JP6793470B2 - Sealing material for liquid crystal dripping method, liquid crystal display panel and manufacturing method of liquid crystal display panel - Google Patents

Description

The present invention relates to a sealing material for a liquid crystal dropping method, a liquid crystal display panel, and a method for manufacturing a liquid crystal display panel.

Liquid crystal display panels are widely used as image display panels for various electronic devices such as mobile phones and personal computers. A liquid crystal display panel usually has a pair of substrates provided with electrodes on the surface, a frame-shaped sealing member sandwiched between them, and a liquid crystal enclosed in a region surrounded by the sealing members. ..

In recent years, in order to expand the effective screen area per unit panel of the liquid crystal display panel, it has been required to make the width of the seal member narrower than before (narrowing the frame). Along with this, it is desired that the sealing member has a higher adhesive strength per unit area than before.

Such a liquid crystal display panel is manufactured by, for example, a liquid crystal dropping method. The liquid crystal display panel is manufactured by the liquid crystal dropping method: (1) a sealing material is applied to one of the pair of substrates to form a frame-shaped seal pattern for filling the liquid crystal, and (2) the frame of the sealing pattern. The liquid crystal is dropped inside, and (3) the seal pattern is cured while the pair of substrates are superposed under high vacuum while the seal pattern is not cured.

As described above, in the liquid crystal dropping method, curing is performed in a state where the uncured sealing material and the liquid crystal are in contact with each other. Therefore, the sealing material is required to have less contamination of the liquid crystal.

As a sealing material used in the liquid crystal dropping method, a sealing material for the liquid crystal dropping method containing a compound having a butadiene-acrylonitrile copolymer skeleton, a thermosetting agent, and a filler is known (for example, Patent Document 1). Further, as a sealing material used in the liquid crystal injection method, a liquid crystal containing an epoxy resin containing an orthocresol novolac type epoxy resin and a dicyclopentadiene type epoxy resin, a curing agent, a maleated polybutadiene, a solvent, and an inorganic filler. Sealing material compositions for display elements are known (for example, Patent Document 2).

Japanese Patent No. 4452530 Japanese Unexamined Patent Publication No. 2000-221517

However, the "compound having a butadiene-acrylonitrile copolymer skeleton" contained in the sealing material for the liquid crystal dropping method of Patent Document 1 does not have sufficient flexibility because it contains an acrylonitrile skeleton. As a result, the cured product of the sealing material for the liquid crystal dropping method of Patent Document 1 has low flexibility, and the adhesive strength in the liquid crystal display panel is not sufficient. In addition, since the compound having a butadiene-acrylonitrile copolymer skeleton exhibits hydrophobicity derived from acrylonitrile, it is likely to be eluted in the liquid crystal, and there is a risk of causing liquid crystal contamination.

Further, in the composition for a sealing material of Patent Document 2, the epoxy resin is easily eluted into the liquid crystal, and the liquid crystal is easily contaminated. Further, since maleated polybutadiene is a curing agent for an epoxy resin, its content cannot be increased, and it is difficult to obtain sufficient adhesive strength.

The present invention has been made in view of the above problems. For example, for a liquid crystal dropping method which has high adhesive strength to the substrate of a liquid crystal display panel and can suppress contamination of liquid crystal even if the sealing member is narrowed. It is an object of the present invention to provide a sealing material.

（式（１）のＲは、水素原子又はメチル基を表す）
［２］ 前記水素結合性官能基が、水酸基、カルボキシ基又はウレタン結合である、［１］に記載の液晶滴下工法用シール材。
［３］ 前記（メタ）アクリル樹脂Ｂの水素結合性官能基当量が、５００〜８０００ｇ／ｅｑである、［１］又は［２］に記載の液晶滴下工法用シール材。
［４］ 前記一般式（１）で表される構造単位と前記一般式（２）で表される構造単位の合計含有量が、前記（メタ）アクリル樹脂Ｂを構成する構造単位の全質量に対して３０〜９９質量％である、［１］〜［３］のいずれかに記載の液晶滴下工法用シール材。
［５］ 前記（メタ）アクリル樹脂Ｂと前記部分（メタ）アクリル変性エポキシ樹脂Ａとの含有質量比Ｂ／Ａは、０．１〜０．５である、［１］〜［４］のいずれかに記載の液晶滴下工法用シール材。
［６］ 前記熱硬化剤Ｄは、アミン系潜在性硬化剤又はチオール系潜在性硬化剤である、［１］〜［５］のいずれかに記載の液晶滴下工法用シール材。
［７］ ［１］〜［６］のいずれかに記載の液晶滴下工法用シール材を用いて、一方の基板上に枠状のシールパターンを形成する工程と、前記シールパターンが未硬化の状態において、前記シールパターンの枠内、又は前記一方の基板と対になる他方の基板に液晶を滴下する工程と、前記一方の基板と前記他方の基板とを、前記シールパターンを介して重ね合わせる工程と、前記シールパターンを光硬化させた後、熱硬化させる工程と、を含む、液晶表示パネルの製造方法。
［８］ 一対の基板と、前記一対の基板の間に配置された枠状のシール部材と、前記一対の基板の間の前記シール部材で囲まれた空間に充填された液晶層とを含み、前記シール部材が、［１］〜［６］のいずれかに記載の液晶滴下工法用シール材の硬化物である、液晶表示パネル。 [1] A partial (meth) acrylic-modified epoxy resin A having an epoxy group and a (meth) acryloyl group, a structural unit represented by the following general formula (1), and a structural unit represented by the following general formula (2). The (meth) acrylic resin B having at least one of the above and having a hydrogen-binding functional group, a photopolymerization initiator C, a thermosetting agent D, and a filler E (provided that the portion (meth) is contained. The acrylic-modified epoxy resin A does not include the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2)), a sealing material for the liquid crystal dropping method.

(R in formula (1) represents a hydrogen atom or a methyl group)
[2] The sealing material for a liquid crystal dropping method according to [1], wherein the hydrogen-bonding functional group is a hydroxyl group, a carboxy group, or a urethane bond.
[3] The sealing material for the liquid crystal dropping method according to [1] or [2], wherein the (meth) acrylic resin B has a hydrogen-bonding functional group equivalent of 500 to 8000 g / eq.
[4] The total content of the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) is the total mass of the structural units constituting the (meth) acrylic resin B. The sealing material for the liquid crystal dropping method according to any one of [1] to [3], which is 30 to 99% by mass with respect to the above.
[5] The content mass ratio B / A of the (meth) acrylic resin B and the partial (meth) acrylic-modified epoxy resin A is 0.1 to 0.5, whichever of [1] to [4]. Sealing material for liquid crystal dripping method described in Crab.
[6] The sealing material for a liquid crystal dropping method according to any one of [1] to [5], wherein the thermosetting agent D is an amine-based latent curing agent or a thiol-based latent curing agent.
[7] A step of forming a frame-shaped seal pattern on one substrate by using the seal material for the liquid crystal dropping method according to any one of [1] to [6], and a state in which the seal pattern is uncured. In the step of dropping the liquid crystal on the frame of the seal pattern or on the other substrate paired with the one substrate, and the step of superimposing the one substrate and the other substrate on the other substrate via the seal pattern. A method for manufacturing a liquid crystal display panel, which comprises a step of photo-curing the seal pattern and then heat-curing the seal pattern.
[8] Includes a pair of substrates, a frame-shaped sealing member arranged between the pair of substrates, and a liquid crystal layer filled in a space surrounded by the sealing members between the pair of substrates. A liquid crystal display panel in which the sealing member is a cured product of the sealing material for the liquid crystal dropping method according to any one of [1] to [6].

