JP7195228B2 - display sealant - Google Patents

Description

TECHNICAL FIELD The present invention relates to a display sealant that can be applied to flexible displays and curved displays. Since this sealant for displays can achieve both flexibility and low moisture permeability, it is particularly useful as a sealant for flexible displays and curved displays.
In addition, since the sealing agent having high flexibility like the present invention has excellent adhesion strength to adherends, it is also useful in applications where high adhesion strength is required.

The display sealant includes, for example, a liquid crystal display sealant, an organic EL display sealant, and a touch panel adhesive. What these materials have in common is that they are required to have properties such as excellent curability, low outgassing, and no damage to display elements.
Recently, curved displays and highly flexible displays have been developed and commercialized. Substrates used in such displays are flexible, such as plastic films, instead of conventional rigid substrates such as glass (Patent Document 1).
Against this background, sealants for displays are required to have properties such that they follow the bending of substrates and the like, that is, they are flexible even after curing.

In addition, a sealant having excellent flexibility is also advantageous in adhesive strength. For example, it is possible to reduce detachment and equipment damage due to impact. From this point of view as well, there is an increasing demand for imparting flexibility to sealants.

On the other hand, in order to increase the flexibility of the cured product, it is an effective means to lower the crosslink density of the cured product. However, when the crosslink density is lowered, the moisture permeability is usually deteriorated. It is considered that this is due to the infiltration of moisture from loose portions of the network. Therefore, in order to ensure low moisture permeability, it is necessary to realize contradictory characteristics, namely, increasing flexibility without lowering the crosslink density, or lowering the crosslink density but not deteriorating the moisture permeability.

Conventionally, from the viewpoint of improving adhesive strength, development of adhesives for display elements having flexibility has been carried out (Patent Document 2). However, a device with sufficient performance to adapt to the above flexible substrate has not yet been realized.

JP 2012-238005 A JP 2016-24240 A

TECHNICAL FIELD The present invention relates to a display sealant that can be applied to flexible displays and curved displays. More specifically, the present invention proposes a sealant for display using urethane (meth)acrylate composed of hydroxyl group-containing (meth)acrylate having an alicyclic structure.

As a result of intensive studies, the present inventors have found that a display sealant containing urethane (meth)acrylate composed of a hydroxyl group-containing (meth)acrylate having an alicyclic structure is excellent in flexibility and low moisture permeability. The inventors have arrived at the present invention.
In this specification, "(meth)acrylate" means "acrylate" and/or "methacrylate".

That is, the present invention relates to the following [1] to [10].
[1]
A sealant for displays containing (A) a urethane (meth)acrylate obtained by reacting (a) a polyol, (b) an organic polyisocyanate, and (c) a hydroxyl group-containing (meth)acrylate having an alicyclic structure.
[2]
The sealant for displays according to the preceding item [1], wherein the component (c) is cyclohexanedimethanol monoacrylate.
[3]
The display sealant according to the preceding item [1] or [2], wherein the component (a) is a polyester polyol.
[4]
The sealant for displays according to any one of the preceding items [1] to [3], further comprising (B) a curable compound.
[5]
The display sealant according to the preceding item [4], wherein the component (B) is a partial epoxy (meth)acrylate.
[6]
The display sealant according to any one of the preceding items [1] to [5], further comprising (C) an organic filler.
[7]
The display encapsulant according to the preceding item [6], wherein the component (C) is one or more organic fillers selected from the group consisting of urethane fine particles, acrylic fine particles, styrene fine particles, styrene olefin fine particles, and silicone fine particles. agent.
[8]
The sealant for displays according to any one of the preceding items [1] to [7], further comprising (D) a thermal radical polymerization initiator.
[9]
The display sealant according to any one of the preceding items [1] to [8], which is a liquid crystal sealant for a liquid crystal dropping method.
[10]
A liquid crystal display sealed with the liquid crystal sealant for liquid crystal dripping method according to the preceding item [9].

The sealant for displays of the present invention is useful as a sealant for displays because it is excellent in flexibility and low moisture permeability.

The sealant for display of the present invention comprises (A) urethane (meth)acrylate (hereinafter simply referred to as Also referred to as “component (A)”).
Component (A) has a flexible skeleton peculiar to a urethane structure, and by using a hydroxyl group-containing (meth)acrylate having an alicyclic structure, the cured product has the characteristics of flexibility and low moisture permeability, and is used in flexible displays. It can also follow bending.

In order to increase the flexibility of the cured product, it is effective to lower the crosslink density of the cured product. Therefore, it has been difficult to achieve both flexibility and low moisture permeability of the cured product.
Therefore, the present application conducted a study to find a material having a good balance between moisture permeability and elastic modulus. The elastic modulus of the sealant for display of the present invention is preferably 500 MPa or more and less than 1500 MPa. If the elastic modulus is less than 500 MPa, the bulk strength is low and the adhesive strength is low. On the other hand, when it exceeds 1500 MPa, it becomes difficult to follow the flexible display.
The moisture permeability is preferably less than 60 g/m ² ·24 hours, more preferably less than 50 g/m ² ·24 hours. This is to prevent water from entering in the humidity-resistant environment test.

Component (A) can be obtained by synthesizing (a) a polyol, (b) an organic polyisocyanate, and (c) a hydroxyl group-containing (meth)acrylate having an alicyclic structure in a conventional manner.
It is preferable to react 1.1 to 2.0 equivalents of isocyanate groups in component (b), particularly preferably 1.3 to 2.0 equivalents, with respect to 1 equivalent of hydroxyl groups in component (a). . The reaction temperature is preferably room temperature (25°C) to 100°C.
It is preferable to react 0.95 to 1.1 equivalents of hydroxyl groups in component (c) per equivalent of isocyanate groups in the reactants of components (a) and (b). The reaction temperature is preferably room temperature (25°C) to 100°C.

