JP2007003911A - Sealing agent for liquid crystal instillation method, vertical conduction material, and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing agent for a liquid crystal instillation method, which when used in the manufacture of a liquid crystal display device by an instillation method, can produce a liquid crystal display device that is free of color uneveness, because there is no contaminant of the liquid crystal caused by the elution of the sealing agent component in the liquid crystal, and is thus particularly suitable for manufacturing a liquid crystal display device by instillation method, a vertical conduction material using the sealing agent for a liquid crystal instillation method, and to provide the liquid crystal display device. <P>SOLUTION: The sealing agent for a liquid crystal installation method contains a hardening resin and an optical radical polymerization initiator. Here, 60 mol% or higher of the hardening functional group, contained in the hardening resin, is (meth)acryloyl group. The optical radical polymerization initiator is a sealing agent for a liquid crystal instillation method, having three or more ring structures in the molecule. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

When the present invention is used for manufacturing a liquid crystal display element by a dropping method, the liquid crystal display element to be manufactured has little color unevenness because the sealing agent component does not contaminate the liquid crystal due to elution into the liquid crystal. The present invention relates to a sealing agent for a liquid crystal dropping method that is most suitable for manufacturing a liquid crystal display element by a dropping method, a vertical conduction material using the sealing agent for a liquid crystal dropping method, and a liquid crystal display element.

In recent years, electronic devices such as liquid crystal display elements, electronic components, and the like are required to have higher performance and higher quality.
Conventionally, a liquid crystal display element such as a liquid crystal display cell is formed by forming a cell by facing two transparent substrates with electrodes facing each other at a predetermined interval and sealing the periphery with a sealing agent. The liquid crystal was injected into the cell from the liquid crystal injection port, 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 the spacers sandwiched therebetween, and hot pressing is performed at 110 to 220 ° C. for 10 to 90 minutes to adjust the gap near the seal, 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, the positional displacement, gap variation, decrease in adhesion between the sealing agent and the substrate occur due to thermal strain, etc .; residual solvent thermally expands to generate bubbles, resulting in cap 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 dropping method using a sealing agent made of a curable resin composition has been studied (for example, see Patent Document 1). In the dropping method, first, a rectangular seal pattern is formed on one of two transparent substrates with electrodes by screen printing or the like. 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. Then, if necessary, it is heated at the time of liquid crystal annealing and further cured to produce a liquid crystal display element. 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 manufacturing methods for liquid crystal display devices, and a sealing agent for liquid crystal display elements that can be suitably used for the dripping method is desired.

Thus, when manufacturing a liquid crystal display element by the dropping method, the sealing agent is photocured and then thermally cured, but is used when (meth) acrylic polymerization is used when the sealing agent is photocured. As the photopolymerization initiator to be obtained, a radical photopolymerization initiator is generally used.

However, the radical photopolymerization initiator used in the conventional dripping method has higher volatility than other components of the sealant, and when a liquid crystal display element is manufactured by the dripping method, it diffuses into the liquid crystal and is liquid crystal. This is likely to cause a display defect of a liquid crystal display element that can be contaminated.

In order to solve such a problem, for example, a method using a high molecular weight photo radical polymerization initiator can be considered. However, a high-purity high-molecular-weight photoradical polymerization initiator has not been obtained, and therefore, in the production of a liquid crystal display element by a dropping method, it is possible to sufficiently prevent the occurrence of display defects due to the photoradical polymerization initiator. It was hard to say.
JP 2001-133794 A

In view of the above situation, the present invention, when used for manufacturing a liquid crystal display element by a dropping method, does not contaminate the liquid crystal because the sealing agent component is eluted in the liquid crystal. An object of the present invention is to provide a liquid crystal dropping method sealing agent that is less uneven and particularly optimal for manufacturing a liquid crystal display device by a dropping method, a vertical conduction material using the liquid crystal dropping method sealant, and a liquid crystal display element. To do.

The present invention is a sealing agent for a liquid crystal dropping method containing a curable resin and a radical photopolymerization initiator, wherein the curable resin contains 60 mol% or more of a curable functional group (meth) acryloyl group. And the radical photopolymerization initiator is a liquid crystal dropping method sealing agent having three or more ring structures in the molecule.
The present invention is described in detail below.

