WO2019065455A1 - Image display device sealing material and image display device sealing sheet - Google Patents

Abstract

The image display device sealing material according to the present invention contains a resin component and a curing agent. The resin component contains a bisphenol-skeleton-containing phenoxy resin having a weight-average molecular weight of 10,000 to 100,000, an alicyclic-skeleton-containing epoxy resin having a weight-average molecular weight of 180 to 790, a styrene-based oligomer having a weight-average molecular weight of 750 to 4000, and a non-styrene-based oligomer having a weight-average molecular weight of 500 to less than 10,000 and a solubility parameter of 8.9 (cal/cm3)1/2 or greater.

Description

Image display device sealing material and image display device sealing sheet

The present invention relates to an image display device sealing material and an image display device sealing sheet.

As an image display apparatus provided with an optical element, a liquid crystal display, an organic electroluminescent display, etc. are known, for example. In such an image display device, the optical element is sealed by a seal member in order to suppress the deterioration of the optical element due to moisture and the like in the air.

The sealing member is formed, for example, by embedding the optical element in the sealing composition and then curing the sealing composition. Therefore, in order to provide the sealing member with required performance according to various applications, various studies have been made on the composition of the sealing composition.

For example, it contains a bisphenol epoxy resin having a weight average molecular weight of 3 × 10 ³ to 1 × 10 ⁴ , a phenol epoxy resin having a weight average molecular weight of 200 to 800, a curing accelerator, and a silane coupling agent. A sealing composition is proposed (see, for example, Patent Document 1).

WO 2010/119706

However, when the sealing member formed from the composition for sealing of patent document 1 is used for the touch panel etc. of an organic EL display, for example, since the dielectric constant is high, the noise caused by the sealing member causes the touch panel May cause malfunction. Also, in such applications, the seal member needs to be transparent.

The present invention provides an image display device sealing material and an image display device sealing sheet capable of forming a sealing member having a relatively low dielectric constant and securing transparency.

The present invention [1] contains a resin component and a curing agent, and the resin component has a bisphenol skeleton-containing phenoxy resin having a weight average molecular weight of 10,000 to 100,000, and a weight average molecular weight of 180. Alicyclic skeleton-containing epoxy resin having a weight average molecular weight of 790 or less, styrene-based oligomer having a weight average molecular weight of 750 to 4,000, and a weight average molecular weight of 500 to 10,000, and a solubility parameter of 8.9 (cal / and an image display device sealing material containing a non-styrenic oligomer having a cm ^{3 of 1/2} or more.

In the present invention [2], the non-styrenic oligomer is an aliphatic hydrocarbon resin and / or a terpene phenol resin having a solubility parameter of 8.9 (cal / cm ³ ) ^1/2 or more. And the image display device sealing material described in 1.

The present invention [3] includes the image display device sealing material according to the above [1] or [2], wherein the content ratio of the non-styrenic oligomer in the resin component is 10% by mass or more. .

In the image display device according to any one of the above [1] to [3], the content ratio of the non-styrene-based oligomer to the styrene-based oligomer is 0.60 or more. Contains fixing material.

The present invention [5] includes the image display device sealing material according to the above [1] to [4], wherein the content ratio of the styrene-based oligomer in the resin component is more than 10% by mass.

The image display device according to any one of the above [1] to [5], wherein the content ratio of the alicyclic skeleton-containing epoxy resin in the resin component in the present invention [6] is less than 40% by mass. Contains encapsulant.

The present invention [7] includes an image display device sealing sheet having a sealing layer formed of the image display device sealing material according to any one of the above [1] to [6].

According to the image display device sealing material and the image display device sealing sheet of the present invention, since the solubility parameter of the non-styrene oligomer is equal to or more than the above lower limit, bisphenol skeleton-containing phenoxy resin, alicyclic skeleton-containing epoxy resin, Styrenic oligomers and non-styrenic oligomers can be compatible. Therefore, a styrene-based oligomer and a non-styrene-based oligomer can be contained in the resin component, and a sealing member having a relatively low dielectric constant and capable of securing transparency can be formed.

FIG. 1 is a side sectional view of a sealing sheet as an embodiment of the image display device sealing sheet of the present invention. FIG. 2 is a side sectional view of an organic EL display with a touch sensor as an embodiment (a mode having an in-cell structure or an on-cell structure) of an image display device including a seal member formed from the sealing layer shown in FIG. . FIG. 3A is an explanatory view for explaining an embodiment (a mode in which the sealing layer on the base film is attached to the substrate) of the method for manufacturing the organic EL display with a touch sensor shown in FIG. Shows the process of preparing FIG. 3B shows the process of affixing a sealing layer to a board | substrate so that an organic EL element may be embedded to a sealing layer following FIG. 3A. FIG. 3C shows the process of peeling a release film from a sealing layer and sticking a cover glass to a sealing layer following FIG. 3B. FIG. 4 is an explanatory view for explaining another embodiment (a mode in which a sealing layer on a cover glass or a barrier film is attached to a substrate) of a method for producing an organic EL display with a touch sensor. FIG. 5 is a side sectional view of an organic EL display with a touch sensor as another embodiment of the image display device (aspect having an outcell structure).

<Image Display Device Sealant>
The image display device sealing material (hereinafter referred to as a sealing material) of the present invention is a sealing resin composition (sealing resin composition for an image display device) for sealing an optical element provided in the image display device described later. It is a curable resin composition which forms a seal member described later by curing. The sealing material contains a resin component and a curing agent.

(1) Resin component The resin component is, as an essential component, a bisphenol skeleton-containing phenoxy resin having a weight average molecular weight (M _w ) of 10,000 to 100,000, and a weight average molecular weight (M _w ) of 180 to 790. And a styrenic oligomer having a weight average molecular weight (M _w ) of 750 to 4,000, and a weight average molecular weight (M _w ) of 500 to less than 10,000, and the solubility parameter is 8 And a non-styrenic oligomer which is not less than 9 (cal / cm ³ ) ^1/2 .

(1-1) Bisphenol Skeleton-Containing Phenoxy Resin The bisphenol skeleton-containing phenoxy resin is an epoxy resin having a bisphenol skeleton and an epoxy group and having a high molecular weight (M _w : 10,000 or more and 100,000 or less). The bisphenol skeleton-containing phenoxy resin is solid at normal temperature. In addition, "normal temperature solid" shows that it is a solid state which does not have fluidity at normal temperature (23 ° C), and "normal temperature liquid" means a liquid state having fluidity at normal temperature (23 ° C) To indicate that the same applies to the following.

Since the resin component contains a bisphenol skeleton-containing phenoxy resin, the sheet formability of the sealing material can be improved, and the moisture permeability of the sealing member (described later) can be reduced.

The weight average molecular weight (M _w ) of the bisphenol skeleton-containing phenoxy resin is 10,000 or more, preferably 20,000 or more, 30,000 or more, 100,000 or less, preferably 90,000 or less. The weight average molecular weight (M _w ) can be determined by gel permeation chromatography (GPC) using polystyrene as a standard substance (the same applies hereinafter).

The epoxy equivalent of the bisphenol skeleton-containing phenoxy resin is, for example, 2,000 g / eq. Or more, preferably 4,000 g / eq. Or more, more preferably 7,000 g / eq. For example, 20,000 g / eq. Or less, preferably, 16,000 g / eq. It is below. The epoxy equivalent can be measured in accordance with JIS K 7236: 2001 (the same applies hereinafter).

The bisphenol skeleton-containing phenoxy resin is compatible with the non-styrenic oligomer. The solubility parameter (hereinafter referred to as “SP value”) of the bisphenol skeleton-containing phenoxy resin is, for example, 11.5 (cal / cm ³ ) ^1/2 or more and 13.0 (cal / cm ³ ) ^1/2 or less. The SP value can be calculated by the calculation software CHEOPS (version 4.0) of Million Zillion Software (the same applies hereinafter). The calculation method used in the calculation software is described in Computational Materials Science of Polymers (AA. Askadskii, Cambridge Intl Science Pub (2005/12/30)) Chapter XII.

Such a bisphenol skeleton-containing phenoxy resin has, for example, a plurality of bisphenol skeletons and a plurality of epoxy groups (a multifunctional (difunctional containing) epoxy resin), preferably, a molecular chain containing a plurality of bisphenol skeletons And epoxy groups bonded to both ends of the molecular chain (bifunctional epoxy resin). The bisphenol skeleton-containing phenoxy resin does not contain a biphenyl skeleton.

As the bisphenol skeleton-containing phenoxy resin, for example, a bisphenol skeleton-containing phenoxy resin containing structural units I to III represented by the following formula (1) can be mentioned. The bisphenol skeleton-containing phenoxy resin containing the constitutional units I to III has a molecular chain containing a plurality of bisphenol skeletons and glycidyl ether units bonded to both ends of the molecular chain.
Formula (1)

[In Formula (1), I, II and III are structural units, and each of I and III is a terminal unit, II shows a repeating unit. R ¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. R ² represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms. ]
The bisphenol skeleton-containing phenoxy resin containing the constitutional units I to III shown in the above formula (1) is preferably used alone.

