JP5478157B2 - Substrate for liquid crystal display device and liquid crystal display device - Google Patents

Description

  The present invention relates to a photosensitive resin composition, a substrate for a liquid crystal display device using the same, and a liquid crystal display device, and in particular, a vertical alignment type liquid crystal display (VA-LCD) and an alignment division vertical alignment type liquid crystal display (MVA-). Photosensitive resin composition for forming structures such as alignment control protrusions and spacers included in LCD), and liquid crystal display device including structures such as alignment control protrusions and spacers formed by this photosensitive resin composition The present invention relates to a substrate for a liquid crystal display device and a liquid crystal display device including the substrate for a liquid crystal display device.

  MVA type LCDs (for example, see Patent Documents 1 and 2 and Non-Patent Document 1) are controlled so that the tilt directions of liquid crystal molecules are in a plurality of directions within one pixel, and uniform halftone display is possible in all directions. The vertical alignment type liquid crystal display device as described above has excellent contrast, viewing angle characteristics, and response speed.

  FIG. 4 is a cross-sectional view schematically showing the operation of the MVA-LCD. As shown in FIG. 4, in the liquid crystal display device 40, an array substrate 41 having active elements for driving liquid crystals and a color filter substrate 42 having colored pixels are arranged to face each other, and liquid crystal molecules 43 are interposed therebetween. It has the structure which clamped. The array substrate 41 is formed by forming a transparent conductive film 45a on a translucent substrate 44a, and the color filter substrate 42 is formed by a black matrix (not shown) and a colored layer (not shown) on the translucent substrate 44b. And a transparent conductive film 45b. The colored layer includes red pixels, green pixels, and blue pixels.

  An alignment control projection 48 is provided on the transparent conductive film 45 a of the array substrate 41 and the transparent conductive film 45 b of the color filter substrate 42. In addition, a spacer 49 is provided on the transparent conductive film 45b of the color filter substrate 42 to maintain the distance between the substrates. In FIG. 4, the alignment film, the polarizing plate, and the retardation plate are not shown.

  FIG. 4A shows a state when no voltage is applied. From FIG. 4A, the liquid crystal molecules 43 are vertically aligned between the two substrates when no voltage is applied, but the liquid crystal molecules near the alignment control protrusions 48 are slightly inclined due to the influence of the inclined surfaces of the protrusions. Recognize.

  FIG. 4B shows a state when a voltage is applied. When a voltage is applied, the liquid crystal molecules on the inclined surface of the alignment control protrusion 48 begin to be inclined, and the liquid crystal molecules other than the inclined portion are sequentially aligned in the same manner. . That is, the alignment of the liquid crystal molecules can be controlled by providing the protrusions.

  The alignment control protrusion 48 and the spacer 49 are structures having different heights. Usually, in order to form structures having different heights by a photolithography technique, two photolithography processes are required. In general, a positive resist is used to form the alignment control protrusions, a negative resist is used to form the spacers, and two types of photomasks are used. This method is excellent in terms of sensitivity and patterning characteristics. However, since the resist materials are different, it is necessary to prepare them in separate steps. Therefore, since both a positive type resist and a negative type resist are used, the number of steps such as replacement of the resist solution and developer increases, time and cost increase, and reduction thereof becomes a problem. Alternatively, it is necessary to provide a new production line.

  In order to solve these problems, a method of forming alignment control protrusions and spacers together has been proposed (see, for example, Patent Document 3). As this method, for example, a method of making a difference in exposure amount by performing multiple exposures (see, for example, Patent Document 4), a spacer column forming portion in advance by overlapping at least two of the colored pixel layer and the light shielding layer. (For example, see Patent Document 5), a method in which two photosensitive resin composition layers having different photosensitivity are stacked and exposed using a wavelength selective mask (for example, see Patent Document 6), etc. It has been reported.

  However, in any of these methods, the number of exposures is two times or more, so that alignment during exposure is difficult, and it is difficult to maintain the height accuracy of the spacer columns in order to overlap the colored pixel layers. There are problems such as an increase in the process of forming the photosensitive resin composition layer. In order to solve these problems, a method of exposing with a wavelength selective mask using one kind of photosensitive resin composition (for example, see Patent Document 7) has been proposed. If a voltage is applied for a long time, an afterimage may occur), which causes the display quality to deteriorate significantly. This problem is caused by the electrical characteristics (dielectric loss tangent) of the photosensitive resin composition, and its improvement is an important issue.

Japanese Patent No. 2947350 Japanese Patent Laid-Open No. 11-248921 Japanese Patent Laid-Open No. 2001-201750 JP 2002-236371 A Japanese Patent No. 3255107 JP 2003-248323 A JP 2006-119327 A

Electronic Journal October 1997 P.I. 33

  The present invention has been made in view of the above circumstances, and by simplifying the formation process of structures having different heights, the time and cost are greatly reduced, and even when a voltage is applied for a long time, seizure is caused. Photosensitive resin composition that makes it possible to obtain a liquid crystal display device having excellent display quality that does not occur, and a substrate for a liquid crystal display device comprising structures having different heights formed from this photosensitive resin composition An object of the present invention is to provide a liquid crystal display device including the liquid crystal display device substrate.

  As a result of intensive studies in order to solve the above problems, the present inventors contain an alkali-soluble resin, a photopolymerization initiator, a photopolymerizable monomer, and a predetermined epoxy resin, and limit the amount of the epoxy resin to a predetermined range. It has been found that by using a negative photosensitive resin composition, a spacer having a low dielectric loss tangent value and an alignment control protrusion can be formed simultaneously, and the present invention has been completed.

That is, a first aspect of the present invention, on a transparent substrate, a black matrix, planarization layer, a transparent conductive film, and Ri Na to form different structures heights, different structures of the height and a liquid crystal display device substrate formed by using a sensitive light-sensitive resin composition, the photosensitive resin composition, an epoxy resin, a polyfunctional polymerizable monomer and a photopolymerization with the alkali-soluble resin, an aromatic ring structure An initiator, and the amount of the epoxy resin relative to the total solid content of the photosensitive resin composition is 10% by weight to 40% by weight, and the epoxy resin is 2- [4- (oxira Nylmethoxy) phenyl] -2- [4- [1,1-bis [4- (oxiranylmethoxy) phenyl] ethyl] phenyl] propane, wherein the structures having different heights are 0.0094 or less It has a dielectric loss tangent and its bullet To provide a liquid crystal display device substrate, wherein the recovery ratio is within the range of 58% to 73%.

According to a second aspect of the present invention, there is provided a liquid crystal display device comprising the liquid crystal display device substrate.

  According to the photosensitive resin composition of the present invention, the process of forming structures having different heights is simplified to significantly reduce time and cost, and seizure occurs even when a voltage is applied for a long time. It is possible to obtain a liquid crystal display device having excellent display quality.

