JP2005235467A - Organic el element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide, at a low cost, a long-life organic EL element keeping an excellent gas barrier property even if it is bent. <P>SOLUTION: This organic EL element comprises a first laminated film, a second laminated film and an adhesive for sealing a part between them. The first laminated film includes a first laminated film having a gas barrier property and a luminescent organic film including an electrode and an organic luminescent material. The second laminated film includes a second laminated film having a gas barrier property and an electrode, and is arranged oppositely to the first laminated film by interposing the luminescent organic film. The first and second laminated films having the gas barrier property each comprise a base material film, and at least one inorganic layer and at least one resin layer formed on the base material film. In the organic EL element, steam permeability is below 5 g/m<SP>2</SP>day at 40°C and at a relative humidity of 90% when the film thickness of the adhesive is 100 μm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a flexible organic EL device (organic electroluminescence device) that has an excellent gas barrier property, has a significantly improved lifetime, and has an excellent production efficiency.

  Conventionally, a gas barrier film in which a metal oxide thin film such as aluminum oxide, magnesium oxide, silicon oxide or the like is formed on the surface of a plastic film or film is used for packaging of articles that require blocking of various gases such as water vapor and oxygen. Alternatively, it is widely used in packaging for preventing the deterioration of food, industrial products, pharmaceuticals, and the like. In addition to packaging, it is used in liquid crystal display elements, solar cells, electroluminescence (EL) films and the like. In particular, transparent substrates that have been applied to liquid crystal display elements, EL elements, etc. have recently been required to be lighter and larger, have long-term reliability and a high degree of freedom in shape, and can display curved surfaces. With the addition of high demands such as, film substrates such as transparent plastics are beginning to be used in place of glass films that are heavy, fragile and difficult to increase in area. In addition, the plastic film not only satisfies the above requirements, but also has a roll-to-roll method, and is therefore more advantageous than glass because of higher productivity and cost reduction.

However, a film substrate such as a transparent plastic has a problem that the gas barrier property is inferior to glass. And a base material with inferior gas barrier property permeate | transmits water vapor | steam and air, for example, degrades the liquid crystal in a liquid crystal cell, becomes a display defect, and degrades display quality. In order to solve such problems, it is known to form a metal oxide thin film on a film to form a gas barrier film substrate. Gas barrier films used for packaging materials and liquid crystal display elements include those obtained by vapor-depositing silicon oxide on a plastic film (pages 1 to 3 of Patent Document 1) and those obtained by vapor-depositing aluminum oxide (Patent Document 2). Page 1 to page 4) are known, and all have a water vapor barrier property of about 1 g / m ² / day. However, in recent years, the demand for the gas barrier performance of a film with a water vapor barrier has increased to about 0.1 g / m ² / day due to the development of large-sized liquid crystal displays and high-definition displays.

Furthermore, in recent years, organic EL displays that require further barrier properties have been developed, and while maintaining the transparency that can be used therefor, even higher barrier properties, in particular, 0.01 g / m ² / A substrate having a performance of less than day has been demanded. In order to respond to this, as a means for expecting higher barrier performance, studies on film formation by a sputtering method or a CVD method in which a thin film is formed using plasma generated by glow discharge under a low pressure condition have been conducted.

  Further, Patent Document 3 (Page 4 [2-5] to Page 5 [4-49]) and Patent Document 4 describe a technique for producing a barrier film having an alternately laminated structure of resin layers / inorganic layers by a vacuum deposition method. (3rd page [0006] to 4th page [0008]). In these, a gas barrier film in which a resin layer / inorganic layer is laminated on a transparent resin layer is disposed, an organic EL structure including a light emitting layer is disposed thereon, and a resin layer / inorganic layer is further laminated thereon. Thus, it is configured to provide barrier properties. Although this method has good performance as a gas barrier property, it is necessary to sequentially form a resin layer and an inorganic layer on the organic EL structure by a method such as vapor deposition, sputtering, and plasma CVD. There was a problem of being bad. In addition, there is a high risk of damaging the organic EL structure during this process, and the yield is also a serious problem.

Japanese Patent Publication No.53-12953 JP 58-217344 A US Pat. No. 6,268,695 JP 2003-53881 A

  This invention is made | formed in view of the said subject, and the 1st objective of this invention is to provide the organic EL element which can achieve a long lifetime by maintaining the gas barrier property which was excellent even if it bent. The second object of the present invention is to provide an organic EL device capable of producing a long-life organic EL device having the gas barrier property at low cost.

  The above object has been achieved by the following means.

(1) The first laminated film comprises at least a first laminated film, a second laminated film, and an adhesive that seals between the first laminated film and the second laminated film. Comprises a first gas barrier laminate film and a light emitting organic film comprising an electrode and an organic light emitting material provided on the first gas barrier laminate film. Gas barrier laminate film, and an electrode provided on the second gas barrier laminate film, and disposed opposite the light-emitting organic film side of the first laminate film, Each of the first gas barrier laminate film and the second gas barrier laminate film includes a base film, and at least one inorganic layer provided on the base film. Becomes a resin layer of one layer, and, in that the water vapor transmission rate when the film thickness of the adhesive is 100μm is, 40 ° C., or less 5g / m ² · day at 90% relative humidity conditions A characteristic organic EL element.

(2) Contact between the surface of the first laminated film in contact with the adhesive and the surface of the second laminated film in contact with the adhesive at 25 ° C. and 60% relative humidity with water The angles are all in the range of 0 to 50 degrees, and the contact angles with water at 25 ° C. and 60% relative humidity after the adhesive is cured are all in the range of 0 to 80 degrees. The organic EL element according to (1), characterized in that

(3) The organic EL element according to (1) or (2), wherein a shrinkage ratio accompanying the curing of the adhesive is 5% or less.

(4) The organic EL element according to any one of (1) to (3), wherein the adhesive is a visible light curable type.

  According to the present invention, a flexible and long-life organic EL element can be obtained. Moreover, this invention can be utilized as a technique which can produce a flexible organic EL element at low cost.

  Hereinafter, the contents of the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

(1) Gas barrier laminate film The first gas barrier laminate film and the second gas barrier laminate film of the present invention each have, for example, at least one layer on at least one surface of a film (substrate film) serving as a substrate. It is a gas barrier laminated film formed by forming an inorganic layer and at least one resin layer.
Next, each component of the gas barrier laminate film of the present invention will be described.

  The method for forming the inorganic layer of the present invention may be any method as long as the target thin film can be formed, but sputtering, vacuum deposition, ion plating, plasma CVD, and the like are suitable. Films can be formed by the methods described in Japanese Patent Nos. 3430344, 2002-322561, and 2002-361774.

  Specifically, for example, the film can be formed using a commercially available roll-to-roll type sputtering apparatus. The sputtering apparatus has a vacuum chamber, and a drum for heating or cooling the substrate film in contact with the surface is disposed at the center thereof. Moreover, the winding tank for winding a base film is arrange | positioned at the said vacuum chamber. The base film wound on the roll is wound on a drum via a guide, and further wound on a take-up roll via another guide. In the vacuum exhaust system, the vacuum chamber is always exhausted from the exhaust port by a vacuum pump. As a film forming system, a target is mounted on a cathode connected to a DC discharge power source to which pulse power can be applied. This discharge power source is connected to a controller, and this controller is further connected to a piezoelectric element valve unit that supplies the vacuum chamber while adjusting the amount of reaction gas introduced through a pipe. The vacuum chamber is configured to be supplied with a constant flow rate of discharge gas. The amount of reaction gas introduced is set so that the desired film quality can be obtained, and the discharge is sustained in the transition region. If the voltage value at this time is set as the set voltage value and the voltage value is larger than the set value, the controller sends a command to the piezoelectric element valve unit to reduce the reaction gas flow rate. If the voltage value is smaller than the set value, the controller sends a command to the piezoelectric element valve unit to increase the reaction gas flow rate. In this way, the flow rate of the reaction gas supplied to the vacuum chamber is controlled to an appropriate amount.

