TW201900833A - Sealing sheet - Google Patents

Abstract

The present invention provides a sealing sheet, which is a sealing sheet having a first film, a resin composition layer, and a second film, wherein the resin composition layer is present between the first film and the second film, and the first The water vapor transmission rate of each of the first film and the second film is 1 (g / m ² / 24hr) or less.

Description

Sealing sheet

The present invention relates to a sealing sheet suitable for sealing an organic EL element.

Organic EL (Electroluminescence) devices are light-emitting devices that use organic materials in light-emitting materials, and have become the focus of much attention in recent years. However, the organic EL element is extremely weak against moisture and has problems such as a decrease in brightness due to moisture. In order to protect the organic EL element from moisture, the organic EL element is sealed using a sealing sheet having a resin composition layer.

The sealing sheet is generally composed of a support, a resin composition layer, and a cover film for protecting the resin composition layer (for example, Patent Document 1).

Moreover, as a method of improving the moisture blocking property of the sealing sheet, it is known to mix a semi-sintered hydrotalcite with the resin composition layer of the sealing sheet (for example, Patent Document 2). [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2016-186843 [Patent Document 2] International Publication No. 2017/135112

[Problems to be Solved by the Invention]

Paragraphs [0015] and [0016] of Patent Document 1 describe using a plastic film such as polyethylene terephthalate or a plastic film having a barrier layer as a support. However, in this paragraph [0018], only "the cover film used as the sealing sheet is the same as the support film" is described, and the use of a plastic film having a barrier layer as the cover film is not described.

When a plastic film having no barrier layer and high moisture permeability is used as a cover film of the sealing sheet, there is a concern that moisture transmitted through the cover film is mixed into the resin composition layer during storage of the sealing sheet. As a result, the self-moisture-protecting organic EL element of the sealing sheet is degraded. If the organic EL element is sealed by using such a sealing sheet, there is a concern that the life of the organic EL device will be shortened.

In addition, the sheet for sealing having a resin composition layer containing a semi-sintered hydrotalcite can achieve a high moisture blocking property by the semi-sintered hydrotalcite, but the semi-sintered hydrotalcite has a property of reversible absorption and release of moisture . Therefore, in the sealing sheet containing the semi-sintered hydrotalcite-containing resin composition layer, for example, during storage of the sealing sheet, the semi-sintered hydrotalcite absorbs moisture, and then the absorbed moisture is released to the resin composition layer. If the organic EL element is sealed with the resin composition layer containing the moisture thus emitted, there is a concern that the life of the organic EL device will be shortened.

The present invention has been made focusing on the above-mentioned matters, and the object of the present invention is to provide sealing for suppressing water absorption of a resin composition layer (especially, water absorption of a resin composition layer containing semi-sintered hydrotalcite) during storage and the like. Flakes. [Means to solve the problem]

In order to achieve the above object, the inventor repeated the results of intensive studies, and found that the water vapour transmission rate (hereinafter referred to as "WVTR") measured by using the method described in the examples described later in two tablets It is a film of 1 (g / m ² / 24hr) or less (hereinafter referred to as a "moisture-resistant film"). The presence of the resin composition layer therebetween can suppress water absorption of the resin composition layer (in particular, water absorption of the resin composition layer containing semi-sintered hydrotalcite). The present invention based on this knowledge is as follows.

[1] A sealing sheet, which is a sealing sheet having a first film, a resin composition layer, and a second film, wherein the resin composition layer is present between the first film and the second film, and the first The water vapor transmission rate of the film and the second film are each 1 (g / m ² / 24hr) or less.

[2] The sheet for sealing as described in [1] above, wherein the water vapor transmission rate of the first film and the second film is 0.01 (g / m ² / 24hr) or more and 1 (g / m ² / 24hr), respectively. the following. [3] The sheet for sealing as described in [1] above, wherein the water vapor transmission rate of the first film and the second film are each 0.01 (g / m ² / 24hr) or more and 0.5 (g / m ² / 24hr) the following. [4] The sheet for sealing as described in [1] above, wherein the water vapor transmission rate of the first film and the second film is 0.01 (g / m ² / 24hr) or more and 0.2 (g / m ² / 24hr), respectively. the following. [5] The sheet for sealing as described in the above [1], wherein the water vapor transmission rate of the first film and the second film are each 0.05 (g / m ² / 24hr) or more and 0.2 (g / m ² / 24hr) the following.

[6] The sheet for sealing as described in [1] above, wherein the water vapor transmission rate of the first film is less than 0.01 (g / m ² / 24hr), and the water vapor transmission rate of the second film is 0.01 (g / m ² / 24hr) or more and 1 (g / m ² / 24hr) or less.

[7] The sheet for sealing according to the above [6], wherein the water vapor transmission rate of the first film is 0.005 (g / m ² / 24hr) or less. [8] The sheet for sealing as described in [6] above, wherein the water vapor transmission rate of the first film is 0.001 (g / m ² / 24hr) or less. [9] The sheet for sealing as described in [6] above, wherein the water vapor transmission rate of the first film is 0.0005 (g / m ² / 24hr) or less.

[10] The sealing sheet according to any one of [6] to [9], wherein the water vapor transmission rate of the second film is 0.01 (g / m ² / 24hr) or more and 0.5 (g / m ² / 24hr) or less. [11] The sheet for sealing according to any one of [6] to [9], wherein the water vapor transmission rate of the second film is 0.01 (g / m ² / 24hr) or more and 0.2 (g / m ² / 24hr) or less. [12] The sheet for sealing according to any one of [6] to [9], wherein the water vapor transmission rate of the second film is 0.05 (g / m ² / 24hr) or more and 0.2 (g / m ² / 24hr) or less.

[13] The sheet for sealing as described in [1] above, wherein the water vapor transmission rate of the first film is 0.0005 (g / m ² / 24hr) or less, and the water vapor transmission rate of the second film is more than 0.0005 (g / m ² / 24hr), less than 0.01 (g / m ² / 24hr).

[14] The sheet for sealing according to any one of the above [1] to [13], wherein the first film and the second film are films having a base material and a barrier layer. [15] The sealing sheet as described in [14] above, wherein the base material is a plastic film. [16] The sheet for sealing according to the above [14] or [15], wherein the barrier layer includes an inorganic film.

[17] The sealing sheet according to any one of the above [1] to [16], wherein the resin composition layer includes an olefin-based resin and / or an epoxy resin. [18] The sheet for sealing according to any one of [1] to [17] above, wherein the resin composition layer is made of semi-sintered hydrotalcite.

[19] The sheet for sealing according to any one of the above [1] to [18], wherein the first film is a film having a release layer. [20] The sealing sheet according to any one of [1] to [19], wherein the first film and the second film are films having a release layer.

[21] The sealing sheet according to any one of the above [1] to [20], wherein the sealing sheet is for sealing an organic EL element. [Effect of the invention]

According to the present invention, water absorption of the resin composition layer of the sealing sheet (in particular, water absorption of the resin composition layer containing semi-sintered hydrotalcite) can be suppressed.

The sealing sheet of the present invention includes a first film, a resin composition layer, and a second film, and both the first film and the second film are moisture-proof films. The moisture-proof film may be a laminated film. The first film and the second film may be the same or different. The values of the WVTR of the first film and the second film may be the same or different. In addition, those having a thickness of less than 0.25 mm are classified as films and those having a thickness of more than 0.25 mm are classified as thin films according to JIS and the like, but the present invention is not limited by such classification.

The WVTR system of the moisture-resistant film is preferably 0.01 (g / m ² / 24hr) or more, 1 (g / m ² / 24hr) or less, preferably 0.5 (g / m ² / 24hr) or less, and more preferably 0.2 (g / m ² / 24hr). This WVTR is a value measured by a method described in Examples described later.

The WVTR of the moisture-proof film used as the first film and the second film can be appropriately set to an ideal state by the structure of the organic EL device to which the sealing sheet of the present invention is applied.