1 is a cross-sectional view of a liquid crystal display device according to a first embodiment of the present invention. Sectional drawing of the liquid crystal display device which concerns on the 2nd Embodiment of this invention. Sectional drawing of the liquid crystal display device which concerns on the 3rd Embodiment of this invention. Sectional drawing for demonstrating operation | movement of the liquid crystal display device in which the protrusion for alignment control and the spacer were formed.

  Hereinafter, various modes for carrying out the present invention will be described. However, the following description is an example (representative example) of the embodiment of the present invention, and the present invention includes these contents as long as the gist of the present invention is not exceeded. It is not limited.

  A substrate used for an alignment-divided vertical alignment liquid crystal display (MVA-LCD) is formed by forming a transparent protective layer as a flattening layer on a normal color filter pixel as necessary, and further forming a transparent conductive film thereon. In general, it has a structure in which alignment control protrusions and spacers are formed. In this case, the height of the alignment control protrusion is usually 2/3 or less of the height of the spacer in order to obtain a good alignment effect. In order to form the alignment control protrusions and spacers having different heights, usually, the alignment control protrusions are first formed using a positive resist, and then the spacers are formed using a negative resist.

  However, in this method, it is necessary to repeat the photolithography process twice, and further, when manufacturing in the same line, it is necessary to replace the resist and developer and to clean the line. . Therefore, simplification of the process has been strongly desired from the viewpoint of cost reduction. Further, if the alignment control protrusion and the spacer can be formed of the same resist, the amount of the chemical solution to be discarded can be reduced to about half, which is environmentally superior. Note that a resin material having high heat resistance and transparency, such as an acrylic resin, can be used for the planarizing layer.

  As a method for satisfying such a requirement, the present inventors have exposed a single-layer photosensitive resin composition layer of a predetermined composition formed on a substrate through a photomask, developed, and aligned. When forming control protrusions and spacers, a photomask having two or more transmissive patterns is used as the photomask, so that it is formed on the light shielding layer excluding the pixel portion (display portion using light transmission). It has been found that the alignment control protrusion and the spacer can be formed with high accuracy simultaneously in one photolithography process. In this case, the photosensitive resin composition contains an alkali-soluble resin, an epoxy resin having an aromatic ring structure, a polyfunctional polymerizable monomer, and a photopolymerization initiator, and the amount of the epoxy resin relative to the total solid content of the photosensitive resin composition Is 10% to 40% by weight. Note that a color filter using a color material such as an organic pigment is formed in the pixel portion.

  Hereinafter, in the present specification, a liquid crystal display device substrate in which a colored pixel portion is provided on a translucent substrate and an alignment control protrusion and a spacer are formed thereon will be mainly described. However, the present invention is not limited to this. Absent. That is, the alignment control protrusions and spacers are not limited to the color filter substrate, but can be provided on the array substrate facing the color filter substrate, and the black substrate facing the COA structure substrate on which the color filter is formed on the array substrate. It can also be provided on the matrix substrate. In short, it is only necessary that the orientation control projection is provided on at least one of the substrates and a spacer is interposed between the two substrates.

  It does not mean that the liquid crystal display substrate or the liquid crystal display device according to the present invention must include a colored pixel portion.

  The substrate that can be used for the substrate for a liquid crystal display device according to the present invention is preferably a light-transmitting plate, such as glass, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyethersulfone, or polyacrylate. Examples of the plastic sheet or film.

  In addition, a light-transmitting substrate such as glass having excellent heat resistance is preferable because a heating process is performed after forming alignment control protrusions and spacers having different heights, and the coefficient of thermal expansion is small. It is preferable to select a glass substrate having excellent dimensional stability in the heating step.

  In general, a color filter substrate is formed by forming a black matrix (light-shielding layer) for improving contrast on a light-transmitting substrate such as a light-transmitting glass, and then red pixels (R) and green pixels (G). The colored pixel portion of the blue pixel (B) is formed, and further, a transparent conductive layer and an alignment film layer are sequentially laminated. This color filter substrate is disposed so as to face a counter substrate on which a semiconductor element array such as a thin film transistor is formed, and a liquid crystal layer is interposed therebetween to constitute an LCD.

  In this specification, the colored pixel portions of red pixels, green pixels, and blue pixels are collectively referred to as a color filter. Note that a structure in which at least a black matrix, a red pixel (R), a green pixel (G), and a blue pixel (B) are provided over a light-transmitting substrate made of glass or the like is referred to as a color filter substrate in this specification. .

  For the purpose of improving the contrast of the liquid crystal display device, the black matrix that requires light shielding properties can be formed using a known method. As such a method, for example, a thin film of a metal or metal oxide such as chromium or titanium is formed on a substrate by a method such as sputtering, and is patterned by a technique such as etching, or photosensitive. The resin composition is mixed with light-shielding fine particles such as carbon black and metal oxide, or a color material such as pigments or dyes composed of a plurality of types, and this is formed as a black photosensitive resin composition layer on the substrate, and photo Examples of the method include forming by patterning using a lithography method, but any method may be used in the present invention.

  Examples of the black colorant that can be used in the photosensitive resin composition for forming the black matrix include carbon black, graphite, iron black, aniline black, cyanine black, and titanium black. Among these, carbon black is preferable in terms of light shielding properties, image characteristics, and the like.

  Specific examples of carbon black include, for example, trade names “MA7”, “MA8”, “MA11”, “MA100”, “MA220”, “MA230”, “# 52”, “# 50” manufactured by Mitsubishi Chemical Corporation, “# 47”, “# 45”, “# 2700”, “# 2650”, “# 2200”, “# 1000”, “# 990”, “# 900”, etc .; trade name “Printex95” manufactured by Tegusa , "Printex90", "Printex85", "Printex75", "Printex55", "Printex45", "Printex40", "Printex30", "Printex3", "PrintexA", "PrintexG", "BleSp" , "Special Blac “K250”, “Special Black 100”, etc .; trade names “Monarch 460”, “Monarch 430”, “Monarch 280”, “Monarch 120”, “Monarch 800”, “Monarch 4630”, “REGAL99R”, “GALG99R”, “GAL99R”, “GAL99R”, “GAL99R”, “GAL” , “REGAL415R”, “REGAL250”, “REGAL250R”, “REGAL330”, “BLACK PEARLS480”, “BLACK PEARLS130” and the like; ”,“ Raven40 ”,“ Raven410 ”,“ Raven420 ”,“ Raven450 ”,“ R ” AVEN500 ”,“ Raven780 ”,“ Raven850 ”,“ Raven890H ”,“ Raven1000 ”,“ Raven1020 ”,“ Raven1040 ”, and the like. An organic pigment may be added to these for the purpose of toning.

