Sealing agent for liquid crystal display element

Abstract

The purpose of the present invention is to provide a sealing agent for a liquid crystal display element, which has excellent adhesion to an alignment film and excellent moisture permeation resistance, and which is capable of suppressing peeling after photocuring even when applied to a large substrate. The present invention relates to a sealing agent for a liquid crystal display element, which contains a curable resin and a photopolymerization initiator, the curable resin containing a compound represented by formula (1), and the cured product of the sealing agent for a liquid crystal display element having a thickness of 5.0 [mu] m obtained by irradiation with ultraviolet light having a wavelength of 365 nm of 3000 mJ / cm2, the compressive shear adhesive strength to polyimide as measured under the conditions of 25 DEG C and a shear rate of 1 mm / sec in accordance with JIS K 6852 is 15 kgf / cm2 or more. In formula (1), R1 represents a hydrogen atom or a methyl group, R2 represents a group represented by formula (2-1), (2-2), or (2-3), R3 represents a methylene group, a methylmethylene group, a dimethylmethylene group, or a sulfonyl group, X represents a ring-opening structure of a lactone, and n is 1-5. In formulae (2-1) to (2-3), * represents a bonding position, in formula (2-2), a is an integer of 1-8, in formula (2-3), b is an integer of 1-8, c is an integer of 1-3, and d is an integer of 1-8. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a sealant for a liquid crystal display element that has excellent adhesiveness and moisture-proof permeability to an alignment film and can suppress peeling after photocuring even when coated on a large substrate. Background Art

[0002] In recent years, as a method for manufacturing a liquid crystal display element, from the viewpoints of shortening the production cycle time and optimizing the amount of liquid crystal used, a liquid crystal dropping method called a drop process that uses a photo-thermosetting sealant containing a curable resin, a photoinitiator, and a thermosetting agent, as disclosed in Patent Document 1 and Patent Document 2, has been adopted.

[0003] In recent years, as a method for manufacturing a liquid crystal display element such as a liquid crystal display cell, from the viewpoints of shortening the production cycle time and optimizing the amount of liquid crystal used, a method called a drop process that uses a curable resin composition as a sealant, as disclosed in Patent Document 1 and Patent Document 2, has been adopted.

[0004] In the drop process, first, a sealant is coated on one of two electrode-bearing substrates to form a frame-shaped seal pattern. Next, minute drops of liquid crystal are dropped into the seal frame of the substrate in a state where the sealant is not cured, and another substrate is overlapped under vacuum, and the sealant is cured by light irradiation and heating to produce a liquid crystal display element. Currently, this drop process has become the mainstream of the method for manufacturing liquid crystal display elements. Along with such a narrow bezel design, the coating position of the sealant is more likely to be on an alignment film such as polyimide.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2001-133794

[0008] Patent Document 2: International Publication No. 02 / 092718 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] Generally, a liquid crystal display element is manufactured by forming a plurality of cells on a mother glass and then dividing each cell. In recent years, the mother glass and the display have been continuously enlarged, and the substrate is likely to peel off in the manufacturing process of the liquid crystal display element. Conventionally, from the viewpoints of adhesiveness and moisture-proof permeability, a (meth)acrylic acid-based compound or the like has been used as a curable resin incorporated into the sealant, and it has been photocured. However, especially due to vibrations during conveyance after the photocuring process, the substrate sometimes peels off.

[0011] An object of the present invention is to provide a sealant for a liquid crystal display element that has excellent adhesiveness to an alignment film and moisture-proof permeability, and can suppress peeling after photocuring even when coated on a large substrate.

[0012] Means for Solving the Problem

[0013] The present disclosure 1 relates to a sealant for a liquid crystal display element, which contains a curable resin and a photoinitiator. The curable resin contains a compound represented by the following formula (1). For a cured product with a thickness of 5.0 μm of the sealant for a liquid crystal display element obtained by irradiating ultraviolet rays with a wavelength of 365 nm of 3000 mJ / cm 2 The compression shear adhesion strength to polyimide measured according to JIS K 6852 at 25°C and a shear rate of 1 mm / sec is 15 kgf / cm 2 or more.

[0014] The present disclosure 2 relates to the sealant for a liquid crystal display element of the present disclosure 1, which further contains an organic filler. The content of the organic filler is 5 parts by mass or more with respect to 100 parts by mass of the curable resin.

[0015] The present disclosure 3 relates to the sealant for a liquid crystal display element of the present disclosure 1 or 2. When the ratio of the number of epoxy groups in 1 molecule of the compound contained in the curable resin to the total number of epoxy groups and (meth)acryloyl groups in 1 molecule of the compound is set to P E The epoxy functional group ratio represented by the mass average value of P E in the entire curable resin is 30% or more.

[0016] The present disclosure 4 relates to the sealant for a liquid crystal display element of the present disclosure 1, 2 or 3, which further contains an inorganic filler. The content of the inorganic filler is 5 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the curable resin.

[0017] The present disclosure 5 relates to the sealant for a liquid crystal display element of the present disclosure 1, 2, 3 or 4. For a cured product with a thickness of 300 μm obtained by irradiating it with ultraviolet rays with a wavelength of 365 nm of 3000 mJ / cm 2 and heating at 120°C for 1 hour, the moisture permeability measured according to JIS Z 0208 in an environment of 80°C and 90% RH is 75 g / m 2 ·24 hr or less.

[0018] The present disclosure 6 relates to the sealant for a liquid crystal display element of the present disclosure 1, 2, 3, 4 or 5. By irradiating it with ultraviolet rays with a wavelength of 365 nm of 3000 mJ / cm 2The cured product obtained by irradiating ultraviolet light with a wavelength of 365 nm has a storage modulus of 3.5 GPa or less at 25°C.

[0019] [Chemical formula 1]

[0020]

[0021] In formula (1), R 1 represents a hydrogen atom or a methyl group, and R 2 represents a group represented by the following formula (2-1), (2-2), or (2-3), and R 3 represents a methylene group, a methylmethylene group, a dimethylmethylene group, or a sulfonyl group, X represents a ring-opening structure of a lactone, and n is an integer of 1 or more and 5 or less.

[0022] [Chemical formula 2]

[0023]

[0024] In formulas (2-1) to (2-3), * represents a bonding position. In formula (2-2), a is an integer of 1 or more and 8 or less. In formula (2-3), b is an integer of 1 or more and 8 or less, c is an integer of 1 or more and 3 or less, and d is an integer of 1 or more and 8 or less.

[0025] Hereinafter, the present invention will be described in detail.

[0026] In order to make the adhesiveness to the alignment film and the moisture-proof permeability excellent and to suppress peeling after photocuring, the inventor of the present invention studied adjusting the peel adhesive strength of the sealant after photocuring on the basis of using a partial (meth)acrylic compound having a specific soft skeleton. However, even when the peel adhesive strength was adjusted, the effect of suppressing peeling after photocuring could not be reproduced. Therefore, the inventor of the present invention studied adjusting the low-speed compression shear adhesive strength at a shear rate of 1 mm / sec to a specific value or more for the sealant after photocuring. As a result, it was found that a sealant for a liquid crystal display element having excellent adhesiveness to the alignment film and moisture-proof permeability and capable of suppressing peeling after photocuring even when coated on a large substrate could be obtained, and thus the present invention was completed.

[0027] Regarding the sealant for a liquid crystal display element of the present invention, for the cured product having a thickness of 5.0 μm of the above-mentioned sealant for a liquid crystal display element obtained by irradiating it with ultraviolet light having a wavelength of 365 nm at 3000 mJ / cm 2 The lower limit of the compression shear adhesive strength to a glass substrate (hereinafter, also referred to as "low-speed compression shear adhesive strength after photocuring") measured according to JIS K6852 under the conditions of 25°C and a shear rate of 1 mm / sec is 15 kgf / cm 2By making the low-speed compression shear bond strength after the above-mentioned photocuring be 15 kgf / cm 2 or more, the sealant for liquid crystal display elements of the present invention can suppress peeling after photocuring. The preferred lower limit of the low-speed compression shear bond strength after the above-mentioned photocuring is 20 kgf / cm 2 , and the more preferred lower limit is 25 kgf / cm 2 .

