JP4022194B2 - Curable resin composition for liquid crystal display element, sealing agent for liquid crystal display element, sealing agent for liquid crystal display element, vertical conduction material for liquid crystal display element, and liquid crystal display device - Google Patents

Description

The present invention relates to a liquid crystal display element and a component that dissolves in the liquid crystal material when used as at least one of a sealing agent for liquid crystal display elements, a sealing agent for liquid crystal display elements, and a vertical conduction material for liquid crystal display elements. Since there is little color unevenness in the liquid crystal display since it does not cause liquid crystal contamination, a curable resin composition for a liquid crystal display element that is particularly suitable for manufacturing a liquid crystal display device by a dropping method, and a liquid crystal display element using the same The present invention relates to a sealing agent for liquid crystal, a sealing agent for liquid crystal display element, a vertical conduction material for liquid crystal display element, and a liquid crystal display device.

Conventionally, a liquid crystal display element such as a liquid crystal display cell forms a cell by facing two transparent substrates with electrodes facing each other at a predetermined interval and sealing the periphery with a sealing agent made of a curable resin composition. However, the liquid crystal was injected into the cell from a liquid crystal injection port provided in a part of the cell, and the liquid crystal injection port was sealed using a sealing agent or a sealing agent.

In this method, first, a seal pattern provided with a liquid crystal injection port using a thermosetting sealant is formed on one of two transparent substrates with electrodes by screen printing, and prebaked at 60 to 100 ° C. Dry the solvent in the sealant. Next, alignment is performed with the two substrates facing each other with a spacer interposed therebetween, and the gap in the vicinity of the seal is adjusted by performing hot pressing at 110 to 220 ° C. for 10 to 90 minutes, and then in an oven at 110 to 220 ° C. Heat for 10 to 120 minutes to fully cure the sealant. Next, liquid crystal was injected from the liquid crystal injection port, and finally, the liquid crystal injection port was sealed using a sealing agent to produce a liquid crystal display element.

However, according to this manufacturing method, positional displacement, gap variation, and decrease in adhesion between the sealing agent and the substrate occur due to thermal strain; residual solvent thermally expands to generate bubbles, resulting in gap variation and seal path. The seal curing time is long; the pre-baking process is complicated; the usable time of the sealant is short due to the volatilization of the solvent; and it takes time to inject liquid crystal. In particular, in a large liquid crystal display device in recent years, it takes a very long time to inject liquid crystal.

On the other hand, a manufacturing method of a liquid crystal display element called a dripping method using a photocuring / thermosetting sealant has been studied. In the dropping method, first, a rectangular seal pattern is formed on one of the two transparent substrates with electrodes by screen printing. Next, fine droplets of liquid crystal are dropped onto the entire surface of the transparent substrate in an uncured state, and the other transparent substrate is immediately overlaid, and the seal portion is irradiated with ultraviolet rays for temporary curing. After that, heating is performed at the time of liquid crystal annealing to perform main curing, and a liquid crystal display element is manufactured. If the substrates are bonded together under reduced pressure, a liquid crystal display element can be manufactured with extremely high efficiency. In the future, this dripping method is expected to become the mainstream of liquid crystal display manufacturing methods.

As a curable resin composition used as a conventional sealing agent, for example, Patent Document 1 discloses an adhesive mainly composed of a partial (meth) acrylate of a bisphenol A type epoxy resin. Moreover, it is disclosed by patent document 2, patent document 3, patent document 4, patent document 5, etc., and patent document 6 discloses what has (meth) acrylic acid ester resin as a main component.

However, these curable resin compositions tend to exhibit a polarity value close to that of a liquid crystal material, and both have a property of being easily compatible. Therefore, in a liquid crystal display element assembled using a sealing agent comprising these curable resin compositions, the components of the sealing agent are eluted in the liquid crystal, resulting in disordered alignment of the liquid crystal in the periphery of the sealing agent, resulting in color unevenness. May cause display defects. In particular, in the dropping method, since there is a process in which an uncured sealant directly contacts liquid crystal, liquid crystal contamination due to such a sealant component has been a serious problem. In addition, when the curable resin composition similar to that of the sealing agent is used as the vertical conduction material, there is a problem similar to that of the sealing agent.