As a result of diligent study, the inventors of the present invention have disclosed a curable resin containing a predetermined amount of (meth) acryloyl group in one molecule as a sealant used for manufacturing a liquid crystal display element by a dropping method, and a specific structure. By using a combination with a photo radical polymerization initiator, the curability to light irradiation is sufficiently high, and contamination from the photo radical polymerization initiator into the liquid crystal of the liquid crystal display element produced by the dropping method is eliminated. The inventors have found that it can be suitably suppressed, and have completed the present invention.

The sealing agent for liquid crystal dropping method of the present invention (hereinafter also referred to as the sealing agent of the present invention) contains a curable resin.
The curable resin is a resin containing a curable functional group that is reactively cured by light and heat, and 60 mol% or more of the total curable functional group contained is a (meth) acryloyl group. If it is less than 60 mol%, the curability of the sealing agent of the present invention will be insufficient. A preferred lower limit is 75 mol%, and a preferred upper limit is 95 mol%. In the present specification, the (meth) acryloyl group means an acryloyl group or a methacryloyl group.
In addition, when 60 mol% or more of the total curable functional group is a (meth) acryloyl group, for example, when the curable resin is composed of a single resin, all of the curable resin is present in the curable resin. Means that 60 mol% or more of the curable functional group is a (meth) acryloyl group, while when the curable resin is composed of a plurality of resins, all of the curable functional groups present in the plurality of resins It means that 60 mol% or more of the total of curable functional groups is a (meth) acryloyl group.

The curable resin is not particularly limited as long as 60 mol% or more of the total curable functional group contained is a (meth) acryloyl group. For example, (meth) acrylic acid is reacted with a compound having a hydroxyl group. Ester compound obtained by reaction, epoxy (meth) acrylate obtained by reacting (meth) acrylic acid with an epoxy compound, urethane obtained by reacting isocyanate with a (meth) acrylic acid derivative having a hydroxyl group ) Acrylate, epoxy resin and the like.

The sealant of the present invention is used in the production of a liquid crystal display element by a dropping method, and since the uncured sealant is in direct contact with the liquid crystal, the liquid crystal is contaminated by the sealant and often causes a problem in display quality. Therefore, it is preferable that the curable resin having a (meth) acryloyl group constituting the sealant is incompatible with liquid crystal, and specifically, the epoxy (meth) acrylate or urethane (meth) acrylate is used. Preferably there is.

Moreover, the said epoxy (meth) acrylate can also use a commercial item, if 60 mol% or more of the total curable functional group to contain is a (meth) acryloyl group, for example, Eveacryl 3700, Evecryl 3600, Evekril 3701, Evecryl 3703, Evecril 3200, Evecril 3201, Evecril 3600, Evecril 3702, Evecril 3412, Evecril 860, Evecril RDX63182, Evecril 6040, Evecril 3800 (all manufactured by Daicel UCB), EA-1020, EA-10, EA-10 5520, EA-5323, EA-CHD, EMA-1020 (all made by Shin-Nakamura Chemical Co., Ltd.), epoxy ester M-600A, epoxy ester 40EM, epoxy ester 70PA, epoxy Siester 200PA, Epoxy ester 80MFA, Epoxy ester 3002M, Epoxy ester 3002A, Epoxy ester 1600A, Epoxy ester 3000M, Epoxy ester 3000A, Epoxy ester 200EA, Epoxy ester 400EA (all manufactured by Kyoeisha Chemical Co., Ltd.), Denacol acrylate DA-141, Denacol acrylate DA-314, Denacol acrylate DA-911 (all manufactured by Nagase ChemteX Corporation) and the like.
In addition to these, for example, a part of an epoxy compound modified with (meth) acrylic acid may be used as the epoxy (meth) acrylate.

Moreover, the said urethane (meth) acrylate can use a commercial item, if 60 mol% or more of the total curable functional group to contain is a (meth) acryloyl group, for example, M-1100, M-1200, M -1210, M-1600 (all manufactured by Toagosei Co., Ltd.), Evekril 230, Evekril 270, Evekril 4858, Evekril 8804, Evekrill 8803, Evekril 8807, Evekrill 9260, Evekrill 1290, Evekrill 5129, Evekril 4842 , Evekril 4827, Evekril 6700, Evekrill 220, Evekrill 2220 (all manufactured by Daicel UCB), Art Resin UN-9000H, Art Resin UN-9000A, Art Resin UN-7100 Art Resin UN-1255, Art Resin UN-330, Art Resin UN-3320HB, Art Resin UN-1200TPK, Art Resin SH-500B (all manufactured by Negami Kogyo Co., Ltd.), U-122P, U-108A, U-340P, U-4HA, U-6HA, U-324A, U-15HA, UA-5201P, UA-W2A, U-1084A, U-6LPA, U-2HA, U-2PHA, UA-4100, UA-7100, UA- 4200, UA-4400, UA-340P, U-3HA, UA-7200, U-2061BA, U-10H, U-122A, U-340A, U-108, U-6H, UA-4000 (all Shin-Nakamura Chemical Industry), AH-600, AT-600, UA-306H, AI-600, UA-101T, U -101I, UA-306T, etc. UA-306I and the like.

