WO2009119688A1

WO2009119688A1 - Sealing material for liquid-crystal dropping process, vertical-conduction material, and liquid-crystal display element

Info

Publication number: WO2009119688A1
Application number: PCT/JP2009/056002
Authority: WO
Inventors: 尹一男; 山口真史; 西出勝則
Original assignee: 積水化学工業株式会社
Priority date: 2008-03-26
Filing date: 2009-03-25
Publication date: 2009-10-01
Also published as: CN101978313A; JP5584800B2; CN101978313B; JP2013257567A; KR20100138893A; TW200949392A; JP2013257568A; TWI474089B; JPWO2009119688A1; JP5584801B2; JP5508001B2; KR101579331B1

Abstract

A sealing material for the liquid-crystal dropping process is provided which has excellent applicability and high adhesion between the seal and a substrate and causes almost no liquid-crystal contamination. The sealing material is hence optimal for producing a liquid-crystal display element giving a liquid-crystal display reduced in color unevenness. Also provided are a vertical-conduction material and a liquid-crystal display element. The sealing material for the liquid-crystal dropping process comprises a (meth)acrylate compound having a structure represented by general formula (1). In formula (1), R¹ represents hydrogen or methyl; R² represents chemical formula (2-1) or (2-2); R³ represents a structure derived from an acid anhydride; R⁴ represents a structure derived from an epoxy compound; X represents a structure formed by the ring cleavage of a cyclic lactone; n is an integer of 2-5; and a is an integer of 1-4. In formula (2-2), b is an integer of 0-8, c is an integer of 0-3, d is an integer of 0-8, and e is an integer of 0-8, provided that any one of b, c, and d is 1 or larger.

Description

Liquid crystal dropping method sealing agent, vertical conduction material, and liquid crystal display element

The present invention is a liquid crystal that is excellent in coating properties, has high adhesion between a seal and a substrate, and hardly causes liquid crystal contamination, and is optimal for manufacturing a liquid crystal display element with little color unevenness in liquid crystal display. The present invention relates to a sealing agent for dripping method. Moreover, this invention relates to the vertical conduction material and liquid crystal display element which use this sealing compound for liquid crystal dropping methods.

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, it was produced by injecting liquid crystal into the cell from a liquid crystal injection port provided in a part thereof, and sealing the liquid crystal injection port with a sealing agent or a sealing agent.

In this method, first, a seal pattern provided with a liquid crystal injection port is formed on one of two transparent substrates with electrodes using a thermosetting sealant, and prebaked at 60 to 100 ° C. in the sealant. Dry the solvent. Next, the two substrates are placed facing each other with a spacer in between and bonded, 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, thermal distortion causes positional deviation, gap variation, decrease in adhesion between the sealing agent and the substrate, etc., residual solvent thermally expands, bubbles are generated, cap variation and seal path are There are problems such as generation of a seal, a long seal curing time, a complicated pre-baking process, a short usable time of the sealant due to volatilization of the solvent, and a long time for liquid crystal injection. 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, the manufacturing method of the liquid crystal display element called the dripping method using the sealing agent which consists of a photocurable thermosetting combined type resin composition is examined (for example, refer patent document 1). In the dropping method, first, a rectangular seal pattern is formed on one of the two transparent substrates with electrodes by screen printing. Next, a liquid crystal micro-droplet is applied to the entire surface of the transparent substrate in an uncured state with the sealant uncured, and the other transparent substrate is stacked under vacuum to return to normal pressure. To temporarily cure. Thereafter, heating is performed at the time of liquid crystal annealing to perform main curing, and a liquid crystal display element is manufactured. In this method, a liquid crystal display element can be manufactured with extremely high efficiency, and this dropping method is currently the mainstream of the manufacturing method of the liquid crystal display element.

The liquid crystal dropping method can significantly reduce the liquid crystal introduction process time compared to the vacuum injection method, while the sealant is in contact with the liquid crystal in an uncured state, so the components of the sealant are easily eluted into the liquid crystal. There was a problem of causing liquid crystal contamination.
As one of the methods for solving such a problem, there is a method of performing two-stage curing by ultraviolet rays and heating using a photocuring and thermosetting combined sealing agent. In this two-stage curing, a sealing agent is used. The higher the percentage of photocured is, the more the elution of the sealing agent component into the liquid crystal can be suppressed.
However, the photocuring / thermosetting sealant has a problem in that when it is photocured, stress is generated inside the cured product, so that the adhesiveness to the substrate is not sufficient.

On the other hand, Patent Document 2 describes that the adhesion between the sealing agent and the substrate is increased by adding a (meth) acrylate compound having a structure derived from a cyclic lactone to the sealing agent.
However, the sealing agent described in Patent Document 2 has a problem that the viscosity is very high, so that the coating property is inferior, and the sealing agent may break when applied to the substrate. .

JP 2001-133794 A JP 2007-41559 A

The present invention is a liquid crystal dropping method that is excellent in coating properties, has high adhesion between a seal and a substrate, and hardly causes liquid crystal contamination, and is optimal for manufacturing a liquid crystal display device with little color unevenness in a liquid crystal display. An object of the present invention is to provide a sealing agent. Moreover, an object of this invention is to provide the vertical conduction material and liquid crystal display element which use this sealing compound for liquid crystal dropping methods.