(a) Specific examples of polyols include tricyclodecanedimethanol, hydrogenated polybutadiene polyol, dimer diol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, and 1,4-butanediol. , neopentyl glycol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,14-tetradecanediol, 1,16 -hexadecanediol, 1,18-octadecanediol, 1,20-icosanediol, 1-methyl-1,8-octanediol, 2-methyl-1,8-octanediol, 3-methyl-1,5-pentane Diol, 2,4-diethyl-1,5-pentanediol, cyclohexane-1,4-dimethanol, polyethylene glycol, polypropylene glycol, bisphenol A poly(n≈2-20) ethoxydiol, bisphenol A poly(n≈2 ~20) Diols (a-1) such as propoxydiol, these diols (a-1) and dibasic acids or their anhydrides (e.g. succinic acid, adipic acid, azelaic acid, dimer acid, isophthalic acid, terephthalic acid, phthalic acid Examples include polyester diol (a-2) which is a reaction product with an acid or an anhydride thereof. Preferred are tricyclodecanedimethanol, dimer diol, 1,9-nonanediol, 3-methyl-1,5-pentanediol and polyester diols thereof.
Component (a) may be used alone or in combination of two or more.

(b) Specific examples of organic polyisocyanate include tolylene diisocyanate, isophorone diisocyanate, 1,6-hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-cyclohexyl Methane diisocyanate, xylylene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, trimethylhexamethylene diisocyanate, dimeryl diisocyanate, 1,5-naphthalene diisocyanate, 3,3'-dimethyl-4,4'-diphenylene diisocyanate etc. can be mentioned. Tolylene diisocyanate, isophorone diisocyanate, 1,6-hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate are preferred.

(c) The hydroxyl group-containing (meth)acrylate having an alicyclic structure is not particularly limited as long as it has both an alicyclic structure, a (meth)acrylic group and a hydroxyl group in the molecule. As a commercial product, for example, it is available as 1,4-cyclohexanedimethanol monoacrylate (trade name: CHDMMA, manufactured by Mitsubishi Chemical Corporation).

In the present application, a hydroxyl group-containing (meth)acrylate can be used in combination with component (c). Specific examples include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 1,4-butanediol (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, Examples include pentaerythritol tri(meth)acrylate, ε-caprolactone adduct of 2-hydroxyethyl(meth)acrylate, 2-hydroxy-3-phenyloxypropyl(meth)acrylate and the like. Preferred are 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate and polyethylene glycol mono(meth)acrylate.

The lower limit of the weight average molecular weight of component (A) in terms of polystyrene in GPC is preferably 1,000 or more, more preferably 2,000 or more, particularly preferably 3,000 or more, and most preferably 4,000 or more. Also, the upper limit is preferably 10,000 or less, more preferably 8,000 or less, particularly preferably 6,000 or less, and most preferably 5,000 or less. By being in the above range, the viscosity of the sealant for display is in an appropriate range while maintaining good flexibility and moisture permeability.

The content of component (A) is preferably 5 to 50% by mass, more preferably 10 to 30% by mass, based on the total amount of the sealant for display.

[(B) curable compound]
The sealant for displays of the present invention contains a curable compound (hereinafter also simply referred to as "component (B)") as component (B).
Component (B) is not particularly limited as long as it is a compound that is cured by light, heat, or the like, but is preferably (meth)acrylate or epoxy resin, such as (meth)acrylic ester, epoxy (meth)acrylate, or the like. is mentioned.

[(Meth)acrylate]
Specific examples of (meth)acrylic esters include N-acryloyloxyethylhexahydrophthalimide, acryloylmorpholine, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, cyclohexane-1,4-dimethanol mono (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, phenylpolyethoxy (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, o-phenylphenol monoethoxy (meth) ) acrylate, o-phenylphenol polyethoxy (meth) acrylate, p-cumylphenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, tribromophenyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, Dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di( meth)acrylate, tricyclodecanedimethanol (meth)acrylate, bisphenol A polyethoxydi(meth)acrylate, bisphenol A polypropoxydi(meth)acrylate, bisphenol F polyethoxydi(meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, tris(acryloxyethyl)isocyanurate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, tripentaerythritol hexa(meth)acrylate, Tripentaerythritol penta(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane polyethoxytri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, neopentyl glycol and hydroxypivalic acid ester diacrylate, Monomers such as the diacrylate of the ε-caprolactone adduct of an ester of neopentyl glycol and hydroxypivalic acid can be mentioned. N-acryloyloxyethylhexahydrophthalimide, phenoxyethyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate are preferred.
Epoxy (meth)acrylates are obtained by known methods by reacting epoxy resins with (meth)acrylic acid. The epoxy resin used as a raw material is not particularly limited, but is preferably a bifunctional or higher epoxy resin, such as resorcinol diglycidyl ether, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin. , phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol F novolak type epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy Resins, hydantoin-type epoxy resins, isocyanurate-type epoxy resins, phenol novolac-type epoxy resins having a triphenolmethane skeleton, other diglycidyl ethers of bifunctional phenols such as catechol and resorcinol, diglycidyl ethers of bifunctional alcohols compounds, and halides and hydrogenated products thereof. Among these, bisphenol A type epoxy resin and resorcinol diglycidyl ether are preferable from the viewpoint of liquid crystal contamination. Moreover, the ratio of the epoxy group and the (meth)acryloyl group is not limited, and is appropriately selected from the viewpoint of process compatibility.
In addition, a partial epoxy (meth)acrylate in which a part of the epoxy group is acryl-esterified is preferably used. In this case, the acrylic ratio is preferably about 30 to 70%.
(Meth)acrylates may be used alone or in combination of two or more. When the (meth)acrylate is used in the display sealant of the present invention, it is usually 10 to 80% by mass, preferably 20 to 70% by mass, based on the total amount of the display sealant.

[Epoxy resin]
As an aspect of the present invention, it is more preferable that the component (B) further contains an epoxy resin.
Although the epoxy resin is not particularly limited, a bifunctional or higher epoxy resin is preferable. Epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol F novolak type epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, hydantoin type Epoxy resins, isocyanurate-type epoxy resins, phenolic novolac-type epoxy resins having a triphenolmethane skeleton, diglycidyl-etherified products of bifunctional phenols such as catechol and resorcinol, diglycidyl-etherified products of bifunctional alcohols, and these Halides and hydrogenated products of Among these, bisphenol A type epoxy resin and resorcinol diglycidyl ether are preferable from the viewpoint of liquid crystal contamination.
Epoxy resins may be used alone or in combination of two or more. When an epoxy resin is used in the display sealant of the present invention, it is usually 5 to 50% by mass, preferably 5 to 30% by mass, based on the total amount of the display sealant.

