JP2003249349A - Electroluminescent element and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an EL element having high moistureproof to show stable moistureproof against the change of environmental temperature of humidity, and sealed with a moistureproof film reducible in thickness and weight, and to provide its manufacturing method. <P>SOLUTION: This electroluminescent element is composed by sealing an electroluminescent element body with a moistureproof body of the moistureproof film. The moistureproof film is composed of a transparent multi-layer film having a layer structure wherein thin metal or nonmetal oxide films are respectively arranged directly or through an adhesive layer on both sides of a hygroscopic resin layer, and having a water vapor transmission rate of 0.05 g/m<SP>2</SP>*24 hr or less and a quantity of water vapor transmission of 0.15 g/m<SP>2</SP>or less. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroluminescent element sealed with a moisture-proof film having a high degree of moisture-proof property and a method for manufacturing the same.

[0002]

2. Description of the Related Art The action of applying an electric field to a fluorescent compound solid (phosphor) to convert electric energy into fluorescence emission energy is called electroluminescence (EL). E
L can be classified into a thin film type and a dispersion type based on its basic element structure. The thin film type EL device includes a light emitting layer made of a thin film of a phosphor. The dispersion type EL device has a light emitting layer in which a powder phosphor is dispersed in an organic or inorganic binder. The EL element includes an element body in which a light emitting layer is sandwiched between a pair of electrodes directly or via an insulating layer, and a transparent electrode is used for at least one of the pair of electrodes. EL elements are classified into a DC drive type (DC type) and an AC drive type (AC type) depending on whether the drive voltage is DC or AC.

Taking advantage of the features of thin film and light weight, EL elements are, for example, backlights for liquid crystal display elements, night lights, road signs, night advertisements, surface emitting light sources such as decorations, computer or word processor terminal displays, and televisions. Applications are expanding as flat displays such as image displays.

When the fluorescent substance forming the light emitting layer absorbs moisture,
The emission brightness is significantly impaired. Therefore, an EL element generally has a structure in which an EL element body having a light emitting layer disposed between a pair of electrodes is sealed with a transparent moistureproof body.
Hitherto, as a moisture-proof body of an EL element, a moisture-proof film mainly composed of a polychlorinated trifluoroethylene (PCTFE) film or a glass substrate has been used. Among these, the glass substrate has a limitation in thinning and weight reduction, and has a problem of lacking flexibility.

On the other hand, since PCTFE is a fluororesin, the cost is high, and the moisture resistance of the PCTFE film is remarkably lowered when the ambient temperature exceeds 50 ° C., so that the life of the EL element at high temperatures is extremely high. There was a problem that it became short. In addition, in the future, it is expected that it will be difficult to obtain fluororesin raw materials,
Other resin materials to replace PCTFE have been sought.

Conventionally, as such other resin materials, polyvinylidene chloride, polyvinyl alcohol and the like have been studied, and further, a resin film provided with a vapor deposition film of silicon oxide has also been studied. However, none of the materials has been put into practical use because the moisture resistance is not sufficient and the life of the EL element cannot be extended as compared with the case of using the PCTFE film.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to have a high degree of moisture-proofing performance comparable to or exceeding that of a conventional moisture-proofing film mainly composed of a polychlorinated trifluoroethylene film, and to have an ambient temperature and An object of the present invention is to provide an EL element which exhibits stable moisture-proof performance against changes in humidity, and which is sealed with a moisture-proof film that can be made thin and lightweight, and a method for manufacturing the same.

[0008] The inventors of the present invention, in the course of intensive research to overcome the above-mentioned problems of the prior art, formed a vapor-deposited film of a metal or non-metal oxide represented by a silicon oxide thin film. Alcohol film (hereinafter PV
Attention was focused on A film). The PVA film formed with such a vapor deposition film (hereinafter abbreviated as vapor deposition PVA film) is transparent and has a very low water vapor transmission rate which is a measure of water vapor barrier property. However, the vapor-deposited PVA film is not effectively used as a moisture-proof film for a package of an EL device, unlike the PCTFE film, because it is inferior in practical moisture-proof performance.

In fact, we have used a multilayer film containing a vapor-deposited PVA film as a moisture barrier film, and
When the L element was sealed, it was found that the emission brightness of the EL element was significantly reduced when exposed to high humidity conditions. The reason why only a moisture-proof film having poor practical performance can be obtained although the moisture permeability of the multilayer film itself containing the vapor-deposited PVA film is extremely small, was further investigated. As a result, the vapor-deposited PVA film or the multilayer film containing the vapor-deposited PVA film cannot absorb moisture of PVA, which is a hygroscopic resin, under normal manufacturing conditions, and the PVA film contains a certain amount of water. Was estimated to have an adverse effect on practical performance.

A multilayer film having a structure in which a silicon oxide thin film is arranged on both sides of a PVA film directly or via an adhesive layer is used, and the PVA film or vapor-deposited PVA film or multilayer film used is substantially After being thoroughly dried until it became absolutely dry, surprisingly, in terms of practical performance, a new moisture-proof film having a high moisture-proof performance comparable to or exceeding that of a PCTFE film-based moisture-proof film. I found what I could get.

The inventors of the present invention cannot simply evaluate the moisture-proof performance of the vapor-deposited PVA film or the multilayer film containing the vapor-deposited PVA film by the moisture vapor transmission rate, and take the moisture vapor transmission rate (measurement method described later) into consideration. And found what to evaluate. In fact, a multi-layer film having a structure in which a silicon oxide thin film is arranged on both sides of a PVA film directly or via an adhesive layer was prepared under normal production conditions.
The moisture permeability of the EL elements produced by using the thoroughly dried products as the moisture-proof film according to the production method of the present invention was measured, and it was found that there was a very large difference in the moisture permeability between them. did.

When the multilayer film produced under normal production conditions is used, the exposure rate of the EL device when exposed to a high humidity environment is significantly reduced, and in severe cases, the emission brightness is reduced. It can be lost. On the other hand, when the moisture-proof film of the present invention composed of a multilayer film that has been thoroughly dried is used, it exhibits a high emission luminance retention rate for a long period of time even when exposed to a high humidity environment. An EL element can be obtained.

The reason or mechanism by which the moisture-proof film used in the present invention exhibits such a high degree of moisture-proof performance is not entirely clear at this stage, but the present inventors consider the following. There is. Since the conventional vapor-deposited PVA film absorbs moisture under normal manufacturing conditions, it contains a certain amount of water. This is called the initial water absorption. The moisture vapor transmission rate of the vapor-deposited PVA film or the multilayer film containing the vapor-deposited PVA film is not significantly affected by this initial water absorption amount, but the moisture vapor transmission amount is greatly affected. If this moisture permeability is large, only a moisture-proof film having a practically poor moisture-proof performance can be obtained. On the other hand, when the vapor-deposited PVA film or the multilayer film containing the vapor-deposited PVA film is thoroughly dried, the initial water absorption amount is lowered, and the moisture permeation resistance of the PVA film itself is remarkably improved due to the aging effect and the like. It is presumed that, as will be described later, the vapor-deposited film and the adhesive layer also contribute to the improvement of the moisture permeation resistance. The remarkable improvement effect of the moisture-proof performance by such a drying treatment is remarkable, which cannot be expected by the conventional techniques.