According to the present invention, for example, it is an object of the present invention to provide a sealing material for a liquid crystal dropping method, which has high adhesive strength to a substrate of a liquid crystal display panel and can suppress contamination of liquid crystal even if the sealing member has a narrow frame. To do.

The sealing material for the liquid crystal dropping method of the present invention includes "a (meth) krill resin B containing at least one of a structural unit represented by the general formula (1) and a structural unit represented by the general formula (2)". Since such (meth) acrylic resin B has good flexibility, the cured product of the sealing material containing it has good flexibility. A liquid crystal display panel obtained by using such a sealing material can have high adhesive strength.

Further, the (meth) acrylic resin B further has a hydrogen-bonding functional group. As a result, since the (meth) acrylic resin B has appropriate hydrophilicity, it is possible to suppress elution into a liquid crystal exhibiting hydrophobicity.

Further, the sealing material for the liquid crystal dropping method of the present invention further includes "partial (meth) acrylic modified epoxy resin A". Since the partial (meth) acrylic-modified epoxy resin A can suppress the flexibility of the cured product of the sealing material from becoming too high, it can make it difficult to impair the moisture resistance of the cured product of the sealing material. The present invention has been made based on these findings.

1. 1. Sealing material for liquid crystal dripping method The sealing material for liquid crystal dripping method of the present invention includes a partial (meth) acrylic modified epoxy resin A, a specific (meth) acrylic resin B, a photopolymerization initiator C, and a thermosetting agent D. , Includes filler E. The sealing material for the liquid crystal dropping method of the present invention may further contain other components, if necessary.

1-1. Partial (meth) acrylic modified epoxy resin A
The partially (meth) acrylic-modified epoxy resin A is a resin having a (meth) acryloyl group and an epoxy group. Such a partial (meth) acrylic-modified epoxy resin A can impart photocurability and thermosetting property to the sealing material. However, the partially (meth) acrylic-modified epoxy resin A does not include the structural unit represented by the general formula (1) or the structural unit represented by the general formula (2), which will be described later. The (meth) acryloyl group means an acryloyl group or a methacryloyl group, and the (meth) acrylate means an acrylate or methacrylate.

The partially (meth) acrylic-modified epoxy resin A can be, for example, a (meth) acrylic acid glycidyl ester obtained by reacting an epoxy resin with (meth) acrylic acid in the presence of a basic catalyst.

The epoxy resin to be reacted may be a polyfunctional epoxy resin having two or more epoxy groups in the molecule. The polyfunctional epoxy resin is preferably a bifunctional epoxy resin from the viewpoint of suppressing a decrease in the adhesiveness of the cured product of the sealing material due to an excessively high crosslink density.

Examples of bifunctional epoxy resins include bisphenol type epoxy resins (bisphenol A type, bisphenol F type, 2,2'-diallyl bisphenol A type, bisphenol AD type, hydrogenated bisphenol type, etc.), biphenyl type epoxy resins, and the like. And naphthalene type epoxy resin are included. Among them, bisphenol A type and bisphenol F type bisphenol type epoxy resins are preferable from the viewpoint of good coatability. The bisphenol type epoxy resin has advantages such as excellent coatability as compared with the biphenyl ether type epoxy resin.

Examples of the partially (meth) acrylic-modified epoxy resin A include methacrylic-modified bisphenol A-type epoxy resin (KSM, BAEM-50, etc.), acrylic-modified bisphenol F-type epoxy resin (KSM, BFEA-50, etc.), A methacrylic-modified bisphenol E type epoxy resin (manufactured by KSM, BEEM-50, etc.) is included.

The modified amount of the (meth) acryloyl group of the partially (meth) acrylic-modified epoxy resin A is preferably 30 to 80%. When the amount of modification is 30% or more, compatibility with the (meth) acrylic resin B can be easily obtained. The amount of modification of the (meth) acryloyl group can be adjusted, for example, by the number of moles of (meth) acrylic acid that reacts with the epoxy resin as a raw material.

The partial (meth) acrylic-modified epoxy resin A may be of one type or a combination of two or more types.

The weight average molecular weight of the partially (meth) acrylic-modified epoxy resin A is preferably about 310 to 1000. When the weight average molecular weight of the partial (meth) acrylic-modified epoxy resin A is 310 or more, it is difficult to dissolve in the liquid crystal, so that it is easy to suppress the contamination of the liquid crystal. When it is 1000 or less, the viscosity of the sealing material becomes too high. Can be suppressed. The weight average molecular weight of the partially (meth) acrylic-modified epoxy resin A can be measured, for example, by gel permeation chromatography (GPC) in terms of polystyrene.

1-2. (Meta) Acrylic resin B
1-2-1. Structure and Physical Properties of (Meta) Acrylic Resin B The (meth) acrylic resin B has at least one of a structural unit represented by the general formula (1) and a structural unit represented by the general formula (2), and ( Meta) A resin having an acryloyl group and a hydrogen-bonding functional group.

The structural unit represented by the general formula (1) is a structural unit derived from isoprene or 1,3-butadiene. R in the general formula (1) represents a hydrogen atom or a methyl group. The structural unit represented by the general formula (2) is a structural unit derived from 1,2-butadiene. Hereinafter, 1,3-butadiene and 1,2-butadiene are collectively referred to as butadiene.

The total content of the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) is 30 to 99 with respect to the total mass of the structural units constituting the (meth) acrylic resin B. It is preferably mass%. When the total content of the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) is within the above range, it is easy to impart sufficient flexibility to the (meth) acrylic resin B. , It is easy to increase the adhesive strength of the cured product of the sealing material. The total content of the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) is 50 to 98 with respect to the total mass of the structural units constituting the (meth) acrylic resin B. More preferably, it is by mass%.