As an alkyl group shown as R ^{1 in the} above formula (1), for example, a linear alkyl group having 1 to 6 carbon atoms (eg, methyl, ethyl, propyl, butyl, pentyl, hexyl), a branch having 3 to 6 carbon atoms And alkyl groups (eg, isopropyl, isobutyl, tert-butyl and the like) and the like. Among R ^{1 in} the above formula (1), a hydrogen atom is preferably mentioned. The plurality of R ^{1 in} the above formula (1) may be identical to each other or different from each other, but preferably are identical.

Examples of the hydrocarbon group represented as R ^{2 in the} above formula (1) include the same alkyl group having 1 to 6 carbon atoms as the above R ¹ and an aryl group having 6 to 12 carbon atoms (eg, phenyl, tolyl, xylyl and the like) And the like. Among R ^{2 in} the above formula (1), preferred are a hydrogen atom and a methyl group. The plurality of R ^{2 in} the above formula (1) may be identical to one another or may be different from one another.

Further, the bisphenol skeleton-containing phenoxy resin containing the constituent units I to III shown in the above formula (1) contains a plurality of constituent units II. The combination of two R ² of the constituent unit II shown in the above-mentioned formula (1) may be identical in all the constituent units II, and a plurality of constituent units II are different in combination of two R ² from each other It may contain the unit II. The bisphenol skeleton-containing phenoxy resin represented by the above formula (1) is preferably a constituent unit II (bisphenol A skeleton) in which two R ^{2 s} are methyl groups, and a constituent unit II (wherein two R ^{2 s} are hydrogen atoms) And a bisphenol F skeleton).

The bisphenol skeleton phenoxy resin containing the constituent units I to III represented by the above formula (1) is, for example, a bisphenol compound (eg, bisphenol A, bisphenol F, 4,4 ′-(1-phenylethylidene) bisphenol, 4,4 It is a copolymer (reactant) of epichlorohydrin with '-(1-phenylpropylidene) bisphenol and the like.
The bisphenol compounds can be used alone or in combination of two or more. Among bisphenol compounds, preferably, bisphenol A and bisphenol F are mentioned, and more preferably, a combination of bisphenol A and bisphenol F is mentioned.

In addition to the constituent units I to III, the bisphenol skeleton phenoxy resin containing the constituent units I to III represented by the above formula (1) can also contain other constituent units. As another structural unit, the polyol unit etc. which originate in the polyol (for example, glycol, benzenediol etc., etc.) more than bivalence etc. are mentioned, for example.

A commercially available product can also be used as the bisphenol skeleton phenoxy resin containing the constituent units I to III shown in the above formula (1). As a commercial item of bisphenol skeleton phenoxy resin containing structural units I to III represented by the above formula (1), for example, JER-4275 (manufactured by Mitsubishi Chemical Corporation, weight average molecular weight: about 60,000, epoxy equivalent weight: 8,400) And JER-1256 (manufactured by Mitsubishi Chemical Corporation, weight average molecular weight: about 90,000, epoxy equivalent weight: 7,500 to 8,500 g / eq.), And the like.

In the resin component, the content ratio of the bisphenol skeleton-containing phenoxy resin is, for example, 5% by mass or more, preferably 10% by mass or more, for example, 50% by mass or less, preferably 40% by mass or less.

If the content ratio of the bisphenol skeleton-containing phenoxy resin is within the above range, the content ratio of the other resin component can be secured, and various properties required of the sealing material can be secured in a well-balanced manner.

(1-2) Alicyclic skeleton-containing epoxy resin The alicyclic skeleton-containing epoxy resin is an epoxy resin of low molecular weight (M _w : 180 or more and 790 or less) having at least an epoxy group and an aliphatic ring (alicyclic skeleton). is there. The alicyclic skeleton-containing epoxy resin is a normal temperature liquid. The alicyclic skeleton-containing epoxy resin does not have a bisphenol skeleton and a biphenyl skeleton.

Since the resin component contains an alicyclic skeleton-containing epoxy resin, the haze value of the seal member (described later) can be reduced as compared to the case where the resin component contains an aromatic ring skeleton-containing epoxy resin, and the transparency of the seal member (described later) As a result, the moisture permeability of the seal member (described later) can be reduced.

The weight average molecular weight of the alicyclic skeleton-containing epoxy resin is 180 or more and 790 or less, preferably 500 or less. The epoxy equivalent of the alicyclic skeleton-containing epoxy resin is, for example, 90 g / eq. Or more, preferably 100 g / eq. For example, 190 g / eq. Or less, preferably 200 g / eq. It is below.

The alicyclic skeleton-containing epoxy resin is compatible with non-styrenic oligomers, and has an SP value (for example, 9.0 (cal / cm ³ ) ^1/2 or more and 11.5 (cal) equivalent to that of non-styrenic oligomers. / Cm ³ ) ^1/2 or less).

The alicyclic skeleton-containing epoxy resin has, for example, a plurality of aliphatic rings and a plurality of epoxy groups (polyfunctional (including bifunctional) epoxy resin).

As an alicyclic skeleton-containing epoxy resin, for example, an epoxy group-containing epoxy group having an epoxy group composed of two adjacent carbon atoms forming an aliphatic ring and one oxygen atom bonded to the two carbon atoms Alicyclic skeleton epoxy resin (bifunctional epoxy resin), glycidyl ether containing alicyclic skeleton epoxy resin (polyfunctional epoxy resin) having a plurality of glycidyl ether units bonded to an aliphatic ring, and the like can be mentioned. The alicyclic skeleton-containing epoxy resin can be used alone or in combination of two or more.

Examples of the epoxy group-containing alicyclic epoxy resin include alicyclic epoxy compounds having a cycloalkene oxide structure.

As an alicyclic epoxy compound which has a cycloalkene oxide structure, the epoxy compound (It is set as the ECH structure containing epoxy compound hereafter) which has an epoxy cyclohexane structure shown by following formula (2), the modified material etc. are mentioned, for example Be
Formula (2)

[In Formula (2), X shows a single bond or a coupling group (bivalent group which has one or more atoms). A substituent such as an alkyl group may be bonded to a carbon atom constituting a cyclohexane ring. ]
The ECH structure-containing epoxy compound represented by the above formula (2) has an epoxycyclohexane structure (epoxycyclohexyl group) at both ends of the molecule, and two epoxycyclohexyl groups are directly bonded by a single bond or a linking group is Join through. The epoxycyclohexyl group is a functional group containing a cyclohexane ring, an epoxy group composed of two adjacent carbon atoms forming a cyclohexane ring, and one oxygen atom bonded to the two carbon atoms. It is.

When X is a single bond in the above formula (2), a carbon atom forming a cyclohexane ring of an epoxycyclohexyl group located at one end and a carbon atom forming a cyclohexane ring of an epoxycyclohexyl group located at the other end And are directly connected.

Examples of the linking group represented by X in the above formula (2) include a divalent hydrocarbon group, a carbonyl group, an ether group, a thioether group, an ester group, a carbonate group, an amide group, and a group in which these are linked. Be

As a divalent hydrocarbon group, for example, a linear or branched alkylene group having 1 to 18 carbon atoms (eg, methylene, methylmethylene, dimethylmethylene, ethylene, propylene, trimethylene, etc.), A cycloalkylene group (eg, 1,2-cyclopentylene group, 1,3-cyclopentylene group, 1,2-cyclohexylene group, 1,3-cyclohexylene group, 1,4-cyclohexylene group, etc.), And cycloalkylidene groups (eg, cyclopentylidene group, cyclohexylidene group, etc.) and the like.

Among the linking groups represented by X in the above formula (2), a linking group containing an oxygen atom is preferably mentioned from the viewpoint of adhesion of the seal member (described later), more preferably a carbonyl group, an ether group, An ester group and a carbonate group are mentioned, Especially preferably, an ester group is mentioned.

As an alkyl group which can be bonded to a carbon atom which constitutes a cyclohexane ring, for example, the same alkyl group as R ^{1 of the} above-mentioned formula (1) can be mentioned. In addition, preferably, no substituent is attached to the carbon atom constituting the cyclohexane ring (unsubstituted), and a hydrogen atom is attached.

As the ECH structure-containing epoxy compound represented by the above formula (2), for example, (3,3 ′, 4,4′-diepoxy) bicyclohexyl, bis (3,4-epoxycyclohexylmethyl) ether, 1,2-bis (3,4-epoxycyclohexan-1-yl) ethane, 1,2-epoxy-1,2-bis (3,4-epoxycyclohexan-1-yl) ethane, 2,2-bis (3,4-epoxy) Cyclohexane-1-yl) propane, 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate, ε-caprolactone modified 3 ', 4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboarylate, etc. It can be mentioned.

