Resin composition, liquid crystal sealant, and liquid crystal display panel using the same

Abstract

The present invention addresses the problem of providing a resin composition which exhibits high adhesive strength to a substrate or an alignment film of a liquid crystal display panel despite exhibiting low moisture permeability when cured. A resin composition able to solve the foregoing problem contains: a thermosetting compound (A); a latent thermal curing agent (B) having a melting point of 110°C or less; a photocurable compound (C) having an ethylenically unsaturated double bond in the molecule; and a photopolymerization initiator (D). The thermosetting compound (A) includes a rubber-modified epoxy compound (a) having an epoxy group, an acrylonitrile-butadiene rubber structure and a bisphenol A type structure in a molecule.= The resin composition has a moisture permeation amount of less than 100 g / m2 under prescribed conditions.

Description

[Technical Field]

[0001] The present invention relates to a resin composition, a liquid crystal sealant, and a liquid crystal display panel using the same. [Background technology]

[0002] In recent years, liquid crystal display panels have been widely used as devices for various types of displays. A typical liquid crystal display panel consists of a pair of substrates with electrodes on their surfaces, a pair of alignment films placed between them, a liquid crystal layer sandwiched between the alignment films, and a frame-shaped sealing material for sealing the liquid crystal layer. The sealing material is generally placed in the bezel area outside the effective display area of ​​the liquid crystal display panel.

[0003] The above-mentioned encapsulant requires high adhesive strength to the substrate in order to prevent leakage of liquid crystal material from the liquid crystal layer. Therefore, the adhesive strength is increased by chemically bonding the functional groups on the substrate surface (e.g., OH groups) with the functional groups on the encapsulant surface (e.g., epoxy groups) (see, for example, Patent Document 1). On the other hand, the encapsulant also requires low moisture permeability to prevent external moisture from passing through to the liquid crystal side. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2005-018022 [Overview of the project] [Problems that the invention aims to solve]

[0005] In recent years, there has been a demand to narrow the bezel width of liquid crystal display panels. Narrowing the bezel width significantly reduces the distance from the edge of the alignment film to the edge of the liquid crystal display panel, allowing the alignment film to be positioned within the bezel (the area where the encapsulant is formed). However, many alignment films are hydrophobic. Therefore, it is difficult to create a chemical bond between the encapsulant and the alignment film, and with conventional materials, it has been difficult to obtain sufficient adhesive strength. In particular, reducing the moisture permeability of the encapsulant tends to lower the adhesive strength between the substrate or alignment film and the encapsulant. In short, forming an encapsulant that combines high adhesive strength with the substrate or alignment film, as well as low moisture permeability, has been extremely difficult.

[0006] This invention has been made in view of the above problems, and aims to provide a resin composition and liquid crystal sealant that exhibit high adhesive strength to the substrate and alignment film of a liquid crystal display panel despite having low moisture permeability when cured, as well as a liquid crystal display panel using the same. [Means for solving the problem]

[0007] The present invention relates to a resin composition comprising a thermosetting compound (A), a latent thermosetting agent (B) having a melting point of 110°C or lower, a photocurable compound (C) having an ethylenically unsaturated double bond in its molecule, and a photopolymerization initiator (D), wherein the thermosetting compound (A) comprises a rubber-modified epoxy compound (a) having an epoxy group, an acrylonitrile-butadiene rubber structure, and a bisphenol A type structure in one molecule, and the resin composition is applied to a thickness of 100 μm and exposed to light with a wavelength of 370 nm to 450 nm at an integrated light intensity of 300 mJ / cm². 2 After irradiating the film in this manner, it was heated at 120°C for 1 hour to cure it. The moisture permeability measured in accordance with JIS Z0208:1976 at 60°C and 90% Rh for 24 hours was 100 g / m². 2 The present invention provides a resin composition that is less than [amount missing].

[0008] The present invention further provides a liquid crystal sealant comprising the above-mentioned resin composition.

[0009] The present invention further provides a liquid crystal display panel comprising a pair of substrates, an alignment film sandwiched between the pair of substrates, a liquid crystal layer sandwiched between the pair of alignment films, and a sealing material for sealing the liquid crystal layer, wherein the sealing material is a cured product of the liquid crystal sealant. [Effects of the Invention]

[0010] The resin composition of the present invention exhibits high adhesive strength to the substrate and alignment film of a liquid crystal display panel, despite having low moisture permeability when cured. [Modes for carrying out the invention]

[0011] In this specification, a numerical range represented by "~" means a range that includes the numbers written before and after "~" as the lower and upper limits, respectively.

[0012] 1. Resin composition (liquid crystal sealant) The resin composition of the present invention is a composition that can be cured by heat and light, and can be used, for example, as a liquid crystal sealant. The following description will use the application of the resin composition to a liquid crystal sealant for forming a encapsulant for a liquid crystal display panel as an example, but the use of the resin composition is not limited to liquid crystal sealants.

[0013] The resin composition of the present invention comprises at least a thermosetting compound (A) containing a specific rubber-modified epoxy compound (a), a latent thermosetting agent (B) having a melting point of 110°C or lower, a photocurable compound (C) having an ethylenically unsaturated double bond in its molecule, and a photopolymerization initiator (D). The resin composition may further contain, as needed, an inorganic filler (E), a silane coupling agent (F), core-shell type fine particles (G), etc. Furthermore, as described later, the moisture permeability when the resin composition is cured under predetermined conditions is below a certain value.

[0014] As described above, the adhesive strength of the cured liquid crystal sealant (also referred to as "sealant" in this specification) with the substrate or alignment film, and its low moisture permeability, are in a trade-off relationship, and it has been difficult to achieve both.

[0015] In contrast, although the moisture permeability of the resin composition of the present invention after curing is not more than a certain value, the adhesive strength with substrates, alignment films, etc. of liquid crystal display panels is high. The reason for this is not clear, but it is considered as follows. In the resin composition of the present invention, the thermosetting compound (A) contains, in one molecule, a rubber-modified epoxy compound (a) having an epoxy group, an acrylonitrile-butadiene rubber structure, and a bisphenol A type structure. The rubber-modified epoxy compound (a) has relatively flexible properties due to its acrylonitrile-butadiene rubber structure. Therefore, the sealing material obtained by curing the resin composition easily follows the deformation of the substrate or the like, and peeling at the interface between the substrate, alignment film and the sealing material hardly occurs. Furthermore, when an external force is applied to the liquid crystal display panel, the stress can also be relaxed by the sealing material. Therefore, the adhesive strength between the sealing material and the substrate or alignment film becomes very high.

[0016] On the other hand, the bisphenol A skeleton of the rubber-modified epoxy compound (a) easily blocks moisture entering from the outside into the sealing material. Therefore, the moisture permeability described below can be realized. That is, according to the resin composition of the present invention, a sealing material having a high adhesive strength with substrates and alignment films of liquid crystal display panels and low moisture permeability can be obtained. Hereinafter, each component in the resin composition of the present invention will be described in detail.

