KR20120125552A - Liquid crystal sealing agent, method for producing liquid crystal display panel using same, and liquid crystal display panel - Google Patents

Abstract

An object of the present invention is to provide a liquid crystal sealing agent which is excellent in display reliability without changing display characteristics even under high temperature and high humidity conditions. The liquid crystal sealing agent of this invention contains the (meth) acryl modified epoxy resin obtained by making the epoxy resin containing two or more epoxy groups and (meth) acrylic acid react in a molecule | numerator, a hardening | curing agent, and a photoinitiator, The said (meth) An acrylic modified epoxy resin contains the hydroxyl group produced by reaction of the epoxy resin containing 2 or more epoxy groups in the said molecule | numerator, and the said (meth) acrylic acid, and also the (meth) acryl group of the said (meth) acryl modified epoxy resin The equivalent / epoxy group equivalent is more than 9, and the hydrogen bondable functional group containing the hydroxyl group is 3 × 10 ⁻³ to 5 × 10 ⁻³ mol / g.

Description

Liquid crystal sealing agent, the manufacturing method of the liquid crystal display panel using the same, and a liquid crystal display panel {LIQUID CRYSTAL SEALING AGENT, METHOD FOR PRODUCING LIQUID CRYSTAL DISPLAY PANEL USING SAME, AND LIQUID CRYSTAL DISPLAY PANEL}

This invention relates to a liquid crystal sealing agent, the manufacturing method of the liquid crystal display panel using the same, and a liquid crystal display panel.

Background Art In recent years, liquid crystal display panels have been widely used as image display panels of various electronic devices including mobile phones and personal computers. The liquid crystal display panel is an image display panel having a structure in which a liquid crystal material (hereinafter simply referred to as "liquid crystal") is sandwiched between two transparent substrates provided with electrodes on a surface thereof, and the circumference thereof is sealed by a liquid crystal sealing agent. .

The amount of the liquid crystal sealing agent is slightly used, but since it is in direct contact with the liquid crystal, it greatly affects the reliability of the liquid crystal display panel. Therefore, in order to realize the high quality of a liquid crystal display panel, a high and various characteristic is currently required for liquid crystal sealing agent.

Conventionally, liquid crystal display panels are mainly manufactured by the liquid crystal injection method. In general, the liquid crystal injection method (1) forms a mold by applying a liquid crystal sealing agent on one transparent substrate, and (2) after drying the liquid crystal sealing agent by precuring the substrate, the other substrate. (3) by heating and pressing the two substrates, and bonding the substrates together to form a frame (cell) of liquid crystal sealing agent between the substrates, and (4) injecting an appropriate amount of liquid crystal into the empty cell. Then, it is a method of manufacturing a liquid crystal display panel by sealing the injection hole of a liquid crystal.

On the other hand, in recent years, the liquid crystal dropping method is examined as a manufacturing method of the liquid crystal display panel in which productivity improvement is anticipated. In the liquid crystal dropping method, (1) a liquid crystal sealing agent is applied on a transparent substrate to form a frame for filling a liquid crystal, (2) a fine liquid crystal is dropped into the frame, and (3) the liquid crystal sealing agent is in an uncured state. After laminating | stacking two board | substrates under high vacuum as it is, (4) it is a method of hardening liquid crystal sealing agent and manufacturing a panel. Usually, in the liquid-crystal dropping method, using light and a thermosetting liquid crystal sealing agent, in the process of said (3), after performing temporary hardening which irradiates liquid crystal sealing agent light, such as an ultraviolet-ray, by heating Post-cure is performed.

As liquid crystal sealing agent for liquid crystal dropping methods, using liquid epoxy resin is proposed, for example (patent document 1). However, this epoxy resin has solubility in liquid crystals even at normal temperature, which is a factor of lowering display characteristics of the liquid crystal display panel.

On the other hand, liquid crystal sealing agent (for example, patent document 2) using crystalline epoxy resins, such as an ether type epoxy resin, as resin which is hard to melt | dissolve in a liquid crystal; Liquid crystal sealing agent (for example, patent document 3) containing acrylic acid-modified phenol novolak epoxy resin, and urethane-modified partially acrylic modified substance is proposed.

Japanese Patent No. 3955038 Japanese Patent Publication No. 2005-018022 Japanese Patent Publication No. 2006-124698

The resin of patent documents 2 and 3 has some low solubility with respect to a liquid crystal at room temperature in any one. However, in high temperature and high humidity conditions, since resin became easy to melt | dissolve into a liquid crystal, there existed a possibility that the display characteristic of a liquid crystal display panel might fall. In particular, in the liquid crystal dropping method, since the uncured liquid crystal sealing agent is in contact with the liquid crystal, the components of the liquid crystal sealing agent are easily dissolved in the liquid crystal, and are likely to cause deterioration of the display characteristics of the liquid crystal display panel.

This invention is made | formed in view of the said situation, and an object of this invention is to provide the liquid crystal sealing agent which is excellent in display reliability, without changing a display characteristic also in high temperature and high humidity conditions.

As mentioned above, in order not to reduce the display characteristic of a liquid crystal display panel, it becomes important to suppress melt | dissolution to the liquid crystal of a liquid crystal sealing agent. Although melt | dissolution to the liquid crystal of resin can be suppressed to some extent by making it into crystalline resin, in particular, since resin is easy to melt | dissolve under high temperature, it may melt | dissolve in a liquid crystal. Moreover, since the viscosity of a conventional liquid crystal sealing agent which suppressed melt | dissolution to a liquid crystal tends to become high, there also existed a problem that applicability | paintability and workability were low.

On the other hand, the present inventors react a part of the epoxy group of an epoxy resin with (meth) acrylic acid, and introduce | transduce the hydroxyl group (low compatibility with a liquid crystal) to resin, and melt | dissolves the resin in the liquid crystal. Focused on how to suppress. And it discovered that not only the absolute number of hydroxyl groups contained in resin but the ratio (balance) of the number of hydroxyl groups with respect to the number of unreacted epoxy groups greatly affected the solubility with respect to the liquid crystal of resin. Namely, increasing the ratio of the number of hydroxyl groups to the number of unreacted epoxy groups; Specifically, it was found that dissolution in the liquid crystal can be suppressed by setting the range of the hydrogen-bonding functional group to a certain range and by setting the (meth) acryl group equivalent / epoxy group equivalent to a predetermined value or more. This invention is made | formed based on this knowledge.

The first of the present invention relates to a liquid crystal sealing agent.

[1] a (meth) acryl-modified epoxy resin obtained by reacting an epoxy resin containing two or more epoxy groups in a molecule with (meth) acrylic acid; Thermal curing agents; A photopolymerization initiator, wherein the (meth) acryl-modified epoxy resin includes a hydrogen bond functional group containing a hydroxyl group produced by the reaction of an epoxy resin containing two or more epoxy groups in the molecule and the (meth) acrylic acid. In addition, the (meth) acryl group equivalent / epoxy group equivalent of the said (meth) acryl modified epoxy resin is more than 9, and the said hydrogen bond functional group is 3 * 10 <^{-3> -5} * 10 <^-3> mol / g liquid crystal sealing agent.

[2] The liquid crystal sealing agent according to [1], wherein the epoxy resin containing two or more epoxy groups in the molecule is a bifunctional epoxy resin selected from the group consisting of a biphenyl type epoxy resin, a naphthalene type epoxy resin and a bisphenol type epoxy resin. .