[(C) organic filler]
The sealant for displays of the present invention may contain an organic filler (hereinafter also simply referred to as "component (C)") as component (C). Examples of the organic filler include urethane fine particles, acrylic fine particles, styrene fine particles, styrene olefin fine particles and silicone fine particles. KMP-594, KMP-597, KMP-598 (manufactured by Shin-Etsu Chemical Co., Ltd.), Torayfil ^RTM E-5500, 9701 and EP-2001 (manufactured by Dow Corning Toray Co., Ltd.) are preferred as the fine silicone particles, and JB- 800T, HB-800BK (Neagari Kogyo Co., Ltd.), Lavalon ^RTM T320C, T331C, SJ4400, SJ5400, SJ6400, SJ4300C, SJ5300C, and SJ6300C (manufactured by Mitsubishi Chemical) are preferable as styrene fine particles, and Septon ^RTM SEPS2004, as styrene olefin fine particles. SEPS2063 is preferred.
These organic fillers may be used alone or in combination of two or more. Moreover, it is good also as a core shell structure using 2 or more types. Among these, acrylic fine particles and silicone fine particles are preferred.
When the acrylic fine particles are used, it is preferable that the acrylic rubber has a core-shell structure composed of two kinds of acrylic rubbers, and particularly preferably, the core layer is n-butyl acrylate and the shell layer is methyl methacrylate. This is marketed by Aica Kogyo Co., Ltd. as Zephiac ^RTM F-351.
Examples of the fine silicone particles include organopolysiloxane crosslinked powders and linear dimethylpolysiloxane crosslinked powders. Composite silicone rubbers include those obtained by coating the surface of the silicone rubber with a silicone resin (for example, polyorganosilsesquioxane resin). Among these fine particles, particularly preferred are silicone rubber particles of linear dimethylpolysiloxane crosslinked powder or composite silicone rubber particles of silicone resin-coated linear dimethylpolysiloxane crosslinked powder. These things may be used independently and may use 2 or more types together. Further, preferably, the shape of the rubber powder is spherical so that the increase in viscosity after addition is small. When component (C) is used in the display sealant of the present invention, it is usually 5 to 50% by mass, preferably 5 to 40% by mass, based on the total amount of the display sealant.

[(D) Thermal radical polymerization initiator]
The sealant for displays of the present invention can improve the curing speed and curability by containing (D) a thermal radical polymerization initiator (hereinafter also simply referred to as "component (D)").
The thermal radical polymerization initiator is not particularly limited as long as it is a compound that generates radicals by heating and initiates a chain polymerization reaction, but organic peroxides, azo compounds, benzoin compounds, benzoin ether compounds, acetophenone compounds, benzopinacol, etc. benzopinacol is preferably used. For example, organic peroxides include Kayamec ^RTM A, M, R, L, LH, SP-30C, Perkadox CH-50L, BC-FF, Kadox B-40ES, Perkadox 14, Trigonox ^RTM 22-70E, 23-C70, 121, 121-50E, 121-LS50E, 21-LS50E, 42, 42LS, Kayaester ^RTM P-70, TMPO-70, CND-C70, OO-50E, AN, Kayabutyl ^RTM B, Parkadox 16 , Kayacarbon ^RTM BIC-75, AIC-75 (manufactured by Kayaku Akzo Co., Ltd.), Permek ^RTM N, H, S, F, D, G, Perhexa ^RTM H, HC, TMH, C, V, 22, MC, Percure ^RTM AH, AL, HB, Perbutyl ^RTM H, C, ND, L, Permyl ^RTM H, D, Perroyl ^RTM IB, IPP, Perocta ^RTM ND (manufactured by NOF Corporation) and the like are commercially available.

As azo compounds, VA-044, 086, V-070, VPE-0201, VSP-1001 (manufactured by Wako Pure Chemical Industries, Ltd.) and the like are commercially available.

The content of component (D) is preferably 0.0001 to 10% by mass, more preferably 0.0005 to 5% by mass, based on the total amount of the sealant for display of the present invention. 001 to 3% by weight is particularly preferred.

[(E) thermosetting agent]
The display sealant of the present invention can be improved in reactivity by adding a thermosetting agent (hereinafter also simply referred to as "component (E)") as component (E).
Examples of component (E) include compounds having a carboxy group bonded to an aromatic ring in the molecule, polyvalent amines, polyvalent phenols, organic acid hydrazides, and the like. However, it is not limited to these. For example, the aromatic hydrazides terephthalic acid dihydrazide, isophthalic acid dihydrazide, 2,6-naphthoic acid dihydrazide, 2,6-pyridinedihydrazide, 1,2,4-benzenetrihydrazide, 1,4,5,8-naphthoic acid Tetrahydrazide, pyromellitic acid tetrahydrazide and the like can be mentioned. Examples of aliphatic hydrazides include formhydrazide, acetohydrazide, propionic hydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, sebacic acid dihydrazide, 1 ,4-cyclohexanedihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, iminodiacetic acid dihydrazide, N,N'-hexamethylenebissemicarbazide, citric acid trihydrazide, nitriloacetic acid trihydrazide, cyclohexanetricarboxylic acid trihydrazide, 1,3-bis(hydrazide dihydrazide and tris(1-hydrazinocarbonylmethyl)isocyanurate having a hydantoin skeleton such as dinocarbonoethyl)-5-isopropylhydantoin, preferably a valine hydantoin skeleton (a skeleton in which a carbon atom of the hydantoin ring is substituted with an isopropyl group) , tris (2-hydrazinocarbonylethyl) isocyanurate, tris (1-hydrazinocarbonylethyl) isocyanurate, tris (3-hydrazinocarbonylpropyl) isocyanurate, bis (2-hydrazinocarbonylethyl) isocyanurate, etc. I can give From the balance between curing reactivity and latency, isophthalic acid dihydrazide, malonic acid dihydrazide, adipic acid dihydrazide, tris(1-hydrazinocarbonylmethyl)isocyanurate, tris(1-hydrazinocarbonylethyl)isocyanurate, tris( 2-hydrazinocarbonylethyl)isocyanurate, tris(3-hydrazinocarbonylpropyl)isocyanurate, particularly preferably tris(2-hydrazinocarbonylethyl)isocyanurate.
As component (E), it is preferable to use a compound having a carboxy group bonded to an aromatic ring in the molecule. -(Aminomethyl)benzoic acid, 2-mercaptonicotinic acid.
Component (E) may be used alone or in combination of two or more. When component (E) is used in the display sealant of the present invention, it is usually 0.1 to 10% by mass, preferably 0.1 to 5% by mass, based on the total amount of the display sealant.

