JP6812429B2 - Light extraction film and organic electroluminescence light emitting device - Google Patents

Description

The present invention relates to a light extraction film having a light scattering layer and an organic electroluminescence light emitting device including the light extraction film.

An organic electroluminescence element using electroluminescence (hereinafter, also simply referred to as EL), which is an organic material, is a thin-film type completely solid element capable of emitting light at a low voltage of several V to several tens V, and has high brightness. It has many excellent features such as high luminous efficiency, thinness, and light weight. For this reason, organic EL using a gas barrier film having a gas barrier layer on a thin and lightweight resin base material as a surface emitter such as a backlight for various displays, a display board for signboards and emergency lights, and an illumination light source, in particular in recent years. The element is attracting attention.

In such an organic EL device, it has been proposed to use a functional laminated film having a light scattering layer and a gas barrier layer as a base material of the organic EL device in order to further improve the luminous efficiency (for example, Patent Documents). 1. See Patent Document 2). However, when an organic layer or the like is formed on such a base material, the particles constituting the light scattering layer are separated during the transportation of the base material and mixed as foreign matter in the organic EL element to cause a failure such as a dark spot. It may occur.

Therefore, in order to improve the reliability of the organic EL element, a technique has been proposed in which a gas barrier film having an auxiliary barrier property is attached to the light emitting surface side of the organic EL element after the organic EL element is manufactured (for example,). See Patent Document 3). Further, in order to increase the luminous efficiency of the organic EL element, a technique has been proposed in which a light extraction film is attached to the light emitting surface side of the organic EL element after the production of the organic EL element to improve the brightness (for example,). See Patent Document 4).

Japanese Unexamined Patent Publication No. 2011-251460 JP-A-2015-88322 International Publication No. 2008/059925 JP 2015-170696

However, in order to obtain both the light extraction efficiency and the gas barrier property, when both the gas barrier film described in Patent Document 3 and the light extraction film described in Patent Document 4 are bonded together, the entire film is formed. The thickness of the film is increased, and the barrier layer of the cut surface is likely to be cracked by cutting the individual panels, and the sealing property of the organic EL element is lowered. On the other hand, in a configuration in which a plurality of films are bonded together, if the thickness of each layer is reduced in order to suppress the overall thickness, the laminated film will be warped (curled), resulting in reduced workability.

In order to solve the above-mentioned problems, the present invention provides an optical extraction film capable of suppressing a decrease in reliability and a decrease in workability, and an organic electroluminescence light emitting device.

The light extraction film of the present invention has a base material, a gas barrier layer formed on one surface of the base material, a light scattering layer formed on the other surface of the base material, and an adhesive formed on the gas barrier layer. With a layer, the thickness of the base material is 10 μm or more and 60 μm or less, and the thickness of the pressure-sensitive adhesive layer is 1 time or more and 3 times or less the thickness of the light scattering layer.
Further, the organic electroluminescence device of the present invention includes the above-mentioned light extraction film and an organic electroluminescence device.

According to the present invention, it is possible to provide a light extraction film capable of suppressing a decrease in reliability and a decrease in workability, and an organic electroluminescence light emitting device.

It is a figure which shows the structure of the light extraction film. It is a figure which shows the structure of the organic EL light emitting device.

Hereinafter, examples of embodiments for carrying out the present invention will be described, but the present invention is not limited to the following examples.
The explanation will be given in the following order.
1. 1. Form of light extraction film 2. Embodiment of an organic electroluminescence light emitting device

<1. Form of light extraction film>
Hereinafter, specific embodiments of the light extraction film will be described.
FIG. 1 shows a schematic configuration of a light extraction film. In the light extraction film 10 shown in FIG. 1, a gas barrier layer 12 is formed on one surface of the base material 11, and a light scattering layer 13 is formed on the other surface. Further, on the surface of the gas barrier layer 12, the pressure-sensitive adhesive layer 14 is formed on the surface opposite to the base material 11 (hereinafter, on the gas barrier layer 12).

Such a light extraction film 10 is used by being attached to an exterior body on the light extraction side of an electronic device such as a light emitting element by using the pressure-sensitive adhesive layer 14. By laminating the light extraction film 10, it is possible to reduce the reflection inside the light emitting element and improve the light extraction efficiency of the light emitting element.

Further, in the light extraction film 10 having the above structure, the thickness of the base material 11 is 10 μm or more and 60 μm or less, and the thickness of the pressure-sensitive adhesive layer 14 is 1 time or more and 3 times or less the thickness of the light scattering layer 13. The thickness of the base material 11 has a great influence on the total thickness of the light extraction film 10. Further, the relationship between the thickness of the pressure-sensitive adhesive layer 14 and the thickness of the light scattering layer 13 has a great influence on the action of suppressing the warp of the light extraction film 10.

Further, in the light extraction film 10, the base material 11 has a thickness in the above range, and the thickness of the pressure-sensitive adhesive layer 14 and the thickness of the light scattering layer 13 have the above relationship, so that the warp (curl) of the light extraction film 10 is increased. The occurrence can be suppressed. As described above, if the light extraction film 10 is too thin, the light extraction film 10 is warped, and work is performed during the manufacturing process of the light extraction film 10 or when the light extraction film 10 is applied to a light emitting element or the like. The sex is reduced. On the other hand, in the light extraction film 10, the occurrence of warpage (curl) can be suppressed by designing each layer to the above thickness, and the light extraction film 10 can be produced or the light extraction film 10 is used. In the production of electronic devices and the like, deterioration of workability can be suppressed.

In particular, in the light extraction film 10 having the above structure, the thickness of the light scattering layer 13 is preferably 5 μm or more and 30 μm or less. The overall thickness of the light extraction film 10 is preferably 25 μm or more and 110 μm or less, and more preferably 40 μm or more and 80 μm or less. Further, the thickness of the pressure-sensitive adhesive layer 14 is preferably 10 μm or more and 30 μm or less. When the thickness of the light scattering layer 13 and the thickness of the pressure-sensitive adhesive layer 14 are within the above ranges, the deterioration of reliability is suppressed by suppressing the overall thickness of the light extraction film 10, and the workability is improved by suppressing warpage. Is obtained more prominently.

In the light extraction film 10, a gas barrier layer 12, a light scattering layer 13, and an adhesive layer 14 are provided on the base material 11 of one layer. Therefore, the thickness of the entire light extraction film 10 can be suppressed as compared with the case of using two films, which are a conventionally known gas barrier film and a light extraction film.

As a specific example of the conventional structure, a gas barrier film composed of a base material, a gas barrier layer and an adhesive layer and a light extraction film composed of a base material and a light scattering layer are bonded by an adhesive layer [light scattering layer / The composition of the base material / pressure-sensitive adhesive layer / base material / gas barrier layer / pressure-sensitive adhesive layer] is known. On the other hand, the light extraction film 10 shown in FIG. 1 has a structure of [light scattering layer / base material / gas barrier layer / adhesive layer], so that the overall thickness can be suppressed.

In the step of producing the light extraction film 10 by suppressing the thickness of the entire light extraction film 10, the gas barrier layer 12 is cut when cutting out the individual light extraction films 10 formed on the long base material 11. Damage such as cracks can be further suppressed. Therefore, the deterioration of the gas barrier property due to the light extraction film 10 can be further suppressed.

In the light extraction film 10, if the stacking order of [light scattering layer / base material / gas barrier layer / adhesive layer] is not changed, it is between each layer and outside the light scattering layer 13 (opposite of the base material 11). Other layers may be formed on the side surface). Even in a configuration in which another layer is formed, the total thickness of the light extraction film 10 is preferably within the above range in order to suppress damage to the gas barrier layer 12 during cutting.

Hereinafter, each component of the light extraction film 10 will be described. In the light extraction film 10, transparency means that the total light transmittance is 50% or more. Further, in the light extraction film 10, the total light transmittance is preferably 70% or more. The total light transmittance is based on the method described in JIS K7105: 1981, the total light transmittance and the amount of scattered light are measured using an integrating sphere type light transmittance measuring device, and the diffuse transmittance is subtracted from the total light transmittance. The method of calculating can be used.

[Base material]
The base material 11 is a support for the light extraction film 10, and is not particularly limited as long as it can hold the gas barrier layer 12 and the light scattering layer 13. Specific examples of the base material 11 include polyester resin, methacrylic resin, methacrylic acid-maleic acid copolymer, polystyrene resin, transparent fluororesin, polyimide, fluorinated polyimide resin, polyamide resin, polyamideimide resin, and polyetherimide. Resin, cellulose acylate resin, polyurethane resin, polyether ether ketone resin, polycarbonate resin, alicyclic polyolefin resin, polyarylate resin, polyether sulfone resin, polysulfone resin, cycloolefilun copolymer, fluorene ring-modified polycarbonate resin, alicyclic Examples thereof include a base material containing a thermoplastic resin such as a modified polycarbonate resin, a fluorene ring-modified polyester resin, and an acryloyl compound. The base material 11 can be used alone or in combination of two or more. When the base material 11 has a laminated structure of two or more layers, each base material 11 may be of the same type or of a different type.

The base material 11 is preferably made of a material having heat resistance. Specifically, a material having a linear expansion coefficient of 15 ppm / K or more and 100 ppm / K or less and a glass transition temperature (Tg) of 100 ° C. or more and 300 ° C. or less is preferable. The Tg and the coefficient of linear expansion of the base material 11 can be adjusted with an additive or the like.

When the light extraction film 10 is applied to a light emitting element or the like, the base material 11 may be exposed to a process of 150 ° C. or higher. In this case, if the coefficient of linear expansion of the base material 11 of the light extraction film 10 is 100 ppm / K or less, the substrate dimensions are stable in the above-mentioned steps, and the blocking performance deteriorates due to thermal expansion and contraction. Hateful. Alternatively, it can withstand a thermal process. When the coefficient of linear expansion of the base material 11 is 15 ppm / K or more, the flexibility and flexibility are good, and the problem of breaking like glass is unlikely to occur.

More preferable specific examples of the thermoplastic resin that can be used as the base material 11 include polyethylene terephthalate (PET: 70 ° C.), polyethylene naphthalate (PEN: 120 ° C.), polycarbonate (PC: 140 ° C.), and alicyclic type. Polyolefin (for example, manufactured by Nippon Zeon Co., Ltd., Zeonoa (registered trademark) 1600: 160 ° C.), Polyarylate (PAr: 210 ° C.), Polyethersulfone (PES: 220 ° C.), Polysulfone (PSF: 190 ° C.), Cycloolefin copolymer (COC: Compound described in JP-A-2001-150584: 162 ° C.), Polyethylene (for example, manufactured by Mitsubishi Gas Chemical Co., Ltd., Neoprim (registered trademark): 260 ° C.), Fluorene ring-modified polycarbonate (BCF-PC: JP-A.) The compound described in JP-A-2000-227603: 225 ° C.), the alicyclic-modified polycarbonate (IP-PC: the compound described in JP-A-2000-227603: 205 ° C.), the acryloyl compound (Japanese Patent Laid-Open No. 2002-80616). The compound described: 300 ° C. or higher) and the like (Tg is shown in parentheses). The base material 11 may have a single layer or a laminated structure of two or more layers.

Further, the base material 11 may be an unstretched film or a stretched film. The base material 11 can be produced by a conventionally known general method. As for the method for producing these base materials, the configurations described in paragraphs [0051] to [0055] of International Publication No. 2013/002026 can also be adopted.

The surface of the base material 11 may be subjected to various known treatments for improving adhesion, such as corona discharge treatment, flame treatment, oxidation treatment, plasma treatment, etc., and the above treatments may be performed as necessary. It may be done in combination.

The thickness of the base material 11 (total thickness in the case of a laminated structure of two or more layers) is preferably 10 to 60 μm, and more preferably 20 to 40 μm. When the thickness of the base material 11 is within the above range, the total thickness of the light extraction film 10 can be reduced. In addition, the warp of the light extraction film 10 is easily suppressed.

(Hard coat layer)
The base material 11 may have a layer for imparting a specific function such as a hard coat layer on the surface (one side or both sides). Note that these layers are not included in the thickness of the base material 11 described above.

