JP2006201234A - Substrate with spacer and alignment control protrusion, and liquid crystal display device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress image persistence produced on a liquid crystal display device, manufactured by forming alignment control protrusions by using a high-sensitivity negative photosensitive resin composition, and further using a substrate which has the alignment control protrusions, in a state with voltage being applied to the device for a long time. <P>SOLUTION: In the substrate, constituting the liquid crystal display device with a liquid crystal interposed between itself and the facing substrate, and having at least the alignment control protrusions, the alignment control protrusions are formed with a negative photosensitive resin composition comprising a resin, having at least a phenolic hydroxy group, a melamine derivative, and a photo-induced acid generator, having an absorption band at 365 nm and/or 405 nm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vertically aligned (VA) type liquid crystal display (LCD), and more particularly, to a spacer and alignment control used in an alignment-divided vertical alignment (MVA, multi domain vertically aligned) type LCD. The present invention relates to a substrate having protrusions and a liquid crystal display device using the same.

  An 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. 2C and 2D are explanatory diagrams schematically showing a cross section of the MVA-LCD. As shown in FIG. 2, the general MVA-LCD (40) is provided with a spacer (26) in addition to the alignment control protrusion (25). The spacer (26) has a role of keeping the distance between the color filter side substrate (20) and the TFT side substrate (30) constant.

  In order to form such a pattern having alignment control protrusions and spacers, it is necessary to add a new process for forming the alignment control protrusions to the process in which only spacer formation has been conventionally performed. When these patterns are formed by photolithography, it is common to use a positive photosensitive resin composition for forming alignment control protrusions and a negative photosensitive resin composition for forming spacers. It is. Although this method is superior in sensitivity and patterning characteristics, it must be prepared in separate steps because of different materials. In addition, processes such as replacement of resist solution and developer increase, reducing time and cost. Has become an issue.

In order to solve this problem, a method for forming the alignment control protrusions and spacers together has been studied. As this method, for example, a method of differentiating the exposure amount by performing multiple exposures (see Patent Document 3), A method in which at least two layers of the colored pixel layer and the light-shielding layer are overlapped in advance to make the spacer forming portion high (see Patent Document 4), and two photosensitive resin composition layers having different photosensitivity are stacked to select a wavelength. A method of exposing with a photomask (see Patent Document 5) has been reported. However, it is difficult to control the accuracy of the shape because these are only the difference in the exposure amount, it is difficult to maintain the height accuracy of the spacer to overlap the colored pixel layer, and the process for forming the photosensitive resin composition layer increases. There was a problem.
Japanese Patent No. 2947350 Japanese Patent Laid-Open No. 11-248921 Electronic Journal October 1997 P.I. 33 JP 2002-236371 A Japanese Patent No. 3255107 JP 2003-248323 A

Also in the photosensitive resin composition itself, the former positive photosensitive resin composition tends to cause common defects, resulting in poor yield, while the latter negative photosensitive resin composition has sensitivity, patterning characteristics, cost, and Although excellent in process, there is a problem that image sticking occurs depending on the shape of the protrusion pattern for alignment control and the type of liquid crystal. 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.
Generally, the volume resistivity of the alignment control protrusions formed using the conventional negative photosensitive resin composition is about 1.0 × 10 ^{14 to} 1.0 × 10 ¹⁵ Ωcm, and such volume resistance The MVA-LCD provided with the alignment control protrusions having a high rate is likely to be burned, and so the solution is an important issue.

  In many cases, the negative photosensitive resin composition basically contains a compound having an ethylenically unsaturated bond as a monomer as a curing component in addition to the binder resin, but this monomer has an adverse effect on electrical characteristics. Since this is empirically known, the photosensitive resin composition for protrusions for orientation control is also required to reduce the monomer.

