TWI813685B - Sealant for liquid crystal display element, upper and lower conduction material, and liquid crystal display element - Google Patents

Abstract

An object of the present invention is to provide a sealant for a liquid crystal display element that can suppress insertion of liquid crystal into the sealant or contamination of the liquid crystal caused by the sealant, has excellent adhesion, and can obtain a liquid crystal display element with excellent display performance. Furthermore, an object of the present invention is to provide an upper and lower conductive material and a liquid crystal display element using the sealant for liquid crystal display elements. The present invention is a sealant for liquid crystal display elements, which contains a curable resin, a thermosetting agent, and soft particles with a maximum particle diameter of more than 100% of the cell gap of the liquid crystal display element. The curable resin contains a molecule having Compounds with more than 3 epoxy groups.

Description

Sealants for liquid crystal display elements, upper and lower conductive materials, and liquid crystal display elements

The present invention relates to a sealant for a liquid crystal display element that can suppress the insertion of liquid crystal into the sealant or the contamination of the liquid crystal caused by the sealant, and can obtain a liquid crystal display element with excellent adhesion and excellent display performance. Furthermore, the present invention relates to an upper and lower conductive material and a liquid crystal display element using the sealant for liquid crystal display elements.

In recent years, as methods for manufacturing liquid crystal display elements such as liquid crystal display units, from the viewpoints of shortening the takt time and optimizing the amount of liquid crystal used, as disclosed in Patent Document 1 and Patent Document 2, The liquid crystal dripping method using sealant is called the dripping method. In the dropping method, first, a sealant is applied to one of two transparent substrates with electrodes to form a frame-shaped sealing pattern. Secondly, while the sealant is not yet hardened, tiny droplets of liquid crystal are dropped onto the entire surface of the frame of the sealing pattern, and another transparent substrate is immediately attached to it. The sealing part is irradiated with light such as ultraviolet rays or heated to harden the sealant. , thereby producing liquid crystal display elements. If the substrates are bonded under reduced pressure, liquid crystal display elements can be manufactured with extremely high efficiency. Currently, the dropping method is becoming the mainstream method of manufacturing liquid crystal display elements.

However, in today's era when various mobile devices equipped with LCD panels such as mobile phones and portable game consoles are widespread, miniaturization of devices is the most required issue. As a method of miniaturization, there is a narrow edge of the liquid crystal display part, for example, arranging the position of the sealing part under the black matrix (hereinafter also referred to as "narrow edge design"). However, if a liquid crystal display element with a narrow edge design is manufactured using the dropping method, there may be a situation where the sealant is disposed directly under the black matrix, and when the sealant is hardened by light irradiation, the irradiated light is Shielding makes it difficult for light to reach the inside of the sealant, and the hardening of the sealant will become insufficient. If the sealant is not sufficiently hardened in this way, there is a problem that unhardened sealant components will dissolve into the liquid crystal and contamination of the liquid crystal will easily occur.

Therefore, studies have been conducted on curing the sealant by heat alone. However, if curing by light irradiation is not performed, the liquid crystal may flow during heating and be inserted into the sealant portion during curing, resulting in cracking of the sealing pattern or other reasons. The sealant whose viscosity is reduced by heating causes the problem of liquid crystal contamination. Especially in recent years, with the narrow edges of panels, the line width of the sealant to be applied has also narrowed, and the sealing cross-sectional area after lamination has decreased. Therefore, cracking of the sealing pattern etc. becomes easy to occur. [Prior technical literature] [Patent Document]

Patent Document 1: Japanese Patent Application Publication No. 2001-133794 Patent Document 2: International Publication No. 02/092718

[Problem to be solved by the invention]

An object of the present invention is to provide a sealant for a liquid crystal display element that can suppress insertion of liquid crystal into the sealant or contamination of the liquid crystal caused by the sealant, has excellent adhesion, and can obtain a liquid crystal display element with excellent display performance. Furthermore, an object of the present invention is to provide an upper and lower conductive material and a liquid crystal display element using the sealant for liquid crystal display elements. [Technical means to solve the problem]

The present invention is a sealant for liquid crystal display elements, which contains a curable resin, a thermosetting agent, and soft particles with a maximum particle diameter of more than 100% of the cell gap of the liquid crystal display element. The curable resin contains a molecule having Compounds with more than 3 epoxy groups. The present invention is described in detail below.

In recent years, PSA (Polymer Sustained Alignment) type liquid crystal display elements have attracted attention as liquid crystal display elements that can achieve high-speed responsiveness or high contrast. In a PSA type liquid crystal display element, a liquid crystal composition containing a polymerizable compound is used, and the polymerizable compound in the liquid crystal composition is polymerized by irradiating light or the like to the liquid crystal composition filled in the cells of the liquid crystal display element. Concave-convex shapes are formed on the substrate to provide a uniform pretilt angle and control the alignment of liquid crystal molecules. However, there is a problem that when a conventional sealant is used to seal a PSA-type liquid crystal display element, uneven shapes formed on the substrate may vary, and a uniform pretilt angle may not be provided.

The inventors of the present invention believe that the reason why the uneven shape formed on the substrate is uneven when sealing a PSA-type liquid crystal display element using a conventional sealant is due to (methyl), which is a curable resin and is usually contained in the sealant. Acrylic compound. That is, it is considered that the (meth)acrylic acid compound in the curable resin is eluted into the liquid crystal and polymerization of the (meth)acrylic acid compound is also caused when the polymerizable compound in the liquid crystal is polymerized, and the (meth)acrylic acid compound is polymerized The part forms a concave and convex shape that is different from the target shape. Therefore, the present inventors conducted research on sealing PSA type liquid crystal display elements using a sealant that does not contain a (meth)acrylic acid compound or has a reduced content of a (meth)acrylic acid compound. However, when such a sealant is used, There is a problem that liquid crystal is easily inserted into the sealant. Therefore, the present inventors conducted research on suppressing the insertion of liquid crystal into the sealant or the contamination of the liquid crystal caused by the sealant by blending soft particles with a maximum particle diameter of 100% or more of the cell gap of the liquid crystal display element. However, if a large amount of soft particles are blended in order to fully suppress the insertion of liquid crystal into the sealant or the contamination of the liquid crystal by the sealant, there is a problem that the obtained sealant has poor adhesiveness. Therefore, the present inventors further studied the use of a compound having three or more epoxy groups in one molecule as a curable resin. As a result, they found a sealant for a liquid crystal display element that can suppress the insertion of liquid crystal into the sealant or contamination of the liquid crystal caused by the sealant, excellent adhesion and obtain a liquid crystal display element with excellent display performance, and completed the present invention. The effect of the sealant for a liquid crystal display element of the present invention in suppressing the insertion of liquid crystal into the sealant or the contamination of the liquid crystal caused by the sealant is particularly remarkable when the sealant is hardened by heat alone. Furthermore, the sealing compound for liquid crystal display elements of the present invention can be suitably used as a sealing compound for PSA type liquid crystal display elements.