[3] The liquid crystal sealing agent according to [2], wherein the bifunctional epoxy resin is a bisphenol A type epoxy resin or a bisphenol F type epoxy resin.

[4] The liquid crystal sealing agent according to any one of [1] to [3], further comprising 1 to 20 parts by weight of a solid epoxy resin having a softening point of 40 ° C. or more and 150 ° C. or less with respect to 100 parts by weight of the liquid crystal sealing agent.

[5] The compound according to any one of [1] to [4], wherein the photopolymerization initiator is selected from the group consisting of alkylphenone compounds, acylphosphine oxide compounds, titanocene compounds, and oxime ester compounds. Liquid crystal sealing agent which is a compound more than a species.

[6] The liquid crystal sealing agent according to any one of [1] to [5], wherein the thermosetting agent has a melting point of 50 ° C or more and 250 ° C or less.

[7] The liquid crystal sealing agent according to any one of [1] to [6], which is at least one member selected from the group consisting of organic acid dihydrazide compounds, imidazole compounds, dicyandiamide compounds, and polyamine compounds. .

[8] The liquid crystal sealing agent according to any one of [1] to [7], which is used for production of a liquid crystal display panel by a liquid crystal dropping method.

2nd of this invention relates to the manufacturing method of a liquid crystal display panel using liquid crystal sealing agent, etc.

[9] A step of forming a seal pattern on one substrate using the liquid crystal sealing agent according to any one of [1] to [8], and the seal of the one substrate in a state where the seal pattern is uncured. A process of dropping a liquid crystal onto the other substrate in the pattern region or corresponding to the one substrate, the step of overlapping the one substrate with the other substrate, and thermal curing after photocuring the seal pattern The manufacturing method of the liquid crystal display panel containing the process to make it.

[10] a display substrate, an opposing substrate corresponding to the display substrate, a frame-shaped sealing member interposed between the display substrate and the opposing substrate, and the seal member between the display substrate and the opposing substrate. A liquid crystal display panel comprising a liquid crystal layer filled in a space, wherein the sealing member is a cured product of the liquid crystal sealing agent according to any one of [1] to [8].

According to this invention, the liquid crystal sealing agent excellent in display reliability can be provided.

1. Liquid crystal sealing agent

The liquid crystal sealing agent of this invention contains (A-1) (meth) acryl modified epoxy resin, (B) thermosetting agent, and (C) photoinitiator, (A-2) solid epoxy resin, (D) as needed ) Acrylic resin, (E) filler, etc. may further be included.

(A) epoxy resin

(A-1) (meth) acrylic modified epoxy resin

The (meth) acryl modified epoxy resin in the present invention is preferably a (meth) acryl modified epoxy resin obtained by reacting an epoxy resin and (meth) acrylic acid in the presence of a basic catalyst, for example.

The epoxy resin which becomes a raw material should just be a bifunctional or more epoxy resin which has two or more epoxy groups in a molecule | numerator, and is bisphenol A type, bisphenol F type, 2,2'- diallyl bisphenol A type, bisphenol AD type, hydrogenated bisphenol type, etc. Bisphenol type epoxy resins; Novolak-type epoxy resins such as phenol novolak type, cresol novolak type, biphenyl novolak type, and trisphenol novolak type; Biphenyl type epoxy resins; Naphthalene type epoxy resin etc. are contained. Since the (meth) acryl modified epoxy resin obtained by (meth) acryl modification of polyfunctional epoxy resins, such as a trifunctional and tetrafunctional, is high in crosslinking density and adhesive strength falls easily, a bifunctional epoxy resin is preferable.

The bifunctional epoxy resin is preferably a biphenyl type epoxy resin, a naphthalene type epoxy resin and a bisphenol type epoxy resin, and in particular, bisphenol type epoxy resins such as bisphenol A type and bisphenol F type are preferable from the viewpoint of production efficiency. It is because a bisphenol-type epoxy resin has the advantage of being excellent in applicability | paintability compared with epoxy resins, such as a biphenyl ether type.

One type of epoxy resin used as a raw material may be sufficient as it, and a combination of two or more types may be sufficient as it. Moreover, it is preferable that the epoxy resin used as a raw material is highly purified by the molecular distillation method, the washing method, etc.

It is preferable to perform reaction of the epoxy resin used as a raw material and (meth) acrylic acid so that the (meth) acryl group equivalent / epoxy group equivalent of the (meth) acryl modified epoxy resin obtained may become a predetermined range.

That is, it is preferable to perform reaction of the epoxy resin used as a raw material and (meth) acrylic acid so that the (meth) acryl group equivalent / epoxy group equivalent of the (meth) acrylic modified epoxy resin obtained may be more than 9, and it is more preferable to carry out so that it may be 9.5 or more. desirable. In the present invention, the (meth) acrylic group equivalent in the (meth) acrylic modified epoxy resin is "the average number of (meth) acryl groups contained in one molecule of the (meth) acryl modified epoxy resin / (meth) acryl modified epoxy Weight average molecular weight (Mw) of the resin &quot;. Similarly, the epoxy group equivalent in a (meth) acrylic modified epoxy resin is "weight average molecular weight (Mw) of the average number of epoxy groups / (meth) acryl modified epoxy resin contained in 1 molecule of (meth) acryl modified epoxy resin" ". Is displayed. That is, the (meth) acryl group equivalent / epoxy group equivalent is the same as the average number of (meth) acryl groups / epoxy group.

The (meth) acryl-modified epoxy resin having a (meth) acryl group equivalent / epoxy group equivalent of less than 9 has a small ratio of the number of hydroxyl groups (produced in the reaction) to the number of unreacted epoxy groups; Or since the ratio of the reactant (epoxy resin containing a hydroxyl group) is small with respect to an unreacted substance (epoxy resin not containing a hydroxyl group), the effect which suppresses melt | dissolution to a liquid crystal material becomes difficult to be acquired.

This is specifically explained in the example where the epoxy resin as a raw material is a bifunctional epoxy resin. When the bifunctional epoxy resin is reacted with (meth) acrylic acid, 1) unreacted material in which both epoxy groups remain unreacted, and 2) one Three kinds of partial (meth) acrylates in which the epoxy group in is modified with (meth) acrylic acid and all (meth) acrylates in which both of the two epoxy groups are modified with (meth) acrylic acid are produced. Then, when the difunctional epoxy resin and the (meth) acrylic acid are reacted so that the number of the (meth) acryl groups / the number of the epoxy groups is 1, the production rate of 1) unreacted material having a significant dissolution in the liquid crystal remains about 25 mol%. It is confirmed. On the other hand, when the number of (meth) acrylic groups is reacted so that the number of epoxy groups is more than 9, the ratio of 1) unreacted substance with remarkable dissolution to the liquid crystal can be reduced to 2 mol% or less, so that dissolution to the liquid crystal is prevented. It can be significantly suppressed.

In particular, the (meth) acryl-modified epoxy resin used in the present invention preferably has a relatively flexible skeleton and may have low crystallinity. The sealing compound containing such a (meth) acryl modified epoxy resin becomes relatively low viscosity, and becomes easy to melt | dissolve in a liquid crystal. By setting the ratio of the (meth) acrylic group equivalent / epoxy group equivalent to more than 9, even with such a low viscosity (meth) acrylic-modified epoxy resin, it may be difficult to dissolve the liquid crystal.

The weight average molecular weight of such a (meth) acryl modified epoxy resin may be about 310-500, for example. The weight average molecular weight Mw of a (meth) acryl modified epoxy resin can be measured, for example by gel permeation chromatography (GPC).

