of the insulating layer having a height of 1.40 μm formed on the glass substrate was evaluated by a microfilm hardness tester HM2000 (manufactured by Fisher Instruments). The elastic recovery rate is obtained when a flat indenter of 50 μm × 50 μm is used, a predetermined load is applied at a speed of 2.2 mN / sec, held for 5 seconds, and then removed to 0 mN at a speed of 2.2 mN / sec. Total deformation and plastic deformation were measured. The total deformation amount, the plastic deformation amount, and the elastic recovery rate are values represented by the following formulas, which are shown in Table 1 below.

A: Initial height of the insulating layer B: Height when a predetermined load is applied C: Height after applying the predetermined load and then removing the load Total deformation amount: Deformation amount represented by AB.

Plastic deformation amount: Deformation amount represented by AC Elastic recovery rate: Deformation rate represented by [(CB) / (AB)] × 100.

[Measurement of spacer elasticity]
The spacer as a sample for measuring elasticity is a spacer having a height of 3.95 μm obtained by applying a black matrix, a red layer, a blue layer, and an insulating layer on a glass substrate in this order, laminating, and hardening. It is. The elastic characteristics of this spacer were evaluated with a microfilm hardness tester HM2000 (manufactured by Fisher Instruments). The insulating layer was formed using the photosensitive resin composition 1 having the same material composition as that of the sample subjected to elasticity measurement.

  The elastic characteristics are obtained when a flat indenter of 50 μm × 50 μm is used, a predetermined load is applied at a speed of 2.2 mN / sec, held for 5 seconds, and then the load is removed to 0 mN at a speed of 2.2 mN / sec. Total deformation and plastic deformation were measured. 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 2 below. The size of the spacer was a circular shape having a diameter of about 25 μm in plan view.

A: Initial height of the spacer B: Height when a predetermined load is applied C: Height after applying the predetermined load and then removing the load Total deformation amount: Deformation amount represented by AB.

Plastic deformation amount: Deformation amount represented by AC Elastic recovery rate: Deformation rate represented by [(CB) / (AB)] × 100

[Film hardness measurement]
As the film hardness measuring device, a micro film hardness meter HM2000 (manufactured by Fisher Instruments) was used. As the indenter, a Vickers indenter was used, a load of 5 mN / μm ² was applied at a load speed of 0.25 mN / sec, the load was removed after holding for 1 second, and the Martens hardness (ISO14577) was measured. The measurement sample is a monolayer film having a thickness of 1.8 to 2.0 μm obtained by applying each colored composition to a glass substrate and hardening it. Here, the Martens hardness is a hardness calculated from a load-penetration depth curve (based on ISO14577).

The measurement results of the Martens hardness of the black matrix layer and each colored layer are shown in Table 3 below.

  As shown in Table 3, it can be seen that the relationship of the hardness of the black matrix layer ≧ the hardness of the red layer ≧ the hardness of the blue layer ≧ the hardness of the insulating layer is established. That is, the side closest to the transparent substrate is hardest, and the layer becomes softer as the distance from the transparent substrate increases. The harder the part (color layer) that is formed closer to the black matrix, the stronger the compressive load it is, and the softer the color layer close to the insulation layer and insulation layer is, the softer it is (the easier it is to secure a uniform cell gap, and adhesion) It is advantageous in the liquid crystal cell forming process such as alignment).

  When a load is applied on such a spacer, if the hardness of each layer of the spacer is in the above relationship, the cell gap can be easily maintained, and there is an effect that it is difficult to be deformed particularly when a heavy load is applied.

  The color filter according to the present embodiment can be manufactured by forming each pixel on a substrate using a colored composition (resist) of each color by a photolithography method.

  As the substrate, a glass plate having a high transmittance with respect to visible light, or a resin plate such as polycarbonate, polymethyl methacrylate, or polyethylene terephthalate is used.

