Resin composition, liquid crystal sealing agent, and liquid crystal display panel using 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 having low moisture permeability during curing. The resin composition comprises a thermosetting compound (A), a latent thermosetting agent (B) having a melting point of 110 DEG C or less, and a photocurable compound (C) having an ethylenically unsaturated double bond in the molecule. And a photopolymerization initiator (D). The thermosetting compound (A) contains a rubber-modified epoxy compound (a) having an epoxy group, an acrylonitrile-butadiene rubber structure, and a bisphenol A-type structure in one molecule. The moisture permeability of the resin composition under predetermined conditions is less than 100 g / m2.

Description

Technical Field

[0001] This 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 (LCD) panels have become the most common type of display device used for various applications. A typical LCD panel comprises a pair of substrates with electrodes on their surfaces, a pair of alignment films disposed 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 located at the frame edge outside the effective display area of ​​the LCD panel.

[0003] From the viewpoint of preventing liquid crystal material from leaking out of the liquid crystal layer, the aforementioned sealing material is required to have high adhesion strength to the substrate. Therefore, the adhesion strength is improved by chemically bonding functional groups (e.g., OH groups) on the substrate surface to functional groups (e.g., epoxy groups) on the sealing material surface (e.g., patent document 1). On the other hand, the sealing material is also required to have low moisture permeability, preventing external moisture from permeating to the liquid crystal side.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2005-018022 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] In recent years, there has been a demand to reduce the width of the frame portion of liquid crystal display panels. Reducing the frame portion width results in a very short distance from the end of the alignment film to the end of the liquid crystal display panel, where the alignment film is placed (the area where the sealing material is formed). However, most alignment films are hydrophobic. Therefore, it is difficult to form chemical bonds between the sealing material and the alignment film, and sufficient adhesive strength is difficult to achieve with conventional materials. Furthermore, in particular, reducing the moisture permeability of the sealing material easily leads to a decrease in the adhesive strength between the substrate, the alignment film, and the sealing material. In other words, it is very difficult to form a sealing material that combines high adhesive strength with the substrate and the alignment film with low moisture permeability.

[0009] The present invention was made in view of the above-mentioned problems, and its object is to provide a resin composition, a liquid crystal sealant, and a liquid crystal display panel using the same, which exhibits high adhesive strength to the substrate and alignment film of a liquid crystal display panel despite having low moisture permeability during curing.

[0010] Solution to the problem

[0011] This invention provides a resin composition comprising: a thermosetting compound (A), a potential thermosetting agent (B) with a melting point below 110°C, a photocurable compound (C) having an intramolecular vinyl unsaturated double bond, and a photopolymerization initiator (D). The thermosetting compound (A) includes a rubber-modified epoxy compound (a) having an intramolecular epoxy group, an acrylonitrile-butadiene rubber structure, and a bisphenol A type structure. Regarding the following film, when the resin composition is coated to a thickness of 100 μm, the cumulative light intensity is 300 mJ / cm. 2 The film, cured by irradiating it with light of wavelengths above 370nm and below 450nm and then heating it at 120℃ for 1 hour, has a moisture permeability of less than 100g / m³ at 60℃ and 90% relative humidity (Rh) for 24 hours, as measured by Japanese Industrial Standard (JIS) Z0208:1976. 2 .

[0012] The present invention further provides a liquid crystal sealant comprising the above-described resin composition.

[0013] 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 in the liquid crystal display panel is a cured product of the aforementioned liquid crystal sealant.

[0014] Invention Effects

[0015] Despite having low moisture permeability during curing, the resin composition of the present invention still exhibits high adhesion strength to the substrate and alignment film of the liquid crystal display panel. Detailed Implementation

[0016] In this specification, the numerical range indicated by “~” refers to the range including the values ​​recorded before and after “~” as the lower and upper limits.

[0017] 1. Resin composition (liquid crystal sealant)

[0018] The resin composition of the present invention is a composition that can be cured by heat and light, and can be used, for example, in liquid crystal sealants. Hereinafter, the application of the resin composition to a liquid crystal sealant, which is used to form a sealing material for a liquid crystal display panel, will be described as an example; however, the use of this resin composition is not limited to liquid crystal sealants.

[0019] The resin composition of the present invention comprises at least a thermosetting compound (A) containing a specific rubber-modified epoxy compound (a), a potential thermosetting agent (B) with a melting point below 110°C, a photocurable compound (C) having an intramolecular vinyl unsaturated double bond, and a photopolymerization initiator (D). The resin composition may further comprise, as needed, an inorganic filler (E), a silane coupling agent (F), core-shell microparticles (G), etc. Furthermore, as described later, the moisture permeability of the resin composition when cured under specified conditions is below a certain value.

[0020] As mentioned above, the adhesion strength of the cured liquid crystal sealant (also referred to as "sealing material" in this specification) to the substrate and alignment film, as well as its low moisture permeability, are inversely related, making it difficult to achieve a balance between them.

[0021] In contrast, the resin composition of the present invention exhibits high adhesion strength to the substrate, alignment film, etc. of the liquid crystal display panel, even though the moisture permeability after curing is below a certain value. The reason for this is not yet certain, but it is believed to be as described below. In the resin composition of the present invention, 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 within one molecule. This rubber-modified epoxy compound (a) has relatively soft properties due to its acrylonitrile-butadiene rubber structure. Therefore, the sealing material obtained by curing this resin composition readily follows the deformation of the substrate, etc., thus preventing peeling at the interface between the substrate or alignment film and the sealing material. Furthermore, when external force is applied to the liquid crystal display panel, the stress can be mitigated by the sealing material. Therefore, the adhesion strength between the sealing material and the substrate and alignment film becomes very high.

[0022] On the other hand, the bisphenol A backbone of the rubber-modified epoxy compound (a) easily blocks moisture from entering the interior of the sealing material from the outside. Therefore, the moisture permeability described later can be achieved. That is, with the resin composition of the present invention, a sealing material with high adhesion strength to the substrate and alignment film of the liquid crystal display panel and low moisture permeability can be obtained.

[0023] The components of the resin composition of the present invention will be described in detail below.

[0024] 1-1. Thermosetting compounds (A)

[0025] Thermosetting compound (A) can be any compound that is cured by heating, and at least part or all of it is the rubber-modified epoxy compound (a) described above.

