TW201606060A - Liquid crystal sealing agent and production method for liquid crystal display panel - Google Patents

Abstract

The present invention addresses the problem of providing a liquid crystal sealing agent that has a uniform line width even in a fine seal pattern, that can bond two substrates at a high bonding strength, and that does not easily leak liquid crystals. In order to solve said problem, the present invention provides a liquid crystal sealing agent that includes (1a) a (meth)acrylic resin or (1b) a (meth)acryl-modified epoxy resin that has, in the molecule thereof, an epoxy group and a (meth)acrylic group, (2) an organic filler (A) that has an average particle size of 4-13 [mu]m, (3) an organic filler (B) that has an average particle size of 0.05-1 [mu]m, and (4) a radical polymerization initiator, wherein, when the content (mass) of component (2) is W1 and the content (mass) of component (3) is W2, 0.25 ≤ W1/(W1 + W2) ≤ 0.75.

Description

Liquid crystal sealing agent and method of manufacturing liquid crystal display panel

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

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

The liquid crystal sealing agent for obtaining the sealing member has a small amount of use, but it has a large influence on the reliability of the liquid crystal display panel due to direct contact with the liquid crystal. Therefore, in order to achieve high image quality of the liquid crystal display panel, a high degree and various characteristics are required for the liquid crystal sealing agent.

One of the manufacturing methods of a general liquid crystal display panel includes a liquid crystal injection process. The liquid crystal injection process is generally as follows: (1) applying a liquid crystal sealing agent to the inner edge of a transparent substrate to form a frame, and (2) pre-curing the substrate to dry the liquid crystal sealing agent, and bonding the other One substrate, (3) the two substrates are heated and pressed, and the substrates are bonded to each other to form a frame (unit) of the liquid crystal sealing agent between the substrates. Next, (4) an appropriate amount of liquid crystal is injected into the empty cell, and then the liquid crystal injection port is sealed, thereby manufacturing a liquid crystal display panel.

On the other hand, in recent years, as a method of manufacturing a liquid crystal display panel which is expected to improve productivity, a liquid crystal dropping process is being studied. The liquid crystal dropping process is as follows: (1) applying a liquid crystal sealing agent to the inner edge of the transparent substrate to form a frame for filling the liquid crystal, (2) dropping the liquid crystal into the frame, and (3) liquid crystal sealing agent. In the case of the unhardened state, after the two substrates are superposed under high vacuum, (4) a method of curing the liquid crystal sealing agent to produce a panel. In the liquid crystal dropping process, a light and thermosetting liquid crystal sealing agent is sometimes used. In the case of using such a liquid crystal sealing agent, for example, in the step (3), the liquid crystal sealing agent is pre-cured by irradiating light such as ultraviolet rays, and then post-curing is performed by heating.

As the liquid crystal sealing agent for the liquid crystal dropping process, for example, a liquid epoxy resin is proposed (Patent Document 1). In addition, in order to improve the adhesion of the liquid crystal sealing agent or to improve the stress relaxation property, a rubber-like component or the like is added, or a filler such as glass fiber or glass particles is added in order to improve the heat resistance of the liquid crystal sealing agent (Patent Document 2) ). Further, a liquid crystal sealing agent prepared by disposing resin fine particles having a core-shell structure has been proposed (Patent Document 3).

Further, it is also proposed to add an organic filler having a particle diameter larger than the cell gap to the liquid crystal sealing agent (Patent Documents 4 to 6). If an organic filler having a large particle diameter is sandwiched between the two substrates, the organic filler is compressed, and the gap between the two substrates is filled without gaps, so that leakage of liquid crystal is easily suppressed (liquid crystal enters the liquid crystal sealing or breaks the liquid crystal sealing) And leaked out).

Here, in recent years, it has been demanded to enlarge the display area of the liquid crystal display panel, and it is required to make the width of the frame provided around the display area thin. Accordingly, the sealing pattern of the liquid crystal sealing agent is required to be thin. Prior art literature

Patent Document 1: Japanese Patent No. 3955038 Patent Document 2: International Publication No. 2004/039885 Patent Document 3: Japanese Patent Laid-Open Publication No. 2010-277072 No. JP-A No. 2010-277072 Patent Document 4: Japanese Patent No. 5531166 Patent Document 5: International Publication Patent Document No. 2014/185374: Japanese Patent Laid-Open Publication No. 2010-256777

[Problems to be solved by the invention]

However, it is difficult for a general liquid crystal sealing agent to form a fine seal pattern with a uniform line width. Therefore, when the seal pattern is made thin, a portion having a small line width is locally generated, and at this portion, the strength of the sealing member is lowered, or the adhesion strength to the substrate is likely to be lowered. That is, if the line width of the seal pattern is not uniform, problems such as leakage of liquid crystal are likely to occur. In addition, as described in Patent Document 4, when the liquid crystal sealing agent contains an organic filler having a large particle diameter, the line width of the seal pattern tends to be uneven.

Accordingly, an object of the present invention is to provide a liquid crystal sealing agent which has a uniform line width even when the sealing pattern is made fine, and which can bond two substrates with high bonding strength, and it is difficult to cause leakage of liquid crystal. [Means for solving the problem]

The first aspect of the invention is related to the liquid crystal sealing agent shown below. [1] A liquid crystal sealing agent comprising: (1a) a (meth)acrylic resin or (1b) a (meth)acrylic modified epoxy resin having an epoxy group and a (meth)acrylic group in a molecule; (2) an organic filler A having an average particle diameter of 4 μm to 13 μm, (3) an organic filler B having an average particle diameter of 0.05 μm to 1 μm, and (4) a radical polymerization initiator, and when The content (mass) of the component (2) is W1, and when the content (mass) of the component (3) is W2, 0.25 ≦ W1/(W1 + W2) ≦ 0.75.

[2] The liquid crystal sealing agent according to [1], wherein the W1 and the W2 satisfy the following formula, 0.4≦W1/(W1+W2)≦0.6. [3] The liquid crystal sealing agent according to [1], wherein the component (2) and the resin unit are combined with respect to 100 parts by mass of the resin unit in which the component (1a) and the component (1b) are combined. The total amount of the component (3) is from 20 parts by mass to 100 parts by mass. [4] The liquid crystal sealing agent according to any one of [1], wherein the component (2) and the component (3) are respectively selected from the group consisting of an anthrone fine particle, an acrylic fine particle, and a styrene fine particle. And one or more microparticles in the group consisting of polyolefin microparticles. [5] The liquid crystal sealing agent according to any one of [1] to [4], wherein the component is 100 parts by mass with respect to the resin unit in which the component (1a) and the component (1b) are combined. The content of (4) is from 0.01 part by mass to 3.0 parts by mass.

[6] The liquid crystal sealing agent according to any one of [1] to [5] further comprising (5) an epoxy hardener, and the component (1a) and the component (1b) are 100 parts by mass of the combined resin unit, and the content of the component (5) is from 3 parts by mass to 30 parts by mass. [7] The liquid crystal sealing agent according to any one of [1] to [6] further comprising (6) an inorganic filler, and a resin combined with the component (1a) and the (1b) 100 parts by mass of the unit, and the content of the component (6) is from 3 parts by mass to 30 parts by mass. [8] The liquid crystal sealing agent according to any one of [1] to [7] further comprising (7) an opacifier, and with respect to the resin unit in which the (1a) and the (1b) are combined The content of the component (7) is from 3 parts by mass to 30 parts by mass per 100 parts by mass. [9] The liquid crystal sealing agent according to any one of [1] to [8] wherein the viscosity at 25 ° C and 2.5 rpm measured by an E-type viscosity meter is 200 Pa·s to 450 Pa·s. . [10] The liquid crystal sealing agent according to any one of [1] to [9], which is used for manufacturing a liquid crystal display panel by a liquid crystal dropping process.