A commercial item can also be used for the ECH structure containing epoxy compound shown by the said Formula (2). Examples of commercially available products of the ECH structure-containing epoxy compound represented by the above formula (2) include Celoxide 8000, Celoxide 2021 P (epoxy equivalent weight 128 to 145 g / eq.), And Celoxide 2081 (all manufactured by Daicel).

As a glycidyl ether containing alicyclic frame epoxy resin, the dicyclopentadiene type epoxy resin (Hereafter, it is set as DCPD type epoxy resin.) Shown by following formula (3) is mentioned.
Formula (3)

[In Formula (3), a substituent such as an alkyl group may be bonded to a carbon atom constituting an aliphatic ring derived from dicyclopentadiene. ]
The DCPD epoxy resin represented by the above formula (3) has an aliphatic ring derived from dicyclopentadiene and two glycidyl ether units bonded to the aliphatic ring.

As an alkyl group which can be bonded to a carbon atom constituting an aliphatic ring derived from dicyclopentadiene, for example, the same alkyl group as R ^{1 in the} above formula (1) can be mentioned. Further, preferably, no substituent is bonded (unsubstituted) and a hydrogen atom is bonded to a carbon atom constituting an aliphatic ring derived from dicyclopentadiene.

A commercial item can also be used for DCPD type epoxy resin shown by said Formula (3). As a commercial product of the DCPD-type epoxy resin represented by the above formula (3), for example, EP-4088S (manufactured by ADEKA, epoxy equivalent 170 g / eq.) And the like can be mentioned.

Such an alicyclic skeleton-containing epoxy resin can be used alone or in combination of two or more, but is preferably used alone. That is, as the alicyclic skeleton-containing epoxy resin, preferably, either one of the ECH structure-containing epoxy compound represented by the above formula (2) and the DCPD epoxy resin represented by the above formula (3) is used alone.

When the alicyclic skeleton-containing epoxy resin is the sole use of the ECH structure-containing epoxy compound represented by the above formula (2), the alicyclic skeleton-containing epoxy resin is the single use of the DCPD epoxy resin represented by the above formula (3) The curing speed of the sealing material can be improved as compared to the case where it is present.

In the resin component, the content ratio of the alicyclic skeleton-containing epoxy resin is, for example, 10% by mass or more, preferably 20% by mass or more, for example, 50% by mass or less, preferably less than 40% by mass, more preferably 35 It is less than mass%.

When the content ratio of the alicyclic skeleton-containing epoxy resin is within the above range, the reduction of the haze value of the sealing member (described later) can be reliably achieved. If the content ratio of the alicyclic skeleton-containing epoxy resin is equal to or less than the above upper limit, the content ratio of the other resin component can be secured, and various properties required of the sealing material can be secured in a more balanced manner.

(1-3) Styrenic Oligomer The styrenic oligomer is a polymer in which vinyl groups of a plurality of styrene skeletons are bonded to each other, and has a plurality of styrene units derived from a plurality of styrene skeletons. The styrenic oligomer is a solid at normal temperature. The styrenic oligomer does not include high molecular weight styrene-butadiene-styrene block copolymer (SBS rubber) having a weight average molecular weight (M _w ) of more than 10,000.

The weight average molecular weight (M _w ) of the styrene-based oligomer is 750 or more, preferably 900 or more and 4000 or less, preferably 3800 or less. The number average molecular weight ( _Mn ) of the styrene-based oligomer is, for example, 500 or more, preferably 600 or more, more preferably 700 or more, for example, 2500 or less, preferably 2000 or less, more preferably 1500 or less .

Also, the weight average molecular weight / number average molecular weight (M _w / M _n ) is, for example, 1.1 or more, preferably 1.2 or more, more preferably 1.3 or more, for example, 2.5 or less, preferably Is 2.0 or less, more preferably 1.9 or less.

The styrenic oligomer is compatible with the non-styrenic oligomer, and has an SP value (for example, 8.5 (cal / cm ³ ) ^1/2 or more and 9.1 (cal / cm ³ ) similar to that of the non-styrenic oligomer. ) ^Or less)).

As a styrene-type oligomer, the homopolymer of a styrene frame | skeleton containing monomer, the copolymer of a styrene frame | skeleton containing monomer, and another polymeric monomer etc. are mentioned, for example. The styrenic oligomers can be used alone or in combination of two or more.

Examples of the styrene skeleton-containing monomer include styrene, α-methylstyrene, vinyl toluene, isopropenyl toluene and the like, preferably isopropenyl toluene. The styrene skeleton-containing monomers can be used alone or in combination of two or more.

Another polymerizable monomer is a monomer copolymerizable with the styrene skeleton-containing monomer, and has, for example, an ethylenically unsaturated double bond. As other polymerizable monomers, for example, unsaturated aliphatic monomers having 2 to 10 carbon atoms (for example, ethylene, propylene, butene, isobutene, butadiene, pentene, pentadiene, isoprene, hexadiene, methyl butene, etc.), 5 to carbon atoms Purification and decomposition of 20 unsaturated alicyclic monomers (eg, cyclopentadiene, dicyclopentadiene etc.), α, β-unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid etc.), (meth) acrylates, petroleum like C ₅ fraction obtained by such. The C5 fraction is a fraction having a boiling point range of -15 ° C to + 45 ° C under normal pressure and is 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 2-pentene, isoprene , 1,3-pentadiene, cyclopentadiene and the like. Other polymerizable monomers can be used alone or in combination of two or more.

In the copolymer of a styrene skeleton-containing monomer and another polymerizable monomer, the content ratio of the structural unit derived from the styrene skeleton-containing monomer is, for example, 50% by mass or more, preferably 80% by mass or more, for example, 99% % Or less, preferably 95% by mass or less.

Further, among styrenic oligomers, preferred are homopolymers of styrene skeleton-containing monomers. That is, the styrene-based oligomer preferably includes a homopolymer of a styrene skeleton-containing monomer, and more preferably, a homopolymer of a styrene skeleton-containing monomer is used alone.

When the styrene-based oligomer contains a homopolymer of a styrene skeleton-containing monomer (in particular, when a homopolymer of a styrene skeleton-containing monomer is used alone), the moisture permeability of the seal member (described later) can be reliably reduced. Can.

In the resin component, the content ratio of the styrenic oligomer is, for example, 1% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 10% by mass, particularly preferably 15 mass% or more, for example, 40 mass% or less, preferably 25 mass% or less.

The reduction of the haze value of a seal member (after-mentioned) can be certainly aimed at as the content rate of a styrene system oligomer is more than the above-mentioned minimum. The content ratio of the other resin component can be ensured as the content ratio of a styrene-type oligomer is below the said upper limit, and the various characteristics requested | required of a sealing material can be ensured more balancedly.

(1-4) Non-Styrene-Based Oligomer The non-styrene-based oligomer has a weight average molecular weight of 500 or more and less than 10,000, and an SP value of 8.9 (cal / cm ³ ) ^1/2 or more. Non-styrenic oligomers do not have a styrene backbone. The non-styrenic oligomer contains a ring skeleton (aliphatic ring and / or aromatic ring) and does not contain an epoxy group. Non-styrene oligomers are solid at normal temperature.

Since the resin component contains a styrene-based oligomer and a non-styrene-based oligomer, the haze value of the seal member (described later) can be reduced while the dielectric constant of the seal member (described later) can be reduced.

The SP value of the non-styrene oligomer is 8.9 (cal / cm ³ ) ^1/2 or more, for example, 11.5 (cal / cm ³ ) ^1/2 or less, preferably 11.5 (cal / cm ³⁾ It is less than ^1/2 , more preferably 10.0 (cal / cm ³ ) ^1/2 or less.

If the SP value of the non-styrene oligomer is equal to or more than the above lower limit, the compatibility with other resin components can be improved, and the sheet formability of the sealing material can be improved.

The weight average molecular weight (M _w ) of the non-styrenic oligomer is 500 or more and less than 10,000, preferably 4,000 or less.

If the weight average molecular weight of the non-styrene oligomer is within the above range, the compatibility with other resin components can be improved.

In addition, the softening point of the non-styrene-based oligomer is, for example, 80 ° C. or more, preferably 100 ° C. or more, more preferably 120 ° C. or more, for example, 150 ° C. or less. The softening point can be measured according to the method described in JIS K2207 (the same applies hereinafter).

If the softening point of the non-styrene-based oligomer is not less than the above lower limit, the moisture permeability of the sealing member (described later) can be reliably reduced.

