JP7310700B2 - BARRIER FILM, WAVELENGTH CONVERSION SHEET USING THE SAME, AND DISPLAY DEVICE USING THE SAME - Google Patents

Description

TECHNICAL FIELD The present invention relates to a wavelength conversion sheet mainly used as a backlight source for display devices.

In recent years, with the development of personal computers, especially portable personal computers, the demand for liquid crystal display devices is increasing. In addition, recently, the penetration rate of liquid crystal televisions for home use is increasing, and smartphones and tablet terminals are also becoming widespread, so the market for liquid crystal display devices is expanding more and more.

Such a liquid crystal display device generally has a liquid crystal cell portion having a color filter, a counter substrate, and a liquid crystal layer sandwiched therebetween, and further has a light source called a backlight portion.

Recently, development of backlight members using quantum dot technology is also underway. Quantum dots refer to nanometer-sized fine particles of semiconductors. Quantum dots can also be tuned over the entire visible range of emission wavelengths due to the quantum confinement effect (quantum size effect) in which electrons and excitons are confined within nanometer-sized small crystals. Quantum dots can emit strong fluorescence in a narrow wavelength band, so that a display device can be illuminated with light of three primary colors with excellent color purity. Therefore, a display device having excellent color reproducibility can be obtained with a backlight using quantum dots.

The wavelength conversion sheet used for the backlight source of this display device consists of a phosphor layer in which semiconductor nanometer-sized fine particles are dispersed in a resin layer, and a phosphor layer that suppresses deterioration of the phosphor layer. It has a structure in which barrier films are laminated on both surfaces and combined with an LED light source.

For example, a wavelength conversion sheet in which a barrier film is laminated on a phosphor layer containing a phosphor, the barrier film being a wavelength conversion sheet in which a barrier layer is laminated on one side of a predetermined polyethylene terephthalate film, and a backlight using the same A unit has been developed (Patent Document 1). A wavelength conversion sheet using a barrier film with excellent barrier properties and transparency can provide a display device with more natural vivid colors and excellent color tone.

WO2015/037733

Here, when a wavelength conversion sheet is used in a display device, the on-edge method in which the wavelength conversion sheet is mounted along the end face of the light guide plate of the backlight and the surface on which the wavelength conversion sheet is mounted on the back surface of the light guide plate are used. There is a mounting method that uses a light guide plate, such as a mounting method. In addition to the mounting method using a light guide plate, there is also a direct type method in which LEDs are arranged on the back side instead of the light guide plate and the light emitted from the light source is irradiated to the wavelength conversion sheet through a diffusion plate. .

In the surface mounting method, the back surface of the light guide plate and the wavelength conversion sheet are placed in contact with each other, so that the light emitted from the LEDs irradiates the wavelength conversion sheet through the diffuser plate. The surface mounting method can reduce the influence of heat emitted from the LED.

On the other hand, in the direct type method, the back surface of the diffuser plate and the wavelength conversion sheet are placed in contact with each other, so that the light emitted from the LEDs is diffused by the diffuser plate and radiated onto the wavelength conversion sheet. The direct type method makes it easy to maintain the brightness of the entire screen, and can display high-brightness image quality.

However, when the surface-mount type or direct type display device mounted with the wavelength conversion sheet is changed from a normal temperature and normal humidity environment to a specific atmospheric environment such as a low temperature, high temperature, low humidity, or high humidity, or when a specific atmosphere changes. The inventors of the present invention have found that a phenomenon may occur in which the barrier film of the wavelength conversion sheet partially sticks to the light guide plate, diffusion plate, etc., when the ambient environment changes to a room temperature and humidity environment. clarified by et al.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a barrier film for a wavelength conversion sheet that can effectively suppress sticking of a light guide plate, a diffusion plate, or the like to a wavelength conversion sheet. for the purpose.

In order to solve the above-mentioned problems, the present inventors have made intensive studies and found that a barrier film in which an anti-sticking layer containing a resin and a filler is laminated on one surface of the barrier film. The inventors have found that the problem can be solved, and have completed the present invention.

(1) A barrier film for a wavelength conversion sheet, which is used as a backlight source of a display device and arranged on one surface of a phosphor layer containing a phosphor,
The barrier film is a multilayer film containing at least a barrier layer and a substrate layer,
On one surface of the barrier film,
A sticking prevention layer containing a resin and a filler is laminated,
The filler contains a resin having a compressive strength of 2.8 kgf/mm ² or more as measured in accordance with JIS A 9511,
A barrier in which the coating amount of the anti-sticking layer after drying is 1.0 g/m ² or more and 3.6 g/m ² or less, and the haze value measured according to JIS K7136 is 10% or more and 35% or less. the film.

(2) The barrier film according to (1), wherein the filler contained in the anti-sticking layer contains an acrylic resin.

(3) The barrier film according to (1) or (2), wherein the resin contained in the anti-sticking layer contains an acrylic resin.

(4) The barrier film according to any one of (1) to (3), wherein a primer layer is laminated on the surface of the barrier film on which the phosphor layer is laminated.

(5) one surface of the phosphor layer containing the phosphor, and the surface of the barrier film according to any one of (1) to (4) opposite to the surface on which the anti-sticking layer is laminated; and are laminated so as to face each other.

(6) A display device of a surface mount system including a light guide plate, wherein the light guide plate is arranged on the surface of the sticking prevention layer of the wavelength conversion sheet according to (5).

(7) A direct type display device including a diffusion plate, wherein the diffusion plate is arranged on the surface of the sticking prevention layer of the wavelength conversion sheet according to (5).

The barrier film for the wavelength conversion sheet of the present invention can effectively suppress sticking between the light guide plate or the diffusion plate and the wavelength conversion sheet.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which represented typically the wavelength conversion sheet which concerns on one Embodiment of this invention. It is a sectional view showing typically a barrier film arranged on the display side of a display of a wavelength conversion sheet concerning one embodiment of the present invention. 1 is a cross-sectional view schematically showing an arrangement in a surface mount type display device according to an embodiment of the present invention; FIG. 1 is a cross-sectional view schematically showing an arrangement in a direct type display device according to an embodiment of the present invention; FIG. It is sectional drawing which represented typically the wavelength conversion sheet which concerns on other embodiment of this invention. It is sectional drawing which represented typically the barrier film arrange|positioned at the display surface side of the display apparatus of the wavelength conversion sheet which concerns on other embodiment of this invention.

Hereinafter, specific embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments at all, and can be implemented with appropriate modifications within the scope of the purpose of the present invention. can do.

