JP2002018994A - Gas barrier material and organic electroluminescence element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier material having excellent gas barrier properties. SOLUTION: A pair of gas barrier auxiliary films having an almost equal size and almost equal tensile stress are formed on both main surfaces of a substrate comprising a polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas barrier material having improved polymer gas barrier properties, and an electroluminescent device using the same.

[0002]

2. Description of the Related Art In the field of foods and medicines, if there is intrusion of oxygen or water vapor from the outside air, the contents are deteriorated and cannot be stored for a long period of time. Therefore, a film having a gas barrier property capable of preventing such intrusion of outside air has been developed.

[0003] For example, Polymer Engineering and Science, Vol. 20, No. 22, 1543-1546.
The page (December, 1986) describes polyvinylidene chloride, polyacrylonitrile, polyvinyl alcohol, and the like as gas barrier films developed conventionally.

[0004]

However, since polyvinylidene chloride contains a chlorine atom and polyacrylonitrile contains a -CN group, there is an environmental problem at the time of disposal. Further, polyvinyl alcohol is -OH
Since it contains a group, there is a problem that the humidity dependence of the gas barrier property is large, and the gas barrier property is significantly reduced at high humidity. Even an ethylene-vinyl alcohol copolymer having improved humidity dependency of polyvinyl alcohol does not have sufficient gas barrier properties at high humidity.
In addition, these polymer materials also have a temperature dependency, and there is a problem that gas barrier properties are significantly reduced at high temperatures.

In the field of electronic devices, inorganic materials such as Si wafers and glass have been widely used as substrates for electronic devices. However, in recent years, polymer substrates have been desired for various reasons, such as reduction in weight of products, flexibility of substrates, cost reduction, and handling characteristics. However, polymer materials have significantly higher gas permeability when compared to inorganic materials such as glass. The gas barrier property of the polymer material has a problem of humidity dependency and temperature dependency as described above.

For this reason, when a polymer substrate is used as a substrate for an electronic device, the device is oxidized and deteriorated by oxygen penetrating and diffusing into the electronic device through the polymer substrate. The required degree of vacuum cannot be maintained. For example, Japanese Patent Application Laid-Open No. 2-25
No. 1429 and JP-A-6-124785,
A polymer film is used as a substrate for an organic electroluminescence device. However, in the case of these organic EL devices, the organic film is deteriorated by oxygen or water vapor penetrating into the organic EL device through the polymer film serving as the substrate, so that the light emission characteristics become insufficient, Problems such as concerns about durability may be considered.

That is, as described above, a polymer having excellent gas barrier properties, which has sufficient gas barrier properties in various fields and can ensure good quality of a gas barrier object by the gas barrier properties. The fact is that the film has not been established yet.

Accordingly, the present invention has been made in view of the above-mentioned conventional circumstances, and has as its object to provide a gas barrier material having excellent gas barrier properties.

[0009]

A gas barrier material according to the present invention comprises a pair of gas barrier auxiliary films having substantially equal tensile stresses formed on both main surfaces of a polymer substrate. It is characterized by the following.

The gas barrier material according to the present invention is obtained by forming a gas barrier auxiliary film having tensile stress on a polymer substrate. As a result, a predetermined amount of compressive stress is applied to the polymer substrate by a predetermined amount of tensile stress of the gas barrier auxiliary film. Thus, in the gas barrier material, the cohesive energy density δ of the polymer substrate increases, and the free volume fraction fv decreases. As a result, the gas permeability coefficient P of the polymer substrate decreases. That is, in the gas barrier material, the gas permeability of the polymer substrate is reduced by forming the gas barrier auxiliary films on both main surfaces of the polymer substrate. Therefore, the gas barrier material has an improved gas barrier property of a substrate made of a polymer, and has an excellent gas barrier property.

An organic electroluminescent device (hereinafter, referred to as an organic EL device) according to the present invention is provided on a substrate.
A first electrode made of a light-transmitting material, an organic electroluminescent layer having a light-emitting material made of an organic compound, and a second electrode are provided in this order, and the substrates are arranged on both main surfaces of a polymer made substrate. A pair of gas barrier auxiliary films having substantially the same magnitude of tensile stress are formed.

