Sealant for liquid crystal display element, and use of curable resin composition as sealant for liquid crystal display element

Abstract

A purpose of the present invention is to provide a sealant for a liquid crystal display element, the sealant having excellent adhesiveness at high temperatures, excellent moisture permeation prevention properties, and extremely low possibility of liquid crystal contamination. Another purpose of the present invention is to provide a method for using a curable resin composition as the sealant for a liquid crystal display element. The present invention provides a sealant for a liquid crystal display element, the sealant containing a curable resin, a radical photopolymerization initiator, and a thermal curing agent. The curable resin contains an epoxy compound and a (meth)acrylic compound that does not have an epoxy group. The (meth)acrylic compound includes a polyfunctional (meth)acrylic compound (X1) which has two or more (meth)acryloyloxy groups in each molecule, and in which the number of atoms constituting a covalent bond that connects one (meth)acryloyloxy group to the other (meth)acryloyloxy group in the shortest distance between the two (meth)acryloyloxy groups that are located at the farthest distance from each other is 1 to 6 inclusive.

Description

Use of a sealant for liquid crystal display elements, and a curable resin composition as a sealant for liquid crystal display elements.

[0001] This invention relates to a sealant for liquid crystal display elements. Furthermore, this invention relates to the use of a curable resin composition as a sealant for said liquid crystal display elements.

[0002] As a method for manufacturing liquid crystal elements, a liquid crystal dropping method called the dropping method, which uses a photothermocurable sealant containing a curable resin, a photopolymerization initiator, and a thermosetting agent, is used, from the viewpoint of shortening the cycle time and optimizing the amount of liquid crystal used, as disclosed in Patent Documents 1 and 2. In the dropping method, first, a rectangular seal pattern is formed on one of two electrode-equipped substrates by dispensing. Next, while the sealant is still uncured, tiny droplets of liquid crystal are dropped into the seal frame of the substrate, the other substrate is placed on top under vacuum, and the sealed area is irradiated with light such as ultraviolet light to perform preliminary curing. After that, heating is performed to perform final curing and to manufacture the liquid crystal element.

[0003] By the way, in today's world where various mobile devices with LCD panels, such as mobile phones and portable game consoles, are widespread, miniaturization of these devices is the most pressing issue. One method of miniaturizing devices is to narrow the bezel of the LCD display, for example, by placing the sticker area below the black matrix (hereinafter also referred to as narrow bezel design).

[0004] Japanese Patent Publication No. 2001-133794, International Publication No. 02 / 092718

[0005] With the increasing performance of liquid crystal display elements, reliability in operation under high temperature and high humidity environments is becoming increasingly important, and sealants with excellent high-temperature adhesion and moisture-proof properties are required. One way to improve the high-temperature adhesion and moisture-proof properties of sealants is to have a high glass transition temperature after curing. To improve the glass transition temperature of the cured sealant, the use of compounds with a rigid structure such as a cross-linked structure as a curable resin has been investigated. However, when compounds with a cross-linked structure are used, there is a problem that the sealant is more likely to contaminate the liquid crystal. In particular, in recent years, with the narrow bezel design, the application width of sealants has become narrower, making it difficult to achieve excellent high-temperature adhesion, moisture-proof properties, and low liquid crystal contamination properties even with sealants that previously had no problems.

[0006] The present invention aims to provide a sealant for liquid crystal display elements that exhibits excellent high-temperature adhesion, moisture permeability prevention, and low liquid crystal contamination. Furthermore, the present invention aims to provide a method for using a curable resin composition as a sealant for liquid crystal display elements.

[0007] Disclosure 1 is a sealant for liquid crystal display elements comprising a curable resin, a photoradical polymerization initiator, and a thermosetting agent, wherein the curable resin comprises a (meth)acrylic compound without epoxy groups and an epoxy compound, the (meth)acrylic compound having two or more (meth)acryloyloxy groups in one molecule, and the number of atoms constituting the shortest covalent bond connecting one (meth)acryloyloxy group to the other (meth)acryloyloxy group at the two furthest relative positions is 1 to 6. Disclosure 3 is a sealant for liquid crystal display elements according to Disclosure 1 or 2, wherein the polyfunctional (meth)acrylic compound (X1) has at least one hydroxyl group in one molecule. Disclosure 4 is a sealant for liquid crystal display elements according to Disclosure 3, wherein the polyfunctional (meth)acrylic compound (X1) is a compound represented by the following formula (1). Disclosure 5 is a sealant for liquid crystal display elements according to any of Disclosures 1 to 4, wherein the content of the polyfunctional (meth)acrylic compound (X1) in 100 parts by mass of the curable resin is 5 parts by mass or more and 42 parts by mass or less. Disclosure 6 is a sealant for liquid crystal display elements containing a curable resin, a photoradical polymerization initiator and a thermosetting agent, wherein the curable resin includes a (meth)acrylic compound that does not have epoxy groups and an epoxy compound, and the (meth)acrylic compound includes a polyfunctional (meth)acrylic compound (X2) having two or more (meth)acryloyloxy groups in one molecule and having a (meth)acryloyloxy group equivalent of 130 or less. Disclosure 7 is a sealant for liquid crystal display elements according to Disclosure 6, wherein the polyfunctional (meth)acrylic compound (X2) has at least one hydroxyl group in one molecule. Disclosure 8 is a sealant for liquid crystal display elements according to Disclosure 6 or 7, wherein the polyfunctional (meth)acrylic compound (X2) is a compound represented by the following formula (2).Disclosure 9 is a sealant for liquid crystal display elements according to any of Disclosures 6 to 8, wherein the content of the polyfunctional (meth)acrylic compound (X2) in 100 parts by mass of the curable resin is 5 parts by mass or more and 42 parts by mass or less. Disclosure 10 is a sealant for liquid crystal display elements according to any of Disclosures 1 to 9, wherein the glass transition temperature of the cured product is 110°C or more and 170°C or less. The present disclosure 11 relates to the use of a curable resin composition containing a curable resin, a photoradical polymerization initiator, and a thermosetting agent, wherein the curable resin includes an epoxy-free (meth)acrylic compound and an epoxy compound, and the (meth)acrylic compound has two or more (meth)acryloyloxy groups in one molecule, and the number of atoms constituting the shortest covalent bond connecting one (meth)acryloyloxy group to the other (meth)acryloyloxy group between the two (meth)acryloyloxy groups that are furthest apart is 1 to 6, as a sealant for liquid crystal display elements. Disclosure 12 relates to the use of a curable resin composition containing a curable resin, a photoradical polymerization initiator, and a thermosetting agent, wherein the curable resin includes a (meth)acrylic compound that does not have epoxy groups and an epoxy compound, and the (meth)acrylic compound has two or more (meth)acryloyloxy groups in one molecule and contains a polyfunctional (meth)acrylic compound (X2) with an (meth)acryloyloxy group equivalent of 130 or less, as a sealant for liquid crystal display elements.

