WO2018221116A1

WO2018221116A1 - Organic electroluminescent light-emitting device

Info

Publication number: WO2018221116A1
Application number: PCT/JP2018/017476
Authority: WO
Inventors: 勇也元村
Original assignee: 富士フイルム株式会社
Priority date: 2017-05-30
Filing date: 2018-05-02
Publication date: 2018-12-06
Also published as: JP2020129429A

Abstract

Provided is an organic electroluminescent light-emitting device that has a high degree of flexibility and also has high durability. This organic electroluminescent device comprises, in the following order: a resin substrate; a first gas barrier layer; a bonding layer; a polyimide resin substrate; a second barrier layer; and an organic electroluminescent light-emitting element.

Description

Organic electroluminescence light emitting device

The present invention relates to an organic electroluminescence light emitting device such as an organic electroluminescence display and an organic electroluminescence illumination device.

Organic EL light-emitting devices using organic electroluminescence materials (organic EL (Electro Luminescence) materials) are used for organic EL displays, organic EL lighting devices, and the like.

The organic EL light emitting device uses a glass plate, a metal plate, or the like as a support. However, in recent years, flexibility (flexibility) is also required for organic EL light emitting devices.
As an organic EL light-emitting device that meets the demand for flexibility, an organic EL light-emitting device that uses a flexible resin film as a support film (support) is known.

As an example, an organic EL light emitting device using a resin film as a support film has an electrode layer, an organic EL light emitting layer, etc. on a resin film substrate such as a polyimide film placed on a glass carrier or the like. After forming necessary layers such as a light emitting element and a passivation film, a sealing layer, an adhesive layer, and a sealing substrate, the film substrate is peeled off from the carrier, and the whole film substrate is replaced with a supporting film. Produced.

Here, the organic EL material is very sensitive to moisture.
Since a sealing layer, a passivation film, and the like are formed on the side opposite to the support film of the organic EL element, deterioration of the organic EL material due to moisture entering from this side can be prevented.
However, the support film is a polyethylene terephthalate film (PET film) or the like and does not have gas barrier properties. Therefore, in the conventional organic EL light emitting device having flexibility, the organic EL material is protected from moisture entering from the support film side by providing a gas barrier film between the film base and the organic EL light emitting element. Yes.

For example, in Patent Document 1, a silicon oxynitride film is formed as a gas barrier layer on both sides of a PET film, an ITO (Indium Tin Oxide) film is formed as a transparent anode on one surface, and an organic layer is formed on the ITO film. An organic EL light-emitting device provided with an EL light-emitting layer, and a transparent barrier film sheet having a silicon oxynitride film formed on one surface of a PET film, bonded to each other as a base material. An organic EL light emitting device provided with an ITO film and an organic EL light emitting layer is described.

In Patent Document 2, a layer having a gas barrier property such as silicon nitride and silicon oxynitride is formed as a first insulating layer on the surface of a film substrate made of a PET film or the like. Describes a light emitting device that forms an element portion including a light emitting element including an EL layer using an organic EL material and a switching element.

Japanese Patent Laying-Open No. 2015-166075 JP2015-233301A

Patent Documents 1 and 2 provide a gas barrier layer (a layer having gas barrier properties) between the film substrate and the organic EL light-emitting device, thereby preventing deterioration of the organic EL material due to moisture entering from the support film side. In addition, it is described that an organic EL light emitting device having durability can be obtained.
However, according to the study of the present inventor, the conventional organic EL light-emitting device does not yet have sufficient flexibility and durability.

An object of the present invention is to solve such problems, and to provide an organic EL light emitting device having high flexibility and high durability.

In order to achieve this object, an organic electroluminescence light emitting device of the present invention comprises a resin substrate, a first gas barrier layer, an adhesive layer, a polyimide resin substrate, a second gas barrier layer, and an organic electroluminescence light emitting element. An organic electroluminescence light-emitting device characterized by having the components in this order is provided.

In such an organic electroluminescence light emitting device of the present invention, the first gas barrier layer preferably has one or more combinations of an inorganic layer and an organic layer serving as a base of the inorganic layer.
The inorganic layer is preferably a layer having silicon nitride as a main component and a thickness of 150 nm or less.
Moreover, it is preferable that a heat radiation layer is provided on the surface of the resin base material opposite to the side on which the first gas barrier layer is formed.
Moreover, it is preferable that a thermal radiation layer contains one or more of a carbon material, a metal material, a ceramic material, and a silicone material.
Moreover, it is preferable that the heat dissipation layer has a larger thermal conductivity in the plane direction than that in the thickness direction.
Furthermore, the top emission type is preferable.

According to the present invention, an organic EL light emitting device having high flexibility and high durability can be obtained.

It is a figure which shows notionally an example of the organic electroluminescent light emitting device of this invention. It is the elements on larger scale of FIG. It is a figure which shows notionally another example of the organic electroluminescent light-emitting device of this invention.

Hereinafter, the organic electroluminescence light emitting device (organic EL light emitting device) of the present invention will be described in detail.
The organic EL light-emitting device of the present invention is suitably used as an example for an organic EL display and an organic EL lighting device. Hereinafter, an embodiment of an organic EL light emitting device of the present invention will be described based on the drawings.

FIG. 1 conceptually shows an organic EL light emitting device 10 according to the first embodiment of the present invention.
The organic EL light-emitting device 10 includes a resin base 12, a first gas barrier layer 14 provided on one main surface of the resin base 12 (upper main surface in FIG. 1) in the following order, and an adhesive layer 16, a polyimide resin substrate 18, a second gas barrier layer 20, and an organic EL light emitting element 24.
The main surface is the maximum surface. Moreover, in the following description, the upper side indicates the organic EL light emitting element 24 side (upper side in FIG. 1), and the lower side indicates the resin base material 12 side (lower side in FIG. 1).

The organic EL light-emitting device 10 is a known organic EL light-emitting device (such as an organic EL display and an organic EL lighting device) such as a passivation film, a sealing layer, an adhesive layer, and a sealing substrate, if necessary. You may have various layers (film | membrane) which has.
In this regard, the same applies to the organic EL light emitting device 34 according to a second embodiment of the present invention described later.

Hereinafter, details of each component of the organic EL light emitting device according to the first embodiment will be described.