[0026] The aforementioned rubber-modified epoxy compound (a) is any compound having at least one epoxy group, an acrylonitrile-butadiene rubber structure, and a bisphenol A type structure within one molecule, and its structure is not particularly limited. The number of epoxy groups in the rubber-modified epoxy compound (a) may be one, but from the viewpoint of thermosetting, two or more are preferred.

[0027] Examples of this rubber-modified epoxy compound (a) include compounds in which epoxy groups are bonded to the ends of a chain-like acrylonitrile-butadiene rubber structure via a bisphenol A-type structure. This rubber-modified epoxy compound (a) can be, for example, a compound synthesized using the following method. First, an acrylonitrile-butadiene rubber of the desired molecular weight is prepared, and the ends of the acrylonitrile-butadiene rubber are modified using a known method with a compound having functional groups capable of reacting with epoxy groups. Examples of groups capable of reacting with epoxy groups include carboxyl, amino, and hydroxyl groups, among which, from the viewpoint of reactivity, carboxyl is preferred. On the other hand, a multifunctional epoxy compound having a bisphenol A-type structure is prepared. This multifunctional epoxy compound can be synthesized, for example, by reacting bisphenol A with epichlorohydrin. Furthermore, by reacting the functional groups (e.g., carboxyl groups) of the modified acrylonitrile-butadiene rubber with the epoxy groups of the multifunctional epoxy compound, a rubber-modified epoxy compound (a) having epoxy groups at both ends can be obtained. The structure of rubber-modified epoxy compounds can be determined, for example, by fractionation using gel permeation chromatography (GPC) followed by gas chromatography / mass spectrometry (GC / MS) and nuclear magnetic resonance (NMR). Furthermore, these rubber-modified epoxy compounds can also be commercially available. Examples of commercially available products include TSR-601 and TSR-060 (both manufactured by DIC).

[0028] The epoxy equivalent of the aforementioned rubber-modified epoxy compound (a) is preferably 300 or more and 1000 or less, more preferably 400 or more and 600 or less. If the epoxy equivalent is 300 or more, the adhesion strength between the obtained sealing material and the substrate and alignment film of the liquid crystal display panel is more easily improved. On the other hand, if the epoxy equivalent of the rubber-modified epoxy compound (a) is 1000 or less, it will not become excessively soft, and the obtained sealing material can easily and stably seal the liquid crystal. Furthermore, it prevents a significant deterioration in moisture permeability. The aforementioned epoxy equivalent is a value obtained by dividing the molecular weight of the rubber-modified epoxy compound (a) by the number of epoxy groups present in that molecule, and the average molecular weight can be determined by gel permeation chromatography (GPC).

[0029] Furthermore, the molecular weight of the aforementioned rubber-modified epoxy compound (a) is preferably 2000 or less, more preferably 600 or more and 1200 or less. If the average molecular weight of the rubber-modified epoxy compound (a) is 2000 or less, it is easier to improve the coatability of the resin composition and to easily form a sealing material with the desired width. Additionally, from the viewpoint that it is easier to adjust the low moisture permeability described later to the desired range, the molecular weight of the rubber-modified epoxy compound (a) is also preferably 2000 or less.

[0030] The amount of the aforementioned rubber-modified epoxy compound (a) is preferably 10 parts by mass or more and 25 parts by mass or less, more preferably 14 parts by mass or more and 20 parts by mass or less, relative to the total mass of the thermosetting compound (A) and the photocurable compound (C) described later, of 100 parts by mass. If the amount of the rubber-modified epoxy compound (a) is 10 parts by mass or more relative to the total mass of the thermosetting compound (A) and the photocurable compound (C), the moisture permeability of the sealing material is easily further reduced. On the other hand, if the amount of the aforementioned rubber-modified epoxy compound (a) is 25 parts by mass or less, the amount of the photocurable compound (C) is relatively higher, and the photocurability of the resin composition is more likely to be better.

[0031] Thermosetting compound (A) may include other thermosetting compounds besides 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 epoxy groups, compounds having vinyl unsaturated double bonds are classified as photocurable compounds (C) described later and are not included in thermosetting compound (A). Thermosetting compound (A) may contain only one epoxy compound or may contain two or more epoxy compounds.

[0032] The epoxy compound may contain only one epoxy group or more within the molecule. Examples of epoxy compounds include aromatic epoxy compounds, aliphatic epoxy compounds, and alicyclic epoxy compounds. From the viewpoint of making it easier for the moisture permeability of the obtained sealing material to fall within the scope described later, aromatic epoxy compounds are preferred.

[0033] Examples of aromatic epoxy compounds include aromatic polyglycidyl ether compounds obtained by reacting aromatic diols, such as bisphenol A, bisphenol S, bisphenol F, and bisphenol AD, with epichlorohydrin; aromatic polyglycidyl ether compounds obtained by reacting diols modified from these aromatic diols, such as ethylene glycol, propylene glycol, and alkyl glycols; phenolic varnish-type polyglycidyl ether compounds obtained by reacting polyphenols, such as phenolic varnish resins derived from phenol or cresol and formaldehyde, polyolefin phenol, or their copolymers, with epichlorohydrin; and glycidyl ether compounds of xylene-methylphenol resin, etc.

[0034] Preferably, the epoxy compounds are cresol phenolic varnish type epoxy compounds, phenolic phenolic varnish type epoxy compounds, bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, triphenol methane type epoxy compounds, triphenol ethane type epoxy compounds, triphenol type epoxy compounds, dicyclopentadiene type epoxy compounds, diphenyl ether type epoxy compounds, or biphenyl type epoxy compounds.

[0035] Furthermore, the aforementioned epoxy compound can be in liquid or solid form. From the viewpoint of reducing the moisture permeability of the obtained sealing material, a solid epoxy compound is preferred. The softening point of the solid epoxy compound is preferably 40°C or higher and 150°C or lower. The softening point can be determined by the ring and ball method specified in JIS K7234.

[0036] Furthermore, the weight-average molecular weight of the epoxy compound is preferably 300 to 10,000, more preferably 500 to 5,000. The weight-average molecular weight of the epoxy compound is determined by gel permeation chromatography (GPC) and converted to polystyrene.

