JP7099441B2 - Sealing sheet - Google Patents

Description

The present invention relates to a sealing sheet, and more particularly to a sealing sheet capable of forming a highly moisture-proof sealing structure by itself.

An organic EL (Electroluminescence) element is a light emitting element that uses an organic substance as a light emitting material, and has been in the limelight in recent years because it can obtain high-luminance light emission at a low voltage. However, the organic EL element is extremely sensitive to moisture, and the light emitting material (light emitting layer) is altered by the water, and the brightness is lowered or the light is not emitted, or the interface between the electrode and the light emitting layer is peeled off due to the influence of water. There is a problem that the metal oxidizes and becomes highly resistant. Therefore, in order to block the inside of the device from moisture in the outside air, for example, a sealing layer made of a resin composition is formed so as to cover the entire surface of the light emitting layer of the organic EL device formed on the substrate, and the organic EL is formed. Sealing of the element is performed.

As such a resin composition for encapsulation, for example, Patent Document 1 describes a polyisoprene resin, a polyisoprene resin having a functional group capable of reacting with an epoxy group and / or a polyisoprene resin, a tackifier resin, and an epoxy. A resin composition containing a resin is disclosed. Further, Patent Document 2 discloses a resin composition containing a styrene-isobutylene-modified resin and a tackifier resin. Further, in order to enhance the moisture permeability of the sealing layer, a hygroscopic filler may be added to the resin composition.

Sealing of an organic EL element with such a resin composition may be performed by a sealing sheet having a resin composition layer formed on a support from the viewpoints of productivity, sealing workability, and the like. In addition, in order to form a highly moisture-proof sealing structure, not only the moisture-permeable resistance of the resin composition layer is enhanced, but also a moisture-proof support or a sealing base material may be used.

International Publication No. 2011/62167 International Publication No. 2013/108731

When sealing the organic EL element with a sealing sheet, if the support of the sealing sheet is a support having moisture resistance, the sealing sheet is placed on a substrate having an organic EL element in a resin composition layer. After laminating so as to cover the organic EL element, the encapsulation step of the organic EL element is completed as it is without peeling off the support. If thermosetting is required after the sealing process, thermosetting is performed.

On the other hand, when a sealing sheet using a support having no moisture resistance is used, the sealing sheet is laminated on the substrate having the organic EL element so that the resin composition layer covers the organic EL element, and then the sealing sheet is laminated. The encapsulation step of the organic EL element is completed by peeling off the support and crimping the encapsulating base material to the exposed resin composition layer. In order to improve the moisture-proof effect, the sealing base material may be used by laminating two or more sheets.

Usually, as the above-mentioned moisture-proof support and sealing base material, a moisture-proof plastic film, a metal foil such as a copper foil or an aluminum foil, or the like is used. Examples of the moisture-proof plastic film include a plastic film in which an inorganic substance such as SiO ₂ , SiN, SiCN, and amorphous silicon is vapor-deposited on the surface.

By the way, recently, with the expansion of the demand for organic EL devices, it is desired to reduce the thickness of the organic EL device, but the support having the moisture-proof property and the sealing base material hinder the thinning.

The present invention has been made in view of the above circumstances, and the problem to be solved thereof is to form a sealing structure having high moisture resistance without including a sealing base material or a moisture proof support. To obtain, to provide a sealing sheet.

The configuration of the present invention for solving the above problems is as follows.

[1] A sealing sheet containing (A) a pressure-sensitive adhesive resin composition layer and (B) a moisture-proof inorganic film directly formed on one side of the (A) pressure-sensitive adhesive resin composition layer.
[2] The above-mentioned [1], wherein the (B) moisture-proof inorganic film is a silica glass film made of (B1) a heat-treated product of a polysilazane-containing coating film, or (B2) an inorganic vapor-deposited film. Sealing sheet.
[3] The sealing sheet according to the above [2], wherein the polysilazane contains perhydroxypolysilazane.
[4] (B2) The sealing sheet according to the above [2], wherein the inorganic vapor-deposited coating is a silicon compound vapor-deposited coating.
[5] The sealing sheet according to the above [4], wherein the silicon compound vapor deposition film is a SiO ₂ -SiCN multilayer vapor deposition film containing a SiO ₂ vapor deposition film and a SiCN vapor deposition film.
[6] The sealing sheet according to the above [5], wherein the SiO ₂ -SiCN multi-layer vapor deposition film is a SiO ₂ -SiCN multi-layer vapor deposition film in which a SiO ₂ -vapor film and a SiCN vapor-film film are alternately formed.
[7] (B) The sealing sheet according to any one of the above [1] to [6], wherein the moisture-proof inorganic coating has a thickness of 1000 nm or less.
[8] (A) The sealing sheet according to any one of the above [1] to [7], wherein the pressure-sensitive adhesive resin composition layer has a thickness of 3 to 50 μm.
[9] The sealing sheet according to any one of the above [1] to [8], wherein the pressure-sensitive adhesive resin composition layer contains a hygroscopic filler.
[10] The sealing sheet according to any one of the above [1] to [9], wherein the pressure-sensitive adhesive resin composition layer contains a tackifier resin.
[11] A laminated structure of (C) a support that has been mold-released, (C) a support that has been mold-released / (A) a pressure-sensitive adhesive resin composition layer / (B) a moisture-proof inorganic film. The sealing sheet according to any one of the above [1] to [10].
[12] (C) The sealing sheet according to the above [11], wherein the release-treated support is a support having a moisture-proof property.
[13] The sealing sheet according to any one of the above [1] to [12], which is used for sealing an organic EL element.
[14] (B) A circularly polarizing plate is further adhered to the surface of the moisture-proof inorganic film on the side opposite to the side of the (A) pressure-sensitive adhesive resin composition layer, and the organic EL element is sealed. The sealing sheet according to any one of the above [1] to [10], which is a sheet for sealing.
[15] (B) A circularly polarizing plate is further adhered to the surface of the moisture-proof inorganic film on the side opposite to the side of the (A) pressure-sensitive adhesive resin composition layer, and the organic EL element is sealed. The sealing sheet according to the above [11] or [12], which is a sheet for sealing.
[16] An organic EL device in which an organic EL element is sealed with the sealing sheet according to any one of the above [1] to [10] and [14].
[17] Does it include a step of forming a polysilazane-containing coating film on one side of the (A) pressure-sensitive adhesive resin composition layer and heating the coating film in a steam-containing atmosphere to (B1) convert it into a silica glass coating film? Alternatively, a method for producing a sealing sheet, comprising (A) depositing an inorganic substance on one side of the pressure-sensitive adhesive resin composition layer and (B2) forming an inorganic vapor-deposited film.

According to the sealing sheet of the present invention, it is possible to form a sealing structure having high moisture-proof properties without including a sealing base material or a moisture-proof support, so that the sealing structure can be made thin. can. Therefore, for example, by using the sealing sheet of the present invention for sealing an organic EL element, a thin organic EL device can be obtained.

It is a schematic sectional view of the sealing sheet by one Embodiment of this invention. It is a schematic sectional drawing of the sealing sheet by another embodiment of this invention.

FIG. 1 is a diagram schematically showing a cross section of a sealing sheet according to an embodiment of the present invention.
The sealing sheet of the present invention has (A) a pressure-sensitive adhesive resin composition layer 1 and (A) a pressure-sensitive adhesive resin composition layer, as shown in the sealing sheet 10 of the above embodiment. (B) Moisture-proof inorganic coating 2 directly formed on one side of the above is contained.

Typically, the encapsulating sheet of the present invention further comprises (C) the release-treated support 3 as shown in FIG. 1 and (C) the release-treated support 3 / ( A) A sheet having a laminated structure of a pressure-sensitive adhesive resin composition layer 1 / (B) a moisture-proof inorganic coating 2.

The support 3 (C) released from the mold is a support for forming (A) the pressure-sensitive adhesive resin composition layer 1, and before actually sealing the sealing target, (C) A) It is peeled off from the pressure-sensitive adhesive resin composition layer 1. Therefore, the release-treated support 3 does not necessarily have moisture-proof property, but the sealing sheet is stored during the storage period from the production of the sealing sheet to the sealing operation ( A) From the viewpoint of preventing the infiltration of water into the pressure-sensitive adhesive resin composition layer 1, a support having moisture resistance can be used as the support 3 which has been subjected to the mold release treatment (C).

Hereinafter, each component of the sealing sheet will be described in detail.
[(A) Pressure-sensitive adhesive resin composition layer]
(A) The pressure-sensitive adhesive resin composition layer 1 is a layer for forming a sealing layer adhered to a sealing target by laminating a sealing sheet on a sealing target such as an organic EL element. It is formed by a pressure-adhesive resin composition.

(A) Pressure-sensitive adhesive resin composition The pressure-sensitive adhesive resin composition (hereinafter, also simply referred to as “resin composition”) forming the pressure-sensitive adhesive resin composition layer 1 is preferably a resin composition having adhesiveness and moisture absorption. For example, a resin composition containing (a) a polyolefin-based resin, (b) an adhesive resin, and (c) a hygroscopic filler can be mentioned. Since the pressure-sensitive adhesive resin composition layer 1 (A) has hygroscopicity, it is possible to effectively prevent the arrival of moisture at the sealing target.

<(A) Polyolefin-based resin>
The (a) polyolefin resin (hereinafter, also abbreviated as “component (a)”) is not particularly limited as long as it has a skeleton derived from an olefin monomer. For example, examples of the polyolefin-based resin include polyethylene-based resin, polypropylene-based resin, polybutene-based resin, and polyisobutylene-based resin.

The polyolefin-based resin may be a homopolymer, a random copolymer, or a block copolymer. Examples of the copolymer include (i) a copolymer of two or more types of olefins, (ii) a copolymer of an olefin and a non-conjugated diene, or (iii) an olefin and a monomer other than an olefin such as methyl methacrylate or styrene. Examples include polymers (excluding non-conjugated diene). In the copolymer of (ii) and the copolymer of (iii), one kind or two or more kinds of olefins can be used.

Preferred examples of homopolymers include, for example, polybutene. Preferred examples of copolymers are ethylene-non-conjugated diene copolymer, ethylene-propylene copolymer, ethylene-butene-non-conjugated diene copolymer, ethylene-propylene-non-conjugated diene copolymer, ethylene-propylene-. Butene copolymer, propylene-butene copolymer, propylene-butene-non-conjugated diene copolymer, isobutylene-butene copolymer, isobutylene-butene-non-conjugated diene copolymer, styrene-isobutylene copolymer, styrene- Examples thereof include an isobutylene-styrene copolymer and an ethylene-methylmethacrylate copolymer.

