JP2019006080A - Light emitter protective film, wavelength conversion sheet, backlight unit, and electroluminescent light emitting unit - Google Patents

Abstract

To provide a light emitter protective film capable of forming a light emitter layer uniformly without unevenness, when used in a wavelength conversion sheet or a light emitting unit, preventing performance deterioration as a fluorescent body or a light emitter due to lowered gas barrier properties, and preventing an occurrence of a dark spot.SOLUTION: A light emitter protective film composes a part of an electroluminescent unit or a wavelength conversion sheet. The light emitter protective film protects a fluorescent body layer of the wavelength conversion sheet or a light emitter layer of the electroluminescent unit and includes an auxiliary film with a thickness of 50 μm or more and including a gas barrier film and a polyester film. The auxiliary film is formed between the gas barrier film and the fluorescent body layer or the light emitter layer.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a light emitter protective film, a wavelength conversion sheet, a backlight unit, and an electroluminescence light emitting unit.

  Each of the backlight unit or the electroluminescence light emitting unit of the liquid crystal display includes a phosphor including quantum dots or the like in the wavelength conversion sheet of the backlight unit as a light emitting unit, and the electroluminescence light emitting unit includes an electroluminescence light emitting unit. The wavelength conversion sheet is a sheet for converting a part of the light from the light source of the backlight unit.

  When the phosphor or illuminant comes into contact with oxygen or water vapor or the like in the air atmosphere for a long time, the performance as the phosphor or illuminant may be deteriorated. For this reason, a gas barrier film in which a gas barrier layer is formed on a polymer film substrate is often used as a protective film for phosphors and light emitters in the wavelength conversion sheet and the electroluminescence light emitting unit (see, for example, Patent Document 1). ).

  Hereinafter, unless otherwise distinguished in the present application, the phosphor and the light emitter may be collectively referred to as a light emitter, and the phosphor layer and the light emitter layer may be collectively referred to as a light emitter layer.

  In FIG. 10, the form of the light-emitting body protective film 70 which formed the gas barrier layer 72 in the polymer film base material 71 as mentioned above is shown. In FIG. 11, the form of the wavelength conversion sheet | seat 80 which uses the light-emitting body protective film 70 is shown. As described above, the wavelength conversion sheet 80 has a structure in which the light emitter layer 73 is sandwiched (that is, sealed) between the light emitter protective film 70 and 70 ′ in which 70 is turned upside down.

  The luminous body protective film 70 is usually manufactured by a roll-to-roll method. After producing the 1st, 2nd roll of the light-emitting body protective film 70 which formed the gas barrier layer 72 on the polymer film base material 1, the wavelength conversion sheet 80 is further manufactured by a roll to roll system. That is, first, a 1st roll and a 2nd roll are arrange | positioned so that the surface by the side of the gas barrier layer of each light-emitting body protective film may oppose. On the other hand, a sealing resin, a light emitter and, if necessary, a solvent are mixed to prepare a light emitter layer coating liquid.

  Next, the phosphor layer coating liquid is applied to the gas barrier layer side surface of the phosphor protective film of one of the first and second rolls to form a phosphor layer, and this surface and the other roll The surface on the gas barrier layer side of the luminous body protective film is bonded. At this time, when the sealing resin is a photosensitive resin / thermosetting resin, the resin is cured by ultraviolet irradiation / heating. After that, the wavelength conversion sheet 80 is obtained by cutting the laminated body to a predetermined size.

  However, in the formation of the light emitter protective film, due to the thermal load and tension in the process of forming the gas barrier layer, the light emitter protective film is easily distorted in the flow direction of the roll-to-roll process, resulting in fine wrinkles. Therefore, when forming the light emitter layer, the fine wrinkle shape of the light emitter protective film is affected, and coating unevenness may occur in the light emitter layer.

  In particular, depending on the viscosity of the phosphor layer coating liquid and the coating method, fine wrinkles of the phosphor protective film are further increased in the flow direction of the roll-to-roll process due to the tension during coating, and the phosphor along the flow direction. The coating unevenness of the layer becomes large. As a result of such coating unevenness, the adhesion between the illuminator protective film and the illuminant layer is lowered, and thus the gas barrier property is lowered, which causes a decrease in luminance over time.

  Furthermore, when a local fine defect occurs due to rusting or scratching in the gas barrier layer of the light emitter protective film, a light emitting defect, that is, a black spot-like defect called a dark spot (non-light emitting region) is located near the defect. May occur. A dark spot is a light emission failure that occurs in the light emitting layer with a size equivalent to a minute defect. Such a micro defect of the gas gallium layer hardly appears in the gas barrier property of the light emitter protective film evaluated by measurement of gas permeability or the like, but appears as occurrence of a dark spot.

  Also in the electroluminescence light emitting unit, it is conceivable that dark spots are generated by the same mechanism as that described for the wavelength conversion sheet. Each electrode layer, light emitter layer, and dielectric layer in the electroluminescence light emitting unit are formed by vapor deposition, sputtering, or the like. If wrinkles, scratches, etc. are present in the light emitter protective film, each electrode layer, light emitter The layer and the dielectric layer cannot be formed smoothly and without defect, and the performance of the electroluminescence light emitting unit is deteriorated.

International Publication No. 2015/013225

  The present invention has been made in view of the above problems, and when used in a wavelength conversion sheet or an electroluminescent light emitting unit, it is possible to uniformly form a light emitter layer without unevenness, and hence a reduction in gas barrier properties. An object of the present invention is to provide a phosphor protective film, a wavelength conversion sheet, a backlight unit, and an electroluminescence light emitting unit capable of suppressing degradation of the performance as a phosphor or a light emitter due to the above, and suppressing the occurrence of dark spots. To do.

In order to solve the above problem, the invention according to claim 1 is a light emission that forms part of the wavelength conversion sheet or the electroluminescence unit and protects the phosphor layer of the wavelength conversion sheet or the phosphor layer of the electroluminescence unit. A body protection film,
A gas barrier film, and an auxiliary film made of a polyester film and having a thickness of 50 μm or more,
The auxiliary film is a light emitter protective film formed between the gas barrier film and the phosphor layer or the light emitter layer.

Invention of Claim 2 consists of the base material which the said gas barrier film consists of a polyester film, an anchor coat layer, and a gas barrier film layer,
The gas barrier film layer includes an inorganic thin film layer made of an inorganic compound, and a composite film layer made of a composition containing at least one of a hydroxyl group-containing polymer compound, a metal alkoxide, a silane coupling agent, or a hydrolyzate thereof. It is set as the light-emitting-body protective film of Claim 1 characterized by becoming.

In the invention according to claim 3, the gas barrier film and the auxiliary film are bonded together via an auxiliary film adhesive layer,
Adhesive forming the auxiliary film adhesive layer, the thickness of 5 [mu] m, an oxygen permeability of 1000 cm ³ /
It is set as the light-emitting-body protective film of Claim 1 or 2 characterized by being below (m < ² > * day * atm).