As a non-styrene-based oligomer, for example, an aliphatic hydrocarbon resin having an SP value of 8.9 (cal / cm ³ ) ^1/2 or more (hereinafter, referred to as aliphatic hydrocarbon resin (A)), an SP value of Terpene phenol resin (it is hereafter set as terpene phenol resin (B)) which is 8.9 (cal / cm ³ ) ^1/2 or more etc. are mentioned. The non-styrene oligomers can be used alone or in combination of two or more.

The aliphatic hydrocarbon resin (A) is an aliphatic hydrocarbon resin having an SP value within the range of the SP value of the above non-styrenic oligomer, and preferably has an SP value of 9.0 (cal / cm ³ It is aliphatic hydrocarbon resin which is ^1/2 or more. The aliphatic hydrocarbon resin (A) is a flake-like solid at normal temperature.

For example, a petroleum hydrocarbon resin (preferably, a homopolymer of dicyclopentadiene) mainly composed of dicyclopentadiene extracted from a C5 fraction obtained by naphtha decomposition as an aliphatic hydrocarbon resin (A); The ester modified hydrocarbon resin etc. which ester group was introduce | transduced are mentioned. The ester-modified hydrocarbon resin is preferably used alone. The ester-modified hydrocarbon resin has an aliphatic ring derived from dicyclopentadiene and an atomic group containing an ester group. Examples of the atomic group containing an ester group include vinyl acetate units derived from vinyl acetate.

The range of the weight average molecular weight (Mw) of the ester-modified hydrocarbon resin is the same as the range of the weight average molecular weight (Mw) of the non-styrenic oligomer described above, and preferably 500 or more and 4,000 or less. The range of the softening point of the ester-modified hydrocarbon resin is, for example, the same as the range of the softening point of the above non-styrenic oligomer, and preferably 80 ° C. or more and less than 120 ° C.

The Ken number of the ester-modified hydrocarbon resin is, for example, 100 mg KOH / g or more and 200 mg KOH / g. The Ken number can be measured in accordance with the method described in JIS K 0070.

A commercial item can also be used for such ester modified hydrocarbon resin. As a commercial item of ester modified hydrocarbon resin, Quintone 1500, Quintone 1525L (all are Nippon Zeon Co., Ltd. make) etc. are mentioned, for example.

The terpene phenol resin (B) is a terpene phenol resin whose SP value is within the range of the SP value of the above-mentioned non-styrenic oligomer, and preferably, the SP value is 9.3 (cal / cm ³ ) ^1/2 It is the terpene phenol resin which is the above. The terpene phenol resin (B) is a solid at normal temperature. The terpene phenolic resin (B) is preferably used alone. The terpene phenol resin (B) is a copolymer (reactant) of a terpene compound and a phenol compound. The terpene phenol resin (B) is obtained by reacting a terpene compound and a phenol compound at 20 ° C. to 150 ° C. for 1 to 20 hours in the presence of an acidic catalyst (eg, hydrochloric acid, sulfuric acid, cation exchange resin, etc.) Be prepared.

Terpene compound is a compound having a hydrocarbon to the structural unit of isoprene (C 5 _{H 8)} as a main skeleton. As terpene compounds, for example, α-pinene, β-pinene, dipentene, limonene, α-ferandrene, β-ferandrene, α-terpinene, β-terpinene, γ-terpinene, terpinorene, myrcene, alloocimene, 1,8- Cineole, 1,4-cineole, α-terpineol, β-terpineol, γ-terpineol, 4-terpineol, sabinene, camphene, tricyclene, paramenten-1, paramenten-2, paramenten-3, paramenten-8, paramentadienes , .DELTA.2-carene, .DELTA.3-carene, karyophyllene, longifolene and the like. The terpene compounds can be used alone or in combination of two or more.

Examples of the phenol compound include phenol, cresol, xylenol, propylphenol, nonylphenol, hydroquinone, resorcin, methoxyphenol, bromophenol, bisphenol A, bisphenol F and the like. The phenol compounds can be used alone or in combination of two or more. Among the phenolic compounds, preference is given to phenol.

The range of the weight average molecular weight (Mw) of the terpene phenol resin (B) is the same as the range of the weight average molecular weight (Mw) of the non-styrenic oligomer described above. The range of the softening point of the terpene phenol resin (B) is, for example, the same as the range of the softening point of the non-styrenic oligomer described above, preferably 120 ° C. or more and 150 ° C. or less.

A commercial item can also be used for such a terpene phenol resin (B). Examples of commercially available products of the terpene phenol resin (B) include YS Polystar K-125 (manufactured by Yasuhara Chemical Co., Ltd.).

In the resin component, the content ratio of the non-styrene-based oligomer is, for example, 1% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, for example, 30% by mass or less, preferably 20% by mass It is below.

The content ratio of the non-styrene-based oligomer to the styrene-based oligomer is, for example, 0.10 or more, preferably 0.30 or more, more preferably 0.60 or more, for example, 1.5 or less, preferably 1. It is 0 or less.

If the content ratio of the non-styrene-based oligomer is not less than the above lower limit, it is possible to reliably reduce the haze value of the sealing member (described later). If the content ratio of the non-styrene-based oligomer is equal to or less than the above upper limit, the content ratio of the other resin component can be secured, and various properties required of the sealing material can be secured in a more balanced manner.

(1-5) Optional Resin Component The resin component may further contain, as an optional component, a bisphenol skeleton-containing epoxy resin having a weight average molecular weight of 800 or more and less than 10,000.

The bisphenol skeleton-containing epoxy resin has a plurality of bisphenol skeletons and a plurality of epoxy groups (a multifunctional (bifunctional) epoxy resin) and is solid at normal temperature. The bisphenol skeleton-containing epoxy resin has a lower molecular weight than the above-mentioned bisphenol skeleton-containing phenoxy resin, and a higher molecular weight than the above-mentioned alicyclic skeleton-containing epoxy resin.

Specifically, the weight average molecular weight (Mw) of the bisphenol skeleton-containing epoxy resin is 800 or more, preferably 900 or more and less than 10,000, preferably 8,000 or less.

The epoxy equivalent of the bisphenol skeleton-containing epoxy resin is, for example, 100 g / eq. Or more, preferably 150 g / eq. For example, 2,000 g / eq. Or less, preferably, 1500 g / eq. It is below.

The bisphenol skeleton-containing epoxy resin is compatible with non-styrenic oligomers, and the SP value of the bisphenol skeleton-containing epoxy resin is, for example, 11.5 (cal / cm ³ ) ^1/2 or more and 13.0 (cal / cm) ³ ) ^1/2 or less.

The bisphenol skeleton-containing epoxy resin is, for example, a copolymer of the above-mentioned bisphenol compound and epichlorohydrin, and has a molecular chain containing a plurality of bisphenol skeletons and glycidyl ether units bonded to both ends of the molecular chain. Having (bifunctional epoxy resin). Among bisphenol compounds, preferably, bisphenol F is mentioned.

The bisphenol skeleton-containing epoxy resin is contained as adjustment of the content ratio in the resin component aiming at the moldability of the seal member (described later). In the examples described later, the content ratio of the bisphenol skeleton-containing epoxy resin is such a content ratio that the total of resin components is 100 parts by mass when the content ratios of other resin components are changed (that is, the bisphenol skeleton-containing epoxy resin Content ratio = 100−sum of content ratios of other resin components).

Specifically, in the resin component, the content ratio of the bisphenol skeleton-containing epoxy resin is, for example, 5% by mass or more, preferably 15% by mass or more, for example, 40% by mass or less, preferably 30% by mass or less . When the content ratio of the bisphenol skeleton-containing epoxy resin is within the above range, the formability of the seal member (described later) can be improved.

The resin component is a specific resin component (a bisphenol skeleton-containing phenoxy resin, an alicyclic skeleton-containing epoxy resin, a styrene-based oligomer, a non-styrene-based oligomer, a bisphenol skeleton-containing epoxy resin) as long as the effects of the present invention are not impaired. Other resin components other than) can be contained.

Other resin components include, for example, other epoxy resins (for example, bisphenol skeleton-containing epoxy resins having a weight average molecular weight of less than 800), polyolefins (for example, polyethylene, polybutadiene etc.), polychloroprene, polyamide, polyamideimide, polyurethane, Polyethers, polyesters, silicone resins and the like can be mentioned. These other resin components can be used alone or in combination of two or more. In the resin component, the content ratio of the other resin component is, for example, 10% by mass or less, preferably 5% by mass or less.

(2) Curing agent The curing agent polymerizes the resin component to cure the sealing material. The curing agent is not particularly limited as long as the sealant can be cured. As a curing agent, for example, an amine-based curing agent (eg, diethylenetriamine, triethylenetetramine, tri (dimethylaminomethyl) phenol etc.), an imidazole-based curing agent (eg, 2-methylimidazole, 2-ethyl-4-methylimidazole etc.) And acid anhydride curing agents (eg, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride etc.), thermal cationic curing agents and the like. The curing agents can be used alone or in combination of two or more.