On the other hand, when the ratio of the (meth) acrylic group equivalent / epoxy group equivalent is too large exceeding 9, since the hydroxyl group generated by the addition reaction of (meth) acrylic acid increases, the moisture resistance of the cured product may decrease. For this reason, it is preferable to set the upper limit of the ratio of (meth) acryl group equivalent / epoxy group equivalent to the grade which does not significantly impair moisture resistance. Or as mentioned later, (A-2) use a solid epoxy resin with a softening point of 40-150 degreeC together; (B) As a thermosetting agent, moisture resistance can also be maintained by using a thermosetting agent of a high melting point together.

In addition, when the ratio of the (meth) acrylic group equivalent / epoxy group equivalent is less than 9, the (meth) acryl-modified epoxy resin has low photocurability because the content ratio of the (meth) acryl group is small. Therefore, temporary hardening by the light of a liquid crystal sealing agent is easy to become inadequate, and it may be difficult to suppress elution to a liquid crystal.

The (meth) acryl modified epoxy resin has hydrogen bond functional groups, such as a hydroxyl group, a urethane bond, an amide group, and a carboxyl group. Examples of such hydrogen bondable functional groups include, but are not limited to, hydroxyl groups produced by reacting at least the epoxy group of the epoxy resin with (meth) acrylic acid, but are (meth) acrylic acid and epoxy serving as raw materials for the (meth) acrylic modified epoxy resin. The hydroxyl group, urethane bond, carboxyl group, and amide group contained in the resin are also included. Since the resin having a hydrogen bond functional group has low compatibility with the hydrophobic liquid crystal material, dissolution in the liquid crystal material is suppressed.

The hydrogen-bonding functional group of the (meth) acrylic modified epoxy resin is preferably 3 × 10 ⁻³ to 5 × 10 ⁻³ mol / g, and preferably 3.5 × 10 ⁻³ to 4.5 × 10 ⁻³ mol / g It is more preferable that is. When the hydrogen-bonding functional group is less than 3 × 10 ^-3 mol / g, since the number of hydrogen-bonding functional groups contained in one molecule of (meth) acryl-modified epoxy resin is small, it is difficult to obtain the effect of suppressing dissolution in liquid crystals. It is because moisture resistance of the hardened | cured material of a (meth) acryl modified epoxy resin will fall easily when it exceeds 5 * 10 <^-3> mol / g.

The hydrogen bond functional group (mol / g) of a (meth) acryl modified epoxy resin is "the number of hydrogen bond functional groups contained in 1 molecule of (meth) acryl modified epoxy resin" / "(meth) acryl modified epoxy resin Weight average molecular weight (Mw) &quot;. For example, as the hydrogen bondable functional group, the number of moles of (meth) acrylic acid reacted with the hydrogen bondable functional group of the (meth) acrylic modified epoxy resin having only a hydroxyl group obtained by reacting (meth) acrylic acid with an epoxy resin is (meth) acrylic acid. It can obtain | require by dividing by the weight average molecular weight (Mw) of a modified epoxy resin.

The hydrogen-bonding functional group of the (meth) acryl-modified epoxy resin is, for example, adjusting the number of moles of (meth) acrylic acid to react with the epoxy resin as a raw material; It can control by adjusting the quantity of the hydrogen bondable functional group which the (meth) acrylic acid and epoxy resin which become a raw material have.

It is preferable that the hydroxyl group of the (meth) acryl modified epoxy resin obtained by making an epoxy resin and (meth) acrylic acid react as a raw material is 3 * 10 <^{-3> -5} * 10 <^-3> mol / g.

It is preferable that it is 10-70 mass parts with respect to 100 mass parts of liquid crystal sealing agents, and, as for content of a (meth) acryl modified epoxy resin, it is more preferable that it is 20-50 mass parts.

As described above, the (meth) acryl-modified epoxy resin has an epoxy group and a (meth) acryl group in its molecule, and therefore, may have both photocurability and thermal curability. Moreover, even if a (meth) acryl modified epoxy resin is an amorphous epoxy resin, since the ratio of the number of hydroxyl groups with respect to the number of epoxy groups is high, melt | dissolution to a liquid crystal can be highly suppressed.

(A-2) solid epoxy resin

The liquid crystal sealing agent of this invention may contain the solid epoxy resin whose softening point is 40 degreeC or more and 150 degrees C or less as needed. Such a solid epoxy resin is low in solubility and diffusibility with respect to liquid crystal, and the display characteristic of the liquid crystal panel obtained is favorable, and can improve the moisture resistance of hardened | cured material.

Such a solid epoxy resin may be an aromatic epoxy resin having a weight average molecular weight of 500 to 10000, preferably 1000 to 5000. The weight average molecular weight of a solid epoxy resin can be measured as mentioned above.

Examples of such aromatic epoxy resins include aromatic diols represented by bisphenol A, bisphenol S, bisphenol F, bisphenol AD and the like, and diols obtained by modifying them with ethylene glycol, propylene glycol and alkylene glycol, and epichloro Aromatic polyhydric glycidyl ether compounds obtained by the reaction of hydrin; Novolak-type polyhydric glycidyl ether compounds obtained by reaction of the phenol or cresol, polyphenols represented by novolak resin derived from formaldehyde, polyalkenylphenol, its copolymer, etc., and epichlorohydrin; Glycidyl ether compounds of xylylene phenol resins; and the like.

The said aromatic epoxy resin is a cresol novolak-type epoxy resin, a phenol novolak-type epoxy resin, a bisphenol-A epoxy resin, a bisphenol F-type epoxy resin, a triphenol methane type epoxy resin, a triphenolethane type epoxy resin, and a tris especially, Phenol type epoxy resins, dicyclopentadiene type epoxy resins, diphenyl ether type epoxy resins, and biphenyl type epoxy resins are preferable. In addition, these can be mixed and used.

It is preferable that it is 1-20 mass parts with respect to 100 mass parts of liquid crystal sealing agents, and, as for content of solid epoxy resin, it is more preferable that it is 3-10 mass parts. When there is too much content of solid epoxy resin, the viscosity of a liquid crystal sealing agent may become high and applicability | paintability may fall, and when there is too little content of solid epoxy resin, the moisture resistance of the hardened | cured material of a liquid crystal sealing agent may become inadequate. .

(A-1) The mass ratio ((meth) acrylic modified epoxy resin / solid epoxy resin) of the (meth) acrylic modified epoxy resin and the (A-2) solid epoxy resin is the viscosity stability of the liquid crystal sealing agent and the moisture resistance of the cured product. It is good to adjust from a viewpoint to make it compatible. When the said mass ratio is too large, since there is little content of a solid epoxy resin, the moisture resistance of the hardened | cured material of liquid crystal sealing agent may become inadequate, and when the said mass ratio is too small, since content of solid epoxy resin is large, a viscosity will become high, Application property may fall.

(B) thermal curing agent

Although the thermosetting agent is mixed with an epoxy resin, although it does not harden an epoxy resin in the state which normally stores resin (room temperature, visible light, etc.), it is a hardening agent which hardens an epoxy resin when heat is applied. Liquid crystal sealing agent containing a thermosetting agent is excellent in storage stability, and also excellent in thermosetting. Although the thermosetting agent used for this invention may be well-known, from the viewpoint of improving the viscosity stability of liquid crystal sealing agent, and maintaining moisture resistance, it also depends on the thermosetting temperature, but the melting | fusing point heat is 50 degreeC or more and 250 degrees C or less. A hardening | curing agent is preferable, The thermosetting agent whose melting | fusing point is 100 degreeC or more and 200 degrees C or less is more preferable, The thermosetting agent whose melting | fusing point is 150 degreeC or more and 200 degrees C or less is more preferable.

