KR100980546B1 - Sealing material for liquid crystals and process for production of liquid crystal panels with the same - Google Patents

Abstract

The present invention provides a liquid crystal sealing agent that is excellent in adhesion reliability after being left for a long time under adhesiveness and high temperature, high humidity, electro-optical properties of liquid crystals, orientation retention of liquid crystals, and viscosity stability when applied to a liquid crystal panel substrate. Specifically, the present invention is a modified epoxy resin obtained by reacting an epoxy resin with an ester compound represented by the formula (1), wherein the amount of the ester compound in the reaction is less than 1 mole with respect to 1 mole of the epoxy group of the epoxy resin. It relates to a liquid crystal sealing agent comprising a.

Formula 1

(Formula 1,

R ₁ is a hydrogen atom or a methyl group

R ₂ is a hydrogen atom, an alkyl group, an alkenyl group, a halogen atom, a nitro group or a methoxy group

X is a single bond, an alkylene group, a group represented by Formula A or Formula B)

A

Formula B

(In Formula A and Formula B, R ₃ is an alkylene group.)

Description

Liquid crystal sealing agent and manufacturing method of liquid crystal panel using the same {SEALING MATERIAL FOR LIQUID CRYSTALS AND PROCESS FOR PRODUCTION OF LIQUID CRYSTAL PANELS WITH THE SAME}

The present invention relates to a liquid crystal sealing agent and a method for producing a liquid crystal panel using the same.

Currently liquid crystal panel

1) Applying a main sealing agent on a glass substrate to form a liquid crystal injection hole having a liquid crystal injection hole, and bonding to another pair of glass substrate to heat-cure the main sealing agent to produce a panel, 2) the above After inject | pouring a liquid crystal into the liquid crystal injection hole of a panel, it manufactures by the method of sealing a liquid crystal injection part with an ultraviolet curable end sealing agent.

However, the method of manufacturing the liquid crystal panel has a problem of a long process time for injecting liquid crystals, a decrease in adhesion of glass substrates due to thermal deformation due to high temperature around 150 ° C. during thermosetting, positional deviation, and gap deviation between glass substrates. And liquid crystal molecules ooze out from the sealing agent.

In order to solve this problem, 1) a photocurable resin is applied on a liquid crystal panel substrate to form a frame for filling a liquid crystal, 2) a liquid crystal is dropped in the frame, and 3) an additional pair of liquid crystal panels. The manufacturing method of the liquid crystal panel by the liquid crystal dropping method which joins a board | substrate is proposed (patent document 1 etc.). As resin (liquid crystal sealing agent) which forms the frame for filling the liquid crystal used for this method, photocurable acrylic adhesive (patent document 1) which has acrylic ester or methacrylic acid ester as a main component, photocurable epoxy adhesive, and acrylic resin A mixed system (Patent Document 2), a photocuring and thermosetting combination type resin (Patent Document 3) containing, as a main component, a partial acrylate or partial methacrylate of an epoxy resin is proposed. Since these photocurable sealing agents can be hardened at room temperature for a short time by light irradiation, the problem of the panel making method in the case of using the said thermosetting resin, such as shortening of time used for panel manufacture, position shift, etc. is solved.

However, when a photocurable acrylic adhesive (Patent Document 1) mainly composed of an acrylic acid ester or a methacrylic acid ester (patent document 1) or a mixed system of a photocurable epoxy adhesive and an acrylic resin (Patent Document 2) is used as a liquid crystal sealing agent, the adhesiveness is insufficient. Moreover, moisture resistance reliability, such as the adhesive reliability after leaving for a long time under high temperature, high humidity, the electro-optical characteristic of a liquid crystal, the orientation retention property of a liquid crystal, is insufficient.

On the other hand, when resin which has the partial acrylate or partial methacrylate of an epoxy resin as a main component is used as a liquid-crystal sealing agent (patent document 3), adhesiveness and the said moisture resistance reliability are improved. However, the viscosity stability of the liquid crystal sealing agent is unstable, and the viscosity increases in the process of forming a frame by applying it to a substrate of the liquid crystal panel, resulting in a thinner line width, or increasing the number of times the sealing agent is replaced in the dispenser. There is a problem in properties, and a decrease in yield is a problem.

Further, Patent Document 4 discloses a quaternary amine as a partial acrylate or partial methacrylate of an epoxy resin, in which the epoxy resin and the ester compound are molar ratios of 0.5 to 2: 1 in the epoxy group of the epoxy resin and the ester group of the ester compound. The modified epoxy resin obtained by making it react as a catalyst is disclosed, and the meaning which can use this resin also as a sealing agent for display is disclosed.