  The formation of each pixel by photolithography is performed by the following method. That is, each color-colored photosensitive composition prepared as a solvent-developing or alkali-developing coloring composition that is cured by light irradiation is applied onto a transparent substrate by a coating method such as spray coating, spin coating, slit coating, or roll coating. The film is applied so that the dry film thickness is 0.5 to 3.0 μm. Next, ultraviolet exposure is performed on the dried film as necessary through a mask having a predetermined pattern arranged in contact with or non-contact with the film. Next, it is immersed in a solvent or an alkali developer or sprayed with a developer by spraying or the like to remove uncured portions, thereby forming a desired pattern.

  Then, a color filter can be manufactured by repeating the same operation for other colors. In addition, in order to accelerate | stimulate superposition | polymerization of a coloring composition, it can also heat as needed. According to the photolithography method, a color filter with higher accuracy than the printing method can be manufactured.

  In development, an aqueous solution such as sodium carbonate or sodium hydroxide is used as an alkali developer, and an organic alkali such as dimethylbenzylamine or triethanolamine can also be used. Moreover, an antifoamer and surfactant can also be added to a developing solution.

EXAMPLES The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

  In the examples and comparative examples, “parts” means “parts by weight”.

[Example 1]
The following pigments were used:

[Red Pigment 1 (R-1)]
Red Pigment 1 (CI Pigment Red 254, “IRGAPHO” manufactured by Ciba Specialty Chemicals
R RED B-CF "; R-1) was used.

[Red Pigment 2 (R-2)]
Red Pigment 2 (CI Pigment Red 177, “CROMOPH by Ciba Specialty Chemicals”
TAL RED A2B "; R-2) was used.

[Green Pigment 1 (G-1)]
500 parts of green pigment (CI Pigment Green 36, Toyo Ink Mfg. Co., Ltd. “LIONOL GREEN 6YK”; G-1), 1300 parts of sodium chloride, and 270 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) And kneaded at 70 ° C. for 3 hours. Next, this mixture is poured into about 5 liters of warm water, heated to about 70 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, then filtered and washed to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 496 parts of a salt milled pigment.

[Yellow Pigment 1 (Y-1)]
Yellow pigment (CI Pigment Yellow 138, “PALIOTOL YELLOW K0961HD” manufactured by BASF) 200
Parts, 1,500 parts of sodium chloride, and 270 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.), 1 gallon kneader (manufactured by Inoue Seisakusho) made of stainless steel, and kneaded at 60 ° C. for 6 hours. Next, this mixture is poured into about 5 liters of warm water, stirred in a high speed mixer for about 1 hour while being heated to about 70 ° C. to form a slurry, filtered, washed with water to remove sodium chloride and diethylene glycol. And dried at 80 ° C. for 24 hours to obtain 196 parts of a salt milled pigment.

[Blue Pigment 1 (B-1)]
Blue pigment 1 (CI Pigment Blue 15: 6, “LIONOL BLUE ES” manufactured by Toyo Ink Co., Ltd.) was used.

[Purple Pigment 1 (V-1)]
Purple Pigment 1 (CI Pigment Violet 23, “LIONOGEN VIOLET RL” manufactured by Toyo Ink Manufacturing Co., Ltd.) was used.

[Preparation of acrylic resin solution]
The preparation of the acrylic resin solution used in the examples will be described. The molecular weight of the resin is a weight average molecular weight in terms of polystyrene measured by GPC (gel permeation chromatography).

  A reaction vessel was charged with 370 parts of cyclohexanone, heated to 80 ° C. while injecting nitrogen gas into the vessel, and a mixture of the following monomer and thermal polymerization initiator was added dropwise at the same temperature over 1 hour to carry out the polymerization reaction. .