[0017] 1-1. Thermosetting compound (A) The thermosetting compound (A) may be any compound that cures by heating, and at least a part or all of it is the above rubber-modified epoxy compound (a).

[0018] The above rubber-modified epoxy compound (a) may be any compound having at least one or more epoxy groups, acrylonitrile-butadiene rubber structures, and bisphenol A type structures in one molecule, and its structure is not particularly limited. The number of epoxy groups possessed by the rubber-modified epoxy compound (a) may be one, but from the viewpoint of thermosetting, two or more are preferable.

[0019] Examples of the rubber-modified epoxy compound (a) include compounds in which an epoxy group is bonded via a bisphenol A-type structure to the terminal of a chain-like acrylonitrile-butadiene rubber structure. The rubber-modified epoxy compound (a) can be, for example, a compound synthesized by the following method. First, prepare an acrylonitrile-butadiene rubber having a desired molecular weight, and modify the terminal of the acrylonitrile-butadiene rubber with a compound having a functional group capable of reacting with an epoxy group by a known method. Examples of groups capable of reacting with an epoxy group include a carboxy group, an amino group, a hydroxy group, etc., and among these, a carboxy group is preferred from the viewpoints of reactivity, etc. On the other hand, prepare a polyfunctional epoxy compound having a bisphenol A-type structure. The polyfunctional epoxy compound can be synthesized, for example, by the reaction of bisphenol A and epichlorohydrin. Then, by reacting the functional group (for example, carboxy group) of the above-mentioned modified acrylonitrile-butadiene rubber with the epoxy group of the polyfunctional epoxy compound, a rubber-modified epoxy compound (a) having epoxy groups at both terminals can be obtained. The structure of the rubber-modified epoxy compound can be specified, for example, by thermal decomposition GC / MS or NMR after fractionation by gel permeation chromatography (GPC). Note that the rubber-modified epoxy compound may be a commercially available product. Examples of commercially available products include TSR-601 and TSR-060 (both manufactured by DIC Corporation).

[0020] The epoxy equivalent of the above rubber-modified epoxy compound (a) is preferably 300 or more and 1000 or less, and more preferably 400 or more and 600 or less. When the epoxy equivalent is 300 or more, the adhesive strength between the obtained sealing material and the substrate or alignment film of the liquid crystal display panel is more likely to increase further. On the other hand, when the epoxy equivalent of the rubber-modified epoxy compound (a) is 1000 or less, it does not become overly flexible, and the obtained sealing material is likely to stably seal the liquid crystal. Also, it prevents a significant deterioration in the moisture permeation amount. The above epoxy equivalent is a value obtained by dividing the molecular weight of the rubber-modified epoxy compound (a) by the number of epoxy groups possessed by the molecule, and the average molecular weight can be specified by gel permeation chromatography (GPC).

[0021] Furthermore, the molecular weight of the rubber-modified epoxy compound (a) is preferably 2000 or less, and more preferably 600 to 1200. When the average molecular weight of the rubber-modified epoxy compound (a) is 2000 or less, the coatability of the resin composition is further enhanced, and it becomes easier to form a sealant with a desired width. Also, from the viewpoint of making it easier to adjust the low moisture permeability, which will be described later, to a more desired range, it is preferable that the molecular weight of the rubber-modified epoxy compound (a) is 2000 or less.

[0022] The amount of the above-mentioned rubber-modified epoxy compound (a) is preferably 10 parts by mass or more and 25 parts by mass or less, and more preferably 14 parts by mass or more and 20 parts by mass or less, relative to 100 parts by mass of the total amount of the thermosetting compound (A) and the photocurable compound (C) described later. If the amount of the rubber-modified epoxy compound (a) is 10 parts by mass or more relative to the total amount of the thermosetting compound (A) and the photocurable compound (C), the moisture permeability of the sealant tends to be further reduced. On the other hand, if the amount of the above-mentioned rubber-modified epoxy compound (a) is 25 parts by mass or less, the amount of the photocurable compound (C) becomes relatively larger, and the photocurability of the resin composition tends to be further improved.

[0023] Thermosetting compound (A) may contain other thermosetting compounds in addition to the rubber-modified epoxy compound (a) described above. Examples of other thermosetting compounds include epoxy compounds having epoxy groups. However, in this specification, even if a compound has an epoxy group, if it has an ethylenically unsaturated double bond, it is classified as a photocurable compound (C) described later and is not included in thermosetting compound (A). Thermosetting compound (A) may contain only one epoxy compound or two or more.

[0024] The epoxy compound may contain only one epoxy group or two or more epoxy groups in its molecule. Examples of epoxy compounds include aromatic epoxy compounds, aliphatic epoxy compounds, and alicyclic epoxy compounds, but aromatic epoxy compounds are preferred from the viewpoint of further reducing the moisture permeability of the resulting sealant to the range described later.

[0025] Examples of aromatic epoxy compounds include aromatic diols such as bisphenol A, bisphenol S, bisphenol F, and bisphenol AD, and aromatic polyvalent glycidyl ether compounds obtained by reacting these aromatic diols, modified with ethylene glycol, propylene glycol, alkylene glycol, etc., with epichlorohydrin; novolac-type polyvalent glycidyl ether compounds obtained by reacting polyphenols, such as novolac resins derived from phenol or cresol and formaldehyde, polyalkenylphenols and their copolymers, with epichlorohydrin; and glycidyl ether compounds of xylylenephenol resins.

[0026] Among these, cresol novolac type epoxy compounds, phenol novolac type epoxy compounds, bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, triphenolmethane type epoxy compounds, triphenolethane type epoxy compounds, trisphenol type epoxy compounds, dicyclopentadiene type epoxy compounds, diphenyl ether type epoxy compounds, or biphenyl type epoxy compounds are preferred.

[0027] Furthermore, the epoxy compound may be in liquid or solid form. From the viewpoint of reducing the moisture permeability of the resulting sealant, a solid epoxy compound is preferred. The softening point of the solid epoxy compound is preferably between 40°C and 150°C. The softening point can be measured by the ring-and-ball method specified in JIS K7234.

[0028] Furthermore, the weight-average molecular weight of the epoxy compound is preferably 300 to 10,000, and more preferably 500 to 5,000. The weight-average molecular weight of the epoxy compound is measured in polystyrene equivalent by gel permeation chromatography (GPC).

[0029] Here, the total amount of thermosetting compound (A) in the resin composition (the total amount of the rubber-modified epoxy compound (a) and other thermosetting compounds) is preferably 30% by mass or more and 70% by mass or less, and more preferably 40% by mass or more and 60% by mass or less, relative to the total amount of the resin composition. If the amount of thermosetting compound (A) is 40% by mass or more, the moisture permeability of the sealant tends to be lower. On the other hand, if the amount of thermosetting compound (A) is 60% by mass or less, the amount of photocurable compound (C), described later, becomes relatively larger, and the photocurability of the resin composition tends to be good.