[0037] Here, the total amount of thermosetting compound (A) in the resin composition (the sum of the aforementioned rubber-modified epoxy compound (a) and other thermosetting compounds) is preferably 30% by mass or more and 70% by mass or less, 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 sealing material 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 higher, and the photocurability of the resin composition tends to be better.

[0038] 1-2. Potential thermosetting agents (B)

[0039] A latent thermosetting agent (B) is a compound that does not cure the thermosetting compound (A) under normal storage conditions (room temperature, visible light, etc.), but will cure these compounds when heated, as long as its melting point is below 110°C. The melting point of the latent thermosetting agent (B) is more preferably above 70°C and below 100°C. For the latent thermosetting agent (B) to function during the curing of the resin composition, the temperature needs to be raised to near its melting point. However, if the temperature of the resin composition is raised to a high temperature, the uncured photocurable compound (C) easily dissolves into the liquid crystal. In contrast, if the melting point of the latent thermosetting agent (B) is below 110°C, such dissolution is less likely to occur. The resin composition may contain only one latent thermosetting agent (B) or two or more.

[0040] The potential thermosetting agent (B) may be suitably selected according to the above-mentioned thermosetting compound (A), and preferably is a curing agent (hereinafter also referred to as "epoxy curing agent") capable of opening the epoxy group of the above-mentioned rubber modified epoxy compound (a) and curing it.

[0041] 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 epoxy curing agents, or it may contain two or more.

[0042] Examples of diacid hydrazide-based heat-latent curing agents with melting points below 110°C include 1,3-bis(hydrazinocarbonylethyl)-5-isopropylhydantoin, 7,11-octadecadiene-1,18-dicarboxyhydrazide, dodecanoic acid diacid hydrazide, and sebacic acid diacid hydrazide.

[0043] Amine adduct-based latent curing agents are latent curing agents composed of addition compounds obtained by reacting a catalytically active amine compound with any compound. Commercially available examples of amine adduct-based 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 Chemicals Co., Ltd.).

[0044] Polyamine-based heat-latent curing agents are heat-latent curing agents with a polymer structure obtained by reacting amines with epoxy resins. Examples of commercially available products include Adeka Hardener EH4339S, Adeka Hardener EH4357S, and Adeka Hardener EH5030S (all manufactured by ADEKA).

[0045] Examples of dicyandiamide-based heat-latent curing agents include dicyandiamide.

[0046] Examples of imidazole-based heat-latent curing agents include ADEKA curing agent EH-4344S, ADEKA curing agent EH-5011S (both manufactured by ADEKA), 2,4-diamino-6-[2'-ethylimidazolyl-(1')]-ethyltriazine, and 2-phenylimidazolium.

[0047] Of the above, from the viewpoint of reactivity, imidazole-based heat latent curing agents, amine adduct-based heat latent curing agents, and polyamine-based heat latent curing agents are preferred.

[0048] The amount of the potential thermosetting agent (B) relative to the total amount of the resin composition 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.

[0049] 1-3. Photocurable compounds (C)

[0050] There are no particular limitations on photocurable compounds (C) as long as they have at least one vinyl unsaturated double bond in the molecule and are capable of polymerization by light. Examples of photocurable compounds include (meth)acrylic acid compounds containing (meth)acryloyl groups but not epoxy groups, and (meth)acrylic acid modified epoxy compounds having both (meth)acryloyl groups and epoxy groups in the molecule.

[0051] (Meth)acrylic acid compounds are defined as compounds containing one or more (meth)acryloyl groups within a molecule and without an epoxy group. The number of (meth)acryloyl groups can be one or more. Examples of monofunctional (meth)acrylic acid compounds containing one (meth)acryloyl group within a molecule include alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, isobornyl methacrylate, dicyclopentyl methacrylate, and 2-hydroxyethyl methacrylate.

[0052] Examples of polyfunctional (meth)acrylate compounds having two or more (meth)acryloyl groups within a 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 a diol obtained by adding more than 4 moles of ethylene oxide or propylene oxide to 1 mole of neopentyl glycol; and di(meth)acrylates derived from 1 mole of bisphenol A or bisphenol F by adding 2 moles of ethylene oxide or propylene oxide. Di(meth)acrylates of diols obtained from propane (bisphenol A type epoxy(meth)acrylates or bisphenol F type epoxy(meth)acrylates); di(meth)acrylates or tri(meth)acrylates of polyols obtained by adding 2 or 3 moles of ethylene oxide or propylene oxide to 1 mole of trimethylolpropane; di(meth)acrylates of diols obtained by adding more than 4 moles of ethylene oxide or propylene oxide to 1 mole of bisphenol A; tris(2-hydroxyethyl)isocyanurate Tri(meth)acrylate; trimethylolpropane tri(meth)acrylate or oligomers thereof; pentaerythritol tri(meth)acrylate or oligomers thereof; dipentaerythritol poly(meth)acrylate; tri(acryloyloxyethyl)isocyanurate; caprolactone-modified tri(acryloyloxyethyl)isocyanurate; caprolactone-modified tri(methacryloyloxyethyl)isocyanurate; alkyl-modified dipentaerythritol poly(meth)acrylate; caprolactone-modified dipentaerythritol poly(meth)acrylate Neopentyl glycol di(meth)acrylate with hydroxytrimethylacetic acid; caprolactone-modified neopentyl glycol di(meth)acrylate with hydroxytrimethylacetic acid; ethylene oxide-modified phosphate (meth)acrylate; ethylene oxide-modified alkylated phosphate (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; and oligomeric (meth)acrylates of neopentyl glycol, trimethylolpropane and pentaerythritol, etc. Preferably, the di(meth)acrylate is derived from a diol obtained by adding 2 moles of ethylene oxide or propylene oxide to 1 mole of bisphenol A or bisphenol F (bisphenol A type epoxy (meth)acrylate or bisphenol F type epoxy (meth)acrylate).

[0053] However, if the amount of monofunctional (meth)acrylic acid compound increases, the moisture permeability of the obtained cured product tends to increase. Therefore, the total amount of monofunctional (meth)acrylic acid compound is preferably 20% by mass or less, more preferably 10% by mass or less, relative to the total amount of photocurable compound (C).

[0054] The weight-average molecular weight of the above-mentioned (meth)acrylic acid compounds, as determined by gel permeation chromatography (GPC), is preferably 200 to 10,000, more preferably 200 to 5,000.

