JP5867154B2 - Lighting device - Google Patents

Description

  The present invention relates to an illuminating device in which an organic electroluminescence element and a light extraction member are provided on the light emission surface side of the organic electroluminescence element.

The light emitter of the organic electroluminescence element (hereinafter sometimes referred to as “organic EL element”) can have a planar shape, and the light color can be white or a color close thereto. Since it is possible, it is used as a light source of an illuminating device. As an organic EL element used for illumination, a white organic EL element is produced. Many of such white elements are laminated layers or light-emitting layers that generate a luminescent color having a complementary color relationship, which are referred to as a laminated type or a tandem type. These light emitting layer laminates are mainly yellow / blue or green / blue / red laminates.

However, the currently known white organic EL elements are low in efficiency for use in the above-described illumination applications. Therefore, in order to use the organic EL element for these applications, it is necessary to improve the light extraction efficiency. As a method for improving the light extraction efficiency of the organic EL element, it is known to provide various structures on the light extraction substrate. For example, it has been proposed to provide a prism containing a fluorescent compound on the light exit surface (Patent Document 1), and to provide a microlens array (Patent Document 2). With these structures, good light collection can be achieved and efficiency is improved.

On the other hand, the lighting device may be required to be flame retardant because it is used indoors such as in an office or a house, and has been devised such as adding a flame retardant to a member used in the lighting device. (Patent Document 3). However, it is conceivable that the efficiency of the organic EL element is reduced by blending the flame retardant, and further problems such as color may occur.

JP 2002-237381 A JP 2003-59641 A JP 2010-177077 A

  Accordingly, an object of the present invention is to provide an organic EL lighting device that has sufficient flame retardancy, has high light extraction efficiency, and has no problems such as color.

As a result of the study by the present inventor to solve the above-described problem, an organic EL element and a light extraction member provided on the light emission surface side of the organic EL element are provided, and the light extraction member layer includes particles. The present invention has been completed by finding that the above-mentioned problems can be solved by using an illuminating device comprising flame retardant particles having a diameter of 0.4 μm or less.
That is, according to the present invention, the following is provided.

[1] An illuminating device in which an organic electroluminescence element and a light extraction member layer are provided on the light emission surface side of the organic electroluminescence element,
The light extraction member layer includes flame retardant particles having an average particle size of 0.4 μm or less.
[2] The lighting device according to [1], wherein the flame retardant particles are phosphorus-based flame retardant particles or inorganic hydroxide particles.
[3] The light extraction member layer includes at least two or more layers, and includes a flame retardant particle having a particle diameter of 0.4 μm or less in the outermost surface layer of the light emission surface. Lighting device.

[4] The illumination device according to [3], wherein the outermost surface layer of the light output surface of the light extraction member layer is a structural layer.
[5] The illumination device according to [3] or [4], wherein the layer on the outermost surface side of the light output surface and / or the layer on the organic electroluminescence side of the light extraction member layer is a diffusion layer.

  The organic EL lighting device of the present invention is excellent in flame retardancy and light extraction efficiency.

FIG. 1 is a perspective view schematically showing the organic EL lighting device according to the first embodiment of the present invention. FIG. 2 is a diagram for explaining the organic EL lighting device according to the first embodiment of the present invention, in which the organic EL lighting device shown in FIG. 1 is cut along a plane perpendicular to the light exit surface through line 1a-1b. FIG. 6 is a cross-sectional view schematically showing the cross section taken. FIG. 3 is a partial plan view schematically showing an enlarged view of a part of the light exit surface of the organic EL lighting device according to the first embodiment of the present invention as viewed from the thickness direction of the organic EL lighting device. FIG. 4 is a partial cross-sectional view schematically showing a cross section obtained by cutting the concavo-convex structure layer according to the first embodiment of the present invention along a plane that passes through the line 3a of FIG. 3 and is perpendicular to the light exit surface. FIG. 5 is a perspective view schematically showing an organic EL lighting device according to the second embodiment of the present invention. FIG. 6 is a diagram for explaining the organic EL lighting device according to the second embodiment of the present invention. The concavo-convex structure layer of the organic EL lighting device shown in FIG. 5 passes through lines 5a-5b and is perpendicular to the light exit surface. It is sectional drawing which shows typically the cross section cut | disconnected by the plane. FIG. 7 is a perspective view schematically showing an organic EL lighting device according to the third embodiment of the present invention. FIG. 8 is a cross-sectional view schematically showing another example of the organic EL lighting device according to the third embodiment of the present invention.

The lighting device of the present invention is provided with an organic EL element and a light extraction member layer on the light output surface side of the organic EL element, and the light extraction member layer includes flame retardant particles having a particle diameter of 0.4 μm or less. Hereinafter, the present invention will be described in detail with reference to embodiments and examples, but the present invention is not limited to the embodiments and examples described below, and the gist of the present invention and its equivalent scope. Any change can be made without departing from the scope of the invention. The present invention will be described according to an embodiment.

[First embodiment]
1 and 2 are views for explaining the organic EL lighting device according to the first embodiment of the present invention. FIG. 1 is a perspective view schematically showing the organic EL lighting device, and FIG. It is sectional drawing which shows typically the cross section which cut | disconnected the organic electroluminescent illuminating device shown in 1 in the surface perpendicular | vertical with respect to the light emission surface through line 1a-1b.

  As shown in FIG. 1, the organic EL lighting device 10 according to the first embodiment of the present invention is a device having a rectangular flat structure and includes an organic EL element 140. The organic EL element 140 includes at least a first electrode layer 141, a light emitting layer 142, and a second electrode layer 143 in the order described above, and can emit light from at least one of the surfaces 144 and 145. In the present embodiment, the first electrode layer 141 is a transparent electrode, and the second electrode layer 143 is a reflective electrode. For this reason, the light from the light emitting layer 142 is transmitted through the first electrode layer 141, or is reflected by the second electrode layer 143 and then transmitted through the light emitting layer 142 and the first electrode layer 141. Light can be emitted from the surface 144. Therefore, in the following description, the surface 144 is referred to as a “light emitting surface”.

  The light extraction member layer 100 is provided on the light emitting surface 144 side of the organic EL element 140. In the present embodiment, the light extraction member layer 100 is directly provided so as to be in contact with the light emitting surface 144.

  Furthermore, the organic EL lighting device 10 of the present embodiment may include components other than the above-described members. In the present embodiment, it is assumed that the sealing substrate 151 is provided on the lower surface 145 of the organic EL element 140 in the drawing. Although illustration is omitted, an arbitrary substance such as a filler or an adhesive may exist between the surface 145 and the sealing substrate 151, or a gap may exist. As long as there is no inconvenience such as greatly impairing the durability of the light emitting layer 142, air or other gas may be present in the space, or the space may be evacuated.

  Therefore, the organic EL lighting device 10 includes the sealing substrate 151, the organic EL element 140, and the light extraction member layer 100 in this order, and can emit light from the surface 10U on the opposite side of the light extraction member layer 100 from the organic EL element 140. It is like that. The surface 10U is located on the outermost side of the organic EL lighting device 10, and light is emitted from the surface 10U to the outside of the organic EL lighting device 10. Therefore, the surface 10U is referred to as a “light emitting surface”.