[0030] 1-2. Latent thermosetting agent (B) The latent thermosetting agent (B) is a compound that does not cure thermosetting compounds (A) under normal storage conditions (room temperature, visible light, etc.), but cures these compounds when heat is applied, and is not particularly limited as long as its melting point is 110°C or lower. The melting point of the latent thermosetting agent (B) is more preferably between 70°C and 100°C. When curing the resin composition, it is necessary to raise the temperature to near the melting point in order for the latent thermosetting agent (B) to act. However, if the temperature of the resin composition is raised to a high temperature, the uncured photocurable compound (C) is more likely to dissolve into the liquid crystal. In contrast, if the melting point of the latent thermosetting agent (B) is 110°C or lower, such dissolution is less likely to occur. The resin composition may contain only one type of latent thermosetting agent (B), or it may contain two or more types.

[0031] The latent thermosetting agent (B) is appropriately selected in accordance with the thermosetting compound (A) described above, but a curing agent capable of opening the epoxy group of the rubber-modified epoxy compound (a) described above and curing it (hereinafter also referred to as "epoxy curing agent") is preferred.

[0032] Examples of epoxy curing agents (latent thermosetting agents (B)) include dihydrazide-based latent thermosetting agents, amine adduct-based latent thermosetting agents, polyamine-based latent thermosetting agents, dicyandiamide-based latent thermosetting agents, imidazole-based latent thermosetting agents, etc. The resin composition may contain only one of these, or two or more.

[0033] Examples of dihydrazide-based heat-latent curing agents with a melting point of 110°C or lower include 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin, 7,11-octadecadiene-1,18-dicarbohydrazide, dodecandioic acid dihydrazide, and sebacate dihydrazide.

[0034] Amine adduct-based thermal latent curing agents are thermal latent curing agents consisting of an addition compound obtained by reacting a catalytically active amine compound with any compound. Examples of commercially available amine adduct-based thermal latent curing agents include Amicure PN-40, Amicure PN-23, Amicure PN-31, Amicure PN-H, and Amicure MY-24 (all manufactured by Ajinomoto Fine Techno Co., Ltd.).

[0035] Polyamine-based thermal latent curing agents are thermal latent curing agents having a polymer structure obtained by reacting an amine with an epoxy resin. Examples of commercially available products include ADEKA Hardener EH4339S, ADEKA Hardener EH4357S, and ADEKA Hardener EH5030S (all manufactured by ADEKA Corporation).

[0036] Examples of dicyandiamide-based thermal latent curing agents include dicyandiamide and the like.

[0037] Examples of imidazole-based heat-latent curing agents include ADEKA Hardener EH-4344S and EH-5011S (both manufactured by ADEKA), 2,4-diamino-6-[2'-ethylimidazolyl-(1')]-ethyltriazine, and 2-phenylimidazole.

[0038] Among the above, imidazole-based thermal latent curing agents, amine adduct-based thermal latent curing agents, and polyamine-based thermal latent curing agents are preferred from the viewpoint of reactivity, etc.

[0039] The amount of latent thermosetting agent (B) is preferably 2% by mass or more and 15% by mass or less, more preferably 3% by mass or more and 14% by mass or less, and even more preferably 3% by mass or more and 12% by mass or less, relative to the total amount of the resin composition.

[0040] 1-3. Photocurable compound (C) The photocurable compound (C) is not particularly limited as long as it has at least one ethylenically unsaturated double bond in its molecule and is polymerizable by light. Examples of photocurable compounds include (meth)acrylic compounds that contain a (meth)acryloyl group but do not contain an epoxy group, and (meth)acrylic-modified epoxy compounds that have both a (meth)acryloyl group and an epoxy group in their molecule.

[0041] (Meth)acrylic compounds are any compounds that contain one or more (meth)acryloyl groups in one molecule and do not contain epoxy groups, and the number of (meth)acryloyl groups may be one or two or more. Examples of monofunctional (meth)acrylic compounds containing one (meth)acryloyl group in one molecule include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, isobornyl (meth)acrylic, dicyclopentanyl (meth)acrylic, and 2-hydroxyethyl (meth)acrylate.

[0042] Examples of polyfunctional (meth)acrylic compounds having two or more (meth)acryloyl groups in one molecule include: di(meth)acrylates derived from polyethylene glycol, propylene glycol, polypropylene glycol, etc.; di(meth)acrylates derived from tris(2-hydroxyethyl) isocyanurate; di(meth)acrylates derived from diols obtained by adding 4 or more moles of ethylene oxide or propylene oxide to 1 mole of neopentyl glycol; di(meth)acrylates (bisphenol A or F type epoxy(meth)acrylates) derived from diols obtained by adding 2 moles of ethylene oxide or propylene oxide to 1 mole of bisphenol A or bisphenol F; di or tri(meth)acrylates derived from polyols obtained by adding 2 or 3 moles of ethylene oxide or propylene oxide to 1 mole of trimethylolpropane; di(meth)acrylates derived from diols obtained by adding 4 or more moles of ethylene oxide or propylene oxide to 1 mole of bisphenol A; tris(2-hydroxyethyl) isocyanurate Ethyl) isocyanurate tri(meth)acrylate; trimethylolpropane tri(meth)acrylate or its oligomer; pentaerythritol tri(meth)acrylate or its oligomer; poly(meth)acrylate of dipentaerythritol; tris(acryloxyethyl) isocyanurate; caprolactone-modified tris(acryloxyethyl) isocyanurate; caprolactone-modified tris(methacryloxyethyl) isocyanurate; alkyl-modified poly(meth)acrylate of dipentaerythritol; capro Poly(meth)acrylate of lactone-modified dipentaerythritol; neopentyl glycol di(meth)acrylate of hydroxypivalate; neopentyl glycol di(meth)acrylate of caprolactone-modified hydroxypivalate; ethylene oxide-modified phosphoric acid (meth)acrylate; ethylene oxide-modified alkylated phosphoric acid (meth)acrylate; di(meth)acrylate obtained by adding 2 moles of succinic acid or phthalic acid and hydroxypropyl (meth)acrylate to 1 mole of bisphenol A or bisphenol F;This also includes oligo(meth)acrylates of neopentyl glycol, trimethylolpropane, and pentaerythritol. Among these, di(meth)acrylates (bisphenol A or F-type epoxy(meth)acrylates) derived from diols obtained by adding 2 moles of ethylene oxide or propylene oxide to 1 mole of bisphenol A or bisphenol F are preferred.