When a layer having a high moisture-proof property is provided in the structure of the organic EL device, the first film (support) of the present invention uses a moisture-proof film having a WVTR of less than 0.01 (g / m ² / 24hr) ( Hereinafter, it may be referred to simply as "high moisture-resistant film"). The WVTR of the highly moisture-resistant film is preferably 0.005 (g / m ² / 24hr) or less, more preferably 0.001 (g / m ² / 24hr) or less, and particularly preferably 0.0005 (g / m ² / 24hr) or less. The lower limit of the WVTR of the highly moisture-resistant film is not particularly limited, and a lower value is ideal, and 0 (g / m ² / 24hr) is most preferable. In this case, the second film (cover film) is peeled off and discarded during sealing. Therefore, as the second film, from the viewpoint of simultaneously suppressing water absorption and cost reduction of the resin composition layer during storage, a WVTR of 0.01 (g / m ² / 24hr) or more and 1 (g / m ² / 24hr) or less is used. A moisture-resistant film (hereinafter, referred to as "medium moisture-resistant film" for short) is preferable. In this case, the WVTR of the medium moisture-proof film is considered from the balance of moisture resistance and cost, and is more preferably 0.05 (g / m ² / 24hr) or more, and more preferably 0.5 (g / m ² / 24hr) or less. Is more preferably 0.2 (g / m ² / 24hr) or less.

For example, when the WVTR of the first film has extremely high moisture resistance of 0.0005 (g / m ² / 24hr) or less, as the second film, a WVTR of more than 0.0005 (g / m ² / 24hr) may be used. ), Moisture-resistant film less than 0.01 (g / m ² / 24hr). WVTR is a moisture-proof film having a thickness of 0.0005 (g / m ² / 24hr) or less as a barrier layer. Generally, a plastic film is formed by forming a plurality of layers of an inorganic film by evaporation or the like, which becomes a high cost. On the other hand, as a moisture-proof film having a WVTR of more than 0.0005 (g / m ² / 24hr) and less than 0.01 (g / m ² / 24hr), for example, a metal foil-attached plastic can be used at a relatively low cost. film. Therefore, by setting the first film and the second film as described above, it is possible to use a sealing film that achieves a balance between water absorption and cost reduction of the resin composition layer during storage. In terms of lower cost, it is preferable to use the above-mentioned moisture-proof film as the second film.

In addition, as both the first film and the second film, if an opaque moisture-proof film such as a film with a metal foil is used, the quality inspection of the resin composition layer becomes difficult. When one of the films uses an opaque moisture-proof film, the other is preferably a transparent moisture-proof film. The transparency of the transparent moisture-proof film does not depend on the thickness, and the total light transmittance of D65 light is preferably 85% or more. The "opaque moisture-resistant film" is defined as "a moisture-resistant film with a total light transmittance of D65 light of 50% or less". The total light transmittance can be measured with D65 light using Haze meter-HZ-V3 (halogen lamp) manufactured by Suga Testing Machine Co., Ltd., using air as a reference.

In the structure of the organic EL device, when the inorganic film is directly provided on the sealing layer formed of the resin composition layer, or when a high moisture resistance layer is not required, and a high humidity resistance layer is not provided, the first film and the Both of the second films are preferably the above-mentioned intermediate moisture-proof films.

In addition, when one or both of the first film and the second film uses a low moisture-proof film having a WVTR of more than 1 (g / m ² / 24hr), it is difficult to obtain the effects of the present invention.

The moisture-proof film is preferably a film having a substrate and a barrier layer. Here, the term "base material" means a part of the film other than the barrier layer.

The substrate may be a single-layer film or a laminated film. Examples of the base material include polyolefins such as polyethylene, polypropylene (PP), polyesters such as polyethylene terephthalate (PET), and polyethylene naphthalate (PEN), and polycarbonate Ester (PC), polyimide (PI), cyclic olefin polymer (COP), polyvinyl chloride and other plastic films. There may be only one type of plastic film, or two or more types. The base material is preferably a polyethylene terephthalate film, a cycloolefin polymer film, a polyethylene naphthalate film, or a polycarbonate film, and more preferably a polyethylene terephthalate film or a cycloolefin. Polymer film. The thickness of the substrate (when the substrate is a laminated film is the entire thickness) is preferably 10 to 100 μm, more preferably 12.5 to 75 μm, and even more preferably 12.5 to 50 μm.

Examples of the barrier layer system include inorganic films such as metal foil (for example, aluminum foil), silicon dioxide vapor-deposited film, silicon nitride film, and silicon oxide film. The barrier layer layer may also be composed of a plurality of layers of a plurality of inorganic films (for example, a metal foil and a silicon dioxide vapor-deposited film). The barrier layer system may be composed of an organic substance and an inorganic substance, or may be a composite multilayer of an organic layer and an inorganic film. The thickness of the barrier layer is preferably 0.01 to 100 μm, more preferably 0.05 to 50 μm, and still more preferably 0.05 to 30 μm.

WVTR is a moisture-resistant film (high moisture-resistant film) of less than 0.01 (g / m ² / 24hr), especially a moisture-resistant film with a WVTR of 0.0005 (g / m ² / 24hr) or less The surface of the substrate is an inorganic film of silicon oxide (silicon dioxide), aluminum oxide, magnesium oxide, silicon nitride, silicon oxynitride, SiCN, amorphous silicon, etc., by chemical vapor deposition (for example, by thermal, electrical Plasma, UV, vacuum heat, vacuum plasma or vacuum UV-induced chemical vapor deposition), or physical vapor deposition (for example, vacuum evaporation, sputtering, ion plating, laser) Stacking method, molecular beam epitaxy method), and the like, and laminated in a single layer or a multilayer (for example, refer to Japanese Patent Laid-Open No. 2016-185705, Japanese Patent No. 5719106, Japanese Patent No. 5712509, Japanese Patent No. 5292358 Bulletin, etc.). In order to prevent cracking of the inorganic film, it is desirable to alternately laminate the inorganic film and a transparent planarization layer (for example, a transparent plastic layer). The moisture-resistant film produced by such a method is a film having transparency.

In addition, in the moisture-proof film (high moisture-proof film) having a WVTR of less than 0.01 (g / m ² / 24hr), the WVTR is more than 0.0005 (g / m ² / 24hr) and less than 0.01 (g / m ² / 24hr), in addition to the moisture-resistant film produced by the above method, for example, a metal foil such as SUS foil, aluminum foil, or a base material and a metal foil are pasted through an adhesive. A moisture-resistant film made by a combination of methods. A metal foil or a moisture-proof film composed of a base material and a metal foil is usually opaque.

A moisture-proof film (medium moisture-proof film) having a WVTR of 0.01 (g / m ² / 24hr) or more and 1 (g / m ² / 24hr) or less is used as a barrier layer, for example, and may be deposited on the surface of the substrate. A method for coating inorganic films such as silicon oxide (silicon dioxide), aluminum oxide, magnesium oxide, silicon nitride, silicon oxynitride, SiCN, and amorphous silicon, or coating a substrate with a metal oxide and a barrier A coating liquid composed of a flexible organic resin is produced by a method such as drying (for example, refer to Japanese Patent Application Laid-Open No. 2013-108103, Japanese Patent No. 4028353, etc.). The moisture-resistant film produced by such a method is a film having transparency.

A commercially available product is also used as the moisture-proof film. Examples of commercially available products of the medium humidity resistance film include "KURARISTER CI" manufactured by Kuraray Corporation, "TECHBARRIER HX", "TECHBARRIER LX" and "TECHBARRIER L" manufactured by Mitsubishi Resin Corporation, and "IB- "PET-PXB", "GL, GX series" by Toppan Printing Co., Ltd., and other commercially-available products of the high-moisture-resistant film include, for example, "PET luck AL1N30" manufactured by Toyo Aluminum Co., Ltd., and "X-BARRIER" manufactured by Mitsubishi Plastics Corporation "Wait.

The moisture-proof film may have a layer other than the base material and the barrier layer. For example, in order to prevent cracking of the inorganic film, it is desirable to alternately laminate the inorganic film and a transparent planarization layer (for example, a transparent plastic layer). Furthermore, it may have a laminated structure in which a plastic film is bonded to the barrier layer and / or the substrate surface using an adhesive. In the present invention, the adhesive is not particularly limited, and a commercially available adhesive can be used. Examples of the plastics include polyolefins such as polyethylene and polypropylene (PP), polyesters such as polyethylene terephthalate (PET), and polyethylene naphthalate (PEN). Carbonate (PC), polyimide (PI), cyclic olefin polymer (COP), polyvinyl chloride, etc. There may be only one type of plastic film, or two or more types.