This invention is the sealing compound for liquid crystal dropping methods containing the (meth) acrylate compound which has a structure represented by following General formula (1).

In formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents the following chemical formula (2-1) or (2-2), R ³ represents a structure derived from an acid anhydride, R 2 ⁴ represents a structure derived from an epoxy compound, X represents a ring-opening structure of a cyclic lactone, n represents an integer of 2 to 5, and a represents an integer of 1 to 4.

In the formula (2-2), b represents an integer of 0 to 8, c represents an integer of 0 to 3, d represents an integer of 0 to 8, e represents an integer of 0 to 8, b, Any one of c and d is 1 or more.
The present invention is described in detail below.

The present inventors have so far proposed a sealing agent for liquid crystal display elements using a curable resin composition containing an acrylated epoxy resin as a suitable sealing agent particularly in the dropping method.
When such a curable resin composition is used, the sealing agent for liquid crystal display elements can be a combined type of photocuring and thermosetting, and the polarity of the contained resin is high, which is compatible with liquid crystals. Therefore, contamination of the liquid crystal can be effectively prevented. A (meth) acrylate compound having a structure derived from a cyclic lactone is further added to such a sealing agent for liquid crystal display elements, or a (meth) acrylate compound having a structure derived from a cyclic lactone instead of an acrylated epoxy resin. By using it, the adhesiveness between the sealing agent and the substrate could be increased (Patent Document 2).

As a result of intensive studies on the cause of the viscosity of the sealant for liquid crystal display elements described in Patent Document 2 being very high and poor in coating properties, the number of cyclic lactone ring-opening units in the (meth) acrylate compound Thus, it was found that the coating property of the obtained sealing agent for liquid crystal display elements can be adjusted. That is, in the sealing agent for liquid crystal display elements described in Patent Document 2, the number of cyclic lactone ring-opening units was 1, but the coating property was dramatically improved by setting this to 2-5. The present inventors have found that the present invention can be accomplished and have completed the present invention.

The sealing agent for liquid crystal dropping method of the present invention (hereinafter also simply referred to as the sealing agent of the present invention) contains a (meth) acrylate compound having a structure represented by the general formula (1). By containing such a (meth) acrylate compound, the sealing agent of the present invention has an appropriate viscosity and excellent coatability. And the outstanding effect that the adhesiveness of the seal | sticker after hardening and a board | substrate is high can be exhibited.
In the present specification, (meth) acrylate means acrylate or methacrylate.

In the general formula (1), X represents a ring-opening structure of a cyclic lactone. By having such a ring-opening structure of a cyclic lactone in the molecule, the (meth) acrylate compound having the structure represented by the general formula (1) can increase the adhesion between the sealing agent and the substrate.
The lower limit of n indicating the number of units of X is 2 and the upper limit is 5. When the n is less than 2, the molecular weight of the (meth) acrylate compound having the structure represented by the general formula (1) is too small, the number of OH groups per molecule increases, and the intermolecular hydrogen bond strength increases. Since it becomes strong, the viscosity of the resulting sealant becomes too high. When n exceeds 5, the OH group per molecule decreases and the intermolecular hydrogen bond strength becomes weak, so the viscosity becomes too low, the synthesis reaction becomes multistage, and the unreacted raw material is added to the target product. Since it remains, the liquid crystal may be contaminated when used as a sealant. A preferable upper limit of n is 4.

The cyclic lactone that forms the ring-opening structure of the cyclic lactone is not particularly limited. For example, γ-undecalactone, ε-caprolactone, γ-decalactone, σ-dodecalactone, γ-nonalactone, γ-heptalactone, Examples thereof include γ-valerolactone, σ-valerolactone, β-butyrolactone, γ-butyrolactone, β-propiolactone, σ-hexanolactone, 7-butyl-2-oxepanone and the like. These cyclic lactones may be used alone or in combination of two or more.
Among them, those having 5 to 7 carbon atoms in the straight chain portion of the main skeleton when the ring is opened are preferable.

In the (meth) acrylate compound having the structure represented by the general formula (1), R ² is represented by the chemical formula (2-2) in which b is 1 to 4, c is 0, and d is 0. Is preferred. By selecting such R ² , the resin becomes flexible and the effect of improving the adhesion between the sealing agent and the substrate can be obtained.

The (meth) acrylate compound having the structure represented by the general formula (1) is preferably a polyfunctional (meth) acrylate compound having a 2 or more, that is, 2 or more (meth) acryl groups. When the (meth) acrylate compound is a polyfunctional (meth) acrylate compound having two or more (meth) acryl groups, the cured product of the sealing agent of the present invention has excellent heat resistance due to an increase in crosslink density. , Become reliable. Especially, it is more preferable that said a is 2.

Although it does not specifically limit as a method of preparing the (meth) acrylate compound which has a structure represented by the said General formula (1), For example, carboxylic acid (C) obtained by reaction shown to following Reaction formula (3) and Examples include a method of reacting with an epoxy compound.

In the reaction formula (3), the (meth) acrylate (A) and the cyclic anhydride (B) are reacted to obtain the carboxylic acid (C).
In the (meth) acrylate ^(A), R 1, ^{R 2,} and X has a structure represented by the above general formula (1) (meth) in the acrylate compound ^R 1, ^{R 2,} and similar to the X Is.

