WO2011048956A1

WO2011048956A1 - Decorated light-emitting body and method for producing same

Info

Publication number: WO2011048956A1
Application number: PCT/JP2010/067641
Authority: WO
Inventors: 茂間野; 柏木　寛司
Original assignee: コニカミノルタホールディングス株式会社
Priority date: 2009-10-22
Filing date: 2010-10-07
Publication date: 2011-04-28
Also published as: JP5678891B2; JPWO2011048956A1; JP2015062206A

Abstract

Disclosed is a safe decorated light-emitting body which has high energy consumption efficiency, high luminance and excellent scratch resistance, while being free from heat generation. The decorated light-emitting body can be easily produced at low cost and is suitable for high-mix low-volume production. Specifically disclosed is a decorated light-emitting body which has a decoration layer on a substrate surface that is on the light extraction side of a surface emitting element, said decoration layer being formed from a curable ink. The decorated light-emitting body is characterized in that when the refractive index of the substrate is represented by n1 and the refractive index of the decoration layer that is formed from a curable ink is represented by n2, n1 and n2 satisfy the following relations (1), (2) and (3). (1) 1.4 ≤ n1 ≤ 1.9 (2) 1.4 ≤ n2 ≤ 1.9 (3) |n1 - n2| ≤ 0.2

Description

Decorative luminous body and method for producing the same

The present invention relates to a decorative light emitter, and more particularly to a decorative light emitter using an organic electroluminescence element.

An organic electroluminescence (organic EL) element has been attracting attention as a new surface light-emitting device, such as a color display, a lighting device by emitting white light, or a backlight of a liquid crystal device.

These organic EL elements are attracting attention as resource-saving and energy-saving devices because they can be driven at low voltage, do not generate heat, and have high luminous efficiency, and are attracting attention as new display devices because they are surface-emitting light sources. It is coming.

Recently, a technique is disclosed in which a decorative layer is provided on the surface of a plate-like inorganic EL element via an adhesive layer, and various decorations are applied to the decorative layer to use it as a display such as an interior (see Patent Document 1). ).

Looking at the technique described in Patent Document 1, various images can be displayed in various forms by forming an image on the decoration layer by ink jet printing or the like and using an EL element as a backlight. Multiple varieties or single item production is possible.

However, the inorganic EL element used here has low light emission luminance, and the decoration layer is adhered to the substrate via the adhesive layer, so that the light extraction efficiency to the outside is improved by reflection at the adhesive interface. It has been found that there are problems such as low brightness of the display and wasteful energy consumption.

JP 2008-293942A

An object of the present invention is to provide a decorative illuminator that is easily, inexpensively, suitable for a variety of products and a small amount of production, has high energy consumption efficiency, high brightness, does not generate heat, is safe, and has excellent scratch resistance. And to provide a method for its manufacture.

The above problem could be solved by the following configuration of the present invention.

1. In a decorative light-emitting body having a decorative layer formed of a curable ink on a substrate surface on the light extraction side of a surface light emitting device, the refractive index of the substrate is n1, and the refractive index of the decorative layer formed of the curable ink is A decorative illuminant characterized in that n1 and n2 satisfy the following relationships 1), 2) and 3) when the rate is n2.

1) 1.4 ≦ n1 ≦ 1.9
2) 1.4 ≦ n2 ≦ 1.9
3) | n1-n2 | ≦ 0.2
2. In the surface roughness of the substrate of the surface light emitting device, the center line average roughness Ra, the maximum height Ry, and the 10-point average height Rz are respectively expressed by the following formulas 4), 5), and 6): 2. The decorative illuminant according to 1 above.

4) 0.1 nm ≦ Ra ≦ 10 nm
5) 1.0 nm ≦ Ry ≦ 100 nm
6) 1.0 nm ≦ Rz ≦ 100 nm
3. 3. The decorative light emitter according to 1 or 2 above, wherein the curable ink is a thermosetting ink.

4. 3. The decorative light emitter according to 1 or 2, wherein the curable ink is a two-component curable ink.

5. 3. The decorative light emitter according to 1 or 2, wherein the curable ink is a photocurable ink.

6. 6. The decorative illuminant as described in 5 above, wherein the photocurable ink is a visible light curable ink.

7. 6. The decorative illuminant as described in 5 above, wherein the photocurable ink is an ultraviolet curable ink.

8. 8. The decorative illuminator according to any one of 1 to 7, wherein the decoration layer is formed by screen printing.

9. 8. The decorative light emitter according to any one of 1 to 7, wherein the decorative layer is formed by ink jet printing.

10. 10. The decorative light emitting device according to any one of 1 to 9, wherein the surface light emitting device is an organic EL device.

11. In the method for producing a decorative light emitter having a decorative layer formed by the step of forming a curable ink layer on the light extraction side substrate surface of the surface light emitting element, the step of irradiating the formed curable ink layer with ultraviolet rays, A method for producing a decorative luminescent material, comprising: a step of irradiating the surface of the curable ink layer with ultraviolet rays; and a step of energizing the surface light emitting element to emit light.

12 In the method for producing a decorative light emitter having a decorative layer formed by the step of forming a curable ink layer on the light extraction side substrate surface of the surface light emitting element, the step of irradiating the formed curable ink layer with ultraviolet rays, A method for producing a decorative luminescent material, wherein the ultraviolet irradiation in the step of irradiating ultraviolet rays simultaneously performs the following 1) and 2).
1) Irradiation from above the curable ink layer 2) Irradiation from the end face of the light extraction side substrate of the surface light emitting element

According to the present invention, it is possible to provide a decorative light emitting body that is easily and inexpensively adapted to a wide variety and a small amount of production, has high energy consumption efficiency, has high luminance, is safe, and has excellent scratch resistance.

It is sectional drawing which shows the formation process of the decoration light-emitting body of this invention. It is a block diagram of a decoration light emitter inspection device. 2 shows a decorative illuminant having a transmission image pattern formed according to the present invention. 1 shows a Japanese paper-like, wood-like or marble-like decorative luminescent material formed according to the present invention.

Hereinafter, the present invention, its components, and the best mode and mode for carrying out the present invention will be described in detail.

[About surface light emitting devices]
Examples of the surface light-emitting element that forms the decorative light-emitting body of the present invention include organic electroluminescence elements (hereinafter referred to as organic EL elements), plasma light-emitting elements, light-emitting diodes (LEDs), liquid crystal display elements, and the like. None, but preferably an organic EL element is used.

The surface light emitting device according to the present invention may be a single color, multicolor or white light emitting device.

In the present invention, a decorative layer is directly formed with a curable ink on the surface of the substrate on the light extraction side of the surface light emitting device, so that various combinations of light emission and display can be easily performed with high brightness. It is.

In the present invention, it is possible to use a method in which the surface light-emitting element emits light uniformly over the entire surface and, on the other hand, a method of driving and displaying the screen. When driving and displaying a screen, the driving method may be a simple matrix (passive matrix) method or an active matrix method.

The surface light emitting device used in the present invention is preferably an organic EL device.

When a white organic EL element is used as the surface light emitting element used in the present invention, patterning may be performed by a metal mask, an ink jet printing method, or the like when forming the organic EL element as necessary. In the case of patterning, only the electrode may be patterned, the electrode and the light emitting layer may be patterned, or the entire element layer may be patterned.

The substrate used in the surface light emitting device of the present invention may be any transparent substrate such as glass, plastic plate or plastic film, but is preferably a flexible plastic film.

The present invention relates to a decorative light emitter having a decorative layer formed of a curable ink on a substrate surface on the light extraction side of a surface light emitting device, wherein the refractive index of the substrate is n1, and is formed of the curable ink. When the refractive index of the decorated layer is n2, n1 and n2 satisfy the following relationships 1), 2), and 3).

1) 1.4 ≦ n1 ≦ 1.9
2) 1.4 ≦ n2 ≦ 1.9
3) | n1-n2 | ≦ 0.2
In the present invention, a substrate having a refractive index in a specific range of n1 is selected, a refractive index of a decoration layer formed by the curable ink of n2 is selected in a range close to the refractive index of the substrate, and the refractive index of It has been found that by setting the difference within a specific range, internal reflection can be reduced and light extraction efficiency can be increased.

Further, the refractive index relationship is preferably n1 ≧ n2, and more preferably n1-n2 ≦ 0.1.

Further, in the surface roughness of the substrate of the surface light emitting device, the center line average roughness Ra, the maximum height Ry, and the 10-point average height Rz are represented by the following equations 4), 5), and 6), respectively. Features.