In the organic EL device according to the present invention, a pair of gas barrier auxiliary films having substantially equal tensile stresses are formed on both main surfaces of a polymer substrate. Accordingly, a predetermined amount of compressive stress is applied to the polymer substrate of the organic EL element by a predetermined amount of tensile stress of the gas barrier auxiliary film. Thereby, in this organic EL element, the cohesive energy density δ of the polymer substrate increases, and
The free volume fraction fv decreases. As a result, the gas permeability coefficient P of the polymer substrate decreases. That is, in this organic EL element, the gas permeability of the polymer substrate is reduced by forming the gas barrier auxiliary films on both main surfaces of the polymer substrate. Therefore, in this organic EL element, the gas barrier property of the polymer substrate is improved, and the organic EL element has an excellent gas barrier property.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. The present invention is not limited to the following description, and can be appropriately modified without departing from the gist of the present invention.

It is known that the gas barrier property of a polymer material largely depends on the skeleton segment of the main chain of the polymer and the type of the side chain group. It is generally said that a polymer material having a high gas barrier property has a rigid skeleton segment and a group having a high polarity and a large cohesive force. Conversely, a polymer material having a flexible skeleton segment or a large side chain has a low gas barrier property. That is, the gas barrier property of the polymer material is directly related to the cohesive energy density δ of the polymer material and the free volume fraction (free volume) fv which is an index of the ease of movement of molecules.

[0015] From this, Dr. Morris Salame, Fut
ure-Pack '85 Proceeding, p. 119 (Dec. 3 to 5, 1985) proposes a method for estimating gas permeability from polymer constituent units. The basic idea is that first, a specific Permachol value relating to the cohesive energy density δ and the free volume fraction fv of the polymer material is given to the skeleton segment and the side chain. The gas permeation coefficient is determined from the permacol value of the entire material obtained by adding the permacol values of the side chain and the permacol values of the side chains.
The Permacol value Π can be expressed by the following equation 1 using the cohesive energy density δ and the free volume fraction fv.

[0016]

(Equation 1)

The gas permeation coefficient P is represented by the following equation (2).

[0018]

(Equation 2)

Here, A and s are constants specific to the gas.
It is also reported that the calculated results showed good agreement with the experimental results.

From the above equations (1) and (2), the gas permeability coefficient P of the polymer material is reduced by increasing the cohesive energy density δ of the polymer material and decreasing the free volume fraction fv. It can be seen that it is possible to lower the gas permeability of the sample. That is, it can be said that the gas barrier property can be improved by compressing the polymer material with some force from the outside.

On the other hand, the volume free fraction of the polymer material is an index of the easiness of the movement of the molecular chain, so that the value naturally increases as the temperature rises. Further, a polymer material containing a hydroxyl group has a high gas barrier property in a dry environment, but in a high humidity environment, water molecules form a hydrogen bond with a hydroxyl machine and the polymer is plasticized, and the cohesive energy density δ , The gas barrier property is reduced.

As described above, the gas barrier property of the polymer material is very unstable against the influence of heat from the outside and the influence of humidity. Therefore, in order to remove such an unstable element, by applying some compressive force to the polymer material, the cohesive energy density δ is reduced and the free volume fraction fv is reduced.
It can be said that it is effective to suppress the increase.

Therefore, the present invention is based on the above-mentioned theory, and applies a compressive force to a polymer material using the internal stress of a thin film to improve the gas barrier properties of the polymer material.

That is, in the present invention, a compressive force is applied to a substrate made of a polymer material by forming thin films having tensile stresses of substantially the same magnitude on both main surfaces of the substrate made of a polymer material. In addition, the gas barrier properties of a polymer substrate are improved. In this specification, the thin film having the above tensile stress is referred to as a gas barrier auxiliary film. Further, the substrate includes a thin film, a sheet, and a slightly thick plate.