Patent Document 1: Japanese Patent No. 284642

Patent Document 2: Japanese Patent Application Laid-Open No. 2001-83531

Patent Document 3: Japanese Patent No. 3583326

Patent Document 4: Japanese Patent Application Laid-Open No. 1987-207241

Disclosure of Invention

Problems to be Solved by the Invention

As a result of earnestly examining, the inventor discovered that the hydroxyl group formed when (meth) acrylating an epoxy resin has made the viscosity stability of a liquid crystal sealing agent unstable. Further, a resin obtained by reacting an epoxy resin and an ester compound disclosed as an example in Patent Document 4 under conditions in which the epoxy group of the epoxy resin and the ester group of the ester compound are in a molar ratio of 1: 1 is selected from a hydrogen derived from an epoxy group. Since it contained little roxyl group, it turned out that adhesiveness as a liquid crystal sealing agent is not enough. In addition, in resins having a low polar group concentration such as the above resins, interaction with generally hydrophobic liquid crystal molecules is increased, which may damage the electro-optical properties of the liquid crystal, and so on. Reached.

That is, the objective of this invention is excellent in the moisture resistance reliability, such as adhesive reliability, the electro-optical characteristic of a liquid crystal, the orientation retention of a liquid crystal, etc. after being left for a long time under adhesiveness and high temperature, high humidity, and also excellent in the viscosity stability at the time of coating a board | substrate of a liquid crystal panel. It is to provide a liquid crystal sealing agent.

Means to solve the problem

MEANS TO SOLVE THE PROBLEM The present inventors earnestly examined, and solved the said subject by using resin which makes the epoxy resin and the specific ester compound react on the conditions which an epoxy group exists excessively as a liquid crystal sealing agent. That is, the said subject is solved by the liquid crystal sealing agent which concerns on the following this invention.

[1] A modified epoxy resin obtained by reacting an epoxy resin with an ester compound represented by Chemical Formula 1,

Liquid crystal sealing agent containing the modified epoxy resin whose quantity of the said ester compound in the said reaction is less than 1 mol with respect to 1 mol of epoxy groups of the said epoxy resin.

(Formula 1,

R ₁ is a hydrogen atom or a methyl group

R ₂ is a hydrogen atom, an alkyl group, an alkenyl group, a halogen atom, a nitro group or a methoxy group

X is a single bond, an alkylene group, a group represented by Formula A or Formula B)

(In Formula A and Formula B, R ₃ is an alkylene group.)

[2] The liquid crystal sealing agent of [1], wherein the amount of the ester compound in the reaction is 0.3 mol to 0.7 mol with respect to 1 mol of the epoxy group of the epoxy resin.

(3) (a) 80-20 mass% of resin as described in said [1], (b) (meth) acrylic acid ester monomer or 10-40 mass% of these oligomers, (c) 10-40 mass% of epoxy resin, and ( About 100 mass parts of total of a), (b), (c)

(d) Liquid crystal sealing agent containing 0.1-7 mass parts of photoinitiators, (e) 3-20 mass parts of latent epoxy resin hardening | curing agents, and (f) 10-40 mass parts of fillers.

[4] (g) The liquid crystal sealing agent according to [3], further comprising 0.5 to 1.5 parts by mass of spacer particles.

[5] The liquid crystal sealing agent according to [3] to [4], wherein the viscosity at 25 ° C. with the E-type viscometer is from 100 to 450 Pa · s.

[6] A sealing agent for liquid crystal dropping method, comprising the resin according to any one of the above [1] to [5].

Moreover, the said subject is solved by the manufacturing method of the liquid crystal panel which concerns on the following this invention.

[7] applying a sealing agent to the first substrate to form a desired frame shape; Dropwise supplying liquid crystal into the frame-shaped frame; Stacking a second substrate opposite the first substrate; It has a process of hardening the said sealing agent with light,

The said sealing agent is a manufacturing method of the liquid crystal panel containing the photocurable resin composition of [1].

[8] The method for producing a liquid crystal panel according to [7], further comprising a step of curing the sealing agent by heat.

Effects of the Invention

INDUSTRIAL APPLICABILITY According to the present invention, a liquid crystal sealing agent excellent in adhesiveness and moisture resistance and excellent in viscosity stability when applied to a liquid crystal panel substrate can be provided.

Best Mode for Carrying Out the Invention

1. About liquid crystal sealing agent

A liquid crystal sealing agent bonds two board | substrates at regular intervals, and is a sealing agent for sealing the adhesive agent for bonding two board | substrates or a liquid crystal in the liquid crystal display in which the liquid crystal was enclosed in the space. )

(a) Modified Epoxy Resin

The liquid crystal sealing agent of the present invention includes a resin (modified epoxy resin) obtained by reacting an epoxy resin with an ester compound represented by the following formula (1).