A multi-layer film having a structure in which a metal or non-metal oxide thin film is arranged on both sides of a PVA film directly or via an adhesive layer shows an excellent small water vapor transmission rate. It is not possible to easily obtain the desired dry state of the PVA film (representative hygroscopic resin layer), which is present between the PVA film and the multi-layer film, due to the hindered water vapor barrier performance. However, once a desirable dry state is obtained by performing a thorough drying treatment for 10 hours or more at high temperature, and in some cases for 100 hours or more, combined with its small moisture permeability, it stabilizes an excellent small moisture permeability. It is possible to obtain a moisture-proof film that can be retained.

The moisture-proof film used in the present invention does not adversely affect the moisture-proof performance even when the environmental temperature or humidity changes. Further, flexibility can be imparted by appropriately selecting the layer structure. The present invention has been completed based on these findings.

[0016]

According to the present invention, an electroluminescence device is formed by sealing a main body of an electroluminescence device in which a light emitting layer is arranged between a pair of electrodes with a moisture-proof body having a moisture-proof film at least in part. In the sense element, the moisture-proof film contains a layer structure in which a metal or non-metal oxide thin film (C) is arranged on both surfaces of a hygroscopic resin layer (A) directly or via an adhesive layer (B). Consisting of a transparent multilayer film, (1) Water vapor permeability measured at a temperature of 60 ° C and relative humidity of 90% is 0.05g / m ² · 24hr or less, and (2) temperature is 40 ° C and relative humidity is 100%. Done 5
There is provided an electroluminescent element, which is a moisture-proof film having a moisture permeability of 0.15 g / m ² or less for 0 hours.

Further, according to the present invention, a method of manufacturing an electroluminescent element, in which the main body of the electroluminescent element in which a light emitting layer is disposed between a pair of electrodes is sealed with a moistureproof body, at least a part of which is a moistureproof film. At
As the moisture-proof film, a transparent multilayer film containing a layer structure in which a metal or non-metal oxide thin film (C) is arranged on both surfaces of a hygroscopic resin layer (A) directly or via an adhesive layer (B). And (1) temperature 60 ° C, relative humidity 90
% Is less than 0.05 g / m ² · 24 hr, and (2) the moisture permeability for 50 hours measured at 40 ° C and 100% relative humidity is less than 0.15 g / m ^2. As described above, there is provided a method for producing an electroluminescent element, which comprises the step of drying the multilayer film or the hygroscopic resin layer (A) constituting the multilayer film.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows an EL device to which the present invention is applied.
It is a cross-sectional schematic diagram which shows an example of an element. The EL element shown in FIG. 1 includes a substrate 3 provided with an electrode 2 and a substrate 5 provided with an electrode 4.
Thus, the EL element body formed by sandwiching the light emitting layer 1 is sealed between the pair of moistureproof bodies 6 and 7. Lead electrodes are respectively connected to the pair of electrodes 2 and 4,
An electric field is applied to the light emitting layer 1 by power feeding from an external power source.

The light emitting layer 1 may be of a dispersion type in which a powder fluorescent substance is dispersed in an organic or inorganic binder, or of a thin film type composed of a thin film of the fluorescent substance. The phosphor may be an inorganic phosphor or an organic phosphor. In addition, the light-emitting layer is disclosed in JP-A-7-1.
It may be a hybrid type light emitting layer in which a phosphor as disclosed in Japanese Patent No. 358080 is dispersed in an organic-inorganic composite matrix. The substrates 3 and 5 are made of, for example, a plastic film, a glass plate, a metal plate or the like, and at least one of them is made transparent so that the light from the light emitting layer is transmitted to the outside. In the present specification, “transparent” means transparent to the extent that light from the light emitting layer can be transmitted.

The electrodes 2 and 4 provided on each substrate are made of a metal or a metal oxide such as ITO (indium-tin complex oxide), and at least one of them is made transparent so that the light from the light emitting layer is exposed to the outside. To be transparent. Therefore, one of the substrate-electrode composites may be opaque, in which case one of the substrate-electrode composites (e.g., the composite of substrate 5 and electrode 4) may be a single metal plate such as an aluminum foil. It may be configured to serve as a substrate and an electrode.

The EL element body composed of the light emitting layer 1, the substrates 3 and 5, and the electrodes 2 and 4 is not limited to one, and a plurality of EL element bodies may be arranged in a plane or vertically stacked.
A plurality of the EL element bodies are assembled together to form a pair of moistureproof bodies 6
It is also possible to seal between 7 and 7.

At least one of the pair of moistureproof bodies 6 and 7 is composed of the moistureproof film of the present invention, but the other may be a glass substrate or a metal plate, if necessary.
Then, for example, when one moistureproof body 7 is a glass substrate, the substrate 5 thereon may be omitted and the electrode 4 may be provided directly on the glass substrate. Further, when the pair of moisture-proof bodies 6 and 7 are both the moisture-proof film of the present invention, they may be folded bodies of one sheet of moisture-proof film. Thus, a part of the moistureproof body may be a glass substrate or a metal plate. Therefore, the EL element of the present invention includes an EL element obtained by sealing the EL element body with a moisture-proof body, at least a part of which is a moisture-proof film.

FIG. 2 is a schematic sectional view showing another example of the EL element targeted by the present invention. The EL element shown in FIG. 2 has a transparent conductive film (ITO) 23 and a back electrode (Al).
It has a structure in which a light emitting layer 24 made of a powdered phosphor hardened with an organic binder and a dielectric layer 25 for preventing dielectric breakdown are sandwiched on one side thereof between a foil 26). Furthermore, FIG.
In the EL element, the moisture absorbing films 22 and 27 for dehumidification are inserted and sealed with the moisture proof films 21 and 28 so as to have flexibility.

In the present invention, a layer structure in which a metal or non-metal oxide thin film (C) is arranged on both surfaces of a hygroscopic resin layer (A) directly or through an adhesive layer (B) as a moisture-proof film. A transparent multi-layer film containing a material having a specific moisture permeability and moisture permeability is used.

The oxide thin film (C) may be formed on one side or both sides of the hygroscopic resin layer (A), but other transparent resin layers
It may be formed on (D). However, oxide thin film
(C), an adhesive layer (B) is disposed on the surface opposite to the surface on which it is formed by vapor deposition, whereby it is adhered to other layers and an oxide thin film ( It protects C) and prevents the occurrence of cracks, and also plays a role in further improving the moisture-proof performance.

The moisture-proof film used in the present invention typically has a basic layer structure as shown in FIGS. 3 to 8, and if necessary, the same type or different types may be added. Additional layers can be laminated. In Figure 3,
Oxide thin films (C) 32 and 3 on both sides of the hygroscopic resin layer (A) 33
4 is used, and the transparent resin layers (D) 31 and 35 are formed on both sides of the composite film X via the adhesive layer a.
The layer structure of the structure in which is laminated is shown.

In FIG. 4, a transparent resin layer (D) 41 is formed on one surface of a composite film X having an oxide thin film (C) 42 formed on one surface of a hygroscopic resin layer (A) 43 with an adhesive layer a interposed therebetween. Stack the
On the other side, one side of the transparent resin layer (D) 45 has an oxide thin film (C) 4
4 shows a layer structure of a structure in which the composite film Y forming No. 4 is laminated via the adhesive a. In FIG. 5, the transparent resin layer
A composite film X having an oxide thin film (C) 52 formed on one side of (D) 51 and an oxide thin film (C) 5 on one side of a transparent resin layer (D) 55.
4 and the composite film Y formed with the adhesive film a
A layer structure of a structure in which the hygroscopic resin layer (A) 53 is laminated on both surfaces of the hygroscopic resin layer (A) 53 is shown.

