JP2014154507A - Organic electroluminescent light emitting device, organic el display device, and organic el lighting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescent light emitting device which devises a sealing structure thereby preventing penetration and diffusion of moisture from the exterior and maintains stable light emitting characteristics for a long time.SOLUTION: In a sealing structure, a sealing layer including a thermoplastic resin and a protection layer having flexibility are provided on a rear surface of an organic electroluminescent element which includes a first electrode, an organic functional layer, and a second electrode on a translucent substrate. An organic electroluminescent light emitting device uses a metal foil, which has specific mechanical physical properties, on the protection layer.

Description

  The present invention relates to an organic electroluminescence (hereinafter also referred to as “organic EL”) light-emitting device, an organic EL display device, and organic EL illumination.

  The organic EL light-emitting device includes, for example, a light-transmitting substrate such as glass or plastic, an anode made of a transparent electrode, an organic functional layer made of an organic thin film, and an organic electroluminescence element in which a cathode is sequentially laminated. In recent years, it has been vigorously developed for practical use due to the fact that it exhibits surface emission with high luminance at a low voltage of a certain level and that light emission in an arbitrary color tone is possible by selecting a light emitting substance. .

  In organic EL light-emitting devices, when the organic functional layer and the cathode are left exposed to the atmosphere, the phenomenon that the non-light emitting area expands (shrink) so that the light emitting area of the organic functional layer contracts due to moisture in the atmosphere. As a result, it is known that the organic electroluminescence element deteriorates. Therefore, a sealing structure that blocks moisture is required. Therefore, for example, as shown in FIG. 7, a glass or metal sealing can 17 that blocks moisture is bonded to the back surface of the organic electroluminescence element with an adhesive 15 to form a hollow structure. A hollow seal in which a desiccant 16 is disposed inside has been proposed.

  However, in the case of this hollow sealing, since the moisture transmitted from the outside of the seal is absorbed by the desiccant to prevent deterioration, a recess is provided in the center for accommodating the desiccant as a sealing substrate. High cost materials such as glass and metal are required. Moreover, since there is a hollow space, it is difficult to dissipate heat generated by light emission, and there is a concern about shortening the life of the organic electroluminescence element. Furthermore, the takt time for applying the resin used for adhering the periphery of the sealing substrate is long, and when a glass frit is used, an expensive apparatus such as a laser is required.

  Therefore, a solid seal is proposed in which an adhesive is laminated directly on the electrode and the flat glass or metal foil as the sealing substrate is fixed via the adhesive to reduce cost, improve heat dissipation, and reduce the weight and weight. Has been. Specifically, a solid seal (patented with a dehydrating agent made of alkaline earth metal such as Ca around the light emitting region of the organic electroluminescent element, sealed with epoxy resin, and fixed with a glass plate) Reference 1), solid sealing in which an area wider than the cathode of the organic electroluminescence element is sealed with an ultraviolet curable resin containing crystalline zeolite, and a sealing substrate is adhered thereon (Patent Document 2), etc. Is mentioned.

Japanese Unexamined Patent Publication No. 2006-80094 Japanese Unexamined Patent Publication No. 2010-55861

However, in the sealing structure described in Patent Document 1, a thin dry layer is formed around the light emitting region of the organic electroluminescence element by depositing an alkaline earth metal such as Ca. Since the similar metals are very reactive, they are highly dangerous, and the number of steps for vapor deposition on the substrate increases, so that both the apparatus cost and the manufacturing time increase. In addition, the sealing structure described in Patent Document 2 has a problem in that the moisture absorption performance of the desiccant tends to decrease from the outside because the moisture absorbent mixed in the adhesive faces the atmosphere.

  Accordingly, an object of the present invention is to provide an organic EL light emitting device capable of preventing moisture permeation and diffusion from the outside without peeling off the sealing member and maintaining stable light emission characteristics for a long period of time. It is in. Moreover, the subject of this invention is providing the manufacturing method of the organic electroluminescent light emitting device which can manufacture such an organic electroluminescent light emitting device efficiently by a simpler process.

  As a result of studying in view of the above problems, the present inventors have used a metal foil having specific physical properties for the protective layer in a sealing structure in which a sealing layer and a protective layer are provided on the back surface of the organic electroluminescence element, thereby protecting the organic layer. It was found that an organic EL light-emitting device capable of maintaining stable light-emitting characteristics over a long period of time while suppressing deterioration due to moisture transmitted from the outside without peeling off the layers was found.

The gist of the present invention is as follows.
<1> A translucent substrate, a first electrode formed on the translucent substrate, an organic functional layer formed on the first electrode and having at least a light emitting layer, and the organic functional layer A sealing layer containing a thermoplastic resin formed so as to cover at least the surfaces of the first electrode, the second electrode, and the organic functional layer, and the sealing layer An organic electroluminescence light-emitting device comprising: a protective layer having flexibility, wherein the protective layer is a metal foil that satisfies the following formula (8).

F _0.2 <200 [N] (8)
(F _0.2 : Tensile force [N] when the permanent elongation in the tensile test of the protective layer metal foil cut to a width of 20 mm is 0.2%.)
<2> The organic electroluminescence light-emitting device according to <1>, further comprising a moisture absorption layer including a desiccant formed between the protective layer and the sealing layer so as to surround a light-emitting region of the light-emitting layer.
<3> The end of the moisture absorption layer protrudes 0.4 mm or more longer than the end of the light emitting region along the horizontal direction, and is shorter than the end of the sealing layer. Organic electroluminescence light emitting device.
<4> The organic electro according to <1> or <2>, wherein a thickness of the sealing layer in a region where the moisture absorption layer is not formed is thinner than a thickness of the sealing layer in the light emitting region. Luminescence light emitting device.
<5> The organic electroluminescence light emission according to any one of <2> to <4>, wherein an interval in a horizontal direction from an end of the hygroscopic layer to an end of the sealing layer is 0.1 mm or more. apparatus.
<6> The organic material according to any one of <2> to <5>, wherein the hygroscopic layer includes at least one selected from alkaline earth metals, alkali metals and oxides thereof, and inorganic porous materials. Electroluminescence light emitting device.
<7> The organic electroluminescence light-emitting device according to any one of <2> to <6>, wherein the moisture absorption layer has a thickness of 0.1 μm or more and 500 μm or less.
<8> The organic electroluminescence light emission according to <1> to <7>, wherein the thickness of the protective layer on the light emitting region is 0.3 times or more the thickness of the sealing layer on the light emitting region. apparatus.
<9> The organic electroluminescence light-emitting device according to any one of <1> to <8>, wherein the sealing layer has a thickness of 1 μm to 200 μm.
<10> The organic electroluminescence light-emitting device according to any one of <1> to <9>, wherein the protective layer has a thickness of 1 μm to 200 μm.
<11> The organic electroluminescence light-emitting device according to any one of <1> to <10>, wherein the protective layer metal foil is an aluminum foil.
<12> An organic EL display device using the organic electroluminescent light emitting device according to any one of <1> to <11>.
<13> Organic EL illumination using the organic electroluminescence light emitting device according to any one of <1> to <11>.

  The organic EL light-emitting device according to the present invention has a good barrier property against external moisture without peeling off the protective layer, so that deterioration of the organic electroluminescence element is suppressed, and as a result, stable light-emitting characteristics over a long period of time. Can be maintained. Further, the organic EL light emitting device of the present invention can be reduced in weight and thickness as compared with the conventional one, and the substrate can be recycled.

