JP2019078785A - Sealant for display - Google Patents

Abstract

To provide a sealant for displays which is applicable even to a flexible display or a display of curved shape, more specifically a sealant for displays that satisfies specific properties, the sealant for displays exhibiting both flexibility and moisture permeability and especially useful as a sealant for a flexible display or a display of curved shape.SOLUTION: Provided is a sealant for displays, wherein the glass transition temperature of a cured substance as measured by a dynamic viscoelasticity measurement method is 90°C or higher, and the elasticity at 22°C as measured by a Tensilon universal testing machine is 2000 MPa or less.SELECTED DRAWING: None

Description

  The present invention relates to a sealing agent for a display that can be applied to a flexible display or a curved display. More particularly, the present invention relates to a sealing agent for display satisfying a specific relationship in glass transition temperature and elastic modulus. The display sealing agent is compatible with flexibility and low moisture permeability, and is particularly useful as a flexible display or a curved display sealing agent.

Examples of the display sealant include liquid crystal sealants, organic EL display sealants, and touch panel adhesives. Common to these materials is that they are required to have excellent curability, low outgassing and no damage to the display element.
In recent years, curved displays and flexible displays have been developed and commercialized. As a substrate used for such a display, a flexible substrate such as a plastic film is used instead of a rigid substrate such as a conventional glass (Patent Document 1).
From such a background, the sealant for display is required to have the property of following the deflection of a substrate or the like, that is, to be flexible even after curing.

  On the other hand, in order to enhance the flexibility of the cured product, it is an effective means to lower the crosslink density of the cured product. However, it is normal to deteriorate the moisture permeability as the crosslink density decreases. This is considered to be due to the infiltration of water from the loose part of the network. Therefore, in order to secure low moisture permeability, it is necessary to increase the flexibility without lowering the crosslinking density or to realize the contradictory characteristics of lowering the crosslinking density but not deteriorating the moisture permeability.

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

JP, 2012-238005, A JP, 2016-24240, A

  The present invention proposes a sealant that is flexible to the extent that it can be applied to a flexible display or a curved display, and is also excellent in low moisture permeability.

The inventors of the present invention, as a result of intensive studies, have found that a sealing agent for a display satisfying a specific relationship in glass transition temperature and elastic modulus is extremely excellent in flexibility and low moisture permeability, and has led to the present invention.
In the present specification, "(meth) acrylic" means "acrylic and / or methacrylic", and "(meth) acryloyl group" means "acryloyl and / or methacryloyl group". Moreover, "liquid crystal sealing agent for liquid crystal dropping method" may be described simply as "liquid crystal sealing agent" or "seal agent".

That is, the present invention
[1] A sealing agent for a display, wherein the glass transition temperature of the cured product measured by the dynamic viscoelasticity measurement method is 90 ° C. or more, and the elastic modulus at 22 ° C. measured by the Tentiron universal tester is 2000 MPa or less
[2] Component (A): The compound containing the same mass of bisphenol A epoxy methacrylate at 90 ° C. by heating and mixing, and leaving at 22 ° C. for 1 hour does not cause white turbidity or causes separation of the components. [1] The sealant for display according to
[3] The sealant for a display according to [2], wherein the component (A) is a liquid rubber,
[4] The sealant for a display according to the above [2] or [3], wherein the component (A) is a polybutadiene compound having an epoxy group in the molecule,
[5] The sealant for a display according to any one of [2] to [4], wherein the component (A) is a compound having a reactive double bond in the molecule,
[6] The sealant for a display according to any one of [2] to [5], wherein the number average molecular weight of the component (A) is 500 or more and 10000 or less.
[7] The sealant for a display according to any one of [1] to [6], further comprising a component (B) a curable compound,
[8] The sealant for a display according to the above [7], wherein the component (B) is a component (B-1) (meth) acrylic compound
[9] The sealant for a display according to the above [7], wherein the component (B) is a mixture of a component (B-1) (meth) acrylic compound and a component (B-2) epoxy compound,
[10] The sealant for a display according to the above item [8] or [9], wherein the component (B-1) is an epoxy (meth) acrylate,
[11] The sealant for a display according to any one of the above [1] to [10], further comprising a component (C) a thiol compound,
[12] The sealant for a display according to any one of [1] to [11], further comprising a component (D) an organic filler.
[13] The display according to the above [12], wherein the component (D) is one or more organic fillers selected from the group consisting of urethane particles, acryl particles, styrene particles, styrene olefin particles, and silicone particles. Sealant,
[14] The sealant for a display according to any one of [1] to [13], further comprising a component (E) an inorganic filler
[15] The sealant for a display according to any one of [1] to [14], further comprising a component (F) a silane coupling agent,
[16] The sealant for display according to any one of [1] to [15], further comprising a component (G) a thermosetting agent.
[17] The sealant for a display according to the above item [16], wherein the component (G) is an organic acid hydrazide compound,
[18] The sealant for a display according to any one of [1] to [17], further comprising a component (H) a photoradical polymerization initiator,
[19] The sealant for a display according to any one of [1] to [18], further comprising a component (I) a thermal radical polymerization initiator,
[20] A liquid crystal sealant using the sealant for a display according to any one of the above [1] to [19],
[21] A liquid crystal display cell bonded using the liquid crystal sealing agent according to the preceding item [20],
It is about

  The sealant for a display of the present invention is compatible with flexibility and low moisture permeability, and is particularly useful as a sealant for a flexible display or a curved display.