  The present invention has been made to solve the above problems, and by using a negative photosensitive resin composition, the process of forming spacers and alignment control protrusions is simplified to significantly reduce time and cost. It is another object of the present invention to provide a substrate having an excellent display quality that does not generate an afterimage even when a voltage is applied for a long time, a substrate having an alignment control protrusion, and a liquid crystal display device using the substrate.

  As a result of studying various materials and processing methods in order to solve the above-mentioned problems, the present inventor has achieved the object by using the following negative photosensitive resin composition as a spacer and an alignment control protrusion forming material. A substrate on which spacers and configuration control protrusions are formed at the same time can be obtained, and the MVA-LCD using the substrate has been found to exhibit good display characteristics without burn-in and a high viewing angle. It is.

In other words, according to a first aspect of the present invention, in a substrate having at least a spacer and an alignment control protrusion that constitutes a liquid crystal display device that sandwiches liquid crystal with an opposing substrate, the spacer and the alignment control protrusion are provided on the substrate. At least (a) a binder resin,
(B) a crosslinking agent that reacts by the action of an acid,
(C) a compound having an ethylenically unsaturated bond,
(D) a photoacid generator,
(E) formed of a negative photosensitive resin composition containing a photoradical generator,
(E) A substrate having spacers and alignment control protrusions, wherein the photoradical generator has at least a wavelength region in which (d) the photoacid generator does not generate an acid in an exposure wavelength region where radicals are generated. .

A second invention according to claim 2 is a compound in which the (d) photoacid generator generates an acid by light having a wavelength of less than 365 nm and does not generate an acid by light having a wavelength of 365 nm,
2. The substrate having spacers and alignment control protrusions according to claim 1, wherein (e) the photo radical generator is a compound that generates radicals by light having a wavelength of 365 nm or more.

（式中、Ｒは置換されていてもよいアルキル基、置換されていてもよいアリール基、置換されていてもよいアラルキル基、置換されていてもよいアルケニル基、置換されていてもよい複素環基、または置換されていてもよい脂環基を表す。） A third invention according to claim 3 is characterized in that the (d) photoacid generator is a compound represented by the general formula (1), and the spacer according to claim 1 or 2 A substrate having alignment control protrusions.

(In the formula, R is an optionally substituted alkyl group, an optionally substituted aryl group, an optionally substituted aralkyl group, an optionally substituted alkenyl group, and an optionally substituted heterocyclic ring. Represents a group or an alicyclic group which may be substituted.)

The fourth invention according to claim 4 is characterized in that (a) the binder resin includes a resin having a phenolic hydroxyl group, the spacer and the alignment control protrusion according to any one of claims 1 to 3, It is a substrate which has.

According to a fifth aspect of the present invention, the substrate provided with the spacer according to any one of the first to fourth aspects and the alignment control protrusion is used for at least one of the opposing substrates that sandwich the liquid crystal. This is a liquid crystal display device.

  In the substrate of the present invention, the negative photosensitive resin composition contains (d) a photoacid generator and (e) a photoradical generator. (D) The photoacid generator generates an acid upon exposure at a specific wavelength (λ1), and (b) reacts with a crosslinking agent that reacts by the action of the acid to cure the negative photosensitive resin composition. Let Since this reaction is not inhibited by oxygen, sufficient curability can be obtained on the film surface exposed to air. This reaction is therefore preferred for forming spacers that require height.

  Further, (e) the photoradical generator generates radicals by exposure at a specific wavelength (λ2; λ1 ≠ λ2), and contributes to the polymerization reaction of the compound (c) having an ethylenically unsaturated bond. The type photosensitive resin composition is cured. Since this reaction is affected by polymerization inhibition by oxygen, the progress of curing of the film surface is delayed. For this reason, it is preferable to form a smooth-shaped orientation control protrusion. In this reaction, (e) the wavelength used for curing can be selected depending on the type of photoradical generator and the sensitizer.

  In the present invention, by optimally combining a photoacid generator and a photoradical generator and selecting a reaction system used for curing by controlling the exposure wavelength, alignment control protrusions and spacers having different height and shape patterns, It has become possible to simultaneously form the same material.