  Furthermore, according to the present invention, such an organic EL light emitting device can be efficiently manufactured by a simpler process.

FIG. 1 is a cross-sectional view showing an example of an organic EL light emitting device according to the present invention. FIG. 2 is a view for explaining how to obtain the pulling force F _{0.2 according to} the present invention. FIG. 3 is a sectional view showing another example of the organic EL light emitting device according to the present invention. FIG. 4 is a cross-sectional view showing an example of the manufacturing process of the organic EL light emitting device according to the present invention. FIG. 4 (a) shows a state where the first electrode 2 is formed on the surface of the translucent substrate 1, FIG. FIG. 4B is a view showing a state in which the organic functional layer 3 serving as a light emitting layer is formed on the first electrode 2, and FIG. 4C is a view showing a state in which the second electrode 4 is formed on the organic functional layer 3. . FIG. 5 is a plan view showing an example of the manufacturing process of the organic EL light emitting device according to the present invention. FIG. 5 (a) shows a flexible sheet serving as the protective layer 7, and FIG. 5 (b) shows the protective layer 7. FIG. 5C shows a state in which the protective layer 7 is cut piece by piece, and FIG. 5D includes a thermoplastic resin on the moisture absorbing layer 6. It is a figure which shows the state in which the sealing layer 5 was formed. FIG. 6 is a plan view showing another example of the manufacturing process of the organic EL light emitting device according to the present invention. FIG. 6 (a) shows a flexible sheet serving as the protective layer 7, and FIG. 6 (b) shows protection. FIG. 6 (c) shows a state in which the hygroscopic layer 6 is formed in a matrix on the surface of the layer 7, FIG. 6 (c) shows a state in which the protective layer 7 is cut piece by piece, and FIG. 6 (d) shows a thermoplastic resin on the hygroscopic layer 6. It is a figure which shows the state in which the sealing layer 5 containing was formed. FIG. 7 is a cross-sectional view showing an example of a conventional organic EL light emitting device. FIG. 8 is a view showing a method for forming the protective layer 7 into a concave shape in accordance with the shape of the moisture absorption layer 6, and FIG. 8A shows a state in which the moisture absorption layer 6 is formed on the protection layer 7, and FIG. ) Shows a state in which the hygroscopic layer 6 is on the lower surface, FIG. 8C shows a state in which the portion of the protective layer 7 not provided with the hygroscopic layer 6 is pressed, and FIG. It is a figure which shows the state which formed the sealing layer 5 in the flat surface shape from which the layer 6 became substantially the same. FIG. 9 is a diagram showing a state in which the organic EL element is sealed with the back member, FIG. 9A shows a state in which the back member is superimposed on the organic EL element, and FIG. 9B shows a heat press process. FIG.9 (c) is a figure which shows the organic EL element after a heat press process. FIG. 10 is a diagram showing an insulating film pattern of the example.

Hereinafter, preferred embodiments of the organic EL light-emitting device of the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. For the convenience of illustration, the dimensional ratios in the drawings do not necessarily match those described.
FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of the organic EL light-emitting device of the present invention.
An organic EL light emitting device 10 shown in FIG. 1 is composed of an organic electroluminescence element and a back member formed on the back surface thereof. Hereinafter, the organic electroluminescence element and the back member will be described in detail.

[Organic electroluminescence device]
The organic electroluminescence element of the organic EL light emitting device 10 includes a translucent substrate 1, a first electrode 2 formed on the translucent substrate 1, and an organic functional layer 3 formed on the first electrode 2. And the second electrode 4 formed on the organic functional layer 3. The light emitted from the light emitting layer of the organic functional layer 3 of the organic electroluminescence element is extracted through the translucent substrate 1.

A conventionally well-known thing can be employ | adopted for the structure of an organic electroluminescent element, and its constituent material, For example, the following can be mentioned as a constituent material.
(substrate)
The translucent substrate 1 serves as a support for the organic electroluminescence element, and a quartz or glass plate, a metal plate, a metal foil, a plastic film, a sheet, or the like can be used. In particular, a glass plate or a transparent synthetic resin plate such as polyester, polymethacrylate, polycarbonate, polysulfone or the like is preferable.

  When using a synthetic resin substrate, it is necessary to pay attention to gas barrier properties. If the gas barrier property of the translucent substrate 1 is too small, the organic electroluminescence element may be deteriorated by the outside air transmitted through the translucent substrate 1. For this reason, a method of providing a gas barrier property by providing a dense silicon oxide film or the like on at least one surface of a synthetic resin substrate is also a preferable method.

The thickness of the translucent board | substrate 1 is 0.01-10 mm normally, Preferably it is 0.1-1 mm.
(First electrode)
The first electrode 2 is an anode and plays a role of hole injection into the organic functional layer 3. This anode is usually made of metal such as aluminum, gold, silver, nickel, palladium, platinum, metal oxide such as oxide of indium and / or tin, metal halide such as copper iodide, carbon black, poly It is composed of conductive polymers such as (3-methylthiophene), polypyrrole and polyaniline.

  The thickness of the anode varies depending on the required transparency. When transparency is required, the visible light transmittance is usually 60% or more, preferably 80% or more. In this case, the thickness of the anode is usually 5 nm or more, preferably 10 nm or more, and the upper limit is usually 1000 nm, preferably 500 nm. When opaqueness is acceptable, the thickness of the anode is arbitrary, and the anode may be the same as that of the translucent substrate 1. Note that the first electrode 2 is usually a single layer structure, but may be a laminated structure made of a plurality of materials if desired.

(Organic functional layer)
The organic functional layer 3 may have a single layer structure or a multilayer structure as long as it has at least a light emitting layer. Examples of the multilayer structure include a three-layer structure including a hole injection transport layer, a light emitting layer, and an electron injection layer, and a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, and an electron injection layer. Examples thereof include a layer structure, and can be appropriately selected.

Examples of the hole transport material include porphyrin compounds, phthalocyanine compounds, quinacridone compounds, indanthrene compounds, aromatic amine compounds, and the like. Among them, an aromatic amine compound is preferable, and 4,4′-bis [N- (2-naphthyl) -N-phenyl-amino] biphenyl (α-NPD) represented by the following formula (1): 4,4′-bis [N- (9-phenanthryl) -N-phenyl-amino] biphenyl (PPD), spiro-NPB represented by the following formula (3), From the viewpoint of the heat resistance of the organic electroluminescence device, spiro- (TARO) TAD represented by (II) and 2-TNATA represented by the following formula (5) are particularly preferable.

  Examples of electron transport materials include oxadiazole derivatives, oxazole derivatives, thiazole derivatives, thiadiazole derivatives, pyrazine derivatives, triazole derivatives, triazine derivatives, perylene derivatives, quinoline derivatives, quinoxaline derivatives, fluorenone derivatives, anthrone derivatives, phenanthroline derivatives, organic Examples thereof include metal complexes, pyridine derivatives, pyrrolopyridine derivatives, pyrimidine derivatives, naphthyridine derivatives, silole derivatives, and the like.