The components of the inorganic layer are not particularly limited, and for example, an oxide, nitride, oxynitride, or the like containing one or more of Si, Al, In, Sn, Zn, Ti, Cu, Ce, Ta, and the like can be used. . Although it does not specifically limit regarding the thickness of an inorganic layer, The range of 5 nm-1000 nm is preferable, More preferably, it is 10 nm-1000 nm, Most preferably, it is 10 nm-200 nm. By setting the thickness to 1000 nm or less, cracks due to bending stress can be more effectively prevented, and by setting the thickness to 5 nm or more, it is possible to more effectively prevent the film from being distributed in stripes. Note that the occurrence of cracks and the distribution of the film in stripes tend to lead to a tendency for water vapor barrier properties to deteriorate.
In the present invention, two or more inorganic layers are provided, but each may have the same composition or a different composition, and there is no limitation.
In order to achieve both water vapor barrier properties and high transparency, it is preferable to use silicon oxide or silicon oxynitride as the inorganic layer. Silicon oxide is expressed as SiOx. For example, when SiOx is used as the inorganic layer, it is desirable that 1.6 <x <1.9 in order to achieve both good water vapor barrier properties and high light transmittance. Although silicon oxynitride is expressed as SiOxNy, the ratio of x and y is preferably an oxygen-rich film when adhesion improvement is important, and 1 <x <2, 0 <y <1, and water vapor barrier properties When importance is attached to improvement, a nitrogen-rich film is preferable, and 0 <x <0.8 and 0.8 <y <1.3 are preferable.

On the other hand, the resin layer is preferably formed by curing a radical polymerizable monomer having a vinyl group such as an acrylate group or a methacrylate group, or a cationic ring-opening polymerizable monomer having a cyclic ether group such as an epoxy group or an oxetanyl group. These monomers may be monofunctional or polyfunctional depending on the use, and both may be used in combination.
Moreover, in this invention, the resin layer may contain components other than an organic component, ie, an inorganic substance, an inorganic element, and a metal element.

  The thickness of the resin layer is not particularly limited, but is preferably 10 nm to 5000 nm, more preferably 20 to 2000 nm, and most preferably 50 nm to 500 nm. By setting the thickness of the resin layer to 5000 or less, the thickness uniformity can be maintained and the structural defects of the inorganic layer can be more efficiently filled with the resin layer. In addition, by setting the thickness of the resin layer to 10 nm or more, the resin layer is more effectively prevented from being cracked by an external force such as bending. That is, the barrier property can be more effectively improved by setting the thickness of the resin layer to 10 nm to 5000 nm.

  Examples of the method for forming the resin layer of the present invention include a coating method and a vacuum film forming method. Although there is no restriction | limiting in particular as a vacuum film forming method, Film forming methods, such as vapor deposition and plasma CVD, are preferable, and the resistance heating vapor deposition method which is easy to control the film forming rate of an organic substance monomer is more preferable. There is no limitation on the method for crosslinking the organic monomer of the present invention, but crosslinking by electron beam or ultraviolet rays by irradiation with active energy rays is easy to attach in a vacuum chamber and high molecular weight by crosslinking reaction is rapid. This is desirable.

  When creating by the coating method, various conventionally used coating methods such as roll coating, gravure coating, knife coating, dip coating, curtain flow coating, spray coating, and bar coating may be used. it can.

  In the formation of the resin layer in the present invention, an organic-inorganic hybrid material may be obtained by jointly using hydrolysis and polycondensation reaction of metal alkoxide. As the metal alkoxide, an alkoxysilane and / or a metal alkoxide other than alkoxysilane is used. As the metal alkoxide other than alkoxysilane, zirconium alkoxide, titanium alkoxide, aluminum alkoxide and the like are preferable. Moreover, you may mix inorganic fillers, such as a well-known inorganic fine particle and layered silicate, with a resin layer as needed.

The active energy ray in the present invention refers to radiation that can propagate energy by irradiation with ultraviolet rays, X-rays, electron beams, infrared rays, microwaves, and the like, and the type and energy can be arbitrarily selected according to the application. it can.
Cationic ring-opening polymerization of the monomer of the present invention is initiated by contact heating with a heater or the like, or radiation heating such as infrared rays or microwaves when a thermal polymerization initiator is used after applying or vapor-depositing the composition containing the monomer. . When a photopolymerization initiator is used, it is started by irradiation with active energy rays. When irradiating with ultraviolet light, various light sources can be used, such as curing with mercury arc lamp, xenon arc lamp, fluorescent lamp, carbon arc lamp, tungsten-halogen radiation lamp and irradiation light by sunlight. . The irradiation intensity of ultraviolet rays is preferably at least 10 mJ / cm ² . When curing is performed continuously, it is preferable to set the irradiation rate so that the composition can be cured within 1 to 20 seconds. In the case of curing with an electron beam, curing is performed with an electron beam having an energy of 300 eV or less, but it is also possible to cure instantaneously with an irradiation amount of 1 Mrad to 5 Mrad.

  At least one inorganic layer and resin layer may be provided on one side or both sides of the base film as long as the gas barrier property is maintained. Further, one inorganic layer and a resin layer may be repeatedly laminated adjacent to the above-described lamination. Particularly preferred is a case where a pair of inorganic layers and resin layers are formed as repeating units, and it is preferably 5 units or less, preferably 2 units or less from the viewpoint of gas barrier properties and production efficiency. Moreover, when forming a repeating unit, each inorganic layer and each resin layer may have the same composition or different compositions.

  In addition to the lamination of the inorganic layer and the resin layer, for example, a primer layer and other functional layers as described below may be provided.

  The first laminated film and the second laminated film of the present invention are provided with a known primer layer or inorganic thin film layer between the film serving as the base material and the gas barrier laminate within a range not departing from the gist of the present invention. Can be installed. As the primer layer, for example, an acrylic resin, an epoxy resin, a urethane resin, a silicone resin or the like can be used. In the present invention, an organic-inorganic hybrid layer is used as the primer layer, and an inorganic vapor-deposited layer or an inorganic thin-film layer is used. A dense inorganic coating thin film by a sol-gel method is preferred. As an inorganic vapor deposition layer, vapor deposition layers, such as a silica, a zirconia, an alumina, are preferable. The inorganic vapor deposition layer can be formed by a vacuum vapor deposition method, a sputtering method, or the like.

  Various well-known functional layers may be provided on the gas barrier laminated film without departing from the gist of the present invention. Examples of such functional layers include optical functional layers such as antireflection layers, polarizing layers, color filters, ultraviolet absorbing layers, light extraction efficiency improving layers, mechanical functional layers such as hard coat layers and stress relaxation layers, and antistatic Examples thereof include an electrical functional layer such as a layer / conductive layer, an antifogging layer, an antifouling layer, and a printing layer.

Water vapor permeability of the gas barrier laminate film of the present invention is preferably not more than 0.01g / m ² · day, even more preferably at most 0.005g / m ² · day. Similarly, oxygen permeability is preferably from ^{0.01ml / m 2 · day · atm} , and particularly preferably not more than ^{0.005ml / m 2 · day · atm} .
Assuming that a flexible and transparent organic EL element is produced, the light transmittance of the gas barrier laminate film is an important performance. The light transmittance value is preferably 80% or more, particularly preferably 85% or more at 550 nm.
As flexibility, it is necessary that the surface does not change even if it is bent for one day at a curvature of 100 mm, but more preferably it can withstand a curvature of 10 mm.
Moreover, since the gas barrier laminated film as the first laminated film undergoes a process for producing an electrode such as a TFT, it requires extremely high temperature heat resistance. It is necessary that no deformation occurs at least up to 250 ° C., and it is more preferable that it can withstand use up to 350 ° C.
In order not to peel off the organic EL structure due to temperature change or to create a gap at the interface with the adhesive, the thermal expansion coefficient of the gas barrier laminate film is 100 ppm or less, preferably 50 ppm or less, particularly preferably 20 ppm or less.

  The base film material used in the gas barrier laminate film of the present invention is not particularly limited as long as it is a film capable of holding each of the above layers, and can be appropriately selected from the intended use of the barrier film. Specifically, methacrylic resin, methacrylic acid-maleic acid copolymer, polystyrene, transparent fluororesin, polyimide resin, fluorinated polyimide resin, polyamide resin, polyamideimide resin, polyetherimide resin, cellulose acylate resin, polyurethane resin, Thermoplastic resins such as polyether ether ketone resin, polycarbonate resin, alicyclic polyolefin resin, polyarylate resin, polyether sulfone resin, polysulfone resin, cycloolefin copolymer, fluorene ring modified polycarbonate resin, alicyclic modified polycarbonate resin, acryloyl compound Is mentioned.

Among these base film materials, preferred examples include polyarylate resin (PAR), polyethersulfone resin (PES), fluorene ring-modified polycarbonate resin (BCF-PC: Example 4 of JP-A-2000-227603). Compound), alicyclic modified polycarbonate resin (IP-PC: compound of Example-5 of JP-A-2000-227603), acryloyl compound (compound of Example-1 of JP-A-2002-80616). It is done.
It is also preferable to use a condensation polymer containing spirobiindane or spirobichroman. Although it is a compound with high heat resistance, it is a compound having a high modulus of elasticity and high tensile fracture stress. Various heating operations are required in the manufacturing process, and the performance of organic EL that is difficult to break even when bent is required. It is because it is suitable as a film material.