[0055] On the other hand, the (meth)acrylic acid modified epoxy compound can be any compound having one or more epoxy groups and one or more (meth)acryloyl groups within its molecule; the number of epoxy groups and (meth)acryloyl groups is not particularly limited. For example, it can have one epoxy group and one (meth)acryloyl group, or it can have two or more of either or both. This (meth)acrylic acid modified epoxy compound has good compatibility with the aforementioned thermosetting compound (A). Therefore, as a photocurable compound (C), if it contains a (meth)acrylic acid modified epoxy compound, its compatibility becomes very good.

[0056] (Meth)acrylic acid modified epoxy compounds are, for example, compounds obtained by modifying a portion of the epoxy groups of a difunctional or higher epoxy compound with (meth)acrylic acid. The epoxy compound used in this modification only needs to have two or more epoxy groups within its molecule. From the viewpoint of suppressing excessively high crosslinking density and excessive reduction in the adhesive strength of the sealing material, difunctional epoxy compounds are preferred. Examples of difunctional 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-type epoxy compounds of the bisphenol A type and bisphenol F type are preferred from the viewpoint of easily improving the coatability of the resin composition (liquid crystal sealant). Compared with (meth)acrylic acid modified epoxy compounds derived from biphenyl ether-type epoxy compounds, (meth)acrylic acid modified epoxy compounds derived from bisphenol-type epoxy compounds have advantages such as excellent coatability.

[0057] The weight-average molecular weight of the (meth)acrylic acid modified epoxy compound, as determined by gel permeation chromatography (GPC), is preferably 300 to 1000.

[0058] When the photocurable compound (C) is either a (meth)acrylic acid compound or a (meth)acrylic acid modified epoxy compound, its (meth)acrylic acid equivalent is preferably 2500 or less, more preferably 1000 or less. If the (meth)acrylic acid equivalent is 1000 or less, the photocurability becomes good, and the moisture permeability of the obtained sealing material tends to be low. The (meth)acrylic acid equivalent is a value obtained by dividing the molecular weight of the (meth)acrylic acid compound or the (meth)acrylic acid modified epoxy compound by the number of (meth)acrylic acid groups in the molecule. The molecular weight is determined by gel permeation chromatography (GPC) and converted to polystyrene.

[0059] The total amount of the aforementioned photocurable compound (C) is preferably 30% by mass or more and 70% by mass or less, more preferably 40% by mass or more and 60% by mass or less, relative to the total amount of the resin composition. When the total amount of the photocurable compound (C) is within this range, the photocurability of the resin composition becomes better, and the liquid crystal contamination is easily reduced.

[0060] 1-4. Photopolymerization initiator (D)

[0061] The photopolymerization initiator (D) is not particularly limited to any compound capable of polymerizing the aforementioned photocurable compound (C) by light irradiation. The photopolymerization initiator (D) can be a self-destructive photopolymerization initiator or a hydrogen abstraction photopolymerization initiator. The resin composition may contain only one photopolymerization initiator (D) or may contain two or more.

[0062] Examples of self-destructive photopolymerization initiators include benzoyl dimethyl ketal compounds such as alkyl phenyl ketones (2,2-dimethoxy-1,2-diphenylethane-1-one (manufactured by BASF, IRGACURE 651)); α-aminoalkyl phenyl ketone compounds such as 2-methyl-2-morpholino(4-thiomethylphenyl)propane-1-one (manufactured by BASF, IRGACURE 907); and 1-hydroxycyclohexylphenyl ketone (manufactured by BASF, IRGACURE 651). α-hydroxyalkylphenyl ketone compounds such as 184); acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyl diphenylphosphine oxide; diacene compounds such as bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrolo-1-yl)-phenyl)titanium; diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, benzoylayl dimethyl ketal, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one, 4-(2-hydroxyethoxy)phenyl Acetophenone compounds such as 2-(2-hydroxy-2-propyl)one, 1-hydroxycyclohexylphenyl ketone, 2-methyl-2-morpholino(4-thiomethylphenyl)propane-1-one, and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone; benzoyl ester compounds such as methyl benzoate; 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-benzoyl oxime)] (manufactured by BASF, IRGACURE OXE01) and acetophenone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyl oxime) (manufactured by BASF, IRGACURE OXE02).

[0063] Examples of hydrogen-abstracting photopolymerization initiators include benzophenone, methyl 4-phenylbenzophenone, 4,4'-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyl diphenyl sulfide, acrylated benzophenone, 3,3',4,4'-tetra(tert-butylcarbonyl peroxide)benzophenone, 3,3'-dimethyl-4-methoxybenzophenone, and other benzophenone-based compounds; thioxanthones, 2-chlorothioxanthones (manufactured by Tokyo Chemical Industry Co., Ltd.), 1-chloro-4-propoxythioxanthones, 1-chloro-4-ethoxythioxanthones (manufactured by Lambson Limited, Speedcure CPTX), 2-isopropyloxanthones (manufactured by Lambson Limited, Speedcure ITX), 4-isopropylthioxanthones, 2,4-dimethylthioxanthones, and 2,4-diethylthioxanthones (Lambson...). The company manufactures the following compounds: Speedcure DETX, 2,4-dichlorothiazanthraquinone, and other thioxanthraquinone compounds; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-hydroxyanthraquinone (manufactured by Tokyo Chemical Industry Co., Ltd.), 2,6-dihydroxyanthraquinone (manufactured by Tokyo Chemical Industry Co., Ltd.), 2-hydroxymethylanthraquinone (manufactured by Pure Chemical Industries Co., Ltd.), and other anthraquinone compounds; as well as benzoyl compounds.

[0064] 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 higher is preferred. More preferably, it absorbs light in the visible light region, and particularly preferably, it absorbs light with a wavelength of 360 nm to 430 nm. If the photopolymerization initiator (D) has an absorption wavelength within this range, the resin composition can be cured by visible light irradiation, greatly reducing the impact on liquid crystal materials, etc. Furthermore, in this specification, the term "visible light region" is defined as the range of wavelengths from 360 nm to 780 nm.

[0065] Examples of photopolymerization initiators (D) that absorb light with a wavelength of 360 nm or greater include alkyl phenyl ketone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, titanoceramsite-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.