As the charge transport material, the above-described hole transport material, electron transport material, and the like can be appropriately selected and used as long as the object of the present invention is not impaired. Of course, other materials can also be used.
Examples of the luminescent material include 9,10-diarylanthracene derivatives, pyrene, coronene, perylene, rubrene, 1,1,4,4-tetraphenylbutadiene, tris (8-quinolinolato) aluminum complex, tris (4-methyl- 8-quinolinolato) aluminum complex, bis (8-quinolinolato) zinc complex, tris (4-methyl-5-trifluoromethyl-8-quinolinolato) aluminum complex, tris (4-methyl-5-cyano-8-quinolinolato) aluminum Complex, bis (2-methyl-5-trifluoromethyl-8-quinolinolato) [4- (4-cyanophenyl) phenolate] aluminum complex, bis (2-methyl-5-cyano-8-quinolinolato) [4- ( 4-cyanophenyl) phenolate] aluminum complex , Tris (8-quinolinolato) scandium complex, bis [8- (para-tosyl) aminoquinoline] zinc complex and cadmium complex, 1,2,3,4-tetraphenylcyclopentadiene, pentaphenylcyclopentadiene, poly-2, 5-diheptyloxy-para-phenylene vinylene, coumarin phosphor, perylene phosphor, pyran phosphor, anthrone phosphor, porphyrin phosphor, quinacridone phosphor, N, N'-dialkyl-substituted quinacridone Examples thereof include low molecular materials such as phosphors, naphthalimide phosphors, N, N′-diaryl-substituted pyrrolopyrrole phosphors, and polymer materials such as polyfluorene, polyparaphenylene vinylene, and polythiophene.

The thickness of the organic functional layer 3 is not uniform due to a single layer structure or a multilayer structure, but is usually 1000 nm or less, and preferably 50 to 150 nm from the viewpoint of thinning.
As long as the object of the present invention is not impaired, a hole blocking layer, an electron transport layer, and the like may be formed by appropriately selecting a material on the light emitting layer.
(Second electrode)
The second electrode 4 is a cathode and plays a role of injecting electrons into the organic functional layer 3. The cathode can be made of the same material as that used for the anode, but a metal having a low work function is preferable for efficient electron injection. For example, tin, magnesium, indium, calcium, A suitable metal such as aluminum or silver or an alloy thereof is used. Specific examples include low work function alloy electrodes such as magnesium-silver alloy, magnesium-indium alloy, and aluminum-lithium alloy. Moreover, only 1 type may be used for the material of a cathode, and it may use it combining 2 or more types by arbitrary ratios.

Note that the thickness of the cathode is usually the same as that of the anode.
(Back member)
On the other hand, the back member of the organic EL light emitting device 10 includes a sealing layer 5 and a protective layer 7. The sealing layer 5 is formed so as to cover the exposed surface of the organic electroluminescence element on the light-transmitting substrate 1, and the sealing layer 5 according to this embodiment is the main surface of the light-transmitting substrate 1. And the anode 2, the organic functional layer 3 or the surface of the cathode layer 4 are in direct contact with and covered. A protective layer 7 is formed on the sealing layer 5 so as to cover it. Here, it is preferable that a moisture absorption layer 6 is formed between the sealing layer 5 and the protective layer 7 so as to be in contact with the protective layer 7. The moisture absorption layer 6 preferably used in the present embodiment is formed in a hollow rectangular shape so as to surround the light emitting region of the light emitting layer constituting the organic functional layer 3 while maintaining a constant interval along the outer periphery of the light emitting region. It is preferable that the entire light emitting region is covered.

  Further, in the back member when the moisture absorption layer 6 is formed, the end 6a of the moisture absorption layer 6 is longer in the horizontal direction than the light emitting region end 3a of the light emitting layer constituting the organic functional layer 3, And it is preferable that it is shorter than the edge part 5a of the sealing layer 5. FIG. That is, the end 6 a of the moisture absorbing layer 6 protrudes in the horizontal direction from the light emitting region end 3 a of the light emitting layer of the organic functional layer 3, and the end 5 a of the sealing layer 5 is It is preferable to protrude along the horizontal direction from the end 6a.

  Here, in this specification, the “end portion” refers to a portion that protrudes most outside the organic electroluminescence light emitting device along the horizontal direction, and the “horizontal direction” refers to the main surface of the translucent substrate 1. Parallel direction. In the present specification, the “light emitting region of the light emitting layer” refers to a region that emits light in the light emitting layer constituting the organic functional layer 3 when a voltage is applied between the electrodes. This is a region where the functional layer 3 and the second electrode 4 overlap each other, and is a region where light is emitted from the element to the outside. The “light emitting region end 3a of the light emitting layer” is the outermost end of the light emitting layer in the region where the first electrode 2, the organic functional layer 3 and the second electrode 4 overlap.

The distance x in the horizontal direction from the light emitting region end 3a of the light emitting layer to the end 6a of the hygroscopic layer 6 is preferably 0.4 mm or more, and more preferably 1 mm or more. The upper limit is preferably 50 mm, more preferably 10 mm.
It is preferable that x is 0.4 mm or more because moisture entering from the end of the back member can be efficiently absorbed by the moisture absorbing layer and deterioration of the light emitting layer can be suppressed.

  As a result of considering the member configuration for efficiently reaching the moisture absorbing layer with water molecules in the sealing layer that have entered from the end of the back member, the inventors have determined that the position of the water molecules in the sealing layer is the substrate. If the position in the horizontal direction is the end of the hygroscopic layer and the position in the vertical direction with respect to the substrate is an arbitrary position, the probability of reaching the hygroscopic layer while moving by a distance x is sealed. The conclusion was reached that the layer thickness is equal to or thinner than x. As will be described later, since the film thickness of the sealing layer is usually 200 μm or less, it is considered that there is a sufficient effect if it is twice or more this thickness. Therefore, x is estimated to be 0.4 mm or more.

Further, the distance y in the horizontal direction from the end 6a of the hygroscopic layer 6 to the end 5a of the sealing layer 5 is preferably 0.1 mm or more, and more preferably 1 mm or more. The upper limit is preferably 10 mm, more preferably 5 mm.
As described above, the back member of the organic EL light-emitting device 10 is a sealed member in which the sealing layer 5, preferably the moisture absorbing layer 6 and the protective layer 7 are sequentially laminated, and the end 6a of the moisture absorbing layer 6 is disposed at a predetermined position. When the stop is adopted, not only the moisture from the outside can be blocked, but also the heat dissipation of the heat generated by the light emitting layer is excellent. Therefore, deterioration of the organic electroluminescence element is suppressed, and stable light emission characteristics can be maintained over a long period of time.

Moreover, since the protective layer 7 is comprised with the flexible material, the organic electroluminescent light-emitting device 10 can implement | achieve weight reduction and thickness reduction compared with the past, and can implement | achieve cost reduction. Furthermore, since the sealing layer 5 contains a thermoplastic resin, when the organic electroluminescence element deteriorates, the thermoplastic resin of the sealing layer can be melted to recycle the substrate.
(Sealing layer)
Although it does not specifically limit as a thermoplastic resin contained in the sealing layer 5, For example, a polypropylene, polyethylene, a polystyrene, polyisobutylene, polyester, polyisoprene etc. can be mentioned. These can be used alone or in combination of two or more. Among these, polypropylene, polyethylene, and polyisobutylene are preferable from the viewpoint of low moisture permeability. Moreover, the glass transition temperature of a thermoplastic resin is normally -80 degreeC or more from a heat resistant viewpoint, Preferably it is -20 degreeC or more, and an upper limit is not specifically limited.

The sealing layer 5 may contain components other than the thermoplastic resin, and examples thereof include petroleum resins and cyclic olefin polymers.
Examples of petroleum resins include p. 14 of "14906 Chemical Products" (published by Chemical Industry Daily). 1192, C5 petroleum resin, C9 petroleum resin, C5C9 copolymer petroleum resin, and the like.