  For example, when (d) a compound that absorbs less than 365 nm as a photoacid generator and does not generate acid with 365 nm light, and (e) a compound that absorbs at 365 nm as a photoradical generator is used in combination with a full wavelength exposure In the part, the reaction of both compounds contributes to the formation of a spacer with a thick upper surface and an upper bottom with the cured upper surface and the inside. On the other hand, only the latter photoradical polymerization reaction contributes to the portion exposed to light obtained by cutting light having a short wavelength of 314 nm, so that alignment control protrusions having a thin film thickness and no bottom can be formed.

  In the substrate of the present invention, the resin is sufficiently cured by using a crosslinking agent that reacts with the negative photosensitive resin composition by the action of acid (b). Therefore, it is possible to reduce the compound (c) having an ethylenically unsaturated bond, which has been conventionally used for curing a resin, and to provide a substrate and a liquid crystal display device having alignment control protrusions that are more stable and have no burn-in. I was able to.

In addition, (a) by using a negative photosensitive resin composition containing a resin having a phenolic hydroxyl group as a binder resin, it can be developed with an alkaline aqueous solution, so that a conventional process can be used and the electrical characteristics are excellent. Since the charge hardly accumulates on the surface of the alignment control protrusion, the substrate and the liquid crystal display device having the alignment control protrusion exhibiting good display characteristics without image sticking (afterimage) and a wide viewing angle can be obtained.

Hereinafter, embodiments of the present invention will be described in detail.
The present invention relates to a substrate having at least a spacer and an alignment control protrusion, or a liquid crystal display device using the same, which constitutes a liquid crystal display device that sandwiches liquid crystal with an opposing substrate. It is a liquid crystal display device used for a type LCD.

  Hereinafter, in the present specification, a substrate in which a color filter layer is provided on a light-transmitting substrate and a spacer and an alignment control protrusion are formed thereon is mainly described. It does not mean that the display device must have a color filter layer.

As the substrate constituting the substrate having the spacer and the alignment control projection of the present invention, a plate-like substrate having translucency is preferable, and glass, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyethersulfone and polyacrylate are preferable. Such as plastic sheet or film.
In addition, a glass substrate with excellent heat resistance is preferred because a heating process is performed after forming spacers and alignment control projections. Further, a glass with a low coefficient of thermal expansion and excellent dimensional stability in the heating process is selected. It is preferable to do.

A color filter layer can be formed on the substrate having the spacer of the present invention and the alignment control protrusion, and used as a color filter for liquid crystal.
As the structure of the substrate having the spacer having the color filter function and the alignment control protrusion in the MVA liquid crystal display device, the transparent protective film layer and the transparent conductive film are formed on the pixel (color filter layer) in the normal color filter as necessary. It has a specific spacer and alignment control protrusion through a layer.

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 a liquid crystal, a transparent conductive film layer and an alignment film layer are further laminated in order, for example, opposed to a counter substrate on which an electrode such as a thin film transistor is formed, via a liquid crystal layer It constitutes an LCD.
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 red, green, blue, 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 a form of the substrate having spacers and alignment control protrusions in the present invention, a configuration in which spacers and alignment control protrusions are provided on these color filter layers or transparent conductive film layers, or color filter layers and transparent conductive films. It is characterized in that it comprises a plurality of layers in which a protective film layer, a spacer, an alignment control protrusion, an alignment film layer are formed in this order, or a protective film layer provided between any of these layers if necessary.

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 film layer is made of a material that is transparent, conductive, and can be formed into a thin film. Usually, an ITO (indium and tin composite oxide) film is used, and the other is IZO (indium and zinc composite oxide). And SnO ₂ (tin dioxide) film are selected and formed by a method 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 transparent protective layer and a specific spacer and an alignment control protrusion via a transparent conductive layer as necessary on a pixel in a normal color filter.