[0066] Furthermore, 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 infrared (IR) measurements.

[0067] The molecular weight of the photopolymerization initiator (D) is preferably 200 or more and 5000 or less. 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 improved, and the photocurability of the resin composition becomes better. More preferably, the molecular weight of the photopolymerization initiator (D) is 230 or more and 3000 or less, and even more preferably, 230 or more and 1500 or less.

[0068] The molecular weight of the photopolymerization initiator (D) can be determined as the "relative molecular mass" of the molecular structure of the main peak detected by high performance liquid chromatography (HPLC).

[0069] Specifically, a sample solution is prepared by dissolving the photopolymerization initiator (D) in tetrahydrofuran (THF) and analyzed by high-performance liquid chromatography (HPLC). The percentage of the detected peak area (the ratio relative to the sum of the areas of all peaks) is then calculated to confirm the presence of a main peak. The main peak is the peak with the highest intensity (highest peak height) detected at a characteristic detection wavelength (e.g., 400 nm for thioxanthone compounds). The relative molecular mass corresponding to the peak apex of the detected main peak can be determined by liquid chromatography-mass spectrometry (LC / MS).

[0070] The amount of photopolymerization initiator (D) relative to the total amount of photocurable compound (C) 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. If 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 readily becomes good. On the other hand, if the content of photopolymerization initiator (D) is 10% by mass or less, when the resin composition is used as a liquid crystal sealant, the photopolymerization initiator (D) is difficult to dissolve into the liquid crystal.

[0071] 1-5. Inorganic fillers (E)

[0072] The resin composition may further include an inorganic filler (E). If the resin composition includes an inorganic filler (E), the hardness of the resin composition is likely to increase, and the moisture permeability is likely to decrease further. The resin composition may contain only one inorganic filler (E), or it may contain two or more.

[0073] Examples of inorganic fillers (E) include calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum silicate, zirconium silicate, iron oxide, titanium oxide, titanium nitride, aluminum oxide (other than those listed above), zinc oxide, silicon dioxide, potassium titanate, kaolin, talc, glass beads, sericite, activated clay, bentonite, aluminum nitride, and silicon nitride. Among these, silicon dioxide, aluminum oxide, or talc are preferred from the viewpoints of ease of acquisition and stability.

[0074] The inorganic filler (E) can be in a fixed shape such as spherical, plate-like, or needle-like, or it can be an amorphous shape. When the inorganic filler is spherical, the average primary particle size is preferably 1.5 μm or less. Furthermore, the specific surface area of ​​the inorganic filler is preferably 0.5 m². 2 / g or more and 20m 2 / g or less. The average primary particle size of the inorganic filler can be determined by laser diffraction as described in JIS Z8825 (2013). The specific surface area of ​​the filler can be determined by the BET method as described in JIS Z8830 (2013).

[0075] The amount of inorganic filler (E) in the resin composition is preferably 10 parts by mass or more, more preferably 13 parts by mass or more and 30 parts by mass or less, relative to 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, 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 obtained sealing material tends to decrease. However, if it is excessively high, the coatability of the resin composition decreases; therefore, the above-mentioned range is preferred.

[0076] 1-6. Silane coupling agents (F)

[0077] The resin composition may further include a silane coupling agent (F). If the resin composition includes a silane coupling agent (F), the adhesion strength of the resulting sealing material to the substrate and alignment film is more easily improved.

[0078] Examples of silane coupling agents include vinyltrimethoxysilane, γ-(meth)acryloyloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, etc.

[0079] 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. If the content of the silane coupling agent is within this range, as described above, the adhesion strength between the obtained sealing material and the substrate and the alignment film is more easily improved.

[0080] 1-7. Core-shell particles (G)

[0081] The resin composition may further comprise core-shell microparticles (G). Core-shell microparticles are microparticles comprising a core having desired physical properties and a shell covering the core. The shell enhances compatibility with other components or allows for partial reaction with other components. Furthermore, if the resin composition contains these core-shell microparticles (G), the liquid crystal contamination is reduced due to the absorption and expansion of surrounding material upon heating. The resin composition may contain only one type of core-shell microparticle (G) or may contain two or more types.

[0082] Examples of core-shell microparticles (G) include organic microparticles having an elastic core comprising conjugated diene rubber and silicone rubber, and a shell comprising polymers such as (meth)acrylates, vinyl monomers, and epoxy monomers.

[0083] Another example of core-shell microparticles (G) includes microparticles having a core composed of inorganic particles and a shell composed of a polymer layer covering the core, and having functional groups containing carbon-carbon double bonds on the surface. Examples of carbon-carbon double bond functional groups in these core-shell microparticles include vinyl, allyl, acrylate, and methacrylate groups. Furthermore, examples of the core in these core-shell microparticles include particles similar to those in the inorganic filler (E) described above. From the viewpoint of excellent thermal stability, silica particles are preferred.

[0084] The average primary particle size of the core-shell microparticles (G) is preferably 0.1 μm to 1.0 μm, more preferably 0.2 μm to 0.8 μm, and even more preferably 0.3 μm to 0.5 μm. The average primary particle size of the core-shell microparticles (G) can be determined by microscopy. Specifically, it can be determined by image analysis using an electron microscope. More specifically, image analysis of the liquid crystal sealant is performed to screen out 50 organic fillers with a particle size of less than 1 μm, and the average value of the particle size measured is taken as the average particle size.

[0085] The amount of core-shell microparticles (G) relative to the total amount of the resin composition is preferably 1% by mass or more and 12% by mass or less, more preferably 5% by mass or more and 10% by mass or less. If the content of core-shell microparticles (G) is within this range, it is easy to further adjust the physical properties of the obtained sealing material to the desired range.

[0086] 1-8. Other ingredients

[0087] The resin composition of the present invention may further include various additives as needed. Examples of various additives include thermal free radical polymerization initiators, ion traps, ion exchangers, leveling agents, pigments, dyes, sensitizers, plasticizers, and defoamers.

[0088] Furthermore, the resin composition may also include spacers or the like for adjusting the gaps of the liquid crystal display panel.

[0089] The total amount of other components is preferably 1% by mass or more and 50% by mass or less relative to the total amount of the resin composition, more preferably 1% by mass or more and 25% by mass or less. If 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 compromised.