[0043] However, as the amount of monofunctional (meth)acrylic compound increases, the moisture permeability of the resulting cured product tends to increase. Therefore, the total amount of monofunctional (meth)acrylic compound relative to the total amount of photocurable compound (C) is preferably 20% by mass or less, and more preferably 10% by mass or less.

[0044] The weight-average molecular weight of the above (meth)acrylic compound, as measured by gel permeation chromatography (GPC), is preferably 200 to 10,000, and more preferably 200 to 5,000.

[0045] On the other hand, the (meth)acrylic-modified epoxy compound is any compound having one or more epoxy groups and one or more (meth)acryloyl groups in its molecule, and the number of epoxy groups and (meth)acryloyl groups is not particularly limited. For example, it may have one epoxy group and one (meth)acryloyl group, or it may have two or more of either one or both. The (meth)acrylic-modified epoxy compound has good compatibility with the thermosetting compound (A) described above. Therefore, if the photocurable compound (C) contains the (meth)acrylic-modified epoxy compound, their compatibility becomes very good.

[0046] (Meth)acrylic-modified epoxy compounds are compounds obtained by modifying some of the epoxy groups of a bifunctional or more epoxy compound with (meth)acrylic acid. The epoxy compound used for this modification only needs to have two or more epoxy groups in its molecule, and bifunctional epoxy compounds are preferred from the viewpoint of suppressing excessive reduction in the adhesive strength of the sealant due to excessively high crosslinking density. Examples of bifunctional epoxy compounds include bisphenol-type epoxy compounds (bisphenol A type, bisphenol F type, 2,2'-diallylbisphenol A type, bisphenol AD ​​type, and hydrogenated bisphenol type, etc.), biphenyl-type epoxy compounds, and naphthalene-type epoxy compounds. Among these, bisphenol A type and bisphenol F type bisphenol-type epoxy compounds are preferred from the viewpoint of easily improving the coatability of the resin composition (liquid crystal sealant). (Meth)acrylic-modified epoxy compounds derived from bisphenol-type epoxy compounds have advantages such as superior coatability compared to (meth)acrylic-modified epoxy compounds derived from biphenyl ether-type epoxy compounds.

[0047] The weight-average molecular weight of the (meth)acrylic-modified epoxy compound, as measured by gel permeation chromatography (GPC), is preferably 300 to 1000.

[0048] Whether the photocurable compound (C) is a (meth)acrylic compound or a (meth)acrylic-modified epoxy compound, the (meth)acrylic equivalent is preferably 2500 or less, and more preferably 1000 or less. When the (meth)acrylic equivalent is 1000 or less, the photocurability is good, but the moisture permeability of the resulting sealant tends to be low. The (meth)acrylic equivalent is the value obtained by dividing the molecular weight of the (meth)acrylic compound or meth)acrylic-modified epoxy compound by the number of (meth)acrylic groups in the molecule, and the molecular weight is measured in polystyrene equivalent by gel permeation chromatography (GPC).

[0049] The total amount of the above-mentioned photocurable compound (C) is preferably 30% to 70% by mass, and more preferably 40% to 60% by mass, relative to the total amount of the resin composition. When the total amount of photocurable compound (C) is within this range, the photocurability of the resin composition is better and liquid crystal contamination tends to be lower.

[0050] 1-4. Photopolymerization initiator (D) The photopolymerization initiator (D) is not particularly limited as long as it is a compound capable of polymerizing the above-mentioned photocurable compound (C) by irradiation with light. The photopolymerization initiator (D) may be a self-cleaving type photopolymerization initiator or a hydrogen abstraction type photopolymerization initiator. The resin composition may contain only one type of photopolymerization initiator (D) or two or more types.

[0051] Examples of self-cleaving photopolymerization initiators include alkylphenone compounds (such as benzyldimethyl ketal compounds like 2,2-dimethoxy-1,2-diphenylethane-1-one (BASF, IRGACURE 651); α-aminoalkylphenone compounds like 2-methyl-2-morpholino(4-thiomethylphenyl)propan-1-one (BASF, IRGACURE 907); and 1-hydroxycyclohexylphenyl ketone (BASF, IRGACURE 907) α-hydroxyalkylphenone compounds such as 184); acylphosphine oxide compounds such as 2,4,6-trimethylbenzoindiphenylphosphine oxide; titanocene compounds such as bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)-phenyl)titanium; diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy)phenyl-(2- This includes acetophenone compounds such as hydroxy-2-propyl)ketone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-2-morpholino(4-thiomethylphenyl)propan-1-one, and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone; phenylglyoxylate compounds such as methylphenylglyoxyester; benzoin ether compounds such as benzoin, benzoin methyl ether, and benzoin isopropyl ether; and oxime ester compounds such as 1,2-octanedione-1-[4-(phenylthio)-2-(O-benzoyloxime)] (BASF, IRGACURE OXE01) and ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyloxime) (BASF, IRGACURE OXE02).

[0052] Examples of hydrogen abstraction type photopolymerization initiators include benzophenone compounds such as benzophenone, o-benzoylmethyl-4-phenylbenzophenone, 4,4'-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, acrylic benzophenone, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, and 3,3'-dimethyl-4-methoxybenzophenone; thioxanthone, 2-chlorothioxanthone (manufactured by Tokyo Chemical Industry Co., Ltd.), 1-chloro-4-propoxythioxanthone, 1-chloro-4-ethoxythioxanthone (manufactured by Lambson Limited, Speedcure CPTX), 2-isopropylxanthone (manufactured by Lambson Limited, Speedcure ITX), 4-isopropylthioxanthone, 2,4-dimethylthioxanthone, and 2,4-diethylthioxanthone (Lambson Limited). This includes thioxanthone compounds such as Speedcure DETX (manufactured by Limited) and 2,4-dichlorothioxanthone; anthraquinone compounds such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone, 2-hydroxyanthraquinone (manufactured by Tokyo Chemical Industries, Ltd., 2-Hydroxyanthraquinone), 2,6-dihydroxyanthraquinone (manufactured by Tokyo Chemical Industries, Ltd., Anthraflavic Acid), and 2-hydroxymethylanthraquinone (manufactured by Junsei Chemical Co., Ltd., 2-(Hydroxymethyl)anthraquinone); and benzyl compounds.

[0053] The absorption wavelength of the photopolymerization initiator (D) is not particularly limited, but a photopolymerization initiator (D) that absorbs light with a wavelength of 360 nm or more is preferred. Among these, it is more preferable that it absorbs light in the visible light region, and a photopolymerization initiator (D) that absorbs light with a wavelength of 360 to 430 nm is particularly preferred. When the photopolymerization initiator (D) has an absorption wavelength in this range, it becomes possible to cure the resin composition by visible light irradiation, and the influence on liquid crystal materials and the like can be greatly reduced. In this specification, the "visible light region" is defined as the wavelength range of 360 nm to 780 nm.