[0028] The preferred upper limit of the low-speed compression shear bond strength after the above-mentioned photocuring is not particularly limited, and the substantial upper limit is 100 kgf / cm 2 .

[0029] It should be noted that the low-speed compression shear bond strength after the above-mentioned photocuring can be measured by the following method.

[0030] That is, first, prepare 2 substrates (polyimide substrates) obtained by coating a polyimide solution on an ITO substrate with a length of 45 mm, a width of 25 mm, and a thickness of 0.7 mm and treating it with a film thickness of about 100 nm. Dot the sealant on one of them so that the diameter at the time of bonding becomes 3 mm. Overlap another polyimide substrate on the polyimide substrate on which the sealant is dotted with the sealant so that they are offset by 10 mm in the length direction. Then, irradiate ultraviolet rays with a wavelength of 365 nm of 3000 mJ / cm 2 using a metal halide lamp or the like to cure the sealant, and obtain a test piece of a cured product of the sealant with a thickness of 5.0 μm. For the obtained test piece, the low-speed compression shear bond strength after photocuring can be measured according to JIS K 6852 under the conditions of 25°C and a shear speed of 1 mm / sec.

[0031] Regarding the sealant for liquid crystal display elements of the present invention, for a cured product with a thickness of 300 μm obtained by irradiating ultraviolet rays with a wavelength of 365 nm of 3000 mJ / cm 2 and heating at 120°C for 1 hour, the preferred upper limit of the moisture permeability measured according to JIS Z 0208 in an environment of 80°C and 90% RH is 75 g / m 2 ·24 hr. By making the above-mentioned moisture permeability be 75 g / m 2 ·24 hr or less, the reliability of the obtained liquid crystal display element becomes more excellent. The more preferred upper limit of the above-mentioned moisture permeability is 65 g / m 2 ·24 hr.

[0032] In addition, the preferred lower limit of the above-mentioned moisture permeability is not particularly limited, and the substantial lower limit is 35 g / m 2 ·24 hr.

[0033] Regarding the sealant for liquid crystal display elements of the present invention, the upper limit of the storage modulus at 25°C (hereinafter, also referred to as the "storage modulus after photocuring") of the cured product obtained by irradiating ultraviolet rays with a wavelength of 365 nm of 3000 mJ / cm 2 is preferably 3.5 GPa. By making the storage modulus after the above photocuring 3.5 GPa or less, the effect of suppressing peeling after photocuring of the sealant for liquid crystal display elements of the present invention becomes more excellent. The more preferable upper limit of the storage modulus after the above photocuring is 3.0 GPa.

[0034] In addition, from the viewpoint of adhesiveness when bonding adherends, the preferable lower limit of the storage modulus after the above photocuring is 0.1 GPa, and the more preferable lower limit is 1.0 GPa.

[0035] It should be noted that the above storage modulus can be measured using a dynamic viscoelasticity measuring device (for example, manufactured by IT Measurement Control Co., Ltd., "DVA-200", etc.) under the conditions of a tensile mode, a test piece width of 5 mm, a thickness of 0.35 mm, a clamping width of 25 mm, a heating rate of 10°C / minute, and a frequency of 5 Hz.

[0036] The above-mentioned low-speed compression shear adhesive strength after photocuring, the above-mentioned moisture permeability, and the above-mentioned storage modulus after photocuring can be set within the above ranges by selecting their types and adjusting the content ratios of the curable resin, photoinitiator, and other components such as organic fillers and inorganic fillers described later.

[0037] The sealant for liquid crystal display elements of the present invention contains a curable resin.

[0038] The above curable resin contains the compound represented by the above formula (1). By containing the compound represented by the above formula (1), the adhesiveness of the sealant for liquid crystal display elements of the present invention to the alignment film and the moisture barrier property are excellent, and it is easy to make the above-mentioned low-speed compression shear adhesive strength after photocuring and the above-mentioned storage modulus after photocuring within the above ranges.

[0039] In the above formula (1), R 2 represents a group represented by the above formula (2-1), (2-2), or (2-3). Among them, from the viewpoints of the adhesiveness of the obtained sealant for liquid crystal display elements and the softness of the cured product, the above R 2 is preferably the group represented by the above formula (2-2), and more preferably the group in which a is 2 in the above formula (2-2) (vinylidene).

[0040] It should be noted that in the above formula (2-1) and formula (2-3), among the bonding positions represented by *, the bonding position on the methylene side becomes the bonding position with (meth)acryloyloxy in the above formula (1).

[0041] It should be noted that in this specification, the above-mentioned "(meth)acryloyl" refers to acryloyl or methacryloyl.

[0042] In the above formula (1), R 3 represents methylene, methylmethylene, dimethylmethylene or sulfonyl. Among them, the above R 3 is preferably methylene, methylmethylene or dimethylmethylene.

[0043] In the above formula (1), X represents the ring-opening structure of a lactone.

[0044] Examples of the above lactone include: γ-undecalactone, ε-caprolactone, γ-decalactone, σ-dodecalactone, γ-nonalactone, γ-heptalactone, γ-valerolactone, σ-valerolactone, β-butyrolactone, γ-butyrolactone, β-propiolactone, σ-caprolactone, 7-butyl-2-oxepanone, etc. Among them, a lactone with 5 or more and 7 or less carbon atoms in the straight-chain part of the main skeleton when the ring is opened is preferred.

[0045] As a method for producing the compound represented by the above formula (1), for example, the following methods can be cited.

[0046] That is, it can be cited: First, a (meth)acrylic acid-based compound having a hydroxyl group and a group corresponding to the above R 2 is reacted with a lactone in the presence of an inhibitor by heating and stirring, etc., and then the above phthalic acid or phthalic anhydride is added and reacted by heating and stirring, etc. Next, an epoxy compound having a bisphenol skeleton such as bisphenol A diglycidyl ether is added to the obtained reaction product and heated and stirred, etc., so that a part of the epoxy groups of the epoxy compound having a bisphenol skeleton reacts.

[0047] It should be noted that in this specification, the above-mentioned "(meth)acrylic acid" refers to acrylic acid or methacrylic acid.

[0048] For the purpose of adjusting the low-speed compression shear adhesion strength after the above-mentioned photocuring, the above-mentioned moisture permeability and the storage modulus after the above-mentioned photocuring, or improving the low liquid crystal contamination, etc., the above-mentioned curable resin preferably contains other curable resins other than the compound represented by the above formula (1).

[0049] When the above-mentioned other curable resin is contained, the preferred lower limit of the content of the compound represented by the above-mentioned formula (1) in 100 parts by mass of the above-mentioned curable resin is 10 parts by mass, and the preferred upper limit is 70 parts by mass. By making the content of the compound represented by the above-mentioned formula (1) within this range, it is easier to make the low-speed compression shear bond strength after the above-mentioned photocuring, the above-mentioned water vapor permeability, and the above-mentioned storage modulus after the above-mentioned photocuring within the above range. The more preferred lower limit of the content of the compound represented by the above-mentioned formula (1) is 15 parts by mass, and the more preferred upper limit is 50 parts by mass.

[0050] Examples of the other curable resins include epoxy compounds and (meth)acrylic compounds.