Methacrylic acid 20.0 parts Methyl methacrylate 10.0 parts n-Butyl methacrylate 35.0 parts 2-Hydroxyethyl methacrylate 15.0 parts 2,2'-Azobisisobutyronitrile 4.0 parts Paracmylphenol ethylene oxide modification Acrylate 20.0 parts ("Aronix M110" manufactured by Toa Gosei Co., Ltd.)
After completion of the dropwise addition, the mixture was further reacted at 80 ° C. for 3 hours, then 1.0 part of azobisisobutyronitrile dissolved in 50 parts of cyclohexanone was added, and the reaction was further continued at 80 ° C. for 1 hour, An acrylic resin solution was obtained. The weight average molecular weight of this acrylic resin was about 40,000.

After cooling to room temperature, about 2 g of the resin solution was sampled and heat-dried at 180 ° C. for 20 minutes, the non-volatile content was measured, and cyclohexanone was added to the previously synthesized resin solution so that the non-volatile content was 20 wt%. An acrylic resin solution was prepared.

[Preparation of pigment dispersion]
The mixture (weight ratio) shown in Table 4 below was uniformly stirred and mixed, then dispersed with an Eiger mill for 2 hours using zirconia beads having a diameter of 0.5 mm, filtered through a 5 μm filter, and pigment dispersion RP -1, GP-1, and BP-1.

[Preparation of colored composition]
The mixture (weight ratio) shown in Table 5 below was stirred and mixed so as to be uniform, then filtered through a 1 μm filter, and the colored compositions RR-1 (red) and GR-1 (green) for each color. ) And BR-1 (blue).

  Specific examples of the composition in Table 5 are shown below.

Monomer: Trimethylolpropane triacrylate (Shin Nakamura Chemical "NK Ester ATMPT")
Photoinitiator: 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (“Irgacure 907” manufactured by Ciba Specialty Chemicals)
Sensitizer: 4,4′-bis (diethylamino) benzophenone (“EAB-F” manufactured by Hodogaya Chemical Co., Ltd.)
Organic solvent: cyclohexanone [colored layer formation and transparent electrode formation]
Using the colored composition obtained as described above, as shown in FIG. 7, pixels of each color were formed in a region partitioned by a film thickness of 2.37 μm black matrix 12 formed in advance on the transparent substrate 11. .

That is, RR-1 which is a red coloring composition was apply | coated to the transparent substrate 11 by spin coating so that it might become a finished film thickness of 1.8 micrometers. Next, after drying at 90 ° C. for 3 minutes, the light from a high-pressure mercury lamp was irradiated at 100 mJ / cm ² through a stripe photomask for pixel formation, and developed with an alkali developer for 60 seconds. Then, it hardened | cured at 230 degreeC for 30 minutes, and the red pixel 13R was obtained. At this time, the film thickness of the red layer 16R on the black matrix 12 was 0.95 μm. The finished film thickness means the film thickness after hardening or the height of the color layer at 230 ° C. for 30 minutes.

  Next, in the same manner, the green coloring composition GR-1 was applied by spin coating so that the finished film thickness was 1.8 μm, dried at 90 ° C. for 5 minutes, and then exposed through a photomask. After development, the green pixel 13G was obtained by hardening at 230 ° C. for 30 minutes.

  Further, BR-1 which is a blue coloring composition is applied by spin coating so that the finished film thickness becomes 1.8 μm in the same manner as in the case of forming red pixels and green pixels. After drying for 5 minutes, exposure through a photomask, development, and hardening at 230 ° C. for 30 minutes, a blue film with a finished film thickness of 1.8 μm is positioned adjacent to the green pixel 13G and the red pixel 13R. Pixel 13B was formed. At this time, the film thickness of the blue layer 16B on the red layer 16R was 0.88 μm.

  In this manner, a color filter having red, green, and blue pixels on the transparent substrate 11 was obtained.

  The alkaline developer has the following composition.