[1-1. Organic EL device]
For example, as exemplified by the organic EL element 140, the organic EL element usually includes two or more electrode layers and a light emitting layer that is provided between these electrode layers and emits light when a voltage is applied from the electrodes. Prepare.

  In the organic EL element, layers such as an electrode and a light emitting layer constituting the organic EL element are formed on a substrate, and a sealing member for covering those layers is provided, and the layer such as the light emitting layer is sealed with the substrate and the sealing member. It is common to have a stopped configuration. Usually, the organic EL element that emits light from the substrate side here is called a bottom emission type, and the organic EL element that emits light from the sealing member side is called a top emission type. Any of these may be sufficient as the organic EL element 140 provided in the organic EL lighting device 10. In the case of the bottom emission type, normally, a combination including the substrate and an optional layer as needed constitutes the light extraction member. On the other hand, in the case of the top emission type, normally, a combination including a structure on the light output surface side such as a sealing member and an optional layer as necessary constitutes the light extraction member layer.

  As a light emitting layer, it does not specifically limit but a known thing can be selected suitably. The light emitting material in the light emitting layer is not limited to one type, and two or more types may be used in combination at any ratio. In addition, the light emitting layer is not limited to one layer, and may be a single layer alone or a combination of a plurality of layers in order to be suitable for use as a light source. Thereby, light of white or a color close thereto can be emitted.

  The electrode of the organic EL element is not particularly limited, and a known one can be appropriately selected. As in the organic EL element 140 according to the first embodiment, the electrode 141 on the light extraction member layer 100 side is a transparent electrode, and the opposite electrode 143 is a reflection electrode, thereby emitting light toward the light extraction member 100 side. An organic EL element that emits light from the surface 144 can be obtained. Further, both electrodes 141 and 143 are transparent electrodes, and further, a light reflecting member or a scattering member (for example, a white scattering member disposed via an air layer) is provided on the side opposite to the light extraction member 100, thereby extracting light. Light emission to the member layer 100 side can also be achieved.

  In addition to the light emitting layer 142, the organic EL element 140 further includes other layers (not shown) such as a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer between the electrode 141 and the electrode 143. May further be included. Further, the organic EL element 140 may further include arbitrary components such as a wiring for energizing the electrodes 141 and 143 and a peripheral structure for sealing the light emitting layer 142.

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.
Examples of the material for the transparent electrode include ITO (indium tin oxide). 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 a triphenyldiamine derivative. 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.
Examples of the material for the red light emitting layer include a europium complex.
Examples of the material for the electron transport layer include aluminum quinoline complex (Alq).
Examples of the material for the reflective electrode include lithium fluoride and aluminum, which are sequentially laminated 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.

[1-2. (Light extraction member layer)
The light extraction member layer 100 is a layer provided on the light emitting surface 144 of the organic EL element 140, and is a layer that improves the light extraction efficiency of the organic EL element and has a function of disturbing the reflection and refraction of the emitted light. Including. Specific examples of the layer that disturbs reflection / refraction of emitted light include a structural layer and a diffusion layer. The light exit surface 10U is the surface of the light extraction member 100 opposite to the organic EL element 140. The light exit surface 10U is a surface exposed on the outermost surface of the organic EL illumination device 10, and is a light exit surface as the organic EL illumination device 10, that is, a light exit surface when light is emitted from the organic EL illumination device 10 to the outside of the device. is there.

When viewed macroscopically, the light exit surface 10 </ b> U is a surface parallel to the light emitting surface 144 of the organic EL element 140 and parallel to the main surface of the organic EL lighting device 10. However, when the light exit surface 10U is microscopically viewed, the light exit surface 10U has a concavo-convex structure, which will be described later. Therefore, in the following description, being parallel or perpendicular to the light exit surface means that it is parallel or perpendicular to the light exit surface viewed macroscopically ignoring the recesses or projections unless otherwise specified. Say. Further, the organic EL lighting device 10 will be described in a state where the light exit surface 10U is placed so as to be parallel and upward with respect to the horizontal direction unless otherwise specified.
Further, the fact that the component is “parallel” or “vertical” may include an error within a range that does not impair the effects of the present invention, for example, ± 5 °.

The light extraction member layer 100 includes a film base 110 having a concavo-convex structure including a concavo-convex structure layer (also referred to as a structure layer) 111 and a base film layer 112, a support substrate 131, a film base 110 having a concavo-convex structure, and a support. And an adhesive layer 121 for bonding the substrate 131.
The uneven structure layer 111 is a layer located on the upper surface of the organic EL lighting device 10 (that is, the outermost layer on the light output surface side of the organic EL lighting device 10). The concavo-convex structure layer 111 has a concavo-convex structure including a plurality of concave portions 113 and flat portions 114 positioned around the concave portions 113. Here, since the concave portion 113 is a portion that is relatively depressed as compared with the flat portion 114, the concave portion 113 hits the concave portion according to the present invention, and the flat portion 114 protrudes relative to the concave portion 113, so that the present invention is applied. It hits the convex part. And the light emission surface 10U is prescribed | regulated by the said uneven structure.

  In the present specification, since the drawings are schematic, only a small number of recesses 113 are shown on the light exit surface 10U. However, in an actual organic EL lighting device, one organic A much larger number of recesses can be provided on the light exit surface of the EL lighting device.

(Description of uneven structure)
Hereinafter, the uneven structure of the light exit surface 10U will be described in detail with reference to the drawings.
FIG. 3 is a partial plan view schematically showing an enlarged view of a part of the light exit surface 10U of the organic EL lighting device 10 as viewed from the thickness direction of the organic EL lighting device 10. FIG. 4 is a partial cross-sectional view schematically showing a cross section of the concavo-convex structure layer 111 taken along a plane that passes through the line 3a of FIG. 3 and is perpendicular to the light exit surface 10U. In the following description, unless otherwise specified, “thickness direction” represents the thickness direction of the organic EL lighting device.

  As illustrated in FIG. 3, the light extraction member layer 100 includes a plurality of concave portions 113 including slopes 11 </ b> A to 11 </ b> D and a flat portion 114 positioned around the concave portion 113 on the light output surface 10 </ b> U. Here, the “slope” is a surface that forms an angle that is not parallel to the light exit surface 10U. On the other hand, the surface on the flat part 114 is a flat surface parallel to the light exit surface 10U.

  Each of the plurality of recesses 113 is a regular quadrangular pyramid shaped depression. Accordingly, the slopes 11A to 11D of the recess 113 have the same shape, and the bases 11E to 11H of the regular quadrangular pyramid form a square. In FIG. 3, the line 3 a is a line that passes over all the vertices 11 </ b> P of the row of recesses 113 and is parallel to the bases 11 </ b> E and 11 </ b> G of the recess 113.

  Each recess 113 can have a length of the bases 11F to 11H of usually 1 to 60 μm, preferably 2 to 50 μm. The depth of each recessed part 113 can be normally 1-50 micrometers, Preferably it is 2-40 micrometers.

