JP5515799B2 - Laminate for surface light source device and surface light source device - Google Patents

Description

  The present invention relates to a laminate for a surface light source device and a surface light source device. Specifically, the present invention relates to a surface light source device having an organic electroluminescence element (hereinafter referred to as “organic EL element”) and a laminate for a surface light source device useful as a component thereof.

  An organic EL device that provides an organic light emitting layer between multiple layers of electrodes to obtain light emission is used as a display device instead of a liquid crystal cell, as well as its high luminous efficiency, low voltage drive, light weight, low cost, etc. Utilization of the above features is also being considered for use as a planar light source device such as a flat illumination and a backlight for a liquid crystal display device.

  When an organic EL element is used as a light source of a surface light source device, it is known to provide various uneven structures on the light extraction surface side of the light emitting element of the light source in order to extract useful light from the element with high efficiency. (For example, FIG. 4, FIG. 6, etc. of patent document 1). Further, as a gas barrier film for preventing moisture deterioration of the organic EL element, a laminated film formed by a vapor deposition method using an arc discharge plasma method or a chemical vapor deposition method has been proposed. (For example, Patent Document 2)

JP 2009-266429 A JP 2005-178087 A

  When a film base that is advantageous for reducing the thickness and weight of the device is adopted as the base material constituting the light emitting element, etc., when a layer having a concavo-convex structure is provided on the film base, Therefore, there is a problem that the film base material is deteriorated and the quality of the obtained product can be reduced.

  In addition, in a device including an organic EL element, in order to extend the lifetime of the device, a structure in which the light emitting layer is sealed so that a component such as water vapor that deteriorates the light emitting layer in the outside air does not contact the light emitting layer is adopted. Is required. When the sealing function is applied to the film base material, a gas barrier layer made of a metal oxide such as silicon or aluminum can be provided on the film base material. There exists a problem that it peels easily by impacts, such as friction, in a process, and the quality of a product is impaired.

Accordingly, an object of the present invention is to provide a laminate for a surface light source device that can increase the light extraction efficiency of the surface light source device, has high mechanical strength, and has a high ability to seal components in the outside air such as water vapor. There is to do.
Another object of the present invention is to provide a surface light source device having high light extraction efficiency, high mechanical strength, and a long lifetime.

As a result of studies conducted by the present inventors to solve the above-mentioned problems, a laminate comprising a concavo-convex structure layer and a gas barrier layer in a predetermined manner is adopted as a laminate provided on the light exit surface side of the surface light source device. Thus, the present inventors have found that the above problems can be solved, and completed the present invention.
That is, according to the present invention, the following [1] to [7] are provided.

[1] A laminate for a surface light source device for constituting a light-emitting surface side layer of a surface light source device including an organic electroluminescence element,
A laminate for a surface light source device, comprising a concavo-convex structure layer having a concavo-convex structure on the surface, a first gas barrier layer, a film substrate, and a transparent electrode layer in this order.
[2] The laminate for a surface light source device according to claim 1, wherein the film substrate includes at least one layer of an alicyclic structure-containing polymer resin.
[3] The laminate for a surface light source device according to claim 1 or 2, further comprising a second gas barrier layer between the film substrate and the transparent electrode layer.
[4] The laminate for a surface light source device according to any one of claims 1 to 3, wherein the concavo-convex structure has a plurality of concave portions including slopes and flat portions positioned around the concave portions.
[5] The laminate for a surface light source device according to any one of claims 1 to 4, wherein the transparent electrode layer is formed of a metal thin film layer, and the sheet resistance value of the transparent electrode layer is 50Ω / □ or less.
[6] The laminate for a surface light source device according to claim 5, wherein the metal thin film layer includes a material selected from the group consisting of gold, silver, and a mixture thereof.
[7] A surface light source device comprising the laminate for a surface light source device according to any one of claims 1 to 6, a light emitting layer, and a reflective electrode layer in this order.

  The laminate for a surface light source device of the present invention can increase the extraction efficiency of light emitted from the concavo-convex structure layer, has high mechanical strength, and has a high ability to seal components in the outside air such as water vapor. Therefore, the surface light source device of the present invention including the laminate can be a surface light source device with high light extraction efficiency, high mechanical strength, and a long lifetime.

FIG. 1 is a perspective view schematically showing an example of a laminate for a surface light source device of the present invention. FIG. 2 is a cross-sectional view showing a cross section of the laminate for a surface light source device shown in FIG. 1 cut along a plane that passes through line 1a-1b in FIG. 1 and is perpendicular to the plane direction of the film substrate. FIG. 3 is a cross-sectional view schematically showing another example of the laminate for a surface light source device of the present invention. FIG. 4 is a partial top view schematically showing the structure of the surface 10U of the laminate 100 for surface light source device. FIG. 5 is a partial cross-sectional view showing a cross section of the concavo-convex structure layer 111 taken along a vertical plane passing through the line 10a in FIG. 6 is a partial cross-sectional view showing a modification of the recess shown in FIG. FIG. 7 is a partial cross-sectional view showing another modification of the recess shown in FIG. FIG. 8 is a perspective view schematically showing an example of the surface light source device of the present invention. FIG. 9 is a cross-sectional view showing a cross section of the surface light source device 10 shown in FIG. 8 cut along a plane that passes through the line 1a-1b in FIG. 7 and is perpendicular to the surface direction of the transparent substrate.

<Laminated body for surface light source device>
The laminate for a surface light source device of the present invention includes an uneven structure layer having an uneven structure on the surface, a first gas barrier layer, a film substrate, and a transparent electrode layer in this order.
FIG. 1 is a perspective view schematically showing an example of a laminate for a surface light source device of the present invention, and FIG. 2 shows the laminate for a surface light source device shown in FIG. 1 along a line 1a-1b in FIG. It is a sectional view showing a section cut along a plane perpendicular to the surface direction of the film substrate.

  The laminate 100 for a surface light source device includes an uneven structure layer 111, a first gas barrier layer 121, a film base 131, a second gas barrier layer 122, and a transparent electrode layer 141 in this order.

  The concavo-convex structure layer 111 has a concavo-convex structure including a plurality of recesses 113 and a flat part 114 positioned around the recesses 113 on the upper surface thereof. The uneven structure defines the surface 10U of the laminate 100 for the surface light source device. The surface 10U is a plane parallel to the other layers in the laminate for the surface light source device such as the flat portion 114 and the film base 131 when viewed macroscopically, ignoring the recess 113, but microscopically. It is an uneven surface including a slope defined by the recess 113. In the present application, since the drawings are schematic illustrations, only a small number of recesses are shown on the surface 10U. However, in an actual laminate, on the surface of a single laminate for a surface light source device. In addition, a much larger number of recesses can be provided.