Preferred examples of such a thermosetting agent include organic acid dihydrazide compounds, imidazole compounds, dicyandiamide compounds, polyamine compounds, and the like.

Examples of the organic acid dihydrazide-based compound include adipic acid dihydrazide (melting point 181 ° C), 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin (melting point 120 ° C), 7 , 11-octadecadiene-1,18-dicarbohydrazide (melting point 160 ° C), dodecane diacid dihydrazide (melting point 190 ° C), sebacic acid dihydrazide (melting point 189 ° C), and the like. Included. Examples of the imidazole compound include 2,4-diamino-6- [2'-ethylimidazolyl- (1 ')]-ethyltriazine (melting point 215 to 225 ° C) and 2-phenylimidazole ( Melting point 137-147 degreeC) etc. are included. Examples of dicyandiamide-based compounds include dicyandiamide (melting point 209 ° C) and the like. A polyamine type compound is a thermal latent hardening | curing agent which has a polymer structure obtained by making an amine and an epoxy react, and the specific example is Adeka hardener EH4339S (softening point 120-130 degreeC) by ADEKA Co., Ltd., and Adeka by ADEKA Co., Ltd. Hardener EH4357S (softening point 73-83 degreeC), etc. are included. These may be used independently and may be used in combination of multiple.

It is preferable that the addition amount of a thermosetting agent is adjusted so that active hydrogen equivalent may be 0.8-1.2 equivalent with respect to epoxy equivalent. Liquid crystal sealing agent containing a thermosetting agent can be what is called a 1-liquid curable resin composition. Since a one-liquid curable resin composition does not need to mix a main agent and a hardening | curing agent in use, it is excellent in workability.

(C) photoinitiator

A photoinitiator is an initiator for photocuring-reacting (A-1) (meth) acryl modified epoxy resin, (D) acrylic resin mentioned later, etc. When liquid crystal sealing agent contains a photoinitiator, the temporary hardening of the sealing compound by photocuring at the time of manufacturing a liquid crystal panel becomes possible, and a working process becomes easy.

As a photoinitiator, a well-known thing can be used. Examples include alkylphenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin compounds, acetophenone compounds, benzophenone compounds, thioxanthone compounds, and α-acyl oxime esters. Compounds, phenylglyoxylate compounds, benzyl compounds, azo compounds, diphenylsulfide compounds, organic pigment compounds, iron-phthalocyanine compounds, benzoin ether compounds, anthraquinone compounds, and the like. Include.

Examples of the alkylphenone compound include benzyl dimethyl ketal such as 2,2-dimethoxy-1,2-diphenylethan-1-one (IRGACURE 651); Α-aminoalkylphenones such as 2-methyl-2-morpholino (4-thiomethylphenyl) prop-1-one (IIRGACURE 907); Α-hydroxyalkylphenones such as 1-hydroxycyclohexyl-phenyl-ketone (IRGACURE 184) and the like. Examples of the acylphosphine oxide-based compound include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and the like. Titanocene-based compounds include bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole-1-yl) -phenyl) titanium Included. Examples of the oxime ester compound include 1.2-octenane ion-1- [4- (phenylthio) -2- (0-benzoyloxime)] (IRGACURE OXE 01) and the like.

Content of a photoinitiator is the sum total of (A-1) (meth) acryl modified epoxy resin, (A-2) solid epoxy resin, (B) thermosetting agent, and (D) acrylic resin mentioned later (hereinafter "resin unit"). It is 0.3-5.0 mass parts with respect to 100 mass parts. By making said content into 0.3 mass part or more, sclerosis | hardenability by light irradiation of a liquid crystal sealing agent becomes favorable, and when it is 5.0 mass parts or less, stability at the time of application | coating to a board | substrate becomes favorable.

(D) acrylic resin

The liquid crystal sealing agent of this invention may contain acrylic resin as needed. Examples of the acrylic resin include diacrylates and / or dimethacrylates such as polyethylene glycol, propylene glycol, and polypropylene glycol; Diacrylates and / or dimethacrylates of tris (2-hydroxyethyl) isocyanurate; Diacrylates and / or dimethacrylates of diols obtained by adding 4 moles or more of ethylene oxide or propylene oxide to 1 mole of neopentyl glycol; Diacrylate and / or dimethacrylate of diol obtained by adding 2 mol of ethylene oxide or propylene oxide to 1 mol of bisphenol A; Di or triacrylate and / or di or trimethacrylate of triols obtained by adding 3 moles or more of ethylene oxide or propylene oxide to 1 mole of trimethylolpropane; Diacrylates and / or dimethacrylates of diols obtained by adding 4 moles or more of ethylene oxide or propylene oxide to 1 mole of bisphenol A; Tris (2-hydroxyethyl) isocyanurate triacrylate and / or trimethacrylate; Trimethylolpropane triacrylate and / or trimethacrylate, or oligomers thereof; Pentaerythritol triacrylate and / or trimethacrylate, or oligomers thereof; Polyacrylates and / or polymethacrylates of dipentaerythritol; Tris (acryloxyethyl) isocyanurate; Caprolactone modified tris (acryloxyethyl) isocyanurate; Caprolactone modified tris (methacryloxyethyl) isocyanurate; Polyacrylates and / or polymethacrylates of alkyl modified dipentaerythritol; Polyacrylates and / or polymethacrylates of caprolactone modified dipentaerythritol; Hydroxypivarine neopentylglycol diacrylate and / or dimethacrylate; Caprolactone modified hydroxypivarine neopentylglycol diacrylate and / or dimethacrylate; Ethylene oxide modified phosphate acrylate and / or dimethacrylate; Ethylene oxide modified alkylated phosphate acrylates and / or dimethacrylates; Neopentylglucol, trimethylolpropane, oligoacrylates and / or oligomethacrylates of pentaerythritol, and the like.

Although content of an acrylic resin depends also on the grade of photocurability required, it is preferable that it is 5-40 mass parts with respect to 100 mass parts of liquid crystal sealing agents, and it is more preferable that it is 10-30 mass parts.

(E) filler

The liquid crystal sealing agent of this invention may contain the filler further. By addition of a filler, control of the viscosity of a liquid crystal sealing agent, the intensity | strength of hardened | cured material, linear expandability, etc. can be performed.

The filler is not particularly limited, but examples thereof include calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum silicate, zirconium silicate, iron oxide, titanium oxide, aluminum oxide (alumina), zinc oxide, silicon dioxide, potassium titanate Inorganic fillers such as kaolin, talc, glass beads, sericite activated clay, bentonite, aluminum nitride, silicon nitride, and the like, and preferably silicon dioxide and talc.

The shape of the filler is not particularly limited, and may be any of a regular shape or an amorphous shape such as spherical shape, plate shape, and needle shape. It is preferable that an average primary particle diameter is 1.5 micrometers or less, and, as for a filler, it is preferable that the specific surface area is 0.5m <^2> / g-20m <^2> / g. The average primary particle diameter of a filler can be measured by the laser diffraction method described in JIS Z8825-1. In addition, a specific surface area measurement can be measured by the BET method as described in JIS Z8830.

The filling amount of the filler is a total of (A-1) (meth) acryl modified epoxy resin, (A-2) solid epoxy resin, (B) thermosetting agent and (D) acrylic resin (hereinafter also referred to as "resin unit") 100 It is preferable that it is 1-50 mass parts with respect to a mass part, and it is more preferable that it is 10-30 mass parts.