[(F) Curing catalyst]
The sealant for displays of the present invention can further improve reactivity by adding a curing catalyst (hereinafter also simply referred to as "component (F)"). Examples of the curing catalyst include amines and imidazoles, and imidazoles are particularly preferred. Examples of imidazoles include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl-2 -methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 2,4-diamino-6 (2'-methylimidazole (1')) Ethyl-s-triazine, 2,4-diamino-6(2'-undecylimidazole (1')) ethyl-s-triazine, 2,4-diamino-6(2'-ethyl-4-methylimidazole (1 ')) ethyl-s-triazine, 2,4-diamino-6(2'-methylimidazole (1'))ethyl-s-triazine isocyanuric acid adduct, 2:3 adduct of 2-methylimidazole isocyanuric acid , 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-3,5-dihydroxymethylimidazole, 2-phenyl-4-hydroxymethyl-5-methylimidazole, 1-cyanoethyl-2-phenyl-3,5-dicyanoethoxy and methylimidazole.

[(G) photoradical polymerization initiator]
The sealant for displays of the present invention may contain a photoradical polymerization initiator (hereinafter also simply referred to as "component (G)") as component (G). The photoradical polymerization initiator is not particularly limited as long as it is a compound that generates radicals or acids upon irradiation with ultraviolet light or visible light and initiates a chain polymerization reaction. Examples include benzyl dimethyl ketal and 1-hydroxycyclohexyl phenyl ketone. , diethylthioxanthone, benzophenone, 2-ethylanthraquinone, 2-hydroxy-2-methylpropiophenone, 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propane, 2,4,6- trimethylbenzoyldiphenylphosphine oxide, camphorquinone, 9-fluorenone, diphenyldisulfide and the like. Specifically, Omnirad 651, 184, 2959, 127, 907, 369, 379EG, TPO, 819, 754 (all manufactured by IGM Resins), Irgacure ^RTM OXE01, OXE02, OXE03, OXE04, (all manufactured by BASF ), Seikuol ^RTM Z, BZ, BEE, BIP, and BBI (all manufactured by Seiko Kagaku Co., Ltd.). Among these, IRGACURE ^RTM OXE01, OXE02, OXE03 and OXE04, which are oxime ester initiators, are preferred.
Also, from the viewpoint of liquid crystal contamination, it is preferable to use those having a (meth)acrylic group in the molecule, such as 2-methacryloyloxyethyl isocyanate and 1-[4-(2-hydroxyethoxy)-phenyl]- Reaction products with 2-hydroxy-2methyl-1-propan-1-one are preferably used. This compound can be produced and obtained by the method described in International Publication No. 2006/027982.
When component (G) is used in the display sealant of the present invention, it is usually 0.001 to 3% by mass, preferably 0.002 to 2% by mass, based on the total amount of the display sealant.

[(H) inorganic filler]
The sealant for displays of the present invention can improve adhesive strength and moisture permeability by containing (H) an inorganic filler (hereinafter also simply referred to as "component (H)").
Inorganic fillers include silica, silicon carbide, silicon nitride, boron nitride, calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, alumina, magnesium oxide, zirconium oxide, aluminum hydroxide, magnesium hydroxide, Calcium silicate, aluminum silicate, lithium aluminum silicate, zirconium silicate, barium titanate, glass fiber, carbon fiber, molybdenum disulfide, asbestos, preferably fused silica, crystalline silica, silicon nitride, boron nitride, calcium carbonate, Barium sulfate, calcium sulfate, mica, talc, clay, alumina, aluminum hydroxide, calcium silicate and aluminum silicate can be mentioned, with silica, alumina and talc being preferred. These inorganic fillers may be used in combination of two or more.
If the average particle size of the inorganic filler is too large, it may cause defects such as failure to properly form a gap when the upper and lower glass substrates are bonded together when manufacturing a liquid crystal display cell with a narrow gap. 300 nm or less, and more preferably 300 nm or less. A preferred lower limit is about 10 nm, more preferably about 100 nm. The particle size can be measured with a laser diffraction/scattering particle size distribution analyzer (dry type) (manufactured by Seishin Enterprise Co., Ltd.; LMS-30).
When component (H) is used in the display sealant of the present invention, it is usually 5 to 50% by mass, preferably 5 to 40% by mass, based on the total amount of the display sealant. If the content of component (H) is less than 5% by mass, the adhesion strength to the glass substrate is lowered, and the moisture resistance reliability is also inferior, so that the adhesion strength after moisture absorption may be greatly reduced. Moreover, when the content of component (H) is more than 50% by mass, the amount of component (H) is too large, so that it may become difficult to collapse and the formation of gaps in the liquid crystal cell may not be possible.

Additives such as a silane coupling agent, a radical polymerization inhibitor, a pigment, a leveling agent, an antifoaming agent and a solvent can be blended with the sealant for display of the present invention, if necessary.