A second aspect of the invention relates to a liquid crystal sealing agent shown below. [11] A method of manufacturing a liquid crystal display panel, comprising: a liquid crystal sealing agent according to any one of [1] to [9], wherein a sealing pattern is formed on one of the substrates; a step of dropping liquid crystal on a sealing pattern region of one of the substrates or another substrate paired with the one of the substrates in a state where the sealing pattern is uncured; and the one of the substrates is a step of overlapping another substrate; and a step of hardening the sealing pattern. [Effects of the Invention]

The liquid crystal sealing agent of the present invention is used for forming a sealing member of a liquid crystal display panel, and even if the line width is made thinner, the line width is easily made uniform. As a result, the strength of the seal pattern or the cured product (sealing member) of the liquid crystal sealing agent is likely to be uniform, and leakage of liquid crystal or the like is less likely to occur. Further, the bonding strength between the sealing member and the substrate is also high. Therefore, a liquid crystal display panel with high reliability and a liquid crystal display device with high reliability can be obtained.

1. Liquid Crystal Sealant The liquid crystal sealing agent of the present invention comprises (1) a resin, (2) two kinds of organic fillers having different average particle diameters, and (3) a radical polymerization initiator. Further, the liquid crystal sealing agent may optionally contain (4) an epoxy curing agent, (5) an inorganic filler, (6) an epoxy resin, (7) an opacifier, and the like.

As described above, when a general liquid crystal sealing agent is used to form a fine sealing pattern, it is difficult to make the line width uniform, and it is easy to locally generate a portion having a small line width. Further, when an internal pressure is applied to the portion, the liquid crystal is likely to leak, or the sealing member and the substrate are easily peeled off.

Here, the liquid crystal sealing agent of the present invention contains two types of organic fillers having different average particle diameters, that is, an organic filler A having a relatively large average particle diameter and an organic filler B having a relatively small average particle diameter. Further, the organic filler A having a relatively large average particle diameter is crushed between the two substrates of the liquid crystal display panel, and the gaps are filled without gaps. On the other hand, the organic filler B having a relatively small average particle diameter fills the gap between the organic fillers A. Therefore, the line width of the seal pattern is likely to become uniform, and it is difficult to locally generate a region having low strength. Further, since the organic filler B has high stress relaxation ability, the sealing strength of the sealing member obtained by curing the liquid crystal sealing agent is easily improved. In other words, according to the liquid crystal sealing agent of the present invention, it is possible to obtain a liquid crystal display panel in which leakage of liquid crystal is small, and it is difficult to peel off the substrate, and the reliability is high.

(1) Resin component The liquid crystal sealing agent contains at least: (1a) (meth)acrylic resin or (1b) (meth)acrylic acid modified ring having an epoxy group and a (meth)acrylic group in one molecule. Oxygen resin. These resins may be contained alone or in combination of two or more. When the (1b) (meth)acrylic acid-modified epoxy resin is contained in the liquid crystal sealing agent, the moisture resistance of the cured product (sealing member) of the liquid crystal sealing agent is improved.

(1a) The (meth)acrylic resin contains one or more (meth)acrylic groups. The (meth)acrylic acid means either methacrylic acid or acrylic acid. The (meth)acrylic resin may be a monomer having a (meth)acrylic group-containing compound, or may be an oligomer or a polymer. However, the (1a) (meth)acrylic resin does not contain a compound having an epoxy group.

(1a) Examples of the (meth)acrylic resin include diacrylates and/or dimethacrylates such as polyethylene glycol, propylene glycol, and polypropylene glycol; and tris(2-hydroxyethyl) isocyanurate. Diacrylate and/or dimethacrylate; diacrylate and/or diol of diol obtained by adding 4 moles or more of ethylene oxide or propylene oxide to 1 mole of neopentyl glycol a methacrylate; a diacrylate and/or a dimethacrylate of a diol obtained by adding 2 moles of ethylene oxide or propylene oxide to 1 mole of bisphenol A; a diacrylate or triacrylate and/or dimethacrylate or trimethacrylate obtained by adding 3 moles or more of ethylene oxide or propylene oxide to trimethylolpropane; a diacrylate and/or dimethacrylate of a diol obtained by adding 4 moles or more of ethylene oxide or propylene oxide to 1 mole of bisphenol A; isocyanuric acid tris(2- Triacrylate and/or trimethacrylate of hydroxyethyl) ester; triacrylate and/or trimethacrylate of trimethylolpropane, or oligomer thereof a triacrylate and/or trimethacrylate of pentaerythritol, or an oligomer thereof; a polyacrylate and/or a polymethacrylate of dipentaerythritol; a tri(acryloxyethyl) isocyanurate; Caprolactone modified tris(propylene methoxyethyl) isocyanurate; caprolactone modified tris(methacryloxyethyl) isocyanurate; alkyl modified dipentaerythritol Acrylates and/or polymethacrylates; polyacrylates and/or polymethacrylates of caprolactone modified dipentaerythritol; diacrylates and/or dimethacrylates of hydroxypivalic acid neopentyl glycol Ester; caprolactone modified hydroxypivalic acid neopentyl glycol diacrylate and / or dimethacrylate; ethylene oxide modified phosphoric acid acrylate and / or dimethacrylate; ethylene oxide Modified acrylate and/or dimethacrylate of alkylated phosphoric acid; neopentyl glycol, trimethylolpropane, oligoacrylate of pentaerythritol and/or oligomeric methacrylate.

Further, in particular, the weight average molecular weight of the (1a) (meth)acrylic resin may be, for example, about 310 to 1,000. (1a) The weight average molecular weight Mw of the (meth)acrylic resin can be measured, for example, by gel permeation chromatography (GPC) (in terms of polystyrene).

The amount of the (1a) (meth)acrylic resin contained in the liquid crystal sealing agent depends on the curing property of the liquid crystal sealing agent required, but is preferably 0 parts by mass to 80 parts by mass based on 100 parts by mass of the liquid crystal sealing agent. The parts by mass are more preferably 0 parts by mass to 60 parts by mass.

(1b) The (meth)acrylic acid-modified epoxy resin is preferably a (meth)acrylic acid modified by reacting an epoxy resin with (meth)acrylic acid, for example, in the presence of a basic catalyst. Epoxy resin.

On the other hand, the (1b) (meth)acrylic acid-modified epoxy resin has both an epoxy group and a (meth)acrylic group in the molecule, and thus can have both photocurability and thermosetting property. Further, even if the (1b) (meth)acrylic acid-modified epoxy resin is derived from an amorphous epoxy resin, since the resin contains a hydroxyl group generated by a reaction with (meth)acrylic acid, it can be sufficiently The dissolution of the liquid crystal is suppressed.

The epoxy resin which is a raw material of the (1b) (meth)acrylic acid-modified epoxy resin may be a bifunctional or higher epoxy resin having two or more epoxy groups in the molecule, and includes a bisphenol A type. , bisphenol F type, 2,2'-diallyl bisphenol A type, bisphenol type AD, and bisphenol type epoxy resin such as hydrogenated bisphenol type; phenol novolak type, cresol novolak type, joint A novolak type epoxy resin such as a novolac type or a trisphenol novolak type; a biphenyl type epoxy resin; a naphthalene type epoxy resin. The (meth)acrylic modified epoxy resin obtained by modifying (meth)acrylic acid of a trifunctional or tetrafunctional polyfunctional epoxy resin has a high crosslinking density, and the bonding strength between the sealing member and the substrate is liable to decrease. . Therefore, a (meth)acrylic modified epoxy resin obtained by modifying a bifunctional epoxy resin with (meth)acrylic acid is preferred.