In FIG. 6, a composite film X having an oxide thin film (C) 62 formed on one surface of a transparent resin layer (D) 61, and an oxide thin film (C) 65 on one surface of a transparent resin layer (D) 66. And a composite film Z having the structure described above are laminated on both surfaces of a composite film Y having an oxide thin film (C) 63 formed on one surface of a hygroscopic resin layer (A) 64 with an adhesive layer a interposed therebetween. The configuration is shown.

In FIG. 7, a composite film X in which an oxide thin film (C) 72 is formed on one surface of a transparent resin layer (D) 71, a transparent resin layer (D) 76, and a hygroscopic resin layer (A) The layer structure of the structure in which the oxide thin films (C) 73 and 75 are formed on both surfaces of the composite film Y on both surfaces of the composite film Y via the adhesive layer a is shown.

In FIG. 8, a composite film X having an oxide thin film (C) 82 formed on one surface of a transparent resin layer (D) 81, and an oxide thin film (C) 86 on one surface of a transparent resin layer (D) 87. And the composite film Z formed with the composite film Z on which the oxide thin films (C) 83 and 85 are formed on both surfaces of the hygroscopic resin layer (A) 84 via the adhesive layers a, respectively. The layer structure of is shown.

Therefore, in the moisture-proof film used in the present invention, (i) the oxide thin film (C) is arranged on both surfaces of the hygroscopic resin layer (A) directly or via the adhesive layer (B), and further, (ii)
A layer structure in which a transparent resin layer (D) having a transparent resin layer (D) or an oxide thin film (C) formed on each oxide thin film (C) directly or via an adhesive layer (B) is arranged. The multilayer film to be contained is preferable, and typical examples of the basic structure thereof include the following layer structures.

(1) Transparent resin layer (D1) / adhesive layer (B1) / oxide thin film (C1) / hygroscopic resin layer (A) / oxide thin film (C2) / adhesive layer (B
2) / Transparent resin layer (D2), (2) Transparent resin layer (D1) / Adhesive layer (B1)
/ Oxide thin film (C1) / hygroscopic resin layer (A) / adhesive layer (B2) / oxide thin film (C2) / transparent resin layer (D2), (3) transparent resin layer (D1) / oxide thin film (C1) / adhesive layer (B1) / hygroscopic resin layer (A) / adhesive layer (B
2) / Oxide thin film (C2) / Transparent resin layer (D2), (4) Transparent resin layer
(D1) / oxide thin film (C1) / adhesive layer (B1) / oxide thin film (C2) / hygroscopic resin layer (A) / adhesive layer (B2) / oxide thin film (C3) / transparent resin layer (D2), (5) Transparent resin layer (D1) / oxide thin film (C1) / adhesive layer
(B1) / oxide thin film (C2) / hygroscopic resin layer (A) / oxide thin film (C3)
/ Adhesive layer (B2) / Transparent resin layer (D2), and (6) Transparent resin layer (D
1) / oxide thin film (C1) / adhesive layer (B1) / oxide thin film (C2) / hygroscopic resin layer (A) / oxide thin film (C3) / adhesive layer (B2) / oxide thin film ( C4) / transparent resin layer (D2).

The multi-layer film of the present invention comprises a transparent resin layer (D) and an oxide thin film on at least one surface of the multi-layer film having the above-mentioned basic structure, either directly or through the adhesive layer (B).
At least one additional layer selected from the group consisting of the transparent resin layer (D) having (C) formed thereon may be further arranged.

The hygroscopic resin layer (A) is a hygroscopic resin obtained by mixing a hygroscopic or non-hygroscopic resin with a hygroscopic compound such as calcium chloride, even if the hygroscopic resin itself is used. You may comprise by the resin composition of. Examples of the hygroscopic resin include polyvinyl alcohol (PVA) which is a saponified product of polyvinyl acetate (partial), saponified product of ethylene-vinyl acetate copolymer (EVOH), and polyamide. Of these, PVA is preferred. PVA having a saponification degree of usually 90% or more, preferably 95% or more, and more preferably 99% or more is desirable. When the PVA film is used, the more the drying treatment is performed, the more the initial water content can be reduced, and
The moisture permeability can be reduced, and as a result, a moisture-proof film having a practically high moisture-proof performance can be obtained,
Its moisture-proof performance is not impaired even by changes in environmental temperature and humidity.

Examples of the non-hygroscopic resin include polyolefin, polyester, polyvinyl chloride, vinylidene chloride copolymer and the like. Although the transparency of the hygroscopic resin layer (A) may be slightly impaired by the addition of a hygroscopic compound such as calcium chloride, the transparency sufficient to allow the emission of light from the light emitting layer can be maintained. The thickness of the hygroscopic resin layer (A) is usually 5 to 400 μm, preferably 10 to 200 μm.
Is. In the multilayer film of the present invention, a plurality of hygroscopic resin layers may be laminated via an adhesive layer, if necessary.
That is, one or more hygroscopic resin layers can be arranged as the transparent resin layer (D).

The oxide constituting the metal or non-metal oxide thin film (C) is not particularly limited as long as it provides a thin film having transparency and moderate flexibility. Examples of the metal oxide include Al, Zn, Sn, In and T
i, or oxides of two or more metals of any of these. As the non-metal inorganic oxide, SiO,
Silicon oxide such as SiO ₂ or a mixture thereof is typical, and can be used particularly preferably in the present invention. 10% by weight in the silicon oxide thin film
As long as the amount is a small amount, calcium, magnesium, or oxides thereof may be mixed as impurities.

The thickness of the oxide thin film (C) is usually 10 to 50.
It is 0 nm, preferably 20 to 200 nm. If this thickness is too thin, the moisture resistance will be insufficient, and if it is too thick,
The film is likely to be curled, and the oxide film itself is likely to be cracked or peeled.

The oxide thin film is usually formed on the hygroscopic resin layer (A) or the transparent resin layer (D) by the vapor deposition method, but on the surface opposite to the surface on which it is formed. An adhesive layer is provided. By providing the adhesive layer, the moistureproof performance is further enhanced. The adhesive constituting the adhesive layer may be any of a thermosetting adhesive, a thermoplastic adhesive, and an elastomer adhesive, but a thermosetting adhesive is preferably used. In either case, heat treatment is desirable. The heat treatment is preferably carried out at a high temperature for a long time unless the resin components constituting each layer including the adhesive are decomposed. The higher the heat treatment time, the shorter the heat treatment time, which is preferable from the viewpoint of productivity. It goes without saying that the heat treatment time depends on the layer structure.

In the multilayer film used in the present invention, additional layers such as a transparent resin layer (D) can be appropriately arranged. Therefore, the additional layers will be described below. For example, when an oxide thin film (C) is formed on both surfaces of one hygroscopic resin layer (A) as shown in FIG. 3, generally, the flexibility of a multilayer film containing such a composite film is lowered. Therefore, it may be difficult to use it particularly in a field requiring a high degree of flexibility. When a multilayer film containing such a composite film is used as a moisture-proof film,
During bending, cracks may occur particularly in the oxide thin film (C) located on the outer side, and the moisture-proof performance may be impaired. Therefore, in general, one film has an oxide thin film (C) formed only on one surface thereof by vapor deposition or the like, and two composite films having the oxide thin film (C) formed on one surface thereof are
It is preferable to bond them via an adhesive layer. That is, from the viewpoint of flexibility, it is preferable to adopt a configuration in which the hygroscopic resin layer (A) is sandwiched between the pair of oxide thin films (C) by the layer configuration shown in FIGS. 4 to 6.