Hereinafter, the present invention will be described using a gas barrier material in which a gas barrier auxiliary film is formed on a polymer film as an example.

FIG. 1 is a longitudinal sectional view of a main part of a gas barrier material to which the present invention is applied. As shown in FIG. 1, the gas barrier material 1 has a gas barrier auxiliary film 3 having tensile stresses of substantially equal magnitudes formed on both main surfaces of a polymer film 2.

The polymer film 2 serves as a support for the gas barrier material 1. The material constituting the polymer film 2 may be any polymer material having a smooth surface, and various polymer materials can be used depending on the application. Examples of such a polymer material include polyether terephthalate (PET) and polyether sulfone (PE).
S) and the like.

The gas barrier auxiliary film 3 applies a compressive stress to the polymer film, and the gas barrier auxiliary film 3 itself has a predetermined magnitude of tensile stress. Here, since the gas barrier auxiliary film 3 has a tensile stress, if the gas barrier auxiliary film 3 is formed only on one main surface of the polymer film 2, the polymer film 2 extends along the gas barrier auxiliary film 3 side. Therefore, the gas barrier auxiliary film 3 is formed on both main surfaces of the polymer film 2.

As a material that can be used for such a gas barrier auxiliary film 3, for example, TiW, SiO _2, SiN and the like can be mentioned. The material that can be used for the gas barrier auxiliary film 3 is not limited to these, and any material can be used as long as the material can control stress. Among them, a thin film having high hardness is said to have a large film stress, and can be suitably used.

Here, the predetermined tensile stress of the gas barrier auxiliary film 3 may be appropriately set according to various conditions such as the material and dimensions of the polymer film 2 and required gas barrier properties. However, if the gas barrier auxiliary film 3 has an excessively large tensile stress, the gas barrier auxiliary film 3 may be peeled off from the polymer film 2 due to the tensile stress when the gas barrier auxiliary film 3 is formed on the polymer film 2. Therefore, the magnitude of the tensile stress of the gas barrier auxiliary film 3 depends not only on the material and dimensions of the polymer film 2 but also on various conditions such as required gas barrier properties, as well as on the adhesion between the polymer film 2 and the gas barrier auxiliary film 3. It must be set in consideration of the above.

The thickness of the gas barrier auxiliary film 3 may be appropriately set in consideration of the above-described conditions and the tensile stress of the gas barrier auxiliary film 3.

The gas barrier auxiliary film 3 does not need to be formed of a single layer, but may be formed of a multilayer film in which a plurality of films are stacked. When the gas barrier auxiliary film 3 is composed of a multilayer film, it is not necessary that each film is composed of the same material, but may be composed of different materials. That is, for example, in consideration of the adhesion between the polymer film 2 and the gas barrier auxiliary film 3 and the like, the material of only the gas barrier auxiliary film 3 in contact with the polymer film 2 is made of a material having good adhesion to the polymer film 2. Alternatively, the other gas barrier auxiliary film 3 may be made of materials having different characteristics. At this time, the plurality of gas barrier auxiliary films 3
The tensile stress of each gas barrier auxiliary film 3 may be set so that the total tensile stress of the gas barrier auxiliary film 3 becomes a desired tensile stress.

The gas barrier material 1 constructed as described above
Is formed by forming a gas barrier auxiliary film 3 having substantially equal tensile stresses on both main surfaces of the polymer film, and by a predetermined magnitude of tensile stress of the gas barrier auxiliary film 3, Is subjected to a predetermined compressive stress. Thereby, this gas barrier material 1
Increases the cohesive energy density δ of the polymer film and decreases the free volume fraction fv. as a result,
The gas permeability coefficient P of the polymer film decreases. That is, in the gas barrier material 1, the gas permeability of the polymer film is reduced by forming the gas barrier auxiliary films 3 on both main surfaces of the polymer film. Therefore, the gas barrier material 1 has an excellent gas barrier property in which the gas barrier property of the polymer film 2 is improved and the dependency on humidity and temperature is suppressed.