Among the curing agents, preferably, thermal cationic curing agents are mentioned. That is, the curing agent preferably contains a thermal cationic curing agent, and preferably a thermal cationic curing agent is used alone. When the curing agent contains a thermal cationic curing agent, the curing speed of the sealing material can be improved.

The thermal cationic curing agent is a thermal acid generator that generates an acid upon heating. The thermal cationic curing agent may be a compound capable of generating cations by heating and initiating polymerization of the (1-1) bisphenol skeleton-containing phenoxy resin and (1-2) alicyclic skeleton-containing epoxy resin described above. For example, the compound is preferably a compound capable of initiating polymerization at 120 ° C. or less which is a heat resistant temperature of a display element (eg, an organic EL element). As the thermal cationic curing agent, known cationic polymerization initiators can be used. As a thermal cationic polymerization initiator, for example, a sulfonium salt having, as a counter anion, AsF ₆ ⁻ , SbF ₆ ⁻ , PF ₆ ⁻ , BF ₄ ⁻ , B (C ₆ F ₅ ) ₄ ⁻ , CF ₃ SO ₃ ^{− and the} like Phosphonium salts, quaternary ammonium salts, diazonium salts, iodonium salts and the like can be mentioned.

As a sulfonium salt, for example, a boron fluoride-based sulfonium salt (eg, triphenylsulfonium tetrafluoride etc.), an arsenic fluoride-based sulfonium salt (eg, triphenylsulfonium hexafluoride arsenic, tri (4-methoxyphenyl) sulfonium Arsenic hexafluoride, diphenyl (4-phenylthiophenyl) sulfonium arsenic hexafluoride, etc., antimony fluoride-based sulfonium salt (eg, triphenylsulfonium antimony hexafluoride etc.), phosphorus fluoride-based sulfonium salt (eg, triphenylsulfone, etc.) And phenyl sulfonium hexafluorophosphate and the like.

Examples of the phosphonium salt include antimony fluoride-based phosphonium salts (eg, ethyl triphenyl phosphonium antimony hexafluoride, tetrabutyl phosphonium antimony hexafluoride, etc.).

Examples of quaternary ammonium salts include antimony fluoride quaternary ammonium salts (eg, N, N-dimethyl-N-benzylanilinium antimony pentafluoride, N, N-dimethyl-N-benzylpyridinium antimony pentafluoride) N, N-Dimethyl-N- (4-methoxybenzyl) pyridinium antimony hexafluoride, N, N-diethyl-N- (4-methoxybenzyl) pyridinium antimony hexafluoride, N, N-diethyl-N- (4 -Methoxybenzyl) toluidinium antimony hexafluoride, N, N-dimethyl-N- (4-methoxybenzyl) toluidinium antimony hexafluoride, etc., boron fluoride quaternary ammonium salt (eg, N, N-diethyl-N) -Benzylanilinium, boron tetrafluoride, etc.), organic acid quaternary ammonium salts (eg , N, etc. N- diethyl -N- benzyl pyridinium trifluoromethane sulfonate) and the like.

As an iodonium salt, for example, antimony fluoride-based iodonium salt (for example, diphenyliodonium hexafluoride antimony fluoride), phosphorus fluoride-based iodonium salt (for example, diphenyliodonium hexafluoride phosphate), boron fluoride-based iodonium salt (for example, And diphenyl iodonium boron tetrafluoride etc.).

The thermal cationic curing agent can be used alone or in combination of two or more.

Among the thermal cationic curing agents, preferably, quaternary ammonium salts are mentioned, and more preferably, antimony fluoride-based quaternary ammonium salts are mentioned.

A commercially available product can also be used as such a thermal cationic curing agent. Commercially available thermal cationic curing agents include, for example, CXC-1612, CXC-1733, CXC 1821 (all manufactured by King Industries), SunAid SI-60, SunAid SI-80, SunAid SI-B3, SunAid SI-B3A, San-Aid SI-B4 (all manufactured by Sanshin Chemical Industries, Ltd.), TA-100 (manufactured by San-Apro Co., Ltd.), etc. may be mentioned.

The content ratio of the curing agent is, for example, 0.5 parts by mass or more, preferably 1 part by mass or more, for example, 10 parts by mass or less, preferably 5 parts by mass or less with respect to 100 parts by mass of the resin component.

(3) Other Additives The sealing material can contain, as necessary, a silane coupling agent, a leveling agent and the like as other additives.

When the sealing material contains a silane coupling agent, the adhesion of the seal member (described later) to the substrate (described later) can be improved.

As a silane coupling agent, for example, an epoxy group-containing silane coupling agent (eg, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyl tri An amino group-containing silane coupling agent (eg, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyltrimethoxysilane, etc.) N-2- (aminoethyl) -3-aminopropylmethyltriethoxysilane, 3-aminopropyltrimethoxysilane, etc., methacryloyl group-containing silane coupling agent (eg, γ-methacryloxypropylmethyldimethoxysilane, γ-methacrylic acid) Roxypropyltrimethoxyki And the like. The silane coupling agents can be used alone or in combination of two or more.

Among the silane coupling agents, preferably, epoxy group-containing silane coupling agents are mentioned, and more preferably, γ-glycidoxypropyltrimethoxysilane is mentioned.

The content ratio of the silane coupling agent is, for example, 0.05 parts by mass or more, preferably 0.1 parts by mass or more, for example, 30 parts by mass or less, preferably 5 parts by mass, with respect to 100 parts by mass of the resin component. It is below.

When the sealing material contains a leveling agent, the surface of the sealing material can be smoothed when the sealing material is applied. The content ratio of the leveling agent is, for example, 0.01 parts by mass or more, preferably 0.1 parts by mass or more, for example, 5.0 parts by mass or less, preferably 1.0, with respect to 100 parts by mass of the resin component. It is below a mass part.

In addition, the sealing material may further contain, as necessary, other additives such as a filler, a polymerization initiator, an antiaging agent, a wettability improver, a surfactant, a plasticizer, an ultraviolet absorber, an antiseptic, You may contain an antibacterial agent etc. in a suitable ratio.

<Image Display Device Encapsulation Sheet>
The above-mentioned sealing material is a product that can be distributed as it is and can be used industrially, but preferably is distributed as an image display device sealing sheet from the viewpoint of handleability.

With reference to FIG. 1, the sealing sheet 1 as one Embodiment of the image display apparatus sealing sheet of this invention is demonstrated.

As shown in FIG. 1, the sealing sheet 1 includes a sealing layer 2 made of the above-described sealing material, a base film 3, and a release film 4. In addition, the sealing sheet 1 is a component for producing an image display apparatus, does not contain a display element and the board | substrate which mounts a display element, and, specifically, it separates the sealing layer 2, the base film 3, and It is a device which consists of a mold film 4 and which is distributed as a single component and which can be used industrially.

In order to prevent foreign substances from adhering to the sealing layer 2, it is preferable that the sealing layer 2 be protected by the base film 3 and the release film 4 when the sealing sheet 1 is stored. In addition, when using the sealing sheet 1, the base film 3 and the release film 4 peel.

The sealing layer 2 is a dried product of the above-described sealing material, and has a film shape (flat plate shape). Specifically, the sealing layer 2 has a predetermined thickness, extends in a predetermined direction orthogonal to the thickness direction, and has a flat surface and a flat back surface.

In the sealing layer 2, the above-mentioned epoxy components (bisphenol skeleton-containing phenoxy resin, alicyclic skeleton-containing epoxy resin, bisphenol skeleton-containing epoxy resin) do not react, and the sealing layer 2 has uncured those epoxy components. Contain in the state.

The thickness of the sealing layer 2 is, for example, 1 μm or more, preferably 5 μm or more, for example, 100 μm or less, preferably 30 μm or less.

The base film 3 is peelably attached to the back surface of the sealing layer 2 to support and protect the sealing layer 2 until the sealing sheet 1 is used to form a sealing member (described later). There is.
That is, the base film 3 is laminated on the back surface of the sealing layer 2 so as to cover the back surface of the sealing layer 2 at the time of shipment, transportation, and storage of the sealing sheet 1. It is a flexible film that can be peeled off from the back surface of the sealing layer 2 so as to be curved in a substantially U-shape.

The base film 3 has a flat plate shape, specifically, has a predetermined thickness, extends in a predetermined direction orthogonal to the thickness direction, and has a flat front surface and a flat back surface. The adhesion surface (surface) of the base film 3 is subjected to release treatment as necessary.

Examples of the material of the base film 3 include resin materials such as polyester (for example, polyethylene terephthalate (PET) and the like) and polyolefin (for example, polyethylene, polypropylene and the like), and preferably, polyethylene terephthalate is mentioned.