Formula 1

(Formula 1,

R ₁ is a hydrogen atom or a methyl group

R ₂ is a hydrogen atom, an alkyl group, an alkenyl group, a halogen atom, a nitro group or a methoxy group

X is a single bond, an alkylene group, a group represented by formula A or formula B)

A

Formula B

(In Formula A and Formula B, R ₃ is an alkylene group.)

R <_1> is a hydrogen atom or a methyl group, and since a glass potential temperature (Tg) of a modified epoxy resin becomes high, it is preferable that it is a methyl group.

R <_2> is a hydrogen atom, an alkyl group, an alkenyl group, a halogen atom, a nitro group, or a methoxy group, and is couple | bonded with the ortho position, meta position, or para position of a phenoxy group. If the steric hindrance of R ₂ is small, the reactivity of the ester compound and the epoxy resin is excellent. Therefore, R ₂ is preferably a hydrogen atom or an alkyl having 1 to 3 carbon atoms, and more preferably a hydrogen atom in view of the availability of raw materials. desirable. Further, since R ₂ is the excellent reactivity with the smoking it is the electron withdrawing epoxy resin, R ₂ is a nitro group, chloro group, or may methoxy group. Moreover, if R <_2> is a polymeric functional group, since it is excellent in performance, such as heat resistance of hardened | cured epoxy resin, R <_2> may be an alkenyl group.

X is a group represented by a single bond (the structure in which the carbon of the carboxyl group and the oxygen of the phenoxy group are directly bonded), the general formula (A) or the general formula (B). As mentioned above, since the one with less steric hindrance is excellent in the reactivity of an ester compound and an epoxy resin, it is preferable that it is a single bond.

R ₃ is an alkylene group, and for this reason, an alkylene group having 1 to 3 carbon atoms is preferable.

These compounds can be obtained by a known method. For example, an ester compound having a structure in which X is a single bond can be obtained by reacting acrylic acid with phenol or a derivative thereof. The ester compound of the structure in which X is represented by the formula (A) is obtained by, for example, reacting acrylic acid with phenoxy alkyl alcohol or a derivative thereof. The ester compound of the structure in which X is represented by the formula (B) can be obtained by reacting phenol or a derivative thereof with a compound obtained by reacting acrylic acid with hydroxycarboxylic acid or a derivative thereof.

In the above, although the case where R <_1> and R <_2> is a hydrogen atom was demonstrated for the sake of simplicity, the case of the said group other than a hydrogen atom is also the same.

An epoxy resin means the compound which has one or more epoxy groups in a molecule | numerator. Although the epoxy resin used for manufacture of the said modified epoxy resin is not specifically limited, The following are included as an example.

Polyalkylene glycols, such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, and polypropylene glycol Aliphatic polyhydric glycidyl ether compounds obtained by the reaction of polyhydric alcohols represented by colloids, dimethylol propane, trimethylol propane, spiroglycol, glycerine and the like with epichlorohydrin .

Aromatic diols represented by bisphenol A, bisphenol S, bisphenol F, bisphenol AD, and the like, and diols obtained by modifying them with ethylene glycol, propylene glycol, alkylene glycol, and epichlorohydrin. Aromatic polyvalent glycidyl ether compounds.

Aromatic dicarboxylic acid and epi represented by aliphatic polyhydric glycidyl ester compound obtained by reaction of aliphatic dicarboxylic acid represented by adipic acid, itaconic acid, etc. with epichlorohydrin, isophthalic acid, terephthalic acid, pyromellitic acid, etc. Aromatic polyvalent glycidyl ester compound obtained by reaction with chlorohydrin, aliphatic polyvalent glycidyl ether compound obtained by reaction of hydroxydicarboxylic acid compound and epichlorohydrin or aromatic polyvalent glycidyl ether compound .

Aliphatic polyhydric glycidyl ether compound, Aliphatic polyhydric glycidyl amine compound obtained by reaction of aliphatic diamine represented by polyethylenediamine, and epichlorohydrin, diamino diphenylmethane, aniline, metaxylene Aromatic polyhydric glycidylamine compound obtained by reaction of aromatic diamine represented by diamine and epichlorohydrin, hydantoin and its derivatives and hydantoin type polyhydric article obtained by reaction of epichlorohydrin Lycidyl compound.

Polyphenols and epichloros represented by novolak-type polyhydric glycidyl ether compounds obtained by reaction of novolac resin derived from phenol or cresol and formaldehyde with epichlorohydrin, polyalkenylphenol or copolymers thereof, and the like Epoxidized diene polymers, such as a polyhydric glycidyl ether compound obtained by reaction with hydrin, epoxidized polybutadiene, and epoxidized polyisoprene, 3,4-epoxy-6-methylcyclohexylmethyl-3,4 Epoxy-6-methylcyclohexane carbonate, bis (2,3-epoxycyclopentyl) ether and the like.