[0051] Examples of the epoxy compound include bisphenol A epoxy compounds, bisphenol F epoxy compounds, bisphenol S epoxy compounds, 2,2'-diallylbisphenol A epoxy compounds, hydrogenated bisphenol epoxy compounds, propylene oxide-added bisphenol A epoxy compounds, resorcinol epoxy compounds, biphenyl epoxy compounds, thioether epoxy compounds, diphenyl ether epoxy compounds, dicyclopentadiene epoxy compounds. epoxides, naphthalene-type epoxy compounds, phenol novolac-type epoxy compounds, o-cresol novolac-type epoxy compounds, dicyclopentadiene novolac-type epoxy compounds, biphenyl novolac-type epoxy compounds, naphthol novolac-type epoxy compounds (Japanese: ナフタレンフェノールノボラック type epoxide compounds), glycidylamine-type epoxy compounds, alkyl polyol-type epoxy compounds, rubber-modified epoxy compounds, glycidyl ester compounds, etc.

[0052] Examples of commercially available products of the bisphenol A-type epoxy compound include jER828EL and jER1004 (both manufactured by Mitsubishi Chemical Co., Ltd.) and EPICLON EXA-850CRP (manufactured by DIC Corporation).

[0053] As what is marketed among the said bisphenol F type epoxy compounds, jER806, jER4004 (all are manufactured by Mitsubishi Chemical Co., Ltd.), etc. are mentioned, for example.

[0054] As what is marketed among the said bisphenol S type epoxy compounds, EPICLON EXA1514 (made by DIC Corporation) etc. are mentioned, for example.

[0055] As what is marketed among the said 2,2'-diallylbisphenol A type epoxy compounds, RE-810NM (made by Nippon Kayaku Co., Ltd.) etc. are mentioned, for example.

[0056] As what is marketed among the said hydrogenated bisphenol type epoxy compounds, EPICLON EXA7015 (made by DIC Corporation) etc. are mentioned, for example.

[0057] As commercially available products among the above-mentioned propylene oxide-added bisphenol A type epoxy compounds, for example, EP-4000S (manufactured by ADEKA Corporation) etc. can be cited.

[0058] As commercially available products among the above-mentioned resorcinol type epoxy compounds, for example, EX-201 (manufactured by Nagase ChemteX Corporation) etc. can be cited.

[0059] As commercially available products among the above-mentioned biphenyl type epoxy compounds, for example, jER YX-4000H (manufactured by Mitsubishi Chemical Corporation) etc. can be cited.

[0060] As commercially available products among the above-mentioned thioether type epoxy compounds, for example, YSLV-50TE (manufactured by NIPPON STEEL Chemical & Material Co., Ltd.) etc. can be cited.

[0061] As commercially available products among the above-mentioned diphenyl ether type epoxy compounds, for example, YSLV-80DE (manufactured by NIPPON STEEL Chemical & Material Co., Ltd.) etc. can be cited.

[0062] As commercially available products among the above-mentioned dicyclopentadiene type epoxy compounds, for example, EP-4088S (manufactured by ADEKA Corporation) etc. can be cited.

[0063] As commercially available products among the above-mentioned naphthalene type epoxy compounds, for example, EPICLON HP4032, EPICLON EXA-4700 (both manufactured by DIC Corporation) etc. can be cited.

[0064] As commercially available products among the above-mentioned phenol novolac type epoxy compounds, for example, EPICLON N-770 (manufactured by DIC Corporation) etc. can be cited.

[0065] As commercially available products among the above-mentioned o-cresol novolac type epoxy compounds, for example, EPICLON N-670-EXP-S (manufactured by DIC Corporation) etc. can be cited.

[0066] As commercially available products among the above-mentioned dicyclopentadiene novolac type epoxy compounds, for example, EPICLON HP7200 (manufactured by DIC Corporation) etc. can be cited.

[0067] As commercially available products among the above-mentioned biphenol novolac type epoxy compounds, for example, NC-3000P (manufactured by Nippon Kayaku Co., Ltd.) etc. can be cited.

[0068] As commercially available products among the above-mentioned naphthol novolac type epoxy compounds, for example, ESN-165S (manufactured by NIPPON STEEL Chemical & Material Co., Ltd.) etc. can be cited.

[0069] As commercially available products of the above glycidylamine type epoxy compounds, for example, jER630 (manufactured by Mitsubishi Chemical Corporation), EPICLON 430 (manufactured by DIC Corporation), TETRAD-X (manufactured by Mitsubishi Gas Chemical Company), etc. can be cited.

[0070] As commercially available products of the above alkyl polyol type epoxy compounds, for example, ZX-1542 (manufactured by NIPPON STEEL Chemical & Material Co., Ltd.), EPICLON 726 (manufactured by DIC Corporation), Epolight 80MFA (manufactured by Kyoeisha Chemical Co., Ltd.), Denacol EX-611 (manufactured by Nagase ChemteX Corporation), etc. can be cited.

[0071] As commercially available products of the above rubber-modified type epoxy compounds, for example, YR-450, YR-207 (both manufactured by NIPPON STEEL Chemical & Material Co., Ltd.), Epolead PB (manufactured by Daicel Corporation), etc. can be cited.

[0072] As commercially available products of the above glycidyl ester compounds, for example, Denacol EX-147 (manufactured by Nagase ChemteX Corporation), etc. can be cited.

[0073] As other commercially available products of the above epoxy compounds, for example, YDC-1312, YSLV-80XY, YSLV-90CR (all manufactured by NIPPON STEEL Chemical & Material Co., Ltd.), XAC4151 (manufactured by Asahi Kasei Corporation), jER1031, jER1032 (both manufactured by Mitsubishi Chemical Corporation), EXA-7120 (manufactured by DIC Corporation), TEPIC (manufactured by Nissan Chemical Industries, Ltd.), etc. can be cited.

[0074] In addition, the above curable resin may also contain, as the above other curable resin, a compound having an epoxy group and a (meth)acryloyl group in one molecule other than the compound represented by the above formula (1). As such a compound, for example, a partially (meth)acrylic acid-modified epoxy compound obtained by reacting a part of the epoxy groups of an epoxy compound having two or more epoxy groups in one molecule with (meth)acrylic acid, etc. can be cited.

[0075] Examples of the above-mentioned (meth)acrylic acid-based compounds include (meth)acrylate compounds, epoxy (meth)acrylates, urethane (meth)acrylates, etc. Among them, epoxy (meth)acrylates are preferred. In addition, from the viewpoint of reactivity, it is preferred that the above-mentioned (meth)acrylic acid-based compound has two or more (meth)acryloyl groups in one molecule.

[0076] It should be noted that in this specification, the above-mentioned "(meth)acrylate" refers to acrylate or methacrylate, and the above-mentioned "epoxy (meth)acrylate" refers to a compound obtained by reacting all epoxy groups in an epoxy compound with (meth)acrylic acid.

[0077] Examples of the monofunctional compounds among the above-mentioned (meth)acrylate compounds include: methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, isomyristyl (meth)acrylate, stearyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyloxy (meth)acrylate, benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, methoxyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, ethyl carbitol (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 1H,1H,5H-octafluoropentyl (meth)acrylate, imide (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, succinic acid-2-(meth)acryloyloxyethyl ester, hexahydrophthalic acid-2-(meth)acryloyloxyethyl ester, 2-(meth)acryloyloxyethyl 2-hydroxypropyl phthalate, 2-(meth)acryloyloxyethyl phosphate, glycidyl (meth)acrylate, etc.

[0078] In addition, as the difunctional compounds among the above (meth)acrylate compounds, examples include: 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, bisphenol A epoxide adduct di(meth)acrylate, bisphenol A propylene oxide adduct di(meth)acrylate, bisphenol F epoxide adduct di(meth)acrylate, dimethylol dicyclopentadienyl di(meth)acrylate, ethylene oxide-modified isocyanuric acid di(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate, carbonate diol di(meth)acrylate, polyether diol di(meth)acrylate, polyester diol di(meth)acrylate, polycaprolactone diol di(meth)acrylate, polybutadiene diol di(meth)acrylate, etc.