[Silane coupling agent]
Examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-(2-aminoethyl)3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)3-aminopropylmethyltrimethoxysilane, 3 -aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N-(2-(vinylbenzylamino)ethyl)3-aminopropyltrimethoxysilane hydrochloride, 3-methacryloxypropyltrimethoxysilane , 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane and the like. These silane coupling agents are sold as KBM series, KBE series, etc. by Shin-Etsu Chemical Co., Ltd., etc., and are readily available on the market. When a silane coupling agent is used in the display sealant of the present invention, it is preferably 0.05 to 3% by mass based on the total amount of the display sealant.

[Radical polymerization inhibitor]
The radical polymerization inhibitor is not particularly limited as long as it is a compound that reacts with radicals generated from a radical photopolymerization initiator, a thermal radical polymerization initiator, or the like to prevent polymerization. Hindered phenol type, nitroso type and the like can be used. Specifically, naphthoquinone, 2-hydroxynaphthoquinone, 2-methylnaphthoquinone, 2-methoxynaphthoquinone, 2,2,6,6-tetramethylpiperidine-1-oxyl, 2,2,6,6-tetramethyl-4 - hydroxypiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-methoxypiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-phenoxypiperidine-1-oxyl, hydroquinone, 2-methylhydroquinone, 2-methoxyhydroquinone, parabenzoquinone, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, 2,6-di-t-butylcresol, stearyl β-(3, 5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol) , 4,4′-butylidenebis(3-methyl-6-t-butylphenol), 3,9-bis[1,1-dimethyl-2-[β-(3-t-butyl-4-hydroxy-5-methyl phenyl)propionyloxy]ethyl], 2,4,8,10-tetraoxaspiro[5,5]undecane, tetrakis-[methylene-3-(3′,5′-di-t-butyl-4′-hydroxy phenylpropionate)methane], 1,3,5-tris(3′,5′-di-t-butyl-4′-hydroxybenzyl)-sec-triazine-2,4,6-(1H,3H,5H ) aluminum salt of trione, para-methoxyphenol, 4-methoxy-1-naphthol, thiodiphenylamine, N-nitrosophenylhydroxyamine, trade name Adekastab LA-81, tradename Adekastab LA-82 (manufactured by Adeka Co., Ltd.), and the like. but not limited to these. Of these, naphthoquinone-based, hydroquinone-based, nitroso-based, and piperazine-based radical polymerization inhibitors are preferred, and naphthoquinone, 2-hydroxynaphthoquinone, hydroquinone, 2,6-di-tert-butyl-p-cresol, Polystop 7300P (Hakuto Co., Ltd.) is more preferred, and Polystop 7300P (manufactured by Hakuto Co., Ltd.) is most preferred.
The content of the radical polymerization inhibitor is preferably 0.0001 to 1% by mass, more preferably 0.001 to 0.5% by mass, more preferably 0.01 to 0.2% by mass, based on the total amount of the sealant for display. Especially preferred.

An example of the method for obtaining the sealant for display of the present invention includes the following method. First, the components (B), (D) and (G) are heated and dissolved in the component (A), if necessary. Then, after cooling to room temperature, components (C), (E), (F), (H), inorganic fillers, silane coupling agents, antifoaming agents, leveling agents, solvents, etc. are added as necessary. The sealant for displays of the present invention can be produced by uniformly mixing the mixture using a mixing apparatus such as a three-roll mill, sand mill, ball mill, etc., and filtering through a metal mesh.

In addition, the display sealant of the present invention is very useful as an adhesive for liquid crystal display cells, particularly as a liquid crystal sealant. An example of a liquid crystal display cell in which the display sealant of the present invention is used as a liquid crystal sealant is shown below.

A liquid crystal display cell manufactured using the adhesive for a liquid crystal display cell of the present invention comprises a pair of substrates having predetermined electrodes formed on the substrates, arranged facing each other at a predetermined distance, and the periphery of the substrates being sealed with the liquid crystal sealing agent of the present invention. Liquid crystal is sealed in the gap between them. The type of liquid crystal to be enclosed is not particularly limited. Here, the substrate is composed of a combination of substrates, at least one of which is made of glass, quartz, plastic, silicon, or the like and has optical transparency. As a method for producing the liquid crystal sealing agent of the present invention, after adding a spacer (gap control material) such as glass fiber, the liquid crystal sealing agent is applied to one of the pair of substrates using a dispenser or a screen printer. After that, temporary curing is performed at 80 to 120° C., if necessary. After that, liquid crystal is dropped inside the weir of the liquid crystal sealant, and another glass substrate is overlapped in a vacuum to form a gap. After forming the gap, the liquid crystal display cell of the present invention can be obtained by curing at 90 to 130° C. for 30 minutes to 2 hours. When used as a photothermal combination type, the liquid crystal sealant portion is irradiated with ultraviolet rays by an ultraviolet irradiator for photocuring. The UV irradiation dose is preferably 500 to 6000 mJ/cm ² , more preferably 1000 to 4000 mJ/cm ² (measurement wavelength: 365 nm). After that, if necessary, the liquid crystal display cell of the present invention can be obtained by curing at 90 to 130° C. for 30 minutes to 2 hours. The thus-obtained liquid crystal display cell of the present invention is free from defective display due to liquid crystal contamination and is excellent in adhesiveness and humidity resistance reliability. Examples of spacers include glass fibers, silica beads, polymer beads, and the like. Although the diameter varies depending on the purpose, it is usually 2-8 μm, preferably 4-7 μm. The amount used is usually 0.1 to 4 parts by mass, preferably 0.5 to 2 parts by mass, and more preferably about 0.9 to 1.5 parts by mass based on 100 parts by mass of the liquid crystal sealing agent of the present invention. be.

The display sealant of the present invention is very suitable for use as an adhesive in fields requiring curability, adhesion to different adherends, and moist heat resistance reliability. For example, liquid crystal sealant, organic EL sealant, and touch panel adhesive.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the examples. Unless otherwise specified, "parts" and "%" in the text are based on mass.