  The recess 113 is continuously disposed along two orthogonal in-plane directions X and Y at a constant interval. In the in-plane directions X and Y, the portion corresponding to the gap between the adjacent recesses 113 constitutes a flat portion 114. Therefore, the light extraction member layer 100 has alternately the concave portions 113 and the flat portions 114 in the in-plane directions X and Y parallel to the light output surface 10U. Here, of the two in-plane directions X and Y, one in-plane direction X is parallel to the bases 11E and 11G. In the in-plane direction X, the plurality of recesses 113 are aligned at a constant interval 11J. Of the two in-plane directions X and Y, the other in-plane direction Y is parallel to the bases 11F and 11H. In the in-plane direction Y, the plurality of recesses 113 are aligned at a constant interval 11K. Here, the flat part 114 which is a part corresponding to the gap may have a width dimension of usually 0.1 to 20 μm.

As shown in FIG. 4, the angles 11L and 11M formed by the inclined surfaces 11A to 11D constituting the concave portions 113 and the flat portion 114 (and thus the light exit surface 10U) are preferably 40 ° or more, more preferably 45 ° or more, Moreover, 70 degrees or less are preferable and 60 degrees or less are more preferable. Moreover, when the shape of the recessed part 113 is a quadrangular pyramid like this embodiment, it is preferable that the vertex angle 11N shall be 60 degrees-90 degrees. Furthermore, from the viewpoint of increasing the light extraction efficiency while minimizing the change in color depending on the observation angle, the angles 11L and 11M formed by the inclined surfaces 11A to 11D and the flat portion 114 are preferably large. It is preferable that the angle is not less than 60 °, and it is even more preferable that the angle be not less than 60 °. In this case, the upper limit of the corners 11L and 11M is usually 70 ° in consideration of maintaining the durability of the uneven structure layer 111.
In the present embodiment, as shown in FIG. 4, the angles 11L and 11M formed by the inclined surfaces 11A to 11D with the flat portion 114 are set to 60 °. As a result, the apex angle of the regular quadrangular pyramid that forms the recess 113, that is, the angle formed by the opposing inclined surfaces at the apex 11P (the angle 11N shown in FIG. 4 for the angles formed by the inclined surfaces 11B and 11D) is also 60 °. .

Furthermore, in the light emission surface 10U of the organic EL lighting device 10 of the present embodiment, the distances in the thickness direction of the organic EL lighting device 10 between the bottoms of the adjacent concave portions 113 and the tips of the convex portions are uneven within a predetermined range. It may be.
Here, the bottom of the recess 113 indicates the most depressed portion in each of the recesses 113 and indicates the portion where the distance to the light emitting surface 144 in the thickness direction of the organic EL lighting device 10 is the shortest. In the present embodiment, the apex 11P of each recess 113 hits the bottom of the recess 113.
Further, the tip of the convex portion refers to a portion that protrudes most in each convex portion, and refers to a portion that has the longest distance to the light emitting surface 144 in the thickness direction of the organic EL lighting device 10. In the present embodiment, since the flat portion 114 is a flat surface parallel to the light emitting surface 144, the flat portion 114 itself hits the tip of the convex portion.

  Therefore, in the organic EL lighting device 10 of the present embodiment, when the concave portion 113 and the flat portion 114 adjacent to each other on the light exit surface 10U are compared, the bottom of the adjacent concave portion 113 (that is, the vertex 11P of the concave portion 113) and The distance in the thickness direction of the organic EL lighting device 10 (hereinafter, referred to as “the difference in level of adjacent unevenness” as appropriate) H with the tip of the convex portion (that is, the flat portion 114) is uneven within a predetermined range. You can also. At this time, the predetermined range may be a range in which the standard deviation (sample standard deviation) σ is usually 0.05 μm or more, preferably 0.06 μm or more, more preferably 0.08 μm or more.

  By making the height difference H of adjacent unevenness uneven within a predetermined range as described above, the light extraction efficiency from the light exit surface 10U can be improved, and rainbow unevenness due to reflected light can be suppressed. In addition, since the standard deviation σ of the height difference H between adjacent irregularities may be uneven so that it falls within a predetermined range in the entire light exit surface 10U, the recess 113 and the flat portion 114 have excessively high dimensions. Since accuracy is not required, mass production is easy and manufacturing costs can be reduced. Particularly, the lower limit value of the range of the standard deviation σ of the height difference H of the adjacent unevenness is significant in that the brightness profile of the rainbow unevenness is set to 50% or less and the rainbow unevenness cannot be recognized visually.

  The upper limit of the predetermined range is a standard deviation σ and is usually 0.5 μm or less, preferably 0.4 μm or less, more preferably 0.3 μm or less. If the degree of unevenness (variation) in the height difference H between adjacent unevennesses is excessively large, depending on the aspect of the uneven structure, many scratches occur in the production process of the organic EL lighting device 10, and stable production is difficult. There is a risk of becoming.

  In the present embodiment, it is only necessary that one or both of the height of the apex 11 </ b> P of the recess 113 and the height of the flat portion 114 are uneven, so that the height difference H of the adjacent unevenness is uneven. Here, as shown in FIGS. 2 and 4, the heights of the vertices 11 </ b> P of the concave portion 113 are uniform, but the height of the flat portion 114 is not uniform, so that the height difference between adjacent irregularities is different. A description will be given assuming that H is uneven. In addition, when the height of the flat part 114 is uneven as described above, there is a step in the flat part 114, but since the degree of the unevenness is small, the step is also small. Therefore, in FIG. 1 and FIG. 3, illustration of the step in the flat portion 114 is omitted.

As described above, it is not clear why the rainbow unevenness can be suppressed by making the height difference H of the adjacent unevenness uneven so that the standard deviation σ falls within a predetermined range. This is probably due to the following reasons.
When light is irradiated from the outside toward the light exit surface 10U, the light is reflected by the light exit surface 10U, or the light that has entered the organic EL lighting device 10 is reflected by the internal layer interface, and reflected light. Occurs. The reflected light may be diffracted and refracted on the light exit surface 10U when reflected on the light exit surface 10U and when going out from the inside of the organic EL lighting device 10. Conventionally, it is considered that the rainbow unevenness is caused by the interference of the light having the diffraction and refraction described above. On the other hand, in the organic EL lighting device 10 according to the present embodiment, the unevenness of the height difference H between adjacent unevenness on the light exit surface 10U can be reduced, so that the intensity of interference can be reduced. It can be solved.

  The height difference H of the unevenness adjacent to the light exit surface 10U is obtained by randomly extracting measurement points and measuring the height (cross-sectional profile) using a laser microscope (VK-9700: manufactured by Keyence Corporation). Can be sought. Usually, the cross-sectional profile may be measured over a length of 100 μm along a predetermined measurement direction parallel to the light exit surface 10U. Based on the measured cross-sectional profile, a pair of adjacent concave and convex portions is defined as one unit of unevenness, and the maximum value (corresponding to the tip of the convex portion) and the minimum value (corresponding to the bottom of the concave portion) in this uneven unit. And the difference is defined as the height difference H of the concavities and convexities adjacent to each other in one unit of concavity and convexity. Further, from the viewpoint of improving accuracy, the measurement is preferably performed at a plurality of locations, for example, at 15 points. The standard deviation σ may be measured from the height difference H between the adjacent irregularities thus measured. Moreover, what is necessary is just to set the said measurement direction parallel to the direction where the said height difference H becomes the largest, when arrangement | positioning of the unevenness | corrugation in the light emission surface 10U is known beforehand. Further, when the arrangement of the unevenness is unknown, it is only necessary that the standard deviation satisfies the requirement in at least one of the in-plane directions parallel to the light exit surface 10U.

