JPH0929884A - Laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated film which is most suitable for a protective film of EL elements, has high moistureproof property, and is excellent in view of economical point. SOLUTION: In a laminated film having an inorganic layer, a test piece of the laminated film is set to 90×110mm. At the center of its one face, a polytetrafluoroethylene having a thickness of 0.6mm and a size of 50×50mm is arranged. Further thereon, a polytetrafluoroethylene film having a thickness of 0.1mm and a size of 90×110mm is superposed in such a manner that its outline coincides with the outline of the test piece. When it is passed between rolls having a roll pressure of 6kgf/cm<2> and being heated to a temperature of 140 deg.C at a film feed speed of 1m/min, a rise of a steam permeating quantity of the laminated film is 2.5×10<-3> g/day or less before and after the treatment.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a laminated film having a high degree of moisture resistance. More specifically, it relates to a laminated film having excellent moisture resistance which is useful as a protective film for an electroluminescence (EL) element.

[0002]

2. Description of the Related Art An organic dispersion type EL device is a surface emitting device which has low power consumption and is inexpensive in addition to its features of being lightweight and thin.
However, in the organic dispersion-type EL element, since the phosphor material such as ZnS is dispersed in the organic binder to form the luminous body layer, the luminous body absorbs moisture in the atmosphere. When the luminescent substance comes into contact with moisture, the luminescent substance deteriorates and does not emit light.
Therefore, conventionally, a fluorine-based film excellent in moisture resistance and light transmittance, particularly polychlorinated trifluoroethylene (PCTFE)
The EL element is packaged by the laminated film mainly containing, and the light emitting material is protected from moisture. In recent years, instead of the fluorine-based film, a laminated film mainly composed of a film having an inorganic thin film layer on the surface of a plastic film and excellent in moisture resistance has been used. For example,
JP-A-60-159165 proposes a film obtained by coating a plastic film with MgO. JP-A-2-258251 proposes a film obtained by coating a polyvinyl alcohol film with silicon oxide. In addition, JP-A-3-203634
In the publication, it is proposed that the film is prevented from being deformed by hardening the film.

[0003]

However, since the laminated film mainly composed of the fluorine-based film is expensive, it has a drawback that the manufacturing cost of the EL element increases. In addition, the production and disposal of the fluorine-based film is considered to be a problem due to global environmental issues. On the other hand, a laminated film mainly composed of a plastic film having an inorganic thin film layer on its surface has a problem that the moisture resistance is deteriorated in the process of packaging an EL element. Usually EL
The device is packaged as described below. E
The moisture-proof laminated film for L is often provided with a sealant layer on one surface. A moisture-proof laminated film is placed on the EL element so that the light emitting surface of the EL element is aligned with the sealant surface. A moisture-proof substance such as metal or glass is placed on the non-light-emitting surface side of the EL element, or a moisture-proof laminated film is placed so that the sealant surface and the non-light-emitting surface of the moisture-proof laminated film meet. This is thermocompression bonded by passing it between heated rolls or by heat pressing.
At this time, the moisture-proof laminated film is bent along the EL element at the edge of the EL element or the like. By this bending, the inorganic thin film layer is destroyed, and the moisture resistance is remarkably lowered in the bent portion. As described above, in JP-A-3-203634,
In order to solve this, the rigidity of the film is increased, but this has a drawback that the EL element cannot be packaged well.

An object of the present invention is to provide a laminated film which has a high degree of moisture resistance and is economically excellent and which can be used as a protective film for EL devices.