Examples of the material contained in the hard coat layer include a thermosetting resin and an active energy ray-curable resin, but an active energy ray-curable resin is preferable because molding is easy. Such curable resins can be used alone or in combination of two or more. The active energy ray-curable resin refers to a resin that is cured through a cross-linking reaction or the like by irradiation with active energy rays such as ultraviolet rays or electron beams. As the active energy ray-curable resin, a material containing a monomer having an ethylenically unsaturated double bond is preferably used. This material is cured by irradiating it with active energy rays such as ultraviolet rays and electron beams to form a layer containing a cured product of an active energy ray-curable resin, that is, a hard coat layer. Typical examples of the active energy ray-curable resin include an ultraviolet curable resin and an electron beam curable resin, but an ultraviolet curable resin that is cured by ultraviolet irradiation is preferable. Further, a commercially available base material 11 on which a hard coat layer is formed in advance may be used.

[Gas barrier layer]
The gas barrier layer 12 is not particularly limited as long as it has a gas barrier property, and a conventionally known configuration can be applied. The gas barrier property required for the light extraction film 10 is, for example, water vapor permeability (25 ± 0.5 ° C., relative humidity 90 ± 2% RH) measured by a method according to JIS-K-7129-1992. is there 0.01g / ^(m 2 · 24 hr) or less, JIS-K-7126-1987 oxygen permeability measured in compliance with the method provided in the ^{10 -3 ml / (m 2 ·} 24 hr · atm) or less .. The gas barrier layer 12 may be configured so that the gas barrier property can be realized in the light extraction film 10. The gas barrier layer 12 may be formed of a single layer or may be a laminated body composed of a plurality of layers.

Further, the gas barrier layer 12 constituting the light extraction film 10 may be a gas barrier layer formed by vapor deposition of an inorganic compound or a gabaria layer formed by coating, but a liquid composition containing a silicon-containing compound may be used. , It is preferable that the silicon-containing layer is obtained by coating and drying. In particular, it is preferable to include a polysilazane modified layer as the silicon-containing layer. By including the silicon-containing layer and the polysilazane modified layer as the gas barrier layer 12, the light extraction film 10 can ensure high barrier properties. The polysilazane modified layer is a layer having at least a part of a polysilazane modified portion in which a polysilazane compound is modified by an energy ray such as excimer light. Generally, a modified portion of polysilazane is formed on the surface of the layer irradiated with energy rays.

The gas barrier layer 12 constituting the light extraction film 10 is not particularly limited, and may be a vapor-deposited barrier layer as long as it is a single layer, or can be obtained by applying and drying a liquid composition portion containing a silicon-containing compound. It may be a film having a silicon-containing layer. Further, it may be finally composed of a plurality of layers to be a gas barrier layer. When the gas barrier layer is composed of a plurality of layers, it may have a gas barrier layer formed by vapor deposition, or may have a silicon-containing layer obtained by coating and drying as described above. A mixture of the two, that is, at least one barrier layer in the laminated structure may be a film having a silicon-containing layer obtained by applying and drying a liquid composition containing a silicon-containing compound.

[Vaic phase film formation]
The gas phase film forming method for forming the vapor phase film forming barrier layer is not particularly limited. Existing thin film deposition techniques can be utilized. For example, a vapor phase film forming method such as a conventionally known vapor deposition method, a reactive vapor deposition method, a sputtering method, a reactive sputtering method, or a chemical vapor deposition method can be used. These vapor phase film forming methods can be used by known methods.

The film thickness of the vapor deposition barrier layer is not particularly limited. The vapor deposition method is not particularly limited, and existing thin film deposition techniques can be used. For example, a vapor deposition method, a reactive vapor deposition method, a sputtering method, a reactive sputtering method, a chemical vapor deposition method, or the like can be used.

-Reactive thin-film deposition method The reactive vapor deposition method is a method in which a reactive gas is introduced into a vacuum vessel to react and deposit atoms and molecules evaporated from an evaporation source, and excitation of plasma or the like is performed to promote the reaction. Sources can also be introduced. As a typical raw material, silicon, silicon nitride, silicon oxide, silicon oxynitride and the like are used as the vapor deposition source, and nitrogen, hydrogen, ammonia, oxygen and the like are used as the reactive gas.

-Sputtering method The sputtering method is a method of depositing sputtered target constituent atoms on a substrate by utilizing a sputtering phenomenon in which high-energy ions that have been accelerated by an electric field are incident on the target and the target constituent atoms are knocked out. The reactive sputtering method is a method in which a reactive gas is introduced into a vacuum vessel, the constituent atoms of the sputtered target are reacted with the reactive gas, and the gas is deposited on a substrate. As a typical raw material, silicon, silicon nitride, silicon oxide, silicon oxynitride and the like are used as the target material, and nitrogen, hydrogen, ammonia, oxygen and the like are used as the reactive gas.

-Chemical gas phase deposition method In the chemical gas phase deposition method, a material gas containing a constituent element of a film is introduced into a vacuum vessel, and the material gas is excited by a specific excitation source to form an excited species by a chemical reaction. , A method of depositing on a substrate. As a typical raw material, monosilane, hexamethyldisilazane, ammonia, nitrogen, hydrogen, oxygen and the like are used. The chemical vapor deposition method is a more promising method because it enables high-speed film formation and has better coverage on the substrate than the sputtering method or the like. In particular, a catalytic chemical vapor deposition (Cat-CVD) method using a very high temperature catalyst as an excitation source and a plasma chemical vapor deposition (PECVD) method using a plasma as an excitation source are preferable methods. Hereinafter, these methods will be described in detail.

(Cat-CVD method)
In the Cat-CVD method, a material gas is flowed into a vacuum vessel in which a wire made of tungsten or the like is arranged inside, and the material gas is subjected to a catalytic cracking reaction with a wire energized and heated by a power source, and the generated reaction species is used as a base material. It is a method of depositing. For example, when silicon nitride is deposited, monosilane, ammonia, and hydrogen are used as the material gas. When silicon oxynitride is deposited, oxygen is added in addition to the above material gas. As an example of conditions, a tungsten wire (eg, Φ0.5, length 2.8 m), which is a catalyst, is energized and heated to 1800 ° C., and monosilane, ammonia, and hydrogen (4/200/200 sccm) are circulated as material gases. The pressure is maintained at 10 Pa, and the film is deposited on the substrate whose temperature is adjusted to 100 ° C. Among the reaction species produced by the decomposition reaction on the catalyst body, the main deposited species are SiH ₃ ^* and NH ₂ ^* , and H ^* is a reaction auxiliary species on the membrane surface. In particular, it is thought that the addition of hydrogen can generate a large amount of H ^* and reduce the deposition rate, but promote the reaction for removing H derived from Si—H bonds and NH bonds in the membrane. ..

(PECVD method)
The PECVD method is generated by inflowing a material gas into a vacuum vessel equipped with a plasma source, supplying power from a power source to the plasma source to generate discharge plasma in the vacuum vessel, and decomposing and reacting the material gas with the plasma. This is a method of depositing the reaction species on the substrate 12. Capacitively coupled plasma using parallel plate electrodes, inductively coupled plasma, microwave excitation plasma using surface waves, and the like are used as the plasma source method.

[Coating method: Silicon-containing layer]
The silicon-containing layer obtained by applying and drying a liquid composition containing a silicon-containing compound exhibits gas barrier properties by having a specific composition. Further, unlike the case of being formed by the vapor phase film forming method, the silicon-containing layer can form a gas barrier layer having very few defects because foreign substances such as particles are hardly mixed during the film forming.

The thickness of the silicon-containing layer constituting the gas barrier layer 12 (total thickness in the case of a laminated structure of two or more layers) is preferably 10 to 1000 nm, preferably 50 to 600 nm, from the viewpoint of gas barrier performance. More preferably, it is more preferably 50 to 300 nm. Within this range, the balance between gas barrier property and durability is good.

Examples of the silicon-containing compound for forming the silicon-containing layer include polysiloxane, polysilsesquioxane, polysilazane, polysiloxazan, polysilane, and polycarbosilane. Among these, it is preferable to have at least one selected from the group consisting of a silicon-nitrogen bond, a silicon-hydrogen bond, and a silicon-silicon bond.

More preferably, the silicon-containing compound is polysilazane having a silicon-nitrogen bond and a silicon-hydrogen bond, polysiloxazan having a silicon-nitrogen bond, polysiloxane having a silicon-hydrogen bond, and polysilsesqui having a silicon-hydrogen bond. Oxane, a polysilane having a silicon-silicon bond can be used. It is preferable to use a silicon-containing compound having any of a silicon-nitrogen bond, a silicon-hydrogen bond, and a silicon-silicon bond.

Specific examples of polysiloxane, polysilsesquioxane, and polysiloxazan include the compounds described in paragraphs "093" to "0121" of JP2012-116101A. As the polysiloxane, hydrogenated (hydrogen) polysiloxane is particularly preferable.

The form of polysilane is not particularly limited, and may be a homopolymer such as acyclic polysilane (linear polysilane, branched chain polysilane, network polysilane, etc.), cyclic polysilane, etc., or a random copolymer, It may be a copolymer such as a block copolymer, an alternating copolymer, or a comb-type copolymer.

When the polysilane is an acyclic polysilane, the terminal group (terminal substituent) of the polysilane is a halogen atom (chlorine atom or the like), an alkyl group, a hydroxyl group, an alkoxy group, a silyl group or the like even if it is a hydrogen atom. You may.

Specific examples of polysilanes include polydialkylsilanes such as polydimethylsilane, poly (methylpropylsilane), poly (methylbutylsilane), poly (methylpentylsilane), poly (dibutylsilane), and poly (dihexylsilane), and poly. Polydiarylsilane such as (diphenylsilane), homopolymer such as poly (methylphenylsilane), poly (alkylarylsilane), dialkylsilane such as dimethylsilane-methylhexylsilane copolymer, and co-weight of other dialkylsilane Combined, arylsilane-alkylarylsilane copolymer such as phenylsilane-methylphenylsilane copolymer, dimethylsilane-methylphenylsilane copolymer, dimethylsilane-phenylhexylsilane copolymer, dimethylsilane-methylnaphthylsilane Examples thereof include a polymer, a copolymer of a dialkylsilane-alkylarylsilane copolymer of a methylpropylsilane-methylphenylsilane copolymer, and the like.

Polycarbosilane is a polymer compound having a (-Si-C-) bond in the main chain in the molecule. As the polycarbosilane, those containing a repeating unit represented by the following formula (a) are preferable.

In the formula, Rw and Rv independently represent a hydrogen atom, a hydroxyl group, an alkyl group, an aryl group, an alkenyl group, or a monovalent heterocyclic group. The plurality of Rw and Rv may be the same or different. R represents an alkylene group, an arylene group or a divalent heterocyclic group.
The weight average molecular weight of the polycarbosilane having the repeating unit represented by the formula (a) is usually 400 to 12000.

The heterocycle of the monovalent heterocyclic group of Rw and Rv is particularly limited as long as it is a 3- to 10-membered cyclic compound containing at least one heteroatom such as an oxygen atom, a nitrogen atom, and a sulfur atom in addition to the carbon atom. There is no. Specific examples of the monovalent heterocyclic group include 2-pyridyl group, 3-pyridyl group, 4-pyridyl group, 2-thienyl group, 3-thienyl group, 2-furyl group, 3-furyl group and 3-pyrazolyl. Group, 4-pyrazolyl group, 2-imidazolyl group, 4-imidazolyl group, 1,2,4-triazine-3-yl group, 1,2,4-triazine-5-yl group, 2-pyrimidyl group, 4- Pyrimidyl group, 5-pyrimidyl group, 3-pyridadyl group, 4-pyridadyl group, 2-pyrazyl group, 2- (13,5-triazine) group, 3- (1,2,4-triazine) group, 6- ( 1,2,4-triazil) group, 2-thiazolyl group, 5-thiazolyl group, 3-isothiazolyl group, 5-isothiazolyl group, 2- (13,4-thiadiazolyl) group, 3- (1,2,4- Thiasiazolyl) group, 2-oxazolyl group, 4-oxazolyl group, 3-isooxazolyl group, 5-isooxazolyl group, 2- (13,4-oxadiazolyl) group, 3- (1,2,4-oxadiazolyl) group, 5- Examples thereof include a (1,2,3-oxadiazolyl) group. These groups may have substituents such as an alkyl group, an aryl group, an alkoxy group and an aryloxy group at arbitrary positions.