In the sealing sheet of the present invention, the resin composition layer is present between the first film and the second film. Between the first film and the resin composition layer and / or between the second film and the resin composition layer, other layers may be included as long as the effect of the present invention is not hindered. The second thin film to be the cover film is peeled in order to expose the resin composition layer before the sealing film is laminated on the organic EL element. The first film as a support is used as it is without peeling when it is mounted on a device as a moisture-proof layer, and is peeled off at any step after lamination when it is not mounted. Since the second film to be the cover film is to be easily peeled, a release layer may be provided on the surface in contact with the resin composition layer. In addition, the first film to be a support may be peeled off in a step after lamination without being mounted on a device, and for example, a release layer may be provided on a surface in contact with the resin composition layer. When the first film is mounted on the device and is not peeled off, the first film generally does not have a release layer. When a moisture-proof layer is provided in an organic EL device, the first film may be used as a moisture-proof layer as it is, or a moisture-proof layer may be separately provided after the first film is peeled off. When an organic EL device is provided with a moisture-proof layer, a circular polarizer, a color filter, or a touch panel, a circular polarizer, a color filter, or Touch panel. The circularly polarizing plate is generally composed of a polarizing plate and a 1/4 wavelength plate, and the 1/4 wavelength plate of the circular polarizing plate is arranged on a resin composition layer.

The release layer can be formed, for example, by applying a release agent to a moisture-resistant film or a laminated film including a moisture-resistant film, and drying it. In addition, a plastic film having a mold release layer may be formed by applying a mold release agent to a plastic film and dried to form a plastic film having a mold release layer. Then, an adhesive is used to attach the plastic film having the mold release layer to the moisture-proof film. The drying temperature after application of the release agent is, for example, 100 to 150 ° C, and the drying time is, for example, 5 to 120 minutes.

Examples of the release agent system include a silicone release agent, an alkyd release agent, a fluorine release agent, and an olefin release agent. The release layer is preferably formed of a polysiloxane-based release agent or an alkyd-based release agent. The thickness of the release layer is preferably 0.05 to 1 μm, more preferably 0.05 to 0.5 μm, and still more preferably 0.05 to 0.1 μm.

The thickness of the first film (when the first film is a laminated film is the thickness of the whole) is preferably 12.5 to 100 μm, more preferably 12.5 to 62.5 μm, and even more preferably 12.5 to 55 μm. The thickness of the second film (when the second film is a laminated film is the entire thickness) is preferably 12.5 to 100 μm, more preferably 12.5 to 62.5 μm, and even more preferably 12.5 to 55 μm.

In the present invention, the resin composition layer is not particularly limited, and a generally known resin composition can be used to form the resin composition layer. In order to properly seal the organic EL element and the like, the resin composition layer preferably contains an olefin-based resin and / or an epoxy resin.

The olefin-based resin may be only one kind, or two or more kinds. The olefin-based resin is not particularly limited as long as it has a skeleton derived from an olefin monomer. It is suitable as an olefin resin vinyl resin, a propylene resin, a butene resin, and an isobutylene resin. These olefin-based resins may be homopolymers or copolymers of random copolymers, block copolymers, and the like. Examples of the copolymers include copolymers of two or more olefins, and copolymers of olefins with monomers other than olefins such as non-conjugated dienes and styrene. Examples of desirable copolymers include ethylene-non-conjugated diene copolymers, ethylene-propylene copolymers, ethylene-propylene-non-conjugated diene copolymers, ethylene-butene copolymers, and propylene-butenes. Copolymers, propylene-butene-non-conjugated diene copolymers, styrene-isobutylene copolymers, styrene-isobutylene-styrene copolymers, and the like. As the polyolefin-based resin system, for example, an isobutylene modified resin, a styrene-isobutylene modified resin, a modified propylene-butene resin, or the like can be preferably used.

From the viewpoint of excellent physical properties such as adhesiveness, the olefin-based resin is preferably composed of an olefin-based resin having an acid anhydride group (that is, a carbonyloxycarbonyl group (-CO-O-CO-)) and having At least one is selected from the group consisting of epoxy-based olefin-based resins, and it is preferable to include an olefin-based resin having an acid anhydride group and an olefin-based resin having an epoxy group.

Examples of the acid anhydride group include a group derived from succinic anhydride, a group derived from maleic anhydride, and a group derived from glutaric anhydride. The acid anhydride group may be one type, or two or more types. The olefin-based resin having an acid anhydride group can be obtained, for example, by graft-modifying an olefin-based resin under a radical reaction condition with an unsaturated compound having an acid anhydride group. Further, an unsaturated compound having an acid anhydride group may be radically copolymerized together with an olefin or the like. Similarly, the olefin-based resin having an epoxy group is unsaturated with an epoxy group such as glycidyl (meth) acrylate, 4-hydroxybutyl acrylate glycidyl ether, allyl glycidyl ether, etc. A compound can be obtained by graft-modifying an olefin-based resin under radical reaction conditions. Further, an unsaturated compound having an epoxy group may be radically copolymerized together with an olefin or the like.

The concentration of the acid anhydride group in the olefin resin having an acid anhydride group is preferably 0.05 to 10 mmol / g, and more preferably 0.1 to 5 mmol / g. The concentration of the acid anhydride group is the value of the acid value defined by the mg number of potassium hydroxide necessary to neutralize the acid present in 1 g of the resin in accordance with JIS K 2501. The amount of the olefin-based resin having an acid anhydride group in the olefin-based resin is preferably 0 to 70% by mass, and more preferably 10 to 50% by mass.

The epoxy group concentration in the olefin-based resin having an epoxy group is preferably from 0.05 to 10 mmol / g, and more preferably from 0.1 to 5 mmol / g. The epoxy group concentration is determined from the available epoxy equivalent in accordance with JIS K 7236-1995. The amount of the olefin-based resin having an epoxy group in the olefin-based resin is preferably 0 to 70% by mass, and more preferably 10 to 50% by mass.

The olefin-based resin is preferably from the viewpoint of imparting excellent physical properties such as moisture resistance, and includes both an olefin-based resin having an acid anhydride group and an olefin-based resin having an epoxy group. Such an olefin-based resin can form a crosslinked structure by reacting by heating an acid anhydride group and an epoxy group, and can be formed in a sealing layer (resin composition layer) excellent in moisture resistance and the like. The formation of the cross-linked structure may be performed after sealing. For example, in the case of an organic EL element, where the sealing target is a heat-resistant person, it is best to use a sealing film for sealing, and it is best to form the cross-linked structure first when manufacturing the sealing film. The ratio of the olefin-based resin having an acid anhydride group to the olefin-based resin having an epoxy group is not particularly limited as long as a suitable crosslinked structure can be formed, but the molar ratio of the epoxy group to the acid anhydride group (epoxy group: acid anhydride group) ) Is preferably 100: 10 to 100: 200, more preferably 100: 50 to 100: 150, and particularly preferably 100: 90 to 100: 110.

The number average molecular weight of the olefin-based resin is not particularly limited, but from the viewpoint of bringing about good coatability of the resin composition varnish and good compatibility with other components in the resin composition, it is preferably 1,000,000 or less, 750,000 The following are ideal, below 500,000 are more desirable, below 400,000 are more desirable, below 300,000 are more desirable, below 200,000 are particularly desirable, and below 150,000 are most desirable. On the other hand, from the viewpoints of preventing shrinkage and cracking during coating of the resin composition varnish, showing the moisture resistance of the formed resin composition layer, and improving mechanical strength, the number average molecular weight is preferably 1,000 or more. , More than 3,000 is more desirable, more than 5,000 is more desirable, more than 10,000 is more desirable, more than 30,000 is more desirable, and more than 50,000 is particularly desirable. The number-average molecular weight in the present invention is measured by a gel permeation chromatography (GPC) method (in terms of polystyrene). The number average molecular weight by the GPC method is specifically, as a measuring device, LC-9A / RID-6A manufactured by Shimadzu Corporation is used, and as a column, Shodex K-800P / K-804L / K- manufactured by Showa Denko Corporation is used as a column. 804L is measured using toluene as the mobile phase at a column temperature of 40 ° C and can be calculated using a calibration curve of standard polystyrene.

The olefin-based resin is preferably a non-crystalline one from the viewpoint of suppressing a decrease in fluidity due to thickening of the varnish. Here, the term “amorphous” means that the olefin-based resin does not have a clear melting point. For example, when a melting point is measured by DSC (differential scanning calorimetry) in an olefin-based resin, a clear peak is not observed.