<<1. Wavelength conversion sheet>>
As shown in FIG. 1, the wavelength conversion sheet 10 includes a phosphor layer 11 containing a phosphor 112 and a sealing resin 111, and a barrier film 1 and a barrier film 2 on both surfaces of the phosphor layer 11. Laminated. By laminating barrier films 1 and 2 on both surfaces of the phosphor layer 11, barrier properties are imparted to the phosphor layer. In this specification, the two surface sides of the phosphor layer refer to the side where the light source is arranged (light incident surface side) and the side where the backlight light source is arranged when the wavelength conversion sheet 10 is used as a backlight source. It means the surface side of both the opposite side (light emitting surface side) from the side where the light is formed.

The barrier film 1 is arranged on the side of the wavelength conversion sheet 10 that is in contact with the back surface of the light guide plate. A sticking prevention layer 16 is laminated on one surface of the barrier film 1 . By arranging the light guide plate on the surface of the sticking prevention layer, sticking between the light guide plate and the wavelength conversion sheet can be effectively suppressed.

Although the wavelength conversion sheet 10 in FIG. 1 is configured such that the anti-sticking layer 16 is laminated only on one surface of the barrier film 1, the surface of the barrier film 2 (in FIG. A sticking prevention layer may also be laminated on the surface on the side of the material layer 25 (not shown). For example, in the wavelength conversion sheet 10 of FIG. 1, when the optical film is arranged on the side of the barrier film 2 (the side of the second base material layer 25), the optical film is arranged on the surface of the anti-sticking layer. If there is, sticking between the optical film and the wavelength conversion sheet can be similarly effectively suppressed.

<<2. Barrier film>>
The barrier film 1 according to this embodiment is a multilayer film including at least a barrier layer and a substrate layer, as shown in FIG. Specifically, the first base material layer 12, the barrier layer 13 (organic coating layer 13a, inorganic oxide thin film layer 13b), the adhesive layer 14, and the second base material layer 15 are arranged in this order. An anti-sticking layer 16 is laminated on the surface of the barrier film 1 on the side of the second base material layer 15 . By arranging the light guide plate on the surface of the sticking prevention layer, sticking of the light guide plate wavelength conversion sheet can be effectively suppressed. Each layer will be described below using the barrier film 1 shown in FIG.

[Sticking prevention layer]
The anti-sticking layer 16 is a layer containing a resin 161 and a filler 162, and the surface of the anti-sticking layer 16 does not have a uniform flat shape, and the filler is not present in the anti-sticking layer. By being included, at least a portion of the filler protrudes to form a structure. Such an anti-stick layer can effectively suppress sticking between the anti-stick layer 16 and the light guide plate 6 .

The phrase "anti-sticking layer in which at least part of the filler protrudes" means that the surface of the anti-sticking layer does not have a uniform flat shape, and the surface of the sticking-preventing layer is undulated due to the filler. It means that it is formed and/or that at least part of the filler is exposed from the surface of the anti-sticking layer.

Furthermore, by providing the barrier film with an anti-sticking layer, it is possible to prevent the barrier film or the wavelength conversion sheet from sticking to each other when the barrier film or the wavelength conversion sheet is wound into a roll. Therefore, the barrier film or wavelength conversion sheet can be stored or transported in a roll form.

Also, this filler 162 contains a resin having a compressive strength of 2.8 kgf/mm ² or more. This resin preferably has a compressive strength of 3.0 kgf/mm ² or more, more preferably 4.0 kgf/mm ² or more. Examples of resins having a density of 2.8 kgf/mm ² or more include acrylic resins. The acrylic resin is an ethylenically unsaturated monomer having at least one carboxyl group or carboxylic acid ester group selected from the group consisting of methacrylic acid, acrylic acid, methacrylic acid ester, and acrylic acid ester. It is a polymer contained as a component.

In particular, when a display device in which a light guide plate is arranged on the surface of the sticking prevention layer of the wavelength conversion sheet is transported, the sticking prevention layer and the light guide plate (diffusion plate) rub against each other and stick together. The anti-sticking layer may be scratched. Alternatively, the anti-sticking layer and the light guide plate may rub against each other to generate fragments from the anti-sticking layer, and the fragments may damage the anti-sticking layer and the light guide plate. Such scratches on the anti-sticking layer and the light guide plate may result in poor appearance of the display device.

Therefore, in the barrier film according to the present embodiment, the coating amount of the anti-sticking layer after drying is 1.0 g/m ² or more and 3.6 g/m ² or less, and the haze value is 10% or more and 35% or less. It is characterized by a If the coating amount of the anti-sticking layer after drying is less than 1.0 g/m ² , the anti-sticking layer becomes thin against the filler, and impurities enter between the anti-sticking layer and the light guide plate. It may damage the anti-sticking layer and the light guide plate (diffusion plate). If the coating amount of the sticking-preventing layer after drying exceeds 3.6 g/m ² , the filler may be embedded in the sticking-preventing layer, impairing the function of the sticking-preventing layer.

Further, if the haze value of the sticking-preventing layer is less than 10%, the number of fillers contained in the sticking-preventing layer is not sufficient, so that the scratch resistance of the sticking-preventing layer deteriorates, and furthermore, the sticking-preventing layer and the conductive layer become conductive. It may become impossible to effectively suppress sticking to the light plate. When the haze value of the sticking-preventing layer exceeds 35%, the scratch resistance of the sticking-preventing layer deteriorates, and furthermore, the haze value is too high, so that the function as a display device deteriorates. The haze value can be measured using a haze meter according to JIS K7136.

By providing the anti-sticking layer with the coating amount and haze value after drying set within the above ranges, it is possible to effectively suppress damage to the anti-sticking layer and the light guide plate (diffusion plate).

In addition, in the case where the sticking prevention layer is laminated on the surface of the barrier film 2 (the surface on the side of the second base material layer 25 in FIG. 1) and the sticking prevention layer and the optical film are in contact with each other, The same is true even if there is That is, by providing the anti-sticking layer having the coating amount and haze value after drying within the above ranges, it is possible to effectively suppress damage to the anti-sticking layer and the optical film.

In particular, when the optical film is a prism sheet, it can be said that the optical film is easily damaged compared to other optical films because the prisms may be chipped depending on the shape of the prism sheet.

Therefore, when a prism sheet is used as an optical film, an optical film (prism sheet) is obtained by laminating an anti-sticking layer on the surface of the barrier film 2 with a coating amount after drying and a haze value within the above ranges. can be effectively prevented from being damaged.

The thickness of the anti-sticking layer is not particularly limited as long as the effects of the present invention can be achieved. For example, it is preferably 1.0 μm or more and 50.0 μm or less, more preferably 1.5 μm or more and 10.0 μm or less. The thickness of the anti-sticking layer means the thickness of the resin portion other than the filler in the anti-sticking layer, and does not include the portion of the filler protruding above the resin. The thickness of the anti-sticking layer can be measured, for example, by observing a cross section with a scanning electron microscope or the like. The resin and filler contained in the anti-sticking layer are described below.