Examples of the alkylene group of R include an alkylene group having 1 to 10 carbon atoms such as a methylene group, an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group and an octamethylene group. Examples of the arylene group include an arylene group having 6 to 20 carbon atoms such as a p-phenylene group, a 1,4-naphthylene group and a 2,5-naphthylene group. The alkylene group and arylene group of R may have a substituent such as an alkyl group, an aryl group, an alkoxy group or a halogen atom at an arbitrary position.

The divalent heterocyclic group of R may be a divalent group derived from a 3- to 10-membered heterocyclic compound containing at least one heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom in addition to a carbon atom. There are no particular restrictions. Specific examples of the divalent heterocyclic group include a thiophendiyl group such as a 2,5-thiophendiyl group, a frangyl group such as a 2,5-frangyl group, and a selenophene such as a 2,5-selenofendiyl group. Pyrrole diyl group such as diyl group, 2,5-pyrrole diyl group, pyridine diyl group such as 2,5-pyridinediyl group, 2,6-pyridinediyl group, 2,5-thieno [3,2-b] thiophendiyl group , 2,5-Thieno [2,3-b] Thienothiophenidyl group such as thiophendiyl group, quinolinediyl group such as 2,6-quinolindiyl group, 1,4-isoquinolindiyl group, 1,5-isoquinolindiyl group, etc. Isoquinolindiyl groups, quinoxalindiyl groups such as 5,8-quinoxalindiyl groups, benzo [1,2,5] thiaxazolediyl groups such as 4,7-benzo [1,2,5] thiazazolediyl groups, 4,7 -Benzothiazolediyl group such as benzothiazolediyl group, 2,7-carbazolediyl group, carbazolediyl group such as 3,6-carbazolediyl group, phenoxazinediyl group such as 3,7-phenoxazinediyl group, 3, A phenothiazinediyl group such as a 7-phenothiazinediyl group, a dibenzosiloldiyl group such as a 2,7-dibenzosiloldiyl group, a 2,6-benzo [1,2-b: 4,5-b'] dithiophendiyl group, 2,6-benzo [1,2-b: 5,4-b'] dithiophendiyl group, 2,6-benzo [2,1-b: 3,4-b'] dithiophendiyl group, 2, Examples thereof include a benzodithiophenidyl group such as a 6-benzo [1,2-b: 3,4-b'] dithiophendiyl group. The divalent heterocyclic group of R may have a substituent such as an alkyl group, an aryl group, an alkoxy group, or a halogen atom at an arbitrary position.

Among these, in the formula (a), polycarbosilane containing a repeating unit in which Rw and Rv are independently hydrogen atoms, alkyl groups or aryl groups and R is an alkylene group or an arylene group is more preferable. Further, a polycarbosilane containing a repeating unit in which Rw and Rv are independently hydrogen atoms or alkyl groups and R is an alkylene group is preferable.

Polysilazane is more preferable as a material for forming the silicon-containing layer.
Polysilazane is a polymer having a silicon-nitrogen bond, and is a ceramic such as SiO ₂ , Si ₃ N ₄ , and both intermediate solid solutions SiO _x N _y having a bond of Si—N, Si—H, N—H, etc. It is a precursor inorganic polymer. Specifically, polysilazane preferably has a structure represented by the following general formula (I).

In the above general formula (I), R ₁ , R ₂ and R ₃ are independently hydrogen atoms, substituted or unsubstituted alkyl groups, aryl groups, vinyl groups or (trialkoxysilyl) alkyl groups. .. At this time, R ₁ , R ₂ and R ₃ may be the same or different, respectively. Further, in the general formula (I), n is an integer, and it is preferable that polysilazane having a structure represented by the general formula (I) is defined to have a number average molecular weight of 150 to 150,000 g / mol.
In the compound having the structure represented by the general formula (I), one of the preferable embodiments is perhydropolysilazane in which all of R ₁ , R ₂ and R ₃ are hydrogen atoms.

Further, as the polysilazane, those having a structure represented by the following general formula (II) are preferable.

In the general formula _{(II), R 1 ',} R 2', R 3 ', R 4', R 5 ' and R _6' are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, It is an aryl group, a vinyl group, or a (trialkoxysilyl) alkyl group. In this _{case, R 1 ', R 2'} , R 3 ', R 4', R 5 ' and R _6' are each, may be the same or different. Further, in the above general formula (II), n'and p are integers, and polysilazane having a structure represented by the general formula (II) is defined to have a number average molecular weight of 150 to 150,000 g / mol. Is preferable. Note that n'and p may be the same or different.

Among the polysilazane of the formula _{(II), R 1 ',} R 3' and R _{6 'represents} each a hydrogen atom, R _2', compounds R _{4 'and} R _5' are each a methyl group, _{R 1 ',} R _3' and R _{6 'are} each a hydrogen atom, R _2', R _{4 'are} each a methyl group, R _5' compound represents a vinyl group, _{or, R 1 ', R 3'} , R 4 _'and R _6' are each a hydrogen atom, a compound R 2 _'and R _5' represent each a methyl group is preferred.

Further, as the polysilazane, those having a structure represented by the following general formula (III) are preferable.

In the above general formula (III), R _{1 "} , R _2" , R _{3 "} , R _4" , R _{5 "} , R _6" , R _{7 "} , R _8" and R _{9 "} are independent of each other. A hydrogen atom, substituted or unsubstituted alkyl group, aryl group, vinyl group or (trialkoxysilyl) alkyl group. In this case, R _{1 "} , R _2" , R _{3 "} , R _4" , R _{5 "} , R _{6 "} , R _7" , R _{8 "} and R _9" may be the same or different, respectively.

Further, in the above general formula (III), n ", p" and q are integers so that polysilazane having a structure represented by the general formula (III) has a number average molecular weight of 150 to 150,000 g / mol. It is preferable to be determined. Note that n ", p ^" and q may be the same or different.

Of the polysilazanes of the above general formula (III), R _{1 "} , R _3" and R _{6 "} represent hydrogen atoms, respectively, and R _2" , R _{4 "} , R _5" and R _{8 "} represent a methyl group, respectively. , R _{9 "} represents a (triethoxysilyl) propyl group, and R _7" represents an alkyl group or a hydrogen atom.

On the other hand, organopolysilazane in which a part of the hydrogen atom portion bonded to Si is substituted with an alkyl group or the like has an alkyl group such as a methyl group, so that the adhesiveness with the base material as a base is improved and is hard. The brittle polysilazane ceramic film can be made tough. Therefore, there is an advantage that the occurrence of cracks can be suppressed even when the thickness (average) of the silicon-containing layer is increased. Therefore, these perhydropolysilazane and organopolysilazane may be appropriately selected depending on the intended use, and may be mixed and used.

Perhydropolysilazane is presumed to have a linear structure and a ring structure centered on 6- and 8-membered rings. The molecular weight is about 600 to 2000 (in terms of polystyrene) in terms of number average molecular weight (Mn), and there are liquid or solid substances, and the state varies depending on the molecular weight.

Polysilazane is commercially available in a solution state dissolved in an organic solvent, and the commercially available product can be used as it is as a silicon-containing liquid composition for forming a silicon-containing layer. Commercially available products of polysilazane solution include NN120, NN120-20, NAX120-20, NN110, NN310, NN320, NL110A, NL120A, NL120-20, NL150A, NP110, NP140, SP140, etc. manufactured by AZ Electronic Materials Co., Ltd. Be done. These polysilazane solutions can also be used alone or in combination of two or more.

Another example of polysilazane used for forming a silicon-containing layer is the following polysilazane. For example, a silicon alkoxide-added polysilazane obtained by reacting the above polysilazane with a silicon alkoxide (Japanese Patent Laid-Open No. 5-238827), a glycidol-added polysilazane obtained by reacting glycidol (Japanese Patent Laid-Open No. 6-122852), and an alcohol are reacted. Alcohol-added polysilazane (Japanese Patent Laid-Open No. 6-240208), metal carboxylate-added polysilazane (Japanese Patent Laid-Open No. 6-299118) obtained by reacting a metal carboxylate, and an acetylacetonate complex containing a metal. Acetylacetonate complex-added polysilazane (Japanese Patent Laid-Open No. 6-306329) obtained by reacting with, and metal fine particle-added polysilazane (Japanese Patent Laid-Open No. 7-196986) obtained by adding metal fine particles, etc. Polysilazane to be mentioned.

When polysilazane is used for forming the silicon-containing layer, the content of polysilazane in the silicon-containing layer before irradiation with vacuum ultraviolet rays can be 100% by mass when the total mass of the silicon-containing layer is 100% by mass. When the silicon-containing layer before irradiation with vacuum ultraviolet rays contains a layer other than polysilazane, the content of polysilazane in the layer is preferably 10% by mass or more and 99% by mass or less, and 40% by mass or more and 95% by mass or more. It is more preferably 70% by mass or more, and particularly preferably 70% by mass or more and 95% by mass or less.

(Silicon-containing liquid composition)
The solvent for preparing the liquid composition (silicon-containing liquid composition) for forming the silicon-containing layer is not particularly limited as long as it can dissolve the silicon-containing compound. As the solvent, an organic solvent that does not contain water and a reactive group (for example, a hydroxyl group or an amine group) that easily reacts with the silicon-containing compound and is inert to the silicon-containing compound is preferable and is not. Protic organic solvents are more preferred. Specifically, as the solvent, an aproton solvent, for example, an aliphatic hydrocarbon such as pentane, hexane, cyclohexane, toluene, xylene, sorbesso, turpen, an alicyclic hydrocarbon, a hydrocarbon such as an aromatic hydrocarbon, etc. Solvents, halogen hydrocarbon solvents such as methylene chloride and trichloroethane, esters such as ethyl acetate and butyl acetate, ketones such as acetone and methyl ethyl ketone, aliphatic ethers such as dibutyl ether, dioxane and tetrahydrofuran, ethers such as alicyclic ethers. Such as, for example, tetrahydrofuran, dibutyl ether, mono- and polyalkylene glycol dialkyl ether (diglimes) and the like can be mentioned. The solvent is selected according to the purpose such as the solubility of polysilazane and the evaporation rate of the solvent, and may be used alone or in the form of a mixture of two or more kinds.

The concentration of the silicon-containing compound in the silicon-containing liquid composition is not particularly limited. The concentration of the silicon-containing compound in the silicon-containing liquid composition varies depending on the layer thickness and the pot life of the liquid composition, but is preferably 1 to 80% by mass, more preferably 5 to 50% by mass, and further preferably 10 to 10% by mass. It is 40% by mass.

When modifying the silicon-containing layer, it is preferable that the silicon-containing liquid composition contains a catalyst for promoting the modification. As the catalyst for accelerating the modification, a basic catalyst is preferable, and in particular, N, N-diethylethanolamine, N, N-dimethylethanolamine, triethanolamine, triethylamine, 3-morpholinopropylamine, N, N , N', N'-tetramethyl-13-diaminopropane, N, N, N', N'-tetramethyl-1,6-diaminohexane and other amine compounds, Pt compounds such as Pt acetylacetonate, propionic acid Examples thereof include Pd compounds such as Pd, metal catalysts such as Rh compounds such as Rh acetylacetonate, and N-heterocyclic compounds. Of these, it is preferable to use an amine catalyst. The concentration of the catalyst added at this time is preferably in the range of 0.1 to 10% by mass, more preferably 0.5 to 7% by mass, based on the silicon compound. By setting the amount of the catalyst added within this range, it is possible to avoid excessive silanol formation due to rapid progress of the reaction, decrease in film density, increase in film defects, and the like.

The following additives can be used in the silicon-containing liquid composition, if necessary. For example, cellulose esters such as cellulose ethers, ethyl cellulose, nitrocellulose, cellulose acetate, cellulose acetobutyrate, natural resins such as rubber and rosin resin, synthetic resins such as polymerized resins, aminoplasts, especially urea resins and melamine formaldehyde resins. , Alkido resin, acrylic resin, polyester resin or modified polyester resin, epoxy resin, polyisocyanate or condensed resin such as blocked polyisocyanate and polysiloxane.