[0079] In addition, as the compounds with three or more functional groups among the above (meth)acrylate compounds, examples include: trimethylolpropane tri(meth)acrylate, ethylene oxide adduct trimethylolpropane tri(meth)acrylate, propylene oxide adduct trimethylolpropane tri(meth)acrylate, caprolactone-modified trimethylolpropane tri(meth)acrylate, ethylene oxide adduct isocyanuric acid tri(meth)acrylate, glycerol tri(meth)acrylate, propylene oxide adduct glycerol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tris(meth)acryloyloxyethyl phosphate, bis(trimethylolpropane) tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc.

[0080] As the above epoxy (meth)acrylate, examples include: epoxy (meth)acrylate obtained by reacting an epoxide compound with (meth)acrylic acid in the presence of a basic catalyst by a conventional method, etc. As the epoxide compound that is the raw material for the above epoxy (meth)acrylate, examples include the epoxide compounds cited as the above other curable resins, etc.

[0081] Examples of commercially available products among the above epoxy (meth)acrylates include epoxy (meth)acrylates manufactured by Daicel·ALLNEX, epoxy (meth)acrylates manufactured by Shin-Nakamura Chemical Co., Ltd., epoxy (meth)acrylates manufactured by Kyoeisha Chemical Co., Ltd., epoxy (meth)acrylates manufactured by Nagase ChemteX Corporation, etc.

[0082] Examples of the epoxy (meth)acrylate manufactured by Daicel·ALLNEX include EBECRYL860, EBECRYL3200, EBECRYL3201, EBECRYL3412, EBECRYL3600, EBECRYL3700, EBECRYL3701, EBECRYL3702, EBECRYL3703, EBECRYL3708, EBECRYL3800, EBECRYL6040, EBECRYL RDX63182, etc.

[0083] Examples of the epoxy (meth)acrylate manufactured by Shin-Nakamura Chemical Co., Ltd. include EA-1010, EA-1020, EA-5323, EA-5520, EA-CHD, EMA-1020, etc.

[0084] Examples of the epoxy (meth)acrylate manufactured by Kyoeisha Chemical Co., Ltd. include Epoxy EsterM-600A, Epoxy Ester 40EM, Epoxy Ester 70PA, Epoxy Ester 200PA, Epoxy Ester 80MFA, Epoxy Ester 3002M, Epoxy Ester 3002A, Epoxy Ester 1600A, Epoxy Ester 3000M, EpoxyEster 3000A, Epoxy Ester 200EA, Epoxy Ester 400EA, etc.

[0085] Examples of the epoxy (meth)acrylate manufactured by Nagase ChemteX Corporation include DenacolAcrylate DA-141, Denacol Acrylate DA-314, Denacol Acrylate DA-911, etc.

[0086] The above urethane (meth)acrylate can be obtained, for example, by reacting a (meth)acrylic acid derivative having a hydroxyl group with a polyfunctional isocyanate compound in the presence of a catalytic amount of a tin-based compound.

[0087] As the above-mentioned polyfunctional isocyanate compounds, for example, there can be mentioned: isophorone diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diphenylmethane-4,4'-diisocyanate (MDI), hydrogenated MDI, polymeric MDI, 1,5-naphthalene diisocyanate, norbornane diisocyanate, dimethylbiphenyl diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, lysine diisocyanate, triphenylmethane triisocyanate, tris(isocyanatophenyl) thiophosphate, tetramethylxylylene diisocyanate, 1,6,11-undecane triisocyanate, etc.

[0088] In addition, as the above-mentioned polyfunctional isocyanate compounds, chain-extended polyfunctional isocyanate compounds obtained by the reaction of a polyol with an excessive amount of a polyfunctional isocyanate compound can also be used.

[0089] As the above-mentioned polyol, for example, there can be mentioned ethylene glycol, propylene glycol, glycerol, sorbitol, trimethylolpropane, carbonate diol, polyether diol, polyester diol, polycaprolactone diol, etc.

[0090] As the above-mentioned (meth)acrylic acid derivative having a hydroxyl group, for example, there can be mentioned: hydroxyalkyl mono(meth)acrylate, mono(meth)acrylate of a diol, mono(meth)acrylate or di(meth)acrylate of a triol, epoxy(meth)acrylate, etc.

[0091] As the above-mentioned hydroxyalkyl mono(meth)acrylate, for example, there can be mentioned 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc.

[0092] As the above-mentioned diol, for example, there can be mentioned ethylene glycol, propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, polyethylene glycol, etc.

[0093] As the above-mentioned triol, for example, there can be mentioned trimethylolethane, trimethylolpropane, glycerol, etc.

[0094] As the above-mentioned epoxy(meth)acrylate, for example, there can be mentioned bisphenol A type epoxy acrylate, etc.

[0095] As commercially available products among the above-mentioned urethane (meth)acrylates, for example, there can be mentioned: urethane (meth)acrylates manufactured by Toagosei Co., Ltd., urethane (meth)acrylates manufactured by Daicel·ALLNEX Co., Ltd., urethane (meth)acrylates manufactured by Negami Kogyo Co., Ltd., urethane (meth)acrylates manufactured by Shin-Nakamura Chemical Co., Ltd., urethane (meth)acrylates manufactured by Kyoeisha Chemical Co., Ltd., etc.

[0096] As the urethane (meth)acrylate manufactured by the above-mentioned Toagosei Co., Ltd., for example, there can be mentioned M-1100, M-1200, M-1210, M-1600, etc.

[0097] As the urethane (meth)acrylate manufactured by the above-mentioned Daicel·ALLNEX Co., Ltd., for example, there can be mentioned EBECRYL 210, EBECRYL 220, EBECRYL 230, EBECRYL 270, EBECRYL 1290, EBECRYL 2220, EBECRYL 4827, EBECRYL 4842, EBECRYL 4858, EBECRYL 5129, EBECRYL 6700, EBECRYL 8402, EBECRYL 8803, EBECRYL 8804, EBECRYL 8807, EBECRYL 9260, etc.

[0098] As the urethane (meth)acrylate manufactured by the above-mentioned Negami Kogyo Co., Ltd., for example, there can be mentioned ArtResin UN-330, ArtResin SH-500B, ArtResin UN-1200TPK, ArtResin UN-1255, ArtResin UN-3320HB, ArtResin UN-7100, ArtResin UN-9000A, ArtResin UN-9000H, etc.

[0099] As the urethane (meth)acrylate manufactured by the above-mentioned Shin-Nakamura Chemical Co., Ltd., for example, there can be mentioned: U-2HA, U-2PHA, U-3HA, U-4HA, U-6H, U-6HA, U-6LPA, U-10H, U-15HA, U-108, U-108A, U-122A, U-122P, U-324A, U-340A, U-340P, U-1084A, U-2061BA, UA-340P, UA-4000, UA-4100, UA-4200, UA-4400, UA-5201P, UA-7100, UA-7200, UA-W2A, etc.

[0100] Examples of the urethane (meth)acrylate manufactured by the abovementioned Kyoeisha Chemical Co., Ltd. include AH-600, AI-600, AT-600, UA-101I, UA-101T, UA-306H, UA-306I, UA-306T, etc.

[0101] When the ratio of the number of epoxy groups in one molecule of the compound contained in the above curable resin to the total of the number of epoxy groups and the number of (meth)acryloyl groups in one molecule of the compound is defined as P E in terms of the P E in the whole of the above curable resin, the preferred lower limit of the epoxy functional group ratio expressed by the mass average value is 30%. By setting the above epoxy functional group ratio to 30% or more, it becomes easier for the low-speed compression shear adhesive strength after the above photocuring and the storage modulus after the above photocuring to be in the above ranges. The more preferred lower limit of the above epoxy functional group ratio is 35%.