[0005]

The above objects are attained by the following inventions. A laminated film including an inorganic layer, wherein a test piece of the laminated film is 90 mm × 110 mm, and a polytetrafluoroethylene having a thickness of 0.6 mm and 50 mm × 50 mm is placed at the center on one side of the test piece. A polytetrafluoroethylene film having a thickness of 0.1 mm and a size of 90 mm × 110 mm was overlaid on the test piece so that the outer shape of the test piece was the same, and the pressure was 6 kgf / cm ² at a roll pressure and 140 ° C.
The film feed rate is 1m / mi between the rolls
A laminated film, which has a water vapor transmission rate increase of 2.5 × 10 ⁻³ g / day or less before and after the treatment. A plastic film having an inorganic layer on at least one surface and a water vapor permeability of 6 g / m at a thickness of 100 μm or less.
A laminated film according to claim 1, which comprises an organic layer having a ratio of ² / day or less. The laminated film, wherein the inorganic layer comprises or comprises a metal oxide. The inorganic layer contains 20 to 99% by weight of aluminum oxide, and the specific gravity of the inorganic layer is represented by the formula: D = 0.01A + b (wherein D is the specific gravity of the inorganic layer, A is the aluminum oxide in the inorganic layer. %, And b is a number of 1.6 to 2.2).
A laminated film which satisfies or is described. The laminated film as described above, wherein the organic layer comprises polypropylene or polyvinylidene chloride.

The laminated film of the present invention comprises an inorganic layer, and the increase in the amount of water vapor permeation before and after the treatment shown below is 2.
It is characterized by being 5 × 10 ⁻³ g / day or less. The treatment means that the test piece of the laminated film is 90 mm × 11.
0 mm, on one side, but in the case where a sealant layer is provided on one side of the laminated film, a thickness of 0.6 mm, 50 mm x 50 mm polytetrafluoroethylene is placed at the center of the surface on the sealant layer side, Further thereon, a polytetrafluoroethylene film having a thickness of 0.1 mm and a size of 90 mm × 110 mm was laid on the test piece so that its outer shape was the same, and this was rolled at a pressure of 6 kgf / cm ² and a temperature of 140.
Film feed rate 1m / m between rolls heated to ℃
It is a process of passing in. That is, after performing the treatment, peel the laminated film from polytetrafluoroethylene to measure its water vapor permeability, to the value obtained by subtracting the water vapor permeability before the treatment from the water vapor permeability of the laminated film after this treatment,
The water vapor transmission rate calculated by multiplying the measurement area is
It is 2.5 × 10 ⁻³ g / day or less. If the increase in the amount of water vapor transmission before and after the treatment exceeds 2.5 × 10 ⁻³ g / day, the moisture proof property deteriorates, and when used as a protective film for an EL device, the light emitting layer of the EL device deteriorates significantly. . Preferably 1 × 10 ⁻³ g / day or less, more preferably 5 ×
It is 10 ⁻⁴ g / day or less.

In the present invention, the water vapor transmission rate is defined by JIS
PE based on K 7129 B method, manufactured by MOCON
40 ° C, 90% R using RMATRAN-W3 / 31
It is measured by H.

The laminated film of the present invention having the above characteristics may be a laminated film containing an inorganic layer, but is preferably a plastic film having an inorganic layer on at least one surface (hereinafter, also referred to as A layer). Water vapor permeability of 2.5 × 10 ^-4 g / m ² / day at a thickness of 1 μm or more
It can be obtained by forming a laminated film containing the following organic layer (hereinafter, also referred to as B layer).

Examples of the inorganic substance forming the inorganic layer used in the present invention include metal oxides (eg, Al ₂ O ₃ and SiO _2).
2 , MgO, CaO, ZrO, etc.) and the like. These may be used in combination of two or more, for example, Al ₂ O ₃ —Si
_{O 2, MgO-SiO 2,} Al 2 O 3 -MgO and the like. From the viewpoint of stability to water, flexibility, and water vapor barrier properties, SiO ₂ , Al ₂ O ₃
It is SiO ₂ .

The method for producing the inorganic layer is not particularly limited, and includes, for example, vacuum deposition method, sputtering method, ion plating method,
It is manufactured by the wet coating method.

The thickness of the inorganic layer is preferably 5 to 800 nm, more preferably 7 to 100 nm from the viewpoint of flexibility and water vapor barrier property.

Further, the inorganic layer may contain impurities (for example, carbon etc.) in an amount of, for example, about 3% or less as long as the characteristics (moisture-proof property, transparency) are not impaired.

