JP2005221930A - Substrate having projection for orientation control and liquid crystal display using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make it possible to suppress the afterimages generated when a liquid crystal display manufactured by using a substrate formed with projections for orientation control by using a negative type photosensitive resin composition is put in a state of applying a voltage thereto for a long time. <P>SOLUTION: The projections for orientation control of the substrate having at least the projections for orientation control constituting the liquid crystal display holding a liquid crystal between the substrate and a counter substrate is formed of the negative type photosensitive resin composition containing a resin having at least a phenolic hydroxyl group. Further, if the resin has a photodimerization reactive functional group as the side chain of the phenolic hydroxyl group, the sensitivity improves and therefore such is preferable. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vertical alignment (VA) type liquid crystal display (LCD), and more particularly to an alignment control protrusion used in an alignment division vertical alignment (MVA) type multi-domain vertical alignment (LCD) type LCD. And a liquid crystal display device using the same.

  MVA-LCD (Multi-domain Vertical Alignment-Liquid Crystal Display, alignment division vertical alignment type liquid crystal display device, see Patent Documents 1 and 2, Non-Patent Document 1) has a plurality of tilt directions of liquid crystal molecules in one pixel. The vertical alignment type liquid crystal display device which is controlled in this way and is capable of uniform halftone display in all directions, is said to be a liquid crystal display device having excellent contrast, viewing angle characteristics and response speed.

  FIGS. 1A and 1B are explanatory views schematically showing the operation of the MVA-LCD in its cross section. As shown in FIGS. 1A and 1B, a general MVA-LCD (10) includes a TFT side substrate (11) provided with alignment control protrusions (13) via liquid crystal molecules (15). And the color filter side substrate (12) provided with the alignment control protrusions (14). However, the alignment control protrusions (13) and the alignment control protrusions (14) are in alternate positions. It is like that.

  FIG. 1A shows a state when no voltage is applied, and when no voltage is applied, the liquid crystal molecules (15) are vertically aligned between the two substrates, but the alignment control protrusion (13) and the alignment control protrusions. The liquid crystal molecules in part (14) are slightly tilted due to the influence of the slopes of the protrusions. FIG. 1B shows a state when a voltage is applied. When a voltage is applied, the liquid crystal molecules on the slopes of the protrusions begin to tilt, and the liquid crystal molecules other than the tilted portions sequentially have the same orientation. That is, the alignment of liquid crystal molecules is controlled by providing protrusions instead of rubbing treatment.

Conventionally, in order to create such a pattern, a positive resist or a negative resist using an acrylic resin is used to form the pattern by a photolithography technique. However, the former positive resist has a low yield because common defects are likely to occur, while the negative resist using the latter acrylic resin is superior in sensitivity, patterning characteristics, cost, and process, but has an MVA pattern shape. Depending on the type of liquid crystal, there is a problem that burn-in occurs. Burn-in is a phenomenon in which an afterimage is generated when a voltage is applied for a long time in an MVA-LCD, and the display quality is remarkably lowered. One of the causes of this is thought to be the accumulation of electric charges on the surface of the alignment control protrusions, and so the solution is urgently needed.
Japanese Patent No. 2947350 Japanese Patent Laid-Open No. 11-248921 Electronic Journal October 1997 P.I. 33

  The present invention has been made to solve the above-described problems, and is an MVA-LCD substrate provided with an alignment control protrusion using a negative photosensitive resin composition, and a voltage is applied over a long period of time. It is an object of the present invention to provide a substrate having an alignment control protrusion that does not generate an afterimage even in such a state, and a liquid crystal display device using the substrate.

  In order to solve the above problems, the present inventors have studied various materials and processing methods. By using a negative resist containing a group-containing resin, it is possible to obtain a target color filter having alignment control protrusions, and the MVA liquid crystal display device using this color filter has good display characteristics without image sticking. Thus, the present invention has been achieved.