[Glass transition temperature of cured product measured by dynamic viscoelasticity measurement method is 90 ° C or higher]
The glass transition temperature (hereinafter, also simply referred to as “Tg”) of the cured product of the display sealing agent of the present invention is 90 ° C. or higher.
The measurement of the glass transition temperature was carried out by using a metal halide lamp (manufactured by Ushio Electric Co., Ltd.) on a liquid crystal sealing agent manufactured in Examples and Comparative Examples, sandwiched between polyethylene terephthalate (PET) films and made into thin films with a thickness of 100 μm. After curing by irradiation with ultraviolet light of 3000 mJ / cm ² (30 seconds at 100 mW / cm ² ), it was placed in an oven at 120 ° C. for 40 minutes to cure. Thereafter, the PET film was peeled off and the cured sealing agent film was cut into strips of 50 mm × 5 mm to obtain sample pieces. The sample piece was measured under the conditions of a frequency 10 Hz and a temperature elevation temperature of 2 ° C./min in a tension mode of a dynamic viscoelasticity measuring apparatus (DMS-6100: manufactured by SII Nano Technology Inc.). The temperature at which the loss coefficient Tan δ is obtained from the ratio of the loss elastic modulus to the storage elastic modulus (JIS K 7244-1) and the obtained loss coefficient Tan δ is the maximum value is taken as the glass transition temperature. In the present invention, the glass transition temperature is preferably 90 ° C. or more, more preferably 100 ° C. or more, and still more preferably 120 ° C. or more. The high glass transition temperature is because the change in mechanical properties is small and the reliability is excellent even in a high temperature environment.

[Elastic modulus at 22 ° C measured with Tensilon Universal Tester is 2000 MPa or less]
The elastic modulus at 22 ° C. of the cured product of the sealant for a display of the present invention is 2000 MPa or less.
The measurement of the glass transition temperature was carried out by using a metal halide lamp (manufactured by Ushio Electric Co., Ltd.) on a liquid crystal sealing agent manufactured in Examples and Comparative Examples, sandwiched between polyethylene terephthalate (PET) films and made into thin films with a thickness of 100 μm. After curing by irradiation with ultraviolet light of 3000 mJ / cm ² (30 seconds at 100 mW / cm ² ), it was placed in an oven at 120 ° C. for 40 minutes to cure. Thereafter, the PET film was peeled off and the cured sealant film was cut into a dumbbell-shaped test piece (total length 75 mm, overall width 10 mm, narrow parallel portion length 50 mm, width 5 mm) to obtain a sample piece. The obtained test piece was subjected to a tensile test at a test speed of 5 mm / min at room temperature (22 ° C.) using a TENSILON universal testing machine (RTG-1210, manufactured by A & D Co., Ltd.). The modulus of elasticity was calculated from the results of tensile stress and strain. The elastic modulus is a value showing flexibility along with a flexibility test described later, and is preferably 2000 MPa or less, more preferably 1500 MPa or less.

[(A) a compound which is mixed with the same mass of bisphenol A epoxy methacrylate at 90 ° C. by heating and left at 22 ° C. for 1 hour for causing no white turbidity or causing separation of components]
The sealing agent for a display of the present invention is mixed with the component (A): bisphenol A epoxy methacrylate of the same mass by heating at 90 ° C. and left at 22 ° C. for 1 hour to cause white turbidity or cause separation of the components. It is preferable to contain a non-compound (hereinafter, also simply referred to as "component (A)"). The same mass means that the mass of the compound is the same as that of the bisphenol A epoxy methacrylate. The heating and mixing time at 90 ° C. is preferably within 1 hour, more preferably within 30 minutes.
A method of realizing a high glass transition temperature and a low elastic modulus by using a compound incompatible with the curable resin (for example, the high glass transition temperature is not compatible with the low elastic modulus due to the cured product characteristics of the resin) Depending on the characteristics of the compound, there is a method to realize, but one of the features of the present invention is to realize a low elastic modulus without relying on such incompatible compounds, and as a result to achieve both flexibility and low moisture permeability. is there.
Here, as long as the bisphenol A epoxy methacrylate is obtained by methacrylic esterifying the epoxy group of the bisphenol A epoxy compound in an amount of 95 mol% or more, the polarity does not change significantly, and, for example, RE-310S (manufactured by Nippon Kayaku Co., Ltd. And 100 mol% of epoxy groups of YD 8125 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) can be tested with methacryl ester. Methacrylic esterification can be easily performed using a known method. The viscosity of the bisphenol A type epoxy methacrylate is preferably low from the viewpoint of workability, and the epoxy equivalent of the epoxy resin as a raw material is preferably 200 g / eq or less.

The component (A) is preferably a liquid rubber. The liquid rubber is a rubbery compound which is liquid at normal temperature, and examples thereof include polybutadiene and polyisoprene.
Further, the component (A) is preferably a polybutadiene or polyisoprene compound having an epoxy group in the molecule. This compound can realize low moisture permeability by the ring opening reaction of the epoxy group while having flexibility. Conventionally, polybutadiene and polyisoprene are mainly reacted by using a terminal double bond, but while the reactivity is fast in radical reaction, sufficient crosslinking can not be obtained, and it is thought that moisture permeability is deteriorated. .