Among the base films 3, preferably, films having moisture barrier properties or gas barrier properties are mentioned, and more preferably, films consisting of polyethylene terephthalate are mentioned. The thickness of the base film 3 is appropriately selected depending on the material of the film, but can be, for example, about 25 μm to 150 μm from the viewpoint of having the ability to follow a material to be sealed such as a display element.

The release film 4 is peelably attached to the surface of the sealing layer 2 in order to protect the sealing layer 2 until the sealing sheet 1 is used for forming a sealing member (described later). . That is, the release film 4 is laminated on the surface of the sealing layer 2 so as to cover the surface of the sealing layer 2 at the time of shipment, transportation and storage of the sealing sheet 1, and immediately before use of the sealing sheet 1. In the above, the flexible film can be peeled off from the surface of the sealing layer 2 so as to be curved in a substantially U-shape.

The release film 4 has a flat plate shape, specifically, has a predetermined thickness, extends in a predetermined direction orthogonal to the thickness direction, and has a flat surface and a flat back surface. Moreover, the adhesion surface (back surface) of the release film 4 is exfoliated as needed. Examples of the material of the release film 4 include resin materials similar to those of the base film 3. The thickness of the release film 4 is appropriately selected depending on the material of the film, but can be, for example, about 25 μm to 150 μm, from the viewpoint of having the ability to follow a material to be sealed such as a display element.

<Method of manufacturing image display device sealing sheet>
Next, the manufacturing method of the sealing sheet 1 is demonstrated.

In order to produce the sealing sheet 1, for example, the above-described sealing material is prepared, and the sealing material is applied to the surface of the base film 3 by a known method.

The encapsulant is prepared by mixing the above-mentioned resin component, curing agent and additive in the above proportions. Moreover, in manufacture of the sealing sheet 1, a sealing material is preferably diluted with an organic solvent and the varnish of a sealing material is prepared.

The organic solvent is not particularly limited as long as the resin component and the curing agent can be uniformly dispersed or dissolved. As an organic solvent, for example, aromatic hydrocarbons (eg, benzene, toluene, xylene etc.), ketones (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone etc.), ethers (eg, dibutyl ether, tetrahydrofuran, dioxane, ethylene) Glycol monoalkyl ether, ethylene glycol dialkyl ether, 1-methoxy-2-propanol etc., esters (eg, ethyl acetate, butyl acetate etc.), nitrogen-containing compounds (eg, N-methyl pyrrolidone, dimethyl imidazolidinone, And dimethyl formaldehyde and the like. The organic solvents can be used alone or in combination of two or more.

Among the organic solvents, preferred are ketones, and more preferred is methyl ethyl ketone. When the organic solvent contains ketones, the resin component (particularly, bisphenol skeleton-containing phenoxy resin) can be uniformly dissolved.

The addition ratio of the organic solvent is, for example, 50 parts by mass or more, preferably 60 parts by mass or more, for example, 90 parts by mass or less, preferably 80 parts by mass or less with respect to 100 parts by mass of the resin component.

Each component can be mixed, for example, by dispersing with a ball mill, charging into a flask and stirring, or kneading with a three-roll mill.

Moreover, as a coating method of a sealing material, screen printing, a dispenser, an application roll etc. are mentioned, for example.

Next, the sealing material is dried, and the organic solvent is volatilized as necessary to form a coating film.

The heating temperature is a temperature at which the sealing material is dried without curing, and is, for example, 20 ° C. or more, preferably 90 ° C. or more, for example, 120 ° C. or less, preferably less than 100 ° C. The heating time is, for example, 1 minute or more, preferably 2 minutes or more, for example, 30 minutes or less, preferably 15 minutes or less.

Thereby, a coating film dries and the sealing layer 2 formed from a sealing material is prepared. Next, the release film 4 is attached to the surface of the sealing layer 2.

The sealing sheet 1 is manufactured by the above.

<Manufacture of image display device>
Next, referring to FIG. 2, FIG. 3A to FIG. 3C and FIG. 4, manufacture of an organic EL display with a touch sensor (hereinafter referred to as the organic EL display 10) as one embodiment of a method of manufacturing an image display device. The method will be described.

In addition, in this embodiment, although an organic EL display with a touch sensor is mentioned as an image display apparatus, an image display apparatus in particular is not restrict | limited. Examples of the image display device include a liquid crystal display (including a liquid crystal display with a touch sensor) and an organic EL display (including an organic EL display with a touch sensor). Among such image display devices, preferably, there are an organic EL display with a touch sensor, and more preferably, an organic EL display with a touch sensor of a capacitance type. That is, the sealing material is preferably a sealing material of the organic EL display with a touch sensor, and the sealing sheet is preferably a sealing sheet of the organic EL display with a touch sensor.

In the method of manufacturing the organic EL display 10, the step of preparing the element mounting unit 11 (see FIG. 3A), and the sealing layer 2 of the sealing sheet 1 is embedded in the organic EL element 12 covered with the barrier layer 16. Forming the sealing member 14 by curing the sealing layer 2 (see FIG. 3C), bonding the cover glass or the barrier film 15 to the sealing layer 2 (see FIG. 3C), and And (see FIG. 2).

In the method of manufacturing the organic EL display 10, first, as shown in FIG. 3A, the element mounting unit 11 is prepared. The element mounting unit 11 includes a substrate 13, an organic EL element 12 as an example of an optical element (display element), a barrier layer 16, and an electrode (not shown).

The substrate 13 supports the organic EL element 12. The substrate 13 is preferably flexible.

The organic EL element 12 is a known organic EL element and is mounted on the substrate 13. Although not shown, the organic EL element 12 includes a cathode reflection electrode, an organic EL layer, and an anode transparent electrode.

The barrier layer 16 covers the organic EL element 12 and suppresses contact of moisture in the air with the organic EL element 12. The barrier layer 16 includes a first inorganic barrier layer 17, a planarization layer 19, and a second inorganic barrier layer 18.

The first inorganic barrier layer 17 is disposed on the upper surface and the side surface of the organic EL element 12 so as to surround the organic EL element 12. Examples of the material of the first inorganic barrier layer 17 include metal oxides (for example, aluminum oxide, silicon oxide, copper oxide and the like), metal nitrides (for example, aluminum nitride, silicon nitride and the like) and the like. The materials of the first inorganic barrier layer 17 can be used alone or in combination of two or more. Among the materials of the first inorganic barrier layer 17, preferably, a metal nitride, more preferably, silicon nitride can be mentioned.

The planarization layer 19 is disposed on the top surface of the first inorganic barrier layer 17. Examples of the material of the planarization layer 19 include known resin materials.

The second inorganic barrier layer 18 is disposed on the top and side surfaces of the planarization layer 19 so as to surround the planarization layer 19. As a material of the 2nd inorganic barrier layer 18, the material similar to the 1st inorganic barrier layer 17 is mentioned, for example.

The electrodes (not shown) constitute a sensor of the organic EL display with a touch sensor. An electrode (not shown) is located between the substrate 13 and the seal member 14 (described later). For example, an electrode (not shown) may be located in the substrate 13 or may be located on the organic EL element 12.

Next, as shown by phantom lines in FIG. 1, the release film 4 is peeled off and removed from the sealing sheet 1. And as shown to FIG. 3B, after heating the sealing sheet 1 to sticking temperature, the sealing layer 2 is made to the board | substrate 13 so that the sealing layer 2 may embed the organic EL element 12 with which the barrier layer 16 was coat | covered. paste.

The sticking temperature is a temperature at which the sealing layer 2 is softened without curing, and is, for example, 40 ° C. or more, preferably 60 ° C. or more, for example, 120 ° C. or less, preferably 100 ° C. or less.

Next, as shown by phantom lines in FIG. 3B, the base film 3 is peeled and removed from the sealing layer 2. Then, as shown in FIG. 3C, a cover glass or barrier film 15 is attached to the upper surface of the sealing layer 2. Although not shown, the cover glass or barrier film 15 is provided with a glass plate, and electrodes provided on the lower surface of the glass plate to constitute a sensor of the touch sensor-attached organic EL display.

Further, as shown in FIG. 4, after the sealing layer 2 is attached to the cover glass or the barrier film 15, the sealing layer 2 may be attached to the element mounting unit 11.

Next, as shown in FIG. 2, the sealing layer 2 is heated to a curing temperature to cure the sealing layer 2 to form a sealing member 14.

The curing temperature is higher than the drying temperature described above. The curing temperature is, for example, 70 ° C. or more, preferably 80 ° C. or more, for example, 150 ° C. or less, preferably 120 ° C. or less. The curing time is, for example, 10 minutes or more, preferably 30 minutes or more, for example, 2 hours or less, preferably 60 minutes or less.

Thus, the organic EL display 10 including the element mounting unit 11, the seal member 14, and the cover glass or the barrier film 15 is manufactured. Such an organic EL display 10 is an organic EL display with a capacitive touch sensor. Further, in the organic EL display 10, an in-cell structure in which the organic EL element 12 is disposed between two electrodes constituting a sensor, or one of two electrodes constituting a sensor is disposed on the organic EL element 12 Have an on-cell structure.