Further, the inorganic layer preferably contains 20 to 99% by weight of aluminum oxide, and the specific gravity of the inorganic layer is represented by the formula: D = 0.01A + b (where D is the specific gravity of the inorganic layer, (A represents the weight% of aluminum oxide in the inorganic layer, and b represents a number of 1.6 to 2.2).
Is preferably satisfied. When the value of b is less than 1.6 and the above formula is satisfied, the structure of the inorganic layer becomes rough, and the water vapor barrier property of the laminated film tends to be insufficient. Further, when the value of b for satisfying the above formula is larger than 2.2, the initial water vapor barrier property after film formation is excellent, but the film becomes too hard and the mechanical property is inferior. The water vapor barrier property of the film tends to decrease. More preferably, b is 1.7 in the above formula.
The range is from 2.1 to 2.1.

In the present invention, the specific gravity means JIS K 0.
061 based on the density gradient tube method.

The specific gravity of the inorganic layer is appropriately adjusted depending on the manufacturing conditions of the inorganic layer.

Examples of the organic polymer forming the plastic film used in the present invention include polyethylene terephthalate (PET), polypropylene (PP), polyethylene, nylon 6, nylon 12, nylon 6
6, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyvinyl alcohol (PVA), polycarbonate, polystyrene and the like. Among them,
From the viewpoint of moisture resistance, PET, PP and PVA are preferable. The organic polymer may be used by copolymerizing these organic polymers with each other or by copolymerizing or blending the organic polymer with another organic substance (eg, acrylic).

The method for synthesizing the organic polymer is not particularly limited, and a method known per se is used.

Further, the organic polymer may be blended with known additives such as lubricants, plasticizers and antistatic agents.

The plastic film used in the present invention is produced, for example, by melt-extruding the above-mentioned organic polymer and stretching, cooling and heat-setting in the longitudinal direction and / or the width direction, if necessary.

The plastic film may be subjected to surface treatment such as corona treatment, flame treatment and anker coating.

The thickness of the plastic film is 3 to 50.
The thickness is preferably 0 μm, more preferably 10 to 100 μm. If the thickness is less than 3 μm, it tends to be deformed and the handling tends to be difficult, and if it exceeds 500 μm, the flexibility tends to decrease.

The layer A is formed by providing the above-mentioned inorganic layer on at least one surface of the above plastic film, and its manufacturing method is not particularly limited, and is manufactured by, for example, a vacuum vapor deposition method, a sputtering method, an ion plating method, a wet coating method. It

The organic layer (B layer) used in the present invention is 1
Water vapor permeability is 6 g / m ² / da at a thickness of 00 μm or less
It is y or less, preferably 3 g / m ² / day or less, and more preferably 1 g / m ² / day or less. When the water vapor permeability exceeds 6 g / m ² / day, the amount of increase in the amount of water vapor permeated after the treatment becomes large. The organic material forming the organic layer is not particularly limited as long as it satisfies the above characteristics, but examples thereof include plastics such as PP, PVDC, PVC, polyacrylonitrile, and the like. From the point, PP, PVD
C is preferred.

Here, the water vapor transmission amount of the organic layer is measured according to the above-mentioned method for measuring the water vapor transmission amount of the laminated film. However, when the organic layer is produced by coating it on another film, it can be measured as follows. First, after measuring the water vapor permeability of another film in advance, an organic material is coated to form an organic layer on the other film. This water vapor permeability is a value similarly measured and converted from the water vapor permeability of other films. That is, the reciprocal of the water vapor transmission rate of the coating film is equal to the sum of the reciprocal of the water vapor transmission rate of the organic layer and the reciprocal of the water vapor transmission rate of the other film, which can be converted.

The water vapor transmission amount of the organic layer is adjusted by the raw material organic material used for the organic layer, the thickness of the organic layer, and the like.

The method for producing the organic material for forming the organic layer is not particularly limited, and the organic material is produced by a method known per se.