However, in an application field in which flexibility is not so required, it is possible to use a multilayer film containing the layer structure shown in FIGS. 3, 7 and 8. Also in these cases, on both sides of the composite film in which the oxide thin film (C) is formed on both sides of the hygroscopic resin layer (A), another transparent resin layer (D) or oxide thin film (C) is formed on one side. The composite film
By bonding through the adhesive layer (B), oxide thin film
(C) can be protected. As the adhesive layer, for example, a layer made of an urethane-based, acrylic-based, polyester-based, or other adhesive having a thickness of about 1 to 50 μm is used.

A typical example of the additional layer is a transparent resin layer (D) or a transparent resin layer (composite film) having an oxide thin film (C) formed thereon. The resin forming the transparent resin layer may be a hygroscopic resin or a non-hygroscopic resin. As the transparent resin layer (D) made of a preferable non-hygroscopic resin, 8
Examples thereof include stretched or unstretched films of polyester type, polyolefin type, polyvinylidene chloride type, etc., which have high morphological stability at 0 ° C. or lower and high moisture resistance. In addition to these, examples of the resin material forming the transparent resin layer include heat resistant resins such as polyphenylene sulfide, polysulfone, polyarylate, and polyimide. An ultraviolet absorber or a pigment for color conversion of an EL element may be mixed with these resins.

As an additional layer, for example, PVA
And a poly (meth) acrylic acid or a partially neutralized product thereof, a heat-treated film (JP-A-6-2202).
No. 21), a gas barrier film such as a heat-treated film formed from a mixture of a saccharide and poly (meth) acrylic acid or a partially neutralized product thereof (JP-A No. 7-165942), and these gas barrier films. A composite film or the like formed on at least one surface of the thermoplastic resin layer can be used.

The oxide thin film (C) can be formed on a base film made of a hygroscopic resin or a non-hygroscopic resin by a vacuum vapor deposition method, an ion plating method, a sputtering method, a reactive vapor deposition method or the like. Among them, the reactive vapor deposition method is a method in which a metal, a metal oxide, or a mixture thereof is used as a vapor deposition material and vapor deposition is performed while supplying an oxygen gas. Such a method can also be carried out with silicon, silicon oxide, or a mixture thereof.

Prior to the formation of the oxide thin film (C), an anchor coating agent can be used in order to increase the adhesive strength between the oxide thin film and the base film. Suitable anchor coat agents include isocyanate-based, polyethyleneimine-based and organic titanium-based adhesion promoters, and polyurethane and polyester-based adhesives. Furthermore, as the anchor coating agent, a polyethylene-based, polyester-based, or polyamide-based solventless adhesive may be used. Therefore, the present invention includes the case of using a composite film in which an oxide thin film is formed on the surface of a base film via these anchor coating agents.

As the transparent resin layer (D), a film of a hygroscopic resin or a non-hygroscopic resin is singly bonded without forming the oxide thin film (C) via an adhesive layer, or
It is also preferable to form the additional layer by heat fusion. This is because if only the composite film formed with the oxide thin film (C) is laminated, the bending resistance of the obtained multilayer film is lowered, so that the flexibility is increased or the strength of the outer surface is improved. Because it is effective. The thickness of each film (transparent resin layer) other than the hygroscopic resin layer (A) as described above is usually 5 to 400 μm, preferably 10 to 200 μm.

As a part of the additional layer, an oxide thin film (C) was formed on at least one surface of the hygroscopic resin layer or the non-hygroscopic resin layer in order to improve the water vapor barrier property of the entire multilayer film. One or more composite films can be laminated. In this case, the oxide thin films of each composite film may be laminated via an adhesive layer, or the oxide thin film surface and the surface of another transparent resin layer may be laminated.

A heat-sealable transparent resin layer can be additionally disposed as the innermost layer in the multilayer film of the present invention. For joining with the other moisture-proof body, it is also preferable to provide a hot-melt type sealant layer of, for example, a polyolefin-based or epoxy-based material having a thickness of 10 to 300 μm. Since such a sealant layer is transparent, it can be said that it is a kind of transparent resin layer. Such a hot-melt type sealant layer may be provided only at a portion surrounding one or both of the moisture-proof films at the stage of encapsulating the EL device body using the moisture-proof film of the present invention.

As an additional layer forming the outermost layer of the multilayer film, a transparent resin layer having heat resistance is preferable. By using the heat-resistant transparent resin layer as the outermost layer, not only the heat resistance of the EL element can be improved, but also the heat sealing property can be improved when heat sealing.
Such a heat-resistant transparent resin layer has a melting point or a Vicat softening point of 100 ° C. or higher, preferably 120 ° C. or higher,
More preferably, a thermoplastic resin film having a temperature of 150 ° C. or higher can be mentioned. More specifically, a stretched or unstretched polypropylene film, a stretched or unstretched polyethylene terephthalate film and the like can be mentioned.

The total thickness of the multilayer film including the above-mentioned additional inner layer and outer layer is not limited as long as the transparency is not impaired, but in many cases, it is 30 to 1
The thickness is 000 μm, preferably 50 to 500 μm.

The transparent multilayer film constituting the moisture-proof film used in the present invention has (1) a temperature of 60 ° C. and a relative humidity (R
H) One measure of the moisture permeability (water vapor barrier properties under conditions of 90%) 0.05g / m ² · 24hr or less, preferably 0.04g / m ² · 24hr, and more preferably 0.03 g / m ² · 24 hours or less, and
(2) Moisture permeability (scale of water vapor barrier property affected by initial water absorption of multilayer film) for 50 hours under conditions of 40 ° C. and 100% RH is 0.15 g / m ² or less, preferably 0.13 g / M ² or less, more preferably 0.10 g / m ²
It is as follows. Most preferably, the moisture vapor transmission rate is 0.05.
It can be g / m ² or less.

According to the results of the research conducted by the present inventors, in the case of a normal film, the moisture permeability and the moisture permeability are determined by the measuring method and the unit if the various conditions such as the measuring temperature and the time are the same. Shows a 1: 1 correspondence although they are different. However, in a multilayer film containing a hygroscopic resin layer (A) adjacent to a low moisture permeability layer such as an oxide thin film (C) on both sides, before the low moisture permeability layer is formed, Under the manufacturing conditions, the hygroscopic resin layer (A) contains moisture to some extent due to moisture absorption. The amount of water due to this moisture absorption (initial amount of water absorption) does not have an essential effect on the moisture permeability, but it increases the moisture permeability and affects the practical moisture-proof performance as a package film for EL devices. There was found. That is, when the initial moisture absorption amount of the hygroscopic resin layer (A) is large, the moisture permeability tends to increase under the influence thereof.