The (meth) acryloyl group may be present at at least one of the molecular main chain and the molecular terminal of the (meth) acrylic resin B. Since the (meth) acrylic resin B having a (meth) acryloyl group can be crosslinked with other resins, it is difficult to elute into the liquid crystal, and it is possible to suppress contamination of the liquid crystal material.

The (meth) acryloyl group equivalent of the (meth) acrylic resin B is preferably 1000 to 8000 g / eq, and more preferably 1500 to 7000 g / eq. When the (meth) acryloyl group equivalent is 1000 g / eq or more, the adhesive strength can be increased without impairing the photocurability of the sealing material. When the (meth) acryloyl group equivalent is 8000 g / eq or less, sufficient photocurability can be imparted to the sealing material without impairing the adhesive strength.

The (meth) acryloyl group equivalent of the (meth) acrylic resin B is defined by the following formula.

The (meth) acryloyl group equivalent of the (meth) acrylic resin B was measured by measuring the weight average molecular weight of the (meth) acrylic resin B by the Gel Permeation Chromatography (GPC) method, and the (meth) acrylic resin B had (meth) acrylic resin B (meth). Meta) To determine the content ratio of the acryloyl group to the structural unit represented by the general formula (1) or (2) by measuring the content ratio by the Nuclear Magnetic Resonance (NMR) method and applying them to the above formula. Can be done.

The (meth) acryloyl group equivalent of the (meth) acrylic resin B can be adjusted by the number of moles of the (meth) acrylicloyl group-containing compound to be reacted with polybutadiene or polyisoprene having a reactive functional group as described later.

The hydrogen-bonding functional group can be a hydroxyl group, a carboxy group, or a urethane bond. These hydrogen-bonding functional groups can impart hydrophilicity to the (meth) acrylic resin B and the sealing material containing the same. As a result, it is possible to prevent the (meth) acrylic resin B from eluting into the liquid crystal material and contaminating the liquid crystal material.

The hydrogen-bonding functional group equivalent of the (meth) acrylic resin B is preferably 500 to 8000 g / eq. When the hydrogen-bonding functional group equivalent is 500 g / eq or more, the hydrophilicity of the sealing material does not increase too much, so that not only unnecessary reaction with the hydrophilic curing agent is unlikely to occur, but also the moisture resistance of the cured product is improved. Hard to be damaged. When the hydrogen-bonding functional group equivalent is 8000 g / eq or less, the (meth) acrylic resin B can be imparted with appropriate hydrophilicity, so that elution into the liquid crystal material can be easily suppressed.

The hydrogen-bonding functional group equivalent of the (meth) acrylic resin B is defined by the following formula.

The hydrogen-bonding functional group equivalent of the (meth) acrylic resin B can be measured in the same manner as the above-mentioned method for measuring the (meth) acryloyl group equivalent.

The hydrogen-bonding functional group can be introduced by the reaction of polybutadiene or polyisoprene having a reactive functional group with a (meth) acryloyl group-containing compound, as will be described later. Therefore, the hydrogen-bonding functional group equivalent of the (meth) acrylic resin B can be adjusted by the number of moles of the (meth) acryloyl group-containing compound to be reacted with polybutadiene or polyisoprene having a reactive functional group.

As described above, since the hydrogen-bonding functional group is often introduced in association with the introduction reaction of the (meth) acryloyl group, the hydrogen-bonding functional group and the (meth) acryloyl group can be contained in the same structural unit. ..

An example of a structural unit having both a (meth) acryloyl group and a hydrogen-bonding functional group is a reaction product of a (meth) acryloyl group-containing compound having an isocyanate group and a terminal hydroxyl group in a hydroxyl-terminated polybutadiene or a hydroxyl-terminal polyisoprene. Derived structural units (see formula (3) below) and; structural units derived from the ring-opening modified maleic anhydride of butadiene or isoprene (see formula (4) below) are included. Examples of the maleic anhydride ring-opening modified product of butadiene or isoprene include those in which the maleic anhydride group of the maleic anhydride modified product of butadiene or isoprene is ring-opened with a hydroxyl group-containing acrylate. R in the general formula (4) represents a hydrogen atom or a methyl group.

The (meth) acrylic resin B may further contain other structural units other than the above as long as the effects of the present invention are not impaired. Examples of other structural units include structural units derived from maleic anhydride-modified butadiene or isoprene that remain without ring-opening reaction with the above-mentioned hydroxyl group-containing acrylate.

However, the (meth) acrylic resin B preferably does not contain a structural unit derived from acrylonitrile. This is because the structural unit derived from acrylonitrile easily enhances the hydrophobicity of the (meth) acrylic resin B and easily elutes into the liquid crystal material. Further, the cured product of the (meth) acrylic resin containing the structural unit derived from acrylonitrile has lower flexibility than the cured product not containing the structural unit, so that the adhesive strength of the liquid crystal display panel is likely to be impaired.

Examples of (meth) acrylic resin B include polybutadiene acrylic resin (TE-2000 manufactured by Nippon Soda Co., Ltd.), polyisoprene acrylic resin (UC-203 etc. manufactured by Kuraray Co., Ltd.), and the terminal described in International Publication No. 2012/039244. Acrylic-modified polybutadiene and the like are included.

The weight average molecular weight of the (meth) acrylic resin B is preferably 1000 to 50,000, and more preferably 2000 to 40,000. When the weight average molecular weight of the (meth) acrylic resin B is 1000 or more, the (meth) acrylic resin B tends to have sufficient flexibility, and when it is 50,000 or less, it is different from the partial (meth) acrylic modified epoxy resin A. Compatibility is not easily impaired.

1-2-2. Method for synthesizing (meth) acrylic resin B The (meth) acrylic resin B is produced by any method, and is produced by, for example, polybutadiene or polyisoprene having a reactive functional group (having a reactive functional group and having a general formula (meth). A resin having at least one of the structural unit represented by 1) and the structural unit represented by the general formula (2)) can be obtained by modifying it with a (meth) acryloyl group-containing compound.

Examples of reactive functional groups in "polybutadiene or polyisoprene having a reactive functional group" include hydroxyl groups, carboxy groups, epoxy groups, and acid anhydride groups (eg maleic anhydride groups). Of these, a hydroxyl group, an epoxy group, and an acid anhydride group are preferable because a hydrogen-bonding functional group can be introduced by a reaction with a (meth) acryloyl group-containing compound. The reactive functional group may be at the molecular terminal of polybutadiene or polyisoprene, or at the molecular main chain. Examples of polybutadiene or polyisoprene having a reactive functional group include hydroxyl group-terminated polybutadiene (or polyisoprene) (for example, G series manufactured by Nippon Soda Co., Ltd.) and acid anhydride group-modified polybutadiene (or polyisoprene) (for example, CRAY VALLY). Ricon ^R MA series manufactured by Nippon RMA series), epoxidized polybutadiene (or polyisoprene) (for example, JP series manufactured by Nippon Soda Co., Ltd.) and the like are included.