The polybutadiene compound having an epoxy group is a compound in which an epoxy group is introduced in the molecule by epoxidizing at least a part of a carbon-carbon double bond contained in a butadiene skeleton. The epoxidized polybutadiene compound is not particularly limited, and examples thereof include those having a hydroxyalkyl group such as a hydrogen atom, a hydroxy group, a carboxy group, a cyano group or a hydroxyethyl group at both ends of the main chain.
Furthermore, as the component (A), a compound further having a reactive double bond in the molecule is preferable. The cured product properties are designed to be obtained by the ring opening reaction of epoxy groups while taking advantage of the rapid reactivity of the radical effect, which is more useful.

  As the epoxidized polybutadiene compound, a compound having a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2), or a repeating unit represented by the following formula (3) or the following formula (4) The compound which has a repeating unit shown by these is mentioned.

  As the epoxidized polybutadiene compound, a compound represented by the following formula (5) or a compound represented by the following formula (6) is preferable.

式中、ｍ及びｎは、それぞれ繰り返し単位数であって、１以上の整数である。

In the formula, m and n each represent the number of repeating units and are integers of 1 or more.

式中、ｏ，ｐ及びｑは、それぞれ繰り返し単位数であって、１以上の整数である。Ｒ_１は水素原子、ヒドロキシ基、カルボキシ基、シアノ基、ヒドロキシエチル基を表し、水素原子又はヒドロキシ基であることが好ましい。

In the formula, o, p and q each represent the number of repeating units and are integers of 1 or more. R ₁ represents a hydrogen atom, a hydroxy group, a carboxy group, a cyano group or a hydroxyethyl group, preferably a hydrogen atom or a hydroxy group.

  A polybutadiene compound having an epoxy group can be obtained by reacting a polybutadiene resin with an epoxidizing agent. In the polybutadiene resin which is the raw material, the steric structure of the double bond site may be any of cis-1,4 trans-1,4, trans-1,2, cis-1,2. Also, their ratio may be arbitrary. As the epoxidizing agent, organic peracids such as peracetic acid, formic acid, perbenzoic acid, trifluoroperacetic acid, perpropionic acid, etc., hydrogen peroxide, organic hydroperoxides such as t-butyl hydroperoxide, cumene hydroperoxide, etc. Oxides can be used. As the organic peracid, in order to increase the oxirane oxygen concentration of the target substance, one substantially free of water (for example, 0.8% by weight or less in water content) is preferable. Among the above-mentioned epoxidizing agents, peracetic acid is particularly preferable from the viewpoint of low cost industrial availability and high stability.

Further, the number-average molecular weight of the epoxidized polydiene resin is preferably 500 as the lower limit of the component from the viewpoint of gas emission from a sealing agent for display and liquid crystal peripheral material such as liquid crystal staining when used as a liquid crystal sealing agent More preferably, it is 750, and particularly preferably 1000.
The upper limit of the number average molecular weight of the component (A) is preferably 10,000, more preferably 8,000, and particularly preferably 6,000, from the viewpoint of handling.

  As component (A), for example, JP-100, JP-200, JP-400 (all are Nippon Soda Co., Ltd. (made)), Epolide PB3600, Epolide PB4700 (all are Daicel Co., Ltd.), BF-1000 They can be obtained from the market as (ADEKA (made)) and Ricon 657 (made by Clay Valley (made)).

[(B) curable compound]
The case where the sealing agent for displays of the present invention contains a component (B) curable compound (hereinafter, also simply referred to as "component (B)") is preferable.

[(B-1) (meth) acrylic compound]
The component (B) is not particularly limited as long as it is a compound which is cured by light, heat and the like, but it is the component (B-1) (meth) acrylic compound (hereinafter, also simply referred to as component (B-2)). The case is preferred. Here, "(meth) acrylic" means "acrylic" and / or "methacrylic". Examples of the component (B-1) include (meth) acrylic ester compounds and epoxy (meth) acrylate compounds. Among these, an epoxy (meth) acrylate compound is preferable.
Specific examples of (meth) acrylic ester compounds include N-acryloyloxyethyl hexahydrophthalimide, acryloyl morpholine, 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 Meta) acrylate, o-phenylphenol polyethoxy (meth) acrylate, p-cumyl phenoxyethyl (meth) acrylate, isobonyl (meth) acrylate, tribromophenyl Nyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyl oxyethyl (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6 -Hexanediol di (meth) acrylate, 1, 9 nonane diol di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, bisphenol A polyethoxy di (meth) acrylate, bisphenol A polypropoxy di (meth) acrylate, bisphenol F polyethoxy di (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, tris (acryloxyethyl) isocyanurate, pentaerys Tall tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate, trimethylolpropane tri (meth) Acrylate, trimethylolpropane polyethoxy tri (meth) acrylate, ditrimethylol propane tetra (meth) acrylate, ester diacrylate of neopentyl glycol and hydroxypivalic acid, and ε-caprolactone adduct of neopentyl glycol and ester of hydroxypivalic acid Monomers such as diacrylate can be mentioned. Preferably, N-acryloyloxyethyl hexahydrophthalimide, phenoxyethyl (meth) acrylate, and dicyclopentenyl oxyethyl (meth) acrylate can be mentioned.
The epoxy (meth) acrylate compound is obtained by the reaction of an epoxy compound and (meth) acrylic acid by a known method. The epoxy compound as the raw material is not particularly limited, but is preferably a difunctional or higher epoxy compound, for example, resorcinol diglycidyl ether, bisphenol A epoxy compound, bisphenol F epoxy compound, bisphenol S epoxy compound , Phenol novolac epoxy compound, cresol novolac epoxy compound, bisphenol A novolac epoxy compound, bisphenol F novolac epoxy compound, alicyclic epoxy compound, aliphatic chain epoxy compound, glycidyl ester epoxy compound, glycidyl amine epoxy Compound, hydantoin type epoxy compound, isocyanurate type epoxy compound, phenol novolac type epoxy compound having triphenolmethane skeleton, and the like Catechol, bifunctional phenols diglycidyl ethers of resorcinol and the like, bifunctional alcohols diglycidyl ethers of, and their halides, and the like hydrogenated product. Among them, bisphenol A epoxy compounds and resorcin diglycidyl ether are preferable from the viewpoint of liquid crystal contamination. Moreover, the ratio of an epoxy group and a (meth) acryloyl group is not limited, It selects suitably from a viewpoint of process compatibility.
Component (B) may be used alone or in combination of two or more. When the component (B) is used in the sealant for a display of the present invention, it is usually 10 to 80% by mass, preferably 20 to 70% by mass in the total amount of the sealant for a display.