The gas barrier material 1 may have a structure in which an adhesion layer is provided between the polymer film 2 and the gas barrier auxiliary film 3. FIG. 2 shows a configuration example of a gas barrier material in which an adhesion layer is provided between the polymer film 2 and the gas barrier auxiliary film 3.

The gas barrier material 4 includes a polymer film 5 and
Adhesion layers 6 formed on both main surfaces of polymer film 5
And a gas barrier auxiliary film 7 formed on the adhesion layer 6. The gas barrier auxiliary film 7 differs from the above-described gas barrier material 1 in that an adhesion layer 6 is formed between the polymer film 5 and the gas barrier auxiliary film 7. In the gas barrier auxiliary film 7, the polymer film 5
Since the adhesion layer 6 is formed between the polymer film 5 and the gas barrier auxiliary film 7, the adhesion between the polymer film 5 and the gas barrier auxiliary film 7 is good. Further, since the adhesion between the polymer film 5 and the gas barrier auxiliary film 7 is good, the magnitude of the tensile stress of the gas barrier auxiliary film 7 can be increased. Therefore,
Since the compressive force applied to the polymer film 5 can be increased, the gas barrier properties of the gas barrier material 4 can be further improved.

That is, in order to greatly improve the gas barrier properties of the gas barrier material, it is necessary to increase the compressive force applied to the polymer film. To increase the compressive force applied to the polymer film, the tensile stress of the gas barrier auxiliary film may be increased.

However, as described above, if the tensile stress of the gas barrier auxiliary film is excessively increased, that is, if the adhesive force between the polymer film and the gas barrier auxiliary film is increased, the gas barrier auxiliary film peels from the polymer film. Would. Therefore, there is a restriction that the magnitude of the tensile stress of the gas barrier auxiliary film must be smaller than the adhesion between the polymer film and the gas barrier auxiliary film. Therefore, in the gas barrier material 4, the adhesion layer 6 is provided between the polymer film 5 and the gas barrier auxiliary film 7.
Is provided to improve the adhesion between the polymer film 5 and the gas barrier auxiliary film 7. Thereby, the tensile stress of the gas barrier auxiliary film 7 can be further increased, and as a result, the compressive force applied to the polymer film 5 can be increased. As a result, the gas permeability coefficient of the polymer film 5 can be reduced, and the gas barrier properties of the gas barrier material 4 can be further improved.

Here, as a material that can be used as the adhesion layer 6, for example, Si can be mentioned. Further, the material that can be used as the adhesion layer 6 is not limited to Si, and any material can be used as long as an effect of improving the adhesion between the polymer film 5 and the gas barrier auxiliary film 7 can be obtained. Materials can also be used. The material used for the adhesion layer 6 may be appropriately determined in consideration of the material of the polymer film 5, the material of the gas barrier auxiliary film 7, and the like.

The gas barrier material configured as described above is
It can be manufactured as follows.

First, a polymer film, for example, a polymer film made of PET is prepared, and a thin film serving as a gas barrier auxiliary film, for example, a TiW thin film is formed on the main surface of the polymer film by DC sputtering. The film forming conditions are, for example, the following conditions.

Film formation conditions Input power: 1.0 to 3.0 kW Sputtering gas: Ar Sputtering gas pressure: 15 mTorr Sputtering target: TiW target Substrate temperature: about 70 ° C. Film thickness: 200 nm Here, tensile stress of the gas barrier auxiliary film Can be adjusted by changing the film forming conditions when forming the gas barrier auxiliary film. For example, when the gas barrier auxiliary film is formed by a DC sputtering method, a gas barrier auxiliary film having a desired magnitude of tensile stress can be obtained by adjusting input power during sputtering, sputtering gas pressure, and the like.

FIG. 3 shows the result of examining the change in the film stress of the TiW film when, for example, the TiW film is formed by changing the input power. From FIG. 3, while the input power is small, the film stress of the TiW film is a tensile stress,
As the input power increases, the tensile stress decreases. Then, near the input power exceeding 3 kW, the film stress of the TiW film changes from a tensile stress to a compressive stress. From this, it can be seen that when the TiW film is formed by the DC sputtering method, the type and magnitude of the film stress of the formed TiW film can be adjusted by changing the input power. .