The (meth) acrylate (A) can be obtained, for example, by a method in which a (meth) acrylic ester having a hydroxyl group such as 2-hydroxyethyl acrylate and a cyclic lactone are mixed and heated to react. it can.
Specific examples of the (meth) acrylate (A) include caprolactone-2- (meth) acryloyloxyethyl.

The cyclic anhydride in (B), R ³ is the same as the R ³ in having a structure represented by the general formula (1) (meth) acrylate compounds, cyclic acids such as the following specific examples The acid structure portion is removed from the anhydride.
Specific examples of the cyclic anhydride (B) include, for example, maleic anhydride, succinic anhydride, phthalic anhydride, citraconic anhydride, Ricacid TH, Ricacid HT-1, Ricacid HH, Ricacid HT-700, Ricacid MH, Ricacid MT-500, Ricacid HNA, Ricacid HNA-100, Ricacid OSA, Ricacid DDSA (all of which are manufactured by Shin Nippon Rika Co., Ltd.) and the like.

The (meth) acrylate compound having the structure represented by the general formula (1) can be obtained by reacting the obtained carboxylic acid (C) with an epoxy compound.
The epoxy compound may be a monofunctional epoxy compound, but is preferably a polyfunctional epoxy compound having two or more epoxy groups.

When the epoxy compound is a polyfunctional epoxy compound having two or more epoxy groups, the resulting (meth) acrylate compound having a structure represented by the general formula (1) is two or more (meth) acrylic compounds. It becomes a polyfunctional (meth) acrylate compound having a group. Specifically, a polyfunctional epoxy group having two or more (meth) acryl groups by reacting 1 mol of the polyfunctional epoxy with a carboxylic acid (C) having the number of moles corresponding to the number of epoxy groups of the polyfunctional epoxy. A (meth) acrylate compound is obtained. At this time, the number of (meth) acryl groups of the (meth) acrylate compound having the structure represented by the general formula (1) to be obtained is the same as the number of epoxy groups of the used polyfunctional epoxy.

Specific examples of the monofunctional epoxy compound include Licarresin L-100 (manufactured by Shin Nippon Rika Co., Ltd.), EPICLON 520, EPICLON 703 (all of which are manufactured by DIC), n-butyl glycidyl ether, glycidyl (meth) acrylate, Examples thereof include 4-hydroxybutyl acrylate glycidyl, and the number of carbon atoms constituting the main chain is preferably 10 or less.
Specific examples of the bifunctional epoxy compound among the polyfunctional epoxy compounds include, for example, bisphenol types such as EPICLON EXA-850CRP (made by DIC), hydrogenated bisphenol types such as EPICLON EXA-7015 (made by DIC), Examples thereof include ethylene glycol diglycidyl ether, and specific examples of the trifunctional or higher functional epoxy compound include EPICLON 725 (manufactured by DIC). Examples of the bisphenol type and hydrogenated bisphenol type include A type, E type, and F type.

R ⁴ in the (meth) acrylate compound having the structure represented by the general formula (1) produced by such a method becomes a structure derived from the epoxy compound, and when the epoxy compound is a polyfunctional epoxy, a is 2 or more.

The sealing agent of the present invention may contain other curable resins in addition to the (meth) acrylate compound having the structure represented by the general formula (1).
In that case, the preferable minimum of the compounding quantity of the (meth) acrylate compound which has a structure represented by the said General formula (1) in all the curable resin components to contain is 5 weight%, and a preferable upper limit is 80 weight%. . When the blending amount of the (meth) acrylate compound having the structure represented by the general formula (1) is less than 5% by weight, the residual stress of the cured sealant obtained cannot be sufficiently relaxed, and the produced liquid crystal The adhesion between the substrates of the display elements may be insufficient. When the blending amount of the (meth) acrylate compound having the structure represented by the general formula (1) exceeds 80% by weight, a cured product of the obtained sealing agent is used to disperse the residual stress. Although the adhesiveness between the substrates is enhanced, the workability such as the dispensing property of the obtained sealant may be extremely deteriorated. The more preferable lower limit of the blending amount of the (meth) acrylate compound having the structure represented by the general formula (1) is 10% by weight, and the more preferable upper limit is 50% by weight.

The other curable resin is not particularly limited, and examples thereof include those having a reactive functional group such as a (meth) acryloyl group, a cyclic ether such as an epoxy group or an oxetanyl group, and a styryl group. Specifically, for example, (meth) acrylic acid ester, partial epoxy (meth) acrylate resin, epoxy resin and the like are suitable.

Examples of the (meth) acrylic acid ester include an ester compound obtained by reacting a compound having a hydroxyl group with (meth) acrylic acid, and an epoxy obtained by reacting (meth) acrylic acid with an epoxy compound ( Examples thereof include urethane (meth) acrylates obtained by reacting (meth) acrylates and isocyanates with (meth) acrylic acid derivatives having a hydroxyl group.

The epoxy (meth) acrylate obtained by reacting the (meth) acrylic acid and the epoxy compound is not particularly limited. For example, an epoxy resin and (meth) acrylic acid are combined in the presence of a basic catalyst according to a conventional method. What is obtained by reacting with is mentioned.