  The colored pixel portion is provided in the opening of the black matrix described above, and a pixel pattern composed of the three primary colors of red pixel (R), green pixel (G), and blue pixel (B) is usually arranged in a desired shape. It is a thing. Examples of the forming method include known methods such as a pigment dispersion method, a dye method, an electrodeposition method, a printing method, a transfer method, and a method of forming each pixel by inkjet. In the present invention, it may be formed by any method, and it is desirable to use a heat-resistant organic pigment as the coloring material.

  In the present invention, the configuration of the substrate having the alignment control protrusion and the spacer includes a configuration in which the alignment control protrusion and the spacer are provided on the color filter or the transparent conductive film, the color filter, the transparent conductive film, the alignment control protrusion, and A structure in which a spacer and an alignment film layer are formed in this order, or a structure in which a protective layer that is a planarization layer is provided between any of these layers can be given.

  The transparent conductive film is an essential member for at least one of a pair of opposed substrates that sandwich the liquid crystal layer of the liquid crystal display device. Usually, it is formed directly under an alignment film or alignment protrusion that regulates the alignment direction of the liquid crystal molecules, and controls the behavior of the liquid crystal molecules between the substrates by transmitting an electrical signal. Alternatively, it may be provided on the alignment control protrusion by vapor deposition or the like.

As the transparent conductive film, a material that is transparent and conductive and can be formed into a thin film is used, and an ITO (complex oxide of indium and tin) film is usually used. In addition, an IZO (indium and zinc composite oxide) film, an IGZO film in which gallium oxide is added to this film, and a SnO ₂ (tin dioxide) film can also be used. It can be formed by such a method.

  Next, a method for forming alignment control protrusions and spacers will be described.

  First, the above-described photosensitive resin composition is coated on a translucent substrate. Or if necessary, it coats on the board | substrate with which the color filter, the planarization film | membrane, and the transparent conductive film were formed as above-mentioned. For coating the photosensitive resin composition, a known coating method such as a bar coater, applicator, wire bar, spin coater, roll coater, slit coater, curtain coater, die coater, or comma coater can be used. Alternatively, the photosensitive resin composition may be formed into a dry film by a known method, and this may be transferred onto a substrate using a laminator and laminated.

  Next, pattern exposure is performed by irradiating light through a wavelength selective mask having a plurality of patterns, or a photomask having a plurality of patterns having different transmittances, and then developing is performed to dissolve and remove unnecessary portions. The alignment control protrusion and the spacer are formed in a lump.

  The height of the spacer column may be in the range of 2.0 to 5.0 μm, which is the gap between the color filter substrate and the facing array substrate. On the other hand, if the size of the alignment control protrusion is excessively large, liquid crystal alignment is hindered, and it is difficult to obtain a sufficient viewing angle and unevenness due to liquid crystal alignment defects is likely to occur. When the height of the alignment control protrusion is 2/3 or less of the height of the spacer, a relatively good alignment effect can be obtained.

  The wavelength-selective mask used in the present invention is a photomask characterized by having at least one kind of semi-transmissive part in addition to the light complete transmission part and the complete light-shielding part. The semi-transmission part here is a part having a transmittance which varies depending on the wavelength in the wavelength range of 300 to 450 nm. In general, a chromium (Cr) thin film is used as a complete light-shielding portion of a photomask. For example, the film thickness of the chromium (Cr) thin film is partially further reduced, or a chromium (Cr) thin film is formed in a halftone dot pattern. When the pattern is formed, only that portion passes a little light. However, in this case, since the transmittance changes almost uniformly in the range of 300 to 450 nm, there is no selectivity of the exposure wavelength even if the exposure amount can be controlled. Therefore, even if the height of the resist pattern obtained can be controlled, the shape cannot be controlled.

  On the other hand, if an ITO thin film, a compound thin film containing Ti or W, or a compound thin film containing Ti or Mo is used instead of the Cr thin film as a material for forming the semi-transmissive part, a semi-transmissive part having different transmittance depending on the wavelength is formed. can do. The wavelength selectivity of these thin films can be controlled depending on the material and the formation process, and thereby it is possible to collectively form resist patterns having different shapes as well as heights.

  In this way, by using a wavelength selective mask formed by combining a light transmissive part and a semi-transmissive part in accordance with the height and shape of a pattern to be formed, patterns having different heights and shapes can be obtained in one exposure. Formation is possible. Specifically, when the photosensitive resin composition is a negative type, the spacer column forming part is a completely light transmitting part, the alignment control protrusion forming part is a semi-transmitting part, and the part where nothing is left is a completely light shielding part. When the wavelength selective mask is used, the spacer forming portion is completely cured up to the upper part of the photosensitive resin composition layer, so that a columnar resist pattern that is almost faithful to the mask pattern is formed. A semicircular pattern having a lower height is formed. Further, by using a photomask having two or more types of patterns having different transmittance characteristics, it is possible to collectively form alignment control protrusions having partially changed shapes and heights.

  As the light source for exposure, a light source that emits light having a wavelength of 300 to 450 nm, for example, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, a halogen lamp, or the like can be used. After exposure, an image faithful to the mask pattern can be obtained by developing with a predetermined developer. As the developer, an organic solvent system or an aqueous alkali system is generally used, but an aqueous alkaline system is preferable from the viewpoint of ensuring work safety and environmental safety, and an inorganic alkaline system is particularly preferable. However, in the case of a color filter on array structure (COA) in which a color filter is formed on an array substrate in which TFT elements are arranged in a matrix, Na and K ions in an inorganic alkaline aqueous solution cause contamination. It is preferable to use an organic alkali developer. These can also be mixed with various known additives such as surfactants.

  In the present invention, by performing a heating step after the photolithography step, curing of the alignment control protrusion and the spacer is promoted, adhesion to the substrate is improved, and solvent resistance and chemical resistance are imparted. Can do. In addition, the alignment control protrusions cured at the semi-transmission part have a slightly lower curability than the spacers cured at the light complete transmission part, so the shape becomes smooth due to heat shrinkage and reflow, and the liquid crystal molecules The orientation can be further improved. The heating step may be carried out at a temperature and time at which the thermosetting component sufficiently reacts in a hot plate, a hot air furnace, a far-infrared furnace or the like, for example, at 200 to 250 ° C. for 15 to 100 minutes.

  Here, the alignment control protrusion is formed on the colored pixel layer of the color filter, on the planarizing layer disposed on the black matrix, or on the transparent conductive film, and the shape thereof is a dot shape, a stripe shape, It is preferable to have regularity such as a zigzag shape, and the cross section of the protrusions is preferably a semicircular shape, a semi-elliptical shape, or a polygonal shape such as a triangle, but is rounded. Alternatively, it may be a cone, a pyramid, or a trapezoid.

  The spacer is formed on the transparent conductive film on the light shielding layer excluding the colored pixel layer of the color filter or at a position corresponding to the light shielding layer of the counter substrate such as an array substrate, and the shape thereof is a cylinder or a plan view. Polygonal columns are common. The spacers and the alignment control protrusions may be formed by changing the height to a plurality of types in the color filter, the black matrix, or the light reflection part (the part where light is used as reflection instead of transmission).