Next, a case where the above-described gas barrier material is applied to a substrate of an organic electroluminescence device (hereinafter, referred to as an organic EL device) will be described.

FIG. 4 is a sectional view showing a main part of an example of the structure of an organic EL device to which the present invention is applied.

The organic EL element 11 is a film-shaped plastic substrate 12, a gas barrier auxiliary film 13 formed on both main surfaces of the film-shaped plastic substrate 12, and an anode formed on one of the gas barrier auxiliary films 13. A first electrode 14 and an organic electrode E formed on an anode serving as the first electrode 14;
L layer 20 and second electrode 1 formed on organic EL layer 20
8, a cathode as the second electrode 18 and an organic EL
And a protective layer 19 formed so as to cover the element 11.

The film-shaped plastic substrate 12 serves as a support for the organic EL element 11, and the layers constituting the organic EL element 11 are formed on the film-shaped plastic substrate 12.

Since the organic EL element 11 uses the film-shaped plastic substrate 12 as the substrate, it is significantly lighter than the organic EL element using a conventional glass substrate. Accordingly, when various devices are configured using the organic EL element 11, for example, when a large display or the like is configured, the devices can be reduced in weight, thereby increasing the degree of freedom in device design. It becomes possible.

Further, in this organic EL element 11, since the film-shaped plastic substrate 12 having good flexibility is used as the substrate, the organic EL element 11 itself has flexibility. That is, the organic EL element 11
In this case, since the film-shaped plastic substrate 12 is used as the substrate, unlike the conventional case where a glass plate or the like is used as the substrate, the organic EL element 11 has good flexibility by the flexibility of the film-shaped plastic substrate 12 itself. Can have a property. Since the organic EL element 11 has good flexibility by using the film-shaped plastic substrate 12 as the substrate, when various devices are configured using the organic EL element 11, for example, When a display or the like is configured, it is possible to take various forms of use such as being able to be rolled up and stored.

Then, the film-like plastic substrate 12
Does not exhibit brittleness unlike a glass substrate. Therefore, the organic EL element 11 using such a film-shaped plastic substrate 12 is more likely to be broken by an external impact such as dropping, that is, easier to break than an organic EL element using a conventional glass substrate. Therefore, impact resistance against external impact can be greatly improved. As a material used for the film-shaped plastic substrate 12, for example, PET, polyethylene naphthalate (PEN), PES, polyolefin (PO), or the like can be preferably used. The material used for the film-shaped plastic substrate 12 is not limited to these materials, and any material having good optical characteristics can be used.

Then, the film-like plastic substrate 12
Is preferably 50 μm or more and 500 μm or less. This is because, when the thickness of the film-shaped plastic substrate 12 is less than 50 μm, it is difficult for the film-shaped plastic substrate 12 itself to maintain sufficient flatness. This is because it may be difficult to maintain good flatness of the element 11. In addition, the film-shaped plastic substrate 1
When the thickness of the film-shaped plastic substrate 12 is larger than 500 μm, it is difficult to freely bend the film-shaped plastic substrate 12 itself, that is, the flexibility of the film-shaped plastic substrate 12 itself becomes poor. This is because when configured, the flexibility of the organic EL element 11 deteriorates.

The gas barrier auxiliary film 13 applies a compressive stress to the film-like plastic substrate 12, and the gas barrier auxiliary film 13 itself has a predetermined magnitude of tensile stress. Here, since the gas barrier auxiliary film has a tensile stress, the gaseous plastic substrate 12
When formed on only one main surface, the film-shaped plastic substrate 12 extends along the gas barrier auxiliary film 13 side. Therefore, the gas barrier auxiliary film 13 is formed on both main surfaces of the film-shaped plastic substrate 12.

The anode material used for the first electrode 14 serving as the anode is required to have a large work function from the vacuum level of the electrode material in order to inject holes efficiently and to take out organic electroluminescence from the anode side. In order to make it possible, it is preferable to use a light-transmitting material. Such materials include, for example, ITO (Indium Tin Oxide), SnO
Oxides such as ₂ are widely used.