  Each of the structural units of the resin of the present invention may be only one type, or two or more types may be mixed. Moreover, the other structural unit may be included in the range which does not impair the effect of this invention. The amount of substitution is usually preferably 50 mol% or less, and more preferably 10 mol% or less. Moreover, other resin may be blended with the resin of this invention, and it may be comprised from 2 or more types of resin.

  The molecular weight of the resin of the present invention is preferably 10,000 to 300,000 (polystyrene conversion) in terms of number average molecular weight, more preferably 20,000 to 200,000, and most preferably 30,000 to 150,000. By setting the molecular weight to 10,000 or more, the mechanical strength when used as a plastic film becomes higher.

  As the base film material of the present invention, a crosslinked resin can also be preferably used from the viewpoint of solvent resistance, heat resistance and the like. As the type of the cross-linked resin, various known ones can be used for both the thermosetting resin and the radiation curable resin. Examples of the thermosetting resin include phenol resin, urea resin, melamine resin, unsaturated polyester resin, epoxy resin, silicone resin, diallyl phthalate resin, furan resin, bismaleimide resin, cyanate resin and the like. Any other crosslinking method can be used without particular limitation as long as it is a reaction that forms a covalent bond, and a system in which the reaction proceeds at room temperature using a polyalcohol compound and a polyisocyanate compound to form a urethane bond is also particularly limited. Can be used without

  Usually, such a system is preferably used as a two-component mixed type in which a polyisocyanate compound is added immediately before film formation so that the pot life before film formation does not become a problem. On the other hand, when used as a one-pack type, it is preferable to protect the functional group involved in the crosslinking reaction. These are also marketed as block type curing agents, such as B-882N manufactured by Mitsui Takeda Chemical Co., Ltd., Coronate 2513 manufactured by Nippon Polyurethane Industry Co., Ltd. (above block polyisocyanate), Cymel 303 manufactured by Mitsui Cytec Co., Ltd. Methylated melamine resin) is known. A blocked carboxylic acid that protects a polycarboxylic acid that can be used as a curing agent for an epoxy resin is also known.

  Radiation curable resins are roughly classified into radical curable resins and cationic curable resins. As the curable component of the radical curable resin, a compound having a plurality of radical polymerizable groups in the molecule is used. As a typical example, a polyfunctional acrylate monomer having 2 to 6 acrylate groups in the molecule And compounds having a plurality of acrylate groups in the molecule called urethane acrylate, polyester acrylate, and epoxy acrylate. As a typical curing method of the radical curable resin, there are a method of irradiating an electron beam and a method of irradiating ultraviolet rays. Usually, in the method of irradiating with ultraviolet rays, a polymerization initiator that generates radicals upon irradiation with ultraviolet rays is added. In addition, if the polymerization initiator which generate | occur | produces a radical by heating is added, it can also be used as a thermosetting resin. As the curable component of the cationic curable resin, a compound having a plurality of cationic polymerizable groups in the molecule is used. As a typical curing method, a photoacid generator that generates an acid upon irradiation with ultraviolet rays is added, and ultraviolet rays are added. And a method of curing by irradiation. Examples of the cationically polymerizable compound include a compound containing a ring-opening polymerizable group such as an epoxy group and a compound containing a vinyl ether group.

  A plurality of the thermosetting resins and radiation curable resins mentioned above may be mixed and used, or a thermosetting resin and a radiation curable resin may be used in combination. Moreover, you may mix and use a crosslinkable resin and the polymer which does not have a crosslinkable group.

  Furthermore, when these crosslinkable resins are mixed and used in the resin used as a raw material for the base film of the present invention, the solvent resistance, heat resistance, optical properties, and toughness of the obtained base film can be satisfied. . Moreover, it is also possible to introduce a crosslinkable group into the resin of the present invention, and it may have a crosslinkable group at any site in the polymer main chain terminal, the polymer side chain, or the polymer main chain. In this case, a plastic film may be produced without using the general-purpose crosslinkable resin mentioned above.

For the purpose of controlling retardation (Re) and improving gas permeability and mechanical properties, a laminate or blend of different resins can be suitably used for the base film.
There is no restriction | limiting in particular as a preferable combination of different resin, Any resin mentioned above can be used.
In addition, for the purpose of greatly changing the retardation, an organic low molecular weight compound is used as disclosed in JP-A-7-92904, or optical anisotropy is disclosed in WO98 / 04601. It is also possible to block copolymerize monomers having different properties.
Further, as disclosed in JP-A-11-293116, it is also a preferred method to add optically anisotropic inorganic fine particles having orientation.

  The base film material of the present invention may be stretched. By stretching, mechanical strength such as folding strength is improved, and there is an advantage that handling property is improved. In particular, those having an orientation release stress (ASTM D1504, hereinafter abbreviated as ORS) in the stretching direction of 0.3 to 3 GPa are preferred because the mechanical strength is improved. ORS is the internal stress caused by stretching that is frozen in a stretched film or sheet.

  For stretching, a known method can be used. For example, a roll uniaxial stretching method, a tenter uniaxial stretching method, a simultaneous biaxial stretching at a temperature between 10 ° C. and 50 ° C. higher than the glass transition temperature (Tg) of the resin. The film can be stretched by a method, a sequential biaxial stretching method, or an inflation method. The draw ratio is preferably 1.1 to 3.5 times.

  The thickness of the base film of the present invention is not particularly limited, but is preferably 30 μm to 700 μm, more preferably 40 μm to 200 μm, and still more preferably 50 μm to 150 μm. Further, in any case, the haze is preferably 3% or less, more preferably 2% or less, further preferably 1% or less, and the total light transmittance is preferably 70% or more, more preferably 80% or more, and further preferably 90%. That's it.

  In the base film of the present invention, a plasticizer, a dye / pigment, an antistatic agent, an ultraviolet absorber, an antioxidant, an inorganic fine particle, a peeling accelerator, a leveling agent, an inorganic material as long as the effects of the present invention are not impaired as necessary. A resin modifier such as a layered silicate compound and a lubricant may be added.

(2) The organic EL device of the present invention is obtained by bonding the first laminated film and the second laminated film with an adhesive. Here, the first laminated film is obtained by providing at least a light emitting organic film made of an electrode and an organic light emitting material on the gas barrier laminated film, and the second laminated film is formed on the gas barrier laminated film. Further, at least an electrode is provided. Here, the organic EL structure is formed by the electrode included in the first laminated film, the light-emitting organic film, and the electrode contained in the second laminated film.

(3) Organic EL structure The anode of the organic EL structure usually has a function as an anode (electrode) for supplying holes to the light-emitting organic film. There is no restriction | limiting in particular about it etc., According to the use and objective of a light emitting element, it can select suitably from well-known electrodes.

  Suitable examples of the material for the anode include metals, alloys, metal oxides, organic conductive compounds, and mixtures thereof, and materials having a work function of 4.0 eV or more are preferable. Specific examples include semiconducting metal oxides such as tin oxide (ATO, FTO) doped with antimony or fluorine, tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), etc. A metal such as gold, silver, chromium, nickel, etc., a mixture or laminate of these metals and conductive metal oxides, an inorganic conductive material such as copper iodide, copper sulfide, the semiconductive metal oxide or Examples thereof include dispersions of metal compounds, organic conductive materials such as polyaniline, polythiophene, and polypyrrole, and laminates of these with ITO.

  The anode includes, for example, a printing method, a wet method such as a coating method, a physical method such as a vacuum deposition method, a sputtering method, and an ion plating method, a chemical method such as CVD and a plasma CVD method, and the like. The film can be formed on the film according to a method appropriately selected in consideration of the suitability of the film. For example, when ITO is selected as the anode material, the anode can be formed according to a direct current or high frequency sputtering method, a vacuum deposition method, an ion plating method, or the like. Further, when an organic conductive compound is selected as the material of the anode, it can be carried out according to a wet film forming method. In particular, in the present invention, it is preferable to use a wet film forming method from the viewpoint of increasing the area of the light emitting element and the productivity.

  The patterning of the anode may be performed by chemical etching such as photolithography, physical etching by laser, or the like. Further, the mask may be overlapped and vacuum deposition or sputtering may be used. Or printing method.