The bifunctional epoxy resin is preferably a biphenyl type epoxy resin, a naphthalene type epoxy resin, and a bisphenol type epoxy resin. Among them, from the viewpoint of coating efficiency of the liquid crystal sealing agent, bisphenol A is preferred. Type and bisphenol type epoxy resin such as bisphenol F type. The bisphenol type epoxy resin has an advantage of being excellent in coatability as compared with an epoxy resin such as a diphenyl ether type.

The epoxy resin to be used as the raw material may be one type or a combination of two or more types. Further, the epoxy resin to be a raw material is preferably purified by a molecular distillation method, a washing method, or the like.

(1b) The weight average molecular weight of the (meth)acrylic acid-modified epoxy resin may be, for example, about 310 to 1,000. (1b) The weight average molecular weight Mw of the (meth)acrylic acid-modified epoxy resin can be measured, for example, by gel permeation chromatography (GPC) (in terms of polystyrene).

The amount of the (1b) (meth)acrylic acid-modified epoxy resin contained in the liquid crystal sealing agent is preferably from 0 to 80 parts by mass, more preferably from 0 to 60 parts by mass, per 100 parts by mass of the liquid crystal sealing agent. Parts by mass.

The (1a) (meth)acrylic resin and the (1b) (meth)acrylic acid-modified epoxy resin preferably contain a hydrogen-bonding functional group such as a hydroxyl group, a urethane bond, a guanamine group or a carboxyl group. Examples of the hydrogen-bonding functional group also include a hydroxyl group formed by reacting an epoxy group of an epoxy resin with (meth)acrylic acid. Further, it also includes a hydroxyl group or a urethane contained in (meth)acrylic acid or an epoxy resin which is a raw material of (1a) (meth)acrylic resin and (1b) (meth)acrylic modified epoxy resin. A bond, a carboxyl group, a guanamine group, and the like.

When the hydrogen-bonding functional group is contained in the (1a) (meth)acrylic resin and the (1b) (meth)acryl-modified epoxy resin, the compatibility of the resins with the hydrophobic liquid crystal material is lowered. As a result, it is difficult for the liquid crystal sealing agent to be dissolved in the liquid crystal material, and a liquid crystal sealing agent suitable for the liquid crystal dropping process can be obtained.

The (1a) (meth)acrylic resin and the (1b) (meth)acrylic acid-modified epoxy resin contained in the liquid crystal sealing agent preferably have a hydrogen-bonding functional group equivalent of 1.0 × 10 ^-4 mol/g. 5 × 10 ^-3 mol / g, more preferably 2.0 × 10 ^-3 mol / g - 4.5 × 10 ^-3 mol / g. If the hydrogen-bonding functional group equivalent is less than 1.0×10 ^-4 mol/g, (1a) 1 molecule of (meth)acrylic resin or (1b) hydrogen contained in 1 molecule of (meth)acrylic acid modified epoxy resin The amount of the binding functional group is small, and it is difficult to obtain a dissolution inhibiting effect on the liquid crystal. If the hydrogen-bonding functional group equivalent exceeds 5 × 10 ^-3 mol/g, the moisture resistance of the cured product of (1a) (meth)acrylic resin or (1b) (meth)acrylic modified epoxy resin is liable to decrease. .

The hydrogen coupling functional group equivalent (mol/g) of (1a) (meth)acrylic resin and (1b) (meth)acrylic modified epoxy resin is expressed as: "1 molecule of (1a) (meth)acrylic acid The amount of hydrogen-bonding functional groups contained in the resin or (1b) (meth)acrylic acid-modified epoxy resin"/(1a) (meth)acrylic resin or (1b) (meth)acrylic acid modified ring The weight average molecular weight (Mw) of the oxygen resin. For example, in the case where the hydrogen-bonding functional group contained in the (meth)acrylic acid-modified epoxy resin is only a hydroxyl group generated by the reaction of (meth)acrylic acid and an epoxy resin, The number of moles of the (meth)acrylic acid to be reacted was determined by dividing the weight average molecular weight (Mw) of the (meth)acrylic acid-modified epoxy resin.

Here, the hydrogen-bonding functional group equivalent of the (1a) (meth)acrylic resin is adjusted by the number of hydrogen-bonding functional groups contained in the (meth)acrylic resin. On the other hand, the hydrogen-bonding functional group equivalent of the (1b) (meth)acrylic acid-modified epoxy resin can be adjusted, for example, by the molar number of (meth)acrylic acid which reacts with the epoxy resin which becomes a raw material; or The amount of the hydrogen-bonding functional group (meth)acrylic acid or epoxy resin which is a raw material is adjusted and controlled. (1b) The (meth)acrylic acid-modified epoxy resin preferably has a hydroxyl value equivalent of from 2.0 × 10 ^-3 mol / g to 5 × 10 ^-3 mol / g.

The total content of the (1a) (meth)acrylic resin and the (1b) (meth)acrylic modified epoxy resin is preferably 40 parts by mass to 80 parts by mass, more preferably 50%, based on 100 parts by mass of the liquid crystal sealing agent. Parts by mass to 75 parts by mass.

(2) Organic filler The liquid crystal sealing agent contains an organic filler A having an average particle diameter of 4 μm to 13 μm and an organic filler B having an average particle diameter of 0.05 μm to 1 μm. The average particle diameter of the organic filler A is preferably from 4 μm to 10 μm, particularly preferably from 5 μm to 8 μm. On the other hand, the average particle diameter of the organic filler B is preferably from 0.1 μm to 0.8 μm, particularly preferably from 0.1 μm to 0.6 μm.

The average particle size of the filler can be determined by microscopic methods, in particular by image analysis by an electron microscope. Specifically, the liquid crystal sealing agent was subjected to image analysis, and 50 organic powders having a particle diameter of 4 μm or more were selected to measure the average particle diameter as the average particle diameter of the organic filler A. Similarly, the liquid crystal sealing agent was subjected to image analysis, and 50 organic powders having a particle diameter of 1 μm or less were selected to measure the average value of the particle diameter as the average particle diameter of the organic filler B.

In the sealing member obtained by curing the liquid crystal sealing agent of the present invention, as described above, the organic filler A is reversibly or irreversibly deformed to suppress leakage of the liquid crystal. On the other hand, the gap between the organic fillers A is filled by the organic filler B, and the linearity of the sealing pattern of the liquid crystal sealing agent in the line width direction is improved. Further, by the organic filler B, the stress relaxation property of the sealing member is improved, and the bonding strength between the sealing member and the substrate is improved.

Here, when the mass of the organic filler A contained in the liquid crystal sealing agent is W1 and the mass of the organic filler B is W2, W1/(W1+W2) is 0.25 to 0.75, preferably 0.3 to 0.7, especially preferably 0.4 to 0.6. When the organic filler A is in the above range, leakage of liquid crystal is easily suppressed. In addition, when the amount of the organic filler A is excessive, the line width of the seal pattern tends to be uneven. However, when the organic filler A and the organic filler B are contained in the above ratio, the line width of the seal pattern is likely to be uniform. In addition, when the amount of the organic filler B is excessive, the viscosity of the liquid crystal sealing agent is excessively increased, and the thixotropy is lowered. When the liquid crystal sealing agent is prepared, bubbles are easily entered, and bubbles are hard to escape, but if it is in the above range, the liquid crystal sealing agent is Viscosity is easily limited to a moderate range.

An example of a method of measuring the ratio of the mass W1 of the organic filler A contained in the liquid crystal sealing agent to the mass W2 of the organic filler B is as follows. A cured film having a predetermined film thickness was produced using a liquid crystal sealing agent, and the cured film was observed by a transmission electron microscope (TEM). Next, the particle size and number of organic fillers present in a certain volume were analyzed. The organic filler to be observed is divided into an organic filler A having a particle diameter of 4 μm or more and an organic filler B having a particle diameter of 1 μm or less, and the volume of the organic filler calculated from the respective particle diameters, and the specific gravity of the organic filler. The mass W1 of the organic filler A contained in the liquid crystal sealing agent and the mass W2 of the organic filler B were calculated.