The sealing compound for liquid crystal display elements of the present invention contains curable resin. The above-mentioned curable resin includes a compound having three or more epoxy groups in one molecule (hereinafter also referred to as a "trifunctional or higher epoxy compound"). By making the sealing compound for liquid crystal display elements of the present invention contain the above-mentioned trifunctional or higher epoxy compound, insertion of liquid crystal into the sealing compound can be suppressed, and the obtained liquid crystal display element has excellent display performance.

The above-mentioned trifunctional or higher epoxy compound is preferred in that it has excellent reactivity and can obtain a sealing compound for a liquid crystal display element that is more effective in inhibiting insertion of liquid crystal into the sealing compound or contamination of liquid crystal by the sealing compound. It has more than 6 epoxy groups in one molecule. In addition, in terms of having an excellent effect of inhibiting the insertion of liquid crystal into the sealant, the above-mentioned trifunctional or higher epoxy compound is preferably one having three or more epoxy groups and an isocyanuric skeleton in one molecule. Compounds, and/or glycidylamine-type epoxy compounds having more than three epoxy groups in one molecule. More preferably, it is a compound having three or more epoxy groups and an isocycyanuric acid skeleton in one molecule.

Specific examples of the trifunctional or higher epoxy compound include compounds represented by the following formula (1), compounds represented by the following formula (2), compounds represented by the following formula (3), and the like. . Among them, the compound represented by the following formula (1) and the compound represented by the following formula (2) are preferred, and the compound represented by the following formula (1) is more preferred.

The above-mentioned curable resin may also contain other curable resins in addition to the above-mentioned trifunctional or higher epoxy compounds. When the above-mentioned other curable resin is contained, a preferable lower limit of the content of the above-mentioned trifunctional or higher epoxy compound in 100 parts by weight of the above-mentioned curable resin is 50 parts by weight, and a preferable upper limit is 95 parts by weight. By setting the content of the above-mentioned trifunctional or higher epoxy compound within this range, the obtained sealing compound for a liquid crystal display element has a more excellent effect of suppressing dissolution into liquid crystal and insertion of liquid crystal into the sealing compound. A more preferable lower limit of the content of the above-mentioned trifunctional or higher epoxy compound is 60 parts by weight, and a more preferable upper limit is 90 parts by weight.

As the above-mentioned other curable resin, a monofunctional epoxy compound or a bifunctional epoxy compound can be suitably used.

As the above-mentioned monofunctional epoxy compound or the above-mentioned bifunctional epoxy compound, it is preferable that one molecule of the polyfunctional epoxy compound has one or two epoxy groups obtained by reacting a part of the epoxy group with (meth)acrylic acid. Based on partially (meth)acrylic acid modified epoxy resin (hereinafter also referred to as "partially (meth)acrylic acid modified epoxy resin"). In particular, from the perspective that the obtained sealing compound for liquid crystal display elements has improved rapid hardening properties and has a better effect of inhibiting the insertion of liquid crystal into the sealing compound, it is preferable to use the above-mentioned partially (meth)acrylic modified epoxy. The resin is used in combination with the thermal radical polymerization initiator described below.

Examples of other monofunctional epoxy compounds include allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, and p-tertiary butylbenzene. Glycidyl ether, glycidyl (meth)acrylate, etc. In addition, in this specification, the above-mentioned "(meth)acrylic acid" means acrylic acid or (meth)acrylic acid, and the above-mentioned "(meth)acrylate" means acrylate or methacrylate.

Examples of the other bifunctional epoxy compounds include bisphenol A bifunctional epoxy compounds, bisphenol F bifunctional epoxy compounds, bisphenol S bifunctional epoxy compounds, and 2,2' -Diallyl bisphenol A type bifunctional epoxy compound, hydrogenated bisphenol type bifunctional epoxy compound, propylene oxide addition bisphenol A type bifunctional epoxy compound, resorcinol type bifunctional epoxy compound , biphenyl type bifunctional epoxy compound, sulfide type bifunctional epoxy compound, diphenyl ether type bifunctional epoxy compound, dicyclopentadiene type bifunctional epoxy compound, naphthalene type bifunctional epoxy compound Compounds, glycidylamine type bifunctional epoxy compounds, alkyl polyol type bifunctional epoxy compounds, rubber modified type bifunctional epoxy compounds, bifunctional epoxypropyl ester compounds, etc.

The sealant for liquid crystal display elements of the present invention may also contain a (meth)acrylic compound without an epoxy group as the other curable resin mentioned above to suppress dissolution into the liquid crystal in the case of a PSA type liquid crystal display element. From the viewpoint of adverse effects on the uneven shape, it is preferable not to contain the (meth)acrylic compound which does not have an epoxy group. In addition, in this specification, the above-mentioned "(meth)acrylic acid compound" refers to a compound having a (meth)acrylyl group, and the above-mentioned "(meth)acrylyl group" refers to an acrylyl group or a methacrylyl group. base.

The sealing compound for liquid crystal display elements of the present invention contains a thermosetting agent. Examples of the thermosetting agent include organic acid hydrazides, imidazole derivatives, amine compounds, polyphenol compounds, acid anhydrides, and the like. Among them, organic acid hydrazides can be suitably used. The above-mentioned thermosetting agents may be used alone or in combination of two or more types.

Examples of the organic acid hydrazine include sebacic acid dihydrazide, isophthalic acid dihydrazide, adipic acid dihydrazide, malonic acid dihydrazide, and the like. Examples of commercially available organic acid hydrazides include organic acid hydrazides manufactured by Otsuka Chemical Co., Ltd., organic acid hydrazides manufactured by Ajinomoto Fine-Techno Co., Ltd., and organic acid hydrazides manufactured by Nippon Finechem Co., Ltd. Examples of the organic acid hydrazide manufactured by Otsuka Chemical Co., Ltd. include SDH, ADH, and the like. Examples of the organic acid hydrazides manufactured by Ajinomoto Fine-Techno include Amicure VDH, Amicure VDH-J, Amicure UDH, and Amicure UDH-J. Examples of the organic acid hydrazides manufactured by Japan Finechem include MDH and the like.

The content of the thermosetting agent preferably has a lower limit of 1 part by weight and a preferable upper limit of 50 parts by weight relative to 100 parts by weight of the curable resin. By setting the content of the thermosetting agent within this range, the sealing compound for liquid crystal display elements obtained can be made into one with more excellent thermosetting properties without deteriorating the coating properties and the like. A more preferable upper limit of the content of the thermal hardener is 30 parts by weight.

The sealing compound for liquid crystal display elements of the present invention preferably contains a polymerization initiator. Examples of the polymerization initiator include radical polymerization initiators, cationic polymerization initiators, and the like. Among them, it is preferable to contain a radical polymerization initiator as the above-mentioned polymerization initiator. The rebound of the following soft particles is not only affected by the maximum particle size of the soft particles, but also by the hardening speed of the sealant. Compared with thermal hardeners, the above-mentioned free radical polymerization initiator can significantly increase the curing speed. Therefore, by using it in combination with the above-mentioned soft particles, the rebound that is easily caused by the above-mentioned soft particles can be suppressed, and the liquid crystal obtained The display element has better gap maintaining properties.