The sealing member 14 is a cured product of the sealing layer 2 (sealing material), and seals the organic EL element 12 coated with the barrier layer 16.

The dielectric constant of the seal member 14 is, for example, 3.0 or more, preferably 3.2 or more, for example, less than 3.80, preferably 3.70 or less. The dielectric constant can be measured in accordance with the method described in the examples described later.

If the dielectric constant of the seal member 14 is equal to or more than the above lower limit, the degree of freedom of material selection can be improved. If the dielectric constant of the seal member 14 is equal to or less than the above-described upper limit, it is possible to suppress occurrence of malfunction in an organic EL display with a touch sensor or the like.

The haze value of the seal member 14 is, for example, 0.1 or more, for example, less than 2.0%, preferably 1.5% or less, more preferably less than 1.0. The haze value can be measured according to the method described in the examples described later.

If the haze value of the seal member 14 is equal to or less than the above-described upper limit, the visibility of the display (including the display with a touch sensor) can be improved.

The moisture permeability of the sealing member 14 is, for example, 20 g / m ² · 24 h or more, for example 50 g / m ² · 24 h or less, preferably less than 45 g / m ² · 24 h, more preferably 40 g / m ² · 24 h or less It is. In addition, moisture permeability can be measured based on the method as described in the Example mentioned later.

If the moisture permeability of the seal member 14 is equal to or less than the above-described upper limit, deterioration of the optical element sealed by the seal member 14 can be suppressed.

<Function effect>
However, the seal member of the liquid crystal display is, for example, provided in a frame shape so as to surround the periphery of the liquid crystal disposed between the substrate and the glass plate. On the other hand, as shown in FIG. 2, the seal member of the organic EL display is provided so that the organic EL element is embedded therein. Therefore, the seal member of the organic EL display is more affected by the dielectric constant than the seal member of the liquid crystal display, and it is desirable to reduce the dielectric constant.

On the other hand, the seal member of the organic EL display is not required to have a dielectric constant as low as that required for a seal member of a normal semiconductor component.

The present inventors have added to the resin component of the encapsulant a styrene-based oligomer generally used as a tackifier, and a bisphenol skeleton by adding a non-styrene-based oligomer having an SP value of the above lower limit or more. Containing a phenoxy resin, an alicyclic skeleton-containing epoxy resin, a styrene-based oligomer, and a non-styrene-based oligomer, and the dielectric constant of the sealing member formed from the sealing material, the image display device, In particular, it has been found that it can be adjusted to the range required for the organic EL display. Furthermore, it has also been found that when a styrene-based oligomer and a non-styrene-based oligomer are added to the resin component, high transparency can be secured while the dielectric constant can be reduced in the seal member.

In the sealing material described above, since the resin component contains a styrene-based oligomer and a non-styrene-based oligomer, in the sealing member, the dielectric constant can be reduced to the range required for the image display device (particularly, organic EL display). The high transparency required for the display device (particularly, the organic EL display) can be secured.

The non-styrenic oligomer is preferably an aliphatic hydrocarbon resin and / or a terpene phenol resin. Therefore, while the dielectric constant of the seal member can be reliably reduced, the haze of the seal member can be reliably reduced.

Moreover, as shown in FIG. 1, the sealing sheet 1 has the sealing layer 2 which consists of sealing materials. Therefore, the handleability of the sealing material can be improved. Further, in the sealing member, high transparency can be ensured while the dielectric constant can be reduced.

<Modification>
In a modification, about the member and process similar to said embodiment, the same referential mark is attached | subjected and the detailed description is abbreviate | omitted.

Although the sealing sheet 1 is provided with the sealing layer 2, the base film 3, and the release film 4 as shown in FIG. 1, the image display device sealing sheet of this invention is not limited to this. The image display device sealing sheet may not have the base film 3 and / or the release film 4 if it has the sealing layer 2. That is, the image display device sealing sheet may be constituted only by the sealing layer 2, or may be provided with the sealing layer 2 and any one of the base film 3 and the release film 4.

As shown in FIG. 2, the organic EL display 10 includes the barrier layer 16, but is not limited thereto. The organic EL display 10 may not include the barrier layer 16.

Further, in the organic EL display 10, an in-cell structure in which the organic EL element 12 is disposed between two electrodes constituting a sensor, or one of the two electrodes is disposed on the organic EL element 12 Although it has an on-cell structure, it is not limited to this.

For example, as shown in FIG. 5, the organic EL display 20 may have an out-cell structure in which two electrodes constituting a sensor are disposed above the seal member 14. The organic EL display 20 includes the element mounting unit 11 described above, the seal member 14 described above, and the sensor unit 25.

The sensor unit 25 includes a glass substrate 23, an adhesive layer 21, and a cover glass 22. The glass substrate 23 is disposed on the top surface of the seal member 14. The glass substrate 23 is provided with an electrode which constitutes a sensor of the organic EL display with a touch sensor. The adhesive layer 21 is disposed between the glass substrate 23 and the cover glass 22 and bonds the glass substrate 23 and the cover glass 22. The cover glass 22 is disposed on the upper side of the adhesive layer 21. The cover glass 22 includes an electrode that constitutes a sensor of the touch sensor-attached organic EL display. In the organic EL display 20, the substrate 13 does not have an electrode.

The same effects as those of the above-described embodiment can be obtained for each of the above-described modifications. The above embodiments and modifications can be combined as appropriate.

Although an example is shown below and the present invention is explained still more concretely, the present invention is not limited to them. Specific numerical values such as blending ratios (content ratios), physical property values, parameters, etc. used in the following description are the blending ratios (content ratios) corresponding to those described in the above-mentioned "embodiments for carrying out the invention" ), Physical property values, parameters, etc. may be substituted for the upper limit (numerical values defined as “below”, “less than”) or lower limit (numerical values defined as “above”, “exceed”), etc. it can. In addition, "part" and "%" are mass references | standards unless there is particular mention.

Examples 1 to 4
Bisphenol skeleton-containing phenoxy resin (trade name: JER-4275, manufactured by Mitsubishi Chemical Corporation, bisphenol A skeleton [structural unit II in which ^two R ² are methyl groups in the above formula (1)] and bisphenol F skeleton [the above formula (1 In which two R ² are hydrogen atoms, weight average molecular weight: about 60,000, epoxy equivalent weight: 8,400 to 92,00 g / eq.), And bisphenol skeleton-containing epoxy resin (commodity Name: JER-4005P, manufactured by Mitsubishi Chemical Corporation, weight average molecular weight: 6,200, epoxy equivalent: 1070 g / eq.), And ECH structure-containing epoxy compound (trade name: Celoxide 2021 P, 3,4-epoxycyclohexylmethyl (3) , 4-Epoxy) cyclohexanecarboxylate, molecular weight: 252.3, d X-equivalent weight: 128 to 145 g / eq.), Styrene-based oligomer (homopolymer of isopropenyl toluene (IPT), weight average molecular weight: 1200), ester-modified hydrocarbon resin (non-styrene-based oligomer, SP value 9.) 0, trade name: Quintone 1500, manufactured by Nippon Zeon, weight average molecular weight: 750), thermal cation initiator (trade name: CXC-1612, manufactured by King Industries), and methyl ethyl ketone (organic solvent) are shown in Table 1 It mixed by the prescription shown and prepared the varnish of the sealing material.

Example 5
A varnish for a sealing material was prepared in the same manner as in Example 4 except that the amount of the ECH structure-containing epoxy compound added was changed to 40 parts by mass, and that the bisphenol skeleton-containing epoxy resin was not added.

Example 6
Example 4 is the same as Example 4 except that the ECH structure-containing epoxy compound is changed to a DCPD type epoxy resin (trade name: EP-4088S, manufactured by ADEKA, weight average molecular weight: 308.2, epoxy equivalent: 170 g / eq.). Similarly, a varnish of a sealing material was prepared.

Examples 7-9
In the same manner as in Examples 1 to 3, except that the ester-modified hydrocarbon resin is changed to a terpene phenol resin (non-styrene-based oligomer, trade name: YS Polystar K 125, manufactured by Yasuhara Chemical Co., Ltd.) having an SP value of 9.3. A varnish of the encapsulant was prepared.

Example 10
The varnish of the encapsulating material was prepared in the same manner as in Example 9 except that the amount of the styrene-based oligomer added was changed to 10 parts by mass, and the amount of the bisphenol skeleton-containing epoxy resin added was changed to 25 parts by mass. Prepared.