  An alignment film layer may be provided separately from the alignment control protrusion on one side of the substrate facing the substrate for a liquid crystal display device according to the present invention, or on the inner surface of both substrates. For the alignment film layer, a negative liquid crystal compound is vertically aligned and a transparent and insulating material is used. Usually, a polyimide resin is used. A polyimide resin solution, a polyamic acid solution, or the like is formed by a known coating method or printing method, and then hardened by heat treatment or the like.

  The protective layer provided as necessary is for flattening a step generated when the light shielding layer and the colored pixel layer are formed, or preventing components contained in the light shielding layer and the colored pixel layer from being mixed into the liquid crystal layer. Therefore, transparency is required. As a material for forming the protective layer, photocurable, thermosetting, light and thermosetting resin compositions, resin cured products such as epoxy, acrylic and polyimide, or inorganic compounds formed by sputtering or vapor deposition, etc. Any material that can achieve the above-described object may be used. The film thickness of the protective layer can be set to 0.5 to 3 μm in consideration of the surface state of the color filter layer.

  Hereinafter, each component of the photosensitive resin composition of this invention is demonstrated.

<Alkali-soluble resin>
Examples of the alkali-soluble resin used in the photosensitive resin composition of the present invention include acrylic resins and novolac resins. The alkali-soluble resin used in the photosensitive resin composition of the present invention preferably has an acid value of 20 to 180 in terms of solid content, more preferably 35 to 150. If the acid value of the resin is less than 20, there is a risk of developing failure in alkali development, and if the acid value is greater than 180, problems such as the surface of the exposed portion being eroded by the developer are liable to occur in alkali development. .

  Examples of the acrylic-modified resin that is an example of the alkali-soluble resin used in the photosensitive resin composition of the present invention include carboxylic acid-containing monomers such as acrylic acid and methacrylic acid, methyl (meth) acrylate, and ethyl (meth). Aromatic ring-containing (male) tacrylates such as acrylate, propyl (meth) acrylate, butyl (meth) acrylate, alkyl (mea) tacrylates such as lauryl (meth) acrylate, benzyl (meth) acrylate, paracumylphenol EO modified acrylate, etc. Hydroxyl-containing (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, etc. Acrylates, styrene, cyclohexyl maleimide, (co) polymers with compounds such as phenyl maleimide.

  In addition, by adding an epoxy-containing acrylate such as glycidyl (meth) acrylate to these resins, or by adding methacryloyloxyethyl (meth) acrylate to a copolymer of a hydroxyl group-containing (meth) acrylate, I can do it.

  Examples of the novolak resin include resins obtained by adding acrylic acid to a cresol novolac epoxy resin such as EPPN-501H and EPPN-502H (manufactured by Nippon Kayaku Co., Ltd.) and then adding an acid anhydride.

<Polyfunctional polymerizable monomer>
Examples of the polyfunctional photopolymerizable monomer used in the photosensitive resin composition of the present invention include monomers containing a hydroxyl group such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate, and ethylene glycol diester. (Meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tetramethylene glycol di (meth) acrylate, bisphenol A type EO adduct diacrylate, trimethylol Propane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tet (Meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, polyfunctional (meth) acrylate esters such as glycerol (meth) acrylate. These can be used alone or in combination of two or more.

<Epoxy resin having aromatic ring structure>
The photosensitive resin composition of the present invention contains an epoxy resin having an aromatic ring structure as an essential component. Specific examples of the epoxy resin having an aromatic ring structure include 2- [4- (oxiranylmethoxy) phenyl] -2- [4- [1,1-bis [4- (oxiranylmethoxy) phenyl] ethyl. ]] Phenyl] propane, and as commercially available products, Techmore VG3101 (manufactured by Printec Co., Ltd.) and the like can be mentioned.

  It is preferable that the compounding quantity of the epoxy resin which has an aromatic ring structure is 10 to 40 weight% with respect to the total solid of alkali-soluble resin, a polyfunctional polymerizable monomer, a photoinitiator, and an epoxy resin. When the blending amount of the epoxy resin with respect to the total solid content is less than 10% by weight, the dielectric loss tangent of the formed alignment control protrusion and spacer is increased, and image burn-in occurs. If it exceeds 40% by weight, it is difficult to provide a predetermined difference in height between the alignment control protrusion and the spacer.

<Solvent>
Examples of the solvent component that can be used in the photosensitive resin composition of the present invention include alcohols, phenols, glycols, glycol ethers, ethers, esters, ketones, acetates, aromatic hydrocarbons, halogens, and the like. Hydrocarbons, nitriles, amides and the like. Among these, alcohols, glycols, glycol ethers, ethers, esters, ketones, and acetates are preferable, and glycol ethers and ether acetates are particularly preferable.

  Specifically, ethanol, propanol, butanol, propylene glycol, butanediol, diethylene glycol, triethylene glycol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, benzyl alcohol, ethylene glycol mono-n-butyl ether, propylene glycol monomethyl ether, Propylene glycol mono-n-butyl ether, propylene glycol-t-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, carbitol, 3-ethoxy Ethyl propionate, propylene glycol Nomethyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, ethylene glycol mono-n-butyl ether acetate, ethylene glycol diacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, Diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether acetate, diisopropyl ether, mineral spirit, n-pentane, amyl ether Le, ethyl caprylate, n- hexane, diethyl ether, isoprene, ethyl isobutyl ether, n- octane, diisobutylene, Apuko thinner, butyl ether, diisobutyl ketone, methyl cyclohexene, methyl nonyl ketone, propyl ether, dodecane, Sokal Solvent No. 1 and no. 2, amyl formate, dihexyl ether, diisopropyl ketone, dihexyl ether, diisopropyl ketone, Solvesso # 150, (n-, sec-, t-) butyl acetate, hexene, shell TS28 solvent, butyl chloride, ethyl amyl ketone, ethyl benzoate , Amyl chloride, ethylene glycol diethyl ether, ethyl orthoformate, methoxymethyl pentanone, methyl butyl ketone, methyl hexyl ketone, methyl isobutyrate, benzonitrile, ethyl propionate, methyl isoamyl ketone, methyl isobutyl ketone, propyl acetate , Amyl acetate, amyl formate, bicyclohexyl, dipentene, methyl amyl ketone, methyl isopropyl ketone, propyl propionate, Methyl ethyl ketone, ethyl cellosolve acetate, cyclohexanone, ethyl acetate and the like.

  Among these solvents, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether acetate, and cyclohexanone are preferable.

  Although the said solvent may be used individually by 1 type, you may use 2 or more types of solvents together as needed.