(Resin substrate 12)
The resin substrate 12 may be a known resin sheet (film) used as a support in various gas barrier films and various laminated functional films.

There is no restriction | limiting in the material of the resin base material 12, if the 1st gas barrier layer 14 can be formed, various resin materials can be utilized.
Examples of the material of the resin substrate 12 include polyethylene (PE), polyethylene naphthalate (PEN), polyamide (PA), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyvinyl alcohol (PVA), polyacrylonitrile ( PAN), polyimide (PI), transparent polyimide, polymethyl methacrylate resin (PMMA), polycarbonate (PC), polyacrylate, polymethacrylate, polypropylene (PP), polystyrene (PS), acrylonitrile / butadiene / styrene copolymer ( ABS), cyclic olefin copolymer (COC), cycloolefin polymer (COP), and triacetyl cellulose (TAC).

The thickness of the resin base material 12 can be appropriately set according to the use, material, and the like.
The thickness of the resin base material 12 ensures a sufficient mechanical strength of the organic EL light-emitting device 10, ensures the flexibility (flexibility) of the organic EL light-emitting device 10, and reduces the weight and thickness. From this viewpoint, the thickness is preferably 5 to 150 μm, and more preferably 10 to 100 μm.

The resin base material 12 may have a functional layer on the surface. Examples of the functional layer include a protective layer, an adhesive layer, a light reflection layer, an antireflection layer, a light shielding layer, a planarization layer, a buffer layer, and a stress relaxation layer.
Moreover, it is preferable that the resin base material 12 has high surface smoothness.

(First gas barrier layer 14)
The first gas barrier layer 14 is provided on the resin base material 12.
The organic EL light emitting device 10 basically includes a gas barrier film in which a first gas barrier layer 14 is formed on a resin substrate 12, and a second gas barrier layer 20 and an organic material on a polyimide resin substrate 18 that is a film substrate. The organic EL light-emitting device body on which the EL light-emitting element 24 is formed is prepared by bonding the first gas barrier layer 14 and the polyimide resin base material 18 with the adhesive layer 16. That is, in the organic EL light emitting device 10, the gas barrier film in which the first gas barrier layer 14 is formed on the resin base material 12 serves as a support film in the organic EL light emitting device 10.

There is no restriction | limiting in the 1st gas barrier layer 14, Various layers (film | membrane) utilized as a gas barrier layer in a well-known gas barrier film can be utilized. Examples of the first gas barrier layer 14 include a layer made of an inorganic compound, such as a silicon nitride layer, a silicon oxide layer, a silicon oxynitride layer, and an aluminum oxide layer.
Here, in the present invention, as a preferable first gas barrier layer 14, as conceptually shown in FIG. 2 in an enlarged view of FIG. 1, an inorganic layer 30 that exhibits gas barrier properties and a base of the inorganic layer 30 are used. An organic / inorganic laminated gas barrier layer having one or more combinations with the organic layer 28 can be used.

As shown in FIG. 2, the organic / inorganic laminated first gas barrier layer 14 is not limited to the one having only one combination of the organic layer 28 and the inorganic layer 30 as a base.
That is, the organic / inorganic laminated first gas barrier layer 14 includes two sets of combinations of the organic layer 28 and the inorganic layer 30 serving as a base, such as the organic layer 28, the inorganic layer 30, the organic layer 28, and the inorganic layer 30. 3 sets of combinations of the organic layer 28 and the inorganic layer 30 serving as a base, such as the organic layer 28, the inorganic layer 30, the organic layer 28, the inorganic layer 30, the organic layer 28, and the inorganic layer 30. As described above, it may be included.
As the number of combinations of the organic layer 28 and the inorganic layer 30 serving as the base increases, a higher gas barrier property can be obtained. The smaller the number of combinations of the organic layer 28 and the inorganic layer 30 as the base, the more advantageous in terms of thinning, lightening, and flexibility of the organic EL light emitting device 10.

<Organic layer 28: base organic layer>
The organic layer 28 is a layer made of an organic compound obtained by polymerizing (crosslinking or curing) a monomer or oligomer, for example.
The organic layer 28 is a base organic layer that embeds irregularities on the surface of the resin substrate 12 and foreign matters attached to the surface. By having such an organic layer 28, it is possible to appropriately form the inorganic layer 30 that mainly exhibits gas barrier properties.
Moreover, by having the organic layer 28, the inorganic layer 30 will be in the state pinched | interposed into the organic layer 28 and the adhesion layer 16 mentioned later. Therefore, the organic layer 28 also functions as a buffer layer for the inorganic layer 30 when the organic EL light emitting device 10 is bent. Therefore, by having the organic layer 28, damage to the inorganic layer 30 when the organic EL light-emitting device 10 is bent can be prevented, and the organic EL light-emitting device 10 having more flexibility and durability can be obtained.

The organic layer 28 is formed, for example, by curing an organic layer forming composition containing an organic compound (monomer, dimer, trimer, oligomer, polymer, etc.). The composition for organic layer formation may contain only 1 type of organic compounds, and may contain 2 or more types.
The organic layer 28 contains, for example, a thermoplastic resin and an organosilicon compound. Examples of the thermoplastic resin include polyester, (meth) acrylic resin, methacrylic acid-maleic acid copolymer, polystyrene, transparent fluororesin, polyimide, fluorinated polyimide, polyamide, polyamideimide, polyetherimide, cellulose acylate, and polyurethane. , Polyether ether ketone, polycarbonate, alicyclic polyolefin, polyarylate, polyether sulfone, polysulfone, fluorene ring modified polycarbonate, alicyclic modified polycarbonate, fluorene ring modified polyester, and acrylic compounds. Examples of the organosilicon compound include polysiloxane.

The organic layer 28 preferably includes a polymer of a radical curable compound and / or a cationic curable compound having an ether group from the viewpoint of excellent strength and a glass transition temperature.
From the viewpoint of lowering the refractive index of the organic layer 28, the organic layer 28 preferably contains a (meth) acrylic resin mainly composed of a (meth) acrylate monomer or oligomer polymer. The organic layer 28 has high transparency and low light transmittance by reducing the refractive index.

