JP2013163384A - Optical laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical laminate having superior productivity.SOLUTION: An optical laminate for lamination on a surface of an organic electroluminescent element has a base material film, an optically functional layer with an uneven structure comprising a photocurable resin arranged at a surface side of the base material film, and an adhesive layer arranged at a back side of the base material film, wherein either layer of the base material film, the optically functional layer or the adhesive layer comprises a composition containing a pigment, a fluorescent material and a luminous material.

Description

  The present invention relates to an optical laminate, and more particularly, to an optical laminate excellent in productivity.

  A light emitting body (light emitting layer) of an organic electroluminescence element (hereinafter sometimes referred to as “organic EL element”) can have a planar shape, and the color of the light is white or a color close thereto. Therefore, it is considered to be used as a light source of a lighting fixture that illuminates a space such as a living environment or as a backlight device of a liquid crystal display device, for example. When using an organic EL element as a lighting fixture, it is common to use a white organic EL element. As the white organic EL element, a stacked type or tandem type, in which a light emitting layer that generates a light emission color having a complementary color relationship is stacked, is often used. These laminates of light emitting layers are mainly yellow / blue or green / blue / red laminates.

  When an organic EL element is used as a surface light source, there is a problem of increasing its light extraction efficiency. That is, although the light emitting layer itself of the organic EL element has high luminous efficiency, the light amount is reduced by interference in the layer until it emits light through the laminated structure constituting the element. Such light loss is required to be reduced as much as possible. As means for increasing the light extraction efficiency, for example, as disclosed in Patent Document 1, an optical film having a concavo-convex structure formed on the surface is disclosed on the light emission side of an organic EL element. Patent Document 1 discloses that the optical film is obtained by an injection molding method using a mold having an uneven surface to which an uneven structure is transferred.

International Publication WO2004 / 017106 Pamphlet

However, when an optical film is manufactured by an injection molding method, it is not always efficient, and the productivity of the optical film is not always sufficient. Also, using the so-called 2P method, a photocurable resin is placed between the base film and a mold on which a predetermined uneven surface is formed, and the photocurable resin is irradiated with light to cure the resin. The method of making it is also being studied. However, when an optical film (optical laminate) is manufactured by such a method, the optical laminate is likely to be curled (easily warped). For example, the optical film is bonded to the back side of the optical laminate. When a post-process such as providing a layer smoothly is performed, there is a problem that the post-process cannot be efficiently performed. For this reason, the productivity of the optical laminate is not necessarily sufficient.
In addition, the above problems are common not only to optical films used by being attached to organic EL elements but also to optical films (optical laminates) used for various light source devices and display devices.

  An object of the present invention is to provide an optical laminate having excellent productivity.