(F) thermoplastic resin particles

The liquid crystal sealing agent of this invention may also contain the thermoplastic resin particle (it calls it "epoxy modified particle | grains") modified with the epoxy resin as needed. The thermoplastic resin particles are obtained by suspension polymerization of a resin containing an epoxy group and a double bond group with a monomer capable of radical polymerization. It is preferable to add a thermoplastic resin particle when it is set as the liquid crystal sealing compound for liquid crystal injection systems. This is because the shrinkage stress generated in the cured product can be alleviated by heating.

Examples of the resin containing an epoxy group and a double bond group include a resin obtained by reacting a bisphenol F-type epoxy resin with methacrylic acid in the presence of a tertiary amine. Examples of the monomer capable of radical polymerization include butyl acrylate, glycidyl methacrylate and divinylbenzene. Since the average particle diameter of a thermoplastic resin particle is 5 micrometers or less in the gap of a liquid crystal cell, since it is mainstream, it is more preferable that it is usually 0.05-5 micrometers, Preferably it is the range of 0.07-3 micrometers.

It is preferable that a thermoplastic resin particle is 1-30 mass parts with respect to 100 mass parts of resin units.

(G) other additives

The liquid crystal sealing agent of this invention further contains additives, such as coupling agents, such as a thermal radical polymerization initiator and a silane coupling agent, an ion trap agent, an ion exchange agent, a leveling agent, a pigment, dye, a plasticizer, an antifoamer, etc. You may do it. Moreover, a spacer etc. can also be mix | blended in order to adjust the gap of a liquid crystal panel.

Since the liquid crystal sealing agent of this invention contains the (A-1) (meth) acryl modified epoxy resin, (B) thermosetting agent, and (C) photoinitiator, the liquid crystal which often uses together photocuring and thermosetting. It is used preferably for the liquid crystal sealing agent for dripping methods. The liquid crystal sealing agent for liquid crystal dropping methods, Preferably, they further contain (A-2) solid epoxy resin and (D) acrylic resin, More preferably, it further contains (E) filler.

It is preferable that the viscosity in 25 degreeC and 2.5 rpm using the E-type viscosity meter of the liquid crystal sealing agent of this invention is 30-350 Pa.s. It is because the liquid crystal sealing agent whose viscosity is in the said range is excellent in applicability | paintability.

2. Manufacturing Method of Liquid Crystal Display Panel

The liquid crystal display panel of the present invention is filled in a space surrounded by a display substrate, a counter substrate corresponding thereto, a frame-shaped seal member interposed between the display substrate and the counter substrate, and a seal member between the display substrate and the counter substrate. A liquid crystal layer. The hardened | cured material of the liquid crystal sealing agent of this invention can be used as a sealing member.

Both the display substrate and the opposing substrate are transparent substrates. The material of the transparent substrate may be glass or plastic such as polycarbonate, polyethylene terephthalate, polyether sulfone and PMMA.

On the surface of the display substrate or the counter substrate, a matrix TFT, a color filter, a black matrix, or the like may be disposed. The alignment film is further formed on the surface of the display substrate or the counter substrate. A well-known organic aligning agent, an inorganic aligning agent, etc. are contained in an oriented film.

Such a liquid crystal display panel can be manufactured using the liquid crystal sealing agent of this invention. There exist a liquid crystal dropping method and a liquid crystal injection method in the manufacturing method of a liquid crystal display panel.

The manufacturing method of the liquid crystal display panel by the liquid crystal dropping method is

a1) the 1st process of forming the sealing pattern of the liquid crystal sealing agent of this invention on one board | substrate,

a2) a second step of dropping the liquid crystal into a region surrounded by the seal pattern of the substrate or a region of the other substrate facing the region surrounded by the seal pattern in a state where the seal pattern is uncured;

a3) a third step of overlapping one substrate and the other substrate through a seal pattern;

a4) a fourth step of curing the seal pattern.

The state in which the seal pattern was uncured at the process of a2) means the state which hardening reaction of a liquid crystal sealing agent does not progress to a gelation point. For this reason, in the process of a2), in order to suppress melt | dissolution to the liquid crystal of a liquid crystal sealing agent, you may make it semi-harden by irradiating or heating a sealing pattern. One board | substrate and the other board | substrate are a display board | substrate or an opposing board | substrate, respectively.

Although the hardening by heating may be performed at the process of a4), it is preferable to perform hardening (main hardening) by heating after hardening (temporary hardening) by light irradiation. This is because dissolution to the liquid crystal can be suppressed by temporarily curing the liquid crystal sealing agent by temporary curing by light irradiation.

Although photocuring time also depends on the composition of liquid crystal sealing agent, it is about 10 minutes, for example. Light irradiation energy should just be energy of the grade which can harden (A-1) a (meth) acryl modified epoxy resin, (D) acrylic resin, etc. The light is preferably ultraviolet light. Although the thermosetting temperature depends also on the composition of liquid crystal sealing agent, it is 120 degreeC, for example, and a thermosetting time is about 2 hours.

In the liquid crystal dropping method, since the contact time of an uncured liquid crystal sealing agent and a liquid crystal is comparatively long, liquid crystal contamination is easy to generate | occur | produce. On the other hand, since the liquid crystal sealing agent of this invention has low solubility with respect to a liquid crystal, the liquid crystal display panel obtained by the liquid crystal dropping method using the liquid crystal sealing agent of this invention is excellent in display reliability.

The manufacturing method of the liquid crystal display panel by a liquid crystal injection method is

b1) the 1st process of forming the sealing pattern of the liquid crystal sealing agent of this invention on one board | substrate,

b2) a second step of overlapping one substrate and the other substrate through a seal pattern;

b3) a third step of thermally curing the seal pattern to obtain a cell for liquid crystal injection having an injection hole for injecting liquid crystal;

b4) a fourth step of injecting the liquid crystal into the liquid crystal injection cell through the injection hole;

b5) a fifth step of sealing the injection hole.

In the process of b1)-b3), the cell for liquid crystal injection is prepared. First, two sheets of transparent substrates (eg, glass plates) are prepared. And a sealing pattern is formed in one board | substrate with a liquid crystal sealing agent. What is necessary is just to harden a seal pattern after the other board | substrate is superposed on the surface in which the seal pattern of the board | substrate was formed. At this time, it is necessary to provide an injection hole for injecting liquid crystal into a part of the cell for liquid crystal injection, but the injection hole may be provided with an opening in part when drawing the seal pattern. In addition, after forming a seal pattern, you may remove a seal pattern of a desired location and provide an injection hole.

Although the thermosetting conditions in the process of b3) also depend on the composition of liquid crystal sealing agent, it is about 2 to 5 hours at 150 degreeC, for example.

The process of b4) may be carried out in accordance with a known method of sucking the liquid crystal from the inlet of the liquid crystal injection cell by making the inside of the liquid crystal injection cell obtained in the steps b1) to b3 into a vacuum state. In the process of b5), you may harden after sealing a liquid crystal sealing agent in the injection port of the cell for liquid crystal injection.

In the liquid crystal injection method, the time that the uncured liquid crystal sealing agent and the liquid crystal come into contact with is relatively short. However, liquid crystal may be injected even if hardening of the liquid crystal sealing compound of the cell for liquid crystal injection does not advance enough. Since the liquid crystal sealing agent of this invention has low solubility with respect to a liquid crystal, it is hard to contaminate a liquid crystal even in such a case. Therefore, the liquid crystal display panel excellent in display reliability can also be obtained by the liquid crystal injection method using the liquid crystal sealing agent of this invention.