The organic layer 28 is more preferably bifunctional or more, such as dipropylene glycol di (meth) acrylate (DPGDA), trimethylolpropane tri (meth) acrylate (TMPTA), dipentaerythritol hexa (meth) acrylate (DPHA), and the like. A (meth) acrylic resin having a (meth) acrylate monomer or oligomer as a main component, and more preferably a trifunctional or higher functional (meth) acrylate monomer or oligomer polymer as a main component ( Includes (meth) acrylic resin. A plurality of these (meth) acrylic resins may be used. A main component means a component with the largest containing mass ratio among the components to contain.

The composition for forming an organic layer preferably contains an organic solvent, a surfactant, a silane coupling agent and the like in addition to the organic compound.

There is no restriction | limiting in the thickness of the organic layer 28, According to the component contained in the composition for organic layer formation, and the resin base material 12 used, it can set suitably.
The thickness of the organic layer 28 is preferably 0.5 to 5 μm, and more preferably 1 to 3 μm. By setting the thickness of the organic layer 28 to 0.5 μm or more, the surface of the organic layer 28 can be flattened by embedding irregularities on the surface of the resin base material 12 and foreign matters attached to the surface. preferable. By setting the thickness of the organic layer 28 to 5 μm or less, cracks in the organic layer 28 can be prevented, the flexibility of the organic EL light-emitting device 10 can be increased, and the organic EL light-emitting device 10 can be made thinner and lighter. This is preferable.

When a plurality of organic layers 28 are provided, that is, when a plurality of combinations of the organic layers 28 and the inorganic layers 30 are provided, the thickness of each organic layer 28 may be the same or different.

The organic layer 28 can be formed by a known method corresponding to the material.
For example, the organic layer 28 can be formed by a coating method in which a composition for forming an organic layer is applied and the composition for forming an organic layer is dried. In the formation of the organic layer 28 by a coating method, the organic compound in the organic layer forming composition is polymerized (crosslinked) by irradiating the dried organic layer forming composition with ultraviolet rays as necessary. .

The organic layer 28 can be formed by so-called roll-to-roll. Hereinafter, “roll-to-roll” is also referred to as “RtoR”. RtoR is a roll formed by winding a long film formation target sheet, the film formation target sheet is sent out, the film formation target sheet is conveyed in the longitudinal direction, and film formation is performed in a roll shape. It is a manufacturing method wound around. By using RtoR, high productivity and production efficiency can be obtained.

<Inorganic layer 30>
The inorganic layer 30 is a thin film containing an inorganic compound and is provided on the surface of the organic layer 28. The inorganic layer 30 exhibits gas barrier properties.
The inorganic layer 30 is appropriately formed by being provided on the surface of the organic layer 28. The resin base material 12 has areas where it is difficult to deposit an inorganic compound, such as surface irregularities and shadows of foreign matter. By providing the organic layer 28 on the resin base material 12, the region where the inorganic compound is difficult to deposit is covered. Therefore, the inorganic layer 30 can be formed on the entire surface of the resin substrate 12 without any gap.

There is no restriction | limiting in the material of the inorganic layer 30, The inorganic compound used for the well-known gas barrier layer which consists of an inorganic compound which expresses gas barrier property can be utilized variously.
Examples of the material of the inorganic layer 30 include metal oxides such as aluminum oxide, magnesium oxide, tantalum oxide, zirconium oxide, titanium oxide, and indium tin oxide (ITO); metal nitrides such as aluminum nitride; metals such as aluminum carbide Silicon oxides such as silicon oxide, silicon oxynitride, silicon oxycarbide and silicon oxynitride carbide; silicon nitride such as silicon nitride and silicon nitride carbide; silicon carbide such as silicon carbide; these hydrides; these two kinds Inorganic compounds such as the above mixtures; and hydrogen-containing materials thereof. A mixture of two or more of these can also be used.
In particular, silicon nitride, silicon oxide, silicon oxynitride, aluminum oxide, and a mixture of two or more thereof are preferably used in that they have high transparency and can exhibit excellent gas barrier properties. Among these, silicon nitride is preferably used because it can exhibit excellent gas barrier properties. Here, the inorganic layer 30 is preferably composed mainly of silicon nitride. The phrase “having silicon nitride as a main component” means that the component having the largest content among the components contained in the inorganic layer is silicon nitride. As content of the silicon nitride with respect to the inorganic layer 30, 80 mass% or more is preferable, and 90 mass% or more is more preferable.

There is no restriction | limiting in the thickness of the inorganic layer 30, According to material, the thickness which can express the target gas barrier property can be set suitably.
The thickness of the inorganic layer 30 is preferably 10 to 150 nm, more preferably 12 to 100 nm, and even more preferably 15 to 75 nm.
By setting the thickness of the inorganic layer 30 to 10 nm or more, it is preferable in that the inorganic layer 30 that stably expresses sufficient gas barrier performance can be formed. In addition, the inorganic layer 30 is generally brittle, and if it is too thick, there is a possibility of causing cracks, cracks, peeling, etc. However, if the thickness of the inorganic layer 30 is set to 150 nm or less, cracks may occur. Can be prevented. Further, by setting the thickness of the inorganic layer 30 to 150 nm or less, when the organic EL light-emitting device 10 is bent, the inorganic layer 30 is prevented from cracking and peeling, and the organic EL light-emitting device 10 having high flexibility. It is also preferable in that it can be obtained.
In the case where the first gas barrier layer 14 is not an organic / inorganic laminated type gas barrier layer but does not have the organic layer 28 serving as a base, and is a layer formed only of the above-described inorganic compound layer, the inorganic layer For the same reason as 30, the thickness of the first gas barrier layer 14 is preferably 10 to 150 nm.

When a plurality of inorganic layers 30 are provided, that is, when a plurality of combinations of the organic layer 28 and the inorganic layer 30 are provided, the thickness of each inorganic layer 30 may be the same or different.

The inorganic layer 30 can be formed by a known method according to the material.
For example, CCP (Capacitively Coupled Plasma) -CVD (Chemical Vapor Deposition) and ICP (Inductively Coupled Plasm) -CVD and other plasma CVD, atomic layer deposition (ALD), magnetron sputtering and reactive sputtering, etc. Various gas phase film forming methods such as sputtering and vacuum deposition are preferable.
Note that the inorganic layer 30 is also preferably formed of RtoR.