The polyolefin-based resin has an acid anhydride group (that is, a carbonyloxycarbonyl group (that is, a carbonyloxycarbonyl group) from the viewpoint of imparting excellent physical properties such as adhesion of the resin composition layer to the object to be sealed and adhesion wet heat resistance of the resin composition layer. A polyolefin-based resin having —CO—CO—)) and / or a polyolefin resin having an epoxy group can be included. Examples of the acid anhydride group include a group derived from succinic anhydride, a group derived from maleic anhydride, a group derived from glutaric anhydride and the like. The acid anhydride group can have one kind or two or more kinds. The polyolefin-based resin having an acid anhydride group is, for example, an unsaturated compound having an acid anhydride group, and can be obtained by graft-modifying the polyolefin resin under radical reaction conditions. Further, an unsaturated compound having an acid anhydride group may be radically copolymerized together with an olefin or the like. Similarly, the polyolefin resin having an epoxy group is an unsaturated compound having an epoxy group such as glycidyl (meth) acrylate, 4-hydroxybutyl acrylate glycidyl ether, and allyl glycidyl ether, and the polyolefin resin is subjected to radical reaction conditions. It is obtained by graft modification at. Further, the unsaturated compound having an epoxy group may be radically copolymerized together with an olefin or the like.

As the polyolefin-based resin having an acid anhydride group, for example, liquid polybutene having an acid anhydride group is preferable, and maleic anhydride-modified liquid polybutene is more preferable. As the polyolefin-based resin having an epoxy group, for example, epoxy-modified polyethylene having an epoxy group, epoxy-modified polypropylene, epoxy-modified polybutene and the like are preferable.

The concentration of the acid anhydride group in the polyolefin resin having an acid anhydride group is preferably 0.05 to 10 mmol / g, more preferably 0.1 to 5 mmol / g. The concentration of the acid anhydride group is obtained from the value of the acid value defined as the number of mg of potassium hydroxide required to neutralize the acid present in 1 g of the resin according to the description of JIS K 2501. The amount of the polyolefin-based resin having an acid anhydride group in the component (a) is preferably 0 to 70% by mass, more preferably 10 to 50% by mass.

The concentration of the epoxy group in the polyolefin resin having an epoxy group is preferably 0.05 to 10 mmol / g, more preferably 0.1 to 5 mmol / g. The epoxy group concentration is determined from the epoxy equivalent obtained based on JIS K 7236-1995. The amount of the polyolefin-based resin having an epoxy group in the component (a) is preferably 0 to 70% by mass, more preferably 10 to 50% by mass.

(A) The number average molecular weight of the components is not particularly limited, but is 1,000 from the viewpoint of providing good coatability of the varnish of the resin composition and good compatibility with other components in the resin composition. 000 or less is preferable, 750,000 or less is more preferable, 500,000 or less is further preferable, 400,000 or less is further preferable, 300,000 or less is further preferable, 200,000 or less is particularly preferable, 150, Most preferably 000 or less. On the other hand, from the viewpoint of preventing repelling during coating of the varnish of the resin composition, developing the moisture permeability of the formed resin composition layer, and improving the mechanical strength, 2,000 or more is preferable. 000 or more is more preferable, 30,000 or more is even more preferable, and 50,000 or more is particularly preferable. The number average molecular weight is measured by a gel permeation chromatography (GPC) method (polystyrene conversion). Specifically, for the number average molecular weight by the GPC method, LC-9A / RID-6A manufactured by Shimadzu Corporation is used as a measuring device, and Polystyrene K-800P / K-804L / K-804L manufactured by Showa Denko Corporation is used as a column. It can be measured at a column temperature of 40 ° C. using toluene or the like as a phase, and can be calculated using a standard polystyrene calibration curve.

As one of the preferred embodiments of the component (a), a liquid polyolefin having a number average molecular weight of 1000 or more and 3000 or less (preferably liquid polybutene and / or maleic anhydride-modified liquid polybutene) is used in an amount of 10 mass of the entire component (a). Examples thereof include an embodiment containing% or more and 90% by mass or less. When the component (a) is in such a preferred embodiment, high adhesive strength is likely to be obtained.

The polyolefin-based resin (a) in the present invention is preferably amorphous from the viewpoint of suppressing a decrease in fluidity due to thickening of the varnish. Here, amorphous means that the polyolefin-based resin does not have a clear melting point, and for example, when the melting point is measured by DSC (differential scanning calorimetry) of the polyolefin-based resin, no clear peak is observed. You can use things.

(A) The component may be used alone or in combination of two or more. The content of the component (a) in the resin composition is not particularly limited. However, from the viewpoint of providing good coatability and compatibility, and ensuring good wet and heat resistance and handleability (tack suppression), the content is per 100% by mass of the total non-volatile content in the resin composition. 80% by mass or less is preferable, 75% by mass or less is more preferable, 70% by mass or less is further preferable, 60% by mass or less is further preferable, 55% by mass or less is further preferable, and 50% by mass or less is particularly preferable. On the other hand, from the viewpoint of improving moisture permeability and transparency, the content is preferably 1% by mass or more, more preferably 3% by mass or more, per 100% by mass of the total non-volatile content in the resin composition. Preferably, 5% by mass or more is further preferable, 7% by mass or more is further preferable, 10% by mass or more is further preferable, 35% by mass or more is particularly preferable, and 40% by mass or more is most preferable.

Next, a specific example of (a) the polyolefin-based resin will be described. Specific examples of the polyisobutylene resin include "Opanol B100" manufactured by BASF (viscosity average molecular weight: 1,110,000) and "B50SF" manufactured by BASF (viscosity average molecular weight: 400,000).

Specific examples of the polybutene resin include "HV-1900" (polybutene, number average molecular weight: 2,900) manufactured by JX Energy Co., Ltd. and "HV-300M" (maleic anhydride-modified liquid polybutene) manufactured by Toho Kagaku Kogyo Co., Ltd. ("HV"). -300 ”(modified product with number average molecular weight: 1,400), number average molecular weight: 2,100, number of carboxy groups constituting the acid anhydride group: 3.2 / 1 molecule, acid value: 43. 4 mgKOH / g, acid anhydride group concentration: 0.77 mmol / g).

Specific examples of the styrene-isobutylene copolymer include "SIBSTAR T102" manufactured by Kaneka (styrene-isobutylene-styrene block copolymer, number average molecular weight: 100,000, styrene content: 30% by mass), manufactured by Seikou PMC. "T-YP757B" (maleic anhydride-modified styrene-isobutylene-styrene block copolymer, acid anhydride group concentration: 0.464 mmol / g, number average molecular weight: 100,000), "T-YP766" manufactured by Seikou PMC. (Glysidyl methacrylate-modified styrene-isobutylene-styrene block copolymer, epoxy group concentration: 0.638 mmol / g, number average molecular weight: 100,000), "T-YP8920" manufactured by Seikou PMC (maleic anhydride-modified styrene-isobutylene) -Styrene copolymer, acid anhydride group concentration: 0.464 mmol / g, number average molecular weight: 35,800), "T-YP8930" manufactured by Seikou PMC (glycidyl methacrylate-modified styrene-isobutylene-styrene copolymer, epoxy) Group concentration: 0.638 mmol / g, number average molecular weight: 48,700).

Specific examples of the polyethylene-based resin or polypropylene-based resin include "EPT X-3012P" manufactured by Mitsui Chemicals, Inc. (ethylene-propylene-5-ethylidene-2-norbornene copolymer, "EPT1070" manufactured by Mitsui Chemicals, Inc. (ethylene-propylene). -Dicyclopentadiene copolymer), "Toughmer A4085" (ethylene-butene copolymer) manufactured by Mitsui Chemicals, Inc., and the like.

As a specific example of the ethylene-methylmethacrylate copolymer, "ACRYFT CM5022" manufactured by Sumitomo Chemical Co., Ltd. (ethylene-methylmethacrylate copolymer, amount of methylmethacrylate units per 100% by mass of ethylene units and methylmethacrylate units: 33). (% by mass), "T-YP429" manufactured by Seikou PMC (maleic anhydride-modified ethylene-methylmethacrylate copolymer, amount of methylmethacrylate units per 100% by mass of ethylene units and methylmethacrylate units: 32% by mass, acid Anhydrous group concentration: 0.46 mmol / g, number average molecular weight: 2,300), "T-YP430" manufactured by Seikou PMC (maleic anhydride-modified ethylene-methylmethacrylate copolymer, total of ethylene units and methylmethacrylate units) Amount of methyl methacrylate unit per 100% by mass: 32% by mass, acid anhydride group concentration: 1.18 mmol / g, number average molecular weight: 4,500), Starlight PMC "T-YP431" (glycidyl methacrylate-modified ethylene) -Methyl methacrylate copolymer, epoxy group concentration: 0.64 mmol / g, number average molecular weight: 2,400), "T-YP432" manufactured by Seikou PMC (glycidyl methacrylate-modified ethylene-methyl methacrylate copolymer, epoxy group concentration) : 1.63 mmol / g, number average molecular weight: 3,100). As a specific example of the propylene-butene-based copolymer, "T-YP341" manufactured by Seikou PMC (glycidyl methacrylate-modified propylene-butene random copolymer, butene unit per 100% by mass of propylene unit and butene unit in total). Amount: 29% by mass, epoxy group concentration: 0.638 mmol / g, number average molecular weight: 155,000), "T-YP279" manufactured by Seikou PMC (maleic anhydride-modified propylene-butene random copolymer, propylene unit). Amount of butene unit per 100% by mass of total butene unit: 36% by mass, acid anhydride group concentration: 0.464 mmol / g, number average polymer weight: 35,000), "T-YP276" manufactured by Seikou PMC Co., Ltd. ( Glycidyl methacrylate-modified propylene-butene random copolymer, amount of butene units per 100% by mass of propylene units and butene units: 36% by mass, epoxy group concentration: 0.638 mmol / g, number average molecular weight: 57,000) , Starlight PMC "T-YP312" (maleic anhydride-modified propylene-butene random copolymer, butene unit amount per 100% by mass of propylene unit and butene unit: 29% by mass, acid anhydride group concentration : 0.464 mmol / g, number average molecular weight: 60,900), "T-YP313" manufactured by Seikou PMC (glycidyl methacrylate-modified propylene-butene random copolymer, butene per 100% by mass of propylene unit and butene unit in total) Unit amount: 29% by mass, epoxy group concentration: 0.638 mmol / g, number average molecular weight: 155,000).

<(B) Adhesive-imparting resin>
(B) Adhesive-imparting resin (hereinafter, also abbreviated as “component (b)”) is also called a tack fire, and is a resin that is blended with a plastic polymer to impart adhesiveness. The component (b) is not particularly limited, and is not particularly limited, and is a terpene resin, a modified terpene resin (hydrogenated terpene resin, terpenephenol copolymer resin, aromatic-modified terpene resin, etc.), kumaron resin, inden resin, petroleum resin ( Aliphatic petroleum resins, hydrogenated alicyclic petroleum resins, aromatic petroleum resins, aliphatic aromatic copolymerized petroleum resins, alicyclic petroleum resins, dicyclopentadiene petroleum resins and their hydrides, etc.) Preferred to be used.