According to the present invention, the following inventions (D1) to (D4) are provided. In the present application, the following (1) to (10) are disclosed.
(D1) a base film;
An optical functional layer having a concavo-convex structure made of a photocurable resin, provided on the surface side of the base film;
It has an adhesive layer provided on the back side of the substrate film, and is an optical laminate for sticking to the surface of an organic electroluminescence element,
Any one of the base film, the optical functional layer, and the adhesive layer is an optical laminate including a composition containing a pigment, a fluorescent material, and / or a phosphorescent material.
(D2) The uneven structure is
The optical layered body according to (D1), including a cone, a frustum, a hemisphere, or a linear shape.
(D3) The optical laminated body according to (D1) or (D2), wherein the optical functional layer contains the pigment, and the content ratio of the pigment in the optical functional layer is 0.1 to 5% by volume.
(D4) The optical functional layer includes the fluorescent material or the phosphorescent material, and the content ratio of the fluorescent material or the phosphorescent material in the optical functional layer is 0.1 to 20% by volume (D1) or The optical laminate according to any one of (D2).
(1) a base film, an optical functional layer provided on the front side of the base film, an adhesive layer provided on the back side of the base film, a separator film provided on the back side of the adhesive layer, And a method for producing an optical laminate used by being attached to the surface of a display device, wherein the back surface side of the base film and the separator film are bonded via the adhesive layer. A base material layer forming step for forming a material layer, a mold preparing step for preparing a mold having a shape imparting surface for imparting a surface shape of the optical functional layer, a shape imparting surface of the mold, and the optical laminate base A resin placement step of placing a photocurable resin between the surface of the material layer and the base film side, and irradiating light to the placed photocurable resin to cure the photocurable resin The light that forms the optical functional layer Functional layer forming step and the formation process for the preparation of the optical functional layer and the shaping surface and the peeled off releasing step and, the optical stack comprising a.
(2) The said optical function layer formation process is a manufacturing method of the said optical laminated body which irradiates light from the said separator film side with respect to the said photocurable resin.
(3) The resin disposing step includes an disposing step of disposing the photocurable resin on the surface of the base film, and a contact for abutting the shape imparting surface of the mold against the disposed photocurable resin. And a method for producing the optical layered body.
(4) The optical functional layer is a concavo-convex structure layer having a concavo-convex structure formed on a surface thereof, and the shape imparting surface is a concavo-convex surface onto which the shape of the concavo-convex structure is transferred. .
(5) The base layer forming step includes an application step of applying an adhesive constituting the adhesive layer to the back side of the base film, and a surface of the base film on which the adhesive is applied. And a lamination step of laminating the separator film.
(6) The base film and the separator film are each formed in a long shape,
The base material layer forming step is a method for manufacturing the optical laminate in which a long base film and a long separator film are stacked by a roll-to-roll method through the adhesive layer.
(7) The method for manufacturing the optical layered body, wherein the optical functional layer forming step includes performing the step of irradiating the photocurable resin with light in a plurality of times.
(8) The said optical function layer formation process is a manufacturing method of the said optical laminated body provided with the step which irradiates light with respect to the said photocurable resin, and the step which heats the said photocurable resin.
(9) The method for producing the optical laminate, wherein at least one of the adhesive layer, the base film, and the optical functional layer is composed of a composition containing particles that impart light diffusibility.
(10) An optical laminate produced by the method for producing an optical laminate.

  In the optical laminate of the present invention, after forming an optical laminate substrate layer comprising a substrate film, an adhesive layer, and a separator film, the procedure for forming the optical functional layer causes problems such as curling. Since it does not occur easily, the adhesive layer can be provided smoothly, and the productivity of the optical laminate can be improved.

FIG. 1 is a longitudinal sectional view for explaining an optical laminate according to this embodiment. FIG. 2 is a flowchart for explaining the manufacturing method of the optical layered body. FIG. 3 is a longitudinal sectional view for explaining a display device using the optical laminate.

<Optical laminate>
An optical laminate according to an embodiment of the present invention will be described below.
FIG. 1 is a longitudinal sectional view for explaining an optical laminate according to this embodiment. As shown in FIG. 1, the optical laminate 40 is provided on the base film 42, the optical functional layer (uneven structure layer) 44 provided on the surface side of the base film 42, and the back surface side of the base film 42. An adhesive layer 46 and a separator film 48 provided on the back side of the adhesive layer 46 are provided.

  The base film 42 can be composed of a 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, and can have a total light transmittance of 80% or more.

  Examples of the transparent resin include thermoplastic resins, thermosetting resins, ultraviolet curable resins, and electron beam curable resins. Among these, a thermoplastic resin is preferable because it can be easily deformed by heat, and an ultraviolet curable resin is preferable because it has high curability and high efficiency, so that an uneven structure can be efficiently formed. Examples of the thermoplastic resin include polyester-based, polyacrylate-based, and cycloolefin polymer-based resins. Examples of the ultraviolet curable resin include epoxy-based, acrylic-based, urethane-based, ene / thiol-based, and isocyanate-based resins. As these resins, those having a plurality of polymerizable functional groups can be preferably used. In addition, as the ultraviolet curable resin, a resin that is cured by ultraviolet rays (or after being cured) and cured even when heated can be preferably used.

  The material of the base film 42 has a certain degree of flexibility when forming the concavo-convex structure layer 44 and / or for facilitating the handling of the optical laminate on which the concavo-convex structure layer 44 is formed. Is preferred.

  The base film 42 may be formed in a sheet shape (sheet shape), but may be formed in a long shape that can be wound around a roll or the like. When the base film 42 is formed in a long shape, it is preferable to form the separator film 48 in a long shape because the separator film 48 and the roll-to-roll method can be efficiently laminated. In the present invention, the long shape means a shape having a length in the length direction of 10 times or more with respect to the width direction. Moreover, the thickness of the base film 42 can be 20-300 micrometers, for example.