[0008]

[0009] In formula (1), R １ and R ２ Each of these is independently a hydrogen atom or a methyl group, and R ３ ~R ８ Each of these is independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a hydroxyl group, and R ３ ~R ８ At least one of them is a hydroxyl group.

[0010]

[0011] In formula (2), R ９ and R １０is, independently of each other, a hydrogen atom or a methyl group, and R １１ ~R １６ is, independently of each other, a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a hydroxyl group, and R １１ ~R １６ at least one of them is a hydroxyl group.

[0012] The present invention will be described in detail below. Hereinafter, an embodiment of the present invention or one thereof will be referred to as "this embodiment". Further, the sealant for liquid crystal display elements of the present disclosure 1 will be described as the sealant for liquid crystal display elements of "this embodiment 1", the sealant for liquid crystal display elements of the present disclosure 6 will be described as the sealant for liquid crystal display elements of "this embodiment 2", and regarding the matters common to the sealant for liquid crystal display elements of this embodiment 1 and the sealant for liquid crystal display elements of this embodiment 2, they will be described as the sealant for liquid crystal display elements of "this embodiment".

[0013] The inventor has studied using a polyfunctional (meth)acrylic compound having a specific structure as the (meth)acrylic compound in a photo-thermosetting sealant for liquid crystal display elements containing a (meth)acrylic compound and an epoxy compound as curable resins. As a result, it has been found that a sealant for liquid crystal display elements excellent in high-temperature adhesiveness, moisture permeation prevention property, and low liquid crystal contamination property can be obtained, and the invention according to this embodiment 1 has been completed. Further, the inventor has studied using a polyfunctional (meth)acrylic compound having a (meth)acryloyloxy group equivalent of a specific value or less as the (meth)acrylic compound in a photo-thermosetting sealant for liquid crystal display elements containing a (meth)acrylic compound and an epoxy compound as curable resins. As a result, it has been found that a sealant for liquid crystal display elements excellent in high-temperature adhesiveness, moisture permeation prevention property, and low liquid crystal contamination property can be obtained, and the invention according to this embodiment 2 has been completed.

[0014] The sealant for liquid crystal display elements of this embodiment contains a curable resin. The curable resin contains a (meth)acrylic compound having no epoxy group. In the present specification, the above "(meth)acrylic" means acrylic or methacrylic.

[0015] In the sealant for liquid crystal display elements of this embodiment 1, the (meth)acrylic compound includes a polyfunctional (meth)acrylic compound (X1) having two or more (meth)acryloyloxy groups in one molecule, and the number of atoms constituting the shortest covalent bond connecting one (meth)acryloyloxy group to the other (meth)acryloyloxy group at the two furthest relative positions (hereinafter also referred to as "number of atoms at the shortest distance between (meth)acryloyloxy groups") is 1 or more and 6 or less. By containing the above polyfunctional (meth)acrylic compound (X1), the sealant for liquid crystal display elements of this embodiment 1 has excellent high-temperature adhesion, moisture permeability prevention, and low liquid crystal contamination. In this specification, "(meth)acryloyl" means acryloyl or methacryloyl. Furthermore, the phrase "the two (meth)acryloyloxy groups in the furthest relative positions" means, if the polyfunctional (meth)acrylic compound (X1) has only two (meth)acryloyloxy groups, those two (meth)acryloyloxy groups, and if the polyfunctional (meth)acrylic compound (X1) has three or more (meth)acryloyloxy groups, the two (meth)acryloyloxy groups in the furthest relative positions among them.

[0016] The above-mentioned polyfunctional (meth)acrylic compound (X1) has two or more (meth)acryloyloxy groups. In particular, it is preferable that the above-mentioned polyfunctional (meth)acrylic compound (X1) has only two (meth)acryloyloxy groups.

[0017] The polyfunctional (meth)acrylic compound (X1) described above has a minimum distance of 1 to 6 atoms between (meth)acryloyloxy groups. This range of minimum distance between (meth)acryloyloxy groups in the polyfunctional (meth)acrylic compound (X1) results in the liquid crystal display element sealant of this embodiment 1 exhibiting excellent high-temperature adhesion, moisture permeability prevention, and low liquid crystal contamination. Preferably, the minimum distance between (meth)acryloyloxy groups in the polyfunctional (meth)acrylic compound (X1) is 1 to 3. Furthermore, a preferred lower limit for the minimum distance between (meth)acryloyloxy groups in the polyfunctional (meth)acrylic compound (X1) is 2. Note that the "minimum distance between (meth)acryloyloxy groups" does not include the number of atoms contained within the (meth)acryloyloxy group itself. For example, in the case of the compound represented by formula (1) above, one (meth)acryloyloxy group is connected to the other (meth)acryloyloxy group by four covalent bonds, and between the two (meth)acryloyloxy groups, the atoms constituting these four covalent bonds are three carbon atoms. Therefore, the minimum distance of atoms between the (meth)acryloyloxy groups is three, and it becomes the polyfunctional (meth)acrylic compound (X1). Also, for example, in the case of tricyclodecanedimethanol diacrylate represented by formula (3) below, one acryloyloxy group is connected to the other acryloyloxy group by a minimum of eight covalent bonds, and between the two acryloyloxy groups, the atoms constituting these eight covalent bonds are seven carbon atoms. Therefore, the minimum distance of atoms between the (meth)acryloyloxy groups is seven, and it does not become the polyfunctional (meth)acrylic compound (X1). Furthermore, for example, in the case of dipentaerythritol hexaacrylate represented by the following formula (4), the two acryloyloxy groups that are furthest apart are connected by a minimum of eight covalent bonds from one acryloyloxy group to the other. Since the atoms constituting these eight covalent bonds between the two acryloyloxy groups are six carbon atoms and one oxygen atom, the minimum distance between the (meth)acryloyloxy groups is seven, and it does not become the polyfunctional (meth)acrylic compound (X1).In this specification, "(meth)acrylate" means acrylate or methacrylate.