Japanese Patent Laid-Open No. 6-160872 JP-A-1-243029 JP 7-13173 A Japanese Patent Laid-Open No. 7-13174 Japanese Patent Laid-Open No. 7-13175 Japanese Patent Laid-Open No. 7-13174

In view of the present situation, the present invention, when used as at least one of a liquid crystal display element and a liquid crystal display element sealing agent, a liquid crystal display element sealing agent, and a liquid crystal display element vertical conduction material in the production thereof, Since there is little color unevenness in the liquid crystal display because it does not dissolve in the liquid crystal material and cause liquid crystal contamination, a curable resin composition for a liquid crystal display element that is particularly suitable for manufacturing a liquid crystal display device by a dropping method, It aims at providing the used sealing agent for liquid crystal display elements, sealing agent for liquid crystal display elements, the vertical conduction material for liquid crystal display elements, and a liquid crystal display device.

The present invention is a curable resin composition for a liquid crystal display element containing a (meth) acrylic acid-modified epoxy resin obtained by reacting a crystalline epoxy resin and (meth) acrylic acid.
In this specification, (meth) acrylic acid means acrylic acid or methacrylic acid. In the present specification, the crystalline resin means a resin having a sharp and clear melting point peak when the differential heat is measured by a differential scanning calorimeter, and having a crystallinity exceeding 10%. The term “resin” means a resin having no sharp and clear melting point peak and a crystallinity of 10% or less when differential heat is measured by a differential scanning calorimeter.
The present invention is described in detail below.

The curable resin composition for liquid crystal display elements of the present invention (hereinafter also simply referred to as curable resin composition) contains a (meth) acrylic acid-modified epoxy resin as a curable resin component.
Since the (meth) acrylic acid-modified epoxy resin has a (meth) acryl group and an epoxy group in the molecule, it can be cured by light or heat. Therefore, if the curable resin composition for a liquid crystal display element of the present invention is used, it can be used, for example, by temporarily irradiating with light and then temporarily curing by heating. It is suitable for a sealing agent in the case of manufacturing.

The (meth) acrylic acid-modified epoxy resin can be produced by reacting an epoxy resin and (meth) acrylic acid.
As a result of intensive studies, the present inventors have found that if a crystalline epoxy resin is used as an epoxy resin as a raw material, the liquid crystal non-contamination property of the resulting curable resin composition for liquid crystal display elements can be improved. The present invention has been completed.
This is because the crystalline epoxy resin generally has a high purity and a small content of impurities, and the crystallinity of the (meth) acrylic acid-modified epoxy resin obtained by using the crystalline epoxy resin as a raw material is increased. Since the interaction becomes strong, the liquid crystal is hardly contaminated even when the uncured resin and the liquid crystal come into contact with each other in the dropping method.

Examples of the crystalline epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, hydroquinone type epoxy resin, biphenyl type epoxy resin, stilbene type epoxy resin, sulfide type epoxy resin, and ether type. Examples thereof include epoxy resins, naphthalene type epoxy resins, and derivatives thereof.

The crystalline epoxy resin preferably has a melting point of 140 ° C. or lower. If the temperature exceeds 140 ° C., gelation may occur during the denaturation reaction. A more preferred upper limit is 120 ° C. Moreover, a preferable minimum is 40 degreeC. If it is lower than 40 ° C., the crystallinity may be lowered.

Other than the above (meth) acrylic acid, the reactive double bond having the same effect as (meth) acrylic acid is not particularly limited, and examples thereof include crotonic acid, cinnamic acid, and sorbic acid.

The method of reacting the crystalline epoxy resin with (meth) acrylic acid is not particularly limited, and can be performed by a conventionally known method.
When the crystalline epoxy resin and (meth) acrylic acid are reacted, it is preferable to use a basic catalyst, and the basic catalyst is not particularly limited, and examples thereof include N, N-dimethylphenylamine and triethylamine. , Triphenylphosphine, iron chloride, zinc chloride, vanadium chloride and the like.
Moreover, when making the said crystalline epoxy resin and (meth) acrylic acid react, 1-0.5 equivalent of (meth) acrylic acid is made to react with respect to 1 equivalent of epoxy groups in presence of the said base catalyst. Is preferred.