[0054] Examples of photopolymerization initiators (D) that absorb light with a wavelength of 360 nm or more include alkylphenone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, titanocene-based photopolymerization initiators, oxime ester-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, and anthraquinone-based photopolymerization initiators, among which oxime ester-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, and anthraquinone-based photopolymerization initiators are preferred.

[0055] The structure of the photopolymerization initiator (D) can be determined by combining high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC / MS) with NMR or IR measurements.

[0056] The molecular weight of the photopolymerization initiator (D) is preferably, for example, 200 to 5000. If the molecular weight is 200 or more, the photopolymerization initiator (D) is less likely to dissolve into the liquid crystal material when the resin composition is used as a liquid crystal sealant. On the other hand, if the molecular weight is 5000 or less, the compatibility with the photocurable compound (C) is increased, and the photocurability of the resin composition tends to be good. The molecular weight of the photopolymerization initiator (D) is more preferably 230 to 3000, and even more preferably 230 to 1500.

[0057] The molecular weight of the photopolymerization initiator (D) can be determined as the "relative molecular mass" of the main peak detected when analyzed by high-performance liquid chromatography (HPLC).

[0058] Specifically, a sample solution is prepared by dissolving the photopolymerization initiator (D) in THF (tetrahydrofuran), and high-performance liquid chromatography (HPLC) measurement is performed. The area percentage of the detected peaks (the ratio to the sum of the areas of each peak) is then determined to confirm the presence or absence of a main peak. The main peak is defined as the peak with the highest intensity (the peak with the highest height) among all peaks detected at the detection wavelength characteristic of each compound (for example, 400 nm for thioxanthone compounds). The relative molecular mass corresponding to the peak peak of the detected main peak can be measured by liquid chromatography-mass spectrometry (LC / MS).

[0059] The amount of photopolymerization initiator (D) is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, even more preferably 0.1 to 3% by mass, and particularly preferably 0.1 to 2.5% by mass, relative to the total amount of photocurable compound (C). When the amount of photopolymerization initiator (D) is 0.01% by mass or more relative to the total amount of photocurable compound (C), the photocurability of the resin composition tends to be good. On the other hand, when the content of photopolymerization initiator (D) is 10% by mass or less, the photopolymerization initiator (D) does not easily dissolve into the liquid crystal when the resin composition is used as a liquid crystal sealant.

[0060] 1-5. Inorganic fillers (E) The resin composition may further contain an inorganic filler (E). When the resin composition contains an inorganic filler (E), the hardness of the resin composition tends to increase and the moisture permeability tends to decrease further. The resin composition may contain only one type of inorganic filler (E), or it may contain two or more types.

[0061] Examples of inorganic fillers (E) include calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum silicate, zirconium silicate, iron oxide, titanium oxide, titanium nitride, alumina other than those listed above, zinc oxide, silicon oxide (silica), potassium titanate, kaolin, talc, glass beads, sericite activated clay, bentonite, aluminum nitride, and silicon nitride. Among these, silica, alumina, or talc are preferred from the viewpoint of availability and stability.

[0062] The shape of the inorganic filler (E) may be fixed, such as spherical, plate-shaped, or needle-shaped, or it may be irregular. When the inorganic filler is spherical, the average primary particle diameter of the inorganic filler is preferably 1.5 μm or less. Also, the specific surface area of ​​the inorganic filler is 0.5 m². 2 / g or more 20m 2 A value of less than / g is preferred. The average primary particle size of the inorganic filler can be measured by the laser diffraction method described in JIS Z8825 (2013). The specific surface area of ​​the filler is measured by the BET method described in JIS Z8830 (2013).

[0063] The amount of inorganic filler (E) in the resin composition is preferably 10 parts by mass or more, and more preferably 13 parts by mass or more and 30 parts by mass or less, per 100 parts by mass of the total amount of thermosetting compound (A), latent thermosetting agent (B), photocurable compound (C), and photopolymerization initiator (D). Furthermore, the amount of inorganic filler (E) is preferably 10 parts by mass or more and 40 parts by mass or less, and more preferably 14 parts by mass or more and 30 parts by mass or less, relative to the total amount of the resin composition. If the content of inorganic filler (E) is high, the moisture permeability of the resulting sealant tends to be low. However, if it is excessively high, the coatability of the resin composition will decrease, so the above range is preferred.

[0064] 1-6. Silane coupling agent (F) The resin composition may further contain a silane coupling agent (F). When the resin composition contains a silane coupling agent (F), the adhesive strength between the resulting encapsulant and the substrate or orientation film tends to be further increased.

[0065] Examples of silane coupling agents include vinyltrimethoxysilane, γ-(meth)acryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and 3-glycidoxypropyltrimethoxysilane.

[0066] The amount of silane coupling agent (F) is preferably 1% by mass or more and 20% by mass or less relative to the total amount of the resin composition. When the silane coupling agent content is within this range, as described above, the adhesive strength between the resulting encapsulant and the substrate or alignment film tends to be further increased.

[0067] 1-7. Core-shell type microparticles (G) The resin composition may further contain core-shell type fine particles (G). Core-shell type fine particles are fine particles having a core with desired physical properties and a shell portion covering the core. The shell portion makes it possible to increase compatibility with other components or to partially react with other components. In addition, when the resin composition contains the core-shell type fine particles (G), it absorbs and expands the surrounding material when heated, resulting in reduced liquid crystal contamination. The resin composition may contain only one type of core-shell type fine particles (G), or it may contain two or more types.

[0068] Examples of core-shell type microparticles (G) include organic microparticles having an elastic core containing conjugated diene rubber and silicone rubber, and a shell portion made of polymers such as (meth)acrylate, vinyl monomer, and epoxy monomer.

[0069] Another example of core-shell type fine particles (G) includes fine particles having a core made of inorganic particles and a shell made of a polymer layer covering the core, with a functional group containing a carbon-carbon double bond on its surface. Examples of functional groups containing a carbon-carbon double bond on such core-shell type fine particles include vinyl groups, allyl groups, acrylic groups, methacrylic groups, etc. The core in such core-shell type fine particles includes particles similar to those of the inorganic filler (E) described above. Among these, silica particles are preferred from the viewpoint of excellent thermal stability.

[0070] The average primary particle diameter of the core-shell type fine particles (G) is preferably 0.1 to 1.0 μm, more preferably 0.2 to 0.8 μm, and even more preferably 0.3 to 0.5 μm. The average primary particle diameter of the core-shell type fine particles (G) can be determined by microscopy. Specifically, it can be measured by image analysis using an electron microscope. More specifically, image analysis is performed on the liquid crystal sealant, 50 organic fillers with a particle diameter of 1 μm or less are selected, and the average value obtained when measuring the particle diameter is taken as the average particle diameter.