(resin)
The resin 161 contained in the anti-sticking layer is not particularly limited as long as it can achieve the object of the present invention. Resins, polyurethane acrylate-based resins, acrylic urethane-based resins, epoxy acrylate-based resins, and the like can be used. Among them, an acrylic resin is preferable from the viewpoint of having hardness.

When an acrylic resin is contained, the ratio of the acrylic resin to 100 parts by mass of the resin contained in the anti-sticking layer is preferably 60 parts by mass or more, more preferably 80 parts by mass or more.

(filler)
The filler suppresses sticking between the light guide plate and the wavelength conversion sheet. The filler is not particularly limited as long as it contains a resin having a compressive strength of 2.8 kgf/mm ² or more as measured according to JIS A 9511. Examples of resins having a compressive strength of 2.8 kgf/mm ² or more include acrylic resins and polystyrene resins.

The average particle diameter of the filler is preferably 1 μm or more and 50 μm or less, more preferably 1.5 μm or more and 10 μm or less. When the average particle diameter of the filler is 1 μm or more, at least part of the filler is exposed from the surface of the anti-sticking layer, and the sticking between the anti-sticking layer 16 and the light guide plate 6 is more effective. In addition, the scratch resistance of the sticking prevention layer can be improved. When the average particle diameter of the filler is 50 μm or less, it is possible to suppress the functional deterioration of the sticking-preventing layer due to the filler detaching from the sticking-preventing layer and the occurrence of scratches on the sticking-preventing layer due to demarketed filler. can do.

The average particle size is obtained, for example, as a value of D50 in particle size distribution measurement based on JIS Z8820 and Z8822. The average particle size can be measured, for example, by a dynamic light scattering method, a laser diffraction scattering method, or SEM or TEM observation.

The filler 162 has a particle diameter that is at least twice the thickness of the anti-sticking layer, and the proportion of the filler exposed from the anti-sticking layer is 20% by mass or more and 80% by mass or less. Preferably. It is possible to more effectively suppress sticking between the light guide plate and the wavelength conversion sheet.

The content of the filler is preferably 5% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 40% by mass or less, relative to the total amount of the anti-sticking layer. When the content is 5% by mass or more, sticking between the sticking prevention layer and other members such as the light guide plate can be more effectively prevented. When the content is 50% by mass or less, a sufficient amount of the resin for forming the sticking prevention layer can be secured, and the film formability of the sticking prevention layer is improved.

Among the fillers contained in the anti-sticking layer, the content of the filler protruding from the anti-sticking layer is preferably 2% by mass or more and 25% by mass or less, and 5% by mass or more, relative to the total amount of the anti-sticking layer. It is more preferably 20% by mass or less.

The difference in the refractive index of the filler from the refractive index of the resin contained in the anti-sticking layer is preferably 0.5 or less, more preferably 0.3 or less, and 0.1 or less. It is even more preferable to have

(Additive)
Additives such as a stabilizer, a curing agent, a cross-linking agent, a lubricant, an ultraviolet absorber, and others may optionally be added to the anti-sticking layer of the present embodiment, if necessary.

(Lamination method of sticking prevention layer)
The method of laminating the anti-sticking layer is not particularly limited, but for example, a coating agent for laminating the anti-sticking layer containing resin, filler, solvent, etc. is applied to the base layer of the barrier film and cured. be able to. Methods for applying the coating agent include roll coating, gravure coating, knife coating, dip coating, spray coating and other coating methods.

[Base material layer]
The substrate layer constitutes the multilayer film of the barrier film and is a layer mainly made of resin. The material that can be used for the base layer is not particularly limited as long as it does not impair the function of the wavelength conversion sheet. Examples include polyimide (PI), polyethylene naphthalate (PEN), and polyethylene terephthalate (PET). , polyethylene butyrate (PBT), amorphous polyarylate, polysulfone, polyethersulfone, polyetherimide, fluororesin, and liquid crystal polymer. Polyethylene naphthalate (PEN) and polyethylene terephthalate (PET) are preferred from the viewpoint of transparency and heat resistance, etc., which do not impair the function of the wavelength conversion sheet. The materials of the first base material layers 12 and 22 and the second base material layers 15 and 25 may be the same or different.

The thickness of the substrate layer in the barrier film 1 is not particularly limited, but when the substrate layer on which the barrier layer is formed (for example, the first substrate layers 12 and 22 in FIG. 1), The thickness is preferably 8 μm or more and 150 μm or less, more preferably 8 μm or more and 100 μm or less so as not to impair the performance of the barrier layer.

The barrier films 1 and 2 constituting the wavelength conversion sheet of FIG. 25 are laminated in this order. The barrier film 1 is not limited to a barrier film in which a first substrate layer, a barrier layer, and a second substrate layer are laminated in this order, and includes at least a barrier layer and a substrate layer. Any multilayer film may be used. That is, unlike the barrier film constituting the wavelength conversion sheet of FIG. 1, the barrier layer may be arranged as the outermost layer, or the number of substrate layers may be one. However, with the barrier film that constitutes the wavelength conversion sheet of FIG. 1, the barrier layers 13 and 23 are not exposed on the outermost surface of the barrier film. Defects in the phosphor layer caused by scratches and cracks in the barrier layer can be suppressed. Incidentally, there may be three or more base material layers.

In the barrier films 1 and 2 constituting the wavelength conversion sheet 10 of FIG. 1, the thickness of the first base material layers 12 and 22 arranged in the vicinity of the phosphor layer is preferably 8 μm or more and 50 μm or less, more preferably 8 μm or more and 25 μm. It is more preferably less than 8 μm or more, and further preferably 8 μm or more and 20 μm or less. The barrier properties of the first base material layers 12 and 22 can be improved by setting the thickness of the first base material layers 12 and 22 to 8 μm or more. When the thickness of the first base material layers 12 and 22 is 50 μm or less, oxygen and water vapor passing through the side surfaces of the first base material layers 12 and 22 can be reduced.

In the barrier film constituting the wavelength conversion sheet of FIG. 1, the thickness of the second base material layers 15 and 25 is preferably more than 25 μm and 200 μm or less, more preferably 50 μm or more and 150 μm or less. When the thickness of the second base material layers 15, 25 is more than 25 μm and 200 μm or less, the flexibility of the wavelength conversion sheet is improved, and the handleability is improved when the sheet is attached to the backlight source of the display device.

The base layer preferably has a high total light transmittance measured according to JIS K 7361 in order to avoid blocking light from the backlight source. Specifically, the first base material layers 12 and 22 and the second base material layer preferably have a total light transmittance of 85% or more, preferably 90% or more, as measured according to JIS K 7361. is more preferable.