[0018]

[0019]

[0020] The polyfunctional (meth)acrylic compound (X1) described above has a preferred upper limit of 130 (meth)acryloyloxy group equivalents. When the (meth)acryloyloxy group equivalents of the polyfunctional (meth)acrylic compound (X1) are 130 or less, the resulting sealant for liquid crystal display elements exhibits superior high-temperature adhesion, moisture permeability prevention, and low liquid crystal contamination. A more preferred upper limit of 120 (meth)acryloyloxy group equivalents of the polyfunctional (meth)acrylic compound (X1) described above has a preferred lower limit of 92 (meth)acryloyloxy group equivalents of the polyfunctional (meth)acrylic compound (X1) described above has a preferred lower limit. In this specification, "(meth)acryloyloxy group equivalents" refers to the value obtained by dividing the molecular weight of the compound having (meth)acryloyloxy groups by the number of (meth)acryloyloxy groups in one molecule of the compound having (meth)acryloyloxy groups.

[0021] The polyfunctional (meth)acrylic compound (X1) described above preferably has at least one hydroxyl group in one molecule. The presence of the hydroxyl group in the polyfunctional (meth)acrylic compound (X1) results in a sealant for liquid crystal display elements that exhibits superior low liquid crystal contamination properties. Furthermore, when the polyfunctional (meth)acrylic compound (X1) has the hydroxyl group, from the viewpoint of preventing moisture permeability, it is preferable that the number of hydroxyl groups in one molecule of the polyfunctional (meth)acrylic compound (X1) is four or less.

[0022] Examples of the above-mentioned polyfunctional (meth)acrylic compound (X1) include, for example, the compound represented by formula (1) above, ethylene glycol di(meth)acrylate, 1,3-propanediol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,4-cyclohexanedimethanol diacrylate, diethylene glycol di(meth)acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, glycerol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and the like. In particular, the resulting sealant for liquid crystal display elements is superior in high-temperature adhesion, moisture permeability prevention, and low liquid crystal contamination, so the polyfunctional (meth)acrylic compound (X1) is preferably the compound represented by formula (1) above.

[0023] The preferred lower limit for the content of the polyfunctional (meth)acrylic compound (X1) in 100 parts by mass of the curable resin is 5 parts by mass, and the preferred upper limit is 42 parts by mass. When the content of the polyfunctional (meth)acrylic compound (X1) is within this range, the resulting sealant for liquid crystal display elements exhibits superior high-temperature adhesion and moisture permeability prevention. A more preferred lower limit for the content of the polyfunctional (meth)acrylic compound (X1) is 8 parts by mass, and a more preferred upper limit is 25 parts by mass.

[0024] In the liquid crystal display element sealant of this second embodiment, the (meth)acrylic compound comprises a polyfunctional (meth)acrylic compound (X2) having two or more (meth)acryloyloxy groups in one molecule and having a (meth)acryloyloxy group equivalent of 130 or less. By containing the polyfunctional (meth)acrylic compound (X2), the liquid crystal display element sealant of this second embodiment exhibits excellent high-temperature adhesion, moisture permeability prevention, and low liquid crystal contamination.

[0025] The above-mentioned polyfunctional (meth)acrylic compound (X2) has two or more (meth)acryloyloxy groups. In particular, it is preferable that the above-mentioned polyfunctional (meth)acrylic compound (X2) has only two (meth)acryloyloxy groups.

[0026] The above-mentioned polyfunctional (meth)acrylic compound (X2) has an upper limit of 130 (meth)acryloyloxy group equivalents. By having a (meth)acryloyloxy group equivalent of 130 or less in the above-mentioned polyfunctional (meth)acrylic compound (X2), the resulting sealant for liquid crystal display elements will have excellent high-temperature adhesion, moisture permeability prevention, and low liquid crystal contamination properties. The preferred upper limit of the (meth)acryloyloxy group equivalent of the above-mentioned polyfunctional (meth)acrylic compound (X2) is 120. Furthermore, there is no particular preferred lower limit for the (meth)acryloyloxy group equivalent of the above-mentioned polyfunctional (meth)acrylic compound (X2), but the practical lower limit is 92.

[0027] The polyfunctional (meth)acrylic compound (X2) described above preferably has a minimum distance of 1 to 6 atoms between (meth)acryloyloxy groups. Having the minimum distance of atoms between (meth)acryloyloxy groups in the polyfunctional (meth)acrylic compound (X2) within this range results in the liquid crystal display element sealant of this second embodiment exhibiting superior high-temperature adhesion, moisture permeability prevention, and low liquid crystal contamination. More preferably, the minimum distance of atoms between (meth)acryloyloxy groups in the polyfunctional (meth)acrylic compound (X2) is 1 to 3. Furthermore, a more preferable lower limit for the minimum distance of atoms between (meth)acryloyloxy groups in the polyfunctional (meth)acrylic compound (X2) is 2.

[0028] The polyfunctional (meth)acrylic compound (X2) described above preferably has at least one hydroxyl group in one molecule. The presence of the hydroxyl group in the polyfunctional (meth)acrylic compound (X2) results in a sealant for liquid crystal display elements that exhibits superior low liquid crystal contamination properties. Furthermore, when the polyfunctional (meth)acrylic compound (X2) has the hydroxyl group, from the viewpoint of preventing moisture permeability, it is preferable that the number of hydroxyl groups in one molecule of the polyfunctional (meth)acrylic compound (X2) is four or less.

[0029] Examples of the above-mentioned polyfunctional (meth)acrylic compound (X2) include, for example, the compound represented by formula (2) above, ethylene glycol di(meth)acrylate, 1,3-propanediol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,4-cyclohexanedimethanol diacrylate, diethylene glycol di(meth)acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, glycerol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and the like. In particular, the resulting sealant for liquid crystal display elements is superior in high-temperature adhesion, moisture permeability prevention, and low liquid crystal contamination, so the polyfunctional (meth)acrylic compound (X2) is preferably the compound represented by formula (2) above.

[0030] The preferred lower limit for the content of the polyfunctional (meth)acrylic compound (X2) in 100 parts by mass of the curable resin is 5 parts by mass, and the preferred upper limit is 42 parts by mass. When the content of the polyfunctional (meth)acrylic compound (X2) is within this range, the resulting sealant for liquid crystal display elements exhibits superior high-temperature adhesion and moisture permeability prevention. A more preferred lower limit for the content of the polyfunctional (meth)acrylic compound (X2) is 8 parts by mass, and a more preferred upper limit is 25 parts by mass.

[0031] In the sealant for liquid crystal display elements of this embodiment, the curable resin may contain other (meth)acrylic compounds other than the polyfunctional (meth)acrylic compound (X1) and the polyfunctional (meth)acrylic compound (X2).