  That is, according to a first aspect of the present invention, in the substrate having at least the alignment control protrusion that constitutes the liquid crystal display device that sandwiches the liquid crystal with the opposing substrate, the alignment control protrusion is at least phenolic. A substrate having an alignment control protrusion, which is formed of a negative photosensitive resin composition containing a resin having a functional hydroxyl group.

  According to a second aspect of the present invention, in the substrate having an alignment control protrusion according to the first aspect, the resin having a phenolic hydroxyl group has a photocrosslinkable group in a part of the side chain. is there.

  According to a third aspect of the present invention, in the substrate having an alignment control protrusion according to the second aspect, the photocrosslinkable group is a photodimerization reactive functional group.

  A fourth invention according to claim 4 is the substrate having the alignment control protrusion according to any one of claims 1 to 3, wherein the resin having a phenolic hydroxyl group has a novolak structure.

  According to a fifth aspect of the present invention, one of the substrates sandwiching the liquid crystal between the opposing substrates is composed of at least a transparent substrate and a color filter layer, and an alignment control protrusion is formed on the color filter layer. The substrate having an alignment control protrusion according to claim 1, wherein the substrate has an alignment control protrusion.

  According to a sixth aspect of the present invention, at least one of the substrates sandwiching the liquid crystal with the opposing substrate comprises at least a transparent substrate and a transparent conductive layer, and an alignment control protrusion is formed on the transparent conductive layer. A substrate having an alignment control protrusion according to claim 1.

  According to a seventh aspect of the present invention, the substrate for sandwiching the liquid crystal with the opposing substrate has a spacer projection, and the spacer projection is the same material as the alignment control projection on the same substrate. The substrate having an alignment control protrusion according to claim 1, wherein the substrate has an alignment control protrusion.

  By using some of these alignment control projections as a substitute for spacers, the color filter manufacturing process is simplified, and a spacer-less MVA liquid crystal display device substrate and a liquid crystal display device using the same are manufactured. It is also possible to do.

  An eighth invention according to an eighth aspect is characterized in that the substrate provided with the alignment control protrusion according to any one of the first to seventh aspects is used for at least one of the opposing substrates sandwiching the liquid crystal. The liquid crystal display device.

  An excellent liquid crystal display device in which an afterimage does not occur even when a voltage is continuously applied for a long time, by forming a liquid crystal display device using the substrate having the alignment control protrusion according to claim 1. Can be provided.

  By using a negative photosensitive resin composition containing a resin having a phenolic hydroxyl group as an alignment control protrusion forming material, development is possible with an alkaline aqueous solution, so that conventional processes can be used and electrical characteristics are excellent. Therefore, it is possible to obtain a substrate and a liquid crystal display device having an alignment control protrusion that exhibits good display characteristics and a wide viewing angle with no afterimage (burn-in).

  Furthermore, a part of the side chain of the resin having a phenolic hydroxyl group has a photocrosslinkable functional group, more preferably a photodimerization reactive functional group, so that it does not receive an inhibition reaction due to oxygen. Sensitivity is advantageous in the process performed.

  By using a resin having both a phenolic hydroxyl group and a photodimerization reactive functional group, no monomer is used or the amount of monomer can be reduced, so that both electrical characteristics and sensitivity are excellent. It becomes a negative resist.

  By forming a spacer replacement protrusion when forming the alignment control protrusion according to the present invention, the manufacturing process of the color filter is simplified and the spacer-less MVA liquid crystal display device substrate and the liquid crystal display device using the same Can also be manufactured.

  Furthermore, in the present invention, independent protrusions are formed on the black matrix of the color filter by the same technique, and the independent protrusions are used as a spacer substitute for maintaining a uniform cell gap when assembling the cells. It is also suitable for obtaining a substrate having a color filter function and a spacer replacement protrusion, which can provide a color liquid crystal display device of the type.

  Hereinafter, embodiments of the present invention will be described in detail.