Here, the organic filler A contained in the liquid crystal sealing agent is 100 parts by mass of the total (resin unit) of the (1a) (meth)acrylic resin and the (1b) (meth)acrylic modified epoxy resin. The total amount of the organic filler B is preferably 20 parts by mass to 100 parts by mass, more preferably 20 parts by mass to 80 parts by mass, even more preferably 20 parts by mass to 60 parts by mass. When the total amount of the organic filler A and the organic filler B is 20 parts by mass or more, the effect of adding the organic filler is easily obtained. On the other hand, when the amount of the organic filler A and the organic filler B is 100 parts by mass or less, the filler A and the filler B are easily adhered sufficiently by the resin component.

In addition, 100 parts by mass of the total of (1a) (meth)acrylic resin and (1b) (meth)acrylic modified epoxy resin (resin unit), the organic filler A contained in the liquid crystal sealing agent The amount is preferably from 5 parts by mass to 75 parts by mass, more preferably from 6 parts by mass to 70 parts by mass, even more preferably from 6 parts by mass to 60 parts by mass, particularly preferably from 6 parts by mass to 40 parts by mass. In addition, 100 parts by mass of the total of (1a) (meth)acrylic resin and (1b) (meth)acrylic modified epoxy resin (resin unit), the organic filler B contained in the liquid crystal sealing agent The amount is also preferably 5 parts by mass to 75 parts by mass, more preferably 6 parts by mass to 70 parts by mass, still more preferably 6 parts by mass to 60 parts by mass, particularly preferably 6 parts by mass to 40 parts by mass.

The organic filler A and the organic filler B are preferably difficult to be melted at a heat hardening temperature of the liquid crystal sealing agent. Further, in particular, the softening point of the organic filler A and the organic filler B is preferably from 30 ° C to 120 ° C. When the softening point of the organic filler A is in the above range, the organic filler A tends to be easily deformed at this temperature, and the organic filler A is easily deformed between the two substrates, and the gap therebetween is easily filled. In addition, when the softening point of the organic filler B is in the above range, the organic filler B easily enters the gap between the organic fillers A, and the line width of the seal pattern is likely to be uniform.

Examples of the organic filler A and the organic filler B include fine particles selected from the group consisting of styrene fine particles such as anthrone fine particles, acrylic fine particles, and styrene-divinylbenzene copolymer, and polyolefin fine particles.

Further, the shape of the organic filler A and the organic filler B is not particularly limited, but is preferably spherical, and particularly preferably spherical. The spherical shape means a ratio b/a of the minimum value (b) of the diameter of each particle to the maximum value (a) of 0.9 to 1.0. The particle size of the filler can be determined by microscopy, in particular by image analysis by an electron microscope. Further, the surfaces of the organic filler A and the organic filler B are preferably smooth. When the surface is smooth, the specific surface area is lowered, and the amounts of the organic filler A and the organic filler B which can be added to the liquid crystal sealing agent are increased. The organic filler A and the organic filler B are preferably spherical in the liquid crystal sealing agent or have a smooth surface. However, the sealing member (hardened material of the liquid crystal sealing agent) in the liquid crystal display panel may not be spherical or may be Has a smooth surface. The reason for this is that the organic filler in the liquid crystal sealing agent is deformed during the manufacturing process of the liquid crystal display panel.

In the liquid crystal sealing agent, organic particles having an average particle diameter of more than 1 μm and less than 5 μm can be contained within a range that does not impair the effects of the present invention.

(3) Regarding the radical polymerization initiator, the liquid crystal sealing agent contains photoradicals for photohardening reaction of (1a) (meth)acrylic resin or (1b) (meth)acrylic acid modified epoxy resin. A polymerization initiator or a thermal radical polymerization initiator for performing a thermosetting reaction.

A photoradical polymerization initiator can be used by a known one. Examples of the photoradical polymerization initiator include an alkylphenone compound, a mercaptophosphine oxide compound, a titanocene compound, an oxime ester compound, a benzoin compound, an acetophenone compound, and a diphenyl group. a ketone compound, a thioxanthone compound, an α-oxime ester compound, a phenylglyoxylate compound, a benzoin compound, an azo compound, a diphenyl sulfide compound, or an organic dye system A compound, an iron-phthalocyanine compound, a benzoin ether compound, an anthraquinone compound, or the like.

Examples of the alkylphenone compound include: benzyldimethylketal such as 2,2-dimethoxy-1,2-diphenylethane-1-one (IRGACURE 651) α-Aminoalkylphenone such as 2-methyl-2-morpholinyl(4-thiomethylphenyl)propan-1-one (IRGACURE 907); 1-hydroxy-cyclohexyl An α-hydroxyalkylphenone or the like such as a phenyl-ketone (IRGACURE 184). Examples of the fluorenylphosphine oxide-based compound include 2,4,6-trimethylbenzimidyl-diphenyl-phosphine oxide and the like. The ferrocene-based compound contains bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium Wait. Examples of the oxime ester compound include 1,2-octanedione-1-[4-(phenylthio)-2-(O-benzylidene fluorenyl)] (IRGACURE OXE 01) and the like.

Examples of the thermal radical polymerization initiator include an organic peroxide compound or an azo compound. The thermal radical polymerization initiator is preferably one in which the lower limit of the 10-hour half-life temperature is 80 ° C and the upper limit is 150 ° C.

Specific examples of the organic peroxide compound include a ketone peroxide compound such as methyl ethyl ketone peroxide; and a peroxy ketal compound such as 1,1-di(t-butoxy)cyclohexane. An alkyl peroxy ester compound such as a third butyl peroxypivalate; a dimercapto peroxide compound such as a dilauroyl peroxide; (2-ethylhexyl) peroxydicarbonate; a peroxydicarbonate compound; a peroxycarbonate compound such as a third butyl peroxy isopropyl carbonate; a dialkyl peroxide compound such as a ditributyl peroxide; a third amyl hydrogen A hydroperoxide compound such as a peroxide.

Specific examples of the azo compound include: 1,1'-azobis(2,4-cyclohexane)-1-carbonitrile, 2,2'-azobis[(2-imidazolin-2-yl) a water-soluble azo compound such as propane]disulfate dihydrate; an oil-soluble azo compound such as 1-[(cyano-1-methyl)azo]carbamamine; a polymer azo compound.

The content of the radical polymerization initiator in the liquid crystal sealing agent is preferably 100 parts by mass based on the total of the (1a) (meth)acrylic resin and the (1b) (meth)acrylic modified epoxy resin, that is, 100 parts by mass of the resin unit. 0.01 parts by mass to 3.0 parts by mass. When the content of the radical polymerization initiator is 0.01 parts by mass or more, the curability of the liquid crystal sealing agent becomes good. On the other hand, when the content is 3.0 parts by mass or less, the stability at the time of coating on a substrate becomes good.

(4) Regarding the epoxy hardener As described above, the liquid crystal sealant may also contain an epoxy hardener. In the epoxy curing agent of the present invention, even if it is mixed with an epoxy resin, the epoxy resin is not cured in a state in which the resin is normally stored (at room temperature or under visible light, etc.), but if heat is applied, A hardener that hardens an epoxy resin. The liquid crystal sealing agent containing an epoxy hardening agent is excellent in storage stability, and is excellent in thermosetting property.

The epoxy hardening agent can be a known one, and it is not only the viscosity stability of the liquid crystal sealing agent but also the heat curing temperature, but the melting point is 50° C. or higher and 250° C. The epoxy curing agent is preferably an epoxy curing agent having a melting point of 100 ° C or more and 200 ° C or less, and more preferably an epoxy curing agent having a melting point of 150 ° C or more and 200 ° C or less.