<Photopolymerization initiator>
Examples of the photopolymerization initiator used in the photosensitive resin composition of the present invention include acetophenone, 2,2′-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, Acetophenones such as p-tert-butylacetophenone, benzophenone, 2-chlorobenzophenone, benzophenones such as p, p'-bisdimethylaminobenzophenone, benzoin such as benzyl, benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether Ethers, benzyldimethyl ketal, thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2-methylthioxanthone, 2-isopropylthio Sulfur compounds such as xanthone, 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) Triazines such as -6-triazine, organic peroxides such as azobisisobutyronitrile, benzoyl peroxide, cumene peroxide, thiols such as 2-mercaptobenzoimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole Compounds and the like. These photopolymerization initiators can be used alone or in combination of two or more.

  In addition, the photosensitive resin composition of the present invention does not function as a photopolymerization initiator alone, but a compound that increases the ability of the photopolymerization initiator when used in combination with the photopolymerization initiator is photopolymerized. It can be added as an initiation aid. Examples of such compounds include tertiary amines such as triethanolamine that are effective when used in combination with benzophenone.

  The addition amount of the photopolymerization initiator is preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the resin. If the amount is less than 0.1 parts by weight, the photopolymerization rate tends to be low and the sensitivity tends to decrease. If the amount is more than 30 parts by weight, the adhesion to the substrate or the like tends to decrease.

  The dielectric loss tangent of the resin obtained by hardening the photosensitive resin composition of the present invention is preferably 0.01 or less, more preferably 0.0094 or less in the driving frequency range of the liquid crystal display device. When the dielectric loss tangent of the resin composition is 0.01 or less, a highly reliable liquid crystal display device in which display burn-in or the like does not occur is obtained when used for forming a liquid crystal split alignment control protrusion on the liquid crystal display device substrate. It is done. In general, a liquid crystal material, an alignment film material, and the like are materials having a large ability to hold electric charges, that is, a material having a relatively small dielectric loss tangent, and the value thereof is generally about 0.005 to 0.02. Therefore, it is considered that the value of the dielectric loss tangent of the alignment control projection material used in the MVA-LCD is preferably the same as or lower than that of the liquid crystal material and alignment film material.

  That is, the lower the dielectric loss tangent of the resin composition used for the alignment control protrusion material, the better. However, at the present time, the lower limit is about 0.003 due to other characteristics required for the alignment control protrusion. Note that the dielectric loss tangent is a value that depends on the measurement frequency, and the waveform of the driving signal of the liquid crystal includes some high-frequency components. Therefore, it is ideally necessary to consider characteristics in a wide frequency range of 10 to 1 kHz. However, since one frame for driving the liquid crystal is actually about 60 Hz, it is appropriate to pay attention to the dielectric loss tangent at a period (second), that is, a frequency around 30 Hz, and a frequency of about 10 to 100 Hz. As a sample for dielectric loss tangent measurement, the cured product film of the photosensitive resin composition according to the present invention was used, and measurement was performed according to the dielectric loss tangent evaluation method described later.

  1 to 3 show various embodiments of a liquid crystal display device to which the present invention is applied.

  FIG. 1 is a cross-sectional view schematically showing an MVA-LCD according to the first embodiment of the present invention in which alignment control protrusions and spacers are formed using the photosensitive resin composition described above. In FIG. 1, a liquid crystal display device 10 has a configuration in which an array substrate 11 provided with active elements for driving liquid crystal and a color filter substrate 12 are arranged facing each other, and liquid crystal molecules 13 are sandwiched therebetween. Have. The array substrate 11 is formed by forming a transparent conductive film 15a on a transparent substrate 14a, and the color filter substrate 12 is formed by forming a transparent base black matrix 16, a colored layer 17, and a transparent conductive film 15b. . The colored layer 17 includes red pixels 17R, green pixels 17G, and blue pixels 17B. The alignment film, the polarizing plate, and the retardation plate are not shown.

  An alignment control protrusion 18 and a spacer 19 are provided on the transparent conductive film 15 b of the color filter substrate 12. These alignment control protrusions 18 and spacers 19 are formed in a lump using the above-described photosensitive resin composition of the present invention.

  FIG. 2 is a cross-sectional view schematically showing an MVA-LCD according to the second embodiment of the present invention. In FIG. 2, the liquid crystal display device 20 has a configuration in which an array substrate 21 provided with active elements for driving liquid crystal and a color filter substrate 22 are arranged to face each other, and liquid crystal molecules 23 are sandwiched therebetween. Have. The array substrate 21 is formed by forming a transparent conductive film 25a on a light transmissive substrate 24a, and the color filter substrate 22 is formed by forming a black matrix 26, a colored layer 27, and a transparent conductive film 25b on the light transmissive substrate 24b. Do it. The colored layer 27 includes red pixels 27R, green pixels 27G, and blue pixels 27B. The alignment film, the polarizing plate, and the retardation plate are not shown.

  On the transparent conductive film 25a of the array substrate 21, an alignment control protrusion 28 and a spacer 29 are provided. These alignment control protrusions 28 and spacers 29 are formed in a lump using the above-described photosensitive resin composition of the present invention.

  FIG. 3 is a cross-sectional view schematically showing an MVA-LCD according to the third embodiment of the present invention. In FIG. 3, the liquid crystal display device 30 has an array substrate 31 on which active elements for driving liquid crystals and color filters are arranged and a black matrix substrate 32 facing each other, and sandwiches liquid crystal molecules 33 between them. It has the structure. That is, the MVA-LCD shown in FIG. 3 is a liquid crystal display device having a COA structure.

  The array substrate 31 is formed by forming a colored layer 37 and a transparent conductive film 35a on a translucent substrate 34a. The colored layer 37 includes red pixels 37R, green pixels 37G, and blue pixels 37B. The black matrix substrate 32 is formed by forming a black matrix 36, a planarizing layer 50, and a transparent conductive film 35b on a translucent substrate 34b. The alignment film, the polarizing plate, and the retardation plate are not shown.

  On the transparent conductive film 35b of the black matrix substrate 32, an alignment control protrusion 38 and a spacer 39 are provided. The alignment control protrusions 38 and the spacers 39 are collectively formed using the above-described photosensitive resin composition of the present invention.

  As described above in detail, according to the present invention, using the photosensitive resin composition having a low dielectric constant, the heights of the alignment control protrusions and the spacers can be secured in one photolithography process. However, it can be formed simultaneously. Therefore, compared with the conventional method, the number of processes and the amount of materials are reduced by about half, and the time and cost can be greatly reduced. Further, since the spacer and the alignment control protrusion having a low dielectric loss tangent value are formed, the liquid crystal display device does not suffer from problems such as image burn-in.

  That is, since a structure having a sufficient difference in height between the alignment control protrusion and the spacer can be produced by applying the resin material once, even when these are formed on the color filter in advance. It is not necessary to overlap the colored pixel layer on the black matrix that is the light shielding layer, and therefore it is possible to form them in a lump without reducing the height accuracy of the spacers.

