WO2007074781A1

WO2007074781A1 - Sealing material for liquid crystals and process for production of liquid crystal panels with the same

Info

Publication number: WO2007074781A1
Application number: PCT/JP2006/325797
Authority: WO
Inventors: Fumito Takeuchi; Souta Ito; Toshikazu Gomi; Yasushi Mizuta
Original assignee: Mitsui Chemicals, Inc.
Priority date: 2005-12-27
Filing date: 2006-12-25
Publication date: 2007-07-05
Also published as: JP5032340B2; TW200728873A; TWI354169B; HK1126285A1; KR20080078857A; CN101313244A; JPWO2007074781A1; CN101313244B; KR100980546B1

Abstract

The invention provides a sealing material for liquid crystals which is excellent in adhesion, adhesion reliability observed after being allowed to stand under high temperature and humidity conditions for a long time, electro-optic characteristics of liquid crystals, maintenance of alignment of liquid crystals, and viscosity stability observed in being applied to the substrate of a liquid crystal panel. The invention relates to a sealing material for liquid crystals which comprises a modified epoxy resin obtained by reacting an epoxy resin with an ester represented by the general formula (1) with the proviso that the amount of the ester used in the reaction is less than one mol per mol of epoxy of the epoxy resin: [Chemical formula 1] (1) wherein R1 is hydrogen or methyl; R2 is hydrogen, alkyl, alkenyl, halogeno, nitro, or methoxy; X is a single bond, alkylene, or a group represented by the general formula (A) or (B): [Chemical formula 2] - R3 - O - (A) [Chemical formula 3] (B) (in the formulae (A) and (B), R3 is alkylene).

Description

Specification

Liquid crystal sealing agent and liquid crystal panel manufacturing method using the same

Technical field

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

Background art

[0002] Currently, LCD panels

1) A main sealant is applied on a glass substrate to form a liquid crystal injection hole having a liquid crystal injection port, and is bonded to another pair of glass substrates to thermally cure the main sealant to produce a panel. ) After the liquid crystal is injected from the liquid crystal injection port of the panel, the liquid crystal injection part is sealed with an ultraviolet ray curable end sealant.

However, the above-mentioned liquid crystal panel manufacturing method has a long process time for injecting liquid crystal, and the glass substrate has poor adhesion due to the problem of thermal distortion caused by high temperature around 150 ° C during thermosetting. There are problems such as deviation, gap variation between glass substrates, and seepage of liquid crystal molecules with strong sealing agent.

[0003] As a method for solving these problems, 1) a photocurable resin is applied on the substrate of the liquid crystal panel to form a frame for filling the liquid crystal; 2) the liquid crystal is dropped into the frame; 3) Further, a liquid crystal panel manufacturing method using a liquid crystal dropping method in which a pair of liquid crystal panel substrates is bonded is proposed (Patent Document 1, etc.). As a resin (liquid crystal sealant) that forms a frame for filling a liquid crystal used in this method, a photo-curing acrylic adhesive mainly composed of acrylic ester or methacrylic ester (Patent Document 1). ), Mixed system of photo-curing epoxy adhesive and acrylic resin (Patent Document 2), photo-curing and heat-curing combined resin mainly composed of partially acrylic or partially methacrylated epoxy resin (Patent Document 3) has been proposed. These photo-curing sealants can be hardened at room temperature and in a short time by light irradiation. Therefore, panel creation using the above-mentioned thermosetting resin, such as shortening the time required for panel manufacture and misalignment, etc. The problem of the method is solved.

[0004] However, a photo-curing acrylic adhesive (Patent Document 1) mainly composed of acrylic acid ester or methacrylic acid ester, or a photo-curing epoxy adhesive and acrylic resin. When the mixed system (Patent Document 2) is used as a liquid crystal sealant, the adhesiveness is insufficient, and further, the adhesive reliability after being left for a long time under high temperature and high humidity, the electro-optical characteristics of the liquid crystal, Moisture resistance reliability such as orientation maintainability is insufficient.

[0005] On the other hand, when a resin mainly composed of a partial acrylic resin or a partial methallyl epoxy resin is used as a liquid crystal sealant (Patent Document 3), the adhesion and the moisture resistance reliability are improved. . However, the stability of the liquid crystal sealant's viscosity is unstable, and if the viscosity rises and the line width narrows over the process of forming the frame by applying it to the substrate of the liquid crystal panel, there will be problems and dispensers In addition, there was a problem in workability such as an increase in the number of times the sealant was replaced, and a decrease in yield was a problem.