Preferred examples of such an epoxy curing agent include an organic acid diterpenoid compound, an imidazole compound, a dicyandiamide compound, and a polyamine compound.

Examples of the organic acid diterpenoid compound include: diammonium adipate (melting point: 181 ° C), 1,3-bis(decylcarbonylethyl)-5-isopropylhydantoin (melting point is 120 ° C), 7,11-octadecane-1,18-dicarbenium (melting point 160 ° C), dodecanedioxane (melting point 190 ° C), and didecyl sebacate肼 (melting point is 189 ° C) and the like. Examples of the imidazole-based compound include: 2,4-diamino-6-[2'-ethylimidazolyl-(1')]-ethyltriazine (melting point: 215 ° C to 225 ° C), and 2- Phenyl imidazole (melting point: 137 ° C to 147 ° C) and the like. Examples of the dicyandiamide compound include dicyanodiamide (melting point: 209 ° C) and the like. The polyamine compound is a thermal latent curing agent having a polymer structure obtained by reacting an amine with an epoxy, and specific examples thereof include: Adeka Hardener manufactured by ADEKA Co., Ltd. (Adeka Hardener) EH4339S (softening point: 120 ° C to 130 ° C), and Adeka Hardener EH4357S (softening point: 73 ° C to 83 ° C) manufactured by ADEKA Co., Ltd. The liquid crystal sealing agent may contain only one type of the curing agents, or may contain two or more types.

The content of the epoxy hardener in the liquid crystal sealing agent is preferably 3 mass, based on 100 parts by mass of the resin unit, which is a combination of (1a) (meth)acrylic resin and (1b) (meth)acrylic modified epoxy resin. Parts to 30 parts by mass. The liquid crystal sealing agent containing an epoxy hardener can be a so-called one-liquid hardening resin composition. Since the one-liquid curable resin composition does not need to be mixed with the curing agent at the time of use, it is excellent in workability.

(5) Inorganic filler The liquid crystal sealing agent of the present invention may further contain an inorganic filler. By adding an inorganic filler, it is possible to control the viscosity of the liquid crystal sealing agent, the strength of the cured product, and the control of the linear expansion property.

The inorganic filler is not particularly limited, and examples thereof include: calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum niobate, zirconium silicate, iron oxide, titanium oxide, aluminum oxide (alumina), zinc oxide. Inorganic fillers such as cerium oxide, potassium titanate, kaolin, talc, glass beads, sericite activated clay, bentonite, aluminum nitride, tantalum nitride, etc., preferably cerium oxide and talc.

The shape of the inorganic filler is not particularly limited, and may be any of a fixed shape such as a spherical shape, a plate shape, and a needle shape, or an irregular shape. The inorganic filler preferably has an average primary particle diameter of 1.5 μm or less, and preferably has a specific surface area of 0.5 m ² /g to 20 m ² /g. The average primary particle diameter of the inorganic filler can be measured by a laser diffraction method described in JIS Z8825-1. Further, the specific surface area measurement can be measured by the Brunauer-Emmett-Teller method (BET method) described in JIS Z8830.

The content of the inorganic filler in the liquid crystal sealing agent is preferably 3 parts by mass based on 100 parts by mass of the resin unit, which is a total of (1a) (meth)acrylic resin and (1b) (meth)acrylic modified epoxy resin. 30 parts by mass.

(6) Epoxy resin An epoxy resin may also be included in the liquid crystal sealing agent. The epoxy resin has low solubility and diffusibility to liquid crystals, and the display characteristics of the obtained liquid crystal panel are good, and the moisture resistance of the cured product can be improved.

Such an epoxy resin may be an aromatic epoxy resin having a weight average molecular weight of 500 to 10,000, preferably 1,000 to 5,000. The weight average molecular weight of the epoxy resin can be measured, for example, by gel permeation chromatography (GPC) (in terms of polystyrene).

Examples of such an aromatic epoxy resin include aromatic diols represented by bisphenol A, bisphenol S, bisphenol F, bisphenol AD, or the like, or ethylene glycol by using the compounds. An aromatic polyglycidyl ether compound obtained by reacting a diol which is modified with propylene glycol and an alkylene glycol with epichlorohydrin; a novolac resin derived from phenol or cresol and formaldehyde, or a polyphenol A novolac type polyglycidyl ether compound obtained by a reaction of a polyphenol represented by an alkenylphenol or a copolymer thereof with epichlorohydrin; a glycidyl ether compound of a xylylene phenol resin;

Wherein, the aromatic epoxy resin is preferably: cresol novolak type epoxy resin, phenol novolac type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, trisphenol methane type Epoxy resin, trisyl alcohol type epoxy resin, trisphenol type epoxy resin, dicyclopentadiene type epoxy resin, diphenyl ether type epoxy resin, biphenyl type epoxy resin. Further, these resins may be used in combination.

The content of the epoxy resin is preferably from 3 parts by mass to 30 parts by mass based on 100 parts by mass of the total of the (1a) (meth)acrylic resin and the (1b) (meth)acrylic acid-modified epoxy resin. When the content of the epoxy resin is too large, the viscosity of the liquid crystal sealing agent is increased, and the coating property is lowered. When the content of the epoxy resin is too small, the moisture resistance of the cured product of the liquid crystal sealing agent may be insufficient. . The epoxy resin may be in the form of a liquid or a solid. In the case of a solid epoxy resin, the softening point is preferably 40 ° C or more and 150 ° C or less.

(7) Sunscreen The liquid crystal sealant may contain a light-shielding agent for the purpose of imparting a function as a light-shielding portion to the sealing member. When the light shielding agent is contained in the liquid crystal sealing agent, the sealing member has a function as a light shielding portion of the liquid crystal panel. The opacifier may be, for example, a black pigment or a black dye or the like. Examples thereof include carbon black, chromium oxide, iron oxide, titanium black, aniline black, and organic pigments.

The shape of the light-shielding agent is not particularly limited, and may be any of a fixed shape such as a spherical shape, a plate shape, and a needle shape, or an irregular shape. The opacifier preferably has an average primary particle diameter of 1.0 μm or less. The average primary particle diameter of the inorganic filler can be measured by a laser diffraction method described in JIS Z8825-1.

The content of the light-shielding agent is preferably from 3 parts by mass to 30 parts by mass based on 100 parts by mass of the total of the (1a) (meth)acrylic resin and the (1b) (meth)acrylic acid-modified epoxy resin. When the content of the light-shielding agent is too large, the viscosity of the liquid crystal sealing agent is increased, and the coatability is lowered. When the amount of the light-shielding agent is too small, the light-shielding property of the sealing member may be insufficient.

(8) In the liquid crystal sealing agent of other components, a coupling agent such as a thermal radical polymerization initiator or a decane coupling agent, an ion trapping agent, an ion exchanger, a leveling agent, a pigment, a dye, and a plasticizing agent may be further included as needed. Additives such as agents and defoamers. Further, in order to adjust the gap of the liquid crystal panel, a spacer or the like may be prepared.

The viscosity of the E-type viscometer of the liquid crystal sealing agent of the present invention at 25 ° C and 2.5 rpm is preferably 200 Pa·s to 450 Pa·s, more preferably 300 Pa·s to 400 Pa·s. When the viscosity is within the above range, when the substrate of the liquid crystal cell is overlapped with the substrate, the liquid crystal sealing agent is easily deformed into a predetermined shape. Therefore, the gap width between the substrate of the liquid crystal cell and the substrate can be appropriately controlled.