The (meth) acrylic acid-modified epoxy resin is preferably a crystalline (meth) acrylic acid-modified epoxy resin. When the (meth) acrylic acid-modified epoxy resin is crystalline, the interaction between molecules becomes strong. Therefore, even if the uncured resin and the liquid crystal come into contact with each other in the dropping method, the liquid crystal is hardly contaminated.

The (meth) acrylic acid-modified epoxy resin preferably has a melting point of 80 ° C. or lower. If it exceeds 80 ° C., it may be necessary to heat at a high temperature during compounding, which may cause problems such as gelation. A preferred lower limit is 40 ° C. When the temperature is lower than 40 ° C., the cohesive force is lowered, and the adhesiveness of the cured product obtained by curing the curable resin composition of the present invention may be lowered.

The (meth) acrylic acid-modified epoxy resin preferably has a total of 5 to 10 sulfur atoms and oxygen atoms in the resin skeleton. If it is less than 5, the polarity as a molecule is low and the liquid crystal is likely to be contaminated. If it exceeds 10, moisture resistance may be inferior.

In the (meth) acrylic acid-modified epoxy resin, the preferable lower limit of the value obtained by dividing the total of sulfur atoms and oxygen atoms in the resin skeleton by the total number of atoms is 0.08, and the preferable upper limit is 0.14. If it is less than 0.08, the polarity may be low and the liquid crystal may be easily contaminated. If it exceeds 0.14, the moisture resistance may be inferior.

The preferable lower limit of the amount of the (meth) acrylic acid-modified epoxy resin in the curable resin composition of the present invention is 10% by weight, and the preferable upper limit is 50% by weight. If it is less than 10% by weight, the adhesiveness of the cured product may be lowered, and if it exceeds 50% by weight, the composition may be crystallized.

The curable resin composition of the present invention may further contain a photopolymerization initiator, a thermosetting agent, a filler, a coupling agent, and the like.
The photopolymerization initiator is not particularly limited as long as it can polymerize the (meth) acrylic acid-modified epoxy resin by light irradiation, but those having a reactive double bond and a photoreaction initiation part are suitable. . Such a photopolymerization initiator can give sufficient reactivity when blended in the curable resin composition of the present invention and does not elute into the liquid crystal and contaminate the liquid crystal. Of these, benzoin (ether) compounds having a reactive double bond and a hydroxyl group and / or a urethane bond are preferred. The benzoin (ether) compounds represent benzoins and benzoin ethers.

Examples of the reactive double bond include residues such as an allyl group, a vinyl ether group, and a (meth) acryl group. When used as a photopolymerization initiator of the curable resin composition of the present invention, the reactive double bond is reactive. A (meth) acrylic residue is preferred because of its height. By having such a reactive double bond, the weather resistance is improved when blended into the curable resin composition.

The said benzoin (ether) type compound should just have any one of a hydroxyl group and a urethane bond, and may have both. When the benzoin (ether) compound does not have either a hydroxyl group or a urethane bond, it may be eluted into the liquid crystal before curing when blended in the curable resin composition.

In the benzoin (ether) compounds, the reactive double bond and hydroxyl group and / or urethane bond may be located at any part of the benzoin (ether) skeleton, but are represented by the following general formula (1). Those having a molecular skeleton are preferred. If a compound having such a molecular skeleton is used as a photopolymerization initiator, the residue is reduced and the amount of outgas can be reduced.

In the formula, R represents hydrogen or a residual aliphatic hydrocarbon chain having 4 or less carbon atoms. When R is an aliphatic hydrocarbon residual chain having more than 4 carbon atoms, the storage stability when a photopolymerization initiator is added increases, but the reactivity may decrease due to steric hindrance of the substituent.
Examples of the benzoin (ether) compounds having a molecular skeleton represented by the general formula (1) include compounds represented by the following general formula (2).

In the formula, R represents hydrogen or an aliphatic hydrocarbon residue having 4 or less carbon atoms, X represents a residue of a bifunctional isocyanate derivative having 13 or less carbon atoms, and Y represents an aliphatic hydrocarbon residue having 4 or less carbon atoms. This represents a residue having an atomic ratio of carbon and oxygen constituting a group or residue of 3 or less. When X is a residue of a bifunctional isocyanate derivative having more than 13 carbon atoms, it may be easily dissolved in the liquid crystal, and Y may be an aliphatic hydrocarbon residue having more than 4 carbon atoms or an atomic ratio of carbon to oxygen. If the residue is more than 3, it may be easily dissolved in the liquid crystal.