As the binder resin of the present invention, a resin having a phenolic hydroxyl group is preferably used from the viewpoint of preventing seizure. Since phenolic hydroxyl groups can be developed with an aqueous alkaline solution, conventional processes can be used in the development step. Examples of the resin having a phenolic hydroxyl group include polyvinylphenol and novolac resin. Polyvinylphenol can be represented by the structural unit represented by the following general formula (2), and includes a single or two or more polymers of hydroxystyrenes such as p-hydroxystyrene and 2- (p-hydroxyphenyl) propylene. It is done. The polyvinylphenol resin is usually obtained by polymerizing hydroxystyrenes which may have a substituent alone or in the presence of a radical polymerization initiator or a cationic polymerization initiator.

  Note that the structural unit represented by the general formula (2) has a particularly preferable structure, and the compound represented by the general formula (2) is not limited to these. For example, p-vinylphenol What is necessary is just to include the unit shown by the said General formula (2), such as a copolymer of styrene.

（式中、ｍは０以上（二量体以上の混合物）であることを表し、Ｒは水素、メチル基を表す） The novolak resin can be represented by the structural unit represented by the following general formula (3), and is not particularly limited. For example, phenol, o-cresol, m-cresol, p-cresol, bisphenol A, and the like. It can be easily obtained by condensing a phenol compound of aldehyde with an aldehyde compound such as formaldehyde, acetaldehyde or salicylaldehyde. Among these, cresol novolak or phenol novolak resin represented by the general formula (3) is particularly preferable.

(In the formula, m represents 0 or more (a mixture of dimers or more), and R represents hydrogen or a methyl group)

  The structural unit represented by the general formula (3) has a particularly preferable structure, and the compound represented by the general formula (3) is not limited to these. Moreover, you may contain 2 or more types of compounds to be used.

  The crosslinking agent that reacts by the action of an acid in the present invention causes a dehydration or demethanol condensation reaction between polyvinylphenol and the crosslinking agent that reacts by the action of the acid by the action of an acid generated from the photoacid generator. The resin can be cross-linked and insolubilized in the developer. Such a crosslinking agent that reacts by the action of an acid may be a compound having an alkoxymethyl group or an acetyloxymethyl group, and preferably has a high solubility, particularly a solubility in a solvent. Such compounds include, for example, di-, tri-, tetra-, penta-, hexa-methylol melamine, melamine compounds such as di-, tri-, tetra-, penta-, hexa-methoxymethyl melamine, or these Melamine resin, di-, tetra-, urea derivatives such as methoxyurea resin, di-, tri-, tetra-acetyloxymethylbenzene, di-, tri-, tetra- Although methylolbenzene etc. can be mentioned, it is not this limitation.

  The amount of the crosslinking agent that reacts by the action of the acid contained in the negative photosensitive resin composition of the present invention can range from 1 to 60 parts by weight with respect to 100 parts by weight of the binder resin. Preferably it is 5-50 weight part.

（式中、Ｒは置換されていてもよいアルキル基、置換されていてもよいアリール基、置換されていてもよいアラルキル基、置換されていてもよいアルケニル基、置換されていてもよい複素環基、または置換されていてもよい脂環基を表す。）またこれらは単独で、または２種以上を組み合わせて使用してもよい。 The photoacid generator of the negative photosensitive resin composition in the present invention proceeds with a crosslinking reaction of a resin having a phenolic hydroxyl group and a crosslinking agent that reacts with an acid by the action of an acid generated upon exposure. Will be allowed to. In particular, since it is used for curing the spacer in the present invention, it preferably has an absorption characteristic that works at the time of exposure with light of all wavelengths from a light source and does not work at the time of exposure with light having a short wavelength cut, specifically 365 nm. And those that absorb less than and that do not generate acid under 365 nm light. Furthermore, when a photoacid generator having strong absorption at 365 nm and / or 405 nm is used, it is preferable because the sensitivity can be very high with respect to exposure. The photoacid generator is not particularly limited as long as it satisfies the above-described characteristics and has high solubility, particularly solubility in a solvent. However, from the viewpoint of sensitivity and thermal stability, the following general formula (1) Particularly preferred are compounds having a structure. In addition, the compounds listed below are more ionic because they are not ionic.