The epoxy resin is not particularly limited, and examples thereof include bisphenol A type epoxy resins such as Epicoat 828EL and Epicoat 1004 (all manufactured by Japan Epoxy Resin); Epicoat 806, Epicoat 4004 (all manufactured by Japan Epoxy Resin), and Epicron Bisphenol F type epoxy resin such as 830CRP (manufactured by Dainippon Ink Co., Ltd.); Bisphenol S type epoxy resin such as Epicron EXA1514 (manufactured by Dainippon Ink Co., Ltd.); 2,2′- such as RE-810NM (manufactured by Nippon Kayaku Co., Ltd.) Diallyl bisphenol A type epoxy resin; Hydrogenated bisphenol type epoxy resin such as Epicron EXA7015 (manufactured by Dainippon Ink &Co.); Propylene oxide-added bisphenol A type epoxy resin such as EP-4000S (manufactured by Asahi Denka); EX-201 ( Resorcinol type epoxy resin such as Gasechemtechs); Biphenyl type epoxy resin such as Epicoat YX-4000H (Japan Epoxy Resin); Sulfide type epoxy resin such as YSLV-50TE (manufactured by Tohto Kasei Co., Ltd.); YSLV-80DE Ether type epoxy resin such as Toto Kasei Co., Ltd .; Dicyclopentadiene type epoxy resin such as EP-4088S (Asahi Denka Co.); Naphthalene such as Epicron HP4032, Epicron EXA-4700 (both manufactured by Dainippon Ink and Co.) Type epoxy resin; phenol novolac type epoxy resin such as Epicron N-770 (manufactured by Dainippon Ink &Co.); orthocresol novolac type epoxy resin such as Epicron N-670-EXP-S (manufactured by Dainippon Ink &Co.); Epicron HP7200 ( Made by Dainippon Ink Dicyclopentadiene novolac type epoxy resin such as NC-3000P (manufactured by Nippon Kayaku Co., Ltd.), biphenyl novolac type epoxy resin such as ESN-165S (manufactured by Tohto Kasei Co., Ltd.), etc .; Naphthalene phenol novolac type epoxy resin such as ESN-165S; Glycidylamine type epoxy resins such as Epoxy Resin Co., Ltd., Epicron 430 (Dainippon Ink Co., Ltd.), TETRAD-X (Mitsubishi Gas Chemical Co., Ltd.), etc .; ZX-1542 (Toto Kasei Co., Ltd.) ), Epolite 80MFA (manufactured by Kyoeisha Chemical Co., Ltd.), Denacol EX-611 (manufactured by Nagase ChemteX Corporation), etc .; YR-450, YR-207 (both manufactured by Tohto Kasei Co., Ltd.), Epolide PB Rubber-modified epoxy such as (Daicel Chemical) Resins; Glycidyl ester compounds such as Denacol EX-147 (manufactured by Nagase ChemteX); Bisphenol A type episulfide resins such as Epicoat YL-7000 (manufactured by Japan Epoxy Resin); Other YDC-1312, YSLV-80XY, YSLV-90CR (All manufactured by Toto Kasei Co., Ltd.), XAC4151 (manufactured by Asahi Kasei Co., Ltd.), Epicoat 1031, Epicoat 1032 (all manufactured by Japan Epoxy Resin Co., Ltd.), EXA-7120 (manufactured by Dainippon Ink Co., Ltd.), TEPIC (manufactured by Nissan Chemical Co., Ltd.), etc. Is mentioned.

The blending amount of the epoxy resin is not particularly limited, and the epoxy (meth) acrylate or the like described above is such that 60 mol% or more of the total curable functional group contained in the curable resin becomes a (meth) acryloyl group. It adjusts suitably according to the kind, compounding quantity, etc. of curable resin which has a (meth) acryloyl group.