[0006] Further, in Patent Document 4, as a partial acrylic or partial methallyl resin of epoxy resin, an epoxy resin and an ester compound are used as an epoxy group of the epoxy resin and an ester of the ester compound. A modified epoxy resin obtained by reacting with a quaternary amine as a catalyst under conditions where the group has a molar ratio of 0.5 to 2: 1 is disclosed, and the resin is also used as a sealant for display. It is disclosed that this is possible.

Patent Document 1: Patent No. 284642

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

Patent Document 3: Japanese Patent No. 3583326

Patent Document 4: JP-A 62-207241

Disclosure of the invention

Problems to be solved by the invention

[0007] As a result of intensive studies, the inventor has found that the hydroxyl group formed when (meth) acrylic epoxy resin is destabilized the viscosity stability of the liquid crystal sealant. In addition, the epoxy resin and ester compound as disclosed in Examples in Patent Document 4 have a molar ratio of the epoxy group of the epoxy resin and the ester group of the ester compound of 1: 1. It has been found that the resin obtained by reacting under the following conditions contains almost no hydroxyl group derived from an epoxy group, and therefore has insufficient adhesion as a liquid crystal sealant. Furthermore, it has been found that a resin having a low polar group concentration like the resin has a high interaction with liquid crystal molecules that are generally hydrophobic, which may impair the electro-optical properties of the liquid crystal. The present invention It came to be completed.

That is, the object of the present invention is excellent in adhesion resistance and adhesion reliability after being left for a long time under high temperature and high humidity, electro-optical properties of liquid crystal, and moisture resistance reliability such as liquid crystal alignment maintenance, and the liquid crystal panel. An object of the present invention is to provide a liquid crystal sealant having excellent viscosity stability when applied to a substrate.

Means for solving the problem

The present inventors have intensively studied, and as a liquid crystal sealant, used the resin obtained by reacting an epoxy resin and a specific ester compound under the condition that an epoxy group exists in excess. Settled. That is, the above problem is solved by the following liquid crystal sealant according to the present invention. C

[1] A modified epoxy resin obtained by reacting an epoxy resin with an ester compound represented by the formula (1),

A liquid crystal sealant containing a modified epoxy resin that is less than 1 mol relative to 1 mol of the epoxy group of the epoxy resin.

[Chemical 1]

(In Formula (1),

R is a hydrogen atom or a methyl group

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

2

Shiki

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

[Chemical 2]

— R ₃ — 0— (A)

(In formulas (A) and (B)! /, R is an alkylene group)

Three

[2] The liquid crystal sealant according to [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) the [1]榭脂80-20 mass ^_0/0 according, (b) (meth) acrylic acid ester monomer one or oligomers thereof 10 to 40 weight ^_0/0, (c) an epoxy榭fat 10 to 40 weight ^_0/0 and, (a), (b) , with respect to total 100 parts by weight of (c)

(d) A photopolymerization initiator 0.1 to 7 parts by mass, (e) a latent epoxy resin hardener 3 to 20 parts by mass, and (f) a filler 10 to 40 parts by mass of a liquid crystal sealant.

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

[5] The liquid crystal sealant according to [3] to [4], wherein the viscosity at 25 ° C. by an E-type viscometer is 100 to 450 Pa ′s.

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

[0009] Further, the above-mentioned problems are solved by the following method for producing a liquid crystal panel according to the present invention.

[7] A step of applying a sealant to the first substrate to form a desired frame shape; a step of supplying liquid crystal dropwise into the frame-shaped frame; a second surface facing the first substrate A step of overlapping the substrates; a step of curing the sealing agent with light;

A method for producing a liquid crystal panel, wherein the sealant comprises the photocurable resin composition according to [1].

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

The invention's effect

[0010] According to the present invention, it is possible to provide a liquid crystal sealant which is excellent in adhesiveness and moisture resistance reliability and has excellent viscosity stability when applied to a substrate of a liquid crystal panel.

BEST MODE FOR CARRYING OUT THE INVENTION

[0011] 1. Liquid crystal sealant A liquid crystal sealant is an adhesive or liquid crystal used to bond two substrates together in a liquid crystal display in which two substrates are bonded to each other with a certain distance between them and liquid crystal is sealed in the space. A sealant for sealing.

[0012] (a) Modified epoxy resin

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

[Chemical 4]

(In Formula (1),

R is a hydrogen atom or a methyl group

2

Shiki

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

—— R ₃ —〇一 (A)

[Chemical 6]

(In formulas (A) and (B)! /, R is an alkylene group)

Three

[0013] R is a hydrogen atom or a methyl group, and is preferably a methyl group because the glass transition temperature (Tg) of the modified epoxy resin is increased.

