JP2008203854A - Liquid crystal display device and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device which can cope with cell thickness increase under high temperature, and also can suppress a low temperature effervescence phenomenon in a liquid crystal layer under low temperature. <P>SOLUTION: In the liquid crystal display device which has a spacer to retain a gap between substrates, arranged on a liquid crystal holding region of at least one substrate, the spacer is composed of a hardened film of a photosensitive resin composition comprising: a copolymer resin the structural unit of which is a reaction product of a portion of a structural unit derived from (meth)acrylic acids and that derived from hydroxyalkyl (meth)acrylates with a (meth)acryloyl alkylisocyanate compound via their carboxyl groups or hydroxyl groups, and the content of the (meth)acryloyl group of which is 5-95 mol% and the acid value is 5-400 mg KOH/g; a polyfunctional, di- or more functional, photo-polymerizable acrylate monomer or oligomer; an epoxy resin; and an initiator. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a color liquid crystal display device, and more particularly to a liquid crystal display device characterized by maintaining a distance between substrates that sandwich liquid crystal, and a method for manufacturing the same.

  In a liquid crystal display device, a transparent substrate such as glass provided with a transparent electrode is provided with a gap of about 1 to 10 μm, and a liquid crystal substance is sealed therebetween, and the liquid crystal is aligned in a certain direction by a voltage applied between the electrodes. The image is displayed by the transparent part and the opaque part formed by the above. A color liquid crystal display device has three colors of red (R), green (G), and blue (B) corresponding to the three primary colors of light on any transparent electrode substrate, and a black matrix layer appropriately disposed between the three colors ( Bk) is provided, and the three primary colors are added by a liquid crystal shutter action to display a desired color.

  A color filter for a color liquid crystal display device is a transparent substrate in which a transparent substrate, a colored layer, a protective film, and a transparent conductive film are laminated in this order, and an electrode or a thin film transistor facing each position of R, G, B, and Bk is formed. Are held at intervals of several μm, and a liquid crystal material is sealed between them to form a liquid crystal display device.

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

  In an active matrix liquid crystal display device, a thin film transistor (TFT) element is formed on a glass substrate for each pixel, and the shutter action of the liquid crystal of each pixel is controlled by the switching action of each element. A uniform transparent electrode is formed on the counter electrode of these elements.

  These composite oxides called tin oxide, indium oxide and ITO are used for the transparent electrode. There are various methods for forming a transparent electrode, such as vapor deposition, ion plating, and sputtering. The protective film that forms the base of the transparent electrode of the color filter is made of synthetic resin, so the heat resistance of the protective film Therefore, a method capable of forming a film at a relatively low temperature is demanded. For this reason, sputtering is widely used in the production of transparent electrodes for color filters.

  FIG. 4 shows a cross-sectional structure of a liquid crystal display device using TFTs. A liquid crystal display device 41 has a color filter 42 and a counter substrate 43 on which TFTs are formed facing each other with a predetermined interval. They are joined together by a sealing agent 44 in which reinforcing fibers are mixed with epoxy resin or the like. Liquid crystal 45 is sealed in the space formed by the color filter and the TFT substrate, but if the distance between the color filter and the TFT substrate is not accurately maintained, the difference in the optical rotation characteristics of the liquid crystal is caused by the difference in the thickness of the liquid crystal layer. As a result, the liquid crystal may be colored, or color unevenness may occur and display may not be performed correctly. Therefore, a large number of particles or rods made of 3 to 10 μm synthetic resin, glass, alumina, etc., called spacers 46 may be present on the liquid crystal. A spacer such as a photo-curing resin film that has been mixed or patterned has been used to maintain the liquid crystal sandwiching interval.

In the case of using particles or rods as spacers, a large amount of particles of about 100 particles / mm ² are mixed with the liquid crystal, so when mixed with a highly viscous liquid crystal and injected into the sandwiching interval In some cases, the spacers are not uniformly dispersed and the spacers accumulate in a part. When such a phenomenon occurs, the display quality of the portion where the spacers gather is deteriorated, and there is a problem in terms of accurately maintaining the interval. Also, in the method of spraying spacers on the color filter in advance (wet or dry), a special device is required to make the density distribution uniform when spraying, and at the same time, a device that suppresses spacer movement during liquid crystal injection is required. It was.

  Further, in the case of using a spacer such as a patterned curable resin film, the liquid crystal cell is sealed and formed at a temperature of 120 ° C. to 180 ° C. during its production. It is required that a cell gap be ensured, and after the liquid crystal cell is manufactured, taking into account fluctuations in optical characteristics and layer thickness due to temperature changes of the liquid crystal layer during reliability testing and operation, It is required to cope with the increase in cell thickness at high temperature and to prevent low temperature foaming phenomenon in the liquid crystal layer at low temperature.

  The present invention secures a desired cell gap upon thermocompression bonding in a cell set of a liquid crystal display device, and is excellent in reliability and increased in cell thickness at high temperatures after the liquid crystal cell is manufactured. It is another object of the present invention to provide a liquid crystal display device that can cope with the above-described problem and can suppress a low-temperature foaming phenomenon in a liquid crystal layer at a low temperature.

  The liquid crystal display device of the present invention is a liquid crystal display device in which a liquid crystal is sandwiched between two substrates, and a liquid crystal display device in which a spacer for holding a distance between the substrates is provided in a liquid crystal sandwiching region portion on at least one substrate In which the structural unit represented by the following general formulas (1) and (2) is a structural unit obtained by partially reacting with the (meth) acryloylalkylisocyanate compound via its carboxyl group or hydroxyl group. And 5 mol% to 55 mol% of a structural unit derived from the following general formula (1), 5 mol% to 95 mol% of a structural unit derived from the following general formula (2), and a (meth) acryloyl group 5 mol% to 95 mol% inclusive, acid value is 5 mg KOH / g to 400 mg KOH / g, and polystyrene equivalent weight average molecular weight is 10,000 to 1,000,000 And that the copolymer resin is a bifunctional or higher polyfunctional photopolymerizable acrylate monomer or oligomer, an epoxy resin, characterized by comprising a cured film of the photosensitive resin composition comprising the initiator.

(In the formula, R represents hydrogen or an alkyl group having 1 to 5 carbon atoms, and R ₁ represents an alkylene group having 2 to 4 carbon atoms.)
The copolymer resin further contains, as a copolymerization component, 0 mol% to 75 mol% of a structural unit represented by the following general formula (3), and 0 mol% to a structural unit represented by the following general formula (4). It is characterized by containing 75 mol%.

(Wherein R represents hydrogen or an alkyl group having 1 to 5 carbon atoms, R ₂ represents an aromatic carbocycle, and R ₃ represents an alkyl group or an aralkyl group.)
The above-mentioned photocurable resin film is characterized in that a dynamic hardness (DH1) under load obtained from an indentation test at 25 ° C. with a triangular cone indenter using a dynamic microhardness meter is 30 to 60.