(Applying method)
As a method for applying the silicon-containing liquid composition, a conventionally known appropriate wet coating method is adopted. Specific examples include a spin coating method, a roll coating method, a flow coating method, an inkjet method, a spray coating method, a printing method, a dip coating method, a cast film forming method, a bar coating method, a die coating method, and a gravure printing method. Be done.
The coating thickness is appropriately set according to a preferable thickness and purpose.

After applying the liquid composition, the coating film is dried. The organic solvent contained in the coating film is removed by drying the coating film. At this time, all of the organic solvent contained in the coating film may be dried, or a part of the organic solvent may remain. A suitable silicon-containing layer can be obtained even when a part of the organic solvent remains. The remaining solvent will be removed later.

The drying temperature of the coating film varies depending on the substrate to which it is applied, but is preferably 50 to 200 ° C. For example, when a polyethylene terephthalate film having a glass transition temperature (Tg) of 70 ° C. is used as the base material 11, the drying temperature is preferably set to 150 ° C. or lower in consideration of deformation of the base material 11 due to heat and the like. .. The temperature is set by using a hot plate, oven, furnace or the like. The drying time is preferably set to a short time, for example, when the drying temperature is 150 ° C., it is preferably set to 30 minutes or less. Further, the dry atmosphere may be any of the conditions such as an air atmosphere, a nitrogen atmosphere, an argon atmosphere, a vacuum atmosphere, and a reduced pressure atmosphere in which the oxygen concentration is controlled.

The coating film obtained by applying the silicon-containing liquid composition may be subjected to a treatment for removing water before or during irradiation with vacuum ultraviolet rays. As a method for removing water, a form in which the coating film is held and dehumidified in a low humidity environment is preferable. Since the humidity in a low humidity environment changes depending on the temperature, the relationship between the temperature and the humidity is shown in a preferable form by the regulation of the dew point temperature. A preferable dew point temperature is 4 ° C. or lower (temperature 25 ° C./humidity 25%), and a more preferable dew point temperature is −5 ° C. or lower (temperature 25 ° C./humidity 10%). It is preferable to appropriately set the time for holding and maintaining the coating film. Specifically, it is preferable that the dew point temperature is −5 ° C. or lower and the maintenance time is 1 minute or longer. The lower limit of the dew point temperature is not particularly limited, but is usually −50 ° C. or higher, preferably −40 ° C. or higher. By removing water before or during the reforming treatment, the dehydration reaction of the silicon-containing layer converted to silanol is promoted.

(Vacuum UV irradiation)
The coating film containing the silicon-containing compound formed as described above can be applied to the gas barrier layer as a silicon-containing layer as it is, but it is preferable to carry out a conversion reaction (modification) of the silicon-containing layer. .. As the treatment for the conversion reaction, ultraviolet irradiation, plasma irradiation, heat treatment and the like can be performed, and among them, it is preferable to perform the conversion reaction (modification) of the silicon-containing layer by irradiating with vacuum ultraviolet rays. In particular, it is preferable to irradiate the silicon-containing layer containing polysilazane with vacuum ultraviolet rays to form a polysilazane modified layer.

The vacuum ultraviolet irradiation can be applied to both batch processing and continuous processing, and can be appropriately selected depending on the shape of the base material 11 to be used. For example, in the case of batch processing, the processing can be performed in an ultraviolet firing furnace equipped with an ultraviolet generation source. The ultraviolet firing furnace itself is generally known, and for example, an ultraviolet firing furnace manufactured by Igraphics Co., Ltd. can be used. Further, when the object is in the form of a long film, it is possible to continuously irradiate ultraviolet rays in a dry zone provided with an ultraviolet source while transporting the object. The time required for ultraviolet irradiation depends on the composition and concentration of the base material used and the silicon-containing compound, but is generally 0.1 seconds to 10 minutes, preferably 0.5 seconds to 3 minutes.

Modification by vacuum ultraviolet irradiation uses light energy of 100 to 200 nm, which is larger than the interatomic bonding force in a silicon-containing compound (particularly a polysilazane compound). Preferably, light energy having a wavelength of 100 to 180 nm is used. By this vacuum ultraviolet irradiation, the oxidation reaction by active oxygen and ozone is promoted while directly cutting the atomic bonds by the action of only photons called the photon process. As a result, a film containing silicon nitride can be formed at a relatively low temperature (about 200 ° C. or lower). When performing the following excimer irradiation treatment, it is preferable to use heat treatment in combination with the excimer irradiation treatment.

The vacuum ultraviolet source may be any one that generates light having a wavelength of 100 to 180 nm. Preferably, an excimer radiator with maximum emission at about 172 nm (eg, an Xe excimer lamp), a low pressure mercury vapor lamp with a emission line at about 185 nm, medium and high pressure mercury steam lamps with wavelength components below 230 nm, and about. An excimer lamp having a maximum emission at 222 nm.

Of these, the Xe excimer lamp has excellent luminous efficiency because it emits ultraviolet rays having a short wavelength of 172 nm at a single wavelength. Since this light has a large oxygen absorption coefficient, it is possible to generate radical oxygen atom species and ozone at a high concentration with a small amount of oxygen. Further, it is known that the energy of light having a short wavelength of 172 nm has a high ability to dissociate the bonds of organic substances. With the high energy of active oxygen, ozone and ultraviolet radiation, it is possible to modify the coating film in a short time.

Since the excimer lamp has a high light generation efficiency, it can be turned on with a low power input. Further, since light having a long wavelength that causes the temperature rise due to light is not emitted and energy is irradiated at a short wavelength in the ultraviolet region, the rise in the surface temperature of the object to be irradiated is suppressed. Therefore, it is suitable for flexible film materials such as PET, which are said to be easily affected by heat.

Oxygen is required for the reaction by vacuum ultraviolet irradiation, but since vacuum ultraviolet is absorbed by oxygen, the efficiency of the ultraviolet irradiation process tends to decrease due to oxygen. Therefore, it is preferable to irradiate the vacuum ultraviolet rays in a state where the oxygen concentration and the water vapor concentration are as low as possible. That is, the oxygen concentration during vacuum ultraviolet irradiation is preferably 10 to 20000 volume ppm (0.001 to 2% by volume), and preferably 50 to 10000 volume ppm (0.005 to 1 volume%). More preferred. The water vapor concentration during vacuum ultraviolet irradiation is preferably in the range of 1000 to 4000 volume ppm.

The gas satisfying the irradiation atmosphere used for vacuum ultraviolet irradiation is preferably a dry inert gas, and particularly preferably a dry nitrogen gas from the viewpoint of cost. The oxygen concentration can be adjusted by measuring the flow rates of the oxygen gas and the inert gas introduced into the irradiation chamber and changing the flow rate ratio.

In vacuum ultraviolet irradiation step, preferably the intensity of the vacuum ultraviolet rays in the coated surface of the coating film is subjected is a ^{1mW / cm 2 ~10W / cm 2} , more preferably 30mW / cm ² ~200mW / cm 2 and further preferably ^{50mW / cm 2 ~160mW / cm 2} . If it is 1 mW / cm ² or more, the reforming efficiency is improved. When it is 10 W / cm ² or less, ablation that may occur in the coating film and damage to the base material 11 can be reduced.

Irradiation energy amount of the vacuum ultraviolet rays to the surface of the coating film (dose) is preferably 1~10J / cm ^2, more preferably 3~7J / cm ^2. Within this range, it is possible to suppress the generation of cracks due to excessive modification and the thermal deformation of the base material 11, and the productivity is improved.

The vacuum ultraviolet light used to irradiate the surface of the coating film may be generated from a plasma formed by a gas containing at least one of CO, CO ₂ and CH ₄ . Further, as the gas containing at least one of CO, CO ₂ and CH ₄ (hereinafter, also referred to as carbon-containing gas), the carbon-containing gas may be used alone, but carbon may be used with the rare gas or H ₂ as the main gas. It is preferable to add a small amount of the contained gas. Capacitively coupled plasma and the like can be mentioned as a plasma generation method.

When the silicon-containing layer is not irradiated with vacuum ultraviolet rays, the silicon-containing layer is a coating film obtained by applying and drying a liquid composition containing a silicon-containing compound at 5 to 40 ° C. It is formed by storing for 1 to 1000 hours under the condition of relative humidity of 0 to 60% RH.

[Light scattering layer]
The light scattering layer 13 is a layer that scatters the light transmitted through the light extraction film 10, and when the light extraction film 10 is applied to a light emitting element or the like, the efficiency of extracting the light emitted from the light emitting element to the outside (light). This is a layer for improving the extraction efficiency). The light scattering layer 13 is preferably composed of a resin material and a light scattering material.

The thickness of the light scattering layer 13 is preferably 5 μm or more and 30 μm or less. When the thickness of the light scattering layer 13 is 1/3 times or more and 1 times or less the thickness of the pressure-sensitive adhesive layer 14, the overall thickness of the light extraction film 10 can be suppressed, and the warp can be further suppressed. .. Further, in order to suppress the angle-dependent color shift, the thickness of the light scattering layer 13 is preferably large, and in order to improve the front luminance, the thickness of the light scattering layer 13 is preferably small. Therefore, the thickness of the light scattering layer 13 is more preferably 6 μm or more and 20 μm or less.

Examples of the light scattering layer 13 include a configuration in which a diffraction grating is introduced (Japanese Patent Laid-Open No. 11-283751), a configuration in which a light scattering layer having a resin material and a light scattering material is provided (Japanese Patent Laid-Open No. 2004-319331), and the like. Be done. From the viewpoint of light extraction efficiency, it is preferable that the light scattering layer 13 is composed of a resin material (binder) and a light scattering material dispersed in the resin material.

(Resin material)
As the resin material, a thermoplastic resin, a thermosetting resin, an ultraviolet curable resin, or an electron beam curable resin can be used. Since the light scattering layer 13 is required to have hardness, smoothness, etc., it is preferable to use an ultraviolet curable resin or an electron beam curable resin as the resin material, and it is particularly preferable to use an ultraviolet curable resin.

The ultraviolet curable resin can be used without particular limitation as long as it forms a transparent resin composition by curing, and examples thereof include silicone resin, epoxy resin, vinyl ester resin, acrylic resin, and allyl ester resin. .. Particularly preferably, an acrylic resin can be used from the viewpoint of hardness, smoothness, and transparency.

Examples of the acrylic resin composition include an acrylate compound having a radically reactive unsaturated compound, a mercapto compound having an acrylate compound and a thiol group, an epoxy acrylate, a urethane acrylate, a polyester acrylate, a polyether acrylate, a polyethylene glycol acrylate, and a glycerol methacrylate. Examples thereof include compositions in which a polyfunctional acrylate monomer such as the above is dissolved. Further, any mixture containing the above resin can be used, and it is particularly limited as long as it is a photosensitive resin containing a reactive monomer having one or more photopolymerizable unsaturated bonds in the molecule. There is no.

From the viewpoint of hardness, smoothness, and transparency, the acrylic resin is a reactive silica particle in which a photosensitive group having photopolymerization reactivity is introduced into the surface as described in International Publication No. 2008/035669. (Hereinafter, also simply referred to as "reactive silica particles") is preferably contained. Here, examples of the photopolymerizable photosensitive group include a polymerizable unsaturated group represented by a (meth) acryloyloxy group. Further, the photosensitive resin preferably contains a photosensitive group introduced into the surface of the reactive silica particles and a compound capable of photopolymerization reaction. Examples of the compound capable of photopolymerization reaction include unsaturated organic compounds having a polymerizable unsaturated group. Here, the average particle size of the reactive silica particles is preferably 0.001 to 0.1 μm. By setting the average particle size in such a range, transparency, smoothness, and hardness can be satisfied in a well-balanced manner.

A fluorine-containing vinyl monomer can also be used as the acrylic resin in that the refractive index can be adjusted. Fluorin-containing vinyl monomers include fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, etc.), (meth) acrylic acid moieties, and fully fluorinated alkyl ester derivatives (for example, Biscort 6FM (trade name)). , Osaka Organic Chemicals), R-2020 (trade name, manufactured by Daikin), etc.), fully or partially fluorinated vinyl ethers, and the like.

(Light scattering material)
As the light scattering material, either inorganic particles or organic particles can be used. The particles are selected according to the refractive index required for the light scattering layer 13. For example, when the refractive index of the light scattering layer 13 is increased, it is preferable to use inorganic particles, and when the refractive index is decreased, it is preferable to use fluorine-containing organic particles.