[0032] As the above-mentioned other (meth)acrylic compounds, monofunctional (meth)acrylic compounds, and other polyfunctional (meth)acrylic compounds other than the above polyfunctional (meth)acrylic compound (X1) and the above polyfunctional (meth)acrylic compound (X2) can be used.

[0033] Examples of the above monofunctional (meth)acrylic compounds include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, and isomiris. Tyl (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, bicyclopentenyl (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-T Examples include trafluoropropyl (meth)acrylate, 1H,1H,5H-octafluoropentyl (meth)acrylate, imide (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, 2-(meth)acryloyloxyethyl 2-hydroxypropyl phthalate, and 2-(meth)acryloyloxyethyl phosphate.

[0034] Examples of the above-mentioned other polyfunctional (meth)acrylic compounds include epoxy (meth)acrylate, (meth)acrylate compounds, urethane (meth)acrylate, etc., and compounds other than the above polyfunctional (meth)acrylic compound (X1) and the above polyfunctional (meth)acrylic compound (X2). Among them, it is preferable that the curable resin contains the epoxy (meth)acrylate as the above-mentioned other polyfunctional (meth)acrylic compound. In the present specification, the above-mentioned "epoxy (meth)acrylate" means a compound obtained by reacting all epoxy groups in an epoxy compound with (meth)acrylic acid.

[0035] Examples of the epoxy (meth)acrylate include those obtained by reacting an epoxy compound having two or more epoxy groups in one molecule with (meth)acrylic acid according to a conventional method in the presence of a basic catalyst.

[0036] Examples of the epoxy compound used as a raw material for the epoxy (meth)acrylate include bisphenol A type epoxy compound, bisphenol F type epoxy compound, bisphenol E type epoxy compound, bisphenol S type epoxy compound, 2,2'-diallylbisphenol A type epoxy compound, hydrogenated bisphenol type epoxy compound, propylene oxide added bisphenol A type epoxy compound, caprolactone modified bisphenol A type epoxy compound, resorcinol type epoxy compound, biphenyl type epoxy compound, sulfide type epoxy compound, diphenyl ether type epoxy compound, dicyclopentadiene type epoxy compound, naphthalene type epoxy compound, phenol novolac type epoxy compound, orthocresol novolac type epoxy compound, dicyclopentadiene novolac type epoxy compound, biphenyl novolac type epoxy compound, naphthalene phenol novolac type epoxy compound, glycidylamine type epoxy compound, alkyl polyol type epoxy compound, rubber modified type epoxy compound, glycidyl ester compound, etc.

[0037] Examples of bifunctional (meth)acrylic acid ester compounds among the above include 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, bisphenol A di(meth)acrylate, ethylene oxide-modified bisphenol A di(meth)acrylate, propylene oxide-modified bisphenol A di(meth)acrylate, bisphenol F di(meth)acrylate, ethylene oxide-modified bisphenol F di(meth)acrylate, propylene oxide-modified bisphenol F di(meth)acrylate, tricyclodecanedimethanol di(meth)acrylate, and ethylene oxide-modified isocyanuric acid di(meth)acrylate.

[0038] Examples of the above-mentioned (meth)acrylic acid ester compounds that have three or more functionalities include ethylene oxide-added isocyanuric acid tri(meth)acrylate, ethylene oxide-added trimethylolpropane tri(meth)acrylate, propylene oxide-added trimethylolpropane tri(meth)acrylate, caprolactone-modified trimethylolpropane tri(meth)acrylate, propylene oxide-added glycerol tri(meth)acrylate, and tris(meth)acryloyloxyethyl phosphate.

[0039] The above-mentioned urethane (meth)acrylate can be obtained, for example, by reacting an isocyanate compound with a (meth)acrylic acid derivative having a hydroxyl group in the presence of a catalytic amount of a tin-based compound.

[0040] Examples of isocyanate compounds that serve as raw materials for the above-mentioned urethane (meth)acrylate include isophorone diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diphenylmethane-4,4'-diisocyanate (MDI), hydrogenated MDI, polymeric MDI, 1,5-naphthalene diisocyanate, norbornane diisocyanate, tollidine diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, lysine diisocyanate, triphenylmethane triisocyanate, tris(isocyanatephenyl)thiophosphate, tetramethylxylylene diisocyanate, and 1,6,11-undecane triisocyanate.

[0041] Furthermore, as the isocyanate compound used as a raw material for the above-mentioned urethane (meth)acrylate, a chain-extended isocyanate compound obtained by the reaction of a polyol with an excess isocyanate compound can also be used. Examples of the above-mentioned polyols include ethylene glycol, propylene glycol, glycerin, sorbitol, trimethylolpropane, carbonate diol, polyether diol, polyester diol, and polycaprolactone diol.

[0042] Examples of (meth)acrylic acid derivatives having a hydroxyl group include hydroxyalkyl (meth)acrylate, mono(meth)acrylate of a dihydric alcohol, mono(meth)acrylate or di(meth)acrylate of a trihydric alcohol, and epoxy (meth)acrylate. Examples of hydroxyalkyl (meth)acrylate include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Examples of dihydric alcohol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and polyethylene glycol. Examples of trihydric alcohol include trimethylolethane, trimethylolpropane, and glycerin. Examples of epoxy (meth)acrylate include bisphenol A type epoxy (meth)acrylate.

[0043] In the sealant for liquid crystal display elements of this embodiment, the preferred lower limit of the total content of the (meth)acrylic compound in 100 parts by mass of the curable resin is 50 parts by mass, and the preferred upper limit is 99 parts by mass. Having the total content of the (meth)acrylic compound within this range results in a sealant for liquid crystal display elements that exhibits superior curability, adhesion, and low liquid crystal contamination. A more preferred lower limit of the total content of the (meth)acrylic compound is 55 parts by mass, and a more preferred upper limit is 95 parts by mass.

[0044] In the sealant for liquid crystal display elements of this embodiment, the curable resin contains an epoxy compound. Examples of the epoxy compound contained in the curable resin include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol E type epoxy compounds, bisphenol S type epoxy compounds, 2,2'-diallylbisphenol A type epoxy compounds, hydrogenated bisphenol type epoxy compounds, propylene oxide-added bisphenol A type epoxy compounds, caprolactone-modified bisphenol A type epoxy compounds, resorcinol type epoxy compounds, biphenyl type epoxy compounds, sulfide type epoxy compounds, diphenyl ether type epoxy compounds, dicyclopentadiene type epoxy compounds, naphthalene type epoxy compounds, phenol novolac type epoxy compounds, orthocresol novolac type epoxy compounds, dicyclopentadiene novolac type epoxy compounds, biphenyl novolac type epoxy compounds, naphthalene phenol novolac type epoxy compounds, glycidylamine type epoxy compounds, alkyl polyol type epoxy compounds, rubber-modified epoxy compounds, glycidyl ester compounds, and the like.