An example of the (meth) acryloyl group-containing compound is preferably a (meth) acrylic acid ester. Examples of (meth) acrylic acid esters include (meth) acrylic acid alkyl esters such as methyl (meth) acrylate and ethyl (meth) acrylate.

The (meth) acryloyl group-containing compound may further have a reactive functional group. The reactive functional group contained in the (meth) acryloyl group-containing compound may be a group that reacts with the reactive functional group of polybutadiene or polyisoprene, and examples thereof include an isocyanate group, a carboxy group and a hydroxyl group. Examples of "(meth) acryloyl group-containing compounds having reactive functional groups" include (meth) acrylic acid esters having hydroxyl groups (eg, hydroxyalkyl acrylates), (meth) acrylic acids, and (meth) having isocyanate groups. Acryloyl group-containing compounds (compounds represented by the following general formula (5), see International Publication No. 2012/039244) are included. R in the general formula (5) represents a hydrogen atom or a methyl group; R'' represents an alkylene group or a cycloalkylene group; R'''' represents an alkylene group, a cycloalkylene group, an arylene group or a heteroarylene group. Represents.

The introduction of hydrogen-bonding functional groups can be carried out, for example, by modifying polybutadiene or polyisoprene having a reactive functional group with a (meth) acryloyl group-containing compound.

For example, the hydroxyl group of "polybutadiene or polyisoprene having a hydroxyl group" is reacted with an isocyanate group of "a (meth) acryloyl group-containing compound having an isocyanate group" (see, for example, general formula (5)) to have a "urethane bond". (Meta) acrylic resin B ”can be obtained. The maleic anhydride group of "polybutadiene or polyisoprene having a maleic anhydride group" is reacted with the hydroxyl group of the "(meth) acryloyl group-containing compound having a hydroxyl group" to "(meth) acrylic resin B having a carboxy group". (See general formula (4)) can be obtained.

The total content of the partial (meth) acrylic-modified epoxy resin A and the (meth) acrylic resin B in the sealing material for the liquid crystal dropping method is preferably 40 to 90% by mass with respect to the total mass of the sealing material. When the total content of the partial (meth) acrylic modified epoxy resin and the (meth) acrylic resin B is 40% by mass or more, the content ratio of the structural unit represented by the general formula (1) or (2) in the sealing material is determined. Since the number can be increased, it is easy to impart high flexibility to the cured product of the sealing material, and it is easy to increase the adhesive strength of the cured product of the sealing material. When the total content of the partially (meth) acrylic modified epoxy resin and the (meth) acrylic resin B is 90% by mass or less, the moisture resistance of the cured product of the sealing material is not easily impaired. The total content of the partial (meth) acrylic modified epoxy resin and the (meth) acrylic resin B in the sealing material is more preferably 60 to 85% by mass with respect to the total mass of the sealing material.

The content mass ratio B / A of the (meth) acrylic resin B and the partially (meth) acrylic-modified epoxy resin A is preferably 0.1 to 0.5. When the content mass ratio B / A is 0.1 or more, the content ratio of the structural unit represented by the general formula (1) or (2) can be increased, so that the flexibility of the cured product of the sealing material can be increased. Easy to raise. When the content mass ratio B / A is 0.5 or less, the content ratio of the structural unit represented by the general formula (1) or (2) is not too large, so that the flexibility of the cured product of the sealing material is impaired. It is easy to improve the moisture resistance.

1-3. Photopolymerization initiator C
The photopolymerization initiator C is a photoradical polymerization initiator for allowing a partially (meth) acrylic-modified epoxy resin A or a (meth) acrylic resin B to undergo a photocuring reaction.

Examples of photoradical polymerization initiators include alkylphenone compounds, acylphosphine oxide compounds, titanosen compounds, oxime ester compounds, benzoin compounds, acetophenone compounds, benzophenone compounds, thioxone compounds, and α-acido. Xim ester compounds, phenylglioxylate compounds, benzyl compounds, azo compounds, diphenyl sulfide compounds, organic dye compounds, iron-phthalocyanine compounds, benzoin ether compounds, anthraquinone compounds and the like are included. Of these, alkylphenone-based compounds, acylphosphine oxide-based compounds, titanocene-based compounds, and oxime ester-based compounds are preferable.

Examples of alkylphenone compounds include benzyl dimethyl ketals such as 2,2-dimethoxy-1,2-diphenylethane-1-one (IRGACURE 651); 2-methyl-2-morpholino (4-thiomethylphenyl) propane. Includes α-aminoalkylphenones such as -1-one (IRGACURE 907); α-hydroxyalkylphenones such as 1-hydroxy-cyclohexyl-phenyl-ketone (IRGACURE 184). Examples of acylphosphine oxide compounds include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and the like. Titanocene compounds include bis (η5-2,4-cyclopentadiene-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole-1-yl) -phenyl) titanium and the like. Examples of oxime ester compounds include 1,2-octanedione-1- [4- (phenylthio) -2- (O-benzoyloxime)] (IRGACURE OXE 01) and the like.

The content of the photopolymerization initiator C in the sealing material for the liquid crystal dropping method is 0.01 to 3.0% by mass with respect to the total mass of the partially (meth) acrylic-modified epoxy resin A and the (meth) acrylic resin B. Is preferable. When the content of the photopolymerization initiator C is 0.01% by mass or more, the curability of the sealing material is good. On the other hand, when the content of the photopolymerization initiator C is 3.0% by mass or less, the stability at the time of coating on the substrate is good.

1-4. Thermosetting agent D
The thermosetting agent D is a compound that does not cure the partially (meth) acrylic-modified epoxy resin A under normal storage conditions (room temperature, visible light, etc.), but cures the resin when heat is applied. The sealing material containing the thermosetting agent D is excellent in storage stability and thermosetting property.

The melting point or softening point of the thermosetting agent D is preferably 50 to 250 ° C., although it depends on the thermosetting temperature, from the viewpoint of enhancing the viscosity stability of the sealing material and not impairing the moisture resistance of the cured product. More preferably, it is 70 to 200 ° C.

The thermosetting agent D is preferably an epoxy curing agent. Examples of epoxy curing agents include amine-based latent curing agents and thiol-based latent curing agents.