The method for producing the organic layer used in the present invention is not particularly limited, and examples thereof include a method of forming a film according to the above-mentioned method of producing a plastic film, or a method of coating with another film.

The thickness of the organic layer is preferably 100 μm.
Or less, more preferably 20 μm or less. 100 μm
If it exceeds, the flexibility of the laminated film tends to decrease.

The laminated film of the present invention comprises the A layer and the organic layer (B layer). Each of the A layer and the B layer may be one layer or may be a plurality of layers. The order of laminating each layer is also not particularly limited, but the layers are laminated so that the inorganic layer contained in the B layer does not become the outermost layer. Moreover, layers other than the A layer and the B layer may be provided as long as the transparency of the laminated film is not impaired.

The method for producing the laminated film of the present invention is not particularly limited, and may be, for example, a method of laminating the A layer film and the B layer film with an adhesive (for example, a polyurethane adhesive), or on the A layer film. In addition, when formed into a film, the water vapor transmission amount is 2. with a thickness of 1 μm or more.
A method in which the B layer is provided on the A layer film by coating an organic substance having a concentration of 5 × 10 ⁻⁴ g / m ² / day or less may be used. In addition, an arbitrary plastic film is coated with an organic substance that has a water vapor transmission rate of 2.5 × 10 ⁻⁴ g / m ² / day or less at a thickness of 1 μm or more, and the film is adhered. It can also be manufactured by laminating it with the layer B with an agent.

The laminated film of the present invention may have a sealant layer. Examples of the sealant layer include thermoplastic resins such as ethylene-acrylic copolymer resin, low-density polyethylene, high-density polyethylene, ionomer resin, and adhesive polyester resin because they can be thermocompression bonded. Especially for EL, from the viewpoint of adhesiveness to metal, ethylene-ethyl acrylate copolymer resin (E
EA), ethylene-acrylic acid copolymer resin (EAA),
Ethylene-methacrylic acid copolymer resin (EMAA) is preferred.

The method for providing the sealant layer is not particularly limited, and examples thereof include an extrusion laminating method and a dry laminating method.

Further, the laminated film of the present invention preferably has a light transmittance of 70% or more, more preferably 80% or more.

In the present invention, the light transmittance means JIS.
Based on K7105, it measured using the NDH-1001DP haze meter (made by Nippon Denshoku Industries Co., Ltd.).

The light transmittance of the laminated film is adjusted depending on the types and thicknesses of the plastic film, the inorganic layer and the organic layer used.

[0036]

EXAMPLES The present invention will be described below with reference to examples. The method of measuring the characteristic value is shown below.

[Water vapor transmission amount] The water vapor transmission amount is determined by JIS.
Based on the K 7129 B method, manufactured by MOCON, P
Using ERMATRAN-W3 / 31, 40 ° C x 90%
It was measured by RH.

[Light transmittance] The light transmittance is measured according to JIS K.
It measured based on 7105 using the NDH-1001DP haze meter (made by Nippon Denshoku Industries Co., Ltd.).

[Specific gravity] The specific gravity was measured by the density gradient tube method based on JIS K 0061.

[Luminance] Luminance is a color difference meter CS-100.
(Minolta Camera Co., Ltd.).

Example 1 Si was formed on one surface of a PET film having a thickness of 12 μm by vapor deposition.
Ox (hereinafter, x is about 1.8) was coated to a thickness of 50 nm to obtain an A layer. Biaxially stretched PP with a thickness of 60 μm as layer B
(OPP) film (water vapor transmission rate: 2.1 g / m ² /
50 μm thick EAA film was used as the sealant layer. Each film was dry laminated with an adhesive to obtain a laminated film. The structure of the laminated film was OPP / SiOx coated PET / EAA, and the SiOx coated surface was on the OPP side.

Comparative Example 1 A laminated film was obtained in the same manner as in Example 1 except that a 60 μm-thick PET film (water vapor transmission rate: 9.2 g / m ² / day) was used instead of the OPP film. The structure of the laminated film is PET / SiOx coated PET / E
It is AA.