The thickness of the anode can be appropriately selected depending on the material and cannot be generally defined, but is usually 10 nm to 50 μm, and preferably 50 nm to 20 μm.
The resistance value of the anode is preferably 106Ω / □ (106Ω / sq) or less, and more preferably 105Ω / □ or less. In the case of 105Ω / □ or less, a large area light emitting device having excellent performance can be obtained by installing the bus line electrode of the present invention.
The anode may be colorless and transparent, colored and transparent, or opaque.

  The cathode usually has a function as a cathode (electrode) for injecting electrons into the light-emitting organic film and is substantially transparent to light, and has a shape, structure and size. There is no restriction | limiting in particular about etc., According to the use and objective of a light emitting element, it can select suitably from well-known electrodes.

  The structure of the cathode can be a single layer structure, but in order to achieve both the electron injecting property and the transparency, it can have a two-layer structure of a thin metal layer and a transparent conductive layer. Examples of the metal material used for the metal layer of the thin film include simple metals and alloys, and those having a work function of 4.5 eV or less are preferable. Specific examples include alkali metals (eg, Li, Na, K, Cs, etc.), alkaline earth metals (eg, Mg, Ca, etc.), gold, silver, lead, aluminum, sodium-potassium alloys, lithium-aluminum alloys, magnesium. -Rare earth metals such as silver alloys, indium, ytterbium, and the like. These may be used alone, but two or more can be suitably used in combination from the viewpoint of achieving both stability and electron injection.

Among these, alkali metals and alkalinity metals are preferable from the viewpoint of electron injection properties, and materials mainly composed of aluminum are preferable from the viewpoint of excellent storage stability.
The material mainly composed of aluminum is aluminum alone, or an alloy or mixture of aluminum and 0.01 to 10% by weight of alkali metal or alkaline earth metal (for example, lithium-aluminum alloy, magnesium-aluminum alloy, etc.) Say.

  The material of the thin film metal layer is described in detail in JP-A-2-15595 and JP-A-5-121172. The thickness of the metal layer of the thin film is preferably 1 nm to 50 nm. By setting the thickness to 1 nm or more, a thin film layer can be formed more uniformly. Moreover, the transparency with respect to light becomes more favorable by setting it as 50 nm or less.

As a material used for the transparent conductive layer in the case of a two-layer structure, the materials described in the anode can be suitably used as long as they are conductive and semiconducting and are transparent. Among them, for example, tin oxide doped with antimony or fluorine (ATO, FTO), tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), or the like is preferable.
The thickness of the transparent conductive layer is preferably 30 nm to 500 nm. By setting it to 30 nm or more, conductivity and semiconductivity can be more effectively maintained, and by setting it to 500 nm or less, productivity is improved.

  There is no restriction | limiting in particular in the formation method of the said cathode, Although it can carry out in accordance with a well-known method, in this invention, it is preferable to carry out in a vacuum apparatus. For example, the film according to a method appropriately selected in consideration of suitability with the material from among physical methods such as vacuum deposition, sputtering and ion plating, and chemical methods such as CVD and plasma CVD. Can be formed on top. For example, when a metal or the like is selected as the material for the cathode, one or more of them can be simultaneously or sequentially performed according to a sputtering method or the like.

  The cathode patterning may be performed by chemical etching such as photolithography, physical etching by laser, or the like. Further, vacuum deposition or sputtering may be used with a mask overlapped, or a lift-off method or the like. You may carry out by the printing method.

A dielectric layer made of the alkali metal or the alkaline earth metal fluoride may be inserted between the cathode and the light-emitting organic film with a thickness of 0.1 to 5 nm.
The dielectric layer can be formed by, for example, a vacuum deposition method, a sputtering method, an ion plating method, or the like.

  Specific examples of the structure of the organic EL structure of the present invention include anode / luminescent organic film / transparent cathode, anode / luminescent organic film / electron transport layer / transparent cathode, anode / hole transport layer / luminescent property. Organic film / electron transport layer / transparent cathode, anode / hole transport layer / luminescent organic film / transparent cathode, anode / luminescent organic film / electron transport layer / electron injection layer / transparent cathode, anode / hole injection layer / Examples include hole transport layer / luminescent organic film / electron transport layer / electron injection layer / transparent cathode.

The luminescent organic film used in the present invention is made of at least one organic luminescent material.
The organic light emitting material used in the present invention is not particularly limited, and any fluorescent compound or phosphorescent compound can be used. For example, fluorescent compounds include benzoxazole derivatives, benzimidazole derivatives, benzothiazol derivatives, styrylbenzene derivatives, polyphenyl derivatives, diphenylbutadiene derivatives, tetraphenylbutadiene derivatives, naphthalimide derivatives, coumarin derivatives, perylene derivatives. Perinone derivative, oxadiazol derivative, aldazine derivative, pyralidine derivative, cyclopentadiene derivative, bisstyrylanthracene derivative, quinacridone derivative, pyrrolopyridine derivative, thiadiazolopyridine derivative, styrylamine derivative, aromatic dimethylidene compound, 8-quinolino- Various metal complexes represented by metal complexes and rare earth complexes, polythiophene derivatives, polyphenylene derivatives, polyphenylene vinylene derivatives, poly Polymeric compounds such as fluorene derivatives. These can be used alone or in combination of two or more.

The phosphorescent compound is not particularly limited, but an orthometalated metal complex or a porphyrin metal complex is preferable.
Examples of the ortho-metalated metal complex include, for example, Akio Yamamoto, “Organic Metal Chemistry: Fundamentals and Applications”, pages 150 and 232, Hanabosha (published in 1982) and H. Yersin, “Photochemistry and Photophisics of Coodination”. Compounds "pages 71 to 77, pages 135 to 146, and a general term for compounds described in Springer-Verlag (published in 1987) and the like. The organic EL structure containing the orthometalated metal complex is advantageous in that it has high luminance and excellent luminous efficiency.

There are various ligands that form the ortho-metalated metal complex, which are also described in the above documents. Among them, preferred ligands include 2-phenylpyridine derivatives, 7,8- Examples include benzoquinoline derivatives, 2- (2-thienyl) pyridine derivatives, 2- (1-naphthyl) pyridine derivatives, and 2-phenylquinoline derivatives. These derivatives may have a substituent as necessary.
The orthometalated metal complex may have another ligand in addition to the ligand.

Orthometalated metal complexes used in the present invention are Inorg.Chem. 1991, 30, 1685., 1988, 27, 3464., 1994, 33, 545. Inorg.Chim.Acta 1991, 181, 245. J. Organomet. Chem. 1987, 335, 293. J. Am. Chem. Soc. 1985, 107, 1431. can do.
Among the orthometalated complexes, a compound that emits light from triplet excitons can be suitably used in the present invention from the viewpoint of improving luminous efficiency.
Of the porphyrin metal complexes, a porphyrin platinum complex is preferred.
Furthermore, the said phosphorescent compound may be used individually by 1 type, and may use 2 or more types together. In addition, the fluorescent compound and the phosphorescent compound may be used simultaneously. In the present invention, it is preferable to use the phosphorescent compound from the viewpoint of light emission luminance and light emission efficiency.

As the hole transport material used for the hole transport layer, both a low molecular hole transport material and a polymer hole transport material can be used, a function of injecting holes from the anode, a function of transporting holes. The material is not limited as long as it has any of the functions of blocking electrons injected from the cathode, and examples thereof include the following materials.
Carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, Hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidene compounds, porphyrin compounds, polysilane compounds, poly (N-vinylcarbazole) derivatives, aniline copolymers, thiophenes Oligomer, conductive polymer oligomer such as polythiophene, polythiophene derivative, polyphenylene derivative, polyphenylene vinylene derivative, polyfluorene Polymeric compounds such as derivatives.
These may be used individually by 1 type and may use 2 or more types together.
The content of the hole transport material is preferably 0 to 99.9% by weight of the organic EL structure, and more preferably 0 to 80% by weight.

The electron transport material used for the electron transport layer is not limited as long as it has either a function of transporting electrons or a function of blocking holes injected from the anode. Can be mentioned. Triazole derivatives, oxazole derivatives, oxadiazole derivatives, fluorenone derivatives, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, carbodiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives, naphthaleneperylene, etc. Metal complexes represented by the heterocyclic tetracarboxylic acid anhydrides, phthalocyanine derivatives, 8-quinolinol derivative metal complexes, metal phthalocyanines, metal complexes having benzoxazole or benzothiazol as ligands, and aniline copolymers , Thiophene oligomers, conductive polymer oligomers such as polythiophene, polymer compounds such as polythiophene derivatives, polyphenylene derivatives, polyphenylene vinylene derivatives, polyfluorene derivatives, etc. It can be mentioned.
As content of the said electron transport material, 0-99.9 weight% of an organic electroluminescent structure is preferable, More preferably, it is 0-80 weight%.