Examples of the urethane (meth) acrylate obtained by reacting the above isocyanate with a (meth) acrylic acid derivative having a hydroxyl group include, for example, a (meth) acrylic acid derivative having a hydroxyl group with respect to 1 equivalent of a compound having two isocyanate groups. Two equivalents can be obtained by reacting in the presence of a catalytic amount of a tin-based compound.

Examples of the partial epoxy (meth) acrylate resin include a compound obtained by reacting a partial epoxy group of a compound having two or more epoxy groups with (meth) acrylic acid, or a hydroxyl group in a bifunctional or higher isocyanate. And a compound obtained by reacting a (meth) acrylic acid derivative having glycidol and then glycidol.

The epoxy resin is not particularly limited, and examples thereof include epichlorohydrin derivatives, cycloaliphatic epoxy resins, compounds obtained from the reaction of isocyanate and glycidol, and the like.

The other curable resin is preferably a compound having two or more reactive groups in one molecule in order to reduce the uncured residue at the time of curing as much as possible.
The other curable resin preferably has at least one hydrogen-bonding functional group in one molecule in order to further suppress the elution of the uncured sealing agent of the present invention into the liquid crystal.
The hydrogen bonding functional group is not particularly limited, and examples thereof include an —OH group, —SH group, —NHR group (R represents an aromatic or aliphatic hydrocarbon, and derivatives thereof), —COOH group , Functional groups such as —NHOH groups, and residues such as —NHCO—, —NH—, —CONHCO—, —NH—NH—, etc. present in the molecule. An OH group is preferred.

The sealing agent of the present invention preferably contains a photopolymerization initiator.
The photopolymerization initiator is not particularly limited, and for example, benzophenone compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin ether compounds, benzyl, thioxanthone, etc. are suitable. Can be used. These photoinitiators may be used independently and may use 2 or more types together.

Examples of commercially available photopolymerization initiators include Irgacure 907, Irgacure 819, Irgacure 651, Irgacure 369, Irgacure OXE01 (all of which are manufactured by Ciba Specialty Chemicals), Bensoin Methyl. Examples include ether, benzoin ethyl ether, benzoin isopropyl ether, Lucillin TPO (BASF Japan), KR-02 (Light Chemical).

Although content of the said photoinitiator is not specifically limited, A preferable minimum with respect to a total of 100 weight part of the (meth) acrylate compound and other curable resin which have a structure represented by General formula (1) mentioned above. Is 0.1 part by weight, and the preferred upper limit is 10 parts by weight. If the content of the photopolymerization initiator is less than 0.1 parts by weight, the ability to start photopolymerization may be insufficient and the above-described effects of the present invention may not be obtained. When content of the said photoinitiator exceeds 10 weight part, many unreacted radical polymerization initiators remain, and the weather resistance of the sealing agent of this invention may worsen. The minimum with more preferable content of the said photoinitiator is 1 weight part, and a more preferable upper limit is 5 weight part.

The sealing agent of the present invention preferably contains a polymerization inhibitor.
By containing the said polymerization inhibitor, it can suppress that gelatinization advances after carrying out the vacuum degassing of the sealing agent of this invention.

The polymerization inhibitor is not particularly limited. For example, 2,6-di-t-butylcresol, butylated hydroxyanisole, 2,6-di-t-butyl-4, ethylphenol, stearyl β- (3,5 -Di-t-butyl-4-hydroxyphenyl) propionate, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-6-t-butylphenol), 4,4′-thiobis-3-methyl-6-tert-butylphenol), 4,4-butylidenebis (3-methyl-6-tert-butylphenol), 3,9-bis [1,1-dimethyl-2- [ β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl] -2,4,8,10-tetraoxaspiro [5,5] undeca Tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, 1,3,5-tris (3 ′, 5′-di-t- Butyl-4'-hydroxybenzyl) -sec-triazine-2,4,6- (1H, 3H, 5H) trione, hydroquinone, p-methoxyphenol and the like.

The content of the polymerization inhibitor is not particularly limited, but the preferable lower limit is 50 ppm and the preferable upper limit is 2000 ppm with respect to the total amount of the sealing agent. If the content of the polymerization inhibitor is less than 50 ppm, gelation proceeds after the resulting sealant composition is degassed in vacuum, and it may be difficult to store and use. When content of the said polymerization inhibitor exceeds 2000 ppm, the photoreactivity of the sealing agent obtained may be suppressed and sclerosis | hardenability may not fully be obtained. The minimum with more preferable content of the said polymerization inhibitor is 70 ppm, and a more preferable upper limit is 1800 ppm.

When using together the curable resin which has an epoxy group in the sealing compound of this invention, it is preferable to contain a thermosetting agent.

Examples of the thermosetting 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-dihydroxymethyl Imidazole derivatives such as imidazole, modified aliphatic polyamines, tetrahydrophthalic anhydride, ethylene glycol Acid anhydrides such as-bis (anhydrotrimellitate), addition products such as the various amines and epoxy resins. These may be used alone or in combination of two or more. Especially, it is preferable to use a hydrazide compound, and it is more preferable to use malonic acid dihydrazide because it hardly causes liquid crystal contamination.