The amount of the olefin-based resin is not particularly limited. From the viewpoint of good coatability, etc., when an olefin-based resin is used, the amount is preferably 80% by mass or less per resin composition layer as a whole (that is, the entire non-volatile content of each resin composition). 75% by mass is more ideal, 70% by mass is more desirable, 60% by mass is more desirable, 55% by mass is more desirable, and 50% by mass is particularly desirable. On the other hand, from the viewpoint of improving moisture resistance and transparency, the amount of the olefin-based resin is the entire amount of each resin composition layer (that is, the entire non-volatile content of each resin composition), 1 More than mass% is ideal, more than 3 mass% is more ideal, more than 5 mass% is more ideal, more than 7 mass% is more ideal, more than 10 mass% is more ideal, more than 35 mass% is particularly desirable, and 40 mass% The above is ideal.

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

Specific examples of the butene-based resin include "HV-1900" (polybutene, number average molecular weight: 2,900) manufactured by JX Energy, and "HV-300M" (maleic anhydride modified liquid) manufactured by Toho Chemical Industry Co., Ltd. Polybutene (modified product of "HV-300" (number average molecular weight: 1,400)), number average molecular weight 2,100, number of carboxyl groups constituting acid anhydride group: 3.2 per one molecule, acid value: 43.4 mg KOH / g , Acid anhydride group concentration: 0.77 mmol / g).

Specific examples of the styrene-isobutylene copolymer include "SIBSTAR T102" (styrene-isobutylene-styrene block copolymer, number average molecular weight: 100,000, styrene content: 30% by mass) manufactured by Kaneka Corporation, Starlight PMC's "T-YP757B" (maleic anhydride modified styrene-isobutylene-styrene block copolymer, anhydride group concentration: 0.464mmol / g, number average molecular weight: 100,000), Starlight PMC's "T-YP766" (Glycidyl methacrylate modified styrene-isobutylene-styrene block copolymer, epoxy group concentration: 0.638 mmol / g, number average molecular weight: 100,000), Starlight PMC Corporation "T-YP8920" (maleic anhydride Modified styrene-isobutylene-styrene copolymer, acid anhydride group concentration: 0.464 mmol / g, number average molecular weight: 35,800), Starlight PMC Company "T-YP8930" (glycidyl methacrylate modified styrene-isobutylene- Styrene copolymer, epoxy group concentration: 0.638 mmol / g, number average molecular weight: 48,700).

Specific examples of the ethylene-based resin or the propylene-based resin include "EPT X-3012P" manufactured by Mitsui Chemicals Corporation (ethylene-propylene-5-ethylene-2-norbornene copolymer, and "EPT manufactured by Mitsui Chemicals Corporation" 1070 "(ethylene-propylene-dicyclopentadiene copolymer) and" TAFMER A 4085 "(ethylene-butene copolymer) manufactured by Mitsui Chemicals.

Specific examples of the ethylene-methyl methacrylate copolymer include "T-YP429" (maleic anhydride modified ethylene-methyl methacrylate copolymer (per ethylene unit and methacrylic acid) manufactured by Starlight PMC Corporation). Total amount of methyl ester units: 100% by mass of methyl methacrylate units: 32% by mass, acid anhydride group concentration: 0.46mmol / g, number average molecular weight: 2,300), 20% by mass toluene solution), manufactured by Starlight PMC T-YP430 "(maleic anhydride modified ethylene-methyl methacrylate copolymer, the total amount of methyl methacrylate units per ethylene unit and methyl methacrylate unit is 100% by mass: 32% by mass, Concentration of acid anhydride group: 1.18 mmol / g, number average molecular weight: 4,500), "T-YP 431" (glycidyl methacrylate modified ethylene-methyl methacrylate copolymer) (epoxy group concentration: 0.64mmol / g, number-average molecular weight: 2,400) in a 20% by mass toluene solution), "T-YP 432" (glycidyl methacrylate modified ethylene-methyl methacrylate copolymer) manufactured by Starlight PMC, epoxy Base concentration: 1.63mmol / g, number average molecular weight: 3,100 ).

Specific examples of the propylene-butene copolymer include "T-YP341" (glycidyl methacrylate modified propylene-butene random copolymer) (per propylene unit and butene unit total 100) Amount of butene unit by mass: 29% by mass, epoxy group concentration: 0.638 mmol / g), 20% by mass Swasol solution of number average molecular weight: 155,000), "T-YP279" (Malay) manufactured by Starlight PMC Corporation Acid anhydride modified propylene-butene random copolymer, the amount of butene units per 100 mass% of the total of propylene units and butene units: 36% by mass, the concentration of anhydride groups: 0.464mmol / g, the number average molecular weight: 35,000), "T-YP276" (glycidyl methacrylate modified propylene-butene random copolymer manufactured by Starlight PMC), the amount of butene units per 100% by mass of the total of propylene units and butene units: 36% by mass, ring Oxygen concentration: 0.638 mmol / g), number average molecular weight: 57,000), "T-YP312" (maleic anhydride modified propylene-butene random copolymer, made by Starlight PMC) (100 per propylene unit and butene unit total) Amount of butene unit by mass%: 29% by mass, concentration of anhydride group: 0.464mm ol / g, 40% by mass toluene solution of number average molecular weight: 60,900), "T-YP313" (glycidyl methacrylate modified propylene-butene random copolymer, per propylene unit and butene unit) manufactured by Starlight PMC The total amount of 100% by mass of butene units: 29% by mass, epoxy group concentration: 0.638mmol / g, number average molecular weight: 155,000) (20% by mass toluene solution).

When the olefin-based resin is an olefin-based resin containing an epoxy group, an olefin-based resin that can react with an epoxy group and has a functional group other than an acid anhydride group may be used. Examples of the functional group include a hydroxyl group, a phenolic hydroxyl group, an amine group, a carboxyl group, and an acid anhydride group.

When the olefin-based resin is an olefin-based resin containing an acid anhydride group, an olefin-based resin that can react with the acid anhydride group and has a functional group other than an epoxy group may be used. Examples of the functional group include a hydroxyl group, a primary or secondary amine group, a thiol group, an epoxy group, and an oxetanyl group.

If the epoxy resin is an average and has two or more epoxy groups per molecule, it can be used without limitation. Examples of the epoxy resin system include a bisphenol A epoxy resin, a hydrogenated bisphenol A epoxy resin, a biphenyl epoxy resin, a biphenylaralkyl epoxy resin, a naphthol epoxy resin, Naphthalene-type epoxy resin, bisphenol F-type epoxy resin, phosphorus-containing epoxy resin, bisphenol S-type epoxy resin, aromatic glycidylamine-type epoxy resin (e.g., tetraglycidyl diamine diphenyl) Methane, triglycidyl-p-aminophenol, diglycidyl toluidine, diglycidyl aniline), alicyclic epoxy resin, aliphatic chain epoxy resin, phenol novolac epoxy resin, Cresol novolac epoxy resin, bisphenol A novolac epoxy resin, epoxy resin with butadiene structure, diglycidyl etherate of bisphenol, diglycidyl etherate of naphthalene glycol, phenols Diglycidyl etherate of alcohols, diglycidyl etherification of alcohols, and alkyl substituents, halides and hydrides of these epoxy resins. There may be only one type of epoxy resin, or two or more types.

The epoxy equivalent of the epoxy resin is considered from the viewpoint of reactivity, etc., preferably 50 to 5,000, more preferably 50 to 3,000, more preferably 80 to 2,000, more preferably 100 to 1,000, and more preferably 120 to 1,000. , Ideally 140 ~ 300. The "epoxy equivalent" is the number of grams (g / eq) of a resin containing 1 gram equivalent of an epoxy group, and is measured in accordance with a method prescribed by JIS K 7236. The weight average molecular weight of the epoxy resin is preferably 5,000 or less.

The epoxy resin may be either liquid or solid, and both liquid epoxy and solid epoxy may be used. Here, the "liquid state" and "solid state" refer to the state of the epoxy resin at normal temperature (25 ° C) and normal pressure (1 atmosphere).

The amount of the epoxy resin is not particularly limited. In the case of using epoxy resin, the amount is the whole of each resin composition layer (that is, the entire non-volatile content of each resin composition), preferably 20 to 80% by mass, and more preferably 30 to 70% by mass. 50 to 65% by mass is more preferable.

From the viewpoint of the moisture blocking property of the sealing sheet of the present invention, it is preferable that the resin composition layer contains semi-sintered hydrotalcite. The semi-sintered hydrotalcite may be only one kind, or two or more kinds.

The hydrotalcite series can be classified into unsintered hydrotalcite, semi-sintered hydrotalcite, and sintered hydrotalcite.