Sodium carbonate 1.5% by weight
Sodium bicarbonate 0.5% by weight
Anionic surfactant (Kao Perillex NBL) 8.0% by weight
90.0% by weight of water
A transparent electrode 14 was formed to a thickness of 150 nm on the color filter formed with these three color pixels by vacuum film formation by general sputtering to obtain a color filter with a transparent electrode.

[Formation of insulating layer]
The photosensitive resin composition A for insulating layers was spin-coated on the above-mentioned color filter with a transparent electrode so that the finished film thickness was 1.4 μm, and dried at 90 ° C. for 2 minutes. Subsequently, 100 mJ / cm < ² > of the light of the high pressure mercury lamp was irradiated through the photomask for spacer formation. At this time, the exposure (exposure gap) between the photomask and the substrate was set to 100 μm. Thereafter, development is performed using the same developer as that for producing the color filter, followed by washing with water and post-baking at 230 ° C. for 30 minutes to form the insulating layer 15 on the transparent electrode 14 above the black matrix 12. did.

  The resin composition constituting the insulating layer 15 may be either positive or negative, and is not limited to resin materials such as acrylic resin, epoxy resin, and polyimide resin.

  The liquid crystal alignment control protrusions 17 can be formed at the same time by using the photomask on which the insulating layer 15 is manufactured, and are arranged at the center of each pixel. The finished film thickness of the spacer was 3.95 μm. The cell gap of the target vertical alignment (VA) liquid crystal is 3.8 μm, and the margin due to the weighted load when forming a panel is 0.15 μm.

  As described above, a color filter as shown in FIG. 7 was obtained.

  The elastic recovery rate of the spacer of this example was as large as 94.0%, and only plastic deformation of about 0.04 μm remained, which was preferable as a cell gap control spacer of a liquid crystal display device.

[Production of liquid crystal display devices]
After an alignment film made of polyimide was formed on the color filter obtained as described above, a liquid crystal for vertical alignment was sealed as a liquid crystal display device by laminating a TFT substrate with an epoxy resin as a sealing material. In the obtained liquid crystal display device, since uniform intervals were maintained over the entire display surface, there were no defects or color unevenness, and good display characteristics were obtained.

[Example 2]
Similarly to Example 1, on the transparent substrate 21 on which the black matrix 22 was formed, a red pixel 23R, a red layer 26R, a green pixel 23G, a blue pixel 23B, and a blue layer 26B were formed. In this embodiment, the film thickness of the black matrix 22 is 1.8 μm.

  On the substrate on which the pixels of these three colors were formed, the transparent electrode 27 was formed to a thickness of 230 nm by vacuum film formation by general sputtering.

  Next, the width of the central portion of the transparent electrode 25 on the spacer and the red pixel 23R, the green pixel 23G, and the blue pixel 23B are each 3 μm wide by a known photolithography technique using a positive photoresist. The portion of the transparent electrode 25 having a length of 20 μm was removed by etching. The opening 30 of the transparent electrode 24 formed at the center of each pixel can be used for vertical alignment control called VA. The shape of the opening 30 may be any of a cross shape, a plurality of cross shapes, a rice character shape, an L shape, a dogleg shape, a straight line, and a circle shape, or a combination thereof.

  As described above, a color filter as shown in FIG. 8 was obtained.

  The elastic restoring rate of the spacer of this example was as large as 94.1%, and only plastic deformation of about 0.03 μm remained, which was preferable as a spacer for controlling the cell gap of the liquid crystal display device.

  An alignment film made of polyimide was formed on the color filter, and then bonded to the TFT substrate using an epoxy resin as a sealing material, and a liquid crystal for vertical alignment was sealed as a liquid crystal to obtain a liquid crystal display device. In the obtained liquid crystal display device, since uniform intervals were maintained over the entire display surface, there were no defects or color unevenness, and good display characteristics were obtained.

[Example 3]
A color filter as shown in FIG. 9 was obtained in the same manner as in Example 1 except that the transparent electrode and the liquid crystal alignment control protrusion were not provided.