Examples of commercially available products that can be used as the component (b) include the following. Examples of the terpene resin include YS resin PX and YS resin PXN (both manufactured by Yasuhara Chemical Co., Ltd.), and examples of the aromatic-modified terpene resin include YS resin TO and TR series (both manufactured by Yasuhara Chemical Co., Ltd.). Examples of the terpene resin include Clearon P, Clearon M, and Clearon K series (all manufactured by Yasuhara Chemical Co., Ltd.), and examples of the terpenphenol copolymer resin include YS Polystar 2000, Polystar U, Polystar T, Polystar S, and Mighty Ace G (all of which are manufactured by Yasuhara Chemical Co., Ltd.). Yasuhara Chemical Co., Ltd.), etc., as hydrogenated alicyclic petroleum resin, Escorez 5300 series, 5600 series (both manufactured by Exxon Mobile Co., Ltd.), etc., and ENDEX 155 (manufactured by Eastman Co., Ltd.) as an aromatic petroleum resin. As the aliphatic aromatic copolymerized petroleum resin, Quintone D100 (manufactured by Nippon Zeon Co., Ltd.) and the like, and as the alicyclic petroleum resin, Quintone 1325, Quintone 1345 (both manufactured by Nippon Zeon Co., Ltd.) and the like can be mentioned. Examples of the cyclohexane ring-containing hydride petroleum resin include Archon P100, Archon P125, and Archon P140 (all manufactured by Arakawa Chemical Co., Ltd.), and examples of the cyclohexane ring-containing saturated hydrocarbon resin include TFS13-030 (manufactured by Arakawa Chemical Co., Ltd.). ..

The softening point of the component (b) is preferably 50 to 200 ° C, more preferably 90 to 180 ° C, and 100 to 100, from the viewpoint that the sheet is softened in the laminating step of the resin composition sheet and has desired heat resistance. 150 ° C. is more preferable. The softening point is measured by the ring ball method according to JIS K2207.

(B) The component may be used alone or in combination of two or more. The content of the component (b) in the resin composition is not particularly limited. However, from the viewpoint of maintaining good moisture permeability of the resin composition, when the component (b) is used, the content thereof is 80% by mass or less per 100% by mass of the total non-volatile content in the resin composition. Is preferable, 60% by mass or less is more preferable, 50% by mass or less is further preferable, and 40% by mass or less is particularly preferable. On the other hand, from the viewpoint of having sufficient adhesiveness, when the component (b) is used, the content thereof is preferably 5% by mass or more per 100% by mass of the total non-volatile content in the resin composition, preferably 10% by mass. The above is more preferable, and 15% by mass or more is further preferable.

Among them, petroleum resin is preferable from the viewpoint of adhesiveness, moisture permeability resistance, transparency and the like of the resin composition. Examples of the petroleum resin include aliphatic petroleum resins, aromatic petroleum resins, aliphatic aromatic copolymerized petroleum resins, and alicyclic petroleum resins. Of these, aromatic petroleum resins, aliphatic aromatic copolymerized petroleum resins, and alicyclic petroleum resins are more preferable from the viewpoints of adhesiveness, moisture permeability resistance, compatibility, and the like of the resin composition. Further, from the viewpoint of improving transparency, an alicyclic petroleum resin is particularly preferable. As the alicyclic petroleum resin, one obtained by hydrogenating an aromatic petroleum resin can also be used. In this case, the hydrogenation rate of the alicyclic petroleum resin is preferably 30 to 99%, more preferably 40 to 97%, still more preferably 50 to 90%. If the hydrogenation rate is too low, there is a tendency for the transparency to decrease due to coloring, and if the hydrogenation rate is too high, the production cost tends to increase. The hydrogenation rate can be determined from the ratio of the peak intensities of ¹ H-NMR of hydrogen in the aromatic ring before hydrogenation and after hydrogenation. As the alicyclic petroleum resin, a cyclohexane ring-containing hydrogenated petroleum resin and a dicyclopentadiene-based hydrogenated petroleum resin are particularly preferable. Petroleum resin may be used alone or in combination of two or more. The number average molecular weight Mn of the petroleum resin is preferably 100 to 2,000, more preferably 700 to 1,500, and even more preferably 500 to 1,000.

<(C) Hygroscopic filler>
The (c) hygroscopic filler (hereinafter, also abbreviated as “component (c)”) is not particularly limited as long as it is a filler having an ability to absorb water, but is preferably a hygroscopic metal oxide. A hygroscopic metal oxide means a metal oxide having an ability to absorb water and chemically reacting with the absorbed water to become a hydroxide. Specific examples thereof include calcium oxide, magnesium oxide, strontium oxide, aluminum oxide, barium oxide, unfired hydrotalcite, semi-fired hydrotalcite, fired hydrotalcite, and fired dolomite. Of these, semi-calcined hydrotalcite and calcined hydrotalcite are preferable from the viewpoint of hygroscopicity.

Hydrotalcite can be classified into uncalcined hydrotalcite, semi-calcined hydrotalcite, and calcined hydrotalcite.

The unfired hydrotalcite is, for example, a metal hydroxide having a layered crystal structure as represented by natural hydrotalcite (Mg ₆ Al ₂ (OH) ₁₆ CO _{3.4H 2} O), for example. It consists of a basic skeleton layer [Mg _1-X Al _X (OH) ₂ ] ^{X +} and an intermediate layer [(CO ₃ ) _{X / 2} · mH ₂ O] ^X- . The uncalcined hydrotalcite in the present invention is a concept including hydrotalcite-like compounds such as synthetic hydrotalcite. Examples of the hydrotalcite-like compound include those represented by the following formulas (I) and the following formula (II).

[M ²⁺ _1-x M ³⁺ x (OH) ₂ ] ^{x +} · [( ^Ann- ) _{x / n} · mH ₂ O] ^x-
(I)
(In the formula, M ²⁺ represents divalent metal ions such as Mg ₂₊ and Zn ²⁺ , M ³⁺ represents ^trivalent metal ions such as Al ³⁺ and Fe ³⁺ , and An − represents CO ₃ ^2- and Cl. -Represents an n ^- valent anion such as-, NO _3- ^, 0 <x <1, 0 ≦ m <1, and n is a positive number.)
In the formula (I), M ²⁺ is preferably Mg ²⁺ , M ³⁺ is preferably Al ³⁺ , and ^An − is preferably CO ₃ ^2- .

M ²⁺ _x Al ₂ (OH) _{2x + 6-nz} ( ^An- ) _z · mH ₂ O (II)
(In the formula, M ²⁺ represents divalent metal ions such as Mg ²⁺ and Zn ²⁺ , An − represents ⁿ -valent anions such as CO ₃ ^2- , Cl ⁻ , NO ^3- , and x is 2 or more. Is a positive number, z is a positive number less than or equal to 2, m is a positive number, and n is a positive number.)
In the formula (II), M ²⁺ is preferably ^{Mg 2+} , and An − is preferably CO ₃ ^2- .

Semi-calcined hydrotalcite refers to a metal hydroxide having a layered crystal structure in which the amount of interlayer water is reduced or eliminated, which is obtained by calcining uncalcined hydrotalcite. The term "interlayer water" refers to "H ₂ O" described in the above-mentioned composition formulas of uncalcined natural hydrotalcite and hydrotalcite-like compounds, if it is described using a composition formula.

On the other hand, the calcined hydrotalcite refers to a metal oxide having an amorphous structure obtained by calcining an uncalcined hydrotalcite or a semi-calcined hydrotalsite, in which not only the interlayer water but also the hydroxyl group disappears by condensation dehydration.

Unfired hydrotalcite, semi-fired hydrotalcite and calcined hydrotalcite can be distinguished by the saturated water absorption rate. The saturated water absorption rate of the semi-baked hydrotalcite is 1% by weight or more and less than 20% by weight. On the other hand, the saturated water absorption rate of unfired hydrotalcite is less than 1% by weight, and the saturated water absorption rate of calcined hydrotalcite is 20% by weight or more.

The "saturated water absorption rate" in the present invention means that 1.5 g of unfired hydrotalcite, semi-baked hydrotalcite or fired hydrotalcite is weighed with a balance, the initial mass is measured, and then the temperature is 60 ° C. under atmospheric pressure. , The mass increase rate with respect to the initial mass when left to stand for 200 hours in a small environmental tester (SH-222 manufactured by Espec Co., Ltd.) set to 90% RH (relative humidity).
Saturated water absorption rate (mass%) = 100 × (mass after moisture absorption-initial mass) / initial mass (i)
Can be obtained at.

The saturated water absorption of the semi-baked hydrotalcite is preferably 3% by weight or more and less than 20% by mass, and more preferably 5% by weight or more and less than 20% by mass.

Further, uncalcined hydrotalcite, semi-calcined hydrotalcite and calcined hydrotalcite can be distinguished by the thermogravimetric reduction rate measured by thermogravimetric analysis. The thermogravimetric reduction rate of the semi-baked hydrotalcite at 280 ° C. is less than 15% by mass, and the thermogravimetric reduction rate at 380 ° C. is 12% by mass or more. On the other hand, the thermogravimetric reduction rate of uncalcined hydrotalcite at 280 ° C. is 15% by mass or more, and the thermogravimetric reduction rate of calcined hydrotalcite at 380 ° C. is less than 12% by mass.

For thermogravimetric analysis, 5 mg of hydrotalcite was weighed on an aluminum sample pan using TG / DTA EXSTAR6300 manufactured by Hitachi High-Tech Science Co., Ltd., and the nitrogen flow rate was 200 mL / min in an open state without a lid. It can be carried out from 30 ° C. to 550 ° C. under the condition of a heating rate of 10 ° C./min. The thermogravimetric reduction rate is calculated by the following formula (ii):
Thermogravimetric reduction rate (mass%)
= 100 × (mass before heating-mass when a predetermined temperature is reached) / mass before heating (ii).

Further, uncalcined hydrotalcite, semi-calcined hydrotalcite and calcined hydrotalcite can be distinguished by the peak and relative intensity ratio measured by powder X-ray diffraction. Semi-baked hydrotalcite shows a peak in which 2θ is split into two in the vicinity of 8 to 18 ° by powder X-ray diffraction, or a peak with a shoulder due to the synthesis of the two peaks, and the peak or shoulder that appears on the low angle side. The relative intensity ratio (low-angle side diffraction intensity / high-angle side diffraction intensity) of the diffraction intensity (= low-angle side diffraction intensity) and the diffraction intensity of the peak or shoulder appearing on the high-angle side (= high-angle side diffraction intensity) is 0.001. ~ 1,000. On the other hand, uncalcined hydrotalcite has only one peak near 8 to 18 °, or the relative intensity ratio of the diffraction intensity of the peak or shoulder appearing on the low angle side and the peak or shoulder appearing on the high angle side is in the above range. Be outside. The calcined hydrotalcite does not have a characteristic peak in the region of 8 ° to 18 °, but has a characteristic peak in 43 °. Powder X-ray diffraction measurement is performed by a powder X-ray diffractometer (PANalytical, Empyrean) with anti-cathode CuKα (1.5405 Å), voltage: 45 V, current: 40 mA, sampling width: 0.0260 °, scanning speed: 0. The measurement was performed under the conditions of .0657 ° / s and the measured diffraction angle range (2θ): 5.0131 to 79.9711 °. The peak search uses the peak search function of the software attached to the diffractive device, "minimum significance: 0.50, minimum peak tip: 0.01 °, maximum peak tip: 1.00 °, peak base width: 2". It can be performed under the condition of ".00 °, method: minimum value of second derivative".