The inorganic particles are preferably oxides of at least one metal selected from, for example, silicon, zirconium, titanium, aluminum, indium, zinc, tin and antimony, and specific examples thereof are SiO ₂ , ZrO _2. , TiO ₂ , Al ₂ O ₃ (alumina), In ₂ O ₃ , ZnO, SnO ₂ , Sb ₂ O ₃ , ITO, MgF _{2, and the} like. In addition, synthetic mica (mica), kaolin (Al ₂ Si ₂ O ₅ (OH) ₄ ) and the like can also be used. Among the above, silicon oxide, zinc oxide, titanium oxide, zirconium oxide, and alumina are preferable from the viewpoint of reflectance and the like. These inorganic particles can also be modified with other compositions for the purpose of improving the reflectance of light on the surface.

From the viewpoint of light scattering, the particles preferably have a particle size of 0.1 to 5.0 μm, preferably 0.2 to 2.0 μm. If the particle size is smaller than 0.1 μm, the light scattering property becomes small, which is not preferable. If the particle size is larger than 5.0 μm, the light transmittance deteriorates depending on the thickness and content, which is not preferable.

As the particles, anisotropic particles, that is, needle-shaped or plate-shaped particles can also be used. Moreover, one kind or two or more kinds of particles can be appropriately selected and used. Further, as the particles, other inorganic particles and organic particles can be mixed and used. The content in the light scattering layer 13 is not particularly limited, but is preferably in the range of 0.1 to 50% by mass, preferably 1 to 20% by mass from the viewpoint of transparency and smoothness.

[Adhesive layer]
The pressure-sensitive adhesive layer 14 is provided for attaching the light extraction film 10 to other devices or members such as a light emitting element. As the pressure-sensitive adhesive layer 14, a conventionally known material can be used without particular limitation as long as the pressure-sensitive adhesive strength required for bonding can be obtained in the light extraction film 10.

The thickness of the pressure-sensitive adhesive layer 14 is preferably 10 μm or more and 30 μm or less. When the thickness of the pressure-sensitive adhesive layer 14 is within this range and is 1 to 3 times the thickness of the light scattering layer 13, the overall thickness of the light extraction film 10 is suppressed, and further, warpage is caused. It can be suppressed.

(Adhesive)
As the pressure-sensitive adhesive used for the pressure-sensitive adhesive layer 14, it is preferable to use a pressure-sensitive pressure-sensitive adhesive. The pressure-sensitive adhesive has cohesive force and elasticity, and can maintain stable adhesiveness for a long period of time. Further, when forming the pressure-sensitive adhesive layer, the light extraction film 10 can be attached to another member simply by applying pressure without requiring requirements such as heat and an organic solvent.

As the material for forming the pressure-sensitive adhesive layer 14, a material having excellent transparency is preferable. Examples of the pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer 14 include a pressure-sensitive adhesive containing an epoxy resin, an acrylic resin, a rubber resin, a urethane resin, a vinyl ether resin, a silicon resin, and the like. it can. In particular, from the viewpoint of adhesiveness and workability, it is preferable to use an adhesive containing at least one of an epoxy resin and an acrylic resin. As the form of the pressure-sensitive adhesive, for example, a solvent type, an emulsion type, a hot melt type and the like can be used.

Further, in addition to the above resins contained in the pressure-sensitive adhesive, various additives can be used from the viewpoint of improving the physical properties of the pressure-sensitive adhesive layer 14. For example, natural resins such as rosin, modified rosins, rosins and derivatives of modified rosins, polyterpene resins, terpene modified products, aliphatic hydrocarbon resins, cyclopentadiene resins, aromatic petroleum resins, phenolic resins, alkyl- If necessary, a tackifier such as a phenol-acetylene resin, a kumaron-indene resin, a vinyltoluene-α-methylstyrene copolymer, an antiaging agent, a stabilizer, and a softening agent can be used. .. Two or more of these can be used if necessary. Further, in order to increase the light resistance, an organic ultraviolet absorber such as a benzophenone type or a benzotriazole type can be added to the pressure-sensitive adhesive.

The pressure-sensitive adhesive layer 14 can be formed by applying the composition containing the pressure-sensitive adhesive on the gas barrier layer 12 and then drying the coating film. As a coating device for the composition containing the adhesive, a reverse roll coater, a knife coater, a bar coater, a slot die coater, an air knife coater, a reverse gravure coater, a vario gravure coater and the like can be used.

Further, the pressure-sensitive adhesive layer 14 may be formed by preparing a pressure-sensitive adhesive film having a pressure-sensitive adhesive layer formed on the separator film in advance and transferring the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film onto the gas barrier layer 12. .. At this time, the pressure applied when the pressure-sensitive adhesive film is bonded onto the gas barrier layer 12 is not particularly limited as long as the desired adhesive strength can be obtained, but it is preferably performed within a surface pressure of 5 to 600 kPa. More preferably, the pressure is 10 to 500 kPa. Further, when laminating, if necessary, the base material 11 may be heated to Tg or less.

[Manufacturing method of light extraction film]
Next, the method for manufacturing the above-mentioned light extraction film 10 will be described.
First, the base material 11 is prepared. Then, the gas barrier layer 12 is formed on the first main surface of the base material 11. It is preferable that the gas barrier layer 12 is formed with a silicon-containing layer by the method described above, and a polysilazane modified layer is formed by excimer irradiation treatment. Further, a commercially available gas barrier film in which the gas barrier layer 12 is formed on the base material 11 can also be used.

Next, the light scattering layer 13 is formed on the second main surface of the base material 11. To form the light scattering layer 13, a method of preparing a liquid composition in which a light scattering material is dispersed in a resin, applying the composition, and then curing the light scattering layer 13 can be applied.

Next, a composition containing an adhesive is prepared, the composition is applied onto a release film, and then dried. Then, a layer of the composition containing the formed adhesive is bonded onto the gas barrier layer 12 together with the release film. As a result, the pressure-sensitive adhesive layer 14 can be formed on the gas barrier layer 12 to produce the light extraction film 10. The release film used for forming the pressure-sensitive adhesive layer 14 may or may not be peeled off, if necessary, after the light extraction film 10 is produced.

<2. Embodiment of organic electroluminescence light emitting device>
Next, an organic electroluminescence light emitting device (organic EL light emitting device) will be described. The organic EL light emitting device of the present embodiment includes the above-mentioned light extraction film on the light extraction surface side of the organic electroluminescence element (organic EL element). Specifically, in an organic EL element having a first electrode, a light emitting unit, and a second electrode, a light extraction film is bonded onto a base material or a sealing member which is an exterior body of the organic EL element, and the organic EL emits light. The device is configured.

FIG. 2 shows a schematic configuration of an organic EL light emitting device. The organic EL light emitting device 20 shown in FIG. 2 includes an organic EL element 25 and a light extraction film 10. The light extraction film 10 has the same structure as that of FIG. 1 described above, and includes a gas barrier layer 12, a light scattering layer 13, and an adhesive layer 14 on a base material 11 (hereinafter, the first base material 11). The organic EL element 25 includes a second base material 21, a first electrode 22 provided on one surface of the second base material 21, and a second electrode 24, and includes an organic light emitting material between the electrodes. A light emitting unit 23 having one or more light emitting layers is provided. The light extraction film 10 is bonded to the other surface of the second base material 21 by the pressure-sensitive adhesive layer 14.

Hereinafter, each component of the organic EL light emitting device 20 will be described. In the organic EL light emitting device 20, the light extraction film 10 has the same configuration as that of FIG. 1 described above. Therefore, in the following description of the organic EL light emitting device 20, a duplicate description relating to the light extraction film 10 will be omitted.

[Second base material]
The same configuration as that of the first base material 11 described above can be applied to the second base material 21. For example, a conventionally known resin film base material can be used without particular limitation. The thickness of the second base material 21 is preferably 10 to 500 μm, more preferably 20 to 250 μm, and even more preferably 30 to 150 μm. When the thickness of the second base material 21 is in the range of 10 to 500 μm, the organic EL element 25 can be stably manufactured.

Further, the second base material 21 may have a gas barrier layer on the side of the first electrode 22. By having the gas barrier layer, the reliability of the organic EL element 25 is improved. As the gas barrier layer formed on the second base material 21, the same configuration as the gas barrier layer 12 in the above-mentioned light extraction film 10 can be applied.
Further, the second base material 21 may be provided with a layer for imparting other functions, if necessary.

[1st electrode / 2nd electrode]
The first electrode 22 and the second electrode 24 are layers containing a conductive material for conducting electricity in the organic EL light emitting device 20. The first electrode 22 and the second electrode 24 are provided with a light emitting unit 23 sandwiched between them. When the first electrode 22 is an anode, the second electrode 24 is used as a cathode, and the first electrode 22 is used. Is a cathode, the second electrode 24 is used as the anode.

When the organic EL element 25 is a bottom emission type that extracts light from the second base material 21 side, the first electrode 22 is formed of a transparent conductive film, and the second electrode 24 is made of a conductive film having high reflectance. Form. When the organic EL element 25 is a double-sided light emitting type, both the first electrode 22 and the second electrode 24 are formed of a transparent conductive film.

In the first electrode 22 and the second electrode 24, examples of the transparent conductive film include metal thin films such as Au, Ag, Pt, Cu, Rh, Pd, Al, and Cr, and In ₂ O ₃ , CdO, and CdIn ₂ O. ₄ , Cd ₂ SnO ₄ , TIO ₂ , SnO ₂ , ZnO, ITO (indium / tin oxide), IZO (indium / zinc oxide), IGO, IWZO, GZO, IGZO, ZTO, ZnO, TiO _x , VO _{x , CuAlO 2, CuGaO 2, SrCu} 2 O 2, metal oxides RuO like, TiN, ZrN, HfN, CuI , InN, GaN, and inorganic compounds such as _{LaB 62.} Further, a material such as IDIXO (In ₂ O _3- ZnO) may be used. As the transparent conductive film, only one kind of these conductive materials may be contained, or two or more kinds thereof may be contained.

In the organic EL light emitting device 20, one or more kinds of metal oxides selected from the above-mentioned IZO, IGO, IWZO, GZO, IGZO, ZnO, and ZTO as the transparent conductive film from the viewpoint of transparency and conductivity. Is preferably included. When a metal oxide or an inorganic compound is used as the transparent conductive film, the thickness is preferably 10 nm or more and 500 nm or less, and more preferably 100 nm or more and 300 nm or less, although it depends on the volume resistance of the material used. If the thickness is less than 10 nm, the metal oxide or the inorganic compound does not form a continuous film, and the desired conductivity cannot be obtained. If the thickness exceeds 500 nm, cracks due to bending may occur.

When the above-mentioned metal thin film is used as the transparent conductive film, it is preferable to use a metal thin film containing silver as a main component from the viewpoint of conductivity. As a metal containing silver as a main component, it means that the silver content ratio is 60 at% (atomic%) or more. From the viewpoint of conductivity, the silver content ratio is preferably 90 at% or more, more preferably 95 at% or more, and further preferably composed of silver alone. Examples of the silver-based alloy include silver magnesium (AgMg), silver copper (AgCu), silver palladium (AgPd), silver palladium copper (AgPdCu), and silver indium (AgIn).

Further, when the transparent conductive film is composed of a metal thin film, the thickness of the transparent conductive film is preferably in the range of 5 to 20 nm. When the thickness is thinner than 20 nm, the absorption component or the reflection component of the layer is small, and the transmittance of the transparent conductive film is large. Further, when the thickness is thicker than 5 nm, the conductivity of the layer can be sufficiently ensured.

Examples of the conductive conductive film having high reflectance in the first electrode 22 and the second electrode 24 include metal, alloy, organic or inorganic conductive compound, and a mixture thereof. Specifically, gold, aluminum, silver, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, indium, lithium / aluminum mixture, rare earth metal, indium-doped tin oxide ( It is preferable to select a material having good reflection characteristics from oxide semiconductors such as ITO), ZnO, TiO ₂ , and SnO ₂ . As the conductive film having high reflectance, the thickness is usually selected in the range of 5 nm to 5 μm, preferably 5 nm to 200 nm.

As the film forming method of the first electrode 22 and the second electrode 24, a method using a wet process such as a coating method, an inkjet method, a coating method, a dip method, a vapor deposition method (resistive heating, EB method, etc.), a sputtering method, etc. Examples thereof include a method using a dry process such as a CVD method.