Other examples of the photopolymerization initiator include benzophenone, 2,2-diethoxyacetophenone, benzyl, benzoyl isopropyl ether, benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, thioxanthone, phenyl-2-hydroxy-2-propyl You may use together single or 2 types or more, such as a ketone.

The minimum with the preferable compounding quantity of the said photoinitiator is 0.1 weight part with respect to 100 weight part of said (meth) acrylic acid modified epoxy resins, and a preferable upper limit is 10 weight part. If it is less than 0.1 parts by weight, the ability to initiate photopolymerization may be insufficient and the effect may not be obtained. If it exceeds 10 parts by weight, a large amount of unreacted photopolymerization initiator may remain, Weather resistance may deteriorate. A more preferred lower limit is 1 part by weight, and a more preferred upper limit is 5 parts by weight.

The above-mentioned thermosetting agent is for reacting and crosslinking epoxy groups and acrylic groups which are thermosetting functional groups in the (meth) acrylic acid-modified epoxy resin by heating. It has the role of improving adhesiveness and moisture resistance. As the thermosetting agent, a latent curing agent having a melting point of 100 ° C. or higher is preferably used. When a curing agent having a melting point of less than 100 ° C. is used, the storage stability may be remarkably deteriorated.

Examples of such a curing agent include hydrazide compounds such as 1,3-bis [hydrazinocarbonoethyl-5-isopropylhydantoin], dicyandiamide, guanidine derivatives, 1-cyanoethyl-2-phenylimidazole, N- [2- ( 2-methyl-1-imidazolyl) ethyl] urea, 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyl-s-triazine, N, N′-bis (2-methyl- 1-imidazolylethyl) urea, N, N ′-(2-methyl-1-imidazolylethyl) -adipamide, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole Imidazole derivatives such as modified aliphatic polyamines, tetrahydrophthalic anhydride, ethylene glycol Scan anhydride such as (anhydrotrimellitate), addition products such as the various amines and epoxy resins. These may be used alone or in combination of two or more.

The minimum with the preferable compounding quantity of the said thermosetting agent is 1 weight part with respect to 100 weight part of said (meth) acrylic acid modified epoxy resins, and a preferable upper limit is 50 weight part. If it is out of this range, the adhesiveness and chemical resistance of the cured product will be lowered, and the liquid crystal characteristics may be deteriorated in a high temperature and high humidity operation test. A more preferred lower limit is 4 parts by weight, and a more preferred upper limit is 30 parts by weight.
Further, as the thermosetting agent, when using a coating curing agent in which the surface of the solid curing agent particle is coated with fine particles or the like, even when the curable resin composition of the present invention is a one-pack type, This is particularly preferable because high storage stability can be obtained.

Although it does not specifically limit as said filler, For example, the at least 1 sort (s) of inorganic filler selected from the group which consists of a hydrous magnesium oxalate, a calcium carbonate, an aluminum oxide, and a silica is suitable. The particle size of these fillers is preferably 1.5 μm or less. In this case, the preferable minimum of the compounding quantity of the said filler in the curable resin composition of this invention is 8 weight%, and a preferable upper limit is 20 weight%.

The silane coupling agent mainly serves as an adhesion aid for favorably bonding the curable resin composition and the glass substrate or the like. In the case where the curable resin composition of the present invention contains a small amount of non-conductive filler for the purpose of improving adhesiveness due to stress dispersion effect, improving linear expansion coefficient, etc., the non-conductive filler and the resin In order to improve the interaction with the silane, it may be used in a method of treating the surface of the non-conductive filler with a silane coupling agent.

As said silane compound, what has at least 1 functional group shown by the following A group and at least 1 functional group shown by the following B group is suitable.

Specific examples include γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-isocyanatopropyltrimethoxysilane. These silane compounds may be used alone or in combination of two or more.

By using the silane compound having such a structure as a silane coupling agent, the curable resin composition of the present invention can improve the adhesion to a substrate and the like, and through the functional group shown in Group B. Thus, the silane compound can be chemically bonded to the (meth) acrylic acid-modified epoxy resin to prevent outflow into the liquid crystal.
In addition, when the curable resin composition of this invention mix | blends such a silane coupling agent, heat processing are performed after a silane coupling agent mixing | blending. By the heat treatment, the silane compound is chemically bonded to the (meth) acrylic acid-modified epoxy resin via the functional group represented by Group B.