The sealing agent of the present invention contains a radical photopolymerization initiator having three or more ring structures in the molecule. Since such a radical photopolymerization initiator has a strong molecular structure, it is less volatile than the radical photopolymerization initiator conventionally used for the production of liquid crystal display elements by the dropping method, When a liquid crystal display element is produced by the dropping method using the sealant of the present invention, the photo radical polymerization initiator is difficult to diffuse into the sealant. In the present specification, the ring structure means a ring structure having 5 or more atoms such as a benzene ring, a cyclohexane ring, a morpholine ring and the like in the sealing agent of the present invention. The radical photopolymerization initiator has three or more of the above ring structures in one molecule.

The radical photopolymerization initiator having three or more ring structures in the molecule is not particularly limited, and examples thereof include 4-phenylbenzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, 2,2-bis- (2- Chlorophenyl) -4,5,4 ′, 5′-tetraphenyl-2′-H- (1,2 ′) biimidazole and the like.
Examples of commercially available products of these photo radical polymerization initiators include Irgacure 369, Irgacure 819, Irgacure TPO (all of which are manufactured by Ciba Specialty Chemicals), Speed Cure BCIM (manufactured by LAMBSON), and the like.

The said photoradical polymerization initiator has a preferable lower limit of the molar extinction coefficient at 400 nm measured in acetonitrile of 200 M ⁻¹ · cm ⁻¹ . When it is less than 200 M ⁻¹ · cm ⁻¹ , the curability of the curable resin is lowered, and when a liquid crystal display element is produced by a dropping method using the sealing agent of the present invention, a photo radical polymerization initiator is used. May diffuse into the liquid crystal.
Examples of the photo radical polymerization initiator having such a molar extinction coefficient include Irgacure 369, Irgacure 819, Irgacure TPO (all of which are manufactured by Ciba Specialty Chemicals).

In the sealing agent of the present invention, the content of the radical photopolymerization initiator is not particularly limited, but a preferred lower limit is 0.1 parts by weight and a preferred upper limit is 5 parts by weight with respect to 100 parts by weight of the curable resin. Part. When it is less than 0.1 part by weight, when a liquid crystal display element is produced by a dropping method using the sealant of the present invention, it cannot be sufficiently cured by irradiating light such as ultraviolet rays, and adheres to the substrate. In some cases, defects may occur in the properties, and uncured materials may elute into the liquid crystal. When the amount exceeds 5 parts by weight, an excessive radical photopolymerization initiator that does not participate in the reaction when the curable resin is photocured becomes too much, and the liquid crystal display element can be produced by the dropping method using the sealant of the present invention. When performed, the radical photopolymerization initiator may elute in the liquid crystal and contaminate the liquid crystal, which may cause display defects in the liquid crystal display element obtained. A more preferred lower limit is 0.3 parts by weight, and a more preferred upper limit is 3 parts by weight.

The sealing agent of the present invention may further contain a thermosetting agent, a filler, a silane coupling agent and the like.
The thermosetting agent is for reacting and crosslinking unsaturated double bonds and epoxy groups in the curable resin by heating, and plays a role of improving the adhesiveness and moisture resistance of the cured product after curing. Have. Although it does not specifically limit as said thermosetting agent, When manufacturing a liquid crystal display element by the dripping method using the sealing agent of this invention, since it hardens at 100-120 degreeC curing temperature, it is an amine excellent in low temperature reactivity. And / or containing a thiol group.

Examples of the thermosetting agent containing the amine and / or thiol group include organic acid dihydrazide compounds such as 1,3-bis [hydrazinocarbonoethyl-5-isopropylhydantoin] and adipic acid dihydrazide; 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-hydroxymethyl Imidazole, 2-imidazoline-2-thiol, 2-2'-thiodiethanethiol, various amines Addition products such as the epoxy resin. These may be used alone or in combination of two or more.

Although it does not specifically limit as desirable content of these thermosetting agents, A preferable minimum is 1 weight part and a preferable upper limit is 8 weight part with respect to 100 weight part of said hydrophilic curable resins. When the amount is less than 1 part by weight, the sealant of the present invention may not be provided with sufficient thermosetting property. When the amount exceeds 8 parts by weight, a liquid crystal display element is produced by the dropping method using the sealant of the present invention. At this time, the unreacted thermosetting agent may be eluted into the liquid crystal phase or may affect physical properties such as moisture resistance reliability.