(Film substrate)
The material of the film substrate is not particularly limited, and various resins that can form a transparent layer can be used. For example, a thermoplastic resin, a thermosetting resin, an ultraviolet curable resin, and an electron beam curable resin can be given. A thermoplastic resin is preferable because it can be easily processed. Examples of the thermoplastic resin include polyester-based resins, polyacrylate-based resins, and alicyclic structure-containing polymer resins, and alicyclic structure-containing polymer resins are particularly preferable.

  The alicyclic structure-containing polymer resin is a resin containing a polymer (cycloolefin polymer) containing an alicyclic structure. Such a resin can be particularly preferably used because it has a low water vapor transmission rate and a small amount of outgas emission under the conditions of the gas barrier layer, transparent electrode layer and other layer formation processes such as vapor deposition and sputtering. .

  The alicyclic structure-containing polymer resin is an amorphous resin having an alicyclic structure in the main chain and / or side chain. Examples of the alicyclic structure in the alicyclic structure-containing polymer resin include a saturated alicyclic hydrocarbon (cycloalkane) structure and an unsaturated alicyclic hydrocarbon (cycloalkene) structure. However, mechanical strength, heat resistance, etc. From this viewpoint, a cycloalkane structure is preferable. The number of carbon atoms constituting the alicyclic structure is not particularly limited, but is usually 4 to 30, preferably 5 to 20, more preferably 5 to 15, when the mechanical strength, heat resistance, In addition, the moldability characteristics of the film are highly balanced and suitable. The ratio of the repeating unit having an alicyclic structure constituting the alicyclic polyolefin resin is preferably 55% by weight or more, more preferably 70% by weight or more, and particularly preferably 90% by weight or more. It is preferable from a viewpoint of transparency and heat resistance that the ratio of the repeating unit which has an alicyclic structure in alicyclic polyolefin resin exists in this range.

  Examples of the alicyclic structure-containing polymer resins include norbornene resins, monocyclic olefin resins, cyclic conjugated diene resins, vinyl alicyclic hydrocarbon resins, and hydrides thereof. . Among these, norbornene-based resins can be suitably used because of their good transparency and moldability.

Examples of the norbornene-based resin include a ring-opening polymer of a monomer having a norbornene structure, a ring-opening copolymer of a monomer having a norbornene structure and another monomer, or a hydride thereof; norbornene structure The addition polymer of the monomer which has this, the addition copolymer of the monomer which has a norbornene structure, and another monomer, those hydrides, etc. can be mentioned. Among these, a ring-opening (co) polymer hydride of a monomer having a norbornene structure is particularly suitable from the viewpoints of transparency, moldability, heat resistance, low hygroscopicity, dimensional stability, lightness, and the like. Can be used. Examples of the monomer having a norbornene structure include bicyclo [2.2.1] hept-2-ene (common name: norbornene) and tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene. (Common name: dicyclopentadiene), 7,8-benzotricyclo [4.3.0.1 ^2,5 ] dec-3-ene (common name: methanotetrahydrofluorene), tetracyclo [4.4.0. 1 ^2,5 . ^{17, 10} ] dodec-3-ene (common name: tetracyclododecene), and derivatives of these compounds (for example, those having a substituent in the ring). Here, examples of the substituent include an alkyl group, an alkylene group, and a polar group. Moreover, these substituents may be the same or different and a plurality may be bonded to the ring. Monomers having a norbornene structure can be used singly or in combination of two or more. Examples of the polar group include a hetero atom or an atomic group having a hetero atom. Examples of the hetero atom include an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, and a halogen atom. Specific examples of the polar group include a carboxyl group, a carbonyloxycarbonyl group, an epoxy group, a hydroxyl group, an oxy group, an ester group, a silanol group, a silyl group, an amino group, a nitrile group, and a sulfone group. In order to obtain a film having a low saturated water absorption rate, it is preferable that the amount of polar groups is small, and it is more preferable that there is no polar group.

  Other monomers capable of ring-opening copolymerization with monomers having a norbornene structure include monocyclic olefins such as cyclohexene, cycloheptene, and cyclooctene and derivatives thereof; cyclic conjugated dienes such as cyclohexadiene and cycloheptadiene; Derivatives thereof; and the like. A ring-opening polymer of a monomer having a norbornene structure and a ring-opening copolymer of a monomer having a norbornene structure and another monomer copolymerizable with the monomer have a known ring-opening polymerization catalyst. It can be obtained by (co) polymerization in the presence.

  Examples of other monomers that can be addition copolymerized with a monomer having a norbornene structure include α-olefins having 2 to 20 carbon atoms such as ethylene, propylene, and 1-butene, and derivatives thereof; cyclobutene, cyclopentene, And cycloolefins such as cyclohexene and derivatives thereof; non-conjugated dienes such as 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, and the like. These monomers can be used alone or in combination of two or more. Among these, α-olefin is preferable and ethylene is more preferable. An addition polymer of a monomer having a norbornene structure and an addition copolymer of a monomer having a norbornene structure with another monomer copolymerizable with a monomer having a norbornene structure are prepared in the presence of a known addition polymerization catalyst. It can be obtained by polymerization.

Hydrogenated product of ring-opening polymer of monomer having norbornene structure, hydrogenated product of ring-opening copolymer of monomer having norbornene structure and other monomer capable of ring-opening copolymerization, norbornene structure The hydride of an addition polymer of a monomer having a monomer, and the hydride of an addition copolymer of a monomer having a norbornene structure and another monomer capable of addition copolymerization with these ring-opening (copolymerization) ) A known hydrogenation catalyst containing a transition metal such as nickel or palladium is added to a polymer or addition (co) polymer solution, and brought into contact with hydrogen, so that the carbon-carbon unsaturated bond is preferably 90% or more. It can be obtained by hydrogenation. Among norbornene-based resins, as repeating units, X: bicyclo [3.3.0] octane-2,4-diyl-ethylene structure and Y: tricyclo [4.3.0.1 ^2,5 ] decane-7 , 9-diyl-ethylene structure, the content of these repeating units is 90% by weight or more based on the entire repeating units of the norbornene-based resin, and the content ratio of X and the content ratio of Y Is preferably 100: 0 to 40:60 by weight ratio of X: Y. By using such a resin, it is possible to obtain an optical film that has no dimensional change in the long term and is excellent in stability of optical characteristics.