[Light emitting unit]
The light emitting unit 23 is a layer including a light emitting layer made of at least an organic material. The overall layer structure of the light emitting unit 23 is not particularly limited, and a general layer structure can be applied. An example of the light emitting unit 23 applicable to the organic EL light emitting device 20 is shown below.

(I) Hole injection transport layer / light emitting layer / electron injection transport layer (ii) Hole injection transport layer / first light emitting layer / second light emitting layer / electron injection transport layer (iii) Hole injection transport layer / first Light emitting layer / intermediate layer / second light emitting layer / electron injection transport layer (iv) Hole injection transport layer / light emitting layer / hole blocking layer / electron injection transport layer (v) Hole injection transport layer / electron blocking layer / light emission Layer / hole blocking layer / electron injection transport layer (vi) hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer (vii) hole injection layer / hole transport layer / light emitting layer / Hole blocking layer / electron transporting layer / electron injection layer (viii) Hole injection layer / hole transporting layer / electron blocking layer / light emitting layer / hole blocking layer / electron transporting layer / electron injection layer

In the configurations (ii) and (iii) above, the first light emitting layer and the second light emitting layer may be each color light emitting layer that generates light emitted in each wavelength region. Further, in the configuration of (iii) above, the intermediate layer arranged between the first light emitting layer and the second light emitting layer may be non-light emitting and may function as a hole blocking layer and an electron blocking layer. Good.

The light emitting unit 23 has a configuration in which [hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer] are laminated in order from the electrode side used as the anode among the first electrode 22 and the second electrode 24. Illustrated as. The details of each layer will be described below.

(Light emitting layer)
The light emitting layer is a layer in which electrons injected from the cathode side and holes injected from the anode side recombine to emit light, and the light emitting portion is adjacent to the light emitting layer even within the light emitting layer. It may be an interface with a layer to be formed. The total thickness of the light emitting layer is preferably in the range of 1 to 100 nm, and more preferably in the range of 1 to 40 nm because a lower driving voltage can be obtained. The total thickness of the light emitting layer is the thickness including the non-light emitting intermediate layer when there is a non-light emitting intermediate layer between the light emitting layers.

However, in the case of a so-called tandem element in which a plurality of light emitting layer units are laminated via an intermediate connector portion, the light emitting layer referred to here refers to a light emitting layer portion in each light emitting unit. In the case of a configuration in which a plurality of light emitting layer units are laminated, the thickness of each light emitting layer is preferably adjusted within the range of 1 to 50 nm, and further adjusted within the range of 1 to 20 nm. preferable. When the plurality of laminated light emitting layers correspond to the respective light emitting colors of blue, green, and red, there is no particular limitation on the relationship between the thicknesses of the blue, green, and red light emitting layers.

The light emitting layer contains a host compound (also referred to as a light emitting host or the like) and a light emitting material (also referred to as a light emitting dopant), and preferably emits light from the light emitting material. Further, it is preferable that a phosphorescent compound is contained as a light emitting material. As the light emitting material, a fluorescent material may be used, or a phosphorescent light emitting compound and a fluorescent material may be used in combination. The structure of the light emitting layer is not particularly limited as long as the contained light emitting material satisfies the light emitting requirements. Further, there may be a plurality of layers having the same emission spectrum and emission maximum wavelength. In this case, it is preferable to have a non-luminescent intermediate layer (not shown) between the light emitting layers.

Examples of the luminescent dopant include International Publication No. 2005/076380, International Publication No. 2010/032663, International Publication No. 2008/140115, International Publication No. 2007/052431, International Publication No. 2011/134013, and International Publication No. 2011/157339, International Publication 2010/086089, International Publication No. 2009/1163646, International Publication No. 2012/20327, International Publication No. 2011/051404, International Publication No. 2011/004639, International Publication No. 2011 / 073149, Japanese Patent Application Laid-Open No. 2012-069737, Japanese Patent Application Laid-Open No. 2009-114086, Japanese Patent Application Laid-Open No. 2003-81988, Japanese Patent Application Laid-Open No. 2002-302671, JP-A-2002-363552, and the like. be able to.

Examples of the host compound include JP-A-2001-257076, JP-A-2002-308855, JP-A-2001-313179, JP-A-2002-319491, and JP-A-2001-357977. Kai 2002-334786, JP-2002-8860, JP-2002-334787, JP-A-2002-15871, JP-A-2002-334788, JP-A-2002-43056, JP-A-2002 -334789, 2002-75645, 2002-338579, 2002-105445, 2002-343568, 2002-141173, 2002-352957 No., JP-A-2002-203683, JP-A-2002-363227, JP-A-2002-231453, JP-A-2003-3165, JP-A-2002-234888, JP-A-2003-27048 , JP-A-2002-255934, JP-A-2002-260861, JP-A-2002-280183, JP-A-2002-299060, JP-A-2002-302516, JP-A-2002-305083, Kai 2002-305084, JP-A-2002-308387, US Patent Publication No. 2003/01755553, US Patent Publication No. 2006/0280965, US Patent Publication No. 2005/0112407, US Patent Publication No. 2009/0017330, US Patent Publication No. 2009/0030202, US Patent Publication No. 2005/238919, International Publication No. 2001/039234, International Publication No. 2009/021126, International Publication No. 2008/056746, International Publication No. 2004/093207, International Publication No. 2005/089025, International Publication No. 2007/0637996, International Publication No. 2007/0637554, International Publication No. 2004/107822, International Publication No. 2005 / 030900, International Publication No. 2006/114966, International Publication No. 2009/086028, International Publication No. 2009/003898, International Publication No. 2012/0293947, JP-A-2008-074939, JP-A-2007-254297 , EP No. 2034538 and the like. To.

The light emitting layer can be formed by forming a film of a known light emitting material or host compound by a known thin film forming method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, or an inkjet method. Further, the light emitting layer may be formed by mixing a plurality of light emitting materials.

(Hole injection layer / electron injection layer)
The injection layer is a layer provided between the electrode and the light emitting layer in order to reduce the driving voltage and improve the light emitting brightness, and is "organic EL element and its forefront of industrialization (November 30, 1998, NTS). (Issue) ”, Volume 2, Chapter 2,“ Electrode Materials ”(pages 123-166), the details of which are described.

The injection layer includes a hole injection layer and an electron injection layer, each of which can be provided as needed. If it is a hole injection layer, it may be present between the anode and the light emitting layer or the hole transport, and if it is an electron injection layer, it may be present between the cathode and the light emitting layer or the electron transport layer.

The details of the hole injection layer are described in JP-A-9-45479, JP-A-9-2660062, JP-A-8-288609, etc., and as a specific example, a phthalocyanine layer represented by copper phthalocyanine. , Oxide layer typified by vanadium oxide, amorphous carbon layer, polymer layer using conductive polymer such as polyaniline (emeraldine) and polythiophene, and the like. It is also preferable to use the materials described in JP-A-2003-591432.

The details of the electron injection layer are described in JP-A-6-325871A, JP-A-9-17574, JP-A-10-74586, etc., and specifically, strontium, aluminum, and the like are represented. Examples include a metal layer, an alkali metal halide layer typified by potassium fluoride, an alkaline earth metal compound layer typified by magnesium fluoride, and an oxide layer typified by molybdenum oxide. The electron injection layer is preferably a very thin film, and although it depends on the material, the thickness is preferably in the range of 1 nm to 10 μm.

(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 may be provided as a single layer or a plurality of layers.

The hole transporting material has any of the properties of hole injection, transport, and electron barrier property, and may be either an organic substance or an inorganic substance. For example, triazole derivatives, oxadiasol 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 stillben derivatives, silazane derivatives, aniline-based copolymers, and conductive polymer oligomers, especially thiophene oligomers.

As the hole transport material, the above-mentioned ones can be used, but it is more 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, for example, N, N, N', N'-tetraphenyl-4,4'-diaminophenyl, N, N'-diphenyl-N, N. ′ -Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4 ′-diamine (abbreviation: 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-trilaminophenyl) -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 (diphenyl) Amino) Quadriphenyl, N, N, N-tri (p-tolyl) amine, 4- (di-p-tolylamino) -4'-[4- (di-p-tolylamino) styryl] stilben, 4-N , N-diphenylamino- (2-diphenylvinyl) benzene, 3-methoxy-4'-N, N-diphenylaminostillbenzene, N-phenylcarbazole, as described in US Pat. No. 5,061,569. Those having two fused aromatic rings in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (abbreviation: NPD), JP-A-4- 4,4', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in JP-A-308688 are linked in a starburst form ( Abbreviation: 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. Inorganic compounds such as p-type-Si and p-type-SiC can also be used as hole injection materials and hole transport materials.

In addition, JP-A-11-251667, J. Am. Hung et. al. , Applied Physics Letters, 80 (2002), p. So-called p-type hole transport materials such as those described in 139 can also be used. It is preferable to use these materials because a light emitting device with higher efficiency can be obtained.

The hole transport layer is 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 inkjet method, or an LB method. Can be done. 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 one-layer structure composed of one type or two or more types of the above materials.

Further, the material of the hole transport layer can be doped with impurities to improve the transportability. Examples thereof include JP-A-4-297076, JP-A-2000-196140, JP-A-2001-102175, J. Mol. Apple. Phys. , 95, 5773 (2004) and the like.

(Electronic 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 structure or a multi-layer laminated structure.

In the single-layer structure electron transport layer and the laminated structure electron transport layer, as an electron transport material (also serving as a hole blocking material) constituting a layer portion adjacent to the light emitting layer, electrons injected from the cathode are emitted. It suffices to have a function of transmitting to the layer. As such a material, any one can be selected and used from conventionally known compounds. Examples thereof include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, carbodiimides, freolenidene methane derivatives, anthracinodimethane, anthrone derivatives and oxadiazole derivatives. Further, among the above oxadiazole derivatives, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is replaced with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron-withdrawing group can also be used as a material for the electron transport layer. it can. 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.

Also, metal complexes of 8-quinolinol derivatives, such as tris (8-quinolinol) aluminum (abbreviation: Alq3), 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 (abbreviation: Znq), etc., and the central metal of these metal complexes A metal complex replaced with In, Mg, Cu, Ca, Sn, Ga, or Pb can also be used as a material for the electron transport layer.

In addition, metal-free or metal phthalocyanines, or those whose terminals are substituted with an alkyl group, a sulfonic acid group, or the like can also be preferably used as a material for the electron transport layer. Further, a distyrylpyrazine derivative exemplified as a material of a light emitting layer can also be used as a material of an electron transport layer, and like the hole injection layer and the hole transport layer, n-type-Si, n-type-SiC and the like can be used. Inorganic semiconductors can also be used as materials for electron transport layers.

The electron transport layer can be formed by thinning the material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an inkjet 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 one-layer structure composed of one type or two or more types of the above materials.

Further, the electron transport layer can be doped with impurities to improve the transportability. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, JP-A-2001-102175, J. Mol. Apple. Phys. , 95, 5773 (2004) and the like. Further, it is preferable that the electron transport layer contains potassium, a potassium compound, or the like. As the potassium compound, for example, potassium fluoride or the like can be used. By increasing the n property of the electron transport layer in this way, a device having lower power consumption can be manufactured.

Further, as the material of the electron transport layer (electron transport compound), the same material as the material constituting the base layer described above may be used. This also applies to an electron transport layer that also serves as an electron injection layer, and the same material as the material constituting the base layer described above may be used.

(Blocking layer)
Examples of the blocking layer include a hole blocking layer and an electron blocking layer, and the light emitting unit 23 may be further provided in addition to the above functional layers. For example, described in JP-A-11-204258, JP-A-11-204359, and page 237 of "Organic EL Element and Its Industrialization Frontline (November 30, 1998, published by NTS)". There is a hole blocking (hole block) layer.

The hole blocking layer has a function of an electron transporting layer in a broad sense. The hole blocking layer is made of a hole blocking material that has a function of transporting electrons and a significantly small ability to transport holes, and recombines electrons and holes by blocking holes while transporting electrons. The probability can be improved. In addition, the structure of the electron transport layer can be used as a hole blocking layer, if necessary. The hole blocking layer is preferably provided adjacent to the light emitting layer.