[0102] In addition, from the viewpoints such as low liquid crystal contamination, the preferred upper limit of the above epoxy functional group ratio is 50%, and the more preferred upper limit is 45%.

[0103] The sealant for liquid crystal display elements of the present invention contains a photopolymerization initiator.

[0104] Examples of the above photopolymerization initiator include benzophenone compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin ether compounds, thioxanthone compounds, etc.

[0105] Specifically, examples of the above photopolymerization initiator include: 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-((4-methylphenyl)methyl)-1-(4-(4-morpholinyl)phenyl)-1-butanone, 2,2-dimethoxy-1,2-diphenylethane-1-one, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 1-(4-(2-hydroxyethoxy)phenyl)-2-hydroxy-2-methyl-1-propan-1-one, 1-(4-(phenylthio)phenyl)-1,2-octanedione 2-(O-benzoyl oxime), 2-(acetyloxyimino)-1-(4-(4-(2-hydroxyethoxy)phenylthio)phenyl)propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4-dimethylthioxanthen-9-one, etc.

[0106] With respect to 100 parts by mass of the above curable resin, the preferable lower limit of the content of the above photoinitiator is 0.01 part by mass, and the preferable upper limit is 10 parts by mass. By making the content of the above photoinitiator within this range, the storage stability and photocurability of the obtained sealant for liquid crystal display elements become more excellent. The more preferable lower limit of the content of the above photoinitiator is 0.1 part by mass, and the more preferable upper limit is 5 parts by mass.

[0107] The sealant for liquid crystal display elements of the present invention may contain a thermal polymerization initiator.

[0108] As the above thermal polymerization initiator, for example, thermal polymerization initiators formed from azo compounds, organic peroxides, etc. can be cited. Among them, a polymer azo initiator formed from a polymer azo compound is preferable.

[0109] The above thermal polymerization initiator can be used alone or in combination of two or more.

[0110] It should be noted that in this specification, the above "polymer azo compound" refers to a compound having an azo group, generating free radicals by heat, and having a number average molecular weight of 300 or more.

[0111] The preferable lower limit of the number average molecular weight of the above polymer azo compound is 1000, and the preferable upper limit is 300,000. By making the number average molecular weight of the above polymer azo compound within this range, liquid crystal contamination can be suppressed, and it is easy to mix with the curable resin. The more preferable lower limit of the number average molecular weight of the above polymer azo compound is 5000, the more preferable upper limit is 100,000, the further preferable lower limit is 10,000, and the further preferable upper limit is 90,000.

[0112] As the above polymer azo compound, for example, a polymer azo compound having a structure in which a plurality of units such as polyalkylene oxide and polydimethylsiloxane are bonded via an azo group can be cited.

[0113] As the above polymer azo compound having a structure in which a plurality of units such as polyalkylene oxide are bonded via an azo group, a polymer azo compound having a polyethylene oxide structure is preferable.

[0114] Specifically, as the above polymer azo compound, for example, a condensate of 4,4'-azobis(4-cyanovaleric acid) and polyalkylene glycol, a condensate of 4,4'-azobis(4-cyanovaleric acid) and polydimethylsiloxane having a terminal amino group, etc. can be cited.

[0115] Examples of commercially available products of the above polymer azo compounds include VPE-0201, VPE-0401, VPE-0601, VPS-0501, VPS-1001 (all manufactured by Fujifilm Wako Pure Chemical Corporation), etc.

[0116] In addition, examples of azo compounds that are not polymers include V-65, V-501 (both manufactured by Fujifilm Wako Pure Chemical Corporation), etc.

[0117] Examples of the above organic peroxides include ketone peroxides, ketal peroxides, hydrogen peroxide, dialkyl peroxides, peresters, diacyl peroxides, peroxydicarbonates, etc.

[0118] With respect to 100 parts by mass of the above curable resin, the preferred lower limit of the content of the above thermal polymerization initiator is 0.05 part by mass, and the preferred upper limit is 10 parts by mass. By making the content of the above thermal polymerization initiator 0.05 part by mass or more, the thermal curability of the sealant for liquid crystal display elements of the present invention becomes more excellent. By making the content of the above thermal polymerization initiator 10 parts by mass or less, the low liquid crystal contamination property and storage stability of the sealant for liquid crystal display elements of the present invention become more excellent. The more preferred lower limit of the content of the above thermal polymerization initiator is 0.1 part by mass, and the more preferred upper limit is 5 parts by mass.

[0119] The sealant for liquid crystal display elements of the present invention preferably contains a thermal curing agent.

[0120] Examples of the above thermal curing agents include organic acid hydrazides, imidazole derivatives, amine compounds, polyphenol-based compounds, acid anhydrides, etc. Among them, organic acid hydrazides are preferably used.

[0121] Examples of the above organic acid hydrazides include sebacic dihydrazide, isophthalic dihydrazide, adipic dihydrazide, malonic dihydrazide, etc.

[0122] Examples of commercially available products of the above organic acid hydrazides include organic acid hydrazides manufactured by Otsuka Chemical Co., Ltd., organic acid hydrazides manufactured by Ajinomoto Fine-Techno Co., Inc., organic acid hydrazides manufactured by Japan Finechem Co., Ltd., etc.

[0123] Examples of the above organic acid hydrazides manufactured by Otsuka Chemical Co., Ltd. include SDH, ADH, etc.

[0124] Examples of the above organic acid hydrazides manufactured by Ajinomoto Fine-Techno Co., Inc. include AJICURE VDH, AJICURE VDH-J, AJICURE UDH, AJICURE UDH-J, etc.

[0125] As the organic acid hydrazide manufactured by the above-mentioned Japan Finechem Co., Ltd., for example, MDH etc. can be cited.

[0126] With respect to 100 parts by mass of the above-mentioned curable resin, the preferable lower limit of the content of the above-mentioned thermal curing agent is 1 part by mass, and the preferable upper limit is 50 parts by mass. By making the content of the above-mentioned thermal curing agent within this range, the sealant for liquid crystal display elements obtained thereby maintains storage stability and coatability, and the thermal curability becomes more excellent. The more preferable upper limit of the content of the above-mentioned thermal curing agent is 30 parts by mass.

[0127] The sealant for liquid crystal display elements of the present invention preferably contains an organic filler. By containing the above-mentioned organic filler, it becomes easier to make the low-speed compression shear bond strength after photo-curing and the storage modulus after photo-curing within the above-mentioned ranges.

[0128] As the above-mentioned organic filler, for example, polyester fine particles, polyurethane fine particles, vinyl polymer fine particles, (meth)acrylic polymer fine particles etc. can be cited. In addition, the above-mentioned organic filler may have a core-shell structure. Among them, (meth)acrylic polymer fine particles having a core-shell structure are preferable.

[0129] The preferable lower limit of the average particle diameter of the above-mentioned organic filler is 0.1 μm, and the preferable upper limit is 0.8 μm. By making the average particle diameter of the above-mentioned organic filler within this range, it becomes easier to make the low-speed compression shear bond strength after photo-curing and the storage modulus after photo-curing within the above-mentioned ranges. The more preferable upper limit of the average particle diameter of the above-mentioned organic filler is 0.5 μm.

[0130] It should be noted that the average particle diameter of the above-mentioned organic filler can be measured, for example, by using a particle size distribution measuring device and dispersing the above-mentioned organic filler in a solvent (such as water, an organic solvent, etc.). As the above-mentioned particle size distribution measuring device, for example, NICOMP 380ZLS (manufactured by PARTICLE SIZING SYSTEMS) etc. can be cited.