  The invention according to claim 4 is characterized in that the gas barrier film and the auxiliary film are bonded so that the gas barrier film layer and the auxiliary film adhesive layer are in contact with each other. This is a light emitter protective film.

  The invention according to claim 5 is the light emitter protective film according to claim 3 or 4, wherein the adhesive is an adhesive containing an epoxy resin.

  The invention according to claim 6 is the light emitter protective film according to any one of claims 1 to 5, wherein the auxiliary film has a total light transmittance of 88% or more.

  The light-emitting device according to claim 7, wherein a coating layer formed integrally with the auxiliary film is provided on one side or both sides of the auxiliary film. It is a body protective film.

  The invention according to claim 8 is characterized in that an adhesion coating layer containing a silane coupling agent is provided on a surface of the auxiliary film that is in contact with the phosphor layer or the phosphor layer. It is set as the light-emitting body protective film in any one.

  The invention according to claim 9 is the light emitter protective film according to any one of claims 2 to 9, wherein the base material comprising the polyester film of the gas barrier film has hydrolysis resistance. It is.

  The invention according to claim 10 is characterized in that the gas barrier film is formed by bonding the two gas barrier films through a barrier film adhesive layer so that the composite coating layers face each other. 10 to 10.

  According to an eleventh aspect of the present invention, the phosphor layer includes a resin and a phosphor, and the phosphor protective film according to any one of the first to tenth aspects is laminated on both surfaces of the phosphor layer. This is a characteristic wavelength conversion sheet.

  The invention described in claim 12 is a backlight unit comprising a light source, a light guide plate, a reflecting plate, and the wavelength conversion sheet described in claim 11.

  Invention of Claim 13 is equipped with the electroluminescent light-emitting body layer, The light-emitting body protective film in any one of Claims 1-10 is laminated | stacked on both surfaces of the said electroluminescent light-emitting body layer, It is characterized by the above-mentioned. This is an electroluminescence light emitting unit.

According to the phosphor protective film of the present invention, when the phosphor protective film is coated on the phosphor protective film, the coating is not performed on the polyester auxiliary film having a thickness of 50 μm or more, but on the gas barrier layer, so that there is no unevenness. A light emitting layer can be formed uniformly. Furthermore, by using an adhesive having a barrier property for bonding the gas barrier film layer and the polyester-based auxiliary film, it is possible to fill fine defects generated in the gas barrier film layer with the adhesive. As described above, the phosphor protective film, the wavelength conversion sheet, the backlight unit, and the electroluminescence emission that can suppress the deterioration of the performance as the phosphor or the phosphor due to the gas barrier property and further suppress the generation of dark spots. Unit is obtained.

It is a schematic cross section of the light emitter protective film of the first embodiment of the present invention. It is a schematic cross section of the wavelength conversion sheet (there is no mat layer) using the luminous body protection film of a 1st embodiment of the present invention. It is a schematic cross section of a wavelength conversion sheet (with a mat layer) using the light emitter protective film of the first embodiment of the present invention. It is a schematic cross section of the light emitter protective film of the second embodiment of the present invention. It is a schematic cross section of the wavelength conversion sheet (with a mat layer) using the light emitter protective film of the second embodiment of the present invention. It is a schematic cross section of the backlight unit obtained using the wavelength conversion sheet of the present invention. It is a schematic cross section of the electroluminescent light emission unit obtained using the light-emitting body protective film of this invention. 4 is a schematic cross-sectional view of a light emitter protective film produced in Comparative Example 1. FIG. 3 is a schematic cross-sectional view of a wavelength conversion sheet produced in Comparative Example 1. FIG. It is a schematic cross section of the conventional light-emitting body protective film. It is a schematic cross section of the conventional wavelength conversion sheet | seat using the light-emitting body protective film of FIG.

  Hereinafter, a light emitter protective film, a wavelength conversion sheet, a backlight unit, and an electroluminescence light emitting unit according to an embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected about the same component unless there is a reason for convenience, and the overlapping description is abbreviate | omitted. In each drawing, the thicknesses and ratios of the constituent elements may be exaggerated for ease of viewing, and the number of constituent elements may be reduced. Moreover, it is not limited to the following embodiment in the range which does not deviate from the meaning of this invention.

  The light emitter protective film of the present invention can be used in common for the wavelength conversion sheet and the electroluminescence light emitting unit, but the description relating to the light emitter protective film is representatively performed when used for the wavelength conversion sheet.

  FIG. 2 is a schematic cross-sectional view of a wavelength conversion sheet 30a using the light emitter protection film 20a of the first embodiment of the present invention. The wavelength conversion sheet 30a includes a phosphor layer 21 formed on the phosphor protective film 20a, and a phosphor protective film 20a ′ provided on the phosphor layer 21 and upside down of the phosphor protective film 20a. It is configured. That is, the wavelength conversion sheet 30a has a structure in which the phosphor layer 21 is sandwiched (that is, sealed) between the two light emitter protection films 20a and 20a '.

[Light Emitter Protective Film According to First Embodiment]
The luminous body protective film 20a is a film that forms a part of the wavelength conversion sheet 30a and protects the phosphor layer 21 of the wavelength conversion sheet 30a, and is an auxiliary that is made of a gas barrier film 10a and a polyester film and has a thickness of 50 μm or more. The polyester auxiliary film 12 is formed between the gas barrier film 10 a and the phosphor layer 21. Since the phosphor protective film 20a includes the polyester-based auxiliary film 12, the phosphor layer 21 can be uniformly formed by applying the phosphor layer coating liquid to the polyester-based auxiliary film 12.

  In order to apply the phosphor layer coating liquid without being affected by the distortion of the gas barrier film 10a or the shape of wrinkles, the polyester-based auxiliary film 12 needs to have a thickness of 50 μm or more. The maximum thickness of the polyester-based auxiliary film 12 is not particularly limited, but 500 μm or more is not preferable because it often does not meet the product price.

If there is a polyester-based auxiliary film 12 having a thickness of 50 μm or more between the gas barrier film 10a and the phosphor layer 21, there is a concern that gas may enter from the end face of the polyester-based auxiliary film 12, but generally the barrier property of the polyester film Is about 1 cm ³ / (m ² · day · atm) (23 ° C., 70% RH environment) at a gas permeability of 1 mm, and therefore, the gas permeability inside the end face by 1 mm or more is 1 cm ³ / (m ² · day · atm) or less, and there is almost no influence by the invasion of gas from the end of the polyester film auxiliary membrane 12.

  FIG. 1 is a schematic cross-sectional view illustrating only the light emitter protection film 20a according to the first embodiment of the present invention. Here, the gas barrier film 10a is preferably composed of a base material 1 made of a polyester film, an anchor coat layer 2, and a gas barrier film layer 34, and the gas barrier film layer 34 is made of an inorganic thin film layer 3 made of an inorganic compound, It consists of a composite coating layer 4 made of a composition containing at least one of a hydroxyl group-containing polymer compound, a metal alkoxide, a silane coupling agent or a hydrolyzate thereof. In FIG. 1, the layer order in the gas barrier coating layer 34 is the order of the inorganic thin film layer 3 and the composite coating layer 4 from the side close to the polyester film substrate 1, but the reverse layer order may be used.