  Specific examples of the alicyclic structure-containing polymer resin include ZEONOR (manufactured by ZEON Corporation), ARTON (manufactured by JSR Corporation), APPEL (manufactured by Mitsui Chemicals), TOPAS (manufactured by Topas Advanced Polymers), and the like. Can be mentioned. In addition, the alicyclic structure-containing polymer resin is excellent in surface smoothness, and by using a film made of the alicyclic structure-containing polymer resin having such a high surface smoothness as a film substrate, the organic layer is formed. It is no longer necessary to form and planarize, and while maintaining a low outgas emission level, a high gas barrier can be obtained simply by forming a gas barrier layer such as silicon oxide or aluminum oxide directly on the film substrate. Sex can be obtained.

  Examples of other preferable film base materials include PEN (polyethylene naphthalate) as a polyester-based material.

  In the present invention, the film substrate can be transparent to such an extent that it has a light transmittance suitable for use in a laminate for a surface light source device. In the present invention, each layer constituting the laminate for a surface light source device can have a light transmittance suitable for use in an optical member, and the entire laminate for a surface light source device can be 80% or more. It can have light transmittance.

  The film base material may be a base material obtained by forming the above-mentioned material into a film shape by an arbitrary forming method such as melt extrusion molding, and may further be a base material subjected to stretching treatment as necessary. The film substrate may also be a laminated film prepared by laminating and laminating a plurality of films, or a multilayer film having a plurality of layers of different materials by multilayer melt extrusion molding. . In the case of such a laminated film or multilayer film, it is preferable to include at least one layer of an alicyclic structure-containing polymer resin.

  If the thickness of a film base material consists of resin, for example, it is preferable that it is 20-300 micrometers. By setting it to 20 μm or more, it is preferable because sufficient strength can be obtained. Moreover, by setting it as 300 micrometers or less, the expansion | swelling by water absorption can be reduced and it is preferable.

(Gas barrier layer)
In the present invention, the gas barrier layer is a layer having an ability to barrier a component such as water vapor that exists in the outside air and can degrade the light emitting layer.
The upper limit of the water vapor permeability of the gas barrier layer is preferably 1.0 g / m ² · day or less, and more preferably 0.2 g / m ² · day or less. On the other hand, the lower limit of the water vapor transmission rate is most preferably 0 g / m ² · day, but even a value higher than that can function preferably within the above upper limit. When the laminated body for surface light source devices of this invention has a 1st gas barrier layer and a 2nd gas barrier layer, it is preferable that each gas barrier layer has said water vapor permeability.

Further, the surface light source device for laminate overall water vapor permeability of the present invention may be a ^{1 × 10 -6 ~1 × 10 -2} g / m 2 · day. Such a water vapor transmission rate of the entire laminate can be achieved by appropriately selecting materials and thicknesses of the first gas barrier layer, the second gas barrier layer, and other layers.

  The first gas barrier layer, which is an essential component in the present invention, is provided between the concavo-convex structure layer and the film substrate. The first gas barrier layer may be provided in direct contact with the film base material, or may be provided through any other layer. However, it is efficient that the first gas barrier layer is provided in direct contact with the film base material. For the protection of a typical film substrate.

  The second gas barrier layer, which is an optional component in the present invention, is provided between the film substrate and the transparent electrode layer. The second gas barrier layer may be provided in direct contact with the film base material or may be provided through any other layer, but it is efficient that the second gas barrier layer is provided in direct contact with the film base material. For the protection of a typical film substrate.

  The material of the gas barrier layer is not particularly limited, but preferred materials include silicon oxide, aluminum oxide, DLC (diamond-like carbon), and a mixture of two or more thereof. In terms of transparency, an oxide of silicon is particularly preferred, while in terms of affinity with a film substrate (especially when a film made of an alicyclic structure-containing polymer resin is used as the film substrate), DLC is Particularly preferred.

  Examples of the silicon oxide include SiOx (x is preferably 1.4 to 2.0), SiOxNy, and the like. Examples of the oxide of aluminum include AlOx and AlOxNy. From the viewpoint of gas barrier properties, SiOxNy or aluminum oxide can be used as a more preferable material.

  The thickness of the gas barrier layer is preferably 3 to 500 nm, and more preferably 10 to 100 nm.

  The method for forming the gas barrier layer is not particularly limited, but it is preferably formed on the film substrate by a film forming method such as vapor deposition, sputtering, or arc discharge plasma vapor deposition. When arc discharge plasma is used, evaporated particles having appropriate energy are generated, and a high-density film can be formed. When a gas barrier layer containing a plurality of types of components is formed, these can be deposited or sputtered simultaneously. Alternatively, a layer in which a plurality of layers are stacked may be provided as each of the first and second gas barrier layers.

  In the present invention, in addition to protecting the light emitting layer, the gas barrier layer protects the film base material, prevents the film base material from expanding by absorbing water vapor from outside air, and thus prevents deformation of the device. An effect can also be expressed. In addition, in forming the transparent electrode layer, it is possible to prevent the outgas from being released from the film substrate under the conditions of the process of forming the transparent electrode layer such as vapor deposition and sputtering. The formation conditions can be freely selected. As a result, the resistance value of the transparent electrode layer can be reduced, or the transparent electrode layer can be easily produced. These effects can be manifested particularly well when the second gas barrier layer is provided in addition to the first gas barrier layer. In the case of having the second gas barrier layer in addition to the first gas barrier layer, even if each layer is a thin layer, the entire laminate for a surface light source device can exhibit high sealing performance. By thinning each layer, it is possible to reduce problems such as cracks caused by mechanical loads such as bending.

  Further, the presence of the first gas barrier layer improves the adhesion between the concavo-convex structure layer and the film substrate (particularly when a film made of an alicyclic structure-containing polymer resin is used as the film substrate). The effect is also produced.

(Uneven structure layer)
In the present invention, the concavo-convex structure layer is provided on the film substrate via the first gas barrier layer.
The concavo-convex structure layer may be provided in direct contact with the first gas barrier layer, or may be provided through any other layer, but may be provided in direct contact with the first gas barrier layer. From the viewpoints of adhesion between the film substrate and the uneven structure layer, high light extraction efficiency, and the like. When the film substrate contains at least one layer of an alicyclic structure-containing polymer resin and the first gas barrier layer side is an alicyclic structure-containing polymer resin, when there is no first gas barrier layer It is further preferable from the viewpoint of realizing high adhesion as compared with the above.

  In the present invention, since the concavo-convex structure layer is provided via the first gas barrier layer, adhesion of the concavo-convex structure layer is improved, and in addition, the concavo-convex structure layer protects the first gas barrier layer. The mechanical strength of the laminate surface is improved.