  The optical function layer 44 controls the direction of light incident from a light source (display device) disposed on the incident side of the base film 42, thereby improving the light extraction rate, eliminating color unevenness, improving luminance, etc. It is a layer for imparting the optical function. In the present embodiment, the optical functional layer 44 is configured as a concavo-convex structure layer 44 having a concavo-convex structure 50 formed on the surface thereof.

  The concavo-convex structure 50 includes a plurality of concave portions 52 including inclined surfaces, and a flat portion 54 that is located around the concave portions 52 and is formed in a planar shape so as to separate the adjacent concave portions 52. Each recessed part 54 is comprised as a hollow of a regular quadrangular pyramid shape. The plurality of recesses 54 are arranged in a state in which they face each other in the same direction. The apex angle of the regular quadrangular pyramid constituting each recess 54 can be 60 °. However, in the case where the optical laminate 40 is used by being attached to an organic EL element, from the viewpoint that the light extraction efficiency can be further increased while minimizing the color change due to the observation angle, the apex angle is The average is preferably 40 to 100 °.

The thickness of the concavo-convex structure layer 44 is not particularly limited, but can be 1 to 70 μm.
The thickness of the concavo-convex structure layer 44 is the distance between the surface on the substrate film 42 side and the most distal portion of the concavo-convex structure 50, that is, the distance between the flat portion 54 of the concavo-convex structure 50 in this embodiment.

  In the above embodiment, the concavo-convex structure layer is used as the optical functional layer. However, the present invention is not limited to this, and for example, a layered structure using a resin composition containing diffusible particles may be used. Furthermore, in the said embodiment, although it was set as the structure containing a recessed part and a flat part as the uneven structure 50 of the uneven structure layer 44, it is not limited to such a structure. For example, the concavo-convex structure 50 may have a configuration that does not include a flat portion or a configuration that has a convex portion instead of a concave portion. Further, the shape of the concavo-convex structure 50 can be a cone or a truncated cone other than a regular quadrangular pyramid, a hemisphere, a line shape, or the like.

  The material constituting the concavo-convex structure layer 44 is preferably a material having high hardness at the time of curing from the viewpoint of easily forming the concavo-convex structure on the surface (light-emitting surface) and easily obtaining scratch resistance of the concavo-convex structure. Specifically, when a resin layer having a film thickness of 7 μm is formed on a base film in a state where there is no uneven structure, a material that has a pencil hardness of HB or more is preferable, and a material that has H or more is further Preferably, the material which becomes 2H or more is more preferable. In the present invention, a photocurable resin is used as the material constituting the concavo-convex structure layer 44. In this case, an ultraviolet curable resin is preferable, and specifically, an epoxy system, an acrylic system, a urethane system, an ene / thiol system is used. And an isocyanate-based ultraviolet curable resin.

  Here, the refractive index difference between the base film 42 and the concavo-convex structure layer 44 is preferably as small as possible, the refractive index difference is preferably within 0.20, and more preferably within 0.05.

  The adhesive layer 46 can be appropriately used as an adhesive (including a pressure-sensitive adhesive) that is a constituent material, and having a refractive index close to that of the base film 42 and the concavo-convex structure layer 44 and being transparent. Specifically, examples of the adhesive include an acrylic adhesive (pressure-sensitive adhesive). The thickness of the adhesive layer 46 can be 5-100 micrometers, for example.

  The separator film 48 is a film that covers the adhesive layer 46 so as not to be exposed to the outside. The separator film 48 is a portion that is peeled off from the adhesive layer 46 when the optical laminated body 40 is attached to a display device. It does not specifically limit as a material which comprises the separator film 48, For example, the same material as the composition which comprises the base film 42 can be used. Among these, it is preferable to use polyester-based, polyacrylate-based, and cycloolefin polymer-based thermoplastic resins in terms of excellent productivity. The separator film 48 may be formed in a sheet shape (sheet shape), but can be formed in a long shape that can be wound around a roll or the like. The long shape is preferable because it can be efficiently laminated using the long base film 42 and the roll-to-roll method.