The curable resin composition of the present invention preferably has a volume resistance of 1 × 10 ¹³ Ω · cm or more after curing. If it is less than 1 × 10 ¹³ Ω · cm, it means that the curable resin composition contains ionic impurities, and the ionic impurities are eluted into the liquid crystal when energized, affecting the liquid crystal driving voltage. Giving rise to display unevenness.

The curable resin composition of the present invention preferably has a dielectric constant (relative dielectric constant) of 3 or more at 100 kHz after curing. The dielectric constant of the liquid crystal is usually about 10 for ε // (parallel) and about 3.5 for ε⊥ (vertical). Therefore, if the dielectric constant is less than 3, the curable resin composition is eluted in the liquid crystal. However, this may affect the liquid crystal driving voltage and cause display unevenness.

In the curable resin composition of the present invention, the preferable lower limit of the glass transition temperature after curing is 80 ° C., and the preferable upper limit is 150 ° C. If it is less than 80 ° C., it may be inferior in moisture resistance (high temperature and humidity resistance), and if it exceeds 150 ° C., it may become too rigid and inferior in adhesion to the substrate.

The curable resin composition of the present invention preferably has an extraction water ion conductivity of 50 μS / cm or less before curing. If it exceeds 50 μS / cm, it means that the curable resin composition of the present invention contains ionic impurities, and the ionic impurities are eluted in the liquid crystal, affecting the liquid crystal driving voltage and causing display unevenness. Cause. More preferably, it is 30 μS / cm or less.
The extracted water ion conductivity is obtained by dissolving the resin composition in a solvent, extracting the solution with pure water, and measuring the conductivity of the pure water with a conductivity meter (for example, ES-12 manufactured by Horiba, Ltd.). It can obtain by measuring using.

Further, the curable resin composition of the present invention preferably has a specific resistance before curing is ^{1.0 × 10 6 ~1.0 × 10 10} Ω · cm. If it is less than 1.0 × 10 ⁶ Ω · cm, when these are eluted into the liquid crystal, the liquid crystal driving voltage is affected, causing display unevenness. If it exceeds 1.0 × 10 ¹⁰ Ω · cm, elution into the liquid crystal may increase or adhesion to the substrate may be poor.

It does not specifically limit as a method to manufacture the curable resin composition of this invention, The said photoinitiator, thermosetting agent, filler, coupling which are mix | blended with the said (meth) acrylic-acid modified epoxy resin as needed. Examples include a method of mixing a predetermined amount of an agent and the like by a conventionally known method. At this time, in order to remove the ionic impurities contained, it may be contacted with an ion-adsorbing solid.

Since the curable resin composition of the present invention contains the above (meth) acrylic acid-modified epoxy resin as a curable resin component, when used as a sealing agent for liquid crystal display elements or a sealing agent for liquid crystal display elements, liquid crystal is used. Less contaminated. In particular, it is suitable for manufacturing a liquid crystal display device by a dropping method.
The sealing agent for liquid crystal display elements and the sealing agent for liquid crystal display elements which use the curable resin composition of this invention are also one of this invention.

In addition, in the liquid crystal display device, a vertical conduction material is generally used in order to make vertical conduction between opposing electrodes on two transparent substrates. The vertical conduction material is usually configured by containing conductive fine particles in a curable resin composition.
The vertical conduction material for a liquid crystal display element comprising the curable resin composition of the present invention and conductive fine particles is also one aspect of the present invention.

The conductive fine particles are not particularly limited. For example, metal fine particles; those obtained by subjecting resin substrate fine particles to metal plating (hereinafter referred to as metal plating fine particles); Those coated (hereinafter referred to as coated metal plated fine particles); and those metal fine particles, metal plated fine particles, and coated metal plated fine particles having protrusions on the surface. Especially, since it is excellent in the uniform dispersibility in a resin composition and electroconductivity, the metal plating fine particle and covering metal plating fine particle which gave gold plating are preferable.