[(B-2) epoxy compound]
In a preferred embodiment of the present invention, the component (B) further contains the component (B-2) epoxy compound (hereinafter, also simply referred to as the component (B-2)).
The epoxy compound is not particularly limited, but is preferably a difunctional or higher epoxy compound, for example, resorcinol diglycidyl ether, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, phenol novolac epoxy Epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, bisphenol F novolac type epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, hydantoin type Epoxy resin, isocyanurate type epoxy resin, phenol novolac type epoxy resin having triphenolmethane skeleton, other, bifunctional functional groups such as catechol and resorcinol Diglycidyl ethers of Nord acids, difunctional alcohols diglycidyl ethers of, and their halides, and the like hydrogenated product. Among them, bisphenol A epoxy resin and resorcin diglycidyl ether are preferable from the viewpoint of liquid crystal contamination.
The component (B-2) may be used alone or in combination of two or more. When the component (B-2) is used in the sealant for a display of the present invention, the total amount of the sealant for a display is usually 5 to 50% by mass, preferably 5 to 30% by mass.

[(C) thiol compound]
The sealant for a display of the present invention may contain component (C) a thiol compound (hereinafter, also simply referred to as component (C)). Component (C) reacts with both the epoxy group of component (A) and the reactive double bond, so it is very useful to add it.
The component (C) is not particularly limited as long as it is a compound having a thiol group in the molecule, but a thiol compound having a secondary thiol group is preferable from the viewpoint of storage stability and reactivity.
The number of thiol groups is preferably two or more in the molecule (polyfunctional thiol compound), and more preferably trifunctional or tetrafunctional.
When the sealing agent for a display of the present invention is used as a sealing agent for electronic components, the thiol equivalent of the thiol compound is preferably 80 or more, more preferably 100 or more, from the viewpoint of suppression of gas generation and the like. Further, the molecular weight is preferably 250 or more, more preferably 500 or more.
Component (C) may be used alone or in combination of two or more. When the component (C) is used in the sealant for a display of the present invention, it is usually 0.1 to 30% by mass, preferably 0.5 to 20% by mass, based on the total amount of the sealant for a display.

[(D) Organic filler]
The display sealing agent of the present invention may contain component (D) an organic filler (hereinafter, also simply referred to as component (D)). Examples of the organic filler include urethane particles, acryl particles, styrene particles, styrene olefin particles, and silicone particles. In addition, as silicone microparticles, KMP-594, KMP-597, KMP-598 (made by Shin-Etsu Chemical Co., Ltd.), Trefil ^RTM E-5500, 9701, EP-2001 (made by Toray Dow Corning) are preferable, and as urethane microparticles, JB- 800T, HB-800BK (Kegami Kogyo Co., Ltd.), preferred as styrene fine particles are Lavalon ^RTM T320C, T331C, SJ4400, SJ5400, SJ6400, SJ4300C, SJ5300C, SJ6300C (Mitsubishi Chemical), and as styrene olefin fine particles is Septon ^RTM SEPS 2004, SEPS 2063 is preferred.
These organic fillers may be used alone or in combination of two or more. Moreover, it is good also as core-shell structure using 2 or more types. Among these, acrylic fine particles and silicone fine particles are preferable.
When using the said acryl fine particle, the case where it is an acryl rubber of the core-shell structure which consists of 2 types of acryl rubber is preferable, Especially preferably, a thing whose core layer is n-butyl acrylate and whose shell layer is methyl methacrylate is preferable. This is marketed by Aika Industry Co., Ltd. as Zefiac ^RTM F-351.
Further, as the above-mentioned silicone fine particles, there can be mentioned organopolysiloxane crosslinked powder, linear dimethylpolysiloxane crosslinked powder and the like. Moreover, as composite silicone rubber, what coated silicone resin (for example, polyorgano silsesquioxane resin) on the surface of the said silicone rubber is mention | raise | lifted. Among these fine particles, particularly preferred are silicone rubber of linear dimethylpolysiloxane crosslinked powder or complex silicone rubber microparticles of silicone resin-coated linear dimethylpolysiloxane crosslinked powder. These may be used alone or in combination of two or more. Also, preferably, the shape of the rubber powder is spherical with less thickening of viscosity after addition. When the component (D) is used in the sealant for a display of the present invention, the total amount of the sealant for a display is usually 5 to 50% by mass, preferably 5 to 40% by mass.