Among them, glycidyl ether compounds obtained from epichlorohydrin, aromatic diols represented by bisphenol A, bisphenol S, bisphenol F, bisphenol AD, etc., diaminodiphenylmethane, aniline, The aromatic polyvalent glycidylamine compound obtained by reaction of the aromatic diamine and epichlorohydrin represented by metaxylenediamine etc. is preferable. Especially, the bifunctional epoxy resin which has two epoxy groups in one molecule, the trifunctional epoxy resin which has three, or the tetrafunctional epoxy resin which has four is preferable.

The molecular weight of the epoxy resin used for producing the modified epoxy resin of the present invention is 500 to 5000 in GPC (polystyrene equivalent), and the softening point temperature (temperature at which the endothermic value of the endothermic curve becomes maximum) by DSC is 40 to 180 ° C. desirable. These epoxy resins are preferably highly purified by molecular distillation in order to prevent impurities such as chloride ions from adversely affecting liquid crystal molecules and the like.

The modified epoxy resin of the present invention can be obtained by reacting at least one epoxy resin selected from these and at least one ester compound by a known method (see Japanese Patent Laid-Open No. 1987-207241). Specifically, it reacts by heating using a tertiary amine, quaternary onium salt (ammonium salt, phosphonium salt), and crown ethers as a catalyst. Especially, it is preferable to use the quaternary onium salt which reaction advances more effectively, and a quaternary ammonium salt is more preferable at the point which is easy to obtain.

Moreover, in order to prevent superposition | polymerization of an alkenyl group in the said reaction, you may add a polymerization inhibitor. Examples of the polymerization inhibitor include hydroquinone, hydroxy monomethyl ether, benzoquinone and the like.

In this reaction, a resin having a structure in which an ester group is added (esterified) to an epoxy group of an epoxy resin as a raw material is obtained. At this time, it is preferable that the molar ratio of the epoxy group and the ester group is less than 1 mole (the epoxy group is excessive) with respect to 1 mole of the epoxy group so that all the epoxy groups are not esterified. It is because it is excellent in viscosity stability, adhesiveness, etc. at the time of using as a liquid crystal sealing agent as mentioned above. In order to make these characteristics more excellent, it is preferable that it is 0.3-0.7 mol (0.3 or more and 0.7 mol or less) with respect to 1 mol of epoxy groups, and it is more preferable that it is 0.4-0.6 mol.

The ester group here is an ester group which is excellent in reactivity with an epoxy group. In other words, the compound represented by the formula (1) refers to a phenoxy ester group. However, when two ester groups exist in the formula (1), such as the ester compound represented by the formula (B), X refers to a highly reactive phenoxy ester group.

The modified epoxy resin obtained by the above reaction is assumed to be a mixture including a molecule having an epoxy group and an ester group in one molecule, a molecule having only an epoxy group in one molecule, and a molecule having only an ester group in one molecule. Although these mixing ratios are not limited, It is preferable that the ratio of the epoxy group and ester group which exist in the whole resin becomes the ratio after the epoxy group and ester group which used as a raw material reacted substantially equimolar. That is, the ratio of the epoxy group and the ester group in the modified epoxy resin obtained by reacting the difunctional epoxy resin and the ester compound in an epoxy group of the epoxy resin in an amount such that the ester group of the compound is 2: 1 (molar ratio) is about 1. It is preferable that it is 1 :.

(b) About (meth) acrylic acid ester monomers or oligomers thereof

 The liquid crystal sealing agent of this invention may contain (meth) acrylic acid ester monomer or these oligomers other than a modified epoxy resin.

A well-known thing can be used for the (meth) acrylic acid ester monomer used for this invention, The following are included as an example of these.

As substituents methyl, ethyl, propyl, butyl, amyl, 2-ethylhexyl, octyl, nonyl, dodecyl, hexadecyl, octadecyl, cyclohexyl, benzyl, methoxyethyl, butoxyethyl, phenoxyethyl, nonylphenoxy Ethyl, tetrahydrofurfuryl, glycidyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-chloro-2-hydroxypropyl, dimethylaminoethyl, diethylaminoethyl, nonylphenoxyethyltetrahydroper Monofunctional (meth) acrylates having groups such as furyl, caprolactone-modified tetrahydroperfuryl, isobornyl, dicyclopentanyl, dicyclopentenyl, dicyclopentenyloxyethyl and the like.