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

2

And is bonded to the ortho, meta or para position of the phenoxy group. R steric hindrance

2 Since the reactivity of ester compound and epoxy resin is excellent when harm is small, R is a hydrogen atom. Alternatively, a hydrogen atom is more preferable in consideration of the availability of a raw material that is preferably an alkyl having 1 to 3 carbon atoms. Also, if R is electron withdrawing, epoxy resin

2

R may be a -tro group, a black mouth group, or a methoxy group.

2

Furthermore, if R is a polymerizable functional group, the heat resistance of the modified epoxy resin cured product will be improved.

2

For superiority, R may be an alkenyl group.

2

X is a single bond (a structure in which carbon of a carboxyl group and oxygen of a phenoxy group are directly bonded), a group represented by formula (A) or formula (B). As described above, since the steric hindrance is small and the method is excellent in the reactivity between the ester compound and the epoxy resin, it is preferably a single bond.

R is an alkylene group, and the same reasoning force as described above is preferably an alkylene group having 1 to 3 carbon atoms.

Three

Good.

[0014] These compounds can be obtained by known methods. For example, an ester ichigo 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 in which X is represented by the formula (A) can be obtained, for example, by reacting acrylic acid with phenoxyalkyl alcohol or a derivative thereof. The ester compound having a structure in which X is represented by the formula (B) can be obtained by reacting phenol or this derivative with a compound obtained by reacting acrylic acid with hydroxycarboxylic acid or a derivative thereof.

In the above, in order to simplify the explanation, the case where R and R are hydrogen atoms is taken as an example.

1 2

However, the same applies to the above groups other than hydrogen atoms.

[0015] Epoxy resin is a compound having one or more epoxy groups in the molecule. The epoxy resin used for the production of the modified epoxy resin is not particularly limited, but examples thereof include the following.

Polyethylene glycols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, and polypropylene glycol, dimethylolpropane, trimethylolpropane, spiroglycol, glycerin, etc. Aliphatic polyhydric glycidyl ether compound obtained by reaction of representative polyhydric alcohols with epichlorohydrin.

[0016] Representative of bisphenol A, bisphenol S, bisphenol F, bisphenol AD, etc. Aromatic diols, and diols modified with ethylene glycol, propylene glycol, or alkylene glycol, and an aromatic polyglycidyl ether compound obtained by reaction with epichlorohydrin.

[0017] Aliphatic polyvalent glycidyl ester compound obtained by reaction of aliphatic dicarboxylic acid typified by adipic acid, itaconic acid, etc. and epichlorohydrin, isophthalic acid, terephthalic acid, pyromellitic acid It was obtained by the reaction of aromatic polycarboxylic acid ester compound obtained by the reaction of aromatic dicarboxylic acid and epichlorohydrin typified by etc., and hydroxydicarboxylic acid compound and epichlorohydrin. Aliphatic polyvalent glycidyl ether ester compound or aromatic polyvalent glycidyl ether ester compound.

[0018] Aliphatic polyvalent glycidyl ether compound, alicyclic polyvalent glycidyl ether compound obtained by reaction of aliphatic diamine represented by polyethylene diamine and epichlorohydrin , Aromatic polyvalent glycidylamine compounds obtained by the reaction of aromatic diamine and epichlorohydrin represented by diaminodiphenylmethane, arrin, metaxylylenediamine, etc., hydantoin and A hydantoin-type polyvalent glycidyl compound obtained by reaction of the derivative with epichlorohydrin.

[0019] A novolac-type polyvalent glycidyl ether compound obtained by a reaction of novolak oxalate derived from phenol or talesol and formaldehyde and epichlorohydrin, a polyalkenylphenol or a copolymer represented by such a copolymer. Epoxygenated polymers such as polyvalent glycidyl ether compounds, epoxy-polybutadiene, and epoxidized polyisoprene obtained by the reaction of phenols with epichlorohydrin, 3, 4-epoxy-6-methylcyclohexylmethyl- 3, 4-Epoxy 1-Methylenocyclohexane carbonate, bis (2,3-epoxycyclopentyl) ether, etc.