[(E) Inorganic filler]
The sealant for a display of the present invention may contain component (E) an inorganic filler (hereinafter, also simply referred to as component (E)). As the inorganic filler contained in the present invention, 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, etc., preferably fused silica, crystalline silica, silicon nitride, nitrided Boron, calcium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, alumina, aluminum hydroxide, calcium silicate and aluminum silicate can be mentioned, with preference given to silica, alumina and talc. These inorganic fillers may be used as a mixture of two or more.
If the average particle diameter of the inorganic filler is too large, it may be a defect factor such that the gap formation at the time of bonding of the upper and lower glass substrates can not be performed well when producing a narrow gap liquid crystal cell. More preferably, it is 300 nm or less. The lower limit is preferably about 10 nm, and more preferably about 100 nm. The particle diameter can be measured by a laser diffraction / scattering type particle size distribution measuring device (dry type) (manufactured by Seishin Enterprise Co., Ltd .; LMS-30).
When an inorganic filler is used in the sealant for a display of the present invention, it is usually 5 to 50% by mass, preferably 5 to 40% by mass, in the total amount of the liquid crystal sealing agent.

[(F) Silane coupling agent]
Component (F) a silane coupling agent (hereinafter, also simply referred to as component (F)) can be added to the sealant for a display of the present invention to improve adhesion strength and moisture resistance.
As the component (F), 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl tritrile Methoxysilane, 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-chloropropyl Chill dimethoxysilane, 3-chloropropyl trimethoxy silane, and the like. Since these silane coupling agents are sold by Shin-Etsu Chemical Co., Ltd. as KBM series, KBE series etc., they are easily available from the market. When the component (F) is used in the sealant for a display of the present invention, 0.05 to 3% by mass of the total sealant for a display is preferable.

[(G) heat curing agent]
The display sealing agent of the present invention may contain component (G) a thermosetting agent (hereinafter, also simply referred to as component (G)). The component (G) is reacted nucleophilically by a noncovalent electron pair or an anion in the molecule, and examples thereof include polyhydric amines, polyhydric phenols, organic acid hydrazide compounds and the like. However, it is not limited to these. Among these, organic acid hydrazide compounds are particularly preferably used. For example, aromatic hydrazide terephthalic acid dihydrazide, isophthalic acid dihydrazide, 2,6-naphthoic acid dihydrazide, 2,6-pyridine dihydrazide, 1,2,4-benzenetrihydrazide, 1,4,5,8-naphthoic acid Tetrahydrazide, pyromellitic acid tetrahydrazide and the like can be mentioned. And aliphatic hydrazide compounds such as form hydrazide, acetohydrazide, propionic acid hydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric 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'-hexamethylene bissemicarbazide, citric acid trihydrazide, nitriloacetic acid trihydrazide, cyclohexane tricarboxylic acid trihydrazide, 1,3-bis ( Hydantoin skeletons such as hydrazino carbonoethyl) -5-isopropyl hydantoin, preferably valine hydantoin skeleton (where the carbon atom of the hydantoin ring is Dihydrazide compounds having a skeleton substituted with a propyl group, tris (1-hydrazinocarbonylmethyl) isocyanurate, tris (2-hydrazinocarbonylethyl) isocyanurate, tris (1-hydrazinocarbonylethyl) isocyanurate, tris Examples thereof include (3-hydrazinocarbonylpropyl) isocyanurate, bis (2-hydrazinocarbonylethyl) isocyanurate and the like. Preferably, from the balance of 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.
The component (G) may be used alone or in combination of two or more. When the component (G) is used in the sealant for a display of the present invention, the total amount of the sealant for a display is usually 0.1 to 10% by mass, preferably 1 to 5% by mass.

[(H) radical photopolymerization initiator]
The sealant for a display of the present invention may contain component (H) photoradical polymerization initiator (hereinafter, also simply referred to as component (H)). The photo radical polymerization initiator is not particularly limited as long as it is a compound which generates a radical or an acid upon irradiation with ultraviolet light or visible light to initiate a chain polymerization reaction. For example, benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone Diethylthioxanthone, benzophenone, 2-ethylanthraquinone, 2-hydroxy-2-methylpropiophenone, 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propane, 2,4,6- Trimethyl benzoyl diphenyl phosphine oxide, camphor quinone, 9-fluorenone, diphenyl dishydride etc. can be mentioned. Specifically, IRGACURE ^RTM 651, 184, 2959, 127, 907, 369, 379 EG, 819, 784, 754, 500, OXE01, OXE02, DAROCURE ^RTM 1173, LUCIRIN ^RTM TPO (all manufactured by BASF Corporation), Seikoll ^RTM Z, BZ, BEE, BIP, BBI (all manufactured by Seiko Instruments Inc.) and the like can be mentioned.
Further, from the viewpoint of liquid crystal staining, it is preferable to use one having a (meth) acryl group in the molecule, for example, 2-methacryloyloxyethyl isocyanate and 1- [4- (2-hydroxyethoxy) -phenyl]- The reaction product with 2-hydroxy-2 methyl-1-propan-1-one is preferably used. This compound can be obtained by preparation according to the method described in WO 2006/027982.
When the component (H) is used in the sealant for display of the present invention, it is usually 0.001 to 3% by mass, preferably 0.002 to 2% by mass in the total amount of the sealant for display.