The minimum with the preferable compounding quantity with respect to 100 weight part of the said curable resin composition of the said electroconductive fine particles is 0.2 weight part, and a preferable upper limit is 5 weight part.

The method for producing the vertical conduction material for a liquid crystal display element of the present invention is not particularly limited. For example, the curable resin composition, the conductive fine particles and the like are blended so as to have a predetermined blending amount, and a vacuum planetary type is used. The method of mixing with a stirring apparatus etc. is mentioned.

Furthermore, a liquid crystal display device using at least one of the sealing agent for liquid crystal display elements of the present invention, the sealing agent for liquid crystal display elements of the present invention, and the vertical conduction material for liquid crystal display elements of the present invention is also included in the present invention. One.

As a method for producing the liquid crystal display device of the present invention using at least one of the sealing agent for liquid crystal display elements of the present invention, the sealing agent for liquid crystal display elements of the present invention, and the vertical conduction material for liquid crystal display elements of the present invention. It is not specifically limited, For example, it can manufacture with the following method.
First, on one of two transparent substrates with electrodes (inorganic glass or plastic plate) such as an ITO thin film, the liquid crystal display element sealant of the present invention is formed into a predetermined pattern in which the liquid crystal inlet is released. Apply. Examples of the application method include screen printing and dispenser application. Furthermore, the vertical conduction material for a liquid crystal display element of the present invention is applied onto a predetermined electrode on the other transparent substrate. Examples of the application method include screen printing and dispenser application. Instead of using a vertical conduction material, it is possible to incorporate conductive fine particles in the sealant to achieve vertical conduction. Next, the two transparent substrates are opposed to each other via a spacer, and are overlapped while aligning. Thereafter, the sealing portion and the vertical conduction material portion of the transparent substrate are temporarily fixed by irradiation with ultraviolet rays, and further cured by heating in an oven at 100 to 200 ° C. for 1 hour to complete the curing. Finally, liquid crystal is injected from the liquid crystal injection port, and the injection port is closed using the sealing agent for a liquid crystal display element of the present invention to produce a liquid crystal display device.

Moreover, as a manufacturing method of the liquid crystal display device by a dripping method, for example, the liquid crystal display element sealant of the present invention is formed into a rectangular shape by screen printing, dispenser application, etc. on one of two transparent substrates with electrodes such as an ITO thin film. The seal pattern is formed. Further, a vertical conduction pattern is formed on a predetermined electrode on the other transparent substrate by screen printing, dispenser application or the like of the vertical conduction material for a liquid crystal display element of the present invention. Instead of using a vertical conduction material, it is possible to incorporate conductive fine particles in the sealant to achieve vertical conduction. Next, a liquid crystal micro-droplet is dropped onto the entire surface of the transparent substrate frame in an uncured state of the sealant, and the other transparent substrate is immediately overlapped in an uncured state of the vertically conductive material, and the seal portion and the vertically conductive material portion Preliminary curing is performed by irradiating with UV rays. After that, heating is performed at the time of liquid crystal annealing and main curing is performed to manufacture a liquid crystal display device.

According to the present invention, when used as at least one of a liquid crystal display element and a sealing agent for liquid crystal display elements, a sealing agent for liquid crystal display elements, and a vertical conduction material for liquid crystal display elements in the production thereof, the component is contained in the liquid crystal material. Since there is little color unevenness in the liquid crystal display because it does not dissolve in the liquid crystal and cause liquid crystal contamination, a curable resin composition for a liquid crystal display element that is particularly suitable for manufacturing a liquid crystal display device by a dropping method, and a liquid crystal using the same A sealing agent for a display element, a sealing agent for a liquid crystal display element, a vertical conduction material for a liquid crystal display element, and a liquid crystal display device can be provided.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

( Reference Example 1 )
1000 parts by weight of a crystalline epoxy resin represented by the following general formula (3) (manufactured by Nippon Steel Chemical Co., Ltd .: YSLV-80XY, melting point 78 ° C.), 2 parts by weight of p-methoxyphenol as a polymerization inhibitor, and triethylamine as a reaction catalyst 2 parts by weight and 200 parts by weight of acrylic acid were reacted at 90 ° C. with stirring under reflux for 5 hours while feeding air, to obtain an amorphous (meth) acrylic acid-modified epoxy resin (50% partially acrylated product).