In addition, the liquid crystal sealing agent of the present invention has a thixotropic index (TI (thixotropy index value) of preferably 1.0 to 1.5, more preferably 1.1 to 1.3. The TI value is measured by the viscosity η1 of the liquid crystal sealing agent at room temperature (25 ° C) and 0.5 rpm, and the viscosity η2 of the liquid crystal sealing agent at 5 rpm, and the measured values are applied to the following formula ( 1) The value obtained. TI value = (viscosity η1 (25 ° C) at 0.5 rpm) / (viscosity η 2 (25 ° C) at 5 rpm)...(1)

The liquid crystal sealing agent of the present invention is preferably a liquid crystal sealing agent for a liquid crystal dropping process which is often used for photohardening and thermal hardening.

2. Method of Manufacturing Liquid Crystal Display Panel A liquid crystal display panel produced by the method of the present invention includes a display substrate, a counter substrate paired therewith, and a frame-shaped sealing member interposed between the display substrate and the counter substrate, for display A liquid crystal layer filled in a space surrounded by the sealing member between the substrate and the opposite substrate. In the method of the present invention, the cured product of the liquid crystal sealing agent is used as a sealing member.

Both the display substrate and the opposite substrate are transparent substrates. The material of the transparent substrate may be glass or polycarbonate, polyethylene terephthalate, polyether oxime or polymethyl methacrylate (PMMA).

A matrix-shaped thin film transistor (TFT), a color filter, a black matrix, or the like can be disposed on the surface of the display substrate or the counter substrate. An alignment film is formed on the surface of the display substrate or the opposite substrate. The alignment film contains a known organic alignment agent or inorganic alignment agent.

Such a liquid crystal display panel can be manufactured using the liquid crystal sealing agent of the present invention. The manufacturing method of the liquid crystal display panel generally includes a liquid crystal dropping process and a liquid crystal injection process, but the method of manufacturing the liquid crystal display panel of the present invention is preferably a liquid crystal dropping process.

The manufacturing method of the liquid crystal display panel using the liquid crystal dropping process comprises: a1) a first step of forming a sealing pattern of the liquid crystal sealing agent of the present invention on one of the substrates; a2) in a state where the sealing pattern is uncured, on the substrate a second step of dropping liquid crystal in a region surrounded by the seal pattern or another substrate facing the region surrounded by the seal pattern; a3) overlapping one of the substrates with the other substrate via the seal pattern Three steps; and a4) a fourth step of hardening the seal pattern.

The so-called seal pattern in the step a2) is in an unhardened state, and means that the hardening reaction of the liquid crystal sealing agent does not proceed to the gelation point. Therefore, in the step a2), in order to suppress the dissolution of the liquid crystal sealing agent in the liquid crystal, the sealing pattern may be light-irradiated or heated to be semi-hardened. One of the substrates and the other of the substrates are respectively a display substrate or a counter substrate.

When the substrates are overlapped in the step a3), the organic filler A having a relatively large average particle diameter contained in the liquid crystal sealing agent is reversibly or irreversibly deformed. The so-called deformation refers to crushing, crushing, and the like. That is, the organic filler A in the liquid crystal sealing agent is preferably spherical; on the other hand, the organic filler A in the liquid crystal sealing of the liquid crystal display panel does not have to be spherical but is crushed.

As described above, in the liquid crystal sealing agent of the present invention, since the organic filler B having a relatively small average particle diameter is contained, even if the width of the sealing pattern is made thin, it is easy to uniformly apply the liquid crystal sealing agent. The line width of the seal pattern is preferably from 0.2 mm to 1.0 mm, more preferably from 0.2 mm to 0.7 mm.

Further, when the liquid crystal sealing agent of the present invention is formed into a sealing member, the organic filler A is crushed, thereby effectively suppressing leakage of the liquid crystal. In addition, the bonding strength between the substrates is improved. On the other hand, since the liquid crystal sealing agent contains the organic filler B having a relatively small average particle diameter, even if the width of the sealing member is small, the line width is likely to be uniform, and it is difficult to locally generate a portion having low strength.

Further, since the ratio of the organic filler A and the organic filler B contained in the liquid crystal sealing agent is within a predetermined range, the viscosity of the liquid crystal sealing agent is moderately low. Therefore, when the substrates of the liquid crystal cells are overlapped with each other, it is easy to appropriately control the gap width between the substrates.

In the step a4), only hardening by heating or hardening (pre-curing) by light irradiation may be performed, and then hardening by heating (formal hardening) may be performed. The liquid crystal sealing agent is instantly hardened by pre-hardening by light irradiation, whereby dissolution in the liquid crystal can be suppressed.

The light irradiation time depends on the composition of the liquid crystal sealing agent, for example, about 10 minutes. The light irradiation energy may be any energy that can harden a (meth)acrylic resin or a (meth)acrylic acid-modified epoxy resin. The light is preferably ultraviolet light. The heat hardening temperature depends on the composition of the liquid crystal sealing agent, for example, 120 ° C, and the heat hardening time is about 2 hours.

The liquid crystal display panel of the present invention provides a high-quality display device because the liquid crystal leakage is suppressed and the adhesion strength between the substrate and the sealing member is high. Example

Prepare the following resin components. (1) Resin (1a) 2-functional acrylic resin: bisphenol A type epoxy resin modified diacrylate (3002A, manufactured by Kyoeisha Chemical Co., Ltd., hydrogen-binding functional group equivalent of 3.3 × 10 ^-3 ) ( 1b) Acrylic modified epoxy resin: An acrylic modified epoxy resin prepared by the following method was used. (Preparation method) In a 500 mL four-necked flask equipped with a stirrer, a gas introduction tube, a thermometer, and a cooling tube, 160 g of a bisphenol F-type epoxy resin (EXA-835LV, manufactured by Diane Health Co., Ltd.) was added. 36 g of acrylic acid and 0.2 g of triethanolamine were heated and stirred at 110 ° C for 5 hours under a dry air stream to obtain an acrylic modified epoxy resin. The obtained acrylic modified epoxy resin was washed 12 times with ultrapure water. The acrylic acid-modified epoxy resin had a hydrogen-bonding functional group equivalent of 2.1 × 10 ^-3 .

(2) Organic filler A: (2-1) GBM-55S (crosslinked polybutyl acrylate-methyl methacrylate graft copolymer, manufactured by Aica Industries, with an average particle size of 6 μm) 2-2) P-800T (urethane powder, manufactured by Gensal Industries, Inc., average particle size 7 μm) (2-3) KMP600 (anthraquinone rubber powder, manufactured by Shin-Etsu Chemical Co., Ltd., average Particle size 5 μm) (2-4) SE-006T (acrylic powder, manufactured by Gensal Industries, Inc., average particle size 6 μm)

(3) Organic filler B: F351 (alkyl methacrylate copolymer, manufactured by Aica Industries, with an average particle diameter of 0.3 μm)

(4) Radical polymerization initiator (4-1) Thermal radical polymerization initiator: 1,1'-azobis(2,4-cyclohexane-1-carbonitrile (V-40: and pure light) (Manufactured by Pharmaceutical Industry Co., Ltd.) (4-2) Photoradical polymerization initiator: 2,2-dimethoxy-1,2-diphenylethane-1-one (IRGACURE 651) :Manufactured by BASF

·Other inorganic fillers: KE-S30 (spherical cerium oxide, manufactured by Nippon Shokubai Co., Ltd., average particle size 0.24 μm, maximum particle size 0.9 μm) Epoxy resin: Epiclon 850 CRP (bisphenol A) Epoxy resin: manufactured by Di Ai Sheng (DIC)) Epoxy hardener (thermal latent hardener): 1,3-bis(decylcarbonylethyl)-5-isopropylhydantoin (Ami Amicure VHD, manufactured by Ajinomoto Co., Ltd. Additive: γ-glycidoxypropyltrimethoxydecane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.)

[Example 1] Using a three-roller, 70 parts by mass of a bifunctional acrylic resin, 15 parts by mass of an organic filler A (2-1), and 5 parts by mass of an organic filler B were added so that the liquid composition became uniform. 1 part by mass of the thermal radical polymerization initiator (4-1), 5 parts by mass of the epoxy resin, 3 parts by mass of the thermal latent curing agent, and 1 part by mass of the resin composition of the additive are sufficiently mixed to obtain a liquid crystal Sealants.