The unsintered 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). Mg _1-X Al _X (OH) ₂ ] ^{X +} and an intermediate layer [(CO ₃ ) _{X / 2} · mH ₂ O] ^X- . The unsintered hydrotalcite system of the present invention includes the concept of synthetic hydrotalcite and the like. Examples of the hydrotalcite-based compound include those represented by the following formula (I) and the following formula (II).

(In the formula, M ^{2 +} represents a divalent metal ion such as Mg _{2 +} , Zn ^{2 +,} etc., M ^{3 +} represents a trivalent metal ion such as Al ^{3 +} , Fe ^{3 +,} etc., and A ^n- represents CO _{^{3 2-, Cl -, NO 3}} - , etc. the n-valent anion, 0 <x <1,0 ≦ m <1, n is a positive number). In formula (I), the M ^{2 +} system is ideally Mg ^{2 +} , the M ^{3 +} system is ideally Al ^{3 +} , and the An ^n- system is ideally CO ₃ ^2- .

(Wherein, M ^{2 + line} represents Mg ^{2 +,} Zn ^{2 +} 2, etc. The divalent metal ion, A ^n- represents Department CO ₃ ^2-, Cl ^- anion of valence n, NO ^3-, etc., x is 2 For positive numbers above, z is a positive number below 2, m is a positive number, and n is a positive number). In the formula (II), the M ^{2 +} system is preferably Mg ^{2 +} , and the An ^n- system is preferably CO ₃ ^2- .

Semi-sintered hydrotalcite is a metal hydroxide obtained by sintering unsintered hydrotalcite and having a layered crystal structure in which the amount of interlayer water is reduced or disappeared. The "interlayer water" is described using a composition formula, and refers to "H ₂ O" described in the composition formula of the unsintered natural hydrotalcite and a hydrotalcite-like compound described above.

On the other hand, sintered hydrotalcites are called sintered unsintered hydrotalcites or semi-sintered hydrotalcites, which are not only interlayer water, but also hydroxyl groups that disappear due to condensation and dehydration, and have an amorphous metal oxide.

Unsintered hydrotalcite, semi-sintered hydrotalcite, and sintered hydrotalcite can be distinguished by saturated water absorption. The saturated water absorption of semi-sintered hydrotalcite is 1 mass% or more and less than 20 mass%. On the other hand, the saturated water absorption of the unsintered hydrotalcite is less than 1% by mass, and the saturated water absorption of the sintered hydrotalcite is 20% by mass or more.

The "saturated water absorption" in the present invention refers to measuring 1.5 g of unsintered hydrotalcite, semi-sintered hydrotalcite, or sintered hydrotalcite on a scale, and after measuring the initial mass, it is set at 60 ° C, 90 ° C under atmospheric pressure. The mass increase rate relative to the initial mass when the small-scale environmental tester (SH-222 manufactured by espec) is left for 200 hours at a relative humidity (relative humidity) can be expressed by the following formula (i): Saturated water absorption (mass%) = 100 × (mass after moisture absorption-initial mass) / initial mass (i).

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

The unsintered hydrotalcite, the semi-sintered hydrotalcite, and the sintered hydrotalcite system can be distinguished by a thermogravimetric reduction rate measured by thermogravimetric analysis. The thermal weight reduction rate of the semi-sintered hydrotalcite at 280 ° C is less than 15% by mass, and the thermal weight reduction rate at 380 ° C is 12% by mass or more. On the other hand, the thermal weight reduction rate of unsintered hydrotalcite at 280 ° C is 15% by mass or more, and the thermal weight reduction rate of sintered hydrotalcite at 380 ° C is less than 12% by mass.

Thermogravimetric analysis uses Hitachi High-Tech Science's TG / DTA EXSTAR6300. 5mg hydrotalcite can be weighed in an aluminum sample pan. It is open without a cover and under a nitrogen flow of 200mL / min. The temperature is from 30 ° C to 550 ° C at a temperature increase rate of 10 ° C / min. The thermal weight reduction rate can be expressed by the following formula (ii): Thermal weight reduction rate (mass%) = 100 × (mass before heating-mass at a specific temperature) / mass before heating (ii).

The unsintered hydrotalcite, the semi-sintered hydrotalcite, and the sintered hydrotalcite system can be distinguished by a wave peak and a relative intensity ratio measured by powder X-ray diffraction. Semi-sintered hydrotalcite appears by diffraction of powder X-rays. 2θ is a peak that is split into two peaks around 8 to 18 、, or a peak with a shoulder is formed by the combination of the two peaks and appears on the low-angle side. The relative intensity ratio (low angle) of the peak intensity or shoulder diffraction intensity (= low-angle side diffraction intensity) to the peak intensity or shoulder diffraction intensity (= high-angle side diffraction intensity) that appears on the high-angle side (Side diffraction intensity / high-angle side diffraction intensity) is 0.001 to 1,000. On the other hand, the unsintered hydrotalcite has only one peak near 8 ~ 18˚, or the relative intensity of the diffraction intensity between the peak or shoulder appearing on the low-angle side and the peak or shoulder appearing on the high-angle side. The ratio is outside the aforementioned range. The sintered hydrotalcite has no characteristic peaks in the region of 8˚-18˚, and has characteristic peaks in 43˚. The powder X-ray diffraction measurement was performed using a powder X-ray diffraction device (Empyrean, manufactured by PANalytical Co., Ltd.) with a cathode CuKα (1.5405Å), voltage: 45V, current: 40mA, sampling width: 0.0260˚, scanning speed: 0.0657 ˚ / s, measurement of diffraction angle range (2θ): 5.0131 to 79.9711 ˚. The crest search is based on the crest search function of the software attached to the diffraction device. It can be "minimum sense: 0.50, minimum crest search: 0.01˚, maximum crest search: 1.00", crest base width: 2.00 ", method: 2nd differential The minimum value ".

Semi-sintered BET specific surface area of the hydrotalcite-based 1 ~ 250m ² / g is desirable, 5 ~ 200m ² / g is more preferable. The BET specific surface area of the semi-sintered hydrotalcite can be calculated in accordance with the BET method using a specific surface area measuring device (Macsorb HM Model 1210 Mountech) to adsorb nitrogen gas on the surface of the sample and use the BET multi-point method.

The average particle size of the semi-sintered hydrotalcite is preferably 1 to 1,000 nm, and more preferably 10 to 800 nm. The average particle diameter of the semi-sintered 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 particle size distribution measurement (JIS Z 8825).

The semi-sintered hydrotalcite can be used as a surface treatment agent with a surface treatment agent. Examples of the surface treatment agent used for the surface treatment include higher fatty acids, alkylsilanes, and silane coupling agents. Among them, higher fatty acids and alkylsilanes are suitable. The surface treatment agent can be used alone or in combination of two or more.

Examples of the higher fatty acid system include stearic acid, montanic acid, myristic acid, palmitic acid, and the like, and higher fatty acids having a carbon number of 18 or more, among which stearic acid is particularly preferred. These systems can be used singly or in combination of two or more.

Examples of the alkylsilanes include methyltrimethoxysilane, ethyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, and octadecyltrimethoxysilane. Silyl, dimethyldimethoxysilane, octyltriethoxysilane, n-octadecyldimethyl (3- (trimethoxysilyl) propyl) ammonium chloride and the like. These systems can be used singly or in combination of two or more.

Examples of the silane coupling agent system include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, and 3-glycidyloxypropyl (dimethylformate) (Oxy) methylsilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, etc. epoxy-based silane coupling agents; 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltrisiloxane Mercapto-based silane coupling agents such as ethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 11-mercaptoundecyltrimethoxysilane; 3-aminopropyltrimethoxysilane, 3- Aminopropyltriethoxysilane, 3-aminopropyldimethoxymethylsilane, N-phenyl-3-aminopropyltrimethoxysilane, N-methylaminopropyltrimethoxy Silyl, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyldimethoxymethylsilane, etc. Amine-based silane coupling agents; urea-based silane coupling agents such as 3-ureidopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and vinylmethyldiethoxy Vinyl silane coupling agents such as silane; p-benzene Styryl-based silane coupling agents such as alkenyltrimethoxysilane; 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane; acrylate-based silane coupling agents Mixtures; isocyanate-based silane coupling agents such as 3-isocyanatepropyltrimethoxysilane, bis (triethoxysilylpropyl) disulfide, bis (triethoxysilylpropyl) tetrasulfide, etc. Sulfide-based silane coupling agents; phenyltrimethoxysilane, methacryloxypropyltrimethoxysilane, imidazolizane, triazinesilane, etc. These systems can be used singly or in combination of two or more.