On the other hand, the electron blocking layer has a function of a hole transporting layer in a broad sense. The electron blocking layer is made of a material that has a function of transporting holes and a significantly small ability to transport electrons, and improves the probability of recombination of electrons and holes by blocking electrons while transporting holes. be able to. In addition, the structure of the hole transport layer can be used as an electron blocking layer, if necessary. The thickness of the hole blocking layer is preferably in the range of 3 to 100 nm, and more preferably in the range of 5 to 30 nm.

[Sealing member]
In the organic EL light emitting device 20, the organic EL element 25 may be sealed with a sealing member (not shown) for the purpose of preventing deterioration of the light emitting unit 23 configured by using an organic material or the like. The sealing member is a plate-shaped (film-shaped) member that covers the upper surface of the organic EL element 25, and is fixed to the second base material 21 side by an adhesive portion. Further, the sealing member may be a sealing film. Such a sealing member is provided so as to expose the electrode terminal portion of the organic EL element 25 and at least cover the light emitting unit 23. Further, an electrode may be provided on the sealing member so that the electrode terminal portion of the organic EL element 25 and the electrode of the sealing member are made conductive.

Examples of the material constituting the plate-shaped (film-shaped) sealing member include a glass plate, a polymer plate / film, a metal plate / film, and the like. Examples of the glass plate include soda lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone. Examples of the metal plate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium and tantalum. Since the element can be thinned, a thin film-shaped polymer substrate or metal substrate can be preferably used as the sealing member.

Furthermore, the polymer substrate having a film shape is used as a sealing member, the measured oxygen permeability by the method based on JIS K 7126-1987 is ^{1 × 10-3ml / (m 2 ·} 24h · atm) or less, JIS K water vapor permeability measured by the method conforming to 7129-1992 (25 ± 0.5 ℃, relative humidity (90 ± 2)% RH) is located at ^{1 × 10 -3 g / (m} 2 · 24h) or less Is preferable.

Further, the substrate material as described above may be processed into an intaglio shape and used as a sealing member. In this case, the above-mentioned substrate member can be processed into an intaglio shape by performing processing such as sandblasting and chemical etching.

Further, the adhesive for fixing the plate-shaped sealing member to the second base material 21 side is for sealing the organic EL element 25 sandwiched between the sealing member and the second base material 21. Used as a sealant. Specific examples of such adhesives include acrylic acid-based oligomers, photocurable and thermosetting adhesives having a reactive vinyl group of methacrylic acid-based oligomers, and moisture-curable adhesives such as 2-cyanoacrylic acid ester. Adhesives can be mentioned. Further, as the adhesive, a heat and chemical curing type (two-component mixture) such as an epoxy type can be mentioned. Further, hot melt type polyamide, polyester and polyolefin can be mentioned. In addition, a cation-curable type ultraviolet-curable epoxy resin adhesive can be mentioned. A commercially available dispenser may be used for applying the adhesive to the adhesive portion between the sealing member and the second base material 21, or printing may be performed as in screen printing.

The organic material constituting the organic EL element 25 may be deteriorated by heat treatment. Therefore, the adhesive is preferably one that can be adhesively cured from room temperature to 80 ° C. Further, the desiccant may be dispersed in the adhesive.

When a gap is formed between the plate-shaped sealing member, the second base material 21, and the adhesive, the gas phase or liquid phase of the gap may contain an inert gas such as nitrogen or argon, or a foot. It is preferable to inject an inert liquid such as a chemical hydrocarbon or silicon oil. It is also possible to create a vacuum. It is also possible to enclose a hygroscopic compound inside.

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

On the other hand, when a sealing film is used as the sealing member, the light emitting unit 23 in the organic EL element 25 is completely covered, and the terminal portions of the first electrode 22 and the second electrode 24 in the organic EL element 25 are exposed. A sealing film is provided on the second base material 21.

Such a sealing film is constructed by using an inorganic material or an organic material. In particular, it is made of a material having a function of suppressing the infiltration of substances such as water and oxygen that cause deterioration of the light emitting unit 23 in the organic EL element 25. As such a material, for example, an inorganic material such as silicon oxide, silicon dioxide, or silicon nitride is used. Further, in order to improve the brittleness of the sealing film, a film made of an organic material may be used together with the film made of these inorganic materials to form a laminated structure.

The method for forming these films is not particularly limited, and 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 and the like can be used.

[Manufacturing method of organic EL light emitting device]
Next, an example of the manufacturing method of the organic EL light emitting device 20 shown in FIG. 2 will be described.
First, the second base material 21 is prepared. Then, the first electrode 22 is formed on the first main surface of the second base material 21 by an appropriate film forming method such as a vapor deposition method or a sputtering method. Then, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like are formed in this order on the first electrode 22, and a light emitting unit 23 is formed. As a film forming method for each of these layers, conventionally known conditions can be appropriately selected.

After forming the light emitting unit 23, the second electrode 24 is formed on the upper portion by an appropriate film forming method such as a thin film deposition method or a sputtering method. At this time, the second electrode 24 is formed into a pattern in which the terminal portion is pulled out from above the light emitting unit 23 to the peripheral edge of the second base material 21 while maintaining the insulated state with respect to the first electrode 22 by the light emitting unit 23. .. As a result, the organic EL element 25 is manufactured. Further, after that, a sealing member that covers at least the light emitting unit 23 is provided in a state where the terminal portion of the extraction electrode in the organic EL element 25 is exposed.

Further, apart from the production of the organic EL element 25, the light extraction film 10 is produced by the above-mentioned production method. Then, the release film on the pressure-sensitive adhesive layer 14 is peeled off, and the pressure-sensitive adhesive layer 14 of the light extraction film 10 is attached to the second main surface side of the second base material 21 of the organic EL element 25. Further, if necessary, the pressure-sensitive adhesive in the pressure-sensitive adhesive layer 14 is heated in a vacuum atmosphere of 1000 Pa or less, or irradiated with energy rays.
Through the above steps, the organic EL light emitting device 20 including the organic EL element 25 and the light extraction film 10 can be manufactured.

The thickness of the light extraction film 10 used in the organic EL light emitting device 20 is smaller than that of the conventional gas barrier film and the light extraction film bonded together. Therefore, also in the organic EL light emitting device 20, when the organic EL element 25 is cut out, damage such as cracking in the gas barrier layer 12 due to cutting can be suppressed. Therefore, it is possible to suppress a decrease in the reliability of the organic EL element 25 due to a decrease in the gas barrier property.

Further, in the production of the organic EL light emitting device 20, the light extraction film 10 having a structure in which the generation of warpage (curl) is suppressed is used. Therefore, when the organic EL element 25 and the light extraction film 10 are attached to each other, the workability is less likely to decrease and the productivity is improved.

In the above-described embodiment of the organic EL light emitting device, the bottom emission type organic EL light emitting device that extracts light from the base material side of the organic EL element has been described, but the light extraction film is similarly applied to other forms. be able to. For example, in the case of a top emission type organic EL light emitting device, the second electrode can be formed of a transparent conductive film, and a light extraction film can be provided on the sealing member. Further, in the case of a double-sided light emitting type organic EL light emitting device, both the first electrode and the second electrode are made of a transparent conductive film, and a light extraction film is provided on both sides of the second base material and the sealing member. be able to.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto. Although the display of "%" is used in the examples, it represents "mass%" unless otherwise specified.

<Preparation of organic EL light emitting device for sample 101>
[Manufacturing of organic EL device; preparation of base material with gas barrier layer]
A polyethylene terephthalate film having a thickness of 125 μm (manufactured by Teijin DuPont Film Co., Ltd., PET Type K, an ultra-highly transparent product) was prepared as a base material (second base material) for an organic EL element. Then, using an atmospheric pressure plasma film forming apparatus (Samco plasma CVD apparatus Model PD-270STP), silicon oxide is formed on a base material (second base material) under the following thin film forming conditions by the atmospheric pressure plasma method. A barrier layer (thickness 270 nm) was formed. As a result, a base material with a gas barrier layer was prepared.

(Mixed gas composition)
Discharge gas: Nitrogen gas 94.9% by volume
Thin film forming gas: Tetraethoxysilane 0.1% by volume
Addition gas: Oxygen gas 5.0% by volume

(Film formation conditions; 1st electrode side)
Power supply type: Haiden Research Institute 100kHz (continuous mode) PHF-6k
Frequency: 100kHz
Output density: 10 W / cm ²
Electrode temperature: 130 degrees (deposition condition; second electrode side)
Power supply type: Pearl Industry 13.56MHz CF-5000-13M
Frequency: 13.56MHz
Output density: 10 W / cm ²
Electrode temperature: 100 degrees

[Manufacturing of organic EL element; Fabrication of base layer to second electrode]
The base material was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone washed for 5 minutes, and then the base material was fixed to a substrate holder of a commercially available vacuum vapor deposition apparatus. Each of the crucibles for vapor deposition in the vacuum vapor deposition apparatus was filled with the constituent materials of each layer in the optimum amount for manufacturing the device. As the crucible for vapor deposition, a crucible made of molybdenum or tungsten made of a resistance heating material was used.

(Formation of base layer)
The following compound R-1 was deposited on the barrier layer of the base material with a barrier layer to a thickness of 25 nm by a known vapor deposition method to form an underlayer (not shown).

(Formation of the first electrode)
Next, silver was vapor-deposited on the base layer to a thickness of 15 nm by a thin-film deposition method to form a first transparent electrode (anode: thin silver electrode).

(Formation of light emitting unit)
After reducing the vacuum to 1 × 10 ^-4 Pa, the crucible for vapor deposition containing compound M-4 is energized and heated, and the film is deposited on a transparent support substrate at a vapor deposition rate of 0.1 nm / sec to a positive film thickness of 15 nm. A hole injection layer was formed.
Next, compound M-2 was vapor-deposited at a vapor deposition rate of 0.1 nm / sec to form a hole transport layer having a film thickness of 130 nm.
Next, using compound BD-1 and compound H-1, co-deposited at a vapor deposition rate of 0.1 nm / sec so that compound BD-1 has a concentration of 5% and compound H-1 has a concentration of 95%. A fluorescent light emitting layer (light emitting layer) exhibiting blue light emission having a film thickness of 50 nm was formed.
Next, using compound GD-1, compound RD-1 and compound H-2, compound GD-1 has a concentration of 17%, RD-1 has a concentration of 0.8%, and compound H-2 has a concentration of 82.2%. Co-deposited at a vapor deposition rate of 0.1 nm / sec so as to have a concentration of 85 nm, a phosphorescent light emitting layer (light emitting layer) exhibiting yellow light emission having a film thickness of 85 nm was formed.
Then, compound E-1 was vapor-deposited at a vapor deposition rate of 0.1 nm / sec to form an electron transport layer having a film thickness of 35 nm.

(Formation of the second electrode)
Further, LiF was vapor-deposited so as to have a film thickness of 2 nm to form a LiF layer which is an electron injection layer.
Then, 110 nm of aluminum was vapor-deposited to form a second electrode (cathode).

[Manufacturing of organic EL element; sealing]
Similar to the above-mentioned base material with a gas barrier layer, the atmospheric pressure plasma method is used on a 125 μm-thick polyethylene terephthalate film (manufactured by Teijin DuPont Film Co., Ltd., ultra-high transparent PET Type K) under the same conditions as above. A gas barrier layer was formed to obtain a transparent sealed substrate with a gas barrier layer.

The transparent sealing substrate is adhered using an epoxy-based heat-curable adhesive (Elephant CS manufactured by Tomagawa Paper Manufacturing Co., Ltd.) as an adhesive in a glove box having an oxygen concentration of 10 ppm or less and a water concentration of 10 ppm or less at 80 ° C. Under a load of 04 MPa, under the conditions of depressurization (1 × 10 ^-3 MPa or less) suction for 20 seconds and pressing for 20 seconds, the gas barrier layer of the transparent sealing member becomes the organic EL element side toward the organic EL element. Vacuum pressed.
Then, in the glove box, the adhesive layer was thermoset by heating on a hot plate at 110 ° C. for 30 minutes to prepare an organic EL element.