  In the method for producing a liquid crystal display device of the present invention, the structural unit represented by the above general formulas (1) and (2) is present in the carboxyl group in at least one liquid crystal sandwiching region portion of the substrate that sandwiches the liquid crystal of the liquid crystal display device. Alternatively, a product obtained by partial reaction with a (meth) acryloylalkylisocyanate compound via a hydroxyl group is used as a structural unit, and a structural unit derived from the general formula (1) is included in an amount of 5 mol% to 55 mol%. 2) containing 5 mol% to 95 mol% of the structural unit derived from 2), containing 5 mol% to 95 mol% of (meth) acryloyl group, having an acid value of 5 mgKOH / g to 400 mgKOH / g, and having a polystyrene equivalent weight A copolymer resin having an average molecular weight of 10,000 to 1,000,000, a bifunctional or higher polyfunctional photopolymerizable acrylate monomer or oligomer, and an epoxy resin After a photosensitive resin composition comprising a resin and an initiator is applied to the thickness of the spacer, a photomask that is not irradiated with light other than the spacer forming portion is provided for exposure, development, and a photocurable resin film as a spacer. After providing the cured film, the cell is assembled and sealed at a temperature of 120 ° C. to 180 ° C.

  The copolymer resin in the above production method further comprises, as a copolymerization component, 0 to 75 mol% of the structural unit represented by the general formula (3) and 0 to the structural unit represented by the general formula (4). It is characterized by containing mol% to 75 mol%.

  In the photocurable resin film in the above production method, the dynamic hardness (DH1) at the time of loading obtained from an indentation test at 25 ° C. with a triangular pan indenter using a dynamic microhardness meter is 30-60. To do.

  The liquid crystal display device of the present invention secures a desired cell gap upon thermocompression bonding, and after the liquid crystal cell is manufactured, is excellent in reliability and can cope with an increase in cell thickness at high temperature. Under low temperature, it is possible to suppress the low temperature foaming phenomenon in the liquid crystal layer.

  The liquid crystal display device of the present invention and the manufacturing method thereof are characterized by spacers. In the liquid crystal display device of the present invention and the manufacturing method thereof, in order to make the storage elastic modulus, loss tangent, Young's modulus, and dynamic hardness that define the spacer, the spacer material is bifunctional with a photopolymerizable acrylate oligomer. This is a photosensitive resin composition to which the above polyfunctional photopolymerizable acrylate monomer or oligomer, epoxy resin and photopolymerization initiator are added.

  As the photopolymerizable acrylate oligomer, those having a molecular weight of about 1000 to 2000 are preferable. Epoxy acrylates such as polyester acrylate, phenol novolac epoxy acrylate, o-cresol novolac epoxy acrylate, polyurethane acrylate, polyether acrylate, oligomer acrylate, alkyd Acrylate, polyol acrylate, melamine acrylate and the like can be mentioned, and specific copolymer resins are preferable as described below.

  Using specific copolymer resins such as those listed below, the storage modulus that defines the spacer, loss tangent, Young's modulus, and dynamic hardness can be used, as well as radically polymerizable groups such as alkali-soluble groups and (meth) acryloyl groups. The content can be controlled, and the curability, alkali solubility, and coating properties can be excellent.

  The specific copolymer resin basically has a structural unit in which a (meth) acryloyl group is introduced into the above general formulas (1) and (2), and, if necessary, the general formula (3), (4) is a copolymer component. Hereinafter, a (meth) acryloyl group means a methacryloyl group or an acryloyl group, and (meth) acrylic acid means methacrylic acid or acrylic acid.

  R in the general formulas (1) to (4) is hydrogen or an alkyl group having 1 to 5 carbon atoms, and examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and n-butyl. Group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group and the like.

  The copolymer component represented by the general formula (1) is a component that contributes to alkali developability, and examples of the monomer used to introduce the structural unit include acrylic acid, methacrylic acid, 2-carboxy- Examples include 1-butene, 2-carboxy-1-pentene, 2-carboxy-1-hexene, 2-carboxy-1-heptene, and the like. The content of the copolymerization component represented by the general formula (1) is adjusted depending on the degree of alkali solubility required for the copolymer resin, and is 5 mol% to 55 mol%, preferably 10 mol% to 25 mol%. Is done.

The copolymer component represented by the general formula (2) is basically a component into which a (meth) acryloyl group is introduced, and R ₁ is an ethylene group, a propylene group, a butylene group, or the like. Monomers used to introduce this structural unit include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxy Examples include butyl methacrylate. The copolymerization component represented by the general formula (2) is a copolymerization component in which a (meth) acryloyl group is introduced through reaction with a (meth) acryloylalkylisocyanate compound via a hydroxyl group, and the content thereof is copolymerization. It is adjusted according to the degree of photopolymerization required for the resin, and is 5 mol% to 95 mol%, preferably 10 mol% to 50 mol%.

The copolymer component represented by the general formula (3) is a component that imparts coating properties to the copolymer resin when it is used for coating film formation, and R ₂ is an aromatic group such as a phenyl group or a naphthyl group. A ring is exemplified. Monomers used for introducing this structural unit include styrene and α-methylstyrene, and the aromatic ring is a halogen atom such as chlorine or bromine, or an alkyl group such as a methyl group or an ethyl group. , An amino group such as an amino group or a dialkylamino group, a cyano group, a carboxyl group, a sulfonic acid group, or a phosphoric acid group. The content of the copolymer component represented by the general formula (3) is 0 mol% to 75 mol%, preferably 5 mol% to 50 mol%.

Furthermore, the copolymerization component represented by the general formula (4) is a component that suppresses alkali developability when the copolymer resin is made into an alkali development type, and R ₃ is an alkyl group having 1 to 12 carbon atoms. And aralkyl groups such as benzyl group and phenylethyl group. Monomers used to introduce this structural unit include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylate-2-ethylhexyl, (meth ) Phenyl acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate, (meth ) Ethethles of (meth) acrylic acid such as phenylethyl acrylate are exemplified. And content of the copolymerization component shown by General formula (4) is 0 mol%-75 mol%, Preferably it is 5 mol%-50 mol%.

  As the monomers used for introducing the structural units of the general formulas (1) to (4), those exemplified above may be used singly or as a mixture.

  As the polymerization solvent used for producing the specific polymer having the structural units of the general formulas (1) to (4), a solvent having no active hydrogen such as a hydroxyl group or an amino group is preferable. Ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, glycol ethers such as diethylene glycol methyl ethyl ether, cellosolv esters such as methyl cellosolve acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, etc., and aromatics Hydrocarbons, ketones, esters and the like can also be used.

  As the polymerization initiator, those generally known as radical polymerization initiators can be used, and specific examples thereof include 2,2′-azobisisobutyronitrile and 2,2′-azobis. Azo compounds such as-(2,4-dimethylvaleronitrile) and 2,2'-azobis- (4-methoxy-2,4-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, tert-butyl peroxypivalate, 1 , 1'-bis- (tert-butylperoxy) cyclohexane and the like, and hydrogen peroxide. When a peroxide is used as the radical polymerization initiator, it may be used as a redox polymerization initiator in combination with a reducing agent.