The organic EL layer 20 includes a hole transport layer 15, a light-emitting layer 16, and an electron transport layer 17, and these layers are formed in this order on the first electrode 14 serving as an anode. Become.

The hole transport layer 15 is formed on the first electrode 1 serving as an anode.
The holes injected from 4 are transported to the light emitting layer 16. Materials that can be used as the hole transport material include benzene, styrylamine, triphenylmethane, porphyrin, triazole, imidazole, oxadiazole, polyarylalkane, phenylenediamine, arylamine, oxazole, anthracene, fluorenone, hydrazone, stilbene Or derivatives thereof, and heterocyclic conjugated monomers, oligomers, and polymers such as polysilane compounds, vinylcarbazole compounds, thiophene compounds, and aniline compounds.

Specifically, α-naphthylphenyldiamine, porphyrin, metal tetraphenylporphyrin,
Metal naphthalocyanine, 4,4 ′, 4 ″ -trimethyltriphenylamine, 4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine) triphenylamine, N, N, N ′, N '-Tetrakis (p
-Tolyl) p-phenylenediamine, N, N, N ',
N′-tetraphenyl 4,4′-diaminobiphenyl,
Examples include, but are not limited to, N-phenylcarbazole, 4-di-p-tolylaminostilbene, poly (paraphenylenevinylene), poly (thiophenvinylene), poly (2,2′-thienylpyrrole), and the like. is not.

In the light emitting layer 16, electrons and holes are combined,
The binding energy is emitted as light. In FIG. 4, the light emitting layer 16 is provided independently, but a hole transporting light emitting layer that also serves as the hole transporting layer 15 and the light emitting layer 16,
An electron-transporting light-emitting layer that also serves as the electron-transport layer 17 and the light-emitting layer 16 can be used. When the hole transporting light emitting layer is used, holes injected from the anode into the hole transporting light emitting layer are confined by the electron transporting layer, so that recombination efficiency is improved. When using an electron transporting light emitting layer,
Since electrons injected from the cathode into the electron-transporting light-emitting layer are confined in the electron-transporting light-emitting layer, recombination efficiency is improved as in the case of using the hole-transporting light-emitting layer.

The material of the light emitting layer 16 is such that holes can be injected from the anode side and electrons can be injected from the cathode side when a voltage is applied, and the injected charges, ie, holes and electrons, are moved. For example, an organic material such as a low-molecular fluorescent dye, a fluorescent polymer, or a metal complex which satisfies conditions such as providing a recombination field and high luminous efficiency can be used.

Examples of such materials include anthracene, naphthalene, phenanthrene, pyrene, chrysene, perylene, butadiene, coumarin, acridine, stilbene, tris (8-quinolinolato) aluminum complex, bis (benzoquinolinolato) beryllium complex, Tri (dibenzoylmethyl) phenanthroline europium complex, ditoluylvinylbiphenyl and the like can be mentioned.

The electron transport layer 17 is formed on the second electrode 1 serving as a cathode.
The electrons injected from 8 are transported to the light emitting layer 16. Examples of a material that can be used as the material of the electron transport layer 17 include quinoline, perylene, bisstyryl, pyrazine, and derivatives thereof.

Specific examples include aluminum 8-hydroxyquinoline, anthracene, naphthalene, phenanthrene, pyrene, chrysene, perylene, butadiene, coumarin, acridine, stilbene, and derivatives thereof.

As a cathode material used for the second electrode 18 serving as a cathode, it is preferable to use a metal having a small work function from the vacuum level of the electrode material in order to inject electrons efficiently.

Specifically, aluminum, indium,
Metals having a low work function, such as magnesium, silver, calcium, and barium lithium, may be used alone, or these metals may be used as an alloy with another metal with increased stability.