[0131] With respect to 100 parts by mass of the above-mentioned curable resin, the preferable lower limit of the content of the above-mentioned organic filler is 5 parts by mass. By making the content of the above-mentioned organic filler 5 parts by mass or more, it becomes easier to make the low-speed compression shear bond strength after photo-curing and the storage modulus after photo-curing within the above-mentioned ranges. The more preferable lower limit of the content of the above-mentioned organic filler is 10 parts by mass.

[0132] In addition, from the viewpoints of coatability etc., the preferable upper limit of the content of the above-mentioned organic filler is 40 parts by mass, and the more preferable upper limit is 30 parts by mass.

[0133] For the purposes of improving moisture-proof permeability, increasing viscosity, improving adhesion based on stress dispersion effects, improving the coefficient of linear expansion, etc., the sealant for liquid crystal display elements of the present invention preferably contains the above-mentioned inorganic filler. However, when a large amount of the above-mentioned inorganic filler is contained, it is difficult to make the low-speed compression shear adhesion strength after photocuring and the storage modulus after photocuring within the above ranges.

[0134] Examples of the above-mentioned inorganic filler include silica, talc, glass beads, asbestos, gypsum, diatomaceous earth, montmorillonite, bentonite, montmorillonite, sericite, activated clay, alumina, zinc oxide, 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.

[0135] With respect to 100 parts by mass of the above-mentioned curable resin, the lower limit of the content of the above-mentioned inorganic filler is preferably 5 parts by mass, and the upper limit is preferably 30 parts by mass. By making the content of the above-mentioned inorganic filler 5 parts by mass or more, the effects such as improvement of moisture-proof permeability become more excellent. By making the content of the above-mentioned inorganic filler 30 parts by mass or less, it becomes easier to make the low-speed compression shear adhesion strength after photocuring and the storage modulus after photocuring within the above ranges. The more preferable lower limit of the content of the above-mentioned inorganic filler is 10 parts by mass, and the more preferable upper limit is 25 parts by mass.

[0136] The sealant for liquid crystal display elements of the present invention preferably contains a silane coupling agent. The above-mentioned silane coupling agent mainly functions as an adhesion aid for bonding the sealant for liquid crystal display elements to a substrate or the like well.

[0137] Examples of the above-mentioned silane coupling agent include 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, etc.

[0138] The lower limit of the content of the above-mentioned silane coupling agent in 100 parts by mass of the sealant for liquid crystal display elements of the present invention is preferably 0.1 part by mass, and the upper limit is preferably 10 parts by mass. By making the content of the above-mentioned silane coupling agent within this range, the occurrence of liquid crystal contamination is suppressed, and the effect of improving adhesion becomes more excellent. The more preferable lower limit of the content of the above-mentioned silane coupling agent is 0.3 part by mass, and the more preferable upper limit is 5 parts by mass.

[0139] The sealant for liquid crystal display elements of the present invention may contain a light-shielding agent. By containing the above-mentioned light-shielding agent, the sealant for liquid crystal display elements of the present invention can be suitably used as a light-shielding sealant.

[0140] Examples of the above-mentioned light-shielding agent include iron oxide, titanium black, aniline black, cyanine black, fullerene, carbon black, resin-coated carbon black, etc. Among them, titanium black is preferred.

[0141] The above titanium black is a substance with a higher transmittance for light in the vicinity of the ultraviolet region, particularly for light with a wavelength of 370 nm or more and 450 nm or less, compared to the average transmittance for light with a wavelength of more than 300 nm and less than 800 nm. That is, the above titanium black is a light-shielding agent having the following properties: by sufficiently shielding light with a wavelength in the visible light region, light-shielding properties are imparted to the sealant for a liquid crystal display element of the present invention, and on the other hand, light with a wavelength in the vicinity of the ultraviolet region is transmitted. Therefore, as the above photoinitiator, by using a photoinitiator capable of initiating a reaction with light having a wavelength (370 nm or more and 450 nm or less) with which the transmittance of the above titanium black becomes higher, the photocurability of the sealant for a liquid crystal display element of the present invention can be further increased. In addition, as the light-shielding agent contained in the sealant for a liquid crystal display element of the present invention, a substance with high insulation is preferred, and titanium black is also suitable as the light-shielding agent with high insulation.

[0142] The optical density (OD value) per 1 μm of the above titanium black is preferably 3 or more, more preferably 4 or more. The higher the light-shielding property of the above titanium black, the better. The upper limit of the preferred OD value of the above titanium black is not particularly limited, and is usually 5 or less.

[0143] The above titanium black exhibits sufficient effects even without surface treatment, but titanium black whose surface is treated with an organic component such as a coupling agent; titanium black coated with an inorganic component such as silica, titanium oxide, germanium oxide, alumina, zirconia, or magnesia; or surface-treated titanium black can also be used. Among them, from the aspect of being able to further improve the insulation, titanium black treated with an organic component is preferred.

[0144] In addition, a liquid crystal display element manufactured using the sealant for a liquid crystal display element of the present invention containing the above titanium black as a light-shielding agent has sufficient light-shielding properties, and thus a liquid crystal display element without light leakage, having a high contrast, and having excellent image display quality can be realized.

[0145] As commercially available products of the above titanium black, for example, titanium black manufactured by Mitsubishi Materials Corporation, titanium black manufactured by Ako Kasei Co., Ltd., etc. can be cited.

[0146] As the titanium black manufactured by Mitsubishi Materials Corporation, for example, 12S, 13M, 13M-C, 13R-N, 14M-C, etc. can be cited.

[0147] As the titanium black manufactured by Ako Kasei Co., Ltd., for example, Tilack D, etc. can be cited.

[0148] The lower limit of the preferred specific surface area of the above titanium black is 13 m 2 / g, and the upper limit of the preference is 30 m2 / g, and a more preferred lower limit is 15 m 2 / g, and a more preferred upper limit is 25 m 2 / g.

[0149] In addition, the preferred lower limit of the volume resistivity of the above 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.

[0150] The primary particle size of the above light-shielding agent is not particularly limited as long as it is equal to or less than 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 making the primary particle size of the above light-shielding agent within this range, the light-shielding property can be made more excellent without deteriorating the coatability of the resulting sealant for liquid crystal display elements. The more preferred lower limit of the primary particle size of the above light-shielding agent is 5 nm, the more preferred upper limit is 200 nm, the further preferred lower limit is 10 nm, and the further preferred upper limit is 100 nm.

[0151] It should be noted that the primary particle size of the above light-shielding agent can be measured by using NICOMP 380ZLS (manufactured by PARTICLESIZING SYSTEMS) and dispersing the above light-shielding agent in a solvent (such as water, organic solvent, etc.).

[0152] The preferred lower limit of the content of the above light-shielding agent in 100 parts by mass of the sealant for liquid crystal display elements of the present invention is 5 parts by mass, and the preferred upper limit is 80 parts by mass. By making the content of the above light-shielding agent within this range, the adhesiveness, strength after curing, and drawability of the resulting sealant for liquid crystal display elements will not be reduced, and the effect of improving the light-shielding property can be further exerted. The more preferred lower limit of the content of the above light-shielding agent is 10 parts by mass, the more preferred upper limit is 70 parts by mass, the further preferred lower limit is 30 parts by mass, and the further preferred upper limit is 60 parts by mass.

[0153] The sealant for liquid crystal display elements of the present invention may further contain additives such as a stress relaxant, a reactive diluent, a curing accelerator, an antifoaming agent, a leveling agent, and a polymerization inhibitor as needed.

[0154] As a method for manufacturing the sealant for liquid crystal display elements of the present invention, for example, there can be mentioned a method of using a mixer to mix a curable resin, a photoinitiator, and other components such as an organic filler and an inorganic filler.

[0155] As the above mixer, for example, there can be mentioned a homogenizing disperser, a homogenizing mixer, a universal mixer, a planetary mixer, a kneader, a three-roll mill, etc.