[Examples 2 to 14 and Comparative Examples 1 to 9] Liquid crystal sealing agents were obtained in the same manner as in Example 1 in the compositions (mass ratios) described in Tables 1 and 2.

[Method for Evaluating Liquid Crystal Sealant] The following items were evaluated for the liquid crystal sealing agents obtained in the respective Examples and Comparative Examples.

1) Viscosity The viscosity of the obtained liquid crystal sealing agent was measured at 25 ° C at 1.0 rpm and 2.5 rpm using an E-type viscometer.

2) Thix index (TI value) The viscosity η2 of the liquid crystal sealing agent at room temperature (25 ° C), liquid crystal sealing agent at 0.5 rpm, and liquid crystal sealing agent at 5 rpm was measured using an E-type viscometer. These measured values are applied to the following formula (1) to determine the TI value. TI value = (viscosity η1 (25 ° C) at 0.5 rpm) / (viscosity η 2 (25 ° C) at 5 rpm)...(1)

3) Bonding strength The liquid crystal sealant was printed on a 25 mm × 45 mm × 5 mm thick alkali-free glass using a screen plate. The seal pattern is set to a circular shape with a diameter of 1 mm. Next, the paired alkali-free glass was placed in a seal pattern and fixed by a jig.

Further, the liquid crystal sealing agents of Example 6, Example 7, Comparative Example 4, and Comparative Example 5 were irradiated with a UV-ray irradiation apparatus (manufactured by Ushio Electric Co., Ltd.) to a test piece fixed by a jig at 100 mW/cm. ² ultraviolet rays harden the liquid crystal sealant. At this time, the illuminance energy of the ultraviolet ray was set to 2000 mJ/cm ² . A test piece obtained by curing the liquid crystal sealing agent by light was subjected to heat treatment at 120 ° C for 60 minutes in an oven to prepare a sample for measuring the adhesion strength.

On the other hand, the liquid crystal sealing agents of Examples 1 to 5, Examples 8 to 14, Comparative Examples 1 to 3, and Comparative Examples 6 to 9 were fixed by a jig using an oven. The test piece was subjected to heat treatment at 120 ° C for 60 minutes to prepare a sample for measuring the adhesion strength.

Next, using a tensile tester (manufactured by Intesco Co., Ltd.), the stretching speed was set to 2 mm/min, and the cured liquid crystal sealing agent was peeled off in a direction parallel to the bottom surface of the glass. This measures the plane tensile strength. Here, the bonding strength was evaluated in the following manner in accordance with the magnitude of the plane tensile strength in four levels. ◎: The tensile strength is 30 MPa or more, and the bonding strength is very good. ○: The tensile strength is 25 MPa or more and less than 30 MPa, and the bonding strength is good. Δ: The tensile strength is 20 MPa or more and less than 25 MPa. Good ×: tensile strength is less than 20 MPa, low bonding strength

4) Evaluation method of the gap control of the panel Further, 1 part by mass of a spherical spacer of 5 μm was further added to the liquid crystal sealing agent of each of the examples and the comparative examples. The obtained composition was filled in a dispenser (manufactured by Hitachi Plant Technology Co., Ltd.) and depicted on a substrate of 40 mm × 50 mm × 0.7 mm thick alkali-free glass with a cross-sectional area of 3,500 μm ² A square frame seal of 35 mm × 40 mm and a line width of 0.7 mm. In the sealing pattern of the substrate, a liquid crystal material equivalent to the amount of the panel after lamination is precisely dropped by a dispenser (manufactured by Hitachi Industrial Equipment Co., Ltd.) (MLC-11900-000: Merck) . Then, the glass substrate and the opposite glass substrate were superposed under a reduced pressure of 10 Pa·s by a vacuum bonding apparatus (manufactured by Shin-Etsu Engineering Co., Ltd.), and a load was applied thereto to fix it.

Further, in Example 6, Example 7, Comparative Example 4, and Comparative Example 5, ultraviolet rays of 100 mW/cm ² were irradiated to the sample after the fixation by an ultraviolet irradiation device (manufactured by Ushio Electric Co., Ltd.) to make a liquid crystal. The sealant hardens. At this time, the illuminance energy of the ultraviolet ray was set to 2000 mJ/cm ² . After the liquid crystal sealing agent was cured by light, the liquid crystal display panel was produced by performing heat treatment at 120 ° C for 60 minutes in an oven.

On the other hand, in Examples 1 to 5, Examples 8 to 14, Comparative Example 1 to Comparative Example 3, and Comparative Example 6 to Comparative Example 9, the fixed sample was subjected to 120 ° C and 60 in an oven. The liquid crystal display panel was produced by heat treatment in minutes.

Next, the distribution (in-plane distribution) of the gap in the main seal of the sample was measured by a cell gap inspection device (manufactured by Otsuka Electronics Co., Ltd.), and evaluated based on the following criteria. ×: When either or both of the maximum value and the minimum value of the gap are not in the range of 5 μm ± 0.2 μm Δ: Although both the maximum value and the minimum value of the gap are in the range of 5 μm ± 0.20 μm, However, at least one or both of them are not in the range of 5 μm ± 0.15 μm. ○: Although both the maximum value and the minimum value of the gap are in the range of 5 μm ± 0.15 μm, at least one or both When it is not in the range of 5 μm ± 0.10 μm ◎: The case where both the maximum value and the minimum value of the gap are in the range of 5 μm ± 0.10 μm

5) Leakage resistance 1 part by mass of a 5 μm spherical spacer was further added to the liquid crystal sealing agents of the respective Examples and Comparative Examples. The obtained composition was filled in a dispenser (manufactured by Hitachi Industrial Equipment Technology Co., Ltd.) on a substrate of 40 mm × 50 mm × 0.7 mm thick alkali-free glass, and a cross-sectional area of 3500 μm ^{2 was} used to describe 35 mm × 40 A square frame seal with a mm and a line width of 0.7 mm. In the sealing pattern of the substrate, a liquid crystal material equivalent to the amount of the panel after lamination is precisely dropped by a dispenser (manufactured by Hitachi Industrial Equipment Co., Ltd.) (MLC-11900-000: Merck) . The glass substrate was superposed on the opposite glass substrate under a reduced pressure of 10 Pa·s by a vacuum bonding apparatus (manufactured by Shin-Etsu Engineering Co., Ltd.), and a load was applied thereto to fix it.

Subsequently, after releasing to atmospheric pressure, it was left at room temperature, and the time until the liquid crystal in the panel leaked to the outside was measured. Further, the penetration of the liquid crystal into the seal pattern was observed with an optical microscope. Leakage resistance was determined in four levels based on the following criteria. ◎: After being released to atmospheric pressure, even if it was left for 10 minutes or more, the liquid crystal did not leak, and no penetration of liquid crystal into the sealant was observed. ○: After being released to atmospheric pressure, the liquid crystal did not leak even after being left for 10 minutes or more, but it was observed. Infiltration of liquid crystal into the sealant Δ: when the standing time after release to atmospheric pressure is 5 minutes or more and less than 10 minutes, the liquid crystal leaks out ×: when the standing time after release to atmospheric pressure is 5 minutes, the liquid crystal leaks out

6) Sealing linearity In the liquid crystal sealing agent of each of the examples and the comparative examples, 1 part by mass of a spherical spacer of 5 μm was further added, and a liquid crystal sealing agent to which a spacer was added was adjusted. The obtained composition was filled in a dispenser (manufactured by Hitachi Industrial Equipment Technology Co., Ltd.) on a substrate of 40 mm × 50 mm × 0.7 mm thick alkali-free glass, and a cross-sectional area of 3500 μm ^{2 was} used to describe 35 mm × 40 A square frame seal with a mm and a line width of 0.7 mm. In the sealing pattern of the substrate, a liquid crystal material equivalent to the amount of the panel after lamination is precisely dropped by a dispenser (manufactured by Hitachi Industrial Equipment Co., Ltd.) (MLC-11900-000: Merck) . The glass substrate was superposed on the opposite glass substrate under a reduced pressure of 10 Pa·s by a vacuum bonding apparatus (manufactured by Shin-Etsu Engineering Co., Ltd.), and a load was applied thereto to fix it.