  The insulating layer 35 has a thickness of 1.50 μm, the black matrix 31 has a thickness of 1.8 μm, the red layer 36R on the black matrix 31 has a thickness of 0.95 μm, the blue layer 36B has a thickness of 0.90 μm, a spacer The finished film thickness was 3.35 μm.

  The elastic restoring rate of the spacer of this example was as large as 94.1%, and only plastic deformation of about 0.03 μm remained, which was preferable as a spacer for controlling the cell gap of the liquid crystal display device.

  An IPS mode liquid crystal display device was obtained using the color filter obtained as described above. The cell gap of the IPS liquid crystal targeted for the obtained liquid crystal display device was 3.2 μm, and the weighted load margin at the time of panel formation was 0.15 μm. In this liquid crystal display device, since uniform intervals are maintained over the entire display surface, there are no defects or color unevenness, and good display characteristics are obtained.

[Comparative example]
In the same process as in Example 1, each color pixel was formed in a region partitioned by the black matrix 12 having a thickness of 2.77 μm formed in advance on the transparent substrate 11.

That is, RR-1 which is a red coloring composition was applied to the transparent substrate 11 by spin coating so that the finished film thickness was 1.8 μm. Next, after drying at 90 ° C. for 3 minutes, light from a high-pressure mercury lamp was irradiated through a stripe-shaped photomask for forming pixels at 100 mJ / cm ² and developed with an alkali developer for 60 seconds to obtain red pixels 13R. Thereafter, the film was hardened at 230 ° C. for 30 minutes, and the film thickness of the red layer 16R on the black matrix was 0.95 μm.

  In this comparative example, the green layer which becomes a part of the spacer was formed on the red layer simultaneously with the green pixel using the green coloring composition. That is, GR-1 which is a green coloring composition is applied by spin coating so that the finished film thickness is 1.8 μm, dried at 90 ° C. for 5 minutes, exposed through a photomask, and developed. A green pixel 13G was obtained. Then, when it hardened | cured for 30 minutes at 230 degreeC, the film thickness of the green layer on a black matrix became 0.85 micrometer.

  Further, BR-1 which is a blue coloring composition is applied by spin coating so that the finished film thickness becomes 1.8 μm in the same manner as in the case of forming red pixels and green pixels, and at 90 ° C. for 5 minutes. After drying, the green pixel 13G was obtained by exposing and developing through a photomask. Then, when it hardened | cured for 30 minutes at 230 degreeC, the film thickness of the blue layer on a black matrix became 0.82 micrometer.

  Thus, a color filter having red, green and blue three-color pixels on the transparent substrate 11 and a red, green and blue three-color colored layer on the black matrix 12 was obtained.

  The transparent electrode 14 was formed to a thickness of 150 nm on the color filter on which the pixels of these three colors were formed by vacuum film formation by general sputtering.

  Subsequently, the photosensitive resin composition A for insulating layers was spin-coated on the above-mentioned color filter with a transparent electrode so as to have a finished film thickness of 0.8 μm, and dried at 90 ° C. for 2 minutes. Next, the film was exposed to light from a high-pressure mercury lamp through a photomask for forming a spacer, and then developed and hardened similarly to the example to form an insulating layer 15.

  After an alignment film made of polyimide was formed on the color filter thus obtained, the TFT substrate was bonded with an epoxy resin as a sealing material to enclose liquid crystal for vertical alignment as liquid crystal. The obtained liquid crystal display device had color unevenness which seems to be an influence of the alignment shift of the spacers in which the three colors were overlapped. In addition, after the liquid crystal was sealed, some fine bubbles could be generated at the edges and corners of the effective screen.

  The elastic recovery rate of the spacer of this comparative example was as small as 92.1%, and plastic deformation of about 0.23 μm remained, which was not preferable as a cell gap control spacer of a liquid crystal display device.