The protective layer 19 seals the organic EL element 11 and blocks oxygen and moisture in order to ensure the driving reliability of the organic EL element 11 and to prevent the organic EL element 11 from deteriorating. It works. As a material used for the protective layer 19, airtightness can be maintained, and a single metal or an alloy thereof which can transmit light emitted from the light emitting layer 16 can be appropriately selected and used. The protective layer 19 is preferably formed so as to cover not only the cathode but also the entire organic EL element 11 as shown in FIG. By forming the protective layer 19 so as to cover the entire organic EL element 1, it is possible to prevent oxygen or moisture from entering the organic EL element 11 from the outside.

Specifically, aluminum, gold, chromium,
Examples include niobium, tantalum, titanium, and silicon oxide.

Each of the layers constituting the above-mentioned organic EL element 11 may have a laminated structure composed of a plurality of layers.

The organic EL device 11 constructed as described above
Since the gas barrier auxiliary films 13 having substantially the same size are formed on both main surfaces of the film-like plastic substrate 12, the film-like plastic substrate 12
Is subjected to a predetermined compressive stress. With this, organic EL
In the element 11, the cohesive energy density δ of the film-shaped plastic substrate 12 can be increased, and the free volume fraction fv can be reduced. As a result, the gas permeability coefficient P of the film-shaped plastic substrate 12 can be reduced. That is, in the organic EL device 11, the gas permeability of the film-shaped plastic substrate 12 can be reduced by forming the gas barrier auxiliary films 13 on both main surfaces of the film-shaped plastic substrate 12, and the gas barrier property of the film-shaped plastic substrate 12 can be reduced. Can be improved. The organic EL element 11 has a gas barrier auxiliary film 1 on both main surfaces of a film-shaped plastic substrate 12.
By forming 3, the film-shaped plastic substrate 12 has a good gas barrier property, so that the invasion of oxygen, water vapor and the like through the substrate is prevented, and the organic EL having excellent light-emitting characteristics and durability. Element.

The organic EL device 11 constructed as described above
As described above, since the film-shaped plastic substrate 12 is used as the substrate, the weight can be significantly reduced as compared with a conventional organic EL element using a glass substrate.

The organic EL element 11 is a film-shaped plastic substrate 1 having good flexibility as a substrate.
2, the organic EL element 11 itself has good flexibility.

Since the organic EL element 11 uses a film-shaped plastic substrate 12 having excellent impact resistance against impacts such as dropping as a substrate, the impact resistance can be greatly improved.

Therefore, since the organic EL element 11 uses the film-shaped plastic substrate 12 as the substrate, it has the advantages described above. However, when a film-shaped plastic substrate is used as a substrate, the gas barrier properties of the substrate are insufficient, and in particular, they have temperature dependency and humidity dependency, so that stable and good gas barrier properties cannot be obtained. Therefore, this organic EL element 1
In No. 1, by applying the above-described gas barrier material to a substrate, an excellent organic EL device having both the above advantages and the gas barrier properties of the substrate is obtained.

The organic EL element 11 configured as described above
By selectively applying a DC voltage between the anode and the cathode, holes injected from the anode pass through the hole transport layer 15 and electrons injected from the cathode pass through the electron transport layer 4. It moves and reaches the light emitting layers 16 respectively. as a result,
In the light emitting layer 16, recombination of electrons and holes occurs,
From this, light of a predetermined wavelength is generated. The light emitting layer 16
By selecting the above materials, organic EL devices for full-color and multi-color emitting three colors of R, G and B can be obtained. The organic EL element 11 can be used, for example, for a display, but can also be used as a light source and the like, and can be used for various optical uses.

The above-described organic EL device 11 can be manufactured as follows.

First, as a substrate, for example, a 50 μm thick P
A film-shaped plastic substrate 12 made of ET is prepared, and a first electrode 14 made of, for example, a 10-nm-thick anode made of ITO is formed on both main surfaces of the film-shaped plastic substrate 12 by reactive DC sputtering.