  The present invention relates to a substrate having at least alignment control protrusions or a liquid crystal display device using the same, which constitutes a liquid crystal display device in which liquid crystal is sandwiched between opposing substrates, and particularly to an alignment division vertical alignment type LCD. It is a liquid crystal display device used for the above.

  Hereinafter, in the present specification, a substrate in which a color filter layer is provided on a light-transmitting substrate and an alignment control protrusion is formed thereon is mainly described. This is a substrate or a liquid crystal display device according to the present invention. However, this does not mean that the color filter layer must be provided.

  As the substrate constituting the substrate having the alignment control projections of the present invention, a plate-like substrate having translucency is preferable, such as glass, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyethersulfone, polyacrylate, or the like. A plastic sheet or film may be mentioned.

  In addition, since the heating process is performed after forming the alignment control projections, a glass substrate excellent in heat resistance is preferable, and furthermore, a glass having a low coefficient of thermal expansion and excellent dimensional stability in the heating process is selected. Is preferred.

  A color filter layer can be formed on a substrate having alignment control projections of the present invention and used as a liquid crystal color filter.

  In the MVA liquid crystal display device, the substrate having the alignment control protrusions having the color filter function may include a transparent protective film layer and a transparent conductive layer on a pixel (color filter layer) in a normal color filter as necessary. And having a specific alignment control protrusion.

  In general, a color filter is formed by forming a black matrix (K) for improving contrast on a transparent substrate, and then a colored pixel layer of red (R), green (G), and blue (B). When this is used for liquid crystal, a transparent conductive layer and an alignment film layer are sequentially laminated. For example, an LCD is placed through a liquid crystal layer by facing a counter substrate on which an electrode such as a thin film transistor is formed. It constitutes.

  In this specification, the black matrix and the red, green, and blue colored pixel layers are collectively referred to as a color filter layer.

  The black matrix constituting the color filter layer can be formed using a known 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 then patterned by a technique such as etching. Alternatively, light-shielding fine particles such as carbon black and metal oxides and colorants such as pigments or dyes are mixed in the photosensitive resin composition, and this is formed as a photosensitive resin layer on the substrate to perform photolithography. Formed by law. Alternatively, there may be mentioned, for example, one formed by laminating two or more colored pixel layers composed of R, G, B, etc., which will be described later, but any method may be used in the present invention.

  The colored pixel layer is provided in the opening of the black matrix, and a pixel pattern composed of three primary colors, usually a red pixel pattern (R), a green pixel pattern (G), and a blue pixel pattern (B), is arranged in a desired shape. It is a thing. As the formation method, there are already 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 ink jetting. In the present invention, any method is used. Also good.

  As an embodiment of the substrate having alignment control protrusions in the present invention, a configuration in which alignment control protrusions are provided on these color filter layers or transparent conductive layers, or color filter layers, transparent conductive layers, alignment control protrusions. The structure is formed in the order of the alignment film layers, or if necessary, consists of a plurality of layers provided with a protective film layer between any of these layers.

  The transparent conductive film layer is an essential component for at least one of the substrates used for the liquid crystal display device, which sandwiches the liquid crystal with the opposing substrate. Normally, it is formed directly under an alignment film or alignment protrusion that regulates the alignment direction of the liquid crystal, and the behavior of the liquid crystal sandwiched between the substrates is controlled by transmitting an electric signal. Alternatively, it can be provided by vapor deposition or the like on the upper layer of the alignment protrusion.

The transparent conductive layer is made of a material that is transparent and conductive and can be formed into a thin film. Usually, an ITO (indium and tin composite oxide) film is used, and IZO (indium and zinc composite oxide) and SnO are used. _{2 A} (tin dioxide) film or the like is selected, and each is formed by a technique such as sputtering or vacuum deposition.

  At least one of the substrates constituting the liquid crystal display device of the present invention is provided with an alignment film layer, which is different from the alignment control protrusion. 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 fired.