[(I) thermal radical polymerization initiator]
The sealant for a display of the present invention can improve the curing speed and the curability by containing the component (I) thermal radical polymerization initiator (hereinafter, also simply referred to as "component (I)").
The thermal radical polymerization initiator is not particularly limited as long as it generates a radical by heating to initiate chain polymerization reaction, but organic peroxides, azo compounds, benzoin compounds, benzoin ether compounds, acetophenone compounds, benzopinacol, etc. Preferably, benzopinacol is used. For example, as organic peroxides, Kayamec ^RTM A, M, R, L, LH, SP-30C, Percadox CH-50L, BC-FF, Cadox B-40 ES, Percadox 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-50 E, AN, Kayabutyl ^RTM B, Perka Dox 16 Kayacaron ^RTM BIC-75, AIC-75 (manufactured by Kayaku Akzo Co., Ltd.), Permec ^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} , Percumyl ^RT H, D, PEROYL ^RTM IB, IPP, Perocta ^RTM ND (manufactured by NOF Corporation) and the like are commercially available.

  Moreover, as an azo compound, VA-044, 086, V-070, VPE-0201, VSP-1001 (made by Wako Pure Chemical Industries Ltd.) etc. are available as a commercial item.

  The content of the component (I) is preferably 0.0001 to 10% by mass, more preferably 0.0005 to 5% by mass, based on the total amount of the sealing agent for display, and 0.001 to 3%. % By weight is particularly preferred.

[Other ingredients]
The sealant for a display of the present invention may further be blended with additives such as a curing accelerator such as an organic acid and imidazole, a radical polymerization inhibitor, a pigment, a leveling agent, an antifoamer, and a solvent, as necessary. Can.

[Hardening accelerator]
Examples of the curing accelerator include organic acids and imidazoles.
As an organic acid, although an organic carboxylic acid, an organic phosphoric acid, etc. are mentioned, the case where it is an organic carboxylic acid is preferable. Specifically, aromatic carboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, benzophenone tetracarboxylic acid, furandicarboxylic acid, succinic acid, adipic acid, dodecanedioic acid, sebacic acid, thiodipropionic acid And cyclohexanedicarboxylic acid, tris (2-carboxymethyl) isocyanurate, tris (2-carboxyethyl) isocyanurate, tris (2-carboxypropyl) isocyanurate, bis (2-carboxyethyl) isocyanurate and the like. .
In addition, as an imidazole compound, 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-dihydroxymethyl Examples include imidazole, 2-phenyl-4-hydroxymethyl-5-methylimidazole, 1-cyanoethyl-2-phenyl-3,5-dicyanoethoxymethylimidazole and the like.
When a curing accelerator is used in the sealant for a display of the present invention, it is usually 0.1 to 10% by mass, preferably 1 to 5% by mass in the total amount of the sealant for a display.

[Radical polymerization inhibitor]
The radical polymerization inhibitor is not particularly limited as long as it is a compound which reacts with radicals generated from photo radical polymerization initiators, thermal radical polymerization initiators, etc. to prevent polymerization, and quinones, piperidines, Hindered phenol type, nitroso type etc. 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-methylphenyl) propionyloxy [ethyl], 2,4,8,10-tetraoxaspiro [5,5 5] Undecane, tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl propionate)] methane, 1,3,5-tris (3 ′, 5′-di) -T-Butyl-4'-hydroxybenzyl) -sec-triazine-2,4,6- (1H, 3H, 5H) trione, paramethoxyphenol, 4-methoxy-1-naphthol, thiodiphenylamine, N- Toro Seo aluminum salts of phenyl hydroxy amine, trade name ADK STAB LA-81, but such trade name ADK STAB LA-82 (manufactured by KK ADEKA) and the like, but is not limited thereto. Among them, naphthoquinone type, hydroquinone type and nitroso type piperazine type radical polymerization inhibitors are preferable, and naphthoquinone, 2-hydroxynaphthoquinone, hydroquinone, 2,6-di-t-butyl-P-cresol, polystop 7300P (Shinto stock More preferably manufactured by company, and most preferably Polystop 7300P (manufactured by Shoto Co.).
The content of the radical polymerization inhibitor is preferably 0.0001 to 1% by mass, more preferably 0.001 to 0.5% by mass, and still more preferably 0.01 to 0.2% of the total amount of the sealing agent for a display of the present invention. % By weight is particularly preferred.

  As an example of the method for obtaining the sealing agent for a display of the present invention, there are the following methods. First, the component (A) and, if necessary, the component (H) are heated and dissolved in the component (B) (when using the component (B-1) and the component (B-2), a mixture thereof). Then, after cooling to room temperature, component (C), component (D), component (E), component (F), component (G), component (I), an antifoaming agent, and a leveling agent, a solvent, if necessary The sealing agent for a display of the present invention can be produced by uniformly mixing with a known mixing device such as a 3-roll mill, a sand mill, a ball mill etc. and filtering through a metal mesh.

  In addition, the sealant for a display of the present invention is very useful as an adhesive for liquid crystal display cells and an adhesive for organic EL, particularly as a liquid crystal sealant. An example is shown below about a liquid crystal display cell at the time of using the sealing agent for displays of this invention as a liquid-crystal sealing agent.