4) 0.1 nm ≦ Ra ≦ 10 nm
5) 1.0 nm ≦ Ry ≦ 100 nm
6) 1.0 nm ≦ Rz ≦ 100 nm
The surface roughness of the substrate may cause variations in luminance of the surface light emitters formed on the substrate and cause failures, while the durability of the decorative layer formed on the opposite surface From these relationships, by setting these values within a specific range, it was possible to improve the durability when used as a decorative light emitter.

Hereinafter, an organic EL element using a plastic film substrate will be described as a representative example of a surface light emitting element preferably used in the present invention.

[Basic structure of organic EL element]
Specific examples of the basic layer structure of the organic EL element preferably used in the present invention are shown below.
(I) substrate / anode / light-emitting layer / electron transport layer / cathode (ii) substrate / anode / hole transport layer / light-emitting layer / electron transport layer / cathode (iii) substrate / anode / hole transport layer / light-emitting layer / Hole blocking layer / electron transport layer / cathode (iv) substrate / anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) substrate / anode / anode buffer layer / Hole transport layer / light-emitting layer / hole-blocking layer / electron transport layer / cathode buffer layer / cathode Here, the light-emitting layer may contain two or more kinds of light-emitting materials having different emission colors, and the same color. The light emitting layer may be a single layer or may form a light emitting layer unit composed of a plurality of light emitting layers. The hole transport layer also includes a hole injection layer and an electron blocking layer.

(Substrate: Base material)
Although it does not specifically limit as a board | substrate (henceforth a base material, a base | substrate, a base | substrate, a support substrate, a support body etc.) used for the surface emitting element which concerns on this invention, Preferably it is a flexible transparent substrate or a glass substrate.

As the glass substrate, alkali-free glass, blue plate glass, quartz or the like is used. However, depending on the purpose, a metal film such as metal, stainless steel foil, Al foil or the like, quartz or the like can be used as the substrate.

Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate (CAP), Cellulose esters such as cellulose acetate phthalate and cellulose nitrate or their derivatives, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide, polyether Sulfone (PES), polyphenylene sulfide, polysulfones, polyester Examples include cycloolefin resins such as terimide, polyether ketone imide, polyamide, fluororesin, nylon, polymethyl methacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Appel (trade name, manufactured by Mitsui Chemicals). It is done.

Among these, polyesters such as polyethylene terephthalate and polyethylene naphthalate are preferable in terms of transparency, durability, and cost.

An inorganic or organic film or a hybrid film of both may be formed on the surface of the resin film, and the water vapor permeability measured by a method in accordance with JIS K 7129-1992 (40 ° C., 90% RH) Is preferably a barrier film of 0.01 g / m ² · day · atm or less, and further has an oxygen permeability (20 ° C., 100% RH) of 10 measured by a method according to JIS K 7126-1992. ⁻³ g / m ² / day or less and a water vapor transmission rate of 10 ⁻³ g / m ² / day or less are preferable, and both the water vapor transmission rate and the oxygen transmission rate are 10 ^−5. It is further more preferable that it is below g / m < ² > / day.

The material for forming the barrier film may be any material that has a function of suppressing the intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Furthermore, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and layers made of organic materials. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.

The method for forming the barrier film is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, ion plating, plasma polymerization, atmospheric pressure plasma polymerization A plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used, but an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.

When a glass substrate, metal, metal foil or the like is used, it has sufficient barrier properties such as water and oxygen by itself. do not need.

(electrode)
The organic EL element has at least a first electrode and a second electrode. Usually, one is an anode and the other is a cathode. The preferred anode and cathode configurations are described below.

<anode>
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such electrode substances include metals such as Au, and conductive light-transmitting materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO. Alternatively, a material such as IDIXO (In ₂ O ₃ —ZnO) that can form an amorphous light-transmitting conductive film may be used. For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when the pattern accuracy is not required (about 100 μm or more) ), A pattern may be formed through a mask having a desired shape when the electrode material is deposited or sputtered. Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film forming methods, such as a printing system and a coating system, can also be used. The sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.

<cathode>
On the other hand, as the cathode, a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like.

Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 to 200 nm.

In addition, in order to transmit the emitted light, either the anode or the cathode of the organic EL element is configured to be light transmissive.

(Light emitting layer)
The light-emitting layer is a layer that emits light by recombination of electrons and holes injected from the electrode, the electron transport layer, or the hole transport layer, and the light-emitting portion is the light-emitting layer even in the light-emitting layer. It may be an interface with an adjacent layer.

The structure of the light emitting layer is not particularly limited.

Also, there may be a plurality of layers having the same emission spectrum or emission maximum wavelength.

It is preferable to have a non-light emitting intermediate layer between each light emitting layer.

The total film thickness of the light emitting layer is preferably in the range of 1 to 100 nm, and more preferably 30 nm or less because a lower driving voltage can be obtained. Note that the total film thickness of the light emitting layer is a film thickness including the intermediate layer when a non-light emitting intermediate layer exists between the light emitting layers.

The film thickness of each light emitting layer is preferably adjusted in the range of 1 to 50 nm, more preferably in the range of 1 to 20 nm. There is no particular limitation on the relationship between the film thicknesses of the blue, green and red light emitting layers.

For the production of the light-emitting layer, a light-emitting material (also referred to as a light-emitting dopant) or a light-emitting host compound (also referred to as a host compound), which will be described later, is used, for example, a vacuum deposition method, a spin coating method, a casting method, an LB method, an inkjet method, or the like. The film can be formed by the thinning method.

A plurality of light emitting dopants may be mixed in each light emitting layer, and a phosphorescent light emitting dopant and a fluorescent light emitting dopant may be mixed and used in the same light emitting layer.

It is preferable that the light-emitting layer contains a light-emitting host compound and a light-emitting dopant and emits light from light-emitting dopan.

<Luminescent host compound>
As the light-emitting host compound contained in the light-emitting layer of the organic EL device, a compound having a phosphorescence quantum yield of phosphorescence emission at room temperature (25 ° C.) of less than 0.1 is preferable. More preferably, the phosphorescence quantum yield is less than 0.01. Moreover, it is preferable that the volume ratio in the layer is 50% or more among the compounds contained in a light emitting layer.

As the host compound, known host compounds may be used alone or in combination of two or more. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient. Moreover, it becomes possible to mix different light emission by using multiple types of luminescent material mentioned later, and can thereby obtain arbitrary luminescent colors.

The host compound may be a conventionally known low molecular compound, a high molecular compound having a repeating unit, or a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (polymerizable light emitting host).

As the luminescent host compound used in the organic EL element, it is preferable to use a low molecular compound. Here, the low molecular weight compound represents a compound having a molecular weight of 10,000 or less, preferably a compound having a molecular weight in the range of 100 to 10,000, and more preferably a compound in the range of 100 to 2000.

As the known host compound, a compound that has a hole transport ability and an electron transport ability, prevents the emission of light from being long-wavelength, and has a high Tg (glass transition point) is preferable. Here, the glass transition point (Tg) is a value determined by a method based on JIS-K-7121 using DSC (Differential Scanning Colorimetry).

Specific examples of known host compounds include compounds described in the following documents. For example, Japanese Patent Application Laid-Open Nos. 2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860 Gazette, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645, 2002-338579 No. 2002-105445, No. 2002-343568, No. 2002-141173, No. 2002-352957, No. 2002-203683, No. 2002-363227, No. 2002-231453. No. 2003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060. No. 2002-302516, No. 2002-305083, No. 2002-305084, No. 2002-308837, and the like.

(Luminescent dopant)
Next, the light emitting dopant will be described.

As the light-emitting dopant, a fluorescent compound (also referred to as a fluorescent compound) or a phosphorescent material (also referred to as a phosphorescent light-emitting material, a phosphorescent compound, or a phosphorescent compound) can be used. From the viewpoint of obtaining a high organic EL element, the light-emitting dopant used in the light-emitting layer or light-emitting unit of the organic EL element (sometimes simply referred to as a light-emitting material) contains the above-mentioned host compound and at the same time a phosphorescent dopant. It is preferable to contain.

The phosphorescent dopant will be described.

A phosphorescent dopant is a compound in which light emission from an excited triplet is observed, specifically, a compound that emits phosphorescence at room temperature (25 ° C.), and a phosphorescence quantum yield of 0.01 or more at 25 ° C. The preferred phosphorescence quantum yield is 0.1 or more.

The above phosphorescent quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. Although the phosphorescence quantum yield in a solution can be measured using various solvents, when using a phosphorescent dopant in the present invention, the above phosphorescence quantum yield (0.01 or more) is achieved in any solvent. Just do it.