  Furthermore, since the photosensitive resin composition of the present invention has good electrical characteristics, it is used for a liquid crystal display device having excellent display quality in which an afterimage does not occur even when a voltage is applied for a long time. A substrate can be formed, and a liquid crystal display device with good display characteristics without image sticking can be provided.

  The alignment control protrusions and spacers are not limited to being formed on the color filter substrate side as shown in FIG. 1, but can also be formed on the array substrate side as shown in FIG. Further, as shown in FIG. 3, the present invention can also be applied to a liquid crystal display device having a COA structure in which a color filter is arranged on an array substrate and a black matrix substrate is used as a counter substrate. An alignment control protrusion and a spacer can be formed.

  Examples of the present invention and comparative examples will be specifically described, but the present invention is not limited thereto without departing from the spirit of the present invention. In addition, since the material used in the present invention is extremely sensitive to light, it is necessary to prevent exposure to unnecessary light such as natural light, and it goes without saying that all operations are performed under a yellow or red light.

  The Example regarding the photosensitive resin composition of this invention is demonstrated with a comparative example below.

Example 1
[Preparation of photosensitive resin composition A]
A photosensitive resin composition (A) was prepared in the following manner.

  A five-necked reaction vessel with an internal volume of 1 liter is charged with 20 g of methacrylic acid, 10 g of methyl methacrylate, 55 g of butyl methacrylic acid, 15 g of hydroxyethyl methacrylate, and 400 g of cyclohexanone, and AIBN is added under a nitrogen atmosphere. The mixture was reacted at 0 ° C. for 8 hours to obtain a resin 1 solution (resin concentration 20%).

  Thereafter, a photosensitive resin composition (A) having the following blending ratio was prepared.

Resin 1 solution 500 parts by weight Dipentaerythritol hexaacrylate (DPHA) 250 parts by weight Epoxy resin (Techmore VG3101L) 50 parts by weight Photopolymerization initiator (Irgacure (Irg) -907) 10 parts by weight Propylene glycol monomethyl ether acetate (PGMEA) 580 parts by weight (Example 2)
[Preparation of photosensitive resin composition B]
A photosensitive resin composition (B) having the following blending ratio was prepared.

Resin 1 solution 500 parts by weight Dipentaerythritol hexaacrylate (DPHA) 250 parts by weight Epoxy resin (Techmore VG3101L) 175 parts by weight Photopolymerization initiator (Irgacure (Irg) -907) 10 parts by weight Propylene glycol monomethyl ether acetate (PGMEA) 800 parts by weight (Example 3)
[Preparation of photosensitive resin composition C]
A photosensitive resin composition (C) was prepared in the following manner.

  In a five-necked reaction vessel with an internal volume of 1 liter, 168 g of EPPM501H (manufactured by Nippon Kayaku Co., Ltd.), 72 g of acrylic acid, 0.05 g of methoquinone, 1.1 g of tetraethylammonium bromide, and 285 g of propylene glycol monomethyl ether acetate are charged. It was made to react at 100-110 degreeC for 20 hours. Next, 45 g of phthalic anhydride was charged and reacted at 50 to 60 ° C. for 8 hours to obtain a resin 2 solution (resin concentration 50%).

  Thereafter, a photosensitive resin composition (C) having the following blending ratio was prepared.

Resin 2 solution 200 parts by weight Dipentaerythritol hexaacrylate (DPHA) 250 parts by weight Epoxy resin (Techmore VG3101L) 50 parts by weight Photopolymerization initiator (Irgacure (Irg) -907) 10 parts by weight Propylene glycol monomethyl ether acetate (PGMEA) 580 parts by weight (Example 4)
[Preparation of photosensitive resin composition D]
A photosensitive resin composition (D) having the following blending ratio was prepared.

Resin 2 solution 200 parts by weight Dipentaerythritol hexaacrylate (DPHA) 250 parts by weight Epoxy resin (Techmore VG3101L) 175 parts by weight Photopolymerization initiator (Irgacure (Irg) -907) 10 parts by weight Propylene glycol monomethyl ether acetate (PGMEA) 800 parts by weight (Comparative Example 1)
[Preparation of photosensitive resin composition E]
A photosensitive resin composition (E) having the following blending ratio was prepared.

Resin 1 solution 500 parts by weight Dipentaerythritol hexaacrylate (DPHA) 250 parts by weight Epoxy resin (Techmore VG3101L) 20 parts by weight Photopolymerization initiator (Irgacure (Irg) -907) 10 parts by weight Propylene glycol monomethyl ether acetate (PGMEA) 800 parts by weight (Comparative Example 2)
[Preparation of photosensitive resin composition F]
A photosensitive resin composition (F) having the following blending ratio was prepared.

Resin 1 solution 500 parts by weight Dipentaerythritol hexaacrylate (DPHA) 250 parts by weight Epoxy resin (Techmore VG3101L) 360 parts by weight Photopolymerization initiator (Irgacure (Irg) -907) 10 parts by weight Propylene glycol monomethyl ether acetate (PGMEA) 800 parts by weight (Comparative Example 3)
[Preparation of photosensitive resin composition G]
A photosensitive resin composition (G) having the following blending ratio was prepared.

Resin 1 solution 500 parts by weight Dipentaerythritol hexaacrylate (DPHA) 250 parts by weight Melamine resin 175 parts by weight Photopolymerization initiator (Irgacure (Irg) -907) 10 parts by weight Propylene glycol monomethyl ether acetate (PGMEA) 800 parts by weight ( Comparative Example 4)
[Preparation of photosensitive resin composition H]
A photosensitive resin composition (H) having the following blending ratio was prepared.

Resin 1 solution 500 parts by weight Dipentaerythritol hexaacrylate (DPHA) 250 parts by weight Photopolymerization initiator (Irgacure (Irg) -907) 10 parts by weight Propylene glycol monomethyl ether acetate (PGMEA) 580 parts by weight In Examples 1-4 The composition of the composition is shown in Table 1 below, and the composition of the compositions according to Comparative Examples 1 to 4 is shown in Table 2 below. The numerical value in parentheses is the content (parts by weight). The weight ratio (%) of the aromatic ring was determined by assuming that the molecular weight of the epoxy resin of the composition according to the example was 592 g / mol, of which the aromatic ring equivalent was 288 g / mol.

(Batch formation evaluation)
The substrate for batch formation evaluation was produced using a color filter using a photosensitive coloring composition prepared as follows.

[Photosensitive coloring composition]
<Red coloring composition>
A mixture of the following composition was uniformly stirred and mixed, then dispersed in a sand mill using glass beads having a diameter of 1 mm for 5 hours, and then filtered through a 5 μm filter to prepare a red pigment dispersion.