Although the compounding quantity of the said thermosetting agent is not specifically limited, A preferable minimum is 0 with respect to a total of 100 weight part of the (meth) acrylate compound which has a structure represented by the said General formula (1), and other curable resin. .1 part by weight, the preferred upper limit is 50 parts by weight. When the blending amount of the thermosetting agent is less than 0.1 parts by weight, the curable resin having an epoxy group may not be sufficiently cured. When the blending amount of the thermosetting agent exceeds 50 parts by weight, the moisture resistance of the cured product may be lowered. A more preferable lower limit of the amount of the thermosetting agent is 1 part by weight, and a more preferable upper limit is 20 parts by weight.

The sealing agent of the present invention may contain a silane coupling agent. The silane coupling agent mainly serves as an adhesion assistant that improves the adhesion between the sealing agent of the present invention and the substrate.
The silane coupling agent is not particularly limited, but is excellent in the effect of improving the adhesion to the substrate and can be prevented from flowing into the liquid crystal material by chemically bonding with the curable resin. Propyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-isocyanatopropyltrimethoxysilane and the like are preferably used. These silane coupling agents may be used alone or in combination of two or more.

The sealing agent of the present invention may contain a filler for the purpose of improving the adhesiveness due to the stress dispersion effect and improving the linear expansion coefficient. The filler is not particularly limited, for example, talc, asbestos, silica, diatomaceous earth, smectite, bentonite, calcium carbonate, magnesium carbonate, alumina, montmorillonite, diatomaceous earth, zinc oxide, iron oxide, magnesium oxide, tin oxide, titanium oxide, Inorganic fillers such as magnesium hydroxide, aluminum hydroxide, glass beads, silicon nitride, barium sulfate, gypsum, calcium silicate, talc, glass beads, sericite activated clay, bentonite, aluminum nitride, polyester fine particles, polyurethane fine particles, vinyl heavy Organic fillers such as coalesced fine particles and acrylic polymer fine particles can be mentioned.

The sealing agent of the present invention further comprises 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 as necessary. A curing accelerator such as 1,1-dimethylurea, an antifoaming agent, a leveling agent, and other additives may be contained.

The sealing agent of the present invention includes, for example, a three-roll, etc. (meth) acrylate compound having a structure represented by the above general formula (1), other curable resins and additives blended as necessary. It can be obtained by a method of mixing and uniformly dispersing by a conventionally known method using

The preferable lower limit of the viscosity when the sealing agent of the present invention is applied to the substrate by dispensing is 200,000 mPa · s, and the preferable upper limit is 400,000 mPa · s. If the viscosity is less than 200,000 mPa · s, the viscosity may be too low, and the applied sealing agent may be pushed by the liquid crystal and the shape may collapse. When the viscosity exceeds 400,000 mPa · s, the coating property is inferior, and the sealant may break when applied to the substrate.

Since the sealing agent of the present invention has an appropriate viscosity in the production of a liquid crystal display element, it has excellent coating properties and can be applied without disconnection. Further, since it has excellent adhesion to the substrate and hardly causes liquid crystal contamination, it can be suitably used for the production of a liquid crystal display element with little color unevenness in liquid crystal display.

A vertical conduction material can be produced by blending conductive fine particles with the liquid crystal dropping method sealing agent of the present invention. If such a vertical conduction material is used, the electrodes of the substrate can be reliably conductively connected.
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, for example, 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 substrate or the like due to the excellent elasticity of the resin fine particles.

The method for producing a liquid crystal display element using the sealing agent of the present invention and / or the vertical conduction material of the present invention is not particularly limited, and for example, it can be produced by a conventionally known method.
A liquid crystal display element using the sealing agent 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, a liquid crystal that is excellent in coating properties, has high adhesion between a seal and a substrate, and hardly causes liquid crystal contamination, so that it is optimal for manufacturing a liquid crystal display element with little color unevenness in liquid crystal display. It is possible to provide a sealing agent for dropping method, a vertical conduction material, and a liquid crystal display element.

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

(Synthesis of curable resin A)
To the reaction flask, 116 parts by weight of 2-hydrooxyethyl acrylate and 144 parts by weight of β-propiolactone were added, 0.3 part by weight of hydroquinone was added as a polymerization inhibitor, heated to 90 ° C. with a mantle heater, and stirred for 5 hours. To the stirred product, 148 parts by weight of phthalic anhydride was added and further stirred for 5 hours.
Subsequently, 170 parts by weight of bisphenol A diglycidyl ether was added, and the resulting mixture was stirred at 90 ° C. for 5 hours to obtain a curable resin A.

(Synthesis of curable resin B)
Into the reaction flask, 116 parts by weight of 2-hydrooxyethyl acrylate and 360 parts by weight of β-propiolactone were added, 0.3 part by weight of hydroquinone was added as a polymerization inhibitor, heated to 90 ° C. with a mantle heater, and stirred for 5 hours. To the stirred product, 148 parts by weight of phthalic anhydride was added and further stirred for 5 hours.
Subsequently, 170 parts by weight of bisphenol A diglycidyl ether was added and the resulting mixture was stirred at 90 ° C. for 5 hours to obtain a curable resin B.

(Synthesis of curable resin C)
To the reaction flask, 116 parts by weight of 2-hydrooxyethyl acrylate and 200 parts by weight of γ-valerolactone were added, 0.3 part by weight of hydroquinone was added as a polymerization inhibitor, heated to 90 ° C. with a mantle heater, and stirred for 5 hours. To the stirred product, 148 parts by weight of phthalic anhydride was added and further stirred for 5 hours.
Subsequently, 170 parts by weight of bisphenol A diglycidyl ether was added and the resulting mixture was stirred at 90 ° C. for 5 hours to obtain a curable resin C.