  Specifically, the cyclic olefin polymer includes hydrogenated terpene resins (for example, Clearon P, M, K series), hydrogenated rosin and hydrogenated rosin ester resins (for example, Foral AX, Foral 1105, Pencel A, Ester gum H, superester A series, etc.), disproportionated rosin and disproportionated rosin ester resins (eg, pine crystal series), pentene, isoprene, piperine, 1,3- Hydrogenated dicyclopentadiene resins that are hydrogenated resins of C5 petroleum resins obtained by copolymerizing C5 fractions such as pentadiene (for example, Escholets 5300, 5400 series, Eastotac H series, etc.), thermal decomposition of petroleum naphtha Such as indene, vinyltoluene, α or β-methylstyrene Resin obtained by hydrogenation of C9 petroleum resin obtained by copolymerization of 9 fractions (for example, Alcon P or M series), and resin obtained by hydrogenation of copolymerized petroleum resin of C5 fraction and C9 fraction described above (for example, , Imabe series).

For example, a filler, an ultraviolet absorber, an ultraviolet stabilizer, an antioxidant, a resin stabilizer, and the like may be appropriately added to the thermoplastic resin as long as the physical properties of the adhesive are not impaired.
The lower limit of the thickness of the sealing layer 5 is usually 1 μm or more, preferably 10 μm or more, and the upper limit is usually 200 μm or less, preferably 150 μm or less, more preferably 100 μm or less.

In addition, when not forming the moisture absorption layer 6 mentioned later, it is preferable to make the sealing layer 5 contain a desiccant.
(Hygroscopic layer)
Although the moisture absorption layer 6 preferably used in the present invention contains a desiccant, the desiccant is not particularly limited as long as it has a high hygroscopic property. For example, alkaline earth metals, alkali metals or oxides thereof, or inorganic porous materials can be used. These can be used alone or in combination of two or more. Among these, from the viewpoint of hygroscopicity and handling safety, alkaline earth metal or alkali metal oxides and inorganic porous materials are preferable, and calcium oxide and zeolite are particularly preferable.

The moisture absorption layer 6 may contain components other than the desiccant, and examples thereof include particles and rods made of Si, AlN, and C having high thermal conductivity.
As the shape of the moisture absorption layer 6, FIG. 1 is a hollow square, but is not particularly limited as long as it can absorb moisture transmitted from the outside, and depending on the arrangement of the light emitting region of the light emitting layer, a square, a rectangle, a circle, An oval shape or the like can be selected as appropriate. In addition, a hollow structure or a planar structure may be used as long as moisture from the outside can be blocked.

The lower limit of the thickness of the moisture absorption layer 6 is usually 0.1 μm or more, preferably 1 μm or more, more preferably 10 μm or more. The upper limit is usually 500 μm or less, preferably 200 μm or less, more preferably 100 μm or less.
(Protective layer)
The protective layer 7 blocks moisture and oxygen from the outside and also functions as a support when manufacturing the back member. The protective layer 7 is a flexible metal foil, and examples thereof include aluminum and copper.

The protective layer 7 is excellent in processing and cost reduction, and has an excellent barrier property to moisture and oxygen from the outside, is easy to bend when necessary, and has defects such as pinholes and cracks when heated or stressed. Is less likely to occur, aluminum foil is preferred.
The metal foil used for the protective layer 7 is a material satisfying the following formula (8).
F _0.2 <200 [N] (8)
(F _0.2 : Tensile force [N] when the protective layer metal foil cut to a width of 20 mm has a permanent elongation of 0.2% in the tensile test.)
Here, the tensile force F _0.2 in the present invention when the permanent elongation in the tensile test is 0.2% can be determined as follows. A test piece having a width of 20 mm and a length of 120 mm is prepared, applied to a tensile tester, and pulled in the longitudinal direction with both end portions 20 mm × 20 mm in the longitudinal direction being sandwiched. The elongation ((L (F) −Lo) / Lo × 100) [%] at this time is plotted on the horizontal axis and the tensile force F [N] is plotted on the vertical axis, and 0 on the elongation axis, which is the horizontal axis. A parallel line is drawn from the 2% point to the straight line portion at the beginning of the test, and the tensile force F _0.2 [N] indicated by the intersection of the parallel line and the plotted diagram is obtained. FIG. 2 shows how to obtain the tensile force _F0.2 .

  When the metal foil that is the protective layer 7 satisfies the formula (8), the metal foil has appropriate plasticity, and therefore, strain due to a difference in thermal expansion from the light-transmitting substrate and the sealing layer can be reduced. In addition, when there is a minute foreign substance on the substrate, there is a partition that partitions the pixel in the case of a display device, or there is an auxiliary electrode and / or an insulating film that covers the auxiliary electrode in the case of a large area substrate, Since these are protrusions, the flatness is lowered, but since the metal foil has an appropriate plasticity, the sealing member has good adhesion and is difficult to peel off.

The value of F _0.2 of the metal foil can be adjusted by changing the metal material and the post-processing method. For example, in the case of aluminum foil, towards the relatively pure pure aluminum, the value of F _0.2 is likely to be low, and performs annealing, hardening the value of better not done F _0.2 is low Cheap. By selecting an appropriate material and post-treatment method, it is possible to produce a metal foil having a value of F _0.2 of less than 200N.

The lower limit of the thickness of the protective layer 7 is usually 1 μm or more, preferably 10 μm or more, more preferably 40 μm or more. The upper limit is usually 500 μm or less, preferably 200 μm or less, more preferably 100 μm or less.
Regarding the relationship between the thickness of the protective layer 7 and the sealing layer 5 in the light emitting region, the thickness α of the protective layer 7 is preferably 0.3 times or more the thickness β of the sealing layer 5. When the thickness of the protective layer 7 is 0.3 times or more the thickness of the sealing layer 5, the heat generated in the organic electroluminescence element is efficiently transmitted to the protective layer 7 via the sealing layer 5, It is considered that heat can be efficiently radiated from the protective layer 7.

The reason is considered as follows. One of the causes of driving deterioration of the organic electroluminescence element is deterioration due to heat generation during driving. In order to suppress the influence of heat generation, it is necessary to efficiently dissipate the heat generated in the organic electroluminescence element. In order to dissipate heat, it is conceivable that heat is efficiently transmitted to the protective layer 7 which is the outermost layer of the back member, so that the protective layer 7 can easily receive heat. In order to efficiently transfer the heat from the organic electroluminescence element, it is necessary to lower the “thermal resistance per unit area” of the sealing layer 5. In order to make the protective layer 7 easily receive heat, it is necessary to increase the “heat capacity per unit area” of the protective layer 7. The “thermal resistance per unit area” of the sealing layer 5 is proportional to the thickness of the sealing layer 5, and the “heat capacity per unit area” of the protective layer 7 is proportional to the thickness of the protective layer 7. The smaller the “thermal resistance per unit area” of the sealing layer 5 is, the higher the thermal conductivity is, and the larger the “heat capacity per unit area” of the protective layer 7 is, the easier it is to store heat, so the heat generated in the organic electroluminescence element It is considered that the heat is efficiently transferred to the protective layer 7 and heat is easily accumulated in the protective layer 7, the temperature rise of the organic electroluminescence element is suppressed, and the element deterioration during driving is suppressed.