The difference in height H between adjacent irregularities is the maximum value (Ra () of the center line average roughness measured on the light emitting surface 10U along various in-plane directions (various directions in a plane parallel to the light emitting surface 10U). max)) is usually in the range of 1 μm to 50 μm.
In addition, it is possible to define a preferable range of the height difference H between the adjacent unevenness relative to the thickness T of the uneven structure layer 111. For example, when a hard material advantageous for maintaining the durability of the concavo-convex structure layer 111 is used as the material of the concavo-convex structure layer 111, a film substrate having a concavo-convex structure is obtained by reducing the thickness T of the concavo-convex structure layer 111. The flexibility of 110 increases, and the handling of the film substrate 110 having an uneven structure in the manufacturing process of the organic EL lighting device 10 becomes easy. Specifically, it is preferable that the difference TH between the height difference H of adjacent unevenness shown in FIG. 4 and the thickness T of the uneven structure layer 111 is 0 to 30 μm.

  When the concavo-convex structure layer 111 is observed from a direction perpendicular to the light exit surface 10U, the ratio of the area occupied by the flat portion 114 to the total area occupied by the flat portion 114 and the area occupied by the concave portion 113 (hereinafter referred to as “flat portion ratio”). The light extraction efficiency of the organic EL lighting device 10 can be improved by appropriately adjusting “. Specifically, when the flat portion ratio is 10% to 75%, good light extraction efficiency can be obtained, and the mechanical strength of the light exit surface 10U can be increased.

(Description of film base material having uneven structure)
The light extraction member layer 100 may be composed of a plurality of layers, but may be composed of a single layer. In this embodiment, as shown in FIG. 1, the light extraction member layer 100 includes a film base 110 having a concavo-convex structure in which a concavo-convex structure layer 111 and a base film layer 112 are combined. To do.

  The concavo-convex structure layer 111 and the base film layer 112 can usually be formed of a resin composition containing a transparent resin. That the transparent resin is “transparent” means that it has a light transmittance suitable for use in an optical member. In the present embodiment, each layer constituting the light extraction member layer 100 may have a light transmittance suitable for use in an optical member, and the light extraction member layer 100 as a whole has a total light transmission of 80% or more. It is sufficient to have a rate.

The transparent resin contained in the resin composition is not particularly limited, and various resins that can form a transparent layer can be used. Examples thereof include a thermoplastic resin, a thermosetting resin, an ultraviolet curable resin, and an electron beam curable resin. Among them, the thermoplastic resin is easily deformed by heat, and the ultraviolet curable resin is highly curable and efficient, so that the concavo-convex structure layer 11
1 can be formed efficiently and each is preferable.

  Examples of the thermoplastic resin include polyester, polyacrylate, and cycloolefin polymer resins. 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. In addition, the said resin may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  Among these, as the material of the concavo-convex structure layer 111 constituting the film substrate 110 having the concavo-convex structure, from the viewpoint of easily forming the concavo-convex structure of the light exit surface 10U and easily obtaining scratch resistance of the concavo-convex structure, A material with high hardness is preferred. Specifically, when a resin 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, and a material of H or higher is more preferable. The material which becomes 2H or more is more preferable. On the other hand, as the material of the base film layer 112, it is easy to handle the formation of the concavo-convex structure layer 111 and the film base 110 having the concavo-convex structure after forming the film base 110 having the concavo-convex structure. In order to do so, those having a certain degree of flexibility are preferable. By combining such materials, it is possible to obtain a film substrate 110 having a concavo-convex structure that is easy to handle and excellent in durability, and as a result, the high-performance organic EL lighting device 10 can be easily manufactured. it can.

  Such a combination of materials can be obtained by appropriately selecting the transparent resin exemplified above as the resin constituting each material. Specifically, an ultraviolet curable resin such as acrylate is used as the transparent resin constituting the material of the concavo-convex structure layer 111, while the transparent resin constituting the material of the base film layer 112 is made of an alicyclic olefin polymer. It is preferable to use a film (such as a ZEONOR film described later) or a polyester film.

  When the light extraction member layer 100 includes the concavo-convex structure layer 111 and the base film layer 112 as in this embodiment, the refractive index of the concavo-convex structure layer 111 and the base film layer 112 may be as close as possible. . In this case, the refractive index difference between the uneven structure layer 111 and the base film layer 112 is preferably within 0.1, and more preferably within 0.05.

  As a material of a layer that is a constituent element of the light extraction member layer 100 such as the concavo-convex structure layer 111 and the base film layer 112, a light diffusing material may be used. Thereby, since the light which permeate | transmits the light extraction member layer 100 can be diffused, the change of the tint by an observation angle can further be reduced. In the case where a light diffusing material is used for one layer of the light extraction member layer, it is preferable that the layer having the light diffusing material is on the inner side than the concavo-convex structure layer 111. In addition, the flame retardant particles themselves described later can function as a light diffusing material.

  Examples of the light diffusing material include a material containing particles, and an alloy resin that diffuses light by mixing two or more kinds of resins. Among these, from the viewpoint that the light diffusibility can be easily adjusted, a material including particles is preferable, and a resin composition including particles is particularly preferable.

  The particles may be transparent or opaque. Examples of the material of the particles include metals and metal compounds, and resins. 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; metal compounds such as silicon oxide, aluminum oxide, zirconium oxide, silicon nitride, tin-added indium oxide, and titanium oxide. be able to. On the other hand, examples of the resin include methacrylic resin, polyurethane resin, and silicone resin. In addition, the particle | grain material may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

The shape of the particles can be, for example, 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 diameter of the particles is preferably 0.1 μm or more, preferably 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.

  In the case where 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. More preferably, it is 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 may be difficult to be suppressed. Conversely, if the difference is too large, the diffusion becomes large and the color unevenness is suppressed, but light Extraction effect may be reduced.

  The content ratio of the particles is a volume ratio in the total amount of the layer including all particles (including the flame retardant) exceeding 0.4 μm, preferably 1% or more, more preferably 5% or more, and 80% or less. Preferably, 50% or less is more preferable. By setting the content ratio of the particles to be equal to or higher than the lower limit, desired effects such as reduction of a change in color depending on the observation angle can be obtained. Moreover, by setting it as this upper limit or less, aggregation of particle | grains can be prevented and particle | grains can be disperse | distributed stably.

  Furthermore, the resin composition can contain arbitrary components as needed. Examples of the optional component include additives such as phenol-based and amine-based degradation inhibitors; surfactant-based, siloxane-based antistatic agents; triazole-based, 2-hydroxybenzophenone-based light-resistant agents; Can be mentioned.

The thickness T of the uneven structure layer 111 is not particularly limited, but is preferably 1 μm to 70 μm. In this embodiment, the thickness T of the concavo-convex structure layer 111 is the distance between the surface on the base film layer 112 side where the concavo-convex structure is not formed and the flat portion 114 of the concavo-convex structure.
Moreover, it is preferable that the thickness of the base film layer 112 is 20 micrometers-300 micrometers.

(Support substrate)
The organic EL lighting device 10 of the present embodiment includes a support substrate 131 between the organic EL element 140 and the film layer 110 having an uneven structure. Examples of the material constituting the support substrate 131 include glass and resin. In addition, the material of the support substrate 131 may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. In the case of glass, the organic EL lighting device 10 can be given rigidity for suppressing deflection. Further, the glass base material is provided with a substrate that is excellent in the performance of sealing the organic EL element 140 and that can easily form the layers constituting the organic EL element 140 sequentially in the manufacturing process. Thus, the durability of the organic EL lighting device 10 can be improved and the manufacturing can be facilitated.