Moreover, you may employ | adopt a host compound as needed. The host compound is a compound having a function of causing energy transfer from the excited state to the fluorescent light emitting compound or the phosphorescent light emitting compound and, as a result, causing the fluorescent light emitting or phosphorescent light emitting compound to emit light. .
The host material is not particularly limited as long as it is a compound capable of transferring exciton energy to the light emitting material, and can be appropriately selected according to the purpose. Specifically, the carbazole derivative, triazole derivative, oxazole derivative, oxadiazole Derivative, imidazole derivative, polyarylalkane derivative, pyrazoline derivative, pyrazolone derivative, phenylenediamine derivative, arylamine derivative, amino-substituted chalcone derivative, styrylanthracene derivative, fluorenone derivative, hydrazone derivative, stilbene derivative, silazane derivative, aromatic third Amine compounds, styrylamine compounds, aromatic dimethylidene compounds, porphyrin compounds, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyrandioxy Derivatives, carbodiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives, heterocyclic tetracarboxylic anhydrides such as naphthaleneperylene, phthalocyanine derivatives, metal complexes of 8-quinolinol derivatives, metal phthalocyanines, benzoxazoles and benzothiazoles. Various metal complexes represented by metal complexes used as ligands, polysilane compounds, poly (N-vinylcarbazole) derivatives, aniline copolymers, thiophene oligomers, conductive polymer oligomers such as polythiophene, polythiophene derivatives, polyphenylene derivatives And polymer compounds such as polyphenylene vinylene derivatives and polyfluorene derivatives.

The said host compound may be used individually by 1 type, and may use 2 or more types together.
The content of the host compound in the organic EL structure is preferably 0 to 99.9% by weight, more preferably 0 to 99.0% by weight.

Moreover, an electrically inactive polymer binder can be used for the luminescent organic film of this invention as needed.
Examples of the electrically inactive polymer binder used as necessary include polyvinyl chloride, polycarbonate, polystyrene, polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, hydrocarbon resin, and ketone resin. Phenoxy resin, polyamide, ethyl cellulose, vinyl acetate, ABS resin, polyurethane, melamine resin, unsaturated polyester, alkyd resin, epoxy resin, silicone resin, polyvinyl butyral, polyvinyl acetate and the like.
When the light emitting layer contains the polymer binder, it is advantageous in that the light emitting layer can be easily applied and formed in a large area by a wet film forming method.

  The light-emitting organic film is formed by a wet process such as a dry film forming method such as a vapor deposition method or a sputtering method, a dipping method, a spin coating method, a dip coating method, a casting method, a die coating method, a roll coating method, a bar coating method, or a gravure coating method. A film can be suitably formed by any of a film method, a transfer method, a printing method, and the like.

In particular, in the case of coating formation by the wet film-forming method, the light-emitting organic film can be easily increased in area, and a light-emitting element having high luminance and excellent luminous efficiency can be obtained efficiently at low cost. It is advantageous.
In addition, selection of the kind of these film forming methods can be suitably performed according to the material of this luminescent organic film.
In the case of film formation by the wet film formation method, after film formation, drying can be performed as appropriate, and there are no particular restrictions on the drying conditions, but a temperature in a range that does not damage the applied and formed layer is adopted. can do.

When the light-emitting organic film is applied and formed by the wet film-forming method, a binder resin can be added to the light-emitting organic film.
In this case, as the binder resin, polyvinyl chloride, polycarbonate, polystyrene, polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, hydrocarbon resin, ketone resin, phenoxy resin, polyamide, ethyl cellulose, vinyl acetate, ABS resin, polyurethane, melamine resin, unsaturated polyester, alkyd resin, epoxy resin, silicone resin, polyvinyl butyral, polyvinyl acetal and the like can be mentioned.
These may be used individually by 1 type and may use 2 or more types together.

  When the luminescent organic film is formed by a wet film forming method, the solvent used for adjusting the coating solution by dissolving the material of the luminescent organic film is not particularly limited, and the hole transport material , The ortho-metalated complex, the host material, the polymer binder and the like can be selected as appropriate, for example, halogen solvents such as chloroform, carbon tetrachloride, dichloromethane, 1,2-dichloroethane, chlorobenzene, Ketone-type additives such as acetone, methyl ethyl ketone, diethyl ketone, n-propyl methyl ketone, cyclohexanone, aromatic solvents such as benzene, toluene, xylene, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl propionate, propionate Ester solvents such as ethyl acetate, γ-butyrolactone, diethyl carbonate Tetrahydrofuran, ether solvents such as dioxane, dimethyl formamide, amide solvents such as dimethylacetamide, dimethyl sulfoxide, water and the like.

In addition, there is no restriction | limiting in particular as solid content with respect to the solid content solvent in the said coating liquid, The viscosity can also be selected arbitrarily according to the wet film forming method.
In addition, when the wet film forming method is used, it is often a solvent-soluble film, and it is difficult to make a multilayer. In this case, a transfer method can also be preferably used.

There is no restriction | limiting in particular as said other layer, According to the objective, it can select suitably, For example, a protective layer etc. are mentioned.
Suitable examples of the protective layer include those described in JP-A-7-85974, JP-A-7-192866, JP-A-8-22891, JP-A-10-275682, JP-A-10-106746, and the like. It is mentioned in.
The shape, size, thickness, and the like of the protective layer can be selected as appropriate. As the material, a material capable of deteriorating the light-emitting element such as moisture or oxygen is allowed to enter or transmit the light-emitting element. If it has the function to suppress, there will be no restriction | limiting in particular, For example, silicon oxide, silicon dioxide, germanium oxide, germanium dioxide etc. are mentioned.

  The method for forming the protective layer is not particularly limited. For example, the vacuum deposition method, the sputtering method, the reactive sputtering method, the molecular send epitaxy method, the cluster ion beam method, the ion plating method, the plasma polymerization method, and the plasma CVD method. Laser CVD method, thermal CVD method, coating method, and the like.

The light-emitting element of the present invention emits light by applying a direct current (which may include an alternating current component if necessary) voltage (usually 2 to 40 volts) or a direct current between the anode and the cathode. Can be obtained.
Regarding the driving of the light-emitting element of the present invention, JP-A-2-148687, JP-A-6-301355, JP-A-5-29080, JP-A-7-134558, JP-A-8-234658, and JP-A-8-240447, US The methods described in Japanese Patent Nos. 5828429 and 6023308, Japanese Patent No. 2784615 and the like can be used.

(3) Adhesive The space between the first laminated film and the second laminated film is filled with an adhesive. Adhesives are required to seal by adhering gas barrier laminated films to ensure gas barrier properties. For this purpose, not only the gas barrier property of the adhesive itself after curing, but also the permeation of gas at the adhesive interface with the film must be prevented. Furthermore, as a flexible organic EL element, the gas barrier property should not be lowered by bending resistance, that is, cracks, peeling, and the like.
Further, gas should not be generated during curing, which should adversely affect the organic EL structure. This reduction in the so-called outgas amount is an extremely important factor in selecting an adhesive for organic EL.

  As an adhesive for organic EL, an adhesive generally used for semiconductor encapsulation is used. From the viewpoints of high productivity, energy saving, and environmental properties, a photo-curing type adhesive having characteristics of short-time curing, no solvent, and one-component property is usually used. As photo-curing adhesives, there are radical polymerization types and cationic polymerization types, but radical polymerization types are excellent in thermal stability and curing speed, but there is concern about outgassing due to components such as monomers, and large thermal shrinkage. Due to the drawbacks, the cationic polymerization type is often used for organic EL applications.

  As a light source for causing photopolymerization, UV light is generally used in an organic EL element using a normal glass film. However, when a transparent resin film is used as a base film, the UV absorption of the resin film is reduced. For this reason, the UV light amount must be extremely high, and therefore, it is preferable to design so as to polymerize with visible light.

An epoxy adhesive is generally used as the cationic curable adhesive. The characteristics of the epoxy system are that there is no inhibition of curing by oxygen, various reactive groups can be used, and the structure can be variously improved depending on the application. Since an epoxy resin is cured by a ring-opening reaction, it is a great merit that no volatile matter is generated during curing. Further, it is solidified from a state excellent in fluidity and has excellent handling properties because it has little cure shrinkage. The cured epoxy resin has a cross-linked structure with a strong and stable bond, and therefore has excellent mechanical properties, thermal properties, water resistance, chemical resistance, electrical properties, and the like.
As the epoxy resin used for the epoxy adhesive, any known type such as a glycidyl ether type, a glycidyl ester type, a glycidyl amine type, and an oxidized type can be used, but a glycidyl ether type is preferable. Among the glycidyl ether types, alicyclic epoxy resins are more preferable.
The following are used as examples of the epoxy resin.