There are two types of light emission of phosphorescent dopants in principle. One is the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the host compound, and this energy is transferred to the phosphorescent dopant. Energy transfer type to obtain light emission from the phosphorescent dopant, another is that the phosphorescent dopant becomes a carrier trap, carrier recombination occurs on the phosphorescent dopant, and light emission from the phosphorescent dopant is obtained Although it is a carrier trap type, in any case, it is a condition that the excited state energy of the phosphorescent dopant is lower than the excited state energy of the host compound.

The phosphorescent dopant can be appropriately selected from known ones used in the light emitting layer of the organic EL device, and is preferably a complex compound containing a group 8-10 metal in the periodic table of elements. More preferably, an iridium compound, an osmium compound, a platinum compound (platinum complex compound), or a rare earth complex, and most preferably an iridium compound.

As the dopant compound used in the organic EL element, it is preferable to use a low molecular compound. Here, the low molecular weight compound represents a compound having a molecular weight of 10,000 or less, preferably a compound having a molecular weight in the range of 100 to 10,000, and more preferably a compound in the range of 100 to 2000.

Specific examples of compounds used as phosphorescent dopants are shown below. These compounds are described, for example, in Inorg. Chem. 40, 1704 to 1711, and the like.

Fluorescent light emitters can also be used for the organic EL elements. Representative examples of fluorescent emitters (fluorescent dopants) include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, and pyrylium dyes. Examples thereof include dyes, perylene dyes, stilbene dyes, polythiophene dyes, and rare earth complex phosphors.

Conventionally known dopants can also be used. For example, WO 00/70655 pamphlet, JP 2002-280178 A, 2001-181616, 2002-280179, 2001-181617. Gazette, 2002-280180 gazette, 2001-247859 gazette, 2002-299060 gazette, 2001-313178 gazette, 2002-302671 gazette, 2001-345183 gazette, 2002-324679 gazette. International Publication No. 02/15645 pamphlet, Japanese Patent Application Laid-Open No. 2002-332291, Japanese Patent Application Publication No. 2002-50484, Japanese Patent Application Publication No. 2002-332292, Japanese Patent Application Publication No. 2002-83684, Japanese Patent Application Publication No. 2002-540572, Japanese Patent Application Laid-Open No. 2002-200572. No. 117978, No. 2002-338588, No. 2002-170684, No. 2002-352960, Pamphlet of International Publication No. 01/93642, Japanese Unexamined Patent Publication No. 2002-50483, No. 2002-1000047. 2002-173674, 2002-359082, 2002-17584, 2002-363552, 2002-184582, 2003-7469, JP 2002-525808, JP 2003-7471, JP 2002-525833, JP-A 2003-31366, 2002-226495, 2002-234894, 2002-233506, 2002-241751 2001-319779, 2001-319780, 2002-62824, 2002-1000047, 2002-203679, 2002-343572, 2002-203678, etc. Is mentioned.

Two or more kinds of light emitting materials may be contained in one light emitting layer, and the concentration ratio of the light emitting materials in the light emitting layer may be changed in the thickness direction of the light emitting layer.

(Middle layer)
It is also preferable to provide a non-light emitting intermediate layer (also referred to as an undoped region) between the light emitting layers.

Here, the “non-light emitting intermediate layer” is a layer provided between the light emitting layers when having a plurality of light emitting layers.

The film thickness of the non-light emitting intermediate layer is preferably in the range of 1 to 20 nm, and more preferably in the range of 3 to 10 nm to suppress interaction such as energy transfer between adjacent light emitting layers, and This is preferable because a large load is not applied to the voltage characteristics.

The material used for the non-light emitting intermediate layer may be the same as or different from the host compound of the light emitting layer, but may be the same as the host material of at least one of the adjacent light emitting layers. preferable.

The non-light-emitting intermediate layer may contain a non-light-emitting layer, a compound common to each light-emitting layer (for example, a host compound), and each common host material (where a common host material is used) In the case where the physicochemical characteristics such as phosphorescence emission energy and glass transition point are the same, or the molecular structure of the host compound is the same, etc.) The injection barrier is reduced, and it is possible to obtain an effect that the injection balance of holes and electrons can be easily maintained even when the voltage (current) is changed. Furthermore, by using a host material having the same physical characteristics or the same molecular structure as that of the host compound contained in each light emitting layer in the undoped light emitting layer, device fabrication, which is a major problem in conventional organic EL device fabrication, is achieved. Complexity can also be eliminated.

When using an organic EL element, the host material is responsible for carrier transport, and therefore a material having carrier transport capability is preferable. Carrier mobility is used as a physical property representing carrier transport ability, but the carrier mobility of an organic material generally depends on the electric field strength. Since a material having a high electric field strength dependency easily breaks the balance between injection and transport of holes and electrons, it is preferable to use a material having a low electric field strength dependency of mobility for the intermediate layer material and the host material.

On the other hand, in order to optimally adjust the injection balance of holes and electrons, it is also preferable that the non-light emitting intermediate layer functions as a blocking layer described later, that is, a hole blocking layer and an electron blocking layer. It is done.

(Injection layer: electron injection layer, hole injection layer)
The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, it exists between the anode and the light emitting layer or the hole transport layer and between the cathode and the light emitting layer or the electron transport layer. May be.

An injection layer is a layer provided between an electrode and an organic layer in order to reduce drive voltage and improve light emission luminance. “Organic EL element and its forefront of industrialization (issued by NTT Corporation on November 30, 1998) 2), Chapter 2, “Electrode Materials” (pages 123 to 166) in detail, and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).

The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, copper phthalocyanine is used. Examples thereof include a phthalocyanine buffer layer represented by an oxide, an oxide buffer layer represented by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.

The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. . The buffer layer (injection layer) is preferably an extremely thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm although it depends on the material.

(Blocking layer: hole blocking layer, electron blocking layer)
The blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film as described above. For example, it is described in JP-A Nos. 11-204258 and 11-204359, and “Organic EL elements and their forefront of industrialization” (published by NTT Corporation on November 30, 1998). There is a hole blocking (hole blocking) layer.

In a broad sense, the hole blocking layer has a function of an electron transport layer and is composed of a hole blocking material having a function of transporting electrons and having a remarkably small ability to transport holes, while transporting electrons. By blocking holes, the recombination probability of electrons and holes can be improved. Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer as needed. The hole blocking layer is preferably provided adjacent to the light emitting layer.

On the other hand, the electron blocking layer, in a broad sense, has a function of a hole transport layer, and is made of a material having a function of transporting holes while having a remarkably small ability to transport electrons, while transporting holes. By blocking electrons, the probability of recombination of electrons and holes can be improved. Moreover, the structure of the positive hole transport layer mentioned later can be used as an electron blocking layer as needed. The film thickness of the hole blocking layer and the electron transport layer is preferably 3 to 100 nm, and more preferably 5 to 30 nm.

(Hole transport layer)
The hole transport layer is made of a hole transport material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer can be provided as a single layer or a plurality of layers.

The hole transport material has either hole injection or transport or electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

The above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.

Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ′, N′-tetraphenyl-4,4′-diaminophenyl; N, N′-diphenyl-N, N′— Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' Di (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino -(2-diphenylvinyl) benzene; 3-methoxy-4'-N, N-diphenylaminostilbenzene; N-phenylcarbazole, and also two described in US Pat. No. 5,061,569 Having a condensed aromatic ring of, for example, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-30 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 688 are linked in a starburst type ( MTDATA) and the like.

Further, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used. In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

Also, JP-A-11-251067, J. Org. Huang et. al. A so-called p-type hole transport material described in a book (Applied Physics Letters 80 (2002), p. 139) can also be used.

The hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. it can. The thickness of the hole transport layer is not particularly limited, but is usually about 5 nm to 5 μm, preferably 5 to 200 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

It is also possible to use a hole transport layer having a high p property doped with impurities. Examples thereof include JP-A-4-297076, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

(Electron transport layer)
The electron transport layer is made of a material having a function of transporting electrons, and in a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer. The electron transport layer can be provided as a single layer or a plurality of layers.

Conventionally, in the case of a single electron transport layer and a plurality of layers, an electron transport material (also serving as a hole blocking material) used for an electron transport layer adjacent to the light emitting layer on the cathode side is injected from the cathode. As long as it has a function of transferring electrons to the light-emitting layer, any material can be selected and used from among conventionally known compounds. For example, nitro-substituted fluorene derivatives, diphenylquinone derivatives Thiopyrandioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives and the like. Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be used as an electron transport material. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq ₃ ), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) Aluminum, tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and the central metals of these metal complexes are In, Mg Metal complexes replaced with Cu, Ca, Sn, Ga, or Pb can also be used as electron transport materials. In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material. Further, the distyrylpyrazine derivatives exemplified as the material of the light emitting layer can also be used as the electron transport material, and inorganic semiconductors such as n-type-Si and n-type-SiC can be used as well as the hole injection layer and the hole transport layer. It can be used as an electron transport material.