The refractive index of the support substrate is not particularly limited, but is preferably 1.5 to 2.1. Since the organic EL element or the transparent electrode layer has a high refractive index, reflection is reduced at the interface. Therefore, it is more preferable that the refractive index is 1.65 or more and 2.0 or less.
The thickness of the support substrate 131 is not particularly limited, but is preferably 0.05 mm to 1.1 mm.

(Adhesive layer)
The lighting device 10 of this embodiment includes an adhesive layer 121 between the film layer 110 having a concavo-convex structure and the support substrate 131. The adhesive layer 121 is a layer that is interposed between the base film layer 112 of the multilayer body 110 and the support substrate 131 and adheres these two layers.
The adhesive that is the material of the adhesive layer 121 is not only a narrowly defined adhesive (a so-called hot melt type adhesive having a shear storage modulus of 1 to 500 MPa at 23 ° C. and not exhibiting tackiness at room temperature), A pressure-sensitive adhesive having a shear storage modulus at 23 ° C. of less than 1 MPa is also included. Specifically, a material having a refractive index close to that of the support substrate 131 or the base film layer 112 and transparent can be used as appropriate. More specifically, an acrylic adhesive or a pressure-sensitive adhesive can be used. The thickness of the adhesive layer is preferably 5 μm to 100 μm.

(Flame retardant particles)
In the present invention, at least one layer of the light extraction member layer 100 such as the concavo-convex structure layer 111, the base film layer 112, and the adhesive layer 121 includes flame retardant particles having an average particle diameter of 0.4 μm or less. In view of the effect of the flame retardant particles, it is preferable that the outermost layer (uneven structure layer 111 in the present embodiment) of the light emitting surface of the organic EL lighting device contains the flame retardant particles. The flame retardant is a particle, and the average particle diameter of the flame retardant particles is a 50% cumulative particle diameter measured with a diffraction / scattering particle size analyzer and can be measured by a laser diffraction / scattering method. The average particle size of the flame retardant particles is preferably 0.4 μm or less, more preferably 0.2 μm or less. The lower limit of the average particle diameter of the flame retardant particles is not particularly limited, but is 0.001 μm or more, more preferably 0.01 μm or more. When the particle diameter is larger than this range, the haze of the light extraction member layer becomes high and the color becomes yellow, which is not preferable. When the particle diameter is small, the effect of increasing the viscosity is high and it is difficult to form a member layer, which is not preferable. Commercially available flame retardant particles can be used, but when the particle size of the commercially available flame retardant particles does not satisfy this range, it is necessary to use a pulverizer or the like to obtain a desired particle size.

  Flame retardant particles include halogenated organic compounds, red phosphorus, condensed phosphate esters, reactive phosphate esters, polyphosphate ammonium compounds, organophosphate compounds typified by metal phosphate compounds, melamine phosphate And melamine compounds represented by melamine cyanurate and the like. It can also be selected from inorganic hydroxides such as aluminum hydroxide and magnesium hydroxide, and inorganic compounds represented by aluminum oxide hydrate, borate, antimony oxide, and the like. The flame-retardant materials represented by these may be used alone or in combination. Preferred for the purposes of the present application are phosphorous flame retardant particles and inorganic hydroxide flame retardant particles. The flame-retardant materials represented by these may be used alone or in combination. Moreover, when making a 2 or more layers of a light extraction member layer contain a flame retardant particle, the flame retardant particle added for every layer may be changed, and the same flame retardant particle may be used.

  The flame retardant particles are used by mixing with each material constituting the light extraction member layer. The total amount of the flame retardant particles is 3% by weight or more, preferably 5% by weight, based on the total amount of each layer of the light extraction member. More preferably, it is 7% by weight or more. The upper limit of the content of the flame retardant particles is 70% by weight or less, more preferably 50% by weight or less. When the amount of the flame retardant particles is within this range, there are advantages that the flame retardancy is maintained and the formation of the member layer is easy.

(Sealing substrate)
The light emitting element 10 of the present embodiment includes a sealing substrate 151 on the light emitting surface 145. The sealing substrate 151 may be provided so as to be in direct contact with the light emitting surface 145. Further, an arbitrary substance such as a filler or an adhesive may be present between the light emitting surface 145 and the sealing substrate 151, or a gap may be present. As long as there is no inconvenience such as greatly impairing the durability of the light emitting layer 142, air or other gas may be present in the space, or the space may be evacuated.

  As the sealing substrate 151, any member that can seal the organic EL element 140 and transmits light emitted from the light emitting surface 145 can be used. For example, a member similar to the support base 131 can be used.

(Production method)
The manufacturing method of the organic EL lighting device 10 is not particularly limited. For example, each layer constituting the organic EL element 140 is stacked on one surface of the support substrate 131, and after or before that, the other surface of the support substrate 131 is stacked. The film base 110 having a concavo-convex structure having the concavo-convex structure layer 111 and the base film layer 112 can be manufactured by sticking the adhesive through the adhesive layer 121.

The film substrate 110 having an uneven structure including the uneven structure layer 111 and the base film layer 112 is manufactured by, for example, preparing a mold such as a mold having a desired shape, and forming the uneven structure layer 111 from this mold. This can be done by transferring to a layer of material. As a more specific method,
(Method 1) An unprocessed concavo-convex structure having a layer of the resin composition A constituting the base film layer 112 and a layer of the resin composition B constituting the concavo-convex structure layer 111 (the concavo-convex structure is not yet formed) A method of forming a concavo-convex structure on the surface of the resin composition B side of the film base having a raw concavo-convex structure;
(Method 2) On the base film layer 112, the resin composition B in a liquid state is applied, a mold is applied to the layer of the applied resin composition B, and the resin composition B is cured in that state, thereby forming irregularities. A method for forming the structural layer 111 can be given.

In Method 1, a film substrate having an unprocessed uneven structure can be obtained by, for example, extrusion molding in which the resin composition A and the resin composition B are coextruded. A concavo-convex structure can be formed by pressing a mold having a desired surface shape onto the surface of the film base having a raw concavo-convex structure on the resin composition B side.
More specifically, a film base having a raw concavo-convex structure is formed by continuously forming a film base having a long raw concavo-convex structure by extrusion molding, and a transfer roll having a desired surface shape and a nip roll. The material can be pressurized so that continuous production can be performed efficiently. The pinching pressure between the transfer roll and the nip roll is preferably several MPa to several tens of MPa. The temperature at the time of transfer is preferably Tg or more (Tg + 100 ° C.) or less, where Tg is the glass transition temperature of the resin composition B. The contact time between the film base material having an unprocessed concavo-convex structure and the transfer roll can be adjusted by the feed speed of the film, that is, the roll rotation speed, and is preferably from 5 seconds to 600 seconds.