  Here, at least one of the base film 42, the adhesive layer 46, and the concavo-convex structure layer 44 is, in addition to the resin material, a material imparting light diffusibility, a degradation inhibitor such as a phenol-based or amine-based material, It can contain antistatic agents such as surfactants and siloxanes, and light-proofing agents such as triazoles and 2-hydroxybenzophenone. Examples of the material imparting diffusibility include a material containing particles and a material made of alloy resin that diffuses light by mixing two or more kinds of resins. From the viewpoint that the diffusibility can be easily adjusted, a material containing particles is preferable, and a resin composition containing particles is more preferable. By including a material that imparts diffusibility in this manner, for example, when the optical laminate according to the present embodiment is used by being attached to an organic EL element, the change in color depending on the observation angle of the organic EL element is reduced. It is advantageous in that a desired effect such as can be obtained.

  In the case where a material imparting light diffusibility is added to the adhesive layer 46, light is irradiated when the photocurable resin constituting the concavo-convex structure layer 44 is cured. The light that is diffused and reaches the photocurable resin may be reduced. However, when a relatively small amount of material is added, for example, when the adhesive layer has a relatively weak diffusing action such that the total light transmittance of the adhesive layer is 50% or more, further 70% or more, the arrival of light Has little effect on productivity.

  Moreover, the material which comprises the uneven | corrugated structure layer 44 may contain a pigment, a fluorescent material, a luminous material, etc. By including such a pigment, for example, when the optical laminate 40 is used by being attached to the surface of a light source device or the like made of an organic EL element, the average chromaticity when the light source device is turned on is changed. Thus, variations in chromaticity of the light emitting elements constituting the organic EL element can be compensated, and conversely, light source devices having different color temperatures can be obtained from the same light emitting element. As such a pigment, various known inorganic pigments, organic pigments, and the like can be used. As inorganic pigments, metal compounds such as metal oxides and metal complex salts are generally used. Specifically, metals such as iron, cobalt, aluminum, cadmium, lead, copper, titanium, magnesium, chromium, zinc, and antimony are used. Or an oxide of a composite metal. Organic pigments include diketopyrrolopyrrole, anthraquinone, azo, disazo, copper phthalocyanine, halogenated copper phthalocyanine, quinacridone, benzimidazolone, isoindolinone, dioxazine, and perylene. Among them, among them, in the case where the optical laminate 40 is used by being attached to the surface of a light source device composed of an organic EL element, the chromaticity (x, y) when the light source device is turned on is used. A pigment for reducing x, for example, a blue pigment such as copper phthalocyanine or indanthrone, can be used in particular. The pigment blended in the material constituting the concavo-convex structure layer 44 can be added, for example, in a volume ratio of about 0.1 to 5% with respect to the total amount of the material (composition). It is preferable to do. Moreover, the said fluorescent material and phosphorescent material mix | blended with the material which comprises the uneven | corrugated structure layer 44 can be added about 0.1 to 20% by volume ratio with respect to the said material (composition) whole quantity, for example.

  In addition, by including a fluorescent material in the material constituting the concavo-convex structure layer 44, for example, when the optical laminate 40 is used by being attached to the surface of a light source device or the like made of an organic EL element, the light source device Brightness can be further improved. In addition, by including a phosphorescent material in the material constituting the concavo-convex structure layer 44, for example, when the optical laminate 40 is used by being attached to the surface of a light source device or the like made of an organic EL element, the light source device Even when the light is turned off, the light-emitting surface is not instantly darkened by the action of the phosphorescent material, and the visibility is maintained for a while, so that the safety is high and it is suitable as a lighting device or the like.

  As described above, a pigment, a fluorescent material, and a phosphorescent material may be included in the material constituting the concavo-convex structure layer 44. However, the present invention is not limited to this. For example, the optical laminate 40 is a light source composed of an organic EL element. When pasted on the surface of an apparatus or the like, it may be included in any layer of the layers between the light emitting layer and the concavo-convex structure layer of the organic EL element.

  In addition, when adding compounding agents, such as a pigment, since it is not limited to the manufacturing method of this invention, the following invention can be mentioned as an invention relevant to this invention. That is, the invention related to the present invention is an optical film comprising a base film and an optical functional layer provided on the surface side of the base film, and either the base film or the optical functional layer is It is comprised by the composition containing a pigment, a fluorescent material, and / or a luminous material. Further, other inventions related to the present invention include a base film, an optical functional layer provided on the surface side of the base film, an adhesive layer provided on the back side of the base film, and the adhesive layer. And a separator film provided on the back side of the substrate, wherein at least one of the base film, the optical functional layer, and the adhesive layer includes a pigment, a fluorescent material, and / or a phosphorescent material It can be comprised by the thing. According to the above structure, each effect mentioned above which mix | blended each compounding agent can be acquired, and it is suitable also for a light source device and a display apparatus.