1,3-butylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neo Pentyl glycol, 1,8-octanediol, 1,9-nonanediol, tricyclodecanedimethanol, ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol 4 mole or more of ethylene oxide or propylene oxide was added to 1 mole of di (meth) acrylate, di (meth) acrylate of tris (2-hydroxyethyl) isocyanurate, and neopentyl glycol. 3 moles or more of ethylene to 1 mole of di (meth) acrylate and trimethylolpropane obtained by adding 2 moles of ethylene oxide or propylene oxide to 1 mole of di (meth) acrylate of diol and bisphenol A Diols of triols obtained by addition of oxides or propylene oxides, or Di (meth) acrylate / tris (2-hydroxyethyl) isocyanurate tri (meth) of diol obtained by adding 4 moles or more of ethylene oxide or propylene oxide to 1 mole of tri (meth) acrylate and bisphenol A ) Acrylic acid, trimethylol propane tri (meth) acrylate, poly (meth) acrylate / caprolactone modified tris of pentaerythritol tri (meth) acrylate / dipentaerythritol [(meth) acryloxyethyl] Isocyanurate, poly (meth) acrylate of alkyl-modified dipentaerythritol, poly (meth) acrylate / hydroxypivalate neopentylglycol di (meth) acrylate of caprolactone-modified dipentaerythritol, Caprolactone Modified Hydroxypivalic Acid Neopentylglycol Di (meth) acrylate / Ethylene Oxide Modified Phosphoric Acid (meth) acrylate Agent, ethylene oxide-modified alkylated phosphoric acid, such as polyfunctional (meth) acrylate (meth) acrylate.

N-vinyl-2-pyrrolidone, acryloyl morpholine, vinylimidazole, N-vinyl caprolactam, vinyl acetate, (meth) acrylic acid, (meth) acrylamide, N-hydroxymethylacrylamide or N- Hydroxyethyl acrylamide and alkyl ether compounds thereof.

As an example of the oligomer of the (meth) acrylic acid ester used for this invention, polyester poly (meth) acrylate, polyether poly (meth) acrylate, polyether ester polyurethane (meth) acrylate, and epoxy poly (meth) ) Acrylates are included. Although the said monomer and oligomer may be used independently, you may use it together.

(c) About epoxy resin

The liquid crystal sealing agent of this invention may contain the epoxy resin other than a modified epoxy resin, a (meth) acrylic acid ester monomer, or an oligomer thereof. What was already described can be used as said epoxy resin. Especially, since it is excellent in affinity with a modified epoxy resin, it is preferable to set it as resin of the same structure as the raw material of a modified epoxy resin.

When the compounding ratio of the said a component, the b component, and the c component (henceforth, resin which consists of these is called "mixed resin") makes the sum total 100 mass%, a component is 80-20 mass%, and b component is It is preferable that 10-40 mass% and c component become 10-40 mass%. It is because it is excellent in curability, viscosity stability, adhesiveness, and moisture resistance reliability.

(d) About the Photopolymerization Initiator

 The liquid crystal sealing agent of this invention may contain the photoinitiator. A photoinitiator is a substance which receives active light and produces active species, such as a radical. A photoinitiator is not specifically limited, It is possible to use a well-known material, For example, benzophenone, 2, 2- diethoxy acetophenone, benzyl, benzoyl isopropyl ether, benzyl dimethyl ketal, 1-hydroxy cyclohexylphenyl Ketones, thioxanthones, and the like.

It is preferable that a photoinitiator is 0.1-7 mass parts with respect to 100 mass parts of said mixed resins. It is because it is excellent in the hardenability by light irradiation and the moisture absorption resistance of hardened | cured material.

(e) About latent epoxy curing agents

 The liquid crystal sealing agent of this invention may contain the latent epoxy hardening | curing agent. The latent epoxy curing agent refers to a curing agent that does not react with the epoxy resin in the state of preserving the resin (room temperature, visible light, etc.) even when mixed with the epoxy resin, but exhibits reaction activity with the epoxy group by heat or light. . Known materials can be used as the latent epoxy curing agent, and examples thereof include organic acid dihydrazide compounds, imidazoles and derivatives thereof, dicyandiamide, aromatic amines, and polyhydric phenol curing agents, and especially organic acid dihydrazide compounds. The use of is preferred. It is preferable that the addition amount of these hardening | curing agents is 3-20 mass parts with respect to 100 mass parts of said mixed resins. This is because the viscosity stability and adhesion reliability under high temperature and high humidity are excellent.

(f) About filler

 The liquid crystal sealing agent of this invention may contain the filler. The filler may be a known material, but examples thereof include inorganic fillers and organic fillers for the purpose of adjusting viscosity, reducing the thermal stress of the cured product, and the like. The inorganic filler can be selected from known inorganic compounds, and examples thereof include calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum silicate, zirconium silicate, iron oxide, titanium oxide, aluminum oxide (alumina), zinc oxide, silicon dioxide, titanium Potassium acid, kaolin, talc, asbestos powder, quartz powder, mica, glass fibers and the like.