In the light emitter protection film 20 a, the gas barrier film 10 a and the polyester-based auxiliary film 12 are bonded together via the auxiliary film adhesive layer 11. The oxygen permeability of the auxiliary film adhesive layer 11 is preferably 1000 cm ³ / (m ² · day · atm) or less in the thickness direction at a thickness of 5 μm. Furthermore, it is preferably 500 cm ³ / (m ² · day · atm) or less, more preferably 100 cm ³ / (m ² · day · atm) or less, and 50 cm ³ / (m ² · day · atm). More preferably, it is more preferably 10 cm ³ / (m ² · day · atm) or less.

When the oxygen permeability of the auxiliary film adhesive layer 11 is 1000 cm ³ / (m ² · day · atm) or less at a thickness of 5 μm, gas may enter from the end face of the auxiliary film adhesive layer 11 in the lateral direction. And does not affect the phosphor.

  In the light emitter protection film 20a, the gas barrier film 10a and the polyester-based auxiliary film 12 are bonded together via the auxiliary film adhesive layer 11, but not the polyester film substrate 1 and the gas barrier film 10a as shown in FIG. It is desirable that the gas barrier film layer 34 and the auxiliary film adhesive layer 11 are bonded together so that the defects of the gas barrier film layer 34 are filled with the auxiliary film adhesive layer 11.

That is, when the auxiliary film adhesive layer 11 having an oxygen permeability of 1000 cm ³ / (m ² · day · atm) or less is in contact with the gas barrier film layer 34 of the gas barrier film, the gas barrier film layer 34 has a defect. Even so, dark spots can be suppressed by filling the defects with the auxiliary film adhesive layer 11. The lower limit of the oxygen permeability is not particularly limited, but is preferably 0.1 cm ³ / (m ² · day · atm).

  Examples of the auxiliary film adhesive layer 11 include acrylic adhesives, epoxy adhesives, urethane adhesives, and the like, and it is preferable to include an epoxy resin. Adhesiveness can be improved by including an epoxy resin in the adhesive.

  The thickness of the auxiliary film adhesive layer 11 is preferably 0.5 to 50 μm, more preferably 1 to 20 μm, and further preferably 2 to 6 μm. Adhesiveness is easily obtained when the thickness of the auxiliary film adhesive layer 11 is 0.5 μm or more, and excellent gas barrier properties are easily obtained when the thickness is 50 μm or less.

  The polyester auxiliary film 12 should have high transparency in consideration of the optical suitability of the light emitter protective film. If a film having a total light transmittance (conforming to JIS K-7105) of 88% or more is used as the polyester-based auxiliary film 12 having a thickness of 50 μm or more, the optical suitability of the light emitter is not impaired.

  It is preferable that there is a coat layer (not shown) formed integrally with the polyester auxiliary film 12 on one or both sides of the polyester auxiliary film 12. In general, since a polyester film having high transparency contains almost no filler, the slipperiness is poor and the processability may be lowered. Therefore, there is a method of providing an easy slip layer in order to impart slipperiness. When the polyester film is formed, the easy-sliding layer is manufactured by applying a coating liquid in which a lubricant having a size of several tens to several hundreds of nm is dispersed in a resin and stretching the polyester film integrally with the polyester film. The resin used for the easy-sliding layer is also effective in the adhesion with the light emitting layer, and further in the adhesion with the auxiliary film adhesive layer 11. Therefore, it is preferable that there are coat layers formed on the both sides of the polyester-based auxiliary film 12 so as to be integrally stretched with the polyester-based auxiliary film 12 as an easy-slip layer.

Various resins such as polyester, acrylic, polyurethane, and acrylic graft polyester can be appropriately used as a resin for applying and forming a coat layer that is integrally stretched with the polyester-based auxiliary film 12. The coating layer is formed by applying an in-line coating solution to an unstretched or uniaxially stretched polyester film, drying it, stretching it at least in a uniaxial direction, and then performing a heat treatment. The thickness of the coat layer is preferably 10 to 100 nm, and the coating amount after drying is preferably 0.01 to 0.1 g / m ² .

  Further, even if an adhesion coating layer containing a silane coupling agent is provided on the side of the polyester-based auxiliary film 12 in contact with the phosphor layer 21, the adhesion with the phosphor layer 21 can be improved.

[Wavelength conversion sheet]
A method for producing the wavelength conversion sheet of the present invention will be described. It does not specifically limit as a formation method of the fluorescent substance layer 21, For example, the method described in Japanese translations of PCT publication No. 2013-544018 is mentioned. A phosphor is dispersed in a binder resin, and the prepared phosphor dispersion is applied on the surface of the phosphor protective film 20a (see FIG. 2), and then the phosphor protective film 20a is turned upside down on the coated surface. The wavelength conversion sheet 30a can be manufactured by bonding 20a ′ and curing the phosphor layer 21 with light or heat.

  FIG. 3 is a schematic cross-sectional view of a wavelength conversion sheet (with a mat layer) using the light emitter protective film of the first embodiment of the present invention. The wavelength conversion sheet 30a in FIG. 2 may be in the form of 30am having a mat layer M that scatters light on the outer surface of the polyester film substrate 1 as shown in FIG. 3 in order to exhibit a light scattering function. When the wavelength conversion sheet 30am includes the mat layer M, an interference fringe (moire) prevention function, an antireflection function, and the like can be provided in addition to the light scattering function.

[Light Emitter Protective Film According to Second Embodiment]
FIG. 4 is a schematic cross-sectional view of the light emitter protection film 20b according to the second embodiment of the present invention. In the light emitter protection film 20b, the gas barrier film 10b is formed such that the gas barrier film 10a of FIG. 1 and 10a ′ obtained by inverting the top and bottom of 10a are opposed to each other through the barrier film adhesive layer 5. It has a laminated structure. By using two gas barrier films in this way, the barrier performance is improved, and the film is used even in a protective film for a luminescent material that is extremely vulnerable to the influence of gas from the atmosphere such as oxygen and water vapor, or in an environment where a harsh luminescent material is used. be able to.

  Also for the phosphor protective film 20b according to the second embodiment of the present invention shown in FIG. 4, the phosphor protective film 20b and the phosphor protective film 20b ′ obtained by inverting the phosphor protective film 20b up and down are arranged via the phosphor layer 21. The wavelength conversion sheet 30b (see FIG. 5) can be produced by bonding together and curing the phosphor layer 21 with light or heat.

  FIG. 5 is a schematic cross-sectional view of a wavelength conversion sheet (with a mat layer) using the light emitter protective film according to the second embodiment of the present invention. Thus, it can be set as the form of 30bm which provided the mat | matte layer M on the outer surface of the polyester film base material 1, and can provide a light-scattering function, an interference fringe (moire) prevention function, an antireflection function, etc.