The surface treatment of the semi-sintered hydrotalcite can be carried out by stirring and dispersing the untreated semi-sintered hydrotalcite at room temperature with a mixer, and by adding and spraying the surface treatment agent for 5 to 60 minutes. As the mixer system, generally known mixers can be used, and examples include blenders such as V-type blenders, belt blenders, bubble cone blenders, Henschel mixers, and concrete mixers. Mixer, ball mill, coarse grinder, etc. When the semi-sintered hydrotalcite is pulverized by a ball mill or the like, the above-mentioned higher fatty acid, alkylsilane, or silane coupling agent may be added for surface treatment. The amount of the surface treatment agent varies depending on the type of the semi-sintered hydrotalcite or the type of the surface treatment agent, but for 100 parts by mass of the semi-sintered hydrotalcite that has not been surface-treated, 1 to 10 parts by mass is ideal. . The semi-sintered hydrotalcite that has been surface-treated in the present invention is also included in the "semi-sintered hydrotalcite".

The amount of the semi-sintered hydrotalcite is not particularly limited. From the viewpoint of the moisture blocking property of the sealing sheet, in the case of using semi-sintered hydrotalcite, the amount is the whole of each resin composition layer (that is, the entire non-volatile content of each resin composition), 3 ~ 50% by mass is ideal, 5 ~ 45% by mass is ideal, and 10 ~ 40% by mass is more ideal.

Examples of the semi-sintered hydrotalcite system include "DHT-4C" (manufactured by Kyowa Chemical Industry Co., Ltd., average particle size: 400 nm), "DHT-4A-2" (manufactured by Kyowa Chemical Industry Co., Ltd., average particle size: 400 nm), and the like . Examples of the sintered hydrotalcite system include "KW-2200" (manufactured by Kyowa Chemical Industry Co., Ltd., average particle size: 400 nm). Examples of the unsintered hydrotalcite system include "DHT-4A" (Kyowa Chemical Industry Co., Ltd.) System, average particle size: 400 nm) and the like.

The resin composition layer system may contain other components different from the above-mentioned olefin-based resin, epoxy resin, and semi-sintered hydrotalcite system. There are no restrictions on other components, and generally known ones can be used as the components of the resin composition for sealing. Examples of other component systems include hardeners, hardening accelerators, other resins different from olefin-based resins and epoxy resins, other inorganic fillers different from semi-sintered hydrotalcites, and silane coupling agents. These other components may be only one kind, or two or more kinds.

When an olefin-based resin and / or epoxy resin having an epoxy group is used, it is preferable to use a hardener or a combination of a hardener and a hardening accelerator for the hardening.

In the present invention, the resin composition layer system may include another resin different from the olefin-based resin and the epoxy-based resin. Examples of the other resins include a tackifying resin and a thermoplastic resin (for example, a phenoxy resin) different from the olefin-based resin. The phenoxy resin may have an epoxy group similarly to an epoxy resin. The epoxy equivalent of the phenoxy resin is preferably more than 5,000 and less than 16,000, and more preferably more than 10,000 and less than 16,000.

In the present invention, the resin composition layer system may contain other inorganic fillers different from the semi-sintered hydrotalcite system. Examples of other inorganic fillers include unsintered hydrotalcite, sintered hydrotalcite, talc, silica, alumina, barium sulfate, clay, mica, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, Boron nitride, aluminum borate, barium titanate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, calcium zirconate, and the like. The amount of other inorganic fillers is the whole of each resin composition layer (that is, the entire non-volatile content of each resin composition), and is preferably 0 to 12% by mass, more preferably 0 to 10% by mass, and even more preferably 0. ~ 8% by mass.

The thickness of the resin composition layer is preferably 5 to 75 μm, more preferably 10 to 50 μm, and still more preferably 15 to 50 μm.

For example, the first film (support) is coated and dried with the resin composition varnish to form a resin composition layer, and the second film (covering film) is laminated on the obtained resin composition layer to produce the sealing sheet of the present invention. .

The resin composition varnish is prepared by mixing the components of the resin composition and an organic solvent by using a kneading drum, a rotary mixer, or the like. The non-volatile content of the resin composition varnish is preferably 20 to 80% by mass, and more preferably 30 to 70% by mass.

Examples of the organic solvent system include ketones such as acetone, methyl ethyl ketone (MEK), and cyclohexanone; ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and card Acetates such as acetol acetate; Cellulose and carbitol such as butyl carbitol; Aromatic hydrocarbons such as toluene and xylene; dimethylformamide and dimethylacetamidine Aromatic mixed solvents such as amines, N-methylpyrrolidone, etc .; Examples of the products of the aromatic mixed solvent include "Swasol" (manufactured by Maruzen Oil Co., Ltd.) and "Ipsol" (manufactured by Idemitsu Kosan Co., Ltd.). The organic solvent may be only one kind, or two or more kinds.

The drying conditions for forming the resin composition layer are not particularly limited, but the drying temperature is, for example, 80 to 130 ° C., and the drying time is, for example, 3 to 60 minutes. When the resin composition layer contains an epoxy resin, the drying temperature is preferably 80 to 100 ° C, and the drying time is preferably 5 to 90 minutes. When the resin composition layer does not contain an epoxy resin and contains an olefin-based resin, the drying temperature is preferably 80 to 130 ° C, and the drying time is preferably 15 to 60 minutes.

After the resin composition layer is formed on the first film, the second film is laminated on the obtained resin composition layer to produce a sealing sheet. After the resin composition layer is formed on the second film, the first film is laminated on the obtained resin composition layer, so that a sheet for sealing can also be produced. For lamination, a generally known machine can be used, for example, a roll laminator, a press, a vacuum pressure laminator, or the like. [Example]

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, and it is needless to say that the present invention can be appropriately modified and implemented within a range suitable for the above-mentioned and following interesting purposes. All are included in the technical scope of the present invention.

<Film> (1) The moisture-proof film used in the following Examples and Comparative Examples, a PET film with a release layer, and a WVTR measured by a method described later are described in Table 1 below.

In Examples 1 to 5 and Comparative Example 1, a sealing film was produced. The sealing film is a sealing layer (resin composition layer or a resin composition layer or an organic EL device) in which the first film (support) and the second film (covering film) are used together. It is assumed that the hardened layer is peeled off before and after the formation. In the sealing film of the example, the following moisture-proof film with a release layer is used. The moisture-proof film with a release layer is the first film and the second film together in the moisture-proof film of Table 1 above. A release layer is formed on the opposite side of the barrier layer. "Film A with polysiloxane release layer": A moisture-resistant film with a polysiloxane release layer is provided on the opposite side of the barrier layer of film A. "PET + film A with alkyd release layer": Moisture resistance of the surface on the opposite side of the release layer of PET with the alkyd release layer and the opposite side of the barrier layer of film A with an adhesive Film (55 μm thickness of the entire film). "PET + film A with polysiloxane release layer": The adhesive is applied to the surface of the opposite side of the release layer of PET with the polysiloxane release layer and the surface of the opposite side of the barrier layer of film A with an adhesive. Wet film (the thickness of the entire film is 55 μm). "PET + Film B with polysiloxane release layer": The surface of the opposite side of the release layer of PET with the polysiloxane release layer and the surface of the opposite side of the barrier layer of film B are bonded with an adhesive Wet film (the thickness of the entire film is 55 μm). "PET + film C with polysiloxane release layer": The adhesive is applied to the surface of the opposite side of the release layer of PET with the polysiloxane release layer and the surface of the opposite side of the barrier layer of film C with an adhesive. Wet film (the thickness of the entire film is 55 μm). "Film D with polysiloxane release layer": A moisture-resistant polysiloxane release layer (thickness of 55 μm) is provided on the opposite side of the barrier layer (aluminum foil) of film D. Sang Shang, "PET with polysiloxane release layer" used in Comparative Examples and Examples is a film in which a polysiloxane release layer is provided on one side of a polyethylene terephthalate film. Sang Shang, "PET with alkyd release layer" used in Comparative Examples and Examples is a film in which an alkyd release layer is provided on one side of a polyethylene terephthalate film.