<Method for producing optical laminate>
Next, the manufacturing method of an optical laminated body is demonstrated.
FIG. 2 is a flowchart for explaining a method of manufacturing the optical laminate. As shown in FIG. 2, the elongate base film 42 manufactured by the melt extrusion method etc. is prepared. Further, a long separator film 48 obtained in the same manner as the base film 42 is prepared. Furthermore, the adhesive which comprises the contact bonding layer 46 which adhere | attaches the base film 42 and the separator film 48 is prepared (S1).

  In addition, a mold 60 having an uneven surface (shape imparting surface) 62 to which the shape of the uneven structure 50 is transferred is prepared (die preparing step: S2). As such a mold 60, for example, a metal mold, a resin mold, a ceramic mold, or the like can be used. The mold 60 can have a cylindrical shape or a flat plate shape having an uneven surface 62 on its surface, but is preferably a cylindrical shape from the viewpoint of improving productivity. The surface of the concavo-convex surface 62 may be subjected to a mold release treatment so that the molded body (concavo-convex structure layer) can be easily released. Thereby, generation | occurrence | production of the malfunction (crack) in the uneven structure layer 44 can be suppressed.

  Next, the said adhesive agent is continuously apply | coated to one side (back surface) of the elongate base film 42 so that it may become fixed thickness using a die coater etc. (application | coating step: S3). Next, the long separator film 48 is laminated by a roll-to-roll method on the surface (back surface) of the base film 42 on which the adhesive is applied to form the optical laminate base layer 41. (Lamination step: S4). Thus, a base material layer formation process is implemented.

  Next, the position of the mold 60 is adjusted so that a predetermined gap is provided between the base film 42 of the long optical laminate base layer 41 and the concavo-convex surface 62 of the cylindrical mold 60. Next, in the state adjusted in this way, the long optical laminate base material layer 41 is fed out, and the photocurable resin is continuously arranged on the other surface (surface) of the optical laminate base material layer 41. (Placement step: S5). Next, the concavo-convex surface 62 of the mold 60 is brought into contact with the photocurable resin disposed on the optical laminate base layer 41, and at this time, the gap is filled with the photocurable resin. (Contact step: S6). Thus, a resin arrangement | positioning process is implemented.

  Next, the photocurable resin is irradiated with light from the separator film 48 side of the optical laminate base material layer 41 to cure the photocurable resin, thereby forming the concavo-convex structure layer 44 (optical functional layer). Formation process: S7). In addition, although the step of irradiating light may be carried out once, it may be carried out in multiple steps by dividing it into a plurality of times by irradiating light after the mold release step (S8) described later. . Further, the photocurable resin may be further cured by performing heat treatment together with the light irradiation step or after the step. Note that the step of irradiating light can be performed by, for example, using a high pressure mercury lamp as a light source and using an ultraviolet curable resin as a photocurable resin and irradiating, for example, about 1 J of ultraviolet rays.

  Finally, the mold 60 is peeled off from the formed concavo-convex structure layer 44 (mold release step: S8) to obtain a long optical laminate 40, and the optical laminate 40 is wound into a roll. The optical laminated body 40 is obtained by the above process.

  When the adhesive layer 46 and the separator film 48 are provided after the uneven structure layer 44 is provided on the base film 42, the laminate is curled (warped) by the curing shrinkage of the photocurable resin constituting the uneven structure layer 44. Since this occurs, the subsequent process (formation of the adhesive layer and separator film) becomes difficult, resulting in a decrease in productivity, and cracks in the concavo-convex structure layer when wound in a roll shape. But there is a problem that it is inferior in productivity. On the other hand, after forming the optical laminate substrate layer 41 including the substrate film 42, the adhesive layer 46, and the separator film 48 as in the method for producing an optical laminate of the present invention, the concavo-convex structure layer is formed. By adopting the procedure for forming 44, since problems such as curl as described above are unlikely to occur, there is an advantage that the adhesive layer 46 can be provided smoothly and the productivity of the optical laminate can be further improved.