  The material of the concavo-convex structure layer can be a light diffusing resin composition. Specifically, it can be set as the composition containing various resin and a diffuser. Examples of such resins include thermoplastic resins, thermosetting resins, and energy beam curable resins such as ultraviolet curable resins and electron beam curable resins. Among these, thermoplastic resins are preferable because they are easily deformable by heat, and ultraviolet curable resins are highly curable and efficient, and thus can efficiently form a light diffusion layer layer having a concavo-convex structure. Examples of the thermoplastic resin include a polyester resin, a polyacrylate resin, and an alicyclic structure-containing polymer resin. Examples of the ultraviolet curable resin include epoxy resins, acrylic resins, urethane resins, ene / thiol resins, and isocyanate resins. As these resins, those having a plurality of polymerizable functional groups can be preferably used.

  As the material for the concavo-convex structure layer, a material having high hardness at the time of curing is preferable from the viewpoint of easily forming the concavo-convex structure and easily obtaining scratch resistance of the concavo-convex structure. Specifically, when a layer having a film thickness of 7 μm is formed on a substrate without a concavo-convex structure, a material having a pencil hardness of HB or higher is preferable, a material of H or higher is more preferable, and 2H The material which becomes above is more preferable.

  Examples of the diffuser that can be contained in the concavo-convex structure layer include various particles. The particles may be transparent or opaque. As the material for the particles, metals, metal compounds, resins, and the like can be used. Examples of the metal compound include metal oxides and nitrides. Specific examples of metals and metal compounds include metals having high reflectivity such as silver and aluminum, and metal compounds such as silicon oxide, aluminum oxide, zirconium oxide, silicon nitride, tin-doped indium oxide, and titanium oxide. Can do. On the other hand, examples of the resin include methacrylic resin, polyurethane resin, and silicone resin.

The shape of the particles can be a spherical shape, a cylindrical shape, a cubic shape, a rectangular parallelepiped shape, a pyramid shape, a conical shape, a star shape, or the like.
The particle size of the particles is preferably 0.1 μm or more and 10 μm or less, more preferably 5 μm or less. Here, the particle diameter is a 50% particle diameter in an integrated distribution obtained by integrating the volume-based particle amount with the particle diameter as the horizontal axis. The larger the particle size, the larger the content ratio of particles necessary for obtaining the desired effect, and the smaller the particle size, the smaller the content. Therefore, as the particle size is smaller, desired effects such as a reduction in change in color depending on the observation angle and an improvement in light extraction efficiency can be obtained with fewer particles. When the particle shape is other than spherical, the diameter of the sphere having the same volume is used as the particle size.

  When the particles are transparent particles and the particles are contained in the transparent resin, the difference between the refractive index of the particles and the refractive index of the transparent resin is preferably 0.05 to 0.5, It is more preferable that it is 0.07-0.5. Here, either the particle or the refractive index of the transparent resin may be larger. If the refractive index of the particles and the transparent resin is too close, the diffusion effect cannot be obtained and the color unevenness is not suppressed. Conversely, if the difference is too large, the diffusion increases and the color unevenness is suppressed, but the light extraction effect is reduced. It will be.

  When the concavo-convex structure layer includes a resin and a diffuser, the blending ratio of the resin and the diffuser is preferably 3 to 50% by weight.

  In the laminate for a surface light source device of the present invention, the lower limit of the thickness of the concavo-convex structure layer is preferably 1 μm or more, more preferably 5 μm or more, and even more preferably 10 μm or more. The upper limit is preferably 50 μm or less, more preferably 25 μm or less, and even more preferably 15 μm or less. In particular, when the thickness is not more than the above upper limit, deformation of the laminate for a surface light source device due to curing shrinkage can be prevented, and a laminate for a surface light source device having a good shape can be obtained.

  The uneven structure layer has an uneven structure on its surface. Here, the “surface” of the concavo-convex structure layer is usually the surface of the concavo-convex structure layer opposite to the surface on the film substrate side. As the concavo-convex structure, a concavo-convex structure including a plurality of concave portions including an inclined surface and a flat portion positioned around the concave portion can be preferably exemplified. Here, the “slope” is a surface that forms an angle that is not parallel to the surface direction of the film substrate. On the other hand, the surface on the flat part can be a surface parallel to the surface direction of the film substrate.

  As an example of the concavo-convex structure, the concavo-convex structure on the top surface of the concavo-convex structure layer 111 of the multilayer body 100 for the surface light source device shown in FIGS. 1 and 2 will be described in more detail with reference to FIGS. FIG. 4 is a partial top view schematically showing an enlarged structure of the surface 10U of the surface light source device laminate 100 defined by the surface structure of the concavo-convex structure layer 111. As shown in FIG. FIG. 5 is a partial cross-sectional view showing a cross section of the concavo-convex structure layer 111 taken along a vertical plane passing through the line 10a of FIG.

  Each of the plurality of recesses 113 is a depression having a regular quadrangular pyramid shape. Therefore, the slopes 11A to 11D of the recess 113 have the same shape, and the bases 11E to 11H form a square. The line 10a is a line that passes over all the vertices 11P of the recesses 113 in a row, and is a line parallel to the bottom sides 11E and 11G of the recesses 113.

  The recess 113 is continuously arranged in two orthogonal arrangement directions at a constant interval. One of the two arrangement directions X is parallel to the bases 11E and 11G. In this direction X, the plurality of recesses 113 are aligned at a constant interval 11J. The other direction Y of the two arrangement directions is parallel to 11F and 11H. In this direction Y, the plurality of recesses 113 are aligned at a constant interval 11K.

  The angles formed by the inclined surfaces 11A to 11D constituting each of the recesses 113 with the flat portion 114 (for the inclined surfaces 11B and 11D, the angles 11L and 11M shown in FIG. 5 respectively) are set to, for example, 60 °. The apex angle of the regular quadrangular pyramid that is formed, that is, the angle formed by the opposing inclined surfaces at the apex 11P (the angle 11N shown in FIG. 5 for the angles formed by the inclined surfaces 11B and 11D) is also 60 °.

  As described above, the laminate for a surface light source device has a configuration including a plurality of recesses and a flat portion positioned around each recess on the surface of the concavo-convex structure layer corresponding to the device output surface of the surface light source device. In addition, the light extraction efficiency can be increased, the change in color depending on the observation angle can be reduced, and the occurrence of chipping of the concavo-convex structure due to the external impact can be prevented, thereby improving the mechanical strength of the light exit surface of the device. be able to. Furthermore, when the laminate for a surface light source device has light diffusibility, a change in color depending on the observation angle can be further reduced.