The organic filler can be selected from known organic compounds, and examples thereof include polymer particles obtained by copolymerizing polymethyl methacrylate, polystyrene and monomers copolymerizable with these. The particle diameter of the filler is not particularly limited as long as it is a range that does not affect the conduction characteristics, but is preferably 2 μm or less.

It is preferable that the addition amount of these fillers is 10-40 mass parts with respect to 100 mass parts of said mixed resins. It is because a thermal stress reduction effect can be acquired, without causing the fall of workability accompanying a viscosity increase.

(g) About spacer particles

 The liquid crystal sealing agent of this invention may contain the spacer particle. Spacer particle means the particle added to a liquid crystal sealing agent, in order to provide the space | interval between the board | substrates of a liquid crystal panel. The spacer particles are usually composed of glass, silica, polymer, or the like, and the shape is a spherical shape or a cylindrical shape. Although the particle diameter is suitably prepared by the space | interval between the board | substrates of a liquid crystal panel, it is usually 3-7 micrometers. The addition amount of the said particle | grain is 0.5-1.5 mass parts with respect to 100 mass parts of said mixed resins. Although the method of mixing the said particle | grains is not specifically limited, What is necessary is just to add simultaneously when adding the filler of said (f).

In addition to each component mentioned above, this invention can use additives, such as a thermosetting catalyst, a coupling agent, an ion trap agent, and an ion exchange agent, as needed. In particular, since the thermosetting reaction can be promoted, it is preferable to add a thermosetting catalyst.

The thermosetting catalyst which can be used for this invention means the substance which accelerates | stimulates a thermosetting reaction, A well-known thing can be used. Especially, it is preferable to activate at 70 degreeC or more from a viewpoint of viscosity stability at the time of operation | work, etc. Examples of these include amines and adducts thereof, such as imidazole and derivatives thereof. It is preferable that the addition amount of these curing catalysts is 0.1-20 mass% in a liquid crystal sealing agent. It is because hardening is accelerated | stimulated by making addition amount into 0.1 mass% or more, and viscosity stability can be ensured by setting it as 20 mass% or less.

When the liquid crystal sealing agent of this invention is set as the structure containing said (a)-(f) (it also contains (g) as needed), the viscosity in 25 degreeC by an E-type viscosity meter is 100-450 Pa. It is preferable that it is s, More preferably, it is 200-400 Pa.s. It is because workability | operativity at the time of apply | coating a liquid crystal sealing agent on the board | substrate of a liquid crystal panel is excellent. E-type viscometer is a cone plate type rotary viscometer.

It is preferable that the liquid crystal sealing agent of this invention is mixed uniformly, for example, after dry blending with a Henschel mixer, it can melt-knead and adjust sufficiently using three rolls. In kneading with three rolls, it is preferable that the roll temperature is set to 25 to 30 ° C. in order to knead uniformly without gelling. The kneaded liquid crystal sealing agent is preferably defoamed so that no bubbles remain.

In addition, you may use the liquid crystal sealing agent of this invention as a sealing agent for liquid crystal dropping methods. With the liquid crystal dropping method,

1) Process of apply | coating curable resin on a 1st board | substrate, and forming the frame for filling a liquid crystal.

2) dropping liquid crystal into the frame

3) further bonding the paired second substrate and curing the cured resin

By the method of manufacturing a liquid crystal panel.

Therefore, the sealing agent for liquid crystal dropping methods means curable resin used for the said method. The sealing agent for liquid crystal dropping methods can be adjusted by the method mentioned above.

2. Manufacturing Method of Liquid Crystal Panel

A liquid crystal panel can be manufactured by using the liquid crystal sealing agent of this invention. Although a liquid crystal panel can be manufactured arbitrarily in the range which does not impair the effect of this invention, a preferable manufacturing method is demonstrated below.

Liquid crystal panel,

1) applying a sealing agent to the first substrate to form a desired frame shape,

2) dropwise supplying liquid crystal into the frame of the frame shape;

3) overlapping the second substrate facing each other with the first substrate;

4) step of curing the sealing agent by light

It is manufactured through.

In the process of 1), a liquid crystal sealing agent is apply | coated on a 1st board | substrate using a dispenser, and a desired frame shape is formed. A board | substrate is a member which forms the basis of a display panel, and is normally comprised from two pieces of glass etc. The liquid crystal sealing agent may contain the spacer particle for providing the gap between the said glass.

In the process of 2), the liquid crystal material corresponded to the panel internal capacity after bonding is dripped precisely in the frame. Next, in the process of 3), the 2nd board | substrate which opposes a 1st board | substrate overlaps each other.

In the process of 4), 1000-6000 mJ amount of ultraviolet-rays of a 340-430 nm wavelength are irradiated, pressurizing the said board | substrate, photocuring a liquid crystal sealing agent, bonding a glass substrate, and producing a liquid crystal panel.