  In the production of the specific polymer having the structural unit represented by the general formula (1) to the general formula (4), a molecular weight regulator can be used to adjust the weight average molecular weight. Halogenated hydrocarbons such as carbonized carbon, mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan, thioglycolic acid, xanthogens such as dimethylxanthogen disulfide, diisopropylxanthogen disulfide, Examples include terpinolene and α-methylstyrene dimer.

  The specific polymer having the structural units of the general formula (1) to the general formula (4) is any of a random copolymer and a block copolymer of the monomers of the general formula (1) to the general formula (4). It may be.

  In the case of a random copolymer, the blended composition composed of each monomer and catalyst is dropped into a polymerization tank containing a solvent over a period of 2 to 5 hours at a temperature of 80 to 110 ° C., and then aged. Can be polymerized.

  The polystyrene-converted weight average molecular weight (hereinafter, simply referred to as “weight average molecular weight” or “Mw”) of the specific polymer having the structural units of the general formula (1) to the general formula (4) is 10,000 to 1, The acid value is 5 mg KOH / g to 400 mg KOH / g, and the hydroxyl value is 5 mg KOH / g to 400 mg KOH / g.

  The specific copolymer resin can be obtained by reacting a specific polymer having the structural units represented by the general formulas (1) to (4) with a (meth) acryloyl-containing isocyanate compound. The (meth) acryloyl alkyl isocyanate compound is a compound in which a (meth) acryloyl group is bonded to an isocyanate group (—NCO) via an alkylene group having 2 to 6 carbon atoms, specifically 2-acryloylethyl isocyanate, 2 -A methacryloyl ethyl isocyanate etc. are illustrated. 2-Methacryloylethyl isocyanate is commercially available from “Karenz MOI” manufactured by Showa Denko K.K.

  The reaction of the copolymer having the structural unit represented by the general formula (1) to the general formula (4) with the (meth) acryloylalkyl isocyanate compound is carried out by bringing the isocyanate compound into the copolymer solution in the presence of a small amount of a catalyst. This is done by dripping. Examples of the catalyst include dibutyltin laurate, and polymerization inhibitors such as p-methoxyphenol, hydroquinone, naphthylamine, tert-butylcatechol, and 2,3-di-tert-butyl p-cresol are optionally used. used.

  The (meth) acryloylalkyl isocyanate compound is added to the structural unit of the general formula (2) in the specific polymer having the structural units of the general formula (1) to the general formula (4), and is bonded by a urethane bond. A part of the structural unit of the general formula (1) is bonded by an amide bond by releasing carbon dioxide.

  That is, a reaction product of a copolymer having a structural unit represented by general formula (1) or general formula (2) and a (meth) acryloylalkyl isocyanate compound is represented by the following general formula (5).

(In the formula, R and R ₁ have the same meanings as in the general formulas (1) to (4), R ′ represents an alkylene group having 2 to 6 carbon atoms, and a ₁ + a ₂ represents a in the general formula (1); B ₁ + b ₂ has the same meaning as b in formula (2).)
The (meth) acryloylalkylisocyanate compound has a reaction rate of nearly 20 times the reaction with the hydroxyl group in the structural unit of the general formula (2) as compared with the reaction with the carboxyl group in the structural unit of the general formula (1). Therefore, the (meth) acryloyl group is mainly introduced into the structural unit of the general formula (2), and even if a (meth) acryloyl group is partially introduced into the carboxyl group of the structural unit of the general formula (1). Most of the carboxyl groups will remain.

Then, the general formula (2) of 5 mol% to 95 mol% of structural units derived from a, b ₁ is 0 mol% to 10 mol%, b ₂ can be 5 mol% to 95 mol%, and generally of 5 mol% to 55 mol% of the constitutional unit derived from the formula (1), a ₁ to 5 mol% to 55 mol%, a ₂ can be 0 mol% to 10 mol%, of the (meth) acryloyl groups The amount introduced can be adjusted.

  In the copolymer resin, the weight average molecular weight is preferably in the range of 10,000 to 1,000,000, preferably 20,000 to 100,000. If the weight average molecular weight is less than 10,000, the developability is too good to control the pattern shape at the time of pattern exposure, and when the pattern can be produced, the final film thickness is reduced (film reduction). In addition, if it is larger than 1,000,000, there are problems that the viscosity at the time of resist formation becomes too high, the coating suitability is lowered, the developability is deteriorated and the pattern is difficult to be removed.

  The introduction amount of the (meth) acryloyl group is 5 mol% to 95 mol%, preferably 10 mol% to 50 mol%. If the introduction amount is less than 5 mol%, the photocurability is low, and the coating The effect of improving film adhesion and resist characteristics is small.

  The acid value of the copolymer resin is 5 mg KOH / g to 400 mg KOH / g, preferably 10 mg KOH / g to 200 mg KOH / g. The acid value is related to alkali developability, and if the acid value is too low, development is performed. There are problems such as poor adhesion and poor adhesion to the substrate and the color filter resin. Further, if the acid value is too high, the developability is too good, and there is a problem that it is difficult to control the pattern shape during pattern exposure. Further, in the copolymer resin, the hydroxyl group in the general formula (2) does not necessarily need to be left, and can have a hydroxyl value of 0 mgKOH / g to 200 mgKOH / g, but in the case of leaving it, it is effective for adjusting the solubility in a solvent. It is.

  Specific copolymer resins will be exemplified. In any of the following copolymer resins, the structural unit represented by the general formula (1) is 2-hydroxyethyl methacrylate (HEMA) as a monomer, and the structural unit represented by the general formula (2) is acrylic. Using acid (AA) as a monomer and a product obtained by partially reacting with 2-methacryloylethylisocyanate (“Karenz MOI” manufactured by Showa Denko KK) via its carboxyl group or hydroxyl group Further, styrene (St) is used as a monomer as a structural unit represented by the general formula (3), and benzyl methacrylate (BzMA) is used as a monomer as a structural unit represented by the general formula (4). is there.

  Table 1 below shows the copolymer resin composition (mol%), and Table 2 shows the acryloyl group content (mol%), acid value (mg KOH / g), and styrene equivalent weight average molecular weight (Mw).

  In the photosensitive resin composition, the photopolymerizable acrylate oligomer or copolymer resin is contained in a solid content ratio of 5% by weight to 80% by weight, preferably 10% by weight to 50% by weight. If the amount is more than 80% by weight, the viscosity becomes too high, resulting in a decrease in fluidity and a problem in coating property. If the amount is less than 5% by weight, the viscosity becomes too low and the coating film stability after coating and drying is insufficient. There are problems such as loss of exposure and development suitability.

  Next, other components in the photosensitive resin composition will be described.

  Bifunctional or higher polyfunctional photopolymerizable acrylate monomers and oligomers include dipentaerythritol hexaacrylate (DPHA), dipentaerythritol pentaacrylate (DPPA), pentaerythritol triacrylate (PETTA), and trimethylolpropane triacrylate (TMPTA). , Trimethylolpropane triacrylate (TMPTA) ethylene oxide 3 mol adduct, ethylene oxide 6 mol adduct, propylene oxide 3 mol adduct, propylene oxide 6 mol adduct, 1,4-butanediol diacrylate, diethylene glycol diacrylate, neo Examples thereof include pentyl glycol diacrylate. The polyfunctional photopolymerizable acrylate monomer having two or more functions is contained in the photosensitive resin composition in a solid content ratio of 3 wt% to 50 wt%, preferably 5 wt% to 20 wt%. If it is more than 50% by weight, the viscosity becomes too low and the stability of the coating film after coating and drying is insufficient, so that there is a problem that the exposure and development suitability are impaired. There are problems such as poor omission.