Examples of amine-based latent curing agents include organic acid dihydrazide-based latent curing agents, imidazole-based latent curing agents, amine adduct-based latent curing agents, and polyamine-based latent curing agents.
Examples of organic acid dihydrazide-based latent curing agents include adipic acid dihydrazide (melting point 181 ° C.), 1,3-bis (hydrazinocarboethyl) -5-isopropylhydranthin (melting point 120 ° C.), 7,11-octadeca. Diene-1,18-dicarbohydrazide (melting point 160 ° C.), dodecane diic acid dihydrazide (melting point 190 ° C.), sebacic acid dihydrazide (melting point 189 ° C.) and the like are included.
Examples of imidazole-based latent curing agents include 2,4-diamino-6- [2'-ethylimidazolyl- (1')]-ethyltriazine (melting point 215-225 ° C.) and 2-phenylimidazole (melting point 137-). 147 ° C.), and 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-triazine isocyanuric acid adduct and the like.
The amine adduct-based latent curing agent is a latent curing agent composed of an additional compound obtained by reacting an amine-based compound having catalytic activity with an arbitrary compound, and an example thereof is manufactured by Ajinomoto Fine-Techno Co., Ltd. Amicure PN-40 (melting point 110 ° C), Ajinomoto Fine-Techno Co., Ltd. Amicure PN-23 (melting point 100 ° C), Ajinomoto Fine-Techno Co., Ltd. Amicure PN-31 (melting point 115 ° C), Ajinomoto Fine-Techno Co., Ltd. Amicure PN-H (melting point 115 ° C.), Ajinomoto Fine-Techno Co., Ltd. Amicure MY-24 (melting point 120 ° C.), Ajinomoto Fine-Techno Co., Ltd. Amicure MY-H (melting point 131 ° C.), and the like are included.
The polyamine-based latent curing agent is a latent curing agent having a polymer structure obtained by reacting an amine with an epoxy, and an example thereof is ADEKA Hardener EH4339S (softening point 120 to 130 ° C.) manufactured by ADEKA Corporation. , And ADEKA Hardener EH4357S (softening point 73 to 83 ° C.) manufactured by ADEKA Corporation.

Examples of thiol-based curing agents include trimethylolpropanthris (thioglycolate), pentaerythritol tetrakis (thioglycolate), ethylene glycol dithioglycolate, trimethylolpropanthris (β-thiopropionate), pentaerythritol tetrakis. A thiol compound obtained by an esterification reaction of a polyol such as (β-thiopropionate) and dipentaerythritol poly (β-thiopropionate) with a thiol organic acid; 1,4-butanedithiol, 1,6-hexane. Alkyl polythiol compounds such as dithiol and 1,10-decandithiol; terminal thiol group-containing polyether; terminal thiol group-containing polythioether; thiol compound obtained by reaction of epoxy compound and hydrogen sulfide; obtained by reaction of polythiol and epoxy compound. A thiol compound having a terminal thiol group and the like are included.

The thermosetting agent D may be only one type or a combination of two or more types.

The content of the thermosetting agent D in the sealing material for the liquid crystal dropping method is preferably 3 to 30% by mass with respect to the total mass of the partially (meth) acrylic-modified epoxy resin A and the (meth) acrylic resin B. The sealing material containing the thermosetting agent D can be a one-component curable resin composition. The one-component curable resin composition is excellent in workability because it is not necessary to mix the main agent and the curing agent at the time of use. When the content of the thermosetting agent D is 3% by mass or more, the thermosetting reaction of the partial (meth) acrylic-modified epoxy resin A is more likely to be promoted.

1-5. Filler E
The filler E can adjust the viscosity of the sealing material, the strength of the cured product, the linear expandability, and the like. The filler E can be an inorganic filler or an organic filler.

Examples of inorganic fillers are calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum silicate, zirconium silicate, iron oxide, titanium oxide, titanium nitride, aluminum oxide (alumina), zinc oxide, silicon dioxide, potassium titanate. , Kaolin, talc, glass beads, sericite activated clay, bentonite, aluminum nitride, silicon nitride and the like. Of these, silicon dioxide and talc are preferred.

Examples of organic fillers include thermoplastic resin particles. The thermoplastic resin particles are particles containing a thermoplastic resin having a softening point temperature of 50 to 120 ° C., preferably 70 to 100 ° C., as measured by the ring-and-ball method. Since the sealing material containing such thermoplastic resin particles can preferably relieve the shrinkage stress during heat curing, it is easy to form the sealing member with a target line width.

Examples of the thermoplastic resin particles include fine particles obtained by suspend-polymerizing a resin containing an epoxy group and a double bond group with a monomer capable of radical polymerization. Examples of resins containing an epoxy group and a double bond group include a resin obtained by reacting a bisphenol F type epoxy resin and methacrylic acid in the presence of a tertiary amine. Examples of radically polymerizable monomers include butyl acrylate, glycidyl methacrylate, and divinylbenzene.

The shape of the filler E may be a fixed shape such as a spherical shape, a plate shape, or a needle shape, or may be a non-fixed shape.

When the filler E is a spherical inorganic filler, the average primary particle size of the filler E is preferably 1.5 μm or less, and the specific surface area is preferably 0.5 to ²⁰ m ² / g. The average primary particle size of the filler E can be measured by the laser diffraction method described in JIS Z8825-1. The specific surface area of the filler E can be measured by the BET method described in JIS Z8830.

When the filler E is a spherical organic filler, the number average particle size of the organic filler is preferably 0.05 to 5 μm, preferably 0.1 to 3 μm. The number average particle size can be measured with a dry particle size counter.

The content of the filler E in the sealing material for the liquid crystal dropping method is preferably 5 to 30% by mass with respect to the total mass of the sealing material. When the content of the filler E is 5% by mass or more, the moisture resistance of the cured product of the sealing material is easily increased, and when it is 30% by mass or less, the coating stability of the sealing material is not easily impaired. The above range may correspond to a range of 5.5 to 75% by mass with respect to the total mass of the partially (meth) acrylic modified epoxy resin A and the (meth) acrylic resin B.

1-6. Other Components The sealing material for the liquid crystal dropping method of the present invention may further contain other components as long as the effects of the present invention are not impaired. Examples of other components include other (meth) acrylic resins, thermosetting resins, thermal radical polymerization initiators, coupling agents such as silane coupling agents, ion trapping agents, ion exchangers, leveling agents, pigments, etc. Includes dyes, plasticizers, defoamers and spacers for adjusting gaps in liquid crystal display panels. Among them, the sealing material for the liquid crystal dropping method of the present invention may contain other (meth) acrylic resin, thermosetting resin, or silane coupling agent.

1-6-1. Other (meth) acrylic resin F
The other (meth) acrylic resin F is a resin having a (meth) acryloyl group. However, the other (meth) acrylic resin F does not contain an epoxy group unlike the above-mentioned partial (meth) acrylic modified epoxy resin A; unlike the (meth) acrylic resin B, it is represented by the general formula (1). It does not include the structural unit to be used or the structural unit represented by the general formula (2). The number of (meth) acryloyl groups per molecule of the (meth) acrylic resin F is 1 or 2 or more. The other (meth) acrylic resin F may be a monomer of a compound having a (meth) acrylic group, or may be an oligomer or a polymer.