  In the case of forming the moisture absorption layer 6 in the present invention, the protective layer 7 has a recess so as to protrude from the surface facing the substrate toward the outer surface when the element is sealed. A surface that can accommodate the moisture absorption layer 6 and faces the substrate of the protective layer 7 in a state where the moisture absorption layer 6 is accommodated, and is a flat surface that is not a recess, and a surface that is not in contact with the protection layer 7 of the moisture absorption layer 6 Is preferably substantially flat. By adopting such a shape, the back member can be bonded to the substrate with good adhesion via the sealing layer 5.

The thickness of the organic EL light emitting device 10 is usually 0.1 to 5 mm, preferably 0.5 to 3 mm, and more preferably 1 to 2 mm.
As mentioned above, although this invention was demonstrated in detail based on the embodiment, this invention is not limited to the said embodiment. The present invention can be variously modified without departing from the gist thereof. For example, in the present embodiment, the organic electroluminescence element in which the anode 2, the organic functional layer 3, and the cathode 4 are sequentially laminated on the translucent substrate 1 has been described, but the cathode 4, An organic electroluminescence element in which the organic functional layer 3 and the anode 2 are sequentially laminated can also be used. In the embodiment of FIG. 1, the moisture absorbing layer 6 having a hollow rectangular shape has been described. However, as shown in FIG. 3, a constant interval (for example, an interval x) is provided along the outer periphery of the light emitting region of the light emitting layer. It can also be set as the planar shape which covers all the light emission areas of a light emitting layer, keeping it. The configuration of the organic EL light emitting device shown in FIG. 3 is the same as the configuration of the organic EL light emitting device shown in FIG. 1 except for the shape of the moisture absorption layer 6.

Next, the manufacturing method of the organic EL light emitting device of the present invention will be described.
The manufacturing method of the organic EL light-emitting device of the present invention includes an element forming step, a back member forming step, and a heat treatment step. Hereinafter, each step will be described.
(Element formation process)
An element formation process is a process of forming an organic electroluminescent element, and can employ | adopt a well-known method, For example, it can carry out with the following method. 4 (a) to 4 (c) are schematic cross-sectional views showing the manufacturing process of the organic electroluminescence element of the organic EL light emitting device. The manufacturing method of an organic electroluminescent element is demonstrated referring FIG. 4 (a)-(c).

First, the translucent substrate 1 is prepared. Next, as shown in FIG. 4A, the first electrode 2 is formed on the surface of the translucent substrate 1.
Formation of the 1st electrode 2 can be normally performed by sputtering method, a vacuum evaporation method, etc. In addition, when the first electrode 2 is formed by using fine metal particles such as silver, fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, conductive polymer fine powder, etc. The 1st electrode 2 can also be formed by disperse | distributing to a binder resin solution and apply | coating on the translucent board | substrate 1. FIG. Further, in the case of a conductive polymer, a thin film is directly formed on the light-transmitting substrate 1 by electrolytic polymerization, or the first electrode 2 is formed by applying a conductive polymer on the light-transmitting substrate 1. (Appl. Phys. Lett., 60, 2711, 1992).

Next, as shown in FIG. 4B, an organic functional layer 3 that forms at least a light emitting layer is formed on the first electrode 2.
A method for forming the organic functional layer 3 can be appropriately selected depending on the material. For example, a vacuum deposition method, a spin coating method, a dip coating method, a die coating method, a bar coating method, a blade coating method, a roll A coating method, a spray coating method, a capillary coating method, an ink jet method, a screen printing method, a gravure printing method, a flexographic printing method, and the like can be used.

Next, as shown in FIG. 4C, the second electrode 4 is formed on the organic functional layer 3.
As a method for forming the second electrode 4, a sputtering method, a vacuum evaporation method, or the like can be used.
(Back member forming process)
FIGS. 5A to 5D are schematic cross-sectional views illustrating the manufacturing process of the back member of the organic EL light emitting device. With reference to FIGS. 5A to 5D, a method for manufacturing the back member in the case of having the moisture absorption layer 6 will be described.

First, a flexible sheet to be a protective layer 7 as shown in FIG.
Next, as shown in FIG. 5B, the moisture absorbing layer 6 is formed on the surface of the protective layer 7 so as to surround the light emitting region of the light emitting layer, while maintaining a constant interval along the outer periphery of the light emitting region. Form into shape.
The method for forming the moisture absorbing layer 6 can be selected as appropriate depending on the material. For example, a dry film forming method such as a vacuum deposition method, insertion of a sheet-like moisture absorbing sheet, spin coating method, dip coating method, etc. , Wet coating methods such as die coating, bar coating, blade coating, roll coating, spray coating, capillary coating, ink jet, screen printing, gravure printing, flexographic printing, dispenser coating, etc. Can be used. Especially, insertion of a sheet-like moisture absorption sheet is preferable from a viewpoint of the simplicity of a process. Also, from the viewpoint of freedom of printing pattern and cost reduction, a wet film forming method is preferable, and printing methods such as a die coating method, a spray coating method, a screen printing method, a gravure printing method, a flexographic printing method, and a coating method using a dispenser are used. More preferably, screen printing and dispenser application are particularly preferably employed.

Next, as shown in FIG. 5B, the protective layer 7 in which the hygroscopic layers 6 are formed in a matrix is maintained at a constant interval along the outer periphery of the hygroscopic layer 6 as shown in FIG. 5C. Cut one piece at a time. In addition, you may perform this cutting after the process of forming the next sealing layer.
Next, as shown in FIG. 5D, the sealing layer 5 containing a thermoplastic resin is formed on the hygroscopic layer 6. In this case, the surface of the hygroscopic layer 6 is entirely covered with the sealing layer 5, and the sealing layer 5 is formed so that the end 5 a of the sealing layer 5 protrudes from the end 6 a of the hygroscopic layer 6.

As a method for forming the sealing layer 5, a roll coating method, a spin coating method, a screen printing method, a coating method such as spray coating, or a printing method may be used. From the viewpoint of workability, a sheet-like thermoplastic resin is used. A method of applying an adhesive is preferably employed.
Further, the back member of the organic EL light emitting device can be manufactured by the method shown in FIG. 6 instead of the method shown in FIG. 6A to 6D are schematic cross-sectional views illustrating other manufacturing steps of the back member of the organic EL light emitting device. The manufacturing method of the back member will be described with reference to FIGS.

A flexible sheet serving as the protective layer 7 as shown in FIG. 6A is prepared. As shown in FIG. 6B, the moisture absorption layer 6 is emitted on the surface of the flexible sheet serving as the protective layer 7. A flat shape is formed so as to cover the entire light emitting region of the light emitting layer while maintaining a constant interval along the outer periphery of the light emitting region of the layer. In addition, the formation method of the moisture absorption layer 6 is as having demonstrated in the above.
Next, as shown in FIG. 6 (c), the protective layer 7 is cut one by one along the outer periphery of the hygroscopic layer 6 while maintaining a constant interval, and then, as shown in FIG. 6 (d), the hygroscopic layer 6 A sealing layer 5 containing a thermoplastic resin is formed thereon. In addition, you may perform this cutting after the process of forming the following sealing layer 5. FIG. Moreover, it is good also as a single wafer process which forms the moisture absorption layer 6 in the flexible sheet | seat used as the protective layer 7 cut beforehand to the predetermined magnitude | size. Next, as illustrated in FIG. 6D, the sealing layer 5 including a thermoplastic resin is formed on the moisture absorption layer 6. The sealing layer 5 is formed in the same manner as in FIG.