  The epoxy resin reacts with unreacted acidic groups present after exposure and development, thereby imparting alkali resistance to the spacer. Examples of the epoxy resin to be used include an ortho cresol novolak type, a bisphenol A novolak type, a phenol novolak type, a bisphenol A type epoxy resin, a cresol novolak type epoxy resin, and the like. Examples of the cresol novolac type epoxy resin include those represented by chemical structural formula 1 and chemical structural formula 2 below.

  Such an epoxy resin is contained in the photosensitive resin composition at a solid content ratio of 1 to 20% by weight, preferably 3 to 15% by weight. When the content of the epoxy resin is less than 1% by weight, sufficient alkali resistance cannot be imparted to the spacer. On the other hand, when the content of the epoxy resin exceeds 20% by weight, the amount of the epoxy resin that is not subjected to photocuring is low. This is not preferable because the storage stability and development suitability of the photosensitive resin composition are lowered. In addition, the epoxy resin is effective for removing the tack of the dry coating film of the photosensitive resin composition, and a sufficient effect is exhibited at an addition amount of about 3% by weight. The epoxy resin contained in the photosensitive resin composition reacts with the acidic group remaining in the spacer without reacting even after exposure and alkali development, and imparts excellent alkali resistance to the spacer by heat treatment. It will be.

  As the initiator, 2-methyl-1- [4-methylthio) phenyl] -2-morpholinopropanone-1, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2,2'-bis (o-chlorophenyl) -4,5,4 ', 5'-tetraphenyl-1,2'-biimidazole, 2,4-diethylthioxanthone, 4,4-bisdiethylaminobenzophenone, etc. Examples include Irgacure 184, Irgacure 907, Irgacure 651, Irgacure 369 (all are trade names of Ciba Specialty Chemicals), Darocur (trade name of Merck), and the like. It is preferable to contain in the range of 0.1 to 20 weight% of solid content individually or in mixture.

  In addition, a surfactant or a silane coupling agent described later may be appropriately added to the photosensitive resin composition.

  The photosensitive resin composition uses diethylene glycol dimethyl ether, 3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, 3-methyl-3-methoxybutanol or the like as a solvent, and has a solid content concentration of 5 wt% to 50 wt%. .

  In the liquid crystal display device of the present invention, the photosensitive resin composition is used and cured to form a spacer. When a liquid crystal cell is produced, it is sealed by applying pressure at a temperature of 120 to 180 ° C. (typically 150 ° C.). It is not preferable to deform, and it has been found that the spacer can be defined by its viscoelasticity, focusing on the fact that the elastic deformation component has as little displacement as possible and can be easily adjusted to the target cell gap.

  That is, the storage elastic modulus (= elastic deformation / component whose shape returns to its original shape) obtained by dynamic viscoelasticity measurement is a specified value or more, and loss tangent (= ratio of deformation / larger plasticity) It is necessary that the amount of deformation component is not more than a specified value. Further, it is necessary that the Young's modulus derived from the stress-strain curve is not less than a specified value at 150 ° C.

  In addition, after manufacturing the liquid crystal cell, there is a reliability test, but if the thermal expansion coefficient of the spacer-forming resin is large relative to the thermal expansion coefficient of the liquid crystal, the cell can not cope, the inside of the cell becomes a vacuum due to atmospheric pressure, Air may enter from the sealed portion and cause a foaming phenomenon. Therefore, the physical properties required for the spacer are required to be in the range of −40 ° C. to 80 ° C. where reliability is generally required for liquid crystal elements.

  That is, the storage elastic modulus (= elastic deformation / component whose shape returns to its original value) obtained by dynamic viscoelasticity measurement in the above temperature range is not more than a specified value, but it is unstable mechanically. But there is a problem, so it must be above a certain value. Further, it is necessary that the loss tangent (= the ratio of deformation / the larger the plastic deformation component is larger) is equal to or less than the specified value. Further, the Young's modulus derived from the stress-strain curve needs to be not more than a specified value at 25 ° C. However, it must be above a certain value because there is a problem even if it becomes unstable mechanically. Further, it is required that the dynamic hardness is in a certain range.

In the liquid crystal display device of the present invention, the hardness of the photocurable resin film forming the spacer is defined by a dynamic storage elastic modulus, a loss elastic modulus, and a loss tangent. Storage elastic modulus (E ′) obtained by dynamic viscoelasticity measurement is 5.0 × 10 ⁹ (Pa) or less, preferably 1.0 × 10 ⁷ (Pa) to 2.0 × 10 ⁹ (Pa), The loss tangent {tan δ = E ″ (loss elastic modulus) / E ′} is 0.1 or less, preferably 0.02 or less, and the storage elastic modulus (E ′ in the range of 120 ° C. to 180 ° C.). ) Is 5.0 × 10 ⁷ (Pa) or more, preferably 1.0 × 10 ⁸ or more, and the loss tangent {tan δ = E ″ (loss elastic modulus) / E ′} is 0.3 or less, preferably Is 0.2 or less. The dynamic storage elastic modulus, loss elastic modulus, and loss tangent employ the following measuring device and measuring method.

Sample for measurement: after coating a photosensitive resin plastic on the PET film surface, pre-baking at 90 ° C. for 3 minutes, then exposing to UV light at 500 mJ / cm ² pattern, 1 in 1% by weight aqueous caustic soda solution After developing for a minute, the film was post-baked at 200 ° C. for 30 minutes to produce a photocurable resin film having a thickness of 50 μm, a width of 5 mm, and a length of 12 mm.

Measuring device: Solid viscoelasticity analyzer RSA-II Rheometrics Measurement attachment (mode): Film tension Measurement frequency: 6.28 rad / s
Measurement temperature: −50 ° C. to 250 ° C.
Measuring method:
(1) Set the sample on the film tension measuring jig.

  (2) The temperature dependence at 6.28 rad / s is measured in the temperature range of −50 ° C. to 250 ° C., and from the temperature dependence data, the temperature range of −40 ° C. to 80 ° C. and 120 ° C. to 180 ° C. The dynamic storage elastic modulus (E ′, Pa) and the dynamic loss elastic modulus (E ″, Pa) are calculated to obtain the dynamic loss elastic modulus (E ″, Pa) / dynamic storage elastic modulus (E ′, Pa). ) = Tan δ.

  In the liquid crystal display device of the present invention, the elastic modulus of the photocurable resin film forming the spacer is defined by the Young's modulus derived from the stress-strain curve obtained from the tensile test of the photocurable resin film. It is 10,000 MPa or less, preferably 500 to 2000 at 150 ° C., and 10 MPa or more, preferably 30 MPa or more at 150 ° C.