[Synthesis Example 1: A-1]
A thermometer, a condenser, a flask equipped with a stirrer, 2-methyl-1,8-octanediol, 1,9-nonanediol and polyester polyol of adipic acid (O-1010 manufactured by Kuraray Co., Ltd., hydroxyl value 113 .7 mg KOH/g) and 49.89 g of toluene diisocyanate (Coronate T-100 manufactured by Tosoh Corporation, molecular weight 174.16) were charged and reacted at 80°C.
Then, 0.12 g of methoquinone (polymerization inhibitor), 0.02 g of dibutylhydroxytoluene (polymerization inhibitor), 58.50 g of cyclohexanedimethanol monoacrylate (molecular weight 198.3), and 0.07 g of dibutyltin dilaurate (catalyst) were added. Then, the mixture was stirred at 80° C. and reacted until the absorption spectrum (2280 cm ⁻¹ ) of the isocyanate group disappeared in the infrared absorption spectrum to obtain urethane acrylate A-1 having a weight average molecular weight of 4400. The weight average molecular weight was measured using a gel permeation chromatograph (converted to polystyrene standards) (the same applies hereinafter in the present invention).

[Synthesis Example 2: A-2]
A flask equipped with a thermometer, a condenser, and a stirrer was charged with 125.5 g of polyester polyol (P-1010 manufactured by Kuraray Co., Ltd., hydroxyl value: 115.4 mg KOH/g) of 3-methyl-1,5-pentanediol and adipic acid. 34 g, 6.28 g of tricyclodecanedimethanol (TCD alcohol DM manufactured by Celanese, molecular weight 196.3), and 39.26 g of trimethylhexanemethylene diisocyanate (VESTANAT TMDI manufactured by Eponic Japan, molecular weight 210.28) were charged, and 80 °C.
Then, 0.13 g of methoquinone (polymerization inhibitor), 0.03 g of dibutylhydroxytoluene (polymerization inhibitor), 65.35 g of cyclohexanedimethanol monoacrylate (molecular weight 198.3), and 0.08 g of dibutyltin dilaurate (catalyst) were added. Then, the mixture was stirred at 80° C. and reacted until the absorption spectrum (2280 cm ⁻¹ ) of the isocyanate group disappeared in the infrared absorption spectrum to obtain urethane acrylate A-2 having a weight average molecular weight of 5360.

[Synthesis Example 3: A-3]
In a flask equipped with a thermometer, a condenser, and a stirrer, 123.68 g of polyester polyol of dimer diol and dimer acid (PRILAST-3199 manufactured by CRODA, hydroxyl value 50.0 mg KOH/g), tricyclodecanedimethanol (Celanese) 2.84 g of isophorone diisocyanate (VESTANAT IPDI manufactured by Evonik, molecular weight of 222.3) and 64.24 g of isophorone diisocyanate (VESTANAT IPDI manufactured by Evonik, molecular weight of 222.3) were charged and reacted at 80°C.
Then, 0.12 g of methoquinone (polymerization inhibitor), 0.03 g of dibutylhydroxytoluene (polymerization inhibitor), 59.02 g of cyclohexanedimethanol monoacrylate (molecular weight 198.3), and 0.07 g of dibutyltin dilaurate (catalyst) were added. The mixture was added, stirred at 80° C., and reacted until the absorption spectrum (2280 cm ⁻¹ ) of the isocyanate group disappeared in the infrared absorption spectrum to obtain urethane acrylate A-3 having a weight average molecular weight of 4,850.

[Synthesis Example 4: O-1]
A flask equipped with a thermometer, a cooling tube and a stirrer was charged with 188 ml of polyester polyol of 3-methyl-1,5-pentanediol and adipic acid (P-1010 manufactured by Kuraray Co., Ltd., hydroxyl value: 115.4 mg KOH/g). 25 g and 85.47 g of isophorone diisocyanate (VESTANAT IPDI manufactured by Evonik, molecular weight 222.3) were charged and reacted at 80°C.
Then, 0.16 g of methoquinone (polymerization inhibitor), 0.03 g of dibutylhydroxytoluene (polymerization inhibitor), 45.99 g of 2-hydroxyacrylate (molecular weight 116.12), and 0.10 g of dibutyltin dilaurate (catalyst) are added. Then, the mixture was stirred at 80° C. and reacted until the absorption spectrum (2280 cm ⁻¹ ) of the isocyanate group disappeared in the infrared absorption spectrum to obtain urethane acrylate O-1 with a weight average molecular weight of 4450.

[Synthesis Example 5: O-2]
A thermometer, a condenser, a flask equipped with a stirrer, 2-methyl-1,8-octanediol, 1,9-nonanediol and polyester polyol of adipic acid (O-1010 manufactured by Kuraray Co., Ltd., hydroxyl value 113 .7 mg KOH / g) 142.31 g, tricyclodecanedimethanol (TCD alcohol DM manufactured by Celanese, molecular weight 196.3) 3.15 g, and trimethylhexanemethylene diisocyanate (VESTANAT TMDI manufactured by Eponic Japan, molecular weight 210.28) 67.29 g were charged and reacted at 80°C.
Then, 0.13 g of methoquinone (polymerization inhibitor), 0.03 g of dibutylhydroxytoluene (polymerization inhibitor), 38.27 g of 2-hydroxyacrylate (molecular weight 116.12), and 0.08 g of dibutyltin dilaurate (catalyst) are added. Then, the mixture was stirred at 80° C. and reacted until the absorption spectrum (2280 cm ⁻¹ ) of the isocyanate group disappeared in the infrared absorption spectrum to obtain urethane acrylate O-2 having a weight average molecular weight of 7670.

[Synthesis Example 6: O-3]
In a flask equipped with a thermometer, a condenser, and a stirrer, 136.95 g of polyester polyol of dimer diol and dimer acid (PRILAST-3199 manufactured by CRODA, hydroxyl value 50.0 mg KOH/g), tricyclodecanedimethanol (Celanese) 7.07 g of toluene diisocyanate (Coronate T-100, molecular weight: 174.16, manufactured by Tosoh Corporation) and 62.70 g of toluene diisocyanate were charged and reacted at 80°C.
Then, 0.12 g of methoquinone (polymerization inhibitor), 0.02 g of dibutylhydroxytoluene (polymerization inhibitor), 43.06 g of 2-hydroxyacrylate (molecular weight 116.12), and 0.07 g of dibutyltin dilaurate (catalyst) are added. Then, the mixture was stirred at 80° C. and reacted until the absorption spectrum (2280 cm ⁻¹ ) of the isocyanate group disappeared in the infrared absorption spectrum to obtain urethane acrylate O-3 having a weight average molecular weight of 8850.