In the formula, G represents a glycidyl group.

134 parts by weight of trimethylolpropane, 0.2 part by weight of BHT as a polymerization initiator, 0.01 part by weight of dibutyltin dilaurate and 666 parts by weight of isophorone diisocyanate as reaction catalysts were added and reacted at 60 ° C. with stirring under reflux for 2 hours. Next, 25.5 parts by weight of 2-hydroxyethyl acrylate and 111 parts by weight of glycidol were added, and the mixture was reacted for 2 hours while stirring at 90 ° C. while feeding air. 100 parts by weight of the obtained resin was filtered through a column packed with 10 parts by weight of a natural combination of quartz and kaolin (manufactured by Hoffman Mineral Co., Ltd., Siritin V85) in order to adsorb ionic impurities in the reaction product. A modified partially acrylated product was obtained.

40 parts by weight of the obtained (meth) acrylic acid-modified epoxy resin, 20 parts by weight of urethane-modified partially acrylated product, 15 parts by weight of hydrazide-based curing agent (Ajinomoto Fine Techno Co., Amicure VDH) as a latent thermosetting agent, photopolymerization As an initiator, 1 part by weight of 2,2-diethoxyacetophenone, 23 parts by weight of silica particles (average particle size 1.5 μm), and 1 part by weight of γ-glycidoxypropyltrimethoxysilane were uniformly mixed using three rolls. The mixture was sufficiently mixed until it became a liquid to obtain a curable resin composition.

A liquid crystal display device was produced using the obtained curable resin composition as a sealant for liquid crystal display elements.
That is, the sealing agent was applied to one of the two transparent substrates with transparent electrodes with a dispenser so as to draw a rectangular frame. Subsequently, fine droplets of liquid crystal (manufactured by Chisso Corporation, JC-5004LA) are dropped onto the entire surface of the transparent substrate frame, and the other transparent substrate is immediately overlaid. Irradiated for 60 seconds at an intensity of / cm ² . After that, liquid crystal annealing was performed at 120 ° C. for 1 hour for thermosetting to obtain a liquid crystal display device.

( Example 1 )
1000 parts by weight of a crystalline epoxy resin represented by the following general formula (4) (manufactured by Nippon Steel Chemical Co., Ltd .: YSLV-80DE, melting point 79 ° C.), 2 parts by weight of p-methoxyphenol as a polymerization inhibitor, and triethylamine as a reaction catalyst 2 parts by weight and 200 parts by weight of acrylic acid were reacted at 90 ° C. for 5 hours while feeding air, to obtain a crystalline (meth) acrylic acid-modified epoxy resin (50% partially acrylate).
The same as Reference Example 1 except that this crystalline (meth) acrylic acid-modified epoxy resin (50% partially acrylated) was used instead of the amorphous (meth) acrylic acid-modified epoxy resin (50% partially acrylated). A curable resin composition was prepared by the method, and a liquid crystal display device was produced using this as a sealant.

In the formula, G represents a glycidyl group.

(Comparative Example 1)
Curability comprising 35 parts by weight of urethane acrylate represented by the following general formula (5) (manufactured by Kyoeisha Chemical Co., AH-600), 15 parts by weight of 2-hydroxybutyl acrylate, 50 parts by weight of isobornyl acrylate, and 3 parts by weight of benzophenone. The resin composition was mixed so as to be a uniform liquid to obtain a photocurable sealing agent, and a liquid crystal display device was produced using this.

In the formula, R ¹ represents an alkyl chain having 5 carbon atoms.

(Comparative Example 2)
A curable resin composition comprising 50 parts by weight of a bisphenol A epoxy resin represented by the following general formula (6) (Epicoat 828US, manufactured by Japan Epoxy Resin Co., Ltd.) and 25 parts by weight of a hydrazide-based curing agent (manufactured by Nippon Hydrazine Kogyo Co., Ltd., NDH). The product was sufficiently mixed using a three roll so as to be a uniform liquid to obtain a sealant, and a liquid crystal display device was produced using this.

About the liquid crystal display devices produced in Reference Example 1 , Example 1 and Comparative Examples 1 and 2, color unevenness generated in the liquid crystal around the seal portion was visually observed before and after being left at 60 ° C. and 95% RH for 500 hours. Liquid crystal contamination was evaluated in four stages (no color unevenness at all), ○ (color unevenness slightly), Δ (color unevenness a little), and x (color unevenness considerably). Here, the number of samples was 5 per section.
The results are shown in Table 1.