Sample for measurement: after coating a photosensitive resin plastic on the PET film surface, pre-baking at 90 ° C. for 3 minutes, then exposing to UV light at 500 mJ / cm ² pattern, 1 in 1% by weight aqueous caustic soda solution After developing for a minute, the film was post-baked at 200 ° C. for 30 minutes to produce a photocurable resin film having a thickness of 50 μm, a width of 5 mm, and a length of 12 mm.

  The Young's modulus at 25 ° C. employs the following measuring device and measuring method.

Measuring device: Tensilon universal testing machine RTA-100 ORIENTEC Co., Ltd. Measuring mode: Film tensile test Measuring temperature: 25 ° C
Measurement method: Place the sample on a film tensile measurement jig and measure the tensile modulus in the vertical direction.

  The Young's modulus at 150 ° C. employs the following measuring device and measuring method.

Measuring device: Solid viscoelasticity analyzer RSA-II Rheometrics Measurement mode: STRAIN RATE SWEEP
Measurement temperature: 150 ° C
Measurement method: Place the sample on a film tensile measurement jig and measure the tensile modulus in the vertical direction.

In the liquid crystal display device of the present invention, the elastic modulus of the photocurable resin film forming the spacer is determined by the displacement depth (D1) at the time of loading obtained from the indentation test using a triangular pyramid indenter using a dynamic microhardness meter and at the time of unloading. According to the displacement depth (D2) of the following formula, DH = 3.8854 × P / (D × D)
D1, D2: Displacement depth (μm)
P: Load (gf)
The dynamic hardness (DH1) under load is 30 to 60, preferably 40 to 50. The following hardness is used for the dynamic hardness.

Sample for measurement: After coating the photosensitive resin composition on the glass surface, pre-baked at 90 ° C. for 3 minutes, then exposed to UV light at 500 mJ / cm ² pattern, and exposed to 1% by weight aqueous caustic soda solution for 1 minute. After being developed after being placed, it was post-baked at 200 ° C. for 30 minutes to produce a photocurable resin film having a thickness of 5 μm.

Measuring device: Dynamic micro hardness tester “DUH-201S” manufactured by Shimadzu Corporation Measurement attachment: Triangular pan indenter 115 ° C.
Measurement method: Apply the load up to the following set load at the following speed, hold the load for the following holding time, and then unload, and determine the indentation displacement depth during loading (D1) and the displacement depth during unloading (D2). Ask.

Set load: 29.4 mN (= 3 gf), load speed: 0.132390 mN / sec, holding time: 10 sec
Based on this measurement result, the dynamic hardness at the time of loading (DH1) and the dynamic hardness at the time of unloading (DH2) are obtained by the above formula. A large dynamic hardness (DH1) under load corresponds to a small indentation displacement depth D, and indicates that the elastic portion including the plastically deformed portion is high. The dynamic hardness (DH2) at the time of unloading is a value indicating the amount of plastic deformation, and becomes infinite when completely restored. Therefore, the larger the value, the smaller the amount of plastic deformation. Therefore, the ratio of the elastic deformation component and the plastic deformation component can be expressed by DH2 / DH1, and for the purpose of the present invention, it is preferable to use a spacer coating film in which this value is as small as possible.

  In the liquid crystal display device of the present invention, by defining the spacer by viscoelasticity as described above, there is little deformation in the cell assembling process, the desired cell gap can be maintained, and the difference in thermal expansion is also absorbed by the viscoelasticity in the spacer. Therefore, the foaming phenomenon at a low temperature can be suppressed.

  Next, a liquid crystal display device will be described. FIG. 1 is a partial sectional view showing an embodiment of a liquid crystal display device in which spacers are formed on a color filter. The liquid crystal display device 1 includes a color filter 2 and a counter substrate 3 such as a TFT facing the color filter 2, and the color filter is formed of a metal such as chromium or an oxide thereof on a glass substrate 4 or a resin. And a black matrix 5 formed of a resin black matrix made of a light-shielding agent, and a colored layer 6 composed of three primary colors of R (red), G (green), and B (blue) with the black matrix as a boundary. Is formed.

  A protective film 7 made of a transparent synthetic resin is provided on the colored layer, and a transparent electrode film 8 made of ITO or the like is formed on the protective film. A spacer 9 made of a photocurable resin film is provided on the transparent electrode film. An alignment film 12 is formed on each surface of the color filter that contacts the liquid crystal of the counter substrate, and is bonded by a sealing material 10 such as an epoxy resin, and the liquid crystal 11 is sealed between the color filter and the counter substrate. The

  FIG. 2 shows a plan view of some of the colored pixels of the color filter. The colored pixels 22 of the color filter 21 are partitioned by a black matrix 23 and are not effective for display around the colored pixels. Since the part is formed, the spacer 24 can be provided in this part. Although the size of the colored pixel varies depending on the screen size and image quality standard, it is a small pixel of about several tens of μm to several hundreds of μm × several tens of μm to several hundreds of μm, for example, about 100 μm × 300 μm. A region for preventing an element formed on the substrate or the like from being visible from the display surface may be provided. If a spacer is provided in such a region, there is no obstacle to the display.

  Further, FIGS. 3A to 3C show a method for forming a spacer using a colored layer of a color filter. First, in the method shown in FIG. 3A, when forming colored pixels of three colors of red, green, and blue, which are colored layers, on the substrate of the color filter 31, the first colored pixel in FIG. After forming the colored pixel 32, the second colored pixel 33 is exposed to light using a photomask that partially covers the red colored pixel, thereby forming a green colored pixel. Blue colored pixels are also formed at the spacer formation positions by using a photomask that can form colored pixels at the positions where the spacers are to be formed as well as the blue photomask that is the colored pixels 34. Next, a transparent electrode film 35 such as an ITO film may be formed, and finally the spacer 36 may be formed. According to this method, since the height of the spacer can be ensured by stacking colored pixels, the spacer formed on the transparent electrode film may be thin.

  In the method shown in FIG. 3B, the black mask Bk is formed on the substrate of the color filter 31 using chromium, and then the colored pixels B, G, and R are partially overlapped to form a pixel. A spacer 36 is formed between them, and the method shown in FIG. 3C is a method of forming a black mask Bk formed using a resin on the substrate of the color filter 31 together with the colored pixels B, G, and R. In this method, the spacer 36 is formed on the black mask Bk after the film formation. In FIGS. 3B and 3C, the transparent electrode film is omitted.

The spacers are arranged as appropriate, one for every four pixels, and one for every one pixel. From the viewpoint of the function as a spacer, the density of the spacer is 0.1% to 5% in volume density, preferably If it is 0.3% to 2%, and if it is too large, the injection efficiency in the liquid crystal injection process is lowered, which is not preferable. As the surface area density, 50 to 2000 m ² / mm ^2, it may preferably be a 500~1000μm ² / mm ^2. If it is too small, it will cause deformation when assembling the cells, and if it is too large, it is not preferable because the injection efficiency in the liquid crystal injection process will decrease.

  The spacer formed by development has a height of 2 μm to 10 μm, for example, a trapezoidal shape, and its end is formed in a rounded spherical shape, a rectangular shape, etc. This is effective for reducing the influence on the orientation and the like in the rubbing process performed after the formation of the orientation film.