(Synthesis of curable resin D)
In a reaction flask, 116 parts by weight of 2-hydrooxyethyl acrylate and 500 parts by weight of γ-valerolactone were added, 0.3 part by weight of hydroquinone was added as a polymerization inhibitor, heated to 90 ° C. with a mantle heater, and stirred for 5 hours. To the stirred product, 148 parts by weight of phthalic anhydride was added and further stirred for 5 hours.
Subsequently, 170 parts by weight of bisphenol A diglycidyl ether was added and the resulting mixture was stirred at 90 ° C. for 5 hours to obtain a curable resin D.

(Synthesis of curable resin E)
Into the reaction flask, 116 parts by weight of 2-hydrooxyethyl acrylate and 114 parts by weight of ε-caprolactone were added, 0.3 part by weight of hydroquinone was added as a polymerization inhibitor, heated to 90 ° C. with a mantle heater, and stirred for 5 hours. To the stirred product, 148 parts by weight of phthalic anhydride was added and further stirred for 5 hours.
Subsequently, 170 parts by weight of bisphenol A diglycidyl ether was added and the resulting mixture was stirred at 90 ° C. for 5 hours to obtain a curable resin E.

(Synthesis of curable resin F)
In a reaction flask, 116 parts by weight of 2-hydrooxyethyl acrylate and 228 parts by weight of ε-caprolactone were added, 0.3 part by weight of hydroquinone was added as a polymerization inhibitor, heated to 90 ° C. with a mantle heater, and stirred for 5 hours. To the stirred product, 148 parts by weight of phthalic anhydride was added and further stirred for 5 hours.
Then, 170 weight part of bisphenol A diglycidyl ether was added, and the curable resin F was obtained by stirring at 90 degreeC for 5 hours.

(Synthesis of curable resin G)
In a reaction flask, 116 parts by weight of 2-hydrooxyethyl acrylate and 342 parts by weight of ε-caprolactone were added, 0.3 part by weight of hydroquinone was added as a polymerization inhibitor, heated to 90 ° C. with a mantle heater, and stirred for 5 hours. To the stirred product, 148 parts by weight of phthalic anhydride was added and further stirred for 5 hours.
Then, 170 weight part of bisphenol A diglycidyl ether was added, and the curable resin G was obtained by stirring at 90 degreeC for 5 hours.

(Synthesis of curable resin H)
Into the reaction flask, 116 parts by weight of 2-hydrooxyethyl acrylate and 456 parts by weight of ε-caprolactone were added, 0.3 part by weight of hydroquinone was added as a polymerization inhibitor, heated to 90 ° C. with a mantle heater, and stirred for 5 hours. To the stirred product, 148 parts by weight of phthalic anhydride was added and further stirred for 5 hours.
Subsequently, 170 parts by weight of bisphenol A diglycidyl ether was added and the resulting mixture was stirred at 90 ° C. for 5 hours to obtain a curable resin H.

(Synthesis of curable resin I)
In a reaction flask, 116 parts by weight of 2-hydrooxyethyl acrylate and 570 parts by weight of ε-caprolactone were added, 0.3 part by weight of hydroquinone was added as a polymerization inhibitor, heated to 90 ° C. with a mantle heater, and stirred for 5 hours. To the stirred product, 148 parts by weight of phthalic anhydride was added and further stirred for 5 hours.
Subsequently, 170 parts by weight of bisphenol A diglycidyl ether was added and the resulting mixture was stirred at 90 ° C. for 5 hours to obtain a curable resin I.

(Synthesis of curable resin J)
In a reaction flask, 116 parts by weight of 2-hydrooxyethyl acrylate and 684 parts by weight of ε-caprolactone were added, 0.3 part by weight of hydroquinone was added as a polymerization inhibitor, heated to 90 ° C. with a mantle heater, and stirred for 5 hours. To the stirred product, 148 parts by weight of phthalic anhydride was added and further stirred for 5 hours.
Then, 170 weight part of bisphenol A diglycidyl ether was added, and curable resin J was obtained by stirring at 90 degreeC for 5 hours.

(Synthesis of curable resin K)
Into the reaction flask, 116 parts by weight of 2-hydrooxyethyl acrylate and 256 parts by weight of γ-heptalactone were added, 0.3 part by weight of hydroquinone was added as a polymerization inhibitor, heated to 90 ° C. with a mantle heater, and stirred for 5 hours. To the stirred product, 148 parts by weight of phthalic anhydride was added and further stirred for 5 hours.
Then, 170 weight part of bisphenol A diglycidyl ether was added, and curable resin K was obtained by stirring at 90 degreeC for 5 hours.

(Synthesis of curable resin L)
Into the reaction flask, 116 parts by weight of 2-hydrooxyethyl acrylate and 640 parts by weight of γ-heptalactone were added, 0.3 part by weight of hydroquinone was added as a polymerization inhibitor, heated to 90 ° C. with a mantle heater, and stirred for 5 hours. To the stirred product, 148 parts by weight of phthalic anhydride was added and further stirred for 5 hours.
Then, 170 weight part of bisphenol A diglycidyl ether was added, and the curable resin L was obtained by stirring at 90 degreeC for 5 hours.