(Protective organic layer)
In the organic EL light emitting device 10, the first gas barrier layer 14 may have a protective organic layer that protects the uppermost inorganic layer 30 on the uppermost inorganic layer 30 as necessary. By having the protective organic layer, the gas barrier property is prevented from being lowered due to the damage of the inorganic layer 30, and more excellent gas barrier property is obtained.
That is, if the organic / inorganic laminated first gas barrier layer 14 has one or more combinations of the organic layer 28 and the inorganic layer 30 serving as a base, the structure including the organic layer 28, the inorganic layer 30 and the organic layer, and The organic layer 28, the inorganic layer 30, the organic layer 28, the inorganic layer 30, and the organic layer 28 in addition to the combination of the organic layer 28 and the inorganic layer 30 serving as a base, Configurations having only layers are also available.
As the protective organic layer, the same organic layer as that described above can be used. Further, the thickness of the protective organic layer may be the same as or different from that of the organic layer 28.
The protective organic layer may be formed in the same manner as the organic layer 28.
With respect to such a protective organic layer, the same applies to the case where the first gas barrier layer 14 is not an organic / inorganic laminated type, but includes only an inorganic layer that does not have the organic layer 28 serving as a base.

The surface smoothness of the first gas barrier layer 14 is not limited. However, the inorganic layer 30 preferably has high surface smoothness.

(Polyimide resin substrate 18)
As described above, the organic EL light emitting device 10 is basically manufactured by bonding the gas barrier film and the organic EL light emitting device main body together with the adhesive layer 16.
The organic EL light emitting device main body is obtained by forming the second gas barrier layer 20 on the polyimide resin base material 18 serving as a film base material and forming the organic EL light emitting element 24 thereon.

As the polyimide resin base material 18, there are various sheet-like materials (films) made of a polyimide resin and a polyimide resin used as a base material for forming the organic EL light emitting element 24 in a known organic EL light emitting device. Is available. For example, various sheet materials made of polyimide and polyimide-based resins such as polyimide, fluorinated polyimide resin, polyamide resin, polyamideimide resin, and polyetherimide resin can be used.
Moreover, as polyimide resin base material 18, commercially available polyimide films, such as Kapton (made by Toray DuPont), Iupilex (made by Ube Industries), and Apical (made by Kaneka), can also be used suitably.

There is no restriction | limiting in the thickness of the polyimide resin base material 18, The thickness which can support the organic EL light emitting element 24 can be suitably set according to material.
The thickness of the polyimide resin substrate 18 is preferably 5 to 100 μm, more preferably 10 to 75 μm, and further preferably 15 to 50 μm.
By setting the thickness of the polyimide resin substrate 18 to 5 μm or more, it is preferable in that sufficient heat resistance and strength can be ensured, and an appropriate organic EL light emitting element 24 can be stably formed. In addition, it is preferable that the thickness of the polyimide resin base material 18 is 100 μm or less because the flexibility of the organic EL light-emitting device 10 can be increased, and the weight and thickness of the organic EL light-emitting device 10 can be reduced.

(Second gas barrier layer 20)
The second gas barrier layer 20 is formed on the polyimide resin base material 18.
The second gas barrier layer 20 is for preventing moisture that has passed through the polyimide resin base material 18 from entering the organic EL light emitting element 24 and deteriorating the organic EL material and the like.

There is no restriction | limiting in the 2nd gas barrier layer 20, In a well-known organic electroluminescent light-emitting device, it is between the polyimide resin base material 18 (film base material for forming the organic electroluminescent light emitting element 24), and the organic electroluminescent light emitting element 24. FIG. Various layers that provide gas barrier properties can be used.
As the 2nd gas barrier layer 20, the layer which consists of various inorganic materials illustrated in the above-mentioned inorganic layer 30 is mentioned, for example. Of these, a layer made of silicon nitride, silicon oxide, or the like is preferably used.
The second gas barrier layer 20 may be a single layer film or may be a multilayer film such as a laminated structure of silicon nitride and silicon oxide.

There is no restriction | limiting in the thickness of the 2nd gas barrier layer 20, According to the material of the 2nd gas barrier layer 20, the thickness which satisfy | fills the required gas barrier property can be set suitably.
The thickness of the second gas barrier layer 20 is preferably 10 to 2000 nm, more preferably 50 to 1000 nm, and further preferably 100 to 750 nm.
Setting the thickness of the second gas barrier layer 20 to 10 nm or more is preferable in that good gas barrier properties can be obtained. By setting the thickness of the second gas barrier layer 20 to 2000 nm or less, the flexibility of the organic EL light emitting device 10 can be increased, and the organic EL light emitting device 10 can be reduced in weight and thickness.

The second gas barrier layer 20 can be formed by a known method according to the material.
Examples of the method include a coating method, a printing method, and various gas phase film forming methods such as plasma CVD and sputtering exemplified for the inorganic layer 30 described above.
The second gas barrier layer 20 is also preferably formed of RtoR.

(Organic EL light emitting device 24)
The organic EL light emitting element 24 is formed on the second gas barrier layer 20.
The organic EL light emitting element 24 includes a transparent electrode layer (TFT (Thin Film Transistor), thin film transistor), a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode. It is a well-known organic EL light emitting element (organic EL element, organic EL device) that constitutes an organic EL light emitting device (OLED (Organic Light Emitting Diode)) such as an organic EL display and an organic EL lighting device.

Note that the organic EL light emitting device 10 of the present invention may have a known passivation film for covering the organic EL light emitting element 24 and protecting the organic EL light emitting element 24, as in the known organic EL light emitting device. .
Furthermore, the organic EL light-emitting device 10 of the present invention covers the organic EL light-emitting element 24 or the passivation film that covers the organic EL light-emitting element 24 in the same manner as the known organic EL light-emitting device. You may have a gas barrier film which seals. As the gas barrier film, a known gas barrier film obtained by forming a gas barrier layer of a silicon oxide layer, an aluminum oxide layer and a silicon nitride layer on a substrate such as a resin film can be used. Especially, the gas barrier film formed by forming the same organic-inorganic laminated type gas barrier layer as the 1st gas barrier layer 14 in a base material can be used suitably. The organic EL light emitting element 24 may be sealed with a gas barrier film by a known method using an adhesive tape, an adhesive layer, an adhesive layer, or the like.