[0045] Partially (meth)acrylic-modified epoxy compounds are also suitably used as the epoxy compounds mentioned above. In this specification, the term "partially (meth)acrylic-modified epoxy compound" refers to a compound obtained by reacting a portion of the epoxy groups of an epoxy compound having two or more epoxy groups with (meth)acrylic acid, and having one or more epoxy groups and one or more (meth)acryloyl groups in one molecule. The partially (meth)acrylic-modified epoxy compound contains (meth)acryloyl groups, but is treated as an epoxy compound rather than a (meth)acrylic compound.

[0046] Examples of commercially available part (meth)acrylic-modified epoxy compounds include UVACURE 1561 and EBECRYL 3605 (both manufactured by Daicel Ornex Co., Ltd.).

[0047] The preferred lower limit for the content of the epoxy compound in 100 parts by mass of the curable resin is 1 part by mass, and the preferred upper limit is 50 parts by mass. When the content of the epoxy compound is within this range, the resulting sealant for liquid crystal display elements exhibits superior curability, adhesion, and low liquid crystal contamination. A more preferred lower limit for the content of the epoxy compound is 5 parts by mass, and a more preferred upper limit is 45 parts by mass.

[0048] The preferred lower limit for the total content of the curable resin in 100 parts by mass of the sealant for liquid crystal display elements in this embodiment is 30 parts by mass, and the preferred upper limit is 90 parts by mass. Having the total content of the curable resin within this range results in a sealant for liquid crystal display elements with superior curability and adhesion.

[0049] The sealing agent for liquid crystal display elements of this embodiment contains a photoradical polymerization initiator. Examples of the above photoradical polymerization initiator include benzophenone compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin ether compounds, thioxanthone compounds, and the like. Specifically, examples of the above photoradical polymerization initiator include 1-hydroxycyclohexylphenyl 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, and 2-methyl-1-(4-methylthiophenyl) Examples include -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-benzoyloxime), 2-(acetoxyimino)-1-(4-(4-(2-hydroxyethoxy)phenylthio)phenyl)propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and 2,4-dimethylthioxanthene-9-one.

[0050] The preferred lower limit of the content of the above-mentioned photoradical polymerization initiator is 0.1 parts by mass and the preferred upper limit is 10 parts by mass per 100 parts by mass of the above-mentioned curable resin. Having the content of the above-mentioned photoradical polymerization initiator within this range results in a sealant for liquid crystal display elements having superior storage stability and photocurability. A more preferred lower limit for the content of the above-mentioned photoradical polymerization initiator is 0.3 parts by mass and a more preferred upper limit is 5 parts by mass.

[0051] The sealant for liquid crystal display elements of this embodiment may contain a thermal radical polymerization initiator. Examples of the thermal radical polymerization initiator include those composed of azo compounds and organic peroxides. Among these, an initiator composed of an azo compound (hereinafter also referred to as "azo initiator") is preferred from the viewpoint of suppressing liquid crystal contamination.

[0052] Examples of the above azo compounds include those having a structure in which multiple units such as polyalkylene oxide or polydimethylsiloxane are bonded via an azo group. Among the polymer azo compounds having a structure in which multiple units such as polyalkylene oxide are bonded via an azo group, those having a polyethylene oxide structure are preferred. Specific examples of the above azo compounds include polycondensates of 4,4'-azobis(4-cyanopentanoic acid) and polyalkylene glycol, and polycondensates of 4,4'-azobis(4-cyanopentanoic acid) and polydimethylsiloxane having terminal amino groups. Examples of the above azo initiators include VPE-0201, VPE-0401, VPE-0601, VPS-0501, VPS-1001, V-65, and V-501 (all manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).

[0053] Examples of the above-mentioned organic peroxides include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, peroxyesters, diacyl peroxides, and peroxydicarbonates.

[0054] The preferred lower limit of the content of the above-mentioned thermal radical polymerization initiator is 0.1 parts by mass and the preferred upper limit is 10 parts by mass per 100 parts by mass of the above-mentioned curable resin. Having the content of the above-mentioned thermal radical polymerization initiator within this range results in a sealant for liquid crystal display elements having superior storage stability and thermosetting properties. A more preferred lower limit for the content of the above-mentioned thermal radical polymerization initiator is 0.3 parts by mass and a more preferred upper limit is 5 parts by mass.

[0055] The sealant for liquid crystal display elements of this embodiment contains a thermosetting agent. Examples of the thermosetting agent include organic acid hydrazides, imidazole derivatives, amine compounds, polyhydric phenolic compounds, and acid anhydrides. Among these, organic acid hydrazides are preferably used.

[0056] Examples of the above-mentioned organic acid hydrazides include sebacate dihydrazide, isophthalic acid dihydrazide, adipic acid dihydrazide, and malonic acid dihydrazide. Commercially available organic acid hydrazides include, for example, organic acid hydrazides manufactured by Otsuka Chemical Co., Ltd., Ajinomoto Fine Techno Co., Ltd., and Mitsubishi Gas Chemical Next Co., Ltd. Examples of organic acid hydrazides manufactured by Otsuka Chemical Co., Ltd. include SDH and ADH. Examples of organic acid hydrazides manufactured by Ajinomoto Fine Techno Co., Ltd. include Amicure VDH, Amicure VDH-J, Amicure UDH, and Amicure UDH-J. Examples of organic acid hydrazides manufactured by Mitsubishi Gas Chemical Next Co., Ltd. include MDH.

[0057] The content of the above-mentioned thermosetting agent is preferably 1 part by mass and preferably 50 parts by mass per 100 parts by mass of the above-mentioned curable resin. By having the content of the above-mentioned thermosetting agent within this range, the resulting sealant for liquid crystal display elements will have superior thermosetting properties while maintaining storage stability and applicability. A more preferable upper limit for the content of the above-mentioned thermosetting agent is 30 parts by mass.

[0058] The sealant for liquid crystal display elements of this embodiment preferably contains a filler for the purpose of improving viscosity, further improving adhesion through stress dispersion effect, improving coefficient of thermal expansion, and further improving moisture permeability.

[0059] The above-mentioned fillers can be inorganic or organic. Examples of inorganic fillers include silica, talc, glass beads, asbestos, gypsum, diatomaceous earth, smectite, 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, and calcium silicate. Examples of organic fillers include polyester microparticles, polyurethane microparticles, vinyl polymer microparticles, and (meth)acrylic polymer microparticles. Furthermore, the above-mentioned organic fillers may have a core-shell structure.