Red pigment: C.I. I. 18 parts by weight of Pigment Red 254 (“Ilgar For Red B-CF” manufactured by Ciba Specialty Chemicals)
Red pigment: C.I. I. Pigment Red 177 2 parts by weight (Ciba Specialty Chemicals “Chromophthal Red A2B”)
Dispersant (“Ajisper PB821” manufactured by Ajinomoto Fine Techno Co., Ltd.) 2 parts by weight Acrylic varnish (solid content 20%) 50 parts by weight Then, the mixture having the following composition was stirred and mixed to be uniform, and then filtered through a 5 μm filter. Thus, a red coloring composition was obtained.

72 parts by weight of the dispersion Photopolymerizable monomer 18 parts by weight Photoinitiator 3 parts by weight Sensitizer 1 part by weight Cyclohexanone 253 parts by weight <Green coloring composition>
A mixture having the following composition was uniformly stirred and mixed, then dispersed in a sand mill for 5 hours using a glass bead having a diameter of 1 mm, and then filtered through a 5 μm filter to prepare a green pigment dispersion.

Green pigment: C.I. I. Pigment Green 36
("Rionol Green 6YK" manufactured by Toyo Ink Manufacturing Co., Ltd.) 16 parts by weight Yellow pigment: C.I. I. Pigment Yellow 150
("Funchon First Yellow Y-5688" manufactured by Bayer) 8 parts by weight Dispersant ("Disperbyk-163" manufactured by Big Chemie) 2 parts by weight Acrylic varnish (solid content 20%) 102 parts by weight Further, the mixture having the following composition was stirred and mixed so as to be uniform, and then filtered through a 5 μm filter to obtain a green colored composition.

Photopolymerizable monomer 14 parts by weight Photoinitiator 4 parts by weight Sensitizer 2 parts by weight Cyclohexanone 257 parts by weight <Blue coloring composition>
A mixture having the following composition was stirred and mixed uniformly, then dispersed in a sand mill for 5 hours using a glass bead having a diameter of 1 mm, and filtered through a 5 μm filter to prepare a blue pigment dispersion.

Blue pigment: C.I. I. Pigment Blue 15: 6
(“Rionol Blue ES” manufactured by Toyo Ink Co., Ltd.) 3.6 parts by weight Dispersant (“Sols Birds 20000” manufactured by Zeneca) 0.6 parts by weight Acrylic varnish (solid content 20%) 22.1 parts by weight The mixture having the following composition was stirred and mixed so as to be uniform, and then filtered through a 5 μm filter to obtain a blue colored composition.

26.3 parts by weight of the above dispersion 9.4 parts by weight of acrylic transparent resin 4.7 parts by weight of photopolymerizable monomer 1.4 parts by weight of sensitizer 0.2 part by weight of PGMac 11 parts by weight EEP 20 parts by weight 26 parts by weight of cyclohexanone A black matrix substrate which is one of substrates for a liquid crystal display device to which the present invention is applied will be described below.

<Production of black matrix substrate>
The black photosensitive resin composition used for the black matrix formed on the black matrix substrate applied to the present invention includes a binder resin that is an acrylic resin, a photopolymerizable monomer, a photoinitiator, and a black coloring that is carbon black. A known black photosensitive resin composition containing an agent was used.

  After the black photosensitive resin composition is applied on a light-transmitting substrate made of glass by a spin coating method, heating is performed as necessary, for example, heating at 100 ° C. for 3 minutes to dry volatile components such as a solvent (prebaking). Then, a black photosensitive resin layer is formed. Subsequently, after cooling this black photosensitive resin layer, it exposes with the exposure apparatus which makes 365 nm a main wavelength through a photomask. Thereafter, the unexposed portion is developed with an alkali developer such as a 2.5% aqueous sodium carbonate solution, then thoroughly washed with water, further washed with water and dried, and then subjected to heat treatment at 230 ° C. for 60 minutes to allow the black matrix to pass through. It formed on the optical substrate.

  On the black matrix, an acrylic flattening film having a thickness of 1.5 μm was formed to obtain a substrate having a black matrix pattern. Further, after forming a transparent conductive film on the flattening film, spacers and alignment control protrusions are formed using the photosensitive resin composition A or the photosensitive resin composition B, as shown in FIG. A black matrix substrate 31 was obtained.

  A color filter substrate which is one of substrates for a liquid crystal display device to which the present invention is applied will be described below.

<Preparation of color filter substrate>
Using the photosensitive coloring composition, colored pixels were formed by three photolithography processes as follows. In addition, using the translucent board | substrate which formed only the above-mentioned black matrix pattern previously, the red pixel, green pixel, and blue pixel which are color filters were each formed in the opening part of the black matrix.

That is, the red coloring material was applied to a glass substrate by spin coating so that the finished film thickness was 1.8 μm. After drying at 90 ° C. for 5 minutes, light from a high-pressure mercury lamp is irradiated at a dose of 300 mJ / cm ² through a striped photomask for forming a colored layer, developed with an alkali developer for 60 seconds, and striped red A colored layer was obtained. Then, it baked at 230 degreeC for 30 minutes.

  Next, the green coloring material was similarly applied by spin coating so that the finished film thickness was 1.8 μm. After drying at 90 ° C. for 5 minutes, a green colored layer was obtained by exposing through a photomask and developing so that a pattern was formed adjacent to the above-mentioned red colored layer. Then, it baked at 230 degreeC for 30 minutes.

  Further, in the same manner as for red and green, a blue colored layer adjacent to the red and green colored layers having a finished film thickness of 1.8 μm was obtained for the blue colored material. Then, it baked at 230 degreeC for 30 minutes. As a result, a color filter provided with striped colored pixels of three colors of red, green, and blue on the translucent substrate was obtained. The alkaline developer has the following composition.

Sodium carbonate 1.5 parts by weight Sodium hydrogen carbonate 0.5 parts by weight Anionic surfactant (Kao Perirex NBL) 8.0 parts by weight Water 90 parts by weight Next, an indium oxide target is sputtered, A 200 nm thick transparent conductive film was formed on the color filter.

Thereafter, each photosensitive resin composition is applied by a spin coating method to form a photosensitive resin composition layer having a thickness of 4.2 μm on the transparent conductive film, and a spacer formation portion is a light completely transmitting portion having a mask opening of 10 μmφ, Using a wavelength selective mask in which the alignment control protrusion forming part is a semi-transmissive part with a mask opening of 15 μm made of an ITO thin film and the other part is a complete light-shielding part, 150 mJ / cm ² is applied to the photosensitive resin composition layer It was exposed and cured. Here, the transflective portion had a transmittance at 365 nm of 30%, a transmittance at 335 nm of 15%, and a transmittance at 314 nm of 3%.

  Next, after developing with an alkali developer, hardening was performed at 240 ° C. for 60 minutes. Next, the heights of the spacers formed on the black matrix and the alignment control protrusions formed on the transparent conductive film on the colored pixel layer were measured. The measurement results are shown in Table 3 below.

  When the height of the alignment control protrusion is higher than 2/3 of the spacer height, a good alignment effect may not be obtained. Therefore, the height of the alignment control protrusion is 2 / (the height of the spacer). It is desirable that it is 3 or less.