(Adhesive layer 16)
As described above, the organic EL light emitting device 10 basically includes the gas barrier film in which the first gas barrier layer 14 is formed on the resin base 12, the second gas barrier layer 20 and the organic on the polyimide resin base 18. The organic EL light-emitting device body on which the EL light-emitting element 24 is formed is prepared by bonding the first gas barrier layer 14 and the polyimide resin base material 18 with the adhesive layer 16.
By having such a configuration, the present invention can realize the organic EL light-emitting device 10 that achieves both excellent flexibility and durability.

As described above, the conventional organic EL light-emitting device having flexibility forms a gas barrier layer (a layer exhibiting gas barrier properties) on a resin base film such as a polyimide film, and then on the gas barrier layer. An organic EL light emitting element is formed, then peeled off from a carrier such as glass, and the base film is transferred to a support film such as a PET film.
In the organic EL light emitting device, a passivation film or the like is provided so as to cover the organic EL light emitting element, thereby preventing deterioration of the organic EL material or the like due to intrusion of moisture or the like.
Here, the support film does not have gas barrier properties. However, in a flexible organic EL light-emitting element, by having a gas barrier layer between the film substrate and the organic EL light-emitting element, deterioration of the organic EL material and the like due to moisture entering from the resin substrate side is prevented. ing.

Such an organic EL light emitting device exhibits sufficient flexibility for applications requiring flexibility that is not so high, such as bending with a large curvature radius, and organic EL for a long period of time. Prevents deterioration of materials, etc., and exhibits sufficient durability.
However, according to the study of the present inventor, in the conventional organic EL light emitting device having flexibility, in an application requiring high flexibility, such as an application bent with a small curvature radius, in a short period of time. Luminous performance deteriorates and sufficient durability cannot be exhibited. That is, in the conventional organic EL light-emitting device having flexibility, high flexibility and durability cannot be obtained at the same time.
The present inventor has conducted extensive studies on this cause. As a result, in the conventional organic EL light-emitting device having flexibility, the gas barrier layer between the film base and the organic EL light-emitting element is thick, so that the gas barrier layer is cracked when bent with a small radius of curvature. It has been found that moisture penetrates from the cracked portion and the organic EL material deteriorates. That is, it has been found that a conventional organic EL light-emitting device having flexibility cannot obtain sufficient durability in applications that require high flexibility, that is, does not have sufficient flexibility.

On the other hand, the organic EL light emitting device 10 of the present invention includes an organic EL light emitting device body in which the second gas barrier layer 20 and the organic EL light emitting element 24 are formed on a polyimide resin base material 18 as a film base material, and a resin base material. The gas barrier film having the first gas barrier layer 14 formed on 12 is bonded to the first gas barrier layer 14 and the polyimide resin substrate 18 with the adhesive layer 16 facing each other.
The organic EL light emitting device 10 of the present invention having such a configuration can prevent the first gas barrier layer 14 from being damaged because the adhesive layer 16 functions as a buffer layer even when bent with a small radius of curvature. Therefore, even if the second gas barrier layer 20 is cracked due to bending with a small radius of curvature, the first gas barrier layer 14 can prevent moisture from entering the organic EL light emitting element 24 and prevent deterioration of the organic EL material. . Therefore, according to the present invention, it is possible to obtain the organic EL light emitting device 10 having both high flexibility and durability with improved durability against bending.

Furthermore, the organic EL light emitting device 10 of the present invention preferably uses the organic-inorganic laminated gas barrier layer described above as the first gas barrier layer 14.
The organic / inorganic laminated gas barrier layer exhibits a very high gas barrier property even with a thin inorganic layer 30 having a thickness of 150 nm, for example. Therefore, by using an organic-inorganic laminated gas barrier layer, the inorganic layer 30 can be made thin, and damage to the first gas barrier layer 14 due to bending can be more suitably prevented. Moreover, in the organic / inorganic laminated gas barrier layer, the inorganic layer 30 is sandwiched between the adhesive layer 16 and the organic layer 28. As a result, in addition to the buffer effect by the adhesive layer 16, the buffer effect by the organic layer 28 acts synergistically, and damage to the inorganic layer 30, that is, the first gas barrier layer 14 can be prevented.
Therefore, by using the organic / inorganic laminated gas barrier layer, it is possible to obtain the organic EL light-emitting device 10 having higher flexibility and durability with improved durability against bending.

There is no restriction | limiting in the adhesion layer 16, According to the material of the 1st gas barrier layer 14 and the polyimide resin base material 18, what can bond both with sufficient adhesive force (adhesive force) can use variously. .
For example, pressure-sensitive adhesives and pressure-sensitive adhesive sheets made of (meth) acrylic acid ester resin, polyurethane, (meth) acrylic resin, ethylene-vinyl acetate copolymer (EVA), polyolefin, silicone resin, epoxy resin, rubber-based materials, etc. , Pressure-sensitive adhesive tape, pressure-sensitive adhesive film, and adhesive.
A commercially available product can also be used for the adhesive layer 16. Commercially available products that can be used as the adhesive layer 16 include TEA Tape teas Barrier Transfer Tape 3rdG, Daicel CELVENUS series, Nagase ChemteX XNR5516Z, and 3M various highly transparent adhesives. Agent transfer tape series (such as 8146 series).
In addition, the adhesion layer 16 may contain the desiccant component which absorbs a water | moisture content as needed.

The thickness of the pressure-sensitive adhesive layer 16 is not limited, and the thickness that allows the first gas barrier layer 14 and the polyimide resin base material 18 to be bonded with sufficient adhesive force depending on the type and material of the pressure-sensitive adhesive layer 16. Can be set as appropriate.
The thickness of the adhesive layer 16 is preferably 1 to 300 μm, more preferably 5 to 200 μm, and even more preferably 10 to 100 μm.
By setting the thickness of the adhesive layer 16 to 1 μm or more, the first gas barrier layer 14 and the polyimide resin substrate 18 can be bonded together with sufficient adhesive force, and the first gas barrier layer 14 is prevented from being damaged by the buffer of the adhesive layer 16. This is preferable in that the effect can be suitably obtained, and it is possible to suitably follow the unevenness of the TFT and the pixel. By setting the thickness of the adhesive layer 16 to 300 μm or less, the flexibility of the organic EL light emitting device 10 can be increased, and the organic EL light emitting device 10 can be reduced in weight and thickness.