[0020] Especially, bisphenol A, bisphenol S, bisphenol due to the adhesiveness and heat resistance of the cured product? Aromatic diols typified by bisphenol AD, etc. and glycidyl ether compounds that can also produce epichlorohydrin power, or aromatic diamines typified by diaminodimethane, arrin, and xylylenediamine. Aromatic polyvalent glycidylamine compounds obtained by reaction with epichlorohydrin are preferred. Among these, in particular, a bifunctional epoxy resin having two epoxy groups in one molecule and a trifunctional epoxy having three epoxy groups. Of these, four or four-functional epoxy resins are preferred.

[0021] The molecular weight of the epoxy resin used in the production of the modified epoxy resin of the present invention is 500 to 5000 in terms of GPC (polystyrene conversion), and the soft spot temperature by DSC (the endothermic value of the endothermic curve is maximized). Is preferably 40 to 180 ° C. These epoxy resins are preferably purified by a molecular distillation method or the like in order to prevent impurities such as chloride ions from adversely affecting liquid crystal molecules.

[0022] The modified epoxy resin of the present invention can be obtained by reacting one or more types of epoxy resins selected from these with one or more types of ester compounds by a known method (special feature). (See Kaisho 62-207241). Specifically, a tertiary amine, a quaternary onium salt (ammonium salt, phosphonium salt), or a crown ether is used as a catalyst, and the reaction is performed by heating. Among them, a quaternary ammonium salt is more preferable because it is preferable to use a quaternary aluminum salt in which the reaction proceeds more effectively.

[0023] In order to prevent polymerization of the alkenyl group in the above reaction, a polymerization inhibitor may be added. Examples of the polymerization inhibitor include hydroquinone, hydroxymonomethyl ether, benzoquinone and the like.

In the above reaction, a resin having a structure in which an ester group is added to the epoxy group of the epoxy resin used as a raw material (esterified) is obtained. At this time, in order to prevent all epoxy groups from being esterified, the molar ratio of epoxy groups to ester groups may be less than 1 mole of ester groups (excess of epoxy groups) relative to 1 mole of epoxy groups. preferable. This is because, as described above, the liquid crystal sealant is excellent in viscosity stability and adhesiveness. In order to further improve these characteristics, it is preferable that the ester group is 0.3 to 0.7 mol (0.3 to 0.7 mol) with respect to 1 mol of the epoxy group. More preferably, it is 6 moles.

[0025] The ester group referred to here is an ester group having excellent reactivity with an epoxy group. That is, in the compound represented by the formula (1), it means a phenoxy ester group. However, in the formula (1), when two ester groups are present as in the ester compound represented by the formula (B), X is highly reactive, the phenoxy ester group is Yeah.

[0026] The modified epoxy resin obtained by the reaction is a molecule having an epoxy group and an ester group in one molecule, a molecule having only an epoxy group in one molecule, and an ester in one molecule. It is presumed that this is a mixture containing molecules having only a group. The mixing ratio of these is not limited, but the ratio of epoxy groups and ester groups present in the entire resin is the ratio after the epoxy group and ester group used as raw materials have reacted in approximately equimolar amounts. Is preferred! That is, a modified epoxy obtained by reacting a bifunctional epoxy resin and an ester compound with a composition in which the epoxy group of the epoxy resin and the ester group of the compound is 2: 1 (molar ratio). The ratio of epoxy groups to ester groups in the resin is preferably about 1: 1.

[0027] (b) (Meth) acrylic acid ester monomer or oligomer thereof

The liquid crystal sealant of the present invention may contain a (meth) acrylate ester monomer or an oligomer thereof in addition to the modified epoxy resin.

As the (meth) acrylic acid ester monomer used in the present invention, known monomers can be used, and examples thereof include the following.

[0028] Substituents include methyl, ethyl, propyl, butyl, amyl, 2-ethylhexyl, octyl, nonyl, dodecyl, hexadecyl, octadecyl, cyclohexyl, benzyl, methoxetyl, butoxychetyl, phenoxychetyl, nonylphenol Til, tetrahydric oral furfuryl, glycidyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-chloro-2-hydroxypropyl, dimethylaminoethyl, jetylaminoethyl, nonylphenoxy septyltetrahydrofurfuryl, force prolatatone modified tetrahydrofurfuryl, isobornyl , Monofunctional (meth) acrylates having groups such as dicyclopentanyl, dicyclopentenyl, dicyclopente-mouth kichetyl and the like.