Examples of the radical polymerization initiator include a thermal radical polymerization initiator that generates radicals by heating, a photoradical polymerization initiator that generates radicals by light irradiation, and the like. Among them, a thermal radical polymerization initiator is preferred. As described above, in particular, in terms of improving the rapid hardening properties of the obtained sealing compound for liquid crystal display elements and achieving a more excellent effect of inhibiting the insertion of liquid crystal into the sealing compound, it is more preferred to combine the above-mentioned partial (meth)acrylic acid Modified epoxy resin is used in combination with the above-mentioned thermal radical polymerization initiator.

Examples of the thermal radical polymerization initiator include azo compounds, organic peroxides, and the like. Among them, from the viewpoint of suppressing liquid crystal contamination, a initiator composed of an azo compound (hereinafter also referred to as an "azo initiator") is preferred, and a polymeric azo compound is more preferred. Initiator (hereinafter also referred to as "polymer azo initiator"). The above-mentioned thermal radical polymerization initiator may be used alone or in combination of two or more kinds. In addition, in this specification, the above-mentioned "polymer azo compound" refers to a compound that has an azo group and generates free radicals by heat that can react with a (meth)acrylyl group, and has a number average molecular weight of 300 or more. compound.

The preferable lower limit of the number average molecular weight of the above-mentioned polymeric azo compound is 1,000, and the preferable upper limit is 300,000. By setting the number average molecular weight of the polymeric azo compound within this range, adverse effects on liquid crystal can be prevented and the compound can be easily mixed into the curable resin. A more preferable lower limit of the number average molecular weight of the above-mentioned polymeric azo compound is 5,000, a more preferable upper limit is 100,000, a further preferable lower limit is 10,000, and a further preferable upper limit is 90,000. In addition, in this specification, the said number average molecular weight is measured by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent, and it is the value calculated|required by polystyrene conversion. Examples of a column for measuring the number average molecular weight in terms of polystyrene by GPC include Shodex LF-804 (manufactured by Showa Denko Co., Ltd.).

Examples of the polymer azo compound include those having a structure in which a plurality of units such as polyalkylene oxide or polydimethylsiloxane are bonded via an azo group. As the above-mentioned polymeric azo compound having a structure in which a plurality of units such as polyalkylene oxide are bonded via an azo group, one having a polyethylene oxide structure is preferred. Specific examples of the polymeric azo compound include: a condensation polymer of 4,4'-azobis(4-cyanovaleric acid) and polyalkylene glycol, or a 4,4'-azo compound. Condensation polymers of nitrogen bis(4-cyanovaleric acid) and polydimethylsiloxane with terminal amine groups, etc. Examples of commercially available polymeric azo initiators include VPE-0201, VPE-0401, VPE-0601, VPS-0501, and VPS-1001 (all manufactured by FUJIFILM Wako Pure Chemical Co., Ltd.). Examples of non-polymer azo initiators include V-65 and V-501 (both manufactured by FUJIFILM Wako Pure Chemical Co., Ltd.).

Examples of the organic peroxide include ketone peroxide, peroxyketal, hydrogen peroxide, dialkyl peroxide, peroxyester, diyl peroxide, peroxydicarbonate, and the like.

The above-mentioned thermal radical polymerization initiator may be used alone or in combination of two or more kinds.

Examples of the photoradical polymerization initiator include benzophenone compounds, acetophenone compounds, phosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin ether compounds, and 9-oxosulfide compounds. Compounds etc. Specific examples of the photoradical polymerization initiator include: 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1-(4- Phinylphenyl)-1-butanone, 2-(dimethylamino)-2-((4-methylphenyl)methyl)-1-(4-(4- Phinyl)phenyl)-1-butanone, 2,2-dimethoxy-1,2-diphenylethane-1-one, bis(2,4,6-trimethylbenzoyl) )Phenylphosphine oxide, 2-methyl-1-(4-methylthienyl)-2- Phinylpropan-1-one, 1-(4-(2-hydroxyethoxy)-phenyl)-2-hydroxy-2-methyl-1-propan-1-one, 1-(4-(phenyl) Thio)phenyl)-1,2-octanedione 2-(O-benzoyl oxime), 2,4,6-trimethylbenzoyldiphenylphosphine oxide, etc. The above-mentioned photo radical polymerization initiator may be used alone or in combination of two or more types.

As the above-mentioned cationic polymerization initiator, a photocationic polymerization initiator can be suitably used. The above-mentioned photocationic polymerization initiator is not particularly limited as long as it generates a protonic acid or a Lewis acid by light irradiation, and may be an ionic photoacid generating type or a nonionic photoacid generating type. Examples of the photocationic polymerization initiator include onium salts such as aromatic diazonium salts, aromatic halide salts, and aromatic sulfonium salts, iron-arene complexes, titanocene complexes, and aromatic hydrocarbon complexes. Organometallic complexes such as silanol-aluminum complexes, etc.

Examples of commercially available photocationic polymerization initiators include Adeka Optomer SP-150 and Adeka Optomer SP-170 (both manufactured by ADEKA Corporation).

The above-mentioned photocationic polymerization initiator may be used alone or in combination of two or more types.

The content of the above-mentioned polymerization initiator has a preferable lower limit of 0.01 parts by weight and a preferable upper limit of 10 parts by weight relative to 100 parts by weight of the above-mentioned curable resin. By setting the content of the polymerization initiator within this range, the sealing compound for a liquid crystal display element obtained suppresses liquid crystal contamination and is more excellent in storage stability or curability. A more preferable lower limit of the content of the above-mentioned polymerization initiator is 0.1 parts by weight, and a more preferable upper limit is 5 parts by weight.

The sealant for liquid crystal display elements of the present invention can be suitably used for sealing liquid crystal between substrates of PSA type liquid crystal display elements. The sealant for liquid crystal display elements of the present invention contains soft particles (hereinafter also referred to as "soft particles") whose maximum particle diameter is 100% or more of the cell gap of the liquid crystal display element. The above-mentioned soft particles have the function of becoming a barrier between other sealant components and the liquid crystal when manufacturing a liquid crystal display element, thereby preventing the liquid crystal from being inserted into the sealant and the sealant from dissolving into the liquid crystal. In addition, by blending the above-mentioned soft particles, it is possible to prevent the substrate from shifting after the substrate is bonded before the sealant is hardened. The cell gap of a liquid crystal display element is not limited because it varies depending on the display element. However, generally the cell gap of a liquid crystal display element is 2 μm or more and 10 μm or less.