Further, if one spacer is provided for a colored pixel of 100 μm × 300 μm, about 33 spacers can be formed in 1 mm ² . This number is smaller than the value of 100 pieces / mm ^2, which is the number when spacers are mixed in a normal liquid crystal, but it is arranged uniformly over the entire display surface. It is possible to achieve the purpose.

  In addition, it is extremely difficult to control the spraying position in normal spacer spraying, but in the present invention, it is possible to produce a spacer with a desired size fixed at a desired position, so that the image quality is excellent. It will be a thing.

  The spacer is preferably formed on the black matrix that defines the colored layer because it does not affect the display quality. The spacer is preferably a photocurable transparent resin film, but is limited to being transparent. It is also possible to form by coloring.

  A method for manufacturing the liquid crystal display device shown in FIG. 1 will be described.

  First, a colored layer is provided on a transparent substrate, and a photosensitive resin composition is applied on the colored layer by an arbitrary coating method such as a spinner method, a roll method, a spray method, or a screen printing method. A mask is used to irradiate ultraviolet rays to cure necessary portions, and a portion of the uncured photosensitive resin that has not been irradiated with ultraviolet rays is dissolved and removed with an alkaline aqueous solution to form a protective film.

  Next, an ITO film having excellent characteristics such as electric resistance is formed on the entire surface of the color filter by DC magnetron sputtering over the entire surface of the color filter.

  Next, on the ITO film, the photosensitive resin composition of the present invention is applied to a thickness corresponding to the sandwiching interval of the liquid crystal layer by an arbitrary application method such as a spinner method, a roll method, a spray method, or a screen printing method, A spacer is formed by irradiating ultraviolet rays using a predetermined photomask to cure the formation portion of the spacer, and dissolving and removing the uncured photosensitive resin in a portion not irradiated with the ultraviolet ray with an alkaline aqueous solution solvent.

  Before providing the photocurable resin film for the spacer, a silane coupling agent or the like can be applied on the ITO film to improve the adhesion. Examples of the silane coupling agent include vinyl silane, acrylic silane, epoxy silane, amino silane, and the like. More specifically, vinyltrichlorosilane, vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, or the like can be used as vinylsilane. Examples of the acrylic silane include γ-methacryloxypropyltrimethoxysilane and γ-methacryloxypropylmethyldimethoxysilane. Examples of the epoxy silane include β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane and the like. Further, aminosilanes include N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethylditrimethoxysilane, γ-aminopropyltriethoxysilane, N -Phenyl-γ-aminopropyltrimethoxysilane or the like can be used. Other silane coupling agents include γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldimethoxysilane, and γ-chloropropylmethyldiethoxysilane. Can be used.

  In addition to the liquid crystal display device shown in FIG. 1, similarly to the liquid crystal display device of FIG. 1, after forming a colored layer and a protective film on a transparent substrate, a spacer is formed on the protective film, including the spacer, An ITO film may be formed to form a liquid crystal display device.

  In this case, by forming the protective film with the same material as the photocurable resin film of the present invention, it is possible to form a spacer having a high adhesion strength with the protective film as the underlayer. In this case, since an ITO film is also formed on the spacer and a conductive connection is formed between the counter electrode, masking is performed on the spacer in advance so that the ITO film is not formed on the spacer, Means for preventing a short circuit may be provided on the counter electrode side, or the formed ITO film may be removed from the spacer by etching.

  In the liquid crystal display device described above, a configuration in which a protective film is indispensable has been shown. However, like the liquid crystal display device in FIG. 1, after forming a colored layer on a transparent substrate, ITO is directly formed on the colored layer. It is good also as a liquid crystal display device of the structure which formed the film | membrane and formed the spacer on the ITO film | membrane surface.

  Further, as described in the examples described later, as in the liquid crystal display device of FIG. 1, after forming a colored layer on a transparent substrate, a spacer is formed on the colored layer, and then the ITO including the spacer is also formed. A film may be formed to form a liquid crystal display device.

  In addition, in all the liquid crystal display devices described above, a method of forming a spacer on the color filter side has been shown, but the spacer is formed on the opposing TFT substrate, and the cell is assembled with the color filter formed in the same manner as described above. Also good.

  According to the present invention, in the liquid crystal display device, a spacer is formed on at least one of the substrates sandwiching the liquid crystal layer so that the two substrates can be held at a predetermined interval. It is not necessary to disperse the particles.

Hereinafter, examples of the present invention will be shown and described in more detail. The copolymer resin (1) used in Example 1 is synthesized by the following method.
(Synthesis of copolymer resin (1))
Composition-Benzyl methacrylate ... 264 g (15 mol%)
・ Styrene: 385 g (37 mol%)
・ Acrylic acid 216g (30mol%)
・ 2-Hydroxyethyl methacrylate 234g (18mol%)
Of azobisisobutyronitrile together with 5 g of azobisisobutyronitrile was dropped into a polymerization tank containing 1000 g of acetic acid-3-methoxybutyl at 100 ° C. over 6 hours to polymerize. To obtain a polymer solution.

  The polymer solution has a solid content of 40% by weight and a viscosity of 1050 mPa · s (30 ° C., B-type viscometer). The acid value of the polymer is 152 mgKOH / g, the hydroxyl value is 90 mgKOH / g, and the weight average molecular weight is It was 37,000 in terms of polystyrene.

  The obtained copolymer consists of 15 mol% of styrene units, 37 mol% of benzyl methacrylate units, 30 mol% of acrylic acid units, and 18 mol% of 2-hydroxyethyl methacrylate units.

Next, to the obtained polymer solution, composition · 2-methacryloylethylisocyanate ··· 270 g
・ Dibutyltin laurate ・ ・ ・ ・ 1g
-Acetic acid-3-methoxybutyl ... 2230g
Was added dropwise over 5 hours.

While the progress of the reaction was monitored by IR (infrared absorption spectrum), the peak due to the isocyanate group at 2200 cm ⁻¹ disappeared.

The obtained reaction solution had a solid content of 26% by weight and a viscosity of 500 mPa · s (30 ° C., B-type viscometer). The polymer had an acid value of 120 mgKOH / g, a hydroxyl value of 5 mgKOH / g, and a weight average. The molecular weight was 45,000 in terms of polystyrene and contained 17 mol% of (meth) acryloyl groups.
(Example 1)
On a glass substrate having a thickness of 1.1 mm (AL material manufactured by Asahi Glass Co., Ltd.), a black matrix made of metallic chromium having a thickness of 100 nm, an aperture ratio of 50%, and each pixel having a size of 20 μm × 40 μm was formed by sputtering.

  On top of that, a red photosensitive resin having the following composition was applied by spin coating (application thickness: 1.5 μm), and then dried in an oven at 70 ° C. for 30 minutes. Next, the coated surface was exposed using a mercury lamp through a photomask having a predetermined pattern, and spray development with water was performed for 1 minute to form a red relief pattern in a region where a red pixel was to be formed. Furthermore, it was then heated at 150 ° C. for 30 minutes to perform a curing process.

  Next, using a green photosensitive resin having the following composition, a green relief pattern was formed in a region where a green pixel was to be formed, in the same process as that for forming a red relief pattern.