The filler has roles such as improvement of adhesiveness due to stress dispersion effect, improvement of linear expansion coefficient, and the like.
The filler is not particularly limited. For example, silica, diatomaceous earth, alumina, zinc oxide, iron oxide, magnesium oxide, tin oxide, titanium oxide, magnesium hydroxide, aluminum hydroxide, magnesium carbonate, barium sulfate, gypsum, calcium silicate , Talc, glass beads, sericite activated clay, bentonite, aluminum nitride, silicon nitride, and other inorganic fillers.
The minimum with a preferable particle diameter of the said filler is 0.5 micrometer, and a preferable upper limit is 1.5 micrometers.

When the sealing agent of this invention contains the said filler, as a compounding quantity, a preferable minimum is 4 weight part with respect to 100 weight part of said curable resins, and a preferable upper limit is 40 weight part.

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

As said silane coupling agent, what has at least 1 functional group shown by A group in the following general formula and at least 1 functional group shown by the following B group is suitable.

Specifically, examples of the silane coupling agent include γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-isocyanatopropyltrimethoxysilane. Can be mentioned. These silane compounds may be used alone or in combination of two or more.

By using it as a silane coupling agent having such a structure, the sealing agent of the present invention can improve adhesion to a substrate or the like.

The sealing agent of the present invention further includes a reactive diluent for adjusting the viscosity, a thixotropic agent for adjusting the thixotropy, a spacer such as a polymer bead for adjusting the panel gap, and 3-p-chlorophenyl. A curing accelerator such as -1,1-dimethylurea, an antifoaming agent, a leveling agent, a polymerization inhibitor, and other additives may be contained.

The sealing agent of the present invention has a preferred lower limit of viscosity of 200 Pa · s and a preferred upper limit of 400 Pa · s when measured at 1.0 rpm at 25 ° C. using an E-type viscometer. When it is less than 200 Pa · s, when a liquid crystal display element is produced by the dropping method using the sealing agent of the present invention, stringing may occur during coating, or the seal width may be uneven, and 400 Pa -If it exceeds s, workability is remarkably inferior or coating with a dispenser becomes difficult.

In the sealing agent of the present invention, the volume resistivity of the cured body is preferably 10 ⁷ Ω · cm or more. If it is less than 10 ⁷ Ω · cm, the insulating property of the sealing agent of the present invention after curing deteriorates, and the liquid crystal display device produced using the sealing agent of the present invention may be short-circuited.

It does not specifically limit as a method of manufacturing the sealing agent of this invention, The said hardening resin and radical photopolymerization initiator, and predetermined amounts, such as said thermosetting agent, a filler, and a silane coupling agent mix | blended as needed And the like by a conventionally known method. At this time, in order to remove the ionic impurities contained, it may be brought into contact with an ion-adsorbing solid.

The sealing agent of the present invention has a strong molecular structure in which the radical photopolymerization initiator contained has three or more ring structures in the molecule, and has low volatility. Therefore, the sealing agent of the present invention is used. When a liquid crystal display element is produced by the dropping method, the photo radical polymerization initiator is difficult to diffuse into the liquid crystal, and the photo radical polymerization initiator diffuses into the liquid crystal and can suitably prevent liquid crystal contamination. It is possible to suitably prevent display defects due to the photo radical polymerization initiator from occurring in the liquid crystal display element.

In addition, when a liquid crystal display element is manufactured by the dropping method using the sealing agent of the present invention, the sealing pattern of the sealing agent of the present invention formed on the substrate is directly irradiated with light such as ultraviolet rays having a size of 50 μm square or more. There may be an unirradiated portion that is not irradiated. This ultraviolet non-irradiated part is derived from the structure of the liquid crystal display element. For example, the black matrix of the color filter substrate, the metal wiring, the transistor, and the like are overlapped with the seal pattern. When a sealing agent used for manufacturing a liquid crystal display element by a conventional dropping method has such an ultraviolet non-irradiated portion, the ultraviolet non-irradiated portion can be sufficiently photocured when irradiated with light such as ultraviolet rays. The components of the uncured sealing agent were eluted into the liquid crystal, causing liquid crystal contamination. However, in the sealing agent of the present invention, 60 mol% or more of the curable functional group contained in the curable resin is a (meth) acryloyl group, and the curing rate is high. In particular, the photo radical polymerization initiator is in acetonitrile. When the lower limit of the measured molar extinction coefficient at 400 nm is 200 M ⁻¹ · cm ⁻¹ , the sealing agent of the present invention has very excellent reactivity with light such as ultraviolet rays. Therefore, the sealing agent of the present invention can sufficiently cure the entire seal pattern including the ultraviolet non-irradiated part even when the ultraviolet non-irradiated part exists in the seal pattern, and the liquid crystal contamination Generation | occurrence | production can be prevented suitably.