Examples of resins having one (meth) acryloyl group in one molecule include (meth) acrylic acids such as methyl (meth) acrylate, ethyl (meth) acrylate, and 2-hydroxyethyl ester of (meth) acrylic acid. Includes alkyl esters.

Examples of resins having two or more (meth) acryloyl groups in one molecule include di (meth) acrylates such as polyethylene glycol, propylene glycol and polypropylene glycol; di (meth) of tris (2-hydroxyethyl) isocyanurate. Acrylate: Di (meth) acrylate of diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of neopentyl glycol; diol obtained by adding 2 mol of ethylene oxide or propylene oxide to 1 mol of bisphenol A. Di (meth) acrylate; Di or tri (meth) acrylate of triol obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of trimethylolpropane; 4 mol or more of ethylene oxide or propylene to 1 mol of bisphenol A Di (meth) acrylate of diol obtained by adding oxide; tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate; trimethylol propantri (meth) acrylate or oligomer thereof; pentaerythritol tri (meth) acrylate Or an oligomer thereof; poly (meth) acrylate of dipentaerythritol; tris (acryloxyethyl) isocyanurate; caprolactone-modified tris (acryloxyethyl) isocyanurate; caprolactone-modified tris (methacryloxyethyl) isocyanurate; alkyl-modified dipentaerythritol Polyacrylate or polymethacrylate; Polyacrylate or polymethacrylate of caprolactone-modified dipentaerythritol; Neopentyl glycol diacrylate or dimethacrylate of hydroxypivalate; Neopentyl glycol di (meth) acrylate of caprolactone-modified hydroxypivalate; Ethyleneoxide-modified phosphoric acid Acrylate or dimethacrylate; ethylene oxide-modified alkylated phosphoric acid (meth) acrylate; neopentylglucol, trimethylolpropane, oligo (meth) acrylate of pentaerythritol and the like are included.

Examples of other commercially available products of the (meth) acrylic resin F include BAEA-100 (acrylic modified bisphenol A type epoxy resin) and BAEM-100 (methacrylic modified bisphenol A type epoxy resin) manufactured by KSM.

1-6-2. Thermosetting resin G
The thermosetting resin G is preferably an epoxy resin. However, the epoxy resin is different from the partially (meth) acrylic-modified epoxy resin A and does not have a (meth) acryloyl group. The sealing material containing an epoxy resin has low solubility and diffusibility in liquid crystal, and can not only improve the display characteristics of the obtained liquid crystal display panel but also enhance the moisture resistance of the cured product.

The epoxy resin is preferably an aromatic epoxy compound. Examples of aromatic epoxy resins include aromatic diols typified by bisphenol A, bisphenol S, bisphenol F, bisphenol AD, etc., and diols obtained by modifying them with ethylene glycol, propylene glycol, alkylene glycol, and reaction with epichlorohydrin. Aromatic polyvalent glycidyl ether compound obtained in the above; Novolac resin derived from phenol or cresol and formaldehyde, polyphenols represented by polyalkenylphenol and its copolymers, etc., and novolak type obtained by reaction with epichlorohydrin. Polyvalent glycidyl ether compound; glycidyl ether compounds of xylylene phenol resin and the like are included. Among them, cresol novolac type epoxy compound, phenol novolac type epoxy compound, bisphenol A type epoxy compound, bisphenol F type epoxy compound, triphenol methane type epoxy compound, triphenol ethane type epoxy compound, trisphenol type epoxy compound, dicyclopentadiene type. Epoxy compounds, diphenyl ether type epoxy compounds and biphenyl type epoxy compounds are preferable. The epoxy compound may be one kind or a combination of two or more kinds.

The epoxy resin may be liquid or solid. A solid epoxy compound is preferable from the viewpoint of easily suppressing liquid crystal contamination. The softening point of the solid epoxy compound is preferably 40 to 150 ° C.

Examples of the epoxy resin include a bisphenol A type epoxy resin (1001, solid state manufactured by Mitsubishi Chemical Corporation) and a bisphenol A type epoxy resin (825 manufactured by Mitsubishi Chemical Corporation, liquid).

The weight average molecular weight of the epoxy resin is preferably 500 to 10000. When the weight average molecular weight of the epoxy resin is 500 or more, it is difficult to dissolve in the liquid crystal, so that it is easy to suppress the contamination of the liquid crystal. When it is 10,000 or less, it is easy to prevent the viscosity of the sealing material from becoming too high. The weight average molecular weight of the epoxy resin is more preferably 1000 to 5000. The weight average molecular weight of the epoxy resin can be measured by gel permeation chromatography (GPC) in terms of polystyrene.

1-6-3. Silane coupling agent H
Examples of the silane coupling agent H include vinyltrimethoxysilane, γ- (meth) acryloxipropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and the like. ..

The content of the silane coupling agent H in the sealing material for the liquid crystal dropping method may be 0.01 to 3% by mass with respect to the total mass of the sealing material. When the content of the silane coupling agent H is 0.01% by mass or more, the cured product of the sealing material tends to have sufficient adhesiveness.

1-7. Physical Properties of Sealing Material for Liquid Crystal Dropping Method The viscosity of the sealing material for liquid crystal dropping method of the present invention at 25 ° C. and 2.5 rpm is preferably 200 to 450 Pa · s. When the viscosity of the sealing material is within the above range, the applicability by the dispenser becomes good. The viscosity of the sealing material is more preferably 300 to 400 Pa · s. The viscosity of the sealing material can be measured with an E-type viscometer.

2. 2. Liquid crystal display panel and its manufacturing method The liquid crystal display panel of the present invention is composed of a pair of substrates, a frame-shaped seal member arranged between the pair of substrates, and a frame-shaped seal member between the pair of substrates. Includes a liquid crystal layer filled in the enclosed space. The sealing member can be a cured product of the sealing material for the liquid crystal dropping method of the present invention.

The pair of substrates are all transparent substrates. The material of the transparent substrate is glass or plastic such as polycarbonate, polyethylene terephthalate, polyether sulfone and PMMA.

A matrix-like TFT, a color filter, a black matrix, or the like may be arranged on the surface of one of the pair of substrates. An alignment film may be further arranged on the surface of the one substrate. The alignment film includes a known organic alignment agent or an inorganic alignment agent.

The liquid crystal display panel is manufactured by using the sealing material for the liquid crystal dropping method of the present invention. The method for manufacturing a liquid crystal display panel generally includes a liquid crystal dropping method and a liquid crystal injection method, but the liquid crystal display panel of the present invention is preferably manufactured by the liquid crystal dropping method.