  In Method 2, as the resin composition B constituting the concavo-convex structure layer 111, it is preferable to use a composition that can be cured by energy rays such as ultraviolet rays. The resin composition B is applied on the base film layer 112, and in a state where the mold is applied, the resin composition B is located on the back side of the application surface (the side opposite to the surface on which the resin composition B is applied). By irradiating energy rays such as ultraviolet rays from a light source, curing the resin composition B, and then peeling off the mold, the coating film of the resin composition B is used as the concavo-convex structure layer 111, and the film substrate 110 having the concavo-convex structure. Can be obtained.

When the film substrate having the concavo-convex structure is composed only of the concavo-convex structure layer 111 (Method 3), the layer of the resin composition B constituting the concavo-convex structure layer 111 (the concavo-convex structure is not yet formed) A method of forming a concavo-convex structure on a surface of the film base having a raw concavo-convex structure having the raw concavo-convex structure and forming the concavo-convex structure on the surface of the resin composition B side of the film concavo-convex structure (Method 4) The liquid resin composition B is applied on the film layer, a mold is applied to the applied resin composition B layer, the resin composition B is cured in this state, and the concavo-convex structure layer 111 is formed. The film for peeling can be formed by a method of peeling from the concavo-convex structure layer.

[2. Second embodiment]
In the organic EL lighting device of the present invention, the shape of the concave portion and the convex portion constituting the light exit surface is not limited to the pyramid shape exemplified in the first embodiment, and may be a truncated pyramid shape. Here, the truncated pyramid shape refers to a shape in which a flat portion is provided at the top of the pyramid and the surface is flattened. Hereinafter, the example will be described with reference to the drawings. In the second embodiment as well, at least one layer of the light extraction member layer 200 such as the concavo-convex structure layer 211, the base film layer 112, and the adhesive layer 121 has an average. Including flame retardant particles having a particle size of 0.4 μm or less.

5 and 6 are views for explaining the organic EL lighting device according to the second embodiment of the present invention. FIG. 5 is a perspective view schematically showing the organic EL lighting device, and FIG. 5 is a cross-sectional view schematically showing a cross section of the concavo-convex structure layer of the organic EL lighting device shown in FIG.
As shown in FIG. 5, the organic EL lighting device 20 according to the second embodiment is formed on the light exit surface 20 </ b> U that is the surface of the concavo-convex structure layer 211 in the film base 210 having the concavo-convex structure constituting the light extraction member layer 200. Except for the shape of the recessed portion 213 being different, the configuration is the same as that of the first embodiment.

  As shown in FIG. 6, the recess 213 formed on the surface of the concavo-convex structure layer 211 has a shape in which the top of a regular quadrangular pyramid is chamfered flat (pyramidal frustum shape), and has a constant interval on the light emitting surface 20U. Is provided. A gap is provided between adjacent recesses 213, and this gap constitutes a flat portion 214. Furthermore, since the concave portion 213 has a truncated pyramid shape, the concave portion 213 has a bottom surface portion 21P at the bottom as a flat surface parallel to the light output surface 20U.

  Further, also in the present embodiment, the height difference H of the unevenness adjacent to the light exit surface 20U is uneven so that the standard deviation σ falls within a predetermined range. In the present embodiment, the bottom surface portion 21P hits the bottom of the concave portion 213, and the flat portion 214 hits the tip of the convex portion. Therefore, in the organic EL lighting device 20, when the adjacent concave portion 213 and the convex portion 214 are compared, the distance between the bottom surface portion 21P and the flat portion 214 in the thickness direction of the organic EL lighting device 20 (that is, adjacent) The height difference (H of the matching irregularities) is uneven so that the standard deviation σ falls within a predetermined range. In the present embodiment, as shown in FIG. 6, the height of the flat part 214 is uniform, but the height of the bottom surface 21P is not uniform, so that the difference in height H between adjacent irregularities is not uniform. An example is shown. However, although the height of the bottom surface portion 21P is uniform, the height difference H of the adjacent unevenness may be uneven due to the unevenness of the height of the flat portion 214. The height difference H of the adjacent unevenness | corrugation may become uneven because both the heights of the flat part 214 become uneven.

  Even in the case of having the light exit surface 20U having the concave portion 213 having the shape of the truncated pyramid shape and the flat portion 214 that is a gap therebetween, the light extraction efficiency is increased as in the first embodiment, and , Rainbow unevenness can be suppressed. Also, if dust and debris accumulate in the recess 213, the light extraction efficiency may decrease and bright spots may be generated. However, if the bottom of the recess 213 is a flat bottom surface portion 21P, In addition, it is preferable because fragments and the like hardly accumulate. Furthermore, according to this embodiment, the same advantage as 1st embodiment can also be acquired.

As in the present embodiment, when the recess 213 has a truncated pyramid shape, the height of the bottom surface portion 21P and the top portion 21Q when the top portion of the truncated pyramid is not flat but a sharp pyramid shape. The difference 21R may normally be 20% or less of the height 21S of the pyramid when the top of the truncated pyramid is not flat and has a sharp pyramid shape.
Moreover, when the shape of the recessed part 213 is a truncated pyramid shape, let the angle of slopes 212A and 213B except the bottom face part 21P be an angle of a slope. The light extraction efficiency can be increased by setting the angle of the inclined surface of the recess 213 to such an angle. However, the slopes are not necessarily all at the same angle, and slopes having different angles may coexist within the above range.

[Third embodiment]
In the organic EL lighting device of the present invention, a configuration in which flame retardant particles are included in a diffusion layer that does not particularly provide a concavo-convex structure on the light exit surface side may be employed. FIG. 7 is a perspective view schematically showing an organic EL lighting device according to the third embodiment of the present invention, and FIG. 8 is a cross-sectional view showing another example of the third embodiment. As shown in FIG. 7, the organic EL lighting device 30 according to the third embodiment does not have a concavo-convex structure unlike the first embodiment and the second embodiment on the light exit surface 30U of the organic EL lighting device, and diffuses light. The configuration is the same as that of the first embodiment or the second embodiment except that the diffusion layer 311 having the property is provided. The organic EL lighting device 40 according to another third embodiment shown in FIG. 8 does not have a regular uneven structure as in the first embodiment or the second embodiment on the light exit surface 40U of the organic EL lighting device. Except for having a diffusion layer 411 having a light diffusivity having a concavo-convex structure due to protrusion of particles, it has the same configuration as in the first embodiment and the second embodiment (only in the embodiment of FIG. 40D schematically shows a state where 40D is scattered and protrudes in the diffusion layer).
Here, as the material for forming the diffusion layer, a diffusible material can be used. For example, a material containing particles, an alloy resin that mixes two or more kinds of resins, and diffuses light can be used. Can be mentioned. Among these, from the viewpoint that the light diffusibility can be easily adjusted, a material including particles is preferable, and a resin composition including particles is particularly preferable.

  The particles may be transparent or opaque. Examples of the material of the particles include metals and metal compounds, and resins. 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; metal compounds such as silicon oxide, aluminum oxide, zirconium oxide, silicon nitride, tin-added indium oxide, and titanium oxide. be able to. On the other hand, examples of the resin include methacrylic resin, polyurethane resin, and silicone resin. In addition, the particle | grain material may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

The shape of the particles can be, for example, 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 diameter of the particles is preferably 0.4 μm or more, preferably 100 μm or less, more preferably 50 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, the smaller the particle size, the smaller the desired effect, such as a reduction in the change in color depending on the viewing angle, and the improvement in light extraction efficiency, but the smaller the particle size, the more effective the diffusion effect. May decrease. If the particles are large, they tend to protrude from the surface, which may increase the extraction efficiency. However, if the particles are too large, application to the substrate may be difficult. When the particle shape is other than spherical, the diameter of the sphere having the same volume is used as the particle size.