Moreover, after that, it heats at a temperature of 120 degreeC for 1 hour, without pressurization, and thermosets a liquid crystal sealing agent, and can also manufacture a liquid crystal panel.

Hereinafter, the present invention will be described by way of representative examples, but the present invention is not limited by these examples.

 Synthesis Example 1: Synthesis of Modified Epoxy Resin

Bisphenol A type epoxy resin: Epiclone EXA850CRP (epoxy equivalent 190 g / eq manufactured by Nippon Ink Chemical Co., Ltd.) 346 g (epoxy group) in a 500 ml four-necked flask equipped with a stirrer, a gas introduction tube, a thermometer, and a cooling tube. 1.82 mol), 162 g of phenyl methacrylate (162 g / eq of ester group equivalent) (1.0 mol of ester group), 16 g of tetrabutylammonium bromide, and 0.1 g of hydroquinone monomethyl ether were added. Subsequently, the mixture was heated and stirred at 120 ° C. for 8 hours while bubbling with dry air, followed by reaction to obtain a modified epoxy resin (partially phenyl methacrylated epoxy resin). The obtained resin was washed with ultrapure water.

Synthesis Example 2 Synthesis of Partially Methacrylated Epoxy Resin

In a 500 ml four-necked flask equipped with a stirrer, a gas introduction tube, a thermometer, and a cooling tube, 200 g of bisphenol A epoxy resin: Epiclone EXA850CRP (manufactured by Nippon Ink Chemical Co., Ltd.), 80 g of methacrylic acid, and 0.2 g of triethanolamine Committed. Thereafter, the mixture was heated and stirred at 110 ° C. for 5 hours while bubbling with dry air to obtain a partially acrylated epoxy resin. The material obtained was washed with ultrapure water.

[Example]

Modified epoxy resin obtained in Synthesis Example 1, NK ester BPE-500 (bisphenol A modified dimethacrylate: manufactured by Shin-Nakamura Chemical Co., Ltd.), epiclon 850 CRP (bisphenol A-type epoxy resin: manufactured by Nippon Ink Chemical Co., Ltd.), Amicoa VDH (manufactured by Ajinomoto Fine Chemical Co., Ltd.), Irgacure 184 (1-hydroxycyclohexylphenyl ketone: manufactured by Chiba Specialty Chemical Co., Ltd.), SO-EI (ultra high purity silica: manufactured by Admatech Co., Ltd.), 2MA- OK (manufactured by Shikoku Kasei) and KBM-403 (Silane Coupling Agent: manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed with a Dalton mixer at the compounding amount recorded in Table 1, and then thoroughly kneaded using three rolls to form various liquid crystal sealing agents. (S-1 to S-5) were obtained. Using these, the performance as the following liquid crystal sealing agent was evaluated. The evaluation results are shown in Table 2.

1. Viscosity Stability

Viscosity stability was evaluated by comparing the initial viscosity of the said various liquid crystal sealing agent, and the viscosity after changing various liquid crystal sealing agents with time. The viscosity of the initial value was measured at 25 degreeC with the E-type viscosity meter. The viscosity after a lapse of time was placed in a polyethylene container, sealed, and stored at 23 ° C. for 7 days, and then taken out of the container and measured at 25 ° C. with an E-type viscometer. Viscosity stability was judged by the following criteria.

○: increase in viscosity is less than 5%

(Triangle | delta): The increase rate of a viscosity is 5% or more and less than 10%

X: The increase rate of a viscosity is 10% or more

On the other hand, the initial value of liquid crystal sealing agent S-1 was 350 Pa.s.

2. Applicability

After filling a 10 cc syringe with a liquid crystal sealing agent, it was defoamed and it filled with the dispenser (Shortmaster: Musashi Engineering Co., Ltd.). Using this dispenser, it applied to the glass substrate at the speed | rate of 4 cm per second, and the drawing was performed. Application ability was judged by the following criteria.

(Circle): A sealing agent does not leak out from a desired drawing line or there is no pull, and appearance is also good.

(Triangle | delta): Although it does not leak out and pulls as mentioned above, it is bad in appearance.

X: As described above, the coating aptitude is very poor due to bleeding or thread pulling

3. adhesive strength

A 1g liquid crystal sealing agent was filled in a dispenser (Shortmaster: Musashi Engineering Co., Ltd.), and the circle of diameter 5mm was drawn on the alkali free glass of 25 mm x 45 mm and thickness 5mm. Next, the same pair of glass was bonded crosswise, and it was pressurized until the space | interval became 5 micrometers, and the space | interval was fixed by irradiating the ultraviolet-ray of 2000mJ. Subsequently, the sample was bonded by heating at 120 ° C. for 1 hour.