Example

Synthesis Example 1

Synthesis of Methacrylic Acid Modified Bisphenol F-type Epoxy Resin (95% Partial Methacrylate)

160 g of liquid bisphenol F type epoxy resin (epothode YDF-8170C, epoxy equivalent of Doto Chemical Co., Ltd. 160 g / eq), 0.1 g of p-methoxyphenol as polymerization inhibitor, 0.2 g of triethanolamine as catalyst and 81.7 g of catalyst Methacrylic acid was added into the flask, and dry air was blown to react for 5 hours with stirring under reflux at 90 ° C. The obtained compound was washed 20 times with ultrapure water to obtain methacrylic acid-modified bisphenol F type epoxy resin.

Here, the number of epoxy groups contained in the bisphenol F-type epoxy resin used as a raw material is 1 mol. The number of methacrylic groups contained in the methacrylic acid to react is 0.95 mol. Therefore, the methacrylic acid modified bisphenol F-type epoxy resin obtained becomes 95% partial methacrylate, and ratio of methacrylic group equivalent / epoxy group equivalent becomes 0.95 / 0.05 (= 19).

The average molecular weight of the methacrylic acid-modified bisphenol F-type epoxy resin was 48.5 (0.95x2 (= 1.9) number of hydroxyl groups contained in one molecule of methacrylic acid-modified bisphenol F-type epoxy resin It was 3.93x10 <^-3> (mol / g) when the hydrogen bond functional group was computed by dividing by = 492x0.95 + 320x0.05). The molecular weight of the bisphenol F type epoxy is 320, and the molecular weight of the sock end methacrylic acid modified bisphenol F type epoxy resin is 492.

[Synthesis Example 2]

Synthesis of Methacrylic Acid Modified Bisphenol F Type Epoxy Resin (50% Partial Methacrylate)

A methacrylic acid-modified bisphenol F-type epoxy resin (50% partial methacrylate) was obtained in the same manner as in Synthesis example 1 except that the amount of methacrylic acid was changed to 43 g.

Here, the number of epoxy groups contained in the bisphenol F-type epoxy resin used as a raw material is 1 mol like the above. The number of methacrylic groups contained in the methacrylic acid to react is 0.5 mol. Therefore, the methacrylic acid modified bisphenol F-type epoxy resin obtained is 50% partial methacrylate, and ratio of methacrylic group equivalent / epoxy group equivalent becomes 0.5 / 0.5 (= 1).

In addition, the number of hydroxyl groups contained in one molecule of the methacrylic acid-modified bisphenol F-type epoxy resin was 0.5 × 2 (= number of hydrogen-bonding functional groups) contained in the methacrylic acid-modified bisphenol F-type epoxy resin. It was 2.46x10 <^-3> (mol / g) when it computed by dividing 1.0) into the average molecular weight (406 = 492 * 0.5 + 320x0.5) of methacrylic acid modified bisphenol F-type epoxy resin.

[Synthesis Example 3]

Synthesis of Acrylic Acid Modified Phenol Novolac Epoxy Resin (50% Partial Acrylate)

179 g of liquid phenol novolac type epoxy resin (DOW Chemical Company: DEN431 epoxy equivalent 179 g / eq), 0.2 g p-methoxyphenol as polymerization inhibitor, 0.2 g triethylamine as catalyst and 36 g acrylic acid It injected into and let dry air blow, and made it react for 5 hours, stirring under reflux at 90 degreeC. The obtained compound was washed 20 times with ultrapure water to obtain an acrylic acid-modified phenol novolak-type epoxy resin (50% partial acrylate).

Here, the number of epoxy groups contained in the novolak-type epoxy resin used as a raw material is 1.0 mol. The number of acrylic groups contained in the acrylic acid to react is 0.5 mol. Therefore, the acryl-modified phenol novolak epoxy resin obtained is 50% partial methacrylate, and ratio of acryl group equivalent / epoxy group equivalent is 0.5 / 0.5 = 1.0.

Further, the hydrogen-bonding functional group of the acrylic modified phenol novolac epoxy resin is added to the number of hydroxyl groups (number of hydrogen-bonding functional groups) contained in one molecule of the acrylic modified phenol novolac-type epoxy resin. It was 2.3x10 <^-3> (mol / g) when it calculated by dividing by the average molecular weight (430 = 179x2 + 72) of acrylic acid modified phenol novolak-type epoxy resin.

[Synthesis Example 4]

13.4 g of trimethylolpropane, 0.02 g of BHT as a polymerization inhibitor, 0.001 g of dibutyltin dilaurylate and 66.6 g of isophorone diisocyanate were added as a catalyst, and the mixture was stirred under reflux at 60 ° C. The reaction was carried out for 2 hours. Next, 2.55 g of 2-hydroxyethyl acrylate and 11.1 g of glycidol were added and reacted for 2 hours with reflux stirring at 90 ° C. while blowing dry air. The obtained compound was washed 20 times with ultrapure water to obtain a urethane-modified partial acrylate.

Here, the number of epoxy groups contained in the glycidol as a raw material is 0.15 mol. The number of acryl groups contained in 2-hydroxyethyl acrylate is 0.022 mol. Therefore, the ratio of acryl group equivalent / epoxy group equivalent of the urethane modified partial acrylate obtained will be 0.022 / 0.128 (= 0.172).

The hydrogen-bonding functional group of the urethane-modified partial acrylate is calculated by dividing the number of urethane-bonded (hydrogen-bonded functional groups) contained in one molecule of the urethane-modified partial acrylate by the average molecular weight of the urethane-modified partial acrylate. It was 3.0 × 10 ⁻³ (mol / g).

Synthesis Example 5

Synthesis of Methacrylic Acid-Modified Bisphenol-A Epoxy Resin (90% Partial Methacrylate)

185 g of liquid bisphenol A epoxy resin (manufactured by Japan Epoxy Resin, trade name Epiclone YL980, epoxy equivalent 185 g / eq), 0.1 g p-methoxyphenol as polymerization inhibitor, 0.2 g triethanolamine as catalyst, and 77.4 g Methacrylic acid was added into the flask, and dry air was blown to react for 5 hours with stirring under reflux at 90 ° C. The obtained compound was washed 20 times with ultrapure water to obtain methacrylic acid-modified bisphenol A epoxy resin.

Here, the number of epoxy groups contained in the bisphenol-A epoxy resin used as a raw material is 1 mol. The number of methacrylic groups contained in the methacrylic acid to react is 0.90 mol. Therefore, the obtained methacryl modified bisphenol-A epoxy resin becomes 90% partial methacrylate, and ratio of methacryl group equivalent / epoxy group equivalent becomes 0.90 / 0.10 (= 9).

In addition, the number of hydroxyl groups contained in one molecule of the methacryl-modified bisphenol-A epoxy resin was 0.9 × 2 (= 1.8) in the hydrogen-bonding functional group of the methacryl-modified bisphenol A-type epoxy resin. It was 3.6x10 <^-3> (mol / g) when it calculated by dividing a dog by the average molecular weight (500) of methacryl modified bisphenol-A epoxy resin.