Moreover, a vertical conduction material can be manufactured by mix | blending electroconductive fine particles with the sealing compound for liquid crystal dropping methods of this invention. If such a vertical conduction material is used, the electrodes of the transparent substrate can be conductively connected even in the case of a fine pattern.
The vertical conduction material containing the sealing agent for liquid crystal dropping method of the present invention and conductive fine particles is also one aspect of the present invention.

The conductive fine particles are not particularly limited, and metal balls, those obtained by forming a conductive metal layer on the surface of resin fine particles, and the like can be used. Among them, the one in which the conductive metal layer is formed on the surface of the resin fine particles is preferable because the conductive connection is possible without damaging the transparent substrate due to the excellent elasticity of the resin fine particles.

The liquid crystal display element using the sealing compound for liquid crystal dropping method of the present invention and / or the vertical conduction material of the present invention is also one aspect of the present invention.

According to the present invention, when used for manufacturing a liquid crystal display element by a dropping method, the liquid crystal is not contaminated by the sealing agent component being eluted into the liquid crystal. In particular, it is possible to provide a liquid crystal dropping method sealant that is particularly suitable for the production of a liquid crystal display element by a dropping method, a vertical conduction material using the liquid crystal dropping method sealant, and a liquid crystal display element.

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

Example 1
(Synthesis of epoxy acrylate)
0.1 g of triphenylphosphine was added to a solution obtained by dissolving 120 g of EX-201 (resorcinol type epoxy resin, manufactured by Nagase Chemtech) in 500 mL of toluene to obtain a uniform solution. To this solution, 70 g of acrylic acid was added dropwise over 2 hours with stirring under reflux, followed by further stirring under reflux for 8 hours.
Next, by removing toluene, an epoxy acrylate (EX-201 modified product: viscosity 60 Pa) in which all epoxy groups were converted to acryloyl groups was obtained.

(Preparation of sealant)
70 parts by weight of the obtained epoxy acrylate, 30 parts by weight of bisphenol F type epoxy resin (Epiclon 830CRP, manufactured by Dainippon Ink and Chemicals), photo radical polymerization initiator having a structure represented by the following chemical formula (1) (Irgacure TPO, Ciba Specialty) Tea Chemicals) 1 part by weight, thermosetting agent (Amicure VDH-J, Ajinomoto Fine Techno Co., Ltd.) 15 parts, glycidyl group-containing silane coupling agent (KBM403, Shin-Etsu Chemical Co., Ltd.) 0.5 parts by weight, and By mixing 30 parts by weight of a filler (SO-C1, manufactured by Admatechs) using a planetary stirrer (Awatori Nertaro, manufactured by Shinky Co., Ltd.), and further mixing using three rolls, A sealant for a liquid crystal dropping method was obtained.

When the ratio of the acryloyl group in the curable functional group contained in the curable resin of the obtained liquid crystal dropping method sealing agent was calculated, 67 mol% was an acryloyl group.

(Example 2)
The formulation for preparing the sealant was 85 parts by weight of epoxy acrylate, 15 parts by weight of bisphenol F type epoxy resin (Epicron 830CRP, manufactured by Dainippon Ink), photo radical polymerization initiator (Irgacure TPO, manufactured by Ciba Specialty Chemicals) ) 1 part by weight, thermosetting agent (Amicure VDH-J, Ajinomoto Fine Techno Co., Ltd.) 7 parts by weight, glycidyl group-containing silane coupling agent (KBM403, Shin-Etsu Chemical Co., Ltd.) 0.5 part by weight, and filler ( A sealing agent for liquid crystal dropping method was obtained in the same manner as in Example 1 except that 30 parts by weight (SO-C1, manufactured by Admatechs) was used.

When the ratio of the acryloyl group in the curable functional group contained in the curable resin of the obtained liquid crystal dropping method sealing agent was calculated, 83 mol% was an acryloyl group.