  The protective film layer provided as necessary is for flattening the level difference generated when the black matrix and the colored pixel layer are formed, or for the components contained in the black matrix and the colored pixel layer to be mixed into the liquid crystal layer. It is something to prevent and requires transparency. Examples of the material for forming the protective film layer include photocurable, thermosetting, light and thermosetting resin compositions, resin cured products such as epoxy, acrylic and polyimide, and inorganic compounds by sputtering and vapor deposition. Any material can be used as long as the object can be achieved. In consideration of the surface state of the color filter layer, it can be formed in the range of 0.5 to 3 μm.

  A substrate used for an MVA-LCD generally has a specific alignment control protrusion via a transparent protective layer and a transparent conductive layer as necessary on a pixel in a normal color filter. If a normal negative photosensitive resin composition is used in order to obtain an alignment control projection with high dimensional accuracy, the base spread becomes too large to obtain an orientation control projection having a desired shape. In addition, it is difficult to obtain the alignment control protrusions with high dimensional accuracy, particularly when the substrate is enlarged, and the developer resistance of the hardened portion is very important. In addition, since the obtained color filter having alignment control protrusions is applied with an alignment film, the alignment control protrusions themselves are required to have a high degree of heat resistance and solvent resistance, and the alignment film has a polarity through the alignment film thin film. Since it is exposed to liquid crystal, ionic impurities are hardly eluted and excellent electrical characteristics are required.

  As a material for providing alignment control protrusions having such required characteristics, the present inventors are excellent in negative resists containing a phenolic hydroxyl group and a resin having a photocrosslinkable group in a part of the side chain. I found out. It is empirically known that a phenolic hydroxyl group can be developed with an aqueous alkaline solution, so that a conventional process can be used and it exhibits excellent electrical characteristics. In addition, the photodimerization reaction is not sensitive to polymerization by oxygen, and therefore is sensitive to a process performed in air. Furthermore, by using a resin having both a phenolic hydroxyl group and a photodimerization reactive functional group, a monomer is not used or the amount of monomer can be reduced. It becomes a negative photosensitive resin composition excellent both in terms of sensitivity and sensitivity.

  The method of synthesizing the resin having a phenolic hydroxyl group and having a photocrosslinkable group in the side chain, which is included in the negative photosensitive resin composition used in the present invention, is not particularly limited. For example, it has a phenolic hydroxyl group A known method such as introducing a compound having a photocrosslinkable group such as a cinnamoyl group into the hydroxyl group of the resin through an ester bond or the like can be used.

  The resin having a phenolic hydroxyl group includes, for example, an alkali-soluble phenol resin, and the synthesis method is not particularly limited. For example, phenols and aldehydes are condensed in the presence of an acid catalyst. The publicly known method of doing etc. is mentioned. Examples of phenols include phenol, cresol, ethylphenol, butylphenol, xylenol, phenylphenol, catechol, resorcinol, pyrogallol, naphthol, bisphenol C or bisphenol A. These phenols are used alone or in combination of two or more. Examples of the aldehydes include aliphatic or aromatic aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, or benzaldehyde. Among these, a resin including a novolac structure is preferable from the viewpoint of electrical characteristics and ease of handling, and a cresol novolac resin is particularly preferable. In addition, if necessary, the molecular weight distribution of the resin may be adjusted using a means such as fractionation.

  In order to impart photosensitivity to the negative photosensitive resin composition used in the present invention, the resin having a phenolic hydroxyl group preferably has a photocrosslinkable group. More preferably, it has a photodimerization reactive functional group, and the compound having such a functional group is not particularly limited as long as it can be dimerized by light to form a cyclobutane ring. Cinnamic acid compounds such as acid, α-cyanocinnamic acid and p-nitrocinnamic acid, cinnamylidene acetic acid compounds such as cinnamylidene acetic acid and α-cyanocinnamylidene acetic acid, benzalacetophenone, compounds having an α-phenylmaleimide group, or Examples include anthracene, coumarin, furylacrylic acid, compounds having a cyclopropene group, and the like. These acid halides are used for the reaction to introduce a functional group into the resin. In order to increase the sensitivity of the obtained negative photosensitive resin composition, it is particularly preferable to use p-nitrocinnamic acid and benzalacetophenone or their derivatives. These are usually used alone, but can be used in combination of two or more as required.