<Light source device using optical laminate>
Next, a light source device using the optical laminate 40 will be described.
FIG. 3 is a longitudinal sectional view illustrating a display device using the optical laminate according to the present embodiment. As shown in FIG. 3, the light source device 1 includes an organic EL element 20 and an optical laminate 40 that is disposed in contact with at least one surface of the organic EL element 20.

  The organic EL element 20 includes a first electrode layer 22 that constitutes a reflective electrode, a light emitting layer 24, a second electrode layer 26 that is a transparent electrode, and a glass substrate 28 in this order. A voltage is applied between the second electrode layer 26 and the second electrode layer 26 to cause the light-emitting layer 24 to emit light, which can be used as a light source. Such an organic EL element 20 can be used suitably for a lighting fixture, a display apparatus, etc. In addition to the light emitting layer 24, the organic EL element 20 includes a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection between the first electrode layer 22 and the second electrode layer 26 as necessary. Other layers such as layers and gas barrier layers can be provided. The organic EL element 20 can also include arbitrary components such as wiring for energizing the electrode layers 22 and 26 and a peripheral structure for sealing the light emitting layer.

The optical laminate 40 is provided on the surface of the glass substrate 28.
Specifically, the optical laminate 40 manufactured by the above method is prepared, the separator film 48 of the optical laminate 40 is peeled off to expose the adhesive layer 46, and the exposed adhesive layer 46 is applied to the surface of the glass substrate 28. Adhere to. In this way, the light source device 1 in which the optical laminate 40 is provided on the light emitting surface of the organic EL element 20 can be obtained. Such a light source device can be used for a lighting fixture, a backlight device, a display device, and the like.

<Modification>
The present invention is not limited to the embodiment.
In the embodiment, the light curable resin is cured by irradiating light from the separator film 48 side, but the light curable resin may be cured by irradiating light from the mold 60 side. In this case, it is preferable to use a resin mold as the mold 60. In addition, the mold is applied to the resin after the photocurable resin is provided on the base film. For example, after the photocurable resin is provided on the mold side, the base film is applied to the resin. May be.

  Moreover, in the said embodiment, when laminating | stacking the base film 42 and the separator film 48, after apply | coating the adhesive agent which comprises the adhesive layer 46 on the base film 42, it is separator with respect to this adhesive agent. Although the film 48 is applied, the double-sided adhesive film may be used instead of the adhesive.

  In the said embodiment, although the surface part of the organic EL element 20 was comprised by the glass substrate 28, you may use a resin-made board | substrate, in short, the material of a board | substrate is not limited to glass. Moreover, although the optical laminated body 40 was arrange | positioned directly on the surface of the glass substrate 28, other optical members, such as a polarizing plate (For example, a circularly-polarizing plate which has a polarizing plate and a quarter wavelength plate) on the surface of the glass substrate 28. And the optical laminate 40 may be disposed on the surface (light-emitting side) of the optical member. In short, the optical laminate 40 can be disposed directly or indirectly on the surface of the glass substrate 28.

  Hereinafter, based on an Example and a comparative example, it demonstrates still in detail about this invention. In addition, this invention is not limited to the following Example. The refractive index of the resin described below is the refractive index after curing.

<Example 1>
Double-sided adhesive film (manufactured by Nitto Denko Corporation) consisting of polyester base film (Toray Industries, Lumirror U34, thickness 100 μm) and acrylic adhesive with separators (release liner) on both sides CS9621), one of the separators of the double-sided adhesive film was peeled off, and laminated with the base film to obtain an optical laminate base layer.

  Further, a diffusing agent (silicone resin, n = 1.43), which is a spherical particle having an average particle diameter of 2 μm, is added to an ultraviolet curable resin (urethane acrylate resin, refractive index n = 1.54) in 10% of the total amount of the composition. % (Volume ratio) was added and stirred to disperse the particles to obtain Resin Composition A.

Next, after applying the resin composition to the base film side surface of the optical laminate base layer, a metal mold having a predetermined shape is pressed onto the coating film of the resin composition, and the optical laminate base Ultraviolet rays were irradiated from the layer side with an integrated light amount of 1000 mJ / cm ² to form an uneven structure layer on the base film. Next, the mold was removed from the ultraviolet curable resin to obtain an optical laminate X.