(Phosphor layer)
The phosphor layer 21 contains a resin and a phosphor, and the thickness of the phosphor layer 21 is several tens to several hundreds μm. As the resin, for example, a photocurable resin or a thermosetting resin can be used. The phosphor layer 21 preferably includes two types of phosphors having different fluorescent colors made of quantum dots.

  Further, the phosphor layer 21 may be a laminate in which two or more phosphor layers containing one kind of phosphor and another kind of phosphor are laminated. Two types of phosphors having the same excitation wavelength are selected. The excitation wavelength is selected based on the wavelength of light emitted from the light source of the backlight unit. When a blue light emitting diode (blue LED) is used as the light source, the fluorescent colors of the two types of phosphors are red and green. The wavelength of each fluorescence and the wavelength of light emitted from the light source are selected based on the spectral characteristics of the color filter. The peak wavelength of fluorescence is, for example, 610 nm for red and 550 nm for green.

  Next, the particle structure of the phosphor will be described. As the phosphor, a core-shell type quantum dot having particularly good luminous efficiency is preferably used. The core-shell type quantum dot is obtained by covering a semiconductor crystal core as a light emitting portion with a shell as a protective film. For example, cadmium selenide (CdSe) can be used for the core and zinc sulfide (ZnS) can be used for the shell. The surface yield of CdSe particles is covered with ZnS having a large band gap, so that the quantum yield is improved. Further, the phosphor may be one in which the core is doubly covered with the first shell and the second shell. In this case, CdSe can be used for the core, zinc selenide (ZnSe) can be used for the first shell, and ZnS can be used for the second shell.

  The phosphor layer 21 may have a single layer configuration in which all the phosphors are dispersed in a single layer, and has a multilayer configuration in which each phosphor is separately dispersed in a plurality of layers and laminated. You may do it.

  Hereinafter, each layer of the polyester film base material 1, the anchor coating layer 2, the inorganic thin film layer 3, and the composite coating layer 4 constituting the gas barrier film 10a of the light emitter protection film 20a (see FIG. 2) will be described in order.

(Polyester film substrate 1)
It is more preferable that the polyester film substrate 1 has higher hydrolysis resistance. Due to the high hydrolysis resistance of the polyester film substrate 1, it is difficult to deteriorate due to hydrolysis, and there is an effect that adhesion strength and barrier properties are not deteriorated.

In order to improve hydrolysis resistance, a polyester resin composition having a reduced concentration of terminal carboxyl groups is used. The concentration of the terminal carboxyl group in the polyester is measured by the method described in the literature (ANALYTICAL CHEMISTRY, Vol. 26, page 1614). The terminal carboxyl group concentration measured by this method is 30 equivalents / 10 ^6. If the number average molecular weight of the polyester film base material measured by g permeation chromatography (GPC) is 60,000 or more, hydrolysis is unlikely to occur.

  In order to reduce the terminal carboxyl group of polyester, it is effective to mix and react an epoxy compound with the polyester resin composition which comprises the said polyester film base material.

  The epoxy compound is ethylene oxide, 1,2-propylene oxide, 1.2-butylene oxide, ebicoulehydrin, glycidol, methyl glycidyl ether, ethyl glycidyl ether, butyl glycidyl ether, allyl glycidyl ether, 2-ethylhexyl. Glycidyl ether, phenyl glycidyl ether, epoxidized soybean oil, epoxidized linseed oil, diethylene glycol diglycidyl ether, polyethylene glyfur diglycidyl ether, dipropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycewar triglycidyl ether, tri Methylolpropane triglycidyl ether, vinyl thiophene, di-sicpentadiene dioxide, 1 2-epoxy cyclo decane, include bisphenol A diglycidyl ether, using these compounds as appropriate, it is preferable to react by mixing one or more kinds.

  It is also effective to mix and react carbodiimide compounds. The carbodiimide compound includes N, N = -di-p-triylcarbodiimide, N, N = -diphenylcarbodiimide, N, N "-dioctyldecylcarbodiimide, N, N" -di-2,6-cycylphenylcarbodiimide, N-triyl-N'-cyclohexylcarbodiimide, N, N = -Gee 2 ° 6-diethylpropyl carbodiimide, N, N-Gee 2,6-seat tert, -butylphenylcarbodiimide, N- Triyl-N-phenylcarbodiimide, N, N-di-p-nitrophenylcarbodiimide, N, N-di-p-aminophenylcarbodiimide, N, N-di-p-hydroxyphenylcarbodiimide, N, N = -Di-cyclohexylcarbodiimide, N, N = -di-p-triylcarbodiimide, p-phenylene -Bisuji ○ -triylcarbodiimide, p-phenylene-bis-dicyclohexylcarbodiimide, hexamethylene-bis-dicyclohexylcarbodiimide, ethylene-bis-diphenylcarbodiimide, etc. Or you may make it react by mixing 2 or more types, and may mix with the above-mentioned epoxy compound.

  As a method for producing a polyester resin composition, there are a method of adding an epoxy compound or a carbodiimide compound to a melted polyester and stirring and reacting, or a method of kneading and reacting with an extruder or the like. If necessary, the composition may include various inorganic particles such as titanium oxide, silicon oxide, calcium carbonate, silicon nitride, clay, talc, kaolin, and zirconium acid, crosslinked polymer particles, and various metal particles. In addition to these, conventional antioxidants, sequestering agents, ion exchange agents, anti-coloring agents, light-proofing agents, inclusion compounds, antistatic agents, various coloring agents, waxes, silicone oils, and various fluorine compounds are added. May be. An easy-adhesion layer (not shown) may be provided on the surface of the polyester film substrate 1 on which the anchor coat layer 2 will be formed later by an in-line coating method. Since the polyester film substrate 1 and the anchor coat layer 2 are mixed together by the easy adhesion layer, it is difficult to peel off the surface layer at the interface.

  The thickness of the polyester film substrate 1 is not particularly limited, but is preferably 3 μm or more and 100 μm or less, and more preferably 5 μm or more and 50 μm or less.

(Anchor coat layer 2)
Next, the anchor coat layer 2 will be described. This layer is formed not only for improving the adhesion between the polyester film substrate 1 and the inorganic thin film layer 3 but also for the purpose of uniformly forming the thin inorganic thin film layer 3 to express a high barrier property. is there.

  The constituent material of the anchor coat layer 2 needs to contain a urethane bond having higher hydrolysis resistance than an ester bond. Thereby, the adhesion between the isocyanate component contained in the material of the easy-adhesion layer and the anchor coat layer 2 is improved, and the water resistance is improved. A urethane bond is a bond formed by an addition reaction between an isocyanate and an alcohol. In particular, a two-component reaction between a compound having a hydroxyl group such as polyurethane polyol, polyester polyol, polyether polyol, and acrylic polyol and an isocyanate compound having an isocyanate group. The anchor coat layer 2 made of a composite is preferable because it not only has good adhesion, but also can form a smooth film and uniformly form the inorganic thin film layer 3.