<Production of Resin Composition Varnish> Production Example 1: Production of olefin-based resin composition varnish in 130 parts by mass of a 60% by mass Swasol solution in a cyclohexane-containing saturated hydrocarbon resin ("Alcon P125" manufactured by Arakawa Chemical Co., Ltd.) Three-roller dispersion of 35 parts by mass of maleic anhydride modified liquid polyisobutylene ("HV-300M" manufactured by Toho Chemical Industry Co., Ltd.), 60 parts by mass of polybutene ("HV-1900" manufactured by JX Energy) and semi-sintered water 100 parts by mass of talc ("DHT-4C" manufactured by Kyowa Chemical Industry Co., Ltd.) was used to obtain a mixture. 20 parts by mass of a 20% by mass Swasol solution of glycidyl methacrylate-modified polypropylene-polybutene copolymer ("T-YP341" manufactured by Starlight PMC Co., Ltd.), an anionic polymerization type hardener ( 0.5 parts by mass of 2,4,6-ginseno (diaminomethyl) phenol and 16 parts by mass of toluene, and the obtained mixture was uniformly dispersed with a high-speed rotary mixer to obtain an olefin-based resin composition varnish.

Manufacturing Example 2: Production of epoxy resin composition varnish Kneaded liquid bisphenol A type epoxy resin ("jER828EL" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight: about 185) 56 parts by mass of silane coupling agent (Shin-Etsu Chemical Industry Co., Ltd. ("KBM403") 1.2 parts by mass, 2 parts by mass of talc powder ("FG15" manufactured by Japan Talc Corporation) and 15 parts by mass of semi-sintered hydrotalcite ("DHT-4A-2" manufactured by Kyowa Chemical Industry Co., Ltd.) The mill was dispersed to obtain a mixture. 81 mass of a 35 mass% methyl ethyl ketone (MEK) solution in which 1.5 mass parts of a hardening accelerator ("U-3512T" manufactured by San-Apro Corporation) is dissolved in a phenoxy resin ("YL7213" manufactured by Mitsubishi Chemical Corporation) is dissolved. 30 parts by mass of an 80% by mass MEK solution of a solid bisphenol A type epoxy resin solution ("jER1001" manufactured by Mitsubishi Chemical Corporation), And organic solvent-dispersed colloidal silicon dioxide (amorphous silica particle size 10-15nm, non-volatile content: 30% by mass, solvent: MEK, "MEK-EC-2130Y" manufactured by Nissan Chemical Industries, Ltd.) 20 parts by mass And 3 parts by mass of an ionic liquid hardener (N-acetylammonium glycinate tetrabutylphosphonium salt) were uniformly dispersed in a high-speed rotary mixer to obtain an epoxy resin composition varnish.

The above-mentioned ionic liquid hardener (N-acetylammonium glycinate tetrabutylphosphonium salt) is synthesized by the following procedure. To 20.0 g of a 41.4% by mass aqueous solution of tetrabutylphosphonium hydroxide (manufactured by Beixing Chemical Industry Co., Ltd.), 3.54 g of N-acetylfluorenylglycinic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) was added at 0 ° C. and stirred for 10 minutes. The pressure was reduced to 40 to 50 mmHg using an evaporator, and concentrated at 60 to 80 ° C. for 2 hours and 90 ° C. for 5 hours. It was dissolved again in 14.2 ml of ethyl acetate (manufactured by Junzheng Chemical Co., Ltd.) at room temperature, reduced to 40 to 50 mmHg using an evaporator, and concentrated at 70 to 90 ° C for 3 hours. 11.7 g (purity: 96.9% by mass) of N-acetylammonium glycinic acid tetrabutylphosphonium salt was obtained as an oily compound.

<Manufacture of sealing sheet> Example 1 PET + film A with a polysiloxane release layer was used as the first film, and film A with a polysiloxane release layer was used as the second film. The olefin-based resin composition varnish obtained in Production Example 1 was uniformly coated on a mold release layer of the first film with a mold coater and heated at 130 ° C. for 60 minutes to obtain a resin composition having a thickness of 20 μm. Sheet for sealing (the amount of residual solvent in the resin composition layer: about 1% by mass). Next, the obtained sealing composition sheet was brought into contact with the resin composition layer of the second film and the release layer of the second film was bonded together, and the sealing sheet was wound into a roll shape. The roll-shaped sealing sheet was cut lengthwise to 507 mm to obtain a sealing sheet having a size of 507 × 336 mm. The structure of the obtained sealing sheet is shown in Table 2 below.

Examples 2 to 10 and Comparative Examples 1 to 3 The films shown in Tables 2 and 3 below were used as the first film or the second film, except that the olefin-based resin composition varnish obtained in Production Example 1 or 2 was used. Except for the epoxy resin composition varnish to form the resin composition layer, the sealing sheet (the thickness of the resin composition layer) of Examples 2 to 10 and Comparative Examples 1 to 3 was produced in substantially the same manner as in Example 1. 20 μm). The structure of the obtained sealing sheet is shown in Tables 2 and 3 below.

In Example 10 and Comparative Example 3 using the epoxy resin composition varnish, the epoxy resin composition varnish was applied, and then dried at 80 to 100 ° C (average 90 ° C) for 5 minutes to form an epoxy resin composition. Layer (residual solvent amount in the resin composition layer: about 2% by mass).

In Examples 6 to 10 and Comparative Examples 2 and 3 where the film X or the film E without the release layer was used as the first film, the resin composition layer on the second film and the barrier layer of the first film were In the contact method, the sealing sheet is wound into a roll shape while being bonded together.

<Measurement method> (1) Measurement of water vapor transmission rate (WVTR) The water vapor transmission rate of the films A to X, polysiloxane peeled PET, and alkyd peeled PET described in Table 1 is as follows. Perform and measure. First, a test piece punched out of a film to a diameter of 60 mmφ was produced. According to JIS Z 0208: 1976, 7.5 g of calcium chloride was measured in an aluminum moisture-permeable cup having a transmission area of 2.826 × 10 ^-3 m ² (60 mmφ), and a test piece was mounted in the moisture-permeable cup. Put calcium chloride, and measure the initial mass of the moisture-permeable cup with the test piece installed on a precision balance. Next, in a constant temperature test room at a temperature of 40 ° C and a humidity of 90% RH, the moisture-permeable cup was left for 24 hours, and then calcium chloride was added. Determination. The mass increase amount (= mass after moisture transmission-initial mass) was set as the water vapor transmission amount, and the water vapor transmission rate (g / m ² / 24hr) was calculated from the water vapor transmission amount, the transmission area, and the standing time. .

(2) Measurement of water content 1 含水 The water content of the resin composition layer before and after the sealing sheet manufactured in Examples 1 to 5 and Comparative Example 1 was left to be measured in the following manner.

First, the sealing sheet was cut to 7 cm square within 8 hours after production, and the resin composition layer obtained by peeling off the first and second films was used as a sample before leaving. The water content was measured by the electric titration method. The measurement was carried out by a Karl Fischer moisture measuring device ("a trace moisture measuring device CA-200" manufactured by Mitsubishi Chemical Analytech). The water content before standing is shown in Table 2 below.

The device is composed of a glass container in which a sample that can be heated is provided, and a titration device that contains a reaction liquid that titrates the water vaporized when the sample is heated. The vaporized water is moved from the glass container to the reaction liquid side of the titration device through a flow rate of 250 ± 25 ml / min nitrogen. The measurement is carried out in a glass container which has been replaced with a nitrogen environment (water vapor amount <0.1 ppm (mass standard)), a sample is placed, and the amount of vaporized water is titrated at 130 ° C to calculate the resin composition layer. Water content. The unit "ppm" of the water content described below is the mass basis.

After the sealing sheet cut into 7 cm squares was left to stand for 7 days in an environment with a temperature of 25 ° C. and a humidity of 50% RH, the resin composition layer obtained by peeling off the first and second films was left in the same manner as above. A sample was used and the water content was measured in the same manner. The water content after standing is shown in Table 2 below.

Calculate the ratio of the measured water content after storage to the water content before storage in the above manner (that is, the water content after storage / water content before storage, hereinafter referred to as the "water content ratio") . This ratio is also shown in Table 2 below.