[0156] In addition, by incorporating conductive particles into the sealant for liquid crystal display elements of the present invention, an upper and lower conduction material can be manufactured.

[0157] As the above-mentioned conductive particles, metal balls, conductive particles having a conductive metal layer formed on the surface of resin particles, etc. can be used. Among them, the conductive particles having a conductive metal layer formed on the surface of resin particles are suitable because they can make conductive connections without damaging the transparent substrate, etc. by utilizing the excellent elasticity of the resin particles.

[0158] As a method for manufacturing a liquid crystal display element using the sealant for liquid crystal display elements of the present invention, a liquid crystal droplet process is preferably used. Specifically, for example, a method having the following respective steps, etc. can be cited.

[0159] First, the following steps are carried out: on one of the two transparent substrates having electrodes such as an ITO film and an alignment film, the sealant for liquid crystal display elements of the present invention is coated by screen printing, dispenser coating, etc. to form a frame-shaped sealing pattern. Next, a step of dropping and coating minute droplets of liquid crystal over the entire surface inside the frame of the sealing pattern and overlapping another transparent substrate under vacuum is carried out. Then, by carrying out a step of temporarily curing the sealant by irradiating light such as ultraviolet rays on the sealing pattern portion (light curing step), and a step of heating the temporarily cured sealant to formally cure it (thermal curing step), a liquid crystal display element can be obtained.

[0160] Advantages of the Invention

[0161] According to the present invention, a sealant for liquid crystal display elements can be provided which has excellent adhesiveness to the alignment film and moisture-proof permeability, and can suppress peeling after light curing even when coated on a large substrate. Detailed Description of Embodiments

[0162] Hereinafter, examples will be cited to more specifically illustrate the present invention, but the present invention is not limited to these examples.

[0163] (Production of curable resin A)

[0164] 116 parts by mass of 2-hydroxyethyl acrylate, 114 parts by mass of ε-caprolactone, and 0.5 part by mass of hydroquinone as a polymerization inhibitor were added to a reaction flask, and the mixture was stirred at 90 °C for 5 hours using a mantle heater. Then, 148 parts by mass of phthalic anhydride was added, and stirring was continued for 5 hours. Next, 340 parts by mass of bisphenol A diglycidyl ether was added to the obtained reaction product, and further 0.5 part by mass of triphenylphosphine was added, and the mixture was stirred at 110 °C for 5 hours, whereby curable resin A was obtained.

[0165] By 1 H-NMR and 1313C-NMR confirmed that the curable resin A contains 50% by mass of the compound represented by the following formula (3), 25% by mass of the compound represented by the following formula (4), and 25% by mass of bisphenol A diglycidyl ether (P of the curable resin A E can be regarded as 0.5).

[0166] [Chemical formula 3]

[0167]

[0168] [Chemical formula 4]

[0169]

[0170] (Production of curable resin B)

[0171] The blending amount of ε-caprolactone was set to 228 parts by mass, and otherwise, the same operations as in the above “(Production of curable resin A)” were carried out to obtain curable resin B.

[0172] By 1 1H-NMR and 13 13C-NMR, it was confirmed that the curable resin B contains 50% by mass of the compound represented by the following formula (5), 25% by mass of the compound represented by the following formula (6), and 25% by mass of bisphenol A diglycidyl ether (P of the curable resin B E can be regarded as 0.5).

[0173] [Chemical formula 5]

[0174]

[0175] [Chemical formula 6]

[0176]

[0177] (Production of curable resin C)

[0178] The blending amount of bisphenol A diglycidyl ether was set to 170 parts by mass, and otherwise, the same operations as in the above “(Production of curable resin A)” were carried out to obtain curable resin C.

[0179] By 1 1H-NMR and 13 13C-NMR, it was confirmed that the curable resin C is the compound represented by the above formula (4).

[0180] (Production of curable resin D)

[0181] The compounding quantity of ε-caprolactone was set to 228 parts by mass, and the compounding quantity of bisphenol A diglycidyl ether was set to 170 parts by mass. Other than this, the operation was carried out in the same manner as in the above “(Production of curable resin A)” to obtain curable resin D.

[0182] By 1 1H-NMR and 13 13C-NMR, it was confirmed that curable resin D was the compound represented by the above formula (6).

[0183] (Examples 1 to 13, Comparative Examples 1 to 9)

[0184] According to the compounding ratios described in Tables 1 and 2, each material was stirred with a planetary stirring device and then uniformly mixed with a ceramic three-roll mill to obtain sealants for liquid crystal display elements of Examples 1 to 13 and Comparative Examples 1 to 9. As the planetary stirring device, Awatori Rentaro (manufactured by THINKY Corporation) was used.

[0185] The epoxy functional group ratios of the curable resins in the obtained sealants for each liquid crystal display element are shown in Tables 1 and 2.

[0186] (Low-speed compression shear bond strength after photocuring)

[0187] Onto one of two polyimide substrates having a length of 45 mm, a width of 25 mm, and a thickness of 0.7 mm, the obtained sealant for liquid crystal display elements was dropwise dispensed so that the diameter at the time of bonding became 3 mm. The other polyimide substrate was overlapped on the polyimide substrate dropwise dispensed with the sealant with a 10 mm offset in the length direction by means of the sealant. Then, ultraviolet rays with a wavelength of 365 nm and an illuminance of 100 mW / cm 2 2 were irradiated for 30 seconds (cumulative light quantity: 3000 mJ / cm 2 ) using a metal halide lamp to obtain a test piece having a cured product of the sealant with a thickness of 5.0 μm. As the metal halide lamp, SE-1500M (manufactured by SENLIGHTS Corporation) was used, and the irradiation of ultraviolet rays was carried out by means of a 340 nm cut-off filter (manufactured by Asahi Spectra Co., Ltd.). For the obtained test piece, the compression shear bond strength (low-speed compression shear bond strength) was measured at 25°C and a shear rate of 1 mm / sec using Autograph AGX (manufactured by Shimadzu Corporation) in accordance with JIS K 6852.

[0188] The results are shown in Tables 1 and 2.

[0189] (Storage modulus after photocuring)

[0190] For each of the obtained sealants for liquid crystal display elements, ultraviolet light with a wavelength of 365 nm and an illuminance of 100 mW / cm 2 was irradiated for 30 seconds (cumulative light amount: 3000 mJ / cm 2 ) using a metal halide lamp to obtain a cured product. As the metal halide lamp, SE-1500M (manufactured by SEN LIGHTS Corporation) was used, and the irradiation of ultraviolet light was carried out with a 340 nm cut-off filter (manufactured by Asahi Spectra Co., Ltd.). For the obtained cured product, a dynamic viscoelasticity measuring device was used to perform dynamic viscoelasticity measurement under the conditions of a tensile mode, a test piece width of 5 mm, a thickness of 0.35 mm, a gripping width of 25 mm, a heating rate of 10 °C / minute, and a frequency of 5 Hz, and the storage modulus at 25 °C was measured.

[0191] The results are shown in Tables 1 and 2.

[0192] <Evaluation>

[0193] The following evaluations were performed on the sealants for liquid crystal display elements obtained in the examples and comparative examples. The results are shown in Tables 1 and 2.

[0194] (Adhesion to the alignment film)

[0195] An imide resin was coated on a glass substrate with an ITO film by spin coating, pre-baked at 80 °C, and then fired at 230 °C to fabricate a substrate with an alignment film. As the imide resin, SE7492 (manufactured by Nissan Chemical Industries, Ltd.) was used. The thickness of the obtained alignment film (imide alignment film) was 100 nm.