(In the formula, R is an optionally substituted alkyl group, an optionally substituted aryl group, an optionally substituted aralkyl group, an optionally substituted alkenyl group, and an optionally substituted heterocyclic ring. Represents an alicyclic group which may be substituted or substituted.) These may be used alone or in combination of two or more.

  The amount of the photoacid generator contained in the negative photosensitive resin composition of the present invention can range from 1 to 20 parts by weight with respect to 100 parts by weight of the crosslinking agent that reacts by the action of an acid. Yes, preferably 3 to 15 parts by weight.

  The compound having an ethylenically unsaturated bond in the present invention is not particularly limited as long as it undergoes a polymerization reaction by the action of radicals. For example, a monomer having a vinyl group or an allyl group, an oligomer, a vinyl group or allyl at the terminal or side chain. Examples thereof include a polymer having a group. Such compounds include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, polyethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol. Various acrylic esters and methacrylic esters such as hexa (meth) acrylate, tricyclodecanyl (meth) acrylate, melamine (meth) acrylate, epoxy (meth) acrylate, (meth) acrylic acid, styrene, vinyl acetate, (meta ) Acrylamide, N-hydroxymethyl (meth) acrylamide, acrylonitrile, urethane acrylate, polyfunctional (meth) acrylate having urethane group polyester, etc. Kill, but not limited thereto. Moreover, you may use these in mixture of 2 or more types as needed.

  The amount of these ethylenically unsaturated compounds can be in the range of 10 to 120 parts by weight, preferably 20 to 80 parts by weight, with respect to 100 parts by weight of the binder resin. If the amount is 10 parts by weight or less, the sensitivity decreases, and if it is 120 parts by weight or more, the electric characteristics of the formed alignment control protrusions are deteriorated, so that seizure is likely to occur, and the tackiness of the coating film is too high. It may cause mask contamination at times.

  Further, the photo radical generator used in the present invention is not particularly limited as long as it can generate radicals with 365 nm light, and a compound having high internal curability suitable for the formation of alignment control protrusions of the present invention is particularly preferable. The photo radical generator can be mixed with a sensitizer as necessary.

Examples of such a photo radical generator include benzoin alkyl ethers such as beizoin isopropyl ether, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropane-1 Α-hydroxy ketones such as 2-one, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) ) Α-amino ketones such as butanone-1, bisacylphosphine oxides such as bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, 2- (o-chlorophenyl) -4 , 5-diphenylimidazolyl dimer, 2- (o-chlorophenyl) -4,5-di- (m-methoxyphenyl) imidazolyl dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazolyl dimer, 2- (p-methoxy) Bisimidazoles such as phenyl) -4,5-diphenylimidazolyl dimer, N-aryl glycines such as N-phenylglycine, organic azides such as 4,4′-diazidochalcone, 3,3 ′, 4 , 4′-tetra (tert-butylperoxycarboxyl) benzophenone and other organic peroxides, sulfonium salts, diazonium salts, phosphonium salts, selenonium salts, arsonium salts, iodonium salts and the like.
Examples of the sensitizer mixed with the photoradical generator include benzophenones such as Michler's ketone, thioxanthones, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, and 2-mercaptobenzimidazole.

  The amount of these photo radical generators is preferably 1 to 50 parts by weight, more preferably 5 to 20 parts by weight with respect to 100 parts by weight of the ethylenically unsaturated compound.

  In addition to the above components, the negative photosensitive resin composition of the present invention is compatible with additives as necessary, for example, for improving sensitivity, coatability, adhesion, heat resistance, chemical resistance, for example, A plasticizer, a stabilizer, a surfactant, a colorant, a leveling agent, a coupling agent, a filler, and the like can be added as long as the object of the present invention is not impaired.