[0029] 1,3 Butylene glycol, 1,4 butanediol, 1,5 pentanediol, 3-methyl-1,5-pentanediol, 1,6 hexanediol, neopentyl glycol, 1,8 octanediol, 1, 9-nonanediol, tricyclodecane dimethanol, ethylene glycolanol, polyethylene glycol, propylene glycol, polypropylene glycol and other di (meth) acrylates, di (meth) acrylate of tris (2-hydroxyethyl) isocyanurate, neopentyl Di (meth) acrylate of diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of glycol, and adding 2 mol of ethylene oxide or propylene oxide to 1 mol of bisphenol A Diol (di) (tri) of triol obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of di (meth) talylate and trimethylolpropane of diol obtained in 1 mol of bisphenol A Di (meth) atalylate / tris (2-hydroxyxetyl) iso cyanurate tri (meth) atalylate, trimethylolpropane tri (2) of diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide Poly (meth) atalylate, pentaerythritol tri (meth) atalylate Z dipentaerythritol poly (meth) atalylate Z-force prolatataton modified tris [(meth) atari mouth quichetil] isocyanurate, alkyl modified dipentaerythritol poly (meth) Atari rate, force prolater Poly (meth) atarylate of hydroxy-modified dipentaerythritol Zeopentylglycol dihydroxymethadiate dihydroxy (dimethacrylate), force prolatatone modified neopentylglycol dihydroxybivalate di (meth) atalylate Z ethylene oxide modified phosphoric acid ( Multifunctional (meth) acrylates such as (meth) acrylate and ethylenic oxide-modified alkylated phosphoric acid (meth) acrylate.

[0030] N-Buyl 1-Pyrrolidone, Ataliloylmorpholine, Bulleimidazole, N-Bilcaprolatatam, Buelacetate, (Meth) acrylic acid, (Meth) acrylamide, N-Hydroxymethylacrylamide or N-Hydroxyethylacrylamide And their alkyl ether compounds.

[0031] Examples of (meth) acrylic acid ester oligomers used in the present invention include polyester poly (meth) acrylate, polyether poly (meth) acrylate, polyether ester polyurethane (meth) acrylate, epoxy Poly (meth) acrylate is included. The above monomers and oligomers may be used alone or in combination.

[0032] (c) Epoxy

The liquid crystal sealant of the present invention may contain epoxy resin in addition to modified epoxy resin, (meth) acrylic acid ester monomer or oligomer thereof. As the epoxy resin, those already described can be used. Among them, it is preferable to use a resin having the same structure as the raw material of the modified epoxy resin because of its excellent compatibility with the modified epoxy resin.

[0033] The blending ratio of the component a, component b, and component c (hereinafter referred to as “mixed fat”) is 80% when the total amount is 100% by mass. 20% by mass, b component is 1 The content is preferably 0 to 40% by mass, and the component c is preferably 10 to 40% by mass. This is because it is excellent in curability, viscosity stability, adhesion and moisture resistance reliability.

[0034] (d) A photopolymerization initiator!

The liquid crystal sealant of the present invention may contain a photoinitiator. The photoinitiator is a substance that receives active light and generates active species such as radicals. The photoinitiator is not particularly limited, and the force that can use a known material includes, for example, benzophenone, 2,2-diethylacetophenone, benzyl, benzoyl isopropyl ether, benzyl dimethyl ketone. Tar, 1-hydroxycyclohexyl phenol ketone, thixanthone and the like. The photoinitiator is preferably from 0.1 to 7 parts by mass with respect to 100 parts by mass of the mixed resin. This is because the curability by light irradiation and the moisture absorption resistance of the cured product are excellent.

[0035] (e) A latent epoxy curing agent! /

The liquid crystal sealant of the present invention may contain a latent epoxy curing agent. A latent epoxy curing agent does not react with epoxy resin even if it is mixed with epoxy resin in the normal storage conditions (room temperature, visible light, etc.), but it does not react with epoxy resin by heat or light.硬化 Hardener that exhibits reactive activity. Known materials can be used for the latent epoxy curing agent, examples of which include organic acid dihydrazide compounds, imidazole and its derivatives, dicyandiamide, aromatic amines, and polyhydric phenol curing agents. The use of organic acid dihydrazide compounds is preferred. The addition amount of these curing agents is preferably 3 to 20 parts by mass with respect to 100 parts by mass of the mixed resin. This is because it has excellent viscosity stability and adhesion reliability under high temperature and high humidity.