  As a method for forming the anchor coat layer 2, for example, a known printing method such as an offset printing method, a gravure printing method, a silk screen printing method, or a known coating method such as a roll coating, a knife edge coating, or a gravure coating is used. Can do. About drying conditions, generally used conditions may be used. Moreover, in order to accelerate | stimulate reaction, you may use the method of leaving it to stand for several days in a high temperature aging chamber etc.

(Inorganic thin film layer 3)
Next, the inorganic thin film layer 3 will be described. The inorganic thin film layer 3 contains a metal oxide, and examples of the metal oxide include oxides of metals such as aluminum, copper, silver, yttrium, tantalum, silicon, and magnesium. Since the metal oxide is inexpensive and excellent in barrier performance, it is preferably silicon oxide (SiO _x , x is 1.0 to 2.0). When x is 1.0 or more, good gas barrier properties tend to be obtained.

  The method for forming the inorganic thin film layer 3 is preferably vacuum film formation. Examples of vacuum film formation include physical vapor deposition and chemical vapor deposition. Examples of physical vapor deposition include vapor deposition, sputtering, and ion plating. Examples of the chemical vapor deposition method include a thermal CVD method, a plasma CVD method, and a photo CVD method.

  From the viewpoint of manufacturing cost, the inorganic thin film layer 3 formed by a vapor deposition method is preferable. In the vapor deposition method, for example, holes may be formed in the gas barrier film due to splashing of the vapor deposition material. Although the frequency of occurrence of splash is small, the holes generated by the splash are relatively large defects and can be holes that penetrate the gas barrier coating layer and the substrate. Therefore, in the protective film in which the holes due to the splash are generated, the gas barrier property is greatly lowered. Moreover, when a hole arises in the gas barrier film arrange | positioned at the light-emitting body layer side, it will become easy to generate | occur | produce a dark spot.

  However, since the light emitter protective film 20a (see FIG. 1) according to the present embodiment includes the polyester-based auxiliary film 12 together with the gas barrier film 10a, even if the gas barrier film has a relatively large defect, the gas barrier property. Can be reduced. Moreover, generation of dark spots can be suppressed by using the auxiliary film adhesive layer 11 having a barrier property. Therefore, since the vapor deposition method can be used to form the inorganic thin film layer, the generation of dark spots can be suppressed while reducing the manufacturing cost.

The thickness of the inorganic thin film layer 3 is preferably 10 to 300 nm, and more preferably 20 to 100 nm. When the thickness of the inorganic thin film layer 3 is 10 nm or more, there is a tendency that a uniform film is easily obtained and gas barrier properties are easily obtained. On the other hand, when the thickness of the inorganic thin film layer is 300 nm or less, flexibility can be maintained, and cracks due to external forces such as bending and tension after film formation tend not to occur.

(Composite coating layer 4)
Next, the composite coating layer 4 will be described. In order to have gas barrier properties, the composite coating layer 4 is preferably formed from a composition containing at least one selected from the group consisting of a metal alkoxide represented by the following formula (1) and a hydrolyzate thereof.
M (OR ¹ ) _m (R ² ) _nm (1)
In the above formula (1), a monovalent organic group having 1 to 8 carbon atoms R ¹ and R ² are each independently preferably an alkyl group such as a methyl group, an ethyl group. M represents an n-valent metal atom such as Si, Ti, Al, or Zr. m is an integer of 1 to n.

Examples of the metal alkoxide include tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ], triisopropoxyaluminum [Al (O-iso-C ₃ H ₇ ) ₃ ] and the like. The metal alkoxide is preferably tetraethoxysilane or triisopropoxyaluminum because it is relatively stable in an aqueous solvent after hydrolysis.

Examples of the hydrolyzate of the metal alkoxide include silicic acid (Si (OH) ₄ ) that is a hydrolyzate of tetraethoxysilane and aluminum hydroxide (Al (OH) ₃ that is a hydrolyzate of tripropoxyaluminum. ) And the like. These can be used in combination of not only one type but also a plurality of types. Content of the metal alkoxide and its hydrolyzate in the said composition is 10-90 mass%, for example.

  The composition may further contain a hydroxyl group-containing polymer compound. Examples of the hydroxyl group-containing polymer compound include water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone and starch. The hydroxyl group-containing polymer compound is preferably polyvinyl alcohol from the viewpoint of barrier properties. These can be used in combination of not only one type but also a plurality of types. The content of the hydroxyl group-containing polymer compound in the composition is, for example, 10 to 90% by mass.

  The thickness of the composite coating layer 4 is preferably 50 to 1000 nm, and preferably 100 to 500 nm. When the thickness of the composite coating layer 5 is 50 nm or more, a sufficient gas barrier property tends to be obtained, and when it is 1000 nm or less, a sufficient flexibility tends to be maintained.

[Backlight unit]
FIG. 6 is a schematic cross-sectional view of a backlight unit 40 obtained using the wavelength conversion sheets 30a, 30am, 30b, and 30bm of the present invention. In FIG. 6, the backlight unit 40 includes a light guide plate 33 and a reflection plate 36 arranged in this order on the light emitter protection films 20 a, 20 am, 20 b, and 20 bm of the wavelength conversion sheets 30 a, 30 am, 30 b, and 30 bm. Is arranged on the side of the light guide plate 33 (the surface direction of the light guide plate 33).

  The light guide plate 33 and the reflection plate 36 efficiently reflect and guide the light emitted from the light source 32, and a known material is used. As the light guide plate 33, for example, acrylic, polycarbonate, cycloolefin film, or the like is used. For example, the light source 32 is provided with a plurality of blue light emitting diode elements. The light emitting diode element may be a violet light emitting diode or a light emitting diode having a lower wavelength.

The light emitted from the light source 32 enters the light guide plate 33 (arrow D1 direction), and then enters the phosphor layer 21 (arrow D2 direction) with reflection and refraction. The light that has passed through the phosphor layer 21 becomes white light by mixing the yellow light generated in the phosphor layer 21 with the light before passing through the phosphor layer 21.

[Electroluminescence light emitting unit]
FIG. 7 is a schematic cross-sectional view of an electroluminescence light emitting unit 50 obtained using the protective films 20a, 20am, 20b, and 20bm of the present invention. The electroluminescence light emitting unit 50 includes at least an electroluminescence light emitter layer 56 and light emitter protection films 20a, 20am, 20b, and 20bm.

  The electroluminescent light emitting unit 50 shown in FIG. 7 includes, for example, a transparent electrode layer 54, an electroluminescent light emitting layer 56 provided on the transparent electrode layer 54, and a dielectric provided on the electroluminescent light emitting layer 56. An electrode element 60 including a body layer 58 and a back electrode layer 59 provided on the dielectric layer 58 is obtained by sandwiching and sealing between the light emitter protection films 20a, 20am, 20b, and 20bm of the present invention. It is done. In addition, you may laminate | stack between the light-emitting body protective films 20a, 20am, 20b, and 20bm and the electrode element 60 through a sealant.