  Since the laminate for a surface light source device of the present invention has the above-described concavo-convex structure, displacement of at least one of the x-coordinate and y-coordinate of the chromaticity coordinates in all hemispherical directions in the light emitted from the concavo-convex structure layer side. Can be further reduced as compared with the case where the above configuration is not adopted. For this reason, in the surface light source device of this invention provided with the laminated body for surface light source devices of this invention, the change of the color by an observation angle can further be suppressed. As a method of measuring the displacement of chromaticity in all hemispherical directions, for example, the spectral radiance on the normal direction of the device light exit surface (that is, the direction perpendicular to the device light exit surface macroscopically ignoring the concave portion). When a meter is installed and the normal direction is set to 0 °, a chromaticity coordinate can be calculated from the emission spectrum measured in each direction by providing a mechanism that can rotate the light exit surface of the device from -90 to 90 °. The displacement can be calculated.

  The ratio of the area occupied by the flat part to the sum of the area occupied by the flat part and the area occupied by the concave part when the concavo-convex structure is observed from the direction perpendicular to the laminate for the surface light source device (hereinafter referred to as “flat part ratio”) The light extraction efficiency of the surface light source device can be improved by adjusting appropriately. Specifically, by setting the flat portion ratio to 10 to 75%, good light extraction efficiency can be obtained, and the mechanical strength of the device light exit surface can be increased.

  In the case where the concavo-convex structure layer has a concavo-convex structure on its surface, for example, in addition to the pyramid shape described above, the concave portion has a conical shape, a partial spherical shape, a groove-like shape, and a combination thereof. Can have. The pyramid shape may be a quadrangular pyramid having a square bottom surface as exemplified by the recess 113, but is not limited thereto, and may be a pyramid shape such as a triangular pyramid, a pentagonal pyramid, a hexagonal pyramid, or a quadrangular pyramid having a non-square base. You can also.

  Furthermore, the cones and pyramids mentioned in this application include not only ordinary cones and pyramids with sharp points, but also rounded tips or flat chamfered shapes (frustum-shaped shapes, etc.). To do. For example, in the concave portion 113 shown in FIG. 5, the top portion 11 </ b> P of the quadrangular pyramid has a pointed shape, but this may have a rounded shape like the top portion 61 </ b> P of the concave portion 613 shown in FIG. 6. Moreover, like the recessed part 713 shown in FIG. 7, the flat part 71P can be provided in the top part of a pyramid, and it can also be set as the shape chamfered flatly.

  As shown in FIG. 6, when the top of the pyramid has a rounded shape, the height difference 61R between the top 61P and the top 61Q when the pyramid has a rounded and sharp shape is as follows: The pyramid can be 20% or less of the height 61S of the pyramid when the pyramid has a rounded and sharp shape. As shown in FIG. 7, when the top of the pyramid has a flat chamfered shape, the height of the flat portion 71P and the top 71Q when the top of the pyramid is not flat but sharp. The difference 71R can be 20% or less of the height 71S of the pyramid when the apex of the pyramid is not flat but sharp.

  The depth of the concave portion in the concavo-convex structure is not particularly limited, but the maximum centerline average roughness measured on the surface on which the concavo-convex structure is formed in various directions (various directions in a plane parallel to the light exit surface). The value (Ra (max)) can be in the range of 1 to 50 μm. When the concavo-convex structure is formed on the concavo-convex structure layer, a preferable depth of the concave portion can be determined relative to the thickness of the concavo-convex structure layer. For example, when a hard material that is advantageous for maintaining the durability of the concavo-convex structure layer is used as the material of the concavo-convex structure layer, the thickness of the concavo-convex structure layer is reduced to increase the flexibility of the laminate for the surface light source device. It becomes possible to increase the height and facilitate handling of the surface light source device laminate in the manufacturing process of the surface light source device. Specifically, the ratio of the thickness 16E of the uneven structure layer 111 to the depth 16D of the recess shown in FIG. 5 is preferably 1: 1 to 1: 3.

  In the present invention, the angle formed by the inclined surface of the recess and the light exit surface is preferably 40 to 70 °, and more preferably 45 to 60 °. For example, when the shape of the recess is a quadrangular pyramid shown in FIG. 5, the apex angle (corner 11 </ b> P in FIG. 5) is preferably 60 to 90 °. Further, from the viewpoint of enhancing light extraction efficiency while minimizing the change in color depending on the observation angle, it is preferable that the angle formed by the inclined surface and the surface of the film substrate is large, and specifically, for example, 55 ° or more. It is preferable that the angle is 60 ° or more. In this case, the upper limit of the angle can be about 70 ° in consideration of maintaining the durability of the uneven structure layer.

  When the shape of the recess is a rounded or flat chamfered pyramid shape, conical shape or groove shape at the top, the angle of the slope excluding the rounded portion or the chamfered portion, The angle of the slope. For example, in the example shown in FIGS. 6 and 7, the surfaces 613a, 613b, 713a, and 713b are slopes of a pyramid. By setting the angle of the slope to such an angle, the light extraction efficiency can be increased. The slopes of the concavo-convex structure need not all have the same angle, and slopes having different angles may coexist within the above range. The angle formed by the conical slope and the surface of the film substrate can be the angle formed by the generatrix of the cone and the surface of the film substrate.

  On the surface of the uneven structure layer, the plurality of recesses can be arranged in any manner. For example, a plurality of recesses can be arranged along two or more directions on the surface. More specifically, they can be arranged along two orthogonal directions like the recesses 113 shown in FIGS.

  In the case where the concave portions are arranged in two or more directions, a gap between adjacent concave portions is provided in one or more directions among them, and the flat portion can be constituted by the gap. For example, in the arrangement of the recesses 113 shown in FIG. 4, gaps of intervals 11J and 11K are provided in two orthogonal directions, and the flat part 114 is configured by the gaps. By adopting such a configuration, it is possible to achieve both good light extraction efficiency and mechanical strength of the laminate surface.

(Method for forming uneven structure layer)
The concavo-convex structure layer can be formed on the first gas barrier layer by preparing a resin composition (1) suitable for forming the concavo-convex structure layer, for example. As the resin composition (1) suitable for forming the concavo-convex structure layer, it is possible to use the above-listed resin that is the material of the concavo-convex structure layer and before curing, and a composition containing a diffusing agent. it can. Resin composition (1) can contain a solvent as needed. However, the resin composition (1) can be prepared without adding a solvent, and can be a composition that has few or no components that need to be volatilized in the forming step, so that the photopolymer method described later can be smoothly performed. It is preferable from a viewpoint of being able to perform.