  A conductive film is provided on the uppermost layer using a known coating means such as a roll coater, spin coater, roll coater, die coater, etc., with the photosensitive solution obtained by selecting each component in a timely manner and mixing it at an arbitrary ratio. Apply on the color filter substrate.

  In preparing the photosensitive solution, it may be diluted with a suitable solvent as necessary. In that case, drying is required after coating on the substrate. Examples of the solvent include dichloroethane, 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 spacer and the alignment control protrusion of the present invention will be described. The negative photosensitive resin composition described above on a substrate having a light-transmitting property or a substrate on which a color filter layer, a transparent conductive film layer, and a protective film layer are laminated by the above-described method if necessary. Are laminated 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.

  Then, through a photomask having a predetermined pattern, pattern exposure is performed with, for example, an ultra-high pressure mercury lamp, a high-pressure mercury lamp, a medium-pressure mercury lamp, a low-pressure mercury lamp, a xenon lamp, a halogen lamp, etc. After cross-linking, development with an alkali developer can provide a spacer faithful to the mask pattern and an alignment control projection pattern. Here, the pattern exposure through the photomask having the predetermined pattern is that the spacer pattern forming portion is exposed at all wavelengths, and the alignment control protrusion pattern forming portion is light with a short wavelength of 314 nm or less cut. An exposure process for exposure. As such a method, for example, a method of exposing a plurality of times using a plurality of different photomasks having a predetermined pattern, a filter for cutting short wavelength light (low transmittance of short wavelength light), etc. A method of combining them, a method of exposing only once with a single photomask having a plurality of patterns having different light transmission characteristics, and the like can be mentioned, but it is not limited to these.

  The photosensitive resin composition according to the present invention is formed by the above-described pattern exposure, the spacer has a high height and a flat cross-sectional shape on the upper surface, while the alignment control protrusion has a low height and a semicircular or forward-tapered cross-section with a non-flat upper surface. Patterns having different cross-sectional shapes called shapes can be formed by a single photolithography process.

  Furthermore, by performing a heat treatment after the photolithography step, the curing of the pattern can be promoted to improve the adhesion to the substrate, and further solvent resistance and chemical resistance can be imparted. In addition, the alignment control protrusions are less curable than spacer portions cured by full-wavelength exposure, so that the shape becomes smooth due to heat shrinkage and heat flow, and the alignment of liquid crystal molecules is further improved. Is possible. The heating step is preferably performed at a temperature and time at which the thermosetting component sufficiently reacts in a hot plate, hot air furnace, far-infrared furnace, or the like, and is optimally performed at 200 to 250 ° C. for 15 to 100 minutes.

  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.

  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 was formed on the entire surface by sputtering to form a transparent conductive film layer, which was used as a color filter substrate.

  After dissolving 20 g of cresol novolac resin (Asahi Organic Materials Co., Ltd., product name; EP6050G) in 140 g of cyclohexanone (Kanto Chemical Co., Ltd.), 3 g of melamine resin (manufactured by Sanwa Chemical Co., Ltd., product name: Nicalac MW-30HM), DPHA (manufactured by Toa Gosei Co., Ltd., product name; Aronix M-400), 16 g, photoacid generator (manufactured by Ciba Specialty Chemicals Co., Ltd., product name: CGI-263), 0.5 g, bis (2,4,6-trimethylbenzoyl) -Phenylphosphine oxide (Ciba Specialty Chemicals, product name; Irgacure 819) A negative photosensitive resin composition in which 2.4 g was mixed and dissolved was applied to a color filter substrate with a thickness of 4.0 μm using a spin coater. One photomass having a plurality of patterns having different light transmission characteristics after pre-baking Exposed through a (FIG. 2), after exposure at 90 ° C. heating to form a predetermined pattern Alkali development. Subsequently, post-baking was performed at 230 ° C./30 minutes to obtain a color filter substrate having spacers and alignment control protrusions.