If necessary, a desired surface treatment layer may be provided in advance on the surface of the substrate layer (not shown) in order to improve adhesion with a barrier layer, which will be described later. As the surface treatment layer, for example, corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, oxidation treatment using chemicals, etc., and other pretreatments are optional. For example, a corona-treated layer, an ozone-treated layer, a plasma-treated layer, an oxidation-treated layer, and the like can be formed and provided.

The above-mentioned surface pretreatment is carried out as a method for improving adhesion between a film or sheet of various resins and a barrier layer to be described later. In addition, for example, a primer coating agent layer, an undercoat agent layer, an anchor coating agent layer, an adhesive layer, or a vapor deposited anchor coating agent layer may be optionally formed in advance on the surface of various resin films or sheets. , can also be used as a surface treatment layer.

Examples of the coating agent layer include polyester-based resins, polyamide-based resins, polyurethane-based resins, epoxy-based resins, phenol-based resins, (meth)acrylic-based resins, polyvinyl acetate-based resins, and polyolefin-based resins such as polyethylene and polypropylene. Resin compositions containing resins, copolymers thereof, modified resins, cellulosic resins, etc. as the main component of the vehicle can be used.

(barrier layer)
The barrier layer is a layer that imparts barrier properties to the barrier film, and is generally formed by applying an organic coating layer containing a coating agent containing a water-soluble polymer such as polyvinyl alcohol and/or depositing an inorganic oxide. It is an inorganic oxide thin film layer formed by The barrier layer is a layer composed of a plurality of layers in which an organic coating layer and an inorganic oxide thin film layer are laminated. The barrier layer is not limited to a plurality of layers in which the organic coating layer and the inorganic oxide thin film layer are laminated, and each of the organic coating layer and the inorganic oxide thin film layer may be a single layer, Alternatively, it may be a layer in which two or more layers of an organic coating layer and an inorganic oxide thin film layer are alternately laminated. In addition, since the organic coating layer is laminated in close contact with the primer layer, it is possible to reduce the occurrence of scratches and cracks in the inorganic oxide thin film layer laminated inside the organic coating layer.

The organic coating layer is a layer that prevents various secondary damages in post-processes and imparts high barrier properties to the barrier film. The organic coating layer is formed by coating a gas barrier composition containing, for example, a water-soluble polymer and an aqueous solution or water/alcohol mixed solution containing at least one of one or more metal alkoxides and hydrolysates, or tin chloride as a coating liquid. Formed by coating. The organic coating layer preferably contains at least one component selected from the group consisting of hydroxyl-containing polymer compounds, metal alkoxides, metal alkoxide hydrolysates and metal alkoxide polymers. Examples of the water-soluble polymer used for the organic coating layer include polyvinyl alcohol, polyvinylpyrrolidone, and ethylene/vinyl alcohol copolymer. The coating layer has the most excellent gas barrier properties. The content of the polyvinyl alcohol-based resin and/or the ethylene/vinyl alcohol copolymer is in the range of 5 parts by mass or more and 500 parts by mass or less with respect to 100 parts by mass of the total amount of the above alkoxides, preferably It is preferable to prepare the gas barrier composition at a mixing ratio of about 20 parts by mass or more and 200 parts by mass or less.

A silane coupling agent or the like can also be added to the gas barrier composition. A known organic reactive group-containing organoalkoxysilane can be used as the silane coupling agent. In the present invention, organoalkoxysilanes having an epoxy group are particularly preferred, such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, or β-( 3,4-Epoxycyclohexyl)ethyltrimethoxysilane and the like can be used. The above silane coupling agents may be used singly or in combination of two or more. In the present invention, the amount of the silane coupling agent as described above can be used within a range of 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the alkoxysilane.

Although the film thickness of the organic coating layer is not particularly limited, it is preferably 100 nm or more and 500 nm or less. When the film thickness of the organic coating layer is 100 nm or more, sufficient barrier properties can be imparted to the barrier film. When the film thickness of the organic coating layer is 500 nm or less, the transparency is excellent and the properties of the wavelength conversion sheet are not deteriorated.

The inorganic oxide thin film layer is a layer that imparts high barrier properties to the barrier film, similar to the organic coating layer. The inorganic oxide thin film layer can be exemplified by a layer made of aluminum oxide, silicon oxide, magnesium oxide, or a mixture thereof. A thin film layer containing aluminum oxide or silicon oxide as a main component is preferable from the viewpoint of being able to impart sufficient barrier properties to the barrier film and from the viewpoint of productivity of the barrier film.

A method of forming the inorganic oxide thin film layer can include a method of forming by vapor deposition of an inorganic oxide. Examples of methods for forming a deposited film include physical vapor deposition methods (physical vapor deposition method, PVD method) such as vacuum deposition method, sputtering method, and ion plating method, plasma chemical vapor deposition method, thermochemical vapor deposition method, etc. A chemical vapor deposition method (Chemical Vapor Deposition method, CVD method) such as a chemical vapor deposition method and a photochemical vapor deposition method can be used.

Although the film thickness of the inorganic oxide thin film layer is not particularly limited, it is preferably 5 nm or more and 500 nm or less. When the thickness of the inorganic oxide thin film layer is 5 nm or more, the inorganic oxide thin film layer becomes uniform, and sufficient barrier properties can be imparted to the barrier film. When the thickness of the inorganic oxide thin film layer is 500 nm or less, the inorganic oxide thin film layer 1 can be sufficiently flexible, and scratches and cracks occur in the inorganic oxide thin film layer. Risk can be reduced.

The barrier layer preferably has a high total light transmittance measured according to JIS K 7361 in order to prevent the light from the backlight source from being blocked. Specifically, the barrier film preferably has a total light transmittance of 85% or more, more preferably 90% or more, as measured according to JIS K 7361. The total light transmittance is a value measured when a barrier layer is formed on a PET film (thickness: 12 μm).

(adhesive layer)
The barrier film 1 according to the present embodiment may have an adhesive layer 14 laminated between the barrier layer 13 and the second base material layer 15, as shown in FIG. Examples of adhesives constituting the adhesive layer 14 include polyvinyl acetate-based adhesives, homopolymers such as ethyl, butyl, and 2-ethylhexyl acrylates, or combinations thereof with methyl methacrylate, acrylonitrile, styrene, and the like. Polyacrylic ester adhesives, cyanoacrylate adhesives, etc., made of copolymers, etc. Ethylene copolymers, etc. made of copolymers of ethylene and monomers such as vinyl acetate, ethyl acrylate, acrylic acid, methacrylic acid Polymer adhesives, cellulose adhesives, polyester adhesives, polyamide adhesives, polyimide adhesives, amino resin adhesives composed of urea resin or melamine resin, phenol resin adhesives, epoxy adhesives, polyurethane adhesives, reactive (meth)acrylic adhesives, rubber adhesives made of chloroprene rubber, nitrile rubber, styrene-butadiene rubber, etc., silicone adhesives, alkali metal silicates, low melting point An inorganic adhesive made of glass or the like can be used.