  According to the electroluminescent light emitting unit 50 of the present invention, by using the light emitter protective films 20a, 20am, 20b, and 20bm provided with the polyester-based auxiliary film 12 on both surfaces of the electrode element 60 including the electroluminescent light emitter layer 56, Even if the gas barrier films of the light emitter protection films 20a, 20am, 20b, and 20bm have wrinkles and defects, the deterioration of the gas barrier property can be suppressed and the generation of dark spots near the defects can be suppressed.

  Hereinafter, the present invention will be described with reference to examples. However, the present invention is not limited to the following examples without departing from the gist of the present invention.

<Example 1>
[Production of Gas Barrier Film 10a (see FIG. 1)]
(Anchor coat layer 2)
Acrylic polyol and tolylene diisocyanate are mixed so that the number of NCO groups of tolylene diisocyanate is equal to the number of OH groups of acrylic polyol, and ethyl acetate is added so that the total solid content becomes 5% by mass. Diluted. Β- (3,4 epoxy cyclohexyl) trimethoxysilane is further added to the diluted liquid mixture so as to be 5% by mass with respect to the total solid content, and these are mixed to obtain an anchor coat layer composition. Produced.

  By applying the anchor coat layer composition to the corona-treated surface of a polyester film substrate 1 having a thickness of 12 μm (trade name: P60, manufactured by Toray Film Co., Ltd.) by drying and curing at 100 ° C. for 1 minute, An anchor coat layer 2 having a thickness of 50 nm was formed.

(Inorganic thin film layer 3)
A silicon oxide material (SiO, manufactured by Canon Optron Co., Ltd.) is evaporated by electron beam heating under a pressure of 1.5 × 10 ⁻² Pa using an electron beam heating type vacuum deposition apparatus, and the anchor coat layer 2 is A SiOx film (inorganic thin film layer 3) having a thickness of 30 nm was formed. In addition, the acceleration voltage in vapor deposition was 40 kV, and the emission current was 0.2 A.

(Composite coating layer 4)
Next, 10.4 parts by mass of tetraethoxysilane and 89.6 parts by mass of hydrochloric acid (concentration: 0.1 N) were mixed, and the mixture was stirred for 30 minutes to obtain a hydrolyzed solution of tetraethoxysilane. On the other hand, polyvinyl alcohol was dissolved in a mixed solvent of water / isopropyl alcohol (water / isopropyl alcohol (mass ratio) = 90/10) to obtain a 3% by mass polyvinyl alcohol solution. 60 parts by mass of a tetraethoxysilane hydrolysis solution and 40 parts by mass of a polyvinyl alcohol solution were mixed to obtain a composite coating composition.

  The composite coating layer composition having a thickness of 300 nm was formed on the inorganic thin film layer 3 by applying and drying the composite coating layer composition to obtain a gas barrier film 10a.

  Next, the following adhesive A is applied as the auxiliary film adhesive layer 11 on the surface of the composite coating layer 4 of the gas barrier film 10a obtained above, and an easy-slip layer is applied to both sides of the adhesive A application surface. A polyester auxiliary film 12 made of a polyester film having a thickness of 50 μm (manufactured by Toyobo Co., Ltd., trade name: Cosmo Shine A4200) was pasted and aged at 50 ° C. for 2 days. Thus, it bonded through the auxiliary film contact bonding layer 11 which has a thickness of 5 micrometers, and obtained the light-emitting body protective film 20a of the form shown in FIG.

  Adhesive A is MAXIVE (trade name) manufactured by Mitsubishi Gas Chemical Co., Ltd., and the blending ratio is [epoxy resin main agent / amine hardener / methanol / ethyl acetate = 1/3/3/6 (mass ratio)]. It is an adhesive composition obtained by mixing a main agent composed of an epoxy resin and a curing agent composed of a polyamine resin.

(Matte layer)
Next, 100 parts by mass of acrylic resin (trade name: Akari Dick, manufactured by DIC) and silica particles (trade name: Tospearl 120, average particle diameter: 2.0 μm) are formed on the outer surface of the polyester film substrate 1 of the luminous body protective film 20a. , Manufactured by Momentive Performance Materials Co., Ltd.), a composition comprising 20 parts by mass was applied. The coating layer was heated to cure the acrylic resin, thereby forming a mat layer M (see FIG. 3) having a thickness of 3 μm. In this way, a light emitter protective film 20am (see FIG. 3) was obtained in which the mat layer M, the gas barrier film 10a, the auxiliary film adhesive layer 11, and the polyester auxiliary film 12 of 50 μm or more were laminated in this order.

<Example 2>
[Production of Polyester Film Base 1 of Gas Barrier Film 10a]
Using a raw material polymer of polyester resin having high hydrolysis resistance as a film raw material polymer, the resin was melt-extruded into a sheet shape, rapidly cooled and solidified on a cooling metal roll, and an unstretched polyethylene terephthalate (PET) sheet was obtained. . This unstretched PET sheet was stretched 3.5 times in the flow direction with a heated roll group and an infrared heater to obtain a uniaxially stretched PET film.

  Next, after applying a coating solution in which a lubricant is dispersed in polyester and a blocked isocyanate aqueous solution as an easy-sliding layer by an in-line coating method, it is stretched 4.0 times in the width direction at 120 ° C with a tenter. Then, the film was heated and relaxed at 230 ° C. with the film length in the width direction fixed.

  As a result, a polyester film substrate 1 having a film thickness of 23 μm and an easy-slip layer thickness of 50 nm was obtained. This film had an acid value of 24 and a number average molecular weight of 61,000. Thereafter, a light emitter protective film 20am was produced through the gas barrier film 10a in the same procedure as in Example 1.

<Example 3>
On the surface of the composite coating layer 4 of the same gas barrier film 10a as in Example 1, the adhesive A is applied as the adhesive layer 5, and the composite coating of 10a ′ in which the gas barrier film 10a is turned upside down on the surface to which the adhesive A is applied. The surfaces of layer 4 were bonded together and aged at 50 ° C. for 2 days. In this way, two gas barrier films (10a, 10a ′) were bonded together through the adhesive layer 5 having a thickness of 5 μm to obtain a gas barrier film 10b (see FIG. 4). The same adhesive A as in Example 1 was applied to one side of the gas barrier film 10b as the auxiliary film adhesive layer 11, and a 50 μm thick polyester film (manufactured by Toyobo Co., Ltd.) having an easy-slip layer on both sides of the adhesive A applied surface. A polyester-based auxiliary film 12 made of a product name: Cosmo Shine A4200) was bonded and aged at 50 ° C. for 2 days. Thus, it bonded through the auxiliary film contact bonding layer 11 which has a thickness of 5 micrometers, and obtained the light-emitting body protective film 20b of the form shown in FIG. Thereafter, the mat layer M was formed in the same procedure as in Example 1 to produce the light emitter protective film 20bm (FIG. 5).