  The introduction rate of these photocrosslinkable groups is desirably adjusted to 0.5 to 90 mol% with respect to the phenolic hydroxyl group, and more preferably in the range of 0.5 to 70%. If the introduction rate is less than 0.5 mol%, the sensitivity required during production cannot be obtained, whereas if the introduction rate is 90 mol% or more, the storage stability is poor and the alkali solubility of the resin is reduced. However, the developability of the resist is remarkably lowered.

  Furthermore, the sensitivity can be improved by adding an appropriate sensitizer as required. Examples of such a sensitizer include ketones such as p, p-dimethylaminobenzophenone and p, p′-tetramethyldiaminobenzophenone (Michler's ketone), quinones such as 1,2-benzanthraquinone, and 2,6 -A nitro compound such as dichloro-4-nitroaniline and the like can be mentioned, but not limited thereto. These are usually used alone, but can be used in combination of two or more as required.

  In addition to the above components, the negative photosensitive resin composition of the present invention is compatible with additives as necessary, for example, to improve coatability, such as plasticizers, stabilizers, surfactants, and colorants. Leveling agents, coupling agents, fillers, and the like can be added within a range that does not impair the object of the present invention.

  In preparing the photosensitive solution, it may be diluted with an appropriate solvent as necessary, but in that case, drying is required after coating on the substrate. Examples of the solvent include dichloromethane, chloroform, acetone, 2-butanone, cyclohexanone, ethyl acetate, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, 2-ethylethoxyacetate, 2-butoxyethyl acetate, 2-methoxy Ethyl ether, 2-ethoxyethyl ether, 2- (2-ethoxyethoxy) ethanol, 2- (2-butoxyethoxy) ethanol, 2- (2-ethoxyethoxy) ethyl acetate, 2- (2-butoxyethoxy) ethyl acetate , Propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, tetrahydrofuran, 1,4-dioxane and the like.

  Next, a method for forming the alignment control protrusion of the present invention will be described. On the substrate having translucency or, if necessary, the above-described negative photosensitive resin composition on the substrate on which the color filter layer, the transparent conductive layer, and the protective film layer are laminated by the above-described method, Lamination is performed using 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.

  Thereafter, a photomask having a predetermined pattern is brought into close contact, and light exposure is performed to perform pattern exposure, followed by development, and dissolution and removal of unexposed portions to form alignment control projections.

  In the pattern exposure, for example, exposure with an ultra-high pressure mercury lamp, high-pressure mercury lamp, medium-pressure mercury lamp, low-pressure mercury lamp, xenon lamp, halogen lamp, etc. An MVA image faithful to the mask pattern can be obtained. Further, if necessary, the film can be hardened by heat treatment.

  The alignment control protrusions in the present invention are subjected to a heating step after the photolithography process, thereby promoting the curing of the alignment control protrusions and improving the adhesion to the substrate, and further imparting solvent resistance and chemical resistance. In addition, the shape can be made smooth by heat shrinkage and reflow, and the orientation of liquid crystal molecules can be further improved.

  The shape of the alignment control protrusion is preferably regular, such as a dot shape, a stripe shape, or a zigzag shape, and its cross section is a semicircular shape, a semielliptical shape, or a polygonal shape such as a triangle. It is preferable. The pattern on the pixel is not particularly limited as long as the pixel is divided into two or more parts together with the alignment control protrusion on the counter substrate.

  Furthermore, by utilizing a part of these protrusions as a substitute for the spacer, it is possible to simplify the color filter manufacturing process and manufacture a spacer-less MVA liquid crystal display device excellent in cost.