The composition system of the adhesive constituting the adhesive layer may be any composition form such as aqueous type, solution type, emulsion type, dispersion type, etc., and its properties may be in the form of film/sheet, powder, or solid. Further, the bonding mechanism may be of any type such as a chemical reaction type, a solvent volatilization type, a heat fusion type, a heat pressure type, or the like.

The adhesive constituting the adhesive layer can be applied, for example, by roll coating, gravure coating, knife coating, dip coating, spray coating, other coating methods, printing methods, etc., and the coating amount is 0. .1 g/m ² or more and 10 g/m ² or less (dry state) is desirable.

Instead of the adhesive layer made of the above adhesive, for example, a resin layer made of thermosetting resin or thermoplastic resin containing a cross-linking agent or the like may be laminated. Furthermore, a method of bonding by extrusion lamination may be used in which a thermoplastic resin such as EVA, ionomer, polyvinyl butyral (PVB), or polyethylene-based resin is melted and the melted thermoplastic resin is extruded for lamination.

(Phosphor layer)
The phosphor layer 11 is a layer for adjusting the emission wavelength of light emitted from the backlight source. The phosphor layer 11 contains one or more phosphors composed of quantum dots.

The quantum dots that form the phosphor 112 are semiconductor particles of predetermined size that have a quantum confinement effect. Quantum dots emit energy corresponding to the energy bandgap of the quantum dots when they absorb light from an excitation source and reach an energetically excited state. By adjusting the size of the quantum dots or the composition of the material, the energy bandgap can be adjusted to obtain different levels of wavelength bands of energy. Among other things, quantum dots can emit strong fluorescence in a narrow wavelength band. Therefore, the display device can be illuminated with light of the three primary colors with excellent color purity, so that the display device can have excellent color reproducibility.

The phosphor has a core as a light-emitting portion covered with a protective layer (shell). For example, cadmium selenide (CdSe), cadmium telluride (CdTe), cadmium sulfide (CdS) can be used for the core. Zinc sulfide (ZnS) can be used for the protective layer.

The phosphor layer 11 can be formed by laminating sealing resin 111 containing phosphor 112 . For example, it can be formed by applying a mixture containing phosphor 112 and sealing resin 111 to the surface of the base material layer and curing the mixture. The sealing resin 111 includes polyester (meth)acrylate, urethane (meth)acrylate, polyester-urethane (meth)acrylate, polyether (meth)acrylate, polyol (meth)acrylate, melamine (meth)acrylate, and isocyanurate (meth)acrylate. Photopolymerization resin of acrylic resin such as acrylate, epoxy (meth)acrylate, (meth)acrylate resin, heat of phenol resin, urea resin, melamine resin, epoxy resin, unsaturated polyester resin, polyester resin, silicone resin, polyurethane resin, etc. Curable resins, or thermoplastic resins such as EVA, ionomer, polyvinyl butyral (PVB), and polyethylene-based resins containing a cross-linking agent and the like can be used. From the viewpoint of adhesion between the phosphor layer and the substrate layer, it is preferable to include at least one or more resins selected from the group consisting of acrylic resins, epoxy resins, urethane resins, and polyester resins. Moreover, these may be used individually, or one or more may be mixed and used. Moreover, you may form the adhesion layer for improving adhesiveness.

<<3. Display device>>
A display device including the above wavelength conversion sheet will be described with reference to FIG. In the display device of FIG. 3, light emitted from LEDs 5, which are backlight sources arranged at the edge of the light guide plate 6, enters the light guide plate 6, and the light is emitted to the wavelength conversion sheet 10 through the light guide plate 6. This is a so-called surface mount type display device. The antireflection sheet 7 is provided as required.

In a so-called surface mount type display device, the wavelength conversion sheet is arranged so as to be in contact with the light guide plate. Here, in the case of a conventional barrier film or wavelength conversion sheet for a wavelength conversion sheet, the barrier film and the light guide plate stick to each other, which is a factor in significantly deteriorating the display characteristics of the liquid crystal display device.

However, in the case of a display device in which a light guide plate is arranged on the surface of the sticking prevention layer of the wavelength conversion sheet, sticking between the barrier film and the light guide plate can be effectively prevented even in a surface-mounted display device. can be suppressed.

As the light guide plate, a conventionally known light guide plate can be used. It can also be shaped.

Another display device having the above wavelength conversion sheet will be described with reference to FIG. The display device shown in FIG. 4 is a so-called direct type display device in which LEDs are arranged on the back side and light emitted from the light source is applied to the wavelength conversion sheet through a diffusion plate.

In a so-called direct type display device, the wavelength conversion sheet 10 is arranged so as to be in contact with the diffusion plate 8 . For the same reason as described above, sticking between the barrier film and the diffusion plate can be effectively suppressed.

<< 4. Other Embodiments of Barrier Film>>
A barrier film and a wavelength conversion sheet according to another embodiment of the present invention will be described with reference to FIGS. 5 and 6. FIG.

The barrier films 3 and 4 laminated on the wavelength conversion sheet 30 shown in FIG. Thereby, the adhesion between the barrier film and the phosphor layer can be improved. The primer layer may be laminated between the barrier layer and the phosphor layer like the wavelength conversion sheet of the embodiment shown in FIG. may The primer layer will be described below.

(primer layer)
The primer layer can include, for example, a primer layer containing a polyurethane-based resin composition, and preferably further contains a silane coupling agent and a filler.

Specific examples of the polyurethane-based resin composition include, for example, polymers obtained by reacting polyfunctional isocyanates with hydroxyl group-containing compounds, specific examples of which include tolylene diisocyanate, diphenylmethane diisocyanate, Aromatic polyisocyanates such as polymethylene polyphenylene polyisocyanate, or polyfunctional isocyanates such as aliphatic polyisocyanates such as hexamethylene diisocyanate and xylylene diisocyanate, polyether polyols, polyester polyols, poly A one-component or two-component polyurethane resin obtained by reaction with a hydroxyl group-containing compound such as acrylate polyol can be used. In the present embodiment, by using the polyurethane-based resin as described above, the elongation degree of the primer layer is improved, for example, the suitability for post-processing such as lamination processing or bag-making processing is improved, and post-processing is performed. It prevents the occurrence of cracks and the like in the barrier layer over time.