[0036] (f) Filler

The liquid crystal sealant of the present invention may contain a filler. Known materials can be used as the filler, but examples thereof include inorganic fillers and organic fillers for the purpose of adjusting the viscosity and reducing the thermal stress of the cured product. The inorganic filler can be selected from known inorganic compounds, examples of which are calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum silicate, zirconium silicate, iron oxide, titanium oxide,匕 Aluminum (alumina), zinc oxide, silicon dioxide, potassium titanate, kaolin, tar, asbestos powder, quartz powder, mica, glass fiber, etc. are included. [0037] The organic filler can be selected from known organic compounds, and examples thereof include polymer particles obtained by copolymerization of methyl methacrylate, polystyrene, and monomers copolymerizable therewith. The particle size of the filler is not particularly limited as long as it does not affect the conduction characteristics, but it is preferably 2 μm or less.

[0038] The addition amount of these fillers is preferably 10 to 40 parts by mass with respect to 100 parts by mass of the mixed resin. It is a type that can obtain the effect of reducing thermal stress without causing a decrease in workability due to an increase in viscosity.

[0039] (g) About spacer particles

The liquid crystal sealant of the present invention may contain spacer particles. Spacer particles are particles that are added to the liquid crystal sealant to provide a gap between the substrates of the liquid crystal panel. The spacer particles are usually composed of glass, silica, polymer, etc., and the shape thereof is spherical or cylindrical. The particle diameter is appropriately adjusted depending on the distance between the substrates of the liquid crystal panel, but is usually 3 to 7 / ζ πι. The amount of the particles added is 0.5 to 1.5 parts by mass with respect to 100 parts by mass of the mixed resin. The method of mixing the particles is not particularly limited, but may be added simultaneously with the addition of the filler (f).

In the present invention, additives such as a thermosetting catalyst, a coupling agent, an ion trap agent, and an ion exchange agent can be used as necessary in addition to the above-described components. In particular, since a thermosetting reaction can be promoted, it is preferable to add a thermosetting catalyst.

[0041] The thermosetting catalyst that can be used in the present invention is a substance that accelerates the thermosetting reaction, and a known one can be used. Among them, those that are active at 70 ° C. or higher are preferable from the viewpoint of viscosity stability during work. Examples thereof include imidazole and derivatives thereof, ammine and adducts thereof, and the like. The addition amount of these curing catalysts is preferably 0.1 to 20% by mass in the liquid crystal sealant. This is because curing is accelerated by setting the amount of applied force to 0.1% by mass or more, and viscosity stability can be secured by setting it to 20% by mass or less.

[0042] When the liquid crystal sealant of the present invention is configured to include the above (a) to (f) (including (g) if necessary), the viscosity at 25 ° C by an E-type viscometer is 100. It is preferably ~ 450 Pa's, more preferably 200 to 400 Pa's. Liquid crystal sealant on liquid crystal panel substrate It is because it is excellent in workability at the time of applying to. The E type viscometer is a cone plate type rotary viscometer.

[0043] The liquid crystal sealant of the present invention can be prepared by dry blending with, for example, a Henschel mixer, which is preferably mixed uniformly, and then sufficiently melt-kneaded using a three roll. In the kneading with three rolls, the roll temperature is preferably set to 25 to 35 ° C in order to knead uniformly without causing gelling. The kneaded liquid crystal sealant is preferably defoamed so that no bubbles remain.

[0044] The liquid crystal sealant of the present invention may be used as a sealant for a liquid crystal dropping method. What is the liquid crystal dripping method?

1) Process of applying a curable resin on the first substrate and forming a frame for filling the liquid crystal

2) A step of dropping liquid crystal in the frame

3) A method of manufacturing a liquid crystal panel by a step of further bonding a second substrate to be paired and curing the cured resin.

Therefore, the sealing agent for the liquid crystal dropping method means a curable resin used in the method. The sealant for the liquid crystal dropping method can be adjusted by the method described above.

[0045] 2. Manufacturing method of liquid crystal panel

A liquid crystal panel can be produced by using the liquid crystal sealant of the present invention. The liquid crystal panel can be produced arbitrarily as long as the effects of the present invention are not impaired, but a preferred production method will be described below.

[0046] The liquid crystal panel

1) applying a sealant to the first substrate to form a desired frame shape;

2) A step of supplying liquid crystal dropwise into the frame-shaped frame,

3) superposing a second substrate facing the first substrate;

4) a step of curing the sealing agent with light;

It is manufactured through.

[0047] In the step 1), a liquid crystal sealant is applied onto the first substrate using a dispenser to form a desired frame shape. A substrate is a member that forms the basis of a display panel. It consists of a piece of glass. The liquid crystal sealant may contain spacer particles for providing a gap between the glasses.