[0071] The amount of core-shell type fine particles (G) is preferably 1% to 12% by mass, and more preferably 5% to 10% by mass, relative to the total amount of the resin composition. When the content of core-shell type fine particles (G) is within this range, it becomes easier to further adjust the physical properties of the resulting encapsulant to the desired range.

[0072] 1-8. Other ingredients The resin composition of the present invention may further contain various additives as needed. Examples of various additives include thermal radical polymerization initiators, ion trapping agents, ion exchangers, leveling agents, pigments, dyes, sensitizers, plasticizers, and defoaming agents.

[0073] Furthermore, the resin composition may include spacers or the like for adjusting the gap of the liquid crystal display panel.

[0074] The total amount of other components is preferably 1% by mass or more and 50% by mass or less of the total amount of the resin composition, and more preferably 1% by mass or more and 25% by mass or less. When the total amount of other components is 50% by mass or less of the resin composition, the viscosity of the resin composition is less likely to increase excessively, and the coating stability of the resin composition is less likely to be impaired.

[0075] 1-9. Physical properties of resin compositions The resin composition of the present invention is applied to a thickness of 100 μm, and exposed to light with a wavelength of 370 nm to 450 nm with an integrated light intensity of 3000 mJ / cm². 2After irradiating so as to obtain the following, for a film cured by heating at 120°C for 1 hour, the moisture permeability at 60°C, 90% Rh, for 24 hours, measured in accordance with JIS Z0208:1976, is less than 100 g / m 2 The moisture permeability is preferably 90 g / m 2 or less, more preferably 85 g / m 2 or less. When the moisture permeability under the above conditions is less than 100 g / m 2 it becomes possible to stably use the liquid crystal display panel over a long period. In the measurement of the moisture permeability, an aluminum cup is produced from the film cured under the above curing conditions, and this is left standing in a high temperature and high humidity bath at 60°C and 90% Rh. Then, the moisture permeability is calculated from the mass before and after leaving it standing in the high temperature and high humidity bath using the following calculation formula. Moisture permeability (g / m 2 ·100 μm·24 h) = [weight of aluminum cup after standing for 24 hours (g) - weight of aluminum cup before standing for 24 hours (g)] / film area (m 2 )

[0076] On the other hand, the viscosity of the resin composition at 25°C and 2.5 rpm measured with an E-type viscometer is preferably 200 to 450 Pa·s, more preferably 250 to 400 Pa·s. When the viscosity is within the above range, it becomes easier to apply the resin composition with a dispenser or the like.

[0077] Here, the resin composition can be used as a liquid crystal sealant as described above. The liquid crystal sealant may contain only the above resin composition, or may be a mixture of the resin composition and other components as necessary.

[0078] The liquid crystal sealant is mainly useful as a sealant for liquid crystal display panels, but is also useful as a sealant for display elements other than liquid crystal display panels, such as organic EL elements and LED elements.

[0079] 2. Liquid Crystal Display Panel and Method for Manufacturing the Same (Structure of Liquid Crystal Display Panel) The liquid crystal display panel of the present invention includes a pair of substrates, a pair of alignment films disposed between the pair of substrates, a liquid crystal layer sandwiched between the pair of alignment films, and a sealing material for sealing the liquid crystal layer. The sealing material is a cured product of the above-described resin composition (liquid crystal sealant).

[0080] Both substrates in the pair are transparent. The material of the transparent substrate may be an inorganic material such as glass, or a plastic such as polycarbonate, polyethylene terephthalate, polyethersulfone, and PMMA. A matrix of TFTs, a color filter, a black matrix, etc., may be arranged on the surface of each substrate.

[0081] Furthermore, an alignment film is placed on the inside (liquid crystal layer side) of each substrate. The type of alignment film is not particularly limited and includes films made of known organic or inorganic alignment agents. The alignment film may be placed so as to cover substantially the entire surface of one side of each substrate, that is, extending from one end of the substrate to the other end. Alternatively, the alignment film may be placed so as to cover only a portion of the substrate, or there may be a gap between the edge of the alignment film and the edge of the substrate.

[0082] Furthermore, the liquid crystal layer may be any layer made of liquid crystal material sandwiched between the alignment films, and the type of liquid crystal material is not particularly limited. The sealing material is a frame-shaped structure arranged to surround the liquid crystal layer. In the liquid crystal display panel of the present invention, the sealing material may be arranged so as to be sandwiched between alignment films.

[0083] As described above, conventional sealing materials have difficulty sufficiently increasing the adhesive strength with the alignment film. However, by using the resin composition described above, the adhesive strength between the alignment film and the sealing material can be increased even when the sealing material is fabricated on the alignment film. Therefore, the above resin composition (liquid crystal sealant) is very useful in embodiments where the bezel of a liquid crystal display panel is narrowed.

[0084] (Manufacturing method for liquid crystal display panels) Liquid crystal display panels are manufactured using the liquid crystal sealant of the present invention. Generally, there are two methods for manufacturing liquid crystal display panels: liquid crystal drop method and liquid crystal injection method. However, the liquid crystal display panels of the present invention are preferably manufactured using the liquid crystal drop method.

[0085] The method for manufacturing liquid crystal display panels using the liquid crystal drop method is: 1) A step of preparing two substrates with alignment films, each having a substrate and an alignment film. 2) A step of applying the above-mentioned liquid crystal sealant (resin composition) to the surface on which the alignment film is formed on one of the substrates with the alignment film, to form a frame-shaped pattern, 3) A step of dropping liquid crystal onto the inside of the frame-shaped pattern on one substrate with alignment film, or onto the other substrate with alignment film, while the frame-shaped pattern is still uncured. 4) A step of stacking one substrate with an alignment film and the other substrate with an alignment film via a frame-shaped pattern, 5) A step of curing a frame-shaped pattern.

[0086] In step 2), the area to which the liquid crystal sealant (resin composition) is applied is appropriately selected according to the desired structure of the liquid crystal display panel. For example, when the sealing material is placed on the alignment film, the liquid crystal sealant (resin composition) is applied on the alignment film. The method of applying the liquid crystal sealant (resin composition) is not particularly limited as long as it is possible to apply the liquid crystal sealant (resin composition) in the desired width, but it can be applied by means of a dispenser, for example.

[0087] On the other hand, in step 3), the state in which the frame-shaped pattern is uncured means that the curing reaction of the liquid crystal sealant has not progressed to the gelation point. For this reason, in step 3), the frame-shaped pattern may be partially cured by light irradiation or heating in order to suppress the dissolution of the liquid crystal sealant into the liquid crystal. Also, when dropping liquid crystal onto the other alignment film substrate in step 3), the liquid crystal should be dropped in such a way that when the two alignment film substrates are stacked in step 4), the liquid crystal will be contained within the frame-shaped pattern.