The maximum particle size of the above-mentioned soft particles is more than 100% of the cell gap of the liquid crystal display element. By setting the maximum particle size of the soft particles to 100% or more of the cell gap of the liquid crystal display element, insertion of liquid crystal into the sealant or contamination of the liquid crystal caused by the sealant can be suppressed. The maximum particle diameter of the above-mentioned soft particles is preferably more than 100% of the cell gap of the liquid crystal display element. In addition, the maximum particle diameter of the above-mentioned soft particles is preferably 5 μm or more. In addition, a preferred upper limit of the maximum particle size of the soft particles is 20 μm. By setting the maximum particle diameter of the soft particles to 20 μm or less, springback can be suppressed, and the obtained liquid crystal display element has better gap retention properties. A more preferable upper limit of the maximum particle diameter of the above-mentioned soft particles is 15 μm. Furthermore, the maximum particle size of the soft particles is preferably 260% or less of the cell gap. By setting the maximum particle size of the soft particles to 260% or less of the cell gap, springback is suppressed, and the obtained liquid crystal display element has better gap retention properties. A more preferable upper limit of the maximum particle size of the soft particles is 220% of the unit gap, and a further preferable upper limit is 170% of the unit gap. In addition, in this specification, the maximum particle diameter of the above-mentioned soft particles and the following average particle diameter refer to values obtained by measuring the particles before being blended into the sealant using a laser diffraction particle size distribution measuring device. . As the above-mentioned laser diffraction particle size distribution measuring device, Mastersizer 2000 (manufactured by Malvern Corporation) or the like can be used. In addition, the maximum particle diameter of the soft particles and the average particle diameter below refer to the maximum value of the particle diameters of 10 particles observed using a scanning electron microscope at a magnification of 10,000 times for the particles contained in the sealant. average value. As the above-mentioned scanning electron microscope, a field emission scanning electron microscope S-4800 (manufactured by Hitachi High-Technologies Co., Ltd.) or the like can be used. Furthermore, in a liquid crystal display element, as long as the presence of soft particles in the cured product of the sealant that is crushed by the bonded substrate and causes distortion in shape is confirmed, it can be said that the maximum particle diameter of the soft particles is the liquid crystal display element. More than 100% of the unit gap.

The above-mentioned soft particles preferably have a content ratio of particles having a particle diameter of 5 μm or more in the particle size distribution of the soft particles measured by the above-mentioned laser diffraction distribution measuring device, which is 60% or more in terms of volume frequency. By setting the content ratio of particles with a particle diameter of 5 μm or more to 60% or more in terms of volume frequency, the effect of suppressing the insertion of liquid crystal into the sealant or the contamination of the liquid crystal caused by the sealant becomes more excellent. The content ratio of particles having a particle diameter of 5 μm or more is more preferably 80% or more.

The above-mentioned soft particles are preferably such that, in the particle size distribution of the soft particles measured by the above-mentioned laser diffraction distribution measuring device, the content ratio of particles occupying 100% or more of the cell gaps of the liquid crystal display element is 70% in terms of volume frequency. above. By setting the particle content ratio in 100% or more of the cell gap of the liquid crystal display element to 70% or more in terms of volume frequency, the effect of suppressing the insertion of liquid crystal into the sealant or the contamination of the liquid crystal caused by the sealant becomes more excellent. The above-mentioned soft particles are more preferably composed of particles containing more than 100% of the cell gap of the liquid crystal display element in terms of volume frequency, that is, they are composed of only particles that account for more than 100% of the cell gap of the liquid crystal display element.

The preferred lower limit of the average particle diameter of the above-mentioned soft particles is 2 μm, and the preferred upper limit is 15 μm. By making the average particle diameter of the above-mentioned soft particles 2 μm or more, the effect of suppressing the insertion of liquid crystal into the sealing compound or the contamination of the liquid crystal by the sealing compound becomes more excellent. By setting the average particle diameter of the above-mentioned soft particles to 15 μm or less, the liquid crystal display element obtained has better gap maintaining properties. A more preferable lower limit of the average particle diameter of the above-mentioned soft particles is 4 μm, and a more preferable upper limit is 12 μm.

As the above-mentioned soft particles, as long as the overall maximum particle diameter is within the above range, two or more types of soft particles with different maximum particle diameters may be mixed and used. That is, soft particles whose maximum particle diameter is less than 100% of the cell gap of the liquid crystal display element and soft particles whose maximum particle diameter is 100% or more of the cell gap of the liquid crystal display element can be mixed and used.

The coefficient of variation (hereinafter also referred to as "CV value") of the particle diameter of the soft particles is preferably 30% or less. By setting the CV value of the particle diameter of the soft particles to 30% or less, the liquid crystal display element obtained has better gap retention properties. The CV value of the particle diameter of the soft particles is more preferably 28% or less, further preferably 15% or less. In addition, in this specification, the said "CV value of particle diameter" means the value calculated|required from the following formula. CV value of particle size (%) = (standard deviation of particle size/average particle size) × 100

Even if the maximum particle diameter, the average particle diameter, or the CV value of the soft particles are outside the above ranges, they can be classified so that the maximum particle diameter, the average particle diameter, or the CV value are within the above ranges. In addition, soft particles whose particle size does not reach 100% of the cell gap of the liquid crystal display element do not contribute to the insertion of liquid crystal into the sealant or the suppression of liquid crystal contamination caused by the sealant. If mixed into the sealant This will cause the thixotropic value to rise, so it is better to remove it by classification in advance. Examples of methods for classifying the soft particles include wet classification and dry classification. Among them, wet classification is preferred, and wet screening classification is more preferred.

It is preferable that the above-mentioned soft particles set the compression displacement from the origin load value to the specific reversal load value when a load is applied to L1, and set the unloading displacement from the reversal load value to the origin load value when the load is released. When it is L2, the response rate of L2/L1 is expressed as a percentage below 80%. By setting the recovery rate of the soft particles to 80% or less, the effect of suppressing the insertion of liquid crystal into the sealant or the contamination of the liquid crystal caused by the sealant becomes more excellent. A more preferable upper limit of the response rate of the soft particles is 70%, and a further preferable upper limit is 60%. Furthermore, the recovery rate of the soft particles is substantially 5% or more. Furthermore, the recovery rate of the above-mentioned soft particles can be derived by analyzing the response behavior after applying a certain load (1 g) to one particle using a micro compression testing machine and then removing the load.

The above-mentioned soft particles preferably have a strain per g of L3/Dn expressed as a percentage of 30% or more when the compression displacement when a load of 1 g is applied is L3 and the particle diameter is Dn. By setting the 1 g strain of the above-mentioned soft particles to 30% or more, the effect of suppressing the insertion of liquid crystal into the sealant or the contamination of the liquid crystal caused by the sealant becomes more excellent. The better lower limit of the 1 g strain of the above-mentioned soft particles is 40%. Furthermore, the 1 g strain of the above-mentioned soft particles can be derived by applying a load of 1 g to one particle using a micro compression testing machine and measuring the displacement amount at that time.