(Synthesis of curable resin M)
A reaction flask was charged with 72 parts by weight of acrylic acid and 312 parts by weight of bisphenol F diglycidyl ether, 0.3 part by weight of hydroquinone was added as a polymerization inhibitor, 0.3 part by weight of triethylamine was added as a reaction catalyst, and 90 ° C. with a mantle heater. And stirred for 5 hours to obtain a curable resin M (partial epoxy acrylate).

(Examples 1 to 15, Comparative Examples 1 to 7)
Examples 1 to 15 were prepared by stirring the raw materials in the blending amounts shown in Tables 1 to 3 with a planetary stirrer (“Shinky Co., Ltd.”, “Awatori Netaro”) and then uniformly mixing them with a three-roll ceramic roll. The sealing agents for the liquid crystal dropping method of Comparative Examples 1 to 7 were obtained. As raw materials in the table other than the curable resins A to M synthesized above, “KR-02” manufactured by Light Chemical Co., Ltd. is used as a photopolymerization initiator, and “EBECRYL 3700” manufactured by Daicel Cytec Co., Ltd. is used as a bisphenol A type epoxy acrylate resin. As the silane coupling agent, “KBM403” manufactured by Shin-Etsu Chemical Co., Ltd., “SO-C1” manufactured by Admatechs Corporation as the silica, and malonic acid dihydrazide or sebacic acid dihydrazide were used as the thermosetting agent.

(Evaluation)
The following evaluations were performed using the sealing agents obtained in Examples 1 to 15 and Comparative Examples 1 to 7. The results are shown in Tables 1-3.

(Measurement of viscosity of sealant)
0.5 g of each sealant was taken, put in an E-type viscometer (manufactured by BROOK FIELD, “DV-III”), and measured at 25 ° C. and a rotation speed of 1 rpm.

(Workability evaluation)
1 part by weight of spacer fine particles (manufactured by Sekisui Chemical Co., Ltd., “Micropearl SI-H050”, 5 μm) is dispersed in 100 parts by weight of each obtained sealing agent and filled into a syringe, and a centrifugal defoamer (Awatron AW- In 1), defoaming was performed, and a syringe discharge pressure of 200 kPa, a nozzle gap of 42 μm, a coating speed of 80 mm / sec, and a nozzle diameter of 0.4 mmφ were applied to one of two glass substrates with a dispenser. Subsequently, liquid droplets (manufactured by Chisso Co., Ltd., “JC-5004LA”) are applied dropwise onto the entire surface of the sealant frame of the glass substrate, and the other glass substrate is bonded together under vacuum, left for 10 minutes, and then sealed. A metal halide lamp was used for the agent part, and 100 mW / cm ² of ultraviolet rays were irradiated for 30 seconds to prepare 20 evaluation panels. In each evaluation panel, the number of defective panels due to disconnection and the number of defective panels due to liquid crystal leakage from the inside of the panel were counted and evaluated according to the following criteria.
◎: Number of defective panels 0: Number of defective panels 1 to 2 △: Number of defective panels 3 to 5 ×: Number of defective panels 5 or more

(Board adhesion evaluation)
As shown in FIG. 1, a sealant 2 obtained 30 mm inside from the end was dispensed on a glass substrate 1 (150 mm × 150 mm), and a glass substrate 3 (110 mm × 110 mm) was stacked and bonded together under vacuum. Ultraviolet rays (100 mW / cm ² , 3000 mJ) were irradiated, followed by heating at 120 ° C. for 1 hour to cure the sealant, thereby obtaining an adhesion test piece.
When the end of the substrate of the obtained adhesion test piece was pushed in at a speed of 5 mm / min using a metal rod 4 having a radius of 5 mm, the strength (Kgf) at which panel peeling occurred was measured. In addition, when the panel was not peeled even if it was pushed in until the substrate broke, it was expressed as “crack”.

(Liquid crystal panel evaluation (color unevenness evaluation))
1 part by weight of spacer fine particles (“Micropearl SI-H050”, 5 μm, manufactured by Sekisui Chemical Co., Ltd.) is dispersed in 100 parts by weight of each obtained sealing agent, filled into a syringe, and centrifuged with a centrifugal defoamer (Awatron AW- Defoaming was performed in 1), and applied to one of the two alignment films and the substrate with ITO with a dispenser at a discharge pressure of 100 to 400 kPa, a nozzle diameter of 0.4 mmφ, a nozzle gap of 42 μm, and a coating speed of 60 mm / sec.
Subsequently, fine droplets of liquid crystal (manufactured by Chisso Corporation, “JC-5004LA”) were dropped onto the entire surface of the sealing agent frame of the substrate with ITO, and the other substrate with ITO was bonded together under vacuum. At this time, the discharge pressure was adjusted for each sealing agent so that the line width of the sealing agent was about 1.5 mm. Immediately after bonding, the sealant portion was irradiated with 100 mW / cm ² of ultraviolet rays for 30 seconds using a metal halide lamp and temporarily cured. Next, main curing was performed by heating at 120 ° C. for 1 hour, and a liquid crystal display panel was produced.
About each obtained liquid crystal display panel, the liquid crystal orientation disorder in the sealant vicinity immediately after display panel preparation was confirmed visually. The alignment disorder was judged from the color unevenness of the display portion, and the evaluation was performed in the following four stages according to the degree of the color unevenness. The results are shown in Tables 1-3. Note that liquid crystal panels with evaluations of ◎ and ○ are at a level where there is no problem in practical use.
◎: No color unevenness ○: Color unevenness is slightly △: Color unevenness is slightly ×: Color unevenness is considerable