[0088] In step 5), it is preferable to perform curing by heat after curing by light irradiation. By performing curing by light irradiation first, the liquid crystal sealant can be cured in a short time, thereby suppressing dissolution into the liquid crystal. In addition, by combining curing by light irradiation and curing by heat, damage to the liquid crystal layer caused by light can be reduced compared to curing by light irradiation alone.

[0089] The light to be irradiated is appropriately selected depending on the type of photopolymerization initiator (D) in the liquid crystal sealant (resin composition) described above, but visible light is preferred, for example, light with a wavelength of 370 to 450 nm is preferred. Light of the above wavelength causes relatively little damage to the liquid crystal material and drive electrodes. For light irradiation, known light sources that emit ultraviolet or visible light can be used. When irradiating with visible light, high-pressure mercury lamps, low-pressure mercury lamps, metal halide lamps, xenon lamps, fluorescent lamps, etc. can be used.

[0090] The light irradiation energy should be sufficient to allow the photocurable compound (C) to cure. The photocuring time depends on the composition of the liquid crystal sealant, but is typically around 10 minutes.

[0091] The curing temperature depends on the composition of the liquid crystal sealant, but for example, it is 120°C, and the curing time is about 2 hours. [Examples]

[0092] The present invention will be described in detail below with reference to examples, but the scope of the present invention is not limited to the examples.

[0093] 1. Preparation of materials (Thermosetting compound (A)) • Carboxylated acrylonitrile-butadiene rubber-modified bisphenol A type epoxy resin (TSR-601, manufactured by DIC Corporation, epoxy equivalent weight 450-500, molecular weight: 948) • Bisphenol A type PO-modified epoxy resin (EP-4003S, manufactured by ADEKA, epoxy equivalent weight 470, molecular weight: 940) • Epoxy-modified polybutadiene (PB4700, manufactured by Daicel Corporation, epoxy equivalent weight 165, number average molecular weight: 3000)

[0094] (Latent thermosetting agent (B)) • Polyamine-based thermal latent curing agent (EH-4357S, manufactured by ADEKA, melting point: 80°C) • Imidazole-based heat-latent curing agent (EH-4344S, manufactured by ADEKA, softening point: 110°C) • Dihydrazide-based heat-latent curing agent (ADH, manufactured by Nippon Finechem Co., Ltd., melting point: 180°C)

[0095] (Photocurable compound (C)) • Bifunctional acrylic compound (Ebecryl 3700, manufactured by Daicel Ornex Co., Ltd.) • Acrylic-modified epoxy resin (NeoChemical Co., Ltd., BEAM-50, methacrylic modification ratio: 50%) • Monofunctional acrylic resin (HOP-A, manufactured by Kyoei Chemical Co., Ltd.) • Bifunctional polybutadiene urethane acrylic resin (TE-2000, manufactured by Nippon Soda Co., Ltd., acrylic equivalent: 2000, number average molecular weight: 4000)

[0096] (Photopolymerization initiator (D)) • Oxime ester type (OXE-02, manufactured by BASF) • α-aminoketone system (visible light compatible, Omnipol-910, manufactured by IGM) • Thioxanthone-based (compatible with visible light, photopolymerization initiator prepared in Synthesis Example 1 below) • Anthraquinone-based (visible light compatible, photopolymerization initiator prepared in Synthesis Example 2 below)

[0097] (Synthesis Example 1) 5.00 g (1.74 × 10⁻¹) of 2-(2-hydroxyethylthio)-thioxanthene-9-one synthesized by known methods was added to a four-necked flask equipped with a stirrer, nitrogen gas inlet tube, reflux condenser, and thermometer. -2After adding (mol) and 50g of toluene and stirring at 80°C, one drop of dibutyltin was added as a catalyst. Next, a solution of 4.51g of hexamethylene diisocyanate allophanate modified product (Takenate D-178NL, Mitsui Chemicals, isocyanate equivalent 216.1g / eq) dissolved in 10g of toluene was added dropwise over 30 minutes, and the mixture was stirred at 80°C under a nitrogen atmosphere for 3 hours. After the reaction was complete, the four-necked flask was allowed to cool at room temperature and the solid components were separated. The recovered solid components were thoroughly dried in an oven to obtain a thioxanthone-based photopolymerization initiator.

[0098] (Synthesis Example 2) 5.0 g of 2-(2-hydroxyethylthio)-9,10-anthraquinone (1.76 × 10⁻¹) was added to a four-necked flask equipped with a stirrer, nitrogen gas inlet tube, reflux condenser, and thermometer. -2 After adding 150g of toluene and stirring at 80°C, one drop of dibutyltin was added as a catalyst. Next, a solution of 3.98g of hexamethylene diisocyanate allophanate modified product (Takenate D-178NL, Mitsui Chemicals, isocyanate equivalent 216.1g / eq) dissolved in 10g of toluene was added dropwise over 30 minutes, and the mixture was stirred at 80°C for 2 hours under a nitrogen atmosphere. After the reaction was complete, the four-necked flask was cooled in an ice bath and the precipitated crystalline components were separated. The obtained crystalline components were mixed again with toluene and stirred at 100°C for 1 hour, then cooled again with ice to remove impurities. The recovered crystalline components were thoroughly dried in an oven to initiate anthraquinone-based photopolymerization.

[0099] (Inorganic filler (E)) • Silica particles (SO-C1, manufactured by Admatex Co., Ltd.) • Alumina particles (DAW-01, manufactured by Denka Co., Ltd.)

[0100] (Silane coupling agent (F)) • Silane coupling agent (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0101] (Core-shell type microparticles (G)) • Core-shell polymer (F351, manufactured by Aica Kogyo Co., Ltd.)

[0102] 2. Preparation of the resin composition (Example 1) A thermosetting compound (A) (CTBN-modified bisphenol A type epoxy compound), a latent thermosetting agent (B), a photocurable compound (C), a photopolymerization initiator (D), an inorganic filler (E), core-shell type fine particles (F), and a silane coupling agent (G) were mixed in the mass ratios shown in Table 1 using a three-roll mixing machine to obtain a resin composition. In this example, this was used as a sealant.

[0103] (Examples 2-7 and Reference Examples 1-5) The resin composition was prepared in the same manner as in Example 1, except that the composition was changed as shown in Table 1.