  When the pattern on the substrate thus obtained was observed, the spacer had a flat cross-sectional shape with a height of 3.5 μm, and the alignment control protrusion had a semicircular cross-sectional shape with a height of 1.5 μm. It was. When an MVA-LCD was manufactured using this spacer and a color filter substrate having alignment control protrusions, this MVA-LCD has a high viewing angle and burn-in occurs even when a voltage is applied for a long time. The display performance was good.

  Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (manufactured by Ciba Specialty Chemicals, product name; Irgacure 819) Instead of 2.4 g, 2-methyl-1 [4- (methylthio) phenyl]- 1.6 g of 2-morpholinopropan-1-one (manufactured by Ciba Specialty Chemicals, product name; Irgacure 907) and 0.4 g of 2,4-diethylthioxanthone (manufactured by Nippon Kayaku Kogyo Co., Ltd., product name: DETX-S) A negative photosensitive resin composition was prepared in the same manner as in Example 1 except that was used, and a color filter substrate having spacers and alignment control protrusions was obtained using this.

  When the pattern on the substrate thus obtained was observed, the shape was good as in Example 1, and an MVA-LCD was produced using a color filter substrate having this spacer and alignment control protrusion. The MVA-LCD has a high viewing angle and does not generate burn-in even when a voltage is applied for a long time, and exhibits good display performance.

  Photoacid generator (manufactured by Ciba Specialty Chemicals, product name; CGI-263) 0.5 g was used in place of 0.5 g of photoacid generator (manufactured by Ciba Specialty Chemicals, product name; CGI-268). Prepared a negative photosensitive resin composition in the same manner as in Example 1, and a color filter substrate having spacers and alignment control projections was obtained using the negative photosensitive resin composition.

  When the pattern on the substrate thus obtained was observed, the shape was good as in Example 1, and an MVA-LCD was produced using a color filter substrate having this spacer and alignment control protrusion. The MVA-LCD has a high viewing angle and does not generate burn-in even when a voltage is applied for a long time, and exhibits good display performance.

  Implemented except that poly (p-vinylphenol) (manufactured by Maruzen Petrochemical Co., Ltd., product name; Marcalinker MS-2) was used instead of cresol novolak resin (product of Asahi Organic Materials Co., Ltd., product name: EP6050G) A negative photosensitive resin composition was prepared in the same manner as in Example 1, and a color filter substrate having spacers and alignment control protrusions was obtained using the negative photosensitive resin composition.

  When the pattern on the substrate thus obtained was observed, the shape was good as in Example 1, and an MVA-LCD was produced using a color filter substrate having this spacer and alignment control protrusion. The MVA-LCD has a high viewing angle and does not generate burn-in even when a voltage is applied for a long time, and exhibits good display performance.

  In the same manner as in Example 1, except that bis (p-tert-butylphenyl) iodonium hexafluorophosphate was used instead of the photoacid generator (manufactured by Ciba Specialty Chemicals, product name; CGI-263). Type photosensitive resin composition was prepared, and a color filter substrate having spacers and alignment control protrusions was obtained using the composition.

  When the pattern on the substrate thus obtained was observed, the shape was good as in Example 1, and an MVA-LCD was produced using a color filter substrate having this spacer and alignment control protrusion. The MVA-LCD has a high viewing angle and does not generate burn-in even when a voltage is applied for a long time, and exhibits good display performance.

[Comparative Example 1]
N-nonafluorobutylsulfonyloxy-1,8-naphthalimide (manufactured by Midori Chemical Co., product name; NAI-109) was used instead of the photoacid generator (product name: CGI-263, manufactured by Ciba Specialty Chemicals). A negative photosensitive resin composition was prepared in the same manner as in Example 2 except that it was used, and a color filter substrate having spacers and alignment control protrusions was obtained using this.