The electron transport layer can be formed by thinning the electron transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. The thickness of the electron transport layer is not particularly limited, but is usually about 5 nm to 5 μm, preferably 5 to 200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

It is also possible to use an electron transport layer having a high n property doped with impurities. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

It is preferable to use an electron transport layer having such a high n property because an element with lower power consumption can be manufactured.

[Method for producing organic EL element]
As an example of a method for producing an organic EL element, a method for producing an organic EL element comprising an anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode will be described.

First, a thin film made of a desired electrode material, for example, an anode material, is formed on a suitable support substrate by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 10 to 200 nm, thereby producing an anode. To do. Next, an organic compound thin film of a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, and an electron transport layer, which are organic EL element materials, is formed thereon.

As a method for thinning the organic compound thin film, there are a vapor deposition method, a wet process (spin coating method, casting method, ink jet method, printing method) and the like as described above. The method and the printing method are particularly preferable. Further, a different film forming method may be applied for each layer.

After applying these layers by a wet process, it is preferable to perform a heat treatment in order to remove the residual solvent.

The heating method may be a heater heating method (infrared heater, halogen heater, panel heater, etc. are placed on or under the film and heated by radiant heat), or zone heating method (heating in a zone where hot air is blown and adjusted to a predetermined temperature) ) A zone heating method is preferable from the viewpoint of uniformity. In the case of the zone heating method, for example, a thermostatic bath can be used. The thermostat may be in any form as long as it can heat-treat the coating film at a set temperature, for example, the entire thermostat may be heated with warm air set at a predetermined temperature. Alternatively, warm air may be blown onto the film, or the inside of the thermostatic chamber may be set to a desired temperature using a heater. The attachment position of such a heating device such as a heater may be attached to any position inside the thermostatic bath as long as the coating film can be uniformly heated. Regarding the temperature distribution inside the thermostatic chamber, the temperature may be increased from the entrance toward the exit, the temperature may be decreased, or the temperature increase and decrease may be repeated. Moreover, a preheating part may be provided before heating, and a cooling part may be provided after heating.

The heating temperature only needs to be a temperature at which the residual solvent can be removed, and is generally higher than the boiling point of the solvent used for coating. preferable. However, since it is necessary to avoid deterioration of the substrate and the organic layer formed by coating, the temperature has an upper limit and is selected depending on the system.

The heat treatment time is preferably 1 to 120 minutes, more preferably 5 to 60 minutes, and further preferably 10 to 30 minutes. By setting the heat treatment time to 1 minute or longer, the residual solvent can be sufficiently removed, and by setting the heat treatment time to 120 minutes or shorter, deterioration of the organic layer due to heating can be suppressed.

After these layers are formed, a thin film made of a cathode material is formed thereon by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably in the range of 50 to 200 nm, and a cathode is provided. Thus, a desired organic EL element can be obtained.

The production of this organic EL element can be produced in the order of the cathode, the electron injection layer, the electron transport layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode by reversing the production order. When a DC voltage is applied to the organic EL device thus obtained, light emission can be observed by applying a voltage of about 2 to 40 V with the positive polarity of the anode and the negative polarity of the cathode. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

An organic EL element generally emits light inside a layer having a refractive index higher than that of air (refractive index of about 1.6 to 2.1) and can only extract about 15 to 20% of the light generated in the light emitting layer. It has been said. This is because light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be extracted outside the device, or between the transparent electrode or light emitting layer and the transparent substrate. This is because the light is totally reflected between the light and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the direction of the element side surface.

As a method for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (for example, US Pat. No. 4,774,435). ), A method of improving the efficiency by giving the substrate a light condensing property (for example, JP-A-63-314795), a method of forming a reflective surface on the side surface of the element (for example, JP-A-1-220394) Gazette), a method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between the substrate and the light emitter (for example, Japanese Patent Application Laid-Open No. 62-172691), a substrate between the substrate and the light emitter. A method of introducing a flat layer having a lower refractive index than that (for example, Japanese Patent Laid-Open No. 2001-202827), a diffraction grating is provided between any of the substrate, the transparent electrode layer and the light emitting layer (including between the substrate and the outside). Method of forming There is 11-283751 JP), and the like.

In the present invention, by combining these means, it is possible to obtain an element having higher brightness or durability.

Extraction efficiency .eta.1 of light extracted to the air from the medium of refractive index n is usually represented by the formula of η1 = 1 / 2n ^2, becomes larger than the wavelength thickness is an optical medium n, the light extraction efficiency η2 Since η2 = 1− (n ² −1) ^1/2 / n, the lower the refractive index of the medium n, the higher the extraction efficiency to the outside. That is, when the thickness of the low refractive index medium is about the wavelength of light and the electromagnetic wave exuded by evanescent enters the substrate, the effect of the low refractive index layer is diminished.

Examples of the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.0 or more and 1.5 or less. Further, it is preferably 1.0 or more and 1.35 or less.

Also, the thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. Preferably, they are 1.0 micrometer or more and 2.0 mm or less.

The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency. This method uses the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction, such as first-order diffraction and second-order diffraction. Among them, light that cannot be emitted due to total reflection between layers, etc. is diffracted by introducing a diffraction grating into any layer or medium (in a transparent substrate or transparent electrode), and the light is emitted outside. I want to take it out.

It is desirable that the diffraction grating to be introduced has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only light traveling in a specific direction is diffracted. The light extraction efficiency does not increase so much. However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.

As described above, the position where the diffraction grating is introduced may be in any one of the layers or in the medium (in the transparent substrate or the transparent electrode), but is preferably in the vicinity of the organic light emitting layer where light is generated.

At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium. The arrangement of the diffraction grating is preferably two-dimensionally repeated such as a square lattice, a triangular lattice, or a honeycomb lattice.

The light emitting element is processed on the light extraction side of the support substrate so as to provide, for example, a microlens array-like structure or combined with a so-called condensing sheet, for example, a front direction with respect to the element light emitting surface. By condensing the light, the luminance in a specific direction can be increased.

As an example of the microlens array, a quadrangular pyramid having a side of 30 μm and an apex angle of 90 degrees is arranged two-dimensionally on the light extraction side of the substrate. One side is preferably 10 to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

As the condensing sheet, it is possible to use, for example, a sheet that has been put to practical use in an LED backlight of a liquid crystal display device. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used. As the shape of the prism sheet, for example, a triangle stripe having a vertex angle of 90 degrees and a pitch of 50 μm may be formed on the substrate, the vertex angle may be rounded, and the pitch may be changed randomly. Other shapes may be used.

Further, in order to control the light emission angle from the light emitting element, a light diffusing plate / film may be used in combination with the light collecting sheet, or a light diffusing function may be added to the decorative layer. For example, a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.

(Sealing substrate)
The sealing substrate seals the organic EL element and protects the element from a severe external environment such as temperature change, humidity, oxygen, and impact.

As the sealing substrate, various known gas barrier films on which a barrier film is formed can be used. For example, a known gas barrier film used for packaging materials, for example, a film in which silicon oxide or aluminum oxide is vapor-deposited on a resin (plastic) film, a dense ceramic layer, and a flexible impact relaxation polymer layer are alternately arranged. A gas barrier film or the like having a configuration laminated on can be used as a sealing substrate.

In particular, a metal foil laminated with a resin film (polymer film) cannot be used as a gas barrier film on the light extraction side, but it is a sealing base material that is low in cost and has low moisture permeability, and can extract light. When it is not intended (transparency is not required), it is preferable as a sealing substrate.

"Metal foil" refers to a metal foil or film formed by rolling or the like, unlike a metal thin film formed by sputtering or vapor deposition, or a conductive film formed from a fluid electrode material such as a conductive paste. .

As metal foil, there is no limitation in particular in the kind of metal, for example, copper (Cu) foil, aluminum (Al) foil, gold (Au) foil, brass foil, nickel (Ni) foil, titanium (Ti) foil, copper alloy Examples thereof include foil, stainless steel foil, tin (Sn) foil, and high nickel alloy foil. Among these various metal foils, a particularly preferred metal foil is an Al foil.

The thickness of the metal foil is preferably 5 nm to 50 μm from the viewpoint of barrier properties (moisture permeability, oxygen permeability) and cost.