The above-mentioned soft particles preferably have a failure strain expressed as a percentage of L4/Dn of 50% or more when the compression displacement at the point in time when the particles are destroyed is L4 and the particle diameter is Dn. By setting the failure strain of the soft particles to 50% or more, the effect of suppressing the insertion of liquid crystal into the sealant or the contamination of the liquid crystal caused by the sealant becomes more excellent. The better lower limit of the failure strain of the above-mentioned soft particles is 60%. Furthermore, the failure strain of the soft particles can be derived by measuring the displacement amount at which one particle is destroyed by applying a load to the particle using a micro-compression testing machine. The compression displacement L4 is calculated by assuming that the time point when the displacement amount discontinuously increases with respect to the load is the time point when the particles are destroyed. When the load is increased but only deformation occurs without damage, the failure strain is considered to be 100% or more.

The preferred lower limit of the glass transition temperature of the above-mentioned soft particles is -200°C, and the preferred upper limit is 40°C. The lower the glass transition temperature of the above-mentioned soft particles is, the better the tendency is to suppress the insertion of liquid crystal into the sealant or the contamination of the liquid crystal caused by the sealant. By being -200°C or above, the operability of the particles is improved. Become better. By setting the glass transition temperature of the soft particles to 40° C. or less, the liquid crystal display element obtained has better gap retention properties. A more preferred lower limit of the glass transition temperature of the soft particles is -150°C, and a more preferred upper limit is 35°C. The glass transition temperature of the above-mentioned soft particles represents a value measured by differential scanning calorimetry (DSC) based on "Measurement method of transition temperature of plastics" of JIS K 7121.

Examples of the soft particles include polysiloxane-based particles, vinyl-based particles, urethane-based particles, fluorine-based particles, and nitrile-based particles. Among them, polysiloxane-based particles and vinyl-based particles are preferred.

As the polysilicone-based particles, from the viewpoint of dispersibility in resin, polysilicone rubber particles are preferred. Examples of commercially available polysiloxane-based particles include: KMP-594, KMP-597, KMP-598, KMP-600, KMP-601, and KMP-602 (all manufactured by Shin-Etsu Chemical Industry Co., Ltd.), Torayfil E-506S, EP-9215 (both manufactured by Toray Dow Corning Co., Ltd.), etc. can be graded and used. The above-mentioned polysiloxane-based particles may be used alone, or two or more types may be used in combination.

As the vinyl particles, (meth)acrylic particles can be suitably used. The above-mentioned (meth)acrylic particles can be obtained by polymerizing monomers used as raw materials by a known method. Specific examples include: a method of subjecting monomers to suspension polymerization in the presence of a radical polymerization initiator; and a method of absorbing monomers into non-crosslinked seed particles in the presence of a radical polymerization initiator. Methods to swell seed particles to carry out seed polymerization, etc. In addition, in this specification, the said "(meth)acrylic acid" means acrylic acid or methacrylic acid.

As a monomer used as a raw material for forming the (meth)acrylic particles, a monofunctional monomer can be used. Examples of the monofunctional monomer include: alkyl mono(meth)acrylate, oxygen atom-containing mono(meth)acrylate, nitrile group-containing mono(meth)acrylic acid monomer, fluorine atom-containing mono(meth)acrylic acid monomer, and fluorine atom-containing mono(meth)acrylic acid monomer. base) acrylate. Examples of the alkyl mono(meth)acrylate include: (methyl)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, (meth)acrylate Hexyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate Ester, cyclohexyl (meth)acrylate, isocamphenyl (meth)acrylate, etc. Examples of the oxygen atom-containing mono(meth)acrylate include: (meth)acrylic acid 2-hydroxyethyl ester, glycerol (meth)acrylate, polyoxyethylene (meth)acrylate, (meth)acrylate Glycidyl acrylate, etc. Examples of the nitrile group-containing mono(meth)acrylic monomer include (meth)acrylonitrile. Examples of the fluorine atom-containing mono(meth)acrylate include trifluoromethyl (meth)acrylate, pentafluoroethyl (meth)acrylate, and the like. Among them, alkyl mono(meth)acrylate is preferred in that the homopolymer has a low glass transition temperature and can increase the amount of deformation when a load of 1 g is applied. In addition, in this specification, the said "(meth)acrylate" means acrylate or methacrylate.

In addition, in order to have a cross-linked structure, a polyfunctional monomer may be used as the above-mentioned monomer. Examples of the polyfunctional monomer include tetramethylolmethane tetra(meth)acrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane di(meth)acrylate, Trimethylolpropane tri(meth)acrylate, dineopenterythritol hexa(meth)acrylate, dineopenterythritol penta(meth)acrylate, glycerol tri(meth)acrylate, glyceryl diacrylate (Meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, (poly)butylene glycol di(meth)acrylate, 1, 4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, isocyanuric acid skeleton tri(meth)acrylate, etc. Among them, (poly)ethylene glycol di(meth)acrylate and (poly)propylene glycol di(meth)acrylate are preferred because they have a large molecular weight between cross-linking points and can increase the amount of deformation when a load of 1 g is applied. (Meth)acrylate, (poly)butylene glycol di(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylic acid ester.

The preferred lower limit of the usage amount of the above-mentioned polyfunctional monomer in the entire above-mentioned monomer is 1% by weight, and the preferred upper limit is 90% by weight. By setting the usage amount of the above-mentioned polyfunctional monomer to 1% by weight or more, the solvent resistance of the above-mentioned soft particles is improved, and problems such as swelling are not caused when mixed with other sealant components, and the soft particles become easily and uniformly dispersed. By setting the usage amount of the above-mentioned polyfunctional monomer to 90% by weight or less, the recovery rate of the above-mentioned soft particles can be reduced, making it less likely that problems such as springback will occur. A better lower limit of the usage amount of the above-mentioned multifunctional monomer is 3% by weight, and a better upper limit is 80% by weight.

Furthermore, as the above-mentioned monomer, in addition to the acrylic monomers, for example, styrene-based monomers, vinyl ethers, vinyl esters, unsaturated hydrocarbons, halogen atom-containing monomers, or (iso)terpolymers may also be used. Triallyl cyanate, triallyl 1,2,4-benzenetricarboxylate, divinylbenzene, diallyl phthalate, diallylacrylamide, diallyl ether, 3 -(Meth)acryloxypropyltrimethoxysilane, vinyltrimethoxysilane and other monomers. Examples of the styrene-based monomer include styrene, α-methylstyrene, trimethoxysilylstyrene, and the like. Examples of the vinyl ethers include methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, and the like. Examples of the vinyl esters include vinyl acetate, vinyl butyrate, vinyl laurate, vinyl stearate, and the like. Examples of the unsaturated hydrocarbon include ethylene, propylene, isoprene, butadiene, and the like. Examples of the halogen atom-containing monomer include vinyl chloride, vinyl fluoride, chlorostyrene, and the like.

In addition, as the above-mentioned vinyl particles, for example, polydivinylbenzene particles, polychloroprene particles, butadiene rubber particles, etc. can also be used.

Examples of commercially available urethane-based particles include Artpearl (manufactured by Negami Industrial Co., Ltd.), Daimic Beaz (manufactured by Dainichi Seika Industrial Co., Ltd.), etc. These particles can be classified and used.