The first electrode 14 which is the above-mentioned anode is
The organic EL layer 20 is formed thereon. The organic EL layer 20
The hole transport layer 15, the light emitting layer 16, and the electron transport layer 17 are formed by forming a film by vacuum deposition in this order. Here, the hole transport layer 15 is formed by, for example, forming m-HTDATA. The light emitting layer 16 is formed by, for example, forming α-NPD. And
The electron transport layer 17 is formed by, for example, forming AlQ ₃ . The thickness of the organic EL layer 20 is, for example, 150 nm.

Next, on the organic EL layer 20 formed as described above, for example, an AlT
An i film is formed to a thickness of 100 nm by sputtering.

Finally, an organic EL device 11 as shown in FIG. 4 can be manufactured by forming a 1000 nm thick protective layer 19 made of, for example, SiN so as to cover the layers formed above.

[0077]

As described in detail above, the gas barrier material according to the present invention comprises a pair of gas barrier auxiliary films having substantially equal tensile stresses on both principal surfaces of a polymer substrate. Be formed.

As a result, a predetermined amount of compressive stress is applied to the polymer substrate by the predetermined amount of tensile stress of the gas barrier auxiliary film, and the cohesive energy density δ of the polymer substrate increases. And the free volume fraction fv decreases. As a result, the gas permeability coefficient P of the polymer substrate can be reduced, and the gas permeability can be reduced.

Accordingly, the gas barrier material has improved gas barrier properties of the polymer substrate and has excellent gas barrier properties.

Therefore, according to the present invention, a gas barrier material having excellent gas barrier properties can be provided.

The organic electroluminescence device (hereinafter, referred to as an organic EL device) according to the present invention comprises a pair of substrates each having a tensile stress of substantially equal magnitude on both main surfaces of a polymer substrate. Is formed.

As a result, a predetermined amount of compressive stress is applied to the polymer substrate of the organic EL element by a predetermined amount of tensile stress of the gas barrier auxiliary film. The cohesive energy density δ increases and the free volume fraction fv decreases. As a result, the gas permeability coefficient P of the polymer substrate can be reduced, and the gas permeability of the polymer substrate can be reduced.

Therefore, this organic EL device has an improved gas barrier property of a substrate made of a polymer, and has an excellent gas barrier property.

Therefore, according to the present invention, it is possible to provide an organic EL device in which the substrate has excellent gas barrier properties.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a main part showing one configuration example of a gas barrier material to which the present invention is applied.

FIG. 2 is a vertical cross-sectional view of a main part showing another configuration example of the gas barrier material to which the present invention is applied.

FIG. 3 is a characteristic diagram showing a change in film stress of a TiW film when a TiW film is formed by changing input power.

FIG. 4 is a vertical cross-sectional view of a main part showing one configuration example of an organic EL element to which the present invention is applied.

[Explanation of symbols]

1 gas barrier material, 2 polymer film, 3 gas barrier auxiliary film, 4 gas barrier material, 5 polymer film, 6
Adhesion layer, 7 gas barrier auxiliary film

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 4F100 AA02 AA12 AA20 AB11 AK01A AK42 AK55 AR00B AR00C AR00D AR00E AT00A BA03 BA04 BA05 BA06 BA10B BA10C BA13 EH66 GB41 JD02 JD02B JD02J JD02J J02K JK02E

Claims (6)

[Claims] 1. A gas barrier material comprising a pair of gas barrier auxiliary films having substantially equal tensile stresses formed on both main surfaces of a polymer substrate. 2. The gas barrier material according to claim 1, wherein the gas barrier auxiliary film comprises a multilayer film in which a plurality of films are stacked. 3. The gas barrier material according to claim 2, wherein said plurality of films are made of different materials. 4. The gas barrier material according to claim 1, further comprising an adhesion layer between the substrate made of the polymer and the gas barrier auxiliary film. 5. A substrate comprising: a first electrode made of a light-transmitting material, an organic electroluminescent layer having a light-emitting material made of an organic compound, and a second electrode on a substrate in this order; An organic electroluminescence device comprising a pair of gas barrier auxiliary films having substantially equal tensile stresses formed on both main surfaces of a polymer substrate. 6. The organic electroluminescence device according to claim 5, wherein said substrate is a film-shaped plastic substrate.