The primer layer preferably contains 40% by mass or more, more preferably 70% by mass or more, of the polyurethane-based resin composition based on the total amount of the primer layer. When the amount is 40% by mass or more, the extensibility of the primer layer is further improved. Moreover, the possibility of cracks occurring in the primer layer can be further reduced.

As silane coupling agents, organofunctional silane monomers having binary reactivity can be used, such as γ-chloropropyltrimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, vinyl-tris(β -methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltri Methoxysilane, N-β (aminoethyl)-γ-aminopropyltrimethoxysilane, N-β (aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-ureidopropyltriethoxysilane, bis(β-hydroxyethyl) - One or more of γ-aminopropyltriethoxysilane, an aqueous solution of γ-aminopropylsilicone, and the like can be used.

A silane coupling agent has a functional group at one end of its molecule, usually a chloro, alkoxy, or acetoxy group, which is hydrolyzed to form a silanol group (SiOH), which is used as an organic coating layer or an inorganic oxide. A silane coupling agent is modified by a covalent bond or the like on the surface of the thin film layer and on the ink that can form the phosphor layer to form a strong bond.

On the other hand, an organic functional group such as vinyl, methacryloxy, amino, epoxy or mercapto at the other end of the silane coupling agent is formed on the thin film of the silane coupling agent.

The primer layer preferably contains 1% by mass or more and 30% by mass or less, more preferably 3% by mass or more and 20% by mass or less of the silane coupling agent based on the total amount of the primer layer. When it is 1% by mass or more, the adhesion between the barrier layer and the primer layer and the adhesion between the primer layer and the phosphor layer are further improved. When the content is 30% by mass or less, the extensibility of the primer layer is further improved. Moreover, the possibility of cracks occurring in the primer layer can be further reduced.

Examples of fillers that can be used include calcium carbonate, barium sulfate, alumina white, silica, talc, glass frit, resin powder, and the like. This adjusts the viscosity and the like of the primer agent to improve its coating suitability and the like.

The primer layer preferably contains 0.5% by mass or more and 30% by mass or less, more preferably 1% by mass or more and 10% by mass or less of the above-mentioned filler relative to the total amount of the primer layer. When it is 0.5% by mass or more, the coating aptitude for the substrate layer is improved, and blocking can be prevented. When it is 30% by mass or less, it is possible to suppress an increase in the haze value of the primer layer.

Additives such as a stabilizer, a curing agent, a cross-linking agent, a lubricant, an ultraviolet absorber, and others may optionally be added to the primer layer, if necessary.

The primer layer preferably has a high total light transmittance measured according to JIS K 7361 in order to avoid blocking light from the backlight source. Specifically, the primer layer according to the present embodiment preferably has a total light transmittance of 85% or more, more preferably 90% or more, as measured according to JIS K 7361. The total light transmittance is a value measured when a primer layer is formed on a PET film (thickness: 12 μm).

The film thickness of the primer layer is, for example, preferably 0.05 μm or more and 10 μm or less, more preferably 0.1 μm or more and 3 μm or less.

<<5. Barrier film manufacturing method>>
An example of a method for manufacturing the barrier film 1 shown in FIG. 2 will be described. The method for producing the barrier film 1 includes, for example, a barrier layer lamination step of laminating the barrier layer 13 on one surface of the first base material layer 12, and a second base layer lamination step of laminating the second base layer 15 via the adhesive layer 14; and a step of laminating an anti-sticking layer.

[Barrier layer lamination step]
In the barrier layer lamination step, an organic coating layer and/or an inorganic oxide thin film layer is laminated as a barrier layer on one surface of the base film. The organic coating layer can be formed by applying and curing a coating agent containing a water-soluble polymer such as polyvinyl alcohol. Methods for applying the coating agent include roll coating, gravure coating, knife coating, dip coating, spray coating, and other coating methods. An inorganic oxide thin film layer can be formed by vapor-depositing an inorganic oxide. The method of depositing the inorganic oxide is a physical vapor deposition method (physical vapor deposition method, PVD method) such as a vacuum deposition method, a sputtering method, and an ion plating method, or a plasma chemical vapor deposition method, a thermochemical vapor deposition method, or a chemical vapor deposition method. A chemical vapor deposition method (Chemical Vapor Deposition method, CVD method) such as a phase growth method and a photochemical vapor deposition method can be used.

Incidentally, on one surface of the substrate film, a primer coating agent layer, an undercoat agent layer, an anchor coating agent layer, a layer composed of an adhesive agent, or a deposited anchor coating agent layer or the like is optionally formed in advance, and the surface is treated. It can also be layered.

At this stage, as the barrier property at the stage of laminating the base film and the barrier layer, the value of oxygen permeability according to JIS K-7126 is 5 cc/m ² · day · atm or less (23 ° C., 90 % RH). Further, it is preferable that the value of water vapor transmission rate according to JIS K-7129 B method is 5 g/m ² ·day·atm or less (40°C, 90% RH). The oxygen permeability can be measured, for example, with an oxygen permeability measuring device OX-TRAN manufactured by MOCON (Mocon method). Further, the water vapor barrier property can be measured by, for example, a water vapor transmission rate measuring device PERMATRAN manufactured by MOCON.

[Second Base Material Layer Lamination Step]
In the second base material layer lamination step, the second base material layer is laminated on the surface of the barrier layer 13 with the adhesive layer 14 interposed therebetween. Specifically, an adhesive is applied to the surface of the barrier layer 13, and another base film is superimposed thereon. The adhesive can be applied by roll coating, gravure coating, knife coating, dip coating, spray coating, other coating methods, or printing methods.

[Sticking prevention layer lamination step]
In the sticking prevention layer lamination step, the sticking prevention layer 16 is laminated on the surface of the barrier film on the side of the second base material layer 15 . Specifically, a coating agent for laminating an anti-sticking layer containing a resin, a filler, a solvent, and the like can be applied to the surface of the barrier film on the second substrate layer 15 side and cured to form the coating. Methods for applying the coating agent include roll coating, gravure coating, knife coating, dip coating, spray coating, and other coating methods.

<<6. Method for producing barrier film in another embodiment>>
An example of a method for manufacturing the barrier film 3 shown in FIG. 6 will be described. The method of manufacturing the barrier film 3 includes, for example, a barrier layer lamination step of laminating the barrier layer 33 on one surface of the first base material layer 32, and a primer layer lamination step of laminating the primer layer 37 on the surface of the barrier layer. , an anti-sticking layer lamination step of laminating an anti-sticking layer 36 on one surface of the second base material layer 35, and the surface of the first base material layer 32 (the surface on the side where the barrier layer is not laminated) and a second base layer lamination step of laminating the second base layer 35 via the adhesive layer 34 to the second base layer lamination step.