  The flexible sheet to be the protective layer 7 is formed by forming a region where the moisture absorption layer 6 is formed into a concave shape in advance, or after forming the moisture absorption layer 6, the protection layer 7 is matched to the shape of the moisture absorption layer 6. Is preferably formed in a concave shape. The depth of the recess is preferably substantially equal to the thickness of the hygroscopic layer 6. The reason is that the surface on which the sealing layer 5 is formed coincides with the surface of the hygroscopic layer 6 and the surface of the flexible sheet that becomes the protective layer 7, so that the sealing layer 5 is formed uniformly. For this reason, when the element is sealed with the back member, the adhesiveness between the sealing layer 5 and the element is good, and entry of moisture and oxygen from the outside is prevented.

  The hygroscopic layer 6 is preferably formed in a planar shape that covers the entire light emitting region of the light emitting layer while maintaining a constant interval along the outer periphery of the light emitting region of the light emitting layer as shown in FIG. The reason is that even when a minute defect occurs in the protective layer 7 on the light emitting region for some reason, moisture is blocked by the moisture absorbing layer, thereby preventing deterioration of the element. In addition, the flexible sheet to be the protective layer 7 is molded into a concave shape in advance in the region where the moisture absorption layer 6 is formed, or after the moisture absorption layer 6 is formed, the protection layer is matched to the shape of the moisture absorption layer 6. In the case where 7 is formed in a concave shape, since the shape to be molded is not complicated, the flexible sheet serving as the protective layer 7 is not subjected to excessive stress, and defects such as pinholes and cracks are less likely to occur.

  An example of a method of forming the protective layer 7 in a concave shape in accordance with the shape of the moisture absorption layer 6 after forming the moisture absorption layer 6 will be described with reference to FIG. FIG. 8A shows a state in which the hygroscopic layer 6 is formed on the protective layer 7. As shown in FIG. 8B, the moisture absorption layer 6 is the bottom surface. In FIG. 8 (c), reference numeral 31 denotes a stage, which can have a flat surface and rigidity. For example, glass, metal such as stainless steel, ceramics, or the like can be used. In FIG. 8C, reference numeral 32 denotes a roller, and the surface of the hygroscopic layer 6 and the protective image 7 is matched with the flat surface of the stage 31 by pressing the portion of the protective layer 7 not provided with the hygroscopic layer 6 with the roller 32. Match. As a result, as shown in FIG. 8D, the sealing layer 5 can be formed on a flat surface in which the protective layer 7 and the hygroscopic layer 6 are substantially flush with each other. By forming the sealing layer 5 on a flat surface, it is preferable for the reasons that bubbles do not easily enter and there are no places where the adhesiveness is deteriorated due to deformation.

(Heat treatment process)
Next, using the organic electroluminescent element obtained by the above process and the back member, the electrode forming surface side of the organic electroluminescent element and the sealing layer forming surface side of the back member are connected to the end of the hygroscopic layer. Are laminated and pasted so that they protrude 0.4 mm or more from the light emitting region end of the light emitting layer along the horizontal direction.

  The heat treatment step is performed by heat-treating the organic electroluminescence element and the back member, which are laminated and bonded, while applying pressure from the organic electroluminescence element side and the back member side under normal pressure, reduced pressure, or high pressure atmosphere. Is called. For the heating, a thermal laminator, an oven, a hot plate, or the like can be used. The heating temperature is usually 200 ° C. or lower, preferably 170 ° C. or lower. The pressurization can be performed by a pressurizing means such as a laminator, a pressurizing roller or a press, or a high pressure atmosphere. Bonding under reduced pressure is preferable because air bubbles do not enter between the organic electroluminescence element and the back member, so that moisture permeability is reduced and peeling is difficult.

(Hot press processing)
It is particularly preferable that the heat treatment step includes a process (heat press process) of applying pressure while heating the region of the protective layer 7 outside the light emitting region end of the light emitting layer and where the hygroscopic agent 6 is not present. The heat press treatment is heating and pressurization so as to sandwich the surface of the organic electroluminescence element on which the back member is not overlapped and the surface of the protective layer 7 of the back member. By having this treatment, the thickness of the sealing layer 5 in the region outside the light emitting region end of the light emitting layer is reduced, and moisture and oxygen from the outside that permeate through the layer of the sealing layer 5 are preferably reduced. Further, since the thickness of the sealing layer 5 in the light emitting region is thicker than the thickness of the sealing layer 5 in the region outside the light emitting region end of the light emitting layer, moisture or oxygen that has permeated the sealing layer 5 from the outside. Is preferably diffused in the sealing layer 5 in the light emitting region, so that the probability that moisture reaches the hygroscopic layer is high, and the probability that moisture or oxygen reaches the light emitting layer and degrades the light emitting layer is preferable.

  In FIG. 9, an example which seals an organic electroluminescent element with a back member is shown. FIG. 9A shows a first electrode 2, an organic functional layer 3 formed on the first electrode 2, and a second electrode formed on the organic functional layer 3 on the translucent substrate 1. It is a figure of the state which piled up the back member which consists of the protective layer 7, the hygroscopic agent 6, and the sealing layer 5 on the organic electroluminescent element in which the electrode 4 was formed. In this state, the back member is adhered to such an extent that it cannot be peeled off, but may be easily peeled off under long-term use or in a hot and humid environment.

  Therefore, it is preferable that the heat treatment process includes a heat press process shown in FIG. In FIG. 9B, reference numeral 33 denotes a heating press member, which is a part of the member of the press device. Although not shown, the translucent substrate is disposed on the stage. For heating, the stage may be heated, the pressurizing member 33 may be heated, or heat press treatment may be performed in a high temperature environment. By heating and pressing only the region outside the light emitting region end by the heat press member 33, the adhesiveness is excellent, the back member is not peeled off even under long-term use or high temperature and high humidity, and the non-light emitting region is difficult to spread. An organic EL light-emitting device with excellent durability can be obtained.

  The heating temperature at the time of hot pressing is usually 50 ° C. or higher, preferably 60 ° C. or higher, usually 200 ° C. or lower, preferably 170 ° C. or lower. By heat-pressing in this temperature range, the organic functional layer 3 is not thermally deteriorated, and the sealing layer 5 can enhance the adhesion with the translucent substrate 1. Moreover, the protective layer 7 and the sealing layer 5 are deformed by the heating press, and the sealing layer 5 becomes thinner than the initial thickness. In FIG.9 (c), (beta) is the initial thickness of the sealing layer 5, and (gamma) is the thickness of the sealing layer 5 after a hot press. Since β> γ, moisture penetrating from the end portion and passing through the sealing layer 5 has a reduced cross-sectional area when reaching the light emitting region of the sealing layer 5, so that the moisture concentration decreases, and the organic functional layer It is preferable that 3 is hardly deteriorated. In FIG. 9C, the thickness of the organic electroluminescence element on the light emitting region (total of 2, 3, 4) is sufficiently smaller than the thickness of the sealing layer 5, and therefore the sealing layer 5 on the light emitting region. And the thickness β of the region where the hygroscopic layer 6 protrudes from the edge of the light emitting region are considered to be substantially the same.