  Further, using a blue photosensitive resin having the following composition, a blue relief pattern is formed in a region where a blue pixel is to be formed in the same process as that for forming a red relief pattern, and red (R), green (G) A colored layer composed of three colors of blue (B) was prepared.

(Composition of red photosensitive resin)
・ Pyrazolone red (red pigment): 10 parts by weight ・ Polyvinyl alcohol / 5% stilbazolium quinolium (photosensitive resin): 5 parts by weight ・ Water: 85 parts by weight (composition of green photosensitive resin)
・ Lionol Green 2Y-301 (green pigment) 9 parts by weight Polyvinyl alcohol / 5% stilbazolium quinolium (photosensitive resin) 5 parts by weight Water 86 parts by weight (composition of blue photosensitive resin)
Fastogen blue (blue pigment) 3 parts by weight Polyvinyl alcohol / 5% stilbazolium quinolium (photosensitive resin) 5 parts by weight Water 92 parts by weight

  Next, a photosensitive resin composition for spacer having the following composition was applied on the formed colored layer by a spin coating method (dry film thickness: 5.0 μm).

(Preparation of photosensitive resin composition)
The following composition and copolymer resin synthesized above (1) (solid content: 26 wt%)
… 45.7 parts by weight • Dipentaerythritol pentaacrylate (Sartomer, SR399)… 9.1 parts by weight • Ortho-cresol novolac type epoxy resin (Oilized Shell Epoxy, Epicoat 180S70)… 5.2 parts by weight 2-Benzyl-2-N, N-dimethylamino-1- (4-morpholinophenyl) -1-butanone: 1.3 parts by weight · 2,2′-bis (o-chlorophenyl) -4,5,4 ', 5'-Tetraphenyl-1,2'-biimidazole 1.0 part by weight, polyoxyethylene octylphenyl ether (Nonion HS-210, manufactured by NOF Corporation) 1.9 parts by weight, diethylene glycol dimethyl ether ... 24.8 parts by weight, 3-methoxybutyl acetate ... 12.9 parts by weight are stirred and mixed at room temperature.

(Exposure and development process)
An ultra-high pressure mercury lamp of 2.0 kW by a proximity aligner with a photomask designed to have a desired shape, size and desired spacing at a distance of 100 μm from the coating film of the photosensitive resin composition Was used to irradiate only the spacer formation region on the black matrix with ultraviolet rays for 10 seconds. Subsequently, it was immersed in 0.05% potassium hydroxide aqueous solution (liquid temperature 23 ° C.) for 1 minute and alkali-developed, and only the uncured portion of the coating film of the photosensitive resin composition was removed.

  Thereafter, the substrate was left to stand in an atmosphere of 180 ° C. for 30 minutes to perform a heat treatment to form a fixed spacer, thereby forming a color filter.

  Next, a transparent electrode film was formed on the surface including the fixed spacer by a DC magnetron sputtering method using argon and oxygen as discharge gases at a substrate temperature of 200 ° C. and using ITO as a target.

Next, after forming an alignment film made of polyimide, a cell substrate is assembled by bonding a glass substrate on which a TFT is formed with an epoxy resin as a sealant at 150 ° C. under a pressure of 0.3 kg / cm ² , and a TN liquid crystal is formed. The liquid crystal display device of the present invention was produced by encapsulating.

(Example 2)
On the colored layer formed on the glass substrate obtained in Example 1, a transparent electrode film was formed at a substrate temperature of 200 ° C. using argon and oxygen as discharge gases and using ITO as a target by a DC magnetron sputtering method.

Next, a spacer was formed on the transparent electrode film in the same manner as in Example 1, and then an alignment film made of polyimide was formed. A cell was assembled by applying a pressure of 3 kg / cm ² , and TN liquid crystal was sealed to produce a liquid crystal display device of the present invention.

(Comparative example)
Instead of the photosensitive resin composition in Example 1,
・ Alkali-soluble binder (copolymer based on benzyl methacrylate / styrene / acrylic acid (molecular weight 3000): 30 parts by weight / dipentaerythritol pentaacrylate (SR399, manufactured by Sartomer) 20 parts by weight / ortho-cresol novolak Type epoxy resin (manufactured by Yuka Shell Epoxy Co., Ltd., Epicoat 180S70) 5 parts by weight 2-methyl-1- [4-methylthio) phenyl] -2-morpholinopropanone-1 3 parts by weight diethylene glycol dimethyl ether 30 parts by weight A liquid crystal display device was produced in the same manner as in Example 1 except that 12 parts by weight of 3-methoxybutylacetate was stirred and mixed at room temperature to obtain a photosensitive resin composition.

About the photosensitive resin composition used by Example 1, Example 2, and the comparative example, the dynamic storage elastic modulus, loss elastic modulus, and loss tangent were measured with the measuring method mentioned above. The measurement result about the photosensitive resin composition used in Example 1 and Example 2 is shown in FIG. 5, and the measurement result about the photosensitive resin composition used in Comparative Example 1 is shown in FIG .

From FIG. 5, the storage elastic modulus (E ′) obtained by the dynamic viscoelasticity measurement in the range of −40 ° C. to 80 ° C. of the photocurable resin films in Examples 1 and 2 is 1.0 × 10 ⁹ (Pa ) To 5.0 × 10 ⁹ (Pa), and loss tangent {tan δ = E ″ (loss elastic modulus) / E ′} is in the range of 0.01 to 0.1, and 120 The storage elastic modulus (E ′) in the range of ℃ to 180 ° C. is in the range of 5.0 × 10 ⁷ (Pa) to 1.0 × 10 ⁹ (Pa), and the loss tangent {tan δ = E ″ (loss It can be seen that (elastic modulus) / E ′} is in the range of 0.1 to 0.3.

On the other hand, as can be seen from FIG. 6, the storage elastic modulus (E ′) obtained by the dynamic viscoelasticity measurement in the range of −40 ° C. to 80 ° C. of the photocurable resin film in Comparative Example 1 is 5. 0 × 10 ⁸ (Pa) to 1.0 × 10 ⁹ (Pa), and loss tangent {tan δ = E ″ (loss elastic modulus) / E ′} is 0.05 to 0.15. The storage elastic modulus (E ′) in the range of 120 ° C. to 180 ° C. is in the range of 1.0 × 10 ⁸ (Pa) to 1.0 × 10 ⁹ (Pa), and the loss tangent {tan δ = E ″ (loss elastic modulus) / E ′} is in the range of 0.1 to 0.3.

  That is, it can be seen that the loss tangent in the range of −40 ° C. to 80 ° C. is different from the photocurable resin films in Examples 1 and 2.

  For the photosensitive resin compositions used in Example 1, Example 2, and Comparative Example, the Young's modulus (MPa) at 1% strain derived from the stress-strain curve obtained from the tensile test was measured by the measurement method described above. did. The results are shown in Table 3 below.

  From the table, in Examples 1 and 2, the Young's modulus (MPa) at 25 ° C. is included in the range of 10,000 or less, and the Young's modulus (MPa) at 150 ° C. is in the range of 10 MPa or more. In contrast, the comparative example is found to be out of the Young's modulus (MPa) at 150 ° C.