The BET specific surface area of the semi-baked hydrotalcite is preferably 1 to 250 m ² / g, more preferably 5 to 200 m ² / g. The BET specific surface area of the semi-baked hydrotalcite shall be calculated by adsorbing nitrogen gas on the sample surface using a specific surface area measuring device (Macsorb HM Model 1210 Mountech) according to the BET method and using the BET multipoint method. Can be done.

The average particle size of the semi-baked hydrotalcite is preferably 1 to 1,000 nm, more preferably 10 to 800 nm. The average particle size of the semi-baked hydrotalcite is the median diameter of the particle size distribution when the particle size distribution is prepared on a volume basis by laser diffraction scattering type particle size distribution measurement (JIS Z 8825).

As the component (c), one that has been surface-treated with a surface treatment agent can be used. As the surface treatment agent used for the surface treatment, for example, higher fatty acids, alkylsilanes, silane coupling agents and the like can be used, and among them, higher fatty acids and alkylsilanes are preferable. As the surface treatment agent, one kind or two or more kinds can be used.

Examples of the higher fatty acid include higher fatty acids having 18 or more carbon atoms such as stearic acid, montanic acid, myristic acid, and palmitic acid, and among them, stearic acid is preferable. These may be used alone or in combination of two or more. Examples of the alkylsilanes include methyltrimethoxysilane, ethyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, octadecyltrimethoxysilane, dimethyldimethoxysilane, octyltriethoxysilane, and n-octadecyldimethyl (n-octadecyldimethyl). Examples thereof include 3- (trimethoxysilyl) propyl) ammonium chloride. These may be used alone or in combination of two or more. Examples of the silane coupling agent include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropyl (dimethoxy) methylsilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxy. Epoxy-based silane coupling agents such as silane; mercapto-based silane coupling agents such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane and 11-mercaptoundecyltrimethoxysilane. 3-Aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldimethoxymethylsilane, N-phenyl-3-aminopropyltrimethoxysilane, N-methylaminopropyltrimethoxysilane, N- (2) Amino-based silane coupling agents such as -aminoethyl) -3-aminopropyltrimethoxysilane and N- (2-aminoethyl) -3-aminopropyldimethoxymethylsilane; ureido-based silanes such as 3-ureidopropyltriethoxysilane Coupling agents, vinyl-based silane coupling agents such as vinyltrimethoxysilane, vinyltriethoxysilane and vinylmethyldiethoxysilane; styryl-based silane coupling agents such as p-styryltrimethoxysilane; 3-acrylicoxypropyltrimethoxy. An acrylate-based silane coupling agent such as silane and 3-methacryloxypropyltrimethoxysilane; an isocyanate-based silane coupling agent such as 3-isoxypropyltrimethoxysilane, bis (triethoxysilylpropyl) disulfide, and bis (triethoxysilylpropyl). ) A sulfide-based silane coupling agent such as tetrasulfide; phenyltrimethoxysilane, methacryloxypropyltrimethoxysilane, imidazole silane, triazinesilane and the like can be mentioned. These may be used alone or in combination of two or more.

The surface treatment of the component (c) can be performed, for example, by stirring and dispersing the untreated component (c) at room temperature with a mixer, adding and spraying a surface treatment agent, and stirring for 5 to 60 minutes. .. As the mixer, a known mixer can be used, and examples thereof include blenders such as V blenders, ribbon blenders and bubble cone blenders, mixers such as Henshell mixers and concrete mixers, ball mills and cutter mills. Further, when pulverizing the hygroscopic material with a ball mill or the like, a method of mixing the above-mentioned higher fatty acid, alkylsilanes or silane coupling agent and surface-treating the material is also possible. The treatment amount of the surface treatment agent varies depending on the type of the component (c), the type of the surface treatment agent, and the like, but is preferably 1 to 10 parts by mass with respect to 100 parts by mass of the component (c).

The content of the component (c) in the resin composition is not particularly limited. However, from the viewpoint of maintaining the adhesion between the resin composition layer and the substrate such as glass and the transparency of the resin composition layer, the content thereof is 60% by mass per 100% by mass of the total non-volatile content in the resin composition. % Or less is preferable, 55% by mass or less is preferable, 50% by mass or less is more preferable, and 45% by mass or less is further preferable. Further, from the viewpoint of sufficiently obtaining a hygroscopic effect, the content is preferably 10% by mass or more, more preferably 20% by mass or more, and more preferably 30% by mass, based on 100% by mass of the total non-volatile content in the resin composition. The above is more preferable.

Specific examples of the component (c) in the present invention include the following:
-DHT-4C (manufactured by Kyowa Chemical Industry Co., Ltd.): Semi-fired hydrotalcite (average particle size: 400 nm, BET specific surface area: 15 m ² / g)
-DHT-4A-2 (manufactured by Kyowa Chemical Industry Co., Ltd.): Semi-fired hydrotalcite (average particle size: 400 nm, BET specific surface area: 13 m ² / g)
-KW-2200 (manufactured by Kyowa Chemical Industry Co., Ltd.): Calcined hydrotalcite (average particle size: 400 nm, BET specific surface area: 146 m ² / g)
-DHT-4A (manufactured by Kyowa Chemical Industry Co., Ltd.): Unfired hydrotalcite (average particle size: 400 nm, BET specific surface area: 10 m ² / g)

<(D) Curing agent>
From the viewpoint of improving the curing performance of the resin composition, the resin composition may further contain (d) a curing agent (hereinafter, may be abbreviated as "(d) component"). The component (d) is not particularly limited, and examples thereof include an amine-based curing agent, a guanidine-based curing agent, an imidazole-based curing agent, a phosphonium-based curing agent, and a phenol-based curing agent. (D) The components may be used alone or in combination of two or more.

The amine-based curing agent is not particularly limited, but is a quaternary ammonium salt such as tetramethylammonium bromide and tetrabutylammonium bromide; DBU (1,8-diazabicyclo [5.4.0] undecene-7), DBN ( 1,5-Diazabicyclo [4.3.0] nonen-5), DBU-phenol salt, DBU-octylate, DBU-p-toluenesulfonate, DBU-gerate, DBU-phenolnovolak resin salt, etc. Diazabicyclo compound; tertiary amines such as benzyldimethylamine, 2- (dimethylaminomethyl) phenol, 2,4,6-tris (diaminomethyl) phenol and their salts, aromatic dimethylurea, aliphatic dimethylurea, aromatic Dizabiurea compounds such as dimethylurea; and the like. These may be used alone or in combination of two or more.

The guanidine-based curing agent is not particularly limited, but is not particularly limited, but is divided into dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1- (o-tolyl) guanidine, dimethylguanidine, diphenylguanidine, Trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo [4.4.0] deca-5-ene, 7-methyl-1,5,7-triazabicyclo [4.4] .0] Deca-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexyl Examples thereof include biguanide, 1-allyl biguanide, 1-phenylbiguanide, 1- (o-tolyl) biguanide and the like. These may be used alone or in combination of two or more.

The imidazole-based curing agent is not particularly limited, but 1H-imidazole, 2-methyl-imidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methyl-imidazole, 2-phenyl-4. , 5-Bis (hydroxymethyl) -imidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-imidazole, 2-dodecyl-imidazole, Examples thereof include 2-heptadecylimidazole and 1,2-dimethyl-imidazole. These may be used alone or in combination of two or more.

The phosphonium-based curing agent is not particularly limited, but is triphenylphosphine, a phosphonium borate compound, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl) tri. Examples thereof include phenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate and butyltriphenylphosphonium thiocyanate. These may be used alone or in combination of two or more.

The type of phenolic curing agent is not particularly limited, but is MEH-7700, MEH-7810, MEH-7851 (manufactured by Meiwa Kasei Co., Ltd.), NHN, CBN, GPH (manufactured by Nippon Kayaku Co., Ltd.), SN170, SN180, SN190. , SN475, SN485, SN495, SN375, SN395 (manufactured by Toto Kasei Co., Ltd.), TD2090 (manufactured by DIC Corporation) and the like. Specific examples of the triazine skeleton-containing phenolic curing agent include LA3018 (manufactured by DIC Corporation) and the like. Specific examples of the triazine skeleton-containing phenol novolac curing agent include LA7052, LA7054, LA1356 (manufactured by DIC Corporation) and the like. These may be used alone or in combination of two or more.

The content of the component (d) in the resin composition is not particularly limited. However, from the viewpoint of preventing deterioration of moisture permeability, when the component (d) is used, the content thereof is preferably 5% by mass or less per 100% by mass of the total non-volatile content in the resin composition. More preferably, it is by mass or less. On the other hand, from the viewpoint of suppressing tack, when the component (d) is used, the content thereof is preferably 0.01% by mass or more per 100% by mass of the total non-volatile content in the resin composition, preferably 0.05. More preferably by mass% or more.

<(E) Resin having a functional group that can react with an epoxy group>
In the resin composition of the present invention, when a polyolefin resin having an epoxy group as the component (a) is used, a functional group capable of reacting with the epoxy group (e) as a component for forming a crosslinked structure with the component (a). It is desirable to use a resin having the above (hereinafter, may be abbreviated as "component (e)"). Examples of the functional group capable of reacting with the epoxy group include a hydroxyl group, a phenolic hydroxyl group, an amino group, a carboxy group, an acid anhydride group and the like, and an acid anhydride group is preferable. Examples of the acid anhydride group include a group derived from succinic anhydride, a group derived from maleic anhydride, a group derived from glutaric anhydride and the like. Examples of the resin include polyolefin resins (excluding polyolefin resins having an acid anhydride group as a component (a)), acrylic resins, melamine resins, phenol resins, urea resins, polyester resins, alkyd resins, polyurethanes, and polyimides. Examples thereof include resins, and polyolefin resins are preferable. The polyolefin-based resin as the component (e) is the same as the above-mentioned component (a) except that it has a hydroxyl group, a phenolic hydroxyl group, an amino group, a carboxy group and the like as a functional group instead of an acid anhydride group. Polyolefin-based resins can be mentioned, with polybutene being preferred.