[Preparation of light extraction film; base material]
Similar to the above-mentioned base material with a gas barrier layer used for manufacturing the organic EL element, the same conditions as above are applied on a polyethylene terephthalate film (manufactured by Teijin DuPont Film Co., Ltd., ultra-high transparent product PET Type K) having a thickness of 5 μm. Then, the gas barrier layer was formed by using the atmospheric pressure plasma method to prepare the base material (first base material) of the light extraction film and the gas barrier layer.

[Preparation of light extraction film; light scattering layer]
Next, a light scattering layer was prepared by the following method on the surface of the light extraction film on which the gas barrier layer was not formed.

(Light scattering layer)
The solid content ratio of TiO ₂ particles (JR600A manufactured by Teika Co., Ltd.) having a refractive index of 2.4 and an average particle size of 350 nm and a resin solution (230AL (organic-inorganic hybrid resin) manufactured by Lhasa Industries) is 50% by volume / 50 volumes. With an organic solvent in which the solvent ratio of 2-propanol, propylene glycol monomethyl ether (PGME), and 2-methyl-2,4-pentanediol (PD) is 20% by volume / 40% by volume / 40% by volume. The solution was prepared so that the solid content concentration was 12% by mass.
To the above solid content (effective mass component), 0.4% by mass of an additive (Disperbyk-2096 manufactured by Big Chemie Japan Co., Ltd.) was added, and a formulation was designed in a ratio of 10 ml.

Specifically, the TiO ₂ particles and an organic solvent and additives were mixed with 10% by weight ratio with respect to TiO ₂ particles, while cooling at room temperature (25 ° C.), an ultrasonic dispersing machine (manufactured by SMT Co., Ltd. UH -50) was dispersed for 10 minutes under the standard conditions of a microchip step (MS-3 3 mmφ manufactured by SMT) to prepare a TiO ₂ dispersion.
Next, while stirring the TiO ₂ dispersion at 100 rpm, the resin solution was mixed and added little by little. After the addition was completed, the stirring speed was increased to 500 rpm, and after mixing for 10 minutes, the hydrophobic PVDF 0.45 μm filter (manufactured by Whatman Co., Ltd.) ) Was filtered to obtain the desired coating solution for the light scattering layer.

After applying the above coating liquid on a resin base material by an inkjet coating method, it is simply dried (70 ° C., 2 minutes), and further, it is used for 5 minutes under output conditions where the base material temperature is less than 80 ° C. by wavelength control IR described later. A drying process was performed. Further, the curing reaction was promoted under the following modification treatment conditions to prepare a light scattering layer having a thickness of 25 μm.

(Reform processing equipment)
Equipment: Excimer irradiation device MODEL MECL-M-1-200 manufactured by MD.com Co., Ltd.
Irradiation wavelength: 172 nm
Lamp-filled gas: Xe

(Modification treatment conditions)
Excimer lamp light intensity: 130 mW / cm ² (172 nm)
Distance between sample and light source: 2 mm
Stage heating temperature: 70 ° C
Oxygen concentration in the irradiator: 20.0%
Irradiation energy: 8J / cm ²

[Preparation of light extraction film; preparation and bonding of adhesive layer]
On the gas barrier layer of the light extraction film produced above, SK Dyne 2147 manufactured by Soken Chemical Co., Ltd. was applied to a thickness of 20 μm to form an adhesive layer. Then, the pressure-sensitive adhesive layer of the light extraction film was attached to the back surface side of the base material of the organic EL element produced by the above method. After that, the organic EL element and the light extraction film were bonded together under the conditions of a transport speed of 3 m / min, a tension of the laminate of 110 N / m, and a nip pressure of 25 kPa to prepare an organic EL light emitting device for sample 101.

<Preparation of organic EL light emitting device for samples 102 to 121>
The thickness of the base material, the thickness of the light scattering layer, and the ratio of the thickness of the pressure-sensitive adhesive layer to the thickness of the light-scattering layer [adhesive layer / light-scattering layer] in the light extraction film are shown in Table 1 below. The organic EL light emitting device of the sample 121 was produced from the sample 102 by the same method as the organic EL light emitting device of the sample 101 described above by changing as shown.

<Evaluation method>
The following evaluations were performed on the light extraction film of the prepared samples 101-121 and the organic EL light emitting device.

[Evaluation of viewing angle dependence / front brightness]
Regarding the manufactured organic EL light emitting device, the spectroscopic reflection luminance meter CS-2000 (manufactured by Konica Minolta) under the condition of a constant current of 5 mA / cm ² within an angle range of -80 ° to 80 ° as a viewing angle every 5 °. The brightness and emission spectrum were measured using. Next, the obtained emission spectrum was converted into chromaticity coordinates x and y by the CIE1931 color system.

(Viewing angle dependence)
The change length of the chromaticity coordinates at an angle of 70 ° with the front surface was expressed as ΔExy. The larger ΔExy, the larger the color shift. The evaluation was relative evaluation with the value of sample 112 as 100. When the evaluation exceeds 100, it means that the color shift becomes large. Further, as a judgment criterion, when the evaluation exceeds 110, it can be judged that the color deviation is remarkably large.

(Front brightness)
The brightness of the front surface was relatively evaluated with the value of sample 112 as 100. When the brightness exceeds 100, it means that the brightness becomes brighter and improves.

[Evaluation of edge barrier cracks]
After individually cutting the prepared light extraction film with a cutting machine, the end face was observed with an optical microscope, and the depth of barrier cracking was evaluated as follows.
A: No occurrence B: Slight occurrence (≦ 10 μm)
C: Slightly generated (≤50 μm)
D: Occurrence (≧ 50 μm)

[Evaluation of curl]
The prepared light extraction film was subjected to 10 cm sq. The convex side of the cut light extraction film was placed on a flat plate surface, and the average heights from the flat plate surfaces at the four corners of the light extraction film were measured and evaluated as follows.
A: Height 0
B: Height ≤ 1.0 mm
C: 1.0 ≤ height <2.0 mm
D: Height ≥ 2.0 mm

Table 1 shows the configurations of the organic EL light emitting devices of the samples 101 to 121 and the evaluation results of each.

[Evaluation results]
As shown in Table 1, the light extraction film of the samples 101 to 105 having a base material thickness of 5 μm has a large curl. Further, in the light extraction films of the samples 118 to 121 having a base material thickness of 65 μm, the gas barrier layer is cracked at the time of cutting. Further, in the sample 106 and the sample 110 in which the ratio of the thickness of the pressure-sensitive adhesive layer to the light scattering layer is 0.8, and in the sample 114 in which the ratio of the thickness of the pressure-sensitive adhesive layer to the light scattering layer is 4. , The curl is big.

On the other hand, in each sample in which the thickness of the base material is 10 to 60 μm and the ratio of the thickness of the adhesive layer to the thickness of the light scattering layer is 1 to 3, curling occurs and the gas barrier layer is cracked. Good results have been obtained in the evaluation of.
Therefore, by setting the thickness of the base material of the light extraction film to 10 μm or more and 60 μm or less and the ratio of the thickness of the pressure-sensitive adhesive layer to the thickness of the light scattering layer to 1 to 3, the warp (curl) of the light extraction film is set. It is possible to realize a light extraction film capable of suppressing the occurrence of light and cracking of the gas barrier layer at the time of cutting.

Further, the smaller the thickness of the light scattering layer, the larger the value of the viewing angle dependence evaluation of the organic EL light emitting device, and the larger the thickness of the light scattering layer, the larger the value of the viewing angle dependence evaluation of the organic EL light emitting device. Tended to be smaller. That is, in the organic EL light emitting device, the angle-dependent color shift can be reduced by increasing the thickness of the light scattering layer.

On the other hand, the smaller the thickness of the light scattering layer, the larger the front luminance of the organic EL light emitting device, and the larger the thickness of the light scattering layer, the smaller the front luminance of the organic EL light emitting device. That is, in the organic EL light emitting device, the front luminance can be increased by reducing the thickness of the light scattering layer. Further, if the thickness of the light scattering layer is too small as in the sample 114, the effect of light scattering becomes small and the front luminance becomes small.
Therefore, the thickness of the light scattering layer is preferably 6 μm or more and 20 μm or less.

<Preparation of organic EL light emitting device for samples 201 to 205>
Table 2 below shows the thickness of the base material, the thickness of the light scattering layer, and the ratio of the thickness of the adhesive layer to the thickness of the light scattering layer [adhesive layer / light scattering layer] in the light extraction film. By changing as shown, the organic EL light emitting device of the sample 201 to the sample 205 was produced by the same method as the organic EL light emitting device of the sample 101 described above.

<Evaluation method>
The light extraction film of the prepared samples 201 to 205 and the organic EL light emitting device were evaluated for viewing angle dependence / front luminance, curl, and edge barrier cracking in the same manner as in Example 1 above. I did. The evaluation of the viewing angle dependence and the front luminance was made relative to each other with the value of the sample 112 described above as 100.

Table 2 shows the configurations of the organic EL light emitting devices of the samples 201 to 205 and the evaluation results of each. For comparison, Table 2 shows the configuration of the organic EL light emitting device of the sample 112 and the evaluation results together.

As shown in Table 2, the light extraction film of sample 201 having a relatively large pressure-sensitive adhesive layer thickness of 35 μm and sample 205 having a relatively small pressure-sensitive adhesive layer thickness of 8 μm has slight curl. There is. Further, the light extraction film of the sample 202 to the sample 204 having a relatively small light scattering layer thickness of 4 μm also causes a slight curl regardless of the ratio of the thickness of the adhesive layer to the thickness of the light scattering layer. ing.
From this result, when the thickness of the pressure-sensitive adhesive layer is too large or too small, and when the thickness of the light scattering layer is too small, the curl is determined by the thickness of the pressure-sensitive adhesive layer and the thickness of the light scattering layer. It becomes difficult to adjust depending on the ratio. Therefore, in order to facilitate the suppression of warpage (curl) of the light extraction film, the thickness of the light scattering layer is preferably 5 μm or more and 30 μm or less, and the thickness of the pressure-sensitive adhesive layer is 10 μm or more and 30 μm or less. Is preferable. Further, as in Example 1 described above, the smaller the thickness of the light scattering layer, the larger the value of the viewing angle dependence evaluation and the front luminance of the organic EL light emitting device, and the larger the thickness of the light scattering layer. The value of the viewing angle dependence evaluation and the front brightness of the organic EL light emitting device become smaller. Therefore, the thickness of the light scattering layer is more preferably 6 μm or more and 20 μm or less.

The present invention is not limited to the configuration described in the above-described embodiment, and various modifications and changes can be made without departing from the configuration of the present invention.

10 ... Light extraction film, 11 ... Base material (first base material), 12 ... Gas barrier layer, 13 ... Light scattering layer, 14 ... Adhesive layer, 20 ... Organic EL Light emitting device, 21 ... 2nd base material, 22 ... 1st electrode, 23 ... light emitting unit, 24 ... 2nd electrode, 25 ... organic EL element

Claims (5)

With the base material
A gas barrier layer formed on one surface of the base material and
A light scattering layer formed on the other surface of the base material and
The pressure-sensitive adhesive layer formed on the gas barrier layer is provided.
The thickness of the base material is 10 μm or more and 60 μm or less.
A light extraction film in which the thickness of the pressure-sensitive adhesive layer is 1 to 3 times the thickness of the light scattering layer. The light extraction film according to claim 1, wherein the thickness of the light scattering layer is 5 μm or more and 30 μm or less. The light extraction film according to claim 1, wherein the thickness of the pressure-sensitive adhesive layer is 10 μm or more and 30 μm or less. The light extraction film according to claim 1, wherein the total thickness of the light extraction film is 25 μm or more and 110 μm or less. It has an organic electroluminescence element and a light extraction film.
The light extraction film
With the first base material
A gas barrier layer formed on one surface of the first base material and
A light scattering layer formed on the other surface of the first base material and
The pressure-sensitive adhesive layer formed on the gas barrier layer is provided.
The organic electroluminescence element
With the second base material
A first electrode formed on one surface of the second base material and
The light emitting unit formed on the first electrode and
A second electrode formed on the light emitting unit is provided.
The light extraction film is attached to the second base material by the pressure-sensitive adhesive layer,
The thickness of the first base material is 10 μm or more and 60 μm or less.
An organic electroluminescent light emitting device in which the thickness of the pressure-sensitive adhesive layer is 1 to 3 times the thickness of the light scattering layer.

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