  The concavo-convex structure 50 includes a plurality of regular quadrangular pyramid-shaped concave portions and flat portions located around the concave portions. The angle formed by the inclined surface constituting the recess and the flat portion was 60 °. The length of the bottom side of the recess was 16 μm, and the interval between the recesses was 4 μm, which was a constant interval. The bottom side of the recess was parallel to the long side or short side direction of the optical laminate 40. The thickness of the concavo-convex structure layer 47 was 34 μm, and the thickness of the base film was 100 μm. The obtained optical laminate was cut into 10 cm squares and placed on a flat plate to confirm the distance from the flat plate at the four corners. As a result, the warp of the laminate was small, and the average was 3 mm or less.

<Example 2>
A silicone resin diffusing agent (refractive index 1.43, average particle diameter 2 μm, spherical) is composed of an adhesive made of acid-modified polyolefin resin (Cornova MPO-B130C, refractive index 1.49, manufactured by Nippon Cima). It added at 10% (volume ratio) in the total amount of the product, and stirred to disperse the particles, thereby obtaining a resin composition B.

  Next, the resin composition B was applied on the polyester base film with a thickness of 20 μm using a die coater. Next, a polyester separator film was laminated on the surface of the base film on which the adhesive was applied to obtain an optical laminate base material layer.

Next, after applying the resin composition A to the base film side surface of the optical laminate base layer, a metal mold having a predetermined shape is pressed onto the coating film of the resin composition A, and the optical laminate base Ultraviolet rays were irradiated from the material layer side with an integrated light amount of 300 mJ / cm ² to form an uneven structure layer on the base film. Next, the UV curable resin and the mold on which the concavo-convex structure is formed are peeled off, and this time, UV light is irradiated from the concavo-convex structure side with an integrated light amount of 700 mJ / cm ² , and heat treatment is further performed at 140 ° C. Body Y was obtained. The obtained optical laminate was cut into 10 cm squares and placed on a flat plate to confirm the distance from the flat plate at the four corners. As a result, the warp of the laminate was small, and the average was 3 mm or less.

<Example 3>
Next, 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 A 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 material forming each layer from the transparent electrode layer to the reflective electrode layer is as follows:
-Transparent electrode layer; tin-added indium oxide (ITO)
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

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.

  Further, a 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, and a surface light source device C was produced. The obtained surface light source device C had a rectangular light exit surface capable of emitting white light from the glass substrate side.

  Two surface light source devices thus obtained were prepared. The separator films of the optical laminates X and Y obtained in Examples 1 and 2 were peeled off, and each optical laminate was stuck on the glass substrate surface of the surface light source device C to obtain a surface light source device.

<Comparative Example 1>
After the resin composition A is applied on a polyester base film (Toray, Lumirror U34, thickness 100 um), a metal mold of a predetermined shape is pressed onto the coating film of the resin composition, and the base film Ultraviolet rays were irradiated from the side with an integrated light amount of 1000 mJ / cm ² to form an uneven structure layer on the base film. Next, the mold was peeled from the ultraviolet curable resin to obtain a base film having an uneven structure layer. For confirmation, this base film was cut into a 10 cm square and placed on a flat plate to check the distance from the flat plate at the four corners. As a result, the warp was large and the average was 10 mm. Next, an attempt was made to provide an adhesive layer on the surface of the obtained base film where the uneven structure layer was not formed, but the base film was warped (curl) based on curing shrinkage when the uneven structure was formed. As a result, the work became complicated and the workability was poor.

<Example 4>
An optical laminate was obtained in the same manner as in Example 1 except that the following resin composition D was used instead of the resin composition A used in Example 1, and an example using this optical laminate was obtained. In the same manner as in Example 3, a surface light source device was obtained. Resin composition D is an ultraviolet curable resin (urethane acrylate resin, refractive index n = 1.54) and a diffusing agent (silicone resin, n = 1.43) which is a spherical particle having an average particle diameter of 2 μm. Add 10% (volume ratio) of the total amount, and further add a pigment (Orvein Kogyo Co., Ltd., Oriental Blue) at 0.4% (volume ratio) of the total composition, and stir to disperse the particles and pigment. Made. When the front chromaticity of the obtained surface light source device was measured, the front chromaticity (x, y) when not added = (0.295, 0.334) was obtained, whereas the surface light source of Reference Example 1 was used. It was found that the front chromaticity (x, y) = (0.254, 0.321) of the apparatus was converted into the blue direction. Therefore, it has been found that elements having various color temperatures can be manufactured using one light emitting element. The obtained optical laminate was cut into a 10 cm square and placed on a flat plate to confirm the distance from the flat plate at the four corners. As a result, the warp of the laminate was small, and the average was 3 mm or less.