  The resin composition (1) is applied onto the surface of the first gas barrier layer to obtain a coating film. If necessary, the solvent in the coating film is volatilized, and further, irradiation with energy rays or the like is performed as necessary. By performing the curing treatment, an uneven structure layer can be obtained.

  Formation of the concavo-convex structure of the concavo-convex structure layer can be performed by preparing a mold such as a mold having a desired shape and transferring the shape of the mold at an arbitrary stage after obtaining the coating film.

  More specifically, it is preferable to form a concavo-convex structure by a photopolymer method after obtaining the coating film and before performing a curing treatment. That is, it is preferable to apply a mold to the formed coating film and cure the coating film in that state to form a cured layer having an uneven structure. In this case, as the resin composition (1), it is preferable to use a composition that can be cured by energy rays such as ultraviolet rays. The resin composition (1) is applied onto the first gas barrier layer to obtain a coating film, and the back side of the coating surface (the film composition resin composition (1 ) Irradiation of energy rays such as ultraviolet rays from a light source located on the side opposite to the surface coated with), the resin composition (1) is cured, and then the mold is peeled off, thereby reversing the uneven structure of the mold. A concavo-convex structure layer having a concavo-convex structure can be obtained.

(Transparent electrode layer)
A transparent electrode layer is provided in the surface side opposite to the side in which a 1st gas barrier layer is provided among both surfaces of a film base material.
The transparent electrode layer may be provided in direct contact with the film substrate or may be provided via any other layer, but preferably via the second gas barrier layer described above. Provided.

  Although the material of a transparent electrode layer is not specifically limited, It is preferable to use a metal as a material and to set it as a metal thin film layer. As such a metal thin film layer, a thin film of a metal oxide such as ITO and a thin film such as a thin film containing a material selected from the group consisting of gold, silver, and a mixture thereof can be used. It is preferable to use a thin film containing a material selected from the group consisting of these and a mixture thereof from the viewpoint of reducing the sheet resistance value. Further, a sheet resistance value may be reduced by laminating a thin film of a metal oxide such as ITO and a thin film such as a thin film containing a material selected from the group consisting of gold, silver, and a mixture thereof. The metal thin film layer in the laminate used for the surface light source device having an organic EL element preferably has an absorptivity for light with a wavelength of 550 nm within 10%, more preferably within 5%, and a transmittance for light with a wavelength of 550 nm of 25. It is preferable that the film is a translucent reflective film of from% to 75%, particularly preferably from 50% to 75%. By setting the absorptivity or transmittance within this range, high light extraction efficiency can be realized. Although the transmittance may be measured directly by forming a metal thin film layer on the base film, the reflectance may be measured and converted from the relationship of transmittance + reflectivity + absorbance = 100%.

  When a thin film containing a material selected from the group consisting of gold, silver, and a mixture thereof is used as the transparent electrode layer, the purity of gold and / or silver in the thin film is not particularly limited, but is preferably 90% or more. can do.

  The method for forming the transparent electrode layer is not particularly limited, but it is preferably formed by a film forming method such as vapor deposition or sputtering. Sputtering is preferable from the viewpoint of imparting gas barrier performance to the transparent electrode layer. On the other hand, vapor deposition is preferred from the viewpoint of film formation speed. When forming a transparent electrode layer containing a plurality of kinds of components, these can be vapor-deposited or sputtered simultaneously. Alternatively, a plurality of layers may be provided as a transparent electrode layer. For example, as in the example shown in FIG. 3, a silver thin film layer 141 and an ITO layer 144 may be sequentially formed from the side closer to the film substrate to form a transparent electrode layer composed of a plurality of layers.

  The transparent electrode layer preferably has a sheet resistance value of 50Ω / □ or less, preferably 30Ω / □ or less, and more preferably 20Ω / □ or less. Although it is generally difficult to obtain a transparent electrode layer having such a low sheet resistance value, a second gas barrier layer using an alicyclic structure-containing polymer resin as a material for a film base is used as necessary. A transparent electrode layer having a low sheet resistance value can be obtained by providing and using a thin film containing a material selected from the group consisting of gold, silver, and a mixture thereof.

  In the laminate for a surface light source device of the present invention, the thickness of the transparent electrode layer can be 5 to 1000 nm.

<Surface light source device>
The surface light source device of the present invention includes the laminate for a surface light source device of the present invention and an organic EL element.
FIG. 8 is a perspective view schematically showing an example of the surface light source device of the present invention including the laminate 100 for the surface light source device of the present invention shown in FIGS. 1 and 2, and FIG. It is sectional drawing which shows the cross section which cut | disconnected the surface light source device 10 shown by the surface perpendicular to the surface direction of a film base material through line | wire 1a-1b in FIG.

  The surface light source device 10 is a device having a rectangular flat plate-like structure. The surface light source device laminate 100 of the present invention located on the device light-emitting surface side, and the transparent electrode layer 141 side of the surface light source device laminate 100. A light emitting layer 142 provided in contact with the surface 146, and a reflective electrode layer 143 provided in contact with the light emitting layer 142. The transparent electrode layer 141, the light emitting layer 142, and the reflective electrode layer 143 constitute the organic EL element 140. The surface light source device 10 further includes a sealing substrate 151 as an optional component on the surface 145 side of the organic EL element 140 opposite to the device light exit surface.

  Light from the light emitting layer 142 passes through the transparent electrode layer 141 or is reflected by the reflective electrode layer 143, passes through the light emitting layer 142 and the transparent electrode layer 141, and travels toward the device light exit surface 100 side. Most of the light emitted from the organic EL element 140 is transmitted through the second gas barrier layer 122, the film base 131, the first gas barrier layer 121, and the concavo-convex structure layer 111 in this order, and is emitted from the surface 10U. Therefore, the surface 10 </ b> U of the surface light source device laminate 100 is a device light exit surface of the surface light source device 10.

  As described above, the light from the light emitting layer 142 is transmitted through the surface light source device laminate 100 to emit light, thereby improving the light extraction efficiency by the uneven structure on the surface 10U of the surface light source device laminate 100. Can do. Further, when a layer such as the concavo-convex structure layer 111 has diffusibility, light is emitted in a state where light is further diffused thereby, and as a result, a change in color of the light-emitting surface due to an observation angle can be suppressed.

  In addition, since the first gas barrier layer and the second gas barrier layer prevent components such as water vapor that degrade the light emitting layer in the outside air from reaching the light emitting layer from the device light-emitting surface side, the device having a long lifetime It can be. In addition, since the concavo-convex structure layer is positioned on the device light exit surface, the mechanical strength of the device light exit surface is improved.