The pressure-sensitive adhesive layer 16 can be formed by a known method according to the material and form of the pressure-sensitive adhesive layer 16 such as a coating method and sticking of a sheet material.

FIG. 3 shows an organic EL light emitting device 34 according to the second embodiment of the present invention.
The organic EL light-emitting device 34 shown in FIG. 3 has the same configuration as that of the organic EL light-emitting device 10 shown in FIG. 1 except that the heat-radiating layer 36 and the second adhesive layer 38 are included. Accordingly, the same members are denoted by the same reference numerals, and the description will mainly be made on different members.

As shown in FIG. 3, the organic EL light-emitting device 34 has a heat dissipation layer 36 provided by a second adhesive layer 38 on the surface of the resin base 12 opposite to the first gas barrier layer 14.
By having such a heat dissipation layer 36, heat generated by driving the organic EL light emitting element 24 is suitably released, the organic EL light emitting element 24 is prevented from being heated, and the organic EL light emitting device 34 operates more stably. It becomes possible to make it.

(Heat dissipation layer 36)
There is no restriction | limiting in the thermal radiation layer 36, Various well-known thermal radiation layers (thermal conduction layer) used with various apparatuses (devices), such as a display and an illuminating device, can be utilized.
For example, graphite sheets, heat-dissipating sheets using carbon nanotubes and heat-dissipating layers using carbon materials such as heat-dissipating sheets in which carbon black is dispersed, metal sheets (metal foil) such as aluminum sheets and copper sheets, aluminum oxide and aluminum nitride, etc. And a ceramic sheet made of a compound having a high thermal conductivity, a silicone sheet containing a material having a high thermal conductivity such as metal particles and a metal filler, and the like.
As the heat dissipation layer 36, a commercially available heat dissipation sheet (heat conductive sheet) can also be suitably used. Examples of commercially available heat radiation sheets include PGS graphite sheets (manufactured by Panasonic), eGRAF (manufactured by Graftech), and heat radiation silicone rubber sheets (manufactured by Shin-Etsu Silicone).

The heat dissipation layer 36 preferably has a thermal conductivity in the plane direction that is greater than the thermal conductivity in the thickness direction. That is, it is preferable that the heat dissipation layer 36 has a heat conduction anisotropy with a large heat conduction in the surface direction in the surface direction and the thickness direction. Specifically, the thermal conductivity in the plane direction is preferably 5 times or more of the thermal conductivity in the thickness direction, more preferably 50 times or more, and even more preferably 100 times or more. .
The surface direction is the direction of the main surface of the resin base material 12. The thickness direction is, in other words, the stacking direction of the layers in the organic EL light emitting device 34 (10).

In an organic EL light emitting device such as an organic EL display and an organic EL lighting device, in particular, an organic EL display, a battery serving as a power source of the organic EL light emitting device or a driving device is provided on the side opposite to the organic EL light emitting element 24 of the resin base 12 There is a high possibility that a power supply unit is arranged.
As is well known, the battery and the power supply device are vulnerable to heat, and the output becomes unstable due to heating. Therefore, the heat dissipation layer 36 has thermal conductivity anisotropy with a large thermal conductivity in the plane direction, thereby suppressing the heat dissipation from the heat dissipation layer 36 to the battery, and the battery resulting from the heat dissipation from the organic EL light emitting device 34. Or heating of a power supply device can be prevented and the drive of the organic electroluminescent light-emitting device 34 can be stabilized more.
Examples of the heat dissipation layer 36 having such heat conduction anisotropy include a graphite sheet.

The thickness of the heat dissipation layer 36 is not limited, and a thickness capable of sufficient heat dissipation can be appropriately set according to the type and material of the heat dissipation layer 36.
The thickness of the heat dissipation layer 36 is preferably 1 to 100 μm, more preferably 5 to 75 μm, and even more preferably 10 to 50 μm.
Setting the thickness of the heat dissipation layer 36 to 1 μm or more is preferable in that sufficient heat dissipation is possible. By setting the thickness of the heat dissipation layer 36 to 100 μm or less, the flexibility of the organic EL light emitting device 34 can be increased, and the weight and thickness of the organic EL light emitting device 34 can be reduced.

(Second adhesive layer 38)
The heat dissipation layer 36 is affixed to the resin base material 12 by the second adhesive layer 38.
If the heat dissipation layer 36 can be directly formed (film formation) or affixed to the resin base material 12 according to the material of the heat dissipation layer 36, the second adhesive layer may not be provided. .
There is no restriction | limiting in the 2nd adhesion layer 38, According to the material of the thermal radiation layer 36 and the resin base material 12, what can bond both with sufficient adhesive force can be utilized variously. As the 2nd adhesion layer 38, what was illustrated by the above-mentioned 1st adhesion layer 16 is mentioned, for example.

There is no restriction | limiting in the thickness of the 2nd adhesion layer 38, According to the material of the thermal radiation layer 36 and the resin base material 12, the thickness which can bond both with sufficient adhesive force can be set suitably.
The thickness of the second adhesive layer 38 is preferably 1 to 300 μm, more preferably 5 to 200 μm, and even more preferably 10 to 100 μm.
By making the thickness of the 2nd adhesion layer 38 1 micrometer or more, it is preferable at points, such as the heat dissipation layer 36 and the resin base material 12 being bonded together with sufficient adhesive force. Setting the thickness of the second adhesive layer 38 to 300 μm or less is preferable in that the flexibility of the organic EL light emitting device 34 can be increased, and the organic EL light emitting device 34 can be reduced in weight and thickness.

(About the organic EL light emitting device of the present invention)
The organic EL light emitting device of the present invention may be a so-called top emission type or a so-called bottom emission type.
Here, the organic EL light-emitting device of the present invention uses a polyimide resin base material 18 as a base material for forming the organic EL light-emitting element 24. Further, as a preferable aspect, the first resin base material 12 of the gas barrier film is used. A heat dissipation layer 36 is provided on the surface opposite to the gas barrier layer 14.
Considering this point, the organic EL light-emitting device of the present invention is preferably a top emission type that emits light to the side opposite to the substrate on which the organic EL light-emitting element 24 is formed.

As mentioned above, although the organic EL light emitting device of the present invention has been described in detail, the present invention is not limited to the above embodiment, and various improvements or modifications may be made without departing from the gist of the present invention.

Hereinafter, the present invention will be specifically described with reference to examples. The present invention is not limited to the specific examples shown below.