<Example 4>
As the auxiliary film adhesive layer 11 of Example 3, a light emitter protective film 20bm was produced in the same procedure as in Example 3 except that the following adhesive B was applied.

  As the adhesive B, a pressure sensitive adhesive manufactured by Seiden Chemical Co., Ltd. was selected. A main component made of an acrylic polyol resin having a blending ratio of [acrylic polyol resin main agent / polyisocyanate hardener / toluene = 25 / 0.34 / 31.25 (mass ratio)] and a curing agent made of an isocyanate resin were mixed. It is a pressure-sensitive adhesive of the composition obtained.

<Example 5>
In the production of the phosphor protective film 20a of Example 1 (see FIG. 1), Example 1 was used except that a polyester film (BH) having a thickness of 50 μm and no slip layer was used as the polyester-based auxiliary film 12. The light emitter protective film 20am (see FIG. 3) was obtained in the same procedure as above. In order to improve the adhesion with the light emitter on the outer surface of the polyester-based auxiliary film 12 of the light emitter protection film 20am, 3-methacryloxypropyltrimethoxysilane (methacrylic silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd., An adhesion coating solution obtained by diluting trade name: KBM-503) to 0.05% by mass with ethyl acetate was applied to form an adhesion coating layer (not shown) having a thickness of 10 nm.

<Comparative Example 1>
In the production of the phosphor protective film 20a (FIG. 1) of Example 1, the auxiliary film adhesive layer 11 was used in Example 4 on the surface of the composite coating layer 4 of the gas barrier film 10a obtained in the same manner as in Example 1. Except having used the adhesive B which was made, the light-emitting body protective film 20a was obtained in the same procedure as Example 1.

(Matte layer)
Next, a mat layer having a thickness of 3 μm made of the same material as in Example 1 was formed on the outer surface of the polyester-based auxiliary film 12. In this way, a light emitter protective film 25am (FIG. 8) was obtained in which the mat layer M, the polyester-based auxiliary film 12, the auxiliary film adhesive layer 11, and the gas barrier film 10a ′ were laminated in this order. Therefore, the positions of the polyester auxiliary film 12 and the gas barrier films 10a and 10a ′ are interchanged with the light emitter protective films 20am and 20am ′ of Example 1.

[Evaluation of phosphor protective film]
(Measurement of oxygen permeability of adhesive layer)
The same adhesive A and adhesive B as those used in Examples 1 to 5 and Comparative Example 1 were applied on a CPP (unstretched polypropylene) film having a thickness of 70 μm, respectively, and the adhesive A application surface was further applied. A 70μm thick CPP film is bonded to each other and aged to 70μm thickness.
A sample for measuring oxygen permeability (laminated body) was obtained by laminating a CPP, an adhesive layer having a thickness of 5 μm, and a CPP having a thickness of 70 μm in this order.

  The obtained sample was placed in a differential pressure type gas permeability measuring apparatus (GTR-30X, manufactured by GTR Tech Co., Ltd.), and the temperature was 40 ° C. and the relative humidity was 0 according to the method described in JIS K7126-1 (Appendix 1). The oxygen permeability of the above sample was measured by a differential pressure method at a differential pressure of 101 kPa (1 atm) with oxygen as a test gas in a% environment.

The measurement result of the oxygen permeability of the adhesive A was 100 cm ³ / (m ² · day · atm). The measurement result of the oxygen permeability of the adhesive B was 2500 cm ³ / (m ² · day · atm). Since the oxygen permeability of ^two CPPs having a thickness of 70 μm is 2500 cm ³ / (m ² · day · atm), which is the same value as this, the oxygen permeability of the adhesive B is> 2500 cm ³ / (m ² · day).・ Atm).

(Measurement of water vapor permeability of illuminator protection film)
The water vapor permeability of the phosphor protective films obtained in Examples 1 to 5 and Comparative Example 1 above is determined by measuring the water vapor permeability by an isobaric method (product name: Aquatran, manufactured by mocon), temperature 40 ° C., relative humidity 90 The test gas was measured as nitrogen in a% environment.

[Production of wavelength conversion sheet]
Concentration adjustment by dispersing a phosphor (trade name: CdSe / ZnS 530, manufactured by SIGMA-ALDRICH) having a core / shell structure in which cadmium selenide (CdSe) particles are coated with zinc sulfide (ZnS) in a solvent. Thus, a phosphor dispersion liquid was prepared. This phosphor dispersion was mixed with an epoxy photosensitive resin to obtain a phosphor composition.

  The phosphor protective films obtained in Examples 1 to 5 and Comparative Example 1 were set in the first paper feed in the roll-to-roll process, and the surface opposite to the mat layer side (in the above Examples 1 to 5, the polyester-based auxiliary film) The phosphor composition was coated on the surface 12 and the surface of the polyester film substrate 1 of the gas barrier film 10a in Comparative Example 1 with a die coat and dried with a solvent, and then a phosphor layer having a thickness of 100 μm was formed. Further, the second phosphor protective film obtained in Examples 1 to 5 and Comparative Example 1 was unwound from the second paper feed, and a phosphor layer was formed so as to be bonded to the opposite side of the mat layer side. After bonding with the first paper feeding, nip and pressure bonding, the phosphor layer (containing the photosensitive resin) is cured by ultraviolet irradiation, additional heat aging is performed to accelerate the curing, Examples 1, 2, Wavelength conversion sheet 30am (FIG. 3) using the phosphor protective film 20am prepared in 5, wavelength conversion sheet 30bm (FIG. 5) using the phosphor protective film 20bm prepared in Examples 3 and 4, and Comparative Example 1 The wavelength conversion sheet 35am (FIG. 9) using the light emitter protective film 25am (FIG. 8) produced in the above was obtained.

(Appearance evaluation)
The wavelength conversion sheets obtained in Examples 1 to 5 and Comparative Example 1 were cut into 10 cm × 10 cm, visually observed through a fluorescent lamp, and when coating unevenness was observed, it was determined that there was unevenness.

(Adhesion evaluation)
The wavelength conversion sheets obtained in Examples 1 to 5 and Comparative Example 1 were cut into a size of 60 cm × 34 cm (corresponding to a 27-inch monitor), and were subjected to an environment of temperature 65 ° C. and humidity 95% RH as an accelerated test. Stored for 500 hours. After the storage, the case where the floating occurred from the trimmed end portion was judged as poor adhesion.

(Dark spot evaluation)
The wavelength conversion sheet obtained in Examples 1 to 5 and Comparative Example 1 is 60 cm × 34 cm (27
It was cut into a size equivalent to an inch monitor) and stored as an accelerated test in an environment of a temperature of 65 ° C. and a humidity of 95% RH for 500 hours. After storage, the sample was irradiated with UV light, and the number of black spot-like defects (dark spots) was visually counted. When the number of dark spots was 5 or less, it was judged as a good product.