  About the photosensitive resin composition used in Example 1, Example 2, and the comparative example, the dynamic hardness was measured with the measuring method mentioned above. The results are shown in Table 4 below.

  From the table, it can be seen that in Examples 1 and 2, the dynamic hardness at 25 ° C. is included in the range of 30 to 60, while the comparative example is out of the range.

Next, the fixed spacer size of the liquid crystal display devices manufactured in Example 1, Example 2, and Comparative Example was observed with a microscope. In Examples 1 and ² , it is observed that one spacer for every four pixels is formed on the black matrix, and that the upper base is 100 μm ² and the lower base has a trapezoidal shape with a thickness of 10 μm from the upper base. Moreover, what was formed in the film thickness of 5 micrometers was 4.7 micrometers of desired thickness. On the other hand, the thing of a comparative example is 4.3 micrometers, and it was not a desired thickness, but was a crushed shape.

  About the liquid crystal display device produced in Example 1, Example 2, and the comparative example, about low temperature foaming, when it was cooled for several days from -30 degreeC to -40 degreeC, the thing of Example 1, 2 is not seen. However, small bubbles were generated in the comparative example.

  Moreover, about the liquid crystal display device produced in Example 1, Example 2, and the comparative example, after enclosing the liquid crystal in a cell and annealing at 100 to 120 degreeC, the thing of Example 1, 2 sees a change. Although not, the contrast of the comparative example was lowered.

  Moreover, about the liquid crystal display device produced by Example 1, Example 2, and the comparative example, when the thermal shock test which repeats -30 degreeC-> room temperature-> +80 degreeC each 100 cycles per day was implemented, Example 1, 2 No change was observed in the case of Comparative Example, but a decrease in contrast and foaming occurred in the comparative example.

FIG. 1 is a partial sectional view showing an embodiment of a liquid crystal display device of the present invention. FIG. 2 is a plan view showing a color filter in which spacers are formed. FIG. 3 is a cross-sectional view showing another embodiment of a color filter in which spacers are formed. FIG. 4 is a cross-sectional view of a conventional liquid crystal display device. FIG. 5 shows the measurement results of dynamic storage elastic modulus, loss elastic modulus, and loss tangent for the photosensitive resin compositions used in Examples 1 and 2. FIG. 7 shows the measurement results of the dynamic storage elastic modulus, loss elastic modulus, and loss tangent of the photosensitive resin composition used in the comparative example.

Explanation of symbols

1 is a liquid crystal display device, 2 is a color filter, 3 is a counter substrate, 4 is a glass substrate, 5 is a black matrix, 6 is a colored layer, 7 is a protective film, 8 is a transparent electrode film, 9 is a spacer, 10 is a sealing material , 11 is a liquid crystal, 12 is an alignment film, 21 is a color filter, 22 is a colored pixel, 23 is a black matrix, 24 is a spacer, 31 is a color filter, 32 is a colored pixel of the first color, and 33 is colored of the second color. Pixel, 34 is a second color pixel, 35 is a transparent electrode film, 36 is a spacer, 41 is a liquid crystal display device, 42 is a color filter, 43 is a counter substrate, 44 is a sealing material, 45 is a liquid crystal, and 46 is a spacer. is there.

Claims (6)

A liquid crystal display device in which a liquid crystal is sandwiched between two substrates, wherein a spacer for maintaining a distance between the substrates is provided in a liquid crystal sandwiching region portion on at least one substrate. The structural unit represented by the formula (1) or (2) is a product obtained by partially reacting with the (meth) acryloylalkyl isocyanate compound via the carboxyl group or hydroxyl group, and the following general formula (1) 5 mol% to 55 mol%, 5 mol% to 95 mol% of a structural unit derived from the following general formula (2), and 5 mol% to 95 mol% of (meth) acryloyl group A copolymer resin having an acid value of 5 mgKOH / g to 400 mgKOH / g and a weight average molecular weight in terms of polystyrene of 10,000 to 1,000,000, and bifunctional A liquid crystal display device comprising a polyfunctional photopolymerizable acrylate monomer or oligomer of above, an epoxy resin, that a cured film of the photosensitive resin composition comprising the initiator.

(In the formula, R represents hydrogen or an alkyl group having 1 to 5 carbon atoms, and R ₁ represents an alkylene group having 2 to 4 carbon atoms.) As a copolymerization component, the copolymer resin further contains 0 to 75 mol% of a structural unit represented by the following general formula (3) and 0 to 75 mol of a structural unit represented by the following general formula (4). The liquid crystal display device according to claim 4, comprising:

(Wherein R represents hydrogen or an alkyl group having 1 to 5 carbon atoms, R ₂ represents an aromatic carbocycle, and R ₃ represents an alkyl group or an aralkyl group.) In the photocurable resin film, the dynamic hardness (DH1) under load obtained from an indentation test at 25 ° C. with a triangular cone indenter using a dynamic microhardness meter is 30 to 60, Or the liquid crystal display device of Claim 2. The structural unit represented by the following general formulas (1) and (2) is attached to at least one liquid crystal sandwiching region portion of the substrate sandwiching the liquid crystal of the liquid crystal display device via its carboxyl group or hydroxyl group (meth) acryloylalkyl isocyanate. A product partially reacted with the compound is used as a structural unit, the structural unit derived from the following general formula (1) is 5 mol% to 55 mol%, and the structural unit derived from the following general formula (2) is 5 mol%. -95 mol%, a (meth) acryloyl group is contained in an amount of 5 to 95 mol%, the acid value is 5 mgKOH / g to 400 mgKOH / g, and the polystyrene-equivalent weight average molecular weight is 10,000 to 1,000,000. A photosensitive resin comprising a copolymer resin having a molecular weight of 000, a polyfunctional photopolymerizable acrylate monomer or oligomer having two or more functions, an epoxy resin, and an initiator. After applying the composition to the thickness of the spacer, a photomask that is not irradiated with light other than the spacer formation portion is provided, exposed, developed, and a cured film made of a photocurable resin film is provided as a spacer, and then the cell assembly is performed. At this time, the liquid crystal display device is manufactured by sealing at a temperature of 120 ° C. to 180 ° C.

(In the formula, R represents hydrogen or an alkyl group having 1 to 5 carbon atoms, and R ₁ represents an alkylene group having 2 to 4 carbon atoms.) As a copolymerization component, the copolymer resin further contains 0 to 75 mol% of a structural unit represented by the following general formula (3) and 0 to 75 mol of a structural unit represented by the following general formula (4). The manufacturing method of the liquid crystal display device of Claim 4 characterized by the above-mentioned.

(Wherein R represents hydrogen or an alkyl group having 1 to 5 carbon atoms, R ₂ represents an aromatic carbocycle, and R ₃ represents an alkyl group or an aralkyl group.) The photocuring resin film has a dynamic hardness (DH1) under load obtained from an indentation test at 25 ° C. with a triangular cone indenter using a dynamic microhardness meter of 30 to 60, Or the manufacturing method of the liquid crystal display device of Claim 5.

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