The content of the component (e) in the resin composition is not particularly limited. However, from the viewpoint of preventing deterioration of moisture permeability, when the component (e) is used, the content thereof is preferably 30% by mass or less per 100% by mass of the total non-volatile content in the resin composition. More preferably, it is by mass or less. On the other hand, from the viewpoint of suppressing tack, when the component (e) is used, the content thereof is preferably 5% by mass or more, preferably 10% by mass or more, based on 100% by mass of the total non-volatile content in the resin composition. More preferred.

<(F) Resin having a functional group capable of reacting with an acid anhydride group>
When a polyolefin resin having an acid anhydride group is used as the component (a) in the resin composition, the functionality capable of reacting with the (f) acid anhydride group as a component for forming a crosslinked structure with the component (a). It is desirable to use a resin having a group (hereinafter, may be abbreviated as "component (f)"). Examples of the functional group capable of reacting with the acid anhydride group include a hydroxyl group, a primary or secondary amino group, a thiol group, an epoxy group, an oxetane group and the like, and an epoxy group is preferable. Examples of the resin include polyolefin resins (excluding polyolefin resins having an epoxy group as a component (a)), acrylic resins, melamine resins, phenol resins, urea resins, polyester resins, alkyd resins, polyurethanes, and polyimide resins. However, a polyolefin resin is preferable. The polyolefin resin as the component (f) is described above except that the functional group has a hydroxyl group, a primary or secondary amino group, a thiol group, an epoxy group, an oxetane group, or the like, instead of an epoxy group. a) Examples thereof include a polyolefin resin similar to the component, and polybutene is preferable.

The content of the component (f) in the resin composition is not particularly limited. However, from the viewpoint of preventing deterioration of moisture permeability, when the component (f) is used, the content thereof is preferably 30% by mass or less per 100% by mass of the total non-volatile content in the resin composition. More preferably, it is by mass or less. On the other hand, from the viewpoint of suppressing tack, when the component (f) is used, the content thereof is preferably 5% by mass or more, preferably 10% by mass or more, based on 100% by mass of the total non-volatile content in the resin composition. More preferred.

<(G) Plasticizer>
The resin composition may further contain (g) a plasticizer (hereinafter, may be abbreviated as "(g) component"). By using the component (g), the flexibility and moldability of the resin composition can be improved. The component (g) is not particularly limited, but a material liquid at room temperature is preferably used. Specific examples of the plasticizer include paraffin-based process oil, naphthenic process oil, liquid paraffin, polyethylene wax, polypropylene wax, mineral oil such as vaseline, castor oil, cottonseed oil, rapeseed oil, soybean oil, palm oil, palm oil, and olive oil. Examples thereof include vegetable oils such as, liquid polybutene, hydrogenated liquid polybutene, liquid polybutadiene, and liquid poly α-olefins such as hydrogenated liquid polybutadiene. As the plasticizer used in the present invention, liquid poly-α-olefins are preferable, and liquid polybutadiene is particularly preferable. The liquid poly-α-olefin preferably has a low molecular weight from the viewpoint of adhesiveness, and preferably has a weight average molecular weight in the range of 500 to 5,000, more preferably 1,000 to 3,000. These plasticizers may be used alone or in combination of two or more. Here, "liquid" is a state of the plasticizer at room temperature (25 ° C.). When the component (g) is used, the content thereof is preferably 50% by mass or less per 100% by mass of the total non-volatile content in the resin composition from the viewpoint of not adversely affecting the organic EL element.

<Other additives>
The resin composition may optionally contain various additives other than the above-mentioned components to the extent that the effects of the present invention are not impaired. Examples of such additives include resins other than the above-mentioned components (a), (e) and (f) (for example, epoxy resin, urethane resin, acrylic resin, polyamide resin, etc.), silica, and barium sulfate. , Tarku, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, boron nitride, aluminum borate, barium titanate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, zircon Inorganic fillers such as barium acid and calcium zirconate (excluding hygroscopic fillers); organic fillers such as rubber particles, silicone powder, nylon powder and fluororesin powder; thickeners such as olben and benton; silicon-based , Fluorine-based, polymer-based defoaming agent or leveling agent; adhesion-imparting agent such as triazole compound, thiazole compound, triazine compound, porphyrin compound; and the like.

<Preparation of resin composition>
The method for preparing the resin composition is not particularly limited, and examples thereof include a method in which a compounding component is added with a solvent or the like, if necessary, and mixed using a kneading roller, a rotary mixer, or the like.

The thickness of the (A) pressure-sensitive adhesive resin composition layer 1 in the sealing sheet of the present invention is not particularly limited, but is preferably 1 μm or more, preferably 3 μm or more, from the viewpoint of stable sealing performance, handleability, and the like. Is more preferable. Further, from the viewpoint of thinning the sealing structure, embedding property and the like, 100 μm or less is preferable, and 50 μm or less is more preferable.

The moisture resistance (water vapor barrier property) of (A) the pressure-sensitive adhesive resin composition layer 1 alone varies depending on, for example, the constituent material and the thickness of the pressure-sensitive adhesive resin composition layer 1, but the thickness may vary. Moisture vapor transmission rate per 1 m ² under the above-mentioned preferable range (3 to 50 μm), temperature 40 ° C., humidity 90% RH, and 24-hour measurement conditions measured by a method according to JIS Z 0208: 1976. The degree is generally 0.1 to 100 g / ( ^m 2.24 h), preferably 0.1 to 50 g / ( ^m 2.24 h).

[(B) Moisture-proof inorganic film]
The sealing sheet of the present invention has a structure in which (B) a moisture-proof inorganic coating 2 is directly formed on one side of the (A) pressure-sensitive adhesive resin composition layer.
(B) Moisture-proof inorganic film (hereinafter, also simply referred to as "inorganic film") 2 is a film having moisture-proof properties formed by an inorganic substance, and "inorganic substance" is an organic substance (carbon dioxide when burned). It refers to substances other than those that are generated or burned to black and become charcoal.

(B) Moisture-proof Inorganic film 2 can impart excellent moisture-proof properties to the sealing sheet even if it is thin. Therefore, (B1) a silica glass film made of a heat-treated product of a polysilazane-containing coating film (hereinafter, "" (B1) Silica glass film ”) or (B2) Inorganic material vapor deposition film is preferably used.

<(B1) Silica glass film made of heat-treated product of polysilazane-containing coating film>
The (B1) silica glass film is obtained by heating the polysilazane-containing coating film formed on one side of the (A) pressure-sensitive adhesive resin composition layer 1 in a water vapor-containing atmosphere.

As polysilazane, for example, equation (1)

(In the formula, n represents an arbitrary natural number. Rx and Ry are independently hydrogen atoms, an alkyl group having an unsubstituted or substituent, a cycloalkyl group having an unsubstituted or substituent, and an unsubstituted or substituted group. Represents a non-hydrolytable group such as an alkenyl group having a group, an aryl group having no substituent or a substituent. Rz is a hydrogen atom, an alkyl group having no substituent or a substituent, and a cycloalkyl having no substituent or a substituent. Represents a non-hydrolytable group such as a group, an alkenyl group having an unsubstituted or substituent, an aryl group having an unsubstituted or substituent, or an alkylsilyl group.)
A compound having a repeating unit represented by (hereinafter, also referred to as “polysilazane compound of formula (1)”) is used.

Examples of the alkyl group of the alkyl group having no substituent or substituent include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group and a t-butyl group. Examples thereof include an alkyl group having 1 to 10 carbon atoms such as an n-pentyl group, an isopentyl group, a neopentyl group, an n-hexyl group, an n-heptyl group and an n-octyl group.

Examples of the cycloalkyl group of the cycloalkyl group having no substituent or substituent include a cycloalkyl group having 3 to 10 carbon atoms such as a cyclobutyl group, a cyclopentyl group, a cyclohexyl group and a cycloheptyl group.

Examples of the alkenyl group of the alkenyl group having no substituent or substituent include a vinyl group, a 1-propenyl group, a 2-propenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group and the like having 2 carbon atoms. Included are ~ 10 alkenyl groups.

Examples of the substituents of the alkyl group, cycloalkyl group and alkenyl group include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom; hydroxyl group; thiol group; epoxy group; glycidoxy group; (meth) acryloyloxy group. An aryl group having an unsubstituted or substituent such as a phenyl group, a 4-methylphenyl group, a 4-chlorophenyl group; and the like can be mentioned.

Examples of the aryl group of the aryl group having no substituent or substituent include an aryl group having 6 to 10 carbon atoms such as a phenyl group, a 1-naphthyl group and a 2-naphthyl group.

The substituent of the aryl group includes a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom; an alkyl group having 1 to 6 carbon atoms such as a methyl group and an ethyl group; and a carbon number such as a methoxy group and an ethoxy group. 1 to 6 alkoxy groups; nitro group; cyano group; hydroxyl group; thiol group; epoxy group; glycidoxy group; (meth) acryloyloxy group; phenyl group, 4-methylphenyl group, 4-chlorophenyl group, etc. An aryl group having a substituent; and the like can be mentioned.

Examples of the alkylsilyl group include a trimethylsilyl group, a triethylsilyl group, a triisopropylsilyl group, a trit-butylsilyl group, a methyldiethylsilyl group, a dimethylsilyl group, a diethylsilyl group, a methylsilyl group, an ethylsilyl group and the like.

Among these, as Rx, Ry, and Rz, a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group is preferable.

The polysilazane of the formula (1) can be produced by a conventionally known method. For example, it can be obtained by reacting a reaction product of a halogenosilane compound having an unsubstituted or substituent represented by the following formula (2) with a secondary amine with ammonia or a primary amine.

^R1 _4-m SiX _m (2)
(In the formula, m represents 2 or 3, X represents a halogen atom, and R ¹ represents any of Rx, Ry, and Rz substituents in the formula (1).)

The secondary amine, ammonia and the primary amine may be appropriately selected depending on the structure of the target polysilazane compound.

The polysilazane may be a perhydroxypolysilazane in which Rx, Ry, or Rz are all hydrogen atoms in the formula (1), or an organopolysilazane in which at least one of Rx, Ry, and Rz is not a hydrogen atom. However, perhydroxypolysilazane is preferable from the viewpoint of stability of conversion to polysiloxane (hydrolysis reaction).

The molecular weight of polysilazane is not particularly limited, but the number average molecular weight is usually about 100 to 50,000. The number average molecular weight can be measured by VPO (vapor pressure drop method) using a toluene solution of the polymer or the like.

One kind or two or more kinds of polysilazane compounds can be used.

The polysilazane-containing coating film is formed by, for example, applying a coating liquid containing polysilazane and a solvent onto the (A) pressure-sensitive adhesive resin composition layer 1 and drying. The drying may be natural drying or warm drying. When the applied coating liquid is heated and dried, the coating liquid is dried by heating and drying in a water vapor-containing atmosphere, and after drying, the silica glass film is formed by heating (heat treatment) in the water vapor-containing atmosphere of the coating film. It can be done continuously.