[Synthesis Example 6]

Synthesis of Methacrylic Acid-Modified Bisphenol-A Epoxy Resin (85% Partial Methacrylate)

185 g of liquid bisphenol A epoxy resin (manufactured by Japan Epoxy Resin, trade name Epiclone YL980, epoxy equivalent 185 g / eq), 0.1 g p-methoxyphenol as polymerization inhibitor, 0.2 g triethanolamine as catalyst and 73.1 g Methacrylic acid was added into the flask, and dry air was blown to react for 5 hours with stirring under reflux at 90 ° C. The obtained compound was washed 20 times with ultrapure water to obtain methacrylic acid-modified bisphenol A epoxy resin.

Here, the number of epoxy groups contained in the bisphenol-A epoxy resin used as a raw material is 1 mol. The number of methacrylic groups contained in the methacrylic acid to react is 0.85 mol. Therefore, the obtained methacryl modified bisphenol-A epoxy resin becomes 85% partial methacrylate, and ratio of methacryl group equivalent / epoxy group equivalent is 0.85 / 0.15 (= 5.7).

In addition, the number of hydroxyl groups contained in one molecule of the methacryl-modified bisphenol A-type epoxy resin was 0.85 × 2 (= 1.7). It was 3.4x10 <^-3> (mol / g) when computed by dividing a dog by the average molecular weight (500) of methacryl modified bisphenol-A epoxy resin.

Table 1 shows the physical properties of the (meth) acrylic modified epoxy resins obtained in Synthesis Examples 1 to 6.

Example 1

Methacrylic acid-modified bisphenol F-type epoxy resin (95% partial methacrylate) obtained in 43 parts by weight of Synthesis Example 1, 4 parts by weight of solid epoxy resin (manufactured by JER: Epicoat 1004, softening point 97 ° C), 20 parts by weight of acrylic 9 parts by weight of adipic acid dihydrazide (manufactured by Nihon Chemical Co., Ltd., ADH, melting point 177 to 184 ° C) as a resin (polyethylene glycol diacrylate, light acrylate 14EG-A manufactured by Kyoeisha Chemical Co., Ltd.), a heat curing agent, 2 parts by weight of an alkylphenone-based polymerization initiator (IRGACURE651 manufactured by Chiba Specialty Chemical Co., Ltd.), 13 parts by weight of silica particles: S-100 (manufactured by Nihon Shokubai Chemical Co., Ltd.), a (meth) acrylic acid ester monomer and a monomer copolymerizable with these Curable composition consisting of 7 parts by weight of thermoplastic resin particles (particulate polymer F351 (manufactured by Zeionization)) and 2 parts by weight of silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd .: KBM-403) The paper composition, and mixed sufficiently to a homogeneous solution using a 3-roll to give a sealant.

[Example 2]

9 parts by weight of 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin (manufactured by Ajinomoto Co., Ltd.) instead of adipic acid dihydrazide (ADH) A sealing compound was obtained in the same manner as in Example 1 except that CQDH and a melting point of 120 ° C. were used.

[Example 3]

A sealing compound was obtained in the same manner as in Example 1 except that no solid epoxy resin was used.

Comparative Example 1

Instead of the methacrylic acid-modified bisphenol F-type epoxy resin (95% partial methacrylate) obtained in Synthesis Example 1, the methacrylic acid-modified bisphenol F-type epoxy resin (50% partial methacrylate) obtained in Synthesis Example 2 The sealing compound was obtained like Example 1 except having used.

Comparative Example 2

9 parts by weight of 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin (manufactured by Ajinomoto Co., Ltd.) instead of adipic acid dihydrazide (ADH) A sealing compound was obtained in the same manner as in Comparative Example 1 except that CQDH) was used.

[Comparative Example 3]

43 parts by weight of acrylic acid-modified phenol novolac-type epoxy resin (50% partial acrylate) obtained in Synthesis Example 3, 20 parts by weight of urethane-modified partial acrylate obtained in Synthesis Example 4, 4 parts by weight of solid epoxy resin (manufactured by JER Corporation: Epicoat 1004, a softening point of 97 ° C.), and 9 parts by weight of 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin (manufactured by Ajinomoto Co., Ltd., Amicoa VDH) as a heat curing agent, and a photopolymerization initiator. 2 parts by weight of 2,2'-diethoxyacetophenone, 13 parts by weight of silica particles: S-150 (manufactured by Nihon Shokubai Chemical Co., Ltd.), 7 parts by weight of thermoplastic resin particles (particulate polymer F351 (manufactured by Zeonization)), and 1 The curable resin composition which consists of a weight part silane coupling agent (KBM-403 by Shin-Etsu Chemical Co., Ltd.) was fully mixed so that it might become a uniform liquid using three rolls, and the sealing compound was obtained.

[Comparative Example 4]

Instead of the methacrylic acid-modified bisphenol F-type epoxy resin (95% partial methacrylate) obtained in Synthesis Example 1, the methacrylic acid-modified bisphenol A epoxy resin (90% partial methacrylate) obtained in Synthesis Example 5 The sealing compound was obtained like Example 1 except having used.

[Comparative Example 5]

Instead of the methacrylic acid-modified bisphenol F-type epoxy resin (95% partial methacrylate) obtained in Synthesis Example 1, the methacrylic acid-modified bisphenol A epoxy resin (85% partial methacrylate) obtained in Synthesis Example 6 was The sealing compound was obtained like Example 1 except having used.

Regarding the sealing agents obtained in Examples 1 to 3 and Comparative Examples 1 to 5, 1) viscosity stability, 2) NI point of liquid crystal, 3) UV curability, 4) display characteristics of liquid crystal display panel, and 5) adhesiveness It evaluated by the following method.

1) viscosity stability

The sealing compound obtained in the Example and the comparative example was extract | collected so that the weight of the sealing compound in the syringe for dispensing might be 10 g, and then the defoaming process was performed. About 2 g of them, the initial viscosity was measured at room temperature (23 degreeC) using the E-type viscosity meter. Subsequently, after storing this sample in 23 degreeC 50% RH for 1 week, viscosity was measured on the same conditions again. The increase rate of the viscosity after storage for one week with respect to the initial viscosity at this time was calculated | required.

○ (excellent) that the rate of increase in viscosity after storage relative to initial viscosity is 1.2 times or less; Δ (slightly inferior) of more than 1.2 times and less than or equal to 1.5 times; The thing exceeding 1.5 times was made into x (deterioration).

2) N-I point of liquid crystal (nematic-isotropic transition temperature)

0.1 g of (uncured) sealing agent and 1 g of liquid crystal (MLC-11900-000, manufactured by Merck Co., Ltd.) obtained in Examples and Comparative Examples were added to a vial bottle, and heated at 120 ° C. for 1 hour to prepare a liquid crystal mixture. Obtained. Subsequently, this liquid crystal mixture was taken out and the N-I point was measured at the temperature increase rate of 5 degree-C / min by DTA (differential thermal analysis).

The N-I point of the liquid crystal is greatly changed when a small amount of impurities are contained in the liquid crystal. For this reason, the smaller the amount of change in the N-I point of the liquid crystal (before heating) of the N-I point of the liquid crystal mixture after heating, the less the dissolution of the sealing component in the liquid crystal. ○ (excellent) that the amount of change of the N-I point of the liquid crystal mixture to the N-I point of the liquid crystal (original) is less than 5 ° C; The thing of 5 degrees C or more was made into (deterioration).

3) UV curable

The viscosity rise behavior after irradiating the ultraviolet-ray of 5 mW / cm <^2> to the sealing compound obtained by the Example and the comparative example was measured using VISCOANALYSER VAR100 by REOLOGICA INSTRUMENT. The hardening time until the viscosity of the sealing compound after ultraviolet irradiation became a value of 50% with respect to a saturation viscosity value was measured. A saturated viscosity value is a viscosity at the time of fully hardening a sealing compound. It can be judged that the hardening time is short, it is excellent in sclerosis | hardenability.