The preferred lower limit of the hardness of the above-mentioned soft particles is 3, and the preferred upper limit is 50. By setting the hardness of the soft particles within this range, the liquid crystal display element obtained has better gap retention properties. A more preferable lower limit of the hardness of the soft particles is 10, a more preferable upper limit is 40, and a further preferable lower limit is 20. Furthermore, in this specification, the above-mentioned "hardness of soft particles" refers to the durometer A hardness measured by the method according to JIS K 6253.

The preferred lower limit of the content of the soft particles in the sealant for liquid crystal display elements of the present invention is 5% by weight, and the preferred upper limit is 60% by weight. By making the content of the above-mentioned soft particles 5% by weight or more, the effect of suppressing the insertion of liquid crystal into the sealant or the contamination of the liquid crystal caused by the sealant becomes more excellent. By setting the content of the above-mentioned soft particles to 60% by weight or less, the sealing compound for liquid crystal display elements obtained becomes one with more excellent adhesiveness. A more preferred lower limit of the content of the soft particles is 10% by weight, a more preferred upper limit is 50% by weight, a further preferred lower limit is 20% by weight, and a further preferred upper limit is 40% by weight.

In order to increase the viscosity, improve adhesion through stress dispersion effect, improve linear expansion rate, etc., the sealant for liquid crystal display elements of the present invention preferably contains a filler.

As the above-mentioned filler, an inorganic filler or an organic filler can be used. Examples of the inorganic filler include silica, talc, glass beads, asbestos, gypsum, diatomaceous earth, bentonite, bentonite, montmorillonite, sericite, activated clay, aluminum oxide, zinc oxide, and iron oxide. , magnesium oxide, tin oxide, titanium oxide, calcium carbonate, magnesium carbonate, magnesium hydroxide, aluminum hydroxide, aluminum nitride, silicon nitride, barium sulfate, calcium silicate, etc. Examples of the organic filler include polyester microparticles, polyurethane microparticles, vinyl polymer microparticles, and acrylic polymer microparticles. The above-mentioned fillers may be used alone or in combination of two or more types.

The preferred lower limit of the content of the above-mentioned filler in 100 parts by weight of the sealant for liquid crystal display elements of the present invention is 10 parts by weight, and the preferred upper limit is 70 parts by weight. By setting the content of the filler in this range, the effect of improving adhesion and the like is more excellent without deteriorating the coating properties. A more preferable lower limit of the content of the above filler is 20 parts by weight, and a more preferable upper limit is 60 parts by weight.

The sealing compound for liquid crystal display elements of the present invention may also contain a silane coupling agent. The above-mentioned silane coupling agent mainly functions as an adhesion aid for satisfactorily adhering the sealant to the substrate and the like.

As the silane coupling agent, for example, 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-isocyanate can be suitably used. Acidyl propyltrimethoxysilane, etc. These silane coupling agents are excellent in improving adhesion with substrates and the like, and can prevent the curable resin from flowing out into the liquid crystal by chemically bonding with the curable resin. The above-mentioned silane coupling agent can be used alone or in combination of two or more kinds.

The preferred lower limit of the content of the above-mentioned silane coupling agent in 100 parts by weight of the sealant for liquid crystal display elements of the present invention is 0.1 parts by weight, and the preferred upper limit is 10 parts by weight. By setting the content of the silane coupling agent within this range, liquid crystal contamination is suppressed and the effect of improving adhesion becomes more excellent. A more preferable lower limit of the content of the above-mentioned silane coupling agent is 0.3 parts by weight, and a more preferable upper limit is 5 parts by weight.

The sealing compound for liquid crystal display elements of the present invention may also contain a light-shielding agent. By containing the above-mentioned light-shielding agent, the sealing compound for liquid crystal display elements of the present invention can be suitably used as a light-shielding sealing agent.

Examples of the light-shielding agent include iron oxide, titanium black, aniline black, cyanine black, fullerene, carbon black, resin-coated carbon black, and the like. Among them, titanium black is preferred.

The above-mentioned titanium black is a substance that has a higher transmittance for light near the ultraviolet region, especially for light with a wavelength of 370 nm to 450 nm, compared with the average transmittance for light with a wavelength of 300 nm to 800 nm. That is, the above-mentioned titanium black-based light-shielding agent has the property of imparting light-shielding properties to the sealing compound for liquid crystal display elements of the present invention by fully blocking light of wavelengths in the visible light range, and on the other hand, making wavelengths near the ultraviolet range The light shines through. Therefore, as the above-mentioned photoradical polymerization initiator or the above-mentioned photocationic polymerization initiator, the person who initiates the reaction is used as the above-mentioned photoradical polymerization initiator or the above-mentioned photocationic polymerization initiator by using light with a wavelength (370 nm or more and 450 nm or less) that can be increased by the transmittance of the titanium black. , can further increase the photocurability of the sealant for liquid crystal display elements of the present invention. On the other hand, the light-shielding agent contained in the sealing compound for liquid crystal display elements of the present invention is preferably a substance with high insulation properties. As the light-shielding agent with high insulation properties, titanium black is also suitable. The above-mentioned titanium black preferably has an optical density (OD value) per 1 μm of 3 or more, more preferably 4 or more. The higher the light-shielding property of the titanium black, the better. The OD value of the titanium black does not have a particularly preferable upper limit, but is usually 5 or less.

The above-mentioned titanium black can exert sufficient effects even if it is not surface-treated, but it can also be used with the surface treated with organic components such as coupling agents, or made of silicon oxide, titanium oxide, germanium oxide, aluminum oxide, zirconium oxide, magnesium oxide, etc. Surface-treated titanium black coated with inorganic components. Among them, those treated with organic components are preferred because they can further improve insulation properties. In addition, the liquid crystal display element manufactured using the sealing compound for liquid crystal display elements of the present invention mixed with the above-mentioned titanium black as a light-shielding agent has sufficient light-shielding properties, so there is no light leakage and a high contrast ratio, so that it can be realized Liquid crystal display components with excellent image display quality.

Examples of commercially available titanium blacks include titanium black manufactured by Mitsubishi Materials Co., Ltd., titanium black manufactured by Akaho Chemicals Co., Ltd., and the like. Examples of the titanium black manufactured by Mitsubishi Materials include 12S, 13M, 13M-C, 13R-N, 14M-C, and the like. Examples of the titanium black manufactured by Akaho Chemicals Co., Ltd. include Tilack D and the like.

The preferred lower limit of the specific surface area of the titanium black is 13 m ² /g, the preferred upper limit is 30 m ² /g, the preferred lower limit is 15 m ² /g, and the preferred upper limit is 25 m ² /g. In addition, the preferred lower limit of the volume resistance of the titanium black is 0.5 Ω·cm, the preferred upper limit is 3 Ω·cm, the more preferred lower limit is 1 Ω·cm, and the more preferred upper limit is 2.5 Ω·cm.