The moisture vapor transmission rate defining the multilayer film (moisture-proof film) of the present invention is based on the filter paper enclosing method described later, and the moisture vapor transmission rate is measured by a water vapor transmission tester (PERMATRAN-W3 / 31SW) manufactured by Modern Control Co. Use A
It is the cumulative moisture permeation amount obtained by STM F1249 (corresponding to JIS K7129B method). The difference between the method of measuring the moisture vapor transmission rate and the method of measuring the moisture vapor transmission rate is that the conditions suitable for the harsh test corresponding to the long-term luminance test of EL elements, that is, 60 ° C., 9
While it was necessary to find a measurement method capable of measuring the water vapor transmission rate under the condition that the EL element was left in an atmosphere of 0% RH for 750 hours, the water vapor transmission rate and the water vapor transmission rate were simultaneously measured under such a condition. This is because there is no device that can be measured.

In the present invention, the moisture permeability is measured by the following method. ASTM F1249 (JIS K7129
The amount of moisture permeation is measured by PERMATRAN-W3 / 31SW, which is a water vapor permeation tester manufactured by Modern Control Co., Ltd. according to (Method B). Specifically, a flat multilayer film (test piece) to be measured is fixed to a diffusion cell, and the diffusion cell is separated by a test piece into a drying chamber and a humidity control chamber. Since the entire diffusion cell is placed at 40 ° C., the temperature of the test piece also becomes 40 ° C. over time. Before being separated by the test strips, the drying chamber was exposed to a stream of dry nitrogen, while one humidity chamber was under a stream of nitrogen while being exposed to 100% RH using a sponge containing distilled water. . When not separated by the test strips, both chambers have a mixture of dry nitrogen flow and 100% RH. Even after the two chambers were separated by the test piece, both the drying room and the humidity control room did not reach the original humidity of 0% RH and 100% RH, but they were separated by the test piece for a while. After about 1 hour, the original humidity is reached, so the measurement of the moisture permeability is started from this point. The water vapor that permeates the drying chamber through the test piece mixes in the stream of dry nitrogen and is carried to the infrared sensor. Using this infrared sensor, the ratio of infrared energy absorbed by water vapor is measured and taken out as an electric signal, and thereby the water vapor permeability is calculated. The water vapor permeability is usually measured every hour. The integrated value of this water vapor permeability over 50 hours (cumulative amount of water vapor transmission) is taken as the moisture permeability. In this measuring method,
Although the moisture permeability is measured under the conditions of 100% RH, it is generally required to measure under the conditions of 40 ° C. and 90% RH, so that the moisture permeability obtained by the above method is 0.
By multiplying by 9, the moisture permeation amount under the conditions of 40 ° C. and 90% RH can be obtained. Although it is difficult to directly measure the water content of PVA in a dried multilayer film,
By measuring the amount of moisture permeation, it can be used as a standard for its moisture-proof performance.

In the present invention, the moisture permeability is measured by the filter paper encapsulation method. Specifically, a filter paper as an EL element substitute is put between two pieces of the multilayer film and sealed. The sealing is performed in the same manner as the EL element body is sealed. That is, the surfaces to be sealed with the hot melt type sealant are placed inside and face each other, or the heat sealable resin sealant layers are placed inside and face each other. As an EL element substitute, a 100 mm x 100 mm Whatman (W
hatman) filter paper No. Three pieces of 2 are dried at 150 ° C. for 2 hours and then stacked. The heat sealing is performed with a width of 15 mm (seal width) with respect to the four sides of the multilayer film by passing between two heated rubber rolls at a sealable temperature. Five filter paper-enclosed samples obtained as described above are left in an atmosphere of 60 ° C. and 90% RH for 750 hours each. The weight increase obtained by this method is indicated as W ₀ . W ₀ is the total amount of water that has permeated from the surface of the multilayer film and from the seal portion by the time of measurement.

A size of 1 is provided between the filter paper and the multilayer film.
Aluminum foil with a thickness of 50 mm, which is 00 mm x 100 mm and has substantially zero moisture permeability, is placed on each of the upper and lower sides of the filter paper.
The weight increase measured by the same method as described above except that the sheets were put one by _one is indicated as W ₁ . W _{1 is} also the total amount of water that has permeated from the surface of the multilayer film and from the seal portion by the time of measurement. There is no difference in the amount of water permeation from the seal portion between W ₀ and W ₁ . Further, W ₁ is a value measured by preventing moisture from permeating with the aluminum foil. Therefore, the difference (W ₀ −W ₁ ) between the two is the amount of water permeated from the film surface of the multilayer film. That is, this difference is due to the amount of water absorbed vertically by the 100 mm × 100 mm area of the film surface of the multilayer film and absorbed by the filter paper, in other words, in the thickness direction of the standardized area of the multilayer film. The amount of moisture permeation is determined as a measure of wettability. From this, the water vapor transmission rate per 24 hours (24 hours) is determined in accordance with a conventional method to obtain the water vapor transmission rate in the present invention.

The above-mentioned water vapor transmission rate is theoretically not affected by the initial water absorption of the multilayer film. But,
The moisture absorption measured as a whole is 60 ° C, 90% RH,
Since the measurement is performed under the severe condition of 750 hours, the initial amount of water absorption becomes negligible as compared with the amount of water that permeates the film during that time. Therefore, the water vapor permeability can be an important measure of the water vapor barrier property excluding the effect of the initial water absorption amount (initial moisture absorption amount).

In order to form a transparent multilayer film (moisture-proof film) satisfying the above requirements for moisture permeability and moisture permeability, it is necessary to pay attention to the drying conditions. That is, the hygroscopic resin layer
(A) moisture-proof film of the present invention having a low moisture permeability oxide thin film (C) adjacent to both sides of the (A), in the manufacturing process, according to the normal manufacturing conditions, hygroscopic resin layer (A) moisture absorption After manufacturing without particularly controlling the amount, the hygroscopic resin layer (A) gives a predetermined hygroscopic moisture content by drying for a short time through an oxide thin film (C) having a low moisture permeability to the moisture absorbing moisture content already present in the hygroscopic resin layer (A). It cannot be reduced to a level. Therefore, in the process of manufacturing the moisture-proof film, the hygroscopic resin layer (A)
Oxide thin film (C) on both sides, either directly or through the adhesive layer
Before arranging, the hygroscopic resin layer (A) is sufficiently dried in advance, or a moisture-proof film is formed using the hygroscopic resin layer (A) formed in an absolutely dry state or a state close to it. Is efficient. However, once the multilayer film containing the hygroscopic resin layer (A) sandwiched between the oxide thin films (C) is formed, a long drying step is required. Such drying time depends on the amount of moisture that has already been absorbed, the type of laminated resin, especially the hygroscopic capacity of the hygroscopic resin, the degree of barrier of the gas barrier layer, the thickness of each layer, and the layer constitution (especially how many layers are laminated. However, the number of layers of the oxide thin film (C), etc., and the drying conditions.

The drying conditions are preferably a method of drying the multilayer film or the hygroscopic resin (A) constituting the multilayer film under atmospheric pressure or reduced pressure at a temperature of 35 to 150 ° C. for at least 10 hours. In particular, in the case of drying after producing the multilayer film, the temperature is 35 to 150 ° C., preferably 40 to 120 ° C., and 10 hours or more, preferably 30 hours or more, and more preferably 50 hours or more under normal pressure.
Particularly preferably, the drying is performed for 100 hours or more. Under reduced pressure,
Dry under a reduced pressure of 1 Torr or less at 35 to 150 ° C., preferably 40 to 70 ° C., for 10 hours or more, preferably 30 hours or more, more preferably 50 hours or more. When the drying temperature is low, it is preferable to dry as long as possible, for example, 100 hours or more, and in some cases 150 hours or more. Furthermore, a method of combining drying under normal pressure and drying under reduced pressure is also preferable. Thus, by thoroughly drying, the multilayer film, especially the hygroscopic resin layer
(A) is dried to a substantially dry state. Thereby, especially when the hygroscopic resin layer is a PVA film, it is possible to achieve a remarkable moisture-proof property which has not been known hitherto. This moisture-proof performance can be quantified by measuring the above-mentioned moisture permeability.