Specifically, in the primer layer lamination step, a primer agent is applied to the surface of the barrier layer 33 . A solvent, a diluent, etc. are added to the above resin composition, etc., and a mixed primer agent is applied, for example, by roll coating, gravure coating, knife coating, dip coating, spray coating, or other coating methods to form an organic coating layer or an inorganic oxidation layer. and drying the coating film to remove solvents, diluents and the like. Thereby, a primer layer can be laminated.

<<7. Manufacturing method of wavelength conversion sheet>>
The wavelength conversion sheet is produced by, for example, the barrier film 1 shown in FIG. can be manufactured. Specifically, a mixture (ink) containing phosphor 110 and sealing resin 111 is applied to the surface of first base material layer 12 of barrier film 1 . And the wavelength conversion sheet 10 shown in FIG. 1 can be manufactured by contacting the surface of the 1st base material layer 22 of the barrier film 2, and hardening a liquid mixture (ink). A mixture (ink) containing the phosphor 112 and the sealing resin 111 may be applied to the surface of the first base material layer 22 of the barrier film 2 .

When manufacturing the wavelength conversion sheet shown in FIG. 5, a mixture (ink) containing phosphor 312 and sealing resin 311 is applied to the surfaces of primer layers 37 and 47 of barrier films 3 and 4. can be produced in the same way.

<<8. Display device manufacturing method>>
The display device can be manufactured through a process of arranging a light guide plate on the surface of the sticking prevention layer of the wavelength conversion sheet.

The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these descriptions.

<Manufacture of barrier film>
A barrier layer was laminated on the surface of the first substrate layer. Specifically, first, a base film (biaxially stretched polyethylene terephthalate film, 12 μm) is attached to the delivery roll of a take-up type vacuum vapor deposition apparatus, then it is fed out, and one surface of the base film is coated with An inorganic coating layer (barrier layer) of aluminum oxide having a film thickness of 10 nm was formed by a vacuum deposition method using an electron beam (EB) heating method while supplying oxygen gas using aluminum as a deposition source.

Next, on the other hand, composition a. A previously prepared composition b. A hydrolyzate composed of ethyl silicate, hydrochloric acid, isopropyl alcohol and ion-exchanged water was added and stirred to obtain a colorless and transparent gas barrier composition.

Next, a gas barrier composition is used on the above inorganic coating layer (barrier layer), coated by a gravure roll coating method, and then heat-treated at 100° C. for 10 seconds to obtain a thickness of An organic coating layer (barrier layer) of 300 nm (dry state) was formed.

Next, a primer layer was laminated on the barrier layer (organic coating layer). First, using γ-glycidoxypropyltrimethoxysilane as a silane coupling agent, 1.0% by weight of the silane coupling agent, 1.0% by weight of silica powder, 13 to 15% by weight of polyurethane resin, nitro A polyurethane resin composition containing 3 to 4% by weight of cellulose, 31 to 38% by weight of toluene, 29 to 30% by weight of methyl ethyl ketone (MEK), and 15 to 16% by weight of isopropyl alcohol (IPA) was obtained.

Then, the barrier layer of the film laminated with the barrier layer is coated with the polyurethane resin composition by a roll coating method, and then dried at 120° C. for 20 seconds to form a primer layer made of the polyurethane resin composition. 500 nm was laminated. The stacking order of this laminate is primer layer/organic coating layer (barrier layer)/inorganic oxide thin film layer (barrier layer)/substrate film (first substrate layer).

Next, an anti-sticking layer was laminated on one surface of another base film (biaxially oriented polyethylene terephthalate film, 50 μm). Specifically, spherical particles containing a polyacrylic resin as a filler (Eposter MA (a resin that is an acrylic crosslinked product and has a compressive strength of 2.8 kgf/mm ² or more), the average particle size of the filler is 4 μm) and the resin was mixed with an acrylic resin to prepare a coating agent for forming an anti-sticking layer (the solid content and filler content are shown in the table below). Then, the coating agent was applied to the surface of the substrate film by a gravure roll coating method (the coating amount after drying is shown in the table below).

Next, the surface of the base film (second base layer) side of the base film laminated with the anti-sticking layer is coated with a two-liquid curing type polyurethane laminating adhesive by a gravure roll coating method. to form an adhesive layer with a thickness of 4.0 g/m ² (dry state).

Next, the substrate film (first substrate layer) side of the laminate having the barrier layer laminated thereon is superposed on the surface of the adhesive layer, and dry lamination is performed to obtain an embodiment as shown in FIG. 1 to 7, and the barrier films of Comparative Examples 1 to 5 (the order of lamination is "primer layer/organic coating layer (barrier layer)/inorganic oxide thin film layer (barrier layer)/base film (first base layer) /adhesive layer/second base material layer/anti-sticking layer").

Barrier film of Comparative Example 6 without lamination of sticking prevention layer (Lamination order is "Primer layer / Organic coating layer (barrier layer) / Inorganic oxide thin film layer (barrier layer) / Base film (first base layer) )/adhesive layer/second substrate layer.) was manufactured.

In addition, the filler contained in the coating agent for forming the sticking prevention layer is an amorphous polyethylene filler (modified polyethylene wax CERAFLOUR 950 (manufactured by BYK-Chemie Japan) with a compressive strength of less than 2.8 kgf/mm ² . Then, the average particle diameter (D50) of the filler was changed to 9 μm), and the barrier film of Comparative Example 7 was prepared in the same manner as described above (the order of lamination is “primer layer/organic coating layer (barrier layer)/inorganic oxide thin film layer (barrier layer). layer)/base film (first base layer)/adhesive layer/second base layer/anti-sticking layer").

<Measurement of haze value>
The haze values of the anti-sticking layers of the barrier films of the above Examples and Comparative Examples were measured. Specifically, the haze (%) of the anti-sticking layer was measured with a haze meter (HM-150, manufactured by Murakami Color Co., Ltd.) in accordance with JIS K7136. Table 1 shows the results.

<Production of wavelength conversion sheet>
A wavelength conversion sheet was produced using the barrier films of the above Examples and Comparative Examples. Specifically, a phosphor (quantum dots with an average particle size of 3 to 5 nm) having a core made of cadmium selenide (CdSe) and a shell made of zinc sulfide (ZnS), a sealing resin (urethane acrylate resin, A mixed liquid (ink) was prepared by mixing 100 parts by mass of the sealing resin and 1 part by mass of the phosphor to form a phosphor layer.