Immediately after the release to atmospheric pressure, the following treatment was performed. In Example 6, Example 7, Comparative Example 4, and Comparative Example 5, ultraviolet rays of 100 mW/cm ² were irradiated to the fixed sample by an ultraviolet irradiation device (manufactured by Ushio Electric Co., Ltd.) to make a liquid crystal sealing agent. hardening. At this time, the illuminance energy of the ultraviolet ray was set to 2000 mJ/cm ² . The liquid crystal sealing agent was cured by light, and then heat-treated at 120 ° C for 60 minutes in an oven to prepare a liquid crystal display panel. On the other hand, in Examples 1 to 5, Examples 8 to 14, Comparative Example 1 to Comparative Example 3, and Comparative Example 6 to Comparative Example 9, an immobilized sample was subjected to 120 ° C and 60 using an oven. A minute of heat treatment to produce a liquid crystal display panel.

With respect to the completed liquid crystal display panel, the line width of the sealing member (sealing pattern) was measured using an optical microscope. Moreover, regarding the uniformity of the line width, evaluation was performed in the following manner. ×: When either or both of the maximum value and the minimum value of the line width are within ±20% of the average value of the line width ○: The average of the line width is the maximum value and the minimum value of the line width. Within ±20% of the value, but either or both are ±10% or more of the average value of the line width. ◎: The maximum value of the line width and the minimum value are less than ±10% of the average value of the line width. Situation within the scope

The compositions and evaluation results of the liquid crystal sealing agents of the respective examples and comparative examples are summarized in Tables 1 and 2.

[Table 1]

[Table 2]

As shown in Table 1, in the liquid crystal sealing agent, a filler A having a relatively large particle diameter and a filler B having a relatively small particle diameter are contained at a predetermined ratio (0.25 ≦ W1/(W1 + W2) ≦ 0.75), and the liquid crystal is liquid. The sealing has high bonding strength and excellent leakage resistance. Further, the gap control of the panel or the sealing linearity was also well evaluated (Examples 1 to 14).

On the other hand, as shown in Table 2, when the liquid crystal sealing agent contains only the filler A, if the amount of the filler A is large (35 mass%), the sealing linearity is lowered, and the bonding strength is also less than 25 MPa (comparison example 1). It is presumed that due to the filler A, the width of the seal pattern becomes uneven, and the adhesive strength is locally lowered. On the other hand, when the liquid crystal sealing agent contains only the filler A and the amount of the filler A is small (10% by mass), the adhesive strength is less than 20 MPa, and the leakage resistance is also low (Comparative Example 2). It is presumed that since the filler A is small, the width of the seal pattern becomes uniform, but the leakage of the liquid crystal cannot be sufficiently suppressed.

In addition, when the filler A and the filler B are combined, when the ratio of the filler A is too large, the line width of the seal pattern becomes uneven, and the leakage resistance is low (Comparative Example 3 to Comparative Example 5 and Comparative Example 7). It is presumed that the strength of the seal pattern is locally lowered. On the other hand, when the ratio of the filler B is too large, the sealing linearity is lowered and the leakage resistance is also low (Comparative Example 6 and Comparative Example 8). It is presumed that the gap between the substrates cannot be sufficiently filled by the filler A, and the leakage resistance is lowered. Further, it is presumed that the liquid crystal sealing agent is difficult to uniformly diffuse due to the increase in the TI value due to the filler B, and thus the sealing linearity is lowered. In addition, it is presumed that the gap control of the panel is also low for the same reason. Further, in the case where the inorganic filler having the same sheet metal particle diameter was contained instead of the organic filler B (Comparative Example 8), the adhesive strength was low and the leakage resistance was low. It is presumed that since the inorganic filler is hard compared with the organic filler B, it is difficult for the seal pattern to adhere to the substrate, and it is difficult to sufficiently improve the adhesion strength.

The priority of Japanese Patent Application No. 2014-150615 filed on Jul. 24, 2014 is hereby incorporated by reference. The contents described in the specification of the application are all incorporated in the specification of the present application. [Industrial availability]

The present invention relates to a liquid crystal sealing agent capable of suppressing leakage of a liquid crystal even when the sealing pattern is thinned, and capable of forming a sealing member having a high bonding strength between the sealing member and the substrate, and providing high quality according to the liquid crystal sealing agent. Liquid crystal display device.

no

no

no

Claims (11)

A liquid crystal sealing agent comprising: (1a) a (meth)acrylic resin or (1b) a (meth)acrylic modified epoxy resin having an epoxy group and a (meth)acrylic group in the molecule, (2) An organic filler A having an average particle diameter of 4 μm to 13 μm, (3) an organic filler B having an average particle diameter of 0.05 μm to 1 μm, and (4) a radical polymerization initiator, and when the component (2) The content (mass) of the component (W) is W1, and when the content (mass) of the component (3) is W2, 0.25 ≦ W1/(W1 + W2) ≦ 0.75. The liquid crystal sealing agent according to claim 1, wherein the W1 and the W2 satisfy the following formula: 0.4≦W1/(W1+W2)≦0.6. The liquid crystal sealing agent according to claim 1, wherein the component (2) and the component (the component (2) and the component (100 parts by mass) of the resin unit in which the component (1a) and the component (1b) are combined are The total amount of 3) is from 20 parts by mass to 100 parts by mass. The liquid crystal sealing agent according to claim 1, wherein the component (2) and the component (3) are respectively selected from the group consisting of an anthrone microparticle, an acrylic microparticle, a styrene microparticle, and a polyolefin microparticle. More than one type of microparticles in the group. The liquid crystal sealing agent according to claim 1, wherein the content of the component (4) is 0.01 mass with respect to 100 parts by mass of the resin unit in which the component (1a) and the component (1b) are combined. Parts to 3.0 parts by mass. The liquid crystal sealing agent according to claim 1, further comprising (5) an epoxy curing agent, and 100 parts by mass of the resin unit in which the component (1a) and the component (1b) are combined, The content of the component (5) is from 3 parts by mass to 30 parts by mass. The liquid crystal sealing agent according to claim 1, which further comprises (6) an inorganic filler, and the component is 100 parts by mass relative to the resin unit in which the component (1a) and the (1b) are combined. The content of (6) is from 3 parts by mass to 30 parts by mass. The liquid crystal sealing agent according to claim 1, which further comprises (7) an opacifier, and the component is (100 parts by mass) with respect to the resin unit in which the (1a) and the (1b) are combined. The content of 7) is from 3 parts by mass to 30 parts by mass. The liquid crystal sealing agent according to claim 1, wherein the viscosity at 25 ° C and 2.5 rpm measured by an E-type viscosity meter is 200 Pa·s to 450 Pa·s. The liquid crystal sealing agent according to claim 1, which is used for manufacturing a liquid crystal display panel by a liquid crystal dropping process. A method of manufacturing a liquid crystal display panel, comprising: using a liquid crystal sealing agent according to claim 1 to form a sealing pattern on one of the substrates; and in a state in which the sealing pattern is not hardened, a step of dropping liquid crystal in a sealing pattern region of one of the substrates or another substrate paired with the one of the substrates; a step of overlapping the one of the substrates with the other substrate; The step of hardening the seal pattern.