[0048] In the step 2), a liquid crystal material corresponding to the panel internal capacity after bonding is precisely dropped into the frame. Next, in step 3), the second substrate facing the first substrate is overlaid.

[0049] In the step 4), while applying pressure to the substrate, ultraviolet rays having a wavelength of 340 to 430 nm are irradiated in an amount of 1000 to 6000 mJ, the liquid crystal sealant is photocured, and the glass substrate is bonded. A crystal panel is prepared.

Further thereafter, the liquid crystal sealant may be thermally cured by heating at 120 ° C. for 1 hour with no pressure applied, to produce a liquid crystal panel.

Example

[0050] Hereinafter, the present invention will be described by way of representative examples, but the present invention is not limited thereto. [Synthesis Example 1: Synthesis of modified epoxy resin]

Bisphenol A type epoxy resin: Epiclon EXA850CRP (Epoxy equivalent 190gZeq manufactured by Dainippon Ink & Chemicals, Inc.) 346g (epoxy group) in a 500ml four-necked flask equipped with a stirrer, gas inlet tube, thermometer, and condenser tube 1.82 mol), phenol metatalylate (ester group equivalent 162 gZeq) 162 g (1.0 mol ester group), tetraptyl ammonium bromide 16 g, hydroquinone monomethyl ether 0.1 g. Subsequently, the reaction was conducted by heating and stirring at 120 ° C. for 8 hours while publishing with dry air to obtain a modified epoxy resin (partially phenylmethacrylate epoxy resin). The obtained rosin was washed with ultrapure water.

[0051] [Synthesis Example 2: Synthesis of partial metathalyl epoxies]

In a 500 ml four-necked flask equipped with a stirrer, gas inlet tube, thermometer, and condenser tube, bisphenol A type epoxy resin: Epiclon EXA850CRP (manufactured by Dainippon Ink & Chemicals) 200 g, methacrylic acid 80 g, tri Ethanolamine 0.2g was charged. Next, it was heated and stirred at 110 ° C. for 5 hours under publishing with dry air to obtain a partially acrylic epoxy resin. The obtained material was washed with ultrapure water.

[0052] [Example] Modified epoxy resin obtained in Synthesis Example 1, NK ester BPE-500 (bisphenol A modified dimetatalylate: manufactured by Shin-Nakamura Chemical), Epiclone 850CRP (bisphenol A type epoxy resin: Dainippon Ink & Chemicals, Inc.) ), Amicure VDH (manufactured by Ajinomoto Fine Chemical), Irgacure 184 (1-hydroxycyclohexyl phenyl ketone: manufactured by Chinoku Specialty Chemicals), SO-EI (ultra-high purity silica: manufactured by Admatech), 2MA- OK (Made by Shikoku Kasei), KBM-403 (Silane coupling agent: Shin-Etsu Chemical Co., Ltd.) mixed in the amount shown in Table 1 with a Dalton mixer, and then kneaded thoroughly using three rolls. Liquid crystal sealants (S-1 to S-5) were obtained. Using these, the following performance as a liquid crystal sealant was evaluated. The evaluation results are shown in Table 2.

[0053] 1. Viscosity stability

Viscosity stability was evaluated by comparing the initial viscosity of the various liquid crystal sealants with the viscosity after changing the liquid crystal sealants over time. The initial viscosity was measured at 25 ° C with an E-type viscometer. The viscosity after the change with time was measured by using a liquid crystal sealant in a polyethylene container, hermetically sealed, stored at 23 ° C for 7 days, taken out of the container, and measured at 25 ° C with an E-type viscometer. The viscosity stability was judged according to the following criteria.

◯: Viscosity increase rate is less than 5%

Δ: Viscosity increase rate is 5% or more and less than 10%

X: Increase rate of viscosity is 10% or more

The initial value of the liquid crystal sealant S-1 was 350 Pa's.

[0054] 2. Application suitability

The liquid crystal sealant was filled into an lOcc syringe, defoamed, and then filled into a dispenser (Shot Master: manufactured by Musashi Engineering). Using this dispenser, coating was performed on a glass substrate at a speed of 4 cm per second. Application suitability was judged according to the following criteria.

◯: There is no seepage or stringing of the sealant from the desired drawing line and the appearance is good. Δ: There is no bleeding or stringing, but the appearance is poor.