(Example 3)
The formulation for preparing the sealant was 100 parts by weight of epoxy acrylate, 1 part by weight of radical photopolymerization initiator (Irgacure TPO, manufactured by Ciba Specialty Chemicals), glycidyl group-containing silane coupling agent (KBM403, manufactured by Shin-Etsu Chemical) ) A sealant for a liquid crystal dropping method was obtained in the same manner as in Example 1 except that 0.5 part by weight and 30 parts by weight of a filler (SO-C1, manufactured by Admatex) were used.

The ratio of the acryloyl group in the curable functional group contained in the curable resin of the obtained sealing agent for liquid crystal dropping method was 100 mol%.

Example 4
The compound used for preparing the sealing agent was 85 parts by weight of epoxy acrylate, 15 parts by weight of bisphenol F type epoxy resin (Epiclon 830CRP, manufactured by Dainippon Ink and Chemicals), and photoradical polymerization initiation having a structure represented by the following chemical formula (2) 1 part by weight of agent (Speed Cure BCIM, manufactured by LAMBSON), 7 parts by weight of thermosetting agent (Amicure VDH-J, manufactured by Ajinomoto Fine Techno Co.), silane coupling agent containing glycidyl group (KBM403, manufactured by Shin-Etsu Chemical Co.) A sealant for a liquid crystal dropping method was obtained in the same manner as in Example 1 except that 5 parts by weight and 30 parts by weight of a filler (SO-C1, manufactured by Admatechs) were used.

When the ratio of the acryloyl group in the curable functional group contained in the curable resin of the obtained liquid crystal dropping method sealing agent was calculated, 83 mol% was an acryloyl group.

(Comparative Example 1)
The compound used for preparing the sealing agent was 85 parts by weight of epoxy acrylate, 15 parts by weight of bisphenol F type epoxy resin (Epicron 830CRP, manufactured by Dainippon Ink and Chemicals), and photoradical polymerization initiation having a structure represented by the following chemical formula (3) 1 part by weight of agent (Irgacure 184, manufactured by Ciba Specialty Chemicals), 7 parts by weight of thermosetting agent (Amicure VDH-J, manufactured by Ajinomoto Fine Techno), glycidyl group-containing silane coupling agent (KBM403, manufactured by Shin-Etsu Chemical) A sealing agent for a liquid crystal dropping method was obtained in the same manner as in Example 1 except that 0.5 part by weight and 30 parts by weight of a filler (SO-C1, manufactured by Admatex) were used.

When the ratio of the acryloyl group in the curable functional group contained in the curable resin of the obtained liquid crystal dropping method sealing agent was calculated, 83 mol% was an acryloyl group.

(Comparative Example 2)
The compound used for preparing the sealing agent was 85 parts by weight of epoxy acrylate, 15 parts by weight of bisphenol F type epoxy resin (Epicron 830CRP, manufactured by Dainippon Ink and Chemicals), and photo radical polymerization having a structure represented by the following chemical formula (4) 1 part by weight of agent (KR-02, manufactured by Light Chemical Co., Ltd.), 7 parts by weight of thermosetting agent (Amicure VDH-J, manufactured by Ajinomoto Fine Techno Co., Ltd.), silane coupling agent containing glycidyl group (KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) 0 A sealing agent for a liquid crystal dropping method was obtained in the same manner as in Example 1 except that 0.5 part by weight and 30 parts by weight of a filler (SO-C1, manufactured by Admatex) were used.

When the ratio of the acryloyl group in the curable functional group contained in the curable resin of the obtained liquid crystal dropping method sealing agent was calculated, 83 mol% was an acryloyl group.

(Comparative Example 3)
The formulation for preparing the sealant was 85 parts by weight of epoxy acrylate, 15 parts by weight of bisphenol F type epoxy resin (Epiclon 830CRP, manufactured by Dainippon Ink), photo radical polymerization initiator (KR-02, manufactured by Light Chemical Company) 3 parts by weight, 7 parts by weight of a thermosetting agent (Amicure VDH-J, manufactured by Ajinomoto Fine Techno Co., Ltd.), 0.5 parts by weight of a glycidyl group-containing silane coupling agent (KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.), and a filler (SO -C1, manufactured by Admatechs Co., Ltd.) A liquid crystal dropping method sealing agent was obtained in the same manner as in Example 1 except that the amount was 30 parts by weight.

When the ratio of the acryloyl group in the curable functional group contained in the curable resin of the obtained liquid crystal dropping method sealing agent was calculated, 83 mol% was an acryloyl group.