  Hereinafter, embodiments of the present invention will be described with reference to specific examples, but the present invention is not limited to the examples described below. Further, since the negative photosensitive resin composition used in the present invention is extremely sensitive to light, it is necessary to prevent exposure to unnecessary light such as natural light, and all operations are performed under a yellow or red light. Needless to say.

<Synthesis Example of Resin A Having Phenolic Hydroxyl Group: Cinnamation of Novolak Resin>
13.7 g of cresol novolak resin (Asahi Organic Chemicals Co., Ltd., EP 6050G product name) was dissolved in a mixed solution of sodium hydroxide 4 mol / L and methyl ethyl ketone, and cooled to -5 ° C. A methylethylketone / toluene solution of 219 g of chloride was cooled to −5 ° C. and added, and the reaction was stirred at 0 ° C. for 90 minutes. After standing still, the upper layer was dropped into methanol and purified to obtain a target resin A having a phenolic hydroxyl group (hereinafter simply referred to as resin A).

  100 g of the above resin A was dissolved in 400 g of ethylene glycol monomethyl ether acetate (manufactured by Wako Pure Chemical Industries, Ltd.), 1 g of a leveling agent was mixed and dissolved, and then filtered through a 0.2 μm filter to prepare a negative photosensitive resin composition.

  A Cr thin film was formed on a transparent substrate, and a black matrix was formed by a photoetching method. A red photosensitive resin composition is applied thereon, exposed to light, developed, and post-baked to form red pixels, and then the same processing is performed on the green photosensitive resin composition and the blue photosensitive resin composition. A green pixel and a blue pixel were formed.

  Next, an ITO film is formed on the entire surface by sputtering, and further, the negative photosensitive resin composition is applied to a thickness of 1.9 μm with a spin coater. Development processing was performed to form a line pattern having a line width of 10 μm. Subsequently, post-baking was performed at 230 ° C./45 minutes to obtain a substrate for an MVA liquid crystal display device having a color filter layer and alignment control protrusions.

The negative photosensitive resin composition thus obtained was cured at 200 mJ / cm ² and the patterning characteristics were good. Further, when an MVA type liquid crystal display device was produced using a substrate having alignment control projections made of this negative photosensitive resin composition, this MVA type liquid crystal display device had a high viewing angle and voltage for a long time. Even in the state where no is applied, image sticking did not occur and good display performance was exhibited.

<Synthesis example of resin B having phenolic hydroxyl group: nitrocinnamate conversion of novolac resin>
Resin B having the desired phenolic hydroxyl group (hereinafter simply referred to as Resin B) was obtained by operating in the same manner as Resin A except that 264 g of p-nitrocinnamoyl chloride was used instead of 219 g of chlorocinnamic acid. .

  100 g of the above resin B was dissolved in 400 g of ethylene glycol monomethyl ether acetate (manufactured by Wako Pure Chemical Industries, Ltd.), 1 g of a leveling agent was mixed and dissolved, and then filtered through a 0.2 μm filter to prepare a negative photosensitive resin composition. The negative photosensitive resin composition thus adjusted was used in the same manner as in Example 1 to obtain an MVA liquid crystal display substrate having a color filter layer and alignment control protrusions.

The negative photosensitive resin composition thus obtained was sufficiently cured at 150 mJ / cm ² and had good patterning characteristics. Further, when an MVA type liquid crystal display device was produced using a substrate having alignment control projections made of this negative photosensitive resin composition, this MVA type liquid crystal display device had a high viewing angle and burn-in occurred. The display performance was good.

  100 g of the above resin B is dissolved in 400 g of ethylene glycol monomethyl ether acetate (manufactured by Wako Pure Chemical Industries, Ltd.), 10 g of p, p′-tetramethyldiaminobenzophenone is added as a sensitizer, 1 g of leveling agent is mixed and dissolved, and then a 0.2 μm filter. A negative photosensitive resin composition was prepared by filtration. The negative photosensitive resin composition thus adjusted was used in the same manner as in Example 1 to obtain an MVA liquid crystal display substrate having a color filter layer and alignment control protrusions.