[0060] The preferred lower limit for the content of the filler per 100 parts by mass of the curable resin is 10 parts by mass, and the preferred upper limit is 70 parts by mass. Having the filler content within this range allows for superior effects such as improved adhesion without degrading coatability. A more preferred lower limit for the filler content is 20 parts by mass, and a more preferred upper limit is 60 parts by mass.

[0061] The sealant for liquid crystal display elements of this embodiment preferably further contains a silane coupling agent. The silane coupling agent mainly serves as an adhesive aid for good adhesion between the sealant for liquid crystal display elements and a substrate or the like. Suitable silane coupling agents include, for example, 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-glycidoxypropyltrimethoxysilane.

[0062] The preferred lower limit for the content of the silane coupling agent per 100 parts by mass of the curable resin is 0.1 parts by mass, and the preferred upper limit is 10 parts by mass. Having the silane coupling agent content within this range provides superior effectiveness in suppressing liquid crystal contamination while improving adhesion. A more preferred lower limit for the silane coupling agent content is 0.3 parts by mass, and a more preferred upper limit is 5 parts by mass.

[0063] The sealant for liquid crystal display elements of this embodiment may further contain, if necessary, additives such as light-shielding agents, stress-relieving agents, reactive diluents, thixotropes, spacers, curing accelerators, defoamers, leveling agents, and polymerization inhibitors.

[0064] A method for manufacturing the sealant for liquid crystal display elements of this embodiment includes, for example, a method of mixing a curable resin, a photoradical polymerization initiator, a thermosetting agent, and other components used as needed, such as a filler or silane coupling agent, using a mixer. Examples of such mixers include homodispers, homomixers, universal mixers, planetary mixers, kneaders, and three-roll mixers.

[0065] The sealant for liquid crystal display elements of this embodiment has a preferred lower limit of 110°C and a preferred upper limit of 170°C for the glass transition temperature of the cured product. Having the glass transition temperature of the cured product within this range results in superior high-temperature adhesion and moisture permeability prevention for the sealant for liquid crystal display elements of this embodiment. A more preferred lower limit for the glass transition temperature of the cured product is 120°C, a more preferred upper limit is 155°C, and an even more preferred upper limit is 145°C. In this specification, the glass transition temperature of the cured product can be obtained as the temperature of the maximum value of the loss tangent (tanδ) when measuring dynamic viscoelasticity of a 300 μm thick cured product using a dynamic viscoelasticity measuring device under the following conditions: tensile mode, test piece width 5 mm, grip width 25 mm, heating rate 10°C / min, temperature range -80°C to 200°C, and frequency 10 Hz. For example, a DVA-200 (manufactured by IT Measurement Control Co., Ltd.) can be used as the dynamic viscoelasticity measuring device. Furthermore, the cured material used to measure the glass transition temperature is, for example, a sealant for liquid crystal display elements, measured at a wavelength of 365 nm and an illuminance of 100 mW / cm². ２ This can be obtained by irradiating with light for 30 seconds and then heating at 120°C for 60 minutes, or by other methods. The wavelength of light irradiated onto the sealant for liquid crystal display elements to obtain the above cured product is appropriately selected according to the type of photoradical polymerization initiator.

[0066] Furthermore, by incorporating conductive fine particles into the sealant for liquid crystal display elements of this embodiment, a conductive material can be manufactured. As the conductive fine particles, metal balls, resin fine particles with a conductive metal layer formed on their surface, etc., can be used. Among these, resin fine particles with a conductive metal layer formed on their surface are preferred because, due to the excellent elasticity of the resin fine particles, conductive connections can be made without damaging transparent substrates, etc.

[0067] The sealant for liquid crystal display elements of this embodiment is suitably used in the manufacture of liquid crystal display elements. The liquid crystal display element typically includes a cured product of the sealant for liquid crystal display elements of this embodiment. A liquid crystal display element with a narrow bezel design is preferred. Specifically, it is preferable that the width of the frame portion surrounding the liquid crystal display area is 2 mm or less.

[0068] As a method for manufacturing the above-mentioned liquid crystal display element, the liquid crystal drop method is preferably used, and specifically, for example, a method having the following steps can be mentioned. First, a frame-shaped sealing pattern is formed by applying the liquid crystal display element sealant of this embodiment to one of two transparent substrates having electrodes and alignment films such as ITO thin films by screen printing, dispenser coating, etc. Next, minute droplets of liquid crystal are dropped onto the entire surface within the frame of the sealing pattern, and the other transparent substrate is placed on top under vacuum. After that, a liquid crystal display element can be obtained by performing a step of pre-curing the sealant by irradiating the sealing pattern portion with light such as ultraviolet light (photocuring step), and a step of fully curing the pre-cured sealant by heating it (thermocuring step). When manufacturing the above-mentioned liquid crystal display element, the coating width of the liquid crystal display element sealant of this embodiment is preferably 1 mm or less.

[0069] Furthermore, the use of a curable resin composition containing a curable resin, a photoradical polymerization initiator, and a thermosetting agent, wherein the curable resin includes a (meth)acrylic compound without epoxy groups and an epoxy compound, the (meth)acrylic compound having two or more (meth)acryloyloxy groups in one molecule, and the number of atoms constituting the shortest covalent bond connecting one (meth)acryloyloxy group to the other (meth)acryloyloxy group between the two (meth)acryloyloxy groups furthest apart, is between 1 and 6, as a sealant for liquid crystal display elements is also one embodiment of the present invention. In the curable resin composition in this embodiment, the components and physical properties are the same as those of the sealant for liquid crystal display elements in Embodiment 1.

[0070] Furthermore, the use of a curable resin composition containing a curable resin, a photoradical polymerization initiator, and a thermosetting agent, wherein the curable resin contains a (meth)acrylic compound without epoxy groups and an epoxy compound, and the (meth)acrylic compound has two or more (meth)acryloyloxy groups in one molecule and a polyfunctional (meth)acrylic compound (X2) with a (meth)acryloyloxy group equivalent of 130 or less, as a sealant for liquid crystal display elements is also one embodiment of the present invention. In the curable resin composition in this embodiment, the components and physical properties are the same as those of the sealant for liquid crystal display elements in Embodiment 2.

[0071] According to the present invention, it is possible to provide a sealant for liquid crystal display elements that is excellent in high-temperature adhesion, moisture permeability prevention, and low liquid crystal contamination. Furthermore, according to the present invention, it is possible to provide a method for using a curable resin composition as a sealant for liquid crystal display elements.