The characteristic view which shows the change of the transmittance | permeability by the wavelength of a red layer. The characteristic view which shows the change of the transmittance | permeability by the wavelength of a blue layer. The characteristic view which shows the change of the transmittance | permeability by the wavelength of a green layer. The characteristic view which shows the change of the transmittance | permeability by a wavelength when a red layer and a blue layer are piled up. The characteristic view which shows the change of the transmittance | permeability by a wavelength when a red layer and a green layer are accumulated. The characteristic view which shows the change of the transmittance | permeability by a wavelength when a green layer and a blue layer are piled up. FIG. 3 is a cross-sectional view illustrating a color filter for a liquid crystal display device according to the first embodiment. FIG. 6 is a cross-sectional view illustrating a color filter for a liquid crystal display device according to a second embodiment. FIG. 6 is a cross-sectional view illustrating a color filter for a liquid crystal display device according to a third embodiment. The figure which shows the position where a spacer is formed. The figure which shows the position where a spacer is formed.

Explanation of symbols

  11, 21, 31 ... black matrix, 12, 22, 32 ... transparent substrate, 13R, 23R, 33R ... red pixel, 13B, 23B, 33B ... blue pixel, 13G, 23G, 33G ... green pixel, 16R, 26R, 36R ... red layer, 16B, 26B, 36B ... blue layer, 14, 24 ... transparent electrode (ITO film), 15, 25, 35 ... insulating layer, 17 ... projection for controlling liquid crystal alignment.

Claims (11)

  A black matrix layer formed on the transparent substrate; a plurality of colored pixels formed in a pixel region on the transparent substrate partitioned by the black matrix layer; and a spacer formed on the black matrix layer. A color filter for a liquid crystal display device, wherein the spacer includes a laminate composed of a red layer, a blue layer, and an insulating layer.   2. The color filter for a liquid crystal display device according to claim 1, wherein the spacer includes a laminate composed of two layers and an insulating layer in which a red layer and a blue layer are stacked in this order on a black matrix layer.   The hardness of the layer constituting the spacer has a relationship of hardness of the black matrix layer ≧ hardness of the red layer ≧ hardness of the blue layer ≧ hardness of the insulating layer. Any one of the color filters for a liquid crystal display device       The colored pixels of the plurality of colors include a plurality of pixel units each including a red pixel, a green pixel, and a blue pixel, and one spacer exists per pixel unit. The color filter for liquid crystal display devices in any one of 1-3.   The color filter for a liquid crystal display device according to any one of claims 1 to 4, wherein the spacer is disposed in an adjacent portion between the red pixel and the blue pixel.   The insulating layer has a total deformation amount of 0.2 μm to 0.5 μm when a compressive load of 20 mN / piece is applied from the height direction, and a compressive load of 60 mN / piece is applied to remove the load. The color filter for a liquid crystal display device according to any one of claims 1 to 5, wherein the plastic deformation amount when it is applied is 0.01 µm to 0.1 µm.   The spacer has a total deformation amount of 0.22 μm to 0.53 μm when a compressive load of 20 mN / piece is applied in the height direction, and when the load is removed by applying a compressive load of 60 mN / piece. The color filter for a liquid crystal display device according to claim 1, wherein the plastic deformation amount of the liquid crystal display device is 0.01 μm to 0.1 μm.   The liquid crystal alignment control protrusion is provided on the colored pixel formed in the pixel region, and the height of the insulating layer is equal to or lower than the height of the liquid crystal alignment control protrusion. The color filter for liquid crystal display devices in any one.   The color filter for a liquid crystal display device according to claim 1, wherein a transparent electrode is provided on the colored pixel and the colored layer, and the insulating layer is formed on the transparent electrode.   The color filter for a liquid crystal display device according to any one of claims 1 to 9, further comprising a transparent electrode having an opening at a central portion of the pixel on the colored pixel excluding the spacer portion.   A liquid crystal display device comprising the color filter for a liquid crystal display device according to claim 1.

Images