The primary particle size of the above-mentioned light-shielding agent is not particularly limited as long as it is less than or equal to the distance between the substrates of the liquid crystal display element. The preferred lower limit is 1 nm and the preferred upper limit is 5000 nm. By setting the primary particle diameter of the light-shielding agent within this range, it is possible to obtain one with better light-shielding properties without deteriorating the applicability and the like of the sealing compound for liquid crystal display elements obtained. A more preferable lower limit of the primary particle size of the above-mentioned sunscreen agent is 5 nm, a more preferable upper limit is 200 nm, a further preferable lower limit is 10 nm, and a further preferable upper limit is 100 nm. In addition, the primary particle size of the above-mentioned light-shielding agent can be measured by dispersing the above-mentioned light-shielding agent in a solvent (water, organic solvent, etc.) using NICOMP 380ZLS (manufactured by PARTICLE SIZING SYSTEMS).

The preferred lower limit of the content of the above-mentioned light-shielding agent in 100 parts by weight of the sealant for liquid crystal display elements of the present invention is 5 parts by weight, and the preferred upper limit is 80 parts by weight. By setting the content of the light-shielding agent within this range, the obtained sealing compound for liquid crystal display elements can exhibit more excellent light-shielding properties without significantly reducing the adhesiveness, strength after curing, and drawing properties. A more preferable lower limit of the content of the above-mentioned sunscreen agent is 10 parts by weight, a more preferable upper limit is 70 parts by weight, a further preferable lower limit is 30 parts by weight, and a further preferable upper limit is 60 parts by weight.

The sealant for a liquid crystal display element of the present invention may further contain other additives such as a stress reliever, a reactive diluent, a thixotropic agent, a spacer, a hardening accelerator, a defoaming agent, a leveling agent, and a polymerization inhibitor as necessary.

The method of producing the sealing compound for liquid crystal display elements of the present invention is not particularly limited. For example, a mixer is used to mix a curable resin, a thermosetting agent, soft particles, and additives such as a silane coupling agent if necessary. Examples of the mixer include a homogeneous disperser, a homogeneous mixer, a universal mixer, a planetary mixer, a kneader, a three-roller kneader, and the like.

By blending conductive fine particles into the sealing compound for liquid crystal display elements of the present invention, a vertical conductive material can be produced. Furthermore, an upper and lower conductive material containing the sealant for liquid crystal display elements of the present invention and conductive fine particles is also one of the present invention.

As the conductive fine particles, metal balls, resin fine particles having a conductive metal layer formed on their surfaces, etc. can be used. Among them, those having a conductive metal layer formed on the surface of the resin particles are more suitable in that conductive connection can be achieved without damaging the transparent substrate etc. due to the excellent elasticity of the resin particles.

In addition, a liquid crystal display element using the sealant for liquid crystal display elements of the present invention or the upper and lower conductive materials of the present invention is also one of the present invention. The liquid crystal display element of the present invention is preferably a liquid crystal display element with a narrow edge design. Specifically, the width of the frame portion around the liquid crystal display portion is preferably 2 mm or less. Moreover, when manufacturing the liquid crystal display element of the present invention, the coating width of the sealant for liquid crystal display elements of the present invention is preferably 1 mm or less.

As a method for manufacturing the liquid crystal display element of the present invention, a liquid crystal dropping method can be suitably used. Specific examples thereof include a method having the following steps. First, the following steps are performed: apply the sealant for liquid crystal display elements of the present invention on one of two transparent substrates having an electrode such as an ITO film and an alignment film by screen printing, dispenser coating, etc. to form a frame-shaped Seal pattern. Next, the following steps are performed: in a state where the sealant for liquid crystal display elements of the present invention is not hardened, droplets of a liquid crystal composition containing a polymeric compound are added dropwise and applied to the frame of the sealing pattern on the substrate, and then overlapped under vacuum Another transparent substrate. Thereafter, the step of curing the sealing compound for liquid crystal display elements of the present invention by heating is performed. Furthermore, the following steps are performed: polymerizing the polymerizable compound in the liquid crystal composition by light irradiation while applying a voltage to form a concave and convex shape on the substrate; by the method including the above steps, a PSA type liquid crystal display can be obtained element. In addition, before the step of hardening the sealing compound for liquid crystal display elements of the present invention by heating, a step of temporarily hardening the sealing compound by light irradiation may be performed. However, the sealing compound for liquid crystal display elements of the present invention inhibits the formation of liquid crystals. The effect of insertion into the sealant or liquid crystal contamination caused by the sealant becomes particularly significant when the sealant is hardened by heat alone. [Effects of the invention]

According to the present invention, it is possible to provide a sealant for a liquid crystal display element that can suppress the insertion of liquid crystal into the sealant or the contamination of the liquid crystal caused by the sealant, and can obtain a liquid crystal display element with excellent adhesion and excellent display performance. Furthermore, according to the present invention, it is possible to provide an upper and lower conductive material and a liquid crystal display element using the sealant for liquid crystal display elements.

Examples will be disclosed below to explain the present invention in further detail. However, the present invention is not limited only to these Examples.

(Synthesis of some acrylic modified diphenyl ether epoxy resins) On one side, mix 1000 parts by weight of diphenyl ether type epoxy resin (manufactured by NIPPON STEEL Chemical & Material Co., "YSLV80DE"), 2 parts by weight of p-methoxyphenol as a polymerization inhibitor, and 2 parts by weight of triethylamine as a reaction catalyst. and 229 parts by weight of acrylic acid were refluxed and stirred at 90° C. while feeding air, and allowed to react for 5 hours. In order to adsorb ionic impurities in the reactant, 100 parts by weight of the resin obtained was filtered using a column filled with 10 parts by weight of a natural combination of quartz and kaolin (manufactured by Hoffmann Mineral Company, "Sillitin V85") to obtain part of the acrylic acid. Modified diphenyl ether type epoxy resin.

(Synthesis of resorcinol-type epoxy acrylate) On one side, mix 1000 parts by weight of resorcinol-type epoxy resin (manufactured by Nagase Chemical Co., Ltd., "DENACOL EX-201"), 2 parts by weight of p-methoxyphenol as a polymerization inhibitor, and triethylamine as a reaction catalyst. 2 parts by weight and 649 parts by weight of acrylic acid were refluxed and stirred at 90° C. for 5 hours while feeding air to react. In order to adsorb ionic impurities in the reactant, 100 parts by weight of the resin obtained was filtered using a column filled with 10 parts by weight of a natural combination of quartz and kaolin (manufactured by Hoffmann Mineral Company, "Sillitin V85") to obtain isophthalic acid. Diphenol type epoxy acrylate.