  Further, the deformation amount of the sealing layer 5 by hot pressing ((1-γ / β) × 100 (%)) is usually 10% or more, preferably 20% or more of the thickness of the sealing layer 5. 90% or less, preferably 80% or less. Within this range, it is preferable that the sealing layer 5 is sufficiently adhered to the light-transmitting substrate 1 to reduce moisture permeability, hardly peel off, and does not break. Further, it is preferable that cracks and pinholes are not easily generated in the protective layer 7.

  Thus, the organic EL light-emitting device of the present invention can be manufactured. The organic EL light-emitting device of the present invention is, for example, a personal computer, a mobile phone, a digital still camera, a television, a viewfinder type, or a monitor direct view type. It can be applied as a display unit of a video tape recorder, a car navigation device, a pager, an electronic notebook, a calculator, a word processor, a workstation, a video phone, a POS terminal, and a device equipped with a touch panel.

[Organic EL display device]
The organic EL display device of the present invention is a display device using the organic electroluminescence light emitting device of the present invention described above. There is no restriction | limiting in particular about the model and structure of the organic electroluminescence display of this invention, It can assemble in accordance with a conventional method using the organic electroluminescent light-emitting device of this invention. For example, the organic EL display device of the present invention is produced by a method described in “Organic EL display” (Ohm, published on August 20, 2004, written by Shizushi Tokito, Chiba Adachi, and Hideyuki Murata). can do.

[Organic EL lighting]
The organic EL illumination of the present invention is illumination using the above-described organic electroluminescence light emitting device of the present invention. There is no restriction | limiting in particular about the model and structure of the organic EL illumination of this invention, It can produce in accordance with a conventional method using the organic electroluminescent light-emitting device of this invention.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples, and the present invention can be arbitrarily modified and implemented without departing from the gist thereof.
(Examples 1-5, Comparative Examples 1-4)
In the organic electroluminescence light emitting device of the present invention, a model sample having a structure in which the organic functional layer and the second electrode are omitted is prepared, and the metal foil satisfying the equation (8) is protected by measuring the adhesion strength of the protective layer. The effect of using the layer was verified. It is considered that the organic functional layer and the configuration of the second electrode have little influence on the adhesion strength of the protective layer.

<Preparation of model sample of Example 1 and evaluation of adhesion strength>
<< Production of ITO substrate >>
As a light-transmitting substrate, an indium tin oxide (ITO) transparent conductive film having a thickness of 70 nm formed on a 100 mm square glass plate as a first electrode (hereinafter referred to as an ITO substrate) was used. On this ITO substrate, an insulating film was formed in a pattern shown in FIG. 10 by screen printing. The shape of the insulating film is a rectangle with an outer diameter of 77 mm in length and 76.25 mm in width, and is basically a mouth shape whose outer periphery is surrounded by an insulating film with a width of 2.5 mm. Inside, four openings of 72 mm length and 17.25 mm width were arranged side by side with an insulating film having a width of 0.75 mm. The height of the insulating film was 30 nm.

<< Preparation of back member >>
As a protective layer, an aluminum foil having a value of F _0.2 of 27N made of a material that is completely annealed with aluminum having a purity of 99.30% or more is cut into a width of 84 mm and a length of 82 mm. A square region having a width of 80 mm and a length of 78 mm inside 2 mm from the outer periphery was press-molded with a mold so as to form a recess having a depth of 80 μm. A desiccant sheet (moist catch CCA manufactured by Kyodo Printing Co., Ltd., 80 μm thick) cut into a width of 80 mm and a length of 78 mm as a moisture absorption layer in a dry air atmosphere so as to fit in the concave portion of the aluminum foil is 120 ° C. And then bonded to an aluminum foil. The surface of the 2 mm region from the outer periphery of the aluminum foil and the surface of the desiccant were made substantially flush with each other, and a 40 μm-thick adhesive material was bonded thereon as a sealing layer to form a back member. .

<< Bonding of back member and ITO substrate >>
The back member was bonded to the center of the ITO substrate using a bonding machine.
Adhesion of the back member completely covers the insulating film formed on the ITO substrate, and the back member protrudes from the outer periphery of the insulating film by about 2 mm in the vertical direction and about 4 mm in the length direction. And pasted together. Thereafter, a hot press member was placed over the entire area of 2 mm width inside from the outer periphery of the back member, and was hot-pressed at 150 ° C. and 10 MPa with a press machine to produce a model sample of Example 1.

<< High temperature and high humidity storage test >>
When the model sample of Example 1 was put into a constant temperature and humidity chamber of 60 ° C. and 90% RH, taken out after storage for 500 hours, an area 2 mm wide inside from the outer periphery was observed, and the adhesion state of the aluminum foil and the ITO substrate was observed. The aluminum foil and the ITO substrate were not peeled off at all.
<Production of model samples of Examples 2 to 5 and Comparative Examples 1 to 4 and evaluation of adhesion strength>
In Examples 2 to 5 and Comparative Examples 1 to 4, except that the material and processing of the aluminum foil used for the protective layer were changed, model samples were prepared in the same manner as in Example 1, and the adhesion strength was evaluated. (Comparative Example 1 used a stainless steel foil instead of an aluminum foil.) The aluminum foil material, post-treatment method, thickness and F _0.2 values used in each Example and Comparative Example, and adhesion strength The evaluation results are summarized in Table 1. The value of F _0.2 was evaluated by the test method as described above.

In Table 1, the material of the aluminum foil and the meanings of the symbols for the post treatment are as follows.
1N30: Pure aluminum with a purity of 99.30% or more 1050: Pure aluminum with a purity of 99.50% or more 8021: Aluminum alloy with addition of iron 3004: Aluminum alloy with addition of manganese and magnesium 1100: Aluminum alloy with addition of copper SUS: Stainless steel alloy O: Completely annealed to the softest state H: Work hardened H22, H24: Work annealed moderately after work hardening (H24 has higher tensile strength than H22 Shows what was processed.)
Regarding the evaluation results of the adhesion strength in Table 1, after storing in a constant temperature and humidity chamber at 60 ° C. and 90% RH for 500 hours, an area 2 mm wide inside from the outer periphery is observed, and the aluminum foil and the ITO substrate are half of the above area. The case where it peeled above was described as x, and the others were described as ◯.

By changing the material and post-aluminum _foil, which can change the value of _{F 0.2} in the range of _27N～260N, by less 200N value of _{F 0.2,} the adhesion strength It can be seen that an organic electroluminescence light emitting device excellent in the above can be realized.
(Example 6)
The organic EL light emitting device shown in FIG. 1 was manufactured by the following method.

First, an organic electroluminescence device having a 2 mm square light emitting region was manufactured by the procedure shown in FIG.
<Formation of hole injection layer on ITO substrate>
As an ITO substrate, an indium tin oxide (ITO) transparent conductive film (anode 2) having a thickness of 70 nm is formed on a glass substrate having a length of 3.75 cm, a width of 2.5 cm, and a thickness of 0.7 mm. It was.

  Next, a polymer compound (PB-1, weight average molecular weight: 52000, number average molecular weight: 32500) having a repeating structure represented by the following formula (6), and 4-isopropyl-4'-methyldiphenyliodonium tetrakis (pentafluorophenyl) ) Borate was mixed at a weight ratio of 100: 20, and a composition was prepared by dissolving in ethyl benzoate so that the concentration of the mixture was 2.0% by weight. This composition was spin-coated on the ITO substrate in an air atmosphere in two stages of spinner rotation speed of 500 rpm for 2 seconds and further 1500 rpm for 30 seconds. Then, the 30-nm-thick hole injection layer was formed by heating at 230 degreeC for 15 minutes.