After the obtained sample was stored for 24 hours in a constant temperature bath at 25 ° C. and 50% humidity, the glass was parallel to the bottom surface at a rate of 2 mm / min using a tensile tester (Model 210: manufactured by Intesco). It peeled in the direction and the stress at that time was measured. The adhesive strength was obtained by dividing the stress by the area of the circle drawn with the liquid crystal sealing agent.

4. Evaluation of electrical properties of liquid crystal panel

 The TFT (thin film transistor) liquid crystal display panel was produced by the liquid crystal dropping method mentioned above using the liquid crystal sealing agent obtained by the Example. Subsequently, 1000 hours of high temperature and high humidity operation tests were performed on 60 degreeC and 95% RH conditions, and the voltage retention after a test was measured.

[Comparative Example]

NK ester BPE-500 (bisphenol A modified dimethacrylate: Shinnakamura Chemical Co., Ltd.), epiclone 850CRP (bisphenol A type epoxy resin: product made by Nippon Ink Chemical Co., Ltd.), Amicure VDH (manufactured by Ajinomoto Fine Chemical Co., Ltd.) Irgacure 184 (1-hydroxycyclohexylphenyl ketone: Chiba Specialty Chemical Co., Ltd.), SO-EI (Ultra High Purity Silica: Admatech Co., Ltd.), 2MA-OK (manufactured by Shikoku Kasei Co., Ltd.), KBM- 403 (Silane Coupling Agent: manufactured by Shin-Etsu Chemical Co., Ltd.) was mixed in a Dalton mixer at a compounding amount recorded in Table 1, and then thoroughly kneaded using three rolls to obtain a comparative liquid crystal sealing agent. Using this, evaluation similar to the Example was performed. The evaluation results are shown in Table 2.

As shown in Table 2, the liquid crystal sealing agents (S-1 to S-5) obtained by this invention are excellent in viscosity stability, application | coating suitability, adhesive strength, and voltage retention.

Since the liquid-crystal sealing agent of this invention is excellent in adhesive reliability, the electro-optical characteristic of a liquid crystal, the orientation retention property of a liquid crystal, and the viscosity stability at the time of apply | coating to the board | substrate of a liquid crystal panel, after leaving for a long time under adhesiveness and high temperature, high humidity, it is recorded. It can be used in the field of display materials.

This application claims the priority based on Japanese Patent Application No. 2005-373643 for which it applied on December 27, 2005. All content described in the said application specification is integrated in this specification.

Claims (8)

As a modified epoxy resin obtained by reacting an epoxy resin and the ester compound represented by the formula (1), The amount of the ester compound in the reaction comprises a modified epoxy resin of less than 1 mole to 1 mole of the epoxy group of the epoxy resin Liquid crystal sealing agent. Formula 1

(Formula 1, R ₁ is a hydrogen atom or a methyl group R ₂ is a hydrogen atom, an alkyl group, an alkenyl group, a halogen atom, a nitro group or a methoxy group X is a single bond, an alkylene group, a group represented by formula A or formula B) A

(Oxygen atom of formula A is bonded to carbonyl carbon of formula 1) Formula B

(In Formula A and Formula B, R ₃ is an alkylene group, and the oxygen atom of Formula B is bonded to the carbonyl carbon of Formula 1.) The method of claim 1, Liquid crystal sealing agent whose quantity of the said ester compound in the said reaction is 0.3 mol-0.7 mol with respect to 1 mol of epoxy groups of the said epoxy resin. (a) 80-20 mass% of modified epoxy resin of Claim 1, (b) 10-40 mass% of (meth) acrylic acid ester monomer or these oligomers, (c) 10-40 mass% of epoxy resin, and (a), (d) 0.1-7 mass parts of photoinitiators, (e) 3-20 mass parts of latent epoxy resin hardening | curing agents, and (f) 10-40 mass parts of fillers with respect to 100 mass parts of total (b) and (c) Liquid crystal sealing agent. The method of claim 3, wherein (g) The liquid crystal sealing agent which further contains 0.5-1.5 mass parts of spacer particles. The method of claim 3, wherein The liquid crystal sealing agent whose viscosity in 25 degreeC by E-type viscometer is 100-450 Pa.s. The sealing agent for liquid crystal dropping methods containing the epoxy resin of Claim 1, and a modified epoxy resin. Applying a sealing agent to the first substrate to form a desired frame shape; Dropwise supplying liquid crystal into the frame-shaped frame; Stacking a second substrate opposite the first substrate; Including a step of curing the sealing agent with light, The said sealing agent is a manufacturing method of the liquid crystal panel containing the modified epoxy resin of Claim 1. The method of claim 7, wherein The manufacturing method of the liquid crystal panel which further includes the process of hardening the said sealing agent by heat.