[0104] (Checking breathability) The moisture permeability of each of the above resin compositions was confirmed by the following procedure. A release film was placed on a rectangular glass plate. Furthermore, a 100 μm thick PET film piece (spacer) was placed on the glass plate so as to surround the release film. Then, the resin compositions prepared in the examples and reference examples were applied onto the release film. After that, the release film and glass plate were placed on the resin composition in that order, and the four sides were fixed with clips so as to sandwich the two glass plates. Then, light including visible light (light with a wavelength of 360 to 450 nm) was applied to an integrated light intensity of 3000 mJ / cm². 2 The material was irradiated in such a manner. The resin composition was then cured by heating at 120°C for 1 hour. After that, the glass plate and release paper were removed to obtain a film with a thickness of 100 μm (cured resin composition). Using the obtained 100 μm film, aluminum cups were prepared according to the method compliant with JIS Z0208:1976 and left in a high-temperature, high-humidity chamber at 60°C and 90% RH for 24 hours. The moisture permeability was then calculated from the mass before and after being left in the high-temperature, high-humidity chamber using the following formula. Moisture permeability (g / m 2 (100μm·24h) = [Weight of aluminum cup after 24 hours (g) - Weight of aluminum cup before 24 hours (g)] / Film area (m²) 2 ) Based on the calculated moisture permeability, the moisture resistance was evaluated according to the following criteria.

[0105] 3. Evaluation The adhesive strength of the cured resin compositions obtained was evaluated using the following method. The results are shown in Table 1.

[0106] For each example and reference example, 2 parts by mass of polymer beads (Sekisui Chemical Co., Ltd.: Micropearl SP) with an average particle size of 5 μm were added to 100 parts by mass of the resin composition, and the polymer beads were dispersed in the resin composition using a planetary stirring device. Next, the resin composition containing the dispersed polymer beads was applied to the center of a 25 mm × 45 mm glass substrate (EAGLE XG, CORNING Corporation) that had a transparent electrode ITO and alignment film NRB-W876 (Nissan Chemical Corporation) pre-formed on it, using a screen printing plate, so that the diameter of the circle after bonding with a thickness of 5 μm would be approximately 3.5 mm, thereby forming a seal pattern. Then, another glass substrate was bonded perpendicularly to the glass substrate on which the seal pattern was formed under atmospheric pressure. Finally, an integrated light intensity of 3000 mJ / cm² was applied. 2 The resin composition was cured by irradiating it with light containing visible light (light with a wavelength of 370-450 nm) and then heating it at 120°C for 1 hour to obtain a test specimen.

[0107] A 0.5 mm section from the center of the short side of the glass specimen was pressed vertically at a speed of 37.5 mm / min using an indentation tester (Model 210, Intesco), and the stress at which the seal peeled off was measured. This stress value was defined as the adhesive strength. The adhesive properties were evaluated based on the following criteria. ○: When the value is 1.1 N / mm or higher △: If less than 1.1 N / mm and 1.0 N / mm or more ×: If less than 1.0 N / mm

[0108] [Table 1]

[0109] As shown in Table 1 above, by combining a thermosetting compound (A) containing a rubber-modified epoxy compound (a), a latent thermosetting agent (B) with a melting point of 110°C or lower, a photocurable compound (C), and a photopolymerization initiator (D), a moisture permeability of 100 g / m² can be achieved. 2 Despite being less than [amount missing], we were able to manufacture a sealing material with good adhesive strength (Examples 1-7).

[0110] This application claims priority under Japanese Patent Application No. 2023-053395, filed on 29 March 2023. All provisions of the said application are incorporated herein by reference. [Industrial applicability]

[0111] According to the present invention, a resin composition capable of forming a sealing material with high adhesive strength to a substrate and high moisture resistance, as well as a liquid crystal sealant containing the same, can be obtained. Therefore, it is extremely useful for applications in various display devices.

Claims

1. Thermosetting compound (A), A latent thermosetting agent (B) with a melting point of 110°C or lower, A photocurable compound (C) having an ethylenically unsaturated double bond in its molecule, Photopolymerization initiator (D), Inorganic filler (E), Silane coupling agent (F), Includes, The thermosetting compound (A) is a resin composition containing a rubber-modified epoxy compound (a) having an epoxy group, an acrylonitrile-butadiene rubber structure, and a bisphenol A type structure within one molecule. The average molecular weight of the rubber-modified epoxy compound (a), as identified by gel permeation chromatography, is 2000 or less. The amount of the rubber-modified epoxy compound (a) is 10 parts by mass or more and 25 parts by mass or less, relative to 100 parts by mass of the total of the thermosetting compound (A) and the photocurable compound (C). The amount of the monofunctional (meth)acrylic compound is 20% by mass or less relative to the total amount of the photocurable compound (C). The resin composition is coated to a thickness of 100 μm, and light with a wavelength of 370 nm to 450 nm is applied to an integrated light intensity of 3000 mJ / cm². ２ After irradiating the film in this manner, it was cured by heating it at 120°C for 1 hour. The moisture permeability measured in accordance with JIS Z0208:1976 at 60°C and 90% Rh for 24 hours was 100 g / m². ２ Less than, Resin composition.

2. The epoxy equivalent of the rubber-modified epoxy compound (a) is 300 or more and 1000 or less. The resin composition according to claim 1.

3. The inorganic filler (E) is at least one selected from the group consisting of silica, alumina, and talc. The resin composition according to claim 1.

4. The latent thermosetting agent (B) is at least one selected from the group consisting of imidazole-based latent thermosetting agents, amine adduct-based latent thermosetting agents, and polyamine-based latent thermosetting agents. The resin composition according to claim 1.

5. Further comprising core-shell type microparticles (G), The resin composition according to claim 1.

6. The photopolymerization initiator (D) is at least one selected from the group consisting of oxime ester-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, and anthraquinone-based photopolymerization initiators. The resin composition according to claim 1.

7. A resin composition comprising the resin composition according to any one of claims 1 to 6, Liquid crystal sealant.

8. The stress obtained during the indentation test in the following test is 1.0 N / mm or greater. The liquid crystal sealant according to claim 7. (Indentation test method) (i) Disperse 2 parts by mass of spacer polymer beads (Sekisui Chemical Co., Ltd.: Micropearl SP) with an average particle size of 5 μm in 100 parts by mass of the liquid crystal sealant. (ii) Prepare a pair of 25 mm x 45 mm glass substrates (EAGLE XG, manufactured by CORNING) on which transparent electrodes made of ITO and alignment films are arranged, and apply the liquid crystal sealant in which the spacer polymer beads are dispersed to the center of one of the glass substrates so that the diameter is 3.5 mm and the thickness is 5 μm. (iii) The other glass substrate is placed on top of it via the liquid crystal sealant. (iv) The total light intensity is 3000 mJ / cm ２ To achieve this, light with a wavelength of 360-450 nm is irradiated, and the material is cured at 120°C for 1 hour. (v) The stress is measured when a 0.5 mm portion of the other glass substrate is pressed in from the center of the short side towards the center using a press test machine at a speed of 37.5 mm / min.

9. A pair of circuit boards, An alignment film sandwiched between the pair of substrates, A liquid crystal layer sandwiched between the pair of alignment films, A sealing material for sealing the liquid crystal layer, It is a liquid crystal display panel that includes, The sealing material is a cured product of the liquid crystal sealant described in claim 7. LCD display panel.

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