[0090] 1-9. Physical properties of the resin composition

[0091] Regarding the following film: the resin composition of the present invention is coated to a thickness of 100 μm, with a cumulative light intensity of 3000 mJ / cm. 2 A film cured by irradiation with light of wavelengths above 370 nm and below 450 nm, followed by heating at 120°C for 1 hour, has a moisture permeability of less than 100 g / m³ at 60°C and 90% Rh, as measured by JIS Z0208:1976, after 24 hours at 90% Rh. 2 The preferred moisture permeability is 90 g / m³. 2 The preferred value is 85g / m 2 The following applies if the moisture permeability under the above conditions is less than 100 g / m². 2 This allows for the long-term stable use of the liquid crystal display panel. Furthermore, in the moisture permeability measurement, an aluminum cup was made from the film cured under the aforementioned curing conditions and placed in a high-temperature, high-humidity bath at 60°C and 90% RH. Then, based on the mass before and after standing in the high-temperature, high-humidity bath, the moisture permeability was calculated using the following formula.

[0092] Moisture permeability (g / m 2 •100μm•24h)=[Weight of aluminum cup after 24 hours (g) - Weight of aluminum cup before 24 hours (g)] / Membrane area (m²) 2 )

[0093] On the other hand, the viscosity of the resin composition at 25°C and 2.5 rpm using an E-type viscometer is preferably 200 Pa·s to 450 Pa·s, more preferably 250 Pa·s to 400 Pa·s. If the viscosity is within the above range, the resin composition can be easily applied using a dispenser or the like.

[0094] Here, the resin composition can be used as a liquid crystal sealant as described above. The liquid crystal sealant may contain only the above-described resin composition, or it may be a resin composition that has been further mixed with other components as needed.

[0095] This liquid crystal sealant is primarily used as a sealant for liquid crystal display panels, but it can also be used as a sealant for display elements other than liquid crystal display panels, such as organic electroluminescence (EL) elements or light-emitting diode (LED) elements.

[0096] 2. Liquid crystal display panel and its manufacturing method

[0097] (Structure of a liquid crystal display panel)

[0098] The liquid crystal display panel of the present invention comprises: 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-mentioned resin composition (liquid crystal sealant).

[0099] Both substrates are transparent. The transparent substrates can be made of inorganic materials such as glass, or plastics such as polycarbonate, polyethylene terephthalate, polyethersulfone, and polymethyl methacrylate (PMMA). Matrix-shaped thin film transistors (TFTs), color filters, black matrices, etc., can also be disposed on the surface of each substrate.

[0100] In addition, an alignment film is disposed on the inner side (liquid crystal layer side) of each substrate. There are no particular limitations on the type of alignment film, including films formed from known organic or inorganic alignment agents. The alignment film can be disposed in a manner that covers approximately 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 can be disposed in a manner that covers only a portion of the substrate, or it can be disposed with a gap between the end of the alignment film and the end of the substrate.

[0101] Furthermore, the liquid crystal layer can be any layer composed of liquid crystal material sandwiched between the alignment films, and there are no particular limitations on the type of liquid crystal material.

[0102] The sealing material is a frame-shaped structure arranged to surround the aforementioned liquid crystal layer. In the liquid crystal display panel of the present invention, this sealing material can be arranged to be sandwiched within an alignment film.

[0103] As mentioned above, conventional sealing materials often fail to adequately improve the adhesion strength to the alignment film. However, by using the aforementioned resin composition, even when the sealing material is fabricated on the alignment film, the adhesion strength between the alignment film and the sealing material can be improved. Therefore, the aforementioned resin composition (liquid crystal sealant) is very useful in configurations where the bezel of a liquid crystal display panel is narrowed.

[0104] (Manufacturing method of liquid crystal display panel)

[0105] Liquid crystal display panels can be manufactured using the liquid crystal sealant of this invention. While liquid crystal display panel manufacturing methods typically include liquid crystal dispensing and liquid crystal injection processes, the liquid crystal display panels of this invention are preferably manufactured using the liquid crystal dispensing process.

[0106] The manufacturing method of a liquid crystal display panel using liquid crystal dispensing technology includes the following steps:

[0107] 1) The process of preparing two substrates with alignment films and an alignment film;

[0108] 2) The process of coating the liquid crystal sealant (resin composition) onto the surface of one of the substrates with an alignment film and forming a frame pattern.

[0109] 3) A process of depositing liquid crystal onto the inside of the frame pattern of one substrate with an alignment film or onto another substrate with an alignment film while the frame pattern is not cured.

[0110] 4) The process of overlapping one substrate with an alignment film with another substrate with an alignment film through a frame pattern; and

[0111] 5) The process of curing the frame pattern.

[0112] In step 2), the area where the liquid crystal sealant (resin composition) is applied is appropriately selected based on the desired structure of the liquid crystal display panel. For example, when the sealant is placed on an alignment film, the liquid crystal sealant (resin composition) is applied to the alignment film. The method of applying the liquid crystal sealant (resin composition) is not particularly limited as long as it allows the liquid crystal sealant (resin composition) to be applied to the desired width; for example, it can be applied using a dispenser or the like.

[0113] On the other hand, in step 3), the so-called uncured state of the frame pattern refers to the state where the curing reaction of the liquid crystal sealant has not reached the gelation point. Therefore, in step 3), in order to suppress the dissolution of the liquid crystal sealant in the liquid crystal, the frame pattern can also be semi-cured by light irradiation or heating. In addition, when liquid crystal is dropped onto another substrate with an alignment film in step 3), in step 4), when the two substrates with alignment films are overlapped, the liquid crystal is dropped onto the inside of the frame pattern.

[0114] In step 5), it is preferable to perform curing by heat after curing by light irradiation. By first performing curing by light irradiation, the liquid crystal sealant can be cured in a short time, thus suppressing dissolution in the liquid crystal. Furthermore, by combining curing by light irradiation with curing by heat, damage to the liquid crystal layer caused by light can be reduced compared to curing by light irradiation alone.

[0115] The irradiated light can be appropriately selected based on the type of photopolymerization initiator (D) in the aforementioned liquid crystal sealant (resin composition), but is preferably light in the visible light region, for example, light with a wavelength of 370 nm to 450 nm. Light at these wavelengths causes relatively little damage to the liquid crystal material and the driving electrode. Known light sources emitting ultraviolet or visible light can be used for irradiation. When irradiating with visible light, high-pressure mercury lamps, low-pressure mercury lamps, metal halide lamps, xenon lamps, fluorescent lamps, etc., can be used.