The solvent is not particularly limited as long as it is an organic solvent that dissolves polysilazane and is inert to polysilazane, but from the viewpoint of volatileness and environmental hygiene, for example, dimethyl ether, diethyl ether, dipropyl ether, dibutyl ether and the like can be used. Ether-based organic solvents are preferred. One type or two or more types of AEL-based organic solvent can be used. Further, an aromatic hydrocarbon solvent such as anisole may be mixed in the range of 10% by mass or less with respect to the ether-based organic solvent. The polysilazane concentration in the coating liquid is preferably about 1 to 30% by mass. Further, the coating liquid may contain various additives such as a hydrolysis catalyst.

Such polysilazane-containing coating liquids are commercially available under the names such as "glass coating agent" and "silica coating agent", and commercially available products can be used as they are. Examples of commercially available products include "Olam Z" and "Olam OZ" manufactured by Artbreed Co., Ltd., "NAX110", "NAX120", "NL110A" and "NN110" manufactured by Merck Co., Ltd.

(A) The method of applying the coating liquid on the pressure-sensitive adhesive resin composition layer 1 is a method in which a coating liquid such as spin coat, spray coat, dip coat, bar coat or the like can be applied to a liquid film having a substantially uniform thickness. If so, it is not particularly limited. The coating amount of the coating liquid is also not particularly limited, but the coating amount is generally 0.01 to 100 g / m ² in terms of solid content, preferably 0.05 to 10 g / m ² . When the coating amount is within the range, it is possible to form a coating film having a thin thickness and forming a silica glass film exhibiting sufficiently high moisture resistance (water vapor barrier property).

In order to form a silica glass film, the polysilazane-containing coating film is heated (heat-treated) in a water vapor-containing atmosphere, and the water vapor-containing atmosphere includes air, humidified air, and a humidified inert gas (for example, nitrogen, argon, helium, etc.). ) Etc. can be mentioned.

The heating (heat treatment) temperature of the coating film is preferably 200 ° C. or lower, more preferably 50 to 150 ° C. from the viewpoint of preventing the modification or deterioration of the (A) pressure-sensitive adhesive resin composition layer. The heating time is generally 30 minutes to 5 hours. For example, air having a humidity of 20 to 100% RH or humidified air is a preferable water vapor-containing atmosphere.

The composition of the silica glass film can be changed stepwise by changing the heating temperature, the water vapor concentration in the water vapor-containing atmosphere, and the like.

(A) The heating means used for drying the coating liquid applied to the pressure-sensitive adhesive resin composition layer and heating (heat treatment) the coating film for forming a silica glass film is not particularly limited, and is not particularly limited, for example. A heat circulation oven, hot plate, etc. are used.

Various ceramic coating agents containing silica (SiO ₂ ) as a main component are known, but as shown in a comparative example described later, (A) a ceramic coating is applied to one side of the pressure-sensitive adhesive resin composition layer. Even if a thermosetting film of the coating film of the agent is formed, it is not possible to impart moisture resistance to the (A) pressure-sensitive adhesive resin composition layer, and (A) a single layer of the pressure-sensitive adhesive resin composition layer. The amount of water vapor permeation of the sheet ((A) pressure-sensitive adhesive resin composition layer / heat-curing film) on which the thermosetting film is formed is rather large compared to the amount of water vapor permeation of the sheet.

<(B2) Inorganic vapor deposition film>
The (B2) inorganic material vapor deposition film is formed by depositing an inorganic substance on one side of the (A) pressure-sensitive adhesive resin composition layer 1. Examples of the inorganic substance include silicon compounds such as SiC, SiO ₂ , Si 3N ₄ , SiCN, SiOC, _SiOCN , polysilazane, and alkoxysilane, aluminum oxide, indium oxide, tin oxide, gallium oxide, and indium tin oxide (ITO). One or more selected types such as aluminum-added zinc oxide (AZO), zinc-tin composite oxide (ZTO), aluminum nitride, and zirconium oxide can be mentioned. Of these, a silicon compound is preferable from the viewpoint of (A) excellent adhesion to the pressure-sensitive adhesive resin composition layer 1 and the ability to form a vapor-deposited film having high moisture resistance. That is, the (B2) inorganic vapor-deposited coating is preferably a silicon compound vapor-deposited coating.

(B2) The inorganic vapor deposition film may be a vapor deposition film formed by either a chemical vapor deposition method or a physical vapor deposition method.

Further, the (B2) inorganic vapor-deposited film may be a single-layer film or a multilayer film. (B2) When the inorganic substance vapor deposition film is a silicon compound vapor deposition film, a preferred embodiment includes a SiO ₂ -SiCN multilayer vapor deposition film including one or more SiO ₂ vapor deposition films and one or more SiCN vapor deposition films. The thickness of each of the single layer SiO ₂ layer and the single layer SiCN layer in the SiO ₂ -SiCN multilayer vapor deposition film is preferably 10 to 100 nm. Further, the total number of layers is preferably 2 or more, and more preferably 6 or more. Further, 20 layers or less are preferable, and 12 layers or less are more preferable. Further, the SiO ₂ -SiCN multi-layer vapor deposition film is preferably one in which the SiO ₂ vapor deposition layers and the SiCN vapor deposition layers are alternately laminated from the viewpoint of excellent water vapor barrier properties. Further, the SiO ₂ vapor deposition layer and the SiCN vapor deposition layer may be either a physical vapor deposition layer or a chemical vapor deposition layer, respectively, but the chemical vapor deposition can form a film at a low temperature, and the property stability of the sealing sheet. From the viewpoint of shape stability and the like, it is preferable that the SiO ₂ chemical vapor deposition layer and the SiCN chemical vapor deposition layer are alternately laminated.

A preferred embodiment in the case of forming a SiO ₂ -SiCN multiplex vapor deposition film in which a SiO ₂ chemical vapor deposition layer and a SiCN chemical vapor deposition layer are alternately laminated is as follows.

After maintaining the pressure in the vapor deposition chamber at about 1 Pa and the temperature at about 100 ° C., SiO ₂ is vapor-deposited using hexamethyldisilazane and oxygen gas as raw materials. After this vapor deposition is performed for about 1 minute, the raw material gas is switched to hexamethyldisilazane and hydrogen gas, and SiCN is further vapor-deposited for about 1 minute. By repeating the above process until the desired layer structure is obtained, a SiO ₂ -SiCN multiplex vapor deposition film in which the SiO ₂ chemical vapor deposition layer and the SiCN chemical vapor deposition layer are alternately laminated is formed.

The thickness of the (B) moisture-proof inorganic film ((B1) silica glass film, (B2) inorganic vapor-deposited film) 2 is preferably 1000 nm or less, more preferably 500 nm or less, from the viewpoint of thinning the sealing structure and the like. 400 nm or less is even more preferable. Further, from the viewpoint of obtaining sufficiently high moisture resistance, 10 nm or more is preferable, 20 nm or more is more preferable, and 30 nm or more is even more preferable.

The moisture-proof property (water vapor barrier property) of the moisture-proof inorganic film 2 is composed of the pressure-sensitive adhesive resin composition layer 1 and the moisture-proof inorganic film 2 when the moisture-proof inorganic film 2 has a thickness of 1000 nm or less. The water vapor transmission rate per 1 m ² under the measurement conditions of a temperature of 40 ° C., a humidity of 90% RH, and 24 hours measured by a method according to JIS Z 0208: 1976 of the two-layer sheet is only for the resin composition layer 1. Moisture-proof (water vapor barrier property) of 70% or less (preferably 65% or less, more preferably 60% or less) of the water vapor transmission rate per 1 m ² measured by the same method and the same conditions of the single-layer sheet. Is preferable.

In the sealing sheet of the present invention, the moisture-proof property (water vapor barrier property) of the two-layer sheet composed of the resin composition layer 1 and the moisture-proof inorganic film 2 obtained by peeling off the support 3 is JIS Z 0208: 1976. The water vapor transmission rate per 1 m ² under the measurement conditions of temperature 40 ° C., humidity 90% RH, and 24 hours, which is measured by a method according to the above, is preferably 40 g / ( ^m 2.24 h) or less, preferably 30 g /. It is more preferably (m ^2.24h ) or less, and even more preferably 20 g / (m ^2.24h ) or less.

[(C) Release-treated support]
The release-treated support 3 is a support on which one side of the resin composition layer 1 is formed with a mold-release treatment, and the sealing sheet is actually used for forming the sealing structure. A support that is previously peeled off. For this reason, the release-treated support 3 does not necessarily have to be moisture-proof, but prevents moisture from entering the resin composition layer 1 during the storage period until the sealing sheet is subjected to sealing. From the viewpoint of moisture resistance, it is preferable to have moisture resistance.

Examples of the support having a moisture-proof property include a plastic film having a moisture-proof property, a metal foil such as a copper foil and an aluminum foil, and the like. Examples of the moisture-proof plastic film include a plastic film in which an inorganic substance such as SiO ₂ , Si 3N ₄ , SiCN, and amorphous silicon is vapor _- deposited on the surface. Here, examples of the plastic film on which an inorganic substance is vapor-deposited on the surface include polyolefin (for example, polyethylene, polypropylene, polyvinyl chloride, etc.) and polyester (for example, polyethylene terephthalate (hereinafter, may be abbreviated as "PET")). , Polyethylene terephthalate, etc.), polycarbonate, polyimide and other plastic films are suitable, and PET films are particularly preferable. Examples of commercially available moisture-proof plastic films have a more moisture-proof effect than the Tech Barrier HX, AX, LX, L series (manufactured by Mitsubishi Plastics) and the Tech Barrier HX, AX, LX, L series. Examples include the enhanced X-BARRIER (manufactured by Mitsubishi Plastics). Further, as the support having moisture resistance, one having a multi-layer structure of two or more layers, for example, one in which the above plastic film and the above metal foil are bonded together via an adhesive can also be used. This is inexpensive and is advantageous from the viewpoint of handleability.

As the release-treated support 3, a support having no moisture resistance (for example, a simple substance of a plastic film on which an inorganic substance is not vapor-deposited on the surface) can also be used. The thickness of the support is not particularly limited, but is preferably 10 to 150 μm, more preferably 20 to 100 μm, from the viewpoint of handleability of the sealing sheet and the like.

Specific examples of the mold release agent for the mold release treatment include a fluorine-based mold release agent, a silicone-based mold release agent, and an alkyd resin-based mold release agent. A mixture of different types of mold release agents may be used.