Example 2 Si was deposited on one surface of a PET film having a thickness of 12 μm by vapor deposition.
Ox was coated at 50 nm to obtain layer A. PVDC was coated on the SiOx side of the A layer to a thickness of 4 μm, and a PET film having a thickness of 100 μm was further laid on the PVDC layer to form a B layer on the A layer (water vapor permeation of the B layer). Amount: 3.5 g / m ² / day). Further, an EAA film having a thickness of 50 μm was used as the sealant layer. Each film was dry laminated with an adhesive to obtain a laminated film. The structure of the laminated film is PET / PV
DC / SiOx coated PET / EAA.

Comparative Example 2 A laminated film was obtained in the same manner as in Example 2 except that PVDC was not used (water vapor transmission rate of layer B: 5.5 g / m ^2).
/ Day). The constitution of the laminated film is PET / SiOx coated PET / EAA.

Example 3 An inorganic layer made of an aluminum oxide-silicon oxide composite oxide having a specific gravity of 2.6 (b = 2.2) containing 40% by weight of aluminum oxide was formed on one side of a PET film having a thickness of 12 μm. The layer A was obtained by forming a 20 nm coating by vapor deposition. A 60 μm thick OPP film (water vapor transmission rate: 2.1 g / m ² / day) was used as the B layer, and a 50 μm thick EAA film was used as the sealant layer. Each film was dry laminated with an adhesive to obtain a laminated film. The laminated film was composed of two A layers, and Al ₂ O ₃ —SiO ₂ coated PET / OP.
P / Al ₂ O ₃ —SiO ₂ coated PET / EAA, and Al ₂ O ₃ —SiO ₂ coated PET Al ₂ O ₃ −
The SiO ₂ coated surface was on the OPP side.

Comparative Example 3 A 60 μm thick PET film (water vapor transmission rate: 9.2 g / m ² / da) was used instead of the 60 μm thick OPP film.
A laminated film was obtained in the same manner as in Example 3 except that y) was used. The structure of the laminated film is Al ₂ O ₃ —SiO _2.
2 coated PET / PET / Al ₂ O ₃ —SiO ₂ coated PET / EAA.

Example 4 The layer A of Example 3 was used, and the layer B was made of PE having a thickness of 12 μm.
A film in which PVDC was coated on the T film to a thickness of 5 μm was used (water vapor transmission amount of layer B: 2.
8 g / m ² / day). Further, an EAA film having a thickness of 50 μm was used as the sealant layer. Each film was dry laminated with an adhesive to obtain a laminated film. The laminated film is composed of two layers A, PVDC coated P
ET / Al ₂ O ₃ -SiO ₂ coated PET / Al ₂ O ₃
Is a -SiO ₂ coat PET / EAA. Al ₂ O ₃ −
The SiO ₂ coated PET film is Al ₂ O ₃ —SiO ₂
The coated surfaces were bonded together. The PVDC coated surface of the PVDC coated PET film is Al ₂ O ₃ -SiO ₂ coated P
It was on the ET side.

Comparative Example 4 A PET film having a thickness of 12 μm (water vapor transmission rate: 46 g / m ² / da) was used instead of the PVDC-coated PET film.
A laminated film was obtained in the same manner as in Example 4 except that y) was used. The structure of the laminated film is PET / Al ₂ O ₃ −
SiO ₂ coated PET / Al ₂ O ₃ —SiO ₂ coated P
ET / EAA.

Example 5 Two types of films were used as the A layer. One uses the A layer obtained in Example 3, and the other uses 55 μm of aluminum oxide on one side of a nylon (Ny) film having a thickness of 12 μm.
An inorganic layer composed of an aluminum oxide-silicon oxide composite oxide having a specific gravity of 2.3 (b = 1.7) containing 20% by weight was formed by coating 20 nm by a vapor deposition method to obtain an A layer. As the B layer, an OPP film having a thickness of 60 μm (water vapor transmission rate: 2.1 g / m ² / day) was used. On the Ny film surface of the other A layer, EEA with a thickness of 50
A sealant layer was formed by extrusion lamination so as to have a thickness of μm. Each film was dry laminated with an adhesive to obtain a laminated film. The laminated film is composed of two layers A, OPP / Al ₂ O ₃ —SiO ₂ coated PET.
A / Al ₂ O ₃ -SiO ₂ coat Ny / EEA. A
l ₂ O ₃ -SiO ₂ coated PET film and Al ₂ O ₃
-SiO ₂ coat Ny film was adhesive coated faces.