As the resin film in the metal foil laminated with the resin film (polymer film), various materials described in the new development of functional packaging materials (Toray Research Center, Inc.) can be used. Resin, polypropylene resin, polyethylene terephthalate resin, polyamide resin, ethylene-vinyl alcohol copolymer resin, ethylene-vinyl acetate copolymer resin, acrylonitrile-butadiene copolymer resin, cellophane resin, vinylon resin, chloride Examples thereof include vinylidene resins. Resins such as polypropylene resins and nylon resins may be stretched and further coated with a vinylidene chloride resin. In addition, a polyethylene resin having a low density or a high density can be used.

Among the above polymer materials, nylon (Ny), nylon (KNy) coated with vinylidene chloride (PVDC), unstretched polypropylene (CPP), stretched polypropylene (OPP), polypropylene coated with PVDC (KOP), polyethylene Use terephthalate (PET), PVDC-coated cellophane (KPT), polyethylene-vinyl alcohol copolymer (Eval), low density polyethylene (LDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE) Is preferred. As these thermoplastic films, a multilayer film formed by coextrusion with a different film, a multilayer film laminated by changing the stretching angle, and the like can be used as needed. Furthermore, it is naturally possible to combine the density and molecular weight distribution of the film used to obtain the required physical properties of the packaging material.

The thickness of the resin film (polymer film) cannot be generally specified, but is preferably 3 to 400 μm, more preferably 10 to 200 μm, and even more preferably 10 to 50 μm.

As a method for coating (laminating) a polymer film on one side of a metal foil, a generally used laminating machine can be used.

A dry laminating method, a hot melt lamination method and an extrusion laminating method can be used, but a dry laminating method is preferred.

As the adhesive, polyurethane-based, polyester-based, epoxy-based, acrylic-based adhesives and the like can be used. You may use a hardening | curing agent together as needed.

A film in which one side of a metal foil is coated with a resin film (polymer film) is commercially available for packaging materials. For example, a dry laminate film having a configuration of adhesive layer / aluminum film 9 μm / polyethylene terephthalate (PET) 38 μm can be obtained, and the cathode side of the organic EL element can be sealed using this.

Also, as the sealing substrate (film), a ceramic film is formed on the metal foil on the opposite side of the resin film (polymer film) of the film coated with a resin film (polymer film) on one side of the metal foil. It is also preferable to use them.

As will be described later, as a method for sealing the two films, for example, a method of laminating a commonly used impulse sealer heat-fusible resin film (layer), fusing with an impulse sealer, and sealing is preferable. .

In the present invention, the gas barrier properties of the sealing substrate (film) are preferably those having an oxygen permeability of 10 ⁻³ g / m ² / day or less and a water vapor permeability of 10 ⁻³ g / m ² / day or less. . The water vapor permeability and oxygen permeability are more preferably 10 ⁻⁵ g / m ² / day or less.

(Sealing substrate adhesive)
Examples of the adhesive for adhering the sealing substrate include a thermosetting adhesive having a reactive vinyl group such as an acrylic acid oligomer or a methacrylic acid oligomer. As commercial products, ThreeBond 1152, 1153 and the like can be used.

In addition, since an organic EL element may be deteriorated by heat treatment, a thermosetting adhesive that cures in about 1 hour at a temperature equal to or higher than the Tg of the sealing substrate and lower than the Tg of the flexible transparent substrate. preferable. For example, when polyethylene naphthalate (Tg, 155 ° C.) is used as the flexible transparent substrate and polyethylene terephthalate (Tg, 110 ° C.) is used as the sealing substrate, an epoxy thermosetting adhesive with a curing condition of 120 ° C. for 1 hour is used. Agents.

In addition, it is also preferable to coat the electrode and the organic layer on the outside of the electrode facing the support substrate with the organic layer interposed therebetween, and form an inorganic or organic layer in contact with the support substrate to form a sealing film. it can. In this case, the material for forming the film may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like may be used. it can. Furthermore, in order to improve the brittleness of the film, it is preferable to provide a laminated structure of these inorganic layers and layers made of organic materials. The method for forming these films is not particularly limited. For example, vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

In the gap between the sealing substrate and the display area of the organic EL element, an inert gas such as nitrogen or argon, or an inert liquid such as fluorinated hydrocarbon or silicon oil can be injected in the gas phase and liquid phase. preferable. A vacuum can also be used. Moreover, a hygroscopic compound can also be enclosed inside.

Examples of the hygroscopic compound include metal oxides (for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide) and sulfates (for example, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate). Etc.), metal halides (eg calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide etc.), perchloric acids (eg perchloric acid) Barium, magnesium perchlorate, and the like), and anhydrous salts are preferably used in sulfates, metal halides, and perchloric acids.

[Encapsulation of organic EL elements]
In the present invention, after forming a transparent conductive film on a substrate and further forming various functional layers constituting the organic EL element on the substrate, in the environment purged with an inert gas, The organic EL element can be sealed so as to cover the cathode surface.

As the inert gas, a rare gas such as He and Ar is preferably used in addition to N ₂ , but a rare gas in which He and Ar are mixed is also preferable, and the ratio of the inert gas in the gas is 90 to 99.99. It is preferably 9% by volume. Preservability is improved by sealing in an environment purged with an inert gas.

In sealing an organic EL element using a metal foil laminated with the resin film (polymer film), a ceramic film is formed on the metal foil instead of the laminated resin film surface. The ceramic film surface is preferably bonded to the cathode of the organic EL element.

As a bonding method, the dry laminating method is excellent in terms of workability. This method generally uses a curable adhesive layer of about 1.0 to 2.5 μm. Preferably, the amount of adhesive is preferably adjusted to 3 to 5 μm in terms of dry film thickness.

In addition, the method (hot melt laminating method) which melts a hot melt adhesive and coats an adhesive layer on a substrate, or a resin (LDPE, EVA, PP, etc.) melted at a high temperature is coated on the substrate by a die. A method (extrusion laminating method) or the like may also be used.

[Protective film, protective plate]
In order to increase the mechanical strength of the element, a protective film or a protective plate may be provided on the outer side of the sealing film on the side facing the support substrate with the organic layer interposed therebetween or on the sealing film. In particular, when the sealing is performed by the sealing film, the mechanical strength is not necessarily high, and thus it is preferable to provide such a protective film and a protective plate. As a material that can be used for this, the same glass plate, polymer plate / film, metal plate / film, etc. used for the sealing can be used, but the polymer film is light and thin. Is preferably used.

[About the decorative layer of the present invention]
The decorative layer of the present invention will be described.

The decorative layer of the present invention is formed using a curable ink.

As the curable ink, various curable inks such as actinic ray curable resin, thermosetting resin, and two-component curable resin can be used.

The actinic radiation curable resin is mainly composed of a resin that is cured through a crosslinking reaction or the like by irradiation with actinic rays such as ultraviolet rays, visible rays, and electron beams. As the actinic radiation curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and a decorative layer is formed by curing by irradiating actinic radiation such as ultraviolet rays, visible rays or electron beams. Is done. Typical examples of the actinic radiation curable resin include an ultraviolet curable resin, a visible light curable resin, and an electron beam curable resin.

As the ultraviolet curable resin, for example, an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, or an ultraviolet curable epoxy resin is preferable. Used.

UV curable acrylic urethane resins generally include 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter referred to as acrylate) in products obtained by reacting polyester polyols with isocyanate monomers or prepolymers. It is easily obtained by reacting an acrylate monomer having a hydroxyl group such as 2-hydroxypropyl acrylate. For example, those described in JP-A-59-151110 can be used. For example, a mixture of 100 parts of Unidic 17-806 (manufactured by DIC Corporation) and 1 part of Coronate L (manufactured by Nippon Polyurethane Corporation) is preferably used.

Examples of UV curable polyester acrylate resins include those that are easily formed by reacting polyester polyols with 2-hydroxyethyl acrylate and 2-hydroxy acrylate monomers, generally as disclosed in JP-A-59-151112. Can be used.

Specific examples of the ultraviolet curable epoxy acrylate resin include those produced by reacting epoxy acrylate with an oligomer, a reactive diluent and a photoinitiator added thereto, and reacting them. Those described in US Pat. No. 105738 can be used.

Specific examples of UV curable polyol acrylate resins include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol pentaacrylate, etc. Can be mentioned.

Specific examples of photoreaction initiators for these ultraviolet curable resins include benzoin and its derivatives, acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof. You may use with a photosensitizer. The photoinitiator can also be used as a photosensitizer. In addition, when using an epoxy acrylate photoinitiator, a sensitizer such as n-butylamine, triethylamine, or tri-n-butylphosphine can be used. The photoreaction initiator or photosensitizer used in the ultraviolet curable resin composition is 0.1 to 15 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the composition.