[(D) Circularly polarizing plate]
The circular polarizing plate is generally composed of a polarizing plate and a 1/4 wave plate. When a circular polarizing plate is used as a support, a 1/4 wave plate is generally arranged on the sealing resin composition layer side. When a support including both a circular polarizing plate and a moisture-proof support is used, the moisture-proof support is preferably arranged on the sealing resin composition layer side, and the 1/4 wave plate of the circular polarizing plate is moisture-proof. It is placed on the support side. The moisture-proof support and the circularly polarizing plate can be adhered with an adhesive or the like. The sealing sheet of the present invention is intended to be a sealing sheet particularly suitable for sealing an organic EL element, and as shown in FIG. 2, (B) the moisture-proof inorganic coating 2 is (A) pressure-sensitive adhesive. By adhering the (D) circularly polarizing plate 4 to the surface opposite to the side of the sex resin composition layer 1, a sealing sheet 11 for an organic EL element capable of forming a sealing structure in which the circularly polarizing plate is integrated can be formed. Can be.

In FIG. 2, the same reference numerals as those in FIG. 1 indicate the same or corresponding portions, and FIG. 4 is a circular polarizing plate. The circular polarizing plate 4 has a retardation film 41 that functions as a 1/4 wavelength plate and a polarizing element (platelet) 42 that is directly adhered to the retardation film 41. A) The pressure-sensitive adhesive resin composition is adhered to the surface opposite to the layer side via the adhesive layer 5. A known circular polarizing plate 4 composed of the retardation film 41 and the polarizing plate (platelet) 42 can be used, and is described in, for example, Japanese Patent Application Laid-Open No. 2016-105166, International Publication No. 2014/003189, and the like. Can be mentioned.

The adhesive used for the adhesive layer 5 is not particularly limited as long as it is a highly transparent adhesive, and for example, an acrylic adhesive, a polyvinyl alcohol-based adhesive, or the like is used.

The circular polarizing plate 4 may be provided with a protective film (not shown) that protects the polarizing element (polarizing plate) 42. A known protective film can also be used, and examples thereof include the protective film described in JP-A-2016-105166 and International Publication No. 2014/003189 pamphlet.

[Manufacturing of sealing sheet]
In the sealing sheet of the present invention, (B) a moisture-proof inorganic film 2 is formed on (A) a pressure-sensitive adhesive resin composition layer 1 formed on a support 3 which has been mold-released. Just do it.

(A) The pressure-sensitive adhesive resin composition layer 1 may be formed by a method known to those skilled in the art. For example, a varnish in which the resin composition is dissolved in an organic solvent is prepared, and the varnish is applied onto the support. It can be formed by drying. The organic solvent can be dried by blowing hot air or the like. When the resin composition of the present invention contains a curable component such as a polyolefin resin having an epoxy group, the resin composition layer may be further heated to form a cured resin composition layer.

Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone (hereinafter abbreviated as "MEK"), cyclohexanone; acetic acid such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate. Esters; Carbitols such as cellosolve and butylcarbitol; Aromatic hydrocarbons such as toluene and xylene; Dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like; can. Examples of the aromatic mixed solvent include "Swazole" (manufactured by Maruzen Petroleum Co., Ltd., trade name) and "Ipsol" (manufactured by Idemitsu Kosan Co., Ltd., trade name). The organic solvent may be used alone or in combination of two or more.

The drying conditions are not particularly limited, but are preferably 50 to 100 ° C. for 1 to 60 minutes. When the temperature is 50 ° C. or higher, the amount of the solvent remaining in the resin composition layer can be easily reduced.

(1) Both a polyolefin resin having an acid anhydride group and a polyolefin resin having an epoxy group are used as the component (a), and (2) a polyolefin resin having an epoxy group is used as the component (a). And (e) component (that is, a resin having a functional group capable of reacting with an epoxy group) is used, or (3) (a) a polyolefin resin having an acid anhydride group is used, and (f). By using a component (ie, a resin having a functional group capable of reacting with an acid anhydride group), the resin composition may be heated before the sealing step to form a crosslinked structure, and after the sealing step. It may be heated to form a crosslinked structure. For example, when sealing an element (for example, an organic EL element) using the sealing sheet of the present invention, the resin composition layer may be preheated to form a crosslinked structure before the sealing step. Then, after the sealing step, the resin composition layer may be heated to form a crosslinked structure. From the viewpoint of reducing thermal deterioration of the element (for example, an organic EL element), it is preferable to preheat the element (for example, an organic EL element) before the sealing step to form a crosslinked structure.

When the (A) pressure-sensitive adhesive resin composition layer 1 is heated before the sealing step, the heating conditions are not particularly limited, but the temperature is preferably 50 to 200 ° C, more preferably 100 to 180 ° C. 120 to 160 ° C. is more preferable. The heating time is preferably 15 to 120 minutes, more preferably 30 to 100 minutes.

When the (A) pressure-sensitive adhesive resin composition layer 1 is thermally cured after the sealing step, the curing temperature is preferably 50 to 150 ° C. from the viewpoint of preventing thermal deterioration of the element (for example, an organic EL element). , 60 to 100 ° C. is more preferable, and 60 to 80 ° C. is even more preferable.

(A) After the pressure-sensitive adhesive resin composition layer 1 is formed, (B) a moisture-proof inorganic film 2 ((B1) silica glass film or (B2) inorganic vapor-deposited film) is formed by the above-mentioned method. When (D) a sealing sheet having a circularly polarizing plate 4 is manufactured, an adhesive layer or an adhesive layer or an adhesive layer or an adhesive layer or a surface of (B1) silica glass coating or (B2) inorganic vapor deposition coating) is formed on the surface of (B) moisture-proof inorganic coating 2 ((B1) silica glass coating or (B2) inorganic vapor deposition coating). The pressure-sensitive adhesive layer 5 may be formed and the circular polarizing plate 4 may be adhered.

<Use of sealing sheet>
The sealing sheet of the present invention is used for sealing electronic components such as semiconductors, solar cells, high-brightness LEDs, LCDs, and EL elements, preferably optical semiconductors such as solar cells and organic EL elements. In particular, it is suitably used for encapsulating an organic EL element. Specifically, the sealing sheet of the present invention may be used in order to apply to the upper part and / or the surrounding (side part) of the light emitting part of the organic EL element to protect the light emitting part of the organic EL element from the outside. can.

<Organic EL device>
The present invention also provides an organic EL device in which an organic EL element is sealed with the above-mentioned sealing sheet of the present invention. For example, the organic EL device of the present invention can be obtained by laminating the sealing sheet of the present invention on a substrate having an organic EL element. In the sealing operation, the release-treated support 3 is peeled off from the sealing sheet, and the sealing sheet is laminated on the substrate so that the pressure-sensitive adhesive resin composition layer 1 is in direct contact with the substrate. do. The laminating method may be a batch method or a continuous method using a roll. If thermosetting is required for sealing, thermosetting is performed.

When the organic EL element is sealed with the sealing sheet of the present invention, the moisture-proof inorganic coating 2 is thin and less rigid than the sealing base material (plastic film having an inorganic vapor deposition coating, metal foil, etc.). Damage to the organic EL element during sealing work can be significantly reduced. Moreover, the sealing sheet has excellent moisture resistance (water vapor barrier property) due to the moisture-proof inorganic film 2, and since the pressure-sensitive adhesive resin composition layer 1 contains a moisture-absorbing filler, it is thin and has a high water absorption rate. It is possible to form a sealing structure that is low and has excellent moisture permeability resistance. Therefore, the organic EL device can be made thinner and have higher performance. Further, by using a sealing sheet in which a circularly polarizing plate is integrated, it is possible to easily obtain an organic EL device having a function of preventing external light reflection, which is made thinner and has higher performance.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the following description, "parts" and "%" in the amounts of the components and the copolymerization unit mean "parts by mass" and "% by mass", respectively, unless otherwise specified.

The raw materials used in the examples and comparative examples are as follows.
1. 1. Material for forming a layer of pressure-sensitive adhesive resin composition (a) Polyolefin resin ・ ACRYFT CM5022 (manufactured by Sumitomo Chemical Co., Ltd.): Ethylene-methylmethacrylate copolymer, methyl per 100% of ethylene unit and methylmethacrylate unit in total Amount of methacrylate unit (33%), number average molecular weight 71,000)
Tough selenium X1102 (manufactured by Sumitomo Chemical Co., Ltd.): Propylene-butene copolymer, amount of butene units per 100% by mass of propylene units and butene units (29%), number average molecular weight 658,000)
HV-300M (manufactured by Toho Chemical Industry Co., Ltd.): Maleic anhydride-modified liquid polybutene (acid anhydride group concentration: 0.77 mmol / g, number average molecular weight 2,100)
-HV-1900 (manufactured by JX Energy Co., Ltd.): Polybutene (number average molecular weight 2,900)

(B) Adhesive-imparting resin-Alcon P125 (manufactured by Arakawa Chemical Co., Ltd.): Cyclohexane ring-containing hydrogenated petroleum resin (softening point 125 ° C)

(C) Hygroscopic filler-DHT-4C (manufactured by Kyowa Chemical Industry Co., Ltd.): Semi-baked hydrotalcite (average particle size: 400 nm, BET specific surface area: 15 m ² / g)

(D) Curing agent-Amine-based curing agent (2,4,6-tris (diaminomethyl) phenol, hereinafter abbreviated as "TAP")

Organic solvent ・ Toluene ・ Swazole # 1000 (manufactured by Maruzen Petrochemical Co., Ltd.): Aromatic mixed solvent

2. 2. Coating agent for forming an inorganic film (1) OlamZ (Artbreed Co., Ltd.)
Polysilazane-based glass coating agent (perhydroxypolysilazane)
(2) SSG HB21N (Nittobo Medical Co., Ltd.)
Alkoxysilane-based glass coating agent (tetraethoxysilane)
(3) G401 (Nikken Co., Ltd.)
Alkoxy metal salt-based ceramic coating agent (main components: SiO _2, ZrO ₃ )
(4) SZ-90 (Nikken Co., Ltd.)
Alkoxy metal salt-based ceramic coating agent (main component: silicone resin, ZrO ₃ ) (5) GA1-92-52 (Niken Co., Ltd.)
Alkoxy metal salt / resin hybrid ceramic coating agent (main components: SiO ₂ , Al ₂ O ₃ , Ag, acrylic resin)
(6) GB1-92 (Nikken Co., Ltd.)
Alkoxy metal salt / resin hybrid ceramic coating agent (main components: SiO ₂ , Al ₂ O ₃ , butyral resin)
(7) G1-90 (Nikken Co., Ltd.)
Alkoxy metal salt-based ceramic coating agent (main component: SiO ₂ , alkylalkoxysilane)

[Examples 1 to 9 and Comparative Examples 1 to 6]
A sealing sheet (sheet 1) in which only the pressure-sensitive adhesive resin composition layer was formed on a PET film (support) obtained by preparing the resin compositions of the formulations shown in Tables 1 and 2 and subjected to mold release treatment, and A pressure-sensitive adhesive resin composition layer is formed on the release-treated PET film (support), and the pressure-sensitive adhesive resin composition layer is further coated with the coating agents for forming an inorganic film shown in Tables 1 and 2. A sealing sheet (sheet 2) having an inorganic film formed on one side was produced.
In the formulations of the resin compositions shown in Tables 1 and 2, the amounts of the components other than the organic solvent are values converted into non-volatile components.