Comparative Example 5 Instead of an OPP film having a thickness of 60 μm, a thickness of 150 μm
PET film (water vapor transmission rate: 3.7 g / m ² / d
A laminated film was obtained in the same manner as in Example 5 except that ay) was used. The structure of the laminated film is PET / Al ₂ O
_3- SiO ₂ coated PET / Al ₂ O ₃ —SiO ₂ coated Ny / EEA.

Example 6 Two kinds of films were used as the A layer. One uses the layer A obtained in Example 2, and the other uses 12 μm thick PVA.
It was obtained by coating one side of the film with SiOx to a thickness of 50 nm by a vapor deposition method. As the B layer, an OPP film having a thickness of 60 μm (water vapor transmission rate: 2.1 g / m ² / day) was used. On the other side of the PVA film surface of the A layer, EAA
Was extruded and laminated to have a thickness of 50 μm to form a sealant layer. Each film was dry laminated with an adhesive to obtain a laminated film. The structure of the laminated film is OPP / SiOx coated PET / SiOx coated P
VA / EEA. The SiOx-coated PET film and the SiOx-coated PVA film had their SiOx-coated surfaces adhered to each other.

Comparative Example 6 Instead of an OPP film having a thickness of 60 μm, a thickness of 150 μm
PET film (water vapor transmission rate: 3.7 g / m ² / d
A laminated film was obtained in the same manner as in Example 6 except that ay) was used. The constitution of the laminated film is PET / SiOx coated PET / SiOx coated PVA / EEA.

Example 7 Two types of films were used as the A layer. One uses the layer A obtained in Example 3, and the other uses 12 μm thick PVA.
An inorganic layer made of aluminum oxide-silicon oxide composite oxide having a specific gravity of 2.6 (b = 2.2) containing 40% by weight of aluminum oxide was formed on one surface of the film by vapor deposition.
Obtained by coating with 0 nm. 60 μm thick OPP film as layer B (water vapor transmission rate: 2.1
g / m ² / day) was used. In addition, P of the other A layer
EEA was extrusion-laminated to a thickness of 50 μm on the opposite surface of the VA film to form a sealant layer. Each film was dry laminated with an adhesive to obtain a laminated film. The structure of the laminated film is OPP / Al ₂
O ₃ -SiO ₂ coated PET / Al ₂ O ₃ -SiO ₂ coated PVA / EEA. Al ₂ O ₃ -SiO ₂ coated PET film and Al ₂ O ₃ -SiO ₂ coated PVA
The Al ₂ O ₃ —SiO ₂ coated surfaces of the film were bonded together.

Comparative Example 7 150 μm thick instead of 60 μm thick OPP film
A laminated film was obtained in the same manner as in Example 7 except that PET (water vapor transmission rate: 3.7 g / m ² / day) was used. The structure of the laminated film is PET / Al ₂ O ₃ —Si
O ₂ coated PET / Al ₂ O ₃ -SiO ₂ coated PVA
/ EEA.