[Synthesis Example 7: O-4]
A flask equipped with a thermometer, a condenser, and a stirrer was charged with 127.5 ml of polyester polyol (P-1010 manufactured by Kuraray Co., Ltd., hydroxyl value: 115.4 mg KOH/g) of 3-methyl-1,5-pentanediol and adipic acid. 72 g, 2.84 g of tricyclodecanedimethanol (TCD alcohol DM manufactured by Celanese Corporation, molecular weight 196.3), and 50.48 g of toluene diisocyanate (Coronate T-100 manufactured by Tosoh Corporation, molecular weight 174.16) were charged and heated to 80 ° C. reacted with
Then, 0.12 g of methoquinone (polymerization inhibitor), 0.02 g of dibutylhydroxytoluene (polymerization inhibitor), 68.74 g of caprolactone-modified hydroxyacrylate (molecular weight: 230.26), and 0.07 g of dibutyltin dilaurate (catalyst) were added. Then, the mixture was stirred at 80° C. and reacted until the absorption spectrum (2280 cm ⁻¹ ) of the isocyanate group disappeared in the infrared absorption spectrum to obtain urethane acrylate O-4 with a weight average molecular weight of 4000.

[Synthesis Example 8: O-5]
A thermometer, a condenser, a flask equipped with a stirrer, 2-methyl-1,8-octanediol, 1,9-nonanediol and polyester polyol of adipic acid (O-1010 manufactured by Kuraray Co., Ltd., hydroxyl value 113 .7 mg KOH / g) 112.95 g, tricyclodecanedimethanol (TCD alcohol DM manufactured by Celanese, molecular weight 196.3) 5.61 g, and isophorone diisocyanate (VESTANAT IPDI manufactured by Evonik, molecular weight 222.3) 63.49 g was charged and reacted at 80°C.
Then, 0.12 g of methoquinone (polymerization inhibitor), 0.02 g of dibutylhydroxytoluene (polymerization inhibitor), 67.73 g of caprolactone-modified hydroxyacrylate (molecular weight: 230.26), and 0.07 g of dibutyltin dilaurate (catalyst) were added. Then, the mixture was stirred at 80° C. and reacted until the absorption spectrum (2280 cm ⁻¹ ) of the isocyanate group disappeared in the infrared absorption spectrum to obtain urethane acrylate O-5 with a weight average molecular weight of 5010.

[Synthesis Example 9: O-6]
In a flask equipped with a thermometer, a condenser, and a stirrer, polyester polyol of dimer diol and dimer acid (CRODA PRILAST-3199, hydroxyl value 50.0 mg KOH / g) 128.68 g, trimethylhexanemethylene diisocyanate (Eponic Japan 56.91 g of VESTANAT TMDI (molecular weight: 210.28) manufactured by Co., Ltd. was charged and reacted at 80°C.
Then, 0.12 g of methoquinone (polymerization inhibitor), 0.02 g of dibutylhydroxytoluene (polymerization inhibitor), 64.18 g of caprolactone-modified hydroxyacrylate (molecular weight: 230.26), and 0.07 g of dibutyltin dilaurate (catalyst) were added. Then, the mixture was stirred at 80° C. and reacted until the absorption spectrum (2280 cm ⁻¹ ) of the isocyanate group disappeared in the infrared absorption spectrum to obtain urethane acrylate O-6 with a weight average molecular weight of 5010.

[Synthesis Example 10: O-7]
178.45 g of a polyester polyol of 3-methyl 1,5-pentanediol and sebacic acid (manufactured by Kuraray Co., Ltd. P-2050, hydroxyl value 56.8 mg KOH/g) was placed in a flask equipped with a thermometer, condenser, and stirrer. , 17.73 g of tricyclodecanedimethanol (TCD alcohol DM manufactured by Celanese, molecular weight 196.3) and 80.32 g of isophorone diisocyanate (VESTANAT IPDI manufactured by Evonik, molecular weight 222.3) were charged and reacted at 80 ° C. rice field.
Then, 0.16 g of methoquinone (polymerization inhibitor), 0.03 g of dibutylhydroxytoluene (polymerization inhibitor), 43.12 g of 2-hydroxyacrylate (molecular weight 116.12), and 0.10 g of dibutyltin dilaurate (catalyst) are added. Then, the mixture was stirred at 80° C. and reacted until the absorption spectrum (2280 cm ⁻¹ ) of the isocyanate group disappeared in the infrared absorption spectrum to obtain urethane acrylate O-7 having a weight average molecular weight of 6610.

[Synthesis Example 11]
100 parts (0.28 mol) of commercially available benzopinacol (manufactured by Tokyo Kasei) was dissolved in 350 parts of dimethylformaldehyde. 32 parts (0.4 mol) of pyridine as a base catalyst and 150 parts (0.58 mol) of BSTFA (manufactured by Shin-Etsu Chemical Co., Ltd.) as a silylating agent were added thereto, and the mixture was heated to 70° C. and stirred for 2 hours. The resulting reaction solution was cooled and 200 parts of water was added while stirring to precipitate the product and deactivate the unreacted silylating agent. After separating the precipitated product by filtration, it was thoroughly washed with water. The resulting product was then dissolved in acetone and recrystallized by adding water for purification. 105.6 parts of the desired 1,2-bis(trimethylsiloxy)-1,1,2,2-tetraphenylethane was obtained (yield 88.3%).

[Examples 1 to 3, Comparative Examples 1 to 7]
Components (A), (B), (D), (G), and (O) were heated and mixed at 90° C. in the proportions shown in Table 1 below, then cooled to room temperature, and components (C) and (E) were mixed. , (F), (H), and (O) were added, stirred, dispersed in a three-roll mill, and filtered through a metal mesh (635 mesh) to prepare a sealant for display.