  When the pattern on the substrate thus obtained was observed, the alignment control protrusions had a flat cross-sectional shape on the upper surface, and the MVA-LCD was formed using the color filter substrate having the alignment control protrusions. As a result, this MVA-LCD partially failed in alignment and was inferior in viewing angle characteristics.

[Comparative Example 2]
Instead of a cresol novolac resin (Asahi Organic Materials Co., Ltd., product name: EP6050G), copolymerization was carried out by a known method at a ratio of methacrylic acid / 2-hydroxyethyl methacrylate / benzyl methacrylate = 30/20/50. A negative photosensitive resin composition was prepared in the same manner as in Example 2 except that an acrylic resin was used, and a color filter substrate having spacers and alignment control protrusions was obtained using this.

  Although the negative photosensitive resin composition obtained in this way had good patterning characteristics, when an MVA-LCD was produced using this spacer and a color filter substrate having alignment control projections, there was no burn-in. It has occurred.

[Comparative Example 3]
A negative in the same manner as in Example 1 except that the melamine resin (manufactured by Sanwa Chemical Co., Ltd., product name; Nicalac MW-30HM) and the photoacid generator (manufactured by Ciba Specialty Chemicals Co., Ltd., product name; CGI-263) were removed Type photosensitive resin composition was prepared, and a color filter substrate having spacers and alignment control protrusions was obtained using the composition.

  When the pattern on the substrate thus obtained was observed, the upper surface of the spacer was not flat and the height was almost the same as that of the alignment control projection.

It is explanatory drawing which shows the board | substrate for liquid crystal display panels which formed the alignment protrusion by the method which concerns on this invention. It is explanatory drawing which shows the board | substrate for MVA-LCD which formed the spacer and the processus | protrusion for orientation control by 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 20 ... Color filter side substrate 21A, 21B, 27A, 27B ... Transparent substrate 22 ... Light shielding layer, black Matrix 23R ... Red pixel layer 23G ... Green pixel layer 23B ... Blue pixel layers 24A, 24B, 28A, 28B ... Transparent conductive film 25 ... Liquid crystal alignment control projection 26 ... Spacer 30 ... TFT side substrate 40 ... MVA-LCD

Claims (5)

In a substrate having at least a spacer and an alignment control protrusion constituting a liquid crystal display device that sandwiches liquid crystal between opposing substrates, the spacer and the alignment control protrusion are at least (a) a binder resin,
(B) a crosslinking agent that reacts by the action of an acid,
(C) a compound having an ethylenically unsaturated bond,
(D) a photoacid generator,
(E) formed of a negative photosensitive resin composition containing a photoradical generator,
A substrate having spacers and alignment control protrusions, wherein an exposure wavelength region in which the photo radical generator generates radicals has an exposure wavelength region in which the photo acid generator does not generate acid. (D) the photoacid generator is a compound that generates an acid by light having a wavelength of less than 365 nm and does not generate an acid by light having a wavelength of 365 nm or more;
2. The substrate having spacers and alignment control protrusions according to claim 1, wherein (e) the photo radical generator is a compound that generates radicals by light having a wavelength of 365 nm or more. 3. The substrate having spacers and alignment control protrusions according to claim 1, wherein (d) the photoacid generator is a compound represented by the general formula (1).

(In the formula, R is an optionally substituted alkyl group, an optionally substituted aryl group, an optionally substituted aralkyl group, an optionally substituted alkenyl group, and an optionally substituted heterocyclic ring. Represents a group or an alicyclic group which may be substituted.)   (A) Binder resin contains resin which has phenolic hydroxyl group, The board | substrate which has the spacer and protrusion for alignment control in any one of Claims 1-3 characterized by the above-mentioned.   5. A liquid crystal display device, wherein the substrate provided with the spacer and the alignment control protrusion according to claim 1 is used for at least one of opposing substrates sandwiching liquid crystal.

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