Examples of the resin monomer may include general monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, benzyl acrylate, cyclohexyl acrylate, vinyl acetate, and styrene as monomers having one unsaturated double bond. Monomers having two or more unsaturated double bonds include ethylene glycol diacrylate, propylene glycol diacrylate, divinylbenzene, 1,4-cyclohexane diacrylate, 1,4-cyclohexyldimethyl adiacrylate, and the above-mentioned trimethylolpropane. Examples thereof include triacrylate and pentaerythritol tetraacryl ester.

Commercially available UV curable resins that can be used in the present invention include Adekaoptomer KR / BY series: KR-400, KR-410, KR-550, KR-566, KR-567, BY-320B (Asahi Denka ( Co., Ltd.); Koeihard A-101-KK, A-101-WS, C-302, C-401-N, C-501, M-101, M-102, T-102, D-102, NS -101, FT-102Q8, MAG-1-P20, AG-106, M-101-C (Guangei Chemical Co., Ltd.); Seika Beam PHC2210 (S), PHC X-9 (K-3), PHC2213, DP -10, DP-20, DP-30, P1000, P1100, P1200, P1300, P1400, P1500, P1600, SCR900 (Daiichi Seika Kogyo Co., Ltd.) ); KRM7033, KRM7039, KRM7130, KRM7131, UVECRYL29201, UVECRYL29202 (manufactured by Daicel UCB); RC-5015, RC-5016, RC-5020, RC-5031, RC-5100, RC-5102, RC- 5120, RC-5122, RC-5152, RC-5171, RC-5180, RC-5181 (manufactured by DIC Corporation); 340 clear (manufactured by China Paint Co., Ltd.); Sunrad H-601, RC-750, RC-700, RC-600, RC-500, RC-611, RC-612 (manufactured by Sanyo Chemical Industries); SP -1509, SP-1507 (manufactured by Showa Polymer Co., Ltd.); RCC-15C (manufactured by Grace Japan Co., Ltd.), Aronix M-6100, M-8030, M-8060 (manufactured by Toagosei Co., Ltd.), DIC Corporation OP-38Z, OP-40, OP-40Z, OP-43, V-9510, V-9530, Sigma-Aldrich 640204, 640298, etc. can be appropriately selected and used.

Examples of specific compounds include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol pentaacrylate, and the like. .

The decorative layer made of these actinic ray curable resins can be applied by a known method such as a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater, or an ink jet method.

As a light source for curing the ultraviolet curable resin by a photo-curing reaction to form a decoration layer, any light source that generates ultraviolet light can be used without limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used. Irradiation conditions vary depending on each lamp, but the irradiation amount of active rays is preferably 5 to 150 mJ / cm ² , and particularly preferably 20 to 100 mJ / cm ² .

An organic solvent may be used for the UV curable resin layer composition coating solution. Examples of the organic solvent include hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol, cyclohexanol), ketones, and the like. It can be appropriately selected from a class of compounds (acetone, methyl ethyl ketone, methyl isobutyl ketone), esters (methyl acetate, ethyl acetate, methyl lactate), glycol ethers, and other organic solvents, or a mixture thereof can be used.

Examples of the visible light curable resin include Clear Luce (registered trademark) MA21, Benefix S105, STN30, and VX manufactured by Adel Co., Ltd.

Examples of the two-component curable resin include 9300 series HIPET ink manufactured by Jujo Chemical Co., Ltd., inks obtained by blending imide resins such as V-8000, 8001, 8002, and 8003 manufactured by DIC and epoxy resins. it can.

A decorative layer is formed on the substrate surface of the light emitting surface of the organic EL element, which is a surface light emitting element, using the curable ink described above.

As a method for forming the decoration layer, there are a spin coating method, a casting method, an ink jet method, a printing method, and the like, but an ink jet method and a printing method (screen printing, gravure printing, etc.) are particularly preferable from the viewpoint of excellent productivity.

The decorative layer is formed by curing the layer formed of the curable ink using light irradiation, heating, or both light irradiation and heating.

The heating method may be a heater heating method (infrared heater, halogen heater, panel heater, etc. are placed on or under the film and heated by radiant heat), or zone heating method (heating in a zone where hot air is blown and adjusted to a predetermined temperature) ) In the case of the zone heating method, for example, a thermostatic bath can be used. The thermostat may be in any form as long as it can heat-treat the coating film at a set temperature, for example, the entire thermostat may be heated with warm air set at a predetermined temperature. Alternatively, warm air may be blown onto the film, or the inside of the thermostatic chamber may be set to a desired temperature using a heater. The attachment position of such a heating device such as a heater may be attached to any position inside the thermostatic bath as long as the coating film can be uniformly heated. Regarding the temperature distribution inside the thermostatic chamber, the temperature may be increased from the entrance toward the exit, the temperature may be decreased, or the temperature increase and decrease may be repeated. Moreover, a preheating part may be provided before heating, and a cooling part may be provided after heating.

The heating temperature may be a curing temperature, and is preferably 100 ° C. or higher. However, since it is necessary to avoid deterioration of the substrate and the organic layer formed by coating, the temperature has an upper limit and is selected depending on the system.

The light irradiation may be a method of irradiating from the outside using a lamp that emits actinic rays. In the present invention, the surface light emitting element is made to emit light by energizing the surface light emitting element so that the light irradiation from the inside is also performed. The method to perform is a preferable method which can also irradiate the uncured portion where the light did not reach by light irradiation from the surface, and uniformize the curing.

The irradiation from the outside and the irradiation from the inside may be performed simultaneously or separately, and it is preferable to perform irradiation at the same time or partially overlapping.

In addition, the following 1) and 2) can be simultaneously performed in the step of irradiating the ultraviolet rays, so that it is possible to irradiate the uncured portion where the light has not reached by the light irradiation from the surface. This is a preferable method because it can be made uniform.
1) Irradiation from the curable ink layer 2) Irradiation from the end surface of the light extraction side substrate of the surface light emitting element In the curable ink, a colorant, a granular additive, an ultraviolet absorber, an antioxidant An additive such as an agent can be added to produce a desired ink.

[Use]
The decorative light-emitting body of the present invention can be used for various applications such as building materials, furniture, lighting, in-vehicle displays, signs, advertisements, and the like. As a building material, it is used for a wall material, a floor material, a tile, and the like, and when the wall material and the floor material itself emit light, it can be used as a wall lighting or a floor lighting, and can also be used as a display or a sign. Moreover, when using for furniture etc., it can design as a shining furniture, a shining partition, and a shining curtain, and can use it for home use or vehicle-mounted use. Moreover, it can be used as all kinds of lighting and displays using surface light emitting elements such as billboard advertisements and traffic lights.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these descriptions.

Example 1
<< Production of Decorative Light Emitter 101 (Invention) >>
<Production of gas barrier flexible film>
As a flexible film, an atmospheric pressure plasma discharge treatment apparatus having the structure described in JP-A-2004-68143 is formed on the entire surface of a polyethylene terephthalate film having a thickness of 100 μm (a film manufactured by Konica Minolta, hereinafter abbreviated as PET). The inorganic gas barrier film (thickness 500 nm) made of SiO _x (x is 2 or less) is continuously formed on the flexible film, and the oxygen permeability is 0.001 cm ³ / (m ² · 24 h · atm. ) A gas barrier flexible film having a water vapor permeability of 0.001 g / (m ² · 24 h) or less was prepared.

<Formation of first electrode layer>
A 120 nm thick ITO (indium tin oxide) film was formed on the prepared gas barrier flexible film by sputtering and patterned by photolithography to form a first electrode layer. The pattern was such that the light emission area was 50 mm × 50 mm.

<Formation of hole transport layer>
As a modification treatment of the surface of the first electrode layer of the gas barrier flexible film on which the prepared first electrode layer is formed, a low-pressure mercury lamp with a wavelength of 184.9 nm is used, an irradiation intensity of 15 mW / cm ² , and a distance of 10 mm. In addition, as a charge removal process, a process using a static eliminator with weak X-rays was performed. The hole transport layer forming coating liquid shown below was applied to the surface of the first electrode layer subjected to the above treatment by an extrusion coater, and then dried to form a hole transport layer. The coating liquid for forming the hole transport layer was applied so that the thickness after drying was 50 nm.

(Application conditions)
The coating process was performed in the atmosphere at 25 ° C. and a relative humidity of 50%.