  In the case where 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. More preferably, it is 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 may be difficult to be suppressed. Conversely, if the difference is too large, the diffusion becomes large and the color unevenness is suppressed, but light Extraction effect may be reduced.

  The content ratio of the particles is a volume ratio in the total amount of the layer including all particles (including flame retardant particles) exceeding 0.4 μm, preferably 1% or more, more preferably 5% or more, and 80% or less. Is preferable, and 50% or less is more preferable. By setting the content ratio of the particles to be equal to or higher than the lower limit, desired effects such as reduction of a change in color depending on the observation angle can be obtained. Moreover, by setting it as this upper limit or less, aggregation of particle | grains can be prevented and particle | grains can be disperse | distributed stably.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the following examples, “parts” and “%” representing the quantity ratio of materials represent weight ratios unless otherwise specified.

<Evaluation of flame retardancy>
For the evaluation of flame retardancy, the test pieces were tested for flame retardancy and classified based on the UL94 test (Underwriters Laboratories). That is, UL94 (Underwriters Laboratories) fire resistance class was calculated | required about the test piece obtained from each mixture using the test piece which bonded the sheet | seat. The UL94 class is as follows.
V-0: The after flame time is 10 seconds or less, the total after flame time when the flame is contacted 10 times or less is 50 seconds or less, no burning drops, no burnout of the test piece, the residual time of the test piece after completion of the flame contact Is less than 30 seconds.
V-1: Afterflame time after completion of flame contact is 30 seconds or less, Total afterflame time after flame contact 10 times is 250 seconds or less, Residual time of test piece after flame contact is 60 seconds or less, etc. Is the same as V-0.
V-2: The cotton indicator is ignited by the combustion dripping material. Other criteria are the same as V-1.
Classification not possible (ucl): Fire resistance class V-2 is not satisfied.

[Example 1]
<1-1. Production of flame retardant particles>
(Production of flame retardant particles 1)
1 kg of aluminum hydroxide-based flame retardant particles (Navaltech Apiral 40CD (average particle size 1.3 μm)) was pulverized in a bead mill (Ashizawa Finetech Starmill ZRS4) with 1 kg of water for 2 hours and then dried. Thus, flame retardant particles 1 were prepared. When an average particle size (50% cumulative particle size) was measured by a laser diffraction / scattering particle size analyzer (Microtrack BlueRaytrac, manufactured by Nikkiso Co., Ltd.), it was 0.2 μm.

(Production of flame retardant particles 2)
1 kg of 5 kg of commercially available aluminum diethylphosphinate (average particle size is about 22 μm) is ground in a bead mill (Star Mill ZRS4 manufactured by Ashizawa Finetech Co., Ltd.) with 1 kg of water for 8 hours and then dried to obtain flame retardant particles. 2 was obtained. It was 0.06 micrometer when the average particle diameter was measured similarly to the flame retardant particle | grains 1. FIG.

<1-2. Production of resin composition>
(Production of resin composition 1)
2 parts of 2-methacryloyloxyethyl isocyanate, 37 parts of trimethylolpropane triacrylate, 57 parts of ethoxylated phenyl acrylate, and 3 parts of photoinitiator (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) are mixed, and UV curable. A coating solution was prepared. Further, particles having a diameter of 2 μm (silicone resin, Tospearl 110, manufactured by Momentive Materials), flame retardant particles 1 and flame retardant particles 2 were added, and the particles were dispersed by stirring to produce a resin composition 1. The content ratios of the silicone particles, the flame retardant particles 1 and the flame retardant particles 2 were 5, 10, and 10% by weight in the total amount of the resin composition 1, respectively.

(Manufacture of coating liquid 1)
In a solvent in which methylcyclohexane and ethyl acetate are mixed at 8: 2 (weight ratio), a resin mainly composed of an acid-modified polyolefin resin (refractive index 1.49, Cornova MPO-B130C) is dissolved, and flame retardant particles 1 are obtained. The mixture was added and stirred to disperse the particles, thereby preparing a coating solution 1 as a material for the adhesive layer. The concentration of the acid-modified polyolefin resin was 15% by weight in the total amount of the coating liquid 1. The density | concentration with the flame retardant particle | grains 1 was 30 weight% in solid content whole quantity (total of acid-modified polyolefin resin and particle | grains).

(Manufacture of coating liquid 2)
In a solvent in which methylcyclohexane and ethyl acetate are mixed at 8: 2 (weight ratio), a resin mainly composed of an acid-modified polyolefin resin (Cornova MPO-B130C, refractive index 1.49, manufactured by Nippon Cima) is dissolved. Add flame retardant particles 1 and particles with a diameter of 2 μm (silicone resin, Tospearl 110, manufactured by Momentive Materials Co., Ltd.) and stir to disperse the particles, thereby preparing a coating liquid 2 to be a material for the second light diffusion layer did. The concentration of the acid-modified polyolefin resin was 15% by weight in the total amount of the coating liquid 2. The concentrations of the silicone particles and the flame retardant particles 1 were 5 to 30% by weight in the total solid content (total of acid-modified polyolefin resin and particles), respectively.

<1-3. Production of base film 1 with adhesive layer>
The coating liquid 1 was applied to the base film (75 μm thick polyethylene terephthalate film) in two portions, and the coating layer was dried to form a 45 μm thick adhesive layer (that is, the second light diffusion layer). . A separator was laminated on the adhesive layer to obtain a base film 1 with an adhesive layer having a layer structure of (base film)-(adhesive layer)-(separator).

<1-4. Production of optical sheet 1>
On the surface of the base film 1 with the adhesive layer, the resin composition 1 was applied in a thickness of 30 μm on the surface where the base film was exposed, and a metal mold having a predetermined shape was pressed onto the coating film. . In this state, the coating film of the resin composition 1 is irradiated from the separator side with ultraviolet light with an integrated light amount of 1 J / cm ² to cure the coating film and form a concavo-convex structure layer. Material film) An optical sheet (light extraction member layer) 1 having a layer structure of one (adhesive layer) and one (separator) was obtained. The shape of the surface of the metal mold is a shape in which regular quadrangular pyramids having an apex angle of 60 degrees and a base of 15 μm are arranged without gaps, and on the surface of the obtained first light diffusion layer, the shape of the quadrangular pyramids is inverted. An indentation was provided.

<1-5. Flame retardant evaluation>
The separator of the optical sheet 1 was peeled off, overlapped with an adhesive layer, and two optical sheets 1 were attached so that the concavo-convex structure layer was on both sides to make a 300 μm thick sample, and a UL94 test was performed. The total flame time of 10 times was 192 seconds in total, and no flame after 30 seconds was observed. Residual time and indicator material ignition state also satisfied the V-2 standard.