(Elastic recovery rate evaluation)
The elastic properties of the spacers of the substrate used in the batch formation evaluation were evaluated using a microfilm hardness meter HV2000 manufactured by Fischer Instruments. The elastic property was obtained by using a flat indenter of 50 μm × 50 μm, applying a load of 40 mN at a speed of 2.2 mN / second, holding it for 5 seconds, and then removing the load to 0.4 mN at a speed of 2.2 mN / second. The total deformation amount and the plastic deformation amount were measured, and the value of the elastic recovery rate was calculated by the following formula (1).

Elastic recovery rate = (total deformation amount−plastic deformation amount) / total deformation amount (1)
The calculation results are shown in Table 3 below.

  When the elastic restoration rate is less than 50%, the gap is difficult to be uniform in the bonding process between the color filter substrate and the array substrate, and unevenness and display defects are likely to occur in the liquid crystal display device.

(Dielectric loss tangent evaluation)
The photosensitive resin composition was applied by spin coating so that the finished film thickness was 2.0 μm on a glass substrate on which an aluminum film was deposited for electrodes. After drying at 90 ° C. for 5 minutes, light from a high-pressure mercury lamp was irradiated at a dose of 300 mJ / cm ² , developed with an alkali developer for 60 seconds, and then baked at 230 ° C. for 30 minutes.

Aluminium for electrodes having an area of 3.464 × 10 ⁻⁴ m ² was vapor-deposited on the obtained cured coating film to prepare a sample in which the resin coating film was sandwiched between aluminum electrodes. The dielectric loss tangent of the obtained sample in the driving frequency range of the liquid crystal display device was measured using an impedance analyzer ("1260 type" manufactured by Solartron) at an applied voltage of 100 mV. The measurement results are shown in Table 3 below.

<Production of liquid crystal display device>
Using the color filter substrate described above, an MVA-LCD having a structure as shown in FIG. 1 was produced. The obtained MVA-LCD was evaluated for the presence or absence of image burn-in as follows.

  A driving voltage was applied to the liquid crystal of the manufactured MVA-LCD, and the display was held for 100 hours in a white and black checkered flag display state. As a result of visual confirmation, the case where the checkered flag display does not remain is indicated by ◯, and the state where the checkered flag is not indicated is indicated by ×.

The evaluation results are shown in Table 3 below.

  As shown in Table 3 above, in Examples 1 to 4 using the photosensitive resin composition within the scope of the present invention, the alignment control protrusions having sufficient steps with the spacer columns can be collectively formed, and the array It had an elastic recovery rate capable of keeping the gap uniform in the bonding process with the substrate, and the dielectric loss tangent was 0.01 or less in the driving frequency range of the liquid crystal display device, which was a good result.

  On the other hand, in Comparative Example 1 in which the weight ratio of the epoxy resin to the total solid content was 5%, and in Comparative Examples 3 and 4 in which no epoxy resin was used, the dielectric loss tangent exceeded 0.01 and image burn-in occurred. Further, in Comparative Example 2 in which the weight ratio of the epoxy resin to the total solid content is 50%, the alignment control protrusion height exceeds 2/3 of the spacer column, and a good alignment effect is obtained by the alignment control protrusion. It was difficult.

As described above, by simultaneously forming the spacer and the alignment control protrusion using the photosensitive resin composition obtained from Examples 1 to 4, the time and cost of the liquid crystal display substrate manufacturing process can be reduced, and A liquid crystal display device without image sticking can be provided.
The invention described in the original claims is appended below.
[1]
A photosensitive resin composition for forming a plurality of structures having different heights on one opposing surface of a pair of substrates of a liquid crystal display device, an alkali-soluble resin, an epoxy resin having an aromatic ring structure, A photosensitive resin comprising a polyfunctional polymerizable monomer and a photopolymerization initiator, and the amount of the epoxy resin based on the total solid content of the photosensitive resin composition is 10% by weight to 40% by weight Composition.
[2]
Item 1. The epoxy resin is 2- [4- (oxiranylmethoxy) phenyl] -2- [4- [1,1-bis [4- (oxiranylmethoxy) phenyl] ethyl] phenyl] propane. The photosensitive resin composition as described in 2.
[3]
A substrate for a liquid crystal display device in which a black matrix, a planarization layer, a transparent conductive film, and a structure having different heights are formed on a light-transmitting substrate, wherein the structures having different heights are referred to as item 1. Or a substrate for a liquid crystal display device, which is formed using the photosensitive resin composition described in 2 above.
[4]
A substrate for a liquid crystal display device in which a black matrix, a color filter, a transparent conductive film, and a structure having different heights are formed on a light-transmitting substrate, wherein the structures having different heights are referred to as item 1 or A substrate for a liquid crystal display device, which is formed using the photosensitive resin composition described in 2.
[5]
Item 5. The substrate for a liquid crystal display device according to Item 3 or 4, wherein the structures having different heights have a dielectric loss tangent of 0.0094 or less.
[6]
Item 6. A liquid crystal display device comprising the substrate for a liquid crystal display device according to item 3-5.

10, 20, 30, 40 ... Liquid crystal display device,
11, 21, 31, 41 ... array substrate,
12, 22, 42 ... color filter substrate,
13, 23, 33, 43 ... liquid crystal,
14a, 14b, 24a, 24b, 34a, 34b, 44a, 44b ... translucent substrate,
15a, 15b, 25a, 25b, 35a, 35b, 45a, 45b ... transparent conductive film,
16, 26, 36 ... Black matrix,
17, 27, 37 ... colored layer,
17R, 27R, 37R ... red pixels,
17G, 27G, 37G ... green pixels,
17B, 27B, 37B ... blue pixels,
18, 28, 38, 48 ... liquid crystal alignment control protrusions,
19, 29, 39, 49 ... spacers,
32 ... Black matrix substrate,
50: a planarizing layer.

Claims (2)

A black matrix, a planarization layer, a transparent conductive film, and a structure with different heights are formed on a light-transmitting substrate, and the structures with different heights are formed using a photosensitive resin composition. A substrate for a liquid crystal display device,
The photosensitive resin composition contains an alkali-soluble resin, an epoxy resin having an aromatic ring structure, a polyfunctional polymerizable monomer and a photopolymerization initiator, and the epoxy resin relative to the total solid content of the photosensitive resin composition The epoxy resin is 2- [4- (oxiranylmethoxy) phenyl] -2- [4- [1,1-bis [4- (oxy). Ranylmethoxy) phenyl] ethyl] phenyl] propane,
The ingredients having different heights, 0.0094 following which has a dielectric loss tangent, the liquid crystal display device substrate you characterized by its elastic restoration rate is in the range of 58% to 73%. A liquid crystal display device comprising the substrate for a liquid crystal display device according to claim 1 .

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