(Luminance evaluation)
The wavelength conversion sheets obtained in Examples 1 to 5 and Comparative Example 1 were cut into 10 cm × 10 cm, placed on a blue backlight unit, and initially used with an ultra-low luminance spectral radiometer SR-UL2 (manufactured by TOPCON). Luminance measurement was performed. As an accelerated test, this sample was stored for 500 hours in an environment of a temperature of 65 ° C. and a humidity of 95% RH, and the luminance was measured in the same manner. Relative luminance evaluation was made by dividing the luminance after storage for 500 hours by the initial luminance. The luminance was judged as good if it kept 85% or more of the initial luminance.

  The evaluation results are summarized in Table 1.

  As shown in Table 1, in Examples 1 to 5, no unevenness was found in the appearance of the wavelength conversion sheet produced. However, in Comparative Example 1, groove-shaped coating unevenness was observed at intervals of 5 mm to 2 cm along the flow direction of the roll-to-roll process. This is a structure in which the structure of the wavelength conversion sheet of Comparative Example 1 is prepared by applying the phosphor layer 21 coating liquid to the polyester film substrate 1 instead of the polyester-based auxiliary film 12 as shown in FIG. Because.

  In the evaluation after storage for 500 hours in an environment of 65 ° C. and humidity of 95% RH, there is no problem in the end portion in Examples 1 to 5 in the adhesion evaluation, but in Comparative Example 1, it floats about 5 to 10 mm from the end portion to the inside. Some parts were seen. This is considered to be the influence of the coating unevenness.

  In the dark spot evaluation, it did not occur in Examples 1 to 3 and 5, but in Example 4, since the adhesive B having an inferior barrier property is used as the auxiliary film adhesive layer 11, three occurrences were observed. It was done. This time, up to 5 products are considered to be good products, but depending on the product specifications, this is a problem. On the other hand, in Comparative Example 1, 23 dark spots that were considered to be due to the poor adhesion were generated, resulting in a defective product.

  In the luminance evaluation, Examples 1 to 5 and Comparative Example 1 all maintained 85% or more, and there was no problem. In particular, Examples 3 and 4 showed a high value of 90% or more, and it was confirmed that luminance deterioration hardly occurred when the water vapor permeability of the phosphor protective film was low and the barrier property was high.

  From the above results, in the wavelength conversion sheets of Examples 1 to 5 produced according to the present invention, the adhesion failure due to the acceleration test does not occur, the generation of dark spots can be suppressed, and the light emitting body deteriorates even when the acceleration test is performed. As a result, it was found that the luminance was hardly lowered.

  In particular, the wavelength conversion sheet 30bm of Examples 3 and 4 includes the two-layer gas barrier film 10b bonded with the barrier film adhesive layer 5 on both sides as shown in FIGS. 5 and 4, and maintains high luminance after the acceleration test. In addition, it can be suitably used for a material in which a light emitter easily reacts with oxygen or water vapor or the like in the air atmosphere, such as organic electroluminescence, and the light emitter protection film requires high barrier properties.

DESCRIPTION OF SYMBOLS 1 ... Polyester film base material 2 ... Anchor coat layer 3 ... Inorganic thin film layer 4 ... Composite film layer 34 ... Gas barrier film layer 5 ... Barrier film adhesion layer 10a, 10a ', 10b ... Gas barrier film 11 ... Auxiliary film adhesive layer 12 ... Polyester type auxiliary film 20a, 20a', 20b, 20b '... Luminescent body protective film 20am, 20am', 20bm, 20bm '... Light emitter protective film (with matte layer)
25am, 25am '... wavelength conversion sheet of Comparative Example 1 (with mat layer)
M ... Matte layer 21 ... Phosphor layer 30a, 30b ... Wavelength conversion sheet 30am, 30bm ... Wavelength conversion sheet (with matte layer)
35am ... Wavelength conversion sheet of Comparative Example 1 (with mat layer)
32 ... Light source 33 ... Light guide plate 36 ... Reflector plate 40 ... Backlight unit 50 ... Electroluminescence light emitting unit 54 ... Transparent electrode layer 56 ... Electroluminescence light emitter layer 58... Dielectric layer 59... Back electrode layer 60... Electrode element 70, 70 ′. 72 ... Gas barrier layer 73 ... Phosphor layer 80 ... Wavelength conversion sheet

Claims (13)

A phosphor protective film that forms part of the wavelength conversion sheet or electroluminescence unit and protects the phosphor layer of the wavelength conversion sheet or the phosphor layer of the electroluminescence unit,
A gas barrier film, and an auxiliary film made of a polyester film and having a thickness of 50 μm or more,
The auxiliary film is formed between the gas barrier film and the phosphor layer or the phosphor layer. The gas barrier film comprises a base material made of a polyester film, an anchor coat layer, and a gas barrier film layer,
The gas barrier film layer includes an inorganic thin film layer made of an inorganic compound, and a composite film layer made of a composition containing at least one of a hydroxyl group-containing polymer compound, a metal alkoxide, a silane coupling agent, or a hydrolyzate thereof. The light emitter protective film according to claim 1, wherein: The gas barrier film and the auxiliary film are bonded through an auxiliary film adhesive layer,
^3. The light emitter protection according to claim 1, wherein the adhesive forming the auxiliary film adhesive layer has an oxygen permeability of 1000 cm ³ / (m ² · day · atm) or less at a thickness of 5 μm. the film.   4. The light emitter protective film according to claim 3, wherein the gas barrier film and the auxiliary film are bonded so that the gas barrier film layer and the auxiliary film adhesive layer are in contact with each other.   The light emitter protective film according to claim 3 or 4, wherein the adhesive is an adhesive containing an epoxy resin.   The phosphor protective film according to claim 1, wherein the auxiliary film has a total light transmittance of 88% or more.   The luminous body protective film according to any one of claims 1 to 6, wherein a coating layer formed integrally with the auxiliary film is provided on one side or both sides of the auxiliary film.   The phosphor protective film according to claim 1, wherein an adhesion coating layer containing a silane coupling agent is provided on a surface of the auxiliary film that is in contact with the phosphor layer or the phosphor layer. .   The phosphor protective film according to any one of claims 2 to 9, wherein the base material made of the polyester film of the gas barrier film has hydrolysis resistance.   The light emission according to any one of claims 1 to 10, wherein the gas barrier film is formed by bonding two gas barrier films through a barrier film adhesive layer so that the composite coating layers face each other. Body protection film.   The phosphor layer includes a resin and a phosphor, and the phosphor protective film according to any one of claims 1 to 10 is laminated on both surfaces of the phosphor layer. A backlight unit comprising a light source, a light guide plate, a reflection plate, and the wavelength conversion sheet according to claim 11.   An electroluminescent light-emitting unit comprising an electroluminescent light-emitting layer, wherein the light-emitting protective film according to claim 1 is laminated on both surfaces of the electroluminescent light-emitting layer.

Images