The constitutions of the laminated films obtained in Examples 1 to 7 and Comparative Examples 1 to 7 are shown in Table 1. The water vapor permeability of the organic layer, the light transmittance of the laminated film, and the water vapor permeability of the laminated film before and after the following treatments. Table 2 shows the increase in water vapor transmission rate
Shown in 90 mm x 110 mm for the obtained laminated film
As a test piece, a polytetrafluoroethylene having a thickness of 0.6 mm and 50 mm × 50 mm is installed at the center on the surface on the sealant layer side, and a thickness of 0.1 mm is further provided on the polytetrafluoroethylene.
A 90 mm x 110 mm polytetrafluoroethylene film was overlaid so that its outer shape was the same as the test piece, and this was passed between rolls heated to a roll pressure of 6 kgf / cm ² and a temperature of 140 ° C at a film feed rate of 1 m / min. Processed. After the treatment, the laminated film is peeled off from the polytetrafluoroethylene to measure the water vapor transmission amount thereof, and the value obtained by subtracting the water vapor transmission amount before the treatment from the water vapor transmission amount of the laminated film after this treatment is measured area. (50c
The value calculated by multiplying by m ² ) was defined as the amount of increase in water vapor transmission rate.

[0056]

[Table 1]

[0057]

[Table 2]

Experimental Example 1 Laminated films of Example 7 and Comparative Example 7 (90 mm × 1)
10 mm) was used to actually package an EL device of 15 mm × 40 mm. For the fluorescent layer, ZnS dispersed in a binder (cyanoresin) was used. An aluminum plate is used for the back electrode, on top of which a dielectric layer (BaTiO ₃ layer),
The fluorescent layer and the transparent electrode (ITO film) were sequentially stacked. This was laminated from both sides with a laminated film to obtain an EL device packaged with the laminated film shown in FIG. When the laminated film of Comparative Example 7 was used, air bubbles were generated particularly in the bonding portion between the laminated films, and it was not possible to laminate cleanly. This is 50 ℃ × 90% RH
Then, it was connected to an AC power source of 100 V and 400 Hz, continuously lit, and the luminance thereof was measured. 100% brightness after 0 hours
The change in luminance with time was observed. The results are shown in FIG.

[0059]

According to the present invention, it is possible to provide a laminated film having excellent transparency and excellent moisture resistance. In addition, the laminated film is excellent in processability and economical efficiency. Therefore, it is most suitable for an EL device package and can be suitably used for other applications requiring moisture proof performance.

[Brief description of drawings]

FIG. 1 E packaged with the laminated film of Experimental Example 1
It is a sectional view of an L element.

FIG. 2 is a graph showing changes over time in the brightness of EL devices packaged with the laminated films of Example 7 and Comparative Example 7. 1 Laminated film 2 Transparent electrode 3 Fluorescent layer 4 Dielectric layer 5 Electrode

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yozo Yamada 2-1-1 Katada, Otsu City, Shiga Prefecture Toyobo Co., Ltd. Research Laboratory

Claims (5)

[Claims] 1. A laminated film comprising an inorganic layer, wherein a test piece of the laminated film has a size of 90 mm × 110 mm, and a thickness of 0.6 mm, 50 mm × 5 at the center on one side thereof.
A polytetrafluoroethylene of 0 mm was placed, and a polytetrafluoroethylene film of 0.1 mm in thickness and 90 mm × 110 mm was laid on the polytetrafluoroethylene so that the test piece had the same outer shape, and the roll pressure was 6 kgf / cm ² ,
When the film is passed through a roll heated at a temperature of 140 ° C. at a feed rate of 1 m / min, the water vapor transmission rate of the laminated film increases by 2.5 × 10 ⁻³ before and after the treatment.
A laminated film which is g / day or less. 2. The laminated film according to claim 1, comprising a plastic film having an inorganic layer on at least one surface, and an organic layer having a thickness of 100 μm or less and a water vapor permeability of 6 g / m ² / day or less. 3. The laminated film according to claim 1, wherein the inorganic layer contains a metal oxide. 4. The inorganic layer contains aluminum oxide in an amount of 20 to 9
9% by weight, and the specific gravity of the inorganic layer is represented by the formula: D = 0.01A + b (wherein D is the specific gravity of the inorganic layer, A is the weight% of aluminum oxide in the inorganic layer, and b is 1. 6 to 2.2)
The laminated film according to claim 1 or 2, which satisfies the following. 5. The laminated film according to claim 2, wherein the organic layer comprises polypropylene or polyvinylidene chloride.