[Example 1]
<Production of gas barrier film>
A PET film (A4300, manufactured by Toyobo Co., Ltd.) having a thickness of 100 μm was prepared as the resin substrate 12.

TMPTA (manufactured by Daicel Celltech), silane coupling agent (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.) and polymerizable acidic compound (KARAMER PM-21, manufactured by Nippon Kayaku Co., Ltd.) in a mass ratio of 14.1: 3. A composition was prepared by mixing at 5: 1.
An organic layer forming composition for forming the organic layer 28 by mixing 18.6 g of this composition, 1.4 g of an ultraviolet polymerization initiator (Lamberti, ESACURE KTO46) and 180 g of 2-butanone. Was prepared.

The prepared composition for forming an organic layer was applied to the surface of a resin substrate 12 (PET film). Application | coating of the coating material was performed so that the coating-film thickness might be set to 10 micrometers using a wire bar.
After applying the paint, the paint was dried by allowing it to stand at room temperature.
Next, the composition of the coating was cured by irradiating with ultraviolet rays from a high-pressure mercury lamp (integrated irradiation amount: about 1 J / cm ² ) in a chamber in which the oxygen concentration was 0.1% by a nitrogen substitution method. As a result, an organic layer 28 having a thickness of 1 μm was formed on the surface of the resin substrate 12.

A silicon nitride film having a thickness of 35 nm was formed as an inorganic layer 30 on the organic layer 28.
The inorganic layer 30 (silicon nitride film) was formed using a general CCP-CVD apparatus. As the source gas, silane gas (flow rate 160 sccm), ammonia gas (flow rate 370 sccm), hydrogen gas (flow rate 590 sccm), and nitrogen gas (flow rate 240 sccm) were used. The film forming pressure was 40 Pa. The power supply was a high frequency power supply with a frequency of 13.56 MHz, and the plasma excitation power was 2.5 kW.
As a result, a gas barrier film having the first gas barrier layer 14 composed of the organic layer 28 and the inorganic layer 30 on the resin substrate 12 as shown in FIG. 2 was produced (first gas barrier layer 14 = organic layer 28). -Inorganic layer 30).

<Creation of organic EL light emitting device body>
A polyimide film having a thickness of 25 μm (manufactured by Toray DuPont, Kapton) was prepared as the polyimide resin substrate 18.

A silicon nitride film was formed on one surface of the polyimide resin substrate 18 in the same manner as the inorganic layer 30.
As a result, a second gas barrier layer 20 having a thickness of 150 nm was formed on the surface of the polyimide resin substrate 18.

Aluminum was formed on the surface of the formed second gas barrier layer 20 by vacuum deposition so as to have a film thickness of 60 nm, thereby forming an anode.
A molybdenum oxide (MoO ₃ ) layer having a thickness of 2 nm was formed as a hole injection layer on the surface of the formed anode by a vacuum deposition apparatus, and a hole transport layer (α-NPD: Bis [ N- (1-naphthyl) -N-phenyl] benzidine) is 29 nm, CBP (4,4′-Bis (carbazol-9-yl) biphenyl) is the host material and 5% Ir (ppy) 3 (Tris (2 -phenylpyridinato) iridium) -doped light emitting layer 20 nm, BAlq (Bis- (2-methyl-8-quinolinolato) -4- (phenyl-phenolate) -aluminium (III)) layer 10 nm as a hole blocking layer, and As an electron transport layer, an Alq3 (Tris (8-hydroxy-quinolinato) aluminum) layer of 20 nm was deposited to form an organic electroluminescent layer.
Subsequently, lithium fluoride (LiF) is deposited on the surface of the obtained organic light emitting layer to 0.5 nm and aluminum is deposited to 1.5 nm in this order to form a transparent electrode (cathode) to form a second gas barrier layer. The organic EL light-emitting element 24 was formed on the surface of 20 to produce an organic EL light-emitting device body.
Further, aluminum oxide (Al ₂ O ₃ ) was formed as a passivation film on the organic EL light emitting device 24 so as to have a film thickness of 300 nm by sputtering.

Furthermore, a 25 μm-thick adhesive tape (manufactured by TESA, 25 μm barrier tape) was attached so as to cover the formed organic EL light emitting element 24 entirely.
Furthermore, the gas barrier film produced previously was affixed with the inorganic layer 30 facing the adhesive tape, and the organic EL light emitting element 24 was sealed.

<Preparation of organic EL light emitting device 10>
The inorganic layer 30 and the polyimide resin substrate 18 face each other, and the previously prepared gas barrier film and the organic EL light emitting device main body are bonded to a 25 μm thick adhesive layer 16 (manufactured by 3M, highly transparent adhesive transfer tape 8146). The organic EL light emitting device 10 as shown in FIG.

[Example 2]
In the production of the gas barrier film, after forming the inorganic layer 30, an organic layer (protective organic layer) was further formed on the inorganic layer 30 (first gas barrier layer 14 = organic layer 28 / inorganic layer 30 / protective organic layer). ).
An organic EL light emitting device 10 was produced in the same manner as in Example 1 except that this gas barrier film was used.
[Example 3]
In the production of the gas barrier film, after forming the inorganic layer 30, an organic layer 28 is further formed on the inorganic layer 30, and the inorganic layer 30 is further formed on the organic layer 28 (first gas barrier layer 14 Has an organic layer 28, an inorganic layer 30, an organic layer 28, and an inorganic layer 30 in this order).
An organic EL light emitting device 10 was produced in the same manner as in Example 1 except that this gas barrier film was used.
[Example 4]
In the production of the gas barrier film, the inorganic layer 30 was formed directly on the resin base material 12 without forming the organic layer 28 as a base (the first gas barrier layer 14 is the inorganic layer 30).
An organic EL light emitting device 10 was produced in the same manner as in Example 1 except that this gas barrier film was used.