[0072] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0073] (Examples 1-9, Comparative Examples 1-4) Following the mixing ratios listed in Tables 1 and 2, each material was stirred in a planetary agitator and then uniformly mixed using a ceramic three-roll roller to obtain the liquid crystal display element sealants of Examples 1-9 and Comparative Examples 1-4. The Awatori Rentaro (manufactured by Shinky Co., Ltd.) was used as the planetary agitator.

[0074] The materials used in the examples and comparative examples are as follows: <Curable resin> ((meth)acrylic compound) ・2-hydroxy-1,3-dimethacryloxypropane: NK Ester 701 (manufactured by Shin Nakamura Chemical Industry Co., Ltd.), number of atoms in the shortest distance between methacryloyloxy groups is 3, methacryloyloxy group equivalent is 114, hydroxyl group present ・Neopentyl glycol dimethacrylate: NK Ester NPG (manufactured by Shin Nakamura Chemical Industry Co., Ltd.), number of atoms in the shortest distance between methacryloyloxy groups is 3, methacryloyloxy group equivalent is 120, hydroxyl group absent ・1,6-Hexanediol dimethacrylate: Manufactured by Tokyo Chemical Industry Co., Ltd., shortest distance between methacryloyloxy groups: 6 atoms, methacryloyloxy group equivalent: 127, no hydroxyl groups; Trimethylolpropane triacrylate: Manufactured by Tokyo Chemical Industry Co., Ltd., shortest distance between acryloyloxy groups: 3 atoms, acryloyloxy group equivalent: 99, no hydroxyl groups; Tricyclodecanedimethanol diacrylate: IRR214K (manufactured by Daicel Ornex Co., Ltd.), shortest distance between acryloyloxy groups: 7 atoms, acryloyloxy group equivalent: 152, no hydroxyl groups; Resorcinol-type epoxy acrylate: RGDA (manufactured by Kyoeisha Chemical Co., Ltd.), shortest distance between acryloyloxy groups: 11 atoms, acryloyloxy group equivalent: 183, hydroxyl groups present; Caprolactone-modified bisphenol A type epoxy acrylate: EBECRY L3708 (manufactured by Daicel Ornex), shortest distance between acryloyloxy groups: 61 atoms, acryloyloxy group equivalent: 663, hydroxyl group present; Ethylene oxide-added isocyanuric acid (di / tri) acrylate: Aronics M-315 (manufactured by Toagosei Co., Ltd.), shortest distance between acryloyloxy groups: 7 atoms, acryloyloxy group equivalent: 141 or 185, partially hydroxyl group present; Bisphenol A type epoxy acrylate: EBECRY L3700 (manufactured by Daicel Ornex), shortest distance between acryloyloxy groups: 17 atoms, acryloyloxy group equivalent: 242, hydroxyl group present; Bisphenol A type epoxy methacrylate: Epoxy ester 3000MK (manufactured by Kyoeisha Chemical Co., Ltd.), shortest distance between methacryloyloxy groups: 17 atoms, methacryloyloxy group equivalent: 256, hydroxyl group present (Epoxy Compounds) ・Partially acrylic-modified bisphenol A type epoxy compound: UVACURE 1561 (manufactured by Daicel Ornex) <Photoradical polymerization initiator> ・2-(acetoxyimino)-1-(4-(4-(2-hydroxyethoxy)phenylthio)phenyl)propan-1-one: ADEKA Arcules NCI-930 (manufactured by ADEKA) <Thermosetting agent> ・Dihydrazide malonate: MDH (manufactured by Mitsubishi Gas Chemical Next) <Filler> ・Silica: Sunseal SP-07M (manufactured by Tokuyama) <Silane coupling agent> ・3-Glycidoxypropyltrimethoxysilane: Sylace S510 (manufactured by Chisso Corporation)

[0075] (Glass transition temperature of the cured product) The obtained sealant for liquid crystal display elements was measured using a metal halide lamp at a wavelength of 365 nm and an illuminance of 100 mW / cm². ２ A cured material with a thickness of 300 μm was obtained by irradiating the material with light for 30 seconds and then heating it at 120°C for 60 minutes. The dynamic viscoelasticity of the obtained cured material was measured using a dynamic viscoelasticity measuring device (DVA-200, manufactured by IT Measurement Control Co., Ltd.) under the following conditions: tensile mode, specimen width 5 mm, grip width 25 mm, heating rate 10°C / min, temperature range -80°C to 200°C, and frequency 10 Hz, and the glass transition temperature was determined. The results are shown in Tables 1 and 2.

[0076] <Evaluation> The following evaluations were performed on the liquid crystal display element sealants obtained in the examples and comparative examples. The results are shown in Tables 1 and 2.

[0077] (High-temperature adhesion) A substrate with an alignment film was fabricated by spin-coating a polyimide resin onto a glass substrate with an ITO thin film, pre-baking it at 80°C, and then firing it at 230°C. SE7492 (manufactured by Nissan Chemical Corporation) was used as the polyimide resin. Two substrates with alignment films were prepared in this manner, and the sealant for liquid crystal display elements obtained was dotted onto one of the substrates so that the diameter when the substrates were bonded together would be 3 mm. The substrate with the dotted sealant and the other substrate were bonded together in a cross shape via the sealant. After that, a metal halide lamp was used at a wavelength of 365 nm and an illuminance of 100 mW / cm. ２ After irradiating with light for 30 seconds, the specimens were heated at 120°C for 60 minutes to obtain adhesive test pieces. A total of 12 adhesive test pieces were prepared in the same manner. The obtained adhesive test pieces were left to stand for 24 hours in an environment of 121°C, 100% RH, and 2 atm, and the presence or absence of peeling of the cured sealant was checked visually. The high-temperature adhesion was evaluated according to the following criteria: ○: No peeling in 75% (9 pieces) or more of the adhesive test pieces △: No peeling in 25% (3 pieces) or more but less than 75% (9 pieces) of the adhesive test pieces ×: Less than 25% (3 pieces) of the adhesive test pieces did not peel