The manufacturing method of the liquid crystal display panel by the liquid crystal dropping method is
1) A step of forming a seal pattern of the seal material for the liquid crystal dropping method of the present invention on one substrate, and
2) In a state where the seal pattern is uncured, a step of dropping the liquid crystal into the region surrounded by the seal pattern of the substrate or the region of the other substrate facing the region surrounded by the seal pattern.
3) The process of superimposing one substrate and the other substrate via a seal pattern,
4) Includes a step of curing the seal pattern.

In the step 2), the state in which the seal pattern is uncured means a state in which the curing reaction of the sealing material has not progressed to the gel point. Therefore, in the step 2), the seal pattern may be semi-cured by irradiating or heating the seal pattern in order to suppress the dissolution of the seal material in the liquid crystal.

In the step 4), it is preferable to perform curing by light irradiation and then by heating. By curing by light irradiation, the sealing material can be cured in a short time, so that dissolution in the liquid crystal can be suppressed. By combining curing by light irradiation and curing by heating, damage to the liquid crystal layer due to light can be reduced as compared with the case where only curing by light irradiation is performed.

The light to be irradiated is preferably light having a wavelength of 340 to 450 nm. This is because light having the above wavelength causes relatively little damage to the liquid crystal and the drive electrode. For the irradiation of light, a known light source that emits ultraviolet rays or visible light can be used. When irradiating visible light, a high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, a xenon lamp, a fluorescent lamp, or the like can be used.

The light irradiation energy may be any energy sufficient to cure the (meth) acrylic resin B, and may be, for example, about 100 mW / cm ² . The light curing time depends on the composition of the sealing material and the light irradiation energy, but for example, the integrated irradiation amount may be set to 3 J / cm ² or more, and when irradiating with a light irradiation energy of 100 mW / cm ^2. It can be within 1 minute.

The thermosetting temperature may be, for example, 120 ° C., and the thermosetting time may be about 1 to 2 hours, although it depends on the composition of the sealing material.

The sealing material for the liquid crystal dropping method of the present invention has reduced elution into the liquid crystal. Therefore, the liquid crystal display panel having the cured product of the sealing material for the liquid crystal dropping method of the present invention can have high quality display performance with less contamination of the liquid crystal.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples do not limit the scope of the invention.

1. 1. Material of sealing material for liquid crystal dripping method (1) Part (meth) Acrylic modified epoxy resin A
Methacrylic modified bisphenol A type epoxy resin: manufactured by KSM, BAEM-50, methacrylic modification rate 50%

ポリイソプレンアクリル樹脂：クラレ社製ＵＣ−２０３、重量平均分子量３６０００、アクリロイル基当量６７００ｇ／ｅｑ、水素結合性官能基（カルボキシ基）当量６７００ｇ／ｅｑ（下記式参照）、ポリイソプレンアクリル樹脂（ＵＣ−２０３）を構成する構造単位の全質量に対する一般式（１）で表される構造単位の含有量＝９８質量％

尚、上記式は、一般式（１）で表される構造単位と一般式（３）で表される構造単位とを含むことを示したものであり、必ずしも一般式（１）で表される構造単位と一般式（３）で表される構造単位とが交互に結合していることを示すものではない。 (2) (Meta) Acrylic Resin (2-1) (Meta) Acrylic Resin B
Polybutadiene acrylic resin: TE-2000 manufactured by Nippon Soda Co., Ltd., weight average molecular weight 2500, acryloyl group equivalent 1600-2100 g / eq, hydrogen-binding functional group (urethane bond) equivalent 800-1050 g / eq (see formula below), polybutadiene acrylic resin Content of structural unit represented by general formula (2) with respect to total mass of structural unit constituting (TE-2000) = 61 mass%

Polyisoprene acrylic resin: UC-203 manufactured by Kuraray, weight average molecular weight 36000, acryloyl group equivalent 6700 g / eq, hydrogen-binding functional group (carboxy group) equivalent 6700 g / eq (see formula below), polyisoprene acrylic resin (UC- Content of structural unit represented by general formula (1) = 98% by mass with respect to total mass of structural units constituting 203)

The above formula shows that the structural unit represented by the general formula (1) and the structural unit represented by the general formula (3) are included, and is not necessarily represented by the general formula (1). It does not indicate that the structural unit and the structural unit represented by the general formula (3) are alternately connected.

(2-2) Other (meth) acrylic resin Methacrylic modified bisphenol A type epoxy resin: BAEM-100 manufactured by KSM (methacryl modification rate 100%)
Urethane acrylic resin: AH-600 (phenylglycidyl ether acrylate hexamethylene diisocyanate urethane prepolymer) manufactured by Kyoeisha Chemical Co., Ltd.

(3) Photopolymerization initiator C
Oxime ester-based photopolymerization initiator: OXE-01 manufactured by BASF (1,2-octanedione, 1- [4- (phenylthio) -2- (O-benzoyl oxime)])

(4) Thermosetting agent D
Amine-based latent hardener:
SDH manufactured by Otsuka Chemical Co., Ltd. (sebacic acid dihydrazide, melting point 180 ° C)
2MA-OK manufactured by Shikoku Kasei Co., Ltd. ((2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-triazine) isocyanuric acid adduct)

(5) Filler E
Silica particles: KE-S100 manufactured by Nippon Shokubai Kagaku Co., Ltd., average particle diameter 1 μm
Thermoplastic resin particles: F351 manufactured by Aica Kogyo Co., Ltd., softening point 120 ° C., average particle diameter 0.3 μm

(6) Silane coupling agent H
γ-glycidoxypropyltrimethoxysilane: KBM-403 manufactured by Shinetsu Silicone Co., Ltd.

2. 2. Preparation and evaluation of sealing material for liquid crystal dropping method (Example 1)
80 parts by mass of bisphenol A epoxy acrylic modified product (manufactured by KSM, BAEM-50) as the partial (meth) acrylic resin A, and polybutadiene acrylic resin (TE-2000, manufactured by Nippon Soda) as the (meth) acrylic resin B. 20 parts by mass, 1 part by mass of an oxime ester-based photopolymerization initiator as the photopolymerization initiator C, 6 parts by mass of sebacic acid dihydrazide (SDH manufactured by Otsuka Chemical Co., Ltd.) as the heat curing agent D, and an imidazole-based latent curing agent. 1 part by mass of (2MA-OK manufactured by Shikoku Kasei Co., Ltd.), 5 parts by mass of silica particles (KE-S100 manufactured by Nippon Catalytic Chemical Co., Ltd.) as filler E, and thermoplastic resin particles F351 (manufactured by Aika Kogyo Co., Ltd.). Sufficient to make a uniform liquid using 5 parts by mass and 1 part by mass of γ-glycidoxypropyltrimethoxysilane (KBM-403 manufactured by Shinetsu Silicone Co., Ltd.) as the silane coupling agent H using a three-roll mill. To obtain a sealing material.