<Formation of hole transport layer>
Next, as the hole transport layer, 4,4′-bis [N- (9-phenanthryl) -N-phenyl-amino] biphenyl represented by the following formula (7) is manufactured by a vacuum deposition method so as to have a film thickness of 40 nm. Filmed.

<Formation of light emitting layer>
Next, tris (8-hydroxyquinolinate) aluminum (Alq3) was formed as a light emitting layer by a vacuum deposition method so as to have a film thickness of 60 nm.
<Electron injection layer>
Next, lithium fluoride (LiF) was deposited on the light emitting layer by a vacuum deposition method so as to have a film thickness of 0.5 nm to form an electron injection layer. The organic functional layer 3 was formed from the hole injection layer to the electron injection layer.

<Formation of cathode>
Next, aluminum is deposited by vacuum deposition so that the film thickness is 80 nm, and the cathode 4
Formed.
Next, a back member was manufactured according to the procedure shown in FIG.
<Formation of moisture absorption layer>
An aluminum foil having a thickness of 40 μm was cut into a 100 mm square as a metal foil serving as a protective layer. Dry Paste-S1 (manufactured by SaesGetters) with calcium oxide as the main agent as a desiccant, on a cut aluminum foil in an air atmosphere by a screen printer, a 60 mm thick, 3 mm wide, 16 mm side hollow square moisture absorption A layer was formed. Immediately after printing, it moved under a nitrogen atmosphere and baked on a hot plate at 200 ° C. for 30 minutes. The aluminum foil was cut into 23 mm square so that the hollow square moisture absorption layer was in the center.

The aluminum foil used at this time was cut into a width of 20 mm and a length of 120 mm, and both ends in the longitudinal direction were sandwiched by 20 mm with a tensile tester, and F _0.2 , that is, the permanent elongation in the tensile test was 0.2%. When the tensile force [N] was measured, it was 34 [N].
<Formation of sealing layer>
A 25 μm-thick thermoplastic sheet adhesive (made by JTY-0806, 3M) sandwiched between two PET films is cut into 23 mm square, and then the PET film on one side is peeled off to cover the entire surface of the moisture absorbing layer. And three thermoplastic sheet adhesives (75μm) are stacked and pasted on aluminum foil so that the edge of the sealing layer protrudes 3.5mm from the edge of the hygroscopic layer along the horizontal direction. A layer was formed. In order to make it adhere so that air may not enter between an aluminum foil and a moisture absorption layer, and a sealing layer, the sheet-like adhesive was roller press-bonded on the PET film on a 100 degreeC hotplate.

<Lamination of organic electroluminescence element and back member>
The opposite PET film from which the PET film was peeled off is peeled off from the end of the sealing layer, the adhesive surface of the sealing layer covers the light emitting layer of the organic electroluminescence element, and the end of the moisture absorbing layer emits light along the horizontal direction. It stuck so that 4 mm might protrude from the light emission area | region edge part of a layer. Place the glass side of the organic electroluminescence element on a hot plate at 100 ° C., press the aluminum foil of the back member with a roller, and then, outside the light emitting region of the back member, the region where the moisture absorption layer is not formed, The organic EL light emitting device shown in FIG. 1 was obtained by applying pressure with a roller. This organic EL light-emitting device is surrounded by a hollow rectangular moisture-absorbing layer while maintaining a constant interval along the outer periphery of the light-emitting region of the light-emitting layer.

(Test results)
The organic EL light-emitting device obtained in Example 6 was subjected to a storage test for 2500 hours in a constant temperature and humidity chamber at 85 ° C. and 85% RH, and the adhesion strength was evaluated in the same manner as in Example 1. The result was as follows: It was “◯”, and no abnormality was observed on the light emitting surface even during light emission after the storage test.

DESCRIPTION OF SYMBOLS 1 Translucent board | substrate 2 1st electrode 2a Extraction electrode 3 of 2nd electrode Organic functional layer 3a Light emission area | region edge part 4 of the light emitting layer which comprises the organic functional layer 3 2nd electrode 5 Sealing layer 5a Sealing layer 5 end 6 hygroscopic layer 6a hygroscopic layer 6 end 7 protective layer 9
DESCRIPTION OF SYMBOLS 10 Organic EL light-emitting device 15 Adhesive 16 Desiccant 17 Sealing can 20 Organic EL light-emitting device 30 Organic EL light-emitting device 31 Stage 32 Roller 33 Heating press member x From the light emission area edge part 3a of a light emitting layer to the edge part 6a of the moisture absorption layer 6 Horizontal distance to y Horizontal distance from the end portion 6a of the hygroscopic layer 6 to the end portion 5a of the sealing layer 5 α thickness of the protective layer β initial thickness γ of the sealing layer 5 peripheral portion heating and pressing treatment The thickness of the subsequent sealing layer 5

Claims (13)

A translucent substrate;
A first electrode formed on the translucent substrate;
An organic functional layer formed on the first electrode and having at least a light emitting layer;
A second electrode formed on the organic functional layer;
A sealing layer including a thermoplastic resin formed so as to cover at least the surfaces of the first electrode, the second electrode, and the organic functional layer;
A protective layer formed on the sealing layer and having flexibility;
The organic electroluminescence light-emitting device, wherein the protective layer is a metal foil satisfying the following formula (8).
F _0.2 <200 [N] (8)
(F _0.2 : Tensile force [N] when the permanent elongation in the tensile test of the protective layer metal foil cut to a width of 20 mm is 0.2%.)   2. The organic electroluminescence light-emitting device according to claim 1, further comprising a moisture absorption layer including a desiccant formed between the protective layer and the sealing layer so as to surround a light emitting region of the light emitting layer.   The organic electroluminescence light emission according to claim 2, wherein an end of the moisture absorption layer protrudes 0.4 mm or more longer than an end of the light emitting region along a horizontal direction and is shorter than an end of the sealing layer. apparatus.   4. The organic electroluminescence light-emitting device according to claim 2, wherein a thickness of the sealing layer in a region where the moisture absorption layer is not formed is thinner than a thickness of the sealing layer in the light-emitting region.   The organic electroluminescence light-emitting device according to any one of claims 2 to 4, wherein a distance in a horizontal direction from an end of the hygroscopic layer to an end of the sealing layer is 0.1 mm or more.   6. The organic electroluminescence light-emitting device according to claim 2, wherein the moisture absorption layer includes at least one selected from alkaline earth metals, alkali metals and oxides thereof, and inorganic porous materials.   The organic electroluminescence light-emitting device according to claim 2, wherein the moisture absorption layer has a thickness of 0.1 μm or more and 500 μm or less.   The organic electroluminescent light-emitting device according to claim 1, wherein a thickness of the protective layer on the light emitting region is 0.3 times or more a thickness of the sealing layer on the light emitting region.   The organic electroluminescence light-emitting device according to claim 1, wherein the sealing layer has a thickness of 1 μm or more and 200 μm or less.   The organic electroluminescent light-emitting device according to claim 1, wherein the protective layer has a thickness of 1 μm or more and 200 μm or less.   The organic electroluminescence light-emitting device according to any one of claims 1 to 10, wherein the protective layer metal foil is an aluminum foil. An organic EL display device using the organic electroluminescence light-emitting device according to claim 1.   Organic EL illumination using the organic electroluminescent light emitting device according to any one of claims 1 to 11.

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