[0116] The light irradiation energy only needs to be sufficient to cure the photocurable compound (C). The curing time also depends on the composition of the liquid crystal sealant, but is, for example, around 10 minutes.

[0117] The curing temperature also depends on the composition of the liquid crystal sealant, but for example, it is 120°C and the curing time is about 2 hours.

[0118] Example

[0119] The present invention will now be described in detail with reference to the embodiments, but the scope of the present invention is not limited to the embodiments described herein.

[0120] 1. Preparation of materials

[0121] (Thermosetting compound (A))

[0122] • Carboxyl-modified acrylonitrile-butadiene rubber modified bisphenol A type epoxy resin (TSR-601, manufactured by DIC, epoxy equivalent 450-500, molecular weight: 948)

[0123] • Bisphenol A type propylene oxide (PO) modified epoxy resin (EP-4003S, manufactured by ADEKA, epoxy equivalent 470, molecular weight: 940)

[0124] • Epoxy polybutadiene (PB4700, manufactured by Daicel, epoxy equivalent 165, number average molecular weight: 3000)

[0125] (Potential thermosetting agent (B))

[0126] • Polyamine-based heat-latent curing agent (EH-4357S, manufactured by ADEKA, melting point: 80℃)

[0127] • Imidazole-based heat-latent curing agent (EH-4344S, manufactured by ADEKA, softening point: 110℃)

[0128] • Diacylhydrazide-based heat latent curing agent (ADH, manufactured by Nippon Fine Chemicals Co., Ltd., melting point: 180°C)

[0129] (Photocurable compound (C))

[0130] • Difunctional acrylic compounds (Ebecryl 3700, manufactured by Daicel-Allnex)

[0131] • Acrylic-modified epoxy resin (manufactured by Neo Chemical, BEAM-50, methacrylic acid modification ratio: 50%)

[0132] • Monofunctional acrylic resin (HOP-A, manufactured by Kyoei Chemical Co., Ltd.)

[0133] • Difunctional polybutadiene urethane acrylic resin (TE-2000, manufactured by Nippon Soda Co., Ltd., acrylic equivalent: 2000, number average molecular weight: 4000)

[0134] (Photopolymerization initiator (D))

[0135] • Oxime esters (OXE-02, manufactured by BASF)

[0136] • α-Aminoketone compounds (visible light compliant, Omnipol-910, manufactured by IGM)

[0137] • Thioxanthone-based (supports visible light, photopolymerization initiator prepared in Synthesis Example 1 below)

[0138] • Anthraquinone-based (supports visible light, photopolymerization initiator prepared in Synthesis Example 2 below)

[0139] (Synthesis example 1)

[0140] 5.00 g (1.74 × 10⁻⁶) of 2-(2-hydroxyethylthio)-thioxanthracene-9-one, synthesized by a known method, was added to a four-necked flask equipped with a stirrer, nitrogen inlet tube, reflux cooling tube, and thermometer. -2 A mixture of 50 g of toluene and 10 g of hexamethylene diisocyanate urea ester modifier (Mitsui Chemicals, Takenate D-178NL, isocyanate equivalent 216.1 g / eq) was added dropwise over 30 minutes. The mixture was stirred at 80°C for 3 hours under a nitrogen atmosphere. After the reaction was complete, the four-necked flask was cooled at room temperature, and the solid component was separated. The recovered solid component was thoroughly dried in an oven to obtain a thioxanthone-based photopolymerization initiator.

[0141] (Synthesis example 2)

[0142] Add 5.0 g (1.74 × 10⁻⁶) of 2-(2-hydroxyethylthio)-9,10-anthraquinone to a four-necked flask equipped with a stirrer, nitrogen inlet tube, reflux cooling tube, and thermometer. -2 A mixture of 1.98 g of hexamethylene diisocyanate urea ester modifier (Mitsui Chemicals, Takenate D-178NL, isocyanate equivalent 216.1 g / eq) and 10 g of toluene was stirred at 80 °C, followed by the addition of one drop of dibutyltin as a catalyst. Then, over 30 minutes, a solution containing 3.98 g of hexamethylene diisocyanate urea ester modifier dissolved in 10 g of toluene was added dropwise, and the mixture was stirred directly 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 crystals were separated. The obtained crystals were mixed again with toluene and stirred at 100 °C for 1 hour, then cooled again to remove impurities. The recovered crystals were thoroughly dried in an oven to obtain an anthraquinone-based photopolymerization initiator.

[0143] (Inorganic filler (E))

[0144] • Silica particles (SO-Cl, manufactured by Admatechs)

[0145] • Alumina particles (DAW-01, manufactured by Denka)

[0146] (Silane coupling agent (F))

[0147] • Silane coupling agent (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0148] (Core-shell particles (G))

[0149] • Core-shell polymer (F351, manufactured by Aica Industries)

[0150] 2. Preparation of resin composition

[0151] (Example 1)

[0152] A resin composition was obtained by mixing thermosetting compound (A) (CTBN (carboxyl-terminated liquid nitrile rubber) modified bisphenol A type epoxy compound), latent thermosetting agent (B), photocurable compound (C), photopolymerization initiator (D), inorganic filler (E), core-shell microparticles (F), and silane coupling agent (G) in the mass ratios shown in Table 1 using a three-roll mill. In this embodiment, it is used as a sealant.

[0153] (Examples 2 to 7 and Reference Examples 1 to 5)

[0154] The resin composition was prepared in the same manner as in Example 1, except that the composition was changed to that shown in Table 1.

[0155] (Confirmation of moisture permeability)

[0156] The moisture permeability of each of the above resin compositions was confirmed according to the following steps. A release film was placed on a rectangular glass plate. Then, a 100 μm thick PET (polyethylene terephthalate) film (spacer) was placed on the glass plate to surround the release film. Next, the resin compositions prepared in the examples and reference examples were coated onto the release film. Then, the release film and the glass plate were further placed sequentially on the resin composition, and the four sides were fixed using a clamp to hold the two glass plates together. Then, the cumulative light intensity was measured to be 3000 mJ / cm². 2 The resin composition was then irradiated with visible light (wavelength 360nm–450nm). It was then heated at 120°C for 1 hour to cure. Finally, the glass plate and release paper were removed to obtain a 100μm thick film (cured resin composition).