However, in general, epoxy resins have relatively low polymerization reactivity, and have drawbacks as flexible film adhesives, which are hard but brittle.
Various attempts have been made for a long time to solve the disadvantage of being particularly brittle. Although modification with elastomers such as silicone and urethane is actively performed, generally there are many cases where heat resistance and gas barrier properties are lowered, and it is difficult to obtain sufficient performance by itself.
In recent years, for example, introduction of a liquid crystal structure and polymer alloy with other polymer materials have been performed. In particular, the toughening technique using a fine particle-dispersed epoxy resin using a silyl group-terminated oligomer is particularly excellent.
Recently, in order to impart heat resistance, a composeran (manufactured by Arakawa Chemical Industries) in which a polyalkoxysilane is grafted to a heat-sensitive part of an epoxy resin is also preferable.

  In addition, the most effective improvement in water vapor permeability is to reduce hydrophilic groups such as hydroxyl groups contained in the cured resin, but this significantly reduces the crosslink density, thus reducing the mechanical properties. Or heat resistance may be impaired. As a method for solving this problem, a method having a rigid skeleton such as dicyclopentadiene in the molecular structure of the epoxy resin is preferable.

It is also preferable to mix an inorganic filler with the epoxy resin mainly for imparting toughness and reducing the thermal expansion coefficient (heat resistance). As inorganic filler, fine particles such as calcium carbonate, strontium carbonate, alumina, silica, titanium oxide, kaolin, barium sulfate, zinc oxide, aluminum hydroxide, talc, mica, wollastonite, sepiolite, smectite, glass flakes, etc. are added. can do.
Furthermore, in order to improve toughness and thermal expansion, a method of dispersing silica in an epoxy network using a sol-gel method is also preferable.

As an attempt to greatly improve the curing reaction rate of an epoxy resin, a photocurable resin having an oxetane ring instead of an epoxy ring is disclosed in JP-A-7-173279. Oxetane resin not only has a high polymerization rate, but also has a high crosslink density, so that a tough cured product can be obtained. Therefore, it is excellent as a base material for organic EL adhesives.
As the oxetane resin, a preferable compound includes a compound represented by the following formula (2).

Formula (2)

Here, in Formula (2), m is an integer of 2-4, Z is an oxygen atom or a sulfur atom. R ³ is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, or a butyl group), and a fluoroalkyl group having 1 to 6 carbon atoms, an allyl group, An aryl group or a furyl group.
R ⁴ includes, for example, a linear or branched alkylene group having 1 to 12 carbon atoms and a linear or branched poly (alkyleneoxy) group represented by the following formula (3).

Formula (3)

In the above formula (3), R ⁵ is a lower alkyl group such as a methyl group, an ethyl group or a propyl group.

R ⁴ is also a polyvalent group selected from the group consisting of the following formulas (4), (5) and (6).

Formula (4)

In Formula (4), n is 0 or an integer of 1-10. R ⁶ and R ⁷ are each an alkyl group having 1 to 10 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, or a butyl group), and * is linked to the following formula (7).

Formula (7)

In the formula (7), j is 0 or an integer of 1 to 10, and R ⁸ is alkyl having 1 to 10 carbon atoms. R ⁹ is an alkyl group having 1 to 10 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, or a butyl group).

Formula (5)

In Formula (5), R ² represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, or a butyl group), a halogen atom, a nitro group, A cyano group, a mercapto group, a lower alkyl carboxylate group or a carboxyl group;

Formula (6)

In the formula (6), R ¹⁰ is an oxygen atom, a sulfur atom, NH, SO, SO ₂ , CH ₂ , C (CH ₃ ) ₂ or C (CF ₃ ) ₂ .

In the present invention, in the above formula (2), R ³ is preferably a lower alkyl group (carbon number: 1 to 6), more preferably an ethyl group. R ⁴ is preferably a group in which R ² is a hydrogen atom in the formula (5), a hexamethylene group, or a group in which R ⁵ is an ethyl group in the formula (3). Z is preferably an oxygen atom. In the formula (7), R ⁸ and R ⁹ are preferably methyl groups.

  In the present invention, it is preferable to use a compound having two or more oxetanyl groups in the molecule. Preferable specific examples include compounds of formula (8) and formula (9).

Formula (8)

In the formula (8), r is an integer of 2 to 100, and R ¹¹ is an alkyl group having 1 to 4 carbon atoms or a trialkylsilyl group. R ¹² is (an alkyl group having 1 to 10 carbon atoms), and R ¹³ is (an alkyl group having 1 to 6 carbon atoms). Formula (8) is preferably a compound of formula (10).

Formula (10)

In Formula (10), Y ¹ , Y ² , and Y ³ are each a hydroxyl group, an alkoxy group having 1 to 4 carbon atoms, or another atom of Formula (10) when Y ^{1 to} Y ³ are oxygen atoms. Y ^{1 to} Y ³ are indicated. R ¹³ has the same meaning as in formula (8). Specific examples of formula (10) include silsesquioxane represented by formula (11).

Formula (11)

In the formula, R represents a group represented by the formula (12).

（９）
Formula (9)

(9)

In the formula (9), R ¹⁴ represents (an alkyl group having 1 to 6 carbon atoms).

The silsesquioxane compound exemplified by the formula (11) is most preferably used from the viewpoints of adhesiveness, low thermal deformation property of the low volume shrinkage layer before and after curing, and heat resistance. These monomers may be used alone as appropriate, or two or more monomers may be arbitrarily mixed and used.
Moreover, it is possible to arbitrarily adjust the curing rate by mixing the oxetane resin with the epoxy resin at an arbitrary ratio.

The photo-curing resin adhesive may include a photo-curing latent curing agent that initiates a curing reaction using light as a trigger. In the case of a cationic polymerization type epoxy or oxetane resin, a photoacid generator is usually preferred.
As the photoacid generator, aryl diazonium salts, diaryl iodonium salts and the like are known, and triarylsulfonium salts are the most common.
Moreover, the combined use of the compound which produces | generates a photoradical as a sensitizer is preferable. As the sensitizer, aromatic ketone, phenothiazine, diphenylanthracene, rubrene, xanthone, thioxanthone derivative, chlorothioxanthone and the like are used, and thioxanthone derivatives are preferable.

In addition to the inorganic particles and curing agent described above, a curing accelerator, various coupling agents, antifoaming agents, low stress agents, rubber particles, pigments, and the like can be added as appropriate to the adhesive of the present invention. .
An adhesive composition is obtained by uniformly mixing these additives into the base resin for adhesive using a stirrer. Stirring is usually performed at room temperature, but if it is accompanied by heat generation, it may be cooled, and if the viscosity is high and stirring efficiency is low, it may be heated, but in the case of a one-pack type, it is usually preferable to cool.

Before entering the bonding operation, it is preferable to remove dirt on the bonded portion or perform various surface treatments. For washing, water, an aqueous solution such as an aqueous surfactant solution, alcohols such as ethyl alcohol and isopropyl alcohol, a fluorinated solvent such as HCFC-125.225, and a hydrocarbon solvent such as isoparaffin and naphthene are usually used. Alcohols are preferred from the viewpoints of detergency and drying.
Polishing is also used as a method for mechanically removing foreign substances. For polishing, sand paper, buff, belt sander, sand blast, wire brush or the like is used, but a method by jetting high pressure liquid is also preferable.
There is also a method in which the surface to be bonded is treated with a chemical such as an acid, alkali, or oxidizing agent to remove dirt and simultaneously make the surface hydrophilic.
The most common method is to modify the surface using an active gas such as corona, plasma or UV ozone. This is also to remove dirt, but mainly to introduce oxygen to the surface.
The cleaning, polishing, chemical treatment, and active gas treatment described above may be performed alone, but the effect can be further enhanced by combining them.

  As a method of applying the adhesive of the present invention to a necessary portion, a manual method such as a spatula, a trowel, a brush, an oiler, a dipping, a dispenser, an applicator, a screen printing, a pin transfer, a spray, a roll coat, a flow coat Such a method by machine work is used, but a method by machine work is adopted in a normal process.