(Organic EL device)
As exemplified as the organic EL element 140, in the surface light source device of the present invention, a transparent electrode layer in the laminate for a surface light source device, an electrode layer facing the transparent electrode layer such as a reflective electrode layer, and the like. The organic EL element is composed of a light emitting layer that is provided between the electrode layers and emits light when voltage is applied from the electrodes.

  In the organic EL element, a layer such as an electrode or a light emitting layer constituting the element is formed on a substrate, a sealing member that covers those layers is further provided, and the layer such as the light emitting layer is sealed with the substrate and the sealing member. Generally, it is configured. Usually, the element that emits light from the substrate side here is called a bottom emission type, and the element that emits light from the sealing member side is called a top emission type. The surface light source device of the present invention may be any of these, but can usually be a bottom emission type using a film base as a substrate.

  In this invention, it does not specifically limit as a light emitting layer which comprises an organic EL element, A well-known thing can be selected suitably. The light-emitting material in the light-emitting layer is not limited to one type, and the light-emitting layer is not limited to one layer, and may be a single layer or a combination of a plurality of layers in order to suit the use as a light source. Thereby, light of white or a color close thereto can be emitted.

  The organic EL device may further include other layers such as a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, and a gas barrier layer in addition to the light emitting layer between the electrodes. The organic EL element can further include arbitrary components such as a wiring for energizing the electrode and a peripheral structure for sealing the light emitting layer.

  The electrode facing the transparent electrode layer in the laminate for the surface light source device of the organic EL element is not particularly limited, and a known one can be appropriately selected. Like the organic EL element 140 shown in FIG. 8 and FIG. 9, an organic EL element that emits light toward the light-emitting surface structure layer can be obtained by using the opposing electrode as a reflective electrode. Moreover, by making both electrodes into transparent electrodes and further having a reflecting member on the side opposite to the light-emitting surface structure layer, it is possible to achieve light output to the light-emitting surface structure layer side.

Although it does not specifically limit as a material which comprises an electrode and the layer provided among them, The following can be mentioned as a specific example.
ITO etc. can be mentioned as a material of a transparent electrode.
Examples of the material for the hole injection layer include a starburst aromatic diamine compound.
Examples of the material for the hole transport layer include triphenyldiamine derivatives.
Examples of the host material for the yellow light-emitting layer include triphenyldiamine derivatives, and examples of the dopant material for the yellow light-emitting layer include tetracene derivatives.
Examples of the material for the green light emitting layer include pyrazoline derivatives.
Examples of the host material for the blue light emitting layer include anthracene derivatives, and examples of the dopant material for the blue light emitting layer include perylene derivatives.
As a material for the red light emitting layer, a europium complex or the like can be used.
Examples of the material for the electron transport layer include an aluminum quinoline complex (Alq).
Examples of the cathode material include lithium fluoride and aluminum, which are sequentially stacked by vacuum film formation.

  By appropriately combining the above or other light-emitting layers, a light-emitting layer that generates a light emission color having a complementary color relationship, which is referred to as a stacked type or a tandem type, can be obtained. The combination of complementary colors can be yellow / blue, green / blue / red, or the like.

(Use)
The surface light source device of the present invention having the laminate for a surface light source device of the present invention can be used for applications such as lighting fixtures and backlight devices.
The luminaire includes the surface light source device of the present invention as a light source, and can further include arbitrary components such as a member for holding the light source and a circuit for supplying power. The backlight device includes the surface light source device of the present invention as a light source, and further includes a housing, a circuit for supplying electric power, a diffusion plate for making light emitted more uniform, a diffusion sheet, a prism sheet, and the like. The components can be included. The use of the backlight device can be used as a backlight of a display device such as a liquid crystal display device that displays an image by controlling pixels and a display device that displays a fixed image such as a signboard.

(Other)
The present invention is not limited to the above specific examples, and can be arbitrarily modified within the scope of the claims of the present application and equivalents thereof.
For example, the laminate for a surface light source device of the present invention may further include an arbitrary layer in addition to the concavo-convex structure layer, the gas barrier layer, the film base material, and the transparent electrode layer. Such an arbitrary layer is not only a layer located between the concavo-convex structure layer, the gas barrier layer, the film substrate, and the transparent electrode layer, but also a coating layer further provided on the concavo-convex structure on the surface of the concavo-convex structure layer, for example. The coating layer may define the concavo-convex structure of the device light exit surface of the surface light source device of the present invention.
Moreover, in the illustration of the above embodiment, the concave portions distributed over the entire surface of the concavo-convex structure layer are shown as those having only the same shape distributed, but the surface of the concavo-convex structure layer has different shapes. Concave portions may be mixed. For example, pyramid-shaped recesses of different sizes are mixed, pyramid-shaped recesses and cone-shaped recesses are mixed, or a combination of multiple pyramids and a simple pyramid shape are mixed. It may be.
Further, in the above specific example, the width of the flat portion constituting the concavo-convex structure and the interval between the adjacent flat portions are always constant, but the width of the flat portion is narrow and wide. Moreover, the location where the space | interval of a flat part is narrow and the wide location may be mixed. In such a manner, rainbow unevenness due to interference is suppressed by adopting an aspect in which one or more elements of the height, width, and interval of the flat portion are provided with a dimensional difference exceeding the difference that causes interference of emitted light. can do.
Further, even if the reflective electrode layer in the above specific example is replaced with a transparent electrode layer and a reflective layer, an apparatus having the same effect as the reflective electrode layer can be configured.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

  In the examples and comparative examples, the water vapor transmission rate was measured under the conditions of 40 ° C. and 90% RH using PERCONTORON manufactured by MOCON.

<Example 1>
(1-1. Resin composition (1))
Resin composition (1) which adds 2 μm diameter particles (silicone resin) to UV curable resin (refractive index of 1.54) mainly composed of urethane acrylate and stirs to disperse the particles. ) Was prepared. The content ratio of the particles was 10% by weight in the total amount of the resin composition (1).

(1-2. Formation of gas barrier layer and transparent electrode layer)
On one side of a roll-shaped film substrate (trade name “ZEONOR FILM”, manufactured by Nippon Zeon Co., Ltd., alicyclic structure-containing polymer resin film, thickness 180 μm), vacuum formation using arc discharge plasma is performed. A 50 nm SiOxNy film was formed as a second gas barrier layer using a film apparatus. Next, an ITO layer as a transparent electrode layer was further formed on the second gas barrier layer of this film to a thickness of 1000 mm by sputtering. Next, a 50 nm SiOx film is formed on the other surface (the surface of the film base that does not have the second gas barrier layer and the transparent electrode layer) by a vacuum film forming apparatus using arc discharge plasma. As a gas barrier layer, a multilayer film having a layer configuration of (first gas barrier layer)-(film substrate)-(second gas barrier layer)-(transparent electrode layer) was obtained.