The negative photosensitive resin composition thus obtained was cured at 70 mJ / cm ² and had good patterning characteristics. Further, when an MVA type liquid crystal display device was produced using a substrate having alignment control projections made of this negative photosensitive resin composition, this MVA type liquid crystal display device had a high viewing angle and burn-in occurred. The display performance was good.

<Synthesis Example of Resin C Having Phenolic Hydroxyl Group: Cinnamylidene Acetate Conversion of Novolak Resin>
After dissolving 6.4 g of cresol novolak resin (Asahi Organic Materials Co., Ltd., EP6050G product name) in a mixed solution of 4 mol / L sodium hydroxide and methyl ethyl ketone, the solution was cooled to −10 ° C., and from 17 g of cinnamylideneacetic acid. A methyl ethyl ketone solution of the obtained cinnamylidene acetyl chloride was added and stirred at -3 ° C. for 90 minutes for reaction. After standing, the upper layer was dropped into methanol for purification to obtain a resin C having a target phenolic hydroxyl group (hereinafter simply referred to as resin C).

  100 g of the above resin C was dissolved in 400 g of ethylene glycol monomethyl ether acetate (manufactured by Wako Pure Chemical Industries, Ltd.), and 1 g of a leveling agent was mixed and dissolved, followed by filtration with a 0.2 μm filter to prepare a negative photosensitive resin composition. The negative photosensitive resin composition thus adjusted was used in the same manner as in Example 1 to obtain an MVA liquid crystal display substrate having a color filter layer and alignment control protrusions.

The negative photosensitive resin composition thus obtained was cured at 120 mJ / cm ² and had good patterning characteristics. Further, when an MVA type liquid crystal display device was produced using a substrate having alignment control projections made of this negative photosensitive resin composition, this MVA type liquid crystal display device had a high viewing angle and burn-in occurred. The display performance was good.

<Synthesis example of resin D having phenolic hydroxyl group: benzalacetophenonization of novolak resin>
In 60 g of acetic anhydride, 33 g of cresol novolak resin (manufactured by Asahi Organic Materials Co., Ltd., EP 6050G product name) is dissolved while cooling, and after acetylation reaction is carried out using 10 g of sulfuric acid as a catalyst, purification is performed twice by putting it in water. A resinous acetoxyphenol novolak resin was precipitated. Next, this acetoxylated resin was dissolved in nitrobenzene, 35 g of anhydrous aluminum chloride was slowly added, and the mixture was kept at 25 to 30 ° C. for acetyl transfer reaction and then purified to obtain a hydroxyacetophenone resin. 24 g of this resin and 11 g of p-methylbenzaldehyde were dissolved in glacial acetic acid, reacted by adding sulfuric acid, and purified to obtain a resin D having a phenolic hydroxyl group (hereinafter simply referred to as “resin D”).

  100 g of the above resin D was dissolved in 400 g of ethylene glycol monomethyl ether acetate (manufactured by Wako Pure Chemical Industries, Ltd.), 1 g of the leveling agent was mixed and dissolved, and then filtered through a 0.2 μm filter to prepare a negative photosensitive resin composition. The negative photosensitive resin composition thus adjusted was used in the same manner as in Example 1 to obtain an MVA liquid crystal display substrate having a color filter layer and alignment control protrusions.

The negative photosensitive resin composition thus obtained was cured at 100 mJ / cm ² and had good patterning characteristics. Further, when an MVA type liquid crystal display device was produced using a substrate having alignment control projections made of this negative photosensitive resin composition, this MVA type liquid crystal display device had a high viewing angle and burn-in occurred. The display performance was good.