[Example 5]
An organic EL light emitting device 10 similar to that in Example 3 was produced.
A 25 μm thick second adhesive layer 38 (manufactured by 3M, highly transparent adhesive transfer tape 8146) is formed on the surface of the resin base material 12 of the organic EL light emitting device 10 opposite to the surface on which the first gas barrier layer 14 is formed. -1), a graphite sheet (manufactured by Panasonic, PGS graphite sheet) was attached as the heat dissipation layer 36.
Thus, an organic EL light emitting device 34 as shown in FIG. 3 was produced.
[Example 6]
An organic EL light emitting device 34 as shown in FIG. 3 was produced in the same manner as in Example 5 except that the heat dissipation layer 36 was changed to an aluminum foil having a thickness of 20 μm.
[Example 7]
An organic EL light emitting device 34 as shown in FIG. 3 was produced in the same manner as in Example 5 except that the heat radiation layer 36 was changed to heat radiation silicone rubber (TC-BG, manufactured by Shin-Etsu Silicone Co., Ltd.).
In Examples 5 to 6, the first gas barrier layer 14 is the same as that of Example 3. Accordingly, the first gas barrier layer 14 includes the organic layer 28, the inorganic layer 30, the organic layer 28, and the inorganic layer 30 in this order.

[Comparative Example 1]
In the production of the organic EL light emitting device main body, the second gas barrier layer 20 was not formed on the surface of the polyimide resin substrate 18. That is, the organic EL light emitting element 24 was directly formed on the surface of the polyimide resin substrate 18.
A resin base material 12 (PET film) that does not have the first gas barrier layer 14 is attached to the polyimide resin base material 18 of the organic EL light-emitting element body by the adhesive layer 16 to produce an organic EL light-emitting device (first). 1 gas barrier layer 14 and no second gas barrier layer 20).

[Comparative Example 2]
A resin base material 12 (PET film) that does not have the first gas barrier layer 14 is attached to the polyimide resin base material 18 of the same organic EL light emitting element body as in Example 1 by the adhesive layer 16, and an organic EL light emitting device is thus obtained. It was produced (without the first gas barrier layer 14).

[Evaluation]
With respect to the organic EL light emitting devices of Examples 1 to 7 and Comparative Examples 1 and 2 thus manufactured, the durability, flexibility, and flexibility durability of the elements were evaluated.

<Element durability>
It was stored in an environment at 60 ° C. and a relative humidity of 90% for 100 hours. The occupancy ratio of dark spots with respect to the total light emitting area after storage was calculated, and the durability of the organic EL light emitting element 24 of the organic EL light emitting device was evaluated.
The evaluation is as follows.
AA: Dark spot occupancy is less than 2% A: Dark spot occupancy is 2% or more and less than 5% B: Dark spot occupancy is 5% or more and less than 20% C: Dark spot occupancy is 20% or more

<Flexibility>
The flexibility of the organic EL light emitting device was evaluated by a mandrel method based on JIS K 5600-5-1.
The evaluation is as follows.
A: Even if it is bent 100 times using a mandrel having a radius of less than 8 mm, peeling, folding and breakage do not occur.
B: When a mandrel having a radius of less than 8 mm is bent 100 times, peeling, bending, or breakage occurs, but even if a mandrel having a radius of 8 mm or more and less than 14 mm is bent 100 times, No peeling, breakage or breakage occurs.
C: When a mandrel having a radius of 14 mm or more is bent 100 times, any of peeling, bending, and breakage occurs.

<Flexible durability>
Using a mandrel having a radius of 20 mm, the organic EL light emitting device was bent 100 times by a mandrel method in accordance with JIS K 5600-5-1.
Thereafter, the organic EL light-emitting device was stored for 100 hours in an environment at 90 ° C. and a relative humidity of 90%, and the occupancy ratio of dark spots with respect to the total light-emitting area after storage was calculated to evaluate the flexible durability of the organic EL light-emitting device.
The evaluation is as follows.
AA: Dark spot occupancy is less than 2% A: Dark spot occupancy is 2% or more and less than 5% B: Dark spot occupancy is 5% or more and less than 20% C: Dark spot occupancy is 20% or more The results are shown in the table below.

As shown in Table 1, each of the organic EL light emitting devices of the present invention has good durability, flexibility, and flexibility durability. Examples 5 and 6 having the heat dissipation layer 36 have particularly excellent element durability. Example 5 using a graphite sheet as the heat dissipation layer 36 has good flexibility even if the heat dissipation layer 36 is provided. Further, Examples 1 to 4 exhibit the same durability as that before the bending test even after the bending test by the mandrel method.
In contrast, Comparative Example 1 that does not have the first gas barrier layer 14 provided on the resin substrate 12 and the second gas barrier layer 20 on the surface of the polyimide resin substrate 18 has poor durability. Moreover, although the comparative example 2 which has the 2nd gas barrier layer 20 but does not have the 1st gas barrier layer 14 provided in the resin base material 12 has the durability of an element, ie, initial durability, it is based on a mandrel method. It was considered that the second gas barrier layer 20 was damaged due to the bending test, and the flexibility durability was low.
From the above results, the effects of the present invention are clear.

It can be suitably used for an organic EL display or an organic EL lighting device.

DESCRIPTION OF

SYMBOLS

10, 34 Organic EL light-emitting device 12 Resin base material 14 1st gas barrier layer 16 Adhesion layer 18 Polyimide resin base material 20 2nd gas barrier layer 24 Organic EL light emitting element 28 Organic layer 30 Inorganic layer 36 Heat radiation layer 38 2nd adhesion layer

Claims

An organic electroluminescent light emitting device comprising a resin base material, a first gas barrier layer, an adhesive layer, a polyimide resin base material, a second gas barrier layer, and an organic electroluminescent light emitting element in this order.
The organic electroluminescence light-emitting device according to claim 1, wherein the first gas barrier layer has one or more combinations of an inorganic layer and an organic layer serving as a base of the inorganic layer.
The organic electroluminescence light-emitting device according to claim 2, wherein the inorganic layer is a layer having silicon nitride as a main component and a thickness of 150 nm or less.
The organic electroluminescence light-emitting device according to any one of claims 1 to 3, wherein a heat dissipation layer is provided on a surface of the resin substrate opposite to a side on which the first gas barrier layer is formed.
The organic electroluminescence light-emitting device according to claim 4, wherein the heat dissipation layer includes one or more of a carbon material, a metal material, a ceramic material, and a silicone material.
The organic electroluminescence light-emitting device according to claim 4 or 5, wherein the heat dissipation layer has a thermal conductivity in a plane direction larger than a thermal conductivity in a thickness direction.
The organic electroluminescence light-emitting device according to any one of claims 1 to 6, which is a top emission type.