(Preparation of coating solution for hole transport layer formation)
A solution prepared by diluting polyethylene dioxythiophene / polystyrene sulfonate (PEDOT / PSS, Baytron P AI 4083 manufactured by Bayer) with pure water at 65% and methanol at 5% was prepared as a coating solution for forming a hole transport layer.

(Drying and heat treatment conditions)
After applying the hole transport layer forming coating solution, the solvent is removed at a height of 100 mm toward the film forming surface, a discharge air velocity of 1 m / s, a wide air velocity distribution of 5%, and a temperature of 100 ° C., followed by heat treatment. The back surface heat transfer type heat treatment was performed at a temperature of 120 ° C. using an apparatus to form a hole transport layer.

<Formation of light emitting layer>
Subsequently, on the hole transport layer of the gas barrier flexible film formed up to the hole transport layer, the following white light emitting layer forming coating solution was applied by an extrusion coater, and then dried to form the light emitting layer. Formed. The white light emitting layer forming coating solution was applied so that the thickness after drying was 40 nm.

(Coating liquid for white light emitting layer formation)
Host material HA 1.0g, dopant material DA 100mg, dopant material DB 0.2mg, dopant material DC 0.2mg, dissolved in 100g toluene to form white light emitting layer It was prepared as a coating solution.

(Application conditions)
The coating process was performed in an atmosphere having a nitrogen gas concentration of 99% or more, a coating temperature of 25 ° C., and a coating speed of 1 m / min.

(Drying and heat treatment conditions)
After applying the white light emitting layer forming coating solution, the film was blown onto the film forming surface and the solvent was removed at a temperature of 60 ° C., followed by heat treatment at a temperature of 120 ° C. to form a light emitting layer.

<Formation of electron transport layer>
Subsequently, after forming the light emitting layer, the following coating liquid for forming an electron transport layer was applied by an extrusion coater and then dried to form an electron transport layer. The coating solution for forming an electron transport layer was applied so that the thickness after drying was 30 nm.

(Application conditions)
The coating process was performed in an atmosphere having a nitrogen gas concentration of 99% or more, the coating temperature of the electron transport layer forming coating solution was 25 ° C., and the coating speed was 1 m / min.

(Coating liquid for electron transport layer formation)
The electron transport layer was prepared by dissolving EA in 2,2,3,3-tetrafluoro-1-propanol to obtain a 0.5 mass% solution as a coating solution for forming an electron transport layer.

(Drying and heat treatment conditions)
After applying the electron transport layer forming coating solution, the film was blown onto the film forming surface and the solvent was removed at a temperature of 60 ° C., and then the heat treatment was performed at a temperature of 120 ° C. to form an electron transport layer.

(Formation of electron injection layer)
An electron injection layer was formed on the formed electron transport layer. First, the substrate was put into a vacuum chamber and the pressure was reduced to 5 × 10 ⁻⁴ Pa. In advance, cesium fluoride prepared in a tantalum vapor deposition boat was heated in a vacuum chamber to form an electron injection layer having a thickness of 3 nm.

(Formation of second electrode)
On the electron injection layer formed on the first electrode except for the portion to become the extraction electrode, aluminum is used as the second electrode forming material under a vacuum of 5 × 10 ⁻⁴ Pa, and light is emitted by vapor deposition. A mask pattern was formed to have an extraction electrode with an area of 50 mm square, and a second electrode having a thickness of 100 nm was laminated.

(Cutting)
The gas barrier flexible film formed up to the second electrode was moved again to the nitrogen atmosphere.

A flexible gas barrier film was cut into a specified size.

(Electrode lead connection)
As shown in FIG. 1A, an anisotropic conductive film DP3232S9 manufactured by Sony Chemical & Information Device Co., Ltd. is used for the electrode lead-out portion 2a of the produced organic EL element 40, and a flexible printed board (base film: polyimide 12. Electrode leads 7 of 5 μm rolled copper foil 18 μm, coverlay: polyimide 12.5 μm, surface-treated NiAu plating) were connected by the conductive adhesive 8.

Crimping conditions: temperature 120 ° C. (ACF temperature 120 ° C. measured using a separate thermocouple), pressure 2 MPa, 10 seconds, and at this time, crimping was performed so as to form as shown in FIG.

(Sealing)
As shown in FIG. 1B, the organic EL element 40 to which the electrode lead 7 (flexible printed circuit board) is connected is bonded to the sealing member 50 using a commercially available roll laminating apparatus (not shown). The organic EL panel 60 shown in c) was manufactured.

As the sealing member 50, a 30 μm thick aluminum foil (manufactured by Toyo Aluminum Co., Ltd.), a polyethylene terephthalate (PET) film (12 μm thick) and an adhesive for dry lamination (two-component reaction type urethane adhesive) The sealing base material 5 laminated with (adhesive layer thickness 1.5 μm) was used.

The thermosetting adhesive 6 was applied uniformly to the aluminum surface with a thickness of 20 μm on the adhesive surface (glossy surface) of the aluminum foil using a dispenser.

The following epoxy adhesive was used as the thermosetting adhesive.

Bisphenol A diglycidyl ether (DGEBA)
Dicyandiamide (DICY)
Epoxy adduct-based curing accelerator After that, the sealing member 50 is closely attached and arranged so as to cover the joint between the extraction electrode and the electrode lead so as to have a form as shown in FIG. The organic EL panel 60 was obtained by tightly sealing with use. The organic EL panel corresponds to the surface light emitting device in the present invention.

Each surface light emitting element using the substrate described in Table 1 was formed.

(Preparation of decorative luminous body 101 having a decorative layer with curable ink)
An uncured decorative layer 9 is formed by screen printing on the surface of the substrate 1 on the light extraction side of each surface light-emitting element obtained above using a screen printing method. The cured decorative layer 9 is irradiated with ultraviolet rays from the surface side under the conditions of a FUSION H bulb 1,000 mJ / cm to cure the curable resin layer to form the decorated layer 9. Each decorative luminous body 101 was obtained in combination (see FIG. 1D). The decorative layer 9 was formed so that the film thickness after curing was 10 μm.

<Evaluation>
A constant voltage was applied to each of the obtained decorative light emitters, and the total luminous flux of the decorative surface when the organic EL element was allowed to emit light was measured with an integrating sphere, and the light emission efficiency was calculated. The light emission efficiency in Table 1 was evaluated as a relative value when a sample using the decorative light emitter 101, the substrate PET, and the decorative layer V-9530 was 100.

As can be seen from Table 1, the light extraction efficiency is 80% or more by combining the refractive index of the substrate of the organic EL element and the decorative layer within the range of the present invention (the range marked with * in Table 1). It can be seen that a high and bright decorative illuminant can be obtained.

Example 2
In the production of the decorative light-emitting body 101 of Example 1, the substrates listed in Table 2 were used for the surface roughness, centerline average roughness Ra, maximum height Ry, and 10-point average height Rz of the PET surface of the substrate 1. Except that, decorative light emitters were produced in the same manner.

<Evaluation>
The following evaluation was performed using each obtained decoration light-emitting body.

<Leakage current value>
Using a decorative illuminator inspection device, apply a reverse bias voltage of 0 to -3 V to each decorative illuminator, measure the leakage current (displayed as R current) at that time, and set a current value of 0.001 mA or more. A panel in which an R current was observed was evaluated as R current x, and a panel having a lower current value was evaluated as R current ◯.

A block diagram of the decorative light emitting device inspection apparatus used is shown in FIG.

2, the decorative light emitter inspection device 20 includes a power supply unit 22 and a control unit 23 which are voltage application means.

The power supply unit 22 sequentially applies a voltage from 0V to −3V to the decorative light emitter 21 which is a voltage object, and subsequently sequentially applies voltages of different values from −3V to 0V. The control unit 23 controls the voltage of the power supply unit 22 and measures the VI characteristic. The power supply unit 22 has a function of measuring and recording either the voltage V or the current I.

If a spike-like leakage current is seen in the VI characteristic of the decorative light emitter 21, there is a high probability that the decorative light emitter 21 will suddenly stop light emission. Therefore, the leakage current R when a voltage is applied is measured. A case where a leak current of 001 mA or more is seen is determined to be defective.

<Adhesion of decorative layer>
The adhesion of the decorative layer formed on the substrate was evaluated by the following cross-cut tape peeling method, and 90 or more were evaluated as a film with o, and less than 90 were evaluated as a film with x.

(Cross cut tape peeling method)
This is a test method for examining the adhesion of the decorative layer to the substrate.