When an organic EL device made on a transparent resin film having ultraviolet absorption is sealed with an adhesive, it is advantageous to use a visible light curing system. In addition, it is advantageous in terms of preventing the organic EL structure from being damaged by exposure to ultraviolet light, and further eliminates the point that the inside is hard to be cured by the ultraviolet absorption of the adhesive itself. This system is also excellent in that it can be given.
Radical polymerization initiators by visible light include hydrogen abstraction types such as aromatic ketones, camphorquinones, ketocoumarins, halogen compounds such as tris (trichloromethyl) triazine, organic peroxides such as benzoyl peroxide, hexaarylbisimidazole compounds Boron compounds such as cyanine borate and organometallic compounds such as N-phenylglycine and bispentadienyltitanium-di (pentafluorophenyl) are known. These radical generators can also be used for acrylic photo-curing adhesives, but in combination with the above-mentioned photo-curing latent curing agents, they can be applied to photo-cationic polymerization type epoxy resins and oxetane resins. preferable.

  When a photopolymerization initiator is used, it is started by irradiation with active energy rays. When irradiating with ultraviolet light, various light sources can be used, such as curing with mercury arc lamp, xenon arc lamp, fluorescent lamp, carbon arc lamp, tungsten-halogen radiation lamp and irradiation light by sunlight. . For irradiation with visible light, an ultrahigh pressure mercury lamp, a metal halide lamp, a halogen lamp, a xenon lamp, sunlight, or the like can be used.

  In the present invention, the visible light curable adhesive is substantially cured by visible light of 400 nm to 700 nm, but may be used in combination with ultraviolet light or infrared light. A visible light curable adhesive is one in which 50% or more of the light energy required for curing is given by visible light.

The adhesive may contain the following moisture absorbent and inert liquid. The packed bed may contain inorganic particles in order to improve mechanical properties.
The moisture absorbent is not particularly limited, but for example, barium oxide, sodium oxide, potassium oxide, calcium oxide, sodium sulfate, calcium sulfate, magnesium sulfate, phosphorus pentoxide, calcium chloride, magnesium chloride, copper chloride, fluorine Examples thereof include cesium fluoride, niobium fluoride, calcium bromide, vanadium bromide, molecular sieve, zeolite, and magnesium oxide. The inert liquid is not particularly limited, and examples thereof include paraffins, liquid paraffins, fluorinated solvents such as perfluoroalkane, perfluoroamine, and perfluoroether, chlorinated solvents, and silicone oils. .

  The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

(Preparation of sample A)
Hereinafter, a description will be given with reference to FIG.
<Preparation of base film>
The resin compound (I) shown below was dissolved in a dichloromethane solution so as to be 15% by mass and cast on a stainless steel band by a die coating method.
Next, the first film is peeled off from the band and dried until the residual solvent concentration becomes 0.08% by mass. Then, both ends are trimmed, knurled, wound up, and the substrate film 1 having a thickness of 100 μm is obtained. Produced.

Resin Compound (I)

<Film formation of the first inorganic layer>
A commercially available roll-to-roll type sputtering apparatus was used. Specifically, Si was set as a target, and a pulse application type DC power source was prepared as a discharge power source. The vacuum pump was started and the inside of the vacuum chamber was evacuated to the 10-4 Pa level, and argon was introduced as a discharge gas and oxygen was introduced as a reaction gas. When the atmospheric pressure was stabilized, the discharge power source was turned on, plasma was generated on the Si target with a discharge power of 5 kW, and the film formation pressure was reduced to 0.030 Pa, and then the sputtering process was started. The voltage value at this time was 610V. Using this voltage value as a set value, the controller increases the oxygen flow rate when the discharge voltage is smaller than the set value in the transition region, and decreases the oxygen flow rate when the discharge voltage is larger than the set value in the transition region. The discharge voltage was controlled to be constant by giving a command to the piezoelectric element valve unit. Thus, the 1st inorganic layer 2 which is a 50-nm-thick SiOx layer was formed on the base film. Sample 1A in this state was obtained.

<Film formation of first resin layer>
12.37 g of 3-ethyl-3- [3- (triethoxysilyl) propyloxymethyl] oxetane synthesized by the method described in paragraph Nos. [0056] to [0057] of JP-A-2000-264969, tetramethyl hydroxide A 10% aqueous solution of ammonium (1.05 g), water (1.14 g), and 1,4-dioxane (300 mL) were heated to reflux with stirring for 16 hours. Next, 200 mL of the solvent portion was distilled off under reduced pressure, the reaction system was concentrated, and reacted for 6 hours. Thereafter, the solvent and the like were distilled off under reduced pressure, and the solvent was replaced with 200 mL of toluene. Thereafter, it was washed with water and dehydrated to obtain the desired product. It was confirmed by GPC and NMR that an oxetanyl group-containing silsesquioxane compound having an average molecular weight (Mn) of about 2,000 was obtained.

A coating composition obtained by adding 2 parts of diphenyl-4-thiophenoxysulfonium hexafluoroantimonate as a polymerization initiator to 100 parts of the silsesquioxane compound was applied on the sample (1A), and the film thickness was about 4 μm. (First resin layer 3). The obtained base material was irradiated with ultraviolet rays at an irradiation intensity of 70 mJ / cm ² in the atmosphere using an ultraviolet irradiation device (Harrison Toshiba Lighting Co., Ltd., Toscure 401) using a 395 W high-pressure mercury lamp. Curing was performed by irradiating the composition with a sufficient amount of UV irradiation (2000 mJ / cm ² , confirmed by FT-IR). The sample in this state was designated as 2A.

<Film formation of the second inorganic layer>
The 2nd inorganic layer 4 was installed by the completely same method as film forming of the 1st inorganic layer except having formed into a film on 2A instead of on a substrate. The sample in this state was 3A.
<Film formation of second resin layer>
The 2nd resin layer 5 was installed by the completely same method as film forming of the 1st resin layer except having formed into film on 3A instead of on 1A. The sample in this state was designated as 4A. 4A corresponds to an example of a gas barrier laminate film as referred to in the present invention.
<Surface treatment of gas barrier laminate film>
After the gas barrier laminate film 4A was washed with IPA, UV-ozone surface treatment was performed. The gas barrier laminate film thus obtained is designated as 5A.

<Production of organic EL element>
The gas barrier laminate film (5A) was introduced into a vacuum chamber, and a transparent electrode 6 made of an IXO thin film having a thickness of 0.2 μm was formed by DC magnetron sputtering using an IXO target. An aluminum lead wire was connected from the transparent electrode (IXO) to form a laminated structure.

The surface of the transparent electrode was spin-coated with an aqueous dispersion of polyethylene dioxythiophene / polystyrene sulfonic acid (BAYTRON P: solid content: 1.3 mass%) manufactured by BAYER, and then vacuum-dried at 150 ° C. for 2 hours to obtain a thick A hole-transporting organic thin film layer 7 having a thickness of 100 nm was formed. This is called film X.
On the other hand, a coating liquid for a light-emitting organic film layer having the following composition on one side of a temporary support 8 made of polyethersulfone having a thickness of 188 μm (Sumilite FS-1300, manufactured by Sumitomo Bakelite Co., Ltd.) was applied to a spin coater. The luminescent organic film layer 9 having a thickness of 13 nm was formed on the temporary support by applying the film and drying at room temperature. This is designated as transfer material Y.

Composition of coating solution for light-emitting organic film layer Polyvinylcarbazole (Mw = 63000, manufactured by Aldrich): 40 parts by mass Tris (2-phenylpyridine) iridium complex (orthometalated complex): 1 part by mass Dichloroethane: 3200 parts by mass

  The upper surface of the organic thin film layer of the film X is overlaid so that the light emitting organic film layer side of the transfer material Y is in contact, and heated and pressurized at 160 ° C., 0.3 MPa, 0.05 m / min using a pair of heat rollers, The light-emitting organic film layer was formed on the upper surface of the film X by peeling off the temporary support. This is called film XY.

  Further, a patterned vapor deposition mask (a mask with a light emitting area of 5 mm × 5 mm) is placed on another gas barrier laminate film (5A) cut to 25 mm square, and a reduced pressure atmosphere of about 0.1 MPa Al was vapor-deposited therein to form an electrode 10 having a thickness of 0.3 μm. Using a LiF target, LiF11 was deposited in the same pattern as the Al layer by DC magnetron sputtering to a film thickness of 3 nm. An aluminum lead wire was connected from the Al electrode to form a laminated structure. A coating solution for an electron transporting organic thin film layer having the following composition is coated on the obtained laminated structure with a spin coater coating machine and dried in a vacuum at 80 ° C. for 2 hours, whereby an electron transporting property having a thickness of 15 nm is obtained. The organic thin film layer 12 was formed on LiF. This is referred to as film Z.