In a liquid crystal display cell manufactured using the adhesive for liquid crystal display cell of the present invention, a pair of substrates having a predetermined electrode formed on the substrate is disposed opposite to each other at a predetermined distance, and the periphery is sealed with the liquid crystal sealant of the present invention The liquid crystal is sealed in the gap. The type of liquid crystal to be enclosed is not particularly limited. Here, the substrate is composed of a combination of light transmitting property to at least one of glass, quartz, plastic, silicon and the like. As the manufacturing method, after adding a spacer (space control material) such as glass fiber to the liquid crystal sealing agent of the present invention, the liquid crystal sealing agent is applied to one of the pair of substrates using a dispenser or a screen printing apparatus. After curing, temporary curing is performed at 80 to 120 ° C., if necessary. Thereafter, liquid crystal is dropped on the inner side of the ridge of the liquid crystal sealing agent, the other glass substrate is superposed in vacuum, and the gap is taken out. 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. In the case of using as a light and heat combination type, the liquid crystal sealing agent portion is irradiated with ultraviolet light by an ultraviolet light irradiator and light curing is performed. UV irradiation dose is preferably 500~6000mJ / cm ^2, more preferably 1000~4000mJ / cm ^2. Thereafter, 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 as required. The liquid crystal display cell of the present invention thus obtained is free from display defects due to liquid crystal contamination, and is excellent in adhesion and moisture resistance. As a spacer, glass fiber, a silica bead, a polymer bead etc. are mention | raise | lifted, for example. The diameter varies depending on the purpose, but is usually 2 to 8 μm, preferably 4 to 7 μm. The amount thereof used is usually about 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 with respect to 100 parts by mass of the liquid crystal sealing agent of the present invention is there.

  The sealant for a display of the present invention is compatible with flexibility and low moisture permeability, so that a flexible substrate or the like is used, and it is very suitable for use in an adhesive application in a field requiring moisture reliability and reliability. It is a thing. For example, a liquid crystal sealing agent, a sealant for an organic EL, and an adhesive for a touch panel.

  Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the examples. In the following description, "part" and "%" are based on mass unless otherwise specified.

[Examples 1 to 10, Comparative Examples 1 to 4]
The component (A) and the component (H) are heated at 90 ° C. to the component (B) (when using the component (B-1) and the component (B-2) in the ratio shown in Table 1 below, a mixture thereof) After dissolving, the mixture is cooled to room temperature, and component (C), component (D), component (E), component (F), component (G) and component (I) are added and stirred, and then three-roll mill The resultant mixture was dispersed at room temperature and filtered through a metal mesh (635 mesh) to prepare Liquid Crystal Sealant Examples 1 to 10. Further, Comparative Example 1 and 2 were prepared except for the component (A), and the comparative examples 3 and 4 were prepared using the component (A ′) while changing the component (A).

[Elasticity measurement]
The liquid crystal sealing agents manufactured in Examples and Comparative Examples were sandwiched between polyethylene terephthalate (PET) films and made into thin films with a thickness of 100 μm using a metal halide lamp (made by Ushio Electric Co., Ltd.) 3000 mJ / cm ² (100 mW / cm ⁽² ) for 30 seconds) and then cured by being placed in an oven at 120 ° C. for 40 minutes. Thereafter, the PET film was peeled off and the cured sealant film was cut into a dumbbell-shaped test piece (total length 75 mm, overall width 10 mm, narrow parallel portion length 50 mm, width 5 mm) to obtain a sample piece. The obtained test pieces were subjected to a tensile test at room temperature (22 ° C.) at a test speed of 5 mm / min using a TENSILON universal testing machine (RTG-1210, manufactured by A & D Co., Ltd.). The modulus of elasticity was calculated from the results of tensile stress and strain. The results are shown in Tables 1 and 2.

[Glass transition temperature (Tg)]
The liquid crystal sealing agents manufactured in Examples and Comparative Examples were sandwiched between polyethylene terephthalate (PET) films and made into thin films with a thickness of 100 μm using a metal halide lamp (made by Ushio Electric Co., Ltd.) 3000 mJ / cm ² (100 mW / cm ⁽² ) for 30 seconds) and then cured by being placed in an oven at 120 ° C. for 40 minutes. Thereafter, the PET film was peeled off and the cured sealing agent film was cut into strips of 50 mm × 5 mm to obtain sample pieces. The sample piece was measured under the conditions of a frequency 10 Hz and a temperature elevation temperature of 2 ° C./min in a tension mode of a dynamic viscoelasticity measuring apparatus (DMS-6100: manufactured by SII Nano Technology Inc.). The temperature at which the loss coefficient Tan δ is obtained from the ratio of the loss elastic modulus to the storage elastic modulus (JIS K 7244-1) and the obtained loss coefficient Tan δ is the maximum value is taken as the glass transition temperature (Tg). The results are shown in Tables 1 and 2.

Moisture Permeability
The liquid crystal sealing agents manufactured in Examples and Comparative Examples were sandwiched between polyethylene terephthalate (PET) films and made into thin films with a thickness of 100 μm using a metal halide lamp (made by Ushio Electric Co., Ltd.) 3000 mJ / cm ² (100 mW / cm ⁽² ) for 30 seconds) and then cured by being placed in an oven at 120 ° C. for 40 minutes. Thereafter, the PET film was peeled off and used as a sample. The moisture permeability at 60 ° C. and 90% of the sample was measured with a moisture permeability measuring device (Lessy: L80-5000). The results are shown in Tables 1 and 2.