  100 g of cresol novolac resin (Asahi Organic Materials Co., Ltd., EP6050G product name) is dissolved in 400 g of ethylene glycol monomethyl ether acetate (Wako Pure Chemical Industries, Ltd.), 40 g of benzalacetophenone, Manufactured by Aronics M-400 (product name), 3 g of Irgacure 369 (manufactured by Ciba Specialty Chemicals) and 1 g of leveling agent were mixed and dissolved, followed by filtration with a 0.2 μm filter to obtain a negative photosensitive resin composition. Prepared. The negative photosensitive resin composition thus adjusted was used in the same manner as in Example 1 to obtain an MVA liquid crystal display substrate having a color filter layer and alignment control protrusions.

The negative photosensitive resin composition thus obtained was cured at 200 mJ / cm ² and had good patterning characteristics. Further, when an MVA type liquid crystal display device was produced using a substrate having alignment control projections made of this negative photosensitive resin composition, this MVA type liquid crystal display device had a high viewing angle and burn-in occurred. The display performance was good.
[Comparative Example 1]
100 g of polyvinyl alcohol cinnamate (polyvinylcinnamate) is dissolved in 400 g of ethylene glycol monomethyl ether acetate (manufactured by Wako Pure Chemical Industries, Ltd.), 1 g of leveling agent is mixed and dissolved, and then filtered through a 0.2 μm filter. Type photosensitive resin composition was prepared. Here, polyvinyl cinnamate is synthesized by a known method (Tokyo Industrial Test). The negative photosensitive resin composition thus adjusted was used in the same manner as in Example 1 to obtain an MVA liquid crystal display substrate having a color filter layer and alignment control protrusions.

  The negative photosensitive resin composition thus obtained had good patterning characteristics. However, when an MVA liquid crystal display device was produced using a substrate having alignment control projections made of this negative photosensitive resin composition, the MVA liquid crystal display device was burned when a voltage was applied for a long time. It was.

It is explanatory drawing which shows the board | substrate for liquid crystal display devices in which the alignment protrusion was formed by the method which concerns on this invention.

Explanation of symbols

10 ... MVA-LCD
DESCRIPTION OF SYMBOLS 11 ... TFT side substrate 12 ... Color filter side substrate 13 ... Orientation control protrusion 14 ... Orientation control protrusion 15 ... Liquid crystal molecule

Claims (8)

  A negative photosensitive resin comprising a liquid crystal display device that sandwiches liquid crystal with an opposing substrate and having at least alignment control protrusions, wherein the alignment control protrusions include a resin having at least a phenolic hydroxyl group. A substrate having alignment control protrusions, characterized by being formed of a composition.   2. The substrate having an alignment control protrusion according to claim 1, wherein the resin having a phenolic hydroxyl group has a photocrosslinkable group in a part of a side chain.   The substrate having an alignment control protrusion according to claim 2, wherein the photocrosslinkable group is a photodimerization reactive functional group.   4. The substrate having alignment control protrusions according to claim 1, wherein the resin having a phenolic hydroxyl group has a novolac structure.   5. One of the substrates sandwiching the liquid crystal between the opposing substrates comprises at least a transparent substrate and a color filter layer, and an alignment control protrusion is formed on the color filter layer. A substrate having the alignment control protrusion according to any one of the above.   6. The substrate according to claim 1, wherein at least one of the substrates sandwiching the liquid crystal with the opposing substrate comprises at least a transparent substrate and a transparent conductive layer, and an alignment control protrusion is formed on the transparent conductive layer. A substrate having the alignment control protrusion according to any one of the above.   The substrate for sandwiching the liquid crystal with the opposing substrate has a spacer projection, and the spacer projection is formed of the same material as the alignment control projection on the same substrate. Item 7. A substrate having an alignment control protrusion according to any one of Items 1 to 6.   8. A liquid crystal display device, wherein the substrate provided with the alignment control protrusion according to claim 1 is used as at least one of opposing substrates sandwiching liquid crystal.

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