(Comparative Example 4)
The formulation for preparing the sealant was 40 parts by weight of epoxy acrylate, 60 parts by weight of bisphenol F type epoxy resin (Epicron 830CRP, manufactured by Dainippon Ink), photo radical polymerization initiator (Irgacure TPO, manufactured by Ciba Specialty Chemicals) ) 1 part by weight, thermosetting agent (Amicure VDH-J, Ajinomoto Fine Techno Co., Ltd.) 30 parts by weight, glycidyl group-containing silane coupling agent (KBM403, Shin-Etsu Chemical Co., Ltd.) 0.5 part by weight, and filler ( A sealing agent for liquid crystal dropping method was obtained in the same manner as in Example 1 except that 30 parts by weight (SO-C1, manufactured by Admatechs) was used.

When the ratio of the acryloyl group in the curable functional group contained in the curable resin of the obtained liquid crystal dropping method sealing agent was calculated, 36 mol% was an acryloyl group.

(Evaluation)
About the sealing agent for liquid crystal dropping methods produced in Examples 1-4 and Comparative Examples 1-4, it evaluated by the following method.

Each of the obtained liquid crystal dropping method sealing agents was applied to a black matrix (BM) and a substrate with a transparent electrode with a dispenser so as to draw a rectangular frame. Subsequently, fine droplets of liquid crystal (manufactured by Chisso Corp .; JC-5004LA) were dropped onto the entire surface of the transparent substrate frame, and another substrate with a transparent electrode (without BM) was immediately placed on top of the substrate with BM. The seal part was irradiated with ultraviolet rays at 50 mW / cm ² for 20 seconds using a high-pressure mercury lamp. At this time, the line width of the squeezed sealant was about 1.2 mm, and 0.1 mm was drawn so as to overlap with BM.
Thereafter, liquid crystal annealing was performed at 120 ° C. for 1 hour, and at the same time, the sealant was thermally cured to obtain a liquid crystal display element.
Separately, a liquid crystal display element in which a sealant was arranged outside so as not to overlap with the BM even after being crushed was also produced in the same manner.

Each 0.3 g of the obtained liquid crystal dropping method sealant was weighed into a sample tube (No. 2) and allowed to stand on the bottom surface of the sample tube until the sealant was flattened. UV irradiation of 2000 mJ / cm ² was performed on each of the top and bottom surfaces.
Thereafter, 0.5 g of liquid crystal (manufactured by Chisso Corp .; JC-5004LA) was put in, covered, and heated at 120 ° C. for 1 hour to prepare a diffused liquid confirmation sample.

(Panel display unevenness evaluation)
About the obtained liquid crystal display element according to each example and comparative example, the color unevenness generated in the liquid crystal around the seal portion after standing for 200 hours in an environment of 80 ° C. was visually observed and evaluated according to the following criteria. The results are shown in Table 1.
◎: No color unevenness ○: Little color unevenness △: Some color unevenness ×: There is considerable color unevenness

(Confirmation of eluate in liquid crystal)
Liquid crystals were taken out from the liquid crystal eluate confirmation samples according to the respective Examples and Comparative Examples, and the eluate of the sealant component into the liquid crystals was confirmed using the GC / MS method. The results are shown in Table 1.

According to the present invention, when used for manufacturing a liquid crystal display element by a dropping method, the liquid crystal is not contaminated by the sealing agent component being eluted into the liquid crystal. In particular, it is possible to provide a liquid crystal dropping method sealant that is particularly suitable for the production of a liquid crystal display element by a dropping method, a vertical conduction material using the liquid crystal dropping method sealant, and a liquid crystal display element.

Claims (4)

A liquid crystal dropping method sealing agent containing a curable resin and a radical photopolymerization initiator,
60 mol% or more of the curable functional group contained in the curable resin is a (meth) acryloyl group, and
The said radical photopolymerization initiator has 3 or more ring structures in a molecule | numerator, The sealing compound for liquid crystal dropping methods characterized by the above-mentioned. 2. The sealing agent for liquid crystal dropping method according to claim 1, wherein the radical photopolymerization initiator has a molar extinction coefficient at 400 nm measured in acetonitrile of 200 M ⁻¹ · cm ⁻¹ or more. A vertical conduction material comprising the sealing agent for liquid crystal dropping method according to claim 1 or 2 and conductive fine particles. A liquid crystal display element comprising the sealing agent for liquid crystal dropping method according to claim 1 or 2 and / or the vertical conduction material according to claim 3.