(Examples 2 to 4, Comparative Examples 1 to 3)
A sealing material was obtained in the same manner as in Example 1 except that the composition was changed to that shown in Table 1.

The viscosity stability of the obtained sealing material, the display characteristics of the liquid crystal display panel using the sealing material, and the adhesive strength were evaluated by the following methods.

[Viscosity stability]
10 g of a sealing material was put into a syringe for dispensing, and defoaming treatment was performed. The initial viscosity of 2 g of the sealing material after the de-method treatment was measured with an E-type viscometer under the conditions of 25 ° C. and 2.5 rpm. Further, after storing this sealing material at 23 ° C. and 50% RH for 1 week, the viscosity was measured in the same manner. Then, the viscosity stability was evaluated based on the following criteria.
◯: The ratio of viscosity after 1 week (rate of increase) to the initial viscosity is 1.2 times or less Δ: The ratio of viscosity after 1 week to the initial viscosity (rate of increase) exceeds 1.2 times, 1.5 times Double or less ×: The ratio (rate of increase) of viscosity after one week to the initial viscosity exceeds 1.5 times

[Display characteristics of liquid crystal display panel]
Using a dispenser ("Shot Master", manufactured by Musashi Engineering), apply a sealing material on a 40 mm x 45 mm glass substrate ("RT-DM88-PIN", manufactured by EHC) with a transparent electrode and an alignment film. A quadrangular frame-shaped seal pattern (line cross-sectional area: 3500 μm ² ) (main seal) of 35 mm × 40 mm was produced. Further, a sealing material was applied under the same conditions so as to surround the produced main seal.
Next, an amount of liquid crystal material (“MLC-11900-000”, manufactured by Merck & Co., Inc.) corresponding to the capacity of the panel after bonding was precisely dropped into the frame of the main seal using a dispenser. The glass substrate and the opposite glass substrate were overlapped under reduced pressure, and then opened under atmospheric pressure to be bonded. After holding the bonded glass substrate in a light-shielding box for 3 minutes, the main seal (seal material) was temporarily cured by irradiating it with ultraviolet rays of 3000 mJ / cm ² . Next, the main seal (seal material) was thermoset by heating at 120 ° C. for 60 minutes to obtain a liquid crystal display panel.
The obtained liquid crystal display panel was driven by an applied voltage of 5 V using a DC power supply device, and the presence or absence of color unevenness of the liquid crystal in the vicinity of the main seal (seal material) was visually observed. Then, the display characteristics of the liquid crystal display panel were evaluated based on the following criteria.
◯: The display function is exhibited up to the time of sealing, and no abnormality in the display function is observed. Δ: Abnormality in the display function is observed at a position within 0.3 mm at the time of sealing. Abnormal display function is observed

[Adhesive strength]
A liquid crystal display panel produced in the same procedure as the procedure described in the above "Display characteristics of the liquid crystal display panel" was stored under high temperature and high humidity conditions (70 ° C., 95% RH) for 500 hours. Then, the plane tensile strength (adhesive strength) of the two glass substrates of the liquid crystal display panel after being left under high temperature and high humidity conditions is measured using a tensile test device (manufactured by Intesco) under the condition of a tensile speed of 2 mm / min. did. Then, the adhesive strength was evaluated based on the following criteria.
◯: Adhesive strength is 20 MPa or more Δ: Adhesive strength is 15 MPa or more and less than 20 MPa ×: Adhesive strength is less than 15 MPa

The evaluation results of Examples 1 to 4 and Comparative Examples 1 to 3 are shown in Table 1.

As shown in Table 1, it can be seen that the sealing materials of Examples 1 to 4 all have good viscosity stability, display characteristics, and adhesive strength.

On the other hand, it can be seen that the sealing material of Comparative Example 1 has particularly low display characteristics. It is considered that this is because the acrylic-modified epoxy resin does not have a hydrogen-bonding functional group, so that the contamination of the liquid crystal material could not be suppressed. It can be seen that the sealing material of Comparative Example 2 has low adhesive strength as well as display characteristics. It is considered that this is because not only the flexibility of the acrylic-modified epoxy resin itself is low, but also the content ratio of the low-flexibility portion (meth) acrylic resin is high. It can be seen that the sealing material of Comparative Example 3 has low adhesive strength. It is considered that this is because the urethane acrylate is not sufficiently flexible.

INDUSTRIAL APPLICABILITY The present invention can provide a sealing material for a liquid crystal dropping method, which has high adhesive strength to a substrate of a liquid crystal display panel even when the sealing member is narrowed, and can suppress contamination of the liquid crystal.

Claims (7)

A portion (meth) acrylic-modified epoxy resin A having an epoxy group and a (meth) acryloyl group,
It has at least one of the structural unit represented by the following general formula (1) and the structural unit represented by the following general formula (2), and has a hydrogen-bonding functional group selected from the group consisting of a hydroxyl group and a carboxy group. (Meta) acrylic resin B and
Photopolymerization initiator C and
Thermosetting agent D and
The partial (meth) acrylic-modified epoxy resin A containing the filler E does not include the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2). ),
Sealing material for liquid crystal dripping method.

(R in formula (1) represents a hydrogen atom or a methyl group) The hydrogen-bonding functional group equivalent of the (meth) acrylic resin B is 500 to 8000 g / eq.
The sealing material for the liquid crystal dropping method according to claim 1 . The total content of the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) is 30 with respect to the total mass of the structural unit constituting the (meth) acrylic resin B. ~ 99% by mass,
The sealing material for the liquid crystal dropping method according to claim 1 or 2 . The content mass ratio B / A of the (meth) acrylic resin B and the partial (meth) acrylic-modified epoxy resin A is 0.1 to 0.5.
The sealing material for the liquid crystal dropping method according to any one of claims 1 to 3 . The thermosetting agent D is an amine-based latent curing agent or a thiol-based latent curing agent.
The sealing material for the liquid crystal dropping method according to any one of claims 1 to 4 . A step of forming a frame-shaped seal pattern on one of the substrates by using the seal material for the liquid crystal dropping method according to any one of claims 1 to 5 .
A step of dropping a liquid crystal into the frame of the seal pattern or on the other substrate paired with the one substrate in a state where the seal pattern is uncured.
A step of superimposing the one substrate and the other substrate via the seal pattern, and
A step of photo-curing the seal pattern and then heat-curing it,
including,
Manufacturing method of liquid crystal display panel. A pair of boards and
A frame-shaped sealing member arranged between the pair of substrates,
A liquid crystal layer filled in a space surrounded by the sealing member between the pair of substrates is included.
The sealing member is a cured product of the sealing material for the liquid crystal dropping method according to any one of claims 1 to 5 .
Liquid crystal display panel.