X: Exudation or stringing occurs and application suitability is extremely poor

[0055] 3. Adhesive strength The liquid crystal sealant lg was filled in a dispenser (Shot Master: manufactured by Musashi Engineering Co., Ltd.), and a circle with a diameter of 5 mm was drawn on an alkali-free glass of 25 mm x 45 mm and a thickness of 5 mm. Next, a pair of similar glasses were laminated in a cross shape, pressurized until the gap was 5 m, and irradiated with 2000 mi ultraviolet rays to fix the gap. Subsequently, bonding was performed by heating at 120 ° C. for 1 hour to obtain a sample.

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

[0056] 4. Electrical characteristics evaluation of liquid crystal panel

A TFT (thin film transistor) liquid crystal display panel was produced by the liquid crystal dropping method described above using the liquid crystal sealant obtained in the examples. Subsequently, a high-temperature and high-humidity operation test was conducted for 100 hours at 60 ° C and 95% RH, and the voltage holding ratio after the test was measured.

[0057] [Comparative Example]

NK ester BPE-500 (bisphenol A modified dimetatalylate: Shin-Nakamura Chemical), Epiclon 850CRP (bisphenol A type epoxy resin: manufactured by Dainippon Ink & Chemicals), Amicure VDH (manufactured by Ajinomoto Fine Chemicals), Irgacure 184 (1—hydroxycyclohexyl ketone: manufactured by Chinoku “Specialty 1” Chemicals), SO-EI (ultra-high purity silica: manufactured by Admatech), 2MA—OK (manufactured by Shikoku Kasei), KBM—403 ( A silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.) was mixed with a Dalton mixer in the blending amounts shown in Table 1, and then thoroughly kneaded using three rolls to obtain a comparative liquid crystal sealant. Using this, the same evaluation as in the example was performed. The evaluation results are shown in Table 2.

[0058] [Table 1] Example

Composition Comparative Example

S-1 S-2 S-3 S-4 S-5 Modified epoxy resin obtained in Synthesis Example 1 50 48 48 46 78

NK ester BPE-500 (Acrylic acid ester monomer) 15 15 15 15 5 15 Epiclone 850CRP (epoxy resin) 10 10 10 10 5 10 Irgacure 184 (photoinitiator) 3 3 3 3 2 3 Amicure VDH (latent epoxy curing) Agent) 7 7 7 7 2 7

SO-EI (Ultra high purity silica) 15 15 15 15 5 15

2MA-OK (Thermosetting catalyst) 2 2 2

KBM-403 (Silane coupling agent) 2 2 1 Methacrylated epoxy resin obtained in Synthesis Example 2 50

[0059] [Table 2]

[0060] As shown in Table 2, the liquid crystal sealants (S-1 to S-5) obtained by the present invention are excellent in viscosity stability, applicability, adhesion strength, and voltage holding property.

Industrial applicability

[0061] The liquid crystal sealant of the present invention has adhesiveness, adhesion reliability after being left for a long time under high temperature and high humidity, liquid crystal electro-optical properties, liquid crystal orientation maintaining property, and when applied to a substrate of a liquid crystal panel. Can be used in the field of recording and display materials.

[0062] This application claims priority based on application number JP2005-373643 filed on December 27, 2005. All the contents described in the application specification are incorporated herein by reference.

Claims

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 an epoxy of the epoxy resin A liquid crystal sealant containing a modified epoxy resin that is less than 1 mol per 1 mol of a group. [Chemical 1]

(In Formula (1),

R is a hydrogen atom or a methyl group

2

Shiki

— R ₃ -0— (A)

[Chemical 3]

(In formulas (A) and (B)! /, R is an alkylene group)

Three

[2] The liquid crystal sealant according to claim 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) according to claim 1 modified epoxy榭脂80-20 wt% according (b) (meth) acrylic acid ester monomers or their oligomers 10-40 mass ^_0/0 (c) an epoxy榭脂10-40 (D) 0.1-7 parts by mass of a photopolymerization initiator (e) latent epoxy resin hardener 3-3% by mass and a total of 100 parts by mass of (a), (b), (c) 20 parts by mass (f) 10-40 parts by mass of filler Contains liquid crystal sealant.

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

[5] The liquid crystal sealant according to claim 3, wherein the viscosity at 25 ° C. measured by an E-type viscometer is 100 to 450 Pa ′s.

[6] A sealant for liquid crystal dropping method comprising the resin according to claim 1.

[7] A step of applying a sealant to the first substrate to form a desired frame shape; a step of dropping and supplying liquid crystal into the frame-shaped frame; a second substrate facing the first substrate A step of overlapping the sealing agent; a step of curing the sealing agent with light,

A method for producing a liquid crystal panel, wherein the sealant comprises the modified epoxy resin according to claim 1.

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