4) Display characteristics of the liquid crystal display panel

The sealing compound obtained in the Example and the comparative example was put on the 40 mm x 45 mm glass substrate (RT-DM88-PIN by the EHC company) by which the transparent electrode and the alignment film were previously formed using the dispenser (shotmaster: Musashi engineering agent), A 35 mm × 40 mm square seal pattern (cross section 3500 μm ² ) (main seal) and the same seal pattern (38 mm × 43 mm square seal pattern) were formed in the outer circumference thereof.

Next, the liquid crystal material (MLC-119000-000: product made by Merck) corresponded to the panel internal capacity after bonding was dripped precisely using the dispenser in the frame of a main seal. Subsequently, after the corresponding glass substrate was bonded under reduced pressure, the atmosphere was opened and bonded. And after hold | maintaining the two bonded glass substrates in a light shielding box for 3 minutes, the ultraviolet-ray of 2000mJ / cm <^2> was irradiated and it heated at 100 degreeC for 1 hour.

In the obtained liquid crystal display panel, the color unevenness generate | occur | produced in the liquid crystal of the seal | sticker part periphery was visually observed before and after 500 hours and storage | storage in a thermostat at 70 degreeC and 95% RH. ○ (excellent) that no color spots were found; What was confirmed was made into x (deterioration).

In addition, the liquid crystal display panel taken out after storage in a thermostat is driven at an applied voltage of 5 V using a DC power supply device, and liquid crystal display is performed by whether or not the liquid crystal display function near the liquid crystal sealant functions normally from the beginning of driving. The display characteristics of the panel were evaluated.

The display characteristics are ○ (excellent) when the liquid crystal display function can be normally exhibited until the time, and △ (slightly inferior) when the abnormality of the liquid crystal display function is confirmed at less than 0.3 mm near the time of the seal. And the case where abnormality of a display function was confirmed at 0.3 mm or more in the vicinity at the time of sealing was made into x (deterioration).

5) Adhesive

In said 4), planar tensile strength was measured about the sample of the liquid crystal display panel after having stored in the thermostat at the tensile velocity of 2 m / min using the tension test apparatus (made by Indesco). Adhesiveness was evaluated as follows.

Adhesive strength of 15 MPa or more: ○ (excellent)

Adhesive strength is 7 MPa or more and less than 15 MPa: △ (slightly inferior)

Adhesive strength less than 7 MPa: × (deteriorated)

Table 2 shows the evaluation results of Examples 1-3 and Comparative Examples 1-5.

As shown in Table 2, the sealing agents of Examples 1 to 3 using a (meth) acrylic-modified epoxy resin having a ratio of (meth) acrylic group equivalents / epoxy group equivalents to 19 had a ratio of (meth) acrylic group equivalents / epoxy group equivalents 9 It turns out that the NI point and liquid crystal display characteristic of a liquid crystal are very favorable rather than the sealing compound of Comparative Examples 1-5 using the (meth) acryl modified epoxy resin which is the following. This is the (meth) acryl-modified epoxy resin contained in the sealing compound of Examples 1-3, compared with the (meth) acrylic-modified epoxy resin contained in the sealing compound of Comparative Examples 1-5, the hydroxyl group with respect to an unreacted epoxy group. It is considered that the solubility with respect to a liquid crystal was suppressed remarkably because the content rate of is high.

Moreover, since the (meth) acryl modified epoxy resin contained in the sealing compound of Examples 1-3 is higher in content rate of a methacryl group than the (meth) acrylic modified epoxy resin of Comparative Examples 1-5, ultraviolet curability is also favorable. You can see that.

Moreover, since the sealing agent containing solid epoxy resin is high from the comparison of Example 1 and 3, it is suggested that moisture resistance is high, since the display characteristic after drive is high. In addition, it turns out that the sealing compound containing solid epoxy resin is high in adhesiveness.

This application claims the priority based on the patent application 2010-072893 for which it applied on March 26, 2010. All the content described in the said application specification and drawing is integrated in this specification.

Since the liquid crystal sealing agent of this invention contains many hydroxyl groups, melt | dissolution to a liquid crystal is suppressed also in high temperature and high humidity. For this reason, when the hardened | cured material of the liquid crystal sealing agent of this invention is applied as a sealing member (liquid crystal sealing part), there can be provided the liquid crystal panel excellent in display reliability, without the leakage of a liquid crystal to the sealing member. For this reason, the liquid crystal sealing agent of this invention is suitable for manufacture of a liquid crystal display panel.

Claims (10)

(Meth) acryl-modified epoxy resin obtained by reacting an epoxy resin containing two or more epoxy groups in a molecule with (meth) acrylic acid, a thermosetting agent, and a photoinitiator,
The (meth) acryl-modified epoxy resin has a hydrogen-bonding functional group containing a hydroxyl group produced by the reaction of an epoxy resin containing two or more epoxy groups in the molecule and the (meth) acrylic acid, and
The (meth) acryl group equivalent / epoxy group equivalent of the said (meth) acryl modified epoxy resin is more than 9,
The hydrogen-bonding functional group is a liquid crystal sealing agent of 3 × 10 ^-3 to 5 × 10 ^-3 mol / g. The method of claim 1,
The epoxy resin containing two or more epoxy groups in the said molecule | numerator is a bifunctional epoxy resin chosen from the group which consists of a biphenyl type epoxy resin, a naphthalene type epoxy resin, and a bisphenol type epoxy resin. The method of claim 2,
The bifunctional epoxy resin is a bisphenol A type epoxy resin or a bisphenol F type epoxy resin. The method of claim 1,
The liquid crystal sealing agent which further contains 1-20 weight part of solid epoxy resins whose softening point is 40 degreeC or more and 150 degrees C or less with respect to 100 weight part of said liquid crystal sealing agents. The method of claim 1,
Liquid crystal sealing agent whose said photoinitiator is 1 or more types of compounds chosen from the group which consists of an alkyl phenone type compound, an acyl phosphine oxide type compound, a titanocene type compound, and an oxime ester type compound. The method of claim 1,
The said thermosetting agent is liquid crystal sealing agent whose melting | fusing point is 50 degreeC or more and 250 degrees C or less. The method of claim 1,
The said thermosetting agent is a liquid crystal sealing agent which is 1 or more types chosen from the group which consists of an organic acid dihydrazide type compound, an imidazole type compound, a dicyandiamide compound, and a polyamine type compound. The method of claim 1,
Liquid crystal sealing agent used for manufacture of the liquid crystal display panel by a liquid crystal dropping method. Forming a seal pattern on one substrate using the liquid crystal sealing agent according to claim 1,
In a state where the seal pattern is uncured, dropping liquid crystal into a seal pattern region of the one substrate or the other substrate corresponding to the one substrate;
Overlapping the one substrate with the other substrate, and
A method of manufacturing a liquid crystal display panel, comprising a step of photocuring the seal pattern and then thermal curing. With a display board,
An opposite substrate corresponding to the display substrate;
A seal member having a frame shape interposed between the display substrate and the opposing substrate;
A liquid crystal display panel comprising a liquid crystal layer filled in a space surrounded by the seal member between the display substrate and the opposing substrate.
The said sealing member is a liquid crystal display panel of hardened | cured material of the liquid crystal sealing agent of Claim 1.