The EL element of the present invention is obtained by sealing the EL element body with the moisture-proof film composed of the multilayer film obtained as described above. In order to seal the EL element body with the moisture-proof film, either one of means for giving the moisture-proof film itself sealing performance, means for using another sealing body, or a combination thereof is used.

Specifically, (1) with or without a hot-melt type sealant layer on one surface of the moisture-proof film, two moisture-proof films or one moisture-proof film and the other moisture-proof body. An EL device body is placed between a glass substrate (or a metal plate, etc.) and the periphery thereof is sealed with a hot-melt type sealant. (2) One surface of the moisture-proof film has heat sealability like polyethylene. A method is used in which a transparent resin layer is provided as a sealant layer, the EL element body is placed between two moisture-proof films, and the periphery thereof is sealed by thermocompression bonding. An epoxy resin is a typical example of the hot-melt sealant.

[0061]

EXAMPLES Hereinafter, according to Examples, Comparative Examples, and Reference Examples,
The present invention will be described more specifically. The methods for measuring physical properties are as follows. (1) Moisture permeability: As described above. (2) Water vapor transmission rate: As described above.

(3) Luminance of luminescent brightness of EL element: EL element
Release the child sample for 500 hours under the condition of 90% relative humidity.
After placing, at room temperature, operating voltage 100V, operating frequency 40
Connected to a power source of 0Hz, initial emission brightness L ₀ Measure the next
Light emission after 750 hours at room temperature with voltage applied.
Degree L₁Is measured, and the luminescence brightness retention rate is calculated by the following formula.
It was Luminance retention rate = (L₁/ L₀) × 100 (%)

[Reference Example 1] A biaxially stretched polyethylene terephthalate film [vapor-deposited PET film; thickness 12 μm; "Tech Barrier T" manufactured by Mitsubishi Kagaku Paksu Co., Ltd.] on which a silicon oxide thin film was vapor-deposited was dried ( Heat treatment)
The water vapor permeability was measured without using. The results are shown in Table 1.

Reference Example 2 The same vapor-deposited PET film used in Reference Example 1 was heat-treated at 100 ° C. for 100 hours, and then the moisture permeability was measured. The results are shown in Table 1.

[Reference Example 3] A polyurethane adhesive [thickness: 3.5 µm; manufactured by Toyo Morton Co., Ltd., "AD-502 /", on the silicon oxide thin film surface of the same vapor-deposited PET film used in Reference Example 1 CAT-10 "], and further,
A biaxially stretched polyethylene terephthalate film [PET film; thickness 16 μm; “EMBLET-S” manufactured by Unitika Ltd.] was laminated thereon to produce a multilayer film. The moisture permeability was measured using this multilayer film without heat treatment. The results are shown in Table 1.

Reference Example 4 The same multilayer film as used in Reference Example 3 was heat treated at 100 ° C. for 100 hours, and then the moisture permeability was measured. The results are shown in Table 1.

[0067]

[Table 1]

(Footnote) (1) PET / SiO: biaxially stretched polyethylene terephthalate film on which a silicon oxide thin film is deposited (2) AD: polyurethane adhesive layer (3) PET: biaxially stretched polyethylene terephthalate film

As is clear from the results shown in Table 1, the moisture permeability is improved by heat treatment (drying for a long time), and in particular, when a multilayer film having an adhesive layer on a silicon oxide thin film is heat treated, the moisture permeability is significantly improved. To be done. However, since the base material film is not a hygroscopic resin layer but a PET film and the silicon oxide thin film and the adhesive layer are not provided on both sides, the level of moisture permeability itself is not sufficient.

Example 1 An EL device having the structure shown in FIG. 9 was produced as follows. <Production of EL Element Body> Cyanoethyl polyvinyl alcohol, barium titanate powder, and N, N'-dimethylformamide were uniformly mixed to prepare an insulating paste. Cyanoethyl polyvinyl alcohol, a powder fluorescent material in which Cu was added to ZnS as an activator, and N, N'-dimethylformamide were uniformly mixed to prepare a light emitting layer paste.

On the back electrode 97 (thickness 70 μm) made of aluminum foil, an insulating paste is screen-printed to form an insulating layer 96 (thickness 30 μm).
The light emitting layer paste is screen-printed to form a light emitting layer 95.
(Thickness 40 μm) was formed.

Polyethylene terephthalate film 93
A transparent conductive film (thickness 75 μm) on which a transparent vapor-deposited layer 94 of ITO (indium-tin composite oxide) is formed
m) was superposed on the light emitting layer 95 and thermocompression bonded by a roll laminator. An electrode lead wire was led out from the back electrode 97 and the ITO layer 94 on the transparent conductive film. Moisture-absorbing films (thickness 75 μm) 92 and 98 made of nylon with adhesive layers (thickness 30 μm) a made of ethylene-vinyl acetate copolymer on both sides of the EL device body thus produced, respectively. Was coated. Hereinafter, this was used as an EL device body.

<Production of Moisture-Proof Film> A moisture-proof film consisting of a multilayer film having the layer structure shown in FIG. 10 was produced. The layer structure of this multilayer film from the outer surface to the inner surface is as follows.

Unstretched polypropylene film 101 [thickness 50 μm; “RXC-18” manufactured by Tohcello Co., Ltd.], polyurethane adhesive layer a ₁ [thickness 3.5 μm; manufactured by Toyo Morton Co., Ltd. “AD-502 / CAT-10 "], a biaxially stretched polyethylene terephthalate film 102 having a transparent silicon oxide thin film 103 (thickness 127 nm) deposited thereon.
[Thickness 12 μm; “Tech Barrier T” manufactured by Mitsubishi Kagaku Heki Pax Co., Ltd.], polyurethane adhesive layer a ₂ [thickness 3.5 μm; same as above], transparent silicon oxide thin film 1
No. 04 (thickness 51 nm) was vapor-deposited on the biaxially stretched polyvinyl alcohol film 105 [thickness 12 μm; “Tech Barrier S” manufactured by Mitsubishi Kagaku Hito Pax Co., Ltd.], and a polyurethane adhesive layer a ₃ [thickness 3. 5 μm; same as above],
Biaxially stretched polyvinyl alcohol film 107 having a transparent silicon oxide thin film (thickness 51 nm) 106 deposited thereon.
[Thickness 12 μm; same as above], polyurethane adhesive layer a ₄ [thickness 3.5 μm; same as above], unstretched polypropylene film 108 [thickness 50 μm; same as above], polyurethane adhesive layer a ₅ [thickness 3.5 μm;
Same as above], unstretched polypropylene film 109
[Thickness 50 μm; same as above], polyolefin hot melt type sealant layer 110 [thickness 70 μm; EEA hot melt adhesive “A71” manufactured by Mitsui DuPont Co., Ltd.
0 ”].

The transparent multi-layer film having the above-mentioned layer structure was produced by a dry laminating method by laminating each layer at 65 ° C. with each urethane-based adhesive layer interposed therebetween. In FIG.
X, Y, and Z represent each vapor deposition film.