Using a cutter knife on the hardened decorative layer, draw 11 parallel lines running vertically and horizontally at 1 mm intervals, and make a grid-like cut so that 100 squares can be formed in 1 cm ² . Adhere Cellotape (Registered Trademark) to the grid area and pull away rapidly.

The judgment is “100” if there is no peeling at all, and if there is a peeling grid, the number of remaining grids is recorded.

The evaluation results are shown in Table 2.

As can be seen from the results in Table 2, each surface roughness coefficient is set to a specific range of the present invention (the range marked with * in Table 2), so that the leakage current is small and the film is good. Thus, it can be seen that a decorative light emitter having excellent durability can be obtained.

Example 3
An optical glass BK-7 is used as the substrate of the organic EL panel 60 formed in Example 1, and the following thermosetting ink-jet ink is used in place of the ultraviolet curable ink used in the decorative light-emitting body 101. A decorative illuminant was formed in the same manner except that the decorative layer was formed using.

<< Preparation of thermosetting inkjet ink >>
<Red ink>
C. I. Pigment Red 254 22 parts Propylene glycol monomethyl ether acetate (solvent) 41 parts Resin solution 15 parts (benzyl methacrylate / methacrylic acid / hydroxyethyl methacrylate (= 80/10/10 [molar ratio]) copolymer (weight average molecular weight = 10) , 000) propylene glycol monomethyl ether acetate 40% (resin solids) solution)
Dispersant (BY-161, manufactured by BYK) 6 parts Next, 76 parts of propylene glycol monomethyl ether acetate (solvent) was further added to the obtained kneaded dispersion, and fine dispersion treatment was performed all day and night in a sand mill. After the fine dispersion treatment, each component of the following composition B was further added and mixed by stirring to prepare a Red ink.

[Composition B]
33 parts of EHPE3150 (manufactured by Daicel-Cytec Corp .; calculated epoxy equivalent = 140)
3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone 3 parts Tetranic 150R1 (manufactured by BASF, surfactant) 0.2 part 1,3-butanediol diacetate 100 parts <Green ink>
C. I. Instead of Pigment Red 254, C.I. I. Green ink was prepared in the same configuration and procedure as the Red ink except that 30 parts of Pigment Green 36 were used.

<Blue ink>
C. I. Instead of Pigment Red 254, C.I. I. Blue ink was prepared in the same configuration and procedure as the Red ink except that 20 parts of Pigment Blue 66 was used.

<Production of decorative layer>
The red, green, and blue inks prepared above were ejected and deposited by an inkjet method using a piezo element to form a light transmissive full color image layer.

After the discharge, a heat treatment was performed at 120 ° C. for 10 minutes to cure and produce a decorative layer. The refractive index of the decorative layer after curing was 1.56.

The ink-jet method can be applied in a small area, and damage to the organic EL element due to heat treatment is small, and a bright full-color image can be easily formed.

Example 4
In the formation of the decorative luminescent material 101 used in Example 3, a curable ink was prepared in the same manner except that the following two-component curable ink was used in place of the thermosetting ink used, and the screen printing method was used to produce the curable ink 101 shown in FIG. A decorative layer having the transmission image pattern shown in FIG.

The two-component curable ink used was a 9300 series ink manufactured by Toago Paper Co., Ltd., and two components were mixed immediately before printing.

The feature of the two-component curing type is that a coating film having excellent mechanical strength and good adhesion can be formed on the substrate.

The obtained decorative layer had a good transmission image pattern. Further, the obtained decorative layer had high scratch resistance. The refractive index of the decorative layer after curing was 1.50.

Example 5
In the formation of the decorative light emitting body 101 used in Example 4, a decorative layer (see FIG. 4) was formed by a screen printing method using visible light curable ink instead of the two-component curable ink.

The visible light curable ink used was formed by dispersing a patterning material in LCR0754 manufactured by Toa Chemical Co., Ltd. As required, Y, M, C, and Bk inks were stacked in multiple layers to produce a desired pattern. As a result, as shown in FIG. 4, the decorative layer can be printed in the form of Japanese paper, marble, or wood, and the decorative light emitting body 101 that is a decorative board with illumination can be easily obtained.

The refractive index of the decorative layer after curing was 1.50.

In the ultraviolet curable type, the luminescent material may be partially broken by the ultraviolet light irradiated at the time of curing, and the luminous efficiency may be lowered. However, in the visible light curable type, there is no need to worry about that, and there is no limitation on the material that can be used for the light emitting layer or the limitation on the amount of light irradiation, so that a preferable mode can be implemented.

Example 6
In the production of the decorative light emitting body 101 of Example 1, in addition to the ultraviolet irradiation from the printing surface, the organic EL panel was energized to emit light from the organic EL layer, and irradiation from the inside was performed to promote curing. As a result, it was found that when the film thickness of the decorative layer was evaluated by the above-described crosscut tape peeling method, it was improved by 30% or more when compared with the same curing time.

Example 7
In the formation of the decoration layer of Example 5, the decoration light-emitting body 101 was formed in the same manner except that the patterning material used in the ink was not used and the transparent decoration layer was used. On the obtained decorative layer, a polyvinyl butyral aqueous solution in which silica fine particles were dispersed was applied and dried to form an ink jet image receiving layer.

The decorative light-emitting body 101 having the ink jet image receiving layer thus obtained can easily form a favorite image such as a photographic image on the ink jet image receiving layer by an ink jet printing method.

From the above embodiments of the present invention, a decorative luminescent material that is easy, inexpensive, suitable for a wide variety and in small quantities, has high energy consumption efficiency, high brightness, does not generate heat, is safe, and has excellent scratch resistance. Could be provided.

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Anode 2a Anode exterior taking-out part 3 Organic compound layer 4 Cathode 4a Cathode outside taking-out part 5 Sealing base material 6 Adhesive for sealing 7 Electrode lead 8 Conductive adhesive 9 Decoration layer 20 Decoration light emitter inspection apparatus 21 Decoration Light-emitting body 22 Power supply section 23 Control section 40 Organic EL element 50 Sealing member 60 Organic EL panel 101 Decorative light-emitting body

Claims

In a decorative light-emitting body having a decorative layer formed of a curable ink on a substrate surface on the light extraction side of a surface light emitting device, the refractive index of the substrate is n1, and the refractive index of the decorative layer formed of the curable ink is A decorative illuminant characterized in that n1 and n2 satisfy the following relationships 1), 2) and 3) when the rate is n2.
1) 1.4 ≦ n1 ≦ 1.9
2) 1.4 ≦ n2 ≦ 1.9
3) | n1-n2 | ≦ 0.2
In the surface roughness of the substrate of the surface light emitting device, the center line average roughness Ra, the maximum height Ry, and the 10-point average height Rz are respectively expressed by the following formulas 4), 5), and 6): The decorative light-emitting body according to claim 1.
4) 0.1 nm ≦ Ra ≦ 10 nm
5) 1.0 nm ≦ Ry ≦ 100 nm
6) 1.0 nm ≦ Rz ≦ 100 nm
The decorative illuminator according to claim 1 or 2, wherein the curable ink is a thermosetting ink.
The decorative illuminator according to claim 1 or 2, wherein the curable ink is a two-component curable ink.
The decorative luminescent material according to claim 1, wherein the curable ink is a photocurable ink.
The decorative light-emitting body according to claim 5, wherein the photocurable ink is a visible light curable ink.
The decorative light-emitting body according to claim 5, wherein the photocurable ink is an ultraviolet curable ink.
The decorative luminous body according to any one of claims 1 to 7, wherein the decorative layer is formed by screen printing.
The decorative luminous body according to any one of claims 1 to 7, wherein the decorative layer is formed by ink jet printing.
The decorative light emitting body according to any one of claims 1 to 9, wherein the surface light emitting element is an organic EL element.
In the method for producing a decorative light emitter having a decorative layer formed by the step of forming a curable ink layer on the light extraction side substrate surface of the surface light emitting element, the step of irradiating the formed curable ink layer with ultraviolet rays, A method for producing a decorative luminescent material, comprising: a step of irradiating the surface of the curable ink layer with ultraviolet rays; and a step of energizing the surface light emitting element to emit light.
In the method for producing a decorative light emitter having a decorative layer formed by the step of forming a curable ink layer on the light extraction side substrate surface of the surface light emitting element, the step of irradiating the formed curable ink layer with ultraviolet rays, A method for producing a decorative luminescent material, wherein the ultraviolet irradiation in the step of irradiating ultraviolet rays simultaneously performs the following 1) and 2).
1) Irradiation from above the curable ink layer 2) Irradiation from the end face of the light extraction side substrate of the surface light emitting element