[0078] (Moisture-proof properties) The obtained sealant for liquid crystal display elements was applied to a smooth release film using a coater to a thickness of 200-300 μm. Then, a metal halide lamp was used at a wavelength of 365 nm and an illuminance of 100 mW / cm. ２ After irradiating the liquid crystal display element sealant with light for 30 seconds, it was heated at 120°C for 60 minutes to cure it, and a film for measuring moisture permeability was obtained. A cup for measuring moisture permeability was prepared in accordance with the method for testing moisture permeability of moisture-proof packaging materials (cup method) of JIS Z 0208:1976, the obtained film for measuring moisture permeability was attached to the cup, and the cup was placed in a constant temperature and humidity oven at 85°C and 85% RH to measure the moisture permeability, and the moisture permeability was evaluated according to the following criteria. ◎: Moisture permeability of 50 g / m ２ - If less than 24 hours: ○: Moisture permeability of 50 g / m ２ ・55g / m for 24hr or more ２ - If less than 24 hours: ×: Moisture permeability is 55 g / m ２ - If it was 24 hours or more

[0079] (Low Liquid Crystal Contamination) 0.5 g of positive-type liquid crystal (JNC Corporation, "JC-7129XX") was placed in a sample bottle, 0.1 g of the obtained liquid crystal display element sealant was added and shaken, then heated at 120°C for 60 minutes and returned to room temperature (25°C). The obtained liquid crystal display element sealant was applied with a dispenser to the alignment film (Nissan Chemical Corporation, "RB-089") of a glass substrate having a transparent electrode and an alignment-treated film, drawing a square frame. Subsequently, minute droplets of liquid crystal taken from the sample bottle were dropped onto the entire area within the sealant frame on the substrate, and another glass substrate was placed on top in a vacuum. The vacuum was released, and a metal halide lamp was used at a wavelength of 365 nm and an illuminance of 100 mW / cm. ２After irradiating with light for 30 seconds, the sealant was cured by heating at 120°C for 60 minutes to obtain a liquid crystal display element. For the obtained liquid crystal display element, a liquid crystal property evaluation system (Toyo Technica Co., Ltd., "Model 6254") was used to calculate the voltage retention rate of the liquid crystal by applying an AC voltage of 10V, 0.1Hz at 25°C and measuring the retention voltage after 1 second. The low liquid crystal contamination performance was evaluated according to the following criteria: ◎: Voltage retention rate of 95% or more ○: Voltage retention rate of 90% or more but less than 95% △: Voltage retention rate of 80% or more but less than 90% ×: Voltage retention rate of less than 80%

[0080]

[0081]

[0082] According to the present invention, it is possible to provide a sealant for liquid crystal display elements that is excellent in high-temperature adhesion, moisture permeability prevention, and low liquid crystal contamination. Furthermore, according to the present invention, it is possible to provide a method for using a curable resin composition as a sealant for liquid crystal display elements.

Claims

1. A sealant for liquid crystal display elements, comprising a curable resin, a photoradical polymerization initiator, and a thermosetting agent, wherein the curable resin comprises a (meth)acrylic compound without epoxy groups and an epoxy compound, and the (meth)acrylic compound comprises a polyfunctional (meth)acrylic compound (X1) having two or more (meth)acryloyloxy groups in one molecule, and the number of atoms constituting the shortest covalent bond connecting one (meth)acryloyloxy group to the other (meth)acryloyloxy group between the two (meth)acryloyloxy groups that are furthest apart is 1 to 6.

2. The sealant for liquid crystal display elements according to claim 1, wherein the polyfunctional (meth)acrylic compound (X1) has 1 or more atoms that constitute the shortest covalent bond connecting one (meth)acryloyloxy group to the other (meth)acryloyloxy group between two (meth)acryloyloxy groups that are furthest apart.

3. The sealant for liquid crystal display elements according to claim 1 or 2, wherein the polyfunctional (meth)acrylic compound (X1) has at least one hydroxyl group in one molecule.

4. The sealant for liquid crystal display elements according to claim 3, wherein the polyfunctional (meth)acrylic compound (X1) is a compound represented by the following formula (1). In formula (1), R １ and R ２ Each of these is independently a hydrogen atom or a methyl group, and R ３ ~R ８ Each of these is independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a hydroxyl group, and R ３ ~R ８ At least one of them is a hydroxyl group.

5. The sealing agent for liquid crystal display elements according to any one of claims 1 to 4, wherein the content of the polyfunctional (meth)acrylic compound (X1) in 100 parts by mass of the curable resin is 5 parts by mass or more and 42 parts by mass or less.

6. A sealant for liquid crystal display elements, comprising a curable resin, a photoradical polymerization initiator, and a thermosetting agent, wherein the curable resin comprises a (meth)acrylic compound without epoxy groups and an epoxy compound, and the (meth)acrylic compound comprises a polyfunctional (meth)acrylic compound (X2) having two or more (meth)acryloyloxy groups in one molecule and having an (meth)acryloyloxy group equivalent of 130 or less.

7. The sealant for liquid crystal display elements according to claim 6, wherein the polyfunctional (meth)acrylic compound (X2) has at least one hydroxyl group in one molecule.

8. The sealant for liquid crystal display elements according to claim 7, wherein the polyfunctional (meth)acrylic compound (X2) is a compound represented by the following formula (2). In formula (2), R ９ and R １０ are each independently a hydrogen atom or a methyl group, and R １１ to R １６ are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a hydroxyl group, and at least one of R １１ to R １６ is a hydroxyl group.

9. The sealing agent for liquid crystal display elements according to any one of claims 6 to 8, wherein the content of the polyfunctional (meth)acrylic compound (X2) in 100 parts by mass of the curable resin is 5 parts by mass or more and 42 parts by mass or less.

10. A sealant for liquid crystal display elements according to any one of claims 1 to 8, wherein the glass transition temperature of the cured product is 110°C or higher and 170°C or lower.

11. Use of a curable resin composition as a sealant for liquid crystal display elements, characterized in that it contains a curable resin, a photoradical polymerization initiator, and a thermosetting agent, wherein the curable resin contains a (meth)acrylic compound that does not have an epoxy group and an epoxy compound, and the (meth)acrylic compound contains a polyfunctional (meth)acrylic compound (X1) having two or more (meth)acryloyloxy groups in one molecule, and the number of atoms constituting the shortest covalent bond connecting one (meth)acryloyloxy group to the other (meth)acryloyloxy group between the two (meth)acryloyloxy groups that are furthest apart is 1 to 6.

12. Use of a curable resin composition as a sealant for liquid crystal display elements, wherein the curable resin contains a curable resin, a photoradical polymerization initiator, and a thermosetting agent, the curable resin comprises a (meth)acrylic compound that does not have epoxy groups and an epoxy compound, and the (meth)acrylic compound contains a polyfunctional (meth)acrylic compound (X2) having two or more (meth)acryloyloxy groups in one molecule and having an (meth)acryloyloxy group equivalent of 130 or less.

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