A mixture (ink) for forming a phosphor layer was applied to the primer layer-side surface of the barrier films of Examples and Comparative Examples. Then, a barrier film in which an anti-sticking layer is not laminated in the above barrier film (the order of lamination is "primer layer / organic coating layer (barrier layer) / inorganic oxide thin film layer (barrier layer) / base film (second 1 base layer)/adhesive layer/second base layer") are superimposed so as to be in contact with the surface of the primer layer and the mixed liquid (ink), and the mixed liquid (ink) is dried. A wavelength conversion sheet was manufactured so that the thickness of the phosphor layer was 100 μm.

<Sticking test>
For the wavelength conversion sheet, a confirmation test of sticking to the light guide plate after the environmental test was performed. Specifically, a sticking prevention layer of a wavelength conversion sheet (50 mm×50 mm) and a light guide plate were laminated so that each wavelength conversion sheet was in contact with the light guide plate to produce a wavelength conversion sheet with a light guide plate. Further, a weight of 300 g was placed on the wavelength conversion sheet to apply weight. Then, the wavelength conversion sheet with light guide plate was left for 100 hours in an environmental test at a temperature of 60° C. and a humidity of 90% and a temperature of 80° C. After standing for 100 hours, the sticking of each wavelength conversion sheet with light guide plate was confirmed. The evaluation results are shown in Table 1 (denoted as "sticking" in the table).

(Evaluation criteria)
◯: No sticking was observed between the barrier film and the light guide plate, or a slight sticking was observed to the extent that there was no practical problem.
x: Sticking was mostly observed between the barrier film and the light guide plate.

<Hardness Confirmation Test>
The pencil hardness of the surface of the anti-stick layer of the barrier films of Examples and Comparative Examples was measured and confirmed by a test according to JISK5600-5-4 (1999). The evaluation results are shown in Table 1 (indicated as "pencil hardness" in Table 1).

<Vibration test>
A vibration test was performed to confirm the effect of preventing scratches caused by foreign matter on the sticking layer of the barrier films of Examples and Comparative Examples. Specifically, two barrier films of Example and Comparative Example (lower surface 200 mm × 200 mm, upper surface 200 × 100 mm) were prepared, and the adhesion layers (for the barrier film of Comparative Example 6, the second base layer ) were placed in a vibrating device (Gakushin type friction fastness tester AB-301 manufactured by Tester Sangyo Co., Ltd.). Ten glass beads with a diameter of 0.3 mm were placed between the two barrier films.

Then, weights (200 g×6 pieces) were placed on the barrier film via a resin film, vibrated at a vibration speed of 0.5 Hz for 10 minutes, and the occurrence of scratches was visually confirmed. The evaluation results are shown in Table 1 (indicated as "vibration test" in the table).

(Evaluation criteria)
◯: No scratches were observed on the layer (adhering layer, etc.) in contact with the glass beads.
x: Occurrence of scratches was confirmed on the layer (sticking layer, etc.) in contact with the glass beads.

The "solid content" in the table means mass % of the solid content (resin, filler) in the total amount of the solvent for forming the anti-sticking layer.

"Filler concentration" in the table means mass % of the filler in the total amount of the anti-sticking layer-forming solvent.

The "coating amount" in the table means the coating amount per unit area after drying of the anti-sticking layer (mass of solid content, unit: g/m ² ).

"Twice or more filler ratio" in the table means the ratio of filler having a particle size two or more times the thickness of the anti-sticking layer, calculated using a laser microscope (OLS4000 manufactured by Olympus). is the value Specifically, the surface of the anti-sticking layer having a predetermined area (for example, 258 × 260 μm) in plan view is observed with a laser microscope, an image is obtained, and the particles and the diameter of the particles are measured from the image, It is a value obtained by calculating the ratio of the filler having a particle size that is twice or more the thickness of the anti-sticking layer.

From the above evaluation results, the barrier film for the wavelength conversion sheet of the present invention is such that the light guide plate and the wavelength conversion sheet in the display device stick together even when the atmosphere of the environment in which the display device is arranged changes. It can be seen that the barrier film for the wavelength conversion sheet has excellent environmental stability.

Furthermore, the barrier films of Examples 1 to 7, in which the coating amount of the anti-sticking layer after drying is 1.0 g/m ² or more and 3.6 g/m ² or less and the haze value is 10% or more and 35% or less, , the pencil hardness was "HB" or higher, and the occurrence of scratches could not be confirmed even in the vibration test. From the results of this test, it can be seen that the barrier film can effectively suppress the occurrence of scratches on the anti-sticking layer.

1, 3 Barrier film (barrier film with anti-sticking layer)
2, 4 barrier film 11, 31 phosphor layer 111, 311 sealing resin 112, 312 phosphor 12, 22, 32, 42 substrate layer (first substrate layer)
13, 23, 33, 43 Barrier layer 13a, 23a, 33a, 43a Organic coating layer 13b, 23b, 33b, 43b Inorganic oxide thin film layer 14, 24, 34, 44 Adhesive layer 15, 25, 35, 45 Base material Layer (second substrate layer)
16, 36 sticking prevention layer 161, 361 resin 162, 362 filler 37, 47 primer layer 10, 30 wavelength conversion sheet 5 LED
6 light guide plate 7 antireflection sheet 8 diffusion plate

Claims (7)

A barrier film for a wavelength conversion sheet used as a backlight source for a display device and arranged on one surface of a phosphor layer containing a phosphor,
The barrier film is a multilayer film containing at least a barrier layer and a substrate layer,
On one surface of the barrier film,
A sticking prevention layer containing a resin and a filler is laminated,
The content of the filler is 10% by mass or more and 40% by mass or less with respect to the total amount of the anti-sticking layer,
The filler contains a resin having a compressive strength of 2.8 kgf/mm ² or more as measured in accordance with JIS A 9511,
The average particle size of the filler is 1 μm or more and 10 μm or less,
The coating amount of the anti-sticking layer after drying is 1.0 g/m ² or more and 3.6 g/m ² or less, and the haze value measured according to JIS K7136 is 10% or more and 35% or less Barrier the film. The barrier film according to claim 1, wherein the filler contained in the anti-sticking layer contains an acrylic resin. The barrier film according to claim 1 or 2, wherein the resin contained in the anti-sticking layer contains an acrylic resin. The barrier film according to any one of claims 1 to 3, wherein a primer layer is laminated on the surface of the barrier film on which the phosphor layer is laminated. One surface of the phosphor layer containing the phosphor faces the surface of the barrier film according to any one of claims 1 to 4 opposite to the surface on which the anti-sticking layer is laminated. Wavelength conversion sheet laminated like this. A surface-mounted display device comprising a light guide plate,
A display device, wherein the light guide plate is arranged on the surface of the sticking prevention layer of the wavelength conversion sheet according to claim 5 . A direct type display device comprising a diffusion plate,
A display device, wherein the diffusion plate is arranged on the surface of the sticking prevention layer of the wavelength conversion sheet according to claim 5 .

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