<Example 5>
An optical laminate was obtained in the same manner as in Example 1 except that the following resin composition E was used instead of the resin composition A used in Example 1, and an example using this optical laminate was obtained. In the same manner as in Example 3, a surface light source device was obtained. Resin composition E is a composition comprising a UV curable resin (urethane acrylate resin, refractive index n = 1.54) and a diffusing agent (silicone resin, n = 1.43) which is a spherical particle having an average particle diameter of 2 μm. It was added at 10% (volume ratio) in the total amount, and further, fluorescent material (manufactured by Intematix, Y4254) was added at 9% (volume ratio) in the total amount of the composition and stirred to disperse the particles and pigment. . When the front chromaticity of the obtained surface light source device was measured, the front chromaticity when not added (x, y) = (0.295, 0.335), whereas the surface light source of Reference Example 2 was obtained. The front chromaticity of the device (x, y) = (0.292, 0.357), and it can be seen that the front chromaticity has been converted to the green direction. For this reason, the brightness of the surface light source device is increased compared to the conventional case. I was able to. The obtained optical laminate was cut into a 10 cm square and placed on a flat plate to confirm the distance from the flat plate at the four corners. As a result, the warp of the laminate was small, and the average was 3 mm or less.

<Example 6>
An optical laminate was obtained in the same manner as in Example 1 except that the following resin composition F was used instead of the resin composition A used in Example 1, and an example using this optical laminate was obtained. In the same manner as in Example 3, a surface light source device was obtained. Resin composition F is a composition in which UV curable resin (urethane acrylate resin, refractive index n = 1.54) is added with a diffusing agent (silicone resin, n = 1.43) which is spherical particles having an average particle diameter of 2 μm. Add 10% (volume ratio) of the total amount, and add a phosphorescent material (Kamibright, main component; strontium oxide) at 9% (volume ratio) of the total composition, and stir to disperse the particles and pigment. Produced. When the obtained surface light source device was turned off, it was confirmed that light was emitted in light green for a while after the light was turned off. The obtained optical laminate was cut into a 10 cm square and placed on a flat plate to confirm the distance from the flat plate at the four corners. As a result, the warp of the laminate was small, and the average was 3 mm or less.

  As shown in Examples 1 to 6, by forming the concavo-convex structure layer after providing the adhesive layer and the separator film, the optical laminate base material layer is not warped and the influence on subsequent processes is suppressed. I was able to. On the other hand, as shown in Comparative Example 1, when the concavo-convex structure layer is formed on the base film before providing the adhesive layer and the separator film, the base film is warped and the subsequent steps are greatly increased. It was found that it has a significant effect.

DESCRIPTION OF SYMBOLS 1 Light source device 20 Organic EL element 22 1st electrode layer 24 Light emitting layer 26 2nd electrode layer 28 Glass substrate 40, X, Y Optical laminated body 41 Optical laminated body base material layer 42 Base film 44 Uneven structure layer (optical Functional layer)
46 Adhesive layer 48 Separator film 50 Concavity and convexity structure 52 Concavity 54 Flat portion 60 Mold 62 Concavity and convexity (shape imparting surface)
A, B resin composition

Claims (4)

A base film;
An optical functional layer having a concavo-convex structure made of a photocurable resin, provided on the surface side of the base film;
It has an adhesive layer provided on the back side of the substrate film, and is an optical laminate for sticking to the surface of an organic electroluminescence element,
Any one of the base film, the optical functional layer, and the adhesive layer is an optical laminate including a composition containing a pigment, a fluorescent material, and / or a phosphorescent material. The uneven structure is
The optical laminate according to claim 1, comprising a cone, frustum, hemisphere, or linear shape.   The optical laminated body according to claim 1 or 2, wherein the optical functional layer contains the pigment, and the content ratio of the pigment in the optical functional layer is 0.1 to 5% by volume.   The optical functional layer includes the fluorescent material or the phosphorescent material, and the content ratio of the fluorescent material or the phosphorescent material in the optical functional layer is 0.1 to 20% by volume. The optical laminate according to claim 1.

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