(Grading of polysilicone rubber particles) Polysilicone rubber particles (manufactured by Shin-Etsu Chemical Industry Co., Ltd., "KMP-601") were dispersed in methanol, and the particle size was in the range of 5 to 8 μm using an 8 μm mesh sieve and a 5 μm mesh sieve. Perform wet screening classification. The classified particles are recovered and dried to obtain classified products of polysilicone rubber particles. The screen uses extremely high-precision holes obtained by ultra-high-precision micromachining of polyimide films using lasers. The maximum particle size measured using a laser diffraction particle size distribution analyzer ("Mastersizer-2000" manufactured by Malvern Corporation) of the obtained classified polysilicone rubber particles was 8 μm. In addition, the classification of polysilicone rubber particles was obtained in the same manner, except that a wet sieve classification was performed using a 6 μm mesh sieve and a 3 μm mesh sieve so that the particle size fell into the range of 3 to 6 μm. Processed product (maximum particle size 6 μm). Furthermore, a classified product of polysilicone rubber particles (maximum particle diameter 3 μm) was obtained in the same manner, except that a wet sieve classification was performed using a 3 μm mesh sieve so that the particle diameter fell into a range of 3 μm or less. ).

(Examples 1 to 10, Comparative Examples 1 to 3) According to the blending ratio described in Table 1, each material was mixed using a planetary mixer (manufactured by Thinky Corporation, "Go Soaken Taro"), and then mixed using a three-roller kneader to prepare Examples 1 to 10. , Sealing compound for liquid crystal display elements of Comparative Examples 1 to 3.

＜Evaluation＞ The following evaluations were performed on each sealing compound for liquid crystal display elements obtained in Examples and Comparative Examples. The results are shown in Table 1.

(Adhesion) 1 part by weight of spacer particles with an average particle diameter of 5 μm (Sekisui Chemical Industry Co., Ltd.) was mixed with 100 parts by weight of the sealant for each liquid crystal display element obtained in the Examples and Comparative Examples using a planetary stirring device. Manufactured by "Micropearl SP-2050") and dispersed evenly. Take a very small amount of the sealant dispersed with spacer particles to the center of a glass substrate (20 mm × 50 mm × thickness 0.7 mm), and overlap the same type of glass substrate on top. The liquid crystal display element was spread with the sealant, and heated at 120° C. for 1 hour to harden the sealant to obtain a bonded test piece. Using a tensiometer, the bonding strength of the obtained bonded test piece was measured. The case where the bonding strength is 200 N/cm ² or more is designated as "O", the case where the bonding strength is 150 N/cm ² or more and less than 200 N/cm ² is designated as "Δ", and the case where the bonding strength is less than 150 is represented as "Δ" The case of N/cm ² was set as "×" to evaluate the adhesion.

(Insertion Prevention) 1 part by weight of spacer particles with an average particle diameter of 5 μm (Sekisui Chemical Industry Co., Ltd. manufactured by the company, "Micropearl SP-2050") is dispersed evenly. The sealant in which the spacer particles are dispersed is filled into a dispensing syringe (manufactured by Musashi High-tech Co., Ltd., "PSY-10E") and degassed. Using a dispenser ("SHOTMASTER 300" manufactured by Musashi High-Tech Co., Ltd.), the degassed sealant is applied to the glass substrate with the ITO film and the alignment film in a manner that draws a rectangular frame. Next, a liquid crystal composition containing a polymerizable compound (MLC-6883 (manufactured by Merck)) was dropped using a liquid crystal dropping device and 1 wt% of bis(2-methacrylic acid)biphenyl 4,4'-diyl ester was added. And the one who gets it) is a tiny drop. Another glass substrate having an ITO film and an alignment film is overlapped on the glass substrate on which the liquid crystal composition is dropped and coated via the liquid crystal display element sealant of the present invention, and then a vacuum laminating device is used under a vacuum of 5 Pa. The unit is obtained by laminating. The obtained unit was heated at 120°C for 1 hour to harden the sealant. Next, a mercury lamp is used to irradiate ultraviolet light (wavelength 313 nm) of 100 mW/cm ² for 50 seconds while a voltage is applied to polymerize the polymerizable compound in the liquid crystal composition to form a concave and convex shape, thereby obtaining a liquid crystal display element (cell gap) 5 μm). For each obtained liquid crystal display element, the shape of the sealing pattern was observed. The shape of the sealing pattern is not disturbed by the internal liquid crystal as "◎". The shape of the sealing pattern is slightly disturbed as "○". The shape of the sealing pattern is greatly disturbed but the liquid crystal does not penetrate the sealing pattern. is "Δ", and the liquid crystal penetrates the sealing pattern and is exposed to the outside as "×", and the insertion prevention property is evaluated.

(Display performance of liquid crystal display elements) In the same manner as the evaluation of "(insertion prevention)" above, each obtained liquid crystal display element was visually confirmed to be in a state where a voltage was applied for 100 hours in an environment of 60°C and 90% RH near the sealant. The liquid crystal alignment is disordered (uneven display). The case where no display unevenness is observed on the liquid crystal display element is set as "0", the case where display unevenness is visible near the sealant (peripheral part) of the liquid crystal display element is set as "Δ", and the case where the display unevenness is not only located near the sealant of the liquid crystal display element (peripheral part) is set as "Δ" The case where the peripheral part also extended to the central part was regarded as "×", and the display performance of the liquid crystal display element was evaluated. In addition, liquid crystal display elements rated "0" are of a grade that has no practical problems at all, liquid crystal display elements of "Δ" are a grade that may cause problems depending on the display design, and liquid crystal display elements of "×" are not resistant to Practical level.

[Table 1] [Industrial availability]

According to the present invention, it is possible to provide a sealant for a liquid crystal display element that can suppress the insertion of liquid crystal into the sealant or the contamination of the liquid crystal caused by the sealant, and can obtain a liquid crystal display element with excellent adhesion and excellent display performance. Furthermore, according to the present invention, it is possible to provide an upper and lower conductive material and a liquid crystal display element using the sealant for liquid crystal display elements.

without

without

Claims (5)

A sealant for liquid crystal display elements, which contains: a curable resin, a thermosetting agent, and soft particles with a maximum particle diameter of more than 100% of the cell gap of a liquid crystal display element, and the curable resin contains more than 3 particles per molecule. Compounds with epoxy groups, the above-mentioned compounds with more than 3 epoxy groups in 1 molecule are compounds with more than 3 epoxy groups with isocyanuric skeleton (isocyanuric skeleton) in 1 molecule, and/or in 1 molecule A glycidylamine-type epoxy compound having three or more epoxy groups, and the soft particles have a content ratio of particles that account for more than 100% of the cell gap of the liquid crystal display element, in terms of volume frequency, of more than 70%. The sealant for liquid crystal display elements according to claim 1, wherein the compound having 3 or more epoxy groups in 1 molecule is the compound having 3 or more epoxy groups in 1 molecule and an isocyanuric acid skeleton. . The sealant for liquid crystal display elements according to claim 1 or 2 is used for sealing liquid crystal between substrates of PSA type liquid crystal display elements. A vertical conductive material containing the sealant for liquid crystal display elements according to claim 1, 2 or 3 and conductive fine particles. A liquid crystal display element made of the sealant for liquid crystal display elements described in Claim 1, 2 or 3 or the upper and lower conductive material described in Claim 4.