[0196] With respect to 100 parts by mass of each of the sealants for liquid crystal display elements obtained in the examples and comparative examples, 1 part by mass of silica spacers was uniformly dispersed using a planetary stirring device. As the silica spacers, SI-H055 (manufactured by Sekisui Chemical Co., Ltd.) was used. Next, the sealant in which the silica spacers were dispersed was micro-dropwise applied onto the alignment film of the substrate with the alignment film. On the substrate with the alignment film onto which the sealant was dropwise applied, another substrate with an alignment film was adhered in a cross shape with the sealant, and ultraviolet light with a wavelength of 365 nm and an illuminance of 100 mW / cm 2 was irradiated for 30 seconds (cumulative light amount: 3000 mJ / cm 2After that, it was heated at 120°C for 1 hour to obtain an adhesion test piece. As the metal halide lamp, SE-1500M (manufactured by SEN LIGHTS Corporation) was used, and ultraviolet irradiation was carried out with a 340 nm cut-off filter (manufactured by Asahi Spectra Co., Ltd.). When a metal cylinder with a radius of 5 mm was pressed into the end of the substrate of the manufactured adhesion test piece at a speed of 5 mm / min, the strength at the time of panel peeling was measured. The case where the value obtained by dividing the obtained measured value (kgf) by the sealing diameter (cm) was 3.0 kgf / cm or more was denoted as "◎", the case where it was 2.5 kgf / cm or more and less than 3.0 kgf / cm was denoted as "○", the case where it was 2.0 kgf / cm or more and less than 2.5 kgf / cm was denoted as "△", and the case where it was less than 2.0 kgf / cm was denoted as "×", and the adhesion to the alignment film was evaluated.

[0197] (Water vapor transmission rate)

[0198] Each liquid crystal display element obtained in the examples and comparative examples was coated on a smooth release film using a coater. Next, ultraviolet rays with a wavelength of 365 nm and an illuminance of 100 mW / cm 2 were irradiated for 30 seconds (cumulative light amount: 3000 mJ / cm 2 ) with a metal halide lamp. After that, it was heated at 120°C for 1 hour to obtain a water vapor transmission rate measurement film with a thickness of 300 μm. As the metal halide lamp, SE-1500M (manufactured by SEN LIGHTS Corporation) was used, and ultraviolet irradiation was carried out with a 340 nm cut-off filter (manufactured by Asahi Spectra Co., Ltd.). A water vapor transmission rate test cup was fabricated by the method of the water vapor transmission rate test method (cup method) for moisture-proof packaging materials according to JIS Z 0208, the obtained water vapor transmission rate measurement film was installed, and it was put into a thermo-hygrostat oven at a temperature of 80°C and a humidity of 90%RH to measure the water vapor transmission rate.

[0199] (Peel resistance after photocuring)

[0200] To 100 parts by mass of the sealant for liquid crystal display elements obtained in the examples and comparative examples, 1 part by mass of silica spacers was added, and it was uniformly dispersed using a planetary stirring device. After performing a defoaming treatment to remove the bubbles in the sealant for liquid crystal display elements, it was filled into a syringe for dispensing, and the defoaming treatment was performed again. As the silica spacers, SI-H055 (manufactured by Sekisui Chemical Co., Ltd.) was used, and as the syringe for dispensing, PSY-10E (manufactured by Musashi Engineering, Inc.) was used. Next, the sealant for liquid crystal display elements was coated on a glass substrate in a frame-drawing manner using a dispenser. As the dispenser, SHOTMASTER300 (manufactured by Musashi Engineering, Inc.) was used. Next, fine droplets of FFS liquid crystal were dropped and coated into the frame of the sealant for liquid crystal display elements using a liquid crystal droplet-dropping device. On the glass substrate on which the FFS liquid crystal was drop-coated, another glass substrate was overlapped with the aid of the sealant for liquid crystal display elements, and the two substrates were bonded under a reduced pressure of 5 Pa using a vacuum bonding device to obtain a cell. As the FFS liquid crystal, JC-5223XX (manufactured by Chisso Corporation) was used. The obtained cell was irradiated with ultraviolet rays having a wavelength of 365 nm and an illuminance of 100 mW / cm 2 for 30 seconds (cumulative light amount: 3000 mJ / cm 2 ) using a metal halide lamp to produce a liquid crystal display element in which the sealant for liquid crystal display elements was cured only by light. As the metal halide lamp, SE-1500M (manufactured by SEN LIGHTS Co., Ltd.) was used, and the irradiation of ultraviolet rays was performed with the aid of a 340 nm cut-off filter (manufactured by Asahi Spectra Co., Ltd.).

[0201] The obtained liquid crystal display element was exposed to an ultrasonic cleaner (manufactured by AS ONE Corporation, "VS-10003", 28 kHz condition) for 10 minutes. The exposed liquid crystal display element was observed under a microscope, and the case where no peeling of the substrate was confirmed was denoted as "○", and the case where peeling of the substrate was confirmed was denoted as "×", and the peel resistance after photocuring was evaluated.

[0202] [Table 1]

[0203]

[0204] [Table 2]

[0205]

[0206] Industrial Applicability

[0207] According to the present invention, it is possible to provide a sealant for liquid crystal display elements that is excellent in adhesiveness to an alignment film and moisture barrier properties, and can suppress peeling after photocuring even when coated on a large substrate.

Claims

1. A sealant for a liquid crystal display element, characterized in that: It contains a curable resin and a photopolymerization initiator. The curable resin includes a compound represented by the following formula (1): For irradiation of 3000mJ / cm 2 The cured product of the sealant for liquid crystal display elements having a thickness of 5.0 μm obtained by irradiating the sealant with ultraviolet light of a wavelength of 365 nm has a compressive shear bonding strength to polyimide measured at 25° C. and a shear rate of 1 mm / sec in accordance with JIS K 6852 of 15 kgf / cm 2 above, In formula (1), R 1 represents a hydrogen atom or a methyl group, R 2 represents a group represented by the following formula (2-1), (2-2) or (2-3), R 3 represents a methylene group, a methylmethylene group, a dimethylmethylene group or a sulfonyl group, X represents a ring-opening structure of a lactone, and n is 1 to 5, In formulae (2-1) to (2-3), * represents a bonding position, in formula (2-2), a is an integer of 1 to 8, in formula (2-3), b is an integer of 1 to 8, c is an integer of 1 to 3, and d is an integer of 1 to 8.

2. The sealing agent for liquid crystal display elements according to claim 1, further comprising an organic filler, The content of the organic filler is 5 parts by mass or more relative to 100 parts by mass of the curable resin.

3. The sealing agent for liquid crystal display elements according to claim 1 or 2, wherein The ratio of the number of epoxy groups in one molecule of the compound contained in the curable resin to the total number of epoxy groups and the number of (meth)acryloyl groups in one molecule of the compound is defined as P. E When the P in the whole curable resin is E The epoxy functional group ratio represented by the mass average value is 30% or more.

4. The sealing agent for liquid crystal display elements according to claim 1, 2 or 3, further comprising an inorganic filler, The content of the inorganic filler is 5 parts by mass or more and 30 parts by mass or less relative to 100 parts by mass of the curable resin.

5. The sealing agent for liquid crystal display elements according to claim 1, 2, 3 or 4, wherein the sealing agent is irradiated with 3000 mJ / cm 2 The cured product with a thickness of 300 μm obtained by irradiating the product with ultraviolet light of 365 nm wavelength and then heating it at 120°C for 1 hour had a moisture permeability of 75 g / m2 as measured in an environment of 80°C and 90% RH according to JIS Z0208. 2 Less than 24 hours.

6. The sealing agent for liquid crystal display element according to claim 1, 2, 3, 4 or 5, wherein the sealing agent is irradiated with 3000 mJ / cm 2 The storage elastic modulus of the cured product obtained by irradiating ultraviolet rays with a wavelength of 365 nm at 25° C. is 3.5 GPa or less.

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