( Reference Example 2 )
After thoroughly mixing the curable resin composition obtained in the same manner as in Reference Example 1 using three rolls so as to form a uniform liquid, the conductive fine particles are used with respect to 100 parts by weight of the curable resin composition. 2 parts by weight of gold-plated metal plating fine particles (manufactured by Sekisui Chemical Co., Ltd., Micropearl AU-206) were mixed and mixed with a vacuum planetary stirrer to prepare a vertical conduction material for a liquid crystal display element.

A liquid crystal display device was produced in the same manner as in Reference Example 1 except that a vertical conduction pattern was formed on a vertical conduction electrode on a transparent substrate by applying the obtained vertical conduction material to a transparent substrate.

When the obtained liquid crystal display device was visually observed for color unevenness occurring in the liquid crystal around the vertical conduction material before and after being left at 60 ° C., 95% RH for 500 hours, the evaluation result of ○ (the color unevenness is slight) Met. Also, the conductivity was good.

According to the present invention, when used as at least one of a liquid crystal display element and a sealing agent for liquid crystal display elements, a sealing agent for liquid crystal display elements, and a vertical conduction material for liquid crystal display elements in the production thereof, the component is contained in the liquid crystal material. Since there is little color unevenness in the liquid crystal display because it does not dissolve in the liquid crystal and cause liquid crystal contamination, a curable resin composition for a liquid crystal display element that is particularly suitable for manufacturing a liquid crystal display device by a dropping method, and a liquid crystal using the same A sealing agent for a display element, a sealing agent for a liquid crystal display element, a vertical conduction material for a liquid crystal display element, and a liquid crystal display device can be provided.

Claims (12)

A curable resin composition for a liquid crystal display element comprising a (meth) acrylic acid-modified epoxy resin obtained by reacting a crystalline epoxy resin and (meth) acrylic acid , wherein the crystalline epoxy resin is an ether type epoxy resin A curable resin composition for a liquid crystal display element. The curable resin composition for a liquid crystal display element according to claim 1, wherein the ether type epoxy resin is represented by the following general formula (4) .

In formula (4), G represents a glycidyl group. 3. The curable resin composition for a liquid crystal display device according to claim 1, wherein the crystalline epoxy resin has a melting point of 140 ° C. or lower. 4. The curable resin composition for a liquid crystal display element according to claim 1, wherein the (meth) acrylic acid-modified epoxy resin is a crystalline (meth) acrylic acid-modified epoxy resin. 5. The curable resin composition for a liquid crystal display element according to claim 1, wherein the (meth) acrylic acid-modified epoxy resin has a melting point of 80 ° C. or less. 6. The (meth) acrylic acid-modified epoxy resin has a total number of sulfur atoms and oxygen atoms in the resin skeleton of 5 to 10, for a liquid crystal display element according to claim 1, 2, 3, 4 or 5 Curable resin composition. (Meth) acrylic acid-modified epoxy resins, claim value obtained by dividing the total number of atoms of the total of sulfur and oxygen atoms in the resin skeleton, characterized in that a 0.08 to 0.14 1,2 The curable resin composition for a liquid crystal display element according to 3, 4, 5, or 6 . 8. The curable resin composition for a liquid crystal display device according to claim 1 , wherein the amount of the (meth) acrylic acid-modified epoxy resin is 10 to 50% by weight. . A sealing agent for a liquid crystal display element, comprising the curable resin composition for a liquid crystal display element according to claim 1, 2, 3, 4, 5, 6, 7 or 8 . A sealing agent for a liquid crystal display element comprising the curable resin composition for a liquid crystal display element according to claim 1, 2, 3, 4, 5, 6, 7 or 8 . A vertical conducting material for a liquid crystal display element comprising the curable resin composition for a liquid crystal display element according to claim 1, 2, 3, 4, 5, 6, 7, or 8 , and conductive fine particles. A sealing agent for a liquid crystal display element according to claim 9 , a sealing agent for a liquid crystal display element according to claim 10 , and a vertical conduction material for a liquid crystal display element according to claim 11 are used. Liquid crystal display device.