From the moisture content after leaving, and the ratio of the moisture content after leaving to the moisture content before leaving, the sealing sheet was evaluated on the following basis. This result is also shown in the following table. (Basis of water content) ○ (Good): The water content after storage is less than 9000ppm, and the ratio of water content is less than 1.5 △ (Possible): The water content after storage is less than 9000ppm, and the ratio of water content It is 1.5 or more, or the water content after storage is 9000 ppm or more, and the ratio of the water content is less than 1.5 × (bad): The water content after storage is 9000 ppm or more, and the water content ratio is 1.5 or more

(3) Measurement of water content 2 2 Except that the second film was cut to 7 cm square and the second film was peeled off, the sealing sheets of Examples 6 to 10 and Comparative Examples 2 and 3 (that is, the resin composition cut to 7 cm square) The laminated body of the first layer and the first thin film) is used as a sample for measuring the water content, and the measurement is performed in the same manner as in the measurement of the water content 1 except that the water content before and after the standing is measured, and the water content ratio is calculated based on the above reference Evaluation. The results are shown in Table 3 below.

(4) The measurement of the light-emitting area reduction start time was performed in a manner described later, and the organic EL element was sealed using the sealing sheets before and after being placed in Examples 1, 2, 4, 7, and 8, and Comparative Examples 1 to 3, and the measurement was performed. The light emission area reduction start time was evaluated. As the sealing sheet before being left to stand, a sealing sheet within 24 hours after manufacture was used. In addition, as the sealing sheet after being left to stand, a sealing sheet left to stand for 7 days under an environment of a temperature of 25 ° C. and a humidity of 50% RH) was used.

The sealing sheet of Examples 1, 2 and 4 and Comparative Example 1 was peeled using the second film, and the PET sheet AL1N30 was bonded to the sealing sheet. The first film was peeled off, and the organic EL device was sealed in a manner described later. In the sealing sheets of Examples 7 and 8 and Comparative Examples 2 and 3, the sealing sheet (that is, a laminate of the resin composition layer and the first film) from which the second film was peeled was used, and sealed as described later. Organic EL element.

The alkali-free glass was 25 mm × 25 mm square, washed with boiled isopropyl alcohol for 5 minutes, and dried at 150 ° C. for more than 30 minutes. Using a mask with a distance of 4 mm from the end, on the aforementioned glass, vapor deposition was performed in the following sequence on hexaazatriphenylbenzonitrile (HATCN) (thickness 10 nm), 9,9'-diphenyl -6- (9-phenyl) -9H-carbazol-3-yl) -9H, 9'H-3,3'-biscarbazole (TrisPCz) (thickness 40nm), 5% by mass of 9,10 -Bis (N, N-di-p-tolylamino) anthracene (TTPA) -ginseng (8-hydroxyquinoline) aluminum (Alq3) (thickness 30nm), ginseng (8-hydroxyquinoline) aluminum (Alq3) ( 30 nm in thickness), LiF (0.5 nm in thickness), Mg-Ag (5 nm in thickness), and an organic EL device element was obtained.

Then, an organic EL device element with an inorganic film is obtained by depositing an inorganic film (SiN) (500 nm in thickness) on the organic EL device element with a capacitively coupled plasma (CCP: Capacitively Coupled Plasma). In a glove box, the above-mentioned resin composition layer of the sealing sheet and the organic EL device element with an inorganic film were connected to each other, and these were bonded by a thermal laminator (LamipackerDAiSY A4 (LPD2325) manufactured by FUJiPLA). An evaluation sample was obtained in which an organic EL element with an inorganic film was sealed with a sealing sheet.

The evaluation sample of the organic EL element with an inorganic film sealed with the sealing sheet of Comparative Example 3 with an epoxy resin composition layer was a sample that was heated at a temperature of 100 ° C. for 60 minutes after bonding to make the epoxy resin. The composition layer is hardened.

The light-emitting area of the evaluation sample other than the dark spot was calculated with a KEYENCE microscope, and this value was set as an initial value.

Next, the evaluation sample was stored in a small environmental tester (SH-222 manufactured by espec) at a temperature of 85 ° C. and a humidity of 85% RH for a specific period of time, and the luminous area of the evaluation sample was measured at each specific time.

The light-emitting area of the evaluation sample stored in the small-scale environmental tester was set to a time less than 95% of the area compared to the initial value, and was calculated as the light-emitting area reduction start time, and evaluated based on the following criteria. The lower the moisture content of the resin composition layer of the sealing sheet, the longer the light emission area reduction start time becomes. The results are shown in Tables 2 and 3 below. The examples and comparative examples in which the light emission area reduction start time was not measured are described as "-" in Tables 2 and 3 below. (Baseline for light emission area reduction start time) ○ (Good): Light emission area reduction start time is 1000 hours or more △ (OK): Light emission area reduction start time is 800 hours or more and less than 1000 hours × (Bad): Light emission area reduction Start time is less than 800 hours

As shown in Tables 2 and 3, the sealing sheet having the first and second films having a WVTR of 1 (g / m ² / 24hr) or less is left to stand for 7 days even under an environment of a temperature of 25 ° C. and a humidity of 50% RH. It is also possible to suppress water absorption (that is, increase in water content) of the resin composition layer, and the use of such a sealing sheet can increase the life of the organic EL device (light emission area reduction start time). [Industrial availability]

The sealing sheet of the present invention is used for sealing electronic parts such as organic EL elements.

This case is based on Japanese Patent Application No. 2017-065143, which has been filed in Japan, and this content is fully included in the description of this case.

Claims (21)

A sealing sheet is a sealing sheet having a first film, a resin composition layer, and a second film, characterized in that the resin composition layer exists between the first film and the second film, and the first film and the second film The water vapor permeability of the 2 films is 1 (g / m ² / 24hr) or less. For example, the sealing sheet of claim 1, wherein the water vapor transmission rate of the first film and the second film is 0.01 (g / m ² / 24hr) or more and 1 (g / m ² / 24hr) or less. For example, the sealing sheet of claim 1, wherein the water vapor transmission rate of the first film and the second film is 0.01 (g / m ² / 24hr) or more and 0.5 (g / m ² / 24hr) or less, respectively. For example, the sealing sheet according to claim 1, wherein the water vapor transmission rate of the first film and the second film is 0.01 (g / m ² / 24hr) or more and 0.2 (g / m ² / 24hr) or less, respectively. For example, the sealing sheet of claim 1, wherein the water vapor transmission rate of the first film and the second film is 0.05 (g / m ² / 24hr) or more and 0.2 (g / m ² / 24hr) or less, respectively. For example, the sealing sheet of claim 1, wherein the water vapor transmission rate of the first film is less than 0.01 (g / m ² / 24hr), and the water vapor transmission rate of the second film is 0.01 (g / m ² / 24hr) Above, 1 (g / m ² / 24hr) or less. The sealing sheet according to claim 6, wherein the water vapor transmission rate of the first film is 0.005 (g / m ² / 24hr) or less. The sealing sheet according to claim 6, wherein the water vapor transmission rate of the first film is 0.001 (g / m ² / 24hr) or less. The sealing sheet according to claim 6, wherein the water vapor transmission rate of the first film is 0.0005 (g / m ² / 24hr) or less. The sealing sheet according to any one of claims 6 to 9, wherein the water vapor transmission rate of the second film is 0.01 (g / m ² / 24hr) or more and 0.5 (g / m ² / 24hr) or less. The sealing sheet according to any one of claims 6 to 9, wherein the water vapor transmission rate of the second film is 0.01 (g / m ² / 24hr) or more and 0.2 (g / m ² / 24hr) or less. The sealing sheet according to any one of claims 6 to 9, wherein the water vapor transmission rate of the second film is 0.05 (g / m ² / 24hr) or more and 0.2 (g / m ² / 24hr) or less. For example, the sealing sheet of claim 1, wherein the water vapor transmission rate of the first film is 0.0005 (g / m ² / 24hr) or less, and the water vapor transmission rate of the second film is more than 0.0005 (g / m ² / 24hr) And less than 0.01 (g / m ² / 24hr). The sealing sheet according to any one of claims 1 to 13, wherein the first film and the second film are films having a base material and a barrier layer. The sealing sheet according to claim 14, wherein the base material is a plastic film. The sealing sheet according to claim 14 or 15, wherein the barrier layer includes an inorganic film. The sealing sheet according to any one of claims 1 to 16, wherein the resin composition layer contains an olefin-based resin and / or an epoxy resin. The sealing sheet according to any one of claims 1 to 17, wherein the resin composition layer contains semi-sintered hydrotalcite. The sealing sheet according to any one of claims 1 to 18, wherein the first film is a film having a release layer. The sealing sheet according to any one of claims 1 to 19, wherein the first film and the second film are films having a release layer. The sealing sheet according to any one of claims 1 to 20, wherein the sealing sheet is for sealing an organic EL element.