Electron transportable organic thin film layer coating solution Polyvinyl butyral 2000L (Mw = 2000, manufactured by Denki Kagaku Kogyo Co., Ltd.):
10 parts by mass 1-butanol: 3500 parts by mass An electron transporting compound having the following structure: 20 parts by mass

<Overlay>
In the glow box, the film XY and the film Z were used so that the electrodes face each other with the light-emitting organic film layer 9 interposed therebetween. During the superposition, the following adhesive (II) containing glass spheres having a diameter of 5 μm as spacers was uniformly applied to the periphery of the surface of the film XY with a dedicated dispenser. After the films Z are stacked, uniformly pressed and bonded, UV irradiation is performed using an ultraviolet irradiation device (Toscure 401 manufactured by Harrison Toshiba Lighting Co., Ltd.) using a 395 W high-pressure mercury lamp so that the integrated light amount is 6000 mJ / cm ^2. And cured to obtain an organic EL device sample (A) of the present invention.
The atmosphere in the glow box was a nitrogen gas atmosphere having a water concentration of 30 ppm or less and an oxygen concentration of 30 ppm or less.

<Preparation of adhesive (II)>
The adhesive (II) of the present invention was blended with the following composition.
Adhesive resin (I) Silsesquioxane compound containing oxetanyl group
(Synthesis by the same method as described in the formation of the barrier resin layer) 100 g
Diphenyl-4-thiophenoxysulfonium hexafluoroantimonate
5g
Irgacure 184 (Ciba Gigi) 1g
Methyl hydroquinone 0.05g
ST86PA (Toray Dow Corning Silicone) 0.01g

(Preparation of Sample B of the Invention)
In Sample A of the present invention, the gas barrier laminate film (4A) was produced in the same manner as Sample A of the present invention, except that the UV-plasma treatment was not performed and it was used as it was in the next step instead of (5A).

(Preparation of Sample C of the Invention)
In this invention sample A, the adhesive which mix | blended di [1-ethyl (3-oxetanyl)] methyl ether (the Toagosei make, OXT-221) instead of adhesive resin (I) in adhesive agent (II). It was produced in the same manner as Sample A of the present invention except that (III) was used.

(Preparation of Sample D of the Invention)
In this invention sample A, it produced similarly to this invention sample A except having used the following adhesive agent (IV) instead of adhesive agent (II).

<Preparation of adhesive (IV)>
The following components were mixed to prepare an adhesive (IV).
50 g silsesquioxane compound containing oxetanyl group
Epicron 1050 (Dainippon Ink) 20g
16H-DGE (Sakamoto Yakuhin) 30g
PHOTOINITIATOR-2074 (Rhodia) 1.0g
L-7604 (Nihon Unicar) 0.2g

(Preparation of comparative sample E)
In this invention sample A, it produced similarly to the sample A except having used XNR5493 by Nagase ChemteX as an adhesive agent instead of adhesive agent (II).

(Preparation of comparative sample F)
In the present invention sample A, in place of the gas barrier laminate film (5A), in the state of the sample (1A) in which only the first inorganic layer was formed on the base film, except that the organic EL structure was formed thereon. It was produced in the same manner as Sample A.

(Preparation of comparative sample G)
In Sample A of the present invention, instead of the gas barrier laminate film (5A), it was prepared in the same manner as Sample A except that only the first resin layer was formed on the base film and the organic EL structure was formed between them. did.

(Preparation of comparative sample H)
A transparent barrier film VC100 manufactured by Toyobo Co., Ltd. was used in place of the gas barrier laminate film (5A) of Sample A of the present invention, and it was prepared in the same manner as Sample A except that an organic EL structure was formed therebetween.

  The physical properties of the adhesive and gas barrier laminate film related to the present invention were measured by the following methods.

<Measurement of water vapor permeability of adhesive>
Each adhesive before curing was dissolved in THF and cast on a Teflon plate (Teflon: registered trademark) by a die coating method so as to have a thickness of 100 μm after drying.
Next, the film-like adhesive was peeled off from the Teflon plate and dried until the residual solvent concentration was 0.05% by mass to obtain an adhesive film. This adhesive film is cured by irradiating with ultraviolet rays using an ultraviolet irradiation device (Harrison Toshiba Lighting Co., Ltd., Toscure 401) using a 395 W high-pressure mercury lamp so that the integrated light quantity becomes 6000 mJ / cm ² , and cured adhesive film Was made.
Using this cured adhesive film, the water vapor transmission rate was determined. The water vapor transmission rate was measured by the infrared absorption method (MOCON method).
Similarly, the water vapor transmission rate of the gas barrier laminate film and the base film equivalent thereto were also measured.

<Measurement of cure shrinkage of adhesive>
When an adhesive is applied with a thickness of 150 μm to the free end of a 300 μm thick polystyrene plate that is fixed only on one side, and then irradiated with ultraviolet light to 6000 mJ / cm ² , the adhesive is cured. Due to shrinkage, the entire polystyrene board warps. The warped displacement was measured with a laser displacement type, and the shrinkage rate was calculated from the warped amount.

<Contact angle measurement of water>
The contact angle of pure water was measured at 25 ° C. for the gas barrier laminate film, the base film conforming thereto, and the cured adhesive film. A contact angle meter CA-X manufactured by Kyowa Interface Science was used to measure the contact angle.

(Sample evaluation results)
The physical property results relating to the inventive sample and the comparative sample are shown in Table 1 below.

In Table 1, Vb is a water vapor transmission rate of the substrate film at 40 ° C. and a relative humidity of 90%, and the unit is g / m ² · day. Va is a water vapor transmission rate of the adhesive film at 40 ° C. and a relative humidity of 90%, and its unit is g / m ² · day. θb is the contact angle of water at 25 ° C. and 60% with respect to the film, and its unit is degrees. θa is the contact angle of water at 25 ° C. and 60% with respect to the adhesive film, and its unit is degrees. αa is the curing shrinkage rate of the adhesive, and its unit is%. Further, <in the table indicates that it is smaller than the displayed number.

(Aging performance evaluation of organic EL elements)
These organic EL elements were installed in an environment of 50 ° C. and 90% relative humidity, connected to an AC power supply of 100 V and 400 Hz, continuously lit, and the change in luminance was measured. The luminance immediately after the start of the experiment was taken as 100%, and the luminance after 100 hours and after 1000 hours was expressed as%.
The evaluation results of aging are shown in Table 2 below. It has been clarified that the life of the organic EL element can be greatly extended by using a gas barrier laminate film and keeping the water vapor permeability of the adhesive low. Moreover, it turns out that a lifetime can be further extended by adjusting the contact angle of the water with respect to a film and an adhesive agent. It can be seen that keeping the curing shrinkage rate of the adhesive low is a demand for stability over time.

The schematic of the film produced in the Example of this invention is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base film 2 1st inorganic layer 3 1st resin layer 4 2nd inorganic layer 5 2nd resin layer 6 Transparent electrode 7 Hole transportable organic thin film layer 8 Temporary support body 9 Luminescent organic film layer 10 AL electrode 11 LiF
12 Electron transporting organic thin film layer

Claims (4)

At least a first laminated film, a second laminated film, and an adhesive that seals between the first laminated film and the second laminated film,
The first laminated film has a first gas barrier laminated film and a light emitting organic film including an electrode and an organic light emitting material provided on the first gas barrier laminated film,
The second laminated film includes a second gas barrier laminated film and an electrode provided on the second gas barrier laminated film, and is close to the luminescent organic film of the first laminated film. Is placed opposite the side,
The first gas barrier laminate film and the second gas barrier laminate film are respectively a base film, at least one inorganic layer and at least one resin layer provided on the base film. Consists of
An organic EL device having a water vapor transmission rate of 5 g / m ² · day or less at 40 ° C. and a relative humidity of 90% when the film thickness of the adhesive is 100 μm. The contact angle with water at 25 ° C. and a relative humidity of 60% of the surface of the first laminated film in contact with the adhesive and the surface of the second laminated film in contact with the adhesive, Both are in the range of 0 to 50 degrees, and the contact angle with water at 25 ° C. and 60% relative humidity after curing of the adhesive is in the range of 0 to 80 degrees. The organic EL device according to claim 1. The organic EL element according to claim 1, wherein a shrinkage rate accompanying the curing of the adhesive is 5% or less. The organic EL element according to claim 1, wherein the adhesive is a visible light curable type.

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