<1-6. Formation of organic EL element>
On one main surface of a glass substrate having a thickness of 0.7 mm, a transparent electrode layer 100 nm, 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 100 nm. Were 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 material forming each layer from the transparent electrode layer to the reflective electrode layer is as follows:
-Transparent electrode layer 1 Tin-added indium oxide (ITO)
・ Hole transport layer 14, 4 ′ one bis [N one (naphthyl) one N one phenylamino] biphenyl (α one NPD)
-Yellow light emitting layer 1 rubrene 1.5 wt% added α-NPD
Blue light emitting layer 1 Addition of 10% by weight of iridium complex 4,4′-dicarbazolyl 1,1′-biphenyl (CBP)
-Electron transport layer 1 Phenanthroline derivative (BCP)
・ Electron injection layer Lithium monofluoride (LiF)
・ Reflective electrode layer lAI
The transparent electrode layer was formed by a reactive sputtering method using an ITO target, and the surface resistance was 10Ω / □ or less. In addition, the formation from the hole injection layer to the reflective electrode layer is carried out by placing a glass substrate on which a transparent electrode layer has already been formed in a vacuum evaporation apparatus, and successively using the resistance heating method for the materials from the hole transport layer to the reflective electrode layer. This was done by vapor deposition. 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 was attached to the electrode layer, and the hole transport layer to the reflective electrode layer were sealed with a sealing member to obtain an organic EL element.

<1-7. Manufacturing of lighting equipment>
The separator of the optical sheet 1 obtained in the above (1-4) was peeled off, and this was attached to the organic EL element obtained in (1-6). The pasting was performed such that the exposed adhesive layer adhered to the glass substrate of the organic EL element. Thereby, the illuminating device 1 was obtained. The obtained illuminating device 1 had a rectangular light exit surface capable of emitting white light from the first light diffusion layer of the optical sheet 1.

<1-8. Evaluation of chromaticity and efficiency>
About the illuminating device 1 obtained by said (1-7), chromaticity and efficiency were measured as follows. A color luminance meter (BM-7A manufactured by Topcon Techno House Co., Ltd.) was installed in the normal direction of the light exit surface of the device, a constant current of 100 mA / m 2 was applied to the lighting device 1, and chromaticity (x, y) was measured. Further, the total luminous flux was measured with an integrating sphere (for example, manufactured by SPX-8X Sphere Optics), and the value when the value when the optical sheet 1 was not attached was set to 1 was taken as the efficiency. The results are shown in Table 1.

[Example 2]
In the production of the resin composition, the optical sheet 2 and the illumination are illuminated in the same manner as in Example 1 except that 20% by weight of the flame retardant particles 2 is added to the total amount of the resin composition without adding the flame retardant particles 1. Device 2 was manufactured. The evaluation results are shown in Table 1.

Example 3
In the production of the resin composition, the optical sheet 3 and the illumination are the same as in Example 1 except that 20% by weight of the flame retardant particles 1 is added to the total amount of the resin composition without adding the flame retardant particles 2. Device 3 was manufactured. The evaluation results are shown in Table 1.

Example 4
In the production of the coating liquid, the optical sheet 4 and the illumination device 4 were produced in the same manner as in Example 2 except that the flame retardant particles 1 were not added. The evaluation results are shown in Table 1.

Example 5
An optical sheet 5 and a lighting device 5 were manufactured in the same manner as in Example 1 except that the coating liquid 2 was used in the manufacture of the base film with an adhesive layer. The evaluation results are shown in Table 1.

Example 6
Optical sheet in the same manner as in Example 2 except that in the production of the resin composition, the particle having a diameter of 2 μm is changed to 10% of a silicone resin having a diameter of 12 μm (Tospearl 3120, manufactured by Momentive Materials) and the surface is not molded. 6 and the lighting device 6 were manufactured. The evaluation results are shown in Table 1.

[Comparative Example 1]
Non-pulverized aluminum diethylphosphinate (average particle diameter is about 22 μm) is used in place of the flame retardant particles 2 in the production of the resin composition, and is not crushed in place of the flame retardant particles 2 in the production of the coating liquid. An optical sheet 7 and an illuminating device 7 were produced in the same manner as in Example 2 except that aluminum hydroxide-based flame retardant particles (Navaltech Apiral 40CD (average particle size 1.3 μm)) were used. The evaluation results are shown in Table 2.

[Comparative Example 2]
In the production of the resin composition, diethyl phosphinate that has not been crushed is used instead of the flame retardant particles 2 (average particle size is about 22 μm), and in the production of the coating liquid, it is crushed in place of the flame retardant particles 2. An optical sheet 8 and an illuminating device 8 were produced in the same manner as in Example 6 except that no aluminum hydroxide-based flame retardant particles (Navaltech Corp. Apiral 40CD (average particle size 1.3 μm)) were used. The evaluation results are shown in Table 2.

[Comparative Example 3]
In the production of the resin composition and the coating liquid, an optical sheet 8 and a lighting device 8 were produced in the same manner as in Example 1 except that no flame retardant was added. The evaluation results are shown in Table 2.

From the above examples, it can be seen that Comparative Example 3 in which no flame retardant particles were added had a problem in flame retardancy. Further, when the particle diameter of the flame retardant particles is out of the range, it can be seen that there is a problem in light extraction efficiency and color.

DESCRIPTION OF SYMBOLS 10 Organic EL lighting device 11A-11D Slope 11E-11H Bottom of pyramid shape of recessed part 11J, 11K Space | interval of recessed part 11L, 11M Angle formed by the inclined surface of the recessed part and the flat part 11N Square pyramid apex angle 11P Quadrangular pyramid apex 10U Light exit surface 100 Light extraction member layer 110 Film substrate having concavo-convex structure 111 Concavity and convexity structure layer 112 Substrate film layer 113 Concave portion 114 Flat portion 121 Adhesive layer 131 Support substrate 140 Organic EL element 141 First electrode Layer 142 Light emitting layer 143 Second electrode layer 144 Surface of organic EL element (light emitting surface)
145 Surface of organic EL element 151 Sealing substrate 20 Organic EL lighting device 20U Light exit surface 21P Bottom surface portion 200 Light extraction member layer 210 Film substrate having uneven structure 211 Uneven structure layer 213 Recess 213A, 212B Slope 214 Flat portion 30 Organic EL lighting device 30U light exit surface 300 light extraction member layer 310 diffusive film base material 311 diffusion layer 40 organic EL illumination device 40U light output surface 400 light extraction member layer 410 diffusive film base material 411 diffusion layer 40D diffusion particle

T Thickness of uneven structure layer H Height difference of adjacent unevenness

Claims (5)

An illumination device in which an organic electroluminescence element and a light extraction member layer are provided on the light emission surface side of the organic electroluminescence element,
The light extraction member layer is composed of at least two layers, and the outermost surface layer of the light exit surface is a flame retardant particle having an average particle diameter of 0.4 μm or less and a light diffusive material having an average particle diameter exceeding 0.4 μm. A lighting device characterized by being a structural layer containing   The lighting device according to claim 1, wherein the flame retardant particles are phosphorus-based flame retardant particles or inorganic hydroxide particles. Of the light extracting members layer, a layer of organic electroluminescent side lighting device according to claim 1 or 2 which is a diffusion layer.   The lighting device according to any one of claims 1 to 3, wherein a ratio of the flame retardant particles having an average particle diameter of 0.4 µm or less in the light extraction member layer is 3 wt% or more and 70 wt% or less.   The lighting device according to any one of claims 1 to 4, wherein a ratio of the light diffusing material having an average particle diameter of 0.4 µm or more in the light extraction member layer is 1% or more and 80% or less on a volume basis.

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