Comparative Example 1
Bisphenol skeleton-containing phenoxy resin (trade name: JER-4275, manufactured by Mitsubishi Chemical Corporation), bisphenol skeleton-containing epoxy resin (trade name: JER4005P, manufactured by Mitsubishi Chemical Corporation), and aromatic ring skeleton-containing epoxy resin (trade name: YL- 983 U, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 169 g / eq., Weight average molecular weight: 326.2), thermal cation initiator (trade name: CXC-1612, manufactured by King Industries), and methyl ethyl ketone (organic solvent) Were mixed according to the formulation shown in Table 1 to prepare a varnish of a sealing material.

Comparative example 2
A varnish of a sealing material was prepared in the same manner as in Comparative Example 1 except that the aromatic ring skeleton-containing epoxy resin was changed to an ECH structure-containing epoxy compound (trade name: Celoxide 2021 P).

Comparative example 3
Addition of 25 parts by mass of a styrene-based oligomer (homopolymer of isopropenyl toluene (IPT), weight average molecular weight: 1200), and changing the amount of the bisphenol skeleton-containing epoxy resin to 25 parts by mass Then, in the same manner as in Comparative Example 2, a varnish of a sealing material was prepared.

Comparative example 4
25 parts by mass of ester-modified hydrocarbon resin (non-styrene-based oligomer, SP value 9.0, trade name: Quintone 1500, manufactured by Nippon Zeon Co., Ltd.) and 25 parts by mass of the bisphenol skeleton-containing epoxy resin A varnish of a sealing material was prepared in the same manner as in Comparative Example 2 except for changing to.

Comparative example 5
Sealing was performed in the same manner as in Comparative Example 4 except that the ester-modified hydrocarbon resin was changed to a terpene phenol resin (non-styrene-based oligomer, trade name: YS Polystar K 125, manufactured by Yasuhara Chemical Co., Ltd.) having an SP value of 9.3. A wood varnish was prepared.

Comparative example 6
15 parts by mass of styrene oligomer (isopropenyl toluene (IPT) homopolymer, weight average molecular weight: 1200), ester-modified hydrocarbon resin (non-styrene oligomer, SP value 9.0, trade name: Quintone 1500, Nippon Zeon A varnish of a sealing material was prepared in the same manner as in Comparative Example 1 except that 10 parts by mass of product made in the same manner was further added.

Comparative example 7
Varnish of sealing material in the same manner as in Example 4 except that the ester-modified hydrocarbon resin was changed to an aromatic-modified hydrocarbon resin (SP value 8.5, trade name: Quintone 1920, manufactured by Nippon Zeon Co., Ltd.) Was prepared.

Comparative Example 8
A varnish of a sealing material was prepared in the same manner as in Example 4, except that the ester-modified hydrocarbon resin was changed to a hydrogenated terpene resin (SP value 8.4, trade name: Clearon P-105, manufactured by Yasuhara Chemical Co., Ltd.) Was prepared.

Comparative Example 9
A sealing material was prepared in the same manner as in Example 4, except that the ester-modified hydrocarbon resin was changed to a hydrogenated aromatic terpene resin (SP value 8.5, trade name: Clearon M-105, manufactured by Yasuhara Chemical Co., Ltd.) The varnish of was prepared.

Comparative example 10
A sealing material was prepared in the same manner as in Example 4, except that the ester-modified hydrocarbon resin was changed to a rosin ester resin (SP value 8.5, trade name: Pine Crystal KE-100, manufactured by Arakawa Chemical Industries, Ltd.) The varnish of was prepared.

Comparative example 11
A sealing material was prepared in the same manner as in Example 4, except that the ester-modified hydrocarbon resin was changed to a rosin resin (SP value 8.4, trade name: Pine Crystal KR-85, manufactured by Arakawa Chemical Industries, Ltd.). A varnish was prepared.

Comparative Example 12
A sealing material is prepared in the same manner as in Example 10 except that the terpene phenol resin having an SP value of 9.3 is changed to a terpene phenol resin having an SP value of 8.8 (trade name: YS Polystar T130, manufactured by Yasuhara Chemical Co., Ltd.) The varnish of was prepared.

Comparative Example 13
A sealing material is prepared in the same manner as in Example 10 except that the terpene phenol resin having an SP value of 9.3 is changed to a terpene phenol resin having an SP value of 8.8 (trade name: YS Polystar T160, manufactured by Yasuhara Chemical Co., Ltd.) The varnish of was prepared.

<Evaluation>
-Permittivity The varnish of the sealing material of each example and each comparative example is a PET film (PET film (trade name: Purex A53, manufactured by Teijin DuPont Films, manufactured by Teijin Dupont, Inc., thickness: 38 μm) treated by a coating machine with a varnish of a sealing material And the base film were dried at 90.degree. C. for 3 minutes in a nitrogen purge oven to form a 15 .mu.m-thick sealing layer.

Then, a PET film (a release-treated PET film (trade name: Purex A31, manufactured by Teijin DuPont Films, thickness: 38 μm, release film) was laminated at 80 ° C. to the sealing layer using a thermal laminator .

By the above, the sealing sheet provided with a base film, a sealing layer, and a mold release film was prepared. This was repeated, and two sealing sheets were prepared for each of the example and the comparative example. And in each of two sealing sheets corresponding to the same example or comparative example, after peeling a release film from a sealing layer, two sealing layers are pasted together in a thickness direction, and those thickness Is 30 μm.

Next, after peeling off the base film on one side and curing the two sealing layers bonded to each other for one hour at 100 ° C., the base film on the other side is peeled off from the sealing layer after curing and for measurement I got a sample. The dielectric constant at 100 kHz of the obtained sample was measured by an automatic balance bridge method using an LCR meter HP4284A (manufactured by Agilent Technologies).

And the dielectric constant was evaluated by the following reference | standard. The results are shown in Tables 1 and 2.
○: less than 3.80 ×: 3.80 or more.

-Haze value It carried out similarly to evaluation of said dielectric constant, and prepared the sealing sheet of each Example and each comparative example. And after peeling a release film from a sealing layer, the sealing layer was hardened at 100 degreeC for 1 hour.
Next, the base film was peeled off from the cured sealing layer to obtain a measurement sample. The haze value of the obtained sample was measured using a haze meter NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd.

And the haze value was evaluated by the following reference | standard. The results are shown in Tables 1 and 2.
○: less than 2.0% ×: 2.0% or more.

Moisture Permeability Sealing sheets of Examples and Comparative Examples were prepared in the same manner as the evaluation of the dielectric constant described above. And after peeling a release film from a sealing layer, the sealing layer was hardened at 100 degreeC for 1 hour.
Next, the base film was peeled off from the cured sealing layer to obtain a measurement sample. The moisture permeability (moisture permeability) of the obtained sample was measured under the conditions of 60 ° C. and 90% RH in accordance with JIS Z0208. Then, it converted into the value in case the thickness of a sample is 100 micrometers from the film thickness of the sample used for measurement.

And, the moisture permeability was evaluated according to the following criteria. The results are shown in Tables 1 and 2.
○: less than 45 g / m ² · 24 h Δ: 45 g / m ² · 24 h or more.

Although the above invention is provided as an exemplary embodiment of the present invention, this is merely an example and should not be interpreted in a limited manner. Variations of the invention that are apparent to those skilled in the art are within the scope of the following claims.

The image display device sealing material and the image display device sealing sheet of the present invention are suitably used as a sealing material of various image display devices, specifically, a sealing material of a liquid crystal display, an organic EL display and the like.

1 Sealing sheet 2 Sealing layer

Claims (7)

Containing resin component and curing agent,
The resin component is
A bisphenol skeleton-containing phenoxy resin having a weight average molecular weight of 10,000 or more and 100,000 or less,
An alicyclic skeleton-containing epoxy resin having a weight average molecular weight of 180 or more and 790 or less;
Styrene-based oligomers having a weight average molecular weight of 750 or more and 4000 or less,
An image display apparatus comprising: a non-styrenic oligomer having a weight average molecular weight of 500 or more and less than 10,000 and a solubility parameter of 8.9 (cal / cm ³ ) ^1/2 or more. Stopper. The non-styrenic oligomer according to claim 1, wherein the non-styrenic oligomer is an aliphatic hydrocarbon resin and / or a terpene phenol resin having a solubility parameter of 8.9 (cal / cm ³ ) ^1/2 or more. Image display device sealing material. In the said resin component, the content rate of the said non-styrene-type oligomer is 10 mass% or more, The image display apparatus sealing material of Claim 1 characterized by the above-mentioned. The image display device sealing material according to claim 1, wherein the content ratio of the non-styrene-based oligomer to the styrene-based oligomer is 0.60 or more. In the said resin component, the content rate of the said styrene-type oligomer exceeds 10 mass%, The image display apparatus sealing material of Claim 1 characterized by the above-mentioned. In the said resin component, the content rate of the said alicyclic skeleton containing epoxy resin is less than 40 mass%, The image display apparatus sealing material of Claim 1 characterized by the above-mentioned. An image display device sealing sheet comprising the image display device sealing material according to claim 1.

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