(Reference Examples 1 to 6)
Each raw material of the blending amounts shown in Table 4 was stirred with a planetary stirrer (“Shinky Co., Ltd.”, “Awatori Netaro”), and then mixed uniformly with three ceramic rolls to obtain the liquid crystals of Reference Examples 1-6. A sealant for the dripping method was obtained. As raw materials in the table other than the curable resin F and curable resin M synthesized above, “KR-02” manufactured by Light Chemical Co., Ltd. is used for the photopolymerization initiator, and Daicel Cytec Co., Ltd. is used for the bisphenol A type epoxy acrylate resin. “EBECRYL 3700”, “KBM403” manufactured by Shin-Etsu Chemical Co., Ltd. was used as the silane coupling agent, “SO-C1” manufactured by Admatechs was used as the silica, and malonic acid dihydrazide was used as the thermosetting agent.
In addition, the amount of residual hydroquinone in the obtained sealants of Reference Examples 1 to 6 was measured using liquid chromatography. The results are shown in Table 4. Reference Example 1 is the same sealant as Example 5.

(Evaluation)
The following evaluations were performed using the sealing agents obtained in Reference Examples 1 to 6.
The results are shown in Table 4.

(Evaluation of gelation)
The obtained sealant is put into a syringe and vacuum deaerated for 10 minutes under conditions of 1500 rpm and 3 torr with a vacuum deaerator (“ARV-200”, manufactured by Shinky Corporation). It was left for a week, a small amount was taken out with a spatula and applied to a glass substrate by hand, and it was examined whether or not gelling of the sealant had progressed. Evaluation was made as “◯” for those that did not gel and could be applied to the substrate, and “×” for those that gelled and could not be successfully applied to the substrate.

(Evaluation of light-shielding part curability)
As shown in FIG. 2, the board | substrate 5 which vapor-deposited the half surface of the Corning glass 0.7mmt and the board | substrate 6 which vapor-deposited the whole surface were prepared. Each sealing agent was applied in the form of dots on the boundary between the portions of the substrate 5 where the chromium was not deposited, and the substrates 6 were bonded together and then crushed sufficiently.
Next, after irradiating the bonded substrate with 100 mW / cm ² ultraviolet rays from the surface of the substrate 5 for 30 seconds, the substrates 5 and 6 are peeled off, washed with toluene, and the portion where the seal remains without being washed. This distance was measured using a microscope.

According to the present invention, the coating property is excellent, the adhesiveness between the seal and the substrate is high, and the liquid crystal is hardly contaminated. A sealing agent for a certain liquid crystal dropping method, a vertical conduction material, and a liquid crystal display element can be provided.

It is explanatory drawing which shows the evaluation method of board | substrate adhesiveness. It is explanatory drawing which shows the evaluation method of light-shielding part sclerosis | hardenability.

Claims

The sealing agent for liquid crystal dropping methods characterized by including the (meth) acrylate compound which has a structure represented by following General formula (1).

In the formula (1), R 1 represents a hydrogen atom or a methyl group, R 2 represents the following chemical formula (2-1) or (2-2), R 3 represents a structure derived from an acid anhydride, R 4 represents a structure derived from an epoxy compound, X represents a ring-opening structure of a cyclic lactone, n represents an integer of 2 to 5, and a represents an integer of 1 to 4.

In the formula (2-2), b represents an integer of 0 to 8, c represents an integer of 0 to 3, d represents an integer of 0 to 8, e represents an integer of 0 to 8, b, Any one of c and d is 1 or more.
2. The liquid crystal according to claim 1, wherein in the general formula (1), R 2 is represented by the chemical formula (2-2) wherein b is 1 to 4, c is 0, and d is 0. Sealing agent for dripping method.
3. The sealing agent for liquid crystal dropping method according to claim 1, wherein the (meth) acrylate compound having a structure represented by the general formula (1) has a of 2 to 4.
4. The liquid crystal according to claim 1, 2 or 3, wherein the content of the (meth) acrylate compound having a structure represented by the general formula (1) is 5 to 80% by weight of the entire curable resin component. Sealing agent for dripping method.
Furthermore, the sealing agent for liquid crystal dropping methods of Claim 1, 2, 3 or 4 characterized by containing the curable resin which has an epoxy group, and malonic acid dihydrazide.
6. The sealing agent for liquid crystal dropping method according to claim 1, further comprising 50 to 2000 ppm of a polymerization inhibitor based on the total amount of the sealing agent for liquid crystal dropping method.
A vertical conduction material comprising the sealing agent for a liquid crystal dropping method according to claim 1, 2, 3, 4, 5, or 6, and conductive fine particles.
A liquid crystal display element comprising the sealing agent for liquid crystal dropping method according to claim 1, 2, 3, 4, 5 or 6, and / or the vertical conduction material according to claim 7.