<Example 1>
130 parts of cyclohexane ring-containing hydrogenated petroleum resin (Arcon P125, 60% swazole # 1000 solution), 210 parts of ethylene-methylmethacrylate copolymer (CM5022, 20% toluene solution), 94 parts of polybutene (HV-1900), and 100 parts of semi-baked hydrotalcite (DHT-4C) was dispersed in 3 rolls to obtain a mixture. 0.5 part of an amine-based curing agent (TAP) and 100 parts of toluene were added to the obtained mixture, and the obtained mixture was uniformly dispersed with a high-speed rotary mixer to obtain a varnish of a resin composition. The obtained varnish was uniformly applied on the release-treated surface of a PET film (thickness 38 μm) treated with a silicone-based mold release agent with a die coater, and heated at 130 ° C. for 60 minutes to obtain a thickness. A sealing sheet (sheet 1) having a pressure-sensitive adhesive resin composition layer of 45 μm was obtained.

10 g of a polysilazane-based glass coating agent (“OlamZ”, Artbreed Co., Ltd.) was applied onto the pressure-sensitive adhesive resin composition layer of the sealing sheet obtained in the same manner as described above. Then, a film was formed on a spin coater at 2000 rpm for 1 minute (coating amount: 1 g / m ² (solid content conversion)). By heating the sheet thus obtained at 60 ° C. for 30 minutes and then heating at 130 ° C. for 60 minutes, one side of the pressure-sensitive adhesive resin composition layer is a heat-treated product (silica glass film) of a polysilazane-containing coating film. A coated sealing sheet (sheet 2) was obtained.

<Example 2>
Sheets 1 and 2 were prepared in the same manner as in Example 1 except that ACRYFT CM5022 was changed to a propylene-butene copolymer (X1102).

<Example 3>
Except for changing ACRYFT CM5022 to 40 parts of propylene-butene copolymer (X1102) and 35 parts of maleic anhydride-modified liquid polybutene (HV-300M), and changing polybutene (HV-1900) to 60 parts. Made Sheets 1 and 2 in the same manner as in Example 1.

<Example 4>
After SiO ₂ was chemically vapor-deposited on the sheet 1 obtained in Example 1 at 30 nm, SiCN was chemically vapor-deposited at 30 nm. This was repeated to obtain a sheet 2 having a SiO ₂ -SiCN multilayer vapor deposition film composed of 6 SiO ₂ chemical vapor deposition layers + 6 SiCN chemical vapor deposition layers (total thickness 360 nm). Sheet 1 is the same as in Example 1.

<Example 5>
Sheet 2 was obtained by chemically vapor deposition of SiO and SiCN in the same manner as in Example 4 except that the mixture was changed to 3 layers of SiO ₂ chemical vapor deposition + 3 layers of SiCN chemical vapor deposition (total thickness 180 nm). Sheet 1 is the same as in Example 1.

<Example 6>
Sheet 1 was prepared in the same manner as in Example 4 except that the semi-baked hydrotalcite (DHT-4C) was removed, and the same SiO ₂ -SiCN multi-layer vapor deposition film (SiO ₂ chemical vapor deposition layer 6 layers) as in Example 4 was prepared. + SiCN chemical vapor deposition layer 6 layers, total thickness 360 nm) was formed to obtain Sheet 2.

<Example 7>
Sheet 2 was obtained in the same manner as in Example 6 except that the mixture was changed to 3 layers of SiO ₂ chemical vapor deposition + 3 layers of SiCN chemical vapor deposition (total thickness 180 nm). Sheet 1 is the same as in Example 6.

<Example 8>
Sheets 1 and 2 were prepared in the same manner as in Example 4 except that the ethylene-methylmethacrylate copolymer (CM5022) was changed to the propylene-butene copolymer (X1102).

<Example 9>
Sheet 2 was obtained in the same manner as in Example 8 except that the mixture was changed to 3 layers of SiO ₂ chemical vapor deposition + 3 layers of SiCN chemical vapor deposition (total thickness 180 nm). Sheet 1 is the same as in Example 8.

<Comparative Example 1>
Sheet 2 was obtained in the same manner as in Example 1 except that the coating agent was changed from OlamZ to SSG HB21N. Sheet 1 is the same as in Example 1.

<Comparative Example 2>
Sheet 2 was obtained in the same manner as in Example 1 except that the coating agent was changed from OlamZ to G401. Sheet 1 is the same as in Example 1.

<Comparative Example 3>
Sheet 2 was obtained in the same manner as in Example 1 except that the coating agent was changed from OlamZ to SZ-90. Sheet 1 is the same as in Example 1.

<Comparative Example 4>
Sheet 2 was obtained in the same manner as in Example 1 except that the coating agent was changed from OlamZ to SA1-92-52. Sheet 1 is the same as in Example 1.

<Comparative Example 5>
Sheet 2 was obtained in the same manner as in Example 1 except that the coating agent was changed from OlamZ to GB1-92. Sheet 1 is the same as in Example 1.

<Comparative Example 6>
Sheet 2 was obtained in the same manner as in Example 1 except that the coating agent was changed from OlamZ to G1-90. Sheet 1 is the same as in Example 1.

The moisture permeation resistance (water vapor permeation amount) of the sealing sheets of Examples and Comparative Examples obtained as described above was evaluated as follows. The results are shown in Tables 1 and 2. The number of copies of Alcon P125 and CM5022 in the material composition of the pressure-sensitive adhesive resin composition layer in Tables 1 and 2 is a solid content conversion value.

[Evaluation of moisture permeation resistance (water vapor permeation amount) of sealing sheet]
(1) The amount of water vapor permeation per 1 m ² of the pressure-sensitive adhesive resin composition layer (thickness: 45 μm) exfoliated from the support (PET film) of the sheet 1 and having no inorganic film is determined by JIS Z 0208: 1976. The measurement was carried out under the conditions of a temperature of 40 ° C., a humidity of 90% RH and 24 hours by a method according to the above. This water vapor permeation amount is defined as the water vapor permeation amount I.
(2) The amount of water vapor permeation per 1 m ² of the pressure-sensitive adhesive resin composition layer (thickness: 45 μm) having an inorganic film peeled off from the support (PET film) of the sheet 2 is set to JIS Z 0208: 1976. The measurement was carried out under the conditions of a temperature of 40 ° C., a humidity of 90% RH and 24 hours by a conforming method. This water vapor permeation amount is referred to as water vapor permeation amount II.

(evaluation)
The evaluation was made according to the following criteria from the comparison between the water vapor permeation amount (water vapor permeation amount I) of the sheet 1 and the water vapor permeation amount (water vapor permeation amount II) of the sheet 2.
Very good (◎): Water vapor permeation amount II is less than 0.7 when water vapor permeation amount I is 1 (water vapor permeation amount II / water vapor permeation amount I <0.7).
Good (◯): The water vapor permeation amount II when the water vapor permeation amount I is 1 is 0.7 or more and less than 1 (0.7 ≦ water vapor permeation amount II / water vapor permeation amount I <1).
Defective (x): The water vapor permeation amount II is 1 or more when the water vapor permeation amount I is 1 (1 ≦ water vapor permeation amount II / water vapor permeation amount I).

As shown in Tables 1 and 2, from the comparison between Examples 1 to 9 and Comparative Examples 1 to 6, is it a silica glass coating made of a heat-treated product of a polysilazane-containing coating film on one side of the pressure-sensitive adhesive resin composition layer? Alternatively, it was found that the moisture permeability resistance of the sealing sheet was significantly improved by forming a vapor-deposited film of a silicon compound.

1 Pressure-sensitive adhesive resin composition layer 2 Moisture-proof inorganic film 3 Release-treated support 4 Circular polarizing plate 5 Adhesive layer 41 Phase difference film 42 Polarizers 10, 11 Sealing sheet

This application is based on Japanese Patent Application No. 2017-058073 filed in Japan, the contents of which are incorporated herein by reference in its entirety.

Claims (15)

(A) a pressure-sensitive adhesive resin composition layer, (B) a moisture-proof inorganic film directly formed on one side of the (A) pressure-sensitive adhesive resin composition layer, and (C) a release-treated support. (C) Release-treated support / (A) Pressure-sensitive adhesive resin composition layer / (B) Moisture-proof inorganic film laminated structure (B) Moisture-proof inorganic film (A) ) The pressure-sensitive adhesive resin composition has no base material or support on the surface opposite to the side of the layer, and (C) the release-treated support is (A) the pressure-sensitive adhesive resin composition. A sealing sheet that is a support on which one side on which the layer is formed is subjected to a mold release treatment. The sealing sheet according to claim 1, wherein the (B) moisture-proof inorganic film is a silica glass film made of (B1) a heat-treated product of a polysilazane-containing coating film, or (B2) an inorganic vapor-deposited film. .. The sealing sheet according to claim 2, wherein the polysilazane contains perhydroxypolysilazane. (B2) The sealing sheet according to claim 2, wherein the inorganic vapor-deposited coating is a silicon compound vapor-deposited coating. The sealing sheet according to claim 4, wherein the silicon compound vapor deposition film is a SiO ₂ -SiCN multilayer vapor deposition film including a SiO ₂ vapor deposition film and a SiCN vapor deposition film. The sealing sheet according to claim 5, wherein the SiO ₂ -SiCN multi-layer vapor deposition film is a SiO ₂ -SiCN multi-layer vapor deposition film in which a SiO ₂ -vapor film and a SiCN vapor-film film are alternately formed. (B) The sealing sheet according to any one of claims 1 to 6, wherein the moisture-proof inorganic film has a thickness of 1000 nm or less. (A) The sealing sheet according to any one of claims 1 to 7, wherein the pressure-sensitive adhesive resin composition layer has a thickness of 3 to 50 μm. (A) The sealing sheet according to any one of claims 1 to 8, wherein the pressure-sensitive adhesive resin composition layer contains a hygroscopic filler. (A) The sealing sheet according to any one of claims 1 to 9, wherein the pressure-sensitive adhesive resin composition layer contains a tackifier resin. (C) The sealing sheet according to any one of claims 1 to 10, wherein the release-treated support is a support having a moisture-proof property. The sealing sheet according to any one of claims 1 to 11, which is used for sealing an organic EL element. (B) A circularly polarizing plate is further adhered to the surface of the moisture-proof inorganic film on the side opposite to the side of the (A) pressure-sensitive adhesive resin composition layer, and is used as a sealing sheet for an organic EL element. The sealing sheet according to any one of claims 1 to 11. An organic EL device in which an organic EL element is sealed with the sealing sheet according to any one of claims 1 to 13. (A) A seal characterized by directly forming (B) a moisture-proof inorganic film by applying a polysilazane-containing coating liquid to one side of a pressure-sensitive adhesive resin composition layer and drying it, or by depositing an inorganic substance. How to manufacture a stop sheet.

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