The multi-layer film thus produced was
It was vacuum dried at 45 ° C. for 150 hours under a reduced pressure of 1 Torr or less, and then stored in a closed can containing a silica gel desiccant. With respect to the moisture-proof film composed of the multilayer film obtained by the drying treatment as described above, the moisture permeability and the moisture permeability were measured. The results are shown in Table 2.

<Preparation of EL element> The two moisture-proof films prepared above were made to face each other on the surface of each polyolefin hot-melt type sealant layer 110, and in the meantime, E prepared above was prepared.
The L element body was placed, heated and pressure-bonded at 140 ° C., and the periphery was sealed to produce an electroluminescent EL element in which the EL element body was sealed with moisture-proof films 91 and 99. Using this EL device, the emission luminance retention rate was measured. The results are shown in Table 2.

[Comparative Example 1] A multilayer film having the same layer structure as in Example 1 was used in the same manner as in Example 1 except that the drying treatment was not performed, and the moisture permeability, the moisture permeability, and the emission brightness of the EL element were used. The retention rate was measured. The results are shown in Table 2.

Example 2 <Production of Moisture-Proof Film> A moisture-proof film composed of a multilayer film having the layer structure shown in FIG. 11 was produced. The layer structure of this multilayer film from the outer surface to the inner surface is as follows.

Biaxially stretched polyethylene terephthalate film layer 111 [thickness 16 μm; manufactured by Unitika Ltd. “EM
BLET-S ”], polyurethane-based adhesive layer a ₁ [thickness 3.5 μm; manufactured by Toyo Morton Co., Ltd.“ AD-502 / C
AT-10 "], a biaxially stretched polyethylene terephthalate film 112 [thickness 12 µm;" Tech Barrier H "manufactured by Mitsubishi Kagaku Pax Co., Ltd.] on which a transparent silicon oxide thin film 113 (thickness 45 nm) is deposited. Polyurethane adhesive layer a ₂ [thickness 3.5 μm; same as above], biaxially stretched polyvinyl alcohol film 114 [thickness 25 μm
m; "Boblon" manufactured by Nippon Synthetic Chemical Industry Co., Ltd.], polyurethane adhesive layer a ₃ [thickness 3.5 μm; same as above], transparent silicon oxide thin film 116 (thickness 45 nm).
Vapor-deposited biaxially stretched polyethylene terephthalate film 115 [thickness 12 μm; same as above], polyurethane adhesive layer a ₄ [thickness 3.5 μm; same as above], biaxially stretched polyvinyl alcohol film 117 (thickness 25
μm; same as above), polyurethane adhesive layer a ₅ [thickness 3.5 μm; same as above], and transparent silicon oxide thin film layer 118 (thickness 45 nm) vapor-deposited biaxially stretched polyethylene terephthalate film 119. (12 μm thick;
Same as above), polyurethane-based adhesive layer a ₆ [thickness 3.
5 μm; same as above], biaxially stretched polyethylene terephthalate film 120 (thickness 16 μm; same as above),
Polyolefin-based hot melt type sealant layer 121
[Thickness 50 μm; “Hirodyne 7589” manufactured by Hirodyne Industry Co., Ltd.].

Each of the layers except the polyurethane adhesive layer a ₆ , the biaxially stretched polyethylene terephthalate film 120, and the polyolefin hot melt type sealant layer 121 was subjected to a dry laminating method at 65 ° C. through each polyurethane adhesive layer. And laminated to produce a multilayer film, which was then dried at 100 ° C. for 100 hours under normal pressure.

Then, on the biaxially stretched polyethylene terephthalate film 119 surface of this multilayer film, the biaxially stretched polyethylene terephthalate film 120 was placed together with the polyolefin hot melt type sealant layer 121 through the polyurethane adhesive layer a ₆ and the 65 Dry lamination was performed at 0 ° C. to prepare a transparent multilayer film. This multilayer film was vacuum dried at 50 ° C. for 50 hours under a reduced pressure of 1 Torr or less. With respect to the moisture-proof film composed of the multilayer film obtained by the drying treatment as described above, the moisture permeability and the moisture permeability were measured. In addition, an EL device was prepared in the same manner as in Example 1 except that this moisture-proof film was used, and the emission luminance retention rate was measured. The results are shown in Table 2.

[Comparative Example 2] A multilayer film having the same layer structure as in Example 2 was used in the same manner as in Example 2 except that the drying treatment was not performed, and the moisture vapor transmission rate, the moisture vapor transmission rate, and the emission brightness of the EL element were used. The retention rate was measured. The results are shown in Table 2.

Comparative Example 3 A polychlorinated trifluoride ethylene film (thickness 200 μm) having a polyolefin hot melt type sealant layer (thickness 50 μm) on one surface was used instead of the moisture-proof film of Example 1. In the same manner as in Example 1, the water vapor transmission rate, the water vapor transmission rate, and the light emission luminance retention rate of the EL element were measured. The results are shown in Table 2.

[0085]

[Table 2]

(Footnote) (1) PCTFE / PO: Polychlorinated trifluoride ethylene film having polyolefin hot melt type sealant layer on one side (2) Moisture permeability at 90% RH: Moisture permeability at 100% RH It is a value obtained by multiplying the amount by 0.9.

[0087]

EFFECTS OF THE INVENTION According to the present invention, the water vapor transmission rate is equal to or lower than that of the conventional moisture-proof film mainly composed of polychlorinated trifluoroethylene film, and mainly composed of polychlorinated trifluorinated ethylene film. Provided is an EL element sealed with a moisture-proof film exhibiting moisture-proof performance equal to or higher than that of a conventional moisture-proof film. The moisture-proof film used in the present invention can exhibit stable moisture-proof performance against changes in environmental temperature and humidity.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of the layer structure of an EL element sealed with a moisture-proof film.

FIG. 2 is a schematic cross-sectional view showing another example of the layer structure of an EL element sealed with a moisture-proof film.

FIG. 3 is a schematic sectional view showing a specific example of the layer constitution contained in the moisture-proof film of the present invention.

FIG. 4 is a schematic cross-sectional view showing another specific example of the layer constitution contained in the moisture-proof film of the present invention.

FIG. 5 is a schematic sectional view showing another specific example of the layer constitution contained in the moisture-proof film of the present invention.

FIG. 6 is a schematic cross-sectional view showing another specific example of the layer constitution contained in the moisture-proof film of the present invention.

FIG. 7 is a schematic cross-sectional view showing another specific example of the layer constitution contained in the moisture-proof film of the present invention.

FIG. 8 is a schematic cross-sectional view showing another specific example of the layer constitution contained in the moisture-proof film of the present invention.

FIG. 9 is a schematic sectional view of an EL element used in an example of the present invention.

FIG. 10 is a schematic cross-sectional view of the moisture-proof film produced in Example 1 of the present invention.

FIG. 11 is a schematic cross-sectional view of the moisture-proof film produced in Example 2 of the present invention.