[evaluation]
[Adhesion strength]
An alignment film liquid (RN2880 manufactured by Nissan Chemical Industries, Ltd.) was spin-coated on a glass substrate, calcined on a hot plate at 80° C. for 3 minutes, and baked in an oven at 230° C. for 30 minutes. Further, the substrate with the alignment film was irradiated with ultraviolet rays of 500 mJ/cm ² (measurement wavelength: 254 nm) using a UV irradiation machine, and baked in an oven at 230° C. for 30 minutes.
1 g of glass fiber of 5 μm as a spacer is added to 100 g of the sealant for displays produced in Examples and Comparative Examples, and mixed and stirred. On the glass substrate coated with the alignment film, this sealant for display was coated so as to reproduce a corner portion of 1 cm x 1 cm, and the opposing alignment film ^- coated substrates were bonded together. After being irradiated with ultraviolet rays having a wavelength of 365 nm, the film was placed in an oven and thermally cured at 130° C. for 40 minutes. The peeling adhesion strength of the orientation film-coated glass substrate was measured with a bond tester (manufactured by Seishin Shoji Co., Ltd.: SS-30WD) by pressing the corner portion.
Also, the adhesive strength measured on a glass substrate not coated with an alignment film was measured in the same manner.
The measurement results are evaluated based on the following criteria, and the results are shown in Table 1.
Adhesive strength 2.0 kg or more: ◎
Adhesive strength 1.8 kg or more and less than 2.0 kg: ○
Adhesion strength less than 1.8 kg: x

[Preparation of liquid crystal cell for evaluation]
An orientation film was applied to the substrate with the transparent electrode in the same manner as described above to prepare a substrate with the orientation film and the transparent electrode. A main seal and a dummy seal were dispensed so that the line width after bonding the obtained liquid crystal sealant to this substrate was 1 mm, and then microdroplets of liquid crystal (JC-5015LA; manufactured by JNC Co., Ltd.) were applied to the seal pattern. Dropped into the frame. Furthermore, an in-plane spacer (manufactured by Natoco Co., Ltd.: Natoco Spacer KSEB-525F; gap width after bonding: 5 μm) was dispersed on another substrate with an alignment film and a transparent electrode, and then heat-fixed, and then vacuumed using a bonding device. Inside, it was pasted with the previous substrate on which the liquid crystal had been dropped. After opening to the atmosphere and forming a gap, only the inside of the seal pattern frame was masked and irradiated with ultraviolet rays of 3000 mJ/cm ² by a UV irradiator. Created.

[Measurement of voltage holding ratio (VHR)]
An electrode was attached to the liquid crystal test cell for evaluation, and the voltage holding rate was measured under the conditions of an applied voltage of 5 V, a frequency of 1 Hz, and an atmosphere of 60° C. using a liquid crystal physical property measurement system (manufactured by Toyo Technica Co., Ltd.).
The measurement results are evaluated based on the following criteria, and the results are shown in Table 1.
Voltage holding rate 80% or more: ◎
Voltage retention rate 70% or more and less than 80%: ○
Voltage holding rate less than 70%: ×

[Moisture Permeability]
The display sealants produced in Examples and Comparative Examples were sandwiched between polyethylene terephthalate (PET) films to form a thin film with a thickness of 300 μm, which was irradiated with ultraviolet rays of 3000 mJ/cm ² (measurement wavelength: 365 nm) using a UV irradiation machine. After that, it was placed in an oven and thermally cured at 130° C. for 40 minutes. After curing, the PET film was peeled off to obtain a sample. The moisture permeability of the sample at 60° C. 90% was measured with a moisture permeability meter (L80-5000 manufactured by Lessy). The measurement results are evaluated based on the following criteria, and the results are shown in Table 1.
Moisture permeability less than 50 g/ ^m 2.24 hours: ◎
Moisture permeability 50 g/ ^m 2.24 hours or more and less than 60 g/ ^m 2.24 hours: ○
Moisture permeability 60 g/ ^m 2.24 hours or more: ×

[Elastic modulus]
The display sealants produced in Examples and Comparative Examples were sandwiched between polyethylene terephthalate (PET) films to form a thin film with a thickness of 100 μm, which was irradiated with ultraviolet rays of 3000 mJ/cm ² (measurement wavelength: 365 nm) using a UV irradiation machine. After that, it was placed in an oven and thermally cured at 130° C. for 40 minutes. After curing, the PET film was peeled off to obtain a sample. The tensile strength of the sample was measured using a Tensilon universal testing machine (RTG-1210, manufactured by A&D Co., Ltd.) at room temperature (22° C.) at a test speed of 5 mm/min.
The measurement results are evaluated based on the following criteria, and the results are shown in Table 1.
Elastic modulus 500 MPa or more and less than 1500 MPa: ○
Elastic modulus Less than 500 MPa or 1500 MPa or more: ×

From the results in Table 1, it was confirmed that the display sealant of the present invention has both flexibility and low moisture permeability, and is also excellent in adhesive strength and resistance to liquid crystal contamination.

The sealant for displays of the present invention has excellent adhesion strength to adherends and has both flexibility and low moisture permeability. It is useful as a sealant for shaped displays.

Claims (7)

(A) a urethane (meth)acrylate obtained by reacting (a) a polyol, (b) an organic polyisocyanate, and (c) a hydroxyl group-containing (meth)acrylate having an alicyclic structure, and (B) a curable compound A display sealant for
A sealant for a display, wherein the component (B) is a partial epoxy (meth)acrylate. 2. The sealant for displays according to claim 1, wherein said component (c) is cyclohexanedimethanol monoacrylate. 3. The display sealant according to claim 1, wherein the component (a) is a polyester polyol. 4. The display sealant according to any one of claims 1 to 3 , further comprising (C) an organic filler. 5. The display sealant according to any one of claims 1 to 4 , further comprising (D) a thermal radical polymerization initiator. The display sealant according to any one of claims 1 to 5 , which is a liquid crystal sealant for a liquid crystal dropping method. A liquid crystal display sealed with the liquid crystal sealant for liquid crystal dropping method according to claim 6 .