The water vapor permeability of the first gas barrier layer and the second gas barrier layer was measured and found to be 0.14 g / m ² · day and 0.01 g / m ² · day, respectively. In the measurement, each film was separately formed on a film substrate (Zeonor film) and measured.

(1-3. Formation of concavo-convex structure layer, production of laminate for surface light source device)
On the surface of the multilayer film obtained in (1-2) on the first gas barrier layer side, the resin composition (1) obtained in (1-1) is applied to form a paint film, and the paint film A metal mold was pressed on top. In this state, the transparent electrode layer, the second gas barrier layer, the film substrate, and the first gas barrier layer are transmitted, and the coating film of the resin composition (1) is irradiated with ultraviolet rays at 1.5 J / cm ² . The coating film is cured to form an uneven structure layer, and the layer structure of (uneven structure layer)-(first gas barrier layer)-(film substrate)-(second gas barrier layer)-(transparent electrode layer) is formed. A laminate 1 for a surface light source device was obtained. As the metal mold, a metal mold having a shape in which a regular quadrangular pyramid having an apex angle of 60 ° and a base of 25 μm is arranged at a pitch of 30 μm (that is, a flat portion of 5 μm exists between adjacent quadrangular pyramids) is used. It was.

In the obtained laminate 1 for a surface light source device, on the surface of the concavo-convex structure layer, a shape in which the shape of the surface of the metal mold is transferred, that is, a recess 113 and a flat portion 114 schematically shown in FIG. The concavo-convex structure layer had good scratch resistance. The water vapor transmission rate of the laminate 1 for a surface light source device was 0.005 g / m ² · day or less. Furthermore, the sheet resistance value of the transparent electrode layer was 48Ω / □.

(1-4. Surface light source device)
On the surface on the transparent electrode layer side of the laminate 1 for a surface light source device obtained in (1-3), a hole transport layer 10 nm, a yellow light emitting layer 20 nm, a blue light emitting layer 15 nm, an electron transport layer 15 nm, an electron injection layer 1 nm, and A reflective electrode layer of 100 nm was formed in this order. The hole transport layer to the electron transport layer were all made of an organic material. The yellow light emitting layer and the blue light emitting layer have different emission spectra.

The materials forming each layer from the hole transport layer to the reflective electrode layer are as follows:
Hole transport layer; 4,4′-bis [N- (naphthyl) -N-phenylamino] biphenyl (α-NPD)
・ Yellow light emitting layer: 1.5% by weight of rubrene added α-NPD
Blue light-emitting layer; iridium complex added at 10% by weight 4,4′-dicarbazolyl-1,1′-biphenyl (CBP)
-Electron transport layer; phenanthroline derivative (BCP)
-Electron injection layer; lithium fluoride (LiF)
-Reflective electrode layer: Al

For the formation from the hole injection layer to the reflective electrode layer, a film substrate on which a transparent electrode layer has already been formed is installed in a vacuum vapor deposition apparatus, and the materials from the hole transport layer to the reflective electrode layer are sequentially deposited by resistance heating. It was done by letting. The system internal pressure was 5 × 10 ⁻³ Pa and the evaporation rate was 0.1 to 0.2 nm / s.

  Furthermore, wiring for energization is attached to the electrode layer, and further, the hole transport layer to the reflective electrode layer are sealed with a sealing member, (uneven structure layer)-(first gas barrier layer)-(film base material) A surface light source device having a layer configuration of-(second gas barrier layer)-(organic EL element including a transparent electrode layer)-(sealing member) was obtained. The obtained surface light source device had a rectangular light exit surface capable of emitting white light from the concavo-convex structure layer of the laminate 1 for surface light source device. When the surface light source device thus obtained was energized and driven, good white light emission was obtained.

<Example 2>
Instead of providing the ITO layer as the transparent electrode layer, the laminate 2 for the surface light source device was performed in the same manner as in Example 1 except that the deposition time was adjusted so that the reflectance was 35% and the silver layer was provided. Further, a surface light source device was manufactured. The sheet resistance value of the silver transparent electrode layer of the obtained laminate 2 for a surface light source device was 24Ω / □. The water vapor transmission rate of the laminate 2 for a surface light source device was 0.005 g / m ² · day or less. When the surface light source device thus obtained was energized and driven, good white light emission was obtained.

<Comparative Example 1>
A surface light source having a layer structure of (uneven structure layer)-(film substrate)-(transparent electrode layer) in the same manner as in Example 1 except that the first gas barrier layer and the second gas barrier layer were not provided. The laminated body 3 for apparatuses was obtained. The obtained laminate 3 for a surface light source device had a water vapor transmission rate of 0.6 g / m ² · day. Moreover, the adhesiveness of an uneven | corrugated structure layer and a film base material was bad, and the peeling part was seen.

10: surface light source device 10U: surface of laminate for surface light source device 11A to 11D: slope 11E to 11H: bottom of recess 100, 200: laminate for surface light source device 111: concavo-convex structure layer 113: recess 114: flat portion 121: first 1 gas barrier layer 122: second gas barrier layer 131: film base material 140: organic EL element 141: transparent electrode layer 142: light emitting layer 143: reflective electrode layer 144: transparent electrode layer 151: sealing substrate

Claims (6)

A layered body for a surface light source device for constituting a light-emitting surface side layer of a surface light source device including an organic electroluminescence element,
A concavo-convex structure layer having a concavo-convex structure on the surface, a first gas barrier layer, a film substrate, and a transparent electrode layer are provided in this order,
The first gas barrier layer is provided in direct contact with the film substrate, the concavo-convex structure layer is provided directly on the first gas barrier layer,
The concave-convex structure layer is made of ultraviolet curing resin, the film substrate alicyclic structure-containing polymer or Ranaru, surface light source device for laminate. The laminate for a surface light source device according to claim 1, further comprising a second gas barrier layer between the film base and the transparent electrode layer. The relief structure, a plurality of recesses comprising an inclined surface, and a flat portion located around each recess, a surface light source device for laminate according to claim 1 or 2. The laminate for a surface light source device according to any one of claims 1 to 3 , wherein the transparent electrode layer is formed of a metal thin film layer, and the sheet resistance value of the transparent electrode layer is 50 Ω / □ or less. The laminate for a surface light source device according to claim 4 , wherein the metal thin film layer includes a material selected from the group consisting of gold, silver, and a mixture thereof. A surface light source device provided with the laminated body for surface light source devices of any one of Claims 1-5 , a light emitting layer, and a reflective electrode layer in this order.

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