[0157] Using the obtained 100 μm membrane, an aluminum cup was prepared according to the method of JIS Z0208:1976, and placed in a high-temperature and high-humidity bath at 60°C and 90% RH for 24 h. Then, based on the mass before and after placement in the high-temperature and high-humidity bath, the moisture permeability was calculated using the following formula.

[0158] Moisture permeability (g / m 2 •100μm•24h)=[Weight of aluminum cup after 24 hours (g) - Weight of aluminum cup before 24 hours (g)] / Membrane area (m²) 2 )

[0159] Based on the calculated moisture permeability, the moisture resistance is evaluated according to the following criteria.

[0160] 3. Evaluation

[0161] The bond strength of the cured resin compositions was evaluated using the following methods. The results are shown in Table 1.

[0162] Compared to 100 parts by weight of the resin composition in each embodiment and reference example, 2 parts by weight of polymer beads (manufactured by Sekisui Chemicals Co., Ltd.: Micropearl SP) with an average particle size of 5 μm were added, and the polymer beads were dispersed in the resin composition using a planetary stirring device. Next, on the center of a 25 mm × 45 mm glass substrate (EAGLE XG, manufactured by Corning) pre-formed with a transparent electrode ITO (indium tin oxide) and an alignment film NRB-W876 (manufactured by Nissan Chemical Co., Ltd.), a screen printing plate was used to apply the resin composition containing the dispersed polymer beads in such a way that the diameter of the circle after lamination is approximately 3.5 mm, with a thickness of 5 μm, thereby forming a sealing pattern. Then, other glass substrates were laminated under atmospheric pressure, perpendicular to the glass substrate with the sealing pattern formed. Finally, the cumulative light intensity was set to 3000 mJ / cm². 2 The resin composition was irradiated with visible light (wavelength 370nm~450nm) and then heated at 120°C for 1 hour to cure, thereby obtaining a test piece.

[0163] A pressure testing machine (Model 210, Intesco) was used to vertically press a 0.5 mm section of the test piece from the center end of the short side of the glass towards the center at a speed of 37.5 mm / min, and the stress upon peeling of the seal was measured. This stress value was taken as the adhesive strength. The adhesion was evaluated based on the following criteria.

[0164] ○: Cases above 1.1 N / mm

[0165] △: Cases less than 1.1 N / mm but greater than 1.0 N / mm ×: Cases less than 1.0 N / mm

[0166] [Table 1]

[0167]

[0168] As shown in Table 1 above, by combining a thermosetting compound (A) containing a rubber-modified epoxy compound (a), a potential thermosetting agent (B) with a melting point below 110°C, a photocurable compound (C), and a photopolymerization initiator (D), it is possible to manufacture a product with a moisture permeability of less than 100 g / m³. 2 However, the sealing materials still have good bonding strength (Examples 1 to 7).

[0169] This application claims priority based on Japanese Patent Application No. 2023-053395, filed on March 29, 2023. All contents described in that application are incorporated herein by reference.

[0170] Industrial availability

[0171] According to the present invention, resin compositions capable of forming sealing materials with high adhesion strength and high moisture resistance to substrates, liquid crystal sealants containing the same, etc., can be obtained. Therefore, they are very useful for applications in various display devices.

Claims

1. A resin composition comprising: Thermosetting compound (A), Potential thermosetting agents (B) with a melting point below 110°C The photocurable compound (C) has intramolecular vinyl unsaturated double bonds, and Photopolymerization initiator (D), 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 within one molecule. In the resin composition Regarding the following film: the resin composition is coated to a thickness of 100 μm, with a cumulative light intensity of 3000 mJ / cm. 2 A film cured by irradiating light with wavelengths above 370 nm and below 450 nm and then heating at 120°C for 1 hour has a moisture permeability of less than 100 g / m³ at 60°C and 90% RH for 24 hours, as measured by JIS Z0208:1976. 2 .

2. The resin composition according to claim 1, wherein, The average molecular weight of the rubber-modified epoxy compound (a), as determined by gel permeation chromatography, is less than 2000.

3. The resin composition of claim 1, wherein, 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 the total of 100 parts by mass of the thermosetting compound (A) and the photocurable compound (C).

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

5. The resin composition of claim 1, further comprising an inorganic filler (E).

6. The resin composition of claim 5, wherein, The inorganic filler (E) is at least one selected from the group consisting of silica, alumina and talc.

7. The resin composition of claim 1, wherein, 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.

8. The resin composition of claim 1 further comprises a silane coupling agent (F).

9. The resin composition of claim 1 further comprises core-shell microparticles (G).

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

11. A liquid crystal sealant comprising the resin composition according to any one of claims 1 to 10.

12. The liquid crystal sealant as claimed in claim 11, wherein, The stress during the indentation test in the following tests is 1.0 N / mm or higher. Indentation test method: (i) Disperse 2 parts by weight of spacers with an average particle size of 5 μm in 100 parts by weight of the liquid crystal sealant using polymer beads (manufactured by Sekisui Chemicals Co., Ltd.: Micropearl SP); (ii) Prepare a pair of 25mm×45mm glass substrates (EAGLEXG, manufactured by Corning Incorporated) with transparent electrodes and alignment films formed of ITO. In the center of one of the glass substrates, the liquid crystal sealant with polymer beads dispersed thereon is coated with a diameter of 3.5mm and a thickness of 5μm. (iii) Overlap another glass substrate with the liquid crystal sealant in between; (iv) The cumulative light intensity is 3000 mJ / cm 2 The light with a wavelength of 360nm to 450nm was irradiated and cured at 120℃ for 1 hour. (v) The stress is measured when a portion of the other glass substrate is pressed into the center at a speed of 37.5 mm / min from the central end of the short side toward the center by a pressing tester.

13. A liquid crystal display panel, comprising: A pair of substrates; An alignment film is sandwiched between the pair of substrates; A liquid crystal layer, sandwiched between the pair of alignment films; and A sealing material is used to seal the liquid crystal layer. In the liquid crystal display panel, the sealing material is a cured product of the liquid crystal sealant according to claim 11.

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