[Explanation of symbols]

1: light-emitting layer, 2, 4: electrode, 3, 5: substrate, 6, 7: moisture-proof body, 21, 28: moisture-proof film, 22, 27: moisture-absorbing film, 23: transparent conductive film, 24: light-emitting layer, 2
5: Dielectric layer, 26: Back electrode, 31, 35: Transparent resin layer, 32, 34: Oxide thin film, 33: Hygroscopic resin layer, 4
1, 45: transparent resin layer, 42, 44: oxide thin film, 4
3: Hygroscopic resin layer, 51, 55: Transparent resin layer, 52, 5
4: oxide thin film, 53: hygroscopic resin layer, 61, 66: transparent resin layer, 62, 63, 65: oxide thin film, 64: hygroscopic resin layer, 71, 76: transparent resin layer, 72, 73, 7
5: oxide thin film, 74: hygroscopic resin layer, 81, 87: transparent resin layer, 82, 83, 85, 86: oxide thin film, 8
4: Hygroscopic resin layer, 91, 99: Moisture-proof film, 92:
Moisture absorption film, 93: polyethylene terephthalate film, 94: ITO layer, 95: light emitting layer, 96: insulating layer,
97: back electrode, 98: moisture absorption film, 101, 10
8,109: unstretched polypropylene film, 102:
Biaxially oriented polyethylene terephthalate film, 10
3, 104, 106: Silicon oxide thin film, 105, 10
7: Biaxially stretched polyvinyl alcohol film, 110:
Polyolefin hot melt type sealant layer, 11
1,112,115,119,120: Biaxially stretched polyethylene terephthalate film, 113,116,11
8: Silicon oxide thin film, 114, 117: Biaxially stretched polyvinyl alcohol film, 121: Polyolefin-based hot melt type sealant layer, a: Adhesive layer, X,
Y, Z: Composite film.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hisaaki Terashima             18-13 Kamitama-ri, Tamazato-mura, Shinji-gun, Ibaraki Prefecture Kure             Haha Chemical Co., Ltd. Resin Processing Technology Center             Within (72) Inventor Satoru Matsunaga             18-13 Kamitama-ri, Tamazato-mura, Shinji-gun, Ibaraki Prefecture Kure             Haha Chemical Co., Ltd. Resin Processing Technology Center             Within (72) Inventor Masamichi Akatsu             18-13 Kamitama-ri, Tamazato-mura, Shinji-gun, Ibaraki Prefecture Kure             Haha Chemical Co., Ltd. Resin Processing Technology Center             Within F term (reference) 3K007 AB11 AB13 AB14 BA07 BB01                       CA06 DA02 DA04 FA02                 4F100 AA17B AA17D AA20 AK01C                       AK01E AK07 AK21 AK21A                       AK42 BA03 BA04 BA05 BA07                       BA08 CA23 CB00 DE01 EH66                       EJ38 JD04 JM02B JN01                       JN01C JN01E YY00

Claims (12)

[Claims] 1. An electroluminescent device comprising a main body of an electroluminescent device, in which a light emitting layer is disposed between a pair of electrodes, is sealed with a moisture-proof body, at least a part of which is a moisture-proof film. A transparent multilayer film containing a layer structure in which a metal or non-metal oxide thin film (C) is arranged on both surfaces of a conductive resin layer (A) directly or via an adhesive layer (B), (1) Moisture permeability measured at 60 ℃ and 90% relative humidity is 0.05g
/ M ² · 24 hr or less, and (2) the moisture permeability of 0.15 for 50 hours measured at a temperature of 40 ° C and a relative humidity of 100%.
An electroluminescent element, which is a moisture-proof film having a g / m ² or less. 2. A multilayer film comprising (i) a hygroscopic resin layer (A)
Oxide thin film (C) on both sides of either directly or through the adhesive layer (B)
Is further disposed, (ii) a transparent resin layer (D) or an oxide thin film (C) formed on each oxide thin film (C) directly or via an adhesive layer (B) ( The electroluminescent device according to claim 1, wherein D) contains a layered structure. 3. The multilayer film comprises (1) the transparent resin layer (D1) /
Adhesive layer (B1) / oxide thin film (C1) / hygroscopic resin layer (A) / oxide thin film (C2) / adhesive layer (B2) / transparent resin layer (D2), (2) transparent resin layer ( D1) / adhesive layer (B1) / oxide thin film (C1) / hygroscopic resin layer (A)
/ Adhesive layer (B2) / Oxide thin film (C2) / Transparent resin layer (D2), (3)
Transparent resin layer (D1) / oxide thin film (C1) / adhesive layer (B1) / hygroscopic resin layer (A) / adhesive layer (B2) / oxide thin film (C2) / transparent resin layer (D
2), (4) Transparent resin layer (D1) / oxide thin film (C1) / adhesive layer (B1)
/ Oxide thin film (C2) / Hygroscopic resin layer (A) / Adhesive layer (B2) / Oxide thin film (C3) / Transparent resin layer (D2), (5) Transparent resin layer (D1) / Oxide thin film (C1) / adhesive layer (B1) / oxide thin film (C2) / hygroscopic resin layer (A) / oxide thin film (C3) / adhesive layer (B2) / transparent resin layer (D2),
Or (6) Transparent resin layer (D1) / oxide thin film (C1) / adhesive layer (B
1) / oxide thin film (C2) / hygroscopic resin layer (A) / oxide thin film (C3) /
The electroluminescent device according to claim 2, which has a layer structure of adhesive layer (B2) / oxide thin film (C4) / transparent resin layer (D2). 4. A transparent resin layer (D) is provided on at least one surface of the multilayer film directly or through an adhesive layer (B).
The electroluminescent device according to claim 2, further comprising at least one additional layer selected from the group consisting of the transparent resin layer (D) having the oxide thin film (C) formed thereon. 5. A multi-layer film comprising a transparent resin layer (D) on at least one surface thereof, directly or through an adhesive layer (B).
The electroluminescent device according to claim 3, further comprising at least one additional layer selected from the group consisting of a transparent resin layer (D) having an oxide thin film (C) formed thereon. 6. The electroluminescent element according to claim 2, wherein the multilayer film has a heat-resistant transparent resin layer (D) as an outermost layer thereof. 7. The electroluminescent device according to claim 2, wherein the multilayer film is such that a heat-sealable transparent resin layer is additionally disposed on the innermost layer thereof. 8. The metal or non-metal oxide thin film (C) comprises:
The electroluminescent device according to claim 1, which is a silicon oxide thin film. 9. The electroluminescent device according to claim 1, wherein the hygroscopic resin layer (A) is a polyvinyl alcohol layer. 10. A method for producing an electroluminescent element, comprising: sealing a main body of an electroluminescent element, in which a light emitting layer is disposed between a pair of electrodes, with a moisture-proof body, at least a part of which is a moisture-proof film. , A transparent multilayer film containing a layer structure in which a metal or non-metal oxide thin film (C) is arranged on both surfaces of a hygroscopic resin layer (A) directly or through an adhesive layer (B), And,
(1) Water vapor permeability measured at a temperature of 60 ° C. and relative humidity of 90% is 0.05 g / m ² · 24 hr or less, and (2) moisture permeability of 50 hours measured at a temperature of 40 ° C. and relative humidity of 100%. Is 0.15 g / m ² or less, and a step of drying the multi-layer film or the hygroscopic resin layer (A) constituting the multi-layer film is provided. 11. The drying step, wherein the multilayer film or the hygroscopic resin layer (A) constituting the multilayer film is dried under atmospheric pressure or reduced pressure at a temperature of 35 to 150 ° C. for at least 10 hours. 10. The manufacturing method according to 10. 12. The method according to claim 10, wherein the hygroscopic resin layer (A) is a polyvinyl alcohol layer.