[Flexibility]
The liquid crystal sealing agents manufactured in Examples and Comparative Examples were sandwiched between polyethylene terephthalate (PET) films and made into thin films with a thickness of 100 μm using a metal halide lamp (made by Ushio Electric Co., Ltd.) 3000 mJ / cm ² (100 mW / cm ⁽² ) for 30 seconds) and then cured by being placed in an oven at 120 ° C. for 40 minutes. Thereafter, the PET film was peeled off and the cured sealing agent film was cut into strips of 50 mm × 5 mm to obtain sample pieces. The obtained sample was wound around a 2 mm 棒 rod and fixed for 10 seconds. The sample in which the test pieces were not broken was evaluated as ○, and the one in which the test pieces were cracked was evaluated as x. The results are shown in Tables 1 and 2.

[Drawability]
1 g of glass fiber with a diameter of 5 μm (PF-50S; made by Nippon Electric Glass Co., Ltd.) was added as a spacer to 100 g of each of the liquid crystal sealing agents manufactured in Examples and Comparative Examples to carry out mixing, stirring and degassing, and filled in a syringe . A seal pattern and a dummy seal pattern are applied using a dispenser (SHOTMASTER 300: manufactured by Musashi Engineering Co., Ltd.) with a liquid crystal sealing agent previously filled in a syringe on a glass substrate with an ITO transparent electrode, and drawing is possible. A clean one was evaluated as ○, a drawable but dirty linear shape of the seal was evaluated as Δ, and a non-drawable one as x. The results are shown in Tables 1 and 2.

[Compatibility evaluation]
Component (A) was mixed with the same mass of bisphenol A epoxy methacrylate at 90 ° C. for 1 hour, and allowed to stand at 22 ° C. for 1 hour. The state after the mixture was allowed to stand was evaluated as ○ is compatible, Δ is slightly turbid, x is turbid or segregated. The incompatible components are shown in Table 1 and Table 2 as Component (A '). The results of the compatibility evaluation are shown in Table 3.

  As shown in Table 1, the sealing agent for displays of Examples 1 to 10 is excellent in the drawing property and high in flexibility, and yet the moisture permeability is also low. Therefore, it was confirmed that the sealing agent for a display of the present invention has excellent properties as an adhesive used for a flexible substrate or the like.

  The sealing agent for a display of the present invention is excellent in drawing property and compatible with flexibility and low moisture permeability, and thus is useful as an adhesive for electronic parts, particularly as a sealing agent for a display.

Claims (21)

  The sealing agent for displays whose glass transition temperature of hardened | cured material measured by a dynamic-viscoelasticity measurement method is 90 degreeC or more, and the elasticity modulus in 22 degreeC measured with a Tentilon universal tester is 2000 Mpa or less.   Component (A): A compound which is mixed with the same mass of bisphenol A-type epoxy methacrylate by heating at 90 ° C. and does not cause white turbidity or causes separation of components even if left at 22 ° C. for 1 hour. Sealant for displays.   The sealant for a display according to claim 2, wherein the component (A) is a liquid rubber.   The sealing agent for a display according to claim 2 or 3, wherein the component (A) is a polybutadiene compound having an epoxy group in the molecule.   The sealing agent for displays according to any one of claims 2 to 4, wherein the component (A) is a compound having a reactive double bond in a molecule.   The sealant for a display according to any one of claims 2 to 5, wherein a number average molecular weight of the component (A) is 500 or more and 10000 or less.   Furthermore, the sealing agent for displays as described in any one of the Claims 1 thru | or 6 containing a component (B) curable compound.   The sealant for a display according to claim 7, wherein the component (B) is a component (B-1) (meth) acrylic compound.   The sealant for display according to claim 7, wherein the component (B) is a mixture of the component (B-1) (meth) acrylic compound and the component (B-2) epoxy compound.   The sealant for display according to claim 8 or 9, wherein the component (B-1) is an epoxy (meth) acrylate.   Furthermore, the sealing agent for displays as described in any one of the Claims 1 thru | or 10 containing a component (C) thiol compound.   Furthermore, the sealing agent for displays as described in any one of the Claims 1-11 containing the component (D) organic filler.   The sealing agent for a display according to claim 12, wherein the component (D) is one or more organic fillers selected from the group consisting of urethane particles, acryl particles, styrene particles, styrene olefin particles, and silicone particles. .   Furthermore, the sealing agent for displays as described in any one of the Claims 1-13 containing the component (E) inorganic filler.   Furthermore, the sealing agent for displays as described in any one of the Claims 1-14 containing the component (F) silane coupling agent.   Furthermore, the sealing agent for displays as described in any one of the Claims 1-15 containing the component (G) thermosetting agent.   The sealant for a display according to claim 16, wherein the component (G) is an organic acid hydrazide compound.   Furthermore, the sealing agent for displays as described in any one of the Claims 1-17 containing component (H) radical photopolymerization initiator.   The sealant for display according to any one of claims 1 to 18, further comprising component (I) a thermal radical polymerization initiator.   The liquid-crystal sealing compound using the sealing compound for displays as described in any one of Claims 1-19.   A liquid crystal display cell bonded using the liquid crystal sealant according to claim 20.